期刊文献+
共找到227,479篇文章
< 1 2 250 >
每页显示 20 50 100
Hemorrhagic transformation in patients with large-artery atherosclerotic stroke is associated with the gut microbiota and lipopolysaccharide
1
作者 Qin Huang Minping Wei +3 位作者 Xianjing Feng Yunfang Luo Yunhai Liu Jian Xia 《Neural Regeneration Research》 SCIE CAS CSCD 2024年第7期1532-1540,共9页
Hemorrhagic transformation is a major complication of large-artery atheroscle rotic stroke(a major ischemic stro ke subtype)that wo rsens outcomes and increases mortality.Disruption of the gut microbiota is an importa... Hemorrhagic transformation is a major complication of large-artery atheroscle rotic stroke(a major ischemic stro ke subtype)that wo rsens outcomes and increases mortality.Disruption of the gut microbiota is an important feature of stroke,and some specific bacteria and bacterial metabolites may contribute to hemorrhagic transformation pathogenesis.We aimed to investigate the relationship between the gut microbiota and hemorrhagic transformation in largearte ry atheroscle rotic stro ke.An observational retrospective study was conducted.From May 2020 to September 2021,blood and fecal samples were obtained upon admission from 32 patients with first-ever acute ischemic stroke and not undergoing intravenous thrombolysis or endovascular thrombectomy,as well as 16 healthy controls.Patients with stro ke who developed hemorrhagic transfo rmation(n=15)were compared to those who did not develop hemorrhagic transformation(n=17)and with healthy controls.The gut microbiota was assessed through 16S ribosomal ribonucleic acid sequencing.We also examined key components of the lipopolysaccharide pathway:lipopolysaccharide,lipopolysaccharide-binding protein,and soluble CD14.We observed that bacterial diversity was decreased in both the hemorrhagic transformation and non-hemorrhagic transfo rmation group compared with the healthy controls.The patients with ischemic stro ke who developed hemorrhagic transfo rmation exhibited altered gut micro biota composition,in particular an increase in the relative abundance and dive rsity of members belonging to the Enterobacteriaceae family.Plasma lipopolysaccharide and lipopolysaccharide-binding protein levels were higher in the hemorrhagic transformation group compared with the non-hemorrhagic transfo rmation group.lipopolysaccharide,lipopolysaccharide-binding protein,and soluble CD14 concentrations were associated with increased abundance of Enterobacte riaceae.Next,the role of the gut microbiota in hemorrhagic transformation was evaluated using an experimental stroke rat model.In this model,transplantation of the gut microbiota from hemorrhagic transformation rats into the recipient rats triggered higher plasma levels of lipopolysaccharide,lipopolysaccharide-binding protein,and soluble CD14.Ta ken togethe r,our findings demonstrate a noticeable change in the gut microbiota and lipopolysaccharide-related inflammatory response in stroke patients with hemorrhagic transformation.This suggests that maintaining a balanced gut microbiota may be an important factor in preventing hemorrhagic transfo rmation after stro ke. 展开更多
关键词 gut microbiota hemorrhagic transformation INFLAMMATION LIPOPOLYSACCHARIDE STROKE
下载PDF
Critical approaches in the catalytic transformation of sugar isomerization and epimerization after Fischer-History,challenges,and prospects
2
作者 Da-Ming Gao Xun Zhang +5 位作者 Haichao Liu Hidemi Fujino Tingzhou Lei Fuan Sun Jie Zhu Taoli Huhe 《Green Energy & Environment》 SCIE EI CAS CSCD 2024年第3期435-453,共19页
The transformation of aldose to ketose or common sugars into rare saccharides,including rare ketoses and aldoses,is of great value and interest to the food industry and for saccharidic biomass utilization,medicine,and... The transformation of aldose to ketose or common sugars into rare saccharides,including rare ketoses and aldoses,is of great value and interest to the food industry and for saccharidic biomass utilization,medicine,and the synthesis of drugs.Nowadays,high-fructose corn syrup(HFCS)is industrially produced in more than 10 million tons annually using immobilized glucose isomerase.Some low-calorie saccharides such as tagatose and psicose,which are becoming popular sweeteners,have also been produced on a pilot scale in order to replace sucrose and HFCS.However,current catalysts and catalytic processes are still difficult to utilize in biomass conversion and also have strong substrate dependence in producing high-value,rare sugars.Considering the specific reaction properties of saccharides and catalysts,since the pioneering discovery by Fischer,various catalysts and catalytic systems have been discovered or developed in attempts to extend the reaction pathways,improve the reaction efficiency,and to potentially produce commercial products.In this review,we trace the history of sugar isomerization/epimerization reactions and summarize the important breakthroughs for each reaction as well as the difficulties that remain unresolved to date. 展开更多
关键词 Rare sugars ISOMERIZATION Ketonization EPIMERIZATION Catalytic transformation
下载PDF
Formation and transformation of metastable LPSO building blocks clusters in Mg-Gd-Y-Zn-Zr alloys by spinodal decomposition and heterogeneous nucleation
3
作者 Xin Zhao Zhong Yang +2 位作者 Jiachen Zhang Minxian Liang Liying Wang 《Journal of Magnesium and Alloys》 SCIE EI CAS CSCD 2024年第2期673-686,共14页
To study the formation and transformation mechanism of long-period stacked ordered(LPSO)structures,a systematic atomic scale analysis was conducted for the structural evolution of long-period stacked ordered(LPSO)stru... To study the formation and transformation mechanism of long-period stacked ordered(LPSO)structures,a systematic atomic scale analysis was conducted for the structural evolution of long-period stacked ordered(LPSO)structures in the Mg-Gd-Y-Zn-Zr alloy annealed at 300℃~500℃.Various types of metastable LPSO building block clusters were found to exist in alloy structures at different temperatures,which precipitate during the solidification and homogenization process.The stability of Zn/Y clusters is explained by the first principles of density functional theory.The LPSO structure is distinguished by the arrangement of its different Zn/Y enriched LPSO structural units,which comprises local fcc stacking sequences upon a tightly packed plane.The presence of solute atoms causes local lattice distortion,thereby enabling the rearrangement of Mg atoms in the different configurations in the local lattice,and local HCP-FCC transitions occur between Mg and Zn atoms occupying the nearest neighbor positions.This finding indicates that LPSO structures can generate necessary Schockley partial dislocations on specific slip surfaces,providing direct evidence of the transition from 18R to 14H.Growth of the LPSO,devoid of any defects and non-coherent interfaces,was observed separately from other precipitated phases.As a result,the precipitation sequence of LPSO in the solidification stage was as follows:Zn/Ycluster+Mg layers→various metastable LPSO building block clusters→18R/24R LPSO;whereas the precipitation sequence of LPSO during homogenization treatment was observed to be as follows:18R LPSO→various metastable LPSO building block clusters→14H LPSO.Of these,14H LPSO was found to be the most thermodynamically stable structure. 展开更多
关键词 LPSO Spinodal decomposition Homogenization treatment CLUSTERS Phase transformation
下载PDF
Precise regulation of the phase transformation for pyrolusite during the reduction roasting process
4
作者 Ruofeng Wang Peng Gao +3 位作者 Shuai Yuan Yanjun Li Yingzhi Liu Cheng Huang 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CSCD 2024年第1期81-90,共10页
The mechanism involved in the phase transformation process of pyrolusite (MnO_(2)) during roasting in a reducing atmosphere was systematically elucidated in this study,with the aim of effectively using low-grade compl... The mechanism involved in the phase transformation process of pyrolusite (MnO_(2)) during roasting in a reducing atmosphere was systematically elucidated in this study,with the aim of effectively using low-grade complex manganese ore resources.According to single-factor experiment results,the roasted product with a divalent manganese (Mn^(2+)) distribution rate of 95.30% was obtained at a roasting time of 25 min,a roasting temperature of 700℃,a CO concentration of 20at%,and a total gas volume of 500 mL·min^(-1),in which the manganese was mainly in the form of manganosite (MnO).Scanning electron microscopy and Brunauer–Emmett–Teller theory demonstrated the microstructural evolution of the roasted product and the gradual reduction in the pyrolusite ore from the surface to the core Thermodynamic calculations,X-ray photoelectron spectroscopy,and X-ray diffractometry analyses determined that the phase transformation of pyrolusite followed the order of MnO_(2)→Mn_(2)O_(3)→Mn_(3)O_(4)→MnO phase by phase,and the reduction of manganese oxides in each valence state proceeded simultaneously. 展开更多
关键词 PYROLUSITE phase transformation reduction roasting microstructural evolution reaction mechanism
下载PDF
In situ observation of the phase transformation kinetics of bismuth during shock release
5
作者 李江涛 王倩男 +7 位作者 徐亮 柳雷 张航 Sota Takagi Kouhei Ichiyanagi Ryo Fukaya Shunsuke Nozawa 胡建波 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第4期586-592,共7页
A time-resolved x-ray diffraction technique is employed to monitor the structural transformation of laser-shocked bismuth.Results reveal a retarded transformation from the shock-induced Bi-Ⅴphase to a metastable Bi-... A time-resolved x-ray diffraction technique is employed to monitor the structural transformation of laser-shocked bismuth.Results reveal a retarded transformation from the shock-induced Bi-Ⅴphase to a metastable Bi-Ⅳphase during the shock release,instead of the thermodynamically stable Bi-Ⅲphase.The emergence of the metastable Bi-Ⅳphase is understood by the competitive interplay between two transformation pathways towards the Bi-Ⅳand Bi-Ⅲ,respectively.The former is more rapid than the latter because the Bi-Ⅴto B-Ⅳtransformation is driven by interaction between the closest atoms while the Bi-Ⅴto B-Ⅲtransformation requires interaction between the second-closest atoms.The nucleation time for the Bi-Ⅴto Bi-Ⅳtransformation is determined to be 5.1±0.9 ns according to a classical nucleation model.This observation demonstrates the importance of the formation of the transient metastable phases,which can change the phase transformation pathway in a dynamic process. 展开更多
关键词 phase transformation time-resolved x-ray diffraction(XRD) BISMUTH metastable phase nonequilibrium phase diagram
原文传递
Pre-existing orthorhombic embryos-induced hexagonal-orthorhombic martensitic transformation in MnNiSi_(1-x)(CoNiGe)_x alloy
6
作者 张婷婷 龚元元 +1 位作者 鲁子骞 徐锋 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第4期691-699,共9页
The thermal-elastic martensitic transformation from high-temperature Ni_(2)In-type hexagonal structure to low-temperature TiNiSi-type orthorhombic structure has been widely studied in MnMX(M=Ni or Co,and X=Ge or Si)al... The thermal-elastic martensitic transformation from high-temperature Ni_(2)In-type hexagonal structure to low-temperature TiNiSi-type orthorhombic structure has been widely studied in MnMX(M=Ni or Co,and X=Ge or Si)alloys.However,the answer to how the orthorhombic martensite nucleates and grows within the hexagonal parent is still unclear.In this work,the hexagonal-orthorhombic martensitic transformation in a Co and Ge co-substituted MnNiSi is investigated.One can find some orthorhombic laths embedded in the hexagonal parent at a temperature above the martensitic transformation start temperature(M_(s)).With the the sample cooing to M_(s),the laths turn broader,indicating that the martensitic transformation starts from these pre-existing orthorhombic laths.Microstructure observation suggests that these pre-existing orthorhombic laths do not originate from the hexagonal-orthorhombic martensitic transformation because of the difference between atomic occupations of doping elements in the hexagonal parent and those in the preexisting orthorhombic laths.The phenomenological crystallographic theory and experimental investigations prove that the pre-existing orthorhombic lath and generated orthorhombic martensite have the same crystallography relationship to the hexagonal parent.Therefore,the orthorhombic martensite can take these pre-existing laths as embryos and grow up.This work implies that the martensitic transformation in MnNiSi_(1-x)(CoNiGe)_(x) alloy is initiated by orthorhombic embryos. 展开更多
关键词 martensitic transformation MnMX alloy orthorhombic embryo crystallography relationship
原文传递
Efficient single-pixel imaging encrypted transmission based on 3D Arnold transformation
7
作者 梁振宇 王朝瑾 +4 位作者 王阳阳 高皓琪 朱东涛 许颢砾 杨星 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第3期378-386,共9页
Single-pixel imaging(SPI)can transform 2D or 3D image data into 1D light signals,which offers promising prospects for image compression and transmission.However,during data communication these light signals in public ... Single-pixel imaging(SPI)can transform 2D or 3D image data into 1D light signals,which offers promising prospects for image compression and transmission.However,during data communication these light signals in public channels will easily draw the attention of eavesdroppers.Here,we introduce an efficient encryption method for SPI data transmission that uses the 3D Arnold transformation to directly disrupt 1D single-pixel light signals and utilizes the elliptic curve encryption algorithm for key transmission.This encryption scheme immediately employs Hadamard patterns to illuminate the scene and then utilizes the 3D Arnold transformation to permutate the 1D light signal of single-pixel detection.Then the transformation parameters serve as the secret key,while the security of key exchange is guaranteed by an elliptic curve-based key exchange mechanism.Compared with existing encryption schemes,both computer simulations and optical experiments have been conducted to demonstrate that the proposed technique not only enhances the security of encryption but also eliminates the need for complicated pattern scrambling rules.Additionally,this approach solves the problem of secure key transmission,thus ensuring the security of information and the quality of the decrypted images. 展开更多
关键词 single-pixel imaging 3D Arnold transformation elliptic curve encryption image encryption
原文传递
Fast,simple,efficient Agrobacterium rhizogenes-mediated transformation system to non-heading Chinese cabbage with transgenic roots
8
作者 Huiyu Wang Yushan Zheng +3 位作者 Qian Zhou Ying Li Tongkun Liu Xilin Hou 《Horticultural Plant Journal》 SCIE CAS CSCD 2024年第2期450-460,共11页
Non-heading Chinese cabbage, a variety of Brassica campestris, is an important vegetable crop in the Yangtze River Basin of China. However,the immaturity of its stable transformation system and its low transformation ... Non-heading Chinese cabbage, a variety of Brassica campestris, is an important vegetable crop in the Yangtze River Basin of China. However,the immaturity of its stable transformation system and its low transformation efficiency limit gene function research on non-heading Chinese cabbage. Agrobacterium rhizogenes-mediated(ARM) transgenic technology is a rapid and effective transformation method that has not yet been established for non-heading Chinese cabbage plants. Here, we optimized conventional ARM approaches(one-step and two-step transformation methods) suitable for living non-heading Chinese cabbage plants in nonsterile environments. Transgenic roots in composite non-heading Chinese cabbage plants were identified using phenotypic detection, fluorescence observation, and PCR analysis. The transformation efficiency of a two-step method on four five-day-old non-heading Chinese cabbage seedlings(Suzhouqing, Huangmeigui, Wuyueman, and Sijiu Caixin) was 43.33%-51.09%, whereas using the stout hypocotyl resulted in a transformation efficiency of 54.88% for the 30-day-old Sijiu Caixin.The one-step method outperformed the two-step method;the transformation efficiency of different varieties was above 60%, and both methods can be used to obtain transgenic roots for functional studies within one month. Finally, optimized ARM transformation methods can easily,quickly, and effectively produce composite non-heading Chinese cabbage plants with transgenic roots, providing a reliable foundation for gene function research and non-heading Chinese cabbage genetic improvement breeding. 展开更多
关键词 Agrobacterium rhizogenes Non-heading Chinese cabbage Transgenic roots Composite plant transformation efficiency
下载PDF
Defect Detection Model Using Time Series Data Augmentation and Transformation
9
作者 Gyu-Il Kim Hyun Yoo +1 位作者 Han-Jin Cho Kyungyong Chung 《Computers, Materials & Continua》 SCIE EI 2024年第2期1713-1730,共18页
Time-series data provide important information in many fields,and their processing and analysis have been the focus of much research.However,detecting anomalies is very difficult due to data imbalance,temporal depende... Time-series data provide important information in many fields,and their processing and analysis have been the focus of much research.However,detecting anomalies is very difficult due to data imbalance,temporal dependence,and noise.Therefore,methodologies for data augmentation and conversion of time series data into images for analysis have been studied.This paper proposes a fault detection model that uses time series data augmentation and transformation to address the problems of data imbalance,temporal dependence,and robustness to noise.The method of data augmentation is set as the addition of noise.It involves adding Gaussian noise,with the noise level set to 0.002,to maximize the generalization performance of the model.In addition,we use the Markov Transition Field(MTF)method to effectively visualize the dynamic transitions of the data while converting the time series data into images.It enables the identification of patterns in time series data and assists in capturing the sequential dependencies of the data.For anomaly detection,the PatchCore model is applied to show excellent performance,and the detected anomaly areas are represented as heat maps.It allows for the detection of anomalies,and by applying an anomaly map to the original image,it is possible to capture the areas where anomalies occur.The performance evaluation shows that both F1-score and Accuracy are high when time series data is converted to images.Additionally,when processed as images rather than as time series data,there was a significant reduction in both the size of the data and the training time.The proposed method can provide an important springboard for research in the field of anomaly detection using time series data.Besides,it helps solve problems such as analyzing complex patterns in data lightweight. 展开更多
关键词 Defect detection time series deep learning data augmentation data transformation
下载PDF
Mucosa color and size may indicate malignant transformation of chicken skin mucosa-positive colorectal neoplastic polyps
10
作者 Ying-Jie Zhang Meng-Xia Yuan +5 位作者 Wu Wen Fan Li Yi Jian Chuan-Ming Zhang Ye Yang Feng-Lin Chen 《World Journal of Gastrointestinal Oncology》 SCIE 2024年第3期750-760,共11页
BACKGROUND Lipid metabolism reprogramming is suspected to exist in pre-cancerous lesions,including colorectal adenoma.Screening colonoscopy frequently reveals chicken skin mucosa(CSM;white or yellow-white speckled muc... BACKGROUND Lipid metabolism reprogramming is suspected to exist in pre-cancerous lesions,including colorectal adenoma.Screening colonoscopy frequently reveals chicken skin mucosa(CSM;white or yellow-white speckled mucosa)surrounding colo-rectal polyps,caused by macrophages engulfing and accumulating the lipids decomposed by colon cells or adjacent tumors.CSM-positive colorectal polyps are associated with various diseases;however,their prognosis varies greatly.Cold snare polypectomy is commonly used to resect lesions up to 10 to 15 mm in diameter without signs of submucosal invasion but is controversial for CSM-positive colorectal polyps.Improved imaging is required to diagnose and treat CSM-positive colorectal polyps.METHODS This retrospective cohort study included 177 patients with CSM-positive colorectal polyps diagnosed using endoscopy.All patient-related information was extracted from the Goldisc soft-clinic DICOM system or electronic medical record system.Based on the pathological results,patients were classified as non-neoplastic polyps(five juvenile polyps),neoplastic polyps,non-invasive high-grade neoplasia(NHGN),or submucosal invasive carcinoma(SM stage cancer).We analyzed and compared the clinical features,suspected risk factors for malignant transformation of neoplastic polyps,and early infiltration of sub-mucosal carcinoma.RESULTS The diameters of NHGN and SM polyps were much smaller than those of neoplastic polyps.Most NHGN polyps had a deeper red mucosal color.On logistic regression analyses,diameter and deeper red mucosal color were independent risk factors for malignant transformation of neoplastic polyps.Type 1 CSM was more common in high-grade intraepithelial neoplasia and SM;type 2 CSM was more common in neoplastic polyps.Logistic regression analyses revealed no significant differences in the malignant transformation of neoplastic polyps or early submucosal invasion of CSM-positive colorectal cancer.Changes in the CSM mucosa surrounding neoplastic polyps and submucosal invasion of colorectal cancer disappeared within 12 months.No tumor recurrence was found during either partial or complete endoscopic resection of the CSM.CONCLUSION CSM-positive colorectal polyps>1 cm in diameter or with deeper red mucosa may be related to NHGN.Resection of CSM surrounding colorectal adenomas did not affect tumor recurrence. 展开更多
关键词 Chicken skin mucosa Colorectal cancer Colorectal polyps Endoscopic resection Malignant transformation White light endoscopy
下载PDF
Research on Pathways of How Digital Transformation Affects the Business Performance of MEEC Enterprises in Chengdu
11
作者 Zhu Yurong Luo Ziling 《Contemporary Social Sciences》 2024年第1期99-121,共23页
This paper aims to examine the impact of digital transformations on the business performance of the meetings,expositions,events,and conventions(MEEC)industry in Chengdu by conducting an empirical analysis of 68 MEEC e... This paper aims to examine the impact of digital transformations on the business performance of the meetings,expositions,events,and conventions(MEEC)industry in Chengdu by conducting an empirical analysis of 68 MEEC enterprises in the city.The study employed the fuzzy-set qualitative comparative analysis(fsQCA)method to explore the pathways and factors involved.Drawing on the theory of synergetics,nine condition variables were carefully selected from four dimensions:digital technologies,digital strategy,digital infrastructure,and digital innovation.The findings revealed that digital transformations were an intricate systematic process,whereby a single factor alone did not serve as a necessary condition for MEEC enterprises to achieve high business performance.The analysis identified five distinct pathways that would lead to high performance,which can be categorized into three distinct models:the“organization-human resources”dominated model,the“human resources-infrastructure”driven model,and the multi-factor coordination model.The analysis also identified two pathways that would result in low performance,categorized as the“basic condition absent”model.Notably,there was substantial heterogeneity observed in the configurational pathways in terms of the magnitude of the impact of digital transformation on business performance across MEEC enterprises of different sizes.This paper suggests that the government should assume the role of a platform,providing policy and financial support to MEEC enterprises to help guide them through the process of digital transformation and that MEEC enterprises themselves should seize the opportunities arising from digital transformation to strengthen their digital infrastructure construction,human resources development,and innovation in brand building.This study presents empirical evidence that contributes to the understanding of the transformation process of MEEC enterprises within the digital economy era,as well as valuable insights into understanding the channels and internal conditions involved in digital transformations. 展开更多
关键词 MEEC enterprises business performance fsQCA digital transformation
下载PDF
Performance Evaluation of Low-Carbon and Clean Transformation of China’s Coal Economy
12
作者 Liangfeng Zhu 《Journal of Environmental Science and Engineering(B)》 2024年第1期21-38,共18页
In China,the oversupply of coal occurred in 2009,and from that year onwards,China’s coal economy began a low-carbon and clean transformation.Evaluating transformation performance is the research goal of this paper.Th... In China,the oversupply of coal occurred in 2009,and from that year onwards,China’s coal economy began a low-carbon and clean transformation.Evaluating transformation performance is the research goal of this paper.The data collection for this paper includes data on deep processing of Chinese coal products from 2009 to 2020,as well as data on asset structure evolution and financial performance of 34 listed companies in the Chinese coal mining.Entropy value method is used to calculate the entropy value of low-carbon transformation,and the regression analysis is used to study the performance of cleaner transformation,the conclusion is as follows:(1)From 2009 to 2020,in China’s total energy consumption,coal consumption accounted for 71.6%in 2009 and 56.8%in 2020,the goals set by the state have been achieved.(2)The national goal of reducing the proportion of coal consumption and reducing carbon emissions has forced the transformation of deep processing of coal products.The transformation of coal enterprises towards low-carbon and clean production has achieved remarkable results.(3)From 2009 to 2020,the non coal industry income of 34 listed companies in China’s coal mining industry increased by 8.21%annually.At the same time,the asset structure was adjusted,and nearly 80%of the asset structure evolution showed an orderly development trend.(4)The regression analysis results show that the entropy value of coal deep processing products and the entropy value of asset structure adjustment are significantly related to transformation performance.The paper proposes to summarize the successful experience of China’s coal energy economic transformation,lay a foundation for achieving the carbon peak and carbon neutral goals in the future,further increase the intensity of coal deep processing,increase the proportion of clean energy in total energy consumption,and strive to control asset operation towards the goal of increasing the proportion of non coal industry income. 展开更多
关键词 Coal economy low-carbon and clean transformation deep processing of coal evolution of asset structure performance appraisal
下载PDF
Observation about the Classical Electromagnetic Gauge Transformation and Its Quantum Correspondence
13
作者 Gustavo V. López Jorge A. Lizarraga 《Journal of Modern Physics》 2024年第4期474-479,共6页
Using the Landau and symmetric gauges for the vector potential of a constant magnetic field and the quantum problem of a charged particle moving on a flat surface, we show the classical electromagnetic gauge transform... Using the Landau and symmetric gauges for the vector potential of a constant magnetic field and the quantum problem of a charged particle moving on a flat surface, we show the classical electromagnetic gauge transformation does not correspond to a one-dimensional unitary group transformation U(1) of the wave function for the quantum case. In addition, with the re-examination of the relation between the magnetic field B and its vector potential  A, we found that, in order to have a consistent formulation of the dynamics of the charged particle with both expressions, we must have that B=∇×A if and only if B≠0. 展开更多
关键词 Gauge transformation Harmonic Oscillator Quantum Hall Effect Electromagnetic Potentials
下载PDF
Advances in the Mechanisms of Hemorrhagic Transformation and Therapeutic Agents after Intravenous Thrombolysis in Ischemic Stroke
14
作者 Yue Dai Yongyi Zhan +2 位作者 Mingtian Lu Zehua He Yu Liu 《Yangtze Medicine》 2024年第1期29-40,共12页
Ischemic stroke is an important disease leading to death and disability for all human beings, and the key to its treatment lies in the early opening of obstructed vessels and restoration of perfusion to the local infa... Ischemic stroke is an important disease leading to death and disability for all human beings, and the key to its treatment lies in the early opening of obstructed vessels and restoration of perfusion to the local infarcted area. Intravenous thrombolysis with tissue plasminogen activator (tPA) is one of the effective therapies to achieve revascularization, but it faces strict indications with a narrow therapeutic time window, and significantly increases the incidence of hemorrhagic transformation, HT, after reperfusion of the infarcted foci, which greatly reduces the incidence of patients with ischemic stroke. which significantly increases the incidence of hemorrhagic transformation (HT) after reperfusion of the infarcted focus, greatly reducing patient utilization and clinical benefit. Since the mechanism of HT has not been fully elucidated, and the related molecular mechanisms are complex and interactive, there is no specific and effective therapy to avoid the occurrence of HT. In this article, we focus on the research progress on the mechanism of HT after tPA intravenous thrombolysis in ischemic stroke patients from the aspects of vascular integrity disruption, oxidative stress, and neuroinflammatory response and the corresponding therapeutic strategies, in order to improve the safety and prognosis of tPA intravenous thrombolysis in the clinic. 展开更多
关键词 Hemorrhagic transformation Tissue-Type Fibrinogen Activator Acute Ischemic Stroke Blood-Brain Barrier
下载PDF
An Exploration of Organizational Development in the Process of Innovation and Transformation of Pharmaceutical Enterprises-Taking X Pharmaceutical Enterprise as an Example
15
作者 Gao Lin Sun Lihua 《Asian Journal of Social Pharmacy》 2024年第1期72-80,共9页
Objective To study how to promote the smooth innovation and transformation of enterprises and enhance the market competitiveness of enterprises from the perspective of human resources organization development.In the w... Objective To study how to promote the smooth innovation and transformation of enterprises and enhance the market competitiveness of enterprises from the perspective of human resources organization development.In the wave of pharmaceutical industry reform,some entrepreneurs realize the importance of innovation and technology in the future.However,domestic pharmaceutical enterprises are still in the production-oriented stage.In the process of transformative innovation,pharmaceutical enterprises should not only rely on the support of scientific and technological and economic forces,but also need a suitable organizational change and many excellent talents as the source of development.Methods Through retrieving relevant literature and combined with the organizational development practice of X pharmaceutical enterprise,the organizational development model was explored in this paper.Results and Conclusion By forming a system of strategy,organization,talent,culture and mechanism,and building an organizational development model,we can improve the organizational atmosphere and organizational efficiency in the process of enterprise innovation and transformation,so as to enhance the competitiveness of enterprises in the market. 展开更多
关键词 innovation transformation organization development organizational culture personnel training
下载PDF
Research on the Digital Transformation of the Whole Industry Chain of Guangdong Supply and Marketing Cooperative
16
作者 Siting Lian Wei Zhang 《Proceedings of Business and Economic Studies》 2024年第1期76-82,共7页
Guangdong Supply and Marketing Cooperative serves as an important institution for the“Three Rural Areas”in the Guangdong-Hong Kong-Macao Greater Bay Area.Its digital transformation and optimization serve as powerful... Guangdong Supply and Marketing Cooperative serves as an important institution for the“Three Rural Areas”in the Guangdong-Hong Kong-Macao Greater Bay Area.Its digital transformation and optimization serve as powerful supports for rural revitalization.This paper systematically reviews the main practices and effectiveness of the digital transformation within the Guangdong Supply and Marketing Cooperative.It also analyzes the current development dilemmas faced in the construction of digital supply and marketing.Additionally,it proposes targeted solutions,including building a big data resource base,optimizing the digital supply and marketing cloud platform,developing digital publictype agricultural social service applications,establishing a new model of rural e-commerce,enhancing the traceability management system for agricultural products,and strengthening the construction of the digital human resources system.These proposals aim to further promote the strategy for revitalizing the countryside. 展开更多
关键词 Guangdong supply and marketing cooperative Digital transformation Whole industry chain Rural revitalization
下载PDF
Gender and rural transformation:A systematic literature review 被引量:1
17
作者 Maria Fay ROLA-RUBZEN Hue T.VUONG +4 位作者 Claire DOLL Curtis ROLLINS Jon Marx SARMIENTO Mohammad Jahangir ALAM Ismat Ara BEGUM 《Journal of Integrative Agriculture》 SCIE CAS CSCD 2023年第12期3624-3637,共14页
Rural transformation can improve poverty reduction,living standards,and health outcomes in developing countries.However,impacts associated with rural transformation vary by region,household,and individual trait(includ... Rural transformation can improve poverty reduction,living standards,and health outcomes in developing countries.However,impacts associated with rural transformation vary by region,household,and individual trait(including gender).While research on rural transformation has been increasing over the last decade,there has been no comprehensive review conducted on the relationships between gender and rural transformation.Here,we conduct a systematic literature review to investigate the impacts of rural transformation on gender and the influence of gender inclusiveness on rural transformation.We reviewed 82 studies from 1960-2021 that explore the relationships between rural transformation and gender.We then developed a framework that captures incidences and flow directions between indicators.Results show that most studies examined the impacts of rural transformation on women and between gender indicators.Few investigated the role of women and the influence of gender inclusiveness on rural transformation.Overall,studies showed that rural transformation typically leads to positive outcomes for women regarding employment,income,and empowerment.However,negative impacts on women’s control over income,stability of new income sources,and access to healthy food are also common.Tailoring future development policies and programs to explicitly account for gender inclusiveness can lead to more successful rural transformation. 展开更多
关键词 GENDER rural transformation structural transformation women’s empowerment
下载PDF
A review of rural transformation studies:Definition,measurement,and indicators 被引量:1
18
作者 Dong WANG Chunlai CHEN Christopher FINDLAY 《Journal of Integrative Agriculture》 SCIE CAS CSCD 2023年第12期3568-3581,共14页
The paper reviews studies of rural transformation in three dimensions-definition,measurement,and indicators-and summarises the findings of rural transformation research.The scope of rural transformation includes four ... The paper reviews studies of rural transformation in three dimensions-definition,measurement,and indicators-and summarises the findings of rural transformation research.The scope of rural transformation includes four elements-productivity,rurality,inclusiveness,and sustainability.Current concepts of the dimensions of rural transformation and their associated indicators are insufficient for policy decision-making,as they lack objectivity,feasibility,accountability,comprehensiveness,and comparability.Future research to develop new measures to assess rural transformation in developing countries is valuable.Furthermore,there is potential to explore the topic in some directions:urbanisation strategy,public intervention(i.e.,institution,policy,and investment),gender inclusiveness,market creation,and international trade. 展开更多
关键词 rural transformation agricultural transformation structural change
下载PDF
Diffusionless-Like Transformation Unlocks Pseudocapacitance with Bulk Utilization: Reinventing Fe_(2)O_(3) in Alkaline Electrolyte 被引量:1
19
作者 Taowen Dong Wencai Yi +10 位作者 Ting Deng Tingting Qin Xianyu Chu He Yang Lirong Zheng Seung Jo Yoo Jin-Gyu Kim Zizhun Wang Yan Wang Wei Zhang Weitao Zheng 《Energy & Environmental Materials》 SCIE EI CAS CSCD 2023年第1期145-154,共10页
Energy density can be substantially raised and even maximized if the bulk of an electrode material is fully utilized.Transition metal oxides based on conversion reaction mechanism are the imperative choice due to eith... Energy density can be substantially raised and even maximized if the bulk of an electrode material is fully utilized.Transition metal oxides based on conversion reaction mechanism are the imperative choice due to either constructing nanostructure or intercalation pseudocapacitance with their intrinsic limitations.However,the fully bulk utilization of transition metal oxides is hindered by the poor understanding of atomic-level conversion reaction mechanism,particularly it is largely missing at clarifying how the phase transformation(conversion reaction)determines the electrochemical performance such as power density and cyclic stability.Herein,α-Fe_(2)O_(3) is a case provided to claim how the diffusional and diffusionless transformation determine the electrochemical behaviors,as of its conversion reaction mechanism with fully bulk utilization in alkaline electrolyte.Specifically,the discharge productα-FeOOH diffusional from Fe(OH)2 is structurally identified as the atomic-level arch criminal for its cyclic stability deterioration,whereas the counterpartδ-FeOOH is theoretically diffusionless-like,unlocking the full potential of the pseudocapacitance with fully bulk utilization.Thus,such pseudocapacitance,in proof-of-concept and termed as conversion pseudocapacitance,is achieved via diffusionless-like transformation.This work not only provides an atomic-level perspective to reassess the potential electrochemical performance of the transition metal oxides electrode materials based on conversion reaction mechanism but also debuts a new paradigm for pseudocapacitance. 展开更多
关键词 bulk utilization conversion pseudocapacitance diffusionless transformation Fe_(2)O_(3) phase transformation
下载PDF
Dynamic scaling characteristics of single-phase natural circulation based on different strain transformations
20
作者 Jia-Ning Xu Xiang-Bin Li +3 位作者 Zhong-Yi Wang Yu-Sheng Liu De-Chen Zhang Qiao Wu 《Nuclear Science and Techniques》 SCIE EI CAS CSCD 2023年第9期128-141,共14页
To understand the dynamical system scaling(DSS)analysis theory,the applicability of DSSβ-andω-strain transformation methods for the scaling analysis of complex loops was explored.A simplified model consisting of two... To understand the dynamical system scaling(DSS)analysis theory,the applicability of DSSβ-andω-strain transformation methods for the scaling analysis of complex loops was explored.A simplified model consisting of two loops was established based on the primary and secondary sides of a nuclear reactor,andβ-andω-strain transformation methods were used to ana-lyze the single-phase natural circulation in the primary circuit.For comparison with the traditional method,simplified DSSβ-andω-strain methods were developed based on the standard scaling criterion.The strain parameters in these four methods were modified to form multiple groups of scaled-down cases.The transient process of the natural circulation was simulated using the Relap5 code,and the variation in the dynamic flow characteristics with the strain numbers was obtained using different scaling methods.The results show that both the simplified and standard DSS methods can simulate the dynamic characteristics of natural circulation in the primary circuit.The scaled-down cases in the simplified method exhibit the same geometric scaling and correspond to small core power ratios.By contrast,different scaled-down cases in the standard DSS method correspond to different geometric scaling criteria and require more power.The dynamic process of natural circula-tion can be simulated more accurately using the standard DSS method. 展开更多
关键词 Dynamical system scaling analysis β-strain transformation ω-strain transformation Natural circulation
下载PDF
上一页 1 2 250 下一页 到第
使用帮助 返回顶部