Structural changes in activated wood-based carbons: correlation between specific surface area and localization of molecular-sized pores

Samples of maple were pyrolyzed and subsequently activated by carbon dioxide at different temperatures for various dwell times. The changes in wood structure were characterized by nitrogen adsorption isotherms, transmission electron microscopy (TEM) with selected-area electron diffraction (SAED), and scanning electron microscopy (SEM). Increasing pyrolysis temperatures promoted increased crystallization of graphitic wood components and mineral-like phases. The average pore diameter derived from nitrogen adsorption isotherms approximately correlated with the results obtained by high-resolution SEM and TEM. The highest surface area was found for samples containing considerable amounts of nanoperforated pit membranes located in intervascular pitting. High-resolution TEM examinations of membrane regions showed foam-like clusters with an average size of 1.7nm, which are attributed to the selective influence of CO2 activation on pyrolyzed cellulose and ligni

B-site substituted lanthanum strontium ferrites as electrode materials for electrochemical applications

For electrochemical systems such as solid oxide fuel cells (SOFCs) or solid oxide electrolyzer cells (SOECs), perovskites are widely used as cathode material for the reduction of molecular oxygen. At present, strontium-substituted lanthanum manganite, La1-xSrxMnO3-δ (LSM), is used as standard SOFC cathode material for operation at high temperatures, whereas strontium-substituted lanthanum ferrite (LSF) is alternatively explored for medium-temperature SOFCs. Moreover, LSF is considered to be a potential candidate for oxygen separation membranes as the material reported interesting electrical properties. The design of new perovskite-type La transition-metal oxides is of significant technological importance in order to reduce the operating temperature to 600-800 °C and thus to reduce the SOFC system cost. For investigations on a new material class, (La1-xSrx)yFe1-z(Ni,Cu)zO3-δ was synthesized by a spray-pyrolysis process and modified on the A-site in both stoichiometric and non-stoichiometric configurations and on the B-site by substituting Fe with Ni and C

C-myc, not HER-2/neu, can predict recurrence and mortality of patients with node-negative breast cancer

BACKGROUND: At present, node-negative, high-risk breast cancer patients cannot be identified with sufficient accuracy. Consequently, further strong prognostic factors are needed. METHODS: Among 181 node-negative breast cancer (NNBC) patients, c-myc and HER-2/neu oncogenes were identified prospectively using double differential PCR. The possible impact of amplification of those oncogenes on disease-free survival (DFS) and overall survival was examined. Furthermore, the possible effects of adjuvant therapies on rate of recurrence and mortality in oncogene-amplified NNBC patients were investigated. RESULTS: The prevalence rates for amplification of c-myc and HER-2/neu were 21.5% and 30.4%, respectively. On univariate analysis, c-myc-amplified NNBCs were associated with significantly shorter DFS at 36 months after the initial diagnosis (85.3% versus 97.3%). As compared with nonamplified cancers, HER-2/neu-amplified NNBCs did not exhibit any significant differences after 36 months and 95 months. Multivariate analysis indicated that c-myc amplification and tumour size, in contrast to HER-2/neu amplification, oestrogen receptor status, grading and age, were the only independent parameters for DFS. During the period of observation, we found no evidence for an impact of amplification of the oncogenes on overall survival in all cases. With respect to various adjuvant systemic therapies such as chemotherapy (cyclophosphamide, methotrexate, 5-fluorouracil; fluorouracil, epirubicin, cyclophosphamide) and endocrine therapy (tamoxifen), no significant differences were identified in oncogene-amplified NNBC patients in terms of DFS and overall survival. However, those c-myc-amplified NNBC patients who did not receive adjuvant systemic therapy exhibited significantly shorter DFS and overall survival as compared with c-myc-nonamplified patients. CONCLUSION: C-myc amplification appears to be a strong prognostic marker with which to predict early recurrence in NNBC patients. C-myc-amplified NNBC patients without adjuvant systemic therapy experienced shorter DFS and overall survival

Ceramic foam substrates for automotive catalyst applications: fluid mechanic analysis

Several properties of ceramic foams render them promising substrates for various industrial processes. For automotive applications, the foam properties that need to be further studied include the substrate impact on the exhaust gas flow, in terms of pressure drop and flow uniformity. In this paper, pressure drop measurements are performed with different honeycomb and ceramic foam substrates, and pressure drop correlations are discussed. The flow uniformity upstream and downstream of the substrates is evaluated using particle image velocimetry. The results show that ceramic foam substrates induce higher pressure drop, while increasing the uniformity of the flow. In contrast to honeycomb monoliths, the flow uniformity downstream of ceramic foams does not decrease with increasing flow velocity. The higher flow uniformity of ceramic foams is not only caused by their higher pressure drop, but also by flow homogenization that occurs inside the ceramic foam structure, as a result of the momentum exchange perpendicular to the main flow directio

Prophylactic titanium elastic nailing (TEN) following femoral lengthening (Lengthening then rodding) with one or two nails reduces the risk for secondary interventions after regenerate fractures: a cohort study in monolateral vs. bilateral lengthening procedures

Background: Femoral fracture rates of up to 30% have been reported following lengthening procedures using fixators. “Lengthening then rodding” uses one or two titanium elastic nails (TENs) for prophylactic intramedullary nailing to reduce this complication. The aim of the study was to decide if usage of only one TEN is safe or has it a higher risk of getting a fracture? And we asked if there is a difference between patients with monolateral or bilateral lengthening procedures according to their fracture rate? Methods: One or two TENs were implanted in two groups of patients (monolateral and bilateral) after femoral lengthening procedures. The regenerate quality was classified using the Li system and fractures were categorized using the Simpson and Kenwright classification. The follow-up period was at least 1 year after removal of the frame. Results: Sixty-seven patients with 101 femoral lengthening procedures were included in 2007–2011. Group A included 34 patients with bilateral lengthening due to congenital short stature. Group B consisted of 33 patients with congenital disorders with leg length discrepancies. Seven fractures in six patients were seen in group A and five fractures in group B. One patient had residual shortening of 1 cm, and 11 fractures healed without relevant deviation (< 5°) or shortening (< 5 mm). A soft-tissue infection in one patient led to early removal of one TEN. Conclusions: Fractures occurred in both groups of patients in total in 12 of the 101 cases (12%). The rate of secondary interventions was markedly reduced. Usage of one or two TENs did not influence the fracture rate.<br

Digitalisierung im Mittelstand - Ergebnisbericht einer Online-Umfrage

Die Zielsetzung dieser Kurzstudie besteht darin, ein aktuelles Meinungsbild vom Verständnis und Einsatz der Digitalisierung im Sinne von Informations- und Kommunikationstechniken innerhalb mittelständischer Unternehmen zu gewinnen. Die Befragung richtete sich deshalb an Unternehmer, beziehungsweise falls vorhanden auch an Controller, mittelständischer Unternehmen