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Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the causative agent for coronavirus 2019 (COVID-19) pneumonia. Little is known about the kinetics, tissue distribution, cross-reactivity, and neutralization antibody response in patients with COVID-19. Two groups of patients with RT-PCR-confirmed COVID-19 were enrolled in this study: 12 severely ill patients in intensive care units who needed mechanical ventilation and 11 mildly ill patients in isolation wards. Serial clinical samples were collected for laboratory detection. Results showed that most of the severely ill patients had viral shedding in a variety of tissues for 20-40 days after onset of disease (8/12, 66.7%), while the majority of mildly ill patients had viral shedding restricted to the respiratory tract and had no detectable virus RNA 10 days after onset (9/11, 81.8%). Mildly ill patients showed significantly lower IgM response compared with that of the severe group. IgG responses were detected in most patients in both the severe and mild groups at 9 days after onset, and remained at a high level throughout the study. Antibodies cross-reactive to SARS-CoV and SARS-CoV-2 were detected in patients with COVID-19 but not in patients with MERS. High levels of neutralizing antibodies were induced after about 10 days after onset in both severely and mildly ill patients which were higher in the severe group. SARS-CoV-2 pseudotype neutralization test and focus reduction neutralization test with authentic virus showed consistent results. Sera from patients with COVID-19 inhibited SARS-CoV-2 entry. Sera from convalescent patients with SARS or Middle East respiratory syndrome (MERS) did not. Anti-SARS-CoV-2 S and N IgG levels exhibited a moderate correlation with neutralization titers in patients' plasma. This study improves our understanding of immune response in humans after SARS-CoV-2 infection., Introduction Before November 2019, 6 coronaviruses (CoVs) were known to infect humans and cause respiratory disease: OC43, 229E, HKU1, and NL63, 4 community-acquired CoVs that are endemic in humans (1-4), [...]

In this work, ambient pressure X-ray photoelectron spectroscopy (APXPS) was used to investigate the effect of oxygen adsorption on the band bending and electron affinity of Al2O3, ZnO and TiO2 ultrathin films (∼1 nm in thickness) deposited on a Si substrate by atomic layer deposition (ALD). Upon exposure to oxygen at room temperature (RT), upward band bending was observed on all three samples, and a decrease in electron affinity was observed on Al2O3 and ZnO ultrathin films at RT. At 80 °C, the magnitude of the upward band bending decreased, and the change in the electron affinity vanished. These results indicate the existence of two surface oxygen species: a negatively charged species that is strongly adsorbed and responsible for the observed upward band bending, and a weakly adsorbed species that is polarized, lowering the electron affinity. Based on the extent of upward band bending on the three samples, the surface coverage of the strongly adsorbed species exhibits the following order: Al2O3 > ZnO > TiO2. This finding is in stark contrast to the trend expected on the surface of these bulk oxides, and highlights the unique surface activity of ultrathin oxide films with important implications, for example, in oxidation reactions taking place on these films or in catalyst systems where such oxides are used as a support material.

Author(s): Haibo Zhang [sup.1] [sup.3] [sup.6], Josef M. Penninger [sup.4] [sup.5], Yimin Li [sup.3], Nanshan Zhong [sup.3], Arthur S. Slutsky [sup.1] [sup.2] [sup.3] Author Affiliations: (1) grid.415502.7, The Keenan Research [...]

This paper reported a micro flow cytometer capable of high‐throughput characterization of single‐cell electrical and structural features based on constrictional microchannels and deep neural networks. When single cells traveled through microchannels with constricted cross‐sectional areas, they effectively blocked concentrated electric field lines, producing large impedance variations. Meanwhile, the traveling cells were confined within the cross‐sectional areas of the constrictional microchannels, enabling the capture of high‐quality images without losing focuses. Then single‐cell features from impedance profiles and optical images were extracted from customized recurrent and convolution networks (RNN and CNN), which were further fused for cell‐type classification based on support vector machines (SVM). As a demonstration, two leukemia cell lines (e.g., HL60 vs. Jurkat) were analyzed, producing high‐classification accuracies of 99.3% based on electrical features extracted from Long Short‐Term Memory (LSTM) of RNN, 96.7% based on structural features extracted from Resnet18 of CNN and 100.0% based on combined features enabled by SVM. The microfluidic flow cytometry developed in this study may provide a new perspective for the field of single‐cell analysis. [ABSTRACT FROM AUTHOR]

Since the coronavirus disease 2019 (COVID‐19) was identified in 2019, it has caused more than 664 million confirmed cases and more than 6.7 million deaths globally by January 20, 2023. So far, the novel coronavirus has undergone mutations from the original, Alpha, Delta, and Omicron strains. Omicron was first detected in South Africa in November 2021 and has since spread rapidly to more than 100 countries around the world, leading the World Health Organization (WHO) to classify it as a "variant of concern" for COVID‐19. Due to its stronger infectivity, faster transmission, and higher reinfection rate, it is more likely to cause immune evasion and infection breakthrough in the vaccinated population. Omicron has replaced Delta strain as the main epidemic strain imported from overseas and in China. People with immunodeficiency are more susceptible to the novel coronavirus due to abnormal immune function, and viral infections tend to be more lasting and severe. In addition, due to the existence of underlying diseases, most people with immunodeficiency have been taking immunosuppressants and other related drugs for a long time, and there are different degrees of interaction between novel coronavirus treatment drugs and original drugs, which brings great challenges to the diagnosis and treatment of people with immunodeficiency after infection with novel coronavirus. According to the Novel Coronavirus Infection Diagnosis and Treatment Protocol (Trial 10th Edition) issued by the National Health Commission, which emphasizes "strengthening the protection of key groups," people with immune deficiency belong to the high‐risk groups of severe or critical disease. Based on the evidence of evidence‐based medicine and after many discussions by experts from multiple disciplines (Department of Respiratory and Critical Care, Department of Organ Transplantation, Department of Rheumatology, Department of Hematology, Department of Infection, Department of Critical Care Medicine, etc.), 13 recommendations are summarized to provide theoretical and practical reference for the diagnosis and treatment strategy of this special population. [ABSTRACT FROM AUTHOR]

Introduction: The discovery of longevity molecules that delay aging and prolong lifespan has always been a dream of humanity. Sitagliptin phosphate (SIT), an oral dipeptidyl peptidase-4 (DPP-4) inhibitor, is an oral drug commonly used in the treatment of type 2 diabetes (T2D). In addition to being antidiabetic, previous studies have reported that SIT has shown potential to improve health. However, whether SIT plays a role in the amelioration of aging and the underlying molecular mechanism remain undetermined. Methods:Caenorhabditis elegans (C. elegans) was used as a model of aging. Lifespan assays were performed with adult-stage worms on nematode growth medium plates containing FUdR with or without the specific concentration of SIT. The period of fast body movement, body bending rates, and pharyngeal pumping rates were recorded to assess the healthspan of C. elegans. Gene expression was confirmed by GFP fluorescence signal of transgenic worms and qPCR. In addition, the intracellular reactive oxygen species levels were measured using a free radical sensor H2DCF-DA. Results: We found that SIT significantly extended lifespan and healthspan of C. elegans. Mechanistically, we found that several age-related pathways and genes were involved in SIT-induced lifespan extension. The transcription factors DAF-16/FOXO, SKN-1/NRF2, and HSF-1 played important roles in SIT-induced longevity. Moreover, our findings illustrated that SIT-induced survival benefits by inhibiting the insulin/insulin-like signaling pathway and activating the dietary restriction-related and mitochondrial function-related signaling pathways. Conclusion: Our work may provide a theoretical basis for the development of anti-T2D drugs as antiaging drugs, especially for the treatment of age-related disease in diabetic patients. [ABSTRACT FROM AUTHOR]