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1.
Nat Commun ; 15(1): 4025, 2024 May 13.
Artículo en Inglés | MEDLINE | ID: mdl-38740804

RESUMEN

Intracellular membranes composing organelles of eukaryotes include membrane proteins playing crucial roles in physiological functions. However, a comprehensive understanding of the cellular responses triggered by intracellular membrane-focused oxidative stress remains elusive. Herein, we report an amphiphilic photocatalyst localised in intracellular membranes to damage membrane proteins oxidatively, resulting in non-canonical pyroptosis. Our developed photocatalysis generates hydroxyl radicals and hydrogen peroxides via water oxidation, which is accelerated under hypoxia. Single-molecule magnetic tweezers reveal that photocatalysis-induced oxidation markedly destabilised membrane protein folding. In cell environment, label-free quantification reveals that oxidative damage occurs primarily in membrane proteins related to protein quality control, thereby aggravating mitochondrial and endoplasmic reticulum stress and inducing lytic cell death. Notably, the photocatalysis activates non-canonical inflammasome caspases, resulting in gasdermin D cleavage to its pore-forming fragment and subsequent pyroptosis. These findings suggest that the oxidation of intracellular membrane proteins triggers non-canonical pyroptosis.


Asunto(s)
Inflamasomas , Proteínas de la Membrana , Oxidación-Reducción , Piroptosis , Humanos , Inflamasomas/metabolismo , Proteínas de la Membrana/metabolismo , Estrés Oxidativo , Catálisis , Estrés del Retículo Endoplásmico , Peróxido de Hidrógeno/metabolismo , Proteínas de Unión a Fosfato/metabolismo , Radical Hidroxilo/metabolismo , Mitocondrias/metabolismo , Membranas Intracelulares/metabolismo , Péptidos y Proteínas de Señalización Intracelular/metabolismo , Ratones , Animales , Procesos Fotoquímicos , Pliegue de Proteína , Caspasas/metabolismo , Gasderminas
2.
BMC Neurol ; 24(1): 14, 2024 Jan 02.
Artículo en Inglés | MEDLINE | ID: mdl-38166838

RESUMEN

BACKGROUND: Dilated perivascular spaces (DPVS), known as one of imaging markers in cerebral small vessel disease, may be found in patients with moyamoya disease (MMD). However, little is known about DPVS in MMD. The purpose of this study was to investigate the distribution pattern of dPVS in children and adults with MMD and determine whether it is related to steno-occlusive changes of MMD. METHODS: DPVS was scored in basal ganglia (BG) and white matter (WM) on T2-weighted imaging, using a validated 4-point semi-quantitative score. The degree of dPVS was classified as high (score > 2) or low (score ≤ 2) grade. The steno-occlusive changes on MR angiography (MRA) was scored using a validated MRA grading. Asymmetry of DPVS and MRA grading was defined as a difference of 1 grade or higher between hemispheres. RESULTS: Fifty-one patients with MMD (mean age 24.9 ± 21.1 years) were included. Forty-five (88.2%) patients had high WM-DPVS grade (degree 3 or 4). BG-DPVS was found in 72.5% of all patients and all were low grade (degree 1 or 2). The distribution patterns of DPVS degree in BG (P = 1.000) and WM (P = 0.767) were not different between child and adult groups. The asymmetry of WM-DPVS (26%) and MRA grade (42%) were significantly correlated to each other (Kendall's tau-b = 0.604, P < 0.001). CONCLUSIONS: DPVS of high grade in MMD is predominantly found in WM, which was not different between children and adults. The correlation between asymmetry of WM-DPVS degree and MRA grade suggests that weak cerebral artery pulsation due to steno-occlusive changes may affect WM-DPVS in MMD.


Asunto(s)
Enfermedad de Moyamoya , Sustancia Blanca , Adulto , Niño , Humanos , Preescolar , Adolescente , Adulto Joven , Persona de Mediana Edad , Enfermedad de Moyamoya/diagnóstico por imagen , Angiografía por Resonancia Magnética , Imagen por Resonancia Magnética/métodos , Sustancia Blanca/diagnóstico por imagen
3.
Molecules ; 29(2)2024 Jan 06.
Artículo en Inglés | MEDLINE | ID: mdl-38257211

RESUMEN

Suaeda glauca, a halophyte in the Amaranthaceae family, exhibits remarkable resilience to high salt and alkali stresses despite the absence of salt glands or vesicles in its leaves. While there is growing pharmacological interest in S. glauca, research on its secondary metabolites remains limited. In this study, chemical constituents of the aerial parts of S. glauca were identified using 1D- and 2D-NMR experiments, and its biological activity concerning hair loss was newly reported. Eight compounds, including alkaloids (1~3), flavonoids (4~6), and phenolics (7 and 8), were isolated. The compounds, except the flavonoids, were isolated for the first time from S. glauca. In the HPLC chromatogram, quercetin-3-O-ß-d-glucoside, kaempferol-3-O-ß-d-glucoside, and kaempferol were identified as major constituents in the extract of S. glauca. Additionally, the therapeutic potential of the extract of S. glauca and the isolated compounds 1~8 on the expressions of VEGF and IGF-1, as well as the regulation of Wnt/ß-catenin signaling, were evaluated in human follicle dermal papilla cells (HFDPCs) and human umbilical vein endothelial cells (HUVECs). Among the eight compounds, compound 4 was the most potent in terms of increasing the expression of VEGF and IGF-1 and the regulation of Wnt/ß-catenin. These findings suggest that S. glauca extract and its compounds are potential new candidates for preventing or treating hair loss.


Asunto(s)
Chenopodiaceae , Factor I del Crecimiento Similar a la Insulina , Humanos , Animales , Plantas Tolerantes a la Sal , beta Catenina , Factor A de Crecimiento Endotelial Vascular , Alopecia , Flavonoides/farmacología , Células Endoteliales de la Vena Umbilical Humana , Extractos Vegetales/farmacología
4.
Brief Bioinform ; 25(1)2023 11 22.
Artículo en Inglés | MEDLINE | ID: mdl-37991247

RESUMEN

The rapid growth of uncharacterized enzymes and their functional diversity urge accurate and trustworthy computational functional annotation tools. However, current state-of-the-art models lack trustworthiness on the prediction of the multilabel classification problem with thousands of classes. Here, we demonstrate that a novel evidential deep learning model (named ECPICK) makes trustworthy predictions of enzyme commission (EC) numbers with data-driven domain-relevant evidence, which results in significantly enhanced predictive power and the capability to discover potential new motif sites. ECPICK learns complex sequential patterns of amino acids and their hierarchical structures from 20 million enzyme data. ECPICK identifies significant amino acids that contribute to the prediction without multiple sequence alignment. Our intensive assessment showed not only outstanding enhancement of predictive performance on the largest databases of Uniprot, Protein Data Bank (PDB) and Kyoto Encyclopedia of Genes and Genomes (KEGG), but also a capability to discover new motif sites in microorganisms. ECPICK is a reliable EC number prediction tool to identify protein functions of an increasing number of uncharacterized enzymes.


Asunto(s)
Aprendizaje Profundo , Proteínas/química , Bases de Datos de Proteínas , Genoma , Aminoácidos
5.
Front Cardiovasc Med ; 10: 1253871, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37823175

RESUMEN

Background and Purpose: Cardiac biomarkers including, elevated troponin (ET) and prolonged heart rate-corrected QT (PQTc) interval on electrocardiography are known to frequent and have a prognostic significance in patients with acute ischemic stroke (AIS). However, it is still challenging to practically apply the results for appropriate risk stratification. This study evaluate whether combining ET and PQTc interval can better assess the long-term prognosis in AIS patients. Methods: In this prospectively registered observational study between May 2007 and December 2011, ET was defined as serum troponin-I ≥ 0.04 ng/ml and PQTc interval was defined as the highest tertile of sex-specific QTc interval (men ≥ 469 ms or women ≥ 487 ms). Results: Among the 1,668 patients [1018 (61.0%) men; mean age 66.0 ± 12.4 years], patients were stratified into four groups according to the combination of ET and PQTc intervals. During a median follow-up of 33 months, ET (hazard ratio [HR]: 4.38, 95% confidence interval [CI]: 2.94-6.53) or PQTc interval (HR: 1.53, 95% CI: 1.16-2.01) alone or both (HR: 1.77, 95% CI: 1.16-2.71) was associated with increased all-cause mortality. Furthermore, ET, PQTc interval alone or both was associated with vascular death, whereas only ET alone was associated with non-vascular death. Comorbidity burden, especially atrial fibrillation and congestive heart failure, and stroke severity gradually increased both with troponin value and QTc-interval. Conclusions: In patients with AIS, combining ET and PQTc interval on ECG enhances risk stratification for long-term mortality while facilitating the discerning ability for the burden of comorbidities and stroke severity.

6.
Environ Int ; 178: 108083, 2023 08.
Artículo en Inglés | MEDLINE | ID: mdl-37429057

RESUMEN

The structure of 9-year time series data for Sea Surface Temperature (SST), Chlorophyll a (Chl-a) and Total Suspended Solids (TSS), derived from the Visible Infrared Imaging Radiometer Suite (VIIRS), was examined in this study. Authors found that there exists strong seasonality among the three variables with spatial heterogeneity along the Korean South Coast (KSC). In specific, SST was in phase with Chl-a, but out of phase with TSS by six months. A strong inversed spectral power with six-month phase-lag was found between Chl-a and TSS. This could be attributed to different dynamics and environmental settings. For example, Chl-a concentration seemed to have strong positive correlation with SST indicating typical seasonality of marine biogeochemical processes such as primary production; while a strong negative correlation between TSS and SST might have been influenced by changes in physical oceanographic processes, such as stratification and monsoonal wind-driven vertical mixing. In addition, the strong east-west heterogeneity of Chl-a suggests that the marine coastal environments are predominantly governed by distinct local hydrological conditions and human activities associated with land cover and land use, while the east-west spatial pattern revealed in TSS timeseries was associated with the gradient of tidal forcings and topographical changes keeping tidally induced resuspension low eastward.


Asunto(s)
Clorofila , Indicadores de Calidad de la Atención de Salud , Humanos , Clorofila A , Clorofila/análisis , Calidad del Agua , Estaciones del Año , República de Corea , Monitoreo del Ambiente/métodos
7.
BMC Neurol ; 23(1): 175, 2023 Apr 28.
Artículo en Inglés | MEDLINE | ID: mdl-37118674

RESUMEN

BACKGROUND: Cerebral venous and sinus thrombosis (CVST) can cause increased intracranial pressure, often leading to papilledema. In this study, we investigated the association between papilledema and venous stasis on susceptibility weighted imaging (SWI) in CVST. METHODS: Patients with CVST between 2008 and 2020 were reviewed. Patients without fundoscopic examination or SWI were excluded in this study. Venous stasis was evaluated and scored for each cerebral hemisphere: each hemisphere was divided into 5 regions according to the venous drainage territories (superior sagittal sinus, Sylvian veins, transverse sinus and vein of Labbé, deep cerebral veins, and medullary veins) and 1 point was added if venous prominence was confirmed in one territory on SWI. The venous stasis score on SWI between cerebral hemispheres with and without papilledema was compared. RESULTS: Eight of 19 patients with CVST were excluded because of the absence of fundoscopic examination or SWI. Eleven patients (26.5 ± 2.1 years) were included in this study. Papilledema was identified in 6 patients: bilateral papilledema in 4 patients and unilateral papilledema in 2 patients. The venous stasis score on SWI was significantly higher (P = 0.013) in the hemispheres with papilledema (median, 4.0; 95% CI, 3.038-4.562) than in the hemispheres without papilledema (median, 2.5; 95% CI, 0.695-2.805). CONCLUSIONS: This study shows that higher score of venous stasis on SWI is associated with papilledema. Therefore, the venous stasis on SWI may be an imaging surrogate marker of increased intracranial pressure in patients with CVST.


Asunto(s)
Venas Cerebrales , Hipertensión Intracraneal , Papiledema , Trombosis de los Senos Intracraneales , Humanos , Venas Cerebrales/diagnóstico por imagen , Papiledema/diagnóstico por imagen , Papiledema/etiología , Trombosis de los Senos Intracraneales/complicaciones , Trombosis de los Senos Intracraneales/diagnóstico por imagen , Imagen por Resonancia Magnética , Hipertensión Intracraneal/complicaciones
8.
J Stroke ; 25(1): 141-150, 2023 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-36746384

RESUMEN

BACKGROUND AND PURPOSE: We investigated the impact of comorbidity burden on troponin elevation, with separate consideration of neurological conditions, in patients with acute ischemic stroke (AIS). METHODS: This prospective, observational cohort study consecutively enrolled patients with AIS for 2 years. Serum cardiac troponin I was repeatedly measured, and disease-related biomarkers were collected for diagnosis of preassigned comorbidities, including atrial fibrillation (AF), ischemic heart disease (IHD), myocardial hypertrophy (MH), heart failure (HF), renal insufficiency (RI), and active cancer. The severity of neurological deficits and insular cortical ischemic lesions were assessed as neurological conditions. Adjusted associations between these factors and troponin elevation were determined using a multivariate ordinal logistic regression model and area under the receiver operating characteristic curve (AUC). Cox proportional hazards model was used to determine the prognostic significance of comorbidity beyond neurological conditions. RESULTS: Among 1,092 patients (66.5±12.4 years, 63.3% male), 145 (13.3%) and 335 (30.7%) had elevated (≥0.040 ng/mL) and minimally-elevated (0.040-0.010 ng/mL) troponin, respectively. In the adjusted analysis, AF, MH, HF, RI, active cancer, and neurological deficits were associated with troponin elevation. The multivariate model with six comorbidities and two neurological conditions exhibited an AUC of 0.729 (95% confidence interval [CI], 0.698-0.759). In Cox regression, AF, IHD, and HF were associated with adverse cardio-cerebrovascular events, whereas HF and active cancer were associated with mortality. CONCLUSION: Troponin elevation in patients with AIS can be explained by the burden of comorbidities in combination with neurological status, which explains the prognostic significance of troponin assay.

9.
Interv Neuroradiol ; : 15910199221143259, 2022 Dec 15.
Artículo en Inglés | MEDLINE | ID: mdl-36523192

RESUMEN

OBJECTIVES: The long-term durability of carotid artery stenting (CAS) may be determined by various factors; however, residual stenosis is a known risk factor for in-stent restenosis. The authors of this article utilized cone-beam computed tomography (CBCT) in angiosuite to investigate plaque features affecting the character and quality of stent expansion after CAS. METHODS: Forty-two CAS cases with both pre- and post-CAS CBCT evaluations were included in this retrospective analysis. Five features derived from pre-CAS images were tested: (1) eccentricity, (2) overballoon, (3) maximum plaque thickness, (4) calcification barrier, and (5) stenotic degree. For post-CAS CBCT, stent configuration was assessed if the stent was expanded and oval or round in shape as well as outward or inward in orientation. Variables were tested if they were associated with oval expansion, outward expansion, and 20% residual stenosis after CAS. RESULTS: Oval or outward expansion is directly related to residual stenosis. The oval expansion was associated with maximum plaque thickness, and outward expansion was associated with the presence of a calcification barrier. Variables related to > 20% residual stenosis were the maximum plaque thickness, calcification barrier, and pre-CAS stenotic degree. CONCLUSIONS: CBCT for carotid stenosis may provide valuable information about plaque features, especially calcification features that may interfere with the angioplasty effect, as well as the characteristics and quality of stent expansion. Residual stenosis > 20% was associated with calcification barrier, maximum plaque thickness, and pre-CAS stenotic degree.

10.
Materials (Basel) ; 15(15)2022 Jul 25.
Artículo en Inglés | MEDLINE | ID: mdl-35897577

RESUMEN

The purpose of this randomized controlled clinical trial was to assess the short-term clinical effectiveness of sealer-based root canal obturation using calcium-silicate-based sealer (CSBS) and epoxy-resin-based sealer (ERBS). A total of eighty patients (eighty teeth) were enrolled and seventy-two patients (seventy-two teeth) were randomly assigned into four different sealer groups: AH Plus (AH, Dentsply Sirona), ADseal (AD, Meta Biomed), CeraSeal (CS, Meta Biomed), or EndoSeal TCS (ES, Maruchi). At the first visit, root canal treatment was performed using ProTaper. Next, the NiTi file system and passive ultrasonic irritation was applied with 2.5% NaOCl. At the second visit, the teeth were obturated with a sealer-based obturation technique using the assigned sealer. The quality of filling obturation was evaluated with postoperative radiographs in terms of the presence of voids and sealer extrusion. The patients were recalled at 1-week, 1-month, and 3-month intervals, and pain levels were measured using visual analog scales (VAS), and clinical examination performed with percussion and palpation. Radiographs were also taken. The results were statistically compared by using the χ2 test or Fisher exact test. Among the 80 teeth included, 72 teeth received allocated intervention and 71 teeth were included in the analysis (98.6% recall). There was no significant difference among the sealers in void and sealer extrusion (p > 0.05). Postoperative pain was not indicated prominently regardless of the type of sealer. For a 3-month follow-up period, all cases were maintained successfully except for one case from AD. According to the findings, there was no significant difference between CSBS and ERBS in terms of postoperative pain or the healing process, and the variation in filling quality appears to be linked to the properties of each product.

11.
Aust Endod J ; 47(3): 512-519, 2021 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-33894082

RESUMEN

The purpose of this study was to compare the physical properties and cytocompatibility of contemporary calcium silicate-based sealers. Four calcium silicate-based sealers (BrightEndo MTA sealer, CeraSeal, EndoSeal TCS and One-Fil) were compared to an epoxy resin-based sealer (AH Plus). Flow, setting time, radiopacity and dimensional change were evaluated according to ISO 6876 standards. Cytotoxicity on human periodontal ligament fibroblast (hPDLF) cells was compared for biological properties using MTT assay. The surface of the sealer was analysed using scanning electron microscopy to evaluate cell attachment. Flow and radiopacity of all sealers met ISO standards, while setting time and dimensional stability did not meet the ISO standards. Calcium silicate-based sealers showed favourable cytocompatibility, and hPDLF cells were well attached to the calcium silicate-based sealers. Calcium silicate-based sealers have clinically acceptable flow and radiopacity, and cytocompatibility. However, these sealers had longer setting time and higher dimensional change than those required by ISO 6876.


Asunto(s)
Proyectos de Investigación , Compuestos de Calcio , Humanos , Silicatos
12.
Sensors (Basel) ; 21(3)2021 Jan 22.
Artículo en Inglés | MEDLINE | ID: mdl-33499356

RESUMEN

Many IoT applications require a mechanism to disseminate commands and collect responses over a wireless network in order to control and collect data from multiple embedded devices. However, severe collisions may occur if a large number of nodes attempt to respond simultaneously and promptly, not only among the responses, but also with the dissemination of commands. This is because low-power wireless network protocols for dissemination and collection have been designed separately. Tuning the parameters of one side of the protocol has clear trade-off between reliability and latency. To address this challenge, we propose SCoRe, an on-demand scheme for joint scheduling of command and responses on multihop low-power wireless networks to improve both reliability and latency simultaneously at runtime. SCoRe gathers the amount of time required by network nodes for dissemination and collection, and allocates relative timeslots to each node recursively over multihop on-demand when (and only when) disseminating a command. While doing so, information exchange occurs only between local neighbor nodes without a need for global routing table nor time synchronization. We implement SCoRe on a low-power embedded platform, and compare with well-known dissemination and collection schemes through both simulations and testbed experiments on 30 devices. Our evaluation results show that SCoRe can improve both latency and reliability without tuning the parameters for one metric, while the legacy schemes require careful parameter selection to match only one side of SCoRe, never both.

13.
Nat Commun ; 12(1): 26, 2021 01 04.
Artículo en Inglés | MEDLINE | ID: mdl-33397915

RESUMEN

Mitochondrial oxidation-induced cell death, a physiological process triggered by various cancer therapeutics to induce oxidative stress on tumours, has been challenging to investigate owing to the difficulties in generating mitochondria-specific oxidative stress and monitoring mitochondrial responses simultaneously. Accordingly, to the best of our knowledge, the relationship between mitochondrial protein oxidation via oxidative stress and the subsequent cell death-related biological phenomena has not been defined. Here, we developed a multifunctional iridium(III) photosensitiser, Ir-OA, capable of inducing substantial mitochondrial oxidative stress and monitoring the corresponding change in viscosity, polarity, and morphology. Photoactivation of Ir-OA triggers chemical modifications in mitochondrial protein-crosslinking and oxidation (i.e., oxidative phosphorylation complexes and channel and translocase proteins), leading to microenvironment changes, such as increased microviscosity and depolarisation. These changes are strongly related to cell death by inducing mitochondrial swelling with excessive fission and fusion. We suggest a potential mechanism from mitochondrial oxidative stress to cell death based on proteomic analyses and phenomenological observations.


Asunto(s)
Iridio/farmacología , Mitocondrias/metabolismo , Fármacos Fotosensibilizantes/farmacología , Muerte Celular/efectos de los fármacos , Reactivos de Enlaces Cruzados/química , Transferencia de Energía , Células HEK293 , Células HeLa , Humanos , Potencial de la Membrana Mitocondrial/efectos de los fármacos , Mitocondrias/efectos de los fármacos , Proteínas Mitocondriales/metabolismo , Oxidación-Reducción/efectos de los fármacos , Proteoma/metabolismo , Especies Reactivas de Oxígeno/metabolismo , Viscosidad
14.
Front Neurol ; 12: 759822, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34987464

RESUMEN

Background and Purpose: The aim of this study was to determine the relationship between the heart rate-corrected QT (QTc) interval and the risk of incident long-term mortality in patients with acute ischemic stroke (AIS), considering the impact of sex differences on clinical characteristics, outcomes, and QTc intervals. Methods: We analyzed prospectively registered data included patients with AIS who visited the emergency room within 24 h of stroke onset and underwent routine cardiac testing, such as measurements of cardiac enzymes and 12-lead ECG. QTc interval was corrected for heart rate using Fridericia's formula and was stratified by sex-specific quartiles. Cox proportional hazards models were used to examine the association between baseline QTc interval and incident all-cause death. Results: A total of 1,668 patients with 1,018 (61.0%) men and mean age 66.0 ± 12.4 years were deemed eligible. Based on the categorized quartiles of the QTc interval, cardiovascular risk profile, and stroke severity increased with prolonged QTc interval, and the risk of long-term mortality increased over a median follow-up of 33 months. Cox proportional hazard model analysis showed that the highest quartile of QTc interval (≥479 msec in men and ≥498 msec in women; hazard ratio [HR]: 1.49, 95% confidence interval [CI]: 1.07-2.08) was associated with all-cause death. Furthermore, dichotomized QTc interval prolongation, defined by the highest septile of the QTc interval (≥501 ms in men and ≥517 m in women: HR: 1.33, 95% CI: 1.00-1.80) was significantly associated with all-cause mortality after adjusting for all clinically relevant variables, such as stroke severity. Conclusions: Prolonged QTc interval was associated with increased risk of long-term mortality, in parallel with the increasing trend of prevalence of cardiovascular risk profiles and stroke severity, across sex differences in AIS patients.

15.
Sleep Med ; 76: 26-32, 2020 12.
Artículo en Inglés | MEDLINE | ID: mdl-33069999

RESUMEN

OBJECTIVES: Short sleep duration has been known to be related to metabolic syndrome (MetS) . The aim of this study was to investigate the beneficial effects of weekend catch-up sleep (WCUS) on MetS in the Korean middle-aged population. METHODS: For this cross-sectional study, 1,812 participants aged 35-60 years were selected from the 2016-2018 Korean National Health and Nutrition Examination Survey (mean age 46.94 years, 49% male). Short sleep duration was defined as <6hrs on weekdays, and participants were divided into two groups: WCUS group and no weekend catch-up sleep group. Multiple logistic regression was performed to determine the association between WCUS and MetS prevalence. The covariates included age, sex, education, income, occupation, smoking, alcohol consumption, and physical activity. RESULTS: WCUS was significantly associated with lower MetS prevalence in the unadjusted model and in the model adjusted for socioeconomic and health behavior factors. CONCLUSION: These results support the beneficial effects of WCUS on lowering the risk of MetS among middle-aged chronic short sleepers.


Asunto(s)
Síndrome Metabólico , Sueño , Adulto , Estudios Transversales , Femenino , Humanos , Masculino , Síndrome Metabólico/epidemiología , Persona de Mediana Edad , Encuestas Nutricionales , Prevalencia , República de Corea/epidemiología , Factores de Tiempo
16.
Sensors (Basel) ; 20(18)2020 Sep 17.
Artículo en Inglés | MEDLINE | ID: mdl-32957672

RESUMEN

We present two algorithms for aligning two colored point clouds. The two algorithms are designed to minimize a probabilistic cost based on the color-supported soft matching of points in a point cloud to their K-closest points in the other point cloud. The first algorithm, like prior iterative closest point algorithms, refines the pose parameters to minimize the cost. Assuming that the point clouds are obtained from RGB-depth images, our second algorithm regards the measured depth values as variables and minimizes the cost to obtain refined depth values. Experiments with our synthetic dataset show that our pose refinement algorithm gives better results compared to the existing algorithms. Our depth refinement algorithm is shown to achieve more accurate alignments from the outputs of the pose refinement step. Our algorithms are applied to a real-world dataset, providing accurate and visually improved results.

17.
Neuroimage ; 220: 117106, 2020 10 15.
Artículo en Inglés | MEDLINE | ID: mdl-32615253

RESUMEN

There is an urgent need for better detection and understanding of vascular abnormalities at the micro-level, where critical vascular nourishment and cellular metabolic changes occur. This is especially the case for structures such as the midbrain where both the feeding and draining vessels are quite small. Being able to monitor and diagnose vascular changes earlier will aid in better understanding the etiology of the disease and in the development of therapeutics. In this work, thirteen healthy volunteers were scanned with a dual echo susceptibility weighted imaging (SWI) sequence, with a resolution of 0.22 â€‹× â€‹0.44 â€‹× â€‹1 â€‹mm3 at 3T. Ultra-small superparamagnetic iron oxides (USPIO) were used to induce an increase in susceptibility in both arteries and veins. Although the increased vascular susceptibility enhances the visibility of small subvoxel vessels, the accompanying strong signal loss of the large vessels deteriorates the local tissue contrast. To overcome this problem, the SWI data were acquired at different time points during a gradual administration (final concentration â€‹= â€‹4 â€‹mg/kg) of the USPIO agent, Ferumoxytol, and the data was processed to combine the SWI data dynamically, in order to see through these blooming artifacts. The major vessels and their tributaries (such as the collicular artery, peduncular artery, peduncular vein and the lateral mesencephalic vein) were identified on the combined SWI data using arterio-venous maps. Dynamically combined SWI data was then compared with previous histological work to validate that this protocol was able to detect small vessels on the order of 50 â€‹µm-100 â€‹µm. A complex division-based phase unwrapping was also employed to improve the quality of quantitative susceptibility maps by reducing the artifacts due to aliased voxels at the vessel boundaries. The smallest detectable vessel size was then evaluated by revisiting numerical simulations, using estimated true susceptibilities for the basal vein and the posterior cerebral artery in the presence of Ferumoxytol. These simulations suggest that vessels as small as 50 â€‹µm should be visible with the maximum dose of 4 â€‹mg/kg.


Asunto(s)
Arterias/diagnóstico por imagen , Angiografía por Resonancia Magnética/métodos , Imagen por Resonancia Magnética/métodos , Mesencéfalo/diagnóstico por imagen , Venas/diagnóstico por imagen , Adulto , Femenino , Humanos , Procesamiento de Imagen Asistido por Computador , Masculino , Mesencéfalo/irrigación sanguínea , Persona de Mediana Edad , Adulto Joven
18.
Sci Rep ; 10(1): 8566, 2020 05 22.
Artículo en Inglés | MEDLINE | ID: mdl-32444685

RESUMEN

The aim of this study was to define the location of the accessory infraorbital foramen (AIOF) with reference to accessible external landmarks in order to facilitate orbital and oculoplastic surgical procedures in the maxillofacial region. Forty-four hemifaces from 25 cadavers were dissected. The lateral canthus, subnasal point, and lacrimal caruncle were used as anatomic reference points. The AIOF was observed in 8 of the 44 hemifaces (18.2%) and was situated at a mean distance of 7.2 mm superomedial to the IOF. The horizontal distance from the lacrimal caruncle to the AIOF was 0.3 mm. In all cases the AIOF was situated at a point that was no more than 8 mm from the intersection point of a vertical line passing through the lacrimal caruncle and an oblique line joining the lateral canthus and the subnasal point. Surgeons anesthetizing or performing surgical procedures in the maxillofacial region should be aware of the frequency of the AIOF (18.2%) and its location (on the superomedial side of the IOF). We propose that injecting at the intersection point of a vertical line passing through the lacrimal caruncle and an oblique line joining the lateral canthus and the subnasal point would successfully block the accessory branch of the infraorbital nerve. Likewise, surgeons operating in this region should be aware of the location of the AIOF in order to avoid inadvertent iatrogenic injury to a duplicated infraorbital nerve.


Asunto(s)
Puntos Anatómicos de Referencia , Maxilar/anatomía & histología , Órbita/anatomía & histología , Adulto , Anciano , Anciano de 80 o más Años , Cadáver , Femenino , Humanos , Masculino , Persona de Mediana Edad , Estándares de Referencia
19.
J Nanosci Nanotechnol ; 20(9): 5618-5624, 2020 09 01.
Artículo en Inglés | MEDLINE | ID: mdl-32331146

RESUMEN

Ti alloy for implant materials is not good biocompatibility between metal implants and natural bone without surface modification. In order to improve the bone attachment ability, implant surface modification is required, and corrosion resistance is also important when a surface modified implant is inserted into the body. In this study, corrosion behaviors of anodic oxide film formed on Ti-6Al-4V alloy with concentration of Mn and Zn ions were studied using various experimental techniques. Ti-6Al-4V ELI disk were used as the substrate for PEO treatment. The sample was used a anodic electrode and PEO treatment was carried out by varying the content of each of the electrolytic solutions containing Zn, Mn, Si, Ca and P, using a Pt bar as a cathodic electrode. Pulsed DC power was used at 280 V for 3 min. For the corrosion behaviors of the specimens, the potentiodynamic polarization and AC impedance test were carried out in 0.9% NaCl solution. From the result of experiments, as Zn ion content increases, the number of pores and the pore size increase. As the Mn ion increases, the number of pores decreases, while the pore size increases. As the ions of Mn increase, the corrosion potential decreases. As Zn ion content increased, the polarization resistance increased.

20.
Clin Endosc ; 52(4): 328-333, 2019 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-30786704

RESUMEN

Capsule endoscopy (CE) is a preferred diagnostic method for analyzing small bowel diseases. However, capsule endoscopes capture a sparse number of images because of their mechanical limitations. Post-procedural management using computational methods can enhance image quality. Additional information, including depth, can be obtained by using recently developed computer vision techniques. It is possible to measure the size of lesions and track the trajectory of capsule endoscopes using the computer vision technology, without requiring additional equipment. Moreover, the computational analysis of CE images can help detect lesions more accurately within a shorter time. Newly introduced deep leaning-based methods have shown more remarkable results over traditional computerized approaches. A large-scale standard dataset should be prepared to develop an optimal algorithms for improving the diagnostic yield of CE. The close collaboration between information technology and medical professionals is needed.

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