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Parabadiella is considered the earliest trilobite representative in South China and was originally recovered from the mid-upper part of the Guojiaba Formation, in Liangshan section. Previous studies suggested that the earliest brachiopod co-occurred with the oldest trilobite, and the Parabadiella–Eoobolus association from the Xihaoping Member (Cambrian Series 2, Stage 3), in southern Shaanxi was considered the first trilobite–brachiopod assemblage zone in South China. Therein, brachiopods occur together with trilobites recovered in Well JS103 seemingly extending the First Appearance Datum deeply in the lower Cambrian at the central Yangtze Platform. Well JS103 is a shale gas exploration well that targets the lower Cambrian Jiulaodong Formation in southern Sichuan Basin. The uppermost fossiliferous layers are siliciclastic rocks nearly 10 metres thick. Here, two distinct trilobite zones are found, including the lower Parabadiella Zone and the upper Wutingaspis–Eoredlichia Zone. Additionally, the lowermost part of the Guojiaba Formation is poorly fossiliferous, and ranges from 200 to 250 metres in thickness. Thus, the discovery of the brachiopod–trilobite assemblage provides new insights into the biostratigraphy in Sichuan and is of great potentials for biostratigraphic correlation of the siliciclastic rocks in the western margin of the Yangtze Platform. [ABSTRACT FROM AUTHOR]

China's helium resource is highly dependent on overseas imports. Organic-rich and U/Th-rich shale reservoirs generally contain helium, and although the helium content is low, the total reserve is large. Therefore, the effective development and utilisation of shale-type helium resources is a realistic way to improve the security of helium resources in China. In this study, the generation mechanism, helium source and content, migration modes and pathways, controlling factors of enrichment, distribution pattern, and resource potential of the helium were analysed, using the Wufeng-Longmaxi shale in the Sichuan Basin and its periphery. Furthermore, countermeasures were proposed for shale-type helium exploration and development. The results show that the Wufeng-Longmaxi shale has a high content of U and Th and a good ability to generate helium. The helium is generated by a typical crustal source of helium and is characterised by self-generation, self-storage, and wide distribution. The helium resource potential is a product of its content and the resources of the associated natural gas. The continuous supply of helium and effective preservation are the main geological factors that control the enrichment of shale-type helium. The preliminary evaluation results show that the reserves of helium in proven shale gas reserves are 10.8×108 m3 in the Sichuan Basin and its periphery, where the extra-large helium fields are likely to be discovered. Additionally, 0.0912×108 m3 of helium was produced, along with the annual production of shale gas. To avoid the waste of helium and to improve the self-supply ability, it is suggested that research on the resource potential, enrichment mechanism, and distribution pattern of shale-type helium should be carried out as soon as possible, and helium extraction techniques for helium-bearing natural gas should be studied. [ABSTRACT FROM AUTHOR]

Rhizome Chuanxiong (RCX), the dried rhizomes of Ligusticum striatum DC., is a geoauthentic TCM herb distributed in Sichuan province of China that possesses efficacy in promoting blood circulation, removing blood stasis and alleviating pain. Rhizome Chuanxiong total alkaloids (RCXTAs) are one of the major characteristic constituents of RCX with the effects of antimigraine, neuroprotective, cardioprotective and other cardiovascular and cerebrovascular diseases. Over the past years, rapid development of technology has advanced some aspects of RCXTAs. The aim of this review is to illustrate the recent advances in the chemical analysis and biological activities of RCXTAs, and to highlight new challenges. [ABSTRACT FROM AUTHOR]

Since the development of indica hybrid rice in the 1970s, great success has been achieved in hybrid rice production in China and around the world. The utilization of inter-subspecific indica–japonica hybrid rice has always been considered due to its stronger heterosis characteristics. However, indica – japonica hybrids face a serious problem of sterility, which hinders the exploitation of their heterosis. In the past decades, the genetic basis of indica – japonica hybrid sterility has been well studied. It was found that in sterile indica – japonica hybrids, female sterility was mainly controlled by the S5 locus and male sterility by the Sa , Sb , Sc , Sd , and Se loci. In this study, we developed wide-compatible indica lines (WCILs) by pyramiding multiple neutral (n) alleles of the hybrid sterility loci. First, we identified Sn alleles of the loci in single-segment substitution lines (SSSLs) in the genetic background of indica Huajingxian 74 (HJX74). Then, the Sn alleles of S5 , Sb , Sc , Sd , and Se loci in SSSLs were pyramided in the HJX74 genetic background. The WCILs carrying Sn alleles at the S5 , Sb , Sc , Sd , and Se loci showed wide compatibility with indica and japonica rice varieties. Therefore, the WCILs will be used to develop inter-subspecific indica–japonica hybrid rice with normal fertility. [ABSTRACT FROM AUTHOR]

Many people die from cardiovascular diseases each year, and extreme temperatures are regarded as a risk factor for cardiovascular deaths. However, the relationship between temperature and cardiovascular deaths varies in different regions because of population density, demographic inequality, and economic situation, and the evidence in Ganzhou, China is limited and inconclusive. This study aimed to assess extreme temperature-related cardiovascular mortality and identify the potential vulnerable people. After controlling other meteorological measures, air pollution, seasonality, relative humidity, day of the week, and public holidays, we examined temperature-related cardiovascular mortality along 21 lag days by Poisson in Ganzhou, China. A J-shaped relationship was observed between mean temperature and cardiovascular mortality. Extremely low temperatures substantially increased the relative risks (RR) of cardiovascular mortality. The effect of cold temperature was delayed by 2–6 days and persisted for 4–10 days. However, the risk of cardiovascular mortality related to extremely high temperatures was not significant (p > 0.05). Subgroup analysis indicated that extremely low temperatures had a stronger association with cardiovascular mortality in people with cerebrovascular diseases (RR: 1.282, 95% confidence interval [CI]: 1.020–1.611), males (RR: 1.492, 95% CI: 1.175–1.896), married people (RR: 1.590, 95% CI: 1.224–2.064), and people above the age of 65 years (RR: 1.641, 95% CI: 1.106–2.434) than in people with ischemic heart disease, females, unmarried people, and the elderly (≥65 years old), respectively. The type of cardiovascular disease, sex, age, and marital status modified the effects of extremely low temperatures on the risk of cardiovascular mortality. These findings may help local governments to establish warning systems and precautionary measures to reduce temperature-related cardiovascular mortality. [ABSTRACT FROM AUTHOR]

• Long-ranging hypobradytelic cyanobacteria dominate the Maidiping microbial assemblage. • Obruchevella with distinct cross-partitioning is preserved with exceptional fidelity. • We propose two possible explanations for the morphological variation of Obruchevella. • Filament diameter is the key character in the taxonomy of Obruchevella. Phosphatization is known for its remarkably detailed preservation of cellular and subcellular microfossils through diagenetic phosphate replacement of the original organic materials. Thin-sections of the Ediacaran-Cambrian transition Maidiping Formation from borehole core Jinshi 103 from southern Sichuan Province, China, exhibit a newly discovered, diverse assemblage of helically coiled microfossils. The four genera recovered include three-dimensional preserved Obruchevella and fragments of cyanobacteria Siphonophycus and Oscillatoriopsis and coccoidal fossils Archaeophycus. The fossil assemblage was dominated by long-ranging hypobradytelic (exceptionally slow evolutionary rate) cyanobacteria. A large number of exquisitely preserved Obruchevella can be identified, including O. minor , O. parva , O. delicata , O. meishucunensis , and O. magna , which exhibit a variety of morphologies, ranging from tangled masses to well-developed helixes, from cocoons with thick mucilaginous sheaths to elongated spring-like forms. Preserved with exceptional fidelity, these Obruchevella species display distinct cross-partitioning and support affinities with modern helical cyanobacteria, such as Arthrospira or Spirulina. Based on traditional taxonomic parameters, such as filament diameter, helix diameter, and winding pattern, two possibilities for the morphological variety of the spiral rings of Obruchevella are proposed. Overall, the Maidiping fossil assemblage provides new paleontological data on the Ediacaran-Cambrian transition and opens an important window into the evolution of early ecosystems at the time of metazoan radiation. [ABSTRACT FROM AUTHOR]

The rattans of Spatholobus suberectus Dunn are a traditional Chinese medicine activating blood circulation and removing stasis. They have often been used for the traditional Chinese medicinal treatment of breast cancer in modern China. In this study, four novel isoflavanes (1–3 and 5) and four known analogues (4 and 6–8) were isolated from an ethanolic extract of the rattans of S. suberectus. Their structures were elucidated by extensive spectroscopic analyses and electronic circular dichroism studies. MCF-7 and MDA-MB-231 human breast cancer cell lines were used to evaluate the cytotoxic effects of the isolates. Interestingly, compounds 1 and 2 only inhibited the proliferation of MCF-7 cells, while compound 6 showed a selective cytotoxicity against MDA-MB-231 cells. However, compound 4 had significant cytotoxicity against both MCF-7 and MDA-MB-231 cell lines. [ABSTRACT FROM AUTHOR]

Leonurus japonicus Houtt. is a medicine food homology plant that is widely farmed in China. In traditional Chinese medicine, the aerial part of L. japonicus (Chinese motherwort) is named Yimucao and has medicinal uses. Yimucao in the seedling stage can be eaten as a wild vegetable and incorporated into one's everyday diet. The quality of Yimucao is often associated with its production origins, and the geographical authenticity of Yimucao is important for ensuring its clinical efficacy. A combined strategy based on the analysis of stable isotopes (δ 13C, δ 15N, δ 2H, and δ 18O), elemental content (%C and %N), and extracts (aqueous and ethanol extracts) was conducted to trace the geographical origin of Yimucao in China. Here, eight variables of 63 Yimucao samples collected from eight provinces were examined, and notable distinctions were observed on the provincial scale and regional scale (P < 0.05). Principal component analysis, orthogonal partial least square–discriminant analysis, and four machine learning methods (random forest, adaptive boosting, support vector machine, and neural network) were applied for geographical classification. We found that the random forest model was the most optimal classifier with a remarkable prediction accuracy reaching 98.4%. Among the eight differentiation markers analyzed, δ 15N, δ 18O, and δ 2H were the most potent indicators. The correlation analysis between eight variables and environmental factors indicated that latitude, sunshine duration, and relative humidity were responsible for the majority of the differences in the production areas. This study demonstrated that comprehensive analysis of stable isotopes and extracts assisted by machine learning algorithms is a powerful method for determining the geographical origins of Yimucao in China. [Display omitted] • The stable isotopes showed a significant advantage in origin traceability of Yimucao. • The random forest model achieved the most satisfactory classification effect in distinguishing the origin of Yimucao. • A geographical classification model for Yimucao based on a combination of stable isotopes and extracts was established. • Correlation among stable isotopes, extracts, and environmental factors of Yimucao was thoroughly analyzed. [ABSTRACT FROM AUTHOR]

To evaluate the effectiveness and safety of hypothermic perfusion in the phacoemulsification of hard nuclear cataract. Tertiary opthalmology center, China. Laboratory study and prospective randomized clinical trial. Rabbits and patients with hard nuclear cataract underwent phacoemulsification with perfusion temperatures at 4°C or 24°C. Anterior segment optical coherence tomography (AS-OCT), corneal endothelial cell count (ECC), and cornea sections were observed before the rabbits' operation and 1 day and 7 days postoperatively. AS-OCT, corneal ECC, and anterior chamber (AC) inflammation were observed before the patients' operation and 1 day, 7 days, and 30 days postoperatively. The study comprised 40 rabbits and 80 patients. In the animal models, the mean central corneal thickness (CCT) in the 4°C group (370.4 μm ± 45.5 [SD]) was thinner than in the 24°C group (496.7 ± 121.5 μm) 1 day postoperatively (P <.001). The mean AC inflammation reaction grade in the 4°C group (1.1 ± 0.9) was lower than in the 24°C group (2.2 ± 0.8) (P =.0333). In clinical trials, the mean CCT and incisional corneal thicknesses in the 4°C group (600.7 ± 51.8 μm and 859.2 ± 177.8 μm, respectively) were thinner than in the 24°C group (655.3 ± 85.0 μm and 955.9 ± 196.7 μm, respectively) (P <.001). The endothelial cell density (P =.036) and hexagonality (P =.001) were higher in the 4°C group. The mean AC inflammation reaction grade in the 4°C group (0.6 ± 0.6) was lower than in the 24°C group (1.3 ± 1.0) 1 day postoperatively (P =.004). Hypothermic perfusion in phacoemulsification of hard nuclear cataract is safe and it can effectively protect corneal endothelium, decrease corneal edema, and reduce AC inflammation in the early postoperative stage. [ABSTRACT FROM AUTHOR]

[Display omitted] • T-OAE changed the hydrological conditions during the sedimentary process of the Da'anzhai member. • OM accumulation controlled by relatively reducing environment and low salinity conditions. • T-OAE affects organic matter-associated pores development by promoting water column productivity. The Da'anzhai Member of the Lower Jurassic Ziliujing Formation of the Sichuan Basin is one of the most important targets for lacustrine shale oil exploration in China. Organic matter (OM) content is a critical factor when considering the exploration and production potential of lacustrine shale reservoirs. However, the complexity of the lacustrine paleoenvironment necessitates a fuller understanding of OM accumulation mechanisms. The Early Jurassic (∼183 Ma) Toarcian Oceanic Anoxic Event (T-OAE) occurred concurrently with the deposition of the Da'anzhai Member. However, the control of sedimentary differentiation triggered by the T-OAE on the formation of lacustrine shale oil reservoirs remains a matter of debate. In this study, we used total organic carbon (TOC) analysis, X-ray diffraction (XRD), major and trace element analyses, field emission scanning electron microscopy (FE-SEM), mercury intrusion capillary pressure (MIP) measurements, and nitrogen adsorption (NA) analysis to investigate the Da'anzhai Member in the Langzhong region of the Sichuan Basin. Our results demonstrate that the deposits of the Da'anzhai Member accumulated in a warm and humid oxygenated environment under freshwater to brackish salinities. OM accumulation in the Da'anzhai Member was largely controlled by redox and salinity conditions. The pore systems of the analyzed samples of the Da'anzhai Member were diverse but dominated by clay mineral-associated pores. The T-OAE appears to have modified the redox conditions and salinity of the lacustrine environment, in which sediment of the middle part of the Da'anzhai Member accumulated by influencing paleoclimate and hydrological conditions, resulting in the enrichment of OM in contemporaneous sediment. Furthermore, the onset of T-OAE affected the productivity of the water column, inducing changes in the kerogen type that favored the formation of organic pores. In summary, T-OAE influenced the exploration and production quality of lacustrine shale by engendering OM enrichment and organic pore formation. Our study provides new insights into the effects and influence of OAEs on the accumulation in lacustrine shale oil reservoirs. [ABSTRACT FROM AUTHOR]

Migraine is a prevalent, complex, painful, and disabling neurovascular disorder that places an enormous social and economic burden on patients. Rhizome Chuanxiong (RCX), the dried rhizomes of Ligusticum striatum DC., has been widely used in the clinic for the treatment of migraine for centuries in China. Total alkaloids (TAs) are considered to be important effective ingredients of L. striatum , especially for cardiovascular and cerebrovascular diseases. However, there has been no study published, to date, reporting the antimigraine effects of TAs from RCX (RCXTAs). Aim of the study: The present study was designed to evaluate the antimigraine effects of RCXTAs and explore the underlying mechanisms in an experimental migraine rat model. RCXTAs were prepared in accordance with our previous optimized preparation process. A nitroglycerin-induced migraine model in rats and a reserpine-induced migraine model in mice were established to investigate the effects of RCXTAs on monoamine neurotransmitters in brain tissue, including 5-hydroxytryptamine (5-HT) and its metabolite (5-HIAA). Migraine rats or mice were divided into six groups as follows: control; model; zolmitriptan (1.67 mg/kg); and low-, medium-, and high-dose RCXTAs (12.5, 25, and 50 mg/kg, respectively). The levels of 5-HT and 5-HIAA in the brains of rats and mice were determined by using the enzyme-linked immunosorbent assay method. Pathological changes in the brains of migraine rats were examined by immunohistochemistry. The protein expression of 5-HT 1B receptor, c-Fos, and c-Jun in the periaqueductal gray (PAG) of migraine rats was measured by Western blot. After preventive administration of RCXTAs to the nitroglycerin-induced migraine rats, the levels of 5-HT and 5-HIAA in the brain tissue were generally upregulated in all three RCXTA dose groups, a finding that was similar to that observed in the control group. Additionally, the 5-HT and 5-HIAA levels were significantly increased in the medium- and high-dose RCXTA groups when compared with the model group (p < 0.01). Therapeutical administration of RCXTAs to reserpine-induced migraine mice also inhibited the reduction of 5-HT and 5-HIAA in the brain (p < 0.01). Both immunohistochemistry and Western blot tests showed that RCXTAs pretreatment has significantly upregulated 5-HT 1B receptor expression and downregulated c-Jun expression in the nitroglycerin-induced migraine rats. RCXTAs exerted significant preventive and therapeutic effects on migraine via increasing the levels of 5-HT and 5-HIAA. Upregulation of the expression of monoamine neurotransmitter 5-HT 1B receptor and downregulation of the expression of c-Jun were the possible mechanisms. Image 1 [ABSTRACT FROM AUTHOR]

[Display omitted] • Nanoscale clay mineral-related pores dominate the pore system of the Da'anzhai shale. • TOC content, kerogen type, clay mineral content, and porosity are key controlling factors for oil content in shales. • Real (S 1-1 /TOC) and maximum ((S 1-1 + S 1-2)/TOC) movable oil index derived from multistep pyrolysis can be used to evaluate oil mobility. • Oil mobility is mainly influenced by the thermal maturity, physical properties, mineral composition, and oil occurrence state. Early Jurassic lacustrine shales in the Sichuan Basin contain significant resources potential and are one of the most important exploration targets in China. However, studies of these shales are limited and controlling factors on oil contents are poorly known despite the importance of such studies in evaluating favorable exploration targets and risks. In addition, effectively evaluating oil mobility is challenging in lacustrine shale exploration. Herein, lacustrine shales of the Lower Jurassic Da'anzhai Member from the Sichuan Basin are investigated through a series of experiments, including thin sections, field emission scanning electron microscopy, total organic carbon (TOC), X-ray diffraction, nitrogen adsorption, mercury intrusion capillary pressure, routine and multistep pyrolysis, and organic petrographic analysis. Our results show that four lithofacies can be identified in the Da'anzhai shale: organic-lean mixed shale with bioclastics (LM), organic-lean argillaceous shale with siliceous mineral concretions (LCM), laminated organic-rich mixed shale with bioclastics (RM), and laminated organic-rich argillaceous shale (RCM). The pore system is dominated by clay mineral-related (CM) pores, with significant contribution from nanopores. The TOC content is the primary factor that influences oil content, with kerogen type, clay mineral content, and porosity also having important effects. The influences of these factors on oil content are mainly controlled by the oil occurrence states and pore structures. The internal and surficial parts of the organic matter and the widely distributed nanoscale CM pores are the main storage spaces for oil. Oil mobility in the four shale lithofacies varies considerably: the oil mobility of the RCM shale is the greatest, and differences in oil mobility are mainly due to thermal maturity, physical properties, mineral composition, and oil occurrence state. Overall, RCM shale is the most favorable lithofacies for exploration in the Da'anzhai shale. The real movable oil index (S 1-1 /TOC×100) and the maximum movable oil index ((S 1-1 + S 1-2)/TOC×100) derived from multistep pyrolysis data can be used to evaluate oil mobility. Our findings may provide new insights into the evaluation of oil resource potential and the exploration of lacustrine shale. [ABSTRACT FROM AUTHOR]

China has a long history of earthquake records, and the Longmenshan fault system (LFS) is a famous earthquake zone. We believed that the LFS could be divided into three seismogenic zones (north, central, and south zones) based on the geological structures and the earthquake catalog. We applied the Bayesian probability method using extreme-value distribution of earthquake occurrences to estimate the seismic hazard in the LFS. The seismic moment, slip rate, earthquake recurrence rate, and magnitude were considered as the basic parameters for computing the Bayesian prior estimates of the seismicity. These estimates were then updated in terms of Bayes' theorem and historical estimates of seismicity in the LFS. Generally speaking, the north zone seemingly is quite peaceful compared with the central and south zones. The central zone is the most dangerous; however, the periodicity of earthquake occurrences for M = 8.0 is quite long (1,250 to 5,000 years). The selection of upper bound probable magnitude influences the result, and the upper bound magnitude of the south zone maybe 7.5. We obtained the empirical relationship of magnitude conversion for M and ML, the values of the magnitude of completeness Mc (3.5), and the Gutenberg-Richter b value before applying the Bayesian extreme-value distribution of earthquake occurrences method. [ABSTRACT FROM AUTHOR]

• Three triterpenoids and seven Δ22-ergosteroids were isolated from Omphalia lapidescens. • Compound 1 possesses a new 24,25,26,27-tetranorlanostane carbon skeleton. • The new ergosteroid 4 induced apoptosis in MDA-MB-231 and HGC-27 cells significantly. • Compound 4 regulated the procaspase-3 expression and the Bax/Bcl-2 expression ratio. Omphalia lapidescens Schroet. is a medicinal macrofungus in China that has shown good antitumor activity in recent research. To explore the potential cytotoxic compounds from O. lapidescens , the ethyl acetate soluble fraction of a 95% ethanol extract with cytotoxic activity was phytochemically investigated. A new tetranorlanostane triterpenoid (1) and a new ergosteroid (4), together with two known lanostanes (2 and 3) and six known Δ22-ergosteroids (5 − 10), were isolated. Notably, compound 1 possesses a new 24,25,26,27-tetranorlanostane carbon skeleton. All isolates, except compound 8 , were tested for cytotoxic activities using a human breast cancer cell line (MDA-MB-231) and a human gastric cancer cell line (HGC-27) in vitro. The new nortriterpenoid (1) exhibited no obvious cytotoxicity, while the known triterpenoid (3) showed significant cytotoxicity against MDA-MB-231 and HGC-27 cells. Compound 4 exhibited the highest cytotoxicity against MDA-MB-231 and HGC-27 cells, with IC 50 values of 11.33 ± 2.18 and 12.28 ± 3.64 μ M, respectively. Furthermore, Hoechst fluorescence 33342 staining and Western blot tests demonstrated that compound 4 induced apoptosis in MDA-MB-231 cells by downregulating procaspase-3 expression and upregulating the expression ratio of Bax/Bcl-2. [ABSTRACT FROM AUTHOR]

• Summary on chemical compositions and their pharmacological effects of Leonurus japonicus. • Abundant terpenoids and alkaloids are closely related to traditional efficacy of L. japonicus. • Alkaloids show remarkable effects on gynecological and cerebral-cardio vascular diseases. • Many Chinese patent medicines made by L. japonicus have been used in clinic in China. Leonurus japonicus Houtt. is a traditional medicinal herb with significant effects; dating back more than 1800 years, it is widely used in Asia. In traditional Chinese medicine, it is essential in the treatment of menstrual and delivery disorders caused by blood stasis, such as dysmenorrhea, amenorrhea, and postpartum hemorrhage. In the last three decades, many phytochemists, pharmacologists, and doctors have focused on the chemical components, pharmacological activities, and clinical applications of L. japonicus. More than 280 chemical compounds have been isolated from this plant. The effects of most of the terpenoids and alkaloids isolated from the plant have been found to be closely related to the traditional functions of L. japonicus. Owing to its excellent therapeutic effects for obstetrical and gynecological diseases, L. japonicus has been widely used in both ancient and modern times. Nowadays, it has also been developed into a series of Chinese patent medicines in clinics in China. This review summarizes the phytochemistry, pharmacology, and clinical applications of L. japonicus. [ABSTRACT FROM AUTHOR]

Abstract: The outbreak and widely spread of coronavirus disease 2019 (COVID-19) has become a global public health concern. COVID-19 has caused an unprecedented and profound impact on the whole world, and the prevention and control of COVID-19 is a global public health challenge remains to be solved. The retrospective analysis of the large scale tests of SARS-CoV-2 RNA may indicate some important information of this pandemic. We selected 12400 SARS-CoV-2 tests detected in Wuhan in the first semester of 2020 and made a systematic analysis of them, in order to find some beneficial clue for the consistent prevention and control of COVID-19.SARS-CoV-2 RNA was detected in suspected COVID-19 patients with real-time fluorescence quantitative PCR (RT-qPCR). The patients' features including gender, age, type of specimen, source of patients, and the dynamic changes of the clinical symptoms were recorded and statistically analyzed. Quantitative and qualitive statistical analysis were carried out after laboratory detection.The positive rate of SARS-CoV-2 was 33.02% in 12,400 suspected patients' specimens in Wuhan at the first months of COVID-19 epidemics. SARS-CoV-2 RT-qPCR test of nasopharyngeal swabs might produce 4.79% (594/12400) presumptive results. The positive rate of SARS-CoV-2 RNA was significantly different between gender, age, type of specimen, source of patients, respectively (P < .05). The median window period from the occurrence of clinical symptom or close contact with COVID-19 patient to the first detection of positive PCR was 2 days (interquartile range, 1-4 days). The median interval time from the first SARS-CoV-2 positive to the turning negative was 14 days (interquartile range, 8-19.25 days).This study reveals the comprehensive characteristics of the SARS-CoV-2 RNA detection from multiple perspectives, and it provides important clues and may also supply useful suggestions for future work of the prevention and treatment of COVID-19., Competing Interests: The authors have no conflicts of interests to disclose., (Copyright © 2021 the Author(s). Published by Wolters Kluwer Health, Inc.)

Background: The Covid-19 pandemic restricts children and adolescents from doing normal daily activities such as playing outdoors and going to school. The incidence and prevalence of myopia have increased during the COVID-19 pandemic. The aim of this study was to investigate and evaluate the impact of the home confinement during the COVID-19 pandemic on the progression of myopia among children and adolescents in Chongqing, China. Methods: The survey was conducted by using stratified samplings. Samples were randomly selected from the 2019 National Student Physique and Health Survey database, and their visual function and refractive data were compared with those in 2020. Vision-related behavior questionnaire including digital screen exposure was applied to investigate the correlation between eye parameter and eye health-related behavior. Results: A total of 1,733 and 1,728 students were enrolled in 2020 and 2019, respectively. The percentage of myopia students was 55.02% in 2020, which was higher than that in 2019 (44.62%). The mean uncorrected visual acuity (UCVA, LogMAR, 0.35 ± 0.42) in 2020 was higher than that in 2019 (0.27 ± 0.36, P < 0.001). The mean spherical equivalent (SE) refraction (-1.94 ± 2.13 D) in 2020 was lower than that in 2019 (-1.64 ± 5.49 D, P < 0.001). For students who used digital devices for online courses, the mean SE in the television group (-1.10 ± 1.49 D) was better than that in the computer group (-2.03 ± 2.37 D, P = 0.0017) and in the cell phone group (-2.02 ± 2.09 D, P = 0.0028). The average duration of online classes ( r = -0.27, P < 0.0001), the number of online classes per day ( r = -0.33, P < 0.0001), as well as digital screen exposure time ( r = -0.20, P < 0.0001) were negatively correlated with SE, and the average time of outdoor activity ( r = 0.20, P < 0.0001) was positively correlated with SE. Conclusions: Increased digital screen exposure contributes to myopic progression in children and adolescents of Chongqing during the COVID-19 pandemic. Suitable digital devices should be provided for online classes and outdoor activity should be advocated to prevent myopic pandemic., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2021 Wang, Zhu, Zheng, Ji, Xiang, Lv, Xiong, Li, Yi, Huang, Zhang, Liu, Wan and Hu.)

Ethnopharmacological Relevance: Dysmenorrhea is one of the most common gynecological problems among menstruating females. Blood-activating and stasis-resolving herbs (BASRHs) have been employed to be the first choice for treating dysmenorrhea in China. Especially, the essential oils of some BASRHs have been confirmed to play important roles in the treatment of dysmenorrhea, but the constituents and uterine smooth muscle relaxant activity of some commonly used BASRH essential oils have not been fully assessed, and whether there are differences in the constituents and anti-dysmenorrhea effect among BASRH essential oils has not been evaluated., Aim of the Study: This study aims to systematically investigate the chemical constituents of 10 BASRH essential oils and assess their uterine smooth muscle relaxant activity and the preliminary mechanism of the most effective essential oil., Materials and Methods: The chemical constituents of 10 BASRH essential oils were analyzed by Gas Chromatography-Mass Spectrometer. A rat model of dysmenorrhea in vitro was established to investigate the uterine smooth muscle relaxant activity of 10 kinds of essential oils. Rat isolated uterus strips were given different dose of 10 kinds of essential oils (0.04, 0.08, 0.16 mg/mL). The contractile responses were recorded with Power Lab recording system, and contractile tension, contractile frequency, and contractile activity were evaluated. The preliminary mechanism of the essential oil of the rhizomes of Curcuma phaeocaulis Valeton (CPEO) was assessed using a rat model of dysmenorrhea in vivo and in vitro, and rats were given the CPEO (15, 30, and 60 mg/kg) by gavage. The level of Ca 2+ in uterine tissue of rats was determined by methyl thyme phenol blue colorimetric and Bradford methods. The effects of CPEO on extracellular Ca 2+ influx and intracellular Ca 2+ release were evaluated using the isolated uterus., Results: The results of Gas Chromatography-Mass Spectrometer analysis showed that more than 81 components (content: 1% max appearance) were identified. The main components of the 10 BASRH essential oils were found to be monoterpenoids, sesquiterpenoids, diterpenoids, aromatics, aliphatics, and phthalides. The study of in vitro smooth muscle relaxant activity demonstrated that all the essential oils except the essential oil of the roots of Cyathula officinalis K.C.Kuan markedly decrease the contractile activity, tension, and frequency (P < 0.05 or P < 0.01). Among these oils, CPEO has the most pronounced effect. Further in vivo studies indicated that CPEO can significantly decrease the level of Ca 2+ in uterine tissue when compared with the model group (P < 0.05 or P < 0.01). In vitro studies indicated that CPEO can inhibit the extracellular Ca 2+ influx and intracellular Ca 2+ release in favor of uterine relaxation., Conclusions: BASRH essential oils play an important role in inhibiting uterine smooth muscle contractions, and sesquiterpenoids and phthalides in BASRH essential oils are important active compounds for relaxing uterine smooth muscle. CPEO is a favorable candidate for developing anti-dysmenorrhea drugs., (Copyright © 2020 Elsevier B.V. All rights reserved.)

Fuzi, a well-known traditional Chinese medicine developed from the lateral roots of Aconitum carmichaelii Debx., has been widely used for the treatment of heart failure. In order to search for active compounds from Fuzi, a phytochemical study was performed, which resulted in the isolation of 14 aminoalcohol-diterpenoid alkaloids, including one new compound (1). Their cardioprotective effects against doxorubicin-induced toxicity in H9c2 cells were evaluated. All of the alkaloids showed cardioprotective effects in a nonmonotonic concentration-response manner, with the maximum protection rates ranging from 17.96 ± 2.93% to 98.31 ± 0.35%. Compound 5 exhibited the most potent cardioprotective activity. Taking the maximum protection rate as an indicator, the preliminary structure-activity relationship analysis indicated that the substitutions of C-1, C-13, C-15, C-16, and N and the configurations of OMe-6 and OH-15 are important structural features for the cardioprotective activities of the aminoalcohol-diterpenoid alkaloids., (Copyright © 2021 Elsevier B.V. All rights reserved.)

The clinical manifestations of thyroid diseases in elderly patients are often atypical. This study aimed to establish reference intervals for thyroid function in the elderly in order to help diagnose thyroid diseases in this population. A total of 5345 healthy individuals were examined and divided into three groups according to their age: 4297 individuals aged < 65 years (19-64), 719 individuals aged between 65 and 79 years, and 329 individuals aged between 80 and 100 years. Levels of free triiodothyronine (FT3), free thyroxine (FT4), thyroid-stimulating hormone (TSH), thyroid peroxidase antibody, and thyroglobulin antibody were measured in these subjects by using a fully automated analyzer. The following free triiodothyronine, free thyroxine, and thyroid-stimulating hormone reference intervals were obtained from each age group: For individuals aged < 65 years (19-64 years), FT3, FT4, and TSH were 3.40-6.44, 10.26-19.25 pmol/L and 0.50-4.81 μIU/mL, respectively. For individuals aged between 65 and 79 years, FT3, FT4 and TSH ranged between 3.01-5.91, 10.04-19.76 pmol/L, and 0.54-5.51 μIU/mL, respectively. For individuals aged between 80 and 100 years, FT3, FT4, and TSH varied between 2.82-5.57, 9.79-21.22 pmol/L, 0.31-6.28 μIU/mL respectively. FT3 concentration was lower and the concentrations of FT4 and TSH were higher in individuals aged ≥ 65 years than in those aged <65 years (P<0.0001; P = 0.0039; P<0.0001, respectively). In conclusion, establishment of a reference interval would allow clinicians to diagnose diseases more accurately and easily., Competing Interests: All authors declare no conflict of interest for this manuscript.

Three new sesquiterpenoids, (+)-(1R,2S,3R,4S,5R,6S,9R)-3,11,12-trihydroxypicrotoxane-2(15)-lactone (1), (-)-(1S,2R,3S,4R,5S,6R,9S,12R)-3,11,13-trihydroxypicrotoxane-2(15)-lactone (2), and (+)-(1R,5R,6S,8R,9R)-8,12-dihydroxy-copacamphan-3-en-2-one (3), together with five known compounds, were isolated from the n-butanol soluble fraction of a 95% EtOH extract of the stems of Dendrobium nobile. Their structures were determined by extensive spectroscopic analysis. Particularly, to solve difficult stereochemical problems, electronic circular dichroism calculations, NMR data calculations, and a single-crystal X-ray diffraction were performed. Interestingly, compounds 1 and 2 were picrotoxinin-type sesquiterpenoids with an unusual C15,2-lactone ring. All new sesquiterpenoids (1-3) showed a significant neuroprotective activity against H 2 O 2 -induced oxidative damage in PC12 cells. Notably, at 25 and 50 μM, compounds 1 and 2 showed the best protective effects, even better than the positive control (vitamin E)., (Copyright © 2019. Published by Elsevier B.V.)

Introduction: Acute lateral patellar dislocation is a very common condition in orthopedics, especially among adolescents and physically active patients. To evaluate distinct medial patellofemoral ligament (MPFL) injury patterns and the associated knee pathology after acute lateral patellar dislocation (ALPD) using magnetic resonance imaging (MRI) studies, which is essential for the development of treatment protocols., Materials and Methods: MRI images of 74 ALPD patients were taken between January 2015 to December 2016. Images were evaluated using standardized protocols., Results: The prevalence of MPFL injury following ALPD was 97.3% (72/74 patients). Among the 72 patients with MPFL, the prevalence of Type Ⅰ injury was 26.4% (19/72). Since only bone marrow edema and a partial tear were showed on MRI of these patients, conservative treatment was given. Tear of the MPFL occurred at the patellar attachment (Type Ⅱa) in 16 patients (16/72, 22.2%), at the middle area of the ligament (Type Ⅱb) in 5 patients (5/72, 6.9%), and at the femoral attachment (Type Ⅱc) in 27 patients (27/72, 37.5%). For Type Ⅱ injuries, all patients had the surgery to reconstruct the MPFL. The prevalence of Type Ⅲ MPFL injury was 6.9% (5/72) after the surgery., Conclusion: MPFL injury of is a common sequel following ALPD. We assessed the distinct injury pattern and associated pathology of MPFL using MRI studies. A good understanding of the injury pattern and associated knee pathology of MPFL is essential in managing patients with ALPD, especially if surgical intervention is considered., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

Microsatellites are simple sequence repeats with a high degree of polymorphism in the genome; they are used as DNA markers in many molecular genetic studies. Using traditional methods such as the magnetic beads enrichment method, only a few microsatellite markers have been isolated from the Chinese mitten crab Eriocheir sinensis, as the crab genome sequence information is unavailable. Here, we have identified a large number of microsatellites from the Chinese mitten crab by taking advantage of Solexa genomic surveying. A total of 141,737 SSR (simple sequence repeats) motifs were identified via analysis of 883 Mb of the crab genomic DNA information, including mono-, di-, tri-, tetra-, penta- and hexa-nucleotide repeat motifs. The number of di-nucleotide repeat motifs was 82,979, making this the most abundant type of repeat motif (58.54%); the second most abundant were the tri-nucleotide repeats (42,657, 30.11%). Among di-nucleotide repeats, the most frequent repeats were AC motifs, accounting for 67.55% of the total number. AGG motifs were the most frequent (59.32%) of the tri-nucleotide motifs. A total of 15,125 microsatellite loci had a flanking sequence suitable for setting the primer of a polymerase chain reaction (PCR). To verify the identified SSRs, a subset of 100 primer pairs was randomly selected for PCR. Eighty two primer sets (82%) produced strong PCR products matching expected sizes, and 78% were polymorphic. In an analysis of 30 wild individuals from the Yangtze River with 20 primer sets, the number of alleles per locus ranged from 2--14 and the mean allelic richness was 7.4. No linkage disequilibrium was found between any pair of loci, indicating that the markers were independent. The Hardy-Weinberg equilibrium test showed significant deviation in four of the 20 microsatellite loci after sequential Bonferroni corrections. This method is cost- and time-effective in comparison to traditional approaches for the isolation of microsatellites.

Objective: To understand the immunological status of Japanese encephalitis (JE) antibodies amongst migrant workers and to provide epidemiological basis for public health strategies on JE prevention and control in Shenzhen., Methods: A multi-stage random sampling method was used, and 1003 migrant workers aged 18 to 60 from 44 factories were investigated and their serum specimens were collected. The enzyme-linked immunosorbent assay (ELISA) was used to detect JE antibodies qualitatively., Results: The gross IgG seroprevalence rate for JE was 20.2% (203/1003). Sex-specified seroprevalence was 21.2% (103/485) for male and 19.3% (100/518) for female, respectively (χ(2) = 579, P > 0.05). Age-specific seropositive rates were 22.6% (12/53) for those below 20 years old, 18.7% (120/642) for those between 20-years old, 26.0% (58/223) for those between 30-years old and 15.3% (13/85) for those on or above 40 years old (χ(2) = 7.96, P > 0.05). Proportions for self-reported positive immunization, non-immunization and unclear immunization history were 22.1% (30/136), 22.1% (51/231) and 19.2% (122/636), respectively (χ(2) = 501, P > 0.05). Seroprevalence by region of origins showed that workers from Guangdong province was the highest (30.5%, 50/164), followed by workers from Guangxi (29.7%, 22/74) whilst workers from Shan(3)xi (5.4%, 2/37) had the lowest rate. Seroprevalence rate for managers (29.0%, 31/107) was higher than that of technicians (7.1%, 1/14) (χ(2) = 21.78, P < 0.05). Serological positive rate of workers with university or above educational background was the highest (32.7%, 16/49), followed by that for individuals with college degree (10.3%, 10/97) (χ(2) = 13.02, P < 0.05)., Conclusion: No associations are detected between JE seroprevalence and age, or sex, or self-reported immunization histories amongst migrant labor workers in Shenzhen. However, correlations between JE serological positive rate and region of origins, occupation and educational attainment are found to be significant. The gross seroprevalence of JE antibodies suggests that the level of JE antibodies amongst Shenzhen migrant workers is low and the population immunity barrier has yet to be established. It is necessary to strengthen prevention and control strategies of JE among labor workers of Shenzhen.

Objective: To study the simple infection and super/co-infection of HAV-HEV, HGV in patients with viral hepatitis., Methods: Using EIA method to detect anti-HAV IgM, HBV serum markers, anti-HCV IgM, anti-HDV IgM, anti-HEV IgM, anti-HGV IgM in viral hepatitis patients with different clinical types., Results: Seventy-three percent patients (154/210) had HBV infection markers, twenty-nine percent patients (61/210) had HAV infection marker, eight percent patients (17/210) had HCV, HDV infection markers, ten percent patients (21/210) had HEV infection and seven percent patients (15/210) had HGV infection. Only nine percent patients (20/210) had viral hepatitis serum markers negative. In all clinical types, sixty-one percent patients had only one type hepatitis virus infection, thirty-two percent patients had two types of hepatitis virus super/co-infection, six percent patients had three types of hepatitis virus super/co-infection. Super/co-infection often occurred in patients who had cirrhosis or hepatic failure., Conclusion: HBV and HAV infection is very common in viral hepatitis patients, whereas HCV, HDV, HEV and HGV infection is relatively low; double super/co-infection of HAV-HEV, HGV frequently occurs in severe patients with viral hepatitis.