[Feasibility and effectiveness of application of internet-based HIV testing in men who have sex with men]

Objective: To evaluate the feasibility and effectiveness of the application of internet-based HIV testing in men who have sex with men (MSM) in practical application and provide evidence for its application in the future. Methods: MSM who visited the internet-based intervention platform for at least one time from June to December 2020 were selected for the study. The information about platform visit, the number of self-test kits provided, the basic characteristics of the MSM and their satisfactory level were collected. And multivariable logistic regression analyses were conducted to identify the potential factors associated with the reporting of self-test results. Results: By the end of December 31^th, 2020, a total of 132 267 platform visits had been recorded, and 3 511 HIV self-test kits had been provided upon the MSM's requests, and 3 237 MSM (92.2%) reported self-test results. The HIV positive rate was 2.4% (69/2 855) and the confirmation rate of positive HIV test results was 86.7% (52/60). The MSM who asked for self-test kits online were mainly aged ≤30 years, had education level of college or above, and found their sexual partners through internet or dating software. Multivariable logistic regression analyses showed that repeat of online HIV self-test kits application (OR=3.50,95%CI:2.10-5.83), guarantee deposit of 50 yuan at application (OR=2.55,95%CI:1.33-4.89), monthly economic income 1-3 000 yuan (OR=1.54,95%CI:1.05-2.28) or no income (OR=1.71,95%CI:1.20-2.42) and online sexual partners finding (OR=1.49,95%CI:1.13-1.95) were associated with higher reporting rate of self-test results. The satisfactory rate the MSM to the service of platform was 99.5% (217/218). Conclusions: The study confirmed the feasibility and effectiveness of internet-based intervention for HIV tests in MSM, which could promote the self-test of HIV in MSM and facilitate the early detection of HIV infection through social media platforms and multi-channel promotion.

Effect of Interleukin-17 gene on glomerular ultrastructure and podocyte injury in adriamycin nephropathy rat models

The aim of this study was to investigate the mechanism of interleukin-17 (IL-17) gene in renal tissues of rats suffering from adriamycin (ADM) nephropathy and its effect on the expression level of characteristic proteins, such as Podocalyxin and Nephrin, in podocytes. Sprague-Dawley (SD) rats were randomly divided into a control group (treated with normal saline) and an ADM group (treated with adriamycin). ADM model rats were transfected with lentivirus and divided into a transfection group (transfected with recombinant plasmid IL-17-shRNA) and a negative control group (transfected with plasmid shNC). Coomassie brilliant blue G-250 (CBB) method was adopted to detect the levels of albumin in urine to validate the model. The ultrastructure of rat glomeruli was observed, and the ratio of T helper 17 cells/regulatory T cells (Th17/Treg) was measured by flow cytometry (FCM). The expression levels of IL-17, forkhead box P3 (Foxp3), Nephrin, and Podocalyxin were detected by real-time quantitative PCR (RT-qPCR) and western blot analysis. Results of the study showed that the proteinuria content of the ADM group was significantly higher than that of the control group (P<0.05). In the ADM group, the glomerular basement membrane had uneven thickness and incomplete structure, which showed foot process fusion and electron dense accumulation. However, the glomerular basal membrane in the transfected rats was thin and intact, and a small amount of epithelial foot process fusion and electron density accumulation were observed. The percentages of Th17 cells and IL-17 levels in the ADM group were significantly higher than those in the control group, while the percentages of Treg cells, Foxp3, Nephrin, and Podocalyxin levels were significantly lower than those in the control group (P<0.05). The percentages of Th17 cells, IL-17, Nephrin, and Podocalyxin in the transfection group were significantly higher than those in the ADM group and the negative control group, while the percentages of Treg cells and Foxp3 were significantly lower than those in the ADM group and the negative control group (P<0.05). The results of this study showed that abnormal activation of Th17/IL-17 cells caused podocyte injury and promoted the occurrence and progression of ADM nephropathy. In addition, inhibition of IL-17 gene expression could improve the imbalance of number of Th17 and Treg cells, which may be potentially applied in treatment of patients with primary nephrotic syndrome (PNS).

Anti-aging gene Klotho ameliorates diabetic nephropathy in mice by inhibiting FGF2 signaling pathway

The aim of this study was to observe the expression of Klotho in renal tissues of mice with diabetic ne¬phropathy (DN), and to further explore the effect of Klotho on DN in mice and its mechanism. The 10-week-old mice in this experiment were divided into three groups: heterozygous db/+ mouse group (db/+ group, n=20), homozygous db/db mouse group (db/db group, n=20) and homozygous db/db mice + Klotho group (db/db + Klotho group, n=20). Firstly, Western blotting and immunohistochemical staining were applied to detect the protein expression of Klotho in the renal tissues of diabetic and non-diabetic mice of different ages. Finally, the protein expressions of fibroblast growth factor 2 (FGF2) and E-cadherin in the renal tissues of mice in each group were examined by Western blotting. The protein expression level of Klotho in the renal tissues of mice aged 10 and 16 weeks in the db/db group was remarkably lower than that in yhedb/+ group. In addition, it was found that db/db + Klotho group exhibited a prominently lower degree of interstitial fi¬brosis and content of Collagen I and Collagen III in the renal tissues than db/db group. Furthermore, it was revealed that the overexpression of Klotho could significantly repress the protein expression level of FGF2 but elevate that of E-cadherin in the renal tissues of DN mice. Klotho protein may ameliorate the renal injury and fibrosis in diabetic mice by inhibiting FGF2, so it is expected to become a targeted drug for DN.

Glyphosate biodegradation and potential soil bioremediation by Bacillus subtilis strain Bs-15

Glyphosate and glyphosate-containing herbicides have an adverse effect on mammals, humans, and soil microbial ecosystems. Therefore, it is important to develop methods for enhancing glyphosate degradation in soil through bioremediation. We investigated the potential of glyphosate degradation and bioremediation in soil by Bacillus subtilis Bs-15. Bs-15 grew well at high concentrations of glyphosate; the maximum concentration tolerated by Bs-15 reached 40,000 mg/L. The optimal conditions for bacterial growth and glyphosate degradation were less than 10,000 mg/L glyphosate, with a temperature of 35°C and a pH of 8.0. Optimal fermentation occurred at 180 rpm for 60 h with an inoculum ratio of 4%. Bs-15 degraded 17.65% (12 h) to 66.97% (96 h) of glyphosate in sterile soil and 19.01% (12 h) to 71.57% (96 h) in unsterilized soil. Using a BIOLOG ECO plate test, we observed no significant difference in average well color development values between the soil inoculated with Bs-15 and the control soil before 72 h, although there was a significant difference (P < 0.01) after 72 h. In the presence of Bs-15, the 5 functional diversity indices (Shannon index, Shannon uniformity, Simpson index, McIntosh index, and McIntosh uniformity) were greater (P < 0.01) compared with the control soil. These results indicate that Bs-15 could be used to alleviate contamination from glyphosate-containing herbicides, increasing the microbial functional diversity in glyphosate-contaminated soils and thus enhancing the bioremediation of glyphosate-contaminated soils.

A cultured endophyte community is associated with the plant Clerodendrum inerme and antifungal activity

Fungal endophytes live in the inner tissues of Clerodendrum inerme and may be significant resources for new chemicals in drug discovery. A total of 242 endophytic fungi were recovered from 602 sample segments of C. inerme; 66 were purified. The 66 fungi belonging to 16 taxa and 11 genera (Alternaria, Nigrospora, Bartalinia, Pestalotiopsis, Fusarium, Mycoleptodiscus, Trichoderma, Phomopsis, Diaporthe, Lasiodiplodia, and Curvularia) were identified by morphological characteristics and fungal internal transcribed spacer sequences. The most abundant genera were Alternaria and Lasiodiplodia. Some of the endophytes exhibited tissue specificity. The colonization frequencies of endophytes in the stems were evidently higher than those in the roots and leaves. The crude ethyl acetate extracts were tested against 6 endophytes isolated from C. inerme. Three of 10 (33.3%) endophytes, which were identified as Phomopsis sp, Curvularia sp, and Mycoleptodiscus sp, displayed distinct antifungal activity against ≥3 tested fungi. To our knowledge, this is the first report of an endophytic community associated with C. inerme in China and its antifungal activity in vitro.

Identification of a symbiotic fungus from blue-green alga and its extracellular polysaccharide

A previously unknown symbiotic fungus DT06 has been isolated from the single-celled blue-green alga Chroococcus sp. The sequences of ITS1, 5.8S rDNA and ITS2 regions of DT06 have a high similarity with that of Simplicillium (98%), which is closely related to Simplicillium lanosoniveum based on further phylogenetic analysis. However, DT06 produces unusual exocellular crystals with its conidium size twice that of S. lanosoniveum. Hence, DT06 is proposed to be a varietas of S. lanosoniveum and named as S. lanosoniveum var. Tianjinienss. Dong. (Type specimen was deposited at China General Microbiological Culture Collection Center, Number: CGMCC4460.). The striking character of DT06 is its massive production of a unique extracellular polysaccharide, which is composed of glucose and galactose and linked by 1-4 and 1-6 glycoside bonds according to UV, IR and NMR analysis. Therefore, DT06 may represent a new source of bioactive products, and also, its unusual symbiotic partnership with blue-green algae provides a model for investigating the interaction between photoautotrophic and heterotrophic micro-organisms in aquatic ecosystems.

SIGNIFICANCE AND IMPACT OF THE STUDY

A novel fungus (Simplicillium) symbiotic with a single-celled blue-green alga Chroococcus sp. and its major primary metabolite have been isolated and identified. These findings broaden the scope of symbiotic fungi and provide a unique extracellular polysaccharide with potential applications in food industry.

Spectrally peaked electron beams produced via surface guiding and acceleration in femtosecond laser-solid interactions

Highly collimated MeV electron beam guiding has been observed along the target surface following the interaction of bulk target irradiation by femtosecond laser pulses at relativistic intensities. The beam quality is shown to depend critically on the laser contrast: With a ns prepulse, the generated electron beam is well concentrated and intense, while a high laser contrast produces divergent electron beams. In the case of large preplasma scale lengths, tunable guiding and acceleration of the target surface electrons is achieved by changing the laser incident angle. By expanding the preplasma scale length to several hundred micrometers, we obtained MeV spectrum-peaked electron beams with a 100 pC per laser pulse and divergence angles of only 3°. This technique suggests a stable method of injection of elections into a variety of accelerator designs.

X-ray lasers from Inner-shell transitions pumped by the Free-electron laser

We present a approach of generating femtosecond coherent x-ray pulses by using the self-amplified free-electron laser (SASE FEL) to pump the inner-shell x-ray lasers (ISXRL's). Theoretical simulations are performed. The gain characteristics are analyzed for the two representative schemes of inner-shell x-ray transitions, ie. the self-terminated x-ray lasing (1s)(-1)-->(2p)(-1) (lambda = 4.5nm) in carbon (Z = 6) and the quasi-stationary x-ray lasing (2p)(-1 )-->(3s)(-1) (lambda = 4.1nm) in calcium (Z = 20). When the 10fs x-ray FEL pulses are available at 284eV and 360eV with the pumping intensities of 1.2x10(15)W/cm(2) and 2x10(17)W/cm(2) for C and Ca, respectively, a net gain of 140cm(-1) can be predicted. Using a one-dimensional model, the properties of output ISXRL's are studied. By the Carbon ISXRL scheme, the multi-spiky SASE FEL x-ray pulse with chaotic temporal structure is smoothed to a temporally continuous x-ray pulse with a comparable duration but at a different wavelength. The Calcium scheme, can be used to create one single x-ray laser pulse with a duration as short as 2fs. The spectral bandwidth of the output ISXRL's is an order of 10 (-3), which is one order narrower than that of the SASE FEL's.

Study of x-ray emission enhancement via a high-contrast femtosecond laser interacting with a solid foil

We observed the increase of the conversion efficiency from laser energy to Kalpha x-ray energy (eta(K)) produced by a 60 fs frequency doubled high-contrast laser pulse focused on a Cu foil, compared to the case of the fundamental laser pulse. eta(K) shows a strong dependence on the nonlinearly modified rising edge of the laser pulse. It reaches a maximum for a 100 fs negatively modified pulse. The hot electron efficient heating leads to the enhancement of eta(K). This demonstrates that high-contrast lasers are an effective tool for optimizing eta(K), via increasing the hot electrons by vacuum heating.

Valley density profile for highly efficient x-ray lasers with good beam quality

A plasma with a valley density profile at the required electron density for high-gain operation of an x-ray laser could be obtained using a normally incident 300 ps laser pulse followed by a grazing-incident 300 ps laser pulse. Sudden heating of the valley plasma region by another grazing-incident 300 fs laser pulse would then yield a highly efficient x-ray laser beam with a deflecting angle of 2 mrad and a divergence angle of 4 mrad. Saturation operation of the x-ray laser beam at 32.6 nm could be achieved with a total pump energy of less than 100 mJ.

Optimization of ion acceleration in the interaction of intense femtosecond laser pulses with ultrathin foils

Ion emission is investigated using particle-in-cell simulations where a Gaussian laser pulse with duration 50 fs and intensity 1.37x10(19) W/cm(2) is incident obliquely onto ultrathin solid foils. When the foil is thicker than 0.1 microm, it is opaque to the laser light and the highest ion energy drops exponentially with target thickness. Optimization of ion acceleration occurs for a target with a thickness of 0.04 microm when it becomes transparent to the laser light. The behaviors of the high-energy electrons oscillating in the charge separation potential at the front and the rear of the target, as well as the enhanced electron acceleration in the laser pulse, play dominant roles for the observed features of ion emission. The relation of the optimal target thickness with parameters of the incident laser pulse and foil targets is also discussed.

Effects of laser polarization on jet emission of fast electrons in femtosecond-laser plasmas

Effects of laser polarization on fast electron emission are studied from an aluminum target irradiated by ultrashort laser pulses at 2 x 10(16) W/cm(2). Jet emission of outgoing fast electrons collimated in the polarization direction is observed for s-polarized laser irradiation, whereas for p-polarized irradiation highly directional emission of outgoing fast electrons is found in the direction close to the normal of the target. The behavior of ingoing fast electrons into the target for s- and p-polarized irradiation is also investigated by observing x-ray bremsstrahlung radiation at the backside of the target.

Hot electrons in the interaction of femtosecond laser pulses with foil targets at a moderate laser intensity

Characteristics of hot electrons produced in the interaction of femtosecond laser pulses with foil targets were investigated at a moderate laser intensity. Both outgoing and ingoing hot electrons from the femtosecond laser plasma were studied. A collimated jet of outgoing hot electrons was observed in the target normal direction. An ingoing energetic hot-electron beam was found in the laser propagation direction, while the low-energy ingoing electrons spread into wider cone angle due to the collisional effects in the plasma and target material. These observations were supported by three-dimensional Monte Carlo simulations. The hot-electron temperature obtained from electron spectra and absorption experiments implies that resonance absorption is partially responsible for the generation of hot electrons.

Absorption of femtosecond laser pulses in interaction with solid targets

We have studied the effects of the plasma density scale length on the absorption mechanism of the femtosecond (fs) laser pulses interacting with solid targets. Experiments and particle-in-cell (PIC) simulations demonstrate that the vacuum heating is the main absorption in the plasma in the interaction of fs laser pulses with solid targets when no prepulses are applied. The energy spectrum of hot electrons ejected out of or injected into the plasma show a bitemperature distribution. While the first temperature of the two groups of hot electrons can be attributed to the "pull-and-push" exertion of the laser field, the second temperature refers to the electrons accelerated by the static part (in front of the target) and the oscillating part (in the plasma layer) of the laser-induced electric field, respectively. PIC simulations also show that with an appropriate density scale length, the femtosecond laser energy can be absorbed locally through different mechanisms.

Experimental study of a subpicosecond pulse laser interacting with metallic and dielectric targets

We have studied laser absorption, hot electron emission, and the energy spectrum of hot electrons produced during the interaction of a 150 fs, 5 mJ, 800 nm p-polarized laser pulse at 8x10(15) W/cm(2) with metallic and dielectric target materials. Because dielectric targets are much less conductive, the charge separation potential in dielectric targets is higher than that of metallic targets. This leads to a smaller laser absorption, fewer emitted electrons, and a lower hot electron temperature in dielectric than in metallic targets.

Study on micronucleus frequency in peripheral lymphocytes in workers of match factories

This paper reports the results of the study of micronucleus frequency in peripheral lymphocytes in workers exposed to soft wood dust (poplar and linden wood) in match factories. 298 workers exposed to soft wood dust in three match factories were defined as exposure group and 45 waiters in a restaurant as control group. The frequency of micronucleus in peripheral lymphocytes was examined and the control's 95% confidential upper limit >, 4/1000 was defined as the standard to determine the positivity. The positive rate in the exposure group was 36.2% while that in the control group was only 4.4%; the difference is significant (P < 0.01). As the coefficient of correlation between length of work and positive rate was 0.86 (P < 0.01), a dose/time-response is in existence. Meanwhile, the analysis of relation between quantity of smoking and positive rate eliminated the effect of smoking on variation of positive rates. In this paper, we also discussed the relation between positive rates and wood dust concentrations in different worksites and we think that the volatile and unsteady substances in soft wood dust are micronucleus-inducing matters.