40 research outputs found
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Improving Patch-Based Convolutional Neural Networks for MRI Brain Tumor Segmentation by Leveraging Location Information.
The manual brain tumor annotation process is time consuming and resource consuming, therefore, an automated and accurate brain tumor segmentation tool is greatly in demand. In this paper, we introduce a novel method to integrate location information with the state-of-the-art patch-based neural networks for brain tumor segmentation. This is motivated by the observation that lesions are not uniformly distributed across different brain parcellation regions and that a locality-sensitive segmentation is likely to obtain better segmentation accuracy. Toward this, we use an existing brain parcellation atlas in the Montreal Neurological Institute (MNI) space and map this atlas to the individual subject data. This mapped atlas in the subject data space is integrated with structural Magnetic Resonance (MR) imaging data, and patch-based neural networks, including 3D U-Net and DeepMedic, are trained to classify the different brain lesions. Multiple state-of-the-art neural networks are trained and integrated with XGBoost fusion in the proposed two-level ensemble method. The first level reduces the uncertainty of the same type of models with different seed initializations, and the second level leverages the advantages of different types of neural network models. The proposed location information fusion method improves the segmentation performance of state-of-the-art networks including 3D U-Net and DeepMedic. Our proposed ensemble also achieves better segmentation performance compared to the state-of-the-art networks in BraTS 2017 and rivals state-of-the-art networks in BraTS 2018. Detailed results are provided on the public multimodal brain tumor segmentation (BraTS) benchmarks
Studies of solute-solvent interactions and miceller behaviour of complexes of copper (II) palmitate with substituted phenylthiourea and 2-amino benzothiazole in methanol-benzene mixture
In this work, synthesis of copper (II) surfactants followed by the complexation of each other with the molar ratio of 1:2 dissolving in ethanol have been reported. The purity of the resulting complexes of the general formula- CP(PTU )T , CP(BTA)T was checked by thin layer chromatography and characterized on the basis of elemental analysis. Their spectral studies are also included and data suggest that Cu (II) phenylthiourea mixed system binds through the donor ability of nitrogen to transition metal. The magnetic moment studies suggest the dimeric nature of the complexes. IR, NMR, ESR spectral details confirm that complexation has taken place successfully and dada suggest that the complexes possess elongated octahedral geometry. Density, Molar Volume, Apparent Molar Volume of these complexes was investigated in non-aqueous solvent at various concentrations by Springel Pyknometer to understand the nature, critical micelle concentration and micelle characteristics of the complexes. Overall, the CMC values were found to be decreased with increasing average molecular weight of soap complex. The solute - solute interactions were found to be greater before CMC whereas solute-solvent interactions were found greater after CMC
Cellulose an ageless renewable green nanomaterial for medical applications: an overview of ionic liquids in extraction, separation and dissolution of cellulose
Cellulose is a renewable natural fiber, which has gained enormous and significant research interest and evolved as the prime and promising candidate for replacing synthetic fibers. The various sources of cellulose, which is one of the world's most ubiquitous and renewable biopolymer resources, include trees, plants, tunicate and bacteria. The renewable biomaterial in the form of nanocellulose and its composites have been included in this review having the broad range of medical applications, viz.; tissue engineering, cardiovascular surgery, dental, pharmaceuticals, veterinary, adhesion barriers and skin therapy. These grafts are being fabricated from biodegradable materials. Bacterial cellulose is also an emerging renewable biomaterial with immense potential in biomedical field. The fabrication methods, characteristic properties and various overwhelming applications of cellulosic composites are explicitly elucidated in this review. The crux of this review is to exhibit the latest state of art, development in the field of cellulosic nanocomposite science and technology research and their applications towards biomedical field. Among the fourteen principle of green chemistry the two key principles i.e. using environmentally preferable solvents and bio-renewable feed-stocks covers in dissolution of cellulose in ionic liquids (ILs). In addition, this review covers about the comprehensive extraction and dissolution of cellulose and nanocellulose using ILs.publishe
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Corrigendum: Improving Patch-Based Convolutional Neural Networks for MRI Brain Tumor Segmentation by Leveraging Location Information.
[This corrects the article DOI: 10.3389/fnins.2019.01449.]
Fine particulate matter in the tropical environment: monsoonal effects, source apportionment, and health risk assessment
The health implications of PM2:5 in the tropical
region of Southeast Asia (SEA) are significant as PM2:5
can pose serious health concerns. PM2:5 concentration and
sources here are strongly influenced by changes in the monsoon
regime from the south-west quadrant to the north-east
quadrant in the region. In this work, PM2:5 samples were
collected at a semi-urban area using a high-volume air sampler
at different seasons on 24 h basis. Analysis of trace elements
and water-soluble ions was performed using inductively
coupled plasma mass spectroscopy (ICP-MS) and ion
chromatography (IC), respectively. Apportionment analysis
of PM2:5 was carried out using the United States Environmental
Protection Agency (US EPA) positive matrix factorization
(PMF) 5.0 and a mass closure model. We quantitatively
characterized the health risks posed to human populations
through the inhalation of selected heavy metals in
PM2:5. 48% of the samples collected exceeded the World
Health Organization (WHO) 24 h PM2:5 guideline but only
19% of the samples exceeded 24 h US EPA National Ambient
Air Quality Standard (NAAQS). The PM2:5 concentration
was slightly higher during the north-east monsoon compared
to south-west monsoon. The main trace metals identified
were As, Pb, Cd, Ni, Mn, V, and Cr while the main ions
were SO
Kajian jati diri kakitangan dalam organisasi Universiti Kebangsaan Malaysia
Isu jati diri merupakan aspek penting dalam organisasi untuk memupuk penglibatan dan rasa
setia individu terhadap organisasi. Berlandaskan konsep jati diri, kajian ini bertujuan untuk
mengetahui konsep jati diri dalam kalangan warga Universiti Kebangsaan Malaysia (UKM),
di mana hasil kajian ini akan dapat mengenal pasti perkara yang perlu dilakukan untuk
memupuk perasaan jati diri terhadap UKM. Teori yang mendasari kajian ini ialah teori
Identiti Sosial (Turner & Tajfel, 1979). Kajian ini mensasarkan penyertaan warga kerja di
peringkat pengurusan tertinggi dan profesional, ahli-ahli akademik dan kakitangan pelaksana.
Instrumen kajian ialah sesi tembual. Soalan termubual dibangunkan berdasarkan tiga
konstruk jati diri, iaitu setia, sayang dan bangga. Analisis data menunjukkan terdapat
pemahaman jati diri yang berbeza dalam kalangan kakitangan UKM di mana ianya
bergantung kepada jawatan kumpulan sasar tersebut. Walaupun terdapat perbezaan di mana
segilintir responden bersedia untuk meninggalkan UKM sekiranya mereka mendapat tawaran
yang lebih baik dari organisi luar, secara umum kakitangan UKM mempunyai semangat
setia, sayang dan bangga yang agak tinggi dan positif terhadap UKM. Kajian lanjut pada
masa hadapan boleh dilakukan bagi merungkai permasalahan yang timbul dalam kalangan
warga UKM agar usaha memperkukuh jati diri UKM dapat dilaksanakan dengan lebih
mantap dan komprehensif
Left atrial function in heart failure with preserved ejection fraction:a systematic review and meta-analysis
Aims Left atrial (LA) mechanical function may play a significant role in the development and progression of heart failure with preserved ejection fraction (HFpEF). We performed a systematic review and meta-analysis to evaluate association of impaired LA function with outcomes in HFpEF. Methods and results Multiple databases were searched for original studies measuring different phases of LA function in HFpEF patients. Comparative LA function between HFpEF patients and healthy controls was assessed by pooling weighted mean differences (WMD). Adjusted hazard ratios (HRs) with 95% confidence intervals were pooled to evaluate the prognostic utility of LA function. Twenty-two studies (2 trials, 20 observational) comprising 1974 HFpEF patients and 751 healthy controls were included. HFpEF patients had decreased LA reservoir [WMD = -12.21% (-15.47, -8.95); P <0.001], LA conduit [WMD = -5.68% (-8.56, -2.79); P <0.001], and pump [WMD = -11.07% (-14.81, -7.34); P <0.001] emptying fractions compared with controls. LA reservoir [WMD = -13.38% (-16.07, -10.68); P <0.001], conduit [WMD = -4.09% (-6.77, -1.42); P = 0.003], and pump [WMD = -3.53% (-4.47, -2.59); P <0.001] strains were also significantly lower in HFpEF patients. Decreased LA reservoir strain [HR 1.24 (1.02, 1.50); P = 0.03] was significantly associated with risk of composite all-cause mortality or heart failure hospitalization. Conclusions Impaired LA function appears to have diagnostic and prognostic value in HFpEF, but whether indices of LA function truly refine discrimination for diagnosis or prognosis remains to be fully determined. Larger studies are needed to better evaluate associations between LA function and clinical outcomes and the role of LA function as a target for novel HFpEF therapies
Freedom of expression, accountability and development in the Arab region
Mechanisms for ensuring government transparency and accountability have yet to become established in the Arab region, where oil rents and security rents have
traditionally enabled governments to provide jobs and services without having to rely heavily, if at all, on raising revenue through personal income tax on citizens. Yet
various forms of resource mobilisation, which will be needed in future, are likely to require a greater degree of accountability from those responsible for such mobilisation. This paper considers whether a move in this direction is under way. It reviews government approaches to freedom of expression in the media and among non-governmental organisations. It notes changes that have taken place in this sphere since the start of the 1990s, not all of them positive, and concludes that many more
steps remain to be taken if media organisations and NGOs are to exert pressure for accountability on behalf of citizens, and especially the disadvantaged
Characterisation of particle mass and number concentration on the east coast of the Malaysian Peninsula during the northeast monsoon
Particle mass concentrations (PM10, PM2.5 and PM1) and particle number concentration ((PNC); 0.27 μm ≤ Dp ≤ 34.00 μm) were measured in the tropical coastal environment of Bachok, Kelantan on the Malaysian Peninsula bordering the southern edge of the South China Sea. Statistical methods were applied on a three-month hourly data set (9th January to 24th March 2014) to study the influence of north-easterly winds on the patterns of particle mass and PNC size distributions. The 24-h concentrations of particle mass obtained in this study were below the standard values detailed by the Recommended Malaysian Air Quality Guideline (RMAQG), United States Environmental Protection Agency (US EPA) and European Union (EU) except for PM2.5, which recorded a 24-h average of 30 ± 18 μg m-3 and exceeded the World Health Organisation (WHO) threshold value (25 μg m-3). Principal component analysis (PCA) revealed that PNC with smaller diameter sizes (0.27-4.50 μm) showed a stronger influence, accounting for 57.6% of the variability in PNC data set. Concentrations of both particle mass and PNC increased steadily in the morning with a distinct peak observed at around 8.00 h, related to a combination of dispersion of accumulated particles overnight and local traffic. In addition to local anthropogenic, agricultural burning and forest fire activities, long-range transport also affects the study area. Hotspot and backward wind trajectory observations illustrated that the biomass burning episode (around February-March) significantly influenced PNC. Meteorological parameters influenced smaller size particles (i.e. PM1 and Dp (0.27-0.43 μm)) the most