Petrological Insights into Shifts in Eruptive Styles at Volcán Llaima (Chile)

Tephra and lava pairs from two summit eruptions (ad 2008 and 1957) and a flank fissure eruption (∼ ad 1850) are compared in terms of textures, phenocryst contents, and mineral zoning patterns to shed light on processes responsible for the shifts in eruption style during typical eruptive episodes at Volcán Llaima (Andean Southern Volcanic Zone, Chile). The mineralogy and whole-rock compositions of tephra and lavas are similar within eruptive episodes, suggesting a common magma reservoir for Strombolian paroxysms and lava effusion. The zoning profiles and textures of plagioclase record successive and discrete intrusions of volatile-rich mafic magma accompanied by mixing of these recharge magmas with the resident basaltic-andesitic crystal mushes that are commonly present at shallow levels in the Llaima system. Each recharge event destabilizes the plagioclase in equilibrium with the resident crystal mush melt and stabilizes relatively An-rich plagioclase, as is recorded by the numerous resorption zones. Lavas typically have ∼15-20 vol. % more phenocrysts than the tephra. Differences in plagioclase and olivine textures and zoning, combined with different phenocryst contents, indicate that a greater volume fraction of recharge magma is present in the explosively erupted magma than in subsequent effusively erupted magma. We propose that Strombolian paroxysms at Volcán Llaima are triggered by interactions with large volume fractions of recharge magma, which decrease the bulk viscosity and increase the volatile contents of the erupted magmas, leading to the conditions required for the fragmentation of basaltic-andesite. Lava effusion ensues from reduced interactions with the recharge magma, after it has partially degassed and crystallized, thereby impeding rapid ascent. This process could be operating at other steady-state basaltic volcanoes, wherein shallow reservoirs are periodically refilled by fresh, volatile-rich magma

Smoking as a cofactor for causation of chronic pancreatitis: a meta-analysis.

OBJECTIVES: To assess the evidence for tobacco smoking as a risk factor for the causation of chronic pancreatitis. METHODS: We performed a meta-analysis with random-effects models to estimate pooled relative risks (RRs) of chronic pancreatitis for current, former, and ever smokers, in comparison to never smokers. We also performed dose-response, heterogeneity, publication bias, and sensitivity analyses. RESULTS: Ten case-control studies and 2 cohort studies that evaluated, overall, 1705 patients with chronic pancreatitis satisfied the inclusion criteria. When contrasted to never smokers, the pooled risk estimates for current smokers was 2.8 (95% confidence interval [CI], 1.8-4.2) overall and 2.5 (95% CI, 1.3-4.6) when data were adjusted for alcohol consumption. A dose-response effect of tobacco use on the risk was ascertained: the RR for subjects smoking less than 1 pack per day was 2.4 (95% CI, 0.9-6.6) and increased to 3.3 (95% CI, 1.4-7.9) in those smoking 1 or more packs per day. The risk diminished significantly after smoking cessation, as the RR estimate for former smokers dropped to a value of 1.4 (95% CI, 1.1-1.9). CONCLUSIONS: Tobacco smoking may enhance the risk of developing chronic pancreatitis. Recommendation for smoking cessation, besides alcohol abstinence, should be incorporated in the management of patients with chronic pancreatitis

Cancer Risk in Waterpipe Smokers: a Meta-analysis

OBJECTIVES: To quantify by meta-analysis the relationship between waterpipe smoking and cancer, including cancer of the head and neck, esophagus, stomach, lung and bladder. METHODS: We performed a systematic literature search to identify relevant studies, scored their quality, used fixed and random-effect models to estimate summary relative risks (SRR), evaluated heterogeneity and publication bias. RESULTS: We retrieved information from 28 published reports. Considering only highquality studies, waterpipe smoking was associated with increased risk of head and neck cancer (SRR 2.97; 95 % CI 2.26-3.90), esophageal cancer (1.84; 1.42-2.38) and lung cancer (2.22; 1.24-3.97), with no evidence of heterogeneity or publication bias. Increased risk was also observed for stomach and bladder cancer but based mainly on poor-quality studies. For colorectum, liver and for all sites combined risk estimates were elevated, but there were insufficient reports to perform a meta-analysis. CONCLUSIONS: Contrary to the perception of the relative safety of waterpipe smoking, this meta-analysis provides quantitative estimates of its association with cancers of the head and neck, esophagus and lung. The scarcity and limited quality of available reports point out the need for larger carefully designed studies in well-defined populations

H(3)tren (3+) and H(4)tren (4+) fluoride zirconates or tantalates

Four new [H(3)tren](3+) or [H(4)tren](4+) fluoride zirconates and two new [H(3)tren](3+) fluoride tantalates are evidenced in the (ZrF4 or Ta2O5)-tren-HFaq.-ethanol systems at 190 degrees C: the structurally related phases [H(4)tren]center dot(Zr2F12)center dot H2O and alpha-[H(4)tren](center dot)(Zr2F12) (P2(1)2(1)2(1)). beta-[H(4)tren]center dot(Zr2F12) (P2(1/c)), [H(3)tren](4)center dot(ZrF8)(3)center dot 4H(2)O (123). beta-[H(3)tren](2)center dot(Ta3O2F16)center dot(F) (R32) and its monoclinic distortion alpha-[H(3)rren](2)center dot(Ta3O2F16)center dot(F) (C2/m). alpha and beta-[H(4)tren]center dot(Zr2F12) and [H(4)tren]center dot(Zr2F12)center dot H2O are built up from (Zr2F12) dimers of edge sharing ZrF7 polyhedra while isolated ZrF8 dodecahedra are found in [H(3)tren](4)center dot(ZrF8)(3)center dot 4H(2)O. Linear (Ta3O2F16) trimers build et and beta-[H(3)tren](2)center dot(Ta3O2F16)center dot(F); they consist of two (TaOF6) pentagonal bipyramids that are linked to two opposite oxygen atoms of one central (TaO2F4) octahedron. A disorder affects the equatorial fluorine atoms of the trimers and eventually carbon or nitrogen atoms of [H(3)tren](3+) cations. (C) 2011 Elsevier B.V. All rights reserved

Effect of tamoxifen and transdermal hormone replacement therapy on cardiovascular risk factors in a prevention trial. Italian Chemoprevention Group.

The combination of tamoxifen and transdermal hormone replacement therapy (HRT) may potentially reduce risks and side-effects of either agent, but an adverse interaction could attenuate their beneficial effects. We assessed the effects of their combination on cardiovascular risk factors within a prevention trial of tamoxifen. Baseline and 12-month measurements of total, low-density lipoprotein (LDL)- and high-density lipoprotein (HDL)-cholesterol, platelets and white blood cells were obtained in the following four groups: tamoxifen (n = 1117), placebo (n = 1112), tamoxifen and HRT (n = 68), placebo and HRT (n = 87). The analysis was further extended to women who were on HRT at randomization but discontinued it during the 12-month intervention period (n = 33 on tamoxifen and n = 35 on placebo) and to women who were not on HRT but started it during intervention (n = 36 in both arms of the study). Compared with small changes in the placebo group, tamoxifen was associated with changes in total, LDL- and HDL-cholesterol of approximately -9%, -19% and +0.2% in continuous HRT users compared with -9%, -14% and -0.8% in never HRT users. Similarly, there was no interaction on platelet count. In contrast, the decrease in total and LDL-cholesterol levels induced by tamoxifen was blunted by two-thirds in women who started HRT while on tamoxifen (P = 0.051 for the interaction term). We conclude that the beneficial effects of tamoxifen on cardiovascular risk factors are unchanged in current HRT users, whereas they may be attenuated in women who start transdermal HRT while on tamoxifen. Whereas a trial of tamoxifen in women already on transdermal HRT is warranted, prescription of HRT during tamoxifen may attenuate its activity

2,4,6-Triamino-1,3,5-triazine-1,3-diium aqua­penta­fluoridoaluminate

The title compound, (C3H8N6)[AlF5(H2O)], was obtained by solvothermal synthesis from the reaction of aluminium hydroxide, 1,3,5-triazine-2,4,6-triamine (melamine), aqueous HF and water at 323 K for 48 h. The structure consists of [AlF5(H2O)]2− octa­hedra and diprotonated melaminium cations. Cohesion is ensured by a three-dimensional network of hydrogen bonds

Determinants of polyp Size in patients undergoing screening colonoscopy

<p>Abstract</p> <p>Background</p> <p>Pre-existing polyps, especially large polyps, are known to be the major source for colorectal cancer, but there is limited available information about factors that are associated with polyp size and polyp growth. We aim to determine factors associated with polyp size in different age groups.</p> <p>Methods</p> <p>Colonoscopy data were prospectively collected from 67 adult gastrointestinal practice sites in the United States between 2002 and 2007 using a computer-generated endoscopic report form. Data were transmitted to and stored in a central data repository, where all asymptomatic white (n = 78352) and black (n = 4289) patients who had a polyp finding on screening colonoscopy were identified. Univariate and multivariate analysis of age, gender, performance site, race, polyp location, number of polyps, and family history as risk factors associated with the size of the largest polyp detected at colonoscopy.</p> <p>Results</p> <p>In both genders, size of the largest polyp increased progressively with age in all age groups (<it>P </it>< .0001). In subjects ≥ 80 years the relative risk was 1.55 (95% CI, 1.35-1.79) compared to subjects in the youngest age group. With the exception of family history, all study variables were significantly associated with polyp size (<it>P </it>< .0001), with multiple polyps (≥ 2 versus 1) having the strongest risk: 3.41 (95% CI, 3.29-3.54).</p> <p>Conclusions</p> <p>In both genders there is a significant increase in polyp size detected during screening colonoscopy with increasing age. Important additional risk factors associated with increasing polyp size are gender, race, polyp location, and number of polyps, with polyp multiplicity being the strongest risk factor. Previous family history of bowel cancer was not a risk factor.</p

A modified vimentin histological score helps recognize pulmonary sarcomatoid carcinoma in small biopsy samples

Background: As pulmonary sarcomatoid carcinomas (PSCs) are life-threatening tumors, an improvement in their recognition in small-sized tumor samples is clinically warranted. Materials and Methods: Preoperative biopsy samples and paired surgical specimens from 20 pleomorphic carcinomas, two pulmonary blastomas and one carcinosarcoma (training set) were studied for vimentin immunohistochemistry. A modified vimentin histologic score (M-VHS) was devised by multiplying three independently assessed parameters, i.e. the percentage of positive cells (from 0 to 5+, by quintiles), the intensity of immunostaining (low=1 vs. strong=2) and the distribution pattern within the cytoplasm (partial=1 vs. diffuse=2), so ranging from 0 to 20. Forty-eight consecutive and independent cases of non-small cell lung carcinoma (NSCLC), including two additional cases of PSC, were used as control groups (validation set). Results: No differences in M-VHS were found between biopsies and surgical specimens of PSC, thus confirming the occurrence of stable epithelial mesenchymal transition (EMT) and hence the specific diagnosis of PSC. All types of PSC shared the same M-VHS. The M-VHS of 46 conventional NSCLC was by far lower (p&lt;0.0001), whereas two additional cases of PSC showed the same results as the training set. Poorly differentiated NSCLC with marked pleomorphism but not stable EMT did not exhibit significantly increased M-VHS values. Conclusion: M-VHS helped in morphological analysis to render more definite diagnoses on small biopsies of PSC

Survival of patients with HCV cirrhosis and sustained virologic response is similar to the general population.

Background &amp; Aims: Life expectancy of patients with compensated hepatitis C virus (HCV) cirrhosis achieving sustained virologic response (SVR) is limited by liver events as compared to the general population. Thus, survival benefit of SVR remains to be measured. Methods: The study includes prospective surveillance data from three cohorts of Italian patients with compensated HCV cirrhosis who achieved SVR on an interferon-based (IFN) regimen, compared to simultaneously observed non-SVR, untreated and decompensated patients. Overall survival was calculated from the date of start of IFN to death. The number of deaths expected during the at-risk period was determined by applying age- and sex-specific mortality rates recorded in Italy for person-years adequate for the enrolment period. The standardized mortality ratio (SMR) determined the relative risk of death over that of the age and sex matched general population. Results: Overall, 28/181 patients followed-up for a median period of 9.6 years (range 1–25 years) died. The 10 and 20-year overall survival rates for the whole series were 90.9% (95% CI, 84.3–94.8) and 62.9% (95% CI, 45.9–75.9), respectively. The number of expected deaths in the corresponding age and sex matched general population was 28.1, corresponding to a SMR = 1.00 (95% CI, 0.72–1.35), with an SMR for non-SVR patients of 3.85 (95% CI, 3.43–4.30), for untreated of 3.01 (95% CI, 2.64–3.42) and for decompensated of 6.70 (95% CI, 5.39–8.22). Conclusions: Patients with compensated HCV cirrhosis achieving SVR by IFN obtain a main benefit levelling their survival curve to that of the general population. Wider applicability of IFN-free regimens will possibly make this achievement more generalizable