Subjects: Nuclear Science and Technology >> Other Disciplines of Nuclear Science submitted time 2024-07-10
Abstract： [Background] Uranium polymetallic ores are strategic emerging industry minerals, and the quantitative analysis of uranium (U) in ores is a crucial step in the development process of such ores. [Purpose] In this paper, a quantitative analysis of U in uranium polymetallic ores using femtosecond laser-induced breakdown spectroscopy (LIBS) combined with partial least squares regression (PLSR) modeling was conducted. [Methods] Initially, the concentrations of U in six samples were measured by high-purity germanium gamma spectrometer and set as reference values. Then femtosecond lasers were employed to ablate the samples to obtain LIBS spectra. Subsequently, two normalization methods were applied to preprocess the raw spectra, and the impact of the preprocessed spectra on PLS model prediction analysis was compared with that of the raw spectra. Subsequently, the spectral data from five sets of samples were utilized as a training dataset to construct a quantitative model, enabling the analysis and prediction of U concentration in sample 3# [Results] The results indicate that the relative standard deviation (RSD) and mean relative error (MRE) of 10 predicted values for sample 3# are merely 5.94% and 4.73%, respectively. [Conclusions] This demonstrates that the combination of PLSR algorithm and femtosecond LIBS exhibits high analytical accuracy and stability for samples. This finding can provide significant reference for practical applications of femtosecond LIBS technology in the quantitative analysis of U content in uranium polymetallic ores.
Subjects: Nuclear Science and Technology >> Other Disciplines of Nuclear Science submitted time 2024-07-01
Abstract： [Background]: Uranium polymetallic ores are strategic emerging industry minerals, and the quantitative analysis of uranium (U) in ores is a crucial step in the development process of such ores. [Purpose]: In this paper, a quantitative analysis of U in uranium polymetallic ores using femtosecond laser-induced breakdown spectroscopy (LIBS) combined with partial least squares regression (PLSR) modeling was conducted. [Methods]: Initially, the concentrations of U in six samples were measured by high-purity germanium gamma spectrometer and set as reference values, and then femtosecond lasers were employed to ablate the samples to obtain LIBS spectra. Subsequently, two normalization methods were applied to preprocess the raw spectra, and the impact of the preprocessed spectra on PLS model prediction analysis was compared with that of the raw spectra. Subsequently, the spectral data from five sets of samples were utilized as a training dataset to construct a quantitative model, enabling the analysis and prediction of U concentration in sample 3# [Results]: The results indicate that the relative standard deviation (RSD) and mean relative error (MRE) of 10 predicted values for sample 3# are merely 5.94% and 4.73%, respectively. [Conclusions]: This demonstrates that the combination of PLSR algorithm and femtosecond LIBS exhibits high analytical accuracy and stability for samples. This finding can provide significant reference for practical applications of femtosecond LIBS technology in the quantitative analysis of U content in uranium polymetallic ores.
Subjects: Biology >> Botany >> Applied botany submitted time 2023-12-26 Cooperative journals: 《广西植物》
Abstract： Glinous sorghum is an important raw material for the production of baijiu. During its growth process, glinous sorghum requires a substantial amount of chemical fertilizers. As an environmentally friendly fertilizer, microbial agent has great prospects in future. The aim of this paper is to develop a growth promoting microbial agent for glutinous sorghum. In this study, the glutinous sorghum leaves were used as experimental materials to isolate and screen microbial strains with plant growth hormone IAA (indole acetic acid) production ability. Phylogenetic analysis was performed to determine the taxonomic status of these microbial strains based on the 16S rDNA conserved sequences. The effects of the strains on glutinous sorghum seed germination was analyzed by soaking the seeds with bacterial suspension. The effect of strain on the sorghum seedlings growth was analyzed by pot experiment. The results were as follows: (1) Four microbial strains capable of producing IAA were isolated and screened from glutinous sorghum leaves, designated as HY1-1, HY1-2, HY1-3, and HY1-4. Among them, HY1-1 exhibited the highest IAA production per unit concentration which was 2.56 mol·L-1. (2) Bayesian inference tree analysis based on the 16S rDNA sequences revealed that all four strains belonged to Bacillus subtilis. (3) HY1-1, HY1-2, HY1-3, and HY1-4 could promote the glutinous sorghum seed germination rates. Compared to the control groups, the germination rates of glutinous sorghum seeds soaked in bacterial suspension significantly increased by 40.04% to 165.52%. Among them, HY1-1 demonstrated the most prominent promotion effect, with a germination rate increase of 165.52%. (4) HY1-1 strain was selected for a pot experiment. After 30 days of inoculation on the roots of glutinous sorghum seedlings, the stem heights of the seedlings significantly increased by 29.17%, and total phosphorus content increased significantly by 5.12%. The rhizosphere substrate of glutinous sorghum exhibited a significant increase in available nitrogen content by 31.70% and available phosphorus content by 28.88%. B. subtilis HY1-1, an endophytic bacterium in glutinous sorghum leaves, can promote the growth of glutinous sorghum plants by secreting the plant growth hormone IAA and providing necessary nutrients. This study provides genetic resources for the further development of microbial agents targeting the growth promotion of glutinous sorghum.
Subjects: Medicine, Pharmacy >> Clinical Medicine submitted time 2023-10-12
Xia，qingqing
Chen，Jingyan
Sun，qin
Liu，yaoxia
Ren，min
Liu，yang
Cao，xiaohong
Tang，xialian
Li，yongling
zhang， min
Abstract： Objective：This study compared the effects of dapagliflozin and linagliptin on weight and body composition in elderly T2DM patients who had already been treated with metformin for poor blood sugar control.
Methods：Totally 106 elderly patients with type 2 diabetes who had received metformin treatment and had HbA1c levels of more than 7.0% were randomly divided into dapagliflozin and linagliptin groups. Bioimpedance analysis was used to assess body composition before and after the study.
Results：The average body weight change from baseline to 24 weeks in the dapagliflozin group was -3.78 kg . Dapagliflozin also significantly reduced muscle massand total body protein. Compared with linagliptin, dapagliflozin resulted in a greater decrease in body fat mass from baseline to week 24, the statistical difference was significant.
Conclusion：Dapagliflozin significantly reduces body weight, including body fat and lean weight, and should be used with caution in elderly frail patients.
Peer Review Status:
Awaiting Review
Subjects: Medicine, Pharmacy >> Clinical Medicine submitted time 2023-10-10
Abstract： Abstract：
Objective To evaluate the effect of dawn phenomenon (DP) and glucose variability on cognitive function of elderly patients with type 2 diabetes mellitus, and to explore the correlation and risk factors between dawn phenomenon and cognitive dysfunction.
Methods The patients were divided into DP group (18 cases) by Flash Glucose Monitoring data, and the NDP group (18 cases) was matched according to age, gender, HbA1c and education level. The glucose level, glucose variability and cognitive function of the two groups were compared by paired t test; The correlation between cognitive dysfunction and other indicators were analyzed by person correlation analysis and stepwise multiple linear regression.
Results There were statistically significant differences in TIR, TAR, SD, MBG, CIMT and MoCA scores between two groups (P < 0.05). Correlation analysis showed that cognitive impairment was negatively correlated with age, tar, SD, MBG, CIMT (r=0.509, -0.338, -0.341, -0.341*, -0.345*, p<0.05), Stepwise multiple linear regression analysis suggested that age and SD were the risk factors of cognitive dysfunction. Conclusion Elderly type 2 diabetic patients with dawn phenomenon have higher blood glucose level, increased blood glucose fluctuation, and increased degree of atherosclerosis, which are more likely to lead to cognitive impairment.
Peer Review Status:Awaiting Review
Subjects: Medicine, Pharmacy >> Clinical Medicine submitted time 2023-09-22 Cooperative journals: 《中国全科医学》
Abstract： Ensuring the quality of general practice faculty is not only an important basis for training qualified general practitioners，but also relates to the relationship between general practice and other professional disciplines，which is an important guarantee for improving the status of general practice and promoting the development of general practice. This article summarizes the roles and functions，admission standards，quality evaluation standards，and certification standards of general practice faculty by reviewing the websites and literature related to the training of general practitioners and general practice teachers at home and abroad，and prospects the quality evaluation and certification indicator system for general practice teachers in our country in the future，suggests that a quality evaluation and certification indicator system for general practice teachers should be constructed and adapted to national conditions in China，an authoritative professional committee for general practice teachers should be established，the standards for the admission，evaluation and assessment of general practice teachers should be formulated，and a systematic and complete management system for the training of general practice teachers should be established. This paper also suggests to select 1 or 2 excellent general practice faculty training bases in each province，to establish a relatively fixed and high-quality team of general practice faculty，which can provide a useful reference for the continuous quality improvement of general practice faculty training in China.
Subjects: Library Science，Information Science >> Library Science submitted time 2023-08-27 Cooperative journals: 《图书情报工作》
Abstract： [Purpose/significance] An in-depth systematic analysis of information encounter behavior can promote academic innovation in this field and application innovation in related information services.[Method/process] Using CNKI and Web of Science as data sources, a systematic review method was used to analyze the most representative 41 literatures in the field. In the research section of the knowledge vein, this paper systematically analyzed and summarized the theoretical models, research methods and influencing factors. In the forefront perspective, the process of encountering information is broken down into three stages:before encounter, during encounter, and after encounter. Then, the paper summed up the study of encountering follow-up behavior.[Result/conclusion] Information encounter behavior is the result of the combined effects of information, individuals, technology, and the environment. The use of encounter information is currently a research hotspot. Research on information encounter based on the information search process chain, research based on the mobile Internet, research based on objective data, and cross-discipline research are hot topics that are feasible in the future.
Subjects: Library Science，Information Science >> Library Science submitted time 2023-08-27 Cooperative journals: 《图书情报工作》
Abstract： [Purpose/significance] Empirical research is an important part of users' online health information help-seeking behaviour research, and its in-depth analysis can promote the application innovation and pattern innovation of online health information service. [Method/process] This paper takes CNKI and Web of Science as the data source to obtain the representative research documents. Systematic review method is used to comb the related empirical research literature of users' online health information help-seeking behaviour both at home and abroad. [Result/conclusion] Existing studies have initially formed a framework of knowledge systems. However, there are still many research gaps. The influencing factors mainly include internal factors (help-seeking items, help-seeker factors), external factors (information environment, social environment, aid provider factors), mediators (help-seeking demands, cognitive factors), and moderators (demographic factors). In the future, focusing on research foundation, mining influencing factors, paying attention to outcome variables, and promoting data-driven research will be the focus and hotspot.
Subjects: Library Science，Information Science >> Library Science submitted time 2023-07-26 Cooperative journals: 《图书情报工作》
Abstract： [Purpose/significance] Intermittently discontinuous behavior is an important part of the passive behavior of social network users. This paper makes an analysis of the research results at home and abroad, systematically sorts out its knowledge system and key issues of research in this field, and forecasts the future research trend accordingly, which can provide some reference for the follow-up academic research.[Method/process] With CNKI and Web of Science as the data sources, this paper obtains 54 representative research related to this fields through keywords retrieval, tracing retrieval and subject analysis, adopts the method of systematic review to integrate knowledge base through three key issues, including research topic, research theory and research method, and constructs the framework of normative research process based on this.[Result/conclusion] The study of users' intermittently discontinuous behavior in the context of social network is in the initial stage, and a large space remains for further study in terms of the subdivision degree of research topics, the richness of theory models and the diversity of research methods. Based on the interdisciplinary perspectives of information science, psychology, sociology, journalism and communication, it will be a future research trend to deeply explore the influencing factors and formation mechanism of social network users' intermittently discontinuous behaviour from the perspectives of two-way balance of promoting factors and inhibiting factors as well as comprehensive effect of external social environment and psychological and emotional experience.
Subjects: Library Science，Information Science >> Information Science submitted time 2023-04-01 Cooperative journals: 《图书情报工作》
Abstract： [Purpose/significance] In view of the problem that it's difficult for researchers to find valuable information from large amounts of scientific and technological information in the Web, this paper constructs a comprehensive calculation method for information value. It can calculate the information value of Web technology information and help researchers find Web technology information of information value quickly and accurately.[Method/process] Taking overall consideration of the external feature and textual semantic feature of the information, this paper used deep learning (pretrained language model) BERT to construct information value calculation model based on the textual semantic feature, used the predictive output of the deep learning model to complete the scoring, and combined the original calculation method of the external feature of the information to get the final information value score.[Result/conclusion] The experimental results show that the information value calculation model based on the textual semantic feature can rank the information to different levels according to their information value score, which makes up for the problem of poor star differentiation in the original calculation method only based on the external feature of the information. And the final comprehensive evaluation results show that the information value calculation model proposed in this paper can also meet the needs of researchers in the practical application.
Subjects: Library Science，Information Science >> Information Science submitted time 2023-04-01 Cooperative journals: 《图书情报工作》
Abstract： [Purpose/significance] With the development of digitization and informatization, digital resources are playing an increasingly important role. Understanding the databases usage characteristics of faculties will be beneficial to optimize the construction of digital resources and promote the construction of "double first-class" universities. [Method/process] This paper selected Fudan University Library (FUL) as the research object to explore the relevance of databases utilization in library, subjects and facultiesthrough the methods of questionnaire survey, social network and cluster analysis by Leiden algorithm. [Result/conclusion] The results indicate that the homogeneous departments and databases are formed a cluster, the evolution of interdiscipline promotes the usage of specialized databases by the researchers from other major. In the future construction of E-resources, libraries can optimize the procurement of E-resources and discipline service according to the combination of cluster characteristics of disciplines and departments in the utilization of E-resources, and the statistical result based on COUNTER.
Subjects: Library Science，Information Science >> Information Science submitted time 2023-04-01 Cooperative journals: 《图书情报工作》
Abstract： [Purpose/significance] The status and the historical process of emotion research in the field of Library and Information Science (LIS) were analyzed systematically, to identify the core authors and papers on the scope of the topic, summarize related research framework and characteristics, and anticipate the future research trend.[Method/process] Based on the literature of LIS emotion research in the databases of Web of Science, LISA and Google Scholar, the citation data was mined and analyzed by HistCite, and content analysis method was used to build the emotion research framework.[Result/conclusion] The emotion research in LIS is in a period of rapid development, the emotion research of human-computer interaction, IT use and information behaviors are the directions that LIS scholars pay more attention to them, and users' emotion tendency identification in the social network environment is a hot research direction. The emotion research in LIS still has problems such as hysteretic theoretical development, mixed terminology and classification system that need to be broken through.
Subjects: Materials Science >> Materials Science (General) submitted time 2023-03-31 Cooperative journals: 《材料研究学报》
Abstract： Fusion weld of TA1/X80 composite plate was carried out by taking foils of TiNi, and NiCrMo as the double transition layer weld material. Then the microstructure, morphology, chemical and phase composition and mechanical properties of the weld metal were characterized by means of metallography, SEM, EDS, XRD. Results revealed that the weld seam with TA1/TiNi weld metal exhibited a microstructure with equiaxed grains, and the Ti content drastically descended along a line from TA1 side to TiNi side while Ni content gradual increases. The weld seam with TiNi/NiCrMo exhibited a dendritic microstructure and there existed a 40 μm wide transitional zone, and the Ti content rapidly reduced along a line from TiNi side to NiCrMo side, while Ni content decreased first and then restored, but Cr and Mo increased gradually. The weld seam of NiCrMo/X80 showed a mixed grain- and acicular- like microstructure, and the Fe content increased sharply at the interface. while the Ni content and Cr content reduced dramatically along a line from the NiCrMo side to the X80 side. The strength and toughness of welded joint are lower than that of the base metal area due to that there existed a certain number of brittle phases in the weld seams with TiNi and NiCrMo.
Subjects: Materials Science >> Materials Science (General) submitted time 2023-03-18 Cooperative journals: 《材料研究学报》
Abstract： The influence of addition of alloying elements of medium carbon Fe-Mn and Ni in the welding flux on the microstructure and toughness of the weld seam of FV520(B) steel was investigated by means of impact test, metallographic microscope, SEM and X-ray diffractometer. The results show that the microstructure of the weld seam of FV520(B) steel mainly composed of tempered sorbite and lath martensite with some residual austenite and secondary phases. With the increasing amount of alloying elements Mn and Ni, the microstructure of weld seam became finer, and the lamellae of martensite became thinner and distributed more uniformly. The addition of allying elements into a basic flux rather than an acidic ones showed much higher effectiveness in improvement of the toughness of the weld seam. The induced Mn and Ni can enhance the austenitic amount in the weld seam, which in turn plays an important role in enhancing its toughness. Moreover, the induced Ni rather than Mn was more effective in enhancing the toughness of the weld seam.
Subjects: Materials Science >> Materials Science (General) submitted time 2023-03-18 Cooperative journals: 《材料研究学报》
Abstract： The low carbon bainite steel was welded by double-sided submerged arc welding and the microstructure and low temperature toughness of the joints was studied by optical microscope and PSW750 instrumented impact testing machine. The results show that the microstructure of the weld seam consisted of acicular ferrite and granular bainite, however the HAZ shows a microstructure consisted of bainite ferrite and granular bainite. The hardness at HAZ near the weld bond is the highest and then decreases gradually approaching to the hardness of base metal. In comparison to the matrix the weld seam and HAZ show a lower toughness with a ductile brittle transition temperature at -20℃and -60℃ respectively, which may be ascribed to the occurrence of solidification segregation, highly concentrated dislocations and formation of carbon nitrides of alloying elements such as Ti and Mo at grain boundaries etc.in the weld joints during rapid cooling after welding.
Subjects: Biology >> Botany submitted time 2022-10-27 Cooperative journals: 《广西植物》
Abstract： Oriental cherries are famous ornamental plants worldwide. Floral coloration is the most prominent trait of cherry. In order to analyzes the differences pathways and key metabolite in flower color between Prunus serrulata cultivars, we conducted a comparative analysis of anthocyanin metabolomics between white, green, and pink cherry cultivars using LC-MS/MS. The results were as follows: (1) A total of 42 anthocyanins were detected, mainly including petunidin, delphinidin, flavonoids, malvidin, peonidin, cyanidin, pelargonidin, and procyanidins. (2) 25 anthocyanins were identified as differential metabolites, including 11 down-regulated and 14 up-regulated; seven anthocyanins with higher abundance in the pink flower. (3) KEGG pathway annotation showed that the differential metabolites were significantly enriched in the anthocyanin biosynthesis pathway; The results of clustering showed that petunidin-3-O-glucoside was the key metabolite of different color P. serrulata cultivars. This study provides important insights into the metabolic mechanism of different flower colors in P. serrulata and a reference for novel color cultivars and variety breeding.
Subjects: Biology >> Botany >> Applied botany submitted time 2021-08-09 Cooperative journals: 《广西植物》
Abstract： In order to investigate the good genes, cultivate the main superior cultivars and discover phylogenetic relationships of Magnolia officinalis, M. officinalis subsp. biloba and M. hypoleuca, we compared the differences among the cp (chloroplast) genomes of three Magnolia species and performed a phylogenetic tree of 14 species. Illumina HiSeq platform was used to sequence and assemble the cp genome of M. hypoleuca. Then the cp genomes of three Magnolia species were annotated by online platform and performed with three Magnolia species cp gene cycles. Moreover, the cp genomes of other 11 Magnolia species were downloaded from the NCBI database and phylogenetic tree of 14 all species cp genomes was constructed based on NJ method. The results indicated that Clean Reads of M. hypoleuca were 19 791 019, and Q30 was 91.33%. The total length of cp genome of M. hypoleuca was 160 051 bp, its GC content was 39.2%, including 37 tRNA and 8 rRNA. Besides, there were respectively six and four more functional gene numbers of M. hypoleuca than the other two Magnolia species, which indicated it had stronger viability. Compared with the cp genome structure of three Magnolia species, it showed that three Magnolia species had similar IR, LSC and SSC structures, GC content and tRNA number, but there were differences in the type and number of coding genes, the number and structure of introns and exons. Besides, the differential functional genes of three Magnolia species were mainly located in LSC region and IR region, involving large ribosomal subunits, small ribosomal subunits and unknown functional genes groups. Furthermore, based on NJ phylogenetic tree, M. hypoleuca was closely related to M. officinalis subsp. biloba, next to M. officinalis. In this study, M. hypoleuca had more abundant cp genome structure, composition and variation characteristics, which was the molecular mechanism of its adaptation to low light and low temperature environment in high latitude area. And it will also provide strong guidance for molecular breeding of excellent Magnolia varieties.
Subjects: Environmental Sciences, Resource Sciences >> Basic Disciplines of Environmental Science and Technology submitted time 2020-04-26 Cooperative journals: 《干旱区研究》
Abstract：以陕西省为研究区，基于景观格局和景观功能2个方面构建景观生态脆弱性模型，分析省域及内部自然单元分区2个层面景观生态脆弱性时空演变，并运用地理探测器方法探究景观生态脆弱性多尺度驱动机制。结果表明：① 2000—2015年陕西省景观格局脆弱性指数分别是0.477 3和0.409 7，降低了6.76%，在空间上高值区分布于北部及中部，低值区分布于中部两侧；景观功能脆弱性指数分别是0.492 6和0.417 4，降低了7.52%，高值区集中于北部和中部，低值区呈零星分布的空间布局。② 研究期间陕西省景观生态脆弱性指数分别为0.427 5和0.369 7，减少了5.78％，呈现出南北方向高低交错的空间布局，且内部分区之间有明显分区过渡表现。其中，黄土高原区脆弱性降低8.55%；关中盆地区脆弱性降低3.81%；秦巴山地区脆弱性降低1.20%。③ 全省及内部分区生态脆弱性的影响因素因地理尺度的差异而不同，自然环境因素对脆弱性变化起重要作用，而社会经济因素呈不断增强态势。本文提出的景观生态脆弱性评价方法可为生态脆弱性评估提供方法参考。
Subjects: Biology >> Zoology submitted time 2018-12-24 Cooperative journals: 《动物营养学报》
Abstract：本试验旨在探究富硒和锗酵母培养物对延边黄牛生长性能、肌肉脂肪酸和氨基酸含量的影响。选取生长发育良好的30月龄的延边黄牛公牛20头，体重为(351±20) kg，随机分为4组，对照组饲喂基础饲粮，试验Ⅰ、Ⅱ和Ⅲ组饲喂在基础饲粮中分别添加0.1%、0.2%和0.3%富硒和锗酵母培养物的试验饲粮，每组5头。试验期90 d。结果表明，与对照组相比：1）试验组的平均日增重均有提高，但变化不显著（P>0.05）；试验Ⅰ、Ⅱ组的饲料转化率分别提高了18.93%（P0.05）。3）试验Ⅲ组肌肉中赖氨酸含量提高了3.81%（P0.05）。综合可知，饲粮中添加富硒和锗酵母培养物可以提高延边黄牛饲料转化率，提高肌肉中亚油酸含量，降低饱和脂肪酸/不饱和脂肪酸，提高肌肉中风味氨基酸（赖氨酸、丙氨酸和谷氨酸）的含量，改善牛肉的风味，建议在延边黄牛饲粮中添加0.2%富硒和锗酵母培养物。
Subjects: Medicine, Pharmacy >> Preclinical Medicine submitted time 2018-06-15 Cooperative journals: 《南方医科大学学报》
Abstract： Objective To investigate whether pigment epithelium-derived factor (PEDF) inhibits invasion and metastasis of breast cancer through regulation of epithelial-mesenchymal transition. Methods The expressions of PEDF, vimentin, and E-cadherin were detected in 119 breast cancer tissues using immunohistochemistry. SK-BR-3 breast cancer cell models of PEDF knockdown and PEDF overexpression were established by transfecting the cells with a PEDF-siRNA vector and a lentivirus-PEDF vector, respectively. Western blotting was used to detect the changes in the expressions of PEDF, vimentin, and E-cadherin in the cells, and the cell invasion and migration ability was assessed using scratch wound healing assay and transwell migration assay. Results PEDF positivity rate was significantly lowered in breast cancer tissues compared with the adjacent tissues. PEDF was positively correlated with the tumor size and the expression level of E-cadherin (r=0.473, P<0.001), but was negatively correlated with vimentin expression (r=-0.412, P<0.001). Transwell invasion experiment showed that PEDF interference enhanced the cell invasion and metastasis, while PEDF overexpression inhibited the invasion and migration of SKBR-3 cells. Western blotting showed that PEDF knockdown significantly decreased the expression of E-cadherin (P<0.05) and increased vimentin expression in the cells (P<0.05). Conclusion PEDF is closely related with the metastasis of breast cancer cells through regulation of epithelial-mesenchymal transition.
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