710 research outputs found

    Clinical applications of B-type natriuretic peptide (BNP) testing

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    Many claims have been made in recent years regarding the utility of plasma B-type natriuretic peptide (BNP) concentration measurements in the diagnosis, risk stratification and monitoring of patients with heart failure. This paper summarizes the current evidence and provides guidance for practising clinicians. Overall, plasma BNP testing appears to be of most value in the diagnostic arena, where it is likely to improve the performance of non-specialist physicians in diagnosing heart failure. In clinical practice, BNP testing is best used as a ‘rule out' test for suspected cases of new heart failure in breathless patients presenting to either the outpatient or emergency care settings; it is not a replacement for echocardiography and full cardiological assessment, which will be required for patients with an elevated BNP concentration. Although work is ongoing in establishing the ‘normal' values of BNP, heart failure appears to be highly unlikely below a plasma concentration of 100pg/ml. However, as BNP levels rise with age and are affected by gender, comorbidity and drug therapy, the plasma BNP measurement should not be used in isolation from the clinical contex

    NANOCRYSTALLINE MAGNETITE - Fe₃O₄ PARTICLES SYNTHESIZED BY MECHANICAL MILLING

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    Nanocrystalline magnetite – Fe3O4 has been synthesized in nanocrystalline state by mechanical milling of well crystallized magnetite samples obtained by heat treatment of a stoichiometric mixture of iron and hematite. Upon increasing the milling time, the mean crystallite size of magnetite is diminishing. After only 5 minutes of mechanical milling the crystallites are 110 nm. The milling up to 120 minutes leads to a continuous reduction of crystallites size up to 8 nm. The mechanical milling process induces strains into the lattice and the lattice strains increase drastically in the first 60 minutes of milling, after that a saturation of lattice strains is noticed. During milling a contamination of the powder with elemental iron occurs for milling times larger than 30 minutes. A decrease of the saturation magnetisation is noticed upon increasing the milling time and the decrease is associated with the structural disorder and defects that are induced into the material during milling. A tendency of the magnetisation to become unsaturated is also noticed and it is related to canted spins effect

    SOFT MAGNETIC NANOCRYSTALLINE Ni-Fe-X-Y AND MeFe₂O₄ POWDERS OBTAINED BY MECHANOSYNTHESIS

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    The soft magnetic nanocrystalline powders, alloys (Ni3Fe, 79Ni16Fe5Mo, 77Ni14Fe5Cu4Mo, wt. %) and zinc ferrite, were obtained by dry and wet mechanical alloying and reactive milling, followed by different heat treatments. The powders were characterised by X-ray diffraction, scanning electron microscopy, X-ray microanalysis, differential scanning calorimetry, thermomagnetic and magnetic measurements. The X-ray diffraction shown the progressive new phases formation. The crystallite size is between 18-7 nm depending on materials and milling conditions. The particle size is smaller for wet-mechanical alloying comparing with dry-milling. The thermomagnetic measurement shown the Curie temperature of the alloys. The spontaneous magnetisation of the wet-milled and annealed samples is higher than of the molten alloys

    Identification of metabolic pathways influenced by the G-protein coupled receptors GprB and GprD in Aspergillus nidulans

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    Heterotrimeric G-protein-mediated signaling pathways play a pivotal role in transmembrane signaling in eukaryotes. Our main aim was to identify signaling pathways regulated by A. nidulans GprB and GprD G-protein coupled receptors (GPCRs). When these two null mutant strains were compared to the wild-type strain, the DeltagprB mutant showed an increased protein kinase A (PKA) activity while growing in glucose 1% and during starvation. In contrast, the DeltagprD has a much lower PKA activity upon starvation. Transcriptomics and (1)H NMR-based metabolomics were performed on two single null mutants grown on glucose. We noted modulation in the expression of 11 secondary metabolism gene clusters when the DeltagprB and DeltagprD mutant strains were grown in 1% glucose. Several members of the sterigmatocystin-aflatoxin gene cluster presented down-regulation in both mutant strains. The genes of the NR-PKS monodictyphenone biosynthesis cluster had overall increased mRNA accumulation in DeltagprB, while in the DeltagprD mutant strain the genes had decreased mRNA accumulation. Principal component analysis of the metabolomic data demonstrated that there was a significant metabolite shift in the DeltagprD strain. The (1)H NMR analysis revealed significant expression of essential amino acids with elevated levels in the DeltagprD strain, compared to the wild-type and DeltagprB strains. With the results, we demonstrated the differential expression of a variety of genes related mainly to secondary metabolism, sexual development, stress signaling, and amino acid metabolism. We propose that the absence of GPCRs triggered stress responses at the genetic level. The data suggested an intimate relationship among different G-protein coupled receptors, fine-tune regulation of secondary and amino acid metabolisms, and fungal development

    Séparation et spéciation des éléments dans des échantillons nucléaires par couplage entre l'électrophorèse capillaire et la spectrométrie de masse à source plasma et à multicollection

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    International audienceLa détermination précise des compositions élémentaires et isotopiques dans des échantillons nucléaires est indispensable pour la gestion des combustibles nucléaires et des déchets radioactifs. Cette détermination isotopique et élémentaire porte notamment sur l'uranium, le plutonium et les lanthanides et est effectuée par spectrométrie de masse après séparations chimiques afin d’éliminer les interférences isobariques. L'Électrophorèse capillaire est une technique séparative particulièrement attractive pour ces applications, du fait des très hautes efficacités, des courts temps d'analyse et des micro volumes mis en jeu. Des études menées précédemment au laboratoire ont démontré la faisabilité de séparations U/Pu/Lanthanides et de séparations U/Th en utilisant un électrolyte d'acide acétique et en couplage direct avec un spectromètre de masse Multi-collecteurs a source plasma. La complexité et la diversité des échantillons nucléaires imposent un suivi de la spéciation des éléments d’intérêts dans les conditions développées afin de garantir le succès des analyses. L’étude de spéciation qui sera présentée ici a permis d'expliquer les facteurs influençant le comportement électro-optique des éléments d’intérêt. Ces études de spéciation peuvent être étendues a d'autres électrolytes afin de développer des séparations pour les éléments présents dans les échantillons nucléaires

    Long term surgical results of 154 petroclival meningiomas: A retrospective multicenter study

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    BACKGROUND: Outcomes of petroclival meningiomas (PCM) (morbidity, permanent cranial nerves deficit, tumor removal and recurrence) are inconsistent in the literature, making it a challenge to predict surgical morbidity. METHODS: A multicenter study of patients with PCMs larger than 2.5cm between 1984 and 2017 was conducted. The authors retrospectively reviewed the patients\u27 medical records, imaging studies and pathology reports to analyze presentation, surgical approach, neurological outcomes, complications, recurrence rates and predictive factors. RESULTS: There were 154 patients. The follow-up was 76.8 months on average (range 8-380 months). Gross total resection (GTR) was achieved in 40 (26.0%) patients, subtotal resection (STR) in 101 (65.6%), and partial resection in 13 (8.3%). Six (2.6%) perioperative deaths occurred. The 5-year, 10-year and 15-year progression-free survival (PFS) of GTR and STR with radiation therapy (RT) was similar (100%, 90% and 75%). PFS of STR without adjuvant radiation was associated with progression in 71%, 51% and 31%, respectively. Anterior petrosectomy and combined petrosectomy were associated with higher postoperative CN V and CN VI deficits compared to the retrosigmoid approach. The latter had a significantly higher risk of CN VII, CN VIII and LCN deficit. Temporal lobe dysfunction (seizure and aphasia) were significantly associated with the anterior petrosectomy approach. CONCLUSIONS: Our study shows that optimal subtotal resection of PCMs associated with postoperative RT or stereotactic radiosurgery results in long-term tumor control to equivalent radical surgery. Case selection and appropriate intraoperative judgement are required to reduce the morbidity

    Effect of aliskiren on post-discharge outcomes among diabetic and non-diabetic patients hospitalized for heart failure: insights from the ASTRONAUT trial

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    Aims The objective of the Aliskiren Trial on Acute Heart Failure Outcomes (ASTRONAUT) was to determine whether aliskiren, a direct renin inhibitor, would improve post-discharge outcomes in patients with hospitalization for heart failure (HHF) with reduced ejection fraction. Pre-specified subgroup analyses suggested potential heterogeneity in post-discharge outcomes with aliskiren in patients with and without baseline diabetes mellitus (DM). Methods and results ASTRONAUT included 953 patients without DM (aliskiren 489; placebo 464) and 662 patients with DM (aliskiren 319; placebo 343) (as reported by study investigators). Study endpoints included the first occurrence of cardiovascular death or HHF within 6 and 12 months, all-cause death within 6 and 12 months, and change from baseline in N-terminal pro-B-type natriuretic peptide (NT-proBNP) at 1, 6, and 12 months. Data regarding risk of hyperkalaemia, renal impairment, and hypotension, and changes in additional serum biomarkers were collected. The effect of aliskiren on cardiovascular death or HHF within 6 months (primary endpoint) did not significantly differ by baseline DM status (P = 0.08 for interaction), but reached statistical significance at 12 months (non-DM: HR: 0.80, 95% CI: 0.64-0.99; DM: HR: 1.16, 95% CI: 0.91-1.47; P = 0.03 for interaction). Risk of 12-month all-cause death with aliskiren significantly differed by the presence of baseline DM (non-DM: HR: 0.69, 95% CI: 0.50-0.94; DM: HR: 1.64, 95% CI: 1.15-2.33; P < 0.01 for interaction). Among non-diabetics, aliskiren significantly reduced NT-proBNP through 6 months and plasma troponin I and aldosterone through 12 months, as compared to placebo. Among diabetic patients, aliskiren reduced plasma troponin I and aldosterone relative to placebo through 1 month only. There was a trend towards differing risk of post-baseline potassium ≥6 mmol/L with aliskiren by underlying DM status (non-DM: HR: 1.17, 95% CI: 0.71-1.93; DM: HR: 2.39, 95% CI: 1.30-4.42; P = 0.07 for interaction). Conclusion This pre-specified subgroup analysis from the ASTRONAUT trial generates the hypothesis that the addition of aliskiren to standard HHF therapy in non-diabetic patients is generally well-tolerated and improves post-discharge outcomes and biomarker profiles. In contrast, diabetic patients receiving aliskiren appear to have worse post-discharge outcomes. Future prospective investigations are needed to confirm potential benefits of renin inhibition in a large cohort of HHF patients without D

    Rapport préliminaire sur les activités de la mission archéologique franco-syrienne dans la micro-région d'Al-Rawda (Shamiyeh) : quatrième et cinquième campagnes (2005 et 2006)

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    This preliminary report presents the results of two campaigns of excavation and survey in 2005and 2006 on the site of AI-Rawda (West-Central Syria) and in the micro-region of 100 km2 around it. Thesite is a pre-planned circular new town. It was founded around 2400 BCE, in the steppe zone and was inhabitedonly during EB IV, until the end of the 3rd millennium. The work of 2005 and 2006 involved furtherextensive excavation of a sanctuary consisting of two temples and a temenos togeiher with aIl associatedinstallations (including a betyl in situ). The eastem gate of the town was excavated and four lines of defencehave been identified. A stratigraphie sounding in the southwest clarifies the origin of the town. In the necropolisassociated with the site, the excavation of a collective pit burial is presented. Intensive survey wascontinued outside the ancient town, with particular attention to sites that were occupied at the same time asAI-Rawda, to burials, which have been classified by type, and to installations that can be linked to agricultureor pastoralism. This work was supplemented by archaeobotanical, archaeozoological and geo-archaeologicalresearch, as weIl as a study of the environment.Ce rapport préliminaire présente les résultats de deux campagnes de fouilles et de prospection conduites en 2005 et 2006 sur le site d’Al-Rawda (Syrie du centre-ouest) et dans la microrégion de 100 km2 qui l’entoure. Le site, une ville neuve circulaire au plan d’urbanisme préconçu fondé vers 2500 av. J.-C., se trouve en zone steppique. Il n’est habité que durant le Bronze ancien IV, jusqu’à la fin du 3e millénaire.Les travaux en 2005 et 2006 ont porté sur la poursuite du dégagement extensif d’un sanctuaire qui regroupe deux temples et un temenos, avec l’ensemble des installations qu’ils contiennent (dont un bétyle in situ). À l’est, a été mise au jour la porte orientale de la ville tandis que quatre lignes de défense ont été identifiées. Un sondage stratigraphique au sud-ouest éclaire l’origine de la ville. Dans la nécropole associée au site, la fouille d’une tombe en puits collective est présentée.Parallèlement, la prospection intensive autour de la ville antique a été poursuivie en mettant l’accent sur les sites d’habitat contemporains d’Al-Rawda, les tombes caractérisées par type et les aménagements qui peuvent être liés à une mise en valeur agricole du territoire et au pastoralisme. Ces travaux ont été complétés par des études archéobotanique, archéozoologique, géoarchéologique et par une étude des milieux

    Stuttered swallowing: Electric stimulation of the right insula interferes with water swallowing. A case report

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    <p>Abstract</p> <p>Background</p> <p>Various functional resonance imaging, magnetoencephalographic and lesion studies suggest the involvement of the insular cortex in the control of swallowing. However, the exact location of insular activation during swallowing and its functional significance remain unclear.</p> <p>Case presentation</p> <p>Invasive electroencephalographic monitoring was performed in a 24-year-old man with medically intractable stereotyped nocturnal hypermotor seizures due to a ganglioglioma. During stimulation of the right inferior posterior insular cortex with depth electrodes the patient spontaneously reported a perception of a "stutter in swallowing". Stimulation of the inferior posterior insular cortex at highest intensity (4 mA) was also associated with irregular and delayed swallows. Swallowing was not impaired during stimulation of the superior posterior insular cortex, regardless of stimulation intensity.</p> <p>Conclusions</p> <p>These results indicate that the right inferior posterior insular cortex is involved in the neural circuitry underlying the control of swallowing.</p

    Advances in heterometallic ring-opening (co)polymerisation catalysis

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    Truly sustainable plastics require renewable feedstocks coupled with efficient production and end-of-life degradation/recycling processes. Some of the most useful degradable materials are aliphatic polyesters, polycarbonates and polyamides, which are often prepared via ring-opening (co)polymerisation (RO(CO)P) using an organometallic catalyst. While there has been extensive research into ligand development, heterometallic cooperativity offers an equally promising yet underexplored strategy to improve catalyst performance, as heterometallic catalysts often exhibit significant activity and selectivity enhancements compared to their homometallic counterparts. This review describes advances in heterometallic RO(CO)P catalyst design, highlighting the overarching structure-activity trends and reactivity patterns to inform future catalyst design
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