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1.
Nano Lett ; 2024 May 08.
Artigo em Inglês | MEDLINE | ID: mdl-38717095

RESUMO

The mapping of long-wavelength phonons is important to understand and manipulate the thermal transport in multilayered structures, but it remains a long-standing challenge due to the collective behaviors of phonons. In this study, an experimental demonstration of mapping the long-wavelength phonons in an alloyed Al0.1Ga0.9As/Al0.9Ga0.1As superlattice system is reported. Multiple strategies to filter out the short- to mid-wavelength phonons are used. The phonon mean-free-path-dependent thermal transport properties directly demonstrate both the suppression effect of the ErAs nanoislands and the contribution of long-wavelength phonons. The contribution from phonons with mean free path longer than 1 µm is clearly demonstrated. A model based on the Boltzmann transport equation is proposed to calculate and describe the thermal transport properties, which depicts a clear physical picture of the transport mechanisms. This method can be extended to map different wavelength phonons and become a universal strategy to explore their thermal transport in various application scenarios.

2.
Environ Sci Technol ; 58(6): 2881-2890, 2024 Feb 13.
Artigo em Inglês | MEDLINE | ID: mdl-38297912

RESUMO

The use of microbial electrochemical sensors, with electroactive biofilms (EABs) as sensing elements, is a promising strategy to timely measure the biochemical oxygen demand (BOD) of wastewater. However, accumulation of Coulombic yield over a complete degradation cycle is time-consuming. Therefore, understanding the correlation between current output and EAB metabolism is urgently needed. Here, we recognized a tail stage (TS) on a current-time curve according to current increase rate─a period with the least electron harvesting efficiency. EAB adopted a series of metabolic compensation strategies, including slow metabolism of residual BOD, suspended growth, reduced cell activity, and consumption of carbon storage polymers, to cope with substrate deficiency in TS. The supplementary electrons provided by the decomposition of glycogen and fatty acid polymers increased the Coulombic efficiencies of TS to >100%. The tail current produced by spontaneous metabolic compensation showed a trend of convergent exponential decay, independent of BOD concentration. Therefore, we proposed the TS prediction model (TSPM) to predict Coulombic yield, which shortened BOD measurement time by 96% (to ∼0.5 h) with deviation <4 mg/L when using real domestic wastewater. Our findings on current output in TS give insights into bacterial substrate storage and consumption, as well as regulation in substrate-deficient environment, and provide a basis for developing BOD sensors.


Assuntos
Técnicas Biossensoriais , Águas Residuárias , Biofilmes , Bactérias/metabolismo , Oxigênio/análise , Polímeros
3.
Materials (Basel) ; 17(2)2024 Jan 09.
Artigo em Inglês | MEDLINE | ID: mdl-38255495

RESUMO

AlN epilayers were grown on magnetron-sputtered (MS) (11-22) AlN buffers on m-plane sapphire substrates at 1450 °C via hydride vapour phase epitaxy (HVPE). The MS buffers were annealed at high temperatures of 1400-1600 °C. All the samples were characterised using X-ray diffraction, atomic force microscopy, scanning electron microscope and Raman spectrometry. The crystal quality of epilayers regrown by HVPE was improved significantly compared to that of the MS counterpart. With an increasing annealing temperature, the crystal quality of both MS buffers and AlN epilayers measured along [11-23] and [1-100] improved first and then decreased, maybe due to the decomposition of MS buffers, while the corresponding anisotropy along the two directions decreased first and then increased. The optimum quality of the AlN epilayer was obtained at the annealing temperature of around 1500 °C. In addition, it was found that the anisotropy for the epilayers decreased significantly compared to that of annealed MS buffers when the annealing temperature was below 1500 °C.

4.
EClinicalMedicine ; 67: 102403, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38261958

RESUMO

Background: Platinum-doublet chemotherapy plus immunotherapy has been the standard of care for the first-line treatment of advanced non-small cell lung cancer lacking actional driver mutations. However, optimization of drug combinations is still needed to find a better balance between therapeutic efficacy and safety in the immunotherapy era. We aimed to investigate the efficacy and safety of platinum-free albumin bound paclitaxel (nab-paclitaxel) combined with camrelizumab and apatinib as first-line treatment for patients with advanced lung adenocarcinoma. Methods: In this multicenter open-label, single-arm phase II trial, patients with systemic treatment-naïve advanced lung adenocarcinoma without epidermal growth factor receptor (EGFR) or anaplastic lymphoma kinase (ALK) mutations received a rational-based combination of camrelizumab (200 mg intravenously, day one), apatinib (250 mg, q.d., five continuous days per week), and nab-paclitaxel (135 mg/m2 intravenously, days one and eight) every three weeks for four to six cycles in China. Patients with controlled disease were maintained with camrelizumab and apatinib. The primary end point was progression-free survival (PFS). This trial is registered with ClinicalTrials.gov (No. NCT04459078). Findings: Between August 26, 2020 and May 20, 2022, 64 patients were enrolled. The median PFS was 14.3 (95% CI: 9.9, not reached) months. The confirmed objective response rate was 64.1% (95% CI: 51.1, 75.7). The grade 3-4 hematologic treatment-related adverse events (TRAEs) were decreased neutrophil count (14.1%), decreased white blood cell count (7.8%), and anemia (3.1%). The most common non-hematologic TRAEs of grade 3-4 were increased alanine transaminase (18.8%) and aspartate transaminase (15.6%). No treatment-related death occurred. The quality of life was on average not clinically meaningful worse through treatment cycle 14. Interpretation: Nab-paclitaxel plus camrelizumab and apatinib showed clinically meaningful anti-tumor activity and manageable safety, with few hematologic toxicities, and might be a potential treatment option in patients with advanced lung adenocarcinoma lacking EGFR/ALK mutations. Funding: Heath Research Foundation of Chinese Society of Clinical Oncology, Hunan Provincial Natural Science Foundation of China, Hunan Cancer Hospital Climb Plan, Sister Institution Network Fund of The University of Texas MD Anderson Cancer Center, The Science and Technology Innovation Program of Hunan Province, and Suzhou Sheng Diya Biomedical Co., Ltd, a subsidiary of Jiangsu Hengrui Pharmaceuticals Co., Ltd. (Shanghai, China).

5.
ACS Sens ; 8(6): 2383-2390, 2023 06 23.
Artigo em Inglês | MEDLINE | ID: mdl-37249569

RESUMO

Microbial electrochemical sensors are promising to monitor bioavailable organics in real environments, but their application is restricted by the unpredictable performance of the electroactive biofilm (EAB), which is randomly acclimated from environmental microflora. With a long-term stable EAB as a template, we successfully designed EAB (DEAB) by the sequential growth of Geobacter anodireducens and automatched microbes, achieving a reproducible high current than those naturally acclimated from wastewater (NEAB). Pre-inoculation of planktonic aerobes as oxygen bioscavengers was necessary to ensure the colonization of Geobacter in the inner layer, and the abundant Geobacter (50%) in DEAB guaranteed 4 times higher current density with a 15-fold smaller variation among 20 replicates than those of NEAB. The sensor constructed with DEAB exhibited a shorter measuring time and a precise biochemical oxygen demand (BOD) measurement with acetate, real domestic wastewater, and supernatant of anaerobic digestion. Here, we for the first time proposed an applicable strategy to standardize EABs for BOD sensors, which is also crucial to ensure a stable performance of all bioelectrochemical technologies.


Assuntos
Biofilmes , Águas Residuárias , Oxigênio/análise , Eletrodos
6.
Front Immunol ; 14: 1138203, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37215097

RESUMO

Background: Glioma, the most prevalent malignant intracranial tumor, poses a significant threat to patients due to its high morbidity and mortality rates, but its prognostic indicators remain inaccurate. Although TRAF-associated NF-kB activator (TANK) interacts and cross-regulates with cytokines and microenvironmental immune cells, it is unclear whether TANK plays a role in the immunologically heterogeneous gliomas. Methods: TANK mRNA expression patterns in public databases were analyzed, and qPCR and IHC were performed in an in-house cohort to confirm the clinical significance of TANK. Then, we systematically evaluated the relationship between TANK expression and immune characteristics in the glioma microenvironment. Additionally, we evaluated the ability of TANK to predict treatment response in glioma. TANK-associated risk scores were developed by LASSO-Cox regression and machine learning, and their prognostic ability was tested. Results: TANK was specifically overexpressed in glioma and enriched in the malignant phenotype, and its overexpression was related to poor prognosis. The presence of a tumor microenvironment that is immunosuppressive was evident by the negative correlations between TANK expression and immunomodulators, steps in the cancer immunity cycle, and immune checkpoints. Notably, treatment for cancer may be more effective when immunotherapy is combined with anti-TANK therapy. Prognosis could be accurately predicted by the TANK-related risk score. Conclusions: High expression of TANK is associated with the malignant phenotype of glioma, as it shapes an immunosuppressive tumor microenvironment. Additionally, TANK can be used as a predictive biomarker for responses to various treatments and prognosis.


Assuntos
Neoplasias Encefálicas , Glioma , Humanos , Adjuvantes Imunológicos , Neoplasias Encefálicas/genética , Neoplasias Encefálicas/terapia , Glioma/genética , Glioma/terapia , Imunossupressores , Prognóstico , Microambiente Tumoral
7.
Sci Total Environ ; 882: 163698, 2023 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-37094684

RESUMO

The inevitable deposition of S0 on the electroactive biofilm (EAB) via anodic sulfide oxidation affects the stability of bioelectrochemical systems (BESs) when an accidental discharge of sulfide occurred, leading to the inhibition of electroacitivity, because the potential of anode (e.g., 0 V versus Ag/AgCl) is ~500 mV more positive than the redox potential of S2-/S0. Here we found that S0 deposited on the EAB can be spontaneously reduced under this oxidative potential independent of microbial community variation, leading to a self-recovery of electroactivity (> 100 % in current density) with biofilm thickening (~210 µm). Transcriptomics of pure culture indicated that Geobacter highly expressed genes involving in S0 metabolism, which had an additional benefit to improve the viability (25 % - 36 %) of bacterial cells in biofilm distant from the anode and the cellular metabolic activity via electron shuttle pair of S0/S2-(Sx2-). Our findings highlighted the importance of spatially heterogeneous metabolism to its stability when EABs encountered with the problem of S0 deposition, and that in turn improved the electroactivity of EABs.


Assuntos
Fontes de Energia Bioelétrica , Geobacter , Biofilmes , Oxirredução , Geobacter/fisiologia , Eletrodos , Estresse Oxidativo
8.
Water Res ; 235: 119897, 2023 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-36963309

RESUMO

Biochemical oxygen demand (BOD) is a key indicator of water quality. However, there is still no technique to directly measure BOD at low concentrations in oxygen-rich environments. Here, we propose a new scheme using facultative electrotrophs as the sensing element, and confirmed aerobic Acinetobacter venetianus RAG-1 immobilized on electrode was able to measure BOD via the switchover between electrotrophic and heterotrophic respirations. The hybrid binder of Nafion and polytetrafluoroethylene (PTFE) maximized the baseline current (127 ± 2 A/m2) and sensitivity (2.5 ± 0.1 (mA/m2)/(mg/L)). The current decrease and the BOD5 concentration fitted well with a linear model in the case of known contaminants, verified with both lab samples of acetate and glucose (R2>0.96) and in standard curves of real environmental samples collected from the lake and the effluent of wastewater treatment plant (R2>0.98). Importantly, the biosensor tested actual contaminated water samples with an error of 0.4∼10% compared to BOD5 in the case of unknown contaminants. Transcriptomics revealed that reverse oxidative TCA may involve in the electrotrophic respiration of RAG-1 since citrate synthase (gltA) was highly expressed, which was partly downregulated when heterotrophic metabolism was triggered by BOD. This can be returned to electrotroph when BOD was depleted. Our results showed a new way to rapidly measure BOD in oxygen-rich environment, demonstrating the possibility to employ bacteria with two competitive respiration pathways for pollution detection.


Assuntos
Monitoramento Biológico , Técnicas Biossensoriais , Oxigênio/análise , Análise da Demanda Biológica de Oxigênio , Bactérias/metabolismo , Qualidade da Água
9.
Water Res ; 235: 119911, 2023 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-36989806

RESUMO

Direct interspecies electron transfer (DIET) has been demonstrated to be an efficient type of mutualism in methanogenesis. However, few studies have reported its presence in mixed microbial communities and its trigger mechanism in the natural environment and engineered systems. Here, we reported DIET-like mutualism of Geobacter and methanogens in the planktonic microbiome for the first time in anaerobic electrochemical digestion (AED) fed with propionate, potentially triggered by excessive cathodic hydrogen (56 times higher than the lowest) under the electrochemical condition. In contrast with model prediction without DIET, the highest current density and hydrogen and methane production were concurrently observed at -0.2 V where an abundance of Geobacter (49%) and extracellular electron transfer genes were identified in the planktonic microbiome via metagenomic analysis. Metagenomic assembly genomes annotated to Geobacter anodireducens were identified alongside two methanogens, Methanothrix harundinacea and Methanosarcina mazei, which were previously identified to participate in DIET. This discovery revealed that DIET-like mutualism could be triggered without external conductive materials, highlighting its potentially ubiquitous presence. Such mutualism simultaneously boosted methane and hydrogen production, thereby demonstrating the potential of AED in engineering applications.


Assuntos
Geobacter , Propionatos , Simbiose , Metano , Hidrogênio , Transporte de Elétrons , Dieta , Reatores Biológicos , Anaerobiose
10.
J Hazard Mater ; 444(Pt A): 130421, 2023 02 15.
Artigo em Inglês | MEDLINE | ID: mdl-36427483

RESUMO

Organohalide respiring bacteria (OHRB) are the mainstay for bioremediation of organohalide contaminated sites. Enrichment screening of OHRB is prerequisite for the development of high performance dehalogenating bacterial agents. Herein, different domestication strategies were formulated for the main factors (nutrients and inocula) affecting the enrichment of OHRB, and the dehalogenation effect was verified with 2-chlorophenol and per/polyfluoroalkyl substances. The nutrients had a greater impact on the dehalogenation of the systems relative to the inocula, where the combination of glucose and anaerobic sludge (Glu-AS) had a faster degradation rate (26 ± 2.5 µmol L-1 d-1) and more complete dechlorination effectiveness. Meanwhile, the dehalogenation results for perfluorooctanoic acid and trifluoroacetic acid showed the biological defluorination was closely related to the position of fluoride. Further, the microbial community structure profiled the resource competition, metabolic cross-feeding and nutrient dynamic exchange among fermenting bacteria, OHRB and methanogenic bacteria under different domestication strategies as endogenous factors affecting the dehalogenation performance, and speculated a hypothetical model for the interaction of different functional bacteria. Our research contributed guidelines and references for the development of efficient dehalogenating bacterial agents, and provided scientific theoretical and technical support for promoting the maximum efficiency of bioremediation of organohalogenated sites.


Assuntos
Euryarchaeota , Glucose , Aclimatação , Bactérias , Esgotos
11.
Sci Total Environ ; 858(Pt 2): 159794, 2023 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-36374751

RESUMO

Fe(III) oxides are ubiquitous electron acceptors for anaerobic bioremediation, although their bioavailability was limited due to the passivation of secondary mineralization products. Here we found the solid S0 can be added to improve their bioavailability. Using lepidocrocite (γ-FeOOH), acetate and Geobacter sulfurreducens PCA as representatives of Fe(III) oxides, intermediate of pollutant degradation and microbes, a 6 times higher amount of FeOOH reduction in the presence of S0 was observed with a time needed for S0 reduction shortened by half. The bioreduction of S0 activated the reduction of FeOOH, while the product (conductive FeS) may have bridged electron transfer across the cell membrane and periplasm. The proportion of excessive Fe(II) produced from Fe(III) was quantified as a direct bioreduction (26 %), with an abiotic FeOOH reduction to FeS (20 %) and an FeS-conducted FeOOH bioreduction (54 %), which highlight the key role of gradually formed FeS from S0 in the bioreduction of FeOOH. Our results showed that S0 can be an effective additive for the bioremediation of environments with abundant Fe(III) oxides, which has broader implications for elemental biogeochemical cycling.


Assuntos
Compostos Férricos , Óxidos , Compostos Férricos/metabolismo , Biodegradação Ambiental , Disponibilidade Biológica , Anaerobiose , Oxirredução , Enxofre
12.
J Hazard Mater ; 442: 130043, 2023 01 15.
Artigo em Inglês | MEDLINE | ID: mdl-36182882

RESUMO

Reducing the electrode spacing in bioelectrochemical systems (BESs) are widely reported to improve power output, which was mainly attributed to the decrease of ohmic resistance (Rohm) for a long time. Here we found the change of endogenous electric field (EF) intensity was the key to improve electroactivity in response to a reduced electrode spacing, which also accelerated phenol biodegradation. Correlation and principal components analysis revealed that the microbial community of electroactive biofilm (EAB) was independent of Rohm, while the EF intensity was found closely related to most of predominant genera. A strong EF selectively enriched phenol-degrading bacteria Comamonas in suspension and Geobacter in EAB, contributed to the improvement of degradation efficiency. EF also induced the secretion of extracellular polymeric substances, protected EAB from being inactivated by phenol. Our findings highlighted the importance of EF intensity on BESs performance, providing new insights into the design and application of BESs in wastewater treatment.


Assuntos
Fontes de Energia Bioelétrica , Geobacter , Geobacter/metabolismo , Eletrodos , Eletricidade , Biofilmes , Fenol/metabolismo
13.
Zhong Nan Da Xue Xue Bao Yi Xue Ban ; 47(6): 685-697, 2022 Jun 28.
Artigo em Inglês, Chinês | MEDLINE | ID: mdl-35837768

RESUMO

OBJECTIVES: Nasopharyngeal carcinoma (NPC) is a highly invasive epithelial malignant tumor with unique geographical and ethnic distribution characteristics. NPC is mostly found in south China and Southeast Asia, and its treatment mainly depends on radiotherapy and chemotherapy. However, NPC is usually found in the late stage, and local recurrence and distant metastasis are common, leading to poor prognosis. The receptor tyrosine kinase AXL is up-regulated in various tumors and it is involved in tumor proliferation, migration, invasion, and other processes, which are associated with poor prognosis of tumors. This study aims to detect the expression of AXL in NPC cell lines and tissues, and to investigate its biological function of AXL and the underlying molecular mechanisms in regulation of NPC. METHODS: The expression levels of AXL in normal nasopharyngeal epithelial tissues and NPC tissues were analyzed by GSE68799, GSE12452, and GSE53819 data sets based on Gene Expression Omnibus (GEO) database. The Cancer Genome Atlas (TCGA) database was used to analyze the relationship between AXL and prognosis of head and neck squamous cell carcinoma (HNSC). The indicators of prognosis included overall survival (OS), disease-free interval (DFI), disease-specific survival (DSS), and progression-free interval (PFI). Western blotting assay was used to detect the AXL protein expression levels in normal nasopharyngeal epithelial cell line and NPC cell lines. Immunohistochemical method was used to detect AXL expression levels in normal nasopharyngeal epithelial tissues and NPC tissues. Cell lines with stable AXL knockdown were established by infecting 5-8F and Fadu cells with lentivirus interference vector, and cell lines with stable AXL overexpression were established by infecting C666-1 and HK-1 cells with lentivirus expression vector. Real-time PCR and Western blotting were used to detect the efficiency of knockdown and overexpression in stable cell lines. The effects of AXL knockdown or overexpression on proliferation, migration, and invasion of NPC cells were detected by CCK-8, plate colony formation, and Transwell assays, and the effect of AXL knockdown on tumor growth in nude mice was detected by subcutaneous tumor formation assay. The sequence of AXL upstream 2.0 kb promoter region was obtained by UCSC online database. The PROMO online database was used to predict AXL transcription factors with 0% fault tolerance, and the JASPAR online database was used to predict the binding sites of ETS1 to AXL. Real-time PCR and Western blotting were used to detect the effect of ETS1 on AXL protein and mRNA expression. The AXL upstream 2.0 kb promoter region was divided into 8 fragments, each of which was 250 bp in length. Primers were designed for 8 fragments. The binding of ETS1 to AXL promoter region was detected by chromatin immuno-precipitation (ChIP) assay to determine the direct regulatory relationship between ETS1 and AXL. Rescue assay was used to determine whether ETS1 affected the proliferation, migration, and invasion of NPC cells through AXL. RESULTS: Bioinformatics analysis showed that AXL was highly expressed in NPC tissues (P<0.05), and AXL expression was positively correlated with OS, DFI, DSS, and PFI in HNSC patients. Western blotting and immunohistochemical results showed that AXL was highly expressed in NPC cell lines and tissues compared with the normal nasopharyngeal epithelial cell line and tissues. Real-time PCR and Western blotting results showed that knockdown and overexpression efficiency in the stable cell lines met the requirements of subsequent experiments. The results of CCK-8, plate colony formation, Transwell assays and subcutaneous tumor formation in nude mice showed that down-regulation of AXL significantly inhibited the proliferation, migration, invasion of NPC cells and tumor growth (all P<0.05), and the up-regulation of AXL significantly promoted the proliferation, migration, and invasion of NPC cells (all P<0.05).As predicted by PROMO and JASPAR online databases, ETS1 was a transcription factor of AXL and had multiple binding sites in the AXL promoter region. Real-time PCR and Western blotting results showed that knockdown or overexpression of ETS1 down-regulated or up-regulated AXL protein and mRNA expression levels. ChIP assay result showed that ETS1 bound to AXL promoter region and directly regulate AXL expression. Rescue assay showed that AXL rescued the effects of ETS1 on proliferation, migration and invasion of NPC cells (P<0.05). CONCLUSIONS: AXL is highly expressed in NPC cell lines and tissues, which can promote the malignant progression of NPC, and its expression is regulated by transcription factor ETS1.


Assuntos
Neoplasias Nasofaríngeas , Animais , Linhagem Celular Tumoral , Movimento Celular/genética , Proliferação de Células/genética , Regulação Neoplásica da Expressão Gênica , Camundongos , Camundongos Nus , Carcinoma Nasofaríngeo/genética , Neoplasias Nasofaríngeas/metabolismo , RNA Mensageiro/genética , Sincalida/metabolismo , Fatores de Transcrição/genética
14.
Micron ; 160: 103324, 2022 09.
Artigo em Inglês | MEDLINE | ID: mdl-35816928

RESUMO

Using ultraviolet-visible-near infrared (UV-Vis-NIR) diffuse reflectance spectroscopy, Raman spectroscopy, and field emission scanning electron microscope (FE-SEM), we comparatively investigated the unique spectral characteristics of different natural-color Edison pearls. Edison pearls were firstly divided into two types based on theirs corresponding reflection spectral characteristics: type A with basically uniform reflection feature for each sample; and type B with non-uniform reflection feature for each one. Raman spectroscopy revealed that complex organic pigments with bands at about 1015, 1124-1134, 1297, 1507-1526, 2245, 2620, and 3019 cm-1, gave rise to the colors of Edison pearls. Interestingly, two bands in the Raman spectra of dark-colored pearls, at about 1124-1134 cm-1 and 1507-1526 cm-1, corresponded to the stretching modes of the C-C single bond (ν2) and the CC double bond (ν1), respectively, shifted significantly toward low wavenumbers. Meanwhile, the intensity ratio between the two bands (I1124-1134/I1085) increased as pearl color became more saturated. In addition, six bands at about 2139, 2417, 2521, 2976, 3332, and 3702 cm-1 were present in the Raman spectra of all dark-colored samples, while these bands were absent in the Raman spectra of light-colored ones. This indicated that the exact organic pigments in Edison pearls were not completely consistent, which led to variation in the coloration and the dominant absorption band in the reflection spectra of pearl. More importantly, based on our SEM results, as well as our UV-Vis reflectance spectroscopic analysis, we first proposed that the positions and relative intensities of the reflection peaks located between 320 nm and 600 nm were likely to be associated with the density and the degree of regularity of grooves appeared on the surface of pearl. These findings substantially enhance our knowledge of gemological characteristics of colored Edison pearl and the formation mechanism of unique reflection features of them. Furthermore, this study revealed key characteristics that can be used to identify imitation and color-treated Edison pearls.


Assuntos
Corantes , Análise Espectral Raman
15.
RSC Adv ; 12(3): 1897-1903, 2022 Jan 05.
Artigo em Inglês | MEDLINE | ID: mdl-35425151

RESUMO

Polymer-based thermal interface materials (TIMs) have attracted wide attention in the field of thermal management because of their outstanding properties including light weight, low cost, corrosion resistance and easy processing. However, the low thermal conductivity (∼0.2 W m-1 K-1) of the intrinsic polymer matrix largely degrades the overall thermal performance of polymer-based TIMs even those containing highly thermal conductive fillers. Hence, enhancing the intrinsic thermal conductivity of the polymer matrix is one of the most critical problems needed to be solved. This paper studies the thermal conductivity of poly(3,4-ethylenedioxythiophene) (PEDOT) films fabricated via cyclic voltammetry. By controlling the number of cycles in the electrochemical synthesis, different thickness of PEDOT films could be obtained. A time-domain thermoreflectance (TDTR) system was employed to evaluate the thermal performance of such as-prepared PEDOT films. We have demonstrated that a PEDOT film with thickness of 40 nm achieves the highest out-of-plane thermal conductivity of ∼0.60 W m-1 K-1, which is almost three folds the thermal conductivity of commercially available pristine PEDOT:PSS film with similar thickness. The X-ray diffraction spectrum reveals that the PEDOT thin film with high crystallinity at the initial stage of electrochemical synthesis leads to enhanced thermal transportation. The findings in this work not only offer an opportunity to fabricate polymer materials exhibiting enhanced thermal conductivity, but also allow one to adjust the thermal performance of conducting polymers in practical applications.

16.
ACS Appl Mater Interfaces ; 14(18): 21348-21355, 2022 May 11.
Artigo em Inglês | MEDLINE | ID: mdl-35482578

RESUMO

Vertical graphene nanowalls (VGNs) with excellent heat-transfer properties are promising to be applied in the thermal management of electronic devices. However, high growth temperature makes VGNs unable to be directly prepared on semiconductors and polymers, which limits the practical application of VGNs. In this work, the near room-temperature growth of VGNs was realized by utilizing the hot filament chemical vapor deposition method. Catalytic tantalum (Ta) filaments promote the decomposition of acetylene at ∼1600 °C. Density functional theory calculations proved that C2H* was the main active carbon cluster during VGN growth. The restricted diffusion of C2H* clusters induced the vertical growth of graphene nanoflakes on various substrates below 150 °C. The direct growth of VGNs successfully realized the excellent interfacial contact, and the thermal contact resistance could reach 3.39 × 10-9 m2·K·W-1. The temperature of electronic chips had a 6.7 °C reduction by utilizing directly prepared VGNs instead of thermal conductive tape as thermal-interface materials, indicating the great potential of VGNs to be directly prepared on electronic devices for thermal management.

17.
Int J Biol Sci ; 18(3): 1134-1149, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35173544

RESUMO

Metastasis is the main cause of death in patients with nasopharyngeal carcinoma (NPC). The molecular mechanisms underlying the metastasis of NPC remain to be elucidated. TBL1X has been shown abnormally expressed in diverse cancers. However, the role and mechanism of TBL1X in NPC remain unknown. Here, we showed TBL1X expression was significantly higher in metastatic NPC tissues compared to non-metastatic tissues and significantly correlated with TNM stage and metastasis of NPC patients. In addition, NPC patients with high TBL1X expression had a poor prognosis. TBL1X interacted with TCF4 to trans-activate Flot2 expression. TBL1X promoted NPC cell migration and invasion in vitro and in vivo through Flot2. Moreover, Flot2 increased the expression of TBL1X by upregulating c-myc, which was identified to be a positively regulatory transcription factor of TBL1X. TBL1X could restore the functional changes of NPC cells resulting from Flot2 alteration. TBL1X and Flot2 were positively correlated in NPC. Patients with high expression of both TBL1X and Flot2 possessed poorer overall survival (OS) and disease-free survival (DFS) compared to patients with high expression of any single one of the two proteins. Our findings demonstrate that TBL1X and Flot2 positively regulate each other to promote NPC metastasis, which provides novel potential molecular targets for NPC treatment.


Assuntos
Carcinoma , Neoplasias Nasofaríngeas , Carcinoma/genética , Linhagem Celular Tumoral , Movimento Celular/genética , Retroalimentação , Regulação Neoplásica da Expressão Gênica/genética , Humanos , Carcinoma Nasofaríngeo/genética , Neoplasias Nasofaríngeas/metabolismo
18.
Water Res ; 213: 118185, 2022 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-35183018

RESUMO

Electroactive biofilms have attracted increasing attention due to their unique ability to exchange electrons with electrodes. Geobacter spp. are widely found to be dominant in biofilms in acetate-rich environments when an appropriate voltage is applied, but it is still largely unknown how these bacteria are selectively enriched. Herein, two key Geobacter spp. that have been demonstrated predominant in wastewater-enriched electroactive biofilm after long-term operation, G. sulfurreducens and G. anodireducens, responded to electric field (EF) differently, leading to a higher abundance of EF-sensitive G. anodireducens in the strong EF region after cocultivation with G. sulfurreducens. Transcriptome analysis indicated that two-component systems containing sensor histidine kinases and response regulators were the key for EF sensing in G. anodireducens rather than in G. sulfurreducens, which are closely connected to chemotaxis, c-di-GMP, fatty acid metabolism, pilus, oxidative phosphorylation and transcription, resulting in an increase in extracellular polymeric substance secretion and rapid cell proliferation. Our data reveal the mechanism by which EF select specific Geobacter spp. over time, providing new insights into Geobacter biofilm formation regulated by electricity.

19.
Micromachines (Basel) ; 13(1)2022 Jan 14.
Artigo em Inglês | MEDLINE | ID: mdl-35056294

RESUMO

High-quality AlN film is a key factor affecting the performance of deep-ultraviolet optoelectronic devices. In this work, high-temperature annealing technology in a nitrogen atmosphere was used to improve the quality of AlN films with different polarities grown by magnetron sputtering. After annealing at 1400-1650 °C, the crystal quality of the AlN films was improved. However, there was a gap between the quality of non-polar and polar films. In addition, compared with the semi-polar film, the quality of the non-polar film was more easily improved by annealing. The anisotropy of both the semi-polar and non-polar films decreased with increasing annealing temperature. The results of Raman spectroscopy, scanning electron microscopy and X-ray photoelectron spectroscopy revealed that the annihilation of impurities and grain boundaries during the annealing process were responsible for the improvement of crystal quality and the differences between the films with different polarities.

20.
Environ Res ; 203: 111802, 2022 01.
Artigo em Inglês | MEDLINE | ID: mdl-34343555

RESUMO

Anaerobic ammonium oxidation coupled to Fe(III) reduction, known as Feammox, is a newly discovered nitrogen-cycling process, which serves an important role in the pathways of nitrogen loss in the environment. However, the specific types of microorganisms involved in Feammox currently remain unclear. In this study, we selected two groups of soil samples (paddy and mine), from considerably different habitats in South China, to acclimate Feammox colonies. The Paddy Group had a shorter lag period than the Mine Group, while the ammonium transformation rate was nearly equal in both groups in the mature period. The emergence of the Feammox activity was found to be associated with the increased abundance of iron-reducing bacteria, especially Clostridium_sensu_stricto_12, Desulfitobacterium, Thermoanaerobaculum, Anaeromyxobacter and Geobacter. Ammonium oxidizing archaea and methanogens were dominant among the known archaea. These findings extend our knowledge of the microbial community composition of the potential Feammox microbes from soils under different environmental conditions, which broadens our understanding of this important Fe/N transformation process.


Assuntos
Compostos de Amônio , Solo , Archaea , Bactérias , Compostos Férricos , Nitrogênio/análise , Oxirredução , Microbiologia do Solo
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