168 research outputs found

    Сравнительный анализ методов измерения газовых сред и организация технического контроля качества нефтепродуктов

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    Газовая промышленность – наиболее молодая отрасль топливного комплекса. Применяется газ в качестве топлива в промышленности и в быту, а качестве сырья для химической промышленности.Gas industry - the youngest branch of the fuel complex. Suitable gas as fuel in industry and in everyday life, as well as raw material for the chemical industry

    Polarization filtering for automatic picking of seismic data and improved converted phase detection

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    Data-adaptive polarization filtering is used to improve the detection of converted seismic phases. Both direct waves and mode-converted PS and SP arrivals may be more easily picked on the filtered records. An autopicking routine is applied that cuts the polarization filtered traces according to the modelled traveltime of each phase through an initial structure. Use of forward-modelled, source–receiver times reduces the likelihood of an automatic pick being incorrectly made on spurious spikes in the polarization filtered trace. It is therefore a realistic way of automatically picking multiphase data sets or, more generally, linearly polarized phases where low signal-to-noise ratios may be encountered. The method is suitable for any three-component seismic data and is here applied to local earthquakes recorded in North Island, New Zealand. Intermediate energy is observed between the direct P and S arrivals due to phase conversion at the interface between the Indo-Australian and subducting Pacific plates. The amplitudes of these converted arrivals are often too low for them to be identified above the P-wave coda but polarization filtering of the records enables the yield of converted phase picks to be greatly increased

    Synthesis of thermochemically stable tetraphenyladamantane-based microporous polymers as gas storage materials

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    In view of environmental pollution control and purification of natural gases, developing ideal porous materials for small gas molecule (hydrogen, methane and carbon dioxide) capture is an important, pressing challenge. Accordingly, herein, three microporous organic polymers (MOP-Ad) have been synthesized by Suzuki coupling polymerization of 1,3,5,7-tetrakis(4-bromophenyl)adamantane “knots” with three phenylboronic acid-type “rods”. Gas adsorption studies of the MOP-Ad materials demonstrated their permanent porosity and good gas storage capabilities (1.07 wt% H2 at 77.3 K and 1.13 bar, 10.3 wt% CO2 and 2.4 wt% CH4 at 273.1 K and 1.13 bar), as well as moderate CO2/CH4 adsorption selectivity. Moreover, high thermal stability (up to 520 °C) and remarkable chemical resistance to strong acids and bases were found in these polymers, making them suitable candidates as gas storage materials in harsh chemical environments

    A phase ib clinical trial of metformin and chloroquine in patients with IDH1-mutated solid tumors

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    Simple SummaryMutations in the isocitrate dehydrogenase 1 (IDH1) gene occur in high-grade chondrosarcoma, high-grade glioma and intrahepatic cholangiocarcinoma. Due to the lack of effective treatment options, these aggressive types of cancer have a dismal outcome. The metabolism of IDH1-mutated cancer cells is reprogrammed in order to produce the oncometabolite D-2-hydroxyglutarate (D-2HG). In this clinical trial, we used the oral antidiabetic drug metformin and the oral antimalarial drug chloroquine to disrupt the vulnerable metabolism of IDH1-mutated solid tumors. We found that the combination regimen of metformin and chloroquine is well tolerated, but the combination did not induce a clinical response in this patient population. Secondly, we confirmed the clinical usefulness of D/L-2HG ratios in serum as a biomarker and the ddPCR-facilitated detection of an IDH1 mutation in circulating DNA from peripheral blood.Background: Mutations in isocitrate dehydrogenase 1 (IDH1) occur in 60% of chondrosarcoma, 80% of WHO grade II-IV glioma and 20% of intrahepatic cholangiocarcinoma. These solid IDH1-mutated tumors produce the oncometabolite D-2-hydroxyglutarate (D-2HG) and are more vulnerable to disruption of their metabolism. Methods: Patients with IDH1-mutated chondrosarcoma, glioma and intrahepatic cholangiocarcinoma received oral combinational treatment with the antidiabetic drug metformin and the antimalarial drug chloroquine. The primary objective was to determine the occurrence of dose-limiting toxicities (DLTs) and the maximum tolerated dose (MTD). Radiological and biochemical tumor responses to metformin and chloroquine were investigated using CT/MRI scans and magnetic resonance spectroscopy (MRS) measurements of D-2HG levels in serum. Results: Seventeen patients received study treatment for a median duration of 43 days (range: 7-74 days). Of twelve evaluable patients, 10 patients discontinued study medication because of progressive disease and two patients due to toxicity. None of the patients experienced a DLT. The MTD was determined to be 1500 mg of metformin two times a day and 200 mg of chloroquine once a day. A serum D/L-2HG ratio of >= 4.5 predicted the presence of an IDH1 mutation with a sensitivity of 90% and a specificity of 100%. By utilization of digital droplet PCR on plasma samples, we were able to detect tumor-specific IDH1 hotspot mutations in circulating tumor DNA (ctDNA) in investigated patients. Conclusion: Treatment of advanced IDH1-mutated solid tumors with metformin and chloroquine was well tolerated but did not induce a clinical response in this phase Ib clinical trial.Molecular tumour pathology - and tumour geneticsMTG

    Liver decompensation as late complication in HCC patients with long-term response following selective internal radiation therapy

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    Simple Summary: Hepatocellular carcinoma (HCC) is one of the deadliest forms of cancer. Selective internal radiation therapy (SIRT) is one of the therapeutic options for treatment of advanced HCC. Studies show that SIRT has a high objective response rate, but lack of survival benefit when compared to different treatment modalities. We hypothesized that this is due to potential damage in healthy liver parenchyma as a side-effect of SIRT, resulting in functional changes to the liver. This can ultimately result in liver decompensation and potentially death. The aim of this retrospective study was to assess long-term liver-related complications after SIRT in patients with HCC. We analyzed patients who underwent SIRT and found that liver decompensation occurred more often after SIRT when compared to sorafenib. However, careful patient selection may result in a survival benefit after SIRT when compared to other treatments. The ABLI score may be a valuable prognostic score for selecting patients.Selective internal radiation therapy (SIRT) is used as a treatment for hepatocellular carcinoma (HCC). The aim of this study was to assess long-term liver-related complications of SIRT in patients who had not developed radioembolization-induced liver disease (REILD). The primary outcome was the percentage of patients without REILD that developed Child-Pugh (CP) & GE; B7 liver decompensation after SIRT. The secondary outcomes were overall survival (OS) and tumor response. These data were compared with a matched cohort of patients treated with sorafenib. Eighty-five patients were included, of whom 16 developed REILD. Of the remaining 69 patients, 38 developed liver decompensation CP & GE; B7. The median OS was 18 months. In patients without REILD, the median OS in patients with CP & GE; B7 was significantly shorter compared to those without CP & GE; B7; 16 vs. 31 months. In the case-matched analysis, the median OS was significantly longer in SIRT-treated patients; 16 vs. 8 months in sorafenib. Liver decompensation CP & GE; B7 occurred significantly more in SIRT when compared to sorafenib; 62% vs. 27%. The ALBI score was an independent predictor of liver decompensation (OR 0.07) and OS (HR 2.83). After SIRT, liver decompensation CP & GE; B7 often developed as a late complication in HCC patients and was associated with a shorter OS. The ALBI score was predictive of CP & GE; B7 liver decompensation and the OS, and this may be a valuable marker for patient selection for SIRT.Imaging- and therapeutic targets in neoplastic and musculoskeletal inflammatory diseas

    Preoperative misdiagnosis of pancreatic and periampullary cancer in patients undergoing pancreatoduodenectomy: a multicentre retrospective cohort study

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    Introduction: Whereas neoadjuvant chemo(radio)therapy is increasingly used in pancreatic cancer, it is currently not recommended for other periampullary (non-pancreatic) cancers. This has important implications for the relevance of the preoperative diagnosis for pancreatoduodenectomy. This retrospective multicentre cohort study aimed to determine the frequency of clinically relevant misdiagnoses in patients undergoing pancreatoduodenectomy for pancreatic or other periampullary cancer. Methods: Data from all consecutive patients who underwent a pancreatoduodenectomy between 2014 and 2018 were obtained from the prospective Dutch Pancreatic Cancer Audit. The preoperative diagnosis as concluded by the multidisciplinary team (MDT) meeting was compared with the final postoperative diagnosis at pathology to determine the rate of clinically relevant misdiagnosis (defined as missed pancreatic cancer or incorrect diagnosis of pancreatic cancer). Results: In total, 1244 patients underwent pancreatoduodenectomy of whom 203 (16%) had a clinically relevant misdiagnosis preoperatively. Of all patients with a final diagnosis of pancreatic cancer, 13% (87/ 679) were preoperatively misdiagnosed as distal cholangiocarcinoma (n = 41, 6.0%), ampullary cancer (n = 27, 4.0%) duodenal cancer (n = 16, 2.4%), or other (n = 3, 0.4%). Of all patients with a final diagnosis of periampullary (non-pancreatic) cancer, 21% (116/565) were preoperatively incorrectly diagnosed as pancreatic cancer. Accuracy of preoperative diagnosis was 84% for pancreatic cancer, 71% for distal cholangiocarcinoma, 73% for ampullary cancer and 73% for duodenal cancer. A prediction model for the preoperative likelihood of pancreatic cancer (versus other periampullary cancer) prior to pancreatoduodenectomy demonstrated an AUC of 0.88. Discussion: This retrospective multicentre cohort study showed that 16% of patients have a clinically relevant misdiagnosis that could result in either missing the opportunity of neoadjuvant chemotherapy in patients with pancreatic cancer or inappropriate administration of neoadjuvant chemotherapy in patients with non-pancreatic periampullary cancer. A preoperative prediction model is available on www.pancreascalculator.com. (c) 2021 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).Surgical oncolog
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