800 research outputs found

    Factorized ground state for a general class of ferrimagnets

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    We have found the exact (factorized) ground state of a general class of ferrimagnets in the presence of a magnetic field which covers the frustrated, anisotropic and long range interactions for arbitrary dimensional space. In particular cases, our model represents the bond-alternating, ferromagnet-antiferromagnet and also homogeneous spin ss model. The factorized ground state is a product of single particle kets on a bipartite lattice composed of two different spins (ρ,σ\rho, \sigma). The spin waves analysis around the exact ground state show two branch of excitations which is the origin of two dynamics of the model. The signature of these dynamics is addressed as a peak and a broaden bump in the specific heat.Comment: 4 pages and 2 figures, some typos correcte

    Optical quenching and recovery of photoconductivity in single-crystal diamond

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    We study the photocurrent induced by pulsed-light illumination (pulse duration is several nanoseconds) of single-crystal diamond containing nitrogen impurities. Application of additional continuous-wave light of the same wavelength quenches pulsed photocurrent. Characterization of the optically quenched photocurrent and its recovery is important for the development of diamond based electronics and sensing

    Preliminary report of hepatitis B virus genotype prevalence in Iran

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    Aim: To determine the prevalence of hepatitis B virus (HBV) genotypes in Iranian hepatitis B surface antigen (HBsAg) carriers, chronic hepatitis B and cirrhotic patients. Methods: A total of 109 HBsAg-positive patients were included in this study. HBV genotypes were determined by using INNO-LiPA methodology which is based on the reverse hybridization principle. Results: The distribution of patients with different stages of liver disease was as follows: 95 (86.4) chronic hepatitis, 11 (10) liver cirrhosis, and 3 (2.7) inactive carrier. Of the chronic hepatitis and liver cirrhosis patients, 26.4 were HBeAg-positive while 70 were HBeAg-negative. Genotype D was the only detected type found in all patients. Conclusion: Classifying HBV into genotypes has to be cost-effective and clinically relevant. Our study indicates that HBV genotype D prevails in the Mediterranean area, Near and Middle East, and South Asia. Continued efforts for understanding HBV genotype through international co-operation will reveal further virological diffierences of the genotypes and their clinical relevance. © 2006 The WJG Press. All rights reserved

    Key traveller groups of relevance to spatial malaria transmission: a survey of movement patterns in four sub-Saharan African countries

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    Background: As malaria prevalence declines in many parts of the world due to widescale control efforts and as drug-resistant parasites begin to emerge, a quantitative understanding of human movement is becoming increasingly relevant to malaria control. However, despite its importance, significant knowledge gaps remain regarding human movement, particularly in sub-Saharan Africa. Methods: A quantitative survey of human movement patterns was conducted in four countries in sub-Saharan Africa: Mali, Burkina Faso, Zambia, and Tanzania, with three to five survey locations chosen in each country. Questions were included on demographic and trip details, malaria risk behaviour, children accompanying travellers, and mobile phone usage to enable phone signal data to be better correlated with movement. A total of 4352 individuals were interviewed and 6411 trips recorded. Results: A cluster analysis of trips highlighted two distinct traveller groups of relevance to malaria transmission: women travelling with children (in all four countries) and youth workers (in Mali). Women travelling with children were more likely to travel to areas of relatively high malaria prevalence in Mali (OR = 4.46, 95 % CI = 3.42–5.83), Burkina Faso (OR = 1.58, 95 % CI = 1.23–1.58), Zambia (OR = 1.50, 95 % CI = 1.20–1.89), and Tanzania (OR = 2.28, 95 % CI = 1.71–3.05) compared to other travellers. They were also more likely to own bed nets in Burkina Faso (OR = 1.77, 95 % CI = 1.25–2.53) and Zambia (OR = 1.74, 95 % CI = 1.34 2.27), and less likely to own a mobile phone in Mali (OR = 0.50, 95 % CI = 0.39–0.65), Burkina Faso (OR = 0.39, 95 % CI = 0.30–0.52), and Zambia (OR = 0.60, 95 % CI = 0.47–0.76). Malian youth workers were more likely to travel to areas of relatively high malaria prevalence (OR = 23, 95 % CI = 17–31) and for longer durations (mean of 70 days cf 21 days, p < 0.001) compared to other travellers. Conclusions: Women travelling with children were a remarkably consistent traveller group across all four countries surveyed. They are expected to contribute greatly towards spatial malaria transmission because the children they travel with tend to have high parasite prevalence. Youth workers were a significant traveller group in Mali and are expected to contribute greatly to spatial malaria transmission because their movements correlate with seasonal rains and hence peak mosquito densities. Interventions aimed at interrupting spatial transmission of parasites should consider these traveller groups

    Favorable results after conservative management of 316 valproate intoxicated patients

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    Valproic acid (VPA) is an effective antiepileptic drug widely used worldwide. Despite several studies indicating the usefulness of intravenous L-carnitine in the treatment of VPA poisoning, this drug is not readily available in Iran. The aim of this study was to determine whether supportive care without antidote would result in acceptable outcomes in VPA poisoned patients. Materials and Methods: In an observational, retrospective, single-center case series, all patients &gt;12-year-old with VPA overdose who had referred to a tertiary center between 2009 and 2013 were consecutively enrolled. Patients� demographic and presenting features, physical examinations, clinical management, laboratory data, and outcomes were recorded. Results: A total of 316 patients were enrolled with pure VPA toxicity. The most common presenting signs/symptoms were drowsiness, nausea and vomiting, vertigo, and headache. In the course of the disease, 14 patients (4.4) were intubated and three (0.9) required hemodialysis with mean dialysis sessions of two. Fourteen patients were admitted to Intensive Care Unit, and seizures occurred in five. The initial level of consciousness was lower in patients with poor outcome. The median ingested dose of VPA in patients who required dialysis was significantly higher (20 vs. 6 g; P = 0.006). Multivariate analyses revealed that coma on presentation was associated with a worse outcome (P = 0.001; odds ratio = 61.5, 95 CI = 5.8-646.7). Conclusion: Prognosis of VPA poisoned patients appears to be good even with supportive care. According to our study, older age, ingestion of higher amounts of VPA and lower PCO2, HCO3, base excess, and CPK levels prone the patients to more severe toxicities in univariate analysis, but the main poor prognostic factor is coma on presentation in multivariate analysis. © 2015 Journal of Research in Medical Sciences

    The promising applications of ultrasound in emergency medicine and critical care related to in cancer: A review

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    The referral of critically ill cancer patients to an Intensive Care Unit (ICU) is a matter of controversial debate. During the past decade, ultrasound imaging performed by emergency physicians and critical care providers has gained significant clinical importance. A number of researches reported the ability of emergency physicians and critical care providers to carry out and interpret bedside assessments exactly, along with a great effect on the quality of care. It is possible assessing ultrasound-mediated subjects who are very much instable to be evaluated through alternative imaging methods. Furthermore, ultrasound in the emergency medicine and critical care open a new way towards facilitate diagnosis, simplify rapid dispositions, and influence management decisions. The primarily perspective of bedside ultrasound by emergency physicians and critical care providers was limited to a few applications. However, it was observed a number of new applications due to the universal and extensive adaptation of ultrasound in emergency uses. In this review, we discussed the promising applications of ultrasound for emergency medicine and critical care that encompass telemedicine, prehospital setting, soft tissue, fractures, ocular, paracentesis, pneumothorax, foreign bodies, bladder and arthrocentesis ultrasound. © Oncology and Radiotherapy

    Acute pain management in emergency department, low dose ketamine versus morphine, a randomized clinical trial

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    Background: Ketamine, as an opium alternative, has been proposed for pain relief in the emergency department (ED). Objectives: This study was carried out to compare low dose ketamine (LDK) with morphine for pain relief in trauma patients. Methods: In this randomized double-blinded clinical trial, 300 trauma patients from the ED of 2 teaching hospitals in Tehran, Iran were enrolled and randomly divided into 2 equal groups. The 1st group received 0.2 mg/kg of ketamine while the 2nd group received 0.1 mg/kg of intravenous morphine. The pain intensity and complications were measured and compared every 15 minutes to 1 hour. Results: Fifteen minutes after drug injection in both groups, a significant reduction was found in average pain intensity compared to the initial pain (P = 0.01). At 15 minutes, no significant difference was found in both groups in regards to average pain intensity (P = 0.23). The average pain intensity at 30, 45, and 60 minutes in the group receiving morphine was lower than the ketamine group (P = 0.01, P &lt; 0.001, P &lt; 0.001 respectively). Two complications (drop in O2 saturation below 90 and flushing) were significantly greater in the morphine group. Conclusions: The results of this study suggest that LDK, at a dose of 0.2 mg/kg, in the earlier minutes leads to significant reduction of pain when compared to that of intravenous morphine. It also created fewer complications than morphine. © 2017, Anesthesiology and Pain Medicine

    Acute pain management in emergency department, low dose ketamine versus morphine, a randomized clinical trial

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    Background: Ketamine, as an opium alternative, has been proposed for pain relief in the emergency department (ED). Objectives: This study was carried out to compare low dose ketamine (LDK) with morphine for pain relief in trauma patients. Methods: In this randomized double-blinded clinical trial, 300 trauma patients from the ED of 2 teaching hospitals in Tehran, Iran were enrolled and randomly divided into 2 equal groups. The 1st group received 0.2 mg/kg of ketamine while the 2nd group received 0.1 mg/kg of intravenous morphine. The pain intensity and complications were measured and compared every 15 minutes to 1 hour. Results: Fifteen minutes after drug injection in both groups, a significant reduction was found in average pain intensity compared to the initial pain (P = 0.01). At 15 minutes, no significant difference was found in both groups in regards to average pain intensity (P = 0.23). The average pain intensity at 30, 45, and 60 minutes in the group receiving morphine was lower than the ketamine group (P = 0.01, P &lt; 0.001, P &lt; 0.001 respectively). Two complications (drop in O2 saturation below 90 and flushing) were significantly greater in the morphine group. Conclusions: The results of this study suggest that LDK, at a dose of 0.2 mg/kg, in the earlier minutes leads to significant reduction of pain when compared to that of intravenous morphine. It also created fewer complications than morphine. © 2017, Anesthesiology and Pain Medicine

    Electrocardiographic changes in patients with tramadol-induced idiosyncratic seizures

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    Objectives To assess ECG changes in patients with tramadol-induced seizure(s) and compare these changes in lower and higher than 500 mg tramadol doses as a main goal. Material and methods In an analytical-cross sectional manner over 1 year, 170 patients with idiosyncratic seizure(s) after using tramadol, were studied. Full data were recorded for each patient. ECGs were taken from all the patients on admission and 1 h later and were assessed for findings. Results 70 of 170 patients (41.2) had used lower than 500 mg doses of tramadol while 90 patients (52.9) were included in the high dose group. Rate of female patients in the high dose group was significantly higher. The average age of patients in the high dose group was significantly lower (22.04 vs 25.76). The high dose group had significantly higher heart rates. There was no history of cardiovascular diseases; two patients had previous history of seizure. No significant difference was shown between low dose and high dose groups from the point of ECG changes. Discussion and conclusion Using doses higher than 500 mg is more frequently seen in women, young people and those who have not experienced previous use of tramadol. Terminal S wave, sinus tachycardia, and terminal R wave in the lead aVR are among the most common ECG changes in tramadol users. © 2016 The Emergency Medicine Association of Turke
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