Hasil untuk "Analytical chemistry"

Lachlan A. Bourke, Lachlan A. Bourke, Julien Slagboom et al.

Snake venom activity exhibits evolutionary patterns within genera and varies according to ecological niche. By examining venoms from species inhabiting distinct environments, niche-specific functional differences can be uncovered. Bothrops, a diverse and medically important Neotropical pit viper genus, shows known clade-specific differences in coagulotoxicity. Here, we expanded this framework by assessing intra-clade variation in cellular activity across twelve Bothrops species using a high-content fluorescence assay that simultaneously measures ion channel responses and membrane cytotoxicity. Most venoms induced rapid membrane damage and cell lysis, whereas arboreal species lacked both activities, suggesting reduced selection for these activities. In contrast, the terrestrial Bothrops mattogrossensis and Bothrops pauloensis, which are sister species inhabiting the Pantanal wetlands and outskirts, respectively, displayed unique intracellular calcium-modulatory effects in the absence of membrane disruption. High throughput venomics revealed candidate toxin families underlying these calcium responses. Our findings demonstrate niche-specific diversification of venom bioactivity and highlight Bothrops venoms as promising sources of pharmacological agents.

Shanmugalakshmi Subbiah, Theranirajan Ethiraj, Shankar Shanmugam Rajendran et al.

Background: Aging presents significant challenges to healthcare, particularly in the underdiagnosis of mental health conditions such as depression and anxiety. Non-pharmacological interventions like autogenic relaxation have been explored as potential therapeutic options for improving mental health outcomes in the elderly. Objective: This study aimed to determine the effectiveness of autogenic relaxation in reducing symptoms of depression and anxiety among elderly individuals and to examine its correlation with demographic and clinical variables. Methods: A quasi-experimental pre-test and post-test control group design was conducted with 120 elderly patients from the National Centre of Ageing in Guindy, Chennai. Participants were randomly assigned to either an experimental group, which underwent autogenic relaxation training, or a control group, which received standard care. Data were collected over four weeks using the Geriatric Depression Scale and the Geriatric Anxiety Scale. Results: Post-intervention analysis revealed significant reductions in symptoms of depression (60.47%) and anxiety (41.80%) in the experimental group, whereas no such improvements were observed in the control group. Furthermore, demographic factors such as age and education level showed a significant positive correlation with the intervention outcomes. Conclusion: Autogenic relaxation is an effective, low-risk intervention for improving geriatric mental health, particularly when tailored to individual demographic characteristics. These findings suggest its potential for wider implementation in elderly care settings.

Mariam Wasim Beniamin, Amira Mohamed Kessiba, Maha Abdelmonem Hegazy et al.

Abstract An ecofriendly, sensitive, selective, precise, and accurate HPLC method with fluorescence detection (FD) has been developed and validated for simultaneous determination of two hypertensive drugs, felodipine and metoprolol in their pure samples, combined pharmaceutical dosage form and in spiked human plasma. Separation was carried out on Inertsil C18 column (150 mm × 4.6 ID; Particle size 5 µm) and a mobile phase composed of ethanol and 30mM potassium dihydrogen phosphate buffer, adjusted to pH 2.5 using ortho-phosphoric acid (40:60, v/v) was used. A constant flow rate of 1.0 mL/min at an ambient temperature was adopted. Method validation was performed according to the ICH Q2 R2 and bioanalytical method validation was done according to FDA guidelines for determination of both drugs simultaneously in biological matrices. The method demonstrated excellent linearity over the concentration range of 0.01–1.00 µg/mL and 0.003–1.00 µg/mL that were selected with accordance to the Cmax of both drugs with a correlation coefficient (r2) of 0.9998 and 0.9999 for felodipine and metoprolol, respectively in human plasma. The intra-day and inter-day precision were ≤ 2% in their pure forms and in spiked human plasma, and the accuracy was within ± 2% of the nominal concentration for both drugs in their pure forms and within ± 10% of the nominal concentration in human plasma. A statistical comparison was conducted between the proposed method and the reported method; it showed no significant difference between both methods regarding both accuracy and precision. The proposed method proved to be eco-friendly with three green assessment tools (AGREE calculator, MoGAPI, RGBfast study). Graphical Abstract

Abdelkader Zarrouk, Amine Asserghine, Clément Trellu et al.

The accumulation of antiviral drugs, such as sofosbuvir (SOF), in aquatic environments raises growing concerns due to their persistence and potential ecological risks. This study addresses the need for effective degradation strategies by investigating the homogeneous electro-Fenton (EF) process in a Pt/carbon felt cell for the degradation and mineralization of SOF in an aqueous medium. A Box-Behnken design (BBD) was employed to optimize key operational parameters, including initial Fe2+ concentration, current intensity, and initial SOF concentration, targeting chemical oxygen demand (COD) removal as the main response. The model showed excellent predictability (R2 = 0.99), and the optimal conditions were identified as 400 mA current intensity, CSOF-0 = 0.1 mM, and CFe2+-0 = 0.1 mM. Under these conditions, 97% of SOF was degraded within 5 min, while complete mineralization was achieved within 5 h. Biodegradability tests revealed an increase in the BOD5/COD ratio to 0.41 after 2 h of electrolysis, indicating that the EF process can be effectively coupled with a biological treatment. The combined bio-electro-Fenton (bio-EF) approach successfully achieved complete mineralization, offering a cost-effective and sustainable strategy for the removal of recalcitrant pharmaceutical pollutants from water.

An-Jun Liu, Bryan K. Clark

The ground state of second-quantized quantum chemistry Hamiltonians is key to determining molecular properties. Neural quantum states (NQS) offer flexible and expressive wavefunction ansatze for this task but face two main challenges: highly peaked ground-state wavefunctions hinder efficient sampling, and local energy evaluations scale quartically with system size, incurring significant computational costs. In this work, we overcome these challenges by introducing a suite of algorithmic enhancements, which includes efficient periodic compact subspace construction, truncated local energy evaluations, improved stochastic sampling, and physics-informed modifications. Applying these techniques to the neural network backflow (NNBF) ansatz, we demonstrate significant gains in both accuracy and scalability. Our enhanced method surpasses traditional quantum chemistry methods like CCSD and CCSD(T), outperforms other NQS approaches, and achieves competitive energies with state-of-the-art ab initio techniques such as HCI, ASCI, FCIQMC, and DMRG. A series of ablation and comparative studies quantifies the contribution of each enhancement to the observed improvements in accuracy and efficiency. Furthermore, we investigate the representational capacity of the ansatz, finding that its performance correlates with the inverse participation ratio (IPR), with more delocalized states being more challenging to approximate.

H. E. Howe

M. Friedman

Mempally Hari Kumar, Vraj T. Patel, Shruti Vishal Dev et al.

This case report presents the clinical and technical aspects of fabricating and rehabilitating a patient with a custom-designed ocular prosthesis following enucleation due to ocular malignancy. The report details the patient’s history, clinical examination, and the step-by-step process of prosthesis fabrication. The aim is to highlight the importance of a multi-disciplinary approach involving ophthalmologists and maxillofacial prosthodontists in providing optimal esthetic and functional outcomes for patients with ocular defects.

Milica Jankov, Vincent Léguillier, Uroš Gašić et al.

<i>Agaricus bisporus</i>, commonly known as the button mushroom, has attracted attention for its biological properties, including antimicrobial activities. Here, we evaluated the efficacy of ethanolic and acetonic extracts from white and brown <i>A. bisporus</i> against different bacterial strains, including antibiotic-resistant strains. Bioautography and principal component analysis identified the most active antibacterial compounds for each of the tested bacteria and indicated the main markers responsible for the strain-specific effects. In addition, the mushroom extracts demonstrated a synergistic impact when combined with the antistaphylococcal antibiotic AFN-1252.

Mohd Zeeshan, Asim M. Khan, Md Sibgatullah et al.

Introduction: Human papillomavirus (HPV) has been implicated in several studies pertaining to oral squamous cell carcinoma (OSCC) in the last several decades. Infection with human papillomavirus (HPV), particularly HPV16 and 18, is the leading cause of squamous cell carcinoma of the neck (SCCHN). Methodology: We selected an adequate number of subjects with the same parameters for both the case and the controls based on detailed case histories, specifically taking into account the adverse habits (tobacco in any form and alcohol) that each subject had recorded. The subjects were selected from the Outdoor Patient Department of Kothiwal Dental College and Research Centre. Before commencing the experimental procedure, all the subjects had undergone blood examinations (HB%, CT, BT, RBS, HBsAg, HIV). Group 1 consisted of 40 subjects, whereas Group 2 had 20 subjects. Result: Human papillomaviruses (HPVs) play an important role in oral cancer, and this research demonstrated a substantial link between HPV-16 and HPV-18 and the disease. Although this research does not allow us to draw any conclusions about cause and effect, our results are consistent with and even expand upon those of previous case–control studies. The presence of HPV causes molecular damage in cells, thereby resulting in cell proliferation and malignant conversions. Therefore, we can conclude that the human papillomavirus significantly contributes to carcinogenesis. Conclusion: Although the current results are based on a limited sample, they provide strong evidence that a larger study of individuals with head and neck cancer is necessary to make firm conclusions.

Neda Bagheri, V. Mazzaracchio, S. Cinti et al.

The growth of (bio)sensors in analytical chemistry is mainly attributable to the development of affordable, effective, portable, and user-friendly analytical tools. In the field of sensors, paper-based devices are gaining a relevant position for their outstanding features including foldability, ease of use, and instrument-free microfluidics. Herein, a multifarious use of filter paper to detect copper ions in bodily fluids is reported by exploiting this eco-friendly material to (i) synthesize AuNPs without the use of reductants and/or external stimuli, (ii) print the electrodes, (iii) load the reagents for the assay, (iv) filter the gross impurities, and (v) preconcentrate the target analyte. Copper ions were detected down to 3 ppb with a linearity up to 400 ppb in standard solutions. The applicability in biological matrices, namely, sweat and serum, was demonstrated by recovery studies and by analyzing these biofluids with the paper-based platform and the reference method (atomic absorption spectroscopy), demonstrating satisfactory accuracy of the novel eco-designed analytical tool.

Tatyana Stefanovska, Andrzej Skwiercz, Valentina Pidlisnyuk et al.

Analysis of the nematode community has been considered a key indicator of soil health. In this study, the assessment of nematodes was performed two times during the third growing season in soil contaminated by chemical elements where <i>Miscanthus × giganteus</i> was cultivated in the years 2019–2022. A morphological approach was used to identify the nematode communities that showed sensitivity to the level of soil contamination. In contrast, the value of <i>M</i> × <i>g</i> dry biomass was a more conservative indicator and displayed only a small yield, which decreased (3.6%) at the highest level of soil contamination by lead to 290.5 ± 75.4 µg/g. Principal component analysis revealed four trends associated with the coherent variability of contamination in soil and various organs of <i>M</i> × <i>g</i>. The variability of elements was reflected by the first three principal components and did not affect the nematode community. The variability of lead concentration was associated with principal component 4, which was the largest driver of changes in the nematode community. The trophic structure of the nematode communities was the most sensitive to soil contamination by lead. A decrease in the Structural Index was the general indicator in the transformation of the nematode community structure due to increasing levels of soil contamination.

Brianna Lacy, Adam Burrows

Y dwarfs are the coolest spectral class of brown dwarf. They have effective temperatures less than 500 K, with the coolest detection as low as ~250 K. Their spectra are shaped predominantly by gaseous water, methane, and ammonia. At the warmer end of the Y dwarf temperature range, spectral signatures of disequilibrium carbon monoxide have been observed. Cooler Y dwarfs could host water clouds in their atmospheres. Since they make up the low-mass tail of the star formation process, and are a valuable analogue to the atmospheres of giant gaseous exoplanets in a temperature range that is difficult to observe, understanding Y dwarf atmospheric compositions and processes will both deepen our understanding of planet and star formation, and provide a stepping stone towards characterizing cool exoplanets. JWST spectral observations are anticipated to provide an unprecedented level of detail for these objects, and yet published self-consistent model grids do not accurately replicate even the existing HST and ground-based observations. In this work, we present a new suite of 1-d radiative-convective equilibrium models to aid in the characterization of Y dwarf atmospheres and spectra. We compute clear, cloudy, equilibrium-chemistry and disequilibrium-chemistry models, providing a comprehensive suite of models in support of the impending JWST era of panchromatic Y dwarf characterization. Comparing these models against current observations, we find that disequilibrium CH4-CO and NH3-N2 chemistry and the presence of water clouds can bring models and observations into better, though still not complete, agreement.

M. Pumera, A. Loo

S. Hashimoto, D. Werner, T. Uwada

Lili Ma, Jiangping Liu

In order to realize the real-time and accurate prediction of dissolved oxygen concentration in the sewage treatment process, a prediction model of dissolved oxygen concentration in the sewage treatment process based on a data identification algorithm was proposed. Combined with the data characteristics of the sewage treatment process, a new sample similarity measure is defined to extract more representative modeling data. In the improved algorithm, in order to improve the quality of the initial members of the basic fireworks algorithm, the chaos algorithm is integrated. The search mechanism of the basic fireworks algorithm is improved, and the optimization process is divided into two stages based on the set criteria, and two groups are used simultaneously. The results show that compared with the basic FWA algorithm, the CFWA algorithm makes better use of the chaotic search mechanism. On the one hand, it avoids the excessive random or blind selection of the initial weight threshold of the neural network in the initial stage; on the other hand, in the optimization process of the weight threshold, two types of search mechanisms, FWA and COA, are used to give full play to their respective strengths and to continuously conduct information exchange and mutual cooperation between groups and individuals. The number of times is better than the basic FWA algorithm, and the training error and generalization error of the CFWA model in the simulation results of the soft sensor model are also better than those of the FWA model, which fully verifies the effectiveness of the CFWA algorithm. It is proved that the data recognition algorithm can effectively predict sewage treatment. It is proved that the data recognition algorithm can effectively predict the dissolved oxygen concentration in wastewater treatment process. It provides a new measurement method for some key process variables that cannot be measured or are difficult to measure in complex chemical processes.

Olga N. Sekurova, Martin Zehl, Michael Predl et al.

ABSTRACT The species Streptomyces venezuelae is represented by several distinct strains with variable abilities to biosynthesize structurally diverse secondary metabolites. In this work, we examined the effect of ethanol shock on the transcriptome and metabolome of Streptomyces venezuelae NRRL B-65442 using high-throughput RNA sequencing (RNA-seq) and high-resolution liquid chromatography-tandem mass spectrometry (LC-MS/MS). Ethanol shock caused massive changes in the gene expression profile, differentially affecting genes for secondary metabolite biosynthesis and central metabolic pathways. Most of the data from the transcriptome analysis correlated well with the metabolome changes, including the overproduction of jadomycin congeners and a downshift in the production of desferrioxamines, legonoxamine, foroxymithin, and a small cryptic ribosomally synthesized peptide. Some of the metabolome changes, such as the overproduction of chloramphenicol, could not be explained by overexpression of the cognate biosynthetic genes but correlated with the expression profiles of genes for precursor biosynthesis. Changes in the transcriptome were also observed for several genes known to play a role in stress response in other bacteria and included at least 10 extracytoplasmic function σ factors. This study provides important new insights into the stress response in antibiotic-producing bacteria and will help to understand the complex mechanisms behind the environmental factor-induced regulation of secondary metabolite biosynthesis. IMPORTANCE Streptomyces spp. are filamentous Gram-positive bacteria known as versatile producers of secondary metabolites, of which some have been developed into human medicines against infections and cancer. The genomes of these bacteria harbor dozens of gene clusters governing the biosynthesis of secondary metabolites (BGCs), of which most are not expressed under laboratory conditions. Detailed knowledge of the complex regulation of BGC expression is still lacking, although certain growth conditions are known to trigger the production of previously undetected secondary metabolites. In this work, we investigated the effect of ethanol shock on the production of secondary metabolites by Streptomyces venezuelae and correlated these findings with the expression of cognate BGCs and primary metabolic pathways involved in the generation of cofactors and precursors. The findings of this study set the stage for the rational manipulation of bacterial genomes aimed at enhanced production of industrially important bioactive natural products.

Hemraj Sharma1, Hari Prasad Sapkota1, Roshani Bhattarai et al.

The use of sanitizers in the COVID19 pandemic is very common. While using sanitizers in Nepal, we have found people having problems with skin irritation and rashes; hence it was felt to know the amount of glycerol used as an emollient. A validated UV visible spectrophotometric and Reverse-phase High-performance liquid chromatography (RP-HPLC) method was designed to determine the amount of glycerol in the locally available sanitizers. The glycerol in sanitizers showed variation in amount, ranging from 0.78 to 1.66 g and 0.75 to 1.62 g/100 mL by HPLC and UV, respectively. The sanitizer samples with less purity or failed to meet the specification limit should be withdrawn, and their use must be limited. Hence this method seems to be easy, reliable, and cost-effective for determining glycerol based on the chemical derivatization technique.

Gandova Vanya, Petrova Ivalina, Tasheva Stanislava et al.

The emulsion stability of different pumpkin O/W emulsions was investigated. Preparation of emulsions were performed with oil phase between 10 and 40 percent, water and soybean protein isolate. To determine emulsion properties different methods were used. Density, viscosity, centrifugation tests and spectroscopic measurements were performed for their investigations. The emulsions were stored for two weeks to determine their kinetic. Influence of the oil phase was presented and connected with the stability of them.

Terje Grøntoft, Tine Frøysaker

Abstract The historical (1835–2020) deposition of major air pollutants (SO2, NOx, O3 and PM2.5) indoors, as represented by the monumental Edvard Munch paintings (c. 220 m2) installed in 1916 in the Oslo University Aula in Norway, were approximated from the outdoor air concentrations, indoor to outdoor concentration ratios and dry deposition velocities. The annual deposition of the pollutants to the paintings was found to have been 4–25 times lower than has been reported to buildings outdoors in the urban background in the centre of Oslo. It reflected the outdoor deposition but varied less, from 0.3 to 1.2 g m−2 a−1. The accumulated deposition since 1916, and then not considering the regularly performed cleaning of the paintings, was found to have been 43 ± 13 g m−2, and 110 ± 40 g m−2 in a similar situation since 1835. The ozone deposition, and the PM2.5 deposition before the 1960s, were a relatively larger part of the accumulated total indoor (to the paintings) than reported outdoor deposition. About 18 and 33 times more O3 than NOx and PM2.5 deposition was estimated to the paintings in 2020, as compared to the about similar reported outdoor dry deposition of O3 and NOx. The deposition of PM2.5 to the paintings was probably reduced with about 62% (50–80%) after installation of mechanical filtration in 1975 and was estimated to be 0.011 (± 0.006) g m−2 in 2020. Graphical Abstract