Search results for "RESISTANCE"
showing 10 items of 3641 documents
Perspectives and Potential Applications of Mitochondria-Targeted Antioxidants in Cardiometabolic Diseases and Type 2 Diabetes
2013
There is abundant evidence to suggest that mitochondrial dysfunction is a main cause of insulin resistance and related cardiometabolic comorbidities. On the other hand, insulin resistance is one of the main characteristics of type 2 diabetes, obesity, and metabolic syndrome. Lipid and glucose metabolism require mitochondria to generate energy, and when O2 consumption is low due to inefficient nutrient oxidation, there is an increase in reactive oxygen species, which can impair different types of molecules, including DNA, lipids, proteins, and carbohydrates, thereby inducing proinflammatory processes. Factors which contribute to mitochondrial dysfunction, such as mitochondrial biogenesis and…
<p>Circulating Irisin Levels as a Marker of Osteosarcopenic-Obesity in Cushing’s Disease</p>
2020
Purpose To evaluate circulating irisin levels in patients with active and controlled Cushing's disease (CD). Design Forty-four patients with CD evaluated during the active phase and after 12 months of biochemical remission and 40 controls were recruited. Methods Phenotypic, anthropometric, hormonal and metabolic parameters, including insulin sensitivity estimation by homeostatic model of insulin resistance, Matsuda index and oral disposition index and circulating irisin levels were evaluated. Results Patients with active CD showed lower irisin levels compared to controls (p<0.001) and controlled CD (p<0.001). The independent variables significantly associated with irisin were waist circumf…
Inhibitors of antibiotic resistance mechanisms: clinical applications and future perspectives
2020
Bacterial strains responsible for antibiotic resistant infections are increasing in an alarming way and the evolution of resistance mechanisms seems to be unstoppable. In the past decade, many efforts have been made in order to counteract this phenomenon but very few compounds have reached clinical trials. The development of new classes of antibiotics able to overcome the main bacterial drug resistance mechanisms is urgently required to counter the imminent danger of a postantibiotic era.
Spin transport across antiferromagnets induced by the spin Seebeck effect
2018
For prospective spintronics devices based on the propagation of pure spin currents, antiferromagnets are an interesting class of materials that potentially entail a number of advantages as compared to ferromagnets. Here, we present a detailed theoretical study of magnonic spin current transport in ferromagnetic-antiferromagnetic multilayers by using atomistic spin dynamics simulations. The relevant length scales of magnonic spin transport in antiferromagnets are determined. We demonstrate the transfer of angular momentum from a ferromagnet into an antiferromagnet due to the excitation of only one magnon branch in the antiferromagnet. As an experimental system, we ascertain the transport acr…
Novel phase transitions in B-site doped manganites
2005
We have examined the infrared reflectivity and the electrical resistivity of La 1-x [Sr(Ba)] x Mn 1-z [Cu(Zn)] z O 3 samples in ferromagnetic metallic and insulator regime. Several phase transitions are observed, the most obvious being the transition from a ferromagnetic metallic to a ferromagnetic insulator phase that is related to the formation of short-range orbitally ordered domains. The temperature T 1 of the phase transition is dependent on doping concentration and for optimally doped samples (∼32% of Mn 4+ ions) we have found T 1 0.93 T C .
Quantum size effects in solitary wires of bismuth
2007
We have performed four-probe electrical transport measurements on solitary highly crystalline wires of semimetallic bismuth with aspect ratios up to 60 at room and at cryogenic temperatures. By proper choice of the substrate material and the film deposition parameters, lithographic wires with lateral dimensions of down to one single grain, $\sim 250$ nm, were fabricated. The electrical resistance of each wire was measured against its thickness through successive reactive ion etching of the self-same wire. Quantum size effects revealed themselves as regular oscillations in the electrical resistance. Some evidence for the semimetal-to-semiconductor phase transition has been detected. The meas…
Magnetotransport Properties of Thin Films of Magnetic Perovskites
2007
In this article we show magnetotransport of two prototypical (nearly) half metallic perowskites La2/3Ca1/3MnO3 and Sr2FeMoO6. In a half metal the spin polarisation at the Fermi energy is complete and tunneling magnetoresistive devices of high sensitivity can be realized with small external magnetic fields. In the vicinity of the metal-insulator phase transition (MIT) temperature of the manganite an external magnetic field can induce ’colossal’ magnetoresistive effects. In the simple perovskites La1-x Ca x MnO3 the charge transport above the MIT is of polaronic nature. Hall-effect measurements on the compound La0.67Ca0.33MnO3 below the MIT show a compensated Fermi-surface consisting of elect…
Anisotropies and magnetic phase transitions in insulating antiferromagnets determined by a Spin-Hall magnetoresistance probe
2019
Antiferromagnets possess a number of intriguing and promising properties for electronic devices, which include a vanishing net magnetic moment and thus insensitivity to large magnetic fields and characteristic terahertz frequency dynamics. However, probing the antiferromagnetic ordering is challenging without synchrotron-based facilities. Here, we determine the material parameters of the insulating iron oxide hematite, α-Fe2O3, using the surface sensitive spin-Hall magnetoresistance (SMR). Combined with a simple analytical model, we extract the antiferromagnetic anisotropies and the bulk Dzyaloshinskii-Moriya field over a wide range of temperatures and magnetic fields. Across the Morin phas…
Confined crystallization of a HKUST-1 metal–organic framework within mesostructured silica with enhanced structural resistance towards water
2017
A HKUST-1 metal–organic framework was crystallized in the NH2-modified mesostructured silica FDU-12 in order to improve its structural stability upon water exposure. In-depth structural characterization studies of the designed composite confirmed successful formation of the MOF phase within the ordered spherical mesopores of the silica matrix. In spite of the confinement within the cavities, MOF exhibits full accessibility for the adsorbed gas molecules. In contrast to the bulk HKUST-1, which undergoes slow phase transition in a humid environment, the structural integrity of the HKUST-1 in the humid-protective matrix remains unchanged even after immersion and stirring in water at elevated t…