The functional realization of proteins and other biological macromolecules depends on conformational dynamics and allosteric regulation, and elucidating their molecular mechanisms is an important foundation for understanding life processes. Molecular dynamics simulations are a powerful tool for investigating conformational evolution at the atomic level. However, traditional methods are limited by simulation timescales and high free-energy barriers, making it difficult to effectively capture rare conformations and their transition pathways. As a result, the development of enhanced sampling techniques has become key to overcoming this bottleneck. As a classical enhanced sampling technique, metadynamics suffers from several shortcomings, including strong dependence on collective variables and significant errors caused by bias potential accumulation. This article reviews three major improvement strategies. The first combines stochastic resetting with metadynamics, using trajectory-resetting mechanisms to improve sampling efficiency while avoiding the difficulty of optimizing collective variables. The second, SinkMeta, employs a “sinking” bias effect to enable efficient exploration of specific regions and paths. The third, OPES-based hybrid methods, improve the stability of free-energy estimation by optimizing the target distribution or the way the bias is constructed. These methods provide new ideas for characterizing free-energy landscapes and studying conformational transitions in complex biological systems, while also promoting the continued development of enhanced sampling methodologies.

Objective To gain insights into the biological characteristics of different populations of Culex tritaeniorhynchus within and around the Yellow Sea wetland from the perspective of the occurrence of resistance, we investigated the levels of resistance to deltamethrin and kdr gene mutation in the wetland and its peripheral areas. Methods Specimens were collected from Cx. tritaeniorhynchus populations at two monitoring sites in the Rare Bird National Nature Reserve and Tiaozi Ni Wetland Scenic Area, and also from two populations in Yancheng City and the Liuhe District of Nanjing, and the resistance of these mosquitoes to deltamethrin was determined using the CDC biotest bottle method. For each concentration of deltamethrin assessed, a random subset of exposed specimens was selected for amplification of the kdr gene fragment, followed by Sanger sequencing to identify and analyze resistance-associated mutations. Results The LC50 levels of deltamethrin among mosquitoes from the four populations in Luhe, Yancheng, the Rare Bird National Nature Reserve and the Tiaozi Ni Wetland Scenic Area were 2.048 5, 7.798 2, 3.473 3, and 17.695 5 mg/mL, respectively, with corresponding concentrations of deltamethrin ranging from 0.005 to 5.000,0.050 to 50.000,0.050 to 25.000 and 0.050 to 50.000 mg/mL, respectively. Furthermore, the ranges of the KT50 values were 11.76-107.43, 67.05-216.30,29.77-107.43 and 28.40-329.51 min; the 1-h knockdown rates were 34.58%-99.15%, 9.52%-43.80%, 55.09%-73.01%, and 10.09%-68.07%; and the 24-h mortality rates were 12.15%-67.52%,9.52%-79.56%,13.17%-82.21%, and 11.01%-78.99%, respectively. With respect to kdr gene mutation, we assayed a total of 63,70,59, and 57 mosquitoes for the four populations, for which we detected L1014F mutation frequencies of 14.29%, 35.00%, 20.34%, and 31.58%, respectively, with a majority of these mutations being heterozygous for resistance. In addition, five adult mosquitoes were identified has having synonymous mutations at site 1011[i. e. , AAT(asparagine)mutation to AAC(asparagine)]. Conclusions Our findings revealed the clear resistance of Cx. tritaeniorhynchus to deltamethrin in the Yancheng region of the Yellow Sea wetland, and the resistance phenotype and kdr frequency of Cx. tritaeniorhynchus in the wetland environment were comparable to those of Cx. tritaeniorhynchus in the wetland environment, thereby indicating that the resistance of different populations of Cx. tritaeniorhynchus was homogeneous under the pressure of different insecticide selection within and around the wetland. However, the underlying mechanisms need to be further studied.

Objective To explore the health issues and influencing factors of workers in new forms of employment, represented by couriers and food delivery workers, based on the social-ecological model (SEM). Methods A total of 44 couriers and food delivery workers from Beijing City, Shanghai City, Guangzhou City, and Chongqing City were recruited as the study subjects using purposive sampling combined with snowball sampling method. An interview guide was developed based on the SEM to conduct semi-structured interviews. Thematic analysis was employed to code and analyze the interview data. Results The health influencing factors among the couriers and food delivery workers based on the SEM included three first-level themes at the micro-, meso-, and macro-levels, namely "individual factors," "occupational environmental factors," and "social environmental factors," each comprising three second-level themes. At the micro-level, individual factors such as insufficient health literacy, unhealthy lifestyles and behaviors, and sustained psychological burden jointly contributed to the health vulnerability among these couriers and food delivery workers. At the meso-level, occupational environmental factors including algorithmic management, high-load work environments, and inadequate interpersonal support, jointly construct a high-pressure and high-intensity work pattern. At the macro-level, social environmental factors such as insufficient social security caused by the de facto nature of labor relations, economic pressure resulting from unstable income in the market environment, and psychological depletion caused by occupational discrimination further exacerbate the health vulnerability among these workers. Conclusion The health issues of the couriers and food delivery workers result from the interplay of factors across micro-, meso-, and macro- levels. Therefore, a multi-level collaborative health protection system involving individuals, organizations, and society should be established to improve their health status.

Obstructive sleep apnea (OSA) is an increasingly widespread sleep-breathing disordered disease, and is an independent risk factor for many high-risk chronic diseases such as hypertension, coronary heart disease, stroke, arrhythmias and diabetes, which is potentially fatal. The key to the prevention and treatment of OSA is early diagnosis and treatment, so the assessment and diagnostic technologies of OSA have become a research hotspot. This paper reviews the research progresses of severity assessment parameters and diagnostic technologies of OSA, and discusses their future development trends. In terms of severity assessment parameters of OSA, apnea hypopnea index (AHI), as the gold standard, together with the percentage of duration of apnea hypopnea (AH%), lowest oxygen saturation (LSpO₂), heart rate variability (HRV), oxygen desaturation index (ODI) and the emerging biomarkers, constitute a multi-dimensional evaluation system. Specifically, the AHI, which measures the frequency of sleep respiratory events per hour, does not fully reflect the patients’ overall sleep quality or the extent of their daytime functional impairments. To address this limitation, the AH%, which measures the proportion of the entire sleep cycle affected by apneas and hypopneas, deepens our understanding of the impact on sleep quality. The LSpO₂ plays a critical role in highlighting the potential severe hypoxic episodes during sleep, while the HRV offers a different perspective by analyzing the fluctuations in heart rate thereby revealing the activity of the autonomic nervous system. The ODI provides a direct and objective measure of patients’ nocturnal oxygenation stability by calculating the number of desaturation events per hour, and the biomarkers offers novel insights into the diagnosis and management of OSA, and fosters the development of more precise and tailored OSA therapeutic strategies. In terms of diagnostic techniques of OSA, the standardized questionnaire and Epworth sleepiness scale (ESS) is a simple and effective method for preliminary screening of OSA, and the polysomnography (PSG) which is based on recording multiple physiological signals stands for gold standard, but it has limitations of complex operations, high costs and inconvenience. As a convenient alternative, the home sleep apnea testing (HSAT) allows patients to monitor their sleep with simplified equipment in the comfort of their own homes, and the cardiopulmonary coupling (CPC) offers a minimal version that simply analyzes the electrocardiogram (ECG) signals. As an emerging diagnostic technology of OSA, machine learning (ML) and artificial intelligence (AI) adeptly pinpoint respiratory incidents and expose delicate physiological changes, thus casting new light on the diagnostic approach to OSA. In addition, imaging examination utilizes detailed visual representations of the airway’s structure and assists in recognizing structural abnormalities that may result in obstructed airways, while sound monitoring technology records and analyzes snoring and breathing sounds to detect the condition subtly, and thus further expands our medical diagnostic toolkit. As for the future development directions, it can be predicted that interdisciplinary integrated researches, the construction of personalized diagnosis and treatment models, and the popularization of high-tech in clinical applications will become the development trends in the field of OSA evaluation and diagnosis.

In recent years, a variety of innovative fast algorithm techniques have emerged in the field of transcranial magnetic stimulation (TMS) electric field solving, which show great potential to meet the requirements of real-time clinical applications. In this review, the crucial processes of TMS electric field modeling were summarized, focusing on two prominent fast algorithm techniques, namely the basis function method and the deep neural network (DNN)-based method. The advantages and limitations of these two techniques were analyzed in detail. Commonly used software tools for electric field modeling were discussed, and a prospective discussion of future developments was offered, aiming to provide a reference for the further development of TMS electric field modeling technology.

Objective:To investigate the impact of ubiquitin-specific protease 38 (USP38) on the proliferation and migration of gastric cancer cells.Methods:Between March and September 2023, tissue samples were collected from 18 patients who underwent radical gastrectomy in the Department of General Surgery, Beijing Friendship Hospital Affiliated to Capital Medical University, and had complete clinical data. The samples included tumor tissue, adjacent tumor tissue, and normal tissue. Among the patients, there were 12 males and 6 females, aged between 34 and 71 years, with an average age of 62.5 years. The expression levels of USP38 in different tissue samples were validated using quantitative real-time reverse transcription polymerase chain reaction (qRT-PCR). The functional significance of USP38 was verified through cell experiments and human tissue samples by knocking down or exogenously overexpressing USP38. Potential molecular mechanisms of USP38 were validated through qRT-PCR, MTT, Transwell, Western blot, mass spectrometry, clone formation assays, and immunoprecipitation. Measurement data with a normal distribution are expressed as the mean±standard deviation ( ± s). Comparisons between groups were performed using a t-test or one-way analysis of variance. Measurement data with a skewed distribution were described as [ M( Q1, Q3)], and comparisons between groups were performed using non-parametric tests. Comparisons between counting data were performed using the chi-squared test or Fisher′s exact probability method, with P<0.05 indicating a statistically significant difference. Results:qRT-PCR confirmed that USP38 was highly expressed in gastric cancer tissues compared to normal and paratumor tissues. Furthermore, mass spectrometry analysis identified FASN as a potential downstream target of USP38, and immunoprecipitation experiments demonstrated a positive correlation between its expression level and USP38. USP38 was highly expressed in the SGC7901, AGS, and HGC27 gastric cancer cell lines. Knockdown of USP38 reduced FASN expression, thereby inhibiting cell proliferation and migration abilities. While the ability of cell proliferation and migration was increased significantly.Conclusions:USP38 is highly expressed in gastric cancer cells and promotes their proliferation and migration, potentially through downstream FASN-mediated fatty acid synthesis.

Objective:To investigate the perioperative safety, short-term and long-term efficacy, and surgical strategy of laparoscopic partial gastrectomy for gastrointestinal stromal tumors at the esophagogastric junction.Methods:Seventy-eight patients with mesenchymal tumors in the esophagogastric junction were retrospectively enrolled from September 2018 to August 2023 in which the upper edge of the tumor is less than 2 cm from the Z-line or has invaded the Z-line <1/2 circumference. There were 31 males (39.7%) and 47 females (60.3%), with an average age of (57.2±11.8) years and an average body mass index of (24.5±3.5) kg/m 2. All cases were divided into the wedge resection (WR) group ( n=51) and the resection by opening all of the layers of the stomach wall (RASW) group ( n=27) according to the surgical methods. Surgical outcomes, complications, recover and postoperative gastroesophageal reflux of both groups were compared. The measurement data with a normal distribution were represented by mean±standard deviation ( ± s), and values were compared using the independent sample t-test. The measurement data with a skewed distribution were represented by median (interquartile range) [ M( Q1, Q3)], and values were compared using the Mann-Whitney U test. Count data were expressed as examples (percentages) [ n(%)], and the χ2 test was used to compare countable data. A non-parametric test was used to compare the grade data. Results:The WR group had shorter operation time [(97.1±32.6) min vs (149.9±54.9) min, t=-5.33, P<0.001], less intraoperative blood loss [15(10, 20) mL vs 20(10, 50) mL, z=-2.47, P=0.014], shorter postoperative exhaust time [2(1, 3) d vs 3(2, 3) d, z=-2.49, P=0.013], shorter postoperative oral intake time [2(2, 3) d vs 4(2, 5) d, t=-3.70, P<0.001], shorter postoperative semi-liquid diet time[5(4, 6) d vs 7(5, 8) d, z=-3.57, P<0.001], and shorter postoperative hospital stay [5(4, 6) d vs 7(6, 8) d, z=-4.16, P<0.001] than the RASW group, with statistically significant differences. There was no significant difference in short-term (≤30 days) complications between the two groups (2.0% vs 3.7%, z=-0.46, P=0.648). No cases of cardia stenosis occurred in either group. In the WR group, 3 patients developed gastroesophageal reflux at 6 months postoperatively, with 2 patients relieved after taking acid-suppressing drugs and 1 patient not completely relieved. In the RASW group, 1 patient developed gastroesophageal reflux at 6 months postoperatively and was not completely relieved after taking acid-suppressing drugs. No other patients had gastroesophageal reflux. No other patients have gastroesophageal reflux. Conclusions:WR and RASW are safe and feasible for mesenchymal tumors at the esophagogastric junction in which the upper edge of the tumor is less than 2 cm from the Z-line or has invaded the Z-line <1/2 circumference, and has achieved an excellent short-term effect. The choice of surgical approach can be determined based on varions factors such as the location of the tumor, the relationship of the position between the tumor and the cardia, and whether the tumor is exophytic growth.

Prehabilitation is a novel rehabilitation strategy,mainly including sports intervention,psychological intervention,nutrition support,and other specific measures.It extends the concept of accelerated rehabilitation surgery by enhancing patients'organ function and metabolic reserve through preoperative intervention,thereby accelerating postoperative recovery.This concept has been applied to various surgical procedures,including cancer,orthopedics,thoracic surgery,and cardiac surgery.The majority of spinal surgery patients are elderly,exhibiting significant physiological decline and frailty,necessitating a multi-modal rehabilitation program that addresses body and nutrition,pain,and brain health awareness.As a subspecialty of orthopedics,there have been increasing reports on the application of prehabilitation in spinal surgery in recent years.This review summarizes the application and research progress of prehabilitation in spinal surgery,providing a reference for clinical medical staff to correctly implement prehabilitation.

Objective To explore the effects of different glucose concentrations on the synthesis and secretion of bone collagen in osteoblasts and the impact of diabetes on bone quality in mice.Methods(1)Primary osteoblasts were extracted from the skulls of neonatal mice via collagenase digestion and cultured in four groups under different glucose concentrations:normal glucose(5.5 mmol/L),moderate glucose(11.5 mmol/L),moderate-high glucose(16.5 mmol/L),and high glucose(25 mmol/L).EdU staining was performed to evaluate cell proliferation,while the Transwell assay was used to assess cell migration.Immunofluorescence and Western blotting were performed to detect and quantitatively analyze the content of type Ⅰ collagen(Col-1).Alizarin red S(ARS)staining and alkaline phosphatase(ALP)staining were applied to assess the effects of different glucose concentrations on osteogenic differentiation.(2)Six-week-old male C57BL/6 mice were randomly divided into control group and model group(5 in each group).The model group was fed a high-fat diet for 4 weeks followed by streptozotocin(STZ)injection to establish a diabetic mouse model.The osteogenic differentiation capacity of primary osteoblasts from both groups was assessed.(3)Micro-computed tomography(Micro-CT)was employed to analyze femoral bone mineral density(BMD),bone volume/tissue volume(BV/TV),trabecular number(Tb.N),and trabecular separation(Tb.Sp).Three-point bending test was conducted to evaluate mechanical parameters including maximum load,Young's modulus,fracture energy,and stiffness.RT-qPCR was employed to assess the expression of osteogenic differentiation genes(Alp,Opn,Col1a1,and Lox).Masson staining and Mallory staining were used to evaluate Col-1 content in trabecular bone.Results(1)EdU and Transwell assay results demonstrated that with the gradual increase in glucose concentration,the proliferation and migration abilities of osteoblasts were significantly decreased(P<0.001),and the protein expression levels of Col-1 and lysyl oxidase(LOX)were significantly reduced(P<0.01 or P<0.001).ARS and ALP staining revealed that calcium salt deposition and ALP activity in osteoblasts were significantly decreased with increasing glucose concentration(P<0.05 or P<0.001).(2)Compared with control group,mice in model group exhibited typical"three polies and one weight loss"symptoms(polyuria,polydipsia,polyphagia,and weight loss)of diabetes,and ARS and ALP staining showed a significant reduction in osteoblasts(P<0.001).(3)Micro-CT and three-point bending test results indicated that,compared with control group,mice in model group showed microarchitectural deterioration of bone,decreased Tb.N,increased Tb.Sp,and significantly reduced maximum load,Young's modulus,fracture energy,and stiffness(P<0.05).RT-qPCR results showed that the relative mRNA expression levels of osteogenic differentiation genes(Alp,Opn,Col1a1,and Lox)were significantly decreased in model group compared with control group(P<0.01 or P<0.001).Masson and Mallory staining indicated a significant reduction in collagen content in model group compared with control group(P<0.01).Conclusions High-glucose environment inhibits osteoblast proliferation,differentiation,and migration.Diabetic mice exhibit reduced bone quality and increased bone fragility,potentially mediated by decreased lysyl oxidase and collagen levels.

Transfer RNA-derived small RNAs(tsRNAs)are a novel class of non-coding small RNAs,which have various biological functions such as regulating gene expression,protein translation,epigenetic inheritance,cell proliferation and apoptosis,and communication.tsRNA is abnormally expressed in respiratory system cancers,lung injury,pulmonary hypertension,childhood obstructive sleep apnea-hypopnea syndrome and respiratory virus infections,affecting the occurrence and development of these diseases.However,the regulatory mechanism of tsRNAs in respiratory diseases has not been fully elucidated yet.Therefore,this review introduces the sources,classification and detection methods of tsRNA,summarizes the biological functions of tsRNA in respiratory diseases,related regulatory mechanisms,and its application prospects as biomarker in clinical diagnosis and prognosis evaluation,aiming to provide new ideas for the diagnosis and treatment of respiratory diseases,and to provide reference for in-depth research on tsRNA regulation of respiratory diseases.