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1.
Zootaxa ; 4920(3): zootaxa.4920.3.10, 2021 Jan 29.
Artigo em Inglês | MEDLINE | ID: mdl-33756662

RESUMO

A new species, Pluviam guangxiensis is described from Guangxi Province, China. It is distinct from the known genera and species of Podoscirtinae. Details are provided. Thus, a new genus, with one new species, was established. Supplementary information relating to Xuanwua motuoensis He, 2015, which is very similar is provided.


Assuntos
Gryllidae , Ortópteros , Distribuição Animal , Estruturas Animais , Animais , Tamanho Corporal , China , Masculino , Tamanho do Órgão
2.
Phytomedicine ; 84: 153505, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33626426

RESUMO

BACKGROUND: Ischemic stroke (IS) is a major neurological condition associated with extremely high morbidity and mortality worldwide. Oxymatrine (OMT), a quinolizidine alkaloid extracted from the root of Sophora flavescens, has neuroprotective properties and protects against IS. However, whether its protective effect involves alterations in the integrity of the blood-brain barrier (BBB) is unknown. PURPOSE: Here, we used in vivo and in vitro models of IS to evaluate the protective effects of OMT and to establish whether its effects are mediated via the modulation of the BBB function. METHODS: We assessed the effects of OMT by using neurological function scores, triphenyltetrazolium chloride staining, Nissl staining, and terminal deoxynucleotidyl transferase dUTP nick end labeling. RESULTS: OMT significantly prevented cellular damage, improved neurological function, and reduced BBB permeability in a mouse model of cerebral ischemia-reperfusion. Additionally, OMT protected the function of the tight junctions of bEend.3 cells against the consequences of oxygen-glucose deprivation. Furthermore, intracranial lentivirus injection of short hairpin RNA targeting Cav1 decreased caveolin-1 expression and inhibited the neuroprotective effects of OMT. CONCLUSIONS: OMT attenuated ischemia-reperfusion injury-induced damage to the BBB, and this neuroprotective action was at least partially dependent on the expression levels of CAV1 and MMP9 proteins. Therefore, OMT may offer effective protection against BBB injury induced by ischemia-reperfusion episodes.

3.
Preprint | bioRxiv | ID: ppbiorxiv-432424

RESUMO

As the SARS-CoV-2 pandemic is still ongoing and dramatically influences our life, the need for recombinant proteins for diagnostics, vaccine development, and research is very high. The spike (S) protein, and particularly its receptor binding domain (RBD), mediates the interaction with the ACE2 receptor on host cells and may be modulated by its structural features. Therefore, well characterized recombinant RBDs are essential. We have performed an in-depth structural and functional characterization of RBDs expressed in Chinese hamster ovary (CHO) and human embryonic kidney (HEK293) cells. To structurally characterize the native RBDs (comprising N- and O-glycans and additional posttranslational modifications) a multilevel mass spectrometric approach was employed. Released glycan and glycopeptide analysis were integrated with intact mass analysis, glycan-enzymatic dissection and top-down sequencing for comprehensive annotation of RBD proteoforms. The data showed distinct glycosylation for CHO- and HEK293-RBD with the latter exhibiting antenna fucosylation, higher level of sialylation and a combination of core 1 and core 2 type O-glycans. Additionally, from both putative O-glycosylation sites, we could confirm that O-glycosylation was exclusively present at T323, which was previously unknown. For both RBDs, the binding to SARS-CoV-2 antibodies of positive patients and affinity to ACE2 receptor was addressed showing comparable results. This work not only offers insights into RBD structural and functional features but also provides a workflow for characterization of new RBDs and batch-to-batch comparison.

4.
Preprint | bioRxiv | ID: ppbiorxiv-428568

RESUMO

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) cause the most serious pandemics of Coronavirus Disease 2019 (COVID-19), which threatens human health and public safety. SARS-CoV-2 spike (S) protein uses angiotensin-converting enzyme 2 (ACE2) as recognized receptor for its entry into host cell that contributes to the infection of SARS-CoV-2 to hosts. Using computational modeling approach, this study resolved the evolutionary pattern of bonding affinity of ACE2 in 247 jawed vertebrates to the spike (S) protein of SARS-CoV-2. First, high-or-low binding affinity phenotype divergence of ACE2 to the S protein of SARS-CoV-2 has appeared in two ancient species of jawed vertebrates, Scyliorhinus torazame (low-affinity, Chondrichthyes) and Latimeria chalumnae (high-affinity, Coelacanthimorpha). Second, multiple independent affinity divergence events recur in fishes, amphibians-reptiles, birds, and mammals. Third, high affinity phenotypes go up in mammals, possibly implying the rapid expansion of mammals might accelerate the evolution of coronaviruses. Fourth, we found natural mutations at eight amino acid sites of ACE2 can determine most of phenotype divergences of bonding affinity in 247 vertebrates and resolved their related structural basis. Moreover, we also identified high-affinity or low-affinity-associated concomitant mutation group.The group linked to extremely high affinity may provide novel potentials for the development of human recombinant soluble ACE2 (hrsACE2) in treating patients with COVID-19 or for constructing genetically modified SARS-CoV-2 infection models promoting vaccines studies. These findings would offer potential benefits for the treatment and prevention of SARS-CoV-2.

5.
Sci Prog ; 103(4): 36850420970367, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33225868

RESUMO

The piped hydraulic transportation of tube-contained raw material is a new low-carbon and environmental protection technique for transporting materials. The velocity characteristics of the spiral flow in the pipe with different numbers of guide bars installed on the surface of the piped vehicle body during piped hydraulic transportation of tube-contained raw material were studied by the theoretical analysis and model test. In the test, the numbers of guide bars placed on the surface of the piped vehicle body was respectively 3, 4, 5, and 6, and the studied sections were the section of the piped vehicle body and its rear section, and the flow discharge was 40 m3/h. The results showed that as the number of guide bars increased, the axial velocity of the section of the piped vehicle body increased gradually, while the axial velocity of the rear section of the piped vehicle reduced first and then increased. The section circumferential and radial flow velocity of the piped vehicle body and its rear section both increased first and then reduced. When the number of guide bars installed on the surface of the piped vehicle body was 4, the section circumferential flow velocity of the piped vehicle body and its rear section reached the maximum value, and their distributions were relatively uniform. The results offer theoretical basis so that we can optimize the structure of the piped vehicle and further popularize the piped hydraulic transportation technique of tube-contained raw material.

6.
iScience ; 23(10): 101606, 2020 Oct 23.
Artigo em Inglês | MEDLINE | ID: mdl-33205018

RESUMO

Efficient thermal energy harvesting using phase change materials (PCMs) has great potential for thermal energy storage and thermal management applications. Benefiting from these merits of pore structure diversity, convenient controllability, and excellent thermophysical stability, SiO2-based composite PCMs have comparatively shown more promising prospect. In this regard, the microstructure-thermal property correlation of SiO2-based composite PCMs is still unclear despite the significant achievements in structural design. To enrich the fundamental understanding on the correlations between the microstructure and the thermal properties, we systematically summarize the state-of-the-art advances in SiO2-based composite PCMs for tuning thermal energy storage from the perspective of tailoring chemistry strategies. In this review, the tailoring chemistry influences of surface functional groups, pore sizes, dopants, single shell, and hybrid shells on the thermal properties of SiO2-based composite PCMs are systematically summarized and discussed. This review aims to provide in-depth insights into the correlation between structural designs and thermal properties, thus showing better guides on the tailor-made construction of high-performance SiO2-based composite PCMs. Finally, the current challenges and future recommendations for the tailoring chemistry are also highlighted.

7.
Preprint | bioRxiv | ID: ppbiorxiv-376673

RESUMO

Olfactory dysfunction caused by SARS-CoV-2 infection represents as one of the most predictive and common symptoms in COVID-19 patients. However, the causal link between SARS-CoV-2 infection and olfactory disorders remains lacking. Herein we demonstrate intranasal inoculation of SARS-CoV-2 induces robust viral replication in the olfactory epithelium (OE), resulting in transient olfactory dysfunction in humanized ACE2 mice. The sustentacular cells and Bowmans gland cells in OE were identified as the major targets of SARS-CoV-2 before the invasion into olfactory sensory neurons. Remarkably, SARS-CoV-2 infection triggers cell death and immune cell infiltration, and impairs the uniformity of OE structure. Combined transcriptomic and proteomic analyses reveal the induction of antiviral and inflammatory responses, as well as the downregulation of olfactory receptors in OE from the infected animals. Overall, our mouse model recapitulates the olfactory dysfunction in COVID-19 patients, and provides critical clues to understand the physiological basis for extrapulmonary manifestations of COVID-19.

8.
Am J Trop Med Hyg ; 103(6): 2357-2367, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-33124537

RESUMO

The outbreak of COVID-19 quickly spread to 184 countries and regions around the world. It has drawn great attention from the WHO and was declared an international public health emergency on January 31, 2020. Because the population is generally susceptible to the virus, there are no effective drugs and vaccines, and active participation of the entire population in self-protection and self-isolation has become the key to cutting off transmission routes and effectively controlling the epidemic. A self-designed questionnaire to assess residents' knowledge, attitudes, and behaviors related to COVID-19 prevention and control used the Questionnaire Star service platform, and snowball sampling was used to invite rural residents to complete the questionnaire on WeChat. A total of 554 valid questionnaires were collected. Rural residents' average scores on knowledge, attitudes, and behaviors regarding prevention and control were 40 ± 7 (total of 50 points), 45 ± 3 (total of 52 points), and 92 ± 12 (total of 127 points), respectively. A lack of protective materials and weak awareness of prevention and control are the greatest difficulties and challenges experienced by rural residents during the epidemic. Accordingly, social support services, such as public transportation plans, supply chains for living materials, and orderly returns to work, need to be strengthened. Moreover, new infectious disease control is not only a task for individuals but also a global issue. It is of great significance to guarantee information transparency and enhance health risk communication.

9.
Appl Opt ; 59(23): 7092-7098, 2020 Aug 10.
Artigo em Inglês | MEDLINE | ID: mdl-32788804

RESUMO

IWe have designed, simulated, and experimentally tested a broadband metamaterial absorber loaded with lumped resistors in the microwave range. Compared with an electric resonator structure absorber, the composite absorber loaded with lumped resistors has stronger absorptivity over an extremely extended bandwidth. The simulated results show that an effective absorption bandwidth covers from 7.12 to 8.61 GHz with the absorption rate more than 90% under normal incidence. For oblique incidence, the proposed absorber displays an absorption rate above 90% from 7.55 to 8.61 GHz when the incident angle is below 35° for the transverse electric polarization. About the transverse magnetic polarization, the absorber displays larger than 90% absorptance from 7.24 to 8.61 GHz when the incident angle is below 70°. During the entire design process, the absorber structure is fabricated and measured. The measured results show that the absorptivity is above 90% in the frequency range of 6.78-7.65 GHz and 8.20-9.31 GHz under normal incidence. Furthermore, the absorption mechanism and absorption properties are further researched.

10.
Dose Response ; 18(3): 1559325820946914, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32821254

RESUMO

Background: Epilepsy is a chronic, complex, unprovoked, and recurrent disorder of the nervous system that affected several people worldwide. Phyllanthus amarus (PA) has been documented to have neuroprotective potential. Aim: To evaluate the potential of standardized extract of PA and its possible mechanism of action against the Pentylenetetrazol (PTZ)-induced convulsion and kindling associated post-ictal depression in experimental mice. Materials and Methods: Phyllathin was isolated from methanolic extract of PA and well-characterized using HPTLC, ESI-MS/MS, and LC/MS. Phyllathin containing a standardized extract of PA (50, 100, and 200 mg/kg) was administered in convulsed and kindled mice, followed by an assessment of various parameters. Results: The spectral analysis confirmed the molecular formula and weight of phyllanthin as C24H34O6 and 418.2342 Da. PA (100 and 200 mg/kg) significantly ameliorated PTZ-induced (p < 0.05) duration, onset of tonic-clonic convulsion, and mortality in mice. It also significantly attenuated (p < 0.05) PTZ-induced kindling in mice. Alteration in brain GABA, dopamine, and glutamate, Na+K+ATPase, Ca+2-ATPase activities, and oxido-nitrosative stress in kindled mice was significantly restored (p < 0.05) by PA treatment. It also significantly (p < 0.05) down-regulated brain mRNA expressions of NF-κB, TNF-α, IL-1ß, COX-2, and TLR-4. Histological aberrations induced by PTZ in the brain of a kindled rat was significantly (p < 0.05) ameliorated by PA. Conclusion: Phyllanthin containing a standardized extract of PA exerts its antiepileptic potential via balancing excitatory (glutamate) and inhibitory (GABA) brain monoamines, voltage-gated ion channels (Na+K+/Ca+2-ATPase) and inhibition of NF-κB/TLR-4 pathway to ameliorate neuroinflammation (TNF-α, IL-1ß, and COX-2) in experimental mice.

11.
Preprint | medRxiv | ID: ppmedrxiv-20158758

RESUMO

SARS-CoV-2 infects multiple organs including the respiratory tract and gut. Whether regional microbiomes are disturbed significantly to affect the disease progression of COVID-19 is largely unknown. To address this question, we performed cross-sectional and longitudinal analyses of throat and anal swabs from 35 COVID-19 adults and 15 controls by 16S rRNA gene sequencing. The results allowed a partitioning of patients into 3-4 categories (I-IV) with distinct microbial community types in both sites. Lower-diversity community types often appeared in the early phase of COVID-19, and synchronous fast restoration of both the respiratory and gut microbiomes from early dysbiosis towards late near-normal was observed in 6/8 mild COVID-19 adult patients despite they had a relatively slow clinical recovery. The synchronous shift of the community types was associated with significantly positive bacterial interactions between the respiratory tract and gut, possibly along the airway-gut axis. These findings reveal previously unknown interactions between respiratory and gut microbiomes, and suggest that modulations of regional microbiota might help to improve the recovery from COVID-19 in adult patients.

12.
Preprint | medRxiv | ID: ppmedrxiv-20152181

RESUMO

Children are less susceptible to COVID-19 and manifests lower morbidity and mortality after infection, for which a multitude of mechanisms may be proposed. Whether the normal development of gut-airway microbiome is affected by COVID-19 has not been evaluated. We demonstrate that COVID-19 alters the respiratory and gut microbiome of children. Alteration of the microbiome was divergent between the respiratory tract and gut, albeit the dysbiosis was dominated by genus Pseudomonas and sustained for up to 25-58 days in different individuals. The respiratory microbiome distortion persisted in 7/8 children for at least 19-24 days after discharge from the hospital. The gut microbiota showed early dysbiosis towards later restoration in some children, but not others. Disturbed development of both gut and respiratory microbiomes, and prolonged respiratory dysbiosis in children imply possible long-term complications after clinical recovery from COVID-19, such as predisposition to an increased health risk in the post-COVID-19 era.

13.
Preprint | medRxiv | ID: ppmedrxiv-20126607

RESUMO

The COVID-19 pandemic has accounted for more than five million infections and hundreds of thousand deaths worldwide in the past six months. The patients demonstrate a great diversity in clinical and laboratory manifestations and disease severity. Nonetheless, little is known about the host genetic contribution to the observed inter-individual phenotypic variability. Here, we report the first host genetic study in China by deeply sequencing and analyzing 332 COVID-19 patients categorized by varying levels of severity from the Shenzhen Third Peoples Hospital. Upon a total of 22.2 million genetic variants, we conducted both single-variant and gene-based association tests among five severity groups including asymptomatic, mild, moderate, severe and critical ill patients after the correction of potential confounding factors. The most significant gene locus associated with severity is located in TMEM189-UBE2V1 involved in the IL-1 signaling pathway. The p.Val197Met missense variant that affects the stability of the TMPRSS2 protein displays a decreasing allele frequency among the severe patients compared to the mild and the general population. We also identified that the HLA-A*11:01, B*51:01 and C*14:02 alleles significantly predispose the worst outcome of the patients. This initial study of Chinese patients provides a comprehensive view of the genetic difference among the COVID-19 patient groups and highlighted genes and variants that may help guide targeted efforts in containing the outbreak. Limitations and advantages of the study were also reviewed to guide future international efforts on elucidating the genetic architecture of host-pathogen interaction for COVID-19 and other infectious and complex diseases.

14.
Artigo em Inglês | MEDLINE | ID: mdl-32357821

RESUMO

Autophagy is defined as separation and degradation of cytoplasmic components through autophagosomes, which plays an essential part in physiological and pathological events. Thence it is also essential for cellular homeostasis. Autophagy disorder may bring about the failure of stem cells to maintain the fundamental transformation and metabolism of cell components. However, for cancer cells, the disorder of autophagy is a feasible antitumor idea. Nanoparticles, referring to particles of the size range 1-100 nanometers, are appearing as a category of autophagy regulators. These nanoparticles may revolutionize and broaden the therapeutic strategies of many diseases, including neurodegenerative diseases, tumors, muscle disease, and so on. Researches of autophagyinduced nanomaterials mainly focus on silver particles, gold particles, silicon particles, and rare earth oxides. But in recent years, more and more materials have been found to regulate autophagy, such as nano-nucleic acid materials, nanofiber scaffolds, quantum dots, and so on. The review highlights that various kinds of nanoparticles have the power to regulate autophagy intensity in stem cells of interest and further control biological behaviors, which may become a reliable treatment choice for disease therapy.

15.
Artigo em Inglês | MEDLINE | ID: mdl-32454856

RESUMO

Aim: To investigate the mechanisms of Fuzheng Huayu (FZHY) Capsule in the treatment of hepatitis B (HBV)- associated fibrosis, HBV patients were divided into two groups, 50 cases were in the nucleotide analogues (NAs) group, while additional 50 cases were in the NAs + FZHY group. Methods: We assessed the curative effects of antifibrosis through liver function, FibroScan test, and liver biopsy and detected the ratio of lymphocyte subsets by flow cytometry. Peripheral blood lymphocyte and CD8+T, CD4+T, and natural killer cell subsets collected from patients were cocultured with LX-2 cells. Activation of LX-2 cells, production of the extracellular matrix, apoptosis, and proliferation of LX-2 cells were determined. Chronic liver injury models were established by ConA treatment. Results: It is evident that FZHY treatment significantly increased the percentage of NK cells, the rate of death, and apoptosis of LX-2 cells and decreased the FibroScan liver stiffness measurement value. The expressions of α-SMA and procollagen type I mRNA in LX-2 cells of the FZHY treatment group as downregulated when they were cocultured with lymphocytes compared to those from the NAs group. The proliferation of LX-2 cells in the FZHY treatment group was inhibited compared to that in the NAs group. In a mouse model of hepatic fibrosis, PBLs and IHLs from ConA exposure plus FZHY treatment inhibited the ability of JS-1 cells to express α-SMA. Conclusions: FZHY Capsule improved the disordered cellular immunity and postponed liver fibrosis possibly through inhibiting the interaction between lymphocyte and hepatic stellate cells.

16.
Panminerva Med ; 2020 Apr 28.
Artigo em Inglês | MEDLINE | ID: mdl-32343508

RESUMO

BACKGROUND: Recently, microRNA-99b (miR-99b) shows diverse functions in different human disease. However, further studies about the potential effect of miR-99b in cerebral ischemia injury still need to be done. METHODS: The expressions of miR-99b and IGF1R were detected via RT-qPCR assay. Western blot assay was applied to measure the protein expression of Caspase-3, Bax and Bcl-2. MTT assay was used to observe cell viability of SH-SY5Y cells. The association of miR-99b and IGF1R was testified by dual luciferase assay. And human SH-SY5Y cells were treated with the oxygen-glucose deprivation / reperfusion (OGD/R) to mimic CIR injury. RESULTS: The expression of miR-99b was increased in the OGD/R model. And upregulation of miR-99b promoted cell viability and inhibited apoptosis induced by OGD/R. Moreover, IGF1R was confirmed as a direct target gene of miR-99b. The expression of IGF1R was obviously decreased under OGD/R conditions. CONCLUSIONS: MiR-99b promoted the viability and suppressed apoptosis of SH-SY5Y cells under OGD/R conditions through targeting IGF1R.

17.
BMC Pulm Med ; 20(1): 101, 2020 Apr 23.
Artigo em Inglês | MEDLINE | ID: mdl-32326931

RESUMO

BACKGROUND: Patients with bronchiectasis have a higher cardiovascular risk than their matched controls. However, the effect of cardiovascular (CV) disease on bronchiectasis remains unclear. Thus, we aimed to investigate the clinical impacts of cardiovascular disease on adult patients with bronchiectasis. METHODS: The study cohort comprised 603 consecutive inpatients diagnosed with bronchiectasis in the Affiliated Yancheng Hospital of Southeast University Medical College (Jiangsu, China) from January 2014 to December 2017. Symptoms, bacterial cultures, blood biochemical indicator levels, and chest high-resolution computed tomography scans were assessed during their initial hospitalization for bronchiectasis. Three hundred and thirty five subjects finished 1 year follow-up after their hospital discharge. RESULTS: Three hundred thirty five patients had at least one bronchiectasis exacerbation during the 1-year follow-up period. Patients with CV comorbidities were more likely to present with symptoms of wheezing (65.3%) and had a higher levels of brain natriuretic peptide (P < 0.001) and D-dimer (P < 0.001) than those without CV comorbidities. Independent risk factors associated with bronchiectasis exacerbations were the presence of comorbidities of cardiovascular diseases (odds ratio [OR] 2.503, 95% confidence interval [CI] 1.298-4.823; P = 0.006), the isolation of Pseudomonas aeruginosa (OR 2.076, 95% CI 1.100-3.919; P = 0.024), and extension to more than two lobes (OR 2.485, 95% CI 1.195-5.168; P = 0.015). CONCLUSION: The existence of cardiovascular disease was independently associated with increased bronchiectasis exacerbation.

18.
World Neurosurg ; 139: 608-613, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32298835

RESUMO

BACKGROUND: Brucellosis is an endemic disease. Brucellar spondylitis is mainly manifested as a unifocal lesion, but noncontiguous multifocal brucellar spondylitis is more rare. CASE DESCRIPTION: Herein, we report 3 patients with noncontiguous multifocal involvement of brucellar spondylitis who are over 51 years of age. The diagnosis was established by using magnetic resonance imaging (MRI) and positive brucellar agglutination test. All patients were cured with antibrucellosis chemotherapy and surgery. For patients with a high degree of suspicion of noncontiguous multifocal brucellar spondylitis, especially elderly patients, screening with the use of serologic test for brucellosis and whole spine MRI is crucial to reduce the rate of misdiagnosis and missed diagnosis. CONCLUSIONS: Clinicians should raise awareness of noncontiguous multifocal brucellar spondylitis. The Wright agglutination test and whole spine MRI are the key methods to reduce misdiagnosis and missed diagnosis of noncontiguous multifocal brucellar spondylitis. Drug therapy for brucellar spondylitis is the basis, and surgical treatment is complementary therapy. The use of alternative chemotherapy and surgery for noncontiguous multifocal brucellar spondylitis is also safe and effective.


Assuntos
Brucelose/cirurgia , Vértebras Lombares/cirurgia , Espondilite/cirurgia , Vértebras Torácicas/cirurgia , Brucelose/complicações , Brucelose/diagnóstico por imagem , Feminino , Humanos , Vértebras Lombares/diagnóstico por imagem , Masculino , Pessoa de Meia-Idade , Espondilite/complicações , Espondilite/diagnóstico por imagem , Vértebras Torácicas/diagnóstico por imagem
20.
Preprint | bioRxiv | ID: ppbiorxiv-049643

RESUMO

The infection of the novel coronavirus SARS-CoV-2 have caused more than 150,000 deaths, but no vaccine or specific therapeutic antibody is currently available. SARS-CoV-2 relies on its spike protein, in particular the receptor binding domain (RBD), to bind human cell receptor angiotensin-converting enzyme 2 (ACE2) for viral entry, and thus targeting RBD holds the promise for preventing SARS-CoV-2 infection. In this work, a competitive biopanning strategy of a phage display antibody library was applied to screen blocking antibodies against RBD. High-affinity antibodies were enriched after the first round using a standard panning process in which RBD-His recombinant protein was immobilized as a bait. At the next two rounds, immobilized ACE2-Fc and free RBD-His proteins were mixed with the enriched phage antibodies. Antibodies binding to RBD at epitopes different from ACE2-binding site were captured by the immobilized ACE2-Fc, forming a "sandwich" complex. Only antibodies competed with ACE2 for recognizing RBD at the same or similar epitopes can bind to the free RBD-His in the supernatant and be subsequently separated by the Ni-NTA magnetic beads. Top 1 lead from the competitive biopanning of a synthetic antibody library, Lib AB1, was produced as the full-length IgG1 format. It was proved to competitively block the binding of RBD to ACE2 protein, and potently inhibit SARS-CoV-2 pseudovirus infection of ACE2-overexpressing Hela cells with IC50 values of 12nM. Nevertheless, top 1 lead from the standard biopanning of Lib AB1, can only bind to RBD in vitro but not have the blocking or neutralization activity. Our strategy can efficiently isolate the blocking antibodies of RBD, and it would speed up the discovery of neutralizing antibodies against SARS-CoV-2.

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