Comment on: "Estimating the Hartree-Fock limit from finite basis set calculations" [Jensen F (2005) Theor Chem Acc 113:267]

We demonstrate that a minor modification of the extrapolation proposed by Jensen [(2005): Theor Chem Acc 113:267] yields very reliable estimates of the Hartree-Fock limit in conjunction with correlation consistent basis sets. Specifically, a two-point extrapolation of the form $E_{HF,L}=E_{HF,\infty}+A(L+1)\exp(-9\sqrt{L})$ yields HF limits $E_{HF,\infty}$ with an RMS error of 0.1 millihartree using aug-cc-pVQZ and aug-cc-pV5Z basis sets, and of 0.01 millihartree using aug-cc-pV5Z and aug-cc-pV6Z basis sets.Comment: Theoretical Chemistry Accounts, in pres

2,4-Bis(3-chloro­phen­yl)-3-aza­bicyclo­[3.3.1]nonan-9-one

In the mol­ecular structure of the title compound, C20H19Cl2NO, the bicyclic system adopts a twin-chair conformation with equatorial orientations of both substituents. The dihedral angle between the aromatic rings is 43.60 (2)° with respect to each other. The crystal structure is stabilized by weak N—H⋯O and strong C—H⋯O inter­actions

Global hybrids from the semiclassical atom theory satisfying the local density linear response

We propose global hybrid approximations of the exchange-correlation (XC) energy functional which reproduce well the modified fourth-order gradient expansion of the exchange energy in the semiclassical limit of many-electron neutral atoms and recover the full local density approximation (LDA) linear response. These XC functionals represent the hybrid versions of the APBE functional [Phys. Rev. Lett. 106, 186406, (2011)] yet employing an additional correlation functional which uses the localization concept of the correlation energy density to improve the compatibility with the Hartree-Fock exchange as well as the coupling-constant-resolved XC potential energy. Broad energetical and structural testings, including thermochemistry and geometry, transition metal complexes, non-covalent interactions, gold clusters and small gold-molecule interfaces, as well as an analysis of the hybrid parameters, show that our construction is quite robust. In particular, our testing shows that the resulting hybrid, including 20\% of Hartree-Fock exchange and named hAPBE, performs remarkably well for a broad palette of systems and properties, being generally better than popular hybrids (PBE0 and B3LYP). Semi-empirical dispersion corrections are also provided.Comment: 12 pages, 4 figure

A Comprehensive Study of Patients Admitted with Snakebite in Tirunelveli Medical College Hospital

BACKGROUND: Patients admitted with snake bite can have varied manifestations and complications which needed special care and specialized treatments. To alert the treating physician about the possible presenting symptoms and signs and the possible complications, we need some baseline information about the incidence of snake bite in that given area, commonest type of snake and percentage of patients develops complications, the mortality and outcome. This study was conducted to provide such information. AIM OF THE STUDY: To study the Incidence of snake bite, complications and predicting the outcome based on variable factors in patients > 12 years of age. METHODS: It was prospective observational study done in 403 patients admitted in the study period of 1 year (from May 2017 to April 2018). Around 20 parameters were recorded using pre-structured proforma. Data analyzed using SPSS software version 21.0. RESULTS: Totally 403 patients were studied. Only 56% patients showed signs of envenomation; among this most common is the cellulitis which accounts for the 36.4% of patients. Study also showed those who were presenting late had increased morbidity and mortality and their stay in the hospital also prolonged. It also showed that almost 5% patients still underwent some form of unauthorized treatment before seeking the medical care. Increase in age is associated with bad outcome. The study also showed 21% of all patients who had snake bite developed complications; the most common was the compartment syndrome accounted for (8.9%). Only in 46% of cases the snake was identified and the Russell’s viper is the commonest snake responsible for most of the bites. CONCLUSION: Late visit following snake bite is the most important factor which inversely affects the outcome following snake bite. Other factors which contributes to poor outcome includes, old age, Diabetes, native treatment, presence of signs of envenomation on admission and development of complications

Inferring stabilizing mutations from protein phylogenies : application to influenza hemagglutinin

One selection pressure shaping sequence evolution is the requirement that a protein fold with sufficient stability to perform its biological functions. We present a conceptual framework that explains how this requirement causes the probability that a particular amino acid mutation is fixed during evolution to depend on its effect on protein stability. We mathematically formalize this framework to develop a Bayesian approach for inferring the stability effects of individual mutations from homologous protein sequences of known phylogeny. This approach is able to predict published experimentally measured mutational stability effects (ΔΔG values) with an accuracy that exceeds both a state-of-the-art physicochemical modeling program and the sequence-based consensus approach. As a further test, we use our phylogenetic inference approach to predict stabilizing mutations to influenza hemagglutinin. We introduce these mutations into a temperature-sensitive influenza virus with a defect in its hemagglutinin gene and experimentally demonstrate that some of the mutations allow the virus to grow at higher temperatures. Our work therefore describes a powerful new approach for predicting stabilizing mutations that can be successfully applied even to large, complex proteins such as hemagglutinin. This approach also makes a mathematical link between phylogenetics and experimentally measurable protein properties, potentially paving the way for more accurate analyses of molecular evolution

GENETIC DIVERSITY ANALYSIS OF ACID LIME (CITRUS AURANTIFOLIA SWINGLE) CULTIVARS

Acid lime (Citrus aurantifolia Swingle) is an important commercial fruit crop, cultivated in our country. High variation of acid lime fruits are observed in existing varieties due to crossing within the other acid lime accessions. Determination of genetic variation is important to the plant breeders for development of high yielding variety. Therefore, an attempt has been made to study the genetic diversity of 6 acid lime varieties, maintained in our orchard. Ten Random amplified polymorphic DNA (RAPD) primers were used to assess the genetic diversity of acid lime. The average genetic similarity level among the 6 varieties was 60.5%, separated four major cluster groups. Total of 76 alleles of which 35 were polymorphic detected by ten primers RAPD markers. The Jaccard coefficient was used to calculate the genetic similarity. UPGMA was used to generate the dendrogram which clearly showed that the six acid lime varieties formed four clusters. Among the different clusters, the cluster size varied from 2 (cluster I and III) to 1 (cluster II, IV). The cluster I consisted of PKM -1 and Vikram. The cluster II consisted of Saisarbathi. The cluster III consisted of Pramalini and Tenali. The cluster IV consisted of Kasipentla. Among the cultivars, Pramalini and Tenali showed nearly 92% similarity followed by PKM-1 and Vikram which showed nearly 80% similarity. Kasipentala showed nearly 58% similarity, and Saisarbathi nearly 46% similarity. RAPD are highly polymorphic and more informative for the assessment of genetic diversity of acid lime varieties

Investigations on Electrochemical Micro Drilling of Nickel Alloy using Taguchi based Grey Approach

Inconel 600 is the nickel based super alloy which is employed in numerous engineering applications like gas turbine blades, turbochargers and heat exchangers etc. However, it is very difficult to machine due to its high strength and poor thermal diffusion. Conventional machining methods of these materials may result in decreased life time. An electrochemical machining is an advanced non-traditional technique which is suitable for machining hard material, strenuous materials and Intricate shapes. In this paper, electrochemical micro drilling (ECMD) on Inconel 600 material is investigated. The experiments are devised and analyzed using Taguchi’s L18 orthogonal array and Grey relational analysis (GRA). Analysis of variance (ANOVA) has been implemented to find out the significance of electrochemical micro drilling parameters on the performance characteristics

SYNTHESIS, CHARACTERIZATION AND ANTIBACTERIAL ACTIVITY OF NANO ZERO-VALENT IRON IMPREGNATED CASHEW NUT SHELL

Objective: The present study is focussed on the synthesis and evaluation of the antibacterial activity of nano zero-valent iron (NZVI) impregnated cashew nut shell (NZVI-CNS). Antibacterial activity was determined by adopting agar well diffusion method against selected bacteria.Methods: The preparation was carried out by simple liquid-phase reduction method, namely, borohydride reduction method. The anti-bacterial activity of the NZVI-CNS was studied against by adopting well diffusion assay method. Superparamagnetism behaviour has been studied using a permanent bar ferro magnet.Results: The nanoparticles obtained have been characterized with various techniques like Scanning Electron Microscopy (SEM) and Transmission Electron microscope (TEM) analyses. These techniques showed that the formations of NZVI with an average size of 50 to 100 nm and also it was found to be hexagonal and spherical in shape. The obtained NZVI impregnated CNS exhibits better superparamagnetism phenomenon. The synthesized cashew nut shell impregnated NZVI had the potential to inhibit the bacterial strains Escherichia coli, Klebsiella and Serratia marcescens.Conclusion: The synthesis process for NZVI nanoparticles impregnated CNS is simple, cost-effective, and eco-friendly. The synthesized NZVI impregnated CNS had the greater potential as effective growth inhibitors in the various microorganisms and this can be applied to the diverse pharmacological applications.Â

Land use and cropping pattern dynamics under the climate change regime

Climate change poses profound challenges to agricultural landscapes, disrupting farming regions through unpredictable rainfall patterns, extreme temperatures and other adverse environmental conditions. Climatic and institutional factors critically influence land use and cropping patterns, necessitating comprehensive studies to understand agricultural transformations. The study examines changes in land use patterns and cropping systems in Coimbatore district, Tamil Nadu, from 2008-09 to 2022-23, employing a multi-dimensional analytical framework to assess the rationality of land use classifications and agricultural dynamics. Key findings reveal that net sown area declined by -0.67%, while traditional food crops experienced negative growth rates namely: cereals (-1.91%) and pulses (-4.10%). Oilseeds emerged as the most dominant crop group, displaying a positive growth rate of 0.58% with low instability. Permanent fallows increased by 3.37%, coinciding with decreased rainfall. The analysis showed a modest increase in non-agricultural land (0.26%) and a distinguishable trend towards tree-based agriculture (0.63%), indicating changes in land use practices. Land use transitions revealed that forest lands and permanent pastures have complete retention due to the combination of legal protections and natural constraints that limit land-use conversion. An expected 13.17% loss of net sown area to permanent fallow raises concerns about agricultural land degradation, posing a potential threat to food security. Green manure crops exhibited 54.41% retention with 20.86% growth rate reflects farmers’ adaptive strategies towards climate change. The findings underscore the intricate relationship between land use, cropping patterns and climate adaptation, calling for integrated policies that support climate-smart agriculture by providing targeted incentives while balancing urban development

2,4-Bis(4-fluoro­phen­yl)-3-aza­bicyclo­[3.3.1]nonan-9-one

In the title compound, C20H19F2NO, a crystallographic mirror plane bis­ects the mol­ecule, passing through the N, O and two C atoms of the central ring system. The mol­ecule exists in a twin-chair conformation with equatorial dispositions of the 4-fluoro­phenyl groups on both sides of the secondary amino groups; the dihedral angle between the aromatic ring planes is 28.67 (3)°