766 research outputs found
Primordial Black Holes from Sound Speed Resonance during Inflation
We report on a novel phenomenon of the resonance effect of primordial density
perturbations arisen from a sound speed parameter with an oscillatory behavior,
which can generically lead to the formation of primordial black holes in the
early Universe. For a general inflaton field, it can seed primordial density
fluctuations and their propagation is governed by a parameter of sound speed
square. Once if this parameter achieves an oscillatory feature for a while
during inflation, a significant non-perturbative resonance effect on the
inflaton field fluctuations takes place around a critical length scale, which
results in significant peaks in the primordial power spectrum. By virtue of
this robust mechanism, primordial black holes with specific mass function can
be produced with a sufficient abundance for dark matter in sizable parameter
ranges.Comment: 6 pages, 4 figures; v2: figures replotted with corrections, analysis
extended, version accepted by Phys.Rev.Let
Characterization of the Antheraea pernyi abnormal wing disc gene that may contribute to its temperature tolerance
It has been known that the abnormal wing disc (awd) gene encodes a nucleoside diphosphate kinase and is closely related to wing development in Drosophila melanogaster and Bombyx mori. In the present study, the awd gene was isolated and characterized from Antheraea pernyi, a well-known wild silkmoth. The isolated cDNA sequence is 666 bp in length with an open reading frame of 462 bp encoding a polypeptide of 153 amino acids, which contains a putative nucleoside diphosphate kinases active site motif and conserved multimer interface. The deduced A. pernyi awd protein sequence reveals 75, 82 and 96% identity with its homologue of Homo sapiens, D. melanogaster, and B. mori, respectively. Semi-quantitative reverse transcriptase-polymerase chain reaction (RT-PCR) analysis showed that the awd gene was transcribed during all four developmental stages (egg, larva, pupa, and moth), and present in all tissues tested (blood, midgut, silk glands, Malpighian tublues, spermaries, ovaries, brain, muscle, fat body and body wall), with the highest abundance in Malpighian tubules. Interestingly, mRNA expression level in pupal fat body was significantly down-regulated after cold shock (4°C) compared with the control (26°C) and significantly up-regulated after heat shock (46°C). The results indicated that the A. pernyi awd gene is inducible, and that its expression effect is different after cold stress and heat stress. Consequently, we refer that the product of the awd gene may contribute to its temperature tolerance.Key words: Antheraea pernyi, abnormal wing disc gene, cloning, expression pattern, temperature stress
Tracking crystal-melt segregation and magma recharge using zircon trace element data
The Cretaceous Yunshan caldera complex in SE China consists of an unusual coexisting assemblage of peraluminous and peralkaline rhyolites and a resurgent intra-caldera porphyritic quartz monzonite. In this study, we use zircon trace element data to study the compositional differences of zircons from cogenetic magmas and to track the evolution of the entire magmatic system. Our results indicate that the zircons from the peraluminous and peralkaline rhyolites formed from highly evolved compositions with high Hf concentrations and low Ti contents, and low Th/U and Zr/Hf ratios, which are distinct from those of the intrusive porphyritic quartz monzonite. Zircons from the peraluminous and peralkaline rhyolites display overlapping Zr/Hf and Hf, but the zircons from the peralkaline rhyolites have extremely low Eu/Eu* ratios (Peer reviewe
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Comparison of opioidâfree and opioidâinclusive propofol anaesthesia for thyroid and parathyroid surgery: a randomised controlled trial
BackgroundPostoperative nausea and vomiting occur frequently following thyroid and parathyroid surgery and are associated with worse patient outcomes. We hypothesised that opioid-free propofol anaesthesia would reduce the incidence of postoperative nausea and vomiting compared with opioid-inclusive propofol anaesthesia in patients undergoing these procedures.MethodsWe conducted a randomised, double-blinded controlled trial in adult patients scheduled to undergo thyroid and parathyroid surgery at two medical centres in mainland China. Patients were allocated randomly (1:1, stratified by sex and trial site) to an opioid-free anaesthesia group (esketamine, lidocaine, dexmedetomidine and propofol) or an opioid-inclusive group (sufentanil and propofol). Propofol infusions were titrated to bispectral index 45-55. Patients received prophylaxis for nausea and vomiting using dexamethasone and ondansetron and multimodal analgesia with paracetamol and flurbiprofen axetil. The primary outcome was the incidence of postoperative nausea and vomiting in the first 48âh after surgery.ResultsWe assessed 557 patients for eligibility and 394 completed this trial. The incidence of postoperative nausea and vomiting in the first postoperative 48âh was lower in the opioid-free anaesthesia group (10/197, 5%) compared with opioid-inclusive group (47/197, 24%) (OR (95%CI) 0.17 (0.08-0.35), pâ<â0.001), yielding a number needed to treat of 5.3. Additionally, opioid-free propofol anaesthesia was associated with a reduced need for rescue anti-emetics, lower rates of hypotension and desaturation after tracheal extubation, and higher patient satisfaction. Time to tracheal extubation was prolonged slightly in the opioid-free group. The two groups had similar postoperative pain scores and 30-day outcomes.DiscussionOpioid-free propofol anaesthesia reduced postoperative nausea and vomiting in patients undergoing thyroid and parathyroid surgery. An opioid-free anaesthetic regimen can optimise anaesthetic care during thyroid and parathyroid surgery
Impaired expression of neuronal nitric oxide synthase in the gracile nucleus is involved in neuropathic changes in Zucker Diabetic Fatty rats with and without 2,5-hexanedione intoxication
These studies examined the influence of 2,5-hexanedione (2,5-HD) intoxication on expression of neuronal nitric oxide synthase (nNOS) in the brainstem nuclei in Zucker Diabetic Fatty (ZDF) vs. lean control (LC) rats. Functional neuropathic changes were also investigated following axonal damage and impaired axonal transport induced by the treatment. Animals were intoxicated by i.p. injection of 2,5-HD plus unilateral administration of 2,5-HD over the sciatic nerve. The mechanical thresholds and withdrawal latencies to heat and cold stimuli on the foot were measured at baseline and after intoxication. The medulla sections were examined by nNOS immunohistochemistry and NADPH-diaphorase histochemistry at the end of the treatments. The mechanical thresholds and withdrawal latencies were significantly decreased while nNOS immunostained neurons and NADPH-diaphorase positive cells were selectively reduced in the gracile nucleus at baseline in ZDF vs. LC rats. NADPH-diaphorase reactivity and nNOS positive neurons were increased in the ipsilateral gracile nucleus in LC rats following 2,5-HD intoxication, but its up-regulation was attenuated in ZDF rats. These results suggest that diabetic and chemical intoxication-induced nNOS expression is selectively reduced in the gracile nucleus in ZDF rats. Impaired axonal damage-induced nNOS expression in the gracile nucleus is involved in neuropathic pathophysiology in type II diabetic rats
De novo characterization of a whitefly transcriptome and analysis of its gene expression during development
<p>Abstract</p> <p>Background</p> <p>Whitefly (<it>Bemisia tabaci</it>) causes extensive crop damage throughout the world by feeding directly on plants and by vectoring hundreds of species of begomoviruses. Yet little is understood about its genes involved in development, insecticide resistance, host range plasticity and virus transmission.</p> <p>Results</p> <p>To facilitate research on whitefly, we present a method for <it>de novo </it>assembly of whitefly transcriptome using short read sequencing technology (Illumina). In a single run, we produced more than 43 million sequencing reads. These reads were assembled into 168,900 unique sequences (mean size = 266 bp) which represent more than 10-fold of all the whitefly sequences deposited in the GenBank (as of March 2010). Based on similarity search with known proteins, these analyses identified 27,290 sequences with a cut-off E-value above 10<sup>-5</sup>. Assembled sequences were annotated with gene descriptions, gene ontology and clusters of orthologous group terms. In addition, we investigated the transcriptome changes during whitefly development using a tag-based digital gene expression (DGE) system. We obtained a sequencing depth of over 2.5 million tags per sample and identified a large number of genes associated with specific developmental stages and insecticide resistance.</p> <p>Conclusion</p> <p>Our data provides the most comprehensive sequence resource available for whitefly study and demonstrates that the Illumina sequencing allows <it>de novo </it>transcriptome assembly and gene expression analysis in a species lacking genome information. We anticipate that next generation sequencing technologies hold great potential for the study of the transcriptome in other non-model organisms.</p
Network Pharmacology-based Research on Lipid Lowering Mechanism of Walnut Cold-press Meal
This paper explores the action mechanism of walnut cold-press meal in reducing fat from the perspective of network pharmacology.Active components and potential targets of walnut cold-press meal were obtained through TCMSP database and literature mining.GeneCards and other databases were used to predict and screen Hyperlipidemia (HLP) related genes,while Cytoscape 3.7.2 software was applied to construct a âdrug-active component-disease-targetâ network to the formation of walnuts to prevent HLP components and target interactions,and analysis of GO function and KEGG pathway enrichment.Results show that 14 active components of Walnut cold-press meal were identified,among which 7 components have 59 HLP-related targets.HAS2,NCOA2,ESR1,CAT,AR,VEGFA and POR may be the key targets of HLP,with the main signaling pathways being HIF-1 signaling pathway,TNF signaling pathway,Chagas disease,and malaria signaling pathway.HLP is prevented by multi-component,multi-target and multi-pathway,among which the most targeted components are quercetin,rutin,catechin,erucic acid and ellagic acid.Targets most affected by the compounds are hyaluronate synthase 2,nuclear receptor coactivator factor 2,estrogen receptor,catalase,androgen receptor,vascular endothelial growth factor A and NHLPPH--cytochrome P450 reductase
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