61 research outputs found

    Triple and Quadruple Black Holes in the ASTRID Simulation at z2z \sim 2

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    We use the ASTRID cosmological hydrodynamic simulation to investigate the properties and evolution of triple and quadruple Massive Black Hole (MBH) systems at z=23z = 2-3. Only a handful of MBH tuple systems have been detected to date. In ASTRID, we find 4%4\% of the MBH>107MM_{\rm BH}>10^7\,M_\odot are in tuples with Δrmax<200kpc\Delta r_{\rm max} < 200\,{\rm kpc}. The tuple systems span a range of separations with the majority of the observable AGN systems at Δr50100\Delta r \sim 50-100 kpc. They include some of the most massive BHs (up to 1010M10^{10} \,M_\odot) but with at least one of the components of MBH107MM_{\rm BH} \sim 10^7 \,M_\odot. Tuples' host galaxies are typically massive with M101011MM_* \sim 10^{10-11} \,M_\odot. We find that >10%>10\% massive halos with Mhalo>1013MM_{\rm halo} > 10^{13} M_\odot host MBH tuples. Following the subsequent interactions between MBHs in tuples, we found that in 5%\sim 5\% of the triplets all three MBHs merge within a Gyr, and 15%15\% go through one merger. As a by-product of the complex multi-galaxy interaction of these systems, we also find that up to 5%\sim 5\% of tuples lead to runaway MBHs. In ASTRID, virtually all of the ultramassive black holes (>1010M>10^{10} \,M_\odot ) have undergone a triple quasar phase while for BHs with MBH109MM_{\rm BH} \sim 10^9 \,M_\odot this fraction drops to 50%50\%.Comment: 10 pages, 9 figures; comments welcom

    Supramolecular assemblies involving metal organic ring interactions: Heterometallic Cu(II)-Ln(III) two dimensional coordination polymers

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    Three isostructural two-dimensional coordination polymers of the general formula [Ln2(CuL)3(H2O)9]$5.5H2O, where Ln is La (1), Nd (2), and Gd (3), have been synthesized and isolated from aqueous solutions and their single-crystal structures determined by X-ray diffraction. The supramolecular interaction between the non-aromatic metallorings plays an important role in stabilizing the structure of these compounds. The thermal stability, reversible solvent uptake, electronic properties and magnetic studies of these compounds are also reported

    Cytotoxic and HIV-1 enzyme inhibitory activities of Red Sea marine organisms

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    BACKGROUND: Cancer and HIV/AIDS are two of the greatest public health and humanitarian challenges facing the world today. Infection with HIV not only weakens the immune system leading to AIDS and increasing the risk of opportunistic infections, but also increases the risk of several types of cancer. The enormous biodiversity of marine habitats is mirrored by the molecular diversity of secondary metabolites found in marine animals, plants and microbes which is why this work was designed to assess the anti-HIV and cytotoxic activities of some marine organisms of the Red Sea. METHODS: The lipophilic fractions of methanolic extracts of thirteen marine organisms collected from the Red Sea (Egypt) were screened for cytotoxicity against two human cancer cell lines; leukaemia (U937) and cervical cancer (HeLa) cells. African green monkey kidney cells (Vero) were used as normal non-malignant control cells. The extracts were also tested for their inhibitory activity against HIV-1 enzymes, reverse transcriptase (RT) and protease (PR). RESULTS: Cytotoxicity results showed strong activity of the Cnidarian Litophyton arboreum against U-937 (IC50; 6.5 μg/ml ±2.3) with a selectivity index (SI) of 6.45, while the Cnidarian Sarcophyton trochliophorum showed strong activity against HeLa cells (IC50; 5.2 μg/ml ±1.2) with an SI of 2.09. Other species showed moderate to weak cytotoxicity against both cell lines. Two extracts showed potent inhibitory activity against HIV-1 protease; these were the Cnidarian jelly fish Cassiopia andromeda (IC50; 0.84 μg/ml ±0.05) and the red algae Galaxura filamentosa (2.6 μg/ml ±1.29). It is interesting to note that the most active extracts against HIV-1 PR, C. andromeda and G. filamentosa showed no cytotoxicity in the three cell lines at the highest concentration tested (100 μg/ml). CONCLUSION: The strong cytotoxicity of the soft corals L. arboreum and S. trochliophorum as well as the anti-PR activity of the jelly fish C. andromeda and the red algae G. filamentosa suggests the medicinal potential of crude extracts of these marine organisms.The Medical Research Council, the Technology Innovation Agency and the University of Pretoria, South Africa.http://www.biomedcentral.com/bmccomplementalternmedam201

    Robust estimation of bacterial cell count from optical density

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    Optical density (OD) is widely used to estimate the density of cells in liquid culture, but cannot be compared between instruments without a standardized calibration protocol and is challenging to relate to actual cell count. We address this with an interlaboratory study comparing three simple, low-cost, and highly accessible OD calibration protocols across 244 laboratories, applied to eight strains of constitutive GFP-expressing E. coli. Based on our results, we recommend calibrating OD to estimated cell count using serial dilution of silica microspheres, which produces highly precise calibration (95.5% of residuals &lt;1.2-fold), is easily assessed for quality control, also assesses instrument effective linear range, and can be combined with fluorescence calibration to obtain units of Molecules of Equivalent Fluorescein (MEFL) per cell, allowing direct comparison and data fusion with flow cytometry measurements: in our study, fluorescence per cell measurements showed only a 1.07-fold mean difference between plate reader and flow cytometry data

    Global variations in diabetes mellitus based on fasting glucose and haemogloblin A1c

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    Fasting plasma glucose (FPG) and haemoglobin A1c (HbA1c) are both used to diagnose diabetes, but may identify different people as having diabetes. We used data from 117 population-based studies and quantified, in different world regions, the prevalence of diagnosed diabetes, and whether those who were previously undiagnosed and detected as having diabetes in survey screening had elevated FPG, HbA1c, or both. We developed prediction equations for estimating the probability that a person without previously diagnosed diabetes, and at a specific level of FPG, had elevated HbA1c, and vice versa. The age-standardised proportion of diabetes that was previously undiagnosed, and detected in survey screening, ranged from 30% in the high-income western region to 66% in south Asia. Among those with screen-detected diabetes with either test, the agestandardised proportion who had elevated levels of both FPG and HbA1c was 29-39% across regions; the remainder had discordant elevation of FPG or HbA1c. In most low- and middle-income regions, isolated elevated HbA1c more common than isolated elevated FPG. In these regions, the use of FPG alone may delay diabetes diagnosis and underestimate diabetes prevalence. Our prediction equations help allocate finite resources for measuring HbA1c to reduce the global gap in diabetes diagnosis and surveillance.peer-reviewe

    Retrospective evaluation of whole exome and genome mutation calls in 746 cancer samples

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    Funder: NCI U24CA211006Abstract: The Cancer Genome Atlas (TCGA) and International Cancer Genome Consortium (ICGC) curated consensus somatic mutation calls using whole exome sequencing (WES) and whole genome sequencing (WGS), respectively. Here, as part of the ICGC/TCGA Pan-Cancer Analysis of Whole Genomes (PCAWG) Consortium, which aggregated whole genome sequencing data from 2,658 cancers across 38 tumour types, we compare WES and WGS side-by-side from 746 TCGA samples, finding that ~80% of mutations overlap in covered exonic regions. We estimate that low variant allele fraction (VAF < 15%) and clonal heterogeneity contribute up to 68% of private WGS mutations and 71% of private WES mutations. We observe that ~30% of private WGS mutations trace to mutations identified by a single variant caller in WES consensus efforts. WGS captures both ~50% more variation in exonic regions and un-observed mutations in loci with variable GC-content. Together, our analysis highlights technological divergences between two reproducible somatic variant detection efforts

    Therapeutic Effects of Ten Commonly Used Chinese Herbs and Their Bioactive Compounds on Cancers

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    Effective cancer therapy is one of the biggest global challenges. Conventional cancer therapies have been at the forefront of combating cancers, but more evidence showed considerable side effects, limiting their use. There are various new therapies in development, but combined approaches for treating cancer are much expected. Natural herbs had been traditionally in use for cancer therapy in most parts of the world. In this review, we have examined ten commonly used Chinese herbs that have, for centuries, shown effectiveness in treating cancers. They demonstrated the abilities to promote the apoptosis of cancer cells, inhibit their metastasis, activate the patient’s anticancer immunity, and synergistically increase the efficacy of conventional chemotherapy and radiation therapy when used in combination. Clinical experiences had proved that these herbs and their bioactive compounds were effective against a plethora of cancers through a variety of mechanisms, effectively improving patients’ quality of life without significant side effects. These advantages indicate that there are huge potentials in the development of Chinese herbs into cancer medicine as part of a promising, holistic cancer treatment modality

    Significance of LL-37 on Immunomodulation and Disease Outcome

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    LL-37, also called cathelicidin, is an important part of the human immune system, which can resist various pathogens. A plethora of experiments have demonstrated that it has the multifunctional effects of immune regulation, in addition to antimicrobial activity. Recently, there have been increasing interest in its immune function. It was found that LL-37 can have two distinct functions in different tissues and different microenvironments. Thus, it is necessary to investigate LL-37 immune functions from the two sides of the same coin. On the one side, LL-37 promotes inflammation and immune response and exerts its anti-infective and antitumor effects; on the other side, it has the ability to inhibit inflammation and promote carcinogenesis. This review presents a brief summary of its expression, structure, and immunomodulatory effects as well as brief discussions on the role of this small peptide as a key factor in the development and treatment of various inflammation-related diseases and cancers

    Kerugian Ekonomi Akibat Penyakit Rabies di Provinsi Bali (ECONOMIC LOSSES OF RABIES IN BALI)

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    The purposeof this studywas toanalyze theeconomic losses due torabies outbreak on human anddogin the province ofBali in2008-2011. The data usedin this research wereobtainedfrom the DepartmentofHealth, Department of Animal Husbandryand Animal Healthin district level, and theprovince ofBali,Disease of Investigation Centre of Denpasar, mass media(BaliPost), as well asinterviews withtheallegedvictims of dogbiterabies. The data wereanalyzed usingeconomic models.The results showedthatthetotaleconomic loss(TK) due toan outbreakof rabiesinBali in2008-2011amounted toRp336,509,892,200.Economic lossesdue torabiesin Bali provincewere mainly frompublic health costs(KM) and the costofvaccinationandelimination(BVE) dogs. Public health costs(KM) spent the greatest loss of moneyin 2010.However, costof dogvaccination andcullingwere spent at highestin 2011. Total of economic losses(the highestlosses)(TK) of the diseasein the province ofBalioccurredin 2011, whilethe lowestin 2008.Publicawarenessfortied and cage pet is urgently needed toreduce thenumber of rabiescases. Decreasenumber of dog bites may result in reducing the related economic losses
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