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Brain development is a highly complex process regulated by numerous genes at the molecular and cellular levels. Brain tissue exhibits serial microstructural changes during the development process. High-resolution diffusion magnetic resonance imaging (dMRI) affords a unique opportunity to probe these changes in the developing brain non-destructively. In this study, we acquired multi-shell dMRI datasets at 32 µm isotropic resolution to investigate the tissue microstructure alterations, which we believe to be the highest spatial resolution dMRI datasets obtained for postnatal mouse brains. We adapted the Allen Developing Mouse Brain Atlas (ADMBA) to integrate quantitative MRI metrics and spatial transcriptomics. Diffusion tensor imaging (DTI), diffusion kurtosis imaging (DKI), and neurite orientation dispersion and density imaging (NODDI) metrics were used to quantify brain development at different postnatal days. We demonstrated that the differential evolutions of fiber orientation distributions contribute to the distinct development patterns in white matter (WM) and gray matter (GM). Furthermore, the genes enriched in the nervous system that regulate brain structure and function were expressed in spatial correlation with age-matched dMRI. This study is the first one providing high-resolution dMRI, including DTI, DKI, and NODDI models, to trace mouse brain microstructural changes in WM and GM during postnatal development. This study also highlighted the genotype-phenotype correlation of spatial transcriptomics and dMRI, which may improve our understanding of brain microstructure changes at the molecular level.
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Encéfalo , Imagem de Difusão por Ressonância Magnética , Transcriptoma , Animais , Camundongos , Encéfalo/crescimento & desenvolvimento , Encéfalo/diagnóstico por imagem , Encéfalo/anatomia & histologia , Imagem de Difusão por Ressonância Magnética/métodos , Imagem de Tensor de Difusão/métodos , Substância Branca/crescimento & desenvolvimento , Substância Branca/diagnóstico por imagem , Substância Cinzenta/crescimento & desenvolvimento , Substância Cinzenta/diagnóstico por imagem , Substância Cinzenta/anatomia & histologia , Camundongos Endogâmicos C57BL , Masculino , FemininoRESUMO
INTRODUCTION: MODEL-AD (Model Organism Development and Evaluation for Late-Onset Alzheimer's Disease) is creating and distributing novel mouse models with humanized, clinically relevant genetic risk factors to capture the trajectory and progression of late-onset Alzheimer's disease (LOAD) more accurately. METHODS: We created the LOAD2 model by combining apolipoprotein E4 (APOE4), Trem2*R47H, and humanized amyloid-beta (Aß). Mice were subjected to a control diet or a high-fat/high-sugar diet (LOAD2+HFD). We assessed disease-relevant outcome measures in plasma and brain including neuroinflammation, Aß, neurodegeneration, neuroimaging, and multi-omics. RESULTS: By 18 months, LOAD2+HFD mice exhibited sex-specific neuron loss, elevated insoluble brain Aß42, increased plasma neurofilament light chain (NfL), and altered gene/protein expression related to lipid metabolism and synaptic function. Imaging showed reductions in brain volume and neurovascular uncoupling. Deficits in acquiring touchscreen-based cognitive tasks were observed. DISCUSSION: The comprehensive characterization of LOAD2+HFD mice reveals that this model is important for preclinical studies seeking to understand disease trajectory and progression of LOAD prior to or independent of amyloid plaques and tau tangles. HIGHLIGHTS: By 18 months, unlike control mice (e.g., LOAD2 mice fed a control diet, CD), LOAD2+HFD mice presented subtle but significant loss of neurons in the cortex, elevated levels of insoluble Ab42 in the brain, and increased plasma neurofilament light chain (NfL). Transcriptomics and proteomics showed changes in gene/proteins relating to a variety of disease-relevant processes including lipid metabolism and synaptic function. In vivo imaging revealed an age-dependent reduction in brain region volume (MRI) and neurovascular uncoupling (PET/CT). LOAD2+HFD mice also demonstrated deficits in acquisition of touchscreen-based cognitive tasks.
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Doença de Alzheimer , Peptídeos beta-Amiloides , Modelos Animais de Doenças , Proteínas tau , Animais , Doença de Alzheimer/patologia , Doença de Alzheimer/genética , Doença de Alzheimer/metabolismo , Camundongos , Peptídeos beta-Amiloides/metabolismo , Proteínas tau/metabolismo , Proteínas tau/genética , Camundongos Transgênicos , Encéfalo/patologia , Encéfalo/metabolismo , Sinapses/patologia , Sinapses/metabolismo , Masculino , Feminino , HumanosRESUMO
High-resolution magnetic resonance imaging (MRI) affords unique image contrasts to nondestructively probe the tissue microstructure; validation of MRI findings with conventional histology is essential to better understand the MRI contrasts. However, the dramatic difference in the spatial resolution and image contrast of these two techniques impedes accurate comparison between MRI metrics and traditional histology. To better validate various MRI metrics, we acquired whole mouse brain multigradient recalled-echo and multishell diffusion MRI datasets at 25-µm isotropic resolution. The recently developed Allen Mouse Brain Common Coordinate Framework (CCFv3) provides opportunities to integrate multimodal and multiscale datasets of the whole mouse brain in a common three-dimensional (3D) space. The T2*, quantitative susceptibility mapping, diffusion tensor imaging, and neurite orientation dispersion and density imaging parameters were compared with both serial two-photon tomography images and 3D Nissl staining images in the CCFv3 at the same spatial resolution. The correlation between MRI and Nissl staining strongly depends on different metrics and different regions of the brain. Integrating different imaging modalities to the same space may substantially improve our understanding of the complexity of the brain at different scales.
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Imagem de Tensor de Difusão , Imageamento por Ressonância Magnética , Animais , Camundongos , Imagem de Tensor de Difusão/métodos , Imagem de Difusão por Ressonância Magnética/métodos , Encéfalo/diagnóstico por imagem , Neuritos/patologiaRESUMO
Pregnancy intention refers to a women's thinking at the time she became aware that she was pregnant. It can be categorized as intended and unintended. Identifying pregnancy intentions during prenatal periods help to employ careful monitoring of pregnancy that is at high risk for mother and children's health outcomes. Unintended pregnancy is a contributing factor for maternal and infant mortality, which is still high in Nepal. Reproductive and family planning program should incorporate pregnancy intention domains in health education and counseling with priority to design program to address and reduce unintended pregnancy. This brief research examines the pregnancy intentions and its associated factors among married women so that it could identify the intentions of pregnancy and factors influencing unintended pregnancy and could be useful to improve and maintain the health and well-being of women, family, community, and nation.
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Intenção , Gravidez não Planejada , Gravidez , Criança , Feminino , Humanos , Nepal , Índia , Gravidez não Planejada/psicologia , CasamentoRESUMO
Diffusion magnetic resonance imaging has been widely used in both clinical and preclinical studies to characterize tissue microstructure and structural connectivity. The diffusion MRI protocol for the Human Connectome Project (HCP) has been developed and optimized to obtain high-quality, high-resolution diffusion MRI (dMRI) datasets. However, such efforts have not been fully explored in preclinical studies, especially for rodents. In this study, high quality dMRI datasets of mouse brains were acquired at 9.4T system from two vendors. In particular, we acquired a high-spatial resolution dMRI dataset (25 µm isotropic with 126 diffusion encoding directions), which we believe to be the highest spatial resolution yet obtained; and a high-angular resolution dMRI dataset (50 µm isotropic with 384 diffusion encoding directions), which we believe to be the highest angular resolution compared to the dMRI datasets at the microscopic resolution. We systematically investigated the effects of three important parameters that affect the final outcome of the connectome: b value (1000s/mm2 to 8000 s/mm2), angular resolution (10 to 126), and spatial resolution (25 µm to 200 µm). The stability of tractography and connectome increase with the angular resolution, where more than 50 angles is necessary to achieve consistent results. The connectome and quantitative parameters derived from graph theory exhibit a linear relationship to the b value (R2 > 0.99); a single-shell acquisition with b value of 3000 s/mm2 shows comparable results to the multi-shell high angular resolution dataset. The dice coefficient decreases and both false positive rate and false negative rate gradually increase with coarser spatial resolution. Our study provides guidelines and foundations for exploration of tradeoffs among acquisition parameters for the structural connectome in ex vivo mouse brain.
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Conectoma , Animais , Encéfalo/diagnóstico por imagem , Conectoma/métodos , Imagem de Difusão por Ressonância Magnética/métodos , Humanos , Processamento de Imagem Assistida por Computador/métodos , CamundongosRESUMO
BACKGROUND/AIMS: Alpha-lipoic acid (α-LA) has been demonstrated to be protective against cerebral ischemia injury. Herein, we investigate the neuroprotective effect and underlying mechanisms of α-LA. METHODS: In vivo study, α-LA was administered intravenously upon reperfusion of transient middle cerebral artery occlusion. Garcia score was used to evaluate neurologic recovery. Infarct volume was examined by TTC staining, and oxidative damage was evaluated by ELISA assay. In an in vitro study, neurons were pretreated with α-LA at different doses and then subjected to OGD. Lentiviral vectors were applied to knockdown nuclear factor-erythroid 2-related factor-2 (Nrf2) or heme oxygenase-1 (HO-1). Cell viability was measured using CCK8. Protein expression was evaluated using western blot, and immunofluorescence staining was assessed. RESULTS: α-LA significantly reduced the infarct volume, brain edema, and oxidative damage and promoted neurologic recovery in rats. Pretreatment of α-LA caused an obvious increase in cell viability and a decrease in intracellular reactive oxygen species. Western blot analyses and immunofluorescence staining demonstrated a distinct increase in Nrf2 and HO-1 protein expression. Conversely, knockdown of Nrf2 or HO-1 resulted in the down-regulation of HO-1 protein and inhibited the neuroprotective effect of α-LA. CONCLUSION: α-LA treatment is neuroprotective and promotes functional recovery after ischemic stroke by attenuating oxidative damage, which is partially mediated by the Nrf2/HO-1 pathway.
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Heme Oxigenase-1/metabolismo , Fator 2 Relacionado a NF-E2/metabolismo , Fármacos Neuroprotetores/farmacologia , Estresse Oxidativo/efeitos dos fármacos , Transdução de Sinais/efeitos dos fármacos , Ácido Tióctico/farmacologia , Animais , Encéfalo/efeitos dos fármacos , Encéfalo/metabolismo , Edema Encefálico/tratamento farmacológico , Edema Encefálico/etiologia , Edema Encefálico/patologia , Hipóxia Celular , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Modelos Animais de Doenças , Glutationa Peroxidase/metabolismo , Heme Oxigenase-1/antagonistas & inibidores , Heme Oxigenase-1/genética , Infarto da Artéria Cerebral Média , Masculino , Fator 2 Relacionado a NF-E2/antagonistas & inibidores , Fator 2 Relacionado a NF-E2/genética , Neurônios/citologia , Neurônios/efeitos dos fármacos , Neurônios/metabolismo , Fármacos Neuroprotetores/uso terapêutico , Ratos , Ratos Sprague-Dawley , Espécies Reativas de Oxigênio/metabolismo , Acidente Vascular Cerebral/tratamento farmacológico , Acidente Vascular Cerebral/patologia , Superóxido Dismutase/metabolismo , Ácido Tióctico/uso terapêuticoRESUMO
Layered two-dimensional (2D) semiconductors, such as MoS(2) and SnS(2), have been receiving intensive attention due to their technological importance for the next-generation electronic/photonic applications. We report a novel approach to the controlled synthesis of thin crystal arrays of SnS(2) at predefined locations on chip by chemical vapor deposition with seed engineering and have demonstrated their application as fast photodetectors with photocurrent response time â¼ 5 µs. This opens a pathway for the large-scale production of layered 2D semiconductor devices, important for applications in integrated nanoelectronic/photonic systems.
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BACKGROUND: Facial growth and development is necessary for proper orthodontic diagnosis and treatment planning. Growth of cranial base is linked to the overall growth of facial bones, especially the maxilla and mandible. Any change in the amount and direction of growth of the cranial base can have direct or indirect effects on the developing maxilla and mandible. Thus the aim of this study was to determine the linear and angular cranial base measurements in different skeletal malocclusion in Nepalese population. METHODS: Pretreatment lateral cephalograms of 225 patients aged between 17-30 years were collected. Linear measurements Sella-Nasion (S-N), Sella-Articulare (S-Ar), Articulare-Gonion (Ar-Go), Gonion-Gnathion (Go-Gn) and angular measurements Saddle angle (N-S-Ar), Articular angle (S-Ar-Go) and Gonial angle (Ar-Go-Gn) were measured. RESULTS: In angular measurements statistically significant differences were found in the saddle and gonial angles between class I, II, and III skeletal pattern. In linear measurements, anterior and posterior cranial base lengths were not significantly different among groups however, ramal height and mandibular body length were significantly different among groups with a P value < 0.05. CONCLUSIONS: Skeletal class III has a larger gonial angle, ramal height and mandibular length. Males have larger linear measurements and females have larger angular measurements.
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Má Oclusão , Adolescente , Adulto , Feminino , Humanos , Masculino , Adulto Jovem , Má Oclusão/diagnóstico por imagem , Nepal , Pacientes , Base do Crânio/diagnóstico por imagem , População do Sul da ÁsiaRESUMO
PURPOSE: Access to MRI in low- and middle-income countries (LMICs) remains among the poorest in the world. The lack of skilled MRI personnel exacerbates access gaps, reinforcing long-standing health disparities. The Scan With Me (SWiM) program aims to sustainably create a network of highly skilled MRI technologists in LMICs who will facilitate the transfer of MRI knowledge and skills to their peers and contribute to the implementation of highly valuable imaging protocols for effective clinical and research use. METHODS: The program introduces a case-based curriculum designed using a novel train-the-trainer approach, integrated with peer-collaborative learning to upskill practicing MRI technologists in LMICs. The 6-week curriculum uses the teach-try-use approach, which combines self-paced didactic lectures covering the basics of MR image acquisition (teach) with hands-on expert-guided scanning experience (try) and the implementation of protocols tailored to provide the best possible images on their infrastructures (use). Each program includes research translation skills training using an established advanced MRI technique relevant to LMICs. A pilot program focused on cardiac MRI (CMR) was conducted to assess the program's curriculum, delivery, and evaluation methods. RESULTS: Forty-three MRI technologists from 16 LMICs participated in the pilot CMR program and, over the course of the training, implemented optimized CMR protocols that reduced acquisition times while improving image quality. The training resources and scanner-specific standardized protocols are published openly for public use in an online repository. In general, at the end of the program, learners reported considerable improvements in CMR knowledge and skills. All respondents to the program evaluation survey agreed to recommend the program to their colleagues, while 87% indicated interest in returning to help train others. CONCLUSIONS: The SWiM program is the first master class in MRI acquisition for practicing imaging technologists in LMICs. The program holds the potential to help reduce disparities in MRI expertise and access. The support of the MRI community, imaging societies, and funding agencies will increase its reach and further its impact in democratizing MRI.
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Currículo , Países em Desenvolvimento , Imageamento por Ressonância Magnética , Humanos , Avaliação de Programas e Projetos de Saúde , Competência Clínica , Feminino , Masculino , Tecnologia Radiológica/educação , Projetos PilotoRESUMO
A flexible piezoresistive sensor was developed as an accelerometer based on Graphene/PVDF nanocomposite to detect low-frequency and low amplitude vibration of industrial machines, which may be caused due to misalignment, looseness of fasteners, or eccentric rotation. The sensor was structured as a cantilever beam with the proof mass at the free end. The vibration caused the proof mass to accelerate up and down, which was converted into an electrical signal. The output was recorded as the change in resistance (response percentage) with respect to the acceleration. It was found that this accelerometer has a capability of detecting acceleration up to 8 gpk-pk in the frequency range of 20 Hz to 80 Hz. The developed accelerometer has the potential to represent an alternative to the existing accelerometers due to its compactness, simplicity, and higher sensitivity for low frequency and low amplitude applications.
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In this study, the process for tuning the electrical properties of graphene/polyvinylidene fluoride (Gr/PVDF) nanocomposite films by a thermal annealing process is explored. The surface morphology and microstructure of the nanocomposite were characterized. The effect of temperature on the electrical conductivity was investigated by heating and cooling the sample from the room temperature up to 150 °C. The effect of annealing on the electrical conductivity was recorded as a function of annealing temperature. A Hall effect measurement was conducted as a function of annealing temperatures to obtain Hall voltage (V H), carrier mobility (µH), carrier concentration (n H), Hall coefficient (R H), resistivity, and carrier conductivity type (n or p). It was found that the films annealed at 150 °C exhibited the best electrical conductivity of Gr/PVDF films. This study may provide an insight into the development and utilization of Gr/PVDF films in future electronics and the potential applications in various sectors such as aerospace, automotive, and biomedical industries.
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In this paper, a knittle pressure sensor was designed and fabricated by coating graphene/Polyvinylidene Fluoride nanocomposite on the knitted polyester substrate. The coating was carried out by a dip-coating method in a nanocomposite solution. The microstructure, surface properties and electrical properties of coated layers were investigated. The sensors were tested under the application of different pressures, and the corresponding sensor signals were analyzed in terms of resistance change. It was observed that the change in resistance was 55% kPa-1 with a sensitivity limit of 0.25 kPa. The sensor model was created and simulated using COMSOL Multiphysics software, and the model data were favorably compared with the experimental results. This investigation suggests that graphene-based nanocomposites can be used in knittle pressure sensor applications.
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INTRODUCTION: MODEL-AD is creating and distributing novel mouse models with humanized, clinically relevant genetic risk factors to more accurately mimic LOAD than commonly used transgenic models. METHODS: We created the LOAD2 model by combining APOE4, Trem2*R47H, and humanized amyloid-beta. Mice aged up to 24 months were subjected to either a control diet or a high-fat/high-sugar diet (LOAD2+HFD) from two months of age. We assessed disease-relevant outcomes, including in vivo imaging, biomarkers, multi-omics, neuropathology, and behavior. RESULTS: By 18 months, LOAD2+HFD mice exhibited cortical neuron loss, elevated insoluble brain Aß42, increased plasma NfL, and altered gene/protein expression related to lipid metabolism and synaptic function. In vivo imaging showed age-dependent reductions in brain region volume and neurovascular uncoupling. LOAD2+HFD mice also displayed deficits in acquiring touchscreen-based cognitive tasks. DISCUSSION: Collectively the comprehensive characterization of LOAD2+HFD mice reveal this model as important for preclinical studies that target features of LOAD independent of amyloid and tau.
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Introduction: New concepts and methods have been developed in orthodontics with patients' increased concern on esthetics. Among the various parameters of smile, smile type, smile arc, and smile symmetry are essential for a beautiful smile. The objective of this study was to find out the prevalence of average type in posed smiles of individuals visiting the department of orthodontics. Methods: This descriptive cross-sectional study was conducted from 1st April 2021 to 30th June 2021 at a tertiary care hospital. Ethical clearance was obtained from the Institutional Review Committee (Reference number: 1, CH No. 30, 2077/2078). A convenience sampling technique was used to collect a total of 413 samples of posed smile photographs. Data was collected and analysed using Microsoft Excel 2013. Point estimate at 95% Confidence Interval was calculated along with frequency and percentage. Results: Among 413 individuals, the average type of smile was found in 193 (46.73%) (42.12-51.74 at 95% Confidence Interval). Out of 87 average smile type males, most of them 51 (58.62%) had non consonant smile arcs and 47 (54.02%) had asymmetric type smiles. On the contrary, the majority of females 76 (71.70%) had a consonant arc smile while 63 (59.43%) had an asymmetric smile. Conclusions: The prevalence of the average type of smile was higher in our study as in other published literatures. Keywords: dental esthetics; dental photography; orthodontics; smiling.
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Ortodontia , Sorriso , Estudos Transversais , Estética Dentária , Feminino , Humanos , Masculino , Centros de Atenção TerciáriaRESUMO
In recent years, flexible and stretchable sensors have been a subject of intensive research to replace the traditional sensors made up of rigid metals and semiconductors. In this paper, a piezoresistive airflow sensor was designed and tested to measure the speed of air inside a pipe. Graphene/polyvinylidene fluoride nanocomposite films were prepared using a solvent-cast technique on a flexible polyethylene substrate as a piezoresistive material. Three different solutions were studied as a function of graphene concentration. The microstructure of the nanocomposite was characterized by X-ray diffraction, scanning electron microscopy, and optical microscopy. The effect of temperature on electrical conductivity was investigated by heating and cooling the sample between the room temperature and 150 °C. The stretchability of the nanocomposite film was studied with a tensile test, and the same procedure was employed to determine the breakdown point of the electrical conductivity. The sensor response was measured in terms of the resistance change caused by air pressure and found to increase with the concentration of graphene in the composite. The sensing characteristics were simulated using the COMSOL Multiphysics software, and the modeled data were compared favorably with the experimental result. The sensitivity of the sensor was found to be 1.21% kPa-1 in the range of 0-2.7 kPa. This piezoelectric sensor possesses unique characteristics such as being lightweight, flexible, and exhibiting fast response; hence, it can have potential applications in various sectors such as ventilators, commercial HVAC, and automotive industries.
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Purpose: To evaluate the age-dependent microstructure changes in 5xFAD mice using high-resolution diffusion tensor imaging (DTI). Methods: The 5xFAD mice at 4, 7.5, and 12 months and the wild-type controls at 4 months were scanned at 9.4T using a 3D echo-planar imaging (EPI) pulse sequence with the isotropic spatial resolution of 100 µm. The b-value was 3000 s/mm2 for all the diffusion MRI scans. The samples were also acquired with a gradient echo pulse sequence at 50 µm isotropic resolution. The microstructure changes were quantified with DTI metrics, including fractional anisotropy (FA) and mean diffusivity (MD). The conventional histology was performed to validate with MRI findings. Results: The FA values (p = 0.028) showed significant differences in the cortex between wild-type (WT) and 5xFAD mice at 4 months, while hippocampus, anterior commissure, corpus callosum, and fornix showed no significant differences for either FA and MD. FA values of 5xFAD mice gradually decreased in cortex (0.140 ± 0.007 at 4 months, 0.132 ± 0.008 at 7.5 months, 0.126 ± 0.013 at 12 months) and fornix (0.140 ± 0.007 at 4 months, 0.132 ± 0.008 at 7.5 months, 0.126 ± 0.013 at 12 months) with aging. Both FA (p = 0.029) and MD (p = 0.037) demonstrated significant differences in corpus callosum between 4 and 12 months age old. FA and MD were not significantly different in the hippocampus or anterior commissure. The age-dependent microstructure alterations were better captured by FA when compared to MD. Conclusion: FA showed higher sensitivity to monitor amyloid deposition in 5xFAD mice. DTI may be utilized as a sensitive biomarker to monitor beta-amyloid progression for preclinical studies.
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PURPOSE: To evaluate the magic angle effect on diffusion tensor imaging (DTI) measurements in rat ligaments and mouse brains. METHODS: Three rat knee joints and three mouse brains were scanned at 9.4 T using a modified 3D diffusion-weighted spin echo pulse sequence with the isotropic spatial resolution of 45 µm. The b value was 1000 s/mm2 for rat knee and 4000 s/mm2 for mouse brain. DTI model was used to investigate the quantitative metrics at different orientations with respect to the main magnetic field. The collagen fiber structure of the ligament was validated with polarized light microscopy (PLM) imaging. RESULTS: The signal intensity, signal-to-noise ratio (SNR), and DTI metrics in the ligament were strongly dependent on the collagen fiber orientation with respect to the main magnetic field from both simulation and actual MRI scans. The variation of fractional anisotropy (FA) was about ~32%, and the variation of mean diffusivity (MD) was ~11%. These findings were further validated with the numerical simulation at different SNRs (~10.0 to 86.0). Compared to the ligament, the DTI metrics showed little orientation dependence in mouse brains. CONCLUSION: Magic angle effect plays an important role in DTI measurements in the highly ordered collagen-rich tissues, while MD showed less orientation dependence than FA.
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Encéfalo , Imagem de Tensor de Difusão , Animais , Anisotropia , Encéfalo/diagnóstico por imagem , Colágeno , Imagem de Tensor de Difusão/métodos , Ligamentos , Camundongos , RatosRESUMO
[This corrects the article DOI: 10.3389/fnins.2022.964654.].
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Many drugs that show potential in animal models of glioblastoma (GBM) fail to translate to the clinic, contributing to a paucity of new therapeutic options. In addition, animal model development often includes histologic assessment, but multiparametric/multimodality imaging is rarely included despite increasing utilization in patient cancer management. This study developed an intracranial recurrent, drug-resistant, human-derived glioblastoma tumor in Sprague-Dawley Rag2-Rag2 tm1Hera knockout rat and was characterized both histologically and using multiparametric/multimodality neuroimaging. Hybrid 18F-fluoroethyltyrosine positron emission tomography and magnetic resonance imaging, including chemical exchange saturation transfer (18F-FET PET/CEST MRI), was performed for full tumor viability determination and characterization. Histological analysis demonstrated human-like GBM features of the intracranially implanted tumor, with rapid tumor cell proliferation (Ki67 positivity: 30.5 ± 7.8%) and neovascular heterogeneity (von Willebrand factor VIII:1.8 to 5.0% positivity). Early serial MRI followed by simultaneous 18F-FET PET/CEST MRI demonstrated consistent, predictable tumor growth, with exponential tumor growth most evident between days 35 and 49 post-implantation. In a second, larger cohort of rats, 18F-FET PET/CEST MRI was performed in mature tumors (day 49 post-implantation) for biomarker determination, followed by evaluation of single and combination therapy as part of the model development and validation. The mean percentage of the injected dose per mL of 18F-FET PET correlated with the mean %CEST (r = 0.67, P < 0.05), but there was also a qualitative difference in hot spot location within the tumor, indicating complementary information regarding the tumor cell demand for amino acids and tumor intracellular mobile phase protein levels. Finally, the use of this glioblastoma animal model for therapy assessment was validated by its increased overall survival after treatment with combination therapy (temozolomide and idasanutlin) (P < 0.001). Our findings hold promise for a more accurate tumor viability determination and novel therapy assessment in vivo in a recently developed, reproducible, intracranial, PDX GBM.
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INTRODUCTION: Orthodontic treatment may affect the size and position of oropharyngeal structures altering the airway dimension. Airway dimension is considered as one of the parameter of orthodontic diagnosis and treatment planning. Narrow airway passage is associated with sleep disordered breathing. This aims to study about the measurement of upper pharyngeal airway dimension of young Nepalese adults visiting orthodontic department of a dental college. METHODS: This descriptive cross-sectional study conducted at Department of Orthodontics, Peoples Dental College and Hospital, Kathmandu. Data was collected from 8th December 2020 to 28th February 2021. Ethical clearance (Reference number. 1, CH100 06, 2077/2076) was taken from Institutional Review Committee of Peoples Dental College and Hospital, Kathmandu, Nepal. Convenient Sampling technique was done. Data was collected and analysis was done using Statistical Packageof Social Sciences 16. RESULTS: Mean upper pharyngeal airway dimension was 11.40±1.84mm and 11.68±1.96mm for male and female respectively. Upper pharyngeal airway dimension was found to be almost similar for male and female. CONCLUSIONS: Gender diversity regarding upper pharyngeal airway dimesnion was not observed in this study while other studies also revealed similarities in upper pharyngeal airway dimension between male and female, inspite of larger craniofacial dimension in males than females.