84 research outputs found

    Mining the gap: evolution of the magnitude gap in X-ray galaxy groups from the 3 square degree XMM coverage of CFHTLS

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    We present a catalog of 129 X-ray galaxy groups, covering a redshift range 0.04<z<1.23, selected in the ~3 square degree part of the CFHTLS W1 field overlapping XMM observations performed under the XMM-LSS project. We carry out a statistical study of the redshift evolution out to redshift one of the magnitude gap between the first and the second brightest cluster galaxies of a well defined mass-selected group sample. We find that the slope of the relation between the fraction of groups and the magnitude gap steepens with redshift, indicating a larger fraction of fossil groups at lower redshifts. We find that 22.2±\pm6% of our groups at z\leq0.6 are fossil groups. We compare our results with the predictions of three semi-analytic models based on the Millennium simulation. The intercept of the relation between the magnitude of the brightest galaxy and the value of magnitude gap becomes brighter with increasing redshift. This trend is steeper than the model predictions which we attribute to the younger stellar age of the observed brightest cluster galaxies. This trend argues in favor of stronger evolution of the feedback from active galactic nuclei at z<1 compared to the models. The slope of the relation between the magnitude of the brightest cluster galaxy and the value of the gap does not evolve with redshift and is well reproduced by the models, indicating that the tidal galaxy stripping, put forward as an explanation of the occurrence of the magnitude gap, is both a dominant mechanism and is sufficiently well modeled

    X-Ray Groups of Galaxies in the Aegis Deep and Wide Fields

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    We present the results of a search for extended X-ray sources and their corresponding galaxy groups from 800-ks Chandra coverage of the All-wavelength Extended Groth Strip International Survey (AEGIS). This yields one of the largest X-ray selected galaxy group catalogs from a blind survey to date. The red-sequence technique and spectroscopic redshifts allow us to identify 100% of reliable sources, leading to a catalog of 52 galaxy groups. The groups span the redshift range z0.0661.544z\sim0.066-1.544 and virial mass range M2001.34×10131.33×1014MM_{200}\sim1.34\times 10^{13}-1.33\times 10^{14}M_\odot. For the 49 extended sources which lie within DEEP2 and DEEP3 Galaxy Redshift Survey coverage, we identify spectroscopic counterparts and determine velocity dispersions. We select member galaxies by applying different cuts along the line of sight or in projected spatial coordinates. A constant cut along the line of sight can cause a large scatter in scaling relations in low-mass or high-mass systems depending on the size of cut. A velocity dispersion based virial radius can more overestimate velocity dispersion in comparison to X-ray based virial radius for low mass systems. There is no significant difference between these two radial cuts for more massive systems. Independent of radial cut, overestimation of velocity dispersion can be created in case of existence of significant substructure and also compactness in X-ray emission which mostly occur in low mass systems. We also present a comparison between X-ray galaxy groups and optical galaxy groups detected using the Voronoi-Delaunay method (VDM) for DEEP2 data in this field.Comment: Accepted for publication in AP

    Denosumab in patients with giant cell tumor and its recurrence: A systematic review

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    Recent studies suggest that Denosumab reduces tumor size, therefore, makes the surgery easier with lower morbidity. However, some studies have reported several complications for this drug. So, this systematic review was performed to determine the effectiveness and safety of Denosumab in reducing bone destructions activity of giant cell tumor and skeletal-related events (SRE) in affected patients with giant cell tumor of bone (GCTB) and its recurrence. We explored studies in PubMed, and Cochrane Library. For this purpose, articles of various levels were retrieved until October 22, 2016. Two reviewers assessed the articles independently based on predefined criteria to extract the relevant data. Primary outcomes associated with skeletal-related event, overall survival, and secondary outcomes such as pain, quality of life and adverse events were evaluated and analyzed. The total population of this meta-analysis consisted of 686 patients. Of this population, 55 had primary GCTB and 45 had giant cell tumor recurrence, with 2 experiencing secondary recurrence. The results showed the effectiveness of Denosumab in reducing the tumor size due to inhibiting the Osteoclastogenesis. Denosumab didnot show any effect on reducing tumor recurrence, but, in cases where complete tumor surgery is not possible and tumor residuals may remain, Denosumab can be helpful. Also, the clinicians should consider the risk benefit of Denosumab. © 2018 By The Archives of Bone and Joint Surgery

    Assessment of construction workers' hydration status using urine specific gravity

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    Objectives: The study objective was to assess hydration status by measuring USG among construction workers in Iran. Materials and Methods: The study design was comparative and experimental. Sixty participants were randomly selected from the construction workers from a construction campus with a similar type of work, climate and diet and formed 2 groups (individuals exposed to the sun and non-exposed individuals). TWL and USG were measured in both groups on 2 consequent days, at the beginning, mid and end of the work shift. Results: USG test showed that mean USG was 1.0213±0.0054 in the control group and in the exposed group, where it was significantly higher, it amounted to 1.026±0.005. In the exposed group, 38 of workers had a USG level between 1.026-1.030, representing a higher risk of heat illness and impaired performance and 12.72 had a USG level above 1.030 representing a clinically dehydrated status, while this proportion in the control group was 15.2 and 0.58, respectively. The mean TWL index measure was 215.8±5.2 W/m2 for the control group and 144±9.8 W/m2 for the exposed group, where, again, it was significantly higher. The Pearson correlation measure showed a significant correlation between USG and TWL. Conclusions: Strong correlation between TWL, as an indicator of thermal stress and USG shows that USG can be considered as a predictor of thermal stress. The difference between USG among the exposed and non-exposed workers and the increase in USG during midday work show the sensitivity of this measure in different thermal and climatic conditions, whereas, the high level of dehydration among workers despite acceptable TWL level, shows that heat stress management without considering the real hydration status of workers, is insufficient. © 2013 Versita Warsaw and Springer-Verlag Wien

    CFHTLenS: weak lensing calibrated scaling relations for low-mass clusters of galaxies

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    We present weak lensing and X-ray analysis of 12 low-mass clusters from the Canada-France-Hawaii Telescope Lensing Survey and XMM-CFHTLS surveys. We combine these systems with high-mass systems from Canadian Cluster Comparison Project and low-mass systems from Cosmic Evolution Survey to obtain a sample of 70 systems, spanning over two orders of magnitude in mass. We measure core-excised LX-TX, M-LX and M-TX scaling relations and include corrections for observational biases. By providing fully bias-corrected relations, we give the current limitations for LX and TX as cluster mass proxies. We demonstrate that TX benefits from a significantly lower intrinsic scatter at fixed mass than LX. By studying the residuals of the bias-corrected relations, we show for the first time using weak lensing masses that galaxy groups seem more luminous and warmer for their mass than clusters. This implies a steepening of the M-LX and M-TX relations at low masses. We verify the inferred steepening using a different high-mass sample from the literature and show that variance between samples is the dominant effect leading to discrepant scaling relations. We divide our sample into subsamples of merging and relaxed systems, and find that mergers may have enhanced scatter in lensing measurements, most likely due to stronger triaxiality and more substructure. For the LX-TX relation, which is unaffected by lensing measurements, we find the opposite trend in scatter. We also explore the effects of X-ray cross-calibration and find that Chandra calibration leads to flatter LX-TX and M-TX relations than XMM-Newto

    CFHTLenS: Weak lensing calibrated scaling relations for low mass clusters of galaxies

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    We present weak lensing and X-ray analysis of 12 low mass clusters from the CFHTLenS and XMM-CFHTLS surveys. We combine these systems with high-mass systems from CCCP and low-mass systems from COSMOS to obtain a sample of 70 systems, spanning over two orders of magnitude in mass. We measure core-excised Lx-Tx, M-Lx and M-Tx scaling relations and include corrections for observational biases. By providing fully bias corrected relations, we give the current limitations for Lx and Tx as cluster mass proxies. We demonstrate that Tx benefits from a significantly lower intrinsic scatter at fixed mass than Lx. By studying the residuals of the bias corrected relations, we show for the first time using weak lensing masses that galaxy groups seem more luminous and warmer for their mass than clusters. This implies a steepening of the M-Lx and M-Tx relations at low masses. We verify the inferred steepening using a different high mass sample from the literature and show that variance between samples is the dominant effect leading to discrepant scaling relations. We divide our sample into subsamples of merging and relaxed systems, and find that mergers may have enhanced scatter in lensing measurements, most likely due to stronger triaxiality and more substructure. For the Lx-Tx relation, which is unaffected by lensing measurements, we find the opposite trend in scatter. We also explore the effects of X-ray cross-calibration and find that Chandra calibration leads to flatter Lx-Tx and M-Tx relations than XMM-Newton.Comment: Analysis modified to include bias correction. Updated CCCP measurements. Comments are welcome, submitted to MNRAS, 26 pages, 20 figure

    A single-center non-blinded randomized clinical trial to assess the safety and effectiveness of PhR160 spray in the treatment of COVID-19 pneumonia

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    7-16COVID-19 is an emerging pandemic that caused a very widespread infection with more than 1000000 cases in Iran within a year. The main cause of mortality among patients with COVID-19 is pulmonary failure. In Iranian Traditional Medicine, essences have been used for curing pulmonary diseases. Pinen-Hydronoplacton-Ribonucleic acid (PHR) is an inhaler spray made of seven different plants, which all are used by humans and have desirable pharmacological features for treating pulmonary symptoms of COVID-19 patients. This study was conducted to assess the safety and effectiveness of PHR160 spray in improving pulmonary symptoms of COVID-19 patients. This was a single-centre, non-blinded randomized clinical trial with two parallel groups in two different wards of Baqiyatallah hospital, Tehran, Iran. Participants were 63 male patients diagnosed with COVID-19 pneumonia, divided into 2 groups of 32 in the intervention group and 31 in the control group. The intervention group received 5 days of PHR160 spray, 10 puffs each day, 300 micrograms in each puff in addition to the routine treatment. Oxygen saturation was measured by a pulse oximeter, every six hours and recorded daily. This study showed that administration of PhR 160 in patients of COVID-19 was safe, and it significantly increased the arterial oxygen saturation percentage in COVID-19 patients. In addition, it decreased hospitalization duration, dyspnea score, and cough score significantly in the patients. The statistical modelling test, with adjusting the age and respiratory rate for baseline and 4 days of the intervention, shows that the oxygen saturation percentage mean was significantly more in the intervention group by 5.14 units (p<0.001)

    Stellar mass-halo mass relation for the brightest central galaxies of X-ray clusters since z similar to 0.65

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    We present the brightest cluster galaxies (BCGs) catalog for SPectroscoic IDentification of eROSITA Sources (SPIDERS) DR14 cluster program value-added catalog. We list the 416 BCGs identified as part of this process, along with their stellar mass, star formation rates (SFRs), and morphological properties. We identified the BCGs based on the available spectroscopic data from SPIDERS and photometric data from SDSS. We computed stellar masses and SFRs of the BCGs on the basis of SDSS, WISE, and GALEX photometry using spectral energy distribution fitting. Morphological properties for all BCGs were derived by Sersic profile fitting using the software package SIGMA in different optical bands (g,r,i). We combined this catalog with the BCGs of galaxy groups and clusters extracted from the deeper AEGIS, CDFS, COSMOS, XMM-CFHTLS, and XMM-XXL surveys to study the stellar mass-halo mass relation using the largest sample of X-ray groups and clusters known to date. This result suggests that the mass growth of the central galaxy is controlled by the hierarchical mass growth of the host halo. We find a strong correlation between the stellar mass of BCGs and the mass of their host halos. This relation shows no evolution since z similar to 0.65. We measure a mean scatter of 0.21 and 0.25 for the stellar mass of BCGs in a given halo mass at low (0.1 <z <0.3) and high (0.3 <z <0.65) redshifts, respectively. We further demonstrate that the BCG mass is covariant with the richness of the host halos in the very X-ray luminous systems. We also find evidence that part of the scatter between X-ray luminosity and richness can be reduced by considering stellar mass as an additional variable.Peer reviewe

    Comparison of the global prevalence and trend of human intestinal carriage of ESBL-producing Escherichia coli between healthcare and community settings: a systematic review and meta-analysis

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    Objectives:The widespread intestinal carriage of ESBL-producing Escherichia coli (ESBL E. coli) among both patients and healthy individuals is alarming. However, the global prevalence and trend of this MDR bacterium in healthcare settings remains undetermined. To address this knowledge gap, we performed a comparative meta-analysis of the prevalence in community and healthcare settings.Methods:Our systematic review included 133 articles published between 1 January 2000 and 22 April 2021 and indexed in PubMed, EMBASE or Google Scholar. A random-effects meta-analysis was performed to obtain the global pooled prevalence (community and healthcare settings). Subgroup meta-analyses were performed by grouping studies using the WHO regions and 5 year intervals of the study period.Results:We found that 21.1% (95% CI, 19.1%-23.2%) of inpatients in healthcare settings and 17.6% (95% CI, 15.3%-19.8%) of healthy individuals worldwide carried ESBL E. coli in their intestine. The global carriage rate in healthcare settings increased 3-fold from 7% (95% CI, 3.7%-10.3%) in 2001-05 to 25.7% (95% CI, 19.5%-32.0%) in 2016-20, whereas in community settings it increased 10-fold from 2.6% (95% CI, 1.2%-4.0%) to 26.4% (95% CI, 17.0%-35.9%) over the same period.Conclusions:The global and regional human intestinal ESBL E. coli carriage is increasing in both community and healthcare settings. Carriage rates were generally higher in healthcare than in community settings. Key relevant health organizations should perform surveillance and implement preventive measures to address the spread of ESBL E. coli in both settings
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