206 research outputs found

    Multiple male and female reproductive strategies and the presence of a polyandric mating system in the termite Reticulitermes labralis (Isoptera:Rhinotermitidae)

    Get PDF
    Reproductive systems of termite colonies may involve the number of individuals in the reproductive caste and the copulatory selectivity of reproductive individuals (i.e., polyandry or polygamy), both of which directly impact the fertility and genetic diversity of the colony. Polygamy is widespread in the lower termites, whereas polyandry appears to be mostly absent in termites. In this paper, the differentiation of male and female neotenics were observed in orphaned experimental colonies of the subterranean termite Reticulitermes labralis. The artificial orphaned colonies began to produce neotenics a week after colony establishing, with more neotenics appearing in the same group over time. Finally, each experimental group reserved multi-neotenics that consisted of male and female neotenic individuals. Our results demonstrated that these neotenic individuals retained in the colony participated in reproduction. A genetic analysis at four microsatellite loci showed that in addition to the conspicuous morphologically male reproductives, there were inconspicuous males or workers that had copulated with the females in the orphaned colony. Multiple male and female reproductive individuals existed together in a single colony, and one female neotenic could mate with several male reproductives in a short time. Thus, multiple male and female reproductive systems and a polyandric mating system are present in R. labralis

    Analysis of primary resistance mutations to HIV-1 entry inhibitors in therapy naive subtype C HIV-1 infected mother– infant pairs from Zambia

    Get PDF
    Background—Small molecular CCR5 inhibitors represent a new class of drugs for treating HIV-1 infection. The evaluation of the primary resistance mutations associated with entry inhibitors during HIV-1 perinatal transmission is required because they may have a profound impact on the clinical management in MTCT. Objectives—To evaluate the primary resistance mutations to maraviroc and vicriviroc during perinatal transmission and analyze the sensitivity of Env derived from mother–infant pairs to maraviroc. Study design—Nine MIPs infected by subtype C HIV-1 were recruited to analyze the prevalence and transmission of primary resistance mutations to maraviroc and vicriviroc. Moreover, Env derived from six MIPs were employed to construct provirus clones and to analyze the sensitivity to maraviroc. Results—Mutations A316T, conferring partial resistance to maraviroc, T307I and R315Q, both conferring partial resistance to vicriviroc are prevalent in mother and infant cohorts, indicating the transmission of primary resistance mutations during HIV-1 perinatal transmission. However, the mutations of acutely infected mothers seem to directly transmit to their corresponding infants, while some mutations at low frequency of chronically infected mothers would be lost during transmission. Moreover, provirus clones derived from acutely infected MIPs are less susceptible to maraviroc than those from chronically infected MIPs. Conclusions—Our study suggests that the transmission mode of primary resistance mutations and the sensitivity to maraviroc are dependent on infection status of MIPs either acutely or chronically infected. These results may indicate that higher dose of maraviroc could be needed for treatment of acutely infected MIPs compared to chronically infected MIPs

    Analysis of primary resistance mutations to HIV-1 entry inhibitors in therapy naive subtype C HIV-1 infected mother– infant pairs from Zambia

    Get PDF
    Background—Small molecular CCR5 inhibitors represent a new class of drugs for treating HIV-1 infection. The evaluation of the primary resistance mutations associated with entry inhibitors during HIV-1 perinatal transmission is required because they may have a profound impact on the clinical management in MTCT. Objectives—To evaluate the primary resistance mutations to maraviroc and vicriviroc during perinatal transmission and analyze the sensitivity of Env derived from mother–infant pairs to maraviroc. Study design—Nine MIPs infected by subtype C HIV-1 were recruited to analyze the prevalence and transmission of primary resistance mutations to maraviroc and vicriviroc. Moreover, Env derived from six MIPs were employed to construct provirus clones and to analyze the sensitivity to maraviroc. Results—Mutations A316T, conferring partial resistance to maraviroc, T307I and R315Q, both conferring partial resistance to vicriviroc are prevalent in mother and infant cohorts, indicating the transmission of primary resistance mutations during HIV-1 perinatal transmission. However, the mutations of acutely infected mothers seem to directly transmit to their corresponding infants, while some mutations at low frequency of chronically infected mothers would be lost during transmission. Moreover, provirus clones derived from acutely infected MIPs are less susceptible to maraviroc than those from chronically infected MIPs. Conclusions—Our study suggests that the transmission mode of primary resistance mutations and the sensitivity to maraviroc are dependent on infection status of MIPs either acutely or chronically infected. These results may indicate that higher dose of maraviroc could be needed for treatment of acutely infected MIPs compared to chronically infected MIPs

    Single-crystal silver nanowires: Preparation and Surface-enhanced Raman Scattering (SERS) property

    Full text link
    Ordered Ag nanowire arrays with high aspect ratio and high density self-supporting Ag nanowire patterns were successfully prepared using potentiostatic electrodeposition within the confined nanochannels of a commercial porous anodic aluminium oxide (AAO) template. X-ray diffraction and selected area electron diffraction analysis show that the as-synthesized samples have preferred (220) orientation. Transmission electron microscopy and scanning electron microscopy investigation reveal that large-area and ordered Ag nanowire arrays with smooth surface and uniform diameter were synthesized. Surface-enhanced Raman Scattering (SERS) spectra show that the Ag nanowire arrays as substrates have high SERS activity.Comment: 5 pages, 4 figure

    The specific capacitance of sol–gel synthesised spinel MnCo2O4 in an alkaline electrolyte

    Get PDF
    PublishedArticleIn this work, high performance spinel MnCo2O4 electrode was fabricated via a facile sol–gel method and its capacitive behavior was successfully investigated in alkaline electrolyte. MnCo2O4 electrode was characterized by means of powder X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscope (TEM). The pseudo capacitive behavior of spinel MnCo2O4 was widely investigated in 2 M KOH aqueous electrolyte using cyclic voltammetry (CV), galvanostatic charge-discharge test, and electrochemical impedance spectroscopy (EIS). As a result, the spinel MnCo2O4 exhibited excellent porous structure and the highest specific capacitance of 405 F g−1 was achieved at a current density of 5 mA cm−2. In addition, the spinel MnCo2O4 displayed desirable stability in alkaline electrolyte during long-term cycles with a cycling efficiency of 95.1% over 1,000 cycles. The high specific capacitance and excellent cycling ability of MnCo2O4 show promise for its application in supercapacitors.National Natural Science Foundation of ChinaChinese Ministry of EducationNatural Science Funds for Distinguished Young Scholars of Gansu ProvinceProgram for Hongliu Outstanding Talents in Lanzhou University of Technolog

    A sol-gel process for the synthesis of NiCo2O4 having improved specific capacitance and cycle stability for electrochemical capacitors

    Get PDF
    PublishedArticleHigh performance nickel cobaltite (NiCo2O4) with ultrahigh capacitance is synthesized by a facile sol-gel process and then calcined at 300◦C. The structure and morphology is characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscope (TEM), and nitrogen adsorption/desorption experiments.Amesoporous structure with high specific surface area is obtained. Electrochemical properties are investigated by cyclic voltammetry (CV), galvanostatic charge/discharge, and electrochemical impedance spectroscopy (EIS). The NiCo2O4 exhibits excellent electrochemical performance. The highest specific capacitance of 1128 F g−1 is achieved at a current density of 5 mA cm−2 and 92.5% of the initial specific capacitance remained after 1000 cycles. NiCo2O4 prepared by this scale-able route could be a promising electrode material for electrochemical capacitors.National Natural Science Foundation of ChinaKey Project of Chinese Ministry of EducationNatural Science Funds for Distinguished Young Scholars of Gansu Provinc

    High level expression of human epithelial β-defensins (hBD-1, 2 and 3) in papillomavirus induced lesions

    Get PDF
    BACKGROUND: Epithelial defensins including human β-defensins (hBDs) and α-defensins (HDs) are antimicrobial peptides that play important roles in the mucosal defense system. However, the role of defensins in papillomavirus induced epithelial lesions is unknown. RESULTS: Papilloma tissues were prospectively collected from 15 patients with recurrent respiratory papillomatosis (RRP) and analyzed for defensins and chemokine IL-8 expression by quantitative, reverse-transcriptase polymerase chain reaction (RT-PCR) assays. HBD-1, -2 and -3 mRNAs were detectable in papilloma samples from all RRP patients and the levels were higher than in normal oral mucosal tissues from healthy individuals. Immunohistochemical analysis showed that both hBD-1 and 2 were localized in the upper epithelial layers of papilloma tissues. Expression of hBD-2 and hBD-3 appeared to be correlated as indicated by scatter plot analysis (r = 0.837, p < 0.01) suggesting that they were co-inducible in papillomavirus induced lesions. Unlike hBDs, only low levels of HD5 and HD6 were detectable in papillomas and in oral mucosa. CONCLUSION: Human β-defensins are upregulated in respiratory papillomas. This novel finding suggests that hBDs might contribute to innate and adaptive immune responses targeted against papillomavirus-induced epithelial lesions

    Contribution of recycled moisture to local precipitation in the inland Heihe River Basin

    Get PDF
    Recycled moisture contributed by continental evaporation and transpiration plays an important role in regulating the hydrological processes and atmospheric humidity budget in arid inland river basins. However, knowledge of moisture recycling within many large inland basins and the factors that control moisture recycling is generally lacking. Based on a three-component isotopic mixing model, we assessed the characteristics of moisture recycling in China’s semi-arid Heihe River Basin. During the active growing season, almost half of the precipitation in the upper reaches was provided by local moisture recycling, and the main contribution came from transpiration. In the middle reaches, almost half of the precipitation in the artificial oasis and the desert-oasis ecotone was also provided by local moisture recycling, and the transpiration fraction (fTr) and evaporation fraction (fEv) of the artificial oasis differed from those of the desert-oasis ecotone. In the lower reaches, less than 25% of the precipitation was provided by local moisture recycling. Mean fTr values were relatively low in the Gobi (15.0%) in the middle reaches and in the riparian forest at Ejina (25.6%) in the lower reaches. The positive correlations between fTr and both precipitation and relative humidity suggest that higher precipitation and relative humidity promote transpiration fraction, whereas higher vapor pressure deficit reduces transpiration fraction. The positive correlation between fEv and temperature and vapor pressure deficit, and the negative correlation between fEv and relative humidity indicate that higher temperature and vapor pressure deficit promotes evaporation fraction, whereas higher relative humidity reduces the evaporation fraction. Our results show that contributions of recycled moisture (especially transpiration) to local precipitation play an important role in regional water resource redistribution in the arid and semi-arid region of northwestern China

    Synthesis and characterisation of M3V2O8 (M = Ni or Co) based nanostructures: a new family of high performance pseudocapacitive materials

    Get PDF
    Binary metal oxides have recently attracted extensive attention from researchers in the energy storage field due to their multiple oxidation states and high energy density. In the present work, Ni3V2O8, Co3V2O8, and the Ni3V2O8/Co3V2O8 nanocomposite are designed and synthesized as a new class of high performance electrode material for supercapacitors. Ni3V2O8 and Co3V2O8 show a structure comprising nanoflakes and nanoparticles, respectively. The Ni3V2O8/Co3V2O8 nanocomposite is prepared by growing Co3V2O8 nanoparticles on the surface of Ni3V2O8 nanoflakes. The composite inherits the structural characteristics and combines the pseudocapacitive benefits of both Ni3V2O8 and Co3V2O8, showing higher specific capacitance than Co3V2O8 and superior rate capability as well as better cycle stability to Ni3V2O8. The dependence of pseudocapacitive properties of the Ni3V2O8/Co3V2O8 nanocomposite on the Ni/Co mass ratio is also investigated, indicating that the high specific capacitance of the composite is contributed by Ni3V2O8, while its excellent rate capability and cycle stability can be attributed to the Co3V2O8 component.National Natural Science Foundation of ChinaChinese Ministry of EducationNatural Science Funds for Distinguished Young Scholars of Gansu Provinc
    • …
    corecore