Soft-Collinear Messengers: A New Mode in Soft-Collinear Effective Theory

It is argued that soft-collinear effective theory for processes involving both soft and collinear partons, such as exclusive B-meson decays, should include a new mode in addition to soft and collinear fields. These "soft-collinear messengers" can interact with both soft and collinear particles without taking them far off-shell. They thus can communicate between the soft and collinear sectors of the theory. The relevance of the new mode is demonstrated with an explicit example, and the formalism incorporating the corresponding quark and gluon fields into the effective Lagrangian is developed.Comment: 22 pages, 5 figures. Extended Section 6, clarifying the relevance of different types of soft-collinear interaction

The Design and Application of Target-Focused Compound Libraries

Target-focused compound libraries are collections of compounds which are designed to interact with an individual protein target or, frequently, a family of related targets (such as kinases, voltage-gated ion channels, serine/cysteine proteases). They are used for screening against therapeutic targets in order to find hit compounds that might be further developed into drugs. The design of such libraries generally utilizes structural information about the target or family of interest. In the absence of such structural information, a chemogenomic model that incorporates sequence and mutagenesis data to predict the properties of the binding site can be employed. A third option, usually pursued when no structural data are available, utilizes knowledge of the ligands of the target from which focused libraries can be developed via scaffold hopping. Consequently, the methods used for the design of target-focused libraries vary according to the quantity and quality of structural or ligand data that is available for each target family. This article describes examples of each of these design approaches and illustrates them with case studies, which highlight some of the issues and successes observed when screening target-focused libraries

Salmeterol's Extreme b2 Selectivity Is Due to Residues in Both Extracellular Loops and Transmembrane Domains

ABSTRACT Salmeterol is a long-acting b2-agonist, widely used as an inhaled treatment of asthma and chronic obstructive pulmonary disease. It has very high b2-affinity (log K D 28.95) and is very selective for the b2-adrenoceptor (1000-fold selectivity over the b1-adrenoceptor). This study used a mutagenesis approach to determine the exact amino acids in the human b2-adrenoceptor responsible for this very high selectivity. Wild-type b2-and b1-adrenoceptors, chimeric b2/b1-adrenoceptors, and receptors with single-point mutations were transfected into Chinese hamster ovary-K1 cells, and affinity and function were studied using [ ]cAMP accumulation. Extracellular loop 3 (and specifically amino acid K305) had the largest single effect by reducing salmeterol's affinity for the b2-adrenoceptor by 31-fold. H296 in transmembrane 6 also had a major effect (18-fold reduction in salmeterol affinity). Combining these, in the double mutant b2-H296K-K305D, reduced salmeterol's affinity by 275-fold, to within 4-fold of that of the b1-adrenoceptor, without affecting the affinity or selectivity of other b2-agonists (salbutamol, formoterol, fenoterol, clenbuterol, or adrenaline). Another important amino acid was Y308 in transmembrane 7, although this also affected the affinity and selectivity of other agonists. F194 in extracellular loop 2 and R304 in extracellular loop 3 also had minor effects. None of these mutations (including the double mutant b2-H296K-K305D) affected the efficacy or duration of action of salmeterol. This suggests that the high affinity and selectivity of salmeterol are due to specific amino acids within the receptor itself, but that the duration of action is at least in part due to other factors, for example lipophilicity

GaAs on Si epitaxy by aspect ratio trapping: analysis and reduction of defects propagating along the trench direction

The Aspect Ratio Trapping technique has been extensively evaluated for improving the quality of III-V heteroepitaxial films grown on Si, due to the potential for terminating defects at the sidewalls of SiO2 patterned trenches that enclose the growth region. However, defects propagating along the trench direction cannot be effectively confined with this technique. We studied the effect of the trench bottom geometry on the density of defects of GaAs fins, grown by metal-organic chemical vapor deposition on 300 mm Si (001) wafers inside narrow (<90 nm wide) trenches. Plan view and cross sectional Scanning Electron Microscopy and Transmission Electron Microscopy, together with High Resolution X-Ray Diffraction, were used to evaluate the crystal quality of GaAs. The prevalent defects that reach the top surface of GaAs fins are {111} twin planes propagating along the trench direction. The lowest density of twin planes, 8 108 cm 2, was achieved on “V” shaped bottom trenches, where GaAs nucleation occurs only on {111} Si planes, minimizing the interfacial energy and preventing the formation of antiphase boundaries

Aduroidbased planar EBG cavity resonator filter with improved quality factor

Abstract-A high- Duroid-based planar electromagnetic bandgap (EBG) cavity resonator/filter has been designed, fabricated, and tested. It was implemented in Rogers Duroid 5880 with standard board fabrication techniques. This filter provides a measured of 844 and a 0.91% bandwidth passband response at 10.63 GHz with a corresponding insertion loss of 2.76 dB

Thermal Imaging and Physiological Analysis of Cold-Climate Caribou-Skin Clothing

Protective clothing is essential for human existence in the Arctic, and caribou-skin clothing has played a pivotal&nbsp;role for millennia. Although people with northern experience often extol caribou-skin clothing, few scientific studies have investigated its properties. We used infrared thermal imaging in a pilot study to compare authentic caribou-skin clothing sewn by traditional Inuit seamstresses with two other types of cold-weather clothing: a standard-issue, Canadian army, winter uniform and an ensemble of modern retail clothing designed for extreme cold (a down anorak and snowmobile pants). To make the comparison, two subjects sequentially wore the three types of clothing—caribou skin, army uniform, and modern retail—in a still air, uniform thermal environment (where radiant temperatures of all environmental surfaces were equal to air temperature) at −21°C to −23°C (−6°F to −10°F). Thermal imaging quantifies the temperature of the outer surface of clothing, thereby providing key, functionally relevant information on the interface where clothing and environment meet. Under otherwise similar conditions, a low clothing surface temperature indicates superior clothing performance and a reduced rate of heat loss from the body to the environment. Caribou-skin clothing was similar to modern extreme-cold retail clothing: the whole-body composite surface temperature of our subjects wearing caribou-skin clothing was −22.1°C to −22.7°C, compared with −21.6°C in both subjects wearing the modern retail clothing. The army winter uniform (−18.9°C to −20.0°C) was inferior. These quantitative results were mirrored by the subjects’ subjective impressions. A particular advantage of thermal imaging is that it pinpoints locations in clothing where heat leaks occur. Although the two types of modern clothing exhibited heat leaks at zippered structures (even though fully closed), the caribou-skin clothing evaded such heat leaks by lacking such structures, because it is donned over the head. The integral hood characteristic of a caribou-skin parka was also superior in comparison to&nbsp;the detachable hood of the army uniform.Les vêtements de protection sont essentiels à l’existence humaine dans l’Arctique, et les vêtements en peau de caribou y jouent un rôle vital depuis des millénaires. Même si les gens qui ont évolué dans le Nord vantent souvent les mérites des vêtements en peau de caribou, peu d’études scientifiques ont été réalisées au sujet de leurs propriétés. Nous nous sommes servi d’imagerie thermique infrarouge dans le cadre d’une étude pilote visant à comparer les vêtements en peau de caribou authentique cousus par des couturières inuites traditionnelles à deux autres types de vêtements pour temps froid : un uniforme d’hiver standard de l’Armée canadienne et un ensemble de vêtements modernes du détail conçus pour des froids extrêmes (un anorak en duvet et des pantalons de motoneige). À des fins de comparaison, deux sujets ont porté, dans l’ordre séquentiel, les trois types de vêtements — vêtement en peau de caribou, uniforme de l’armée et vêtements modernes du détail — dans des conditions de vent nul thermique uniforme (où les températures radiatives de toutes les surfaces environnementales sont égales à la température de l’air) moyennant des températures allant de −21 °C à −23 °C (de −6 °F à −10 °F). L’imagerie thermique quantifie la température de la surface extérieure du vêtement, ce qui permet d’obtenir de l’information fonctionnellement pertinente et essentielle sur le point de rencontre du vêtement et de l’environnement. Dans des conditions par ailleurs semblables, la faible température du vêtement en surface indique un rendement supérieur pour ce vêtement et un taux réduit de perte de chaleur du corps à l’environnement. Les vêtements en peau de caribou ont donné des résultats semblables aux vêtements pour froid extrême modernes du détail : la température composite du corps entier de nos sujets portant les vêtements en peau de caribou variait de −22,1 °C à −22,7 °C, comparativement à −21,6 °C chez les deux sujets portant les vêtements modernes du détail. Les températures de l’uniforme d’hiver de l’armée étaient inférieures (de −18,9 °C à −20,0 °C).&nbsp;Ces résultats quantitatifs cadraient avec les impressions subjectives des sujets. Un des avantages particuliers de l’imagerie thermique, c’est qu’elle permet de repérer là où les pertes de chaleur se produisent dans les vêtements. Bien que les deux types de vêtements modernes perdaient de la chaleur à l’endroit des fermetures éclair (même si elles étaient fermées complètement), les vêtements en peau de caribou n’affichaient pas de telles pertes de chaleur en raison de l’absence de structures de ce genre parce que ces vêtements s’enfilent par la tête. Par ailleurs, il y a lieu de noter que la caractéristique intégrale du capuchon du&nbsp;parka en peau de caribou était également supérieure à celle du capuchon amovible de l’uniforme militaire

Monte Carlo simulation of expected outcomes with the AcrySof® toric intraocular lens

<p>Abstract</p> <p>Background</p> <p>To use a Monte Carlo simulation to predict postoperative results with the AcrySof^®Toric lens, evaluating the likelihood of over- or under-correction using various toric lens selection criteria.</p> <p>Methods</p> <p>Keratometric data were obtained from a large patient population with preoperative corneal astigmatism <= 2.50D (2,000 eyes). The probability distributions for toric marking accuracy, surgically induced astigmatism and lens rotation were estimated using available data. Anticipated residual astigmatism was calculated using a Monte Carlo simulation under two different lens selection scenarios.</p> <p>Results</p> <p>This simulation demonstrated that random errors in alignment, surgically induced astigmatism and lens rotation slightly reduced the overall effect of the toric lens. Residual astigmatism was statistically significantly higher under the simulation of surgery relative to an exact calculation (p < 0.05). The simulation also demonstrated that more aggressive lens selection criteria could produce clinically significant reductions in residual astigmatism in a high percentage of patients.</p> <p>Conclusion</p> <p>Monte Carlo simulation suggests that surgical variability and lens orientation/rotation variability may combine to produce small reductions in the correction achieved with the AcrySof^®Toric^®IOL. Adopting more aggressive lens selection criteria may yield significantly lower residual astigmatism values for many patients, with negligible overcorrections. Surgeons are encouraged to evaluate their AcrySof^®Toric^®outcomes to determine if they should modify their individual lens selection criteria, or their default surgically induced astigmatism value, to benefit their patients.</p

Dust Emission Features in NGC 7023 between 0.35 and 2.5 micron: Extended Red Emission (0.7 micron) and Two New Emission Features (1.15 and 1.5 micron)

We present 0.35 to 2.5 micron spectra of the south and northwest filaments in the reflection nebula NGC 7023. These spectra were used to test the theory of Seahra & Duley that carbon nanoparticles are responsible for Extended Red Emission (ERE). Our spectra fail to show their predicted second emission band at 1.0 micron even though both filaments exhibit strong emission in the familiar 0.7 micron ERE band. The northwest filament spectrum does show one, and possibly two, new dust emission features in the near-infrared. We clearly detect a strong emission band at 1.5 micron which we tentatively attribute to beta-FeSi_2 grains. We tentatively detect a weaker emission band at 1.15 micron which coincides with the location expected for transitions from the conduction band to mid-gap defect states of silicon nanoparticles. This is added evidence that silicon nanoparticles are responsible for ERE as they already can explain the observed behavior of the main visible ERE band.Comment: 9 pages, color figures, accepted to the ApJ, color and b/w versions available at http://dirty.as.arizona.edu/~kgordon/papers/ere_1um.htm

Intravascular Lithotripsy for Treatment of Calcified Coronary Lesions: Patient-Level Pooled Analysis of the Disrupt CAD Studies.

Abstract Objectives The aim of this pooled analysis was to assess the cumulative safety and effectiveness of coronary intravascular lithotripsy (IVL). Background The clinical outcomes of IVL to opt..