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1.
Langmuir ; 40(24): 12322-12342, 2024 Jun 18.
Artigo em Inglês | MEDLINE | ID: mdl-38830755

RESUMO

Silicon carbide, as a third-generation semiconductor material, plays a pivotal role in various advanced technological applications. Its exceptional stability under extreme conditions has garnered a significant amount of attention. These superior characteristics make silicon carbide an ideal candidate material for high-frequency, high-power electronic devices and applications in harsh environments. In particular, corrosion resistance in natural or artificially acidic and alkaline environments limits the practical application of many other materials. In fields such as chemical engineering, energy conversion, and environmental engineering, materials often face severe chemical erosion, necessitating materials with excellent chemical stability as foundational materials, carriers, or reaction media. Silicon carbide exhibits outstanding performance under these conditions, demonstrating significant resistance to corrosive substances such as hydrochloric acid, sulfuric acid, nitric acid, and alkaline substances such as potassium hydroxide and sodium hydroxide. Despite the well-known chemical stability of silicon carbide, the stability conditions of its different types (such as 3C-, 4H-, and 6H-SiC polycrystals) in acidic and alkaline environments, as well as the specific corrosion mechanisms and differences, warrant further investigation. This Review not only delves deeply into the detailed studies related to this topic but also highlights the current applications of different silicon carbide polycrystals in chemical reaction systems, energy conversion equipment, and recycling processes. Through a comprehensive analysis, this Review aims to bridge research gaps, offering a comparative analysis of the advantages and disadvantages between different polymorphs. It provides material scientists, engineers, and developers with a thorough understanding of silicon carbide's behavior in various chemical environments. This work will propel the research and development of silicon carbide materials under extreme conditions, especially in areas where chemical stability is crucial for device performance and durability. It lays a solid foundation for ultra-high-power, high-integration, high-reliability module architectures, supercomputing chips, and highly safe long-life batteries.

2.
Angew Chem Int Ed Engl ; 62(3): e202214988, 2023 Jan 16.
Artigo em Inglês | MEDLINE | ID: mdl-36401754

RESUMO

The regulation of electron distribution of single-atomic metal sites by atomic clusters is an effective strategy to boost their intrinsic activity of oxygen reduction reaction (ORR). Herein we report the construction of single-atomic Mn sites decorated with atomic clusters by an innovative combination of post-adsorption and secondary pyrolysis. The X-ray absorption spectroscopy confirms the formation of Mn sites via Mn-N4 coordination bonding to FeMn atomic clusters (FeMnac /Mn-N4 C), which has been demonstrated theoretically to be conducive to the adsorption of molecular O2 and the break of O-O bond during the ORR process. Benefiting from the structural features above, the FeMnac /Mn-N4 C catalyst exhibits excellent ORR activity with half-wave potential of 0.79 V in 0.5 M H2 SO4 and 0.90 V in 0.1 M KOH as well as preeminent Zn-air battery performance. Such synthetic strategy may open up a route to construct highly active catalysts with tunable atomic structures for diverse applications.

3.
Am J Phys Anthropol ; 173(4): 671-696, 2020 12.
Artigo em Inglês | MEDLINE | ID: mdl-32964411

RESUMO

OBJECTIVES: Aims of the study are to initially describe and comparatively evaluate the morphology of the new Zhaoguo M1 upper limb remains, and contextualize upper limb functional adaptations among those of other worldwide Upper Paleolithic (UP) humans to make inferences about subsistence-related activity patterns in southwestern China at the Pleistocene-Holocene boundary. MATERIALS AND METHODS: The preserved Zhaoguo M1 skeletal remains include paired humeri, ulnae, and radii, among others. These specimens were scanned using micro-computed tomography to evaluate internal structural properties, while external osteometric dimensions of the Zhaoguo M1 upper limb elements also were acquired. Both sets of measurements were compared to published data on Neandertals, and Middle and Upper Paleolithic modern humans. RESULTS: The upper limb elements of Zhaoguo M1 display a suite of characteristics that generally resemble those of other contemporary Late UP (LUP) modern humans, while robusticity indices generally fall within the upper range of LUP variation. The Zhaoguo M1 upper limb elements display fewer traits resembling those of late archaic humans. The Zhaoguo M1 individual exhibits diaphyseal asymmetry in several upper limb elements suggesting left hand dominance. When evaluating the full range of magnitudes of humeral bilateral asymmetry in the comparative sample, Zhaoguo M1 falls at the lower end overall, but yet is relatively higher than contemporary LUP modern humans specifically from East Eurasia. DISCUSSION: The Zhaoguo M1 individual suggests typical LUP modern human upper limb morphology persisted in southwest China until the end of the last glacial period. Upper limb bone asymmetry of Zhaoguo M1 also indicates that behavioral activities attributed to a hunter-gatherer tradition apparently extended through the Pleistocene-Holocene transition in this region.


Assuntos
Adaptação Fisiológica/fisiologia , Úmero/anatomia & histologia , Úmero/patologia , Adulto , Animais , Sepultamento/história , Cavernas , China/etnologia , Feminino , Fósseis , História Antiga , Humanos , Masculino , Homem de Neandertal
4.
Chem Commun (Camb) ; 58(72): 10084-10087, 2022 Sep 08.
Artigo em Inglês | MEDLINE | ID: mdl-35997014

RESUMO

A facile water-activated method is developed for preparing porous graphitic carbon nitride with carbon vacancies by co-pyrolysis of melamine and water at a relatively low temperature under an Ar atmosphere, resulting in an increased specific surface area and the efficient separation of photo-generated electrons and holes. As expected, the optimal catalyst exhibited a high H2O2 yield of 180 µM within 4 h and good cycling stability. The reported template-free method may provide a reference for the preparation of high-performance photocatalysts in a facile way.

5.
Sci Rep ; 10(1): 6693, 2020 Apr 16.
Artigo em Inglês | MEDLINE | ID: mdl-32300115

RESUMO

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

6.
Oncol Rep ; 21(4): 983-7, 2009 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-19287997

RESUMO

Galectin-1 (Gal-1) is a newly found immunoregulatory carbohydrate-binding protein in cancer biology. The purpose of this study was to evaluate the effects of Gal-1 on oral squamous cell carcinoma (OSCC) development. Immunohistochemistry, Western blotting and RT-PCR were carried out in 62 primary OSCC, 38 oral leukoplakia (OPL) tissues to detect the Gal-1 expression in both protein and mRNA levels. Ten normal oral mucosa (NOM) tissues were used as control. Gal-1 protein was significantly overexpressed in OSCC cancer cells and OPL prickle cells compared to NOM (P<0.05). In accordance with Gal-1 protein, Gal-1 mRNA was also up-regulated in OSCC tissues and OPL tissues. Furthermore, both the Gal-1 protein and mRNA in OSCC tissues were higher than in OPL tissues (P<0.05). Our data supports the important roles of Gal-1 in OSCC development and suggests that Gal-1 upregulation in the OSCC and OPL tissues might be a predictor of early oral carcinogenesis.


Assuntos
Carcinoma de Células Escamosas/etiologia , Galectina 1/fisiologia , Neoplasias Bucais/etiologia , Adulto , Idoso , Western Blotting , Carcinoma de Células Escamosas/química , Carcinoma de Células Escamosas/patologia , Feminino , Galectina 1/análise , Galectina 1/genética , Humanos , Imuno-Histoquímica , Masculino , Pessoa de Meia-Idade , Neoplasias Bucais/química , Neoplasias Bucais/patologia , RNA Mensageiro/análise
7.
J Huazhong Univ Sci Technolog Med Sci ; 29(5): 659-63, 2009 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-19821105

RESUMO

This study evaluated the efficacy of rabdosia rubescens against gingivitis and compared the therapeutic efficacy of different dosage forms of rabdosia rubescens. A multi-center, randomized, double-blind, double-simulation, positive-controlled and parallel trial was conducted. A total of 136 patients exhibiting clinical symptoms of gingivitis were enrolled. The subjects were randomly assigned to two groups: test group (n=67), in which rabdosia rubescens drop pill (960 mg) and 4 tablets of simulation agent of rabdosia rubescen were orally given to the subjects three times a day for 5 days; and control group (n=69), in which the subjects were administered the tablets of rabdosia rubescens (1000 mg) and 24 drop pills of simulation agent of rabdosia rubescens thrice daily for 5 days. The experimental protocols and diagnostic criteria were established by expert panel prior to the experiment. The clinical symptoms were graded according to the severity of the disease and quantified. The total scores and scores for each clinical symptom of gingivitis were assessed at baseline and on the 6th day post-treatment. The therapeutic efficacy was compared between the two groups and in each group itself before and after the treatment. The results showed that in the two groups, the subjects who were given rabdosia rubescens, drop pill or tablet, had a decrease in total scores and scores for each clinical symptom when compared with those before treatment (P<0.01). There was significant difference in the therapeutic efficacy between the test group and the control group with the efficacy rate being 92.54% and 79.71% respectively (P<0.05). It was concluded that rabdosia rubescens showed great promise in treating gingivitis. And rabdosia rubescens drop pill was more efficacious than rabdosia rubescens tablet.


Assuntos
Medicamentos de Ervas Chinesas/uso terapêutico , Gengivite/tratamento farmacológico , Isodon/química , Fitoterapia , Adulto , Método Duplo-Cego , Medicamentos de Ervas Chinesas/administração & dosagem , Feminino , Humanos , Masculino , Resultado do Tratamento
8.
J Huazhong Univ Sci Technolog Med Sci ; 28(4): 491-4, 2008 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-18704320

RESUMO

The purpose of this study was to determine the total Bolton index (TBI) and anterior Bolton index (ABI), evaluate the clinical significance of tooth size discrepancies and the influence of gender variation of mesiodistal tooth width on Bolton Index and estimate which tooth has the greatest influence on Bolton Index. A total of 110 pairs of pretreatment dental study casts (41 male and 69 female) were selected from patients treated in Department of Orthodontics of Union Hospital in Wuhan, China. A sliding dental Vernier caliper was used for the measurement of the mesiodistal tooth width. Descriptive statistical mean values, standard deviation, standard error of the mean values, coefficient of variance and the t-test were used for the statistical analysis of the data. The study found that TBI, ABI and the total sum of teeth width had no significant difference between male and female. Male group indicated that Bolton Index (BI) was mostly influenced by the width of lower right second premolar, whereas female group showed that BI was mostly influenced by the width of both the right and left maxillary lateral incisor.


Assuntos
Má Oclusão/patologia , Odontometria/estatística & dados numéricos , Dente/anatomia & histologia , Dente Pré-Molar/patologia , China , Feminino , Humanos , Incisivo/patologia , Masculino , Má Oclusão/diagnóstico , Mandíbula/anatomia & histologia , Maxila/anatomia & histologia , Tamanho do Órgão , Fatores Sexuais , Dente/patologia
9.
Sci Rep ; 6: 32993, 2016 09 12.
Artigo em Inglês | MEDLINE | ID: mdl-27615560

RESUMO

Prolonged healing and scar formation are two major challenges in the treatment of soft tissue trauma. Adipose mesenchymal stem cells (ASCs) play an important role in tissue regeneration, and recent studies have suggested that exosomes secreted by stem cells may contribute to paracrine signaling. In this study, we investigated the roles of ASCs-derived exosomes (ASCs-Exos) in cutaneous wound healing. We found that ASCs-Exos could be taken up and internalized by fibroblasts to stimulate cell migration, proliferation and collagen synthesis in a dose-dependent manner, with increased genes expression of N-cadherin, cyclin-1, PCNA and collagen I, III. In vivo tracing experiments demonstrated that ASCs-Exos can be recruited to soft tissue wound area in a mouse skin incision model and significantly accelerated cutaneous wound healing. Histological analysis showed increased collagen I and III production by systemic administration of exosomes in the early stage of wound healing, while in the late stage, exosomes might inhibit collagen expression to reduce scar formation. Collectively, our findings indicate that ASCs-Exos can facilitate cutaneous wound healing via optimizing the characteristics of fibroblasts. Our results provide a new perspective and therapeutic strategy for the use of ASCs-Exos in soft tissue repair.


Assuntos
Exossomos/transplante , Fibroblastos/fisiologia , Células-Tronco Mesenquimais/citologia , Gordura Subcutânea/citologia , Cicatrização/fisiologia , Adolescente , Adulto , Animais , Movimento Celular , Proliferação de Células , Colágeno/metabolismo , Feminino , Fibroblastos/citologia , Humanos , Injeções Intravenosas , Masculino , Camundongos Endogâmicos BALB C , Pele/lesões
10.
PLoS One ; 11(12): e0167880, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27977721

RESUMO

BACKGROUND: Oral candidiasis (OC) is a common oral fungal infection. Recently, miconazole mucoadhesive tablets have been gaining attention for OC treatment. Despite trials in patients with human immunodeficiency virus and cancer, evidence of its application in the large-scale, general population with OC is lacking. This study aimed to evaluate the efficacy and safety of miconazole nitrate mucoadhesive tablets in comparison with itraconazole capsules for OC treatment. METHODS: The study was a randomized, open-label, parallel-armed, multicenter clinical trial. Totally, 343 patients diagnosed with OC, who met the inclusion criteria, were randomly assigned to either a treatment group that received miconazole nitrate mucoadhesive tablets (10 mg) once daily or a control group that received itraconazole capsules (100 mg QD) for 2 weeks, and were followed up for 2 weeks. The clinical cure, improvement of clinical symptoms/signs, mycologic cure, and safety were evaluated. RESULTS: The mucoadhesive tablets (n = 171) did not show inferiority to itraconazole (n = 172) in the treatment of OC. At the end of the 14-day treatment, the clinical cure rates were 45.29% and 41.76% in the miconazole and itraconazole groups, respectively (P = 0.3472). At the end of the 14-day follow-up, the clinical cure rates were 51.18% and 41.76% in the miconazole and itraconazole groups, respectively (P = 0.0329). Adverse events occurred in 53 subjects (33 in the miconazole group and 20 in the itraconazole group). There was no statistical difference in the safety profile between miconazole and itraconazole (P = 0.0533). Thrombocytopenic purpura, although rare, occurred in one patient in the miconazole group and was considered a drug-related, severe adverse event. CONCLUSION: Miconazole nitrate mucoadhesive tablets may be as effective as systemic itraconazole capsule for OC treatment. Physicians should be cautious about thrombocytopenic purpura occurring as a rare and serious adverse event of miconazole nitrate. TRIAL REGISTRATION: Chinese Clinical Trial Register ChiCTR-TRC-13003935.


Assuntos
Antifúngicos/uso terapêutico , Candidíase Bucal/tratamento farmacológico , Cápsulas/uso terapêutico , Itraconazol/uso terapêutico , Miconazol/uso terapêutico , Comprimidos/uso terapêutico , Adulto , Feminino , Humanos , Masculino , Pessoa de Meia-Idade
11.
Artigo em Inglês | MEDLINE | ID: mdl-15934325

RESUMO

The apoptosis in primary oral squamous cell carcinomas (OSCCs) without lymph node (IN) metastases and its relation with clinical stages and pathological grades was investigated. The terminal deoxynucleotidyl trasferase (TdT)-mediated dUTP nick end labeling (TUNEL) was used to detect the apoptotic cells in 15 cases of OSCCs. The percentage of apoptotic cells among tumor cells were calculated as apoptotic index (AI). The results showed that in all 15 cases of OSCCs, apoptotic cells could be visualized by TUNEL with AI ranging from 0.03 to 0.92 (average 0.32). AI was significantly negatively correlated with pathological grades (P < 0.05). It was concluded that the apoptotic rate was related to the malignant degree of OSCCs without LN metastases.


Assuntos
Apoptose/fisiologia , Carcinoma de Células Escamosas/patologia , Neoplasias Bucais/patologia , Adulto , Idoso , Feminino , Humanos , Linfonodos/patologia , Metástase Linfática , Masculino , Pessoa de Meia-Idade
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