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OBJECTIVE: The aim of this investigation was to report on the radiographic interpretation of the hard palate and nasal fossa floor in panoramic radiographs by studying different skulls, x-ray machines, and head positions in relationship to the Frankfort plane before and after ostectomy. STUDY DESIGN: Twenty dry human skulls were radiographed with three different panoramic x-ray machines in three different positions. Three of the skulls were submitted to different ostectomies. RESULTS: Multiple images of the hard palate and nasal fossa floor were present in 96.12% of the radiographs. Single images (3.88%) occurred only in the "chin up" position. CONCLUSIONS: The lower image represents the nasal fossa floor, especially its lateral and anterior limits. The upper images are double real images mainly formed by the junction of the nasal septum with the nasal fossa floor and possibly by posterior parts of the hard palate and nasal fossa floor. All images overlap in the "chin up" position becoming a single image. The most common shape of the anatomic landmark was wide angle "W" (58.33%). Other shapes present in positions "chin up" and "chin down" indicate patient positioning errors. The x-ray machines did not influence the results.  相似文献   
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The extraocular fibrosis syndromes are congenital ocular-motility disorders that arise from dysfunction of the oculomotor, trochlear, and abducens nerves and/or the muscles that they innervate. Each is marked by a specific form of restrictive paralytic ophthalmoplegia with or without ptosis. Individuals with the classic form of congenital fibrosis of the extraocular muscles (CFEOM1) are born with bilateral ptosis and a restrictive infraductive external ophthalmoplegia. We previously demonstrated that CFEOM1 is caused by an autosomal dominant locus on chromosome 12 and results from a developmental absence of the superior division of the oculomotor nerve. We now have mapped a variant of CFEOM, exotropic strabismus fixus ("CFEOM2"). Affected individuals are born with bilateral ptosis and restrictive ophthalmoplegia with the globes "frozen" in extreme abduction. This autosomal recessive disorder is present in members of three consanguineous Saudi Arabian families. Genetic analysis of 70 individuals (20 affected individuals) reveals linkage to markers on chromosome 11q13, with a combined LOD score of 12.3 at the single nonrecombinant marker, D11S1314. The 2.5-cM CFEOM2 critical region is flanked by D11S4196/D11S4162 and D11S4184/1369. Two of the three families share a common disease-associated haplotype, suggesting a founder effect for CFEOM2. We hypothesize that CFEOM2 results from an analogous developmental defect to CFEOM1, one that affects both the superior and inferior divisions of the oculomotor nerve and their corresponding alpha motoneurons and extraocular muscles.  相似文献   
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beta-N-Acetylhexosaminidase was purified from the extract of cabbage by sequential steps of ammonium sulfate fractionation, chromatofocusing, DEAE-Sepharose CL-6B ion exchange chromatography and Sephacryl S-200 HR gel filtration. By these steps, the purity of the enzyme increased by 256 fold with a recovery of 8%. The purified enzyme was homogeneous as examined by native PAGE. It showed an optimal pH of 4, an optimal temperature of 60 degrees C and a Km of 0.94 mM for hydrolysis of pNp-beta-GlcNAc. The molecular mass of the enzyme determined from filtration through Sephacryl S-200 was 150 kDa. Three subunits with molecular mass of 64, 57 and 51 kDa were observed as determined by SDS-PAGE. NBS (0.025 mM), DEPC (3 mM) and WRK (30 mM) significantly inhibited the activity of the enzyme. The enzyme also showed activity toward pNp-beta-GalNAc, N,N'-diacetylchitobiose, N,N',N"-triacetylchitotriose and N,N',N",N"'-tetraacetyl chitotetraose but showed no activity toward pNp-alpha-GlcNAc, chitin and ethylene glycol chitin.  相似文献   
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BACKGROUND: In a retrospective study the efficacy of orthovoltage radiotherapy for refractory painful plantar heel spur was analyzed for 3 different radiation dose concepts. PATIENTS AND METHODS: From 1.1 1984 through 1.3.1994, 182 patients with refractory painful heel symptoms and radiologically proven plantar heel spur received radiotherapy. A total of 141 patients and 170 heels (due to double-sided symptoms) were completely documented in long-term follow-up. Clearly defined semi-quantitative criteria (9-point score) were used to analyze heel pain and ankle function prior to RT, 6 to 12 weeks post-radiation, and at last follow-up. The treatment outcome, i.e. (un)favourable response, of 3 radiation dose concepts were compared: Group A (n = 72 heels) received 12 Gy total radiation dose in 3 fractions per week and 2 series (6 x 1 Gy per series) separated by 6 weeks; group B (n = 98 heels) received 3 Gy total radiation dose in 10 fractions of 0.3 Gy (n = 50) or 5 Gy (10 x 0.5 Gy) (n = 48) with conventional fractionation in 1 series. RESULTS: Radiotherapy was very effective: at last follow-up 67% (group A) and 71% (group B) remained completely free of pain. The rate of "complete pain relief" (i.e. free of any pain symptoms) was not different between the 3 radiation concepts. However, significant differences were observed with regard to "incomplete or insufficient pain relief", i.e. a subjective pain relief of less than 80%, a delayed pain relief after more than 4 weeks or a relapse of pain symptoms in long-term follow-up. More favourable results were achieved in patients receiving 5 Gy or 12 Gy total dose, while patients with 3 Gy total dose had significantly worse results. Prognostic factors for "complete pain relief" were short duration of pain symptoms and acute pain symptoms prior to radiotherapy; with regard to "in-complete or insufficient pain relief" the total dose was found to be a prognostic parameter. CONCLUSIONS: Patients with refractory heel pain can yield a high response to radiotherapy even after failing various conventional treatments previously. Thus, radiotherapy should not be solely regarded as a last resort due to its low costs and high efficacy at low radiation doses.  相似文献   
67.
Since women with a first-degree relative with breast cancer are at increased risk for breast cancer, it is of special importance that they adhere to early detection programs. In this study, women with (389) and without (3295) a family history of breast cancer were compared with respect to risk perception, breast cancer anxiety, and early detection behavior. Special attention was paid to the role of knowing that family history is a breast cancer risk factor. It was found that 46% of "family history positives" did not know that their risk was increased by their family history. Still, family history positives had increased risk perception; our results suggest that this was partly caused by their knowing they belonged to a risk group and partly by their having experienced the disease at close range. Although family history positives had higher risk perceptions, no differences in early detection behavior were found. This could not be attributed to high anxiety levels. Implications for health education are discussed.  相似文献   
68.
Functional programs often combine separate parts using intermediate data structures for communicating results. Programs so defined are modular, easier to understand and maintain, but suffer from inefficiencies due to the generation of those gluing data structures. To eliminate such redundant data structures, some program transformation techniques have been proposed. One such technique is shortcut fusion, and has been studied in the context of both pure and monadic functional programs. In this paper, we study several shortcut fusion extensions, so that, alternatively, circular or higher-order programs are derived. These extensions are also provided for effect-free programs and monadic ones. Our work results in a set of generic calculation rules, that are widely applicable, and whose correctness is formally established.  相似文献   
69.
Virtual Worlds (VW), such as Massive Multiplayer Online Social Games, have been gaining increasing attention in the last few years, mainly due to the new way users interact with them. However, little effort has been devoted to understand their traffic profile and the implications to the traffic management area. With the current growing rate of VWs’ usage, their traffic demand could eventually impose a significant burden on the operation of a typical Internet Service Provider (ISP) network. In this paper, we seek to understand the traffic behavior of an increasingly popular VW application, namely Second Life (SL), from both the connection and network level perspectives. We also show results of a traffic analysis of a SL client, when an avatar performs different actions in the VW, at different places and under different network conditions. Our results show that SL makes intensive use of network resources (mostly bandwidth), since the capacity needed for having a full SL experience (listening to live music) may reach 500 kbps. We then extend the traffic analysis work on SL by providing analytical models for its traffic profile. We aim at helping the network management and planning area to estimate the impact of an intense use of such VW on access links or core networks. Such synthetic models are also useful to the networking research community for the use in network simulations.  相似文献   
70.
ABSTRACT

Gestural interaction devices emerged and originated various studies on multimodal human–computer interaction to improve user experience (UX). However, there is a knowledge gap regarding the use of these devices to enhance learning. We present an exploratory study which analysed the UX with a multimodal immersive videogame prototype, based on a Portuguese historical/cultural episode. Evaluation tests took place in high school environments and public videogaming events. Two users would be present simultaneously in the same virtual reality (VR) environment: one as the helmsman aboard Vasco da Gama’s fifteenth-century Portuguese ship and the other as the mythical Adamastor stone giant at the Cape of Good Hope. The helmsman player wore a VR headset to explore the environment, whereas the giant player used body motion to control the giant, and observed results on a screen, with no headset. This allowed a preliminary characterisation of UX, identifying challenges and potential use of these devices in multi-user virtual learning contexts. We also discuss the combined use of such devices, towards future development of similar systems, and its implications on learning improvement through multimodal human–computer interaction.  相似文献   
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