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Learning Discriminatory Information for Object Detection on Urine Sediment Image
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作者 Sixian Chan Binghui Wu +2 位作者 Guodao Zhang Yuan Yao Hongqiang Wang 《Computer Modeling in Engineering & Sciences》 SCIE EI 2024年第1期411-428,共18页
In clinical practice,the microscopic examination of urine sediment is considered an important in vitro examination with many broad applications.Measuring the amount of each type of urine sediment allows for screening,... In clinical practice,the microscopic examination of urine sediment is considered an important in vitro examination with many broad applications.Measuring the amount of each type of urine sediment allows for screening,diagnosis and evaluation of kidney and urinary tract disease,providing insight into the specific type and severity.However,manual urine sediment examination is labor-intensive,time-consuming,and subjective.Traditional machine learning based object detection methods require hand-crafted features for localization and classification,which have poor generalization capabilities and are difficult to quickly and accurately detect the number of urine sediments.Deep learning based object detection methods have the potential to address the challenges mentioned above,but these methods require access to large urine sediment image datasets.Unfortunately,only a limited number of publicly available urine sediment datasets are currently available.To alleviate the lack of urine sediment datasets in medical image analysis,we propose a new dataset named UriSed2K,which contains 2465 high-quality images annotated with expert guidance.Two main challenges are associated with our dataset:a large number of small objects and the occlusion between these small objects.Our manuscript focuses on applying deep learning object detection methods to the urine sediment dataset and addressing the challenges presented by this dataset.Specifically,our goal is to improve the accuracy and efficiency of the detection algorithm and,in doing so,provide medical professionals with an automatic detector that saves time and effort.We propose an improved lightweight one-stage object detection algorithm called Discriminatory-YOLO.The proposed algorithm comprises a local context attention module and a global background suppression module,which aid the detector in distinguishing urine sediment features in the image.The local context attention module captures context information beyond the object region,while the global background suppression module emphasizes objects in uninformative backgrounds.We comprehensively evaluate our method on the UriSed2K dataset,which includes seven categories of urine sediments,such as erythrocytes(red blood cells),leukocytes(white blood cells),epithelial cells,crystals,mycetes,broken erythrocytes,and broken leukocytes,achieving the best average precision(AP)of 95.3%while taking only 10 ms per image.The source code and dataset are available at https://github.com/binghuiwu98/discriminatoryyolov5. 展开更多
关键词 Object detection attention mechanism medical image urine sediment
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Studies on Amylase and Degradation of Starch and Pigment of Tobacco Leaf During Process of Flue-Curing 被引量:17
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作者 GONGChang-rong YUANHong-tao +1 位作者 CHENJiang-hua SONGZhao-peng 《Agricultural Sciences in China》 CAS CSCD 2004年第12期931-936,共6页
The changes in the activity of amylase and amylase-isoenzyme and the degradation of starch and pigment of tobacco leaf during flue-curing were studied by using the electric- heated flue-curing barn designed and made... The changes in the activity of amylase and amylase-isoenzyme and the degradation of starch and pigment of tobacco leaf during flue-curing were studied by using the electric- heated flue-curing barn designed and made by the Henan Agricultural University. The temperature and humidity of the barn were controlled automatically. The results indicated that starch in tobacco leaf decreased rapidly and leveled off after 48 h of curring, in the meantime, the content of soluble sugar increased accordingly and reached a peak at the stage of color-fixing. Both of them had a rapid-changing stage in the first 36 hours of yellowing. The changes of starch and soluble sugar contents had highly significant negative-correlation at 1 % level (rNC89 = -0.8962**, rYY85 = -0.9704**). The activity of amylase increased with the proceeding of curing and reached a peak after 36 hours of curing, then decreased. But the activity of amylase kept at a high level when the humidity of curing-environment was very low, even if the tobacco leaf had been dried. The rapid degradation of starch showed a significantly negative correlation with the increase of activity of amylase at 5 % level (rNC89 = -0.8495*, rYY85 = -0.7839*). The degradation of starch and pigment had the same regulation and had highly significant correlation at 1 % level (rNC89= 0.9649**, rYY85= 0.9428**). There were mainly three amylase-isoenzyme bands -A, B, C respectively, in tobacco leaf during flue curing. They were identified as α-AMY, β-AMY, R-AMY, and the activity of β-AMY was the highest. The changes in amylase activity and contents of starch and pigment were affected by the tobacco leaf moisture and environmental humidity during curing. 展开更多
关键词 Tobacco leaf Flue-curing STARCH amylase PIGMENT
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Can the Urine Dipstick Test Be an Alternative in the Screening of Urinary Tract Infections for Inpatients in the Context of a Low-Income Country?
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作者 André Nagalo Odilon D. Kaboré +10 位作者 Senkaye-Lagom Aimée Kissou Hervé Kafando Boukary Kabré Emmanuel Zongo Cheick Ahmed Ouattara Yacouba Sawadogo Aoua Semdé Jacques Zoungrana Armel Poda Sylvain Godreuil Abdoul-Salam Ouédraogo 《Advances in Infectious Diseases》 2023年第4期627-640,共14页
Background: Urinary Tract Infection (UTI), a prevalent bacterial infection in adults, heavily relies on cytobacteriological examination of urine (CBEU) for diagnosis. However, in resource-limited countries, accessibil... Background: Urinary Tract Infection (UTI), a prevalent bacterial infection in adults, heavily relies on cytobacteriological examination of urine (CBEU) for diagnosis. However, in resource-limited countries, accessibility to CBEU remains hindered by cost and availability. This study aims to assess the utility of the Urinary Dipstick Test (UDT) in diagnosing UTIs among hospitalized patients in the context of limited resources. Methods: A cross-sectional study was conducted from February to May 2019, encompassing hospitalized patients who underwent CBEU at the bacteriology unit of Sour? Sanou University Hospital. UDT and CBEU were concurrently performed, and UDT’s analytical and diagnostic performance was evaluated against CBEU, considered the gold standard. Results: A total of 274 CBEU requests were registered, involving 274 patients (159 males) with a mean age of 45.8 ± 21.3 years (ranging from 1 to 90 years). UTI was confirmed in 90 patients, yielding a frequency of 32.85%. The UTI bacteriological profile was dominated by Enterobacteriaceae (75.23%), primarily Escherichia coli (60.55%). Nitrite and Leukocytes were positive in 54 (19.8%) and 157 (53.6%) of the samples tested. Among patients with confirmed UTI, Nitrite, and Leukocytes were positive in 30 (33%) and 71 (79%) patients respectively. UDT demonstrated variable performance based on nitrite and leukocyte combination: Sensitivity (57%-82%), Specificity (7%-98%), Positive Predictive Value (PPV) (43%-57%), Negative Predictive Value (NPV) (43%-67%). UDT performed slightly better in women (NPV = 88%) and inpatients without urinary catheters (NPV = 75% and PPV = 80%). Conclusion: This study underscores UDT’s potential utility in excluding UTIs among women, younger patients, and inpatients without urinary catheters, albeit with limited confidence. The UDT emerges as a complementary tool for UTI screening, particularly in resource-limited settings. 展开更多
关键词 urine Dipstick Test urinary Tract Infection LMICs Burkina Faso
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Effects of Inhabiting and Life Patterns on the UV Spectral Properties of Small Mammalian Herbivores’ Urine
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作者 Junnian Li 《Open Journal of Forestry》 2023年第1期32-44,共13页
It is well known that avian predators can use prey excretions such as urine and feces to track their prey, and the urine and feces of small mammalian herbivores can reflect ultraviolet (UV) light and emit fluorescent ... It is well known that avian predators can use prey excretions such as urine and feces to track their prey, and the urine and feces of small mammalian herbivores can reflect ultraviolet (UV) light and emit fluorescent light. There are still some debates as to whether UV visibility of small mammalian herbivores’ urine is used as a hunting cue by avian raptors. Some studies in Europe have demonstrated that diurnal raptors are capable of utilizing these cues to target key prey species. However, researchers in Australia have argued that raptors do not use the UV visibility of urine while hunting. To our knowledge, there are no reports from Asia concerning the ultraviolet spectral characteristics of small mammal herbivores’ urine. This study examined the UV spectral properties of urine from 6 small mammal herbivores species by comparing the UV reflectance and fluorescence spectra of urine from small mammalian herbivores living in plateau meadows, plateau shrubs, open marshland, farmland, and semi-desert grassland in China. In addition, we compared the UV spectral properties of urine from ground-dwelling species of rodents and subterranean species to determine whether ultraviolet visibility of small mammal herbivores’ urine could be used as a visual signal by Asian vole-eating raptors. The results showed that: 1) the SC<sub>370</sub> values of urine from four small mammal herbivores species were ordered as plateau pika (plateau meadow) > root voles (plateau bush) > reed voles (swampland) > Brandt’s vole (desert grassland);and 2) UV fluorescence peak intensity and the wavelengths of urine from ground-dwelling species (such as the root vole, plateau pika, or Brandt’s vole) were significantly higher than those of subterranean-dwelling species (mandarin vole and plateau zokor). These results indicate that UV visibility of small mammal herbivores’ urine may act as a visual cue for raptors. 展开更多
关键词 Rodents urine Ultraviolet (UV) Light FLUORESCENCE
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Diagnosis of an intermediate case of maple syrup urine disease:A case report
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作者 Yun-Ting Lin Yan-Na Cai +5 位作者 Tzer Hwu Ting Li Liu Chun-Hua Zeng Ling Su Min-Zhi Peng Xiu-Zhen Li 《World Journal of Clinical Cases》 SCIE 2023年第5期1077-1085,共9页
BACKGROUND Maple syrup urine disease(MSUD)is an autosomal recessive genetic disorder caused by defects in the catabolism of the branched-chain amino acids(BCAAs).However,the clinical and metabolic screening is limited... BACKGROUND Maple syrup urine disease(MSUD)is an autosomal recessive genetic disorder caused by defects in the catabolism of the branched-chain amino acids(BCAAs).However,the clinical and metabolic screening is limited in identifying all MSUD patients,especially those patients with mild phenotypes or are asymptomatic.This study aims to share the diagnostic experience of an intermediate MSUD case who was missed by metabolic profiling but identified by genetic analysis.CASE SUMMARY This study reports the diagnostic process of a boy with intermediate MSUD.The proband presented with psychomotor retardation and cerebral lesions on magnetic resonance imaging scans at 8 mo of age.Preliminary clinical and metabolic profiling did not support a specific disease.However,whole exome sequencing and subsequent Sanger sequencing at 1 year and 7 mo of age identified bi-allelic pathogenic variants of the BCKDHB gene,confirming the proband as having MSUD with non-classic mild phenotypes.His clinical and laboratory data were retrospectively analyzed.According to his disease course,he was classified into an intermediate form of MSUD.His management was then changed to BCAAs restriction and metabolic monitoring conforming to MSUD.In addition,genetic counseling and prenatal diagnosis were provided to his parents.CONCLUSION Our work provides diagnostic experience of an intermediate MSUD case,suggesting that a genetic analysis is important for ambiguous cases,and alerts clinicians to avoid missing patients with non-classic mild phenotypes of MSUD. 展开更多
关键词 Maple syrup urine disease BCKDHB gene Branched-chain amino acids Metabolic profiling Genetic analysis Case report
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Diagnostic value of matrix metalloproteinases 2, 7 and 9 in urine for early detection of colorectal cancer
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作者 Liu Peng Xin Zhang +2 位作者 Man-Li Zhang Tao Jiang Peng-Jun Zhang 《World Journal of Gastrointestinal Surgery》 2023年第5期931-939,共9页
BACKGROUND A noninvasive biomarker with high diagnostic performance is urgently needed for the early diagnosis of colorectal cancer(CRC).AIM To evaluate the diagnostic value of matrix metalloproteinases(MMPs)2,7 and 9... BACKGROUND A noninvasive biomarker with high diagnostic performance is urgently needed for the early diagnosis of colorectal cancer(CRC).AIM To evaluate the diagnostic value of matrix metalloproteinases(MMPs)2,7 and 9 in urine for CRC.METHODS Of 59 healthy controls,47 patients with colon polyps and 82 patients with CRC were included in this study.Carcinoembryonic antigen(CEA)in serum and MMP2,MMP7,and MMP9 in urine were detected.The combined diagnostic model of the indicators was established by binary logistic regression.The receiver operating characteristic curve(ROC)of the subjects was used to evaluate the independent and combined diagnostic value of the indicators.RESULTS The MMP2,MMP7,MMP9,and CEA levels in the CRC group differed significantly from levels in the healthy controls(P<0.05).The levels of MMP7,MMP9,and CEA also differed significantly between the CRC group and the colon polyps group(P<0.05).The area under the curve(AUC)distinguishing between the healthy control and the CRC patients using the joint model with CEA,MMP2,MMP7 and MMP9 was 0.977,and the sensitivity and specificity were 95.10%and 91.50%,respectively.For early-stage CRC,the AUC was 0.975,and the sensitivity and specificity were 94.30%and 98.30%,respectively.For advanced stage CRC,the AUC was 0.979,and the sensitivity and specificity were 95.70%and 91.50%,respectively.Using CEA,MMP7 and MMP9 to jointly established a model distinguishing the colorectal polyp group from the CRC group,the AUC was 0.849,and the sensitivity and specificity were 84.10%and 70.20%,respectively.For early-stage CRC,the AUC was 0.818,and the sensitivity and specificity were 76.30%and 72.30%,respectively.For advanced stage CRC,the AUC was 0.875,and the sensitivity and specificity were 81.80%and 72.30%,respectively.CONCLUSION MMP2,MMP7 and MMP 9 may exhibit diagnostic value for the early detection of CRC and may serve as auxiliary diagnostic markers for CRC. 展开更多
关键词 Colorectal cancer Early detection Matrix metalloproteinases urine BIOMARKER
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Metabolic dynamics in chronic gastritis:Examining urinary profiles post Helicobacter pylori eradication
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作者 Imshaal Musharaf Abdulqadir J Nashwan 《World Journal of Clinical Cases》 SCIE 2024年第16期2698-2700,共3页
Chronic gastritis is the persistent and insidious inflammation of the gastric lining.Helicobacter pylori(H.pylori)has been identified as the most common cause of chronic gastritis and consequently elimination of H.pyl... Chronic gastritis is the persistent and insidious inflammation of the gastric lining.Helicobacter pylori(H.pylori)has been identified as the most common cause of chronic gastritis and consequently elimination of H.pylori can lead to its cure.This editorial explores the use of urinary metabolic profiles before and after eradication to identify biomarkers that can aid in prognosis and treatment.Despite providing promising insights,there are limitations such as a small sample size(17 patients),a narrow treatment period of 2 wk,and treatment heterogeneity,which raise concerns.Nevertheless,these findings have opened a gateway to enhancing the treatment and prognosis of chronic gastritis through urinary metabolomics. 展开更多
关键词 GASTRITIS Helicobacter pylori Chronic gastritis urine metabolomics Quadruple therapy Precancerous lesions
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The Dynamics of Changes in Starch and Lipid Droplets and Sub-Cellular Localization of β-Amylase During the Growth of Lily Bulbs 被引量:1
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作者 WU Sha-sha WU Jin-di +2 位作者 JIAO Xue-hui ZHANG Qi-xiang LV Ying-min 《Journal of Integrative Agriculture》 SCIE CAS CSCD 2012年第4期585-592,共8页
The ultra-structure of mother and outer daughter scales of Lilium Oriental hybrid Sorbonne were studied using transmission electron microscope to examine the sub-cellular localization of starch and lipid droplets duri... The ultra-structure of mother and outer daughter scales of Lilium Oriental hybrid Sorbonne were studied using transmission electron microscope to examine the sub-cellular localization of starch and lipid droplets during growth and development from shoot emergence to senescence.The contents of starch granules and lipid droplets in the cell of the mother scales decreased significantly from shoot emergence to anthesis,indicating that these scales served as a source for growth and development.After flowering,the number of starch granules and lipid droplets increased dramatically,and finally the cells were filled with the above molecules indicating that the bulb becomes a major sink during bulb enlargement.Ultrastructure observation also showed that symplastic pathway is the main pathway in cells in the exchange and transportation of material during bulb development.The activity of β-amylase,one of the key enzymes catalyzing starch breakdown,showed a similar trend.The enzyme sub-cellular localization via immune-gold electron-microscopy showed that βamylase was predominantly located together with starch granules,while the gold particles were scarcely found in other sub-cellular compartments.The result suggested that this enzyme is compartmented together with its functional substrate supporting its function in catalyzing starch breakdown in living plant cells. 展开更多
关键词 Lilium Oriental hybrids BULB scale source and sink ULTRA-STRUCTURE Β-amylase sub-cellular localization
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影响Urine-H-11干化学法检测尿液分析的因素 被引量:1
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作者 蒋翠霞 韦慧玲 +1 位作者 师勇 余秀瑾 《中国医药指南》 2009年第2期101-102,共2页
Urine—H—11尿液试纸是干化学法检测尿液分析的一种方法,利用干化学法进行尿液分析,能够简便,快速为临床诊断、治疗、预防和监测疾病提供可靠的实验依据,但是,Urine—H—11干化学法也受许多因素的影响,而导致结果的准确性,为了... Urine—H—11尿液试纸是干化学法检测尿液分析的一种方法,利用干化学法进行尿液分析,能够简便,快速为临床诊断、治疗、预防和监测疾病提供可靠的实验依据,但是,Urine—H—11干化学法也受许多因素的影响,而导致结果的准确性,为了使大家更多的了解影响Urine-H—11干化学法检测尿液的各项因素,准确的为临床提供诊断依据,现将有关Urine—H—11干化学法检测尿液的影响因素总结如下: 展开更多
关键词 urine—H-11 干化学法 检测 尿液分析
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家蚕幼虫血液淀粉酶(Amylase)研究
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作者 钟生泉 伴野丰 《蚕学通讯》 1989年第3期12-13,共2页
家蚕的淀粉酶广泛分布在蚕的血液、消化液、消化管及卵巢中。幼虫血液和消化液淀粉酶的活性,依品种而有显著差异,且其遗传受在同一染色体上极接近的不同位置的基因所控制(松本,1933,1934)。家蚕幼虫血液淀粉酶活性的成分组成,伴随着... 家蚕的淀粉酶广泛分布在蚕的血液、消化液、消化管及卵巢中。幼虫血液和消化液淀粉酶的活性,依品种而有显著差异,且其遗传受在同一染色体上极接近的不同位置的基因所控制(松本,1933,1934)。家蚕幼虫血液淀粉酶活性的成分组成,伴随着幼虫发育而变动(河口,1982)。著者就不同家蚕品种的原种及其杂交F<sub>1</sub>的幼虫血液淀粉酶的差异进行了调查,现将结果报告如下。 展开更多
关键词 淀粉酶活性 amylase 家蚕幼虫 家蚕品种 供试蚕品种 石戈 松本 农学部 九州大学 电泳凝胶
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Effects of Cadmium Stress on Seed Germination, Seedling Growth and Seed Amylase Activities in Rice (Oryza sativa) 被引量:15
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作者 Jun-yu HE Yan-fang REN +1 位作者 Cheng ZHU De-an JIANG 《Rice science》 SCIE 2008年第4期319-325,共7页
关键词 cadmium RICE seed germination root length mitotic index amylase activity
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Inhibitory activities of microalgal fucoxanthin againstα-amylase,α-glucosidase, and glucose oxidase in 3T3-L1cells linked to type 2 diabetes 被引量:7
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作者 KAWEE-AI Arthitaya KIM Aaron Taehwan KIM Sang Moo 《Journal of Oceanology and Limnology》 SCIE CAS CSCD 2019年第3期928-937,共10页
Postprandial hyperglycemia is an early indication of type 2 diabetes and the target of many anti-diabetic and anti-obesity studies.α-Glucosidase and α-amylase are the crucial factors in regulating starch digestion a... Postprandial hyperglycemia is an early indication of type 2 diabetes and the target of many anti-diabetic and anti-obesity studies.α-Glucosidase and α-amylase are the crucial factors in regulating starch digestion and glucose absorption,making them key targets for many studies to treat postprandial hyperglycemia.We studied the inhibitory activities of microalgal fucoxanthin against rat-intestinalα-glucosidase and pancreaticα-amylase along with the antidiabetic eff ect to induce diff erentiation in 3T3-L1 pre-adipocytes using Oil Red-O staining.Fucoxanthin displayed strong hindrance activities towardα-amylase in a concentration-dependent manner,with an IC50 value of 0.68mmol/L,whereas weak inhibitory activity against α-glucosidase,with an IC 50 value of 4.75 mmol/L.Fucoxanthin also considerably elevated glucose oxidase activity in 3T3-L1 cells by 31.3%at 5μmol/L.During adipocyte differentiation,fucoxanthin showed lipid accumulation in 3T3-L1 cells with no cytotoxicity up to 20μmol/L.However,fucoxanthin had no inhibitory activity on glucose-6-phosphate dehydrogenase.These results suggest that fucoxanthin might be useful for the prevention of obesity or diabetes by inhibiting carbohydrate-hydrolyzing enzymes and lipid accumulation and be utilized as an ingredient for a functional food or dietary supplement. 展开更多
关键词 Α-GLUCOSIDASE amylase diabetes FUCOXANTHIN glucose OXIDASE MICROALGAE
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Lipase and pancreatic amylase activities in diagnosis of acute pancreatitis in patients with hyperamylasemia 被引量:6
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作者 Rong-Wei Yang, Zhe-Xin Shao, Yi-Yi Chen, Zhou Yin and Wen-Juan Wang Clinical Laboratory, First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou 310003, China and Clinical Laboratory, Zhejiang Xinhua Hospital, Hangzhou 310003 , China 《Hepatobiliary & Pancreatic Diseases International》 SCIE CAS 2005年第4期600-603,共4页
BACKGROUND: Measurement of total serum amylase (AMY) is the most widely used biochemical test for the diagnosis of acute pancreatitis, but it is commonly considered a nonspecific marker. To improve the biochemical dia... BACKGROUND: Measurement of total serum amylase (AMY) is the most widely used biochemical test for the diagnosis of acute pancreatitis, but it is commonly considered a nonspecific marker. To improve the biochemical diagnosis of acute pancreatitis, lipase ( LIP ) and pancreatic amylase (PAMY) have been tested in recent years. The present study was designed to evaluate whether serum LIP and pancreatic PAMY tests could replace total amylase test to improve diagnostic efficiency in the evaluation of acute pancreatitis in patients with hyperamylasemia. METHODS: LIP and PAMY values were determined in serum samples from 92 patients with hyperamylasemia. Reference values for each enzyme were derived from serum samples of 147 healthy subjects. The activities of LIP and PAMY in patients with various diseases were shown directly by the boxplot graph. The diagnostic accuracy of LIP and PAMY was defined as the area under the receiver operating characteristic (ROC) curve. Their sensitivity and specificity in detecting acute pancreatitis at varying cutoff points were shown by the curve, and the best cutoff value for each enzyme was shown by the modified ROC curve. The diagnostic values of LIP, PAMY and LIP + AMY with each upper limit of reference range (ULR) were compared with the corresponding best cutoff values. RESULTS: The references values of LIP and PAMY were 12.2-47.6 U/L and 28-95 U/L, respectively. These values in patients with acute pancreatitis were higher than those patients with other diseases. The areas under the ROC curve ( AUC) of LIP and PAMY were 0. 799 and 0. 792, respectively, With the best diagnostic cutoff point of maximum (sensitivity + specificity) -100%, we obtained values of 97.9 U/L(LIP97.9 =2. 06 × ULR) for LIP and 209 U/L (PAMY209 =2.20 ×ULR) for PAMY. The best cutoff values for LIP, PAMY and LIP +AMY demonstrated the specificity, positive predictive value, and diagnostic efficiency higher than the corresponding ULRs. CONCLUSIONS: Serum LIP and PAMY are specific for the pancreas and might replace total amylase for the diagnosis of acute pancreatitis in hyperamylasemia patients. LIP97.9 is more efficient than PAMY209 in the diagnosis of acute pancreatitis. A combined test of both enzymes is not superior to single test of either enzyme in diagnostic accuracy. 展开更多
关键词 pancreatic injury LIPASE pancreatic amylase
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Determination of urine catecholamines and metanephrines by reversed-phase liquid chromatography-tandem mass spectrometry 被引量:6
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作者 CHEUK Man-Yung LO Yun-Chuen POON Wing-Tat 《色谱》 CAS CSCD 北大核心 2017年第10期1042-1047,共6页
The measurement of urine catecholamine and metanephrine concentrations is important for biochemical screening and diagnosis of pheochromocytoma.The goal of this work was to develop a simple liquid chromatography-tande... The measurement of urine catecholamine and metanephrine concentrations is important for biochemical screening and diagnosis of pheochromocytoma.The goal of this work was to develop a simple liquid chromatography-tandem mass spectrometry(LC-MS/MS)method for determining catecholamines and metanephrines in urine to replace an existing liquid chromatographic method using electrochemical detection.Urine samples were prepared using Oasis weak-cation-exchange cartridges.The eluate was analyzed on an Agilent ZORBAX Eclipse Plus Phenyl-Hexyl column in 3 min.Adrenaline,noradrenaline,dopamine,metanephrine,normetanephrine,and their deuterated internal standards were monitored in positive electrospray ionization mode by multiple reaction monitoring(MRM).No evidence of ion suppression was observed.The assay was linear up to 5μmol/L for adrenaline,5μmol/L for noradrenaline,6.1μmol/L for dopamine,5.6μmol/L for metanephrine,and 34.6μmol/L for normetanephrine,with lower limits of quantification of 5,5,12,6 and 7nmol/L,respectively.The intra-day and inter-day precisions for all analytes ranged from 0.59%to 4.64%and1.98%to 4.80%,respectively.External quality assurance samples were assayed and showed excellent agreement with the target values.This simple method provides an improved assay for determining urine catecholamines and metanephrines. 展开更多
关键词 liquid chromatography-tandem mass SPECTROMETRY (LC-MS/MS) METANEPHRINES CATECHOLAMINES PHEOCHROMOCYTOMA urine
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Amylase Production by the Marine Yeast Aureobasidium pullulans N13d 被引量:5
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作者 LI Haifeng CHI Zhenming +1 位作者 WANG Xiaohong a MA Chunling 《Journal of Ocean University of China》 SCIE CAS 2007年第1期60-65,共6页
The marine yeast strain N13d, producing an extracellular amylase, was isolated from the deep sea sediments of the Pa-cific Ocean. This strain was identified to be Aureobasidium pullulans by 18S rRNA gene sequence anal... The marine yeast strain N13d, producing an extracellular amylase, was isolated from the deep sea sediments of the Pa-cific Ocean. This strain was identified to be Aureobasidium pullulans by 18S rRNA gene sequence analysis and routine yeast identi-fication methods. The optimal sea water medium for amylase production by this yeast strain was 1.0% peptone and 1.0% soluble starch with pH 4.0. The optimal conditions for amylase production by this yeast strain were with temperature 28 ℃, aeration rate 6 Lmin-1 and agitation speed 250 rmin-1. Under these conditions, 58.5 units of amylase activity per mg protein were produced within 56 h of fermentation. 展开更多
关键词 extracellular amylase marine yeast Aureobasidium pullulans FERMENTATION
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Characterization of a Novel Mesophilic Bacterial Amylase Secreted by ZW2531-1, a Strain Newly Isolated from Soil 被引量:3
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作者 WANG Yang LI Fan GAO Chao-hui ZHANG Ying-Jiu 《Chemical Research in Chinese Universities》 SCIE CAS CSCD 2009年第2期198-202,共5页
A novel mesophilic bacterial amylase, named oligosaccharide-producing multifunctional amylase(OPMA), was discovered and characterized. OPMA is an extracellular enzyme secreted by ZW253 1-1, a strain newly isolated f... A novel mesophilic bacterial amylase, named oligosaccharide-producing multifunctional amylase(OPMA), was discovered and characterized. OPMA is an extracellular enzyme secreted by ZW253 1-1, a strain newly isolated from Chinese soil. It could be purified to homogeneity from the culture supernatant of ZW2531-1 by 30%-60% saturated ammonium sulfate precipitation, followed by twice Sephadex gel filtration chromatography. OPMA is a 66 kDa protein based on SDS-PAGE and has an isoelectric point(p/) at pH=5.3 by Isoelectric focusing electrophoresis(WE). It only catalyzes the degradation of starch, rather than other alpha-l,4- and/or 1,6-glucan polysaccbarides such as fl-cyclomaltodextrin and pullulan. OPMA degraded starch to produce several oligosccharides including maltose, maltotriose, and isomaltotriose as the major end-products, and perhaps other oligosaccharides such as isomalto- tetraose, rather than glucose. OPMA exhibited optimal catalytic activity at a reaction temperature of 50 ℃ and pH=6.0, as determined by orthogonal test. Under the optimal reaction conditions, purified OPMA bad a specific activity of 13.75 U/rag. These findings suggest that OPMA could be used for the production of some oligosaccharides beneficial to the food industry and medicine. 展开更多
关键词 amylase BACTERIUM OLIGOSACCHARIDE Purification STARCH
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A Study on Bisphenol A,Nonylphenol,and Octylphenol in Human Urine amples Detected by SPE-UPLC-MS 被引量:13
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作者 XIAO Jing SHAO Bing +2 位作者 WU XiaoYan SUN XiaoJie WU YongNing 《Biomedical and Environmental Sciences》 SCIE CAS CSCD 2011年第1期40-46,共7页
Objective To establish a comprehensive analytical method based on SPE‐UPLC‐MS for the simultaneous determination of bisphenol A (BPA), nonylphenol (NP), and octylphenol (OP) in urine samples. Methods Sixty uri... Objective To establish a comprehensive analytical method based on SPE‐UPLC‐MS for the simultaneous determination of bisphenol A (BPA), nonylphenol (NP), and octylphenol (OP) in urine samples. Methods Sixty urine samples collected from healthy subjects were analyzed for BPA, NP, and OP concentrations. The samples were de‐conjugated by adding β‐glucuronidase and sulfatase. After the enzymatic treatment, the samples were subjected to the OASIS HLB column solid phase extraction cartridges so as to be cleaned and concentrated. The UPLC separation was performed on a Acquity UPLCTM BEH C18 column (2.1×100 mm, 1.7 μm) with a gradient elution system of methanol‐water as the mobile phase. Triple‐quadrupole mass spectrometry analyzer was used for the qualitative and quantitative analysis of UPLC‐MS/MS system. Results The limit of detection of BPA, NP, and OP was 0.10, 0.10, and 0.15 ng/mL, respectively. The recoveries of BPA, NP and OP were 80.1%‐108%, 81.3%‐109%, and 81.5%‐98.7%, respectively. Among the 60 urine samples, BPA was detected in 8 samples at the level of 0.297‐32.7ng/mL, NP was detected in 29 samples at the level of 1.69‐27.8 ng/mL, and OP was detected in 17 samples at the level of 0.407‐11.1 ng/mL. Conclusion The method is simple with high sensitivity and selectivity, and is suitable for the determination of BPA, NP, and OP in urine. As shown by our analysis , BPA, NP, and OP appear to be prevalent in human urine. This is particularly true for NP. The results from our study is therefore valuable for future studies to assess the exposure to BPA, NP, and OP in the general population. 展开更多
关键词 Bisphenol A NONYLPHENOL OCTYLPHENOL urine Solid phase extraction Ultra high performance liquid chromatography ‐mass/mass
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Simultaneous determination of fluorine and iodine in urine by ion chromatography with electrochemical pretreatment 被引量:4
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作者 Kang Kang Hu Wei Xiong Huang Yu Hua Su Rong Zong Hu 《Chinese Chemical Letters》 SCIE CAS CSCD 2009年第12期1483-1486,共4页
A new method for the simultaneous determination of fluorine and iodine in urine by ion chromatography (IC) with electrochemical pretreatment has been developed. The pretreatment was performed in a novel electrochemi... A new method for the simultaneous determination of fluorine and iodine in urine by ion chromatography (IC) with electrochemical pretreatment has been developed. The pretreatment was performed in a novel electrochemical oxidationneutralization device (EOND), in which iodide of the sample was oxidized to iodate and the alkaline digestion sample solution was neutralized. Under the optimized conditions, the limits of detection (LOD, S/N = 3) were 2.5 μg/L for fluoride and 20 μg/L for iodate, respectively. The recoveries were in the range of 93-102% for fluoride and 86-98% for iodate. 展开更多
关键词 FLUORINE IODINE urine Electrochemical pretreatment Ion chromatography
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Value of a new stick-type rapid urine test for the diagnosis of Helicobacter pylori infection in the Vietnamese population 被引量:4
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作者 Duc T Quach Toru Hiyama +5 位作者 Fumio Shimamoto Quang D Le Linh X Ho Nhu HT Vu Masaharu Yoshihara Naomi Uemura 《World Journal of Gastroenterology》 SCIE CAS 2014年第17期5087-5091,共5页
AIM:To assess the value of a new test for the diagnosis of Helicobacter pylori(H.pylori) infection,Rapirun H.pylori Antibody Stick(Rapirun Stick),in a Vietnamese population.METHODS:Eligible patients without previo... AIM:To assess the value of a new test for the diagnosis of Helicobacter pylori(H.pylori) infection,Rapirun H.pylori Antibody Stick(Rapirun Stick),in a Vietnamese population.METHODS:Eligible patients without previous history of H.pylori eradication were recruited.Rapid urease test(RUT) and histologic examination were used to diagnose the H.pylori infection.Patients were considered H.pylori positive when the RUT results were positive and/or the bacteria were detected histologically.Rapirun Stick tests were performed using urine samples,and the results were compared with the other 2 methods.RESULTS:We enrolled 200 patients with a mean age of 36(range,18-76) years.There were 116 females and 84 males.Of the 200 patients,111(55.5%) were diagnosed as being H.pylori positive.The sensitivity,specificity,and accuracy of the Stick test were 84.7%,89.9%,and 87.0%,respectively.There were 17(8.5%) falsenegative patients and 9(4.5%) false-positive patients.CONCLUSION:The Rapirun Stick test has high sensitivity,specificity,and accuracy for the diagnosis of H.pylori infection in the Vietnamese population.The test can be clinically applied in Vietnamese populations. 展开更多
关键词 HELICOBACTER PYLORI urine test Rapirun STICK Viet
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Combination of two-hour post-endoscopic retrograde cholangiopancreatography amylase levels and cannulation times is useful for predicting post-endoscopic retrograde cholangiopancreatography pancreatitis 被引量:4
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作者 Shiro Hayashi Tsutomu Nishida +10 位作者 Hiromi Shimakoshi Akiyoshi Shimoda Takahiro Amano Aya Sugimoto Kei Takahashi Kaori Mukai Tokuhiro Matsubara Masashi Yamamoto Sachiko Nakajima Koji Fukui Masami Inada 《World Journal of Gastrointestinal Endoscopy》 CAS 2016年第20期777-784,共8页
AIM To estimate the efficacy of 2 h post-endoscopic retrograde cholangiopancreatography(ERCP) serum amylase levels and other factors for predicting postERCP pancreatitis.METHODS This was a retrospective,single-center ... AIM To estimate the efficacy of 2 h post-endoscopic retrograde cholangiopancreatography(ERCP) serum amylase levels and other factors for predicting postERCP pancreatitis.METHODS This was a retrospective,single-center cohort study of consecutive patients who underwent ERCP from January 2010 to December 2013.Serum amylase levels were measured 2 h post-procedure,and patient- and procedure-related pancreatitis(PEP) risk factors wereanalyzed using a logistic model.RESULTS A total of 1520 cases(average age 72 ± 12 years,60% male) were initially enrolled in this study,and 1403 cases(725 patients) were ultimately analyzed after the exclusion of 117 cases.Fifty-five of these cases developed PEP.We established a 2 h serum amylase cutoff level of two times the upper limit of normal for predicting PEP.Multivariate analysis revealed that a cannulation time of more than 13 min [odds ratio(OR) 2.28,95%CI:1.132-4.651,P=0.0210] and 2 h amylase levels greater than the cutoff level(OR=24.1,95%CI:11.56-57.13,P<0.0001) were significant predictive factors for PEP.Forty-seven of the 55 patients who developed PEP exhibited 2 h amylase levels greater than the cutoff level(85%),and six of the remaining eight patients who developed PEP(75%) required longer cannulation times.Only 2 of the 1403 patients(0.14%) who developed PEP did not exhibit concerning 2 h amylase levels or require longer cannulation times.CONCLUSION These findings indicate that the combination of 2 h post-ERCP serum amylase levels and cannulation times represents a valuable marker for identifying patients at high risk for PEP. 展开更多
关键词 Serum amylase LEVELS CANNULATION time Post-endoscopic retrograde CHOLANGIOPANCREATOGRAPHY PANCREATITIS Predictor
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