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1.
Intracranial osteolipomas are rare lesions which occur in the region of the tuber cinereum. All cases reported to date have been incidental autopsy findings. We describe a patient who presented with a variety of neurological symptoms and had a typical osteolipoma surgically removed.  相似文献   
2.
In this paper, we present an application of sensitivity analysis for design verification of nuclear turbosets. Before the acquisition of a turbogenerator, energy power operators perform independent design assessment in order to assure safe operating conditions of the new machine in its environment. Variables of interest are related to the vibration behaviour of the machine: its eigenfrequencies and dynamic sensitivity to unbalance. In the framework of design verification, epistemic uncertainties are preponderant. This lack of knowledge is due to inexistent or imprecise information about the design as well as to interaction of the rotating machinery with supporting and sub-structures. Sensitivity analysis enables the analyst to rank sources of uncertainty with respect to their importance and, possibly, to screen out insignificant sources of uncertainty. Further studies, if necessary, can then focus on predominant parameters. In particular, the constructor can be asked for detailed information only about the most significant parameters.  相似文献   
3.
The cochlear implant, consisting of a compliant electrode carrier (ET) and embedded electrodes with contact wires, is an auditory neuroprosthesis, which is surgically inserted into the inner ear (cochlea) in order to create an auditory impression in the hearing-impaired patients. For simplification of the insertion, a fluidically actuated electrode carrier with a changeable curvature is presented. The deformation of the ET is specifically manipulated by applying pressure to its interior and also by a non-stretchable thin fibre or stripe embedded in its wall. An analytical examination of scaling properties allows to use scaled structures for models and measurements. In order to determine the geometry of the ET, a model-based synthesis – FE method combined with analytical modelling – is carried out. The synthesis resulted in a conical shape of the ET with a cylindrical cavity closed at one end and a fiber running parallel to the cavity. Experimental studies on a measuring geometry show a maximum deviation of 0,6 bar at a maximum internal pressure of 6 bar. The investigations show that the proposed synthesis method is suitable for the development of surgical instruments with adjustable curvature.  相似文献   
4.
Banding increases effectiveness of fertilizer P for alfalfa production   总被引:1,自引:0,他引:1  
A field experiment was conducted from 1992 to 1996 on an existing alfalfa (Medicago sativa Leyss) stand located on a P-deficient Black Chernozem (Typic Boroll) soil at Ponoka, Alberta, to compare the effectiveness of broadcasting (spread over the soil surface) versus banding (1.5 cm wide band placed 5 cm deep and 15 cm apart, using a coulter-type disc drill) of annual and one-time applications of P fertilizer on dry matter yield (DMY), P-use efficiency of applied P (PUE), protein yield (PY), recovery of fertilizer P (PR), net returns (NR) and non-renewable energy performance of alfalfa hay. There was a marked increase in DMY and PY from all the P application treatments in all the five years. Banding produced greater increase in DMY and PY than broadcasting, with both the annual (by 954 kg DMY ha–1 and 205 kg PY ha–1) and one-time application (by 742 kg DMY ha–1 and 173 kg PY ha–1) applications. The PUE (averaged across P rates and years) was greater with banding as compared to broadcasting by 58 kg DMY kg–1 P ha–1 for annual applications, and by 47 kg DMY kg–1 P ha–1 for one-time applications. In the same order, PR values were 16.0 and 12.1% greater with banding than broadcasting. Despite the higher costs of banding than broadcasting, net returns were significantly higher with banding in nearly all years. The differences between banding and broadcasting were generally greater at lower than at higher P rates. Based on the 5-year means, annual and one-time P applications produced similar increase in DMY, PY, PUE, PR and NR. In contrast, non-renewable energy inputs were higher for banding than broadcasting, but energy use efficiency was similar for both methods of application. In conclusion, method of P placement had the greatest effect on DMY, PY, PUE, PR, NR and energy performance, whereas annual and one-time applications showed similar results. The results suggest that alfalfa forage productivity and profitability can be improved by banding the P fertilizer with a coulter type disc in comparison to the conventional application method of broadcasting.  相似文献   
5.
The present longitudinal study traced the ideal self of 120 adolescents to the ideals that parents hold for themselves and for their children. Ideals were assessed using Q sorts for personality attributes and life goals. After permutation analysis was used to control for random similarity, moderate parent-child ideal-self similarity was evident. Three intermediate transmission steps accounted for this intergenerational similarity: (a) transfer of parents' ideal self to ideals for their children, (b) children's perception, and (c) acceptance of these parental ideals. The last 2 processes related to parenting practices, with parental warmth augmenting parent-child concordance and restrictiveness reducing it. Compared with boys' ideal self, that of girls was more similar to the ideals that parents hold for their children and for themselves. Analyses of patterns over time suggested a growth of ideal-self stability across adolescence. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
6.
In view of the potential pathophysiological and therapeutic implications, presynaptic 5-HT auto- and heteroreceptors have been identified and characterized in isolated human tissues and their functional role has been determined. Such investigations have been carried out in different laboratories including that of the authors. Basic evidence for the involvement of inhibitory 5-HT receptors in modulation of 5-HT release in the cerebral cortex was obtained in slices: exogenous 5-HT inhibited 5-HT release in a manner susceptible to blockade by methiothepin, which given alone facilitated 5-HT release, probably by preventing endogenous 5-HT from activating the inhibitory receptors. The latter receptors are located on the 5-HT nerve terminals themselves, since 5-HT (and sumatriptan) also inhibited 5-HT release from cortical synaptosomes. Their pharmacological properties conform to those of the 5-HT1D class. Subclassification (5-HT1D alpha or 5-HT1D beta) has been tried with ketanserin which has an at least 60 times higher affinity for 5-HT1D alpha (pki = 7.1) than 5-HT1D beta receptors. Since ketanserin (0.32 microM) did not affect the concentration-response curve for 5-carboxamidotryptamine (5-CT), the presynaptic 5-HT autoreceptor may belong to the 5-HT1D beta rather than the 5-HT1D alpha subtype. The sympathetic nerve terminals of the human saphenous vein are endowed with inhibitory 5-HT1D beta heteroreceptors, as indicated by the potency ratio of several 5-HT receptor agonists in inhibiting noradrenaline release in strips of this blood vessels and by the ability of methiothepin, but not of ketanserin 0.3 microM, to act as an antagonist. Noradrenergic nerves in the dura mater, which probably innervate its microvasculature, may also be endowed with inhibitory 5-HT receptors, since 5-HT inhibited noradrenaline release from this tissue. In strips of atrial appendages, 5-HT receptor agonists (e.g. 5-HT, 5-CT and sumatriptan) inhibited noradrenaline release at potencies which are correlated with their ki values at 5-HT1D alpha and 5-HT1D beta receptors. Since this inhibitory effect was antagonized by ketanserin (0.3 but not 0.03 microM) and methiothepin, the presynaptic 5-HT receptor in this tissue may belong to the 5-HT1D alpha subtype. However, this conclusion needs further confirmation by experiments with more potent and subtype-selective antagonists of 5-HT1D alpha and 5-HT1D beta receptors.  相似文献   
7.
We investigated 10 sensitized and 10 nonsensitized workers from a pharmaceutic factory who had been exposed to powdered trypsin, chymotrypsin, bromelain, papain, amylase, and lipase. Ten nonallergic subjects served as a control group. Titrated skin prick tests (SPT), RAST, and immunoblot studies were performed with all six enzymes. SPT reactivity revealed multiple sensitizations to proteolytic enzymes, i.e., papain (specifically sensitized/total number of sensitizations: 9/10), trypsin (8/10), chymotrypsin (8/10), and bromelain (7/10) and appeared to be more frequent and more pronounced than sensitizations to amylase (3/10) or lipase (3/10). The low molecular weight of proteolytic enzymes (20-30 kDa) and their biologic activity might facilitate mucosal penetration more easily and thus-compared to amylase and lipase-permit an immune response and induction of allergic hypersensitivity. Immunoblot studies demonstrated IgG-binding bands in both SPT-positive and -negative workers, indicating exposure to the enzymes, but not in 10 unexposed control subjects. IgE-binding bands of the enzymes were detected only in workers with a positive SPT reaction and/or a positive RAST result. IgG bands were more frequent and the IgG/IgE ratio was increased in workers without allergic complaints compared to symptomatic workers. This might indicate that high levels of specific IgG antibodies to enzymes are associated with an immune response lacking allergic manifestations in spite of IgE-mediated sensitizations to the enzymes. Atopic subjects were at greater risk of developing IgE-mediated sensitization (7/10) and allergic symptoms to enzymes (5/7). However, even without risk of atopy, IgE-mediated hypersensitivity occurred in a few subjects (3/13) exposed to enzymes by inhalation for prolonged periods of time.  相似文献   
8.
One reason for the universal appeal of music lies in the emotional rewards that music offers to its listeners. But what makes these rewards so special? The authors addressed this question by progressively characterizing music-induced emotions in 4 interrelated studies. Studies 1 and 2 (n = 354) were conducted to compile a list of music-relevant emotion terms and to study the frequency of both felt and perceived emotions across 5 groups of listeners with distinct music preferences. Emotional responses varied greatly according to musical genre and type of response (felt vs. perceived). Study 3 (n = 801)--a field study carried out during a music festival--examined the structure of music-induced emotions via confirmatory factor analysis of emotion ratings, resulting in a 9-factorial model of music-induced emotions. Study 4 (n = 238) replicated this model and found that it accounted for music-elicited emotions better than the basic emotion and dimensional emotion models. A domain-specific device to measure musically induced emotions is introduced--the Geneva Emotional Music Scale. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
9.
The development of drug resistance remains a critical problem for current HIV‐1 antiviral therapies, creating a need for new inhibitors of HIV‐1 replication. We previously reported on a novel anti‐HIV‐1 compound, N2‐(phenoxyacetyl)‐N‐[4‐(1‐piperidinylcarbonyl)benzyl]glycinamide ( 14 ), that binds to the highly conserved phosphatidylinositol (4,5)‐bisphosphate (PI(4,5)P2) binding pocket of the HIV‐1 matrix (MA) protein. In this study, we re‐evaluate the hits from the virtual screen used to identify compound 14 and test them directly in an HIV‐1 replication assay using primary human peripheral blood mononuclear cells. This study resulted in the identification of three new compounds with antiviral activity; 2‐(4‐{[3‐(4‐fluorophenyl)‐1,2,4‐oxadiazol‐5‐yl]methyl})‐1‐piperazinyl)‐N‐(4‐methylphenyl)acetamide ( 7 ), 3‐(2‐ethoxyphenyl)‐5‐[[4‐(4‐nitrophenyl)piperazin‐1‐yl]methyl]‐1,2,4‐oxadiazole ( 17 ), and N‐[4‐ethoxy‐3‐(1‐piperidinylsulfonyl)phenyl]‐2‐(imidazo[2,1‐b][1,3]thiazol‐6‐yl)acetamide ( 18 ), with compound 7 being the most potent of these hits. Mechanistic studies on 7 demonstrated that it directly interacts with and functions through HIV‐1 MA. In accordance with our drug target, compound 7 competes with PI(4,5)P2 for MA binding and, as a result, diminishes the production of new virus. Mutation of residues within the PI(4,5)P2 binding site of MA decreased the antiviral effect of compound 7 . Additionally, compound 7 displays a broadly neutralizing anti‐HIV activity, with IC50 values of 7.5–15.6 μM for the group M isolates tested. Taken together, these results point towards a novel chemical probe that can be used to more closely study the biological role of MA and could, through further optimization, lead to a new class of anti‐HIV‐1 therapeutics.  相似文献   
10.
Sarcoidosis may also present as an extra- or intra-axial mass involving the central nervous system. These lesions are sometimes operated upon, because a neoplasm is suspected. We report two cases of unusual tumour-like extra- and intra-axial sarcoidosis. The extra-axial mass was just medial to the jugular foramen. Its morphology and signal characteristics differed from the more common lesions in this area. The intra-axial mass was in the temporal lobe, with only minor leptomeningeal involvement. Extra-axial sarcoidosis can be confused with a meningioma because these lesions can give relatively low signal on T2-weighted images. Intra-axial masses are presumed to represent a propagation and fusion of multiple leptomeningeal granulomas through the Virchow-Robin spaces in the brain; this pattern can be sought on contrast-enhanced T1-weighted images.  相似文献   
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