3,595 research outputs found

    Dietary Anti-Aging Polyphenols and Potential Mechanisms

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    For years, the consumption of a diet rich in fruits and vegetables has been considered healthy, increasing longevity, and decreasing morbidities. With the assistance of basic research investigating the potential mechanisms, it has become clear that the beneficial effects of plant-based foods are mainly due to the large amount of bioactive phenolic compounds contained. Indeed, substantial dietary intervention studies in humans have supported that the supplementation of polyphenols have various health-promoting effects, especially in the elderly population. In vitro examinations on the anti-aging mechanisms of polyphenols have been widely performed, using different types of natural and synthetic phenolic compounds. The aim of this review is to critically evaluate the experimental evidence demonstrating the beneficial effects of polyphenols on aging-related diseases. We highlight the potential anti-aging mechanisms of polyphenols, including antioxidant signaling, preventing cellular senescence, targeting microRNA, influencing NO bioavailability, and promoting mitochondrial function. While the trends on utilizing polyphenols in preventing aging-related disorders are getting growing attention, we suggest the exploration of the beneficial effects of the combination of multiple polyphenols or polyphenol-rich foods, as this would be more physiologically relevant to daily lif

    Discriminating different scenarios to account for the cosmic e±e^\pm excess by synchrotron and inverse Compton radiation

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    The excesses of the cosmic positron fraction recently measured by PAMELA and the electron spectra by ATIC, PPB-BETS, Fermi and H.E.S.S. indicate the existence of primary electron and positron sources. The possible explanations include dark matter annihilation, decay, and astrophysical origin, like pulsars. In this work we show that these three scenarios can all explain the experimental results of the cosmic e±e^\pm excess. However, it may be difficult to discriminate these different scenarios by the local measurements of electrons and positrons. We propose possible discriminations among these scenarios through the synchrotron and inverse Compton radiation of the primary electrons/positrons from the region close to the Galactic center. Taking typical configurations, we find the three scenarios predict quite different spectra and skymaps of the synchrotron and inverse Compton radiation, though there are relatively large uncertainties. The most prominent differences come from the energy band 104∼10910^4\sim 10^9 MHz for synchrotron emission and ≳10\gtrsim 10 GeV for inverse Compton emission. It might be able to discriminate at least the annihilating dark matter scenario from the other two given the high precision synchrotron and diffuse γ\gamma-ray skymaps in the future.Comment: published in Pr

    Novel Brønsted-acidic ionic liquids based on benzothiazolium cations as catalysts for esterification reactions

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    Three novel Brønsted-acidic ionic liquids based on benzothiazolium cations were prepared, which served as catalysts for the synthesis of benzoic esters. All three gave good yields of the target esters in esterification reactions. Moreover, they combine the advantages of both homogeneous and heterogeneous solid catalysts in esterification reactions, which enabled them to serve as homogeneous catalysts to catalyze the reactions and be conveniently recovered by simple filtration after the reactions. They could be reused several times without noticeable decrease in efficiency

    Systematic review and meta-analysis of Chinese herbal formula Tongxie Yaofang for diarrhea-predominant irritable bowel syndrome: Evidence for clinical practice and future trials

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    Introduction: Diarrhea-predominant irritable bowel syndrome (IBS-D) significantly decreases the quality of life of patients and their families, and affects patients’ mental health. No specific western medications are available. Ancient classical Chinese medical texts have recognized Tongxie Yaofang (TXYF) as a therapy for diarrhea which is widely used in clinical practice. Standard TXYF prescription (S-TXYF) is composed of four herbal medicines: Atractylodes macrocephala Koidz. [Asteraceae; Rhizoma Atractylodis Macrocephalae.], Paeonia lactiflora Pall. [Ranunculaceae; Paeoniae Radix Alba], Citrus × aurantium L. [Rutaceae; Citri Reticulatae Pericarpium] and Saposhnikovia divaricata (Turcz. ex Ledeb.) Schischk. [Umbelliferae; Saposhnikoviae Radix]. This review aimed to evaluate the therapeutic effects and safety of S-TXYF for IBS-D. Methods: Eight English and Chinese electronic databases were searched from their inception to 25 December 2021 for randomized controlled trials (RCTs) comparing S-TXYF with placebo, western medications or no treatment for IBS-D. The primary outcome was the global improvement of IBS-D symptoms. Data were analyzed using Cochrane’s Revman 5.4 software. Evidence certainty was assessed using the online GRADEpro tool for the primary outcome. Results: Eleven RCTs involving 985 adults with IBS-D were included. For global improvement of symptoms, S-TXYF was superior to western medication and placebo (moderate evidence by GRADE). Regarding the improvement of stool consistency, stool frequency and abdominal pain, S-TXYF was significantly effective than placebo. In addition, S-TXYF was superior to western medication on improving the quality of life and relieving anxiety. Six trials reported adverse events: five of them reported (non-serious) adverse events occurred in both groups, and one trial reported that 3 cases with adverse events (constipation, elevation in liver-enzyme, nausea) occurred in S-TXYF group and 3 cases with adverse events (abdominal distension, nausea) occurred in placebo group. Conclusion: Although current results showed that S-TXYF may have potential to treat IBS-D and its use appears to be safe, no a clear and confirmed conclusion can be drawn from our review as the overall inadequate design of the included trials reviewed. So more rigorous trials are warranted to establish confirmed evidence on its benefits and safety
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