Aqueous humor provides the necessary nutrition for the lens and transports the metabolites in the eye.It was a liquid that can directly reflect the microenvironment in the eye'and it can be easily obtained during ...Aqueous humor provides the necessary nutrition for the lens and transports the metabolites in the eye.It was a liquid that can directly reflect the microenvironment in the eye'and it can be easily obtained during the operation.This review intended to analyze the components of aqueous humor in patients with different types of cataracts'so as to reflect the pathogenesis and development of the disease'evaluate the incidence of postoperative complications and provide reference value for the surgical design of sequential cataract surgery.The aqueous humor components of different types of cataracts showed different degrees of inflammation'oxidative stress and extracellular matrix remodeling.The biomarker of early neuropathy in diabetic cataract was neural cell adhesion molecule-1(NCAM1).Transforming growth factor-β(TGF-β)was the evaluation factor of disease development in patients with pseudoexfoliation syndrome.The relationships between postoperative complications of different types of cataracts and aqueous humor components were as follows:Macular edema after diabetic cataract surgery was associated with tumor necrosis factor-alpha;capsular contraction after high myopic cataract surgery was related to monocyte chemoattractant protein-1(MCP-1)and TGF-β2;Klotho and glutathione S-transferase P 1(GSTP1)were associated with high intraocular pressure after primary open-angle glaucoma complicated by cataract surgery;capsular contraction after retinitis pigmentosa complicated by cataract surgery was associated with matrix metalloproteinases;pro-inflammatory cytokines and fibroblast growth factor 4 in the aqueous humor of congenital cataracts were associated with posterior capsular opacification after surgery.Granulocyte colony stimulating factor 3 and MCP-1 were the main cytokines mediating the pain of the second eye in the binocular sequential cataract surgery short interval(1 wk)'while MCP-1 mediated pain in the long interval(6 wk).The second eye after binocular sequential cataract surgery had a higher level of proinflammatory factors.The components of aqueous humor in patients with different types of cataracts were related to the pathogenesis and postoperative complications of the disease.Monitoring the components of the aqueous humor could help better understand the intraocular microenvironment of different types of cataracts and provide a reference for predicting the development of the disease and implementing relevant targeted therapy.展开更多
For the aim of finding new available functional materials, a series of nitrogen heteroatom 2 β naphthylbenzoxazole molecules were designed based on the experiment and theoretical studies of 2 β naphthylb...For the aim of finding new available functional materials, a series of nitrogen heteroatom 2 β naphthylbenzoxazole molecules were designed based on the experiment and theoretical studies of 2 β naphthylbenzoxazole molecule. Geometry optimization of the 2 β naphthylbenzoxazole was carried out by using Hyperchem Molecular Mechanics plus MM+. The planar molecular structure was obtained. The quantum chemistry calculating method PPP SCF CI, which is specially available to treat electron spectrum, was applied to investigate each novel designed molecules. Their electronic structures were analyzed in detail, it shows that total π electron energy decreased linearly with the number of replaced nitrogen. Single nitrogen atom located in benzoxazole ring or naphthalene ring results in contrary changes of level difference of FMO; multiple nitrogen atoms located in different molecular positions will lead to polarization of extremum in the level difference of FMO; and 5 nitrogen heteroatoms reach the culmination. Considering other electronic structure information, some favorable designed molecules were identified.展开更多
A series of CH2, NH, O, and Se substituted 2,1,3-benzothiadiazote derivatives have been designed and investigated computationally to elucidate their potential as organic light-emitting materials for organic light-emit...A series of CH2, NH, O, and Se substituted 2,1,3-benzothiadiazote derivatives have been designed and investigated computationally to elucidate their potential as organic light-emitting materials for organic light-emitting diodes. Both ab initio Hartree-Foek and hybrid density functional methods are used. It is found that S by CH2, NH, O, and Se makes it possible transport properties of the pristine molecule adjusting the central aromatic ring by replacing to fine-tune the electronic, optical, and charge展开更多
The field-effect transistor is inherently bipolar, having simultaneously electron and hole surface and volume channels and currents. The channels and currents are controlled by one or more externally applied transvers...The field-effect transistor is inherently bipolar, having simultaneously electron and hole surface and volume channels and currents. The channels and currents are controlled by one or more externally applied transverse electric fields. It has been known as the unipolar field-effect transistor for 55-years since Shockley's 1952 invention,because the electron-current theory inevitably neglected the hole current from over-specified internal and boundary conditions, such as the electrical neutrality and the constant hole-electrochemical-potential, resulting in erroneous solutions of the internal and terminal electrical characteristics from the electron channel current alone, which are in gross error when the neglected hole current becomes comparable to the electron current, both in subthreshold and strong inversion. This report presents the general theory, that includes both electron and hole channels and currents. The rectangular ( x, y, z) parallelepiped transistors,uniform in the width direction (z-axis),with one or two MOS gates on thin and thick,and pure and impure base, are used to illustrate the two-dimensional effects and the correct internal and boundary conditions for the electric and the electron and hole electrochemical potentials. Complete analytical equations of the DC current-voltage characteristics of four common MOS transistor structures are derived without over-specification: the 1-gate on semi-infinite-thick impure-base (the traditional bulk transistor), the 1-gate on thin impure-silicon layer over oxide-insulated silicon bulk (SOI) ,the 1-gate on thin impure-silicon layer deposited on insulating glass (SOI TFT), and the 2-gates on thin pure-base (FinFETs).展开更多
Objective To investigate the clinical features and treatment of placenta previa complicated with previous caesarean section. Methods The clinical data of 29 patients with placenta previa complicated with a previous ca...Objective To investigate the clinical features and treatment of placenta previa complicated with previous caesarean section. Methods The clinical data of 29 patients with placenta previa complicated with a previous caesarean section (RCS group) admitted in Peking Union Medical College Hospital during a period from 2003 to 2011 were retrospectively reviewed and compared with those of 243 patients with placenta previa without a previous caesarean section (FCS group) during the same period. Results There was no difference in the mean age (28.9±3.6 vs. 28.1±4.5 years) and the average gravidity (2.35±1.48 vs. 2.21±1.53) between RCS group and FCS group (all P>0.05). The RCS group had more preterm births (24.1% vs. 13.2%), complete placenta previa (55.2% vs. 4.9%), placenta accreta (34.5% vs. 2.5%), more blood loss during caesarean section (1412±602 vs. 648±265 mL), blood transfusion (51.7% vs. 4.9%), disseminated intravascular coagulation (13.8% vs. 2.1%), and obstetric hysterectomy (13.8% vs. 0.8%) than the FCS group (all P<0.05). The preterm infant rate (30.0% vs. 13.0%), neonatal asphyxia rate (10.0% vs. 4.9%), and perinatal mortality rate (6.7% vs. 0.4%) of the RCS group were higher than those of the FCS group (all P<0.05). Conclusions More patients had complete placenta previa and placenta accreta, postpartum hemorrhage, transfusion, uterine packing, obstetric hysterectomy, and perinatal morbidity in the placenta previa patients with previous caesarean section. The patient should be informed of the risk and unnecessary first cesarean sections should be avoided.展开更多
This paper describes the bipolar field-effect transistor (BiFET) and its theory. Analytical solution is ob- tained from partitioning the two-dimensional transistor into two one-dimensional transistors. The analysis ...This paper describes the bipolar field-effect transistor (BiFET) and its theory. Analytical solution is ob- tained from partitioning the two-dimensional transistor into two one-dimensional transistors. The analysis employs the parametric surface-electric-potential and the electrochemical (quasi-Fermi) potential-gradient driving force to compute the current. Output and transfer D. C. current and conductance versus voltage are presented over practi- cal ranges of terminal D. C. voltages and device parameters. Electron and hole surface channel currents are pres- ent simultaneously, a new feature which could provide circuit functions in one physical transistor such as the CMOS inverter and SRAM memory.展开更多
This paper describes the short channel theory of the bipolar field-effect transistor (BiFET) by partitioning the transistor into two sections,the source and drain sections,each can operate as the electron or hole em...This paper describes the short channel theory of the bipolar field-effect transistor (BiFET) by partitioning the transistor into two sections,the source and drain sections,each can operate as the electron or hole emitter or collector under specific combinations of applied terminal voltages. Analytical solution is obtained in the source and drain sections by separating the two-dimensional trap-free Shockley Equations into two one-dimensional equations parametrically coupled via the surface-electric-potential and by using electron current continuity and hole current continuity at the boundary between the emitter and collector sections. Total and electron-hole-channel components of the output and transfer currents and conductances, and the electrical lengths of the two sections are computed and presented in graphs as a function of the D. C. terminal voltages for the model transistor with two identical and connected metal-oxide-silicon-gates (MOS-gates) on a thin pure-silicon base over practical ranges of thicknesses of the silicon base and gate oxide. Deviations of the long physical channel currents and conductances from those of the short electrical channels are reported.展开更多
This paper gives the short channel analytical theory of the bipolar field-effect transistor (BiFET) with the drift and diffusion currents separately computed in the analytical theory. As in the last-month paper whic...This paper gives the short channel analytical theory of the bipolar field-effect transistor (BiFET) with the drift and diffusion currents separately computed in the analytical theory. As in the last-month paper which represented the drift and diffusion current by the single electrochemical (potential-gradient) current, the two-dimensional transistor is partitioned into two sections, the source and drain sections, each can operate as the electron or hole emitter or collector under specific combinations of applied terminal voltages. Analytical solution is then obtained in the source and drain sections by separating the two-dimensional trap-free Shockley Equations into two one-dimensional equations parametrically coupled via the surface-electric-potential and by using electron current continuity and hole current continuity at the boundary between the emitter and collector sections. Total and the drift and diffusion components of the electron-channel and hole-channel currents and output and transfer conductances, and the electrical lengths of the two sections are computed and presented in graphs as a function of the D. C. terminal voltages for the model transistor with two identical and connected metal-oxide-silicon-gates (MOS-gates) on a thin pure-silicon base over practical ranges of thicknesses of the silicon base and gate oxide. Deviations of the two-section short-channel theory from the one-section long-channel theory are described.展开更多
Squeezing properties in the nondegenerate two-photon Jaynes-Cummings model are investigated. The effects of direct selective atomic measurement and the application of the classical field followed by atomic measurement...Squeezing properties in the nondegenerate two-photon Jaynes-Cummings model are investigated. The effects of direct selective atomic measurement and the application of the classical field followed by atomic measurement are analyzed. Different values of the parameters of the classical field are taken into account. It is found that the field squeezing can be enhanced by measurement.展开更多
This paper describes the drift-diffusion theory of the bipolar field-effect transistor (BiFET) with two identical and connected metal-oxide-silicon-gates (MOS-gates) on a thin-pure-base. Analytical solution is obt...This paper describes the drift-diffusion theory of the bipolar field-effect transistor (BiFET) with two identical and connected metal-oxide-silicon-gates (MOS-gates) on a thin-pure-base. Analytical solution is obtained by partitioning the two-dimensional transistor into two one-dimensional problems coupled by the parametric sur- face-electric-potential. Total and component output and transfer currents and conductances versus D. C. voltages from the drift-diffusion theory, and their deviations from the electrochemical (quasi-Fermi) potential-gradient theory,are presented over practical ranges of thicknesses of the silicon base and gate oxide. A substantial contri- bution from the longitudinal gradient of the square of the transverse electric field is shown.展开更多
This paper firstly introduces the structure and working principle of DSP-based parallel system, parallel accelerating board and SHARC DSP chip. Then it pays attention to investigating the system’s programming charact...This paper firstly introduces the structure and working principle of DSP-based parallel system, parallel accelerating board and SHARC DSP chip. Then it pays attention to investigating the system’s programming characteristics, especially the mode of communication, discussing how to design parallel algorithms and presenting a domain-decomposition-based complete multi-grid parallel algorithm with virtual boundary forecast (VBF) to solve a lot of large-scale and complicated heat problems. In the end, Mandelbrot Set and a non-linear heat transfer equation of ceramic/metal composite material are taken as examples to illustrate the implementation of the proposed algorithm. The results showed that the solutions are highly efficient and have linear speedup.展开更多
Platinum group metals(PGMs)usually exhibit promising aerobic catalytic abilities,providing a green and feasible oxidative desulfurization method.However,often,the PGM nanoparticles(NPs)get leached,and the catalysts ar...Platinum group metals(PGMs)usually exhibit promising aerobic catalytic abilities,providing a green and feasible oxidative desulfurization method.However,often,the PGM nanoparticles(NPs)get leached,and the catalysts are deactivated.In this work,Pt NPs with particle sizes of approximately 4–5 nm were encapsulated effectively and uniformly on the surface of vanadium pentoxide(V2O5)nanosheets(with thicknesses of approximately six atomic layers)through strong metal-support interactions.The synthesized catalysts promote catalytic aerobic oxidation reactions,realizing deep desulfurization(99.1%,<5μg g^(–1))under atmospheric pressure and 110℃reaction temperature.Remarkable degrees of sulfur removal could be achieved for oils with different initial S-concentrations and substrates.Additionally,the as-prepared catalysts could be recycled for reuse at least seven times.展开更多
We propose the supereonneetion formalism to construct the off-shell BRST-VSUSY superalgebra for D = 4 BF theories. The method is based on the natural introduction of physical fields as well as auxiliary fields via sup...We propose the supereonneetion formalism to construct the off-shell BRST-VSUSY superalgebra for D = 4 BF theories. The method is based on the natural introduction of physical fields as well as auxiliary fields via supereon- neetions and their associated supereurvatures defined on a superspaee. We also give a prescription to build the off-shell BRST-VSUSY exact quantum action.展开更多
An OpenMP approach was proposed to parallelize the sequential molecular dynamics(MD) code on shared memory machines. When a code is converted from the sequential form to the parallel form, data dependence is a main pr...An OpenMP approach was proposed to parallelize the sequential molecular dynamics(MD) code on shared memory machines. When a code is converted from the sequential form to the parallel form, data dependence is a main problem. A traditional sequential molecular dynamics code is anatomized to find the data dependence segments in it, and the two different methods, i.e., recover method and backward mapping method were used to eliminate those data dependencies in order to realize the parallelization of this sequential MD code. The performance of the parallelized MD code was analyzed by using some performance analysis tools. The results of the test show that the computing size of this code increases sharply form 1 million atoms before parallelization to 20 million atoms after parallelization, and the wall clock during computing is reduced largely. Some hot-spots in this code are found and optimized by improved algorithm. The efficiency of parallel computing is 30% higher than that of before, and the calculation time is saved and larger scale calculation problems are solved.展开更多
AIM:To perform a review of patients with colorectal cancer to a community hospital and to compare the risk-adjusted survival between patients managed in general surgical units versus a colorectal unit. METHODS:The stu...AIM:To perform a review of patients with colorectal cancer to a community hospital and to compare the risk-adjusted survival between patients managed in general surgical units versus a colorectal unit. METHODS:The study evaluated all patients with colorectal cancer referred to either general surgical units or a colorectal unit from 1/1996 to 6/2001.These results were compared to a historical control group treated within general surgical units at the same hospital from 1/1989 to 12/1994.A Kaplan- Meier survival analysis compared the overall survivals (all- cause mortality) between the groups.A Cox proportional hazards model was used to determine the influence of a number of independent variables on survival.These variables included age,ASA score,disease stage,emergency surgery, adjuvant chemotherapy and/or radiotherapy,disease location,and surgical unit. RESULTS:There were 974 patients involved in this study. There were no significant differences in the demographic details for thethree groups.Patients in the colorectal group were more likely to have rectal cancer and Stage Ⅰ cancers, and less likely to have Stage Ⅱ cancers.Patients treated in the colorectal group had a significantly higher overall 5-year survival when compared with the general surgical group and the historical control group (56 % versus 45 % and 40 % respectively,P<0.01).Survival regression analysis identified age,ASA score,disease stage,adjuvant chemotherapy,and treatment in a colorectal unit (Hazards ratio:0.67;95 % CI:0.53 to 0.84,P =0.0005),as significant independent predictors of survival. CONCLUSION:The results suggest that there may be a survival advantage for patients with colon and rectal cancers being treated within a specialist colorectal surgical unit.展开更多
Objective. To determine whether malariotherapy (an old therapy for treatment of neurosyphilis) improves some clinical and laboratory parameters of HIV positive patients without iatrogenic compl...Objective. To determine whether malariotherapy (an old therapy for treatment of neurosyphilis) improves some clinical and laboratory parameters of HIV positive patients without iatrogenic complications. Methods. Total 8 asymptomatic HIV 1 positive subjects whose CD4 cell counts were over 250×10 6 cells/L were selected for the phase 1 studies of malariotherapy and were intravenously injected Plasmodia vivax to induce artificial malaria. Malaria was terminated with chloroquine after 10~20 malarial fever episodes. Cell bound CD4 levels were measured by APAAP (a solid phase enzyme essay) and levels of neopterin (NPT), beta 2 microglobulin (B2M), soluble tumor necrosis factor receptor 2(sTNF RII), interleukin 2(IL 2) and HIV P24 antigen were measured by ELISA. Patients were followed up to 24~30 months. Results.CD4 levels increased in 5, NPT decreased in 7 of 8 patients; IL 2 increased in 5 of 6 patients after malariotherapy. The total trends of B2M and sTNF RII basically remained stable. HIV P24 antigen remained undetectable in 6, remained detectably low level in 1 and experienced increase in 1 of 8 patients after malariotherapy. No any severe complications occurred in all 8 patients. Conclusions. The results indicate that malariotherapy basically is safe for HIV infection and it seems that the therapy improves some immunological parameters of HIV patients.展开更多
Objective: To study the influences of different time intervals between loop electrosurgical excision (LEEP) and abdominal hysterectomy or radical hysterectomy on postoperative complications. Methods: Sixty-eight p...Objective: To study the influences of different time intervals between loop electrosurgical excision (LEEP) and abdominal hysterectomy or radical hysterectomy on postoperative complications. Methods: Sixty-eight patients, who received subsequent abdominal hysterectomy or radical hysterectomy after LEEP due to C1N III and cervical cancer (IA1, IA2 and IB1), were included in the present study. The hospital and clinic records of these patients were reviewed. The patients were divided into three groups according to the time intervals between LEEP and hysterectomy or radical hysterectomy: group l(within 48 h), group 2 (between 48 h to 6 weeks), and group 3(〉 6 weeks ).Results: General characteristics of patients, including the mean age, delivery history, BMI, menopausal status, clinical stage and HPV infection, were comparable between patients of different groups. There were no significant differences in the mean transfusion amount, posthysterectomy hospital stay or operation time between different groups. The frequencies and spectrum of complications were not significantly affected by the time interval between LEEP and hysterectomy or radical hysterectomy. Conclusion: It is concluded that whenever the LEEP is done, the operation including hysterectomy or radical hysterectomy can be conducted at any time as it is necessary for the patients.展开更多
Two-photon resonant nondegenerate four-wave mixing (NFWM) with the addition of a coupling field in Ba atomic vapour has been studied. We find that coherence of the atomic level transitions leads to suppression of th...Two-photon resonant nondegenerate four-wave mixing (NFWM) with the addition of a coupling field in Ba atomic vapour has been studied. We find that coherence of the atomic level transitions leads to suppression of the NFWM signal, giving rise to a dip with a linewidth that is linearly proportional to the intensity of the coupling field.展开更多
1 Introduction Transcatheter aortic valve implantation (TAVI) constitutes an established treatment in inoperable or high perioperative risk patients with severe aortic stenosis, demonstrating similar mortality rates...1 Introduction Transcatheter aortic valve implantation (TAVI) constitutes an established treatment in inoperable or high perioperative risk patients with severe aortic stenosis, demonstrating similar mortality rates (at 30 days and 1 year) with surgical aortic valve replacement (SAVR). Various complications have been reported during TAVI, weeks or months post procedure. The most frequent causes of transcatheter heart valve (THV) failure are paravalvular regurgitation, infective endocarditis (IE), thrombosis and late valve Migration.展开更多
This article refers to the study on the performance of mesoporous silica used as the catalyst for oxidative desulfurization reactions. The test results revealed that under mild reaction conditions using tert-butyl hyd...This article refers to the study on the performance of mesoporous silica used as the catalyst for oxidative desulfurization reactions. The test results revealed that under mild reaction conditions using tert-butyl hydroperoxide as the oxidizing agent the content of dibenzothiophene(DBT) contained in oil samples could be reduced from 5000 ppm to less than 5 ppm. Furthermore,the mesoporous silica material can be easily regenerated and recycled.展开更多
文摘Aqueous humor provides the necessary nutrition for the lens and transports the metabolites in the eye.It was a liquid that can directly reflect the microenvironment in the eye'and it can be easily obtained during the operation.This review intended to analyze the components of aqueous humor in patients with different types of cataracts'so as to reflect the pathogenesis and development of the disease'evaluate the incidence of postoperative complications and provide reference value for the surgical design of sequential cataract surgery.The aqueous humor components of different types of cataracts showed different degrees of inflammation'oxidative stress and extracellular matrix remodeling.The biomarker of early neuropathy in diabetic cataract was neural cell adhesion molecule-1(NCAM1).Transforming growth factor-β(TGF-β)was the evaluation factor of disease development in patients with pseudoexfoliation syndrome.The relationships between postoperative complications of different types of cataracts and aqueous humor components were as follows:Macular edema after diabetic cataract surgery was associated with tumor necrosis factor-alpha;capsular contraction after high myopic cataract surgery was related to monocyte chemoattractant protein-1(MCP-1)and TGF-β2;Klotho and glutathione S-transferase P 1(GSTP1)were associated with high intraocular pressure after primary open-angle glaucoma complicated by cataract surgery;capsular contraction after retinitis pigmentosa complicated by cataract surgery was associated with matrix metalloproteinases;pro-inflammatory cytokines and fibroblast growth factor 4 in the aqueous humor of congenital cataracts were associated with posterior capsular opacification after surgery.Granulocyte colony stimulating factor 3 and MCP-1 were the main cytokines mediating the pain of the second eye in the binocular sequential cataract surgery short interval(1 wk)'while MCP-1 mediated pain in the long interval(6 wk).The second eye after binocular sequential cataract surgery had a higher level of proinflammatory factors.The components of aqueous humor in patients with different types of cataracts were related to the pathogenesis and postoperative complications of the disease.Monitoring the components of the aqueous humor could help better understand the intraocular microenvironment of different types of cataracts and provide a reference for predicting the development of the disease and implementing relevant targeted therapy.
文摘For the aim of finding new available functional materials, a series of nitrogen heteroatom 2 β naphthylbenzoxazole molecules were designed based on the experiment and theoretical studies of 2 β naphthylbenzoxazole molecule. Geometry optimization of the 2 β naphthylbenzoxazole was carried out by using Hyperchem Molecular Mechanics plus MM+. The planar molecular structure was obtained. The quantum chemistry calculating method PPP SCF CI, which is specially available to treat electron spectrum, was applied to investigate each novel designed molecules. Their electronic structures were analyzed in detail, it shows that total π electron energy decreased linearly with the number of replaced nitrogen. Single nitrogen atom located in benzoxazole ring or naphthalene ring results in contrary changes of level difference of FMO; multiple nitrogen atoms located in different molecular positions will lead to polarization of extremum in the level difference of FMO; and 5 nitrogen heteroatoms reach the culmination. Considering other electronic structure information, some favorable designed molecules were identified.
文摘A series of CH2, NH, O, and Se substituted 2,1,3-benzothiadiazote derivatives have been designed and investigated computationally to elucidate their potential as organic light-emitting materials for organic light-emitting diodes. Both ab initio Hartree-Foek and hybrid density functional methods are used. It is found that S by CH2, NH, O, and Se makes it possible transport properties of the pristine molecule adjusting the central aromatic ring by replacing to fine-tune the electronic, optical, and charge
文摘The field-effect transistor is inherently bipolar, having simultaneously electron and hole surface and volume channels and currents. The channels and currents are controlled by one or more externally applied transverse electric fields. It has been known as the unipolar field-effect transistor for 55-years since Shockley's 1952 invention,because the electron-current theory inevitably neglected the hole current from over-specified internal and boundary conditions, such as the electrical neutrality and the constant hole-electrochemical-potential, resulting in erroneous solutions of the internal and terminal electrical characteristics from the electron channel current alone, which are in gross error when the neglected hole current becomes comparable to the electron current, both in subthreshold and strong inversion. This report presents the general theory, that includes both electron and hole channels and currents. The rectangular ( x, y, z) parallelepiped transistors,uniform in the width direction (z-axis),with one or two MOS gates on thin and thick,and pure and impure base, are used to illustrate the two-dimensional effects and the correct internal and boundary conditions for the electric and the electron and hole electrochemical potentials. Complete analytical equations of the DC current-voltage characteristics of four common MOS transistor structures are derived without over-specification: the 1-gate on semi-infinite-thick impure-base (the traditional bulk transistor), the 1-gate on thin impure-silicon layer over oxide-insulated silicon bulk (SOI) ,the 1-gate on thin impure-silicon layer deposited on insulating glass (SOI TFT), and the 2-gates on thin pure-base (FinFETs).
基金Supported by Beijing Clinical Study(Z111107058811025)Beijing Government Excellent Person Sponsor Program
文摘Objective To investigate the clinical features and treatment of placenta previa complicated with previous caesarean section. Methods The clinical data of 29 patients with placenta previa complicated with a previous caesarean section (RCS group) admitted in Peking Union Medical College Hospital during a period from 2003 to 2011 were retrospectively reviewed and compared with those of 243 patients with placenta previa without a previous caesarean section (FCS group) during the same period. Results There was no difference in the mean age (28.9±3.6 vs. 28.1±4.5 years) and the average gravidity (2.35±1.48 vs. 2.21±1.53) between RCS group and FCS group (all P>0.05). The RCS group had more preterm births (24.1% vs. 13.2%), complete placenta previa (55.2% vs. 4.9%), placenta accreta (34.5% vs. 2.5%), more blood loss during caesarean section (1412±602 vs. 648±265 mL), blood transfusion (51.7% vs. 4.9%), disseminated intravascular coagulation (13.8% vs. 2.1%), and obstetric hysterectomy (13.8% vs. 0.8%) than the FCS group (all P<0.05). The preterm infant rate (30.0% vs. 13.0%), neonatal asphyxia rate (10.0% vs. 4.9%), and perinatal mortality rate (6.7% vs. 0.4%) of the RCS group were higher than those of the FCS group (all P<0.05). Conclusions More patients had complete placenta previa and placenta accreta, postpartum hemorrhage, transfusion, uterine packing, obstetric hysterectomy, and perinatal morbidity in the placenta previa patients with previous caesarean section. The patient should be informed of the risk and unnecessary first cesarean sections should be avoided.
文摘This paper describes the bipolar field-effect transistor (BiFET) and its theory. Analytical solution is ob- tained from partitioning the two-dimensional transistor into two one-dimensional transistors. The analysis employs the parametric surface-electric-potential and the electrochemical (quasi-Fermi) potential-gradient driving force to compute the current. Output and transfer D. C. current and conductance versus voltage are presented over practi- cal ranges of terminal D. C. voltages and device parameters. Electron and hole surface channel currents are pres- ent simultaneously, a new feature which could provide circuit functions in one physical transistor such as the CMOS inverter and SRAM memory.
文摘This paper describes the short channel theory of the bipolar field-effect transistor (BiFET) by partitioning the transistor into two sections,the source and drain sections,each can operate as the electron or hole emitter or collector under specific combinations of applied terminal voltages. Analytical solution is obtained in the source and drain sections by separating the two-dimensional trap-free Shockley Equations into two one-dimensional equations parametrically coupled via the surface-electric-potential and by using electron current continuity and hole current continuity at the boundary between the emitter and collector sections. Total and electron-hole-channel components of the output and transfer currents and conductances, and the electrical lengths of the two sections are computed and presented in graphs as a function of the D. C. terminal voltages for the model transistor with two identical and connected metal-oxide-silicon-gates (MOS-gates) on a thin pure-silicon base over practical ranges of thicknesses of the silicon base and gate oxide. Deviations of the long physical channel currents and conductances from those of the short electrical channels are reported.
文摘This paper gives the short channel analytical theory of the bipolar field-effect transistor (BiFET) with the drift and diffusion currents separately computed in the analytical theory. As in the last-month paper which represented the drift and diffusion current by the single electrochemical (potential-gradient) current, the two-dimensional transistor is partitioned into two sections, the source and drain sections, each can operate as the electron or hole emitter or collector under specific combinations of applied terminal voltages. Analytical solution is then obtained in the source and drain sections by separating the two-dimensional trap-free Shockley Equations into two one-dimensional equations parametrically coupled via the surface-electric-potential and by using electron current continuity and hole current continuity at the boundary between the emitter and collector sections. Total and the drift and diffusion components of the electron-channel and hole-channel currents and output and transfer conductances, and the electrical lengths of the two sections are computed and presented in graphs as a function of the D. C. terminal voltages for the model transistor with two identical and connected metal-oxide-silicon-gates (MOS-gates) on a thin pure-silicon base over practical ranges of thicknesses of the silicon base and gate oxide. Deviations of the two-section short-channel theory from the one-section long-channel theory are described.
文摘Squeezing properties in the nondegenerate two-photon Jaynes-Cummings model are investigated. The effects of direct selective atomic measurement and the application of the classical field followed by atomic measurement are analyzed. Different values of the parameters of the classical field are taken into account. It is found that the field squeezing can be enhanced by measurement.
文摘This paper describes the drift-diffusion theory of the bipolar field-effect transistor (BiFET) with two identical and connected metal-oxide-silicon-gates (MOS-gates) on a thin-pure-base. Analytical solution is obtained by partitioning the two-dimensional transistor into two one-dimensional problems coupled by the parametric sur- face-electric-potential. Total and component output and transfer currents and conductances versus D. C. voltages from the drift-diffusion theory, and their deviations from the electrochemical (quasi-Fermi) potential-gradient theory,are presented over practical ranges of thicknesses of the silicon base and gate oxide. A substantial contri- bution from the longitudinal gradient of the square of the transverse electric field is shown.
基金Project (No. 60173046) supported by the National Natural ScienceFoundation of China
文摘This paper firstly introduces the structure and working principle of DSP-based parallel system, parallel accelerating board and SHARC DSP chip. Then it pays attention to investigating the system’s programming characteristics, especially the mode of communication, discussing how to design parallel algorithms and presenting a domain-decomposition-based complete multi-grid parallel algorithm with virtual boundary forecast (VBF) to solve a lot of large-scale and complicated heat problems. In the end, Mandelbrot Set and a non-linear heat transfer equation of ceramic/metal composite material are taken as examples to illustrate the implementation of the proposed algorithm. The results showed that the solutions are highly efficient and have linear speedup.
文摘Platinum group metals(PGMs)usually exhibit promising aerobic catalytic abilities,providing a green and feasible oxidative desulfurization method.However,often,the PGM nanoparticles(NPs)get leached,and the catalysts are deactivated.In this work,Pt NPs with particle sizes of approximately 4–5 nm were encapsulated effectively and uniformly on the surface of vanadium pentoxide(V2O5)nanosheets(with thicknesses of approximately six atomic layers)through strong metal-support interactions.The synthesized catalysts promote catalytic aerobic oxidation reactions,realizing deep desulfurization(99.1%,<5μg g^(–1))under atmospheric pressure and 110℃reaction temperature.Remarkable degrees of sulfur removal could be achieved for oils with different initial S-concentrations and substrates.Additionally,the as-prepared catalysts could be recycled for reuse at least seven times.
基金Acknowledgment M. Tahiri would like to thank the Alexander von Humboldt Stiftung for support and Prof. W. Rfihl (Department of Physics, Kaiserslautern University of Technology) for hospitality.
文摘We propose the supereonneetion formalism to construct the off-shell BRST-VSUSY superalgebra for D = 4 BF theories. The method is based on the natural introduction of physical fields as well as auxiliary fields via supereon- neetions and their associated supereurvatures defined on a superspaee. We also give a prescription to build the off-shell BRST-VSUSY exact quantum action.
基金Project (50371026) supported by the National Natural Science Foundation of China
文摘An OpenMP approach was proposed to parallelize the sequential molecular dynamics(MD) code on shared memory machines. When a code is converted from the sequential form to the parallel form, data dependence is a main problem. A traditional sequential molecular dynamics code is anatomized to find the data dependence segments in it, and the two different methods, i.e., recover method and backward mapping method were used to eliminate those data dependencies in order to realize the parallelization of this sequential MD code. The performance of the parallelized MD code was analyzed by using some performance analysis tools. The results of the test show that the computing size of this code increases sharply form 1 million atoms before parallelization to 20 million atoms after parallelization, and the wall clock during computing is reduced largely. Some hot-spots in this code are found and optimized by improved algorithm. The efficiency of parallel computing is 30% higher than that of before, and the calculation time is saved and larger scale calculation problems are solved.
文摘AIM:To perform a review of patients with colorectal cancer to a community hospital and to compare the risk-adjusted survival between patients managed in general surgical units versus a colorectal unit. METHODS:The study evaluated all patients with colorectal cancer referred to either general surgical units or a colorectal unit from 1/1996 to 6/2001.These results were compared to a historical control group treated within general surgical units at the same hospital from 1/1989 to 12/1994.A Kaplan- Meier survival analysis compared the overall survivals (all- cause mortality) between the groups.A Cox proportional hazards model was used to determine the influence of a number of independent variables on survival.These variables included age,ASA score,disease stage,emergency surgery, adjuvant chemotherapy and/or radiotherapy,disease location,and surgical unit. RESULTS:There were 974 patients involved in this study. There were no significant differences in the demographic details for thethree groups.Patients in the colorectal group were more likely to have rectal cancer and Stage Ⅰ cancers, and less likely to have Stage Ⅱ cancers.Patients treated in the colorectal group had a significantly higher overall 5-year survival when compared with the general surgical group and the historical control group (56 % versus 45 % and 40 % respectively,P<0.01).Survival regression analysis identified age,ASA score,disease stage,adjuvant chemotherapy,and treatment in a colorectal unit (Hazards ratio:0.67;95 % CI:0.53 to 0.84,P =0.0005),as significant independent predictors of survival. CONCLUSION:The results suggest that there may be a survival advantage for patients with colon and rectal cancers being treated within a specialist colorectal surgical unit.
文摘Objective. To determine whether malariotherapy (an old therapy for treatment of neurosyphilis) improves some clinical and laboratory parameters of HIV positive patients without iatrogenic complications. Methods. Total 8 asymptomatic HIV 1 positive subjects whose CD4 cell counts were over 250×10 6 cells/L were selected for the phase 1 studies of malariotherapy and were intravenously injected Plasmodia vivax to induce artificial malaria. Malaria was terminated with chloroquine after 10~20 malarial fever episodes. Cell bound CD4 levels were measured by APAAP (a solid phase enzyme essay) and levels of neopterin (NPT), beta 2 microglobulin (B2M), soluble tumor necrosis factor receptor 2(sTNF RII), interleukin 2(IL 2) and HIV P24 antigen were measured by ELISA. Patients were followed up to 24~30 months. Results.CD4 levels increased in 5, NPT decreased in 7 of 8 patients; IL 2 increased in 5 of 6 patients after malariotherapy. The total trends of B2M and sTNF RII basically remained stable. HIV P24 antigen remained undetectable in 6, remained detectably low level in 1 and experienced increase in 1 of 8 patients after malariotherapy. No any severe complications occurred in all 8 patients. Conclusions. The results indicate that malariotherapy basically is safe for HIV infection and it seems that the therapy improves some immunological parameters of HIV patients.
文摘Objective: To study the influences of different time intervals between loop electrosurgical excision (LEEP) and abdominal hysterectomy or radical hysterectomy on postoperative complications. Methods: Sixty-eight patients, who received subsequent abdominal hysterectomy or radical hysterectomy after LEEP due to C1N III and cervical cancer (IA1, IA2 and IB1), were included in the present study. The hospital and clinic records of these patients were reviewed. The patients were divided into three groups according to the time intervals between LEEP and hysterectomy or radical hysterectomy: group l(within 48 h), group 2 (between 48 h to 6 weeks), and group 3(〉 6 weeks ).Results: General characteristics of patients, including the mean age, delivery history, BMI, menopausal status, clinical stage and HPV infection, were comparable between patients of different groups. There were no significant differences in the mean transfusion amount, posthysterectomy hospital stay or operation time between different groups. The frequencies and spectrum of complications were not significantly affected by the time interval between LEEP and hysterectomy or radical hysterectomy. Conclusion: It is concluded that whenever the LEEP is done, the operation including hysterectomy or radical hysterectomy can be conducted at any time as it is necessary for the patients.
基金Project supported by the National Natural Science foundation of China (Grant Nos 10174096 and 10374113) and the National Program for Basic Research in China (Grant No 001CB309301).
文摘Two-photon resonant nondegenerate four-wave mixing (NFWM) with the addition of a coupling field in Ba atomic vapour has been studied. We find that coherence of the atomic level transitions leads to suppression of the NFWM signal, giving rise to a dip with a linewidth that is linearly proportional to the intensity of the coupling field.
文摘1 Introduction Transcatheter aortic valve implantation (TAVI) constitutes an established treatment in inoperable or high perioperative risk patients with severe aortic stenosis, demonstrating similar mortality rates (at 30 days and 1 year) with surgical aortic valve replacement (SAVR). Various complications have been reported during TAVI, weeks or months post procedure. The most frequent causes of transcatheter heart valve (THV) failure are paravalvular regurgitation, infective endocarditis (IE), thrombosis and late valve Migration.
文摘This article refers to the study on the performance of mesoporous silica used as the catalyst for oxidative desulfurization reactions. The test results revealed that under mild reaction conditions using tert-butyl hydroperoxide as the oxidizing agent the content of dibenzothiophene(DBT) contained in oil samples could be reduced from 5000 ppm to less than 5 ppm. Furthermore,the mesoporous silica material can be easily regenerated and recycled.