83 research outputs found

    Functionalization of bacterial cellulose nonwoven by poly(fluorophenol) to improve its hydrophobicity and durability

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    The present study aims to improve the hydrophobicity and durability of bacterial cellulose (BC) nonwoven by functionalization with poly(fluorophenol). To this end, laccase was first entrapped onto BC and then used to polymerize the fluorophenol {4-[4-(trifluoromethyl) phenoxy] phenol} in-situ. The polymerization of fluorophenol by laccase was confirmed through 1H NMR and MALDI-TOF analyses. The effect of poly(fluorophenol) on BC nonwoven was determined by evaluation of the surface hydrophobicity and olephobicity properties such as water contact angle (WCA), oil contact angle (OCA), surface energy and water/oil absorption time. After BC functionalization with poly(fluorophenol) (20 mM), the WCA increased from 54.5 ± 1.2° to 120 ± 1.5° while the surface energy decreased (11.58 ± 1.4 mN/m). The OCA was also increased from 46.5 ± 2.5° to 87 ± 2° along to the decrease of surface energy (8.7 ± 1.5°). X-ray photoelectron spectroscopy (XPS) analysis confirmed an increase in the fluorine content in BC from 5.27 to 17.57%. The findings confirmed the polymerization of fluorophenol by laccase and its entrapment onto a BC nanofiber structure. The durability of the functionalization with poly(fluorophenol) was confirmed by evaluating the washing fastness, tensile strength after washing and dimensional stability. The results indicate that the functionalized BC nonwoven had higher tensile strength (×10 times) and better dimensional stability (30%) than the non-functionalized BC nonwoven material.This work was supported by the Portuguese Foundationfor Science and Technology (FCT) under the scope of thestrategic funding of UID/BIO/04469/2019 unit and Bio-TecNorteoperation (NORTE-01-0145-FEDER-000004). This work wasalso supported by the National Research Foundation of Korea(NRF) grant funded by the Korea government (MSIT) (No. NRF-2019R1A2C1009217).info:eu-repo/semantics/publishedVersio

    Measurement of beta-amyloid peptides in specific cells using a photo thin-film transistor

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    The existence of beta-amyloid [Aβ] peptides in the brain has been regarded as the most archetypal biomarker of Alzheimer's disease [AD]. Recently, an early clinical diagnosis has been considered a great importance in identifying people who are at high risk of AD. However, no microscale electronic sensing devices for the detection of Aβ peptides have been developed yet. In this study, we propose an effective method to evaluate a small quantity of Aβ peptides labeled with fluorescein isothiocyanate [FITC] using a photosensitive field-effect transistor [p-FET] with an on-chip single-layer optical filter. To accurately evaluate the quantity of Aβ peptides within the cells cultured on the p-FET device, we measured the photocurrents which resulted from the FITC-conjugated Aβ peptides expressed from the cells and measured the number of photons of the fluorochrome in the cells using a photomultiplier tube. Thus, we evaluated the correlation between the generated photocurrents and the number of emitted photons. We also evaluated the correlation between the number of emitted photons and the amount of FITC by measuring the FITC volume using AFM. Finally, we estimated the quantity of Aβ peptides of the cells placed on the p-FET sensing area on the basis of the binding ratio between FITC molecules and Aβ peptides

    An endoscope with integrated transparent bioelectronics and theranostic nanoparticles for colon cancer treatment

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    The gastrointestinal tract is a challenging anatomical target for diagnostic and therapeutic procedures for bleeding, polyps and cancerous growths. Advanced endoscopes that combine imaging and therapies within the gastrointestinal tract provide an advantage over stand-alone diagnostic or therapeutic devices. However, current multimodal endoscopes lack the spatial resolution necessary to detect and treat small cancers and other abnormalities. Here we present a multifunctional endoscope-based interventional system that integrates transparent bioelectronics with theranostic nanoparticles, which are photoactivated within highly localized space near tumours or benign growths. These advanced electronics and nanoparticles collectively enable optical fluorescence-based mapping, electrical impedance and pH sensing, contact/temperature monitoring, radio frequency ablation and localized photo/chemotherapy, as the basis of a closed-loop solution for colon cancer treatment. In vitro, ex vivo and in vivo experiments highlight the utility of this technology for accurate detection, delineation and rapid targeted therapy of colon cancer or precancerous lesions.

    A More Appropriate Cardiac Troponin T Level That Can Predict Outcomes in End-Stage Renal Disease Patients with Acute Coronary Syndrome

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    Purpose: Cardiac troponin T (cTnT), a useful marker for diagnosing acute myocardial infarction (AMI) in the general population, is significantly higher than the usual cut-off value in many end-stage renal disease (ESRD) patients without clinically apparent evidence of AMI. The aim of this study was to evaluate the clinical usefulness of cTnT in ESRD patients with acute coronary syndrome (ACS). Materials and methods: Two hundred eighty-four ESRD patients with ACS were enrolled between March 2002 and February 2008. These patients were followed until death or June 2009. Medical records were reviewed retrospectively. The cut-off value of cTnT for AMI was evaluated using a receiver operating characteristic (ROC) curve. We calculated Kaplan-Meier survival curves, and potential outcome predictors were determined by Cox proportional hazard analysis. Results: AMIs were diagnosed in 40 patients (14.1%). The area under the curve was 0.98 in the ROC curve (p<0.001; 95% CI, 0.95-1.00). The summation of sensitivity and specificity was highest at the initial cTnT value of 0.35 ng/mL (sensitivity, 0.95; specificity, 0.97). Survival analysis showed a statistically significant difference in all-cause and cardiovascular mortalities for the group with an initial cTnT ≥0.35 ng/mL compared to the other groups. Initial serum cTnT concentration was an independent predictor for mortality. Conclusion: Because ESRD patients with an initial cTnT concentration ≥0.35 ng/mL have a poor prognosis, it is suggested that urgent diagnosis and treatment be indicated in dialysis patients with ACS when the initial cTnT levels are ≥0.35 ng/mL.ope

    Methylenetetrahydrofolate reductase C677T polymorphism in patients with lung cancer in a Korean population

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    <p>Abstract</p> <p>Background</p> <p>This study was designed to investigate an association between methylenetetrahydrofolate reductase (MTHFR) C677T polymorphism and the risk of lung cancer in a Korean population.</p> <p>Methods</p> <p>We conducted a large-scale, case-control study involving 3938 patients with newly diagnosed lung cancer and 1700 healthy controls. Genotyping was performed with peripheral blood DNA for MTHFR C677T polymorphisms. Statistical significance was estimated by logistic regression analysis.</p> <p>Results</p> <p>The MTHFR C677T frequencies of CC, CT, and TT genotypes were 34.5%, 48.5%, and 17% among lung cancer patients, and 31.8%, 50.7%, and 17.5% in the controls, respectively. The MTHFR 677CT and TT genotype showed a weak protection against lung cancer compared with the homozygous CC genotype, although the results did not reach statistical significance. The age- and gender-adjusted odds ratio (OR) of overall lung cancer was 0.90 (95% confidence interval (CI), 0.77-1.04) for MTHFR 677 CT and 0.88 (95% CI, 0.71-1.07) for MTHFR 677TT. However, after stratification analysis by histological type, the MTHFR 677CT genotype showed a significantly decreased risk for squamous cell carcinoma (age- and gender-adjusted OR, 0.78; 95% CI, 0.64-0.96). The combination of 677 TT homozygous with 677 CT heterozygous also appeared to have a protection effect on the risk of squamous cell carcinoma. We observed no significant interaction between the MTHFR C677T polymorphism and age and gender or smoking habit.</p> <p>Conclusions</p> <p>This is the first reported study focusing on the association between MTHFR C677T polymorphisms and the risk of lung cancer in a Korean population. The T allele was found to provide a weak protective association with lung squamous cell carcinoma.</p

    Methylenetetrahydrofolate reductase C677T polymorphism in patients with gastric and colorectal cancer in a Korean population

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    <p>Abstract</p> <p>Background</p> <p>This study was designed to investigate an association between the methylenetetrahydrofolate reductase (MTHFR) C677T polymorphism and the risk of gastric and colorectal cancer in the Korean population.</p> <p>Methods</p> <p>We conducted a population-based large-scale case-control study involving 2,213 patients with newly diagnosed gastric cancer, 1,829 patients with newly diagnosed colorectal cancer, and 1,700 healthy controls. Genotyping was performed with peripheral blood DNA for MTHFR C677T polymorphisms. The statistical significance was estimated by logistic regression analysis.</p> <p>Results</p> <p>The MTHFR C677T frequencies of CC, CT, and TT genotypes were 35.2%, 47.5%, and 17.3% among stomach cancer, 34%, 50.5%, and 15.5% in colorectal cancer, and 31.8%, 50.7%, and 17.5% in the controls, respectively. The MTHFR 677TT genotype showed a weak opposite association with colorectal cancer compared to the homozygous CC genotype [adjusted age and sex odds ratio (OR) = 0.792, 95% confidence interval (CI) = 0.638-0.984, <it>P </it>= 0.035]. Subjects with the MTHFR 677CT showed a significantly reduced risk of gastric cancer compared whose with the 677CC genotype (age- and sex-adjusted OR = 0.810; 95% CI = 0.696-0.942, <it>P </it>= 0.006). We also observed no significant interactions between the MTHFR C677T polymorphism and smoking or drinking in the risk of gastric and colorectal cancer.</p> <p>Conclusions</p> <p>The T allele was found to provide a weak protective association with gastric cancer and colorectal cancer.</p
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