A modular cable robot for inspection and light manipulation on celestial bodies

Planetary exploration has been carried out with solitary probes since the nineteen-sixties; on the other hand, the newly emerging paradigm for robotic exploration shows multi-expertize, complex modular systems as necessary for efficient and thorough activities. In this paper we propose a modular Cable Driven Parallel Robot (CDPR) that is deployed by a rover, which can take advantage of its large workspace for tasks as inspection or light manipulation. While the general deployment procedure is described, focus is given on the CDPR; a model for the pseudostatics of the robot is formulated, as well as an analysis on its modules stability. The workspace is then characterized using appropriate metrics. Results show that a 1 Kg payload for the end-effector is effectively feasible with substantial margin for an equilateral triangular workspace of 10 m side. Finally, several possible practical applications are illustrated

Extending holographic LEED to ordered small unit cell superstructures

Following on the success of the recent application of holographic LEED to the determination of the 3D atomic geometry of Si adatoms on a SiC(111) p(3x3) surface, which enabled that structure to be solved, we show in this paper that a similar technique allows the direct recovery of the local geometry of adsorbates forming superstructures as small as p(2x2), even in the presence of a local substrate reconstruction.Comment: 10 pages, 5 figures postscript included, revtex, Phys. Rev. B in pres

Retrospective analysis and clinical evaluation of mandible reconstruction with free fibula flap

The objective of this investigation was to evaluate the indications for and the functional and cosmetic results of mandible reconstruction using free vascularized fibular flaps. It was also designed to assess the patients' quality of life, daily activities, and self-esteem, with special emphasis on patient satisfaction. We conducted a retrospective chart review of all patients who underwent osseus or osteocutaneous free flap reconstruction of the mandible over a 10-year period (1992-2002). Those in whom a vascularized fibular flap was used were included in the study and invited for a follow-up comprehensive physical examination and x-ray evaluation. A questionnaire was also administered to evaluate patient satisfaction. Twenty-six patients were included in the study. Fourteen patients died after an average of 2years and 9months postoperatively due to their prognosis despite surgical intervention and adjuvant therapy. Of the remaining 12 patients, 6 appeared for the follow-up evaluation, 2 were unavailable for follow-up, and 4 denied participating. Of these 6 patients, all experienced a decrease in pain and were satisfied with their results. At the time of the latest follow-up, they experienced some difficulties swallowing, and in 3 patients, their articulation was impaired. All 6 patients would undergo the procedure again. Reconstruction of the mandible using a vascularized fibular graft produces satisfactory functional and cosmetic results. In benign lesions, the procedure is highly indicated. However, in the case of malignancy, most patients do not survive their primary tumor. Given the patients limited life expectancy, the improvement in their quality of life as a result of the improved appearance and function of the reconstructed mandible needs to be weighed against the potential morbidity of the operative intervention on an individual basi

Should human chondrocytes fly? The impact of electromagnetic irradiation on chondrocyte viability and implications for their use in tissue engineering

A significant logistic factor as to the successful clinical application of the autologous tissue engineering concept is efficient transportation: the donor cells need to be delivered to tissue processing facilities which in most cases requires air transportation. This study was designed to evaluate how human chondrocytes react to X-ray exposure. Primary cell cultures were established, cultured, incubated and exposed to different doses and time periods of radiation. Subsequently, quantitative cell proliferation assays were done and qualitative evaluation of cellular protein production were performed. Our results show that after irradiation of chondrocytes with different doses, no significant differences in terms of cellular viability occurred compared with the control group. These results were obtained when chondrocytes were exposed to luggage transillumination doses as well as exposure to clinically used radiation doses. Any damage affecting cell growth or quality was not observed in our study. However, information about damage of cellular DNA remains incomplet

Early fluid resuscitation with hyperoncotic hydroxyethyl starch 200/0.5 (10%) in severe burn injury

INTRODUCTION: Despite large experience in the management of severe burn injury, there are still controversies regarding the best type of fluid resuscitation, especially during the first 24 hours after the trauma. Therefore, our study addressed the question whether hyperoncotic hydroxyethyl starch (HES) 200/0.5 (10%) administered in combination with crystalloids within the first 24 hours after injury is as effective as 'crystalloids only' in severe burn injury patients. METHODS: 30 consecutive patients were enrolled to this prospective interventional open label study and assigned either to a traditional 'crystalloids only' or to a 'HES 200/0.5 (10%)' volume resuscitation protocol. Total amount of fluid administration, complications such as pulmonary failure, abdominal compartment syndrome, sepsis, renal failure and overall mortality were assessed. Cox proportional hazard regression analysis was performed for binary outcomes and adjustment for potential confounders was done in the multivariate regression models. For continuous outcome parameters multiple linear regression analysis was used. RESULTS: Group differences between patients receiving crystalloids only or HES 200/0.5 (10%) were not statistically significant. However, a large effect towards increased overall mortality (adjusted hazard ratio 7.12; P = 0.16) in the HES 200/0.5 (10%) group as compared to the crystalloids only group (43.8% versus 14.3%) was present. Similarly, the incidence of renal failure was 25.0% in the HES 200/0.5 (10%) group versus 7.1% in the crystalloid only group (adjusted hazard ratio 6.16; P = 0.42). CONCLUSIONS: This small study indicates that the application of hyperoncotic HES 200/0.5 (10%) within the first 24 hours after severe burn injury may be associated with fatal outcome and should therefore be used with caution

The oncofetal RNA-binding protein IGF2BP1 is a druggable, post-transcriptional super-enhancer of E2F-driven gene expression in cancer

The IGF2 mRNA-binding protein 1 (IGF2BP1) is a non-catalytic post-transcriptional enhancer of tumor growth upregulated and associated with adverse prognosis in solid cancers. However, conserved effector pathway(s) and the feasibility of targeting IGF2BP1 in cancer remained elusive. We reveal that IGF2BP1 is a post-transcriptional enhancer of the E2F-driven hallmark in solid cancers. IGF2BP1 promotes G1/S cell cycle transition by stabilizing mRNAs encoding positive regulators of this checkpoint like E2F1. This IGF2BP1-driven shortening of the G1 cell cycle phase relies on 3′UTR-, miRNA- and m6A-dependent regulation and suggests enhancement of cell cycle progression by m6A-modifications across cancers. In addition to E2F transcription factors, IGF2BP1 also stabilizes E2F-driven transcripts directly indicating post-transcriptional 'super'-enhancer role of the protein in E2F-driven gene expression in cancer. The small molecule BTYNB disrupts this enhancer function by impairing IGF2BP1-RNA association. Consistently, BTYNB interferes with E2F-driven gene expression and tumor growth in experimental mouse tumor models

First Principles Calculations of Fe on GaAs (100)

We have calculated from first principles the electronic structure of 0.5 monolayer upto 5 monolayer thick Fe layers on top of a GaAs (100) surface. We find the Fe magnetic moment to be determined by the Fe-As distance. As segregates to the top of the Fe film, whereas Ga most likely is found within the Fe film. Moreover, we find an asymmetric in-plane contraction of our unit-cell along with an expansion perpendicular to the surface. We predict the number of Fe 3d-holes to increase with increasing Fe thickness on $p$-doped GaAs.Comment: 9 pages, 14 figures, submitted to PR