[Vertical Migration Characteristics and Fate of Heavy Metals from Zinc Smelting Slag in Soil Profile].

To investigate the influence of heavy metals in smelting waste residue on the quality of soil and groundwater, a simulation column experiment was conducted to study the migration characteristics of heavy metals from the leaching solution of zinc volatilizing kiln residue in the site soil profile under continuous or intermittent leaching for 90 days. The concentrations of Cd, Cu, Pb, and Zn in leachate and their accumulation, chemical fractions, and particle size distribution characteristics in the soil profile were analyzed, and the retention mechanism of heavy metals was also discussed. The results showed that the concentration of heavy metals in the soil column leachate decreased rapidly after reaching the peak at the earlier leaching stage, and the Cd concentration far exceeded the threshold limit of 0.1 mg·L-1(class Ⅳ) of the Quality Standard for Groundwater(GB/T 14848-2017), indicating that there was Cd pollution risk of groundwater. The soil profile had a great adsorption capacity for heavy metals in the waste residue. Cd, Cu, Pb, and Zn were predominately accumulated in the shallow soil depth(0-10 cm), which was 237-429, 1.25-16.2, 1.38-2.31, and 1.79-3.17 times of the content of corresponding heavy metals in the soil profile before leaching, respectively. The migration distance of heavy metals in the slag under continuous leaching was longer than that under intermittent leaching, and Cd was significantly accumulated in the deep layer of the soil column. The contribution of soil coarse particles(0.5-2.0 mm) to the total cumulative amount of Cd, Cu, and Zn was larger, whereas Pb was more prone to accumulate in the particle size of<0.25 mm. The results of BCR sequential extraction fraction showed that the accumulated Cd, Cu, and Zn in shallow soil depth were mainly present in the weak acid extraction, accounting for 62.4%-76.7%, 72.0%-95.8%, and 67.6%-85.8% of total content, respectively. The X-ray diffraction(XRD) and Fourier transform infrared spectroscopy(FTIR) analysis showed that exogenous heavy metals in slag entering the soil would not form a stable mineral phase within 90 days, and the soil hydroxyl(-OH) and carbonyl(C=O) functional groups and iron aluminum silicate oxides were the main retention factors.

Isolation and Screening of High-Yielding α-Amylase Mutants of Bacillus subtilis by Heavy Ion Mutagenesis.

To improve fermentative production of α-amylase, heavy-ion mutagenesis technology was used to irradiate Bacillus subtilis (B. subtilis) to obtain the high yielding mutants in this study. After continuous cultivation for 12 generations, eight mutants exhibited positive mutation rate with greater H/C. The α-amylase production was stable and obviously exceeded that by the parent strain, which shows that the mutants have a good genetic stability. Among the mutants, the α-amylase activity of B. subtilis KC-180-2 was 72.26 U·mL-1, which was 82.34% higher than that of the original strain. After optimization of fermentation conditions and media, the α-amylase activity of B. subtilis KC-180-2 reached a maximum of 156.83 U·mL-1 at 36 h in a bioreactor. In addition, the optimized fermentation temperature of B. subtilis KC-180-2 was increased to 49℃, indicating B. subtilis KC-180-2 possesses high-temperature resistance, which has great application prospects for industrial fermentation for α-amylase production.

Case report: Quadruple primary malignant neoplasms including esophageal, ureteral, and lung in an elderly male.

Multiple primary malignant neoplasms (MPMNs) are defined as multiple tumors with different pathogenic origins. MPMNs are rare, but the morbidity rate is on the rise. With the development of anti-tumor treatments, such as targeted therapy and immunotherapy, the overall survival of cancer patients has been significantly prolonged, leading to an increased number of patients with MPMNs. A crucial aspect of MPMNs management is deciding how to schedule further treatments according to individual tumor risk. This process involves a multidisciplinary physician team to ensure favorable outcomes. Herein we report a 60-year-old male who developed four different malignancies, including esophageal squamous cell carcinoma, upper urinary tract urothelial carcinoma, mediastinal small cell lung cancer, and left lung squamous cell carcinoma over 20 years and received appropriate treatment of each cancer with long survival.

Overexpression of enzymes in glycolysis and energy metabolic pathways to enhance coenzyme Q10 production in Rhodobacter sphaeroides VK-2-3.

We subjected the components of the glycolysis and energy metabolism pathways of Rhodobacter sphaeroides (R. sphaeroides) to metabolic engineering to improve the titer and yield of coenzyme Q10 (CoQ10). Phosphofructokinase (PFK), cyclic adenylate-dependent protein kinase (PKAC), glyceraldehyde-3-phosphate dehydrogenase (GAPDH), and adenosine triphosphate hydrolase (KdpC) were overexpressed in R. sphaeroides VK-2-3 (VK-2-3). The strains were labeled R. sphaeroides PFK (RS.PFK), RS.PKAC, RS.PFK-PKAC, RS.KdpC, RS.GAPDH, and RS.KdpC-GAPDH. Results showed that the CoQ10 titers of RS.PFK, RS.PKAC, and RS.PFK-PKAC were 300.96 ± 0.87, 405.94 ± 4.77, and 379.94 ± 0.42 mg/l, respectively. The CoQ10 titers of RS.PFK and VK-2-3 were not significantly different; however, those for RS.PKAC and RS.PFK-PKAC were 13 and 6% higher than that of VK-2-3, respectively. Further, the titers of RS.KdpC, RS.GAPDH, and RS.KdpC-GAPDH were 360.17 ± 0.39, 409.79 ± 0.76, and 359.87 ± 1.14 mg/l, respectively. The titers of RS.KdpC and RS.KdpC-GAPDH were not significantly different from that for VK-2-3, whereas that for RS.GAPDH was 14% higher than that of VK-2-3. Finally, when the cultures of RS.GAPDH and VK-2-3 were scaled up in 5-L fermenters, the CoQ10 titers and RS.GAPDH yields increased by 44.3 and 37.8%, respectively, compared with VK-2-3.To the best of our knowledge, the glycolysis pathway of R. sphaeroides was studied for the first time in this study. We genetically modified the components of the energy metabolism pathway to obtain the strain with high yield of CoQ10 mutant RS.GAPDH. The findings of this study can serve as a basis for future studies involving metabolic engineering of CoQ10-producing strains.

Surgical timing for primary encapsulating peritoneal sclerosis: A case report and review of literature.

BACKGROUND: Primary encapsulating peritoneal sclerosis (EPS) is a rare but devastating disease that causes fibrocollagenous cocoon-like encapsulation of the bowel, resulting in bowel obstruction. The pathogenesis, prevention, and treatment strategies of EPS remain unclear so far. Since most patients are diagnosed during exploratory laparotomy, for the non-surgically diagnosed patients with primary EPS, the surgical timing is also uncertain. CASE SUMMARY: A 44-year-old female patient was referred to our center on September 6, 2021, with complaints of abdominal distention and bilious vomiting for 2 d. Physical examination revealed that the vital signs were stable, and the abdomen was slightly distended. Computerized tomography scan showed a conglomerate of multiple intestinal loops encapsulated in a thick sac-like membrane, which was surrounded by abdominal ascites. The patient was diagnosed with idiopathic EPS. Recovery was observed after abdominal paracentesis, and the patient was discharged on September 13 after the resumption of a normal diet. This case raised a question: When should an exploratory laparotomy be performed on patients who are non-surgically diagnosed with EPS. As a result, we conducted a review of the literature on the clinical manifestations, intraoperative findings, surgical methods, and therapeutic effects of EPS. CONCLUSION: Recurrent intestinal obstructions and abdominal mass combined with the imaging of encapsulated bowel are helpful in diagnosing idiopathic EPS. Small intestinal resection should be avoided.

Phosphoglycerate kinase 1 silencing by a novel microRNA microRNA-4523 protects human osteoblasts from dexamethasone through activation of Nrf2 signaling cascade.

Nuclear-factor-E2-related factor 2 (Nrf2) cascade activation can ameliorate dexamethasone (DEX)-induced oxidative injury and death in human osteoblasts. Phosphoglycerate kinase 1 (PGK1) depletion is shown to efficiently activate Nrf2 signaling by inducing methylglyoxal modification of Kelch-like ECH-associated protein 1 (Keap1). We here identified a novel PGK1-targeting microRNA: microRNA-4523 (miR-4523). RNA fluorescent in situ hybridization, RNA pull-down, and Argonaute-2 RNA immunoprecipitation results confirmed a direct binding between miR-4523 and PGK1 mRNA in primary human osteoblasts and hFOB1.19 osteoblastic cells. Forced overexpression of miR-4523, using a lentiviral construct, robustly decreased PGK1 3'-UTR (untranslated region) luciferase activity and downregulated its expression in human osteoblasts and hFOB1.19 cells. Furthermore, miR-4523 overexpression activated the Nrf2 signaling cascade, causing Keap1-Nrf2 disassociation, Nrf2 protein stabilization, and its nuclear translocation as well as transcription activation of Nrf2-dependent genes (NQO1, GCLC, and HO1) in human osteoblasts. By expressing a UTR-null PGK1 construct, miR-4523 overexpression-induced Nrf2 cascade activation was however largely inhibited. Importantly, DEX-induced reactive oxygen species production, oxidative injury, and cell apoptosis were significantly attenuated by miR-4523 overexpression in human osteoblasts and hFOB1.19 cells. Such actions by miR-4523 were abolished by Nrf2 shRNA or knockout, but mimicked by PGK1 knockout (using CRISPR/Cas9 method). In PGK1 knockout human osteoblasts, miR-4523 overexpression failed to further increase Nrf2 cascade activation and offer osteoblast cytoprotection against DEX. Significantly, miR-4523 is downregulated in human necrotic femoral head tissues of DEX-taking patients. Together, PGK1 silencing by miR-4523 protected human osteoblasts from DEX through activation of the Nrf2 signaling cascade.

A fatal case of Exophiala dermatitidis meningoencephalitis in an immunocompetent host: A case report and literature review.

BACKGROUND: Central nervous system (CNS) infection due to Exophiala dermatitidis is rare and fatal, and primarily reported in immunocompromised patients or those with caspase recruitment domain-containing protein 9 deficiency. Herein, we describe a case of an otherwise healthy person (without underlying disease or gene deficiency) diagnosed with Exophiala dermatitidis meningoencephalitis. The patient achieved clinical remission under high-dose antifungal therapy in the first 14 months but died after 2 years of the therapy. CASE PRESENTATION: A 15-year-old student with headache and fever was admitted to our department. Lumbar puncture showed increased cerebrospinal fluid (CSF) pressure, moderately high CSF protein levels and cell counts, and a remarkable decrease in CSF glucose and chloride. Magnetic resonance imaging of the brain revealed multiple lesions and cerebral pia mater enhancement. CSF culture confirmed E. dermatitidis infection. We administered 4-week antifungal therapy of amphotericin B, but his CSF culture remained positive. After receiving the 12-week standard dose of voriconazole (200 mg q12h), the patient's CSF culture became negative, but his condition deteriorated with intracranial lesion enlargement. We administered a high-dose voriconazole therapy (600-800 mg per day) for 12 months, which led to clinical remission. The voriconazole dose was reduced due to adverse effects including hepatic dysfunction and hypokalemia, and the disease progressed with high intracranial pressure and epileptic seizures. CONCLUSIONS: CNS infection caused by E. dermatitidis is fatal and the most serious form of fungal infection. Initially, high-dose and long-term antifungal therapy could be effective. Gene defect and related antifungal immunodeficiency may be the most important pathogenic and lethal factor.

Comparison of the anterior and posterior approach in treating four-level cervical spondylotic myelopathy.

BACKGROUND: The optimal surgical approach for four-level cervical spondylotic myelopathy remains controversial. The purpose of this study was to compare clinical and radiological outcomes and complications between the anterior and posterior approaches for four-level cervical spondylotic myelopathy. METHODS: A total of 19 patients underwent anterior decompression and fusion and 25 patients underwent posterior laminoplasty and instrumentation in this study. Perioperative information, intraoperative blood loss, clinical and radiological outcomes, and complications were recorded. Japanese Orthopedic Association (JOA) score, 36-item short form survey (SF-36) score and cervical alignment were assessed. RESULTS: There were no significant differences in JOA scores between the anterior and posterior group preoperatively (11.6 ±â€Š1.6 vs. 12.1 ±â€Š1.5), immediately postoperatively (14.4 ±â€Š1.1 vs. 13.8 ±â€Š1.3), or at the last follow-up (14.6 ±â€Š1.0 vs. 14.2 ±â€Š1.1) (P > 0.05). The JOA scores significantly improved immediately postoperatively and at the last follow-up in both groups compared with their preoperative values. The recovery rate was significantly higher in the anterior group both immediately postoperatively and at the last follow-up. The SF-36 score was significantly higher in the anterior group at the last follow-up compared with the preoperative value (69.4 vs. 61.7). Imaging revealed that there was no significant difference in the Cobb angle at C2-C7 between the two groups preoperatively (-2.0°â€Š±â€Š7.3° vs. -1.4°â€Š±â€Š7.5°). The Cobb angle significantly improved immediately postoperatively (12.3°â€Š±â€Š4.2° vs. 9.2°â€Š±â€Š3.6°) and at the last follow-up (12.4°â€Š±â€Š3.5° vs. 9.0°â€Š±â€Š2.6°) in both groups compared with their preoperative values (P = 0.00). Three patients had temporary dysphagia in the anterior group and four patients had persistent axial symptoms in the posterior group. CONCLUSIONS: Both the anterior and posterior approaches were effective in treating four-level cervical spondylotic myelopathy in terms of neurological clinical outcomes and radiological features. However, the JOA score recovery rate and SF-36 score in the anterior group were significantly higher. Persistent axial pain could be a major concern when undertaking the posterior approach.

Efficacy and safety of the long-acting fusion inhibitor albuvirtide in antiretroviral-experienced adults with human immunodeficiency virus-1: interim analysis of the randomized, controlled, phase 3, non-inferiority TALENT study.

BACKGROUND: Albuvirtide is a once-weekly injectable human immunodeficiency virus (HIV)-1 fusion inhibitor. We present interim data for a phase 3 trial assessing the safety and efficacy of albuvirtide plus lopinavir-ritonavir in HIV-1-infected adults already treated with antiretroviral drugs. METHODS: We carried out a 48-week, randomized, controlled, open-label non-inferiority trial at 12 sites in China. Adults on the World Health Organization (WHO)-recommended first-line treatment for >6 months with a plasma viral load >1000 copies/mL were enrolled and randomly assigned (1:1) to receive albuvirtide (once weekly) plus ritonavir-boosted lopinavir (ABT group) or the WHO-recommended second-line treatment (NRTI group). The primary endpoint was the proportion of patients with a plasma viral load below 50 copies/mL at 48 weeks. Non-inferiority was prespecified with a margin of 12%. RESULTS: At the time of analysis, week 24 data were available for 83 and 92 patients, and week 48 data were available for 46 and 50 patients in the albuvirtide and NRTI groups, respectively. At 48 weeks, 80.4% of patients in the ABT group and 66.0% of those in the NRTI group had HIV-1 RNA levels below 50 copies/mL, meeting the criteria for non-inferiority. For the per-protocol population, the superiority of albuvirtide over NRTI was demonstrated. The frequency of grade 3 to 4 adverse events was similar in the two groups; the most common adverse events were diarrhea, upper respiratory tract infections, and grade 3 to 4 increases in triglyceride concentration. Renal function was significantly more impaired at 12 weeks in the patients of the NRTI group who received tenofovir disoproxil fumarate than in those of the ABT group. CONCLUSIONS: The TALENT study is the first phase 3 trial of an injectable long-acting HIV drug. This interim analysis indicates that once-weekly albuvirtide in combination with ritonavir-boosted lopinavir is well tolerated and non-inferior to the WHO-recommended second-line regimen in patients with first-line treatment failure. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT02369965; https://www.clinicaltrials.gov.Chinese Clinical Trial Registry No. ChiCTR-TRC-14004276; http://www.chictr.org.cn/enindex.aspx.

Interferon-α2b spray inhalation did not shorten virus shedding time of SARS-CoV-2 in hospitalized patients: a preliminary matched case-control study.

BACKGROUND: Currently, there are no drugs that have been proven to be effective against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Because of its broad antiviral activity, interferon (IFN) should be evaluated as a potential therapeutic agent for treatment of coronavirus disease 2019 (COVID-19), especially while COVID-19-specific therapies are still under development. METHODS: Confirmed COVID-19 patients hospitalized in the First Affiliated Hospital, School of Medicine, Zhejiang University in Hangzhou, China, from January 19 to February 19, 2020 were enrolled in a retrospective study. The patients were separated into an IFN group and a control group according to whether they received initial IFN-α2b inhalation treatment after admission. Propensity-score matching was used to balance the confounding factors. RESULTS: A total of 104 confirmed COVID-19 patients, 68 in the IFN group and 36 in the control group, were enrolled. Less hypertension (27.9% vs. 55.6%, P=0.006), dyspnea (8.8% vs. 25.0%, P=0.025), or diarrhea (4.4% vs. 19.4%, P=0.030) was observed in the IFN group. Lower levels of albumin and C-reactive protein and higher level of sodium were observed in the IFN group. Glucocorticoid dosage was lower in the IFN group (median, 40 vs. 80 mg/d, P=0.025). Compared to the control group, fewer patients in the IFN group were ventilated (13.2% vs. 33.3%, P=0.015) and admitted to intensive care unit (ICU) (16.2% vs. 44.4%, P=0.002). There were also fewer critical patients in the IFN group (7.4% vs. 25.0%, P=0.017) upon admission. Although complications during admission process were comparable between groups, the discharge rate (85.3% vs. 66.7%, P=0.027) was higher and the hospitalization time (16 vs. 21 d, P=0.015) was shorter in the IFN group. When other confounding factors were not considered, virus shedding time (10 vs. 13 d, P=0.014) was also shorter in the IFN group. However, when the influence of other factors was eliminated using propensity score matching, virus shedding time was not significantly shorter than that of the control group (12 vs. 15 d, P=0.206). CONCLUSIONS: IFN-α2b spray inhalation did not shorten virus shedding time of SARS-CoV-2 in hospitalized patients.

Liver Enzyme Elevation in Coronavirus Disease 2019: A Multicenter, Retrospective, Cross-Sectional Study.

INTRODUCTION: Elevated liver enzyme levels are observed in patients with coronavirus disease 2019 (COVID-19); however, these features have not been characterized. METHODS: Hospitalized patients with COVID-19 in Zhejiang Province, China, from January 17 to February 12, 2020, were enrolled. Liver enzyme level elevation was defined as alanine aminotransferase level >35 U/L for men and 25 U/L for women at admission. Patients with normal alanine aminotransferase levels were included in the control group. Reverse transcription polymerase chain reaction was used to confirm severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, and patients symptomatic with SARS-CoV-2 infection were defined as patients with COVID-19. Epidemiological, demographic, clinical, laboratory, treatment, and outcome data were collected and compared. RESULTS: Of 788 patients with COVID-19, 222 (28.2%) patients had elevated liver enzyme levels (median [interquartile range {IQR}] age, 47.0 [35.0-55.0] years; 40.5% women). Being male, overweight, and smoking increased the risk of liver enzyme level elevation. The liver enzyme level elevation group had lesser pharyngalgia and more diarrhea than the control group. The median time from illness onset to admission was 3 days for liver enzyme level elevation groups (IQR, 2-6), whereas the median hospitalization time for 86 (38.7%) discharged patients was 13 days (IQR, 11-16). No differences in disease severity and clinical outcomes were noted between the groups. DISCUSSION: We found that 28.2% of patients with COVID-19 presented with elevated liver enzyme levels on admission, which could partially be related to SARS-CoV-2 infection. Male patients had a higher risk of liver enzyme level elevation. With early medical intervention, liver enzyme level elevation did not worsen the outcomes of patients with COVID-19.

Erratum to: Kinetic Characterization of Tyrosinase-catalyzed Oxidation of Four Polyphenols.

The article "Kinetic Characterization of Tyrosinase-catalyzed Oxidation of Four Polyphenols", written by Wan-yu LIU, Congming ZOU, Jian-hua HU, Zi-jun XU, Lu-qin SI, Jun-jun LIU, Jian-geng HUANG, was originally published electronically on the publisher's internet portal on May 2020 without open access. With the author(s)' decision to opt for Open Choice, the copyright of the article is changed to © The Author(s) 2020 and the article is forthwith distributed under a Creative Commons Attribution 4.0 International License ( https://creativecommons.org/licenses/by/4.0/ ), which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made.The original article has been corrected.

Clinical characteristics of different subtypes and risk factors for the severity of illness in patients with COVID-19 in Zhejiang, China.

BACKGROUND: The outbreak of coronavirus disease 2019 (COVID-19) is now becoming an enormous threat to public health. The clinical spectrum of COVID-19 is extensive, of which critical cases are with rapid disease progression and high mortality. The aim of our study is to summarize the characteristics of different subtypes and explore risk factors of illness severity for early identification and prompt treatment. METHODS: In this retrospective study, we collected data of patients confirmed COVID-19 in Zhejiang Province from 17 January to 12 February 2020. According to the definition of clinical classification, we divided confirmed cases into four types, and summarize epidemiological and clinical characteristics, laboratory and radiograph findings, treatments, and outcomes, respectively. Moreover, we used univariate and multivariate ordinal logistic regression models to explore risk factors for the severity of illness in patients with COVID-19. RESULTS: A total of 788 patients were enrolled in our study, of whom 52 cases (6.6%) were mild type, 658 cases (83.5%) were common type, 61 cases (7.2%) were severe type, and 17 cases (2.2%) were critical type. Multivariate ordinal logistic regression demonstrated increasing odds of the severity of illness in patients with COVID-19 associated with male (odds ratio [OR] = 1.7, 95% confidence interval [CI]: 1.2-2.6 P = 0.008), fever (OR = 3.6, 95% CI: 2.1-6.3, P <  0.001), cough (OR = 1.7, 95% CI: 1.0-2.9, P = 0.041), hemoptysis (OR = 3.4, 95% CI: 1.1-10.3, P = 0.032), gastrointestinal symptoms (OR = 1.9, 95% CI: 1.0-3.5, P = 0.047), hypertension (OR = 2.6, 95% CI: 1.2-5.6, P = 0.013). With the increase of age-grading, risk for the severity of illness was gradually higher (≤ 18 years [OR = 1.0], 19-40 years [OR = 12.7, 95% CI: 4.5-36.0, P < 0.001], 41-65 years [OR = 14.8, 95% CI: 5.2-42.1, P <  0.001], ≥ 66 years [OR = 56.5, 95% CI: 17.1-186.5, P < 0.001]). CONCLUSIONS: Clinicians should pay close attention to these features in patients with COVID-19 including older age, male, fever, cough, hemoptysis, gastrointestinal symptoms and hypertension to identify the severity of illness as early as possible.

Serum chitinase-3-like protein 1 is a biomarker of liver fibrosis in patients with chronic hepatitis B in China.

BACKGROUND: Serum chitinase-3-like protein 1 (CHI3L1) is a potential biomarker for fibrosis assessment. We aimed to evaluate serum CHI3L1 as a noninvasive diagnostic marker for chronic hepatitis B virus-related fibrosis. METHODS: Serum CHI3L1 levels were measured by ELISA in 134 chronic hepatitis B (CHB) patients. Significant fibrosis was defined as a liver stiffness > 9.7 kPa. The performance of CHI3L1 was assessed and compared to that of other noninvasive tests by receiver operating characteristic (ROC) analysis. RESULTS: Serum CHI3L1 levels were significantly higher in CHB patients with significant hepatic fibrosis (≥ F2, 81.9 ng/mL) than in those without significant hepatic fibrosis (< F2, 56.5 ng/mL) (P < 0.001). In CHB patients, the specificity and sensitivity of CHI3L1 for predicting significant fibrosis were 75.6% and 59.1%, respectively, with a cut-off of 76.0 ng/mL and an area under the ROC curve of 0.728 (95% CI: 0.637-0.820). CONCLUSIONS: Serum CHI3L1 levels could be an effective new serological biomarker for the diagnosis of liver. Moreover, CHI3L1 is feasible in monitoring disease progression.

Comparison of epidemiological and clinical characteristics of COVID-19 patients with and without Wuhan exposure history in Zhejiang Province, China.

BACKGROUND: A novel coronavirus called severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), first identified in Wuhan, China, has been rapidly spreading around the world. This study investigates the epidemiological and clinical characteristics of coronavirus disease 2019 (COVID-19) patients in Zhejiang Province who did or did not have a history of Wuhan exposure. METHODS: We collected data from medical records of confirmed COVID-19 patients in Zhejiang Province from Jan. 17 to Feb. 7, 2020 and analyzed epidemiological, clinical, and treatment data of those with and without recorded recent exposure in Wuhan. RESULTS: Patients in the control group were older than those in the exposure group ((48.19±16.13) years vs. (43.47±13.12) years, P<0.001), and more were over 65 years old (15.95% control vs. 5.60% exposure, P<0.001). The rate of clustered onset was also significantly higher in the control group than in the exposure group (31.39% vs. 18.66%, P<0.001). The symptom of a sore throat in patients in the exposure group was significantly higher than that in the control group (17.30% vs. 10.89%, P=0.01); however, headache in the exposure group was significantly lower than that in the control group (6.87% vs. 12.15%, P=0.015). More patients in the exposure group had a significantly lower level of lactate dehydrogenase (LDH) and aspartate aminotransferase (AST) than those in the control group. There was no significant difference in any degree of COVID-19 including mild, severe, and critical between the two groups. CONCLUSIONS: From the perspective of epidemiological and clinical characteristics, there was no significant difference between COVID-19 patients with and without Wuhan exposure history.

Smartphone assisted colorimetric and fluorescent triple-channel signal sensor for ascorbic acid assay based on oxidase-like CoOOH nanoflakes.

Ascorbic acid (AA) is an important diet-derived antioxidant to human body. Thus, efficient and accurate detection of AA is of considerable significance in food analysis. Herein, smartphone assisted colorimetric and fluorescent triple-channel signal sensor has been developed for AA monitoring based on oxidase-like CoOOH nanoflakes. CoOOH nanoflakes can efficiently catalyze the oxidation of p-phenylenediamine (p-PD) into reddish brown p-PDox. The carbon dots (C-dots) are further introduced, of which the fluorescence can be quenched by p-PDox. However, in the presence of AA, the CoOOH nanoflakes is reduced and thus collapsed. As a result, the oxidation of p-PD is restrained, and thus the fluorescence of C-dots keeps strong. Based on AA induced light color, low absorbance, and strong fluorescence, triple-channel signal sensor has been proposed for AA determination. The AA assay shows a dynamic response range from 0.5 to 10 µM with a detection limit of 0.09 µM. The method assay allows detection of AA in real samples such as fruit juices. Combination with portable smartphone, the developed sensor is potential for AA determination in resource-poor settings.

Kinetic Characterization of Tyrosinase-catalyzed Oxidation of Four Polyphenols.

Phenolic compounds such as chlorogenic acid, cryptochlorogenic acid, neochlorogenic acid and caffeic acid are widely distributed in fruits, vegetables and traditional Chinese medicines with a wide range of biological activities. Tyrosinase plays a critical role in the food industry, but recent studies have proposed unexplored aspects of clinical application. Tyrosinase-catalyzed oxidation of four polyphenols as well as its underlying mechanism remains unclear. In the current work, we investigated the kinetic properties of tyrosinase-catalyzed oxidation of the four polyphenols of interest. To measure the unstable o-quinone products, an analytical method using 3-methyl-2-benzothiazolinone hydrazone (MBTH) was established. The optimal incubation time, buffer pH, temperature and enzyme concentration for the enzyme activity in the presence of each polyphenol of interest were investigated. Under the final optimized conditions, the kinetics and substrate specificity of four polyphenols were examined. Kinetic data showed that tyrosinase had the greatest substrate affnity to chlorogenic acid compared with its isomers and caffeic acid. The catalytic effciency with chlorogenic acid was 8- to 15-fold higher than that with the other 3 polyphenols. Molecular docking study demonstrated that the tight binding of chlorogenic acid at the peripheral site should be the major reason for the specifcity to chlorogenic acid. In light of this, the rational design of high-affnity inhibitors against tyrosinase may focus on the binding of both the Cu site and peripheral site. This study will supply a basis for the selection of phenolic acids in food industry and health care.

Epidemiological, clinical and virological characteristics of 74 cases of coronavirus-infected disease 2019 (COVID-19) with gastrointestinal symptoms.

OBJECTIVE: The SARS-CoV-2-infected disease (COVID-19) outbreak is a major threat to human beings. Previous studies mainly focused on Wuhan and typical symptoms. We analysed 74 confirmed COVID-19 cases with GI symptoms in the Zhejiang province to determine epidemiological, clinical and virological characteristics. DESIGN: COVID-19 hospital patients were admitted in the Zhejiang province from 17 January 2020 to 8 February 2020. Epidemiological, demographic, clinical, laboratory, management and outcome data of patients with GI symptoms were analysed using multivariate analysis for risk of severe/critical type. Bioinformatics were used to analyse features of SARS-CoV-2 from Zhejiang province. RESULTS: Among enrolled 651 patients, 74 (11.4%) presented with at least one GI symptom (nausea, vomiting or diarrhoea), average age of 46.14 years, 4-day incubation period and 10.8% had pre-existing liver disease. Of patients with COVID-19 with GI symptoms, 17 (22.97%) and 23 (31.08%) had severe/critical types and family clustering, respectively, significantly higher than those without GI symptoms, 47 (8.14%) and 118 (20.45%). Of patients with COVID-19 with GI symptoms, 29 (39.19%), 23 (31.08%), 8 (10.81%) and 16 (21.62%) had significantly higher rates of fever >38.5°C, fatigue, shortness of breath and headache, respectively. Low-dose glucocorticoids and antibiotics were administered to 14.86% and 41.89% of patients, respectively. Sputum production and increased lactate dehydrogenase/glucose levels were risk factors for severe/critical type. Bioinformatics showed sequence mutation of SARS-CoV-2 with m6A methylation and changed binding capacity with ACE2. CONCLUSION: We report COVID-19 cases with GI symptoms with novel features outside Wuhan. Attention to patients with COVID-19 with non-classic symptoms should increase to protect health providers.