Modified classical Boltzmann entropy as generalized entropy, then proposed Maximum Generalized Entropy Principle fusing physics and biology, and established a new model for biological origin and evolutions based on th...Modified classical Boltzmann entropy as generalized entropy, then proposed Maximum Generalized Entropy Principle fusing physics and biology, and established a new model for biological origin and evolutions based on this principle, finally took protein evolution for an example to analyze. The model provided some reference for biological complexity research.展开更多
The pharmacokinetics of a sustained- release formulation and an enteric- coated tablet of diclofenac sodium were studied on 8 healthy male volunteers in an open,randomized crossover study.Drug level in serum was assay...The pharmacokinetics of a sustained- release formulation and an enteric- coated tablet of diclofenac sodium were studied on 8 healthy male volunteers in an open,randomized crossover study.Drug level in serum was assayed by HPLC method.The changes in serum concentration were conformed to a l-compartment open model.The t_1/2 (Ke)averaged 2.15±0.17 and ll.60 ± l.95 h,and the areas under the drug concentration curves were 5.87 ± 0.67 and 5.55 ± 0.57μgh/ml for enteric-coated and sustained-release tablet of diclofenac sodium,respectively. The mean relative bioavailability of sustained-release tablet was 0.95 to that of enteric-coated tablet.展开更多
Hypertensive crises are elevations of blood pressure higher than 180/120 mmHg. These can be urgent or emergent, depending on the presence of end organ damage. The clinical presentation of hypertensive crises is quite ...Hypertensive crises are elevations of blood pressure higher than 180/120 mmHg. These can be urgent or emergent, depending on the presence of end organ damage. The clinical presentation of hypertensive crises is quite variable in elderly patients, and clinicians must be suspicious of non-specific symptoms. Managing hypertensive crises in elderly patients needs meticulous knowledge of the pathophysiological changes in them, pharmacological options, pharmacokinetics of the medications used, their side effects, and their interactions with other medications. Clevidipine, nicardipine, labetalol, esmolol, and fenoldopam are among the preferred choices in the elderly due to their efficacy and tolerability. Nitroprusside, hydralazine, and nifedipine should be avoided, unless there are no other options available, due to the high risk of complications and unpredictable responses.展开更多
Algal allelopathy is a manifold ecological/physiological phenomenon that is focused on chemical interactions and autotoxicity. We investigated the allelopathic interactions between Karenia mikimotoi and Dunaliella sal...Algal allelopathy is a manifold ecological/physiological phenomenon that is focused on chemical interactions and autotoxicity. We investigated the allelopathic interactions between Karenia mikimotoi and Dunaliella salina in laboratory cultures based on different temperature (15℃, 20℃, and 25℃) and lighting (40,80, and 160 umol/(m2·s)) conditions. The growth of D. salina in bi-algae culture (1:1 size/density) was significantly restrained. The results of cell-free filtrate culture indicate that direct cell-to- cell contact was not necessary in interspecific competition. Further experimental results demonstrated that allelochemicals released from K. miMmotoi were markedly influenced by both temperature (P=0.013) and irradiance (P=0.003), resulting in different growth characteristics olD. salina in filtrate mediums. Compared with the plateau period, K. mikimotoi exudates in the exponential phase had a stronger short-term inhibition effect on D. salina in normal conditions. A clear concentration-dependent relationship was observed in the effect of allelochemicals released from K. mikimotoi with low-promoting and high-repressing effects on D. Salina in a short time-scale. In addition, allelopathic substances remain stable and effective under high temperature and pressure stress. Many flocculent sediments adhering with D. salina cells were observed in all filtrate mediums, while the quantity and color depended on the original culture conditions.展开更多
Most current theories of second language acquisition and current views on methods and approaches to teaching English as a second language place a high value on student participation and interaction in the language cla...Most current theories of second language acquisition and current views on methods and approaches to teaching English as a second language place a high value on student participation and interaction in the language classroom. This interaction may be between teacher and student and/or student and student. Despite this, in many English classrooms around the world, students have very few opportunities to interact in the second language. In this paper, using the literature on second language acquisition research and methodology to prepare a case which highlights why teachers and course designers should find ways to incorporate second language interaction and student participation in their language classes despite the practical difficulties they may face.展开更多
Research on learning difficulties in mathematics adopts one of two distinct perspectives. According to the first, learning difficulties are due to the intrinsic characteristics of the student. For supporters of the se...Research on learning difficulties in mathematics adopts one of two distinct perspectives. According to the first, learning difficulties are due to the intrinsic characteristics of the student. For supporters of the second perspective, those difficulties result from the interaction between the student and the school system. The objective of this study is to test the validity of these two perspectives in interpreting learning difficulties in mathematics among at-risk students. To this end, we collaborated with normally achieving (undiagnosed) and at-risk students. Results show that the second perspective is better suited to the interpretation of learning difficulties in mathematics students展开更多
Schema is known to play an important role in reading comprehension. The schema embodying the learners background knowledge of cultural familiar materials facilitates the understanding of the text (Pritchard, 1990). ...Schema is known to play an important role in reading comprehension. The schema embodying the learners background knowledge of cultural familiar materials facilitates the understanding of the text (Pritchard, 1990). Also Steffensen, Joag-Dev, and Anderson (1979) and Nelson (1987) proposed that the schemata embodying background knowledge influenced how well the text would be comprehended. However, Hudson (1982) and Carrell (1984) found there was no significant background effect in advanced level learners. From those studies, it seems that background effect is different at different language proficiency levels. Thus, the present study examines the interaction between background knowledge and language proficiency in reading comprehension. The participants were freshmen of National Chiayi University. They were divided into three language proficiency levels based on the General English Proficiency Test. Four reading comprehension tests were constructed to assess their reading comprehension: cultural familiar/unfamiliar text and topic familiar/unfamiliar text. The results of this study showed that participants had better performance on the culture/topic familiar text than the culture/topic unfamiliar text. Thus the findings suggest that the teacher can use teaching activities, such as pre-reading activities or vocabulary teaching to increase the background knowledge when teaching readings to EFL (English as a foreign language) learners展开更多
In this paper, four recent advances and achievements of China in agricultural insect research, namely, on the genome of silkworm (Bombyx mori Linnaeus), on the geographical differentiation and regional migration of co...In this paper, four recent advances and achievements of China in agricultural insect research, namely, on the genome of silkworm (Bombyx mori Linnaeus), on the geographical differentiation and regional migration of cotton bollworm (Helicoverpa armigera (Hübner)), on the standardized monitoring techniques for safety of honey bee (Apis mellifera Linnaeus) products, and on the virus transmission property of small brown planthopper (Laodelphax striatellus (Fallén)) as well as the interactions between vector and rice stripe virus (RSV), were reported. All of these researches are very important for controlling agricultural insect pests and the diseases they transmit, accelerating the molecular biological research of silkworm, and promoting the international trade of honey bee products. Most of these achievements mentioned above have got the national, provincial, ministerial or municipal awards on science and technology.展开更多
A year-long survey of some physical parameters (water temperature, dissolved oxygen, pH, turbidity), chemical parameters (Biological Oxygen Demand "BOD", Chemical Oxygen Demand "COD", nitrate, ammonia, orthopho...A year-long survey of some physical parameters (water temperature, dissolved oxygen, pH, turbidity), chemical parameters (Biological Oxygen Demand "BOD", Chemical Oxygen Demand "COD", nitrate, ammonia, orthophosphate) and some biological (zooplankton) and microbiological (total bacteria, indicator bacteria, pathogenic bacteria) components in Domat AI-Gandal Lake was conducted. Water samples were collected seasonally from spring 2004 to winter 2005. Four locations on the Lake were sampled in order to evaluate the condition of the Lake. To investigate the possible effect of zooplankton in controlling the presence of faecal indicator bacteria, a 24 hour experiment was carried out to examine this hypothesis as well as the grazing pressure of zooplankton on the bacterial community of the Lake. The results showed that variations in season temperature affected the zooplankton and density of bacteria in the Lake. Zooplankton was composed by Protozoa 75%, Rotifera 20.6%, Cladocera 3% and Copepoda 2%. The reduction rates for the tested faecal pollution indicators in presence of zooplankton predators were remarkable (up to 99%). In conclusion zooplankton, especially protozoa, was found to play an important role as biological control against bacterial indicators of faecal pollution.展开更多
One of the major obstacles facing the field of structural biology in the post genomic era is the inherent difficulty of analyzing the structure of membrane proteins under native conditions. The method of choice for st...One of the major obstacles facing the field of structural biology in the post genomic era is the inherent difficulty of analyzing the structure of membrane proteins under native conditions. The method of choice for studying such proteins is FTIR spectroscopy. Following the outbreaking of the severe acute respiratory syndrome (SARS) virus, in 2003, extensive work has been directed at elucidating the structure of the E transmembrane proteins of the SARS coronavirus. In this study, the secondary structure of the transmembrane a-helical bundles was analysised using the biophysical method site specific infrared dichroism (SSID). Sixteen amino acids were isotopically labeled with (~3C=180) at different positions of the primary structure of the synthesized E protein CoV. The secondary structure was studied using Attenuated Total Internal Reflection (ATR) FTIR spectroscopy. Based on our findings, the presence of two possible H-bonding interactions between the carbonyl oxygen of two residues 26 and 31 (Phe and Leu) respectively with water molecules which may be trapped within the helix structure were postulatesed. These interactions may cause a change in this structure.展开更多
Geomicrobiology is a sub-discipline of geobiology and emphasizes the interaction between microorganisms and their environment on Earth. There is a need to explicitly emphasize the biogeochemical processes performed by...Geomicrobiology is a sub-discipline of geobiology and emphasizes the interaction between microorganisms and their environment on Earth. There is a need to explicitly emphasize the biogeochemical processes performed by microorganisms associated with Earth's tectonic activities, especially under the framework of the modern theory of plate tectonics. Tectonomicrobiology aims to create a better synergy between microbial and active tectonic processes. This explicit synergy should also foster better communications between solid Earth scientists and life scientists in terms of holistic Earth system dynamics at both tectonic and micro-scales.展开更多
The Hedgehog (Hh) signaling pathway plays important roles in developmental processes including pattern formation and tissue homeostasis. The seven-pass transmembrane receptor Smoothened (Smo) is the pivotal transd...The Hedgehog (Hh) signaling pathway plays important roles in developmental processes including pattern formation and tissue homeostasis. The seven-pass transmembrane receptor Smoothened (Smo) is the pivotal transducer in the pathway; it, and thus the pathway overall, is regulated by ubiquitin-mediated degradation, which occurs in the absence of Hh. In the presence of Hh, the ubiquitination levels of Smo are decreased, but the molecular basis for this outcome is not well understood. Here, we identify the deubiquitinase UCHL5 as a positive regulator of the Hh pathway. We provide both genetic and biochemical evidence that UCHL5 interacts with and deubiquitinates Smo, increasing stability and promoting accumulation at the cell membrane. Strikingly, we find that Hh enhances the interaction between UCHL5 and Smo, thereby stabilizing Smo. We also find that proteasome subunit RPN13, an activator of UCHL5, could enhance the effect of UCHL5 on Smo protein level. More importantly, we find that the mammalian counterpart of UCHL5, UCH37, plays the same role in the regulation of Hh signaling by modulating hSmo ubiquitination and stability. Our findings thus identify UCHL5/UCH37 as a critical regulator of Hh signaling and potential therapeutic target for cancers.展开更多
Membrane proteins are involved in various critical biological processes,and studying membrane proteins represents a major challenge in protein biochemistry.As shown by both structural and functional studies,the membra...Membrane proteins are involved in various critical biological processes,and studying membrane proteins represents a major challenge in protein biochemistry.As shown by both structural and functional studies,the membrane environment plays an essential role for membrane proteins.In vitro studies are reliant on the successful reconstitution of membrane proteins.This review describes the interaction between detergents and lipids that aids the understanding of the reconstitution processes.Then the techniques of detergent removal and a few useful techniques to refine the formed proteoliposomes are reviewed.Finally the applications of reconstitution techniques to study membrane proteins involved in Ca2+ signaling are summarized.展开更多
The bionic consciousness,idea,and practice opened a unique path for the progress of mankind,the development of the society,and the innovation of science and technology from the subconscious bionic activities of the an...The bionic consciousness,idea,and practice opened a unique path for the progress of mankind,the development of the society,and the innovation of science and technology from the subconscious bionic activities of the ancient humans to the significant bionic designs in modern engineering.Nowadays,driven by the practical demand of human beings,bionics becomes an important factor for the sustainable development of technology.A lot of new and outstanding innovations have been produced through the effective interactions between bionics,technology,and demand.The stronger the interactions,the greater the innovation success would be.In this article,the basic factors such as the connotation,characteristics,and interactions of bionic demands,bionic models,bionic simulations,and bionic products were explained,which are the indispensable basic knowledge for improving the ability of innovation especially for the original one,realizing the design and innovation of new technology and manufacturing for better bionic products.展开更多
Understanding and replicating the locomotion principles offish are fundamental in the development of artificial fishlike robotic systems,termed robotic fish.This paper has two objectives:(1) to review biological clues...Understanding and replicating the locomotion principles offish are fundamental in the development of artificial fishlike robotic systems,termed robotic fish.This paper has two objectives:(1) to review biological clues on biomechanics and hydrodynamic flow control offish swimming and(2) to summarize design and control methods for efficient and stable swimming in robotic fishes.Our review of state-of-the-art research and future-oriented new directions indicates that fish-inspired biology and engineering interact in mutually beneficial ways.This strong interaction offers an important insight into the design and control of novel fish-inspired robots that addresses the challenge of environmental uncertainty and competing objectives;in addition,it also facilitates refinement of biological knowledge and robotic strategies for effective and efficient swimming.展开更多
A series of new benzimidazole derivatives was synthesized and characterized by IR,1H NMR,13C NMR,MS,and HRMS spectra.All the new compounds were screened for their antimicrobial activities in vitro by a twofold serial ...A series of new benzimidazole derivatives was synthesized and characterized by IR,1H NMR,13C NMR,MS,and HRMS spectra.All the new compounds were screened for their antimicrobial activities in vitro by a twofold serial dilution technique.The bioactive evaluation showed that 3,5-bis(trifluoromethyl)phenyl benzimidazoles were comparably or even more strongly antibacterial and antifungal than the reference drugs Chloromycin,Norfloxacin,and Fluconazole.The combination of2,4-difluorobenzyl benzimidazole derivative 5l and its hydrochloride 7 respectively with the antibacterials Chloromycin,Norfloxacin,and the antifungal Fluconazole was more sensitive to methicillin-resistant MRSA and Fluconazole-insensitive A.flavus.In addition,the interaction of compound 5l with calf thymus DNA demonstrated that this compound could effectively intercalate into DNA to form a compound 5l-DNA complex that might block DNA replication and thereby exert good antimicrobial activity.展开更多
In the United States, prostitution is considered illegal in all but one state; Nevada allows some legal activities in exchange for substantial guidelines. In 2010, approxi- mately 43,600 females were arrested for pros...In the United States, prostitution is considered illegal in all but one state; Nevada allows some legal activities in exchange for substantial guidelines. In 2010, approxi- mately 43,600 females were arrested for prostitution. Numerous intervention programs were established in order to obstruct the lifestyle of a prostitute (PRP~ Project ROSE, etc.). There are many documentations and programs that share their forethought on prostitution; however, few target prostitution directly. To determine the dynamics of prostitution, this paper constructs a four-class compartmental model that focuses on the effectiveness of government intervention and rehabilitation of prostitutes mathematically. The basic reproductive number, R0, helps to discover the threshold values for the dynamics of prostitution to become both prevalent or absent in society. This paper predominately observes government intervention to curtail a prostitution prevalent society. Various parameters and variables help to define and indicate the dynamics of pros- titution to construct viable simulations. Successful prostitution interaction prevention deemed essential in prostitution prevention; however, government intervention corresponding with successful rehabilitation competitively challenges prostitution interaction prevention in reducing basic reproductive values.展开更多
This paper reports a study designed to observe how a learning community arose when a group of learners of English focused on a common project. The students' task was to participate as speakers in an international con...This paper reports a study designed to observe how a learning community arose when a group of learners of English focused on a common project. The students' task was to participate as speakers in an international conference. Undergraduate students in a course of Business English at a small private university in western Mexico worked in teams to research and develop a topic to be sent as a proposal to the conference.The study used Interaction Analysis with a qualitative focus to observe participant interactions. Video and audio recordings were supplemented with participant interviews and questionnaires. Analysis shows that in the course of the project, the students learned not only business terminology, but also how to work together.展开更多
Kynurenine aminotransferases (KATs) catalyze the transamination of kynurenine (KYN) pathway and endogenous KYNs have been suggested to highly correlate to abnormal brain diseases. HKAT3 is a key member of KAT fami...Kynurenine aminotransferases (KATs) catalyze the transamination of kynurenine (KYN) pathway and endogenous KYNs have been suggested to highly correlate to abnormal brain diseases. HKAT3 is a key member of KAT family, while the binding mechanism of KYN and cofactor with HKAT3 has not been determined yet. In this study, we focus on the structure-function relationship among KYN, cofactor and HKAT3. The binding models of KYN complex and KYN&cofactor complex were ob- tained and were studied by molecular dynamics (MD) simulations. We identified several critical residues and influence of conformational changes in human kynurenine aminotransferase 3 (HKAT3) complexes. The cofactor may contribute largely not only to the catalysis, but also to the binding. In addition, a hypothesis is proposed that a strong hydrophobic interaction between Tyr159 and Lys280 may influence the binding mode and the binding region of the substrate and the cofactor. Our re- suits will be a good starting point for further determination of the biological role.展开更多
基金Supported by National Basic Research Program of China (973 Program) (Grant No. 2007CB714101)~~
文摘Modified classical Boltzmann entropy as generalized entropy, then proposed Maximum Generalized Entropy Principle fusing physics and biology, and established a new model for biological origin and evolutions based on this principle, finally took protein evolution for an example to analyze. The model provided some reference for biological complexity research.
文摘The pharmacokinetics of a sustained- release formulation and an enteric- coated tablet of diclofenac sodium were studied on 8 healthy male volunteers in an open,randomized crossover study.Drug level in serum was assayed by HPLC method.The changes in serum concentration were conformed to a l-compartment open model.The t_1/2 (Ke)averaged 2.15±0.17 and ll.60 ± l.95 h,and the areas under the drug concentration curves were 5.87 ± 0.67 and 5.55 ± 0.57μgh/ml for enteric-coated and sustained-release tablet of diclofenac sodium,respectively. The mean relative bioavailability of sustained-release tablet was 0.95 to that of enteric-coated tablet.
文摘Hypertensive crises are elevations of blood pressure higher than 180/120 mmHg. These can be urgent or emergent, depending on the presence of end organ damage. The clinical presentation of hypertensive crises is quite variable in elderly patients, and clinicians must be suspicious of non-specific symptoms. Managing hypertensive crises in elderly patients needs meticulous knowledge of the pathophysiological changes in them, pharmacological options, pharmacokinetics of the medications used, their side effects, and their interactions with other medications. Clevidipine, nicardipine, labetalol, esmolol, and fenoldopam are among the preferred choices in the elderly due to their efficacy and tolerability. Nitroprusside, hydralazine, and nifedipine should be avoided, unless there are no other options available, due to the high risk of complications and unpredictable responses.
基金Supported by the State Key Laboratory of Satellite Ocean Environment Dynamics(Second Institute of Oceanography,SOA)(No.SOED1418)the Public Science and Technology Research Funds Projects of Ocean(No.201305027)+1 种基金the National Natural Science Foundation of China(No.91128212)the Research Fund for the Doctoral Program of Higher Education of China(No.20110132120025)
文摘Algal allelopathy is a manifold ecological/physiological phenomenon that is focused on chemical interactions and autotoxicity. We investigated the allelopathic interactions between Karenia mikimotoi and Dunaliella salina in laboratory cultures based on different temperature (15℃, 20℃, and 25℃) and lighting (40,80, and 160 umol/(m2·s)) conditions. The growth of D. salina in bi-algae culture (1:1 size/density) was significantly restrained. The results of cell-free filtrate culture indicate that direct cell-to- cell contact was not necessary in interspecific competition. Further experimental results demonstrated that allelochemicals released from K. miMmotoi were markedly influenced by both temperature (P=0.013) and irradiance (P=0.003), resulting in different growth characteristics olD. salina in filtrate mediums. Compared with the plateau period, K. mikimotoi exudates in the exponential phase had a stronger short-term inhibition effect on D. salina in normal conditions. A clear concentration-dependent relationship was observed in the effect of allelochemicals released from K. mikimotoi with low-promoting and high-repressing effects on D. Salina in a short time-scale. In addition, allelopathic substances remain stable and effective under high temperature and pressure stress. Many flocculent sediments adhering with D. salina cells were observed in all filtrate mediums, while the quantity and color depended on the original culture conditions.
文摘Most current theories of second language acquisition and current views on methods and approaches to teaching English as a second language place a high value on student participation and interaction in the language classroom. This interaction may be between teacher and student and/or student and student. Despite this, in many English classrooms around the world, students have very few opportunities to interact in the second language. In this paper, using the literature on second language acquisition research and methodology to prepare a case which highlights why teachers and course designers should find ways to incorporate second language interaction and student participation in their language classes despite the practical difficulties they may face.
文摘Research on learning difficulties in mathematics adopts one of two distinct perspectives. According to the first, learning difficulties are due to the intrinsic characteristics of the student. For supporters of the second perspective, those difficulties result from the interaction between the student and the school system. The objective of this study is to test the validity of these two perspectives in interpreting learning difficulties in mathematics among at-risk students. To this end, we collaborated with normally achieving (undiagnosed) and at-risk students. Results show that the second perspective is better suited to the interpretation of learning difficulties in mathematics students
文摘Schema is known to play an important role in reading comprehension. The schema embodying the learners background knowledge of cultural familiar materials facilitates the understanding of the text (Pritchard, 1990). Also Steffensen, Joag-Dev, and Anderson (1979) and Nelson (1987) proposed that the schemata embodying background knowledge influenced how well the text would be comprehended. However, Hudson (1982) and Carrell (1984) found there was no significant background effect in advanced level learners. From those studies, it seems that background effect is different at different language proficiency levels. Thus, the present study examines the interaction between background knowledge and language proficiency in reading comprehension. The participants were freshmen of National Chiayi University. They were divided into three language proficiency levels based on the General English Proficiency Test. Four reading comprehension tests were constructed to assess their reading comprehension: cultural familiar/unfamiliar text and topic familiar/unfamiliar text. The results of this study showed that participants had better performance on the culture/topic familiar text than the culture/topic unfamiliar text. Thus the findings suggest that the teacher can use teaching activities, such as pre-reading activities or vocabulary teaching to increase the background knowledge when teaching readings to EFL (English as a foreign language) learners
文摘In this paper, four recent advances and achievements of China in agricultural insect research, namely, on the genome of silkworm (Bombyx mori Linnaeus), on the geographical differentiation and regional migration of cotton bollworm (Helicoverpa armigera (Hübner)), on the standardized monitoring techniques for safety of honey bee (Apis mellifera Linnaeus) products, and on the virus transmission property of small brown planthopper (Laodelphax striatellus (Fallén)) as well as the interactions between vector and rice stripe virus (RSV), were reported. All of these researches are very important for controlling agricultural insect pests and the diseases they transmit, accelerating the molecular biological research of silkworm, and promoting the international trade of honey bee products. Most of these achievements mentioned above have got the national, provincial, ministerial or municipal awards on science and technology.
文摘A year-long survey of some physical parameters (water temperature, dissolved oxygen, pH, turbidity), chemical parameters (Biological Oxygen Demand "BOD", Chemical Oxygen Demand "COD", nitrate, ammonia, orthophosphate) and some biological (zooplankton) and microbiological (total bacteria, indicator bacteria, pathogenic bacteria) components in Domat AI-Gandal Lake was conducted. Water samples were collected seasonally from spring 2004 to winter 2005. Four locations on the Lake were sampled in order to evaluate the condition of the Lake. To investigate the possible effect of zooplankton in controlling the presence of faecal indicator bacteria, a 24 hour experiment was carried out to examine this hypothesis as well as the grazing pressure of zooplankton on the bacterial community of the Lake. The results showed that variations in season temperature affected the zooplankton and density of bacteria in the Lake. Zooplankton was composed by Protozoa 75%, Rotifera 20.6%, Cladocera 3% and Copepoda 2%. The reduction rates for the tested faecal pollution indicators in presence of zooplankton predators were remarkable (up to 99%). In conclusion zooplankton, especially protozoa, was found to play an important role as biological control against bacterial indicators of faecal pollution.
文摘One of the major obstacles facing the field of structural biology in the post genomic era is the inherent difficulty of analyzing the structure of membrane proteins under native conditions. The method of choice for studying such proteins is FTIR spectroscopy. Following the outbreaking of the severe acute respiratory syndrome (SARS) virus, in 2003, extensive work has been directed at elucidating the structure of the E transmembrane proteins of the SARS coronavirus. In this study, the secondary structure of the transmembrane a-helical bundles was analysised using the biophysical method site specific infrared dichroism (SSID). Sixteen amino acids were isotopically labeled with (~3C=180) at different positions of the primary structure of the synthesized E protein CoV. The secondary structure was studied using Attenuated Total Internal Reflection (ATR) FTIR spectroscopy. Based on our findings, the presence of two possible H-bonding interactions between the carbonyl oxygen of two residues 26 and 31 (Phe and Leu) respectively with water molecules which may be trapped within the helix structure were postulatesed. These interactions may cause a change in this structure.
基金supported by the National Natural Science Foundation of China(Grant Nos.41530105,41373072,91628301&U1606401)the Chinese Academy of Sciences(Grant Nos.Y4SL021001&QYZDY-SSW-DQC005)the Southern University of Science and Technology(Grant No.Y01316209)
文摘Geomicrobiology is a sub-discipline of geobiology and emphasizes the interaction between microorganisms and their environment on Earth. There is a need to explicitly emphasize the biogeochemical processes performed by microorganisms associated with Earth's tectonic activities, especially under the framework of the modern theory of plate tectonics. Tectonomicrobiology aims to create a better synergy between microbial and active tectonic processes. This explicit synergy should also foster better communications between solid Earth scientists and life scientists in terms of holistic Earth system dynamics at both tectonic and micro-scales.
基金This work was supported by grants from the National Basic Research Program of China (2011CB943902), the National Natural Science Foundation of China (30971679, 31071264, and 31271531), and the Fundamental Research Funds for the Central Universities (090314380019).
文摘The Hedgehog (Hh) signaling pathway plays important roles in developmental processes including pattern formation and tissue homeostasis. The seven-pass transmembrane receptor Smoothened (Smo) is the pivotal transducer in the pathway; it, and thus the pathway overall, is regulated by ubiquitin-mediated degradation, which occurs in the absence of Hh. In the presence of Hh, the ubiquitination levels of Smo are decreased, but the molecular basis for this outcome is not well understood. Here, we identify the deubiquitinase UCHL5 as a positive regulator of the Hh pathway. We provide both genetic and biochemical evidence that UCHL5 interacts with and deubiquitinates Smo, increasing stability and promoting accumulation at the cell membrane. Strikingly, we find that Hh enhances the interaction between UCHL5 and Smo, thereby stabilizing Smo. We also find that proteasome subunit RPN13, an activator of UCHL5, could enhance the effect of UCHL5 on Smo protein level. More importantly, we find that the mammalian counterpart of UCHL5, UCH37, plays the same role in the regulation of Hh signaling by modulating hSmo ubiquitination and stability. Our findings thus identify UCHL5/UCH37 as a critical regulator of Hh signaling and potential therapeutic target for cancers.
基金supported by US National Institutes of Health(R01GM096458)to Wang LiGuo
文摘Membrane proteins are involved in various critical biological processes,and studying membrane proteins represents a major challenge in protein biochemistry.As shown by both structural and functional studies,the membrane environment plays an essential role for membrane proteins.In vitro studies are reliant on the successful reconstitution of membrane proteins.This review describes the interaction between detergents and lipids that aids the understanding of the reconstitution processes.Then the techniques of detergent removal and a few useful techniques to refine the formed proteoliposomes are reviewed.Finally the applications of reconstitution techniques to study membrane proteins involved in Ca2+ signaling are summarized.
基金supported by the Cooperative Innovation Platform of National Oil Shale Exploration Development and Research,the National Natural Science Foundation for Youths(Grant Nos.51205160 and 51375006)the Specialized Research Fund for the Doctoral Program of Higher Education of China(Grant No.20120061120110)
文摘The bionic consciousness,idea,and practice opened a unique path for the progress of mankind,the development of the society,and the innovation of science and technology from the subconscious bionic activities of the ancient humans to the significant bionic designs in modern engineering.Nowadays,driven by the practical demand of human beings,bionics becomes an important factor for the sustainable development of technology.A lot of new and outstanding innovations have been produced through the effective interactions between bionics,technology,and demand.The stronger the interactions,the greater the innovation success would be.In this article,the basic factors such as the connotation,characteristics,and interactions of bionic demands,bionic models,bionic simulations,and bionic products were explained,which are the indispensable basic knowledge for improving the ability of innovation especially for the original one,realizing the design and innovation of new technology and manufacturing for better bionic products.
基金supported by the National Natural Science Foundation of China(Grant Nos.61333016,61403012,61633004&61633020)the Beijing Natural Science Foundation(Grant Nos.4154077&4161002)
文摘Understanding and replicating the locomotion principles offish are fundamental in the development of artificial fishlike robotic systems,termed robotic fish.This paper has two objectives:(1) to review biological clues on biomechanics and hydrodynamic flow control offish swimming and(2) to summarize design and control methods for efficient and stable swimming in robotic fishes.Our review of state-of-the-art research and future-oriented new directions indicates that fish-inspired biology and engineering interact in mutually beneficial ways.This strong interaction offers an important insight into the design and control of novel fish-inspired robots that addresses the challenge of environmental uncertainty and competing objectives;in addition,it also facilitates refinement of biological knowledge and robotic strategies for effective and efficient swimming.
基金supported by the National Natural Science Foundation of China (21172181,21372186)the Research Fellowship for International Young Scientists from the International (Regional) Cooperation and Exchange Program (81250110554,81350110338,81350110523)+1 种基金the key program from Natural Science Foundation of Chongqing (CSTC2012- jjB10026)the Specialized Research Fund for the Doctoral Program of Higher Education of China (20110182110007)
文摘A series of new benzimidazole derivatives was synthesized and characterized by IR,1H NMR,13C NMR,MS,and HRMS spectra.All the new compounds were screened for their antimicrobial activities in vitro by a twofold serial dilution technique.The bioactive evaluation showed that 3,5-bis(trifluoromethyl)phenyl benzimidazoles were comparably or even more strongly antibacterial and antifungal than the reference drugs Chloromycin,Norfloxacin,and Fluconazole.The combination of2,4-difluorobenzyl benzimidazole derivative 5l and its hydrochloride 7 respectively with the antibacterials Chloromycin,Norfloxacin,and the antifungal Fluconazole was more sensitive to methicillin-resistant MRSA and Fluconazole-insensitive A.flavus.In addition,the interaction of compound 5l with calf thymus DNA demonstrated that this compound could effectively intercalate into DNA to form a compound 5l-DNA complex that might block DNA replication and thereby exert good antimicrobial activity.
基金Support for this Mathematical Association of America (MAA) Program is jointly provided by the National Science Foundation (Grant DMS-1359016) and the National Security Administration (Grant H98230-15-1-0020). We thank the School for Engineering of Matter, Transport and Energy at Arizona State University (ASU) for allowing us to use their resources and facilities. A. Lanz acknowledges the support provided by the National Science Foundation HBCU-UP Research Initiation Award (Grant 074754805). Furthermore, the authors would like to thank the anonymous referees for their valuable comments and suggestions.
文摘In the United States, prostitution is considered illegal in all but one state; Nevada allows some legal activities in exchange for substantial guidelines. In 2010, approxi- mately 43,600 females were arrested for prostitution. Numerous intervention programs were established in order to obstruct the lifestyle of a prostitute (PRP~ Project ROSE, etc.). There are many documentations and programs that share their forethought on prostitution; however, few target prostitution directly. To determine the dynamics of prostitution, this paper constructs a four-class compartmental model that focuses on the effectiveness of government intervention and rehabilitation of prostitutes mathematically. The basic reproductive number, R0, helps to discover the threshold values for the dynamics of prostitution to become both prevalent or absent in society. This paper predominately observes government intervention to curtail a prostitution prevalent society. Various parameters and variables help to define and indicate the dynamics of pros- titution to construct viable simulations. Successful prostitution interaction prevention deemed essential in prostitution prevention; however, government intervention corresponding with successful rehabilitation competitively challenges prostitution interaction prevention in reducing basic reproductive values.
文摘This paper reports a study designed to observe how a learning community arose when a group of learners of English focused on a common project. The students' task was to participate as speakers in an international conference. Undergraduate students in a course of Business English at a small private university in western Mexico worked in teams to research and develop a topic to be sent as a proposal to the conference.The study used Interaction Analysis with a qualitative focus to observe participant interactions. Video and audio recordings were supplemented with participant interviews and questionnaires. Analysis shows that in the course of the project, the students learned not only business terminology, but also how to work together.
基金supported by the National Natural Science Foundation of ChinaSpecialized Research Fund for the Doctoral Program of Higher EducationSpecialized Fund for the Basic Research of Jilin University (20903045, 20573042, 20070183046,200810018)
文摘Kynurenine aminotransferases (KATs) catalyze the transamination of kynurenine (KYN) pathway and endogenous KYNs have been suggested to highly correlate to abnormal brain diseases. HKAT3 is a key member of KAT family, while the binding mechanism of KYN and cofactor with HKAT3 has not been determined yet. In this study, we focus on the structure-function relationship among KYN, cofactor and HKAT3. The binding models of KYN complex and KYN&cofactor complex were ob- tained and were studied by molecular dynamics (MD) simulations. We identified several critical residues and influence of conformational changes in human kynurenine aminotransferase 3 (HKAT3) complexes. The cofactor may contribute largely not only to the catalysis, but also to the binding. In addition, a hypothesis is proposed that a strong hydrophobic interaction between Tyr159 and Lys280 may influence the binding mode and the binding region of the substrate and the cofactor. Our re- suits will be a good starting point for further determination of the biological role.