431 research outputs found
Group B Streptococcal Endocarditis in Obstetric and Gynecologic Practice
Background: We describe a case and review ten other instances of group B streptococcal endocarditis in the setting of obstetric and gynecologic practice reported since the last review in 1985. Case: Abortion remains a common antecedent event, but in contrast to earlier reports, most patients did not have underlying valvular disease, the tricuspid valve was most often involved, and mortality was low. Patients with tricuspid valve infection tended to have a subacute course, whereas those with aortic or mitral involvement typically had a more acute, fulminant course. Conclusion: Despite an improvement in mortality, morbidity remains high, with 8 of 11 patients having clinically significant emboli
Safety Measures During Cholecystectomy: Results of a Nationwide Survey
BACKGROUND: This study aimed to identify safety measures practiced by Dutch surgeons during laparoscopic cholecystectomy. METHOD: An electronic questionnaire was sent to all members of the Dutch Society of Surgery with a registered e-mail address. RESULTS: The response rate was 40.4% and 453 responses were analyzed. The distribution of the respondents with regard to type of hospital was similar to that in the general population of Dutch surgeons. The critical view of safety (CVS) technique is used by 97.6% of the surgeons. It is documented by 92.6%, mostly in the operation report (80.0%), but often augmented by photography (42.7%) or video (30.2%). If the CVS is not obtained, 50.9% of surgeons convert to the open approach, 39.1% continue laparoscopically, and 10.0% perform additional imaging studies. Of Dutch surgeons, 53.2% never perform intraoperative cholangiography (IOC), 41.3% perform it incidentally, and only 2.6% perform it routinely. A total of 105 bile duct injuries (BDIs) were reported in 14,387 cholecystectomies (0.73%). The self-reported major BDI rate (involving the common bile duct) was 0.13%, but these figures need to be confirmed in other studies. CONCLUSION: The CVS approach in laparoscopic cholecystectomy is embraced by virtually all Dutch surgeons. The course of action when CVS is not obtained varies. IOC seems to be an endangered skill as over half the Dutch surgeons never perform it and the rest perform it only incidentally
The reaction coordinate mapping in quantum thermodynamics
We present an overview of the reaction coordinate approach to handling strong
system-reservoir interactions in quantum thermodynamics. This technique is
based on incorporating a collective degree of freedom of the reservoir (the
reaction coordinate) into an enlarged system Hamiltonian (the supersystem),
which is then treated explicitly. The remaining residual reservoir degrees of
freedom are traced out in the usual perturbative manner. The resulting
description accurately accounts for strong system-reservoir coupling and/or
non-Markovian effects over a wide range of parameters, including regimes in
which there is a substantial generation of system-reservoir correlations. We
discuss applications to both discrete stroke and continuously operating heat
engines, as well as perspectives for additional developments. In particular, we
find narrow regimes where strong coupling is not detrimental to the performance
of continuously operating heat engines.Comment: 17 pages, 2 tables, 7 figures. As a chapter of: F. Binder, L. A.
Correa, C. Gogolin, J. Anders, and G. Adesso (eds.), "Thermodynamics in the
quantum regime - Recent Progress and Outlook", (Springer International
Publishing
Earthquakes, volcanoes, and rectified diffusion
Rectified diffusion is a mechanism by which a strain wave can rapidly pump volatiles into a bubble and therefore increase the pressure in a closed system. The dynamic strain of either distant regional tectonic earthquakes or local volcanic tremor can be translated to static strain inside a magma chamber via this process. We formulate a theory appropriate to the conditions of a magma chamber and calculate the increased pressure using realistic physical parameters. For a basaltic system initially at 130 MPa pressure, the excess pressure from rectified diffusion is between 0.4 and 4 MPa for a regional M≥8 earthquake. The pressure from rectified diffusion is often significantly above the static stress caused by deformation for documented cases of triggered eruptions and thus presents a more viable mechanism for triggering. Prolonged tremor can have a similar effect since the total pressure added increases linearly with the duration of the excitation
Second law, entropy production, and reversibility in thermodynamics of information
We present a pedagogical review of the fundamental concepts in thermodynamics
of information, by focusing on the second law of thermodynamics and the entropy
production. Especially, we discuss the relationship among thermodynamic
reversibility, logical reversibility, and heat emission in the context of the
Landauer principle and clarify that these three concepts are fundamentally
distinct to each other. We also discuss thermodynamics of measurement and
feedback control by Maxwell's demon. We clarify that the demon and the second
law are indeed consistent in the measurement and the feedback processes
individually, by including the mutual information to the entropy production.Comment: 43 pages, 10 figures. As a chapter of: G. Snider et al. (eds.),
"Energy Limits in Computation: A Review of Landauer's Principle, Theory and
Experiments
Quantum Fluctuation Theorems
Recent advances in experimental techniques allow one to measure and control
systems at the level of single molecules and atoms. Here gaining information
about fluctuating thermodynamic quantities is crucial for understanding
nonequilibrium thermodynamic behavior of small systems. To achieve this aim,
stochastic thermodynamics offers a theoretical framework, and nonequilibrium
equalities such as Jarzynski equality and fluctuation theorems provide key
information about the fluctuating thermodynamic quantities. We review the
recent progress in quantum fluctuation theorems, including the studies of
Maxwell's demon which plays a crucial role in connecting thermodynamics with
information.Comment: As a chapter of: F. Binder, L. A. Correa, C. Gogolin, J. Anders, and
G. Adesso (eds.), "Thermodynamics in the quantum regime - Fundamental Aspects
and New Directions", (Springer International Publishing, 2018
A decade of experience with injuries to the gallbladder
Article deposited according to publisher policy posted on SHERPA/RoMEO, 05/08/2010.YesFunding provided by the Open Access Authors Fund
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