The dental abrasive testing machine applies a V-like swing arm to driving the wearing part to move along the slope back and forth, which is connected with an eccentric wheel fixed on the crankshaft of the gear motor through a connecting rod. Various abraders can be held on the wearing part with an adjustable wearing pressure between 10 and 500g loaded on the specimen. During wearing, both abrader and specimen are immersed in the wearing medium. Before and after the test, the specimen is weighed and its wearing surface is recorded by a profilometer, then the weight loss and volume loss can be calculated.

Objective To investigate the clinical value of fast track surgery (FTS) in perioperative management of laparoscopic cholecystectomy in the plateau.Methods The clinical data of 88 patients with gall stone who received laparoscopic cholecystectomy at the No.115 Central Hospital of PLA from March 2011 to July 2012 were retrospectively analyzed.All the patients were randomly divided into the control group (44 patients) and the observation group (44 patients).Patients in the control group received traditional perioperative treatment,while patients in the observation group received FTS treatment.Differences in the operation time,time to out-of-bed activity,time for recovery of bowel function,duration of postoperative hospital stay,medical treatment cost and incidence of complications between the 2 groups were compared.The measurement data were shown in x ± s,and analyzed using the t test,and the count data were analyzed using the chi-square test.Results The operation time of the control group and the observation group were (63 ± 19)minutes and (59 ± 21)minutes,with no significant difference between the 2 groups (t =-1.34,P ＞ 0.05).The time for out-of-bed activity,recovery of bowel function,duration of postoperative hospital stay and medical treatment cost were (25 ± 6) hours,(36 ± 9) hours,(5.6 ± 1.3) days,(10.8 ± 1.1) × 103 yuan in the control group,and (10 ± 4) hours,(23 ± 5) hours,(3.1 ± 1.3) days,(7.9 ± 1.3) × 103 yuan in the observation group,with significant differences between the 2 groups (t =-3.81,-3.67,-6.40,-4.08,P ＜ 0.05).The incidences of complications in the control group and the observation group were 4.5％ (2/44) and 2.3％ (1/44),respectively,with no significant difference between the 2 groups (x2=3.01,P ＞ 0.05).Conclusion FTS can promote the recovery of patients,decrease duration of hospital stay and medical treatment cost without increasing incidence of complication for patients who received laparoscopic cholecystectomy in the plateau.

Objective To know the probability of water disinfection of railway water supply provided for themselves by using the chlorine dioxide generator based on chemistry way. Methods According to Technical Standard for Disinfection, filter membrane method was used. The water samples were collected from the railway water supply stations, the germicidal tests were conducted in laboratory and on site. Results In a contact time of 0.5 min, the disinfectant solution containing chlorine dioxide of 0.25 mg/L produced by the generator could meet the requirement of disinfection of drinking water. The generator could maintain chlorine dioxide at 0.3-0.5 mg/L in the pipeline of the water supply. The water quality was up to standard after disinfected. Conclusion The chlorine dioxide generator is suitable for water disinfection of railway water supply provided for themselves.

Objective To explore the relationship between alterations of neural network plasticity and spatial learning and memory functions in mouse models with depression-like behaviors.Methods C57Thy1-YFP/GAD67-GFP mice were randomized into control group(with no treatment)and chronic unpredictable mild stress(CUMS)group(n=15)subjected to CUMS for 8 weeks.Depression-like behaviors of the mice were assessed using sucrose preference test,open field test,and forced swimming test,and their spatial learning and memory abilities were evaluated using Morris water maze test.The changes in the firing patterns of different neuronal subtypes were detected in the central nucleus of the amygdala(CeA)and the prelimbic cortex(PrL)using whole-cell patch-clamp technique.Results Compared with the control mice,CUMS mice showed significantly decreased sucrose preference,total distance moved,number of grid-crossings,entries into the central area,and time spent in the central area in the open field test(P<0.01).In the forced swimming test,CUMS mice exhibited obviously shortened time of struggling,swimming,and climbing with increased immobility time.In Morris water maze test,CUMS mice showed significantly increased escape latency and path length,decreased percentage of distance and swimming time within the target quadrant,and increased first entry latency into the target zone and swimming time within the opposite quadrant.Exposure to CUMS resulted in significantly enhanced energy barrier and increased absolute refractory period and inter-spike interval of glutamatergic neurons in the CeA and GABAergic neurons in the PrL,while the opposite changes were observed in GABAergic neurons in the CeA and glutamatergic neurons in the PrL.Conclusion CUMS-induced depression may lead to plastic changes in the excitatory and inhibitory neuronal networks within the CeA and PrL to cause impairment of spatial learning and memory abilities in mice.

Objective To explore the relationship between alterations of neural network plasticity and spatial learning and memory functions in mouse models with depression-like behaviors.Methods C57Thy1-YFP/GAD67-GFP mice were randomized into control group(with no treatment)and chronic unpredictable mild stress(CUMS)group(n=15)subjected to CUMS for 8 weeks.Depression-like behaviors of the mice were assessed using sucrose preference test,open field test,and forced swimming test,and their spatial learning and memory abilities were evaluated using Morris water maze test.The changes in the firing patterns of different neuronal subtypes were detected in the central nucleus of the amygdala(CeA)and the prelimbic cortex(PrL)using whole-cell patch-clamp technique.Results Compared with the control mice,CUMS mice showed significantly decreased sucrose preference,total distance moved,number of grid-crossings,entries into the central area,and time spent in the central area in the open field test(P<0.01).In the forced swimming test,CUMS mice exhibited obviously shortened time of struggling,swimming,and climbing with increased immobility time.In Morris water maze test,CUMS mice showed significantly increased escape latency and path length,decreased percentage of distance and swimming time within the target quadrant,and increased first entry latency into the target zone and swimming time within the opposite quadrant.Exposure to CUMS resulted in significantly enhanced energy barrier and increased absolute refractory period and inter-spike interval of glutamatergic neurons in the CeA and GABAergic neurons in the PrL,while the opposite changes were observed in GABAergic neurons in the CeA and glutamatergic neurons in the PrL.Conclusion CUMS-induced depression may lead to plastic changes in the excitatory and inhibitory neuronal networks within the CeA and PrL to cause impairment of spatial learning and memory abilities in mice.

Background and Aims:Postoperative intra-abdominal infection(PIAI)is a common postoperative complication in abdominal surgery and a challenging issue worldwide,with a treatment failure rate of 68.3％and an in-hospital mortality rate as high as 40.8％.The key to managing this condition is early control of the infection source,debridement and adequate drainage.Delayed control of the infection source is an independent risk factor for predicting treatment failure.Many PIAI lesions are located deep within the abdominal cavity,lacking optimal routes for percutaneous drainage,and the risks and difficulties of reoperation are significant.Thus,controlling the infection source in PIAI is a difficult task.Here,the authors report the management of 4 PIAI patients treated with nephroscopic debridement and catheter irrigation and drainage via the sinus tract,aiming to provide clinical insights and references. Methods:The clinical data of 4 patients undergoing nephroscopic debridement,catheter irrigation and drainage for PIAI from October 2020 to September 2022 in the Department of Hepatobiliary and Pancreatic Surgery of the Second Affiliated Hospital of Guilin Medical University were retrospectively analyzed.Key techniques of nephroscopic management of PIAI were summarized and contextualized with relevant literature. Results:The 4 PIAI cases included a right-sided retroperitoneal abscess after catheter drainage for severe acute pancreatitis,a hepatic abscess at the liver raw surface after right hemihepatectomy,bile leakage and secondary duodenal fistula after laparoscopic choledocholithotomy and T-tube drainage,and a pancreatic abscess at the pancreatic raw surface after distal pancreatectomy with splenectomy.All patients underwent nephroscopic debridement and catheter irrigation and drainage via the sinus tract:guidewires were inserted into the drainage sinus tract,followed by a minimally invasive expansion drainage kit and nephroscopy;pus was irrigated out,and pus moss was clamped out with foreign body forceps under nephroscopy.Then,irrigation drainage tubes were placed under the guidance of the guidewire,and continuous irrigation and drainage were performed.The 4 patients underwent a total of 5 nephroscopic debridement and catheter irrigation and drainage procedures,with one case requiring two operations.The preoperative catheterization time ranged from 14 to 58 d,with an average of 38.4 d.One patient concurrently underwent choledochoscopy for stone extraction and biliary drainage via the T-tube sinus tract.The operative time ranged from 30 to 115 min,with an average of 67.4 min.Aside from one case of minor intraoperative bleeding,which stopped after injecting diluted norepinephrine solution into the sheath and blocking the sheath,there were no surgical complications in the other three cases.The postoperative drainage tube duration ranged from 7 to 30 d,with an average of 20.75 d.After treatment,all PIAI lesions disappeared,and no recurrence was observed during follow-up,which ranged from 16 to 40 months. Conclusion:Nephroscopic debridement and catheter irrigation and drainage via the sinus tract for PIAI is simple,feasible,and safe,allowing for direct visualization to avoid organ damage.It is effective in removing pus and necrotic tissue,replacing drainage tubes,and can be repeatedly performed with high efficiency and remarkable results.This method is particularly suitable for patients with postoperative abdominal drainage tube obstruction combined with encapsulated intra-abdominal fluid collections.

OBJECTIVE To explore the genetic basis for a family affected with Peutz-Jeghers syndrome (PJS). METHODS Genomic DNA was extracted from peripheral blood and oral swab samples from the patient and her relatives. Next-generation sequencing (NGS) was used to analyze 106 target genes by capturing the exons and adjacent intronic regions. Suspected pathogenic mutation was verified by NGS. RESULTS A missense STK11 mutation was detected in the proband, which was not reported previously. The mutation has caused substitution of Leucine by Proline. NGS has detected the same mutation in the mother but not among other relatives. CONCLUSION This hereditary case of PJS may be attributed to the missense mutation of the STK11 gene.

Objective To retrospectively analyse the outcomes following primary Sutureless technique used in our hospi-tal for neonates with total anomalous pulmonary venous connection(TAPVC)and sum up surgical operative experiences. Meth-ods Date were collected retrospectively in 42 neonates who underwent primary Sutureless technique for TAPVC between Janu-ary 2008 and December 2015. Cardiopulmonary bypass time,aortic clamped time,velocity of pulmonary veins and other relat-ed data were recorded during and after operation. Results There were 31 males and 11 females with median age of 8. 0 days old,of whom 25 were supracardiac TAPVC(59. 5％)and 17 were infracardiac TAPVC(40. 5％). After operation, 1 neonate died and none suffered from pulmonary vein obstruction(PVO). In follow-up period,there was 1 neonates suffered from PVO. Six neonates came back to hospital again because of septicemia,poor wound healing,bronchopneumonia and incomplete intesti-nal obstruction. Conclusion Sutureless technique is a wise surgical strategy for neonates with TAPVC for better outcomes and decreasing postoperative mortality rate and recurrence rate of PVO.