Abstract
The cranial appendage (headgear) is an iconic structure of modern ruminants, and four of the five extant pecoran families display morphological and physiological specialties. They probably ...share one origin from the same genetic basis, whereas the evolution of the cranial appendages is still debatable, especially in consideration of fossil taxa lacking headgear. Amphimoschus is an enigmatic pecoran that comprises no more than two species, mainly known from the late early/early middle Miocene of Western and Central Europe and considered not to possess any cranial appendages. Here, we present Amphimoschus xishuiensis sp. nov., discovered in the Tabenbuluk area, Gansu Province, China. The new species reveals the first evidence of cranial ornamentations in the genus, including a supraorbital bump, an antorbital protuberance and frontal thickening. In our phylogenetic analysis the genus was inferred as a basal member of the Bovoidea, and thus the cranial ornamentations of A. xishuiensis might provide insight into the early evolution of cranial appendages in Bovoidea. They could be interpreted as weapons to defend territories in intense intraspecific or interspecific competition during the late early Miocene.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
Net-shape forming of gears is under investigation by a number of researchers. The proposed new methods would reduce waste through chip elimination. Flat rolling of external-precision involute-helical ...gears is discussed in the current paper. This method is expected to have the additional advantage of producing stronger gears. The work-hardening effect on the critical regions of gear is investigated through the use of three-dimensional DEFORM finite element models (FEM). The simulation models were calibrated against designed experiments with a specific gear design. Also, current production gears were compared with gears manufactured through the new process. Samples were destructively tested to obtain metallurgical data. Hardness maps and grain-flow photographs were produced for the two groups of gears. Validation of FE modeling has opened the way for optimization of gear-rolling process through virtual design of experiments (DEX). It would be possible to vary FEM inputs such as blank material, gear specification, or die geometry and study the predicted impact on gear tooth strength.
ABSTRACT
BACKGROUND AND PURPOSE
Some patients with posterior reversible encephalopathy syndrome (PRES) present with atypical clinical and neuroimaging findings. The purpose of this study is to review ...the clinical and neuroimaging findings in patients diagnosed with PRES.
METHODS
We retrospectively included all patients diagnosed with PRES between January 2005 and March 2009. We reviewed demographic, clinical and laboratory data, neuroimaging findings, and prognosis.
RESULTS
Twenty‐four patients were included with a median age of 19 years. The clinical presentations included seizures (91.7%), headache (83.3%), visual disturbance (62.5%), encephalophathy (29.2%), and paralysis (8.3%). Co‐morbidities included systemic lupus erythematous (29.2%), kidney disease (20.8%), eclampsia (20.8%), renal artery stenosis (12.5%), Takayasu arteritis (4.2%), Sheehan's syndrome (4.2%), allergic purpura (4.2%), and acute intermittent porphyria (4.2%). Acute elevation of blood pressure was found in 22 patients (91.7%). Ten patients (41.7%) used steroids or immunosuppressants, three (12.5%) had acute renal failure before the symptoms. Atypical neuroimaging features included involvement of the frontal lobe (54.2%), basal ganglia (4.2%) or cortex (8.3%), and irreversible lesions (3/18, 16.7%).
CONCLUSIONS
A large proportion of patients with PRES may present with atypical neuroimaging findings. Apart from the known risk factors, such as hypertension, immunosuppressants, and renal failure of various etiologies may be the precipitants of PRES.
Coronary reperfusion has been the mainstay therapy for reduced infarct size after a heart attack. However, this intervention also results in myocardial injury by initiating a marked inflammatory ...reaction, and new treatments are keenly sought.
The basic-region leucine zipper protein, c-Jun is poorly expressed in the normal myocardium and is induced within 24 hours after myocardial ischemia-reperfusion injury. Synthetic catalytic DNA molecules (DNAzymes) targeting c-Jun (Dz13) reduce infarct size in the area-at-risk (AAR) regardless of whether it is delivered intramyocardially at the initiation of ischemia or at the time of reperfusion. Dz13 attenuates neutrophil infiltration, c-Jun and ICAM-1 expression in vascular endothelium, cardiomyocyte apoptosis, and the generation of reactive oxygen species in the reperfused myocardium. It inhibits infiltration into the AAR of complement 3 (C3), C3a receptor (C3aR), membrane attack complex-1 (Mac-1), or matrix metalloproteinase-2 (MMP-2) positive inflammatory cells. Dz13 also improves cardiac function without influencing myocardial vascularity or fibrosis.
These findings demonstrate the regulatory role of c-Jun in the pathogenesis of myocardial inflammation and infarction following ischemia-reperfusion injury, and inhibition of this process using catalytic DNA.
The upgrading of bioethanol to n-butanol has recently been a focus of considerable attention due to the advantages of n-butanol over bioethanol as a sustainable fuel. The efficiency of this reaction ...is highly dependent on the development of catalysts, where understanding how catalysts perform is essential. However, traditional catalysts are normally composed of several kinds of active sites that work together synergistically in reactions, making it challenging to identify the role that individual active sites play. Herein, we synthesized three chromium-based MOFs ((MIL-101(Cr), where MIL stands for Matériaux Institut Lavoisier) with different Lewis acidities but without any basic sites. The linear relationship between Lewis acidities and their dehydration and condensation abilities suggests that there is a competition between the ethanol dehydration to diethyl ether and acetaldehyde condensation on Lewis acids. Upon the introduction of Pd, the Lewis acidity also dominates the particle size of Pd and then the dehydrogenation and hydrogenating abilities of catalysts.
We have investigated the structural stabilities of iron arsenide compounds Ax(FeAs)1−x (A = alkali and alkaline-earth metals) by first principles calculations. We find that (i) all of the ...experimental “122” type structures with composition x=1/3 are stable; (ii) all of the “111” type structures with composition x=1/2 except CsFeAs are stable; (iii) K3FeAs with composition x=3/4 is stable. The predicted stable KFeAs, RbFeAs, SrFeAs, BaFeAs, K3FeAs have the As–Fe–As bond angles close to the ideal tetrahedral angles, indicating that they may be superconductors.
► Compounds AFeAs (A = K, Rb, Be, Mg, Ca, Sr, Ba) and K3FeAs are stable. ► Stable materials show different magnetic ground states. ► KFeAs, RbFeAs, SrFeAs, BaFeAs and K3FeAs may be superconductors.
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