Hasil untuk "Analytical chemistry"

B. D. de Marco, Bárbara Saú Rechelo, E. G. Tótoli et al.

The growing process of industrialization was a milestone for world economic evolution. Since the 1940s, social movements have revolutionized green chemistry and provided shifts in industrial positions and sustainable processes with advances in environmental impact and awareness of companies and population. Paul Anastas and John Warner, in the 1990s, postulated the 12 principles of Green Chemistry, which are based on the minimization or non-use of toxic solvents in chemical processes and analyzes, as well as, the non-generation of residues from these processes. One of the most active areas of Research and Development in Green Chemistry is the development of analytical methodologies, giving rise to the so-called Green Analytical Chemistry. The impacts of green chemistry on pharmaceutical analyzes, environmental, population, analyst and company are described in this review and they are multidimensional. Every choice and analytical attitude has consequences both in the final product and in everything that surrounds it. The future of green chemistry as well as our future and the environment is also contemplated in this work.

Abigail Rose Walker, Berkay Selçuk, Ismail Erol et al.

Summary: G protein-coupled receptors (GPCRs) are major drug targets and key regulators of cell signaling. The basis of functional diversification between individual GPCRs and families of GPCRs can be revealed by investigating evolutionary conservation patterns. In this study, we investigated the functional role of specifically conserved residues in the TM1/TM7/H8 dimerization interface of beta-adrenergic receptors (BARs). Residues specifically conserved for B2AR compared to B1AR and B3AR subtypes were identified via phylogenetic analysis. The significance of residues differentially conserved between receptor subtypes at the TM1/TM1 interface was investigated using molecular dynamics (MD) simulations in combination with biophysical and functional studies. Our findings suggest that differentially conserved residues within TM1 of BARs modulate receptor conformation without disrupting dimerization to impact cell surface expression, basal activity, and endocytosis. This highlights the importance of TM1 in modulating receptor function and provides new insights into the evolutionary and functional differences among beta-adrenergic receptor subtypes.

Ivanova Ivelina, Petrova Ivalina, Gandova Vanya

Corn oil is widely used in foods, especially for a variety of diets. This work presents the determination of some physicochemical parameters of the oil: density, surface tension, surface energy, and surface heat capacity. The change in physicochemical and surface parameters is presented at five temperatures (25, 40, 60, 80, and 100°C). With the increase of temperature, all parameters decreased – density (from 0.924 to 0.899 g cm-3), surface tension (from 34.31 to 28.37 mN m-1), surface energy (from 143.74 to 142.70 mPa s), and surface heat capacity (from 8890.83 to 11127.34 N m-1K-1). The present results are the basis for future studies on the inclusion of corn oil in food products with improved functional characteristics.

Faezeh Shaban, Shaghyegh Ghadimi, Afra Alipour et al.

Orthodontic-related root resorption affects dental health. The aim of the present study was to review the research conducted on the risk factors associated with orthodontic-related root resorption and its treatment methods. This is a review on scientific databases PubMed, Google Scholar, and Web of Science. Available data were extracted from the studies, and they were reviewed for quality and methodology. Between 2021 and 2024, 16,531 records were identified. Based on the search keywords, 398 studies were remined from screened records, and finally, 24 records were included. Factors such as the intensity and duration of orthodontic forces, tooth root characteristics (including root length and shape), age, history of dental trauma, and genetics may increase the risk of root resorption.

Prerna Sharma, Kavita Verma, Saurabh Goel et al.

Background: Benign vascular lesions called hemangiomas are frequently found in the head and neck area. Objective: To calculate the oral cavity hemangioma prevalence in the people of Udaipur. Materials and Methods: Every individual who reported to the Outpatient Department (OPD) underwent screening for a year in the cross-sectional study. The diagnostic criteria for identifying Arterioveous (AV) or Oral hemangiomas (OH) anomalies were used to assess clinical findings. The history, clinical examination, diascopy test, and panoramic radiographs were used to make the diagnosis of OH. Results: Among the population screened, the prevalence of oral cavity hemangiomas has been reported to be 2.6%. At an average age of 54.62 years, the number of males and females was recorded to be 12 (66.6%) and 6 (33.3%), respectively. Conclusion: More research ought to be done in the future to ascertain its clinical correlation with age, gender, and the location of incidence due to least number of studies available.

Mu-ying-nan YOU, Xin-yu LIU, Xian-zhe SHI et al.

Cells are the most basic structural and functional unit of living organisms. In recent years, people have paid more attention to cell heterogeneity. In order to characterize the heterogeneity of cells and prevent the life information in an individual cell from being overwhelmed by the average level of the population gained from traditional cell biology research, many new analytical techniques have been developed for single-cell analysis. However, single-cell analysis is extremely challenging due to the minimal cell volume, low content and wide variety of analytes in single cells, some of analytes change rapidly in cells and others may interfere with each other during analysis. Mass spectrometry has gradually become an ideal tool for single-cell analysis due to its high sensitivity, high resolution and high selectivity. In this review, several techniques of single-cell analysis based on mass spectrometry in the recent five years were systematically summarized and discussed including electrospray ionization mass spectrometry (ESI-MS), laser desorption ionization mass spectrometry (LDI-MS), secondary ion mass spectrometry (SIMS) and inductively coupled plasma mass spectrometry (ICP-MS). Finally, this review also looked into future developments of these mass spectrometry-based techniques. With the development of cell biology, the requirement for single-cell analysis technology is increasing as well. In the meanwhile, single-cell analysis, which focuses on studying the mechanisms of cellular and molecular behavior, has aroused more and more attention from various branches of life sciences in recent years. Although higher spatial resolution and detection sensitivity have become the development trends for single-cell mass spectrometry, none of these mass spectrometry-based techniques can be recognized flawless, which means they all have certain flaws to some extent. Consequently, single-cell analysis technology based on mass spectrometry is developing towards methodological diversification. On the one hand, it is of great importance to choose one suitable mass spectrometry-based technique according to the research purpose and actual conditions. On the other hand, it should be also emphasized that different methods can complement each other and jointly provide a more comprehensive analysis environment for single-cell mass spectrometry, thereby improving and innovating existing single-cell analysis techniques based on mass spectrometry. This review will provide insights into better understanding on and development of single-cell analysis by mass spectrometry.

Khyati V Patel, Ajay Kubavat, Nikunj Prajapati et al.

Aim: The current study's objective was to find out the prevalence of malocclusion and the need for orthodontic treatment in 13- to 15-year-old school students in the Mehsana District of Gujarat using the IOTN. Materials and Methods: A descriptive cross-sectional epidemiological survey was planned among 13- to 15-year-old school-going children of Mehsana district. The sample comprised of 1290 school children. DHC-IOTN was applied to evaluate normative need for orthodontic treatment. Perceived orthodontic treatment was described by the Aesthetic component of the IOTN index. Results: Results showed that 33.7 percent of participants required little/no treatment need, 43.9 percent of participants required moderate orthodontic treatment need, and 22.4 percent of participants required severe orthodontic treatment need in the district. Conclusion: To prepare for public orthodontic and dental services, the current study provides baseline data on the need for orthodontic treatment among school-aged children.

R. Brereton

M. Rutkowska, J. Płotka-Wasylka, Calum Morrison et al.

Rania Elkeeb, Anomeh Avartoomian, Amira S. Gouda et al.

The aim of the study is to evaluate the effectiveness of the pediatric sofosbuvir weight-based dosing strategy in providing an equitable drug exposure compared to the marketed dose. The physiologically based pharmacokinetic (PBPK) modeling and simulation is a valuable tool in assessing drug dosing and toxicity in populations with physiological, pathological, and genetic pharmacokinetic (PK) variability. The PBPK model of the sofosbuvir compound was developed using Simcyp^® V20. The model was developed and verified using the published sofosbuvir’s physicochemical properties and clinical data from multiple studies on healthy adult volunteers, hepatitis C virus (HCV)-infected adults, and HCV-infected pediatrics. The AUC and C_max fold ratio of (predicted/observed) fell within the acceptable range of 0.5–2 in all tested adults’ data, confirming the successful development of the sofosbuvir Simcyp^® compound model. Using this model, a weight-based dosing regimen of 6 mg/kg in pediatric patients was simulated and compared to the 150 mg and 200 mg approved dose for 3–6 and 6–12 y/o pediatric patients, respectively. No dose adjustment was recommended in patients ages 6–12 y/o. However, compared to the approved 150 mg for 3–6 y/o, the weight base dose provided an equitable drug exposure to adults. Further clinical studies are warranted to verify this finding.

Čižmáriková R., Habala L., Valentová J. et al.

The present work describes the synthesis, physico-chemical characteristics, antioxidative properties, and high-performance liquid chromatography (HPLC) enantioseparation of novel, potentially bioactive aryloxyaminopropanols – derivatives of naphthalen-2-ol modified in the basic part of their molecules. Reaction of naphthalene-2-ol with chloromethyloxirane leads to 2-[(naphthalen-2-yloxy)methyl]oxirane, which reacts in the next step with branched aliphatic amines (isopropylamine, tert-butylamine, and dimethylamine), aromatic amines (aniline, 3,4-dimethoxyphenylethylamine), and heterocyclic amines (pyrrolidine, imidazole, 2-methylimidazole, piperidine, morpholine, 4-methylpiperidine, or 2-methoxyphenylpiperidine). The target compounds were isolated in the form of free bases, as well as their salts with fumaric or hydrochloric acid. Their purity was established by thin-layer chromatography and their IR, UV, 1H-NMR, and 13C-NMR spectra were recorded. The antioxidant activities of prepared compounds were measured by the 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid (ABTS) method and they were compared with the values for the corresponding salts. Enantioseparation was accomplished by means of enantioselective HPLC using amylose tris(3,5-dimethylphenyl)carbamate (Chiralpak AD), as well as Chirobiotic T (native teicoplanin) in some cases.

Yorfan Ruwindya

Perbandingan metode penentuan sitronelal dalam minyak sereh ini dilakukan untuk mengetahui perbandingan metode kromatografi gas detektor FID dengan kromatografi gas detektor MS. Kandungan sitronelal dalam sampel minyak sereh wangi yang diperoleh dengan detektor FID serta detektor MS masing-masing sebesar 49,34% dan 42,97%. Metode kromatografi gas detektor FID dan detektor MS memiliki nilai presisi yang baik dengan nilai %RSD kurang dari 2% yaitu sebesar 0,295% dan 1,114%. Hasil uji t diperoleh nilai t hitung > t tabel yang artinya Ho ditolak dan Hi diterima. Hasil uji t menunjukkan bahwa kedua metode memberikan hasil yang berbeda secara signifikan terhadap kandungan sitronelal dalam minyak sereh wangi tetapi masih dapat diterapkan pada laboratorium.

Marwa M. Saeed, Álvaro Fernández-Ochoa, Fatema R. Saber et al.

The aim of the present study is to investigate the phytochemical composition of tiger nut (TN) (<i>Cyperus esculentus</i> L.) and its neuroprotective potential in scopolamine (Scop)-induced cognitive impairment in rats. The UHPLC-ESI-QTOF-MS analysis enabled the putative annotation of 88 metabolites, such as saccharides, amino acids, organic acids, fatty acids, phenolic compounds and flavonoids. Treatment with TN extract restored Scop-induced learning and memory impairments. In parallel, TN extract succeeded in lowering amyloid beta, β-secretase protein expression and acetylcholine esterase (AChE) activity in the hippocampus of rats. TN extract decreased malondialdehyde levels, restored antioxidant levels and reduced proinflammatory cytokines as well as the Bax/Bcl2 ratio. Histopathological analysis demonstrated marked neuroprotection in TN-treated groups. In conclusion, the present study reveals that TN extract attenuates Scop-induced memory impairments by diminishing amyloid beta aggregates, as well as its anti-inflammatory, antioxidant, anti-apoptotic and anti-AChE activities.

Ijirana Ijirana, Sitti Aminah, Supriadi Supriadi et al.

Critical thinking skills has to be sharpened particularly during the COVID19 pandemic. This circumstance leads to the lack of students passion to apply their thinking skills in doing something necessary. Therefore, it requires a learning improving critical thinking skills. This study aims to describe the critical thinking skills of chemistry education students taking part in the lecture of Team Project Based STEM-metacognitive skills. The method utilized is a Pre-Experimental Design One-Shot Case Study consists of 130 chemistry education students taking part in 3rd and 5th semester. The 3rd semester students attend lectures on the development of chemistry learning programs (P3K) and the 5th semester students attend lectures on the basics of analytical chemistry (DDKA). The instruments utilized in this research are learning scenarios, worksheets, critical thinking test instruments, critical thinking skill assessment rubrics, and project implementation feasibility observation sheets. There are three critical thinking skills very well demonstrated by students in P3K and DDKA subjects, consist of (1) strategies and tactics, (2) providing simple explanations, and (3) providing further explanations. Two other skills, namely concluding and building basic skills shown by students in the good category. The results of this study contribute to chemistry learning in the future, thus efforts are inevitably required to train critical thinking skills for prospective chemistry teachers in order to produce teachers having good thinking skills.

Vincent Debrauwer, Ivo Leito, Märt Lõkov et al.

Mounir Tilaoui, Hanane Achibat, Marius Lébri et al.

In recent decades, extensive research has been focused on the screening and investigating the antioxidant and anticancer activities of medicinal plants extracts or isolated natural product-based drugs. Therefore, the present study aimed to evaluate the phytochemical, antioxidant and in vitro anticancer activities of Bombax buonopozense extracts. Standard methods were used for the identification of alkaloids, tannins, flavonoids, coumarins, saponins, sterol, triterpenes and reducing compounds. Free-radical–scavenging activity was measured by the 2,2’-diphenyl-1-picrylhydrazyl (DPPH) free radical assay, and the cytotoxic potential was evaluated in the P815 murin lymphoblast-like mastocytoma cell line using the MTT assay. Regarding the antioxidant activity, our results showed a powerful in vitro free-radical scavenging activity of the ethanolic extract compared to the aqueous extracts, with IC50 values of 10 and 220 µg/mL, respectively. In the MTT assay, the ethanolic extract showed a moderate and dose-dependent association growth inhibition of P815 cells in a dose above of 200 µg/mL with IC50 of 74 µg/mL compared to cisplatin (IC50= 4 µg/mL). Our findings demonstrate that Bombax buonopozense ethanolic extract could be an effective antioxidant and promising antiproliferative agent.

Izaz Shaik, Malti Tulli, Priyanka Unnam et al.

This meta-analysis is intended to evaluate the reliability of evidences published in current regenerative endodontic publications in a critical way. This meta-analysis is used to summarize and analyze the various clinical and radiographic findings associated with nonvital immature permanent teeth which have been treated with regenerative endodontic techniques. We also intend to significantly evaluate the worth of facts provided in the previous published literature. A structured electronic search by authors was undertaken in August 2020 using MEDLINE and PubMed search engine. The chosen parameters studied in this systematic review were presented in flowcharts and were summarized. We observed a good accomplishment rates in terms of survival of the treated tooth and also in resolution of any associated pathology in the apical areas; on contrary, our results in relation to apex closure along with constant root development, our findings from various studies were quiet variable. Regenerative endodontic procedures are constantly being restructured and enhanced to benefit present-day dentistry in all likely ways. Still, many factors that are important for the success of regenerative endodontic treatment outcomes still remain unexplained. There are still numerous gaps in our expertise at the present stage of this study.

E. Ziegel

F. Settle

Andreea Creteanu, Daniela Pamfil, Cornelia Vasile et al.

The aim of this study was to improve the solubility of amiodarone hydrochloride (AMD) and the drug release using its inclusion complexes with 2-hydroxypropyl-β-cyclodextrin (HP-β-CD). The inclusion complexes were prepared by coprecipitation and freeze-drying. The solubility enhancement of AMD/HP-β-CD inclusion complexes by 4–22 times was evaluated by the phase solubility method. The inclusion complexes were studied both in solution and in solid state by spectroscopic methods, dynamic light scattering (DLS) and zeta potential analysis, SEM, and DSC. The formulations of AMD/HP-β-CD inclusion complexes both as powdered form and as matrix tablets showed superior pharmacokinetic performance in improving loading and release properties in respect of those of the insoluble AMD drug. In vitro kinetic study reveals a complex mechanism of release occurring in three steps: the first one being attributed to a burst effect and the other two to different bonding existing in inclusion complexes. An in vivo test on matrix tablets containing Kollidon® and chitosan also reveals a multiple (at least two) peaks release diagram because of both structures of the inclusion complexes and also of different sites of absorption in biological media (digestive tract).