An automated, parallel processing approach to biomolecular sample preparation

Sample preparation for DNA and RNA assays is a prime candidate for laboratory automation. A novel, parallel processing device that performs the three separate liquid-handling functions necessary for such sample preparation-dispensing, pipetting, and pressurizing-is presented. The device comprises an array of fine nozzles connected by fluidic channels to automatically and precisely distribute flow between one source and an array of points. The design principles, as well as the experimental and computational methods used to develop the device, are described. Test results, including accuracy, uniformity, volume range, and timing, are presented. The functionality of the device is demonstrated by performing a solid-phase extraction of DNA with two types of microcolumns.     

Conventional and Unconventional Mechanisms by which Exocytosis Proteins Oversee β-cell Function and Protection

Type 2 diabetes (T2D) is one of the prominent causes of morbidity and mortality in the United States and beyond, reaching global pandemic proportions. One hallmark of T2D is dysfunctional glucose-stimulated insulin secretion from the pancreatic β-cell. Insulin is secreted via the recruitment of insulin secretory granules to the plasma membrane, where the soluble N-ethylmaleimide-sensitive factor attachment protein receptors (SNAREs) and SNARE regulators work together to dock the secretory granules and release insulin into the circulation. SNARE proteins and their regulators include the Syntaxins, SNAPs, Sec1/Munc18, VAMPs, and double C2-domain proteins. Recent studies using genomics, proteomics, and biochemical approaches have linked deficiencies of exocytosis proteins with the onset and progression of T2D. Promising results are also emerging wherein restoration or enhancement of certain exocytosis proteins to β-cells improves whole-body glucose homeostasis, enhances β-cell function, and surprisingly, protection of β-cell mass. Intriguingly, overexpression and knockout studies have revealed novel functions of certain exocytosis proteins, like Syntaxin 4, suggesting that exocytosis proteins can impact a variety of pathways, including inflammatory signaling and aging. In this review, we present the conventional and unconventional functions of β-cell exocytosis proteins in normal physiology and T2D and describe how these insights might improve clinical care for T2D.     

The inhibitive effect of extraneous ion addition on stress corrosion cracking of alpha-brass

The addition of ammonium chloride, cobalt sulphate, cesium sulphate and ethylene diamine to a Mattsson solution and the addition of ammonium sulphate to the Pugh solution have been found to produce an inhibitive effect on the stress corrosion cracking of alpha-brass in these solutions. Ammonium chloride and ammonium sulphate additions affect the tarnish formation on the specimen as well as the cracking pattern. Electrochemical polarization studies have also been carried out with these two additives. The observations have been explained in the light of adsorption of these ionic species at selected sites on the metal surface and their possible interference with the cathodic reactions.     

Mass transfer from a carbon dioxide jet to tap water

When a jet of soluble gas is directed on to liquid surface, the kinetic energy of the jet is transferred to the liquid giving rise to circulation, which in turn enhances mass transfer. Consequently, the mass transfer coefficient is related to the characteristics of the jet.     

Polynomial-Time Algorithms for Energy Games with Special Weight Structures

Energy games belong to a class of turn-based two-player infinite-duration games played on a weighted directed graph. It is one of the rare and intriguing combinatorial problems that lie in NP∩co-NP, but are not known to be in P. The existence of polynomial-time algorithms has been a major open problem for decades and apart from pseudopolynomial algorithms there is no algorithm that solves any non-trivial subclass in polynomial time. In this paper, we give several results based on the weight structures of the graph. First, we identify a notion of penalty and present a polynomial-time algorithm when the penalty is large. Our algorithm is the first polynomial-time algorithm on a large class of weighted graphs. It includes several worst-case instances on which previous algorithms, such as value iteration and random facet algorithms, require at least sub-exponential time. Our main technique is developing the first non-trivial approximation algorithm and showing how to convert it to an exact algorithm. Moreover, we show that in a practical case in verification where weights are clustered around a constant number of values, the energy game problem can be solved in polynomial time. We also show that the problem is still as hard as in general when the clique-width is bounded or the graph is strongly ergodic, suggesting that restricting the graph structure does not necessarily help.     

Synthesizing robust systems

Systems should not only be correct but also robust in the sense that they behave reasonably in unexpected situations. This article addresses synthesis of robust reactive systems from temporal specifications. Existing methods allow arbitrary behavior if assumptions in the specification are violated. To overcome this, we define two robustness notions, combine them, and show how to enforce them in synthesis. The first notion applies to safety properties: If safety assumptions are violated temporarily, we require that the system recovers to normal operation with as few errors as possible. The second notion requires that, if liveness assumptions are violated, as many guarantees as possible should be fulfilled nevertheless. We present a synthesis procedure achieving this for the important class of GR(1) specifications, and establish complexity bounds. We also present an implementation of a special case of robustness, and show experimental results.     

NH3-NO/NO2 SCR for diesel exhausts after treatment: mechanism and modelling of a catalytic converter

We review herein the key mechanistic and kinetic features of the reactions involved in the NH₃-NO/NO₂ SCR system investigated by dynamic reactive experiments over a V-based commercial powdered catalyst, eventually leading to the proposal of an original redox scheme which accounts for stoichiometry, selectivity and intrinsic kinetics of the global SCR process.     

The beneficial effect of small amount of water in the ambient temperature atom transfer radical homo and block co-polymerization of methacrylates

ATRP of several methacrylates viz. methyl methacrylate (MMA), ethyl methacrylate (EMA), n-butyl methacrylate (nBMA), t-butyl methacrylate (tBMA), benzyl methacrylate (BzMA) and (N,N-dimethylamino)ethyl methacrylate (DMAEMA) has been studied in neat as well as aqueous (up to 12 vol% water) acetone at 35 °C using CuCl/bipyridine (bpy) catalyst and ethyl 2-bromoisobutyrate as the initiator. Addition of water significantly enhances the rate of polymerization without losing control. Unlike CuCl/bpy the CuBr/bpy catalyst gives poor control which is attributed to the lower solubility and consequent heterogeneity in the latter case. Of the other ligands used with the CuCl catalyst viz. o-phenanthroline (o-phen), 1,1,4,7,7-pentamethyldiethylenetriamine (PMDETA), 1,1,4,7,10,10-hexamethyltriethylenetetramine (HMTETA), Me₆TREN only o-phen offers reasonably good control. The CuCl/bpy catalyst system has been used also in preparing some di- and tri-block copolymers with reasonably low polydispersity index (PDI) at ambient temperature (35 °C) using aqueous acetone as the solvent. The following block copolymers have been prepared PMMA-tBMA, PMMA-b-tBMA-b-MMA, PMMA-DMAEMA, by this method.     

Brain tumor detection based on hybrid deep neural network in MRI by adaptive squirrel search optimization

In the medical field, image segmentation is a paramount and challenging task. The head and vertebral column make up the central nervous system (CNS), which control all the paramount functions. These include thinking, speaking, and gestures. The uncontrolled growth in the CNS can affect a person’s thinking of communication or movement. The tumor is known as the uncontrolled growth of cells in brain. The tumor can be recognized by MRI image. Brain tumor detection is mostly affected with inaccurate classification. This proposed work designed a novel classification and segmentation algorithm for the brain tumor detection. The proposed system uses the Adaptive fuzzy deep neural network with frog leap optimization to detect normality and abnormality of the image. Accurate classification is achieved with error minimization strategy through our proposed method. Then, the abnormal image is segmented using adaptive flying squirrel algorithm and the size of the tumor is detected, which is used to find out the severity of the tumor. The proposed work is implemented in the MATLAB simulation platform. The proposed work Accuracy, sensitivity, specificity, false positive rate and false negative rate are 99.6%, 99.9%, 99.8%, 0.0043 and 0.543, respectively. The detection accuracy is better in our proposed system than the existing teaching and learning based algorithm, social group algorithm and deep neural network.