424 research outputs found
Non-extensive study of Rigid and Non-rigid Rotators
The isotropic rigid and non-rigid rotators in the framework of Tsallis
statistics are studied in the high and low temperature limits. The generalized
partition functions, internal energies and heat capacities are calculated. It
has been found that results are in well agreement with the classical
Boltzmann-Gibbs statistics in the limiting Tsallis index. It has also been
observed that nonextensivity parameter q behaves like a scale parameter in the
low temperature regime.Comment: 11 Pages, 3 Figures, Late
Prenatal Diagnosis of WAGR Syndrome.
Wilm's tumour, aniridia, genitourinary abnormalities, and mental retardation (WAGR) syndrome is a rare genetic disorder with an estimated prevalence of 1 in 500,000 to 1 million. It is a contiguous gene syndrome due to deletion at chromosome 11p13 in a region containing WT1 and PAX6 genes. Children with WAGR syndrome mostly present in the newborn/infancy period with sporadic aniridia. The genotypic defects in WAGR syndrome have been well established. However, antenatal ultrasonographic presentation of this syndrome has never been reported. Prenatal diagnosis of this condition is possible in some cases with careful ultrasound examination of classical and nonclassical manifestations of this syndrome. The key point for this rare diagnosis was the decision to perform chromosomal microarray analysis after antenatal diagnosis of absent corpus callosum and absent cavum septum pellucidum, as this finding mandates search for potentially associated genetic disorders. We report a case of WAGR syndrome diagnosed prenatally at 29-week gestation. The diagnosis of the anomaly was based on two- and three-dimensional ultrasound as well as fetal MRI scan and microarray analysis. The ultrasonographic findings included borderline ventriculomegaly, absent corpus callosum, and absent cavum septum pellucidum. Cytogenetic results from the amniotic fluid confirmed WAGR syndrome. Parental karyotype was normal, with no evidence of copy number change, deletion, or rearrangement of this region of chromosome 11
Exact solution of Schrodinger equation for modified Kratzer's molecular potential with the position-dependent mass
Exact solutions of Schrodinger equation are obtained for the modified Kratzer
and the corrected Morse potentials with the position-dependent effective mass.
The bound state energy eigenvalues and the corresponding eigenfunctions are
calculated for any angular momentum for target potentials. Various forms of
point canonical transformations are applied. PACS numbers: 03.65.-w; 03.65.Ge;
12.39.Fd Keywords: Morse potential, Kratzer potential, Position-dependent mass,
Point canonical transformation, Effective mass Schr\"{o}dinger equation.Comment: 9 page
Probing Protein Folding with Substitution-Inert Metal Ions. Folding Kinetics of Cobalt(III)-Cytochrome c
Ligand-substitution processes at the heme strongly influence peptide backbone dynamics during the folding of cytochrome c (cyt c). When cyt c is unfolded with guanidine hydrochloride (GuHCl) at pH 7, one of the axial ligands (Met 80) is replaced by a nitrogenous base from an amino acid residue; this misligation introduces an energy barrier with an associated folding time of several hundred milliseconds. A great deal of evidence points to His 26 or His 33 as the ligand in unfolded horse heart cyt c. Nevertheless, recent studies indicate that other bases (Lys or N-terminus in yeast cyt c) can act as ligands as well. We have found that the substitution-inert heme in the Co(III) derivative of cyt c (Co-cyt c) allows a closer look at the folding kinetics and the ligands in the unfolded form of this protein
Structural Evidence for Asymmetrical Nucleotide Interactions in Nitrogenase
The roles of ATP hydrolysis in electron-transfer (ET) reactions of the nitrogenase catalytic cycle remain obscure. Here, we present a new structure of a nitrogenase complex crystallized with MgADP and MgAMPPCP, an ATP analogue. In this structure the two nucleotides are bound asymmetrically by the Fe-protein subunits connected to the two different MoFe-protein subunits. This binding mode suggests that ATP hydrolysis and phosphate release may proceed by a stepwise mechanism. Through the associated Fe-protein conformational changes, a stepwise mechanism is anticipated to prolong the lifetime of the Fe-protein-MoFe-protein complex and, in turn, could orchestrate the sequence of intracomplex ET required for substrate reduction
Service Systems with Heterogeneous Customers: Investigating the Effect of Telemedicine on Chronic Care
Medical specialists treating chronic conditions typically face a heterogeneous set of patients. Such heterogeneity arises because of differences in medical conditions as well as the travel burden each patient faces to visit the clinic periodically. Given this heterogeneity, we compare the strategic behavior of revenue-maximizing and welfare-maximizing specialists and prove that the former will serve a smaller patient population, spend more time with the patients, and have shorter waiting times. We also analyze the impact of telemedicine technology on patient utility and the specialists' operating decisions. We consider both the case when specialists can freely set their own fee for service and the case when fees are set exogenously by a third-party payer. We prove that with the introduction of telemedicine the specialists become more productive and the overall social welfare increases, though some patients, unexpectedly, will be worse off. Our analytical results lead to some important policy implications for facilitating the further deployment of telemedicine in the care of chronically ill patients
Analytical Solutions of Klein-Gordon Equation with Position-Dependent Mass for q-Parameter Poschl-Teller potential
The energy eigenvalues and the corresponding eigenfunctions of the
one-dimensional Klein-Gordon equation with q-parameter Poschl-Teller potential
are analytically obtained within the position-dependent mass formalism. The
parametric generalization of the Nikiforov-Uvarov method is used in the
calculations by choosing a mass distribution.Comment: 10 page
Nitrogenase Complexes: Multiple Docking Sites for a Nucleotide Switch Protein
Adenosine triphosphate (ATP) hydrolysis in the nitrogenase complex controls the cycle of association and dissociation between the electron donor adenosine triphosphatase (ATPase) (Fe-protein) and its target catalytic protein (MoFe-protein), driving the reduction of dinitrogen into ammonia. Crystal structures in different nucleotide states have been determined that identify conformational changes in the nitrogenase complex during ATP turnover. These structures reveal distinct and mutually exclusive interaction sites on the MoFe-protein surface that are selectively populated, depending on the Fe-protein nucleotide state. A consequence of these different docking geometries is that the distance between redox cofactors, a critical determinant of the intermolecular electron transfer rate, is coupled to the nucleotide state. More generally, stabilization of distinct docking geometries by different nucleotide states, as seen for nitrogenase, could enable nucleotide hydrolysis to drive the relative motion of protein partners in molecular motors and other systems
BIOLOGIC DRUG PREFERENCES OF TURKISH RHEUMATOLOGISTS IN SPONDILOARTROPATHY PATIENTS WITH ADVANCED CHRONIC RENAL DISEASE
[Abstract Not Available
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