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排序方式: 共有682条查询结果,搜索用时 31 毫秒
101.
Jurre Y. Siegers Vijaykrishna Dhanasekaran Ruopeng Xie Yi-Mo Deng Sarika Patel Vanra Ieng Jean Moselen Heidi Peck Ammar Aziz Borann Sarr Savuth Chin Seng Heng Asheena Khalakdina Michael Kinzer Darapheak Chau Philomena Raftery Veasna Duong Ly Sovann Ian G. Barr Erik A. Karlsson 《Journal of virology》2021,95(24)
102.
By their own devices: invasive Argentine ants have shifted diet without clear aid from symbiotic microbes
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Yi Hu David A. Holway Piotr Łukasik Linh Chau Adam D. Kay Edward G. LeBrun Katie A. Miller Jon G. Sanders Andrew V. Suarez Jacob A. Russell 《Molecular ecology》2017,26(6):1608-1630
The functions and compositions of symbiotic bacterial communities often correlate with host ecology. Yet cause–effect relationships and the order of symbiont vs. host change remain unclear in the face of ancient symbioses and conserved host ecology. Several groups of ants exemplify this challenge, as their low‐nitrogen diets and specialized symbioses appear conserved and ancient. To address whether nitrogen‐provisioning symbionts might be important in the early stages of ant trophic shifts, we studied bacteria from the Argentine ant, Linepithema humile – an invasive species that has transitioned towards greater consumption of sugar‐rich, nitrogen‐poor foods in parts of its introduced range. Bacteria were present at low densities in most L. humile workers, and among those yielding quality 16S rRNA amplicon sequencing data, we found just three symbionts to be common and dominant. Two, a Lactobacillus and an Acetobacteraceae species, were shared between native and introduced populations. The other, a Rickettsia, was found only in two introduced supercolonies. Across an eight‐year period of trophic reduction in one introduced population, we found no change in symbionts, arguing against a relationship between natural dietary change and microbiome composition. Overall, our findings thus argue against major changes in symbiotic bacteria in association with the invasion and trophic shift of L. humile. In addition, genome content from close relatives of the identified symbionts suggests that just one can synthesize most essential amino acids; this bacterium was only modestly abundant in introduced populations, providing little support for a major role of nitrogen‐provisioning symbioses in Argentine ant's dietary shift. 相似文献
103.
Nguyen Hoang Loc Vo Chau Tuan Doan Huu Nhat Binh Truong Thi Bich Phuong Tae-Geum Kim Moon-Sik Yang 《Biotechnology and Bioprocess Engineering》2009,14(5):619-624
We developed a cell suspension culture system for zedoary (Curcuma zedoaria Roscoe), using 100 g fresh weight inoculum in a batch culture. The maximum cell biomass of 68.46 g/L fresh weight was obtained
after 14 days of culture in a 10 L bioreactor with a pitch-blade impeller maintained at an agitation speed of 150 rpm and
an aeration rate of 2.5 L/min. The accumulation of sesquiterpenes and polysaccharide in zedoary cells from 2 to 18 days was
measured by HPLC and a phenol-sulfuric acid assay, respectively. The total polysaccharide concentration increased between
2 to 10 days of culture and reached a maximum value of 6.55%. HPLC revealed several eluted peaks of sesquiterpenes, which
increased in amplitude from days 2 to 10. Furthermore, our results indicated that biotransformation occurred in the cell suspension,
transforming certain sesquiterpenes into other types during culture. 相似文献
104.
105.
Constance Schultsz Nguyen Van Dung Le Thanh Hai Do Quang Ha J. S. Malik Peiris Wilina Lim Jean-Michel Garcia Nguyen Dac Tho Nguyen Thi Hoang Lan Huynh Huu Tho Phan Xuan Thao H. Rogier van Doorn Nguyen Van Vinh Chau Jeremy Farrar Menno D. de Jong 《PloS one》2009,4(11)
Background
Between 2003 and 2005, highly pathogenic avian influenza A (H5N1) viruses caused large scale outbreaks in poultry in the Ho Chi Minh City area in Vietnam. We studied the prevalence of antibodies against H5N1 in poultry workers and cullers who were active in the program in Ho Chi Minh City in 2004 and 2005.Methodology/Principal Findings
Single sera from 500 poultry workers and poultry cullers exposed to infected birds were tested for antibodies to avian influenza H5N1, using microneutralization assays and hemagglutination inhibition assay with horse blood. All sera tested negative using microneutralization tests. Three samples showed a 1∶80 titer in the hemagglutination inhibition assay.Conclusions/Significance
This study provides additional support for the low transmissibility of clade 1 H5N1 to humans, but limited transmission to highly exposed persons cannot be excluded given the presence of low antibody titers in some individuals. 相似文献106.
Vos TJ Balani S Blackburn C Chau RW Danca MD Drabic SV Farrer CA Patane MA Stroud SG Yowe DL Claiborne CF 《Bioorganic & medicinal chemistry letters》2006,16(8):2302-2305
The identification and optimization of a series of acylguanidine-based melanocortin-4 receptor antagonists is discussed. 相似文献
107.
108.
Samuel García-Nieto Ramneek K. Johal Kevin M. Shakesheff Mohamed Emara Pierre-Joseph Royer David Y. S. Chau Farouk Shakib Amir M. Ghaemmaghami 《PloS one》2010,5(4)
Background
Sampling the microenvironment at sites of microbial exposure by dendritic cells (DC) and their subsequent interaction with T cells in the paracortical area of lymph nodes are key events for initiating immune responses. Most of our knowledge of such events in human is based on in vitro studies performed in the absence of extracellular matrix (ECM) proteins. ECM in basement membranes and interstitial spaces of different tissues, including lymphoid organs, plays an important role in controlling specific cellular functions such as migration, intracellular signalling and differentiation. The aim of this study was, therefore, to investigate the impact of two abundant ECM components, fibronectin and laminin, on the phenotypical and functional properties of DC and how that might influence DC induced T-cell differentiation.Methodology/Principal Findings
Human monocyte derived DC were treated with laminin and fibronectin for up to 48 hours and their morphology and phenotype was analyzed using scanning electron microscopy, flow cytometry and real time PCR. The endocytic ability of DC was determined using flow cytometry. Furthermore, co-culture of DC and T cells were established and T cell proliferation and cytokine profile was measured using H3-thymidine incorporation and ELISA respectively. Finally, we assessed formation of DC-T cell conjugates using different cell trackers and flow cytometry. Our data show that in the presence of ECM, DC maintain a ‘more immature’ phenotype and express higher levels of key endocytic receptors, and as a result become significantly better endocytic cells, but still fully able to mature in response to stimulation as evidenced by their superior ability to induce antigen-specific T cell differentiation.Conclusion
These studies underline the importance of including ECM components in in vitro studies investigating DC biology and DC-T cell interaction. Within the context of antigen specific DC induced T cell proliferation, inclusion of ECM proteins could lead to development of more sensitive assays. 相似文献109.
110.
Tran Tinh Hien Nguyen Thi Dung Nguyen Thanh Truong Ninh Thi Thanh Van Tran Nguyen Bich Chau Nguyen Van Minh Hoang Tran Thi Thu Nga Cao Thu Thuy Pham Van Minh Nguyen Thi Cam Binh Tran Thi Diem Ha Pham Van Toi To Song Diep James I. Campbell Elaine Stockwell Constance Schultsz Cameron P. Simmons Clare Glover Winnie Lam Filipe Marques James P. May Anthony Upton Ronald Budhram Gordon Dougan Jeremy Farrar Nguyen Van Vinh Chau Christiane Dolecek 《PloS one》2010,5(7)