36 research outputs found
The total neutron production from the alpha induced reaction on natural Zirconium
A significant amount of alpha particles, upto 35 MeV are produced in
the reactor environment. Alpha induced reaction on natural Zirconium, a reactor
component, upto 40 MeV has been measured using stacked foil activation
technique. The total neutron production cross section from all possible
channels for energies upto 35 MeV is also estimated using TALYS 1.96.
The isomeric cross section ratio for the production of the radionuclide
has been measured and reported for the first time
Alcohol Regulates Genes that Are Associated with Response to Endocrine Therapy and Attenuates the Actions of Tamoxifen in Breast Cancer Cells
Hereditary, hormonal, and behavioral factors contribute to the development of breast cancer. Alcohol consumption is a modifiable behavior that is linked to increased breast cancer risks and is associated with the development of hormone-dependent breast cancers as well as disease progression and recurrence following endocrine treatment. In this study we examined the molecular mechanisms of action of alcohol by applying molecular, genetic, and genomic approaches in characterizing its effects on estrogen receptor (ER)-positive breast cancer cells. Treatments with alcohol promoted cell proliferation, increased growth factor signaling, and up-regulated the transcription of the ER target gene GREB1 but not the canonical target TFF1/pS2. Microarray analysis following alcohol treatment identified a large number of alcohol-responsive genes, including those which function in apoptotic and cell proliferation pathways. Furthermore, expression profiles of the responsive gene sets in tumors were strongly associated with clinical outcomes in patients who received endocrine therapy. Correspondingly, alcohol treatment attenuated the anti-proliferative effects of the endocrine therapeutic drug tamoxifen in ER-positive breast cancer cells. To determine the contribution and functions of responsive genes, their differential expression in tumors were assessed between outcome groups. The proto-oncogene BRAF was identified as a novel alcohol- and estrogen-induced gene that showed higher expression in patients with poor outcomes. Knock-down of BRAF, moreover, prevented the proliferation of breast cancer cells. These findings not only highlight the mechanistic basis of the effects of alcohol on breast cancer cells and increased risks for disease incidents and recurrence, but may facilitate the discovery and characterization of novel oncogenic pathways and markers in breast cancer research and therapeutics
Probing pre-supernova mass loss in double-peaked Type Ibc supernovae from the Zwicky Transient Facility
Eruptive mass loss of massive stars prior to supernova (SN) explosion is key
to understanding their evolution and end fate. An observational signature of
pre-SN mass loss is the detection of an early, short-lived peak prior to the
radioactive-powered peak in the lightcurve of the SN. This is usually
attributed to the SN shock passing through an extended envelope or
circumstellar medium (CSM). Such an early peak is common for double-peaked Type
IIb SNe with an extended Hydrogen envelope but is uncommon for normal Type Ibc
SNe with very compact progenitors. In this paper, we systematically study a
sample of 14 double-peaked Type Ibc SNe out of 475 Type Ibc SNe detected by the
Zwicky Transient Facility. The rate of these events is ~ 3-9 % of Type Ibc SNe.
A strong correlation is seen between the peak brightness of the first and the
second peak. We perform a holistic analysis of this sample's photometric and
spectroscopic properties. We find that six SNe have ejecta mass less than 1.5
Msun. Based on the nebular spectra and lightcurve properties, we estimate that
the progenitor masses for these are less than ~ 12 Msun. The rest have an
ejecta mass > 2.4 Msun and a higher progenitor mass. This sample suggests that
the SNe with low progenitor masses undergo late-time binary mass transfer.
Meanwhile, the SNe with higher progenitor masses are consistent with
wave-driven mass loss or pulsation-pair instability-driven mass loss
simulations.Comment: Submitted to ApJ. Comments are welcome. arXiv admin note: text
overlap with arXiv:2210.0572
MicroRNA let-7c Is Downregulated in Prostate Cancer and Suppresses Prostate Cancer Growth
Prostate cancer (PCa) is characterized by deregulated expression of several tumor suppressor or oncogenic miRNAs. The objective of this study was the identification and characterization of miR-let-7c as a potential tumor suppressor in PCa.Levels of expression of miR-let-7c were examined in human PCa cell lines and tissues using qRT-PCR and in situ hybridization. Let-7c was overexpressed or suppressed to assess the effects on the growth of human PCa cell lines. Lentiviral-mediated re-expression of let-7c was utilized to assess the effects on human PCa xenografts.We identified miR-let-7c as a potential tumor suppressor in PCa. Expression of let-7c is downregulated in castration-resistant prostate cancer (CRPC) cells. Overexpression of let-7c decreased while downregulation of let-7c increased cell proliferation, clonogenicity and anchorage-independent growth of PCa cells in vitro. Suppression of let-7c expression enhanced the ability of androgen-sensitive PCa cells to grow in androgen-deprived conditions in vitro. Reconstitution of Let-7c by lentiviral-mediated intratumoral delivery significantly reduced tumor burden in xenografts of human PCa cells. Furthermore, let-7c expression is downregulated in clinical PCa specimens compared to their matched benign tissues, while the expression of Lin28, a master regulator of let-7 miRNA processing, is upregulated in clinical PCa specimens.These results demonstrate that microRNA let-7c is downregulated in PCa and functions as a tumor suppressor, and is a potential therapeutic target for PCa
Effects of hospital facilities on patient outcomes after cancer surgery: an international, prospective, observational study
Background Early death after cancer surgery is higher in low-income and middle-income countries (LMICs) compared with in high-income countries, yet the impact of facility characteristics on early postoperative outcomes is unknown. The aim of this study was to examine the association between hospital infrastructure, resource availability, and processes on early outcomes after cancer surgery worldwide.Methods A multimethods analysis was performed as part of the GlobalSurg 3 study-a multicentre, international, prospective cohort study of patients who had surgery for breast, colorectal, or gastric cancer. The primary outcomes were 30-day mortality and 30-day major complication rates. Potentially beneficial hospital facilities were identified by variable selection to select those associated with 30-day mortality. Adjusted outcomes were determined using generalised estimating equations to account for patient characteristics and country-income group, with population stratification by hospital.Findings Between April 1, 2018, and April 23, 2019, facility-level data were collected for 9685 patients across 238 hospitals in 66 countries (91 hospitals in 20 high-income countries; 57 hospitals in 19 upper-middle-income countries; and 90 hospitals in 27 low-income to lower-middle-income countries). The availability of five hospital facilities was inversely associated with mortality: ultrasound, CT scanner, critical care unit, opioid analgesia, and oncologist. After adjustment for case-mix and country income group, hospitals with three or fewer of these facilities (62 hospitals, 1294 patients) had higher mortality compared with those with four or five (adjusted odds ratio [OR] 3.85 [95% CI 2.58-5.75]; p<0.0001), with excess mortality predominantly explained by a limited capacity to rescue following the development of major complications (63.0% vs 82.7%; OR 0.35 [0.23-0.53]; p<0.0001). Across LMICs, improvements in hospital facilities would prevent one to three deaths for every 100 patients undergoing surgery for cancer.Interpretation Hospitals with higher levels of infrastructure and resources have better outcomes after cancer surgery, independent of country income. Without urgent strengthening of hospital infrastructure and resources, the reductions in cancer-associated mortality associated with improved access will not be realised
Robust estimation of bacterial cell count from optical density
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 <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
Not Available
Not AvailableThe study focuses on the estimate of the impact of Covid-19
on inland fisheries resources such as reservoirs and lake.
As per the current investigation small, medium and large
reservoir fisheries has suffered an economic loss of Rs. 36 million,
4.2 million and 0.31 million respectively. Similarly, backwater fishery
of Kerala was also affected with a loss of Rs. 35 million species wise
catch composition study in Backwaters indicated huge demand for
Lacustrine fishes during lockdown period due to restrictions imposed
on the fisheries sector of the state. The government initiatives along
with PM Kisan Samman Nidhi Yojana have helped in the revival of
the inland fisheries sector post lockdown period.Not Availabl