Hasil untuk "Organic chemistry"

Haeshin Lee, Shara M. Dellatore, W. Miller et al.

T. Lowry, K. Richardson

R. Hoffmann

David F. Eaton

P. Hodge

John D. Roberts

R. Atkinson

O. Yaghi, C. Diercks, Markus J. Kalmutzki

Reticular chemistry has been applied to synthesize new classes of porous materials that are successfully used for myraid applications in areas such as gas separation, catalysis, energy, and electronics. Introduction to Reticular Chemistry gives an unique overview of the principles of the chemistry behind metal-organic frameworks (MOFs), covalent organic frameworks (COFs), and zeolitic imidazolate frameworks (ZIFs). Written by one of the pioneers in the field, this book covers all important aspects of reticular chemistry, including design and synthesis, properties and characterization, as well as current and future applications

F. F. de Araújo, David de Paulo Farias, I. A. Neri-Numa et al.

Polyphenols are compounds naturally present in fruits and vegetables that are gaining more and more attention due to their therapeutic effects and their potential technological applications. In this review, we intend to demonstrate the importance of some phenolic compounds, addressing their biological effects and potential for applications in various industrial fields. The intake of these compounds in appropriate concentrations can present promising effects in the prevention of diseases such as diabetes, obesity, Parkinson's, Alzheimer's, and others. They can also be used to improve the physicochemical properties of starch, in the preservation of foods, as natural dyes, prebiotic ingredients, hydrogels and nanocomplexes. In addition, these compounds have potential for innovation in the most diverse technological fields, including organic fine chemistry, basic materials chemistry, pharmaceuticals, food chemistry, chemical engineering, etc.

D. Basavaiah, B. S. Reddy, S. Badsara

C. Reichardt, T. Welton

M. Semeñiuk, Z. Yi, V. Poursorkhabi et al.

Over the span of the past decade, carbon dots (CDs) synthesized from renewable organic resources (organic CDs) have gathered a considerable amount of attention for their photoluminescent properties. This review will focus on organic CDs synthesized using clean chemistry and conventional synthetic chemistry from organic sources and their fluorescence mechanisms, such as quantum confinement effect and surface/edge defects, before outlining their performance in electronic applications, including organic photovoltaic devices, organic light-emitting devices, biosensors, supercapacitors, and batteries. The various organic resources and methods of organic CDs synthesis are briefly covered. Many challenges remain before the adoption of CDs can become widespread; their characterization, structure, functionality, and exact photoluminescent mechanism all require additional research. This review aims to summarize the current research outcomes and highlight the area where further research is needed to fully use these materials.

J. Stöckigt, A. Antonchick, Fangrui Wu et al.

S. Stupp, Liam C. Palmer

L. Domingo, P. Pérez

Yun Zhang, Yiwen Guo, Kaibo Sun et al.

Zn-doped carbon dots (Zn@C-210 calcination temperature at 210 °C and Zn@C-260 calcination temperature at 260 °C) were synthesized via an in situ calcination method using zinc citrate complexes as precursors, aiming to investigate the mechanisms of their distinctive fluorescence properties. A range of analytical methods were employed to characterize these nanomaterials. The mechanism study revealed that the coordination structure of Zn-O, formed through zinc doping, can induce a metal–ligand charge-transfer effect, which significantly increases the probability of radiative transitions between the excited and ground states, thereby enhancing the fluorescence intensity. The Zn@C-210 in a solid state and Zn@C-260 in water exhibited approximately 71.50% and 21.1% quantum yields, respectively. Both Zn@C-210 and Zn@C-260 exhibited excitation-independent luminescence, featuring a long fluorescence lifetime of 6.5 μs for Zn@C-210 and 6.2 μs for Zn@C-260. Impressively, zinc-doped CDs displayed exceptional biosafety, showing no acute toxicity even at 1000 mg/kg doses. Zn@C-210 has excellent fluorescence in a solid state, showing promise in anti-photobleaching applications; meanwhile, the dual functionality of Zn@C-260 makes it useful as a folate sensor and cellular imaging probe. These findings not only advance the fundamental understanding of metal-doped carbon dot photophysics but also provide practical guidelines for developing targeted biomedical nanomaterials through rational surface engineering and doping strategies.

Mustafa Sevindik, Ayşenur Gürgen, Aras Fahrettin Korkmaz et al.

In this study, extraction conditions were optimized to maximize the biological activities of extracts obtained from <i>Paralepista flaccida</i>, an edible mushroom species. Extraction processes were carried out using an ultrasonically assisted system, and two different optimization approaches were used as follows: Response Surface Methodology (RSM) and Artificial Neural Network–Genetic Algorithm (ANN-GA). The antioxidant potentials of the optimized extracts were evaluated using DPPH, FRAP, TAS, TOS, and OSI parameters; anticholinesterase activities were measured against AChE and BChE enzymes; and antiproliferative activities were investigated in A549, MCF-7, and DU-145 human cancer cell lines. In addition, phenolic contents were determined by LC-MS/MS analysis. The findings revealed that the extracts obtained by the RSM method exhibited a superior biological profile compared to ANN-GA extracts in terms of antioxidant, anticholinesterase, and antiproliferative activities. The high cytotoxicity observed, particularly in the MCF-7 line, supports the anticancer potential of this extract. These results demonstrate that optimization strategies are crucial for increasing not only extract yield but also biological functionality.

Zihao Deng, Lixia Liu, Guantai Xie et al.

Excessive lipid accumulation promotes the occurrence and progression of hepatocellular carcinoma (HCC), accompanied by high levels of fatty acid synthetase (FASN) and more active lipogenesis. Heat shock protein 90 (Hsp90) acts as a chaperone to maintain the stability and activity of the client proteins. Studies have revealed that Hsp90 regulates the lipid metabolism of HCC, but the effect of Hsp90 on FASN still remains unknown. This study aims to discover the mechanism of Hsp90 inhibition on lipid accumulation and investigate the different effects of Hsp90 N-terminal domain inhibitor STA9090 and C-terminal domain inhibitor novobiocin on FASN protein stability and transcription pathway in HCC. We found that HCC cells tended to store lipids, which could be disrupted by Hsp90 inhibitors in vivo and in vitro. High levels of Hsp90α and FASN in tumor tissue had correlation with poor prognosis of HCC patients, and Hsp90α interacted with FASN to maintain its protein stability. Furthermore, N-terminal domain of Hsp90α was essential for process of sterol regulatory element binding protein 1 to activate FASN transcription and Hsp90α prevented proteasomal degradation of liver X receptor α to upregulate FASN transcription via liver X receptor α/sterol regulatory element binding protein 1 axis. Our data reveal that Hsp90α promotes lipid accumulation by increasing the protein stability and FASN mRNA transcription, and can be alleviated by Hsp90 inhibitors, which provides a theoretical basis for Hsp90-targeted therapy on lipid metabolism in HCC.

Mehvish Aqil, Malik Istikhar Ali Sajjad , Mehr Muhammad Imran et al.

Background: Nontuberculous mycobacteria (NTM), a diverse group of environmental organisms rapidly proliferating in water, soil, and dust, are becoming a common cause of clinical disease. This study analyzed patient data from two major hospitals in Faisalabad, Pakistan, to improve early detection of NTM lung disease and to guide clinical practice in seeking earlier and quicker intervention.   Methods: A retrospective cross-sectional study was conducted from January 2020 to December 2021, using the records of 294 tuberculosis patients at Allied Hospital and DHQ Hospital, Faisalabad. Non-probability convenience sampling was used for sample collection and sample size was collected using OpenEpi 3.0.0.  Data from patients with NTM lung disease were checked. The diagnosis was based on criteria defined by the ATS/IDSA (a clinical, radiological and microbiological evidence). Testing of specimens (sputum, BAL fluid, puncture fluid) was conducted using AFB smear, culture (MGIT 960) and species identification by molecular techniques. Chi-square, Wilcoxon tests and logistic regression were performed using SPSS version 26.0.p<0.05 was considered as significant. Results: There were 294 patients (147 males; 147 females); median age 61 years, 77.2% had bronchiectasis. The most frequently identified species was the Mycobacterium avium-intracellulare complex (MAC 56.1%) followed by M. kansasii (19%) and M. abscessus (15.3%).   Sputum cultures had the highest positivity rate (87.4%), outperforming BAL fluid (80.3%) and puncture fluid (61.5%). Conclusion: The M. avium-intracellulare complex is the most common NTM species found in patients in these hospitals. The signs of expectoration, gender and bronchiectasis increased likelihood of BAL culture positivity, which aids in diagnosis.

Consuelo Celesti, Daniela Iannazzo, Elpida Piperopoulos et al.