Composite Metal-hydrogen Electrodes for Metal-Hydrogen Batteries

The purpose of this project is to develop and conduct a feasibility study of metallic thin films (multilayered and alloy composition) produced by advanced sputtering techniques for use as anodes in Ni-metal hydrogen batteries. The anodes could be incorporated in thin film solid state Ni-metal hydrogen batteries that would be deposited as distinct anode, electrolyte and cathode layers in thin film devices. The materials could also be incorporated in secondary consumer batteries (i.e. type AF(4/3 or 4/5)) which use electrodes in the form of tapes. The project was based on pioneering studies of hydrogen uptake by ultra-thin Pd-capped metal-hydrogen ratios exceeding and fast hydrogen charging and Nb films, these studies suggested that materials with those of commercially available metal hydride materials discharging kinetics could be produced. The project initially concentrated on gas phase and electrochemical studies of Pd-capped niobium films in laboratory-scale NiMH cells. This extended the pioneering work to the wet electrochemical environment of NiMH batteries and exploited advanced synchrotron radiation techniques not available during the earlier work to conduct in-situ studies of such materials during hydrogen charging and discharging. Although batteries with fast charging kinetics and hydrogen-metal ratios approaching unity could be fabricated, it was found that oxidation, cracking and corrosion in aqueous solutions made pure Nb films-and multiiayers poor candidates for battery application. The project emphasis shifted to alloy films based on known elemental materials used for NiMH batteries. Although commercial NiMH anode materials contain many metals, it was found that 0.24 µm thick sputtered Zr-Ni films cycled at least 50 times with charging efficiencies exceeding 95% and [H]/[M] ratios of 0.7-1.0. Multilayered or thicker Zr-Ni films could be candidates for a thin film NiMH battery that may have practical applications as an integrated power source for modern electronic devices

Histological Consequences of Needle-Nerve Contact following Nerve Stimulation in a Pig Model

Background. Nerve stimulation can facilitate correct needle placement in peripheral regional anesthesia. The aim of this study was to determine whether the high threshold current is associated with reduced nerve injury due to fewer needle-nerve contacts compared with low current. Methods. In anaesthetized pigs, thirty-two nerves of the brachial plexus underwent needle placement at low (0.2 mA) or high current (1.0 mA). The occurrence of needle-nerve contact was recorded. After 48 hours, the nerves were analyzed for occurrence of histological changes. Nerve injury was scored ranging from 0 (no injury) to 4 (severe injury). Results. The frequency of needle-nerve contact was 94% at low compared to 6% at high current. The score was significantly higher at low (median [interquartile range] 2.0 [1.0-2.0]) compared to high current (0.0 [0.0-1.0] P = .001). Conclusions. Inflammatory responses were directly related to needle-nerve contacts. Hence, posttraumatic inflammation may be diminished using higher current for nerve localization

Influence of different treatment conditions on the filtration performance of conventional electret melt blown non-woven and novel nano FFP2 masks

To allow an efficient protection against viruses like the severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2), it is important to avoid their spreading by using filtering face pieces (FFP), which are categorized by different standards according to their filtration efficiency. In this study, we subjected six brands of FFP2 standard masks to three different conditions and subsequently analysed them for their filtration performance to evaluate potentials for reusability. The conditions comprised changes of temperature and air humidity, an exposure to isopropyl alcohol (IPA) and an autoclave sterilization. While four of six masks consisted of electrostatically treated melt blown non-wovens, two masks were fabricated using a nanofibrous multilayer system. Due to the absence of prior electrostatic treatment, the nano-masks did not show a significant change in filtration efficiency when discharged by IPA, unlike the melt blown nonwoven masks showing a significant decrease of filtration efficiency down to around 50% at a particle size of 0.3 μm. However, most melt blown masks maintained a sufficient filtration efficiency after all other treatments with even better results than the nanofibrous masks. This was particularly the case for the capacity to filter smallest particles/droplets with a size of around 0.1 μm, which is below the range of typical filtering standards and important for the retention of virally contaminated nano-aerosols or unattached viruses. After temperature/humidity variation and autoclave sterilization, melt blown masks were able to retain a filtration efficiency up to over 90% at 0.1 μm contrary to nano-masks showing a decrease down to around 70%. Based on their better filtration performance, lower price and potential reusability, we conclude that electret melt blown masks are the preferable type of FFP2 masks.</jats:p

Extracts of Rheum palmatum and Aloe vera show beneficial properties for the synergistic improvement of oral wound healing

Various local and systemic factors compromise oral wound healing and may lead to wound dehiscence, inflammation, or ulcers. Currently, there is a lack of topical therapeutical options. Thus, this study aimed to investigate the effect of Aloe vera (AV) and Rheum palmatum root (RPR) on oral wound healing capacity in vitro. The effect of AV and RPR on human primary fibroblast viability and migration was studied by measuring metabolic activity and gap closure in a scratch assay. Furthermore, cell cycle distribution and cytoskeletal features were analyzed. Antimicrobial activity against the oral pathogen Porphyromonas gingivalis was evaluated by broth microdilution assay. AV and RPR increased fibroblast migration after single agent treatment. Synergistic effects of the plant extract combination were observed regarding cellular migration which were confirmed by calculation of the phenomenological combination index (pCI), whereas the cell cycle distribution was not influenced. Furthermore, the combination of AV and RPR showed synergistic antibacterial effects as determined by the fractional inhibitory concentration index. This study demonstrated that the combination of AV and RPR can promote the migration of human primary fibroblasts in vitro and exert antimicrobial efficacy against P. gingivalis, suggesting these compounds for the topical treatment of wound healing disorders

Consistency in scalable systems

[EN] While eventual consistency is the general consistency guarantee ensured in cloud environments, stronger guarantees are in fact achievable. We show how scalable and highly available systems can provide processor, causal, sequential and session consistency during normal functioning. Failures and network partitions negatively affect consistency and generate divergence. After the failure or the partition, reconciliation techniques allow the system to restore consistency.This work has been supported by EU FEDER and Spanish MICINN under research grants TIN2009-14460-C03-01 and TIN2010-17193.Ruiz Fuertes, MI.; Pallardó Lozoya, MR.; Muñoz-Escoí, FD. (2012). Consistency in scalable systems. En On the Move to Meaningful Internet Systems: OTM 2012. Springer Verlag (Germany). 7566:549-565. https://doi.org/10.1007/978-3-642-33615-7_7S5495657566Ahamad, M., Bazzi, R.A., John, R., Kohli, P., Neiger, G.: The power of processor consistency. In: Proceedings of the Fifth Annual ACM Symposium on Parallel Algorithms and Architectures, SPAA 1993, pp. 251–260. ACM, New York (1993), http://doi.acm.org/10.1145/165231.165264Alvarez, A., Arévalo, S., Cholvi, V., Fernández, A., Jiménez, E.: On the Interconnection of Message Passing Systems. Inf. Process. Lett. 105(6), 249–254 (2008)Amazon Web Services LLC: Amazon Simple Storage Service (S3). Website (March 2011), http://aws.amazon.com/s3/Baker, J., Bond, C., Corbett, J.C., Furman, J.J., Khorlin, A., Larson, J., Léon, J., Li, Y., Lloyd, A., Yushprakh, V.: Megastore: Providing Scalable, Highly Available Storage for interactive services. In: 5th Biennial Conf. on Innovative Data Systems Research (CIDR), Asilomar, CA, USA, pp. 223–234 (January 2011)Baldoni, R., Beraldi, R., Friedman, R., van Renesse, R.: The Hierarchical Daisy Architecture for Causal Delivery. Distributed Systems Engineering 6(2), 71–81 (1999)Bernstein, P.A., Hadzilacos, V., Goodman, N.: Concurrency Control and Recovery in Database Systems. Addison-Wesley (1987)Bernstein, P.A., Reid, C.W., Das, S.: Hyder - A Transactional Record Manager for Shared Flash. In: 5th Biennial Conf. on Innovative Data Systems Research (CIDR), Asilomar, CA, USA, pp. 9–20 (January 2011)Bershad, B.N., Zekauskas, M.J., Sawdon, W.A.: The Midway Distributed Shared Memory System. In: Proc. IEEE CompCon Conf. (1993)Brewer, E.A.: Towards Robust Distributed Systems (Abstract). In: Proc. ACM Symp. Princ. Distrib. Comput., p. 7 (2000)Budhiraja, N., Marzullo, K., Schneider, F.B., Toueg, S.: The Primary-Backup Approach. In: Mullender, S.J. (ed.) Distributed Systems, 2nd edn., ch. 8, pp. 199–216. Addison-Wesley, ACM Press (1993)Campbell, D.G., Kakivaya, G., Ellis, N.: Extreme Scale with Full SQL Language Support in Microsoft SQL Azure. In: Intnl. Conf. on Mngmnt. of Data (SIGMOD), pp. 1021–1024. ACM, New York (2010), http://doi.acm.org/10.1145/1807167.1807280Cholvi, V., Jiménez, E., Anta, A.F.: Interconnection of distributed memory models. J. Parallel Distrib. Comput. 69(3), 295–306 (2009)Cooper, B.F., Ramakrishnan, R., Srivastava, U., Silberstein, A., Bohannon, P., Jacobsen, H., Puz, N., Weaver, D., Yerneni, R.: PNUTS: Yahoo!’s hosted data serving platform. PVLDB 1(2), 1277–1288 (2008)Daudjee, K., Salem, K.: Lazy Database Replication with Ordering Guarantees. In: Proc. Int. Conf. Data Eng., pp. 424–435. IEEE-CS (2004)Daudjee, K., Salem, K.: Lazy Database Replication with Snapshot Isolation. In: Proc. Int. Conf. Very Large Data Bases, pp. 715–726. ACM (2006)DeCandia, G., Hastorun, D., Jampani, M., Kakulapati, G., Lakshman, A., Pilchin, A., Sivasubramanian, S., Vosshall, P., Vogels, W.: Dynamo: Amazon’s Highly Available Key-value Store. In: ACM Symp. Oper. Syst. Princ., pp. 205–220 (2007)Fernández, A., Jiménez, E., Cholvi, V.: On the interconnection of causal memory systems. J. Parallel Distrib. Comput. 64(4), 498–506 (2004)Gilbert, S., Lynch, N.A.: Brewer’s Conjecture and the Feasibility of Consistent, Available, Partition-Tolerant Web Services. ACM SIGACT News 33(2), 51–59 (2002)Goodman, J.R.: Cache Consistency and Sequential Consistency. Tech. Rep. 61, SCI Committee (March 1989)Gray, J., Helland, P., O’Neil, P.E., Shasha, D.: The Dangers of Replication and a Solution. In: Proc. ACM SIGMOD Int. Conf. Manage. Data, pp. 173–182. ACM (1996)Helland, P., Campbell, D.: Building on Quicksand. In: Proc. Bienn. Conf. Innov. Data Syst. Research (2009), www.crdrdb.orgHutto, P., Ahamad, M.: Slow Memory: Weakening Consistency to Enhance Concurrency in Distributed Shared Memories. In: Proceedings of the 10th International Conference on Distributed Computing Systems, pp. 302–311 (May 1990)Johnson, S., Jahanian, F., Shah, J.: The Inter-group Router Approach to Scalable Group Composition. In: ICDCS, pp. 4–14 (1999)Kraska, T., Hentschel, M., Alonso, G., Kossmann, D.: Consistency Rationing in the Cloud: Pay only when it matters. PVLDB 2(1), 253–264 (2009)Lamport, L.: How to Make a Multiprocessor Computer that Correctly Executes multiprocess programs. IEEE Trans. Computers 28(9), 690–691 (1979)Lipton, R.J., Sandberg, J.S.: Pram: A Scalable Shared Memory. Tech. Rep. CS-TR-180-88, Princeton University, Department of Computer Science (September 1988)Mosberger, D.: Memory Consistency Models. Operating Systems Review 27(1), 18–26 (1993)Ruiz-Fuertes, M.I., Muñoz-Escoí, F.D.: Refinement of the One-Copy Serializable Correctness Criterion. Tech. Rep. ITI-SIDI-2011/004, Instituto Tecnológico de Informática, Valencia, Spain (November 2011)Stonebraker, M., Madden, S., Abadi, D.J., Harizopoulos, S., Hachem, N., Helland, P.: The End of an Architectural Era (It’s Time for a Complete Rewrite). In: 33rd Intnl. Conf. on Very Large Data Bases (VLDB), pp. 1150–1160. ACM Press, Vienna (2007)Terry, D.B., Demers, A.J., Petersen, K., Spreitzer, M., Theimer, M., Welch, B.B.: Session Guarantees for Weakly Consistent Replicated Data. In: Proc. Int. Conf. Parallel Distrib. Inform. Syst., pp. 140–149. IEEE-CS (1994)Vogels, W.: Eventually Consistent. Communications of the ACM (CACM) 52(1), 40–44 (2009)VoltDB, Inc.: VoltDB technical overview: A high performance, scalable RDBMS for Big Data, high velocity OLTP and realtime analytics. Website (April 2012), http://voltdb.com/sites/default/files/PDFs/VoltDBTechnicalOverview_April_2012.pdfWiesmann, M., Schiper, A.: Comparison of Database Replication Techniques Based on Total Order Broadcast. IEEE T. Knowl. Data En. 17(4), 551–566 (2005

Lepton beam polarization at LEP

Results from studies on transverse polarization in LEP over the past two years are presented. A single beam transverse polarization level of 57% at 45 GeV was reached adopting strategies to compensate depolarizing effcts originating in the four experimental solenoids and from orbit pertubations. Beam Energy Calibration was performed by Resonant Depolarization during the 1993 LEP Run for Physics at three different energies centered around the Z peak. The uncertainty on the beam energy was reduced to about 1 MeV, thus improving the accuracy on the Z-resonance mass and width with respect to previous results. Successful results obtained at the end of the 1994 LEP Run on polarization with colliding beams are reported and future plans outlined

Electrical resistivity at large temperatures: Saturation and lack thereof

Many transition metal compounds show saturation of the resistivity at high temperatures, T, while the alkali-doped fullerenes and the high-Tc cuprates are usually considered to show no saturation. We present a model of transition metal compounds, showing saturation, and a model of alkali-doped fullerenes, showing no saturation. To analyze the results we use the f-sum rule, which leads to an approximate upper limit for the resistivity at large T. For some systems and at low T, the resistivity increases so rapidly that this upper limit is approached for experimental T. The resistivity then saturates. For a model of transition metal compounds with weakly interacting electrons, the upper limit corresponds to a mean free path consistent with the Ioffe-Regel condition. For a model of the high Tc cuprates with strongly interacting electrons, however, the upper limit is much larger than the Ioffe-Regel condition suggests. Since this limit is not exceeded by experimental data, the data are consistent with saturation also for the cuprates. After "saturation" the resistivity usually grows slowly. For the alkali-doped fullerenes, "saturation" can be considered to have happened already for T=0, due to orientational disorder. For these systems, however, the resistivity grows so rapidly after "saturation" that this concept is meaningless. This is due to the small band width and to the coupling to the level energies of the important phonons.Comment: 22 pages, RevTeX, 19 eps figures, additional material available at http://www.mpi-stuttgart.mpg.de/andersen/fullerene

Optimal Cerebral Perfusion Pressure During Delayed Cerebral Ischemia After Aneurysmal Subarachnoid Hemorrhage

OBJECTIVES: The recommendation of induced hypertension for delayed cerebral ischemia treatment after aneurysmal subarachnoid hemorrhage has been challenged recently and ideal pressure targets are missing. A new concept advocates an individual cerebral perfusion pressure where cerebral autoregulation functions best to ensure optimal global perfusion. We characterized optimal cerebral perfusion pressure at time of delayed cerebral ischemia and tested the conformity of induced hypertension with this target value. DESIGN: Retrospective analysis of prospectively collected data. SETTING: University hospital neurocritical care unit. PATIENTS: Thirty-nine aneurysmal subarachnoid hemorrhage patients with invasive neuromonitoring (20 with delayed cerebral ischemia, 19 without delayed cerebral ischemia). INTERVENTIONS: Induced hypertension greater than 180 mm Hg systolic blood pressure. MEASUREMENTS AND MAIN RESULTS: Changepoint analysis was used to calculate significant changes in cerebral perfusion pressure, optimal cerebral perfusion pressure, and the difference of cerebral perfusion pressure and optimal cerebral perfusion pressure 48 hours before delayed cerebral ischemia diagnosis. Optimal cerebral perfusion pressure increased 30 hours before the onset of delayed cerebral ischemia from 82.8 +/- 12.5 to 86.3 +/- 11.4 mm Hg (p < 0.05). Three hours before delayed cerebral ischemia, a changepoint was also found in the difference of cerebral perfusion pressure and optimal cerebral perfusion pressure (decrease from -0.2 +/- 11.2 to -7.7 +/- 7.6 mm Hg; p < 0.05) with a corresponding increase in pressure reactivity index (0.09 +/- 0.33 to 0.19 +/- 0.37; p < 0.05). Cerebral perfusion pressure at time of delayed cerebral ischemia was lower than in patients without delayed cerebral ischemia in a comparable time frame (cerebral perfusion pressure delayed cerebral ischemia 81.4 +/- 8.3 mm Hg, no delayed cerebral ischemia 90.4 +/- 10.5 mm Hg; p < 0.05). Inducing hypertension resulted in a cerebral perfusion pressure above optimal cerebral perfusion pressure (+12.4 +/- 8.3 mm Hg; p < 0.0001). Treatment response (improvement of delayed cerebral ischemia: induced hypertension(+) [n = 15] or progression of delayed cerebral ischemia: induced hypertension(-) [n = 5]) did not correlate to either absolute values of cerebral perfusion pressure or optimal cerebral perfusion pressure, nor the resulting difference (cerebral perfusion pressure [p = 0.69]; optimal cerebral perfusion pressure [p = 0.97]; and the difference of cerebral perfusion pressure and optimal cerebral perfusion pressure [p = 0.51]). CONCLUSIONS: At the time of delayed cerebral ischemia occurrence, there is a significant discrepancy between cerebral perfusion pressure and optimal cerebral perfusion pressure with worsening of autoregulation, implying inadequate but identifiable individual perfusion. Standardized induction of hypertension resulted in cerebral perfusion pressures that exceeded individual optimal cerebral perfusion pressure in delayed cerebral ischemia patients. The potential benefit of individual blood pressure management guided by autoregulation-based optimal cerebral perfusion pressure should be explored in future intervention studies