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Kagome-lattice crystal is crucial in quantum materials research, exhibiting unique transport properties due to its rich band structure and the presence of nodal lines and rings. Here, we investigate the electronic transport properties and perform first-principles calculations for Ni3In2Se2kagome topological semimetal. First-principles calculations of the band structure without the inclusion of spin-orbit coupling (SOC) shows that three bands are crossing the Fermi level (EF), indicating the semi-metallic nature. With SOC, the band structure reveals a gap opening of the order of 10 meV.Z2index calculations suggest the topologically nontrivial natures (ν0;ν1ν2ν3) = (1;111) both without and with SOC. Our detailed calculations also indicate six endless Dirac nodal lines and two nodal rings with aπ-Berry phase in the absence of SOC. The temperature-dependent resistivity is dominated by two scattering mechanisms:s-dinterband scattering occurs below 50 K, while electron-phonon (e-p) scattering is observed above 50 K. The magnetoresistance (MR) curve aligns with the theory of extended Kohler's rule, suggesting multiple scattering origins and temperature-dependent carrier densities. A maximum MR of 120% at 2 K and 9 T, with a maximum estimated mobility of approximately 3000 cm2V-1s-1are observed. Ni3In2Se2is an electron-hole compensated topological semimetal, as we have carrier density of electron (ne) and hole (nh) arene≈nh, estimated from Hall effect data fitted to a two-band model. Consequently, there is an increase in the mobility of electrons and holes, leading to a higher carrier mobility and a comparatively higher MR. The quantum interference effect leading to the two dimensional (2D) weak antilocalization effect (-σxxâln(B)) manifests as the diffusion of nodal line fermions in the 2D poloidal plane and the associated encircling Berry flux of nodal-line fermions.
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OBJECTIVE: To develop and validate e-portfolios for undergraduate medical students in the subject of Pediatrics. METHOD: A descriptive study was conducted among the second year medical undergraduate students. A core committee validated the e-portfolio created on the Google platform. The students were sensitized, trained on the platform, and encouraged to innovate by designing the e-portfolios themselves, and record their clinical experiences under the mentorship of faculty. The feedback was collected using a validated student and faculty questionnaire with closed and open ended questions. Satisfaction index was calculated based on the responses to closed ended questions using Likert scale. Open ended questions were analyzed using thematic approach. RESULTS: The study enrolled 34 students and 12 faculty members. Students recorded a high satisfaction index on their experience to be interesting (97%), well structured (85%), user-friendly (82%), and on being able to archive their clinical experiences (100%). Faculty members recorded a high satisfaction index (100%) in students' ability to record their clinical knowledge and reflect on their learning and innovation; all were motivated to use e-portfolios in their specialty. The thematic analysis highlighted student satisfaction with accessibility and organized record-keeping, while faculty praised e-portfolios for nurturing creativity and aiding memory retention. Concerns included resource intensiveness, design prioritization, and privacy issues. CONCLUSION: E-portfolios are rated as promising tools to record comprehensive clinical experience in pediatric by undergraduate students and faculty. Addressing identified challenges will further optimize their adoption in medical curricula, facilitating informed integration decisions.
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Educação de Graduação em Medicina , Pediatria , Estudantes de Medicina , Humanos , Pediatria/educação , Educação de Graduação em Medicina/métodos , Estudantes de Medicina/estatística & dados numéricos , Inquéritos e Questionários , Avaliação Educacional/métodos , InternetRESUMO
A 14-month-old female child was brought to us by her parents with the complaint of progressive shortening of her right lower limb since birth. Born to non-consanguineous parents from a poor socioeconomic background, her birth and antenatal history were uneventful. Physical examination revealed no facial dysmorphism; however, her right thigh was short and bulky, and there were restrictions in hip, knee, and ankle movements. The pediatric evaluation showed normal growth and development. X-rays confirmed proximal femoral focal deficiency (PFFD) of the right lower limb. After extensive parental counseling regarding the condition, potential interventions, and outcomes, the parents opted for prosthetic management due to concerns about surgical costs, risks, and cosmetic outcomes. A custom-made extension prosthesis was prepared for the limb and was fit. At a follow-up of one year, the child exhibited a normal gait pattern with stable hip, knee, and ankle motion, and the parents expressed satisfaction with the prosthetic management, preferring it over surgical intervention for the time being.
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OBJECTIVE: This study aims to study the efficacy of exchange transfusion in complicated malaria with hyperparasitaemia. METHOD: This is a retrospective case-control study conducted in a tertiary care referral hospital in northeastern India. A retrospective chart review was done, and 34 children with hyperparasitaemia were identified. Of these, 16 children received only antimalarial chemotherapy, and 18 received adjunct exchange blood transfusion (EBT). The data was analyzed for survival benefit as the main outcome measure. RESULTS: The subjects in each of the groups were comparable in terms of age, sex distribution, and mean haemoglobin at presentation. The patients treated with EBT were more ill than those who did not receive EBT; they met a greater number of WHO criteria for severe malaria (2.94 ± 1.16 vs. 1.81 ± 0.83; p=0.002) and had higher levels of parasitaemia (23.96 ± 17.55 vs. 16.14 ± 6.89; p=0.0007). The mean volume exchanged was 44.88 ± 20.49 ml/kg, against a target of 70 ml/kg due to the unavailability of fresh, compatible whole blood. There was no difference in mortality in the exchange transfusion group compared to the chemotherapy alone group (22.22% vs. 31.25%; p=0.83). CONCLUSIONS: In resource-limited areas, lower volumes of fresh whole blood for exchange transfusion can reduce hyperparasitaemia to a significant degree, and this may give some mortality benefit in very sick cases. Artesunate, by virtue of its rapid action, is capable of reducing hyperparasitaemia and may question the very place of blood transfusion in complicated malaria. It may also be worthwhile to accumulate more data comparing EBT against artesunate instead of quinine.
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A comprehensive study of structural and magnetotransport properties of pristine Bi2-xSbxTe3-ySey(BSTS) single crystals and doped with Zn (BSTS:Zn) and Ga (BSTS:Ga) are presented here. Magnetic field dependent Hall resistivities of the single crystals indicate that the holes are the majority carriers. The field dependent resistivity curves at different temperatures of the crystals display cusp-like characteristics at low magnetic fields, attributed to two-dimensional (2D) weak antilocalization (WAL) effect. We fit the observed low-field WAL effects at low temperatures using 2D and three-dimensional (3D) Hikami-Larkin-Nagaoka (HLN) equations. The 2D HLN equation fits the data more closely than the 3D HLN equation, indicating a 2D nature. The 2D HLN equation fit to the low field WAL effects at various temperatures reveal a phase coherence length (lφ) that decreases as temperature increases. The variation oflφwith temperature followsT-0.41power law for BSTS:Zn, suggesting that the dominant dephasing mechanism is a 2D electron-electron (e-e) interactions. For pristine BSTS and BSTS:Ga,lφ(T) is described by considering a coexistence of 2De-eand electron-phonon (e-p) interactions in the single crystals. The temperature variation of the longitudinal resistance in BSTS:Ga is described by 3D Mott variable range hoping model. In contrast, the transport mechanisms of both pristine BSTS and BSTS:Zn are described by a combination of 2D WAL/EEI models and 3D WAL.
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BACKGROUND: Scaphoid fracture is most often missed and mismanaged leading to scaphoid nonunion with or without avascular necrosis. When avascular necrosis of the proximal pole is confirmed with intraoperative evaluation, conventional bone graft is not enough. The treatment modalities are evolving day by day. The current trend is vascular bone grafting, which has shown good outcomes in terms of union and wrist function. METHODS: Fifty patients with nonunion fracture of the scaphoid were treated with vascularized pedicle bone graft from the dorsum of the distal radius using the 1st and 2nd intercompartmental supraretinacular artery, from 2014 to 2022. Preoperative and postoperative clinical evaluation included pain, range of motion, grip strength, and satisfaction. The average follow-up period was 12 months. RESULTS: Among 18 patients, 14 were clinically improved after a mean follow-up period of eight weeks. Thirteen patients reported the absence of any discomfort, three patients reported slight discomfort after hard work, and two patients reported pain with light work. The wrist range of motion improved significantly, and the hand grip strength also improved. According to the modified Mayo wrist scoring chart, clinical results were rated as excellent in 24 cases, good in 19 cases, and poor in four cases. CONCLUSION: 1,2 intercompartmental supraretinacular artery (1,2 ICSRA) is superficial to the extensor retinaculum and is a proper pedicle of vascularized bone graft due to the ease of visibility and dissection. The functional results and union rates were satisfactory in our study.
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Introduction The mucosa in the cardiac region of the stomach has been less understood. Cardiac mucosa (CM) with less parietal and oxyntic cells has been defined as a normal mucosa. Studies have shown that CM can be the result of occult reflux. Oxyntic mucosa (OM) is normal, and it changes to CM with age. In advancing age, it is more common to find CM instead of OM and oxyntocardiac mucosa (OCM). This study is an attempt to examine the distribution of the three different types of mucosa in various age groups. Materials and methods The study was conducted in the Department of Anatomy and Department of Forensic Medicine and Toxicology of Gauhati Medical College, Guwahati, Assam, India, from 2017 to 2019. Once the stomach was opened, histological specimens were prepared, and the type of mucosa was observed and recorded. Then, the distribution of the types of mucosa in various age groups was analyzed. Results The distribution of mucosa varies significantly across different age groups, and CM increases with age. Conclusion Our present study suggests that CM frequency increases with age. This is in accordance with studies that suggest that CM is a result of occult reflux with age. This observation creates a scope to revise the approaches for upper gastrointestinal (GI) endoscopy.
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The first use of sulfoxonium ylides for the synthesis of α-ketoamides is described via a Ru(II)-catalyzed amidation reaction with amines. The same Ru(II)-catalyzed reaction of sulfoxonium ylides with 2-phenylindoles provided indolo[2,1-a]isoquinolines instead of α-ketoamides.
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Low Performing Pixel (LPP)/bad pixel in CT detectors cause ring and streaks artifacts, structured non-uniformities and deterioration of the image quality. These artifacts make the image unusable for diagnostic purposes. A missing/defective detector pixel translates to a channel missing across all views in sinogram domain and its effect gets spill over entire image in reconstruction domain as artifacts. Most of the existing ring and streak removal algorithms perform correction only in the reconstructed image domain. In this work, we propose a supervised deep learning algorithm that operates in sinogram domain to remove distortions cause by the LPP. This method leverages CT scan geometry, including conjugate ray information to learn the interpolation in sinogram domain. While the experiments are designed to cover the entire detector space, we emphasize on LPPs near detector iso-center as these have most adverse impact on image quality specially if the LPPs fall on the high frequency region (bone-tissue interface). We demonstrated efficacy of the proposed method using data acquired on GE RevACT multi-slice CT system with flat-panel detector. Experimental results on head scans show significant reduction in ring artifacts regardless of LPP location in the detector geometry. We have simulated isolated LPPs accounting for 5% and 10% of total channels. Detailed statistical analysis illustrates approximately 5dB improvement in SNR in both sinogram and reconstruction domain as compared to classical bicubic and Lagrange interpolation methods. Also, with reduction in ring and streak artifacts, the perceptual image quality is improved across all the test images.
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Aprendizado Profundo , Processamento de Imagem Assistida por Computador , Algoritmos , Artefatos , Processamento de Imagem Assistida por Computador/métodos , Tomografia Computadorizada por Raios X/métodosRESUMO
The front-line imaging modalities computed tomography (CT) and X-ray play important roles for triaging COVID patients. Thoracic CT has been accepted to have higher sensitivity than a chest X-ray for COVID diagnosis. Considering the limited access to resources (both hardware and trained personnel) and issues related to decontamination, CT may not be ideal for triaging suspected subjects. Artificial intelligence (AI) assisted X-ray based application for triaging and monitoring require experienced radiologists to identify COVID patients in a timely manner with the additional ability to delineate and quantify the disease region is seen as a promising solution for widespread clinical use. Our proposed solution differs from existing solutions presented by industry and academic communities. We demonstrate a functional AI model to triage by classifying and segmenting a single chest X-ray image, while the AI model is trained using both X-ray and CT data. We report on how such a multi-modal training process improves the solution compared to single modality (X-ray only) training. The multi-modal solution increases the AUC (area under the receiver operating characteristic curve) from 0.89 to 0.93 for a binary classification between COVID-19 and non-COVID-19 cases. It also positively impacts the Dice coefficient (0.59 to 0.62) for localizing the COVID-19 pathology. To compare the performance of experienced readers to the AI model, a reader study is also conducted. The AI model showed good consistency with respect to radiologists. The DICE score between two radiologists on the COVID group was 0.53 while the AI had a DICE value of 0.52 and 0.55 when compared to the segmentation done by the two radiologists separately. From a classification perspective, the AUCs of two readers was 0.87 and 0.81 while the AUC of the AI is 0.93 based on the reader study dataset. We also conducted a generalization study by comparing our method to the-state-art methods on independent datasets. The results show better performance from the proposed method. Leveraging multi-modal information for the development benefits the single-modal inferencing.
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The growth of SrRuO[Formula: see text] (SRO) thin film with high-crystallinity and low residual resistivity (RR) is essential to explore its intrinsic properties. Here, utilizing the adsorption-controlled growth technique, the growth condition of initial SrO layer on TiO[Formula: see text]-terminated SrTiO[Formula: see text] (STO) (001) substrate was found to be crucial for achieving a low RR in the resulting SRO film grown afterward. The optimized initial SrO layer shows a c(2 [Formula: see text] 2) superstructure that was characterized by electron diffraction, and a series of SRO films with different thicknesses (ts) were then grown. The resulting SRO films exhibit excellent crystallinity with orthorhombic-phase down to [Formula: see text] 4.3 nm, which was confirmed by high resolution X-ray measurements. From X-ray azimuthal scan across SRO orthorhombic (02 ± 1) reflections, we uncover four structural domains with a dominant domain of orthorhombic SRO [001] along cubic STO [010] direction. The dominant domain population depends on t, STO miscut angle ([Formula: see text]), and miscut direction ([Formula: see text]), giving a volume fraction of about 92 [Formula: see text] for [Formula: see text] 26.6 nm and [Formula: see text] (0.14[Formula: see text], 5[Formula: see text]). On the other hand, metallic and ferromagnetic properties were well preserved down to t [Formula: see text] 1.2 nm. Residual resistivity ratio (RRR = [Formula: see text]/[Formula: see text]) reduces from 77.1 for t [Formula: see text] 28.5 nm to 2.5 for t [Formula: see text] 1.2 nm, while [Formula: see text] increases from 2.5 [Formula: see text]cm for t [Formula: see text] 28.5 nm to 131.0 [Formula: see text]cm for t [Formula: see text] 1.2 nm. The ferromagnetic onset temperature ([Formula: see text]) of around 151 K remains nearly unchanged down to t [Formula: see text] 9.0 nm and decreases to 90 K for t [Formula: see text] 1.2 nm. Our finding thus provides a practical guideline to achieve high crystallinity and low RR in ultra-thin SRO films by simply adjusting the growth of initial SrO layer.
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Herein, using Raman spectroscopy, we have presented the investigation of a temperature-dependent frequency shift and the line broadening of phonon modes by inserting the atomic layers of Pb and PbTe in the prototype 3D topological insulator Bi2Te3. Good quality single crystals of Pb2Bi2Te3, PbBi2Te4, and PbBi4Te7 were grown using the modified Bridgman technique. The Raman modes show progressive blue-shift with the decrease in temperature from 298 K to 93 K in Pb2Bi2Te3, PbBi2Te4, and PbBi4Te7 due to the anharmonic vibrations of the lattice as well as the increase in the strength of Bi-Te covalent interactions. The experimental results were complemented by extensive first principles calculations, where a reasonable matching between the experimental and computational data was found. Chemical pressure, induced by the insertion of Pb and PbTe layers in Bi2Te3, modified the interactions at the boundaries of the quintuple-layers, which was evident from the evolution of the A21u mode. The enhancement in the out-of-plane Bi-Te vibrations with respect to the in-plane Bi-Te vibrations was observed at low temperatures. The temperature coefficients of the Raman modes were useful in determining the thermal conductivity, which is a key design parameter for the fabrication of spintronic devices using topological insulators. The estimated first order temperature coefficient (χ') for Pb2Bi2Te3 signified the decrease in the thermal conductivity relative to Bi2Te3, which was caused by the insertion of the Pb layers in the van der Waals gaps of Bi2Te3.
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We present a detail study of Shubinikov-de-Haas (SdH) oscillations accompanied by conductance fluctuations in a mesoscopic topological insulator PbBi4Te7 device. From SdH oscillations, the evidence of Dirac fermions with π Berry phase is found and the experimentally determined two main Fermi wave vectors are correlated to two surface Dirac cones (buried one inside the other) of layered topological insulator PbBi4Te7. We have also found evidence of conductance fluctuations, the root mean square amplitude of which is much higher than the usual universal conductance fluctuations observed in nanometer size sample. Calculated autocorrelation functions indicate periodic unique fluctuations may be associated with the topological surface states in the compound.
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The retrospective study was carried out to examine performance of Pottels height- independent equation compared to Schwartzs height-dependent equation to estimate glomerular filtration rate in 115 children in Indian setting. The Pottels equation performed well compared to updated Schwartz equation (R2=0.94, mean bias 0.25, 95% LOA=20.4, -19.9). The precision was better at lower range of estimated GFR.
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Taxa de Filtração Glomerular , Modelos Biológicos , Adolescente , Criança , Pré-Escolar , Creatinina/sangue , Feminino , Humanos , Índia , Masculino , Valor Preditivo dos Testes , Insuficiência Renal Crônica/diagnóstico , Insuficiência Renal Crônica/fisiopatologia , Reprodutibilidade dos Testes , Estudos RetrospectivosRESUMO
Parsing volumetric computed tomography (CT) into 10 or more salient organs simultaneously is a challenging task with many applications such as personalized scan planning and dose reporting. In the clinic, pre-scan data can come in the form of very low dose volumes acquired just prior to the primary scan or from an existing primary scan. To localize organs in such diverse data, we propose a new learning based framework that we call hierarchical pictorial structures (HPS) which builds multiple levels of models in a tree-like hierarchy that mirrors the natural decomposition of human anatomy from gross structures to finer structures. Each node of our hierarchical model learns (1) the local appearance and shape of structures, and (2) a generative global model that learns probabilistic, structural arrangement. Our main contribution is two fold. First we embed the pictorial structures approach in a hierarchical framework which reduces test time image interpretation and allows for the incorporation of additional geometric constraints that robustly guide model fitting in the presence of noise. Second we guide our HPS framework with the probabilistic cost maps extracted using random decision forests using volumetric 3D HOG features which makes our model fast to train and fast to apply to novel test data and posses a high degree of invariance to shape distortion and imaging artifacts. All steps require approximate 3 mins to compute and all organs are located with suitably high accuracy for our clinical applications such as personalized scan planning for radiation dose reduction. We assess our method using a database of volumetric CT scans from 81 subjects with widely varying age and pathology and with simulated ultra low dose cadaver pre-scan data.