6,219 research outputs found
Study through Geant4, for Time Resolution characterization of different detectors arrays coupled with two SiPMs, as a function of: the scintillator plastic material, its volumetric dimensions and the location of the radiation emission source
The high time resolution detectors are relevant in those experiments or simulations were the particles to detect, have a very short time of flight (TOF), and due this it´s required that the detections times are ranged between ns. & ps.Using Geant4 software, it was made thirty simulations of coupled detectors to plastic scintillators with two silicon photomultipliers (SiPMs) located on the scintillator’s central sides. To characterize the time resolution, it was required to quantify the optical photons that reach the Score in a certain time, which are generated by muons on the surface of the plastic scintillator. Different configurations of muon beams were simulated at energy of 1 GeV, to interact with the configuration of the scintillator material of its corresponding arrangement. The simulations were made varying three parameters: the scintillator material “BC404 & BC422”, its size, and the location of the radiation source. Fifteen simulations correspond to BC404 material & fifteen simulations to BC422 material respectively. The first five simulations consisted in varying the scintillator’s volumetric size and collocate the muons beam guided randomly distributed over it, the next five simulations differentiate from setting up a directly centered beam, and the last five simulations for guide the beam on the left lower corner of each scintillator.The best time resolution achieved was σ= 8.67 +/− 0.26 ps., reported by the detector with BC422 scintillator material which has a volume of 20x20x3 mm3
Co-prescription patterns of cardiovascular preventive treatments: A cross-sectional study in the Aragon worker' health study (Spain)
Objectives: To identify cardiovascular disease (CVD) preventive treatments combinations, among them and with other drugs, and to determine their prevalence in a cohort of Spanish workers.
Design: Cross-sectional study. Setting Aragon Workers'' Health Study (AWHS) cohort in Spain. Participants 5577 workers belonging to AWHS cohort. From these subjects, we selected those that had, at least, three prescriptions of the same therapeutic subgroup in 2014 (n=4605). Primary and secondary outcome measures Drug consumption was obtained from the Aragon Pharmaceutical Consumption Registry (Farmasalud). In order to know treatment utilisation, prevalence analyses were conducted. Frequent item set mining techniques were applied to identify drugs co-prescription patterns. All the results were stratified by sex and age.
Results: 42.3% of men and 18.8% of women in the cohort received, at least, three prescriptions of a CVD preventive treatment in 2014. The most prescribed CVD treatment were antihypertensives (men: 28.2%, women 9.2%). The most frequent association observed among CVD preventive treatment was agents acting on the renin-angiotensin system and lipid-lowering drugs (5.1% of treated subjects). Co-prescription increased with age, especially after 50 years old, both in frequency and number of associations, and was higher in men. Regarding the association between CVD preventive treatments and other drugs, the most frequent pattern observed was lipid-lowering drugs and drugs used for acid related disorders (4.2% of treated subjects).
Conclusions: There is an important number of co-prescription patterns that involve CVD preventive treatments. These patterns increase with age and are more frequent in men. Mining techniques are a useful tool to identify pharmacological patterns that are not evident in the individual clinical practice, in order to improve drug prescription appropriateness
A template method to measure the tt polarisation
This work is supported by the Spanish Research Agency (Agencia Estatal de Investigacion) through the grant IFT Centro de Excelencia Severo Ochoa SEV-2016-0597, by the projects PID2019-110058GB-C21, PID2019-110058GB-C22 from MICINN/AEI/ERDF, and by projects CERN/FIS-PAR/0004/2019, CERN/FIS-PAR/0029/2019 from FCT. The work of P.M.R. is supported through the FPI grant BES-2016-076775. The work of M.C.N.F. was supported by the PSC-CUNY Awards 63096-00 51 and 64031-00 52.We develop a template method for the measurement of the polarisation of tt¯ pairs produced in hadron collisions. The method would allow to extract the individual fractions of tLt¯ L, tRt¯ R, tLt¯ R and tRt¯ L pairs with a fit to data, where L, R refer to the polarisation along any axis. These polarisation fractions have not been independently measured at present. Secondarily, the method also provides the net polarisation of t and t¯ , as well as their spin correlation for arbitrary axes.IFT Centro de Excelencia Severo Ochoa
PID2019-110058GB-C21, PID2019-110058GB-C22, SEV-2016-0597PSC-CUNY
63096-00 51, 64031-00 52Spanish Research AgencyFamily Process Institute
BES-2016-076775Ministerio de Ciencia e InnovaciónEuropean Regional Development Fund
CERN/FIS-PAR/0004/2019, CERN/FIS-PAR/0029/2019Fundació Catalana de TrasplantamentAgencia Estatal de Investigació
Prevalence of Intestinal Parasites in Endangered Ashy Red Colobus Monkeys (Piliocolobus tephrosceles) in Tanzania
Intestinal parasites constitute one of the most frequent causes of gastrointestinal diseases in primates, directly affecting their health. We sampled 3 populations of the Endangered ashy red colobus monkey (Piliocolobus tephrosceles) with different levels of anthropogenic disturbance in Tanzania. We collected faecal samples (n=157) soon after defecation and fixed them in situ in 70% ethanol. We then re-fixed half of each sample in MIF (merthiolate iodine formaline) for microscopic study and saved the rest for molecular analysis. We examined helminth eggs, larvae and protozoan cysts using a light microscope after faecal sedimentation. We analysed samples positive for Giardia using Polymerase Chain Reaction (PCR) to determine genotypes. The overall prevalence of protozoan and helminth infection was 94.3% (148/157), with 64.9% (96/148) being infected by 1 species, 25.7% (38) by 2 species, and 9.5% (14) by 3 or more species. We detected 8 species of intestinal parasites: Ancylostoma sp. (13.4%), Trichuris trichiura (3.8%), Strongyloides stercoralis rhabditoid larvae (2.5%), Entamoeba chatonni (82.8%), Iodamoeba butschlii (14%), Endolimax nana (4.5%), Blastocystis hominis (2.5%) and Giardia duodenalis (14%). These species were detected in different combinations in the 3 areas, while Giardia was detected in only 1 area. The molecular analysis of positive Giardia samples showed that all of them belonged to assemblage B, which could also infect humans. However, we could not identify an exclusively anthropogenic origin of the parasitic species found. Our study contributes to our knowledge of parasitic infections in ashy monkeys in Tanzania, allowing us to assess their health status and disease risk, which in turn will help us design more successful conservation strategies for this Endangered primate in Tanzani
In Vivo Confirmation of the Role of Statins in Reducing Nitric Oxide and C-Reactive Protein Levels in Peripheral Arterial Disease
AbstractObjectivesInflammatory and other processes mediating impairment of endothelial function, where there are increased levels of C-reactive protein (CRP) and plasma nitrites, have a part to play in the early stages of peripheral arterial disease (PAD). Our objective was to analyse the effect of statins on the plasma nitrite and CRP levels in PAD.Material and methodsA prospective study of 30 patients with PAD Fontaine stage II, with no prior treatment with statins, determined high sensitivity (hs)-CRP and lipid profile in the patients. Plasma nitrite levels were determined by colourimetric assay based on the Griess reaction, at baseline and after 1 month of treatment with atorvastatin 40mgday−1.ResultsA significant reduction in plasma nitrite levels was detected after the treatment with statins (11.88±7.8μM vs. 5.7±1.8μM, p=0.0001). There was also a significant reduction in hs-CRP levels (13.58±24.00 vs. 3.93±3.19, p=0.02).When the patients were stratified according to claudication stage, a significant reduction in nitrite levels was obtained, both in patients with PAD Fontaine stage IIA (9.5±3.3μM vs. 5.3±1.7μM, p=0.0001) and in stage IIB (16.6±11.6μM vs. 6.7±1.8μM, p=0.032).ConclusionsTreatment with statins lowers plasma nitrite and CRP levels in patients with PAD. Our data support the effects of statins in vivo that have been demonstrated on the endothelium ex vivo, suggesting a beneficial effect by acting on the initial processes that trigger the disease, reducing oxidative stress (increase in the bioavailability of nitric oxide as peroxynitrite levels decrease) and curtailing the inflammatory processes which perpetuate the disease
Quantitative proteomics and bioinformatic analysis provide new insight into the dynamic response of porcine intestine to Salmonella Typhimurium
The enteropathogen Salmonella Typhimurium (S. Typhimurium) is the most commonly non-typhoideal serotype isolated in pig worldwide. Currently, one of the main sources of human infection is by consumption of pork meat. Therefore, prevention and control of salmonellosis in pigs is crucial for minimizing risks to public health. The aim of the present study was to use isobaric tags for relative and absolute quantification (iTRAQ) to explore differences in the response to Salmonella in two segment of the porcine gut (ileum and colon) along a time course of 1, 2, and 6 days post infection (dpi) with S. Typhimurium. A total of 298 proteins were identified in the infected ileum samples of which, 112 displayed significant expression differences due to Salmonella infection. In colon, 184 proteins were detected in the infected samples of which 46 resulted differentially expressed with respect to the controls. The higher number of changes in protein expression was quantified in ileum at 2 dpi. Further biological interpretation of proteomics data using bioinformatics tools demonstrated that the expression changes in colon were found in proteins involved in cell death and survival, tissue morphology or molecular transport at the early stages and tissue regeneration at 6 dpi. In ileum, however, changes in protein expression were mainly related to immunological and infection diseases, inflammatory response or connective tissue disorders at 1 and 2 dpi. iTRAQ has proved to be a proteomic robust approach allowing us to identify ileum as the earliest response focus upon S. Typhimurium in the porcine gut. In addition, new functions involved in the response to bacteria such as eIF2 signaling, free radical scavengers or antimicrobial peptides (AMP) expression have been identified. Finally, the impairment at of the enterohepatic circulation of bile acids and lipid metabolism by means the under regulation of FABP6 protein and FXR/RXR and LXR/RXR signaling pathway in ileum has been established for the first time in pigs. Taken together, our results provide a better understanding of the porcine response to Salmonella infection and the molecular mechanisms underlying Salmonella-host interactions.This research was supported by the National R&D Program of the Spanish Ministry of Science and Innovation (AGL2011-28904 and AGL2014-54089-R).Peer reviewedPeer Reviewe
Preclinical assessment of the receptor-binding domain of Plasmodium vivax duffy-binding protein as a vaccine candidate in rhesus macaques
The receptor-binding domain of Plasmodium vivax Duffy-binding protein, region II (PvRII), is an attractive candidate for a vaccine against P. vivax malaria. Here, we have studied the safety and immunogenicity of recombinant PvRII in Macaca mulatta (rhesus monkeys). Recombinant PvRII with a C-terminal 6-histidine tag was expressed in E. coli, recovered from inclusion bodies, refolded into its functional conformation, purified to homogeneity and formulated with three adjuvants, namely, Alhydrogel, Montanide ISA 720 and the GSK proprietary Adjuvant System AS02A for use in immunogenicity studies. All the PvRII vaccine formulations tested were safe and highly immunogenic. The overall magnitude of the antibody response was significantly higher for both Montanide ISA 720 and AS02A formulations in comparison with Alhydrogel. Furthermore, there was a significant correlation between antibody recognition titers by ELISA and binding inhibition titers in in vitro binding assays. The PvRII vaccine formulations also induced IFN-γ recall responses that were identified using ex vivo ELISPOT assays. These results provide support for further clinical development of a vaccine for P. vivax malaria based on recombinant PvRII
The mitochondrial activity of leukocytes from Artibeus jamaicensis bats remains unaltered after several weeks of flying restriction
Bats are the only flying mammals known. They have longer lifespan than other mammals of similar size and weight and can resist high loads of many pathogens, mostly viruses, with no signs of disease. These distinctive characteristics have been attributed to their metabolic rate that is thought to be the result of their flying lifestyle. Compared with non-flying mammals, bats have lower production of reactive oxygen species (ROS), and high levels of antioxidant enzymes such as superoxide dismutase. This anti-oxidative vs. oxidative profile may help to explain bat's longer than expected lifespans. The aim of this study was to assess the effect that a significant reduction in flying has on bats leukocytes mitochondrial activity. This was assessed using samples of lymphoid and myeloid cells from peripheral blood from Artibeus jamaicensis bats shortly after capture and up to six weeks after flying deprivation. Mitochondrial membrane potential (Δψm), mitochondrial calcium (mCa2+), and mitochondrial ROS (mROS) were used as key indicators of mitochondrial activity, while total ROS and glucose uptake were used as additional indicators of cell metabolism. Results showed that total ROS and glucose uptake were statistically significantly lower at six weeks of flying deprivation (p 0.05). These results suggest that bat mitochondria are stable to sudden changes in physical activity, at least up to six weeks of flying deprivation. However, decrease in total ROS and glucose uptake in myeloid cells after six weeks of captivity suggest a compensatory mechanism due to the lack of the highly metabolic demands associated with flying
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