Identification critical host factors for Japanese encephalitis virus replication via CRISPR screening of human sgRNA library.

Japanese encephalitis virus (JEV) is a pathogen with a substantial impact on both livestock and human health. However, the critical host factors in the virus life cycle remain poorly understood. Using a library comprising 123411 small guide RNAs (sgRNAs) targeting 19050 human genes, we conducted a genome-wide clustered regularly interspaced short palindromic repeats (CRISPR)/Cas9-based screen to identify essential genes for JEV replication. By employing knockout or knockdown techniques on genes, we identified eleven human genes crucial for JEV replication, such as prolactin releasing hormone receptor (PRLHR), activating signal cointegrator 1 complex subunit 3 (ASCC3), acyl-CoA synthetase long chain family member 3 (ACSL3), and others. Notably, we found that PRLHR knockdown blocked the autophagic flux, thereby inhibiting JEV infection. Taken together, these findings provide effective data for studying important host factors of JEV replication and scientific data for selecting antiviral drug targets.

Synthetic enhancers including TFREs improve transgene expression in CHO cells.

The human cytomegalovirus major immediate early gene (CMV) promoter is currently the most preferred promoter for recombinant therapeutic proteins (RTPs) production in CHO cells. To enhance the production of RTPs, five synthetic enhancers including multiple transcription factor regulatory elements (TFREs) were evaluated to enhance recombinant protein level in transient and stably transfected CHO cells. Compared with the control, four elements can enhance the report genes expression under both two transfected states. Further, the function of these four enhancers on human serum albumin (HSA) were investigated. We found that the transient expression can increase by up to 1.5 times, and the stably expression can maximum increase by up to 2.14 times. The enhancement of transgene expression was caused by the boost of their corresponding mRNA levels. Transcriptomics analysis was performed and found that transcriptional activation and cell cycle regulation genes were involved. In conclusion, optimization of enhancers in the CMV promoter could increase the production yield of transgene in transfected CHO cells, which has significance for developing high-yield CHO cell expression system.

MCNP simulation and experimental study in situ low-grade copper analysis based on PGNAA.

A prompt gamma neutron activation analysis (PGNAA) facility utilizing 252Cf source has been developed for in situ analysis of copper samples. Monte Carlo simulation is employed to determine optimal sizes for neutron moderator, gamma-ray shielding material, and thermal neutron absorber. Subsequently, based on the parameters optimized by MCNP, the PGNAA facility was constructed. Five sets of experimental samples containing low-grade copper concentration of 0 %, 0.5 %, 1 %, 1.5 % and 2 % are measured with the PGNAA facility. The results show that the minimum detectable concentration of copper is 0.218 %. The maximum relative deviation of copper is 8.53 %.

Reliable quantitative detection of uric acid in urine by surface-enhanced Raman spectroscopy with endogenous internal standard.

Abnormal levels of uric acid (UA) in urine serve as warning signs for gout and metabolic cardiovascular diseases, necessitating the monitoring of UA levels for early prevention. However, the current analytical methods employed suffer from limitations in terms of inadequate suitability for home-based applications and the requirement of non-invasive procedures. In this approach, creatinine, a metabolite with a constant excretion rate, was incorporated as an endogenous internal standard (e-IS) for calibration, presenting a rapid, pretreatment-free, and accurate strategy for quantitative determination of UA concentrations. By utilizing urine creatinine as an internal reference value to calibrate the signal fluctuation of surface-enhanced Raman spectroscopy (SERS) of UA, the quantitative accuracy can be significantly improved without the need for an external internal standard. Due to the influence of the medium, UA, which carries a negative charge, is selectively adsorbed by Au@Ag nanoparticles functionalized with hexadecyltrimethylammonium chloride (CTAC) in this system. Furthermore, a highly convenient detection method was developed, which eliminates the need for pre-processing and minimizes matrix interference by simple dilution. The method was applied to the urine detection of different volunteers, and the results were highly consistent with those obtained using the UA colorimetric kit (UACK). The detection time of SERS was only 30 s, which is 50 times faster than UACK. This quantitative strategy of using urinary creatinine as an internal standard to correct the SERS intensity of uric acid is also expected to be extended to the quantitative detection needs of other biomarkers in urine.

HVT-vectored H7 vaccine protects chickens from lethal infection with the highly pathogenic H7N9 Avian influenza virus.

Since mid-2016, the highly pathogenic H7N9 subtype avian influenza virus (AIV) has threatened both public health and the poultry industry. Although a vaccination strategy has been deemed imperative to manage the virus, the most commonly used inactivated vaccines today are susceptible to interference from maternal antibodies and associated with an over-reliance on humoral immunity. In response, we developed a recombination vaccine with the herpesvirus of turkeys (HVT) as the vector to squeeze HPAI H7N9 and assessed its protective efficiency in immunized chickens. By inserting an enhanced green fluorescent protein (EGFP) expression cassette (i.e., MCMV+EGFP+SV40 polyA) into the HVT065 and HVT066 positions, we obtained the recombinant HVT expressing EGFP (i.e., rHVT-EGFP). Electroporation and EGFP tags improved the efficiency of transfection compared with transfection using expression plasmids without any fluorescent labeling and traditional liposomes. Using limiting dilution analysis and ultrasonic cell disruption techniques, we screened and purified a cell-bound herpes virus based on rHVT-EGFP and consequently constructed a recombinant HVT expressing the hemagglutinin (HA) of H7N9 (i.e., rHVT-H7HA), which was able to proliferate similarly to the parental strain, stably pass for at least 15 generations in vitro, and replicate stably in multiple organs in vivo. After chickens were immunized with rHVT-H7HA, the average antibody titers reached up to 3 log2 at 35 d post-vaccination and remained stable. Those results suggest that rHVT-H7HA can protect chickens against H7N9 with a dose-independent immune protection rate of 90% and significantly reduce the lung virus titer 4 d post-challenge.

Ergodic Measure and Potential Control of Anomalous Diffusion.

In statistical mechanics, the ergodic hypothesis (i.e., the long-time average is the same as the ensemble average) accompanying anomalous diffusion has become a continuous topic of research, being closely related to irreversibility and increasing entropy. While measurement time is finite for a given process, the time average of an observable quantity might be a random variable, whose distribution width narrows with time, and one wonders how long it takes for the convergence rate to become a constant. This is also the premise of ergodic establishment, because the ensemble average is always equal to the constant. We focus on the time-dependent fluctuation width for the time average of both the velocity and kinetic energy of a force-free particle described by the generalized Langevin equation, where the stationary velocity autocorrelation function is considered. Subsequently, the shortest time scale can be estimated for a system transferring from a stationary state to an effective ergodic state. Moreover, a logarithmic spatial potential is used to modulate the processes associated with free ballistic diffusion and the control of diffusion, as well as the minimal realization of the whole power-law regime. The results presented suggest that non-ergodicity mimics the sparseness of the medium and reveals the unique role of logarithmic potential in modulating diffusion behavior.

[Vertical Differences in Grassland Bacterial Community Structure During Non- Growing Season in Eastern Ulansuhai Basin].

Grassland is an important part of the regional ecosystem, and its micro ecological structures play key roles in the process of element migration and the evolution of ecological diversity systems. To discover the spatial difference of the grassland soil bacterial community, we collected five total soil samples at 30 cm depth and 60 cm depth in Eastern Ulansuhai Basin in early May (before the beginning of the new growing season, with a minimum influence of human activities and other factors). Based on 16S rRNA gene-based high-throughput sequencing technology, the vertical characteristic of the bacterial community was analyzed in detail. First, Actinobacteriota, Proteobacteria, Chloroflexi, Acidobacteriota, Gemmatimonadota, Planctomycetota, Methylomirabilota, and Crenarchacota all appeared in the 30 cm and 60 cm samples, with the relative contents all being higher than 1%. In addition, there were a total of six phyla, five genera, and eight OTUs in the 60 cm sample with relative contents higher than those in the 30 cm sample. As a result, the relative abundance changes in dominant bacterial phyla, genera, and even OTUs at different sample depths did not correspond to their contribution to the bacterial community structure. Second, because of the unique contribution to the bacterial community structure in 30 cm and 60 cm samples, the norank_f__norank_o__norank_c__norank_p__Armatimonadota and Candidatus_Xiphinematobacter could be utilized as key bacterial genera during ecological system analysis, belonging to the Armatimonadota and Verrucomicrobiota, respectively. Finally, the relative abundances of ko00190, ko00910, and ko01200 were all higher in 60 cm samples than those in 30 cm samples, which showed that through the increase in metabolic function abundance, the relative contents of C, N, and P elements in grassland soil had been reduced with the increase in depth. These results will provide references for further study on the spatial change of bacterial communities in typical grassland.

Reviews of fungi and mycotoxins in Chinese dark tea.

The fermentation is the main process to form the unique flavor and health benefits of dark tea. Numerous studies have indicated that the microorganisms play a significant part in the fermentation process of dark tea. Dark tea has the quality of "The unique flavor grows over time," but unscientific storage of dark tea might cause infestation of harmful microorganisms, thereby resulting in the remaining of fungi toxins. Mycotoxins are regarded as the main contributor to the quality of dark tea, and its potential mycotoxin risk has attracted people's attention. This study reviews common and potential mycotoxins in dark tea and discusses the possible types of masked mycotoxins in dark tea. A summary of the potential risks of mycotoxins and masked mycotoxins in dark tea is presented, intending to provide a reference for the prevention and risk assessment of harmful fungi in dark tea.

Prevalence and molecular characterization of Clostridioides difficile infection in China over the past 5 years: a systematic review and meta-analysis.

OBJECTIVES: The aim of this study was to provide an overview of the prevalence and molecular characteristics of Clostridioides difficile infection (CDI) in China in the past 5 years. METHODS: A systematic literature review was conducted according to the preferred reporting items for systematic reviews and meta-analyses guidelines. Nine databases were searched for relevant studies published between January 2017 and February 2022. The Joanna Briggs Institute critical appraisal tool was used to assess the quality of included studies, and R software version 4.1.3 was used for data analysis. Funnel plots and Egger regression tests were also performed to assess publication bias. RESULTS: A total of 50 studies were included in the analysis. The pooled prevalence of CDI in China was 11.4% (2696/26,852). The main circulating C. difficile strains in southern China were ST54, ST3, and ST37, consistent with the overall situation in China. However, the most prevalent genotype in northern China was ST2, which was previously underappreciated. CONCLUSION: Based on our findings, increased awareness and management of CDI is necessary to reduce the prevalence of CDI in China.

Untargeted metabolomics and quantification analysis reveal the shift of chemical constituents between instant dark teas individually liquid-state fermented by Aspergillus cristatus, Aspergillus niger, and Aspergillus tubingensis.

Instant dark teas (IDTs) were individually liquid-state fermented using the fungi Aspergillus cristatus, Aspergillus niger, and Aspergillus tubingensis. To understand how the chemical constituents of IDTs were affected by the fungi, samples were collected and measured by liquid chromatography-tandem mass-tandem mass spectrometry (LC-MS/MS). Untargeted metabolomics analysis revealed that 1,380 chemical constituents were identified in positive and negative ion modes, and 858 kinds of chemical components were differential metabolites. Through cluster analysis, IDTs were different from the blank control, and their chemical constituents mostly included carboxylic acids and their derivatives, flavonoids, organooxygen compounds, and fatty acyls. And the metabolites of IDTs fermented by A. niger and A. tubingensis had a high degree of similarity and were classified into one category, which showed that the fungus used to ferment is critical to the formation of certain qualities of IDTs. The biosynthesis of flavonoids and phenylpropanoid, which involved nine different metabolites such as p-coumarate, p-coumaroyl-CoA, caffeate, ferulate, naringenin, kaempferol, leucocyanidin, cyanidin, and (-)-epicatechin, were significant pathways influencing the quality formation of IDTs. Quantification analysis indicated that the A. tubingensis fermented-IDT had the highest content of theaflavin, theabrownin, and caffeine, while the A. cristatus fermented-IDT had the lowest content of theabrownin, and caffeine. Overall, the results provided new insights into the relationship between the quality formation of IDTs and the microorganisms used in liquid-state fermentation.

Neutralizing peripheral circulating IL1ß slows the progression of ALS in a lentivirus-infected OPTNE478G mouse model.

BACKGROUND: Amyotrophic lateral sclerosis (ALS) is irreversible and fatal within 3-5 years, with limited options for treatment. It is imperative to develop a symptom-based treatment that may increase the survival of ALS patients and improve their quality of life. Inflammation status, especially elevated interleukin 1ß (IL1ß), has been reported to play a critical role in ALS progression. Our study determined that neutralizing circulating IL1ß slows down the progression of ALS in an ALS mouse model. METHODS: The ALS mouse model was developed by microinjection of lentivirus-carrying OPTNE478G (optineurin, a mutation from ALS patients) into the intra-motor cortex of mice. Peripheral circulating IL1ß was neutralized by injecting anti-IL1ß antibody into the tail vein. Enzyme-linked immunosorbent assay (ELISA) and real-time polymerase chain reaction (RT-PCR) were carried out to determine the protein and gene expression levels of IL1ß. TUNEL assay was used to assess the neural cell death. Immunofluorescent staining of MAP2 and CASP3 was accomplished to evaluate neuronal cell apoptosis. Glial fibrillary acidic protein staining was performed to analyze the number of astrocytes. Rotarod test, grip strength test, balance beam test, and footprint test were conducted to assess the locomotive function after anti-IL1ß treatment. RESULTS: The model revealed that neuroinflammation contributes to ALS progression. ALS mice exhibited elevated neuroinflammation and IL1ß secretion. After anti-IL1ß treatment, ALS mice revealed decreased neural cell death and astrogliosis and gained improved muscle strength and motor ability. CONCLUSIONS: Blocking IL1ß is a promising strategy to slow down the progression of ALS.

Characterizing emotion profiles in non-clinical population: A cluster analytical study.

Emotion processing and beliefs about pleasure can influence the development and severity of depressive symptoms. This cluster analysis study aimed to profile a large sample of college students using pleasure experience, emotion expression and regulation as well as beliefs about pleasure. We also aimed to validate the resultant clusters in terms of depressive symptoms. A set of checklists capturing beliefs about pleasure and the three facets of emotion processing was administered to 1028 college students. A two-stage cluster analysis was used to analyze the profile of these emotional aspects in these college students. Our results showed that a three-cluster solution best fit the data. Cluster 1 (n = 536) was characterized by moderate levels of beliefs about pleasure, pleasure experience, emotion expression, and regulation; Cluster 2 (n = 402) was characterized by generally high levels of beliefs about pleasure, pleasure experience, emotion expression, and regulation; Cluster 3 (n = 90) was characterized by relatively low levels of beliefs about pleasure, pleasure experience, emotion expression, and regulation. The three clusters differed significantly in the severity of depressive symptoms. Our findings suggest the existence of three emotional subtypes, which may be useful in early detection of youth at risk of developing depression.

In vitro inhibition of carnosic acid against influenza A virus infections / 药学学报

Carnosic acid (CA) is the main phenolic diterpenoid active ingredient in plants such as rosemary and sage, and has antiviral, antioxidant, anti-inflammatory effects and so on, however, its antiviral activity against influenza virus infections was not reported. In this study, antiviral activities against influenza A virus infections of three main bioactive ingredients from rosemary, including rosmarinic acid, CA and ursolic acid, were evaluated using virus titer titration assay, and CA showed remarkable inhibition on influenza H5N1 replication in A549 cells. The antiviral activity of CA was further confirmed and its mechanism of action was investigated using the indirect immunofluorescence assay (IFA), Western blot and real-time fluorescence quantification polymerase chain reaction (qRT-PCR). The results showed that the 50% effective concentration (EC50) of CA against influenza H5N1 in A549 cells and MDCK cells were 4.30 and 3.64 μmol·L-1, respectively. Meanwhile, CA also showed inhibition on influenza virus 2009panH1N1 (EC50: 10.1 μmol·L-1) and H3N2 (EC50: 12.8 μmol·L-1) replications in A549 cells. Mechanistic studies showed that antiviral activity of CA is related to its induction of heme oxygenase-1 (HO-1) in A549 cells and suppression on production of reactive oxygen in H5N1-infected cells.

Triaging patients in the outbreak of COVID-2019 / 中国感染控制杂志

In the outbreak of COVID-19,triage procedures based on epidemiology were implemented in a local hospital in Changsha to control the transmission of SARS-CoV-2 and avoid healthcare-associated infection.This re-trospective study analyzed the data collected during the triage period and found that COVID-19 patients were en-riched 7 folds into the Section A designated for patients with obvious epidemiological history.On the other side,nearly triple amounts of visits were received at the Section B for patients without obvious epidemiological history.8 COVID-19 cases were spotted out of 247 suspected patients.More than 50％of the suspected patients were submi-tted to multiple rounds of nucleic acid analysis for SARS-CoV-2 infection.Of the 239 patients who were diagnosed as negative of the virus infection,188 were successfully revisited and none was reported as COVID-19 case.Of the 8 COVID-19 patients,3 were confirmed only after multiple rounds of nucleic acid analysis.Besides comorbidities,delayed sharing of epidemiological history added complexity to the diagnosis in practice.The triaging experience and strategy will be helpful for the control of infectious diseases in the future.

Calcitriol increases MBNL1 expression and alleviates myotonic dystrophy phenotypes in HSALR mouse models.

BACKGROUND: Myotonic dystrophy type 1 (DM1), one of the most common forms of adult-onset muscular dystrophy, is caused by abnormally expanded CTG repeats in the 3' untranslated region of the DMPK gene. The CUG repeats transcribed from the expanded CTG repeats sequestrate a splicing factor, MBNL1, causing the clinical symptoms in DM1. Nowadays, only symptomatic treatments are available for DM1, and no rational therapy is available. Recently, upregulation of MBNL1 expression has been found to be one of the promising therapies for DM1. METHODS: All experiments were conducted in the C2C12 myoblasts and HSALR mice, a DM1 mouse model. Real-time PCR and western blot were used to detect the mRNA and protein level, respectively. The rotarod exercise, grip strength and hanging time were used to evaluate the muscle strength of mice. RESULTS: In this study, we demonstrated that calcitriol, an active form of vitamin D3, increased MBNL1 in C2C12 mouse myoblasts as well as in HSALR mice model for DM1. In HSALR mice model, calcitriol improved muscle strength, and corrected aberrant splicing in skeletal muscle. Besides, calcitriol reduced the number of central nuclei, and improved muscle histopathology in HSALR mice. In addition, we identified that calcitriol upregulated MBNL1 expression via activating the promoter of Mbnl1 in C2C12 myogenic cells. CONCLUSION: Our study suggests that calcitriol is a potential pharmacological strategy for DM1 that enhances MBNL1 expression.

Quantitatively Revealing the Anomalous Enhancement in Shell-Isolated Nanoparticle-Enhanced Raman Spectroscopy Using Single-Nanoparticle Spectroscopy.

Surface-enhanced Raman spectroscopy (SERS) is an ultrasensitive spectroscopic technique that has been extensively applied in the studies of catalysis, electrochemistry, material science, etc.; however, it is substrate and material limited. The development of shell-isolated nanoparticle-enhanced Raman spectroscopy (SHINERS) effectively offsets this limitation that attracts enormous attention due to its potential to be applied to any surface. As the core of the SHINERS technique, the inert shell prevents the exposure of the active metal surface, however, also significantly enlarges the metallic gap where the light is trapped. Consequently, the shell is widely considered a side issue to debilitate the coupling efficiency and hinder the sensitivity of SHINERS without systematic studies. Herein, we investigate the shell and structural effect of SHINERS by performing the quantitative optical and structural characterization of single nanostructures. By a statistic of over two hundred nanostructures, we observe that the field enhancement loss due to the shell could be overcome by optimizing the coupling geometry of the shell-isolated nanoparticles (SHINs). An example of SHIN dimers shows even higher field enhancement than their bare Au nanoparticle counterparts as confirmed and explained by FDTD simulations. We demonstrate the signal enhancement of SHINERS saturates with the increasing number of hot spots but could be further optimized by altering the aggregation geometries of the nanoparticles. The sensitivity improvement of the SHINERS technique will boost its broader applications in material science.

Dietary assessment of ochratoxin A in Chinese dark tea and inhibitory effects of tea polyphenols on ochratoxigenic Aspergillus niger.

In recent years, there has been an increasingly heated debate on whether Chinese dark tea is contaminated with mycotoxins and whether it poses health risks to consumers. In this study, a rapid method based on high-performance liquid chromatography was used to detect ochratoxin A (OTA) in Chinese dark tea samples from different regions of China and different years. Of the 228 Chinese dark tea samples tested, 21 were detected for OTA contamination, with a concentration ranging from 2.51 ± 0.16 to 12.62 ± 0.72 µg/kg. Subsequently, a dark tea drinking risk assessment was conducted, and the hazard quotient for each group was far below the acceptable level of 1.0. Of the 12 Aspergillus spp. strains isolated, one strain of Aspergillus niger had the ability to produce OTA. We also found that tea polyphenols and epigallocatechin gallate inhibited the growth of ochratoxin-producing Aspergillus niger and the expression of non-ribosomal peptide synthetase (NRPS), a key gene for ochratoxin synthesis. Thus, OTA contamination of dark tea is at an acceptable risk level, and the inhibition of ochratoxigenic Aspergillus niger by polyphenols provides new insights into the safety of dark tea consumption.

Ultrafast and field-based detection of methamphetamine in hair with Au nanocake-enhanced Raman spectroscopy.

The disaster and devastation from abuse of Methamphetamine (MAMP) have a serious impact on people's mental and physical health. Developing a rapid and accurate method to screen drug suspects and thus control MAMP abuse is essential to social security. Hair analysis for MAMP detection is considered to be one of the most potential methods for monitoring drug abuse due to its convenient sample collection, easy for storage and long traceability period. However, the current accurate detection of MAMP in hair primarily utilizes hyphenated mass spectrometry (MS) techniques, but it is not suitable for field-based detection due to the bulky instrument. Hence, developing alternative portable detection techniques for rapid on-site detection of MAMP in hair is an urgent problem to be solved. Here, the high-performance Au nanocakes (Au NCs) were constructed as surface-enhanced Raman spectroscopy (SERS) substrates to detect MAMP in hair, realizing 5 min ultrafast and ultrasensitive detection utilizing a portable Raman spectrometer. Experiments and finite-difference time-domain (FDTD) simulations show that Au NCs have stronger enhancement than Au nanospheres (Au NPs), and 0.5 ppb (3.35 × 10-9 M) MAMP standard is stably detected by Au NCs as an enhanced substrate. A strategy of liquid-liquid microextraction was exploited to eliminate the interference of complex matrices in hair. This method exhibited excellent reproducibility and temporal stability across different drug addicts (relative standard deviation was 5.14% within 160 s). Our approach shows great promise in public safety, providing a rapid and accurate method to detect in hair by SERS.