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UAV-based wireless powered communication network is a promising method of power supply for battery-free IoT devices, but the limited wireless transmission capability of the UAV constrains the coverage area and transmission throughput. This paper aims to address this issue by exploring intelligent reflecting surfaces with optimized configurations, including the number of reflective elements, transmission power, and the UAV’s altitude. The scheme design is challenging because such a throughput maximization problem is essentially a non-convex optimization problem due to the random wireless channel state and the unknown probability distribution of the objective function. By sequentially applying alternating optimization, successive convex approximation, penalty function, and difference-convex optimization, the schemes proposed in this paper can transform the original non-convex optimization problem into a convex one. Extensive evaluation proves the efficacy of the proposed scheme. The paper further compares two settings of the intelligent reflecting surface, namely dynamic phase shift and static phase shift, and provides their performance gap.

Wenzhou has improved its environmental quality because of comprehensive environmental remediation; nevertheless, the semen quality of infertile males remains unclear. This study determined whether better environmental quality improved semen quality in this region. We recorded semen quality data from 22 962 infertile males from January 2014 to November 2019 at the Center for Reproductive Health of The First Affiliated Hospital of Wenzhou Medical University (Wenzhou, China). Patients were predominantly 30–35 years old (33.1%) and workers (82.0%), with high school education or lower (77.6%); more than a half of the patients (52.6%) were Wenzhou household registration; and most patients (77.5%) had abnormal semen quality. Patients who were older than 40 years and workers, and those with Wenzhou household registration, had significantly worse semen quality (all P < 0.05). From 2014 to 2019, progressive sperm motility, total sperm motility, and semen volume showed increasing linear trends in all patients (P = 0.021, 0.030, and 0.005, respectively), yet normal sperm morphology showed a linearly decreasing trend (P = 0.046). Sensitivity analyses for subgroups yielded similar results. In conclusion, the improvement of environmental quality and better function of the accessory glands are associated with progressive sperm motility, total sperm motility, and semen volume. Normal sperm morphology is influenced by occupational exposures and personal lifestyle and does not improve with environmental quality.

Abstract MicroRNAs (miRNAs) exert critical effects in spinal cord injury (SCI). The miR‐33‐5p level is found to be lower in rats with SCI compared with that in control (untreated) and sham‐operated (laminectomy but no contusion) rats. Therefore, we investigated the biological functions of miR‐33‐5p and related mechanisms in SCI pathogenesis and development. An in vivo SCI model and a lipopolysaccharide (LPS)‐induced cell model of SCI were established. A downregulated level of miR‐33‐5p in experimental SCI and in LPS‐treated PC12 cells was revealed by reverse transcriptase‐quantitative polymerase chain reaction (RT‐qPCR). MiR‐33‐5p upregulation alleviated the leakage of the blood–spinal cord barrier (BSCB) induced by SCI and improved the neurological functions of SCI rats, as evidenced by the Basso, Beattie, and Bresnahan (BBB) scores and Evans blue staining. The regulatory relationship between miR‐33‐5p and Rps6kb1 was verified by luciferase reporter assays, which demonstrated that miR‐33‐5p bound to the Rps6kb1 3′UTR. Moreover, as MTT assays and flow cytometry showed, the suppressive effects of miR‐33‐5p upregulation on cell apoptosis were attenuated by Rps6kb1 upregulation. In conclusion, miR‐33‐5p ameliorates SCI in rats and inhibits the LPS‐induced apoptosis of PC12 cells.

Abstract Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has caused a global pandemic. Antibody resistance dampens neutralizing antibody therapy and threatens current global Coronavirus (COVID-19) vaccine campaigns. In addition to the emergence of resistant SARS-CoV-2 variants, little is known about how SARS-CoV-2 evades antibodies. Here, we report a novel mechanism of extracellular vesicle (EV)-mediated cell-to-cell transmission of SARS-CoV-2, which facilitates SARS-CoV-2 to escape from neutralizing antibodies. These EVs, initially observed in SARS-CoV-2 envelope protein-expressing cells, are secreted by various SARS-CoV-2-infected cells, including Vero E6, Calu-3, and HPAEpiC cells, undergoing infection-induced pyroptosis. Various SARS-CoV-2-infected cells produce similar EVs characterized by extra-large sizes (1.6–9.5 μm in diameter, average diameter > 4.2 μm) much larger than previously reported virus-generated vesicles. Transmission electron microscopy analysis and plaque assay reveal that these SARS-CoV-2-induced EVs contain large amounts of live virus particles. In particular, the vesicle-cloaked SARS-CoV-2 virus is resistant to neutralizing antibodies and able to reinfect naïve cells independent of the reported receptors and cofactors. Consistently, the constructed 3D images show that intact EVs could be taken up by recipient cells directly, supporting vesicle-mediated cell-to-cell transmission of SARS-CoV-2. Our findings reveal a novel mechanism of receptor-independent SARS-CoV-2 infection via cell-to-cell transmission, provide new insights into antibody resistance of SARS-CoV-2 and suggest potential targets for future antiviral therapeutics.

Abstract Background Hepatocellular carcinoma (HCC) generally arises from a background of liver cirrhosis (LC). Patients with cirrhosis and suspected HCC are recommended to undergo serum biomarker tests and imaging diagnostic evaluation. However, the performance of routine diagnostic methods in detecting early HCC remains unpromising. Methods Here, we conducted a large-scale, multicenter study of 1675 participants including 490 healthy controls, 577 LC patients, and 608 HCC patients from nine clinical centers across nine provinces of China, profiled gene mutation signatures of cell-free DNA (cfDNA) using Circulating Single-Molecule Amplification and Resequencing Technology (cSMART) through detecting 931 mutation sites across 21 genes. Results An integrated diagnostic model called “Combined method” was developed by combining three mutation sites and three serum biomarkers. Combined method outperformed AFP in the diagnosis of HCC, especially early HCC, with sensitivities of 81.25% for all stages and 66.67% for early HCC, respectively. Importantly, the integrated model exhibited high accuracy in differentiating AFP-negative, AFP-L3-negative, and PIVKA-II-negative HCCs from LCs.

Stalk lodging seriously affects yield and quality of crops, and it can be caused by several factors, such as environments, developmental stages, and internal chemical components of plant stalks. Breeding of stalk lodging-resistant varieties is thus an important task for maize breeders. To better understand the genetic basis underlying stalk lodging resistance, several methods such as quantitative trait locus (QTL) mapping and genome-wide association study (GWAS) have been used to mine potential gene resources. Based on different types of genetic populations and mapping methods, many significant loci associated with stalk lodging resistance have been identified so far. However, few work has been performed to compare and integrate these reported genetic loci. In this study, we first collected hundreds of QTLs and quantitative trait nucleotides (QTNs) related to stalk lodging traits in maize. Then we mapped and integrated the QTLs and QTNs in maize genome to identify overlapped hotspot regions. Based on the genomic confidence intervals harboring these overlapped hotspot regions, we predicted candidate genes related to stalk lodging traits. Meanwhile, we mapped reported genes to these hotspot regions. Finally, we constructed molecular regulatory networks underlying stalk lodging resistance in maize. Collectively, this study provides not only useful genetic loci for deeply exploring molecular mechanisms of stalk lodging resistance traits, but also potential candidate genes and targeted strategies for improving stalk lodging resistance to increase crop yields in future.

Currently,due to the wide application of multi-tenancy,containerization,virtualization and power over-subscription in data centers,the possibility of power attack is becoming increasingly higher.The main means of power attack is to run malicious codes to increase the power consumption of servers,storage device and network equipment to exceed the power limit of a distribution system.And it causes server failure or circuit breaker trip,or even the interruption of the power supply system of the data centers.In order to reduce the risk of power attack on data center,this paper proposes a power capping method of performance equivalence configuration(PCPEC).This method takes advantage of the difference of power consumption in different configurations of virtual machines to implement the equivalent replacement of virtual machine configuration.Experiment result shows that PCPEC can reduce the dynamic power consumption of the server by 22.2%~29.6%,and the performance of most virtual machines increases by 2.12% after the replacement of resource configuration,thus effectively reducing the impact of power attack on the data center.

Offshore wind forms (OWF), as frontier fields of new energy, are developing rapidly. However, the potential impacts of large-scale development of OWF on marine ecology remain unclear. To assess the effects of construction and operation of OWF on fishery resource, surveys were conducted in the Guishan OWF, 2021. The community structure, dominant species, species replacement ratio, resource density and spatial distribution of fishery resource both in construction, operation and surrounding areas were analyzed before and after construction of the OWF. The results showed that 84, 88, 105 and 99 species mainly including fish and crustaceans were identified in July, August, September and December, respectively. The species replacement ratios were 41.0%~93.4% between any two surveys. The Shannon-Wiener index and richness index in December were the maximum values; the highest Pielou index was in July. Compared with the baseline, the construction of OWF changed the structure of community and dominant species, decreased the fishery biodiversity and resource density. There is an artificial reef effect in the pile foundations of OWF. This study will provide the basic data and decision guidance for the long-term effects of construction and operation of OWF on fishery resource.

Diabetic retinopathy(DR)is one of the many complications of diabetes and one of the major causes of blindness in middle-aged and elderly people in the world. Early detection and treatment can effectively reduce the blindness rate. In recent years, the application of artificial intelligence(AI)in ophthalmology has been expanding, and its research in DR screening and diagnosis has become a new hotspot. This paper aims to summarize the research progress of AI in the field of DR screening and diagnosis in recent years, raise questions, and set a course for the future. Additional information related to the further application and promotion of AI in this field is also provided.

Coal resources are non-renewable one-time energy. With the increase in mining depth, thermal energy is released with the exploitation of deep coal resources. It is renewable and clean, unaffected by environmental factors, and is an important part of geothermal resources. The Chinese government attaches great importance to and encourages the development and utilization of clean energy. Therefore, this paper summarizes the development potential of geothermal resources in deep mines and the current situation of geotherm and coal mining, discusses the necessity and feasibility of geothermal development in deep mines, innovates a collaborative mining of geothermal energy and coal resources, and expounds the scientific and technical problems of the coordinated development of geothermal and coal resources in mines. The scientific problems primarily include the distribution characteristics and the supply law of geothermal sources in deep mines, the law of energy conduction and evolution in stopes, and the heat and mass transfer mechanism of low-grade geothermal energy. The technical problems mainly include the optimization method of the system for the coordinated development of geothermal and coal resources in deep mines, the method for the coordinated development of geothermal and coal resources in deep mines, etc. Focusing on the theme of the development of rock heat and hydrothermal resources in deep mines and considering the post-mining space and production system, this paper introduces four heat recovery methods: buried pipe heat recovery method in the backfilled stopes, water storage and heat recovery method in the goaf, heat recovery method in the closed fracture and caving zones, and in-situ drilling for the heat recovery method in deep aquifers. Keys and difficulties of this paper include the detection and evaluation of geothermal energy in deep mines, heat-absorbing functional materials of coal-based solid waste in deep and large spaces, the characteristics and controlling methods of the rock stratum movement in a multi-field environment in mine stopes, efficient transmission and stepped utilization system of low-grade heat energy, and the intelligent monitoring of geothermal energy and coal collaborative mining system. The results of this paper will provide technical support for the collaborative mining of geothermal energy and coal resources in deep mines in China, as well as provide a theoretical and practical reference for the development of a deep mine resources system in China and promote the construction of green mines and multi-economic development of deep mines in China.

Lake Qinghai is an ancient brackish water lake in which several endemic diatom species have been discovered. In this study, a species of Diatoma is observed under light and scanning electron microscopy and described as new, Diatoma sinensis sp. nov. The living cells of D. sinensis always lie in girdle view due to the cell depth being much larger than valve width (3.3–8.8 vs. 2.0–3.0 μm). The valves of D. sinensis are characterized by their narrow, linear-lanceolate outline, with capitate to subcapitate apices, the presence of two rimoportulae, one at each apex, embedded in the last rib or located among striae and a 4:2 configuration of girdle bands in normal vegetative cells, with four bands assigned to the epivalve and two to the hypovalve. The new taxon is compared with similar species from the genera Diatoma and Distrionella.

Objective To explore the influencing factors of long⁃term prognosis of patients with spontaneous cerebellar hemorrhage (SCH) after surgery. Methods Total 121 patients with SCH admitted to the Second Affiliated Hospital of Air Force Military Medical University from January 2012 to September 2019 were included. The prognosis was assessed by the modified Rankin Scale (mRS) 12 months after surgery, and the risk factors related to dismal prognosis were screened by univariate and multivariate Logistic regression analysis. Results The age (P=0.001), proportion of Glasgow Coma Scale (GCS) score≤8 (P=0.000), activated partial thromboplastin time (P=0.003), random blood glucose level (P=0.044) and ventilator assisted ventilation ratio (P=0.015) of patients with poor prognosis (mRS score 4-6, n=79) were higher than those of patients with good prognosis (mRS score 0-3, n=42), while platelet count was lower than those of patients with good prognosis (P=0.017). There was significant difference in surgery modes between 2 groups (P=0.001). Logistic regression analysis showed that older age (OR=1.090, 95%CI: 1.032-1.151; P=0.002), high serum D⁃dimer level (OR=1.339, 95%CI: 1.034-1.735; P=0.027), craniotomy hematoma removal (OR=4.949, 95%CI: 1.310-18.691; P=0.018) and hematoma puncture drainage (OR=6.789, 95%CI: 1.249-36.912; P=0.027) were the main risk factors for long⁃term dismal prognosis after surgery for SCH. Conclusions Older age, high serum D⁃dimer level and surgery modes are the risk factors for long⁃term dismal prognosis after surgery for SCH.

Background The correct reference range for maternal thyroid function during pregnancy is essential for making an accurate diagnosis of thyroid disease and delivering proper interventions in pregnant women. But there is still no universal standard for this in women with a twin pregnancy. Objective To determine a rational reference range for maternal thyroid function during twin pregnancies. Methods Healthy pregnant women who underwent antenatal examination in Obstetric Clinic, Beijing Friendship Hospital, Capital Medical University from January 2009 to September 2019 were retrospectively selected, including 352 with a twin pregnancy (twin group) , and 988 with a singleton pregnancy (singleton group) . Clinical and laboratory data were collected. The lower and upper limits for determining normal maternal thyroid function during twin pregnancies were the 2.5 (P2.5) and 97.5 (P97.5) percentiles of TSH and FT4. Clinical hyperthyroidism was defined as TSHP97.5 (total FT4) . Clinical hypothyroidism was defined as TSH>P97.5 (total TSH) and FT4P97.5 and P2.5≤FT4≤P97.5. Low T4 syndrome was diagnosed by P2.5 (total TSH) ≤TSH≤P97.5 (total TSH) and FT4

AIM: To evaluate the efficacy and safety of full-thickness sutures combined with intracameral air injection (FTS-AI) versus pre-Descemet's membrane sutures combined with intracameral air injection (PDS-AI) in the management of acute corneal hydrops in keratoconus. METHODS: The research included 8 patients (8 eyes) suffering from acute corneal hydrops caused by keratoconus. Four patients were randomly assigned to FTS-AI. And the other four were randomly assigned to PDS-AI. Corneal oedema, visual acuity, corneal thickness were assessed during follow-up. RESULTS: The demographics, preoperative duration of symptoms and severity of corneal hydrops between the two groups were not significantly different. The mean corneal oedema resolution time after FTS-AI and PDS-AI were 11±1.15 and 15±1.41d, respectively (P=0.005). The maximum corneal thickness of the scarred region decreased in both groups at one week postoperatively (P

AIM: To assess the reproducibility of macular perfusion parameters in non-proliferative diabetic retinopathy (NPDR) patients measured by different examiners and two different sweep modes of optical coherence tomography angiography (OCTA). METHODS: Ninety-eight (98 eyes) patients with NPDR were included in this study. All participates were performed three times using Cirrus OCTA with Angiography 3×3 mm2 and 6×6 mm2 sweep mode by two examiners. The macular foveal avascular zone (FAZ) and vessel density (VD) in the superficial retinal layer (SRL) were measured. The reproducibility of the measurements was evaluated with intraclass correlation coefficients (ICC) and coefficient of variation (CoV). RESULTS: The intra-mode ICCs of Angiography 3×3 mm2 and 6×6 mm2 sweep mode were 0.957 to 0.959 and 0.964 to 0.977, respectively; and the inter-mode ICCs were 0.962 to 0.970. The intra-examiner ICCs of macular perfusion parameters were >0.950; and the inter-examiner ICCs were 0.928 to 0.969. All CoVs were