At the end of the Palaeozoic Era, most species on Earth disappeared completely and the global sedimentary environment and biology changed dramatically. The Permian–Triassic boundary (PTB) was studied in three sections of the middle Upper Yangtze Platform, SW China: Xingwen well and Zhijin and Shangsi sections. These sections are characterized by carbonate-platform, toe-of-slope and basin facies, respectively. Detailed analysis of 100 closely spaced thin-sections revealed a total of 24 microfacies and 11 microfacies associations based on the dominant carbonate grain size and the skeletal material (type and proportion). Six bioassemblages are documented for the first time, spanning c. 1 Ma across the boundary succession, including normal, resurrected and miniaturized Permian biota, and cyanobacteria-dominated, survival post-crisis and neonatal Triassic biota. The Xingwen well indicated sedimentary evolution from a rimmed carbonate platform to a homoclinal carbonate ramp, as well as a sharp fall in sea level just prior to the PTB in the study area. The Zhijin section revealed a slope setting, in which toe-of-slope and middle-ramp microfacies are identified. The Shangsi section showed a complete evolution of basin and outer-ramp microfacies and bioassemblages. Fossil evidence showed that the Permian biota (trilobites, gastropods and phylloid algae) occurred in the uppermost Changhsingian stage and was overlain by biomicrites with miniaturized ostracods (< 0.2 mm in size). This indicated that the major extinction horizon is located up to 14 cm below the PTB, which lies in the middle–lower segments of the miniaturized ostracod layer.

Due to the lack of research between the inner layers in the structure of colonic mucous and the metabolism of fatty acid in the constipation model, we aim to determine the changes in the mucous phenotype of the colonic glycocalyx and the microbial community structure following treatment with Rhubarb extract in our research. The constipation and treatment models are generated using adult male C57BL/6N mice. We perform light microscopy and transmission electron microscopy (TEM) to detect a Muc2-rich inner mucus layer attached to mice colon under different conditions. In addition, 16S rDNA sequencing is performed to examine the intestinal flora. According to TEM images, we demonstrate that Rhubarb can promote mucin secretion and find direct evidence of dendritic structure-linked mucus structures with its assembly into a lamellar network in a pore size distribution in the isolated colon section. Moreover, the diversity of intestinal flora has noticeable changes in constipated mice. The present study characterizes a dendritic structure and persistent cross-links have significant changes accompanied by the alteration of intestinal flora in feces in models of constipation and pretreatment with Rhubarb extract.

The fall armyworm (Spodoptera frugiperda), a destructive pest that originated in South and North America, spread to China in early 2019. Controlling this invasive pest requires an understanding of its population structure and migration patterns, yet the invasion genetics of Chinese S. frugiperda is not clear. Here, using the mitochondrial cytochrome oxidase subunit I (COI) gene, triose phosphate isomerase (Tpi) gene and eight microsatellite loci, we investigated genetic structure and genetic diversity of 16 S. frugiperda populations in China. The Tpi locus identified most S. frugiperda populations as the corn-strains, and a few were heterozygous strains. The microsatellite loci revealed that the genetic diversity of this pest in China was lower than that in South America. Furthermore, we found moderate differentiation among the populations, distinct genetic structures between adjacent populations and abundant genetic resources in the S. frugiperda populations from China sampled across 2 years. The survival rate of S. frugiperda was significantly higher when it was fed on corn leaves than on rice leaves, and the larval stage mortality rate was the highest under both treatments. Our results showed that S. frugiperda probably invaded China via multiple independent introductions and careful pesticide control, continuous monitoring and further studies will be needed to minimize its potential future outbreak.

Nicotine 2,6-dihydroxybenzoate is a nicotine salt that can be used as the nicotine source in tobacco products. X-ray powder diffraction data, unit-cell parameters, and space group for nicotine 2,6-dihydroxybenzoate, C10H15N2⋅C7H5O4, are reported [a = 7.726(8) Å, b = 11.724(3) Å, c = 9.437(1) Å, α = 90°, β = 109.081(3)°, γ = 90°, unit-cell volume V = 802.902 Å3, Z = 2, ρcal = 1.309 g cm−3, and space group P21] at room temperature. All measured lines were indexed and were consistent with the P21 space group.

Routine Corona Virus Disease 2019 (COVID-19) screening found one asymptomatic COVID-19 patient. An emergency sampling team was organized consisting of 1200 healthcare workers, and a total of 3.2228 million COVID-19 samples had been collected and detected. This study summarizes the on-site management experience in large-scale COVID-19 nucleic acid testing from various aspects: staff preparation, materials preparation, site layout, logistics support, and information system support. Suggestions are put forward for the deficiencies and parts needing improvement. Such as some sampling sites were not properly chosen, different areas were unclearly marked off from each other, and some site moving lines were confounding. How to communicate with the street service workers who had little professional knowledge on the epidemic spread or the working principles of the workflow and site layout. And the way to resolve conflicts on site.

This study examined the influences of coated folic acid (CFA) and coated riboflavin (CRF) on bull performance, nutrients digestion and ruminal fermentation. Forty-eight Angus bulls based on a randomised block and 2 × 2 factorial design were assigned to four treatments. The CFA of 0 or 6 mg of folic acid/kg DM was supplemented in diets with CRF 0 or 60 mg riboflavin (RF)/kg DM. Supplementation of CRF in diets with CFA had greater increase in daily weight gain and feed efficiency than in diets without CFA. Supplementation with CFA or CRF enhanced digestibility of DM, organic matter, crude protein, neutral-detergent fibre and non-fibre carbohydrate. Ruminal pH and ammonia N content decreased and total volatile fatty acids concentration and acetate to propionate ratio elevated for CFA or CRF addition. Supplement of CFA or CRF increased the activities of fibrolytic enzymes and the numbers of total bacteria, protozoa, fungi, dominant fibrolytic bacteria and Prevotella ruminicola. The activities of α-amylase, protease and pectinase and the numbers of Butyrivibrio fibrisolvens and Ruminobacter amylophilus were increased by CFA but were unaffected by CRF. Blood concentration of folate elevated and homocysteine decreased for CFA addition. The CRF supplementation elevated blood concentrations of folate and RF. These findings suggested that CFA or CRF inclusion had facilitating effects on performance and ruminal fermentation, and combined addition of CFA and CRF had greater increase in performance than CFA or CRF addition alone in bulls.

The wheat aphid Sitobion miscanthi (CWA) is an important harmful pest in wheat fields. Insecticide application is the main method to effectively control wheat aphids. However, CWA has developed resistance to some insecticides due to its extensive application, and understanding resistance mechanisms is crucial for the management of CWA. In our study, a new P450 gene, CYP4CJ6, was identified from CWA and showed a positive response to imidacloprid and thiamethoxam. Transcription of CYP4CJ6 was significantly induced by both imidacloprid and thiamethoxam, and overexpression of CYP4CJ6 in the imidacloprid-resistant strain was also observed. The sensitivity of CWA to these two insecticides was increased after the knockdown of CYP4CJ6. These results indicated that CYP4CJ6 could be associated with CWA resistance to imidacloprid and thiamethoxam. Subsequently, the posttranscriptional regulatory mechanism was assessed, and miR-316 was confirmed to participate in the posttranscriptional regulation of CYP4CJ6. These results are crucial for clarifying the roles of P450 in the resistance of CWA to insecticides.

The complex sea ice conditions in Arctic waters has different impacts on the legs of the Arctic passage, and ships of specific ice classes face different navigation risks. Therefore, the quantitative analysis of the navigation risks faced in different legs has important practical significance. Based on the POLARIS introduced by IMO, the sea ice condition data from 2011 to 2020 was used to quantify the navigation risk of the Arctic Northeast passage. The risk index outcome (RIO) of the Arctic Northeast Passage were calculated. The navigable windows of the route for ice class 1A ships sailing independently under different sea ice conditions in the last decade were determined, with a navigable period of 91 days under normal sea ice conditions, approximately 175 days under light sea ice conditions and only week 40 close to navigation under severe sea ice conditions. The three critical waters affecting the safety of ships were identified. Combined with the navigable windows and critical waters, recommendations on ship's navigation and manipulation and recommendations for stakeholders were given. The method and results provided reference and support for the assessment of the navigation risk of ships in the Northeast Passage and safety navigation and operations of ships, and satisfied the needs of relevant countries and enterprises to rationally arrange shipment dates and sailing plans based on different ice classes of ships.

When conducting accident analysis, the assessment of risk is one of the important links. Moreover, with regards to crew training, risk cognition is also an important training subject. However, most of the existing researches only rely on a single or a few data sources. It is necessary to fuse the collected multi-source data to obtain a more comprehensive risk evaluation model. There are few studies on the three-dimensional (3D) multi-modal data-fusion-based trajectory risk cognition. In this paper, a fuzzy logic-based trajectory risk cognition method is proposed based on multi-model spatial data fusion and accident data mining. First, the necessity of multi-model spatial data fusion is analysed and a data-fusion-based scene map is constructed. Second, a risk cognition model fused by multiple factors, multi-dimensional spatial calculations as well as data mining results is proposed, including a novel ship boundary calculation approach and newly constructed factors. Finally, a radar chart is used to illustrate the risk, and a risk cognition system is developed. Experiment results confirm the effectiveness of the method. It can be applied to train human operators of unmanned ship systems.

Coronavirus disease 2019 (COVID-19) is a serious respiratory disease mediated by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. The worldwide spread of COVID-19 has caused millions of confirmed cases and morbidity, and the crisis has greatly affected global economy and daily life and changed our attitudes towards life. The reproductive system, as a potential target, is at a high risk of SARS-CoV-2 infection, and females are more vulnerable to viral infection compared with males. Therefore, female fertility and associated reproductive health care in the COVID-19 era need more attention. This review summarises the mechanism of SARS-CoV-2 infection in the female reproductive system and discusses the impact of the COVID-19 crisis on female fertility. Studies have proven that COVID-19 might affect female fertility and interfere with assisted reproductive technology procedures. The side effects of vaccines against the virus on ovarian reserve and pregnancy have not yet been well investigated. In the future, the female fertility after SARS-CoV-2 infection and vaccination needs more attention because of the uncertainty of COVID-19.

Several candidates of universal influenza vaccine (UIV) have entered phase III clinical trials, which are expected to improve the willingness and coverage of the population substantially. The impact of UIV on the seasonal influenza epidemic in low influenza vaccination coverage regions like China remains unclear. We proposed a new compartmental model involving the transmission of different influenza subtypes to evaluate the effects of UIV. We calibrated the model by weekly surveillance data of influenza in Xi'an City, Shaanxi Province, China, during 2010/11–2018/19 influenza seasons. We calculated the percentage of averted infections under 2-month (September to October) and 6-month (September to the next February) vaccination patterns with varied UIV effectiveness and coverage in each influenza season, compared with no UIV scenario. A total of 195 766 influenza-like illness (ILI) cases were reported during the nine influenza seasons (2010/11–2018/19), of which the highest ILI cases were among age group 0–4 (59.60%) years old, followed by 5–14 (25.22%), 25–59 (8.19%), 15–24 (3.75%) and ⩾60 (3.37%) years old. The influenza-positive rate for all age groups among ILI cases was 17.51%, which is highest among 5–14 (23.75%) age group and followed by 25–59 (16.44%), 15–24 (16.42%), 0–4 (14.66%) and ⩾60 (13.98%) age groups, respectively. Our model showed that UIV might greatly avert influenza infections irrespective of subtypes in each influenza season. For example, in the 2018/19 influenza season, 2-month vaccination pattern with low UIV effectiveness (50%) and coverage (10%), and high UIV effectiveness (75%) and coverage (30%) could avert 41.6% (95% CI 27.8–55.4%) and 83.4% (80.9–85.9%) of influenza infections, respectively; 6-month vaccination pattern with low and high UIV effectiveness and coverage could avert 32.0% (15.9–48.2%) and 74.2% (69.7–78.7%) of influenza infections, respectively. It would need 11.4% (7.9–15.0%) of coverage to reduce half of the influenza infections for 2-month vaccination pattern with low UIV effectiveness and 8.5% (5.0–11.2%) of coverage with high UIV effectiveness, while it would need 15.5% (8.9–20.7%) of coverage for 6-month vaccination pattern with low UIV effectiveness and 11.2% (6.5–15.0%) of coverage with high UIV effectiveness. We conclude that UIV could significantly reduce the influenza infections even for low UIV effectiveness and coverage. The 2-month vaccination pattern could avert more influenza infections than the 6-month vaccination pattern irrespective of influenza subtype and UIV effectiveness and coverage.

Celestial navigation is an important means of maritime navigation; it can automatically achieve inertially referenced positioning and orientation after a long period of development. However, the impact of different accuracy of observations and the influence of nonstationary states, such as ship speed change and steering, are not taken into account in existing algorithms. To solve this problem, this paper proposes an adaptively robust maritime celestial navigation algorithm, in which each observation value is given an equivalent weight according to the robust estimation theory, and the dynamic balance between astronomical observation and prediction values of vessel motion is adjusted by applying the adaptive factor. With this system, compared with the frequently used least square method and extended Kalman filter algorithm, not only are the real-time and high-precision navigation parameters, such as position, course, and speed for the vessel, calculated simultaneously, but also the influence of abnormal observation and vessel motion status change could be well suppressed.

The Middle Miocene Climatic Optimum is known for abrupt events during the global cooling trend of the past 20 Ma. Its identification in the Tibetan Plateau can help explain the cause of the critical Middle Miocene climate transition in Central Asia. In this study, fine-grained mixed sediments widely distributed in the Miocene Qaidam Lake in the northern Tibetan Plateau were used as a sensitive indicator for palaeoclimate. Their geochemical characteristics were investigated, together with an analysis of 2600 m long successive gamma-ray logging data from the whole JS2 drillcore, to understand the mid-Miocene climate transition in the Tibetan Plateau. By comparing the gamma-ray curve of the mixed sediments with global temperature, the Middle Miocene Climatic Optimum event can be easily identified. Further, the detailed petrological features and geochemical data of lacustrine fine-grained mixed sediments from a 400 m drillcore show oxidizing, high-sedimentation rate and brackish-saline water conditions in a semi-arid climate during the Middle Miocene period, demonstrating a dryer climate in the Qaidam Basin than in the monsoon-sensitive regions in Central Asia. These fine-grained mixed sediments have recorded climate drying before 15.3 Ma that represents a climatic transition within the Middle Miocene Climatic Optimum; increasing carbonate-rich mixed sediments, decreasing algal limestone layers and decreasing lacustrine organic matter are indicators of this transition. Regional tectonic events include the retreat of the Paratethys from Central Asia at ∼15 Ma and the synchronous tectonic reorganization of the Altyn-Tagh fault system and the northeastern Tibetan Plateau. We find that global climate change is the primary factor affecting the overall characteristics and changes of the Neogene climate in the Qaidam Basin, including the occurrence of the Middle Miocene Climatic Optimum and the cooling and drying tendency, while the regional events are a secondary factor.

Different from developed countries, there is a paucity of research examining how the Dietary Approaches to Stop Hypertension (DASH) and Mediterranean diets relate to lipids in less-developed ethnic minority regions (LEMR). A total of 83 081 participants from seven ethnic groups were retrieved from the baseline data of the China Multi-Ethnic Cohort study, which was conducted in less-developed Southwest China between May 2018 and September 2019. Multivariable linear regression models were then used to examine the associations of the DASH and alternative Mediterranean diet (AMED) scores, assessed by modified DASH score and AMED, as well as their components with total cholesterol (TC), LDL-cholesterol, HDL-cholesterol, TAG and TC/HDL-cholesterol. The DASH scores were negatively associated with TC, HDL-cholesterol and TAG. Comparing the highest quintiles with the lowest DASH scores, TC decreased 0·0708 (95 % CI −0·0923, −0·0493) mmol/l, HDL-cholesterol decreased 0·0380 (95 % CI −0·0462, −0·0299) mmol/l and TAG decreased 0·0668 (95 % CI −0·0994, −0·0341) mmol/l. The AMED scores were negatively associated with TC, LDL-cholesterol and HDL-cholesterol. Comparing the highest quintiles with the lowest AMED scores, TC decreased 0·0816 (95 % CI −0·1035, −0·0597) mmol/l, LDL-cholesterol decreased 0·0297 (95 % CI −0·0477, −0·0118) mmol/l and HDL-cholesterol decreased 0·0275 (95 % CI −0·0358, −0·0192) mmol/l. Although both the DASH diet and the Mediterranean diet were negatively associated with blood lipids, those associations showed different patterns in LEMR, particularly for TAG and HDL-cholesterol.

Masturbation is a common sexual practice in men, and saliva is often used as a lubricant during masturbation by men who have sex with men. However, the role of saliva use during masturbation in the transmission of chlamydia is still unclear. We developed population-level, susceptible-infected-susceptible compartmental models to explore the role of saliva use during masturbation on the transmission of chlamydia at multiple anatomical sites. In this study, we simulated both solo masturbation and mutual masturbation. Our baseline model did not include masturbation but included transmission routes (anal sex, oral-penile sex, rimming, kissing and sequential sexual practices) we have previously validated (model 1). We added masturbation to model 1 to develop the second model (model 2). We calibrated the model to five clinical datasets separately to assess the effects of masturbation on the prevalence of site-specific infection. The inclusion of masturbation (model 2) significantly worsened the ability of the models to replicate the prevalence of C. trachomatis. Using model 2 and the five data sets, we estimated that saliva use during masturbation was responsible for between 3.9% [95% confidence interval (CI) 2.0–6.8] and 6.2% (95% CI 3.8–10.5) of incident chlamydia cases at all sites. Our models suggest that saliva use during masturbation is unlikely to play a major role in chlamydia transmission between men, and even if it does have a role, about one in seven cases of urethral chlamydia might arise from masturbation.