249 research outputs found
Biological Response of Biphasic Hydroxyapatite/Tricalcium Phosphate Scaffolds Intended for Low Load-Bearing Orthopaedic Applications:
In this study, a calcium phosphate scaffold of hydroxyapatite (HAp) and dicalcium phosphate dihydrate (DCPD) for application in osteoconductive and osteoinductive scaffolds was synthesized and characterized. The important note is that the prepared composites converted to HAp/tricalcium phosphate (TCP) after heat-treatment. This class of composites is interesting because porous HAp/TCP generally degrade more rapid than HAp due to the increased resorption rate of TCP. According to the obtained results, the values of elastic modulus, compressive strength and density of the samples reduced with increasing the percentage of the DCPD phase. It is worth mentioning that the mechanical properties of the prepared samples were near the natural compact bone. The samples were examined in vitro to confirm the apatite forming ability of the composites. Also, in vivo examination in a rabbit model was employed. After fully observation it was concluded that new bone formed on the pore walls, as osteoids and osteoclasts were evident two months postoperatively. Based on the obtained results, the prepared scaffolds seem to be a promising biomaterial for low weight bearing orthopaedic applications
Multi-omics assessment of dilated cardiomyopathy using non-negative matrix factorization
Dilated cardiomyopathy (DCM), a myocardial disease, is heterogeneous and often results in
heart failure and sudden cardiac death. Unavailability of cardiac tissue has hindered the
comprehensive exploration of gene regulatory networks and nodal players in DCM. In this
study, we carried out integrated analysis of transcriptome and methylome data using nonnegative matrix factorization from a cohort of DCM patients to uncover underlying latent factors and covarying features between whole-transcriptome and epigenome omics datasets
from tissue biopsies of living patients. DNA methylation data from Infinium HM450 and
mRNA Illumina sequencing of n = 33 DCM and n = 24 control probands were filtered, analyzed and used as input for matrix factorization using R NMF package. Mann-Whitney U test
showed 4 out of 5 latent factors are significantly different between DCM and control probands (P<0.05). Characterization of top 10% features driving each latent factor showed a
significant enrichment of biological processes known to be involved in DCM pathogenesis,
including immune response (P = 3.97E-21), nucleic acid binding (P = 1.42E-18), extracellular matrix (P = 9.23E-14) and myofibrillar structure (P = 8.46E-12). Correlation network analysis revealed interaction of important sarcomeric genes like Nebulin, Tropomyosin alpha-3
and ERC-protein 2 with CpG methylation of ATPase Phospholipid Transporting 11A0, Solute Carrier Family 12 Member 7 and Leucine Rich Repeat Containing 14B, all with significant P values associated with correlation coefficients >0.7. Using matrix factorization, multiomics data derived from human tissue samples can be integrated and novel interactions
can be identified. Hypothesis generating nature of such analysis could help to better understand the pathophysiology of complex traits such as DCM
Conservative management of ovarian fibroma in a case of Gorlin-Goltz syndrome comorbid with endometriosis
Ovarian fibromas are the most common benign solid ovarian tumors, which are often difficult to diagnose preoperatively. Ovarian fibromas, especially in bilateral cases, may be cases of Gorlin-Goltz syndrome (GGS), a rare autosomal dominant disorder with predisposition to basal cell carcinomas (BCCs) and other various benign and malignant tumors. This case report describes a 25 year-old female with GGS, bilateral ovarian fibroma, endometriosis and septated uterus, which was referred to the Gynecology Clinic of Rasoul-e-Akram Hospital in October 2016. This patient had facial asymmetry due to recurrent odontogenic keratocysts. In young cases of ovarian fibromas as reported here, conservative surgical management can preserve ovarian function and fertility. These patients must be followed up by a multidisciplinary team and submitted to periodic tests. © 2018, Royan Institute (ACECR). All rights reserved
Conservative management of ovarian fibroma in a case of Gorlin-Goltz syndrome comorbid with endometriosis
Ovarian fibromas are the most common benign solid ovarian tumors, which are often difficult to diagnose preoperatively. Ovarian fibromas, especially in bilateral cases, may be cases of Gorlin-Goltz syndrome (GGS), a rare autosomal dominant disorder with predisposition to basal cell carcinomas (BCCs) and other various benign and malignant tumors. This case report describes a 25 year-old female with GGS, bilateral ovarian fibroma, endometriosis and septated uterus, which was referred to the Gynecology Clinic of Rasoul-e-Akram Hospital in October 2016. This patient had facial asymmetry due to recurrent odontogenic keratocysts. In young cases of ovarian fibromas as reported here, conservative surgical management can preserve ovarian function and fertility. These patients must be followed up by a multidisciplinary team and submitted to periodic tests. © 2018, Royan Institute (ACECR). All rights reserved
Epigenetic Regulation of Alternative mRNA Splicing in Dilated Cardiomyopathy
In recent years, the genetic architecture of dilated cardiomyopathy (DCM) has been
more thoroughly elucidated. However, there is still insufficient knowledge on the modifiers and
regulatory principles that lead to the failure of myocardial function. The current study investigates the
association of epigenome-wide DNA methylation and alternative splicing, both of which are important
regulatory principles in DCM. We analyzed screening and replication cohorts of cases and controls
and identified distinct transcriptomic patterns in the myocardium that differ significantly, and we
identified a strong association of intronic DNA methylation and flanking exons usage (p < 2 × 10−16).
By combining differential exon usage (DEU) and differential methylation regions (DMR), we found
a significant change of regulation in important sarcomeric and other DCM-associated pathways.
Interestingly, inverse regulation of Titin antisense non-coding RNA transcript splicing and DNA
methylation of a locus reciprocal to TTN substantiate these findings and indicate an additional role
for non-protein-coding transcripts. In summary, this study highlights for the first time the close
interrelationship between genetic imprinting by DNA methylation and the transport of this epigenetic
information towards the dynamic mRNA splicing landscape. This expands our knowledge of the
genome–environment interaction in DCM besides simple gene expression regulation
HopScotch - a low-power renewable energy base station network for rural broadband access
The provision of adequate broadband access to communities in sparsely populated rural areas has in the past been severely restricted. In this paper, we present a wireless broadband access test bed running in the Scottish Highlands and Islands which is based on a relay network of low-power base stations. Base stations are powered by a combination of renewable sources creating a low cost and scalable solution suitable for community ownership. The use of the 5~GHz bands allows the network to offer large data rates and the testing of ultra high frequency ``white space'' bands allow expansive coverage whilst reducing the number of base stations or required transmission power. We argue that the reliance on renewable power and the intelligent use of frequency bands makes this approach an economic green radio technology which can address the problem of rural broadband access
Oxidation of Cellular Amino Acid Pools Leads to Cytotoxic Mistranslation of the Genetic Code
Aminoacyl-tRNA synthetases use a variety of mechanisms to ensure fidelity of the genetic code and ultimately select the correct amino acids to be used in protein synthesis. The physiological necessity of these quality control mechanisms in different environments remains unclear, as the cost vs benefit of accurate protein synthesis is difficult to predict. We show that in Escherichia coli, a non-coded amino acid produced through oxidative damage is a significant threat to the accuracy of protein synthesis and must be cleared by phenylalanine-tRNA synthetase in order to prevent cellular toxicity caused by mis-synthesized proteins. These findings demonstrate how stress can lead to the accumulation of non-canonical amino acids that must be excluded from the proteome in order to maintain cellular viability
Developments in the negative-U modelling of the cuprate HTSC systems
The paper deals with the many stands that go into creating the unique and
complex nature of the HTSC cuprates above Tc as below. Like its predecessors it
treats charge, not spin or lattice, as prime mover, but thus taken in the
context of the chemical bonding relevant to these copper oxides. The crucial
shell filling, negative-U, double-loading fluctuations possible there require
accessing at high valent local environment as prevails within the mixed valent,
inhomogeneous two sub-system circumstance of the HTSC materials. Close
attention is paid to the recent results from Corson, Demsar, Li, Johnson,
Norman, Varma, Gyorffy and colleagues.Comment: 44 pages:200+ references. Submitted to J.Phys.:Condensed Matter, Sept
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