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1.
Nanoscale ; 12(7): 4393-4399, 2020 Feb 20.
Artigo em Inglês | MEDLINE | ID: mdl-32025692

RESUMO

The growth of nonpolar GaN nanowires along the [101[combining macron]0] orientation has been demonstrated via a modified hydride vapor phase epitaxy (HVPE) process using GaCl3 and NH3 as precursors. The morphology and structure evolution as a dependence of the growth parameters was thoroughly studied to elucidate the nucleation and crystallization of nonpolar GaN nanowires. It has been found that the V/III ratio and temperature are critically important for the formation of high-quality nonpolar GaN nanowires. The existence of a cubic GaN (c-GaN) transition layer between the Au catalyst and hexagonal GaN (h-GaN) nonpolar nanowires was demonstrated by high-resolution transmission electron microscopy (HRTEM) characterization, which plays an important role in the initial nucleation of nonpolar GaN nanowires and the formation of stacking faults (SFs) in the GaN nanowires grown at lower temperature. Optical investigations show that the defect-related visible emission of nonpolar GaN nanowires is closely related to the growth process and can be selectively tailored. The synthetic strategy using GaCl3 as the Ga precursor to study the vapor phase epitaxy process in this work will provide a simple and efficient approach to obtain nonpolar GaN nanowires and will thus pave a solid way for fundamental research on high-quality nonpolar GaN nanowires in optoelectronic nanodevices.

4.
Medicine (Baltimore) ; 99(5): e18952, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-32000418

RESUMO

RATIONALE: Alveolar soft part sarcoma (ASPS) is a rare malignant soft tissue neoplasm with controversial histogenesis. ASPS accounts for 0.5% to 1% of all soft tissue sarcomas. Because of its rarity, ASPS is easily misdiagnosed, increasing the risk of incorrect treatment. PATIENT CONCERNS: A 6-year-old female patient presented with a history of a 2.0 × 2.5 × 3.0-cm mass in the deep soft tissues of her right lower extremity. DIAGNOSES: Histopathological features indicated the diagnosis of ASPS. Microscopically, a diffuse arrangement of tumor cells or pseudoalveolar architectures separated by thin and well-vascularized fibrous septa were observed. Immunohistochemical staining of the tumor cells indicated positivity for transcription factor E3, myogenic determination factor 1, and periodic acid-Schiff-diastase (PAS-D) and showed a Ki-67 proliferating index of approximately 20%. INTERVENTIONS: The patient underwent enlarged resection of the tumor and was treated with radiotherapy. OUTCOMES: During the 3-year follow-up, the patient has remained in good condition, with no symptom recurrence, distant metastatic spread, or significant toxicity during or after treatment. The patient remains under regular surveillance. LESSONS: Its low incidence, lack of characteristic clinical manifestations, and atypical location often lead to ASPS misdiagnosis and subsequent incorrect treatment. Nuclear expression of transcription factor E3 is of diagnostic value for ASPS. At present, there is no consensus on the treatment for ASPS. In-depth pathological analysis is needed to better understand the characteristics of this tumor.


Assuntos
Sarcoma Alveolar de Partes Moles/diagnóstico , Neoplasias de Tecidos Moles/diagnóstico , Criança , Diagnóstico Diferencial , Feminino , Humanos , Perna (Membro)/diagnóstico por imagem , Perna (Membro)/patologia , Sarcoma Alveolar de Partes Moles/patologia , Sarcoma Alveolar de Partes Moles/radioterapia , Sarcoma Alveolar de Partes Moles/cirurgia , Neoplasias de Tecidos Moles/patologia , Neoplasias de Tecidos Moles/radioterapia , Neoplasias de Tecidos Moles/cirurgia
5.
Bioorg Med Chem Lett ; 30(6): 126967, 2020 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-32005415

RESUMO

Inhibition of the nuclear receptor Retinoic Acid Receptor-Related Orphan Receptor γt (RORγt) is a promising strategy for the treatment of autoimmune diseases. In this paper, we describe a series of allosteric, cysteine-dependent, inverse agonists of RORγt. Site-directed mutagenesis and molecular dynamics simulations are supportive of a mechanism of action through specific binding to Cys476 on alpha helix 11 of the ligand binding domain (LBD). Representative compounds in the series selectively inhibit RORγt, potently suppress interleukin-17A (IL-17A) production by human CD4+ T cells, and inhibit T helper 17 (Th17) differentiation from human naïve CD4+ T cells. The advanced compound 13 is orally bioavailable and active at a dose of 3 mg/kg in a murine collagen-induced model of rheumatoid arthritis. Collectively, these data are supportive of the development of compound 13 in autoimmune diseases.

6.
Bioresour Technol ; 303: 122947, 2020 Feb 03.
Artigo em Inglês | MEDLINE | ID: mdl-32045865

RESUMO

Enhanced macroalgal biochars with large specific surface areas (up to 399 m2 g-1), partly graphitized structure, high nitrogen doping (up to 6.14%), and hydrophobicity were fabricated by co-carbonization of macroaglae, ferric chloride, and zinc chloride. These biochars were used as sorbents for the removal of polycyclic aromatic hydrocarbons from water. The sorption capacity of polycyclic aromatic hydrocarbons onto macroalgal biochars was high (up to 90 mg g-1), and recycling by thermal desorption was practicable. We revealed the physical-dominated multilayer sorption process, based on results from characterization and sorption experiments. Pore filling, mass transfer, π-π stacking, and the partition effect were found to be possible sorption mechanisms. This study suggests that porous graphitized nitrogen-doped biochars may be synthesized from macroalgae with simple one-pot carbonization and display promising applicability for sorption removal of organic pollutants from water.

7.
Waste Manag ; 105: 190-197, 2020 Feb 17.
Artigo em Inglês | MEDLINE | ID: mdl-32078983

RESUMO

Analyzing diazotrophic community may help to understand nitrogen transformation in composting and improves the final compost quality. In this study, diazotrophic community dynamics were investigated in terms of nifH gene during dairy manure and corn straw composting with biochar addition using high-throughput sequencing. Biochar decreased the diversity of diazotrophic community and altered diazotroph community structure during composting. At phylum level, Proteobacteria, Actinobacteria and Firmicutes were dominant diazotrophic communities throughout composting process. Biochar addition registered higher correlation coefficient (R) between physicochemical factors (temperature, ammonium (NH4+-N) and nitrate (NO3--N)) and diazotroph community composition. Rhodopseudomonas and Pseudoxanthomonas was the key diazotrophic communities influencing NH4+-N transformation in control (CK) and biochar compost (BC), respectively, while for NO3--N transformation Clostridium and Bradyrhizobium in CK, Azospira and Methylocystis in BC served as predominant factors. These results indicated that addition of biochar altered the key diazotroph communities influencing nitrogen transformation. Furthermore, some diazotrophs (e.g. Rhodopseudomonas, Bradyrhizobium and Azospira) affecting NH4+-N and NO3--N transformation were also observed to be mediating total nitrogen (TN). Interestingly, interactions between diazotrophic communities were observed and these interactions could also influence nitrogen transformation.

8.
Chemistry ; 2020 Jan 21.
Artigo em Inglês | MEDLINE | ID: mdl-31961024

RESUMO

Cubic silicon carbide (3C-SiC) material feature a suitable band gap and high resistance to photo corrosion. It thus has been emerged as a promising semiconductor for hydrogen evolution. Herein, the relationship between the photoelectrochemical properties and the microstructures of different SiC materials is demonstrated. For visible-light derived water splitting to hydrogen production, nanocrystalline, microcrystalline and epitaxial (001) 3C-SiC films are applied as the photocathodes. The epitaxial 3C-SiC film presents the highest photoelectrochemical activity for hydrogen evolution, because of its perfect (001) orientation, high phase purity, low resistance, and negative conduction band energy level. This finding offers a strategy to design SiC-based photocathodes with superior photoelectrochemical performances.

9.
Inorg Chem ; 2020 Jan 21.
Artigo em Inglês | MEDLINE | ID: mdl-31961145

RESUMO

In this report, we describe the synthesis of two porphyrin-containing Pt(II) supramolecular assemblies via coordination-driven self-assembly. X-ray crystallographic analysis on one assembly reveals that the metalla-assembly formation imposes large interchromophore distances, leading to a higher 1O2 generation efficiency, relative to the corresponding small molecular precursors. The metalla-assemblies were examined as photosensitizers for photodynamic therapy as the potential reduction of the unfavorable self-aggregation phenomenon. In vivo and in vitro investigations demonstrate that the metalla-assemblies exhibit enhanced anticancer activity with minimal dose requirement and side effects comparable to the small molecule precursors. Thus, our work demonstrates that self-assembly provides a promising methodology for enhancing the therapeutic effectiveness of anticancer agents.

10.
Int J Immunogenet ; 2020 Jan 14.
Artigo em Inglês | MEDLINE | ID: mdl-31943768

RESUMO

Hepatocellular carcinoma (HCC) is the third leading cause of cancer-related death worldwide. Studies have shown that the tumour necrosis factor alpha (TNF-α) plays an important role in the development of HCC; however, the association between genetic variations of TNF-α and HCC is not yet fully understood. To evaluate the correlation of TNF-α polymorphisms with HCC, we randomly selected 327 HCC patients and 432 healthy controls, all these subjects reported Han nationality. Genotyping of four TNF-α SNPs (rs1799724, rs1800629, rs1799964 and rs1800610) was performed using the matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF-MS) method. Distributions of rs1799964 genotypes and rs1800610 alleles were found to be significantly different between cases and controls (p = .011, p = .001). The recessive model of rs1799964 significantly increased HCC risk (p = .0015), while the dominant and over-dominant models of rs1800610 significantly reduced HCC risk (p = .0096, p = .014). Haplotype analysis of the four TNF-α SNPs revealed that the TGTA haplotype was associated with a reduced HCC risk (p = .0033, OR = 0.53), while the TGTG haplotype was associated with an increased HCC risk (p = .0032, OR = 9.69). These findings indicated that specific TNF-α polymorphisms may be associated with the susceptibility to HCC.

11.
Crit Rev Biotechnol ; 40(2): 169-179, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31906713

RESUMO

Current biological wastewater treatment is energy intensive. The application of algal-bacterial consortia to treat wastewater has recently attracted considerable attention because mechanical aeration is unnecessary. Therefore, algal-bacterial bioreactors are emerging as alternatives to activated sludge-based bioprocesses. Most studies have used a plate substratum to support the growth of algal-bacterial biofilms, which results in low reactor efficiencies. Usually, 2-10 days are required for targeted pollutant removal effects. Substratum structures can significantly influence reactor efficiencies. Indeed, substratum-free biofilms (granules) generally achieve high reactor efficiencies that rapidly form. 7-12 h are sufficient for a high-level pollutant removal efficiency. However, granule stability must be validated during long-term experiments (>1 year) involving real wastewater. In addition, the application of algal-bacterial membrane bioreactors represents a novel treatment approach. In membrane bioreactors, good reactor efficiencies and stabilities can be achieved. However, the maximum capacity of algal-bacterial membrane bioreactors requires further investigation. In addition, an accurate model for pollutant removal kinetics in algal-bacterial reactors is not yet available but is necessary for reactor control and up-scaling. The microbial and physical structures of algal-bacterial biofilms require more studies to clarify the system. Finally, the operational costs of algal-bacterial systems must be kept low in order to enhance their potential for sewage treatment at large scales. Good illumination control and recycling biomass for biodiesel or methane production could be applied to reducing the operation cost.

12.
Ecotoxicol Environ Saf ; 190: 110123, 2020 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-31891837

RESUMO

In this work, a novel manganese dioxide-graphene nanosheets (MnO2-GNSs) composite was synthesized by a facile one-step hydrothermal method, in which manganese dioxide (MnO2) was fabricated by hydrothermal reduction of KMnO4 with GNSs. The structure and morphology of MnO2-GNSs composite were characterized by scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD) analysis and X-ray photoelectron spectroscopy (XPS). A sensitive non-enzymatic electrochemical sensor based on MnO2-GNSs composite for the detection of low concentration hydrogen peroxide (H2O2) was fabricated. The electrochemical properties of MnO2-GNSs composite modified glassy carbon electrode (MnO2-GNSs/GCE) were investigated by cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS) and amperometry. The observations confirmed that the fabricated sensor exhibited high electrocatalytic activity for oxidation of H2O2 owing to the catalytic ability of MnO2 particles and the conductivity of GNSs. Under the optimum conditions, the calibration curve was linear for the amperometric response versus H2O2 concentration over the range 0.5-350 µM with a low detection limit of 0.19 µM (S/N = 3) and high sensitivity of 422.10 µA mM-1 cm-2. The determination and quantitative analysis of H2O2 in antiseptic solution on MnO2-GNSs/GCE exhibited percent recovery of 96.50%-101.22% with relative standard deviation (RSD) of 1.48%-4.47%. The developed MnO2-GNSs/GCE might be a promising platform for the practical detection of H2O2 due to its prominent properties including excellent reproducibility, good anti-interference and repeatability.

13.
Artigo em Inglês | MEDLINE | ID: mdl-31925688

RESUMO

This study examined the influence of biochar addition on fungal community during composting of cow manure using high-throughput sequencing. Two treatments were set up, including compost of cow manure plus 10% biochar (BC) and cow manure compost without biochar (CK). Fungal community composition varied obviously during composting in both treatments, and main fungi included Aspergillus, Myriococcum, Thermomyces, Mycothermus, Scedosporium, Cladosporium, and unclassified Microascaceae. Fungal community composition was altered by biochar during composting, especially during the thermophilic and the cooling phase, promoting Aspergillus and Myriococcum while inhibiting unclassified Microascaceae and Thermomyces. Based on linear discriminant analysis effect size analysis, common indicator groups were detected in both composts; however, specific indicator groups were also found in BC treatment, including Clavicipitaceae, Tremellales, Gibberella, and Coprinopsis. Canonical correspondence analysis (CCA) indicated that moisture content, organic matter, C/N, and pH had significant correlation (p < 0.05) with fungal composition in both treatments. However, in compost added with biochar, temperature was not an important factor affecting fungal community (p > 0.05).

14.
Anal Chem ; 92(3): 2566-2572, 2020 Feb 04.
Artigo em Inglês | MEDLINE | ID: mdl-31922394

RESUMO

We hereby described an electrochemiluminescence (ECL) biosensor for glutathione (GSH) based on a 3D DNA matrix with ordered binding sites and cavity structure that self-assembled from tetrahedral DNA blocks (TDBs). First, the alkyne-labeled TDBs were employed to build an alkyne-rich 3D matrix (C≡C-3DM) on the electrode surface. Then, the GSH-induced click chemistry was triggered as a signal switch to introduce the large amounts of N3-DNA decorated AuAg nanoclusters (N3-AuAg NCs) into C≡C-3DM for signal output. In particular, the presence of GSH could induce the formation of GSH-Cu(I) complex by the redox reaction between GSH and Cu(II), which could act as an initiator to link the N3-AuAg NCs with C≡C-3DM according to the Huisgen 1,3-dipolar cycloaddition reaction. By this way, numerous N3-AuAg NCs were orderly bonded to the 3D matrix to effectively reduce their agglomeration and inner filter effect, achieving a remarkable ECL enhancement. As a result, the proposed GSH biosensor showed a wide linear range from 5 to 200 µM with a low detection limit of 0.90 µM. In general, this work provided a rapid, highly efficient, and convenient signal amplification for small-molecule detection and broadened the application of TDBs in biosensing.

15.
Artigo em Inglês | MEDLINE | ID: mdl-31961639

RESUMO

Despite the rocketing rise in power conversion efficiencies (PCEs), the performance of perovskite solar cells (PSCs) is still limited by the carrier transfer loss at the interface between perovskite (PVSK) absorbers and charge transporting layers. Here, we propose a novel in situ passivation strategy by using [6,6]-phenyl-C61-butyric acid methyl ester (PCBM) to improve the charge dynamics at the rear PVSK/CTL interface in the n-i-p structure device. A pre-deposited PCBM-doped PbI2 layer is redissolved during PVSK deposition in our routine, establishing a bottom-up PCBM gradient that is facile for charge extraction. Meanwhile, the surface defects are in situ-passivated via PCBM-PVSK interaction, which substantially suppresses the trap-assisted recombination at the rear interface. Due to the synergistic effect of charge-extraction promotion and trap passivation, the fabricated PSCs deliver a champion PCE of 20.10% with attenuated hysteresis and improved long-term stability, much higher than the 18.39% of the reference devices. Our work demonstrates a promising interfacial engineering strategy for further improving the performance of PSCs.

16.
ACS Appl Mater Interfaces ; 12(6): 6933-6943, 2020 Feb 12.
Artigo em Inglês | MEDLINE | ID: mdl-31951372

RESUMO

The normoxic and hypoxic microenvironments in solid tumors cause cancer cells to show different sensitivities to various treatments. Therefore, it is essential to develop different therapeutic modalities based on the tumor microenvironment. In this study, we designed size-switchable nanoparticles with self-destruction and tumor penetration characteristics for site-specific phototherapy of cancer. This was achieved by photodynamic therapy in the perivascular normoxic microenvironment due to high local oxygen concentrations and photothermal therapy (PTT) in the hypoxic microenvironment, which are not in proximity to blood vessels due to a lack of effective approaches for heat transfer. In brief, a poly(amidoamine) dendrimer with photothermal agent indocyanine green (PAMAM-ICG) was conjugated to the amphiphilic polymer through a singlet oxygen-responsive thioketal linker and then loaded with photosensitizer chlorin e6 (Ce6) to construct a nanotherapy platform (denoted as SNPICG/Ce6). After intravenous injection, SNPICG/Ce6 was accumulated at the perivascular sites of the tumor. The singlet oxygen produced by Ce6 can ablate the tumor cells in the normoxic microenvironment and simultaneously cleave the thioketal linker, allowing the release of small PAMAM-ICGs with improved tumor penetration for PTT in the hypoxic microenvironment. This tailored site-specific phototherapy in normoxic and hypoxic microenvironments provides an effective strategy for cancer therapy.

17.
Ecotoxicol Environ Saf ; 191: 110161, 2020 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-31954219

RESUMO

Denitrification and nitrification processes are the two prominent pathways of nitrogen (N) transformation in composting matrix. This study explored the dynamics of denitrifying and nitrifying bacteria at different composting stages of cow manure and corn straw using functional gene sequencing at DNA and cDNA levels. Corresponding agreement among OTUs, NMDS, mental test and network analyses revealed that functional bacteria community compositions and responses to physicochemical factors were different at DNA and cDNA levels. Specifically, some OTUs were detected at the DNA level but were not observed at cDNA level, differences were also found in the distribution patterns of nitrifying and denitrifying bacteria communities at both levels. Furthermore, co-occurrence network analysis indicated that Pseudomonas, Paracoccus and Nitrosomonas were identified as the keystone OTUs at the DNA level, while Paracoccus, Agrobacterium and Nitrosospira were keystone OTUs at the cDNA level. Mantel test revealed that TN, C/N and moisture content significantly influenced both the denitrifying bacteria and ammonia-oxidizing bacteria (AOB) communities at the DNA level. NO3--N, NH4+-N, TN, C/N, and moisture content only registered significant correlation with the nosZ-type denitrifiers and ammonia-oxidizing bacteria (AOB) communities at the cDNA level. Structural equation model (SEM) showed that TN, NH4+-N, and pH were direct and significantly influenced the gene abundance of denitrifying bacteria. Howbeit, TN, NH4+-N, and NO3--N had significant direct effects on amoA gene abundance.

18.
Biochem Biophys Res Commun ; 523(2): 522-526, 2020 Mar 05.
Artigo em Inglês | MEDLINE | ID: mdl-31902587

RESUMO

Isolation of trabecular meshwork stem cells in vitro provides the foundation of a novel treatment for glaucoma. Trabecular meshwork stem cells (TMSCs) of the fetal calve were extracted and cultured for this experiment. TMSCs were isolated through side population cell sorting. TMSCs were then identified using immunofluorescent staining. Extracellular matrix (ECM) expression in TM cells derived from TMSCs was evaluated with Western blot. Our results showed a positive expression of stem cell markers Notch1 and OCT-3/4 in TMSCs, but no TM cells markers TIMP3 or AQP1. In contrast, primary TM cells expressed these TM cell markers but no stem cell markers. Our result confirmed that there are expression of ECM components, such as fibronectin, laminin, collagen I and collagen IV in TM cells differentiated from TMSCs. CONCLUSION: TM cells derived from TMSCs can secrete ECM components which is important for sustain the physiological function.

19.
Artigo em Inglês | MEDLINE | ID: mdl-31990180

RESUMO

The integration of sp2-/sp3-bonded carbon has aroused increasing attention on attaining a great electron field emission (EFE) performance. Herein, a novel hierarchical diamond@carbon nanowalls/diamond (D@C/D) architecture is facilely prepared through the growth of the hybrid carbon nanowalls/diamond (C/D) film followed by the in situ hydrogen plasma treatment using microwave plasma chemical vapor deposition. The hierarchical D@C/D architecture is composed of thin diamond nanoplatelets sandwiched into carbon nanowalls (CNWs) as the bottom layer and the thickened nanoplatelets constituted by diamond nanograins as the upper layer. The hydrogen plasma plays an effective role in the transformation of sacrificial sp2-bonded CNWs to sp3-bonded diamond, eventually leading to the template thickening of diamond nanoplatelets in the upper layer. Impressively, the D@C/D-90 film demonstrates much better EFE behaviors of low turn-on potential (Eo = 4.3 V µm-1), high current density (Je@8 V µm-1 = 20.81 mA cm-1), and superior long-term stability, in comparison with the pristine C/D film (Eo = 6 V µm-1, Je@8 V µm-1 = 0.33 mA cm-1). The enhanced EFE performance of the hierarchical D@C/D film is ascribed to the well-established graphite pathway for electrons transported from the bottom to the top and the increased diamond emitting sites with negative electron-affinity and robust nature at the top. This work will promote the development of the high-performance cathode EFE material based on hybrid sp2/sp3-bonded carbon, and the method proposed here also provides an effective strategy to construct a diamond nanostructure for various applications.

20.
Bull Environ Contam Toxicol ; 104(2): 157-165, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31898750

RESUMO

The amendment of biochar in soils contaminated with persistent organic pollutants (POPs) is an environmentally friendly in situ remediation measure. Numerous studies focused on the application of biochars to reduce the uptake of POPs by plants in soils. In this review, we summarized the role of biochar in reducing the migration of POPs in soil-plant systems. The mechanisms of biochar reducing the bioavailability of POPs in the soil, i.e. immobilization and promoted biodegradation, and the influencing factors are fully discussed. Especially in rhizosphere amended with biochar, the synergistic effect of POPs-root exudates-microorganisms on the reduced bioavailability of POPs is analyzed. This paper suggests that future researches should focus on the long-term environmental fate of POPs sorbed on high-temperature biochars and the long-term impacts of low-temperature biochars on the interaction of POPs-root exudates-rhizosphere microorganisms. All the above are necessary for efficient and safe use of biochar for remediating POP-contaminated farmland soils.

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