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1.
Small ; : e2404215, 2024 Jul 07.
Artigo em Inglês | MEDLINE | ID: mdl-38973090

RESUMO

Aqueous nickel-ion batteries (ANIBs) as an emerging energy storage device attracted much attention owing to their multielectron redox reaction and dendrite-free Ni anode, yet their development is hindered by the divalent properties of Ni2+ and the lack of suitable cathode materials. Herein, a hydrated iron vanadate (Fe2V3O10.5∙1.5H2O, FOH) with a preferred orientation along the (200) plane is innovatively proposed and used as cathode material for ANIBs. The FOH cathode exhibits a remarkable capacity of 129.3 mAh g-1 at 50 mA g-1 and a super-high capacity retention of 95% at 500 mA g-1 after 700 cycles. The desirable Ni2+ storage capacity of FOH can be attributed to the preferentially oriented and tunnel structures, which offer abundant reaction active planes and a broad Ni2+ diffusion path, the abundant vacancies and high specific surface area further increase ion storage sites and accelerate ion diffusion in the FOH lattice. Furthermore, the Ni2+ storage mechanism and structural evolution in the FOH cathode are explored through ex situ XRD, ex situ Raman, ex situ XPS and other ex situ characteristics. This work opens a new way for designing novel cathode materials to promote the development of ANIBs.

2.
J Transl Med ; 22(1): 21, 2024 01 04.
Artigo em Inglês | MEDLINE | ID: mdl-38178094

RESUMO

BACKGROUND: Oral squamous cell carcinoma (OSCC), the predominant malignancy of the oral cavity, is characterized by high incidence and low survival rates. Emerging evidence suggests a link between circadian rhythm disruptions and cancer development. The circadian gene TIMELESS, known for its specific expression in various tumors, has not been extensively studied in the context of OSCC. This study aims to explore the influence of TIMELESS on OSCC, focusing on cell growth and metabolic alterations. METHODS: We analyzed TIMELESS expression in OSCC using western blot, immunohistochemistry, qRT-PCR, and data from The Cancer Genome Atlas (TCGA) and the Cancer Cell Line Encyclopedia (CCLE). The role of TIMELESS in OSCC was examined through clone formation, MTS, cell cycle, and EdU assays, alongside subcutaneous tumor growth experiments in nude mice. We also assessed the metabolic impact of TIMELESS by measuring glucose uptake, lactate production, oxygen consumption, and medium pH, and investigated its effect on key metabolic proteins including silent information regulator 1 (SIRT1), hexokinase 2 (HK2), pyruvate kinase isozyme type M2 (PKM2), recombinant lactate dehydrogenase A (LDHA) and glucose transporter-1 (GLUT1). RESULTS: Elevated TIMELESS expression in OSCC tissues and cell lines was observed, correlating with reduced patient survival. TIMELESS overexpression enhanced OSCC cell proliferation, increased glycolytic activity (glucose uptake and lactate production), and suppressed oxidative phosphorylation (evidenced by reduced oxygen consumption and altered pH levels). Conversely, TIMELESS knockdown inhibited these cellular and metabolic processes, an effect mirrored by manipulating SIRT1 levels. Additionally, SIRT1 was positively associated with TIMELESS expression. The expression of SIRT1, HK2, PKM2, LDHA and GLUT1 increased with the overexpression of TIMELESS levels and decreased with the knockdown of TIMELESS. CONCLUSION: TIMELESS exacerbates OSCC progression by modulating cellular proliferation and metabolic pathways, specifically by enhancing glycolysis and reducing oxidative phosphorylation, largely mediated through the SIRT1 pathway. This highlights TIMELESS as a potential target for OSCC therapeutic strategies.


Assuntos
Peptídeos e Proteínas de Sinalização do Ritmo Circadiano , Glucose , Neoplasias Bucais , Carcinoma de Células Escamosas de Cabeça e Pescoço , Animais , Humanos , Camundongos , Linhagem Celular Tumoral , Proliferação de Células/genética , Glucose/metabolismo , Transportador de Glucose Tipo 1 , Lactatos , Camundongos Nus , Neoplasias Bucais/genética , Neoplasias Bucais/patologia , Sirtuína 1/metabolismo , Carcinoma de Células Escamosas de Cabeça e Pescoço/genética , Carcinoma de Células Escamosas de Cabeça e Pescoço/patologia , Peptídeos e Proteínas de Sinalização do Ritmo Circadiano/genética
3.
Opt Express ; 32(2): 2554-2560, 2024 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-38297781

RESUMO

We investigate the robustness of a modified multi-trench fiber (MTF) design with two gaps numerically. The excellent suppression of high-order modes is demonstrated over a wide range of the gap misalignment and the fundamental mode loss is barely affected even with the 5 dB/m scattering loss in gaps at the modified two-gap MTF for the first time. Therefore, the required fabrication accuracy decreases.

4.
Phys Rev Lett ; 132(13): 133603, 2024 Mar 29.
Artigo em Inglês | MEDLINE | ID: mdl-38613308

RESUMO

An integrated quantum light source is increasingly desirable in large-scale quantum information processing. Despite recent remarkable advances, a new material platform is constantly being explored for the fully on-chip integration of quantum light generation, active and passive manipulation, and detection. Here, for the first time, we demonstrate a gallium nitride (GaN) microring based quantum light generation in the telecom C-band, which has potential toward the monolithic integration of quantum light source. In our demonstration, the GaN microring has a free spectral range of 330 GHz and a near-zero anomalous dispersion region of over 100 nm. The generation of energy-time entangled photon pair is demonstrated with a typical raw two-photon interference visibility of 95.5±6.5%, which is further configured to generate a heralded single photon with a typical heralded second-order autocorrelation g_{H}^{(2)}(0) of 0.045±0.001. Our results pave the way for developing a chip-scale quantum photonic circuit.

5.
Opt Express ; 31(26): 42850-42865, 2023 Dec 18.
Artigo em Inglês | MEDLINE | ID: mdl-38178394

RESUMO

The co-route optical fibers, comprising both co-cable and co-trench fibers, pose a significant potential risk to network service quality assurance by operators. They are incapable of achieving high-precision recognition and visual state management. In this study, we gathered both static and dynamic optical fiber data using a linewidth tunable light source (LTLS) and introduced a multimodal detection architecture that applies ensemble learning to the collected data. This constitutes what we believe to be the first field trial of concurrent recognition of optical fibers found both in co-cables and co-trenches. To identify co-cable fibers, we employed a double-layer cascaded Random Forest (DLC-RF) model based on the static features of fibers. For co-trench fiber, the dynamic characteristics of fiber vibrations are utilized in combination with multiple independent curve similarity contrast learners for classifying tasks. The proposed architecture is capable of automatically detecting the condition of the optical fiber and actively identifying the same routing segment within the network, eliminating the need for human intervention and enabling the visualization of passive optical fiber resources. Finally, after rigorous testing and validation across 11 sites in a typical urban area, including aggregation and backbone scenarios within the operator's live network environments, we have confirmed that the solution's ability to identify co-routes is accurate, exceeding 95%. This provides strong empirical evidence of its effectiveness.

6.
Opt Lett ; 48(6): 1367-1370, 2023 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-36946929

RESUMO

With the increasing signal rates of a long-haul backbone dense-wavelength-division-multiplexing (DWDM) transmission system, e.g., from 100 Gb/s to 400 Gb/s and even to 800 Gb/s, optical path impairments simultaneously become more severe. Harmful factors being formerly insignificant become noticeable, e.g., nonlinear phase noise (NPN) on main DWDM channels induced by the cross-phase modulation (XPM) from the low-speed optical supervisory channel (OSC). Field trials show that a greater than 5.13-dB penalty can be observed on the shortest channel of 400G DP-16QAM-PCS over G.654.E links, which greatly degrades the overall transmission performance and limits the maximum reach. In this paper, we propose a dual-OSC structure with opposite signals to compensate for performance degradation caused by OSC-induced NPN. This method involves no extra digital signal processing (DSP), which is not only simple but also applicable for universal signal rates. By experimental demonstration, a 1.32-dB gain in Q (dB) for 200G DP-16QAM transmission over 1618-km G.652.D can be done, almost achieving the same performance as the no OSC case.

7.
J Psychiatry Neurosci ; 48(4): E295-E304, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37437921

RESUMO

BACKGROUND: Increasing evidence suggests that heroin addiction may be related to the dysfunction among the triple brain network (default mode network [DMN], salience network [SN] and executive control network [ECN]). However, the characteristics of glucose metabolism and metabolic connectivity among core regions of the triple brain network remain unknown. Therefore, we hypothesized that individuals with heroin dependence would show abnormal glucose metabolism and accompanied abnormal metabolic connectivity within the triple brain network. METHODS: Individuals with heroin dependence and healthy controls matched for age and sex underwent integrated positron emission tomography/magnetic resonance imaging (PET/MRI). Differences in glucose metabolism and metabolic connectivity among the DMN, SN and ECN were analyzed based on 18F-fluorodeoxyglucose PET and resting-state fMRI data. RESULTS: We included 36 individuals with heroin dependence and 30 matched healthy controls in our study. The heroin dependence group showed a significant reduction of glucose metabolism in the bilateral anterior insula (AI) and inferior parietal lobule (IPL), and a significantly decreased metabolic connectivity between the right AI and the left dorsolateral prefrontal cortex (DLPFC). The daily dose of methadone was negatively correlated with glucose metabolism of the right AI and right IPL. LIMITATIONS: The results revealed the glucose metabolism alterations and metabolic connectivity only within the triple brain network in individuals with heroin dependence; additional brain networks should be investigated in future studies. Although methadone is an opioid with a similar neurophysiological mechanism as heroin, the specific chronic effects of methadone on cerebral metabolism and metabolic connectivity should also be investigated in future studies. CONCLUSION: Our findings suggest that long-term opioid use might, to some extent, be associated with reduced synergistic ability between the SN and ECN, which may be associated with the dysfunction of cognitive control. In particular, the right AI, which showed hypometabolism and related reduction in SN-ECN metabolic connectivity, should receive increasing attention in future studies.


Assuntos
Dependência de Heroína , Imageamento por Ressonância Magnética , Humanos , Dependência de Heroína/diagnóstico por imagem , Analgésicos Opioides , Glucose , Metadona , Tomografia por Emissão de Pósitrons
8.
Eur Spine J ; 32(7): 2441-2447, 2023 07.
Artigo em Inglês | MEDLINE | ID: mdl-37217823

RESUMO

OBJECTIVE: Neurogenic bladder (NGB) is a serious complication after spinal cord injury (SCI), a destructive neurological disease. This study focused on exploring the efficacy of the magnetic stimulation of sacral nerve roots combined with Tui-na in treating NGB after SCI. METHODS: One hundred patients with NGB after SCI were studied, and intermittent clean catheterization was performed with a water intake program, and patients were grouped into four groups by the random number table method: general treatment group, Tui-na group, magnetic stimulation group, and combined treatment group. A series of relevant factors (voiding diary, urodynamics, and quality of life scores) and clinical efficacy of patients in the four groups before and after treatment were observed. RESULTS: The magnetic stimulation of sacral nerve roots alone, Tui-na alone, and the combination of both were all effective in improving bladder function and quality of life in patients with NGB after SCI, including improvements in voiding frequency, single urine output, maximum urine output, residual urine output, bladder volume and quality of life scores in patients with NGB after SCI. The efficacy of the magnetic stimulation of sacral nerve roots combined with Tui-na was better than that of the magnetic stimulation of sacral nerve roots alone and the Tui-na alone. CONCLUSION: This research demonstrates that the magnetic stimulation of sacral nerve roots combined with Tui-na treatment could effectively improve the urinary system and the quality of life of patients with NGB after SCI, which is worthy of clinical promotion and application.


Assuntos
Traumatismos da Medula Espinal , Bexiga Urinaria Neurogênica , Humanos , Bexiga Urinaria Neurogênica/etiologia , Bexiga Urinaria Neurogênica/terapia , Bexiga Urinária/inervação , Qualidade de Vida , Traumatismos da Medula Espinal/complicações , Traumatismos da Medula Espinal/terapia , Raízes Nervosas Espinhais , Fenômenos Magnéticos
9.
Small ; 18(29): e2202404, 2022 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-35754182

RESUMO

The alkaline polymer electrolyte fuel cells (APEFCs) hold great promise for using nonnoble metal-based electrocatalysts toward the cathodic oxygen reduction reaction (ORR), but are hindered by the sluggish anodic hydrogen oxidation reaction (HOR) in alkaline electrolytes. Here, a strategy is reported to promote the alkaline HOR performance of Ru by incorporating 3d-transition metals (V, Fe, Co, and Ni), where the conduction band minimum (CBM) level of Ru can be rationally tailored through strong d-d orbital coupling. As expected, the obtained RuFe nanosheet exhibits outstanding HOR performance with the mass activity of 233.46 A gPGM -1 and 23-fold higher than the Ru catalyst, even threefold higher than the commercial Pt/C. APEFC employing this RuFe as anodic catalyst gives a peak power density of 1.2 W cm-2 , outperforming the documented Pt-free anodic catalyst-based APEFCs. Experimental results and density functional theory calculations suggest the enhanced OH-binding energy and reduced formation energy of water derived from the downshifted CBM level of Ru contribute to the enhanced HOR activity.

10.
Surg Endosc ; 36(5): 3298-3307, 2022 05.
Artigo em Inglês | MEDLINE | ID: mdl-34313862

RESUMO

BACKGROUND: We compared short-term perioperative outcomes after single-incision plus one-port laparoscopic gastrectomy (SILG+1) and conventional multi-port laparoscopy-assisted gastrectomy (C-LAG) for gastric cancer. METHODS: The work was conducted between August 2017 and October 2019. A total of 90 patients with early or advanced gastric cancer were retrospectively analyzed: 43 patients of which underwent SILG+1, and 47 of which underwent C-LAG, respectively. These were divided into two groups: the total gastrectomy group (SILT+1 and C-LATG) and the distal gastrectomy group (SILD + 1 and C-LADG). The demographics, tumor characteristics, postoperative outcomes, and short-term complications of all enrolled patients were summarized and statistically analyzed. RESULTS: The mean incision length in SILT+1 group was 5.40 cm shorter than that in C-LATG group (3.15 ± 0.43 vs. 8.55 ± 2.72, P < 0.001). This comparison between the SILD + 1 and the C-LADG group produced comparable results. The SILT+1 group underwent a 56.32 min longer operation than the C-LATG group (273.03 ± 66.80 vs. 216.71 ± 82.61, P = 0.0205). SILG+1 group had better postoperative visual analog scale (VAS) and cosmetic score than those of the C-LATG group (P < 0.05). There were no significant differences in preoperative demographics or 30-day postoperative complication rates between the SILG+1 and C-LAG groups. Tumor-related index, including mass size, histological type, number of retrieved lymph nodes, pathological tumor-node-metastasis (TNM) stage, and proximal and distal edges were all equivalent between the SILG+1 and the C-LAG group. CONCLUSIONS: This retrospective study demonstrates the safety and feasibility of SILG+1 with D1+ or D2 lymphadenectomy for the treatment of early and advanced gastric cancers, compared with C-LAG.


Assuntos
Laparoscopia , Neoplasias Gástricas , Ferida Cirúrgica , Gastrectomia/métodos , Humanos , Laparoscopia/métodos , Excisão de Linfonodo/métodos , Complicações Pós-Operatórias/epidemiologia , Complicações Pós-Operatórias/etiologia , Complicações Pós-Operatórias/cirurgia , Estudos Retrospectivos , Neoplasias Gástricas/patologia , Ferida Cirúrgica/complicações , Resultado do Tratamento
11.
Addict Biol ; 27(2): e13121, 2022 03.
Artigo em Inglês | MEDLINE | ID: mdl-34841633

RESUMO

The abnormal interactions of three key large-scale brain networks (default mode [DMN], salience and executive control [ECN]) were showed underlie dysfunctions in heroin addiction. Repetitive transcranial magnetic stimulation (rTMS) targeting the left dorsolateral prefrontal cortex (DLPFC) is a potential treatment for heroin addiction. It is unclear whether impaired coupling among the large-scale brain networks would be improved by rTMS in treated heroin-dependent individuals. Thirty-five heroin-dependent individuals were included in this sham-controlled, randomized study. The patients received either active or sham rTMS for 1 week. The craving for heroin and resting-state functional magnetic resonance imaging data were collected before and after 1-week rTMS. Twenty-two healthy subjects were included as controls not receiving rTMS. After 1-week rTMS, only the active rTMS group showed a significant decrease in spontaneous and heroin cue-induced craving. The coupling between left DLPFC (a key node of left ECN) and left parahippocampal gyrus (PHG, included in DMN) significantly increased for the active group with a tendency towards that of controls. The coupling between the right precentral gyrus and three key regions included in DMN (posterior cingulate cortex/precuneus and bilateral inferior parietal cortex) significantly decreased for the active group with a tendency towards that of healthy controls. For the active rTMS individuals, the left DLPFC-PHG coupling negatively correlated with the spontaneous craving and the drug cue-induced craving. It suggested that the rTMS could reduce heroin craving, which might be related to the modulation of ECN-DMN coupling. This finding might shed light on the mechanism of rTMS for heroin addiction treatment.


Assuntos
Heroína , Estimulação Magnética Transcraniana , Encéfalo/diagnóstico por imagem , Fissura/fisiologia , Humanos , Imageamento por Ressonância Magnética , Córtex Pré-Frontal/diagnóstico por imagem , Estimulação Magnética Transcraniana/métodos
12.
Sensors (Basel) ; 22(8)2022 Apr 13.
Artigo em Inglês | MEDLINE | ID: mdl-35458964

RESUMO

Large-scale terminals' various QoS requirements are key challenges confronting the resource allocation of Satellite Internet of Things (S-IoT). This paper presents a deep reinforcement learning-based online channel allocation and power control algorithm in an S-IoT uplink scenario. The intelligent agent determines the transmission channel and power simultaneously based on contextual information. Furthermore, the weighted normalized reward concerning success rate, power efficiency, and QoS requirement is adopted to balance the performance between increasing resource efficiency and meeting QoS requirements. Finally, a practical deployment mechanism based on transfer learning is proposed to promote onboard training efficiency and to reduce computation consumption of the training process. The simulation demonstrates that the proposed method can balance the success rate and power efficiency with QoS requirement guaranteed. For S-IoT's normal operation condition, the proposed method can improve the power efficiency by 60.91% and 144.44% compared with GA and DRL_RA, while its power efficiency is only 4.55% lower than that of DRL-EERA. In addition, this method can be transferred and deployed to a space environment by merely 100 onboard training steps.

13.
Sensors (Basel) ; 22(9)2022 Apr 26.
Artigo em Inglês | MEDLINE | ID: mdl-35591010

RESUMO

In this paper, we propose a multi-scene adaptive crowd counting method based on meta-knowledge and multi-task learning. In practice, surveillance cameras are stationarily deployed in various scenes. Considering the extensibility of a surveillance system, the ideal crowd counting method should have a strong generalization capability to be deployed in unknown scenes. On the other hand, given the diversity of scenes, it should also effectively suit each scene for better performance. These two objectives are contradictory, so we propose a coarse-to-fine pipeline including meta-knowledge network and multi-task learning. Specifically, at the coarse-grained stage, we propose a generic two-stream network for all existing scenes to encode meta-knowledge especially inter-frame temporal knowledge. At the fine-grained stage, the regression of the crowd density map to the overall number of people in each scene is considered a homogeneous subtask in a multi-task framework. A robust multi-task learning algorithm is applied to effectively learn scene-specific regression parameters for existing and new scenes, which further improve the accuracy of each specific scenes. Taking advantage of multi-task learning, the proposed method can be deployed to multiple new scenes without duplicated model training. Compared with two representative methods, namely AMSNet and MAML-counting, the proposed method reduces the MAE by 10.29% and 13.48%, respectively.


Assuntos
Algoritmos , Aglomeração , Coleta de Dados , Humanos
14.
Proc Natl Acad Sci U S A ; 115(12): 3114-3119, 2018 03 20.
Artigo em Inglês | MEDLINE | ID: mdl-29511101

RESUMO

Neural circuits utilize a coordinated cellular machinery to form and eliminate synaptic connections, with the neuronal cytoskeleton playing a prominent role. During larval development of Caenorhabditis elegans, synapses of motor neurons are stereotypically rewired through a process facilitated by dynamic microtubules (MTs). Through a genetic suppressor screen on mutant animals that fail to rewire synapses, and in combination with live imaging and ultrastructural studies, we find that intermediate filaments (IFs) stabilize MTs to prevent synapse rewiring. Genetic ablation of IFs or pharmacological disruption of IF networks restores MT growth and rescues synapse rewiring defects in the mutant animals, indicating that IF accumulation directly alters MT stability. Our work sheds light on the impact of IFs on MT dynamics and axonal transport, which is relevant to the mechanistic understanding of several human motor neuron diseases characterized by IF accumulation in axonal swellings.


Assuntos
Caenorhabditis elegans/fisiologia , Proteínas de Filamentos Intermediários/metabolismo , Microtúbulos/fisiologia , Neurônios Motores/fisiologia , Animais , Transporte Axonal , Proteínas de Caenorhabditis elegans/metabolismo , Citoesqueleto/metabolismo , Regulação da Expressão Gênica/fisiologia , Proteínas de Filamentos Intermediários/genética , Neurônios Motores/citologia , Sinapses/fisiologia
15.
Opt Lett ; 45(5): 1212-1215, 2020 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-32108808

RESUMO

We have investigated a magnet-free, nonreciprocal surface wave absorber based on high impedance surfaces (HISs) using a spatial-temporal modulation approach. By controlling embedded switches with a travelling wave, the HIS metasurface is modulated to break the time and spatial symmetry, which enables surface waves to propagate in one direction but be absorbed when propagating in the reverse direction. The nonreciprocity has been demonstrated by an EM-circuit co-simulation. We envision that this could be possibly applied in future communication systems that preferably transmit unidirectionally but absorb interference from the reverse direction caused by reflections or other devices.

16.
Int J Neurosci ; 129(5): 417-422, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30375250

RESUMO

PURPOSE: To create a standard Western Chinese normal functional brain database for quantitative analysis using 2-deoxy-2-[18F] fluoro-d-glucose (18F-FDG) positron emission tomography (PET) images and MIMneuro software. METHODS: 78 healthy right-handed Chinese volunteers from Tangdu Hospital were scanned using 18F-FDG PET to evaluate brain metabolism between March and October 2016. All PET images were processed using MIMneuro software to create a normal database platform. The platform included anatomical optimization to facilitate spatial localization of abnormalities and a statistical comparison with normal cases utilizing the Z-scores, which represent the number of standard deviations from the mean of the normal controls in the database. RESULTS: The novel Chinese brain metabolism database platform including 78 healthy volunteers (male: female 40:38; age 3-78 years, mean age, 45 years) was constructed based on the MIMneuro software, which increased the diagnostic confidence in the test patient by quantifying and emphasizing the abnormality. The BrainAlignTM deformation algorithm of MIMneuro matched the size, shape, and orientation of the patient's brain scan to a template brain for comparison against a database of normal controls. The quantitative analysis performed on a voxel and regional level was useful in assessing the areas of abnormalities. CONCLUSIONS: A novel Chinese 18F-FDG PET-based normal brain function database was created to highlight the local regions of abnormal metabolic activity through quantitative comparisons against the normal database. The Z-scores obtained by MIMneuro potentially aid in visualizing and quantifying the subtle lesions on 18FDG-PET scan images as observed in a patient diagnosed with epilepsy.


Assuntos
Encéfalo/diagnóstico por imagem , Bases de Dados Factuais , Epilepsia/diagnóstico por imagem , Fluordesoxiglucose F18 , Processamento de Imagem Assistida por Computador , Tomografia por Emissão de Pósitrons , Adolescente , Adulto , Idoso , Encéfalo/metabolismo , Criança , Pré-Escolar , China , Bases de Dados Factuais/estatística & dados numéricos , Epilepsia/metabolismo , Feminino , Humanos , Processamento de Imagem Assistida por Computador/estatística & dados numéricos , Masculino , Pessoa de Meia-Idade , Imagem Multimodal , Tomografia por Emissão de Pósitrons combinada à Tomografia Computadorizada/estatística & dados numéricos , Tomografia por Emissão de Pósitrons/estatística & dados numéricos , Adulto Jovem
17.
Appl Opt ; 57(11): 2930-2934, 2018 Apr 10.
Artigo em Inglês | MEDLINE | ID: mdl-29714297

RESUMO

An optical pulse generation scheme based on an ultra-short chirped seed pulse generator followed by a dual-stage fiber-based nonlinear pulse processing stage is proposed and demonstrated experimentally. After phase modulation and linear-chirp compensation, optical seed pulse with a duty cycle of 9.8% and an obvious pedestal is obtained. By soliton compression and Mamyshev reshaping, a pedestal-free optical pulse with a duty cycle of 2% and an extinction ratio of 27 dB is achieved. The optical pulse source is further applied in a 16×25-Gb/s on-off keying optical time-division multiplexing transmitter.

18.
J Cell Sci ; 126(Pt 17): 4015-25, 2013 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-23788428

RESUMO

When NF-κB activation or protein synthesis is inhibited, tumor necrosis factor alpha (TNFα) can induce apoptosis through Bax- and Bak-mediated mitochondrial outer membrane permeabilization (MOMP) leading to caspase-3 activation. Additionally, previous studies have implicated lysosomal membrane permeability (LMP) and formation of reactive oxygen species (ROS) as early steps of TNFα-induced apoptosis. However, how these two events connect to MOMP and caspase-3 activation has been largely debated. Here, we present the novel finding that LMP induced by the addition of TNFα plus cycloheximide (CHX), the release of lysosomal cathepsins and ROS formation do not occur upstream but downstream of MOMP and require the caspase-3-mediated cleavage of the p75 NDUFS1 subunit of respiratory complex I. Both a caspase non-cleavable p75 mutant and the mitochondrially localized antioxidant MitoQ prevent LMP mediated by TNFα plus CHX and partially interfere with apoptosis induction. Moreover, LMP is completely blocked in cells deficient in both Bax and Bak, Apaf-1, caspase-9 or both caspase-3 and -7. Thus, after MOMP, active caspase-3 exerts a feedback action on complex I to produce ROS. ROS then provoke LMP, cathepsin release and further caspase activation to amplify TNFα apoptosis signaling.


Assuntos
Caspase 3/metabolismo , Permeabilidade da Membrana Celular/fisiologia , Complexo I de Transporte de Elétrons/metabolismo , NADH Desidrogenase/metabolismo , Fator de Necrose Tumoral alfa/metabolismo , Animais , Apoptose , Fator Apoptótico 1 Ativador de Proteases/deficiência , Fator Apoptótico 1 Ativador de Proteases/metabolismo , Caspase 3/deficiência , Caspase 3/genética , Caspase 7/deficiência , Caspase 7/genética , Caspase 9/deficiência , Caspase 9/metabolismo , Catepsina B/deficiência , Catepsina B/genética , Catepsina L/deficiência , Catepsina L/genética , Membrana Celular/metabolismo , Cicloeximida/farmacologia , Ativação Enzimática , Células HeLa , Humanos , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Mitocôndrias/metabolismo , Membranas Mitocondriais/metabolismo , NADH Desidrogenase/biossíntese , NADH Desidrogenase/genética , Compostos Organofosforados/farmacologia , Inibidores da Síntese de Proteínas/farmacologia , Espécies Reativas de Oxigênio , Ubiquinona/análogos & derivados , Ubiquinona/farmacologia , Proteína Killer-Antagonista Homóloga a bcl-2/deficiência , Proteína Killer-Antagonista Homóloga a bcl-2/metabolismo , Proteína X Associada a bcl-2/deficiência , Proteína X Associada a bcl-2/metabolismo
19.
Cell Regen ; 13(1): 12, 2024 Jun 11.
Artigo em Inglês | MEDLINE | ID: mdl-38861103

RESUMO

Macrophages play crucial and versatile roles in regulating tissue repair and regeneration upon injury. However, due to their complex compositional heterogeneity and functional plasticity, deciphering the nature of different macrophage subpopulations and unraveling their dynamics and precise roles during the repair process have been challenging. With its distinct advantages, zebrafish (Danio rerio) has emerged as an invaluable model for studying macrophage development and functions, especially in tissue repair and regeneration, providing valuable insights into our understanding of macrophage biology in health and diseases. In this review, we present the current knowledge and challenges associated with the role of macrophages in tissue repair and regeneration, highlighting the significant contributions made by zebrafish studies. We discuss the unique advantages of the zebrafish model, including its genetic tools, imaging techniques, and regenerative capacities, which have greatly facilitated the investigation of macrophages in these processes. Additionally, we outline the potential of zebrafish research in addressing the remaining challenges and advancing our understanding of the intricate interplay between macrophages and tissue repair and regeneration.

20.
J Phys Chem Lett ; 15(4): 1019-1027, 2024 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-38253014

RESUMO

Understanding the behavior of a polaron in contact with water is of significant importance for many photocatalytic applications. We investigated the influence of water on the localization and transport properties of polarons at the rutile (110) surface by constrained density functional theory. An excess electron at a dry surface favors the formation of a small polaron at the subsurface Ti site, with a preferred transport direction along the [001] axis. As the surface is covered by water, the preferred spatial localization of the polarons is moved from the subsurface to the surface. When the water coverage exceeds half a monolayer, the preferred direction of polaron hopping is changed to the [110] direction toward the surface. This characteristic behavior is related to the Ti3d-orbital occupations and crystal field splitting induced by different distorted structures under water coverage. Our work describes the reduced sites that might eventually play a role in photocatalysis for rutile (110) surfaces in a water environment.

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