2,980 research outputs found
Ruptured lenticulostriate artery aneurysm: a report of a case treated with endovascular embolisation.
A 65-year-old woman presented to the emergency department with sudden onset of left-sided weakness, headache and vomiting. A cerebral CT showed an acute intracerebral haemorrhage involving the right caudate nucleus and lentiform nucleus with mild midline shift and intraventricular extension. CT angiography did not reveal aneurysm or other vascular anomaly. Conventional cerebral angiography demonstrated a 3 mm right medial lenticulostriate branch aneurysm, arising from the right anterior cerebral artery (ACA). Endovascular treatment was performed from the left internal carotid via the anterior communicating artery into the right ACA. Complete occlusion was achieved with injection of N-butyl-2-cyanoacrylate. The patient had neurological rehabilitation during hospitalisation followed by outpatient physical therapy. Two years later, clinical follow-up demonstrated excellent recovery
Radiation dose to the operator during fluoroscopically guided spine procedures
Purpose: Fluoroscopy is widely used to guide diagnostic and therapeutic spine procedures. The purpose of this study was to quantify radiation incident on the operator (operator Air Kerma) during a wide range of fluoroscopy-guided spine procedures and its correlation with the amount of radiation incident on the patient (Kerma Area ProductâKAP). Methods: We retrospectively included 57 consecutive fluoroscopically guided spine procedures. KAP [Gy cm2] and total fluoroscopy time were recorded for each procedure. An electronic dosimeter recorded the operator Air Kerma [Î1⁄4Gy] for each procedure. Operator Air Kerma for each procedure, correlation between KAP and operator Air Kerma, and between KAP and fluoroscopy time was obtained. Results: Operator Air Kerma was widely variable across procedures, with median value of 6.4 Î1⁄4Gy per procedure. Median fluoroscopy time and median KAP per procedure were 2.6 min and 4.7 Gy cm2, respectively. There was correlation between operator Air Kerma and KAP (r2 = 0.60), with a slope of 1.6 Î1⁄4Gy Air Kerma per unit Gy cm2KAP incident on the patient and between fluoroscopy time and KAP (r2 = 0.63). Conclusion: Operator Air Kerma during individual fluoroscopy-guided spine procedures can be approximated from the commonly and readily available information of the total amount of radiation incident on the patient, measured as KAP
Operator radiation doses during CT-guided spine procedures
Objectives: To perform a pilot study to quantify the radiation dose incident on operators during CT-guided interventional spine procedures, and provide a quick method to approximate it based on the total amount of radiation reported by the CT scanner. Patients and Methods: Data retrospectively obtained from 26 consecutive CT-guided spine procedures, encompassing a variety of interventions. Intermittent low-dose limited-coverage CT-scanning performed using a “step and shoot” mode to visualize needle advancement. The operator wore an electronic direct dosimeter to record the dose measured above the operator's lead apron [μGy] for each procedure. Total amount of radiation used for CT-guidance quantified by the Dose-Length Product (DLP) [mGy-cm] provided by the CT scanner. The relationship between the operator's dose and the DLP was assessed. Results: Average and median operator's dose were 2.3 and 1.9 μGy, respectively, with half of these values ranging between 0.7 and 2.5 μGy. Average and median DLP values used to perform the CT-guided procedure were 58 and 54 mGy-cm respectively, and half of these values ranged between 38 and 68 mGy-cm. There was a statistically significant correlation between the operator's dose and the DLP used to perform CT-guidance (r = 0.61), with an operator's dose-DLP conversion factor of 0.04 μGy / 1 mGy-cm (range: 0.006-0.083 μGy / 1 mGy-cm). Conclusions: In our series, the average amount of radiation used during CT guided procedures was about 50 mGy-cm (DLP), and the corresponding average operator's dose was about 2 μGy. We showed how an approximate estimate of the operator's dose could be obtained right after each procedure, based on the CT-scanner DLP output
An assessment of the impact of possible CAP reform scenarios on Romanian agriculture
Using a simplified model, with key-variable the prices of two different possible scenarios of CAP reform after 2013 (moderate and radical), this paper present a comparison between the price effects of implementation of each reform scenario at 2015 horizon on Romanian agriculture. This short analysis shows that, under the presented hypotheses, the net welfare effect, due to the price changes, for the selected products, is positive in both reform scenarios, yet greater in the case of the radical reform. Integrated in the large context of Romanian development, it seems that the influence of CAP reform upon agriculture and rural areas will be most likely a gradual one: an interpenetration between the two scenarios is foreseeable, starting with the moderate reform that will dominate the period around 2013, the reform measures acquiring a more radical character afterwards.CAP reform, Romania, welfare effects, Agricultural and Food Policy,
Rich, Sturmian, and trapezoidal words
In this paper we explore various interconnections between rich words, Sturmian words, and trapezoidal words. Rich words, first introduced by the second and third authors together with J. Justin and S. Widmer, constitute a new class of finite and infinite words characterized by having the maximal number of palindromic factors. Every finite Sturmian word is rich, but not conversely. Trapezoidal words were first introduced by the first author in studying the behavior of the subword complexity of finite Sturmian words. Unfortunately this property does not characterize finite Sturmian words. In this note we show that the only trapezoidal palindromes are Sturmian. More generally we show that Sturmian palindromes can be characterized either in terms of their subword complexity (the trapezoidal property) or in terms of their palindromic complexity. We also obtain a similar characterization of rich palindromes in terms of a relation between palindromic complexity and subword complexity
Thrombectomy of calcified emboli in stroke. Does histology of thrombi influence the effectiveness of thrombectomy?
BACKGROUND AND PURPOSE
Thrombus composition has been postulated to affect the success of endovascular therapy. Calcified clots are composed of large amounts of calcium phosphate which influences their mechanical properties and may serve as a model for testing this hypothesis. The aim of this study was to evaluate the recanalization and complication rates of calcified thromboemboli in patients with acute ischemic stroke who underwent thrombectomy.
MATERIAL AND METHODS
A retrospective analysis was performed of all calcified intracranial thromboemboli in patients suffering an acute ischemic stroke, referred for endovascular therapy at two centers between January 2013 and July 2016.
RESULTS
Eight patients with a calcified intracranial clot underwent stent retriever thrombectomy (five women; mean age 80 years). Mean clot attenuation was 305 HU (range 150-640 HU). Successful reperfusion defined, as Thrombolysis in Cerebral Infarction grade 2b-3 was achieved in only one patient (12.5%). Two periprocedural adverse events occurred: one peripheral vessel perforation which was coiled and one inadvertent stent retriever detachment due to fracture of the stent retriever wire.
CONCLUSION
Stent retriever thrombectomy of calcified thromboemboli seems less effective than with other types of clots. Different mechanical properties of calcified clots may render them stiffer and less accessible for stent retrievers. When faced with a calcified intracranial thromboembolus in clinical practice, a more contained approach may be warranted in view of low recanalization rates, and the potential for periprocedural adverse events
Characterization Results for the Poset Based Representation of Topological Relations - I: Introduction and Models
@article{DBLP:journals/informaticaSI/ForlizziN99,
author = {Luca Forlizzi and
Enrico Nardelli},
title = {Characterization Results for the Poset Based Representation
of Topological Relations - I: Introduction and Models.},
journal = {Informatica (Slovenia)},
volume = {23},
number = {2},
year = {1999},
bibsource = {DBLP, http://dblp.uni-trier.de}
Breaking sickles for shaping money. Testing the accuracy of weight-based fragmentation
Bronze is considered a key commodity during the European Bronze Age (BA, 2200-800BC). Recent studies have shown that, mostly during the Late Bronze Age (Late BA, 1300–800 BC), fragmented bronze objects were subjected to regulation consistent with a Pan-European weight system. This hypothesis is mostly based on statistical analyses of weights. In this article, we present the results of an experiment in which sickle replicas were broken up and the resulting fragments weighed and compared with examples attested from the BA. The purpose of the fragmentation was to obtain pieces complying with certain weight patterns similar to regularities observed in archaeological fragmented sickles and fragmented objects in general. Results of the fragmentation experiment have been compared with a statistical analysis of c. 1500 fragmented sickles from European BA hoards, concluding that archaeological and replica fragments share the same metrological characteristics. We suggest that rough weight-regulated fragmentation is possible even by persons with no metallurgical skill, and that both inaccurate and ‘unwanted’ fragments probably comprise the known archaeological examples, The article demonstrates that statistical analyses usually employed in similar research allow for detecting the existence of weight systems even in a dataset characterized by the significant presence of random values
Characterization Results for the Poset Based Representation of Topological Relations - II: Intersection and Union
@article{DBLP:journals/informaticaSI/ForlizziN00,
author = {Luca Forlizzi and
Enrico Nardelli},
title = {Characterization Results for the Poset Based Representation
of Topological Relations - II: Intersection and Union.},
journal = {Informatica (Slovenia)},
volume = {24},
number = {1},
year = {2000},
bibsource = {DBLP, http://dblp.uni-trier.de}
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