Testing-culling is one of the important prevention and control measures considered in the study of animal infectious diseases.However,the process of finding infected animals(animal testing)is still not well studied th...Testing-culling is one of the important prevention and control measures considered in the study of animal infectious diseases.However,the process of finding infected animals(animal testing)is still not well studied through the kinetic model.In this paper,based on the characteristics of animal testing,a time-delayed model on brucellosis transmission is established.U nder the general hy pothesis of biological significance,the existence and stability of equilibria are first investigated.The results find that the global stability of equilibria depends on the basic reproduction number Ro without the information delay:if Ro S 1,the disease dies out;if Ro>1,the endemic equilibriurn exists and the disease persists.Next,the impact of information delay on the dynamics of the model is analyzed and Hopf bifurcation is found in the established model when the information delay is greater than a critical value.Finally,the thcoretical results are then further explained through numerical analysis and the significance of these results for the development of risk management measures is elaborated.展开更多
Background Many patients have symptoms suggestive of coronary artery disease （CAD） and are often eval- uated with the use of diagnostic testing, although there are limited data from randomized trials to guide care.
There is currently no treatment for effectively slowing the progression of Alzheimer＇s disease, so early prevention is very important. Numerous studies have shown that flavonoids can improve memory impairment. The pr...There is currently no treatment for effectively slowing the progression of Alzheimer＇s disease, so early prevention is very important. Numerous studies have shown that flavonoids can improve memory impairment. The present study investigated the effects of myricetin, a member of the flavonoids, on intracerebroventricular streptozotocin induced neuronal loss and memory impairment in rat models of Alzheimer＇s disease. Myricetin at 5 or 10 mg/kg was intraperitoneally injected into rats over 21 days. Control rats were treated with 10 m L/kg saline. Behavioral test（the shuttle box test） was performed on day 22 to examine learning and memory in rats. Immediately after that, hematoxylin-eosin staining was performed to observe the morphological change in hippocampal CA3 pyramidal neurons. Myricetin greatly increased the number of hippocampal CA3 pyramidal neurons and improved learning and memory impairments in rats with Alzheimer＇s disease. These findings suggest that myricetin is beneficial for treatment of Alzheimer＇s disease.展开更多
Objectives This study sought to evaluate the diagnostic value of abnormal increase of postexercise systolic blood pressure (SBP) for detecting coronary artery disease (CAD) in patients with or without hypertension. Me...Objectives This study sought to evaluate the diagnostic value of abnormal increase of postexercise systolic blood pressure (SBP) for detecting coronary artery disease (CAD) in patients with or without hypertension. Methods Treadmill exercise testing (TET) was conducted in 88 patients (40 CAD patients, 48 control subjects) with or without hypertension, each of whom underwent selective coronary angiography (CAG). The abnormal increase of postexercise SBP was defined as 10mmHg higher than earlier periods during the recovery phase (6 minutes) of exercise testing. Results The abnormal increase of postexercise SBP had higher sensitivity, specificity, and accuracy for detecting CAD than those of ST - segment depression in patients with or without hypertension. Its accuracy increased with the severity of CAD while decreased in patients with hypertension, and the increase value of SBP had a positive correlation with the extent of coronary artery lesion. The combination of ST - segment depression and abnormal increase of postexercise SBP diagnosed CAD most accurately in patients with hypertension. Conclusions Abnormal increase of postexercise SBP may be a useful index for diagnosing CAD.展开更多
The United Nations Secretary-General Mechanism(UNSGM)for investigation of the alleged use of chemical and biological weapons is the only established international mechanism of this type under the UN.The UNGSM may laun...The United Nations Secretary-General Mechanism(UNSGM)for investigation of the alleged use of chemical and biological weapons is the only established international mechanism of this type under the UN.The UNGSM may launch an international investigation,relying on a roster of expert consultants,qualified experts,and analytical laboratories nominated by the member states.Under the framework of the UNSGM,we organized an external quality assurance exercise for nominated laboratories,named the Disease X Test,to improve the ability to discover and identify new pathogens that may cause possible epidemics and to determine their animal origin.The“what-if”scenario was to identify the etiological agent responsible for an outbreak that has tested negative for many known pathogens,including viruses and bacteria.Three microbes were added to the samples,Dabie bandavirus,Mammarenavirus,and Gemella spp.,of which the last two have not been taxonomically named or published.The animal samples were from Rattus norvegicus,Marmota himalayana,New Zealand white rabbit,and the tick Haemaphysalis longicornis.Of the 11 international laboratories that participated in this activity,six accurately identified pathogen X as a new Mammarenavirus,and five correctly identified the animal origin as R.norvegicus.These results showed that many laboratories under the UNSGM have the capacity and ability to identify a new virus during a possible international investigation of a suspected biological event.The technical details are discussed in this report.展开更多
Liver disease accounts for approximately 2 million deaths per year worldwide.All chronic liver diseases(CLDs),whether of toxic,genetic,autoimmune,or infectious origin,undergo typical histological changes in the struct...Liver disease accounts for approximately 2 million deaths per year worldwide.All chronic liver diseases(CLDs),whether of toxic,genetic,autoimmune,or infectious origin,undergo typical histological changes in the structure of the tissue.These changes may include the accumulation of extracellular matrix material,fats,triglycerides,or tissue scarring.Noninvasive methods for diagnosing CLD,such as conventional B-mode ultrasound(US),play a significant role in diagnosis.Doppler US,when coupled with B-mode US,can be helpful in evaluating the hemodynamics of hepatic vessels and detecting US findings associated with hepatic decompensation.US elastography can assess liver stiffness,serving as a surrogate marker for liver fibrosis.It is important to note that interpreting these values should not rely solely on a histological classification.Contrast-enhanced US(CEUS)provides valuable information on tissue perfusion and enables excellent differentiation between benign and malignant focal liver lesions.Clinical evaluation,the etiology of liver disease,and the patient current comorbidities all influence the interpretation of liver stiffness measurements.These measurements are most clinically relevant when interpreted as a probability of compensated advanced CLD.B-mode US offers a subjective estimation of fatty infiltration and has limited sensitivity for mild steatosis.The controlled attenuation parameter requires a dedicated device,and cutoff values are not clearly defined.Quan-titative US parameters for liver fat estimation include the attenuation coefficient,backscatter coefficient,and speed of sound.These parameters offer the advantage of providing fat quantification alongside B-mode evaluation and other US parameters.Multiparametric US(MPUS)of the liver introduces a new concept for complete noninvasive diagnosis.It encourages examiners to utilize the latest features of an US machine,including conventional B-mode,liver stiffness evaluation,fat quantification,dispersion imaging,Doppler US,and CEUS for focal liver lesion characterization.This comprehensive approach allows for diagnosis in a single examination,providing clinicians worldwide with a broader perspective and becoming a cornerstone in their diagnostic arsenal.MPUS,in the hands of skilled clinicians,becomes an invaluable predictive tool for diagnosing,staging,and monitoring CLD.展开更多
Background The Global Initiative for Chronic Obstructive Lung Disease （GOLD） presented a new ABCD group classification of chronic obstructive pulmonary disease （COPD）.We aimed to examine the association of spirome...Background The Global Initiative for Chronic Obstructive Lung Disease （GOLD） presented a new ABCD group classification of chronic obstructive pulmonary disease （COPD）.We aimed to examine the association of spirometric classification and the new GOLD classification with exacerbations,and to compare symptoms in different ways.Methods We investigated 848 patients with stable COPD from 24 hospitals.The annual frequencies of acute exacerbation and hospitalization were compared between the old and new classification.The symptom level was assessed using COPD assessment test （CAT） and modified British Medical Research Council （mMRC） questionnaire.Results A total of 848 patients were included in this study.According to spirometric classification,there were 32 patients of grade Ⅰ （3.8％）,315 of grade Ⅱ （37.1％）,366 of grade Ⅲ （43.2％）,and 135 of grade Ⅳ （15.9％）.According to GOLD 2011 classification,there were 59 patients of group A （7.0％）,172 of group B （20.3％）,55 of group C （6.5％）,and 562 of group D （66.3％）.In spirometric classification,the annual frequencies of acute exacerbation and associated hospitalization were respectively 1 （0-3） and 0 （0-2） for grade Ⅰ; 1 （0-5） and 0 （0-2） for grade Ⅱ; 2 （0-6） and 1 （0-3） for grade Ⅲ,and 3 （0-6） and 2 （0-3） for grade Ⅳ.In GOLD 2011,respectively 0 （0-3） and 0 （0-1） （group A）,1 （0-4） and 0 （0-3） （group B）,1 （0-5） and 0 （0-3） （group C）,and 3 （0-6） and 1 （0-3） （group D）.There were no significant difference between group B and C （Z=-1.347,P=0.178; Z=-0.772,P=0.440,respectively）.The coincidence rate using mMRC=1 and CAT=10 as cutoff points was 86.6％ （734/848,x=0.706）,compared with 77.9％ （661/848,K=0.60） using mMRC=2 and CAT=10.Conclusions Lung function test may be a better predictor of acute exacerbation and associated hospitalization of COPD.It is more appropriate to use mMRC=1 as cutoff point for assessing COPD symptoms.展开更多
基金This research is partially supported by the Natiopal Youth Science Foundation ofChina (11501528)the National Science Foundation of China (11571324)theFund for Shanxi“1331KIRT”.
文摘Testing-culling is one of the important prevention and control measures considered in the study of animal infectious diseases.However,the process of finding infected animals(animal testing)is still not well studied through the kinetic model.In this paper,based on the characteristics of animal testing,a time-delayed model on brucellosis transmission is established.U nder the general hy pothesis of biological significance,the existence and stability of equilibria are first investigated.The results find that the global stability of equilibria depends on the basic reproduction number Ro without the information delay:if Ro S 1,the disease dies out;if Ro>1,the endemic equilibriurn exists and the disease persists.Next,the impact of information delay on the dynamics of the model is analyzed and Hopf bifurcation is found in the established model when the information delay is greater than a critical value.Finally,the thcoretical results are then further explained through numerical analysis and the significance of these results for the development of risk management measures is elaborated.
基金Funded by the National Heart,Lung,and Blood InstitutePROMISE Clinical Trials.gov number,NCT01174550
文摘Background Many patients have symptoms suggestive of coronary artery disease （CAD） and are often eval- uated with the use of diagnostic testing, although there are limited data from randomized trials to guide care.
基金funded by the Department of Biology,Faculty of Science,Arak University,Iran,No.38156-8-8349
文摘There is currently no treatment for effectively slowing the progression of Alzheimer＇s disease, so early prevention is very important. Numerous studies have shown that flavonoids can improve memory impairment. The present study investigated the effects of myricetin, a member of the flavonoids, on intracerebroventricular streptozotocin induced neuronal loss and memory impairment in rat models of Alzheimer＇s disease. Myricetin at 5 or 10 mg/kg was intraperitoneally injected into rats over 21 days. Control rats were treated with 10 m L/kg saline. Behavioral test（the shuttle box test） was performed on day 22 to examine learning and memory in rats. Immediately after that, hematoxylin-eosin staining was performed to observe the morphological change in hippocampal CA3 pyramidal neurons. Myricetin greatly increased the number of hippocampal CA3 pyramidal neurons and improved learning and memory impairments in rats with Alzheimer＇s disease. These findings suggest that myricetin is beneficial for treatment of Alzheimer＇s disease.
文摘Objectives This study sought to evaluate the diagnostic value of abnormal increase of postexercise systolic blood pressure (SBP) for detecting coronary artery disease (CAD) in patients with or without hypertension. Methods Treadmill exercise testing (TET) was conducted in 88 patients (40 CAD patients, 48 control subjects) with or without hypertension, each of whom underwent selective coronary angiography (CAG). The abnormal increase of postexercise SBP was defined as 10mmHg higher than earlier periods during the recovery phase (6 minutes) of exercise testing. Results The abnormal increase of postexercise SBP had higher sensitivity, specificity, and accuracy for detecting CAD than those of ST - segment depression in patients with or without hypertension. Its accuracy increased with the severity of CAD while decreased in patients with hypertension, and the increase value of SBP had a positive correlation with the extent of coronary artery lesion. The combination of ST - segment depression and abnormal increase of postexercise SBP diagnosed CAD most accurately in patients with hypertension. Conclusions Abnormal increase of postexercise SBP may be a useful index for diagnosing CAD.
文摘The United Nations Secretary-General Mechanism(UNSGM)for investigation of the alleged use of chemical and biological weapons is the only established international mechanism of this type under the UN.The UNGSM may launch an international investigation,relying on a roster of expert consultants,qualified experts,and analytical laboratories nominated by the member states.Under the framework of the UNSGM,we organized an external quality assurance exercise for nominated laboratories,named the Disease X Test,to improve the ability to discover and identify new pathogens that may cause possible epidemics and to determine their animal origin.The“what-if”scenario was to identify the etiological agent responsible for an outbreak that has tested negative for many known pathogens,including viruses and bacteria.Three microbes were added to the samples,Dabie bandavirus,Mammarenavirus,and Gemella spp.,of which the last two have not been taxonomically named or published.The animal samples were from Rattus norvegicus,Marmota himalayana,New Zealand white rabbit,and the tick Haemaphysalis longicornis.Of the 11 international laboratories that participated in this activity,six accurately identified pathogen X as a new Mammarenavirus,and five correctly identified the animal origin as R.norvegicus.These results showed that many laboratories under the UNSGM have the capacity and ability to identify a new virus during a possible international investigation of a suspected biological event.The technical details are discussed in this report.
文摘Liver disease accounts for approximately 2 million deaths per year worldwide.All chronic liver diseases(CLDs),whether of toxic,genetic,autoimmune,or infectious origin,undergo typical histological changes in the structure of the tissue.These changes may include the accumulation of extracellular matrix material,fats,triglycerides,or tissue scarring.Noninvasive methods for diagnosing CLD,such as conventional B-mode ultrasound(US),play a significant role in diagnosis.Doppler US,when coupled with B-mode US,can be helpful in evaluating the hemodynamics of hepatic vessels and detecting US findings associated with hepatic decompensation.US elastography can assess liver stiffness,serving as a surrogate marker for liver fibrosis.It is important to note that interpreting these values should not rely solely on a histological classification.Contrast-enhanced US(CEUS)provides valuable information on tissue perfusion and enables excellent differentiation between benign and malignant focal liver lesions.Clinical evaluation,the etiology of liver disease,and the patient current comorbidities all influence the interpretation of liver stiffness measurements.These measurements are most clinically relevant when interpreted as a probability of compensated advanced CLD.B-mode US offers a subjective estimation of fatty infiltration and has limited sensitivity for mild steatosis.The controlled attenuation parameter requires a dedicated device,and cutoff values are not clearly defined.Quan-titative US parameters for liver fat estimation include the attenuation coefficient,backscatter coefficient,and speed of sound.These parameters offer the advantage of providing fat quantification alongside B-mode evaluation and other US parameters.Multiparametric US(MPUS)of the liver introduces a new concept for complete noninvasive diagnosis.It encourages examiners to utilize the latest features of an US machine,including conventional B-mode,liver stiffness evaluation,fat quantification,dispersion imaging,Doppler US,and CEUS for focal liver lesion characterization.This comprehensive approach allows for diagnosis in a single examination,providing clinicians worldwide with a broader perspective and becoming a cornerstone in their diagnostic arsenal.MPUS,in the hands of skilled clinicians,becomes an invaluable predictive tool for diagnosing,staging,and monitoring CLD.
文摘Background The Global Initiative for Chronic Obstructive Lung Disease （GOLD） presented a new ABCD group classification of chronic obstructive pulmonary disease （COPD）.We aimed to examine the association of spirometric classification and the new GOLD classification with exacerbations,and to compare symptoms in different ways.Methods We investigated 848 patients with stable COPD from 24 hospitals.The annual frequencies of acute exacerbation and hospitalization were compared between the old and new classification.The symptom level was assessed using COPD assessment test （CAT） and modified British Medical Research Council （mMRC） questionnaire.Results A total of 848 patients were included in this study.According to spirometric classification,there were 32 patients of grade Ⅰ （3.8％）,315 of grade Ⅱ （37.1％）,366 of grade Ⅲ （43.2％）,and 135 of grade Ⅳ （15.9％）.According to GOLD 2011 classification,there were 59 patients of group A （7.0％）,172 of group B （20.3％）,55 of group C （6.5％）,and 562 of group D （66.3％）.In spirometric classification,the annual frequencies of acute exacerbation and associated hospitalization were respectively 1 （0-3） and 0 （0-2） for grade Ⅰ; 1 （0-5） and 0 （0-2） for grade Ⅱ; 2 （0-6） and 1 （0-3） for grade Ⅲ,and 3 （0-6） and 2 （0-3） for grade Ⅳ.In GOLD 2011,respectively 0 （0-3） and 0 （0-1） （group A）,1 （0-4） and 0 （0-3） （group B）,1 （0-5） and 0 （0-3） （group C）,and 3 （0-6） and 1 （0-3） （group D）.There were no significant difference between group B and C （Z=-1.347,P=0.178; Z=-0.772,P=0.440,respectively）.The coincidence rate using mMRC=1 and CAT=10 as cutoff points was 86.6％ （734/848,x=0.706）,compared with 77.9％ （661/848,K=0.60） using mMRC=2 and CAT=10.Conclusions Lung function test may be a better predictor of acute exacerbation and associated hospitalization of COPD.It is more appropriate to use mMRC=1 as cutoff point for assessing COPD symptoms.
