636 research outputs found

    Biocompatibility and applications of carbon nanotubes in medical nanorobots

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    The set of nanoelectromechanical systems (NEMS) based on relative motion of carbon nanotubes walls is proposed for use in medical nanorobots. This set includes electromechanical nanothermometer, jet nanoengine, nanosyringe (the last can be used simultaneously as nanoprobe for individual biological molecules and drug nanodeliver). Principal schemes of these NEMS are considered. Operational characteristics of nanothermometer are analyzed. The possible methods of these NEMS actuation are considered. The present-day progress in nanotechnology techniques which are necessary for assembling of NEMS under consideration is discussed. Biocompatibility of carbon nanotubes is analyzed in connection with perspectives of their application in nanomedicine

    Biocompatibility and applications of carbon nanotubes in medical nanorobots

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    The set of nanoelectromechanical systems (NEMS) based on relative motion of carbon nanotubes walls is proposed for use in medical nanorobots. This set includes electromechanical nanothermometer, jet nanoengine, nanosyringe (the last can be used simultaneously as nanoprobe for individual biological molecules and drug nanodeliver). Principal schemes of these NEMS are considered. Operational characteristics of nanothermometer are analyzed. The possible methods of these NEMS actuation are considered. The present-day progress in nanotechnology techniques which are necessary for assembling of NEMS under consideration is discussed. Biocompatibility of carbon nanotubes is analyzed in connection with perspectives of their application in nanomedicine

    Dokaz i izdvajanje skupine A rotavirusa iz devine teladi u Sudanu.

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    A total of 332 fecal samples were collected from 245 diarrheic as well as 75 recovered and 12 healthy camel calves in four different areas in Sudan [north (River Nile), east (Gedarif), central to south (Sennar, Blue Nile) and west (Kordofan) States]. Using ELISA, 46 samples (13.9%) were found positive for group A rotavirus. Out of 46 ELISA positive calves, we found 35 diarrheic up to 3 months of age, 7 recovered 4-6 months of age and 4 clinically healthy 8-12 months of age. Using EM, 6 out of 22 ELISA positive samples showed the well defined wheel-like structure characteristic of rotavirus. The results indicate the significant role of rotavirus in the epidemiology of camel calf diarrhea in Sudan. Attempts to isolate the camel group A rotavirus in MA104 cell culture were carried out on 21 ELISA-positive samples with successful isolation of the virus in 18. The isolated viruses were identified by ELISA and EM. Cytopathic effects (CPE) were manifested as rounding, elongation, triangulation, vacuolation and granulation of cells while the cell sheet remains intact. The CPE appeared on days 3-5 on the first to the second passages after treatment of the inocula and the cell culture media with trypsin. To our knowledge this is the first report on the isolation of camel rotavirus in cell culture.Prikupljena su 332 uzorka fecesa od 245 devine teladi s proljevom, 75 teladi oporavljene od proljeva i 12 od zdrave devine teladi sa četiri različita područja u Sudanu: sjevernoga (područje rijeke Nila), istočnoga (područje Gedarif), srediÅ”njega i južnoga (područje Sennar, Plavi Nil) te zapadnoga područja (Kordofan). Pretragom imunoenzimnim testom 46 uzoraka (13,9%) bilo je pozitivno za skupinu A rotavirusa. Od tih 46 pozitivnih životinja imunoenzimnim testom, 35 s proljevom bilo je u dobi do tri mjeseca, sedam s preboljelim proljevom bilo je u dobi od četiri do Å”est mjeseci, a četiri životinje u dobi od osam do 12 mjeseci bile su klinički zdrave. Elektronskom mikroskopijom dokazane su čestice karakteristične za rotavirus u Å”est od 22 uzorka pozitivna pretragom imunoenzimnim testom. Rezultati ukazuju na znatnu ulogu rotavirusa u epizootiologiji proljeva u devine mladunčadi u Sudanu. Skupina A rotavirusa izdvojena je na MA104 staničnoj kulturi iz 18 od 21 uzorka pozitivnoga pretragom imunoenzimnim testom. Izdvojeni virusi bili su identificirani imunoenzimnim testom i elekronskom mikroskopijom. Citopatski učinak očitovao se zaokruživanjem stanica, njihovim izduživanjem, triangulacijom, vakuolacijom i granulacijom, dok je stanični sloj ostao netaknut. Citopatski učinak javljao se za tri do pet dana u prvoj i drugoj pasaži nakon obradbe inokula i staničnog medija tripsinom. Ovo je prvo izvjeŔće o izdvajanju rotavirusa deva u staničnoj kulturi

    QuantiMus: A Machine Learning-Based Approach for High Precision Analysis of Skeletal Muscle Morphology.

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    Skeletal muscle injury provokes a regenerative response, characterized by the de novo generation of myofibers that are distinguished by central nucleation and re-expression of developmentally restricted genes. In addition to these characteristics, myofiber cross-sectional area (CSA) is widely used to evaluate muscle hypertrophic and regenerative responses. Here, we introduce QuantiMus, a free software program that uses machine learning algorithms to quantify muscle morphology and molecular features with high precision and quick processing-time. The ability of QuantiMus to define and measure myofibers was compared to manual measurement or other automated software programs. QuantiMus rapidly and accurately defined total myofibers and measured CSA with comparable performance but quantified the CSA of centrally-nucleated fibers (CNFs) with greater precision compared to other software. It additionally quantified the fluorescence intensity of individual myofibers of human and mouse muscle, which was used to assess the distribution of myofiber type, based on the myosin heavy chain isoform that was expressed. Furthermore, analysis of entire quadriceps cross-sections of healthy and mdx mice showed that dystrophic muscle had an increased frequency of Evans blue dye+ injured myofibers. QuantiMus also revealed that the proportion of centrally nucleated, regenerating myofibers that express embryonic myosin heavy chain (eMyHC) or neural cell adhesion molecule (NCAM) were increased in dystrophic mice. Our findings reveal that QuantiMus has several advantages over existing software. The unique self-learning capacity of the machine learning algorithms provides superior accuracy and the ability to rapidly interrogate the complete muscle section. These qualities increase rigor and reproducibility by avoiding methods that rely on the sampling of representative areas of a section. This is of particular importance for the analysis of dystrophic muscle given the "patchy" distribution of muscle pathology. QuantiMus is an open source tool, allowing customization to meet investigator-specific needs and provides novel analytical approaches for quantifying muscle morphology

    Seismic Microzonation of Central Khartoum, Sudan

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    A preliminary seismic microzonation of Central Khartoum, Sudan is proposed. Khartoum, the capital of Sudan, is located at the confluence of White and Blue Niles. The city is heavily populated. The Central Khartoum with its high rise buildings is the center of governmental and business activities and is located on strip adjacent to the Blue Nile. Geological and geotechnical data indicated that the subsoil conditions at Central Khartoum are characterized by alluvial deposits underlain by Nubian Sandstone below a depth of 20 m. The alluvial deposits locally known as Gezira formations, consist of clays grading into silt and sand with depth. Macro seismic zonation of Sudan and its vicinities, developed by the authors, gave the ground acceleration at the bed rock surface. The effect of alluvial deposits at Central Khartoum on propagation of seismic motion parameters to the ground surface is investigated in this study. Correlations are proposed for pertinent cyclic soil properties such as shear modulus, damping, and shear wave velocity. The classical shear beam model developed by Idriss and Seed is used to study the effect of local soil conditions on ground motion parameters. In absence of strong motion records, artificial time histories of ground motion parameters are used. Plots showing the time histories of ground motion parameters at the ground surface are obtained. The results indicated amplification of ground acceleration of up to 1.15. Because of the presence of saturated loose to medium dense sand at some locations within Central Khartoum, the risk of earthquake-induced liquefaction is evaluated. The susceplity of subsoils in Central Khartoum to liguefaction is evaluated probabilistically by modifying the classical method developed by Seed and Idriss. The risk of earthquake-induced liquefaction is computed by combining the seismic hazard and the conditional probability of liquefaction. The study showed that the risk of liquefaction is low

    On the Complexity of Query Result Diversification

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    Query result diversification is a bi-criteria optimization problem for ranking query results. Given a database D, a query Q and a positive integer k, it is to find a set of k tuples from Q(D) such that the tuples are as relevant as possible to the query, and at the same time, as diverse as possible to each other. Subsets of Q(D) are ranked by an objective function defined in terms of relevance and diversity. Query result diversification has found a variety of applications in databases, information retrieval and operations research. This paper studies the complexity of result diversification for relational queries. We identify three problems in connection with query result diversification, to determine whether there exists a set of k tuples that is ranked above a bound with respect to relevance and diversity, to assess the rank of a given k-element set, and to count how many k-element sets are ranked above a given bound. We study these problems for a variety of query languages and for three objective functions. We establish the upper and lower bounds of these problems, all matching, for both combined complexity and data complexity. We also investigate several special settings of these problems, identifying tractable cases. 1

    Second T = 3/2 state in 9^9B and the isobaric multiplet mass equation

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    Recent high-precision mass measurements and shell model calculations~[Phys. Rev. Lett. {\bf 108}, 212501 (2012)] have challenged a longstanding explanation for the requirement of a cubic isobaric multiplet mass equation for the lowest A=9A = 9 isospin quartet. The conclusions relied upon the choice of the excitation energy for the second T=3/2T = 3/2 state in 9^9B, which had two conflicting measurements prior to this work. We remeasured the energy of the state using the 9Be(3He,t)^9{\rm Be}(^3{\rm He},t) reaction and significantly disagree with the most recent measurement. Our result supports the contention that continuum coupling in the most proton-rich member of the quartet is not the predominant reason for the large cubic term required for A=9A = 9 nuclei

    Spatiotemporal changes in substantia nigra neuromelanin content in Parkinsonā€™s disease

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    This study aimed to investigate the spatiotemporal changes in neuromelanin-sensitive MRI signal in the substantia nigra and their relation to clinical scores of disease severity in patients with early or progressing Parkinsonā€™s disease and patients with idiopathic rapid eye movement sleep behaviour disorder (iRBD) exempt of Parkinsonian signs compared to healthy control subjects. Longitudinal T1-weighted anatomical and neuromelanin-sensitive MRI was performed in two cohorts, including patients with iRBD, patients with early or progressing Parkinsonā€™s disease, and control subjects. Based on the aligned substantia nigra segmentations using a study-specific brain anatomical template, parametric maps of the probability of a voxel belonging to the substantia nigra were calculated for patients with various degrees of disease severity and controls. For each voxel in the substantia nigra, probability map of controls, correlations between signal-to-noise ratios on neuromelanin-sensitive MRI in patients with iRBD and Parkinsonā€™s disease and clinical scores of motor disability, cognition and mood/behaviour were calculated. Our results showed that in patients, compared to the healthy control subjects, the volume of the substantia nigra was progressively reduced for increasing disease severity. The neuromelanin signal changes appeared to start in the posterolateral motor areas of the substantia nigra and then progressed to more medial areas of this region. The ratio between the volume of the substantia nigra in patients with Parkinsonā€™s disease relative to the controls was best fitted by a mono-exponential decay. Based on this model, the pre-symptomatic phase of the disease started at 5.3 years before disease diagnosis, and 23.1% of the substantia nigra volume was lost at the time of diagnosis, which was in line with previous findings using post-mortem histology of the human substantia nigra and radiotracer studies of the human striatum. Voxel-wise patterns of correlation between neuromelanin-sensitive MRI signal-to-noise ratio and motor, cognitive and mood/behavioural clinical scores were localized in distinct regions of the substantia nigra. This localization reflected the functional organization of the nigrostriatal system observed in histological and electrophysiological studies in non-human primates (motor, cognitive and mood/behavioural domains). In conclusion, neuromelanin-sensitive MRI enabled us to assess voxel-wise modifications of substantia nigraā€™s morphology in vivo in humans, including healthy controls, patients with iRBD and patients with Parkinsonā€™s disease, and identify their correlation with nigral function across all motor, cognitive and behavioural domains. This insight could help assess disease progression in drug trials of disease modification
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