1,084 research outputs found
Dysphagia in children with esophageal atresia: current diagnostic options
© 2017 Georg Thieme Verlag KGDysphagia or swallowing disorder is very common (range, 15–52%) in patients with esophageal atresia. Children present with a wide range of symptoms. The most common diagnostic tools to evaluate esophageal dysphagia, such as upper barium study and manometry, aim to characterize anatomy and function of the esophageal body and the esophagogastric junction (EGJ). Using these technologies, a variety of pathological motor patterns have been identified in children with esophageal atresia. However, the most challenging part of diagnosing patients with esophageal dysphagia lies in the fact that these methods fail to link functional symptoms such as dysphagia with the esophageal motor disorders observed. A recent method, called pressure-flow analysis (PFA), uses simultaneously acquired impedance and manometry measurements, and applies an integrated analysis of these recordings to derive quantitative pressure-flow metrics. These pressure-flow metrics allow detection of the interplay between bolus flow, motor patterns, and symptomatology by combining data on bolus transit and bolus flow resistance. Based on a dichotomous categorization, flow resistance at the EGJ and ineffective esophageal bolus transit can be determined. This method has the potential to guide therapeutic decisions for esophageal dysmotility in pediatric patients with esophageal atresia
Ocular manifestations during during a normal pregnancy
Ocular manifestations during during a normal pregnanc
Deep Submicron III-V on Si-Based Esaki Diode
Esaki tunneling diodes are reemerging as a viable technology option in helping to improve speed and performance of many high speed device applications. The revival of this technology may be linked to the development of new substrates available to research that allows for the fabrication of a device comparable to current silicon technology. Using a 111-V on Silicon Substrate, it was demonstrated that it is possible to create working Esaki Tunneling Diodes
Interaction of three regiospecific amino acid residues is required for OATP1B1 gain of OATP1B3 substrate specificity
The human organic anion-transporting polypeptides OATP1B1 (SLCO1B1) and OATP1B3 (SLCO1B3) are liver-enriched membrane transporters of major importance to hepatic uptake of numerous endogenous compounds, including bile acids, steroid conjugates, hormones, and drugs, including the 3-hydroxy-3- methylglutaryl Co-A reductase inhibitor (statin) family of cholesterol-lowering compounds. Despite their remarkable substrate overlap, there are notable exceptions: in particular, the gastrointestinal peptide hormone cholecystokinin-8 (CCK-8) is a high affinity substrate for OATP1B3 but not OATP1B1. We utilized homologous recombination of linear DNA by E. coli to generate a library of cDNA containing monomer size chimeric OATP1B1-1B3 and OATP1B3-1B1 transporters with randomly distributed chimeric junctions to identify three discrete regions of the transporter involved in conferring CCK-8 transport activity. Site-directed mutagenesis of three key residues in OATP1B1 transmembrane helices 1 and 10, and extracellular loop 6, to the corresponding residues in OATP1B3, resulted in a gain of CCK-8 transport by OATP1B1. The residues appear specific to CCK-8, as the mutations did not affect transport of the shared OATP1B substrate atorvastatin or the OATP1B1-specific substrate estrone sulfate. Regions involved in gain of CCK-8 transport by OATP1B1, when mapped to the crystal structures of bacterial transporters from the major facilitator superfamily, are positioned to suggest these regions could readily interact with drug substrates. Accordingly, our data provide new insight into the molecular determinants of the substrate specificity of these hepatic uptake transporters with relevance to targeted drug design and prediction of drug-drug interactions. © 2012 American Chemical Society
Requirements for Bend Insensitive Fiber in Millimeter-Wave Fronthaul Systems
The impact of fiber bending on mm-wave radio-over-fiber transmission is investigated and the need for bend insensitive fiber for front-haul installation confirmed. A 70m W-band hybrid photonic-wireless link including bend insensitive fiber is demonstrated with BER<10\u3csup\u3e-6\u3c/sup\u3e at 5mm bending radius
The p110 delta structure: mechanisms for selectivity and potency of new PI(3)K inhibitors.
Deregulation of the phosphoinositide-3-OH kinase (PI(3)K) pathway has been implicated in numerous pathologies including cancer, diabetes, thrombosis, rheumatoid arthritis and asthma. Recently, small-molecule and ATP-competitive PI(3)K inhibitors with a wide range of selectivities have entered clinical development. In order to understand the mechanisms underlying the isoform selectivity of these inhibitors, we developed a new expression strategy that enabled us to determine to our knowledge the first crystal structure of the catalytic subunit of the class IA PI(3)K p110 delta. Structures of this enzyme in complex with a broad panel of isoform- and pan-selective class I PI(3)K inhibitors reveal that selectivity toward p110 delta can be achieved by exploiting its conformational flexibility and the sequence diversity of active site residues that do not contact ATP. We have used these observations to rationalize and synthesize highly selective inhibitors for p110 delta with greatly improved potencies
W-band photonic-wireless link with a Schottky diode envelope detector and bend insensitive fiber
The performance and potential of a W-band radio-over-fiber link is analyzed, including a characterization of the wireless channel. The presented setup focuses on minimizing complexity in the radio frequency domain, using a passive radio frequency transmitter and a Schottky diode based envelope detector. Performance is experimentally validated with carriers at 75–87GHz over wireless distances of 30–70m. Finally the necessity for and impact of bend insensitive fiber for on-site installation are discussed and experimentally investigated
Self-gravitating domain walls and the thin-wall limit
We analyse the distributional thin wall limit of self gravitating scalar
field configurations representing thick domain wall geometries. We show that
thick wall solutions can be generated by appropiate scaling of the thin wall
ones, and obtain an exact solution for a domain wall that interpolates between
AdS_4 asymptotic vacua and has a well-defined thin wall limit.Solutions
representing scalar field configurations obtained via the same scaling but that
do not have a thin wall limit are also presented.Comment: 10 pages, revte
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