Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 101
Filtrar
1.
Appl Microbiol Biotechnol ; 108(1): 233, 2024 Feb 24.
Artigo em Inglês | MEDLINE | ID: mdl-38400957

RESUMO

Enzyme immobilized on magnetic nanomaterials is a promising biocatalyst with efficient recovery under applied magnets. In this study, a recombinant extracellular lipase from Aspergillus niger GZUF36 (PEXANL1) expressed in Pichia pastoris GS115 was immobilized on ionic liquid-modified magnetic nano ferric oxide (Fe3O4@SiO2@ILs) via electrostatic and hydrophobic interaction. The morphology, structure, and properties of Fe3O4@SiO2@ILs and immobilized PEXANL1 were characterized by scanning electron microscopy, Fourier transform infrared spectroscopy, x-ray diffraction, vibration sample magnetometer, and zeta potential analysis. Under optimized conditions, the immobilization efficiency and activity recovery of immobilized PEXANL1 were 52 ± 2% and 122 ± 2%, respectively. The enzymatic properties of immobilized PEXANL1 were also investigated. The results showed that immobilized PEXANL1 achieved the maximum activity at pH 5.0 and 45 °C, and the lipolytic activity of immobilized PEXANL1 was more than twice that of PEXANL1. Compared to PEXANL1, immobilized PEXANL1 exhibited enhanced tolerance to temperature, metal ions, surfactants, and organic solvents. The operation stability experiments revealed that immobilized PEXANL1 maintained 86 ± 3% of its activity after 6 reaction cycles. The enhanced catalytic performance in enzyme immobilization on Fe3O4@SiO2@ILs made nanobiocatalysts a compelling choice for bio-industrial applications. Furthermore, Fe3O4@SiO2@ILs could also benefit various industrial enzymes and their practical uses. KEY POINTS: • Immobilized PEXANL1 was confirmed by SEM, FT-IR, and XRD. • The specific activity of immobilized PEXANL1 was more than twice that of PEXANL1. • Immobilized PEXANL1 had improved properties with good operational stability.


Assuntos
Líquidos Iônicos , Estabilidade Enzimática , Líquidos Iônicos/química , Aspergillus niger/genética , Aspergillus niger/metabolismo , Espectroscopia de Infravermelho com Transformada de Fourier , Dióxido de Silício/química , Lipase/metabolismo
2.
Acta Radiol ; 65(1): 41-48, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37071506

RESUMO

BACKGROUND: Computed tomography (CT) and magnetic resonance imaging (MRI) are indicated for use in preoperative planning and may complicate diagnosis and place a burden on patients with lumbar disc herniation. PURPOSE: To investigate the diagnostic potential of MRI-based synthetic CT with conventional CT in the diagnosis of lumbar disc herniation. MATERIAL AND METHODS: After obtaining prior institutional review board approval, 19 patients who underwent conventional and synthetic CT imaging were enrolled in this prospective study. Synthetic CT images were generated from the MRI data using U-net. The two sets of images were compared and analyzed qualitatively by two musculoskeletal radiologists. The images were rated on a 4-point scale to determine their subjective quality. The agreement between the conventional and synthetic images for a diagnosis of lumbar disc herniation was determined independently using the kappa statistic. The diagnostic performances of conventional and synthetic CT images were evaluated for sensitivity, specificity, and accuracy, and the consensual results based on T2-weighted imaging were employed as the reference standard. RESULTS: The inter-reader and intra-reader agreement were almost moderate for all evaluated modalities (κ = 0.57-0.79 and 0.47-0.75, respectively). The sensitivity, specificity, and accuracy for detecting lumbar disc herniation were similar for synthetic and conventional CT images (synthetic vs. conventional, reader 1: sensitivity = 91% vs. 81%, specificity = 83% vs. 100%, accuracy = 87% vs. 91%; P < 0.001; reader 2: sensitivity = 84% vs. 81%, specificity = 85% vs. 98%, accuracy = 84% vs. 90%; P < 0.001). CONCLUSION: Synthetic CT images can be used in the diagnostics of lumbar disc herniation.


Assuntos
Deslocamento do Disco Intervertebral , Humanos , Deslocamento do Disco Intervertebral/diagnóstico por imagem , Estudos Prospectivos , Estudos de Viabilidade , Vértebras Lombares/diagnóstico por imagem , Tomografia Computadorizada por Raios X/métodos , Imageamento por Ressonância Magnética/métodos
3.
Proc Natl Acad Sci U S A ; 118(30)2021 07 27.
Artigo em Inglês | MEDLINE | ID: mdl-34301886

RESUMO

Foxp3-expressing CD4+CD25+ regulatory T cells (Tregs) constitutively and highly express the immune checkpoint receptor cytotoxic T-lymphocyte-associated antigen-4 (CTLA-4), whose Treg-specific deficiency causes severe systemic autoimmunity. As a key mechanism of Treg-mediated suppression, Treg-expressed CTLA-4 down-regulates the expression of CD80/CD86 costimulatory molecules on antigen-presenting cells (APCs). Here, we show that Treg-expressed CTLA-4 facilitated Treg-APC conjugation and immune synapse formation. The immune synapses thus formed provided a stable platform whereby Tregs were able to deplete CD80/CD86 molecules on APCs by extracting them via CTLA-4-dependent trogocytosis. The depletion occurred even with Tregs solely expressing a mutant CTLA-4 form lacking the cytoplasmic portion required for its endocytosis. The CTLA-4-dependent trogocytosis of CD80/CD86 also accelerated in vitro and in vivo passive transfer of other membrane proteins and lipid molecules from APCs to Tregs without their significant reduction on the APC surface. Furthermore, CD80 down-regulation or blockade by Treg-expressed membrane CTLA-4 or soluble CTLA-4-immunoglobulin (CTLA-4-Ig), respectively, disrupted cis-CD80/programmed death ligand-1 (PD-L1) heterodimers and increased free PD-L1 on dendritic cells (DCs), expanding a phenotypically distinct population of CD80lo free PD-L1hi DCs. Thus, Tregs are able to inhibit the T cell stimulatory activity of APCs by reducing their CD80/CD86 expression via CTLA-4-dependent trogocytosis. This CD80/CD86 reduction on APCs is able to exert dual suppressive effects on T cell immune responses by limiting CD80/CD86 costimulation to naïve T cells and by increasing free PD-L1 available for the inhibition of programmed death-1 (PD-1)-expressing effector T cells. Blockade of CTLA-4 and PD-1/PD-L1 in combination may therefore synergistically hinder Treg-mediated immune suppression, thereby effectively enhancing immune responses, including tumor immunity.


Assuntos
Células Apresentadoras de Antígenos/imunologia , Antígeno B7-1/fisiologia , Antígeno B7-2/fisiologia , Antígeno B7-H1/metabolismo , Antígeno CTLA-4/fisiologia , Linfócitos T Reguladores/imunologia , Trogocitose , Animais , Antígeno B7-H1/genética , Células Dendríticas/imunologia , Feminino , Ativação Linfocitária/imunologia , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Camundongos Knockout
4.
Genet Mol Biol ; 47(1): e20230099, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38488526

RESUMO

Bougainvillea is a popular ornamental plant. Although Bougainvillea is abundant in germplasm resources, cultivars and flower colors, there is no rare blue colour varieties, due to the absence of delphinidin-based anthocyanins. This study analyzed the Bougainvillea leaf and bract transcriptome to select hosts of genetic transformation that would be suitable for the accumulation of delphinidin. A total of 36 gigabyte (GB) of raw data was obtained by transcriptome sequencing, with 4,058 significantly differentially expressed genes, including 1,854 upregulated and 2,204 downregulated genes. Annotation of these genes was performed using Gene Ontology and Kyoto Encyclopedia of Genes and Genomes databases. Through annotation, two CHS genes, one F3H gene, one DFR gene, and one F3'H gene involved in the delphinidin biosynthesis pathway were identified. The expression levels of these genes and total flavonoid content in the bracts of six Bougainvillea varieties were examined through quantitative real-time PCR and spectrophotometry, respectively. Through the comprehensive evaluation based on membership function method, the suitable host order for a blue-hued Bougainvillea transgene is Singapore White>Elizabeth Angus>Ratana Yellow>China Beauty>Orange King>Brilliant Variegata. Thus, Singapore White variety was the most appropriate transgene host for blue-hued Bougainvillea. The results of this study provide a reference for the directed breeding of blue-hued Bougainvillea.

5.
J Gen Intern Med ; 38(2): 428-433, 2023 02.
Artigo em Inglês | MEDLINE | ID: mdl-36253633

RESUMO

BACKGROUND: During the COVID-19 pandemic, the performance of Chinese doctors may have led to improved doctor-patient relationships (DPRs). However, it is unclear how doctors and patients perceived the impact of doctors' communication and empathy skills on DPRs during the COVID-19 pandemic. OBJECTIVE: To examine the perceptions of doctors and patients on how doctors' communication skills and empathy skills influence DPRs during COVID-19. MAIN MEASURES: Doctors' and patients' perceptions of doctors' communication skills were measured using the Chinese version of the SEGUE Framework. To measure empathy skills and DPRs, the Jefferson Scale of Empathy and Difficult Doctor-Patient Relationship Questionnaire were administered to doctors, and the Consultation and Relational Empathy Measure and Patient-Doctor Relationship Questionnaire were administered to patients. RESULTS: A total of 902 doctors and 1432 patients in China were recruited during the pandemic via online or offline surveys (overall response rate of 69.8%). Both doctors and patients rated doctors' empathy skills as more impactful on DPRs than communication skills. Doctors believed that only their empathy skills influenced DPRs. But patients believed that there was a significant bi-directional relationship between doctors' communication and empathy skills and these two skills interacted to directly and indirectly influence DPRs, and doctors' empathy had a greater mediating effect than their communication. CONCLUSIONS: During COVID-19, there were both similarities and differences between Chinese doctors' and patients' views on how doctors' communication and empathy skills influenced DPRs. The greater effect of doctors' empathy skills suggests that both doctors and patients attach more importance to doctors' empathy in doctor-patient interactions. The bi-directional effect on patient outcomes suggests that both doctors' communication and empathy skills are important to patients' perceptions of DPRs.


Assuntos
COVID-19 , Relações Médico-Paciente , Humanos , Empatia , Pandemias , Comunicação , Inquéritos e Questionários
6.
Zhongguo Zhong Yao Za Zhi ; 48(19): 5271-5277, 2023 Oct.
Artigo em Zh | MEDLINE | ID: mdl-38114116

RESUMO

This study explored the protective effect of astragaloside Ⅳ(AS-Ⅳ) on oxygen-glucose deprivation(OGD)-induced autophagic injury in PC12 cells and its underlying mechanism. An OGD-induced autophagic injury model in vitro was established in PC12 cells. The cells were divided into a normal group, an OGD group, low-, medium-, and high-dose AS-Ⅳ groups, and a positive drug dexmedetomidine(DEX) group. Cell viability was measured using the MTT assay. Transmission electron microscopy was used to observe autophagosomes and autolysosomes, and the MDC staining method was used to assess the fluorescence intensity of autophagosomes. Western blot was conducted to determine the relative expression levels of functional proteins LC3-Ⅱ/LC3-Ⅰ, Beclin1, p-Akt/Akt, p-mTOR/mTOR, and HIF-1α. Compared with the normal group, the OGD group exhibited a significant decrease in cell viability(P<0.01), an increase in autophagosomes(P<0.01), enhanced fluorescence intensity of autophagosomes(P<0.01), up-regulated Beclin1, LC3-Ⅱ/LC3-Ⅰ, and HIF-1α(P<0.05 or P<0.01), and down-regulated p-Akt/Akt and p-mTOR/mTOR(P<0.05 or P<0.01). Compared with the OGD group, the low-and medium-dose AS-Ⅳ groups and the DEX group showed a significant increase in cell viability(P<0.01), decreased autophagosomes(P<0.01), weakened fluorescence intensity of autophagosomes(P<0.01), down-regulated Beclin1, LC3-Ⅱ/LC3-Ⅰ, and HIF-1α(P<0.05 or P<0.01), and up-regulated p-Akt/Akt and p-mTOR/mTOR(P<0.01). AS-Ⅳ at low and medium doses exerted a protective effect against OGD-induced autophagic injury in PC12 cells by activating the Akt/mTOR pathway, subsequently influencing HIF-1α. The high-dose AS-Ⅳ group did not show a statistically significant difference compared with the OGD group. This study provides a certain target reference for the prevention and treatment of OGD-induced cellular autophagic injury by AS-Ⅳ and accumulates laboratory data for the secondary development of Astragali Radix and AS-Ⅳ.


Assuntos
Proteínas Proto-Oncogênicas c-akt , Traumatismo por Reperfusão , Ratos , Animais , Células PC12 , Proteínas Proto-Oncogênicas c-akt/genética , Glucose/uso terapêutico , Oxigênio/metabolismo , Proteína Beclina-1/genética , Proteína Beclina-1/farmacologia , Serina-Treonina Quinases TOR/genética , Serina-Treonina Quinases TOR/metabolismo , Autofagia , Apoptose , Traumatismo por Reperfusão/tratamento farmacológico
7.
World J Surg Oncol ; 20(1): 354, 2022 Nov 04.
Artigo em Inglês | MEDLINE | ID: mdl-36329458

RESUMO

OBJECTIVE: This meta-analysis aims to explore the association between angiotensin-converting enzyme (ACE) insertion/deletion (I/D) gene polymorphism and susceptibility to prostate cancer (PCa). METHODS: We searched studies related to ACE I/D polymorphism and susceptibility to PCa through PubMed, Web of Science, Embase, Cochrane Library, and Scopus databases from inception to June 1, 2022. Five gene models, including allelic, dominant, recessive, homozygote, and heterozygote models, were analyzed. The pooled odds ratio (OR) was calculated using Stata 15.0 software. Publication bias was judged by the funnel plot and Egger's test, with the robustness of the findings verified by sensitivity analysis. RESULTS: Eight published articles (including ten studies) were identified. The pooled results showed that ACE I/D locus polymorphism was significantly correlated with the risk of PCa under all gene models except for the heterozygous model (D vs. I: OR= 1.58, 95% CI: 1.14-2.21; DD vs. DI+II: OR=1.68, 95% CI: 1.11-2.54; DD+DI vs. II: OR=1.76, 95% CI: 1.11-2.80; DI vs. II: OR= 1.44, 95% CI: 0.99-2.10; DD vs. II: OR= 2.12, 95% CI: 1.15-3.93). Subgroup analysis based on genotype frequencies in the control group meeting Hardy-Weinberg equilibrium showed statistically significant differences in all gene models. The funnel plot and Egger's test indicated no publication bias. The sensitivity analysis verified the robustness of the conclusions obtained in this meta-analysis. CONCLUSION: ACE I/D locus polymorphism correlates to PCa risk. Allele D, genotype DD+DI, and DD at the ACE I/D locus increase susceptibility to PCa and can therefore serve as a potential diagnostic and screening molecular marker for PCa patients.


Assuntos
Predisposição Genética para Doença , Neoplasias da Próstata , Masculino , Humanos , Mutação INDEL , Polimorfismo Genético/genética , Peptidil Dipeptidase A/genética , Neoplasias da Próstata/genética , Angiotensinas/genética
8.
Biomed Chromatogr ; 36(11): e5462, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-35881540

RESUMO

The growing evidence has endorsed the view that therapeutic drug monitoring of caffeine for apnea of prematurity is helpful for dose tailoring when the therapeutic response is lacking or toxicity is suspected. However, plasma without caffeine is difficult to obtain. Therefore, a method was developed and validated to measure caffeine and its three primary metabolites (paraxanthine, theobromine and theophylline) using LC-ESI-MS/MS in human plasma and several surrogate matrices. The chromatographic separation of analytes was finally achieved on a Waters Symmetry C18 (4.6 × 75 mm, 3.5 µm) column. Several strategies were successfully applied to overcome the matrix effects: (a) appropriate dilution for sample cleanup; (b) a starting lower proportion of organic phase; and (c) multiple individual stable-labeled isotopic internal standards. The parallelism between the authentic matrix and surrogate matrices was convincing. The recovery of the analytes in both human plasma and rat plasma was acceptable over the linear range (0.500-50.0 µg/ml for caffeine and 0.0100-1.00 µg/ml for three metabolites). The method was successfully applied in 118 samples from 74 preterm infants with apnea of prematurity. The rat plasma or ultrapure water as a surrogate matrix is worthy of recommendation for routine therapeutic drug monitoring of caffeine.


Assuntos
Cafeína , Espectrometria de Massas em Tandem , Animais , Apneia/tratamento farmacológico , Monitoramento de Medicamentos , Humanos , Recém-Nascido , Recém-Nascido Prematuro , Ratos , Espectrometria de Massas em Tandem/métodos , Teobromina/análise , Teobromina/química , Teofilina , Água
9.
Acta Pharmacol Sin ; 42(9): 1472-1485, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-33303989

RESUMO

Celastrol is a triterpene derived from the traditional Chinese medicine Tripterygium wilfordii Hook f, which displays potential anticancer activity. In the present study, we investigated the anticancer effects of celastrol against clear cell renal cell carcinoma (ccRCC) and the underlying mechanisms. Using Cancer Genome Atlas (TCGA) database and genotype-tissue expression (GTEx) database we conducted a bioinformatics analysis, which showed that the mRNA levels of liver-X receptors α (LXRα) and ATP-binding cassette transporter A1 (ABCA1) in ccRCC tissues were significantly lower than those in adjacent normal tissues. This result was confirmed by immunoblotting analysis of 4 ccRCC clinical specimens, which showed that the protein expression of LXRα and ABCA1 was downregulated. Similar results were obtained in a panel of ccRCC cell lines (786-O, A498, SN12C, and OS-RC-2). In 786-O and SN12C cells, treatment with celastrol (0.25-2.0 µM) concentration-dependently inhibited the cell proliferation, migration, and invasion as well as the epithelial-mesenchymal transition (EMT) process. Furthermore, we demonstrated that celastrol inhibited the invasion of 786-O cells through reducing lipid accumulation; celastrol concentration-dependently promoted autophagy to reduce lipid storage. Moreover, we revealed that celastrol dramatically activated LXRα signaling, and degraded lipid droplets by inducing lipophagy in 786-O cells. Finally, celastrol promoted cholesterol efflux from 786-O cells via ABCA1. In high-fat diet-promoted ccRCC cell line 786-O xenograft model, administration of celastrol (0.25, 0.5, 1.0 mg·kg-1·d-1, for 4 weeks, i.p.) dose-dependently inhibited the tumor growth with upregulated LXRα and ABCA1 protein in tumor tissue. In conclusion, this study reveals that celastrol triggers lipophagy in ccRCC by activating LXRα, promotes ABCA1-mediated cholesterol efflux, suppresses EMT progress, and ultimately inhibits cell proliferation, migration, and invasion as well as tumor growth. Thus, our study provides evidence that celastrol can be used as a lipid metabolism-based anticancer therapeutic approach.


Assuntos
Transportador 1 de Cassete de Ligação de ATP/metabolismo , Autofagia/efeitos dos fármacos , Carcinoma de Células Renais/metabolismo , Receptores X do Fígado/metabolismo , Triterpenos Pentacíclicos/farmacologia , Transportador 1 de Cassete de Ligação de ATP/genética , Animais , Linhagem Celular Tumoral , Movimento Celular/efeitos dos fármacos , Humanos , Metabolismo dos Lipídeos/efeitos dos fármacos , Camundongos Endogâmicos BALB C , Camundongos Nus , Transdução de Sinais/efeitos dos fármacos
10.
J Clin Monit Comput ; 35(6): 1325-1332, 2021 12.
Artigo em Inglês | MEDLINE | ID: mdl-33001400

RESUMO

To develop and validate a mathematical model for predicting intracranial pressure (ICP) noninvasively using phase-contrast cine MRI (PC-MRI). We performed a retrospective analysis of PC-MRI from patients with communicating hydrocephalus (n = 138). The patients were recruited from Shenzhen Second People's Hospital between November 2017 and April 2020, and randomly allocated into training (n = 97) and independent validation (n = 41) groups. All participants underwent lumbar puncture and PC-MRI in order to evaluate ICP and cerebrospinal fluid (CSF) parameters (i.e., aqueduct diameter and flow velocity), respectively. A novel ICP-predicting model was then developed based on the nonlinear relationships between the CSF parameters, using the Levenberg-Marquardt and general global optimisation methods. There was no significant difference in baseline demographic characteristics between the training and independent validation groups. The accuracy of the model for predicting ICP was 0.899 in the training cohort (n = 97) and 0.861 in the independent validation cohort (n = 41). We obtained an ICP-predicting model that showed excellent performance in the noninvasive diagnosis of clinically significant communicating hydrocephalus.


Assuntos
Hidrocefalia , Pressão Intracraniana , Humanos , Hidrocefalia/diagnóstico por imagem , Imageamento por Ressonância Magnética , Modelos Teóricos , Estudos Retrospectivos
11.
Int J Cancer ; 147(9): 2503-2514, 2020 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-32428246

RESUMO

Chemotherapy-induced neuropathic pain is a common dose-limiting side effect of cancer treatment but the underlying mechanisms are largely unknown. Here, we used a whole-genome expression microarray and gene ontology analysis to identify the upregulation of a sequence-specific DNA-binding protein, HOXA6, in the spinal dorsal horn on Day 10 after injection of rats with oxaliplatin. Genetic disruption of HOXA6 with siRNAs alleviated mechanical allodynia after oxaliplatin administration. Reduced representation bisulfite sequencing assays indicated that oxaliplatin decreased the methylation levels of the SOX10 promoter but not of HOXA6. TET1 was also upregulated by oxaliplatin. Genetic disruption of TET1 with siRNA blocked the promoter demethylation of SOX10 and the upregulation of HOXA6 and SOX10. Importantly, inhibition of SOX10 by intrathecal application of SOX10 siRNA ameliorated the mechanical allodynia induced by oxaliplatin and downregulated the expression of HOXA6. Consistently, overexpression of SOX10 through intraspinal injection of AAV-SOX10-EGFP produced mechanical allodynia and upregulated the expression of spinal dorsal horn HOXA6. Moreover, chromatin immunoprecipitation assays demonstrated that oxaliplatin increased the binding of SOX10 to the promoter region of HOXA6. Taken together, our data suggest that HOXA6 upregulation through the TET1-mediated promoter demethylation of SOX10 may contribute to oxaliplatin-induced neuropathic pain.


Assuntos
Dioxigenases/metabolismo , Proteínas de Homeodomínio/genética , Neuralgia/genética , Oxaliplatina/efeitos adversos , Fatores de Transcrição SOXE/genética , Animais , Desmetilação do DNA/efeitos dos fármacos , Dioxigenases/genética , Modelos Animais de Doenças , Perfilação da Expressão Gênica , Humanos , Hiperalgesia/induzido quimicamente , Hiperalgesia/genética , Hiperalgesia/patologia , Injeções Espinhais , Masculino , Neuralgia/induzido quimicamente , Neuralgia/patologia , Análise de Sequência com Séries de Oligonucleotídeos , Regiões Promotoras Genéticas/genética , RNA Interferente Pequeno/administração & dosagem , RNA Interferente Pequeno/genética , Ratos , Corno Dorsal da Medula Espinal/efeitos dos fármacos , Corno Dorsal da Medula Espinal/patologia , Regulação para Cima/efeitos dos fármacos
12.
J Asian Nat Prod Res ; 22(8): 746-753, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31163996

RESUMO

Zeaxanthin dipalmitate (3) and two zeaxanthin dipalmitate derivatives, including one new compound (1), were obtained from wolfberry [the fruit of Lycium barbarum L. (Solanaceae)]. Their structures were unambiguously elucidated by spectroscopic analyses. Compound 2 is isolated from the genus Lycium for the first time, and its 1D/2D NMR data are firstly reported. All the compounds belong to carotenoids which are a kind of major bioactive constituents in wolfberry and are also responsible for wolfberry's red color.


Assuntos
Lycium , Frutas , Estrutura Molecular , Palmitatos , Xantofilas
13.
Nanotechnology ; 30(19): 195601, 2019 May 10.
Artigo em Inglês | MEDLINE | ID: mdl-30695771

RESUMO

Quantum dots/graphene (QDs/Gr) composites have become the research hotspot recently due to their unique synergistic effect as optical absorption material for next-generation electronic and optoelectronic devices. In this work, Ge QDs/Gr composite is prepared by a simple and effective ion-beam sputtering deposition technique. The intact growth evolution process is detailly investigated by means of the effect of Ge deposition amount, which will induce the enhanced crystallinity in QDs and the reduced defects in graphene. Moreover, a feasible and inspiring strategy to effectively tune doping in graphene by artificial control through changing the deposition amount of Ge atoms on graphene is demonstrated. In addition, charge transfer and interaction strength at the interface of Ge QD and graphene is influenced via the oxygen defect in the QD surface, which is consistent with field-effect transistor test and first-principle calculations. The p-doping characteristics of graphene decorated by Ge QDs may have significant application prospects in energy band engineering of graphene-based building blocks for graphene-based composite development and near-infrared detector applications.

15.
Tumour Biol ; 37(10): 14329-14330, 2016 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-27448817

RESUMO

The results of previous studies evaluated the accuracy of serum, and urinary measurements of cytokeratin-19 fragment (CYFRA 21-1) for the diagnosis of bladder cancer were inconsistent. We read with great interest the recent systematic review of diagnostic accuracy of CYFRA 21-1 for bladder cancer by Huang et al. The systematic analysis demonstrated that the pooled sensitivities and specificities for serum and urine CYFRA 21-1 were 0.42 (95 % confidence interval (CI), 0.33-0.51), 0.82 (95 % CI, 0.70-0.90), 0.94 (95 % CI, 0.90-0.96), and 0.80 (95 % CI, 0.73-0.86), respectively. Areas under the summary receiver-operating-characteristic curves for serum and urine CYFRA 21-1 were 0.88 (95 % CI, 0.85-0.91) and 0.87 (95%CI, 0.84-0.90), respectively. The authors considered that both serum and urine CYFRA 21-1 served as efficient indexes for bladder-cancer diagnosis. We congratulate and applaud their important work, but several important issues should be noted.


Assuntos
Antígenos de Neoplasias/sangue , Antígenos de Neoplasias/urina , Biomarcadores Tumorais/sangue , Biomarcadores Tumorais/urina , Queratina-19/sangue , Queratina-19/urina , Neoplasias da Bexiga Urinária/diagnóstico , Humanos , Metanálise como Assunto , Estadiamento de Neoplasias , Prognóstico , Curva ROC , Neoplasias da Bexiga Urinária/sangue , Neoplasias da Bexiga Urinária/urina
16.
Guang Pu Xue Yu Guang Pu Fen Xi ; 36(7): 2139-43, 2016 Jul.
Artigo em Zh | MEDLINE | ID: mdl-30035912

RESUMO

Spectrum denoising is an important part of spectrum detection. As we know, spectral signal is susceptible to thermal noise, mechanical vibration on site and random noise, etc. However, online monitoring systems require to reduce the impact of parameter selection caused by human operation on denoising, so a method based on singular value decomposition is proposed to denoise spectrum signal. An improved effective singular value selection method is also proposed. First, the author specify the maximum peak of the difference spectrum of singular value for the lower bound which named θ1, using the integrated information of singular value and its difference spectrum to select the upper bound, which is called θ2. The interval θ1~θ2 is defined as a fuzzy area. Then, the membership is obtained with Fuzzy C-means clusting and corresponding weight coefficients to the singular values in the fuzzy area are given. Finally, the proposed method is used to denoise UV spectrum signal with different signal to noise ratio. The signal to noise ratio, root mean square error, normalied correlation coefficient and smoothness radio are used to evaluate the result of denoising. The result shows that: based on data-driven, the proposed method has a good denoising effect, which can effectively restore the original signal.

17.
Zhonghua Yi Xue Za Zhi ; 95(13): 965-8, 2015 Apr 07.
Artigo em Zh | MEDLINE | ID: mdl-26506703

RESUMO

OBJECTIVE: To explore the influencing factors of pedicle screw instrumentation and provide theoretical rationales for decreasing facet joint violation rate by radiological evaluations of superior-segment facet joint violation after pedicle screw instrumentation in transforaminal lumbar interbody fusion (TLIF). METHODS: A retrospective study was conducted for 101 patients undergoing lumbar fusion after failed conservative treatment between December 2011 and December 2013. According to the Seo classification, computed tomography was used for evaluating the position of pedicle screw with superior segment facet joint. And χ2 test was used to examine the associations between superior segment facet joint violation and gender, age, construct level, fusion length and transpedicular screw side. RESULTS: A total of 202 screws were evaluated. There were grade 0 (n =154, 76.2%), grade 1 (n = 43, 21.3%) and grade 2 (n = 5, 2.5%). In all screws, facet joint violation occurred in L5 segment more frequently than in any other segment (P < 0.05), left-side facet joint violation was more common than right-side one (P < 0.05). No statistical associations existed between violation rates and gender, age and fusion length. CONCLUSION: During TLIF, there is a higher incidence of facet joint violation at right side and in L5 segment compared with other lumbar segments.


Assuntos
Vértebras Lombares , Fusão Vertebral , Humanos , Incidência , Região Lombossacral , Parafusos Pediculares , Estudos Retrospectivos , Tomografia Computadorizada por Raios X , Articulação Zigapofisária
18.
Neurol Neurochir Pol ; 49(2): 99-106, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25890924

RESUMO

OBJECT: To explore the clinical feasibility of employing occlusion to treat basilar artery dissecting aneurysm. METHODS: One patient, male and 46 years old, suffered transient numbness and weakness on the right limbs. Cerebral angiography indicated basilar artery dissecting aneurysm. The patient underwent the stent-assisted coil embolization of aneurysm and the result is satisfactory. Digital subtraction angiography (DSA) reviews were performed at 1 month and 4.5 months, respectively after the operation and indicate that the basilar artery is unobstructed and there was no recurrence of the aneurysm. DSA review 1 year after the first treatment indicates the aneurysm recurrence, stent-assisted coils dense embolization of aneurysm was performed again and the result was satisfactory. Ten months after the second operation, DSA review found the basilar artery aneurysm recurrence again and occlusion of the basilar artery was performed. RESULTS: The basilar artery occlusion was effective. The bilateral posterior inferior cerebellar arteries and the bilateral posterior cerebral arteries are unobstructed. Five months of follow-up found that the patient recovered well. DSA reviews performed 5 months after occlusion indicate no recurrence of the aneurysm. CONCLUSIONS: Occlusion to treat basilar artery dissecting aneurysm is clinically feasible, but surgical indications should be considered strictly.


Assuntos
Embolização Terapêutica/métodos , Procedimentos Endovasculares/métodos , Aneurisma Intracraniano/cirurgia , Insuficiência Vertebrobasilar/cirurgia , Angiografia Cerebral , Diplopia/etiologia , Humanos , Masculino , Pessoa de Meia-Idade , Recidiva , Reoperação , Stents , Resultado do Tratamento
19.
Guang Pu Xue Yu Guang Pu Fen Xi ; 35(2): 438-42, 2015 Feb.
Artigo em Zh | MEDLINE | ID: mdl-25970908

RESUMO

As the basis of accurate diagnosis, fault early-warning of gas insulation switchgear (GIS) focuses on the time-effectiveness and the applicability. It would be significant to research the method of unified early-warning for partial discharge (PD) and overheated faults in GIS. In the present paper, SO2 is proposed as the common and typical by-product. The unified monitoring could be achieved through ultraviolet spectroscopy (UV) detection of SO2. The derivative method and Savitzky-Golay filtering are employed for baseline correction and smoothing. The wavelength range of 290-310 nm is selected for quantitative detection of SO2. Through UV method, the spectral interference of SF6 and other complex by-products, e.g., SOF2 and SOF2, can be avoided and the features of trace SO2 in GIS can be extracted. The detection system is featured by compacted structure, low maintenance and satisfactory suitability in filed surveillance. By conducting SF6 decomposition experiments, including two types of PD faults and the overheated faults between 200-400 degrees C, the feasibility of proposed UV method has been verified. Fourier transform infrared spectroscopy and gas chromatography methods can be used for subsequent fault diagnosis. The different decomposition features in two kinds of faults are confirmed and the diagnosis strategy has been briefly analyzed. The main by-products under PD are SOF2 and SO2F2. The generated SO2 is significantly less than SOF2. More carbonous by-products will be generated when PD involves epoxy. By contrast, when the material of heater is stainless steel, SF6 decomposes at about 300 "C and the main by-products in overheated faults are SO2 and SO2F2. When heated over 350 degrees C, SO2 is generated much faster. SOz content stably increases when the GIS fault lasts. The faults types could be preliminarily identified based on the generation features of SO2.

20.
J Environ Sci (China) ; 26(10): 2131-7, 2014 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-25288558

RESUMO

Food has been documented as one of major routes for human exposure to environmental estrogens (EEs), but information on the occurrence of EEs in animal foodstuffs is still scarce. This study analyzed estrogenic activity in 16 types of animal foodstuffs (n=142) collected from four cities (Wuhan, Guangzhou, Wenzhou and Yantai) of China by combined yeast estrogen screen (YES) bioassay and chemical analysis. By bioassay, all samples' extracts were found to induce estrogenic activities and the bioassay-derived 17ß-estradiol equivalent (EEQbio) ranged from 8.29 to 118.32ng/g. In addition, the samples were analyzed by liquid chromatography coupled to tandem mass spectrometry for further chemical analysis. 17ß-Estradiol was found in all samples in this survey at levels of 0.44 to 15.04ng/g. All samples had 33.1% detection rate of 17α-ethinylestradiol (EE2), and the maximum concentration was 2.80ng/g. Bisphenol A and 4-nonylphenols were detected in 83.8% and 83.1% of samples, with concentrations up to 12.56ng/g and 35.76ng/g, respectively. However, the concentrations of estrone, diethylstilbestrol and 4-t-octylphenol were found to be below the limit of detection. A comparison of EEQbio measured from the YES assay and EEQchem calculated from chemical analysis showed good correlation (R(2)=0.84). Based on the results, the YES assay can be used as a rapid pre-screening method for monitoring the levels of estrogenic activity in large numbers of animal foodstuffs, and chemical analysis used in combination can be used for the identification of specific EEs.


Assuntos
Ração Animal/análise , Disruptores Endócrinos/análise , Estrogênios/química , Bioensaio , China , Cromatografia Líquida , Espectrometria de Massas em Tandem
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA