1,925 research outputs found
The relationships of the enigmatic gastropod Tritonoharpa (Neogastropoda): New data on early neogastropod evolution?
In this paper, the relationships of Tritonoharpa Dall, 1908, within Neogastropoda are discussed. Tritonoharpa is indeed similar to Colubraria in the morphology of its head-foot, pallial complex, reproductive and excretory systems, in the presence of an extremely long and coiled proboscis, and a very large stomach. However, it differs from Colubraria in the rest of its foregut anatomy, revealing a cancellariid affinity, and a typical nematoglossan radula. The molecular data confirms Beu and Maxwell's placement of Tritonoharpa in the Cancellariidae, close to Plesiotriton. It is also suggested that cancellariids may be the sister-group to the rest of neogastropods. Tritonoharpa has a rather large and well developed midgut gland, resembling the gland of Leiblein. As previously studied cancellarioideans have been shown to lack a well differentiated gland of Leiblein, the present study raises some interesting questions about the evolution of the foregut in Neogastropoda. In fact, if this glandular structure were confirmed as a true homologue of the gland of Leiblein, and the cancellarioideans proved to be the sister group to the remaining neogastropods, the possession of the gland should be considered a synapomorphy of the Neogastropoda
Fire in the Operating Room During Hypospadias Repair
Fire in the operating room (OR) is a very distressful and shocking occurrence with potential dramatic consequences. Despite safety rules and rigorous recommendations, such unintentional events do occur every so often. Notably, the vast majority of cases have been reported in the adult population, with very few pediatric cases described to date. Herein, we report on a 16-month-old boy undergoing reconstructive surgery for penoscrotal hypospadias, who experienced an OR fire most likely related to the use of alcohol-based solution ignited by monopolar electrocautery
Virtual edge illumination and one dimensional beam tracking for absorption, refraction, and scattering retrieval
We propose two different approaches to retrieve x-ray absorption, refraction, and scattering signals using a one dimensional scan and a high resolution detector. The first method can be easily implemented in existing procedures developed for edge illumination to retrieve absorption and refraction signals, giving comparable image quality while reducing exposure time and delivered dose. The second method tracks the variations of the beam intensity profile on the detector through a multi-Gaussian interpolation, allowing the additional retrieval of the scattering signal
Magnetoelectric Effects on Composite Nano Granular Films
Employing a new experimental technique to measure magnetoelectric response
functions, we have measured the magnetoelectric effect in composite films of
nano granular metallic iron in anatase titanium dioxide at temperatures below
50 K. A magnetoelectric resistance is defined as the ratio of a transverse
voltage to bias current as a function of the magnetic field. In contrast to the
anomalous Hall resistance measured above 50 K, the magnetoelectic resistance
below 50 K is significantly larger and exhibits an even symmetry with respect
to magnetic field reversal . The measurement technique required
attached electrodes in the plane of the film composite in order to measure
voltage as a function of bias current and external magnetic field. To our
knowledge, the composite films are unique in terms of showing magnetoelectric
effects at low temperatures, 50 K, and anomalous Hall effects at high
temperatures, 50 K.Comment: ReVTeX, 2 figures, 3 page
Highly-functionalised difluorinated cyclohexane polyols via the Diels–Alder reaction : regiochemical control via the phenylsulfonyl group
A difluorinated dienophile underwent cycloaddition reactions with a range of furans to afford cycloadducts whichcould be processed regio- and stereoselectively via episulfonium ions, generated by the reaction between their alkenyl groups and phenylsulfenyl chloride. The oxabicyclic products were oxidised to the phenylsulfonyl level and ring opened via E1CB or reductive desulfonative pathways to afford, ultimately, difluorinated cyclohexene or cyclohexane polyols
Apparent superluminal advancement of a single photon far beyond its coherence length
We present experimental results relative to superluminal propagation based on
a single photon traversing an optical system, called 4f-system, which acts
singularly on the photon's spectral component phases. A single photon is
created by a CW laser light down{conversion process. The introduction of a
linear spectral phase function will lead to the shift of the photon peak far
beyond the coherence length of the photon itself (an apparent superluminal
propagation of the photon). Superluminal group velocity detection is done by
interferometric measurement of the temporal shifted photon with its correlated
untouched reference. The observed superluminal photon propagation complies with
causality. The operation of the optical system allows to enlighten the origin
of the apparent superluminal photon velocity. The experiment foresees a
superluminal effect with single photon wavepackets.Comment: 11 pages, 2 figure
Signal amplification by combining two advanced immunohistochemical techniques
The immunohistochemical techniques known as EnVision™+ System (EVS) and Mirror Image Complementary Antibody (MICA) were recently introduced into laboratory practice because of their high sensitivity. In this paper these techniques were compared and their sequences combined to obtain a new method possibly more sensitive than the original ones. The immunohistochemical staining employing the avidin-biotin complex (ABC), largely used as routine, was adopted as a term of comparison. Samples from the small and large intestine of pigs and sheep were fixed in Bouin and embedded in Paraplast. The primary antibodies utilized were directed against the neuronal nitric oxide synthase (nNOS), vasoactive intestinal polypeptide (VIP) and chromogranin A (Cr A). Targets of these antibodies were nerve structures of the intestinal wall, as well as endocrine cells scattered in the mucosa of the bowel, defined neuroendocrine cells or paraneurons. The EVS method appeared as slightly superior to the MICA method regarding sensitivity of detection. The EVS/MICA (combined) method resulted four/eight times more effective than the original techniques regarding sensitivity of detection and staining intensity, both at low and high dilutions of the primary antibodies. Of these latter, immunopositive structures were still clearly identifiable, at a dilution of 1:256,000. Such efficiency could be explained by the high number of revealing molecules of peroxidase contained in the new sequence. The application of the combined method is recommended when a small quantity of tissue antigens needs to be detected immunohistochemically
Presence of orexin A and orexin 1 receptor in the buffalo prostate
The orexins A and B are two peptides discovered initially in the rat lateral hypothalamus involved in the regulation of some body functions such as food intake, sleep/wake cycle, arterial pressure and heart rate. They interact with two receptors defined "orexin receptors 1 and 2", the first of which shows high selectivity for orexin A and the second binds both the peptides. In this preliminary study the presence of orexin A and orexin 1 receptor in the prostate of the buffalo Bubalus bubalis has been described utilizing the immunohistochemical avidin-biotin technique. The orexin A- and orexin 1 receptor- positive prostatic cells are very numerous and belong to the normal exocrine cytotype which makes up the glandular parenchyma. The role played by orexin A in the genital tract is poorly known. The peptide is retained to stimulate testosterone secretion and to inhibit spermatogonia proliferation in the rat testis
Investigation of the steady engulfment regime in a three-dimensional T-mixer
The steady engulfment regime in a fully three-dimensional micro T-mixer is investigated. This regime is of significant interest for applications since it implies high mixing between the flow streams entering the device. Direct numerical simulations are first used to characterize this regime. In particular, the main vortical structures typical of the engulfment regime and their effects on mixing are investigated. Three-dimensional linear stability analysis is successively applied to the characterization of the instability leading to the engulfment regime. The critical Reynolds number and the global unstable mode are first computed for a configuration characterized by fully-developed inlet velocity conditions. The sensitivity of this instability to a generic modification of the base flow is then investigated, thanks to the computation of the mode adjoint to the direct unstable one. Finally, this kind of analysis is specialized to investigate the effect of a perturbation of the velocity distribution at the inlet of the T-mixer. Sensitivity analysis shows that non-fully developed inlet velocity conditions lead to an increase of the critical Reynolds number. More generally, the sensitivity maps can be used for the design of control strategies aimed at promoting or inhibiting the engulfment. An example is provided for a control based on blowing/suction through the mixer walls
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