A new scheme to generate isolated attosecond pulses is presented that involves the use of a laser field and of a unipolar field. The laser field has a pulse of intensity I = 1.5times1014 W cm-2 and ...wavelength λ = 820 nm. The unipolar pulse is an asymmetric pulse consisting of a sharp peak, lasting approximately half a laser period, i.e. nearly 1.4 fs, followed by a long and shallow tail. We show that on combining these two fields, it is possible to generate isolated attosecond pulses as short as 1/10 of a laser period, i.e. approximately 270 as. Moreover, it is argued that this scheme is robust either against small variations of the laser envelope, or against small changes in the delay between the laser pump and the unipolar pulse. PUBLICATION ABSTRACT
This paper investigates the relationship between mapping style and device roadmap in Resistive Random Access Memory (ReRAM) architectures for neuromorphic computing. The study leverages simulations ...using DNN+NeuroSim to evaluate the impact of different parameters on chip performance, including latency, energy consumption, and overall system efficiency. The results demonstrate that novel mapping techniques and a high-performance (HP) device roadmap are optimal if energy and speed considerations are weighted equally. This is because as the study demonstrates, HP devices provide a latency cut that outsizes the energy cost. Additionally, adopting novel mapping in the device cuts latency by nearly 30% while being slightly more energy efficient. The findings highlight the importance of considering mapping style and device roadmap in optimizing ReRAM architectures for neuromorphic computing, which may contribute to advancing the practical implementation of ReRAM in computational systems.
Near nanomolar concentrations of substance P induce production of IL-1 or an IL-1-like activity in the mouse macrophage cell line P388D1. Moreover, this could be accomplished with the ...carboxyl-terminal octapeptide substance P4-11, and could be inhibited with the substance P antagonist D-Pro2, D-Trp7,9-substance P. Two other mammalian neurokinins, neurokinin A and neurokinin B, were also found to induce secretion of IL-1-like activity in P388D1 cells. These findings suggest that activation of immune cells by neuromodulators can contribute to the maintenance of the chronic inflammatory state and the immunopathology observed in arthritic disease mediated by IL-1. The results also suggest that one approach to the treatment of rheumatoid arthritis might be to attempt to inhibit the local effects of immuno-modulatory neuropeptides, specifically the neurokinins, in affected joints.
Surgery is considered the treatment of choice for postoperative biliary strictures. Recently, endoscopic stent placement has been proposed as an alternative to surgical management in selected ...patients.
In this retrospective study, 157 patients with postoperative biliary strictures were included. Eighty patients (group A) were treated endoscopically and 77 by surgery (group B). Baseline characteristics of patients were comparable in both groups. Endoscopic therapy consisted of placement of endoprostheses, with trimonthly elective exchange for a 1-year period. Surgical therapy consisted of constructing a biliary-digestive anastomosis in normal ductal tissue. Data were evaluated according to intention-to treat analysis.
Successful treatment was achieved in 54% of group A and 73% of group B (
P <0.001). Overall 31% of patients developed complications in group A and 23% of patients in group B (
P <0.05). However, the rates of severe complications were comparable in both groups (11% versus 13%;
P = not significant) In group A the mortality rate was 0% compared with 8% of group B (
P <0.05). Recurrent stenosis was evidenced in 6% of patients of group A and 5% of patients of group B.
Surgery provides a better long-term outcome over the endoscopy, because of patients with total obstruction are not amenable to endoscopic approach. When successfully done, endoscopic results are similar to surgical results with less mortality.
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An approximation method, suitable for an analytical treatment of the Kramers-Henneberger potential in three dimensions, is presented. The method is applied to various potentials which are currently ...used in one and three dimensions with reference to the problem of an electron in a strong field. This approach is shown to lead to a better understanding of the approximations previously adopted to deal with Coulomb and with localized potentials. Moreover, in the case of polynomial potentials of the double-well form, the method predicts a striking change in the dynamics of the electron for suitable values of the physical parameters.
A novel series of N-(2-benzothiazolylthio)alkyl-N'-hydroxyurea derivatives (9-25) was synthesized and evaluated for biological activity as inhibitors of 5-lipoxygenase both in vivo (mouse zymosan ...peritonitis assay) and in vitro (Ca2+ ionophore-stimulated human peripheral blood leukocyte model). The compounds of this series were based on the corresponding hydroxamic acid derivatives (1, 3, 4, and 5) which were moderately active in vitro but inactive in vivo. A number of compounds in the hydroxyurea series exhibited oral activity for 5-lipoxygenase inhibition. Results of studies relating structure to in vivo and in vitro 5-lipoxygenase activity are reported.
Leaks from laparoscopic cholecystectomy De Palma, Giovanni D; Galloro, Giuseppe; Iuliano, Gianpaolo ...
Hepato-gastroenterology,
07/2002, Volume:
49, Issue:
46
Journal Article
Peer reviewed
Significant postoperative bile leaks occur in approximately 1% of patients. The goal of endoscopic therapy is to eliminate the transpapillary pressure gradient, thereby permitting preferential ...transpapillary bile flow rather than extravasation at the site of leak.
Sixty-four patients were retrospectively evaluated. Endoscopic treatment comprised endoscopic sphincterotomy followed by insertion of a naso-biliary drainage or a stent. Retained stones were extracted by standard procedures.
The site of bile extravasation was the cystic duct in 50 cases, ducts of Luschka in 4 cases, common bile duct in 6 cases and common hepatic duct in 4 cases. Retained bile duct stones were detected in 21 cases and papillary stenosis in 4 cases. Endoscopic sphincterotomy was performed in 25 cases, with stones extraction and nasobiliary drainage in 21 cases, and placement of stent in the remainder. Bile leaks resolved in 96.9% of patients, after endoscopic procedure. Two cases of mild pancreatitis were evidenced from endoscopic treatment.
Endoscopic management is the treatment of choice of postcholecystectomy bile leaks.
The glycine amide of tolmetin sodium (TGA) functions as a prodrug and was demonstrated to be more potent than the parent compound as an inhibitor of developing and established adjuvant arthritis in ...the female Lewis rat. In contrast, the glycine amide of indomethacin was less potent than indomethacin. The superiority of TGA relative to tolmetin sodium in alleviating this condition was demonstrated by inhibition of paw swelling and reduction of the degenerative bone changes that are associated with the progression of this chronic animal model of rheumatoid arthritis in humans. These properties were not evident when equimolar mixtures of tolmetin sodium and glycine were administered concurrently. Pharmacokinetic analyses revealed that TGA was absorbed completely and hydrolyzed to tolmetin in the female adjuvant arthritic rat. The combined effects of absorption, distribution and hydrolysis of TGA produced lower peak plasma tolmetin levels than an equivalent dose of tolmetin sodium, but plasma concentrations were sustained for a longer period of time contributing to an apparent increase in potency. Furthermore, TGA displayed a decreased propensity to cause gastrointestinal irritation compared to tolmetin sodium. Several additional amino acid amides of tolmetin were similar to the glycine amide in exhibiting increased potency and reduced gastrointestinal toxicity in comparison to equivalent doses of tolmetin sodium.
Numerical results are presented on the spectrum of the light scattered into the vacuum modes by a two-level atom driven by a strong ramped field of frequency smaller than the natural atomic ...frequency. The attention is focused on the role of the hyper-Raman part of the spectrum, which is shown to decrease dramatically with increasing ramp time. It is suggested that this may explain lack of experimental observation of the hyper-Raman lines. For zero ramp time, the numerical intensity of both high-order harmonics and hyper-Raman peaks is shown to agree satisfactorily with previous analytical predictions except in the region of overlap of the two series of peaks. This lends support for the suggestion that the plateau in the spectrum is related to quantum-mechanical interference between high-order harmonics and hyper-Raman processes. There is also good agreement between the numerical amplitude of the plateau and previous analytical predictions. A physical mechanism for the cut-off frequency which terminates the plateau, based on approximate energy conservation in hyper-Raman transitions, is presented and is shown to be in agreement with present numerical and previous analytical results.
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