118 research outputs found

    Meningioma

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    Meningiomas represent the most common primary brain tumor and comprise 3 World Health Organization (WHO) grades, the most frequent being WHO grade I (90%). Surgery is mandatory to establish the diagnosis and to remove the tumor; however, complete resection can be achieved in only <50% of patients. Depending on the extent of resection, tumor location and the WHO grade radiation therapy can be applied. The issue of systemic treatment such as chemotherapy or targeted therapy (eg, somatostatin receptors, antiangiogenic agents) is yet not solved, particularly as current data are derived from small uncontrolled series in patients with long-standing disease and after several pretreatments. A more thorough understanding of molecular genetics, signaling pathways and prognostic factors in meningiomas should lead to the design of studies which stratify according to these factors. These studies have to be conducted in newly diagnosed patients after incomplete resection and in tumors of WHO grade II and II

    English to Persian Translation Accuracy of “Rules and Regulations” of International Banking System

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    This study comparatively analyzed the English to Persian translations of “rules and regulations” of the international banking system, at lexicon, phrase, sentence and paragraph levels to find out if the translations had been semantically comparable to their English versions. The translated texts, together with their English scource texts, were handed in to raters to assess and score semantically based on a three-point scale of “incorrect”, “fair” and “correct”. According to the results, the majority (96%) of lexicons had been translated correctly into Persian, while a small percentage of translated lexicons (3%) had a fair quality and an even smaller percentage (1%) were incorrectly translated. As for the phrases, most of them (86%) had been translated correctly into Persian, while a small percentage of translated phrases (8%) had a fair quality and an even smaller percentage (6%) had been incorrectly translated. Regarding sentences, 44% of their translations had a good and 44% had fair quality, whereas some smaller numbers (12%) had been incorrectly translated. Compared to previous components, i.e. lexicon and phrases, the percentage of incorrect translations had noticeably increased at the level of sentence. Yet, the mean words in Persian sentences (i.e., 23.48) were rather similar to the source language sentences (i.e., 25.72). Regarding paragraphs, 40% of the translations had a good and 40% had a fair quality, but a significant number (20%) had incorrect translations. So, unlike the lexicons and phrases, a significant number of sentences and paragraphs had semantically been inaccurately translated. In addition, the mean number of words in Persian paragraphs (64.6) was considerably smaller than the mean words in English paragraphs (71.1). &nbsp; &nbsp; Keywords: Semantic accuracy in translation, English to Persian, Banking rules and regulation

    Elevated level of endothelin-1 in cerebrospinal fluid and lack of nitric oxide in basilar arterial plasma associated with cerebral vasospasm after subarachnoid haemorrhage in rabbits

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    Background: The role of endothelin-1 (ET-1) and nitric oxide (NO) as two important mediators in the development of cerebral vasospasm (CVS) after subarachnoid haemorrhage (SAH) is controversial. The objective of this study was to determine whether local levels of ET-1 and NO in cerebral arterial plasma and/or in cerebrospinal fluid (CSF) are associated with the occurrence of CVS after SAH. Methods: CVS was induced using the one-haemorrhage rabbit model and confirmed by digital subtraction angiography of the rabbits' basilar artery on day 5. Prior to sacrifice, local CSF and basilar arterial plasma samples were obtained by a transclival approach to the basilar artery. Systemic arterial plasma samples were obtained. ET-1 levels were determined by immunometric technique (pg/ml ± SEM) and total nitrate/nitrite level spectrophotometrically (µmol/l ± SEM). Findings: Angiographic CVS was documented after SAH induction (n = 12, P < 0.05). The ET-1 level in CSF was significantly elevated by 27.3% to 0.84 ± 0.08pg/ml in SAH animals (n = 7) in comparison to controls (0.66 ± 0.04pg/ml, n = 7, P < 0.05). There was no significant difference in ET-1 levels in systemic and basilar arterial plasma samples of SAH animals compared to controls. A significant lack of local NO metabolites was documented in basilar arterial plasma after SAH (36.8 ± 3.1µmol/l, n = 6) compared to controls (61.8 ± 6.2µmol/l, n = 6, P < 0.01). Conclusion: This study demonstrates that an elevated ET-1 level in CSF and local lack of NO in the basilar arterial plasma samples are associated with CVS after experimental SA

    Thalassemia major may decrease the frequency of febrile convulsions in children

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    AbstractAim: We aimed to determine the relative frequency of febrile convulsion in children with major thalassemia to theorize that higher serum iron levels could reduce the incidence of febrile convulsion. Background: Febrile convulsion is the most common type of seizure in childhood that its causes are not fully understood. However, some risk factors have been cited such as the serum iron level. Materials and methods: Three hundred and fifty-nine children aged more than 5 years with major thalassemia who were receiving blood were enrolled as the case group. The control group consisted of 357 children without thalassemia aged 4–7 years (151 boys, 206 girls) who were referred to healthcare centers for routine health monitoring. Included data were the history of febrile convulsion, age of onset and type and the frequency of convulsions. Results: Children in control group significantly experienced more febrile convulsions than thalassemic children [4/359 (1.1%) in the thalassemic children and 14/357 (3.9%) in the control group had experienced febrile convulsions (P=0.017)]. Conclusion: The frequency of febrile convulsion in children with major thalassemia is less than that of normal children. Children with thalassemia major may have higher serum levels of iron and such high serum iron levels might have a protective role in the children who have a vulnerability for febrile convulsions

    Risk assessment of occupational exposure to BTEX in the National Oil Distribution Company in Iran

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    BACKGROUND: This study evaluated the quantitative, carcinogenic and non-carcinogenic risk of exposure to BTEX using lifetime cancer risk (LCR) and hazard quotient (HQ) in the National Company for Distribution of Petroleum Products in Iran.METHODS: In this risk assessment method, the data were collected in different parts of the company. In order to determine the concentration of BTEX, sampling was carried out in different parts using activated carbon. A Gas Chromatography–Flame Ionization Detector (GC-FID) was used for analysis. Analysis and sampling was conducted according to the NIOSH 1500 method. For carcinogenic risk assessment, LCR was calculated. For non-carcinogenic risk assessment, HQ was calculated.RESULTS: The carcinogenetic risk of benzene was definite for loading and deep handling units, and safety officer, and was probable rank for sealing, inspection gate, security, loading 1, and deep handling units. The carcinogenic risk of ethylbenzene was definite for quality control and loading 1 units, was probable for deep handling and loading 2 units, and safety officer, and was possible for sealing, inspection gates, security units. The non-carcinogenic risk of toluene was acceptable for deep handling, clothing, inspection gates, and sealing units, but was unacceptable for officer safety, quality control, loading 1, and loading 2 units. The non-carcinogenic risk of xylene was acceptable for the inspection gate unit, but was unacceptable for security, sealing, officer safety, quality control, deep handling, loading 1, loading 2 units.CONCLUSIONS: This risk assessment method used was a comprehensive and quantitative method, so it determined risk accurately. Commensurate with the risk level of each part of the company, the appropriate corrective actions must be carried out

    Intraoperative template-molded bone flap reconstruction for patient-specific cranioplasty

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    Cranioplasty is a common neurosurgical procedure. Free-hand molding of polymethyl methacrylate (PMMA) cement into complex three-dimensional shapes is often time-consuming and may result in disappointing cosmetic outcomes. Computer-assisted patient-specific implants address these disadvantages but are associated with long production times and high costs. In this study, we evaluated the clinical, radiological, and cosmetic outcomes of a time-saving and inexpensive intraoperative method to mold custom-made implants for immediate single-stage or delayed cranioplasty. Data were collected from patients in whom cranioplasty became necessary after removal of bone flaps affected by intracranial infection, tumor invasion, or trauma. A PMMA replica was cast between a negative form of the patient's own bone flap and the original bone flap with exactly the same shape, thickness, and dimensions. Clinical and radiological follow-up was performed 2months post-surgery. Patient satisfaction (Odom criteria) and cosmesis (visual analogue scale for cosmesis) were evaluated 1 to 3years after cranioplasty. Twenty-seven patients underwent intraoperative template-molded patient-specific cranioplasty with PMMA. The indications for cranioplasty included bone flap infection (56%, n = 15), calvarian tumor resection (37%, n = 10), and defect after trauma (7%, n = 2). The mean duration of the molding procedure was 19 ± 7min. Excellent radiological implant alignment was achieved in 94% of the cases. All (n = 23) but one patient rated the cosmetic outcome (mean 1.4years after cranioplasty) as excellent (70%, n = 16) or good (26%, n = 6). Intraoperative cast-molded reconstructive cranioplasty is a feasible, accurate, fast, and cost-efficient technique that results in excellent cosmetic outcomes, even with large and complex skull defect

    Drilling Performance Monitoring and Optimization: A Data-driven Approach

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    Abstract Drilling performance monitoring and optimization are crucial in increasing the overall NPV of an oil and gas project. Even after rigorous planning, drilling phase of any project can be hindered by unanticipated problems, such as bit balling. The objective of this paper is to implement artifcial intelligence technique to develop a smart model for more accurate and robust real-time drilling performance monitoring and optimization. For this purpose, the back propagation, feed forward neural network model was developed to predict rate of penetration (ROP) using diferent input parameters such as weight on bit, rotations per minute, mud fow (GPM) and diferential pressures. The heavy hitter features identifcation and dimensionality reduction are performed to understand the impacts of each of the drilling parameters on ROP. This will be used to optimize the input parameters for model development and validation and performing the operation optimization when bit is underperforming. The model is frst developed based on the drilling experiments performed in the laboratory and then extended to feld applications. From both laboratory and feld test data provided, we have proved that the data-driven model built using multilayer perceptron technique can be successfully used for drilling performance monitoring and optimization, especially identifying the bit malfunction or failure, i.e., bit balling. We have shown that the ROP has complex relationship with other drilling variables which cannot be captured using conventional statistical approaches or from diferent empirical models. The data-driven approach combined with statistical regression analysis provides better understanding of relationship between variables and prediction of ROP

    Application of liquid-liquid microextraction based on deep eutectic solvent for preconcentration and spectrophotometric determination of purpurin

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    This research used a simple and efficient liquid-phase microextraction method based on deep eutectic solvents for preconcentration and spectrophotometric determination of purpurin (1, 2, and 4-trihydroxyanthraquinone) dye. The choline chloride-acetic acid DES with a molar ratio of 1:2 was synthesized and used with 1-Decanol as the extraction solvent. The influence of effective parameters on the extraction efficiency, including the type and volume of extracting solvents, pH of sample solution, the molar ratio of DES components, and sodium chloride salt concentration were studied, using the response surface method. The highest extraction percentage (>95%) was obtained at pH = 5.5, 550 mg/L of sodium chloride, 350 and 500 µL of DES, and 1-Decanol solvents, respectively. The effect of different ions and dyes on the extraction efficiency was examined and the results indicated that the method has an acceptable selectivity. The present process was linear in the concentration range of 5.0×10-7 to 2.0×10-5 mol/L of purpurine, with a detection limit of 2.7×10-7 mol/L, preconcentration factor of 100, and a relative standard deviation of 3.13%. Finally, to test the applicability of the proposed method, it was investigated for the uptake of purpurin from various water samples, successfully

    Intraoperative Visualization of Bilateral Thrombosis in the Posterior Inferior Cerebellar Artery Apparent in the Telovelomedullary Segment

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    Unilateral posterior inferior cerebellar artery (PICA) thrombosis is frequent. However, bilateral PICA thrombosis is rare. Herein we report about an intraoperative visualization of a bilateral thrombosis of the telovelomedullary segment of the PICA. A 74-year-old woman was admitted to our department on day two of a bilateral PICA thrombosis with developing cerebellar infarction. Her Glasgow Coma Scale score dropped from 15 to 13, and cranial computed tomography revealed compression of the fourth ventricle with consecutive occlusive hydrocephalus. After the insertion of an external ventricular drainage, the patient underwent urgent suboccipital decompressive craniectomy with removal of infarcted cerebellar tonsils, which allowed the bilateral visualization of the thrombosed telovelomedullary segments. The surgical access may offer surgical therapeutic options in a hyperacute occlusion, such as thromb-/embolectomy or bypass procedures

    Norepinephrine-induced hypertension dilates vasospastic basilar artery after subarachnoid haemorrhage in rabbits

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    Background: Vasopressor-induced hypertension is routinely indicated for prevention and treatment of cerebral vasospasm (CVS) after subarachnoid haemorrhage (SAH). Mechanisms underlying patients' clinical improvement during vasopressor-induced hypertension remain incompletely understood. The aim of this study was to evaluate angiographic effects of normovolaemic Norepinephrine (NE)-induced hypertension therapy on the rabbit basilar artery (BA) after SAH. Methods: Cerebral vasospasm was induced using the one-haemorrhage rabbit model; sham-operated animals served as controls. Five days later the animals underwent follow-up angiography prior to and during NE-induced hypertension. Changes in diameter of the BA were digitally calculated in mean µm ± SEM (standard error of mean). Findings: Significant CVS of 14.2% was documented in the BA of the SAH animals on day 5 compared to the baseline angiogram on day 0 (n = 12, p  0.05). During systemic administration of NE, mean arterial pressure increased from 70.0 ± 1.9mmHg to 136.0 ± 2.1mmHg in the SAH group (n = 12, p < 0.001) and from 72.0 ± 3.1 to 137.8 ± 1.3 in the control group (n = 12, p < 0.001). On day 5 after SAH, a significant dilatation of the BA in response to norepinephrine could be demonstrated in both groups. The diameter of the BA in the SAH group increased from 640.5 ± 17.5 µm to 722.5 ± 23.7 µm (n = 12, p < 0.05; ). In the control group the diameter increased from 716.8 ± 15.5 µm to 779.9 ± 24.1 µm (n = 12, p < 0.05). Conclusion: This study demonstrated that NE-induced hypertension causes angiographic dilatation of the BA in the SAH rabbit model. Based on these observations, it can be hypothesised that clinical improvement during vasopressor-induced hypertension therapy after SAH might be explained with cerebral vasodilatation mechanisms that lead to improvement of cerebral blood flo
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