1,537 research outputs found
The Effect Of Alloy Compositions On The Microstructure And Mechanical Properties Of Ceramic Matrix Composite Formed By Combustion Synthesis
The purpose of this research was to investigate the effect of alloy compositions on the microstructure and mechanical properties of product form by combustion synthesis. The research was done using powder materials such as C, Al, and TiO2. Using a reaction equation of 3TiO2 + (4+X) Al + 3C → 3TiC + 2Al2O3 + (X)Al, the powders was balanced to form a mixture which subsequently compacted to form a pellet. The composition of mixture was varied with excess of Al from 20%, 40%, 60%, 80%, to 100%. The ignition of combustion synthesis was done using arch flame. The results of the research showed that the ignition and combustion synthesis were succesfully observed in the reacted products. Using XRD and SEM observations, it was shown that Al and Al2O3 are the dominant phases of the synthesized products. Meanwhile, the microhardness test showed that increasing the content of Al has reduced the hardness. The higher hardness was observed in the product with highest content of Al2O3. This research has shown that the aluminium alloyed with Al2O3 formed by combustion synthesis has significant influence on the mechanical properties of product, with a substantial increase in its hardness
Pengaruh Penambahan Teknik Relaksasi Progresif Pada Terapi Latihan Terhadap Penurunan Nyeri Post Section Caesarea Di Rumah Sakit Umum Daerah Dr. Moewardi
Latar Belakang: Nyeri merupakan salah satu permasalahan utama pada post
section caesarea, Nyeri harus ditangani sedini mungkin. Salah satu modalitas
fisioterapi pada penanganan nyeri adalah teknik relaksasi progresif dan terapi
latihan.
Tujuan Penelititan: Mengetahui pengaruh penambahan teknik relaksasi progresif
pada terapi latihan dan terapi latihan terhadap penurunan nyeri post section
caesarea serta mengetahui perbedaan pengaruh penambahan teknik relaksasi
progresif pada terapi latihan dan terapi latihan terhadap penurunan nyeri post
section caesarea.
Metode Penelitian: Penelitian ini merupakan quasi eksperimen. Pelaksanaan
penelitian dilakukan pada pasien post section caesarea sebanyak 77 orang yang
dibagi kedalam dua kelompok yaitu kelompok teknik relaksasi progresif dan
terapi latihan dan kelompok terapi latihan. Dosis latihan yang diberikan adalah
setiap hari selama masa perawatan, 2x8 setiap gerakkan pada terapi latihan dan 8-
10 detik tension pada teknik relaksasi progresif. Pengukuran nyeri menggunakan
Visual Analogue Scale (VAS) dengan desain penelitian pre-post test design
dengan analisis data menggunakan uji T-Test untuk kelompok perlakuan.
Hasil penelitian: Hasil penelitian menunjukkan ada pengaruh penambahan teknik
relaksasi progresif pada terapi latihan dan terapi latihan terhadap penurunan nyeri
post section caesarea (p=0.00) dan ada beda pengaruh antara penambahan teknik
relaksasi progresif pada dan terapi latihan terhadap penurunan nyeri post section
caesarea (p=0.00)
Kesimpulan: Ada pengaruh penambahan teknik relaksasi progresif pada terapi
latihan dan terapi latihan terhadap penurunan nyeri post sectionn caesarea dan
ada beda pengaruh antara penambahan teknik relaksasi progresif pada dan terapi
latihan terhadap penurunan nyeri post section caesarea
Soil methane sink capacity response to a long-term wildfire chronosequence in Northern Sweden
Boreal forests occupy nearly one fifth of the terrestrial land surface and are recognised as globally important regulators of carbon (C) cycling and greenhouse gas emissions. Carbon sequestration processes in these forests include assimilation of CO2 into biomass and subsequently into soil organic matter, and soil microbial oxidation of methane (CH4). In this study we explored how ecosystem retrogression, which drives vegetation change, regulates the important process of soil CH4 oxidation in boreal forests. We measured soil CH4 oxidation processes on a group of 30 forested islands in northern Sweden differing greatly in fire history, and collectively representing a retrogressive chronosequence, spanning 5000 years. Across these islands the build-up of soil organic matter was observed to increase with time since fire disturbance, with a significant correlation between greater humus depth and increased net soil CH4 oxidation rates. We suggest that this increase in net CH4 oxidation rates, in the absence of disturbance, results as deeper humus stores accumulate and provide niches for methanotrophs to thrive. By using this gradient we have discovered important regulatory controls on the stability of soil CH4 oxidation processes that could not have not been explored through shorter-term experiments. Our findings indicate that in the absence of human interventions such as fire suppression, and with increased wildfire frequency, the globally important boreal CH4 sink could be diminished
Therapeutic effects of the mitochondrial ROS-redox modulator KH176 in a mammalian model of Leigh Disease
Leigh Disease is a progressive neurometabolic disorder for which a clinical effective treatment is currently still lacking. Here, we report on the therapeutic efficacy of KH176, a new chemical entity derivative of Trolox, in Ndufs4 (-/-) mice, a mammalian model for Leigh Disease. Using in vivo brain diffusion tensor imaging, we show a loss of brain microstructural coherence in Ndufs4 (-/-) mice in the cerebral cortex, external capsule and cerebral peduncle. These findings are in line with the white matter diffusivity changes described in mitochondrial disease patients. Long-term KH176 treatment retained brain microstructural coherence in the external capsule in Ndufs4 (-/-) mice and normalized the increased lipid peroxidation in this area and the cerebral cortex. Furthermore, KH176 treatment was able to significantly improve rotarod and gait performance and reduced the degeneration of retinal ganglion cells in Ndufs4 (-/-) mice. These in vivo findings show that further development of KH176 as a potential treatment for mitochondrial disorders is worthwhile to pursue. Clinical trial studies to explore the potency, safety and efficacy of KH176 are ongoing
The Eyes Have It: Sex and Sexual Orientation Differences in Pupil Dilation Patterns
Recent research suggests profound sex and sexual orientation differences in sexual response. These results, however, are based on measures of genital arousal, which have potential limitations such as volunteer bias and differential measures for the sexes. The present study introduces a measure less affected by these limitations. We assessed the pupil dilation of 325 men and women of various sexual orientations to male and female erotic stimuli. Results supported hypotheses. In general, self-reported sexual orientation corresponded with pupil dilation to men and women. Among men, substantial dilation to both sexes was most common in bisexual-identified men. In contrast, among women, substantial dilation to both sexes was most common in heterosexual-identified women. Possible reasons for these differences are discussed. Because the measure of pupil dilation is less invasive than previous measures of sexual response, it allows for studying diverse age and cultural populations, usually not included in sexuality research
Emergency presentation of cancer and short-term mortality
Background:The short-term survival following a cancer diagnosis in England is lower than that in comparable countries, with the difference in excess mortality primarily occurring in the months immediately after diagnosis. We assess the impact of emergency presentation (EP) on the excess mortality in England over the course of the year following diagnosis. Methods:All colorectal and cervical cancers presenting in England and all breast, lung, and prostate cancers in the East of England in 2006-2008 are included. The variation in the likelihood of EP with age, stage, sex, co-morbidity, and income deprivation is modelled. The excess mortality over 0-1, 1-3, 3-6, and 6-12 months after diagnosis and its dependence on these case-mix factors and presentation route is then examined. Results:More advanced stage and older age are predictive of EP, as to a lesser extent are co-morbidity, higher income deprivation, and female sex. In the first month after diagnosis, we observe case-mix-adjusted excess mortality rate ratios of 7.5 (cervical), 5.9 (colorectal), 11.7 (breast ), 4.0 (lung), and 20.8 (prostate) for EP compared with non-EP. Conclusion:Individuals who present as an emergency experience high short-term mortality in all cancer types examined compared with non-EPs. This is partly a case-mix effect but EP remains predictive of short-term mortality even when age, stage, and co-morbidity are accounted for
Total plaque area and plaque echogenicity are novel measures of subclinical atherosclerosis in patients with systemic lupus erythematosus
OBJECTIVES: Patients with systemic lupus erythematosus (SLE) have an increased risk of developing cardiovascular disease (CVD). Multiple studies have shown that these patients have increased numbers of carotid plaques and greater intima-media thickness (IMT) than healthy controls. Measures such as total plaque area (TPA) and plaque echogenicity may be more sensitive and more relevant to cardiovascular risk than presence of plaque and IMT alone. Our objective was to produce the first report of TPA and echogenicity in a population of. PATIENT: s with SLE. METHODS: One hundred patients with SLE and no history of clinical CVD were recruited. Clinical, serological and treatment variables were recorded and serum was tested for antibodies to apolipoprotein A-1 and high-density lipoprotein. Both carotid and both femoral artery bifurcations of each patient were scanned to determine IMT, TPA and echogenicity of plaques. Univariable and multivariable statistical analyses were carried out to define factors associated with each of these outcomes. RESULTS: Thirty-six patients had carotid and/or femoral plaque. Increasing age was associated with presence of plaque and increased IMT. Triglyceride levels were associated with presence of plaque. Mean (SD) TPA was 60.8 (41. 6) mm2. Patients taking prednisolone had higher TPA. Most plaques were echolucent but increased echogenicity was associated with prednisolone therapy and persistent disease activity. CONCLUSION: TPA and plaque echogenicity in patients with SLE are associated with different factors than those associated with presence of plaque and IMT. Longitudinal studies may show whether these outcome measures add value in the management of cardiovascular risk in SLE
Breast cancer in systemic lupus
OBJECTIVE: There is a decreased breast cancer risk in systemic lupus erythematosus (SLE) versus the general population. We assessed a large sample of SLE patients, evaluating demographic and clinical characteristics and breast cancer risk. METHODS: We performed case-cohort analyses within a multi-center international SLE sample. We calculated the breast cancer hazard ratio (HR) in female SLE patients, relative to demographics, reproductive history, family history of breast cancer, and time-dependent measures of anti-dsDNA positivity, cumulative disease activity, and drugs, adjusted for SLE duration. RESULTS: There were 86 SLE breast cancers and 4498 female SLE cancer-free controls. Patients were followed on average for 7.6 years. Versus controls, SLE breast cancer cases tended to be white and older. Breast cancer cases were similar to controls regarding anti-dsDNA positivity, disease activity, and most drug exposures over time. In univariate and multivariate models, the principal factor associated with breast cancers was older age at cohort entry. CONCLUSIONS: There was little evidence that breast cancer risk in this SLE sample was strongly driven by any of the clinical factors that we studied. Further search for factors that determine the lower risk of breast cancer in SLE may be warranted
The interactive effects of arbuscular mycorrhiza and plant growth-promoting rhizobacteria synergistically enhance host plant defences against pathogens
Belowground interactions between plant roots, mycorrhizal fungi and plant growth-promoting rhizobacteria (PGPR) can improve plant health via enhanced nutrient acquisition and priming of the plant immune system. Two wheat cultivars differing in their ability to form mycorrhiza were (co)inoculated with the mycorrhizal fungus Rhizophagus irregularis and the rhizobacterial strain Pseudomonas putida KT2440. The cultivar with high mycorrhizal compatibility supported higher levels of rhizobacterial colonization than the low compatibility cultivar. Those levels were augmented by mycorrhizal infection. Conversely, rhizobacterial colonization of the low compatibility cultivar was reduced by mycorrhizal arbuscule formation. Single inoculations with R. irregularis or P. putida had differential growth effects on both cultivars. Furthermore, while both cultivars developed systemic priming of chitosan-induced callose after single inoculations with R. irregularis or P. putida, only the cultivar with high mycorrhizal compatibility showed a synergistic increase in callose responsiveness following co-inoculation with both microbes. Our results show that multilateral interactions between roots, mycorrhizal fungi and PGPR can have synergistic effects on growth and systemic priming of wheat
Cooperation of breast cancer proteins PALB2 and piccolo BRCA2 in stimulating homologous recombination.
Inherited mutations in human PALB2 are associated with a predisposition to breast and pancreatic cancers. PALB2's tumor-suppressing effect is thought to be based on its ability to facilitate BRCA2's function in homologous recombination. However, the biochemical properties of PALB2 are unknown. Here we show that human PALB2 binds DNA, preferentially D-loop structures, and directly interacts with the RAD51 recombinase to stimulate strand invasion, a vital step of homologous recombination. This stimulation occurs through reinforcing biochemical mechanisms, as PALB2 alleviates inhibition by RPA and stabilizes the RAD51 filament. Moreover, PALB2 can function synergistically with a BRCA2 chimera (termed piccolo, or piBRCA2) to further promote strand invasion. Finally, we show that PALB2-deficient cells are sensitive to PARP inhibitors. Our studies provide the first biochemical insights into PALB2's function with piBRCA2 as a mediator of homologous recombination in DNA double-strand break repair
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