The study analysed healthcare workers' (HCWs) knowledge, practices, and attitudes regarding coronavirus disease 2019 . A cross-sectional survey was conducted from February 4 th to February 8 th , 2020, involving a total of 1357 HCWs across 10 hospitals in Henan, China. Of those surveyed, 89% of HCWs had sufficient knowledge of COVID-19, more than 85% feared self-infection with the virus, and 89.7% followed correct practices regarding COVID-19. In addition to knowledge level, some risk factors including work experience and job category influenced HCWs' attitudes and practice concerning COVID-19. Measures must be taken to protect HCWs from risks linked to job category, work experience, working hours, educational attainment, and frontline HCWs.

This paper studies the preview control problem for continuous-time control systems. A design method for an optimal preview controller is presented, when the desired tracking and disturbance are piecewise-continuously differentiable functions. Applying the same techniques as for optimal control in linear quadratic optimal control, we derive a type-one servomechanism with both desired tracking preview and disturbance preview compensation. A proof is presented that if the original system is stabilizable and detectable, the closed-loop system is asymptotically stable. We also design a full-dimensional state observer for the considered system. Finally, numerical simulations show the efficiency of the controller.

P2X7 is important in inflammation and tissue injury. The aim of the present study was to investigate the effect of P2X7 inhibition, using a specific inhibitor (A438079) to prevent the development of liver injury and fibrosis in a mouse model of liver fibrosis. The mouse liver fibrosis model was induced by carbon tetrachloride (CCl4). Mice received subcutaneous administration of vehicle (saline/olive oil), CCl4 or subcutaneous CCl4 and A438079. The pro‑inflammatory and pro‑fibrotic factors were determined by western blot analysis. The biochemistry, histopathology, collagen deposition and nuclear factor‑κB (NF‑κB) activity were also analyzed. Chronic CCl4 treatment resulted in liver injury and collagen accumulation. The expression levels of P2X7, pro‑inflammatory and pro‑fibrotic mediators, and the activity of NF‑κB were markedly increased. Treatment with A438079 significantly inhibited CCl4‑induced P2X7 expression, and attenuated CCl4‑induced liver injury and the inflammatory response. P2X7 blockade also significantly reduced the formation of collagen in the liver and the expression of α-smooth muscle actin and transforming growth factor‑β1. This study demonstrated that P2X7 inhibition attenuated liver injury and fibrosis in a mouse model. Thus, P2X7 is a potential novel therapeutic target for liver injury and fibrosis.

Purpose: Evidence suggests that the majority of colorectal carcinomas arise from adenomas, and L-arginine suppresses colorectal tumorigenesis. We suppose that L-arginine may inhibit the process of carcinogenesis from colorectal adenoma to adenocarcinoma. The aim of this study was to investigate the effects of L-arginine on the formation and development of colorectal tumors. Experimental Design: We selected 60 patients with colorectal cancer and 60 patients with colorectal adenoma (CRA) and divided them into four groups of 30 patients each.We gave 30 g (120 mL) of L-arginine everyday for 3 days to the test groups, whereas L-arginine was substituted by 5% glucose in the control groups. The expression of the proliferating cell nuclear antigen, survivin, and nitric oxide synthase was examined immunohistochemically, and ornithine decarboxylase (ODC) activity was examined spectrophotometrically. Serum nitric oxide (NO) was detected by the Griess assay. Results: In patients with CRA, the proliferating cell nuclear antigen and survivin labeling indexes and ODC activity of the tumor and paratumor mucosa in the L-arginine^treated group after L-arginine treatment were significantly lower as compared with the corresponding pretreatment values (P < 0.01). Moreover, inducible nitric oxide synthase expression in the tumor markedly increased after L-arginine treatment (P < 0.05). Serum NO levels in the patients with colorectal cancer were markedly higher than those in the patients with CRA, and L-arginine treatment was responsible for this increase (P < 0.05). Conclusions:Our results show that L-arginine can restrain crypt cell hyperproliferation and the expression of survivin, an inhibitor of apoptosis protein. This suggests that L-arginine can block the formation and development of colorectal tumors, and this effect might be related to the increased serum NO concentration and decreased ODC activity.Colorectal carcinoma (CRC) is one of the most common cancers in the world, and colorectal adenoma (CRA) is known to be a precursor of both sporadic and hereditary CRC. Recent studies have shown that the frequency of adenomas in a population with an increased risk of CRC is higher as compared with that in the general population; moreover, patients with the so-called hereditary nonpolyposis syndrome also had an earlier onset of adenomas and faster progression to cancer (1). It is widely accepted that environmental factors, particularly dietary factors, are involved in the etiology of CRC. A high intake of fat, red meat, and energy have not only been associated with an increased risk of CRC (2 -5), but have also influenced the 5-year survival in the patients who underwent surgical treatment for CRC (6). Therefore, developing strategies to decrease the incidence of CRC and improve its prognosis by changing the diet or certain dietary components have currently become a hot topic of study. The focus on L-arginine supplements has been increasing in recent years.L-Arginine, a semiessential amino acid, is required for the synthesis...

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