230 research outputs found
ARES. III. Unveiling the Two Faces of KELT-7 b with HST WFC3*
We present the analysis of the hot-Jupiter KELT-7 b using transmission and emission spectroscopy from the Hubble Space Telescope, both taken with the Wide Field Camera 3. Our study uncovers a rich transmission spectrum that is consistent with a cloud-free atmosphere and suggests the presence of H_{2}O and H^{−}. In contrast, the extracted emission spectrum does not contain strong absorption features and, although it is not consistent with a simple blackbody, it can be explained by a varying temperature–pressure profile, collision induced absorption, and H^{-}. KELT-7 b had also been studied with other space-based instruments and we explore the effects of introducing these additional data sets. Further observations with Hubble, or the next generation of space-based telescopes, are needed to allow for the optical opacity source in transmission to be confirmed and for molecular features to be disentangled in emission
Chromosomal radiosensitivity in head and neck cancer patients: evidence for genetic predisposition?
The association between chromosomal radiosensitivity and genetic predisposition to head and neck cancer was investigated in this study. In all, 101 head and neck cancer patients and 75 healthy control individuals were included in the study. The G2 assay was used to measure chromosomal radiosensitivity. The results demonstrated that head and neck cancer patients had a statistically higher number of radiation-induced chromatid breaks than controls, with mean values of 1.23 and 1.10 breaks per cell, respectively (P<0.001). Using the 90th percentile of the G2 scores of the healthy individuals as a cutoff value for chromosomal radiosensitivity, 26% of the cancer patients were radiosensitive compared with 9% of the healthy controls (P=0.008). The mean number of radiation-induced chromatid breaks and the proportion of radiosensitive individuals were highest for oral cavity cancer patients (1.26 breaks per cell, 38%) and pharynx cancer patients (1.27 breaks per cell, 35%). The difference between patients and controls was most pronounced in the lower age group (⩽50 years, 1.32 breaks per cell, 38%) and in the non- and light smoking patient group (⩽10 pack-years, 1.28 breaks per cell, 46%). In conclusion, enhanced chromosomal radiosensitivity is a marker of genetic predisposition to head and neck cancer, and the genetic contribution is highest for oral cavity and pharynx cancer patients and for early onset and non- and light smoking patients
Availability of copper from phytoplankton and water for the bivalveMacoma balthica. II. Uptake and elimination from64Cu-labelled diatoms and water
Non-participation in population-based disease prevention programs in general practice
<p>Abstract</p> <p>Background</p> <p>The number of people with a chronic disease will strongly increase in the next decades. Therefore, prevention of disease becomes increasingly important. The aim of this systematic review was to identify factors that negatively influence participation in population-based disease prevention programs in General Practice and to establish whether the program type is related to non-participation levels.</p> <p>Methods</p> <p>We conducted a systematic review in Pubmed, EMBASE, CINAHL and PsycINFO, covering 2000 through July 6th 2012, to identify publications including information about characteristics of non-participants or reasons for non-participation in population-based disease prevention programs in General Practice.</p> <p>Results</p> <p>A total of 24 original studies met our criteria, seven of which focused on vaccination, eleven on screening aimed at early detection of disease, and six on screening aimed at identifying high risk of a disease, targeting a variety of diseases and conditions. Lack of personal relevance of the program, younger age, higher social deprivation and former non-participation were related to actual non-participation. No differences were found in non-participation levels or factors related to non-participation between the three program types. The large variation in non-participation levels within the program types may be partly due to differences in recruitment strategies, with more active, personalized strategies resulting in higher participation levels compared to an invitation letter.</p> <p>Conclusions</p> <p>There is still much to be gained by tailoring strategies to improve participation in those who are less likely to do so, namely younger individuals, those living in a deprived area and former non-participants. Participation may increase by applying more active recruitment strategies.</p
Discovery and Creation: Alternative Theories of Entrepreneurial Action
As oportunidades empreendedoras existem, independentemente, das percepções dos empreendedores, esperando apenas para serem descobertas? Ou, estas oportunidades são criadas pelas ações dos empreendedores? Duas teorias, internamente, consistentes com as oportunidades empreendedoras são: teoria da criação e teoria da descoberta- as quais serão descritas. Enquanto, será sempre possível, descrever a formação de uma oportunidade particular, como exemplo, de um processo da descoberta ou da criação de oportunidade, estas duas teorias têm implicações importantes para a eficácia de uma variedade ampla de ações empreendedoras em contextos diferentes. As implicações destas teorias para sete destas ações serão descritas, acompanhadas de uma discussão sobre algumas das implicações teóricas mais amplas destas duas teorias para os campos do empreendimento e do gerenciamento estratégico
‘No Time to be Lost!’: Ethical Considerations on Consent for Inclusion in Emergency Pharmacological Research in Severe Traumatic Brain Injury in the European Union
Severe Traumatic Brain Injury (TBI) remains a major cause of death and disability afflicting mostly young adult males and elderly people, resulting in high economic costs to society. Therapeutic approaches focus on reducing the risk on secondary brain injury. Specific ethical issues pertaining in clinical testing of pharmacological neuroprotective agents in TBI include the emergency nature of the research, the incapacity of the patients to informed consent before inclusion, short therapeutic time windows, and a risk-benefit ratio based on concept that in relation to the severity of the trauma, significant adverse side effects may be acceptable for possible beneficial treatments. Randomized controlled phase III trials investigating the safety and efficacy of agents in TBI with promising benefit, conducted in acute emergency situations with short therapeutic time windows, should allow randomization under deferred consent or waiver of consent. Making progress in knowledge of treatment in acute neurological and other intensive care conditions is only possible if national regulations and legislations allow waiver of consent or deferred consent for clinical trials
Pancreatic (pro)enzymes treatment suppresses BXPC-3 pancreatic Cancer Stem Cell subpopulation and impairs tumour engrafting
Cancer stem cells (CSCs) subpopulation within the tumour is responsible for metastasis and cancer
relapse. Here we investigate in vitro and in vivo the effects of a pancreatic (pro)enzyme mixture
composed of Chymotrypsinogen and Trypsinogen (PRP) on CSCs derived from a human pancreatic
cell line, BxPC3. Exposure of pancreatic CSCs spheres to PRP resulted in a significant decrease of
ALDEFLUOR and specific pancreatic CSC markers (CD 326, CD 44 and CxCR4) signal tested by flow
cytometry, further CSCs markers expression was also analyzed by western and immunofluorescence
assays. PRP also inhibits primary and secondary sphere formation. Three RT2 Profiler PCR Arrays
were used to study gene expression regulation after PRP treatment and resulted in, (i) epithelialmesenchymal
transition (EMT) inhibition; (ii) CSCs related genes suppression; (iii) enhanced expression
of tumour suppressor genes; (iv) downregulation of migration and metastasis genes and (v) regulation
of MAP Kinase Signalling Pathway. Finally, in vivo anti-tumor xenograft studies demonstrated high
anti-tumour efficacy of PRP against tumours induced by BxPC3 human pancreatic CSCs. PRP impaired
engrafting of pancreatic CSC’s tumours in nude mice and displayed an antigrowth effect toward
initiated xenografts. We concluded that (pro)enzymes treatment is a valuable strategy to suppress the
CSC population in solid pancreatic tumours
Pollutant effects on genotoxic parameters and tumor-associated protein levels in adults: a cross sectional study
<p>Abstract</p> <p>Background</p> <p>This study intended to investigate whether residence in areas polluted by heavy industry, waste incineration, a high density of traffic and housing or intensive use of pesticides, could contribute to the high incidence of cancer observed in Flanders.</p> <p>Methods</p> <p>Subjects were 1583 residents aged 50–65 from 9 areas with different types of pollution. Cadmium, lead, p,p'-DDE, hexachlorobenzene, PCBs and dioxin-like activity (Calux test) were measured in blood, and cadmium, t,t'-muconic acid and 1-hydroxypyrene in urine. Effect biomarkers were prostate specific antigen, carcinoembryonic antigen and p53 protein serum levels, number of micronuclei per 1000 binucleated peripheral blood cells, DNA damage (comet assay) in peripheral blood cells and 8-hydroxy-deoxyguanosine in urine. Confounding factors were taken into account.</p> <p>Results</p> <p>Overall significant differences between areas were found for carcinoembryonic antigen, micronuclei, 8-hydroxy-deoxyguanosine and DNA damage. Compared to a rural area with mainly fruit production, effect biomarkers were often significantly elevated around waste incinerators, in the cities of Antwerp and Ghent, in industrial areas and also in other rural areas. Within an industrial area DNA strand break levels were almost three times higher close to industrial installations than 5 kilometres upwind of the main industrial installations (p < 0.0001). Positive exposure-effect relationships were found for carcinoembryonic antigen (urinary cadmium, t,t'-muconic acid, 1-hydroxypyrene and blood lead), micronuclei (PCB118), DNA damage (PCB118) and 8-hydroxy-deoxyguanosine (t,t'-muconic acid, 1-hydroxypyrene). Also, we found significant associations between values of PSA above the p90 and higher values of urinary cadmium, between values of p53 above the p90 and higher serum levels of p,p'-DDE, hexachlorobenzene and marker PCBs (PCB 138, 153 and 180) and between serum levels of p,p'-DDE above the p90 and higher serum values of carcinoembryonic antigen. Significant associations were also found between effect biomarkers and occupational or lifestyle parameters.</p> <p>Conclusion</p> <p>Levels of internal exposure, and residence near waste incinerators, in cities, or close to important industries, but not in areas with intensive use of pesticides, showed positive correlations with biomarkers associated with carcinogenesis and thus probably contribute to risk of cancer. In some rural areas, the levels of these biomarkers were not lower than in the rest of Flanders.</p
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