A new anion exchanger with pyridine groups was prepared by grafting of 2-vinyl pyridine onto polypropylene(PP) nonwoven fabrics by pre-irradiation grafting technique, followed by quaternization of pyridine rings in gr...A new anion exchanger with pyridine groups was prepared by grafting of 2-vinyl pyridine onto polypropylene(PP) nonwoven fabrics by pre-irradiation grafting technique, followed by quaternization of pyridine rings in grafted chains in reaction with bromoethane. The results showed that the grafting yield increased with the monomer concentration and conversion ratio of quaternization increased with the time. The grafted and quaternized fabrics were characterized by FT-IR, DSC, SEM and ICP. The possibility of adsorption of perrhenate(ReO–4), a nonradioactive analogue to pertechnetate(99TcO–4), from aqueous solution by anion exchanger was investigated. The experiments performed at pH= 0.1–6 showed that p H = 2.2 was the optimal acidity for ReO–4adsorption, and an adsorption equilibrium was achieved in 30 min. The reaction enthalpy was-12.55 k J/mol,indicating that the adsorption process is exothermic. XPS tests indicated that the Re O–4uptake was a typical ion exchange between Cl–on anion exchanger and ReO–4.展开更多
Budding is an important grafting technique to asexually propagate pecan(Carya illinoinensis(Wangenh.)K.Koch).To determine factors that might hamper success-ful budding of the species,a representative easy-to-survive c...Budding is an important grafting technique to asexually propagate pecan(Carya illinoinensis(Wangenh.)K.Koch).To determine factors that might hamper success-ful budding of the species,a representative easy-to-survive cultivar‘Pawnee’and a typical difficult-to-survive culti-var‘Jinhua’were used for comprehensive analysis.Mor-phological observation showed that cells surrounding the secretory cells or sieve tube had collapsed in‘Jinhua’but not in‘Pawnee’during grafting.‘Jinhua’might suffer more hypoxia stress than‘Pawnee’as‘Jinhua’had higher catalase,superoxide dismutase,polyphenol oxidase,pyruvate decar-boxylase(PDC),alcohol dehydrogenase(ADH)activities during grafting and contained greater levels of hydrogen per-oxide 12 days after grafting(DAG).Transcriptions of PDC and ADH were also up-regulated significantly in‘Jinhua’whereas they were not significantly affected in‘Pawnee’.Phenylalanine ammonia-lyase activities of‘Jinhua’were consistently lower than that of‘Pawnee’.Initial phenol con-tents were similar between the two cultivars.Graft-promot-ing substances,including soluble sugar,soluble protein,and gibberellin(GA)were incompletely recovered in‘Jinhua’12 DAG while fully restored in‘Pawnee’.Increased levels of trans-zeatin riboside in‘Jinhua’were much smaller than in‘Pawnee’3 DAG.The contents of indole-3-acetic acid were similar,and the dynamics of abscisic acid were the same between the two genotypes.Results suggest that hypoxia stress and shortages of sugar,protein,GA,and cytokinin during the healing process might be key factors limiting successful budding of pecan.The degree of scion-rootstock compatibility and the content of phenols might be excluded as constraints for successful budding.展开更多
This paper presents a superhydrophobic melamine(ME)sponge(ME-g-PLMA)prepared via high-energy radiation-induced in situ covalent grafting of long-alkyl-chain dodecyl methacrylate(LMA)onto an ME sponge for efficient oil...This paper presents a superhydrophobic melamine(ME)sponge(ME-g-PLMA)prepared via high-energy radiation-induced in situ covalent grafting of long-alkyl-chain dodecyl methacrylate(LMA)onto an ME sponge for efficient oil–water separation.The obtained ME-g-PLMA sponge had an excellent pore structure with superhydrophobic(water contact angle of 154°)and superoleophilic properties.It can absorb various types of oils up to 66–168 times its mass.The ME-g-PLMA sponge can continuously separate oil slicks in water by connecting a pump or separating oil underwater with a gravity-driven device.In addition,it maintained its highly hydrophobic properties even after long-term immersion in different corrosive solutions and repeated oil adsorption.The modified ME-g-PLMA sponge exhibited excellent separation properties and potential for oil spill cleanup.展开更多
In this study,to efficiently remove Pb(Ⅱ) from aqueous environments,a novel L-serine-modified polyethylene/polypropylene nonwoven fabric sorbent(NWF-serine)was fabricated through the radiation grafting of glycidyl me...In this study,to efficiently remove Pb(Ⅱ) from aqueous environments,a novel L-serine-modified polyethylene/polypropylene nonwoven fabric sorbent(NWF-serine)was fabricated through the radiation grafting of glycidyl methacrylate and subsequent L-serine modification.The effect of the absorbed dose was investigated in the range of 5–50 kGy.NWF-serine was characterized by Fourier transform infrared spectroscopy,thermogravimetric analysis,and scanning electron microscopy.Batch adsorption tests were conducted to investigate the influences of pH,adsorption time,temperature,initial concentration,and sorbent dosage on the Pb(Ⅱ) adsorption performance of NWF-serine.The results indicated that Pb(Ⅱ) adsorption onto NWF-serine was an endothermic process,following the pseudo-second-order kinetic model and Langmuir isotherm model.The saturated adsorption capacity was 198.1 mg/g.NWF-serine exhibited Pb(Ⅱ) removal rates of 99.8% for aqueous solutions with initial concentrations of 100 mg/L and 82.1% for landfill leachate containing competitive metal ions such as Cd,Cu,Ni,Mn,and Zn.Furthermore,NWF-serine maintained 86% of its Pb(Ⅱ) uptake after five use cycles.The coordination of the carboxyl and amino groups with Pb(Ⅱ) was confirmed using X-ray photoelectron spectroscopy and extended X-ray absorption fine structure analysis.展开更多
Binary monomers of maleic acid and vinyl acetate are grafted onto poly(vinylidene fluoride) (PVDF) powder by pre-irradiation induced graft polymerization technique in emulsion solution. The co-grafting of binary monom...Binary monomers of maleic acid and vinyl acetate are grafted onto poly(vinylidene fluoride) (PVDF) powder by pre-irradiation induced graft polymerization technique in emulsion solution. The co-grafting of binary monomers is successfully proved by FT-IR spectroscopy analysis. The influences of the absorbed dose, reaction temperature, reaction time, total concentration of monomers, and feed ratio of binary monomers on the degree of grafting are investigated. The thermal property of grafted PVDF powder was characterized by differential scanning calorimetry (DSC) and thermo-gravimetry analysis (TGA).展开更多
The effect of maleic anhydride grafted styrene-ethylene- buty-lene-styrene block copolymer （SEBS-g-MAH） and in-situ grafting MAH on mechanical, dynamic mechanical properties of wood flour/recycled plastic blends com...The effect of maleic anhydride grafted styrene-ethylene- buty-lene-styrene block copolymer （SEBS-g-MAH） and in-situ grafting MAH on mechanical, dynamic mechanical properties of wood flour/recycled plastic blends composites was investigated. Recycled plastic polypro-pylene （PP）, high-density polyethylene （HDPE） and polystyrene （PS）, were mixed with wood flour in a high speed blender and then extruded by a twin/single screw tandem extruder system to form wood flour/recycled plastic blends composites. Results show that the impact properties of the composites were improved more significantly by using SEBS-g-MAH compatibilizer than by using the mixtures of MAH and DCP via reactive blending in situ. However, contrary results were ob-served on the tensile and flexural properties of the corresponding com-posites. In General, the mechanical properties of composites made from recycled plastic blends were inferior to those made from virgin plastic blends, especially in elongation break. The morphological study verified that the interfacial adhesion or the compatibility of plastic blends with wood flour was improved by adding SEBS-g-MAH or in-situ grafting MAH. A better interfacial bonding between PP, HDPE, PS and wood flour was obtained by in-situ grafting MAH than the addition of SEBS-g-MAH. In-situ grafting MAH can be considered as a potential way of increasing the interfacial compatibility between plastic blends and wood flour. The storage modulus and damping factor of composites were also characterized through dynamic mechanical analysis （DMA）.展开更多
An amidoxime-based polymeric adsorbent was prepared by pre-irradiation grafting of acrylonitrile and acrylic acid onto high-density polyethylene fibers using electron beams,followed by amidoximation.Quantitative recov...An amidoxime-based polymeric adsorbent was prepared by pre-irradiation grafting of acrylonitrile and acrylic acid onto high-density polyethylene fibers using electron beams,followed by amidoximation.Quantitative recovery of uranium was investigated by flow-through experiment using simulated seawater and marine test in natural seawater.The maximum amount of uranium uptake was 2.51 mg/g-ads after 42 days of contact with simulated seawater and 0.13 mg/g-ads for 15 days of contact with natural seawater.A lower uranium uptake in marine test can be attributed to the short adsorption time and the contamination of marine microorganisms and iron.However,the high selectivity toward uranium against vanadium may be beneficial to harvest uranyl ion onto adsorbents and the economic feasibility for recovery of uranium from seawater.展开更多
In order to control the surface pore sizes of polyvinylidene fluoride membranes and their distribution, low temperature plasma-induced grafting modifications of PVDF were studied to prepare hydrophobe membranes. By ar...In order to control the surface pore sizes of polyvinylidene fluoride membranes and their distribution, low temperature plasma-induced grafting modifications of PVDF were studied to prepare hydrophobe membranes. By argon （Ar） treating and subsequent grafting reaction, a hydrophobe monomer, styrene, was introduced into the PVDF membrane. Fourier transform infrared attenuated total reflection （FTIR-ATR） was utilized to characterize the chemical and physical changes in the Ar plasma modified membrane. The surface modifications of PVDF membranes were investigated by using scanning electron microscopy （SEM）, atomic force microscopy （AFM） and differential scanning calorimeter （DSC）. The water permeability and the solute rejection were measured by PVDF membrane modified in different graft conditions. Results demonstrated that the pores in the modified membranes get smaller and the distribution of pores gets narrowed with the increase in grafting reaction duration. Longer graft time caused the water flux of PVDF membrane to decrease from 578 kg/（m^2· h） to 23 kg/（m^2· h） and the solute rejection to increase from 73% to 92%.展开更多
Grafting of polymer of methyl methacrylate （PMMA） onto titanium dioxide powder is investigated in this paper. The graft polymerization reaction is induced by dielectric-barrier- discharge produced N2 plasma treatmen...Grafting of polymer of methyl methacrylate （PMMA） onto titanium dioxide powder is investigated in this paper. The graft polymerization reaction is induced by dielectric-barrier- discharge produced N2 plasma treatment of titanium dioxide surfaces. IR, XPS and TGA results show that PMMA is grafted onto the surfaces of titanium dioxide powder. And crystal structure of the titanium dioxide powder observed with XRD spectra is unchanged after plasma graft polymerization.展开更多
Objective To systematically review randomized controlled trials to compare myocardial protection profiles of sevoflurane with propofol in patients undergoing coronary artery bypass grafting （CABG） surgery. Methods ...Objective To systematically review randomized controlled trials to compare myocardial protection profiles of sevoflurane with propofol in patients undergoing coronary artery bypass grafting （CABG） surgery. Methods Electronic databases were searched to identify all randomized controlled trials comparing sevoflurane with propofol for protecting myocardium in adult patients undergoing CABG surgery. Two authors independently extracted patients＇ perioperative data, including patients＇ baseline characteristics, surgical variables, and outcome data. For continuous variables, treatment effects were calculated as weighted mean difference （WMD） and 95% confidential interval （C/）. For dichotomous data, treatment effects were calculated as odds ratio （OR） and 95% CI. Each outcome was tested for heterogeneity, and randomized-effects or fixed-effects model was used in the presence or absence of significant heterogeneity （Q test P〈0.05）. Sensitivity analyses were done by examining the influence of statistical model on estimated treatment effects. Publication bias was explored through visual inspection of funnel plots of the outcomes. Statistical significance was defined as P〈0.05. Results Our search yielded 13 studies including 696 patients, and 402 patients were allocated into sevoflurane group and 294 into propofol group. There was no significant difference in postoperative mechanical ventilation time, inotropic support, mortality, myocardial infarction, and atrial fibrillation between the two groups （all P〉0.05）. Patients randomized into sevoflurane group had higher post-bypass cardiac index （WMD=0.39, 95% CI： 0.18 to 0.60, P=0.0003）, lower troponin I level （WMD=-0.82, 95% CI：-0.87 to -0.85, P=0.0002）, lower incidence of myocardial ischemia （OR=0.37, 95% CI： 0.16 to 0.83, P=0.02）, shorter ICU and hospital stay length （WMD=-10.99, 95% CI： -12.97 to -9.01, P〈0.00001; WMD=-0.78, 95% CI： -1.00 to -0.56, P〈0.00001, respectively）. Conclusion This meta-analysis has found some evidence showing that sevoflurane has better myocardial protection than propofol in CABG surgery.展开更多
We assessed different rootstocks and grafting techniques to clonally propagate mastic tree （Pistacia lentiscus var. chia）. Mastic tree is a dioecious tree but the quantity and quality of the resin secreted by female...We assessed different rootstocks and grafting techniques to clonally propagate mastic tree （Pistacia lentiscus var. chia）. Mastic tree is a dioecious tree but the quantity and quality of the resin secreted by female trees are very low; therefore, male trees that are clonally propagated are used to establish commercial plantations for mastic production. Conventional long branch cuttings for clonal production requires too much materials and has a very low rooting rate. Rooting with tissue culture and green cuttings has also failed outdoors. Grafting of mastic on other Pistacia species has not been tried so far; therefore, this study was aimed at developing grafting methods for the clonal propagation of mastic. P. atlantica and P. lentiscus rootstocks were grafted from 15 February to 15 October every 15 days using three grafting methods and a two-factor randomized block trial design. Early spring （15 February-15 March） proved to be the best time for grafting using either of the rootstocks. The highest grafting success was attained using the scions grafted on P. atlantica from 15 February to 15 March. The best bud-burst percentage was obtained using P. atlantica and P. lentiscus rootstocks.展开更多
Fabrication of reusable adsorbents with satisfactory adsorption capacity and using environmentfriendly preparation processes is required for the environment-related applications. In this study,acrylic acid（AA） was g...Fabrication of reusable adsorbents with satisfactory adsorption capacity and using environmentfriendly preparation processes is required for the environment-related applications. In this study,acrylic acid（AA） was grafted onto bentonite（BT） to generate an AA-graft-BT（AA-g-BT）composite using a plasma-induced grafting technique considered to be an environment-friendly method. The as-prepared composite was characterized by scanning electron microscopy, x-ray powder diffraction, thermal gravity analysis, Fourier transform infrared spectroscopy and Barrett–Emmett–Teller analysis, demonstrating the successful grafting of AA onto BT. In addition, the removal of uranium（VI）（U（VI）） from contaminated aqueous solutions was examined using the as-prepared composite. The influencing factors, including contact time,p H value, ionic strength, temperature, and initial concentration, for the removal of U（VI） were investigated by batch experiments. The experimental process fitted best with the pseudo-secondorder kinetic and the Langmuir models. Moreover, thermodynamic investigation revealed a spontaneous and endothermic process. Compared with previous adsorbents, AA-g-BT has potential practical applications in treating U（VI）-contaminated solutions.展开更多
Objective To evaluate the outcome of off-pump coronary artery bypass grafting （OPCABG） using a bilateral internal mammary artery （BIMA） Y configuration graft to achieve total arterial myocardial revascularization....Objective To evaluate the outcome of off-pump coronary artery bypass grafting （OPCABG） using a bilateral internal mammary artery （BIMA） Y configuration graft to achieve total arterial myocardial revascularization. Methods From October 2002 to December 2008, 208 patients （196 males and 12 females） underwent OPCABG using a BIMA Y configuration graft. The average age of the patients was 56.5 ± 11.3 years, with an age range of 33-78 years. A total of 167 （80.2%） cases had triple-vessel disease. Left main stem disease was found in 33 （15.9%） cases, and double-vessel disease was found in 8 （3.9%） cases. The semi-skeletonization technique was used to harvest the two internal mammary arteries （IMAs）, and then the free right internal mammary artery was connected end-to-side to the left internal mammary artery （LIMA） in situ to complete the Y configuration graft. Off-pump and sequential anastomosis methods were used to perform coronary artery bypass surgery in all patients. Graft patency was assessed intm-operatively with the HT311 transit time flowmeter. Results A total of 728 distal anastomoses were performed in 208 patients, with the average being 3.5± 1.3 per person. No one died or experienced recurrent angina within 30 days after the operation. Conclusions OPCABG using the BIMA Y graft was safe and effective to achieve total arterial revascularization. This method avoids surgical operation on the ascending aorta and other incisions.展开更多
Objective To analyze the short-term outcomes of redo coronary artery bypass grafting(CABG) using on-pump and off-pump CABG techniques. Methods From January 2003 to August 2013, non-randomized 80 patients were treated ...Objective To analyze the short-term outcomes of redo coronary artery bypass grafting(CABG) using on-pump and off-pump CABG techniques. Methods From January 2003 to August 2013, non-randomized 80 patients were treated with redo CABG in the Department of Cardiac Surgery, Peking University Third Hospital. Among these patients, 40 underwent on-pump CABG technique(redo-ONCAB group) and 40 underwent off-pump CABG technique(redo-OPCAB group). Furthermore, transmyocardial laser revascularization was performed in high-risk patients who were not suitable to conventional grafting. Clinical data of the two groups were recorded and analyzed including operation time, coronary grafts, incomplete revascularization, postoperative ventilation, perioperative stroke, and low output syndrome, etc. Results There were no significantly differences in age, gender distribution, incidences of hypertension, stroke, and other clinical characteristics between redo-OPCAB group and redo-ONCAB group(all P>0.05), except for incidences of renal dysfunction and pulmonary disease(all P<0.05). The number of grafting vessels in the redo-ONCAB and redo-OPCAB groups was 2.1 ± 0.74 and 1.4 ±0.52 respectively. There was significant difference between the two groups(P=0.0243). Compared with the redo-ONCAB group, there was shorter operation time(P=0.0045), postoperative ventilation(P=0.0211) and intensive care unit stay(P=0.0400), as well as fewer use of platelet(P=0.0338) and blood transfusion(P=0.0034) in the redo-OPCAB group. The incidence of incomplete revascularization(P=0.0253) and the use of transmyocardial laser revascularization(P=0.0052) were higher in the redo-OPCAB group than those in the redo-ONCAB group(all P<0.05). However, no significant differences were showed for the incidence of the use of intra aortic balloon pump and continuous renal replacement therapy, perioperative stroke, low output syndrome, and in-hospital mortality between the two groups(all P>0.05). Conclusion Redo CABG is the safety and efficacy surgical procedure, and redo-OPCAB technique with better outcomes is commended especially in high-risk patients.展开更多
Background It is still controversial whether percutaneous coronary intervention with drug-eluting stent （DES） is safe and effective compared to coronary artery bypass graft surgery （CABG） for unprotected left main...Background It is still controversial whether percutaneous coronary intervention with drug-eluting stent （DES） is safe and effective compared to coronary artery bypass graft surgery （CABG） for unprotected left main coronary artery （ULMCA） disease at long-term follow up （≥3 years）. Methods Eligible studies were selected by searching PubMed, EMBASE, and Cochrane Library up to December 6, 2016. The primary endpoint was a composite of death, myocardial infarction （MI） or stroke during the longest follow-up. Death, cardiac death, MI, stroke and repeat revascularization were the secondary outcomes. Results Four randomized controlled trials and twelve adjusted observational studies involving 14,130 patients were included. DES was comparable to CABG regarding the occurrence of the primary endpoint （FIR = 0.94, 95% CI： 0.86-1.03）. Besides, DES was significantly associated with higher incidence of MI （HR = 1.56, 95% CI： 1.09-2.22） and repeat revascularization （HR = 3.09, 95% CI： 2.33-4.10） compared with CABG, while no difference was found between the two strategies regard as the rate of death, cardiac death and stroke. Furthermore, DES can reduce the risk of the composite endpoint of death, MI or stroke （HR = 0.80, 95% CI： 0.67-0.95） for ULMCA lesions with SYNTAX score ≤32. Conclusions Although with higher risk of repeat revascularization, PCI with DES appears to be as safe as CABG for ULMCA disease at long-term follow up. In addition, treatment with DES could be an alternative interventional strategy to CABG for ULMCA lesions with low to intermediate anatomic complexity.展开更多
The acidic effect in grafting of acrylonitrile onto wool fibre under mutual irradiation has been studied. The reactivity of various acids towards graft copolymerization was found as the order: H<sub>2</sub>...The acidic effect in grafting of acrylonitrile onto wool fibre under mutual irradiation has been studied. The reactivity of various acids towards graft copolymerization was found as the order: H<sub>2</sub>SO<sub>4</sub>】HNO<sub>3</sub>】HCl】HClO<sub>4</sub>】HOAC.展开更多
Poly(vinyl acetate)(PVAc) was grafted onto wheat straw by γ-irradiation to improve the compatibility between wheat straw and high-density polyethelene(PE).The grafting was proved by Fourier transform infrared(FTIR) s...Poly(vinyl acetate)(PVAc) was grafted onto wheat straw by γ-irradiation to improve the compatibility between wheat straw and high-density polyethelene(PE).The grafting was proved by Fourier transform infrared(FTIR) spectroscopy. The compact structure of wheat straw was loosened because the chemical bonds and crystalline structure were destructed by the γ-rays. The modified wheat straw needed less energy for thermal transition, as revealed by differential scanning calorimetry(DSC).Thermal analysis revealed that grafted PVAc acted as a protective barrier for the wheat straw and leads to an increase in maximum pyrolysis temperature. The crystallite size of grafted wheat straw decreased to 5.33 nm from 5.63 nm before irradiation. There were holes in melted form appeared on the surface of the grafted wheat straws.Both the grafted PVAc and irradiation are beneficial to lower the torque of wheat straw/PE melts and improve its mechanical properties by 36%. Possible mechanism of irradiation grafting was proposed.展开更多
An investigation of grafting of polymer of styrene （PSt） onto titanium dioxide powder is reported in this paper. The graft polymerization reaction was induced by N2 plasma treatment on the surface of titanium dioxid...An investigation of grafting of polymer of styrene （PSt） onto titanium dioxide powder is reported in this paper. The graft polymerization reaction was induced by N2 plasma treatment on the surface of titanium dioxide. Infrared （IR） spectra and X-ray photospectrum （XPS） results showed that PSt was grafted onto the titanium dioxide powder. An observation by X-ray diffraction （XRD） spectra indicated that the crystal structure of the titanium dioxide powder was unchanged after the plasma treatment.展开更多
Dielectric barrier discharge plasma in air was used to modify glass surface to induce the graft of silane onto the treated surface to increase the possibility of biomolecule immobilization. The plasma treated glass ha...Dielectric barrier discharge plasma in air was used to modify glass surface to induce the graft of silane onto the treated surface to increase the possibility of biomolecule immobilization. The plasma treated glass had been characterized by scanning electron microscopy （SEM）, Fourier transform infrared attenuated total reflection spectroscopy, X-ray photoelectron spectroscopy （XPS） and surface water contact angle measurement. The validity of grafting silane onto glass surface was approved by the analysis of water contact angle measurement, SEM and XPS. The grafted silane content was measured by visible absorption spectroscopy using acid Orange-7. It is shown that the grafting density of silane for glass samples increases significantly after plasma treatment.展开更多
基金Supported by the National Natural Science Foundation of China(No.91226111 and 11305102)Shanghai Science and Technology Foundation(No.12DZ2293800)
文摘A new anion exchanger with pyridine groups was prepared by grafting of 2-vinyl pyridine onto polypropylene(PP) nonwoven fabrics by pre-irradiation grafting technique, followed by quaternization of pyridine rings in grafted chains in reaction with bromoethane. The results showed that the grafting yield increased with the monomer concentration and conversion ratio of quaternization increased with the time. The grafted and quaternized fabrics were characterized by FT-IR, DSC, SEM and ICP. The possibility of adsorption of perrhenate(ReO–4), a nonradioactive analogue to pertechnetate(99TcO–4), from aqueous solution by anion exchanger was investigated. The experiments performed at pH= 0.1–6 showed that p H = 2.2 was the optimal acidity for ReO–4adsorption, and an adsorption equilibrium was achieved in 30 min. The reaction enthalpy was-12.55 k J/mol,indicating that the adsorption process is exothermic. XPS tests indicated that the Re O–4uptake was a typical ion exchange between Cl–on anion exchanger and ReO–4.
基金funded by the National Natural Science Foundation of China(3190134732001350)+1 种基金the Central Government Demonstration Project of Forestry Science and Technology(su[2022]TG11)the Key Research and Development Plan of Jiangxi Province(20223BBF61014).
文摘Budding is an important grafting technique to asexually propagate pecan(Carya illinoinensis(Wangenh.)K.Koch).To determine factors that might hamper success-ful budding of the species,a representative easy-to-survive cultivar‘Pawnee’and a typical difficult-to-survive culti-var‘Jinhua’were used for comprehensive analysis.Mor-phological observation showed that cells surrounding the secretory cells or sieve tube had collapsed in‘Jinhua’but not in‘Pawnee’during grafting.‘Jinhua’might suffer more hypoxia stress than‘Pawnee’as‘Jinhua’had higher catalase,superoxide dismutase,polyphenol oxidase,pyruvate decar-boxylase(PDC),alcohol dehydrogenase(ADH)activities during grafting and contained greater levels of hydrogen per-oxide 12 days after grafting(DAG).Transcriptions of PDC and ADH were also up-regulated significantly in‘Jinhua’whereas they were not significantly affected in‘Pawnee’.Phenylalanine ammonia-lyase activities of‘Jinhua’were consistently lower than that of‘Pawnee’.Initial phenol con-tents were similar between the two cultivars.Graft-promot-ing substances,including soluble sugar,soluble protein,and gibberellin(GA)were incompletely recovered in‘Jinhua’12 DAG while fully restored in‘Pawnee’.Increased levels of trans-zeatin riboside in‘Jinhua’were much smaller than in‘Pawnee’3 DAG.The contents of indole-3-acetic acid were similar,and the dynamics of abscisic acid were the same between the two genotypes.Results suggest that hypoxia stress and shortages of sugar,protein,GA,and cytokinin during the healing process might be key factors limiting successful budding of pecan.The degree of scion-rootstock compatibility and the content of phenols might be excluded as constraints for successful budding.
文摘This paper presents a superhydrophobic melamine(ME)sponge(ME-g-PLMA)prepared via high-energy radiation-induced in situ covalent grafting of long-alkyl-chain dodecyl methacrylate(LMA)onto an ME sponge for efficient oil–water separation.The obtained ME-g-PLMA sponge had an excellent pore structure with superhydrophobic(water contact angle of 154°)and superoleophilic properties.It can absorb various types of oils up to 66–168 times its mass.The ME-g-PLMA sponge can continuously separate oil slicks in water by connecting a pump or separating oil underwater with a gravity-driven device.In addition,it maintained its highly hydrophobic properties even after long-term immersion in different corrosive solutions and repeated oil adsorption.The modified ME-g-PLMA sponge exhibited excellent separation properties and potential for oil spill cleanup.
基金supported by the National Natural Science Foundation of China(Nos.11605275 and 11675247)。
文摘In this study,to efficiently remove Pb(Ⅱ) from aqueous environments,a novel L-serine-modified polyethylene/polypropylene nonwoven fabric sorbent(NWF-serine)was fabricated through the radiation grafting of glycidyl methacrylate and subsequent L-serine modification.The effect of the absorbed dose was investigated in the range of 5–50 kGy.NWF-serine was characterized by Fourier transform infrared spectroscopy,thermogravimetric analysis,and scanning electron microscopy.Batch adsorption tests were conducted to investigate the influences of pH,adsorption time,temperature,initial concentration,and sorbent dosage on the Pb(Ⅱ) adsorption performance of NWF-serine.The results indicated that Pb(Ⅱ) adsorption onto NWF-serine was an endothermic process,following the pseudo-second-order kinetic model and Langmuir isotherm model.The saturated adsorption capacity was 198.1 mg/g.NWF-serine exhibited Pb(Ⅱ) removal rates of 99.8% for aqueous solutions with initial concentrations of 100 mg/L and 82.1% for landfill leachate containing competitive metal ions such as Cd,Cu,Ni,Mn,and Zn.Furthermore,NWF-serine maintained 86% of its Pb(Ⅱ) uptake after five use cycles.The coordination of the carboxyl and amino groups with Pb(Ⅱ) was confirmed using X-ray photoelectron spectroscopy and extended X-ray absorption fine structure analysis.
基金Supported by National Natural Science Foundation of China (11175234, 11105210)Knowledge Innovation Program of Chinese Academy of Sciences (KJCX2-YW-N49, XDA02040300)Shanghai Municipal Commission for Science and Technology (10ZR1436700, 11ZR1445400)
文摘Binary monomers of maleic acid and vinyl acetate are grafted onto poly(vinylidene fluoride) (PVDF) powder by pre-irradiation induced graft polymerization technique in emulsion solution. The co-grafting of binary monomers is successfully proved by FT-IR spectroscopy analysis. The influences of the absorbed dose, reaction temperature, reaction time, total concentration of monomers, and feed ratio of binary monomers on the degree of grafting are investigated. The thermal property of grafted PVDF powder was characterized by differential scanning calorimetry (DSC) and thermo-gravimetry analysis (TGA).
基金supported by the National High Technology Research and Development Program of China(2010AA101703)the Natural Science Foundation of Heilongjiang Province of China (C200950)the Fundamental Research Fundsfor the Central Universities (DL09BB38)
文摘The effect of maleic anhydride grafted styrene-ethylene- buty-lene-styrene block copolymer （SEBS-g-MAH） and in-situ grafting MAH on mechanical, dynamic mechanical properties of wood flour/recycled plastic blends composites was investigated. Recycled plastic polypro-pylene （PP）, high-density polyethylene （HDPE） and polystyrene （PS）, were mixed with wood flour in a high speed blender and then extruded by a twin/single screw tandem extruder system to form wood flour/recycled plastic blends composites. Results show that the impact properties of the composites were improved more significantly by using SEBS-g-MAH compatibilizer than by using the mixtures of MAH and DCP via reactive blending in situ. However, contrary results were ob-served on the tensile and flexural properties of the corresponding com-posites. In General, the mechanical properties of composites made from recycled plastic blends were inferior to those made from virgin plastic blends, especially in elongation break. The morphological study verified that the interfacial adhesion or the compatibility of plastic blends with wood flour was improved by adding SEBS-g-MAH or in-situ grafting MAH. A better interfacial bonding between PP, HDPE, PS and wood flour was obtained by in-situ grafting MAH than the addition of SEBS-g-MAH. In-situ grafting MAH can be considered as a potential way of increasing the interfacial compatibility between plastic blends and wood flour. The storage modulus and damping factor of composites were also characterized through dynamic mechanical analysis （DMA）.
基金supported by the National Natural Science Foundation of China(Nos.21676291,21306220,11275252,11305243 and11405249)in part supported by the "Knowledge Innovation Program of Chinese academy of sciences"
文摘An amidoxime-based polymeric adsorbent was prepared by pre-irradiation grafting of acrylonitrile and acrylic acid onto high-density polyethylene fibers using electron beams,followed by amidoximation.Quantitative recovery of uranium was investigated by flow-through experiment using simulated seawater and marine test in natural seawater.The maximum amount of uranium uptake was 2.51 mg/g-ads after 42 days of contact with simulated seawater and 0.13 mg/g-ads for 15 days of contact with natural seawater.A lower uranium uptake in marine test can be attributed to the short adsorption time and the contamination of marine microorganisms and iron.However,the high selectivity toward uranium against vanadium may be beneficial to harvest uranyl ion onto adsorbents and the economic feasibility for recovery of uranium from seawater.
基金supported by the Major State Basic Research Program of China （No. 2009CB623404） National Natural Science Foundation of China （Nos. 20736003, 20676067）+2 种基金 National High Technology Research and Development Program of China （No. 2007AA06Z317）Foundation of Ministry of Education of China （No. 20070003130)Foundation of the State Key Laboratory of Chemical Engineering （No. SKL-ChE-08A01）
文摘In order to control the surface pore sizes of polyvinylidene fluoride membranes and their distribution, low temperature plasma-induced grafting modifications of PVDF were studied to prepare hydrophobe membranes. By argon （Ar） treating and subsequent grafting reaction, a hydrophobe monomer, styrene, was introduced into the PVDF membrane. Fourier transform infrared attenuated total reflection （FTIR-ATR） was utilized to characterize the chemical and physical changes in the Ar plasma modified membrane. The surface modifications of PVDF membranes were investigated by using scanning electron microscopy （SEM）, atomic force microscopy （AFM） and differential scanning calorimeter （DSC）. The water permeability and the solute rejection were measured by PVDF membrane modified in different graft conditions. Results demonstrated that the pores in the modified membranes get smaller and the distribution of pores gets narrowed with the increase in grafting reaction duration. Longer graft time caused the water flux of PVDF membrane to decrease from 578 kg/（m^2· h） to 23 kg/（m^2· h） and the solute rejection to increase from 73% to 92%.
文摘Grafting of polymer of methyl methacrylate （PMMA） onto titanium dioxide powder is investigated in this paper. The graft polymerization reaction is induced by dielectric-barrier- discharge produced N2 plasma treatment of titanium dioxide surfaces. IR, XPS and TGA results show that PMMA is grafted onto the surfaces of titanium dioxide powder. And crystal structure of the titanium dioxide powder observed with XRD spectra is unchanged after plasma graft polymerization.
文摘Objective To systematically review randomized controlled trials to compare myocardial protection profiles of sevoflurane with propofol in patients undergoing coronary artery bypass grafting （CABG） surgery. Methods Electronic databases were searched to identify all randomized controlled trials comparing sevoflurane with propofol for protecting myocardium in adult patients undergoing CABG surgery. Two authors independently extracted patients＇ perioperative data, including patients＇ baseline characteristics, surgical variables, and outcome data. For continuous variables, treatment effects were calculated as weighted mean difference （WMD） and 95% confidential interval （C/）. For dichotomous data, treatment effects were calculated as odds ratio （OR） and 95% CI. Each outcome was tested for heterogeneity, and randomized-effects or fixed-effects model was used in the presence or absence of significant heterogeneity （Q test P〈0.05）. Sensitivity analyses were done by examining the influence of statistical model on estimated treatment effects. Publication bias was explored through visual inspection of funnel plots of the outcomes. Statistical significance was defined as P〈0.05. Results Our search yielded 13 studies including 696 patients, and 402 patients were allocated into sevoflurane group and 294 into propofol group. There was no significant difference in postoperative mechanical ventilation time, inotropic support, mortality, myocardial infarction, and atrial fibrillation between the two groups （all P〉0.05）. Patients randomized into sevoflurane group had higher post-bypass cardiac index （WMD=0.39, 95% CI： 0.18 to 0.60, P=0.0003）, lower troponin I level （WMD=-0.82, 95% CI：-0.87 to -0.85, P=0.0002）, lower incidence of myocardial ischemia （OR=0.37, 95% CI： 0.16 to 0.83, P=0.02）, shorter ICU and hospital stay length （WMD=-10.99, 95% CI： -12.97 to -9.01, P〈0.00001; WMD=-0.78, 95% CI： -1.00 to -0.56, P〈0.00001, respectively）. Conclusion This meta-analysis has found some evidence showing that sevoflurane has better myocardial protection than propofol in CABG surgery.
基金financially supported by the Aegean Forestry Research Institute(No.15.2110/2008-2010)zmir Regional Directorate of Forestry
文摘We assessed different rootstocks and grafting techniques to clonally propagate mastic tree （Pistacia lentiscus var. chia）. Mastic tree is a dioecious tree but the quantity and quality of the resin secreted by female trees are very low; therefore, male trees that are clonally propagated are used to establish commercial plantations for mastic production. Conventional long branch cuttings for clonal production requires too much materials and has a very low rooting rate. Rooting with tissue culture and green cuttings has also failed outdoors. Grafting of mastic on other Pistacia species has not been tried so far; therefore, this study was aimed at developing grafting methods for the clonal propagation of mastic. P. atlantica and P. lentiscus rootstocks were grafted from 15 February to 15 October every 15 days using three grafting methods and a two-factor randomized block trial design. Early spring （15 February-15 March） proved to be the best time for grafting using either of the rootstocks. The highest grafting success was attained using the scions grafted on P. atlantica from 15 February to 15 March. The best bud-burst percentage was obtained using P. atlantica and P. lentiscus rootstocks.
基金the Special Scientific Fund of Public Welfare Profession of China (No. 201509074)National Natural Science Foundation of China (Nos. 21272236, U1230202)
文摘Fabrication of reusable adsorbents with satisfactory adsorption capacity and using environmentfriendly preparation processes is required for the environment-related applications. In this study,acrylic acid（AA） was grafted onto bentonite（BT） to generate an AA-graft-BT（AA-g-BT）composite using a plasma-induced grafting technique considered to be an environment-friendly method. The as-prepared composite was characterized by scanning electron microscopy, x-ray powder diffraction, thermal gravity analysis, Fourier transform infrared spectroscopy and Barrett–Emmett–Teller analysis, demonstrating the successful grafting of AA onto BT. In addition, the removal of uranium（VI）（U（VI）） from contaminated aqueous solutions was examined using the as-prepared composite. The influencing factors, including contact time,p H value, ionic strength, temperature, and initial concentration, for the removal of U（VI） were investigated by batch experiments. The experimental process fitted best with the pseudo-secondorder kinetic and the Langmuir models. Moreover, thermodynamic investigation revealed a spontaneous and endothermic process. Compared with previous adsorbents, AA-g-BT has potential practical applications in treating U（VI）-contaminated solutions.
文摘Objective To evaluate the outcome of off-pump coronary artery bypass grafting （OPCABG） using a bilateral internal mammary artery （BIMA） Y configuration graft to achieve total arterial myocardial revascularization. Methods From October 2002 to December 2008, 208 patients （196 males and 12 females） underwent OPCABG using a BIMA Y configuration graft. The average age of the patients was 56.5 ± 11.3 years, with an age range of 33-78 years. A total of 167 （80.2%） cases had triple-vessel disease. Left main stem disease was found in 33 （15.9%） cases, and double-vessel disease was found in 8 （3.9%） cases. The semi-skeletonization technique was used to harvest the two internal mammary arteries （IMAs）, and then the free right internal mammary artery was connected end-to-side to the left internal mammary artery （LIMA） in situ to complete the Y configuration graft. Off-pump and sequential anastomosis methods were used to perform coronary artery bypass surgery in all patients. Graft patency was assessed intm-operatively with the HT311 transit time flowmeter. Results A total of 728 distal anastomoses were performed in 208 patients, with the average being 3.5± 1.3 per person. No one died or experienced recurrent angina within 30 days after the operation. Conclusions OPCABG using the BIMA Y graft was safe and effective to achieve total arterial revascularization. This method avoids surgical operation on the ascending aorta and other incisions.
文摘Objective To analyze the short-term outcomes of redo coronary artery bypass grafting(CABG) using on-pump and off-pump CABG techniques. Methods From January 2003 to August 2013, non-randomized 80 patients were treated with redo CABG in the Department of Cardiac Surgery, Peking University Third Hospital. Among these patients, 40 underwent on-pump CABG technique(redo-ONCAB group) and 40 underwent off-pump CABG technique(redo-OPCAB group). Furthermore, transmyocardial laser revascularization was performed in high-risk patients who were not suitable to conventional grafting. Clinical data of the two groups were recorded and analyzed including operation time, coronary grafts, incomplete revascularization, postoperative ventilation, perioperative stroke, and low output syndrome, etc. Results There were no significantly differences in age, gender distribution, incidences of hypertension, stroke, and other clinical characteristics between redo-OPCAB group and redo-ONCAB group(all P>0.05), except for incidences of renal dysfunction and pulmonary disease(all P<0.05). The number of grafting vessels in the redo-ONCAB and redo-OPCAB groups was 2.1 ± 0.74 and 1.4 ±0.52 respectively. There was significant difference between the two groups(P=0.0243). Compared with the redo-ONCAB group, there was shorter operation time(P=0.0045), postoperative ventilation(P=0.0211) and intensive care unit stay(P=0.0400), as well as fewer use of platelet(P=0.0338) and blood transfusion(P=0.0034) in the redo-OPCAB group. The incidence of incomplete revascularization(P=0.0253) and the use of transmyocardial laser revascularization(P=0.0052) were higher in the redo-OPCAB group than those in the redo-ONCAB group(all P<0.05). However, no significant differences were showed for the incidence of the use of intra aortic balloon pump and continuous renal replacement therapy, perioperative stroke, low output syndrome, and in-hospital mortality between the two groups(all P>0.05). Conclusion Redo CABG is the safety and efficacy surgical procedure, and redo-OPCAB technique with better outcomes is commended especially in high-risk patients.
文摘Background It is still controversial whether percutaneous coronary intervention with drug-eluting stent （DES） is safe and effective compared to coronary artery bypass graft surgery （CABG） for unprotected left main coronary artery （ULMCA） disease at long-term follow up （≥3 years）. Methods Eligible studies were selected by searching PubMed, EMBASE, and Cochrane Library up to December 6, 2016. The primary endpoint was a composite of death, myocardial infarction （MI） or stroke during the longest follow-up. Death, cardiac death, MI, stroke and repeat revascularization were the secondary outcomes. Results Four randomized controlled trials and twelve adjusted observational studies involving 14,130 patients were included. DES was comparable to CABG regarding the occurrence of the primary endpoint （FIR = 0.94, 95% CI： 0.86-1.03）. Besides, DES was significantly associated with higher incidence of MI （HR = 1.56, 95% CI： 1.09-2.22） and repeat revascularization （HR = 3.09, 95% CI： 2.33-4.10） compared with CABG, while no difference was found between the two strategies regard as the rate of death, cardiac death and stroke. Furthermore, DES can reduce the risk of the composite endpoint of death, MI or stroke （HR = 0.80, 95% CI： 0.67-0.95） for ULMCA lesions with SYNTAX score ≤32. Conclusions Although with higher risk of repeat revascularization, PCI with DES appears to be as safe as CABG for ULMCA disease at long-term follow up. In addition, treatment with DES could be an alternative interventional strategy to CABG for ULMCA lesions with low to intermediate anatomic complexity.
基金The Project Supported by National Natural Science Foundation of China
文摘The acidic effect in grafting of acrylonitrile onto wool fibre under mutual irradiation has been studied. The reactivity of various acids towards graft copolymerization was found as the order: H<sub>2</sub>SO<sub>4</sub>】HNO<sub>3</sub>】HCl】HClO<sub>4</sub>】HOAC.
基金supported by the National Natural Science Foundation of China(No.11605077)the Free Exploration Project for Youth Research of Jiangsu Academy of Agricultural Sciences(No.ZX(15)4012)
文摘Poly(vinyl acetate)(PVAc) was grafted onto wheat straw by γ-irradiation to improve the compatibility between wheat straw and high-density polyethelene(PE).The grafting was proved by Fourier transform infrared(FTIR) spectroscopy. The compact structure of wheat straw was loosened because the chemical bonds and crystalline structure were destructed by the γ-rays. The modified wheat straw needed less energy for thermal transition, as revealed by differential scanning calorimetry(DSC).Thermal analysis revealed that grafted PVAc acted as a protective barrier for the wheat straw and leads to an increase in maximum pyrolysis temperature. The crystallite size of grafted wheat straw decreased to 5.33 nm from 5.63 nm before irradiation. There were holes in melted form appeared on the surface of the grafted wheat straws.Both the grafted PVAc and irradiation are beneficial to lower the torque of wheat straw/PE melts and improve its mechanical properties by 36%. Possible mechanism of irradiation grafting was proposed.
文摘An investigation of grafting of polymer of styrene （PSt） onto titanium dioxide powder is reported in this paper. The graft polymerization reaction was induced by N2 plasma treatment on the surface of titanium dioxide. Infrared （IR） spectra and X-ray photospectrum （XPS） results showed that PSt was grafted onto the titanium dioxide powder. An observation by X-ray diffraction （XRD） spectra indicated that the crystal structure of the titanium dioxide powder was unchanged after the plasma treatment.
基金National Natural Science Foundation of China(No.50537020)
文摘Dielectric barrier discharge plasma in air was used to modify glass surface to induce the graft of silane onto the treated surface to increase the possibility of biomolecule immobilization. The plasma treated glass had been characterized by scanning electron microscopy （SEM）, Fourier transform infrared attenuated total reflection spectroscopy, X-ray photoelectron spectroscopy （XPS） and surface water contact angle measurement. The validity of grafting silane onto glass surface was approved by the analysis of water contact angle measurement, SEM and XPS. The grafted silane content was measured by visible absorption spectroscopy using acid Orange-7. It is shown that the grafting density of silane for glass samples increases significantly after plasma treatment.
