Cut-off Values of Diagnostic Indices to Detect Iron Deficiency in Chinese Breast-fed Infants

Iron deficiency anemia is one of the most prevalent nutritional deficiency worldwide. The commonly used cut-off values for identifying iron deficiency are extrapolated from older children and may not be suitable for infants. Therefore, our study aimed to establish appropriate cut-off values for the evaluation of iron status in Chinese infants. Pregnant women who delivered at 〉37 gestational weeks with normal iron status were recruited. Later, infants with normal birth weight and who were breastfed in the first 4 months were selected. Blood samples were collected to assess hemoglobin, serum ferritin, soluble transferrin receptor, mean corpuscular volume and free erythrocyte protoporphyrin. Cut-offs of all iron indices were determined as the limit of 95% confidence interval.

Evaluation of an Innovative Diagnostic Method for Detection of Antibodies and Antigens

Reports manifest a continuing need for the development of rapid and on-site (point of care) assays. Current diagnostic methods commonly used for detection of antibodies and antigens have significant limitations. Scientists at Micro Detect, Inc. have developed an innovative diagnostic device (method) that can be utilized broadly for antibody/antigen interactions including diagnostic assays in the medical, veterinary and food industries. The developed device can be utilized for the detection of antibodies against a single antigen or vice versa. It can also be tailored for specific panels that detect antigens or antibodies for diverse infectious agents, proteins, hormones, tumor markers, autoimmune markers, and allergens. Additionally, it can also be used for detection of toxins, antitoxins, nucleic acids, enzymes, drugs, etc. in both humans and animals. Specimens used in different formats of the device can be tears, saliva, whole blood, serum, plasma, urine, stool, and other bodily discharges. The good intra and inter precisions and acceptable linearity of the device support reliable use of the device. The CV of the device is 1.9% - 2.2%. Likewise, the performance of the device using 92 confirmed negative and positive specimens via a typical assay showed 100% sensitivity, 80% specificity, 96.8% efficacy, 80% positive predictive value, and 100% negative predictive value. The results of our feasibility study suggest reliable utility of a device for rapid, easy-to-use, inexpensive, and on-site (point of care) diagnostic assays. This presents a potential breakthrough in diagnostic methodologies that can be integrated into modern medicine and food industries.

Relation of predictive value to sensitivity and specificity of a diagnostic test

This paper discusses how the positive and negative predictive values vary withcontrary variations of sensitivity and specificity at a certain disease prevalence.Let thesensitiviy be Se and the specificity be Sp at the initial cutoff point,correspondingly Se’and Sp’ at a new cutoff point:A=Se’/Se:B-(1-Sp’)/(1-Sp):C=Sp’/Sp;D=(I-Se’)/(I-Se).Moving the cutoff point from the initial point to the new point,if the contrary variationsof the sensitivity and specificity satisfy the inequality A】B,then the positive predictivevalue increases,otherwise it decreases or remains unchanged.If the variations satisfy theinequality C】D,then the negative prcdictive value increases,otherwise it decreasses or re-mains unchanged.

Determination of the diagnostic value of the resazurin reduction assay for evaluating boar semen by receiver operating characteristic analysis

Aim： To assess that metabolic status of spermatozoa could provide a useful tool for evaluation of semen quality. Methods： The accuracy of the spectrophotometric application of the resazurin reduction assay was assessed using receiver operating characteristic （ROC） analysis. Results： Areas under ROC curves （AUC） for motile sperm concentration and sperm index （SI） （sperm concentration multiplied by the square root of percentage sperm motility multiplied by the percentage normal sperm morphology） were 0.922. The best discrimination between poor and good semen samples according to the SI was achieved at a cut-off point of A610 = 0.209, where high sensitivity （94.1%） and specificity （91.7%） were calculated. The assay was less accurate when motile sperm concentration was used as the criterion value, yielding sensitivity of 88.2% and specificity of 87.5%, respectively. Likelihood ratios （LR） indicate that absorbances lower than 0.209 were at least 11.3 times as likely to be found in good semen samples than those in poor according to the SI, whereas in the case of motile sperm concentration, the LR was calculated to be 7.06. Conclusion： These results show that the resazurin reduction assay combined with spectrophotometry is an accurate method of assessing the quality of boar semen.

Study on divertor heat flux under n=3 and n=4 resonant magnetic perturbations using infrared thermography diagnostic in EAST

Resonant magnetic perturbations(RMPs)with high toroidal mode number n are considered for controlling edge-localized modes(ELMs)and divertor heat flux in future ITER H-mode operations.In this paper,characteristics of divertor heat flux under high-nRMPs(n=3 and 4)in H-mode plasma are investigated using newly upgraded infrared thermography diagnostic in EAST.Additional splitting strike point(SSP)accompanying with ELM suppression is observed under both RMPs with n=3 and n=4,the SSP in heat flux profile agrees qualitatively with the modeled magnetic footprint.Although RMPs suppress ELMs,they increase the stationary heat flux during ELM suppression.The dependence of heat flux on q_(95)during ELM suppression is preliminarily investigated,and further splitting in the original strike point is observed at q 495=during ELM suppression.In terms of ELM pulses,the presence of RMPs shows little influence on transient heat flux distribution.

Determination of a Cut-Off Point of a Scale for Achievement Motive in Geriatrics That Predicts the Frequency of Undertaking Instrumental Activities of Daily Living in Community-Dwelling Elderly People

Background: Among elderly people, rehabilitation is important for reducing the risk of falls and hospitalization and to maintain an independent life for longer. Motivation is a factor for elderly people to lead an active daily life and leave home more frequently. Purpose: The purposes of this study were to determine the optimal cut-off point in the Scale for Achievement Motive in Geriatrics (SAMG) that could identify individuals as inactive or active, based on the Frenchay Activities Index (FAI), and to compare characteristics between active and inactive groups classified by the cut-off point. Methods: A cross-sectional study of 285 community-dwelling elderly people measured SAMG and FAI and physical function. Receiver operating characteristic (ROC) analysis was used to calculate the area under the curve (AUC) that was the optimal cut-off point for the SAMG total score, with the associated sensitivity and 1-specificity when compared with the FAI results. Demographic parameters and physical function were compared between two groups defined by cut-off point. Results: The AUC was 0.78, the optimal cut-off for SAMG total score for indicating inactivity was ≤48, the sensitivity was 77.98% and the 1-specificity was 75.00%. The group with SAMG score >48 was characterized by a significantly higher proportion of women, fewer people sharing a house, and participation in more hobbies. Discussion: A cut-off point of 48 in the SAMG could be a predictive index of motivation toward goals for individuals with inactive daily activities. The group with score higher than the cut-off was characterized by more women, fewer people living together, and more hobbies than the group with lower scores.

Determination of the diagnostic value of the resazurin reduction assay for evaluating boar semen by receiver operating cha-racteristic analysis

Aim:To assess that metabolic status of spermatozoa could provide a useful tool for evaluation of semen quality. Methods:The accuracy of the spectrophotometric application of the resazurm reduction assay was assessed using receiver operating characteristic(ROC)analysis.Results:Areas under ROC curves(AUC)for motile sperm concen- tration and sperm index(SI)(sperm concentration multiplied by the square root of percentage sperm motility multi- plied by the percentage normal sperm morphology)were 0.922.The best discrimination between poor and good semen samples according to the SI was achieved at a cut-off point of A_(610)=0.209,where high sensitivity(94.1%)and specificity(91.7%)were calculated.The assay was less accurate when motile sperm concentration was used as the criterion value,vielding sensitivity of 88.2% and specificity of 87.5%,respectively,Likelihood ratios(LR)indicate that absorbances lower than 0.209 were at least 11.3 times as likely to be found in good semen samples than those in poor according to the SI,whereas in the case of motile sperm concentration,the LR was calculated to be 7.06.Conclusion: These results show that the resazurin reduction assay combined with spectrophotometry is an accurate method of assessing the quality of boar semen.

从“浊气在上,则生月真胀”论夹脊穴治疗功能性腹胀

本研究基于对《黄帝内经》“浊气在上,则生[月真]胀”的分析阐释,认为功能性腹胀病机关键在于生理性浊气不归其位,日久生浊邪,使中焦气机升降失常。浊为阴邪,功能性腹胀属阴位疾病,与之相应,背部夹脊穴属阳位,具有借腹气街及任督循环多维联络腹部的功能,为调节腹部诸脏腑经脉气机之枢纽。基于此,笔者提出可从阳治阴,用经络诊察的方式,着重取与腹气街相应的T11~L5夹脊穴区的病证反应点,以散局部有形浊邪;再基于督脉-夹脊穴-足太阳膀胱经三者特殊的位置关系,取夹脊穴通调任督与脏腑之气,整体复升降以还浊气,调阴阳之失衡,解除机体因“浊气在上”而生腹胀的病理状态,以期对针灸临床治疗功能性腹胀提供思路。

NT-proBNP及NT-proBNP/Crea用于鉴别心源性呼吸困难和肺源性呼吸困难的诊断截点研究

目的建立适合中国人群不同年龄段的诊断和鉴别诊断以急诊呼吸困难为主诉的心力衰竭的NT-proBNP和NT-proBNP/Crea的cut off值。方法将133例急性呼吸困难患者分为心源性呼吸困难组(n=55)和肺源性呼吸困难组(n=78),根据年龄、性别、基本生化指标NT-proBNP及Crea水平,绘制ROC曲线,并进行统计学分析。结果心源性呼吸困难组中NT-proBNP为2744(1076,7329)pg/mL,而在肺源性呼吸困难组中NT-proBNP水平为268(80,918)pg/mL,差异具有统计学意义。心源性呼吸困难组NT-proBNP/Crea为31.3(12.02,61.21),肺源性呼吸困难组NT-proBNP/Crea为4.48(1.13,12.24),两组间差异具有统计学意义。NT-proBNP/Crea诊断心源性呼吸困难的能力是0.822(95%可信区间),最佳诊断截点是15.45。结论NT-proBNP和NT-proBNP/Crea在鉴别心源性呼吸困难和肺源性呼吸困难上有不同的诊断截点,且中国人群不同年龄段亦有不同的诊断截点。可以帮助急诊医生快速、准确诊断和鉴别诊断心源性呼吸困难及肺源性呼吸困难。

危害分析和关键控制点法在产前诊断技术服务医疗风险管理中的研究与应用

本文运用危害分析和关键控制点(HACCP)法对产前诊断技术服务医疗风险进行管控,以提高医疗机构风险防控效能,保障母婴安全。通过对产前诊断技术服务流程进行危害分析,建立4个维度(资质管理和组织建设、临床技术、实验室检测技术、医学影像诊断技术)18个关键控制点(CCP),针对CCP制订计划、实施管控措施、评价管控效果。HACCP实施后,产前诊断技术服务的风险行为减少,不良医疗结局(漏诊、误诊、投诉举报、医疗纠纷、行政处罚)发生率降低,同时,构建科学有效的风险管控体系,提高了机构及工作人员的风险预警意识和诊断技术水平。

肌骨超声检查在痛风性关节炎中的声像图特征及诊断价值分析

目的探讨肌骨超声(musculoskeletal ultrasound,MSUS)检查在痛风性关节炎中的声像图特征及诊断价值。方法选取厦门医学院附属第二医院2021年5月—2023年4月收治的四肢关节疼痛或肿胀并接受肌骨超声检查的80例患者,依据临床确诊结果分为痛风组(痛风性关节炎,n=40)与对照组(非痛风性炎性关节病,n=40)。比较2组患者关节受累部位差异、MSUS检查声像图特征及差异,评价MSUS检查在痛风性关节炎中的诊断效能,比较痛风组中尿酸升高组与尿酸正常组间MSUS检查声像图差异。结果痛风组40例患者共累及86个关节,对照组40例患者共累及71个关节,痛风组中第一跖趾关节、踝关节较对照组更易受累,差异有统计学意义(P<0.05);对照组中指关节较痛风组更易受累,差异有统计学意义(P<0.05)。痛风组中双轨征、强或高回声点、痛风石3种声像图检出分别为38、44、13处,高于对照组的0、2、0处,差异有统计学意义(P<0.05)。痛风组双轨征38处,强或高回声点44处,痛风石13处,三者中至少一项阳性者共27例;对照组双轨征0处,强或高回声点2处,痛风石0处,三者中至少有一项阳性者2例。MSUS检查中双轨征、强或高回声点、痛风石3种声像图联合对痛风性关节炎的诊断特异度为95.00%,敏感度为67.50%。结论痛风性关节炎患者关节病变更易累及第一跖趾关节和踝关节,MSUS检查可以检出痛风性关节炎患者受累关节处的多种声像图特征,其中双轨征、强或高回声点、痛风石3种声像图联合诊断痛风性关节炎的特异度和敏感度均较高,且不受短期体内血尿酸水平波动的影响,对痛风性关节炎的诊断具有较高的价值。

分析新能源汽车维修中电子诊断技术要点

当前随着我国新型技术在汽车领域的不断应用,新能源汽车成为人们在选择汽车类型上的首要选择,其在汽车维修上也在采取着重要的科学技术,让新能源汽车在生活中的应用越来越便捷。文章将从新能源汽车的发展历程以及电子诊断技术在维修中的优势进行展开讨论,深入分析新能源汽车维修中电子诊断技术的应用要点,以及电子诊断技术在新能源汽车维修上当前还存在什么局限性,为我国新能源汽车在汽车维修上提出相关建议,使得我国在汽车领域的发展上更进一步。

Is the present cut-point to define type 2 diabetes appropriate in Latin-Americans?

The diagnosis of diabetes mellitus type 2(DM2) is based either on increased plasma glucose or Glycated hemoglobin levels. Since these measures are the only means for diagnosis of DM2, they must be well adapted to each population according to their metabolic characteristics, given that these may vary in each population. The World Health Organization(WHO) determined the cut-points of plasma glucose levels for the diagnosis of DM2 by associating hyperglycemia with the risk of a specific microvascular complication-retinopathy. Cardiovascular diseases are however the principal causes of mortality in patients with DM2 and we reported that in the Colombo-Ecuadorian population impaired fasting glucose and impaired glucose tolerance are both riskmarkers for myocardial infarction. We propose that the current cut-points accepted by the WHO need to be revaluated in populations such as Latin America and that there should be lower cut points for glycaemia in this population, to reduce the prevalence of cardiovascular complications associated with DM2.

Interpretation of data and treatment of Jing-well point temperatures test

The Jing-well point temperatures test method is a method to diagnose and guide the treatment of diseases by measuring the subjects' symmetrical well point temperature. it is improved from the method of knowing heat sensitivity. The application of Jing-well point temperatures test method is wide, and it can be used in internal and external gynecology and pediatrics and facial features department. at the same time, it has the advantage of objective and accurate diagnosis. The old law has some shortcomings, such as poor intuition, unavoidable omission of information, incomplete interpretation of information and so on. In this paper, Excel software is used to transform the data into line chart form, which improves the intuition and comprehensiveness of this method, so that the data can be better interpreted and used. It is newly proposed in this article that in addition to observing the longitudinal di fference of well point temperature, more attention should be paid to the horizontal contrast difference of well point temperature in different meridians. The article also summarizes a number of treatment methods, including acupuncture, moxa moxibustion, cupping and scraping, and the selection of acupoints, including mother acupoints, tenderness points and heat-sensitive moxibustion, so that doctors can combine traditional Chinese medicine professional knowledge in clinic.

模型参数点估计的可靠性:以CDM为例

心理学研究中,不恰当的模型参数估计框架或收敛准则严重影响模型参数点估计的可靠性,进而影响到研究结论的可靠性。本研究提出了基于MLE-EM的CDM模型参数估计新框架,以及新收敛判断方法。通过模拟研究与实证数据分析的方式,探索了新参数估计框架和新收敛判断方法的表现,并与已有模型参数估计框架及收敛判断方法进行了比较。结果显示,新的模型参数估计框架及收敛准则的表现优于已有的模型参数估计框架及收敛准则,能有效提高模型参数点估计的可靠性。

C肽及胰岛自身抗体在糖尿病分型诊断中的价值研究

目的探讨空腹C肽(FC-P)、餐后2小时C肽(P2hC-P)及胰岛自身抗体在糖尿病分型诊断中的价值。方法分析148例1型糖尿病(T1DM)患者与353例2型糖尿病(T2DM)患者的基本特征、实验室检查结果(包括C肽水平、胰岛自身抗体)存在的差异。根据病程将各型患者又分别分为3个亚组(0~年组、2~年组、5~年组),比较各亚组患者入院时及胰岛素强化治疗后的FC-P、P2hC-P水平差异。绘制ROC曲线分析FC-P、P2hC-P对糖尿病分型的诊断价值。结果T2DM患者年龄、病程、BMI、FC-P、P2hC-P均高于T1DM患者(均P<0.01),两组空腹血糖(FBG)、糖化血红蛋白(HbA1c)水平的差异无统计学意义(均P>0.05)。T2DM组患者谷氨酸脱羧酶抗体(GADA)、胰岛细胞抗体(ICA)、蛋白酪氨酸磷酸酶抗体(IA-2A)、锌转运蛋白8抗体(ZnT8A)均为阴性,T1DM患者GADA、ICA、胰岛素自身抗体(IAA)、IA-2A、ZnT8A的水平均显著高于T2DM患者(均P<0.01)。T2DM不同病程亚组患者的FC-P、P2hC-P水平均高于T1DM组(均P<0.05)。ROC曲线分析显示病程<2年的患者入院时检测FC-P、P2hC-P明确糖尿病分型的最佳临界值分别为0.165nmol/L、0.323nmol/L;胰岛素强化治疗后检测FC-P、P2hC-P的最佳临界值分别为0.318nmol/L、1.268nmol/L。胰岛素强化治疗后P2hC-P的AUC最大,为0.938,灵敏度为92.91%,特异度为88%,诊断准确度较高。结论C肽可作为鉴别T1DM、T2DM的指标,且餐后C肽的诊断价值高于FC-P,同时联合GADA、ZnT8A、IA-2A及年龄、BMI等临床特征可降低T1DM的临床漏诊率及误诊率。

分子诊断试剂设计开发过程的关键控制点和常见问题分析

分子诊断试剂的设计开发过程是体外诊断试剂质量管理体系的关键环节。该研究结合分子诊断体外诊断试剂的技术设计特点,分析设计开发过程中应关注的关键控制点。同时从注册质量管理体系角度出发,分析设计开发过程的常见问题,旨在为企业开展该类试剂的设计开发及注册质量管理体系建立提供技术参考,提高企业的产品研制效率,优化企业的质量管理体系,提升注册申报效率及质量。

Real-time electrical detection of epidermal skin MoS2 biosensor for point-of-care diagnostics

Various approaches have been proposed for point-of-care diagnostics, and in particular, optical detection is preferred because it is relatively simple and fast. At the same time, field-effect transistor （FET）-based biosensors have attracted great attention because they can provide highly sensitive and label-free detection. In this work we present highly sensitive, epidermal skin-type point-of-care devices with system-level integration of flexible MOS2 FET biosensors, read-out circuits, and light-emitting diode （LEDs） that enable real-time detection of prostate cancer antigens （PSA）. Regardless of the physical forms or mechanical stress conditions, our proposed high-performance MoS2 biosensors can detect a PSA concentration of 1 pg.mL-1 without specific surface treatment for anti-PSA immobilization on the MoS2 surface on which we characterize and confirm physisorption of anti-PSA using Kelvin probe force microscopy （KPFM） and tapping-mode atomic force microscopy （tm-AFM）. Furthermore, current modulation induced by the binding process was stably maintained for longer than 2-3 min. The results indicate that flexible MoS2-based FET biosensors have great potential for point-of-care diagnostics for prostate cancer as well as other biomarkers.

Integrated microfluidic devices for in vitro diagnostics at point of care

Given the continuous and growing demand for point of care(POC)diagnostic tests,attention has been shifted toward integration and miniaturization of laboratory protocols into“sample-in-answer-out”devices.Microfluidic technologies have been considered an ideal solution to address the requirements of POC diagnostics since many laboratory functions can be miniaturized and incorporated onto a single integrated chip.In this review,we summarize the advances of integrated microfluidic devices for POC diagnostics in the last 3 years.Particularly,we summarize current materials used for microfluidic chip fabrication,discuss the innovation of versatile integrated microfluidic devices,especially the strategies for simplifying sample preparation in manual or self-driven systems,and new detection methods of microfluidic chips.In addition,we describe new integrated microfluidic devices for POC diagnostics of protein-targeted immunodiagnostics,nucleic acid molecular tests,and small molecule metabolites analysis.We also provide future perspectives and current challenges for clinical translation and commercialization of these microfluidic technologies.

评价卡托普利试验诊断原发性醛固酮增多症的价值

目的:评价卡托普利试验对于原发性醛固酮增多症的诊断意义,并计算最佳诊断切点。方法:1994-06至2012-05期间解放军总医院内分泌科收治的96例综合临床表现、实验室检查及辅助检查明确诊断为原发性醛固酮增多症患者为原发性醛固酮增多症组,同时收集45例高度怀疑原发性醛固酮增多症,并经生化检查、辅助检查及功能试验检查结果排除原发性醛固酮增多症,被诊断为原发性高血压的患者为原发性高血压组。住院期间患者均行卡托普利试验,并应用受试者工作特征(ROC)曲线对卡托普利试验的醛固酮水平及试验后醛固酮与肾素水平进行评价,分析其诊断效能,并得出最佳诊断切点及对应的敏感性和特异性。结果 :卡托普利试验后1 h、2 h的醛固酮水平的ROC曲线下面积(AUC)为0.831和0.818,试验后1 h、2 h的醛固酮与肾素比值的AUC分别是0.909和0.922;试验后1 h醛固酮水平的切点为544.95 pmol/L,敏感性为70%,特异性为90.7%,试验后2 h醛固酮水平的切点为466.8 pmol/L,敏感性为69.8%;特异性为70.5%;试验后1 h醛固酮与肾素比值的切点为34.6[ng/dl:μg/(ml·h)],敏感性78.3%;特异性88.4%。试验后2 h醛固酮与肾素比值的AUC最大,该指标有较高的诊断价值,诊断切点为42.2[ng/dl:μg/(ml·h)],敏感性和特异性分别为76.7%和95.3%。结论:卡托普利试验后1 h、2 h后醛固酮水平及醛固酮与肾素的比值均对原发性醛固酮增多症有诊断价值,以卡托普利试验后2 h醛固酮与肾素比值的诊断价值最大。