1,366 research outputs found
Roselliniella revealed as an overlooked genus of Hypocreales, with the description of a second species on parmelioid lichens
Based on newly obtained 28S rDNA sequences from Roselliniella atlantica and R. euparmeliicola sp. nov., the genus Roselliniella has to be placed in Hypocreales and not in Sordariales; however, the family placement could not be resolved from the sequences obtained. The mature ascospores are single-celled and brown, but young ascospores are hyaline and sometimes have a median septum. The new species occurs on a Parmelia s.str. species in China, and differs in 24 nucleotide substitution positions in the nu-LSU rDNA region and ascospore size from R. atlantica. In this case, small variations in ascospore sizes and shape prove to be phylogenetically and taxonomically informative. The two species occur in the same clade with 95 % jack-knife support. Roselliniella atlantica occurs on Xanthoparmelia and Melanohalea species in Europe, whereas R. euparmeliicola was found on the species of Parmelia s.str. DNA was successfully recovered from a dried specimen of R. atlantica collected in 1992. Two unidentified fungi were also recovered from the Chinese specimen, and these belong to Sordariomycetidae and Dothideomycetes; whether these two are additional fungi living endolichenically in the lichen host, saprobes, or contaminants could not be ascertained
The rheology of liquid crystal polymer blends.
The present studies are concerned with the observation and explanation of the interaction between liquid crystal and isotropic polymers. An investigation of the rheological behaviour has been carried out on blends containing small additions of a main chain thermotropic liquid crystal polymers using capillary rheometry. Samples of these blends were moulded and tested using a Hounsfield tensometer and a Houndsfield swinging arm impact rig. The addition of a small amount of liquid crystal polymer was found to have a major effect upon both the rheological and morphological properties of the base material. This indicates the liquid crystal polymer can be used as a processing aid. A reduction of viscosity was noticed in all of the tests carried out and is attributed to the change in morphology induced by the addition of liquid crystal polymer. It would be of great benefit to the polymer processor if an understanding of the mechanisms involved could be highlighted. It is felt that the large interfacial area created between the binodal and spinodal has a bearing on the viscosity reduction. The morphology was different for material in the centre and the skin regions. The characteristic skin/core morphology was seen in all samples produced above a critical amount of liquid crystal polymer and temperature. The interaction between the liquid crystal polymer and the base material was explained using a model which predicted the velocity profiles given the shear rate, consistency constant and shear thinning index of the blends. The interface position is important because on one side of the interface the material is subject to elongational forces and compressive forces on the other. The elongational forces extend the LCP domains inducing an imposed morphology on the isotropic matrix. This could be seen in extruded and injection moulded samples, in the form of highly orientated surface skin layers. The orientation in the skin layers improved the barrier properties of the resultant blends, by allowing molecules in the surface layers to pack more closely together
Molecular phylogenetic studies on the lichenicolous Xanthoriicola physciae reveal Antarctic rock-inhabiting fungi and Piedraia species among closest relatives in the Teratosphaeriaceae
The phylogenetic placement of the monotypic dematiaceous hyphomycete genus Xanthoriicola was investigated. Sequences of the nLSU region were obtained from 11 specimens of X. physciae, which formed a single clade supported both by parsimony (91 %), and maximum likelihood (100 %) bootstraps, and Bayesian Posterior Probabilities (1.0). The closest relatives in the parsimony analysis were species of Piedraria, while in the Bayesian analysis they were those of Friedmanniomyces. These three genera, along with species of Elasticomyces, Recurvomyces, Teratosphaeria, and sequences from unnamed rock-inhabiting fungi (RIF), were all members of the same major clade within Capnodiales with strong support in both analyses, and for which the family name Teratosphaeriaceae can be used pending further studies on additional taxa
Delayed evaluation of combat-related penetrating neck trauma
ObjectiveThe approach to penetrating trauma of the head and neck has undergone significant evolution and offers unique challenges during wartime. Military munitions produce complex injury patterns that challenge conventional diagnosis and management. Mass casualties may not allow for routine exploration of all stable cervical blast injuries. The objective of this study was to review the delayed evaluation of combat-related penetrating neck trauma in patients after evacuation to the United States.MethodFrom February 2003 through April 2005, a series of patients with military-associated penetrating cervical trauma were evacuated to a single institution, prospectively entered into a database, and retrospectively reviewed.ResultsSuspected vascular injury from penetrating neck trauma occurred in 63 patients. Injuries were to zone II in 33%, zone III in 33%, and zone I in 11%. The remaining injuries involved multiple zones, including the lower face or posterior neck. Explosive devices wounded 50 patients (79%), 13 (21%) had high-velocity gunshot wounds, and 19 (30%) had associated intracranial or cervical spine injury. Of the 39 patients (62%) who underwent emergent neck exploration in Iraq or Afghanistan, 21 had 24 injuries requiring ligation (18), vein interposition or primary repair (4), polytetrafluoroethylene (PTFE) graft interposition (1), or patch angioplasty (1). Injuries occurred to the carotid, vertebral, or innominate arteries, or the jugular vein. After evacuation to the United States, all patients underwent radiologic evaluation of the head and neck vasculature. Computed tomography angiography was performed in 45 patients (71%), including six zone II injuries without prior exploration. Forty (63%) underwent diagnostic arteriography that detected pseudoaneurysms (5) or occlusions (8) of the carotid and vertebral arteries. No occult venous injuries were noted. Delayed evaluation resulted in the detection of 12 additional occult injuries and one graft thrombosis in 11 patients. Management included observation (5), vein or PTFE graft repair (3), coil embolization (2), or ligation (1).ConclusionsPenetrating multiple fragment injury to the head and neck is common during wartime. Computed tomography angiography is useful in the delayed evaluation of stable patients, but retained fragments produce suboptimal imaging in the zone of injury. Arteriography remains the imaging study of choice to evaluate for cervical vascular trauma, and its use should be liberalized for combat injuries. Stable injuries may not require immediate neck exploration; however, the high prevalence of occult injuries discovered in this review underscores the need for a complete re-evaluation upon return to the United States
Complement peptide receptors in GtoPdb v.2021.3
Complement peptide receptors (nomenclature as agreed by the NC-IUPHAR subcommittee on Complement peptide receptors [107]) are activated by the endogenous ~75 amino-acid anaphylatoxin polypeptides C3a and C5a, generated upon stimulation of the complement cascade. C3a and C5a exert their functions through binding to their receptors (C3aR, C5aR1 and C5aR2), causing cell recruitment and triggering cellular degranulation that contributes to local inflammation
Complement peptide receptors in GtoPdb v.2023.1
Complement peptide receptors (nomenclature as agreed by the NC-IUPHAR subcommittee on Complement peptide receptors [113]) are activated by the endogenous ~75 amino-acid anaphylatoxin polypeptides C3a and C5a, generated upon stimulation of the complement cascade. C3a and C5a exert their functions through binding to their receptors (C3a receptor, C5a receptor 1 and C5a receptor 2), causing cell recruitment and triggering cellular degranulation that contributes to local inflammation
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