The Tyrannosauridae,which is characterized by specialized pachydont dentition and putative bone-cracking predatory strategies,is one of the most extensively studied theropod lineages.Although tooth replacement pattern...The Tyrannosauridae,which is characterized by specialized pachydont dentition and putative bone-cracking predatory strategies,is one of the most extensively studied theropod lineages.Although tooth replacement patterns,crucial for understanding feeding behaviors,have been thoroughly studied in this group,studies on non-tyrannosaurid tyrannosauroids are relatively scarce.This study utilizes high-resolution CT data to investigate the tooth replacement pattern in two specimens of Guanlong wucaii,a Late Jurassic tyrannosauroid,and provides insights into the evolution of tooth replacement across Tyrannosauroidea.Second-generation replacement teeth,a rarity observed mainly in giant predatory theropods(e.g.some tyrannosaurids),were detected in the dentary dentition of the juvenile Guanlong.Zahnreihen reconstructions display a consistent cephalad alternating tooth replacement pattern in the maxilla and the dentary of both of the examined individuals,with Z-spacing values exceeding 2.0.As Guanlong grows,the Z-spacing value in the maxillary dentition increases,resembling the ontogenetic changes documented in the Tyrannosauridae.Additionally,like Tarbosaurus,Guanlong also displays a discontinuity between the tooth replacement waves at the premaxilla-maxilla boundary.This study thus demonstrates that some tyrannosaurid-like tooth replacement patterns were acquired before the origin of the Tyrannosauridae.展开更多
A notable portion of cachelines in real-world workloads exhibits inner non-uniform access behaviors.However,modern cache management rarely considers this fine-grained feature,which impacts the effective cache capacity...A notable portion of cachelines in real-world workloads exhibits inner non-uniform access behaviors.However,modern cache management rarely considers this fine-grained feature,which impacts the effective cache capacity of contemporary high-performance spacecraft processors.To harness these non-uniform access behaviors,an efficient cache replacement framework featuring an auxiliary cache specifically designed to retain evicted hot data was proposed.This framework reconstructs the cache replacement policy,facilitating data migration between the main cache and the auxiliary cache.Unlike traditional cacheline-granularity policies,the approach excels at identifying and evicting infrequently used data,thereby optimizing cache utilization.The evaluation shows impressive performance improvement,especially on workloads with irregular access patterns.Benefiting from fine granularity,the proposal achieves superior storage efficiency compared with commonly used cache management schemes,providing a potential optimization opportunity for modern resource-constrained processors,such as spacecraft processors.Furthermore,the framework complements existing modern cache replacement policies and can be seamlessly integrated with minimal modifications,enhancing their overall efficacy.展开更多
The reliability of the product sold under a warranty is usually maintained by the manufacturer during the warranty period. After the expiry of the warranty, however, the consumer confronts a problem about how to maint...The reliability of the product sold under a warranty is usually maintained by the manufacturer during the warranty period. After the expiry of the warranty, however, the consumer confronts a problem about how to maintain the reliability of the product. This paper proposes, from the consumer's perspective, a replacement policy after the extended warranty, under the assumption that the product is sold under the renewable free replacement warranty (RFRW) policy in which the replacement is dependent on the repair-cost threshold. The proposed replacement policy is the replacement after the extended warranty is performed by the consumer based on the repair-cost threshold or preventive replacement (PR) age, which are decision variables. The expected cost rate model is derived from the consumer's perspective. The existence and uniqueness of the optimal solution that minimizes the expected cost rate per unit time are offered. Finally, a numerical example is presented to exemplify the proposed model.展开更多
This paper develops a new replacement policy for a system with multiple spare units.An optimal replacement period is determined by maximizing the mean time to failure of the system.We show that there exists a finite a...This paper develops a new replacement policy for a system with multiple spare units.An optimal replacement period is determined by maximizing the mean time to failure of the system.We show that there exists a finite and unique optimal replacement period T for units with strictly increasing failure rates. We also proof that the optimal repIacement period for a system with spares is decreasing in k. Furthermore, an algorithm is presented to get the optimal replacement period and a numerical example is given to illustrate the result. with strictly展开更多
Background Dental implants have been widely used in the last few decades.However,patients with insufficient bone height need reconstructive surgeries before implant insertion.Distraction implant(Dl)has been invented t...Background Dental implants have been widely used in the last few decades.However,patients with insufficient bone height need reconstructive surgeries before implant insertion.Distraction implant(Dl)has been invented to simplify the treatment procedure,but the shortcomings of Dl have limited its clinical use.We introduced biodegradable polyester to a novel Dl,called biodegradable interference distraction implant(BIDI).The purpose of this study was to assess the radiological,histological,and biomechanical properties of BIDI in animal models.Methods BIDIs were manufactured and inserted into the atrophied mandibles of 6 dogs.展开更多
Objective Cardiopulmonary exercise testing(CPET)is helpful to identify right ventriclar(RV)dysfunction in patients with rapair of Tetralogy of Fallot(rTOF),but its predictive value on early outcomes of pulmonary valve...Objective Cardiopulmonary exercise testing(CPET)is helpful to identify right ventriclar(RV)dysfunction in patients with rapair of Tetralogy of Fallot(rTOF),but its predictive value on early outcomes of pulmonary valve replacement(PVR)of these patients is unclear when similar preoperative ventricular size and function in cardiovascular magnetic resonance(CMR)exist.The aim of this study is to evaluate whether CPET is useful to predict the early outcomes of rTOF patients after PVR.展开更多
Component reallocation(CR)is receiving increasing attention in many engineering systems with functionally interchangeable and unbalanced degradation components.This paper studies a CR and system replacement maintenanc...Component reallocation(CR)is receiving increasing attention in many engineering systems with functionally interchangeable and unbalanced degradation components.This paper studies a CR and system replacement maintenance policy of series repairable systems,which undergoes minimal repairs for each emergency failure of components,and considers constant downtime and cost of minimal repair,CR and system replacement.Two binary mixed integer nonlinear programming models are respectively established to determine the assignment of CR,and the uptime right before CR and system replacement with the objective of minimizing the system average maintenance cost and maximizing the system availability.Further,we derive the optimal uptime right before system replacement with maximization of the system availability,and then give the relationship between the system availability and the component failure rate.Finally,numerical examples show that the CR and system replacement maintenance policy can effectively reduce the system average maintenance cost and improve the system availability,and further give the sensitivity analysis and insights of the CR and system replacement maintenance policy.展开更多
Hormone replacement therapy (HRT) was initiated almost half a century ago to treat menopausal symptoms. Initially, its use remained limited even among symptomatic women and the move toward postmenopausal hormone use f...Hormone replacement therapy (HRT) was initiated almost half a century ago to treat menopausal symptoms. Initially, its use remained limited even among symptomatic women and the move toward postmenopausal hormone use for disease prevention came later. Improved treatment schedules and delivery systems expanded the use of HRT worldwide. However, large trials of postmenopausal hormones with disease outcomes were even later in coming and today HRT has become a specialized, multidisciplinary area of research. As the population continues to grow older, there has been an increased focus on the effects of ageing. HRT may affect length and quality of life through disease prevention. It may have possible beneficial effects on cognition, on the incidence of hip fracture, myocardial infarction and stroke, and adverse effects on the incidence of breast cancer, endometrial cancer, and venous thromboembolism.Today’s attitudes about the hormonal treatments for the menopausal transition have moved from expansive optimism to contracting disappointment amidst safety concerns and equivocal results and faces greater skepticism and scrutiny. The health and well being of large numbers of women are at stake, and researchers, clinicians and the general public are watching and weighing the options.展开更多
文摘The Tyrannosauridae,which is characterized by specialized pachydont dentition and putative bone-cracking predatory strategies,is one of the most extensively studied theropod lineages.Although tooth replacement patterns,crucial for understanding feeding behaviors,have been thoroughly studied in this group,studies on non-tyrannosaurid tyrannosauroids are relatively scarce.This study utilizes high-resolution CT data to investigate the tooth replacement pattern in two specimens of Guanlong wucaii,a Late Jurassic tyrannosauroid,and provides insights into the evolution of tooth replacement across Tyrannosauroidea.Second-generation replacement teeth,a rarity observed mainly in giant predatory theropods(e.g.some tyrannosaurids),were detected in the dentary dentition of the juvenile Guanlong.Zahnreihen reconstructions display a consistent cephalad alternating tooth replacement pattern in the maxilla and the dentary of both of the examined individuals,with Z-spacing values exceeding 2.0.As Guanlong grows,the Z-spacing value in the maxillary dentition increases,resembling the ontogenetic changes documented in the Tyrannosauridae.Additionally,like Tarbosaurus,Guanlong also displays a discontinuity between the tooth replacement waves at the premaxilla-maxilla boundary.This study thus demonstrates that some tyrannosaurid-like tooth replacement patterns were acquired before the origin of the Tyrannosauridae.
文摘A notable portion of cachelines in real-world workloads exhibits inner non-uniform access behaviors.However,modern cache management rarely considers this fine-grained feature,which impacts the effective cache capacity of contemporary high-performance spacecraft processors.To harness these non-uniform access behaviors,an efficient cache replacement framework featuring an auxiliary cache specifically designed to retain evicted hot data was proposed.This framework reconstructs the cache replacement policy,facilitating data migration between the main cache and the auxiliary cache.Unlike traditional cacheline-granularity policies,the approach excels at identifying and evicting infrequently used data,thereby optimizing cache utilization.The evaluation shows impressive performance improvement,especially on workloads with irregular access patterns.Benefiting from fine granularity,the proposal achieves superior storage efficiency compared with commonly used cache management schemes,providing a potential optimization opportunity for modern resource-constrained processors,such as spacecraft processors.Furthermore,the framework complements existing modern cache replacement policies and can be seamlessly integrated with minimal modifications,enhancing their overall efficacy.
基金supported by the National Natural Science Foundation of China(7147114771631001)+1 种基金the Basic Research Project of Natural Science in Shaanxi Province(2015JQ7273)the 111 Project(B13044)
文摘The reliability of the product sold under a warranty is usually maintained by the manufacturer during the warranty period. After the expiry of the warranty, however, the consumer confronts a problem about how to maintain the reliability of the product. This paper proposes, from the consumer's perspective, a replacement policy after the extended warranty, under the assumption that the product is sold under the renewable free replacement warranty (RFRW) policy in which the replacement is dependent on the repair-cost threshold. The proposed replacement policy is the replacement after the extended warranty is performed by the consumer based on the repair-cost threshold or preventive replacement (PR) age, which are decision variables. The expected cost rate model is derived from the consumer's perspective. The existence and uniqueness of the optimal solution that minimizes the expected cost rate per unit time are offered. Finally, a numerical example is presented to exemplify the proposed model.
文摘This paper develops a new replacement policy for a system with multiple spare units.An optimal replacement period is determined by maximizing the mean time to failure of the system.We show that there exists a finite and unique optimal replacement period T for units with strictly increasing failure rates. We also proof that the optimal repIacement period for a system with spares is decreasing in k. Furthermore, an algorithm is presented to get the optimal replacement period and a numerical example is given to illustrate the result. with strictly
基金supported by the National Natural Science Foundation of China(No. 30900284,No.31100668,and No.31070873)
文摘Background Dental implants have been widely used in the last few decades.However,patients with insufficient bone height need reconstructive surgeries before implant insertion.Distraction implant(Dl)has been invented to simplify the treatment procedure,but the shortcomings of Dl have limited its clinical use.We introduced biodegradable polyester to a novel Dl,called biodegradable interference distraction implant(BIDI).The purpose of this study was to assess the radiological,histological,and biomechanical properties of BIDI in animal models.Methods BIDIs were manufactured and inserted into the atrophied mandibles of 6 dogs.
文摘Objective Cardiopulmonary exercise testing(CPET)is helpful to identify right ventriclar(RV)dysfunction in patients with rapair of Tetralogy of Fallot(rTOF),but its predictive value on early outcomes of pulmonary valve replacement(PVR)of these patients is unclear when similar preoperative ventricular size and function in cardiovascular magnetic resonance(CMR)exist.The aim of this study is to evaluate whether CPET is useful to predict the early outcomes of rTOF patients after PVR.
基金supported by the National Natural Science Foundation of China(72101025,72271049)the Fundamental Research Funds for the Central Universities(FRF-TP-20-073A1)the China Postdoct oral Science Foundation(2021M690349)。
文摘Component reallocation(CR)is receiving increasing attention in many engineering systems with functionally interchangeable and unbalanced degradation components.This paper studies a CR and system replacement maintenance policy of series repairable systems,which undergoes minimal repairs for each emergency failure of components,and considers constant downtime and cost of minimal repair,CR and system replacement.Two binary mixed integer nonlinear programming models are respectively established to determine the assignment of CR,and the uptime right before CR and system replacement with the objective of minimizing the system average maintenance cost and maximizing the system availability.Further,we derive the optimal uptime right before system replacement with maximization of the system availability,and then give the relationship between the system availability and the component failure rate.Finally,numerical examples show that the CR and system replacement maintenance policy can effectively reduce the system average maintenance cost and improve the system availability,and further give the sensitivity analysis and insights of the CR and system replacement maintenance policy.
文摘Hormone replacement therapy (HRT) was initiated almost half a century ago to treat menopausal symptoms. Initially, its use remained limited even among symptomatic women and the move toward postmenopausal hormone use for disease prevention came later. Improved treatment schedules and delivery systems expanded the use of HRT worldwide. However, large trials of postmenopausal hormones with disease outcomes were even later in coming and today HRT has become a specialized, multidisciplinary area of research. As the population continues to grow older, there has been an increased focus on the effects of ageing. HRT may affect length and quality of life through disease prevention. It may have possible beneficial effects on cognition, on the incidence of hip fracture, myocardial infarction and stroke, and adverse effects on the incidence of breast cancer, endometrial cancer, and venous thromboembolism.Today’s attitudes about the hormonal treatments for the menopausal transition have moved from expansive optimism to contracting disappointment amidst safety concerns and equivocal results and faces greater skepticism and scrutiny. The health and well being of large numbers of women are at stake, and researchers, clinicians and the general public are watching and weighing the options.
