The paper discusses SL learners' lexical competence from O'Connor's Five Steps of Vocabulary Acquisition Theory, Collins & Loftus's Semantic Network Theory and Fay & Cutler's Mental Lexicon Theory. From the dis...The paper discusses SL learners' lexical competence from O'Connor's Five Steps of Vocabulary Acquisition Theory, Collins & Loftus's Semantic Network Theory and Fay & Cutler's Mental Lexicon Theory. From the discussion, the author finds that second language learners' lexical competence includes the following aspects: the ability to recall the words which are similar to the target words in spelling and pronunciation; the ability to recall the synonyms of the target words; the ability to recall the antonyms of the target words; and the ability to recall the related words which come together with the target words in a context. Meanwhile it advances some strategies to develop the corresponding competence.展开更多
Functionally graded Al/B_4C, Al/Si C, Al/Al_2O_3 and Al/TiB_2 composites with constant 12%(mass fraction) of reinforcement were fabricated by centrifugal casting and hollow cylindrical components were obtained. Micros...Functionally graded Al/B_4C, Al/Si C, Al/Al_2O_3 and Al/TiB_2 composites with constant 12%(mass fraction) of reinforcement were fabricated by centrifugal casting and hollow cylindrical components were obtained. Microstructural characteristics were investigated at outer surface of all composites and segregation of reinforcement particles was observed. Graded property of the composites with different reinforcements was investigated through hardness and tensile measurements. Results revealed that the outer peripheries of all composites exhibit higher hardness except in Al/B_4C composite and the outer zones of all composites show higher tensile strength. Abrasive wear test was conducted on the outer peripheries of all composites and Al/TiB_2 composite exhibits less wear rate.展开更多
Heart failure (HF) with preserved ejection fraction (HFpEF) is the most common form of HF in older adults, and is increasing in preva- lence as the population ages. Furthermore, HFpEF is increasing out of proporti...Heart failure (HF) with preserved ejection fraction (HFpEF) is the most common form of HF in older adults, and is increasing in preva- lence as the population ages. Furthermore, HFpEF is increasing out of proportion to HF with reduced EF (HFrEF), and its prognosis is worsening while that of HFrEF is improving. Despite the importance of HFpEF, our understanding of its pathophysiology is incomplete, and optimal treatment remains largely undefined. A cardinal feature of HFpEF is reduced exercise tolerance, which correlates with symptoms as well as reduced quality of life. The traditional concepts of exercise limitations have focused on central dysfimction related to poor cardiac pump function. However, the mechanisms are not exclusive to the heart and lungs, and the understanding of the pathophysiology of this dis- ease has evolved. Substantial attention has focused on defining the central versus peripheral mechanisms underlying the reduced functional capacity and exercise tolerance among patients with HF. In fact, physical training can improve exercise tolerance via peripheral adaptive mechanisms even in the absence of favorable central hemodynamic function. In addition, the drug trials performed to date in HFpEF that have focused on influencing cardiovascular function have not improved exercise capacity. This suggests that peripheral limitations may play a significant role in HF limiting exercise tolerance, a hallmark feature of HFpEF.展开更多
Stiffening-ribbed-hollow-pipe cast-in place reinforced concrete girderless floor is a new-style hollow girderless floor system. Model experimental researches of simply-supported floor and four-corners bearing floor ha...Stiffening-ribbed-hollow-pipe cast-in place reinforced concrete girderless floor is a new-style hollow girderless floor system. Model experimental researches of simply-supported floor and four-corners bearing floor have been done on this new kind of floor system in this paper. The experiment results show that the floor system has good mechanical property such as high bearing capacity, big rigidity and good tensility. A theoretical method is presented in this paper that the stiffening-ribbed-hollow-pipe girderless floor can be analyzed by being converted equivalently to orthotropic solid slab. It is indicated that the method is correct and reasonable according to the contrast between theoretical calculated results and experimental measured results. The theoretical results coincide with the measured results well.展开更多
Background: Recent data suggest that beta-blockers can be beneficial in patients with chronic heart failure (CHF). Atrial fibrillation (AF) is present in a significant number of patients with CHF and is associateing w...Background: Recent data suggest that beta-blockers can be beneficial in patients with chronic heart failure (CHF). Atrial fibrillation (AF) is present in a significant number of patients with CHF and is associateing with significant morbidity and increasing mortality rates. Thus it is necessary to establish therapy to improve the poor prognosis in this high-risk population, but a specific benefit of beta-blockers to the subset with concomitant AF and CHF has been little demonstrated. Objective: To examine the effects of Bisoprolol (6 months treatment) on the ventricular function and hemodynamics in patients with AF and CHF. Methods: 84 patients with stable CHF (NYHA≤Ⅲ class) and AF were assigned to Treated Group( n = 37) or Control group Ⅰ ( n = 22, 24-hour heart mean rate < 70/min) or Control Group Ⅱ ( n = 25, 24-hour heart mean rate ≥ 70/min) . All patients were given the basic therapy for CHF, and Treated Group received Bisopolol. Clinical and echocardiographic variables were measured in 3 groups at baseline and after 6 months, and the results were compared . Results: After 6 months of treatment with Bisoprolol, left ventricular ejection fraction (LVEF) and NYHA class had significandy improved (P < 0.05), and a trend towards a reduction in combined end point of death or CHF hospitalization was also observed (P < 0.20) in Treated Group; The increase of LVEF in Treated Group were associated with a reduction in mitral regurgitation degree and left atrial volume; The heart rate in mean 24-hour and at peak exercise decreased in Treated Group, but were similar to that in Control Group Ⅰ. Conclusion: 6 months of Bisoprolol therapy resulted in an improvement in the NYHA class and LVEF, and also showed a trend towards a reduction in hospitalization or death. The beneficial effects of Bisoprolol on patients with AF and CHF may be partly mediated by improvement of ventricular diastolic function.展开更多
Good psychological quality is an integral part of the overall quality of the contemporary college students, which is also an important foundation for their healthy growth and success. However, according to the investi...Good psychological quality is an integral part of the overall quality of the contemporary college students, which is also an important foundation for their healthy growth and success. However, according to the investigation, in reality, many college students have various degrees of psychological problems, seriously affecting their normal learning and living. This article makes an in-depth discussion based on the analysis of contemporary college students' psychological quality system; in order to strengthen the mental health education and improve the students' adaptability.展开更多
Motion sickness is one of the main reasons why travelling by sea becomes a bad memory for a number of people, mainly due to a nauseating symptom. The aim of this paper is to characterize a condition called seasickness...Motion sickness is one of the main reasons why travelling by sea becomes a bad memory for a number of people, mainly due to a nauseating symptom. The aim of this paper is to characterize a condition called seasickness that has affected many people from a mathematical and psychological point of view. Based on the mathematical characterization, an existing model will be reviewed and described. In the psychological aspects, a statistical study of two hundred and thirteen people was performed in order to provide a comprehensive view of the different psychological factors affecting the passengers. Motion sickness also impacts onboard safety, as it reduces the effectiveness and the operating capability of the crew when responding to hazardous situations.展开更多
It is to conduct the teaching exploration for the situational sports model's implementation in sports teaching. It is indicated that the implementation of the situational teaching is good to improve the students' in...It is to conduct the teaching exploration for the situational sports model's implementation in sports teaching. It is indicated that the implementation of the situational teaching is good to improve the students' initiative and interest for study; good for the students' participation; good to improve students' initiative, sports ability and sports level; good to promote students to have healthy physical and psychological development; good to optimize the teaching process and activate the class atmosphere; and also good to promote students' social development factor. It is an ideal teaching concept and teaching model.展开更多
How to find more effective way to stabilize the borehole wall in the fault gouge section is the key technical challenge to control the stability of the borehole wall in the Wenchuan fault gouge section during the proc...How to find more effective way to stabilize the borehole wall in the fault gouge section is the key technical challenge to control the stability of the borehole wall in the Wenchuan fault gouge section during the process of core drilling. Here we try to describe the characters of deep fault gouge in fracture zones from the undisturbed fault gouge samples which are obtained during the core drilling. The X- Ray Diffraction (XRD), X-Ray Fluorescence (XRF) and Scanning Electron Microscope (SEM) provided the detailed information of the fault gouge's microscopic characteristics on the density, moisture content, expansibility, dispersity, permeability, tensile strength and other main physical-mechanical properties. Based on these systematic experimental studies above and analysis of the fault gouge instability mechanism, a new technical procedure to stabilize the borehole wall is proposed -- a low water and a low loss low permeability drilling fluid system that consists of 4% day + 0.5% CMC-HV + 2% S-1 + 3%sulfonated asphalt + 1% SMC + 0.5% X-1 + 0-5% T type lubricant + barite for core drilling in fault gouge sections.展开更多
Since China's reform and accession to the world trade organization (WTO), the international labor division, cooperation, and communication of production have been a direction of the global productivity development....Since China's reform and accession to the world trade organization (WTO), the international labor division, cooperation, and communication of production have been a direction of the global productivity development. The expansion of the world trade organization and the growth of multinational corporations have promoted China's market economy to head for internationalization; the exchanges of all countries' science and technology, culture, and education have become increasingly frequent and beyond the borders very early, so opening-up has become a world trend. China is playing an important role in this historical process. In this situation, the importance of language translation is increasing day by day, and an unprecedented prosperous situation has especially appeared to the interpretation. In order to accord with this new historical situation, many colleges and universities have set up language translation program and have offered interpretation course. To promote the economic development of China and train more senior interpreters, the studies of interpretation teaching and the improvement of interpretation teaching quality have been particularly important. In this paper, the relationship among memory, note-taking, and psychological factors are analyzed.展开更多
After several years of intense study, the most urgent problem those college students must face is employment, what' s more, with the sustaining development of China' s economy and the accelerating pace of social pro...After several years of intense study, the most urgent problem those college students must face is employment, what' s more, with the sustaining development of China' s economy and the accelerating pace of social progress, the society shows much more need for the comprehensiveness and adaptation ability of talents. However, under the influence of long-term examination-oriented education, college students are only content with the courses required now which leads to the lack of large scope of expertise and ability to solve practical problems, being narrow-minded, and having poor flexibility, creativity and manipulative ability. With the addition of the significant differences between the campus and the society, many college graduates always have the feeling of maladjuslanent when entering the society, for example, they are usually lack of effective learning methods, strong social responsibilities and self-learning abilities and have poor understanding and mastery of professional knowledge, poor unity consciousness, poor manipulative ability in social practices and poor cognitive competence, furthermore ,they tend to have great intercommunicative obstacles and can not evaluate themselves and others correctly.展开更多
Objective: To study changes and rules of the left ventricular functions in rabbits with myocardial contusion through parallel functional analysis by using echocardiography combined with cardiac catheter intervention. ...Objective: To study changes and rules of the left ventricular functions in rabbits with myocardial contusion through parallel functional analysis by using echocardiography combined with cardiac catheter intervention. Methods: Thirty healthy rabbits were selected and impacted to make moderate or severe myocardial contusion by BIM II biomedical impact machine. The changes of hemodynamics and cardiac systolic and diastolic functions were respectively observed before injury and 1, 4, 8 and 24 hours after injury. Results: After myocardial contusion, the heart rate, systolic pressure, diastolic pressure and mean arterial pressure of rabbits decreased remarkably at 1 4 hours. The left ventricular end systolic pressure (LVESP), the maximum increasing rate of the left intraventricular pressure (+dp/dtmax), isovolumic pressure (IP) and the maximum systolic velocity of the left ventricle (Vmax) also decreased markedly. And then these parameters recovered to the level of preinjury at 8 24 hours. The left ventricular end diastolic pressure (LVEDP), the rate of the left intraventricular pressure (-dp/dtmax) and the decreasing time constant of the left intraventricular pressure (T) increased remarkably 1 hour after myocardial contusion, and did not decrease until 8 hours after myocardial contusion. Detection by echocardiography showed that ejection fraction of the left ventricle markedly decreased at 24 hours after myocardial contusion, while the systolic volume decreased obviously as early as 1 hour after myocardial contusion, at 4 8 hours it recovered a little and again decreased at 24 hours. The end systolic volume and end diastolic volume increased after myocardial contusion, but statistical significance was only seen at 8 hours after myocardial contusion.Conclusions: Cardiac functions of the left and right ventricles are markedly injured after myocardial contusion with disorders of the left ventricle diastolic function and of the right ventricle systolic function as the dominant injury. While the systolic function of the left ventricle can recover. Echocardiography shows clinical importance in detection of early injuries of cardiac functions.展开更多
Seldom could metals and alloys maintain excellent properties in cryogenic condition, such as the ductility, owing to the restrained dislocation motion.However, a face-centered-cubic(FCC) CoCrFeNi highentropy alloy(HEA...Seldom could metals and alloys maintain excellent properties in cryogenic condition, such as the ductility, owing to the restrained dislocation motion.However, a face-centered-cubic(FCC) CoCrFeNi highentropy alloy(HEA) with great ductility is investigated under the cryogenic environment. The tensile strength of this alloy can reach a maximum at 1,251±10 MPa, and the strain to failure can stay at as large as 62% at the liquid helium temperature. We ascribe the high strength and ductility to the low stacking fault energy at extremely low temperatures,which facilitates the activation of deformation twinning.Moreover, the FCC→HCP(hexagonal close-packed) transition and serration lead to the sudden decline of ductility below 77 K. The dynamical modeling and analysis of serrations at 4.2 and 20 K verify the unstable state due to the FCC→HCP transition. The deformation twinning together with phase transformation at liquid helium temperature produces an adequate strain-hardening rate that sustains the stable plastic flow at high stresses, resulting in the serration feature.展开更多
Flowers are multisensory displays used by plants to influence the behavior of pollinators. Although we know a great deal about how individual signal components are produced by plants and detected or learned by pollina...Flowers are multisensory displays used by plants to influence the behavior of pollinators. Although we know a great deal about how individual signal components are produced by plants and detected or learned by pollinators, very few experiments directly address the function of floral signal complexity, i.e. how the multicomponent nature of these signals benefits plant or pollinator. Yet, experimental psychology suggests that increasing complexity can enhance subjects' ability to detect, learn and remember stimuli, and the plant's reproductive success depends upon ensuring that pollinators learn their signals and so transport pollen to other similar (conspecific) flowers. Here we explore functional hypotheses for why plants invest in complex floral displays, focusing on hypotheses in which floral signals interact to promote pollinator learning and memory. Specifically, we discuss how an attention-altering or context-providing function of one signal may promote acquisition or recall of a second signal. Although we focus on communication between plants and pollinators, these process-based hypotheses should apply to any situation where a sender benefits from enhancing a receiver's acquisition or recall of information .展开更多
Salusins are regulatory peptides that affect cardiovascular function. We previously reported that salusin-a and -β protected cultured cardiomyocytes from serum deprivation-induced cell death through upregulating gluc...Salusins are regulatory peptides that affect cardiovascular function. We previously reported that salusin-a and -β protected cultured cardiomyocytes from serum deprivation-induced cell death through upregulating glucose-regulated protein 78 (GRP78), an endoplasmic reticulum (ER) resident protein whose overexpression acts as a marker and suppressor of ER stress. The present study examined whether salusin-α and -β inhibit ER stress in ischemic myocardium. In a rat model of myocardial infarction created by ligating the left anterior descending coronary artery (LAD), salusin-α or -β was intravenously injected at 5 or 15 nmol kg-1 15 min prior to 2 h of LAD occlusion. The high dose of salusin-α and -β3 significantly improved heart function and hemodynamics in LAD-occluded rats, but had no effects in sham-operated rats. The arrhythmias caused by LAD oc- clusion were markedly attenuated by salusin-α and -β. The apoptotic rate in ischemic myocardium was reduced from 31.5%±3.7% to 19.8%±2.2% and 12.3%±2.2%, and the infarct size was reduced from 53.4%±4.0% of the risk area to 26.5%±9.7% and 23.7%±8.9% by 15 nmol kg-1 salusin-α and -β, respectively. Furthermore, salusin-α and -β prevented the ac- tivation of GRP78 and ER stress-specific apoptotic effectors caspase-12 and CHOP (C/EBP homologous protein), and attenu- ated the reduction of an ER stress-associated antiapoptotic protein Bcl-2 in ischemic cardiac tissue. The salusins also inhibited the ER stress induced by tunicamycin in cultured rat H9c2 cardiomyocytes. These results indicate that salusins protect myo- cardium against ischemic injury by inhibiting ER stress and ER stress-associated apoptosis.展开更多
文摘The paper discusses SL learners' lexical competence from O'Connor's Five Steps of Vocabulary Acquisition Theory, Collins & Loftus's Semantic Network Theory and Fay & Cutler's Mental Lexicon Theory. From the discussion, the author finds that second language learners' lexical competence includes the following aspects: the ability to recall the words which are similar to the target words in spelling and pronunciation; the ability to recall the synonyms of the target words; the ability to recall the antonyms of the target words; and the ability to recall the related words which come together with the target words in a context. Meanwhile it advances some strategies to develop the corresponding competence.
基金Department of Science and Technology (India) for the financial support (Grant No.SR/S3/MERC/0116/2012)
文摘Functionally graded Al/B_4C, Al/Si C, Al/Al_2O_3 and Al/TiB_2 composites with constant 12%(mass fraction) of reinforcement were fabricated by centrifugal casting and hollow cylindrical components were obtained. Microstructural characteristics were investigated at outer surface of all composites and segregation of reinforcement particles was observed. Graded property of the composites with different reinforcements was investigated through hardness and tensile measurements. Results revealed that the outer peripheries of all composites exhibit higher hardness except in Al/B_4C composite and the outer zones of all composites show higher tensile strength. Abrasive wear test was conducted on the outer peripheries of all composites and Al/TiB_2 composite exhibits less wear rate.
文摘Heart failure (HF) with preserved ejection fraction (HFpEF) is the most common form of HF in older adults, and is increasing in preva- lence as the population ages. Furthermore, HFpEF is increasing out of proportion to HF with reduced EF (HFrEF), and its prognosis is worsening while that of HFrEF is improving. Despite the importance of HFpEF, our understanding of its pathophysiology is incomplete, and optimal treatment remains largely undefined. A cardinal feature of HFpEF is reduced exercise tolerance, which correlates with symptoms as well as reduced quality of life. The traditional concepts of exercise limitations have focused on central dysfimction related to poor cardiac pump function. However, the mechanisms are not exclusive to the heart and lungs, and the understanding of the pathophysiology of this dis- ease has evolved. Substantial attention has focused on defining the central versus peripheral mechanisms underlying the reduced functional capacity and exercise tolerance among patients with HF. In fact, physical training can improve exercise tolerance via peripheral adaptive mechanisms even in the absence of favorable central hemodynamic function. In addition, the drug trials performed to date in HFpEF that have focused on influencing cardiovascular function have not improved exercise capacity. This suggests that peripheral limitations may play a significant role in HF limiting exercise tolerance, a hallmark feature of HFpEF.
文摘Stiffening-ribbed-hollow-pipe cast-in place reinforced concrete girderless floor is a new-style hollow girderless floor system. Model experimental researches of simply-supported floor and four-corners bearing floor have been done on this new kind of floor system in this paper. The experiment results show that the floor system has good mechanical property such as high bearing capacity, big rigidity and good tensility. A theoretical method is presented in this paper that the stiffening-ribbed-hollow-pipe girderless floor can be analyzed by being converted equivalently to orthotropic solid slab. It is indicated that the method is correct and reasonable according to the contrast between theoretical calculated results and experimental measured results. The theoretical results coincide with the measured results well.
文摘Background: Recent data suggest that beta-blockers can be beneficial in patients with chronic heart failure (CHF). Atrial fibrillation (AF) is present in a significant number of patients with CHF and is associateing with significant morbidity and increasing mortality rates. Thus it is necessary to establish therapy to improve the poor prognosis in this high-risk population, but a specific benefit of beta-blockers to the subset with concomitant AF and CHF has been little demonstrated. Objective: To examine the effects of Bisoprolol (6 months treatment) on the ventricular function and hemodynamics in patients with AF and CHF. Methods: 84 patients with stable CHF (NYHA≤Ⅲ class) and AF were assigned to Treated Group( n = 37) or Control group Ⅰ ( n = 22, 24-hour heart mean rate < 70/min) or Control Group Ⅱ ( n = 25, 24-hour heart mean rate ≥ 70/min) . All patients were given the basic therapy for CHF, and Treated Group received Bisopolol. Clinical and echocardiographic variables were measured in 3 groups at baseline and after 6 months, and the results were compared . Results: After 6 months of treatment with Bisoprolol, left ventricular ejection fraction (LVEF) and NYHA class had significandy improved (P < 0.05), and a trend towards a reduction in combined end point of death or CHF hospitalization was also observed (P < 0.20) in Treated Group; The increase of LVEF in Treated Group were associated with a reduction in mitral regurgitation degree and left atrial volume; The heart rate in mean 24-hour and at peak exercise decreased in Treated Group, but were similar to that in Control Group Ⅰ. Conclusion: 6 months of Bisoprolol therapy resulted in an improvement in the NYHA class and LVEF, and also showed a trend towards a reduction in hospitalization or death. The beneficial effects of Bisoprolol on patients with AF and CHF may be partly mediated by improvement of ventricular diastolic function.
文摘Good psychological quality is an integral part of the overall quality of the contemporary college students, which is also an important foundation for their healthy growth and success. However, according to the investigation, in reality, many college students have various degrees of psychological problems, seriously affecting their normal learning and living. This article makes an in-depth discussion based on the analysis of contemporary college students' psychological quality system; in order to strengthen the mental health education and improve the students' adaptability.
文摘Motion sickness is one of the main reasons why travelling by sea becomes a bad memory for a number of people, mainly due to a nauseating symptom. The aim of this paper is to characterize a condition called seasickness that has affected many people from a mathematical and psychological point of view. Based on the mathematical characterization, an existing model will be reviewed and described. In the psychological aspects, a statistical study of two hundred and thirteen people was performed in order to provide a comprehensive view of the different psychological factors affecting the passengers. Motion sickness also impacts onboard safety, as it reduces the effectiveness and the operating capability of the crew when responding to hazardous situations.
文摘It is to conduct the teaching exploration for the situational sports model's implementation in sports teaching. It is indicated that the implementation of the situational teaching is good to improve the students' initiative and interest for study; good for the students' participation; good to improve students' initiative, sports ability and sports level; good to promote students to have healthy physical and psychological development; good to optimize the teaching process and activate the class atmosphere; and also good to promote students' social development factor. It is an ideal teaching concept and teaching model.
基金supported by the Land&Resources Ministry of China,the China Geological Survey and the research institute of prospecting technology in the Chinese Academy of Geological Sciences,sincere thanks heresupported by National Natural Science Foundation of China(Grant Nos.41272331,51204027)the State Key Laboratory of Geohazard Prevention&Geoenvironment Protection(Grant Nos.SKLGP2012Z007,SKLGP2014Z001,SKLGP2015Z010)
文摘How to find more effective way to stabilize the borehole wall in the fault gouge section is the key technical challenge to control the stability of the borehole wall in the Wenchuan fault gouge section during the process of core drilling. Here we try to describe the characters of deep fault gouge in fracture zones from the undisturbed fault gouge samples which are obtained during the core drilling. The X- Ray Diffraction (XRD), X-Ray Fluorescence (XRF) and Scanning Electron Microscope (SEM) provided the detailed information of the fault gouge's microscopic characteristics on the density, moisture content, expansibility, dispersity, permeability, tensile strength and other main physical-mechanical properties. Based on these systematic experimental studies above and analysis of the fault gouge instability mechanism, a new technical procedure to stabilize the borehole wall is proposed -- a low water and a low loss low permeability drilling fluid system that consists of 4% day + 0.5% CMC-HV + 2% S-1 + 3%sulfonated asphalt + 1% SMC + 0.5% X-1 + 0-5% T type lubricant + barite for core drilling in fault gouge sections.
文摘Since China's reform and accession to the world trade organization (WTO), the international labor division, cooperation, and communication of production have been a direction of the global productivity development. The expansion of the world trade organization and the growth of multinational corporations have promoted China's market economy to head for internationalization; the exchanges of all countries' science and technology, culture, and education have become increasingly frequent and beyond the borders very early, so opening-up has become a world trend. China is playing an important role in this historical process. In this situation, the importance of language translation is increasing day by day, and an unprecedented prosperous situation has especially appeared to the interpretation. In order to accord with this new historical situation, many colleges and universities have set up language translation program and have offered interpretation course. To promote the economic development of China and train more senior interpreters, the studies of interpretation teaching and the improvement of interpretation teaching quality have been particularly important. In this paper, the relationship among memory, note-taking, and psychological factors are analyzed.
文摘After several years of intense study, the most urgent problem those college students must face is employment, what' s more, with the sustaining development of China' s economy and the accelerating pace of social progress, the society shows much more need for the comprehensiveness and adaptation ability of talents. However, under the influence of long-term examination-oriented education, college students are only content with the courses required now which leads to the lack of large scope of expertise and ability to solve practical problems, being narrow-minded, and having poor flexibility, creativity and manipulative ability. With the addition of the significant differences between the campus and the society, many college graduates always have the feeling of maladjuslanent when entering the society, for example, they are usually lack of effective learning methods, strong social responsibilities and self-learning abilities and have poor understanding and mastery of professional knowledge, poor unity consciousness, poor manipulative ability in social practices and poor cognitive competence, furthermore ,they tend to have great intercommunicative obstacles and can not evaluate themselves and others correctly.
文摘Objective: To study changes and rules of the left ventricular functions in rabbits with myocardial contusion through parallel functional analysis by using echocardiography combined with cardiac catheter intervention. Methods: Thirty healthy rabbits were selected and impacted to make moderate or severe myocardial contusion by BIM II biomedical impact machine. The changes of hemodynamics and cardiac systolic and diastolic functions were respectively observed before injury and 1, 4, 8 and 24 hours after injury. Results: After myocardial contusion, the heart rate, systolic pressure, diastolic pressure and mean arterial pressure of rabbits decreased remarkably at 1 4 hours. The left ventricular end systolic pressure (LVESP), the maximum increasing rate of the left intraventricular pressure (+dp/dtmax), isovolumic pressure (IP) and the maximum systolic velocity of the left ventricle (Vmax) also decreased markedly. And then these parameters recovered to the level of preinjury at 8 24 hours. The left ventricular end diastolic pressure (LVEDP), the rate of the left intraventricular pressure (-dp/dtmax) and the decreasing time constant of the left intraventricular pressure (T) increased remarkably 1 hour after myocardial contusion, and did not decrease until 8 hours after myocardial contusion. Detection by echocardiography showed that ejection fraction of the left ventricle markedly decreased at 24 hours after myocardial contusion, while the systolic volume decreased obviously as early as 1 hour after myocardial contusion, at 4 8 hours it recovered a little and again decreased at 24 hours. The end systolic volume and end diastolic volume increased after myocardial contusion, but statistical significance was only seen at 8 hours after myocardial contusion.Conclusions: Cardiac functions of the left and right ventricles are markedly injured after myocardial contusion with disorders of the left ventricle diastolic function and of the right ventricle systolic function as the dominant injury. While the systolic function of the left ventricle can recover. Echocardiography shows clinical importance in detection of early injuries of cardiac functions.
基金supported in part by the Nationa Natural Science Foundation of China (51471025, 51671020, 51471024 and 11771407)the Department of Energy (DOE), Office of Fossil Energy, National Energy Technology Laboratory (DE-FE-0011194)+1 种基金the support from the US Army Research Office project (W911NF-13-1-0438)the support from the National Science Foundation (DMR-1611180 and 1809640)
文摘Seldom could metals and alloys maintain excellent properties in cryogenic condition, such as the ductility, owing to the restrained dislocation motion.However, a face-centered-cubic(FCC) CoCrFeNi highentropy alloy(HEA) with great ductility is investigated under the cryogenic environment. The tensile strength of this alloy can reach a maximum at 1,251±10 MPa, and the strain to failure can stay at as large as 62% at the liquid helium temperature. We ascribe the high strength and ductility to the low stacking fault energy at extremely low temperatures,which facilitates the activation of deformation twinning.Moreover, the FCC→HCP(hexagonal close-packed) transition and serration lead to the sudden decline of ductility below 77 K. The dynamical modeling and analysis of serrations at 4.2 and 20 K verify the unstable state due to the FCC→HCP transition. The deformation twinning together with phase transformation at liquid helium temperature produces an adequate strain-hardening rate that sustains the stable plastic flow at high stresses, resulting in the serration feature.
文摘Flowers are multisensory displays used by plants to influence the behavior of pollinators. Although we know a great deal about how individual signal components are produced by plants and detected or learned by pollinators, very few experiments directly address the function of floral signal complexity, i.e. how the multicomponent nature of these signals benefits plant or pollinator. Yet, experimental psychology suggests that increasing complexity can enhance subjects' ability to detect, learn and remember stimuli, and the plant's reproductive success depends upon ensuring that pollinators learn their signals and so transport pollen to other similar (conspecific) flowers. Here we explore functional hypotheses for why plants invest in complex floral displays, focusing on hypotheses in which floral signals interact to promote pollinator learning and memory. Specifically, we discuss how an attention-altering or context-providing function of one signal may promote acquisition or recall of a second signal. Although we focus on communication between plants and pollinators, these process-based hypotheses should apply to any situation where a sender benefits from enhancing a receiver's acquisition or recall of information .
基金supported by the National Basic Research Program of China (Grant Nos. 2006CB503807 and 2009CB521902)the National Natural Science Foundation of China (Grant Nos. 30600763, 30870906, and 31071023)+2 种基金the Pujiang Project of Shanghai, China (Grant No.08PJ14001)the Project Sponsored by the Scientific Research Foundation for the Returned Overseas Chinese Scholars, Ministry of Education of China (Grant No. [2008]891)the Fund for Outstanding Young Teachers in Higher Education Institutions of Shanghai, China (Grant No.[2009]63)
文摘Salusins are regulatory peptides that affect cardiovascular function. We previously reported that salusin-a and -β protected cultured cardiomyocytes from serum deprivation-induced cell death through upregulating glucose-regulated protein 78 (GRP78), an endoplasmic reticulum (ER) resident protein whose overexpression acts as a marker and suppressor of ER stress. The present study examined whether salusin-α and -β inhibit ER stress in ischemic myocardium. In a rat model of myocardial infarction created by ligating the left anterior descending coronary artery (LAD), salusin-α or -β was intravenously injected at 5 or 15 nmol kg-1 15 min prior to 2 h of LAD occlusion. The high dose of salusin-α and -β3 significantly improved heart function and hemodynamics in LAD-occluded rats, but had no effects in sham-operated rats. The arrhythmias caused by LAD oc- clusion were markedly attenuated by salusin-α and -β. The apoptotic rate in ischemic myocardium was reduced from 31.5%±3.7% to 19.8%±2.2% and 12.3%±2.2%, and the infarct size was reduced from 53.4%±4.0% of the risk area to 26.5%±9.7% and 23.7%±8.9% by 15 nmol kg-1 salusin-α and -β, respectively. Furthermore, salusin-α and -β prevented the ac- tivation of GRP78 and ER stress-specific apoptotic effectors caspase-12 and CHOP (C/EBP homologous protein), and attenu- ated the reduction of an ER stress-associated antiapoptotic protein Bcl-2 in ischemic cardiac tissue. The salusins also inhibited the ER stress induced by tunicamycin in cultured rat H9c2 cardiomyocytes. These results indicate that salusins protect myo- cardium against ischemic injury by inhibiting ER stress and ER stress-associated apoptosis.