A through-space charge transfer pyrene-based fluorophore with anti-quenching behavior for deep-blue organic light-emitting devices.

A through-space charge transfer pyrene-based fluorophore has been developed for organic light-emitting devices (OLEDs). This material exhibits deep-blue fluorescence, bipolar characteristics, and anti-quenching behavior in the solid state. It proves to be an effective emitter for both doped and nondoped deep-blue OLEDs.

Risk factors for hemodynamic instability during laparoscopic resection of pheochromocytoma.

BACKGROUND: Laparoscopic adrenalectomy for pheochromocytoma is associated with high risk of intraoperative hemodynamic instability. Our study aimed to identify predictive factors for hemodynamic instability during laparoscopic resection of pheochromocytoma. METHODS: Between January 2011 and December 2021, 136 patients underwent unilateral laparoscopic adrenalectomy for pheochromocytoma. The patients were divided into 2 groups depending on the presence or absence of hemodynamic instability during surgery. Intraoperative hemodynamic parameters were compared between the 2 groups. Patient demographic characteristics and preoperative evaluations were assessed for their prognostic relevance with respect to intraoperative hemodynamic instability via both univariate analysis and multivariate logistic regression analysis. RESULTS: There was greater blood pressure fluctuations and higher maximum blood pressure and heart rate in the hemodynamic instability group. More patients need intraoperative administration of vasoactive drugs in the hemodynamic instability group. In the univariate analysis, presence of coronary artery disease, tumour size, and previous hypertension history were significantly associated with intraoperative hemodynamic instability. The multivariate logistic regression analysis showed that tumour size and previous hypertension history were independent risk factors for intraoperative hemodynamic instability. CONCLUSION: Tumour size and previous hypertension history were associated with hemodynamic instability during laparoscopic resection of pheochromocytoma.

Modulating effects of on-line low frequency electromagnetic fields on hippocampal long-term potentiation in young male Sprague-Dawley rat.

The low frequency electromagnetic fields (LF-EMFs) are attracting more attention and studied deeply because of their effects on human health and biology. Recent reports indicate that exposure of rats to LF-EMFs induces persistent changes in neuronal activity. The studies used the following standard methods: the rats or rat brain slices were first stimulated in an external electromagnetic exposure system, and then moved to a patch clamp perfusion chamber to record electrophysiological characteristics (off-line magnetic exposure). However, this approach is susceptible to many disturbances, such as the effects of brain slice movements. In this paper, we describe a novel patch-clamp setup which is modified to allow accurate on-line LF-EMFs stimulation. We performed the computational simulations of the stimulation coils to describe the uniformity of the distribution of the on-line magnetic field. The 0.5, 1, 2 mT magnetic field of 15 Hz, 50 Hz, and 100 Hz was produced and applied to slices to study the effect of LF-EMFs on synaptic plasticity. We demonstrated that the slope of field excitatory postsynaptic potentials (fEPSPs) decreased significantly under the priming on-line uninterrupted or pulsed sinusoidal LF-EMFs stimulation. In the present study, we investigated whether LF-EMFs can induce long-term potentiation (LTP) in male Sprague-Dawley rat hippocampal slices in vitro. Interestingly, these results highlight the role of 100 Hz pulsed sinusoidal LF-EMFs only as a modulator, rather than an LTP inducer.

Simulation and experimental study of DC electric field distribution characteristics of rat hippocampal slices in vitro.

Direct current (DC) electric field is a noninvasive neuromodulation tool that can inhibit or facilitate excitability of neurons. Despite its efficacy, the dielectric constant of artificial cerebrospinal fluid and the position and direction of brain slices and other factors can affect the field intensity and distribution acting on the surface of rat hippocampus slices, thus causing errors. In this study, we describe a new analytical method optimized for DC electric fields acting on brain slices, and the design of an external DC electric field stimulator to allow scientific evaluation of brain slices. We investigated parameters regarding the uniformity of electric field distribution and identified the maximal parameters using the finite element method. Then, we selected and simplified slice images using magnetic resonance imaging data and calculated the electric field intensity of the original and simplified models. The electric field simulator induced action potential and excitatory postsynaptic current with intensities of 1, 5, and 10 V/m. This study describes the development of a new electric field stimulator and successfully demonstrates its practicability for scientific evaluation of tissue slices.