Hasil untuk "Analytical chemistry"

F. S. Chakar, A. Ragauskas

M. Sporn, A. Roberts, D. Goodman

M. Nocita, A. Stevens, B. van Wesemael et al.

Arghyadeb Roy, Brandt A. L. Gaches, Jonathan C. Tan

The chemistry of shielded molecular gas is primarily driven by energetic, charged particles dubbed cosmic rays (CRs), in particular those with energies under 1 GeV. CRs ionize molecular hydrogen and helium, the latter of which contributes greatly to the destruction of molecules. CR ionization initiates a wide range of gas-phase chemistry, including pathways important for the so-called "carbon cycle", C$^+$/C/CO. Therefore, the CR ionization rate, $ζ$, is fundamental in theoretical and observational astrochemistry. Although observational methods show a wide range of ionization rates -- varying with the environment, especially decreasing into dense clouds -- astrochemical models often assume a constant rate. To address this limitation, we employ a post-processed gas-phase chemical model of a simulated dense molecular cloud that incorporates CR energy losses within the cloud. This approach allows us to investigate changes in abundance profiles of important chemical tracers and gas temperature. Furthermore, we analyze analytical calibrators for estimating $ζ$ in dense molecular gas that are robust when tested against a full chemical network. Additionally, we provide improved estimations of the electron fraction in dense gas for better consistency with observational data and theoretical calibrations for UV-shielded regions.

Yoshiaki Endo, Yasuto Watanabe, Kazumi Ozaki

The abundances of atmospheric carbon species--carbon dioxide (CO2), carbon monoxide (CO), and methane (CH4)--exert fundamental controls on the climate, redox state, and prebiotic environment of terrestrial planets. As exoplanet atmospheric characterization advances, it is essential to understand how these species are regulated on habitable terrestrial planets across a wide range of stellar and planetary conditions. Here, we develop an integrated numerical model that couples atmospheric chemistry, climate, and the long-term carbon cycle to investigate the atmospheric compositions of lifeless, Earth-like planets orbiting Sun-like (F-, G-, and K-type) stars. Our simulations demonstrate that CO2, CO, and CH4 generally increase with orbital distance, and that planets near the outer edge of the habitable zone may undergo CO runaway--a photochemical instability driven by severe depletion of OH radicals. The threshold for CO runaway depends strongly on stellar spectral type and is most easily triggered around cooler, lower-mass stars. In contrast, the atmospheric production of formaldehyde (H2CO)--a key precursor for prebiotic organic chemistry--peaks around planets orbiting more massive, UV-luminous stars and is maximized at orbital distances just interior to the CO-runaway threshold. These results establish a quantitative framework linking observable system properties--stellar type and orbital distance--and the atmospheric carbon chemistry of lifeless Earth-like planets, providing new context for interpreting future spectroscopic observations and for evaluating the potential of such planets to sustain prebiotic chemistry.

Nishath Sayed Abdul, Teef Adel Gholoum, Latefah Abdulrahman Alali et al.

Background: Type 2 diabetes mellitus, with increasing global prevalence and genetic influence, may be predicted using dermatoglyphics, a reliable forensic tool. This study evaluated dermatoglyphic patterns to identify type 2 diabetes in the Kuwaiti population. Materials and Methods: A cross-sectional observational study with 100 participants (50 diabetics, 50 controls) analysed fingerprint patterns (loops, whorls, arches). Results: 500 fingerprints were examined (250 diabetic, 250 control). Among diabetics, there were 21 males (42%) and 29 females (58%), while the control group included 20 males (40%) and 30 females (60%). The diabetic group showed a predominant loop pattern (48%), whereas the control group commonly exhibited the whorl pattern. Diabetic males mostly showed loops, and non-diabetic males showed whorls. Diabetic females had predominantly whorl patterns, while non-diabetic females showed loops. Conclusion: Loop patterns were more frequent in diabetics, while the whorls were common in non-diabetics, indicating predictive potential for type 2 diabetes.

Yi Liu, Zong-Geng Li, Hao Cheng et al.

Rice (Oryza sativa L.) plays a pivotal role in global food security, yet its breeding is constrained by its long generation time and seasonality. To enhance rice breeding efficiency and meet future food demands, we have developed a vertical hydroponic breeding system integrated with light-emitting diodes (LEDs) lighting in a closed plant factory (PF), which significantly accelerates rice growth and generation advancement. The results show that indica rice can be harvested as early as after 63 days of cultivation, a 50% reduction compared with field cultivation, enabling the annual harvesting of 5–6 generations within the PF. A hyperspectral imaging (HSI) system and attenuated total reflectance (ATR) infrared (IR) spectroscopy were further employed to characterize the chemical composition of the PF- and field-cultivated rice. Metabolomics analysis with ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) and gas chromatography-mass spectrometry (GC-MS) revealed that, compared with the field-cultivated rice, the PF-cultivated rice exhibited an up-regulation of total phenolic acids along with 68 non-volatile and 19 volatile metabolites, such as isovitexin, succinic acid, and methylillicinone F. Overall, this study reveals the unique metabolic profile of PF-cultivated rice and highlights the potential of PFs to accelerate the breeding of crops such as rice, offering an innovative agricultural strategy to support food security in the face of global population growth and climate change.

Ayoub Hafid, Hokuto Iwakiri, Kento Tsubouchi et al.

Significant advances have been made in the study of quantum advantage both in theory and experiment, although these have mostly been limited to artificial setups. In this work, we extend the scope to address quantum advantage in tasks relevant to chemistry and physics. Specifically, we consider the unitary cluster Jastrow (UCJ) ansatz-a variant of the unitary coupled cluster ansatz, which is widely used to solve the electronic structure problem on quantum computers-to show that sampling from the output distributions of quantum circuits implementing the UCJ ansatz is likely to be classically hard. More specifically, we show that there exist UCJ circuits for which classical simulation of sampling cannot be performed in polynomial time, under a reasonable complexity-theoretical assumption that the polynomial hierarchy does not collapse. Our main contribution is to show that a class of UCJ circuits can be used to perform arbitrary instantaneous quantum polynomial-time (IQP) computations, which are already known to be classically hard to simulate under the same complexity assumption. As a side result, we also show that UCJ equipped with post-selection can generate the class post-BQP. Our demonstration, worst-case nonsimulatability of UCJ, would potentially imply quantum advantage in quantum algorithms for chemistry and physics using unitary coupled cluster type ansatzes, such as the variational quantum eigensolver and quantum-selected configuration interaction.

J. Bhuvaneswarri, Julius Amaldas, Vidhya Rekha Umapathy et al.

Periodontal disease, a prevalent oral health condition, involves a complex microbial community. Advanced sequencing technologies have enabled in-depth studies of the oral microbiome, focusing on specific bacterial taxa like TM7. This systematic review analyzes the role of TM7 in the oral microbiome and its implications for periodontal disease. This review underscores TM7’s importance in the oral microbiome and its potential as a target for future research on periodontal disease pathogenesis.

Qi-Ju Shao, Yan Wang, Xi-Jin Yang et al.

Gnaphalium affine is a plant with various active properties and has been approved for use as a traditional medicine and food ingredient. In this study, liquid chromatography with electrochemical detection was utilized to separate the antioxidant compounds of G. affine, in conjunction with liquid chromatography-triple quadrupole mass spectrometry for identification. The in vitro antioxidant activity of G. affine was evaluated using DPPH and ABTS radical scavenging capacity assays, as well as the ferric reducing antioxidant power assay. The results showed that a total of 25 antioxidant compounds were screened and identified, among which 14 compounds were quantitatively analyzed. G. affine was found to be rich in phenolic substances, with the total phenolic content ranging from 14.62 to 59.30 mg GAE/g DW, which exhibited high antioxidant potential. The antioxidant activities showed a strong positive correlation with the total phenolic content (r > 0.9). The predominant phenolic compounds in G. affine were 5-O-caffeoylquinic acid, 3-O-caffeoylquinic acid, ferulic acid, luteolin-7-O-glucoside, 3,5-O-dicaffeoylquinic acid, 1,5-O-dicaffeoylquinic acid, and luteolin, with 3,5-O-dicaffeoylquinic acid and 1,5-O-dicaffeoylquinic acid exhibiting the highest levels. Statistical analysis indicated that monosubstituted caffeoylquinic acids, disubstituted caffeoylquinic acids, and luteolin derivatives strongly correlated with the antioxidant potential. This study identified and quantified the major chemical constituents responsible for the antioxidant properties of G. affine, demonstrating its potential as a natural source of antioxidants for the use in foods, pharmaceuticals, and health products.

Thibault Cavalié, Ladislav Rezac, Raphael Moreno et al.

The localized delivery of new long-lived species to Jupiter's stratosphere by comet Shoemaker-Levy 9 in 1994 opened a window to constrain Jovian chemistry and dynamics by monitoring the evolution of their vertical and horizontal distributions. However, the spatial distributions of CO and HCN, two of these long-lived species, had never been jointly observed at high latitudinal resolution. Atacama large millimeter/submillimeter array observations of HCN and CO in March 2017 show that CO was meridionally uniform and restricted to pressures lower than 3 $\pm$ 1 mbar. HCN shared a similar vertical distribution in the low- to mid-latitudes, but was depleted at pressures between 2$^{+2}_ {-1}$ and 0.04$^{+0.07}_{-0.03}$ mbar in the aurora and surrounding regions, resulting in a drop by two orders of magnitude in column density. We propose that heterogeneous chemistry bonds HCN on large aurora-produced aerosols at these pressures in the Jovian auroral regions causing the observed depletion.

Chunmei Li, Jinyuan Zhou, Di Wang et al.

Amide proton transfer (APT) magnetic resonance imaging (MRI) is an important molecular imaging technique at the protein level in tissue. Neurodegenerative diseases have a high likelihood of causing abnormal protein accumulation in the brain, which can be detected by APT MRI. This article briefly introduces the principles and image processing technology of APT MRI, and reviews the current state of research on Alzheimer's disease and Parkinson's disease using this technique. Early applications of this approach in these two neurodegenerative diseases are encouraging, which also suggests continued technical development and larger clinical trials to gauge the value of this technique.

Fábio R.P. Rocha

Abdulrahman M Alshahrani

Background: Spasticity is a pathophysiological outcome of impaired muscle motor activity, primarily the muscle tone. Muscle tone problems are signs of several neurological conditions, such as multiple sclerosis, movement disorders, spine damage, stroke, and traumatic brain injury. Antispasticity therapeutics belong to a class of treatments that restore motor function and muscle tone. There are several routes of therapeutic administration of antispastic medications; among them, the oral drug delivery system plays a significant role. Objective: The purpose of the study was to present a complete synthesis of the scientific evidence on the safety and efficacy of antispasticity medicines used orally for the management of nonprogressive neurological disorders. Materials and Methods: In order to carry out a comprehensive meta-analysis, the most pertinent scientific studies on the use of oral antispasticity medications to treat non-progressive neurological illnesses were identified. A search was conducted across a number of databases, including SciELO, Cochrane Central Register of Controlled Trials (CENTRAL), and PubMed. MedCalc statistical software was used to perform a meta-analysis in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) standards for odds ratio across the studies, relative risk, and risk factor analysis. Results: In the present study, a total of 252 original records were retrieved from different predefined databases on oral antispasticity drugs and their association with non-progressive neurological disorders. After several screening steps, 12 studies were found to be eligible for meta-analysis. These studies represented different antispasticity therapeutics that were administered via the oral route. Based on the meta-analysis, oral antispasticity drugs were found to be moderately effective (P < 0.001). Conclusion: The findings of the meta-analysis showed that the interventions of tizanidine, diazepam, dantrolene, baclofen, and gabapentin were more effective in tackling spasticity than the control. Therefore, in the treatment of non-progressive neurological diseases, oral antispasticity medications are only modestly effective.

Elisabeta Kafia, Silva Ibrahimi, Ervin Ibrahimi

Introduction: Political appeal and social pressure, combined with law ambiguity and lack of resources, to avoid the hard decisions, often have brought to a simplified model of inclusive education and to an apparently simplistic solution: opting for the location of education for children with special educational needs and dis¬abilities instead of tackling the routes of the problem. Scope: Within this context, the current research aims to explore the fundamental characteristics of inclusive education, highlighting the bio-psycho-social evidence-based approach in education. Method: The method applied in the present work is explorative-reflective research on what can be regarded as inclusive education, education for all, and social capital psychoeducation as benchmarks for an integrative society. Findings and Conclusions: This research concludes that the inclusive education is not an emergency-adaptive pedagogy but has to be conceived as a medical psycho-pedagogy of raising awareness in healthy personalities and social inclusion, not shunning differences but observing them and seeking to offer to everyone the best opportunities for personal and community growth. Compared to the traditional concept of inclusion, the theoretical perspective of evidence-based approach has a much broader scope and it embraces the fact that inclusive education carries intrinsically also a risk of exclusion that must be actively prevented, and at the same time affirms the importance of involving all actors in creating a truly welcoming community, which must become sensitive to the full range of differences present in children's life.

Madhu Ranjan, Mritunjay Kumar Keshari, Tushar Sinha et al.

Introduction: Salivary substitutes are gaining popularity these days because of the increase in patients with dry mouth. These substitutes must satisfy certain criteria to fulfill the patient's needs. One of these is wettability. Materials and Methods: One hundred fifty rectangular specimens of heat-cured denture base acrylic resin were prepared. A drop of test liquids (human saliva, distilled water, aqwet, saleva, and wet mouth) was placed over the test specimen and right and left contact angles were measured using optical contact angle machine. Results: All test liquids performed better than distilled water. Human saliva has the least contact angle followed by aqwet. Conclusion: Carboxymethyl cellulose base aqwet saliva substitute was found to be best having similar contact angle values to human saliva.

Davide Materia, Leonardo Ratini, Celestino Angeli et al.

Hardware-efficient empirical variational ansätze for Variational Quantum Eigensolver simulations of Quantum Chemistry suffer from the lack of a direct connection to classical Quantum Chemistry methods. In the present work, we propose a method to fill this gap by introducing a new approach for constructing variational quantum circuits, leveraging quantum mutual information associated with classical Quantum Chemistry states to design simple yet effective heuristic ansätze with a topology that reflects the correlations of the molecular system. As first step, Quantum Chemistry calculations, such as Møller-Plesset (MP2) perturbation theory, firstly provide an approximate Natural Orbitals basis, which has been recently shown to be the best candidate one-electron basis for developing compact empirical wavefunctions (Ratini, et al 2023). Secondly, throughout the evaluation of quantum mutual information matrices, they provide information about the main correlations between qubits of the quantum circuit, enabling the development of a direct design of entangling blocks for the circuit. The resulting ansatz is then utilized with a Variational Quantum Eigensolver (VQE) to obtain a short depth variational groundstate of the electronic Hamiltonian. To validate our approach, we perform a comprehensive statistical analysis by simulations over various molecular systems ($H_2, LiH, H_2O$) and apply it to the more complex $NH_3$ molecule. The reported results demonstrate that the proposed methodology gives rise to highly effective ansätze, surpassing the standard empirical ladder-entangler ansatz in performance. Overall, our approach can be used as effective state preparation providing a promising route for designing efficient variational quantum circuits for large molecular systems.

Jakob Günther, Alberto Baiardi, Markus Reiher et al.

Quantum computation is one of the most promising new paradigms for the simulation of physical systems composed of electrons and atomic nuclei, with applications in chemistry, solid-state physics, materials science, and molecular biology. This requires a truncated representation of the electronic structure Hamiltonian using a finite number of orbitals. While it is, in principle, obvious how to improve on the representation by including more orbitals, this is usually unfeasible in practice (e.g., because of the limited number of qubits available) and severely compromises the accuracy of the obtained results. Here, we propose a quantum algorithm that improves on the representation of the physical problem by virtue of second-order perturbation theory. In particular, our quantum algorithm evaluates the second-order energy correction through a series of time-evolution steps under the unperturbed Hamiltonian. An important application is to go beyond the active-space approximation, allowing to include corrections of virtual orbitals, known as multireference perturbation theory. Here, we exploit that the unperturbed Hamiltonian is diagonal for virtual orbitals and show that the number of qubits is independent of the number of virtual orbitals. This gives rise to more accurate energy estimates without increasing the number of qubits. Moreover, we demonstrate numerically for realistic chemical systems that the total runtime has highly favorable scaling in the number of virtual orbitals compared to previous work. Numerical calculations confirm the necessity of the multireference perturbation theory energy corrections to reach accurate ground state energy estimates. Our perturbation theory quantum algorithm can also be applied to symmetry-adapted perturbation theory. As such, we demonstrate that perturbation theory can help to reduce the quantum hardware requirements for quantum chemistry.

Messiah Sarfarazi, Qadir Rajabzadeh, Razieh Tavakoli et al.

In this work, a four-factor five-level full factorial central composite design (CCD) was used to optimize the ultrasound-assisted extraction (UAE) of saffron major components, namely picrocrocin, safranal and crocin. The process parameters included ethanol concentration (0–100%), extraction time (2–10 min), duty cycle (0.2–1.0) and ultrasonic amplitude (20–100%). The extracted compounds were measured both by spectrophotometry and chromatography techniques. The results revealed that the middle concentrations of ethanol and relatively long process durations along with high duty cycles and ultrasonic amplitudes had the most profound impact on the yields of the extracted bioactives. UAE was optimized using response surface methodology (RSM) and artificial bee colony (ABC); a comparison between these methods indicated their optimization power was approximately the same. According to the RSM analysis, an ethanol concentration of 58.58%, extraction time of 6.85 min, duty cycle of 0.82 and amplitude of 91.11% were the optimum extraction conditions, while the optimal conditions resulting from ABC were 53.07%, 7.32 min, 0.93 and 100% for the UAE variables respectively. Finally, HPLC analysis was carried out on the UAE optimum extract resulting from RSM. Four crocetin esters were detected in the optimal extract.

Thao Tranová, Jolanta Pyteraf, Mateusz Kurek et al.

Additive manufacturing technologies are considered as a potential way to support individualized pharmacotherapy due to the possibility of the production of small batches of customized tablets characterized by complex structures. We designed five different shapes and analyzed the effect of the surface/mass ratio, the influence of excipients, and storage conditions on the disintegration time of tablets printed using the fused deposition modeling method. As model pharmaceutical active ingredients (APIs), we used paracetamol and domperidone, characterized by different thermal properties, classified into the various Biopharmaceutical Classification System groups. We found that the high surface/mass ratio of the designed tablet shapes together with the addition of mannitol and controlled humidity storage conditions turned out to be crucial for fast tablet’s disintegration. As a result, mean disintegration time was reduced from 5 min 46 s to 2 min 22 s, and from 11 min 43 s to 2 min 25 s for paracetamol- and domperidone-loaded tablets, respectively, fulfilling the European Pharmacopeia requirement for orodispersible tablets (ODTs). The tablet’s immediate release characteristics were confirmed during the dissolution study: over 80% of APIs were released from printlets within 15 min. Thus, this study proved the possibility of using fused deposition modeling for the preparation of ODTs.