Effects of a ketogenic diet on reproductive and metabolic phenotypes in mice with polycystic ovary syndrome†.

Polycystic ovary syndrome (PCOS) is one of the most common female reproductive and metabolic disorders. The ketogenic diet (KD) is a diet high in fat and low in carbohydrate. The beneficial effects of KD intervention have been demonstrated in obese women with PCOS. The underlying mechanisms, however, remain unknown. The aim of the present study was to investigate the effects of a KD on both reproductive and metabolic phenotypes of dehydroepiandrosterone (DHEA)-induced PCOS mice. Female C57BL/6 mice were divided into three groups, designated Control, DHEA, and DHEA+KD groups. Mice of both Control and DHEA groups were fed the control diet, whereas DHEA+KD mice were fed a KD with 89%(kcal) fat for 1 or 3 weeks after PCOS mouse model was completed. At the end of the experiment, both reproductive and metabolic characteristics were assessed. Our data show that KD treatment significantly increased blood ketone levels, reduced body weight and random and fasting blood glucose levels in DHEA+KD mice compared with DHEA mice. Glucose tolerance, however, was impaired in DHEA+KD mice. Ovarian functions were improved in some DHEAmice after KD feeding, especially in mice treated with KD for 3 weeks. In addition, inflammation and cell apoptosis were inhibited in the ovaries of DHEA+KD mice. Results from in vitro experiments showed that the main ketone body ß-hydroxybutyrate reduced inflammation and cell apoptosis in DHEA-treated KGN cells. These findings support the therapeutic effects of KD and reveal a possible mechanism by which KD improves ovarian functions in PCOS mice.

Eugenol improves salt tolerance via enhancing antioxidant capacity and regulating ionic balance in tobacco seedlings.

Salt stress inhibits plant growth by disturbing plant intrinsic physiology. The application of exogenous plant growth regulators to improve the plant tolerance against salt stress has become one of the promising approaches to promote plant growth in saline environment. Eugenol (4-allyl-2- methoxyphenol) is the main ingredient in clove oil and it is known for its strong antioxidant and anti-microbial activities. Eugenol also has the ability of inhibiting several plant pathogens, implying the potential use of eugenol as an environmental friendly agrichemical. However, little is known about the possible role of eugenol in the regulation of plant tolerance against abiotic stress. Therefore, here we investigated the effectiveness of phytochemical eugenol in promoting salt tolerance in tobacco seedlings through physiological, histochemical, and biochemical method. The seedling roots were exposed to NaCl solution in the presence or absence of eugenol. Salt stress inhibited seedling growth, but eugenol supplementation effectively attenuated its effects in a dose-dependent manner, with an optimal effect at 20 µM. ROS (reactive oxygen species) accumulation was found in seedlings upon salt stress which was further resulted in the amelioration of lipid peroxidation, loss of membrane integrity, and cell death in salt-treated seedlings. Addition of eugenol highly suppressed ROS accumulation and reduced lipid peroxidation generation. Both enzymatic and non-enzymatic antioxidative systems were activated by eugenol treatment. AsA/DHA and GSH/GSSG were also enhanced upon eugenol treatment, which helped maintain redox homeostasis upon salinity. Eugenol treatment resulted in an increase in the content of osmoprotectants (e.g. proline, soluble sugar and starch) in salt-treated seedlings. Na+ levels decreased significantly in seedlings upon eugenol exposure. This may result from the upregulation of the expression of two ionic transporter genes, SOS1 (salt-hypersensitive 1) and NHX1 (Na+/H+ anti-transporter 1). Hierarchical cluster combined correlation analysis uncovered that eugenol induced salt tolerance was mediated by redox homeostasis and maintaining ionic balance in tobacco seedlings. This work reveals that eugenol plays a crucial role in regulating plant resistant physiology. This may extend its biological function as a novel biostimulant and opens up new possibilities for improving crop productivity in the saline agricultural environment.

Hydrogen Sensor Based on NTC Thermistor with Pt-Loaded WO3/SiO2 Coating.

A novel hydrogen sensor based on a negative temperature coefficient (NTC) thermistor with Pt-loaded WO3/SiO2 coating is proposed and demonstrated experimentally. When the Pt-loaded WO3/SiO2 film is exposed to the mixture of air and H2, the exothermic reactions caused by hydrogen and WO3 with the cooperation of the Pt catalyst raise the local temperature of the NTC thermistor and lower its resistance. Hence, hydrogen concentration can be measured by monitoring the voltage across the NTC thermistor in a series circuit. The proposed device has a rapid response time, high sensitivity, and excellent repeatability to hydrogen as well as immunity to humidity, a compact size, a low manufacturing cost, and is easy to use.

Transparent Heat Shielding Properties of Core-Shell Structured Nanocrystalline CsxWO3@TiO2.

Nanocrystalline tungsten bronze is an excellent near-infrared absorbing material, which has a good potential application in the field of transparent heat shielding materials on windows of automobiles or buildings, but it exhibits serious instability in the actual environment, which hinders its further application. In this paper, we coated the CsxWO3 nanoparticles with TiO2 to prepare core-shell structured CsxWO3@TiO2, and its crystal structure and optical properties were studied. The results show that the surface of CsxWO3 nanoparticles is coated with a layer of TiO2 particles with the size of several nanometers, and the shell thickness can be adjusted by the amount of Ti source. The measurement of optical properties illustrates that TiO2-coated CsxWO3 exhibits good stability in actual environment, and its transparent heat shielding performance will decrease with the increase in TiO2 shell thickness. This work provides a new route to promote the applications of tungsten bronze as heat shielding materials.

Observation of frequency-uncorrelated photon pairs generated by counter-propagating spontaneous parametric down-conversion.

We report the generation of frequency-uncorrelated photon pairs from counter-propagating spontaneous parametric down-conversion in a periodically-poled KTP waveguide. The joint spectral intensity of photon pairs is characterized by measuring the corresponding stimulated process, namely, the difference frequency generation process. The experimental result shows a clear uncorrelated joint spectrum, where the backward-propagating photon has a narrow bandwidth of 7.46 GHz and the forward-propagating one has a bandwidth of 0.23 THz like the pump light. The heralded single-photon purity estimated through Schmidt decomposition is as high as 0.996, showing a perspective for ultra-purity and narrow-band single-photon generation. Such unique feature results from the backward-wave quasi-phase-matching condition and does not has a strict limitation on the material and working wavelength, thus fascinating its application in photonic quantum technologies.

Tunable Transparency and NIR-Shielding Properties of Nanocrystalline Sodium Tungsten Bronzes.

The NaxWO3 nanoparticles with different x were synthesized by a solvothermal method and the absorption behavior in visible and near-infrared light (NIR) region was studied. Well-crystallized nanoparticles with sizes of several tens of nanometers were confirmed by XRD, SEM and TEM methods. The absorption valley in visible region shifted from 555 nm to 514 nm and the corresponding absorption peak in NIR region shifted from 1733 nm to 1498 nm with the increasing x. In addition, the extinction behavior of NaxWO3 nanoparticles with higher x values were simulated by discrete dipole approximation method and results showed that the changing behavior of optical properties was in good agreement with the experimental results. The experimental and theoretical data indicate that the transparency and NIR-shielding properties of NaxWO3 nanoparticles in the visible and NIR region can be continuously adjusted by x value in the whole range of 0 < x < 1. These tunable optical properties of nanocrystalline NaxWO3 will expand its application in the fields of transparent heat-shielding materials or optical filters.

Compact polarization-entangled photon-pair source based on a dual-periodically-poled Ti:LiNbO3 waveguide.

We present an experimental realization of a compact and reliable way to build a nondegenerate polarization-entangled photon-pair source based on a dual-periodically-poled $ {\rm Ti}:{{\rm LiNbO}_3} $Ti:LiNbO3 waveguide, which is in the telecommunication window and compatible with the fiber quantum networks. The dual-periodic structure allows two inherently concurrent quasiphase-matching spontaneous parametric down-conversion processes pumped by a single laser beam, hence enabling our source to be compact and stable. We show that our source has a high brightness of $ B = 1.22{\rm } \times {\rm }{10^7}\;{\rm pairs}/(\rm s \times mW \times nm) $B=1.22×107pairs/(s×mW×nm). With quantum state tomography, we estimate an entanglement fidelity of $ 0.945 \pm 0.003 $0.945±0.003. A violation of Clauser-Horne-Shimony-Holt inequality with $ S = 2.75 \pm 0.03 $S=2.75±0.03 is also demonstrated.

Ghrelin Promotes Cortical Neurites Growth in Late Stage After Oxygen-Glucose Deprivation/Reperfusion Injury.

Acyl ghrelin, a novel brain-gut peptide, is an endogenous ligand for the growth hormone secretagogue receptor. Accumulated research data have shown that acyl ghrelin exercises a significant neuroprotective effect against cerebral ischemia/reperfusion (I/R) injury in animal models and in cultured neurons during the acute phase, usually, 1 day after cerebral ischemia. The chronic effects of acyl ghrelin 1 week after brain ischemia remain largely unknown. In this study, we explored the effects of acyl ghrelin on cultured organotypic brain slices and cortical neurons which were injured by oxygen-glucose deprivation/reperfusion(OGD/R) for 7 days. The underlying molecular mechanisms were deciphered based on label-free proteomic analysis. Acyl ghrelin treatment promoted neurite (axons and dendrites) growth and alleviated the neuronal damage in both cultured brain slices and neurons. Proteomic analysis showed that cell division control protein 42 (Cdc42) mediates the effects of acyl ghrelin on neurite growth. Acyl ghrelin stimulated the expression of Cdc42 and neurite growth in cultured neurons comparing with OGD/R group. Inhibition of Cdc42 attenuated the effects of acyl ghrelin. These results suggest that acyl ghrelin promotes neurite growth during the later stage after OGD/R injury via Cdc42. Our study suggests that acyl ghrelin may be promising to restore the neuronal structure in the late phase after stroke.

A model of acute compressive spinal cord injury with a minimally invasive balloon in goats.

Research into spinal cord injury depends upon animal models of trauma. While investigations using small animals have yielded critical insights into the cellular mechanisms of neurotrauma, no effective therapies have been translated to human clinical treatments. There are considerable differences in pathophysiology, scale, and anatomical organization between rodents and primates. Here, the established method of inflating balloons to compress the cord within the spinal canal was adapted for use in goats. By using surgical techniques to insert a kyphoplasty balloon, spinal cord injury was accomplished with minimal trauma to the surrounding tissues, as is common in other traumatic models. Dye volumes of 0, 1.26 ± 0.18, and 2.82 ± 0.20 mL were injected into the balloon to produce spinal occupancies of 0%, 33 ± 2%, and 89 ± 4%, as evaluated by X-ray and computerized tomography imaging. A significant dose response was observed for the different levels of trauma, with reduced conduction of somatosensory evoked potentials and impaired mobility 7 days after injury. From the strong correlations between injection volume, balloon pressure, spinal occupancy, nerve function, and animal behavior, we conclude that hydraulic compression in goats is a useful model of spinal cord injury.