Objective To identify the risk factors of prolonged mechanical ventilation (PMV) after lung transplantation. Methods Clinical data of 90 recipients undergoing lung transplantation were retrospectively analyzed. According to the duration of invasive mechanical ventilation after operation, all recipients were divided into the PMV group (ventilation duration > 48 h, n=30) and control group (ventilation duration≤48 h, n=60). Perioperative parameters were compared between two groups, including preoperative parameters [serum creatinine, estimated glomerular filtration rate (eGFR)], intraoperative parameters (cold ischemia time of donor lung, blood loss), and postoperative parameters [the first red blood cell, white blood cell, platelet count, hemoglobin, C-reactive protein, serum creatinine, total bilirubin, alanine aminotransferase (ALT), oxygenation index, eGFR and the mean arterial pressure in intensive care unit (ICU)]. The risk factors of PMV after lung transplantation were assessed by multivariate logistic regression analysis. Results Preoperative serum creatinine level in the PMV group was 62 (53, 67) μmol/L, significantly higher than 57 (47, 62) μmol/L in the control group. Preoperative eGFR in the PMV group was 97 (93, 107) mL/min, significantly lower than 106 (102, 116) mL/min in the control group. The first postoperative oxygenation index in the PMV group was 196 (157, 286) mmHg, significantly lower than 250 (199, 354) mmHg in the control group (all P < 0.05). Multivariate analysis showed that the first increase of postoperative total bilirubin, the first decrease of postoperative oxygenation index and preoperative eGFR decrease were the independent risk factors for PMV following lung transplantation. Conclusions The first increase of postoperative total bilirubin, the first decrease of postoperative oxygenation index and preoperative eGFR decrease are the independent risk factors for PMV after lung transplantation.

Objective:To observe the impacts of different postures on the hemodynamics of lower extremity vein.Methods:In this single center non-randomized controlled study in 15 healthy female volunteers, the hemodynamic changes in the common femoral vein were detected by color Doppler ultrasound at 10 different postures: supine position, slope positions with bed end elevated at 15°, 30° and 45°, trapezoidal positions with bed end elevated at 15°, 30° and 45°, and positions with bed head elevated at 30°, 45° and 60°.Results:Different postures resulted in significant differences in the velocity of blood flow in the common femoral vein ( P<0.05), with slope position at 45°> slope position at 30°> slope position at 15° = trapezoidal position at 30°> trapezoidal position at 15° = trapezoidal position at 45°> supine position> position with bed head elevated at 30°> position with bed head elevated at 45° = position with bed head elevated at 60°. Conclusions:In the postures observed in this study, the slope position with bed end elevated at 45° can promote the most effectively the blood reflux in the lower extremity vein, the trapezoidal positions with bed end elevated may not facilitate the distal blood reflux in the lower extremity vein, and positions with bed head elevated may hinder the blood reflux in the lower extremity vein.

Objective:To investigate the epidemiological characteristics of lower extremity deep vein thrombosis (DVT) in patients with femoral fracture.Methods:Retrospectively analyzed were the data of 2,571 patients with femoral fracture who had been treated at the Third Hospital of Hebei Medical University from January 2019 to December 2019. There were 1,079 males and 1,492 females, aged from 14 to 96 years (average, 67.1 years). There were 1,158 femoral neck fractures, 951 femoral intertrochanteric fractures, 309 femoral shaft fractures, and 153 femoral condylar fractures. 2,414 patients were treated surgically while 157 patients non-surgically. Color Doppler ultrasonography of both lower extremities was performed to determine the occurrence of DVT before operation and every week after operation for patients undergoing surgical treatment, and within 48 hours after admission and every week during hospitalization for those undergoing non-surgical treatment. The incidence and location of DVT were recorded for different femoral fractures.Results:The incidence of DVT in this cohort was 35.5%(913/2,517), that of proximal DVT 5.3%(135/2,571), and that of distal DVT 30.3% (778/2,571). In patients with femoral neck fracture, femoral intertrochanteric fracture, femoral shaft fracture and femoral condylar fracture, the incidence of DVT was respectively 28.8% (334/1,158), 44.7% (425/951), 30.7% (95/309) and 38.6% (59/153), the incidence of proximal DVT was respectively 2.7% (31/1,158), 5.6%(53/951), 9.7% (30/309) and 13.7% (21/153), and the incidence of distal DVT was respectively 26.2% (303/1,158), 39.1% (372/951), 21.0% (65/309) and 24.8%(38/153). The incidence of DVT in the femoral vein and above, popliteal vein, tibiofibular vein and intermuscular vein in this cohort was respectively 2.3%(60/2,571), 2.9%(75/2,571), 6.4%(165/2,571) and 23.8%(613/2,571).Conclusions:The incidence of DVT may be high in patients with femoral fracture, and the proximal DVT with a high risk of pulmonary embolism may occur more in patients with femoral condylar fracture.

Objective: To investigate the effect of nimodipine combined with cerebrospinal fluid replacement on hemoglobin concentration, Toll-like receptor 4 (TLR4) expression level and cerebral vasospasm (CVS) in patients with CVS after aneurysmal subarachnoid hemorrhage (aSAH). Methods: One hundred and twenty patients with CVS after aSAH admitted to the Department of Neurosurgery, the Sixth Medical Center of PLA General Hospital from May 2013 to May 2015 were selected. They were randomly divided into control group and observation group (n=60 in each group). The control group received conventional treatment and nimodipine infusion after embolization of the aneurysms, and the observation group underwent cerebrospinal fluid replacement by lumbar puncture on this basis. The clinical efficacy, Glasgow Coma Scale (GCS) scores, hemoglobin concentration and TLR4 expression levels before and after treatment, and adverse reactions were compared between the two groups. Results: One month after treatment, the improvement rate of vasospasm in the observation group was significantly higher than that in the control group (86.7% vs. 60.0%; χ²=9.590, P=0.002). Three months after the treatment, the good rate of clinical outcome (the modified Rankin Scale score 0-2) was significantly higher than that of the control group (88.3% vs. 58.3%; χ² =13.807, P<0.001). Before treatment, there were no significant differences in hemoglobin concentration and TLR4 expression levels between the two groups; after treatment, the hemoglobin concentration and TLR4 expression levels of both groups were significantly reduced (P<0.05). Compared with the control group, the hemoglobin concentration (119.9±19.8 g/L vs. 137.6±17.8 g/L; t=3.270, P=0.001) and TLR4 expression level (2.5±1.2 vs. 4.5±1.5; t=8.060, P<0.001) in the observation group decreased more significantly. Multivariate logistic regression analysis showed that hypertension (odds ratio [OR] 5.19, 95% confidence interval [CI] 2.31-6.71), hyperlipidemia (OR 2.70, 95% CI 1.93-4.86), previous history of stroke or transient ischemic attack (OR 6.29, 95% CI 3.23-7.32), smoking (OR 4.80, 95% CI 2.18-6.19), and the TLR4 expression level before treatment (OR 3.28, 95% CI 2.87-6.93) were independently correlated with the lack of improvement in CVS, and cerebrospinal fluid replacement was independently correlated with CVS improvement (OR 0.40, 95% CI 0.14-0.89). There was no significant difference in the incidence of adverse reactions such as blood pressure drop, obstructive hydrocephalus and gastrointestinal hemorrhage between the observation group and the control group, but the incidence of delayed CVS (13.3% vs. 36.7%; χ²=7.510, P=0.006) and secondary cerebral infarction (8.3% vs. 31.7%; χ²=8.800, P=0.003) in the observation group were significantly lower than those of the observation group. Conclusion Nimodipine infusion combined with cerebrospinal fluid replacement by lumbar puncture affected the hemoglobin concentration and TLR4 expression levels, improved the CVS improvement rate, and significantly improved the clinical outcome in patients with CVS after aSAH.

Objective:To investigate the predictive value of Charlson comorbidity index (CCI) in the operative prognosis of colorectal cancer (CRC).Methods:The retrospective cohort study was conducted. The clinicopathological data of 1 337 CRC patients who underwent surgery in the First Affiliated Hospital of Xi'an Jiaotong University from January 2013 to February 2019 were collected. There were 774 males and 563 females, aged 62(range, 22?80)years. All patients were evaluated by CCI. Observation indicators: (1) clinicopathological characteristics of CRC patients undergoing operation; (2) follow-up and survival; (3) prognostic factors analysis of CRC patients undergoing operation; (4) establishment and evaluation of a nomogram prediction model based on CCI. Follow-up was conducted using the telephone interview or outpatient examination to detect the survival of patients up to March 2020. Measurement data with normal distribution were represented as Mean± SD, and comparison between groups was analyzed using the t test. Measurement data with skewed distribution were described as M(range) or M( Q1, Q3), and comparison between groups was analyzed using the Mann-Whitney U test. Count data were described as absolute numbers or percentages, and comparison between groups was analyzed using the chi-square test. Non-para-meter rank sum test was used for comparison of ordinal data. The Kaplan‐Meier method was used to calculate survival rates and draw survival curves, and Log-Rank test was used for survival analysis. Univariate and multivariate analyses were performed using the COX proportional hazard regression model. The independent risk factors were included into R4.0.4 software to construct a nomogram prediction model. The receiver operating characteristic (ROC) curve was drawn, and the area under curve (AUC) was used to evaluate discrimination of the nomogram prediction model. The C-index and calibration chart were used to evaluate consistency of the nomogram prediction model. Results:(1) Clinicopathological characteristics of CRC patients undergoing operation. Of the 1 337 patients, there were 1 041 cases with CCI ≤3 and 296 cases with CCI ≥4. Age, cases with non-smoking history, smoking cessation or smoking history, cases without or with R 0 resection, cases with low, moderate, well differentiated tumor, cases in stage Ⅰ?Ⅱ or Ⅲ?Ⅳ of clinical TNM staging, preoperative carcinoembryonic antigen (CEA) were 61(53,68)years, 717, 43, 281, 12, 1 029, 123, 859, 59, 666, 375, 3.22(1.84,7.75)μg/L for the 1 041 patients with CCI ≤3, versus 70(61,75)years, 217, 19, 60, 43, 253, 48, 237, 11, 102, 194, 5.55(2.43,17.64)μg/L for the 296 patients with CCI ≥4, showing significant differences in the above indicators between them ( Z=?10.50, χ2=7.34, 104.51, Z=?2.31, χ2=82.14, Z=?5.78, P<0.05). (2) Follow-up and survival. All the 1 337 patients were followed up for 31(range, 1?84)months. Of the 1 337 patients, 1 024 cases survived and 313 cases died. The 1-, 3-, 5-year survival rates were 94.8%, 85.5%, 80.1% for the 1 041 patients with CCI ≤3, versus 73.6%, 46.9%, 34.0% for the 296 patients with CCI ≥4, showing significant differences between them ( χ2=181.93, P<0.05). (3) Prognostic factors analysis of CRC patients undergoing operation. Results of univariate analysis showed that age, smoking history (having a history of smoking), tumor location (decending colon-sigmoid colon, recto-sigmoid junction-rectum), R 0 resection, tumor differentiation degree (moderate differentiation, well differentiation), clinical TNM staging, postoperative radio-therapy and chemotherapy, preoperational CEA and CCI were related factors for operative prognosis of CRC patients ( odds ratios=1.76, 0.71, 0.72, 0.61, 0.08, 0.39, 0.13, 3.02, 0.60, 2.41, 4.96, 95% confidence intervals as 1.39?2.23, 0.53?0.93, 0.52?0.99, 0.47?0.78, 0.06?0.11, 0.30?0.50, 0.05?0.31, 2.39?3.81, 0.48?0.76, 1.92?3.01, 3.97?6.20, P<0.05). Results of multivariate analysis showed that age >60 years, clinical TNM staging as stage Ⅲ?Ⅳ, preoperational CEA >5 μg/L and CCI ≥4 were independent risk factors for operative prognosis of CRC patients ( odds ratios=1.29, 1.88, 1.77, 2.84, 95% confidence intervals as 1.00?1.65, 1.45?2.44, 1.40?2.23, 2.20?3.67, P<0.05);tumor located in descending colon to sigmoid colon and recto-sigmoid junction to rectum, R 0 resection,tumor differen-tiation degree as moderate and well differentiation, postoperative radiotherapy and chemotherapy were independent protect factors for operative prognosis of CRC patients ( odds ratios=0.71, 0.72, 0.27, 0.50, 0.25, 0.56, 95% confidence intervals as 0.51?0.98, 0.56?0.93, 0.19?0.37, 0.38?0.65, 0.10?0.62, 0.44?0.70, P<0.05) (4) Establishment and evaluation of a nomogram prediction model based on CCI. Based on age, tumor location, R 0 resection, tumor differentiation degree, clinical TNM staging, postoperative radiotherapy and chemotherapy, preoperational CEA and CCI of multivariate analysis results, a nomogram prediction model for operative prognosis of CRC patients was established. The nomogram score was 1.0 for age >60 years, 18.0 for tumor located in proximal colon, 9.0 for tumor located in distal colon, 53.0 for non-R 0 resection, 62.0 for low differentiated tumor, 31.0 for morderate differentiated tumor, 32.0 for stage Ⅲ?Ⅳ of clinical TNM staging, 26.0 for no postoperative radiotherapy and chemotherapy, 4.6 for each increase of 100 μg/L in preoperative CEA and 12.6 for each increase of 1 score in CCI respectively. The total of different scores for risk factors was used to evaluate total 1, 3, 5-year survival rates. The ROC curve was drawn to evaluate the predictive ability for prognosis of nomogram model, with the AUC as 0.75 (95% confidence interval as 0.71?0.79, P<0.05). The C-index was 0.80 (95% confidence interval as 0.77?0.72). The calibration chart showed a good consistency between the probability of survival predicted by nomogram and the actual probability of survival. Conclusions:Age >60 years, stage Ⅲ?Ⅳ of clinical TNM staging, preoperational CEA >5 μg/L and CCI ≥4 are independent risk factors for operative prognosis of CRC patients. Tumor located in descending colon to sigmoid colon and recto-sigmoid junction to rectum, R 0 resection, tumor differentiation degree as moderate and well differentiation, postoperative radiotherapy and chemotherapy are independent protective factors for operative prognosis of CRC patients. The nomogram prediction model contributes to prediction of the survival of CRC patients.

Strain is the fundamental unit in microbial taxonomy. The functional diversity among strains has great influence on host phenotypes. With the development of microbiome research, knowing the composition and functional capacities of complex microbial communities at the strain level has become increasingly valuable in scientific research and clinical applications. This review introduces the principles of bioinformatics algorithms for strain analysis based on metagenomic data, the applications in microbiome research and directions of future development.
Algorithms ; Computational Biology ; Metagenome ; Metagenomics ; Microbiota/genetics*

Objective To evaluate the clinical effect of minimally invasive aortic valve replacement with Perceval sutureless aortic bioprosthesis in upper ministernotomy or right anterior thoracotomy. Methods From March to November 2022, the patients with simple aortic valve disease were enrolled in the Department of Cardiovascular Surgery of West China Hospital, Sichuan University. After preoperative evaluation, Perceval sutureless bioprosthesis was successfully used to perform aortic valve replacement through the upper ministernotomy or right anterior thoracotomy. The perioperative clinical data and ultrasonic measurement data of all patients were recorded. Results A total of 5 patients with simple aortic valve disease were included, including 3 females and 2 males, with a mean age of 71.2 years. Perceval sutureless bioprosthesis was successfully implanted in 5 patients, with a success rate of 100%. There were 3 patients receiving upper ministernotomy and 2 patients receiving right anterior thoracotomy. Two patients underwent ascending aortic plasty at the same time. The mean cardiopulmonary bypass time was 61.0 min, and aortic cross-clamping time was 32.2 min. All patients were discharged successfully without perivalvular leakage, atrioventricular block or stroke. Conclusion The implantation method of Perceval sutureless bioprosthesis is simple, which can effectively reduce the perioperative risk by shortening the overall operation time, cardiopulmonary bypass time and aortic cross-clamping time. At the same time, its clinical application has promoted the development and popularization of minimally invasive aortic valve replacement, which together with Perceval sutureless bioprosthesis effectively combinates surgical effect and minimally invasive treatment, and has a good clinical application prospect because of its reliable safety and effectiveness.

【Objective】 To explore the correlation of preoperative fibrinogen-to-albumin ratio （FAR） with the clinicopathological characteristics and prognosis of patients with rectal cancer so as to clarify the role of coagulation function and nutritional status in the occurrence and progression of tumors. 【Methods】 We retrospectively analyzed the clinicopathological data of 647 patients with rectal cancer who underwent radical resection in The First Affiliated Hospital of Xi’an Jiaotong University from January 1， 2013 to December 31， 2016. According to the optimal cut-off point value of FAR determined by receiver operating characteristic curve， 647 rectal cancer patients were divided into high FAR level group and low FAR level group. The correlation between different preoperative FAR levels and clinicopathological characteristics of rectal cancer patients was analyzed. Multivariate Cox regression analysis was used to analyze the independent risk factors for the prognosis of rectal cancer patients. R software was used to construct the nomogram， and C index and calibration chart were used to evaluate the prediction efficiency of the nomogram. 【Results】 Preoperative FAR levels had a good predictive value for the prognosis of rectal cancer patients. The area under ROC curve was 0.771， the optimal cut-off point was 0.092， and the Youden index was 0.446. There were statistically significant differences in age， T stage， N stage， TNM stage， preoperative CEA levels and preoperative CA19-9 levels between rectal cancer patients with different preoperative FAR levels （P<0.05）. The overrall survival and disease-free survival of rectal cancer patients with different preoperative FAR levels had statistically significant differences （P<0.05）. In the multivariate analysis， preoperative FAR levels （≥0.092， HR=3.298， 95% CI： 2.365―4.600， P<0.001）， age （≥60 years， HR=2.110， 95% CI： 1.479―3.012， P<0.001）， TNM stage （Ⅲ grade， HR=6.743， 95% CI： 2.771―16.771， P<0.001）， grade of differentiation （poor， HR=1.639， 95% CI： 1.104―2.432，P=0.014）， preoperative CA19-9 levels （≥37 U/mL， HR=2.205， 95% CI： 1.529―3.180， P<0.001） and not perform postoperative chemoradiotherapy（HR=1.792， 95% CI： 1.294―2.480，P<0.001） were independent risk factors of overall survival for patients with rectal cancer. OS and DFS nomograms of rectal cancer were established by the Rlanguage software， and the C-index was （0.781， 95% CI： 0.749―0.815； 0.754， 95% CI： 0.693―0.760）， respectively. The calibration curve of the nomogram showed high consistence between predictions and actual results for 1-year， 3-year， 5-year OS and DFS. 【Conclusion】 The preoperative high FAR level was an independent risk factor for the prognosis of patients with rectal cancer. It can be supplemented with pathological factors such as TNM stage as prognostic indicators for patients with rectal cancer， which may be helpful for clinicians to follow up or make beneficial treatment for rectal cancer patients.

Objective To evaluate the clinical efficacy of two-stage retrograde hybrid repair for acute aortic dissection involving the aortic arch complicated with distal malperfusion syndrome. Methods From May 2019 to December 2022, the patients presented with acute aortic dissection involving the aortic arch complicated with distal malperfusion syndrome treated in the Department of Cardiovascular Surgery of West China Hospital, Sichuan University were enrolled. After preoperative evaluation, all patients underwent priority emergency interventional surgery to improve distal malperfusion, and then underwent two-stage hybrid surgery to repair proximal aortic lesions. The perioperative clinical and imaging data were retrospectively analyzed. Results Five patients were collected, including 4 males and 1 female, with a median age of 58 years. The main manifestations were lower limb ischemia and renal insufficiency in 3 patients, and poor intestinal perfusion in 2 patients. All patients were given priority to interventional surgery to implant graft stents or bare stents and necessary branch artery intervention, and then successfully performed two-stage hybrid surgery, including type Ⅰhybrid surgery for 2 patients, type Ⅱ hybrid surgery for 1 patient and type Ⅲ hybrid surgery for the other 2 patients, with a success rate of 100.0%. All patients were discharged successfully, and the function of the organs with poor perfusion returned to normal. Only 1 patient recovered to grade 4 muscle strength of the diseased lower limbs upon discharge. No adverse events such as amputation, exploratory laparotomy and intestinal resection or long-term hemodialysis occurred. Conclusion The application of two-stage retrograde hybrid repair in the surgical treatment of acute aortic dissection involving the aortic arch complicated with distal malperfusion syndrome is safe and effective, and is helpful to improve the perioperative survival rate, and clinical outcomes of such patients.