This article reviewed the researches proceeding on the contamination and detection of the foodborne pathogen noroviruses (NoVs) in fresh produce, which involved the NoVs contaminations in fresh produce, the special attachment of NoVs in fresh produce, the NoVs outbreaks associated with fresh produce and the NoVs detection in fresh produce. There had been an increase in reported infectious disease risks associated with the consumptions of fresh produce for recent 30 years. Because the NoVs, as a primary cause of viral gastroenteritis thoughout the world, were highly contagious, had a low infectious dose, and were persistent in the environment. And also the methods for NoVs detection in food had significantly developed over the last 15 years. Currently NoVs were the most common pathogen accounting for 40% of outbreaks associated with fresh produce (i. e., fruits and vegetables). Data from outbreaks investigations verified fresh produce as the high risk food products for NoVs. The fresh produce were typically eaten raw with no thermal processing, can be contaminated at any step during production and processing from faecally polluted water and fertilizers, the poor hygiene practices by food handlers and the cross-contamination. The attachment of NoVs to the fresh produce was due to the physio-chemical factors of virus protein coat, the special attachment to different fresh produce, and the possibility for internalization of NoVs. It might provide answers to why those high risk foods were more frequently implicated (i. e., lettuce and raspberries). According to the data of foodborne NoVs outbreaks which were associated with fresh produce from EU countries and the USA, the outbreaks in EU countries were mainly associated with NoVs contaminated raspberries and lettuce, while in USA which were associated with NoVs contaminated lettuce. Unfortunately, there were no NoVs detection methods for fresh produce or the data of foodborne NoVs outbreaks which were associated with fresh produce in China. That made it difficult to analyze the NoVs contamination situation in China. The heterogeneous distributions of presumably low levels of virus, which presented in contaminated fresh produce, also made it difficult to detect NoVs. To solve this problem, different sampling methods, viral elution methods and RT-qPCR methods were chosen. For example, according to the isoelectric point of NoVs particles, high pH and high ionic strength solution could be used as means for releasing NoVs. For the elution from acidic fruit, the buffer capacity and the virus recovery could be increased by the addition of tris-HCl. When analyzing pectin containing raspberries or strawberries, the viral elution usually incubated with pectinase at neutral pH to avoid from foaming jelly. In this paper, the latest ISO standard for NoV detection in food and the new approaches for NoV detection were also reviewed to provide references for domestic researches. It was necessary to establish and develop domestic methods for NoV detection in fresh produce, especially the different NoV conventional molecular detection methods with corresponding NoV extraction methods, which targeted to the different adsorption characteristics of different fruits and vegetables, in order to strengthen the national food safety monitoring.
Food Analysis ; methods ; Food Contamination ; analysis ; Foodborne Diseases ; virology ; Fruit ; virology ; Gastroenteritis ; virology ; Humans ; Norovirus ; classification ; genetics ; isolation & purification ; physiology ; Vegetables ; virology

Objective To explore the test-retest reliability of the computerized dynamometer to measure the grip strength in the healthy subjects and cervical radiculopathy patients, and investigate their characteristics. Methods The grip strength of 20 healthy subjects and 26 radiculopathy patients were measured with dynamometer, including the maximal voluntary grip strength at 5 width twice and the 10 s sustained isometric grip at the second width (45 mm) of the dynamometer once. Results The Intra-class correlation coefficient (ICC) was 0.947～0.989 in healthy subjects, and 0.903～0.960 in cervical radiculopathy patients. The maximal voluntary grip strength of healthy subjects was significantly stronger than that of the radiculopathy patients (P<0.05). The decrease rate of grip strength in non-dominant side, if affected, in the cervical radiculopathy patients was significantly slower than that of the healthy subject's non-dominant side (P<0.05). Conclusion The computerized dynamometer is a reliable tool to evaluate the grip strength in both healthy subjects and cervical radiculopathy patients. The grip strength of healthy subject's is stronger than of the radiculopathy patients. The endurance of grip is better in the radiculopathy patient's non-dominant side if affected.

Objective To explore the correlation of CT perfusion imaging with microvessel density (MVD) and vascular endothelial growth factor (VEGF) in hepatic alveolar echinococcosis (HAE).Methods Multi-slice spiral CT perfusion imaging was performed in 27 patients with HAE.Time-density curves(TDC) of the HAE peripheral area was drawn from the region of interest (ROI) with perfusion functional software.CT perfusion parameters including blood flow ( BF ),blood volume ( BV ),mean transit time(MTT) and permeability surface area product (PS) were calculated.MVD and VEGF expression of pathological specimens were examined by immunohistochemical staining with anti-CD34,anti-VEGF monoclonal antibody.The CT perfusion parameters,MVD and VEGF were compared in different types of TDC with t test.The correlation of CT perfusion parameters with MVD and VEGF were analyzed with Spearman test.Results In this group,21 cases which TDC lower than that of the liver were classified as type Ⅰ,the others 6 cases TDC higher than the liver were of type Ⅱ TDC.TDC perfusion parameters of the two types were as follows,BF:( 111.7 + 27.6),( 158.9 + 39.5 ) ml · 100 g- 1 · min - 1,BV:( 15.1 + 6.2),(26.8+8.4) ml/100 g,MTT:(7.0+4.4),(7.7+3.1) s,PS:(51.7 +17.3),(51.0+20.5) ml·100 g-1 · min-1.The significant differences of BF,BV and MVD[ (20.5 +5.4)/HP,(37.2 ±7.5)/HP,respectively ] were found between two types ( t =- 7.897,- 18.783,- 5.223,P ＜ 0.05,respectively).There were no significant differences in MTT,PS and VEGF expression(2.1 ± 1.0,3.2 ± 1.0,respectively)between two types of TDC(P ＞0.05).The correlation was found between the MVD and BF and BV in the type Ⅱ TDC group( r =0.789 and 0.878,respectively) and no correlation was found between MVD and each CT perfusion parameters in the type Ⅰ TDC group ( P ＞ 0.05 ).There was no correlation between the VEGF expression and CT perfusion parameters in two types of TDC ( P ＞ 0.05 ).Conclusion CT perfusion imaging with different type of TDC reflected different situation of angiogenesis in HAE peripheral area,which could be a potential technique to illustrate the microcirculation of this disease.

Twenty five children with recurrent wheezing,intractable cough and recurrent respiratory infection were examined and treated by electron-bronchoscopy.Among them 9 cases were diagnosed as tracheobronchomalacia.simple endobronchial inflammation was found in 7 cases,foreign body in bronchus were found in 6 cases,bronchostenosis in 2 cases and pulmonary hemorrhage in 1 case.Tracheobronehomalacia is one of the leading causes of recurrent wheezing and intractable cough in children.Electron-bronchoscopie examination is important in diagnosis of tracheobronchomalacia in children.

Objective To observe the effects of intervention of soothing liver and activating blood Chinese medicine on cardiac function and myocardial pathologic morphology of BMSCs transplanting on myocardial IRI of rats, and investigate its myocardial protection mechanism. Methods Model of myocardial IRI was established by coronary artery ligation in rats. SD rats were randomly divided into sham operation group, IRI group, BMSCs group and combined group. Rats in combined group were filled the stomach with soothing liver and activating blood Chinese medicine, and rats in other groups were filled the stomach with the same dose of normal saline. After 4 weeks, myocardial pathologic morphology was observed with light microscope. Cardiac function was detected with ultrasonic cardiogram.Results Compared with BMSCs group, heart function of the combined group improved, with significant statistical difference (P<0.05,P<0.01). Pathological observation showed that myocardial structure and pathological morphology were obviously promoted in the combined group.Conclusion Soothing liver and activating blood Chinese medicine could improve heart function and myocardial pathological morphology of IRI rats with BMSCs transplantation.

Objective To investigate the application value of functional magnetic resonance imaging nethods diffusion weighted imagingand dynamic contrast-enhanced magnetic resonance imaging in theT stagingof rectal cancer.Methods Through the retrospectively analysis of DWI and DCE-MRI images of 78 rectal cancer patients confirmed by pathology,the different of routine sequence examination and functional magnetic resonance imaging combined with routine sequence examination in T thestaging diagnosis were contrasted analysis.The correlation of ADC value and quantitative parameters of Ktrans,Kep and Ve values with tumor T staging was analyzed.Results The functional magnetic resonance imaging combined with routine sequence examination in T staging screened 68 cases successfully,and the accuracy rate was 87.2％.preoperative T staging and postoperative pathology of rectal cancerwas better thanroutine sequence examinationin T staging (59 cases,with the accuracy rate 75.6％) (Kappavalue:0.81 vs 0.65,P ＜ 0.05).The ADCvalue andDCE-MRI quantitative parameters values of K and Ve increased with the increase of tumor T staging (P ＜ 0.05).There was no statistically significant difference of Kep values.Conclusions The ADC value and DCE-MRI quantitative parameters (K and Ve values) had certain relevance with Tstaging of rectal cancer.The functional magnetic resonance imaging had a high accuracy in the preoperative T staging of rectal cancer,which proves certain clinical value in judging invasion depth of tumor in the rectal wall.

OBJECTIVE:To establish the HPLC fingerprint of Zhibai dihuang pills(concentrated pills),and to evaluate its quality. METHODS:The determination was performed on Dikma Diamonsil C18column with mobile phase consisted of 0.1%acetic acid solution-methanol(gradient elution)at the flow rate of 1.0 mL/min. The detection wavelength was set at 260 nm,and column temperature was 30 ℃. The sample size was 10 μL. Using paeonol as reference,HPLC chromatograms of samples from A, B,C manufacturers within validity period and samples from manufacturer A within validity period and out of validity period were drawn. The similarity of HPLC chromatogram for samples from A,B and C manufacturers and samples from A manufacturer within validity period and out of validity period was evaluated by TCM Chromatogram Fingerprint Similarity Evaluation System (2004 A). Common peaks of HPLC chromatogram for 3 manufacturers sample within validity period were confirmed. RESULTS:There were 24,29 and 32 common peaks in HPLC chromatograms for each 10 batches of samples from manufacturer A,B and C within validity period,respectively. The similarity of corresponding HPLC chromatograms of samples from manufacturer A,B and C compared with control HPLC chromatography were all higher than 0.94 with good agreement. HPLC chromatograms of sample from A manufacturer within validity period had good agreement with that from A manufacturer out of validity period. CONCLUSIONS:Established HPLC fingerprint analysis method can represent the quality of Zhibai dihuang pills (concentrated pills),but cannot effectively identify the expired samples.

Objective To evaluate the safety and efficacy of the combined treatment with an optimized intense pulsed light (IPL) and a non-ablative fractional laser (NAFL) for facial rejuvenation.Methods A prospective,split-face,randomized,controlled study was conducted.A total of 22 testees with facial photoaging,who aged from 35 to 55 years,were enrolled into this study from the Department of Dermatology of Peking University First Hospital between March and June in 2017.By a random number table,the two sides of each testee's face were randomized to receive combined treatment with optimized IPL immediately followed by non-ablative 1 565 nm Erbium:Glass fractional laser (combined treatment group) or non-ablative 1 565 nm Erbium:Glass fractional laser alone (NAFL group) once every month for 3 sessions.Before the treatment,60 and 90 days after the treatment (1 month after the second and third treatment respectively),photos of the treatment regions were taken,skin physiology parameters (including skin melanin,erythema indices,water content of the stratum corneum,transepidermal water loss [TEWL],skin flexibility and glossiness) were measured,and subjective and objective clinical evaluation was carried out.After each treatment,adverse reactions were assessed by two dermatologists independently,including facial erythema,swelling and crusting,desquamation,pigmentation and pains.Results During the treatment course,1 testee dropped out due to pains,another 1 testee dropped out for personal reasons,and 20 testees completed the treatment and follow-up.The combined treatment group showed significantly decreased melanin indices on days 60 and 90 (152.9 ± 36.9 and 155.0 ± 38.1,respectively) compared with that before the treatment (168.4 ± 41.3,F =5.321,P ＜ 0.05).On day 60,the melanin index was significantly lower in the combined treatment group than in the NAFL group (159.4 ± 35.3,P ＜ 0.05).However,the melanin indices on days 60 and 90 in the NAFL group (159.4 ± 35.3,156.7 ± 36.3) did not significantly differ from that before the treatment (165.9 ± 35.4,P ＞ 0.05).No significant difference was observed between the pre-and post-treatment erythema indices in either of the two groups (both P ＞ 0.05).The water content of the stratum corneum on days 60 and 90 significantly increased compared with that before the treatment in both the combined treatment group (F =21.795,P ＜ 0.001) and NAFL group (F =21.798,P ＜ 0.001),while the TEWL on days 60 and 90 significantly decreased compared with that before the treatment in both the combined treatment group (F =8.848,P =0.001) and NAFL group (F =5.833,P ＜ 0.05).However,there were no significant differences in either of the water content of the stratum corneum or TEWL on days 60 and 90 between the two groups (P ＞ 0.05).On days 60 and 90,the combined treatment group and NAFL group both showed significantly increased skin flexibility (P＜ 0.05,0.001,respectively) and glossiness (both P ＜ 0.001) compared with those before the treatment.On day 90,the skin glossiness in the combined treatment group was higher than that in the NAFL group (P ＜ 0.05).The short-term adverse reactions included transient pain,erythema and swelling which lasted 2-3 days,and slight desquamation.The main adverse reaction was mild local pigmentation,which lasted 2-3 months and then subsided gradually.Conclusion The 3 sessions of treatment with an optimized IPL immediately followed by a 1 565 nm NAFL is clinically superior to those with the NAFL alone for improving the facial pigmentation and skin glossiness,and the adverse reactions are usually transient and mild.

Objective To explore and analyze the application effect of scenario simulation combined with PBL in the clinical teaching of intracranial aneurysm disease. Methods Totally 60 student nurses in Xijing Hospital were selected and divided into the observation group and the control group according to random number table method, with 30 student nurses in each group. Student nurses in the observation group were given scenario simulation combined with PBL method, while student nurses in the control group given traditional nursing teaching method. At the end of their intership, the scores of theory and practice of student nurses in two groups were compared, and their evaluations of teaching effect were collected. Results After teaching, the theoretical score of student nurses in the observation group was (89.2±4.39), and the practical score was (85.9±2.50), they were all higher than the scores in the control group ( t=4.114,5.092;P<0.05) . The score of evaluation in the observation group was also higher than that in the control group ( P<0. 05 ) . Conclusions The use of scenario simulation and PBL is helpful in improving the learning effect student nurses in the clinical teaching of intracranial aneurysm disease and enhancing the clinical practice ability, and it is worth of popularization.