No abstract

We report synthesis and magnetic properties of quasi-one-dimensional spin-12 Heisenberg antiferromagnetic chain compound BaNa2Cu(VO4)2. This orthovanadate has a centrosymmetric crystal structure, C2/c, where the magnetic Cu2+ ions form spin chains. These chains are arranged in layers, with the chain direction changing by 62∘ between the two successive layers. Alternatively, the spin lattice can be viewed as anisotropic triangular layers upon taking the interchain interactions into consideration. Despite this potential structural complexity, temperature-dependent magnetic susceptibility, heat capacity, electron spin resonance intensity, and nuclear magnetic resonance (NMR) shift agree well with the uniform spin-1/2 Heisenberg chain model with an intrachain coupling of J/kB≃5.6 K. The saturation field obtained from the magnetic isotherm measurement consistently reproduces the value of J/kB. Further, the 51V NMR spin-lattice relaxation rate mimics the one-dimensional character in the intermediate temperature range, whereas magnetic long-range order sets in below TN≃0.25 K. The effective interchain coupling is estimated to be J⊥/kB≃0.1 K. The theoretical estimation of exchange couplings using bandstructure calculations reciprocate our experimental findings and unambiguously establish the onedimensional character of the compound. Finally, the spin lattice of BaNa2Cu(VO4)2 is compared with the chemically similar but not isostructural compound BaAg2Cu(VO4)2.

Introduction Gallstone diseases constitute a major part of patients visiting hospitals, and more than 50% of operation theaters are occupied by it or diseases related to it. It also imposes significant financial burden on health resources. The 21st century has opened with an improved foundation to our understanding of the basis of bile formation by defining the key transporters of the lipids in bile and the responsible genes. The specter of obesity as an epidemic in developed countries, and the recent recognition of the metabolic syndromes and their links to gallstone formation, emphasize the expectation of a rise in the frequency of cholesterol cholelithiasis. Materials and Methods Data pertaining to patients who were admitted/received surgery for a diagnosis of gallstone diseases at the Department of General Surgery of BPS GMC Khanpur Kalan was collected.The collected data was entered in a Microsoft Excel spreadsheet. Mean ± standard deviation (SD) was calculated for quantitative data, using Student’s “t” test/Kruskal test. Chi-square test was used to find out the association for categorical data. Results and Discussion Most of the patients were experiencing right hypochondriac pain (79.23%) as presenting complaints, with the most common age range being 31 to 40 years, followed by 41 to 50 years, that is, 31.85% and 20.74%, respectively. Females were most commonly affected, approximately 90%, and only 10% of patients with gallstones visiting our hospital were males. Maximum patients had chronic cholecystitis (80%) on histopathological examination, followed by cholesterosis (6.15%). As much as 82.6% of patients presented with mixed gallstones, followed by cholesterol stones, that is, 10.43%. All types of stones are more common in patients with abdominal adiposities, that is, having waist-to-hip ratio more than 0.85, and these findings are statistically significant. Conclusion Our study concluded that gallstones were more common in females of younger population (31–40 years) with right hypochondriac pain as presenting complaints. The most common histopathology was chronic cholecystitis with mixed types of stones, which is associated with increased waist-to-hip ratio. All biochemical markers were within normal range.