215 research outputs found
Stokes drag on axially symmetric body in micro polar fluid
In a recent paper, Srivastava et al. (2016) have tested the proposed formula based on DS-conjecture Datta and Srivastava, (1999) of Stokes drag on axially symmetric bodies placed under micropolar fluid to improve the drag value under Oseen’s limit. In the present work, proof of the proposed drag formula is given for both axial and transverse Stokes flow of micropolar fluid under certain body geometry constraints mainly of continuously turning tangent on body curve in meridional plane as assumed in DS-conjecture. The general expression of drag immediately reduces to the value of drag in classical Newtonian fluid as micro polarity parameter k approaches to zero. The proposed expressions of Stokes drag are applied to various axially symmetric bodies like sphere, spheroid, deformed sphere, cycloidal body, Cassini body, Hypocycloidal body and egg-shaped body and results are in agreement with some known values available in the literature in the limiting cases
Steady Quadratic Stokes Flow Past Deformed Sphere: A Novel Perturbation Technique
In this paper, the problem of steady quadratic Stokes flow past a deformed sphere has been tackled with the use of a novel perturbation technique in both situations when a uniform stream is along the axis of symmetry (axial flow) and when it is perpendicular to the axis of symmetry (transverse flow). The most general form of the deformed sphere, governed by polar equation, is considered here for the study. The general expressions for axial and transverse Stokes drag for deformed sphere has been derived up to the second order of deformation parameter for parabolic and stagnation like parabolic flow. The class of prolate, oblate and egg-shaped axisymmetric bodies is considered for the validation and further numerical discussions. The numerical values of the drag coefficients and their ratio have been evaluated for the various values of deformation parameters, eccentricity and aspect ratio and corresponding variations are depicted via graphs
Minimal cross-recombination between wild-type and loxP511 sites in vivo facilitates truncating both ends of large DNA inserts in pBACe3.6 and related vectors
Contrary to several earlier reports, we find that cross-recombination between wild-type and the mutant loxP511 sites is <0.5% of that between two wild-type sites if Cre protein is expressed by phage P1 during an infection. The finding enabled us to develop a procedure to truncate DNA progressively from both ends of large genomic inserts flanked by these two loxP sites in pBACe3.6 and related vectors with transposons carrying either a wild-type or a loxP511 sequence. Newly constructed loxP511 transposons contained either a kanamycin resistance gene or no marker. Insert DNA ends in deletions were sequenced with primers unique to each transposon-end remaining after the respective recombination. End-sequencing 223 deletions confirmed that the low level of cross-recombination, observed between those sites during the P1 transductions, does not complicate the procedure: truncations from the unintended end of genomic inserts did not occur. Multiple BACs pooled together could also be processed in a single tube to make end-deletions. This deletion technology, utilizing the very minimal cross-recombination between the mutant and wild-type loxP sites of most BAC clones in the public domain and a heterologous one inserted as a transposon, should facilitate functionally mapping long-range gene regulatory sequences and help to isolate genes with defined functional boundaries in numerous projects including those of therapeutic interest
Evaluation of metabolic status and milk compositions of indigenous cattle with subclinical mastitis and its amelioration by nutritional supplementations
Indigenous cattle that were in early lactation and positive for subclinical mastitis were allocated into 2 groups; one group was administered with nutrional supplements (50 g mixture of vitamins A, D, E and thiamine, riboflavin, pantothenic acid, biotin, niacin, trisodium citrate dihydrate, methionine, manganese, copper, zinc, cobalt, selenium and live yeasts orally daily for 7 days), while other was kept as negative control. Milk composition of mastitic milk and metabolic status of affected cows were evaluated at day 0 and day 7 post-therapy. On day 0, remarkable alteration in milk composition as well as in metabolic status of affected animals was recorded in comparison to the healthy control. However, the altered nutrional panels as well as milk compositions were ameliorated toward normalcy at day 7 post-therapy in mastitic cows administered with nutrional supplements. At day 7 post-therapy, remarkable improvements in somatic cell count was also recorded in these cows when compared with day 0 values within the group, but the values were still significantly higher than the healthy control. Thus, subclinical mastitis in indigenous cattle could bestow remarkable alterations in milk compositions and metabolic status. The altered metabolic panels and milk compositions can be ameliorated toward normalcy by administering nutritional supplements
Nanotechnology Synergised Immunoengineering for Cancer
Novel strategies modulating the immune system yielded enhanced anticancer responses and improved cancer survival. Nevertheless, the success rate of immunotherapy in cancer treatment has been below expectation(s) due to unpredictable efficacy and off-target effects from systemic dosing of immunotherapeutic. As a result, there is an unmet clinical need for improving conventional immunotherapy. Nanotechnology offers several new strategies, multimodality, and multiplex biological targeting advantage to overcome many of these challenges. These efforts enable programming the pharmacodynamics, pharmacokinetics, delivery of immunomodulatory agents/co-delivery of compounds to prime at the tumor sites for improved therapeutic benefits. This review provides an overview of the design and clinical principles of biomaterials driven nanotechnology and their potential use in personalized nanomedicines, vaccines, localized tumor modulation, and delivery strategies for cancer immunotherapy. In this review, we also summarize the latest highlights and recent advances in combinatorial therapies avail in the treatment of cold and complicated tumors. It also presents key steps and parameters implemented for clinical success. Finally, we analyse, discuss, and provide clinical perspectives on the integrated opportunities of nanotechnology and immunology to achieve synergistic and durable responses in cancer treatment
Liposomal nanotheranostics for multimode targeted in vivo bioimaging and near‐infrared light mediated cancer therapy
Developing a nanotheranostic agent with better image resolution and high accumulation into solid tumor microenvironment is a challenging task. Herein, we established a light mediated phototriggered strategy for enhanced tumor accumulation of nanohybrids. A multifunctional liposome based nanotheranostics loaded with gold nanoparticles (AuNPs) and emissive graphene quantum dots (GQDs) were engineered named as NFGL. Further, doxorubicin hydrochloride was encapsulated in NFGL to exhibit phototriggered chemotherapy and functionalized with folic acid targeting ligands. Encapsulated agents showed imaging bimodality for in vivo tumor diagnosis due to their high contrast and emissive nature. Targeted NFGL nanohybrids demonstrated near infrared light (NIR, 750 nm) mediated tumor reduction because of generated heat and Reactive Oxygen Species (ROS). Moreover, NFGL nanohybrids exhibited remarkable ROS scavenging ability as compared to GQDs loaded liposomes validated by antitumor study. Hence, this approach and engineered system could open new direction for targeted imaging and cancer therapy.publishersversionpublishe
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EM-mosaic detects mosaic point mutations that contribute to congenital heart disease.
BackgroundThe contribution of somatic mosaicism, or genetic mutations arising after oocyte fertilization, to congenital heart disease (CHD) is not well understood. Further, the relationship between mosaicism in blood and cardiovascular tissue has not been determined.MethodsWe developed a new computational method, EM-mosaic (Expectation-Maximization-based detection of mosaicism), to analyze mosaicism in exome sequences derived primarily from blood DNA of 2530 CHD proband-parent trios. To optimize this method, we measured mosaic detection power as a function of sequencing depth. In parallel, we analyzed our cohort using MosaicHunter, a Bayesian genotyping algorithm-based mosaic detection tool, and compared the two methods. The accuracy of these mosaic variant detection algorithms was assessed using an independent resequencing method. We then applied both methods to detect mosaicism in cardiac tissue-derived exome sequences of 66 participants for which matched blood and heart tissue was available.ResultsEM-mosaic detected 326 mosaic mutations in blood and/or cardiac tissue DNA. Of the 309 detected in blood DNA, 85/97 (88%) tested were independently confirmed, while 7/17 (41%) candidates of 17 detected in cardiac tissue were confirmed. MosaicHunter detected an additional 64 mosaics, of which 23/46 (50%) among 58 candidates from blood and 4/6 (67%) of 6 candidates from cardiac tissue confirmed. Twenty-five mosaic variants altered CHD-risk genes, affecting 1% of our cohort. Of these 25, 22/22 candidates tested were confirmed. Variants predicted as damaging had higher variant allele fraction than benign variants, suggesting a role in CHD. The estimated true frequency of mosaic variants above 10% mosaicism was 0.14/person in blood and 0.21/person in cardiac tissue. Analysis of 66 individuals with matched cardiac tissue available revealed both tissue-specific and shared mosaicism, with shared mosaics generally having higher allele fraction.ConclusionsWe estimate that ~ 1% of CHD probands have a mosaic variant detectable in blood that could contribute to cardiac malformations, particularly those damaging variants with relatively higher allele fraction. Although blood is a readily available DNA source, cardiac tissues analyzed contributed ~ 5% of somatic mosaic variants identified, indicating the value of tissue mosaicism analyses
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