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351.
352.
An overview of the different covalent bonding synthetic strategies of two electron acceptors leading to fullerene-perylenediimide (C60-PDI)-based systems, essentially dyads and triads, is presented, as well as their more important applications. To go further in the development of such electron and photoactive assemblies, an original aromatic platform 5-benzyloxy-3-formylbenzoic acid was synthesized to graft both the PDI dye and the fullerene C60. This new C60-PDI dyad exhibits a free anchoring phenolic function that could be used to attach a third electro- and photoactive unit to study cascade electron and/or energy transfer processes or to obtain unprecedented side-chain polymers in which the C60-PDI dyads are attached as pendant moieties onto the main polymer chain. This C60-PDI dyad was fully characterized, and cyclic voltammetry showed the concomitant reduction process onto both C60 and PDI moieties at identical potential. A quasi-quantitative quenching of fluorescence was demonstrated in this C60-PDI dyad, and an intramolecular energy transfer was suggested between these two units. After deprotection of the benzyloxy group, the free hydroxyl functional group of the platform was used as an anchor to reach a new side-chain methyl methacrylate-based polymer in which the PDI-C60 dyad units are located as pendants of the main polymer chain. Such polymer which associates two complementary acceptors could find interesting applications in optoelectronics and in particular in organic solar cells. 相似文献
353.
Carina Hey Pui Cheung Dr. Tin Hang Chong Dr. Tongyao Wei Dr. Han Liu Prof. Dr. Xuechen Li 《Angewandte Chemie (International ed. in English)》2023,62(10):e202217150
Recently, ortho-phthalaldehyde (OPA) is experiencing a renascence for the modification of proteins and peptides through OPA-amine two-component reactions for bioconjugation and intramolecular OPA-amine-thiol three-component reactions for cyclization. Historically, small thiol molecules were used in large excess to allow for the intermolecular OPA-amine-thiol reaction forming 1-thio-isoindole derivatives. In this study, we discovered that guanidine could serve as an effective additive to switch the intermolecular OPA-amine-thiol three-component reaction to a stoichiometric process and enable the modular construction of peptide-peptide, and peptide-drug conjugate structures. Thus, 12 model peptide-peptide conjugates have been synthesized from unprotected peptides featuring all proteinogenic residues. Besides, 6 peptide-drug conjugates have been prepared in one step, with excellent conversions and isolated yields. In addition, a conjugate product has been further functionalized by utilizing a premodified OPA derivative, demonstrating the versatility and flexibility of this reaction. 相似文献
354.
Chung Pui Ping Muhammad Nadeem Akhtar Daud Ahmad Israf Enoch Kumar Perimal Mohd Roslan Sulaiman 《Molecules (Basel, Switzerland)》2020,25(22)
The perception of pain caused by inflammation serves as a warning sign to avoid further injury. The generation and transmission of pain impulses involves various pathways and receptors. Cardamonin isolated from Boesenbergia rotunda (L.) Mansf. has been reported to exert antinociceptive effects in thermal and mechanical pain models; however, the precise mechanism has yet to be examined. The present study investigated the possible mechanisms involved in the antinociceptive activity of cardamonin on protein kinase C, N-methyl-d-aspartate (NMDA) and non-NMDA glutamate receptors, l-arginine/cyclic guanosine monophosphate (cGMP) mechanism, as well as the ATP-sensitive potassium (K+) channel. Cardamonin was administered to the animals intra-peritoneally. Present findings showed that cardamonin significantly inhibited pain elicited by intraplantar injection of phorbol 12-myristate 13-acetate (PMA, a protein kinase C activator) with calculated mean ED50 of 2.0 mg/kg (0.9–4.5 mg/kg). The study presented that pre-treatment with MK-801 (NMDA receptor antagonist) and NBQX (non-NMDA receptor antagonist) significantly modulates the antinociceptive activity of cardamonin at 3 mg/kg when tested with glutamate-induced paw licking test. Pre-treatment with l-arginine (a nitric oxide precursor), ODQ (selective inhibitor of soluble guanylyl cyclase) and glibenclamide (ATP-sensitive K+ channel inhibitor) significantly enhanced the antinociception produced by cardamonin. In conclusion, the present findings showed that the antinociceptive activity of cardamonin might involve the modulation of PKC activity, NMDA and non-NMDA glutamate receptors, l-arginine/nitric oxide/cGMP pathway and ATP-sensitive K+ channel. 相似文献
355.
Georgiana Ioana Potra Cical&#x;u Petru Aurel Babes Horia Calniceanu Adelina Popa Gabriela Ciavoi Gilda Mihaela Iova Mariana Ganea Ioana Scrobot&#x; 《Molecules (Basel, Switzerland)》2021,26(22)
Periodontal disease and diabetes mellitus are two pathologies that are extremely widespread worldwide and share the feature of chronic inflammation. Carvacrol is a phenolic monoterpenoid, produced by a variety of herbs, the most well-known of which is Origanum vulgare. Magnolol is a traditional polyphenolic compound isolated from the stem bark of Magnolia officinalis, mainly used in Chinese medicine. The purpose of this paper is to review the therapeutic properties of these bioactive compounds, in the treatment of periodontitis and diabetes. Based on our search strategy we conducted a literature search in the PubMed and Google Scholar databases to identify studies. A total of one hundred eighty-four papers were included in the current review. The results show that carvacrol and magnolol have anti-inflammatory, antioxidant, antimicrobial, anti-osteoclastic, and anti-diabetic properties that benefit both pathologies. Knowledge of the multiple activities of carvacrol and magnolol can assist with the development of new treatment strategies, and the design of clinical animal and human trials will maximize the potential benefits of these extracts in subjects suffering from periodontitis or diabetes. 相似文献
356.
Pui Kei Mou Eun Ju Yang Changxiang Shi Guowen Ren Shishi Tao Joong Sup Shim 《Experimental & molecular medicine》2021,53(5):835
Recent advances in high-throughput sequencing technologies and data science have facilitated the development of precision medicine to treat cancer patients. Synthetic lethality is one of the core methodologies employed in precision cancer medicine. Synthetic lethality describes the phenomenon of the interplay between two genes in which deficiency of a single gene does not abolish cell viability but combined deficiency of two genes leads to cell death. In cancer treatment, synthetic lethality is leveraged to exploit the dependency of cancer cells on a pathway that is essential for cell survival when a tumor suppressor is mutated. This approach enables pharmacological targeting of mutant tumor suppressors that are theoretically undruggable. Successful clinical introduction of BRCA-PARP synthetic lethality in cancer treatment led to additional discoveries of novel synthetic lethal partners of other tumor suppressors, including p53, PTEN, and RB1, using high-throughput screening. Recent work has highlighted aurora kinase A (AURKA) as a synthetic lethal partner of multiple tumor suppressors. AURKA is a serine/threonine kinase involved in a number of central biological processes, such as the G2/M transition, mitotic spindle assembly, and DNA replication. This review introduces synthetic lethal interactions between AURKA and its tumor suppressor partners and discusses the potential of AURKA inhibitors in precision cancer medicine.Subject terms: Targeted therapies, Drug discovery 相似文献
357.
Farbod Shafiei Tommaso Orzali Alexey Vert Mohammad-Ali Miri Pui Yee Hung Man Hoi Wong Andrea Alù Gennadi Bersuker Michael C. Downer 《Advanced Optical Materials》2021,9(16):2002252
Heteroepitaxial crystalline films underlie many electronic and optical technologies but are prone to forming defects at their heterointerfaces. Atomic-scale defects such as threading dislocations that propagate into a film impede the flow of charge carriers and light degrading electrical/optical performance of devices. Diagnosis of subsurface defects traditionally requires time-consuming invasive techniques such as cross-sectional transmission electron microscopy. Using III–V films grown on Si, noninvasive, bench-top diagnosis of subsurface defects have been demonstrated by optical second-harmonic scanning probe microscope. A high-contrast pattern is observed of subwavelength “hot spots” caused by scattering and localization of fundamental light by defect scattering sites. Size of these observed hotspots are strongly correlated to the density of dislocation defects. The results not only demonstrate a global and versatile method for diagnosing subsurface scattering sites but uniquely elucidate optical properties of disordered media. An extension to third harmonics would enable irregularities detection in non-χ(2) materials making the technique universally applicable. 相似文献
358.
Jiachuan Hua Pui Fai Ng Bin Fei 《Journal of polymer science. Part A, Polymer chemistry》2018,56(19):1325-1335
Hydrogels are a class of polymeric network materials embedded in a water-rich environment. They are widely applied in drug delivery, actuator, and sensor. However, conventional hydrogels encountered limits from their poor mechanical property. Recent researches in hydrogels have been focusing on mechanical enhancement, ranging from design of microstructures to adjustment of compositions in hydrogels. Here, the design and fabrication strategies of high-strength hydrogels, as well as major progress in their typical strength-support applications are systemically reviewed. © 2018 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2018 , 56, 1325–1335 相似文献
359.
In fracture mechanics, having the right crack path is a necessary condition for achieving reliable results. On the other hand, a discretized continuum is unable to represent a random crack path perfectly. Thus, challenges lie ahead on the accuracy of the numerical representation of this crack. Albeit the eigenfracture scheme has been well established in the recent years, different simulation results have shown some dependencies of the crack path on the mesh orientation, particularly when dealing with unstructured meshes. An r‐adaptive mesh refinement technique is introduced in this work, which circumvents possible mesh bias. In this regard, eroded finite elements are adaptively aligned in the direction of configurational forces calculated at the crack tip. Investigating the bounds of the eigenerosion scheme related to meshing and the introduction of possible improvements contribute to avoiding mesh induced anisotropy and further consolidate the approach. 相似文献
360.
Narcisa Vrinceanu Diana Tanasa Claudia Mihaela Hristodor Florin Brinza Eveline Popovici Daniel Gherca Aurel Pui Diana Coman Andreea Carsmariu Ionut Bistricianu Gianina Broasca 《Journal of Thermal Analysis and Calorimetry》2013,111(2):1107-1119
The research is aimed at synthesis and characterization of nanoscaled zinc oxide particles and their application on linen fibrous supports, for thermal properties. To impart thermal activity to the fibrous nanocomposites, nanoparticles as well as fibrous nanocomposites were produced in different hydrothermal conditions of temperature (90 °C). To characterize the nanoparticles composition, their shape, size, and crystallinity, investigations technique, such as Fourier transformed infrared spectroscopy, scanning electron microscopy, and X-ray powder diffractometry were used. Differential scanning calorimetry analysis profiles were also revealed. The thermal treatment of linen fabrics with nanosized ZnO does not modify significantly their thermal stability. 相似文献