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1.
Rev. colomb. anestesiol ; 49(2): e201, Apr.-June 2021. tab, graf
Article in English | LILACS, COLNAL | ID: biblio-1251498

ABSTRACT

Abstract Introduction The analysis of the electrical activity of the brain using scalp electrodes with electroencephalography (EEG) could reveal the depth of anesthesia of a patient during surgery. However, conventional EEG equipment, due to its price and size, are not a practical option for the operating room and the commercial units used in surgery do not provide access to the electrical activity. The availability of low-cost portable technologies could provide for further research on the brain activity under general anesthesia and facilitate our quest for new markers of depth of anesthesia. Objective To assess the capabilities of a portable EEG technology to capture brain rhythms associated with the state of consciousness and the general anesthesia status of surgical patients anesthetized with propofol. Methods Observational, cross-sectional study that reviewed 10 EEG recordings captured using OpenBCI portable low-cost technology, in female patients undergoing general anesthesia with propofol. The signal from the frontal electrodes was analyzed with spectral analysis and the results were compared against the reports in the literature. Results The signal captured with frontal electrodes, particularly α rhythm, enabled the distinction between resting with eyes closed and with eyes opened in a conscious state, and sustained anesthesia during surgery. Conclusions It is possible to differentiate a resting state from sustained anesthesia, replicating previous findings with conventional technologies. These results pave the way to the use of portable technologies such as the OpenBCI tool, to explore the brain dynamics during anesthesia.


Resumen Introducción El análisis de la actividad eléctrica cerebral mediante electrodos ubicados sobre el cuero cabelludo con electroencefalografía (EEG) podría permitir conocer la profundidad anestésica de un paciente durante cirugía. Sin embargo, los equipos de EEG convencionales, por su precio y tamaño, no son una alternativa práctica en quirófanos y los equipos comerciales usados en cirugía no permiten acceder a la actividad eléctrica. Disponer de tecnologías portables y de bajo costo aumentaría el número de investigaciones sobre la actividad cerebral bajo anestesia general y facilitaría la búsqueda de nuevos marcadores para la profundidad anestésica. Objetivo Evaluar la capacidad de una tecnología EEG portable de adquirir ritmos cerebrales relacionados con el estado consciente y el estado de anestesia general de pacientes en cirugía anestesiados con propofol. Métodos Estudio observacional de corte transversal en el que se analizaron datos de 10 registros EEG obtenidos mediante tecnología portable y de bajo costo OpenBCI, de pacientes de sexo femenino que fueron sometidas a anestesia general con propofol. La señal obtenida de los electrodos frontales se analizó mediante análisis espectral y se contrastaron los resultados con lo descrito en la literatura. Resultados La señal obtenida con electrodos frontales, especialmente el ritmo α, permitió diferenciar el reposo con ojos cerrados y ojos abiertos en estado consciente, del estado de mantenimiento de la anestesia durante cirugía. Conclusiones Se logra la diferenciación de estado de reposo y de mantenimiento de la anestesia replicando hallazgos previos de tecnologías convencionales. Estos resultados abren la posibilidad de utilizar las tecnologías portables como el OpenBCI para investigar la dinámica cerebral durante la anestesia.


Subject(s)
Humans , Spectrum Analysis , Technology , Electroencephalography , Anesthesia, General , Brain Mapping , Propofol , Observational Studies as Topic
2.
Acta bioquím. clín. latinoam ; 54(3): 279-284, set. 2020. tab
Article in Spanish | LILACS | ID: biblio-1130602

ABSTRACT

El azúcar de mesa, que se obtiene de la caña de azúcar, es el edulcorante más utilizado en la elaboración de los alimentos. El azúcar es importante en la obtención de energía, es necesario para la síntesis de ácidos grasos, de ácidos nucleicos, evita el estrés oxidativo y el desarrollo de anemia. Puede ocasionar caries, diabetes, obesidad, arteriosclerosis y otras patologías. En el presente trabajo se valoró el efecto que tiene la ingesta crónica de agua endulzada con sacarosa al 30% sobre el consumo de alimento balanceado, el perfil lipídico, la concentración de glucosa sérica, y sobre algunos marcadores del estado nutricional como el peso y las proteínas séricas totales, en machos de ratas Wistar. El agua endulzada con sacarosa al 30% se administró a un grupo de 9 ratas Wistar durante 3 meses y se tomó como grupo control a un grupo de 9 ratas que bebieron agua natural. El consumo de alimentos por ambos grupos, así como los marcadores de química sanguínea se analizaron al final del tratamiento. Los niveles de glucosa, lípidos y proteínas séricas totales se midieron mediante espectroscopía. Los resultados mostraron que el consumo de agua endulzada con sacarosa al 30% redujo en más de un 90% el consumo de alimento balanceado; sin embargo, no afectó el perfil lipídico ni el nivel de glucosa en sangre, así como tampoco el nivel de proteínas séricas totales. El consumo de agua endulzada con sacarosa podría provocar desnutrición a largo plazo ya que ocasiona una reducción en la ingesta de alimento rico en nutrientes.


Sugar, obtained from sugarcane, is the most commonly used sweetener in food processing. Sugar is an important food for energy generation and it is necessary for the synthesis of fatty acids and nucleic acids. It prevents oxidative stress and anemia development. However, its consumption can cause dental caries, diabetes, obesity, arteriosclerosis and other pathologies. In the present work, the effect of chronic intake of water sweetened with 30% sucrose on balanced food consumption, lipid profile, serum glucose concentration, as well as some markers of nutritional status such as weight and total serum proteins was assessed in male Wistar rats. The water sweetened with 30% sucrose was administered to a group of 9 Wistar rats for 3 months, having 9 rats as a control group that drank natural water. Food consumption between both groups as well as blood chemistry markers were analyzed at the end of the treatment. Glucose, lipid levels as well as total serum proteins were measured by spectroscopy. The results showed that the consumption of water sweetened with 30% sucrose reduced the consumption of balanced food by more than 90%, however, it did not affect the lipid profile, the level of glucose in the blood or the level of total serum proteins concentration. Consumption of sucrose-sweetened water could lead to long-term malnutrition by reducing the intake of nutrient-rich food.


O açúcar comum, obtido a partir da cana de açúcar, é o adoçante mais utilizado na elaboração dos alimentos. O açúcar é importante para a geração de energia; necessário para a síntese de ácidos graxos e de ácidos nucleicos. Previne o estresse oxidativo e o desenvolvimento de anemia. No entanto, seu consumo pode causar cárie dentária, diabetes, obesidade, arteriosclerose e outras patologias. No presente trabalho, foi avaliado o efeito da ingestão crônica de água adoçada com sacarose a 30% sobre o consumo de alimentos ricos em nutrientes, perfil lipídico, concentração sérica de glicose e alguns marcadores do estado nutricional, como o peso. e as proteínas séricas totais em ratos Wistar machos. A água adoçada com sacarose a 30% foi administrada a um grupo de 9 ratos Wistar por 3 meses, tendo como grupo controle um grupo de 9 ratos que beberam água natural. O consumo de alimentos entre os dois grupos e os marcadores de química sanguínea foram analisados no final do tratamento. Os níveis de glicose, lipídios e proteínas séricas totais foram medidos por espectroscopia. Os resultados mostraram que o consumo de água adoçada com sacarose a 30% reduziu em mais de 90% o consumo de alimentos ricos em nutrientes, no entanto, não afetou o perfil lipídico, o nível de glicose em sangue nem o nível de proteínas séricas totais. O consumo de água adoçada com sacarose poderia levar à desnutrição no longo prazo, visto que produz uma redução na ingestão de alimentos ricos em nutrientes.


Subject(s)
Humans , Animals , Male , Female , Arteriosclerosis , Spectrum Analysis , Blood , Nucleic Acids , Eating , Rats, Wistar , Dietary Sucrose , Saccharum , Control , Fatty Acids , Anemia , Sucrose , Therapeutics , Water , Affect , Dental Caries , Malnutrition , Growth and Development , Diabetes Mellitus , Sugars , Food , Food Handling
5.
Article in English | WPRIM | ID: wpr-782106

ABSTRACT

200 µm, a circumference > 60 degrees, and a cap thickness < 450 µm. The percentage distributions of CT pixel attenuation ≤ 20, 30, 40, and 50 HU were calculated using quantitative histogram analysis.RESULTS: A total of 271 transverse sections were co-registered between CCTA and pathological analysis. Overall, 26 lipid cores and 16 fibrous plaques were identified by pathological analysis. There was no significant difference in median CT attenuation between the lipid and fibrous plaques (51 HU [interquartile range, 46–63] vs. 57 HU [interquartile range, 50–64], p = 0.659). The median percentage of CT pixel attenuation ≤ 30 HU accounted for 11% (5–17) of lipid-core plaques and 0% (0–2) of fibrous plaques (p < 0.001). The sensitivity and specificity of the method for diagnosing lipid plaques by the average CT pixel attenuation ≤ 30 HU were 80.8% and 87.5%, respectively. The area under the receiver operator characteristics curve was 0.898 (95% confidence interval: 0.765–0.970; 3.0% was the best cut-off value). The diagnostic performance was significantly higher than those of the average pixel CT attenuation percentages ≤ 20, 40, and 50 HU and the mean CT attenuation (p < 0.05).CONCLUSION: In in vivo conditions, with the pathological lipid core as the gold standard, quantification of the percentage of average CT pixel attenuation ≤ 30 HU in the histogram can be useful for accurate identification of lipid plaques.


Subject(s)
Angiography , Coronary Disease , Coronary Vessels , Diagnosis , Heart Transplantation , Humans , Methods , Sensitivity and Specificity , Spectrum Analysis
6.
Article in English | WPRIM | ID: wpr-811428

ABSTRACT

OBJECTIVES: This study investigated the indirect effect of calcium-enriched mixture (CEM) cement and mineral trioxide aggregate (MTA), as 2 calcium silicate-based hydraulic cements, on human dental pulp stem cells (hDPSCs) through different dentin thicknesses.MATERIALS AND METHODS: Two-chamber setups were designed to simulate indirect pulp capping (IPC). Human molars were sectioned to obtain 0.1-, 0.3-, and 0.5-mm-thick dentin discs, which were placed between the 2 chambers to simulate an IPC procedure. Then, MTA and CEM were applied on one side of the discs, while hDPSCs were cultured on the other side. After 2 weeks of incubation, the cells were removed, and cell proliferation, morphology, and attachment to the discs were evaluated under scanning electron microscopy (SEM). Energy-dispersive X-ray (EDXA) spectroscopy was performed for elemental analysis. Alkaline phosphatase (ALP) activity was assessed quantitatively. The data were analyzed using the Kruskal-Wallis and Mann-Whitney tests.RESULTS: SEM micrographs revealed elongated cells, collagen fibers, and calcified nucleations in all samples. EDXA verified that the calcified nucleations consisted of calcium phosphate. The largest calcifications were seen in the 0.1-mm-thick dentin subgroups. There was no significant difference in ALP activity across the CEM subgroups; however, ALP activity was significantly lower in the 0.1-mm-thick dentin subgroup than in the other MTA subgroups (p < 0.05).CONCLUSIONS: The employed capping biomaterials exerted biological activity on hDPSCs, as shown by cell proliferation, morphology, and attachment and calcific precipitations, through 0.1- to 0.5-mm-thick layers of dentin. In IPC, the bioactivity of these endodontic biomaterials is probably beneficial.


Subject(s)
Alkaline Phosphatase , Biocompatible Materials , Calcium , Cell Proliferation , Collagen , Dental Pulp Capping , Dental Pulp , Dentin , Endodontics , Humans , Microscopy, Electron, Scanning , Miners , Molar , Pemetrexed , Spectrum Analysis , Stem Cells
7.
Article in Chinese | WPRIM | ID: wpr-828889

ABSTRACT

OBJECTIVE@#To develop a fast, sensitive and cost-effective method based on resonance light scattering (RLS) for characterization of protein solubility to facilitate detection of changes in solubility of mutant proteins.@*METHODS@#We examined the response curve of RLS intensities to the protein concentrations in synchronous scanning mode. The curve intersection points were searched to predict the maximal concentrations of the protein in dispersion state, which defined the solubility of the protein in this given state. Bovine serum albumin (BSA, 0-50 g/L) was used as the model to investigate the influences of pH values (6.5, 7.0, and 7.4) and salt concentrations (0.05, 0.10, 0.15, and 0.20 mol/L) on the determined solubility. The solubility of glutathione S-transferase isoenzymes alpha (GSTA, 0-27.0 g/L) and Mμ (GSTM, 0-20.0 g/L) were estimated for comparison. The RLS-based method was used to determine the solubility of uricase (MGU, 0-0.4 g/L) to provide assistance in improving the solubility of its mutants.@*RESULTS@#We identified two intersection points in the RLS response curves of the tested proteins, among which the lower one represented an approximation of the maximal concentration (or the solubility of the protein) in single molecular dispersion, and the higher one the saturated concentration of the protein in multiple molecular aggregation. In HEPES buffer, the two intersection points of BSA (isoelectric point 4.6) both increased with the increase of pH (6.5-7.4), and their values were ~1.2 g/L and ~33 g/L at pH 7.4, respectively; the latter concentration approached the solubility of commercial BSA in the same buffer at the same pH. The addition of NaCl reduced the values of the two intersection points, and increasing salt ion concentration decreased the values of the lower intersection points. Further characterizations of GSTA and GSTM showed that the low concentration intersection points of the two proteins were ~0.7 g/L and ~0.8 g/L, and their high concentration intersection points were ~10 g/L and ~11 g/L, respectively, both lower than those of BSA, indicating the feasibility of the direct characterization of protein solubility by RLS. The two concentration intersection points of MGU were 0.24 g/L and 0.30 g/L, respectively, and the low concentration intersection point of its selected mutant was increased by 2 times.@*CONCLUSIONS@#RLS allows direct characterization of the solubility of macromolecular proteins. This method, which is simple and sensitive and needs only a small amount of proteins, has a unique advantage for rapid comparison of solubility of low-abundance protein mutants.


Subject(s)
Hydrogen-Ion Concentration , Light , Scattering, Radiation , Solubility , Spectrum Analysis
8.
Article in English | LILACS, BBO | ID: biblio-1101284

ABSTRACT

Abstract Objective: To assess the cytotoxicity, surface morphology, elemental compositions and chemical characterization of two commonly used luting cement. Material and Methods: The two luting types of cement used were Elite Cement® and Hy-Bond Resiglass®. Freshly mixed (n=6) and set form (n=6) of each cement was placed in medium to obtain extracts. The extract from each sample was exposed to L929 mouse fibroblasts (1x104cells/well). Alamar Blue Assay assessed cell viability. Surface morphology and elemental composition were evaluated using scanning electron microscopy and energy dispersive spectroscopy. The chemical characterization was performed by Fourier Transform Infrared Spectroscopy. One-way ANOVA and post-hoc Tukey analysis were conducted to assess results. Results: Hy-Bond Resiglass® was the more cytotoxic of the two types of cement in both freshly mixed (68.10 +5.16; p<0.05) and set state (87.58 +4.86; p<0.05), compared to Elite Cement® both freshly mixed (77.01 +5.45; p<0.05) and set state (89.39 +5.66; p<0.05). Scanning electron microscopy revealed a more irregular and porous structure in Hy-Bond Resiglass® compared to Elite Cement®. Similarly, intense peaks of aluminium, tungsten and fluorine were observed in energy dispersive spectroscopy in Hy-Bond Resiglass. Conclusion: All these three elements (aluminium, tungsten and fluorine) have cytotoxic potential. The Fourier transform infrared spectroscopy revealed the presence of hydroxyethyl methacrylate in Hy-Bond Resiglass®, which has a cytotoxic potential.


Subject(s)
Animals , Mice , Rats , Zinc Phosphate Cement , In Vitro Techniques/methods , Dental Cements , Fibroblasts , Pakistan , Rats , Spectrum Analysis , Tungsten , Microscopy, Electron, Scanning , Analysis of Variance , Spectroscopy, Fourier Transform Infrared
9.
Biociencias ; 15(1): 73-78, jun.2020.
Article in Spanish | LILACS, COLNAL | ID: biblio-1122956

ABSTRACT

Introducción: La oximetría cerebral no invasiva utiliza la tecnología NIRS ("near infrared spectroscopy") para medir la saturación de oxígeno en una pequeña región de los vasos cerebrales corticales. Refleja el 75% volumen de oxigenación cerebral venosa y el 25% volumen de oxigenación cerebral arterial. Objetivo: Hacer una descripción breve sobre oximetría cerebral no invasiva mediante la tecnología NIRS ("near infrared spectroscopy"). Aunque esta técnica se describió hace más de 25 años, su uso es cada vez más frecuente siendo un fenómeno reciente. Comentarios: La saturación regional cerebral de oxígeno (rSO2c), al igual que la saturación pulsátil arterial periférica de oxígeno, se mide por espectrometría. Se basa en el hecho de que la hemoglobina oxigenada absorbe menos luz roja y más luz infrarroja que la hemoglobina. Es un método sencillo para identificar el límite inferior de la autorregulación, el punto por debajo del cual el flujo sanguíneo cerebral y la oxigenación tisular se hacen dependientes de la presión. Conclusiones: Los valores obtenidos de rSO2c representan el estado de oxigenación de los cromóforos del lecho vascular cerebral del compartimento venoso. Los cambios en la oximetría cerebral dependen del balance entre aporte y consumo de oxígeno.


Introduction: Non-invasive cerebral oximetry uses NIRS ("near infrared spectroscopy") technology to measure oxygen saturation in a small region of cortical cerebral vessels. It reflects 75% volume of venous cerebral oxygenation and 25% volume of arterial cerebral oxygenation. Objective: To make a brief description about non-invasive cerebral oximetry using NIRS technology ("near infrared spectroscopy"). Although this technique was described more than 25 years ago, its use is increasingly frequent being a recent phenomenon. Comments: Regional cerebral oxygen saturation (rSO2c), like peripheral arterial pulsatile oxygen saturation, is measured by spectrometry. It is based on the fact that oxygenated hemoglobin absorbs less red light and more infrared light than hemoglobin. It is a simple method to identify the lower limit of self-regulation, the point below which cerebral blood flow and tissue oxygenation become pressure dependent. Conclusions: The values ​​obtained from rSO2c represent the oxygenation state of the chromophores of the cerebral vascular bed of the venous compartment. Changes in cerebral oximetry depend on the balance between oxygen intake and consumption.


Subject(s)
Humans , Child, Preschool , Child , Spectrum Analysis , Bacteria , Cerebrovascular Circulation , Environment and Public Health
10.
Prensa méd. argent ; 105(11): 836-841, dic2019. graf
Article in English | LILACS, BINACIS | ID: biblio-1049996

ABSTRACT

Composite membrane as a flexible materials have found diverse applications in industrial and biomedical simultaneously, the recent studies have shown intrinsic improvement for membrane properties by inclusion of nanoparticles as a fillers with high portion ratio in inorganic polymers, the combination between two parts polymer and filler is as a result of collection the advantage of two component systems parts together. In this work, samples of polyvinyl alcohol (PVA)-nanoHaydroxyapatite (nHAp) composites were prepared by using casting method. The effects of addition of (nHAp) with different concentration on the optical properties of (PVA- nHAp) composite membrane have been studied by using wavelength range (220-820) nm. The absorption spectra, transmittance spectra, absorption coefficient, energy gap, refractive index, optical conductivity and extinction coefficient have been determined. The results show that the optical constants change with the increase of nHPA concentrations.


Subject(s)
Polyvinyl Alcohol , Spectrum Analysis , Product Synthesis , Nanoparticles , Materials Science , Hydroxyapatites
11.
Prensa méd. argent ; 105(9 especial): 571-575, oct 2019. fig, tab
Article in English | LILACS, BINACIS | ID: biblio-1046618

ABSTRACT

The mobility of teeth in terms of periotestometry and hydration of periodontal tissues in terms of bioimpedance spectrometry were studied in healthy volunteers without dental and concomitant somatic diseases. It was found that teeth of these subjects have both low and pathological mobility. It was also revealed as increased hydration (edema), indicating the presence of inflammation, and reduced hydration, indicating atrophic processes in periodontal tissues. A comparison of the data of periotestometry and bioimpedance spectrometry showed that the indicators of mobility of the teeth and hydration of the periodontal tissues reflect different characteristics of the functional state of dentoalveolar system, and can be used as complementary in the diagnostic studies.


Subject(s)
Periodontal Diseases/diagnosis , Spectrum Analysis , Tooth Mobility/diagnosis , Periodontium/anatomy & histology , Organism Hydration Status
12.
Prensa méd. argent ; 105(9 especial): 644-651, oct 2019. fig
Article in English | LILACS, BINACIS | ID: biblio-1046879

ABSTRACT

The article introduces the findings of the analysis of the existing approaches to the development of mathematical models of acoustic heart phenomena. The analysis of mathematical methods that can be used to model heart sounds has been performed with the use of reference signals from the 3M Open Library (Littmann Library) and a set of signals obtained by the authors during their previous scientific efforts. The analysis findings have allowed revealing the approaches and methods that are most suitable for developing the mathematical models of human phonocardiograms (normal and pathological) for further research efforts meant to develop methods to single out heart beats against the high level of interference and creating intervalograms to characterize the heart rate at the current moments of time. In addition to the generation of model phonocardiograms, the article reviews the methods to analyze model and real-life phonocardiograms with the assessment of an input from random and deterministic components.


Subject(s)
Humans , Phonocardiography/instrumentation , Spectrum Analysis , Acoustics , Models, Statistical , Heart Rate Determination/methods , Heart/physiology
13.
Pesqui. bras. odontopediatria clín. integr ; 19(1): 4773, 01 Fevereiro 2019. tab, graf
Article in English | LILACS, BBO | ID: biblio-998267

ABSTRACT

Objective: To elicit the structure of isolated compounds from roots of sidaguri (Sida rhombifolia Linn). Material and Methods: Several organic standard protocols were involved, including extraction, fractionation, and phytochemical testing. Further spectroscopy methods, FTIR and 1HNMR, were used to determine the predicted structure of molecules, while their ability to inhibit cyclooxygenase (COX 1 and 2) were tested using in vitro method. Results: Overall assessments showed that the structure of the sidaguri is a long chain aliphatic carboxylic acid and identified as Z-3, 6, 6 trimethylhept-2-en-1-ol (T12) and nonanoic (T13). Both isolates significantly inhibit COX-1 and COX-2 non-selectively (the COX-1/COX-2 ratio for T12 was 0.91 and 0.82; while COX-1/COX-2 ratio for T13 was 0.89 and 0.87 at concentrations of 0.05 and 0.025 µg/mL respectively). Conclusion: The active compounds of Sidaguri have antiinflammatory effect by inhibiting COX non-selectively.


Subject(s)
Spectrum Analysis/methods , Cyclooxygenase 1 , Cyclooxygenase 2 , Anti-Inflammatory Agents , In Vitro Techniques/methods , Indonesia
14.
Pesqui. bras. odontopediatria clín. integr ; 19(1): 4990, 01 Fevereiro 2019. tab
Article in English | LILACS, BBO | ID: biblio-998269

ABSTRACT

Objective: To determine and compare the corrosion resistance (based on the release of nickel and chromium in artificial saliva) of various brands of stainless steel brackets after thermal recycling by direct flaming. Material and Methods: This research study employed 40 stainlesssteel maxillary premolar brackets from different brands (Ormco, GAC, Versadent, S-Ortho, and Protect), which were divided into 5 groups consisting of 8 brackets. The nickel and chromium content of the metal brackets were analyzed by inductively coupled plasma mass spectrometry (ICP-MS), conducted before immersion. For the first treatment, each group was immersed in artificial saliva without direct flaming (recycling); for the second treatment, each group was immersed in artificial saliva with direct flaming (recycling) for 30 days in a pH-neutral (pH=7) solution. ICP-MS was employed to analyze the nickel and chromium released in saliva. The mean differences were measured with Wilcoxon, Kruskal Wallis test, and Post-Hoc Mann Whitney test. Differences were considered statistically significant when p-value<0.05. Results: The mean corrosion resistance based on the nickel content released by the new brackets was 99.95%, 99.87%, 87.09%, 90.58%, and 90.26% for groups A, B, C, D, and E, respectively. The mean corrosion resistance based on the nickel content released by the recycled brackets was 99.90%, 99.80%, 98.19%, 89.76%, and 72.82%, respectively. There was a significant difference in corrosion resistance among the 5 groups after recycling by direct flaming and between new and recycled brackets in each group. Conclusion: The corrosion resistance of the brackets in groups A (Ormco), B (GAC), D (S-Ortho), and E (Protect) decreased after thermal recycling by direct flaming. The Ormco brackets had the highest corrosion resistance after thermal recycling by direct faming.


Subject(s)
Stainless Steel , Chromium , Orthodontic Brackets , Dental Etching , Nickel , Spectrum Analysis/methods , Indonesia
15.
Article in English | WPRIM | ID: wpr-719316

ABSTRACT

OBJECTIVE: The aim of this study was to analyze the surface composition, roughness, and relative friction of metal clips from various ceramic self-ligating brackets. METHODS: Six kinds of brackets were examined. The control group (mC) consisted of interactive metal self-ligating brackets while the experimental group (CC, EC, MA, QK, and WA) consisted of interactive ceramic self-ligating brackets. Atomic force microscopy-lateral force microscopy and scanning electron microscopy-energy-dispersive X-ray spectroscopy were used to analyze the surface of each bracket clip. RESULTS: All the clips in the experimental groups were coated with rhodium except for the QK clip. The results showed that the QK clip had the lowest average roughness on the outer surface, followed by the MA, EC, WA, and CC clips. However, the CC clip had the lowest average roughness on the inner surface, followed by the QK, WA, MA, and EC clips. The QK clip also had the lowest relative friction on the outer surface, followed by the MA, EC, CC, and WA clips. Likewise, the CC clip had the lowest relative friction on the inner surface, followed by the QK, WA, MA, and EC clips. CONCLUSIONS: The surface roughness and relative friction of the rhodium-coated clips were generally higher than those of the uncoated clips.


Subject(s)
Ceramics , Friction , Microscopy, Atomic Force , Rhodium , Spectrum Analysis
16.
Article in English | WPRIM | ID: wpr-719591

ABSTRACT

OBJECTIVE: To compare the lumbar vertebral bone marrow fat-signal fractions obtained from six-echo modified Dixon sequence (6-echo m-Dixon) with those from single-voxel magnetic resonance spectroscopy (MRS) in patients with low back pain. MATERIALS AND METHODS: Vertebral bone marrow fat-signal fractions were quantified by 6-echo m-Dixon (repetition time [TR] = 7.2 ms, echo time (TE) = 1.21 ms, echo spacing = 1.1 ms, total imaging time = 50 seconds) and single-voxel MRS measurements in 25 targets (23 normal bone marrows, two focal lesions) from 24 patients. The point-resolved spectroscopy sequence was used for localized single-voxel MRS (TR = 3000 ms, TE = 35 ms, total scan time = 1 minute 42 seconds). A 2 × 2 × 1.5 cm³ voxel was placed within the normal L2 or L3 vertebral body, or other lesions including a compression fracture or metastasis. The bone marrow fat spectrum was characterized on the basis of the magnitude of measurable fat peaks and a priori knowledge of the chemical structure of triglycerides. The imaging-based fat-signal fraction results were then compared to the MRS-based results. RESULTS: There was a strong correlation between m-Dixon and MRS-based fat-signal fractions (slope = 0.86, R² = 0.88, p 20%). CONCLUSION: Given its excellent agreement with single-voxel-MRS, 6-echo m-Dixon can be used for visual and quantitative evaluation of vertebral bone marrow fat in daily practice.


Subject(s)
Bone Marrow , Evaluation Studies as Topic , Fractures, Compression , Humans , Low Back Pain , Magnetic Resonance Spectroscopy , Neoplasm Metastasis , Spectrum Analysis , Spine , Triglycerides
17.
Article in English | WPRIM | ID: wpr-719461

ABSTRACT

OBJECTIVE: We undertook this study to investigate the discriminant metabolites in urine from patients with established rheumatoid arthritis (RA), systemic lupus erythematosus (SLE), and from healthy individuals. METHODS: Urine samples were collected from 148 RA patients, 41 SLE patients and 104 healthy participants. The urinary metabolomic profiles were assessed using 1H nuclear magnetic resonance spectroscopy. The relationships between discriminant metabolites and clinical variables were assessed. Collagen-induced arthritis was induced in mice to determine if a choline-rich diet reduces arthritis progression. RESULTS: The urinary metabolic fingerprint of patients with established RA differs from that of healthy controls and SLE patients. Markers of altered gut microbiota (trimethylamine-N-oxide, TMAO), and oxidative stress (dimethylamine) were upregulated in patients with RA. In contrast, markers of mitochondrial dysfunction (citrate and succinate) and metabolic waste products (p-cresol sulfate, p-CS) were downregulated in patients with RA. TMAO and dimethylamine were negatively associated with serum inflammatory markers in RA patients. In particular, patients with lower p-CS levels exhibited a more rapid radiographic progression over two years than did those with higher p-CS levels. The in vivo functional study demonstrated that mice fed with 1% choline, a source of TMAO experienced a less severe form of collagen-induced arthritis than did those fed a control diet. CONCLUSION: Patients with RA showed a distinct urinary metabolomics pattern. Urinary metabolites can reflect a pattern indicative of inflammation and accelerated radiographic progression of RA. A choline-rich diet reduces experimentally-induced arthritis. This finding suggests that the interaction between diet and the intestinal microbiota contributes to the RA phenotype.


Subject(s)
Animals , Arthritis , Arthritis, Experimental , Arthritis, Rheumatoid , Choline , Dermatoglyphics , Diet , Gastrointestinal Microbiome , Healthy Volunteers , Humans , Inflammation , Lupus Erythematosus, Systemic , Magnetic Resonance Spectroscopy , Metabolome , Metabolomics , Mice , Oxidative Stress , Phenotype , Spectrum Analysis , Waste Products
18.
Article in English | WPRIM | ID: wpr-719401

ABSTRACT

Monitoring cerebral oxygenation using a near infrared spectroscopy (NIRS) device is useful for estimating cerebral hypoperfusion and is available during liver transplantation (LT). However, high serum bilirubin concentration can interfere with NIRS because bilirubin absorbs near infrared light. We report a patient who underwent LT with a diagnosis of vanishing bile duct syndrome, whose regional cerebral oxygen saturation (rSO₂) remained below 15% even with alert mental status and SpO2₂ value of 99%. The rSO₂ values were almost fixed at the lowest measurable level throughout the intra- and postoperative period. We report a case of erroneously low rSO₂ values during the perioperative period in a liver transplant recipient which might be attributable to skin pigmentation rather than higher serum bilirubin concentration.


Subject(s)
Bile Ducts , Bile , Bilirubin , Diagnosis , Humans , Hyperbilirubinemia , Hypoxia, Brain , Liver Transplantation , Liver , Oxygen , Perioperative Period , Postoperative Period , Skin Pigmentation , Spectrum Analysis , Transplant Recipients
19.
Article in English | WPRIM | ID: wpr-761422

ABSTRACT

PURPOSE: To evaluate the influence of cyclic loading on phase transformation of zirconia abutments and to compare the effectiveness of three different quantitative ageing assessment techniques. MATERIALS AND METHODS: Thirty two Y-TZP prostheses fabricated from two brands, InCoris ZI and Ceramill ZI, were cemented to titanium bases and equally divided into two subgroups (n=8): control group without any treatment and aged group with cyclic loading between 20 N and 98 N for 100,000 cycles at 4 Hz in distilled water at 37℃. The tetragonal-to-monoclinic phase transformation was assessed by (i) conventional x-ray diffraction (XRD), (ii) micro x-ray diffraction (µXRD), and (iii) micro-Raman spectroscopy. The monoclinic-phase fractions (M%) were compared by two-way ANOVA. RESULTS: InCoris Zi presented significantly higher M% than Ceramill Zi in both control and aged groups (P<.001). Both materials exhibited significant phase transformation with monoclinicphase of 1 to 3% more in aged groups than controls for all thre e assessment techniques. The comparable M% was quantified by both µXRD and XRD. The highest M% was assessed with micro-Raman. CONCLUSION: Cyclic loading produced significant phase transformation in tested Y-TZP prostheses. The micro-Raman spectroscopy could be used as an alternative to XRD and µXRD.


Subject(s)
Prostheses and Implants , Spectrum Analysis , Titanium , Water , X-Ray Diffraction
20.
Article in English | WPRIM | ID: wpr-761332

ABSTRACT

BACKGROUND: Lead (Pb) exposure in shooting ranges has been reduced by various measures such as jacketed ammunition and lead-free primers. Nevertheless, this may lead to exposure to other metals, potentially resulting in adverse health effects. METHODS: In a cross-sectional study, 35 subjects from seven different shooting ranges were studied: four shooting instructors, 10 police officers, 15 Special Forces, and six maintenance staff members. Metals and metalloids were determined in blood and urine by inductively coupled plasma–mass spectrometry. RESULTS: The concentrations of most elements did not differ significantly between groups or compared to reference values, except for Sb and Pt in urine and Pb in blood. Mean values for Sb were considerably higher in urine from the Special Forces (0.34 μg/L), the maintenance staff (0.13 μg/L), and shooting instructors (0.32 μg/L) compared to the police officers before shooting (0.06 μg/L) and a Belgian reference value (0.04 μg/L). For Pt, the Special Forces showed higher mean urinary concentrations (0.078 μg/L) compared to a Belgian reference value (<0.061 μg/L). Mean values for blood lead were markedly higher in the Special Forces (3.9 μg/dL), maintenance staff (5.7 μg/dL), and instructors (11.7 μg/dL) compared to police officers (1.4 μg/dL). One instructor exceeded the biological exposure index for blood Pb (38.8 μg/dL). CONCLUSION: Since both Pb and Sb were found to be higher in shooting range employees, especially among frequent shooters, it is advisable to provide appropriate protective equipment, education, and medical follow-up for shooting range personnel in addition to careful choice of ammunition.


Subject(s)
Cross-Sectional Studies , Education , Environmental Monitoring , Follow-Up Studies , Humans , Metalloids , Metals , Occupational Exposure , Occupational Health , Police , Reference Values , Spectrum Analysis
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