Pseudo-Dirac Neutrino Scenario: Cosmic Neutrinos at Neutrino Telescopes

Within the "pseudo-Dirac" scenario for massive neutrinos the existence of sterile neutrinos which are almost degenerate in mass with the active ones is hypothesized. The presence of these sterile neutrinos can affect the flavor composition of cosmic neutrinos arriving at Earth after traveling large distances from astrophysical objects. We examine the prospects of neutrino telescopes such as IceCube to probe the very tiny mass squared differences 10^(-12) eV^2<\Delta m^2<10^(-19) eV^2, by analyzing the ratio of $\mu$-track events to shower-like events. Considering various sources of uncertainties which enter this analysis, we examine the capability of neutrino telescopes to verify the validity of the pseudo-Dirac neutrino scenario and especially to discriminate it from the conventional scenario with no sterile neutrino. We also discuss the robustness of our results with respect to the uncertainties in the initial flavor ratio of neutrinos at the source.Comment: 24 pages, 5 figure

Effect of acute caffeine administration on PTZ-induced seizure threshold in mice: Involvement of adenosine receptors and NO-cGMP signaling pathway

Abstract Purpose: Caffeine is a non-selective antagonist of A1 and A2A adenosine receptors (ARs). In this regard, nitric oxide (NO) is partly involved in the central effects of caffeine. In this study, we examined the effect of acute caffeine administration on pentylenetetrazole (PTZ)-induced seizure threshold by focusing on A1Rs, A2ARs, and NO-cGMP signaling pathway. Methods: NMRI male mice (25–30 g) received caffeine (5, 50, and 100 mg/kg) alone, whereas 8-CPT (1 and 5 mg/kg, a selective A1Rs antagonist), SCH-442416 (5 and 10 mg/kg, a selective A2ARs antagonist) or sildenafil (5 and 10 mg/kg, a phosphodiesterase 5 inhibitor) were administrated alone or as pre-treatment before caffeine. Seizure threshold was assessed by intravenous infusion of PTZ. Nitric oxide metabolites (NOx) were measured with the Griess method. Results: When administrated alone, caffeine (5 and 50 mg/kg) and 8-CPT (1 and 5 mg/kg) significantly decreased seizure threshold, while 100 mg/kg of caffeine, SCH-442416 or sildenafil did not change it. Only pre-treatment with SCH-442416 (5 and 10 mg/kg) or sildenafil (5 and 10 mg/kg) before 100 mg/kg of caffeine significantly decreased seizure threshold. Moreover, NOx levels significantly decreased following alone administration of caffeine (100 mg/kg) or 8-CPT (5 mg/kg). Conclusion: The results of present study showed that 5 and 50 mg/kg of caffeine had a proconvulsant effect but caffeine at a dose of 100 mg/kg had no effect on seizure threshold. In addition, it seems that the effect caffeine on seizure threshold is partly mediated through ARs or modulation of the NO-cGMP signaling pathway. Keywords: Seizure Caffeine Nitric oxide Adenosine receptors Pentylenetetrazol

The impact of illicit drug use on Spontaneous Hepatitis C Clearance: Experience from a large cohort population study

Background and Aims: Acute hepatitis C infection usually ends in chronic infection, while in a minority of patients it is spontaneously cleared. The current population-based study is performed on a large cohort in Golestan province of Iran to examine the demographic correlates of Spontaneous Hepatitis C Clearance. Methods: Serum samples used in this study had been stored in biorepository of Golestan Cohort Study. These samples were evaluated for anti hepatitis C Virus by third generation Enzyme-linked immunosorbent assay (ELISA). Subjects who tested positive were then invited and tested by Recombinant Immunoblot Assay (RIBA) and Ribonucleic Acid Polymerase Chain Reaction test (PCR). If tested positive for RIBA, subjects were recalled and the two tests were re-done after 6 months. Those subjects who again tested positive for RIBA but negative for PCR were marked as cases of spontaneous clearance. Results: 49,338 serum samples were evaluated. The prevalence of Chronic Hepatitis C Virus (CHCV) infection based on PCR results was 0.31. Among those who had acquired hepatitis C, the rate of SC was 38. In multivariate analysis, illicit drug use both Injecting Use (OR = 3.271, 95 CI: 1.784-6.000, p-value<0.001) and Non-Injecting Use (OR = 1.901, 95 CI: 1.068-3.386, p-value = 0.029) were significant correlates of CHCV infection versus SC. Conclusions: Illicit drug use whether intravenous or non-intravenous is the only significant correlate of CHCV, for which several underlying mechanisms can be postulated including repeated contacts with hepatitis C antigen. © 2011 Poustchi et al

The effects of breathing techniques on pain intensity of burn dressing- A clinical randomized trial

Background and aim: Burn injury is a major problem that which often leads to hospitalization, surgeries, and treatment costly. Burn Pain was one of the strongest and most usually types of pain. Commonly time of dressing change is the time that burned patients are experience pain most. The present study investigated the effects of breathing techniques on pain intensity of dressing in patients during burns. Methods: This study is a randomized clinical trial, which examined the pain in 68 patients referred to the burn unit of Kashani hospital in the period of March 2012 to August 2013 through random sampling in one of Intervention or control groups were examined. The patients in the intervention group (n=34) and control group (n=34) regarding age, burn factor, and the burn percentage were identical. Results: Before the intervention, the mean dressing pain intensity score in intervention group was 6.32 ± 2.02 and in control group was 5.90 ± 1.98. After the intervention, there were significant difference between the pain intensity after dressing in intervention and control groups (p=0.04). Conclusion: According to our findings, it can be concluded that using breathing techniques can be effective in reducing pain intensity during burn dressing

Toxicity and LC50 determination of phenol and 1-Naphtol in Caspian Kutum and bream fingerlings

In this investigation acute toxicity of phenol and 1-naphthol were determined based on OECD guideline in the laboratory. Experimental fishes were Caspian kutum (Rutilus frisii kutum) and bream (Abramis brama orientalis). Static bioassays were used for acute toxicity tests during the period of 96 hours and all of important physicochemical parameters of water including pH, dissolved oxygen, hardness, temperature and conductivity were monitored continuously and maintained at a constant value. Five treatments were used and three replicates run for each treatment. The 96h LCSO values of phenol and 1-naphthol for Caspian kutum and bream were 21.5928 and 2.1544 mg/lit and 25.1880 and 2.8490 mg/lit, respectively. The Maximum Allowable Concentration (MAC) of phenol in Caspian kutum and bream were 2.1593 and 2.5188 mg/lit, respectively. The MAC value of 1-naphthol in Caspian kutum and bream were 0.2154 and 0.2849 mg/lit, respectively. It is evident from the results of the present study that Caspian kutum is more sensitive comparing to bream and the toxicity of I-naphthol is higher than phenol

The effects of breathing techniques on pain intensity of burn dressing

زمینه و هدف: درد سوختگی یکی از شدیدترین و مداوم ترین انواع درد می باشد و یکی از زمان هایی که معمولاً بیماران سوخته بیشترین میزان درد را تجربه می کنند، زمان تعویض پانسمان است. مطالعه حاضر با هدف تعیین تاثیر تکنیک های تنفسی بر شدت درد پانسمان در بیماران مبتلا به سوختگی صورت گرفت. روش بررسی: در این مطالعه کارآزمایی بالینی تعداد 68 بیمار مرد مراجعه کننده به بخش سوختگی مرکز آموزشی درمانی آیت اله کاشانی شهرکرد از طریق نمونه گیری آسان هدفمند انتخاب و سپس بطور تصادفی در یکی از گروه های مداخله یا کنترل توزیع شدند. گروه مداخله تحت مداخله تکنیک های تنفسی طی انجام پانسمان قرار گرفتند و برای گروه کنترل مراقبت روتین به اجرا در آمد. شدت درد پانسمان سوختگی در دو گروه با استفاده از ابزار سنجش درد دیداری (Visual analogue scale) ارزیابی و مقایسه گردید. یافته ها: میانگین نمره شدت درد در بدو پانسمان سوختگی در گروه مداخله 2/02±6/32 و در گروه کنترل 1/98±5/90 بود که پس از مداخله نمره شدت درد در گروه مداخله به 1/46±3/66 و در گروه کنترل به 1/38±4/80 کاهش یافت که این کاهش معنادار بود (0/04=P). نتیجه گیری: بکارگیری تکنیک های تنفس می تواند در کاهش قابل توجه شدت درد پانسمان سوختگی مؤثر باشد؛ لذا به پرستاران بخش های سوختگی و اورژانس پیشنهاد می گردد جهت تخفیف درد ناشی از پانسمان سوختگی، علاوه بر استفاده از داروهای ضد درد، بیماران را تشویق به انجام تمرینات تنفسی مکرر طی انجام پانسمان بنمایند