Hasil untuk "Organic chemistry"

Wen Zhang, R. Xiong

E. Herbst, E. Dishoeck

A. Loupy

C. Moreno-Castilla

M. Andreae, P. Crutzen

N. W. Ockwig, O. Delgado-Friedrichs, M. O'Keeffe et al.

R. Noyori

S. Mann

R. Grubbs, Sukbok Chang

C. Sanchez, F. Ribot

H. Schulten, M. Schnitzer

R. Atkinson

M. Raaijmakers, N. Benes

Juncong Jiang, Yingbo Zhao, O. Yaghi

Carlotta Breschi, Lorenzo Cecchi, Federico Mattagli et al.

Consumers are increasingly willing to pay a premium for high-quality extra virgin olive oils (HQ-EVOOs) with specific sensory or nutraceutical properties, and originating from particular botanical or geographical origins. Regarding geographic origin, Italy is one of the main producers, with many local production areas, each characterized by its own distinctive typicity. The aim of this study is the chemical, sensory, and nutraceutical profiling of HQ-EVOO produced over two production years in Montespertoli (province of Florence) by 12 producers involved in the “MontEspertOlio” project, funded by the Tuscan Region. Oils were produced based on a production process previously defined and specifically applied to this territory. The shelf-life of the oil was also evaluated over a 12-month period. Legal quality parameters were analyzed according to EU regulation. Phenolic compounds, tocopherols, fatty acid composition, and volatile compounds were analyzed using HPLC-DAD, HPLC-FLD, HS-SPME-GC-MS, and GC-FID, respectively. Finally, sensory analysis was conducted using the Panel Test method. Results showed that Montespertoli HQ-EVOO is characterized by distinctive sensory and chemical traits that fully match consumer preferences, even across two production years characterized by different growing conditions. The shelf-life performance was excellent over 12 months, also showing a protective effect of greater bottle sizes against oxidation.

Chetan Deshmukh, R S Shendge, Rutik J Jadhav

Context: Androgenic alopecia (AGA) is a common condition affecting both men and women, characterized by progressive hair loss due to genetic and hormonal factors. Hair loss has significant impacts on psychosocial well-being and quality of life. Evidence Acquisition: A comprehensive review of peer-reviewed studies was conducted, including clinical trials, observational studies, and emerging treatment reports published from 2000 to 2024. Databases such as PubMed, Scopus, and Web of Science were searched using keywords related to AGA, hair growth, and therapies. Results: Current treatments for AGA include topical agents like minoxidil and finasteride, oral medications, and advanced options such as hair transplantation. Emerging therapies, including platelet-rich plasma (PRP), low-level laser therapy (LLLT), JAK inhibitors, and gene therapy, show promising efficacy in promoting hair regrowth. Combination therapies often enhance clinical outcomes. Conclusions: While traditional treatments remain effective, emerging therapies and combination approaches offer improved results for AGA management. Ongoing research in gene therapy and novel molecular interventions may transform future therapeutic strategies.

Ulises Murrieta-Dionicio, Fernando Calzada, Elizabeth Barbosa et al.

Diseases caused by intestinal parasites such as protozoa represent a worldwide problem mainly for developing countries. From morbidity in different groups of people to cases of mortality in children and/or immunocompromised patients. In addition to the above, there is growing resistance to the drugs used in the treatment of these diseases, as well as undesirable side effects in patients. Therefore, there is an interest in the search for new alternatives for the base and/or development of new drugs with antiparasitic activities without harmful effects. In this sense, natural products offer to be a diverse source of compounds with biological activities. In this work, we describe the isolation and elucidation by 1D and 2D NMR spectroscopy of three cyclopeptides obtained from seeds of <i>A. diversifolia</i> Saff.: cherimolacyclopeptide D (<b>1</b>), squamin D (<b>2</b>), and squamin C (<b>3</b>). The fractions enriched in cyclopeptides, as well as a pure compound (<b>1</b>), showed antiprotozoal activity against <i>E. hystolitica</i> Schaudinn and <i>Giardia lamblia</i> Kunstler in vitro assays, with values of IC₅₀ = 3.49 and 5.39 μg mL⁻¹, respectively. The molecular docking study revealed that <b>1</b> has a strong interaction with targets used, including aldose reductase and PFOR enzymes. The antiprotozoal activity of cherimolacyclopeptide D is reported for the first time in this study.

Sean A. Locke, Dana M. Calhoun, José M. Valencia Cruz et al.

Members of the genus Scaphanocephalus mature in accipitrids, particularly osprey, Pandion haliaetus, with metacercaria causing Black Spot Syndrome in reef fishes. In most of the world, only the type species, Scaphanocephalus expansus (Creplin, 1842) has been reported. Recent molecular studies in the Western Atlantic, Mediterranean and Persian Gulf reveal multiple species of Scaphanocephalus, but have relied on 28S rDNA, mainly from metacercariae, which limits both morphological identification and resolution of closely related species. Here we combine nuclear rDNA with mitochondrial sequences from adult worms collected in osprey across North America and the Caribbean to describe species and elucidate life cycles in Scaphanocephalus. A new species described herein can be distinguished from S. expansus based on overall body shape and size. Phylogenetic analysis of the whole mitochondrial genome of Scaphanocephalus indicates a close relationship with Cryptocotyle. We conclude that at least 3 species of Scaphanocephalus are present in the Americas and 2 others are in the Old World. Specimens in the Americas have similar or identical 28S to those in the Mediterranean and Persian Gulf, but amphi-Atlantic species are unlikely in light of divergence in cytochrome c oxidase I and the lack of amphi-Atlantic avian and fish hosts. Our results provide insight into the geographic distribution and taxonomy of a little-studied trematode recently linked to an emerging pathology in ecologically important reef fishes.

Yaoyi He, Mingzhi Jiao

Carbon monoxide can cause severe harm to humans even at low concentrations. Metal Oxide Semiconductor (MOS) carbon monoxide gas sensors have excellent sensing performance regarding sensitivity, selectivity, response speed, and stability, making them very desirable candidates for carbon monoxide monitoring. However, MOS gas sensors generally work at temperatures higher than room temperature, and need a heating source that causes high power consumption. High power consumption is a great problem for long-term portable monitoring devices for point-of-care or wireless sensor nodes for IoT application. Room-temperature MOS carbon monoxide gas sensors can function well without a heater, making them rather suitable for IoT or portable applications. This review first introduces the primary working mechanism of MOS carbon monoxide sensors and then gives a detailed introduction to and analysis of room-temperature MOS carbon monoxide sensing materials, such as ZnO, SnO₂, and TiO₂. Lastly, several mechanisms for room-temperature carbon monoxide sensors based on MOSs are discussed. The review will be interesting to engineers and researchers working on MOS gas sensors.

Rina Yada, Tomoko Kawasaki-Takasuka, Takashi Yamazaki

The present article describes the successful performance of crossed aldol reactions of the CF₃-containing pseudo-C₂ symmetric cyclic imide with various aldehydes. The utilization of HMPA as an additive attained the preferential formation of the <i>anti</i>-products in good to excellent yields, which contrasts with our previous method without this additive, proceeding to furnish the corresponding <i>syn</i>-isomers. The effective participation of ketones and α,β-unsaturated carbonyl compounds in reactions with this imide was also demonstrated to expand the application of this imide.