ObjectiveTo explore the potential mechanism of Changji'an Formula （肠激安方） on intestinal permeability for rats with diarrhea-predominant irritable bowel syndrome （IBS-D） of liver depression and spleen deficiency syndrome by the microRNA-29b-3p （miR-29b-3p）/tumor necrosis factor receptor-associated factor 3 （TRAF3）/nuclear factor-κB （NF-κB）/myosin light chain kinase （MLCK） axis. MethodsTwenty-four 1-day-old male Sprague-Dawley （SD） suckling rats were selected， and the IBS-D rat model of liver depression and spleen deficiency syndrome was established via a three-factor method，i.e. maternal separation plus acetic acid stimulation and restraint stress， for 6 consecutive weeks. After successful modeling， the rats were randomly divided into a model group， pinaverium bromide group， low-dose and high-dose Changji'an Formula groups， with 6 rats in each group. Another 6 age-matched non-modeled SD rats were included as the control group. The low-dose and high-dose Changji'an Formula groups were given intragastric administration of Changji'an Formula solution at doses of 16.74 g/（kg·d） and 33.48 g/（kg·d）， respectively； the pinaverium bromide group received intragastric administration of pinaverium bromide tablets at 0.018 g/（kg·d）； and the control group was given distilled water at 10 ml/（kg·d） via intragastric gavage. The intervention was conducted once daily for 14 consecutive days. After the gavage treatment， the fecal water content of rats in each group was measured. Enzyme-linked immunosorbent assay （ELISA） was used to detect the serum levels of intestinal permeability indicators， including D-lactic acid （D-LA）， diamine oxidase （DAO）， and lipopolysaccharide （LPS）. Quantitative real-time polymerase chain reaction （qRT-PCR） was conducted to determine the mRNA expression levels of miR-29b-3p， TRAF3， tumor necrosis factor-α （TNF-α）， p65， p50， and MLCK in colonic tissues. Western Blot analysis was employed to detect the protein expression levels of TRAF3， TNF-α， p65， phosphorylated p65 （p-p65）， MLCK， myosin light chain （MLC）， phosphorylated MLC （p-MLC）， and tight junction proteins including junctional adhesion molecule-A （JAM-A）， Occludin， and Claudin-1 in colonic tissues. ResultsCompared with the control group， the model group exhibited significantly increased fecal water content and serum levels of D-LA， DAO， and LPS， along with decreased protein expression levels of JAM-A， Occludin， and Claudin-1 in colonic tissues （P＜0.05 or P＜0.01）. Additionally， in the model group， the mRNA expression levels of miR-29b-3p， TNF-α， p65， p50， and MLCK in colonic tissues were up-regulated， while the mRNA and protein expression levels of TRAF3 were down-regulated； the protein levels of TNF-α and MLCK， as well as the ratios of p-p65/p65 and p-MLC/MLC， significantly elevated （P＜0.01）. Compared with the model group， all treatment groups showed reduced fecal water content and serum levels of D-LA， DAO， and LPS， along with down-regulated mRNA expression levels of miR-29b-3p， TNF-α， p65， p50， and MLCK， and up-regulated TRAF3 mRNA expression in colonic tissues. Moreover， the pinaverium bromide group and high-dose Changji'an Formula group presented increased protein levels of Occludin， Claudin-1， and TRAF3， as well as decreased protein levels of TNF-α and MLCK， and reduced ratios of p-p65/p65 and p-MLC/MLC in colonic tissues （P＜0.05 or P＜0.01）. Compared with the low-dose Changji'an Formula group， the high-dose group had lower fecal water content and serum levels of DAO and LPS （P＜0.01）. In comparison with the pinaverium bromide group， the high-dose Changji'an Formula group showed a significant decrease in serum DAO level （P＜0.01）. ConclusionsChangji'an Formula can reduce intestinal permeability and restore intestinal barrier function in IBS-D rats of liver depression and spleen deficiency syndrome by regulating the miR-29b-3p/TRAF3/NF-κB/MLCK axis.

Objective To analyze the effect of releasing the lower pulmonary ligament on right residual lung expansion after right upper lobe resection under different body mass index (BMI) levels. Methods The clinical data of patients who underwent thoracoscopic right upper lobe resection in the First Affiliated Hospital with Nanjing Medical University from 2021 to 2022 were retrospectively analyzed. Patients were divided into a group A (17 kg/m2＜BMI≤23 kg/m2), a group B (23 kg/m2＜BMI≤29 kg/m2) and a group C (BMI＞29 kg/m2) according to BMI. The presence of residual cavity was judged by chest X-ray at 7-10 days after operation, the degree of compensation change of the right main bronchus angle was measured, and the changes in lung volume were determined by CT three-dimensional reconstruction. Results A total of 157 patients who underwent thoracoscopic right upper lobe resection were included, including 71 males and 86 females, with an average age of (59.7±11.2) years. There were 50 patients in the group A, 75 patients in the group B, and 32 patients in the group C. In the group A, compared with those without releasing the lower pulmonary ligament, patients with releasing had a lower incidence of postoperative residual cavity (P=0.016), greater changes in bronchus angle (P<0.001), and smaller changes in lung volume (P<0.001). In the group B and C, there was no significant effect of releasing the lower pulmonary ligament on postoperative residual cavity, bronchus angle, and lung volume changes (P>0.05). Conclusion For patients with thin and long body shape and low BMI, releasing the lower pulmonary ligament is helpful to promote the expansion of the residual lung after right upper lobe resection and reduce the occurrence of postoperative residual cavity in patients.

Objective Magnetoreception, the remarkable ability of diverse animals to sense and utilize the geomagnetic field for orientation and navigation, remains a molecularly unresolved mystery in sensory biology. The putative magnetoreceptor (MagR, previously known as IscA1) is a highly conserved iron-sulfur protein implicated in both magnetoreception and iron metabolism; however, the functional diversity among its cross-species homologs remains poorly understood. Cellular morphology is a key genetically determined trait that can be altered through genetic or environmental modifications—a process known as cell morphology engineering. Constructing engineered cells with specific morphological features and magnetic sensitivity to achieve remote, non-invasive magnetic modulation represents a crucial goal in this field with significant application potential. Therefore, this study aims to systematically investigate the effects of MagR heterologous expression on bacterial morphology and magnetic sensing capabilities, screen for MagR-based magnetically sensitive morphology engineering pathways, and reveal the underlying molecular mechanisms. Methods We systematically screened 28 MagR homologous genes from diverse prokaryotic and animal taxa to evaluate their expression and corresponding phenotypic effects in Escherichia coli (E. coli). To compare the differential magnetic responses among bacteria expressing various recombinant MagR proteins, we utilized high-throughput automated bright-field microscopic imaging and scanning electron microscopy (SEM). Furthermore, comprehensive biochemical and biophysical characterizations of iron and iron-sulfur cluster binding were performed using Ferrozine colorimetric assays, electron paramagnetic resonance (EPR) spectroscopy, ultraviolet-visible (UV-Vis) absorption, and circular dichroism (CD) spectroscopy. Additionally, 100 mT static magnetic field (SMF) exposure experiments were conducted to assess magnetically tunable phenotypes, while the intrinsic magnetic properties of purified MagR proteins were directly measured using a superconducting quantum interference device (SQUID) magnetometer. Results Our results demonstrated that the heterologous expression of MagR homologs induced varying degrees of bacterial filamentation. From this comprehensive screen, two distinct morphological patterns were identified: hydra (Hydra vulgaris) MagR (hyMagR) promoted uniform cell elongation and filamentation, exhibiting robust magnetic sensitivity manifested as significantly enhanced filamentation under the 100 mT SMF. In contrast, pigeon (Columba livia) MagR (clMagR) induced only low-frequency, extreme filamentation (sporadically exceeding 80 μm) with a relatively weaker magnetic morphological response. Mechanistically, our data unambiguously proved that these phenotypic differences are primarily driven by distinct iron redox preferences rather than total cellular iron accumulation. Specifically, hyMagR preferentially binds ferrous iron (Fe²⁺), whereas clMagR favors ferric iron (Fe³⁺) and forms more stable iron-sulfur clusters. Intriguingly, although SQUID magnetometry showed that purified clMagR exhibited approximately five-fold higher mass magnetic susceptibility than hyMagR, its cellular magnetic response was weaker. We hypothesize that the Fe²⁺-preferred intracellular environment associated with hyMagR overexpression primes the cell for enhanced generation of reactive oxygen species (ROS) via the Fenton reaction. Exposure to an SMF synergizes with this primed redox state, triggering the bacterial SOS response and upregulating cell division inhibitors to efficiently induce uniform filamentation. Conclusion Our findings identify the Fe²⁺/Fe³⁺ redox state as a critical determinant of MagR-mediated morphological remodeling and magnetic responsiveness. This discovery suggests a potential strategy for engineering magnetically responsive cellular systems for synthetic biology applications, and provides a plausible framework, which potentially combines intrinsic protein magnetism with redox-state modulation, for further investigating the evolutionary mechanisms of MagR-mediated magnetoreception.

Objective Magnetoreception, the remarkable ability of diverse animals to sense and utilize the geomagnetic field for orientation and navigation, remains a molecularly unresolved mystery in sensory biology. The putative magnetoreceptor (MagR, previously known as IscA1) is a highly conserved iron-sulfur protein implicated in both magnetoreception and iron metabolism; however, the functional diversity among its cross-species homologs remains poorly understood. Cellular morphology is a key genetically determined trait that can be altered through genetic or environmental modifications—a process known as cell morphology engineering. Constructing engineered cells with specific morphological features and magnetic sensitivity to achieve remote, non-invasive magnetic modulation represents a crucial goal in this field with significant application potential. Therefore, this study aims to systematically investigate the effects of MagR heterologous expression on bacterial morphology and magnetic sensing capabilities, screen for MagR-based magnetically sensitive morphology engineering pathways, and reveal the underlying molecular mechanisms. Methods We systematically screened 28 MagR homologous genes from diverse prokaryotic and animal taxa to evaluate their expression and corresponding phenotypic effects in Escherichia coli (E. coli). To compare the differential magnetic responses among bacteria expressing various recombinant MagR proteins, we utilized high-throughput automated bright-field microscopic imaging and scanning electron microscopy (SEM). Furthermore, comprehensive biochemical and biophysical characterizations of iron and iron-sulfur cluster binding were performed using Ferrozine colorimetric assays, electron paramagnetic resonance (EPR) spectroscopy, ultraviolet-visible (UV-Vis) absorption, and circular dichroism (CD) spectroscopy. Additionally, 100 mT static magnetic field (SMF) exposure experiments were conducted to assess magnetically tunable phenotypes, while the intrinsic magnetic properties of purified MagR proteins were directly measured using a superconducting quantum interference device (SQUID) magnetometer. Results Our results demonstrated that the heterologous expression of MagR homologs induced varying degrees of bacterial filamentation. From this comprehensive screen, two distinct morphological patterns were identified: hydra (Hydra vulgaris) MagR (hyMagR) promoted uniform cell elongation and filamentation, exhibiting robust magnetic sensitivity manifested as significantly enhanced filamentation under the 100 mT SMF. In contrast, pigeon (Columba livia) MagR (clMagR) induced only low-frequency, extreme filamentation (sporadically exceeding 80 μm) with a relatively weaker magnetic morphological response. Mechanistically, our data unambiguously proved that these phenotypic differences are primarily driven by distinct iron redox preferences rather than total cellular iron accumulation. Specifically, hyMagR preferentially binds ferrous iron (Fe²⁺), whereas clMagR favors ferric iron (Fe³⁺) and forms more stable iron-sulfur clusters. Intriguingly, although SQUID magnetometry showed that purified clMagR exhibited approximately five-fold higher mass magnetic susceptibility than hyMagR, its cellular magnetic response was weaker. We hypothesize that the Fe²⁺-preferred intracellular environment associated with hyMagR overexpression primes the cell for enhanced generation of reactive oxygen species (ROS) via the Fenton reaction. Exposure to an SMF synergizes with this primed redox state, triggering the bacterial SOS response and upregulating cell division inhibitors to efficiently induce uniform filamentation. Conclusion Our findings identify the Fe²⁺/Fe³⁺ redox state as a critical determinant of MagR-mediated morphological remodeling and magnetic responsiveness. This discovery suggests a potential strategy for engineering magnetically responsive cellular systems for synthetic biology applications, and provides a plausible framework, which potentially combines intrinsic protein magnetism with redox-state modulation, for further investigating the evolutionary mechanisms of MagR-mediated magnetoreception.

Nitrogen oxides(NOx=NO+NO2)are important precursors of ozone(O3),and NOx and its oxides together constitute reactive nitrogen oxides(NOy)in the atmosphere.A comprehensive understanding of the total NOy level in the atmosphere is of great significance for a deeper understanding of the atmospheric nitrogen cycle and oxidation,as well as for formulating strategies for air pollution prevention and control.In this work,a thermal decomposition-broadband cavity enhanced absorption spectroscopy(TD-BBCEAS)technique for online measurement of total NOy in the atmosphere was developed.With this method,the NOy was efficiently converted into NO2,and the total NOy concentration in the atmosphere was indirectly obtained by measuring NO2.Focusing on the key factors affecting the measurement of total NOy,the influence of NO titration efficiency and other NOy component TD efficiency on measurement accuracy was emphasized.By changing the oxygen(O2)flow rate through the mercury lamp to alter the O3 concentration for titrating NO,the conversion efficiency of NO was evaluated.At O2 flow rate of 6 mL/min,the conversion efficiency of NO was greater than 99%.TD efficiency testing and analysis on NO2,peroxyacetyl nitrate(PAN),nitric acid(HNO3),and nitrous acid(HONO),which account for a large proportion of atmospheric NOy components,was carried out using 680℃as the optimal TD temperature for efficient conversion of NOy.With NO and HONO sample gases as typical verification gases,the conversion efficiency of NOy and the accuracy of NOy measurement by TD-BBCEAS system were verified by switching the on and off modes of mercury lamp and TD device.At integration time of 60 s,the detection limit of the system for NOy was 2.83×1010 molecules/cm3(60 s,2σ).A comparative measurement of actual atmospheric NOy was conducted between the TD-BBCEAS system and the NOy analyzer.The observation results showed a correlation coefficient(R2)of 0.98 and a slope of 0.93,further verifying the feasibility and accuracy of applying the TD-BBCEAS system to measurement of total NOy.

Forensic medicine has been designated as a first-level discipline,presenting new opportunities and challenges for the development of forensic medicine.Since the 1980s,the establishment of foren-sic medicine discipline and the cultivation of high-level forensic talents have become hot topics in the development of forensic medicine in China.Since the 13th Five-Year Plan,the forensic team of Shanxi Medical University has been aiming at the forefront,proposing the development goals of"Five First-class"and the discipline development path"Six Major Achievements".It has selected benchmark disci-plines,identified gaps in disciplinary development,unified thoughts,formulated completion timelines,concentrated superior resources,assigned tasks to individuals,and created an"Organized Fill-in-the-Blank Format"forensic medicine discipline construction model with the characteristics of the new era.The construction model of forensic medicine has achieved good results in the goals,discipline frame-work,scientific research,talent cultivation,discipline team and platform construction,forming a rela-tively complete discipline construction and management system,and accumulating valuable experience for the construction of first-level discipline and high-level talent cultivation of forensic medicine.

Objective To explore the correlation of body mass index,urinary protein and tumor necrosis factor-like weak inducer of apoptosis(sTWEAK)during pregnancy with the severity of preeclampsia and pregnancy outcome.Methods A total of 63 patients with preeclampsia who were examined in Xingtai People's Hospital from April 2022 to April 2023 were enrolled in the study,33 patients with mild preeclampsia were included in the mild group and 30 patients with severe preeclampsia were included in the severe group.Physi-cal characteristics,urinary protein and sTWEAK levels between the groups were recorded,and the patients were followed up to explore the correlation with pregnancy outcome.Results The systolic and diastolic blood pressure of patients in the mild group were lower than those in the severe group,and the plasma albumin was higher than that in the severe group(P＜0.05).There was no statistically significant difference in pre preg-nancy weight and pre pregnancy body mass index between the mild and severe groups of patients(P＞0.05).The delivery weight and weight gain during pregnancy in the mild group were lower than those in the severe group(P＜0.05).The 24-hour urinary protein quantification in the mild group was lower than that in the se-vere group,and the sTWEAK expression level was higher than that in the severe group(P＜0.05).The pre pregnancy weight,pre pregnancy body mass index,delivery weight,and weight gain during pregnancy in the good pregnancy outcome group were all lower than those in the adverse pregnancy outcome group(P＜0.05).The 24-hour urinary protein quantification in the good pregnancy outcome group was lower than that in the adverse pregnancy outcome group,and the sTWEAK expression level was higher than that in the adverse pregnancy outcome group(P＜0.05).Receiver operating characteristic(ROC)curve analysis revealed that the area under the curve(AUC)of pre pregnancy body mass index,pre pregnancy weight,delivery weight,gestational weight gain,24-hour urinary protein quantification,and sTWEAK expression levels for predicting adverse pregnancy outcomes in patients were 0.906,0.690,0.919,0.664,0.908,and 0.793,respectively.The AUC for predicting adverse pregnancy outcomes in patients by combining pre pregnancy body mass index,de-livery weight,24-hour urinary protein quantification,and sTWEAK expression level was 0.932.Conclusion Body mass index,urinary protein and sTWEAK levels during pregnancy are closely associated with the severity of pre-eclampsia and pregnancy outcomes,and these indicators may help identify high-risk pregnant women early and take appropriate interventions to improve pregnancy outcomes.

Objective To explore the anesthesia management experience in the interventional treatment of pediatric congenital heart diseases (CHD) percutaneously guided by transthoracic echocardiography (TTE) on a mobile operating platform. Methods From March to July 2023, a total of 13 patients from remote areas underwent interventional treatment for CHD on the mobile operating platform of Fuwai Yunnan Cardiovascular Hospital. Patients who received non-tracheal intubation general anesthesia were retrospectively included. Results Eight children who had difficulty cooperating with the surgery (due to young age, emotional tension, crying) received monitored anesthesia care with local anesthesia supplemented by sedative and analgesic drugs while maintaining spontaneous breathing under the monitoring and management of an anesthesiologist (i.e., non-tracheal intubation general anesthesia). Among them, there were 5 males and 3 females, with an age of (6.95±3.29) years and a body weight of (19.50±6.04) kg. Through transthoracic echocardiography, they were diagnosed with atrial septal defect (6 patients), residual shunt after patent ductus arteriosus ligation (1 patient), and severe pulmonary valve stenosis (1 patient). The surgery proceeded smoothly, with satisfactory anesthesia and surgical effects, complete analgesia, and satisfactory postoperative recovery. There was 1 patient of body movement and 1 patient of respiratory depression during the operation, and both patients completed the surgery successfully after treatment. All children had no serious surgery- and anesthesia-related complications. The anesthesia time was 40.5 (34.5, 47.5) min, the surgery time was 39.0 (33.0, 45.5) min, and the recovery time was 43.0 (28.0, 52.5) min Conclusion Interventional surgery for CHD guided by TTE at a mobile platform is a minimally invasive approach without radiation damage. Non-tracheal intubation general anesthesia with spontaneous breathing can be safely and effectively implemented in children who cannot cooperate.

OBJECTIVE:The optimal non-surgical therapy for chronic ankle instability remains unclear due to the continuous introduction of novel treatment methods despite the availability of several non-surgical options for improving foot and ankle function and dynamic balance in chronic ankle instability patients.This study aims to investigate the most effective non-surgical therapy options to improve foot and ankle function and dynamic balance for patients with chronic ankle instability using a network meta-analysis. METHODS:Using"CAI,exercise,and randomized controlled trial"as search terms,a literature search of PubMed,Embase,Cochrane Library,and Web of Science databases was conducted through a computer network to collect information from the databases from their inception to March 2024 on non-surgical therapies for the treatment of chronic ankle instability randomized controlled trials on foot and ankle function or dynamic balance in patients.EndNote software was utilized for literature management.RevMan 5.4 software and Cochrane Risk of Bias Assessment Tool were used to evaluate the risk of bias of the included literature.Paired meta-analysis and network meta-analysis of the outcomes such as the Foot and Ankle Ability Measure in daily living subscale score,Foot and Ankle Ability Measure in sports activities subscale score,Star Excursion Balance Test-Anterior score,Star Excursion Balance Test-Posteromedial score,Star Excursion Balance Test-Posterolateral score and Cumberland ankle instability tool score were performed using the network commands of Stata 14.0 software.The strength of evidence rating of the outcome metrics was evaluated according to the GRADE Level of Evidence and Strength of Recommendation Grading Criteria. RESULTS:Of the 22 randomized controlled trials that met the inclusion criteria,1 study was rated as low risk,8 studies were rated as medium risk,and 13 studies were rated as high risk,enrolling a total of 952 patients and 25 treatments.(1)Network meta-analysis showed that compared with the control group,Isokinetic Strength Training,Balance Training,Balance+Stroboscopic Glasses Training,Strength Training,Joint Mobilizations Training,CrossFit Training,CrossFit Training+Self-Mobilization,Wobble Board Training,National Academy of Sport Medicine corrective exercise program,Trigger Point Dry Needling,and Neuromuscular Training had different significant enhancement effects on improving foot and ankle function and dynamic balance in patients with chronic ankle instability(P<0.05).(2)Cumulative probability ranking results showed that the three treatments with the highest ranked Cumberland ankle instability tool score were Joint Mobilizations Training(88.6%)>Visual Feedback Balance Training(83.1%)>CrossFit Training+Self-Mobilization(74.8%);the three treatments with the highest ranked Star Excursion Balance Test-Anterior score were Joint Mobilizations Training(88.4%)>Isokinetic Strength Training(86.9%)>National Academy of Sport Medicine corrective exercise program(65.0%);the three treatments with the highest ranked Star Excursion Balance Test-Posteromedial score were Balance+Stroboscopic Glasses Training(87.4%)>Neuromuscular Training(74.6%)>Strength Training(68.9%);the three treatments with the highest ranked Star Excursion Balance Test-Posterolateral score were CrossFit Training+Self-Mobilization(74.6%)>Balance+Stroboscopic Glasses Training(70.0%)>Neuromuscular Training(63.7%);the three treatments with the highest ranked Foot and Ankle Ability Measure in daily living subscale score were National Academy of Sport Medicine corrective exercise program(91.9%)>Balance+Stroboscopic Glasses Training(85.6%)>Wobble Board Training(82.2%);the three treatments with the highest ranked Foot and Ankle Ability Measure in sports activities subscale score were Balance+Stroboscopic Glasses Training(93.5%)>Balance Training(86.7%)>National Academy of Sport Medicine corrective exercise program(86.4%). CONCLUSION:Non-surgical therapies can significantly improve foot and ankle function and dynamic balance in patients with chronic ankle instability.National Academy of Sport Medicine corrective exercise program had the best efficacy in improving foot and ankle daily activity function in chronic ankle instability patients;Balance+Stroboscopic Glasses Training had the best efficacy in improving foot and ankle sports function and posterior medial dynamic balance;Joint Mobilizations Training had the best efficacy in improving anterolateral dynamic balance and ankle instability condition;and CrossFit Training+Self-Mobilization had the best efficacy in improving posterior lateral dynamic balance.The strength of evidence for each outcome was low,influenced by the risk of methodological bias and risk of publication bias of the included studies.Therefore,the above conclusions need to be validated by more high-quality pilot studies.

Objective To observe the effects of complex small molecule peptides on postoperative nutritional status and immune function of elderly patients with lower limb fractures.Methods A total of 160 elderly patients with unilateral hip fractures or unilateral femoral neck fractures who were hospitalized in Wuxi People's Hospital from April 2020 to September 2023 were selected and randomly assigned to experimental group or control group,with 80 cases in each group.The nutritional status of the patients was evaluated by using the mini nutritional assessment short-form(MNA-SF).From 3 days before surgery to 7 days after surgery,the patients in both groups were given standard nutritional intervention,including dietary guidance and volume-based diets.Additionally,the experimental group was orally administered complex small molecule peptides at a dose of 20 g/d.The blood biochemical and immunological indicators,as well as body composition were tested before and after nutritional intervention.Results All the 160 elderly patients with lower extremity fractures successfully completed the study.The liver and kidney functions of the patients were normal.Serum levels of prealbumin,albumin,total protein and hemoglobin(Hb)were decreased after the operation,and the serum protein level in the experimental group after the operation was significantly higher than that in the control group.Lymphocytes,immunoglobulin G,IgA and IgM were increased after the operation,and these parameters in the experimental group were higher than those in the control group(P<0.05).There was no significant difference in the C-reactive protein between the two groups before the operation.However,after the operation,CRP was increased in both groups,and CRP in the experimental group was lower than that in the control group(P<0.05).The incidence of postoperative malnutrition in the experimental group was significantly lower than that in the control group(17.5%vs.33.75%,χ2=5.542,P=0.019).The waist circumference,skeletal muscle mass index,mineral content,upper arm circumference and skeletal muscle were decreased after surgery,and these indicators in the experimental group were better than those in the control group(P<0.05).The postoperative hospital stay and wound healing time in the experimental group were significantly shorter than those in the control group(P<0.05).The incidence of postoperative infection in the experimental group was significantly lower than that in the control group(8.75%vs.20%,χ2=4.113,P=0.043).Conclusion Complex small molecule peptide can significantly increase the serum protein level of elderly patients with lower extremity fractures,improve their nutritional status and immune function,reduce inflammatory response and postoperative infection,promote wound healing,shorten hospital stay,improve prognosis and clinical outcomes,and is worthy of clinical application.