Hasil untuk "Analytical chemistry"

Zack Hassman, Oliver Reardon-Smith, Gokul Subramanian Ravi et al.

We present and open source a quantum circuit simulator tailored to chemistry applications. More specifically, our simulator can compute the Born-rule probabilities of samples obtained from circuits containing passive fermionic linear optical elements and controlled-phase gates. We support both approximate and exact calculation of probabilities, and for approximate probability calculation, our simulator's runtime is exponential only in the magnitudes of the circuit's controlled-phase gate angles. This makes our simulator useful for simulating certain systems that are beyond the reach of conventional state vector methods. We demonstrate our simulator's utility by simulating the local cluster unitary Jastrow (LUCJ) ansatz and integrating it with sample-based quantum diagonalization (SQD) to improve the accuracy of molecular ground-state energy estimates. Applied to a 52-qubit $N_2$ system, we observe accuracy improvements of up to $46\%$ over the baseline SQD implementation with negligible computational overhead. More generally, we highlight a regime in which our simulator achieves substantially superior latency scaling and exponentially superior memory scaling over a tensor network simulator and a state vector simulator. As an efficient and flexible tool for simulating quantum chemistry circuits, our simulator enables new opportunities for enhancing near-term quantum algorithms in chemistry and related domains.

Guangjian Zhang, Bohao Liu, Deqian Qiao et al.

Summary: Background: Previous targeted therapies for non-small cell lung cancer (NSCLC) have focused on targeting driver mutations (e.g., EGFR/ALK), leading to approximately 30–40% of patients with negative mutations lacking effective treatments. Therefore, there is an urgent need for innovative therapeutic strategies for these patients. Methods: CD26-targeted proteolysis-targeting chimeras (PROTACs: P4-1 to P4-4) were designed and synthesised. The binding strengths between degraders and CD26 were evaluated through surface plasmon resonance (SPR). The ternary complex formations were confirmed by NanoBRET™ live-cell ternary complex profiling assay. Driver-negative NSCLC (NCI-H460 and NCI-H1299) and BEAS-2B cells were used to study the degradation performances of degraders. The therapeutic efficacies of the optimal degrader (P4-3) were assessed via cell line-derived xenografts (CDX), in situ lung cancer and patient-derived organoids (PDOs) models. Mechanistic studies incorporated co-immunoprecipitation, immunofluorescence, reactive oxygen species (ROS)/DNA damage detection, apoptosis assays and transcriptomics. Findings: CD26 underwent clathrin-dependent endocytosis induced by P4-3 and ternary complex were formed before protein degradation. Degradation of CD26 by P4-3 resulted in the cytoplasmic translocation of membrane-bound adenosine deaminase (ADA), leading to adenosine depletion, mitochondrial ROS accumulation, metabolic stress, DNA damage, and intrinsic apoptosis in vitro, in vivo and in PDOs (negative mutations) models. Mechanistically, degradation of CD26 uniquely eliminates both its enzymatic activity and non-enzymatic functions, achieving a dual effect unattainable with conventional inhibitors. Interpretation: Targeted CD26 degradation represents a valuable therapeutic strategy for driver-negative NSCLC. And this approach also addresses the limitations of driver mutation-targeted based therapies, providing a promising method for NSCLC patients with negative mutations. Funding: This study was funded by the Key Research and Development Project of Shaanxi Province (2023-YBSF-292), the opening foundation (M2022-3) from Key Laboratory of Optic-Electric Sensing and Analytical Chemistry for Life Science, Ministry of Education, Qingdao University of Science and Technology, the National Natural Science Foundation of China (82102976, 52203337), the Youth Top Talent Program (11301223010722) from Xi’an Jiaotong University, the Key Research and Development Project of Shaanxi Province (2024SF-ZDCYL-02-09) and Capacity Improvement Plan of Shaanxi Health Committee (2024PT-09).

Atefeh Moezzi, Anastasiya Ushenkina, Anna Widgren et al.

Abstract Background Myalgic encephalomyelitis (ME) is a chronic, multisystem illness characterized by post-exertional malaise (PEM) and cognitive dysfunction, yet the molecular mechanisms driving these hallmark symptoms remain unclear. This study investigated haptoglobin (Hp) as a potential biomarker of PEM severity and cognitive impairment in ME, with a focus on Hp phenotypes and structural proteoforms. Methods A longitudinal case–control study was conducted in 140 ME patients and 44 matched sedentary healthy controls. In the discovery phase, global plasma proteomic profiling was performed in 61 ME patients and 20 controls before and after a standardized, non-invasive stress protocol in order to induce PEM. Associations between Hp levels, phenotype, and cognitive performance were assessed. In the validation phase, plasma Hp concentrations and proteoform composition were analyzed in an independent cohort of 89 ME patients and 24 controls using high-performance liquid chromatography (HPLC). Results ME patients demonstrated a significant reduction in Hp levels following post-exertional stress. Lower baseline Hp concentrations were associated with impaired cognitive performance. Hp phenotypes were differentially associated with symptom burden, with the Hp2-1 phenotype enriched in ME and linked to greater PEM severity and cognitive deficits compared to Hp1-1 and Hp2-2. HPLC analysis revealed altered Hp proteoform profiles in the Hp2-1 subgroup, including increased high-mass tetrameric and pentameric forms and shorter retention times indicative of structural changes. In contrast, the Hp1-1 phenotype was associated with milder symptoms and greater cognitive resilience. Conclusions These findings suggest that Hp phenotype and proteoform structure modulate the physiological response to post-exertion in ME, offering insight into the molecular basis of PEM and its clinical heterogeneity. Hp may serve as a translational biomarker for patient stratification and a potential therapeutic target to mitigate oxidative stress and cognitive dysfunction in ME.

Rafael Martin-Domenech, Karin I. Öberg, Guillermo M. Muñoz Caro et al.

Understanding the formation of carbonyl sulfide (OCS) in interstellar ices is key to constrain the sulfur chemistry in the interstellar medium (ISM), since it is the only ice S-bearing molecule securely detected thus far. Two general pathways for OCS formation have been proposed: sulfurization of CO (CO+S) and oxidation of CS (CS+O), but their relative contribution in interstellar ices remains unconstrained. We have evaluated the contribution of both pathways to OCS formation upon energetic processing in isotopically-labeled CO2:CS2 and CO:CS2 ice samples at 7-50 K. Our results indicated that formation of OCS through the CS+O pathway was more favorable than through the CO+S pathway, as previously suggested by theoretical calculations. In addition, its relative contribution increased at higher temperatures. Therefore, this pathway could play a role in the ice formation of OCS, especially in warm regions where CO is expected to be preferentially in the gas phase. At the same time, we have explored the chemistry of CS2-bearing, CO2-, CO-, and also H2O-rich ices, that could be relevant to the sulfur interstellar chemistry. We observed formation of a variety of S-bearing products in addition to OCS, including SO2, C3S2, and S2. However, a significant fraction of sulfur was not detected at the end of the experiments, and could be locked in long, undetectable sulfur allotropes, one of the potential carriers of the missing sulfur in the dense ISM.

Rana Salari, Mohammad Amjadi

Abstract This study presents an efficient chemiluminescence (CL) probe based on perovskite nanocrystals (NCs) for detection of L–cysteine (L–Cys). It consists of nickel–doped CsPbBr3 NCs embedded in the mesoporous SiO2 matrix as CL reagent and cerium (IV) as an oxidant in aqueous environment. The probe was designed for the highly selective determination of L–Cys based on its remarkable enhancing effect on the CL intensity. The colloidal nanocomposite of nickel–doped CsPbBr3 NCs@SiO2 with photoluminescence quantum yield of 58% was fabricated by ligand–assisted re–precipitation method and characterized by using UV–Vis absorption, FT–IR, X–ray diffraction, and transmission electron microscopy. The sensor was utilized to determine L–Cys in the linear concentration range of 20–300 nM with a detection limit of 12.8 nM. Direct chemical oxidation of Ni–doped CsPbBr3 NCs@SiO2 by Ce(IV) was the single cause of the formation of the excited-state NCs and subsequent production of CL. The developed probe provides outstanding selectivity towards L–Cys over structurally related compounds. Accurate determination of L–Cys in human serum samples was achieved without interference, and the results were confirmed by HPLC method.

S'busiso M Nkosi, Nokukhanya Thembane

Abstract Clay soils are rock‐decomposed materials comprised of both clay‐ and non‐clay‐like minerals. Clays' physiochemical and mineralogical composition determines their applicability use in cosmetics. Because of their high bioburden, they must be effectively characterized before being incorporated into cosmetics. The scope of the current study was to characterize two different samples of red and white clays for their physical, chemical and biological properties; mined from Durban, South Africa. Characterization was performed using techniques like X‐ray fluorescence, X‐ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscope, hydrogen potential, soil colour, oil absorption, swelling capacity, texture, bulk density, plastic and apparent viscosity, sun protection factor and microbiological analysis.

Anal R. Trivedi, Shalini S. Gupta, Vasumati I. Patel et al.

Background: It is frequently observed that dental students require so many consents to manage medically compromised patients, especially cardiovascular patients with periodontitis requiring dental treatment. Aims and Objectives: The present study aimed to assess the dental students’ knowledge, attitudes, and practices regarding the management of cardiovascular disease (CVD) patients with periodontitis requiring dental treatment. Material and Methods: The cross-sectional study was conducted among 611 dental undergraduate and postgraduate students (branches of Periodontology, Oral and Maxillofacial Surgery, Oral Medicine and Radiology, Endodontics, Prosthodontics, and Public Health and Dentistry) of central Gujrat. Self-administered structured questionnaires with 23 questions were distributed in pen-and-paper physical format. Statistical analysis for descriptive statistics like frequency, percentage, mean, standard deviation, confidence interval, one-way analysis of variance, post hoc test for multiple comparisons, Fisher’s exact test, and Pearson’s correlation has been done by MS Excel and STATA/IC-13. Results: As per the post hoc test, both groups of students have significantly different knowledge (-4.20210*, P = 0.028) and their practices (0.68632, P = 0.968) but no significant difference between their attitudes (-6.22828, P = 0.089). According to the Pearson correlation test, a weak positive/no relationship between knowledge, attitudes, and practice is reported in both study groups. There is a weak positive relation between knowledge and attitudes (0.270) and between knowledge and practices (0.121), and a similar relationship between their attitudes and practices (0.172) was observed in both groups. Conclusion: Correct knowledge, attitudes, and practices regarding dental management of CVD patients with periodontitis can reduce medical consent to improve the treatment quality of dental students.

Marika Sugimoto, Naoko Takahashi-Ando, Naoki Sasaki

Evaluation of anti-inflammatory drug on a two-way membrane-integrated microfluidic device (TMMD) is presented. Insertion of a porous membrane into a microfluidic device in a vertical direction and attachment of a cover glass to the lateral side of the microfluidic device enabled us to observe the device from two orthogonal directions. HaCaT, a human epidermal keratinocyte, was cultured in the TMMD. The localization of ZO-1, a tight junction protein, between the HaCaT cells was confirmed by immunohistochemical analysis. Permeability of the HaCaT cell layer increased after stimulation by potassium dichromate, whereas the pretreatment of the HaCaT by dexamethasone prior to the stimulation kept the permeability unchanged. Deoxynivalenol, an anti-inflammatory drug candidate, kept the permeability unchanged with lower concentrations compared to dexamethasone. We expect that the present TMMD is applicable to various anti-inflammatory drug candidates to evaluate their efficacy.

Xiangqian Li, Qin Wen, Jiannian Chen et al.

The presence of nitrite (NO₂⁻) in water and food leads to serious problems in public health and the environment. Therefore, it is important to develop a rapid and efficient method for the selective detection of NO₂⁻. In this work, the synthesis and characterization of magnetic Fe₃O₄@SiO₂-TbDPA nanoprobe have been carried out. The Fe₃O₄@SiO₂-TbDPA aqueous solution exhibits a strong green emission. Due to the addition of various concentrations of NO₂⁻ (0–100 μM), the fluorescence intensity has been suppressed. The nanoprobe Fe₃O₄@SiO₂-TbDPA exhibits excellent selectivity and sensitivity toward NO₂⁻ ions. Excellent linearity is obtained in the range of 5–80 μM with a detection limit of 1.03 μM. Furthermore, the presence of magnetic Fe₃O₄ nanoparticles in Fe₃O₄@SiO₂-TbDPA nanospheres will also facilitate the effective separation of Fe₃O₄@SiO₂-TbDPA from the aqueous solution. Our proposed strategy is expected to fabricate an organic-inorganic hybrid magnetic nanomaterial and can be used as an efficient sensor. It has been shown that this new strategy has numerous advantages, such as high stability, selectivity, and simplicity of operation. It demonstrates great potential for simple and convenient NO₂⁻ detection. It may expand to a variety of ranges in environmental monitoring and biomedical fields.

Paweł Stelmaszczyk, Ewa Gacek, Renata Wietecha-Posłuszny

A new methodology for the detection of ketamine, flunitrazepam, and diazepam in beverage samples by the dried sample spot method was developed. The method is characterized by very low LODs in all tested types of beverages (100 ng/mL for ketamine, 25 ng/mL for flunitrazepam and diazepam) and great precision at the concentration of 100 ng/mL for all analytes. The significant advantages of this method are the consumption of fewer amount of samples and the possibility of securing the beverage samples on DBS cards at room temperature. The proposed method was evaluated by the innovative WAC approach according to Green Analytical Chemistry. The results of the evaluation indicate the best results of this method in terms of analytical quality compared to the other methods from the literature, however other aspects such as green chemistry and economical are also good. The DBS/MAE/LC-MS method could be used for qualitative analysis for drugs detection in cases of date-rape drugs analysis.

Christina Nannou, Efthimia Kaprara, Savvina Psaltou et al.

The removal of contaminants of emerging concern (CECs) occurring in wastewater effluents, such as pharmaceutically active substances (PhACs) and personal care products, pose a big research challenge since they can be a major source of pollution for water bodies and a danger to public health. The objective of this work was to perform a comprehensive monitoring of a broad set of PhACs (>130) in a wastewater treatment plant (WWTP) close to Thessaloniki (Greece), as well as to evaluate the potential of heterogeneous catalytic ozonation for the removal of CECs from wastewater through a continuous flow system. The high-resolution mass spectrometry analysis revealed the highest average concentrations for irbesartan (1817 ng/L). Antihypertensives along with antibiotics, psychiatrics, and β-blockers were found to aggravate the effluents. Removal efficiency after conventional treatment was >30%. The results from catalytic ozonation unit operation indicate that the introduction of a proper solid material that acts as catalyst can enhance the removal of CECs. A preliminary risk assessment using the risk quotient (RQ) revealed that irbesartan and telmisartan entail high acute risk. The overall results underline the urgent need to incessantly monitor PhACs and expand the toxicological studies to establish the sublethal and chronic effects on aquatic organisms.

Yasmine Ahmed Sharaf, Sami El Deeb, Adel Ehab Ibrahim et al.

Following the spread of the COVID-19 pandemic crisis, a race was initiated to find a successful regimen for postinfections. Among those trials, a recent study declared the efficacy of an antiviral combination of favipiravir (FAV) and molnupiravir (MLP). The combined regimen helped in a successful 60% eradication of the SARS-CoV-2 virus from the lungs of studied hamster models. Moreover, it prevented viral transmission to cohosted sentinels. Because both medications are orally bioavailable, the coformulation of FAV and MLP can be predicted. The developed study is aimed at developing new green and simple methods for the simultaneous determination of FAV and MLP and then at their application in the study of their dissolution behavior if coformulated together. A green micellar HPLC method was validated using an RP-C18 core-shell column (5 μm, 150 × 4.6 mm) and an isocratic mixed micellar mobile phase composed of 0.1 M SDS, 0.01 M Brij-35, and 0.02 M monobasic potassium phosphate mixture and adjusted to pH 3.1 at 1.0 mL min⁻¹ flow rate. The analytes were detected at 230 nm. The run time was less than five minutes under the optimized chromatographic conditions. Four other multivariate chemometric model methods were developed and validated, namely, classical least square (CLS), principal component regression (PCR), partial least squares (PLS-1), and genetic algorithm–partial least squares (GA–PLS-1). The developed models succeeded in resolving the great similarity and overlapping in the FAV and MLP UV spectra unlike the traditional univariate methods. All methods were organic solvent-free, did not require extraction or derivatization steps, and were applied for the construction of the simultaneous dissolution profile for FAV tablets and MLP capsules. The methods revealed that the amount of the simultaneously released cited drugs increases up until reaching a plateau after 15 and 20 min for FAV and MLP, respectively. The greenness was assessed on GAPI and found to be in harmony with green analytical chemistry concepts.

Beatriz Juliana Yerena-Prieto, Monserrat Gonzalez-Gonzalez, Mercedes Vázquez-Espinosa et al.

Interest in phenolic compounds has recently increased due to their potential as antioxidant agents. Moringa leaves (<i>Moringa oleifera</i>) have a high content of phenolic compounds, which presents them as a promising source for the extraction of these compounds. However, it is necessary to use analytical techniques to identify and quantify their actual compound content to determine the quality of the raw material and the potential of the final product. Ultrasound assisted extraction is a green, rapid and environmentally friendly extraction technique that produces high quality extracts from natural products. Hence, the aim of this research is to optimize the variables of the ultrasound-assisted extraction (UAE) process for the extraction of moringa leaves using response surface methodology (RSM) to extract the main flavonoids using methanol as the extraction solvent. A Box–Behnken design (BBD) has been used to evaluate the effect of the ultrasound extraction process variables. Finally, the optimal extraction time in the range between 2 and 30 min was determined. The results revealed that the methanol concentration was the most influential variable. The optimal extraction time was established at 15 min. Six of the main flavonoids were quantified by UHPLC-DAD and identified by UHPLC-QToF-MS. The results confirmed that UAE is an efficient method for the extraction and subsequent analysis and quality control of the flavonoids that can be found in moringa leaves.

Nicholas C. Rubin, A. Eugene DePrince

p$^\dagger$q is a C++ accelerated Python library designed to generate equations for many-body quantum chemistry methods and to realize proof-of-concept implementations of these equations for rapid prototyping. Central to this library is a simple interface to define strings of second-quantized creation and annihilation operators and to bring these strings to normal order with respect to either the true vacuum state or the Fermi vacuum. Tensor contractions over fully-contracted strings can then be evaluated using standard Python functions ({\em e.g.}, \np's einsum). Given one- and two-electron integrals these features allow for the rapid implementation and assessment of a wide array of many-body quantum chemistry methods.

Nitesh Kumar, Satya N. Guin, Kaustuv Manna et al.

Topology, a mathematical concept, has recently become a popular and truly transdisciplinary topic encompassing condensed matter physics, solid state chemistry, and materials science. Since there is a direct connection between real space, namely atoms, valence electrons, bonds and orbitals, and reciprocal space, namely bands and Fermi surfaces, via symmetry and topology, classifying topological materials within a single-particle picture is possible. Currently, most materials are classified as trivial insulators, semimetals and metals, or as topological insulators, Dirac and Weyl nodal-line semimetals, and topological metals. The key ingredients for topology are: certain symmetries, the inert pair effect of the outer electrons leading to inversion of the conduction and valence bands, and spin-orbit coupling. This review presents the topological concepts related to solids from the viewpoint of a solid-state chemist, summarizes techniques for growing single crystals, and describes basic physical property measurement techniques to characterize topological materials beyond their structure and provide examples of such materials. Finally, a brief outlook on the impact of topology in other areas of chemistry is provided at the end of the article.

Gushu Li, Yunong Shi, Ali Javadi-Abhari

Computational chemistry is the leading application to demonstrate the advantage of quantum computing in the near term. However, large-scale simulation of chemical systems on quantum computers is currently hindered due to a mismatch between the computational resource needs of the program and those available in today's technology. In this paper we argue that significant new optimizations can be discovered by co-designing the application, compiler, and hardware. We show that multiple optimization objectives can be coordinated through the key abstraction layer of Pauli strings, which are the basic building blocks of computational chemistry programs. In particular, we leverage Pauli strings to identify critical program components that can be used to compress program size with minimal loss of accuracy. We also leverage the structure of Pauli string simulation circuits to tailor a novel hardware architecture and compiler, leading to significant execution overhead reduction by up to 99%. While exploiting the high-level domain knowledge reveals significant optimization opportunities, our hardware/software framework is not tied to a particular program instance and can accommodate the full family of computational chemistry problems with such structure. We believe the co-design lessons of this study can be extended to other domains and hardware technologies to hasten the onset of quantum advantage.

Sudarshan Kumar Chinna, Nannuri Pranavi Reddy, Yekula Thapaswini et al.

Introduction: Cone beam computed tomography (CBCT) has one of the most important roles for diagnosis in dentistry. Aim and Objectives: The aim of this study is to assess the level of knowledge and awareness toward the scope of digital imaging and CBCT, among dental practitioners in North Karnataka regions such as Bidar and Raichur city. Materials and Methods: A questionnaire study was carried out among 200 dental practitioners of North Karnataka (Bidar and Raichur). A specially designed structured questionnaire (13 in number) was administered to assess the knowledge of digital imaging and CBCT. Data were analyzed using Pearson's correlation coefficient test, and any P ≤ 0.05 was considered to be statistically significant. Results: A total of 200 dentists were selected for the study, among which 93.5% were reported that digital imaging is the most useful method compared to conventional method. About 91.0% of the dentists were aware of CBCT. Of 91.5% of the dentists preferred CBCT for three-dimensional imaging in the head and neck region. Among all, majority of dentists reported that all types of radiography will be used in digital imaging (45.0%). Conclusion: The current study showed that knowledge of dentist regarding digital imaging and CBCT was not satisfactory; therefore, participants require an understanding of the concepts behind CBCT and related technologies, making appropriate training essential for every member of the dental team.