Various steady models for interaction between heart and arterial system have been given in liter- ature,In our recent study,a dynamic principle,i.e.the principle of least cardiac work is proposed,and a dy- namic model...Various steady models for interaction between heart and arterial system have been given in liter- ature,In our recent study,a dynamic principle,i.e.the principle of least cardiac work is proposed,and a dy- namic model for interaction of heart and arterial system is established.Preliminary results of our experiments show that both the principle and the model are consistent with the physiological phenomena.It reveals that the pres- ent analysis may offer a new measure for the study of dynamic process of interaction between heart and arterial system.展开更多
Objective To evaluate the effects of environmental factors and microRNAs (miRNAs) (miR-126, miR-143, and miR-145) on the risk of coronary heart disease (CHD). Methods A frequency-matched case-control study (450...Objective To evaluate the effects of environmental factors and microRNAs (miRNAs) (miR-126, miR-143, and miR-145) on the risk of coronary heart disease (CHD). Methods A frequency-matched case-control study (450 patients, 450 controls) was conducted from April 2014 to December 2016 in Fuzhou City, China. Environmental factors were investigated using a self-administered questionnaire, and the expression levels of miR-126, rniR-143, and miR-145 were determined by quantitative real-time Polymerase Chain Reaction (PCR) in pe- ripheral blood mononuclear cells. Unconditional logistic regression models were used for statistical evaluation. Results Alcohol consumption, high-salt diets, high-intensity work, and lack of physical activity were significantly associated with increased CHD risk, whereas light diet was significantly associated with decreased risk. MiR-126, miR-143, and miR-145 were highly expressed in the CHD group compared with the control group. After adjustment for other environmental factors, unconditional logistic regression results revealed that miR-126, miR-143, and depression were the independent risk factors of CHD, and light diet was the independent protective factor of CHD. Conclusions Our data suggest that a family history of CHD, anxiety, and alcohol consumption was significantly associated with increased CHD risk, whereas light diet was significantly associated with decreased risk. Furthermore, miR-126 and miR-143 in combination with several risk factors, could play a joint role in the development of CHD. Therefore, it is necessary to manage patients with CHD in all directions and multiple level.展开更多
Oriental Beech is the most important commercial tree species in northern Iran. In recent years wood production companies interested in felling large beech trees for profit have challenged advocates of close-to-nature ...Oriental Beech is the most important commercial tree species in northern Iran. In recent years wood production companies interested in felling large beech trees for profit have challenged advocates of close-to-nature silviculture who favor conservation. Our study objective was to assess the economic value of over-mature beech trees by relating tree diameter (DBH) to amount of decay. Based on the location of onset of decay, we categorized three types of decay as stump, stem, and crown decay. Trees of greater diameter (age) typically showed greater decay in the stem. Percent of decayed volume, diameter of decayed tissue, and length of decay in tree stems varied between 0.5%-64.3%, 15 cm-75 cm, and 2.0-19.5 m, respectively. With increasing trunk diameter, the propor- tion of truck decay increased. Red heart and dark red heart constituted 25% and 14.3% of sampled trees, respectively. However, we found no correlation between intensity of stem decay and morphological charac- teristics of trees. Seedlings were not abundant around the bases of over-mature trees, suggesting that the trees did not contribute to regeneration of the stand. Beech trees of diameter 〉1 m do not provide valu- able round wood for industries and cause to raise wood production costs. We recommend that these trees 〉1 m DBH should be retained in forest stands because of their low commercial value but high ecological and conservational values such as maintaining biodiversity in forest ecosystems.展开更多
To study the Fe-M interactions and their effects on 31p NMR, the structures of Fe(CO)3(EtPhPpy)2 1, Fe(CO)3(EtPhPpy)2M(NCS)2 (2: M=Zn, 3: M=Cd, 4: M=Hg) and Fe(CO)3(EtPhPpy)2CdX2 (5: X=C1, 6: X=...To study the Fe-M interactions and their effects on 31p NMR, the structures of Fe(CO)3(EtPhPpy)2 1, Fe(CO)3(EtPhPpy)2M(NCS)2 (2: M=Zn, 3: M=Cd, 4: M=Hg) and Fe(CO)3(EtPhPpy)2CdX2 (5: X=C1, 6: X=SCN) were investigated by density functional theory (DFT) PBE0 method. The stabilities S of complexes follow S(2)〉S(3)〉S(4) and S(3),.~S(6)〉S(5), indicating that 6 is stable and may be synthesized. The complexes with thiocyanate are more stable than that with chloride in Fe(CO)3(EtPhPpy)2CdX2. The strength I of Fe-M interactions follows I(2)≈I(3)〈I(4). The Fe-Cd interactions of 3 and 6, which contain thiocyanate, are stronger than that of 5 with chloride. The charge-transfer, which enhances with the increasing of Fe-M interaction strength, comes from Et, Ph, py, CO groups towards P, Fe, and M atoms. Because the delocalization of thiocyanate disperses the charge of M2+, the charge-transfer of the complexes with thiocyanate is stronger than that with chloride. There is a a-bond between Fe and Hg atoms in 4. However, in binuclear complexes except 4, the Fe-M interactions act as nFe→nM, σP-Fe→nM and σC-Fe→nM delocalization, and the N-M interactions mainly act as nN→nM delocalization. In binuclear complexes, due to the Fe→M interactions, the strong σFe--C→σ*Fe--p or σFe-Hg→σ*Fe--I2 delocalization and the charge-transfer, the electron density on P nucleus is increased, and thus upfield 31p chemical shifts are caused (compared with mononuclear complex 1).展开更多
Objective: To investigate the correlation of serum ADAMTS-1 and ADAMTS-13 contents with plaque nature, inflammatory factors and adipocytokines in patients with coronary heart disease. Methods: A total of 106 patients ...Objective: To investigate the correlation of serum ADAMTS-1 and ADAMTS-13 contents with plaque nature, inflammatory factors and adipocytokines in patients with coronary heart disease. Methods: A total of 106 patients with coronary heart disease undergoing examination in the hospital between September 2014 and June 2017 were enrolled in coronary heart disease group, and 100 healthy volunteers were enrolled in normal control group. Differences in serum ADAMTS-1, ADAMTS-13, plaque nature-related index, inflammatory factor and adipocytokine contents were compared between the two groups. Pearson test was used to assess the correlation of ADAMTS-1 and ADAMTS-13 contents with plaque nature, inflammatory factor and adipocytokines in patients with coronary heart disease. Results: Serum ADAMTS-1 content of coronary heart disease group was higher than that of normal control group whereas ADAMTS-13 content was lower than that of normal control group;serum plaque nature-related indexes Hcy and UA contents were higher than those of normal control group;serum inflammatory factors HMGB1, IL-6, IL-8 and IL-18 contents were higher than those of normal control group;serum adipocytokines APN and Vaspin contents were lower than those of normal control group whereas Visfatin and RBP4 contents were higher than those of normal control group. Pearson test showed that serum ADAMTS-1 and ADAMTS-13 contents of patients with coronary heart disease were directly correlated with the contents of plaque nature-related indexes, inflammatory factors and adipocytokines. Conclusion: Serum ADAMTS-1 content abnormally increases and ADAMTS-13 content abnormally decreases in patients with coronary heart disease, and the specific contents are directly correlated with the condition of coronary heart disease.展开更多
Yossarian,the protagonist of Catch-22,lives in a marginal position and in the dilemma,and he has done many ridiculous things to keep alive.But basically Yossarian is still kind-hearted.He is an upright man and very co...Yossarian,the protagonist of Catch-22,lives in a marginal position and in the dilemma,and he has done many ridiculous things to keep alive.But basically Yossarian is still kind-hearted.He is an upright man and very compassionate to others.展开更多
A more natural way for non-expert users to express their tasks in an open-ended set is to use natural language. In this case,a human-centered intelligent agent/robot is required to be able to understand and generate p...A more natural way for non-expert users to express their tasks in an open-ended set is to use natural language. In this case,a human-centered intelligent agent/robot is required to be able to understand and generate plans for these naturally expressed tasks. For this purpose, it is a good way to enhance intelligent robot's abilities by utilizing open knowledge extracted from the web, instead of hand-coded knowledge. A key challenge of utilizing open knowledge lies in the semantic interpretation of the open knowledge organized in multiple modes, which can be unstructured or semi-structured, before one can use it.Previous approaches used a limited lexicon to employ combinatory categorial grammar(CCG) as the underlying formalism for semantic parsing over sentences. Here, we propose a more effective learning method to interpret semi-structured user instructions. Moreover, we present a new heuristic method to recover missing semantic information from the context of an instruction. Experiments showed that the proposed approach renders significant performance improvement compared to the baseline methods and the recovering method is promising.展开更多
Tetrazole monomers (Ⅰ, Ⅱ) and all of their possible stable dimers (1, 2, 3, 4, 5, 6, 7 and 8) were fully optimized by DFT method at the B3LYP/6-311++G^** level. Among the eight dimers, there were two 1H-tetr...Tetrazole monomers (Ⅰ, Ⅱ) and all of their possible stable dimers (1, 2, 3, 4, 5, 6, 7 and 8) were fully optimized by DFT method at the B3LYP/6-311++G^** level. Among the eight dimers, there were two 1H-tetrazole dimers, three 2H-tetrazole dimers and three hetero dimers of 1H-tetrazole and 2H-tetrazole. Vibrational frequencies were calculated to ascertain that each structure was stable (no imaginary frequencies). The basis set superposition errors (BSSE) are 2.78, 2.28, 2.97, 2.75, 2.74, 2.18, 1.23 and 3.10 kJ/mol, and the zero point energy (ZPE) corrections for the interaction energies are 4.88, 4.18, 3.87, 3.65, 3.54, 3.22, 2.87 and 4.34 kJ/mol for 1, 2, 3, 4, 5, 6, 7 and 8, respectively. After BSSE and ZPE corrections, the greatest corrected intermolecular interaction energy of the dimers is -43.71 kJ/mol. The charge redistribution mainly occurs on the adjacent N-H…N atoms between submolecules. The charge transfer between two subsystems is very small. Natural bond orbital (NBO) analysis was performed to reveal the origin of the interaction. Based on the statistical thermodynamic method, the standard thermodynamic functions, heat capacities (C^0P), entropies (S^0T) and thermal corrections to enthalpy (H^0T), and the changes of thermodynamic properties from monomer to dimer in the temperature range of 200.00 K to 700 K have been obtained. 1H-tetrazole monomer can spontaneously turn into two stable dimers at 298.15 K.展开更多
Interaction between mothers and midwives during natural childbirth is one of the important factors in relationship between mothers and midwives in natural childbirth. In this qualitative study we explored experiences ...Interaction between mothers and midwives during natural childbirth is one of the important factors in relationship between mothers and midwives in natural childbirth. In this qualitative study we explored experiences of mothers and midwives in interaction with each other in natural childbirth. This study was a part of a larger study which was carried out in Iran in 2013-2014. A total of 23 participants participated in this study. 12 primiparous and multiparous women planned to have natural deliveries and 11 midwives were purposefully included for semi-structured in-depth interviews in this study. For analysis and interpretation of mothers’ and midwives’ experience, conventional content analysis was used. Data were coded in MAXqda software (version 2). Interaction between mothers and midwives could be organized and categorized in one theme “relationship”. This theme consists of two subthemes: “respect for the mother” and “interaction” and five categories: “Feeling confidence, Feeling satisfaction, Associated with sensory relationship, Understanding mother’s situation, Understanding the meaning of interaction”. Good relationship between mothers and midwives in natural childbirth could improve the experience of natural childbirth for mothers. This experience could increase woman’s tendency toward natural birth instead of cesarean section in future pregnancies. Findings of this study can be seen as a challenge for health care professionals and policy makers to upgrade care of natural childbirth based on women’s preferences and needs.展开更多
To study the effect of guide vane outlet angle on pump performance and impeller radial force in an axial-flow heart pump, guide vane outlet angle/34 is considered to be 20°, 15°, 10°, 5° and 3°...To study the effect of guide vane outlet angle on pump performance and impeller radial force in an axial-flow heart pump, guide vane outlet angle/34 is considered to be 20°, 15°, 10°, 5° and 3° respectively. Based on ANSYS Fluent, numerical results of pump head and efficiency are validated by exper/ment results, in which Xanthan gum solutions are used with concentration of 0.06 wt. % as working fluid. Then, the effects of/34 on pump performance and impeller radial force are discussed, the errors of head and efficiency between test and simulation are within 5%. The results a/so indicate that the pump performance and efficiency are much better than those of other angles when guide vane outlet angle/34 is 10°, and the maximum variations in head and efficiency are 1.9% and 2.2%, respectively. With/34 increasing, the pulsation of radial force decreases firstly and then increases, when/34 is 10°, the minimum pulsation is 0. 0392N, which is about 80% of the maximum pulsation amplitude.展开更多
In this study,we use the extended finite element method(XFEM)with a consideration of junction enrichment functions to investigate the mechanics of hydraulic fractures related to naturally cemented fractures.In the pro...In this study,we use the extended finite element method(XFEM)with a consideration of junction enrichment functions to investigate the mechanics of hydraulic fractures related to naturally cemented fractures.In the proposed numerical model,the lubrication equation is adopted to describe the fluid flow within fractures.The fluid-solid coupling systems of the hydraulic fracturing problem are solved using the Newton-Raphson method.The energy release rate criterion is used to determine the cross/arrest behavior between a hydraulic fracture(HF)and a cemented natural fracture(NF).The failure patterns and mechanisms of crack propagation at the intersection of natural fractures are discussed.Simulation results show that after crossing an NF,the failure mode along the cemented NF path may change from the tensile regime to the shear or mixed-mode regime.When an advancing HF kinks back toward the matrix,the failure mode may gradually switch back to the tensile-dominated regime.Key factors,including the length of the upper/lower portion of the cemented NF,horizontal stress anisotropy,and the intersection angle of the crack propagation are investigated in detail.An uncemented or partially cemented NF will form a more complex fracture network than a cemented NF.This study provides insight into the formation mechanism of fracture networks in formations that contain cemented NF.展开更多
Nowadays,several studies demonstrate that viewing nature has positive effects on human health and well-being.This essay discusses about the essential methods of viewing natural environment and their impacts on human w...Nowadays,several studies demonstrate that viewing nature has positive effects on human health and well-being.This essay discusses about the essential methods of viewing natural environment and their impacts on human well-being by clarifying four important theoretical models:reducing stress,lowering heart rate,improving outcome of surgery,and increasing attention.In addition,some important research results in this field are taken as examples to introduce research methods.By collecting and organizing existing studies and theories about the relationship between viewing nature and human well-being,the methods of viewing nature can be divided into two parts:viewing nature through specific media(e.g.,through a window,a book,a painting or a videotape)and being with the presence of nature.This study aims to clarify the research significance of viewing nature and find deficiency in this field to maximize the role of landscapes in human health and well-being.展开更多
The cause-effect associations between geographical phenomena are an important focus in ecological research. Recent studies in structural equation modeling(SEM) demonstrated the potential for analyzing such associati...The cause-effect associations between geographical phenomena are an important focus in ecological research. Recent studies in structural equation modeling(SEM) demonstrated the potential for analyzing such associations. We applied the variance-based partial least squares SEM(PLS-SEM) and geographically-weighted regression(GWR) modeling to assess the human-climate impact on grassland productivity represented by above-ground biomass(AGB). The human and climate factors and their interaction were taken to explain the AGB variance by a PLS-SEM developed for the grassland ecosystem in Inner Mongolia, China. Results indicated that 65.5% of the AGB variance could be explained by the human and climate factors and their interaction. The case study showed that the human and climate factors imposed a significant and negative impact on the AGB and that their interaction alleviated to some extent the threat from the intensified human-climate pressure. The alleviation may be attributable to vegetation adaptation to high human-climate stresses, to human adaptation to climate conditions or/and to recent vegetation restoration programs in the highly degraded areas. Furthermore, the AGB response to the human and climate factors modeled by GWR exhibited significant spatial variations. This study demonstrated that the combination of PLS-SEM and GWR model is feasible to investigate the cause-effect relation in socio-ecological systems.展开更多
Covalent bonds arise from the overlap of the electronic clouds in the internucleus region, which is a pure quantum effect and cannot be obtained in any classical way. If the intermolecular interaction is of covalent c...Covalent bonds arise from the overlap of the electronic clouds in the internucleus region, which is a pure quantum effect and cannot be obtained in any classical way. If the intermolecular interaction is of covalent character, the result from direct applications of classical simulation methods to the molecular system would be questionable. Here, we analyze the special intermolecular interaction between two NO molecules based on quantum chemical calculation. This weak intermolecular interaction, which is of covalent character, is responsible for the formation of the NO dimer,(NO)2, in its most stable conformation, a cis conformation. The natural bond orbital(NBO) analysis gives an intuitive illustration of the formation of the dimer bonding and antibonding orbitals concomitant with the breaking of the πbonds with bond order 0.5of the monomers. The dimer bonding is counteracted by partially filling the antibonding dimer orbital and the repulsion between those fully or nearly fully occupied nonbonding dimer orbitals that make the dimer binding rather weak. The direct molecular mechanics(MM) calculation with the UFF force fields predicts a trans conformation as the most stable state, which contradicts the result of quantum mechanics(QM). The lesson from the investigation of this special system is that for the case where intermolecular interaction is of covalent character, a specific modification of the force fields of the molecular simulation method is necessary.展开更多
The philosophy of heart and brain are very ancient in our literature where the things good for the heart are not suggested good for the brain and vice-versa.Modern medicine is characterized by a high degree of special...The philosophy of heart and brain are very ancient in our literature where the things good for the heart are not suggested good for the brain and vice-versa.Modern medicine is characterized by a high degree of specialization and the heart-brain connection that could be targeted to treat these complex cardiovascular/brain disorders.The idea that adverse diet/genome interactions can cause disease is not new.In the recent era the science of nutritional genomics have increased our understanding of diet-health-gene interactions and have provided a number of benefits for individuals,groups and societies.Since dietary chemicals are regularly ingested and participate indirectly and directly in regulating gene expression,it follows that a subset of genes regulated by diet must be involved in disease initiation,progression,and severity.In this regards Liver X Receptor(LXR)-a,a key transcription factors,associated with the several chronic pathological situation including coronary heart disease and neurodegenerative diseases have recently been found to be regulated by the dietary components.The crucial findings at molecular biology unit,Post Graduate Institute of Medical Education and Research(PGIMER),Chandigarh,INDIA have not only forced us to explore nutritional genomics as a holistic systems approach to understand the relationship between diet and health,but also to look into the disease preventing and health promoting foods that match our lifestyles,cultures and genetics.After all,we are what we eat.展开更多
Summary: In the experimental study on the electrophysiology and functions of heart in the animal, the thorax should be opened to expose the heart, at the same time natural breathing is maintained instead of artificial...Summary: In the experimental study on the electrophysiology and functions of heart in the animal, the thorax should be opened to expose the heart, at the same time natural breathing is maintained instead of artificial breathing. The key procedure of this new method is to avoid injuring the pleural cavity, so pneumothorax can be prevented. By means of this new method some subject studies have been finished.展开更多
Magnetotactic bacteria optimization algorithm (MBOA) is a new optimization algorithm inspired by the characteristics of magnetotactic bacteria, which is a kind of polyphyletic group of prokaryotes with the characteris...Magnetotactic bacteria optimization algorithm (MBOA) is a new optimization algorithm inspired by the characteristics of magnetotactic bacteria, which is a kind of polyphyletic group of prokaryotes with the characteristics of magnetotaxis that make them orient and swim along geomagnetic field lines. The original Magnetotactic Bacteria Optimization Algorithm (MBOA) and several new variants of MBOA mimics the interaction energy between magnetosomes chains to obtain moments for solving problems. In this paper, Magnetotactic Bacteria Optimization Algorithm with the Best Individual-guided Differential Interaction Energy (MBOA-BIDE) is proposed. We improved interaction energy calculation by using the best individual-guided?differential interaction energy formation. We focus on analyzing the performance of different parameters settings. The experiment results show that the proposed algorithm is sensitive to parameters settings on some functions.展开更多
Being a patient in a strange and unknown environment is sometimes very stressful. Research has shown that a healthpromoting environment can reduce anxiety and enhance wellbeing and views of nature can support this. Th...Being a patient in a strange and unknown environment is sometimes very stressful. Research has shown that a healthpromoting environment can reduce anxiety and enhance wellbeing and views of nature can support this. This low-cost intervention wasperformed at a heart surgery intensive care unit.The aim was to use a simple method to improve the health care environment and tomonitor the experiences of patients and staf~ Two patients share the same room at the 1CU. The beds can be separated by roller shadesthat are plain grey and neutral. These were changed to new ones with nature motives. Questionnaires with fixed and open questionswere used for evaluation among patients and staff. Patients treated in an ICU seem to be aware of the surrounding environment even ifthey are severely ill. Both patients and staff stated that the roller shades with motive affected wellbeing in a positive way. An estheticalpleasing environment can contribute to wellbeing even if the effort is small and insignificant. Roller shades with nature motive might bean easy way to improve and strengthen a health promoting environment.展开更多
Heart of Darkness is one of the masterpieces of Joseph Conrad (1857-1924), which shows the author's great humanity and his unreserved horror at the crimes committed by the colonists and imperialists all over the wo...Heart of Darkness is one of the masterpieces of Joseph Conrad (1857-1924), which shows the author's great humanity and his unreserved horror at the crimes committed by the colonists and imperialists all over the world. This thesis tries to analyze its three themes: the Colonists' material essence, the dark side of human nature, and the disillusionment of civilization. Kurtz, the main character in the novel, is characterized by his greed for material gain and power. The dark side of human nature is reflected in Kurtz's cruel behavior towards the natives, his sense of superiority to the marginalized, and his dominance in discourse over the colonial people. Along with the colonists' crazy behaviors, there is disillusion with the modem civilization.展开更多
文摘Various steady models for interaction between heart and arterial system have been given in liter- ature,In our recent study,a dynamic principle,i.e.the principle of least cardiac work is proposed,and a dy- namic model for interaction of heart and arterial system is established.Preliminary results of our experiments show that both the principle and the model are consistent with the physiological phenomena.It reveals that the pres- ent analysis may offer a new measure for the study of dynamic process of interaction between heart and arterial system.
文摘Objective To evaluate the effects of environmental factors and microRNAs (miRNAs) (miR-126, miR-143, and miR-145) on the risk of coronary heart disease (CHD). Methods A frequency-matched case-control study (450 patients, 450 controls) was conducted from April 2014 to December 2016 in Fuzhou City, China. Environmental factors were investigated using a self-administered questionnaire, and the expression levels of miR-126, rniR-143, and miR-145 were determined by quantitative real-time Polymerase Chain Reaction (PCR) in pe- ripheral blood mononuclear cells. Unconditional logistic regression models were used for statistical evaluation. Results Alcohol consumption, high-salt diets, high-intensity work, and lack of physical activity were significantly associated with increased CHD risk, whereas light diet was significantly associated with decreased risk. MiR-126, miR-143, and miR-145 were highly expressed in the CHD group compared with the control group. After adjustment for other environmental factors, unconditional logistic regression results revealed that miR-126, miR-143, and depression were the independent risk factors of CHD, and light diet was the independent protective factor of CHD. Conclusions Our data suggest that a family history of CHD, anxiety, and alcohol consumption was significantly associated with increased CHD risk, whereas light diet was significantly associated with decreased risk. Furthermore, miR-126 and miR-143 in combination with several risk factors, could play a joint role in the development of CHD. Therefore, it is necessary to manage patients with CHD in all directions and multiple level.
文摘Oriental Beech is the most important commercial tree species in northern Iran. In recent years wood production companies interested in felling large beech trees for profit have challenged advocates of close-to-nature silviculture who favor conservation. Our study objective was to assess the economic value of over-mature beech trees by relating tree diameter (DBH) to amount of decay. Based on the location of onset of decay, we categorized three types of decay as stump, stem, and crown decay. Trees of greater diameter (age) typically showed greater decay in the stem. Percent of decayed volume, diameter of decayed tissue, and length of decay in tree stems varied between 0.5%-64.3%, 15 cm-75 cm, and 2.0-19.5 m, respectively. With increasing trunk diameter, the propor- tion of truck decay increased. Red heart and dark red heart constituted 25% and 14.3% of sampled trees, respectively. However, we found no correlation between intensity of stem decay and morphological charac- teristics of trees. Seedlings were not abundant around the bases of over-mature trees, suggesting that the trees did not contribute to regeneration of the stand. Beech trees of diameter 〉1 m do not provide valu- able round wood for industries and cause to raise wood production costs. We recommend that these trees 〉1 m DBH should be retained in forest stands because of their low commercial value but high ecological and conservational values such as maintaining biodiversity in forest ecosystems.
基金This work was supported by the Natural Science Foundation of Guangdong Province (No.5005938) and the Research Project of Ministry of Education and Guangdong Province (No.2007A090302046).
文摘To study the Fe-M interactions and their effects on 31p NMR, the structures of Fe(CO)3(EtPhPpy)2 1, Fe(CO)3(EtPhPpy)2M(NCS)2 (2: M=Zn, 3: M=Cd, 4: M=Hg) and Fe(CO)3(EtPhPpy)2CdX2 (5: X=C1, 6: X=SCN) were investigated by density functional theory (DFT) PBE0 method. The stabilities S of complexes follow S(2)〉S(3)〉S(4) and S(3),.~S(6)〉S(5), indicating that 6 is stable and may be synthesized. The complexes with thiocyanate are more stable than that with chloride in Fe(CO)3(EtPhPpy)2CdX2. The strength I of Fe-M interactions follows I(2)≈I(3)〈I(4). The Fe-Cd interactions of 3 and 6, which contain thiocyanate, are stronger than that of 5 with chloride. The charge-transfer, which enhances with the increasing of Fe-M interaction strength, comes from Et, Ph, py, CO groups towards P, Fe, and M atoms. Because the delocalization of thiocyanate disperses the charge of M2+, the charge-transfer of the complexes with thiocyanate is stronger than that with chloride. There is a a-bond between Fe and Hg atoms in 4. However, in binuclear complexes except 4, the Fe-M interactions act as nFe→nM, σP-Fe→nM and σC-Fe→nM delocalization, and the N-M interactions mainly act as nN→nM delocalization. In binuclear complexes, due to the Fe→M interactions, the strong σFe--C→σ*Fe--p or σFe-Hg→σ*Fe--I2 delocalization and the charge-transfer, the electron density on P nucleus is increased, and thus upfield 31p chemical shifts are caused (compared with mononuclear complex 1).
文摘Objective: To investigate the correlation of serum ADAMTS-1 and ADAMTS-13 contents with plaque nature, inflammatory factors and adipocytokines in patients with coronary heart disease. Methods: A total of 106 patients with coronary heart disease undergoing examination in the hospital between September 2014 and June 2017 were enrolled in coronary heart disease group, and 100 healthy volunteers were enrolled in normal control group. Differences in serum ADAMTS-1, ADAMTS-13, plaque nature-related index, inflammatory factor and adipocytokine contents were compared between the two groups. Pearson test was used to assess the correlation of ADAMTS-1 and ADAMTS-13 contents with plaque nature, inflammatory factor and adipocytokines in patients with coronary heart disease. Results: Serum ADAMTS-1 content of coronary heart disease group was higher than that of normal control group whereas ADAMTS-13 content was lower than that of normal control group;serum plaque nature-related indexes Hcy and UA contents were higher than those of normal control group;serum inflammatory factors HMGB1, IL-6, IL-8 and IL-18 contents were higher than those of normal control group;serum adipocytokines APN and Vaspin contents were lower than those of normal control group whereas Visfatin and RBP4 contents were higher than those of normal control group. Pearson test showed that serum ADAMTS-1 and ADAMTS-13 contents of patients with coronary heart disease were directly correlated with the contents of plaque nature-related indexes, inflammatory factors and adipocytokines. Conclusion: Serum ADAMTS-1 content abnormally increases and ADAMTS-13 content abnormally decreases in patients with coronary heart disease, and the specific contents are directly correlated with the condition of coronary heart disease.
文摘Yossarian,the protagonist of Catch-22,lives in a marginal position and in the dilemma,and he has done many ridiculous things to keep alive.But basically Yossarian is still kind-hearted.He is an upright man and very compassionate to others.
基金supported by the National Natural Science Foundation of China(61175057)the USTC Key-Direction Research Fund(WK0110000028)
文摘A more natural way for non-expert users to express their tasks in an open-ended set is to use natural language. In this case,a human-centered intelligent agent/robot is required to be able to understand and generate plans for these naturally expressed tasks. For this purpose, it is a good way to enhance intelligent robot's abilities by utilizing open knowledge extracted from the web, instead of hand-coded knowledge. A key challenge of utilizing open knowledge lies in the semantic interpretation of the open knowledge organized in multiple modes, which can be unstructured or semi-structured, before one can use it.Previous approaches used a limited lexicon to employ combinatory categorial grammar(CCG) as the underlying formalism for semantic parsing over sentences. Here, we propose a more effective learning method to interpret semi-structured user instructions. Moreover, we present a new heuristic method to recover missing semantic information from the context of an instruction. Experiments showed that the proposed approach renders significant performance improvement compared to the baseline methods and the recovering method is promising.
文摘Tetrazole monomers (Ⅰ, Ⅱ) and all of their possible stable dimers (1, 2, 3, 4, 5, 6, 7 and 8) were fully optimized by DFT method at the B3LYP/6-311++G^** level. Among the eight dimers, there were two 1H-tetrazole dimers, three 2H-tetrazole dimers and three hetero dimers of 1H-tetrazole and 2H-tetrazole. Vibrational frequencies were calculated to ascertain that each structure was stable (no imaginary frequencies). The basis set superposition errors (BSSE) are 2.78, 2.28, 2.97, 2.75, 2.74, 2.18, 1.23 and 3.10 kJ/mol, and the zero point energy (ZPE) corrections for the interaction energies are 4.88, 4.18, 3.87, 3.65, 3.54, 3.22, 2.87 and 4.34 kJ/mol for 1, 2, 3, 4, 5, 6, 7 and 8, respectively. After BSSE and ZPE corrections, the greatest corrected intermolecular interaction energy of the dimers is -43.71 kJ/mol. The charge redistribution mainly occurs on the adjacent N-H…N atoms between submolecules. The charge transfer between two subsystems is very small. Natural bond orbital (NBO) analysis was performed to reveal the origin of the interaction. Based on the statistical thermodynamic method, the standard thermodynamic functions, heat capacities (C^0P), entropies (S^0T) and thermal corrections to enthalpy (H^0T), and the changes of thermodynamic properties from monomer to dimer in the temperature range of 200.00 K to 700 K have been obtained. 1H-tetrazole monomer can spontaneously turn into two stable dimers at 298.15 K.
文摘Interaction between mothers and midwives during natural childbirth is one of the important factors in relationship between mothers and midwives in natural childbirth. In this qualitative study we explored experiences of mothers and midwives in interaction with each other in natural childbirth. This study was a part of a larger study which was carried out in Iran in 2013-2014. A total of 23 participants participated in this study. 12 primiparous and multiparous women planned to have natural deliveries and 11 midwives were purposefully included for semi-structured in-depth interviews in this study. For analysis and interpretation of mothers’ and midwives’ experience, conventional content analysis was used. Data were coded in MAXqda software (version 2). Interaction between mothers and midwives could be organized and categorized in one theme “relationship”. This theme consists of two subthemes: “respect for the mother” and “interaction” and five categories: “Feeling confidence, Feeling satisfaction, Associated with sensory relationship, Understanding mother’s situation, Understanding the meaning of interaction”. Good relationship between mothers and midwives in natural childbirth could improve the experience of natural childbirth for mothers. This experience could increase woman’s tendency toward natural birth instead of cesarean section in future pregnancies. Findings of this study can be seen as a challenge for health care professionals and policy makers to upgrade care of natural childbirth based on women’s preferences and needs.
基金Supported by the National Natural Science Foundation of China(No.51574161)the Education Science Project of Young and Middle-aged Teachers of Universities in Fujian Province(No.JZ160396)
文摘To study the effect of guide vane outlet angle on pump performance and impeller radial force in an axial-flow heart pump, guide vane outlet angle/34 is considered to be 20°, 15°, 10°, 5° and 3° respectively. Based on ANSYS Fluent, numerical results of pump head and efficiency are validated by exper/ment results, in which Xanthan gum solutions are used with concentration of 0.06 wt. % as working fluid. Then, the effects of/34 on pump performance and impeller radial force are discussed, the errors of head and efficiency between test and simulation are within 5%. The results a/so indicate that the pump performance and efficiency are much better than those of other angles when guide vane outlet angle/34 is 10°, and the maximum variations in head and efficiency are 1.9% and 2.2%, respectively. With/34 increasing, the pulsation of radial force decreases firstly and then increases, when/34 is 10°, the minimum pulsation is 0. 0392N, which is about 80% of the maximum pulsation amplitude.
基金financially supported by the National Science Foundation of China(Grant Nos.51804033 and 51936001)Natural Science Foundation of Jiangsu Province(Grant No.BK20170457)+3 种基金Program of Great Wall Scholar(Grant No.CIT&TCD20180313)Jointly Projects of Beijing Natural Science FoundationBeijing Municipal Education Commission(Grant No.KZ201810017023)Beijing Youth Talent Support Program(CIT&TCD201804037).
文摘In this study,we use the extended finite element method(XFEM)with a consideration of junction enrichment functions to investigate the mechanics of hydraulic fractures related to naturally cemented fractures.In the proposed numerical model,the lubrication equation is adopted to describe the fluid flow within fractures.The fluid-solid coupling systems of the hydraulic fracturing problem are solved using the Newton-Raphson method.The energy release rate criterion is used to determine the cross/arrest behavior between a hydraulic fracture(HF)and a cemented natural fracture(NF).The failure patterns and mechanisms of crack propagation at the intersection of natural fractures are discussed.Simulation results show that after crossing an NF,the failure mode along the cemented NF path may change from the tensile regime to the shear or mixed-mode regime.When an advancing HF kinks back toward the matrix,the failure mode may gradually switch back to the tensile-dominated regime.Key factors,including the length of the upper/lower portion of the cemented NF,horizontal stress anisotropy,and the intersection angle of the crack propagation are investigated in detail.An uncemented or partially cemented NF will form a more complex fracture network than a cemented NF.This study provides insight into the formation mechanism of fracture networks in formations that contain cemented NF.
文摘Nowadays,several studies demonstrate that viewing nature has positive effects on human health and well-being.This essay discusses about the essential methods of viewing natural environment and their impacts on human well-being by clarifying four important theoretical models:reducing stress,lowering heart rate,improving outcome of surgery,and increasing attention.In addition,some important research results in this field are taken as examples to introduce research methods.By collecting and organizing existing studies and theories about the relationship between viewing nature and human well-being,the methods of viewing nature can be divided into two parts:viewing nature through specific media(e.g.,through a window,a book,a painting or a videotape)and being with the presence of nature.This study aims to clarify the research significance of viewing nature and find deficiency in this field to maximize the role of landscapes in human health and well-being.
基金supported by the National Natural Science Foundation of China (41371371)the Strategic Priority Research Program of the Chinese Academy of Sciences (XDA05050402)
文摘The cause-effect associations between geographical phenomena are an important focus in ecological research. Recent studies in structural equation modeling(SEM) demonstrated the potential for analyzing such associations. We applied the variance-based partial least squares SEM(PLS-SEM) and geographically-weighted regression(GWR) modeling to assess the human-climate impact on grassland productivity represented by above-ground biomass(AGB). The human and climate factors and their interaction were taken to explain the AGB variance by a PLS-SEM developed for the grassland ecosystem in Inner Mongolia, China. Results indicated that 65.5% of the AGB variance could be explained by the human and climate factors and their interaction. The case study showed that the human and climate factors imposed a significant and negative impact on the AGB and that their interaction alleviated to some extent the threat from the intensified human-climate pressure. The alleviation may be attributable to vegetation adaptation to high human-climate stresses, to human adaptation to climate conditions or/and to recent vegetation restoration programs in the highly degraded areas. Furthermore, the AGB response to the human and climate factors modeled by GWR exhibited significant spatial variations. This study demonstrated that the combination of PLS-SEM and GWR model is feasible to investigate the cause-effect relation in socio-ecological systems.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.90403007 and 10975044)the Key Subject Construction Project of Hebei Provincial Universities,China+2 种基金the Research Project of Hebei Education Department,China(Grant Nos.Z2012067 and Z2011133)the National Natural Science Foundation of China(Grant No.11147103)the Open Project Program of State Key Laboratory of Theoretical Physics,Institute of Theoretical Physics,Chinese Academy of Sciences,China(Grant No.Y5KF211CJ1)
文摘Covalent bonds arise from the overlap of the electronic clouds in the internucleus region, which is a pure quantum effect and cannot be obtained in any classical way. If the intermolecular interaction is of covalent character, the result from direct applications of classical simulation methods to the molecular system would be questionable. Here, we analyze the special intermolecular interaction between two NO molecules based on quantum chemical calculation. This weak intermolecular interaction, which is of covalent character, is responsible for the formation of the NO dimer,(NO)2, in its most stable conformation, a cis conformation. The natural bond orbital(NBO) analysis gives an intuitive illustration of the formation of the dimer bonding and antibonding orbitals concomitant with the breaking of the πbonds with bond order 0.5of the monomers. The dimer bonding is counteracted by partially filling the antibonding dimer orbital and the repulsion between those fully or nearly fully occupied nonbonding dimer orbitals that make the dimer binding rather weak. The direct molecular mechanics(MM) calculation with the UFF force fields predicts a trans conformation as the most stable state, which contradicts the result of quantum mechanics(QM). The lesson from the investigation of this special system is that for the case where intermolecular interaction is of covalent character, a specific modification of the force fields of the molecular simulation method is necessary.
文摘The philosophy of heart and brain are very ancient in our literature where the things good for the heart are not suggested good for the brain and vice-versa.Modern medicine is characterized by a high degree of specialization and the heart-brain connection that could be targeted to treat these complex cardiovascular/brain disorders.The idea that adverse diet/genome interactions can cause disease is not new.In the recent era the science of nutritional genomics have increased our understanding of diet-health-gene interactions and have provided a number of benefits for individuals,groups and societies.Since dietary chemicals are regularly ingested and participate indirectly and directly in regulating gene expression,it follows that a subset of genes regulated by diet must be involved in disease initiation,progression,and severity.In this regards Liver X Receptor(LXR)-a,a key transcription factors,associated with the several chronic pathological situation including coronary heart disease and neurodegenerative diseases have recently been found to be regulated by the dietary components.The crucial findings at molecular biology unit,Post Graduate Institute of Medical Education and Research(PGIMER),Chandigarh,INDIA have not only forced us to explore nutritional genomics as a holistic systems approach to understand the relationship between diet and health,but also to look into the disease preventing and health promoting foods that match our lifestyles,cultures and genetics.After all,we are what we eat.
文摘Summary: In the experimental study on the electrophysiology and functions of heart in the animal, the thorax should be opened to expose the heart, at the same time natural breathing is maintained instead of artificial breathing. The key procedure of this new method is to avoid injuring the pleural cavity, so pneumothorax can be prevented. By means of this new method some subject studies have been finished.
文摘Magnetotactic bacteria optimization algorithm (MBOA) is a new optimization algorithm inspired by the characteristics of magnetotactic bacteria, which is a kind of polyphyletic group of prokaryotes with the characteristics of magnetotaxis that make them orient and swim along geomagnetic field lines. The original Magnetotactic Bacteria Optimization Algorithm (MBOA) and several new variants of MBOA mimics the interaction energy between magnetosomes chains to obtain moments for solving problems. In this paper, Magnetotactic Bacteria Optimization Algorithm with the Best Individual-guided Differential Interaction Energy (MBOA-BIDE) is proposed. We improved interaction energy calculation by using the best individual-guided?differential interaction energy formation. We focus on analyzing the performance of different parameters settings. The experiment results show that the proposed algorithm is sensitive to parameters settings on some functions.
文摘Being a patient in a strange and unknown environment is sometimes very stressful. Research has shown that a healthpromoting environment can reduce anxiety and enhance wellbeing and views of nature can support this. This low-cost intervention wasperformed at a heart surgery intensive care unit.The aim was to use a simple method to improve the health care environment and tomonitor the experiences of patients and staf~ Two patients share the same room at the 1CU. The beds can be separated by roller shadesthat are plain grey and neutral. These were changed to new ones with nature motives. Questionnaires with fixed and open questionswere used for evaluation among patients and staff. Patients treated in an ICU seem to be aware of the surrounding environment even ifthey are severely ill. Both patients and staff stated that the roller shades with motive affected wellbeing in a positive way. An estheticalpleasing environment can contribute to wellbeing even if the effort is small and insignificant. Roller shades with nature motive might bean easy way to improve and strengthen a health promoting environment.
文摘Heart of Darkness is one of the masterpieces of Joseph Conrad (1857-1924), which shows the author's great humanity and his unreserved horror at the crimes committed by the colonists and imperialists all over the world. This thesis tries to analyze its three themes: the Colonists' material essence, the dark side of human nature, and the disillusionment of civilization. Kurtz, the main character in the novel, is characterized by his greed for material gain and power. The dark side of human nature is reflected in Kurtz's cruel behavior towards the natives, his sense of superiority to the marginalized, and his dominance in discourse over the colonial people. Along with the colonists' crazy behaviors, there is disillusion with the modem civilization.