长、短链探针以链延伸反应提高基因传感器检测MRSA灵敏度的实验研究

目的：利用链延伸反应的原理延长引物链以提高石英谐振式基因传感器表面的质量负载，从而提高传感器检测MRSA的灵敏度。方法：以不对称PCR的反应产物做为长链探针，人工合成的寡核苷酸片段为短链探针，在基因传感器阵列表面分别固定上金黄色葡萄球菌mecA和femA的长链及短链探针共4种探针片段，与相应的靶序列杂交后，加入Klenow酶，37℃进行链延伸反应1h。结果：长、短链探针均有效地固定了传感器表面。mecA,femA短链探针在链延伸反应前的检测灵敏度为0.5nmol/L，但经链延伸反应后检测灵敏提高到了0.05nmol/L；而长链探针却无法与相应的基因组靶序列发生杂交。结论：短链探针链延伸反应有效地提高了石英谐振式基因传感器的灵敏度，但该法不适用于链探针。     

Early diagnosis of frailty: Technological and non-intrusive devices for clinical detection

This work analyses different concepts for frailty diagnosis based on affordable standard technology such as smartphones or wearable devices. The goal is to provide ideas that go beyond classical diagnostic tools such as magnetic resonance imaging or tomography, thus changing the paradigm; enabling the detection of frailty without expensive facilities, in an ecological way for both patients and medical staff and even with continuous monitoring. Fried's five-point phenotype model of frailty along with a model based on trials and several classical physical tests were used for device classification. This work provides a starting point for future researchers who will have to try to bridge the gap separating elderly people from technology and medical tests in order to provide feasible, accurate and affordable tools for frailty monitoring for a wide range of users.     

Lower limb joint-specific contributions to standing postural sway in persons with unilateral lower limb loss

BackgroundIndividuals with lower limb loss are at an increased risk for falls, likely due to impaired balance control. Standing balance is typically explained by double- or single-inverted pendulum models of the hip and/or ankle, neglecting the knee joint. However, recent work suggests knee joint motion contributes toward stabilizing center-of-mass kinematics during standing balance.Research QuestionTo what extent do hip, knee, and ankle joint motions contribute to postural sway in standing among individuals with lower limb loss?MethodsForty-two individuals (25 m/17f) with unilateral lower limb loss (30 transtibial, 12 transfemoral) stood quietly with eyes open and eyes closed, for 30 s each, while wearing accelerometers on the pelvis, thigh, shank, and foot. Triaxial inertial measurement units were transformed to inertial anterior-posterior components and sway parameters were computed: ellipse area, root-mean-square, and jerk. A state-space model with a Kalman filter calculated hip, knee, and ankle joint flexion-extension angles and ranges of motion. Multiple linear regression predicted postural sway parameters from intact limb joint ranges of motion, with BMI as a covariate (p < 0.05).ResultsWith eyes open, intact limb hip flexion predicted larger sway ellipse area, whereas hip flexion and knee extension predicted larger sway root-mean-square, and hip flexion, knee extension, and ankle plantarflexion predicted larger sway jerk. With eyes closed, intact limb hip flexion remained the predictor of sway ellipse area; no other joint motions influenced sway parameters in this condition.SignificanceHip, knee, and ankle motions influence postural sway during standing balance among individuals with lower limb loss. Specifically, increasing intact-side hip flexion, knee extension, and ankle plantarflexion motion increased postural sway. With vision removed, a re-weighting of lower limb joint sensory mechanisms may control postural sway, such that increasing sway may be regulated by proximal coordination strategies and vestibular responses, with implications for fall risk.     

Applications of biosynthesized metallic nanoparticles – A review

We present a comprehensive review of the applications of biosynthesized metallic nanoparticles (NPs). The biosynthesis of metallic NPs is the subject of a number of recent reviews, which focus on the various “bottom-up” biofabrication methods and characterization of the final products. Numerous applications exploit the advantages of biosynthesis over chemical or physical NP syntheses, including lower capital and operating expenses, reduced environmental impacts, and superior biocompatibility and stability of the NP products. The key applications reviewed here include biomedical applications, especially antimicrobial applications, but also imaging applications, catalytic applications such as reduction of environmental contaminants, and electrochemical applications including sensing. The discussion of each application is augmented with a critical review of the potential for continued development.     

Metal-ion sensing by surface plasmon resonance on film electrodes

Dithizone and its dicarboxylic acid derivative (DDz) have been immobilised onto gold films by both chemical attachment and incorporation into spin-coated polymer films. The modified gold films were characterised by ellipsometry. Surface plasmon resonance (SPR) was employed to monitor changes in the optical properties of the dithizone films in the presence of aqueous transition metal ions. The dependence of applied potential on the SPR response in the presence of metal ions has been studied in situ. It is shown that the technique can be used for the determination of metal ions in water.     

New sensor technologies in quality evaluation of Chinese materia medica: 2010–2015

New sensor technologies play an important role in quality evaluation of Chinese materia medica (CMM) and include near-infrared spectroscopy, chemical imaging, electronic nose and electronic tongue. This review on quality evaluation of CMM and the application of the new sensors in this assessment is based on studies from 2010 to 2015, with prospects and opportunities for future research.     

骨组织细胞传递生物力学刺激的信号通路的研究进展

已有大量研究表明生物力学刺激对骨形成,骨改建起重要作用。成骨细胞、破骨细胞以及骨细胞通过各类感受器例如整合素、黏着斑、钙黏着蛋白等可以接受外界的生物力学刺激,接着激活下游不同的信号通路如MAPK通路、β-catenin通路、G蛋白通路等,并将信号进行传导,由此影响骨组织的生长、代谢。本篇综述将对骨细胞内传递生物力学刺激的信号通路做进展汇总。     

Design optimisation of planar electrolytic conductivity sensors

Planar conductivity sensors are the subject of increasing interest as basic transducers for biosensors. The high degree of control of the performance characteristics undoubtedly forms an important argument in favour of conductivity-based sensing. The paper provides an outline of the design rules to be followed if an optimal design of a planar conductivity cell is required. Based on a simplified model, it is shown that the required accuracy establishes a lower limit to the overall sensor dimensions. This lower limit is expressed as a minimum longitudinal path length necessary to obtain the desired accuracy. Given an available area, the optimum ratio of electrode-width over inter-electrode spacing for a basic two-electrode structure is shown to be close to unity. Furthermore, it is shown that the decomposition of the two electrodes into an interdigitated structure decreases the accuracy of the device if all other parameters are considered constant. If the sensing region has to be limited to within a thin sensitive layer, the splitting is proposed of one of the electrodes into a compound electrode. The optimum lay-out of this compound structure is calculated as a function of the layer thickness.     

Minimed Medtronic 780G optimizes glucose control in patients with type 1 diabetes mellitus

Background and aimsThe new advanced hybrid closed loop insulin infusion systems have the potential to significantly improve glycaemic control. The aim of this study was to evaluate the effectiveness of the Minimed 780G system in 59 patients with type 1 diabetes.Methods and resultsGlucose control obtained by using the system in automatic mode at 1–2 months of activation, at 2–4 months, at 4–6 months, and beyond 6 month was compared with those obtained with the system in manual mode. A significant improvement in time-in-range and in time-above-range throughout the follow-up was observed, as well as a significant reduction in time-below-range (<54 mg/dl) after 6 months, a significant reduction of the glucose variability and of HbA1c. After switching the mode, all target percentages lied on the average within the recommended ranges by literature consensus and no severe hypoglycemia nor ketoacidosis episodes were recorded.ConclusionThe Minimed 780G allowed a rapid and progressive improvement of the overall glucose control.     

Real-time continuous glucose monitoring using GuardianRT: from research to clinical practice

The limited number of self-monitoring blood glucose measurements is an obstacle for good metabolic control in patients with type 1 diabetes. However, continuous glucose measurement with real-time data and alarms is a recent technology that promises to improve the efficacy of treatment in diabetic patients. Guardian^®RT uses a continuous telemetry display of real-time glucose values, and automatic alerts at preset hypo- and hyperglycaemic levels. Three calibrations a day are required, and the sensor must be changed every three days. The GuardControl study showed that, within three months, real-time continuous glucose monitoring with the Guardian^®RT led to significantly improved HbA_1c values in 162 poorly controlled patients (children and adults) with type 1 diabetes despite intensive insulin therapy. The continuous availability of glucose measurements permitted the patients to adjust their own insulin doses, food intake and physical activity and, thus, improve their glycaemic control. This report summarizes the available data on this tool and details how best to use this state-of-the-art modality in diabetic patients in clinical practice.