Chemoresistance of glioblastoma cancer stem cells - much more complex than expected

Glioblastomas (GBM) are a paradigm for the investigation of cancer stem cells (CSC) in solid malignancies. The susceptibility of GBM CSC to standard chemotherapeutic drugs is controversial as the existing literature presents conflicting experimental data. Here, we summarize the experimental evidence on the resistance of GBM CSC to alkylating chemotherapeutic agents, with a special focus on temozolomide (TMZ). The data suggests that CSC are neither resistant nor susceptible to chemotherapy per se. Detoxifying proteins such as O6-methylguanine-DNA-methyltransferase (MGMT) confer a strong intrinsic resistance to CSC in all studies. Extrinsic factors may also contribute to the resistance of CSC to TMZ. These may include TMZ concentrations in the brain parenchyma, TMZ dosing schemes, hypoxic microenvironments, niche factors, and the re-acquisition of stem cell properties by non-stem cells. Thus, the interaction of CSC and chemotherapy is more complex than may be expected and it is necessary to consider these factors in order to overcome chemoresistance in the patient

Обґрунтування вибору обладнання сонячної електростанції потужністю 20 МВт з 3D візуалізацією об’єкту

Моделювання об’єктів енергетики у 3D та компонування розподільчого пункту та комплектних трансформаторних підстанцій Спроектовано сонячну електростанцію 20 МВт і зроблено 3D візуалізація компонентів станції. Описується де знаходиться сонячна електростанція актуальні проблеми та рішення альтернативних джерел енергії. Застосування зеленого тарифу. Що таке проектування в 3D. Показано компоновку розташування елементів енергетики. Виконані розрахунки електрообладнання. Алгоритм моделювання сонячної панелі. 3D модель кожного елемента

Изменение структуры и свойств покрытия на основе стали Р6М5 при воздействии импульсов лазерного излучения

Объектом исследования является покрытие на основе стали Р6М5, подверженное лазерному излучению. Целью данной работы является исследование влияния параметров режима импульсного лазерного воздействия на структуру и свойства покрытия на основе стали Р6М5. В процессе исследования подвергали лазерному излучению поверхностный слой образца, замеряли уровень твердости поверхностного слоя образца обработанного лазерным излучением.Das Ziel der Forschung basiert Beschichtung Stahl R6M5, Bestrahlung mit Laserstrahlung. Das Ziel dieser Arbeit ist der Einfluß der Parameter der gepulsten Lasermode Auswirkungen auf die Struktur und die Eigenschaften der Beschichtung auf der Basis von Stahl R6M5 zu studieren. Die Studie wurde mit Laserstrahlung mit einer Oberflächenschicht der Probe unterzogen wird, das Niveau der Härte der Oberflächenschicht der Probe mit der Laserstrahlung behandelt gemessen

Editorial : Advances in the spatial and temporal evolution of oceanic arc-backarc systems

Non peer reviewe

Geochemical mapping of a paleo-subduction zone beneath the Troodos Ophiolite

Supra-subduction zone ophiolites such as the Cretaceous Troodos Ophiolite of Cyprus are fragments of oceanic crust formed by seafloor spreading close to subduction zones. Their exact tectonic setting of origin has been intensively debated. Although many supra-subduction zone ophiolites are thought to represent fore-arc crust, created during subduction initiation, others may have formed at a subducting ridge, or in a back-arc, ridge-trench-trench/transform triple junction or ‘plate edge’ setting. We carried out major and trace element analyses of 515 fresh volcanic glasses from 7 detailed sections through the Troodos lava sequence in order to determine the regional and temporal variation in the composition of Troodos magmatism, and hence reconstruct the distance and orientation of the Troodos spreading axis relative to the former subduction zone. Troodos glasses range from boninite through tholeiitic basalt and andesite to dacite. All glasses are enriched in fluid-mobile trace elements, and variably depleted in the high-field strength elements compared to Mid-Ocean Ridge Basalt (MORB). None of these glasses therefore have compositions identical to Izu-Bonin-Mariana fore-arc lavas that have been proposed to be the prime example of lavas formed during subduction initiation. Boninites are apparently restricted to the southern margin of the Troodos Ophiolite, and glasses from the southeast margin of the ophiolite are the most depleted and contain the strongest input of subduction zone fluid and melt signature. These geographic variations in glass composition indicate that the Troodos Ophiolite formed by NW-SE directed spreading (at 91 Ma) approximately 100–120 km above an eastward-dipping subducting plate. The orientation of the Troodos spreading axis relative to the former trench could be explained if the Troodos Ophiolite formed in a fore-arc position by subduction initiation at a transform fault. However, the lack of glasses with fore-arc basalt composition, and similarities between the trace element compositions of Troodos glasses and those from the Fonualei basin and northern Lau Basin in the southwest Pacific suggest that the Troodos Ophiolite formed in a ridge-trench-trench or ridge-trench-transform triple junction setting, at a back-arc spreading centre that propagated into arc and fore-arc crust.Peer reviewe

Constraints on mantle evolution from Ce-Nd-Hf isotope systematics

Mantle evolution is governed by continuous depletion by partial melting and replenishment by recycling oceanic and continental crust. Several important unknowns remain, however, such as the extent of compositional variability of the residual depleted mantle, the timescale, mass flux and composition of recycled oceanic and continental crust. Here, we investigate the Ce-Nd-Hf isotope systematics in a globally representative spectrum of mid ocean ridge and ocean island basalts. Using a Monte Carlo approach for reproducing the observed Ce-Nd-Hf isotope variation shows that the type and age of depleted mantle and recycled crust have the dominant influence on the slope, scatter, and extent of the modeled Ce-Nd-Hf isotope array. The model results suggest a relatively young (Peer reviewe

Short-term effective treatment of CNS metastasis of sarcomatoid renal cell carcinoma with temozolomide and pegylated liposomal doxorubicin: A case report

Sarcomatoid renal cell carcinoma represents high-grade transformation of different subtypes of renal cell carcinoma and is associated with a dismal prognosis and high resistance to chemotherapy. We report on the course of disease of a 63 years old patient undergoing a nearly complete remission of multiple intracranial and spinal metastatic lesions of a sarcomatoid renal cell carcinoma by a combined chemotherapy with temozolomide and pegylated liposomal doxorubicin

In Situ Chalcophile and Siderophile Element Behavior in Sulfides from Moroccan Middle Atlas Spinel Peridotite Xenoliths during Metasomatism and Weathering

In situ chalcophile and siderophile major and trace elements were analyzed in sulfides from eight Moroccan Middle Atlas lherzolite xenoliths using electron microprobe and laser ablation inductively coupled plasma mass spectrometry. The sulfides occur enclosed in primary silicates, interstitial in the peridotite matrix, and associated with glass-bearing melt pockets. Monosulfide solid solutions are enriched in these xenoliths relative to pentlandite and intermediate solid solutions. Regardless of the textural occurrence, sulfide platinum-group element (PGE) patterns are distinguished into residual ([Pd/Ir]N 1 or [Pt/Pd]N 1), and unfractionated patterns. The coexistence of both residual and melt-like PGE signatures on a cm scale in a single sample implies that sulfides may record initial depletion and subsequent re-enrichment more effectively than constituent silicates do. Chalcophile and siderophile trace elements other than the PGEs are fractionated between the precipitated sulfide phases, but do not vary systematically with the PGE signatures, suggesting that the PGEs are comparatively sensitive to melting and depletion. In addition, Fe-rich hydroxides generated by sulfide breakdown due to atmospheric weathering display PGE systematics almost identical to their precursor sulfides, implying that they may be reliable tracers of mantle processes even after extensive weathering

In Situ Chalcophile and Siderophile Element Behavior in Sulfides from Moroccan Middle Atlas Spinel Peridotite Xenoliths during Metasomatism and Weathering

In situ chalcophile and siderophile major and trace elements were analyzed in sulfides from eight Moroccan Middle Atlas lherzolite xenoliths using electron microprobe and laser ablation inductively coupled plasma mass spectrometry. The sulfides occur enclosed in primary silicates, interstitial in the peridotite matrix, and associated with glass-bearing melt pockets. Monosulfide solid solutions are enriched in these xenoliths relative to pentlandite and intermediate solid solutions. Regardless of the textural occurrence, sulfide platinum-group element (PGE) patterns are distinguished into residual ([Pd/Ir]N 1 or [Pt/Pd]N 1), and unfractionated patterns. The coexistence of both residual and melt-like PGE signatures on a cm scale in a single sample implies that sulfides may record initial depletion and subsequent re-enrichment more effectively than constituent silicates do. Chalcophile and siderophile trace elements other than the PGEs are fractionated between the precipitated sulfide phases, but do not vary systematically with the PGE signatures, suggesting that the PGEs are comparatively sensitive to melting and depletion. In addition, Fe-rich hydroxides generated by sulfide breakdown due to atmospheric weathering display PGE systematics almost identical to their precursor sulfides, implying that they may be reliable tracers of mantle processes even after extensive weathering.Peer reviewe