Zobrazení zdroje stránky Abramsfalkenberg9074

Specificity of DNA polymerization plays a critical role in DNA replication and storage of genetic information. Likewise, biotechnological applications, such as nucleic acid detection, DNA amplification, and gene cloning, require high specificity in DNA synthesis catalyzed by DNA polymerases. However, errors in DNA polymerization (such as mis-incorporation and mis-priming) can significantly jeopardize the specificity. Herein, we report our discovery that the specificity of DNA enzymatic synthesis can be substantially enhanced (up to 100-fold higher) by attenuating DNA polymerase kinetics via the phosphorothioate dNTPs. This specificity enhancement allows convenient and sensitive nucleic acid detection, polymerization, PCR, and gene cloning with complex systems (such as human cDNA and genomic DNA). Further, we found that the specificity enhancement offered higher sensitivity (up to 50-fold better) for detecting nucleic acids, such as COVID-19 viral RNAs. Our findings have revealed a simple and convenient strategy for facilitating specificity and sensitivity of nucleic acid detection, amplification, and gene cloning.The development of organic solids for applications in materials science requires a fundamental understanding of how close packing of molecules can affect structure and function. We report here nonporous organic crystals that release entrapped guest molecules upon application of UV light. We show components of binary cocrystal solvates to undergo an intermolecular photoreaction to generate ternary cocrystals that results in release of entrapped solvent molecules. The phototriggered guest release occurs in a single-crystal-to-single-crystal transformation that is in the absence pores and channels in the solid. The cocrystals are composed of a tetratopic hydrogen-bond-acceptor molecule synthesized in the solid state. The UV-light results in [2 + 2] photodimerization of an isocoumarin to generate a ternary cocrystal with cyclobutane molecules that support guest release.Water oxidation is a primary step in natural as well as artificial photosynthesis to convert renewable solar energy into chemical energy/fuels. Electrocatalytic water oxidation to evolve O2, utilizing suitable low-cost catalysts and renewable electricity, is of fundamental importance considering contemporary energy and environmental issues, yet it is kinetically challenging owing to the complex multiproton/electron transfer processes. Herein, we report the first cobalt-based pincer catalyst for catalytic water oxidation at neutral pH with high efficiency under electrochemical conditions. Most importantly, ligand (pseudo)aromaticity is identified to play an important role during electrocatalysis. A significant potential jump (∼300 mV) was achieved toward a lower positive value when the aromatized cobalt complex was transformed into a (pseudo)dearomatized cobalt species. The dearomatized species catalyzes the water oxidation reaction to evolve oxygen at a much lower overpotential (∼340 mV) on the basis of the onset potential (at a current density of 0.5 mA/cm2) of catalysis at pH 10.5, outperforming other Co-based molecular catalysts reported to date. These observations may provide a new strategy for the judicious design of earth-abundant transition-metal-based water oxidation catalysts.Staphylococcus aureus is a primary pathogen responsible for causing postoperative infections as it survives and persists in host cells, including osteoblasts and macrophages. These cells then serve as reservoirs resulting in chronic infections. Most traditional antibiotics have poor effects on intracellular S. aureus because they cannot enter the cell. Herein, a cell-penetrating peptide TAT-KR-12 was derived from the trans-activating transcription (TAT) peptide and KR-12 (residues 18-29 of human cathelicidin LL-37). The TAT acts as a "trojan horse" to deliver KR-12 peptide into the cells to kill S. aureus. Moreover, effective antibacterial properties and biocompatibility were observed in vitro, demonstrating that TAT-KR-12 is effective not only in eliminating planktonic S. [https://www.selleckchem.com/products/17-AAG(Geldanamycin).html this website] aureus, but also in eliminating intracellular S. aureus cells in vitro. TAT-KR-12, as with LL-37, also elicits strong anti-inflammatory activities in LPS-stimulated macrophages, as demonstrated by significant inhibition of NO, TNF-α, and IL-1β expression and secretion from LPS-stimulated RAW264.7 cells. In the subcutaneous infection mouse model of planktonic and intracellular infections, the growth of S. aureusin vivo is evidently inhibited without cytotoxicity. These results suggest that the novel antimicrobial TAT-KR-12 may prove to be an effective treatment option to overcome antibiotic resistance caused by intracellular bacterial infections.Self-delivery of photosensitizer and immune modulator to tumor site is highly recommendable to improve the photodynamic immunotherapy yet remains challenging. Herein, self-delivery photoimmune stimulators (designated as iPSs) are developed for photodynamic sensitized tumor immunotherapy. Carrier-free iPSs are constructed by optimizing the noncovalent interactions between the pure drugs of chlorine e6 (Ce6) and NLG919, which avoid the excipients-raised toxicity and immunogenicity. Intravenously administrated iPSs prefer to passively accumulate on tumor tissues for a robust photodynamic therapy (PDT) with the induction of immunogenetic cell death (ICD) cascade to activate cytotoxic T lymphocytes (CTLs) and initiate antitumor immune response. Meanwhile, the concomitant delivery of NLG919 inhibits the activation of indoleamine 2,3-dioxygenase 1 (IDO-1) to reverse the immunosuppressive tumor microenvironment. Ultimately, the photodynamic sensitized immunotherapy with iPSs efficiently inhibit the primary and distant tumor growth with a low system toxicity, which would shed light on the development of self-delivery nanomedicine for clinical transformation in tumor precision therapy.Bladder cancer displays multiple biological features aided in drug resistance; therefore, single therapy fails to induce complete tumor regression. To address this issue, various kinds of cell death of cancer cells as well as restoring tumor immune microenvironment need to be taken into consideration. Here, we introduce a gel system termed AuNRs&amp;IONs@Gel, which target-delivers a combination of photothermal, ferroptotic, and immune therapy through intravesical instillation. AuNRs&amp;IONs@Gel consists of a gel delivery platform, embedded gold nanorods (AuNRs), and iron oxide nanoparticles (IONs). The targeted delivery gel platform provides dextran aldehyde-selective adhesion with cancer collagen. In this condition, photothermal therapy can be performed by gold nanorods (AuNRs) under imaging-guided near-infrared radiation. Local high concentrations of IONs can be absorbed by cancer cell to induce ferroptosis. Moreover, tumor-associated macrophages which often display an immune-suppressive M2-like phenotype will be repolarized by IONs into the antitumor M1-like phenotype, exerting a direct antitumor effect and professional antigen presentation of dead cancer cells.