114 research outputs found
SMAS: A solution-based multi-agent system for improving problem solving skills in computer programming
In this research, a solution-based multi-agent system (SMAS) is proposed, which benefits from a novel automatic text-to-flowchart conversion approach in order to improve students' problem solving skills. The aim is to introduce the early stages of learning programming (CS1). By using SMAS, students can focus on solution designing activities in the form of flowchart development more than on language and syntax. Ultimately, an experimental study is devised to assess the success of SMAS as a tool to aid students with problem solving activities and learning computer programming. In total, 30.4% of problems that were left unresolved in previous sessions were solved by students in the control group, whereas 69.7% of previously unresolved problems were solved by students in the experimental group who used SMAS. Therefore, the use of SMAS in practice is supported, as the results indicate considerable gains for the experimental group over the control group
Local and non-local equivalent potentials for p-12C scattering
A Newton-Sabatier fixed energy inversion scheme has been used to equate
inherently non-local p-C potentials at a variety of energies to pion
threshold, with exactly phase equivalent local ones. Those energy dependent
local potentials then have been recast in the form of non-local Frahn-Lemmer
interactions.Comment: 15 pages plus 9 figures submitted to Phys. Rev.
Estrogen receptor beta selectively restricts proliferation and favors surveillance in mammary epithelial cells
Estrogen (17β-estradiol) has paradoxical effects in both promoting and preventing breast cancer as estrogen activates proliferation, but also promotes p53-mediated surveillance pathways. Estrogen mediates its effects in target tissues through the activation of estrogen receptor subtypes: ERα and ERβ. To examine the capability of these receptors in mediating surveillance as opposed to proliferation, selective estrogen receptor agonists were compared with 17β-estradiol for induction of proliferation and radiation induced apoptosis in vivo. Transcriptional regulation of estrogen-responsive genes was also compared in mouse mammary epithelium in vivo and in the human mammary MCF7 cell line transduced with a repressible ERβ. Selective activation of ERβ with the agonist diarylpropionitrile (DPN) in vivo enhances p53-mediated apoptosis in the mouse mammary epithelium without stimulating proliferation. In addition, radiation-induced apoptosis is significantly reduced in mice lacking ERβ (βERKO). As expected, 17β-estradiol or selective activation of ERα with pyrazole triol (PPT) induced the expression of estrogen-response genes including progesterone receptor, amphiregulin and trefoil factor 1. DPN and ERβ failed to induce the expression of these genes. Interestingly, the ERβ agonist DPN selectively induced the expression of genes that repress proliferation including TGFβ2 while inhibiting proliferative canonical wnt signaling via beta-catenin by inducing WNT5a and AXIN2. DPN was also more potent in stimulating the expression of EGR1, a modulator of p53 activity. These results suggest that ERα and ERβ have distinct roles in gene regulation. In addition, the ability of DPN and ERβ to potentiate surveillance pathways while limiting proliferation suggests that ERβ agonists may have therapeutic and chemopreventive value in breast cancer
Curvaton and the inhomogeneous end of inflation
We study the primordial density perturbations and non-Gaussianities generated
from the combined effects of an inhomogeneous end of inflation and curvaton
decay in hybrid inflation. This dual role is played by a single isocurvature
field which is massless during inflation but acquire a mass at the end of
inflation via the waterfall phase transition. We calculate the resulting
primordial non-Gaussianity characterized by the non-linearity parameter,
, recovering the usual end-of-inflation result when the field decays
promptly and the usual curvaton result if the field decays sufficiently late.Comment: 13 pages, 5 figure
The efficacy of N-Acetylcysteine in severe COVID-19 patients: A structured summary of a study protocol for a randomised controlled trial
Objectives: Severe acute respiratory infection (SARI) caused by the SARS-CoV-2 virus may cause lung failure and the need for mechanical ventilation. Infection with SARS-COV-2 can lead to activation of inflammatory factors, increased reactive oxygen species, and cell damage. In addition to mucolytic effects, N-Acetylcysteine has antioxidant effects that we believe can help patients recover. In this study, we evaluate the efficacy of N-Acetylcysteine in patients with severe COVID-19. Trial design: This is a prospective, randomized, single-blinded, phase 3 controlled clinical trial with two arms (ratio 1:1) parallel-group design of 40 patients, using the placebo in the control group. Participants: All severe COVID-19 patients with at least one of the following five conditions: (respiration rate > 30 per minute), hypoxemia (O2 � saturation, arterial oxygen partial pressure ratio 50 of lung area during 24 48 h), Lactate dehydrogenase (LDH) > 245 U / l, Progressive lymphopenia, and admitted to the intensive care unit of Shahid Mohammadi Hospital in Bandar Abbas and have positive PCR test results for SARS-Cov-2 and sign the written consent of the study will be included. Patients will be excluded from the study if they have a history of hypersensitivity to N-Acetylcysteine, pregnancy, or refuse to participate in the study. Intervention and comparator: After randomization, participants in the intervention group receive standard of care (SOC) according to the National Committee of COVID-19 plus N-acetylcysteine (EXI-NACE 200mg/mL, in 10mL ampules of saline for parenteral injection (EXIR pharmaceutical company)) at a dose of 300 mg/kg equivalent to 20 gr as a slow single intravenous injection on the first day of hospitalization. In the control group patients receive SOC and placebo (Sterile water for injection as the same dose). The placebo is identical in appearance to the N-acetylcysteine injection (EXIR pharmaceutical company as well). Main outcomes: The primary endpoint for this study is a composite endpoint for the length of hospitalization in the intensive care unit and the patient's clinical condition. These outcomes were measured at the baseline (before the intervention) and on the 14th day after the intervention or on the discharge day. Randomisation: Eligible participants (40) will be randomized in two arms in the ratio of 1: 1 (20 per arm) using online web-based tools and by permuted block randomization method. To ensure randomization concealment, random sequence codes are assigned to patients by the treatment team at the time of admission without knowing that each code is in the intervention or comparator group. Blinding (masking): All participants will be informed about participating in the study and the possible side effects of medication and placebo. Patients participating in the study will not be aware of the assignment to the intervention or control group. The principal investigator, health care personnel, data collectors, and those evaluating the outcome are aware of patient grouping. Numbers to be randomised (sample size): A total of 40 patients participate in this study, which are randomly divided; 20 patients in the intervention group will receive SOC and N-acetylcysteine, 20 patients in the control group will receive SOC and placebo. Trial status: First version of the protocol was approved by the Deputy of Research and Technology and the ethics committee of Hormozgan University of Medical Sciences on February 14, 2021, with the local code 990573, and the recruitment started on March 2, 2021 and the expected recruitment end date is April 1, 2021. Trial registration: The protocol was registered before starting participant recruitment entitled: Evaluation of the efficacy of N-Acetylcysteine in severe COVID-19 patients: a randomized controlled phase III clinical trial, IRCT20200509047364N3, at Iranian Registry of clinical trials on 20 February 2021. Full protocol: The full protocol is attached as an additional file, accessible from the Trials website (Additional file 1). In the interest in expediting dissemination of this material, the familiar formatting has been eliminated; this Letter serves as a summary of the key elements of the full protocol. The study protocol has been reported in accordance with the Standard Protocol Items: Recommendations for Clinical Interventional Trials (SPIRIT) guidelines (Additional file 2). © 2021, The Author(s)
Evaluation of the efficacy and safety of recombinant erythropoietin on the improvement of hospitalised COVID-19 patients: A structured summary of a study protocol for a randomised controlled trial
Objectives: To evaluate the effect of recombinant erythropoietin on hospitalised COVID-19 patients. Trial design: Concealed, randomized, single-blinded, phase 2 controlled clinical trial with two arm parallel-group design of 20 patients allocated with 1:1 ratio and using the placebo in the control group. Participants: This study will be performed at Shahid Mohammadi Hospital in Bandar Abbas, Hormozgan in Iran. All positive (PCR confirmed) COVID-19 patients �65 years old who have Hb�9 and at least one of the severe COVID-19 symptoms (tachypnea (breathing rate> 30 beats per minute), hypoxemia (O2 �93 saturation, the partial pressure ratio of arterial oxygen <300), Lung infiltration (> 50 of lung field within 24 to 48 hours), progressive lymphopenia, LDH>245 U/I, CRP>100) and are willing to cooperate in this project will be included in the study. Patients with a history of coronary heart disease, thrombosis, deep vein thrombosis, chronic lung disease, diabetes mellitus, weakened immune system, end-stage renal disease, liver disease, and patients with a history of taking oral contraceptive pills, systolic blood pressure more than 160 mm Hg, diastolic blood pressure more than 90 mm Hg and age over 65 and erythropoietin above 500 are excluded. Intervention and comparator: Patients will receive the standard of care (SOC) based on the treatment protocols of the Iranian National Committee of COVID-19 and recombinant erythropoietin (EPREX Manufactured by Johnson and Johnson Pharmaceutical Company) 300 units / Kg or 4000IU as subcutaneous (SQ) injection three times a day for 5 days and simultaneously Enoxaparin 1 mg/kg SQ daily is also taken to prevent thrombosis in the intervention group. Patients' blood pressure, along with other vital signs, are checked regularly and at regular intervals. In the control group, patients received SOC and the placebo (distilled water) is given as a subcutaneous injection three times a day for 5 days. We use sterile water for injection (EXIRpharmaceutical company) as the placebo. To the same appearance of the placebo and the recombinant erythropoietin, they are taken in a separate room in the same size syringes and cover with labels before injection. Main outcomes: The main outcome for this study is a composite endpoint for Patient clinical symptoms (Respiratory rate, Oxygen saturation state and arterial oxygen partial pressure ratio, Lung infiltration status, blood pressure), Laboratory tests (LDH, CRP, Lymphocyte count, Endogenous erythropoietin, and Haemoglobin level). All of these will be assessed at the beginning of the study (before the intervention) and day 5 after the intervention. The study will also evaluate side effects and how to manage them. Randomisation: Eligible participants (20) will be randomized in two arms in the ratio of 1: 1 (10 per arm) by permuted block randomization method using online web-based tools. Blinding (masking): Patients participating in the study will not be aware of the assignment to the intervention or control group. The principal investigator, health care personnel, data collectors, and those evaluating the outcome are aware of patient grouping. Numbers to be randomised (sample size): A total of 20 patients will participate in this study, who are randomly allocated to the 2 arms with a 1:1 ratio; 10 patients in the intervention group will receive SOC and recombinant erythropoietin, and 10 patients in the control group will receive SOC and placebo. Trial Status: The protocol version is 3.0, approved by the Deputy of Research and Technology and the ethics committee of Hormozgan University of Medical Sciences on 6th June 2020, with the local grant number of 990108. The expected recruitment end date was on 21th December 2020 but since we had a wide and careful exclusion criteria because of the adverse reactions of the medication, the recruitment (for both cases and controls) was not so easy and did not finish on the expected date and we are still recruiting now. Recruitment began on 17th August 2020 and the updated expected recruitment end date is 1st August 2021. Trial registration: The protocol was registered before starting subject recruitment under the title: Evaluation of the effect of recombinant erythropoietin on the improvement of COVID-19 patients, IRCT20200509047364N1, at Iranian Registry of clinical trials (https://en.irct.ir/trial/49282) on 2020/08/09. Full protocol: The full protocol is attached as an additional file, accessible from the Trials website (Additional file 1). In the interest in expediting dissemination of this material, the familiar formatting has been eliminated; this Letter serves as a summary of the key elements of the full protocol. The study protocol has been reported in accordance with the Standard Protocol Items: Recommendations for Clinical Interventional Trials (SPIRIT) guidelines (Additional file 2). © 2021, The Author(s)
The Efficacy of Famotidine in improvement of outcomes in Hospitalized COVID-19 Patients: A structured summary of a study protocol for a randomised controlled trial
Objectives: This study aims to investigate the effect of Famotidine on the recovery process of COVID-19 patients. Trial design: This phase III randomized clinical trial was designed with two parallel arms, placebo-controlled, single-blind, and concealed allocation. Participants: All COVID-19 patients admitted to Shahid Mohammadi Hospital in Bandar Abbas whose PCR test results are positive for SARS-Cov-2 and sign the written consent of the study are included in the study and immunocompromised patients, end-stage renal disease, moderate renal failure (clearance Creatinine 30 to 50 ml/min) or stage 4 severe chronic kidney disease or need for dialysis (creatinine clearance lesser than 30 ml/min), history of liver disease, hepatitis C infection or alcoholism, Glucose 6 phosphate dehydrogenase deficiency(G6PD), the ratio of Alanine transaminase to Aspartate transaminase 5 times above the normal limit, history or evidence of long QT segment on Electrocardiogram, psoriasis or porphyria, pregnancy, use of oral contraceptives, Dasatinib, Neratinib, Ozanimod, Pazopanib, Rilpivirine, Siponimod and/or Tizanidine and allergies to any study drug are excluded. Intervention and comparator: Intervention group receives standard pharmacotherapy according to the treatment protocols of the National Committee of COVID-19 and oral famotidine 160 mg (Manufactured by Chemidarou Pharmaceutical Company) four times a day until the day of discharge, for a maximum of fourteen days. Comparator group receives standard drug therapy according to the treatment protocols of the National Committee of COVID-19 and placebo in the same dosage. Main outcomes: Patients� temperature, respiration rate, oxygen saturation, lung infiltration, lactate dehydrogenase and complete blood count were measured at the baseline (before the intervention) and on day 14 after the intervention or on the discharge day. Randomisation: The person who has no role in admitting patients and assigning patients to random codes preparing random sequences using online tools and by permuted block randomization method. Eligibility criteria are monitored by the person responsible for admitting patients. Codes in a random sequence are assigned to patients by the treatment team without knowing that each code is in the intervention or comparator group. Patient codes are then matched to randomly generated sequence information for interventions. Blinding (masking): All participants are unaware of which group of this study they are in and after grouping patients in the groups, Patients receive Famotidine in the treatment group and receive a placebo in the control group. The lead researcher, care givers, data collectors, and outcome assessors are aware of the grouping of patients. Numbers to be randomised (sample size): As there is no prior work on this research question, so no assumptions for the sample size calculation could be made. A total of 20 patients participate in this study, which are randomly divided into two groups of 10 as intervention or control groups. Trial status: Version 3 of the protocol was approved by the Deputy of Research and Technology and the ethics committee of Hormozgan University of Medical Sciences on August 2, 2020, with the local code 990245, and the recruitment started on August 17, 2020. recruitment ended on August 31, 2020. Since the recruitment ended earlier than expected (the expected recruitment end date was 21/12/2020), we submitted post recruitment but prior to publication of the results. Trial registration: The protocol was registered before starting subject recruitment under the title: The effect of Famotidine on the improvement of patients with COVID-19, IRCT20200509047364N2, at Iranian Registry of clinical trials (https://www.irct.ir/trial/49657) on 17 August 2020. Full protocol: The full protocol is attached as an additional file, accessible from the Trials website (Additional file 1). In the interest in expediting dissemination of this material, the familiar formatting has been eliminated; this Letter serves as a summary of the key elements of the full protocol. The study protocol has been reported in accordance with the Standard Protocol Items: Recommendations for Clinical Interventional Trials (SPIRIT) guidelines (Additional file 2). © 2020, The Author(s)
Intensifying the Fischer-Tropsch Synthesis by Reactor Structuring—A
Abstract This paper investigates the intensification of Fischer-Tropsch Synthesis in two types of threephase catalytic reactors: slurry bubble columns and multi-tubular fixed beds. A simple mathematical model is used to analyse the effect of structuring on the C 5+ productivity of these two types of reactors. The results of the model show that decreasing the backmixing with a factor 4 and increasing the gas residence time in a slurry bubble column considerably enhances the production of C 5+ . On the other hand in a fixed bed reactor a similar improvement is obtained when the heat transfer coefficient is improved with a factor 2.5 and the diffusion length in catalyst particles is decreased with a factor 2. Both reactors show a potential improvement in productivity per reactor volume; 20% in the slurry bubble column and 40% in the fixed bed reactor
Microscopic description of cluster radioactivity in actinide nuclei
Cluster radioactivity is the emission of a fragment heavier than an α particle and lighter than mass 50. The range of clusters observed in experiments goes from 14C to 32Si while the heavy mass residue is always a nucleus in the neighborhood of the doubly-magic 208Pb nucleus. Cluster radioactivity is described in this paper as very asymmetric nuclear fission. A new fission valley leading to a decay with large fragment mass asymmetry matching the cluster radioactivity products is found. The mass octupole moment is found to be more convenient than the standard quadrupole moment as the parameter driving the system to fission. The mean-field Hartree-Fock-Bogoliubov theory with the phenomenological Gogny interaction has been used to compute the cluster emission properties of a wide range of even-even actinide nuclei from 222Ra to 242Cm, where emission of the clusters has been experimentally observed. Computed half-lives for cluster emission are compared with experimental results. The noticeable agreement obtained between the predicted properties of cluster emission (namely, cluster masses and emission half-lives) and the measured data confirms the validity of the proposed methodology in the analysis of the phenomenon of cluster radioactivity. A continuous fission path through the scission point has been described using the neck parameter constraintThe work of LMR was supported by Ministerio de Ciencia e Innovacion (Spain) Grants No. FPA2009-08958 and No. FIS2009-07277, as well as by Consolider-Ingenio 2010 Programs CPAN CSD2007-00042 and MULTIDARK CSD2009- 00064. The work of MW was supported by Ministerstwo Nauki i Szkolnictwa Wyzszego (Poland) under Grant No. N N202 23113
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