The preparation of chiral monohydrosilanes remains a rarely achieved goal. To this end a Rh‐catalyzed desymmetrization of dihydrosilanes by way of intramolecular C(sp2)−H functionalization under ...simple and mild conditions has now been developed. This method provides easy access to a broad range of chiral monohydrosilanes in good yields with excellent enantioselectivities (up to >99 % ee). The resulting monohydrosilanes constitute a good platform to access stereogenic silicon compounds, as well as useful compounds to probe silicon stereochemistry.
A Rh‐chiral diphosphine complex was found to catalyze desymmetrization of dihydrosilanes by formal intramolecular Si−H/C−H dehydrogenative coupling reactions. This simple, mild, and practical method results in unprecedently high enantioselectivity and a broad substrate scope. The chiral monohydrosilanes could be further elaborated into various stereogenic silicon compounds in a stereospecific manner.
To provide an updated summary of recent advances in our understanding of the non-canonical roles of apoptotic and DNA double-strand break repair factors in various biological processes, especially in ...the cellular response to radiotherapy.
Apoptotic caspases are usually considered as "executioners'' of unwanted or damaged cells or tissues. However, recent studies indicated they play multiple additional, often counterintuitive roles in many biological processes. Similarly, DNA double-strand break (DSB) repair factors were also found to play unexpected roles beyond repairing damaged DNA. In this review, I will summarize key findings on the non-canonical roles of apoptotic and DSB repair factors in disparate biological and pathological processes such as radiation-induced genetic instability and carcinogenesis, wound healing and tissue regeneration, induced pluripotent stem cell induction, spontaneous and stochastic generation of cancer stem cells, and cancer immunotherapy. I believe these findings will usher in more studies in this exciting and rapidly evolving field.
Caspase‐3 (CASP3) is a major mediator of apoptosis activated during cellular exposure to cytotoxic drugs, radiotherapy or immunotherapy. It is often used as a marker for efficacy of cancer therapy. ...However, recent reports indicate that caspase‐3 has also non‐apoptotic roles such as promotion of tumor relapse and tumor angiogenesis. Therefore, the roles of caspase‐3 in tumor progression remain to be defined clearly. In our study, we established caspase‐3 knockout (KO) colon cancer cell lines by use of the CRISPR technology. In vitro, caspase‐3 knockout HCT116 cells were significantly less clonogenic in soft agar assays. They were also significantly less invasive and more sensitive to radiation and mitomycin C than control cells. In vivo, CASP3KO cells formed tumors at rates similar to control cells but were significantly more sensitive to radiotherapy. They were also less prone to pulmonary metastasis when inoculated either subcutaneously or intravenously. At the mechanistic level, caspase‐3 gene knockout appeared to cause reduced EMT phenotypes when compared to parental HCT116 cells. Indeed, they showed significantly increased E‐cadherin expression, reduced N‐cadherin, Snail, Slug and ZEB1 expression than control cells. Therefore, therapeutic targeting of caspase‐3 may not only increase the sensitivity of cancer cell to chemotherapy and radiotherapy, but also inhibit cancer cell invasion and metastasis.
What's new?
The main function of caspase‐3 is to eliminate damaged cells. Following activation, it cleaves proteins vital to cell function, thereby fueling apoptosis. As a result, caspase‐3 generally is thought to be a beneficial factor in cancer therapy. This study shows, however, that caspase‐3 plays important roles in promoting colon cancer cell invasion and metastasis. Compared to control cells, caspase‐3 knockout colon cancer cells (CASP3KO) demonstrated significantly reduced invasive potential in vitro. In vivo, tumors formed by CASP3KO cells exhibited increased sensitivity to radiotherapy and reduced metastatic tendency. The findings suggest that caspase‐3 is a potential target for colon cancer therapy.
The features of well-conjugated and planar aromatic structures make π-conjugated luminescent materials suffer from aggregation caused quenching (ACQ) effect when used in solid or aggregated states, ...which greatly impedes their applications in optoelectronic devices and biological applications. Herein, we reduce the ACQ effect by demonstrating a facile and low cost method to co-assemble polycyclic aromatic hydrocarbon (PAH) chromophores and octafluoronaphthalene together. Significantly, the solid photoluminescence quantum yield (PLQYs) for the as-resulted four micro/nanococrystals are enhanced by 254%, 235%, 474 and 582%, respectively. Protection from hydrophilic polymer chains (P123 (PEO
-PPO
-PEO
)) endows the cocrystals with superb dispersibility in water. More importantly, profiting from the above-mentioned highly improved properties, nano-cocrystals present good biocompatibility and considerable cell imaging performance. This research provides a simple method to enhance the emission, biocompatibility and cellular permeability of common chromophores, which may open more avenues for the applications of originally non- or poor fluorescent PAHs.
A great challenge in producing TiC reinforced metal matrix composites is encountered to directly add TiC particles into molten steel during casting owing to floating of nano-sized TiC on molten ...steels and agglomeration. As such, this work proposes a novel strategy using pre-distribution in situ nano-sized TiC/Al master alloy to fabricate 45 steel matrix composites reinforced with trace nano-sized TiC particles while without changing the original casting process; this strategy can effectively avoid the aforementioned challenge. The average grain sizes of as-cast and heat-treated 45 steel with 0.018 wt% nano-sized TiC particles remarkably decrease from 14.75 μm to 9.51 μm respectively to 8.77 μm and 5.46 μm respectively, which is attributed to that the nanoparticles provide effective nucleation sites and inhibit grain growth. Furthermore, adding trace nano-sized TiC particles significantly enhances their strength and toughness. The 45 steel matrix composites reinforced with 0.054 wt% nano-sized TiC particles exhibits the best tensile mechanical properties with yield strength of 624 MPa, ultimate strength of 920 MPa, elongation of 23.8% and impact toughness of 50.21 J/cm2, which are 19%, 13%, 10% and 38% respectively higher than the 45 steel. The strengthening and toughening mechanisms of 45 steel by nano-sized TiC are attributed to grain boundary strengthening, work hardening and dispersion strengthening. The strategy proposed in this work may provide a promising method for enhancing steel performances for industrial productions.
•Using pre-distribution TiC/Al master alloy to fabricate 45 steel matrix composites.•Microstructure of 45 steels is significantly refined by trace nano-TiC.• 45steel matrix composites exhibit significantly improved strength and toughness.•New strategy is fabricated for 45 steel matrix composites reinforced with nano-TiC.
Emotional labor is common in nursing but may be affected by the mental state of nurses. This study explored the effect of compassion fatigue on emotional labor and whether self-compassion moderates ...this effect of compassion fatigue.
A two-stage survey design with a convenience sample. Participants were female nursing staff recruited from emergency departments, intensive care units, ward nursing units, and outpatient departments of medical centers, regional hospitals, and district hospitals in Taiwan. A total of 300 questionnaire copies in each of the first and second stages were distributed, and 272 pairs of responses were retrieved (valid response rate = 91%). The reliability and validity of the questionnaire were tested, and confirmatory factor analysis was conducted with AMOS 21. The proposed hypotheses were verified using hierarchical regression conducted with SPSS version 25.0.
This study revealed that compassion fatigue positively predicted surface acting (β = 0.12, p < 0.05) and negatively predicted deep acting (β = -0.18, p < 0.01) and expression of genuine emotions (β = -0.31, p < 0.01). In addition, self-compassion negatively moderates the relationships between compassion fatigue and surface acting (β = -0.12, p < 0.05), and positively moderates the relationships between compassion fatigue and expression of genuine emotions (β = 0.15, p < 0.01).
To avoid excessive consumption of emotional resources, nurses with high compassion fatigue may employ surface acting by engaging in emotional labor without making an effort to adjust their feelings. Nurses need also be sympathized with, and such sympathy can come from hospitals, supervisors, colleagues, and, most crucially, the nurses themselves. Hospital executives should propose improvement strategies that can prevent the compassion fatigue on nurses, such as improving nurses' self-compassion.
•SRB EPS included carboxyl, thiol/phosphate, amino/hydroxyl functional groups.•Heavy metals had no effect on the type of functional groups of the EPS samples.•Heavy metals increased the ...concentrations of the surface functional groups.•EPS extracted from the Zn2+-dosed system had a higher binding affinity.•Zn2+ could decrease the toxic effects of Cu2+ and Cd2+ on the SRB.
Extracellular polymeric substances (EPS) play an important role in the treatment of acid mine drainage (AMD) by sulfate-reducing bacteria (SRB). In this paper, Desulfovibrio desulfuricans was used as the test strain to explore the effect of heavy metals on the components and adsorption ability of EPS. Fourier-transform infrared (FTIR) spectroscopy analysis results showed that heavy metals did not influence the type of functional groups of EPS. Potentiometric titration results indicated that the acidic constants (pKa) of the EPS fell into three ranges of 3.5–4.0, 5.9–6.7, and 8.9–9.8. The adsorption site concentrations of the surface functional groups also increased. Adsorption results suggested that EPS had a specific binding affinity for the dosed heavy metal, and that EPS extracted from the Zn2+-dosed system had a higher binding affinity for all heavy metals. Additionally, Zn2+ decreased the inhibitory effects of Cd2+ and Cu2+ on the SRB.
The engagement of programmed cell death protein 1 (PD-1; encoded by the PDCD1 gene) receptor expressed on activated T cells and its ligand, programmed death-ligand 1 (PD-L1; encoded by the CD274 ...gene), is a major co-inhibitory checkpoint signaling that controls T cell activities. Various types of cancers express high levels of PD-L1 and exploit PD-L1/PD-1 signaling to evade T cell immunity. Blocking the PD-L1/PD-1 pathway has consistently shown remarkable anti-tumor effects in patients with advanced cancers and is recognized as the gold standard for developing new immune checkpoint blockade (ICB) and combination therapies. However, the response rates of anti-PD-L1 have been limited in several solid tumors. Therefore, furthering our understanding of the regulatory mechanisms of PD-L1 can bring substantial benefits to patients with cancer by improving the efficacy of current PD-L1/PD-1 blockade or other ICBs. In this review, we provide current knowledge of PD-L1 regulatory mechanisms at the transcriptional, posttranscriptional, post-translational, and extracellular levels, and discuss the implications of these findings in cancer diagnosis and immunotherapy.
Immune checkpoint programmed death-ligand 1 (PD-L1) plays a critical role in facilitating tumor immune evasion. Cha et al. discuss the mechanisms regulating PD-L1 expression and explore how targeting those mechanisms may lead to potential therapeutic strategies and biomarkers to improve response rates to immunotherapy.
With the popularization of the intelligent manufacturing, much attention has been paid in such intelligent computing methods as deep learning ones for machinery fault diagnosis. Thanks to the ...development of deep learning models, the interference of the human experience can be greatly reduced, and the fault diagnosis accuracy can also be increased under certain conditions. To improve the generalization ability of the intelligent fault diagnostics, the deep transfer learning consisting of both transfer learning and deep learning components was accordingly developed. This paper reviews the research progress of the deep transfer learning for the machinery fault diagnosis in recently years. It is summarizing, classifying and explaining many publications on this topic with discussing various deep transfer architectures and related theories. On this basis, this review expounds main achievements, challenges and future research of the deep transfer learning. This provides clear directions for the selection, design or implementation of the deep transfer learning architecture in the field of the machinery fault diagnostics.
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