0.05).Conclusion DTI can noninvasive detect the potential disorder of corpus eallosum in vivo,thus providing useful information to differentiate the cerebral ischemia disease from multiple sclerosis.

Abstract: Objective To understand the distribution and drug resistance of pathogenic bacteria of bloodstream infection in Fujian Province, and to provide reference for clinical rational drug use. Methods Bacteria identification and antimicrobial susceptibility test were carried out on the isolated strains of blood culture samples in 31 medical institutions in Fujian Province according to the unified plan. The data were statistically analyzed by WHONET 5.6 software according to the Clinical and Laboratory Standards Institute (CLSI) drug sensitivity executive standard in 2021. Results After removing the duplicate strains, 10 356 strains of bacteria were collected, including 3 668 strains of Gram-positive bacteria (35.4%) and 6 688 strains of Gram-negative bacteria (64.6%). The top 5 bacteria are Escherichia coli, Klebsiella pneumoniae, coagulase negative Staphylococcus, Staphylococcus aureus and Pseudomonas aeruginosa. In this study, the detection rate of methicillin-resistant Staphylococcus aureus (MRSA) was 24.5%, and the detection rate of methicillin-resistant coagulase-negative Staphylococcus aureus (MRCNS) was 76.8%. Vancomycin, teicoplanin and linezolid resistant staphylococci were not found. The detection rate of penicillin resistant Streptococcus pneumoniae was 3.2%. Vancomycin resistant Enterococcus faecalis and Enterococcus faecium were 0.8% and 1.1% respectively. The resistance rate of Escherichia coli to carbapenems was 0.8%, and the resistance rate to levofloxacin was 41.9%; the resistance rate of Klebsiella pneumoniae to carbapenems was 15.0%. The resistance rate of Acinetobacter baumannii to carbapenems was 45.1%; the detection rate of Pseudomonas aeruginosa was only 14.2%, and it maintained a high sensitivity to most drugs. Conclusions Most bloodstream infections in Fujian Province are caused by Escherichia coli, Klebsiella pneumoniae and Staphylococcus. The drug resistance of some strains is not optimistic, so we should continue to strengthen the clinical application management of antibiotics and use them correctly and reasonably. Keywords: Bloodstream infection; bacteria; antibiotics; drug resistance monitoring

One factor at a time design and first order exponential model were applied to investigate the effects of the four major factors(temperature,ionic strength,pH and osmo-regulator) in the preservation process of nitrite oxidization bacteria(NOB),and a first order decay kinetics was introduced.The result showed that the anoxic decay rate of nitrifying bacteria reduced from 0.25 to 0.015,the half life was extend to 53d at 4℃,pH7.60,ionic strength 0.035mol/kg.The protecting effect of glycerin showed obviously better than that of other cryoprotectants at 4℃.

Objective To explore the feasibility of artificial silastic framework(SF)in repair of large area of tracheal wall defects.Methods Twenty healthy adult dogs with tracheal defects for 2.5 cm?6.0 cm-3.0 cm?6.0cm were randomly and equally divided into experimental group(repaired with SF combined with sternohyoid fasciae)and control group(repaired with T-silastie tubule combined with sternohyoid fascial flap).After the operation,the animals were sacrificed at the 4th,8th,16th,24th, and 48th weeks respectively for harvesting the tracheae that were used for tracbeoscopically observing in- flammatory reaction of the repaired defect area and light microscopically observing epithelium healing on the repaired defect area.Results In the experiment group,the repaired trachea was smooth,without proliferation of granulation;and at the 8th week,the repaired defect area was covered with epithelial cells,with good functional recovery of respiration,phonation and deglutition.In the control group,there was obvious proliferation of granulation on the tracheal surface near anterior and posterior ends of T-silas tic tubule.The animals were under asphyxia to die with extraction of T-silastic tubule.Conclusions SF has excellent tracheal skeletal function.In the meantime,SF combined with sternohyoid fasciae is a simple but effective method for repair of large area of tracheal wall defects.

Objective To explore the effect of protoporphyrin Ⅸ zinc(Znpp) on hyperoxic lung injury in preterm rats.Methods Three-day-old preterm SD rats were randomly assigned to room air control group(group Ⅰ)hyperoxia control group(oxygen≥900 mL/L)(group Ⅱ),room air plus Znpp group(group Ⅲ),hyperoxia plus Znpp group(group Ⅳ).Group Ⅲ and group Ⅳ were injected intraperitoneally with ZnPP 45 ?mol/kg each day.After the third day and the 7th day of exposure,the activity of heme oxygenase-1(HO-1) and the percent of carboxyhemoglobin(HbCO) in the lungs,the lung wet weight /dry weight ratio(W/D),tumor necrosis factor-?(TNF-?),total protein and malondialdehyde(MDA) in bronchoalveolar lavage fluid were determined and lung histophathological changes were examined in all groups.Results On the third day,compared with group Ⅰ the activity of HO-1 and the percent of HbCO in the lungs,W/D,TNF-?,total protein and MDA,all greatly rised in group Ⅱ(Pa

Objective To investigate the change of oxidation system and antioxidation system in mesangial proliferative glomerulonephritis(MsPGN) induced by anti-Thy1.1 antibody,and further to study the intervention of rosmarinic acid(RAD).Methods Anti-THy1.1 serum was produced,and then intravenously injected into rats for establishing an experimental model of MsPGN.The experiment was designed for control with or without RAD,glomerulonephritis with or without RAD,respectively.The activity of superoxide dismutase(SOD) and the content of malondialdehyde(MDA) in tissue homogenate were detected by spectrophotomerty.Results The activity of SOD significantly decreased,while the content of MDA increased in MsPGN.RAD could inhibit oxidation in the mesangial cells.Conclusion Lipid peroxidation participates in MsPGN and RAD can control the changes of the mesangial cells and show the activity of antioxidation.

Objective To find out the causes of the failure of the replanted finger and to increase the survival rate of replantation.Methods The trauma,operation condition and nursing care after operation of the 24 failure cas- es of 31 replantation of severed fingers that have been treated in this hospital from January 1999 to December 2006 were retrospectively analyzed.Results Of the 31 necrotic fingers,there were 21 necrotic fingers caused by untimely treatment of vascular articulo,7 by infection,1 by smoking and 2 by uncooperative treatment because of out-of-bed activity.There were 9 replantation of fingers loss of blood supply in one day,12 fingers from one day to three days, 8 fingers from four days to seven days,2 fingers more than nine days.Conclusion The operation indication should be strictly mastered.There should be a complete debridement and haemostasis during the operation,the quality of vascular anastomose should be improved and the pressure of the anastomosing vascular should be avoided.Strict ob- servation after operation,intensive nursing and timely treatment of vascular articulo are the key factors for improving the survival rate of replantation of severed finger.

Objective To compare the curative effect of high ligation+exfoliation and subfascial endoscopic perforator surgery(SEPS)for superficial varicose veins in calf+invagination spot-striping surgery in great venous varicosity.Methods Study group(42 patients)accepted SEPS+invagination spot-striping surgery and control group (42 patients)accepted traditional surgeries.Operation duration,bleeding volume in operation,the time of beginning movement away from bed after operation,hospitalization duration,the degree of pain,the scar,the recrudescence af- ter operation and the instance of the ulcer heals of two groups were compared.Results Operation duration,bleeding volume in operation,the time of begin movement away from bed after operation and hospitalization durations of study group were significantly lower than those of control group(P0.05).All of the patients in study group recovered without severe syndromes such as venous thrombosis,skin necrosis,lower limb functional disorder etc.They had no recrudesce after 4～16 months and were satisfied with the curative effect.Con- elusions The clinical curative effect of SEPS+invagination spot-striping surgery in great venous varicosity is superi- or to that of traditional operation and it has the advantages such as minor wound,few scars,light pains,short hospi- talization duration,without recrudescence,the ulcer heals quickly and so on.

Abstract: Objective　To investigate the molecular characteristics and drug resistance of non-O1/non-O139 Vibrio cholerae in Zhongshan City, and to provide laboratory basis for cholera prevention and control. Methods　The strains of non-O1/non-O139 Vibrio cholerae isolated from sporadic patients and aquatic products from 2015 to 2021 in Zhongshan city were collected. The identification and cluster analysis of the strains were analyzed by matrix assisted laser desorption/ionization time of flight mass spectrometry (MALDI-TOF-MS), the ctxA virulence gene of strains were detected by real-time fluorescence quantitative PCR, the cluster analysis of the strains was analyzed by pulsed-field gel electrophoresis (PFGE), and the drug resistance of the strains were analyzed by microbroth dilution method. Results　From 2015 to 2021, 33 strains of non-O1/non-O139 Vibrio cholerae were isolated from Zhongshan City, including 28 strains from sporadic patients and 5 strains from aquatic products. Through MALDI-TOF-MS identification, 33 strains of non-O1/non-O139 Vibrio cholera can be identified to the level of species, and the identification results were all Vibrio cholerae. Among 33 non-O1/non-O139 Vibrio cholerae strains, 1 strain carried the ctxA virulence gene. The drug-resistant strains accounted for 69.7% (23/33), and the multidrug resistant strains accounted for 18.2% (6/33). A total of 7 kinds of drug resistance spectrum were produced, including 3 kinds of multidrug resistant spectrum, and showed drug resistance to 8 antibiotics, among which the resistance rates to streptomycin, cefazolin and compound sulfamethoxazole were above 30%. The 33 strains of non-O1/non-O139 Vibrio cholerae were divided into 32 PFGE fingerprints with a similarity ranging from 61.7% to 100%. MALDI-TOF-MS cluster analysis divided 33 non-O1/non-O139 Vibrio cholerae strains into two clusters. Conclusions The results of molecular typing of non-O1/non-O139 Vibrio cholerae in Zhongshan City presented diversity, and no significant correlation was found between PFGE and MALDI-TOF-MS cluster analysis. The strains demonstrated various degrees of resistance to certain antibiotics, and there were multidrug-resistant and toxigenic strains. Therefore, it is necessary to alert to the harmfulness of non-O1/non-O139 Vibrio cholerae and enhance monitoring.

Small interfering RNA (siRNA) is the initiator of RNA interference and inhibits gene expression by targeted degradation of specific messenger RNA. siRNA-mediated gene regulation has high efficiency and specificity and exhibits great significance in the treatment of diseases. However, the naked or unmodified siRNA has poor stability, easy to degrade by nuclease, short half-life, and low intracellular delivery. As an emerging non-viral nucleic acid delivery system, ionizable lipid nanoparticles play an important role in improving the druggability of siRNA. At present, one siRNA drug based on ionizable lipid nanoparticles has been approved for the treatment of rare disease. This review introduces the research progress in ionizable lipid nanoparticles for siRNA delivery, focusing on the effect of each component of lipid nanoparticles on the efficiency of siRNA-mediated gene silencing, which provides new references for the studies on ionizable lipid nanocarriers for siRNA delivery.