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1.
Anal Chem ; 95(45): 16639-16648, 2023 11 14.
Artigo em Inglês | MEDLINE | ID: mdl-37910128

RESUMO

The simultaneous detection of multiple antibiotic residues in food is of great significance for food safety. In this work, a novel dual-potential electrochemiluminescence (ECL) immunoassay was designed for the simultaneous detection of chloramphenicol and fluorfenicol residues in food. Ru@MOF was used as an anodic probe, and SnS2 QDs-PEI-Au-MoS2 was used as a cathodic probe. Notably, the coreactant for both luminophores was K2S2O8, avoiding interactions caused by different kinds of coreactants. Au nanoparticles functionalized with a nitrogen- and sulfur-doped graphene oxide-modified glassy carbon electrode to improve the electron transfer efficiency and provide a larger surface area for immobilization of antigen. The linear range for the detection of florfenicol was determined to be 0.1-1000 ng mL-1 with a detection limit of 0.03 ng mL-1, and the linear range for the detection of chloramphenicol was 0.01-1000 ng mL-1 with a detection limit of 3.2 pg mL-1 by recording the ECL responses at two different excitation potentials. The proposed immunoassay achieved a more stable recovery in the detection of actual samples and provided a new analytical method for the simultaneous detection of florfenicol and chloramphenicol residues with high sensitivity and specificity.


Assuntos
Técnicas Biossensoriais , Nanopartículas Metálicas , Cloranfenicol , Técnicas Eletroquímicas/métodos , Nanopartículas Metálicas/química , Ouro/química , Imunoensaio/métodos , Medições Luminescentes/métodos , Técnicas Biossensoriais/métodos , Limite de Detecção
2.
J Magn Reson Imaging ; 2023 Nov 07.
Artigo em Inglês | MEDLINE | ID: mdl-37933890

RESUMO

BACKGROUND: Breast MRI has been recommended as supplemental screening tool to mammography and breast ultrasound of breast cancer by international guidelines, but its long examination time and use of contrast material remains concerning. PURPOSE: To develop an unenhanced radiomics model with using non-gadolinium based sequences for detecting breast cancer based on T2-weighted (T2W) and diffusion-weighted (DW) MRI. STUDY TYPE: Retrospective analysis followed by retrospective and prospective cohorts study. POPULATION: 1760 patients: Of these, 1293 for model construction (n = 775 for training and 518 for validation). The remaining patients for model testing in internal retrospective (n = 167), internal prospective (n = 188), and external retrospective (n = 112) cohorts. FIELD STRENGTH/SEQUENCE: 3.0T MR scanners from two institution. T2WI, DWI, and first contrast-enhanced T1-weighted sequence. ASSESSMENT: AUCs in distinguishing breast cancer were compared between combined model with gadolinium agent sequence and unenhanced model. Subsequently, the AUCs in testing cohorts of unenhanced model was compared with two radiologists' diagnosis for this research. Finally, patient subgroup analysis in testing cohorts was performed based on clinical subgroups and different types of malignancies. STATISTICAL TESTS: Mann-Whitney U test, Kruskal-Wallis H test, chi-square test, weighted kappa test, and DeLong's test. RESULTS: The unenhanced radiomics model performed best under Gaussian process (GP) classifiers (AUC: training, 0.893; validation, 0.848) compared to support vector machine (SVM) and logistic, showing favorable prediction in testing cohorts (AUCs, 0.818-0.840). The AUCs for the unenhanced radiomics model were not statistically different in five cohorts from those of the combined radiomics model (P, 0.317-0.816), as well as the two radiologists (P, 0.181-0.918). The unenhanced radiomics model was least successful in identifying ductal carcinoma in situ, whereas did not show statistical significance in other subgroups. DATA CONCLUSION: An unenhanced radiomics model based on T2WI and DWI has comparable diagnostic accuracy to the combined model using the gadolinium agent. LEVEL OF EVIDENCE: 4 TECHNICAL EFFICACY: Stage 2.

3.
Analyst ; 148(22): 5691-5697, 2023 Nov 06.
Artigo em Inglês | MEDLINE | ID: mdl-37823327

RESUMO

In this study, a novel electrochemiluminescence resonance energy transfer (ECL-RET) immunoassay was developed for the first time for the detection of zearalenone (ZEN). A porphyrin metal-organic framework (PCN-222), an emerging porphyrin-based ECL luminophore, was prepared by a simple hydrothermal method using tetrakis(4-carboxyphenyl) porphyrin, which has excellent ECL emission as well as good ECL efficiency. Because the ECL emission spectrum of PCN-222 is highly matched to the absorption spectrum of gold nanoparticle-modified graphene oxide (AuNPs/NSG) nanocomposites, they were used as donor-acceptor counterparts in this work for the ECL-RET strategy. Under optimal conditions, the ECL immunosensor showed a sensitive response to ZEN in a wide detection range, with a linearity of 0.0005-1000 ng mL-1 and a detection limit of 0.15 pg mL-1. In addition, the sensor showed good potential for application in the detection of wheat and corn samples, providing a new approach for the detection of mycotoxin-like contaminants such as ZEN in food grains.


Assuntos
Técnicas Biossensoriais , Nanopartículas Metálicas , Estruturas Metalorgânicas , Zearalenona , Imunoensaio/métodos , Ouro , Técnicas Biossensoriais/métodos , Medições Luminescentes/métodos , Transferência de Energia
4.
Int Heart J ; 60(4): 886-898, 2019 Jul 27.
Artigo em Inglês | MEDLINE | ID: mdl-31308321

RESUMO

Current studies demonstrating the effects of nicorandil in the prognosis of coronary artery disease (CAD) patients who received percutaneous coronary intervention (PCI) are inconclusive due to the small sample size and small events rate.PubMed, OVID, CBM and CNKI databases were searched using a pre-specified search string to collect randomized controlled trials (RCTs) studying the effects of nicorandil on CAD patients receiving PCI. Data on all-cause mortality and cardiovascular events were collected. RevMan 5.3 software was used for meta-analysis. Subgroup analysis was conducted in patients receiving primary PCI (PPCI) and elective PCI (EPCI).A total of 18 RCTs were included in our final analysis. Nicorandil treatment significantly reduced total mortality in PPCI (Peto OR = 0.44, 95%CI 0.25-0.79, P = 0.006) and EPCI (Peto OR = 0.41, 95%CI 0.25-0.67, P = 0.0004), cardiovascular death in both PPCI (Peto OR = 0.41, 95%CI 0.20-0.84, P = 0.01) and EPCI (Peto OR = 0.40, 95%CI 0.20-0.80, P = 0.009), and heart failure in PPCI (RR = 0.36, 95%CI 0.22-0.59, P < 0.0001). When compared with placebo plus standard treatment or standard treatment alone, nicorandil plus standard treatment was associated with reduced total mortality in both PPCI and EPCI, CV death in EPCI, and heart failure in PPCI. Nicorandil is associated with lower risks of total mortality and CV death in PPCI and EPCI in those who received nicorandil > 28 days.Nicorandil as an adjunct therapy along with PCI is associated with reduced total mortality and cardiovascular death in PPCI and EPCI patients, and reduced heart failure in PPCI patients.


Assuntos
Doença da Artéria Coronariana , Nicorandil/uso terapêutico , Intervenção Coronária Percutânea , Causas de Morte/tendências , Doença da Artéria Coronariana/tratamento farmacológico , Doença da Artéria Coronariana/mortalidade , Doença da Artéria Coronariana/cirurgia , Saúde Global , Humanos , Prognóstico , Taxa de Sobrevida/tendências , Vasodilatadores/uso terapêutico
5.
AJR Am J Roentgenol ; 211(2): 327-334, 2018 08.
Artigo em Inglês | MEDLINE | ID: mdl-29927331

RESUMO

OBJECTIVE: The objective of this study was to compare the prognoses of patients with low- and high-risk rectal cancer detected by MRI who were treated without neoadjuvant chemoradiotherapy (NCRT) and to determine independent risk factors. MATERIALS AND METHODS: This retrospective study included 185 patients with pathologically proven rectal adenocarcinoma who were treated without NCRT. Cancer was defined as high risk if one or more of the following factors were present: extramural depth of tumor invasion greater than 5 mm or stage T4a or T4b for tumor in the mid or high rectum; involvement of intersphincteric space, levators, or adjacent organs for tumor in the low rectum; extramural venous invasion (EMVI); or circumferential resection margin (CRM) involvement. Patients without any of those risk factors were placed in the low-risk group. The Kaplan-Meier method and Cox proportional hazards regression model were used to compare the survival outcomes between the two groups and to investigate the univariate and multivariate influences of the risk factors. RESULTS: Cancer was deemed to be low risk in 65 (35.1%) patients and high risk in 120 (64.9%) patients. The two patient groups had statistically significant differences in 3-year actuarial overall survival (OS; 100% vs 88.3%, p = 0.0044), disease-free survival (DFS; 92.3% vs 60.0%, p < 0.0001), and local recurrence (LR; 1.5% vs 10.0%, p = 0.0297). CRM involvement was identified as an independent risk factor for OS (hazard ratio [HR], 4.78; 95% CI, 1.24-18.45), DFS (HR, 2.44; 95% CI, 1.24-4.81), and LR (HR, 3.92; 95% CI, 1.07-14.41). Moreover, EMVI was identified as an independent risk factor for DFS (HR, 2.46; 95% CI, 1.28-4.74). CONCLUSION: The LR and long-term survival of patients in the low-risk group were more favorable than those of patients in the high-risk group. EMVI and CRM status were independent risk factors.


Assuntos
Imageamento por Ressonância Magnética/métodos , Neoplasias Retais/diagnóstico por imagem , Neoplasias Retais/cirurgia , Adulto , Idoso , Idoso de 80 Anos ou mais , Quimiorradioterapia , Meios de Contraste , Feminino , Gadolínio DTPA , Humanos , Masculino , Pessoa de Meia-Idade , Terapia Neoadjuvante , Invasividade Neoplásica , Estadiamento de Neoplasias , Prognóstico , Neoplasias Retais/patologia , Sistema de Registros , Estudos Retrospectivos , Fatores de Risco , Taxa de Sobrevida
6.
Mikrochim Acta ; 185(5): 275, 2018 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-29717360

RESUMO

A flower-like Au/Cu alloy nanocomposite (Au/Cu NFs) was synthesized and used in an electrochemiluminescence (ECL) based method for sensitive determination of the dye Sudan I. The Au-g-C3N4 nanosheets as an ECL emitter were prepared by electrostatic adsorption between gold nanoparticles and g-C3N4. They form a film on a glassy carbon electrode (GCE) and then can be connected with Sudan I antigen via gold-nitrogen bond and amidation reactions. The Au/Cu NFs combined with Sudan I antibody also via the Au-N bond and was introduced into the modified GCE by specific recognition between the antibody and the antigen. The overlap between emission spectra of the Au-g-C3N4 nanosheets and absorption spectra of Au/Cu NFs enabled the appearance of ECL resonance energy transfer process. That is, when the Sudan I analyte not present, the ECL was weakened due to absorption by the gray Au/Cu NFs on applying voltages from -1.7 V to 0 V. Conversely, the Au/Cu NFs on the GCE are reduced due to the competition for the antibody between the analyte and the antigen. A strong green ECL emission was obtained. The ECL response is linear in the 0.5 pg mL-1 to 100 ng mL-1 Sudan I concentration range, and the detection limit is 0.17 pg mL-1. Graphical abstract An Au/Cu alloy flower-like nanocomposite (Au/Cu NFs) is firstly synthesized as an acceptor to constitute an electrochemiluminescence-resonance energy transfer (ECL-RET) system for sensitive measurement of Sudan I, while Au nanoparticles (Au NPs) functionalized graphitic carbon nitride (g-C3N4) acted as a donor.


Assuntos
Ligas/química , Ouro/química , Grafite/química , Imunoensaio/métodos , Nanoestruturas/química , Naftóis/análise , Nitrilas/química , Eletroquímica , Análise de Alimentos , Limite de Detecção , Luminescência , Naftóis/química
7.
PLoS One ; 19(7): e0307528, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-39042630

RESUMO

Digital technologies can bring about fundamental changes in corporate processes, which may result in a shift from process innovation to digital process innovation. However, owing to resource constraints and various stakeholders, digital process implementation is extremely challenging for firms. Based on stakeholder theory, this study explores whether and how stakeholder pressure for digitalization can facilitate corporate digital process innovation and unravels the mediating effect of routine reconfiguration and the moderating effect of strategic flexibility. The findings from a survey of 351 firms prove that stakeholder pressure for digitalization can facilitate corporate digital process innovation via routine reconfiguration. Moreover, this study finds that increased strategic flexibility can strengthen the positive mediating effect of routine reconfiguration. The findings contribute to the deep understanding of digital process innovation and offer a boundary condition for the effectiveness of stakeholder pressure.


Assuntos
Participação dos Interessados , Humanos , Tecnologia Digital , Inquéritos e Questionários , Inovação Organizacional
8.
J Diabetes ; 16(2): e13479, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-37751894

RESUMO

BACKGROUND: The association between adrenal size and metabolic profiles in patients with diabetes mellitus (DM) is unclear. This study was conducted to determine whether the adrenal thickness measured by computed tomography (CT) is correlated with the metabolic profiles of patients with DM. METHODS: This was a cross-sectional study including 588 Chinese hospitalized patients with DM without comorbidities or medications known to affect adrenal morphology or hormone secretion. Adrenal limb thickness was measured on unenhanced chest CT. Participants were stratified into tertiles according to their total adrenal limb thickness. Linear and logistic regression models were used to estimate the correlations. RESULTS: After adjustment for sex and age, the adrenal thickness was positively associated with body mass index (BMI), waist circumference (WC), urinary albumin/creatinine ratio, and 24-h urinary free cortisol (UFC) and negatively correlated with high-density lipoprotein cholesterol. The sequential equation model (SEM) suggested UFC partially mediated the effect of adrenal limb thickness on WC by 12%. Adrenal thickness, but not UFC, was associated with a higher risk of existing hypertension (odds ratio [OR] = 3.78, 95% confidence interval [CI] 1.58, 9.02) and hyperlipidemia (OR = 2.76, 95% CI 1.03, 7.38), independent of age, gender, BMI, and WC. CONCLUSIONS: The adrenal thickness is independently associated with BMI, WC, cortisol levels, urinary albumin/creatinine ratio, hypertension, and dyslipidemia but not glycemic parameters in patients with diabetes. Our study encourages further studies to investigate the role of adrenal physiology in patients with diabetes.


Assuntos
Diabetes Mellitus , Hipertensão , Humanos , Fatores de Risco , Estudos Transversais , Hidrocortisona , Creatinina , Circunferência da Cintura/fisiologia , Albuminas , Índice de Massa Corporal
9.
J Med Chem ; 67(15): 13363-13382, 2024 Aug 08.
Artigo em Inglês | MEDLINE | ID: mdl-38987863

RESUMO

Human telomerase reverse transcriptase (hTERT) may have noncanonical functions in transcriptional regulation and metabolic reprogramming in cancer cells, but it is a challenging target. We thus developed small-molecule ligands targeting hTERT promoter G-quadruplex DNA structures (hTERT G4) to downregulate hTERT expression. Ligand 5 showed high affinity toward hTERT G4 (Kd = 1.1 µM) and potent activity against triple-negative breast cancer cells (MDA-MB-231, IC50 = 1 µM). In cell-based assays, 5 not only exerts markedly inhibitory activity on classical telomere functions including decreased telomerase activity, shortened telomere length, and cellular senescence but also induces DNA damage, acute cellular senescence, and apoptosis. This study reveals that hTERT G4-targeting ligand may cause mitochondrial dysfunction, disrupt iron metabolism and activate ferroptosis in cancer cells. The in vivo antitumor efficacy of 5 was also evaluated in an MDA-MB-231 xenograft mouse model and approximately 78.7% tumor weight reduction was achieved. No observable toxicity against the major organs was observed.


Assuntos
Antineoplásicos , Regulação para Baixo , Quadruplex G , Regiões Promotoras Genéticas , Telomerase , Neoplasias de Mama Triplo Negativas , Telomerase/antagonistas & inibidores , Telomerase/metabolismo , Humanos , Quadruplex G/efeitos dos fármacos , Neoplasias de Mama Triplo Negativas/tratamento farmacológico , Neoplasias de Mama Triplo Negativas/patologia , Animais , Ligantes , Feminino , Regulação para Baixo/efeitos dos fármacos , Camundongos , Antineoplásicos/farmacologia , Antineoplásicos/química , Antineoplásicos/uso terapêutico , Linhagem Celular Tumoral , Bibliotecas de Moléculas Pequenas/química , Bibliotecas de Moléculas Pequenas/farmacologia , Apoptose/efeitos dos fármacos , Ensaios Antitumorais Modelo de Xenoenxerto , Camundongos Nus , Senescência Celular/efeitos dos fármacos , Camundongos Endogâmicos BALB C
10.
ACS Sens ; 9(3): 1545-1554, 2024 03 22.
Artigo em Inglês | MEDLINE | ID: mdl-38450702

RESUMO

rRNAs are prevalent in living organisms. They are produced in nucleolus and mitochondria and play essential cellular functions. In addition to the primary biofunction in protein synthesis, rRNAs have been recognized as the emerging signaling molecule and drug target for studies on nucleolus morphology, mitochondrial autophagy, and tumor cell malignancy. Currently, only a few rRNA-selective probes have been developed, and most of them encounter the drawbacks of low water solubility, poor nuclear membrane permeability, short emission wavelength, low stability against photobleaching, and high cytotoxicity. These unfavorable properties of rRNA probes limit their potential applications. In the present study, we reported a new rRNA-selective and near-infrared fluorescent turn-on probe, 4MPS-TO, capable of tracking rRNA in live human cancer cells. The real-time monitoring performance in nucleolus morphology and mitochondrial autophagy is demonstrated in HeLa cells. The probe shows great application potential for being used as a rRNA-selective, sensitive, and photostable imaging tool in chemical biology study and drug screening.


Assuntos
Mitofagia , Neoplasias , Humanos , Células HeLa , Corantes Fluorescentes/química , Imagem Óptica/métodos , Autofagia
11.
Luminescence ; 28(4): 551-6, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23576268

RESUMO

Water-soluble CdSe quantum dots (QDs) have been prepared by using L-cysteine as the stabilizer in an aqueous phase under the optimized conditions. The characteristics and shapes of CdSe QDs have been proposed on the basis of UV-Vis and fluorescence spectra. A rapid analytical method for electrochemiluminescence (ECL) determination of nitrite has been developed on the basis of the quenching effect on anodic ECL emission of CdSe QDs under the optimum experimental conditions. In a neutral system and at a relatively low potential (+0.960 V), the ECL emission of CdSe QDs could be greatly enhanced by sulfite and could be gradually quenched by nitrite at an indium tin oxide (ITO) electrode. The proposed method may allow the measurement of nitrite ranging from 1 µM to 0.5 mM with a correlation coefficient of 0.9956 (n = 10) and a detection limit of 0.2 µM (3σ), and the relative standard deviation for 10 µM nitrite (n = 9) is 1.72 %. The proposed method could be adopted for the sensitive detection of ECL quenchers by using nitrite as a model molecule.


Assuntos
Compostos de Cádmio/química , Técnicas Eletroquímicas , Medições Luminescentes , Nitritos/análise , Pontos Quânticos , Compostos de Selênio/química , Eletrodos , Solubilidade , Água/química
12.
Cancer Imaging ; 23(1): 74, 2023 Aug 03.
Artigo em Inglês | MEDLINE | ID: mdl-37537659

RESUMO

BACKGROUND: Our study aimed to explore the potential of radiomics features derived from CT images in predicting the prognosis and response to adjuvant chemotherapy (ACT) in patients with Stage II colorectal cancer (CRC). METHODS: A total of 478 patients with confirmed stage II CRC, with 313 from Shanghai (Training set) and 165 from Beijing (Validation set) were enrolled. Optimized features were selected using GridSearchCV and Iterative Feature Elimination (IFE) algorithm. Subsequently, we developed an ensemble random forest classifier to predict the probability of disease relapse.We evaluated the performance of the model using the concordance index (C-index), precision-recall curves, and area under the precision-recall curves (AUCPR). RESULTS: A radiomic model (namely the RF5 model) consisting of four radiomics features and T stage were developed. The RF5 model performed better than simple radiomics features or T stage alone, with higher C-index and AUCPR, as well as better sensitivity and specificity (C-indexRF5: 0.836; AUCPR = 0.711; Sensitivity = 0.610; Specificity = 0.935). We identified an optimal cutoff value of 0.1215 to split patients into high- or low-score subgroups, with those in the low-score group having better disease-free survival (DFS) (Training Set: P = 1.4e-11; Validation Set: P = 0.015). Furthermore, patients in the high-score group who received ACT had better DFS compared to those who did not receive ACT (P = 0.04). However, no statistical difference was found in low-score patients (P = 0.17). CONCLUSION: The radiomic model can serve as a reliable tool for assessing prognosis and identifying the optimal candidates for ACT in Stage II CRC patients. TRIAL REGISTRATION: Retrospectively registered.


Assuntos
Neoplasias Colorretais , Humanos , Intervalo Livre de Doença , China , Neoplasias Colorretais/diagnóstico por imagem , Neoplasias Colorretais/tratamento farmacológico , Aprendizado de Máquina , Quimioterapia Adjuvante , Estudos Retrospectivos
13.
Clin Exp Metastasis ; 39(5): 771-781, 2022 10.
Artigo em Inglês | MEDLINE | ID: mdl-35918622

RESUMO

The ability to noninvasively detect and monitor the growth of orthotopic liver transplantation tumors is critical for replicating advanced colorectal cancer liver metastases (CRLMs) in animal models. We assessed the use of high-resolution ultrasound (HRU) to monitor CRLMs transplanted using various cell concentrations. Sixty BALB/c female mice were randomly divided into 3 groups, and murine colonic CT26 cells were injected into the left liver lobe at concentrations of 1 × 102 (group 1), 1 × 103 (group 2), or 1 × 104 (group 3). Tumor presentation, location, number, size, shape, and echogenicity were assessed daily with 24-MHz center frequency HRU starting 6 days after injection. Animals were sacrificed when the largest tumor was ≥ 1 cm in diameter. Sensitivity, specificity, and area under curve (AUC) of CRLMs diagnosed with HRU were calculated using receiver operating characteristic curve analysis. In group 1, 94% of mice formed < 5 tumors, and 41% formed a single tumor. Tumors were first detected with HRU on day 12 in group 1, day 10 in group 2, and day 7 in group 3; tumor volume doubling times were 14-15 days, 11-12 days, and 7-8 days, respectively. With a long diameter threshold of 2.4 mm, diagnostic sensitivity and specificity of HRU were 94.1% and 88.7%, respectively, and the AUC was 0.962. These findings suggest that HRU can be used to accurately detect and monitor the growth of CRLMs in an orthotopic transplantation mouse model, especially when a lower concentration of cells is used.


Assuntos
Neoplasias do Colo , Neoplasias Colorretais , Neoplasias Hepáticas , Animais , Neoplasias do Colo/patologia , Neoplasias Colorretais/diagnóstico por imagem , Neoplasias Colorretais/patologia , Modelos Animais de Doenças , Feminino , Neoplasias Hepáticas/diagnóstico por imagem , Neoplasias Hepáticas/secundário , Camundongos , Camundongos Endogâmicos BALB C , Transplante de Neoplasias , Ultrassonografia
14.
Luminescence ; 26(6): 741-6, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-21548000

RESUMO

A sensitive and simple chemiluminescent (CL) method for the determination of clomipramine has been developed by combining the flow-injection analysis (FIA) technique, which is based on the CL intensity generated from the redox reaction of potassium permanganate (KMnO(4))-formic acid in sulphuric acid (H(2)SO(4)) medium. Under the optimum conditions, the linear range for the determination of clomipramine was 0.04-4 µg/mL, with a correlation coefficient of 0.9988 (n = 10) and a detection limit of 0.008 µg/mL (3σ), and the relative standard deviation (RSD) for 2.0 µg/mL clomipramine (n = 11) is 1.26%. The proposed method has been successfully applied to the determination of the studied clomipramine in pharmaceutical preparations. The possible reaction mechanism is discussed.


Assuntos
Antidepressivos Tricíclicos/química , Clomipramina/análise , Análise de Injeção de Fluxo/métodos , Formiatos/química , Permanganato de Potássio/química , Concentração de Íons de Hidrogênio , Luminescência
15.
Artigo em Zh | MEDLINE | ID: mdl-22468315

RESUMO

OBJECTIVE: To explore the influence factors on determining Tin concentration in air of workplaces with flame atomic absorption spectrometry and to establish an accurate, sensitive and high-efficient method. METHODS: The different reagents were used to digest the sampling filter membranes and the determining conditions of flame atomic absorption spectrometry were adjusted, then the determining results were compared. RESULTS: When 3 ml hydrochloric acid and 0.5 ml nitric acid served as the digesting reagents and the determining conditions of flame atomic absorption spectrometry were adjusted to the best conditions, there was the good linearity in the tested concentration range of Tin, the correlation coefficient was larger than 0.9990. The limit of quantification was 1.0 p.g/ml. The extraction recovery was between 99.6%-102.6%, and the RSD were all less than 5.0%. CONCLUSION: The proper kinds and quantity of digestive reagents in pretreatment of the samples should be chosen for the accuracy and precision of the determination according to the influence factors of determination.


Assuntos
Poluentes Ocupacionais do Ar/análise , Espectrofotometria Atômica/métodos , Estanho/análise , Local de Trabalho
16.
Front Psychol ; 12: 731162, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34621225

RESUMO

Job insecurity is considered an important antecedent of an employee's creativity. Though, the relationship between job insecurity and proactive behavior has been neglected in previous human resources management studies. The aim of this study is to explore the influence of job insecurity on employees' proactive behavior and its mechanism. Based on the social cognitive theory and cognitive appraisal theory, two types of cognitive appraisal of employee's job insecurity (hindrance vs. challenge) as mediator variables of job insecurity and proactive behavior association. In addition, the moderator roles of self-efficacy are examined. This study is carried out with 257 employees from Chinese firms to examine the hypothesized moderated mediation model by using the hierarchical regression analysis and the bootstrap. The results showed a different effect of job insecurity depending on its conceptualization. The results show that job insecurity has a negative effect on employees' proactive behavior. At the same time, cognitive appraisal of employees' job insecurity mediated the association between job insecurity and employee's proactive behavior. Self-efficacy not only moderates the relationship between job insecurity and cognitive appraisal but also moderate the cognitive appraisal's mediation effect between job insecurity and proactive behavior. The study's theoretical and practical contributions and future research are discussed.

17.
Dig Dis Sci ; 55(7): 1824-30, 2010 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-19763824

RESUMO

PURPOSE: The Glutathione S-transferases (GSTs) play multiple roles in the pathogenesis and treatment of cancer. Studies investigating the association between Glutathione S-transferase M1 (GSTM1) null genotype and gastric cancer risk report conflicting results. The purpose of this study was to quantitatively summarize the evidence for such a relationship. RESULTS: This meta-analysis included 35 studies, which included 4,505 gastric cancer cases and 9,062 controls. The combined results based on all studies showed that the GSTM1 null genotype was associated with an increased risk of gastric cancer (OR = 1.15, 95% confidence interval [CI] = 1.02, 1.29). When stratifying for race, results were similar among Asians (OR = 1.24, 95% CI = 1.07, 1.44) except Caucasians (OR = 1.04, 95% CI = 0.88, 1.24). When stratifying by the location, stage, Lauren's classification, histological differentiation, lymph node metastasis, smoking, and Helicobacter pylori infection of gastric cancer, we observed that patients with diffuse classification had a significantly higher frequency null genotype (OR = 4.80, 95% CI = 1.65,13.94) than those with intestinal classification among Caucasians. CONCLUSIONS: This meta-analysis suggests that the GSTM1 null genotype may be associated with gastric cancer among Asians.


Assuntos
Povo Asiático/genética , Predisposição Genética para Doença/epidemiologia , Glutationa Transferase/genética , Neoplasias Gástricas/epidemiologia , Neoplasias Gástricas/genética , Estudos de Casos e Controles , China/epidemiologia , Feminino , Regulação Neoplásica da Expressão Gênica , Genótipo , Humanos , Incidência , Masculino , Polimorfismo de Fragmento de Restrição , Prognóstico , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Neoplasias Gástricas/etnologia , Neoplasias Gástricas/patologia , Taxa de Sobrevida
18.
Dig Dis Sci ; 55(6): 1525-32, 2010 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-19669876

RESUMO

PURPOSE: Studies investigating the association between interleukin10 (IL10) -592 promoter polymorphism and gastric cancer risk report conflicting results. The objective of this study was to quantitatively summarize the evidence for such a relationship. METHODS: Two investigators independently searched the MEDLINE and Embase databases. This meta-analysis included ten case-control studies, which included 1,715 gastric cancer cases and 2,783 controls. RESULTS: The combined results based on all studies showed that there was no significant difference in genotype distribution (AA odds ratio [OR] = 0.88, 95% confidence interval [CI] = 0.66, 1.18; AC OR = 1.09, 95% CI = 0.95, 1.24; CC OR = 1.03, 95% CI = 0.89, 1.18) between gastric cancer and noncancer patients. When stratifying for race, the results were similar, except that patients with gastric cancer had a significantly lower frequency of AA (OR = 0.67, 95% CI = 0.52, 0.87) and a higher frequency of AC (OR = 1.34, 95% CI = 1.07, 1.68) than noncancer patients among Asians. When stratifying by the location of gastric cancer, we found that patients with cardia gastric cancer had a significantly lower frequency of AA (OR = 0.41, 95% CI = 0.20, 0.84) than those with noncardia gastric cancer among Caucasians. When stratifying by Lauren's classification of gastric cancer, we found that patients with diffuse gastric cancer had a significantly higher frequency of AA (OR = 1.91, 95% CI = 1.07, 3.41) than those with intestinal gastric cancer among Caucasians. CONCLUSIONS: This meta-analysis suggests that the IL10 -592 promoter polymorphism may be associated with gastric cancer among Asians, and that differences in genotype distribution may be associated with the location and Lauren's classification of gastric cancer.


Assuntos
Povo Asiático/genética , Interleucina-10/genética , Polimorfismo Genético , Regiões Promotoras Genéticas , Neoplasias Gástricas/genética , Medicina Baseada em Evidências , Predisposição Genética para Doença , Humanos , Razão de Chances , Fenótipo , Medição de Risco , Fatores de Risco , Neoplasias Gástricas/etnologia , Neoplasias Gástricas/imunologia
19.
Eur J Radiol ; 131: 109205, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32871292

RESUMO

PURPOSE: To develop a radiomic nomogram to predict disease-free survival (DFS) in patients with colon cancer. METHODS: We retrospectively identified 302 patients with stage III colon cancer and 269 patients with stage II colon cancer who had undergone multidetector computed tomography (MDCT) and radical resection between January 2009 and December 2015. Patients were divided into a training cohort (n = 322) and an external validation cohort (n = 249). Radiomic features were extracted from MDCT images, and a radiomic signature was built as to predict DFS. A radiomic nomogram integrating the radiomic signature and clinicopathologic characteristics was developed using multivariable logistic regression. The nomogram was evaluated with regard to calibration, discrimination, and clinical utility. RESULTS: The radiomic signature was an independent prognostic factor for DFS in the training cohort (HR = 1.102; 95 % CI: 1.052-1.156; P < 0.001) and the external validation cohort (HR = 1.157; 95 % CI: 1.030-1.301; P = 0.014). The radiomic signature-based nomogram was more effective at predicting DFS than either the TNM staging system or a clinicopathologic nomogram. The C-indices of the radiomic nomogram and TNM staging system were 0.780 (95 % CI: 0.734-0.847) and 0.738 (0.687-0.784) respectively. The radiomic signature-based nomogram demonstrated good fitness (shown by calibration curves) and clinical usefulness (shown by decision curve analysis). CONCLUSION: A radiomic signature derived from MDCT images can effectively predict DFS in patients with stage II and III colon cancer and could be used as a supplement for risk stratification.


Assuntos
Neoplasias do Colo/diagnóstico por imagem , Intervalo Livre de Doença , Nomogramas , Tomografia Computadorizada por Raios X , Adulto , Neoplasias do Colo/patologia , Feminino , Humanos , Estimativa de Kaplan-Meier , Masculino , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Prognóstico , Modelos de Riscos Proporcionais , Estudos Retrospectivos , Tomografia Computadorizada por Raios X/métodos
20.
Dig Dis Sci ; 54(7): 1379-85, 2009 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-18989779

RESUMO

Studies investigating the association of polymorphisms in the 5'-untranslated regions (5'UTR) and 3'-untranslated regions (3'UTR) of thymidylate synthase with gastric cancer susceptibility and sensitivity to fluoropyrimidine-based chemotherapy report conflicting results. The objective of this study was to quantitatively summarize the evidence for such a relationship. This meta-analysis included ten studies, which included 1,730 gastric cancer cases and 1,843 controls. The combined results based on all studies showed that there was no significant difference in genotype distribution of 5'UTR or 3'UTR between gastric cancer and noncancer patients. When stratifying for race, we found that: (1) among Asians, patients with gastric cancer had significantly higher frequency of 2R/2R of 5'UTR than did noncancer patients, and (2) among Caucasians, patients with gastric cancer had significantly lower frequency of ins6/ins6 and higher frequency of ins6/del6 of 3'UTR than did noncancer patients. No significantly different response rate or survival of gastric cancer with fluoropyrimidine-based chemotherapy were observed with genotype distribution of 5'UTR or 3'UTR among Caucasians or Asians. This meta-analysis suggests that polymorphisms in the 5'UTR and 3'UTR of thymidylate synthase may be associated with gastric cancer susceptibility, but are not correlated with sensitivity of gastric cancer to fluoropyrimidine-based chemotherapy.


Assuntos
Regiões 3' não Traduzidas/genética , Regiões 5' não Traduzidas/genética , Predisposição Genética para Doença/genética , Neoplasias Gástricas/genética , Timidilato Sintase/genética , Povo Asiático/genética , Infecções por Helicobacter/epidemiologia , Helicobacter pylori , Humanos , Fatores de Risco , Neoplasias Gástricas/tratamento farmacológico , Neoplasias Gástricas/microbiologia , Neoplasias Gástricas/mortalidade , População Branca/genética
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