Device operation of organic tandem solar cells

A generalized methodology is developed to obtain the current-voltage characteristic of polymer tandem solar cells by knowing the electrical performance of both sub cells. We demonstrate that the electrical characteristics of polymer tandem solar cells are correctly predicted for both the series and parallel connection of the sub cells. The agreement with experiments allows us to investigate the effect of a reduced open-circuit voltage, short-circuit current or fill factor in one of the sub cells on the performance of the tandem cell. A low fill factor in one of the sub cells leads to a stronger reduction of the efficiency in a series configuration as compared to the parallel tandem device. (C) 2008 Elsevier B.V. All rights reserved

The Remarkable Beneficial Effect of Adding Oral Simvastatin to Topical Betamethasone for Treatment of Psoriasis: A Double-blind, Randomized, Placebo-controlled Study

Psoriasis is a common chronic inflammatory disease with unpredictableprognosis. Given the immunomodulatory effects of statins, the present study was conducted to determine whether the addition of orally administered simvastatin to the topical betamethasone, a standard antipsoriatic treatment, can produce a more powerful therapeutic response against this clinical conundrum.In a double-blind study, 30 patients with plaque type psoriasis were randomly divided into two equal treatment groups. Group 1 received oralsimvastatin (40 mg/d) plus topical steroid (50% betamethasone in petrolatum) for 8 weeks and group 2 received oral placebo plus the same topical steroid for the same time period. Psoriasis Area and Severity Index (PASI) score was checked before and at the end of the treatment period.PASI score decreased significantly in both groups, but the decline of PASI score was more significant in patients who received simvastatin(Mann-Whitney test; P-value=0.001). No side effect or any laboratory abnormality was detected in patients.Our work, which is the first doubleblind, randomized, placebo-controlled study on this subject, shows that oral simvastatin enhances the therapeutic effect of topical steroids against psoriasis. The increased risk of cardiovascular accidents in psoriatic patients and the protective effect of statins against cardiovascular disease further encourages their use in the treatment of this clinical conundrum.Keywords: Simvastatin – Psoriasis – Treatment – Topical Steroid

The mammals of Anzali Wetland in the Southern Caspian Sea

Anzali Wetland as a listed habitat in Montreux Record, was investigated for the mammal fauna during Jan. 2015 - Jan. 2016. About 165 km of water bodies and 200 km around Anzali Wetland were patrolled, respectively. By applying different methods, such as direct observation, different signs recording, using different sampling traps,nets and camera traps, twenty mammal species were identified from 5 orders and 13 families. While Wild boar,Golden Jackal and Common otter were widely distributed, Common badger, Asiatic wildcat and Jungle cat were observed in some parts of this wetland. Six rodent species were recognized in different parts of the wetland. Among four identified bat species, Nathusius’s pipistrelle has been reported only from this region in Iran. The most commonly recorded bat species was the Soprano pipistrelle, a species hereto recorded only from two Iranian localities. Two recognized species from order Eulipotyphla; Caspian shrew and a mysterious mole are important due to their narrow geographical distribution range as well as their taxonomic situation. Although there was no quantitative or qualitative data from the past, our results show that the situation of many mammal species are not suitable, and some of them are being increasingly threatened

The Role of Serotonin in Fear Learning and Memory: A Systematic Review of Human Studies

Fear is characterized by distinct behavioral and physiological responses that are essential for the survival of the human species. Fear conditioning (FC) serves as a valuable model for studying the acquisition, extinction, and expression of fear. The serotonin (5-hydroxytryptamine, 5-HT) system is known to play a significant role in emotional and motivational aspects of human behavior, including fear learning and expression. Accumulating evidence from both animal and human studies suggests that brain regions involved in FC, such as the amygdala, hippocampus, and prefrontal cortex, possess a high density of 5-HT receptors, implicating the crucial involvement of serotonin in aversive learning. Additionally, studies exploring serotonin gene polymorphisms have indicated their potential influence on FC. Therefore, the objective of this work was to review the existing evidence linking 5-HT with fear learning and memory in humans. Through a comprehensive screening of the PubMed and Web of Science databases, 29 relevant studies were included in the final review. These studies investigated the relationship between serotonin and fear learning using drug manipulations or by studying 5-HT-related gene polymorphisms. The results suggest that elevated levels of 5-HT enhance aversive learning, indicating that the modulation of serotonin 5-HT2A receptors regulates the expression of fear responses in humans. Understanding the role of this neurochemical messenger in associative aversive learning can provide insights into psychiatric disorders such as anxiety and post-traumatic stress disorder (PTSD), among others

A REVIEW ARTICLE ON HERPES SIMPLEX ENCEPHALITIS

Abstract:Herpes Simplex encephalitis (HSE) is a life threatening outcome of Herpes simplex virus (HSV) infection of the central nervous system (CNS). HSVaccounts for 2-5 percent of all cases of encephalitis. One third of cases occur in those younger than 20 years old and one half in those older than 50 years old.Clinical diagnosis is recommended in the encephalopathic, febrile patients with focal neurological signs. However, the clinical findings are not pathogonomic because numerous other diseases of CNS can mimic HSE. Diagnosis should be confirmed based on medical history, analysis of cerebrospinal fluid (CSF) for protein and glucose contents, the cellular analysis and identifying the pathogens by serology and Polymerase Chain Reaction (PCR) amplification .The diagnostic gold standard is the detection of HSV DNA in the cerebrospinal fluid by PCR. But negative results need to be interpreted regarding thepatients clinical signs and symptoms and the time of CSF sampling. Spike and slow wave patterns is observed in Electroencephalogram (EEG).Neuroimaging, especially Magnetic Resonance Imaging (MRI) is essential for evaluating the patients, which shows temporal lobe edema or hemorrhage.All patients with HSE should be treated by intravenous Acyclovir (10mg/kg q8hr for 14-21 days). After completing therapy, PCR of the CSF can confirmthe elimination of replicating virus, assisting further management of the patient.Keywords:Herpes Simplex Virus (HSV), Encephalitis, Childre

Oxygen isotope effect and phase separation in the optical conductivity of (La0.5_{0.5}Pr0.5_{0.5})0.7_{0.7}Ca0.3_{0.3}MnO3_3 thin films

The optical conductivities of films of (La$_{0.5}$Pr$_{0.5}$)$_{0.7}$Ca$_{0.3}$MnO$_3$ with different oxygen isotopes ($^{16}$O and $^{18}$O) have been determined in the spectral range from 0.3 to 4.3 eV using a combination of transmission in the mid-infrared and ellipsometry from the near-infrared to ultra-violet regions. We have found that the isotope exchange strongly affects the optical response in the ferromagnetic phase in a broad frequency range, in contrast to the almost isotope-independent optical conductivity above $T_C$. The substitution by $^{18}$O strongly suppresses the Drude response and a mid-infrared peak while enhancing the conductivity peak at 1.5 eV. A qualitative explanation can be given in terms of the phase separation present in these materials. Moreover, the optical response is similar to the one extracted from measurements in polished samples and other thin films, which signals to the importance of internal strain.Comment: 11 pages, 11 figures, to appear in PR

Haemoglobin and serum ferritin levels in newborn babies born to anaemic Iranian women: A cross-sectional study in an Iranian Hospital

The purpose of this study was to assess the haemoglobin and serum ferritin levels in newborn babies of anaemic mothers and to determine relationship between maternal iron status with neonatal biochemical and anthropometric characteristics. A total of 70 pregnant women aged between 17 and 40 years were divided into two groups based on their pre-delivery Haemoglobin (Hb) and Serum Ferritin (SF) concentrations; anaemic mothers Hb<11 g/dl and SF � 10 ng/ml; normal control group Hb � 11 g/dl and SF � 10 ng/ml. Maternal biochemical assessments were obtained before delivery and neonatal anthropometric and biochemical measurements were obtained immediately after delivery. Mean maternal haemoglobin and serum ferritin levels were 11.2±1.16 (g/dl) and 45.8±20.8 (ng/ml), respectively. Incidence of anaemia among Iranian pregnant women in this study was 51.4. Mean neonatal weight, length and head circumference born to anaemic mothers was 2.8±0.23 kg, 47.9±1.0 cm and 31.5±0.9 cm, respectively, while, among neonates born to normal mothers were 3.3±0.1 kg, 49.6±0.8 cm and 33.7±0.6 cm, respectively. No significant correlation were found between neonatal and maternal serum ferritin concentration. Significant differences were found between neonatal haemoglobin levels from normal and anaemic mothers (p<0.001). Maternal Hb level showed significant (p<0.001) positive correlation with neonatal birth weight (r = 0.729), length (r = 0.665) and head circumference (r = 0.762). However, similar positive correlations were not found between maternal serum ferritin concentration and pregnancy outcome. Neonatal haemoglobin levels were positively correlated with that of their mothers' (r = 0.423, p<0.001). In conclusion, this study showed that maternal haemoglobin concentration had strong influence on neonatal parameters. © Asian Network for Scientific Information, 2010

Relaxations of fluorouracil tautomers by decorations of fullerene-like SiCs: DFT studies

Decorations of silicon carbide (SiC) fullerene-like nanoparticles by fluorouracil (FU) and its tautomers are investigated through density functional theory (DFT) calculations. Two models of fullerene-like particles including Si12C8 and Si8C12 are constructed to be counterparts of decorated hybrid structures, FU@Si12C8 and FU@Si8C12, respectively. The initial models including original FU and tautomeric structures and SiC nanoparticles are individually optimized and then combined for further optimizations in the hybrid forms. Covalent bonds are observed for FU@Si12C8 hybrids, whereas non-covalent interactions are seen for FU@Si8C12 ones. The obtained properties indicated that Si12C8 model could be considered as a better counterpart for interactions with FU structures than Si8C12 model. The results also showed significant effects of interactions on the properties of atoms close to the interacting regions in nanoparticles. Finally, the tautomeric structures show different behaviors in interactions with SiC nanoparticles, in which the SiC nanoparticles could be employed to detect the situations of tautomeric processes for FU structures. © 2016 Elsevier B.V