The role of local-geometrical-orders on the growth of dynamic-length-scales in glass-forming liquids

The precise nature of complex structural relaxation as well as an explanation for the precipitous growth of relaxation time in cooling glass-forming liquids are essential to the understanding of vitrification of liquids. The dramatic increase of relaxation time is believed to be caused by the growth of one or more correlation lengths, which has received much attention recently. Here, we report a direct link between the growth of a specific local-geometrical-order and an increase of dynamic-length-scale as the atomic dynamics in metallic glass-forming liquids slow down. Although several types of local geometrical-orders are present in these metallic liquids, the growth of icosahedral ordering is found to be directly related to the increase of the dynamic-length-scale. This finding suggests an intriguing scenario that the transient icosahedral ordering could be the origin of the dynamic-length-scale in metallic glass-forming liquids.Comment: 15 pages, 3 Figure

In vitro investigation on the regenerative effect of Magnesium-based microparticles for osteoarthritis treatment

Osteoarthritis (OA) is one of the degenerative and epidemic joint disorders occurring worldwide. Although the molecular mechanisms are poorly understood, aging, gender, heredity, joint injury, impaired joint movement, stress and obesity are the main OA etiology. Till now there are no benchmark medical therapies for preventing or delaying OA onset. This thesis investigates the possibility of using Magnesium (Mg)-based microparticles in aiding the treatment of OA. Mg-based materials are thought to be a suitable biomaterial candidate due to their cytocompatibility, ability to degrade and noteworthy is their osteopromotive quality. The main objective of this research was to demonstrate the positive link of Mg implant in preventing the occurrence of OA. To achieve the objective this thesis covered a series of experiments right from the degradation of Mg implant in physiological medium to the implant’s compatibility on SCP1 cells. The final part investigated the association of Mg implants in an OA in vitro model revealing the significance of Mg in reducing the progression of OA. The evidence collected in this thesis leads to the conclusion that Mg-based microparticles have the potential to slow the progression of in vitro OA and help restore the differentiation potential/repair mechanism in bone and cartilage, depending on the severity of the inflammation. The ability of Mg microparticles to safely degrade with minimal toxicity on cells and the capability to support bone/cartilage repair mechanisms in vitro, makes Mg a versatile material for bone and cartilage tissue applications. The degradation rate, cytocompatible characteristics, and the demonstrated support for bone and cartilage repair mechanisms in vitro highlight the potential of Mg microparticles as an intelligent bioimplant material for OA therapy

A splicing-dependent transcriptional checkpoint associated with prespliceosome formation

There is good evidence for functional interactions between splicing and transcription in eukaryotes, but how and why these processes are coupled remain unknown. Prp5 protein (Prp5p) is an RNA-stimulated adenosine triphosphatase (ATPase) required for prespliceosome formation in yeast. We demonstrate through in vivo RNA labeling that, in addition to a splicing defect, the prp5-1 mutation causes a defect in the transcription of intron-containing genes. We present chromatin immunoprecipitation evidence for a transcriptional elongation defect in which RNA polymerase that is phosphorylated at Ser5 of the largest subunit’s heptad repeat accumulates over introns and that this defect requires Cus2 protein. A similar accumulation of polymerase was observed when prespliceosome formation was blocked by a mutation in U2 snRNA. These results indicate the existence of a transcriptional elongation checkpoint that is associated with prespliceosome formation during cotranscriptional spliceosome assembly. We propose a role for Cus2p as a potential checkpoint factor in transcription

Simultaneous local resolution along a rational valuation in two dimensional positive characteristic function fields

We consider the condition that a germ of an algebraic mapping of nonsingular surfaces can be made finite, after sufficient blowing up along a nondiscrete rational rank 1 valuation. This problem has been solved in the affirmative in characteristic zero by Abhyankar. He calls this simultaneous resolution. The essential new case that occurs in positive characteristic p is a chain of Artin-Schreier extensions. It is known that simultaneous local resolution is true (along a nondiscrete rational rank 1 valuation) for a single Artin-Schreier extension. We prove that simultaneous local resolution is true in a tower of two Artin-Schreier extensions.Includes bibliographical references

Identification of a novel nucleolin related protein (NRP) gene expressed during rat spermatogenesis

<p>Abstract</p> <p>Background</p> <p>Nucleolin is a major nucleolar phosphoprotein involved in various steps of ribosome biogenesis in eukaryotic cells. As nucleolin plays a significant role in ribosomal RNA transcription we were interested in examining in detail the expression of nucleolin across different stages of spermatogenesis and correlate with the transcription status of ribosomal DNA in germ cells.</p> <p>Results</p> <p>By RT PCR and western blot analysis we found that nucleolin is strongly down regulated in meiotic spermatocytes and haploid germ cells. We have identified a new nucleolin related protein (NRP) gene in the rat genome, which is over expressed in the testis and is up regulated several fold in meiotic spermatocytes and haploid germ cells. The NRP protein lacks the acidic stretches in its N terminal domain, and it is encoded in rat chromosome 15 having a different genomic organization as compared to nucleolin gene present on chromosome 9. We have also found NRP genes encoded in genomes of other mammalian species. We performed run-on transcription assay where we have observed that rDNA is transcribed at much lower level in meiotic spermatocytes and haploid spermatids as compared to diploid cells. By siRNA knock down experiments we could also demonstrate that NRP can support rDNA transcription in the absence of nucleolin.</p> <p>Conclusion</p> <p>We have identified a new nucleolin variant over expressed in germ cells in rat and analyzed its domain structure. We attribute that the transcriptional activity of rDNA genes in the late spermatogenesis is due to the presence of this variant NRP. The expression of this variant in the germ cells in the absence of nucleolin, could have additional functions in the mammalian spermatogenesis which needs to be investigated further.</p

Propolis Modulates Inflammatory Mediators and Improves Histopathology in Male Rats with L-arginine-induced Acute Pancreatitis

ABSTRACT: Objectives: This study aimed to determine the effects of propolis on immune mediators and tissue histopathology in rats with L-arginine-induced acute pancreatitis (AP). Methods: This study was conducted at Imam Abdulrahman Bin Faisal University, Dammam, Saudia Arabia between September and November 2017. A total of 24 male albino Wistar rats were divided into three equal groups. Group one was the negative control, group two was the positive control (L-arginine-induced AP) and group three received treatment (L-arginineinduced AP and propolis). The rats in group three were treated with 100 mg/kg propolis for seven days after AP induction. Pancreatic tissue was evaluated histologically and levels of interleukin (IL)-6, IL-22 and IL-1β and tumour necrosis factor-alpha (TNF-α) were measured. Results: Propolis reduced the quanitity of proinflammatory molecules (TNF-α, IL-1β and IL-6) in group three compared to group two, significantly increased the overall anti-inflammatory effect of IL-22 (P &lt;0.005) and reduced interstitial inflammation and neutrophil cell infiltration of the pancreatic tissues. Conclusion: Propolis may exert a therapeutic effect in AP. Further studies are required to demonstrate the mechanisms of propolis in AP.Keywords: Propolis; Arginine; Pancreatitis; Interleukins; Cytokinesis; Rats; Saudi Arabia

Chromatin architecture reorganisation during neuronal cell differentiation in Drosophila genome

The organization of the genome into topologically associating domains (TADs) was shown to have a regulatory role in development and cellular functioning, but the mechanism involved in TAD establishment is still unclear. Here, we presented the first high-resolution contact map of Drosophila neuronal cells (BG3) and identified different classes of TADs by comparing this to genome organization in embryonic cells (Kc167). We find that only some TADs are conserved in both cell lines, whereas the rest are cell-specific TADs. This is supported by a change in the enrichment of architectural proteins at TAD borders, with BEAF-32 present in embryonic cells and CTCF in neuronal cells. Furthermore, we observed strong divergent transcription, together with RNA Polymerase II occupancy, and an increase in DNA accessibility at the TAD borders. TAD borders that are specific to neuronal cells are enriched in enhancers controlled by neuronal-specific transcription factors. Our results suggest that TADs are dynamic across developmental stages and reflect the interplay between insulators, transcriptional states and enhancer activities

Small-sized magnesium cylinders influence subchondral bone quality in osteoarthritic rabbits an – in vivo pilot study

No optimal therapy exists to stop or cure chondral degeneration in osteoarthritis (OA). While the pathogenesis is unclear, there is consensus on the etiological involvement of both articular cartilage and subchondral bone. Compared to original bone, the substance of sclerotic bone is mechanically less solid. The osteoproliferative effect of Mg has been shown repeatedly during development of Mg-based osteosynthesis implants. The aim of the present study was to examine the influence of implanted high-purity Mg cylinders on subchondral bone quality in a rabbit OA model. 10 New Zealand White rabbits received into the knee either 20 empty drill holes or 20 drill holes, which were additionally filled with one Mg cylinder each. Follow-up was at 8 weeks. Micro-computed tomography (µCT) was performed. After euthanasia, cartilage condition was determined, bone samples were collected and processed for histological evaluation and elemental imaging by micro-Xray fluorescence spectrometry (µXRF). Articular cartilage collected post-mortem showed different stages of lesions, from mild alterations up to exposed subchondral bone, which tended to be slightly lower in animals with implanted Mg cylinders. µCT showed significantly increased bone volume in the Mg group. Also, histological evaluation revealed distinct differences. While right, operated limbs did not show any significant difference, left, non-operated controls showed significantly less changes in articular cartilage in the Mg group. A distinct influence of implanted cylinders of pure Mg on subchondral bone of osteoarthritic rabbits was shown. Subsequent evaluations, including other time points and alternative alloys, will show if this could alter OA progression

INTERNET BEHAVIOUR PATTERN IN UNDERGRADUATE MEDICAL STUDENTS IN MANGALORE

Abstract: Considering the explosive growth in internet use among medical students in India, this study aimed to determine the prevalence of internet addiction in undergraduate medical students.This cross-sectional study involved 90 subjects (18-20 years of age) selected by random sampling from the first year undergraduate medical student population at Kasturba Medical College Mangalore. Young&apos;s Internet addiction test questionnaire was administered. Based on the scoring, subjects were classified into normal users (score &lt;20), mild (score 20-49), moderate (score 50-79) and severe (score &gt;79) internet addiction groups.The prevalence of internet addiction (moderate and severe) was determined to be 18.88%. Majority (57.77%) conformed to mild addiction. The most common purpose for internet use was found to be social networking (97.8%), followed closely by e mailing (87.8%).The prevalence of moderate to severe internet addiction appeared to be low, a significant number of students conform to mild addiction

Variation in Nigella sativa quality and its standardization via instrumental analysis: A study based on geographical origin

Black seeds (Nigella sativa) owe an important place due to its more demand as a food as well as medicine. A lack of information does exist regarding the quality and safety for market-available food-grade samples of black seed (BS). The aim of this study is to investigate the quality and standardize the BS samples according to world health organization (WHO) guidelines of instrumental analysis and pharmacological activities. Instrumental analysis was performed with the help of ASE (accelerated solvent extraction), IR (infrared spectroscopy), UHPLC (ultra-high-performance liquid chromatography) and NMR (nuclear magnetic resonance spectroscopy) whereas ash values and chemical tests were applied for physicochemical analysis. DPPH (2,2-diphenyl-1-picrylhydrazyl), ABTS (2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) and cytotoxicity assay were performed as well. A high extract yield (g) with recovery of 4.4 ± 7.7 (22%) for Pakistani, 3.3 ± 4.7 (16.5%) for Indian and 3.02 ± 10.2 (15.1%) for Saudi Arabian sample. Chemical tests showed the presence of phenolic compounds and flavonoids. Saudi Arabian samples showed less amount for ash values (total-, water soluble- and acid insoluble ash). The samples were standardized further with the help of NMR and IR. A significant amount of micro- and macronutrients was observed in Saudi Arabian sample. With regard to the major active substance Thymoquinone (THQ; ng/mL), the order of concentration was observed as; Saudi Arabian sample (33141.1) &gt; Pakistani (7677.2) &gt; Indian sample (3998.6). A more potency for Saudi Arabian sample was observed during antioxidant and cytotoxicity assays. The method was successful to effectively discriminate the samples from different geographical origin, in terms of quality