34 research outputs found
Construction and Characterization of a Chimeric Virus (BIV/HIV-1) Carrying the Bovine Immunodeficiency Virus \u3ci\u3egag\u3c/i\u3e-\u3ci\u3epol\u3c/i\u3e Gene: Research Letters
HIV-1HXB2 5âČLTR region, most of BIVR29 gag-pol segment and HIV-1HXB2 pol IN-3âČLTR region were respectively amplified. A chimeric clone, designated as pHBIV3753, was constructed by cloning three fragments sequentially into pUC18. MT4 cells were transfected with pHBIV3753. The replication and expressions of the chimeric virus (HBIV3753) were monitored by RT activity and IFA. The results firstly demonstrated that it is possible to generate a new type of the BIV/HIV-1 chimeric virus containing BIV gag-pol gene
Dynamical perturbations and critical phenomena in Gauss-Bonnet-AdS black holes
We investigate the perturbations of charged scalar field in -dimensional
Gauss-Bonnet AdS black hole backgrounds. From the perturbation behaviors we
obtain the objective picture on how the high curvature influence the spacetime
perturbation and the condensation of the scalar hair. The high curvature
effects can also be read from the linear response function such as the
susceptibility and the correlation length, when the system approaches the
critical point. We find that the Gauss-Bonnet term does not affect the critical
exponents of the system and they still take the mean-field values.Comment: 13 pages, 5 figures, to appear in Phys. Lett.
Meta-analysis of ridge-furrow cultivation effects on maize production and water use efficiency
Ridge-furrow cultivation (RF) is a popular dryland agricultural technique in China, but its effects on maize yield, total water consumption during crop growing stage (ET), and water use efficiency (WUE) have not been systematically analyzed. Here we conducted a meta-analysis of the RF effects on maize yield, ET and WUE based on the data collected from peer-reviewed literature. Yield, ET and WUE varied with climate, soil and mulching management. Averaged across all the geographic locations, RF increased the yield and WUE of maize by 47 % and 39 %, respectively, but no effects on ET. An increase in the yield and WUE occurred under RF in regions regardless of the mean growing season air temperature (MT) or a mean precipitation during the growing season (MP), although there was a trend that RF is more beneficial under low MP. RF also decreased ET in regions with MT>12 °C. RF increased the yield and WUE in regions with medium or fine soil texture. RF increased the yield, ET, and WUE in regions with low soil bulk density (BD) (â€1.3 g cmâ3). But in areas where BD is larger than 1.3 g cmâ3, RF only increased the yield and WUE. RF increased the yield and WUE with or without mulching, but decreased ET when no mulching was used. Together, optimizing RF effects on the yield, ET and WUE in maize was largely dependent on environmental conditions and management practices
Crop yield and soil organic carbon under ridgeâfurrow cultivation in China: A meta-analysis
Ridgeâfurrow cultivation (RF) is a popular emerging technique that can increase crop productivity in dry areas. However, the efficacy of RF on crop yield and soil organic carbon (SOC) remains uncertain under different climate and management conditions. Here, we compiled data from 48 publications to evaluate the response of yield and SOC to RF in China. Overall, our meta-analysis showed that RF increased yield by 30.2%, but it had no effects on SOC. When differentiated based on different categories, yield and SOC varied by crop species, climate, soil textures, mulching management, and ridgeâfurrow patterns. RF increased the yield of wheat, maize, soybean, rape, linseed, potato, and SOC under soybean cultivation. Yield increase with RF was also consistent across temperature and precipitation. Yield increase was observed in all the soil textures. There were no RF effects on SOC under different soil textures. RF enhanced yields under no mulching, straw mulching and plastic film mulching, but increased SOC only in combination with straw mulching. A higher yield increase was observed under alternating small and large ridges (ASLR) than alternating ridges and furrows (AR). RF decreased SOC by 11.7% under AR, but had no effects on SOC under ASLR. Together, ASLR with straw mulching could increase yield and SOC in coarse soil texture regions with annual mean temperature >10°C and annual mean precipitation > 400 mm. This study showed the importance of considering local environmental conditions with management practices in identifying appropriate RF practices for improving crop productivity and soil carbon sequestration
DR*W201/P65 Tetramer Visualization of Epitope-Specific CD4 T-Cell during M. tuberculosis Infection and Its Resting Memory Pool after BCG Vaccination
In vivo kinetics and frequencies of epitope-specific CD4 T cells in lymphoid compartments during M. tuberculosis infection and their resting memory pool after BCG vaccination remain unknown.Macaque DR*W201 tetramer loaded with Ag85B peptide 65 was developed to directly measure epitope-specific CD4 T cells in blood and tissues form macaques after M. tuberculosis infection or BCG vaccination via direct staining and tetramer-enriched approach. The tetramer-based enrichment approach showed that P65 epitope-specific CD4 T cells emerged at mean frequencies of approximately 500 and approximately 4500 per 10(7) PBL at days 28 and 42, respectively, and at day 63 increased further to approximately 22,000/10(7) PBL after M. tuberculosis infection. Direct tetramer staining showed that the tetramer-bound P65-specific T cells constituted about 0.2-0.3% of CD4 T cells in PBL, lymph nodes, spleens, and lungs at day 63 post-infection. 10-fold expansion of these tetramer-bound epitope-specific CD4 T cells was seen after the P65 peptide stimulation of PBL and tissue lymphocytes. The tetramer-based enrichment approach detected BCG-elicited resting memory P65-specific CD4 T cells at a mean frequency of 2,700 per 10(7) PBL.Our work represents the first elucidation of in vivo kinetics and frequencies for tetramer-bound epitope-specific CD4 T cells in the blood, lymphoid tissues and lungs over times after M. tuberculosis infection, and BCG immunization
Prodrug Strategy for PSMA-targeted Delivery of TGX-221 to Prostate Cancer Cells
TGX-221 is a potent, selective, and cell membrane permeable inhibitor of the PI3K p110ÎČ catalytic subunit. Recent studies showed that TGX-221 has anti-proliferative activity against PTEN-deficient tumor cell lines including prostate cancers. The objective of this study was to develop an encapsulation system for parenterally delivering TGX-221 to the target tissue through a prostate-specific membrane aptamer (PSMAa10) with little or no side effects. In this study, PEG-PCL micelles were formulated to encapsulate the drug, and a prodrug strategy was pursued to improve the stability of the carrier system. Fluorescence imaging studies demonstrated that the cellular uptake of both drug and nanoparticles were significantly improved by targeted micelles in a PSMA positive cell line. The area under the plasma concentration time curve of the micelle formulation in nude mice was 2.27-fold greater than the naked drug, and the drug clearance rate was 17.5-fold slower. These findings suggest a novel formulation approach for improving site-specific drug delivery of a molecular-targeted prostate cancer treatment
The Easterlin paradox of entrepreneurs during China's economic transition
Abstract This paper investigates the determinants and the time pattern of the subjective wellâbeing of private business owners. We find that both personal and enterpriseâlevel factors have a significant influence on subjective status of private business owners. Meanwhile, we find supportive evidence of Easterlin paradox among Chinese private entrepreneurs: both personal income and operating revenue enhance subjective status in a certain period, but subjective status declines as time goes by, even as incomes continue to rise. A further OaxacaâBlinder decomposition suggests that the competition and provincial factors are the keys to explaining the paradox. Finally, we try to verify the positive effect of political connection on entrepreneurs' subjective status to provide some helpful advice for the government
Pretreatment of Ascorbic Acid Inhibits MPTP-Induced Astrocytic Oxidative Stress through Suppressing NF-ÎșB Signaling
Astrocytes are a major constituent of the central nervous system (CNS). Astrocytic oxidative stress contributes to the development of Parkinsonâs disease (PD). Maintaining production of antioxidant and detoxification of reactive oxygen and nitrogen species (ROS/RNS) in astrocytes is critical to prevent PD. Study has illuminated that ascorbic acid (AA) stimulates dopamine synthesis and expression of tyrosine hydroxylase in human neuroblastoma cells. However, the role and regulatory mechanisms of AA on detoxification of astrocytes are still unclear. The purpose of our study is in-depth study of the regulatory mechanism of AA on detoxification of astrocytes. We found that AA pretreatment decreased the expression of ROS and inducible nitric oxide synthase (iNOS) in MPP+-treated astrocytes. In contrast, the expression levels of antioxidative substancesâincluding superoxide dismutase (SOD), glutathione (GSH), and glutamate-cysteine ligase modifier (GCLM) subunitâwere upregulated after AA pretreatment in MPP+-treated astrocytes. However, inhibition of NF-ÎșB prevented such AA induced increases in antioxidative substances following MPP+ treatment in astrocytes, suggesting that AA improved antioxidative function of astrocytes through inhibiting NF-ÎșB-mediated oxidative stress. Furthermore, in vivo studies revealed that AA preadministration also suppressed NF-ÎșB and upregulated the expression levels of antioxidative substances in the midbrain of MPTP-treated mice. Additionally, pretreatment of AA alleviated MPTP-induced PD-like pathology in mice. Taken together, our results demonstrate that preadministration of AA improves the antioxidative function of astrocytes through suppressing NF-ÎșB signaling, following alleviated the pathogenesis of PD which induced by MPTP. Hence, our findings elucidate a novel protective mechanism of AA in astrocytes
Linalool Inhibits MCF-7 Tumor Growth in a Xenograft Model by Apoptosis Induction and Immune Modulation
In this study, the anti-cancer activity of linalool was investigated in MCF-7 breast cancer-bearing mice. Natural killer (NK) and B cell populations in peripheral blood were studied by flow cytometry. The expressions of proliferating cell nuclear antigen (PCNA) and Ki-67 in xenograft tumors were evaluated by immunohistochemistry. Terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay was performed to investigate apoptosis induction in an in vivo model. The results indicated that linalool possesses an inhibitory effect on breast cancer growth in the xenograft model. Linalool reduced B cell counts, but increased NK cell counts in mice peripheral blood. The immunosignals of PCNA and Ki-67 were significantly lower in the linalool treatment group than those of the control group. The TUNEL assay showed that linalool significantly induced apoptosis compared to the control group. The findings of this study provide insight and evidence on the antiproliferative activity of linalool on human breast cancer
Effect of Soluble Salt Loss via Spring Water on Irrigation-Induced Landslide Deformation
Landslide exposes the previously blocked groundwater discharge. High concentrations of soluble salt form salt sinters that can be observed near discharge passages. Based on existing laboratory investigation results of soil leaching and shearing reported in the literature, the effect of the soluble salt loss via spring water on irrigation-induced landslide deformation was studied under large-scale conditions. During our field investigation of landslides in the Heitai terrace of the Yellow River’s upper reaches in Gansu Province, China, 35 spring outlets were found, and the Heitai terrace was divided into five subareas, based on the difference in spring flow. Deformation data for the terrace were obtained by small baseline subset technology (SBAS-InSAR). These data were analyzed in combination with the amount of soluble salt loss, to explore the correlation between the deformation of the landslide and the soluble salt loss in the loess irrigation area. The results showed that the cumulative deformation and the loss of soluble salt were increasing continuously in the terrace. Although the increasing intensity of each subarea was different, the changing intensity of the two during the corresponding monitoring period was highly consistent. The statistical analysis revealed a strong positive correlation between the accumulated loss of soluble salt via spring water and the accumulated displacement of the terrace edge (p < 0.01). After the slope k between the two was tested by the Grubbs test and t-test, the k was no abnormality (α = 0.05) and difference (Sig > 0.05), further providing the basis for confirming the existence of this positive correlation. When the loss of soluble salt in rock and soil increased gradually, the accumulated deformation of the terrace edge also increased continuously. The findings of this study are of great significance for understanding the formation mechanism of landslides and the identifying landslide revival in irrigation areas of the Loess Plateau