4,196 research outputs found

    An HI study of the collisional ring galaxy NGC 922

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    We present new atomic hydrogen (HI) observations of the collisional ring galaxy NGC 922 obtained using the Australia Telescope Compact Array. Our observations reveal for the first time the vast extent of the HI disc of this galaxy. The HI morphology and kinematics of NGC 922 show that this galaxy is not the product of a simple drop-through interaction, but has a more complex interaction history. The integrated HI flux density of NGC 922 from our observations is 24.7 Jy km s1^{-1}, which is within the error of the flux value obtained using the 6464-m Parkes radio telescope. This flux density translates to a total HI mass of 1.110101.1*10^{10} M_{\circ} and corresponds to an HI to total mass fraction (MHI_{HI}/Mtot_{tot}) of approximately 0.110.11. The gaseous structures of NGC 922 are more extended to the north and include an HI tail that has a projected physical length of 88 kpc. Gas warps are also evident in the velocity field of NGC 922 and are more prominent on the approaching and the western side of the disc. In comparison with a large sample of star-forming galaxies in the local Universe, NGC 922 possesses a high gas fraction relative to galaxies with a similar stellar mass of ~1010.410^{10.4} M_{\circ}, and exhibits a high specific star formation rate.Comment: 11 pages, 8 figures, published in MNRA

    A novel role for Lyl1 in primitive erythropoiesis

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    © 2018. Published by The Company of Biologists Ltd. Stem cell leukemia (Scl or Tal1) and lymphoblastic leukemia 1 (Lyl1) encode highly related members of the basic helix-loop-helix family of transcription factors that are co-expressed in the erythroid lineage. Previous studies have suggested that Scl is essential for primitive erythropoiesis. However, analysis of single-cell RNA-seq data of early embryos showed that primitive erythroid cells express both Scl and Lyl1. Therefore, to determine whether Lyl1 can function in primitive erythropoiesis, we crossed conditional Scl knockout mice with mice expressing a Cre recombinase under the control of the Epo receptor, active in erythroid progenitors. Embryos with 20% expression of Scl from E9.5 survived to adulthood. However, mice with reduced expression of Scl and absence of Lyl1 (double knockout; DKO) died at E10.5 because of progressive loss of erythropoiesis. Gene expression profiling of DKO yolk sacs revealed loss of Gata1 and many of the known target genes of the SCL-GATA1 complex. ChIP-seq analyses in a human erythroleukemia cell line showed that LYL1 exclusively bound a small subset of SCL targets including GATA1. Together, these data show for the first time that Lyl1 can maintain primitive erythropoiesis

    Comparative effectiveness of dipeptidyl peptidase-4 (DPP-4) inhibitors and human glucagon-like peptide-1 (GLP-1) analogue as add-on therapies to sulphonylurea among diabetes patients in the Asia-Pacific region: a systematic review

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    The prevalence of diabetes mellitus is rising globally, and it induces a substantial public health burden to the healthcare systems. Its optimal control is one of the most significant challenges faced by physicians and policy-makers. Whereas some of the established oral hypoglycaemic drug classes like biguanide, sulphonylureas, thiazolidinediones have been extensively used, the newer agents like dipeptidyl peptidase-4 (DPP-4) inhibitors and the human glucagon-like peptide-1 (GLP-1) analogues have recently emerged as suitable options due to their similar efficacy and favorable side effect profiles. These agents are widely recognized alternatives to the traditional oral hypoglycaemic agents or insulin, especially in conditions where they are contraindicated or unacceptable to patients. Many studies which evaluated their clinical effects, either alone or as add-on agents, were conducted in Western countries. There exist few reviews on their effectiveness in the Asia-Pacific region. The purpose of this systematic review is to address the comparative effectiveness of these new classes of medications as add-on therapies to sulphonylurea drugs among diabetic patients in the Asia-Pacific countries. We conducted a thorough literature search of the MEDLINE and EMBASE from the inception of these databases to August 2013, supplemented by an additional manual search using reference lists from research studies, meta-analyses and review articles as retrieved by the electronic databases. A total of nine randomized controlled trials were identified and described in this article. It was found that DPP-4 inhibitors and GLP-1 analogues were in general effective as add-on therapies to existing sulphonylurea therapies, achieving HbA1c reductions by a magnitude of 0.59–0.90% and 0.77–1.62%, respectively. Few adverse events including hypoglycaemic attacks were reported. Therefore, these two new drug classes represent novel therapies with great potential to be major therapeutic options. Future larger-scale research should be conducted among other Asia-Pacific region to evaluate their efficacy in other ethnic groups

    Speech and language deficits are central to SETBP1 haploinsufficiency disorder

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    Expressive communication impairment is associated with haploinsufficiency of SETBP1, as reported in small case series. Heterozygous pathogenic loss-of-function (LoF) variants in SETBP1 have also been identified in independent cohorts ascertained for childhood apraxia of speech (CAS), warranting further investigation of the roles of this gene in speech development. Thirty-one participants (12 males, aged 0; 8-23; 2 years, 28 with pathogenic SETBP1 LoF variants, 3 with 18q12.3 deletions) were assessed for speech, language and literacy abilities. Broader development was examined with standardised motor, social and daily life skills assessments. Gross and fine motor deficits (94%) and intellectual impairments (68%) were common. Protracted and aberrant speech development was consistently seen, regardless of motor or intellectual ability. We expand the linguistic phenotype associated with SETBP1 LoF syndrome (SETBP1 haploinsufficiency disorder), revealing a striking speech presentation that implicates both motor (CAS, dysarthria) and language (phonological errors) systems, with CAS (80%) being the most common diagnosis. In contrast to past reports, the understanding of language was rarely better preserved than language expression (29%). Language was typically low, to moderately impaired, with commensurate expression and comprehension ability. Children were sociable with a strong desire to communicate. Minimally verbal children (32%) augmented speech with sign language, gestures or digital devices. Overall, relative to general development, spoken language and literacy were poorer than social, daily living, motor and adaptive behaviour skills. Our findings show that poor communication is a central feature of SETBP1 haploinsufficiency disorder, confirming this gene as a strong candidate for speech and language disorders

    Metal–organic frameworks in proton-exchange membrane for intermediate-to-high-temperature fuel-cell applications: a review

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    A proton-exchange membrane (PEM) is a vital component in fuel cells as a solid electrolyte that conducts ions. The high cost and degradation of Nafion® membrane in low-temperature fuel cells limits the technology’s commercialization. The development of intermediate (IT-PEMFCs) to high-temperature (HT-PEMFCs) fuel cells operating within the range of 80–200 °C has made progress over the last few decades, and improvements in water management addressing the issues of low-temperature PEMFCs have been observed. However, these types of PEM fuel cells (IT-PEMFCs and HT-PEMFCs) still face considerable challenges, such as unsatisfactory performance stability at high temperatures. Particularly, in HT-PEMFC, despite the high acid doping level (ADL) in membranes as a potential means to improve proton conductivity, high ADL decreases the membrane’s mechanical stability. Recently, metal–organic frameworks (MOFs) have achieved satisfactory results in applications of PEM modification. This manuscript reviews the development in applying MOFs in improving the properties of composite membranes in IT- and HT-PEMFCs by using SPEEK and PBI, respectively. The synthesis strategies using MOFs in the PEM are discussed together with the electrochemical properties obtained. The success of incorporating of MOFs into PEMs could shed light on the synthesis of new-generation IT- and HT-PEMFCs, which could improve several properties such as mechanical and thermal stability, oxidative stability, and acid-retention capacity

    A novel technique for the treatment of post operative retro-rectal haematoma: two case reports

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    Rectal bleeding following any form of rectal surgery is a well recognised complication 1, 2, 3 & 4. However retro-rectal bleeding and tracking which then presents as rectal bleeding has not been reported in the literature. We describe a novel way of dealing with this technically difficult post-operative complication

    Anesthetic experience of an adult patient with an unrecognized tracheal bronchus -A case report-

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    We present a case of problematic tracheal intubation in an adult patient with an unrecognized tracheal bronchus. Immediately after tracheal intubation and position change to prone, bilateral breath sounds were almost absent, and there was a diminished tidal volume. In order to resolve the ventilatory difficulty, the wire-reinforced tube was replaced with a conventional tube, and proper positioning of the tube was completed under fiberoptic guidance. A tracheal bronchus (originating about 1.2 cm above the carina, and supplying the right upper lobe) was found on the postoperative chest CT. In the presence of tracheal bronchus, tracheal intubation may cause pulmonary complications. Anesthesiologists should keep in mind the anesthetic implications of tracheal bronchus, and must be familiar with the use of fiberoptic bronchoscopy for proper positioning of endotracheal tube

    iCartiGD: the Integrated Cartilage Gene Database

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    BACKGROUND: Diseases of cartilage, such as arthritis and degenerative disc disease, affect the majority of the general population, particularly with ageing. Discovery and understanding of the genes and pathways involved in cartilage biology will greatly assist research on the development, degeneration and disorders of cartilage. DESCRIPTION: We have established the Integrated Cartilage Gene Database (iCartiGD) of genes that are known, based on results from high throughput experiments, to be expressed in cartilage. Information about these genes is extracted automatically from public databases and presented as a single page report via a web-browser. A variety of flexible search options are provided and the chromosomal distribution of cartilage associated genes can be presented. CONCLUSION: iCartiGD provides a comprehensive source of information on genes known to be expressed in cartilage. It will remain current due to its automatic update capability and provide researchers with an easily accessible resource for studies involving cartilage. Genetic studies of the development and disorders of cartilage will benefit from this database
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