Formalism for Multiphoton Plasmon Excitation in Jellium Clusters

We present a new formalism for the description of multiphoton plasmon excitation processes in jellium clusters. By using our method, we demonstrate that, in addition to dipole plasmon excitations, the multipole plasmons (quadrupole, octupole, etc) can be excited in a cluster by multiphoton absorption processes, which results in a significant difference between plasmon resonance profiles in the cross sections for multiphoton as compared to single-photon absorption. We calculate the cross sections for multiphoton absorption and analyse the balance between the surface and volume plasmon contributions to multipole plasmons.Comment: 29 pages, 1 figur

Comparison of two protective lung ventilatory regimes on oxygenation during one-lung ventilation: a randomized controlled trial

<p>Abstract</p> <p>Background</p> <p>The efficacy of protective ventilation in acute lung injury has validated its use in the operating room for patients undergoing thoracic surgery with one-lung ventilation (OLV). The purpose of this study was to investigate the effects of two different modes of ventilation using low tidal volumes: pressure controlled ventilation (PCV) vs. volume controlled ventilation (VCV) on oxygenation and airway pressures during OLV.</p> <p>Methods</p> <p>We studied 41 patients scheduled for thoracoscopy surgery. After initial two-lung ventilation with VCV patients were randomly assigned to one of two groups. In one group OLV was started with VCV (tidal volume 6 mL/kg, PEEP 5) and after 30 minutes ventilation was switched to PCV (inspiratory pressure to provide a tidal volume of 6 mL/kg, PEEP 5) for the same time period. In the second group, ventilation modes were performed in reverse order. Airway pressures and blood gases were obtained at the end of each ventilatory mode.</p> <p>Results</p> <p>PaO₂, PaCO₂and alveolar-arterial oxygen difference did not differ between PCV and VCV. Peak airway pressure was significantly lower in PCV compared with VCV (19.9 ± 3.8 cmH₂O vs 23.1 ± 4.3 cmH₂O; p < 0.001) without any significant differences in mean and plateau pressures.</p> <p>Conclusions</p> <p>In patients with good preoperative pulmonary function undergoing thoracoscopy surgery, the use of a protective lung ventilation strategy with VCV or PCV does not affect the oxygenation. PCV was associated with lower peak airway pressures.</p

Enhancement of endogenous neurogenesis in ephrin-B3 deficient mice after transient focal cerebral ischemia

Cerebral ischemia stimulates endogenous neurogenesis. However, the functional relevance of this phenomenon remains unclear because of poor survival and low neuronal differentiation rates of newborn cells. Therefore, further studies on mechanisms regulating neurogenesis under ischemic conditions are required, among which ephrin-ligands and ephrin-receptors (Eph) are an interesting target. Although Eph/ephrin proteins like ephrin-B3 are known to negatively regulate neurogenesis under physiological conditions, their role in cerebral ischemia is largely unknown. We therefore studied neurogenesis, brain injury and functional outcome in ephrin-B3−/− (knockout) and ephrin-B3+/+ (wild-type) mice submitted to cerebral ischemia. Induction of stroke resulted in enhanced cell proliferation and neuronal differentiation around the lesion site of ephrin-B3−/− compared to ephrin-B3+/+ mice. However, prominent post-ischemic neurogenesis in ephrin-B3−/− mice was accompanied by significantly increased ischemic injury and motor coordination deficits that persisted up to 4 weeks. Ischemic injury in ephrin-B3−/− mice was associated with a caspase-3-dependent activation of the signal transducer and activator of transcription 1 (STAT1). Whereas inhibition of caspase-3 had no effect on brain injury in ephrin-B3+/+ animals, infarct size in ephrin-B3−/− mice was strongly reduced, suggesting that aggravated brain injury in these animals might involve a caspase-3-dependent activation of STAT1. In conclusion, post-ischemic neurogenesis in ephrin-B3−/− mice is strongly enhanced, but fails to contribute to functional recovery because of caspase-3-mediated aggravation of ischemic injury in these animals. Our results suggest that ephrin-B3 might be an interesting target for overcoming some of the limitations of further cell-based therapies in stroke

A fast modular multiplication method

IEEE;K.U.A.S.;Technische Universitat Darmstadt6th International Conference on Intelligent Information Hiding and Multimedia Signal Processing, IIHMSP 2010 --15 October 2010 through 17 October 2010 -- Darmstadt --Fast execution of modular multiplication is crucial to speed-up public key cryptography applications. This paper presents a modular multiplication method that exploits high-speed multiply-accumulate instructions supported in modern general-purpose architectures. The algorithm is implemented as a C program and tested on large operands by using GNU Multiple Precision Library (GMP). The performance of the method is compared with the performance of the Montgomery's Algorithm. The comparision results show that the proposed method runs upto 5 times faster than Montgomery's Algorithm. © 2010 IEEE

Radiographic evaluation of low-level laser therapy-enhanced maxillary sinus augmentation with simultaneous dental implant placement

Background: To evaluate the effect of low-level laser therapy (LLLT) on bone healing in patients undergoing bilateral sinus lifting and simultaneous dental implant application. Methods: Twelve patients with total/partial posterior maxillary edentulism who needed bilateral sinus bone augmentation were included in the study. Dental implants were inserted in the same session. LLLT (? = 630-660 nm, 25 mW/cm2, 6 min) was used for one operation side on the 1st, 3rd, 5th, and 7th days, whereas contralateral side served as control side. Preoperative and postoperative 1st, 3rd, and 6th month orthopantomograms were obtained using the aluminum step-wedge technique. Optic density analyses were performed using a Cardinal Health Digital Densitometer (Fluke Biomedical 07-443) with 1 mm diameter. Digital densitometry results were obtained as the equivalent aluminum thickness for each radiograph. These data were used to evaluate the changes in optical bone density and to compare the treatment side with the control side for each patient. Results: The LLLT side showed better results than the control side according to the densitometry results. Increase in the bone density at all the postoperative intervals was statistically significant (P &lt; 0.05). Conclusions: LLLT enhances bone regeneration in sinus augmentation with simultaneous dental implant placement. © 2019 Wolters Kluwer Medknow Publications. All rights reserved