捷安肽素高产突变株96孔板筛选方法的建立

建立了一种快速灵敏地筛选出捷安肽素(JAA)高产突变株的方法。主要利用96多孔板固体培养菌体,用50%乙醇为最佳浸提液浸提4h,滤纸片法检测JAA生物活性的点样量为100μL,筛选出5株高产突变株,经摇瓶复筛选出2株高产突变株,经一剂量法检测,其抑菌圈直径较出发菌株提高了14%左右。     

Evaluation of filter paper collection of urine samples for detection and measurement of organic acidurias by capillary electrophoresis

There is little doubt that mental retardation has been prevented in most babies diagnosed by newborn screening programs for inborn errors and the cost-benefit ratios of these programs have been reported as highly positive. In a previous work we optimised a CE method for quick profiling of organic acidurias, which characterize a large number of inborn errors, so that it permits the separation, detection and even identification in less than 15 min of 22 organic acids in urine samples related to a wide range of metabolic disorders. In the present work we have studied the adequacy of filter paper collection of urine samples to simplify this step, always difficult in babies, when it is not performed by training personnel. The studied parameters were: media and conditions for re-extraction to give the best sensitivity and a more simple procedure when the samples are measured by CE, interferences coming from the diaper, recoveries obtained, possible correction of recoveries with creatinine and stability of the compounds. The whole method we report has the advantages of easy sample collection, easy shipping or delivery, and rapid analysis. Moreover, this method of collection and analysis allows the identification and quantitation of fumaric, methylmalonic, N-acetylaspartic, pyroglutamic and homogentisic acids, as well as glutaric acid for which screening is considered especially advisable.     

Agreement between spatiotemporal parameters from a photoelectric system with different filter settings and high-speed video analysis during running on a treadmill at comfortable velocity

The aim of this study was to determine the level of agreement between spatiotemporal gait characteristics from a photoelectric system with different filter settings and high-speed video analysis during running on a treadmill at comfortable velocity. Forty-nine runners performed a running protocol on a treadmill at comfortable velocity. Two systems were used to determine spatiotemporal parameters (i.e. contact time [CT], flight time [FT], step frequency [SF] and step length [SL]) during running: OptoGait system and high-speed video analysis at 1000 Hz. The collected data was re-filtered in the OptoGait software by using nine different settings (i.e. 0_0, 1_1, 2_2, 3_3, 3_4, 4_4, 4_5, 5_4 and 5_5), and compared to those obtained through video analysis. The Pearson correlation analysis revealed very large correlations (r > 0.9, p < 0.001) in CT, FT, SF and SL between both systems, regardless of the OptoGait’s filter settings. The ICC reported an almost perfect association (ICC > 0.9) for both SL and SF regardless of the filter setting. However, large variations between filter settings according to the data from video analysis were reported in CT and FT (0_0, 1_1 and 2_2 filter settings obtained an association ICC > 0.9, whereas other filters obtained lower ICCs). Bland-Altman plots revealed small bias and error and no presence of heteroscedasticity of error for 1_1 setting. In conclusion, the filter setting for the OptoGait system should be considered to minimize the bias and error of spatiotemporal parameters measurement. For running on a treadmill, the 1_1 filter setting is recommended if gait parameters are to be compared to a high-speed video analysis (1000 Hz).     

A high‐throughput sample preparation method for cellular proteomics using 96‐well filter plates

A high‐throughput sample preparation protocol based on the use of 96‐well molecular weight cutoff (MWCO) filter plates was developed for shotgun proteomics of cell lysates. All sample preparation steps, including cell lysis, buffer exchange, protein denaturation, reduction, alkylation and proteolytic digestion are performed in a 96‐well plate format, making the platform extremely well suited for processing large numbers of samples and directly compatible with functional assays for cellular proteomics. In addition, the usage of a single plate for all sample preparation steps following cell lysis reduces potential samples losses and allows for automation. The MWCO filter also enables sample concentration, thereby increasing the overall sensitivity, and implementation of washing steps involving organic solvents, for example, to remove cell membranes constituents. The optimized protocol allowed for higher throughput with improved sensitivity in terms of the number of identified cellular proteins when compared to an established protocol employing gel‐filtration columns.     

基于DSP与FPAA的电化学信号滤波器

目的：研究对自主研发的DNA电化学分析仪所采集电化学信号的噪声的滤除方法。方法：根据电化学噪声信号的特征及其频率分布范围,采用由现场可编程模拟阵列（FPAA）实现的有高阶低通滤波器和基于DSP实现的FIR数字滤波器相结合的方式,对混合在电化学信号中的高频噪声信号进行滤除。结果：对滤波结果进行分析,频率在100HZ以上的噪声信号基本滤除。结论：FPAA与DSP芯片的结合构成了一个稳定性高,线性相位特性好,实时性强的高效滤波器。     

基于DSP 与FPAA 的电化学信号滤波器

目的:研究对自主研发的DNA电化学分析仪所采集电化学信号的噪声的滤除方法。方法:根据电化学噪声信号的特征及其频率分布范围,采用由现场可编程模拟阵列(FPAA)实现的有高阶低通滤波器和基于DSP实现的FIR数字滤波器相结合的方式,对混合在电化学信号中的高频噪声信号进行滤除。结果:对滤波结果进行分析,频率在100HZ以上的噪声信号基本滤除。结论:FPAA与DSP芯片的结合构成了一个稳定性高,线性相位特性好,实时性强的高效滤波器。     

Rosette Colonies of Choanoflagellates (Salpingoeca rosetta) Show Increased Food Vacuole Formation Compared with Single Swimming Cells

Choanoflagellates exist as both single‐celled and colonial forms and filter‐feed by generating water currents using a single apical flagellum. Hydrodynamic modeling studies have differed in predictions of whether single cells or colonies produce greater fluid flow to enhance feeding, and a recent study reported no increase in feeding efficiency of stalked colonies of choanoflagellates compared with single cells. We report that rosette colonies of Salpingoeca rosetta demonstrate higher rates of food vacuole formation compared with unicellular, slow swimmers.     

Identification and characterization of functional aquaporin water channel protein from alimentary tract of whitefly, Bemisia tabaci

Some hemipteran xylem and phloem-feeding insects have evolved specialized alimentary structures or filter chambers that rapidly transport water for excretion or osmoregulation. In the whitefly, Bemisia tabaci, mass movement of water through opposing alimentary tract tissues within the filter chamber is likely facilitated by an aquaporin protein. B. tabaci aquaporin-1 (BtAQP1) possesses characteristic aquaporin topology and conserved pore-forming residues found in water-specific aquaporins. As predicted for an integral transmembrane protein, recombinant BtAQP1 expressed in cultured insect cells localized within the plasma membrane. BtAQP1 is primarily expressed in early instar nymphs and adults, where in adults it is localized in the filter chamber and hindgut. Xenopus oocytes expressing BtAQP1 were water permeable and mercury-sensitive, both characteristics of classical water-specific aquaporins. These data support the hypothesis that BtAQP1 is a water transport protein within the specialized filter chamber of the alimentary tract and functions to translocate water across tissues for maintenance of osmotic pressure and/or excretion of excess dietary fluid.