1,974 research outputs found
Management of germ cell tumors in children: Approaches to cure
The introduction of cisplatinum chemotherapy and current advances in the surgical treatment have resulted in a dramatic improvement of the prognosis of children with malignant germ cell tumors (GCT). Cisplatinum chemotherapy generally results in sufficient systemic tumor control, but local relapses may still occur in patients who did not receive adequate local treatment. Therefore, the therapeutic consideration must take into account age, primary site of the tumor, and its histology. In gonadal tumors, there is a high chance of primary complete resection since these tumors tend to be encapsulated, and particularly testicular GCT are often detected at a low tumor stage. In contrast, a primary complete resection may be impossible in large nongonadal tumors such as sacrococcygeal or mediastinal GCT. In these tumors, a neoadjuvant or pre-operative chemotherapy after clinical diagnosis by imaging and evaluation of tumor markers significantly facilitates complete resection on delayed surgery. In addition, the impact of chemotherapy on local tumor control may be enhanced by locoregional hyperthermia. In most intracranial GCT complete resection is impossible and may be associated with significant morbidity. Nevertheless, biopsy is essential for diagnosis in nonsecreting tumors. In intracranial GCT, radiotherapy significantly contributes to local tumor control, and doses are stratified according to histology. These general considerations have been integrated into national and international cooperative treatment protocols. In most current protocols, treatment is stratified according to an initial risk assessment that includes the parameters age, site, histology, stage, completeness of resection and the tumor markers alpha(1)-fetoprotein (AFP) and human choriogonadotropin (beta-HCG). With such modern protocols overall cure rates above 80% can be achieved. Moreover, the previously high-risk groups may now expect a favorable prognosis with this risk-adapted treatment, whereas an increasing number of low-risk patients are treated expectantly or with significantly reduced chemotherapy. As current biologic studies reveal distinct genetic patterns in childhood GCT, it can be expected that further combined clinical and genetic studies will be valuable for risk assessment of childhood GCT
Thermal ageing phenomena and strategies towards reactivation of NO x - storage catalysts
The thermal ageing and reactivation of Ba/CeO2 and Ba/Al2O3 based NO x -storage/ reduction (NSR) catalysts was studied on model catalysts and catalyst systems at the engine. The mixed oxides BaAl2O4 and BaCeO3, which lower the storage activity, are formed during ageing above 850°C and 900°C, respectively. Interestingly, the decomposition of BaCeO3 in an atmosphere containing H2O/NO2 leads again to NO x -storage active species, as evidenced by comparison of fresh, aged and reactivated Pt-Ba/CeO2 based model catalysts. This can be technically exploited, particularly for the Ba/CeO2 catalysts, as reactivation studies on thermally aged Ba/CeO2 and Ba/Al2O3 based NSR catalysts on an engine bench showed. An on-board reactivation procedure is presented, that improved the performance of a thermally aged catalyst significantl
Stop thinking: an experience sampling study on suppressing distractive thoughts at work
This is the final version. Available on open access from Frontiers Media via the DOI in this record. In modern work environments, it can be difficult for workers to avoid becoming
distracted from their current task. This study investigates person–situation interactions
to predict thought control activities (kind of self-control), which aim to stop distracting
thoughts that enter the mind. Specifically, it was examined (1) how challenging work
demands (time pressure, task complexity) activate workers’ thought control to stop
distractive thoughts (nlevel2 = 143) and relate to the effort to do so (nlevel2 = 91) in
daily working life and (2) how these relationships differ according workers’ general
cognitive ability to suppress unwanted thoughts. To understand these person–situation
interactions, an experience sampling study was combined with a laboratory task
assessing the ability to suppress unwanted thoughts (think/no-think task). Multilevel
modeling revealed that workers’ engage more often and more intensively in thought
control activities at a moderate level of time pressure but only when they had a
higher general ability to suppress unwanted thoughts. For workers with a lower ability
to suppress unwanted thoughts, increasing time pressure was negatively related to
thought control activities, even at very low levels of time pressure. Thus, whether time
pressure activates or hinders thought control depends on individuals’ ability to suppress
distractive thoughts.German Research Council (Deutsche Forschungsgemeinschaft, DFG
Анализ современных технологий заводнения при разработке нефтяных месторождений
Объектом исследования являются системы заводнения применяемые на месторождениях России
Цель работы – анализ современных технологий заводнения при разработке нефтяных месторождений, а также обоснование применения технологий заводнения с целью увеличения темпов отбора, коэффициента нефтеизвлечения, технико-экономических показателей.
В выпускной квалификационной работе приведены сведения о современных технологиях заводнения, применяемых на месторождениях России. Проведены расчеты экономической эффективности при внедрении нестационарного метода заводнения. Проанализирован процесс работы методов заводнения в условиях месторождений России. Бакалаврская работа выполнена в текстовом редакторе Microsoft Word, и Microsoft Excel.The object of the study are the waterflooding systems used in the fields of Russia
The aim of the work is the analysis of modern flooding technologies in the development of oil fields, as well as the rationale for using flooding technologies to increase the rate of selection, the oil recovery factor, and the technical and economic indicators. In the final qualification work information on modern water flooding technologies used in the fields of Russia is given. Calculations of economic efficiency are implemented in the introduction of the non-stationary flooding method. The process of work of flooding methods in the conditions of Russian deposits is analyzed. Bachelor's work is executed in the text editor Microsoft Word, and Microsoft Excel
Silica material variation for the Mn<sub>x</sub>O<sub>y</sub>-Na<sub>2</sub>WO<sub>4</sub>/SiO<sub>2</sub>
The oxidative coupling of methane (OCM) is one of the best methods for the direct conversion of methane.Among the known OCM catalysts, MnxOy-Na2WO4/SiO2 is a promising candidate for an industrial appli-cation, showing a high methane conversion and C2 selectivity, with a good stability during long-termcatalytic activity tests. In the present study, some results have been already published and discussedbriefly in our previous short communication. However, we herein investigated comprehensively theinfluence of various silica support materials on the performance of the MnxOy-Na2WO4/SiO2 systemin the OCM by means of ex situ and in situ XRD, BET, SEM and TEM characterization methods andshowed new results to reveal possible support effects on the catalyst. The catalytic performance of most MnxOy-Na2WO4/SiO2 catalysts supported by different silica support materials did not differ substan-tially. However, the performance of the SBA-15 supported catalyst was outstanding and the methaneconversion was nearly twofold higher in comparison to the other silica supported catalysts at similar C2 selectivity as shown before in the communication. The reason of this substantial increase in performancecould be the ordered mesoporous structure of the SBA-15 support material, homogeneous dispersion ofactive components and high number of active sites responsible for the OCM
Оптимизация процесса технического контроля
Объектом настоящего исследования является процесс технического контроля ПАО "ЗиО-Подольск".
Предметом исследования являются теоретические и практические вопросы оптимизации технического контроля для улучшения производственной деятельности организации.
Цель работы – оптимизация процесса технического контроля.
В процессе работы проанализирован и структурирован материал по теме технического контроля. Исследован процесс "Оптимизация процесса оформления и учета актов о браке" предприятия, а также был предложен способ оптимизации данного процесса.
Результатом работы является предложение по оптимизации процесса "Оформление и учет актов о браке".The object of this study is the process of technical control of ZiO-Podolsk PJSC.
The subject of the study is the theoretical and practical issues of optimizing technical control to improve the production activities of the organization.
The purpose of the work is to optimize the process of technical control.
In the process, the material on the topic of technical control is analyzed and structured. The process "Optimization of the process of registration and registration of acts of marriage" of the enterprise was investigated, and a method for optimizing this process was also proposed.
The result of the work is a proposal to optimize the process “Registration and registration of marriage certificates”
Approaching the Gamow Window with Stored Ions : Direct Measurement of Xe 124 (p,γ) in the ESR Storage Ring
© 2019 American Physical Society. All rights reserved.We report the first measurement of low-energy proton-capture cross sections of Xe124 in a heavy-ion storage ring. Xe12454+ ions of five different beam energies between 5.5 and 8 AMeV were stored to collide with a windowless hydrogen target. The Cs125 reaction products were directly detected. The interaction energies are located on the high energy tail of the Gamow window for hot, explosive scenarios such as supernovae and x-ray binaries. The results serve as an important test of predicted astrophysical reaction rates in this mass range. Good agreement in the prediction of the astrophysically important proton width at low energy is found, with only a 30% difference between measurement and theory. Larger deviations are found above the neutron emission threshold, where also neutron and γ widths significantly impact the cross sections. The newly established experimental method is a very powerful tool to investigate nuclear reactions on rare ion beams at low center-of-mass energies.Peer reviewedFinal Published versio
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