Mitochondria, functioning not only as the central hub of cellular energy metabolism but also as semi-autonomous organelles, orchestrate cellular fate decisions through their endogenous mitochondrial DNA (mtDNA), which encodes core components of the electron transport chain. Emerging research has identified microRNAs localized within mitochondria, termed mitochondria-located microRNAs (mitomiRs). Recent studies have revealed that mitomiRs are transcribed from nuclear DNA (nDNA), processed and matured in the cytoplasm, and subsequently transported into mitochondria. mitomiRs regulate mtDNA through diverse mechanisms, including modulation of mtDNA expression at the translational level and direct binding to mtDNA to influence transcription. Aberrant expression of mitomiRs leads to mitochondrial dysfunction and contributes to the pathogenesis of metabolic diseases. Restoring mitomiR expression to physiological levels using mitomiRs mimics or inhibitors has been shown to improve mitochondrial function and alleviate related diseases. Consequently, the regulatory mechanisms of mitomiRs have become a major focus in mitochondrial research. Given that mitomiRs are located in mitochondria, targeted delivery strategies designed for mtDNA can be adapted for the delivery of mitomiRs mimics or inhibitors. However, numerous intracellular and extracellular barriers remain, highlighting the need for more precise and efficient delivery systems in the future. The regulation of mtDNA expression mediated by mitomiRs not only expands our understanding of miRNA functions in post-transcriptional gene regulation but also provides promising molecular targets for the treatment of mitochondrial-related diseases. This review systematically summarizes recent research progress on mitomiRs in regulating mtDNA expression and discusses the underlying mechanisms of mitomiRs-mtDNA interactions. Additionally, it provides new perspectives on precision therapeutic strategies, with a particular emphasis on mitomiRs-based regulation of mitochondrial function in mitochondrial-related diseases.

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.

Objective To investigate the clinical efficacy of Lianhua Qingyou Decoction combined with acupuncture in the treatment of Helicobacter pylori(Hp)-infected chronic atrophic gastritis(CAG),and to observe the effect on gastrointestinal function.Methods Ninety-eight patients with Hp-infected CAG of heat stagnation in the liver and stomach type were randomly divided into a study group and a control group,with 49 patients in each group.The control group was treated with standard anti-Hp quadruple therapy,and the study group was treated with Lianhua Qingyou Decoction combined with acupuncture on the basis of treatment for the control group.The treatment course for the two groups covered 12 weeks.Before and after the treatment,the two groups were observed in the scores of pathohistological changes in the gastric mucosal atrophy,intestinal epithelial hyperplasia,inflammatory response,activity and Hp infection,gastrointestinal function indicators of serum gastrin,motilin,vasoactive intestinal peptide(VIP),and somatostatin,and the levels of pepsinogens of PGⅠand PGⅡ.After treatment,the clinical efficacy and Hp negative-conversion rate in the two groups were compared.Results(1)After 12 weeks of treatment,the total effective rate in the study group was 95.92%(47/49)and that in the control group was 73.47%(36/49),and the intergroup comparison(by chi-square test)showed that the therapeutic efficacy of the study group was significantly superior to that of the control group(P＜0.01).(2)After treatment,the scores of pathohistological changes in the gastric mucosal atrophy,intestinal epithelial hyperplasia,inflammatory response,activity and Hp infection in the two groups were decreased compared with those before treatment(P＜0.05),and the decrease in the study group was significantly superior to that in the control group(P＜0.01).(3)After treatment,the serum levels of gastrointestinal function indicators of gastrin,motilin and somatostatin in the two groups were all higher than those before treatment(P＜0.05),and the serum VIP level was lower than that before treatment(P＜0.05).The increase in the serum gastrin,motilin and somatostatin levels and the decrease in the serum VIP level of the study group were significantly superior to those of the control group(P＜0.01).(4)After treatment,the serum pepsinogen levels of PGⅠ and PGⅡ in the two groups were higher than those before treatment(P＜0.05),and the increase in the study group was significantly superior to that in the control group(P＜0.01).(5)The Hp negative-conversion rate of the study group was 95.92%(47/49),which was significantly higher than that of the control group(79.59%,39/49)and the difference was statistically significant(χ2 = 6.078,P = 0.014).Conclusion For the treatment of patients with Hp-infected CAG of heat stagnation in the liver and stomach type,Lianhua Qingyou Decoction combined with acupuncture can effectively enhance the clinical efficacy and Hp negative-conversion rate,improve the pathohistological scores and gastrointestinal function,and regulate the serum PGⅠand PGⅡlevels.

Objective To compare the clinical characteristics,peripheral blood inflammatory cells and levels of oxidative stress indicators between severe asthma and non-severe asthma patients,analyze the effects of neutrophils and oxidative stress molecules on the severity of asthma,and build a biological model for early prediction of severe asthma.Methods From Aug 2018 to Jul 2019,67 adult patients with stable asthma in our hospital were enrolled in this study.The clinical characteristics,peripheral blood inflammatory cells and levels of oxidative stress indicators of severe asthma group and non-severe asthma group were compared.Single factor Logistic regression analysis was conducted on severe asthma to screen out the most important five variables.Multifactor Logistic regression analysis was further conducted to establish a prediction model for severe asthma.Results There were 25 severe asthma patients in this cohort,who had a longer course of disease,more frequent acute attacks,poorer asthma control,higher peripheral neutrophils,more severe obstructive ventilation dysfunction,lower myeloperoxidase(MPO)level and higher superoxide dismutase(SOD)than non-severe asthma patients.The patients with higher peripheral blood neutrophil count or proportion were more likely to show severe asthma,more frequent acute attacks,and more obvious reduction of pulmonary ventilation function.A panel of biomarkers,centered on peripheral blood neutrophil count and oxidative stress indicators SOD,human 8-epi-prostaglandin F2α(8-iso-PGF2α),could build a model to predict severe asthma.Conclusion There are significant differences in clinical characteristics,peripheral blood inflammatory cells,and oxidative stress index levels between severe asthma patients and non-severe asthma patients.In stable asthma patients,levels of neutrophils and oxidative stress indicators such as SOD had an impact on the severity of asthma.The prediction model of severe asthma established on this basis provides a new idea for early recognition of severe asthma.

Objective To analyze the influencing factors for catheter-associated infection(CAI)in chemotherapy treated patients after indwelling peripherally inserted central catheter(PICC)based on a random forest model.Methods 400 tumor patients who received chemotherapy and PICC were selected and divided into the training set(n=300)and the test set(n=100)in a 3∶1 ratio through computer-generated random number.Patients in the training set were subdivided into the non-infection group and the infection group based on the occurrence of infec-tion.Clinical data from two groups of patients were compared.Influencing factors for the occurrence of CAI after PICC were analyzed with multivariate logistic regression model and the integrated classification algorithm of random forest model,and the predictive performance of the two methods was compared.Results Among 300 chemotherapy treated patients in the training set,32 cases(10.67％)experienced CAI.Compared with the non-infection group,patients in the infection group had more single punctures for catheterization,longer PICC retention time,larger pro-portion of catheter movement,larger proportion of complication with diabetes,higher frequency of dressing chan-ges,lower white blood cell count and immune function(all P＜0.05).PICC retention time,catheter movement,complication with diabetes,dressing change frequency,white blood cell(WBC)and immune function were inde-pendent influencing factors for CAI after PICC(all P＜0.05).The random forest model showed that ranking by the importance of different influencing factors was as following:PICC retention time,catheter movement,complication with diabetes,WBC,dressing change frequency and immune function.The integrated classification algorithm of random forest model for predicting the occurrence of CAI in chemotherapy treated patients showed that the area un-der the receiver operating characteristic(ROC)curve(AUC)was 0.872,which had better prediction performance compared with the logistic regression model(AUC=0.791).Conclusion PICC retention time,catheter movement,complicated with diabetes,dressing change frequency,WBC level and immune function are independent influencing factors for CAI in chemotherapy treated patients.The integrated classification algorithm of random forest model can be used to predict CAI in chemotherapy treated patients,and its prediction performance is better than that of the logistic regression model.

BACKGROUND:Compared with traditional two-dimensional culture,three-dimensional microtissue culture can show greater advantages.However,more favorable cultivation methods in three-dimensional culture still need to be further explored. OBJECTIVE:To evaluate the cell behavior of microtissue and its ability to promote cartilage formation under two three-dimensional culture methods. METHODS:Cartilage-derived microcarriers were prepared by chemical decellularization and tissue crushing.DNA quantification and nuclear staining were used to verify the success of decellularization,and histological staining was used to observe the matrix retention before and after decellularization.The microcarriers were characterized by scanning electron microscopy and CCK-8 assay.Cartilage-derived microtissues were constructed by combining cartilage-derived microcarriers with human adipose mesenchymal stem cells through three-dimensional static culture and three-dimensional dynamic culture methods.The cell viability and chondrogenic ability of the two groups of microtissues were detected by scanning electron microscopy,live and dead staining,and RT-qPCR. RESULTS AND CONCLUSION:(1)Cartilage-derived microcarriers were successfully prepared.Compared with before decellularization,the DNA content significantly decreased after decellularization(P<0.001).Scanning electron microscope observation showed that the surface of the microcarrier was surrounded by collagen,maintaining the characteristics of the natural extracellular matrix of cartilage cells.CCK-8 assay indicated that microcarriers had no cytotoxicity and could promote cell proliferation.(2)Scanning electron microscopy and live and dead staining results showed that compared with the three-dimensional static group,the three-dimensional dynamic group had a more extended morphology of microtissue cells,and extensive connections between cells and cells,between cells and matrix,and between matrix.(3)The results of RT-qPCR showed that the expressions of SOX9,proteoglycan,and type Ⅱ collagen in microtissues of both groups were increased at 7 or 14 days.The relative expression levels of each gene in the three-dimensional dynamic group were significantly higher than those in the three-dimensional static group at 14 days(P<0.05).At 21 days,the three-dimensional static group had significantly higher gene expression compared with the three-diomensional dynamic group(P<0.001).(4)The results showed that compared with three-dimensional static culture microtissue,three-dimensional dynamic culture microtissue could achieve higher expression of chondrogen-related genes in a shorter time,showing better cell viability and chondrogenic ability.

The purpose of this study was to enrich the genomic information and provide a basis for further development and utilization of Polygonatum kingianum. The fresh rhizome of P. kingianum was used as the experimental material, and the full-length transcriptome was sequenced by PacBio Sequel platform. The final measured polymerase reads were 1 120 485, with a total of 77.73 GB of data. In NR database, 41 864 homologous sequence alignments were aligned to 5 species; 40 506 were annotated in the KOG database and classified into 26 categories based on their functionality; 69 060 GO annotated 32 functional groups divided into 3 categories: cellular components, molecular functions, and biological processes; 45 779 annotations were added to 145 metabolic pathways in the KEGG database. Among them, there are 127 identified transcripts related to polysaccharide synthesis in the glycolysis/gluconeogenesis metabolic pathway, 144 in the starch and sucrose metabolic pathway, 85 in the amino acid sugar and nucleotide sugar metabolic pathway, and 69 in the fructose and mannose metabolic pathway. In addition, 1 781 transcription factors were detected, distributed in 37 transcription factor families; 180 293 SSR loci were detected, among which single base repeats accounted for the most, accounting for 30.48% of all base repeats, and at least five base repeats, accounting for only 0.14% of single base repeats. The results of this study provide important data supporting for enriching the genomic information of P. kingianum and exploring its effective biosynthetic pathway.

Sustained and controlled release preparation is ideal for reducing the side effects of drugs, improving patient compliance and enhancing efficacy, among which oral sustained-release tablets are the most widely used. The in vitro release of the preparation is closely related to the in vivo absorption of the drug. However, current in vitro release experiments are labor-intensive and destructive, and the lack of big data also makes it difficult to establish good in vivo and in vitro correlations. Computer modeling, as a technical means that can transform objective principles into mathematical models, has great prospects in data prediction. This review explores the existing computer modeling methods that can be used to predict in vitro release profiles of oral sustained-release tablets, and further discusses auxiliary technologies that can improve the accuracy of the models, providing new ideas for drug development.

Objective:To explore potential predictors of refractory Mycoplasma pneumoniae pneumonia (RMPP) in early stage. Methods:The prospective multicenter study was conducted in Zhejiang, China from May 1 st, 2019 to January 31 st, 2020. A total of 1 428 patients with fever >48 hours to <120 hours were studied. Their clinical data and oral pharyngeal swab samples were collected; Mycoplasma pneumoniae DNA in pharyngeal swab specimens was detected. Patients with positive Mycoplasma pneumoniae DNA results underwent a series of tests, including chest X-ray, complete blood count, C-reactive protein, lactate dehydrogenase (LDH), and procalcitonin. According to the occurrence of RMPP, the patients were divided into two groups, RMPP group and general Mycoplasma pneumoniae pneumonia (GMPP) group. Measurement data between the 2 groups were compared using Mann-Whitney U test. Logistic regression analyses were used to examine the associations between clinical data and RMPP. Receiver operating characteristic (ROC) curves were used to analyse the power of the markers for predicting RMPP. Results:A total of 1 428 patients finished the study, with 801 boys and 627 girls, aged 4.3 (2.7, 6.3) years. Mycoplasma pneumoniae DNA was positive in 534 cases (37.4%), of whom 446 cases (83.5%) were diagnosed with Mycoplasma pneumoniae pneumonia, including 251 boys and 195 girls, aged 5.2 (3.3, 6.9) years. Macrolides-resistant variation was positive in 410 cases (91.9%). Fifty-five cases were with RMPP, 391 cases with GMPP. The peak body temperature before the first visit and LDH levels in RMPP patients were higher than that in GMPP patients (39.6 (39.1, 40.0) vs. 39.2 (38.9, 39.7) ℃, 333 (279, 392) vs. 311 (259, 359) U/L, both P<0.05). Logistic regression showed the prediction probability π=exp (-29.7+0.667×Peak body temperature (℃)+0.004×LDH (U/L))/(1+exp (-29.7+0.667×Peak body temperature (℃)+0.004 × LDH (U/L))), the cut-off value to predict RMPP was 0.12, with a consensus of probability forecast of 0.89, sensitivity of 0.89, and specificity of 0.67; and the area under ROC curve was 0.682 (95% CI 0.593-0.771, P<0.01). Conclusion:In MPP patients with fever over 48 to <120 hours, a prediction probability π of RMPP can be calculated based on the peak body temperature and LDH level before the first visit, which can facilitate early identification of RMPP.

Objective To measure the distance between the lateral compression Ⅱ(LC-Ⅱ)screw guide needle and the surrounding important structures around the anterior inferior iliac spine in pelvic fractures and to locate the needle point,so as to provide anatomical reference for clinical nail placement.Methods Totally 40 adult gross specimens of embalming were implanted with LC-Ⅱ screw guide needle under the surveillance of C-arm machine,and the specimens were dissected.The shortest distance between the insertion point and the lateral femoral cutaneous nerve,femoral nerve,femoral artery,femoral vein,anterior superior iliac spine and inguinal ligament was measured.The triangle was constructed between the insertion point,anterior superior iliac spine and inguinal ligament,and the exact location of the entry point was calculated.Results The average distance between the insertion point of the male needle and the femoral vein was(50.67±7.29)mm＞the anterior superior iliac spine(43.83±7.58)mm＞the femoral artery(38.35±6.63)mm＞the femoral nerve(31.17±1.67)mm=the inguinal ligament(28.69±6.59)mm＞the lateral femoral cutaneous nerve(7.98±3.81)mm.The mean distance between the insertion point of the female needle and the anterior superior iliac spine was(45.28±7.07)mm=femoral vein(43.72±6.89)mm＞femoral artery(33.76±6.33)mm＞femoral nerve(25.66±6.46)mm=inguinal ligament(23.22±5.00)mm＞lateral femoral cutaneous nerve(8.97±4.76)mm.The projection distance of the entry point was 31.77 mm for men and 38.41 mm for women.The Angle b was 42.81°for men and 31.71° for women.Conclusion The lateral femoral cutaneous nerve is most vulnerable to injury when LC-Ⅱ screw is inserted,and the risk of injury has nothing to do with sex.The insertion point positioning method a and b made LC-Ⅱ screw placement quickly,safely and accurately,and reduced fluoroscopy time and frequency.