1,390 research outputs found

    A rapid deployment instrument network for temporarily monitoring volcanic SO2 emissions - a study case from Telica volcano

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    Volcanic gas emissions play a crucial role in describing geophysical processes; hence measurements of magmatic gases such as SO2 can be used as tracers prior and during volcanic crises. Different measurement techniques based on optical spectroscopy have provided valuable information when assessing volcanic crises. This paper describes the design and implementation of a network of spectroscopic instruments based on Differential Optical Absorption Spectroscopy (DOAS) for remote sensing of volcanic SO2 emissions, which is robust, portable and can be deployed in relative short time. The setup allows the processing of raw data in situ even in remote areas with limited accessibility, and delivers pre-processed data to end-users in near real time even during periods of volcanic crisis, via a satellite link. In addition, the hardware can be used to conduct short term studies of volcanic plumes in remotes areas. The network was tested at Telica, an active volcano located in western Nicaragua, producing what is so far the largest data set of continuous SO2 flux measurements at this volcano

    Prospective, open, multi-centre phase I/II trial to assess safety and efficacy of neoadjuvant radiochemotherapy with docetaxel and oxaliplatin in patients with adenocarcinoma of the oesophagogastric junction

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    Background: This phase I/II-trial assessed the dose-limiting toxicities (DLT) and maximum tolerated dose (MTD) of neoadjuvant radiochemotherapy (RCT) with docetaxel and oxaliplatin in patients with locally advanced adenocarcinoma of the oesophagogastric junction. Methods: Patients received neoadjuvant radiotherapy (50.4 Gy) together with weekly docetaxel (20 mg/m2 at dose level (DL) 1 and 2, 25 mg/m2 at DL 3) and oxaliplatin (40 mg/m2 at DL 1, 50 mg/m2 at DL 2 and 3) over 5 weeks. The primary endpoint was the DLT and the MTD of the RCT regimen. Secondary endpoints included overall response rate (ORR) and progression-free survival (PFS). Results: A total of 24 patients were included. Four patients were treated at DL 1, 13 patients at DL 2 and 7 patients at DL 3. The MTD of the RCT was considered DL 2 with docetaxel 20 mg/m2 and oxaliplatin 50 mg/m2. Objective response (CR/PR) was observed in 32% (7/22) of patients. Eighteen patients (75%) underwent surgery after RCT. The median PFS for all patients (n = 24) was 6.5 months. The median overall survival for all patients (n = 24) was 16.3 months. Patients treated at DL 2 had a median overall survival of 29.5 months. Conclusion: Neoadjuvant RCT with docetaxel 20 mg/m2 and oxaliplatin 50 mg/m2 was effective and showed a good toxicity profile. Future studies should consider the addition of targeted therapies to current neoadjuvant therapy regimens to further improve the outcome of patients with advanced cancer of the oesophagogastric junction. Trial Registration: NCT0037498

    High emission rate of sulfuric acid from Bezymianny volcano, Kamchatka

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    High concentrations of primary sulfuric acid (H2SO4) in fumarolic gases and high emission rate of sulfuric acid aerosol in the plume were measured at Bezymianny volcano, an active dome-growing andesitic volcano in central Kamchatka. Using direct sampling, filter pack sampling, and differential optical absorption spectroscopy measurements, we estimated an average emission of H2SO4 at 243 ± 75 t/d in addition to an average SO2 emission of 212 ± 65 t/d. The fumarolic gases of Bezymianny correspond to arc gases released by several magma bodies at different stages of degassing and contain 25-92% of entrained air. H2SO4 accounts for 6-87 mol% of the total sulfur content, 42.8 mol% on average, and SO2 is the rest. The high H2SO4 in Bezymianny fumaroles can be explained by catalytic oxidation of SO2 inside the volcanic dome. Because sulfate aerosol is impossible to measure remotely, the total sulfur content in a plume containing significant H2SO4 may be seriously underestimated

    Epigenetic Drifts during Long-Term Intestinal Organoid Culture

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    Organoids retain the morphological and molecular patterns of their tissue of origin, are self-organizing, relatively simple to handle and accessible to genetic engineering. Thus, they represent an optimal tool for studying the mechanisms of tissue maintenance and aging. Long-term expansion under standard growth conditions, however, is accompanied by changes in the growth pattern and kinetics. As a potential explanation of these alterations, epigenetic drifts in organoid culture have been suggested. Here, we studied histone tri-methylation at lysine 4 (H3K4me3) and 27 (H3K27me3) and transcriptome profiles of intestinal organoids derived from mismatch repair (MMR)-deficient and control mice and cultured for 3 and 20 weeks and compared them with data on their tissue of origin. We found that, besides the expected changes in short-term culture, the organoids showed profound changes in their epigenomes also during the long-term culture. The most prominent were epigenetic gene activation by H3K4me3 recruitment to previously unmodified genes and by H3K27me3 loss from originally bivalent genes. We showed that a long-term culture is linked to broad transcriptional changes that indicate an ongoing maturation and metabolic adaptation process. This process was disturbed in MMR-deficient mice, resulting in endoplasmic reticulum (ER) stress and Wnt activation. Our results can be explained in terms of a mathematical model assuming that epigenetic changes during a long-term culture involve DNA demethylation that ceases if the metabolic adaptation is disturbed

    Microarray-Based Gene Expression Analysis of Hepatocellular Carcinoma

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    Microarray studies have successfully shed light on various aspects of the molecular mechanisms behind the development of hepatocellular carcinoma (HCC), such as the identification of novel molecular subgroups and the genetic profiles associated with metastasis and venous invasion. These experiments, mainly comprising genome wide profiling, potentially represent the basis of novel targeted therapeutic strategies in HCC. In response, we summarize the multiple reported expression profiles in HCC associated with HCC development, novel subgroups, venous invasion and metastasis

    X-Ray photoelectron spectroscopy and mass spectrometry studies of X-ray-processed solid CO2

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    Solid CO2 films have been grown on a stainless steel substrate and processed by X-ray bombardment for up to 6 hr.. The reactions induced were monitored using X-ray photoelectron spectroscopy (XPS) and mass spectrometry. The XPS results are twofold: direct X-ray photolysis of the CO2 ice produced CO and an unidentified O product, possibly atomic O; secondary effects resulting from surface reactions between CO, O, and residual H from the vacuum environment produced H2CO, CH3OH, and a water ice cap on the CO2 film. The rate of production of CO from direct X-ray photolysis of CO2 is measured to be 5.4 Ă— 102 molecule photon-1, corresponding to a formation cross section of 4.7 Ă— 10-20 cm2. The growth rate for the water cap is calculated to be 2.6 Ă— 10-4 monolayers s-1 for a partial pressure of H equal to 2 Ă— 10-10 Torr. The appearance of gas-phase products from the film showed a time lag which indicates that the diffusion of the product species in the bulk CO2 is affected by some time-dependent process, possibly the creation of defects in the film. A model for the observed time dependence of the dissociation products in the gas phase yields diffusion coefficients in the CO2 of 5 Ă— 10-12 and 1 Ă— 10-12 cm2 s-1, for O and CO, respectively

    Mediterranean diet, physical activity and gut microbiome composition: A cross-sectional study among healthy young italian adults

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    Background. This cross-sectional study aimed to explore the microbial composition of the gut and its possible association with the Mediterranean diet (MD) after adjusting for demographic and anthropometric characteristics in a sample of healthy young Italian adults. Methods. Gut microbiota, demographic information, and data on adherence to MD and physical activity (PA) habits were collected in a sample of 140 university students (48.6% males, mean age 22.5 ± 2.9) with a mean body mass index (BMI) of 22.4 ± 2.8 kg/m2 (15.2–33.8) and a mean PA level of 3006.2 ± 2973.6 metabolic equivalent (MET)-minutes/week (148–21,090). Results. A high prevalence of Firmicutes and Bacteroidetes was found in all the fecal samples. Significant dissimilarities in the microbiota composition were found on the basis of MD adherence and PA levels (p = 0.001). At the genus level, Streptococcus and Dorea were highly abundant in overweight/obese individuals, Ruminococcus and Oscillospira in participants with lower adherence to MD, and Lachnobacterium in subjects with low levels of PA (p = 0.001). A significantly higher abundance of Paraprevotella was shown by individuals with lower BMI, lower MD adherence, and lower PA levels (p = 0.001). Conclusions. This study contributes to the characterization of the gut microbiome of healthy humans. The findings suggest the role of diet and PA in determining gut microbiota variability

    Gemcitabine in combination with EGF-Receptor antibody (Cetuximab) as a treatment of cholangiocarcinoma: a case report

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    BACKGROUND: Extensive disease of cholangiocarcinoma (CC) determines the overall outcome and limits curative resection. Despite chemotherapy, which has been introduced to improve the outcome of biliary tract malignancies, the benefit in survival is still marginal. CASE PRESENTATION: We report a 69-year-old patient with non-resectable CC showing hepatic metastasis and peritoneal carcinomatosis. Diagnosis was based on computed tomography, mini-laparoscopy and bioptic specimens. Histology revealed an adenocarcinoma of the biliary tract with expression of epithelial growth factor receptor. After informed consent the patient received experimental gemcitabine (1000 mg/m(2)) every other week and cetuximab (250 mg/m(2)) weekly for palliative chemotherapy. During the reported follow up (since time of first presentation) 20 cycles of chemotherapy were administered. Relevant chemotherapy-related toxicity was limited on gemcitabine-associated side effects. Predominantly, haematological toxicity (CTC, grade 3) and neutropenic fever (CTC, grade 3) promoted by catheter-related sepsis were observed. Cetuximab caused only mild skin toxicity (CTC, grade 1). Chemotherapy led to a partial response (> 30% reduction, according to RECIST) of the target lesions and disappearance of the peritoneal carcinomatosis as shown by computed tomography. Partial response occurred after 17 weeks of treatment and remained stable during the entire course of chemotherapy for 9.7 months. In parallel, Ca 19-9 serum levels, which were elevated 5-fold at time of diagnosis, returned to normal after 16 weeks of treatment. The performance status stabilized and intravenous alimentation could be discontinued. CONCLUSION: Our experience from one patient with CC suggests, that a combination of cytotoxic chemotherapy together with cetuximab may show promising efficacy in respect to survival and quality of life. Therefore cetuximab, as a component of palliative chemotherapy in biliary tract cancer, needs further evaluation in prospective randomized trials

    Ion Microscopy: A New Approach for Subcellular Localization of Labelled Molecules

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    Secondary ion mass spectroscopy (SIMS) was used to obtain images representing the intracellular distribution of molecules labelled with carbon 14. Deoxyadenosine labelled with carbon 14 was added to a cultured human fibroblast cell medium, and the intracellular distribution of this molecule was studied using three different SIMS instruments: the CAMECA IMS 3F and SMI 300 ion microscopes and the UC-HRL scanning ion microprobe. Carbon 14 distribution images obtained by this method show that deoxyadenosine U-C14 is present in the cytoplasm as well as the nucleus, with a higher concentration in\u27 the nucleoli. Our study clearly demonstrates that ion microscopy is well suited for carbon 14 detection and localization at the subcellular level, permitting a wide variety of microanalytical tracer experiments
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