Intrinsic EPR in La2-xSrxCuO4: Manifestation of three-spin polarons

Electron-paramagnetic resonance (EPR) measurements on La2-xSrxCuO4provide experimental evidence of a three-spin polaren, consisting of two Cu2+ ions and one p hole. The symmetry properties and the peculiar temperature dependence of the g values of the EPR line indicate the presence of dynamical Jahn-Teller distortions and formation of a collective mode of polarons and surrounding strongly correlated Cu ions (bottlenecked regime)

Mechanical Circulatory Support in Cardiogenic Shock due to Structural Heart Disease

Despite advances in cardiovascular care, managing cardiogenic shock caused by structural heart disease is challenging. Patients with cardiogenic shock are critically ill upon presentation and require early disease recognition and rapid escalation of care. Temporary mechanical circulatory support provides a higher level of care than current medical therapies such as vasopressors and inotropes. This review article focuses on the role of hemodynamic monitoring, mechanical circulatory support, and device selection in patients who present with cardiogenic shock due to structural heart disease. Early initiation of appropriate mechanical circulatory support may reduce morbidity and mortality

In Vivo Assessment of Cold Adaptation in Insect Larvae by Magnetic Resonance Imaging and Magnetic Resonance Spectroscopy

Background Temperatures below the freezing point of water and the ensuing ice crystal formation pose serious challenges to cell structure and function. Consequently, species living in seasonally cold environments have evolved a multitude of strategies to reorganize their cellular architecture and metabolism, and the underlying mechanisms are crucial to our understanding of life. In multicellular organisms, and poikilotherm animals in particular, our knowledge about these processes is almost exclusively due to invasive studies, thereby limiting the range of conclusions that can be drawn about intact living systems. Methodology Given that non-destructive techniques like 1H Magnetic Resonance (MR) imaging and spectroscopy have proven useful for in vivo investigations of a wide range of biological systems, we aimed at evaluating their potential to observe cold adaptations in living insect larvae. Specifically, we chose two cold-hardy insect species that frequently serve as cryobiological model systems–the freeze-avoiding gall moth Epiblema scudderiana and the freeze-tolerant gall fly Eurosta solidaginis. Results In vivo MR images were acquired from autumn-collected larvae at temperatures between 0°C and about -70°C and at spatial resolutions down to 27 µm. These images revealed three-dimensional (3D) larval anatomy at a level of detail currently not in reach of other in vivo techniques. Furthermore, they allowed visualization of the 3D distribution of the remaining liquid water and of the endogenous cryoprotectants at subzero temperatures, and temperature-weighted images of these distributions could be derived. Finally, individual fat body cells and their nuclei could be identified in intact frozen Eurosta larvae. Conclusions These findings suggest that high resolution MR techniques provide for interesting methodological options in comparative cryobiological investigations, especially in vivo

Comparison of the optoacoustic signal generation efficiency of different nanoparticular contrast agents

Optoacoustic imaging represents a new modality that allows noninvasive in vivo molecular imaging with optical contrast and acoustical resolution. Whereas structural or functional imaging applications such as imaging of vasculature do not require contrast enhancing agents, nanoprobes with defined biochemical binding behavior are needed for molecular imaging tasks. Since the contrast of this modality is based on the local optical absorption coefficient, all particle or molecule types that show significant absorption cross sections in the spectral range of the laser wavelength used for signal generation are suitable contrast agents. Currently, several particle types such as gold nanospheres, nanoshells, nanorods, or polymer particles are used as optoacoustic contrast agents. These particles have specific advantages with respect to their absorption properties, or in terms of biologically relevant features (biodegradability, binding to molecular markers). In the present study, a comparative analysis of the signal generation efficiency of gold nanorods, polymeric particles, and magnetite particles using a 1064 nm Nd:YAG laser for signal generation is described

Developing a high-resolution photoacoustic microscopy platform

Existing optical imaging modalities including confocal microscopy, two-photon microscopy and optical coherence tomography do not image optical absorption directly. Photoacoustic imaging (also called optoacoustic imaging) is a new promising modality in biomedical imaging integrating the benefits of optics and acoustics. When biological tissue is irradiated with ultrashort laserpulses with durations of a few nanoseconds the light is absorbed according to the local absorption properties and is converted successively into heat and pressure by means of the thermoelastic effect. The motivation for photoacoustic imaging is to combine ultrasonic resolution with high contrast due to light absorption depending on the physiology of the examined biological tissue. The resolution of conventional photoacoustic imaging systems is not sufficient for in-vitro measurements of small tissue samples or individual cells. In this work, we present a high-resolution photoacoustic microscopy pla tform based on the SASAM acoustic microscope (Kibero GmbH, Germany) that allows high resolution imaging on living cells. The system based on an inverted optical microscope consists of a laser source for optical multi wavelength excitation (diode- or solidstate- laser) which emits nanosecond laser pulses with a wavelength in the near infrared spectrum (optical window). We use different ultrasound transducers in the frequency range up to 300 MHz for detection of the pressure transients. Read out electronics combined with reconstruction algorithms for photoacoustic imaging allows converting the recorded signals into a spatial representation of the absorbed energy. Furthermore, the possibility of using nanoscaled contrast agents for photoacoustic contrast enhancement is presented. In addition to the photoacoustic imaging mode all common optical modalities are implemented. Pure acoustic imaging and optical transmission mode are used for reference imaging

Intrinsic EPR in La2-xSrxCuO4: Manifestation of three-spin polarons

Electron-paramagnetic resonance (EPR) measurements on La2-xSrxCuO4provide experimental evidence of a three-spin polaren, consisting of two Cu2+ ions and one p hole. The symmetry properties and the peculiar temperature dependence of the g values of the EPR line indicate the presence of dynamical Jahn-Teller distortions and formation of a collective mode of polarons and surrounding strongly correlated Cu ions (bottlenecked regime)

Intrinsic EPR in La2-xSrxCuO4: Manifestation of three-spin polarons

Electron-paramagnetic resonance (EPR) measurements on La2-xSrxCuO4provide experimental evidence of a three-spin polaren, consisting of two Cu2+ ions and one p hole. The symmetry properties and the peculiar temperature dependence of the g values of the EPR line indicate the presence of dynamical Jahn-Teller distortions and formation of a collective mode of polarons and surrounding strongly correlated Cu ions (bottlenecked regime)

Intrinsic EPR in La2-xSrxCuO4: Manifestation of three-spin polarons

Electron-paramagnetic resonance (EPR) measurements on La2-xSrxCuO4provide experimental evidence of a three-spin polaren, consisting of two Cu2+ ions and one p hole. The symmetry properties and the peculiar temperature dependence of the g values of the EPR line indicate the presence of dynamical Jahn-Teller distortions and formation of a collective mode of polarons and surrounding strongly correlated Cu ions (bottlenecked regime)

Sarcoid uveitis: A look beyond the eyes

Background: Bilateral acute uveitis can cause significant morbidity, and a complete workup is often warranted. This report illustrates a case of sarcoid uveitis definitively diagnosed by skin biopsy in a patient with red tattoo ink. Case Report: A 40-year-old African American male presented with bilateral photophobia and intraocular pressures of 26 mmHg in both eyes, 1þ grade cell and flare in both eyes, and granulomatous (mutton fat) keratic precipitates in both eyes. Serum angiotensin-converting enzyme level was elevated at 146 U/mL (normal valu