319 research outputs found
Phase Diagram of the Electron-Doped Cuprate Superconductors
We investigate the phase diagram of the electron-doped systems in high-Tc
cuprates. We calculate the superconducting transition temperature Tc, the
antiferromagnetic transition temperature TN, the NMR relaxation rate 1/T1 with
the antiferromagnetic fluctuations in the fluctuation-exchange (FLEX)
approximation and with the superconducting fluctuations in the self-consistent
t-matrix approximation. Obtained phase diagram has common features as those in
the hole-doped systems, including the antiferromagnetic state, the
superconducting state and the spin gap phenomenon. Doping-dependences of TN, Tc
and Tsg (spin gap temperature) are, however, different with those in the
hole-doped systems. These differences are due to the intrinsic nature of the
ingap states which are intimately related with the Zhang-Rice singlets in the
hole-doped systems and are correlated d-electrons in the electron-doped
systems, respectively, which has been shown in the d-p model.Comment: 4 pages, 3 figure
Charge ordering and antiferromagnetic exchange in layered molecular crystals of the theta type
We consider the electronic properties of layered molecular crystals of the
type theta-DA, where A is an anion and D is a donor molecule such as
BEDT-TTF [where BEDT-TTF is bis-(ethylenedithia-tetrathiafulvalene)] which is
arranged in the theta type pattern within the layers. We argue that the
simplest strongly correlated electron model that can describe the rich phase
diagram of these materials is the extended Hubbard model on the square lattice
at a quarter filling. In the limit where the Coulomb repulsion on a single site
is large, the nearest-neighbour Coulomb repulsion, V, plays a crucial role.
When V is much larger than the intermolecular hopping integral t the ground
state is an insulator with charge ordering. In this phase antiferromagnetism
arises due to a novel fourth-order superexchange process around a plaquette on
the square lattice. We argue that the charge ordered phase is destroyed below a
critical non-zero value V, of the order of t. Slave boson theory is used to
explicitly demonstrate this for the SU(N) generalisation of the model, in the
large N limit. We also discuss the relevance of the model to the all-organic
family beta''-(BEDT-TTF)SFYSO where Y = CHCF, CH, CHF.Comment: 15 pages, 6 eps figure
Podoconiosis and soil-transmitted helminths (STHs): double burden of neglected tropical diseases in Wolaita zone, rural southern Ethiopia
Background
Both podoconiosis and soil-transmitted helminth (STH) infections occur among barefoot people in areas of extreme poverty; however, their co-morbidity has not previously been investigated. We explored the overlap of STH infection and podoconiosis in Southern Ethiopia and quantified their separate and combined effects on prevalent anemia and hemoglobin levels in podoconiosis patients and health controls from the same area.
Methods and Principal Findings
A two-part comparative cross-sectional study was conducted in Wolaita zone, southern Ethiopia. Data were collected from adult patients presenting with clinically confirmed podoconiosis, and unmatched adult neighborhood controls living in the same administrative area. Information on demographic and selected lifestyle factors was collected using interviewer-administered questionnaires. Stool samples were collected and examined qualitatively using the modified formalin-ether sedimentation method. Hemoglobin level was determined using two different methods: hemoglobinometer and automated hematology analyzer. A total of 913 study subjects (677 podoconiosis patients and 236 controls) participated. The prevalence of any STH infection was 47.6% among patients and 33.1% among controls (p<0.001). The prevalence of both hookworm and Trichuris trichiura infections was significantly higher in podoconiosis patients than in controls (AOR 1.74, 95% CI 1.25 to2.42, AOR 6.53, 95% CI 2.34 to 18.22, respectively). Not wearing shoes and being a farmer remained significant independent predictors of infection with any STH. There was a significant interaction between STH infection and podoconiosis on reduction of hemoglobin level (interaction p value = 0.002).
Conclusions
Prevalence of any STH and hookworm infection was higher among podoconiosis patients than among controls. A significant reduction in hemoglobin level was observed among podoconiosis patients co-infected with hookworm and ‘non-hookworm STH’. Promotion of consistent shoe-wearing practices may have double advantages in controlling both podoconiosis and hookworm infection in the study area
NMR investigations of the interaction between the azo-dye sunset yellow and Fluorophenol
The interaction of small molecules with larger noncovalent assemblies is important across a wide range of disciplines. Here, we apply two complementary NMR spectroscopic methods to investigate the interaction of various fluorophenol isomers with sunset yellow. This latter molecule is known to form noncovalent aggregates in isotropic solution, and form liquid crystals at high concentrations. We utilize the unique fluorine-19 nucleus of the fluorophenol as a reporter of the interactions via changes in both the observed chemical shift and diffusion coefficients. The data are interpreted in terms of the indefinite self-association model and simple modifications for the incorporation of a second species into an assembly. A change in association mode is tentatively assigned whereby the fluorophenol binds end-on with the sunset yellow aggregates at low concentration and inserts into the stacks at higher concentrations
Hydatidosis: experience with hepatic and pulmonary hydatid disease
From 1989-1992, 35 cases comprising of 20 hepatic and 15 pulmonary hydatid cysts were seen. Four patients with pulmonary hydatid disease had previous or concomitant hepatic hydatidosis compared to no concomitant pulmonary hydatid disease in the hepatic group. Hepatic hydatid disease had a greater tendency to be right sides, infected and calcified. Anaphylactic reactions occurred in 3 of 20 patients with hepatic hydatid disease against none in 15 patients with pulmonary disease. Management consisted of evacuation, drainage and obliteration of the residual cavity by capittonage in the lung and omentoplasty in the liver. Two patients, one hepatic and one with pulmonary hydatid disease developed infection of the residual cavity. Bronchocystic fistula occurred in 4 pulmonary and cystobiliary fistula in 2 hepatic hydatid disease patients. One patient with severe pleuropulmonary hydatidosis required a thoracoplasty. No recurrences have been noted in either group over a mean follow-up of 11 months (range 3 weeks- 3 years)
Retained stones in the common bile duct: results of management
Seventeen patients underwent treatment for retained common bile duct stones. In 7 patients the stones were removed via a T-tube tract using steerable catheters while 5 patients underwent ERCP and sphincterotomy and 5 underwent surgical re-exploration. Considering morbidity, mortality, success rate and patients\u27 stay in the hospital, non-operative modalities should be the treatment of choice for retained common bile duct stones
Il-1� C376a transversion variant and risk of idiopathic male infertility in Iranian men: A genetic association study
Background: IL-1α produced by Sertoli cells is considered to act as a growth factor for spermatogonia. In this study,
we investigated the association of the C376A polymorphism in IL-1α with male infertility in men referring to the Kashan IVF Center.
Materials and Methods: In this case-control study, 2 ml of blood was collected from 230 fertile and 230 infertile men. After DNA extraction, the C376A variant was genotyped by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). In addition, the molecular effects of the C376A transversion were analysed using bioinformatics tools.
Results: A significant association was observed between the homozygous genotype CC with male infertility [odds ratio
(OR)=1.97, 95% confidence interval (CI)=1.14-3.41, P=0.016)]. Carriers of C (AC+CC) showed a similar risk for
male infertility (OR=1.78, 95% CI=1.06-2.99, P=0.030). Also, allelic analysis showed that the C allele is associated
with male infertility (OR=1.43, 95% CI=1.09-1.88, P=0.011). In sub-group analysis, we found that the AC genotype
is associated with asthenozoospermia (OR=2.38, 95% CI=1.03-5.53, P=0.043). In addition, carriers of C were at
high risk for asthenozoospermia (OR=2.25, 95% CI=1.01-4.10, P=0.047). Also, C allele was significantly associated
with oligozoospermia (OR=1.44, 95% CI=1.01-2.06, P=0.049) and non-obstructive azoospermia (OR=1.67, 95% CI
=1.04-2.68, P=0.034). Finally, in silico analysis showed that the C376A polymorphism could alter splicing especially
in the acceptor site.
Conclusion: This is the preliminary report on the association of IL-1α C376A polymorphism with male infertility in the
Kashan population. This association shows that the IL-1α gene may be a biomarker for male infertility, and therefore
needs additional investigations in future studies to validate this.
Keywords: Genetic Polymorphism, Interleukin-1α, Male Infertility, Spermatogenesi
Explaining varieties of corruption in the Afghan justice sector
© 2015 Taylor & Francis. Judicial reform in Afghanistan is seriously undermined by systemic corruption that has resulted in low legitimacy of the state and weak rule of law. This article reviews the main shortcomings in the Afghan justice system with reference to 70 interviews conducted in Kabul. Building on legal pluralism and a political economic approach, the shortcomings and causes and consequences of corruption in the Afghan justice sector are highlighted. These range from low pay, resulting in bribery; criminal and political intrusion into the judiciary; non-adherence to meritocracy, with poorly educated judges and prosecutors; and low funding in the judicial sector resulting in weak case tracking and human rights abuses in the countryside. This is followed by sociological approaches: understanding corruption from a non-Western approach and emphasis on religion, morality and ethics in order to curb it
Enhancement of Edge-based Image Quality Measures Using Entropy for Histogram Equalization-based Contrast Enhancement Techniques
An Edge-based image quality measure (IQM) technique for the assessment of histogram equalization (HE)-based contrast enhancement techniques has been proposed that outperforms the Absolute Mean Brightness Error (AMBE) and Entropy which are the most commonly used IQMs to evaluate Histogram Equalization based techniques, and also the two prominent fidelity-based IQMs which are Multi-Scale Structural Similarity (MSSIM) and Information Fidelity Criterion-based (IFC) measures. The statistical evaluation results show that the Edge-based IQM, which was designed for detecting noise artifacts distortion, has a Person Correlation Coefficient (PCC) > 0.86 while the others have poor or fair correlation to human opinion, considering the Human Visual Perception (HVP). Based on HVP, this paper propose an enhancement to classic Edge-based IQM by taking into account the brightness saturation distortion which is the most prominent distortion in HE-based contrast enhancement techniques. It is tested and found to have significantly well correlation (PCC > 0.87, Spearman rank order correlation coefficient (SROCC) > 0.92, Root Mean Squared Error (RMSE) < 0.1054, and Outlier Ratio (OR) = 0%)
Role of promoters in hoisting the catalytic performance for enhanced CO methanation
The increasing demand of natural gas and its rising cost have urged some countries to take initiatives to fulfil their energy needs. The production of substituted natural gas (SNG) by syngas (CO + H2) from coal or biomass is one of the most effective methods. As a promising source of energy, SNG has attracted much attention on research and applications due to the high demand for environmental protection. It is regarded as a clean energy source and an effective method for the application of coal resources, particularly in the regions with abundant coal resources but scarce natural gas such as in China [1-3]. SNG has attracted increasing attention due to its lower emission of sulphur and particulate matter. SNG is expected to be one of the main energy sources of the 21st century. It is environmentally friendly and less costly, has high calorific value, complete combustion, and smoke free compared to other energy sources. It has significant importance for the industrial level and transportation sectors
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