Room temperature phosphorescence (RTP) has attracted broad attention due to their long lifetimes, large Stokes shift, and widespread applications. Achieving RTP emission has long been a challenging ...task under common conditions, for the necessary requirements of promoting intersystem crossing processes and suppressing nonradiative transitions are always tough to meet. Over the past decade, RTP has been obtained through several specific strategies, among which an important method lies in immobilizing phosphors into polymer matrices. Via the effect of steric overcrowding exerted by the polymeric structures, the phosphorescence of the initial phosphors can be promoted significantly. Hence, polymer‐based pure organic materials have proved to be one newly emerging subject in the field of RTP materials. In this review article, the progresses of polymer‐based pure organic room temperature phosphorescent materials are elaborated from four main approaches, including doped polymer systems, copolymer systems, homopolymer systems, and host–guest complexation systems, whereby the design principles, synthesis methods, possible mechanisms, and applications are summarized and discussed in detail.
The recent advances of polymer‐based pure organic room temperature phosphorescent materials are summarized, including design principle, synthesis methods, and potential applications. Possible mechanisms that have been proposed are also covered. And finally the critical challenges ahead are discussed, some proposals for future perspectives in the analysis foundation are put forward as well.
Constructing a powerful photocatalytic system that can achieve the carbon dioxide (CO2) reduction half‐reaction and the water (H2O) oxidation half‐reaction simultaneously is a very challenging but ...meaningful task. Herein, a porous material with a crystalline topological network, named viCOF‐bpy‐Re, was rationally synthesized by incorporating rhenium complexes as reductive sites and triazine ring structures as oxidative sites via robust −C=C− bond linkages. The charge‐separation ability of viCOF‐bpy‐Re is promoted by low polarized π‐bridges between rhenium complexes and triazine ring units, and the efficient charge‐separation enables the photogenerated electron–hole pairs, followed by an intramolecular charge‐transfer process, to form photogenerated electrons involved in CO2 reduction and photogenerated holes that participate in H2O oxidation simultaneously. The viCOF‐bpy‐Re shows the highest catalytic photocatalytic carbon monoxide (CO) production rate (190.6 μmol g−1 h−1 with about 100 % selectivity) and oxygen (O2) evolution (90.2 μmol g−1 h−1) among all the porous catalysts in CO2 reduction with H2O as sacrificial agents. Therefore, a powerful photocatalytic system was successfully achieved, and this catalytic system exhibited excellent stability in the catalysis process for 50 hours. The structure–function relationship was confirmed by femtosecond transient absorption spectroscopy and density functional theory calculations.
A crystalline network is constructed by incorporating rhenium complexes and triazine ring structures as catalytic sites via robust −C=C− bonding. Appreciable charge‐separation and transfer efficiency drive both the photocatalytic oxidative and reductive reactions in the conversion of CO2 to CO with H2O, and without any additional sacrificial agents or photosensitizers.
Abstract Unidirectional propagation of photons originated from perfect chirality meets the critical requirement for building a high-performance quantum network. However, it not only requires that the ...circular dipole emitter is precisely located at points of circularly polarized electric fields, which leads to non-reciprocal interactions for photons with opposite propagation directions, but also the light-emitter interaction strength should be strong enough to guarantee a π phase shift. Unfortunately, these perfect chirality points are scarce and accessible points with elliptically polarized fields result in non-ideal photon-emitter chiral interactions and emitters radiating photons bidirectionally. Meanwhile, reflection properties, phase shifts, and non-reciprocal interactions are sensitive to frequency detunings and dissipations. Here, without engineering the dipole and optimizing the distribution of the field, a scatter such as a nanotip placed at the evanescent field of a whispering gallery mode resonator (WGMR) is adopted to control the transporting properties of single photons under non-ideal chiral interactions. By properly adjusting the relative position between the nanotip and the atom or the overlap between the nanotip and the mode volume of the WGMR, amplitudes of reflected photons in different pathways are changed. Consequently, complete destructive interference appears and thus no photons are reflected. The corresponding phase shifts of π and non-reciprocal interactions are guaranteed simultaneously. Significantly, the perfect chirality reconstructed here is robust against frequency detunings and dissipations. Therefore, the atom-WGMR-nanotip structure can be regarded as a compound chiral atom with radiating photons in only one direction.
Sterile inflammation is an essential factor causing hepatic ischemia/reperfusion (I/R) injury. As a critical regulator of inflammation, the role of monocyte chemoattractant protein‐induced protein 1 ...(MCPIP1) in hepatic I/R injury remains undetermined. In this study, we discovered that MCPIP1 downregulation was associated with hepatic I/R injury in liver transplant patients and a mouse model. Hepatocyte‐specific Mcpip1 gene knockout and transgenic mice demonstrated that MCPIP1 functions to ameliorate liver damage, reduce inflammation, prevent cell death, and promote regeneration. A mechanistic study revealed that MCPIP1 interacted with and maintained hypoxia‐inducible factor 1α (HIF‐1α) expression by deubiquitinating HIF‐1α. Notably, the HIF‐1α inhibitor reversed the protective effect of MCPIP1, whereas the HIF‐1α activator compensated for the detrimental effect of MCPIP1 deficiency. Thus, we identified the MCPIP1–HIF‐1α axis as a critical pathway that may be a good target for intervention in hepatic I/R injury. (Hepatology 2018; 00:000‐000).
Angiotensin-converting enzyme 2 (ACE2) is a major cell entry receptor for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The induction of ACE2 expression may serve as a strategy by ...SARS-CoV-2 to facilitate its propagation. However, the regulatory mechanisms of ACE2 expression after viral infection remain largely unknown. Using 45 different luciferase reporters, the transcription factors SP1 and HNF4α were found to positively and negatively regulate ACE2 expression, respectively, at the transcriptional level in human lung epithelial cells (HPAEpiCs). SARS-CoV-2 infection increased the transcriptional activity of SP1 while inhibiting that of HNF4α. The PI3K/AKT signaling pathway, activated by SARS-CoV-2 infection, served as a crucial regulatory node, inducing ACE2 expression by enhancing SP1 phosphorylation-a marker of its activity-and reducing the nuclear localization of HNF4α. However, colchicine treatment inhibited the PI3K/AKT signaling pathway, thereby suppressing ACE2 expression. In Syrian hamsters (
) infected with SARS-CoV-2, inhibition of SP1 by either mithramycin A or colchicine resulted in reduced viral replication and tissue injury. In summary, our study uncovers a novel function of SP1 in the regulation of ACE2 expression and identifies SP1 as a potential target to reduce SARS-CoV-2 infection.
Polymer‐based pure organic room temperature phosphorescence (RTP) materials have garnered considerable interest, among which RTP systems with prolonged lifetimes and tunable emission colors are ...promising for applications in sensing, flexible electronics, bioassay, anti‐counterfeiting, and data encryption. Herein, facile doping method is reported based on two types of copolymers with benzene/biphenyl‐based light‐emitting cores as their side chains, whereby the two copolymers are robustly crosslinked via noncovalent interactions including hydrogen bonding and halogen bonding that occur between the light‐emitting cores and polyacrylamide backbones. Persistent RTP emission with prolonged lifetime up to 1.9 s and phosphorescence quantum yield as high as 40.1% are obtained in single copolymers, attributed to the conformation restriction of phosphorescent dyes originating from the rigid microenvironment. Furthermore, multicolor phosphorescence signals are observed in the doped binary luminescent copolymer systems that can be effectively regulated by the feed ratio of luminescent cores and irradiation wavelengths. Possible mechanisms for this efficient and long‐lived color‐tunable RTP system are discussed on the basis of the experimental data and theoretical calculations. In addition, it is also demonstrated that the color‐tunable RTP emission of the doped copolymer systems under ambient conditions allows for further exploitation in the application of dynamic information encryption.
A facile and highly efficient strategy is proposed to achieve color tunable emission with robust performance in polymer‐based pure organic room temperature phosphorescence materials through doping luminiferous polyacrylamide‐based binary copolymers. With the function of multiple intermolecular interactions, concentration‐dependent and irradiation‐dependent room temperature phosphorescence materials are obtained, which contains the strong restriction of covalent bonding and easy preparation of doping.
Canine mammary tumor (CMT) is the most common tumor in dogs, with 50% of malignant cases, and lacks an effective therapeutic schedule, hence its early diagnosis is of great importance to achieve a ...good prognosis. Microbiota is believed to play important roles in systemic diseases, including cancers. In this study, 91 tumors, 21 oral and fecal samples in total were collected from dogs with CMTs, and 31 oral and 21 fecal samples from healthy dogs were collected as control. The intratumoral, oral and gut bacterial community of dogs with CMTs and healthy dogs was profiled by 16S rRNA high-throughput sequencing and bioinformatic methods. The predominant intratumoral microbes were Ralstonia, Allorhizobium-Neorhizobium-Pararhizobium-Rhizobium, Pseudomonas, unidentified_Chloroplast and Bacteroides at the genus level. In addition, our findings demonstrated striking changes in the composition of the oral and gut bacterium community in the dogs suffered from CMTs compared to the healthy dogs, with a significant increase of Bacteroides which also was the significant microbial biomarker in the oral and gut bacterium community. It showed that the Bacteroides was shared in the intratumoral, oral and intestinal bacterial microbiomes, confirming that microbiota might travel from the mouth to the intestine and finally to the distant mammary tumor tissue. This study provides a new microbiological idea for the treatment of canine mammary tumors, and also provides a theoretical basis for the study of human breast cancer.
Down syndrome (DS), caused by trisomy of chromosome 21, occurs in 1 of every 800 live births. Early defects in cortical development likely account for the cognitive impairments in DS, although the ...underlying molecular mechanism remains elusive. Here, we performed histological assays and unbiased single-cell RNA-Seq (scRNA-Seq) analysis on cerebral organoids derived from 4 euploid cell lines and from induced pluripotent stem cells (iPSCs) from 3 individuals with trisomy 21 to explore cell-type-specific abnormalities associated with DS during early brain development. We found that neurogenesis was significantly affected, given the diminished proliferation and decreased expression of layer II and IV markers in cortical neurons in the subcortical regions; this may have been responsible for the reduced size of the organoids. Furthermore, suppression of the DSCAM/PAK1 pathway, which showed enhanced activity in DS, using CRISPR/Cas9, CRISPR interference (CRISPRi), or small-molecule inhibitor treatment reversed abnormal neurogenesis, thereby increasing the size of organoids derived from DS iPSCs. Our study demonstrates that 3D cortical organoids developed in vitro are a valuable model of DS and provide a direct link between dysregulation of the DSCAM/PAK1 pathway and developmental brain defects in DS.
Nonalcoholic fatty liver disease (NAFLD) is characterized by hepatic steatosis, impaired insulin sensitivity, and chronic low‐grade inflammation. However, the pathogenic mechanism of NAFLD is poorly ...understood, which hinders the exploration of possible treatments. Here, we report that ubiquitin‐specific protease 18 (USP18), a member of the deubiquitinating enzyme family, plays regulatory roles in NAFLD progression. Expression of USP18 was down‐regulated in the livers of nonalcoholic steatohepatitis patients and high‐fat diet (HFD)–induced or genetically obese mice. When challenged with HFD, hepatocyte‐specific USP18 transgenic mice exhibited improved lipid metabolism and insulin sensitivity, whereas mice knocked out of USP18 expression showed adverse trends regarding hepatic steatosis and glucose metabolic disorders. Furthermore, the concomitant inflammatory response was suppressed in USP18–hepatocyte‐specific transgenic mice and promoted in USP18–hepatocyte‐specific knockout mice treated with HFD. Mechanistically, hepatocyte USP18 ameliorates hepatic steatosis by interacting with and deubiquitinating transforming growth factorβ‐activated kinase 1 (TAK1), which inhibits TAK1 activation and subsequently suppresses the downstream c‐Jun N‐terminal kinase and nuclear factor kappa B signaling pathways. This is further validated by alleviated steatotic phenotypes and highly activated insulin signaling in HFD‐fed USP18–hepatocyte‐specific knockout mice administered a TAK1 inhibitor. The therapeutic effect of USP18 on NAFLD relies on its deubiquitinating activity because HFD‐fed mice injected with active‐site mutant USP18 failed to inhibit hepatic steatosis. Conclusion: USP18 associates with and deubiquitinates TAK1 to protect against hepatic steatosis, insulin resistance, and the inflammatory response. (Hepatology 2017;66:1866–1884)
Among all subtypes of breast cancer, triple-negative breast cancer has a relatively high relapse rate and poor outcome after standard treatment. Effective strategies to reduce the risk of relapse and ...death are needed.
To evaluate the efficacy and adverse effects of low-dose capecitabine maintenance after standard adjuvant chemotherapy in early-stage triple-negative breast cancer.
Randomized clinical trial conducted at 13 academic centers and clinical sites in China from April 2010 to December 2016 and final date of follow-up was April 30, 2020. Patients (n = 443) had early-stage triple-negative breast cancer and had completed standard adjuvant chemotherapy.
Eligible patients were randomized 1:1 to receive capecitabine (n = 222) at a dose of 650 mg/m2 twice a day by mouth for 1 year without interruption or to observation (n = 221) after completion of standard adjuvant chemotherapy.
The primary end point was disease-free survival. Secondary end points included distant disease-free survival, overall survival, locoregional recurrence-free survival, and adverse events.
Among 443 women who were randomized, 434 were included in the full analysis set (mean SD age, 46 9.9 years; T1/T2 stage, 93.1%; node-negative, 61.8%) (98.0% completed the trial). After a median follow-up of 61 months (interquartile range, 44-82), 94 events were observed, including 38 events (37 recurrences and 32 deaths) in the capecitabine group and 56 events (56 recurrences and 40 deaths) in the observation group. The estimated 5-year disease-free survival was 82.8% in the capecitabine group and 73.0% in the observation group (hazard ratio HR for risk of recurrence or death, 0.64 95% CI, 0.42-0.95; P = .03). In the capecitabine group vs the observation group, the estimated 5-year distant disease-free survival was 85.8% vs 75.8% (HR for risk of distant metastasis or death, 0.60 95% CI, 0.38-0.92; P = .02), the estimated 5-year overall survival was 85.5% vs 81.3% (HR for risk of death, 0.75 95% CI, 0.47-1.19; P = .22), and the estimated 5-year locoregional recurrence-free survival was 85.0% vs 80.8% (HR for risk of locoregional recurrence or death, 0.72 95% CI, 0.46-1.13; P = .15). The most common capecitabine-related adverse event was hand-foot syndrome (45.2%), with 7.7% of patients experiencing a grade 3 event.
Among women with early-stage triple-negative breast cancer who received standard adjuvant treatment, low-dose capecitabine maintenance therapy for 1 year, compared with observation, resulted in significantly improved 5-year disease-free survival.
ClinicalTrials.gov Identifier: NCT01112826.
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