BACKGROUND:Intertrochanteric fracture of femur has various fracture types and fixation methods,and the mechanical stability of each fixation system is quite different.It is of scientific clinical significance to use finite element analysis method to carry out biomechanical research on various fixation systems. OBJECTIVE:To compare and analyze the mechanical stability of various internal fixations applied to femoral intertrochanteric fracture A031-A2.1 by finite element method. METHODS:Based on the validated finite element model of femur(Intact),the model was cut and made into A031-A2.1 intertrochanteric fracture of femur.Different internal fixation systems were implanted by simulating clinical operation methods,and fixation models of proximal femoral nail antirotation,dynamic hip screw,percutaneous compression plate and proximal femoral locking plate were established respectively.All nodes under the distal femur of the four groups of models were constrained,and compression loads of 700,1 400 and 2 100 N were applied to the femoral head.Von Mises stress distribution and compression stiffness of each group of models were observed through calculation and analysis,and mechanical stability of each group was compared. RESULTS AND CONCLUSION:(1)Through calculation and analysis,after calculating the compression stiffness by comparing the deformation of each model,the compression stiffness of each model under various loads showed the trend:physiological group>proximal femoral nail antirotation group>proximal femoral locking plate group>percutaneous compression plate group>dynamic hip screw group.The compressive stiffness of the complete physiological group model was significantly higher than that of all surgical group models.(2)The stress index was observed.Due to the stress shielding effect,the stress peak value of each fixed group was higher than that of physiological group,and the maximum peak value was concentrated on each internal fixation.Proximal femoral nail antirotation group had the smallest stress peak,while dynamic hip screw group had the highest stress.The stress distribution trend showed physiological group

ObjectiveTo investigate the effect of nicotinamide adenine dinucleotide on vascular endothelial injury in hypertension and its molecular mechanism. MethodsC57BL/6J mice were randomly divided into saline group （Saline） and hypertension group （Ang Ⅱ， which were infused with Ang Ⅱ via subcutaneously implanted osmotic pumps）， and supplemented daily with nicotinamide mononucleotide （300 mg/kg）， a precursor of NAD⁺. Blood pressure， endothelial relaxation function and pulse wave velocity were measured after 4 weeks. Wound healing assay and adhesion assay were used to evaluate the function of endothelial cells in vitro. mtROS levels were detected by immunofluorescence staining. RT-PCR was used to detect the mRNA expression of mtDNA， SIRT3 and isocitrate dehydrogenase 2 （IDH2）. 8-hydroxy-2'-deoxyguanosine levels were detected by enzyme-linked immunosorbent assay. The protein expression levels of p-eNOS， eNOS， SIRT3 and IDH2 were detected by Western blot. ResultsNMN supplementation reduced blood pressure （P<0.001） and improved endothelial function and arterial stiffness （P<0.001） in hypertensive mice. In vitro， NMN improved endothelial function in AngII-stimulated endothelial cells （P<0.05） and attenuated mitochondrial oxidative stress levels （P<0.001）. Mechanistically， NMN elevated SIRT3 activity （P<0.001）， which subsequently enhanced IDH activity （P<0.001） and reduced oxidative stress levels in endothelial cells. Conversely， knockdown of IDH2 would reverse the effect of SIRT3 in improving endothelial function （P<0.001）. ConclusionNAD⁺ lowers blood pressure and enhances vascular function in hypertension by reducing the level of oxidative stress in endothelial cells through activation of the SIRT3/IDH2 signal pathway.

ObjectiveTo discuss the clinical manifestations and image features of Neuromyelitis Optica Spectrum Disorder （NMOSD）with respiratory insufficiency. We present a retrospective review about the use of double filtration plasmapheresis in the treatment of the acute attack of NMOSD in these patients. MethodsAll of our patients with central respiratory insufficiency who suffered attacks of NMOSD were retrospectively considered for inclusion. Extended Disability Status Scale（EDSS）scores were compared within six months after double membrane filtration plasma exchange. ResultsThe clinical data of the six patients included were analyzed. Magnetic Resonance Imaging confirmed that the demyelinating plaques in our patients could involve the medulla oblongata and upper spinal cord. They were managed by plasma exchange given as an initial therapy. The clinical symptoms improved significantly and the patients were successfully withdrawn from the ventilator，with EDSS scores significantly reduced （P<0.001）. ConclusionDemyelination of medulla oblongata and upper spinal cord in NMOSD may lead to acute life-threatening respiratory compromise， and early initiation of double filtration plasmapheresis can be a safe and effective treatment.

Objective Mobile artificial lumbar complex(MALC)which suitable for reconstruction after subtotal lumbar resection in goats was developed,and to test stability of the complex and postoperative lumbar segmental motor function.Methods Eighteen male boer goats aged from 1 to 2 years old(weighted from 35 to 45 kg)were selected and divided into con-trol group,fusion group and non-fusion group,with 6 goats in each group.According to preoperative CT scans and MRI exami-nations of lumbar,the goat MALC was designed and performed by 3D printed for non-fusion group.Operation was performed on three groups respectively,and only vertebral body and disc were exposed in control group.In fusion group,L4 part of vertebral body and the upper and lower complete disc tissues were removed,and the lumbar spine bone plate fixation was performed with titanium mesh bone grafting.In non-fusion group,vertebral body and disc were removed in the same way,and MALC was im-planted.AP and lateral X-rays of lumbar vertebrae in goat were taken at 6 months after surgery,in order to understand whether the plant was dislocated,displaced and fractured.Biomechanical tests were performed on the specimens by mechanical instru-ment to measure range of motion(ROM)of L2,3,L,4,L4,5intervertebral space and the overall ROM of L2-5 lumbar vertebrae.Results MALC of lumbar vertebra was designed by 3D printing,and its component artificial vertebrae and upper and lower ar-tificial end plates were manufactured.The semi-spherical structure was fabricated by precision lathe using high-crosslinked polyethylene material,and the prosthesis was assembled.Postoperative AP and lateral X-rays of lumbar vertebra at 6 months showed the implant position of implant and MALC were good without displacement and dislocation.In vitro biomechanical test of lumbar vertebrae specimens:(1)There were no statistical significance in ROM of lumbar intervertebral space flexion and extension,lateral flexion and rotation on L.4 and L4,5,between non-fusion group and control group(P＞0.05),while ROM of fu-sion group was significantly reduced compared with the other two groups(P＜0.05).There were no significant difference in ROM of L2.3 intervertebral flexion and extension,lateral flexion and rotation between non-fusion group and control group(P＞0.05),while fusion group was significantly increased compared with the other two groups(P＜0.001).(2)There was no signifi-cant difference in overall lumbar ROM of L2-5(P＞0.05).Conclusion The individual MALC could restore intervertebral height of lumbar vertebra while maintaining the stability of lumbar vertebra and re-establishing motor function of lumbar space.

Objective To investigate the clinical effect of anterior cervical discectomy and fusion(ACDF)in the treatment of cervical spondylosis of vertebral artery type(CSA).Methods The clinical data of 42 patients with CSA from January 2020 to January 2022 were retrospectively analyzed.There were 25 males and 17 females,aged from 30 to 74 years old with an average of(53.9±11.0)years old.There were 18 cases with single-segment lesions,17 cases with two-segment lesions,and 7 cases with three-segment lesions.The American Academy of Otolaryngology-Head and Neck Surgery's Hearing and Balance Committee score(CHE),the Neck Disability Index(NDI)and the cervical curvature Cobb angle were recorded before surgery and after surgery at 6 months.Results All 42 ACDF patients were followed up for 6 to 30 months with an average of(14.0±5.2)months.The operative time ranged from 95 to 220 min with an average of(160.38±36.77)min,the intraoperative blood loss ranged from 30 to 85 ml with an average of(53.60±18.98)ml.Tow patients had mild postoperative dysphagia,which improved with symptomatic treatment such as nebulized inhalation.CHE score decreased from(4.05±0.96)preoperatively to(2.40±0.70)at 6 months postoperatively(t=12.97,P＜0.05).The number of improved vertigo at 6 months postoperatively was 38,with an im-provement rate of 90.5％.NDI score was reduced from(34.43±8.04)preoperatively to(20.76±3.91)at 6 months postopera-tively(t=1 1.83,P＜0.05).The cervical curvature Cobb angle improved from(8.04±6.70)° preoperatively to(12.42±5.23)° at 6 months postoperatively(t=-15.96,P＜0.05).Conclusion The ACDF procedure has outstanding clinical efficacy in treating CSA.The operation can rapidly relieve patients'episodic vertigo symptoms by relieving bony compression and reconstructing cervical curvature.However,it is necessary to strictly grasp the indications for surgery and clarify the causes of vertigo in pa-tients,and ACDF surgery is recommended for CSA patients for whom conservative treatment is ineffective.

Objective To explore the risk factors for bile leakage after laparoscopic common bile duct exploration(LCBDE)with primary closure.Methods The clinical data of 560 patients with choledocholithiasis who underwent LCBDE with primary closure in Tianjin Hospital of Integrated Traditional Chinese and Western Medicine from September 2021 to September 2023 were retrospectively analyzed,and the patients were divided into the bile leak group and the non-bile leak group according to the occurrence of postoperative bile leakage.The risk factors affecting the occurrence of postoperative bile leakage were analyzed by multivariate analysis.Results A total of 64 cases(11.4% )experienced varying degrees of bile leakage,including 55 cases of grade A bile leakage,7 cases of grade B,and 2 cases of grade C.The thin common bile duct(OR=0.07,P<0.001),history of hypertension(OR=4.56,P<0.001),and high BMI(OR=1.17,P=0.002)were the risk factors for postoperative bile leakage in patients with choledocholithiasis.Conclusion Patients with thin common bile duct,hypertension and obesity are more likely to occur postoperative bile leakage.Patients with choledocholithiasis who have the above high-risk factors should be cautious in choosing LCBDE with primary closure.

This study was aimed at investigating the pathogenic and molecular characteristics of Klebsiella pneumoniae(KP)in fecal samples of diarrhea cases in a district of Beijing.Fecal samples from diarrhea cases in an outpatient department in a district of Beijing from 2018 to 2021 were collected,and used for isolation and culture of KP.The KP strains isolated strains were subjected to drug resistance phenotype testing and whole-genome sequencing.Multilocus sequence typing and whole-genome phyletic evolution analysis were performed on the sequencing results.The cases'epidemiological and clinical characteristics were analyzed.From 2018 to 2021,1 103 fecal samples were collected and detected.The total detection rate of KP was 10.43％(115/1 103),and the infection rate of KP mixed with other diarrhea-causing pathogens was 42.61％(49/115).The positivity rate was slightly high(12.47％,61/489)a-mong females and was highest in young adults 16-45 years of age.Small peaks were observed in January,April to May,and August to September.The gastrointestinal symptoms in cases were mainly nausea and watery stool,and the suspicious food was unknown.Ampicillin,tetracycline,and sulfafurazole were the top three antibiotics to which these 115 KP strains showed resistance,and 29 strains were resistant to multiple antibiotics.The strains were divided into 72 sequence types,among which ST23 was dominant.According to the phylogenetic tree,the strains were divided into four main branches,among which 14 ST23 strains had a very close genetic relationship with the highly virulent NTUH-K2044 reference strain.KP infection persisted in fecal samples from diarrhea cases in the district of Beijing.Women and young adults were particularly susceptible.The drug resistance of KP strains in this region was very serious,and the ST types were diverse.Moreover,the ST23 pathogenic strains were closely related to high virulence strains.

Perilla frutescens,a short-day plant,is rich in biologically active substances and nutrients.Current research on Perilla frutescens focuses on agronomic traits such as yield and fatty acid accumula-tion,with limited exploration of the flowering process and floral organ development.The molecular regu-latory mechanisms underlying these aspects remain unclear.FLOWERING LOUC T(FT)is a florigen in Arabidopsis,plays critical roles in floral transition.PfFT3 is unannotated by genome but annotated by transcriptomics data to the FT-like subfamily.Its function in controlling flowering is yet to be explored.Here subcellular localization analysis showed that PfFT3 is localized in the nucleus and cytoplasm.The plant over-expression vector pCAMBIAI1303-PfFT3 was constructed and transformed into wild-type(Col-0)and mutant fd-2,fd-3,and ft-10 plants by agrobacterium-mediated inflorescence infiltration as a means of obtaining genetically stable and pure overexpression and backfill transgenic lines in Arabidopsis,respectively.Analysis of the results showed that overexpression of PfFT3 significantly promoted early flowering in Arabidopsis and rescued the late-flowering phenotype of the mutants fd-2,fd-3,and ft-10,and that expression of the exogenous PfFT3 promoted the expression of the downstream endogenous flow-ering genes AtSOC1,AtAP1,AtFUL,and AtLFY.This study demonstrates the positive role of PfFT3 in promoting flowering,providing a foundation for further investigation of PfPEBP function and advancing the breeding of early-flowering Perilla frrutescens cultivars.

Objective:To evaluate the effect of low-dose esketamine for postoperative analgesia on the postoperative depression in patients with gastrointestinal tumors.Methods:This study was a prospective randomized controlled trial. Eighty patients, aged 18-64 yr, with a body mass index of 18-25 kg/m 2, of American Society of Anesthesiologists Physical Status classification Ⅱ or Ⅲ, scheduled for elective radical resection of the gastrointestinal tumor under general anesthesia from June to November 2023 in our hospital, were divided into 2 groups ( n=40 each) using a random number table method: esketamine group (group E) and control group (group C). Each patient received postoperative patient-controlled intravenous analgesia(PCIA). The PCIA solution in group E contained esketamine 0.5 mg/kg, dezocine 0.5 mg/kg, dexmetomidine 1.5 μg/kg and flurbiprofen ester 100 mg in 100 ml of normal saline. The PCIA solution in group C contained dezocine 0.5 mg/kg, dexmetomidine 1.5 μg/kg and flurbiprofen ester 100 mg in 100 ml of normal saline. The Hospital Anxiety and Depression Scale (HADS) was used to assess the patients′ anxiety and depression at 1 day before operation (T 0) and 2 days after operation (T 1). The Quality of Recovery-15 scale was used to evaluate the early postoperative recovery quality. Visual analog scale scores, the pressing times of patient-controlled analgesia and the number of rescue analgesia were recorded within 2 days after operation. The occurrence of drug-related adverse reactions was also recorded. Results:Seventy-eight patients were finally included, with 39 cases in group E and 39 cases in group C. Compared with group C, the postoperative HADS-depression scale score and incidence of depression were significantly decreased, the Quality of Recovery-15 scale score was increased, the visual analog scale scores were decreased ( P<0.05), and no significant changes were found in the postoperative HADS-anxiety scale score and incidence of anxiety, the pressing times of patient-controlled analgesia and the number of rescue analgesia in group E ( P>0.05). Visual hallucination was found at 1 day after operation in one patient and relieved at 2 days after operation in group E. There was no significant difference in the incidence of postoperative dizziness, nausea and vomiting between the two groups ( P>0.05). Conclusions:Postoperative analgesia with 0.5 mg/kg esketamine can alleviate postoperative depressive symptoms, enhance the efficacy of analgesia and improve the early postoperative recovery quality in patients with gastrointestinal tumors.

Objective:To evaluate the efficacy of remimazolam for induction of anesthesia in patients with colorectal cancer.Methods:This was a prospective study. Eighty-two patients scheduled for elective colon and rectal tumor surgery under general anesthesia from June to November 2023 at our hospital, aged 18-80 yr, with body mass index of 18.5-28.0 kg/m 2, of American Society of Anesthesiologists Physical Status classification Ⅰ-Ⅲ, were divided into 2 groups ( n=41 each) using a random number table method: propofol group (group P) and remimazolam group (group R). Propofol 1.5 mg/kg was intravenously injected in group R and remimazolam 0.3 mg/kg was intravenously injected in group P. When the bispectral index (BIS) value≤60, sufentanil 0.5 μg/kg and cisatracurium 0.2 mg/kg were intravenously injected in both groups. Heart rate and mean arterial pressure were recorded before induction of anesthesia (T 0), 3 min after induction (T 1), immediately after intubation (T 2), and 5 min after tracheal intubation (T 3). The occurrence of hypotension, hypertension, tachycardia and bradycardia during induction, use of vasoactive drugs, and injection pain were recorded. The time to loss of consciousness, time from the beginning of administration to BIS value ≤60, time from the beginning of administration to tracheal intubation, occurrence of BIS value > 60 immediately after intubation and rescue sedation were recorded. Results:Eighty patients were finally included, with 40 in group P and 40 in group R. Compared with group P, the heart rate and mean arterial pressure were significantly increased at T 1 and T 2, the incidence of hypotension and bradycardia was decreased, and the time from the beginning of administration to BIS value ≤60 was prolonged ( P<0.05), and no statistically significant changes were found in the other parameters in group R ( P>0.05). Conclusions:Remimazolam 0.3 mg/kg can be safely and effectively used for anesthesia induction and provides better efficacy in maintaining hemodynamic stability when compared with propofol 1.5 mg/kg in patients with colorectal cancer.