目的:探讨Pentacam眼前节分析仪和Keratron Scout角膜地形图仪测量Kappa角的一致性,评价两种仪器测量结果的重复性。方法:前瞻性随机对照研究。选取2018-01-01/30在我院眼视光中心行近视术前检查的患者69例,所有受试者由同一检查者分别...目的:探讨Pentacam眼前节分析仪和Keratron Scout角膜地形图仪测量Kappa角的一致性,评价两种仪器测量结果的重复性。方法:前瞻性随机对照研究。选取2018-01-01/30在我院眼视光中心行近视术前检查的患者69例,所有受试者由同一检查者分别采用Pentacam和Keratron Scout重复测量3次,以(X ,Y)坐标形式记录Kappa角的大小,采用组内相关系数(ICC)、Cronbach s Alpha系数评价两种仪器测量Kappa角的重复性;t 检验比较两种仪器测量结果的差异,Pearson相关分析其相关性;Bland-Altman图评估两种仪器测量结果的一致性。结果:3次重复测量时,两种仪器均表现出很好的重复性,两种仪器测得Kappa角差异无统计学意义( X 值: P =0.17;Y 值: P =0.61),Pearson相关分析表明Kappa角大小具有相关性(X 值: r =0.90, P <0.01;Y 值: r =0.91, P <0.01)。Bland-Altman图显示 X 值和 Y 值95%一致性区间分别为-0.11~0.14mm和-0.10~0.11mm。结论:Pentacam眼前节分析仪和Keratron Scout角膜地形图仪测量角膜屈光手术患者Kappa角重复性好,两种仪器测量的Kappa角结果一致性好,可以相互验证。展开更多
Lithosphere extension and upwelling of asthenosphere at post-collisional stage of an orogenic cycle generally induce diverse magmatism and/or associated high-temperature metamorphism. Nevertheless, the intimate coexis...Lithosphere extension and upwelling of asthenosphere at post-collisional stage of an orogenic cycle generally induce diverse magmatism and/or associated high-temperature metamorphism. Nevertheless, the intimate coexistence of post-collisional magmatic activity and high-temperature metamorphism is rare.In this contribution, a lithological assemblage composing of diverse magmatic rocks deriving from distinct magma sources and coeval high-temperature metamorphism was identified in eastern Kunlun.Petrography, ages, mineral chemistry and whole-rock geochemistry demonstrated that those intimately coexistent diverse rocks were genetically related to post-collisional extension. The garnet-bearing mafic granulites in Jinshuikou area interior of the East Kunlun Orogenic Belt are mainly composed of garnet,orthopyroxene, and plagioclase, with peak metamorphic P–T conditions of ~ 701–756 ℃and 5.6–7.0 kbar,representing a granulite-facies metamorphism at 409.7 ± 1.7 Ma. The diverse contemporaneous magmatic rocks including hornblendites, gabbros and granites yield zircon U–Pb ages of 408.6 ± 2.5 Ma,413.4 ± 4.6 Ma, and 387–407 Ma, respectively. The hornblendites show N-MORB-like REE patterns with(La/Sm)Nvalues of 0.85–0.94. They have positive zircon εHf(t) values of 0.1–4.9 and whole-rock εNd(t) values of 3.9–4.7 but relatively high(^(87)Sr/^(86)Sr)_(i)values of 0.7081 to 0.7088. These features demonstrate that the hornblendites derived from a depleted asthenospheric mantle source with minor continental crustal materials in source. As for the gabbros, they exhibit arc-like elemental signatures, low zircon εHf(t) values(-4.3 to 2.5) and variable whole-rock εNd(t) values(-4.9 to 1.2) as well as high(^(87)Sr/86 Sr)ivalues(0.7068 to 0.7126), arguing for that they were originated from partial melting of heterogeneous lithospheric mantle anteriorly metasomatized by subducted-sediment released melts. Geochemistry of the granites defines their strongly peraluminous S-type signatures. Zircons from the granites yield a large range of εHf(t) values ranging from -30.8 to -5.1, while the whole-rock samples yield consistent(^(87)Sr/86 Sr)ivalues(0.7301 to 0.7342) and negative εNd(t) values(-10.1 to -12.4). These features indicate that the S-type granites could be generated by reworking of an ancient crust. Taken together, the penecontemporaneous magmatism and metamorphic event, demonstrated the early-middle Devonian transition from crustal thickening to extensional collapse. The post-collisional mantle-derived magmas serve as an essential driving force for the high-temperature granulite-facies metamorphism and anataxis of the crust associated with formation of S-type granite. This study not only constructs a more detail Proto-Tethys evolution process of the eastern Kunlun, but also sheds new light on better understanding the intimate relationship between magmatism and metamorphism during post-collisional extensional collapse.展开更多
Cationic antimicrobial peptides (AMPs) are considered as important candidate therapeutic agents, which exert potent microbicidal properties against bacteria, fungi and some viruses. Based on our previous findings ki...Cationic antimicrobial peptides (AMPs) are considered as important candidate therapeutic agents, which exert potent microbicidal properties against bacteria, fungi and some viruses. Based on our previous findings king cobra cathelicidin (OH-CATH) is a 34-amino acid peptide that exerts strong antibacterial and weak hemolytic activity. The aim of this research is to evaluate the efficacy of both OH-CATH30 and its analog D-OH-CATH30 against clinical isolates comparing with routinely utilized antibiotics in vitro. In this study, 584 clinical isolates were tested (spanning 2013-2016) and the efficacy of the candidate peptides and antibiotics were determined by a broth microdilution method according to the CLSI guidelines. Among the 584 clinical isolates, 85% were susceptible to OH-CATH30 and its analogs. Both L- and D-OH-CATH30 showed higher efficacy against (toward) Gram-positive bacteria and stronger antibacterial activity against nearly all Gram-negative bacteria tested compare with antibiotics. The highest bactericidal activity was detected against Acinetobacter spp., including multi-drug-resistant Acinetobacter baumannfi (MRAB) and methicillin-resistant Staphylococcus aureus (MRSA). The overall efficacy of OH-CATH30 and its analogs was higher than that of the 9 routinely used antibiotics. OH-CATH30 is a promising candidate drug for the treatment of a wide variety of bacterial infections which are resistant to many routinely used antimicrobial agents.展开更多
Objective: To analyze clinical psychological nursing research hotspots in China and variation trends in order to provide reference points on the current state of development of clinical psychological nursing and futur...Objective: To analyze clinical psychological nursing research hotspots in China and variation trends in order to provide reference points on the current state of development of clinical psychological nursing and future research hotspots.Method: Clinical psychological nursing research literature sourced from Wanfang Data for the three periods of 2007-2009, 2010-2012, and 2013-2015 were selected as the research sample. A bibliographic co-occurrence analysis system(BICOMB software) was used to perform keyword word frequency analysis and generate a keyword co-occurrence matrix. In addition, Ucinet software's Netdraw tool was used to create visualized network diagrams.Results: A total of 27890 articles were retrieved, and word frequency analysis revealed that the highestfrequency keywords consisted of anxiety, depression, the elderly, expectant women, coronary heart disease, diabetes, breast cancer, perioperative period, quality of life, and psychological intervention.Research hotspot analysis revealed that consistent hotspots comprised anxiety, depression, health education, and perioperative period; expectant women became a hotspot during 2010-2012, and quality of life and efficacy became hotspots during 2013-2015.Conclusions: In addition to the care process, clinical psychological nursing research hotspots in China have increasingly included the effectiveness of psychological nursing and impact on patient quality of life. In addition, research hotspots have been influenced by the incidence of illnesses and people's health consciousness.展开更多
The pyrolysis under inert atmosphere has been widely used for the synthesis of metal containing heteroatoms doped carbon materials, versatile catalysts for various reactions. However, it is difficult to prevent metal ...The pyrolysis under inert atmosphere has been widely used for the synthesis of metal containing heteroatoms doped carbon materials, versatile catalysts for various reactions. However, it is difficult to prevent metal nanoparticles aggregation during pyrolysis process. Herein, we reported the efficient synthesis of nitrogen doped carbon hollow nanospheres with cobalt nanoparticles (Co NP, ca. 10nm in size) distributed uniformly in the shell via pyrolysis of yolk-shell structured Zn-Co-ZIFs@polydopamine (PDA). PDA acted as both protection layer and carbon source, which successfully prevented the aggregation of cobalt nanoparticles during high-temperature pyrolysis process. The Co NP and N containing carbon (Co NP/NC) hollow nanospheres were active for both oxygen evolution reaction (OER) and oxygen reduction reaction (ORR), affording overpotential of 430 mV at 10 mA/cm2 for OER in 1 M KOH and comparable half-wave potential to that of Pt/C (0.80V vs RHE) for ORR in 0.1 M KOH. The superior performance of carbon hollow nanospheres for both OER and ORR was mainly attributed to its small metal nanoparticles, N-doping and hollow nanostructure. The protection and confinement effect that originated from PDA coating strategy could be extended to the synthesis of other hollow structured carbon materials, especially the ones with small metal nanoparticles.展开更多
In this paper,an oil well production scheduling problem for the light load oil well during petroleum field exploitation was studied.The oil well production scheduling was to determine the turn on/off status and oil fl...In this paper,an oil well production scheduling problem for the light load oil well during petroleum field exploitation was studied.The oil well production scheduling was to determine the turn on/off status and oil flow rates of the wells in a given oil reservoir,subject to a number of constraints such as minimum up/down time limits and well grouping.The problem was formulated as a mixed integer nonlinear programming model that minimized the total production operating cost and start-up cost.Due to the NP-hardness of the problem,an improved particle swarm optimization(PSO) algorithm with a new velocity updating formula was developed to solve the problem approximately.Computational experiments on randomly generated instances were carried out to evaluate the performance of the model and the algorithm's effectiveness.Compared with the commercial solver CPLEX,the improved PSO can obtain high-quality schedules within a much shorter running time for all the instances.展开更多
Molybdenum sulfide(MoS_(2))with well-designed porous structure has the potential to be great electrode materials in sodium-ion batteries due to its high theoretical capacity and abundant resource,however,hindered by i...Molybdenum sulfide(MoS_(2))with well-designed porous structure has the potential to be great electrode materials in sodium-ion batteries due to its high theoretical capacity and abundant resource,however,hindered by its intrinsic low conductivity and stability.Herein,MoS_(2) with 3 D macroporous foam structure and high conductivity was obtained through SiO_(2) templates and integrated with carbon paper(3 D FMoS_(2)/CP).It has showed superior specific capacity(225 m A h g^(-1),0.4–3 V)and cycling stability(1000 cycles)at high rate(2000 m A g^(-1)),with a low decay rate(0.033%per cycle)in sodium-ion batteries.The excellent electrochemical performance may originate from its unique integrated structure:3 D MoS_(2) macropores providing high surface area and abundant transfer channels while carbon paper enhancing the conductivity of MoS_(2) and avoiding unnecessary side reactions brought by binder addition.展开更多
This paper proposes a simple constant-stress accel- erated life test (ALT) model from Burr type XII distribution when the data are Type-I progressively hybrid censored. The maximum likelihood estimation (MLE) of t...This paper proposes a simple constant-stress accel- erated life test (ALT) model from Burr type XII distribution when the data are Type-I progressively hybrid censored. The maximum likelihood estimation (MLE) of the parameters is obtained through the numerical method for solving the likelihood equations. Approxi- mate confidence interval (CI), based on normal approximation to the asymptotic distribution of MLE and percentile bootstrap Cl is derived. Finally, a numerical example is introduced and then a Monte Carlo simulation study is carried out to illustrate the pro- posed method.展开更多
Roles of Keap1-Nrf2 pathway in brain:Neuronal survival and neurogenesis are impaired in neurodegenerative diseases such as Parkinson's disease and Alzheimer's disease(Winner et al.,2011).Genetic up-regulation of ...Roles of Keap1-Nrf2 pathway in brain:Neuronal survival and neurogenesis are impaired in neurodegenerative diseases such as Parkinson's disease and Alzheimer's disease(Winner et al.,2011).Genetic up-regulation of growth factors enhanced neuronal survival and neurogenesis.展开更多
Machilus spp.are mostly valuable timber and economic tree species,widely used in many fields such as artificial afforestation,landscaping,furniture and building materials,chemicals and medicine.In this article,the dis...Machilus spp.are mostly valuable timber and economic tree species,widely used in many fields such as artificial afforestation,landscaping,furniture and building materials,chemicals and medicine.In this article,the distribution,uses and domestic resources of Machilus Nees are summarized.Focus is placed on the analysis of propagation methods,including seed propagation,cutting propagation and tissue culture propagation.The research status and existing problems are summarized,and the future research focus on the propagation technology of Machilus Nees is prospected,with a view to provide theoretical references for the efficient breeding of high-quality seedlings and comprehensive promotion and application of Machilus spp.and contribute to the conservation and sustainable use of wild resources.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
Malignant tumors,known as chronic wasting diseases,have a high risk of malnutrition.8%to 40%of cancer patients lose 10%or more of their weight.Malnutrition in digestive system cancer(28%−75%)is more common and more se...Malignant tumors,known as chronic wasting diseases,have a high risk of malnutrition.8%to 40%of cancer patients lose 10%or more of their weight.Malnutrition in digestive system cancer(28%−75%)is more common and more serious than in non-digestive system cancer(8%-46.9%)[1].The nutritional indexes such as BMI,Hb,ALB,PA,et al.of digestive system cancer patients are lower than those of non-digestive system cancer patients.Malnourished tumor patients have poor wound healing,prolonged hospital stay,increased cost,mortality and the incidence of complications[2].However,some studies have found that increased nutrition of tumor patients will promote the proliferation and spread of cancer cells and increase the chance of metastasis,which puts the nutritional treatment of tumors in a dilemma.Should cancer patients be treated with nutrition?展开更多
With the development of globalization and artificial intelligence,as well as the outbreak of COVID-19,unmanned vehicles have played an important role in cargo distribution.In order to better analyze the research direc...With the development of globalization and artificial intelligence,as well as the outbreak of COVID-19,unmanned vehicles have played an important role in cargo distribution.In order to better analyze the research directions of unmanned vehicle distribution,this paper summarizes the models and algorithms of unmanned vehicle distribution optimization.The research results show that most of the studies have established the goal of optimizing the total costs or travel time.Many researchers have begun to study multi-objective optimization problems,but there are certain limitations,so some studies convert these problems into single-objective optimization for solving,such as converting time and energy consumption into cost,waiting time into distance,and time delay into penalty cost.With the development of unmanned vehicle distribution technology,in future research,a multi-objective model with the lowest cost,the shortest distance and the best security should be established and solved.Most studies have proposed heuristic algorithms for solving the unmanned vehicle distribution problem,and improved optimization solutions have been obtained.In order to ensure the diversity of solution methods,and give consideration to solution time and solution quality,hybrid methods with other algorithms will be a future research direction,for example,the combination of heuristic algorithm and exact algorithm.With the gradual deepening of research,integrated distribution of multiple types of unmanned equipment will become the focus of future research.展开更多
Controlling the morphology of the MAPbI3-xClx active layer has remained a challenge towards advancing perovskite solar cells (PvSCs). Here, we demonstrate that a low temperature additive dripping (AD) treatment st...Controlling the morphology of the MAPbI3-xClx active layer has remained a challenge towards advancing perovskite solar cells (PvSCs). Here, we demonstrate that a low temperature additive dripping (AD) treatment step, using diphenyl ether (DPE), can significantly improve the power conversion efficiency (PCE), compared to the control device using chlorobenzene (CB), by 15% up to 16.64%, with a high current density (Jsc) of 22.67 mA/cm^2. We chose DPE for its small and appropriate dipole moment to adjust the solubility of the MAPbI3-xClx precursor during the formation of the intermediate phase and the MAPbI3-xClx phase. The low DPE vapor pressure provides a longer processing window for the removal of residual dimethylformamide (DMF), during the annealing process, for improved perovskite formation. Imaging and X-ray analysis both reveal that the MAPbI3-xClx film exhibits enlarged grains with increased crystallinity. Together, these improvements result in reduced carrier recombination and hole trap-state density in the MAPbI3-xClx film, while minimizing the hysteresis problem typical of PvSCs. These results show that the AD approach is a promising technique for improving PvSCs.展开更多
This study aimed to establish a rapid analytical method to determine antioxidants in essence. A simple,efficient and practical, vortex-assisted, cloud-point extraction(VACPE) procedure is proposed for extracting and...This study aimed to establish a rapid analytical method to determine antioxidants in essence. A simple,efficient and practical, vortex-assisted, cloud-point extraction(VACPE) procedure is proposed for extracting and pre-concentrating four different of synthetic phenolic antioxidants(SPAs), propyl gallate(PG), tert-butylhydroquinone(TBHQ), butylated hydroxyanisole(BHA), butylated hydroxytoluene(BHT) in essence prior to high performance liquid chromatography(HPLC) analysis. The non-ionic surfactant, fatty alcohol polyoxyethylene ether-9(AEO-9), was used as extractant and vortex-mixing was utilized to reduce extraction time and improve extraction efficiency. The effective parameters of the extraction process, such as volume of extraction solvent, pH, vortex-mixing time, equilibration temperature and time, were optimized. Under the optimum conditions, the linear range of PG, TBHQ,BHA and BHT was 8.0–800 ng/mL. All correlation coefficients of the calibration curves were higher than0.996 and relative standard deviations(RSD, n = 5) were 2.36%–5.46%. The proposed method was successfully applied to the extraction and determination of antioxidants in essence samples with satisfactory relative recoveries of 89.4%–103.5%. The results confirmed the SPAs of essence could be effectively monitored by this method and also established good reference criteria for essence.展开更多
The investment problem of oilfield development is to trade off the investment exploration investment and development investment.With low return on investment got by using the existing method to solve this problem,we c...The investment problem of oilfield development is to trade off the investment exploration investment and development investment.With low return on investment got by using the existing method to solve this problem,we construct an optimal model to improve it based on Data Envelopment Analysis(DEA)method and the relations about investment and proven reserves,investment and output as well as production cost.Data Envelopment Analysis(DEA)method is used to present a method to determine the optimal scale of productivity construction investment in unit production.The relation between total cumulated proven reserves and cumulative exploration investment is denoted as an exponential model.The relation among productions and remaining recoverable reserves as well as production cost may be described as an exponential operational cost function.Based on above two relation models and investment effectiveness coefficients of every block,we establish an optimal model whose objective function is net present value(NPV)profit maximum,whose constrain conditions include investment,reserve/production ratio,production and some equality constraints under the mode of sustainable development.It can be solved by genetic algorithms.The result of case study shows that this optimal investment of oilfield development has multi-stage investment structure under given conditions;the model can provide scientific basic theory for oil companies to make a long-term strategic program and investment plan in oil exploration and development,may decrease the subjective blindness in the investment and bring about a reasonable and orderly exploration and development of oil resources.展开更多
The morphology and structure of zinc oxide(ZnO), one of the important semiconductors, are relevant to its properties and applications. The preparation of ZnO with tunable morphology and desired structure is an attract...The morphology and structure of zinc oxide(ZnO), one of the important semiconductors, are relevant to its properties and applications. The preparation of ZnO with tunable morphology and desired structure is an attractive topic in the field of material synthesis. This work reports a facile method for the synthesis of Zn O with controllable morphology and crystal orientation using Zn-based coordination polymer particles(Zn-CPP) as precursors. Using hydrothermal method, Zn-CPP with morphologies of microrod, nanoplate, flower-like, arrow-tipped microsheet, and square cylinder were successfully synthesized via the coordination between metal ions Zn2+ and organic ligand 1,4,5,8-naphthalenetetracarboxylic dianhydride in aqueous solution. Subsequent thermal treatment of the Zn-CPP successfully resulted in the formation of porous Zn O with similar morphology to Zn-CPP. It is also found that the Zn O with enhanced(002) orientation could be obtained from Zn-CPP with preferred(002) orientation. This strategy could be extended for the preparation of other metal oxides with desired shape and structure.展开更多
Objective:To explore the mechanism underlying the effect of Panax notoginseng saponins(PNS)on the pharmacokinetics of nifedipine(NF)in rats.Materials and Methods:Twenty-four rats were randomly divided into blank(BL)gr...Objective:To explore the mechanism underlying the effect of Panax notoginseng saponins(PNS)on the pharmacokinetics of nifedipine(NF)in rats.Materials and Methods:Twenty-four rats were randomly divided into blank(BL)group,PNS group,NF group,and PNS+NF group,with six rats in each group.Noncompartmental analysis and t-test were carried out to determine the difference between the pharmacokinetic parameters of NF in different groups.CYP3 A4 enzyme activity was calculated using the probe drug method.The mRNA and protein contents of CYP3 A4,nuclear receptor CAR,and PXR in rat liver were quantitatively analyzed by qRT-PCR and Western blot.Results:After the rats were treated with the combination of PNS and NF,the plasma concentration,half-life,peak time,and area under the concentration-time curve of NF increased,whereas the clearance rate decreased.The inhibitory effect on CYP3 A4 enzyme activity was in the following order:PNS+NF group(strongest)>PNS group>NF group,and BL group(weakest).Similar changes were observed for the inhibitory effect on CYP3 A4,CAR,and PXR mRNA and protein content,and the order was as follows:PNS+NF group(weakest)<PNS group<NF group,and BL group(strongest).Conclusion:In combination with NF,PNS may inhibit the mRNA and protein expression of nuclear receptor CAR and PXR and the activity of CYP3 A4 enzyme,slowing down the pharmacokinetics of NF in rats,increasing its blood concentration,and enhancing the therapeutic effect of NF.展开更多
文摘目的:探讨Pentacam眼前节分析仪和Keratron Scout角膜地形图仪测量Kappa角的一致性,评价两种仪器测量结果的重复性。方法:前瞻性随机对照研究。选取2018-01-01/30在我院眼视光中心行近视术前检查的患者69例,所有受试者由同一检查者分别采用Pentacam和Keratron Scout重复测量3次,以(X ,Y)坐标形式记录Kappa角的大小,采用组内相关系数(ICC)、Cronbach s Alpha系数评价两种仪器测量Kappa角的重复性;t 检验比较两种仪器测量结果的差异,Pearson相关分析其相关性;Bland-Altman图评估两种仪器测量结果的一致性。结果:3次重复测量时,两种仪器均表现出很好的重复性,两种仪器测得Kappa角差异无统计学意义( X 值: P =0.17;Y 值: P =0.61),Pearson相关分析表明Kappa角大小具有相关性(X 值: r =0.90, P <0.01;Y 值: r =0.91, P <0.01)。Bland-Altman图显示 X 值和 Y 值95%一致性区间分别为-0.11~0.14mm和-0.10~0.11mm。结论:Pentacam眼前节分析仪和Keratron Scout角膜地形图仪测量角膜屈光手术患者Kappa角重复性好,两种仪器测量的Kappa角结果一致性好,可以相互验证。
基金supported by the Fundamental Research Funds for the Central Universities(No.2019B00414)Open Fund of the Key Laboratory of Marine Geology and Environment Chinese Academy of Sciences(No.MGE2020KG03)the PHD early development program of East China University of Technology(No.DHBK2018035)。
文摘Lithosphere extension and upwelling of asthenosphere at post-collisional stage of an orogenic cycle generally induce diverse magmatism and/or associated high-temperature metamorphism. Nevertheless, the intimate coexistence of post-collisional magmatic activity and high-temperature metamorphism is rare.In this contribution, a lithological assemblage composing of diverse magmatic rocks deriving from distinct magma sources and coeval high-temperature metamorphism was identified in eastern Kunlun.Petrography, ages, mineral chemistry and whole-rock geochemistry demonstrated that those intimately coexistent diverse rocks were genetically related to post-collisional extension. The garnet-bearing mafic granulites in Jinshuikou area interior of the East Kunlun Orogenic Belt are mainly composed of garnet,orthopyroxene, and plagioclase, with peak metamorphic P–T conditions of ~ 701–756 ℃and 5.6–7.0 kbar,representing a granulite-facies metamorphism at 409.7 ± 1.7 Ma. The diverse contemporaneous magmatic rocks including hornblendites, gabbros and granites yield zircon U–Pb ages of 408.6 ± 2.5 Ma,413.4 ± 4.6 Ma, and 387–407 Ma, respectively. The hornblendites show N-MORB-like REE patterns with(La/Sm)Nvalues of 0.85–0.94. They have positive zircon εHf(t) values of 0.1–4.9 and whole-rock εNd(t) values of 3.9–4.7 but relatively high(^(87)Sr/^(86)Sr)_(i)values of 0.7081 to 0.7088. These features demonstrate that the hornblendites derived from a depleted asthenospheric mantle source with minor continental crustal materials in source. As for the gabbros, they exhibit arc-like elemental signatures, low zircon εHf(t) values(-4.3 to 2.5) and variable whole-rock εNd(t) values(-4.9 to 1.2) as well as high(^(87)Sr/86 Sr)ivalues(0.7068 to 0.7126), arguing for that they were originated from partial melting of heterogeneous lithospheric mantle anteriorly metasomatized by subducted-sediment released melts. Geochemistry of the granites defines their strongly peraluminous S-type signatures. Zircons from the granites yield a large range of εHf(t) values ranging from -30.8 to -5.1, while the whole-rock samples yield consistent(^(87)Sr/86 Sr)ivalues(0.7301 to 0.7342) and negative εNd(t) values(-10.1 to -12.4). These features indicate that the S-type granites could be generated by reworking of an ancient crust. Taken together, the penecontemporaneous magmatism and metamorphic event, demonstrated the early-middle Devonian transition from crustal thickening to extensional collapse. The post-collisional mantle-derived magmas serve as an essential driving force for the high-temperature granulite-facies metamorphism and anataxis of the crust associated with formation of S-type granite. This study not only constructs a more detail Proto-Tethys evolution process of the eastern Kunlun, but also sheds new light on better understanding the intimate relationship between magmatism and metamorphism during post-collisional extensional collapse.
基金supported by grants from the National Natural Sciences Foundation of China(31572268,31560596)the Key Research Program of the Chinese Academy of Sciences(KJZD-EW-L03)+3 种基金"Yunnan Scholar"Programthe Yunnan Applied Basic Research Projects(2016FD076)the National Training Program of Innovation and Entrepreneurship for Undergraduates(201510685001201610685001)Puer University(RCXM003&CXTD011)
文摘Cationic antimicrobial peptides (AMPs) are considered as important candidate therapeutic agents, which exert potent microbicidal properties against bacteria, fungi and some viruses. Based on our previous findings king cobra cathelicidin (OH-CATH) is a 34-amino acid peptide that exerts strong antibacterial and weak hemolytic activity. The aim of this research is to evaluate the efficacy of both OH-CATH30 and its analog D-OH-CATH30 against clinical isolates comparing with routinely utilized antibiotics in vitro. In this study, 584 clinical isolates were tested (spanning 2013-2016) and the efficacy of the candidate peptides and antibiotics were determined by a broth microdilution method according to the CLSI guidelines. Among the 584 clinical isolates, 85% were susceptible to OH-CATH30 and its analogs. Both L- and D-OH-CATH30 showed higher efficacy against (toward) Gram-positive bacteria and stronger antibacterial activity against nearly all Gram-negative bacteria tested compare with antibiotics. The highest bactericidal activity was detected against Acinetobacter spp., including multi-drug-resistant Acinetobacter baumannfi (MRAB) and methicillin-resistant Staphylococcus aureus (MRSA). The overall efficacy of OH-CATH30 and its analogs was higher than that of the 9 routinely used antibiotics. OH-CATH30 is a promising candidate drug for the treatment of a wide variety of bacterial infections which are resistant to many routinely used antimicrobial agents.
基金supported by a scientific research project of Shanxi Provincial Health Department,China(No.201201031)
文摘Objective: To analyze clinical psychological nursing research hotspots in China and variation trends in order to provide reference points on the current state of development of clinical psychological nursing and future research hotspots.Method: Clinical psychological nursing research literature sourced from Wanfang Data for the three periods of 2007-2009, 2010-2012, and 2013-2015 were selected as the research sample. A bibliographic co-occurrence analysis system(BICOMB software) was used to perform keyword word frequency analysis and generate a keyword co-occurrence matrix. In addition, Ucinet software's Netdraw tool was used to create visualized network diagrams.Results: A total of 27890 articles were retrieved, and word frequency analysis revealed that the highestfrequency keywords consisted of anxiety, depression, the elderly, expectant women, coronary heart disease, diabetes, breast cancer, perioperative period, quality of life, and psychological intervention.Research hotspot analysis revealed that consistent hotspots comprised anxiety, depression, health education, and perioperative period; expectant women became a hotspot during 2010-2012, and quality of life and efficacy became hotspots during 2013-2015.Conclusions: In addition to the care process, clinical psychological nursing research hotspots in China have increasingly included the effectiveness of psychological nursing and impact on patient quality of life. In addition, research hotspots have been influenced by the incidence of illnesses and people's health consciousness.
文摘The pyrolysis under inert atmosphere has been widely used for the synthesis of metal containing heteroatoms doped carbon materials, versatile catalysts for various reactions. However, it is difficult to prevent metal nanoparticles aggregation during pyrolysis process. Herein, we reported the efficient synthesis of nitrogen doped carbon hollow nanospheres with cobalt nanoparticles (Co NP, ca. 10nm in size) distributed uniformly in the shell via pyrolysis of yolk-shell structured Zn-Co-ZIFs@polydopamine (PDA). PDA acted as both protection layer and carbon source, which successfully prevented the aggregation of cobalt nanoparticles during high-temperature pyrolysis process. The Co NP and N containing carbon (Co NP/NC) hollow nanospheres were active for both oxygen evolution reaction (OER) and oxygen reduction reaction (ORR), affording overpotential of 430 mV at 10 mA/cm2 for OER in 1 M KOH and comparable half-wave potential to that of Pt/C (0.80V vs RHE) for ORR in 0.1 M KOH. The superior performance of carbon hollow nanospheres for both OER and ORR was mainly attributed to its small metal nanoparticles, N-doping and hollow nanostructure. The protection and confinement effect that originated from PDA coating strategy could be extended to the synthesis of other hollow structured carbon materials, especially the ones with small metal nanoparticles.
基金Supported by National High Technology Research and Development Program of China(2013AA040704)the Fund for the National Natural Science Foundation of China(61374203)
文摘In this paper,an oil well production scheduling problem for the light load oil well during petroleum field exploitation was studied.The oil well production scheduling was to determine the turn on/off status and oil flow rates of the wells in a given oil reservoir,subject to a number of constraints such as minimum up/down time limits and well grouping.The problem was formulated as a mixed integer nonlinear programming model that minimized the total production operating cost and start-up cost.Due to the NP-hardness of the problem,an improved particle swarm optimization(PSO) algorithm with a new velocity updating formula was developed to solve the problem approximately.Computational experiments on randomly generated instances were carried out to evaluate the performance of the model and the algorithm's effectiveness.Compared with the commercial solver CPLEX,the improved PSO can obtain high-quality schedules within a much shorter running time for all the instances.
基金supported financially by the National Key R&D Program of China(No.2016YFA0204100,2016YFA0200200)the National Natural Science Foundation of China(No.21890753,21988101,21905035)+1 种基金the Danish company Haldor Tops?e A/S,Liaoning Revitalization Talents Program(XLYC1907093)the Liaoning Natural Science Foundation(20180510043)。
文摘Molybdenum sulfide(MoS_(2))with well-designed porous structure has the potential to be great electrode materials in sodium-ion batteries due to its high theoretical capacity and abundant resource,however,hindered by its intrinsic low conductivity and stability.Herein,MoS_(2) with 3 D macroporous foam structure and high conductivity was obtained through SiO_(2) templates and integrated with carbon paper(3 D FMoS_(2)/CP).It has showed superior specific capacity(225 m A h g^(-1),0.4–3 V)and cycling stability(1000 cycles)at high rate(2000 m A g^(-1)),with a low decay rate(0.033%per cycle)in sodium-ion batteries.The excellent electrochemical performance may originate from its unique integrated structure:3 D MoS_(2) macropores providing high surface area and abundant transfer channels while carbon paper enhancing the conductivity of MoS_(2) and avoiding unnecessary side reactions brought by binder addition.
基金supported by the National Natural Science Foundation of China(7117116470471057)
文摘This paper proposes a simple constant-stress accel- erated life test (ALT) model from Burr type XII distribution when the data are Type-I progressively hybrid censored. The maximum likelihood estimation (MLE) of the parameters is obtained through the numerical method for solving the likelihood equations. Approxi- mate confidence interval (CI), based on normal approximation to the asymptotic distribution of MLE and percentile bootstrap Cl is derived. Finally, a numerical example is introduced and then a Monte Carlo simulation study is carried out to illustrate the pro- posed method.
基金supported by the following grants to JHR:General Research Fund(GRF)(HKU 775812M)from the Research Grants Council of Hong Kongthe Seed Fund for Basic Research ProgramThe University of Hong Kong
文摘Roles of Keap1-Nrf2 pathway in brain:Neuronal survival and neurogenesis are impaired in neurodegenerative diseases such as Parkinson's disease and Alzheimer's disease(Winner et al.,2011).Genetic up-regulation of growth factors enhanced neuronal survival and neurogenesis.
基金Forestry Science and Technology Innovation Project of Guangdong Province(14KJCX005-02).
文摘Machilus spp.are mostly valuable timber and economic tree species,widely used in many fields such as artificial afforestation,landscaping,furniture and building materials,chemicals and medicine.In this article,the distribution,uses and domestic resources of Machilus Nees are summarized.Focus is placed on the analysis of propagation methods,including seed propagation,cutting propagation and tissue culture propagation.The research status and existing problems are summarized,and the future research focus on the propagation technology of Machilus Nees is prospected,with a view to provide theoretical references for the efficient breeding of high-quality seedlings and comprehensive promotion and application of Machilus spp.and contribute to the conservation and sustainable use of wild resources.
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Malignant tumors,known as chronic wasting diseases,have a high risk of malnutrition.8%to 40%of cancer patients lose 10%or more of their weight.Malnutrition in digestive system cancer(28%−75%)is more common and more serious than in non-digestive system cancer(8%-46.9%)[1].The nutritional indexes such as BMI,Hb,ALB,PA,et al.of digestive system cancer patients are lower than those of non-digestive system cancer patients.Malnourished tumor patients have poor wound healing,prolonged hospital stay,increased cost,mortality and the incidence of complications[2].However,some studies have found that increased nutrition of tumor patients will promote the proliferation and spread of cancer cells and increase the chance of metastasis,which puts the nutritional treatment of tumors in a dilemma.Should cancer patients be treated with nutrition?
基金supported by the National Key Research and Development Program of China under Grant 2021YFE0203600the National Natural Science Foundation of China(72274024)。
文摘With the development of globalization and artificial intelligence,as well as the outbreak of COVID-19,unmanned vehicles have played an important role in cargo distribution.In order to better analyze the research directions of unmanned vehicle distribution,this paper summarizes the models and algorithms of unmanned vehicle distribution optimization.The research results show that most of the studies have established the goal of optimizing the total costs or travel time.Many researchers have begun to study multi-objective optimization problems,but there are certain limitations,so some studies convert these problems into single-objective optimization for solving,such as converting time and energy consumption into cost,waiting time into distance,and time delay into penalty cost.With the development of unmanned vehicle distribution technology,in future research,a multi-objective model with the lowest cost,the shortest distance and the best security should be established and solved.Most studies have proposed heuristic algorithms for solving the unmanned vehicle distribution problem,and improved optimization solutions have been obtained.In order to ensure the diversity of solution methods,and give consideration to solution time and solution quality,hybrid methods with other algorithms will be a future research direction,for example,the combination of heuristic algorithm and exact algorithm.With the gradual deepening of research,integrated distribution of multiple types of unmanned equipment will become the focus of future research.
基金The authors gratefully acknowledge the Fundamental Research Funds for the Central Universities (No. S16JB00060), the National Science Foundation, NSF- PECASE award (No. CBET-0954985) and the National Natural Science Foundation of China (No. 61575019) for partial support of this work. D. H. also thanks the support from the China Scholarship Council. The AFM SEM used were supported by the Yale Institute for Nanoscience and Quantum Engineering (YINQE) and NSF MRSEC DMR 1119826 for Center for Research on Interface Structures and Phenomena (CRISP). The GIWAXS obtained at 1W1A, BSRF. The authors further thank scientists of Diffuse X-ray Scattering Station in the experiments for the assistance with GIWAXS measurements, as well as Dr. Yuchuan Shao from the Depai-anent of Electrical Engineering, Yale University for the useful discussion.
文摘Controlling the morphology of the MAPbI3-xClx active layer has remained a challenge towards advancing perovskite solar cells (PvSCs). Here, we demonstrate that a low temperature additive dripping (AD) treatment step, using diphenyl ether (DPE), can significantly improve the power conversion efficiency (PCE), compared to the control device using chlorobenzene (CB), by 15% up to 16.64%, with a high current density (Jsc) of 22.67 mA/cm^2. We chose DPE for its small and appropriate dipole moment to adjust the solubility of the MAPbI3-xClx precursor during the formation of the intermediate phase and the MAPbI3-xClx phase. The low DPE vapor pressure provides a longer processing window for the removal of residual dimethylformamide (DMF), during the annealing process, for improved perovskite formation. Imaging and X-ray analysis both reveal that the MAPbI3-xClx film exhibits enlarged grains with increased crystallinity. Together, these improvements result in reduced carrier recombination and hole trap-state density in the MAPbI3-xClx film, while minimizing the hysteresis problem typical of PvSCs. These results show that the AD approach is a promising technique for improving PvSCs.
基金supported by College of Life Science and Technology, Kunming University of Science and Technology
文摘This study aimed to establish a rapid analytical method to determine antioxidants in essence. A simple,efficient and practical, vortex-assisted, cloud-point extraction(VACPE) procedure is proposed for extracting and pre-concentrating four different of synthetic phenolic antioxidants(SPAs), propyl gallate(PG), tert-butylhydroquinone(TBHQ), butylated hydroxyanisole(BHA), butylated hydroxytoluene(BHT) in essence prior to high performance liquid chromatography(HPLC) analysis. The non-ionic surfactant, fatty alcohol polyoxyethylene ether-9(AEO-9), was used as extractant and vortex-mixing was utilized to reduce extraction time and improve extraction efficiency. The effective parameters of the extraction process, such as volume of extraction solvent, pH, vortex-mixing time, equilibration temperature and time, were optimized. Under the optimum conditions, the linear range of PG, TBHQ,BHA and BHT was 8.0–800 ng/mL. All correlation coefficients of the calibration curves were higher than0.996 and relative standard deviations(RSD, n = 5) were 2.36%–5.46%. The proposed method was successfully applied to the extraction and determination of antioxidants in essence samples with satisfactory relative recoveries of 89.4%–103.5%. The results confirmed the SPAs of essence could be effectively monitored by this method and also established good reference criteria for essence.
文摘The investment problem of oilfield development is to trade off the investment exploration investment and development investment.With low return on investment got by using the existing method to solve this problem,we construct an optimal model to improve it based on Data Envelopment Analysis(DEA)method and the relations about investment and proven reserves,investment and output as well as production cost.Data Envelopment Analysis(DEA)method is used to present a method to determine the optimal scale of productivity construction investment in unit production.The relation between total cumulated proven reserves and cumulative exploration investment is denoted as an exponential model.The relation among productions and remaining recoverable reserves as well as production cost may be described as an exponential operational cost function.Based on above two relation models and investment effectiveness coefficients of every block,we establish an optimal model whose objective function is net present value(NPV)profit maximum,whose constrain conditions include investment,reserve/production ratio,production and some equality constraints under the mode of sustainable development.It can be solved by genetic algorithms.The result of case study shows that this optimal investment of oilfield development has multi-stage investment structure under given conditions;the model can provide scientific basic theory for oil companies to make a long-term strategic program and investment plan in oil exploration and development,may decrease the subjective blindness in the investment and bring about a reasonable and orderly exploration and development of oil resources.
基金supported by the National Natural Science Foundation of China(21325313)
文摘The morphology and structure of zinc oxide(ZnO), one of the important semiconductors, are relevant to its properties and applications. The preparation of ZnO with tunable morphology and desired structure is an attractive topic in the field of material synthesis. This work reports a facile method for the synthesis of Zn O with controllable morphology and crystal orientation using Zn-based coordination polymer particles(Zn-CPP) as precursors. Using hydrothermal method, Zn-CPP with morphologies of microrod, nanoplate, flower-like, arrow-tipped microsheet, and square cylinder were successfully synthesized via the coordination between metal ions Zn2+ and organic ligand 1,4,5,8-naphthalenetetracarboxylic dianhydride in aqueous solution. Subsequent thermal treatment of the Zn-CPP successfully resulted in the formation of porous Zn O with similar morphology to Zn-CPP. It is also found that the Zn O with enhanced(002) orientation could be obtained from Zn-CPP with preferred(002) orientation. This strategy could be extended for the preparation of other metal oxides with desired shape and structure.
基金supported by Heilongjiang Natural Science Foundation(No.LH2019H107)Innovation Fund for postgraduates of Heilongjiang University of Chinese Medicine(No.2020yjscx058)。
文摘Objective:To explore the mechanism underlying the effect of Panax notoginseng saponins(PNS)on the pharmacokinetics of nifedipine(NF)in rats.Materials and Methods:Twenty-four rats were randomly divided into blank(BL)group,PNS group,NF group,and PNS+NF group,with six rats in each group.Noncompartmental analysis and t-test were carried out to determine the difference between the pharmacokinetic parameters of NF in different groups.CYP3 A4 enzyme activity was calculated using the probe drug method.The mRNA and protein contents of CYP3 A4,nuclear receptor CAR,and PXR in rat liver were quantitatively analyzed by qRT-PCR and Western blot.Results:After the rats were treated with the combination of PNS and NF,the plasma concentration,half-life,peak time,and area under the concentration-time curve of NF increased,whereas the clearance rate decreased.The inhibitory effect on CYP3 A4 enzyme activity was in the following order:PNS+NF group(strongest)>PNS group>NF group,and BL group(weakest).Similar changes were observed for the inhibitory effect on CYP3 A4,CAR,and PXR mRNA and protein content,and the order was as follows:PNS+NF group(weakest)<PNS group<NF group,and BL group(strongest).Conclusion:In combination with NF,PNS may inhibit the mRNA and protein expression of nuclear receptor CAR and PXR and the activity of CYP3 A4 enzyme,slowing down the pharmacokinetics of NF in rats,increasing its blood concentration,and enhancing the therapeutic effect of NF.