Search

Critically ill patients are at risk for sepsis, and immunosuppressive mechanisms may prevail. Whether functional tests are helpful to detect immune alterations is largely unknown. Therefore, we tested the hypotheses that reactivity of peripheral blood mononuclear cells (PBMCs) to secrete interferon-γ (IFNγ) following stimulation in vitro is decreased in patients with early sepsis compared with postoperative patients. IFNγ secretion [enzyme-linked immunospot (ELISpot)] in response to stimulation with cytomegalovirus (CMV), pokeweed mitogen (PWM), muromonab-anti-CD3 (OKT3), and human leukocyte antigen (HLA)-DRA-mRNA expression and serum cytokine concentrations were repeatedly [days 1, 3, 5, and 7 after intensive care unit (ICU) admission] determined in patients with sepsis (n = 7) and patients undergoing major abdominal surgery (radical prostatectomy, cystectomy, n = 10). In a second cohort, HLA-DRA expression was assessed in 80 patients with sepsis, 30 postoperative patients, and 44 healthy volunteers (German clinical trials database no. 00007694). In patients with sepsis, IFNγ secretion (ELISpot) was decreased compared with controls after stimulation with CMV (P = 0.01), OKT3 (P = 0.02), and PWM (P = 0.02 on day 5), whereas unstimulated IFNγ secretion did not differ. HLA-DRA expression was also significantly decreased in patients with sepsis at all time points (P = 0.004) compared with postoperative surgical patients, a finding confirmed in the larger cohort. Reactivity of PBMCs to stimulation with CMV, PWM, and OKT3 as well as HLA-DRA expression was already decreased upon ICU admission in patients with sepsis when compared with postoperative controls, suggesting early depression of acquired immunity. ELISpot assays may help to clinically characterize the time course of immunocompetence in patients with sepsis. [ABSTRACT FROM AUTHOR]

The physisorption of molecular hydrogen in model carbon foams has been investigated from 50 K to room temperature. The study is carried out within the framework of the density functional theory for quantum liquids at finite temperatures. Calculations are performed in the grand canonical ensemble, i.e., the adsorbed fluid is assumed to be in equilibrium with an external gas of hydrogen molecules with concentrations ranging from 8×10-4 kg m-3 to n=71 kg m-3. It is shown that, while strong zero-point energy effects are present even at room temperature, the adsorption isotherms exhibit only a weak dependence on the explicit incorporation of the bosonic exchange symmetry of hydrogen molecules. The increase of the average particle density prevents the deviations from the Maxwell-Boltzmann statistics to become noticeable if the system is cooled down. The volumetric storage capacity of these materials at low temperatures is about one half of the U. S. Department of Energy goal, while the gravimetric capacity is still far from the standards required by mobile applications. The relation between the microscopic structure of the hydrogen fluid and the calculated adsorption properties is also addressed. [ABSTRACT FROM AUTHOR]

Austrian Power Grid (APG), the main TSO of Austria, uses different approaches to face challenges arising from stricter requirements regarding environmental issues, where audible noise (AN) is one of the important topics in this context.A innovative approach is pursued with a newly developed measurement system for audible noise monitoring of OHL. The main component of this system is an "optical microphone". The main benefit compared to a conventional capacitive-microphone, is the lack of any metal and moving parts. Thus, it can operate in the proximity of high electric fields without interferences. This opens up new possibilities for AN measurement on energized OHL. That facilitates the direct measurement of the acoustic immissions and not only the emissions.This is an advantage due to the fact, that measuring AN with conventional microphones has several limitations. The emitted noise from OHL is low compared to other emitters in the surroundings (cars, animals, farming, airplanes) and dependant on wind strength and direction and hence difficult to measure. Furthermore, there is the need for a place on the ground to set up the microphones and the power supply. An agreement with the landowners is mandatory.For the operation of the optical microphone additional components are necessary. A special suspension system was developed to mount the sensor head in the direct vicinity of a conductor. One requirement for the suspension is to keep the sensor head at an exact position underneath the conductor. In a close distance to the conductor, noise emissions vary in a wide range if the relative position is not properly fixed. The second requirement is that the suspension system itself doesn't influence the measurement. This means, that the electric field strength, which is a main parameter for AN, remains unchanged in the presence of the suspension system.The paper will present the solutions and innovations that have been developed, laboratory tests and installation methods to mount the optical microphone on a conductor. [ABSTRACT FROM AUTHOR]

We report density functional theory (DFT) calculations of the interactions of both Ni adsorbate and substitutional dopant with the ceria (110) and (100) surfaces to explain the origin of the activity of Ni/ceria catalysts. Our results indicate that the Ni adatom on the (110) surface prefers to adsorb on a two-fold bridge site over a hollow site up to 0.25 ML coverage, and the most stable position of a Ni adsorbate on the (100) surface was found to be the bridge site where the Ni atom is coordinated to two surface O atoms. The Ni+ oxidation state for the Ni adatom on the (110) surface was found to be more favorable than the Ni2+ state on the two-fold bridge site while on the (100) surface, a Ni adatom prefers its Ni2+ oxidation state over the Ni+ oxidation state. With increasing coverage, the binding energy of a Ni adatom on the (110) surface was found to decrease from −0.45 eV at 0.083 ML coverage to −0.32 eV at 0.25 ML coverage. Oxidation of the Ni adatom to Ni+ reduces one Ce4+ ion on the ceria surface to Ce3+ which preferred to be located next to the Ni+ ion in the nearest neighbor location. The Ce3+ ions on the (100) surface also prefer to stay in the vicinity of the adsorbed Ni atom, while they prefer to be located away from the Ni adatom on the (111) surface. No reduction of Ce4+ ions was observed upon substitution of Ce atoms by Ni atoms. Two Ni substituents preferred to be distributed on adjacent metal ion sites on the (110) surface. Ni adsorbate and substituent on the (110) surface were both found to induce significant structural distortions. In comparison to the pure ceria (110) and (100) surfaces, we show that a Ni adsorbate increases the energy required to create an oxygen vacancy while a Ni dopant reduces it. While multiple dopants on the (110) surface do reduce the vacancy formation energy, the degree of reduction is smaller compared to a single dopant indicating the presence of an optimum level of doping to obtain enhanced catalytic activity. [ABSTRACT FROM AUTHOR]

A combined theoretical and experimental approach demonstrates that nanocluster embedment into the pores of metal–organic frameworks (MOF) may be influenced by the chemical functionalisation of the MOF. Furthermore, this results in the surface functionalisation of the embedded nanoclusters, highlighting the potential of MOF scaffolds for the design and synthesis of novel functional materials. [ABSTRACT FROM AUTHOR]

A relatively new minimally invasive cardiological procedure, called the MitraClip™, does not require sternotomy and may have a number of advantages compared with open mitral valve surgery, but its acute impact on the pulmonary circulation and right ventricular function during general anaesthesia is unclear. We prospectively assessed the effects of the MitraClip procedure in 81 patients with or without pulmonary hypertension (defined as mean pulmonary artery pressure > 25 mmHg), who were anaesthetised using fentanyl (5 μg.kg−1), etomidate (0.2-0.3 mg.kg−1), rocuronium (0.5-0.6 mg.kg−1) and isoflurane. Placement of the MitraClip led to a 60% increase in mean (SD) right ventricular stroke work index (from 512 (321) to 820 (470) mmHg.ml.m−2, p < 0.0001), while mean (SD) pulmonary vascular resistance index decreased by 24% (522 (330) to 399 (244) dyn.s.cm−5, p < 0.0001), and mean (SD) pulmonary artery pressure decreased by 10% (30 (8) to 27 (8) mmHg, p < 0.0001). Patients with pulmonary hypertension experienced a similar decrease in mean pulmonary artery pressure compared with those without, and they also had a slight reduction in mean (SD) pulmonary artery occlusion pressure (22 (6) down to 20 (6) mmHg, p = 0.044). We conclude that successful MitraClip treatment for mitral regurgitation acutely improves right ventricular performance by reducing right ventricular afterload, regardless of whether patients have pre-operative pulmonary hypertension. [ABSTRACT FROM AUTHOR]

Background Remote ischaemic pre-conditioning attenuates myocardial injury. Because sulphonylurea drugs interfere with ischaemic and anaesthetic pre-conditioning, we assessed whether remote ischaemic pre-conditioning effects are altered in sulphonylurea-treated diabetics. Methods Using the database of our ongoing randomised, placebo-controlled study ( Clinical Trials.gov NCT01406678), we assessed the troponin I concentration area under curve (measurements: baseline, 1, 6, 12, 24, 48, and 72 h post-operatively) in sulphonylurea-treated diabetics ( n = 27) and non-diabetics ( n = 230) without and with remote ischaemic pre-conditioning (three 5-min periods of left upper arm ischaemia with 5-min reperfusion each) during isoflurane anaesthesia before two- to three-vessel coronary artery surgery. Results Remote ischaemic pre-conditioning in non-diabetic patients evoked a 41% decrease in the troponin I concentration area under curve (514 ng/ml × 72 h ± 600 vs. 302 ± 190, P = 0.001) but no change (404 ng/ml × 72 h ± 224 vs. 471 ± 383, P = 0.62) in sulphonylurea-treated diabetics. There was no significant correlation between the troponin I concentration area under curve and arterial glucose concentrations, and the latter was not an independent confounder. Conclusion Cardioprotection by remote ischaemic pre-conditioning during isoflurane anaesthesia is abolished in sulphonylurea-treated diabetics. [ABSTRACT FROM AUTHOR]

Copyright of Revista Chilena de Cirugia is the property of Sociedad de Cirujanos de Chile and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Background Remote ischemic preconditioning ( RIPC) of the myocardium by limb ischemia/reperfusion may mitigate cardiac damage, but its interaction with the anesthetic regimen is unknown. We tested whether RIPC is associated with differential effects depending on background anesthesia. Specifically, we hypothesized that RIPC during isoflurane anesthesia attenuates myocardial injury in patients undergoing coronary artery bypass graft ( CABG) surgery, and that effects may be different during propofol anesthesia. Methods In a randomized, single-blinded, placebo-controlled prospective study, serum troponin I concentration ( cTnI) (baseline, and 1, 6, 12, 24, 48, and 72 h postoperatively) were measured during isoflurane/sufentanil or propofol/sufentanil anesthesia with or without RIPC (three 5-min periods of intermittent left upper arm ischemia with 5 min reperfusion each) in non-diabetic patients ( n = 72) with three-vessel coronary artery disease ( NCT01406678). Results RIPC during isoflurane anesthesia ( n = 20) decreased the area under the cTnI time curve ( cTnI AUC) (−50%, 190 ± 105 ng/ml × 72 h vs. 383 ± 262 ng/ml × 72 h, P = 0.004), and the peak (7.3 ± 3.6 ng/ml vs. 11.8 ± 5.5, P = 0.004) and serial ( P < 0.041) postoperative cTnI when compared to isoflurane alone ( n = 19). In contrast, RIPC during propofol anesthesia ( n = 14) did not alter the cTnI AUC [263 ± 157 ng/ml × 72 h vs. 372 ± 376 ng/ml × 72 h ( n = 19), P = 0.318] or peak postoperative cTnI (10.1 ± 4.5 ng/ml vs. 12 ± 8.2, P = 0.444). None of the patients experienced harm or side effects from the intermittent left arm ischemia. Conclusion Thus, RIPC during isoflurane but not during propofol anesthesia decreased myocardial damage in patients undergoing CABG surgery. Accordingly, effects of RIPC evoked by upper limb ischemia/reperfusion depend on background anesthesia, with combined RIPC/isoflurane exerting greater beneficial effects under conditions studied. [ABSTRACT FROM AUTHOR]

Copyright of HNO is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The development of a quantitative model that correlates conduction in and sensing with p-type gas sensitive metal oxides is presented here. The theoretical results are confronted with the experimental data and found to be in very good agreement. The model also explains the differences between the performance of gas sensors based on n and p-type metal oxides and indicates the possible improvement routes. [ABSTRACT FROM AUTHOR]

The Cosmic Ray Telescope for the Effects of Radiation (CRaTER) on the Lunar Reconnaissance Orbiter (LRO) characterizes the radiation environment to be experienced by humans during future lunar missions. CRaTER measures the effects of ionizing energy loss in matter due to penetrating solar energetic protons (SEP) and galactic cosmic rays (GCR), specifically in silicon solid-state detectors and after interactions with tissue-equivalent plastic (TEP), a synthetic analog of human tissue. The CRaTER investigation quantifies the linear energy transfer (LET) spectrum in these materials through direct measurements with the lunar space radiation environment, particularly the interactions of ions with energies above 10 MeV, which penetrate and are detected by CRaTER. Combined with models of radiation transport through materials, CRaTER LET measurements constrain models of the biological effects of ionizing radiation in the lunar environment as well as provide valuable information on radiation effects on electronic systems in deep space. In addition to these human exploration goals, CRaTER measurements also provide new insights on the spatial and temporal variability of the SEP and GCR populations and their interactions with the lunar surface. We present here an overview of the CRaTER science goals and investigation, including: an instrument description; observation strategies; instrument testing, characterization, and calibration; and data analysis, interpretation, and modeling plans. [ABSTRACT FROM AUTHOR]

Vibration-based structural health monitoring of a vehicle crane was studied. The performance of different features to detect damage was investigated after eliminating the normal operational variations using factor analysis. Using eight accelerometers, ten AR parameters from each record were identified for damage detection. Also transmissibilities between sensors were estimated. Damage was introduced with additional masses at different locations of the structure. All damage cases could be detected from either features using control charts, but transmissibilities proved to be more sensitive to damage than the AR coefficients. [ABSTRACT FROM AUTHOR]

Vibration-based structural health monitoring of a vehicle crane was studied. The performance of different features to detect damage was investigated after eliminating the normal operational variations using factor analysis. Using eight accelerometers, ten AR parameters from each record were identified for damage detection. Also transmissibilities between sensors were estimated. Damage was introduced with additional masses at different locations of the structure. All damage cases could be detected from either features using control charts, but transmissibilities proved to be more sensitive to damage than the AR coefficients. [ABSTRACT FROM AUTHOR]

The possibility of stable non-carbon fullerenes is discussed for the case of phosphorus fullerene-like cage structures. On the basis of Density Functional Tight Binding calculations it is shown that many such cages correspond to metastable structures, but with increasing nuclearity become less stable with respect to separate molecular P4 units. Stability rules, known for carbon fullerenes, such as the “isolated pentagon rule”, do not reflect the different electronic and steric requirements of the phosphorus atom. The computational results tend to rule out phosphorus fullerenes. [ABSTRACT FROM AUTHOR]

Provides a description of a family of non-classical endohedral metallofullerenes that has a non-isolated-pentagon rule (IPR) cage of 68 carbon atoms. How bare carbon cages with adjacent pentagons have been predicted but not characterized in the study of fullerenes, nanotubes, and endohedral metallofullerenes; Information of how to prepare non-IPR family members.