Evaluation of the immunochromatographic strip test for the rapid diagnosis of antenatal syphilis in women in Eldoret,Kenya

Objective： This study compared the performance of the immunochromatographic strip （ICS） to the Venereal Disease Research Laboratory （VDRL） test and Treponema pallidum haemagglutination assay （TPHA） at a primary health care setting. Methods： The study group was comprised of 150 females randomly drawn from a population of pregnant women attending their first antenatal visit or follow-up visits at West Maternity Hospital in Eldoret Kenya, but without a previous syphilis test during that pregnancy. On-site VDRL, ICS and TPHA tests were performed and immediate treatment provided where appropriate. The performance of the three tests was compared, Results： The sero-prevalence of syphilis as determined by the VDRL test was 3%. There was no significant difference between the ICS and the VDRL test （P 〉 0.05）. The sensitivity and specificity of the ICS test were 80% and 98.6% respectively, while the negative predictive value （NPV） and positive predictive value （PPV） were both 100%. On the other hand, the sensitivity and specificity of the VDRL test were 66.7% and 99.3%, while the NPV and PPV were 80% and 98.6% respectively. The Treponema pallidum haemagglutination assay was used as a reference test and had sensitivity, specificity, NPV and PPV of 100%. Conclusion： The diagnostic accuracy of the ICS compared favorably with theVDRL gold standard. The use of the ICS in Kenya can improve the diagnosis of syphilis in health facilities both with and without laboratories and allow community health care workers to make a rapid diagnosis of the disease, and consequently make immediate therapeutic decisions.

An Immunochromatographic Strip Test for Rapid Detection of Antibodies against Porcine Circovirus Type 2

Porcine cimovirus type 2 (PCV2) infection causes huge economic losses, but no serological method is available for batch detection of field samples. The aim of the study was to develop a method for large-batch detection of PCV2 infection. Colloidal gold-labeled staphylococcal protein A (SPA) was sprayed on glass fibers to prepare a conjugate pad. The recombinant ORF2 protein of PCV2 was blotted on the test line of the nitrocellulose (NC) membrane, and pig IgG was streaked on the control line of the NC membrane. Then, the immunochromatographic strip was used for detection of antibodies against PCV2. The results show that the strip test was simple and the results could be determined within 10 min with naked eyes. The test strip was highly specific for pig serum against PCV2 and no cross-reaction with pig serum against other pathogens was observed. The test strip had close similarity with ELISA. Storage at RT for 6 months did not affect the specificity and sensitivity obviously. A total of 324 clinical pig sera were detected by both ELISA and the developed test strip, and the coincidence was 98.77%. Therefore, the developed immunochromatographic strip is specific, sensitive, stable, fast and simple, and it is suitable for on-site detection of antibodies against PCV2.

Novel ractopamine–protein carrier conjugation and its application to the lateral flow strip test for ractopamine detection in animal feed

In this work,a novel conjugate of ractopamine and bovine serum albumin(RAC–BSA)has been developed via the Mannich reaction,with a mole coupling ratio for RAC–BSA of 9:1.The proposed conjugation method provides a simple and one-step method with the use of fewer reagents compared with other conjugation methods for competitive immunoassays.RAC–BSA conjugation was used to fabricate a competitive lateral flow strip test for RAC detection in animal feed.For sample preparation,RAC was spiked in swine feed purchased from the local markets in Thailand,and methanol and running buffer at a volume ratio of 10:90 was used as extraction buffer.The procedures for sample preparation were completed within 25 min.Under optimal conditions,the limit of detection(LOD),assessed by the naked eye within 5 min,was found to be 1 ng/g.A semi-quantitative analysis was also conducted using a smart phone and computer software,with a linearity of 0.075–0.750 ng/g,calculated LOD of 0.10 ng/g,calculated limit of quantitation of 0.33 ng/g,and good correlation of 0.992.The recoveries were found in the range of 96.4%–103.7%with a relative standard deviation of 2.5%–3.6%for intra-and inter-assays.Comparison of the results obtained by the strip test with those obtained by enzyme-linked immunosorbent assay had a good agreement in terms of accuracy.Furthermore,this strip test exhibited highly specific RAC detection without cross reactivity with related compounds.Therefore,the RAC–BSA conjugation via the Mannich reaction can be accepted as a one-step and easy conjugation method and applied to the competitive lateral flow strip test.

Comparative Studies on Detection of Antibodies against Infectious Bursal Disease Virus with Test Strips and Agar Gel Immunodiffusion Method

[Objective] This study aimed to compare the detection results of antibodies against infectious bursal disease virus with test strips and agar gel immunodiffusion method. [Method] Antibodies against infectious bursal disease virus in chicken serum were detected using test strips developed in our laboratory, and the results were comparad^with that using traditional agar diffusion method. [Result] The comparative study of the two methods showed that the sensitivity of test strips was eight times over agar gel immunodiffusion; test strips showed higher detection rate in the deter- mination test of 216 clinical samples, with high specificity, easy preservation, and simple and rapid operation, thereby being more suitable for the monitoring of clinical antibodies. [Conclusion] Test strips could replace the existing serological methods, having great promotion and application value in antibody monitoring.

A dual-RPA based lateral flow strip for sensitive,on-site detection of CP4-EPSPS and Cry1Ab/Ac genes in genetically modified crops

Traditional transgenic detection methods require high test conditions and struggle to be both sensitive and efficient.In this study,a one-tube dual recombinase polymerase amplification(RPA)reaction system for CP4-EPSPS and Cry1Ab/Ac was proposed and combined with a lateral flow immunochromatographic assay,named“Dual-RPA-LFD”,to visualize the dual detection of genetically modified(GM)crops.In which,the herbicide tolerance gene CP4-EPSPS and the insect resistance gene Cry1Ab/Ac were selected as targets taking into account the current status of the most widespread application of insect resistance and herbicide tolerance traits and their stacked traits.Gradient diluted plasmids,transgenic standards,and actual samples were used as templates to conduct sensitivity,specificity,and practicality assays,respectively.The constructed method achieved the visual detection of plasmid at levels as low as 100 copies,demonstrating its high sensitivity.In addition,good applicability to transgenic samples was observed,with no cross-interference between two test lines and no influence from other genes.In conclusion,this strategy achieved the expected purpose of simultaneous detection of the two popular targets in GM crops within 20 min at 37°C in a rapid,equipmentfree field manner,providing a new alternative for rapid screening for transgenic assays in the field.

Strip loading test theory and equipment development

One of the important issues for geotechnical engineers is the characterization of soil properties such as cohesion and internal friction angle by means of soil testing. A new experimental method of soil characterization based on the surface displacement of strip loaded soils is proposed. The theory to relate the soil deformation/displacement to soil strength properties is presented and compared with a series of conventional soil characterization techniques with direct shear tests. The proposed/developed strip loading tests provide reasonably accurate results compared with traditional direct shear tests. The new strip loading physical simulation and testing devices are helpful for understanding soil strength concepts and also provide an effective bridge connecting with engineering mechanics and foundation engineering courses instructions wherein derivation of bearing capacity theory equations is based on the same MohrCoulomb soil strength parameters. The advantages, limitations, and use of the strip loading modeling/testing technique in engineering education and further more in depth researches are discussed in the concluding remarks part.

''Blue Dream Pregnancy Test Strip''For Detecting Early Pregnancy

＇＇ＢｌｕｅＤｒｅａｍＰｒｅｇｎａｎｃｙＴｅｓｔＳｔｒｉｐ＇＇ＦｏｒＤｅｔｅｃｔｉｎｇＥａｒｌｙＰｒｅｇｎａｎｃｙ￥／／ＳｅｒｖｉｎｇｔｈｅＩｍｐｒｏｖｅｍｅｎｔｏｆＲｅｐｒｏｄｕｃｔｉｖｅＨｅａｌｔｈｏｆＷｏｍｅｎＡｎｄｔｈｅＨａｐｐｉｎｅｓｓｏｆ...

Determination of the Friction Coefficient in the Flat Strip Drawing Test

Current work is focused on the influence of friction in deep drawing process. Friction measurements were also conducted using a modified tribotester based on strip sliding between tools. Four different tool surfaces were tested under similar contact conditions regarding contact area, normal pressure, sliding speed, lubricant and surface characteristics to calculate the friction coefficient between the tool surface and a high strength low alloy steel sheet HSLA 380. The results showed that friction coefficient varies over a wide range with different lubricating conditions and different sliding velocities. For some sliding velocities, the coefficient of friction is stable and low, while for others it is unstable and higher. Results of the experiments reveal that this novel tribotester is a very useful tool to evaluate and compare the friction between steel sheet and tool surfaces in alloyed steel for cold working applications. The outcomes have only small dispersion within the different test series, which indicates a stable process with good repeatability. The test method enables comparison of different surface finishes and treatments, lubricants and coatings in terms of friction and galling under conditions similar to those found in sheet metal forming processes. The four different types of surfaces considered for this study were grinded, polished, nitrided and quenched/tempered. The main difference among the tested tools in this work was the surface roughness, which was found to have a strong influence on friction.

Seismic responses of the steel-strip reinforced soil retaining wall with full-height rigid facing from shaking table test

To investigate the seismic response of the steel-strip reinforced soil retaining wall with fullheight rigid facing in terms of the acceleration in the backfill, dynamic earth pressure in the backfill, the displacements on the facing and the dynamic reinforcement strain distribution under different peak acceleration, a large 1-g shaking table test was performed on a reduced-scale reinforced-earth retaining wall model. It was observed that the acceleration response in non-strip region is greater than that in potential fracture region which is similar with the stability region under small earthquake,while the acceleration response in potential fracture region is greater than that in stability region in middle-upper of the wall under moderately strong earthquakes. The potential failure model of the rigid wall is rotating around the wall toe. It also was discovered that the Fourier spectra produced by the inputting white noises after seismic wave presents double peaks, rather than original single peak, and the frequency of the second peak trends to increase with increasing the PGA(peak ground amplitude) of the excitation which is greater than 0.4 g. Additionally,the non-liner distribution of strip strain along the strips was observed, and the distribution trend was not constant in different row. Soil pressure peak value in stability region is larger than that in potential fracture region. The wall was effective under 0.1 g-0.3 g seismic wave according to the analyses of the facing displacement and relative density. Also, it was discovered that the potential failure surface is corresponds to that in design code, but the area is larger. The results from the study can provide guidance for a more rational design of reinforced earth retaining walls with full-height rigid facing in the earthquake zone.

Testing of Anti-stripping Property of Friction Spun Core Yarn

Friction spun core yarn has two components: filament core and staple fiber sheath. Under axial rubbing action, the failure mode of the core yarn is the stripping of the sheath from the core. This paper introduces a method to test the anti - stripping property of the core yarn. With a modified Universal Testing Machine, the stripping resistance of friction spun core yarn can be continuously measured. Some factors Influencing the measurements are discussed in detail. The testing results are compared with those from a Y731 Yarn Abrasion Tester and fur - ther confirmed by weaving practice.

E-test试条对异质性耐万古霉素葡萄球菌的检测

目的 探讨E test对异质性耐万古霉素葡萄球菌的检测价值。方法 从连续接触万古霉素的脑心浸液琼脂 (BHIA)平板上挑取万古霉素异质性耐药葡萄球菌菌株 ,应用万古霉素E test试条、药敏纸片和琼脂平板对倍稀释法测定药敏结果。结果 E test检测的对万古霉素异质性耐药葡萄球菌MRSH10 9,MRSH2 ,MRSH13 ,MRSH 3 1,MRSH 60 ,MRSH 10 8,MRSA73 ,MRSA97,MRSA10 2的MIC依次为 :16、2 4、48、48、16、3 2、2 4、2 4mg/L ,其中耐药 7株占 77 8% ( 7/9) ,中介 2株占 2 2 2 % ( 2 /9) ;琼脂对倍稀释法的MIC为 :16、3 2、64、3 2、16、3 2、3 2、16、3 2mg/L ,耐药 6株占 66 7% ( 6/9) ,中介 3株占 3 3 3 % ( 3 /9) ;药敏纸片直径依次为 :14、12、10、11、10、15、13、10 ,13mm ,敏感率为 11 1% ( 1/9)。结论 E test可以便捷直观地鉴定对万古霉素异质性耐药葡萄球菌的药敏结果 ,与琼脂平板对倍稀释法接近 ,优于纸片法。

Evaluation of Abuse Drugs and Clinical Laboratory Tests Variations in Whole Blood ＆ Urine Samples of Abusers

In this study, five hundred urine samples and five hundred blood samples of abusers were examined for the presence of alkaloid substances and abuse drugs in urines and bloods. These numbers of blood and urine samples of addicts in clinics of welfare organization, during detoxification treatment or maintenance treatment were screened for abuse drugs presence. The all of samples were tested through as a view of clinical laboratory methods. Age ranges of female patients were 35 ~ 15 and age range of males patients were 45 ~ 15. All patients filled questionnaire and satisfy forms too. First, all fresh urine and blood samples were examined to confirm presence drugs abuses, depend on their addiction and treatment, so all samples were confirmed by two tests. Then they were examined to other clinical laboratory tests. All data were analyzed by t-test and were Anova one way and two ways of Anova Turkey, and p 〈 0.05 was considered significant. The p-value of this study was p = 0.0001. The results of this study were showed that 4% of abusers had mild increase in hematocrite level and 2% of narcotic drugs abusers had mild lower level of blood sugars than normal range and 4% of participants had increase liver enzymes such ALT （alanine transferase）, AST （aspartat transferase）, ALP （alkaline phosphatease） and 1% of them had renal failure. Although blood level BUN （blood urea nitrogen） and creatinin were examined to evaluation of their renal failure .The results in Tabriz/Iran undrevision of welfare organization clinics were approximately showed that positive results of addiction are in each of urine and blood samples. Because some of abusers directly consumed full long time agonist or partial agonists＇ drugs such as methadone and buprenorphine for their maintenance therapy in clinics. Also doing test on blood samples has high importance in distinguishing and confirmation of drugs abuse in samples. Also in this study we conclude that among all drug analytical methods the cheapest and easiest test to screening opioids and other abuse drugs in urine and blood samples is strip test for rapid diagnosis, also tests on blood samples have high importance as a view point of accuracy to distinguishing of drugs abuse, and serum levels of some other parameters showed all abusers patients situation such as liver and renal dysfimction through clinical laboratory tests.

柔性条式疏花执行装置试验研究

疏花可以调整果树负载量,是影响果树产量和质量的重要因素。为研究机械疏花效果及其影响因素,采用自主研发的柔性条式疏花机执行装置对桃花进行试验,选取橡胶和尼龙两种材料的疏花条,以疏花条轴向间距、疏花条列数、主轴转速、工作模式为试验因素,以疏花指数来评价疏花效果,并优化了装置的工作参数。结果表明:若采用尼龙疏花,疏花轴转速为400 r/min、疏花条列数为4、工作模式为冠内垂直、疏花条轴向间距为5 cm时效果最优;若采用胶条疏花,疏花轴转速为450 r/min、疏花条列数为4、工作模式为冠外平行、疏花条轴向间距为4 cm时效果最优。经试验验证,设计满足疏花的工作要求,为柔性条式疏花机的研发提供了理论依据。

Multistix^(TM)10SG试纸条与Combur10Test^RM试纸条临床应用结果比较

目的 :比较MultistixTM10SG与Combur 10TestRM两种试纸条临床测定结果 ,评价其应用价值。方法 :按C1initek - 5 0 0型及Miditron -M尿干化学分析仪及试纸条使用说明书上进行。结果 :浓度接近两种试纸条同一量级比较 ,完全符合率 :>96 %有G1u、BIL、Ket、UBG、Nit5项 ,达到 91%有Pro 1项 ,达到 70 %以上有BLO、Leu 2项 ,最低SG为 4 4 .8% ,pH为 4 2 .6 %。结论 :两种试纸条各具特点 ,质量稳定 ,均适合临床应用。MultistixTM10SG试纸条各测试块检测化学成分浓度阳性程度的量级分配更加合理 ,为尿干化学法首选试纸条。

抗丁香酚单克隆抗体的研制及胶体金试纸条检测方法的建立

为制备高特异性和高灵敏度的抗丁香酚(Eugenol)单克隆抗体,建立检测丁香酚的胶体金免疫层析法,本研究采用亲核取代法合成丁香酚半抗原(Eugenol-COOH)并进行质谱(HRMS)鉴定;采用碳二亚胺法制备丁香酚免疫抗原(Eugenol-BSA)和包被抗原(Eugenol-OVA),进行十二烷基硫酸钠-聚丙烯酰胺凝胶电泳(SDS-PAGE)和紫外扫描鉴定;利用免疫抗原Eugenol-BSA免疫小鼠,经细胞融合、筛选和克隆,最终得到1株能稳定分泌抗丁香酚单克隆抗体的杂交瘤细胞株(3D9),并准备腹水,利用间接竞争ELISA(icELISA)方法测定腹水效价;对获得的单克隆抗体进行鉴定,经条件优化建立胶体金免疫层析试纸条检测方法,对试纸条的灵敏度和稳定性进行评价。结果表明,Eugenol-BSA偶联比约为16∶1,Eugenol-OVA偶联比约为10∶1,完全抗原偶联成功;3D9细胞株的抗体类型及亚类均为免疫球蛋白G(IgG1),轻链为κ链;单克隆抗体效价达1×10^(-6);丁香酚浓度与抑制率之间的线性回归方程为y=9.671lnx+10.539(R^(2)=0.998),半数抑制浓度(IC_(50))为59.2 ng·mL^(-1),表明制备的抗丁香酚单克隆抗体具有较高的检测灵敏度。所制备的胶体金免疫试纸条优化参数为:胶体金标记最适pH值9、0.2 mol·L^(-1)K2CO3添加量12μL、抗体最佳标记量7μg·mL^(-1)、胶体金试纸条的T线消失浓度1.8μg·mL^(-1),该参数下的裸眼检出限0.3μg·mL^(-1)。本研究可为丁香酚的现场检测提供有效方法。

Rapid testing methods for food contaminants and toxicants

Food safety is one of the major concerns in every country regardless of the economic and social development. The frequent occurrence of food scandals in the world has led the Chinese government to implement several strategies to fortify the food supply system to a high food safety standard. This relies heavily on laboratory testing services but conventional methods for detection of food contaminants and toxicants are limited by sophisticated sample preparation procedures, long analysis time, large instruments and professional personnel to meet the increasing demands. In this review, we have incorporated most of the current and potential rapid detection methods for many notorious food contaminants and toxicants including microbial agents, toxic ions, pesticides, veterinary drugs and preservatives, as well as detection of genetically modified food genes and adulterated edible oil. Development of rapid, accurate, easy-to-use and affordable testing methods could urge food handlers and the public to actively screen for food contaminants and toxicants instead of passively relying on monitoring by the government examination facility. This review also provides several recommendations including how to encourage the public to engage in the food safety management system and provide optimal education and financial assistance that may improve the current Chinese food safety control system.

Excitation and Detection of Shear Horizontal Waves with Electromagnetic Acoustic Transducers for Nondestructive Testing of Plates

The fundamental shear horizontal（SH0） wave has several unique features that are attractive for long-range nondestructive testing（NDT）. By a careful design of the geometric configuration, electromagnetic acoustic transducers（EMATs） have the capability to generate a wide range of guided wave modes, such as Lamb waves and shear-horizontal（SH） waves in plates. However, the performance of EMATs is influenced by their parameters. To evaluate the performance of periodic permanent magnet（PPM） EMATs, a distributed-line-source model is developed to calculate the angular acoustic field cross-section in the far-field. Numerical analysis is conducted to investigate the performance of such EMATs with different geometric parameters, such as period and number of magnet arrays, and inner and outer coil widths. Such parameters have a great influence on the directivity of the generated SH0 waves that arises mainly in the amplitude and width of both main and side lobes. According to the numerical analysis, these parameters are optimized to obtain better directivity. Optimized PPM EMATs are designed and used for NDT of strip plates. Experimental results show that the lateral boundary of the strip plate has no perceivable influence on SHO-wave propagation, thus validating their used in NDT. The proposed model predicts the radiation pattern ofPPM EMATs, and can be used for their parameter optimization.

Plasma discharge characteristics of segmented diverter strips subject to lightning strike

In order to research segmented diverters for aircraft lightning protection, a transient 2 D multiphysics model based on magnetohydrodynamics theory is proposed to predict the location of the arc plasma discharge and lightning channel, and to simulate the electrothermal behavior.Based on numerical calculation and preliminary analysis, factors that affect the breakdown voltage of the segmented diverter are discussed. The results show that the voltage increase rate of the voltage source, the width of the air gap between metal segments and the geometry of these segments influence the breakdown voltage of the strip. High-voltage tests of the segmented diverter are performed to reveal air breakdown of the strip and redirect the lightning current.Experimental and numerical results are compared to verify the correctness of the numerical model. The ionization of the air gap between metal segments and the breakdown voltage of the strip calculated by the model are qualitatively consistent with experimental results. The breakdown voltage of the segmented diverter is far lower than the lightning voltage. When a lightning strike occurs, the segmented diverter can be quickly ionized to form a plasma channel which can guide the lightning current well.

水产品中甲醛快速显色试纸的构筑与应用

为实现水产品中甲醛含量的现场快速检测,本研究基于溶胶-凝胶法将高碘酸钾、乙二胺四乙酸二钠(EDTA-2Na)构筑于滤纸表面,制得纳米显色前体物;利用4-氨基-3-联氨-5-巯基-1,2,4-三氮杂茂(AHMT)甲醛显色反应原理,使甲醛与AHMT在纳米显色前体物表面富集缩合并经高碘酸钾氧化,最终形成蓝紫色纳米显色复合物;通过自行开发的SHotPic 1.0软件分析试纸显色程度,快速得到待测水产品中的甲醛含量。结果表明,甲醛含量与试纸显色深浅呈线性关系,相关系数达0.9719;纳米显色复合物在底物富集效应及纳米限域效应共同作用下显色蓝移并加深;试纸显色后经软件半定量可快速检测样品中甲醛含量,最低检出限为0.34 mg·kg^(-1)。本研究可为新型纳米显色剂开发和食品中有害化合物的快速直读显色分析提供理论指导和实践参考。

Wear analysis of a side dam in twin-roll strip casting

Reducing wear on a side dam can prolong the casting operation life of a twin-roll strip casting process,thus reducing production cost and improving casting stability.To lengthen the service life of the side dam,it is necessary to understand the wear performance of the side dam material.To investigate the wear behavior mechanism of the side dam,in this study,the UMT-2 friction and wear tester was used to determine the relationship between the wear rate of the side-dam material and various parameters.Based on the roughness of the contact area between the side dam and the end of the casting rolls as well as on the amount of deformation of the side dam,which was derived using a thermal-deformation simulation model,the reasons for the uneven wear of the side dam were obtained.