Expression of water-soluble nucleocapsid protein of SARS-CoV-2 and analysis of its immunogenicity.

Coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) continues to be a major public health concern. Nucleocapsid (N) protein is the most abundant structural protein on SARS-CoV-2 virions and induces the production of antibodies at the early stage of infection. Large-scale preparation of N protein is essential for the development of immunoassays to detect antibodies to SARS-CoV-2 and the control of virus transmission. In this study, expression of water-soluble N protein was achieved through inducing protein expression at 25°C with 0.5 mM IPTG for 12 h. Western blot and ELISA showed that recombinant N protein could be recognized by sera collected from subjects immunized with Sinovac inactivated SARS-CoV-2 vaccine. Four monoclonal antibodies namely 2B1B1, 4D3A3, 5G1F8, and 7C6F5 were produced using hybridoma technology. Titers of all four monoclonal antibodies in ELISA reached more than 1.28×10 6.0. Moreover, all monoclonal antibodies could react specifically with N protein expressed by transfection of pcDNA3.1-N into BHK-21 cells in IPMA and IFA. These results indicated that water-soluble N protein retained high immunogenicity and possessed the same epitopes as that of native N protein on virions. In addition, the preparation of water-soluble N protein and its monoclonal antibodies laid the basis for the development of immunoassays for COVID-19 detection.

[Clinical features, risk factors and prognosis of idiopathic dilated cardiomyopathy complicated by ischemic stroke].

Objective: To analyze the clinical features, risk factors and prognosis of idiopathic dilated cardiomyopathy (DCM) complicated with ischemic stroke (IS) (DCM-IS). Methods: The clinical data of patients with idiopathic DCM (n=613) in Beijing Anzhen Hospital, Liangxiang Hospital and Fuxing Hospital from January 2016 to December 2020 were retrospectively collected, and among them, 123 cases were DCM-IS. Clinical features of patients with DCM-IS were summarized and multivariate logistic regression model was utilized to analyze the independent risk factors of DCM-IS. Furthermore, 1-year follow-up was conducted and Kaplan-Meier curve was adopted to analyze the prognosis of DCM, using all-cause death and heart transplantation as adverse outcomes. Results: Among the 70 patients with DCM-IS, 6 patients (8.6%, 6/70) were in accordance with the subtype of large artery atherosclerosis, and 47 patients (67.1%, 47/70) were in line with the subtype of cardiogenic embolism, and small artery occlusion subtype (ie, lacunar infarction) were detected in 17 cases (24.3%, 17/70). Hypertension [odds ratio (OR)=1.617, 95% confidence interval (CI): 1.049-2.491, P=0.029], hyperlipidemia (OR=1.918, 95%CI: 1.198-3.073, P=0.007), atrial fibrillation (AF) (OR=1.617, 95%CI: 1.016-2.572, P=0.043), lower estimated glomerular filtration rate (eGFR) (OR=0.986, 95%CI: 0.977-0.996, P=0.005) and a higher incidence of intracardiac thrombus (OR=6.127, 95%CI: 3.174-11.827, P<0.001) were risk factors for DCM-IS. The overall 1-year survival rate was lower in DCM-IS patients (70.7%) than DCM patients without stroke (83.6%, P=0.004), and the main causes of death included obstinate heart failure (3 cases of DCM-IS, and 5 cases of non-DCM-IS) and malignant arrhythmia (DCM-IS) (22 cases of DCM-IS, and 18 cases of non-DCM-IS). Conclusions: Among IS patients with idiopathic DCM, cardioembolism is the most common, followed by lacunar infarction, and the large-artery atherosclerotic subtype is the least common.Hypertension, hyperlipidemia, AF, lower eGFR value and higher incidence of intracardiac thrombus are risk factors for DCM-IS. DCM patients complicated with IS have poor short-term prognosis, and obstinate heart failure and malignant arrhythmia are their main causes of death.

[Evaluation of safety and clinical efficacy of bilateral percutaneous kyphoplasty in treatment of osteoporotic thoraco-lumbar burst fractures].

Objective: To evaluate the safety and clinical efficacy of bilateral percutaneous kyphoplasty (PKP) in the treatment of osteoporotic vertebral burst fractures. Methods: It was a prospective study, 28 patients with osteoporotic thoraco-lumbar burst fractures who were treated in Beijing Chao-Yang Hospital from January 2021 to July 2021 were included, including 10 males and 18 females, with a median age of 73.6 years (range: 56.0-87.0 years). The X-ray radiographs, bone mineral density (BMD), CT three-dimensional reconstruction scan and MRI were taken and measured before operation to observe the fracture location and the posterior wall of the vertebral body, and further to determine the diagnosis. The X-ray radiographs and CT three-dimensional reconstruction scans were taken on the first day after operation and the last follow-up to observe whether there were bone cement leakage or not. The changes of kyphosis angle (KA), the height of anterior wall (HAW) and the height of posterior wall (HPW) before the operation, on the 1st day post operation and at the last follow-up were recorded. The visual analogue scale (VAS) of back pain and Oswestry dysfunction index (ODI) before the operation, 1 day post operation and at the last follow-up were used to evaluate the clinical effect of the operation. Results: All the patients were followed up for (12.2±6.0) months. The HAW on the 1st day post operation [(22.5±2.0) mm] was significantly increased as compared with that before the operation [(21.2±2.4) mm] (P<0.05). The HAW at the last follow-up [(18.9±1.6) mm] decreased signficantly as compared with that on the 1st day post opertion [(22.5±2.0) mm] (P<0.05). The HPW was also significantly corrected after surgery (P<0.05). At the end of the follow-up, the HPW [(27.2±1.3) mm] was comparable with that on the 1st day after surgery [(27.5±1.6) mm] (P>0.05). The KA on the 1st day after the operation (14.2°±1.5°) decreased significantly when compared with that before the operation (18.8°±1.3°) (P<0.05), but it was increased to 17.6°±1.4° at the last follow-up and was higher than that on the 1st day after the operation (P<0.05). There were bone cement leakage in 5 cases and adjacent vertebral fracture in 1 case. The VAS and ODI scores were all significantly lower on the 1st day and at last follow-up than that before the operation (all P<0.05). Conclusions: Bilateral PKP is effective, safe and reliable in the treatment of osteoporotic vertebral burst fracture. Careful evaluation of preoperative imaging data, accurate puncture and timing of bone cement injection are the key factors to ensure the success of the operation.

Exploring Lorentz Invariance Violation from Ultrahigh-Energy γ Rays Observed by LHAASO.

Recently, the LHAASO Collaboration published the detection of 12 ultrahigh-energy γ-ray sources above 100 TeV, with the highest energy photon reaching 1.4 PeV. The first detection of PeV γ rays from astrophysical sources may provide a very sensitive probe of the effect of the Lorentz invariance violation (LIV), which results in decay of high-energy γ rays in the superluminal scenario and hence a sharp cutoff of the energy spectrum. Two highest energy sources are studied in this work. No signature of the existence of the LIV is found in their energy spectra, and the lower limits on the LIV energy scale are derived. Our results show that the first-order LIV energy scale should be higher than about 10^{5} times the Planck scale M_{Pl} and that the second-order LIV scale is >10^{-3}M_{Pl}. Both limits improve by at least one order of magnitude the previous results.

Constraints on Heavy Decaying Dark Matter from 570 Days of LHAASO Observations.

The kilometer square array (KM2A) of the large high altitude air shower observatory (LHAASO) aims at surveying the northern γ-ray sky at energies above 10 TeV with unprecedented sensitivity. γ-ray observations have long been one of the most powerful tools for dark matter searches, as, e.g., high-energy γ rays could be produced by the decays of heavy dark matter particles. In this Letter, we present the first dark matter analysis with LHAASO-KM2A, using the first 340 days of data from 1/2-KM2A and 230 days of data from 3/4-KM2A. Several regions of interest are used to search for a signal and account for the residual cosmic-ray background after γ/hadron separation. We find no excess of dark matter signals, and thus place some of the strongest γ-ray constraints on the lifetime of heavy dark matter particles with mass between 10^{5} and 10^{9} GeV. Our results with LHAASO are robust, and have important implications for dark matter interpretations of the diffuse astrophysical high-energy neutrino emission.

Circ_NCKAP1 promotes skin basal cell carcinoma progression by sponging the miR-148b-5p/HSP90 axis.

OBJECTIVE: Skin basal cell carcinoma (BCC) is the most common malignant skin tumor. Recent studies demonstrated that circular RNAs (circRNAs) are implicated in tumorigenesis and may represent potential therapeutic targets. The aim of the present study was to explore the expression profiles of circRNAs and their role in skin BCC. MATERIALS AND METHODS: Three pairs of skin BCC tissues and adjacent tissues were used to perform a circRNA microarray for screening of circRNA expression profiles. Circ_NCKAP1 was selected as a target circRNA by RT-qPCR verification and bioinformatics analysis. The effect of circ_NCKAP1 knockdown on cell proliferation and apoptosis was assessed using CCK8 and Annexin V-FITC/PI assays, and its regulation over the miR-148b-5p/HSP90 axis was assessed by dual-luciferase reporter assay. RESULTS: Circ_NCKAP1 was found to be significantly upregulated in skin BCC tissues (p<0.05). In vitro loss-of-function assays demonstrated that circ_NCKAP1 knockdown markedly inhibited cell proliferation and promoted cell apoptosis (p<0.05). Moreover, Dual-Luciferase reporter assay identified that circ_NCKAP1 could bind to miR-148b-5p directly, and HSP90 was targeted by miR-148b-5p. CONCLUSIONS: Circ_NCKAP1 can promote skin BCC progression by sponging the miR-148b-5p/HSP90 axis, and circ_NCKAP1 may be a potential target for skin BCC therapy.

Peta-electron volt gamma-ray emission from the Crab Nebula.

The Crab Nebula is a bright source of gamma rays powered by the Crab Pulsar's rotational energy through the formation and termination of a relativistic electron-positron wind. We report the detection of gamma rays from this source with energies from 5 × 10-4 to 1.1 peta-electron volts with a spectrum showing gradual steepening over three energy decades. The ultrahigh-energy photons imply the presence of a peta-electron volt electron accelerator (a pevatron) in the nebula, with an acceleration rate exceeding 15% of the theoretical limit. We constrain the pevatron's size between 0.025 and 0.1 parsecs and the magnetic field to ≈110 microgauss. The production rate of peta-electron volt electrons, 2.5 × 1036 ergs per second, constitutes 0.5% of the pulsar spin-down luminosity, although we cannot exclude a contribution of peta-electron volt protons to the production of the highest-energy gamma rays.

Extended Very-High-Energy Gamma-Ray Emission Surrounding PSR J0622+3749 Observed by LHAASO-KM2A.

We report the discovery of an extended very-high-energy (VHE) gamma-ray source around the location of the middle-aged (207.8 kyr) pulsar PSR J0622+3749 with the Large High-Altitude Air Shower Observatory (LHAASO). The source is detected with a significance of 8.2σ for E>25 TeV assuming a Gaussian template. The best-fit location is (right ascension, declination) =(95.47°±0.11°,37.92°±0.09°), and the extension is 0.40°±0.07°. The energy spectrum can be described by a power-law spectrum with an index of -2.92±0.17_{stat}±0.02_{sys}. No clear extended multiwavelength counterpart of the LHAASO source has been found from the radio to sub-TeV bands. The LHAASO observations are consistent with the scenario that VHE electrons escaped from the pulsar, diffused in the interstellar medium, and scattered the interstellar radiation field. If interpreted as the pulsar halo scenario, the diffusion coefficient, inferred for electrons with median energies of ∼160 TeV, is consistent with those obtained from the extended halos around Geminga and Monogem and much smaller than that derived from cosmic ray secondaries. The LHAASO discovery of this source thus likely enriches the class of so-called pulsar halos and confirms that high-energy particles generally diffuse very slowly in the disturbed medium around pulsars.

Ultrahigh-energy photons up to 1.4 petaelectronvolts from 12 γ-ray Galactic sources.

The extension of the cosmic-ray spectrum beyond 1 petaelectronvolt (PeV; 1015 electronvolts) indicates the existence of the so-called PeVatrons-cosmic-ray factories that accelerate particles to PeV energies. We need to locate and identify such objects to find the origin of Galactic cosmic rays1. The principal signature of both electron and proton PeVatrons is ultrahigh-energy (exceeding 100 TeV) γ radiation. Evidence of the presence of a proton PeVatron has been found in the Galactic Centre, according to the detection of a hard-spectrum radiation extending to 0.04 PeV (ref. 2). Although γ-rays with energies slightly higher than 0.1 PeV have been reported from a few objects in the Galactic plane3-6, unbiased identification and in-depth exploration of PeVatrons requires detection of γ-rays with energies well above 0.1 PeV. Here we report the detection of more than 530 photons at energies above 100 teraelectronvolts and up to 1.4 PeV from 12 ultrahigh-energy γ-ray sources with a statistical significance greater than seven standard deviations. Despite having several potential counterparts in their proximity, including pulsar wind nebulae, supernova remnants and star-forming regions, the PeVatrons responsible for the ultrahigh-energy γ-rays have not yet been firmly localized and identified (except for the Crab Nebula), leaving open the origin of these extreme accelerators.

Biotransformation of insecticide flonicamid by Aminobacter sp. CGMCC 1.17253 via nitrile hydratase catalysed hydration pathway.

AIMS: This study evaluates flonicamid biotransformation ability of Aminobacter sp. CGMCC 1.17253 and the enzyme catalytic mechanism involved. METHODS AND RESULTS: Flonicamid transformed by resting cells of Aminobacter sp. CGMCC 1.17253 was carried out. Aminobacter sp. CGMCC 1.17253 converts flonicamid into N-(4-trifluoromethylnicotinoyl) glycinamide (TFNG-AM). Aminobacter sp. CGMCC 1.17253 transforms 31·1% of the flonicamid in a 200 mg l-1 conversion solution in 96 h. Aminobacter sp. CGMCC 1.17253 was inoculated in soil, and 72·1% of flonicamid with a concentration of 0·21 µmol g-1 was transformed in 9 days. The recombinant Escherichia coli expressing Aminobacter sp. CGMCC 1.17253 nitrile hydratase (NHase) and purified NHase were tested for the flonicamid transformation ability, both of them acquired the ability to transform flonicamid into TFNG-AM. CONCLUSIONS: Aminobacter sp. CGMCC 1.17253 transforms flonicamid into TFNG-AM via hydration pathway mediated by cobalt-containing NHase. SIGNIFICANCE AND IMPACT OF THE STUDY: This is the first report that bacteria of genus Aminobacter has flonicamid-transforming ability. This study enhances our understanding of flonicamid-degrading mechanism. Aminobacter sp. CGMCC 1.17253 has the potential for bioremediation of flonicamid pollution.

[Using structured decision-making to identify the appropriate type of entity for the centers for disease control and prevention of China].

Objective: To develop evidence-based appropriate type of entity for the Centers for Disease Control and Prevention in order to improve the performance of disease control and prevention system in China. Methods: This study firstly proposed the core functions and essential public health programs for the Centers for Disease Control and Prevention. Using Structured Decision-Making, this study presented three alternative options for type of entity to make essential public health programs succeed, and reviewed the pros and cons of alternative options based on 15 evaluation indicators. Questionnaires were distributed to 47 stakeholders between April 10 and April 20 of 2020. Finally, an appropriate type of entity for the Centers for Disease Control and Prevention was identified by using both qualitative and quantitative methods. Results: A total of 47 stakeholders ranked alternative options. Aggregated scores of each alternative option was computed after weighting each indicators. The results shows that Option 1(professional technical civil service organization)has the highest score (58.22). Conclusion: Professional technical civil service organization is appropriate type of entity for Centers for Disease Control and Prevention.

Icariin promotes mouse hair follicle growth by increasing insulin-like growth factor 1 expression in dermal papillary cells.

BACKGROUND: Icariin is a major flavonoid isolated from Epimedium spp. leaves (Epimedium Herba), and has multiple pharmacological functions, including anti-angiogenesis, anti-oxidant, anti-inflammatory and immunoprotective effects. AIM: To investigate whether icariin can stimulate growth of hair follicles in mice and the underlying mechanism. METHODS: In vitro, the effect of icariin on hair growth was assessed by using a vibrissae hair follicle (VHF) organ-culture model. The proliferation of hair matrix keratinocytes and the expression of insulin-like growth factor (IGF)-1 in follicles were examined by double immunostaining for 5-bromo-2'-deoxyuridine and IGF-1, in the presence or absence of icariin. Dermal papilla cells (DPCs) were cultured and IGF-1 level was measured by reverse transcription-PCR and ELISA after icariin treatment. In vivo, the effect of icariin on hair growth was examined by gavage feeding of icariin to mice whose backs had been depilated, and the conversion of telogen to anagen hair was observed. RESULTS: Treatment with icariin promoted hair shaft elongation, prolonged the hair cycle growth phase (anagen) in cultured VHFs, and accelerated transition of hair cycle from telogen to anagen phase in the dorsal skin of mice. There was significant proliferation of matrix keratinocytes and an increased level of IGF-1 in cultured VHFs. Moreover, icariin treatment upregulated IGF-1 mRNA expression in DPCs and increased IGF-1 protein content in the conditioned medium of DPCs. CONCLUSIONS: These results suggest that icariin can promote mouse hair follicle growth via stimulation of IGF-1 expression in DPCs.

Effects of extracellular matrix on the growth characteristics of human dermal papillae cells in vitro.

BACKGROUND: In humans, dermal papillae cells (DPCs) are surrounded by basal membranes. However, conventional in vitro culture conditions for DPCs do not include extracellular matrix (ECM). AIM: To investigate the effects of different ECM types on the characteristics of cultured human DPCs. METHODS: Freshly isolated human DPCs were inoculated onto plates precoated with type IV collagen, fibronectin, Matrigel or hyaluronate. Cell migration, growth and viability were measured. Real-time quantitative (q)PCR and western blotting were used to detect the influence of different ECM types on the expression of DPC-specific biomarkers. RESULTS: In planar culture, type IV collagen and fibronectin had a beneficial effect on the migration, aggregation and viability of DPCs, in contrast to Matrigel and hyaluronate. Real-time qPCR revealed that significantly increased expression of mRNA was seen only for neural cell adhesion molecule (NCAM) and α-smooth muscle actin (α-SMA) in the Matrigel group, whereas versican, NCAM and α-SMA all decreased significantly in the hyaluronate group. In the type IV collagen and fibronectin groups, mRNA expression of the above genes did not change significantly. Western blotting indicated that there were no significant differences in expression of the above proteins between the four groups and the control group. CONCLUSION: In planar culture, exogenous ECM types (Matrigel, type IV collagen, hyaluronate and fibronectin) changed the growth characteristics of DPCs, but they did not affect the characteristics associated with the biological functions of DPCs.

Biotype status and distribution of Bemisia tabaci (Hemiptera: Aleyrodidae) in Shandong province of China based on mitochondrial DNA markers.

Bemisia tabaci has caused significant crop losses in China during the last decade. Recent research has shown that two potentially invasive variants, biotypes B and Q, have been found in several regions of China. Our objective was to determine the biotype status and the distribution of B. tabaci in Shandong province, an important agricultural region of China. Based on mitochondrial DNA markers, both biotypes B and Q were detected, with B being the predominant biotype. The results indicate that the more recently introduced biotype Q has not only been located in China but also has established and spread in some regions.