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1.
Clin Lab ; 70(4)2024 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-38623667

RESUMO

BACKGROUND: This study aims to investigate the application value of serum cytokeratin 19 fragment (CYFRA21-1) combined with nerve-specific enolase (NSE), carcinoembryonic antigen (CEA), and squamous cell carcinoma antigen (SCC-Ag) in the diagnosis of lung cancer (LC). METHODS: A total of 831 cases of LC, 360 cases of benign lung disease (BLD) and 102 healthy controls, were enrolled. The data were processed using SPSS, GraphPad Prism, and MedCalc software. RESULTS: The tumor marker (TM) levels in the LC and BLD groups were significantly higher than those in the control group; the CYFRA21-1, NSE, and CEA levels in the patients with LC were higher than in those with BLD. In particular, the increase was predominantly observed for the levels of CEA and CYFRA21-1 in adenocarcinoma (LUAD), CYFRA21-1 and SCC-Ag in squamous cell carcinoma (LUSC), and NSE in small cell carcinoma (SCLC). The CYFRA21-1, NSE, and CEA levels were significantly higher in stage IV than in other stages in LC. Univariate binary logistic analysis showed that increased levels of all four TMs were risk factors for BLD and LC. The area under the curve (AUC) of CYFRA21-1 was most effective in distinguishing patients with BLD or LC from the controls and in distinguishing patients with BLD and LC. The AUCs of combined CYFRA21-1, NSE, and CEA were increased to 0.755, 0.922, and 0.783, respectively, with no significant difference with the AUC of the four combined tests. In the histological classification, the best predictors were CEA, for LUAD, CYFRA21-1 for LUSC, and NSE for SCLC. Moreover, the expression levels of CYFRA21-1, NSE, and CEA significantly decreased after each treatment course. CONCLUSIONS: The combined assay of CYFRA21-1, NSE, and CEA addresses the aspects of accuracy, sensitivity, specificity, and economic cost and should be considered as a potential diagnostic test in LC.


Assuntos
Neoplasias Pulmonares , Serpinas , Carcinoma de Pequenas Células do Pulmão , Humanos , Neoplasias Pulmonares/diagnóstico , Antígeno Carcinoembrionário , Biomarcadores Tumorais , Antígenos de Neoplasias , Queratina-19 , Carcinoma de Pequenas Células do Pulmão/diagnóstico , Fosfopiruvato Hidratase
2.
Surgeon ; 19(5): 268-278, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32859508

RESUMO

OBJECTIVE: To compare clinical and imaging findings between extreme lateral lumbar interbody fusion (XLIF) and posterior fusion (PF) via meta-analysis for the treatment of lumbar degenerative diseases. METHODS: English papers reporting clinical and imaging findings for the treatment of lumbar degenerative diseases with XLIF and PF published electronically in the PubMed, Embase, Cochrane Library, and Web of Science databases from January 2006 to August 2019 were retrieved. Two authors independently extracted data and evaluated the quality of the included literature. Meta-analysis of outcome measures was performed using Stata 14 and RevMan 5.3 software. RESULTS: This meta-analysis included 744 patients from nine studies, two of which were prospective studies, while the others were retrospective studies. The quality of each study was determined to be high. The meta-analysis showed no significant differences in the operative time, length of hospital stay, clinical effectiveness, and improvement in postoperative global sagittal alignment between two approaches (P > 0.05). However, XLIF was significantly better than PF in reducing intraoperative blood loss and recovery of local sagittal alignment (P < 0.05). Moreover, the high incidence of postoperative complications were detected in XLIF group (P < 0.05). CONCLUSIONS: Both surgical approaches have equally promising clinical effectiveness for the treatment of lumbar degenerative diseases. Although XLIF can reduce intraoperative blood loss and obtain better postoperative local sagittal alignment than PF, the high incidence of postoperative complications should prompt us to consider why XLIF procedure is still being offered to our patients and how we can reduce these complications. In addition, any conclusions should be taken with caution because of the mix of prospective and retrospective studies, and the high heterogeneity and bias.


Assuntos
Vértebras Lombares , Fusão Vertebral , Humanos , Vértebras Lombares/diagnóstico por imagem , Vértebras Lombares/cirurgia , Estudos Prospectivos , Estudos Retrospectivos , Resultado do Tratamento
3.
J Clin Lab Anal ; 34(5): e23159, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-31916308

RESUMO

BACKGROUND: Tandem mass spectrometry is a powerful technology available in China over the last 15 years. The development of tandem mass spectrometry had made it possible to rapidly screen newborns for inborn errors of metabolism. The aim of this study was to determine the birth incidence of inborn errors of metabolism through expanded screening of newborns by tandem mass spectrometry in Xinxiang area. METHODS: Dried blood spots from 50 112 newborns were assessed for inborn errors of metabolism by tandem mass spectrometry. The diagnoses were confirmed based on the clinical features, conventional laboratory tests, and the organic acid levels tested in urine by gas chromatography-mass spectrometry. RESULTS: The study findings revealed that 31 newborns were diagnosed with inborn errors of metabolism. The total incidence rate of inborn errors of metabolism was 1/1617, and these included 16 cases of amino acid disorders (51.6%), nine cases of organic acid disorders (29.0%), and 6 (19.4%) cases of fatty acid beta-oxidation disorders. CONCLUSIONS: The screening for the incidence of inborn errors of metabolism in Xinxiang area showed that the rate was higher than previously reported. This study provides valuable data which may be useful in facilitating improvements in the expansion of screening to enable early diagnosis and treatment of inborn errors of metabolism before the onset of symptoms.


Assuntos
Erros Inatos do Metabolismo/diagnóstico , Triagem Neonatal/métodos , Espectrometria de Massas em Tandem/métodos , Aminoácidos/metabolismo , China/epidemiologia , Ácidos Graxos/metabolismo , Feminino , Humanos , Incidência , Recém-Nascido , Masculino , Erros Inatos do Metabolismo/epidemiologia
4.
Eur Spine J ; 29(7): 1505-1517, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-31872301

RESUMO

PURPOSE: The aim of this study is to investigate, using a meta-analysis, differences in safety and effectiveness between a titanium mesh bone graft and bone graft alone for the treatment of thoracolumbar spinal tuberculosis. METHODS: PubMed, Web of Science, Cochrane Library, Chinese National Knowledge Infrastructure, Wanfang (Chinese) and other databases were searched up to April 2019 using predetermined terms. Published studies investigating the safety and effectiveness of a titanium mesh bone graft versus a bone graft alone for the treatment of thoracolumbar spinal tuberculosis were included. Two authors independently extracted the data and evaluated the quality of the included articles. A meta-analysis of relevant outcome indicators was performed using Stata 14 and RevMan 5.3 software. RESULTS: We retrieved 8 retrospective studies that met the inclusion criteria and enrolled a total of 401 patients, including 203 patients in the titanium mesh group and 198 in the bone graft only group. Each study was rated as high quality. The meta-analysis results showed no statistically significant differences between the 2 bone graft methods in terms of surgery-related indicators, clinical effectiveness, imaging and complications. CONCLUSIONS: Both titanium mesh and bone grafts alone are effective for the treatment of thoracolumbar spinal tuberculosis based on safety. However, the results of this study do not support the superiority of titanium mesh bone grafts reported in previous studies. Because of the high risk of bias of the conclusions of a meta-analysis of non-randomized studies and the small sample sizes for some of the most important outcomes, randomized controlled trials are expected to further examine the reliability of the present findings.


Assuntos
Transplante Ósseo , Telas Cirúrgicas , Titânio , Tuberculose da Coluna Vertebral/cirurgia , Materiais Biocompatíveis , Transplante Ósseo/métodos , Humanos , Vértebras Lombares/cirurgia , Implantação de Prótese , Reprodutibilidade dos Testes , Estudos Retrospectivos , Vértebras Torácicas/cirurgia , Resultado do Tratamento
7.
Talanta ; 264: 124745, 2023 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-37290332

RESUMO

Liquid chromatography-mass spectrometry (LC-MS) is a platform for urine and blood sample analysis. However, the high variability in the urine sample reduced the confidence of metabolite identification. Therefore, pre and post-calibration operations are inevitable to ensure an accurate urine biomarker analysis. In this study, the phenomenon of a higher creatinine concentration variable in ureteropelvic junction obstruction (UPJO) patient urine samples than in healthy people was revealed, indicating the urine biomarker discovery of UPJO patients is not adapted to the creatinine calibrate strategy. Therefore, we proposed a pipeline "OSCA-Finder" to reshape the urine biomarker analysis. First, to ensure a more stable peak shape and total ion chromatography, we applied the product of osmotic pressure and injection volume as a calibration principle and integrated it with an online mixer dilution. Therefore, we obtained the most peaks and identified more metabolites in a urine sample with peak area group CV<30%. A data-enhanced strategy was applied to reduce the overfit while training a neural network binary classifier with an accuracy of 99.9%. Finally, seven accurate urine biomarkers combined with a binary classifier were applied to distinguish UPJO patients from healthy people. The results show that the UPJO diagnostic strategy based on urine osmotic pressure calibration has more potential than ordinary strategies.


Assuntos
Aprendizado Profundo , Nefropatias , Obstrução Ureteral , Humanos , Creatinina/urina , Metabolômica/métodos , Biomarcadores/urina , Obstrução Ureteral/cirurgia , Obstrução Ureteral/urina
8.
Nanotechnology ; 22(30): 305606, 2011 Jul 29.
Artigo em Inglês | MEDLINE | ID: mdl-21719973

RESUMO

We report in situ observations of the growth of endotaxial CoSi(2) nanowires on Si(110) using an ultrahigh vacuum transmission electron microscope with a miniature electron-beam deposition system located above the pole-piece of the objective lens. Metal deposition at 750-850 °C results in formation of coherently strained silicide nanowires with a fixed length/width (L/W) aspect ratio that depends strongly on temperature. Both dimensions evolve with time as L, W ∼ t(1/3). To explain this behavior, we propose a fixed-shape growth mode based on thermally activated facet-dependent reactions. A second growth mode is also observed at 850 °C, with dimensions that evolve as L ∼ t and W ∼ constant. This mode is accompanied by formation of an array of dislocations. We expect that other endotaxial nanowire systems will follow coherently strained growth modes with similar geometrical constraints, as well as dislocated growth modes with different growth kinetics.

9.
Se Pu ; 39(4): 391-398, 2021 Apr 08.
Artigo em Zh | MEDLINE | ID: mdl-34227759

RESUMO

Urine is an important source of biomolecular information for metabolomic studies. However, the acquisition of high-quality metabolomic datasets or reliable biomarkers from urine is difficult owing to the large variations in the concentrations of endogenous metabolites in the biofluid, which are caused by diverse factors such as water consumption, drugs, and diseases. Thus, normalization or calibration is essential in urine metabolomics for eliminating such deviations. The urine osmolality (Π), which is a direct measure of the total urinary solute concentration and is not affected by circadian rhythms, diet, gender, and age, is often considered the gold standard for estimation of the urine concentration. In this study, a pre-data acquisition calibration strategy based on osmolality was investigated for its feasibility to overcome sample concentration variability. Before data acquisition, the product of the osmolality×injection volume of all samples was set to be equivalent through the uses of a customized injection volume or dilution. After ultra performance liquid chromatography-high resolution mass spectrometry (UPLC-HRMS) analysis of the sample, the raw dataset was normalized to the total ion abundance or total useful MS signals (MSTUS) to achieve further calibration. The osmolality of each urine sample was determined with a freezing-point depression osmometer. For the instrumental analysis, a Vanquish UPLC system coupled to a Q-Exactive Plus HRMS device was used for metabolite analysis and accurate mass measurement. Full-scan mass spectra were acquired in the range of m/z 60-900, and the MS/MS experiments were conducted in "Top5" data-dependent mode. A Waters UPLC column (100 mm×2.1 mm, 1.8 µm) was used for chromatography separation. The raw data were imported into Progenesis QI software for peak picking, alignment, deconvolution, and normalization. SIMCA-P software was used for the principal component analysis (PCA) and orthogonal partial least-squares discrimination analysis (OPLS-DA). This strategy was first applied to sequentially diluted urine samples, where three frequently used normalization methods were compared. In the identical injection volume experiment, the points were scattered and showed relevant distribution according to the dilution multiple in the plot of PCA scores. There was little improvement after normalization to either the total ion abundance or MSTUS. In the customized injection volume experiment, the urine samples derived from the same source showed ideal clustering. With total ion abundance and MSTUS normalization, the dataset was further improved in the PCA model fitting and prediction. As a result, there were more peaks with a peak area RSD of <30%, which indicated better parallelism. The diluted urine solutions had higher Spearman's coefficient values with their sample source than those without calibration, which suggested less intra-group differences. The strategy was further validated using data from a metabolomic study of children with congenital hydronephrosis and healthy controls. As a concentration estimator, osmolality showed better linear correlation with the mass signal and was less influenced by physiological or pathological factors, thus obtaining broader application and more accurate results than creatinine. The concentration variability was effectively eliminated after customized dilution calibration and showed a more obvious clustering effect in the PCA score plot. The OPLS-DA-based statistical model used to identify discriminate metabolites was improved, with less chance of overfitting. In conclusion, the calibration strategy based on osmolality combined with total ion abundance or MSTUS normalization significantly overcame the problem of urine concentration variability, eliminated intra-group differences, and possessed better parallelism, thus giving better clustering effects in PCA or OPLS-DA and higher reliability of the statistical model. The results of this study provide guidance and a reference for future metabolomic studies on urine.


Assuntos
Hidronefrose/urina , Metabolômica , Urinálise , Calibragem , Criança , Cromatografia Líquida de Alta Pressão , Humanos , Hidronefrose/congênito , Concentração Osmolar , Reprodutibilidade dos Testes , Espectrometria de Massas em Tandem
10.
Clin Chim Acta ; 517: 23-30, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-33607070

RESUMO

AIMS: To investigate a family with clinical symptoms of maple syrup urine disease and reveal a genetic cause underlying this disease. METHODS: Targeted capture sequencing was used to screen for mutations in the patient. Real-Time PCR was carried out to perform exon 1, 5, 9 CNV analysis of samples from the patient's father, mother and sister. Whole genome sequencing was performed to map the approximate location of the break points of the gross deletion. Long-range PCR and Sanger sequencing were performed to identify the length of the deletion and to locate the break points. RESULTS: The patient is a compound heterozygous mutation including a small deletion mutation (c.1227_1229del chr19: 41930402) and a gross novel deletion including exon1-9 in BCKDHA. The junction site of the gross deletion was localized within a microhomologous sequence in two Alu elements. CONCLUSIONS: This study is the first time report on rearrangement sequences in BCKDHA mediated by Alu element, which resulted in MSUD. Our results may also offer new insights into the formation and pathogenicity of MSUD, and may be useful to genetic counseling and genetic testing.


Assuntos
Doença da Urina de Xarope de Bordo , Éxons/genética , Humanos , Doença da Urina de Xarope de Bordo/genética , Mutação , Reação em Cadeia da Polimerase , Sequenciamento Completo do Genoma
11.
Se Pu ; 38(8): 914-922, 2020 Aug 08.
Artigo em Zh | MEDLINE | ID: mdl-34213183

RESUMO

Archaea are single-cell microorganisms, structurally and biochemically similar to bacteria and fungi. Most of them live in extreme environments, such as high salt, extremely acidic, extremely hot, and anaerobicenvironments. The membrane structure and related metabolic pathways of archaea are different from those of other microorganisms. Therefore, studying the lipid metabolism of archaea is of great significance for exploring the life activities in extreme environments. As the first step in lipidomic analysis, lipid extraction and pretreatment methods play an important role, as they influence the accuracy and reliability of the final results. We harnessed ultra-performance liquid chromatography coupled with high-resolution mass spectrometry (UPLC-HRMS) to detect the total normal lipids. The hyperthermophilic archaeon Pyrococcus yayanosii was selected as the model. The Bligh-Dyer acidic method, Folch method, methyl tert-butyl ether (MTBE) method, and solid-phase extraction (SPE) method were compared by multi-component analysis in terms of extraction efficiency, reproducibility, and extraction discrimination. Comprehensive analysis revealed that the SPE and MTBE methods showed the best extraction repeatability and extraction efficiency, and were suitable for high-throughput microbial lipid extraction. Finally, normal lipid components of P. yayanosii were comprehensively analyzed by SPE coupled with UPLC-HRMS. A total of 1402 lipid components were identified. This article aims to provide a reference for non-targeted lipidomic analysis of archaea and other microorganisms towards understanding their lipid metabolism.


Assuntos
Archaea , Lipidômica , Lipídeos/análise , Archaea/química , Cromatografia Líquida de Alta Pressão , Espectrometria de Massas , Pyrococcus/química , Reprodutibilidade dos Testes
12.
J Clin Endocrinol Metab ; 105(3)2020 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-31930294

RESUMO

CONTEXT: Metabolic disorders, especially dysregulated lipid metabolism, increase the risk of cardiovascular mortality in acromegaly. Previous studies measuring plasma macromolecular lipids have yielded conflicting results. PURPOSE: To explore the plasma lipid metabolite profiles by metabolomics analysis and identify potential metabolites associated with cardiac function in acromegaly. METHODS: Plasma was obtained from 80 newly diagnosed, untreated patients with acromegaly and 80 healthy controls. Echocardiography was performed. Based on the results of an oral glucose tolerance test (OGTT), patients were categorized into 2 groups: normal glucose tolerance (NGT, n = 28) and impaired glucose tolerance or diabetes mellitus (IGT/DM, n = 52). High-performance liquid chromatography-mass spectrometry (HPLC-MS)-based metabolomics analysis was conducted. Data were processed by principal components analysis (PCA), orthogonal partial least square-discriminant analysis (OPLS-DA), and MetaboAnalyst 4.0. Associations between metabolic substances and cardiovascular parameters were also explored. RESULTS: Metabolomics uncovered a distinct metabolic pattern between acromegaly and healthy controls, and perturbed pathways mainly include glycerophospholipid metabolism, sphingolipid metabolism, as well as linoleic acid metabolism. Collective analysis showed that phosphatidylethanolamine (PE) (22:6/16:0) was positively correlated with LV mass, while lysophosphatidylcholine (LysoPC) (16:0) was positively correlated with fractional shortening (FS) and left ventricle ejection fraction (LVEF). CONCLUSION: Patients with acromegaly have distinct lipid metabolite profiling, while PE (22:6/16:0) and LysoPC (16:0) are correlated with cardiac structure and function, which may contribute to the risk of cardiovascular complications.


Assuntos
Acromegalia/sangue , Lipídeos/sangue , Espectrometria de Massas/métodos , Metaboloma , Acromegalia/complicações , Acromegalia/diagnóstico por imagem , Acromegalia/metabolismo , Adulto , Biomarcadores/sangue , Doenças Cardiovasculares/sangue , Doenças Cardiovasculares/diagnóstico , Doenças Cardiovasculares/etiologia , Estudos de Casos e Controles , Cromatografia Líquida de Alta Pressão , Complicações do Diabetes/sangue , Complicações do Diabetes/diagnóstico por imagem , Diabetes Mellitus/sangue , Diabetes Mellitus/diagnóstico por imagem , Ecocardiografia , Feminino , Intolerância à Glucose/sangue , Intolerância à Glucose/complicações , Intolerância à Glucose/diagnóstico por imagem , Teste de Tolerância a Glucose , Humanos , Metabolismo dos Lipídeos , Transtornos do Metabolismo dos Lipídeos/sangue , Transtornos do Metabolismo dos Lipídeos/complicações , Transtornos do Metabolismo dos Lipídeos/diagnóstico por imagem , Lipídeos/análise , Masculino , Metabolômica/métodos , Pessoa de Meia-Idade
13.
J Asian Nat Prod Res ; 11(8): 693-7, 2009 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-20183309

RESUMO

Two new ent-kaurane diterpenoids, dayecrystals D-E (1-2), together with nine known compounds, isojaponin A (3), rabdosin A (4), lushanrubescensin J (5), wikstroemioidin B (6), maoyecrystal C (7), rabdosin B (8), isodonal (9), shikokianin (10), and effusanin A (11), were isolated from the leaves of Isodon macrophyllus. The structures of the new compounds were elucidated using 1D and 2D NMR spectroscopy. The (13)C-NMR spectral data of compound 4 are reported for the first time. All of the compounds were tested for their cytotoxicities against DU145 and LoVo human tumor cells. Compounds 4, 10, and 11 showed inhibitory effects on DU145 cells with IC(50) values 5.90, 4.24, and 3.16 microM, and LoVo cells with IC(50) values 14.20, 17.55, and 3.02 microM, respectively.


Assuntos
Antineoplásicos Fitogênicos/isolamento & purificação , Antineoplásicos Fitogênicos/farmacologia , Diterpenos/isolamento & purificação , Diterpenos/farmacologia , Medicamentos de Ervas Chinesas/isolamento & purificação , Medicamentos de Ervas Chinesas/farmacologia , Isodon/química , Antineoplásicos Fitogênicos/química , Diterpenos/química , Ensaios de Seleção de Medicamentos Antitumorais , Medicamentos de Ervas Chinesas/química , Humanos , Concentração Inibidora 50 , Estrutura Molecular , Folhas de Planta/química
14.
J Orthop Surg Res ; 14(1): 469, 2019 Dec 30.
Artigo em Inglês | MEDLINE | ID: mdl-31884957

RESUMO

BACKGROUND: To systematically compare the short- to midterm effectiveness of stemless prostheses to that of stemmed prostheses for patients who underwent total shoulder arthroplasty (TSA) and to provide a guideline for clinical decision-making. METHODS: PubMed, the Cochrane Library, and Web of Science were searched with the given search terms until July 2019 to identify published articles evaluating the clinical outcomes for stemless prostheses compared with stemmed prostheses for patients who underwent TSA. Data extraction and the quality assessment of the included studies were independently performed by two authors. Stata software 14.0 was used to analyze and synthesize the data. RESULTS: Two randomized controlled trials and six case-controlled studies with a total of 347 shoulders were included in this meta-analysis. The results of this meta-analysis showed that there were no significant differences between the stemless and stemmed prostheses in terms of the Constant score, pain score, strength, activities of daily living, postoperative range of motion (ROM), and postoperative maximum active ROM. CONCLUSIONS: This is the first meta-analysis reporting the clinical results of stemless TSA in the short- to midterm follow-up period. Both types of shoulder prostheses were similar in achieving satisfactory clinical outcomes.


Assuntos
Artroplastia do Ombro , Desenho de Prótese , Prótese de Ombro , Artroplastia do Ombro/métodos , Estudos de Casos e Controles , Tomada de Decisão Clínica , Humanos , Guias de Prática Clínica como Assunto , Ensaios Clínicos Controlados Aleatórios como Assunto , Fatores de Tempo , Resultado do Tratamento
15.
Zhong Yao Cai ; 30(7): 794-6, 2007 Jul.
Artigo em Zh | MEDLINE | ID: mdl-17944187

RESUMO

OBJECTIVE: To study the chemical constituents of Isodon macrophyllus. METHODS: Compounds were spearated and purified by silica gel column chromatography and their structures were elucidated on the basis of spectral data and chemical evidences. RESULTS: Six compounds were obtained from EtOAc extract of leaves of Isodon macroplhllus and identified as rabdophyllin H(I), lushan-ruhescensins F(II), maovecrystal J(III), Taibaijap onicain A(IV), rabdosinate(V), dancostero(VI). CONCLUSION: Co mpounds II-IV were isolated from this plant for the first time.


Assuntos
Diterpenos/isolamento & purificação , Isodon/química , Plantas Medicinais/química , Diterpenos/química , Diterpenos do Tipo Caurano/química , Diterpenos do Tipo Caurano/isolamento & purificação , Espectroscopia de Ressonância Magnética/métodos , Estrutura Molecular , Extratos Vegetais/química , Extratos Vegetais/isolamento & purificação , Folhas de Planta/química , Sitosteroides/química , Sitosteroides/isolamento & purificação
18.
Phys Rev Lett ; 93(25): 256102, 2004 Dec 17.
Artigo em Inglês | MEDLINE | ID: mdl-15697916

RESUMO

We demonstrate the growth of self-assembled nanowires of cobalt silicide on Si(111), (100), and (110) substrates during deposition of Co onto a heated Si substrate. Silicide islands form via an endotaxial mechanism, growing into the substrate along inclined Si{111} planes, which breaks the symmetry of the surface and leads to a long, thin nanowire shape. During growth, both the length and width of the islands increase with time in a fixed proportion that varies strongly with growth temperature, which shows that the nanowire shape is kinetically determined. It is expected that nanowires could form in many other overlayer/substrate systems via this mechanism.

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