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1.
Bioinformatics ; 40(1)2024 01 02.
Artículo en Inglés | MEDLINE | ID: mdl-38152895

RESUMEN

MOTIVATION: Single cell segmentation is critical in the processing of spatial omics data to accurately perform cell type identification and analyze spatial expression patterns. Segmentation methods often rely on semi-supervised annotation or labeled training data which are highly dependent on user expertise. To ensure the quality of segmentation, current evaluation strategies quantify accuracy by assessing cellular masks or through iterative inspection by pathologists. While these strategies each address either the statistical or biological aspects of segmentation, there lacks a unified approach to evaluating segmentation accuracy. RESULTS: In this article, we present ESQmodel, a Bayesian probabilistic method to evaluate single cell segmentation using expression data. By using the extracted cellular data from segmentation and a prior belief of cellular composition as input, ESQmodel computes per cell entropy to assess segmentation quality by how consistent cellular expression profiles match with cell type expectations. AVAILABILITY AND IMPLEMENTATION: Source code is available on Github at: https://github.com/Roth-Lab/ESQmodel.


Asunto(s)
Programas Informáticos , Células Secretoras de Somatostatina , Teorema de Bayes , Entropía , Procesamiento de Imagen Asistido por Computador
2.
Nano Lett ; 23(15): 6799-6806, 2023 Aug 09.
Artículo en Inglés | MEDLINE | ID: mdl-37486984

RESUMEN

Near the magic angle, strong correlations drive many intriguing phases in twisted bilayer graphene (tBG) including unconventional superconductivity and chern insulation. Whether correlations can tune symmetry breaking phases in tBG at intermediate (≳ 2°) twist angles remains an open fundamental question. Here, using ARPES, we study the effects of many-body interactions and displacement field on the band structure of tBG devices at an intermediate (3°) twist angle. We observe a layer- and doping-dependent renormalization of bands at the K points that is qualitatively consistent with moiré models of the Hartree-Fock interaction. We provide evidence of correlation-enhanced inversion symmetry-breaking, manifested by gaps at the Dirac points that are tunable with doping. These results suggest that electronic interactions play a significant role in the physics of tBG even at intermediate twist angles and present a new pathway toward engineering band structure and symmetry-breaking phases in moiré heterostructures.

3.
Anal Chem ; 95(16): 6732-6739, 2023 04 25.
Artículo en Inglés | MEDLINE | ID: mdl-37040477

RESUMEN

Approaches for the characterization of proteins/peptides in single cells of formaldehyde-fixed (FF) tissues via mass spectrometry (MS) are still under development. The lack of a general method for selectively eliminating formaldehyde-induced crosslinking is a major challenge. A workflow is shown for the high-throughput peptide profiling of single cells isolated from FF tissues, here the rodent pancreas, which possesses multiple peptide hormones from the islets of Langerhans. The heat treatment is enhanced by a collagen-selective multistep thermal process assisting efficient isolation of islets from the FF pancreas and, subsequently, their dissociation into single islet cells. Hydroxylamine-based chemical decrosslinking helped restore intact peptide signals from individual isolated cells. Subsequently, an acetone/glycerol-assisted cell dispersion was optimized for spatially resolved cell deposition onto glass slides, while a glycerol solution maintained the hydrated state of the cells. This sample preparation procedure allowed peptide profiling in FF single cells by fluorescence-guided matrix-assisted laser desorption ionization MS. Here, 2594 single islet cells were analyzed and 28 peptides were detected, including insulin C-peptides and glucagon. T-distributed stochastic neighbor embedding (t-SNE) data visualization demonstrated that cells cluster based on cell-specific pancreatic peptide hormones. This workflow expands the sample availability for single-cell MS characterization to a wide range of formaldehyde-treated tissue specimens stored in biobanks.


Asunto(s)
Glicerol , Páncreas , Ratas , Animales , Páncreas/química , Péptidos/análisis , Espectrometría de Masa por Láser de Matriz Asistida de Ionización Desorción/métodos , Glucagón , Formaldehído
4.
Immunol Invest ; 52(6): 749-766, 2023 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-37403798

RESUMEN

BACKGROUND: Tumor innervation has been shown to be utilized by some solid cancers to support tumor initiation, growth, progression, and metastasis, as well as confer resistance to immune checkpoint blockade through suppression of antitumor immunologic responses. Since botulinum neurotoxin type A1 (BoNT/A1) blocks neuronal cholinergic signaling, its potential use as an anticancer drug in combination with anti-PD-1 therapy was investigated in four different syngeneic mouse tumor models. METHODS: Mice implanted with breast (4T1), lung (LLC1), colon (MC38), and melanoma (B16-F10) tumors were administered a single intratumoral injection of 15 U/kg BoNT/A1, repeated intraperitoneal injections of 5 mg/kg anti-PD-1 (RMP1-14), or both. RESULTS: Compared to the single-agent treatments, anti-PD-1 and BoNT/A1 combination treatment elicited significant reduction in tumor growth among B16-F10 and MC38 tumor-bearing mice. The combination treatment also lowered serum exosome levels in these mice compared to the placebo control group. In the B16-F10 syngeneic mouse tumor model, anti-PD-1 + BoNT/A1 combination treatment lowered the proportion of MDSCs, negated the increased proportion of Treg cells, and elicited a higher number of tumor-infiltrating CD4+ and CD8+ T lymphocytes into the tumor microenvironment compared to anti-PD-1 treatment alone. CONCLUSION: Our findings demonstrate the synergistic antitumor effects of BoNT/A1 and PD-1 checkpoint blockade in mouse tumor models of melanoma and colon carcinoma. These findings provide some evidence on the potential application of BoNT/A1 as an anticancer drug in combination with immune checkpoint blockade and should be further explored.


Asunto(s)
Antineoplásicos , Toxinas Botulínicas , Melanoma , Animales , Ratones , Receptor de Muerte Celular Programada 1 , Inhibidores de Puntos de Control Inmunológico/farmacología , Inhibidores de Puntos de Control Inmunológico/uso terapéutico , Línea Celular Tumoral , Antineoplásicos/farmacología , Toxinas Botulínicas/farmacología , Colon , Microambiente Tumoral , Linfocitos T CD8-positivos
5.
BMC Surg ; 23(1): 368, 2023 Dec 08.
Artículo en Inglés | MEDLINE | ID: mdl-38066440

RESUMEN

BACKGROUND: Textbook outcomes is a composite quality assurance tool assessing the ideal perioperative and postoperative course as a unified measure. Currently, its definition and application in the context of oesophagectomy in Australia is unknown. The aim of this study was to assess the textbook outcomes after oesophagectomy in a single referral centre of Australia and investigate the association between textbook outcomes and patient, tumour, and treatment characteristics. METHODS: An observational study was retrospectively performed on patients undergoing open, laparoscopic, or hybrid oesophagectomy between January 2010 and December 2019 in a single cancer referral centre. A textbook outcome was defined as the fulfillment of 10 criteria: R0 resection, retrieval of at least 15 lymph nodes, no intraoperative complications, no postoperative complications greater than Clavien-Dindo grade III, no anastomotic leak, no readmission to the ICU, no hospital stay beyond 21 days, no mortality within 90 days, no readmission related to the surgical procedure within 30 days from admission and no reintervention related to the surgical procedure. The proportion of patients who met each criterion for textbook outcome was calculated and compared. Selected patient-related parameters (age, gender, BMI, ASA score, CCI score), tumour-related factors (tumour location, tumour histology, AJCC clinical T and N stage and treatment-related factor [neoadjuvant chemotherapy and surgical approach]) were assessed. Disease recurrence and one year survival were also evaluated. RESULTS: 110 patients who underwent oesophagectomy were included. The overall textbook outcome rate was 24%. The difference in rates across the years was not statistically significant. The most achieved textbook outcome parameters were 'no mortality in 90 days' (96%) and 'R0 resection' (89%). The least frequently met textbook outcome parameter was 'no severe postoperative complications' (58%), followed by 'no hospital stays over 21 days' (61%). No significant association was found between patient, tumour and treatment characteristics and the rate of textbook outcome. Tumour recurrence rate and overall long term survival was similar between textbook outcome and non-textbook outcome groups. Patients with R0 resection, no intraoperative complication and a hospital stay less than 21 days had reduced mortality rates. CONCLUSIONS: Textbook outcome is a clinically relevant indicator and was achieved in 24% of patients. Severe complications and a prolonged hospital stay were the key criteria that limited the achievement of a textbook outcome. These findings provide meticulous evaluation of oesophagectomy perioperative care and provide a direction for the utilisation of this concept in identifying and improving surgical and oncological care across multiple healthcare levels.


Asunto(s)
Neoplasias Esofágicas , Esofagectomía , Humanos , Estudios Retrospectivos , Esofagectomía/efectos adversos , Recurrencia Local de Neoplasia/cirugía , Complicaciones Posoperatorias/etiología , Fuga Anastomótica/etiología , Complicaciones Intraoperatorias/etiología , Resultado del Tratamiento
6.
BMC Surg ; 23(1): 335, 2023 Nov 04.
Artículo en Inglés | MEDLINE | ID: mdl-37924061

RESUMEN

BACKGROUND: Antiemetic and analgesic oral premedications are frequently prescribed preoperatively to enhance recovery after laparoscopic sleeve gastrectomy. However, it is unknown whether these medications transit beyond the stomach or if they remain in the sleeve resection specimen, thereby negating their pharmacological effects. METHODS: A retrospective cohort study was performed on patients undergoing laparoscopic sleeve gastrectomy and receiving oral premedication (slow-release tapentadol and netupitant/palonosetron) as part of enhanced recovery after bariatric surgery program. Patients were stratified into the Transit group (premedication absent in the resection specimen) and Failure-to-Transit group (premedication present in the resection specimen). Age, sex, body mass index, and presence of diabetes were compared amongst the groups. The premedication lead time (time between premedications' administration and gastric specimen resection), and the premedication presence or absence in the specimen was evaluated. RESULTS: One hundred consecutive patients were included in the analysis. Ninety-nine patients (99%) were morbidly obese, and 17 patients (17%) had Type 2 diabetes mellitus. One hundred patients (100%) received tapentadol and 89 patients (89%) received netupitant/palonosetron. One or more tablets were discovered in the resected specimens of 38 patients (38%). No statistically significant differences were observed between the groups regarding age, sex, diabetes, or body mass index. The median (Q1‒Q3) premedication lead time was 80 min (57.8‒140.0) in the Failure-to-Transit group and 119.5 min (85.0‒171.3) in the Transit group; P = 0.006. The lead time required to expect complete absorption in 80% of patients was 232 min (95%CI:180‒310). CONCLUSIONS: Preoperative oral analgesia and antiemetics did not transit beyond the stomach in 38% of patients undergoing laparoscopic sleeve gastrectomy. When given orally in combination, tapentadol and netupitant/palonosetron should be administered at least 4 h before surgery to ensure transition beyond the stomach. Future enhanced recovery after bariatric surgery guidelines may benefit from the standardization of premedication lead times to facilitate increased absorption. TRIAL REGISTRATION: Australian and New Zealand Clinical Trials Registry; number ACTRN12623000187640; retrospective registered on 22/02/2023.


Asunto(s)
Diabetes Mellitus Tipo 2 , Laparoscopía , Obesidad Mórbida , Humanos , Australia , Diabetes Mellitus Tipo 2/cirugía , Gastrectomía , Obesidad Mórbida/cirugía , Palonosetrón , Estudios Retrospectivos , Estómago , Tapentadol , Resultado del Tratamiento , Masculino , Femenino
7.
BMC Anesthesiol ; 22(1): 69, 2022 03 11.
Artículo en Inglés | MEDLINE | ID: mdl-35277122

RESUMEN

BACKGROUND: Intraoperative hypotension (IOH) during non-cardiac surgery is common and associated with major adverse kidney, neurological and cardiac events and even death. Given that IOH is a modifiable risk factor for the mitigation of postoperative complications, it is imperative to generate a precise definition for IOH to facilitate strategies for avoiding or treating its occurrence. Moreover, a universal and consensus definition of IOH may also facilitate the application of novel and emerging therapeutic interventions in treating IOH. We conducted a review to systematically record the reported definitions of intraoperative hypotension in adults undergoing non-cardiac surgery under general anaesthesia. METHODS: In accordance with Cochrane guidelines, we searched three online databases (OVID [Medline], Embase and Cochrane Library) for all studies published from 1 January 2000 to 6 September 2020. We evaluated the number of studies that reported the absolute or relative threshold values for defining blood pressure. Secondary aims included evaluation of the threshold values for defining IOH, the methodology for accounting for the severity of hypotension, whether the type of surgical procedure influenced the definition of IOH, and whether a study whose definition of IOH aligned with the Perioperative Quality Initiative-3 workgroup (POQI) consensus statement for defining was more likely to be associated with determining an adverse postoperative outcome. RESULTS: A total of 318 studies were included in the final qualitative synthesis. Most studies (n = 249; 78.3%) used an absolute threshold to define hypotension; 150 (60.5%) reported SBP, 117 (47.2%) reported MAP, and 12 (4.8%) reported diastolic blood pressure (DBP). 126 (39.6%) used a relative threshold to define hypotension. Of the included studies, 153 (48.1%) did not include any duration variable in their definition of hypotension. Among the selected 318 studies 148 (46.5%) studies defined IOH according to the POQI statement. When studies used a "relative blood pressure change" to define IOH, there was a weaker association in detecting adverse postoperative outcomes compared to studies who reported "absolute blood pressure change" (χ2(2) = 10.508, P = 0.005, Cramér's V = 0.182). When studies used the POQI statement definition of hypotension or defined IOH by values higher than the POQI statement definition there were statistical differences observed between IOH and adverse postoperative outcomes (χ2(1) = 6.581, P = 0.037, Cramér's V = 0.144). When both the duration of IOH or the numbers of hypotensive epochs were evaluated, we observed a significantly stronger relationship between the definition of IOH use the development of adverse postoperative outcomes. (χ2(1) = 4.860, P = 0.027, Cramér's V = 0.124). CONCLUSIONS: Most studies defined IOH by absolute or relative changes from baseline values. There are substantial inconsistencies in how IOH was reported. Further, definitions differed across different surgical specialities. Our findings further suggest that IOH should be defined using the absolute values stated in the POQI statement i.e., MAP < 60-70 mmHg or SBP < 100 mmHg. Finally, the number of hypotensive epochs or time-weighted duration of IOH should also be reported.


Asunto(s)
Hipotensión , Complicaciones Intraoperatorias , Adulto , Anestesia General/efectos adversos , Estudios de Cohortes , Humanos , Hipotensión/complicaciones , Hipotensión/etiología , Complicaciones Intraoperatorias/epidemiología , Complicaciones Posoperatorias/diagnóstico , Complicaciones Posoperatorias/epidemiología , Complicaciones Posoperatorias/etiología
8.
Sensors (Basel) ; 22(5)2022 Mar 03.
Artículo en Inglés | MEDLINE | ID: mdl-35271133

RESUMEN

In this paper, I propose a bird eye view image detection method for parking areas and collision risk areas at the same time in parking situations. Deep learning algorithms using area detection and semantic segmentation were used. The main architecture of the method described in this paper is based on a harmonic densely connected network and a cross-stage partial network. The dataset used for training was calibrated to four 190° wide-angle cameras to generate around view monitor (AVM) images based on the Chungbuk National University parking lot, and an experiment was performed based on this dataset. In the experimental results, the available parking area was visualized by detecting the parking line, parking area, and available driving area in the AVM images. Furthermore, the undetected area in the semantic segmentation as a collision risk area was visualized in order to obtain the results. According to the proposed attention CSPHarDNet model, the experimental results were 81.89% mIoU and 18.36 FPS in a NVIDIA Xavier environment. The results of this experiment demonstrated that algorithms can be used in real time in a parking situation and have better performance results compared to the conventional HarDNet.


Asunto(s)
Conducción de Automóvil , Aprendizaje Profundo , Algoritmos , Humanos , Redes Neurales de la Computación
9.
J Anesth ; 36(6): 723-730, 2022 12.
Artículo en Inglés | MEDLINE | ID: mdl-36161534

RESUMEN

PURPOSE: The hematocrit-to-whole blood viscosity ratio (Hct/WBV) reflects the blood O2 delivery potential (O2-DP). WBV is variable to the dynamic vascular shear rate (SR), 1-5/s at microcirculation and 300/s at larger vessels. To estimate the impact of hemodilution on the blood O2-DP to the myocardium, we analyzed the hemodilution-induced change of Hct/WBV at SR 5/s (Hct/WBV5) during off-pump coronary bypass (OPCAB) surgery. METHODS: During OPCAB surgery (n = 21), 10% acute normovolemic hemodilution (HD 10%) was applied. Arterial blood samples were taken: one before and two after HD 10%. One of which after HD 10% underwent an additional 33% in vitro hemodilution (reaching 40% hemodilution in total, HD 40%). WBV of all blood samples was determined using a scan-capillary tube viscometer (Hemovister™). The changes of Hct/WBV5 were analyzed as a primary measure of the study and compared with those of Hct/WBV at SR 300/s (Hct/WBV300). RESULTS: Median[IQR] of Hct/WBV5 [3.5 (2.8-4.2)%/cPoise] was significantly increased by HD 10 and HD 40% [3.6 (3.2-4.6)%/cPoise and 4.2 (3.3-5.2)%/cPoise, respectively, all P < 0.001], but the degrees of changes after HD 10 and HD 40% were not different. Median[IQR] of Hct/WBV300 [10.3(8.6‒10.8)%/cPoise] was not changed by HD 10% [10.3(9.1-11.1)%/cPoise], but it was significantly decreased by HD 40% [8.4(7.4‒9.2)%/cPoise, P < 0.001]. CONCLUSION: The increased Hct/WBV5 suggests that 10-40% hemodilution improves the blood O2-DP to the myocardium during OPCAB surgery. The SR-specific discrepancy in Hct/WBV changes advocates using microvascular WBV and Hct/WBV to evaluate the blood O2-DP changes to the myocardium. Further study is warranted to assess the actual changes in myocardial O2 delivery.


Asunto(s)
Hemodilución , Consumo de Oxígeno , Oxígeno , Hematócrito , Miocardio/metabolismo
10.
NMR Biomed ; 34(6): e4481, 2021 06.
Artículo en Inglés | MEDLINE | ID: mdl-33590547

RESUMEN

Increasing evidence suggests that alterations in cerebral microvasculature play a critical role in the pathogenesis of Alzheimer's disease (AD). The objective of this study was to characterize and evaluate the cerebral microvascular architecture of AD transgenic (Tg) mice and compare it with that of non-Tg mice using brain microvascular indices obtained by MRI. Seven non-Tg mice and 10 5xFAD Tg mice were scanned using a 7-T animal MRI system to measure the transverse relaxation rates of R2 and R2* before and after the injection of the monocrystalline iron oxide nanoparticle contrast agent. After calculating ΔR2* and ΔR2, the vessel size index (VSI), mean vessel diameter (mVD), mean vessel density, mean vessel-weighted image (MvWI) and blood volume fraction (BVf) were mapped. Voxel-based analyses and region of interest (ROI)-based analyses were performed to compare the indices of the non-Tg and Tg groups. Voxel comparisons showed that BVf, mVD, VSI and MvWI were greater in the Tg group than in the non-Tg group. Additionally, the ROI-based analysis showed that ΔR2*, BVf, mVD, MvWI and VSI increased in several brain regions of the Tg group compared with those in the non-Tg group. VSI and mVD increased in Tg mice; these findings indicated microvascular disruption in the brain that could be related to damage to the neurovascular unit in AD caused by cerebral amyloid angiopathy.


Asunto(s)
Mapeo Encefálico , Encéfalo/irrigación sanguínea , Microvasos/diagnóstico por imagen , Enfermedad de Alzheimer , Animales , Encéfalo/citología , Modelos Animales de Enfermedad , Imagen por Resonancia Magnética , Ratones Transgénicos
11.
BMC Surg ; 21(1): 31, 2021 Jan 07.
Artículo en Inglés | MEDLINE | ID: mdl-33413263

RESUMEN

BACKGROUND: It is uncertain whether increases in PaCO2 during surgery lead to an increase in plasma potassium concentration and, if so, by how much. Hyperkalaemia may result in cardiac arrhythmias, muscle weakness or paralysis. The key objectives were to determine whether increases in PaCO2 during laparoscopic surgery induce increases in plasma potassium concentrations and, if so, to determine the magnitude of such changes. METHODS: A retrospective observational study of adult patients undergoing laparoscopic abdominal surgery was perfomed. The independent association between increases in PaCO2 and changes in plasma potassium concentration was assessed by performing arterial blood gases within 15 min of induction of anaesthesia and within 15 min of completion of surgery. RESULTS: 289 patients were studied (mean age of 63.2 years; 176 [60.9%] male, and mean body mass index of 29.3 kg/m2). At the completion of the surgery, PaCO2 had increased by 5.18 mmHg (95% CI 4.27 mmHg to 6.09 mmHg) compared to baseline values (P < 0.001) with an associated increase in potassium concentration of 0.25 mmol/L (95% CI 0.20 mmol/L to 0.31 mmol/L, P < 0.001). On multiple regression analysis, PaCO2 changes significantly predicted immediate changes in plasma potassium concentration and could account for 33.1% of the variance (r2 = 0.331, f(3,259) = 38.915, P < 0.001). For each 10 mmHg increment of PaCO2 the plasma potassium concentration increased by 0.18 mmol/L. CONCLUSION: In patients receiving laparoscopic abdominal surgery, there is an increase in PaCO2 at the end of surgery, which is independently associated with an increase in plasma potassium concentration. However, this effect is small and is mostly influenced by intravenous fluid therapy (Plasma-Lyte 148 solution) and the presence of diabetes. Trial registration Retrospectively registered in the Australian New Zealand Clinical Trials Registry (Trial Number: ACTRN12619000716167).


Asunto(s)
Dióxido de Carbono/sangre , Laparoscopía/efectos adversos , Potasio/sangre , Adulto , Anciano , Australia , Femenino , Humanos , Masculino , Persona de Mediana Edad , Estudios Retrospectivos , Resultado del Tratamiento
12.
Sensors (Basel) ; 21(22)2021 Nov 17.
Artículo en Inglés | MEDLINE | ID: mdl-34833698

RESUMEN

Although numerous road segmentation studies have utilized vision data, obtaining robust classification is still challenging due to vision sensor noise and target object deformation. Long-distance images are still problematic because of blur and low resolution, and these features make distinguishing roads from objects difficult. This study utilizes light detection and ranging (LiDAR), which generates information that camera images lack, such as distance, height, and intensity, as a reliable supplement to address this problem. In contrast to conventional approaches, additional domain transformation to a bird's eye view space is executed to obtain long-range data with resolutions comparable to those of short-range data. This study proposes a convolutional neural network architecture that processes data transformed to a bird's eye view plane. The network's pathways are split into two parts to resolve calibration errors in the transformed image and point cloud. The network, which has modules that operate sequentially at various scaled dilated convolution rates, is designed to quickly and accurately handle a wide range of data. Comprehensive empirical studies using the Karlsruhe Institute of Technology and Toyota Technological Institute's (KITTI's) road detection benchmarks demonstrate that this study's approach takes advantage of camera and LiDAR information, achieving robust road detection with short runtimes. Our result ranks 22nd in the KITTI's leaderboard and shows real-time performance.


Asunto(s)
Redes Neurales de la Computación
13.
Sensors (Basel) ; 21(2)2021 Jan 07.
Artículo en Inglés | MEDLINE | ID: mdl-33430443

RESUMEN

We developed an integrated PCR system that performs automated sample preparation and fast polymerase chain reaction (PCR) for application in point-of care (POC) testing. This system is assembled from inexpensive 3D-printing parts, off-the-shelf electronics and motors. Molecular detection requires a series of procedures including sample preparation, amplification, and fluorescence intensity analysis. The system can perform automated DNA sample preparation (extraction, separation and purification) in ≤5 min. The variance of the automated sample preparation was clearly lower than that achieved using manual DNA extraction. Fast thermal ramp cycles were generated by a customized thermocycler designed to automatically transport samples between heating and cooling blocks. Despite the large sample volume (50 µL), rapid two-step PCR amplification completed 40 cycles in ≤13.8 min. Variations in fluorescence intensity were measured by analyzing fluorescence images. As proof of concept of this system, we demonstrated the rapid DNA detection of pathogenic bacteria. We also compared the sensitivity of this system with that of a commercial device during the automated extraction and fast PCR of Salmonella bacteria.


Asunto(s)
Infecciones Bacterianas , Sistemas de Atención de Punto , Bacterias/genética , ADN , Humanos , Reacción en Cadena de la Polimerasa
14.
Sensors (Basel) ; 21(2)2021 Jan 08.
Artículo en Inglés | MEDLINE | ID: mdl-33435553

RESUMEN

Typically, the actual volume of the residual limb changes over time. This causes the prosthesis to not fit, and then pain and skin disease. In this study, a prosthetic socket was developed to compensate for the volume change of the residual limb. Using an inflatable air bladder, the proposed socket monitors the pressure in the socket and keeps the pressure distribution uniform and constant while walking. The socket has three air bladders on anterior and posterior tibia areas, a latching type 3-way pneumatic valve and a portable control device. In the paper, the mechanical properties of the air bladder were investigated, and the electromagnetic analysis was performed to design the pneumatic valve. The controller is based on a hysteresis control algorithm with a closed loop, which keeps the pressure in the socket close to the initial set point over a long period of time. In experiments, the proposed prosthesis was tested through the gait simulator that can imitate a human's gait cycle. The active volume compensation of the socket was successfully verified during repetitive gait cycle using the weight loads of 50, 70, and 90 kg and the residual limb model with a variety of volumes. It was confirmed that the pressure of the residual limb recovered to the initial state through the active control. The pressure inside the socket had a steady state error of less than 0.75% even if the volume of the residual limb was changed from -7% to +7%.


Asunto(s)
Muñones de Amputación , Miembros Artificiales , Humanos , Extremidad Inferior , Diseño de Prótesis , Tibia
15.
J Cell Physiol ; 235(1): 151-165, 2020 01.
Artículo en Inglés | MEDLINE | ID: mdl-31187491

RESUMEN

Slc25a17 is known as a peroxisomal solute carrier, but the in vivo role of the protein has not been demonstrated. We found that the zebrafish genome contains two slc25a17 genes that function redundantly, but additively. Notably, peroxisome function in slc25a17 knockdown embryos is severely compromised, resulting in an altered lipid composition. Along the defects found in peroxisome-associated phenotypic presentations, we highlighted that development of the swim bladder is also highly dependent on Slc25a17 function. As Slc25a17 showed substrate specificity towards coenzyme A (CoA), injecting CoA, but not NAD+ , rescued the defective swim bladder induced by slc25a17 knockdown. These results indicated that Slc25a17 acts as a CoA transporter, involved in the maintenance of functional peroxisomes that are essential for the development of multiple organs during zebrafish embryogenesis. Given high homology in protein sequences, the role of zebrafish Slc25a17 may also be applicable to the mammalian system.


Asunto(s)
Coenzima A/metabolismo , Regulación del Desarrollo de la Expresión Génica/fisiología , Proteínas de la Membrana/metabolismo , Sacos Aéreos/crecimiento & desarrollo , Sacos Aéreos/metabolismo , Secuencia de Aminoácidos , Animales , Coenzima A/genética , Secuencia Conservada , Evolución Molecular , Proteínas de la Membrana/genética , Pez Cebra
16.
Nat Mater ; 18(1): 29-34, 2019 01.
Artículo en Inglés | MEDLINE | ID: mdl-30510269

RESUMEN

Spintronics relies on magnetization switching through current-induced spin torques. However, because spin transfer torque for ferromagnets is a surface torque, a large switching current is required for a thick, thermally stable ferromagnetic cell, and this remains a fundamental obstacle for high-density non-volatile applications with ferromagnets. Here, we report a long spin coherence length and associated bulk-like torque characteristics in an antiferromagnetically coupled ferrimagnetic multilayer. We find that a transverse spin current can pass through >10-nm-thick ferrimagnetic Co/Tb multilayers, whereas it is entirely absorbed by a 1-nm-thick ferromagnetic Co/Ni multilayer. We also find that the switching efficiency of Co/Tb multilayers partially reflects a bulk-like torque characteristic, as it increases with ferrimagnet thickness up to 8 nm and then decreases, in clear contrast to the 1/thickness dependence of ferromagnetic Co/Ni multilayers. Our results on antiferromagnetically coupled systems will invigorate research towards the development of energy-efficient spintronics.

17.
Opt Lett ; 45(8): 2144-2147, 2020 Apr 15.
Artículo en Inglés | MEDLINE | ID: mdl-32287177

RESUMEN

Various standoff sensing techniques employing optical spectroscopy have been developed to address challenges in safely identifying trace amounts of explosives at a distance. A flexible anodic aluminum oxide (AAO) microcantilever and a high-power quantum cascade laser utilized as the infrared (IR) source are used for standoff IR reflection-absorption spectroscopy to detect explosive residues on a metal surface. Standoff sensing of trinitrotoluene (TNT) is demonstrated by exploiting the high thermomechanical sensitivity of a bimetallic AAO microcantilever. Moreover, sputtering gold onto the fabricated AAO nanowells generates a strong scattering and absorption of IR light in the wavelength range of 5.18 µm to 5.85 µm resulting in enhanced nanoplasmonic heating. Utilizing the IR absorption enhancement in this wavelength range, the plasmonic AAO cantilever could detect TNT molecules 7 times better than could the bimetallic AAO cantilever.

18.
Sensors (Basel) ; 20(12)2020 Jun 12.
Artículo en Inglés | MEDLINE | ID: mdl-32545495

RESUMEN

As the Internet of Things (IoT) is becoming more pervasive in our daily lives, the number of devices that connect to IoT edges and data generated at the edges are rapidly increasing. On account of the bottlenecks in servers, due to the increase in data, as well as security and privacy issues, the IoT paradigm has shifted from cloud computing to edge computing. Pursuant to this trend, embedded devices require complex computation capabilities. However, due to various constraints, edge devices cannot equip enough hardware to process data, so the flexibility of operation is reduced, because of the limitations of fixed hardware functions, relative to cloud computing. Recently, as application fields and collected data types diversify, and, in particular, applications requiring complex computation such as artificial intelligence (AI) and signal processing are applied to edges, flexible processing and computation capabilities based on hardware acceleration are required. In this paper, to meet these needs, we propose a new IoT platform, called a metamorphic IoT (mIoT) platform, which can various hardware acceleration with limited hardware platform resources, through on-demand transmission and reconfiguration of required hardware at edges instead of via transference of sensing data to a server. The proposed platform reconfigures the edge's hardware with minimal overhead, based on a probabilistic value, known as callability. The mIoT consists of reconfigurable edge devices based on RISC-V architecture and a server that manages the reconfiguration of edge devices based on callability. Through various experimental results, we confirmed that the callability-based mIoT platform can provide the hardware required by the edge device in real time. In addition, by performing various functions with small hardware, power consumption, which is a major constraint of IoT, can be reduced.

19.
Sensors (Basel) ; 20(19)2020 Oct 07.
Artículo en Inglés | MEDLINE | ID: mdl-33036476

RESUMEN

Light detection and ranging (LiDAR) sensors help autonomous vehicles detect the surrounding environment and the exact distance to an object's position. Conventional LiDAR sensors require a certain amount of power consumption because they detect objects by transmitting lasers at a regular interval according to a horizontal angular resolution (HAR). However, because the LiDAR sensors, which continuously consume power inefficiently, have a fatal effect on autonomous and electric vehicles using battery power, power consumption efficiency needs to be improved. In this paper, we propose algorithms to improve the inefficient power consumption of conventional LiDAR sensors, and efficiently reduce power consumption in two ways: (a) controlling the HAR to vary the laser transmission period (TP) of a laser diode (LD) depending on the vehicle's speed and (b) reducing the static power consumption using a sleep mode, depending on the surrounding environment. The proposed LiDAR sensor with the HAR control algorithm reduces the power consumption of the LD by 6.92% to 32.43% depending on the vehicle's speed, compared to the maximum number of laser transmissions (Nx.max). The sleep mode with a surrounding environment-sensing algorithm reduces the power consumption by 61.09%. The algorithm of the proposed LiDAR sensor was tested on a commercial processor chip, and the integrated processor was designed as an IC using the Global Foundries 55 nm CMOS process.

20.
Int J Mol Sci ; 21(19)2020 Oct 03.
Artículo en Inglés | MEDLINE | ID: mdl-33023023

RESUMEN

Anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis is an autoimmune disorder which affects small- and, to a lesser degree, medium-sized vessels. ANCA-associated vasculitis encompasses three disease phenotypes: granulomatosis with polyangiitis (GPA), microscopic polyangiitis (MPA), and eosinophilic granulomatosis with polyangiitis (EGPA). This classification is largely based on clinical presentations and has several limitations. Recent research provided evidence that genetic background, risk of relapse, prognosis, and co-morbidities are more closely related to the ANCA serotype, proteinase 3 (PR3)-ANCA and myeloperoxidase (MPO)-ANCA, compared to the disease phenotypes GPA or MPA. This finding has been extended to the investigation of biomarkers predicting disease activity, which again more closely relate to the ANCA serotype. Discoveries related to the immunopathogenesis translated into clinical practice as targeted therapies are on the rise. This review will summarize the current understanding of the immunopathogenesis of ANCA-associated vasculitis and the interplay between ANCA serotype and proposed disease biomarkers and illustrate how the extending knowledge of the immunopathogenesis will likely translate into development of a personalized medicine approach in the management of ANCA-associated vasculitis.


Asunto(s)
Vasculitis Asociada a Anticuerpos Citoplasmáticos Antineutrófilos/genética , Anticuerpos Anticitoplasma de Neutrófilos/genética , Mieloblastina/genética , Peroxidasa/genética , Vasculitis Asociada a Anticuerpos Citoplasmáticos Antineutrófilos/sangre , Vasculitis Asociada a Anticuerpos Citoplasmáticos Antineutrófilos/clasificación , Vasculitis Asociada a Anticuerpos Citoplasmáticos Antineutrófilos/patología , Anticuerpos Anticitoplasma de Neutrófilos/sangre , Biomarcadores/sangre , Síndrome de Churg-Strauss/sangre , Síndrome de Churg-Strauss/genética , Síndrome de Churg-Strauss/patología , Granulomatosis con Poliangitis/sangre , Granulomatosis con Poliangitis/genética , Granulomatosis con Poliangitis/patología , Humanos , Poliangitis Microscópica/sangre , Poliangitis Microscópica/genética , Poliangitis Microscópica/patología , Pronóstico , Serogrupo
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