Hinter Gittern: Ein einzelnes Molekül des Proteins Cytochrom c wurde in einem starren tetraedrischen DNA‐Käfig eingesperrt (siehe Bild). Im zentralen Hohlraum sollte Platz für eine Kugel mit etwa 2.6 ...nm Radius sein, z. B. für ein 60 kDa schweres globuläres Protein (Mr von Cytochrom c: 12.4 kDa). Der Befund belegt das Potenzial von DNA‐Behältern als Wirkstofftransportsysteme.
In previous work, a conductivity-modulated field-effect transistor (COMFET) having drastically reduced on-resistance was described; that device was based on n-channel MOS technology. In this letter, ...we report the development of a complementary device-the p-channel COMFET. These new p-channel COMFET's have demonstrated dc on-resistance values as low as 0.07 Ω at 20 A (for a 3 mm × 3 mm pellet), while providing forward blocking voltages of 200-400 V. To our knowledge, this on-resistance value (normalized to the same active area) is lower than that of any p-channel power MOSFET (even those with blocking voltages of only 100 V) and as much as 30 times less than that of a p-channel MOSFET with a comparable blocking-voltage capability. Using suitable minority-carrier-lifetime control techniques, drain-current-decay times have been reduced from ≈ 30 µs to below 1 µs.
The air–sea exchange of heat and carbon in the Southern Ocean (SO) plays an important role in mediating the climate state. The dominant role the SO plays in storing anthropogenic heat and carbon is a ...direct consequence of the unique and complex ocean circulation that exists there. Previous generations of climate models have struggled to accurately represent key SO properties and processes that influence the large-scale ocean circulation. This has resulted in low confidence ascribed to twenty-first-century projections of the state of the SO from previous generations of models. This analysis provides a detailed assessment of the ability of models contributed to the sixth phase of the Coupled Model Intercomparison Project (CMIP6) to represent important observationally based SO properties. Additionally, a comprehensive overview of CMIP6 performance relative to CMIP3 and CMIP5 is presented. CMIP6 models show improved performance in the surface wind stress forcing, simulating stronger and less equatorward-biased wind fields, translating into an improved representation of the Ekman upwelling over the Drake Passage latitudes. An increased number of models simulate an Antarctic Circumpolar Current (ACC) transport within observational uncertainty relative to previous generations; however, several models exhibit extremely weak transports. Generally, the upper SO remains biased warm and fresh relative to observations, and Antarctic sea ice extent remains poorly represented. While generational improvement is found in many metrics, persistent systematic biases are highlighted that should be a priority during model development. These biases need to be considered when interpreting projected trends or biogeochemical properties in this region.
Celotno besedilo
Dostopno za:
BFBNIB, DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Multidetector computed tomographic angiography (CTA) was evaluated alone and with imaging of the pelvic and thigh veins (CTA–CTV). As compared with a reference standard for the diagnosis of acute ...pulmonary embolism, CTA–CTV had a higher sensitivity than CTA alone, with similar specificity.
Multidetector computed tomographic angiography (CTA) was evaluated alone and with imaging of the pelvic and thigh veins (CTA–CTV). CTA–CTV had a higher sensitivity than CTA alone, with similar specificity.
Uncertainty persists about the accuracy of contrast-enhanced multidetector computed tomographic angiography (CTA) for the diagnosis of pulmonary embolism. The sensitivity of single-slice CTA has ranged from 60
1
to 100
2
percent, and the specificity has ranged from 81
1
to 100
3
percent. A previous review focused on the diagnostic accuracy of single-slice CTA.
4
Visualization of segmental and subsegmental pulmonary arteries is substantially better with four-slice CTA and thin collimation (1.25 mm) than with single-slice CTA.
5
,
6
In two studies of fewer than 100 patients, sensitivities for the detection of pulmonary embolism with four-slice CTA have been reported to be 96 percent
7
and . . .
Objective
This collaboration between the American College of Rheumatology and the American Association of Hip and Knee Surgeons developed an evidence‐based guideline for the perioperative management ...of antirheumatic drug therapy for adults with rheumatoid arthritis (RA), spondyloarthritis (SpA) including ankylosing spondylitis and psoriatic arthritis, juvenile idiopathic arthritis (JIA), or systemic lupus erythematosus (SLE) undergoing elective total hip (THA) or total knee arthroplasty (TKA).
Methods
A panel of rheumatologists, orthopedic surgeons specializing in hip and knee arthroplasty, and methodologists was convened to construct the key clinical questions to be answered in the guideline. A multi‐step systematic literature review was then conducted, from which evidence was synthesized for continuing versus withholding antirheumatic drug therapy and for optimal glucocorticoid management in the perioperative period. A Patient Panel was convened to determine patient values and preferences, and the Grading of Recommendations Assessment, Development and Evaluation methodology was used to rate the quality of evidence and the strength of recommendations, using a group consensus process through a convened Voting Panel of rheumatologists and orthopedic surgeons. The strength of the recommendation reflects the degree of certainty that benefits outweigh harms of the intervention, or vice versa, considering the quality of available evidence and the variability in patient values and preferences.
Results
The guideline addresses the perioperative use of antirheumatic drug therapy including traditional disease‐modifying antirheumatic drugs, biologic agents, tofacitinib, and glucocorticoids in adults with RA, SpA, JIA, or SLE who are undergoing elective THA or TKA. It provides recommendations regarding when to continue, when to withhold, and when to restart these medications, and the optimal perioperative dosing of glucocorticoids. The guideline includes 7 recommendations, all of which are conditional and based on low‐ or moderate‐quality evidence.
Conclusion
This guideline should help decision‐making by clinicians and patients regarding perioperative antirheumatic medication management at the time of elective THA or TKA. These conditional recommendations reflect the paucity of high‐quality direct randomized controlled trial data.
The Southern Ocean (SO) is vital to Earth’s climate system due to its dominant role in exchanging carbon and heat between the ocean and atmosphere and transforming water masses. Evaluating the ...ability of fully coupled climate models to accurately simulate SO circulation and properties is crucial for building confidence in model projections and advancing model fidelity. By analyzing multiple biases collectively across large model ensembles, physical mechanisms governing the diverse mean-state SO circulation found across models can be identified. This analysis 1) assesses the ability of a large ensemble of models contributed to phase 5 of the Coupled Model Intercomparison Project (CMIP5) to simulate observationally based metrics associated with an accurate representation of the Antarctic Circumpolar Current (ACC), and 2) presents a framework by which the quality of the simulation can be categorized and mechanisms governing the resulting circulation can be deduced. Different combinations of biases in critical metrics including the magnitude and position of the zonally averaged westerly wind stress maximum, wind-driven surface divergence, surface buoyancy fluxes, and properties and transport of North Atlantic Deep Water entering the SO produce distinct mean-state ACC transports. Relative to CMIP3, the quality of the CMIP5 SO simulations has improved. Eight of the thirty-one models simulate an ACC within observational uncertainty (2σ) for approximately the right reasons; that is, the models achieve accuracy in the surface wind stress forcing and the representation of the difference in the meridional density across the current. Improved observations allow for a better assessment of the SO circulation and its properties.
Celotno besedilo
Dostopno za:
BFBNIB, DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
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