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1.
Hemodial Int ; 27(3): 301-307, 2023 07.
Article in English | MEDLINE | ID: mdl-37010133

ABSTRACT

INTRODUCTION: BTB and CNC homology 1 (Bach1) is a protein that antagonizes some actions of nuclear factor erythroid 2-related factor-2 (Nrf2), the master regulator of cytoprotective responses. Bach1 binds to genomic DNA and inhibits the synthesis of antioxidant enzymes, thereby increasing inflammation. Bach1 may be a therapeutic target for mitigating inflammation in chronic kidney disease (CKD) patients. However, no clinical study has been reported on Bach1 in this population. This study aimed to evaluate Bach1 mRNA expression with different treatments for CKD, including conservative treatment (nondialysis), hemodialysis (HD), and peritoneal dialysis (PD). METHODS: Twenty patients undergoing HD (56.5 [19] years), 15 on PD (54 [24] years) and 13 nondialysis patients (63 [10] years, with an estimated glomerular filtration rate of 41 [14] mL/min/1.73 m2 ) were enrolled in the study. The mRNA expression of Nrf2, NF-kB, heme oxygenase 1 (HO-1), and Bach1 was evaluated in peripheral blood mononuclear cells using quantitative real-time polymerase chain reaction. Malondialdehyde (MDA) was evaluated as a lipid peroxidation marker. Routine biochemical parameters were also evaluated. FINDINGS: As expected, patients on dialysis were more inflamed. Bach1 mRNA expression was significantly higher in patients undergoing HD than in PD and nondialysis patients (p < 0.007). The mRNA expression of HO-1, NF-kB, and Nrf2 was not different in the groups. CONCLUSION: In conclusion, CKD patients on HD exhibited an upregulation of Bach1 mRNA expression compared to patients on PD treatment and nondialysis CKD patients. The association between Nrf2 and Bach1 expression in these patients warrants further investigation.


Subject(s)
NF-E2-Related Factor 2 , Renal Insufficiency, Chronic , Humans , NF-E2-Related Factor 2/genetics , NF-E2-Related Factor 2/metabolism , Basic-Leucine Zipper Transcription Factors/genetics , Basic-Leucine Zipper Transcription Factors/metabolism , NF-kappa B/metabolism , Leukocytes, Mononuclear/metabolism , Renal Dialysis , Heme Oxygenase-1/genetics , Heme Oxygenase-1/metabolism , Renal Insufficiency, Chronic/genetics , Renal Insufficiency, Chronic/therapy , Inflammation , RNA, Messenger/genetics , RNA, Messenger/metabolism
2.
Materials (Basel) ; 14(19)2021 Sep 27.
Article in English | MEDLINE | ID: mdl-34640023

ABSTRACT

The current scientific literature lacks an adequate description of hardware used to machine timber. Traditional woodworking and metals fabrication consists of tungsten carbide (TC) inserts. In this work, the authors investigate the influence of cutting tool geometry on the resulting surface roughness of timber samples. A variety of wood types were used in these studies to provide broad information on the correlation between the cutting tools used and resulting surface morphology. The cutting tools were prepared on a computer numerical control (CNC) lathe and roughness average (Ra) and average maximum peak to valley height of the profile (Rz) parameters were measured by contact stylus. The tip radius of the TC inserts used was determined to be the most significant factor that impacted Ra and Rz. In summary, we found that the tip radius of the TC insert was inversely proportional to the roughness level, indicating that a flatter TC insert cutting end results in a smoother wood surface.

3.
Nanomaterials (Basel) ; 10(9)2020 Sep 08.
Article in English | MEDLINE | ID: mdl-32911746

ABSTRACT

Kraft pulp cellulose was hydrolyzed using sulfuric acid, under different thermophysical conditions of temperature, time, pulp concentration, and sonication time. The experimental design revealed the effect of these conditions and their interaction on the hydrolysis yield obtained. In addition, the top five cellulose nanocrystals (CNCs) yields from this experiment design were analyzed. The results obtained indicated that CNCs possess a morphology that can be described as individualized rod particles, with average diameters less than 50 nm and different size distribution. In the analysis of CNCs features, significant Pearson correlations were established between the crystallinity of the CNC, CNC yield, and interplanar crystallites distance (Δd/d). The thermogravimetric (DTG) profiles exhibited two CNCs degradation stages, where the second stage CNCs degradation showed a significative correlation with CNC sulfur content. In our analysis, the crystallographic parameters exhibited a correlation with the mechanical behavior of the CNC, since the potential variation between the distances of the crystalline planes is related to the stress and deformation present in the crystallites of CNCs. This study provides new knowledge regarding CNCs, further enhancing information for CNC-based industries and the processability of CNCs for the development of new materials.

4.
Int J Mol Sci ; 22(1)2020 Dec 31.
Article in English | MEDLINE | ID: mdl-33396298

ABSTRACT

In this study, we intended to evaluate the performance of olefin-based drilling fluids after addition of cellulose nanocrystal (CNC) derivatives. For this purpose, firstly, cellulose nanocrystals, produced from sulfuric acid hydrolysis of cotton fibers, were functionalized with poly(N-isopropylacrylamide) (PNIPAM) chains via free radicals. The samples were then characterized via Fourier transform infrared spectroscopy (FTIR), nuclear magnetic resonance (NMR), X-ray diffraction (XRD), thermogravimetric analysis (TGA), confocal microscopy, dynamic light scattering (DLS), and zeta potential measurements in water. The FTIR and NMR spectra exhibited the characteristic signals of CNC and PNIPAM groups, indicating successful grafting. As expected, X-ray diffractograms showed that the crystallinity of CNCs reduces after chemical modification. TGA revealed that the surface-functionalized CNCs present higher thermal stability than pure CNCs. The confocal microscopy, zeta potential, and DLS results were consistent with the behavior of cellulose nanocrystals decorated by a shell of PNIPAM chains. The fluids with a small amount of modified CNCs presented a much lower volume of filtrate after high-temperature and high-pressure (HTHP) filtration tests than the corresponding standard fluid, indicating the applicability of the environmentally friendly particles for olefin-based drilling fluids.


Subject(s)
Acrylic Resins/chemistry , Alkenes/chemistry , Cellulose/chemistry , Nanoparticles/chemistry , Polymers/chemistry , Water/chemistry , Hydrolysis , Temperature
5.
J Mech Behav Biomed Mater ; 60: 547-556, 2016 07.
Article in English | MEDLINE | ID: mdl-27058002

ABSTRACT

OBJECTIVES: The purpose of this study was to evaluate the shear bond strength of veneering feldspathic porcelain to zirconia substrates modified by CNC-milling process or by coating zirconia with a composite interlayer. METHODS: Four types of zirconia-porcelain interface configurations were tested: RZ - porcelain bonded to rough zirconia substrate (n=16); PZ - porcelain bonded to zirconia substrate with surface holes (n=16); RZI - application of a composite interlayer between the veneering porcelain and the rough zirconia substrate (n=16); PZI - application of a composite interlayer between the porcelain and the zirconia substrate treated by CNC-milling (n=16). The composite interlayer was composed of zirconia particles reinforced porcelain (30%, vol%). The mechanical properties of the ceramic composite have been determined. The shear bond strength test was performed at 0.5mm/min using a universal testing machine. The interfaces of fractured and untested specimens were examined by FEG-SEM/EDS. Data was analyzed with Shapiro-Wilk test to test the assumption of normality. The one-way ANOVA followed by Tukey HSD multiple comparison test was used to compare shear bond strength results (α=0.05). RESULTS: The shear bond strength of PZ (100±15MPa) and RZI (96±11MPa) specimens were higher than that recorded for RZ (control group) specimens (89±15MPa), although not significantly (p>0.05). The highest shear bond strength values were recorded for PZI specimens (138±19MPa), yielding a significant improvement of 55% relative to RZ specimens (p<0.05). SIGNIFICANCE: This study shows that it is possible to highly enhance the zirconia-porcelain bond strength - even by ~55% - by combining surface holes in zirconia frameworks and the application of a proper ceramic composite interlayer.


Subject(s)
Dental Porcelain , Dental Veneers , Zirconium , Dental Bonding , Dental Stress Analysis , Humans , Materials Testing , Shear Strength , Surface Properties
6.
J Pediatr ; 163(6): 1670-6, 2013 Dec.
Article in English | MEDLINE | ID: mdl-23992677

ABSTRACT

OBJECTIVE: Using video monitoring technologies, we investigated teenage driving risk variation during the first 18 months of independent driving. STUDY DESIGN: Driving data were collected on 42 teenagers whose vehicles were instrumented with sophisticated video and data recording devices. Surveys on demographic and personality characteristics were administered at baseline. Drivers were classified into 3 risk groups using a K-mean clustering method based on crash and near-crash (CNC) rate. The change in CNC rates over time was evaluated by mixed-effect Poisson models. RESULTS: Compared with the first 3 months after licensure (first quarter), the CNC rate for participants during the third, fourth, and fifth quarters decreased significantly to 59%, 62%, and 48%, respectively. Three distinct risk groups were identified with CNC rates of 21.8 (high-risk), 8.3 (moderate-risk), and 2.1 (low-risk) per 10 000 km traveled. High- and low-risk drivers showed no significant change in CNC rates throughout the 18-month study period. CNC rates for moderate-risk drivers decreased substantially from 8.8 per 10 000 km in the first quarter to 0.8 and 3.2 in the fourth and fifth quarters, respectively. The 3 groups were not distinguishable with respect to personality characteristics. CONCLUSION: Teenage CNC rates varied substantially, with distinct high-, moderate-, and low-risk groups. Risk declined over time only in the moderate-risk group. The high-risk drivers appeared to be insensitive to experience, with CNC rates consistently high throughout the 18-month study period, and the moderate-risk group appeared to learn from experience.


Subject(s)
Accidents, Traffic/statistics & numerical data , Automobile Driving , Adolescent , Female , Humans , Male , Risk Assessment , Time Factors
7.
Rev. chil. neuro-psiquiatr ; Rev. chil. neuro-psiquiatr;51(1): 32-37, mar. 2013. ilus
Article in Spanish | LILACS | ID: lil-677297

ABSTRACT

Cerebral Intravascular Lymphomatosis is a type of non Hodgkin Lymphoma, generally composed with B cells, its ocurrence is infrequent, clinically progressive and has a fatal course. Vascular damage is related with tumoral infiltration and small caliber occlusion, with results in multi infarcts. Neurological symptoms and signs are frequently the first clinical manifestation, which include sub acute encephalopathy, cognitive impairment, delirium, aphasia, hemipharesis, visual disturbances, paraplegia, paresthesia and cranial nerves involvement. MRI shows images of vasculitis from CNS. Cerebral Intravascular Lymphomatosis must be considered in differential diagnosis of rapid and subacute dementias, and clinical cases with small vessel recurrent multi infarct of unusual etiology. We present the clinical case of a patient with rapid progressive dementia and systemic disease manifestation. The CNS involvement was characterized as a subacute encephalopathy, with confusion and agitation, seizures, motor disturbances, bilateral plantar extensor reflexes and cerebellar signs. The clinical symptomatic course was progressive, with weight loss and fluctuant fever. The patient had a fatal course after he was treated with Methylprednisolone. Postmortem pathologic examination revealed a diffuse non Hodgkin lymphoma of B cells, intravascular variant, with brain compromise, cerebellum, suprarenal glands, pancreas, myocardium, thyroid gland, lung kidney and the lever...


La linfomatosis intravascular cerebral es un tipo de Linfoma no Hodgkin generalmente de células B, de presentación infrecuente, curso clínico progresivo y fatal. El daño vascular es producto de oclusión de vasos de pequeño calibre por infiltración tumoral, con resultado de múltiples infartos. Las manifestaciones neurológicas suelen ser la forma de presentación clínica inicial, caracterizadas por un amplio espectro que incluye encefalopatía subaguda, deterioro cognitivo, delirio, afasia, hemiparesia, trastornos visuales, paraplejia, parestesias y compromiso de pares craneanos. Los estudios de RNM evidencian alteraciones indistinguibles de las vasculitis del SNC. La linfomatosis intravascular debe considerarse en el diagnóstico diferencial de las demencias rápidamente progresivas y en los cuadros de multi infarto cerebral de pequeño vaso de etiología inusual y recurrente. Se presenta el caso de un paciente con demencia rápidamente progresiva, con manifestaciones neurológicas de deterioro cognitivo y enfermedad sistémica. El compromiso del SNC se expresó como encefalopatía subaguda con confusión, agitación, y crisis convulsivas, trastornos motores con reflejo cutáneo plantar extensor bilateral y compromiso cerebeloso, de curso clínico sintomático progresivo, con baja de peso y fiebre fluctuante. El paciente fue sometido a tratamiento con metilprednisolona a pesar del cual falleció. El estudio necrópsico demostró alteraciones por Linfoma no Hodgkin difuso de células B, variante intra vascular, con compromiso del cerebro, cerebelo, glándulas suprarrenales, páncreas, miocardio, tiroides, pulmón riñón e hígado...


Subject(s)
Humans , Male , Middle Aged , Dementia/etiology , Lymphoma, B-Cell/complications , Lymphoma, B-Cell/diagnosis , Central Nervous System Neoplasms/complications , Central Nervous System Neoplasms/diagnosis , Fatal Outcome , Lymphoma, Non-Hodgkin/complications , Lymphoma, Non-Hodgkin/diagnosis , Vasculitis, Central Nervous System
8.
Australas Med J ; 4(9): 500-6, 2011.
Article in English | MEDLINE | ID: mdl-23393542

ABSTRACT

BACKGROUND: The design of custom contoured cushions manufactured in flexible polyurethane foams is an option to improve positioning and comfort for people with disabilities that spend most of the day seated in the same position. These surfaces increase the contact area between the seat and the user. This fact contributes to minimise the local pressures that can generate problems like decubitus ulcers. The present research aims at establishing development routes for custom cushion production to wheelchair users. This study also contributes to the investigation of Computer Numerical Control (CNC) machining of flexible polyurethane foams. METHOD: The proposed route to obtain the customised seat began with acquiring the user's contour in adequate posture through plaster cast. To collect the surface geometry, the cast was three-dimensionally scanned and manipulated in CAD/CAM software. CNC milling parameters such as tools, spindle speeds and feed rates to machine flexible polyurethane foams were tested. These parameters were analysed regarding the surface quality. The best parameters were then tested in a customised seat. The possible dimensional changes generated during foam cutting were analysed through 3D scanning. Also, the customised seat pressure and temperature distribution was tested. RESULTS: The best parameters found for foams with a density of 50kg/cm(3) were high spindle speeds (24000 rpm) and feed rates between 2400-4000mm/min. Those parameters did not generate significant deformities in the machined cushions. The custom contoured cushion satisfactorily increased the contact area between wheelchair and user, as it distributed pressure and heat evenly. CONCLUSION: Through this study it was possible to define routes for the development and manufacturing of customised seats using direct CNC milling in flexible polyurethane foams. It also showed that custom contoured cushions efficiently distribute pressure and temperature, which is believed to minimise tissue lesions such as pressure ulcers.

9.
Sensors (Basel) ; 10(8): 7263-86, 2010.
Article in English | MEDLINE | ID: mdl-22163602

ABSTRACT

Computer numerically controlled (CNC) machines have evolved to adapt to increasing technological and industrial requirements. To cover these needs, new generation machines have to perform monitoring strategies by incorporating multiple sensors. Since in most of applications the online Processing of the variables is essential, the use of smart sensors is necessary. The contribution of this work is the development of a wireless network platform of reconfigurable smart sensors for CNC machine applications complying with the measurement requirements of new generation CNC machines. Four different smart sensors are put under test in the network and their corresponding signal processing techniques are implemented in a Field Programmable Gate Array (FPGA)-based sensor node.


Subject(s)
Computer Communication Networks , Monitoring, Ambulatory/instrumentation , Signal Processing, Computer-Assisted , Wireless Technology/instrumentation , Artificial Intelligence , Equipment Design , Monitoring, Ambulatory/methods , Reproducibility of Results , Software
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