Deciphering the dynamic changes in antibodies against SARS-CoV-2 is essential for understanding the immune response in COVID-19 patients. Here we analyze the laboratory findings of 1,850 patients to describe the dynamic changes of the total antibody, spike protein (S)-, receptor-binding domain (RBD)-, and nucleoprotein (N)-specific immunoglobulin M (IgM) and G (IgG) levels during SARS-CoV-2 infection and recovery. The generation of S-, RBD-, and N-specific IgG occurs one week later in patients with severe/critical COVID-19 compared to patients with mild/moderate disease, while S- and RBD-specific IgG levels are 1.5-fold higher in severe/critical patients during hospitalization. The RBD-specific IgG levels are 4-fold higher in older patients than in younger patients during hospitalization. In addition, the S- and RBD-specific IgG levels are 2-fold higher in the recovered patients who are SARS-CoV-2 RNA negative than those who are RNA positive. Lower S-, RBD-, and N-specific IgG levels are associated with a lower lymphocyte percentage, higher neutrophil percentage, and a longer duration of viral shedding. Patients with low antibody levels on discharge might thereby have a high chance of being tested positive for SARS-CoV-2 RNA after recovery. Our study provides important information for COVID-19 diagnosis, treatment, and vaccine development.

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Coronavirus disease 2019 (COVID-19) is causing worldwide pandemic with no specific therapeutic agents, especially for severe or critical patients. To comprehensively evaluate the effectiveness, safety, and indications of convalescent plasma transfusion (CPT) therapy for severe or critical COVID-19 patients, we analyzed the clinical, laboratory, and radiologic characteristics of 1,568 patients from a single center, in which 138 patients received ABO-compatible CPT. The median time from the first symptom to CPT was 45 days. 2.2% and 4.1% of cases died in the CPT group and in the standard-treatment group, respectively. 2.4% and 5.1% of patients in the CPT and the standard-treatment group have been admitted to ICU eventually. 70% of the patients who had severe respiratory symptoms got improved and removed oxygen supports within 7 days after CPT. The viral loads and C-reactive protein (CRP) concentration significantly decreased (P<0.001), and the percentage of lymphocytes increased (P=0.006), 76.8% of cases received radiological improvements within 14 days after CPT. Patients with a higher percentage of lymphocytes and a lower percentage of neutrophils and CRP concentration respond better to CPT (P<0.05). Notably, for the patients who received CPT within 7 weeks after symptom onset, the median time from CPT to clinical improvements was approximately 10 days. But the time to clinical improvements was significantly prolonged for patients who received CPT later than 7 weeks after onset. Our study will provide important information for the clinical practice in COVID-19 treatment, as well as provide real-world observations and clinical data for the development of monoclonal antibodies.

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Elsevier has created a COVID-19 resource centre with free information in English and Mandarin on the novel coronavirus COVID-19. The COVID-19 resource centre is hosted on Elsevier Connect, the company's public news and information website. Elsevier hereby grants permission to make all its COVID-19-related research that is available on the COVID-19 resource centre-including this research content-immediately available in PubMed Central and other publicly funded repositories, such as the WHO COVID database with rights for unrestricted research re-use and analyses in any form or by any means with acknowledgement of the original source. These permissions are granted for free by Elsevier for as long as the COVID-19 resource centre remains active.

Aims:Corona virus disease 2019 has rapidly become the most severe public health issue all over the world. Despite respiratory symptoms, hepatic injury has also been observed in clinical settings. This study aimed to investigate the risk factors involved with hepatic injury in the patients with COVID-19.Methods: A total of 85 hospitalized patients who were diagnosed with COVID-19 in Beijing You'an Hospital were retrospectively analyzed. According to liver function, they were divided into ALT normal group (n=52) and ALT elevation group (n=33).Clinical features and laboratory data were compared between the two groups. The independent risk factors for liver injury were analyzed.Results: There were 33 patients with hepatic injury in our study, accounting for 38.8%(33/85). The patients in ALT elevation group were older than those in ALT normal group. The levels of lactic acid, CRP, myoglobin, and neutrophils were significantly higher in ALT elevation group. The lymphocytes and albumin were significantly lower in ALT elevation group. The proportion of severe and critical patients in ALT elevation group was significantly higher. Multivariate logistic regression analysis showed CRP ≥ 20 mg/L and lymphocyte count< 1.1×10^9/L were independently related to hepatic injury. Conclusions:Lymphopenia and CRP may serve as the risk factors related to hepatic injury in patients with COVID-19, which might be related to inflammatory cytokine storm in liver injury. Early detection and timely treatment of hepatic injury in patients with COVID-19 are necessary.

Complete body of DFT-MD results, results of Monte Carlo simulations, setup and results of microkinetic modeling, additional experimental details and results (PDF) CatMAP files (ZIP) ■ AUTHOR INFORMATION

Spiders achieve superior silk fibres by controlling the molecular assembly of silk proteins and the hierarchical structure of fibres. However, current wet-spinning process for recombinant spidroins oversimplifies the natural spinning process. Here, water-soluble recombinant spider dragline silk protein (with a low molecular weight of 47 kDa) was adopted to prepare aqueous spinning dope. Artificial spider silks were spun via microfluidic wet-spinning, using a continuous post-spin drawing process (WS-PSD). By mimicking the natural spinning apparatus, shearing and elongational sections were integrated in the microfluidic spinning chip to induce assembly, orientation of spidroins, and fibril structure formation. The additional post-spin drawing process following the wet-spinning section partially mimics the spinning process of natural spider silk and substantially contributes to the compact aggregation of microfibrils. Subsequent post-stretching further improves the hierarchical structure of the fibres, including the crystalline structure, orientation, and fibril melting. The tensile strength and elongation of post-treated fibres reached up to 510 MPa and 15%, respectively.