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1.
Mol Cell ; 82(11): 2032-2049.e7, 2022 06 02.
Artigo em Inglês | MEDLINE | ID: mdl-35460603

RESUMO

Virus infection modulates both host immunity and host genomic stability. Poly(ADP-ribose) polymerase 1 (PARP1) is a key nuclear sensor of DNA damage, which maintains genomic integrity, and the successful application of PARP1 inhibitors for clinical anti-cancer therapy has lasted for decades. However, precisely how PARP1 gains access to cytoplasm and regulates antiviral immunity remains unknown. Here, we report that DNA virus induces a reactive nitrogen species (RNS)-dependent DNA damage and activates DNA-dependent protein kinase (DNA-PK). Activated DNA-PK phosphorylates PARP1 on Thr594, thus facilitating the cytoplasmic translocation of PARP1 to inhibit the antiviral immunity both in vitro and in vivo. Mechanistically, cytoplasmic PARP1 interacts with and directly PARylates cyclic GMP-AMP synthase (cGAS) on Asp191 to inhibit its DNA-binding ability. Together, our findings uncover an essential role of PARP1 in linking virus-induced genome instability with inhibition of host immunity, which is of relevance to cancer, autoinflammation, and other diseases.


Assuntos
Antivirais , Nucleotidiltransferases , Antivirais/farmacologia , Citoplasma/genética , Citoplasma/metabolismo , DNA , Dano ao DNA , Instabilidade Genômica , Humanos , Nucleotidiltransferases/genética , Nucleotidiltransferases/metabolismo , Poli(ADP-Ribose) Polimerase-1/metabolismo
2.
Nature ; 593(7857): 56-60, 2021 05.
Artigo em Inglês | MEDLINE | ID: mdl-33953409

RESUMO

Exciting phenomena may emerge in non-centrosymmetric two-dimensional electronic systems when spin-orbit coupling (SOC)1 interplays dynamically with Coulomb interactions2,3, band topology4,5 and external modulating forces6-8. Here we report synergetic effects between SOC and the Stark effect in centrosymmetric few-layer black arsenic, which manifest as particle-hole asymmetric Rashba valley formation and exotic quantum Hall states that are reversibly controlled by electrostatic gating. The unusual findings are rooted in the puckering square lattice of black arsenic, in which heavy 4p orbitals form a Brillouin zone-centred Γ valley with pz symmetry, coexisting with doubly degenerate D valleys of px origin near the time-reversal-invariant momenta of the X points. When a perpendicular electric field breaks the structure inversion symmetry, strong Rashba SOC is activated for the px bands, which produces spin-valley-flavoured D± valleys paired by time-reversal symmetry, whereas Rashba splitting of the Γ valley is constrained by the pz symmetry. Intriguingly, the giant Stark effect shows the same px-orbital selectiveness, collectively shifting the valence band maximum of the D± Rashba valleys to exceed the Γ Rashba top. Such an orchestrating effect allows us to realize gate-tunable Rashba valley manipulations for two-dimensional hole gases, hallmarked by unconventional even-to-odd transitions in quantum Hall states due to the formation of a flavour-dependent Landau level spectrum. For two-dimensional electron gases, the quantization of the Γ Rashba valley is characterized by peculiar density-dependent transitions in the band topology from trivial parabolic pockets to helical Dirac fermions.

3.
Nucleic Acids Res ; 52(9): 5107-5120, 2024 May 22.
Artigo em Inglês | MEDLINE | ID: mdl-38554113

RESUMO

Sirtuin 2 (SIRT2) regulates the maintenance of genome integrity by targeting pathways of DNA damage response and homologous recombination repair. However, whether and how SIRT2 promotes base excision repair (BER) remain to be determined. Here, we found that independent of its catalytic activity SIRT2 interacted with the critical glycosylase OGG1 to promote OGG1 recruitment to its own promoter upon oxidative stress, thereby enhancing OGG1 promoter activity and increasing BER efficiency. Further studies revealed that SIRT2 was phosphorylated on S46 and S53 by ATM/ATR upon oxidative stress, and SIRT2 phosphorylation enhanced the SIRT2-OGG1 interaction and mediated the stimulatory effect of SIRT2 on OGG1 promoter activity. We also characterized 37 cancer-derived SIRT2 mutants and found that 5 exhibited the loss of the stimulatory effects on OGG1 transcription. Together, our data reveal that SIRT2 acts as a tumor suppressor by promoting OGG1 transcription and increasing BER efficiency in an ATM/ATR-dependent manner.


Assuntos
Proteínas Mutadas de Ataxia Telangiectasia , DNA Glicosilases , Reparo do DNA , Sirtuína 2 , Proteínas Mutadas de Ataxia Telangiectasia/metabolismo , Proteínas Mutadas de Ataxia Telangiectasia/genética , Humanos , Sirtuína 2/metabolismo , Sirtuína 2/genética , DNA Glicosilases/metabolismo , DNA Glicosilases/genética , Fosforilação , Regiões Promotoras Genéticas , Estresse Oxidativo , Ativação Transcricional , Células HEK293 , Dano ao DNA , Transcrição Gênica , Linhagem Celular Tumoral , Reparo por Excisão
4.
Hepatology ; 79(2): 289-306, 2024 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-37540187

RESUMO

BACKGROUND AND AIMS: Molecular classification is a promising tool for prognosis prediction and optimizing precision therapy for HCC. Here, we aimed to develop a molecular classification of HCC based on the fatty acid degradation (FAD) pathway, fully characterize it, and evaluate its ability in guiding personalized therapy. APPROACH AND RESULTS: We performed RNA sequencing (RNA-seq), PCR-array, lipidomics, metabolomics, and proteomics analysis of 41 patients with HCC, in which 17 patients received anti-programmed cell death-1 (PD-1) therapy. Single-cell RNA sequencing (scRNA-seq) was performed to explore the tumor microenvironment. Nearly, 60 publicly available multiomics data sets were analyzed. The associations between FAD subtypes and response to sorafenib, transarterial chemoembolization (TACE), immune checkpoint inhibitor (ICI) were assessed in patient cohorts, patient-derived xenograft (PDX), and spontaneous mouse model ls. A novel molecular classification named F subtype (F1, F2, and F3) was identified based on the FAD pathway, distinguished by clinical, mutational, epigenetic, metabolic, and immunological characteristics. F1 subtypes exhibited high infiltration with immunosuppressive microenvironment. Subtype-specific therapeutic strategies were identified, in which F1 subtypes with the lowest FAD activities represent responders to compounds YM-155 and Alisertib, sorafenib, anti-PD1, anti-PD-L1, and atezolizumab plus bevacizumab (T + A) treatment, while F3 subtypes with the highest FAD activities are responders to TACE. F2 subtypes, the intermediate status between F1 and F3, are potential responders to T + A combinations. We provide preliminary evidence that the FAD subtypes can be diagnosed based on liquid biopsies. CONCLUSIONS: We identified 3 FAD subtypes with unique clinical and biological characteristics, which could optimize individual cancer patient therapy and help clinical decision-making.


Assuntos
Carcinoma Hepatocelular , Quimioembolização Terapêutica , Neoplasias Hepáticas , Animais , Camundongos , Humanos , Carcinoma Hepatocelular/tratamento farmacológico , Carcinoma Hepatocelular/genética , Sorafenibe/uso terapêutico , Neoplasias Hepáticas/tratamento farmacológico , Neoplasias Hepáticas/genética , Multiômica , Medicina de Precisão , Ácidos Graxos , Microambiente Tumoral
5.
J Hepatol ; 2024 May 31.
Artigo em Inglês | MEDLINE | ID: mdl-38825017

RESUMO

BACKGROUND & AIMS: Crotonylation, a crotonyl-CoA-based non-enzymatic protein translational modification, affects diverse biological processes, such as spermatogenesis, tissue injury, inflammation, and neuropsychiatric diseases. Crotonylation shows decreased in hepatocellular carcinomas (HCCs), but the mechanism remains unknown. In this study, we aim to describe the role of glutaryl-CoA dehydrogenase (GCDH) in tumor suppression. METHODS: Three cohorts containing 40, 248 and 17 pairs of samples were used to evaluate the link between GCDH expression levels and the HCC clinical characteristics as well as anti-PD-1 response. Subcutaneous xenograft, orthotopic xenograft, Trp53Δhep/Δhep; MYC- as well as Ctnnboe; METoe- driven mouse models were adopted to validate GCDH effects on HCC suppression. RESULTS: GCDH depletion promoted HCC growth and metastasis, whereas its overexpression reversed these processes. As GCDH converts glutaryl-CoA to crotonyl-CoA to increase crotonylation levels, we performed lysine crotonylome analysis and identified the pentose phosphate pathway (PPP) and glycolysis-related proteins PGD, TKT, and ALDOC as GCDH-induced crotonylation targets. Crotonyl-bound targets showed allosteric effects that controlled their enzymatic activities, leading to decreases in ribose 5-phosphate and lactate production, further limiting the Warburg effect. PPP blockade also stimulated peroxidation, synergizing with senescent modulators to induce senescence in GCDHhigh cells. These cells induced the infiltration of immune cells by the senescence-associated secretory cell phenotype (SASP) to shape an anti-tumor immune microenvironment. Meanwhile, the GCDHlow population was sensitized to anti-programmed cell death protein 1 (PD-1) therapy. CONCLUSION: GCDH inhibits HCC progression via crotonylation-induced suppression of the PPP and glycolysis, resulting in HCC cell senescence. The senescent cell further shapes an anti-tumor microenvironment by SASP. The GCDHlow population is vulnerable to anti-PD-1 therapy because more PD-1+CD8+ T cells are exhibited in GCDHlow population. IMPACT AND IMPLICATIONS: GCDH is a favorable prognostic indicator in liver, lung, and renal cancers. In addition, most of GCDH depletion-induced toxic metabolites originate from the liver, accumulate locally, and cannot cross the blood-brain barrier. Therefore, studies on the correlation between GCDH and liver cancer would contribute to discovering the initiation and progression of hepatocellular carcinoma, of which over 70% of patients occupied >2-fold GCDH downregulation. Given that the GCDHlow and GCDHhigh HCC population can be distinguished based on serum glucose and ammonia levels, it will be worthwhile to evaluate the curative effects of pro-senescent and immune-therapeutic strategies based on the expression levels of GCDH.

6.
Small ; : e2312124, 2024 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-38751072

RESUMO

Rechargeable metal batteries have received widespread attention due to their high energy density by using pure metal as the anode. However, there are still many fundamental problems that need to be solved before approaching practical applications. The critical ones are low charge/discharge current due to slow ion transport, short cycle lifetime due to poor anode/cathode stability, and unsatisfied battery safety. To tackle these problems, various strategies have been suggested. Among them, electrolyte additive is one of the most widely used strategies. Most of the additives currently studied are soluble, but their reliability is questionable, and they can easily affect the electrochemical process, causing unwanted battery performance decline. On the contrary, insoluble additives with excellent chemical stability, high mechanical strength, and dimensional tunability have attracted considerable research exploration recently. However, there is no timely review on insoluble additives in metal batteries yet. This review summarizes various functions of insoluble additives: ion transport modulation, metal anode protection, cathode amelioration, as well as battery safety enhancement. Future research directions and challenges for insoluble solid additives are also proposed. It is expected this review will stimulate inspiration and arouse extensive studies on further improvement in the overall performance of metal batteries.

7.
BMC Cancer ; 24(1): 727, 2024 Jun 14.
Artigo em Inglês | MEDLINE | ID: mdl-38877445

RESUMO

BACKGROUND: The Naples Prognostic Score (NPS), integrating inflammatory and nutritional biomarkers, has been reported to be associated with the prognosis of various malignancies, but there is no report on intrahepatic cholangiocarcinoma (ICC). This study aimed to explore the prognostic value of NPS in patients with ICC. METHODS: Patients with ICC after hepatectomy were collected, and divided into three groups. The prognosis factors were determined by Cox regression analysis. Predictive efficacy was evaluated by the time-dependent receiver operating characteristic (ROC) curves. RESULTS: A total of 174 patients were included (Group 1: 33 (19.0%) patients; Group 2: 83 (47.7%) patients; and Group 3: 58 (33.3%) patients). The baseline characteristics showed the higher the NPS, the higher the proportion of patients with cirrhosis and Child-Pugh B, and more advanced tumors. The Kaplan-Meier curves reflect higher NPS were associated with poor survival. Multivariable analysis showed NPS was an independent risk factor of overall survival (NPS group 2 vs. 1: HR = 1.671, 95% CI: 1.022-3.027, p = 0.009; NPS group 3 vs. 1: HR = 2.208, 95% CI: 1.259-4.780, p = 0.007) and recurrence-free survival (NPS group 2 vs. 1: HR = 1.506, 95% CI: 1.184-3.498, p = 0.010; NPS group 3 vs. 1: HR = 2.141, 95% CI: 2.519-4.087, P = 0.001). The time ROC indicated NPS was superior to other models in predicting prognosis. CONCLUSIONS: NPS is a simple and effective tool for predicting the long-term survival of patients with ICC after hepatectomy. Patients with high NPS require close follow-up, and improving NPS may prolong the survival time.


Assuntos
Neoplasias dos Ductos Biliares , Colangiocarcinoma , Hepatectomia , Humanos , Colangiocarcinoma/cirurgia , Colangiocarcinoma/mortalidade , Colangiocarcinoma/patologia , Masculino , Feminino , Pessoa de Meia-Idade , Prognóstico , Neoplasias dos Ductos Biliares/cirurgia , Neoplasias dos Ductos Biliares/mortalidade , Neoplasias dos Ductos Biliares/patologia , Idoso , Curva ROC , Estudos Retrospectivos , Estimativa de Kaplan-Meier , Adulto , Fatores de Risco
8.
J Magn Reson Imaging ; 59(4): 1206-1217, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-37526043

RESUMO

BACKGROUND: Tertiary lymphoid structures (TLSs) are potential prognostic indicators. Radiomics may help reduce unnecessary invasive operations. PURPOSE: To analyze the association between TLSs and prognosis, and to establish a nomogram model to evaluate the expression of TLSs in breast cancer (BC) patients. STUDY TYPE: Retrospective. POPULATION: Two hundred forty-two patients with localized primary BC (confirmed by surgery) were divided into BC + TLS group (N = 122) and BC - TLS group (N = 120). FIELD STRENGTH/SEQUENCE: 3.0T; Caipirinha-Dixon-TWIST-volume interpolated breath-hold sequence for dynamic contrast-enhanced (DCE) MRI and inversion-recovery turbo spin echo sequence for T2-weighted imaging (T2WI). ASSESSMENT: Three models for differentiating BC + TLS and BC - TLS were developed: 1) a clinical model, 2) a radiomics signature model, and 3) a combined clinical and radiomics (nomogram) model. The overall survival (OS), distant metastasis-free survival (DMFS), and disease-free survival (DFS) were compared to evaluate the prognostic value of TLSs. STATISTICAL TESTS: LASSO algorithm and ANOVA were used to select highly correlated features. Clinical relevant variables were identified by multivariable logistic regression. Model performance was evaluated by the area under the receiver operating characteristic (ROC) curve (AUC), and through decision curve analysis (DCA). The Kaplan-Meier method was used to calculate the survival rate. RESULTS: The radiomics signature model (training: AUC 0.766; test: AUC 0.749) and the nomogram model (training: AUC 0.820; test: AUC 0.749) showed better validation performance than the clinical model. DCA showed that the nomogram model had a higher net benefit than the other models. The median follow-up time was 52 months. While there was no significant difference in 3-year OS (P = 0.22) between BC + TLS and BC - TLS patients, there were significant differences in 3-year DFS and 3-year DMFS between the two groups. DATA CONCLUSION: The nomogram model performs well in distinguishing the presence or absence of TLS. BC + TLS patients had higher long-term disease control rates and better prognoses than those without TLS. EVIDENCE LEVEL: 2 TECHNICAL EFFICACY: Stage 2.


Assuntos
Neoplasias da Mama , Estruturas Linfoides Terciárias , Humanos , Feminino , Prognóstico , Neoplasias da Mama/diagnóstico por imagem , Radiômica , Estudos Retrospectivos , Imageamento por Ressonância Magnética
9.
Eur J Clin Microbiol Infect Dis ; 43(4): 735-745, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38361135

RESUMO

PURPOSE: This article aims to establish a rapid visual method for the detection of Streptococcus pyogenes (GAS) based on recombinase polymerase amplification (RPA) and lateral flow strip (LFS). METHODS: Utilizing speB of GAS as a template, RPA primers were designed, and basic RPA reactions were performed. To reduce the formation of primer dimers, base mismatch was introduced into primers. The probe was designed according to the forward primer, and the RPA-LFS system was established. According to the color results of the reaction system, the optimum reaction temperature and time were determined. Thirteen common clinical standard strains and 14 clinical samples of GAS were used to detect the selectivity of this method. The detection limit of this method was detected by using tenfold gradient dilution of GAS genome as template. One hundred fifty-six clinical samples were collected and compared with qPCR method and culture method. Kappa index and clinical application evaluation of the RPA-LFS were carried out. RESULTS: The enhanced RPA-LFS method demonstrates the ability to complete the amplification process within 6 min at 33 °C. This method exhibits a high analytic sensitivity, with the lowest detection limit of 0.908 ng, and does not exhibit cross-reaction with other pathogenic bacteria. CONCLUSIONS: The utilization of RPA and LFS allows for efficient and rapid testing of GAS, thereby serving as a valuable method for point-of-care testing.


Assuntos
Recombinases , Streptococcus pyogenes , Humanos , Streptococcus pyogenes/genética , Sensibilidade e Especificidade , Temperatura , Técnicas de Amplificação de Ácido Nucleico/métodos
10.
Nature ; 563(7729): 131-136, 2018 11.
Artigo em Inglês | MEDLINE | ID: mdl-30356214

RESUMO

Accurate repair of DNA double-stranded breaks by homologous recombination preserves genome integrity and inhibits tumorigenesis. Cyclic GMP-AMP synthase (cGAS) is a cytosolic DNA sensor that activates innate immunity by initiating the STING-IRF3-type I IFN signalling cascade1,2. Recognition of ruptured micronuclei by cGAS links genome instability to the innate immune response3,4, but the potential involvement of cGAS in DNA repair remains unknown. Here we demonstrate that cGAS inhibits homologous recombination in mouse and human models. DNA damage induces nuclear translocation of cGAS in a manner that is dependent on importin-α, and the phosphorylation of cGAS at tyrosine 215-mediated by B-lymphoid tyrosine kinase-facilitates the cytosolic retention of cGAS. In the nucleus, cGAS is recruited to double-stranded breaks and interacts with PARP1 via poly(ADP-ribose). The cGAS-PARP1 interaction impedes the formation of the PARP1-Timeless complex, and thereby suppresses homologous recombination. We show that knockdown of cGAS suppresses DNA damage and inhibits tumour growth both in vitro and in vivo. We conclude that nuclear cGAS suppresses homologous-recombination-mediated repair and promotes tumour growth, and that cGAS therefore represents a potential target for cancer prevention and therapy.


Assuntos
Núcleo Celular/metabolismo , Transformação Celular Neoplásica/patologia , Neoplasias/metabolismo , Neoplasias/patologia , Nucleotidiltransferases/metabolismo , Reparo de DNA por Recombinação , Transporte Ativo do Núcleo Celular , Adulto , Animais , Proteínas de Ciclo Celular/antagonistas & inibidores , Proteínas de Ciclo Celular/metabolismo , Linhagem Celular Tumoral , Núcleo Celular/enzimologia , Quebras de DNA de Cadeia Dupla , Dano ao DNA , Feminino , Células HEK293 , Humanos , Peptídeos e Proteínas de Sinalização Intracelular/antagonistas & inibidores , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Masculino , Proteínas de Membrana/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Proteínas de Neoplasias/metabolismo , Neoplasias/genética , Nucleotidiltransferases/deficiência , Fosforilação , Ftalazinas/farmacologia , Piperazinas/farmacologia , Poli(ADP-Ribose) Polimerase-1/antagonistas & inibidores , Poli(ADP-Ribose) Polimerase-1/metabolismo , Ligação Proteica/efeitos dos fármacos , Reparo de DNA por Recombinação/genética , Quinases da Família src/metabolismo
11.
Int J Neurosci ; : 1-8, 2024 Feb 22.
Artigo em Inglês | MEDLINE | ID: mdl-38372675

RESUMO

OBJECTIVE: The objective was to explore the possible relationship between the serum vitamin D level and olfactory impairment in a population of multiple sclerosis (MS) patients in Guizhou, China. METHODS: We included 25 patients with MS and 18 healthy controls (HCs) who were recruited from the Affiliated Hospital of Guizhou Medical University from February 2021 to September 2021. The University of Pennsylvania Smell Identification Test (UPSIT) was used to test the patients' sense of smell, and the level of serum 25-hydroxyethylene polyprotein D was measured. RESULTS: Serum vitamin D levels and UPSIT scores were significantly different between the MS group and the control group (both p < 0.001). Moreover, a significant positive correlation emerged between vitamin D levels and UPSIT scores in MS patients (r = 0.537, p = 0.021). CONCLUSIONS: The serum vitamin D level may be involved in the regulation of olfactory dysfunction in MS patients in Guizhou, China.


Multiple sclerosis is a rare disease in China.Compared with that of healthy controls, the olfactory function of MS patients was severely impaired.Compared with healthy controls, MS patients had low vitamin D levels.A significant positive correlation emerged between vitamin D levels and UPSIT scores in MS patients.The vitamin D levels of MS patients may be associated with olfactory impairment, which may have implications for future mechanistic studies.

12.
Small ; 19(33): e2300964, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-37066740

RESUMO

The long-range magnetic ordering in frustrated magnetic systems is stabilized by coupling magnetic moments to various degrees of freedom, for example, by enhancing magnetic anisotropy via lattice distortion. Here, the unconventional spin-lattice coupled metamagnetic properties of atomically-thin CrOCl, a van der Waals antiferromagnet with inherent magnetic frustration rooted in the staggered square lattice, are reported. Using temperature- and angle-dependent tunneling magnetoconductance (TMC), in complementary with magnetic torque and first-principles calculations, the antiferromagnetic (AFM)-to-ferrimagnetic (FiM) metamagnetic transitions (MTs) of few-layer CrOCl are revealed to be triggered by collective magnetic moment flipping rather than the established spin-flop mechanism, when external magnetic field (H) enforces a lattice reconstruction interlocked with the five-fold periodicity of the FiM phase. The spin-lattice coupled MTs are manifested by drastic jumps in TMC, which show anomalous upshifts at the transition thresholds and persist much higher above the AFM Néel temperature. While the MTs exhibit distinctive triaxial anisotropy, reflecting divergent magnetocrystalline anisotropy of the c-axis AFM ground state, the resulting FiM phase has an a-c easy plane in which the magnetization axis is freely rotated by H. At the 2D limit, such a field-tunable FiM phase may provide unique opportunities to explore exotic emergent phenomena and novel spintronics devices.

13.
Small ; 19(23): e2207093, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-36890773

RESUMO

Lithium metal batteries (LMBs) are promising for next-generation high-energy-density batteries owing to the highest specific capacity and the lowest potential of Li metal anode. However, the LMBs are normally confronted with drastic capacity fading under extremely cold conditions mainly due to the freezing issue and sluggish Li+ desolvation process in commercial ethylene carbonate (EC)-based electrolyte at ultra-low temperature (e.g., below -30 °C). To overcome the above challenges, an anti-freezing carboxylic ester of methyl propionate (MP)-based electrolyte with weak Li+ coordination and low-freezing temperature (below -60 °C) is designed, and the corresponding LiNi0.8 Co0.1 Mn0.1 O2 (NCM811) cathode exhibits a higher discharge capacity of 84.2 mAh g-1 and energy density of 195.0 Wh kg-1 cathode than that of the cathode (1.6 mAh g-1 and 3.9 Wh kg-1 cathode ) working in commercial EC-based electrolytes for NCM811‖ Li cell at -60 °C. Molecular dynamics simulation, Raman spectra, and nuclear magnetic resonance characterizations reveal that rich mobile Li+ and the unique solvation structure with weak Li+ coordination are achieved in MP-based electrolyte, which collectively facilitate the Li+ transference process at low temperature. This work provides fundamental insights into low-temperature electrolytes by regulating solvation structure, and offers the basic guidelines for the design of low-temperature electrolytes for LMBs.

14.
Opt Lett ; 47(19): 4845-4848, 2022 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-36181132

RESUMO

An optical attenuator is an optical device that can modulate the power level of an optical signal. Based on the macro-bending loss of optical fibers, we present a wavy fiber attenuator where the attenuation level can be controlled by a mechanical-induced buckling of the fiber. By bonding a fiber to a prestretched substrate and then releasing the prestrain, the fiber flexes into a sinusoidal wavy curve due to the constraints of the substrate. The level of the light attenuation can simply be controlled by stretching the substrate. The maximum attenuation of the proposed wavy optical fiber attenuator is -87.3 dB.

15.
Nucleic Acids Res ; 48(16): 9181-9194, 2020 09 18.
Artigo em Inglês | MEDLINE | ID: mdl-32789493

RESUMO

The NAD+-dependent deacetylase and mono-ADP-ribosyl transferase SIRT6 stabilizes the genome by promoting DNA double strand break repair, thereby acting as a tumor suppressor. However, whether SIRT6 regulates nucleotide excision repair (NER) remains unknown. Here, we showed that SIRT6 was recruited to sites of UV-induced DNA damage and stimulated the repair of UV-induced DNA damage. Mechanistic studies further indicated that SIRT6 interacted with DDB2, the major sensor initiating global genome NER (GG-NER), and that the interaction was enhanced upon UV irradiation. SIRT6 deacetylated DDB2 at two lysine residues, K35 and K77, upon UV stress and then promoted DDB2 ubiquitination and segregation from chromatin, thereby facilitating downstream signaling. In addition, we characterized several SIRT6 mutations derived from melanoma patients. These SIRT6 mutants ablated the stimulatory effect of SIRT6 on NER and destabilized the genome due to (i) partial loss of enzymatic activity (P27S or H50Y), (ii) a nonsense mutation (R150*) or (iii) high turnover rates (G134W). Overall, we demonstrate that SIRT6 promotes NER by deacetylating DDB2, thereby preventing the onset of melanomagenesis.


Assuntos
Carcinogênese/genética , Dano ao DNA/genética , Proteínas de Ligação a DNA/genética , Melanoma/genética , Sirtuínas/genética , Carcinogênese/efeitos da radiação , Cromatina/genética , Cromatina/efeitos da radiação , Dano ao DNA/efeitos da radiação , Reparo do DNA/efeitos da radiação , Regulação da Expressão Gênica/efeitos da radiação , Células HeLa , Humanos , Melanoma/patologia , Mutação/efeitos da radiação , Ubiquitinação/efeitos da radiação , Raios Ultravioleta/efeitos adversos
17.
Sheng Li Xue Bao ; 74(2): 294-300, 2022 Apr 25.
Artigo em Zh | MEDLINE | ID: mdl-35503077

RESUMO

How the brain perceives objects and classifies perceived objects is one of the important goals of visual cognitive neuroscience. Previous research has shown that when we see objects, the brain's ventral visual pathway recognizes and classifies them, leading to different ways of interacting with them. In this paper, we summarize the latest research progress of the ventral visual pathway related to the visual classification of objects. From the perspective of the neural representation of objects and its underlying mechanisms in the visual cortex, we summarize the current research status of the two important organizational dimensions of object animacy and real-world size, provide new insights, and point out the direction of further research.


Assuntos
Córtex Visual , Vias Visuais , Mapeamento Encefálico/métodos , Imageamento por Ressonância Magnética , Reconhecimento Visual de Modelos , Estimulação Luminosa
18.
J Cell Physiol ; 236(11): 7298-7307, 2021 11.
Artigo em Inglês | MEDLINE | ID: mdl-33870507

RESUMO

Osteoarthritis (OA) is a multifactorial and chronic disease describing the destruction of cartilage that can lead to defects in the elderly. There is currently no practical strategy that can reverse the OA process. Here, we describe nepetin, a small natural compound with extracellular matrix (ECM) and inflammation regulating functions. In this study, we investigated the therapeutic effects of nepetin on interleukin-1ß (IL-1ß)-induced inflammation in mice chondrocyte and OA model. In chondrocytes, treatment with nepetin inhibited the overexpression of pro-inflammatory cytokines and mediators induced by IL-1ß. Moreover, pretreatment or posttreatment with nepetin also reduced the ECM catabolism and enhanced the ECM anabolism. Mechanistically, nepetin suppressed NF-κB signaling pathway in IL-1ß stimulated chondrocyte. Meanwhile, our molecular docking studies indicated nepetin had a powerful binding capacity to p65. Furthermore, nepetin showed a protective and therapeutic effect on the mouse OA model. To sum up, this study indicated nepetin had a new potential therapeutic option in OA.


Assuntos
Antirreumáticos/farmacologia , Condrócitos/efeitos dos fármacos , Flavonas/farmacologia , Articulações/efeitos dos fármacos , NF-kappa B/antagonistas & inibidores , Osteoartrite/tratamento farmacológico , Animais , Células Cultivadas , Condrócitos/metabolismo , Condrócitos/patologia , Modelos Animais de Doenças , Matriz Extracelular/efeitos dos fármacos , Matriz Extracelular/metabolismo , Matriz Extracelular/patologia , Feminino , Interleucina-1beta/toxicidade , Articulações/metabolismo , Articulações/patologia , Masculino , Camundongos Endogâmicos C57BL , Simulação de Acoplamento Molecular , NF-kappa B/metabolismo , Osteoartrite/metabolismo , Osteoartrite/patologia , Pirrolidinas/farmacologia , Transdução de Sinais , Tiocarbamatos/farmacologia , Fator de Transcrição RelA/metabolismo
19.
Small ; 17(43): e2103679, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-34580989

RESUMO

As one of the most efficient electrochemical energy storage devices, the energy density of lithium-ion batteries (LIBs) has been extensively improved in the past several decades. However, with increased energy density, the safety risk of LIBs becomes higher too. The frequently occurred battery accidents worldwide remind us that safeness is a crucial requirement for LIBs, especially in environments with high safety concerns like airplanes and military platforms. It is generally recognized that the catastrophic thermal runaway (TR) event is the major cause of LIBs related accidents. Tremendous efforts have been devoted to coping with the TR concerns in LIBs, and thus enhance battery safety. This review first gives an introduction to the fundamentals of LIBs and the origins of safety issues. Then, the authors summarize the recent advances to improve the safety of LIBs with a unique focus on thermal-responsive and fire-resistant materials. Finally, a perspective is proposed to guide future research directions in this field. It is anticipated this review will stimulate inspiration and arouse extensive studies on further improvement in battery safety.


Assuntos
Fontes de Energia Elétrica , Lítio , Íons
20.
Opt Lett ; 46(19): 4825-4827, 2021 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-34598209

RESUMO

We present a spectrum-tunable fiber Bragg grating (FBG) based on a unique compress-twist deformation mode of non-rigid origami. By applying axial displacement on the FBG-bonded Kresling-ori, a non-uniform strain field emerges. The mechanics-induced non-uniform strain can shift the wavelength of an apodized unchirped FBG and/or transform an apodized unchirped FBG to a chirped one. For the spectrum-shaping mode, the bandwidth of the FBG was tuned from 0.32 nm up to 2.9 nm, measured at the -6dB level. For the wavelength-shift mode, a maximum wavelength shift of 0.6 nm can be achieved.

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