Background:Current treatment options for human epidermal growth factor receptor 2(HER2)-overexpressing gastric cancer at third-line have shown limited clinical benefit.Further,there is no specific treatment for HER2 i...Background:Current treatment options for human epidermal growth factor receptor 2(HER2)-overexpressing gastric cancer at third-line have shown limited clinical benefit.Further,there is no specific treatment for HER2 immunohistochemistry(IHC)2+and fluorescence in-situ hybridization-negative patients.Here,we report the efficacy and safety of a novel anti-HER2 antibody RC48 for patients with HER2-overexpressing,advanced gastric or gastroesophageal junction cancer.Methods:Patients with HER2-overexpressing(IHC 2+or 3+),locally advanced or metastatic gastric or gastroesophageal junction cancer who were under at least second-line therapy were eligible and received RC482.5 mg/kg alone every 2 weeks.The primary endpoint was the objective response rate(ORR)assessed by an independent review committee.Secondary endpoints included progressionfree survival(PFS),overall survival(OS),duration of response,time to progression,disease control rate,and safety.Results:Of 179 patients screened,125 were eligible and received RC48 treatment.The ORR was 24.8%(95%confidence interval[CI]:17.5%-33.3%).The median PFS and OS were 4.1 months(95%CI:3.7-4.9 months)and 7.9 months(95%CI:6.7-9.9 months),respectively.The most frequently reported adverse events were decreased white blood cell count(53.6%),asthenia(53.6%),hair loss(53.6%),decreased neutrophil count(52.0%),anemia(49.6%),and increased aspartate aminotransferase level(43.2%).Serious adverse events(SAEs)occurred in 45(36.0%)patients,and RC48-related SAEs were mainly decreased neutrophil count(3.2%).Seven patients had adverse events that led to death were not RC48-related.Conclusions:RC48 showed promising activity with manageable safety,suggesting potential application in patients with HER2-overexpressing,advanced gastric or gastroesophageal junction cancer who have previously received at least two lines of chemotherapy.展开更多
Antibody–drug conjugate(ADC)is typically composed of a monoclonal antibody(mAbs)covalently attached to a cytotoxic drug via a chemical linker.It combines both the advantages of highly specific targeting ability and h...Antibody–drug conjugate(ADC)is typically composed of a monoclonal antibody(mAbs)covalently attached to a cytotoxic drug via a chemical linker.It combines both the advantages of highly specific targeting ability and highly potent killing effect to achieve accurate and efficient elimination of cancer cells,which has become one of the hotspots for the research and development of anticancer drugs.Since the first ADC,Mylotarg®(gemtuzumab ozogamicin),was approved in 2000 by the US Food and Drug Administration(FDA),there have been 14 ADCs received market approval so far worldwide.Moreover,over 100 ADC candidates have been investigated in clinical stages at present.This kind of new anti-cancer drugs,known as“biological missiles”,is leading a new era of targeted cancer therapy.Herein,we conducted a review of the history and general mechanism of action of ADCs,and then briefly discussed the molecular aspects of key components of ADCs and the mechanisms by which these key factors influence the activities of ADCs.Moreover,we also reviewed the approved ADCs and other promising candidates in phase-3 clinical trials and discuss the current challenges and future perspectives for the development of next generations,which provide insights for the research and development of novel cancer therapeutics using ADCs.展开更多
Abstract. Conjugate gradient methods are very important methods for unconstrainedoptimization, especially for large scale problems. In this paper, we propose a new conjugategradient method, in which the technique of n...Abstract. Conjugate gradient methods are very important methods for unconstrainedoptimization, especially for large scale problems. In this paper, we propose a new conjugategradient method, in which the technique of nonmonotone line search is used. Under mildassumptions, we prove the global convergence of the method. Some numerical results arealso presented.展开更多
Accelerated degradation test is a useful approach to predict the product lifetime at the normal use stress level, especially for highly reliable products. Two kinds of the lifetime prediction based on Gamma processes ...Accelerated degradation test is a useful approach to predict the product lifetime at the normal use stress level, especially for highly reliable products. Two kinds of the lifetime prediction based on Gamma processes were studied. One was to predict the lifetime of the population from accelerated degradation data, and the other was to predict the lifetime of an individual by taking the accelerated degradation data as prior information. For an extensive application, the Gamma process with a time transformation and random effects was considered. A novel contribution is that a deducing method for determining the relationships between the shape and scale parameters of Gamma processes and accelerated stresses was presented. When predicting the lifetime of an individual, Bayesian inference methods were adopted to improve the prediction accuracy, in which the conjugate prior distribution and the non-conjugate prior distribution of random parameters were studied. The conjugate prior distribution only considers the random effect of the scale parameter while the non-conjugate prior distribution considers the random effects of both the scale and shape parameter. The application and usefulness of the proposed method was demonstrated by the accelerated degradation data of carbon-film resistors.展开更多
AIM: To explore the role and potential mechanism of miR-30 b regulation of autophagy in hepatic ischemiareperfusion injury(IRI).METHODS: An animal model of hepatic IRI was generated in C57BL/6 mice. For in vitro studi...AIM: To explore the role and potential mechanism of miR-30 b regulation of autophagy in hepatic ischemiareperfusion injury(IRI).METHODS: An animal model of hepatic IRI was generated in C57BL/6 mice. For in vitro studies, AML12 cells were immersed in mineral oil for 1 h and then cultured in complete Dulbecco's Modified Eagle's Medium(DMEM)/F12 to simulate IRI. Mice and cells were transfected with miR-30 b agomir/mimics or antagomir/inhibitor to examine the effect of miR-30 b on autophagy to promote hepatic IRI. The expression of miR-30 b was measured by real-time polymerase chain reaction. Apoptotic cells were detected by terminal uridine nickend labeling(TUNEL) staining, and cell viability was detected by methylthiazole tetrazolium assay. The expression of light chain 3, autophagy-related gene(Atg)12, Atg5, P62, and caspase-3 were detected by western blotting analysis.RESULTS: miR-30 b levels were significantly downregulated after hepatic IRI, and the numbers of autophagosomes were increased in response to IRI both in vivo and in vitro. These findings demonstrate that low levels of miR-30 b could promote hepatic IRI. Furthermore, we found that miR-30 b interacted with Atg12-Atg5 conjugate by binding to Atg12. Overexpression of miR-30 b diminished Atg12 and Atg12-Atg5 conjugate levels, which promoted autophagy in response to IR. In contrast, downregulation of miR-30 b was associated with increased Atg12-Atg5 conjugate levels and increased autophagy.CONCLUSION: miR-30 b inhibited autophagy to alleviate hepatic ischemia-reperfusion injury via decreasing the Atg12-Atg5 conjugate.展开更多
Recent studies, focused on dihedral angles and intersection processes, have increased understandings of conjugate fault mechanisms. We present new 3-D seismic data and microstructural core analysis in a case study of ...Recent studies, focused on dihedral angles and intersection processes, have increased understandings of conjugate fault mechanisms. We present new 3-D seismic data and microstructural core analysis in a case study of a large conjugate strike-slip fault system from the intracratonic Tarim Basin, NW China. Within our study area, ＂X＂ type NE and NW trending faults occur within Cambrian- Ordovician carbonates. The dihedral angles of these conjugate faults have narrow ranges, 19~ to 62~ in the Cambrian and 26~ to 51~ in the Ordovician, and their modes are 42~ and 44~ respectively. These data are significantly different from the ~60~ predicted by the Coulomb fracture criterion. It is concluded that： （1） The dihedral angles of the conjugate faults were not controlled by confining pressure, which was low and associated with shallow burial; （2） As dihedral angles were not controlled by pressure they can be used to determine the shortening direction during faulting; （3） Sequential slip may have played an important role in forming conjugate fault intersections; （4） The conjugate fault system of the Tarim basin initiated as rhombic joints; these subsequently developed into sequentially active ＂X＂ type conjugate faults; followed by preferential development of the NW-trending faults; then reactivation of the NE trending faults. This intact rhombic conjugate fault system presents new insights into mechanisms of dihedral angle development, with particular relevance to intracratonic basins.展开更多
To study the seepage and deformation characteristics of coal at high temperatures,coal samples from six different regions were selected and subjected to computed tomography(CT)scanning studies.In conjunction with ANSY...To study the seepage and deformation characteristics of coal at high temperatures,coal samples from six different regions were selected and subjected to computed tomography(CT)scanning studies.In conjunction with ANSYS software,3 D reconstruction of CT images was used for the establishment of fluidsolid conjugate heat transfer model and coal thermal deformation model based on the microstructures of coal.In addition,the structure of coal was studied in 2 D and 3 D perspectives,followed by the analysis of seepage and deformation characteristics of coal at high temperatures.The results of this study indicated that porosity positively correlated with the fractal dimension,and the connectivity and seepage performances were roughly identical from 2 D and 3 D perspectives.As the porosity increased,the fractal dimension of coal samples became larger and the pore-fracture structures became more complex.As a result,the permeability of coal samples decreased.In the meantime,fluid was fully heated,generating high-temperature water at outlet.However,when the porosity was low,the outlet temperature was very high.The average deformation of coal skeleton with different pore-fracture structures at high temperatures showed a trend of initial increase and subsequent decrease with the increase of porosity and fractal dimension.The maximum deformation of coal skeleton positively correlated with connectivity but negatively correlated with the fractal dimension.展开更多
The convergence properties of the Fletcher-Reeves method for unconstrained optimization are further studied with the technique of generalized line search. Two conditions are given which guarantee the global convergenc...The convergence properties of the Fletcher-Reeves method for unconstrained optimization are further studied with the technique of generalized line search. Two conditions are given which guarantee the global convergence of the Fletcher-Reeves method using generalized Wolfe line searches or generalized Arjimo line searches, whereas an example is constructed showing that the conditions cannot be relaxed in certain senses.展开更多
The purpose of this paper is to give a selective survey on recent progress in random metric theory and its applications to conditional risk measures.This paper includes eight sections.Section 1 is a longer introductio...The purpose of this paper is to give a selective survey on recent progress in random metric theory and its applications to conditional risk measures.This paper includes eight sections.Section 1 is a longer introduction,which gives a brief introduction to random metric theory,risk measures and conditional risk measures.Section 2 gives the central framework in random metric theory,topological structures,important examples,the notions of a random conjugate space and the Hahn-Banach theorems for random linear functionals.Section 3 gives several important representation theorems for random conjugate spaces.Section 4 gives characterizations for a complete random normed module to be random reflexive.Section 5 gives hyperplane separation theorems currently available in random locally convex modules.Section 6 gives the theory of random duality with respect to the locally L0-convex topology and in particular a characterization for a locally L0-convex module to be L0-pre-barreled.Section 7 gives some basic results on L0-convex analysis together with some applications to conditional risk measures.Finally,Section 8 is devoted to extensions of conditional convex risk measures,which shows that every representable L∞-type of conditional convex risk measure and every continuous Lp-type of convex conditional risk measure(1 ≤ p < +∞) can be extended to an L∞F(E)-type of σ,λ(L∞F(E),L1F(E))-lower semicontinuous conditional convex risk measure and an LpF(E)-type of T,λ-continuous conditional convex risk measure(1 ≤ p < +∞),respectively.展开更多
In this paper we test different conjugate gradient (CG) methods for solving large-scale unconstrained optimization problems. The methods are divided in two groups: the first group includes five basic CG methods and th...In this paper we test different conjugate gradient (CG) methods for solving large-scale unconstrained optimization problems. The methods are divided in two groups: the first group includes five basic CG methods and the second five hybrid CG methods. A collection of medium-scale and large-scale test problems are drawn from a standard code of test problems, CUTE. The conjugate gradient methods are ranked according to the numerical results. Some remarks are given.展开更多
To study the temperature distribution and thermal-stress field in different service stages, a two-dimensional model of a turbine blade with thermal barrier coatings is developed, in which the conjugate heat transfer a...To study the temperature distribution and thermal-stress field in different service stages, a two-dimensional model of a turbine blade with thermal barrier coatings is developed, in which the conjugate heat transfer analysis and the decoupled thermal-stress calculation method are adopted. Based on the simulation results, it is found that a non-uniform distribution of temperature appears in different positions of the blade surface, which has directly impacted on stress field. The maximum temperature with a value of 1030 ℃ occurs at the leading edge. During the steady stage, the maximum stress of thermally grown oxide （TGO） appears in the middle of the suction side, reaching 3.75 GPa. At the end stage of cooling, the maximum compressive stress of TGO with a value of-3.5 GPa occurs at the leading edge. Thus, it can be predicted that during the steady stage the dangerous regions may locate at the suction side, while the leadine edge mav be more Drone to failure on cooling.展开更多
A class of regularized conjugate gradient methods is presented for solving the large sparse system of linear equations of which the coefficient matrix is an ill-conditioned symmetric positive definite matrix. The conv...A class of regularized conjugate gradient methods is presented for solving the large sparse system of linear equations of which the coefficient matrix is an ill-conditioned symmetric positive definite matrix. The convergence properties of these methods are discussed in depth, and the best possible choices of the parameters involved in the new methods are investigated in detail. Numerical computations show that the new methods are more efficient and robust than both classical relaxation methods and classical conjugate direction methods.展开更多
Two Armijo-type line searches are proposed in this paper for nonlinear conjugate gradient methods. Under these line searches, global convergence results are established for several famous conjugate gradient methods, i...Two Armijo-type line searches are proposed in this paper for nonlinear conjugate gradient methods. Under these line searches, global convergence results are established for several famous conjugate gradient methods, including the Fletcher-Reeves method, the Polak-Ribiere-Polyak method, and the conjugate descent method.展开更多
Objective： Nanoparticles are becoming an important method of targeted drug delivery. To evaluate the importance of folate-conjugated human serum albumin （HSA） magnetic nanoparticles （Folate-CDDP/HSA MNP）, we prep...Objective： Nanoparticles are becoming an important method of targeted drug delivery. To evaluate the importance of folate-conjugated human serum albumin （HSA） magnetic nanoparticles （Folate-CDDP/HSA MNP）, we prepared drug-loaded Folate-CDDP/HSA MNPs and characterized their features. Methods： First, folate was conjugated with HSA under the effect of a condensing agent, and the conjugating rate was evaluated by a colorimetric method using 2, 4, 6 - trinitrobenzene sulfonic acid. Second, under N., gas, Fe：~O1 magnetic nanomaterials were prepared and characterized by using transmission electron microscopy （TEM）, SEM-EDS and X-ray diffraction （XRD）. Finally, Folate-CDDP/HSA MNP was prepared by using a solvent evaporation technique. TEM was used to observe particle morphology. The particle size and distribution of the prepared complexes were determined by a Laser particle size analyzer. Drug loading volume and drug release were investigated by a high performance liquid chromatography method （HPLC） in vitro. Results： We successfully prepared folate-conjugated HSA and its conjugating rate was 27.26 μg/mg. Under TEM, Fe2O4 magnetic nanoparticles were highly electron density and had an even size distribution in the range of 10-20 nm. It was confirmed by SEM-EDS and XRD that Fe304 magnetic nanoparticles had been successfully prepared. Under TEM, drug-loaded magnetic nanoparticles were observed, which had a round shape, similar uniform size and smooth surface. Their average size was 79 nm which was determined by laser scattering, and they exhibited magnetic responsiveness. Encapsulation efficiency was 89.75% and effective drug loading was calculated to be 15.25%. The release results in vitro showed that the half release time （ta/2） of cisplatin in cisplatin Solution and Folate-CDDP/HSA MNP was 65 min and 24 h respectively, which indicated that microspheres had an obvious effect of sustained-release. Conclusion： Folate-CDDP/HSA MNPs were prepared successfully. The preparation process and re展开更多
基金This study was funded by RemeGen Co.,Ltd.This work was also supported by the National Natural Science Foundation of China(No.91959205)the Ministry of Science and Technology of China(No.2017YFC1308900,No.2018ZX09201-015)Beijing Municipal Health Commission(No.2020-1-1022)。
文摘Background:Current treatment options for human epidermal growth factor receptor 2(HER2)-overexpressing gastric cancer at third-line have shown limited clinical benefit.Further,there is no specific treatment for HER2 immunohistochemistry(IHC)2+and fluorescence in-situ hybridization-negative patients.Here,we report the efficacy and safety of a novel anti-HER2 antibody RC48 for patients with HER2-overexpressing,advanced gastric or gastroesophageal junction cancer.Methods:Patients with HER2-overexpressing(IHC 2+or 3+),locally advanced or metastatic gastric or gastroesophageal junction cancer who were under at least second-line therapy were eligible and received RC482.5 mg/kg alone every 2 weeks.The primary endpoint was the objective response rate(ORR)assessed by an independent review committee.Secondary endpoints included progressionfree survival(PFS),overall survival(OS),duration of response,time to progression,disease control rate,and safety.Results:Of 179 patients screened,125 were eligible and received RC48 treatment.The ORR was 24.8%(95%confidence interval[CI]:17.5%-33.3%).The median PFS and OS were 4.1 months(95%CI:3.7-4.9 months)and 7.9 months(95%CI:6.7-9.9 months),respectively.The most frequently reported adverse events were decreased white blood cell count(53.6%),asthenia(53.6%),hair loss(53.6%),decreased neutrophil count(52.0%),anemia(49.6%),and increased aspartate aminotransferase level(43.2%).Serious adverse events(SAEs)occurred in 45(36.0%)patients,and RC48-related SAEs were mainly decreased neutrophil count(3.2%).Seven patients had adverse events that led to death were not RC48-related.Conclusions:RC48 showed promising activity with manageable safety,suggesting potential application in patients with HER2-overexpressing,advanced gastric or gastroesophageal junction cancer who have previously received at least two lines of chemotherapy.
基金the National Natural Science Foundation of China,China(Grant No.82073402).
文摘Antibody–drug conjugate(ADC)is typically composed of a monoclonal antibody(mAbs)covalently attached to a cytotoxic drug via a chemical linker.It combines both the advantages of highly specific targeting ability and highly potent killing effect to achieve accurate and efficient elimination of cancer cells,which has become one of the hotspots for the research and development of anticancer drugs.Since the first ADC,Mylotarg®(gemtuzumab ozogamicin),was approved in 2000 by the US Food and Drug Administration(FDA),there have been 14 ADCs received market approval so far worldwide.Moreover,over 100 ADC candidates have been investigated in clinical stages at present.This kind of new anti-cancer drugs,known as“biological missiles”,is leading a new era of targeted cancer therapy.Herein,we conducted a review of the history and general mechanism of action of ADCs,and then briefly discussed the molecular aspects of key components of ADCs and the mechanisms by which these key factors influence the activities of ADCs.Moreover,we also reviewed the approved ADCs and other promising candidates in phase-3 clinical trials and discuss the current challenges and future perspectives for the development of next generations,which provide insights for the research and development of novel cancer therapeutics using ADCs.
基金the National Natural Science Foundation of China(19801033,10171104).
文摘Abstract. Conjugate gradient methods are very important methods for unconstrainedoptimization, especially for large scale problems. In this paper, we propose a new conjugategradient method, in which the technique of nonmonotone line search is used. Under mildassumptions, we prove the global convergence of the method. Some numerical results arealso presented.
基金supported by the National Natural Science Foundation of China(No.61273058)
文摘Accelerated degradation test is a useful approach to predict the product lifetime at the normal use stress level, especially for highly reliable products. Two kinds of the lifetime prediction based on Gamma processes were studied. One was to predict the lifetime of the population from accelerated degradation data, and the other was to predict the lifetime of an individual by taking the accelerated degradation data as prior information. For an extensive application, the Gamma process with a time transformation and random effects was considered. A novel contribution is that a deducing method for determining the relationships between the shape and scale parameters of Gamma processes and accelerated stresses was presented. When predicting the lifetime of an individual, Bayesian inference methods were adopted to improve the prediction accuracy, in which the conjugate prior distribution and the non-conjugate prior distribution of random parameters were studied. The conjugate prior distribution only considers the random effect of the scale parameter while the non-conjugate prior distribution considers the random effects of both the scale and shape parameter. The application and usefulness of the proposed method was demonstrated by the accelerated degradation data of carbon-film resistors.
基金Supported by National High Technology Research and Development Program(863)of China,No.2012AA021001National Natural Science Foundation of China,No.81270554+1 种基金Special Fund for Health Research in the Public Interest of China,No.201302009National Key Specialty Construction of Clinical Projects,No.201354409
文摘AIM: To explore the role and potential mechanism of miR-30 b regulation of autophagy in hepatic ischemiareperfusion injury(IRI).METHODS: An animal model of hepatic IRI was generated in C57BL/6 mice. For in vitro studies, AML12 cells were immersed in mineral oil for 1 h and then cultured in complete Dulbecco's Modified Eagle's Medium(DMEM)/F12 to simulate IRI. Mice and cells were transfected with miR-30 b agomir/mimics or antagomir/inhibitor to examine the effect of miR-30 b on autophagy to promote hepatic IRI. The expression of miR-30 b was measured by real-time polymerase chain reaction. Apoptotic cells were detected by terminal uridine nickend labeling(TUNEL) staining, and cell viability was detected by methylthiazole tetrazolium assay. The expression of light chain 3, autophagy-related gene(Atg)12, Atg5, P62, and caspase-3 were detected by western blotting analysis.RESULTS: miR-30 b levels were significantly downregulated after hepatic IRI, and the numbers of autophagosomes were increased in response to IRI both in vivo and in vitro. These findings demonstrate that low levels of miR-30 b could promote hepatic IRI. Furthermore, we found that miR-30 b interacted with Atg12-Atg5 conjugate by binding to Atg12. Overexpression of miR-30 b diminished Atg12 and Atg12-Atg5 conjugate levels, which promoted autophagy in response to IR. In contrast, downregulation of miR-30 b was associated with increased Atg12-Atg5 conjugate levels and increased autophagy.CONCLUSION: miR-30 b inhibited autophagy to alleviate hepatic ischemia-reperfusion injury via decreasing the Atg12-Atg5 conjugate.
基金partly supportedby National Natural Science Foundation of China(Grant No.41472103)
文摘Recent studies, focused on dihedral angles and intersection processes, have increased understandings of conjugate fault mechanisms. We present new 3-D seismic data and microstructural core analysis in a case study of a large conjugate strike-slip fault system from the intracratonic Tarim Basin, NW China. Within our study area, ＂X＂ type NE and NW trending faults occur within Cambrian- Ordovician carbonates. The dihedral angles of these conjugate faults have narrow ranges, 19~ to 62~ in the Cambrian and 26~ to 51~ in the Ordovician, and their modes are 42~ and 44~ respectively. These data are significantly different from the ~60~ predicted by the Coulomb fracture criterion. It is concluded that： （1） The dihedral angles of the conjugate faults were not controlled by confining pressure, which was low and associated with shallow burial; （2） As dihedral angles were not controlled by pressure they can be used to determine the shortening direction during faulting; （3） Sequential slip may have played an important role in forming conjugate fault intersections; （4） The conjugate fault system of the Tarim basin initiated as rhombic joints; these subsequently developed into sequentially active ＂X＂ type conjugate faults; followed by preferential development of the NW-trending faults; then reactivation of the NE trending faults. This intact rhombic conjugate fault system presents new insights into mechanisms of dihedral angle development, with particular relevance to intracratonic basins.
基金supported by the National Natural Science Foundation of China(Project Nos.51934004,51674158,51574158,and 51474106)the Major Program of Shandong Province Natural Science Foundation(ZR2018ZA0602)+2 种基金the Taishan Scholar Talent Team Support Plan for Advantaged&Unique Discipline Areasthe Science and technology support plan for Youth Innovation of colleges and universities in Shandong Province(2019KJH006)the special funds for Taishan scholar project(TS20190935)。
文摘To study the seepage and deformation characteristics of coal at high temperatures,coal samples from six different regions were selected and subjected to computed tomography(CT)scanning studies.In conjunction with ANSYS software,3 D reconstruction of CT images was used for the establishment of fluidsolid conjugate heat transfer model and coal thermal deformation model based on the microstructures of coal.In addition,the structure of coal was studied in 2 D and 3 D perspectives,followed by the analysis of seepage and deformation characteristics of coal at high temperatures.The results of this study indicated that porosity positively correlated with the fractal dimension,and the connectivity and seepage performances were roughly identical from 2 D and 3 D perspectives.As the porosity increased,the fractal dimension of coal samples became larger and the pore-fracture structures became more complex.As a result,the permeability of coal samples decreased.In the meantime,fluid was fully heated,generating high-temperature water at outlet.However,when the porosity was low,the outlet temperature was very high.The average deformation of coal skeleton with different pore-fracture structures at high temperatures showed a trend of initial increase and subsequent decrease with the increase of porosity and fractal dimension.The maximum deformation of coal skeleton positively correlated with connectivity but negatively correlated with the fractal dimension.
基金Project supported by the National Natural Science Foundation of China (Grant No. 19801033).
文摘The convergence properties of the Fletcher-Reeves method for unconstrained optimization are further studied with the technique of generalized line search. Two conditions are given which guarantee the global convergence of the Fletcher-Reeves method using generalized Wolfe line searches or generalized Arjimo line searches, whereas an example is constructed showing that the conditions cannot be relaxed in certain senses.
基金supported by National Natural Science Foundation of China (Grant No.10871016)
文摘The purpose of this paper is to give a selective survey on recent progress in random metric theory and its applications to conditional risk measures.This paper includes eight sections.Section 1 is a longer introduction,which gives a brief introduction to random metric theory,risk measures and conditional risk measures.Section 2 gives the central framework in random metric theory,topological structures,important examples,the notions of a random conjugate space and the Hahn-Banach theorems for random linear functionals.Section 3 gives several important representation theorems for random conjugate spaces.Section 4 gives characterizations for a complete random normed module to be random reflexive.Section 5 gives hyperplane separation theorems currently available in random locally convex modules.Section 6 gives the theory of random duality with respect to the locally L0-convex topology and in particular a characterization for a locally L0-convex module to be L0-pre-barreled.Section 7 gives some basic results on L0-convex analysis together with some applications to conditional risk measures.Finally,Section 8 is devoted to extensions of conditional convex risk measures,which shows that every representable L∞-type of conditional convex risk measure and every continuous Lp-type of convex conditional risk measure(1 ≤ p < +∞) can be extended to an L∞F(E)-type of σ,λ(L∞F(E),L1F(E))-lower semicontinuous conditional convex risk measure and an LpF(E)-type of T,λ-continuous conditional convex risk measure(1 ≤ p < +∞),respectively.
基金Research partially supported by Chinese NSF grants 19801033,19771047 and 10171104
文摘In this paper we test different conjugate gradient (CG) methods for solving large-scale unconstrained optimization problems. The methods are divided in two groups: the first group includes five basic CG methods and the second five hybrid CG methods. A collection of medium-scale and large-scale test problems are drawn from a standard code of test problems, CUTE. The conjugate gradient methods are ranked according to the numerical results. Some remarks are given.
基金supported by the National Natural Science Foundation of China(Grant Nos.51172192,11272275 and 11002122)the Natural Science Foundation of Hunan Province(Grant No.11JJ4003)the Doctoral Scientific Research Foundation of Xiangtan University(Grant Nos.KZ08022,KZ03013 and KF20140303)
文摘To study the temperature distribution and thermal-stress field in different service stages, a two-dimensional model of a turbine blade with thermal barrier coatings is developed, in which the conjugate heat transfer analysis and the decoupled thermal-stress calculation method are adopted. Based on the simulation results, it is found that a non-uniform distribution of temperature appears in different positions of the blade surface, which has directly impacted on stress field. The maximum temperature with a value of 1030 ℃ occurs at the leading edge. During the steady stage, the maximum stress of thermally grown oxide （TGO） appears in the middle of the suction side, reaching 3.75 GPa. At the end stage of cooling, the maximum compressive stress of TGO with a value of-3.5 GPa occurs at the leading edge. Thus, it can be predicted that during the steady stage the dangerous regions may locate at the suction side, while the leadine edge mav be more Drone to failure on cooling.
基金Subsidized by The Special Funds For Major State Basic Research Projects G1999032803.
文摘A class of regularized conjugate gradient methods is presented for solving the large sparse system of linear equations of which the coefficient matrix is an ill-conditioned symmetric positive definite matrix. The convergence properties of these methods are discussed in depth, and the best possible choices of the parameters involved in the new methods are investigated in detail. Numerical computations show that the new methods are more efficient and robust than both classical relaxation methods and classical conjugate direction methods.
基金Supported by the National Natural Science Foundation of China (No.19801033 and 10171104).
文摘Two Armijo-type line searches are proposed in this paper for nonlinear conjugate gradient methods. Under these line searches, global convergence results are established for several famous conjugate gradient methods, including the Fletcher-Reeves method, the Polak-Ribiere-Polyak method, and the conjugate descent method.
基金supported by a grant 30872999 from the National Natural Science Foundation of Chinaa grant BK2007023 from Jiangsu Province Natural Science Foundation of China
文摘Objective： Nanoparticles are becoming an important method of targeted drug delivery. To evaluate the importance of folate-conjugated human serum albumin （HSA） magnetic nanoparticles （Folate-CDDP/HSA MNP）, we prepared drug-loaded Folate-CDDP/HSA MNPs and characterized their features. Methods： First, folate was conjugated with HSA under the effect of a condensing agent, and the conjugating rate was evaluated by a colorimetric method using 2, 4, 6 - trinitrobenzene sulfonic acid. Second, under N., gas, Fe：~O1 magnetic nanomaterials were prepared and characterized by using transmission electron microscopy （TEM）, SEM-EDS and X-ray diffraction （XRD）. Finally, Folate-CDDP/HSA MNP was prepared by using a solvent evaporation technique. TEM was used to observe particle morphology. The particle size and distribution of the prepared complexes were determined by a Laser particle size analyzer. Drug loading volume and drug release were investigated by a high performance liquid chromatography method （HPLC） in vitro. Results： We successfully prepared folate-conjugated HSA and its conjugating rate was 27.26 μg/mg. Under TEM, Fe2O4 magnetic nanoparticles were highly electron density and had an even size distribution in the range of 10-20 nm. It was confirmed by SEM-EDS and XRD that Fe304 magnetic nanoparticles had been successfully prepared. Under TEM, drug-loaded magnetic nanoparticles were observed, which had a round shape, similar uniform size and smooth surface. Their average size was 79 nm which was determined by laser scattering, and they exhibited magnetic responsiveness. Encapsulation efficiency was 89.75% and effective drug loading was calculated to be 15.25%. The release results in vitro showed that the half release time （ta/2） of cisplatin in cisplatin Solution and Folate-CDDP/HSA MNP was 65 min and 24 h respectively, which indicated that microspheres had an obvious effect of sustained-release. Conclusion： Folate-CDDP/HSA MNPs were prepared successfully. The preparation process and re
