5,648 research outputs found
On unitary convex decompositions of vectors in a -algebra
No full textsummary:By exploiting his recent results, the author further investigates the extent to which variation in the coefficients of a unitary convex decomposition of a vector in a unital -algebra permits the vector decomposable as convex combination of fewer unitaries; certain -algebra results due to M. Rørdam have been extended to the general setting of -algebras
Diagnosis and treatment of paraneoplastic neurological disorders
No full textIn about two thirds of cases, patients with paraneoplastic neurological disorders present to the neurologist without a known tumor. Due to the ongoing immune response, this tumor tends to stay biologically relatively benign, and therefore difficult to diagnose. In patients with a known tumor, the neurological symptoms often precede a tumor recurrence. In both scenarios, anti-neuronal antibodies are an invaluable diagnostic help to the clinician, and may be supplemented by other diagnostic tests such as MRI, CSF, and electrophysiology. Tumor therapy remains the mainstay of therapeutic options, although early immune therapy must be started in parallel. It is hoped that the recent fundamental advances in understanding the autoimmune pathology of these disorders, especially the role of cytotoxic T cells, will eventually lead to more effective treatment options
Contrast-enhanced CMR in patients after percutaneous closure of the left atrial appendage: A pilot study
No full textAbstract Background To evaluate the feasibility and value of first-pass contrast-enhanced dynamic and post-contrast 3D CMR in patients after transcatheter occlusion of left atrial appendage (LAA) to identify incorrect placement and persistent leaks. Methods 7 patients with different occluder systems (n = 4 PLAATO; n = 2 Watchman; n = 1 ACP) underwent 2 contrast-enhanced (Gd-DOTA) CMR sequences (2D TrueFISP first-pass perfusion and 3D-TurboFLASH) to assess localization, artifact size and potential leaks of the devices. Perfusion CMR was analyzed visually and semi-quantitatively to identify potential leaks. Results All occluders were positioned within the LAA. The ACP occluder presented the most extensive artifact size. Visual assessment revealed a residual perfusion of the LAA apex in 4 cases using first-pass perfusion and 3D-TurboFLASH indicating a suboptimal LAA occlusion. By assessing signal-to-time-curves the cases with a visually detected leak showed a 9-fold higher signal-peak in the LAA apex (567 ± 120% increase from baseline signal) than those without a leak (61 ± 22%; p Conclusion This CMR pilot study provides valuable non-invasive information in patients after transcatheter occlusion of the LAA to identify correct placement and potential leaks. We recommend incorporating CMR in future clinical studies to evaluate new device types.</p
Detonation reaction-zone structure of JB-9014
No full textThe structure of reaction-zone of JB-9014 explosive was investigated using photoelectric technique. For one dimensional steady detonation wave of JB-9014 (1.894 g/cm3), the Neumann spike pressure was 36.5 GPa, the width of reaction-zone was 1.75 mm, and the period of reaction was 0.31 μs. It is found that the width of reaction-zone and the period of reaction decrease with the explosive density
One of the two genes encoding nucleoid-associated HU proteins in Streptomyces coelicolor is developmentally regulated and specifically involved in spore maturation.
No full textStreptomyces genomes encode two homologs of the nucleoid-associated HU-proteins. One of them, here designated HupA, is of a conventional type similar to E. coli HUalpha and HUbeta, while the other, HupS, is a two-domain protein. In addition to the N-terminal part that is similar to HU proteins, it has an additional C-terminal domain that is similar to the alanine and lysine-rich C-termini of eukaryotic linker histones. Such two-domain HU proteins are only found among Actinobacteria. In this phylum some organisms have only a single HU-protein of this type with a C-terminal histone H1-like domain (e. g. Hlp in Mycobacterium smegmatis), while others have only a single conventional HU. Yet others, including the streptomycetes, produce both types of HU-proteins. We show here that the two HU-genes in Streptomyces coelicolor are differentially regulated and that hupS is specifically expressed during sporulation, while hupA is expressed in vegetative hyphae. The developmental upregulation of hupS occurred in sporogenic aerial hyphal compartments, and was dependent on the developmental regulators whiA, whiG, and whiI. HupS was found to be nucleoid-associated in spores, and a hupS deletion mutant had larger average nucleoid size in spores compared to the parent strain. The mutant spores were also defective in heat resistance and spore pigmentation, although they showed apparently normal spore walls and displayed no increased sensitivity to detergents. Overall, the results show that HupS is specifically involved in sporulation and may affect nucleoid architecture and protection in spores of S. coelicolor
The Histone-Like Protein HU Does Not Obstruct Movement of T7 RNA Polymerase in Escherichia coli Cells but Stimulates Its Activity
No full textIn vivo, RNA polymerases (RNAPs) do not transcribe naked DNA but do transcribe protein-associated DNA. Studies with the model enzyme T7 RNAP have shown that, in eukaryotic cells or in vitro, nucleosomes can inhibit both transcription initiation and elongation. We examine here whether the presence of HU, one of the major histone-like proteins in Escherichia coli cells (the genuine milieu for T7 RNAP) affects its activity. An engineered lac operon fused to the T7 late promoter was introduced into the chromosome of T7 RNAP-producing strains that either overexpress HU or lack it. The flows of RNAP that enter and exit this operon were compared with regard to the content of HU. We found that the fraction of T7 RNAP molecules that do not reach the end of the lac operon (ca. 15%) is the same whether the host cells overexpressed HU or lacked it: thus, the enzyme either freely displaces HU or transcribes through it. However, in these cells, the transcript yield was increased when HU is overexpressed and decreased in the hup mutants, presumably reflecting changes in DNA supercoiling. Thus, in contrast to eukaryotic nucleosomes, HU does not impair T7 RNAP activity but has a stimulatory effect. Finally, our results suggest that HU can also influence mRNA stability in vivo.P.M. was supported by postdoctoral fellowships from the Ministère de Affaires Etrangères and from the Fondation pour la Recherche Médicale. This work was funded by the Association de la Recherche contre le Cancer (ARC 5376 and 5474), the Action “Interface Chimie-Physique-Biologie” du Ministère de l'Enseignement Supérieur et de la Recherche (AAC-SV-1995) and the Action Concertée CNRS-ARC 1995 (“Interactions Protéine-protéine”), and by MNERT grants “Recherche Fondamentale en Microbiologie, Maladies Infectieuses et Parasitaires” to J.R.-Y. and M.D.Peer reviewe
Erratum: Half-supersymmetric solutions in five-dimensional supergravity (Journal of High Energy Physics (2007) 12 (025))
No full text[No abstract available]Gutowski JB, 2007, J HIGH ENERGY PHYS11
Fan the flame: trazodone-induced mania in a unipolar depressed patient with stable sertraline treatment
No full textJianbo Hu,1,2,* Jianbo Lai,1,2,* Hanzhi Zheng,3 Shaohua Hu,1,2 Yi Xu1,2 1Department of Psychiatry, First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China; 2The Key Laboratory of Mental Disorder’s Management in Zhejiang Province, Hangzhou, China; 3Department of Clinical Medicine, Zhejiang University School of Medicine, Hangzhou, China *These authors contributed equally to this work Abstract: Depressed patients often complain of sleep disturbance. Routine antidepressive strategies sometimes fail to deal with this intractable issue. Indeed, the supplementation of sleep promoting antidepressants (eg, trazodone, mirtazapine, and agomelatine) is prevalent in clinical practice. However, the combination of different antidepressants may increase the affective lability. Herein, we document a patient with unipolar depression who was compliant with sertraline treatment and who dramatically switched to mania after adding trazodone as a sleeping aid. This case extended our understanding of the potential manic-switching risk when trazodone is used to promote sleep. Keywords: trazodone, sertraline, depression, mani
Scopolamine alleviates involuntary lingual movements: tardive dyskinesia or dystonia?
No full textJianbo Hu,1,2,* Jianbo Lai,1,2,* Shaohua Hu,1,2 Yi Xu1,2 1Department of Psychiatry, First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China; 2The Key Laboratory of Mental Disorder’s Management in Zhejiang Province, Hangzhou, China *These authors contributed equally to this work Abstract: Cholinergic hypofunction was believed to be associated with the pathogenesis of tardive dyskinesia, and therefore, anticholinergic treatment might exacerbate the condition. We describe herein a middle-aged male with feeble chewing movements, involuntary rolling motions of the tongue, and abnormally tightened cheeks which developed after consuming different psychotropic medications. These symptoms did not improve after routine treatment for tardive dyskinesia, but responded well to anticholinergic agents, such as scopolamine and benzhexol hydrochloride. This case extended our understanding of the complexity of extrapyramidal effects and their pharmacologic management. Keywords: neuroleptic, scopolamine, tardive dyskinesia, dystoni
Coactivation in vitro of the σ54-dependent promoter Pu of the TOL plasmid of Pseudomonas putida by HU and the mammalian HMG-1 protein
No full textThe mechanism by which the prokaryotic histone-like protein HU replaces the integration host factor (IHF) in the coactivation of the σ54-dependent promoter Pu of Pseudomonas putida has been investigated. By using a preactivated form of the cognate activator protein XyIR, we show that the functional replacement of IHF with HU previously suggested in vivo can be faithfully reproduced in vitro with purified components. Furthermore, the coactivation effect of IHF on Pu could be mimicked not only by HU but also by the mammalian nonhistone chromatin protein HMG-1 and could be bypassed by intrinsically curved DNA. These results suggest that either of two different mechanisms (generation of a site-specific static DNA bend or a general flexibilization of the promoter region) gives rise to the same structural effect of stimulating transcription from Pu through changes in promoter architecture.This research was financed by the Spanish Comisio ́n Interministerial de Ciencia y Tecnologı ́a, grant BIO95-0788, and contract ENV4-CT95-0141 of the Commission of the European Unio
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