5,058 research outputs found
Spontaneous formation of a chiral (Mo2O2S2)2+-based cluster driven by dimeric {Te2O6}-based templates
Utilization of [Mo2S2O2(H2O)6]2+ and a tellurite anion led to the formation of three new clusters, 1–3, with unique structural features. The tellurite anion not only templated the formation of [(Mo2O2S2)4(TeO3)(OH)9]3− 1 and [(Mo2O2S2)12(TeO3)4(TeO4)2 (OH)18]10− 3, but also the in situ generation of two different types of dimeric {Te2O6} based moieties induced the spontaneous assembly of the chiral [(Mo2O2S2)10(TeO3)(Te2O6)2(OH)18]8− anionic cluster, 2
Integrated digital/electric aircraft concepts study
The integrated digital/electrical aircraft (IDEA) is an aircraft concept which employs all electric secondary power systems and advanced digital flight control systems. After trade analysis, preferred systems were applied to the baseline configuration. An additional configuration, the alternate IDEA, was also considered. For this concept the design ground rules were relaxed in order to quantify additional synergistic benefits. It was proposed that an IDEA configuration and technical risks associated with the IDEA systems concepts be defined and the research and development required activities to reduce these risks be identified. The selected subsystems include: power generation, power distribution, actuators, environmental control system and flight controls systems. When the aircraft was resized, block fuel was predicted to decrease by 11.3 percent, with 7.9 percent decrease in direct operating cost. The alternate IDEA shows a further 3.4 percent reduction in block fuel and 3.1 percent reduction in direct operating cost
Essential residues for the enzyme activity of ATP-dependent MurE ligase from Mycobacterium tuberculosis
The emergence of total drug-resistant tuberculosis (TDRTB) has made the discovery of new therapies for tuberculosis urgent. The cytoplasmic enzymes of peptidoglycan biosynthesis have generated renewed interest as attractive targets for the development of new anti-mycobacterials. One of the cytoplasmic enzymes, uridine diphosphate (UDP)-MurNAc-tripeptide ligase (MurE), catalyses the addition of meso-diaminopimelic acid (m-DAP) into peptidoglycan in Mycobacterium tuberculosis coupled to the hydrolysis of ATP. Mutants of M. tuberculosis MurE were generated by replacing K157, E220, D392, R451 with alanine and N449 with aspartate, and truncating the first 24 amino acid residues at the N-terminus of the enzyme. Analysis of the specific activity of these proteins suggested that apart from the 24 Nterminal residues, the other mutated residues are essential for catalysis. Variations in K m values for one or more substrates were observed for all mutants, except the N-terminal truncation mutant, indicating that these residues are involved in binding substrates and form part of the active site structure. These mutant proteins were also tested for their specificity for a wide range of substrates. Interestingly, the mutations K157A, E220A and D392A showed hydrolysis of ATP uncoupled from catalysis. The ATP hydrolysis rate was enhanced by at least partial occupation of the uridine nucleotide dipeptide binding site. This study provides an insight into the residues essential for the catalytic activity and substrate binding of the ATP-dependent MurE ligase. Since ATP-dependent MurE ligase is a novel drug target, the understanding of its function may lead to development of novel inhibitors against resistant forms of M. tuberculosis
Visual phototransduction components in cephalopod chromatophores suggest dermal photoreception
Author Posting. © The Author(s), 2015. This is the author's version of the work. It is posted here by permission of The Company of Biologists for personal use, not for redistribution. The definitive version was published in Journal of Experimental Biology 218 (2015): 1596-1602, doi: 10.1242/​jeb.117945.Cephalopod molluscs are renowned for their colorful and dynamic body patterns, produced by an
assemblage of skin components that interact with light. These may include iridophores,
leucophores, chromatophores, and (in some species) photophores. Here, we present molecular
evidence suggesting that cephalopod chromatophores, small dermal pigmentary organs that
reflect various colors of light, are photosensitive. RT-PCR revealed the presence of transcripts
encoding rhodopsin and retinochrome within the retinas and skin of the squid Doryteuthis
pealeii, and the cuttlefish Sepia officinalis and Sepia latimanus. In D. pealeii, Gqα and squid
TRP channel transcripts were present in the retina and in all dermal samples. Rhodopsin,
retinochrome, and Gqα transcripts were also found in RNA extracts from dissociated
chromatophores isolated from D. pealeii dermal tissues. In D. pealeii, immunohistochemical
staining labeled rhodopsin, retinochrome, and Gqα proteins in several chromatophore
components, including pigment cell membranes, radial muscle fibers, and sheath cells. This is
the first evidence that cephalopod dermal tissues, and specifically chromatophores, may possess
the requisite combination of molecules required to respond to light.This research was supported by the Office of Naval Research Basic Research Challenge [grant number N00014-10-0989] via a subcontract to T.W.C. and R.T.H.2016-05-1
Evaluation of flight foods under hypokinetic conditions, part 2, chapters 4 and 5
Effects of weightlessness on body temperature and heart rate determined by 56 day bed rest stud
Observation of a baryon resonance with positive strangeness in K+ collisions with Xe nuclei
The status of our investigation of low-energy Xe collisions in the Xenon
bubble chamber DIANA is reported. In the charge-exchange reaction the spectrum of effective mass shows a resonant enhancement
with MeV/c and ^24.4\sigma$. The mass and width of the
observed resonance are consistent with expectations for the lightest member of
the anti-decuplet of exotic pentaquark baryons, as predicted in the framework
of the chiral soliton model.Comment: 9 pages, 4 figure
Relation of Parkinson\u27s Disease Subtypes to Visual Activities of Daily Living
Visual perceptual problems are common in Parkinson\u27s disease (PD) and often affect activities of daily living (ADLs). PD patients with non-tremor symptoms at disease onset (i.e., rigidity, bradykinesia, gait disturbance or postural instability) have more diffuse neurobiological abnormalities and report worse non-motor symptoms and functional changes than patients whose initial symptom is tremor, but the relation of motor symptom subtype to perceptual deficits remains unstudied. We assessed visual ADLs with the Visual Activities Questionnaire in 25 non-demented patients with PD, 13 with tremor as the initial symptom and 12 with an initial symptom other than tremor, as well as in 23 healthy control participants (NC). As expected, the non-tremor patients, but not the tremor patients, reported more impairment in visual ADLs than the NC group, including in light/dark adaptation, acuity/spatial vision, depth perception, peripheral vision and visual processing speed. Non-tremor patients were significantly worse than tremor patients overall and on light/dark adaptation and depth perception. Environmental enhancements especially targeted to patients with the non-tremor PD subtype may help to ameliorate their functional disability
OA03.01. Acupuncture for chronic pain: an individual patient data meta-analysis of randomized trials
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