Rating and ranking of multiple-aspect alternatives using fuzzy sets

A method is proposed to deal with multiple-alternative decision problems under uncertainty. It is assumed that all the alternatives in the choice set can be characterized by a number of aspects, and that information is available to assign weights to these aspects and to construct a rating scheme for the various aspects of each alternative. The method basically consists of computing weighted final ratings for each alternative and comparing the weighted final ratings. The uncertainty that is assumed to be inherent in the assessments of the ratings and weights is accounted for by considering each of these variables as fuzzy quantities, characterized by appropriate membership functions. Accordingly, the final evaluation of the alternatives consists of a degree of membership in the fuzzy set of alternatives ranking first. A practical method is given to compute membership functions of fuzzy sets induced by mappings, and applied to the problem at hand. A number of examples are worked out. The method is compared to another one proposed by Kahne who approaches the problem probabilistically

Electronic Transport Properties of Pentacene Single Crystals upon Exposure to Air

We report the effect of air exposure on the electronic properties of pentacene single crystals. Air can diffuse reversibly in and out of the crystals and controls the physical properties. We discern two competing mechanisms that modulate the electronic transport. The presence of oxygen increases the hole conduction, as in dark four O2 molecules introduce one charge carrier. This effect is enhanced by the presence of visible light. Contrarily, water, present in ambient air, is incorporated in the crystal lattice and forms trapping sites for injected charges.Comment: 16 pages, 3 figure

Cerebral Venous Thrombosis and Hyperthyroidism

Cerebral venous thrombosis (CVT) is mostly caused by pro-thrombotic factors. Hyperthyroidism is not a wellknown risk factor. We present a case report on a 17 year old girl who developed life-threatening CVT after Graves’ disease. A review of the literature reveals further 34 cases of CVT and hyperthyroidism. Abnormalities in the coagulation system leading to hypercoagulability such as increased coagulation factors are detected in patients with hyperthyroidism, and these abnormalities seem to be thyroxin-dependent. The cause of CVT may be multi-factorial. Our patient used oral hormonal contraception without complications until the development of severe Graves’ disease. Hyperthyroidism is suspected as the main precipitating cause of CVT in this case. We recommend performing MRI with venous angiography when a hyperthyroid patient presents with unusual headache alone or in combination with other neurological symptoms. If CVT is proven, blood screening for coagulation abnormalities should be performed. On the other hand, diagnostics for finding the cause of CVT should include blood tests of thyroid function. Early treatment of CVT and hyperthyroidism is mandatory.publishedVersio

Glioma-associated epilepsy : and the treatment with antiepileptic drugs

Background: Gliomas are primary brain tumors with a risk of epileptic seizures that especially depends on subtype. Whether epilepsy or anti-epileptic drugs (AEDs) prolong survival in patients with glioblastoma (GBM) is a matter of debate. Studies of psychiatric drug treatment after a glioma diagnosis are sparse. Previous reports on status epilepticus (SE) secondary to glioma were retrospective or included heterogeneous tumor types. Objectives: Firstly, we hypothesized that epilepsy is not favorable for the prognosis of GBM but that particular AEDs can improve the overall survival (OS). Secondly, we hypothesized that AED exposure can be associated with drug-treated anxiety or depression and that use of psychiatric medication differ between glioma patients and the general population. Thirdly, we hypothesized that SE secondary to glioma is related to tumor grade, and that the treatment response and outcome is worse with underlying tumor progression. Material and methods: Data from the Cancer registry of Norway on patients diagnosed with grade II-IV glioma 2004-2010 were linked with the Norwegian Prescription Database and the Norwegian Cause of Death Registry, with a follow-up until 2013. In paper I, we investigated OS in GBM related to AED exposure. In paper II, we examined risk factors for drug-treated anxiety and depression after a diagnosis of grade II-IV glioma. In paper III, we described clinical aspects of SE secondary to grade II-IV glioma diagnosed in two Norwegian Western counties. Results and conclusions: Neither epilepsy nor the six most commonly used AEDs in our GBM cohort were proven to affect OS. Exposure to levetiracetam was associated with drug-treated anxiety after a grade II-III glioma diagnosis. Fewer received antidepressants among the patients with grade II-III glioma and epilepsy than among the general population. SE was more frequent with higher tumor grade. Patients with tumor progression responded as well to standard SE treatment as patients with no underlying tumor progression, but had a worse outcome