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1.
Chemistry ; 30(40): e202401590, 2024 Jul 16.
Artículo en Inglés | MEDLINE | ID: mdl-38749912

RESUMEN

Photo-triggered phase transition is a new type of phase transition in which a photochromic crystal with a thermal phase transition transforms into an identical high-temperature phase in a temperature region lower than the thermal phase transition temperature upon light irradiation. Here, we report a second crystal that exhibits a photo-triggered phase transition, thereby demonstrating that the photo-triggered phase transition is a general phenomenon that occurs in crystals. When the chiral salicylidenephenylethylamine crystal was irradiated with ultraviolet (UV) light, the photo-triggered phase transition occurred in the temperature range -30 to -10 °C. The photo-triggered phase transition is induced by local stress due to trans-keto molecules produced by photoisomerization near the irradiated surface. Crystal cantilevers exhibited stepwise bending by the combination of the photo-triggered phase transition and photoisomerization. Alternate irradiation with UV and visible light achieved locomotion of single crystals driven by repeated stepwise bending. Finally, a detailed comparison of photo-triggered and non-photo-triggered phase transition crystals revealed that a sufficient molecular conformation change in affordable crystal voids, smooth photoisomerization, and most likely a chiral molecular arrangement are required for inducing the photo-triggered phase transition.

2.
Chem Soc Rev ; 52(9): 3098-3169, 2023 May 09.
Artículo en Inglés | MEDLINE | ID: mdl-37070570

RESUMEN

In the last century, molecular crystals functioned predominantly as a means for determining the molecular structures via X-ray diffraction, albeit as the century came to a close the response of molecular crystals to electric, magnetic, and light fields revealed that the physical properties of molecular crystals were as rich as the diversity of molecules themselves. In this century, the mechanical properties of molecular crystals have continued to enhance our understanding of the colligative responses of weakly bound molecules to internal frustration and applied forces. Here, the authors review the main themes of research that have developed in recent decades, prefaced by an overview of the particular considerations that distinguish molecular crystals from traditional materials such as metals and ceramics. Many molecular crystals will deform themselves as they grow under some conditions. Whether they respond to intrinsic stress or external forces or interactions among the fields of growing crystals remains an open question. Photoreactivity in single crystals has been a leading theme in organic solid-state chemistry; however, the focus of research has been traditionally on reaction stereo- and regio-specificity. However, as light-induced chemistry builds stress in crystals anisotropically, all types of motions can be actuated. The correlation between photochemistry and the responses of single crystals-jumping, twisting, fracturing, delaminating, rocking, and rolling-has become a well-defined field of research in its own right: photomechanics. The advancement of our understanding requires theoretical and high-performance computations. Computational crystallography not only supports interpretations of mechanical responses, but predicts the responses itself. This requires the engagement of classical force-field based molecular dynamics simulations, density functional theory-based approaches, and the use of machine learning to divine patterns to which algorithms can be better suited than people. The integration of mechanics with the transport of electrons and photons is considered for practical applications in flexible organic electronics and photonics. Dynamic crystals that respond rapidly and reversibly to heat and light can function as switches and actuators. Progress in identifying efficient shape-shifting crystals is also discussed. Finally, the importance of mechanical properties to milling and tableting of pharmaceuticals in an industry still dominated by active ingredients composed of small molecule crystals is reviewed. A dearth of data on the strength, hardness, Young's modulus, and fracture toughness of molecular crystals underscores the need for refinement of measurement techniques and conceptual tools. The need for benchmark data is emphasized throughout.

3.
J Am Chem Soc ; 143(23): 8866-8877, 2021 06 16.
Artículo en Inglés | MEDLINE | ID: mdl-34096298

RESUMEN

Mechanically responsive crystals have been increasingly explored, mainly based on photoisomerization. However, photoisomerization has some disadvantages for crystal actuation, such as a slow actuation speed, no actuation of thick crystals, and a narrow wavelength range. Here we report photothermally driven fast-bending actuation and simulation of a salicylideneaniline derivative crystal with an o-amino substituent in enol form. Under ultraviolet (UV) light irradiation, these thin (<20 µm) crystals bent but the thick (>40 µm) crystals did not due to photoisomerization; in contrast, thick crystals bent very quickly (in several milliseconds) due to the photothermal effect, even by visible light. Finally, 500 Hz high-frequency bending was achieved by pulsed UV laser irradiation. The generated photothermal energy was estimated based on the photodynamics using femtosecond transient absorption. Photothermal bending is caused by a nonsteady temperature gradient in the thickness direction due to the heat conduction of photothermal energy generated near the crystal surface. The temperature gradient was calculated based on the one-dimensional nonsteady heat conduction equation to simulate photothermally driven crystal bending successfully. Most crystals that absorb light have their own photothermal effects. It is expected that the creation and design of actuation of almost all crystals will be possible via the photothermal effect, which cannot be realized by photoisomerization, and the potential and versatility of crystals as actuation materials will expand in the near future.

4.
Biol Pharm Bull ; 42(5): 819-826, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-31061325

RESUMEN

Macrophage mannose receptor (MMR/CD206) is a promising target for the detection and identification of sentinel lymph node (SLN). MMR-targeting probes have been developed using mannosylated dextran, however, impairment of efficient targeting of SLN was often caused because of retention of injection site in which macrophages and dendritic cells exist. In this study, we prepared new MMR-targeting probes from yeast mannan (85 kDa), and its bioditribution was investigated. In-vivo evaluation showed that 11.9% of injected dose of 99mTc-labeled mannan-S-cysteines (99mTc-MSCs) was accumulated in popliteal lymph node (the SLN in this model), however, significant level of radioactivity (approximately 80%) was remained in injection site. Interestingly, 99mTc-labeled low molecular weight mannan-S-cysteine mannan (99mTc-LSC) prepared from 50 and 25 kDa mannan showed a decreased specific accumulation of 99mTc-LSC in the popliteal lymph node, while the radioactivity at the injection site remained unchanged. These results suggest that the molecular size, or nature/shape of the sugar chain is important for the specific accumulation of 99mTc-MSC in popliteal lymph node.


Asunto(s)
Cisteína/farmacocinética , Ganglios Linfáticos/metabolismo , Mananos/farmacocinética , Animales , Cisteína/química , Mananos/química , Ratones , Peso Molecular , Tomografía Computarizada por Tomografía Computarizada de Emisión de Fotón Único , Tecnecio , Distribución Tisular
5.
Epilepsy Behav ; 88: 251-261, 2018 11.
Artículo en Inglés | MEDLINE | ID: mdl-30317059

RESUMEN

In the past two decades, significant advances have been made on automated electroencephalogram (EEG)-based diagnosis of epilepsy and seizure detection. A number of innovative algorithms have been introduced that can aid in epilepsy diagnosis with a high degree of accuracy. In recent years, the frontiers of computational epilepsy research have moved to seizure prediction, a more challenging problem. While antiepileptic medication can result in complete seizure freedom in many patients with epilepsy, up to one-third of patients living with epilepsy will have medically intractable epilepsy, where medications reduce seizure frequency but do not completely control seizures. If a seizure can be predicted prior to its clinical manifestation, then there is potential for abortive treatment to be given, either self-administered or via an implanted device administering medication or electrical stimulation. This will have a far-reaching impact on the treatment of epilepsy and patient's quality of life. This paper presents a state-of-the-art review of recent efforts and journal articles on seizure prediction. The technologies developed for epilepsy diagnosis and seizure detection are being adapted and extended for seizure prediction. The paper ends with some novel ideas for seizure prediction using the increasingly ubiquitous machine learning technology, particularly deep neural network machine learning.


Asunto(s)
Aprendizaje Automático/tendencias , Redes Neurales de la Computación , Convulsiones/diagnóstico , Convulsiones/psicología , Algoritmos , Electroencefalografía , Epilepsia/diagnóstico , Epilepsia/fisiopatología , Epilepsia/psicología , Humanos , Valor Predictivo de las Pruebas , Calidad de Vida/psicología , Convulsiones/fisiopatología
6.
Chem Sci ; 15(3): 1088-1097, 2024 Jan 17.
Artículo en Inglés | MEDLINE | ID: mdl-38239690

RESUMEN

Materials displaying negative thermal expansion (NTE), in contrast to typical materials with positive thermal expansion (PTE), are attractive for both fundamental research and practical applications, including the development of composites with near-zero thermal expansion. A recent data mining study revealed that approximately 34% of organic crystals may present NTE, indicating that NTE in organic crystals is much more common than generally believed. However, organic crystals that switch from NTE to PTE or vice versa have rarely been reported. Here, we report the crystal of N-3,5-di-tert-butylsalicylide-3-nitroaniline in the enol form (enol-1) as the first organic crystal in which the axial thermal expansion changes from negative to positive at around room temperature. When heated, the crystal shrinks along the a-axis below 30 °C and then it expands above 30 °C. Geometric calculations revealed that below 30 °C, the decrease in the tilt angle of the molecule exceeds the increase in the interplanar distance, causing NTE, whereas above 30 °C, the increase in the interplanar distance outweighs the decrease in the tilt angle, resulting in PTE. By combining photoisomerisation and the NTE-PTE switching induced by the photothermal effect, multistep crystal photoactuation was achieved. Moreover, actuation switching of the same crystal sample by changing atmosphere temperature was realised by utilising the NTE-PTE change. Such NTE-PTE switching without a thermal phase transition provides not only new insight into organic crystals but also a new strategy for designing crystal actuators.

7.
Cogn Neurodyn ; 18(2): 383-404, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38699621

RESUMEN

Fibromyalgia is a soft tissue rheumatism with significant qualitative and quantitative impact on sleep macro and micro architecture. The primary objective of this study is to analyze and identify automatically healthy individuals and those with fibromyalgia using sleep electroencephalography (EEG) signals. The study focused on the automatic detection and interpretation of EEG signals obtained from fibromyalgia patients. In this work, the sleep EEG signals are divided into 15-s and a total of 5358 (3411 healthy control and 1947 fibromyalgia) EEG segments are obtained from 16 fibromyalgia and 16 normal subjects. Our developed model has advanced multilevel feature extraction architecture and hence, we used a new feature extractor called GluPat, inspired by the glucose chemical, with a new pooling approach inspired by the D'hondt selection system. Furthermore, our proposed method incorporated feature selection techniques using iterative neighborhood component analysis and iterative Chi2 methods. These selection mechanisms enabled the identification of discriminative features for accurate classification. In the classification phase, we employed a support vector machine and k-nearest neighbor algorithms to classify the EEG signals with leave-one-record-out (LORO) and tenfold cross-validation (CV) techniques. All results are calculated channel-wise and iterative majority voting is used to obtain generalized results. The best results were determined using the greedy algorithm. The developed model achieved a detection accuracy of 100% and 91.83% with a tenfold and LORO CV strategies, respectively using sleep stage (2 + 3) EEG signals. Our generated model is simple and has linear time complexity.

8.
Nat Commun ; 14(1): 1354, 2023 Mar 13.
Artículo en Inglés | MEDLINE | ID: mdl-36907883

RESUMEN

The flourishing field of soft robotics requires versatile actuation methodology. Natural vibration is a physical phenomenon that can occur in any material. Here, we report high-speed bending of anisole crystals by natural vibration induced by the photothermal effect. Rod-shaped crystal cantilevers undergo small, fast repetitive bending (~0.2°) due to natural vibration accompanied by large photothermal bending (~1°) under ultraviolet light irradiation. The natural vibration is greatly amplified by resonance upon pulsed light irradiation at the natural frequency to realise high frequency (~700 Hz), large bending (~4°), and high energy conversion efficiency from light to mechanical energy. The natural vibration is induced by the thermal load generated by the temperature gradient in the crystal due to the photothermal effect. The bending behaviour is successfully simulated using finite element analysis. Any light-absorbing crystal can be actuated by photothermally induced natural vibration. This finding of versatile crystal actuation can lead to the development of soft robots with high-speed and high-efficient actuation capabilities.

9.
J Pharm Sci ; 111(1): 214-224, 2022 01.
Artículo en Inglés | MEDLINE | ID: mdl-34838780

RESUMEN

The aim of this study was to develop an in vitro drug permeability methodology which mimics the gastrointestinal environment more accurately than conventional 2D methodologies through a three-dimensional (3D) Caco-2 tubules using a microphysiological system. Such a system offers significant advantages, including accelerated cellular polarization and more accurate mimicry of the in vivo environment. This methodology was confirmed by measuring the permeability of propranolol as a model compound, and subsequently applied to those of solifenacin and bile acids for a comprehensive understanding of permeability for the drug product in the human gastrointestinal tract. To protect the Caco-2 tubules from bile acid toxicity, a mucus layer was applied on the surface of Caco-2 tubules and it enables to use simulated intestinal fluid. The assessment using propranolol reproduced results equivalent to those obtained from conventional methodology, while that using solifenacin indicated fluctuations in the permeability of solifenacin due to various factors, including interaction with bile acids. We therefore suggest that this model will serve as an alternative testing system for measuring drug absorption in an environment closely resembling that of the human gastrointestinal tract.


Asunto(s)
Ácidos y Sales Biliares , Tracto Gastrointestinal , Células CACO-2 , Permeabilidad de la Membrana Celular , Humanos , Absorción Intestinal , Permeabilidad
10.
Nanoscale ; 13(21): 9698-9705, 2021 Jun 03.
Artículo en Inglés | MEDLINE | ID: mdl-34018530

RESUMEN

Oriented attachment of homogeneously shaped nanoblocks, such as nanocubes and nanorods, is attracting attention as a fundamental process of non-classical crystal growth to produce specific ordered architectures of functional materials. Although lateral alignments of horizontally oriented nanorod are commonly observed at the air-liquid and liquid-solid interfaces in dispersion systems, the accumulation of vertically oriented nanorods on a substrate has rarely been produced in a wide area over a millimeter-sized flat surface. Here, we achieved homogeneous stacking of vertical fluorapatite nanorods with a large aspect ratio (∼6) in a toluene-hexane mixture system through a gradual decrease in the dispersibility. Micrometer-thick flat films in which the c direction of fluorapatite nanorods was arranged perpendicularly to the surface were deposited on a substrate with a diameter of over 20 mm. The wide-area accumulation of vertical nanorods occurs through the self-assembly of laterally arranged clusters of nanorods covered with a stabilizing agent and subsequent gentle sedimentation on the substrate surface.

11.
Hematol Oncol ; 28(2): 68-74, 2010 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-20235332

RESUMEN

The R-CHOP regimen has been found to improve the outcome of diffuse large B-cell lymphoma (DLBCL). However, it does not provide a satisfactory treatment outcome in the high-risk group. We previously administered the CyclOBEAP regimen to patients with DLBCL, and reported its safety and efficacy. The R-CyclOBEAP regimen was administered over a total period of 12 weeks, and rituximab 375 mg/m(2) was given every 2 weeks. There were 101 eligible patients. CR was achieved in 96 patients (95%). The 5-year overall survival (OS) rate was 85% and progression-free survival (PFS) rate was 76%. When the patients were divided according to the IPI, the 5-year OS and PFS rates did not significantly differ among the risk groups. The 5-year PFS of the germinal centre B-cell group was 80% and that of the non-GCB group was 74% (NS). Univariate analysis showed that the presence of B symptoms, extranodal lesions >or=2, and sIL-2R were significant poor prognostic factors. Grade 4 neutropenia was observed in 91 patients and thrombocytopenia in 9 patients. The addition of rituximab to CyclOBEAP therapy may enhance the effect of CyclOBEAP therapy for DLBCL.


Asunto(s)
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Linfoma de Células B Grandes Difuso/tratamiento farmacológico , Adulto , Anticuerpos Monoclonales/administración & dosificación , Anticuerpos Monoclonales/efectos adversos , Anticuerpos Monoclonales de Origen Murino , Protocolos de Quimioterapia Combinada Antineoplásica/administración & dosificación , Protocolos de Quimioterapia Combinada Antineoplásica/efectos adversos , Bleomicina/administración & dosificación , Bleomicina/efectos adversos , Ciclofosfamida/administración & dosificación , Ciclofosfamida/efectos adversos , Supervivencia sin Enfermedad , Doxorrubicina/administración & dosificación , Doxorrubicina/efectos adversos , Esquema de Medicación , Etopósido/administración & dosificación , Etopósido/efectos adversos , Femenino , Humanos , Estimación de Kaplan-Meier , Masculino , Persona de Mediana Edad , Neutropenia/inducido químicamente , Prednisolona/administración & dosificación , Prednisolona/efectos adversos , Pronóstico , Rituximab , Trombocitopenia/inducido químicamente , Resultado del Tratamiento , Vincristina/administración & dosificación , Vincristina/efectos adversos , Adulto Joven
12.
Rinsho Ketsueki ; 51(3): 196-200, 2010 Mar.
Artículo en Japonés | MEDLINE | ID: mdl-20379114

RESUMEN

Marfan syndrome (MFS) is caused by mutations in the gene encoding fibrillin. A 35-year-old man with MFS visited a local physician because of a sore throat. His left tonsil gradually became swollen and he was referred to our department. Histopathological examination of tonsil biopsy specimens showed diffuse proliferation of lymphoma cells with large nuclei. The tumor cells showed CD5+, CD10+, CD20+, BCL-6+, and MUM-1-. Based on these findings, the patient was diagnosed with CD5+ CD10+ diffuse large B-cell lymphoma (DLBCL). Chemotherapy combined with rituximab was administered and complete response was achieved. CD5+ DLBCL comprises approximately 5 approximately 10% of DLBCLs. In addition, CD5+ CD10+ DLBCL comprises about 5% of CD5+ DLBCLs. There may be a relationship between MFS and B-cell lymphoma because mutations in the gene encoding the receptor of transforming growth factor-beta (TGF-beta) have been implicated in the pathogenesis of MFS and downregulation of TGF-beta receptor expression has been described in the pathology of B-cell lymphoma.


Asunto(s)
Antígenos CD5 , Linfoma de Células B Grandes Difuso/complicaciones , Síndrome de Marfan/complicaciones , Neprilisina , Adulto , Anticuerpos Monoclonales/administración & dosificación , Anticuerpos Monoclonales de Origen Murino , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Regulación hacia Abajo , Fibrilinas , Expresión Génica , Humanos , Linfoma de Células B Grandes Difuso/tratamiento farmacológico , Linfoma de Células B Grandes Difuso/genética , Linfoma de Células B Grandes Difuso/patología , Masculino , Síndrome de Marfan/genética , Proteínas de Microfilamentos/genética , Mutación , Tonsila Palatina/patología , Receptores de Factores de Crecimiento Transformadores beta/genética , Rituximab
13.
Comput Biol Med ; 111: 103331, 2019 08.
Artículo en Inglés | MEDLINE | ID: mdl-31284155

RESUMEN

Fibromyalgia is an intense musculoskeletal pain causing sleep, fatigue, and mood problems. Sleep studies have suggested that 70%-80% of fibromyalgia patients complain of non-restorative sleep. The abnormalities in sleep have been implicated as both a cause and effect of the disease. In this paper, the electroencephalogram (EEG) signals of sleep stages 2 and 3 are used to classify the normal and fibromyalgia classes automatically. We have used various nonlinear parameters, namely sample entropy (SampEn), fractal dimension (FD), higher order spectra (HOS), largest Lyapunov exponent (LLE), Kolmogorov complexity (KC), Hurst exponent (HE), energy, and power in various frequency bands from the EEG signals. Then these features are subjected to Student's t-test to select the clinically significant features, and are classified using the support vector machine (SVM) classifier. Our proposed method can classify normal and fibromyalgia subjects using the stage 2 sleep EEG signals with an accuracy of 96.15%, sensitivity and specificity of 96.88% and 95.65%, respectively. Performance of the developed system can be improved further by adding more subjects in each class, and can be employed for clinical use.


Asunto(s)
Electroencefalografía/clasificación , Fibromialgia/diagnóstico , Procesamiento de Señales Asistido por Computador , Sueño/fisiología , Adulto , Femenino , Fibromialgia/fisiopatología , Humanos , Masculino , Persona de Mediana Edad , Dinámicas no Lineales , Máquina de Vectores de Soporte
14.
Leuk Res ; 32(1): 173-5, 2008 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-17570523

RESUMEN

Primary rectal MALT lymphoma is rare comprising less than 1% of MALT lymphomas. A 26-year-old man was referred to our hospital because of constipation and abdominal fullness. Colonoscopy revealed multiple submucosal tumors in rectum. Histopathological examination showed dense proliferation of small lymphoid cells, but lymphoepithelial lesions were not observed. The cells were CD5(-), CD10(-), CD20(+) and cyclinD1(-). The patient was diagnosed as having MALT lymphoma. The patient was negative for API2-MALT1 gene, and radiotherapy was performed and CR was achieved. With the accumulation of cases, establishment of a treatment strategy for primary rectal MALT lymphoma is expected in the future.


Asunto(s)
Linfoma de Células B de la Zona Marginal/radioterapia , Proteínas de Fusión Oncogénica/genética , Neoplasias del Recto/radioterapia , Adulto , Humanos , Linfoma de Células B de la Zona Marginal/genética , Masculino , Neoplasias del Recto/genética
15.
J Oleo Sci ; 67(10): 1253-1257, 2018 Oct 11.
Artículo en Inglés | MEDLINE | ID: mdl-30210079

RESUMEN

Biotransformation of (+)- and (-)-carvone (1 and 2) by the larvae of common cutworm (Spodoptera litura) has been investigated. (+)-Carvone was transformed to (+)-(4S)-10-hydroxycarvone (1-1), (+)-(4S)-7- hydroxycarvone (1-2), and (-)-(4S)-8,9-dihydroxy-8,9-dihydrocarvone (1-3). (-)-Carvone (2) was transformed to (-)-(4R)-10-hydroxycarvone (2-1), (-)-(4R)-7-hydroxycarvone (2-2), (+)-(4R)-8,9-dihydroxy-8,9- dihydrocarvone (2-3), and (-)-(2R,4R)-10-hydroxycarveol (2-4). The results indicate that the main metabolic reaction of carvones by S. litura larvae is oxidation at vinyl group (C-8 and C-9).


Asunto(s)
Larva/metabolismo , Monoterpenos/metabolismo , Spodoptera/metabolismo , Animales , Biotransformación , Monoterpenos Ciclohexánicos , Oxidación-Reducción
16.
Comput Biol Med ; 100: 270-278, 2018 09 01.
Artículo en Inglés | MEDLINE | ID: mdl-28974302

RESUMEN

An encephalogram (EEG) is a commonly used ancillary test to aide in the diagnosis of epilepsy. The EEG signal contains information about the electrical activity of the brain. Traditionally, neurologists employ direct visual inspection to identify epileptiform abnormalities. This technique can be time-consuming, limited by technical artifact, provides variable results secondary to reader expertise level, and is limited in identifying abnormalities. Therefore, it is essential to develop a computer-aided diagnosis (CAD) system to automatically distinguish the class of these EEG signals using machine learning techniques. This is the first study to employ the convolutional neural network (CNN) for analysis of EEG signals. In this work, a 13-layer deep convolutional neural network (CNN) algorithm is implemented to detect normal, preictal, and seizure classes. The proposed technique achieved an accuracy, specificity, and sensitivity of 88.67%, 90.00% and 95.00%, respectively.


Asunto(s)
Diagnóstico por Computador , Electroencefalografía , Epilepsia/fisiopatología , Aprendizaje Automático , Redes Neurales de la Computación , Convulsiones/fisiopatología , Procesamiento de Señales Asistido por Computador , Femenino , Humanos , Masculino
17.
Comput Methods Programs Biomed ; 161: 1-13, 2018 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-29852952

RESUMEN

BACKGROUND AND OBJECTIVE: We have cast the net into the ocean of knowledge to retrieve the latest scientific research on deep learning methods for physiological signals. We found 53 research papers on this topic, published from 01.01.2008 to 31.12.2017. METHODS: An initial bibliometric analysis shows that the reviewed papers focused on Electromyogram(EMG), Electroencephalogram(EEG), Electrocardiogram(ECG), and Electrooculogram(EOG). These four categories were used to structure the subsequent content review. RESULTS: During the content review, we understood that deep learning performs better for big and varied datasets than classic analysis and machine classification methods. Deep learning algorithms try to develop the model by using all the available input. CONCLUSIONS: This review paper depicts the application of various deep learning algorithms used till recently, but in future it will be used for more healthcare areas to improve the quality of diagnosis.


Asunto(s)
Diagnóstico por Computador/métodos , Aprendizaje Automático , Informática Médica/métodos , Algoritmos , Electrocardiografía , Electroencefalografía , Electromiografía , Electrooculografía , Humanos , Modelos Lineales , Neuronas , Calidad de la Atención de Salud , Procesamiento de Señales Asistido por Computador
18.
Comput Biol Med ; 102: 234-241, 2018 11 01.
Artículo en Inglés | MEDLINE | ID: mdl-30253869

RESUMEN

Parkinson's disease (PD) is a neurodegenerative disease of the central nervous system caused due to the loss of dopaminergic neurons. It is classified under movement disorder as patients with PD present with tremor, rigidity, postural changes, and a decrease in spontaneous movements. Comorbidities including anxiety, depression, fatigue, and sleep disorders are observed prior to the diagnosis of PD. Gene mutations, exposure to toxic substances, and aging are considered as the causative factors of PD even though its genesis is unknown. This paper reviews PD etiologies, progression, and in particular measurable indicators of PD such as neuroimaging and electrophysiology modalities. In addition to gene therapy, neuroprotective, pharmacological, and neural transplantation treatments, researchers are actively aiming at identifying biological markers of PD with the goal of early diagnosis. Neuroimaging modalities used together with advanced machine learning techniques offer a promising path for the early detection and intervention in PD patients.


Asunto(s)
Enfermedad de Parkinson/diagnóstico , Enfermedad de Parkinson/etiología , Enfermedad de Parkinson/terapia , Encéfalo/diagnóstico por imagen , Comorbilidad , Aprendizaje Profundo , Progresión de la Enfermedad , Neuronas Dopaminérgicas/fisiología , Diagnóstico Precoz , Fenómenos Electrofisiológicos , Humanos , Aprendizaje Automático , Trastornos del Movimiento/fisiopatología , Mutación , Neuroimagen , Trastornos del Sueño-Vigilia/fisiopatología
19.
Comput Biol Med ; 92: 204-209, 2018 01 01.
Artículo en Inglés | MEDLINE | ID: mdl-29227822

RESUMEN

Untreated age-related macular degeneration (AMD), diabetic retinopathy (DR), and glaucoma may lead to irreversible vision loss. Hence, it is essential to have regular eye screening to detect these eye diseases at an early stage and to offer treatment where appropriate. One of the simplest, non-invasive and cost-effective techniques to screen the eyes is by using fundus photo imaging. But, the manual evaluation of fundus images is tedious and challenging. Further, the diagnosis made by ophthalmologists may be subjective. Therefore, an objective and novel algorithm using the pyramid histogram of visual words (PHOW) and Fisher vectors is proposed for the classification of fundus images into their respective eye conditions (normal, AMD, DR, and glaucoma). The proposed algorithm extracts features which are represented as words. These features are built and encoded into a Fisher vector for classification using random forest classifier. This proposed algorithm is validated with both blindfold and ten-fold cross-validation techniques. An accuracy of 90.06% is achieved with the blindfold method, and highest accuracy of 96.79% is obtained with ten-fold cross-validation. The highest classification performance of our system shows the potential of deploying it in polyclinics to assist healthcare professionals in their initial diagnosis of the eye. Our developed system can reduce the workload of ophthalmologists significantly.


Asunto(s)
Técnicas de Diagnóstico Oftalmológico , Interpretación de Imagen Asistida por Computador/métodos , Retina/diagnóstico por imagen , Enfermedades de la Retina/diagnóstico por imagen , Algoritmos , Fondo de Ojo , Glaucoma/diagnóstico por imagen , Humanos
20.
J Zhejiang Univ Sci B ; 19(1): 6-24, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-29308604

RESUMEN

Radiology (imaging) and imaging-guided interventions, which provide multi-parametric morphologic and functional information, are playing an increasingly significant role in precision medicine. Radiologists are trained to understand the imaging phenotypes, transcribe those observations (phenotypes) to correlate with underlying diseases and to characterize the images. However, in order to understand and characterize the molecular phenotype (to obtain genomic information) of solid heterogeneous tumours, the advanced sequencing of those tissues using biopsy is required. Thus, radiologists image the tissues from various views and angles in order to have the complete image phenotypes, thereby acquiring a huge amount of data. Deriving meaningful details from all these radiological data becomes challenging and raises the big data issues. Therefore, interest in the application of radiomics has been growing in recent years as it has the potential to provide significant interpretive and predictive information for decision support. Radiomics is a combination of conventional computer-aided diagnosis, deep learning methods, and human skills, and thus can be used for quantitative characterization of tumour phenotypes. This paper discusses the overview of radiomics workflow, the results of various radiomics-based studies conducted using various radiological images such as computed tomography (CT), magnetic resonance imaging (MRI), and positron-emission tomography (PET), the challenges we are facing, and the potential contribution of radiomics towards precision medicine.


Asunto(s)
Medicina de Precisión/métodos , Radiología Intervencionista/métodos , Radiología/métodos , Biomarcadores de Tumor , Diagnóstico por Computador , Genoma , Genómica , Humanos , Imagen por Resonancia Magnética , Neoplasias/terapia , Fenotipo , Tomografía de Emisión de Positrones , Tomografía Computarizada por Rayos X , Flujo de Trabajo
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