Differential inhibition of postnatal brain,spinal cord and body growth by a growth hormone antagonist

Background  

Growth hormone (GH) plays an incompletely understood role in the development of the central nervous system (CNS). In this study, we use transgenic mice expressing a growth hormone antagonist (GHA) to explore the role of GH in regulating postnatal brain, spinal cord and body growth into adulthood. The GHA transgene encodes a protein that inhibits the binding of GH to its receptor, specifically antagonizing the trophic effects of endogenous GH.     

Fusion around the barrier for 7Li+12C

Fusion cross-sections for the ⁷Li + ¹²C reaction have been measured at energies above the Coulomb barrier by the direct detection of evaporation residues. The heavy evaporation residues with energies below 3 MeV could not be separated out from the α-particles in the spectrum and hence their contribution was estimated using statistical model calculations. The present work indicates that suppression of fusion cross-sections due to the breakup of ⁷Li may not be significant for ⁷Li + ¹²C reaction at energies around the barrier.     

UV epoxy bonding for enhanced SAW transmission and microscale acoustofluidic integration

Surface acoustic waves (SAWs) are appealing as a means to manipulate fluids within lab-on-a-chip systems. However, current acoustofluidic devices almost universally rely on elastomeric materials, especially PDMS, that are inherently ill-suited for conveyance of elastic energy due to their strong attenuation properties. Here, we explore the use of a low-viscosity UV epoxy resin for room temperature bonding of lithium niobate (LiNbO(3)), the most widely used anisotropic piezoelectric substrate used in the generation of SAWs, to standard micromachined superstrates such as Pyrex? and silicon. The bonding methodology is straightforward and allows for reliable production of sub-micron bonds that are capable of enduring the high surface strains and accelerations needed for conveyance of SAWs. Devices prepared with this approach display as much as two orders of magnitude, or 20 dB, improvement in SAW transmission compared to those fabricated using the standard PDMS elastomer. This enhancement enables a broad range of applications in acoustofluidics that are consistent with the low power requirements of portable battery-driven circuits and the development of genuinely portable lab-on-a-chip devices. The method is exemplified in the fabrication of a closed-loop bidirectional SAW pumping concept with applications in micro-scale flow control, and represents the first demonstration of closed channel SAW pumping in a bonded glass/LiNbO(3) device.     

Detection of human and rodent 5-HT3B receptor subunits by anti-peptide polyclonal antibodies

Background  

The 5-HT₃ receptor is a member of a neurotransmitter-gated ion channel family which includes nicotinic acetylcholine, GABA_A, and glycine receptors. While antibodies specific for the 5-HT_3A receptor subunit are plentiful, and have revealed a wealth of structural and functional information, few antisera exist for the detection of 5-HT_3B receptor subunits. Here we describe the generation and characterisation of a rabbit polyclonal antiserum that specifically recognises 5-HT_3B receptor subunits     

Dibenzyl Structuresin a Macromolecular Chain. III. Dibenzyldiisocyanates Reactivity

The reactivity of the 2,2′-, 2,4′-, 4,4′-dibenzyldiisocyanate (2,2′-, 2,4′-, 4,4′-DBDI) with n-butanol in benzene has been studied. The concentrations of all species were monitored by using high performance liquid chromatography (HPLC). The reactivity of 4,4′-DBDI is similar to that of 4,4′-diphenylmethanediisocyanate (4,4′-MDI). Very strong intramolecular catalytic effects were noticed in the case of 2,2′-DBDI, probably due to the variable molecular geometry. These effects are responsible for the whole reaction pattern. The 2,4′-DBDI NCO ortho and para groups reactivities are different and comparable to that of 2,4-toluylenediisocyanate (2,4-TDI).     

An electronic Venturi-based pressure microregulator

Microfluidic systems often use pressure-driven flow to induce fluidic motion, but control of pumps and valves can necessitate numerous external connections or an extensive external control infrastructure. Here, we describe an electronically controlled pressure microregulator that can output pressures both greater and less than atmospheric pressure over a range of 2 kPa from a single pressurized air input of 110 kPa. Multiple independently controlled microregulators integrated in one device can potentially share the same air input. The microregulator operates by using embedded resistive heaters to vary the temperature of a gas flowing through a converging-diverging Venturi nozzle between 25 degrees C and 85 degrees C with a resolution of 33 Pa degrees C(-1). We established the switching speed of the microregulator by accurately moving 1 microL droplets of water in a microchannel via pneumatic propulsion. Droplet deceleration from approximately 1 cm s(-1) to zero velocity required less than 0.8 s. The component is readily integrable into most device designs containing fluidic channels and electronics without introducing additional fabrication complexity.     

Untersuchung von Trinkwasser, Abwasser, Mineralwasser

Ohne Zusammenfassung     

The role of the t-SNARE SNAP-25 in action potential-dependent calcium signaling and expression in GABAergic and glutamatergic neurons

Background  

The soluble N-ethylmaleimide-sensitive factor attachment protein receptor (SNARE) complex, comprised of SNAP-25, syntaxin 1A, and VAMP-2, has been shown to be responsible for action potential (AP)-dependent, calcium-triggered release of several neurotransmitters. However, this basic fusogenic protein complex may be further specialized to suit the requirements for different neurotransmitter systems, as exemplified by neurons and neuroendocrine cells. In this study, we investigate the effects of SNAP-25 ablation on spontaneous neuronal activity and the expression of functionally distinct isoforms of this t-SNARE in GABAergic and glutamatergic neurons of the adult brain.     

Recognition of the nonpolar base 4-methylindole in DNA by the DNA repair adenine glycosylase MutY

[formula: see text] The DNA repair adenine glycosylase MutY efficiently recognizes 7-deaza-2'-deoxyadenosine (Z) and its nonpolar isostere 4-methylindole beta-deoxynucleoside (M) opposite 7,8-dihydro-8-oxo-2'-deoxyguanosine (OG) and G in DNA. Both wild-type and truncated MutY exhibit a 10- to 20-fold higher affinity for a duplex containing OG:M than OG:Z. More efficient recognition of M over Z by MutY may be to due the lack of hydrogen bonding with the OG that facilitates nucleotide flipping during the substrate recognition process.