Microfluidic fluorescent platform for rapid and visual detection of veterinary drugs

The overuse of veterinary drugs and veterinary drug residues is increasingly becoming an obstacle to sustainable development worldwide. It is therefore imperative to establish a quantitative, sensitive and efficient method for the detection of veterinary drugs. Herein, we developed a visual microfluidic detection platform for rapid and sensitive detection of veterinary drugs using CdTe quantum dots (QDs) with three different ligands as the sensing units. Green-emissive 3-mercaptopropionic acid (MPA)-CdTe QDs, yellow-emissive thioglycolic acid (TGA)-CdTe QDs and orange-emissive N-acetyl-l-cysteine (NAC)-CdTe QDs were synthesized by a sulfhydryl aqueous phase method. These CdTe QDs show selective rapid fluorescence response to pefloxacin (PEF), malachite green (MG), and 1-aminohydantoin hydrochloride (AHD). With the concentration of veterinary drugs increasing, the CdTe QDs reveals a fluorescence color variation from bright to dark until quenched and the response degree of CdTe QDs with different ligands to veterinary drugs is different. Specifically, the limits of detection (LODs) of MPA-CdTe, TGA-CdTe and NAC-CdTe QDs probes for PEF were 7.57 μM, 1.75 μM and 2.90 μM, respectively, and the response was complete in a few seconds, realizing the sensitive and rapid detection of PEF. The three kinds of CdTe QDs could also be used in the detection of other veterinary drugs such as MG and AHD. Finally, a microfluidic detection platform was constructed for visual sensing and rapid detection towards veterinary drugs. The sensor platform holds the advantages of simple operation, low cost, rapid sensing and good sensitivity, and is potentially useful for visual quantitative detection of veterinary drug residues in aquatic products and the environment.

A visual microfluidic fluorescent detection platform based on multicolor quantum dots with multiple capping ligands is developed for rapid and sensitive detection of veterinary drugs.     

Metabolic biotinylation provides a unique platform for the purification and targeting of multiple AAV vector serotypes.

The development of rationally designed targeted gene delivery vectors is an important focus for gene therapy. While genetic modification of AAV can produce vectors with modified tropism, incorporation of targeting peptides into the structural context of the AAV virion often results in loss of function or loss of virion integrity. To address this issue, we have developed a targeting system using metabolically biotinylated AAV. We generated serotype 1, 2, 3, 4, and 5 AAV capsids with small peptide insertions that are metabolically biotinylated in packaging cells during vector production by coexpression of the Escherichia coli BirA, biotin ligase, gene. Biotin moieties are exposed on the surface of assembled AAV particles and can interact with avidin. Metabolically biotinylated AAV vectors produced in this manner maintained endogenous titer and tissue tropism, could be purified on monomeric avidin resin, and could be retargeted to cells engineered to express an artificial avidin-biotin receptor. This technology provides not only a single platform for the purification of multiple AAV vector serotypes, but also a means for the development of multiple targeted AAV vectors utilizing a single capsid modification via straightforward avidin-biotin ligand coupling.     

A prototype power assist wheelchair that provides for obstacle detection and avoidance for those with visual impairments

Background

The cervical muscles are considered a potential site of whiplash injury, and there are many impact scenarios for whiplash injury. There is a need to understand the cervical muscle response under non-conventional whiplash impact scenarios, including variable head position and impact direction.

Methods

Twenty healthy volunteers underwent right anterolateral impacts of 4.0, 7.6, 10.7, and 13.0 m/s² peak acceleration, each with the head rotated to the left, then the head rotated to the right in a random order of impact severities. Bilateral electromyograms of the sternocleidomastoids, trapezii, and splenii capitis following impact were measured.

Results

At a peak acceleration of 13.0 m/s², with the head rotated to the right, the right trapezius generated 61% of its maximal voluntary contraction electromyogram (MVC EMG), while all other muscles generated 31% or less of this variable (31% for the left trapezius, 13% for the right spleinus. capitis, and 16% for the left splenius capitis). The sternocleidomastoids muscles also tended to show an asymmetric EMG response, with the left sternocleidomastoid (the one responsible for head rotation to the right) generating a higher percentage (26%) of its MVC EMG than the left sternocleidomastoid (4%) (p < 0.05). When the head is rotated to the left, under these same conditions, the results are reversed even though the impact direction remains right anterolateral.

Conclusion

The EMG response to a right anterolateral impact is highly dependent on the head position. The sternocleidomastoid responsible for the direction of head rotation and the trapezius ipsilateral to the direction of head rotation generate the most EMG activity.     

Urinary-based ovulation and pregnancy: point-of-care testing

OBJECTIVE: To review the literature concerning ovulation prediction devices and pregnancy detection tests for home use. DATA SOURCES: Articles were identified through searches of the MEDLINE (1966-May 2003), EMBASE (1980-May 2003), and International Pharmaceutical Abstracts (1970-May 2003) databases using the key words ovulation, ovulation detection, pregnancy test, diagnostic reagent kit, and diagnostic test. Additional references were located through review of the bibliographies of the articles found in the literature search. Searches were not limited by time restriction, language, or use of human or animal subjects. STUDY SELECTION AND DATA EXTRACTION: Review articles, textbook chapters, and experimental and observational studies on home use ovulation and pregnancy tests were selected. DATA SYNTHESIS: Luteinizing hormone (LH)-based ovulation tests have demonstrated accurate and superior ovulation detection when compared to basal body temperature charting, calendar calculation, salivary ferning, or observation of vaginal or cervical discharge changes. Systems using LH and estrone-3-glucuronide (E3G) have also demonstrated accurate detection of the fertile period. Literature evaluating home use of pregnancy tests has demonstrated accurate use by lay persons. CONCLUSIONS: Urinary-based ovulation prediction and pregnancy detection tests available for use by nonprofessionals enable women and couples to take an active role in the family planning process. Numerous products are available at reasonable costs to the consumer.     

一次性两用输液器的设计及应用

一次性输液器的广泛应用 ,给临床治疗带来了许多方便 ,但也存在不足 ,如不利于急诊、手术室因病人病情突变随时调整输注液体的种类、量和某些药物 ;对儿科患儿静脉输注液体需要量的调整也很不方便。为此 ,对一次性输液器进行了如下改进。1　设计　　在一次性输液器穿刺瓶塞的粗针头针栓处设置一个长3ｃｍ、直径 0 .6ｃｍ的弹性连接套管 (乳胶管 ) ,使其可与密闭瓶或软包装液体袋连接 ,也可与开放式输液瓶连接。详见图 1。2　应用　　需要使用原装密闭瓶或软包装液体时 ,打开一次性两用输液器 ,轻轻撕去穿刺瓶塞粗针头上的连接套管 ,按密闭式…     

Cardiac biomarkers and the case for point-of-care testing

Cardiovascular disease (CVD) is the single greatest cause of adult mortality in the western world and, consequently, places a massive burden on healthcare services and the economy. Lifestyles, lack of clearly defined risk assessment criteria, consistently high incidences of misdiagnosis and inappropriate referrals, all contribute significantly to this problem. It also correlates directly with inefficient or non-accessible early detection systems. Over the last decade much research has focused on the identification of cardiac biomarkers that can be used for the detection of cardiac distress and that add value to current risk stratification criteria. An exposition of some of the most consistently cited biomarkers is provided and their current status and potential value as early CVD risk predictors, more accurate diagnostic markers of acute myocardial damage and as reliable prognostic indicators, is evaluated. The particular importance of early prediction and the integral role that point-of-care (POC) testing is expected to play in the future of cardiac care is critically discussed.     

Novel diagnostics for point-of-care bacterial detection and identification

In addition to limiting the effectiveness of antimicrobial agents, antimicrobial resistance (AMR) is a significant global health concern as it is responsible for significant mortality/morbidity and increased economic burdens on healthcare systems. Diagnostic tests have been suggested as a means of prolonging the effectiveness of current antimicrobials; culture and other conventional diagnostics are hindered in their practicality as they are time- and labour intensive to perform. Point-of-care (POC) testing is performed near where the patient is being treated and can provide timely results that allow evidence based clinical interventions to be made. This review aims to outline the chemical principles behind some novel and emerging diagnostic techniques which have the required speed, simplicity, effectiveness and low-cost for incorporation into POC devices which can be used to inform and optimize antimicrobial use.

The WHO global action plan on antimicrobial resistance outlines the need for new diagnostic tools. Point-of-care testing for bacterial infections would enable clinically meaningful interventions using methods that are rapid, low-cost, easy-to-operate, and portable.     

一次性简易加药器的研制和应用

目前,在临床上溶解粉剂药物其程序繁琐、效率低、劳动强度大,反复抽吸、穿刺,增加污染环节[1],费时费力。为解决上述诸多问题,根据临床实际需要,研制出一次性简易加药器(下称加药器)。经反复试验,效果满意,现介绍如下:1　结构一次性简易加药器全长60ｃｍ,包括封尖多孔式针头、开关夹、排气管和主体管四部分。另外附设台式加药架。加药器为单腔多头式。1.1　封尖多孔式针头:针尖封闭,侧面开孔且连有排气管,终端有过滤器,单头一端直径同输液器,多头一端略短,约0.8ｃｍ,直径约0.3ｃｍ。1.2　主体管用聚乙烯塑料制成,直径约1ｃｍ。开关夹位于近…     

Medical and economic outcomes of point-of-care testing.

Point-of-care testing is concerned with the immediacy of response, primarily because of the need to act in a life-threatening crisis or to provide counsel in the ongoing management of a chronic disease. There are both clinical, operational and economic benefits that can accrue from this testing modality which may be observed from several perspectives--the patient, the clinician, the healthcare provider, the healthcare purchaser and society. Thus point-of-care testing can improve the management of chronic diseases such as diabetes, compromised coagulation status and epilepsy--both in terms of optimisation of, and compliance with, therapy. There are also life-threatening crises that can be averted by rapid provision of test results. Each of these scenarios can lead to more efficient use of healthcare resources.     

Current and emerging trends in point-of-care urinalysis tests

ABSTRACT

Introduction: The development of point-of-care testing (POCT) has made clinical diagnostics available, affordable, rapid, and easy to use since the 1990s.The significance of this platform rests on its potential to empower patients to monitor their own health status more frequently, in the convenience of their home, so that diseases can be diagnosed at the earliest possible time-point. Recent advances have expanded traditional formats such as qualitative or semi-quantitative dipsticks and lateral flow immunoassays to newer platforms such as microfluidics and paper-based assays where signals can be measured quantitatively using handheld devices.

Areas covered: This review discusses: (1) working principles and operating mechanisms of both existing and emerging POCT platforms, (2) urine analytes measured using POCT in comparison to the laboratory or clinical ‘gold standard,’ and (3) limitations of existing POCT and expectations of emerging POCT in urinalysis.

Expert opinion: Currently, a variety of biological samples such as urine, saliva, serum, plasma, and other fluids can be applied to POCT for quick diagnosis, especially in resource-limited settings. Emerging platforms will increasingly empower individuals to monitor their health status through frequent urine analysis even from their homes. The impact of these emerging technologies on healthcare is likely to be transformative.     

一次性可调吸氧装置的研制及应用

在临床护理实践中发现,现用的一次性吸氧装置有引起鼻粘膜损伤出血、胶布粘贴皮肤不适等,不适于长期吸氧及胶布过敏病人。为此,我院在1998年研制出一次性分流式鼻塞吸氧装置,经临床应用,受到了病人的普遍欢迎和认可。1　制作方法使用医用聚氯乙烯材料一次压模成型。鼻塞为多气孔分流式鼻塞,规格与一般鼻塞相同,鼻塞支架后方设有可调性弹性吊钩。见图1。2　使用方法使用时先调节好氧流量,吸氧管道连接鼻塞支架,用戴眼镜　　　1—导气管;　　2—固定架;　　3—分流鼻塞;　　　4—弹性吊钩;　　5—拉开的弹性吊钩图1　一次性可调吸氧装置示意图…     

改良一次性输液器临床应用观察

静脉输液时 ,经常遇到针头刺入血管而不见回血现象 ,仅凭着经验和手感判断针头是否在血管内 ,具有一定的盲目性。1999年 12月— 2 0 0 0年 10月 ,作者对一次性输液器上的调节器位置进行了改进 ,并观察穿刺时回血情况。现将应用情况总结如下 :1　临床资料1.1　一般资料　血液科 1999年 12月— 2 0 0 0年 10月收治病人2 0 0例 ,将其随机分为观察组和对照组 ,两组病人在性别、年龄、病程、临床表现以及血管充盈方面 ,经统计学处理均无统计学意义 (Ｐ >0 .0 5 )。1.2　方法　以手背浅静脉为穿刺点 ,观察穿刺时一次性输液器不同部位夹闭后的回血…     

Comparison of ACT point-of-care measurements: repeatability and agreement

BACKGROUND: Accurate control of heparin anticoagulation is necessary during all stages of cardiopulmonary bypass (CPB). The activated clotting time, first described by Hattersley in 1966, is mostly used for determination of anticoagulation. Either celite or kaolin are used as activators. An ACT value of 480 sec is proposed to be the safe minimum level for anticoagulation during CPB. This study was designed to determine if the activated coagulation time (ACT) values of each analyser separately are repeatable, and to determine whether there exists a significant difference in ACT values measured by three different analysers: the GEM PCL (Instrumentation Laboratory), the Hemochron 801 (International Technidyne Corporation) and the ACT II Automated Coagulation Timer (Medtronic). METHODS: All patients underwent cardiovascular surgical procedures requiring heparinisation (200-300 IU/kg). Blood samples for the measurement of the ACT were taken from all patients before and after heparinisation, during CPB, and after protamine administration. All samples were measured in duplicate with the three different analysers. To compare the activated clotting time data, the method described by Bland and Altman was used. The Pearson correlation coefficient was used to determine whether the differences were related to the average ACTs. p-Values <0.05 were considered statistically significant. RESULTS: The results showed that the three tested ACT analysers met the requirements of repeatability. The mean differences and standard deviations of the ACT values measured with the GEM PCL, the Hemochron 801, and the ACT II analyser were, respectively, -8.78 +/- 37.61, -19.77 +/- 68.82, and -6.23 +/- 39.21, with p-values=0.177, 0.081 and 0.384, respectively. The Pearson correlation coefficients were too low (-0.012, -0.221 and -0.241, respectively) to show any correlation between the differences and the means. The ACT values measured with the Hemochron 801 were not significantly different from the ACT values measured with the ACT II analyser: deltaACT =-34.09 +/- 146.68, with p=0.132. However, the GEM PCL did not agree with the Hemochron 801: deltaACT= -80.2 +/- 143.06, with p=0.001, or the ACT II analyser: deltaACT= -119.13 +/- 138.51, with p<0.001. A rather strong correlation was evident between the differences and the means measured with the GEM PCL compared with the Hemochron 801 (r=0.68) and the ACT II analyser (r=0.76). CONCLUSIONS: All analysers used celite or kaolin as activator. However, it was evident that the ACT measurements depended also on the analyser that had been chosen. A precaution that ACT values could not always be interpreted in the same way seems to be necessary.