Objective To establish a loop-mediated isothermal amplification (LAMP) assay for rapid detection of the West Nile virus (WNV).Methods WNV genome (position nt 1 021 to nt 1 240) was synthesized by a PCR-based gene synthesis method.The synthetic fragments included 6 pairs of LAMP primer recognizing 8 primer sites of WNV genome.The LAMP gene amplification was carried out using a real-time PCR system at 63℃ for 60 min,then the amplification was terminated at 80℃ after 2 min.The amplification products were observed by agarose gel electrophoresis.The sensitivity and specificity of LAMP assay were compared with those of conventional PCR.Results The LAMP assay took less than 20 min,and the amplification product took on a ladder-like electrophoresis pattern.The sensitivity of LAMP assay was 10-fold higher than that of conventional PCR,and the detection limit of LAMP was 9.23 copies/?l.The specificity of WNV-specific LAMP assay was demonstrated by the negative amplification results from dengue virus and Japanese encephalitis virus,both were closely related members of the Flavivirus family.Conclusion LAMP assay is rapid,cost-effective,highly sensitive and specific in detecting genes of interest,and is of great significance for WNV surveillance,especially for grass root units and on-sport surveillance.

The effect of cognition need on information seeking behaviors of information users and the difference in behaviors of information users were investigated in 184 undergraduates from the same grade with different back-grounds of subjects using the cognition need scale and undergraduates information-seeking behaviors scale ,respec-tively.The data were analyzed by descriptive statistical analysis, correlation analysis, rank test, and multivariate linear regression analysis , respectively , showing that the cognition need is significantly correlated with the informa-tion seeking behaviors of undergraduates in terms of information evaluation, information searching, information management and information use .

Objective To investigate the inhibitory effect of DHA and its mechanism of apoptosis induced by DHA on human gastric cancer cell SGC-7901.Methods The survival rate of tumor cells was evaluated by MTT assay,cell morphology of apoptotic cell was observed with Hoechest 33258 staining.The contents of MDA and GSH were measured respectively by TBA and DTNB assay.Flow cytometry was used to detect the rate of apoptotic cell and intracellular variation of ROS level.Results After being treated with different concentrations of DHA,the survival rate of tumor cells was decreased in a dose-dependent manner and apoptosis was induced.The morphological characterizes of apoptotic cells were chromatin condensation and formation of apoptotic bodies.Intracellular MDA content was increased in the treated cells compared with control group,whereas GSH was decreased.After treated with 80 ?mol?L-1 DHA 5 h,flow cytometic analysis showed ROS peak and NAC could block the generation of ROS.Conclusion DHA can inhibit the growth of human gastric cancer cell SGC-7901 via inducing apoptosis.The increase of lipid peroxidation production and ROS may play an important role in apoptosis of the cells.

Objective:To study the factors influencing the happiness of dementia patients and their caregivers,provide guidance for improving their well-being.Methods:A total of 94 pairs of patients and their caregivers who were admitted to the neurology department of Peking Union Medical College Hospital from April 2015 to April 2016 were selected, the demographics of each patient and their caregivers were recorded. The Mini-Mental State Examination(MMSE) of patients with dementia, Role of Overload Scale(ROS) of caregivers, Dyadic Relationship Strain(DRS), Quality of Life for Dementia(QOL-D), Self-Evaluation Scale-Depression(CES-D) were recorded. Layered linear model was used to make regression analysis between the influencing factors and the scores of QOL-D and CES-D.Results:The results of the multi-layer linear model of uncontrolled variables in the fixed effect model: the results of QOL-D suggested that the score of patients with dementia was β 1j= 31.01±0.77, and the score of caregivers was β 2j= 35.15±0.88; the results of CES-D suggested that the scores of dementia patients and caregivers were β 1j = 14.55 ± 1.03 and β 2j = 13.11 ± 1.44, respectively. The random effects model suggested that there were statistical differences in the heterogeneity of the QOL-D score and the CES-D score variance component for dementia patients and caregivers (χ 2 values were 98.94-168.06, P<0.01). It indicated that the data was heterogeneous, adjusting the level 2 model, and the final results in the adjusted regression analysis suggested: caregiver relationship pressure (DRS), dementia patient self-awareness assessment (MMSE), caregiver care-related stress (ROS), dementia patient relationship stress (DRS) significantly affected the quality of life score (QOL-D) in both well-being ( β values were -3.22-0.43, P<0.05). Dementia patient relationship stress (DRS), caregiver-related stress (ROS), and caregiver relationship stress (DRS) significantly affected depressive symptoms in both well-being ( β values were 5.34, 3.26, 1.62, P<0.05). Conclusions:A comprehensive assessment of dementia patients and caregivers is needed. The combined family relationship is tense and the pressure associated with caregivers needs to be psychologically counseled.

Objective To observe the contrast sensitivity (CS) of patients with branch retinal vein occlusion (BRVO) without involving the macular region.Methods 92 BRVO patients (93 eyes) and 56 cases (112 eyes) without eye diseases (control group) were included in the study.According to different region,BRVO patients were divided into the nasal BRVO group (31 eyes) and temporal BRVO (62 eyes) group,and the average corrected visual acuity was 1.02 ± 0.13 and 0.98 ± 0.12 respectively.According to the type of ischemia,BRVO patients were divided into the nonischemic BRVO group (58 eyes) and ischemic BRVO group (35 eyes),the average corrected visual acuity was 1.01 ± 0.14 and 0.99 ± 0.12 respectively.The average corrected visual acuity of the control group was 1.03 ± 0.11.There was no statistically significant difference of the average corrected visual acuity between nasal BRVO group,temporal BRVO group and control group (F=3.03,P =0.06),and between nonischemic BRVO group,ischemic BRVO group and control group (F=1.60,P=0.20).Contrast sensitivity (CS) was measured by OPTEC 6500 vision tester (Stereo Company,USA) under the standard lighting conditions and different spatial frequencies including low (1.5 and 3.0 c/d),medium (6.0 c/d) and high frequencies (12.0 and 18.0 c/d).Results The CS under each spatial frequency of the nasal BRVO group was the same as the control group (t=4.25,9.48,3.08,5.86,0.94;P＞0.05),but the CS under each spatial frequency of the temporal BRVO group was different from the control group (t=8.59,19.11,10.38,17.28,6.01;P＜0.05).The CS under high spatial frequency of the temporal and nasal BRVO group was statistically different (t=11.42,6.95;P＜0.05).The CS under each spatial frequency of the ischemic BRVO group was different from the control group (t=8.88,10.56,11.64,19.06,6.67;P＜0.05).The CS under 6,12 and 18 c/d spatial frequency of the nonischemic BRVO group was statistically different with the control group (t =10.14,11.54,2.82;P＜0.05).The CS under 12 and 18 c/d spatial frequency of the nonischemic BRVO group was statistically different with the ischemic BRVO (t=7.52,3.84;P＜0.05).Conclusions The CS of the temporal BRVO and ischemic BRVO decreased more significantly under each spatial frequency.CS is a better indicator to evaluate the visual function than the visual acuity in BRVO without involving the macular region.

Objective To explore the value of contrast-enhanced ultrasound(CEUS) in the evaluation of the renal cortical perfusion in rabbits in low temperature conditions.Methods 20 New Zealand rabbits were randomly divided into five groups,4 rabbits in each group:1) with the first group as the control group (under the conditions of room temperature) ; 2)The second group was treated under-15℃--23℃ for 8hours; 3)the third group was treated under-15℃--23℃ for 4 hours; 4)the fourth group was treated under-6℃--14℃ for 8 hours; 5) the fifth group was treated under-6℃--14℃ for 4 hours.SonoVue was injected via the ear vein at a dose of 0.1 ml/kg,the renal perfusion imaging was made,observing the dynamic image of 0-3 min after the injection and analyzing the time-intensity curves(TIC)obtained from the following parameters:the slope rate of ascending curve(A),the slope rate of descending curve(α),area under the curve (AUC),time to peak (TTP),and derived peak intensity(DPI).Results Compared with the control group,the A,α of the second and the fourth group were significantly decreased (P ＜ 0.05),while the AUC was significantly increased (P ＜ 0.05) and the TTP was significantly prolonged(P ＜0.05),for the third and the fifth group,only the A was decreased (P ＜0.05),and the DPI in each group showed no significant difference.Compared with the third and the fourth group,the AUC of the second group was increased and the TTP was prolonged (P ＜0.05).Conclusions Contrast-enhanced ultrasound can reflect the earlier renal cortical hemodynamic changes in rabbits in the low-temperature conditions,and is of great value for the early diagnosis of renal damage caused by low temperature.

Objective To review our experience in correction of pectus excavatum.by Nuss procedure without thoracoscopic assistance.Methods 412 patients with pectus excavatum were surgically corrected using Nuss technique without thoracoscopic assistance.There were 329 boys and 83 girls with average age of 7 years and 8 months ( range from 2 years and 8 months to 28 yeats and 5 months).The bars were removed after surgery in 102 patients.Results The operation in all patients had been performed successfully without any severe complications The average time of the operation was 40 minutes.The average blood lose during operation was ( 10 ±2) ml.Conclusion Nuss procedure without thoracoscopic assistance is safety and effective.It could be minimize the trauma and shorter operating time.

Objective To understand the disinfectant resistance of clinically isolated Escherichia coli (E.coli)and carriage of disinfectant resistance genes.Methods Disinfectant resistance gene sugE (c ),sugE (p ),qacEΔ1 ,and qacE of 82 isolates of E.coli were detected with polymerase chain reaction (PCR),minimal inhibitory concentra-tions (MICs)were measured with agar dilution methods.Results Among 82 E.coli isolates,positive rates of dis-infectant resistance gene sugE (c ),sugE (p ),qacEΔ1 ,qacE,sugE (c )+qacEΔ1 ,and qacE+qacEΔ1 +sugE (c ) were 84.15% (n=69),1 .22% (n=1),76.83% (n=63),73.17 % (n=60),68.29% (n=56),and 59.76% (n=49)respectively.There was no significant differences in carriage status of four disinfectant resistance genes be-tween extended-spectrumβ-lactamases (ESBLs)-producing and non-ESBLs-producing strains,as well as cefepime sensitive and resistant strains (all P >0.05);MIC values of benzalkonium chloride,cetylpyridinium chloride,am-monium bromide,and triclosan for 82 isolates of E.coli were all > standard stain;MIC values of chlorhexidine for 32 isolates of E.coli were all > standard stain,for 50 other E.coli strains were all ≤ standard strain.There were no significant difference in MIC values of benzalkonium chloride,cetylpyridinium chloride,ammonium bromide,and triclosan between ESBLs-and non-ESBLs-producing strains,as well as cefepime sensitive and resistant strains(all P >0.05);while MIC values of chlorhexidine showed a significant difference (both P <0.05).Conclusion Detection rates of disinfectant resistance gene qacE,qacEΔ1 ,and sugE(c)in E.coli from clinical specimens are high,MICs of disinfectants such as benzalkonium chloride for E.coli are generally higher than standard strain.

Objective: To investigate protective effects of nicotinamide mononucleotide (NMN) on ethanol-induced DNA damage in L02 cells, so as to provide the evidence for adjuvant therapy of NMN on alcoholic liver diseases. Methods: L02 cells were pretreated with different concentrations of NMN (0, 1, 2, 4 and 8 mmol/L) for 6 h, and then were exposed to 0.4% ethanol for 12 h. The treated cells were divided into the control group, 0.4% ethanol group and different concentrations of NMN groups. Cell viability was analyzed using trypan blue staining for determining the concentration of NMN as a protective agent. The effects of NMN on ethanol-induced DNA damage in L02 cells were evaluated using immunofluorescence detection and reactive oxygen species (ROS) assay. L02 cells were exposed to 0.4% ethanol for 12 h, cultured in a medium containing a protective concentration of NMN, and divided into PBS group and NMN group. Cell viability was detected at 0, 2, 4, 8, 16 and 32 h, and the effects of NMN on repairing ethanol-induced DNA damage were evaluated by alkaline comet assay. Results: The cell viability was lower in 0.4% ethanol group than than in the control group, and was higher in different concentrations of NMN groups than in 0.4% ethanol group (all P<0.05), with no significant difference in the cells viability between 4 mmol/L and higher concentrations of NMN groups and the control group (all P>0.05). Therefore, 4 mmol/L NMN was selected as a protective agent. The cell tail moments, relative immunofluorescence intensities of γH2AX and relative levels of ROS were higher in 0.4% ethanol group than in the control group, and lower in 4 mmol/L and higher concentrations of NMN groups than in 0.4% ethanol group (all P<0.05). The cell viability was increased and the cell tail moment was shortened with the increase of 4 mmol/L NMN intervention time; and the cell viability in 4 h and more of NMN groups were higher, and the cell tail moment were lower than that in PBS group (all P<0.05). Conclusions NMN attenuates DNA damage in a dose-dependent manner and promotes the repair of DNA damage in a time-dependent manner. NMN has a protective effect on ethanol-induced DNA damage in hepatocytes.

Objective To investigate the current status of preoperative skin preparation in abdominal surgery in China,and put forward suggestions for improvement.Methods From April to May,2016,187 secondary and above hospitals in China were selected,questionnaires were used to investigate the methods for hair removal,skin disinfection on operative field,and application of surgical adhesive drape in abdominal surgery.Results A total of 187 hospitals in 14 provinces were investigated,of which 108 and 79 were tertiary and secondary hospitals respec-tively.87.70% of hospitals performed conventional preoperative hair removal in abdominal surgery,the percentage of conventional depilation in secondary hospitals was higher than tertiary hospitals(93.67% vs 83.33%,χ2 =4.520,P =0.033).85.98% of hospitals selected blade-shaving,7.93% and 23.78% applied chemical depilation and electric depilation respectively.Most hospitals (98.17%)performed skin preparation in the wards,mainly by ward nurses (98.17%),and conducted on the day of surgery (56.10%).86.63%,29.95%,and 3.74% of hospi-tals used iodophor,iodine plus alcohol,and chlorhexidine respectively for disinfecting skin on operative field. 92.51% of hospitals used skin incision/surgical adhesive drape (74.57% used selectively).Conclusion Most hos-pitals in China conventionally perform preoperative hair removal in abdominal surgery,and the primary method for depilation is blade-shaving,nearly half of the hospitals performed depilation on the day of surgery.Iodophor is the major skin antiseptic,surgical adhesive drape is widely used,but it is utilized in limited types of surgery.