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1.
J Magn Reson Imaging ; 59(2): 599-610, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-37203312

RESUMEN

BACKGROUND: Diffusion magnetic resonsance imaging (dMRI) can potentially predict the postoperative outcome of cervical spondylotic myelopathy (CSM). PURPOSE: To explore preoperative dMRI parameters to predict the postoperative outcome of CSM through multifactor correlation analysis. STUDY TYPE: Prospective. POPULATION: Post-surgery CSM patients; 102 total, 73 male (52.42 ± 10.60 years old) and 29 female (52.0 ± 11.45 years old). FIELD STRENGTH/SEQUENCE: 3.0 T/Turbo spin echo T1/T2-weighted, T2*-weighted multiecho gradient echo and dMRI. ASSESSMENT: Spinal cord function was evaluated using modified Japanese Orthopedic Association (mJOA) scoring at different time points: preoperative and 3, 6, and 12 months postoperative. Single-factor correlation and t test analyses were conducted based on fractional anisotropy (FA), mean diffusivity, intracellular volume fraction, isotropic volume fraction, orientation division index, increased signal intensity, compression ratio, age, sex, symptom duration and operation method, and multicollinearity was calculated. The linear quantile mixed model (LQMM) and the linear mixed-effects regression model (LMER) were used for multifactor correlation analysis using the combinations of the above variables. STATISTICAL TESTS: Distance correlation, Pearson's correlation, multiscale graph correlation and t tests were used for the single-factor correlation analyses. The variance inflation factor (VIF) was used to calculate multicollinearity. LQMM and LMER were used for multifactor correlation analyses. P < 0.05 was considered statistically significant. RESULTS: The single-factor correlation between all variables and the postoperative mJOA score was weak (all r < 0.3). The linear relationship was stronger than the nonlinear relationship, and there was no significant multicollinearity (VIF = 1.10-1.94). FA values in the LQMM and LMER models had a significant positive correlation with the mJOA score (r = 5.27-6.04), which was stronger than the other variables. DATA CONCLUSION: The FA value based on dMRI significantly positively correlated with CSM patient postoperative outcomes, helping to predict the surgical outcome and formulate a treatment plan before surgery. EVIDENCE LEVEL: 1 TECHNICAL EFFICACY: Stage 2.


Asunto(s)
Enfermedades de la Médula Espinal , Espondilosis , Humanos , Masculino , Femenino , Adulto , Persona de Mediana Edad , Estudios Prospectivos , Imagen de Difusión Tensora/métodos , Espondilosis/diagnóstico por imagen , Espondilosis/cirugía , Espondilosis/patología , Enfermedades de la Médula Espinal/diagnóstico por imagen , Enfermedades de la Médula Espinal/cirugía , Imagen por Resonancia Magnética , Imagen de Difusión por Resonancia Magnética , Vértebras Cervicales/diagnóstico por imagen , Vértebras Cervicales/cirugía , Resultado del Tratamiento
2.
J Magn Reson Imaging ; 55(3): 930-940, 2022 03.
Artículo en Inglés | MEDLINE | ID: mdl-34425037

RESUMEN

BACKGROUND: Diffusion-weighted imaging (DWI) can quantify the microstructural changes in the spinal cord. It might be a substitute for T2 increased signal intensity (ISI) for cervical spondylotic myelopathy (CSM) evaluation and prognosis. PURPOSE: The purpose of the study is to investigate the relationship between DWI metrics and neurologic function of patients with CSM. STUDY TYPE: Retrospective. POPULATION: Forty-eight patients with CSM (18.8% females) and 36 healthy controls (HCs, 25.0% females). FIELD STRENGTH/SEQUENCE: 3 T; spin-echo echo-planar imaging-DWI; turbo spin-echo T1/T2; multi-echo gradient echo T2*. ASSESSMENT: For patients, conventional MRI indicators (presence and grades of T2 ISI), DWI indicators (neurite orientation dispersion and density imaging [NODDI]-derived isotropic volume fraction [ISOVF], intracellular volume fraction, and orientation dispersion index [ODI], diffusion tensor imaging [DTI]-derived fractional anisotropy [FA] and mean diffusivity [MD], and diffusion kurtosis imaging [DKI]-derived FA, MD, and mean kurtosis), clinical conditions, and modified Japanese Orthopaedic Association (mJOA) were recorded before the surgery. Neurologic function improvement was measured by the 3-month follow-up recovery rate (RR). For HCs, DWI, and mJOA were measured as baseline comparison. STATISTICAL TESTS: Continuous (categorical) variables were compared between patients and HCs using Student's t-tests or Mann-Whitney U tests (chi-square or Fisher exact tests). The relationships between DWI metrics/conventional MRI findings, and the pre-operative mJOA/RR were assessed using correlation and multivariate analysis. P < 0.05 was considered statistically significant. RESULTS: Among patients, grades of T2 ISI were not correlated with pre-surgical mJOA/RR (P = 0.717  and 0.175, respectively). NODDI ODI correlated with pre-operative mJOA (r = -0.31). DTI FA, DKI FA, and NODDI ISOVF were correlated with the recovery rate (r = 0.31, 0.41, and -0.34, respectively). In multivariate analysis, NODDI ODI (DTI FA, DKI FA, NODDI ISOVF) significantly contributed to the pre-operative mJOA (RR) after adjusting for age. DATA CONCLUSION: DTI FA, DKI FA, and NODDI ISOVF are predictors for prognosis in patients with CSM. NODDI ODI can be used to evaluate CSM severity. LEVEL OF EVIDENCE: 3 TECHNICAL EFFICACY STAGE: 5.


Asunto(s)
Enfermedades de la Médula Espinal , Espondilosis , Vértebras Cervicales/diagnóstico por imagen , Vértebras Cervicales/cirugía , Imagen de Difusión Tensora/métodos , Femenino , Humanos , Masculino , Estudios Retrospectivos , Enfermedades de la Médula Espinal/complicaciones , Enfermedades de la Médula Espinal/diagnóstico por imagen , Espondilosis/complicaciones , Espondilosis/diagnóstico por imagen
3.
Eur Radiol ; 32(6): 3855-3862, 2022 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-35084519

RESUMEN

OBJECTIVES: To evaluate the feasibility of proximal nerve MR neurography with diffusion tensor imaging (DTI) for differentiating Charcot-Marie-Tooth (CMT) 1A, CMT2, and healthy controls. METHODS: The diameters, fractional anisotropy (FA), mean diffusivity (MD), axial diffusivity (AD), and radial diffusivity (RD) of L4-L5 nerve roots, femoral nerve (FN), and sciatic nerve (SN) were compared. Receiver operating characteristic (ROC) curve analyses were conducted to evaluate the diagnostic performance. DeLong's tests were applied to compare multiple ROC curves. Intraclass correlation coefficients were calculated for interobserver agreement assessment. RESULTS: The diameters of the L4 nerve root, L5 nerve root, and SN of CMT1A patients were significantly larger than those of CMT2 patients and healthy controls. The FA values of all measured proximal nerves were significantly higher in controls (0.46 ± 0.09, 0.46 ± 0.08, 0.45 ± 0.07, and 0.48 ± 0.08) than in CMT1A patients (0.30 ± 0.09, 0.29 ± 0.06, 0.35 ± 0.08, and 0.29 ± 0.09). The FA values of the L5 nerve root, FN, and SN were significantly higher in controls (0.46 ± 0.08, 0.45 ± 0.07, and 0.48 ± 0.08) than in CMT2 patients (0.36 ± 0.06, 0.34 ± 0.07, and 0.34 ± 0.10). The MD and RD values of the L5 nerve root in CMT1A patients (1.59 ± 0.21 and 1.37 ± 0.21) were higher than those in CMT2 patients (1.31 ± 0.17 and 1.05 ± 0.14). The AUCs of the above parameters ranged from 0.780 to 1.000. For the measurements of nerve diameters, the ICC ranged from 0.91 to 0.97. For the measurements of DTI metrics, the ICC ranged from 0.87 to 0.97. CONCLUSIONS: MR neurography with DTI is able to differentiate CMT1A patients, CMT2 patients, and healthy controls. KEY POINTS: • MR neurography with diffusion tensor imaging of the L4-5 nerve roots, proximal femoral nerve, and proximal sciatic nerve is able to discriminate CMT1A, CMT2, and healthy controls. • This method provides an alternative for the diagnosis and discrimination of CMT1A and CMT2, which is crucial for clinical management.


Asunto(s)
Enfermedad de Charcot-Marie-Tooth , Imagen de Difusión Tensora , Anisotropía , Enfermedad de Charcot-Marie-Tooth/diagnóstico por imagen , Imagen de Difusión Tensora/métodos , Humanos , Estudios Prospectivos , Nervio Ciático/diagnóstico por imagen
4.
Eur Radiol ; 32(5): 3565-3575, 2022 May.
Artículo en Inglés | MEDLINE | ID: mdl-35024949

RESUMEN

OBJECTIVES: Conventional MRI may not be ideal for predicting cervical spondylotic myelopathy (CSM) prognosis. In this study, we used radiomics in predicting postoperative recovery in CSM. We aimed to develop and validate radiomic feature-based extra trees models. METHODS: There were 151 patients with CSM who underwent preoperative T2-/ T2*-weighted imaging (WI) and surgery. They were divided into good/poor outcome groups based on the recovery rate. Datasets from multiple scanners were randomised into training and internal validation sets, while the dataset from an independent scanner was used for external validation. Radiomic features were extracted from the transverse spinal cord at the maximum compressed level. Threshold selection algorithm, collinearity removal, and tree-based feature selection were applied sequentially in the training set to obtain the optimal radiomic features. The classification of intramedullary increased signal on T2/T2*WI and compression ratio of the spinal cord on T2*WI were selected as the conventional MRI features. Clinical features were age, preoperative mJOA, and symptom duration. Four models were constructed: radiological, radiomic, clinical-radiological, and clinical-radiomic. An AUC significantly > 0.5 was considered meaningful predictive performance based on the DeLong test. The mean decrease in impurity was used to measure feature importance. p < 0.05 was considered statistically significant. RESULTS: On internal and external validations, AUCs of the radiomic and clinical-radiomic models, and radiological and clinical-radiological models ranged from 0.71 to 0.81 (significantly > 0.5) and 0.40 to 0.55, respectively. Wavelet-LL first-order variance was the most important feature in the radiomic model. CONCLUSION: Radiomic features, especially wavelet-LL first-order variance, contribute to meaningful predictive models for CSM prognosis. KEY POINTS: • Conventional MRI features may not be ideal in predicting prognosis. • Radiomics provides greater predictive efficiency in the recovery from cervical spondylotic myelopathy.


Asunto(s)
Enfermedades de la Médula Espinal , Espondilosis , Vértebras Cervicales/diagnóstico por imagen , Vértebras Cervicales/cirugía , Descompresión Quirúrgica/métodos , Humanos , Imagen por Resonancia Magnética/métodos , Periodo Posoperatorio , Estudios Retrospectivos , Enfermedades de la Médula Espinal/diagnóstico por imagen , Enfermedades de la Médula Espinal/cirugía , Espondilosis/diagnóstico por imagen , Espondilosis/cirugía , Resultado del Tratamiento
5.
Molecules ; 28(1)2022 Dec 28.
Artículo en Inglés | MEDLINE | ID: mdl-36615452

RESUMEN

This paper selected microplastic polyethylene terephthalate (PET), commonly found in water/wastewater plant effluent, to investigate the changes of PET oxidized under ozonation (designated as ozonized PET), followed by sodium hypochlorite oxidation (designated as ozonized-chlorinated PET) and studied their influence on the adsorption of the disinfection by-product bromoform (TBM). Fragmentation and cracks appeared on the oxidized PET surface. As the oxidation degree increased, the contact angle decreased from 137° to 128.90° and 128.50°, suggesting hydrophilicity was enhanced. FTIR and XPS analyses suggested that carbonyl groups increased on the surface of ozonized PET and ozonized-chlorinated PET, while the formation of intermolecular halogen bonds was possible when PET experienced dual oxidation. These physiochemical changes enhanced the adsorption of TBM. The adsorption capacity of TBM followed the order of ozonized-chlorinated PET (2.64 × 10−6 µg/µg) > ozonized PET (2.58 × 10−6 µg/µg) > pristine PET (2.43 × 10−6 µg/µg). The impact of raw water characteristics on the adsorption of TBM onto PETs, such as the pH, and the coexistence of inorganic ions and macromolecules (humic acid, surfactant, and bovine serum albumin) were studied. A different predominant adsorption mechanism between TBM and pristine PET or oxidized PETs was proposed.


Asunto(s)
Ozono , Contaminantes Químicos del Agua , Microplásticos , Plásticos , Tereftalatos Polietilenos/química , Halogenación , Adsorción , Agua , Ozono/química , Contaminantes Químicos del Agua/química
6.
Clin Exp Hypertens ; 43(3): 295-304, 2021 Apr 03.
Artículo en Inglés | MEDLINE | ID: mdl-33371762

RESUMEN

Purpose: We studied the expression of urotensin II (UII) and its relationships with markers of pyroptosis in preeclampsia. Methods: 48 pregnant subjects were recruited consisting of 28 severe preeclampsia pregnancies (SPE) and 20 healthy pregnancies. We detected expressions of UII and markers of pyroptosis such as NLR-family pyrin domain (PYD)-containing 3 (NLRP-3), caspase-1/4/5, interleukin-1ß (IL-1ß), and gasdermin D (GSDMD) in placentas of patients with SPE and healthy pregnancies. Results: SPE group have higher expression of UII and NLRP-3, caspase-1, interleukin-1ß (IL-1ß), and GSDMD than that normal controls by IHC, real-time PCR, and western blot. IHC analysis manifests that the expressions of UII and pyroptosis-related molecules are mainly located in the placental cytotrophoblasts. Expressions of UII mRNA and protein are significantly positively correlated with pyroptosis marker such as NLRP3, caspase-1, GSDMD mRNA and protein by Pearson correlation analysis. Moreover, UII, NLRP-3, caspase-1, interleukin-1ß (IL-1ß), and GSDMD are positively related with systolic blood pressure, meanwhile caspase-1 and GSDMD are positively correlated with urine protein in SPE patients. We firstly verify that UII has a positive correlation with pyroptosis markers in placentas of preeclampsia patients; besides, pyroptosis-related proteins are positively correlated with systolic blood pressure and urine protein in patients with severe preeclampsia.


Asunto(s)
Preeclampsia/sangre , Preeclampsia/patología , Piroptosis , Urotensinas/metabolismo , Adulto , Biomarcadores/metabolismo , Presión Sanguínea , Estudios de Casos y Controles , Caspasas/metabolismo , Femenino , Humanos , Interleucina-1beta , Péptidos y Proteínas de Señalización Intracelular/metabolismo , Proteína con Dominio Pirina 3 de la Familia NLR/metabolismo , Proteínas de Unión a Fosfato/metabolismo , Placenta/metabolismo , Placenta/patología , Preeclampsia/genética , Embarazo , ARN Mensajero/genética , ARN Mensajero/metabolismo , Regulación hacia Arriba/genética , Urotensinas/genética
7.
Artículo en Inglés | MEDLINE | ID: mdl-38529606

RESUMEN

BACKGROUND: Transplantation of neural stem cells improves ischemic stroke outcomes in rodent models and is currently in the clinical test stage. However, the optimal delivery route to achieve improved efficacy remains undetermined. OBJECTIVE: This study aims to evaluate three more clinically feasible delivery routes: intravenous (IV), intranasal (IN), and intracerebroventricular (ICV). We compared the therapeutic efficacies of the three routes of transplanting human neural stem cells (hNSCs) into mice with permanent middle cerebral artery obstruction (pMCAO). METHODS: Behavioral tests and cresyl violet staining were used to evaluate the therapeutic efficacies of functional recovery and lesion volumes. The expression of proinflammatory cytokines and neurotrophic factors was measured by real-time PCR. The distribution and differentiation of hNSCs were determined by immunofluorescence staining. The effect on endogenous neurogenesis and astrocyte function were determined by immunofluorescence staining and western blot. RESULTS: hNSC transplantation using the three routes improved behavioral outcomes and reduced lesion volumes; IV transplantation of hNSCs results in earlier efficacy and improves the inflammatory microenvironment. The long-term distribution and differentiation of transplanted hNSCs in the peri-infarct areas can only be evaluated using ICV delivery. IV and ICV transplantation of hNSCs promote neurogenesis and modulate the dual function of astrocytes in the peri-infarct areas. CONCLUSION: IV and IN delivery is suitable for repeated administration of hNSCs to achieve improved prognosis. Comparatively, ICV transplantation provides long-term efficacy at lower doses and fewer administration times.

8.
J Prosthodont Res ; 68(1): 63-77, 2024 Jan 16.
Artículo en Inglés | MEDLINE | ID: mdl-37316260

RESUMEN

PURPOSE: To investigate survival rates and technical and biological complications of one-piece screw-retained hybrid abutments in implant-supported single crowns (SCs). STUDY SELECTION: An electronic search was performed on five databases for clinical studies involving implant-supported single hybrid abutment crowns constructed using titanium-base (Ti base) abutments, with at least 12 months of follow-up. The RoB 2, Robins-I, and JBI tools were used to assess the risk of bias for the different study types. Success, survival, and complication rates were calculated, and a meta-analysis was performed to obtain a pooled estimate. Peri-implant health parameters were extracted and analyzed. RESULTS: 22 records (20 studies) were included in this analysis. Direct comparisons between screw-retained hybrid abutment SCs and cemented SCs showed no significant differences in the 1-year survival and success rates. For SCs using a hybrid abutment crown design, their 1-year survival rate was 100% (95% CI: 100%-100%, I2 = 0.0%, P = 0.984), and a success rate of 99% (95% CI: 97%-100%, I2 = 50.3%, P = 0.023) was calculated. No confounding variables significantly affected the estimates. The individual technical complication rate was low at 1-year follow-up. The estimated incidence of all types of complications in hybrid abutment SCs is less than 1%. CONCLUSIONS: Within the limitations of this study, implant-supported SCs using a hybrid abutment crown design showed favorable short-term clinical outcomes. Additional well-designed clinical trials with at least a 5-year observation period are required to confirm their long-term clinical performance.


Asunto(s)
Coronas , Pilares Dentales , Prótesis Dental de Soporte Implantado , Fracaso de la Restauración Dental , Titanio , Humanos
9.
Comput Med Imaging Graph ; 116: 102402, 2024 May 21.
Artículo en Inglés | MEDLINE | ID: mdl-38810486

RESUMEN

Accurately assessing carotid artery wall thickening and identifying risky plaque components are critical for early diagnosis and risk management of carotid atherosclerosis. In this paper, we present a 3D framework for automated segmentation of the carotid artery vessel wall and identification of the compositions of carotid plaque in multi-sequence magnetic resonance (MR) images under the challenge of imperfect manual labeling. Manual labeling is commonly done in 2D slices of these multi-sequence MR images and often lacks perfect alignment across 2D slices and the multiple MR sequences, leading to labeling inaccuracies. To address such challenges, our framework is split into two parts: a segmentation subnetwork and a plaque component identification subnetwork. Initially, a 2D localization network pinpoints the carotid artery's position, extracting the region of interest (ROI) from the input images. Following that, a signed-distance-map-enabled 3D U-net (Çiçek etal, 2016)an adaptation of the nnU-net (Ronneberger and Fischer, 2015) segments the carotid artery vessel wall. This method allows for the concurrent segmentation of the vessel wall area using the signed distance map (SDM) loss (Xue et al., 2020) which regularizes the segmentation surfaces in 3D and reduces erroneous segmentation caused by imperfect manual labels. Subsequently, the ROI of the input images and the obtained vessel wall masks are extracted and combined to obtain the identification results of plaque components in the identification subnetwork. Tailored data augmentation operations are introduced into the framework to reduce the false positive rate of calcification and hemorrhage identification. We trained and tested our proposed method on a dataset consisting of 115 patients, and it achieves an accurate segmentation result of carotid artery wall (0.8459 Dice), which is superior to the best result in published studies (0.7885 Dice). Our approach yielded accuracies of 0.82, 0.73 and 0.88 for the identification of calcification, lipid-rich core and hemorrhage components. Our proposed framework can be potentially used in clinical and research settings to help radiologists perform cumbersome reading tasks and evaluate the risk of carotid plaques.

10.
Environ Sci Pollut Res Int ; 30(31): 77488-77498, 2023 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-37256407

RESUMEN

Two in situ formed Fe(III) oxyhydroxides (FeOx) originated from ferrate reduction (designated FeOx-FeVI) and ferrous oxidation by H2O2 (designated FeOx-FeII) were compared in the aspects of morphology, hydrolyzed species, surface binding mechanism of lead. The theoretical maximum adsorption capacity calculated from the Langmuir model toward Pb(II) was 929.54 and 810.37 mg/g Fe by FeOx-FeVI and FeOx-FeII, respectively. At pH 6 and the same Fe/Pb ratio, the kinetic rate of Pb removal by the FeOx-FeVI process was 8 times faster. FTIR, SEM, and Ferron assay suggest FeOx-FeVI was associated with a lesser polymerization degree and contained more reactive hydroxyl-Fe polymers than those in the FeOx-FeII sample. SAXS verified that the particles possessed a smaller, more homogeneous, and open structure when Fe was hydrolyzed by ferrate reduction than ferrous oxidation. XPS coupled with fractal analysis suggests the different sorption capacities of Pb(II) can be ascribed to their distinct growth patterns. Fast cluster agglomeration during FeOx-FeII fabrication decreased the exposure of effective adsorption sites. In comparison, the incompact assemblies of FeOx-FeVI clusters facilitated Pb(II) ions to access the interstices of octahedral FeO6 units and formed an edge-sharing complex. This work provides new insight into mechanisms of particle fabrication and heavy metal removal of Fe(III) formed in situ.


Asunto(s)
Compuestos Férricos , Contaminantes Químicos del Agua , Compuestos Férricos/química , Plomo , Peróxido de Hidrógeno , Adsorción , Dispersión del Ángulo Pequeño , Difracción de Rayos X , Oxidación-Reducción , Compuestos Ferrosos , Contaminantes Químicos del Agua/análisis
11.
Curr Stem Cell Res Ther ; 18(3): 380-390, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-35410620

RESUMEN

BACKGROUND: Neural stem/progenitor cells (NSPCs) transplantation has been recognized in recent years as an effective strategy for the treatment of ischemic stroke. Several preclinical studies have demonstrated the feasibility, safety, and efficacy of NSPCs therapy. METHODS: We conducted a systematic review of the published literature in Pubmed reporting the use of NSPCs in preclinical studies between 2010 and 2021. Based on the articles reporting data, the key factors affecting efficacy were listed. RESULTS: A total of 71 preclinical studies, including 91 treatment arms, were identified. The results showed that several factors could influence the outcomes of NSPCs transplantation, including the type of donor cells, cell dose, time of administration after stroke, delivery route, and anesthetic. Treatment outcomes were measured by infarct volume, behavioral tests, and molecular and cellular level results. CONCLUSION: Most of the preclinical studies reported statistically significant effects and very few adverse reactions. Transplantation of NSPCs for ischemic stroke still needs to be optimized for several key factors. A standardized treatment outcome assessment could ease the translation of evidence in clinical settings.


Asunto(s)
Accidente Cerebrovascular Isquémico , Células-Madre Neurales , Accidente Cerebrovascular , Humanos , Accidente Cerebrovascular Isquémico/terapia , Accidente Cerebrovascular Isquémico/metabolismo , Células-Madre Neurales/metabolismo , Accidente Cerebrovascular/terapia , Accidente Cerebrovascular/metabolismo , Trasplante de Células Madre/métodos , Resultado del Tratamiento
12.
Front Psychol ; 13: 1014199, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36438369

RESUMEN

This study investigates how the quality of service experience (QSE) impacts users' satisfaction and loyalty to music streaming services. To this end, the sense of insufficient time to do things, a moderated mediation model, is adopted to examine the mediating role of satisfaction and the moderating role of time pressure from working. By using structural equation modeling, the results reveal that QSE is positively related to users' satisfaction and loyalty to music streaming services. The results also show that the QSE positively influences users' loyalty through satisfaction. Furthermore, time pressure, acting as a moderator, positively affects the relationship between QSE and satisfaction and the relationship between satisfaction and loyalty.

13.
Stem Cell Rev Rep ; 18(5): 1774-1788, 2022 06.
Artículo en Inglés | MEDLINE | ID: mdl-35122628

RESUMEN

Neural stem cell (NSC) therapies are developing rapidly and have been proposed as a treatment option for various neurological diseases, such as stroke, Parkinson's disease and multiple sclerosis. However, monitoring transplanted NSCs, exploring their location and migration, and evaluating their efficacy and safety have all become serious and important issues. Two main problems in tracking NSCs have been noted: labeling them for visibility and imaging them. Direct labeling and reporter gene labeling are the two main methods for labeling stem cells. Magnetic resonance imaging and nuclear imaging, including positron emission tomography, single-photon emission computed tomography, and optical imaging, are the most commonly used imaging techniques. Each has its strengths and weaknesses. Thus, multimodal imaging, which combines two or more imaging methods to complement the advantages and disadvantages of each, has garnered increased attention. Advances in image fusion and nanotechnology, as well as the exploration of new tracers and new imaging modalities have substantially facilitated the development of NSC tracking technology. However, the safety issues related to tracking and long-term tracking of cell viability are still challenges. In this review, we discuss the merits and defects of different labeling and imaging methods, as well as recent advances, challenges and prospects in NSC tracking.


Asunto(s)
Células-Madre Neurales , Accidente Cerebrovascular , Supervivencia Celular , Humanos , Imagen por Resonancia Magnética/métodos , Tomografía de Emisión de Positrones
15.
Tomography ; 7(4): 767-782, 2021 11 12.
Artículo en Inglés | MEDLINE | ID: mdl-34842849

RESUMEN

This paper proposes a deep-learning-based image enhancement approach that can generate high-resolution micro-CT-like images from multidetector computed tomography (MDCT). A total of 12,500 MDCT and micro-CT image pairs were obtained from 25 vertebral specimens. Then, a pix2pixHD model was trained and evaluated using the structural similarity index measure (SSIM) and Fréchet inception distance (FID). We performed subjective assessments of the micro-CT-like images based on five aspects. Micro-CT and micro-CT-like image-derived trabecular bone microstructures were compared, and the underlying correlations were analyzed. The results showed that the pix2pixHD method (SSIM, 0.804 ± 0.037 and FID, 43.598 ± 9.108) outperformed the two control methods (pix2pix and CRN) in enhancing MDCT images (p < 0.05). According to the subjective assessment, the pix2pixHD-derived micro-CT-like images showed no significant difference from the micro-CT images in terms of contrast and shadow (p > 0.05) but demonstrated slightly lower noise, sharpness and trabecular bone texture (p < 0.05). Compared with the trabecular microstructure parameters of micro-CT images, those of pix2pixHD-derived micro-CT-like images showed no significant differences in bone volume fraction (BV/TV) (p > 0.05) and significant correlations in trabecular thickness (Tb.Th) and trabecular spacing (Tb.Sp) (Tb.Th, R = 0.90, p < 0.05; Tb.Sp, R = 0.88, p < 0.05). The proposed method can enhance the resolution of MDCT and obtain micro-CT-like images, which may provide new diagnostic criteria and a predictive basis for osteoporosis and related fractures.


Asunto(s)
Aprendizaje Profundo , Tomografía Computarizada Multidetector , Huesos , Columna Vertebral , Microtomografía por Rayos X/métodos
16.
ACS Omega ; 6(20): 13484-13495, 2021 May 25.
Artículo en Inglés | MEDLINE | ID: mdl-34056495

RESUMEN

Denitration (De-NO x ) over activated cokes (ACs) for sintering flue gas needs intensification. Gaseous reactions in a gas mixture containing NO, NO2, and NH3, with the effect of O2 concentration and moisture, were taken into consideration in the study of NO x conversion over ACs. Experimental studies on NO x conversion with and without NH3 over ACs were conducted using a fixed-bed reactor at 100 °C. The results demonstrated that moisture significantly affected NO x removal over ACs, especially the NO2 conversion. Under dry conditions, a disproportionation reaction of NO2 over ACs dominated NO x conversion with no NH3, whereas apparent fast selective catalytic reduction (SCR) over the ACs was observed in the presence of NH3. Regardless of the presence of absence of NH3 in wet mixtures, NO2 adsorption on ACs via the disproportionation route dominated the NO x conversion. Increasing the NO2/NO ratio in the simulated flue gas enhanced the NO x conversion rate over ACs. -C(ONO2) deposition on ACs generated by the disproportionation route inhibited NO x conversion with time. O3 oxidation was found to be efficient in increasing the NO2/NO ratio and intensifying the NO x conversion compared with commercially direct NH3-SCR over ACs. Increasing the temperature and decreasing the gas hourly space velocity can promote NO x conversion over ACs after O3 oxidation. NO oxidized with O3 coupled with NH3 spray and continuous regeneration of ACs is a potential method for removing NO x from sintering flue gas.

17.
JOR Spine ; 4(4): e1178, 2021 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-35005444

RESUMEN

INTRODUCTION: Predicting the postoperative neurological function of cervical spondylotic myelopathy (CSM) patients is generally based on conventional magnetic resonance imaging (MRI) patterns, but this approach is not completely satisfactory. This study utilized radiomics, which produced advanced objective and quantitative indicators, and machine learning to develop, validate, test, and compare models for predicting the postoperative prognosis of CSM. MATERIALS AND METHODS: In total, 151 CSM patients undergoing surgical treatment and preoperative MRI was retrospectively collected and divided into good/poor outcome groups based on postoperative modified Japanese Orthopedic Association (mJOA) scores. The datasets obtained from several scanners (an independent  scanner) for the training (testing) cohort were used for cross-validation (CV). Radiological models based on the intramedullary hyperintensity and compression ratio were constructed with 14 binary classifiers. Radiomic models based on 237 robust radiomic features were constructed with the same 14 binary classifiers in combination with 7 feature reduction methods, resulting in 98 models. The main outcome measures were the area under the receiver operating characteristic curve (AUROC) and accuracy. RESULTS: Forty-one (11) radiomic models were superior to random guessing during CV (testing), with significant increased AUROC and/or accuracy (P AUROC < .05 and/or P accuracy < .05). One radiological model performed better than random guessing during CV (P accuracy < .05). In the testing cohort, the linear SVM preprocessor + SVM, the best radiomic model (AUROC: 0.74 ± 0.08, accuracy: 0.73 ± 0.07), overperformed the best radiological model (P AUROC = .048). CONCLUSION: Radiomic features can predict postoperative spinal cord function in CSM patients. The linear SVM preprocessor + SVM has great application potential in building radiomic models.

18.
Acta Crystallogr F Struct Biol Commun ; 75(Pt 1): 67-72, 2019 Jan 01.
Artículo en Inglés | MEDLINE | ID: mdl-30605128

RESUMEN

Salicylic acid (SA) is an important phytohormone that is involved in the regulation of plant defence, growth and development. A large number of proteins have been shown to have the ability to interact with SA, and NPR4 has been demonstrated to be a receptor of SA that plays significant roles in the innate immune response of plants. In this study, Spodoptera frugiperda (Sf9) cells were used to express full-length AtNPR4 from Arabidopsis thaliana. To facilitate crystallization, T4 lysozyme (T4L) was added to the N-terminus of the AtNPR4 protein. The recombinant T4L-AtNPR4 protein was expressed, purified and crystallized using the sitting-drop and hanging-drop vapour-diffusion methods. The T4L-AtNPR4 crystals have symmetry consistent with space group C2, with unit-cell parameters a = 93.7, b = 85.8, c = 88.2 Å, ß = 90° and one molecule per asymmetric unit. The best crystal diffracted to a resolution of 2.75 Å. Structure determination is in progress.


Asunto(s)
Proteínas de Arabidopsis/química , Arabidopsis/química , Proteínas Recombinantes de Fusión/química , Secuencia de Aminoácidos , Animales , Arabidopsis/genética , Arabidopsis/inmunología , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/inmunología , Bacteriófago T4/química , Bacteriófago T4/genética , Bacteriófago T4/metabolismo , Baculoviridae/genética , Baculoviridae/metabolismo , Clonación Molecular , Cristalización , Cristalografía por Rayos X , Expresión Génica , Vectores Genéticos/química , Vectores Genéticos/metabolismo , Muramidasa/química , Muramidasa/genética , Muramidasa/metabolismo , Inmunidad de la Planta/genética , Isoformas de Proteínas/química , Isoformas de Proteínas/genética , Isoformas de Proteínas/inmunología , Proteínas Recombinantes de Fusión/genética , Proteínas Recombinantes de Fusión/inmunología , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Ácido Salicílico/química , Ácido Salicílico/inmunología , Ácido Salicílico/metabolismo , Alineación de Secuencia , Homología de Secuencia de Aminoácido , Células Sf9 , Spodoptera , Proteínas Virales/química , Proteínas Virales/genética , Proteínas Virales/metabolismo
19.
Mol Cell Endocrinol ; 375(1-2): 35-42, 2013 Aug 15.
Artículo en Inglés | MEDLINE | ID: mdl-23707792

RESUMEN

Microarray gene expression data were used to analyze the expression pattern of cyclin, cyclin-dependent kinase (CDKs) and cyclin-dependent kinase inhibitor (CDKIs) genes from human pancreatic islets with and without type 2 diabetes (T2D). Of the cyclin genes, CCNI was the most expressed. Data obtained from microarray and qRT-PCR showed higher expression of CCND1 in diabetic islets. Among the CDKs, CDK4, CDK8 and CDK9 were highly expressed, while CDK1 was expressed at low level. High expression of CDK18 was observed in diabetic islets. Of the CDKIs, CDKN1A expression was higher in diabetic islets in both microarray and qRT-PCR. Expression of CDKN1A, CDKN2A, CCNI2, CDK3 and CDK16 was correlated with age. Finally, eight SNPs in these genes were associated with T2D in the DIAGRAM database. Our data provide a comprehensive expression pattern of cell cycle genes in human islets. More human studies are required to confirm and reproduce animal studies.


Asunto(s)
Diabetes Mellitus Tipo 2/metabolismo , Genes cdc , Islotes Pancreáticos/metabolismo , Transcriptoma , Anciano , Envejecimiento , Estudios de Casos y Controles , Células Cultivadas , Proteínas Inhibidoras de las Quinasas Dependientes de la Ciclina/genética , Proteínas Inhibidoras de las Quinasas Dependientes de la Ciclina/metabolismo , Quinasas Ciclina-Dependientes/genética , Quinasas Ciclina-Dependientes/metabolismo , Ciclinas/genética , Ciclinas/metabolismo , Diabetes Mellitus Tipo 2/genética , Diabetes Mellitus Tipo 2/patología , Femenino , Perfilación de la Expresión Génica , Estudios de Asociación Genética , Predisposición Genética a la Enfermedad , Humanos , Insulina/metabolismo , Secreción de Insulina , Masculino , Persona de Mediana Edad , Análisis de Secuencia por Matrices de Oligonucleótidos , Polimorfismo de Nucleótido Simple
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