134 research outputs found
Control of the blood–brain barrier function in cancer cell metastasis
No full textCerebral metastases are the most common brain neoplasms seen clinically in the adults and comprise more than half of all brain tumours. Actual treatment options for brain metastases that include surgical resection, radiotherapy and chemotherapy are rarely curative, although palliative treatment improves survival and life quality of patients carrying brain-metastatic tumours. Chemotherapy in particular has also shown limited or no activity in brain metastasis of most tumour types. Many chemotherapeutic agents used systemically do not cross the blood-brain barrier (BBB), whereas others may transiently weaken the BBB and allow extravasation of tumour cells from the circulation into the brain parenchyma. Increasing evidence points out that the interaction between the BBB and tumour cells plays a key role for implantation and growth of brain metastases in the central nervous system. The BBB, as the tightest endothelial barrier, prevents both early detection and treatment by creating a privileged microenvironment. Therefore, as observed in several in vivo studies, precise targetting the BBB by a specific transient opening of the structure making it permeable for therapeutic compounds, might potentially help to overcome this difficult clinical problem. Moreover, a better understanding of the molecular features of the BBB, its interrelation with metastatic tumour cells and the elucidation of cellular mechanisms responsible for establishing cerebral metastasis must be clearly outlined in order to promote treatment modalities that particularly involve chemotherapy. This in turn would substantially expand the survival and quality of life of patients with brain metastasis, and potentially increase the remission rate. Therefore, the focus of this review is to summarise the current knowledge on the role and function of the BBB in cancer metastasis
Robot-assisted replacement of the refractory components of the ladle sliding gate in a steel shop
No full textRobots are wide spread in most industrial sectors and relieve operators from cumbersome, repetitive and sometimes harmful operations. In the steel sector the implementation of human-robot-cooperation is hampered and slowed down by harsh environmental conditions in some applications, as well as by intrinsic difficulties of some operations, which require a combination of force and precision and need to be supervised and acknowledged by the technical personnel due to strict safety regulations. The paper presents an ad-hoc designed robotic workstation, which has been developed and installed in the steel shop of an Italian steel company, representing one of the first attempts to establish a collaborative environment where a robot supports the technical personnel in a complex and delicate maintenance operation. The purpose of the robotic cell is to support the inspection, cleaning and replacement operations of the refractory components of the so-called “sliding gate”, namely the device allowing the liquid steel to flow from the ladle to the tundish of the continuous casting. The robotic cell includes a vision system supporting the different operations, and a Human Machine Interface, which facilitates the interaction between the robot and the operators and helps to improve the qualitative performance of the whole process. Within such a course, the sequence and new division of human-robot activities were thoroughly developed within an innovation process integrating the future users and operators (embedding technological innovation within a social innovation process)
Information Linkages and Correlated Trading
No full textIn a market with informationally connected traders, the dynamics of volume, price informativeness, price volatility, and liquidity are severely affected by the information linkages every trader experiences with his peers. We show that in the presence of information linkages among traders, volume and price informativeness increase. Moreover, we find that information linkages improve or damage market depth, and lower or boost the Traders' profits, according to whether these linkages convey positively or negatively correlated signals. Finally, our model predicts patterns of trade correlation consistent with those identified in the empirical literature: trades generated by "neighbor" traders are positively correlated and trades generated by "distant" traders are negatively correlated. The Author 2009. Published by Oxford University Press on behalf of The Society for Financial Studies. All rights reserved. For Permissions, please e-mail: [email protected]., Oxford University Press.
Stent-retriever assisted vacuum-locked extraction (SAVE) versus a direct aspiration first pass technique (ADAPT) for acute stroke: data from the real-world
No full textAbstract Background Embolectomy is the standard of care in acute ischemic stroke (AIS) caused by large vessel occlusion (LVO). Aim of this study was to compare two techniques: A Direct Aspiration First Pass Technique (ADAPT) and Stent-retriever Assisted Vacuum-locked Extraction (SAVE) stratified by the occluded vessel. Methods One hundred seventy-one patients (71 male) treated between January 2014 and September 2017 with AIS due to LVO of the anterior circulation (55 carotid T, 94 M1, 22 M2) were included. Treatment techniques were divided into two categories: ADAPT and SAVE. Primary endpoints were successful reperfusion (mTICI ≥2b), near-perfect reperfusion (mTICI ≥2c) and groin puncture to reperfusion time. Secondary endpoints were the number of device-passes, first-pass reperfusion, the frequency of emboli to new territory (ENT), clinical outcome at 90 days, and the frequency of symptomatic intracranial hemorrhage (sICH). Analysis was performed on an intention to treat basis. Results Overall, SAVE resulted in significant higher rates of successful reperfusion (mTICI≥2b) compared to ADAPT (93.5% vs 75.0%; p = 0.006). After stratification for the occluded vessel only the carotid T remained significant with higher rates of near-perfect reperfusion (mTICI≥2c) (55.2% vs 15.4%; p = 0.025), while for successful reperfusion a trend remained (93.1% vs 65.4%; p = 0.10). Groin to reperfusion times were not significantly different. Secondary analysis revealed higher rates of first-pass successful reperfusion (59.6% vs 33.3%; p = 0.019), higher rates of first-pass near-perfect reperfusion in the carotid T (35.4% vs 16.7%; p = 0.038) and a lower number of device-passes overall (median 1 IQR 1–2 vs 2 IQR 2–3; p < 0.001) and in the carotid T (median 2 IQR 1.3 vs 3 IQR 2–5; p < 0.001) for SAVE. Clinical outcome and safety parameters were comparable between groups. Conclusions Embolectomy using SAVE appears superior to ADAPT, especially for carotid T occlusions with regard to reperfusion success
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