Based on the household survey of nine villages in Guangdong Province and Hunan Province,we research the relationship between landless farmers and land adjustment,land transfer in the context of rural land contract rig...Based on the household survey of nine villages in Guangdong Province and Hunan Province,we research the relationship between landless farmers and land adjustment,land transfer in the context of rural land contract rights on a long term basis.We demonstrate that the existence of landless farmers does not pose a serious problem for the current rural community.We also explain the reason why the land is no longer readjusted:the expected return of land adjustment is low and the organizational costs are high.展开更多
As a special taxonomy of personality,General Causality Orientations can be usefully characterized in terms of understanding the nature of causation of behavior.Researchers have used General Causality Orientations to e...As a special taxonomy of personality,General Causality Orientations can be usefully characterized in terms of understanding the nature of causation of behavior.Researchers have used General Causality Orientations to explain various organizational phenomena.In this article,we reviewed the literature to understand General Causality Orientations and pointed out the importance of predicting behaviors in the workplace.In accordance with the environmental and personality factors,General Causality Orientations and the Five-Factor Model were distinguished.Furthermore,it was discussed how General Causality Orientations may interpret work behaviors and some implications were given for organizations.展开更多
A revolution in medical diagnosis and treatment is being driven by the use of artificial intelligence(AI)in medical imaging.The diagnostic efficacy and accuracy of medical imaging are greatly enhanced by AI technologi...A revolution in medical diagnosis and treatment is being driven by the use of artificial intelligence(AI)in medical imaging.The diagnostic efficacy and accuracy of medical imaging are greatly enhanced by AI technologies,especially deep learning,that performs image recognition,feature extraction,and pattern analysis.Furthermore,AI has demonstrated significant promise in assessing the effects of treatments and forecasting the course of diseases.It also provides doctors with more advanced tools for managing the conditions of their patients.AI is poised to play a more significant role in medical imaging,especially in real-time image processing and multimodal fusion.By integrating multiple forms of image data,multimodal fusion technology provides more comprehensive disease information,whereas real-time image analysis can assist surgeons in making more precise de-cisions.By tailoring treatment regimens to each patient's unique needs,AI enhances both the effectiveness of treatment and the patient experience.Overall,AI in medical imaging promises a bright future,significantly enhancing diagnostic precision and therapeutic efficacy,and ultimately delivering higher-quality medical care to patients.展开更多
Hexavalent chromium Cr(Ⅵ),as a well-established carcinogen,contributes to tumorigenesis for many human cancers,especially respiratory and digestive tumors.However,the potential function and relevant mechanism of Cr(...Hexavalent chromium Cr(Ⅵ),as a well-established carcinogen,contributes to tumorigenesis for many human cancers,especially respiratory and digestive tumors.However,the potential function and relevant mechanism of Cr(Ⅵ)on the initiation of esophageal carcinogenesis are largely unknown.Here,immortalized human esophageal epithelial cells(HEECs)were induced to be malignantly transformed cells,termed HEEC-Cr(Ⅵ)cells,via chronic exposure to Cr(Ⅵ),which simulates the progress of esophageal tumorigenesis.In vitro and in vivo experiments demonstrated that HEEC-Cr(Ⅵ)cells obtain the ability of anchorage-independent growth,greater proliferative capacity,cancer stem cell properties,and the capacity to form subcutaneous xenografts in BALB/c nude mice when compared to their parental cells,HEECs.Additionally,HEEC-Cr(Ⅵ)cells exhibited weakened cell motility and enhanced cell adhesion.Interestingly,HEECs with acute exposure to Cr(Ⅵ)failed to display those malignant phenotypes of HEEC-Cr(Ⅵ)cells,suggesting that Cr(Ⅵ)-induced malignant transformation,but not Cr(Ⅵ)itself,is the cause for the tumor characteristics of HEEC-Cr(Ⅵ)cells.Mechanistically,chronic exposure to Cr(Ⅵ)induced abnormal activation of Notch signaling,which is crucial to maintaining the capacity for malignant proliferation and stemness of HEEC-Cr(Ⅵ)cells.As expected,N-[N-(3,5-difluorophenacetyl)-L-alanyl]-S-phenylglycine t-butyl ester(DAPT),an inhibitor for the Notch pathway,drastically attenuated cancerous phenotypes of HEEC-Cr(Ⅵ)cells.In conclusion,our study clarified the molecular mechanism underlying Cr(Ⅵ)-induced esophageal tumorigenesis,which provides novel insights for further basic research and clinical therapeutic strategies about Cr(Ⅵ)-associated esophageal cancer.展开更多
Sensory inputs stimulated by Zusanli（ST36） acupuncture in the abdomen are known to converge in the upper cervical cord. However, it is unclear whether these inputs are subsequently conveyed to the hypothalamic parav...Sensory inputs stimulated by Zusanli（ST36） acupuncture in the abdomen are known to converge in the upper cervical cord. However, it is unclear whether these inputs are subsequently conveyed to the hypothalamic paraventricular nucleus and what kind of afferent fibers are involved. We focused on the upper cervical cord, where afferent inputs converge, and detected c-fos expression in oxytocinergic neurons. We found that Zusanli acupuncture therapy effectively elevated intragastric pressure, but inhibited expression of c-fos in oxytocinergic neurons of the paraventricular nucleus in upper cervical cord injured rats. These Zusanli acupuncture effects remained even after complete dorsal cord transection. However, after complete transection of the spinal cord or dorsolateral funiculus, the effects were significantly attenuated and even disappeared. These findings suggest that the paraventricular nucleus is responsible for pooling and integrating signals from the Zusanli acupuncture and sensory information from the intragastric pressure variation, thereby contributing to the regulation of intragastric pressure. The upper cervical cord serves as the key link between ascending and descending pathways, which conveys afferent inputs to the paraventricular nucleus through the dorsolateral funiculus.展开更多
ZrB2 -SiC composite ceramic has been successfully introduced as heating element in super high temperature .field. This paper further investigated the microstructure of ZrB2 - SiC composite ceramic heating element an...ZrB2 -SiC composite ceramic has been successfully introduced as heating element in super high temperature .field. This paper further investigated the microstructure of ZrB2 - SiC composite ceramic heating element and the relationship between electric properties and temperature. SEM photos show that the heating element consists of SiC grains and ZrBz grains smaller than 10 μm. The voltage and current gradually increase and the furnace tempera- ture rises lineally with heating time prolonging. The electric resistance increases linearly with the temperature rising. The service temperatltre of the heating element can reach 1 800 ℃ and 2 150 ℃ in air and argon at- mosphere, respectively.展开更多
Species of the genus Dichopygina Vilkamaa, Hippa ＆ Komarova, 2004 has been morphologically cryptic. In this paper, eight species of the genus were clearly defined by DNA barcodes. Based on both molecular and morpholo...Species of the genus Dichopygina Vilkamaa, Hippa ＆ Komarova, 2004 has been morphologically cryptic. In this paper, eight species of the genus were clearly defined by DNA barcodes. Based on both molecular and morphological evidences, D. bernhardi Vilkamaa, Hippa ＆ Komarova, 2004, stat. rev. is separated from D. perfecta（Pettey, 1918）; a closely allied new species, D. tibetana Leng, Heller ＆ Huang, sp. nov., is described from Tibet, China. Detailed descriptions and figures of the two species are presented.展开更多
Guvermectin,a purine nucleoside natural product produced by the genus Streptomyces,has recently been registered as a new biopesticide to boost rice yield.Despite its economic and agricultural significance,the regulato...Guvermectin,a purine nucleoside natural product produced by the genus Streptomyces,has recently been registered as a new biopesticide to boost rice yield.Despite its economic and agricultural significance,the regulatory mechanisms of guvermectin biosynthesis remain essentially unknown,hindering industrial produc-tion and widespread agricultural application.Here,we examined the roles of two LacI family regulators,gvmR and gvmR2,located within and adjacent to the guvermectin biosynthesis cluster,respectively,in guvermectin production in Streptomyces caniferus NEAU6.GvmR activated the expression of the guvermectin cluster by binding to the promoters of gvmR,gvmA,and O1,while GvmR2 repressed the guvermectin cluster via competitive binding to promoters containing GvmR-binding sites,specifically,a 14-bp palindromic sequences:5′-RTCATWCGYATGAY-3′(R=G/A,W=A/T,Y=T/C).Moreover,GvmR indirectly activates the expression of gvmR2 while GvmR2 feedback inhibits gvmR transcription,suggesting a functional interaction between the two regulators for coordinating guvermectin production.Overexpression of gvmR via the T7 RNA polymerase-T7 promoter system in the gvmR2 mutant significantly elevated guvermectin production by 125%(from 631 mg L^(1) to 1422 mg L^(1)),compared to the parental strain NEAU6.This suggested that combinatorial manipulation of gvmR and gvmR2 is useful for improving guvermectin production.These findings enrich our knowledge of the regulatory network for guvermectin biosynthesis,and offer key targets and effective strategies for high-titer guvermectin production.展开更多
Streptomyces can produce numerous antibiotics and many other bioactive compounds.Recently,the molecular mechanisms of transcriptional regulators in control of antibiotic production by influencing the expression of bio...Streptomyces can produce numerous antibiotics and many other bioactive compounds.Recently,the molecular mechanisms of transcriptional regulators in control of antibiotic production by influencing the expression of biosynthetic gene clusters(BGCs)have been extensively studied.However,for regulators that affect both antibiotic production and cell growth,the way to influence antibiotic production may be diverse,but related studies are limited.Here,based on time-course transcriptome analysis,a four-component system,SbrH1-R,consisting of the two-component system SbrKR(SBI_03479/3478)and two hypothetical proteins SbrH1(SBI_03481)and SbrH2(SBI_03480)potentially related with the biosynthesis of milbemycins was identified in Streptomyces bingchenggensis BC-101-4.Deletion of sbrH1-R resulted in weakened cell growth but a 110%increase of milbemycin production compared with that in BC-101-4.Comparative transcriptome analyses of the sbrH1-R mutant and BC-101-4 revealed that SbrH1-R not only indirectly represses milbemycin BGC expression,but also inhibits milbemycin production by modulating expression levels of genes related to precursor supply and antibiotic efflux.Further genetic experiments identified several new targets,including five precursor supply-associated reactions/pathways(e.g.,the reaction from pyruvate to acetyl-CoA,the reaction from acetyl-CoA to citrate,the fatty acidβ-oxidation process,and the branched chain amino acid and phenylalanine acid degradation pathways)and a milbemycin exporter system(MilEX2)that can be engineered for milbemycin overproduction.These results shed new light on the understanding of regulation of milbemycin biosynthesis and provide useful targets for future metabolic engineering of the native host to improve milbemycin production.展开更多
基金Supported by National Social Science Fund Project(11BJY094)211 Project of College of Economics and Management,South China Agricultural University(2011211TD02)
文摘Based on the household survey of nine villages in Guangdong Province and Hunan Province,we research the relationship between landless farmers and land adjustment,land transfer in the context of rural land contract rights on a long term basis.We demonstrate that the existence of landless farmers does not pose a serious problem for the current rural community.We also explain the reason why the land is no longer readjusted:the expected return of land adjustment is low and the organizational costs are high.
基金ACKNOWLEDGEMENTS We especially thank the National Science Foundation of China(70771009,71071017)the Fundamental Research Funds for the Central Universities(FRF-BR-09-019)for supporting this research.
文摘As a special taxonomy of personality,General Causality Orientations can be usefully characterized in terms of understanding the nature of causation of behavior.Researchers have used General Causality Orientations to explain various organizational phenomena.In this article,we reviewed the literature to understand General Causality Orientations and pointed out the importance of predicting behaviors in the workplace.In accordance with the environmental and personality factors,General Causality Orientations and the Five-Factor Model were distinguished.Furthermore,it was discussed how General Causality Orientations may interpret work behaviors and some implications were given for organizations.
基金supported by the National Natural Science Foundation of China(Grant Nos.82360266,81960224,and 81860248)Guizhou Provincial Basic Research Program(Grant Nos.Qiankehe basic-ZK[2023]general 395+2 种基金Qiankehe basic-ZK[2023]general 324Qiankehe basic-MS[2025]548)Key Lab of Acute Brain Injury and Function Repair at Guizhou Medical University(Grant No.[2024]fy0071).
文摘A revolution in medical diagnosis and treatment is being driven by the use of artificial intelligence(AI)in medical imaging.The diagnostic efficacy and accuracy of medical imaging are greatly enhanced by AI technologies,especially deep learning,that performs image recognition,feature extraction,and pattern analysis.Furthermore,AI has demonstrated significant promise in assessing the effects of treatments and forecasting the course of diseases.It also provides doctors with more advanced tools for managing the conditions of their patients.AI is poised to play a more significant role in medical imaging,especially in real-time image processing and multimodal fusion.By integrating multiple forms of image data,multimodal fusion technology provides more comprehensive disease information,whereas real-time image analysis can assist surgeons in making more precise de-cisions.By tailoring treatment regimens to each patient's unique needs,AI enhances both the effectiveness of treatment and the patient experience.Overall,AI in medical imaging promises a bright future,significantly enhancing diagnostic precision and therapeutic efficacy,and ultimately delivering higher-quality medical care to patients.
基金supported by the Special Construction Project Fund for Taishan Mountain Scholars of Shandong Provincethe Jinan Medicine Research Program+1 种基金the Nurturing and Development Fund from The Second Hospital of Shandong University(No.2022YP62)the Shandong Provincial Natural Science Foundation for Young Scholars(No.ZR2022QH285),China.
文摘Hexavalent chromium Cr(Ⅵ),as a well-established carcinogen,contributes to tumorigenesis for many human cancers,especially respiratory and digestive tumors.However,the potential function and relevant mechanism of Cr(Ⅵ)on the initiation of esophageal carcinogenesis are largely unknown.Here,immortalized human esophageal epithelial cells(HEECs)were induced to be malignantly transformed cells,termed HEEC-Cr(Ⅵ)cells,via chronic exposure to Cr(Ⅵ),which simulates the progress of esophageal tumorigenesis.In vitro and in vivo experiments demonstrated that HEEC-Cr(Ⅵ)cells obtain the ability of anchorage-independent growth,greater proliferative capacity,cancer stem cell properties,and the capacity to form subcutaneous xenografts in BALB/c nude mice when compared to their parental cells,HEECs.Additionally,HEEC-Cr(Ⅵ)cells exhibited weakened cell motility and enhanced cell adhesion.Interestingly,HEECs with acute exposure to Cr(Ⅵ)failed to display those malignant phenotypes of HEEC-Cr(Ⅵ)cells,suggesting that Cr(Ⅵ)-induced malignant transformation,but not Cr(Ⅵ)itself,is the cause for the tumor characteristics of HEEC-Cr(Ⅵ)cells.Mechanistically,chronic exposure to Cr(Ⅵ)induced abnormal activation of Notch signaling,which is crucial to maintaining the capacity for malignant proliferation and stemness of HEEC-Cr(Ⅵ)cells.As expected,N-[N-(3,5-difluorophenacetyl)-L-alanyl]-S-phenylglycine t-butyl ester(DAPT),an inhibitor for the Notch pathway,drastically attenuated cancerous phenotypes of HEEC-Cr(Ⅵ)cells.In conclusion,our study clarified the molecular mechanism underlying Cr(Ⅵ)-induced esophageal tumorigenesis,which provides novel insights for further basic research and clinical therapeutic strategies about Cr(Ⅵ)-associated esophageal cancer.
基金supported by the National Natural Science Foundation of China,No.81273677a grant from the Postgraduate Innovation Topics of Hunan University of Chinese Medicine in China in 2014,No.2014CX01
文摘Sensory inputs stimulated by Zusanli（ST36） acupuncture in the abdomen are known to converge in the upper cervical cord. However, it is unclear whether these inputs are subsequently conveyed to the hypothalamic paraventricular nucleus and what kind of afferent fibers are involved. We focused on the upper cervical cord, where afferent inputs converge, and detected c-fos expression in oxytocinergic neurons. We found that Zusanli acupuncture therapy effectively elevated intragastric pressure, but inhibited expression of c-fos in oxytocinergic neurons of the paraventricular nucleus in upper cervical cord injured rats. These Zusanli acupuncture effects remained even after complete dorsal cord transection. However, after complete transection of the spinal cord or dorsolateral funiculus, the effects were significantly attenuated and even disappeared. These findings suggest that the paraventricular nucleus is responsible for pooling and integrating signals from the Zusanli acupuncture and sensory information from the intragastric pressure variation, thereby contributing to the regulation of intragastric pressure. The upper cervical cord serves as the key link between ascending and descending pathways, which conveys afferent inputs to the paraventricular nucleus through the dorsolateral funiculus.
文摘ZrB2 -SiC composite ceramic has been successfully introduced as heating element in super high temperature .field. This paper further investigated the microstructure of ZrB2 - SiC composite ceramic heating element and the relationship between electric properties and temperature. SEM photos show that the heating element consists of SiC grains and ZrBz grains smaller than 10 μm. The voltage and current gradually increase and the furnace tempera- ture rises lineally with heating time prolonging. The electric resistance increases linearly with the temperature rising. The service temperatltre of the heating element can reach 1 800 ℃ and 2 150 ℃ in air and argon at- mosphere, respectively.
基金financially supported by the National Natural Science Foundation of China(31372244)the Science and Technology Department of Zhejiang Province(2013C32082)Norwegian Taxonomy Initiative(NTI)(Artsprosjektet,70184228)
文摘Species of the genus Dichopygina Vilkamaa, Hippa ＆ Komarova, 2004 has been morphologically cryptic. In this paper, eight species of the genus were clearly defined by DNA barcodes. Based on both molecular and morphological evidences, D. bernhardi Vilkamaa, Hippa ＆ Komarova, 2004, stat. rev. is separated from D. perfecta（Pettey, 1918）; a closely allied new species, D. tibetana Leng, Heller ＆ Huang, sp. nov., is described from Tibet, China. Detailed descriptions and figures of the two species are presented.
基金supported by the National Key Research and Development Program of China(2022YFD1700205)the Agricultural Sciences and Technology Innovation Program(CAAS-CSCB-202401)。
文摘Guvermectin,a purine nucleoside natural product produced by the genus Streptomyces,has recently been registered as a new biopesticide to boost rice yield.Despite its economic and agricultural significance,the regulatory mechanisms of guvermectin biosynthesis remain essentially unknown,hindering industrial produc-tion and widespread agricultural application.Here,we examined the roles of two LacI family regulators,gvmR and gvmR2,located within and adjacent to the guvermectin biosynthesis cluster,respectively,in guvermectin production in Streptomyces caniferus NEAU6.GvmR activated the expression of the guvermectin cluster by binding to the promoters of gvmR,gvmA,and O1,while GvmR2 repressed the guvermectin cluster via competitive binding to promoters containing GvmR-binding sites,specifically,a 14-bp palindromic sequences:5′-RTCATWCGYATGAY-3′(R=G/A,W=A/T,Y=T/C).Moreover,GvmR indirectly activates the expression of gvmR2 while GvmR2 feedback inhibits gvmR transcription,suggesting a functional interaction between the two regulators for coordinating guvermectin production.Overexpression of gvmR via the T7 RNA polymerase-T7 promoter system in the gvmR2 mutant significantly elevated guvermectin production by 125%(from 631 mg L^(1) to 1422 mg L^(1)),compared to the parental strain NEAU6.This suggested that combinatorial manipulation of gvmR and gvmR2 is useful for improving guvermectin production.These findings enrich our knowledge of the regulatory network for guvermectin biosynthesis,and offer key targets and effective strategies for high-titer guvermectin production.
基金This work was financially supported by National Natural Science Foundation of China(31872936,31972291,and 31972348).
文摘Streptomyces can produce numerous antibiotics and many other bioactive compounds.Recently,the molecular mechanisms of transcriptional regulators in control of antibiotic production by influencing the expression of biosynthetic gene clusters(BGCs)have been extensively studied.However,for regulators that affect both antibiotic production and cell growth,the way to influence antibiotic production may be diverse,but related studies are limited.Here,based on time-course transcriptome analysis,a four-component system,SbrH1-R,consisting of the two-component system SbrKR(SBI_03479/3478)and two hypothetical proteins SbrH1(SBI_03481)and SbrH2(SBI_03480)potentially related with the biosynthesis of milbemycins was identified in Streptomyces bingchenggensis BC-101-4.Deletion of sbrH1-R resulted in weakened cell growth but a 110%increase of milbemycin production compared with that in BC-101-4.Comparative transcriptome analyses of the sbrH1-R mutant and BC-101-4 revealed that SbrH1-R not only indirectly represses milbemycin BGC expression,but also inhibits milbemycin production by modulating expression levels of genes related to precursor supply and antibiotic efflux.Further genetic experiments identified several new targets,including five precursor supply-associated reactions/pathways(e.g.,the reaction from pyruvate to acetyl-CoA,the reaction from acetyl-CoA to citrate,the fatty acidβ-oxidation process,and the branched chain amino acid and phenylalanine acid degradation pathways)and a milbemycin exporter system(MilEX2)that can be engineered for milbemycin overproduction.These results shed new light on the understanding of regulation of milbemycin biosynthesis and provide useful targets for future metabolic engineering of the native host to improve milbemycin production.
