Chiral Sensing of Tryptophan Enantiomers Based on the Enzyme Mimics of ß-Cyclodextrin-Modified Sulfur Quantum Dots.

Chiral recognition of amino acid plays a significant role in pharmaceutical, medical, and food science. This study describes a chiral sensing system of ß-cyclodextrin (ß-CD)-coated sulfur quantum dots (CD-SQDs) for the selective fluorescence recognition of tryptophan (Trp) enantiomers. CD-SQDs were prepared by a facile assembly fission method and could selectively recognize L-Trp by the different binding ability between L/D-Trp and ß-CD. The inclusion of L-Trp and the stereoselective catalysis of CD-SQDs enzyme mimics cause the increased fluorescence intensity of CD-SQDs, which has a linear response ranging from 10 to 500 nM and the detection limit as 2.3 nM. CD-SQDs also show great selectivity for L-Trp from the commercial compound amino acid injection. The study could provide an effective method for the chiral recognition of amino acid enantiomers based on the catalytic activity of nanoenzymes.

A novel, ultrafast, ultrasensitive diagnosis platform for the detection of SARS-COV-2 using restriction endonuclease-mediated reverse transcription multiple cross displacement amplification.

Coronavirus disease 2019 (COVID-19) is a highly infectious disease caused by severe acute respiratory syndrome coronavirus 2 (SARS-COV-2). Though many methods have been used for detecting SARS-COV-2, development of an ultrafast and highly sensitive detection strategy to screen and/or diagnose suspected cases in the population, especially early-stage patients with low viral load, is significant for the prevention and treatment of COVID-19. In this study, a novel restriction endonuclease-mediated reverse transcription multiple cross displacement amplification (MCDA) combined with real-time fluorescence analysis (rRT-MCDA) was successfully established and performed to diagnose COVID-19 infection (COVID-19 rRT-MCDA). Two sets of specific SARS-COV-2 rRT-MCDA primers targeting opening reading frame 1a/b (ORF1ab) and nucleoprotein (NP) genes were designed and modified according to the reaction mechanism. The SARS-COV-2 rRT-MCDA test was optimized and evaluated using various pathogens and clinical samples. The optimal reaction condition of SARS-COV-2 rRT-MCDA assay was 65°C for 36 min. The SARS-COV-2 rRT-MCDA limit of detection (LoD) was 6.8 copies per reaction. Meanwhile, the specificity of SARS-COV-2 rRT-MCDA assay was 100%, and there was no cross-reaction with nucleic acids of other pathogens. In addition, the whole detection process of SARS-COV-2 rRT-MCDA, containing the RNA template processing (15 min) and real-time amplification (36 min), can be accomplished within 1 h. The SARS-COV-2 rRT-MCDA test established in the current report is a novel, ultrafast, ultrasensitive, and highly specific detection method, which can be performed as a valuable screening and/or diagnostic tool for COVID-19 in clinical application.

Initial Clinical Characteristics of 146 Patients with COVID-19 Reported in Guizhou Province, China: A Survival Analysis.

INTRODUCTION: Coronavirus disease 2019 (COVID-19) has caused an outbreak around the world. Early detection of severe illness is crucial for patients' survival. We analysed initial clinical characteristics of 146 patients with COVID-19 reported in Guizhou province, China to explore risk factors for transforming mild illness to severe. METHODOLOGY: Data of 146 laboratory-confirmed cases were collected and evaluated by the survival analysis of univariate and multivariate Cox proportional hazards model. RESULTS: On initial presentation, patients had fever (51.05%), dry cough (45.45%), headache (16.08%), shortness of breath (7.75%) and gastrointestinal symptoms (13.99%). Among 146 laboratory-confirmed cases, 30 patients (20.55%) had severe illness and needed Intensive Care Unit care for supportive treatment. The remaining patients (116, 79.45%) were non-severe cases. Nineteen (19/146, 13.01%) of 30 patients in the Intensive Care Unit had comorbidities, including hypertension (12, 40.00%), diabetes (5, 16.67%), cardiovascular disease (5, 16.67%) and pulmonary disease (4, 13.33%). For survival analysis, patients who had fever (HR = 3.30, 95% CI = 1.31, 8.29) and comorbidities (HR = 9.76, 95% CI = 4.28, 22.23) at baseline were more likely to be admitted into the Intensive Care Unit. Few variables were not related to the survival time of discharge from baseline to discharge and from Intensive Care Unit care to discharge. CONCLUSIONS: Severe patients with COVID-19 should be paid more attention. On initial symptoms, many patients did not have fever, but those with fever were more likely to be admitted to the Intensive Care Unit. Comorbidities were likewise a risk factor of severe COVID-19.

Acupuncture for headache in COVID-19: A protocol for systematic review and meta-analysis.

BACKGROUND: Coronavirus disease 2019 (COVID-19) is an acute respiratory infectious disease which making people difficult to breathe and often accompanied with headache. Acupuncture have been proved the therapeutic effect on headache, but there has been no high-quality evidence on acupuncture for the headache in COVID-19. This study is designed to evaluate the effectiveness and safety of acupuncture for headache in COVID-19. METHODS: Randomized controlled trials from December 2019 to July 2021 will be included without restrictions on language or publication date. PubMed, EMBASE, Cochrane Library, Web of Science, Chinese Biomedical Databases, China National Knowledge Infrastructure, Wanfang database, and VIP database will be searched. Two researchers will independently select studies, extract data and evaluate study quality. Cochrane risk of bias tool for randomized trials will be used to assess the risk of bias of included studies. Statistical analyses will be performed using the Review Manager V.5.3 and stata 14.0. ETHICS AND DISSEMINATION: This study will not involve personal information. Ethical approval will not be required. We will publish the results in a peer-reviewed journal. PROSPERO TRIAL REGISTRATION NUMBER: CRD42021270722.

Comparison of fruit morphology and nutrition metabolism in different cultivars of kiwifruit across developmental stages.

Kiwifruit (Actinidia) is becoming increasingly popular worldwide due to its favorable flavour and high vitamin C content. However, quality parameters vary among cultivars. To determine the differences in quality and metabolic parameters of kiwifruit, we monitored the growth processes of 'Kuilv' (Actinidia arguta), 'Hongyang' (Actinidia chinensis) and 'Hayward' (Actinidia deliciosa). We found that 'Kuilv' required the shortest time for fruit development, while 'Hayward' needed the longest time to mature. The fruit size of 'Hayward' was the largest and that of 'Kuilv' was the smallest. Furthermore, 'Hongyang' showed a double-S shape of dry matter accumulation, whereas 'Kuilv' and 'Hayward' showed a linear or single-S shape pattern of dry matter accumulation during development. The three cultivars demonstrated the same trend for total soluble solids accumulation, which did not rise rapidly until 90-120 days after anthesis. However, the accumulation of organic acids and soluble sugars varied among the cultivars. During later fruit development, the content of glucose, fructose and quinic acid in 'Kuilv' fruit was far lower than that in 'Hongyang' and 'Hayward'. On the contrary, 'Kuilv' had the highest sucrose content among the three cultivars. At maturity, the antioxidative enzymatic systems were significantly different among the three kiwifruit cultivars. 'Hongyang' showed higher activities of superoxide dismutase than the other cultivars, while the catalase content of 'Hayward' was significantly higher than that of 'Hongyang' and 'Kuilv'. These results provided knowledge that could be implemented for the marketing, handling and post-harvest technologies of the different kiwifruit cultivars.

A one-step, one-pot CRISPR nucleic acid detection platform (CRISPR-top): Application for the diagnosis of COVID-19.

The existing CRISPR-mediated diagnostic tests require a two-step procedure (DNA or RNA amplification followed by CRISPR-mediated sequence-specific detection) for nucleic acid detection, which increases complexity and the risk of sample cross-contamination. Here, we report a new CRISPR-mediated test, called CRISPR-top (CRISPR-mediated testing in one-pot), which integrates simultaneous target pre-amplification with CRISPR/cas12b-mediated detection into a one-pot reaction mixture, performed at a constant temperature. The novel CRISPR-top assay was applied to detect severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the causative agent for COVID-19 (coronavirus disease 2019). COVID-19 CRISPR-top targets the ORF1ab (opening reading frame 1a/b) and NP (nucleoprotein) genes of SARS-CoV-2, and operates at 59 °C for 40 min with minimal instrument. The COVID-19 CRISPR-top assay can return results within 60-min and is easily interpreted by visual fluorescence or lateral flow readouts. The analytical limit of detection (LoD) for COVID-19 CRISPR-top is 10 copies (for each detection target) per reaction with no cross-reactivity observed from non-SARS-CoV-2 templates. Among clinically collected non-COVID-19 samples, the assay's specificity was 100% (80/80 oropharynx swab samples). Among 52 COVID-19 positive clinical samples collected, the COVID-19 CRISPR-top assay yielded 38 (73.1%) positive results using fluorescence readout and 35 (67.3%) positive results with lateral-flow readout. These diagnostic results were similar to those obtained using RT-PCR (34 positive (65.4%)). These data indicate that COVID-19 CRISPR-top is a simple, rapid, accurate and highly sensitive method for SARS-CoV-2 detection which can be used in the clinic, field laboratories and primary care facilities in resource-challenged settings.

Detoxification modification of coal-tar pitch by ultraviolet & microwave radiation-enhanced chemical reaction and toxicity evaluation by chemical index and cytotoxicity assay in vitro.

Although coal tar pitch (CTP) has a large yield in China, its large-scale and effective utilization is significantly hindered because of existing and possibly releasing polycyclic aromatic hydrocarbons (PAHs). Therefore, it is an imminent problem how to prepare an environmentally friendly CTP by detoxification modification. In the investigation, a typical CTP was subjected to structural characterization via solid-state 13C NMR and gas chromatograph/mass spectrometer, which confirmed the existence of dominant PAHs such as fluoranthene, pyrene, as well as benzo[a]pyrene, and few heterocyclic compounds. Subsequently, the CTP was modified using 10-undecenal via alkylation reaction enhanced by ultraviolet & microwave radiation. Compared with the original CTP, the total content of 16 toxic PAHs in the modified CTP decreased with a reduction efficiency of above 90%. According to different environmental standards, toxic equivalent quotient of CTP after modification was reduced by above 90%. In order to veritably and fully evaluate the toxicity of CTP, a living vascular smooth muscle cell (A-10 cell) in vitro was used in the cell counting kit-8 assay. The viability of A-10 cell was always higher when exposed to modified CTP than the original CTP. These results powerfully indicated that the enhanced modification was actually effective and efficient for reducing the toxicity of CTP.

Excretion of SARS-CoV-2 through faecal specimens.

Coronavirus disease 2019 (COVID-19) has become a pandemic with increasing numbers of cases worldwide. SARS-CoV-2, the causative virus of COVID-19, is mainly transmitted through respiratory droplets or through direct and indirect contact with an infected person. The possibility of potential faecal-oral transmission was investigated in this study. We collected 258 faecal specimens from nine provinces in China and detected the nucleic acid of SARS-CoV-2 using real-time RT-PCR. Vero cells were used to isolate the virus from SARS-CoV-2 nucleic acid positive samples, after which sequencing of Spike gene in eight samples was performed. In all, 93 of 258 (36%) stool samples were positive for SARS-CoV-2 RNA. The positive rates of critical, severe, moderate, and mild patients were 54.4%, 56.1%, 30.8%, and 33.3%, respectively. The content of nucleic acid increased within 2 weeks after the onset of the disease. From the perspective of clinical typing, the nucleic acid can be detected in the faeces of critical patients within two weeks and until four to five weeks in the faeces of severe and mild patients. SARS-CoV-2 was isolated from stool specimens of two severe patients. Four non-synonymous mutations in Spike gene were newly detected in three stool samples. A small number of patients had strong faecal detoxification ability. The live virus in faeces could be an important source of contamination, which may lead to infection and further spread in areas with poor sanitary conditions. The findings of this study have public health significance and they should be considered when formulating disease control strategies.

Highly sensitive and specific diagnosis of COVID-19 by reverse transcription multiple cross-displacement amplification-labelled nanoparticles biosensor.

BACKGROUND: The ongoing outbreak of the novel human coronavirus severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) (also known as 2019-nCoV) has become a global health concern. Rapid and easy-to-use diagnostic techniques are urgently needed to diagnose SARS-CoV-2 infection. METHODS: We devised a reverse transcription multiple cross-displacement amplification (RT-MCDA) coupled with a nanoparticle-based biosensor assay (RT-MCDA-BS) for rapid, sensitive and specific diagnosis of coronavirus disease 2019 (COVID-19). Two primer sets were designed to target the open reading frame 1a/b and nucleoprotein gene of SARS-CoV-2. A total of 183 clinical samples, including 65 patients with COVID-19 infection and 118 patients with other pathogen infections were used to testify the assay's feasibility. Diagnosis results were reported visually using the biosensor. FINDINGS: The assay designed was performed using a simple instrument which could maintain the reaction in a constant temperature at 64°C for only 35 min. The total COVID-19 RT-MCDA-BS test procedure could be finished within 1 h. The COVID-19 RT-MCDA-BS could detect down to five copies of target sequences. Among 65 clinical samples from the COVID-19 patients, 22 (33.8%) positive results were obtained from faeces, nasal, pharyngeal and anal swabs via COVID-19 RT-MCDA-BS assay, while real-time reverse transcription-PCR assay only detected 20 (30.7%) positive results in these samples. No positive results were obtained from clinical samples with non-COVID-19 infections. INTERPRETATION: COVID-19 RT-MCDA-BS was a rapid, reliable, low-cost and easy-to-use assay, which could provide an attractive laboratory tool to diagnose COVID-19 in multiple clinical specimens, especially for field, clinic laboratories and primary care facilities in resource-poor settings.

Characteristics of school food poisoning incident in Guizhou Province during 2011 to 2018 / 中国学校卫生

Objective@#To analyze the rule and characteristics of school food poisoning incident in Guizhou Province during 2011-2018. @*Methods@#Data of school food poisoning incidents were collected from the Foodborne Disease Outbreak Surveillance System in Guizhou Province during 2011-2018 and statistically analyzed.@*Results@#A total of 78 cases of food poisoning occurred in schools in Guizhou Province during 2011-2018. Among the 1 506 cases, 869 hospitalized and 1 died. May was peak time for school food poisoning. Most of the incidents (83.33%, 65/78) occurred in the school canteens. Plant origin products (50%, 39/78), especially spoiled rice, were the most common types of food poisoning in school(16.67%, 13/78).@*Conclusion@#Primary and secondary school students were the largest group for school food poisoning in Guizhou province. It was necessary to strengthen the supervision and management of school canteens and surrounding places, as well as to improve the food safety awareness of food operators and students, preventing similar incidents from happening again.

Co-overexpression of AVP1 and PP2A-C5 in Arabidopsis makes plants tolerant to multiple abiotic stresses.

Abiotic stresses are major threats to agricultural production. Drought and salinity as two of the major abiotic stresses cause billions of losses in agricultural productivity worldwide each year. Thus, it is imperative to make crops more tolerant. Overexpression of AVP1 or PP2A-C5 was previously shown to increase drought and salt stress tolerance, respectively, in transgenic plants. In this study, the hypothesis that co-overexpression of AVP1 and PP2A-C5 would combine their respective benefits and further improve salt tolerance was tested. The two genes were inserted into the same T-DNA region of the binary vector and then introduced into the Arabidopsis genome through Agrobacterium-mediated transformation. Transgenic Arabidopsis plants expressing both AVP1 and PP2A-C5 at relatively high levels were identified and analyzed. These plants displayed enhanced tolerance to NaCl compared to either AVP1 or PP2A-C5 overexpressing plants. They also showed tolerance to other stresses such as KNO3 and LiCl at harmful concentrations, drought, and phosphorus deficiency at comparable levels with either AVP1 or PP2A-C5 overexpressing plants. This study demonstrates that introducing multiple genes in single T-DNA region is an effective approach to create transgenic plants with enhanced tolerance to multiple stresses.

Graphene-Based Nanomaterials: Potential Tools for Neurorepair.

Graphene, with its outstanding electrical properties, large surface area, and excellent mechanical properties, is found in a wide variety of applications in biomimetic substrates and biomedicine, with the result that there is growing interest in the effect of graphene-based nanomaterials on neural cells. This review sums up current research on the effectiveness of graphene and its derivatives on neural cells. We emphasize the biocompatibility of graphene and its derivatives, and how they affect the behavior of neural cells, including adhesion, proliferation, neurite outgrowth and differentiation. In addition, we discuss at great length the literature on graphenebased nanomaterials for drug delivery applications. While their in vivo effects on the nervous system remain to be explored, encouraging findings indicate that graphene-based nanomaterials have significant potential as novel therapies for neurodegenerative disease.

The Effects of Transcription Directions of Transgenes and the gypsy Insulators on the Transcript Levels of Transgenes in Transgenic Arabidopsis.

Manipulation of a single abiotic stress-related gene could improve plant performance under abiotic stress conditions. To simultaneously increase plant tolerance to multiple stresses, it is usually required to overexpress two (or more) genes in transgenic plants. The common strategy is to assemble two or more expression cassettes, where each gene has its own promoter and terminator, within the same T-DNA. Does the arrangement of the two expression cassettes affect expression of the two transgenes? Can we use the Drosophila gypsy insulator sequence to increase the expression of the two transgenes? Answers to these questions would contribute to design better transformation vectors to maximize the effects of multi-gene transformation. Two Arabidopsis genes, PP2A-C5 and AVP1, and the gypsy insulator sequence were used to construct six transformation vectors with or without the gypsy insulator bracketing the two expression cassettes: uni-directional transcription, divergent transcription, and convergent transcription. Total RNAs were isolated for reverse transcription- quantitative real-time polymerase chain reaction (RT-qPCR) assays and a thorough statistical analysis was conducted for the RT-qPCR data. The results showed that the gypsy insulator does promote the expression of two transgenes in transgenic plants. Besides, the plants containing the divergent transcription cassettes tend to have more correlated expression of both genes.

RICTOR expression in esophageal squamous cell carcinoma and its clinical significance.

Esophageal cancer is one of the most common malignant tumors in the world, and its incidence is the eighth highest; meanwhile, its fatality rate is the sixth highest. The PI3K/Akt/mTOR signaling pathway plays a required role in human cancer, including cell survival, metabolism and migration. As a kind of important scaffold protein in mTORC2, RICTOR has showed over-expression in several malignancies like melanoma and endometrial cancer. In this research, we selected 201 cases of paraffin specimens from patients diagnosed as esophageal squamous cell carcinoma after surgical treatment and then estimated the RICTOR expression in each esophageal squamous cell carcinoma tissue by using the immunohistochemical streptavidin-peroxidase technique. Then, we analyzed the association among the clinicopathological parameters, the prognosis and the expression of RICTOR. Eventually, we found that the percentage of RICTOR-positive expression in 201 ESCC samples is 70.6% (142/201) and the figure for RICTOR-negative or RICTOR-doubtful-positive expression is 29.4% (59/201). RICTOR expression positively correlated with ESCC patients' AJCC stage (P = 0.011) and showed an opposite trend with survival (P = 0.007). Based on univariate and multivariate Cox proportional hazards regression analysis, RICTOR-positive expression, AJCC staging III or IV and nodal metastasis are prognostic factors and the former two are independent risk factors for ESCC. In conclusion, our study showed potential that targeting RICTOR may represent new effective inhibitors for treating ESCC.

Safflower Yellow regulates microglial polarization and inhibits inflammatory response in LPS-stimulated Bv2 cells.

Activated microglia, especially polarized M1 cells, produce pro-inflammatory cytokines and free radicals, thereby contributing directly to neuroinflammation and various brain disorders. Given that excessive or chronic neuroinflammation within the central nervous system (CNS) exacerbates neuronal damage, molecules that modulate neuroinflammation are candidates as neuroprotective agents. In this study, we provide evidence that Safflor yellow (SY), the main active component in the traditional Chinese medicine safflower, modulates inflammatory responses by acting directly on BV2 microglia. LPS stimulated BV2 cells to upregulate expression of TLR4-Myd88 and MAPK-NF-κB signaling pathways and to release IL-1ß, IL-6, TNF-α, and COX-2. However, SY treatment inhibited expression of TLR4-Myd88 and p-38/p-JNK-NF-κB, downregulated expression of iNOS, CD16/32, and IL-12, and upregulated CD206 and IL-10. In conclusion, our results demonstrate that SY exerts an anti-inflammatory effect on BV2 microglia, possibly through TLR-4/p-38/p-JNK/NF-κB signaling pathways and the conversion of microglia from inflammatory M1 to an anti-inflammatory M2 phenotype.

The Features of Genetic Prion Diseases Based on Chinese Surveillance Program.

OBJECTIVE: To identify the features of Chinese genetic prion diseases. METHODS: Suspected Creutzfeldt-Jakob disease (CJD) cases that were reported under CJD surveillance were diagnosed and subtyped using the diagnostic criteria issued by the WHO. The general information concerning the patient, their clinical, MRI and EEG data, and the results of CSF 14-3-3 and PRNP sequencing were carefully collected from the database of the national CJD surveillance program and analyzed using the SPSS 11.5 statistical software program. RESULTS: Since 2006, 69 patients were diagnosed with genetic prion diseases and as having 15 different mutations. The median age of the 69 patients at disease onset was 53.5 years, varying from 19 to 80 years. The majority of patients displaying clinical symptoms were in the 50-59 years of age. FFI, T188K gCJD and E200K were the three most common subtypes. The disease appeared in the family histories of 43.48% of the patients. The clinical manifestations varied considerably among the various diseases. Patients who carried mutations in the N-terminus displayed a younger age of onset, were CSF 14-3-3 negative, had a family history of the condition, and experienced a longer duration of the condition. The clinical courses of T188K were significantly shorter than those of FFI and E200K gCJD, while the symptoms in the FFI group appeared at a younger age and for a longer duration. Moreover, the time intervals between the initial neurologist visit to the final diagnosis were similar among patients with FFI, T188K gCJD, E200K gCJD and other diseases. CONCLUSION: The features of Chinese genetic prion diseases are different from those seen in Europe and other Asian countries.

FSD-C10: A more promising novel ROCK inhibitor than Fasudil for treatment of CNS autoimmunity.

Rho-Rho kinase (Rho-ROCK) triggers an intracellular signalling cascade that regulates cell survival, death, adhesion, migration, neurite outgrowth and retraction and influences the generation and development of several neurological disorders. Although Fasudil, a ROCK inhibitor, effectively suppressed encephalomyelitis (EAE), certain side effects may limit its clinical use. A novel and efficient ROCK inhibitor, FSD-C10, has been explored. In the present study, we present chemical synthesis and structure of FSD-C10, as well as the relationship between compound concentration and ROCK inhibition. We compared the inhibitory efficiency of ROCKI and ROCK II, the cell cytotoxicity, neurite outgrowth and dendritic formation, neurotrophic factors and vasodilation between Fasudil and FSD-C10. The results demonstrated that FSD-C10, like Fasudil, induced neurite outgrowth of neurons and dendritic formation of BV-2 microglia and enhanced the production of neurotrophic factor brain-derived neurotrophic factor (BDNF), glial cell line-derived neurotrophic factor (GDNF) and neurotrophin-3 (NT-3). However, the cell cytotoxicity and vasodilation of FSD-C10 were relatively small compared with Fasudil. Although Fasudil inhibited both ROCK I and ROCK II, FSD-C10 more selectively suppressed ROCK II, but not ROCK I, which may be related to vasodilation insensitivity and animal mortality. Thus, FSD-C10 may be a safer and more promising novel ROCK inhibitor than Fasudil for the treatment of several neurological disorders.

Novel genospecies of Borrelia burgdorferi sensu lato from rodents and ticks in southwestern China.

By using multilocus sequence analysis, five Borrelia valaisiana-related strains isolated from rodents and ticks in southwestern China were eventually classified as a new genospecies of B. burgdorferi sensu lato rather than B. valaisiana. The finding explained the differences in transmission cycle and phenotype between B. valaisiana strains from Europe and B. valaisiana-related strains from eastern Asia.