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101.
Objectives:To assess the diagnostic accuracy of two smartphone cephalometric analysis apps compared with Viewbox software.Materials and Methods:Pretreatment digital lateral cephalograms of 50 consecutive orthodontic patients (20 males, 30 females; mean age, 19.1 years; SD, 11.7) were traced twice using two apps (ie, CephNinja and OneCeph), with Viewbox used as the gold standard computer software program. Seven angular and two linear measurements, originally derived from Steiner cephalometric analysis, were performed.Results:Regarding validity, intraclass correlation coefficients (ICCs) ranged from .903–.983 and .786–.978 for OneCeph vs Viewbox and CephNinja vs Viewbox, respectively. The ICC values for intratool reliability ranged from .647–.993. None of the CephNinja measurements was below the recommended cutoff values of ICCs for reliability.Conclusions:OneCeph has a high validity compared with Viewbox, while CephNinja is the best alternative to Viewbox regarding reliability. Smartphone apps may have a great potential in supplementing traditional cephalometric analysis.  相似文献   
102.
In normoxic hearts a limited number of multilamellar vesicles was found in both endothelial cells and myocytes. The total number of multilamellar vesicles observed in myocytes, particularly those extruded from mitochondria, significantly increased in hearts rendered ischemic for at least 60 mins. The number of multilamellar vesicles extruded from sarcolemma was increased in hearts reperfused after this period of ischemia. The number of multilamellar vesicles in or adjacent to lipid droplets was independent of the duration of ischemia. Multilamellar vesicles were similar in size and periodicity of the lamellae. It is proposed that the number of multilamellar vesicles can be used to quantitate ischemic membrane injury. The formation of multilamellar vesicles was significantly related in time to (a) the accumulation of arachidonic acid and total fatty acids; (b) a decrease in the tissue content of ATP and (c) the release of lactate dehydrogenase (LDH). No significant alterations in the total tissue content of triacylglycerols and phospholipids were detected. The amount of arachidonic acid accumulated in the hearts reflects the degradation of only a minor fraction of the phospholipid pool. Assuming a close relationship between phospholipid degradation, induction of multilamellar vesicles and loss of cellular integrity, the present findings might indicate that the loss of a small part of phospholipids might have serious pathophysiological consequences, as indicated by the morphological changes in cellular membranes and the release of cytoplasmic macromolecules.  相似文献   
103.

Purpose  

The aim of this study is to report on a collective of 20 children from Belarus who had developed papillary thyroid carcinoma with pulmonary metastases after the Chernobyl disaster. In all children fractionated radioiodine therapy (RIT) was ceased before achieving complete remission due to a lack of further effects of 131I therapy and an increased risk of pulmonary fibrosis.  相似文献   
104.

Background

This treatment planning study analyzes dose coverage and dose to organs at risk (OAR) in intensity-modulated radiotherapy (IMRT) of rectal cancer and compares prone vs. supine positioning as well as the effect of dose optimization for the small bowel (SB) by additional dose constraints in the inverse planning process.

Patients and methods

Based on the CT datasets of ten male patients in both prone and supine position, a total of four different IMRT plans were created for each patient. OAR were defined as the SB, bladder, and femoral heads. In half of the plans, two additional SB cost functions were used in the inverse planning process.

Results

There was a statistically significant dose reduction for the SB in prone position of up to 41% in the high and intermediate dose region, compared with the supine position. Furthermore, the femoral heads showed a significant dose reduction in prone position in the low dose region. Regarding the additional active SB constraints, the dose in the high dose region of the SB was significantly reduced by up to 14% with the additional cost functions. There were no significant differences in the dose distribution of the planning target volume (PTV) and the bladder.

Conclusion

Prone positioning can significantly reduce dose to the SB in IMRT for rectal cancer and therefore should not only be used in 3D conformal radiotherapy but also in IMRT of rectal cancer. Further protection of the SB can be achieved by additional dose constraints in inverse planning without jeopardizing the homogeneity of the PTV.
  相似文献   
105.

Purpose

The Taylor Spatial Frame (TSF) is used to correct orthopedic conditions such as correction osteotomies in delayed fracture healing and pseudarthrosis. Long-term TSF-treatments are common and may lead to complications. Current conventional radiological methods are often unsatisfactory for therapy monitoring. Hence, an imaging technique capable of quantifying bone healing progression would be advantageous.

Methods

A cohort of 24 patients with different orthopedic conditions, pseudarthrosis (n?=?10), deformities subjected to correction osteotomy (n?=?9), and fracture (n?=?5) underwent dynamic [18F]-fluoride (Na18F) PET/CT at 8 weeks and 4 months, respectively, after application of a TSF. Parametric images, corresponding to the net transport rate of [18F]-fluoride from plasma to bone, K i were calculated. The ratio of the maximum K i at PET scan 2 and 1 (\( {\overline{K}}_{i, \max } \)) as well as the ratio of the maximum Standard Uptake Value at PET scan 2 and 1 (\( {\overline{SUV}}_{\max } \)) were calculated for each individual. Different treatment end-points were scored, and the overall treatment outcome score was compared with the osteoblastic activity progression as scored with \( {\overline{K}}_{i, \max } \) or \( {\overline{SUV}}_{\max } \).

Results

\( {\overline{K}}_{i, \max } \) and \( {\overline{SUV}}_{\max } \) were not correlated within each orthopedic group (p?>?0.1 for all groups), nor for the pooled population (p?=?0.12). The distribution of \( {\overline{K}}_{i, \max } \) was found significantly different among the different orthopedic groups (p?=?0.0046) -also for \( {\overline{SUV}}_{\max } \) (p?=?0.022). The positive and negative treatment predictive values for \( {\overline{K}}_{i, \max } \) were 66.7 % and 77.8 %, respectively. Corresponding values for \( {\overline{SUV}}_{\max } \) were 25 % and 33.3 %

Conclusions

The \( {\overline{K}}_{i, \max } \) obtained from dynamic [18F]-fluoride-PET imaging is a promising predictive factor to evaluate changes in bone healing in response to TSF treatment.
  相似文献   
106.
FMRI research in Alzheimer's disease (AD) and mild cognitive impairment (MCI) typically is aimed at determining regional changes in brain function, most commonly by creating a model of the expected BOLD-response and estimating its magnitude using a general linear model (GLM) analysis. This crucially depends on the suitability of the temporal assumptions of the model and on assumptions about normality of group distributions. Exploratory data analysis techniques such as independent component analysis (ICA) do not depend on these assumptions and are able to detect unknown, yet structured spatiotemporal processes in neuroimaging data. Tensorial probabilistic ICA (T-PICA) is a model free technique that can be used for analyzing multiple subjects and groups, extracting signals of interest (components) in the spatial, temporal, and also subject domain of FMRI data. We applied T-PICA and model-based GLM to study FMRI signal during face encoding in 18 AD, 28 MCI patients, and 41 healthy elderly controls. T-PICA showed activation in regions associated with motor, visual, and cognitive processing, and deactivation in the default mode network. Six networks showed a significantly decreased response in patients. For two networks the T-PICA technique was significantly more sensitive to detect group differences than the standard model-based technique. We conclude that T-PICA is a promising tool to identify and detect differences in (de)activated brain networks in elderly controls and dementia patients. The technique is more sensitive than the commonly applied model-based method. Consistent with other research, we show that networks of activation and deactivation show decreased reactivity in dementia.  相似文献   
107.
In previous functional magnetic resonance imaging (fMRI) studies concerning romantic love, several brain regions including the caudate and putamen have consistently been found to be more responsive to beloved‐related than control stimuli. In those studies, infatuated individuals were typically instructed to passively view the stimuli or to think of the viewed person. In the current study, we examined how the instruction to attend to, or ignore the beloved modulates the response of these brain areas. Infatuated individuals performed an oddball task in which pictures of their beloved and friend served as targets and distractors. The dorsal striatum showed greater activation for the beloved than friend, but only when they were targets. The dorsal striatum actually tended to show less activation for the beloved than the friend when they were distractors. The longer the love and relationship duration, the smaller the response of the dorsal striatum to beloved‐distractor stimuli was. We interpret our findings in terms of reinforcement learning. By virtue of using a cognitive task with a full factorial design, we show that the dorsal striatum is not activated by beloved‐related information per se, but only by beloved‐related information that is attended. Hum Brain Mapp 35:503–512, 2014. © 2012 Wiley Periodicals, Inc.  相似文献   
108.

Background

Primary ventral hernia is a common condition. Surgical repair is associated with complications, but no clear predictive risk factors have been identified. The European Hernia Society classification offers a structured framework to describe hernias and to analyze postoperative complications. Given this structured nature, the European Hernia Society classification might prove useful for preoperative patient or treatment classification. The objective of this study was to investigate the European Hernia Society classification as a predictor for complications within 30 days after primary ventral hernia surgery.

Methods

A registry-based, prospective cohort study was performed, including all patients undergoing primary ventral hernia surgery between September 1, 2011 and February 29, 2016. Univariate analyses and multivariable logistic regression analysis were performed to identify risk factors for postoperative complications.

Results

A total of 2,374 patients were included, of whom 105 (4.4%) patients had ≥1 complications, either a wound, surgical, or medical complication. Factors associated with complications in univariate analyses (P?<?.10) and clinically relevant factors were included into the multivariable analyses. In the multivariable analyses, age, body mass index, and the duration of the operation were independent risk factors. The diameter of the hernia was not an independent risk factor.

Conclusion

Primary ventral hernia repair is associated with a 4.4% rate of complications. No correlation was found between the European Hernia Society classification and postoperative complications. Age, body mass index, and duration of the operation were correlated with postoperative complications. Therefore, age and body mass index should be used in the preoperative risk assessment.  相似文献   
109.
110.
This experimental study aimed to determine the effect of practicing a position matching task with (mirror) visual feedback of the less-impaired arm on the matching accuracy of the impaired arm in children and adolescents with spastic hemiparetic cerebral palsy. Practice consisted of 40 trials of bimanual target matching, where one group received regular visual feedback and a second group received mirror visual feedback of the less-impaired arm. On three occasions (pre, post, and after a 1-week-retention) position sense (matching accuracy measured as the endpoint error in cm) of the impaired arm was tested with a unimanual and bimanual matching task, performed without any visual information of either hand. Matching accuracy of the impaired arm was better in the post-test than in the pre-test, but this improvement was similar for both practice groups. In the retention-test, accuracy had returned to pre-test-level, which might be ascribed to the short duration of the practice period. These outcomes suggest that practicing a matching task with visual feedback of the less-impaired arm might help to improve the matching accuracy of the impaired arm in individuals with spastic hemiparetic cerebral palsy.  相似文献   
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