Using light as a local heat source to induce a temporary pyroelectric current is widely recognized as an effective way to control the polarization of crystalline materials. In contrast, harnessing ...light directly to modulate the polarization of a crystal via excitation of the electronic bands remains less explored. In this study, we report an FeII spin crossover crystal that exhibits photoinduced macroscopic polarization change upon excitation by green light. When the excited crystal relaxes to the ground state, the corresponding pyroelectric current can be detected. An analysis of the structures, magnetic properties and the Mössbauer and infrared spectra of the complex, supported by calculations, revealed that the polarization change is dictated by the directional relative movement of ions during the spin transition process. The spin transition and polarization change occur simultaneously in response to light stimulus, which demonstrates the enormous potential of polar spin crossover systems in the field of optoelectronic materials.
A photoinduced persistent polarization change was achieved in an ionic FeII spin‐crossover complex by combining the light‐induced excited spin‐state trapping effect (LIESST) and macroscopic polarization. The pyroelectric current is detected at a crystal level when the light‐induced metastable state returns to the ground state. This study provides a platform for the development of optoelectric materials.
Full text
Available for:
BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
Background/Aims: Programmed death ligand1(PD-L1) plays a role in the development and progression of non-small cell lung cancer (NSCLC). This study aimed to identify miRNA(s) that are responsible for ...regulation of expression of PD-L1 in NSCLC, and to investigate the role of PD-L1 in regulation of the cell cycle in NSCLC. Methods: We predicted the target miRNA of PD-L1, which was miR-140, using the online tools TargetScan and miBase. In NSCLC cells obtained from clinical specimens, in addition to A549 and NCI-H1650 cell cultures, western blots were used to detect the level of expression of proteins, while real-time PCR was used to determine the level of expression of PD-L1, miR-140, cyclin E, and β-actin. Transfection with miR-140 mimics, miR-140 inhibitors, and PD-L1 siRNA were conducted using commercial kits. To determine whether miR-140 directly binds PD-L1, a luciferase reporter gene with wild type or mutated PD-L1 was used. Cell viability was measured with the MTT assay, and PI staining was used for cell cycle analysis. Results: We found low expression of miR-140 and high expression of PD-L1 and cyclin E in NSCLC cells. Over-expression of miR-140 suppressed the expression of PD-L1 by directly binding its 3’ UTR, and was also associated with decreased expression of cyclin E and inhibition of cellular proliferation in A549 and NCI-H1650 cells. Inhibition of PD-L1, in the absence of manipulations to miR-140, also decreased the expression of cyclin E. Conclusion: We conclude that miR-140 directly suppresses PD-L1 and inhibits the miR-140/PD-L1/cyclin E pathway in NSCLC.
Size‐dependent nonlinear optical properties of modification‐free transition metal dichalcogenide (TMD) nanosheets are reported, including MoS2, WS2, and NbSe2. Firstly, a gradient centrifugation ...method is demonstrated to separate the TMD nanosheets into different sizes. The successful size separation allows the study of size‐dependent nonlinear optical properties of nanoscale TMD materials for the first time. Z‐scan measurements indicate that the dispersion of MoS2 and WS2 nanosheets that are 50–60 nm thick leads to reverse saturable absorption (RSA), which is in contrast to the saturable absorption (SA) seen in the thicker samples. Moreover, the NbSe2 nanosheets show no size‐dependent effects because of their metallic nature. The mechanism behind the size‐dependent nonlinear optical properties of the semiconductive TMD nanosheets is revealed by transient transmission spectra measurements.
The size‐dependent nonlinear optical response of three, atomically thin, transition metal dichalcogenides is studied. Size separation of transition metal dichalcogenides is achieved by gradient centrifugation. Most of the large flakes show saturated absorption but WS2 nanosheets thinner than 50–60 nm exhibit reverse saturated absorption.
Full text
Available for:
BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
Icariin (ICA) has a significant capacity to protect against depression and hippocampal injury, but it cannot effectively cross the blood-brain barrier and accumulate in the brain. Therefore, the ...mechanism by which ICA protects against hippocampal injury in depression remains unclear. In this study, we performed proteomics analysis of cerebrospinal fluid to investigate the mechanism by which ICA prevents dysfunctional hippocampal neurogenesis in depression. A rat model of depression was established through exposure to chronic unpredictable mild stress for 6 weeks, after which 120 mg/kg ICA was administered subcutaneously every day. The results showed that ICA alleviated depressive symptoms, learning and memory dysfunction, dysfunctional neurogenesis, and neuronal loss in the dentate gyrus of rats with depression. Neural stem cells from rat embryonic hippocampi were cultured in media containing 20% cerebrospinal fluid from each group of rats and then treated with 100 μM corticosterone. The addition of cerebrospinal fluid from rats treated with ICA largely prevented the corticosterone-mediated inhibition of neuronal proliferation and differentiation. Fifty-two differentially expressed proteins regulated by chronic unpredictable mild stress and ICA were identified through proteomics analysis of cerebrospinal fluid. These proteins were mainly involved in the ribosome, PI3K-Akt signaling, and interleukin-17 signaling pathways. Parallel reaction monitoring mass spectrometry showed that Rps4x, Rps12, Rps14, Rps19, Hsp90b1, and Hsp90aa1 were up-regulated by chronic unpredictable mild stress and down-regulated by ICA. In contrast, HtrA1 was down-regulated by chronic unpredictable mild stress and up-regulated by ICA. These findings suggest that ICA can prevent depression and dysfunctional hippocampal neurogenesis through regulating the expression of certain proteins found in the cerebrospinal fluid. The study was approved by the Experimental Animal Ethics Committee of Guangzhou University of Chinese Medicine of China in March 2017.
A series of dynamic single crystals with a chemical formula of MII(en)3SO4 (en = ethylene and MII = NiII, MnII, and CdII) was synthesized. As the temperature decreases, these materials exhibit ...dielectric switching in the vicinity of the phase transition point accompanied by anisotropic thermal expansion in the cell parameters as a consequence of the order–disorder structural change of SO42− in a cavity surrounded by five MII(en)32+ complex cations. Because the variation of metal centers with different ionic radii changes the shape of the complex cation, which affects the distribution of hydrogen-bond interactions around the SO42−, the dynamic motion of SO42− is substantially tuned. Correspondingly, the dielectric properties and anisotropic thermal expansion of materials were largely shifted, especially in the single crystals of MnII(en)3SO4, whose structural change is distinctly different from the crystals of Ni(ii) and Cd(ii). The detailed structural mechanism accounting for the different physical properties of these materials was discussed.
Bromodomain-containing protein 4 (BRD4) is a cancer therapeutic target in ongoing clinical trials disrupting primarily BRD4-regulated transcription programs. The role of BRD4 in cancer has been ...attributed mainly to the abundant long isoform (BRD4-L). Here we show, by isoform-specific knockdown and endogenous protein detection, along with transgene expression, the less abundant BRD4 short isoform (BRD4-S) is oncogenic while BRD4-L is tumor-suppressive in breast cancer cell proliferation and migration, as well as mammary tumor formation and metastasis. Through integrated RNA-seq, genome-wide ChIP-seq, and CUT&RUN association profiling, we identify the Engrailed-1 (EN1) homeobox transcription factor as a key BRD4-S coregulator, particularly in triple-negative breast cancer. BRD4-S and EN1 comodulate the extracellular matrix (ECM)-associated matrisome network, including type II cystatin gene cluster, mucin 5, and cathepsin loci, via enhancer regulation of cancer-associated genes and pathways. Our work highlights the importance of targeted therapies for the oncogenic, but not tumor-suppressive, activity of BRD4.
Display omitted
•Oncogenic BRD4-S and tumor-suppressive BRD4-L in breast cancer•Inducible BRD4-L/S transgenic mice exhibiting opposing functions of BRD4 isoforms•Genome-wide RNA-seq, ChIP-seq, and CUT&RUN profiling of BRD4-S and BRD4-L•EN1/BRD4-S-coregulated enhancer modulating the matrisome ECM network
With BRD4 isoform-specific antibodies and knockdown and mouse xenograft and transgene expression, Wu et al. demonstrate oncogenic BRD4-S and tumor-suppressive BRD4-L have opposing functions in breast cancer initiation and development, partly through enhancer regulation of matrisome extracellular network modulating cancer cell migration and metastasis.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
•Desalination membranes with hierarchically aligned channels were fabricated.•The membrane exhibited a superior pure water generation rate of 2.37 kg m−2 h−1 (one sun).•The geometrical effect of ...hierarchical channels has been studied in detail.
Solar-powered interfacial evaporation attracts enormous attention to solve the water crisis as a low-energy consumption, high energy conversion efficiency, and environmental-friendliness technology. Balancing water transport, water content and interfacial temperature is critical to promote evaporation performance. However, fabrication methods and investigation of dedicatedly-designed structures and channel sizes for solar-powered interfacial evaporation have been rarely reported. Herein, we propose to employ vertically aligned channels with hierarchy sizes to modulate water evaporation and energy efficiency. This unique structure is fabricated by a three-step procedure including freeze-drying, ion cross-linking, and hydrogen bond reconstruction in sequence, which achieves a membrane with vertically aligned channels ranging from 1 nm to tons of micrometers. Our solar-powered distillation membrane with finely-modulated hierarchical structure exhibits a high pure water generation rate of 2.37 kg m−2 h−1 under one sun illumination. Even when treated with seawater, it can achieve a capacity of 2.34 kg m−2 h−1 (10 wt% seawater) and stabilize a high evaporation rate for at least 50 h, which is superior to most reported solar empowered distillation membranes. Our distillation membrane features a high mechanical strength and low cost, making it an appealing candidate for the actual application in desalination.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Exposure to microgravity can adversely affect the fitness of astronauts. The integrity of the skin plays a crucial role in protecting against mechanical forces and infections, fluid imbalance, and ...thermal dysregulation. In brief, the skin wound may cause unknown challenges to the implementation of space missions. Wound healing is a physiological process that relies on the synergistic action of inflammatory cells, extracellular matrix (ECM), and various growth factors to maintain the integrity of skin after trauma. Fibroblasts are present almost throughout the entire process of wound repair, especially in the scar formation at the endpoint of wound healing. However, there is limited knowledge about the extent to which fibroblasts are affected by the lack of gravity during wound healing. In this study, we utilized the rotary cell culture system, a ground‐based facility that mimics the weightless condition, to study the alterations of L929 fibroblast cells under simulated microgravity (SMG). Our results demonstrated that the SM condition exerted negative influences on the proliferation and ECM formation of the L929 fibroblast. Whereas, the apoptosis of fibroblast was significantly upregulated upon exposure to SMG conditions. Moreover, the transforming growth factor‐β1/Smad3 (TGF‐β1/smad3) signaling pathway of L929 fibroblast related to wound repair was also altered significantly under a weightless environment. Overall, our study provided evidence that fibroblasts are strongly sensitive to SMG and elucidated the potential value of the TGF‐β1/Smad3 signaling pathway modulating wound healing in the future practice of space medicine.
Full text
Available for:
BFBNIB, DOBA, FZAB, GIS, IJS, IZUM, KILJ, NLZOH, NUK, OILJ, PILJ, PNG, SAZU, SBCE, SBMB, UILJ, UKNU, UL, UM, UPUK
PDF
