Characterizing changes in MR images with color-coded Jacobians

Image registration is the process of establishing spatial correspondence between two images or between two image volumes. Registration can be achieved by rigid, elastic, or a combination of rigid and elastic transforms that attempt to bring the two images into coincidence. A rigid transform accounts for differences in positioning and an elastic transform describes deformations due to differences in tissue properties, temporal changes due to growth or atrophy, or differences between individuals. Deformation-based morphometry uses the resulting deformation fields from these transforms to evaluate differences between the images being registered. Three methods of registration were evaluated: rigid (affine) transformation, elastic optical flow transformation, and elastic spline transformation. All three methods produce vector deformation fields that map each point in one image to a point in the other image. A 12-color map of the transformation Jacobian was used to represent local volume changes. Using the three registration methods, color-mapped Jacobians were determined using a simulated three-dimensional block with known translation, rotation, expansion, contraction, and intensity modulations. Color-coded Jacobians were also generated for experimentally measured magnetic resonance image volumes of water-filled balloons and 7-year-old twin boys. Color-coded Jacobians overlaid on anatomical images provide a convenient method to identify regional tissue expansion and contraction.     

Fusion around the barrier for 7Li+12C

Fusion cross-sections for the ⁷Li + ¹²C reaction have been measured at energies above the Coulomb barrier by the direct detection of evaporation residues. The heavy evaporation residues with energies below 3 MeV could not be separated out from the α-particles in the spectrum and hence their contribution was estimated using statistical model calculations. The present work indicates that suppression of fusion cross-sections due to the breakup of ⁷Li may not be significant for ⁷Li + ¹²C reaction at energies around the barrier.     

Combined Photoredox and Carbene Catalysis for the Synthesis of Ketones from Carboxylic Acids**

As a key element in the construction of complex organic scaffolds, the formation of C−C bonds remains a challenge in the field of synthetic organic chemistry. Recent advancements in single-electron chemistry have enabled new methods for the formation of various C−C bonds. Disclosed herein is the development of a novel single-electron reduction of acyl azoliums for the formation of ketones from carboxylic acids. Facile construction of the acyl azolium in situ followed by a radical–radical coupling was made possible merging N-heterocyclic carbene (NHC) and photoredox catalysis. The utility of this protocol in synthesis was showcased in the late-stage functionalization of a variety of pharmaceutical compounds. Preliminary investigations using chiral NHCs demonstrate that enantioselectivity can be achieved, showcasing the advantages of this protocol over alternative methodologies.     

Loss of alignment gain in the πh 9/2[541 1/2−] ⊗ (νi 13/2)2 band in 167Tm and neighbouring odd-Z N = 98 nuclei

Theπh_9/2[541 1/2^?] band in ¹⁶⁷Tm has been studied through the ¹²⁴Sn(⁴⁸Ca, p4n)¹⁶⁷Tm reaction at E _beam = 210 MeV. The favoured signature of the πh_9/2[541 1/2^?] band is observed to spin 61/2h?. A remarkable small gain in aligned angular momentum at the AB-band crossing has been found. The crossing frequency and the gain in aligned angular momentum for ¹⁶⁷Tm are compared with data for the N = 98 isotones of Lu, Ta and Re, and contrasted with Cranked Shell Model predictions, based on frequency diabatic configurations. Large deviations are found for the gain in aligned angular momentum.     

Separation of peptides utilizing ultrahigh-temperature micellar electrokinetic chromatography

The use of ultrahigh column temperatures, up to 110 degrees C, in micellar electrokinetic capillary chromatography was investigated. The number of plates generated per unit time increased from 0.22 to 12.8 plates/s for separations at 15 degrees C and 110 degrees C, respectively. Ultrahigh-temperature micellar electrokinetic capillary chromatography was used for the separation of cyclic undecapeptides (cyclosporins). A minimum resolution of 1.39 was calculated for a critical peak pair at 110 degrees C, which is more than a 50% increase over resolution generated at 40 degrees C. During a run time of more than 90 min at 110 degrees C and at pH 9.3, no sample degradation or solvent boiling was observed.     

The evolution of photochemotherapy with psoralens and UVA (PUVA): 2000 BC to 1992 AD.

The therapeutic uses of naturally occurring psoralens in modern-day medicine (8-methoxypsoralen (8-MOP), 5-methoxypsoralen (5-MOP), 4,5',8-trimethylpsoralen, and a few other synthetic psoralens) have evolved through five stages of development. (1) In the historical period (2000 BC to 1930 AD), the pigment-stimulating properties of naturally occurring plants containing psoralens were described anecdotally. (2) The second period (1930-1960) dealing with the chemistry of psoralens involved extraction, identification of their structure, synthesis, and the relationship between chemical structure and their photoreactivity and pigment-stimulating properties. The treatment of vitiligo with oral and topical 8-MOP became popular. (3) In the third period (1960-1974), we witnessed a new beginning and the growth of basic science studies and clinical investigations into various biological properties of psoralens including action spectrum studies, mutagenesis and carcinogenesis studies, in vitro and in vivo photoreactivity studies of various psoralens with DNA, RNA, proteins, and pharmacological and toxicological studies in vitiligo patients undergoing long-term therapy for repigmentation. (4) The fourth period (1974-1988) is recognized as the period of photochemotherapy and the development of the science of photomedicine which established the therapeutic effectiveness of psoralens in combination with newly developed UV irradiation systems that emitted high-intensity UVA radiation in the treatment of severe psoriasis, mycosis fungoides, and over 16 other skin diseases. The effectiveness of PUVA (psoralen + UVA) was confirmed by well controlled clinical trials in thousands of patients, both in the USA and in European countries. Combination therapy with oral retinoids and PUVA contributed to greater effectiveness and long-term safety of psoralen photochemotherapy. (5) In the fifth period (1989 and beyond), psoralens are now emerging as photochemoprotective agents against non-melanoma skin cancers and as immunologic modifiers in the management of certain patients with disorders of circulating T-cells using new techniques of photopheresis. In the final analysis, perhaps the application of pharmacological and therapeutic concepts and principles of using psoralens in combination with UVA has contributed to the development of a new science of photomedicine in which the interaction between basic scientists, photobiologists, and physicians has produced both basic and new clinical knowledge for the care and control of human suffering.     

Automation of a neutron diffractometer for analysis of residual stress inside complex engineering components

Residual stress measurement using neutron diffraction is becoming an increasingly important tool in engineering stress analysis. To this effect, a new generation of dedicated engineering strain instruments are being built at neutron sources, offering considerable improvements in both counting time and spatial resolution. Alongside these improvements, measurements in complex geometry prototype components are increasingly in demand. As a result, there is a strong drive towards integrated sample positioning systems that allow for simplified setup and operating of experiments on components with complex geometries.     

The prediction of nucleophilic attacking sites via determinants of ‘active’ frontier and near-frontier orbitals

A method for computing the most favourable initial attacking site for a nucleophile on a transition metal complex is described, and applied to the nucleophilic substitution and addition reactions of fluoromethane, and the cationic complexes [BFe(CO)₃]⁺ (B = C₆H₇ and C₇H₉). The reactions considered are classified according to whether they are frontier or non-frontier orbitally or charge controlled. It is found that initial attack on the (polyenyl)M(CO)₃ cations is always predicted to occur at the M(CO)₃ moiety, in agreement with the experimental observation of intermediates in several such reactions and suggesting that the existence of these species is a general phenomenon.     

Dermatological Risk of Indoor Ultraviolet Exposure from Contemporary Lighting Sources¶†‡§

Discussions of risks and implications of cutaneous exposure to indoor lighting, including hypothetical contribution to causality of melanoma, have mainly concentrated on ultraviolet (UV) A and B (UVA, UVB) spectral emissions from fluorescent bulbs. Only studies of quartz halogen lamps have suggested that users might sustain UVC‐induced injury. Examination of light sources in the home and school of a child with xeroderma pigmentosum revealed that several different types emitted surprising levels of UV. Our purpose was to assess the extent of UV emissions from a variety of commonly used light sources to identify potential dermatological risks. UV and visible spectral emissions of commercially obtained lamps of several types were measured using a calibrated spectral radiometer traceable to the National Institute of Standards and Technology. Indoor light sources including fluorescent, quartz halogen and even tungsten filament incandescent lamps provided UVA, UVB and sometimes UVC emissions. Intensities of some emissions were of similar magnitude to those in sunlight. Chronic exposure to indoor lighting may deliver unexpected cumulative UV exposure to the skin and eyes. Patients with UV‐exacerbated dermatoses should be cautioned about potential adverse reactions from indoor lighting.