57 research outputs found

    Non-Hermitian Delocalization and Eigenfunctions

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    Recent literature on delocalization in non-Hermitian systems has stressed criteria based on sensitivity of eigenvalues to boundary conditions and the existence of a non-zero current. We emphasize here that delocalization also shows up clearly in eigenfunctions, provided one studies the product of left- and right-eigenfunctions, as required on physical grounds, and not simply the squared modulii of the eigenfunctions themselves. We also discuss the right- and left-eigenfunctions of the ground state in the delocalized regime and suggest that the behavior of these functions, when considered separately, may be viewed as ``intermediate'' between localized and delocalized.Comment: 8 pages, 11 figures include

    Razvoj i vrednovanje lako topljivih tableta kompleksa meloksikama s β-ciklodekstrinom pripravljenih izravnom kompresijom

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    The aim of this study was to prepare fast-dissolving tablets of meloxicam after its complexation with β-cyclodextrin (β-CD) and to investigate the effect of using different superdisintegrants on the disintegration and release of meloxicam from the tablets. A complex of meloxicam with β-CD was prepared by spray drying and then compressed in the form of tablets utilizing the direct compression technique. Three superdisintegrants were employed at various levels sodium starch glycolate, croscarmellose sodium, and crospovidone. Co-spray dried micro-crystalline cellulose and mannitol (Avicel HFE-102) were used as diluents in the tablets. Prior to compression, the pre-compression parameters showed satisfactory flow properties. Post-compression parameters showed that all tablet formulations had acceptable mechanical properties. Wetting and disintegration times were prolonged by increasing the level of sodium starch glycolate in the tablets. This was attributed to the formation of a viscous gel layer around the tablets by sodium starch glycolate whereas this effect was not observed with croscarmellose sodium and crospovidone. Dissolution studies showed fast release of meloxicam except in tablets containing a high level of sodium starch glycolate. Complexation of meloxicam with β-CD significantly improved the solubility of the drug and improved the mechanical properties of tablets produced by direct compression.Cilj rada bio je priprava lako topljivih tableta kompleksa meloksikama s β-ciklodekstrinom (β-CD) te ispitati utjecaj različitih superdezintegratora na raspadljivost tableta i oslobađanje meloksikama. Kompleks meloksikama s β-CD pripravljen je metodom sušenja sprejem, a komprimiran je u tablete metodom izravne kompresije. U pripravi tableta korištene su tri različite količine triju superdezintegratora: natrijev škrobni glikolat, natrijeva sol kroskarmeloze i krospovidon, dok su mikrokristalinična celuloza i manitol (Avicel HFE-102) upotrijebljeni kao punila. Predkompresijski parametri ukazivali su na zadovoljavajuću tečnost. Postkompresijski parametri pokazali su da sve tablete imaju prihvatljiva mehanička svojstva. Vlaženje i vrijeme raspadanja bilo je produljeno kada se povećao udio natrijevog škrobnog glikolata u tabletama. To je pripisano stvaranju viskoznog sloja gela oko tableta, što nije primijećeno u pripravi tableta s natrijevom soli kroskarmeloze i krospovidonom. Oslobađanje meloksikama bilo je brzo iz svih tableta, osim iz tableta s visokim udjelom natrijeve soli škrobnog glikolata. Kompleksiranje meloksikama s β-CD značajno je povećalo topljivost lijeka i poboljšalo mehanička svojstva tableta

    Vortex Flow and Transverse Flux Screening at the Bose Glass Transition

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    We investigate the vortex phase diagram in untwinned YBaCuO single crystals with columnar defects. These randomly distributed defects, produced by heavy ion irradiation, are expected to induce a ``Bose Glass'' phase of localized vortices characterized by a vanishing resistance and a Meissner effect for magnetic fields transverse to the defect axis. We directly observe the transverse Meissner effect using an array of Hall probe magnetometers. As predicted, the Meissner state breaks down at temperatures Ts that decrease linearly with increasing transverse magnetic field. However, Ts falls well below the conventional melting temperature Tm determined by a vanishing resistivity, suggesting an intermediate regime where flux lines are effectively localized even when rotated off the columnar defects.Comment: 15 pages, 5 figure

    Apocrine Hidradenocarcinoma of the Scalp: A Classification Conundrum

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    Introduction The classification of malignant sweat gland lesions is complex. Traditionally, cutaneous sweat gland tumors have been classified by either eccrine or apocrine features. Methods A case report of a 33-year-old Hispanic man with a left scalp mass diagnosed as a malignancy of adnexal origin preoperatively is discussed. After presentation at our multidisciplinary tumor board, excision with ipsilateral neck dissection was undertaken. Results Final pathology revealed an apocrine hidradenocarcinoma. The classification and behavior of this entity are discussed in this report. Conclusion Apocrine hidradenocarcinoma can be viewed as an aggressive malignant lesion of cutaneous sweat glands on a spectrum that involves both eccrine and apoeccrine lesions

    TRPA1 Contributes to the Acute Inflammatory Response and Mediates Carrageenan-Induced Paw Edema in the Mouse

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    Transient receptor potential ankyrin 1 (TRPA1) is an ion channel involved in thermosensation and nociception. TRPA1 is activated by exogenous irritants and also by oxidants formed in inflammatory reactions. However, our understanding of its role in inflammation is limited. Here, we tested the hypothesis that TRPA1 is involved in acute inflammatory edema. The TRPA1 agonist allyl isothiocyanate (AITC) induced inflammatory edema when injected intraplantarly to mice, mimicking the classical response to carrageenan. Interestingly, the TRPA1 antagonist HC-030031 and the cyclo-oxygenase (COX) inhibitor ibuprofen inhibited not only AITC but also carrageenan-induced edema. TRPA1-deficient mice displayed attenuated responses to carrageenan and AITC. Furthermore, AITC enhanced COX-2 expression in HEK293 cells transfected with human TRPA1, a response that was reversed by HC-030031. This study demonstrates a hitherto unknown role of TRPA1 in carrageenan-induced inflammatory edema. The results also strongly suggest that TRPA1 contributes, in a COX-dependent manner, to the development of acute inflammation

    Continuous and transparent multimodal authentication: reviewing the state of the art

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    Individuals, businesses and governments undertake an ever-growing range of activities online and via various Internet-enabled digital devices. Unfortunately, these activities, services, information and devices are the targets of cybercrimes. Verifying the user legitimacy to use/access a digital device or service has become of the utmost importance. Authentication is the frontline countermeasure of ensuring only the authorized user is granted access; however, it has historically suffered from a range of issues related to the security and usability of the approaches. They are also still mostly functioning at the point of entry and those performing sort of re-authentication executing it in an intrusive manner. Thus, it is apparent that a more innovative, convenient and secure user authentication solution is vital. This paper reviews the authentication methods along with the current use of authentication technologies, aiming at developing a current state-of-the-art and identifying the open problems to be tackled and available solutions to be adopted. It also investigates whether these authentication technologies have the capability to fill the gap between high security and user satisfaction. This is followed by a literature review of the existing research on continuous and transparent multimodal authentication. It concludes that providing users with adequate protection and convenience requires innovative robust authentication mechanisms to be utilized in a universal level. Ultimately, a potential federated biometric authentication solution is presented; however it needs to be developed and extensively evaluated, thus operating in a transparent, continuous and user-friendly manner

    Solvent-Free Melting Techniques for the Preparation of Lipid-Based Solid Oral Formulations

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