364 research outputs found
Photon CT Scanning of Advanced Ceramic Materials
Advanced ceramic materials (e. g. Si3N4, ZrO2, SiC, A12O3) are being developed for high temperature applications in advanced heat engines and high temperature heat recovery systems [1]. Although fracture toughness has been a constant problem, advanced ceramics are now being developed with fracture toughnesses close to those of metals [2]. Small size flaws (10–200 μm), small non-uniformities in density distributions (0.1–2%) present as long-range density gradients, and porous regions which can be seen as localized areas of slightly lower density, are critical in most ceramics. The need to detect these small flaws is causing a significant effort to be devoted towards nondestructive evaluation. Detection of “defects” such as those noted in engineering ceramics has presented problems for conventional non-destructive evaluation methods [3]
Intragenic DNA methylation: implications of this epigenetic mechanism for cancer research
Epigenetics is the study of all mechanisms that regulate gene transcription and genome stability that are maintained throughout the cell division, but do not include the DNA sequence itself. The best-studied epigenetic mechanism to date is DNA methylation, where methyl groups are added to the cytosine base within cytosine–guanine dinucleotides (CpG sites). CpGs are frequently clustered in high density (CpG islands (CGIs)) at the promoter of over half of all genes. Current knowledge of transcriptional regulation by DNA methylation centres on its role at the promoter where unmethylated CGIs are present at most actively transcribed genes, whereas hypermethylation of the promoter results in gene repression. Over the last 5 years, research has gradually incorporated a broader understanding that methylation patterns across the gene (so-called intragenic or gene body methylation) may have a role in transcriptional regulation and efficiency. Numerous genome-wide DNA methylation profiling studies now support this notion, although whether DNA methylation patterns are a cause or consequence of other regulatory mechanisms is not yet clear. This review will examine the evidence for the function of intragenic methylation in gene transcription, and discuss the significance of this in carcinogenesis and for the future use of therapies targeted against DNA methylation
Incomplete oedipism and chronic suicidality in psychotic depression with paranoid delusions related to eyes
Self-enucleation or oedipism is a term used to describe self-inflicted enucleation. It is a rare form of self-mutilation, found mainly in acutely psychotic patients. We propose the term incomplete oedipism to describe patients who deliberately and severely mutilate their eyes without proper enucleation. We report the case of a 32-year-old male patient with a five-year history of psychotic depression accompanied by paranoid delusions centered around his belief that his neighbors criticized him and stared at him. A central feature of his clinical picture was an eye injury that the patient had caused by pouring molten lead into his right eye during a period of deep hopelessness and suicidality when the patient could not resolve his anhedonia and social isolation. Pharmacotherapy and psychotherapy dramatically improved his disorder
A novel technique for the production of electrospun scaffolds with tailored three-dimensional micro-patterns employing additive manufacturing
Electrospinning is a common technique used to fabricate fibrous scaffolds for tissue engineering applications. There is now growing interest in assessing the ability of collector plate design to influence the patterning of the fibres during the electrospinning process. In this study, we investigate a novel method to generate hybrid electrospun scaffolds consisting of both random fibres and a defined three-dimensional (3D) micro-topography at the surface, using patterned resin formers produced by rapid prototyping (RP). Poly(D,L-lactide-co-glycolide) was electrospun onto the engineered RP surfaces and the ability of these formers to influence microfibre patterning in the resulting scaffolds visualized by scanning electron microscopy. Electrospun scaffolds with patterns mirroring the microstructures of the formers were successfully fabricated. The effect of the resulting fibre patterns and 3D geometries on mammalian cell adhesion and proliferation was investigated by seeding enhanced green fluorescent protein labelled 3T3 fibroblasts onto the scaffolds. Following 24 h and four days of culture, the seeded scaffolds were visually assessed by confocal macro- and microscopy. The patterning of the fibres guided initial cell adhesion to the scaffold with subsequent proliferation over the geometry resulting in the cells being held in a 3D micro-topography. Such patterning could be designed to replicate a specific in vivo structure; we use the dermal papillae as an exemplar here. In conclusion, a novel, versatile and scalable method to produce hybrid electrospun scaffolds has been developed. The 3D directional cues of the patterned fibres have been shown to influence cell behaviour and could be used to culture cells within a similar 3D micro-topography as experienced in vivo
Zinc and ageing: third Zincage conference
The importance of Zn for optimal functioning of the immune system and antioxidant stress response is well documented. Zn homeostasis influences development and function of immune cells, activity of stress-related and antioxidant proteins [metallothioneins (MT), chaperones, ApoJ, Poly(ADP-Ribose) polymerase-1 (PARP-1) and Methionione Sulfoxide Reductase (Msr), Superoxide Dismutase (SOD)], and helps to maintain genomic integrity and stability. During ageing, the intake of Zn decreases due to inadequate diet and/or intestinal malabsorption, contributing to frailty, general disability and increased incidence of age-related degenerative diseases (cancer, infections and atherosclerosis). Although many factors contributing to Zn deficiency have been identified, the biochemical markers of Zn deficiency as well as the possibility to achieve relevant health benefits through Zn supplementation in the elderly are still a matter for evaluation. Taking into account that Zn homeostasis is regulated by proteins and enzymes for which polymorphisms have been previously found to be associated with successful/unsuccessful ageing, genetic screening might be of added value in evaluating the individual response to Zn supplementation. Biochemical, immunological, dietary and genetic studies aimed at understanding the impact of Zn in healthy ageing, the effect of Zn supplementation in the elderly and finally formulating a rationale for the promotion of correct Zn supplementation were discussed at the international Zincage conference held in Ancona in January 2007
Alcohol and fatal life trajectories in Russia: understanding narrative accounts of premature male death in the family
Background: In the post-Soviet period, Russian working-age men have suffered unusually high mortality rates. Earlier quantitative work found that part of this is attributable to hazardous and harmful patterns of alcohol consumption, which increased in the period of transition at a time of massive social and economic disruption and uncertainty. However, there has been very little work done to document and understand in detail the downward life trajectories of individual men who died prematurely from alcohol-related conditions. Building on an earlier case-control study, this unique qualitative study investigates the perceived interplay between men's drinking careers, their employment and family history, health and eventual death.Methods: In-depth interviews were conducted with close relatives (most often the widow) of 19 men who died between 2003 and 2005 aged 25-54 years whose close relatives reported that alcohol contributed to their death. The study was conducted in a typical medium-sized Russian city. The relative's accounts were analysed using thematic content analysis.Results: The accounts describe how hazardous drinking both contributed to serious employment, family and health problems, and was simultaneously used as a coping mechanism to deal with life crises and a decline in social status. The interviews highlighted the importance of the workplace and employment status for shaping men's drinking patterns. Common themes emerged around a culture of drinking in the workplace, peer pressure from colleagues to drink, use of alcohol as remuneration, consuming non-beverage alcohols,Russian-specific drinking patterns, attitudes to treatment, and passive attitudes towards health and drinking.Conclusions: The study provides a unique insight into the personal decline that lies behind the extremely high working-age mortality due to heavy drinking in Russia, and highlights how health status and hazardous drinking are often closely intertwined with economic and social functioning. Descriptions of the development of drinking careers, hazardous drinking patterns and treatment experiences can be used to plan effective interventions relevant in the Russian context
Differences in gait patterns, pain, function and quality of life between males and females with knee osteoarthritis: a clinical trial
<p>Abstract</p> <p>Background</p> <p>The aim of this study was to gain a deeper understanding of the gender differences in knee osteoarthritis (OA) by evaluating the differences in gait spatio-temporal parameters and the differences in pain, quality of life and function between males and females suffering from knee OA.</p> <p>Methods</p> <p>49 males and 85 females suffering from bilateral medial compartment knee OA participated in this study. Each patient underwent a computerized gait test and completed the WOMAC questionnaire and the SF-36 health survey. Independent t-tests were performed to examine the differences between males and females in age, BMI, spatio-temporal parameters, the WOMAC questionnaire and the SF-36 health survey.</p> <p>Results</p> <p>Males and females had different gait patterns. Although males and females walked at the same walking speed, cadence and step length, they presented significant differences in the gait cycle phases. Males walked with a smaller stance and double limb support, and with a larger swing and single limb support compared to females. In addition, males walked with a greater toe out angle compared to females. While significant differences were not found in the WOMAC subscales, females consistently reported higher levels of pain and disability.</p> <p>Conclusion</p> <p>The spatio-temporal differences between genders may suggest underlying differences in the gait strategies adopted by males and females in order to reduce pain and cope with the loads acting on their affected joints, two key aspects of knee OA. These gender effects should therefore be taken into consideration when evaluating patients with knee OA.</p> <p>Trial Registration</p> <p>The study is registered in the NIH clinical trial registration, protocol No. NCT00599729.</p
Surgical techniques for the treatment of ankyloglossia in children: a case series
This paper reports a series of clinical cases of ankyloglossia in children, which were approached by different techniques: frenotomy and frenectomy with the use of one hemostat, two hemostats, a groove director or laser. Information on the indications, contraindications, advantages and disadvantages of the techniques was also presented. Children diagnosed with ankyloglossia were subjected to different surgical procedures. The choice of the techniques was based on the age of the patient, length of the frenulum and availability of the instruments and equipment. All the techniques presented are successful for the treatment of ankyloglossia and require a skilled professional. Laser may be considered a simple and safe alternative for children while reducing the amount of local anesthetics needed, the bleeding and the chances of infection, swelling and discomfort
Rural–Urban Migration and Experience of Childhood Abuse in the Young Thai Population
Evidence suggests that certain migrant populations are at increased risk of abusive behaviors. It is unclear whether this may also apply to Thai rural–urban migrants, who may experience higher levels of psychosocial adversities than the population at large. The study aims to examine the association between migration status and the history of childhood sexual, physical, and emotional abuse among young Thai people in an urban community. A population-based cross-sectional survey was conducted in Northern Bangkok on a representative sample of 1052 young residents, aged 16–25 years. Data were obtained concerning: 1) exposures—migration (defined as an occasion when a young person, born in a more rural area moves for the first time into Greater Bangkok) and age at migration. 2) outcomes—child abuse experiences were assessed with an anonymous self report adapted from the Conflict Tactics Scales (CTS). There were 8.4%. 16.6% and 56.0% reporting sexual, physical, and emotional abuse, respectively. Forty six percent of adolescents had migrated from rural areas to Bangkok, mostly independently at the age of 15 or after to seek work. Although there were trends towards higher prevalences of the three categories of abuse among early migrants, who moved to Bangkok before the age of 15, being early migrants was independently associated with experiences of physical abuse (OR 1.9 95%CI 1.1–3.2) and emotional abuse (OR 2.0, 95%CI 1.3–3.0) only. Our results suggest that rural–urban migration at an early age may place children at higher risk of physical and emotional abuse. This may have policy implications for the prevention of childhood abuse particularly among young people on the move
An interaction between Nrf2 polymorphisms and smoking status affects annual decline in FEV1: a longitudinal retrospective cohort study
<p>Abstract</p> <p>Background</p> <p>An Nrf2-dependent response is a central protective mechanism against oxidative stress. We propose that particular genetic variants of the <it>Nrf2 </it>gene may be associated with a rapid forced expiratory volume in one second (FEV<sub>1</sub>) decline induced by cigarette smoking.</p> <p>Methods</p> <p>We conducted a retrospective cohort study of 915 Japanese from a general population. Values of annual decline in FEV<sub>1 </sub>were computed for each individual using a linear mixed-effect model. Multiple clinical characteristics were assessed to identify associations with annual FEV<sub>1 </sub>decline. Tag single-nucleotide polymorphisms (SNPs) in the <it>Nrf2 </it>gene (rs2001350, rs6726395, rs1962142, rs2364722) and one functional SNP (rs6721961) in the <it>Nrf2 </it>promoter region were genotyped to assess interactions between the <it>Nrf2 </it>polymorphisms and smoking status on annual FEV<sub>1 </sub>decline.</p> <p>Results</p> <p>Annual FEV<sub>1 </sub>decline was associated with smoking behavior and inversely correlated with FEV<sub>1</sub>/FVC and FEV<sub>1 </sub>% predicted. The mean annual FEV<sub>1 </sub>declines in individuals with rs6726395 G/G, G/A, or A/A were 26.2, 22.3, and 20.8 mL/year, respectively, and differences in these means were statistically significant (p<sub>corr </sub>= 0.016). We also found a significant interaction between rs6726395 genotype and smoking status on the FEV<sub>1 </sub>decline (p for interaction = 0.011). The haplotype rs2001350T/rs6726395A/rs1962142A/rs2364722A/rs6721961T was associated with lower annual decline in FEV<sub>1 </sub>(p = 0.004).</p> <p>Conclusions</p> <p>This study indicated that an Nrf2-dependent response to exogenous stimuli may affect annual FEV<sub>1 </sub>decline in the general population. It appears that the genetic influence of <it>Nrf2 </it>is modified by smoking status, suggesting the presence of a gene-environment interaction in accelerated decline in FEV<sub>1</sub>.</p
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