Objective:Postpartum weight retention(PPWR)is a common problem among women after childbirth.The main objectives of this study are to understand the changes in body weight of breastfeeding mothers during long-term foll...Objective:Postpartum weight retention(PPWR)is a common problem among women after childbirth.The main objectives of this study are to understand the changes in body weight of breastfeeding mothers during long-term follow-up and preliminarily explore the relationship between maternal body weight and human milk composition,including macronutrients,leptin,and adiponectin.Methods:The study included a longitudinal cohort(122 mothers),and a cross-sectional cohort(37 mothers).The human milk,maternal weight,and dietary surveys were collected in the longitudinal cohort at different follow-up time points(1-14 days postpartum,2-4 months postpartum,5-7 months postpartum,and 12-17 months postpartum).The maternal body weight was analyzed using the responses in the survey questionnaires.A milk analyzer based on the mid-infrared spectroscopy(MIRS)was used to determine milk composition,and nutrition analysis software evaluated dietary intakes.In the cross-sectional cohort,participating mothers were asked to provide blood and human milk samples and pertinent information related to maternal body composition.Maternal body composition was measured by bioelectrical impedance analysis(BIA),while ELISA analyzed leptin and adiponectin in milk and serum.Results:At 5-7 months postpartum,the PPWR of breastfeeding mothers was(2.46±3.59)kg.At 12-17 months postpartum,the PPWR was(0.98±4.06)kg.PPWR was found to be negatively correlated with milk fat content within 14 days postpartum and positively correlated at 2-4 months postpartum.In addition,the maternal weight and body muscle mass were positively correlated with leptin and adiponectin in milk.Plasma leptin was positively correlated with the mother’s body weight,body mass index(BMI),FAT percentage,and body fat mass,while plasma adiponectin did not correlate with any parameter.The results also indicate that the PPWR did not correlate with leptin and adiponectin in plasma or milk.Conclusions:Breastfeeding mothers may retain considerable weight gain one year after delivery.Human milk composition may be related to changes in maternal body weight.Leptin and adiponectin in breast milk and leptin in plasma are associated with the maternal body composition.This study supports the notion that maternal nutritional status may affect offspring health through lactation,and future research should focus on exploring weight management of postpartum mothers.展开更多
Rolling stock manufacturers are finding structural solutions to reduce power required by the vehicles,and the lightweight design of the car body represents a possible solution.Optimization processes and innovative mat...Rolling stock manufacturers are finding structural solutions to reduce power required by the vehicles,and the lightweight design of the car body represents a possible solution.Optimization processes and innovative materials can be combined in order to achieve this goal.In this framework,we propose the redesign and optimization process of the car body roof for a light rail vehicle,introducing a sandwich structure.Bonded joint was used as a fastening system.The project was carried out on a single car of a modern tram platform.This preliminary numerical work was developed in two main steps:redesign of the car body structure and optimization of the innovated system.Objective of the process was the mass reduction of the whole metallic structure,while the constraint condition was imposed on the first frequency of vibration of the system.The effect of introducing a sandwich panel within the roof assembly was evaluated,focusing on the mechanical and dynamic performances of the whole car body.A mass saving of 63%on the optimized components was achieved,corresponding to a 7.6%if compared to the complete car body shell.In addition,a positive increasing of 17.7%on the first frequency of vibration was observed.Encouraging results have been achieved in terms of weight reduction and mechanical behaviour of the innovated car body.展开更多
Objective:This study explored the content and change trend of osteopontin(OPN)in breast milk and analyzed the relationship between OPN in breast milk and maternal body composition.Methods:Breast-feeding mothers were r...Objective:This study explored the content and change trend of osteopontin(OPN)in breast milk and analyzed the relationship between OPN in breast milk and maternal body composition.Methods:Breast-feeding mothers were recruited in Xinhua Hospital to collect breast milk and provide pertinent information.The content of OPN in breast milk was determined by enzyme-linked immunosorbent assay(ELISA).Determination of protein content in human milk was performed via the BCA method.The maternal body composition was determined by the bioelectrical impedance method.Serum glucocorticoid receptorα,adiponectin,insulin,and leptin were determined by ELISA.SPSS 25 was used for statistical analysis.Results:In the longitudinal cohort,106 mothers provided 318 milk samples at different lactation periods.The results indicate that the OPN showed dynamic changes.OPN levels were(343.2±163.5)mg/L during 1-14 days postpartum,(228.4±121.5)mg/L during 2-4 months postpartum,and(204.8±100.6)mg/L during 5-7 months postpartum.The content of OPN was very high in the first 1-14 days postpartum and then decreased.Compared with early postpartum milk,the OPN content of mature milk showed a significant relationship with maternal weight-related parameters.Additional body composition analysis was performed in 88 women at the mature milk phase.The results show that the OPN in milk is related to the mother’s body composition,especially the content of skeletal muscle mass,but not to relevant humoral factors.Conclusions:The levels of OPN in human milk of Chinese mothers showed dynamic changes with the extension of lactation time.The OPN in human milk was related to the mother’s body composition but not related to related humoral factors.展开更多
Background: An adequate hydration status is critical to ensure efficiency during mental and physical activities.Our goal was to assess the hydration status of a Spanish group of aeronautical military men and to determ...Background: An adequate hydration status is critical to ensure efficiency during mental and physical activities.Our goal was to assess the hydration status of a Spanish group of aeronautical military men and to determine the association of hydration status with body composition and anxiety.Methods: A total of 188 men were evaluated through a validated hydration questionnaire, anthropometric and biochemical parameters, and an anxiety questionnaire. Based on these methods, the criteria of hydration were established.Results: Of the total sample, 81% met the hydration criteria(urine color = well hydrated, water balance ≥0 ml, and total water intake/weight ≥35 ml/kg), and 19% did not meet the hydration criteria(urine color = not sufficiently hydrated or dehydrated, water balance <0 ml, and total water intake/weight <35 ml/kg). Subjects not meeting the hydration criteria had lower urine pH, negative water balance, and lower water intake. The latter also had higher anxiety status(score=4 vs. 3, P=0.026), weight [(84.7±10.5) kg vs.(80.5±10.2) kg], body mass index [(26.3±3.1) kg/m;vs.(25.2±2.8) kg/m;], body fat [(22.3±5.6)% vs.(18.3±6.5)%], urine specific gravity, and urine color. Using a logistic binary regression model, hydration status was related significantly with the percentage of body fat(P=0.004), but no relation was found with age, comorbidities, or medications. Furthermore, total water intake/weight was positively correlated with percentage of body water(r=0.357, P=0.000) and negatively with body fat(kg)(r=–0.427, P=0.000), percentage of body fat(r=–0.405, P=0.000), and waist/hip ratio(r=–0.223, P=0.002). Based on a linear regression model, total water intake/weight was related significantly with percentage of body fat(P=0.001) and percentage of body water content(P=0.035). No relation was found, however, with waist/hip ratio, age, comorbidities, or medications.Conclusions: These findings all suggest a relationship between hydration status and body composition but also set the bases for future studies that relate hydration status and anxiety status. These results can be used to improve the hydration status and body composition of military personnel.展开更多
Significance of body material and temperature variation on burning time and burning rate of Si/Pb O/Pb_3O_4/FG and B/BaCrO_4/FG pyrotechnic delay compositions were experimentally studied. Brass and stainless steel wer...Significance of body material and temperature variation on burning time and burning rate of Si/Pb O/Pb_3O_4/FG and B/BaCrO_4/FG pyrotechnic delay compositions were experimentally studied. Brass and stainless steel were used as delay body materials. High resolution oscilloscope and a customized chronometer were simultaneously used for the measurement of burning time and burning rate. Results reveal that brass material with controlled column dimensions reduced the variation in burning time of Si/Pb O/Pb_3O_4/FG delay mixture from 7.43% to 4.17% and that of B/Ba CrO_4/FG mixture from 16.83% to 9.39%.Similarly the variation in burning rate was reduced from 7.57% to 4.12% and from 17% to 9.69% for Si/Pb O/Pb_3O_4/FG and B/BaCrO_4/FG mixtures respectively. Si/PbO/Pb_3O_4/FG delay mixture was also subjected to temperature ranging from -54℃ up to+100℃. The burning rate of this composition varied linearly with temperature. Burning rate increased from 28.01 mm/s to 34.38 mm/s when the temperature was varied from -54℃ to +100℃.展开更多
Two classes of composite materials are considered: classical metaleceramic composites with reinforcing hard inclusions as well as hard ceramics matrix with soft gel inclusions. Movable cellular automaton method is use...Two classes of composite materials are considered: classical metaleceramic composites with reinforcing hard inclusions as well as hard ceramics matrix with soft gel inclusions. Movable cellular automaton method is used for modeling the mechanical behaviors of such different heterogeneous materials. The method is based on particle approach and may be considered as a kind of discrete element method. The main feature of the method is the use of many-body forces of inter-element interaction within the formalism of simply deformable element approximation. It was shown that the strength of reinforcing particles and the width of particle-binder interphase boundaries had determining influence on the service characteristics of metaleceramic composite. In particular, the increasing of strength of carbide inclusions may lead to significant increase in the strength and ultimate strain of composite material. On the example of porous zirconia ceramics it was shown that the change in the mechanical properties of pore surface leads to the corresponding change in effective elastic modulus and strength limit of the ceramic sample. The less is the pore size, the more is this effect. The increase in the elastic properties of pore surface of ceramics may reduce its fracture energy.展开更多
基金supported by grants from the Shanghai Key Laboratory of Pediatric Gastroenterology and Nutrition(17dz2272000)Foundation of Shanghai Municipal Health Commission(Key weak discipline construction project 2019ZB0101)the Scientific research fund of China Nutrition Society(CNSHPNK2021-16)。
文摘Objective:Postpartum weight retention(PPWR)is a common problem among women after childbirth.The main objectives of this study are to understand the changes in body weight of breastfeeding mothers during long-term follow-up and preliminarily explore the relationship between maternal body weight and human milk composition,including macronutrients,leptin,and adiponectin.Methods:The study included a longitudinal cohort(122 mothers),and a cross-sectional cohort(37 mothers).The human milk,maternal weight,and dietary surveys were collected in the longitudinal cohort at different follow-up time points(1-14 days postpartum,2-4 months postpartum,5-7 months postpartum,and 12-17 months postpartum).The maternal body weight was analyzed using the responses in the survey questionnaires.A milk analyzer based on the mid-infrared spectroscopy(MIRS)was used to determine milk composition,and nutrition analysis software evaluated dietary intakes.In the cross-sectional cohort,participating mothers were asked to provide blood and human milk samples and pertinent information related to maternal body composition.Maternal body composition was measured by bioelectrical impedance analysis(BIA),while ELISA analyzed leptin and adiponectin in milk and serum.Results:At 5-7 months postpartum,the PPWR of breastfeeding mothers was(2.46±3.59)kg.At 12-17 months postpartum,the PPWR was(0.98±4.06)kg.PPWR was found to be negatively correlated with milk fat content within 14 days postpartum and positively correlated at 2-4 months postpartum.In addition,the maternal weight and body muscle mass were positively correlated with leptin and adiponectin in milk.Plasma leptin was positively correlated with the mother’s body weight,body mass index(BMI),FAT percentage,and body fat mass,while plasma adiponectin did not correlate with any parameter.The results also indicate that the PPWR did not correlate with leptin and adiponectin in plasma or milk.Conclusions:Breastfeeding mothers may retain considerable weight gain one year after delivery.Human milk composition may be related to changes in maternal body weight.Leptin and adiponectin in breast milk and leptin in plasma are associated with the maternal body composition.This study supports the notion that maternal nutritional status may affect offspring health through lactation,and future research should focus on exploring weight management of postpartum mothers.
文摘Rolling stock manufacturers are finding structural solutions to reduce power required by the vehicles,and the lightweight design of the car body represents a possible solution.Optimization processes and innovative materials can be combined in order to achieve this goal.In this framework,we propose the redesign and optimization process of the car body roof for a light rail vehicle,introducing a sandwich structure.Bonded joint was used as a fastening system.The project was carried out on a single car of a modern tram platform.This preliminary numerical work was developed in two main steps:redesign of the car body structure and optimization of the innovated system.Objective of the process was the mass reduction of the whole metallic structure,while the constraint condition was imposed on the first frequency of vibration of the system.The effect of introducing a sandwich panel within the roof assembly was evaluated,focusing on the mechanical and dynamic performances of the whole car body.A mass saving of 63%on the optimized components was achieved,corresponding to a 7.6%if compared to the complete car body shell.In addition,a positive increasing of 17.7%on the first frequency of vibration was observed.Encouraging results have been achieved in terms of weight reduction and mechanical behaviour of the innovated car body.
基金supported by grants from the Shanghai Key Laboratory of Pediatric Gastroenterology and Nutrition(17dz2272000)the National Natural Science Foundation of China-Key Program(81630039)。
文摘Objective:This study explored the content and change trend of osteopontin(OPN)in breast milk and analyzed the relationship between OPN in breast milk and maternal body composition.Methods:Breast-feeding mothers were recruited in Xinhua Hospital to collect breast milk and provide pertinent information.The content of OPN in breast milk was determined by enzyme-linked immunosorbent assay(ELISA).Determination of protein content in human milk was performed via the BCA method.The maternal body composition was determined by the bioelectrical impedance method.Serum glucocorticoid receptorα,adiponectin,insulin,and leptin were determined by ELISA.SPSS 25 was used for statistical analysis.Results:In the longitudinal cohort,106 mothers provided 318 milk samples at different lactation periods.The results indicate that the OPN showed dynamic changes.OPN levels were(343.2±163.5)mg/L during 1-14 days postpartum,(228.4±121.5)mg/L during 2-4 months postpartum,and(204.8±100.6)mg/L during 5-7 months postpartum.The content of OPN was very high in the first 1-14 days postpartum and then decreased.Compared with early postpartum milk,the OPN content of mature milk showed a significant relationship with maternal weight-related parameters.Additional body composition analysis was performed in 88 women at the mature milk phase.The results show that the OPN in milk is related to the mother’s body composition,especially the content of skeletal muscle mass,but not to relevant humoral factors.Conclusions:The levels of OPN in human milk of Chinese mothers showed dynamic changes with the extension of lactation time.The OPN in human milk was related to the mother’s body composition but not related to related humoral factors.
基金partially supported by the “Centro de Instrucción Militar Aeroespacial”(CIMA)。
文摘Background: An adequate hydration status is critical to ensure efficiency during mental and physical activities.Our goal was to assess the hydration status of a Spanish group of aeronautical military men and to determine the association of hydration status with body composition and anxiety.Methods: A total of 188 men were evaluated through a validated hydration questionnaire, anthropometric and biochemical parameters, and an anxiety questionnaire. Based on these methods, the criteria of hydration were established.Results: Of the total sample, 81% met the hydration criteria(urine color = well hydrated, water balance ≥0 ml, and total water intake/weight ≥35 ml/kg), and 19% did not meet the hydration criteria(urine color = not sufficiently hydrated or dehydrated, water balance <0 ml, and total water intake/weight <35 ml/kg). Subjects not meeting the hydration criteria had lower urine pH, negative water balance, and lower water intake. The latter also had higher anxiety status(score=4 vs. 3, P=0.026), weight [(84.7±10.5) kg vs.(80.5±10.2) kg], body mass index [(26.3±3.1) kg/m;vs.(25.2±2.8) kg/m;], body fat [(22.3±5.6)% vs.(18.3±6.5)%], urine specific gravity, and urine color. Using a logistic binary regression model, hydration status was related significantly with the percentage of body fat(P=0.004), but no relation was found with age, comorbidities, or medications. Furthermore, total water intake/weight was positively correlated with percentage of body water(r=0.357, P=0.000) and negatively with body fat(kg)(r=–0.427, P=0.000), percentage of body fat(r=–0.405, P=0.000), and waist/hip ratio(r=–0.223, P=0.002). Based on a linear regression model, total water intake/weight was related significantly with percentage of body fat(P=0.001) and percentage of body water content(P=0.035). No relation was found, however, with waist/hip ratio, age, comorbidities, or medications.Conclusions: These findings all suggest a relationship between hydration status and body composition but also set the bases for future studies that relate hydration status and anxiety status. These results can be used to improve the hydration status and body composition of military personnel.
文摘Significance of body material and temperature variation on burning time and burning rate of Si/Pb O/Pb_3O_4/FG and B/BaCrO_4/FG pyrotechnic delay compositions were experimentally studied. Brass and stainless steel were used as delay body materials. High resolution oscilloscope and a customized chronometer were simultaneously used for the measurement of burning time and burning rate. Results reveal that brass material with controlled column dimensions reduced the variation in burning time of Si/Pb O/Pb_3O_4/FG delay mixture from 7.43% to 4.17% and that of B/Ba CrO_4/FG mixture from 16.83% to 9.39%.Similarly the variation in burning rate was reduced from 7.57% to 4.12% and from 17% to 9.69% for Si/Pb O/Pb_3O_4/FG and B/BaCrO_4/FG mixtures respectively. Si/PbO/Pb_3O_4/FG delay mixture was also subjected to temperature ranging from -54℃ up to+100℃. The burning rate of this composition varied linearly with temperature. Burning rate increased from 28.01 mm/s to 34.38 mm/s when the temperature was varied from -54℃ to +100℃.
基金the Projects Nos. III.23.2.3 (I.S. Konovalenko, S.P. Buyakova) and III.23.2.4 (S.G. Psakhie) of the Basic Scientific Research Program of State Academies of Sciences for 2013e2020the RFBR Project No. 12-01-00805-a (A.Yu. Smolin, E.V. Shilko)the grant No. 14-19-00718 of the Russian Science Foundation (A.Yu. Smolin, E.V. Shilko, S.V. Astafurov)
文摘Two classes of composite materials are considered: classical metaleceramic composites with reinforcing hard inclusions as well as hard ceramics matrix with soft gel inclusions. Movable cellular automaton method is used for modeling the mechanical behaviors of such different heterogeneous materials. The method is based on particle approach and may be considered as a kind of discrete element method. The main feature of the method is the use of many-body forces of inter-element interaction within the formalism of simply deformable element approximation. It was shown that the strength of reinforcing particles and the width of particle-binder interphase boundaries had determining influence on the service characteristics of metaleceramic composite. In particular, the increasing of strength of carbide inclusions may lead to significant increase in the strength and ultimate strain of composite material. On the example of porous zirconia ceramics it was shown that the change in the mechanical properties of pore surface leads to the corresponding change in effective elastic modulus and strength limit of the ceramic sample. The less is the pore size, the more is this effect. The increase in the elastic properties of pore surface of ceramics may reduce its fracture energy.
