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Background The Corona Virus Disease 2019 (COVID-19) pandemic has raised concerns regarding its potential impact on male reproductive health. However, the impact of COVID-19 on sperm quality remains uncertain. This retrospective study aimed to investigate the short-term and relatively long-term effects of COVID-19 infection on sperm quality. Methods A total of 85 males with fertility requirements, who underwent semen evaluation at Guilin People’s Hospital between June 2022 and July 2023, were included in the study. Changes in semen parameters were analyzed across three specific timeframes: within 6 months before COVID-19 infection, within 3 months after COVID-19 infection, and 3–6 months after COVID-19 recovery. Results The results revealed that the sperm concentration and total sperm number were significantly lower after infection compared to before, while in the recovery period, the sperm concentration, total sperm count, progressive motility, and normal morphology significantly increased. Comparing the three periods, the most significant difference was observed in sperm concentration, which exhibited a significant decrease after infection but returned to normal levels after recovery from COVID-19. Conclusions These findings suggest that COVID-19 may exert some impact on sperm quality, particularly evidenced by decreased sperm concentration post-infection. Fortunately, these effects on semen parameters appear to be temporary, with gradual restoration of semen parameters within 3–6 months after recovery. However, further research is needed to explore the underlying mechanisms and long-term implications of these observed changes in semen parameters.

Photothermal conversion material that generates thermal energy from sunlight is expected to be a promising technology for harvesting and conversion of clean solar energy. However, its photothermal conversion will be affected due to the surface contamination by dirt in outdoor applications, which greatly reduces the solar energy absorption. Herein, a superhydrophobic photothermal conversion fabric was fabricated through layer-by-lay self-assembly of carbon nanotubes (CNTs) on the surface of fibers, and followed by post-treatment with polydimethylsiloxane (PDMS). The CNTs not only impart to the fabric high photothermal conversion capability, but also construct roughening structures on the fiber surface. Consequently, the as-prepared fabric could be rapidly heated to 89.8 °C under one sun (1 kW/m2) irradiation, and showed excellent superhydrophobicity with contact angle 165° ± 0.9° and rolling angle 0.6° ± 0.2°. Meanwhile, the fabric possessed excellent stability to organic solvent, acid/alkali solutions, and UV irradiation. Importantly, the superhydrophobic self-cleaning property prevents the photothermal coating from contamination to guarantee the durability of the photothermal conversion efficiency.Graphic abstract

Molecular dynamics simulation is a common method to help humans understand the microscopic world. The traditional general‐purpose high‐performance computing platforms are hindered by low computational and power efficiency, constraining the practical application of large‐scale and long‐time many‐body molecular dynamics simulations. In order to address these problems, a novel molecular dynamics accelerator for the Tersoff potential is designed based on field‐programmable gate array (FPGA) platforms, which enables the acceleration of LAMMPS using FPGAs. Firstly, an on‐the‐fly method is proposed to build neighbor lists and reduce storage usage. Besides, multilevel parallelizations are implemented to enable the accelerator to be flexibly deployed on FPGAs of different scales and achieve good performance. Finally, mathematical models of the accelerator are built, and a method for using the models to determine the optimal‐performance parameters is proposed. Experimental results show that, when tested on the Xilinx Alveo U200, the proposed accelerator achieves a performance of 9.51 ns/day for the Tersoff simulation in a 55,296‐atom system, which is a 2.00×$$ \\times $$ increase in performance when compared to Intel I7‐8700K and 1.70×$$ \\times $$ to NVIDIA Tesla K40c under the same test case. In addition, in terms of computational efficiency and power efficiency, the proposed accelerator achieves improvements of 2.00×$$ \\times $$ and 7.19×$$ \\times $$ compared to Intel I7‐8700K, and 4.33×$$ \\times $$ and 2.11×$$ \\times $$ compared to NVIDIA Titan Xp, respectively. We propose an FPGA‐based molecular dynamics accelerator with customized computing architecture for the Tersoff potential. The designed accelerator achieves good acceleration of the Tersoff potential, showing the potential of extending LAMMPS to FPGAs for high power efficiency and high computational efficiency.

To identify the features of Chinese genetic prion diseases. Suspected Creutzfeldt-Jakob disease (CJD) cases that were reported under CJD surveillance were diagnosed and subtyped using the diagnostic criteria issued by the WHO. The general information concerning the patient, their clinical, MRI and EEG data, and the results of CSF 14-3-3 and PRNP sequencing were carefully collected from the database of the national CJD surveillance program and analyzed using the SPSS 11.5 statistical software program. Since 2006, 69 patients were diagnosed with genetic prion diseases and as having 15 different mutations. The median age of the 69 patients at disease onset was 53.5 years, varying from 19 to 80 years. The majority of patients displaying clinical symptoms were in the 50-59 years of age. FFI, T188K gCJD and E200K were the three most common subtypes. The disease appeared in the family histories of 43.48% of the patients. The clinical manifestations varied considerably among the various diseases. Patients who carried mutations in the N-terminus displayed a younger age of onset, were CSF 14-3-3 negative, had a family history of the condition, and experienced a longer duration of the condition. The clinical courses of T188K were significantly shorter than those of FFI and E200K gCJD, while the symptoms in the FFI group appeared at a younger age and for a longer duration. Moreover, the time intervals between the initial neurologist visit to the final diagnosis were similar among patients with FFI, T188K gCJD, E200K gCJD and other diseases. The features of Chinese genetic prion diseases are different from those seen in Europe and other Asian countries.

The effects of increasing yield and quality of virus-free chewing cane seedlings and their physiological and molecular basis were studied in this study. Results showed that compared with infected seedlings (the control), the yield of chewing cane stems grown from virus-free seedlings increased by 21.81–29.93%, stem length increased by 28.66–34.49 cm, internode length increased by 2.16–2.68 cm, the single stem weight increased by 20.10–27.68%, the reducing sugar increased by 0.91–1.15% (absolute value), and sucrose increased by − 0.06–1.33% (absolute value). The decrease in sucrose content did not reach significant level, but all other parameters were reached significant level. The chlorophyll content, photosynthetic parameters such as stomatal conductance (Gs), net photosynthetic rate (Pn) and transpiration rate (Tr), the activity of photosynthetic key enzymes ribulose-1,5-bisphosphate carboxylase (Rubisco) and phosphoenolpyruvate carboxylase (PEPC), and gene ( pepc , rbcS, and rbcL ) expression levels were all greater in virus-free seedlings than infected seedlings. The content of superoxide anion (O 2 − ) and malondialdehyde (MDA) in virus-free seedlings was lower than infected seedlings at the main growth stage. With increased development, the activities of the antioxidant enzymes superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT) were gradually higher in virus-free seedlings than infected seedlings. Our results indicate that virus-free seedlings may improve photosynthesis efficiency and promote photosynthesis by increasing chlorophyll content, photosynthetic key enzyme activity, and the gene expression levels in leaves. By increasing the activity of antioxidant enzymes, reducing the degree of membrane lipid peroxidation, and improving the stress resistance of chewing cane, the virus-free chewing cane seedlings increased yield and quality. Our findings provide a scientific and theoretical basis for the promotion and application of virus-free chewing cane seedlings.

Drilling and coring, as effective ways to obtain lunar regolith along the longitudinal direction, are widely applied in the lunar sampling field. Conventionally, modeling of drill-soil interaction was divided into soil cutting and screw conveyance processes, ignoring the differences in soil mechanical properties between them. To improve the modeling accuracy, a hypothesis that divides the drill-soil interaction into four parts: cuttings screw conveyance, cuttings extruding, cuttings bulldozing, and in situ simulant cutting, is proposed to establish a novel model based on the passive earth pressure theory. An iterative numerical calculation method is developed to predict the drilling loads. A drilling and coring testbed is developed to conduct experimental tests. Drilling experiments indicate that the drilling loads calculated by the proposed model match well the experimental results. The proposed research provides the instructions to adopt a suitable drilling strategy to match the rotary and penetrating motions, to increase the safety and reliability of drilling control in lunar sampling missions.

Background Mesenchymal stem cells (MSCs) have potent immunomodulatory effects on multiple immune cells and have great potential in treating immune disorders. Induced pluripotent stem cells (iPSCs) serve as an unlimited and noninvasive source of MSCs, and iPSC-MSCs have been reported to have more advantages and exhibit immunomodulation on T lymphocytes and natural killer cells. However, the effects of iPSC-MSCs on dendritic cells (DCs) are unclear. The aim of this study is to investigate the effects of iPSC-MSCs on the differentiation, maturation, and function of DCs. Methods Human monocyte-derived DCs were induced and cultured in the presence or absence of iPSC-MSCs. Flow cytometry was used to analyze the phenotype and functions of DCs, and enzyme-linked immunosorbent assay (ELISA) was used to study cytokine production. Results In this study, we successfully induced MSCs from different clones of human iPSCs. iPSC-MSCs exhibited a higher proliferation rate with less cell senescence than BM-MSCs. iPSC-MSCs inhibited the differentiation of human monocyte-derived DCs by both producing interleukin (IL)-10 and direct cell contact. Furthermore, iPSC-MSCs did not affect immature DCs to become mature DCs, but modulated their functional properties by increasing their phagocytic ability and inhibiting their ability to stimulate proliferation of lymphocytes. More importantly, iPSC-MSCs induced the generation of IL-10-producing regulatory DCs in the process of maturation, which was mostly mediated by a cell-cell contact mechanism. Conclusions Our results indicate an important role for iPSC-MSCs in the modulation of DC differentiation and function, supporting the clinical application of iPSC-MSCs in DC-mediated immune diseases.

In this work, the degradation in luminous characteristics of red, green, and blue (RGB) micro-LEDs (10 µm × 10 µm) under electrical stress at 360 K has been investigated. After 280 h of aging, the AlGaInP-based red micro-LEDs exhibit a 31.7% reduction in maximum external quantum efficiency, which is significantly greater than the reductions observed in InGaN-based green and blue micro-LEDs. Specifically, the peak wavelength redshift by 0.6 nm, and blueshift 1.0 nm, and 0.5 nm for RGB micro-LEDs, respectively. The color purity of green and blue micro-LEDs decreases by 3.6% and 0.7%, respectively, resulting in a 7% reduction in color gamut.

Anthracnose is the most devastating disease affecting persimmon (Diospyros kaki Thunb.) cultivars in China, and is caused by the pathogen recently identified as Colletotrichum horii. In this study, the symptoms of anthracnose in persimmon fruits and trees in China, and the morphological characteristics of C. horii, were observed and recorded. Thirty simple sequence repeat (SSR) markers for C. horii were developed from the whole genome of the closely related species C. gloeosporioides, which is available from the GenBank database. After screening 30 combinations of primer pairs, six SSR markers were selected to amplify the genomic DNA of 23 isolates, to assess the degree of polymorphism and the reproducibility of the SSR markers. A total of 164 discernible bands were obtained when visualizing the amplicons by electrophoresis, 156 of which showed polymorphism. A dendrogram was constructed with FreeTree software (ver. 0.9.1.50) and the similarity coefficients ranged from 0.58–0.98. The result indicated there was genetic diversity in the C. horii population in China. There was an obvious correlation between the cluster groups and the sites from which the samples were isolated. The results of this study will facilitate a more detailed understanding of the population structure of C. horii in China.

As the world’s population is aging and there is a shortage of sufficient caring manpower, the development of intelligent care robots is a feasible solution. At present, plenty of care robots have been developed, but humanized care robots that can suitably respond to the individual behaviors of elderly people, such as pose, expression, gaze, and speech are generally lacking. To achieve the interaction, the main objectives of this study are: (1) conducting a literature review and analyzing the status quo on the following four core tasks of image and speech recognition technology: human pose recognition, human facial expression recognition, eye gazing recognition, and Chinese speech recognition; (2) proposing improvement strategies for these tasks based on the results of the literature review. The results of the study on these improvement strategies will provide the basis for using human facial expression robots in elderly care.