Search

The goal of this study was to evaluate sensitivity of intraoperative Computed Tomography (iCT) imaging for the detection of orbital foreign bodies (OFBs) in an in vitro model and evaluate iCT efficacy for surgical planning of OFB detection and removal in veterinary patients. Three canine patients were presented to our hospital for potential orbital foreign body removal. In vitro studies were conducted using a canine skull model with placement of various OFBs. Four different examiners utilized CT imaging to evaluate the detection of OFBs. A surgical navigation system was employed to assess the feasibility of stereotactic orbital foreign body retrieval in vitro. iCT imaging was applied for surgical planning and guidance of orbital surgery for the removal of OFBs in three clinical patients. In vitro experiments revealed a high detection rate for objects with high radiopacity such as metal and glass. The detection rate for organic foreign bodies such as wood was moderate, while for plastic foreign bodies ranged from moderate to low. Navigation was successfully used for OFB retrieval. iCT was effectively employed for detecting OFBs in clinical patients. However, porcupine quills were better detected using standard ultrasound imaging. The use of iCT potentially represents an evolving technological practice that enables real-time imaging to improve the precision of surgical procedures.

The rapid spread of the Internet of Things (IoT) along with the development of innovative low-power electronic devices has also driven the development of indoor photovoltaics. In this paper, we propose a simple and economically feasible solution that can improve the efficiency of dye-sensitized solar cells (DSSCs) under indoor light conditions by ~112%, without requiring a complex TiO2 photoanode architecture or the design of new dyes. The ball milling process of the TiO2 paste was optimized for indoor light conditions for the first time, both in terms of efficiency and production costs, by developing a rapid preparation method that can be used industrially for the application of DSSCs. A simple use of 12 mm diameter balls caused beneficial structural modifications, decreasing the size of the crystallites, and leading to a high OH generation on the TiO2 surface responsible for the improvement of energy conversion efficiency. [ABSTRACT FROM AUTHOR]

Cuprous oxide with different morphologies (3D hierarchical structure consisting of the micrometer dendritic rods and the porous truncated octahedrons) has been successfully synthesized via a facile one-step hydrothermal method using copper (II) acetate and ethyl cellulose as reactants. The p-type dye-sensitized solar cell based on the micrometer porous structure exhibits approximately 15% increase in JSC and VOC than 3D hierarchical structure. This enhancement could be explained by the high dye loading capacity of this porous structure and lowering the recombination process at the oxide/dye/electrolyte interface.

Bismuth ferrite (BiFeO3, BFO) is still widely investigated both because of the great diversity of its possible applications and from the perspective of intrinsic defect engineering in the perovskite structure. Defect control in BiFeO3 semiconductors could provide a key technology for overcoming undesirable limitations, namely, a strong leakage current, which is attributed to the presence of oxygen vacancies (VO) and Bi vacancies (VBi). Our study proposes a hydrothermal method for the reduction of the concentration of VBi during the ceramic synthesis of BiFeO3.Using hydrogen peroxide (H2O2) as part of the medium, p-type BiFeO3 ceramics characterized by their low conductivity were obtained. Hydrogen peroxide acted as the electron donor in the perovskite structure, controlling VBi in the BiFeO3 semiconductor, which caused the dielectric constant and loss to decrease along with the electrical resistivity. The reduction of Bi vacancies highlighted by a FT-IR and Mott—Schottky analysis has an expected contribution to the dielectric characteristic. A decrease in the dielectric constant (with approximately 40%) and loss (3 times) and an increase of the electrical resistivity (by 3 times) was achieved by the hydrogen peroxide-assisted hydrothermal synthesized BFO ceramics, as compared with the hydrothermal synthesized BFOs. [ABSTRACT FROM AUTHOR]

Fabrication of flexible p-type dye-sensitized solar cells with large short-circuit current (JSC) and open circuit voltage (VOC) is still a challenging problem. In this context, we report the construction and testing of a p-type dye-sensitized solar cell (DSSC) based on a porous Cu2O thin film on copper substrate as a free-binder photoelectrode, using P1 dye and an electrolyte based on the I3−/I− redox couple. A simple and low-cost hydrothermal method is proposed using ethyl cellulose or polyvinylpyrrolidone as a surfactant to synthesize the porous Cu2O thin film on copper substrate. The best cell yielded a high short-circuit current density JSC of 11.7 mA cm−2, an open-circuit voltage VOC of 0.502 V and a power conversion efficiency η of 1.32% under 1 sun. The porous structure of the Cu2O film caused by ethyl cellulose is responsible for the high JSC, providing the high dye loading capacity of the DSSC due to their large specific surface areas and highly efficient visible light-harvesting ability. Even if further improvement is requested, the high short-circuit current density value highlighted that this flexible photocathode could be considered an interesting candidate for the development of flexible p-type or tandem dye-sensitized solar cells. [ABSTRACT FROM AUTHOR]

[Ca.sup.2+] channels play crucial roles in cellular signal transduction and are important targets of pharmacological agents. They are also associated with auxiliary subunits exhibiting functions that are still incompletely resolved. Skeletal muscle L-type [Ca.sup.2+] channels (dihydropyridine receptors, DHPRs) are specialized for the remote voltage control of type 1 ryanodine receptors (RyR1) to release stored [Ca.sup.2+]. The skeletal muscle-specific 1, subunit of the DHPR ([[gamma].sub.1]) down-modulates availability by altering its steady state voltage dependence. The effect resembles the action of certain [Ca.sup.2+] antagonistic drugs that are thought to stabilize inactivated states of the DHPR. In the present study we investigated the cross influence of [[gamma].sub.1] and [Ca.sup.2+] antagonists by using wild-type ([gamma]+/+) and [[gamma].sub.1] knockout ([gamma]-/-) mice. We studied voltage-dependent gating of both L-type [Ca.sup.2+] current and [Ca.sup.2+] release and the allosteric modulation of drug binding. We found that 10 [micro]M diltiazem, a benzothiazepine drug, more than compensated for the reduction in high-affinity binding of the dihydropyridine agent isradipine caused by [[gamma].sub.1] elimination; 5 [micro]M devapamil [(-)D888], a phenylalkylamine [Ca.sup.2+] antagonist, approximately reversed the right-shifted voltage dependence of availability and the accelerated recovery kinetics of [Ca.sup.2+] current and [Ca.sup.2+] release. Moreover, the presence of [[gamma].sub.1] altered the effect of D888 on availability and strongly enhanced its impact on recovery kinetics demonstrating that [[gamma].sub.1] and the drug do not act independently of each other. We propose that the [[gamma].sub.1] subunit of the DHPR functions as an endogenous [Ca.sup.2+] antagonist whose task may be to minimize [Ca.sup.2+] entry and [Ca.sup.2+] release under stress-induced conditions favoring plasmalemma depolarization.

Functional impacts of the skeletal muscle-specific [Ca.sup.2+] channel subunit [[gamma].sub.1] have previously been studied using coexpression with the cardiac [[alpha].sub.1C] polypeptide in nonmuscle cells and primary-cultured myotubes of [[gamma].sub.1]-deficient mice. Data from single adult muscle fibers of [gamma]-/- mice are not yet available. In the present study, we performed voltage clamp experiments on enzymatically isolated mature muscle fibers of the m. interosseus obtained from [gamma]+/+ and [gamma]-/- mice. We measured L-type [Ca.sup.2+] inward currents and intracellular [Ca.sup.2+] transients during 100-ms step depolarizations from a holding potential of -80 mV. Radometric [Ca.sup.2+] transients were analyzed with a removal model fit approach to calculate the flux of [Ca.sup.2+] from the sarcoplasmic reticulum. [Ca.sup.2+] current density [Ca.sup.2+] release flux, and the voltage dependence of activation of both [Ca.sup.2+] current and [Ca.sup.2+] release were not significantly different. By varying the holding potential and recording [Ca.sup.2+] current and [Ca.sup.2+] release flux induced by 100-ms test depolarizations to +20 mV, we studied quasi-steady-state properties of slow voltage-dependent inactivation. For the [Ca.sup.2+] current, these experiments showed a right-shifted voltage dependence of inactivation. Importantly, we could demonstrate that a very similar shift occurred also in the inactivation curve of [Ca.sup.2+] release. Voltages of half maximal inactivation were altered by 16 (current) and 14 mV (release), respectively; Muscle fiber bundles, activated by elevated potassium concentration (120 mM), developed about threefold larger contracture force in [gamma]-/- compared with [gamma]+/+. This difference was independent of the presence of extracellular [Ca.sup.2+] and likely results from the lower sensitivity to voltage-dependent inactivation of [Ca.sup.2+] release. These results demonstrate a specific alteration of voltage-dependent inactivation of both [Ca.sup.2+] entry and [Ca.sup.2+] release by the [[gamma].sub.1] submit of the dihydropyridine receptor in mature muscle fiber's of file moose. KEY WORDS: mammalian skeletal muscle * excitation--contraction coupling * accessory subunits * knockout mouse * voltage