586 research outputs found
Dynamic Generation and Editing System for Wrongly Written Chinese Characters Font
The uniqueness of Chinese makes Chinese language a hotspot in language learning. In view of the problem of wrongly written character teaching in Chinese language teaching, it provides a simple, convenient, and efficient input method of wrongly written characters and realizes a dynamic generation and editing system for wrongly written Chinese character font, which solves the problems of real-time edit, coding, and input of wrongly written character in editing process using dynamic editing technology, and provides a convenient input method of wrongly written character in editing, printing, typesetting, and the research of digital Chinese language teaching. This method can also be used in dynamic editing, generation and processing of ancient variants, Oracle bone inscriptions, Bronze inscription, folk combined characters, and other fonts
Calculation of Sentence Semantic Similarity Based on Syntactic Structure
Combined with the problem of single direction of the solution of the existing sentence similarity algorithms, an algorithm for sentence semantic similarity based on syntactic structure was proposed. Firstly, analyze the sentence constituent, then through analysis convert sentence similarity into words similarity on the basis of syntactic structure, then convert words similarity into concept similarity through words disambiguation, and, finally, realize the semantic similarity comparison. It also gives the comparison rules in more detail for the modifier words in the sentence which also have certain contributions to the sentence. Under the same test condition, the experiments show that the proposed algorithm is more intuitive understanding of people and has higher accuracy
LIVE, ATTENUATED VACCINES AND METHODS OF MAKING AND USING
A live, attenuated HIV vaccine is provided, and methods of making a atenuated HIV vaccine are provided
A Novel Route for Preparation of Hollow Carbon Nanospheres Without Introducing Template
A newly developed route for the synthesis of hollow carbon nanospheres without introducing template under hydrothermal conditions was reported. Hollow carbon nanospheres with the diameter of about 100 nm were synthesized using alginate as reagent only. Many instruments were applied to characterize the morphologies and structures of carbon hollow nanospheres, such as XRD, TEM, and Raman spectroscopy. The possible formation and growth mechanism of carbon hollow spheres were discussed on the basis of the investigation of reaction influence factors, such as temperature, time, and content. The findings would be useful for the synthesis of more materials with hollow structure and for the potential use in many aspects. The loading of SnO2on the surface of carbon hollow spheres was processed, and its PL property was also characterized
A Coaxially Integrated Photonic Orbital Angular Momentum Beam Multiplexer
We demonstrate an integrated photonic orbital angular momentum beam multiplexer consisting of four nested arc waveguide gratings. Well-defined OAM mode emissions over wide bandwidth of 1-nm enables simultaneous wavelength division multiplexing and OAM multiplexing
Altered Ratio of T Follicular Helper Cells to T Follicular Regulatory Cells Correlates with Autoreactive Antibody Response in Simian Immunodeficiency Virus–Infected Rhesus Macaques
Individuals with chronic HIV-1 infection have an increased prevalence of autoreactive Abs. Many of the isolated HIV broadly neutralizing Abs from these individuals are also autoreactive. However, the underlying mechanism(s) that produce these autoreactive broadly neutralizing Abs remains largely unknown. The highly regulated coordination among B cells, T follicular helper (TFH) cells, and T follicular regulatory (TFR) cells in germinal centers (GCs) of peripheral lymphatic tissues (LTs) is essential for defense against pathogens while also restricting autoreactive responses. We hypothesized that an altered ratio of TFH/TFR cells in the GC contributes to the increased prevalence of autoreactive Abs in chronic HIV infection. We tested this hypothesis using a rhesus macaque (RM) SIV model. We measured the frequency of TFH cells, TFR cells, and GC B cells in LTs and anti-dsDNA and anti-phospholipid Abs from Indian RMs, with and without SIV infection. We found that the frequency of anti-dsDNA and antiphospholipid Abs was much higher in chronically infected RMs (83.3% [5/6] and 66.7% [4/6]) than in acutely infected RMs (33.3% [2/6] and 18.6% [1/6]) and uninfected RMs (0% [0/6] and 18.6% [1/6]). The increased ratio of TFH/TFR cells in SIV infection correlated with anti-dsDNA and anti-phospholipid autoreactive Ab levels, whereas the frequency of TFR cells alone did not correlate with the levels of autoreactive Abs. Our results provide direct evidence that the ratio of TFH/TFR cells in LTs is critical for regulating autoreactive Ab production in chronic SIV infection and possibly, by extension, in chronic HIV-1 infection
High-fat diet feeding exacerbates HIV-1 rectal transmission
High-fat diet (HFD) is well known to impact various aspects of gut health and has been associated with many diseases and inflammation. However, the impact of HFD feeding on HIV-1 rectal transmission has not yet been well addressed. With an increasing threat of HIV-1 infection in men who have sex with men (MSM), where the rectal route is the primary mode of infection, it is imperative to understand the impact of HFD on gut microbiota and inflammation and consequently, its effect on HIV-1 rectal transmission. Here, we utilized our double humanized bone marrow, liver, thymus (dHu-BLT) mouse model to assess the impact of HFD feeding on the host’s susceptibility to HIV-1 rectal transmission. We found that feeding an HFD successfully altered the gut microbial composition within 3 weeks in the dHu-BLT mouse model. In addition, levels of inflammatory mediators, specifically IL-12p70, IP-10, ICAM-1, and fecal calprotectin, were significantly higher in HFD-fed mice compared to control mice on a regular chow diet. We also observed that significantly different inflammatory markers (IL-12p70 and ICAM-1) were negatively correlated with the number of observed ASVs, Shannon diversity, and Faith’s diversity in the HFD-fed group. Notably, when repeatedly challenged with a low dose of HIV-1 via a rectal route, mice receiving an HFD were significantly more susceptible to HIV-1 rectal infection than control mice. Together, these results underscore the impact of HFD feeding on the gut microbiota and inflammation and suggest the significance of diet-induced gut microbial dysbiosis and inflammation in promoting viral infection
SIVcpz closely related to the ancestral HIV-1 is less or non-pathogenic to humans in a hu-BLT mouse model
The HIV-1 pandemic is a consequence of the cross-species transmission of simian immunodeficiency virus in wild chimpanzees (SIVcpz) to humans. Our previous study demonstrated SIVcpz strains that are closely related to the ancestral viruses of HIV-1 groups M (SIVcpzMB897) and N (SIVcpzEK505) and two SIVcpz lineages that are not associated with any known HIV-1 infections in humans (SIVcpzMT145 and SIVcpzBF1167), all can readily infect and robustly replicate in the humanized-BLT mouse model of humans. However, the comparative pathogenicity of different SIVcpz strains remains unknown. Herein, we compared the pathogenicity of the above four SIVcpz strains with HIV-1 using humanized-BLT mice. Unexpectedly, we found that all four SIVcpz strains were significantly less pathogenic or non-pathogenic compared to HIV-1, manifesting lower degrees of CD4+ T-cell depletion and immune activation. Transcriptome analyses of CD4+ T cells from hu-BLT mice infected with SIVcpz versus HIV-1 revealed enhanced expression of genes related to cell survival and reduced inflammation/immune activation in SIVcpz-infected mice. Together, our study results demonstrate for the first time that SIVcpz is significantly less or non-pathogenic to human immune cells compared to HIV-1. Our findings lay the groundwork for a possible new understanding of the evolutionary origins of HIV-1, where the initial SIVcpz crossspecies transmission virus may be initially less pathogenic to humans
SIVcpz closely related to the ancestral HIV-1 is less or non-pathogenic to humans in a hu-BLT mouse model
The HIV-1 pandemic is a consequence of the cross-species transmission of simian immunodeficiency virus in wild chimpanzees (SIVcpz) to humans. Our previous study demonstrated SIVcpz strains that are closely related to the ancestral viruses of HIV-1 groups M (SIVcpzMB897) and N (SIVcpzEK505) and two SIVcpz lineages that are not associated with any known HIV-1 infections in humans (SIVcpzMT145 and SIVcpzBF1167), all can readily infect and robustly replicate in the humanized-BLT mouse model of humans. However, the comparative pathogenicity of different SIVcpz strains remains unknown. Herein, we compared the pathogenicity of the above four SIVcpz strains with HIV-1 using humanized-BLT mice. Unexpectedly, we found that all four SIVcpz strains were significantly less pathogenic or non-pathogenic compared to HIV-1, manifesting lower degrees of CD4+ T-cell depletion and immune activation. Transcriptome analyses of CD4+ T cells from hu-BLT mice infected with SIVcpz versus HIV-1 revealed enhanced expression of genes related to cell survival and reduced inflammation/immune activation in SIVcpz-infected mice. Together, our study results demonstrate for the first time that SIVcpz is significantly less or non-pathogenic to human immune cells compared to HIV-1. Our findings lay the groundwork for a possible new understanding of the evolutionary origins of HIV-1, where the initial SIVcpz crossspecies transmission virus may be initially less pathogenic to humans
A strategy of gene overexpression based on tandem repetitive promoters in Escherichia coli
<p>Abstract</p> <p>Background</p> <p>For metabolic engineering, many rate-limiting steps may exist in the pathways of accumulating the target metabolites. Increasing copy number of the desired genes in these pathways is a general method to solve the problem, for example, the employment of the multi-copy plasmid-based expression system. However, this method may bring genetic instability, structural instability and metabolic burden to the host, while integrating of the desired gene into the chromosome may cause inadequate transcription or expression. In this study, we developed a strategy for obtaining gene overexpression by engineering promoter clusters consisted of multiple core-<it>tac-</it>promoters (MCP<it>tac</it>s) in tandem.</p> <p>Results</p> <p>Through a uniquely designed <it>in vitro </it>assembling process, a series of promoter clusters were constructed. The transcription strength of these promoter clusters showed a stepwise enhancement with the increase of tandem repeats number until it reached the critical value of five. Application of the MCP<it>tac</it>s promoter clusters in polyhydroxybutyrate (PHB) production proved that it was efficient. Integration of the <it>phaCAB </it>genes with the 5CP<it>tac</it>s promoter cluster resulted in an engineered <it>E.coli </it>that can accumulate 23.7% PHB of the cell dry weight in batch cultivation.</p> <p>Conclusions</p> <p>The transcription strength of the MCP<it>tac</it>s promoter cluster can be greatly improved by increasing the tandem repeats number of the core-<it>tac</it>-promoter. By integrating the desired gene together with the MCP<it>tac</it>s promoter cluster into the chromosome of <it>E. coli</it>, we can achieve high and stale overexpression with only a small size. This strategy has an application potential in many fields and can be extended to other bacteria.</p
- …