Decoding the Chemical Language of Motile Bacteria by Using High‐Throughput Microfluidic Assays

Motile bacteria navigate chemical environments by using chemoreceptors. The output of these protein sensors is linked to motility machinery and enables bacteria to follow chemical gradients. Understanding the chemical specificity of different families of chemoreceptors is essential for predicting and controlling bacterial behavior in ecological niches, including symbiotic and pathogenic interactions with plants and mammals. The identification of chemical(s) recognized by specific families of receptors is limited by the low throughput and complexity of chemotaxis assays. To address this challenge, we developed a microfluidic‐based chemotaxis assay that is quantitative, simple, and enables high‐throughput measurements of bacterial response to different chemicals. Using the model bacterium Escherichia coli, we demonstrated a strategy for identifying molecules that activate chemoreceptors from a diverse compound library and for determining how global behavioral strategies are tuned to chemical environments.     

Determination of sulphadimidine in animal feedstuffs by an enzyme-linked immunoassay

An enzyme immunoassay technique for the determination of sulphadimidine in animal feedstuffs has been developed. The antibody showed limited cross-reactivity with other drugs, including sulphonamides, used as feed additives. Using spiked samples recoveries of 80-88% were obtained. The limit of detection of the assay was 70 ng/g.     

机柜也需要细心呵护!

作为一家专业机柜生产厂商,所生产的产品主要在恶劣的环境中为电气和电子部件提供保护,有时客户会要求厂商现场协助解决一些设计和使用中碰到的问题。进行现场评估时,会经常发现基本的机柜设计并没有问题,导致问题的是一些其它因素。有时是安装不正确。例如,安装不正确的液体密封导管配件或电缆衬垫会导致灰尘或水进入机柜,幸运的是,此类问题通常在安装后不久就可发现并可快速解决。然而,对于那些需要数月或数年时间才会逐渐显现的问题怎么办?暖气炉在每个取暖季节前都会进行清洁,每3000英里汽车机油也需要更换,我们自己更是(或应该)进行例…     

Phenomenology in Absentia: Dennett's Philosophy of Mind.

Daniel Dennett's philosophical abolition of mind is examined with reference to its methodology, intent, philosophic origins, and internal consistency. His treatment of the contents of perception and introspection is shown to be derivative from realist reductionist misinterpretations of physics, physiology, and phenomenology of perception. In order to rectify inconsistencies of that realistic paradigm devolved from psycho-neural identity theory of mid-twentieth century, Dennett radicalizes its logic and redefines even veridical phenomenology of exteroception to be "illusory." This measure in extremis still does not save the appearances of his predecessors, nevertheless, for Dennett tacitly presupposes the existence of veridical phenomenology in his very treatment of non-veridical sensory phenomena that he uses to argue analogically from, to thereby suggest the plausibility of a parallel illusoriness of veridical phenomena of perception and introspection. This inhering inconsistency renders unsound Dennett's radical extension of the logic of identity theory, and ironically shows up the persistence of mental phenomenology that extant reductionism appears so desirous to argumentively eliminate. Nonetheless there is much to be learned from such an analysis of Dennett's purported elimination of mental contents, for a generalization of our critique throws light on the occult assumptions underlying realism and reductionism since early identity theory and its variants, and upon the possible viability of that programme as a whole. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Clean intermittent catheterization for home management in children with myelomeningocele

Sixty-two children with myelomeningocele and neurogenic bladders have been managed with clean intermittent catheterization (CIC) at home for periods of 6 to 42 months. Abnormal upper urinary tracts improved or stabilized in 83 per cent of the children. There was no renal deterioration in children who began with normal upper tracts while on CIC. Bacteruria was common, but clinically not a problem, unless ureterovesical reflux was present. Urinary control was improved in 66 per cent of the children. CIC is an effective and safe method to regularly empty the urinary bladder and is an alternative to supravesical urinary diversion in many children with neurogenic bladders.     

Li/Li2 supersonic nozzle beam

The characterization of a lithium supersonic nozzle beam has been made using spectroscopic techniques. It is found that at a stagnation pressure of 5.3 kPa (40 Torr) and a nozzle throat diameter of 0.4 mm the ground state vibrational population of Li(2) can be described by a Boltzmann distribution with T(v)= (195+/-30) K. The rotational temperature is found to be T(r)= (70+/-20) K by band shape analysis. Measurements by quadrupole mass spectrometer indicate that approximately 10-mol. % Li(2) dimers are present far downstream for an oven body temperature of 1370 K in the supersonic nozzle expansion. This measured mole fraction is in agreement with the existing dimerization theory.     

The Ultralight Steel Auto Body program completes phase I

The UltraLight Steel Auto Body program was initiated by the American Iron and Steel Institute and the International Iron and Steel Institute. The purpose of the program is to demonstrate the advantages of steel for reducing the weight of the automotive body-in-white. The holistic design approach—considering the body structure, materials, manufacturing methods, and engineering analysis together—has yielded a design for a body-in-white that is about 25 percent lighter than a typical vehicle produced at present, with improved structural performance. The materials and manufacturing processes required for the design are either in use or “near-reach” technologies.     

Thyroid palpation versus high-resolution thyroid ultrasonography in the detection of nodules

Detection of thyroid nodules by physical examination and high-resolution ultrasonography was compared using small groups of blinded, experienced physician examiners working with a sample of 2441 persons from Estonia, most of whom were Chernobyl nuclear reactor clean-up workers. A random subsample of 113 (5%) persons was subjected to triple control examinations with both physical examination and high-resolution ultrasonography. Positive high-resolution ultrasonographic findings were considerably more reproducible among different observers than were positive physical examination findings. Agreement between methods was poor. Nodules were found in 169 (6.9%) subjects by physical examination and in 249 (10.2%) subjects by high-resolution ultrasonography. Physical examination found only 53 (21%) of the 249 nodules found by high-resolution ultrasonography. High-resolution ultrasonography did not confirm the existence of 115 (68%) of the 169 nodules found by physical examination. Only 6.4% of nodules less than 0.5 cm in diameter, as based on high-resolution ultrasonographic results, were detected by physical examination. Physical examination detection improved with increasing nodule size but was still only 48.2% for nodules larger than 2 cm. Physical examination was relatively effective in detecting nodules in the isthmus of the thyroid gland but much less so for nodules in the upper pole of the gland. Clinical evaluation and epidemiologic studies of nodular thyroid disease stand to benefit from the greater sensitivity and specificity of ultrasonographic examinations.