Background Kurtosis reflecting noise's temporal structure is an effective metric for evaluating noise-induced hearing loss (NIHL), and its threshold is still unclear. Objective To explore the energy range of kurtosis and the threshold of NIHL induced by kurtosis in this energy rangeMethods Using cross-sectional design, 4631 noise-exposed workers in manufacturing industry were selected. The hearing loss and noise exposure data of each worker were collected. Logistic regression model was used to establish the dose-response relationship between noise exposure and hearing loss and estimate the range of energy effects. Restricted cubic spline model was utilized to analyze the dose-response relationship curves of kurtosis to noise-induced hearing loss (NIHI) and high-frequency noise-induced hearing loss (HFNIHL) under different 8 h equivalent sound levels (L_{EX,8 h}), as well as to estimate the kurtosis effect threshold. Results The logistic regression model analysis showed that the prevalence of NIHI and HFNIHL increased significantly with increase of L_{EX,8 h} for steady noise; when L_{EX,8 h} of non-steady noise was 80-100 dB(A), the risk of hearing loss increased with an increase in kurtosis (P<0.05). The restricted cubic spline model showed that when L_{EX,8 h} of non-steady noise was 0-80 dB(A) or >100 dB(A), there was no significant relationship between kurtosis and NIHI or HFNIHL. When L_{EX,8 h} was 80-100 dB(A), there was a significant nonlinear dose-response relationship between kurtosis and NIHL or HFNIHL (P <0.001), and kurtosis > 28.08 exerted effect in elevating NIHI or HFNIHL. Conclusion The effect threshold of kurtosis on NIHL is 28.08 when non-steady noise levels are in the range of 80-100 dB(A). The effect threshold of kurtosis needs further verification.

T7 RNA polymerase (T7 RNAP) is one of the simplest known RNA polymerases. Its unique structural features make it a critical model for studying the mechanisms of RNA synthesis. This review systematically examines the static crystal structure of T7 RNAP, beginning with an in-depth examination of its characteristic “thumb”, “palm”, and “finger” domains, which form the classic “right-hand-like” architecture. By detailing these structural elements, this review establishes a foundation for understanding the overall organization of T7 RNAP. This review systematically maps the functional roles of secondary structural elements and their subdomains in transcriptional catalysis, progressively elucidating the fundamental relationships between structure and function. Further, the intrinsic flexibility of T7 RNAP and its applications in research are also discussed. Additionally, the review presents the structural diagrams of the enzyme at different stages of the transcription process, and through these diagrams, it provides a detailed description of the complete transcription process of T7 RNAP. By integrating structural dynamics and kinetics analyses, the review constructs a comprehensive framework that bridges static structure to dynamic processes. Despite its advantages, T7 RNAP has a notable limitation: it generates double-stranded RNA (dsRNA) as a byproduct. The presence of dsRNA not only compromises the purity of mRNA products but also elicits nonspecific immune responses, which pose significant challenges for biotechnological and therapeutic applications. The review provides a detailed exploration of the mechanisms underlying dsRNA formation during T7 RNAP catalysis, reviews current strategies to mitigate this issue, and highlights recent progress in the field. A key focus is the semi-rational design of T7 RNAP mutants engineered to minimize dsRNA generation and enhance catalytic performance. Beyond its role in transcription, T7 RNAP exhibits rapid development and extensive application in fields, including gene editing, biosensing, and mRNA vaccines. This review systematically examines the structure-function relationships of T7 RNAP, elucidates the mechanisms of dsRNA formation, and discusses engineering strategies to optimize its performance. It further explores the engineering optimization and functional expansion of T7 RNAP. Furthermore, this review also addresses the pressing issues that currently need resolution, discusses the major challenges in the practical application of T7 RNAP, and provides an outlook on potential future research directions. In summary, this review provides a comprehensive analysis of T7 RNAP, ranging from its structural architecture to cutting-edge applications. We systematically examine: (1) the characteristic right-hand domains (thumb, palm, fingers) that define its minimalistic structure; (2) the structure-function relationships underlying transcriptional catalysis; and (3) the dynamic transitions during the complete transcription cycle. While highlighting T7 RNAP’s versatility in gene editing, biosensing, and mRNA vaccine production, we critically address its major limitation—dsRNA byproduct formation—and evaluate engineering solutions including semi-rationally designed mutants. By synthesizing current knowledge and identifying key challenges, this work aims to provide novel insights for the development and application of T7 RNAP and to foster further thought and progress in related fields.

Aim To establish a stable hepatic stellate cell ( HSC ) -specific G protein-coupled receptor kinase 2 ( GRK2 ) knockout mice and provide the important animal model for further studying the biological function of GRK2 in HSC. Methods The loxP-labeled Grk2 gene mouse (Grk2

Natural products are important sources for the discovery of anti-tumor drugs. Evodiamine is the main alkaloid component of the traditional Chinese herb Wu-Chu-Yu, and it has weak antitumor activity. In recent years, a number of highly active antitumor candidates have been discovered with a significant progress. This article reviews the research progress of evodiamine-based antitumor drug design strategies, in order to provide reference for the development of new drugs with natural products as leads.

Objective We aimed to investigate the effects of Biejiajian Pills on MHCC-97H hepatoma cells and whether Biejiajian Pills regulate the epidermal growth factor receptor (EGFR)/mitogen-activated protein kinase (MAPK)/extracellular signal-regulated kinase (ERK) signaling pathway through miR-885-5p.Methods SPF SD rats (n = 10) were randomly divided into the blank group and the Biejiajian Pills (1.1 g/kg) group to prepare blank and Biejiajian Pills-containing serum. MHCC-97H cells in the logarithmic growth phase were divided into the model group, blank serum groups with different concentrations (5％, 10％, 15％, and 20％), the serum containing Biejiajian Pills group, and the blank group without cells. Cell proliferation was detected by the CCK-8 assay, and the optimal intervention time and concentration of drug-containing serum were screened. MHCC-97H cells were divided into the blank control group (no intervention), the Biejiajian Pills-containing serum group (20％ Biejiajian Pills-containing serum), the miR-885-5p mimics group (transfected with miR-885-5p mimics), the miR-NC group (transfected with miR-885-5p NC), and the Biejiajian Pills-containing serum + miR-885-5p mimics group (treated with 20％ Biejiajian Pills-containing serum and transfected with miR-885-5p mimics). Cells in each group were cultured for 72 hours. A dual luciferase reporter assay was conducted to verify the targeting relationship between miR-885-5p and EGFR. Cell proliferation was detected by the CCK-8 assay, cell migration and invasion abilities were detected by the cell scratch assay and the Transwell invasion assay. Annexin V-APC/PI double staining was performed to detect the apoptosis level, and real-time fluorescence quantitative PCR (RT-qPCR) analysis was conducted to determine the mRNA expression levels of miR-885-5p, EGFR, MEK, and ERK1/2. The expression levels of EGFR, p-EGFR, MEK, p-MEK, ERK1/2, p-ERK1/2, matrix metalloproteinase 1 (MMP1), and CyclinD1 were determined by Western blotting analysis. The subcutaneous tumor model of MHCC-97H hepatoma cells in nude mice was established by subcutaneous injection to observe the inhibitory effect of Biejiajian Pills of different doses(0.55,1.1,2.2 g/kg).Results The optimal concentration and intervention time of Biejiajian Pills-containing serum were 20％ and 72 hours, respectively. Meanwhile, the dual luciferase reporter assay showed that miR-885-5p could directly target EGFR. No statistical significances between the blank control group and the miR-NC group were observed (P>0.05). Compared with the blank control group, the proliferation rates of MHCC-97H hepatoma cells in the Biejiajian Pills-containing serum group, the miR-885-5p mimics group, and the Biejiajian Pills-containing serum + miR-885-5p mimics group were significantly decreased (P<0.01), and their migration and invasion abilities were significantly decreased (P<0.05, P<0.01). At the same time, the protein expression levels of CyclinD1 and MMP1, which are closely related to cell proliferation and invasion, were significantly downregulated (P<0.05, P<0.01). The proportions of late apoptotic cells and the proportion of total apoptotic cells were significantly increased (P<0.01). In the Biejiajian Pills-containing serum group, the miR-885-5p mimics group, and the Biejiajian Pills-containing serum + miR-885-5p mimics group, miR-885-5p mRNA was significantly upregulated (P<0.01) and EGFR, MEK, and ERK1/2 were significantly downregulated at the mRNA level (P<0.05, P<0.01). EGFR, MEK, and ERK1/2 phosphorylation was inhibited (P<0.01), and the Biejiajian Pills-containing serum + miR-885-5p mimics group showed the best effect (P<0.05, P<0.01). The subcutaneous liver tumor model in nude mice verified that Biejiajian Pills can inhibit tumor growth in a dose-dependent manner. Conclusion Biejiajian Pills can promote apoptosis of MHCC-97H hepatoma cells and inhibit their proliferation, invasion, and migration. The mechanism may be related to the targeted regulation of the EGFR/MAPK/ERK signaling pathway by miR-885-5p.

Polyunsaturated fatty acids (PUFAs) have diverse health-promoting effects, such as potentially protecting in immune, nervous, and cardiovascular systems by targeting a variety of sites, including most ion channels. Voltage-gated potassium channels of the K_V7 family and large-conductance Ca²⁺- and voltage-activated K⁺ (BK_Ca) channels are expressed in many tissues, therefore, their physiological importance is evident from the various disorders linked to dysfunctional K_V7 channels and BK_Ca channels. Thus, it is extremely important to learn how potassium channels are regulated by PUFAs. The aim of this review is to provide an overview of the effects of PUFAs on K_V7 channels and BK_Ca channels functions, as well as the mechanisms underlying these effects. In summarizing reported effects of PUFAs on K_V7 and BK_Ca channels mediated currents, we generally conclude that PUFAs increase the current amplitude, meanwhile, differential molecular and biophysical mechanisms are associated with the current increase. In K_V7 channels the currents increasement are associated with a shift in the voltage dependence of channel opening and increased maximum conductance in K_V7 channels, while in BK_Ca channels, they are associated with destabilization the pore domain closed conformation. Furthermore, PUFA effects are influenced by auxiliary subunits of K_V7 and BK_Ca channels, associate with channels in certain tissues. although findings are conflicting. A better understanding of how PUFAs regulate K_V7 and BK_Ca channels may offer insight into their physiological regulation and may lead to new therapeutic strategies and approaches.

Objective To evaluate the bioequivalence of oral sidenafil citrate tablets manufactured(100 mg)test preparations and reference preparations in healthy subjects under fasting and fed conditions.Methods Using a single-dose,randomized,open-lable,two-period,two-way crossover design,36 healthy subjects respectively for fasting and fed study were enrolled,and randomized into two groups to receive a single dose of test 100 mg with 7-day washout period.Plasma concentration of sidenafil and N-demethylsildenafil was determined by liquid chromatography-tandem mass spectrometry(LC-MS/MS)method.The pharmacokinetic parameters were calculated by Analyst 1.6.3(AB Scie)using non-compartmental model,and bioequivalence evaluation was performed for the two preparations.Relevant safety evaluations were performed during the trial.Results The main pharmacokinetic parameters of sidenafil after a single oral dose of sidenafil citrate tablets under fasting condition for test and reference were as follows:Cmax were(494.69±230.94)and(558.78±289.83)ng·mL-1,AUC0-t were(1 336.21±509.78)and(1 410.82±625.99)h·ng·mL-1,AUC0-were(1 366.49±512.16)and(1 441.84±628.04)h·ng·mL-1,respectively.The main pharmacokinetic parameters of sidenafil under fed condition for T and R were as follows:Cmax were(381.89±126.53)and(432.47±175.91)ng·mL-1,AUC0-t were(1 366.34±366.99)and(1 412.76±420.37)h·ng·mL-1,AUC0-were(1 403.28±375.32)and(1 454.13±429.87)h·ng·mL-1,respectively.The results demonstrated the bioequivalence of sidenafil citrate tablets between T and R.The incidence of adverse events in fasting and fed tests were 33.33％and 25.00％,respectively.No serious adverse event was reported.Conclusion The test and reference formulation of sidenafil citrate tablets were equivalent and was safe.

Objective To investigate the inhibitory effects of Wumeiwan on oxidative stress injury of ulcerative colitis mice induced by dextran sulfate sodium(DSS)by regulating Kelch-like ECH related protein 1(Keap-1)-nuclear factor E2 related factor 2(Nrf2)/heme oxygenase-1(HO-1)signaling pathwayand.Methods Forty C57BL/6 mice were randomly divided into five groups:normal group,model group,positive control group,experimental-L,-H groups.UC mice model were induced by free access to 2％DSS water.Mice in normal and model group were orally administered with 0.9％NaCl,mice in positive control group were orally treated with Mesalazine solution(0.005 g·10 g-1·d-1),while mice in experimental groups were orally administered with Wumeiwan decoction at the dose of 0.13 and 0.26 g·10 g-1·d-1,respectively.All the drugs were administered for consecutive 7 days,1 times a day.The levels of disease activity index(DAI)and the colon length were scored.The levels of superoxide dismutase(SOD),catalase(CAT),cyclooxygenase-2(COX-2)and inducible nitric oxide synthase(iNOS)in colon tissue of mice were determined by real-time fluorescence quantitative polymerase chain reaction(qRT-PCR)method.The level of Keap-1,Nrf2,HO-1 proteins in colon tissue were determined by Western blot method.Results The levels of DAI of seventh day in normal group,positive control group,experimental-L,-H groups were 0、(2.62±0.33),(1.87±0.35),(1.87±0.35)and(1.58±0.35);the colon lengths were(8.16±0.47)、(5.98±0.24),(7.58±0.38),(7.33±0.24)and(7.48±0.51)cm;the SOD mRNA were 1.01±0.16、0.40±0.01,1.43±0.45,0.65±0.01 and 0.83±0.02;the CAT mRNA were 1.01±0.20、0.45±0.01,0.84±0.02,0.68±0.07 and 0.87±0.05;the COX-2 mRNA were 1.03±0.33、16.65±0.60,4.78±0.25,14.07±0.60 and 7.39±0.15;the iNOS mRNA were 1.04±0.40、20.71±0.66,8.09±0.93,15.44±0.68 and 11.66±0.06;the levels of Keap-1 were 1.22±0.16、1.10±0.05,1.18±0.05,1.94±0.08 and 1.17±0.08;the levels of Nrf2 were 1.12±0.16、0.76±0.15,0.65±0.13,0.70±0.16 and 0.82±0.18;the levels of HO-1 were 1.34±0.15、1.00±0.12,0.89±0.10,1.50±0.18 and 1.40±0.13,respectively.Significant difference was found between normal group and model group(P＜0.01,P＜0.05);significant difference was also found between the experimental-L,-H groups and model group(P＜0.01,P＜0.05).Conclusion Wumeiwan can inhibit oxidative stress in mice with UC,the mechanisms may be related to adjusted the expression of Keap-1-Nrf2/HO-1 signaling pathway protein in colon.

Objective To construct machine learning models that can be used to predict AUC fold change(FC)using a database of existing pharmacokinetic(PK)and drug-drug interaction(DDI)information,which can be used to explore the possibility of predicting existing drug interactions and to provide certain rational recommendations for clinical drug use.Methods PK data of DDIs and AUC fold change data were extracted from FDA-approved drug labels.Peptide and pharmacodynamic(PD)information related to drug interactions were retrieved through DrugBank,and PPDT identification of relevant peptide IDs was performed using Protein Resource(UniProt),and a matrix normalization code was used to generate multidimensional vector data that were easy to analysis.The effect of PPDT on the AUC,and the resulting multiplicity change was used as the dependent variable for machine learning model construction.The model with the smallest root mean square error(RMES)value was used for model construction to train a bagged decision tree(Bagged)prediction model.The models were tested using the trained models for some of the drug tests.The models were evaluated by reviewing the available literature findings on detection of drug interaction pairs and analyzing and comparing the predicted values.Results A total of 16 pairs of model drug pairs were tested for the effects of 16 drugs on tacrolimus,and it was found that the accuracy of the prediction of the presence or absence of drug interactions was 81.25％;the prediction results were classified according to the FDA standard classification of the strong and weak for the strength of drug interactions,and the results showed that the prediction of the strength of drug interactions,with a large deviation from the larger prediction was less.Conclusion The evaluation of the model to predict the presence or absence of drug interactions was general;however,after classifying the strengths and weaknesses of drug interactions,the prediction of drug interactions was better,and the prediction results indicated that the model prediction performance has a certain reference value for potential DDI assessment before clinical trials.

Therapeutic mRNA vaccine for tumors attracted much attention as a new type of tumor treatment,and most products are in the preclinical and clinical research stage,and there has not post-market drug.However,the non-clinical evaluation of therapeutic mRNA vaccines for tumors is more complicated,due to their target features,mechanisms,delivery patterns,and the cross-species differences of immune system.The choice of animal model is not only content of the clinical effectiveness,and it was a key factor of toxicity assessment.In this work,the challenges for non-clinical evaluation of therapeutic mRNA vaccines for tumors are discussed,and the compliant requirements are reviewed,and the general considerations are suggested.