FMR Study of Co/Ti Bilayer Thin Films

. We focused on the interaction between two ferromagnetic cobalt layers through a non-magnetic titanium layer. The magnetic properties of the structure were characterized by ferromagnetic resonance technique (FMR). The data were collected as a function of non-magnetic titanium layer thickness. Co/Ti multilayer (Ti (50 {\AA})/Co(45 {\AA})/Ti(2-40 {\AA})/Co(40 {\AA})/Ti(100 {\AA}))films were grown onto naturally oxidized p-type single crystal Si (100) substrate at UHV condition with magnetron sputtering system at room temperature. The thickness of Ti spacer layer ranges from 2 to 40 {\AA} with 2 {\AA} steps. We did not observe usual optic and acoustic modes; instead we had two broad overlapped peaks for the films ranged from 6 {\AA} to 40 {\AA}. One interesting result was the high anisotropic resonance field values for these films. Exchange coupling between ferromagnetic layers causes shift on resonance field values but these shifts in our samples were much larger than expected. This large anisotropic behavior is not clear at the moment. Our theoretical model was not able to determine a value for the exchange coupling parameter. One reason can be the close thickness values for Co sublayers. The other reason can be the Ti non-magnetic layer. If titanium did not grow layer by layer on cobalt, the cobalt ferromagnetic layers may behave as a single layer. As a result one cannot observe exchange interaction between ferromagnetic layers through non-magnetic spacer.Comment: 6 pages, 5 figure

The Evolving Paradigm in the Management of Intracranial Atherosclerotic Disease

Intracranial atherosclerotic disease (ICAD) is a major cause of ischemic stroke worldwide and represents a significant health problem. The pathogenesis and natural history of ICAD are poorly understood, and rigorous treatment paradigms do not exist as they do for extracranial atherosclerosis. Currently, the best treatment for ICAD remains aspirin therapy, but many patients who are placed on aspirin continue to experience recurrent strokes. As microsurgical and endovascular techniques continue to evolve, the role of extracranial to intracranial bypass operations and stenting are increasingly being reconsidered. We performed a PubMed review of the English literature with a particular focus on treatment options for ICAD and present evidence-based data for the role of surgery and stenting in ICAD against medical therapy alone

No significant association between the promoter region polymorphisms of factor VII gene and risk of venous thrombosis in cancer patients

Factor VII (FVII) plays an important role in blood coagulation. The role of common polymorphisms influencing the FVII plasma levels in thromboembolic disorders has been evaluated but there is no published data related to the effect of FVII gene polymorphisms on the venous thrombosis risk in cancer. Aim: To investigate the association of three common functional polymorphisms in the promoter region of FVII gene: a decanucleotide insertion at position-323 (-323ins10-bp), a G to T substitution at position-401 (-401GT), and a G to A substitution at position-402 (-401GT) with venous thrombosis in cancer patients. Materials and Methods: The study included 60 cancer patients with venous thromboembolism (VTE) (group 1) and 130 cancer patients without VTE (group 2). Genotyping of -323ins10-bp, -401GT, and -402GA polymorphisms in the promoter region of FVII gene was performed by the method of single-strand conformation polymorphism analysis and sequencing. Factor V Leiden (FVL) was also determined in all cases. Results: The frequency of FVL was significantly greater in cancer patients with VTE compared with group 2 patients (p 0.05). The results did not change significantly after the exclusion of patients carrying the FVL (p > 0.05). Conclusions: The screening for the -323ins10-bp, -401GT, and -402GA olymorphisms of FVII gene did not contribute to a meaningful diagnostic nvestigation in cancer patients with venous thrombosis

From Virtual to Physical: Integration of Chemical Logic Gates

Cataloged from PDF version of article.Integration by parts: Advanced information processing at the molecular level requires integrated logic gates, which has to date been possible only virtually. Now, two independently working AND molecular logic gates are brought together by "click" chemistry to form integrated logic gates which respond exactly as predicted from such an integration scheme (see picture, EET=excitation energy transfer). Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim

Expanded Bodipy Dyes: Anion Sensing Using a Bodipy Analog with an Additional Difluoroboron Bridge

Cataloged from PDF version of article.Oxalyl-tethered pyrroles can be doubly bridged with two difluoroboron chelating units to yield bright orange dyes. Interestingly, in polar organic solvents, the addition of fluoride and cyanide result in reversible detachment of the otherwise stable difluoroboron bridges, resulting in sharp changes in color. Thus, this novel compound behaves as a highly selective chromogenic sensor for fluoride and cyanide ions

A Theoretical Approach for Determining Irregularities of the Bottom of the Tillage Layer Caused by Horizontal Axis Rotary Tillers

Horizontal axis rotary tillers produce irregularities in the tillage depth when they are inappropriately operated and constructed. In such cases, mixing and breaking of soil throughout the tillage layer is not uniform and some untilled ridges will remain at the bottom determining the effect of design and operational characteristics on the height of the resultant ridges at the bottom of the tillage layer. In this study, a method based on the derived geometrical relationships between the rotary tiller operational parameters was developed to determine heights of ridges occurring at the bottom of the tillage layer. The ridge heights can be calculated for various combinations of blade peripheral speed, forward travel speed, rotor radius, and the number of blades on one side of a rotary tiller flange. This method allows for the investigation of effects of rotary tiller operational and constructional properties of horizontal axis rotary tillers on the ridge heights at the bottom of the tillage layers. The results obtained using this method show that the heights of ridges at the bottom of the tillage layer increase with increases in forward travel speed and decrease with increases in blade peripheral speed, rotor radius, and the number of blades on one side of a flange

Linked CSF reduction of phosphorylated tau and IL-8 in HIV associated neurocognitive disorder.

HIV-associated neurocognitive disorder (HAND) is a common condition in both developed and developing nations, but its cause is largely unknown. Previous research has inconsistently linked Alzheimer's disease (AD), viral burden, and inflammation to the onset of HAND in HIV-infected individuals. Here we simultaneously measured cerebrospinal fluid (CSF) levels of established amyloid and tau biomarkers for AD, viral copy numbers, and six key cytokines in 41 HIV-infected individuals off combination anti-retroviral therapy (14 with HAND) who underwent detailed clinical and neuropsychological characterization, and compared their CSF patterns with those from young healthy subjects, older healthy subjects with normal cognition, and older people with AD. HAND was associated with the lowest CSF levels of phosphorylated tau (p-Tau181) after accounting for age and race. We also found very high CSF levels of the pro-inflammatory interferon gamma-induced protein 10 (IP-10/CXCL10) in HIV regardless of cognition, but elevated CSF interleukin 8 (IL-8/CXCL8) only in HIV-NC but not HAND. Eleven HIV-infected subjects underwent repeat CSF collection six months later and showed strongly correlated longitudinal changes in p-Tau181 and IL-8 levels (R = 0.841). These data suggest reduced IL-8 relative to IP-10 and reduced p-Tau181 to characterize HAND