Objective To study a rapid method for determination of trace formaldehyde in drinking water by oscilloscopic polarography.Methods In the base solution of0.01mol/L H 3 PO 4 ,the reaction product of formaldehyde and phenylhydrazine hydrochloride on the drop mercury electrode revealed a sensitive second order derivative polarographic wave at a pick electric potential-0.76V(VS?SCE).The optimum conditions and interference by other coexisting ions were analyzed.Results The de-tection limit,linear range,recovery rate,relative standard deviation(RSD)of the method were0.002mg /L,0.005-0.25mg /L,94.0%-103.0%,and0.05).Conclusion The method was simple,rapid,sensitive and highly specific.The analytical speed was about 50-60samples /h,which was suitable for the determination of trace formaldehyde in drinking water.

Objective To establish the rat overlap syndrome (OS) model of intermittent hypoxia (IH) combined with pulmonary emphysema and to explore its connection with hepatic oxidative stress, inflammatory status in the live and coagu?lation profile. Methods Male Wistar rats (n=60) were randomly divided into four groups:control group (A), IH group (B), pulmonary emphysema group (C) and OS group (D). The rat model of pulmonary emphysema was established by exposing rats in smoke for 16 weeks. From the 13th week, pre-programmed intermittent hypoxia/re-oxygenation (IH/ROX) exposure was given in the meantime of smoke exposure in OS group. Liver tissues were sectioned or triturated for pathological scoring or for detecting expression levels of superoxide dismutase (SOD), catalase (CAT) and malondialdehyde (MDA) respectively. Se?rum levels of coagulant/anticoagulant factors such as antithrombin (AT), fibrinogen (FIB), von Willebrand factor(vWF) and FactorⅧ(FⅧ) were also evaluated using biochemistry analysis. Results The levels of pathological scores and coagulant factors(FIB, FⅧ:C and vWF:Ag)were significantly higher in group D than those in group A, B and C. The values of SOD, CAT and AT were significantly lower in group D than those in other three groups. Serum levels of FIB, vWF:Ag, FⅧ:C and AT:A correlated with SOD(r equal to-0.905、-0.941、-0.946 and 0.817 respective,P<0.01). Conclusion In rat overlap syndrome when IH combined with pulmonary emphysema, hepatic inflammation and coagulability present mutual promotion effect and produce a more significant liver-derivative inflammatory and prothrombotic status.

Objective To illustrate more accurately the feasibility of DNA barcode technology in species identification in different geographical areas.Methods Four plague host animals were selected from three plague natural foci in Inner Mongolia for DNA barcode comparison,GC base content,codon preference and genetic distance calculation,and a phylogenetic tree was constructed.Results Compared between different foci of A llactaga sibirica,the difference of base content was statistically significant (F =5.34,P ＜ 0.05);the variation of Meriones unguiculatus focus Allactaga sibirica base content was larger,and compared with other foci Allactaga sibirica,the difference was statistically significant (all P ＜ 0.05).Different foci between one species rarely exist in codon sites.The genetic distance of intraspecific was less than 1％,and the genetic distance of interspecific was more than 18％.Conclusions DNA barcode of each species is specific,with no interspecific species sharing,and does not change with geographical position.Molecular identification of plague host animal is effective by DNA barcode.

Objective To determine a method for amplification of cytochrome C oxidase subunit Ⅰ (CO Ⅰ) gene of Brandt's vole.Methods 发he Brandt's Voles were captured in Abagaqi Xilingol League Inner Mongolia,and DNA was extracted from liver tissue.CO Ⅰ gene was amplified by nested PCR and sequenced afterwards.Results A band of 657 bp and 1 132 bp was amplified by internal and external PCR primers,respectively,which were consistent with expected sizes.A total of 12 segments of Brandt's Vole CO Ⅰ gene sequences were amplified by PCR and verified by sequencing.一he sequence number was KF182196-KF182207 in GenBank.After gene sequence alignment of the 12 CO Ⅰ gene sequences,it was found that the similarity was 100％,and no base mutation.Conclusion CO Ⅰ gene of Brandt's Vole could be amplified by nested PCR without pseudo gene.

OBJECTIVE To study the drug resistance,drug-resistant genes and(disinfectant)-resistant genes of(MRS)A.METHODS The drug resistance and mecA gene of the ?-lactamase and aac(6′)/aph(2″),aph(3′)-Ⅲ,ant(4′,4″) genes of aminoglycoside and qac(A/B) disinfectant-resistant genes were(detected) in 47 strains of MRSA.(RESULTS) In all 47 strains of MRSA,46 MRSA isolates were mecA positive,39 MRSA isolates were aac(6′)/aph(2″) positive,30 MRSA isolates were aph(3′)-Ⅲ positive,6 MRSA isolates were ant(4′,4″) positive,and 19 MRSA isolates were qac(A/B) positive.CONCLUSIONS MRSA is multiple-drug resistant.The main resistant mechanisms of MRSA to aminoglycosides and disinfectant are related to the drug-resistant genes of aminoglycoside and disinfectant-resistant genes.Clinic physician must pay attention to the diagnosis and(therapy) of MRSA,and control the hospital infection.

BACKGROUND:In recent years,with the development of 3D printing,surgical surgery has become personalized and accurate.3D printed guide template technique can realize preoperative planning and intraoperative navigation,making surgery more accurate.In clinical orthopedic surgery for moderate and severe stiff scoliosis,there is still a problem that the accuracy of screw placement is not high,resulting in screw loosening and even nerve complications.There are few studies on 3D printed guide template technique to guide screw placement in surgery for severe stiff scoliosis. OBJECTIVE:To evaluate the clinical effect of the 3D printed guide template technique combined with multiple posterior derotation in the treatment of severe rigid scoliosis. METHODS:The clinical data of six patients with severe scoliosis undergoing 3D printed guide template technique of pedicle screw combined with multiple posterior derotation were retrospectively analyzed.There were 3 males and 3 females,with a mean age of(18.17±3.49)years(range,15-23 years).The changes of parameters related to lateral bending were analyzed at postoperative 2 weeks and 18 months,and the results were obtained by statistical analysis. RESULTS AND CONCLUSION:(1)The operation time was 280-540 minutes(mean 340.83±102.20 minutes).The intraoperative blood loss was 1 000-4 000 mL(mean 2 000.00±1 073.70 mL).The fixed segments were 9-14 vertebral bodies(mean 11.83±1.72),and no screw loosening occurred during the operation.(2)All patients were followed up.At postoperative 2 weeks,the anteroposterior and lateral radiography of the whole spine showed that the cobb angle,the distance between the vertical line of C7 on the coronal plane and the median line of S1,the distance between the vertical line of C7 in the sagittal plane and the posterior edge of S1,apical vertebral translation,thoracic kyphosis,and lumbar lordosis were significantly corrected.The average correction rate of the cobb angle in the main curve was 62.22%.After 18 months of follow-up,there was no significant change in all parameters compared with 2 weeks after operation;the orthopedic effect was satisfactory,and there was no infection or internal fixation fracture.(3)There was one case of delayed wound healing;scar healing appeared after dressing change treatment;no neurological complications occurred.(4)The results show that the 3D print-guide template combined with multiple posterior rod derotation technique is safe and effective in the treatment of severe rigid scoliosis,and the correction effect is satisfactory.

Objective:To compare the efficacy and safety of drug-coated balloons (DCB) combined with bare metal stents (BMS) and BMS only for superficial femoral atherosclerosis obliterans.Methods:The clinical and follow-up data of 80 patients (82 limbs) who received combined treatment or BMS implantation at Cardiovascular Surgery Department of China Japan Friendship Hospital from Jan 2017 to Aug 2022 were retrospectively analyzed.Results:43 patients (43 limbs) were included in combined treatment group. 37 patients (39 limbs) were in BMS only. The average lesion length of combined group was longer than BMS group (19.54±7.04 cm vs. 16.25±6.43 cm, P=0.031). The primary patency rate of combined group at 36 months was not statistically different with BMS only group (56.9% vs. 38.5%, P=0.171). The subgroup analysis of superficial femoral artery TASC C/D (Trans-Atlantic Inter-Society Consensus) and CTO (chronic total occlusion) lesions indicated that efficacy of the combined group was superior to BMS only group. The patency rates of the combined group compared with the BMS group at 36 months were 57.6% vs. 23.8%, P=0.046, 60.2% vs. 31.4%, P=0.028, respectively. There was no significant difference in the FCD-TLR (free from clinical driven target lesion revascularization) between the two groups at 36 months (72.6% vs. 66.5%, P=0.706). There was no significant difference in major adverse events between the two groups ( P>0.05). Conclusion:Paclitaxel drug-coated balloon combined with bare metal stent is a safe and effective treatment for superficial femoral atherosclerosis obliterans, which is superior to bare metal stent, especially in TASC C/D and chronic total occlusive lesions.

Objective:Donor cytomegalovirus (CMV) serological negative status may have an adverse effect on the outcome of allogeneic hematopoietic stem cell transplantation (allo-HSCT), while there is inadequate data for Chinese people. This study is to explore the impact of donor CMV serological status on the outcome of CMV seropositive patients receiving allo-HSCT.Methods:Our study retrospectively analyzed 16 CMV seropositive patients with hematological malignancies receiving allogeneic grafts from CMV seronegative donors (antibody IgG negative) at Peking University People′s Hospital from March 2013 to March 2020, which was defined as D -/R + group. The other 64 CMV seropositive patients receiving grafts from CMV seropositive donors at the same period of time were selected as matched controls through a propensity score with 1∶4 depending on age, disease state and donor-recipient relationship (D +/R + group). Results:Patients in D -/R + group developed CMV DNAemia later than patients in the D +/R + group (+37 days vs. +31 days after allo-HSCT, P=0.011), but the duration of CMV DNAemia in D -/R + group was longer than that of D +/R + group (99 days vs. 34 days, P=0.012). The rate of CMV reactivation 4 times or more in D -/R + group was 4/16, significantly higher than that of D +/R + group (4.7%, 3/64, P=0.01). The incidences of refractory CMV DNAemia (14/16 vs. 56.3%, P=0.021) and CMV disease (4/16 vs. 4.7%, P=0.01) in D -/R + group were both higher than those in D +/R + group. In addition, the application of CMV-CTL as the second-line antiviral treatment in D -/R + group was more than that in D +/R + group. Univariate analysis and multivariate analysis suggested that CMV serological negativity is an independent risk factor for refractory CMV DNAemia and the duration of CMV infection. The cumulative incidence of aGVHDⅡ-Ⅳ, cGVHD, 3-year probability of NRM, overall survival, and the cumulative incidence of relapse were all comparable in two groups. Conclusions:Although there is no significant effect on OS and NRM, the incidence of refractory CMV DNAemia, the frequency of virus reactivation, and the development of CMV disease in D -/R + group are higher than those in controls. Therefore, CMV seropositive donors are preferred for CMV seropositive patients.

Objective To evaluate diagnostic method and treatment strategy for free floating thrombus in carotid artery.Methods From Ju12016 to Oct 2017,7 patients with free floating thrombus in carotid artery was diagnosed at our department.The medical history,symptoms,diagnosis,treatment strategy and prognosis of those patients were analyzed retrospectively.Results Among 7 patients,4 were symptomatic;4 patients were concomitant with severe carotid artery stenosis and 3 with mild to moderate stenosis.3 received carotid endarterectomy and patch angioplasty.4 received carotid artery stenting with distal cerebral protection divice.There was no perioperative and 30-day stroke,myocardial infarction,death or hyperperfusion syndrome occurred.The 12-month follow up showed no restenosis,no free floating thrombus recurrence and no ischemic cerebrovascular event.Conclusion Free floating filling defect in carotid artery is a typical sign for unstable plaque.Both carotid endarterectomy and carotid artery stenting can be used for the treatment of free floating thrombus.