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1.
Cell ; 164(3): 564-78, 2016 Jan 28.
Artigo em Inglês | MEDLINE | ID: mdl-26824662

RESUMO

Type 1 interferon (IFN) is a key mediator of organismal responses to pathogens, eliciting prototypical "interferon signature genes" that encode antiviral and inflammatory mediators. For a global view of IFN signatures and regulatory pathways, we performed gene expression and chromatin analyses of the IFN-induced response across a range of immunocyte lineages. These distinguished ISGs by cell-type specificity, kinetics, and sensitivity to tonic IFN and revealed underlying changes in chromatin configuration. We combined 1,398 human and mouse datasets to computationally infer ISG modules and their regulators, validated by genetic analysis in both species. Some ISGs are controlled by Stat1/2 and Irf9 and the ISRE DNA motif, but others appeared dependent on non-canonical factors. This regulatory framework helped to interpret JAK1 blockade pharmacology, different clusters being affected under tonic or IFN-stimulated conditions, and the IFN signatures previously associated with human diseases, revealing unrecognized subtleties in disease footprints, as affected by human ancestry.


Assuntos
Redes Reguladoras de Genes , Interferon Tipo I/imunologia , Interferon Tipo I/metabolismo , Animais , Linfócitos T CD4-Positivos/metabolismo , Conjuntos de Dados como Assunto , Humanos , Janus Quinases/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Receptor de Interferon alfa e beta/metabolismo
2.
Cell ; 161(4): 762-73, 2015 May 07.
Artigo em Inglês | MEDLINE | ID: mdl-25957684

RESUMO

Transcription through immunoglobulin switch (S) regions is essential for class switch recombination (CSR), but no molecular function of the transcripts has been described. Likewise, recruitment of activation-induced cytidine deaminase (AID) to S regions is critical for CSR; however, the underlying mechanism has not been fully elucidated. Here, we demonstrate that intronic switch RNA acts in trans to target AID to S region DNA. AID binds directly to switch RNA through G-quadruplexes formed by the RNA molecules. Disruption of this interaction by mutation of a key residue in the putative RNA-binding domain of AID impairs recruitment of AID to S region DNA, thereby abolishing CSR. Additionally, inhibition of RNA lariat processing leads to loss of AID localization to S regions and compromises CSR; both defects can be rescued by exogenous expression of switch transcripts in a sequence-specific manner. These studies uncover an RNA-mediated mechanism of targeting AID to DNA.


Assuntos
Citidina Desaminase/metabolismo , Switching de Imunoglobulina , RNA Guia de Cinetoplastídeos/metabolismo , Animais , Quadruplex G , Íntrons , Proteínas Ligantes de Maltose/metabolismo , Camundongos , Processamento Pós-Transcricional do RNA , RNA Guia de Cinetoplastídeos/genética
3.
Nano Lett ; 24(18): 5631-5638, 2024 May 08.
Artigo em Inglês | MEDLINE | ID: mdl-38669049

RESUMO

Perovskite light-emitting diodes (PeLEDs) based on CsPb(Br/I)3 nanocrystals (NCs) usually suffer from severe spectral instability under operating voltage due to the poor-quality PeNCs. Herein, zeolite was utilized to prepare high-quality CsPb(Br/I)3 NCs via promoting the homogeneous nucleation and growth and suppressing the Ostwald ripening of PeNCs. In addition, the decomposed zeolite interacted strongly with PeNCs through Pb-O bonds and hydrogen bonds, which inhibited the formation of defects and suppressed halide ion migration, leading to an improved photoluminescence quantum yield (PLQY) and enhanced stability of PeNCs. Moreover, the strong binding affinity of decomposed zeolite to PeNCs contributed to the formation of homogeneous perovskite films with high PLQY. As a result, pure-red PeLEDs with Commission International de I'Eclairage (CIE) coordinates of (0.705, 0.291) were fabricated, approaching the Rec. 2020 red primary color. The devices achieved a peak external quantum efficiency of 23.0% and outstanding spectral stability.

4.
Small ; : e2309026, 2024 Mar 13.
Artigo em Inglês | MEDLINE | ID: mdl-38477698

RESUMO

Hypoxic tumor microenvironment (TME) hampers the application of oxygen (O2 )-dependent photodynamic therapy (PDT) in solid tumors. To address this problem, a biomimetic nanotheranostics (named MMCC@EM) is developed for optical molecular imaging-escorted self-oxygenation PDT. MMCC@EM is synthesized by encapsulating chlorin e6 (Ce6) and catalase (CAT) in metal-organic framework (MOF) nanoparticles with erythrocyte membrane (EM) camouflage. Based on the biomimetic properties of EM, MMCC@EM efficiently accumulates in tumor tissues. The enriched MMCC@EM achieves TME-activatable drug release, thereby releasing CAT and Ce6, and this process can be monitored through fluorescence (FL) imaging. In addition, endogenous hydrogen peroxide (H2 O2 ) will be decomposed by CAT to produce O2 , which can be reflected by the measurement of intratumoral oxygen concentration using photoacoustic (PA) imaging. Such self-oxygenation nanotheranostics effectively mitigate tumor hypoxia and improve the generation of singlet oxygen (1 O2 ). The 1 O2 disrupts mitochondrial function and triggers caspase-3-mediated cellular apoptosis. Furthermore, MMCC@EM triggers immunogenic cell death (ICD) effect, leading to an increased infiltration of cytotoxic T lymphocytes (CTLs) into tumor tissues. As a result, MMCC@EM exhibits good therapeutic effects in 4T1-tumor bearing mice under the navigation of FL/PA duplex imaging.

5.
Opt Express ; 32(3): 4684-4697, 2024 Jan 29.
Artigo em Inglês | MEDLINE | ID: mdl-38297663

RESUMO

On-chip Bragg gratings with high reflectivities have been found to have widespread applications in filters, resonators, and semiconductor lasers. However, achieving strong Bragg reflections with flat response across a broad bandwidth on the popular 220 nm silicon-on-insulator (SOI) platform still remains a challenge. In this paper, such a high performance device is proposed and fabricated, which is based on a slot waveguide with gratings etched on the inner sidewalls of the slot. By manipulating the local field in the slot region using a chirped and tapered grating-based mode transition, the device achieves a flat response with ultra-high reflection and low transmission for the TE mode across a broad operating bandwidth. Leveraging the ultra-high birefringence of the SOI waveguide, the device functions both as a TE slot waveguide reflector and a TM pass polarizer. Simulation results demonstrate that the device exhibits an ultra-high rejection of more than 50 dB and a reflectivity exceeding 0.99 for the TE mode across a 91 nm wavelength range, while maintaining a high transmittance of larger than 0.98 for the TM mode. Experimental results validate that the device performance is consistent with the simulation results. A fabricated device based on such a gratings exhibits a low insertion loss (<0.8 dB) and high polarization extinction ratio (>30 dB) over 100 nm bandwidth (1484 nm-1584 nm), demonstrating that the performance of the present design is competitive with that of the state-of-the-art SOI Bragg gratings.

6.
Opt Express ; 32(7): 12172-12180, 2024 Mar 25.
Artigo em Inglês | MEDLINE | ID: mdl-38571048

RESUMO

A narrow-linewidth and low relative intensity noise (RIN) Tm/Ho co-doped fiber laser based on a saturable absorber and self-injection locking was demonstrated for the first time. Utilizing self-injection locking technology, the frequency noise power spectral density is remarkably reduced by more than 17.1 dB from 1.21 × 106 Hz2/Hz to 7.30 × 103 Hz2/Hz when the frequency is approximately 1 kHz. Furthermore, a laser with a linewidth compressed to a quarter of the original linewidth from 44.386 kHz to 2.850 kHz, a RIN of less than -127.74 dB/Hz, and an optical signal-to-noise ratio of more than 71.6 dB can be obtained. Using a delay fiber, the relaxation oscillation peak frequencies move to lower frequencies, from 27.9 kHz to 15.8 kHz. The proposed laser is highly competitive in advanced coherent light detection fields, including coherent Doppler wind lidar, high-speed coherent optical communication, and precise absolute distance coherent measurement.

7.
Acta Pharmacol Sin ; 45(2): 391-404, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-37803139

RESUMO

Hepatocellular carcinoma (HCC) is one of the most common and deadly cancers in the world. The therapeutic outlook for HCC patients has significantly improved with the advent and development of systematic and targeted therapies such as sorafenib and lenvatinib; however, the rise of drug resistance and the high mortality rate necessitate the continuous discovery of effective targeting agents. To discover novel anti-HCC compounds, we first constructed a deep learning-based chemical representation model to screen more than 6 million compounds in the ZINC15 drug-like library. We successfully identified LGOd1 as a novel anticancer agent with a characteristic levoglucosenone (LGO) scaffold. The mechanistic studies revealed that LGOd1 treatment leads to HCC cell death by interfering with cellular copper homeostasis, which is similar to a recently reported copper-dependent cell death named cuproptosis. While the prototypical cuproptosis is brought on by copper ionophore-induced copper overload, mechanistic studies indicated that LGOd1 does not act as a copper ionophore, but most likely by interacting with the copper chaperone protein CCS, thus LGOd1 represents a potentially new class of compounds with unique cuproptosis-inducing property. In summary, our findings highlight the critical role of bioavailable copper in the regulation of cell death and represent a novel route of cuproptosis induction.


Assuntos
Carcinoma Hepatocelular , Aprendizado Profundo , Neoplasias Hepáticas , Humanos , Carcinoma Hepatocelular/tratamento farmacológico , Cobre , Neoplasias Hepáticas/tratamento farmacológico , Ionóforos , Apoptose
8.
Acta Pharmacol Sin ; 2024 May 08.
Artigo em Inglês | MEDLINE | ID: mdl-38719954

RESUMO

Hypertensive cerebrovascular remodeling involves the enlargement of vascular smooth muscle cells (VSMCs), which activates volume-regulated Cl- channels (VRCCs). The leucine-rich repeat-containing family 8 A (LRRC8A) has been shown to be the molecular identity of VRCCs. However, its role in vascular remodeling during hypertension is unclear. In this study, we used vascular smooth muscle-specific LRRC8A knockout (CKO) mice and an angiotensin II (Ang II)-induced hypertension model. The results showed that cerebrovascular remodeling during hypertension was ameliorated in CKO mice, and extracellular matrix (ECM) deposition was reduced. Based on the RNA-sequencing analysis of aortic tissues, the level of matrix metalloproteinases (MMPs), such as MMP-9 and MMP-14, were reduced in CKO mice with hypertension, which was further verified in vivo by qPCR and immunofluorescence analysis. Knockdown of LRRC8A in VSMCs inhibited the Ang II-induced upregulation of collagen I, fibronectin, and matrix metalloproteinases (MMPs), and overexpression of LRRC8A had the opposite effect. Further experiments revealed an interaction between with-no-lysine (K)-1 (WNK1), which is a "Cl--sensitive kinase", and Forkhead transcription factor O3a (FOXO3a), which is a transcription factor that regulates MMP expression. Ang II induced the phosphorylation of WNK1 and downstream FOXO3a, which then increased the expression of MMP-2 and MMP-9. This process was inhibited or potentiated when LRRC8A was knocked down or overexpressed, respectively. Overall, these results demonstrate that LRRC8A knockout in vascular smooth muscle protects against cerebrovascular remodeling during hypertension by reducing ECM deposition and inhibiting the WNK1/FOXO3a/MMP signaling pathway, demonstrating that LRRC8A is a potential therapeutic target for vascular remodeling-associated diseases such as stroke.

9.
Mar Drugs ; 22(6)2024 May 26.
Artigo em Inglês | MEDLINE | ID: mdl-38921552

RESUMO

Developing novel, safe, and efficient proangiogenic drugs is an important approach for the prevention and treatment of cardiovascular diseases. In this study, 4 new compounds, including 3 azaphilones (1-3) and 1 dihydroisocoumarin (4), as well as 13 known compounds (5-17), were isolated from the sea-mud-derived fungus Neopestalotiopsis sp. HN-1-6 from the Beibu Gulf of China. The structures of the new compounds were determined by NMR, MS, ECD, and NMR calculations. Compounds 3, 5, and 7 exhibited noteworthy proangiogenic activities in a zebrafish model at a concentration of 40 µM, without displaying cytotoxicity toward five human cell lines. In addition, some compounds demonstrated antibacterial effects against Staphylococcus aureus, Escherichia coli, and Candida albicans, with MIC values ranging from 64 µg/mL to 256 µg/mL.


Assuntos
Antibacterianos , Benzopiranos , Testes de Sensibilidade Microbiana , Pigmentos Biológicos , Peixe-Zebra , Animais , Benzopiranos/farmacologia , Benzopiranos/química , Benzopiranos/isolamento & purificação , Humanos , Antibacterianos/farmacologia , Antibacterianos/isolamento & purificação , Antibacterianos/química , Pigmentos Biológicos/farmacologia , Pigmentos Biológicos/isolamento & purificação , Pigmentos Biológicos/química , Staphylococcus aureus/efeitos dos fármacos , Candida albicans/efeitos dos fármacos , Organismos Aquáticos , Escherichia coli/efeitos dos fármacos , China , Linhagem Celular
10.
Mar Drugs ; 22(6)2024 May 27.
Artigo em Inglês | MEDLINE | ID: mdl-38921554

RESUMO

Five new naphthalene derivatives dalesconosides A-D, F (1-4, 6), a known synthetic analogue named dalesconoside E (5), and eighteen known compounds (7-24) were isolated from Daldinia eschscholzii MCZ-18, which is an endophytic fungus obtained from the Chinese mangrove plant Ceriops tagal. Differing from previously reported naphthalenes, compounds 1 and 2 were bearing a rare ribofuranoside substituted at C-1 and the 5-methyltetrahydrofuran-2,3-diol moiety, respectively. Their structures were determined by detailed nuclear magnetic resonance (NMR) and mass spectroscopic (MS) analyses, while the absolute configurations were established by theoretical electronic circular dichroism (ECD) calculation. Compounds 1, 3, 13-17 and 19 showed broad ranges of antimicrobial spectrum against five indicator test microorganisms (Enterococcus faecalis, Methicillin-resistant Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa and Candida albicans); especially, 1, 16 and 17 were most potent. The variations in structure and attendant biological activities provided fresh insights concerning structure-activity relationships for the naphthalene derivatives.


Assuntos
Testes de Sensibilidade Microbiana , Naftalenos , Naftalenos/farmacologia , Naftalenos/química , Naftalenos/isolamento & purificação , Relação Estrutura-Atividade , Espectroscopia de Ressonância Magnética , Antibacterianos/farmacologia , Antibacterianos/química , Antibacterianos/isolamento & purificação , Candida albicans/efeitos dos fármacos , Estrutura Molecular , Rhizophoraceae/microbiologia , Endófitos/química , Anti-Infecciosos/farmacologia , Anti-Infecciosos/química , Anti-Infecciosos/isolamento & purificação
11.
Mar Drugs ; 22(6)2024 Jun 14.
Artigo em Inglês | MEDLINE | ID: mdl-38921589

RESUMO

Overwhelming evidence points to an aberrant Wnt/ß-catenin signaling as a critical factor in hepatocellular carcinoma (HCC) and cervical cancer (CC) pathogenesis. Dicerandrol C (DD-9), a dimeric tetrahydroxanthenone isolated from the endophytic fungus Phomopsis asparagi DHS-48 obtained from mangrove plant Rhizophora mangle via chemical epigenetic manipulation of the culture, has demonstrated effective anti-tumor properties, with an obscure action mechanism. The objective of the current study was to explore the efficacy of DD-9 on HepG2 and HeLa cancer cells and its functional mechanism amid the Wnt/ß catenin signaling cascade. Isolation of DD-9 was carried out using various column chromatographic methods, and its structure was elucidated with 1D NMR. The cytotoxicity of DD-9 on HepG2 and HeLa cells was observed with respect to the proliferation, clonality, migration, invasion, apoptosis, cell cycle, and Wnt/ß-catenin signaling cascade. We found that DD-9 treatment significantly reduced tumor cell proliferation in dose- and time-dependent manners in HepG2 and HeLa cells. The subsequent experiments in vitro implied that DD-63 could significantly suppress the tumor clonality, metastases, and induced apoptosis, and that it arrested the cell cycle at the G0/G1 phase of HepG2 and HeLa cells. Dual luciferase assay, Western blot, and immunofluorescence assay showed that DD-9 could dose-dependently attenuate the Wnt/ß-catenin signaling by inhibiting ß-catenin transcriptional activity and abrogating ß-catenin translocated to the nucleus; down-regulating the transcription level of ß-catenin-stimulated Wnt target gene and the expression of related proteins including p-GSK3-ß, ß-catenin, LEF1, Axin1, c-Myc, and CyclinD1; and up-regulating GSK3-ß expression, which indicates that DD-9 stabilized the ß-catenin degradation complex, thereby inducing ß-catenin degradation and inactivation of the Wnt/ß-catenin pathway. The possible interaction between DD-9 and ß-catenin and GSK3-ß protein was further confirmed by molecular docking studies. Collectively, DD-9 may suppress proliferation and induce apoptosis of liver and cervical cancer cells, possibly at least in part via GSK3-ß-mediated crosstalk with the Wnt/ß-catenin signaling axis, providing insights into the mechanism for the potency of DD-9 on hepatocellular and cervical cancer.


Assuntos
Apoptose , Proliferação de Células , Via de Sinalização Wnt , Humanos , Células HeLa , Apoptose/efeitos dos fármacos , Via de Sinalização Wnt/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Células Hep G2 , beta Catenina/metabolismo , Antineoplásicos/farmacologia , Antineoplásicos/química , Antineoplásicos/isolamento & purificação , Neoplasias Hepáticas/tratamento farmacológico , Xantonas/farmacologia , Xantonas/química , Xantonas/isolamento & purificação , Carcinoma Hepatocelular/tratamento farmacológico , Carcinoma Hepatocelular/patologia , Movimento Celular/efeitos dos fármacos , Neoplasias do Colo do Útero/tratamento farmacológico , Neoplasias do Colo do Útero/patologia
12.
Mar Drugs ; 22(3)2024 Feb 23.
Artigo em Inglês | MEDLINE | ID: mdl-38535443

RESUMO

The co-culture strategy, which mimics natural ecology by constructing an artificial microbial community, is a useful tool for the activation of biosynthetic gene clusters (BGCs) to generate new metabolites, as well as to increase the yield of respective target metabolites. As part of our project aiming at the discovery of structurally novel and biologically active natural products from mangrove endophytic fungi, we selected the co-culture of a strain of Phomopsis asparagi DHS-48 with another Phomopsis genus fungus DHS-11, both endophyted in mangrove Rhizophora mangle considering the impart of the taxonomic criteria and ecological data. The competition interaction of the two strains was investigated through morphology observation and scanning electron microscopy (SEM), and it was found that the mycelia of the DHS-48 and DHS-11 compacted and tangled with each other with an interwoven pattern in the co-culture system. A new approach that integrates HPLC chromatogram, 1HNMR spectroscopy, UPLC-MS-PCA, and molecular networking enabled the targeted isolation of the induced metabolites, including three new dimeric xanthones phomoxanthones L-N (1-3), along with six known analogs (4-9). Their planar structures were elucidated by an analysis of their HRMS, MS/MS, and NMR spectroscopic data and the absolute configurations based on ECD calculations. These metabolites showed broad cytotoxic activity against the cancer cells assessed, of which compounds 7-9 displayed significant cytotoxicity towards human liver cells HepG-2 with IC50 values ranging from 4.83 µM to 12.06 µM. Compounds 1-6 exhibited weak immunosuppressive activity against the proliferation of ConA-induced (T-cell) and LPS-induced (B-cell) murine splenic lymphocytes. Therefore, combining co-cultivation with a metabolomics-guided strategy as a discovery tool will be implemented as a systematic strategy for the quick discovery of target bioactive compounds.


Assuntos
Phomopsis , Espectrometria de Massas em Tandem , Humanos , Animais , Camundongos , Cromatografia Líquida , Técnicas de Cocultura , Fungos
13.
Arch Gynecol Obstet ; 309(2): 689-697, 2024 02.
Artigo em Inglês | MEDLINE | ID: mdl-38051371

RESUMO

PURPOSE: The proportion of patients with poor ovarian response (POR) is increasing, but effective treatment remains a challenge. To control the hidden peaks of luteinizing hormone (LH) and premature ovulation for poor responders, this study investigated the efficacy of flexible short protocol (FSP) with gonadotropin-releasing hormone antagonist (GnRH-ant) on trigger day. METHODS: The 662 cycles of POR patients were retrospectively analyzed. The cohort was divided into control and intervention groups. The intervention group (group A) with 169 cycles received a GnRH-ant given on trigger day. The control (group B) with 493 cycles received only FSP. The clinical outcomes of the two groups were compared. RESULTS: Compared with group B, with gonadotropin-releasing hormone antagonist (GnRH-ant) on trigger day in group A the incidences of spontaneous premature ovulation decreased significantly (2.37% vs. 8.72%, P < 0.05). The number of fresh embryo-transfer cycles was 45 in group A and 117 in group B. There were no significant differences in clinical outcomes, including implantation rate, clinical pregnancy rate, live birth rate and the cumulative live birth rate (12.0% vs. 9.34%; 22.22% vs. 21.93%; 17.78% vs. 14.91%; 20.51% vs. 20%, respectively; P > 0.05) between the two group. CONCLUSION: FSP with GnRH-ant addition on trigger day had no effect on clinical outcomes, but could effectively inhibit the hidden peaks of luteinizing hormone (LH) and spontaneous premature ovulation in POR. Therefore, it is an advantageous option for POR women.


Assuntos
Hormônio Liberador de Gonadotropina , Nascimento Prematuro , Gravidez , Feminino , Humanos , Fertilização in vitro/métodos , Estudos Retrospectivos , Indução da Ovulação/métodos , Hormônio Luteinizante/farmacologia , Taxa de Gravidez , Ovulação , Nascimento Prematuro/tratamento farmacológico , Antagonistas de Hormônios/uso terapêutico , Antagonistas de Hormônios/farmacologia
14.
Curr Issues Mol Biol ; 45(6): 4796-4813, 2023 May 31.
Artigo em Inglês | MEDLINE | ID: mdl-37367054

RESUMO

Salinity is a major factor limiting rice productivity, and developing salt-tolerant (ST) varieties is the most efficient approach. Seventy-eight ST introgression lines (ILs), including nine promising lines with improved ST and yield potential (YP), were developed from four BC2F4 populations from inter-subspecific crosses between an elite Geng (japonica) recipient and four Xian (indica) donors at the Institute of Crop Sciences, Chinese Academy of Agricultural Sciences. Genome-wide characterization of donor introgression identified 35 ST QTLs, 25 of which harbor 38 cloned ST genes as the most likely QTL candidates. Thirty-four are Xian-Geng differentiated ones with the donor (Xian) alleles associated with ST, suggesting differentiated responses to salt stress were one of the major phenotypic differences between the two subspecies. At least eight ST QTLs and many others affecting yield traits were identified under salt/non-stress conditions. Our results indicated that the Xian gene pool contains rich 'hidden' genetic variation for developing superior Geng varieties with improved ST and YP, which could be efficiently exploited by selective introgression. The developed ST ILs and their genetic information on the donor alleles for ST and yield traits would provide a useful platform for developing superior ST and high-yield Geng varieties through breeding by design in the future.

15.
Opt Express ; 31(3): 4238-4252, 2023 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-36785397

RESUMO

Femtosecond lasers can be used to create many functional devices in silica optical fibers with high designability. In this work, a femtosecond laser-induced high scattering fiber (HSF) with randomly distributed high scattering centers is used to effectively compress the linewidth of a fiber laser for the first time. A dual-wavelength, single-longitudinal-mode (SLM) erbium-doped fiber laser (EDFL) is constructed for the demonstration, which is capable of switching among two single-wavelength operations and one dual-wavelength operation. We find that the delayed self-heterodyne beating linewidth of the laser can be reduced from >1 kHz to <150 Hz when the length of the HSF in the laser cavity increases from 0 m to 20 m. We also find that the intrinsic Lorentzian linewidth of the laser can be compressed to several Hz using the HSF. The efficiency and effectiveness of linewidth reduction are also validated for the case that the laser operates in simultaneous dual-wavelength lasing mode. In addition to the linewidth compression, the EDFL shows outstanding overall performance after the HSF is incorporated. In particular, the optical spectrum and SLM lasing state are stable over long periods of time. The relative intensity noise is as low as <-150 dB/Hz@>3 MHz, which is very close to the shot noise limit. The optical signal-to-noise ratios of >85 dB for single-wavelength operation and >83 dB for dual-wavelength operation are unprecedented over numerous SLM fiber lasers reported previously. This novel method for laser linewidth reduction is applicable across gain-medium-type fiber lasers, which enables low-cost, high-performance, ultra-narrow linewidth fiber laser sources for many applications.

16.
Opt Lett ; 48(13): 3431-3434, 2023 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-37390148

RESUMO

A TM polarizer working for whole optical communication bands with high performance is proposed on a 220-nm-thick silicon-on-insulator (SOI) platform. The device is based on polarization-dependent band engineering in a subwavelength grating waveguide (SWGW). By utilizing an SWGW with a relatively larger lateral width, an ultra-broad bandgap of ∼476 nm (1238 nm-1714nm) is obtained for the TE mode, while the TM mode is well supported in this range. Then, a novel tapered and chirped grating design is adopted for efficient mode conversion, which results in a polarizer with a compact footprint (3.0 µm × 18 µm), low insertion loss (IL < 1.15 dB) and high polarization extinction ratio (PER > 21 dB) covering O-U bands (1260 nm-1675 nm). Experimental results show that the fabricated device has an IL < 1.0 dB and PER > 22 dB over a 300- nm bandwidth, which is limited by our measurement setup. To the best of our knowledge, no TM polarizer on the 220-nm SOI platform with comparable performance covering O-U bands has ever been reported.


Assuntos
Engenharia , Silício
17.
Opt Lett ; 48(3): 656-659, 2023 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-36723556

RESUMO

Quick identification of abnormal molecular metabolism of bone tissues is challenging. Photoacoustic (PA) spectroscopy techniques have great potential in molecular imaging. However, most of them are amplitude-dependent and easily affected by the light deposition, especially for bone tissues with high optical scattering. In this Letter, we propose a Nakagami statistics-based PA spectroscopy (NSPS) method for characterizing molecules in bone tissues. We indicate that the NSPS curve can intelligently identify changes in the content of molecules in bone tissues, with a high disturbance-resisting ability. The NSPS has remarkable potential for use in the early and rapid detection of bone diseases.


Assuntos
Técnicas Fotoacústicas , Ultrassonografia/métodos , Espalhamento de Radiação , Análise Espectral/métodos , Osso e Ossos/diagnóstico por imagem
18.
Opt Lett ; 48(22): 5959-5962, 2023 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-37966762

RESUMO

We propose and experimentally demonstrate a four-wavelength-switchable single-longitudinal-mode (SLM) narrow linewidth thulium-holmium co-doped fiber laser (THDFL) using two polarization-dependent parallel fiber Bragg gratings (PD-PFBGs). The PD-PFBGs, fabricated using femtosecond (fs) laser direct-writing technology in a standard single-mode fiber (SMF) via a point-by-point method, are used as a four-channel reflection filter. Two FBGs are inscribed in parallel in the fiber core along the axial direction and are uniquely positioned symmetrically on either side of the centerline. This configuration enables polarization-dependent multi-channel filtering capability, which further allows for polarization-control-based four-wavelength-switchable operations of the THDFL. SLM lasing is accomplished by utilizing a simple dual-ring sub-cavity filter. An exceptional output performance of the THDFL is achieved, including an optical signal-to-noise ratio (SNR) of >72 dB, maximum power and wavelength fluctuations of 0.350 dB and 0.024 nm, respectively, and a linewidth of <2 kHz, for all four single-wavelength operations lasing at ∼2000 nm. These performance indicators suggest that the THDFL can be applied in free-space optical communication, atmospheric monitoring, and Lidar.

19.
Brain Behav Immun ; 108: 204-220, 2023 02.
Artigo em Inglês | MEDLINE | ID: mdl-36496170

RESUMO

Increasing evidence supports the pathogenic role of neuroinflammation in psychiatric diseases, including major depressive disorder (MDD) and neuropsychiatric symptoms of Coronavirus disease 2019 (COVID-19); however, the precise mechanism and therapeutic strategy are poorly understood. Here, we report that myeloid differentiation factor 88 (MyD88), a pivotal adaptor that bridges toll-like receptors to their downstream signaling by recruiting the signaling complex called 'myddosome', was up-regulated in the medial prefrontal cortex (mPFC) after exposure to chronic social defeat stress (CSDS) or severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spike protein. The inducible expression of MyD88 in the mPFC primed neuroinflammation and conferred stress susceptibility via amplifying immune danger signals, such as high-mobility group box 1 and SARS-CoV-2 spike protein. Overexpression of MyD88 aggravated, whereas knockout or pharmacological inhibition of MyD88 ameliorated CSDS-induced depressive-like behavior. Notably, TJ-M2010-5, a novel synthesized targeting inhibitor of MyD88 dimerization, alleviated both CSDS- and SARS-CoV-2 spike protein-induced depressive-like behavior. Taken together, our findings indicate that inhibiting MyD88 signaling represents a promising therapeutic strategy for stress-related mental disorders, such as MDD and COVID-19-related neuropsychiatric symptoms.


Assuntos
COVID-19 , Transtorno Depressivo Maior , Fator 88 de Diferenciação Mieloide , Humanos , Proteínas Adaptadoras de Transdução de Sinal/metabolismo , COVID-19/metabolismo , COVID-19/psicologia , Fator 88 de Diferenciação Mieloide/metabolismo , Doenças Neuroinflamatórias , SARS-CoV-2/metabolismo
20.
Helicobacter ; 28(6): e13030, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37871913

RESUMO

The microbiota actively and extensively participates in the regulation of human metabolism, playing a crucial role in the development of metabolic diseases. Helicobacter pylori (H. pylori), when colonizing gastric epithelial cells, not only induces local tissue inflammation or malignant transformation but also leads to systemic and partial changes in host metabolism. These shifts can be mediated through direct contact, toxic components, or indirect immune responses. Consequently, they influence various molecular metabolic events that impact nutritional status and iron absorption in the host. Unraveling the intricate and diverse molecular interaction links between H. pylori and human metabolism modulation is essential for understanding pathogenesis mechanisms and developing targeted treatments for related diseases. However, significant challenges persist in comprehensively understanding the complex association networks among H. pylori itself, the infected host's status, the host microbiome, and the immune response. Previous metabolomics research has indicated that H. pylori infection and eradication may selectively shape the metabolite and microbial profiles of gastric lesions. Yet, it remains largely unknown how these diverse metabolic pathways, including isovaleric acid, cholesterol, fatty acids, and phospholipids, specifically modulate gastric carcinogenesis or affect the host's serum metabolism, consequently leading to the development of metabolic-associated diseases. The direct contribution of H. pylori to metabolisms still lacks conclusive evidence. In this review, we summarize recent advances in clinical evidence highlighting associations between chronic H. pylori infection and metabolic diseases, as well as its potential molecular regulatory patterns.


Assuntos
Infecções por Helicobacter , Helicobacter pylori , Doenças Metabólicas , Humanos , Helicobacter pylori/fisiologia , Infecções por Helicobacter/complicações , Estômago/patologia , Homeostase
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