119 research outputs found

    Pengaruh Preheating Pada Cetakan Permanen Terhadap Distribusi Kekerasan Grinding Cyl Dengan Material Besi Cor Kelabu

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    The purpose of this research is to know the influence of preheating on permanent mold cast iron ductile temperature physical properties of 4000C against mechanicaland grey cast iron. The freezing gray cast iron is monitored with CE and hardened after going throuht some test of metal, among other: metalografi test, hardness and chemical composition test. The research of using grey cast iron material. Of specimens this grey cast iron to be determined 4-point test to find out the physical and mechanical properties in some predetermined point. Testing chemical composition using standard JIS. The test result show the influence of preheating with temperature 400oC on permanent mold cast iron ductile cast iron grey material. Test result of specimen that are part of microstructure in hardness test visible graphite and sementite and hardness test results of specimens at the A= 101,09, 90,15, 91,27, 87,60 and 86,09 HRB.  B= 86,60, 90,44, 90,03, 92,97 and 88,60 HRB. C= 92.07, 96.20, 96.66, 88.38 and 90.83 HRB. and D= 102. 58, 92.85, 92.28, 93.81 and 94.50 HRB, and price the highest hardness in C3 of 96,66 HRB, while the lowest rates of hardness in parts of the A1 of 82,54 HRB. On the results of testing metal foundries use CE metres obtained initial temperature of 1260.30C, 1121.30C, liquid temperature the temperature of the solid 1118.70C so that’s earned value CEL = 4,47%, C = 3,98%, and Si = 1,86% where the iron starts but still solid red until the temperature of 10600C and harden within 180 seconds, while the chemical composition test results in the form of solid or solid follows: 93,26% Fe, C 3,06%, Si 1,80% and other elements of under 1%. On the results of the test chemical composition there are 20 chemical elements with different levels and observation of microstructure discover the structure of graphite and cementite. From thr results of these tests can noted that is formed is a grey cast iron FC 150 with JIS Standards

    Dose escalation of a curcuminoid formulation

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    BACKGROUND: Curcumin is the major yellow pigment extracted from turmeric, a commonly-used spice in India and Southeast Asia that has broad anticarcinogenic and cancer chemopreventive potential. However, few systematic studies of curcumin's pharmacology and toxicology in humans have been performed. METHODS: A dose escalation study was conducted to determine the maximum tolerated dose and safety of a single dose of standardized powder extract, uniformly milled curcumin (C(3 )Complex™, Sabinsa Corporation). Healthy volunteers were administered escalating doses from 500 to 12,000 mg. RESULTS: Seven of twenty-four subjects (30%) experienced only minimal toxicity that did not appear to be dose-related. No curcumin was detected in the serum of subjects administered 500, 1,000, 2,000, 4,000, 6,000 or 8,000 mg. Low levels of curcumin were detected in two subjects administered 10,000 or 12,000 mg. CONCLUSION: The tolerance of curcumin in high single oral doses appears to be excellent. Given that achieving systemic bioavailability of curcumin or its metabolites may not be essential for colorectal cancer chemoprevention, these findings warrant further investigation for its utility as a long-term chemopreventive agent

    Health profiles of 996 melanoma survivors: the M. D. Anderson experience

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    BACKGROUND: The incidence and survival of melanoma are increasing, but little is known about its long-term health effects in adult survivors. METHODS: A health survey was available from 996 melanoma survivors (577 treated with surgery alone, and 391 with combined treatments). Their medical/physiologic and psychosocial responses were analyzed and compared with those of the survivors from other cancers. RESULTS: The melanoma survivors were 44.8 ± 12.8 years of age at diagnosis (significantly younger than the survivors of other cancers) and 63.7 ± 12.8 years at survey. Melanoma survivors were less likely to report that cancer had affected their health than survivors of other cancers (15.8% vs. 34.9%). The 577 individuals treated with surgery alone reported arthritis/osteoporosis, cataracts, and heart problems most frequently (less often than survivors of other cancers). The 391 individuals who had undergone combined treatments reported circulation problems and kidney problems generally as often as survivors of other cancers. Health problems were not associated with number of decades since diagnosis but with age at diagnosis, treatment modality, and family relationships. CONCLUSION: We present information from a large cohort of long-term survivors of melanoma. As a group, they were less likely to report that cancer had affected their overall health than survivors of other cancers; a number of disease related and psychosocial factors appear to influence their health profiles

    Modelling entomological-climatic interactions of Plasmodium falciparum malaria transmission in two Colombian endemic-regions: contributions to a National Malaria Early Warning System

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    BACKGROUND: Malaria has recently re-emerged as a public health burden in Colombia. Although the problem seems to be climate-driven, there remain significant gaps of knowledge in the understanding of the complexity of malaria transmission, which have motivated attempts to develop a comprehensive model. METHODS: The mathematical tool was applied to represent Plasmodium falciparum malaria transmission in two endemic-areas. Entomological exogenous variables were estimated through field campaigns and laboratory experiments. Availability of breeding places was included towards representing fluctuations in vector densities. Diverse scenarios, sensitivity analyses and instabilities cases were considered during experimentation-validation process. RESULTS: Correlation coefficients and mean square errors between observed and modelled incidences reached 0.897–0.668 (P > 0.95) and 0.0002–0.0005, respectively. Temperature became the most relevant climatic parameter driving the final incidence. Accordingly, malaria outbreaks are possible during the favourable epochs following the onset of El Niño warm events. Sporogonic and gonotrophic cycles showed to be the entomological key-variables controlling the transmission potential of mosquitoes' population. Simulation results also showed that seasonality of vector density becomes an important factor towards understanding disease transmission. CONCLUSION: The model constitutes a promising tool to deepen the understanding of the multiple interactions related to malaria transmission conducive to outbreaks. In the foreseeable future it could be implemented as a tool to diagnose possible dynamical patterns of malaria incidence under several scenarios, as well as a decision-making tool for the early detection and control of outbreaks. The model will be also able to be merged with forecasts of El Niño events to provide a National Malaria Early Warning System

    Hyperoxic Treatment Induces Mesenchymal-to-Epithelial Transition in a Rat Adenocarcinoma Model

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    Tumor hypoxia is relevant for tumor growth, metabolism and epithelial-to-mesenchymal transition (EMT). We report that hyperbaric oxygen (HBO) treatment induced mesenchymal-to-epithelial transition (MET) in a dimetyl-α-benzantracene induced mammary rat adenocarcinoma model, and the MET was associated with extensive coordinated gene expression changes and less aggressive tumors. One group of tumor bearing rats was exposed to HBO (2 bar, pO2 = 2 bar, 4 exposures à 90 minutes), whereas the control group was housed under normal atmosphere (1 bar, pO2 = 0.2 bar). Treatment effects were determined by assessment of tumor growth, tumor vascularisation, tumor cell proliferation, cell death, collagen fibrils and gene expression profile. Tumor growth was significantly reduced (∼16%) after HBO treatment compared to day 1 levels, whereas control tumors increased almost 100% in volume. Significant decreases in tumor cell proliferation, tumor blood vessels and collagen fibrils, together with an increase in cell death, are consistent with tumor growth reduction and tumor stroma influence after hyperoxic treatment. Gene expression profiling showed that HBO induced MET. In conclusion, hyperoxia induced MET with coordinated expression of gene modules involved in cell junctions and attachments together with a shift towards non-tumorigenic metabolism. This leads to more differentiated and less aggressive tumors, and indicates that oxygen per se might be an important factor in the “switches” of EMT and MET in vivo. HBO treatment also attenuated tumor growth and changed tumor stroma, by targeting the vascular system, having anti-proliferative and pro-apoptotic effects

    DNA barcoding reveals both known and novel taxa in the Albitarsis Group (Anopheles: Nyssorhynchus) of Neotropical malaria vectors

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    <p>Abstract</p> <p>Background</p> <p>Mosquitoes belonging to the Albitarsis Group (<it>Anopheles</it>: <it>Nyssorhynchus</it>) are of importance as malaria vectors across the Neotropics. The Group currently comprises six known species, and recent studies have indicated further hidden biodiversity within the Group. DNA barcoding has been proposed as a highly useful tool for species recognition, although its discriminatory utility has not been verified in closely related taxa across a wide geographic distribution.</p> <p>Methods</p> <p>DNA barcodes (658 bp of the mtDNA <it>Cytochrome c Oxidase </it>- <it>COI</it>) were generated for 565 <it>An. albitarsis </it>s.l. collected in Argentina, Brazil, Colombia, Paraguay, Trinidad and Venezuela over the past twenty years, including specimens from type series and type localities. Here we test the utility of currently advocated barcoding methodologies, including the Kimura-two-parameter distance model (K2P) and Neighbor-joining analysis (NJ), for determining species delineation within mosquitoes of the Neotropical Albitarsis Group of malaria vectors (<it>Anopheles</it>: <it>Nyssorhynchus</it>), and compare results with Bayesian analysis.</p> <p>Results</p> <p>Species delineation through barcoding analysis and Bayesian phylogenetic analysis, fully concur. Analysis of 565 sequences (302 unique haplotypes) resolved nine NJ tree clusters, with less than 2% intra-node variation. Mean intra-specific variation (K2P) was 0.009 (range 0.002 - 0.014), whereas mean inter-specific divergence were several-fold higher at 0.041 (0.020 - 0.056), supporting the reported "barcoding gap". These results show full support for separate species status of the six known species in the Albitarsis Group (<it>An. albitarsis </it>s.s., <it>An. albitarsis </it>F, <it>An. deaneorum</it>, <it>An. janconnae</it>, <it>An. marajoara </it>and <it>An. oryzalimnetes</it>), and also support species level status for two previously detected lineages - <it>An. albitarsis </it>G &<it>An. albitarsis </it>I (designated herein). In addition, we highlight the presence of a unique mitochondrial lineage close to <it>An. deaneorum </it>and <it>An. marajoara </it>(<it>An. albitarsis </it>H) from Rondônia and Mato Grosso in southwestern Brazil. Further integrated studies are required to confirm the status of this lineage.</p> <p>Conclusions</p> <p>DNA barcoding provides a reliable means of identifying both known and undiscovered biodiversity within the closely related taxa of the Albitarsis Group. We advocate its usage in future studies to elucidate the vector competence and respective distributions of all eight species in the Albitarsis Group and the novel mitochondrial lineage (<it>An. albitarsis </it>H) recovered in this study.</p

    Breast cancer risk factors in relation to breast density (United States)

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    OBJECTIVES: Evaluate known breast cancer risk factors in relation to breast density. METHODS: We examined factors in relation to breast density in 144,018 New Hampshire (NH) women with at least one mammogram recorded in a statewide mammography registry. Mammographic breast density was measured by radiologists using the BI-RADS classification; risk factors of interest were obtained from patient intake forms and questionnaires. RESULTS: Initial analyses showed a strong inverse influence of age and body mass index (BMI) on breast density. In addition, women with late age at menarche, late age at first birth, premenopausal women, and those currently using hormone therapy (HT) tended to have higher breast density, while those with greater parity tended to have less dense breasts. Analyses stratified on age and BMI suggested interactions, which were formally assessed in a multivariable model. The impact of current HT use, relative to nonuse, differed across age groups, with an inverse association in younger women, and a positive association in older women (p < 0.0001 for the interaction). The positive effects of age at menarche and age at first birth, and the inverse influence of parity were less apparent in women with low BMI than in those with high BMI (p = 0.04, p < 0.0001 and p = 0.01, respectively, for the interactions). We also noted stronger positive effects for age at first birth in postmenopausal women (p = 0.004 for the interaction). The multivariable model indicated a slight positive influence of family history of breast cancer. CONCLUSIONS: The influence of age at menarche and reproductive factors on breast density is less evident in women with high BMI. Density is reduced in young women using HT, but increased in HT users of age 50 or more

    Epidemiological and some clinical characteristics of neuroblastoma in Mexican children (1996–2005)

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    <p>Abstract</p> <p>Background</p> <p>Neuroblastoma (NB) is the principal tumor of the sympathetic nervous system in children under one year of age. The incidence in developed countries is greater than that in developing countries. The aim of this article is to present the epidemiological and some clinical characteristics of Mexican children with NB.</p> <p>Methods</p> <p>A population-based, prolective study, with data obtained from the Childhood Cancer Registry of the Instituto Mexicano de Seguro Social. Statistical analysis: The simple frequencies of the variables of the study and the annual average incidence (per 1,000,000 children/years) by age and sex were obtained. The trend was evaluated by calculating the annual percentage of change. The curves of Kaplan-Meyer were employed for the survival rate and the log-rank test was used to compare the curves.</p> <p>Results</p> <p>Of a total of 2,758 children with cancer registered during the period from 1996–2005, 72 (2.6%) were identified as having Group IV, defined according to the International Classification of Childhood Cancer. The incidence for NB was 3.8 per 1,000,000 children/year; NB was highest in the group of children under one year of age, followed by the group of children between the ages 1–4 years (18.5 and 5.4 per 1,000,000 children/years, respectively). The male/female ratio was 1.1 and there was no trend toward an increase. The time of diagnosis was 26 days (median), but varied according to the stage at diagnosis. Stages III and IV were presented in 88% of the cases. There was no association between the stage, the age at time of diagnosis, or the histological pattern. The overall five-year survival rate was 64%; the patients with stage I, II, III, or IVs did not die; and the five-year survival rate of cases in Stage IV was 40%.</p> <p>Conclusion</p> <p>It is possible that the low incidence of neuroblastoma in Mexican children is due to the difficulty in diagnosing the cases with the best prognosis, some of which could have had spontaneous regression. There was no trend to an increase; the majority of the cases were diagnosed in the advanced stages; and the overall five-years survival rate was similar to that for developed countries.</p

    Analysis of CpG methylation sites and CGI among human papillomavirus DNA genomes

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    <p>Abstract</p> <p>Background</p> <p>The Human Papillomavirus (HPV) genome is divided into early and late coding sequences, including 8 open reading frames (ORFs) and a regulatory region (LCR). Viral gene expression may be regulated through epigenetic mechanisms, including cytosine methylation at CpG dinucleotides. We have analyzed the distribution of CpG sites and CpG islands/clusters (CGI) among 92 different HPV genomes grouped in function of their preferential tropism: cutaneous or mucosal. We calculated the proportion of CpG sites (PCS) for each ORF and calculated the expected CpG values for each viral type.</p> <p>Results</p> <p>CpGs are underrepresented in viral genomes. We found a positive correlation between CpG observed and expected values, with mucosal high-risk (HR) virus types showing the smallest O/E ratios. The ranges of the PCS were similar for most genomic regions except <it>E4</it>, where the majority of CpGs are found within islands/clusters. At least one CGI belongs to each <it>E2/E4 </it>region. We found positive correlations between PCS for each viral ORF when compared with the others, except for the LCR against four ORFs and <it>E6 </it>against three other ORFs. The distribution of CpG islands/clusters among HPV groups is heterogeneous and mucosal HR-HPV types exhibit both lower number and shorter island sizes compared to cutaneous and mucosal Low-risk (LR) HPVs (all of them significantly different).</p> <p>Conclusions</p> <p>There is a difference between viral and cellular CpG underrepresentation. There are significant correlations between complete genome PCS and a lack of correlations between several genomic region pairs, especially those involving LCR and <it>E6</it>. <it>L2 </it>and <it>L1 </it>ORF behavior is opposite to that of oncogenes <it>E6 </it>and <it>E7</it>. The first pair possesses relatively low numbers of CpG sites clustered in CGIs while the oncogenes possess a relatively high number of CpG sites not associated to CGIs. In all HPVs, <it>E2/E4 </it>is the only region with at least one CGI and shows a higher content of CpG sites in every HPV type with an identified <it>E4</it>. The mucosal HR-HPVs show either the shortest CGI size, followed by the mucosal LR-HPVs and lastly by the cutaneous viral subgroup, and a trend to the lowest CGI number, followed by the cutaneous viral subgroup and lastly by the mucosal LR-HPVs.</p
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