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In this study, the persistence of severe acute respiratory syndrome-associated coronavirus (SARS-CoV) was observed in feces, urine and water. In addition, the inactivation of SARS-CoV in wastewater with sodium hypochlorite and chlorine dioxide was also studied. In vitro experiments demonstrated that the virus could only persist for 2 days in hospital wastewater, domestic sewage and dechlorinated tap water, while 3 days in feces, 14 days in PBS and 17 days in urine at 20 degrees C. However, at 4 degrees C, the SARS-CoV could persist for 14 days in wastewater and at least 17 days in feces or urine. SARS-CoV is more susceptible to disinfectants than Escherichia coli and f2 phage. Free chlorine was found to inactivate SARS-CoV better than chlorine dioxide. Free residue chlorine over 0.5 mg/L for chlorine or 2.19 mg/L for chlorine dioxide in wastewater ensures complete inactivation of SARS-CoV while it does not inactivate completely E. coli and f2 phage.
Assuntos
Coronavírus Relacionado à Síndrome Respiratória Aguda Grave/efeitos dos fármacos , Coronavírus Relacionado à Síndrome Respiratória Aguda Grave/fisiologia , Inativação de Vírus , Cloro/farmacologia , Compostos Clorados/farmacologia , Desinfetantes/farmacologia , Escherichia coli/efeitos dos fármacos , Fezes/virologia , Humanos , Levivirus/efeitos dos fármacos , Óxidos/farmacologia , RNA Viral/análise , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Coronavírus Relacionado à Síndrome Respiratória Aguda Grave/genética , Coronavírus Relacionado à Síndrome Respiratória Aguda Grave/isolamento & purificação , Esgotos/virologia , Hipoclorito de Sódio/farmacologia , Urina/virologia , Microbiologia da ÁguaRESUMO
The transmission of severe acute respiratory syndrome-associated coronavirus (SARS-CoV) is associated with close contact to SARS patients and droplet secretions of those patients. The finding of positive RT-PCR results from stools of SARS patients suggests that stools of SARS patients or sewage containing stools of patients could transmit SARS-CoV. We used a novel style of electropositive filter media particle to concentrate the SARS-CoV from the sewage of two hospitals receiving SARS patients in Beijing. We also used cell culture, RT-PCR and gene sequencing to detect and identify the viruses from sewage. No infectious SARS-CoV contamination was found in any of the samples collected, but the nucleic acid of SARS-CoV could be detected in the sewage from the two hospitals before disinfection. While the RNA was only detected in three samples from the 309th Hospital, the others were negative after disinfection. These findings provide strong evidence that SARS-CoV can be excreted through the stool/urine of patients into sewage system, thus making the sewage system a possible route of transmission.
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Hospitais , Síndrome Respiratória Aguda Grave/transmissão , Síndrome Respiratória Aguda Grave/virologia , Coronavírus Relacionado à Síndrome Respiratória Aguda Grave/classificação , Coronavírus Relacionado à Síndrome Respiratória Aguda Grave/isolamento & purificação , Esgotos/virologia , China , Desinfecção/métodos , Fezes/virologia , Filtração/métodos , Humanos , Reação em Cadeia da Polimerase , Coronavírus Relacionado à Síndrome Respiratória Aguda Grave/genética , Sensibilidade e Especificidade , Virologia/métodos , Cultura de VírusRESUMO
AIM: To study whether severe acute respiratory syndrome coronavirus (SARS-CoV) could be excreted from digestive system. METHODS: Cell culture and semi-nested RT-PCR were used to detect SARS-CoV and its RNA from 21 stool and urine samples, and a kind of electropositive filter media particles was used to concentrate the virus in 10 sewage samples from two hospitals receiving SARS patients in Beijing in China. RESULTS: It was demonstrated that there was no live SARS-CoV in all samples collected, but the RNA of SARS-CoV could be detected in seven stool samples from SARS patients with any one of the symptoms of fever, malaise, cough, or dyspnea, in 10 sewage samples before disinfection and 3 samples after disinfection from the two hospitals. The RNA could not be detected in urine and stool samples from patients recovered from SARS. CONCLUSION: Nucleic acid of SARS-CoV can be excreted through the stool of patients into sewage system, and the possibility of SARS-CoV transmitting through digestive system cannot be excluded.
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Sistema Digestório/virologia , Síndrome Respiratória Aguda Grave/transmissão , Síndrome Respiratória Aguda Grave/virologia , Coronavírus Relacionado à Síndrome Respiratória Aguda Grave/isolamento & purificação , Desinfecção , Fezes/virologia , Humanos , Reação em Cadeia da Polimerase/métodos , RNA Viral/isolamento & purificação , Coronavírus Relacionado à Síndrome Respiratória Aguda Grave/genética , Esgotos/virologiaRESUMO
AIM: To develop a rapid detection method of enteroviruses and Hepatitis A virus (HAV). METHODS: A one-step, single-tube consensus primers multiplex RT-PCR was developed to simultaneously detect Poliovirus, Coxsackie virus, Echovirus and HAV. A general upstream primer and a HAV primer and four different sets of primers (5 primers) specific for Poliovirus, Coxsacki evirus, Echovirus and HAV cDNA were mixed in the PCR mixture to reverse transcript and amplify the target DNA. Four distinct amplified DNA segments representing Poliovirus, Coxsackie virus, Echovirus and HAV were identified by gel electrophoresis as 589-,671-, 1084-, and 1128bp sequences, respectively. Semi-nested PCR was used to confirm the amplified products for each enterovirus and HAV. RESULTS: All four kinds of viral genome RNA were detected, and producing four bands which could be differentiated by the band size on the gel. To confirm the specificity of the multiplex PCR products, semi-nested PCR was performed. For all the four strains tested gave positive results. The detection sensitivity of multiplex PCR was similar to that of monoplex RT-PCR which was 24 PFU for Poliovrus,21 PFU for Coxsackie virus,60 PFU for Echovirus and 105 TCID(50) for HAV. The minimum amount of enteric viral RNA detected by semi-nested PCR was equivalent to 2.4 PFU for Poliovrus, 2.1 PFU for Coxsackie virus, 6.0 PFU for Echovirus and 10.5 TCID(50) for HAV. CONCLUSION: The consensus primers multiplex RT-PCR has more advantages over monoplex RT-PCR for enteric viruses detection, namely, the rapid turnaround time and cost effectiveness.
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Enterovirus/isolamento & purificação , Vírus da Hepatite A/isolamento & purificação , Microbiologia da Água , Sequência de Bases , Primers do DNA/genética , Enterovirus/genética , Enterovirus Humano B/genética , Enterovirus Humano B/isolamento & purificação , Vírus da Hepatite A/genética , Humanos , Poliovirus/genética , Poliovirus/isolamento & purificação , RNA Viral/genética , RNA Viral/isolamento & purificação , Reação em Cadeia da Polimerase Via Transcriptase Reversa/estatística & dados numéricos , Sensibilidade e EspecificidadeRESUMO
OBJECTIVE: To develop a rapid and definite diagnostic test of bacterial enteritis caused by pathogenic enterobacteria, the most frequent etiologic agent of infectious enteritis in the world. METHODS: A set of conventional PCR assays were applied to detect and identify salmonella, shigella, and E. coli O157:H7 directly from pure culture and fecal samples. The general primers of pathogenic enterobacteria were located on the uidA gene, which were found not only in E. coli nuclear acid, but also in shigella and salmonella genes. Shigella primer was from ipaH gene whose coded invasive plasmid relative antigen existed both in plasmid and in genome. The primers of salmonella were designed from the 16SrRNA sequence. The primer of E. coli O157:H7 was taken from eaeA gene. Five random primers were selected for RAPD. The detection system included common PCR, semi-nested PCR and RAPD. RESULTS: This method was more sensitive, specific and efficient and its processing was rapid and simple. For example, the method could be used to specifically detect and identify salmonella, shigella, and E. coli O157:H7, and its sensitivity ranged from 3 to 50 CFU, and its detection time was 4 hours. CONCLUSION: This PCR method, therefore, can serve as a routine and practical protocol for detecting and identifying pathogenic microorganisms from clinical samples.
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DNA Bacteriano/análise , Escherichia coli O157/isolamento & purificação , Salmonella typhi/isolamento & purificação , Shigella flexneri/isolamento & purificação , Primers do DNA , Fezes/microbiologia , Humanos , Reação em Cadeia da Polimerase , Sensibilidade e EspecificidadeRESUMO
OBJECTIVE: In order to explore the existence of SARS coronavirus (Co-V) and/or its RNA in sewage of hospitals administered SARS patients. METHODS: A novel electropositive filter was used to concentrate the SARS-CoV from the sewage of two hospitals administered SARS patients in Beijing, including twelve 2,500 ml sewage samples from the hospitals before disinfection, and ten 25,000 ml samples after disinfection; as well as cell culture, RT-PCR and sequencing of gene to detect and identify the viruses from sewage. RESULTS: There was no live SARS-CoV detected in the sewage in this study. The nucleic acid of SARS-CoV had been found in the 12 sewage samples before disinfection from both hospitals by semi-nested PCR. After disinfection, SARS-CoV RNA could only be detected from the samples from the 309th Hospital, and the others were negative. CONCLUSION: It provides evidence that there is no live SARS-Cov in the sewage from hospitals with SARS patients though SARS-CoV RNA can be detected.
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RNA Viral/análise , Coronavírus Relacionado à Síndrome Respiratória Aguda Grave/isolamento & purificação , Esgotos/virologia , Hospitais , Humanos , Nucleocapsídeo/análise , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Coronavírus Relacionado à Síndrome Respiratória Aguda Grave/genética , Síndrome Respiratória Aguda Grave/virologiaRESUMO
Objective To discuss the application of flipped classroom teaching model in the teaching reform of Science of Tuina Technique based on MOOC; To provide references for promoting teaching quality of Science of Tuina Technique. Methods Flipped classroom teaching model based on MOOC and traditional teaching model were conducted in 2 classes of 2013 in Guangxi University of Chinese Medicine, one experimental groups and one control group. After the end of the course, theoretical knowledge and techniques skill scores of the two classes were compared. Questionnaire was given to students in the experimental class to understand their satisfaction towards flipped classroom based on MOOC. Results The scores of theoretical knowledge, performance demonstration test results, mannequin test and practices mechanics test of experimental group were high than the control group, with statistical significance (P<0.05). The results of questionnaire showed that the satisfaction of students in the experimental group towards flipped classroom based on MOOC was 95. Conclusion Flipped classroom teaching model based on MOOC applied to the teaching of Science of Tuina Technique can improve the students' learning interest and initiative, and then improve academic performance.
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As the researches of electric impedance tomography (EIT) applications in medical examinations deepen, we attempt to produce the visualization of 3D images of human bladder. In this paper, a planar electrode array system will be introduced as the measuring platform and a series of feasible methods are proposed to evaluate the simulated volume of bladder to avoid overfilling. The combined regularization algorithm enhances the spatial resolution and presents distinguishable sketch of disturbances from the background, which provides us with reliable data from inverse problem to carry on to the three-dimensional reconstruction. By detecting the edge elements and tracking down the lost information, we extract quantitative morphological features of the object from the noises and background. Preliminary measurements were conducted and the results showed that the proposed algorithm overcomes the defects of holes, protrusions, and debris in reconstruction. In addition, the targets' location in space and roughly volume could be calculated according to the grid of finite element of the model, and this feature was never achievable for the previous 2D imaging.
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Impedância Elétrica , Imageamento Tridimensional/métodos , Tomografia/métodos , Bexiga Urinária/patologia , Bexiga Urinária/fisiologia , Algoritmos , Biologia Computacional/métodos , Eletrodos , Análise de Elementos Finitos , Humanos , Processamento de Imagem Assistida por Computador/métodos , Informática Médica/métodos , Modelos Teóricos , Pletismografia de Impedância/métodosRESUMO
Objective To numerically simulate the propagation of pulse wave in human arterial tree by proposing a novel calculation method which combines a transmission line model and a recursive algorithm of input impedance, and to study the effects of individual differences and arterial tree parameters on pulse wave so as to provide references for the analysis on physiologic and pathologic characteristics of human arterial tree. MethodsThe transmission line model of human arterial tree was constructed, which consisted of 55-segment large and medium sized arteries. The recursive algorithm was applied to compute the input impedance of arterial tree at each point. The blood pressures and flows of 55 arteries were calculated and showed in the distribution graphs. Based on this method, the effects of height, heart rate, stroke volume, internal radius and wall thickness on pulse wave propagation and blood pressure distribution were compared. Results The simulation results were in good agreement with the general rules of pulse wave propagation. The propagation of pulse wave in arterial tree showed significantly different characteristics for different parameters. Conclusions The proposed method can effectively simulate the propagation of pulse wave in arterial tree and accurately reflect the effects of individual differences and hemodynamics parameters on pulse wave propagation, and it is an important assistant means for the pathophysiologic analysis and diagnosis of human arterial tree.
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Objective In order to provide a reference for analysis of the pathophysiological changes of human arterial tree, the effects of the arterial parameters on input impedance of arterial tree were studied by proposing a recursive algorithm to calculate the input impedance. Method A distributed electric network model was constructed for the arterial tree which consisted of 55 segments accounting for all the central vessels and major peripheral arteries. By setting up the peripheral resistance of the model and constructing a unilateral data link list of the arterial tree, the recursive algorithm was employed to compute the input impedance of ascending aorta in the arterial tree. Then, comparisons of the effects of arterial compliance, peripheral resistance, length, internal radius and wall thickness on the input impedance were made based on the recursive algorithm. Results The computational results were in accord with experimental data and results of other models, and proved the validity of the model and algorithm. The input impedances of the arterial tree showed significant influence with different characteristics for different parameters. Conclusions The input impedance of arterial tree can reflect the changes of the hemodynamic parameters effectively, which is an important reference for the pathophysiological diagnosis of human arterial tree.
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AIM: To explore the protective effect of L-arginine on isolated rat heart with ischemia/reperfusion injury. METHODS: 24 wistar rats were randomly divided into 3 groups (each 8): control group, ischemia group, L-arginine group. The myocardiac relatively ischemia/reperfusion models in vitro were set up by using weak current stimulating isolated rat hearts. During the pre-ischemia, post-ischemia 15 min and post-ischemia 30 min, the coronary fluid was collected for testing contents of MDA and activities of both CK and LDH. Cardiac functional indexes were recorded through Pclab. At the time of 5 min, 10 min, 20 min, 30 min after ischemia, the recovery of PRP, + DP/dt(max) and - DP/dt(max) were calculated. RESULTS: (1) During the reperfusion, L-arginine group achieved better recovery of cardiac function than that of the ischemia group. (2) MDA content, CK and LDH activities both in the coronary fluid and in the myocardium of L-arginine group were lower than those of the ischemia group, while SOD activities in the myocardium of L-arginine group were higher than that of the ischemia group. CONCLUSION: To some extent, L-arginine could protect the myocardium from ischemia/reperfusion injury.
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Arginina/farmacologia , Coração/efeitos dos fármacos , Traumatismo por Reperfusão Miocárdica/prevenção & controle , Miocárdio/metabolismo , Animais , Masculino , Ratos , Ratos WistarRESUMO
Combining the experiment teaching innovation in our college,we carried on beneficial quest to the teaching mode of the biochemistry experiment.During the practice of the designing experiment,we not only pay attention to cultivating students' creation ability,but also lay emphasis on cultivation of their autonomy ability.which is very important to improve the students,early scientific research abilities or clinical practice abilities and so on.