The xanthine oxidase (XOD) inhibitory activity and anti-hyperuricemia effect in mice of
Cinnamomum osmophloeum, which is an endemic tree in Taiwan, were evaluated in this study. The results ...demonstrated that the essential oil of
C. osmophloeum leaves presented the strongest XOD inhibition activity (IC
50=16.3
μg/ml); however, no significant XOD inhibition activities were found in ethanolic and hot water extracts. Furthermore, among the main compounds of essential oil, the cinnamaldehyde exhibited the potent XOD inhibition activity with an IC
50=8.4
μg/ml. Besides, the reducing serum uric acid levels in oxonate-induced mice by cinnamaldehyde were further investigated. The hyperuricemic mice were oral administrated cinnamaldehyde at a dosage of 150
mg/kg, the uric acid value in serum was reduced from 5.25±0.63 to 2.10±0.04
mg/dl, the levels of serum uric acid in mice was lowered down by 84.48% as compared to the hyperuricemic control group. Based on the results obtained in this study, cinnamaldehyde may be a potential lead compound for developing the pharmaceutic for anti-hyperuricemia agent.
An eight-channel add-drop cross-grid vertically coupled microring resonator (VCMRR) filter is proposed and demonstrated. The cross grid comprises a grid-like array of buried channel waveguides which ...perpendicularly cross through each other, VCMRRs at each of the cross-grid nodes serve as the wavelength selective add-drop filters. Measured crosstalk levels at the crossings are typically less than -30 dB. Rings with a nominal radius of 10 μm are used to achieve a free-spectral range of 20 nm and optical bandwidths of 1 nm, while changes of the radii in increments of 50 nm lead to a nominal channel spacing of 5.7 nm.
Ring resonators are coupled in parallel in order to obtain a second order type of wavelength response. The phase relationship between the rings determines the details of the spectral response. The ...rings used in the experiment have radii of 25 μm and are fabricated from compound glass having an index of 1.539. Several resonances are observed to have double peaked box-like response.
Bacteria-mediated acquisition of atmospheric N₂ serves as a critical source of nitrogen in terrestrial ecosystems. Here we reveal that symbiotic nitrogen fixation facilitates the cultivation of ...specialized fungal crops by leaf-cutter ants. By using acetylene reduction and stable isotope experiments, we demonstrated that N₂ fixation occurred in the fungus gardens of eight leaf-cutter ant species and, further, that this fixed nitrogen was incorporated into ant biomass. Symbiotic N₂-fixing bacteria were consistently isolated from the fungus gardens of 80 leaf-cutter ant colonies collected in Argentina, Costa Rica, and Panama. The discovery of N₂ fixation within the leaf-cutter ant-microbe symbiosis reveals a previously unrecognized nitrogen source in neotropical ecosystems.
Ultrashort pulsed lasers, operating through the phenomenon of mode-locking, have had a significant role in many facets of our society for 50 years, for example, in the way we exchange information, ...measure and diagnose diseases, process materials, and in many other applications. Recently, high-quality resonators have been exploited to demonstrate optical combs. The ability to phase-lock their modes would allow mode-locked lasers to benefit from their high optical spectral quality, helping to realize novel sources such as precision optical clocks for applications in metrology, telecommunication, microchip-computing, and many other areas. Here we demonstrate the first mode-locked laser based on a microcavity resonator. It operates via a new mode-locking method, which we term filter-driven four-wave mixing, and is based on a CMOS-compatible high quality factor microring resonator. It achieves stable self-starting oscillation with negligible amplitude noise at ultrahigh repetition rates, and spectral linewidths well below 130 kHz.
Alzheimer's disease (AD) genetics implies a causal role for innate immune genes, TREM2 and CD33, products that oppose each other in the downstream Syk tyrosine kinase pathway, activating microglial ...phagocytosis of amyloid (Aβ). We report effects of low (Curc-lo) and high (Curc-hi) doses of curcumin on neuroinflammation in APPsw transgenic mice. Results showed that Curc-lo decreased CD33 and increased TREM2 expression (predicted to decrease AD risk) and also increased TyroBP, which controls a neuroinflammatory gene network implicated in AD as well as phagocytosis markers CD68 and Arg1. Curc-lo coordinately restored tightly correlated relationships between these genes' expression levels, and decreased expression of genes characteristic of toxic pro-inflammatory M1 microglia (CD11b, iNOS, COX-2, IL1β). In contrast, very high dose curcumin did not show these effects, failed to clear amyloid plaques, and dysregulated gene expression relationships. Curc-lo stimulated microglial migration to and phagocytosis of amyloid plaques both in vivo and in ex vivo assays of sections of human AD brain and of mouse brain. Curcumin also reduced levels of miR-155, a micro-RNA reported to drive a neurodegenerative microglial phenotype. In conditions without amyloid (human microglial cells in vitro, aged wild-type mice), Curc-lo similarly decreased CD33 and increased TREM2. Like curcumin, anti-Aβ antibody (also reported to engage the Syk pathway, increase CD68, and decrease amyloid burden in human and mouse brain) increased TREM2 in APPsw mice and decreased amyloid in human AD sections ex vivo. We conclude that curcumin is an immunomodulatory treatment capable of emulating anti-Aβ vaccine in stimulating phagocytic clearance of amyloid by reducing CD33 and increasing TREM2 and TyroBP, while restoring neuroinflammatory networks implicated in neurodegenerative diseases.
•Curcumin (Curc) restores innate immune gene expression in AD models.•Curc increased TREM2 and TYROBP, while decreasing CD33 expression.•Curc stimulates phagocytosis and increases CD68 and Arg1 expression.•Curc reduces pro-inflammatory microglia markers CD11b, iNOS, COX-2, IL1β.•These results support a novel mechanism for Curc, which emulates the Aβ vaccine.
Coronavirus disease 2019 (COVID-19) was first reported in Wuhan in December 2019 and has rapidly spread across different cities within and outside China. Hong Kong started to prepare for COVID-19 on ...31st December 2019 and infection control measures in public hospitals were tightened to limit nosocomial transmission within healthcare facilities. However, the recommendations on the transmission-based precautions required for COVID-19 in hospital settings vary from droplet and contact precautions, to contact and airborne precautions with placement of patients in airborne infection isolation rooms.
To describe an outbreak investigation of a patient with COVID-19 who was nursed in an open cubicle of a general ward before the diagnosis was made.
Contacts were identified and risk categorized as ‘close’ or ‘casual’ for decisions on quarantine and/or medical surveillance. Respiratory specimens were collected from contacts who developed fever, and/or respiratory symptoms during the surveillance period and were tested for SARS-CoV-2.
A total of 71 staff and 49 patients were identified from contact tracing, seven staff and 10 patients fulfilled the criteria of ‘close contact’. At the end of 28-day surveillance, 76 tests were performed on 52 contacts and all were negative, including all patient close contacts and six of the seven staff close contacts. The remaining contacts were asymptomatic throughout the surveillance period.
Our findings suggest that SARS-CoV-2 is not spread by an airborne route, and nosocomial transmissions can be prevented through vigilant basic infection control measures, including wearing of surgical masks, hand and environmental hygiene.
We report measurements of the vacuum ultraviolet (VUV) emission spectra of a microwave-discharge hydrogenflow lamp (MDHL), a common tool in astrochemistry laboratories working on ice VUV ...photoprocessing. The MDHL provides hydrogen Ly- alpha (121.6 nm) and H sub(2) molecular emission in the 110-180 nm range. We show that the spectral characteristics of the VUV light emitted in this range, in particular the relative proportion of Ly- alpha to molecular emission bands, strongly depend on the pressure of H sub(2) inside the lamp, the lamp geometry (F type versus T type), the gas used (pure H sub(2) versus H sub(2) seeded in He), and the optical properties of the window used (MgF sub(2) versus CaF sub(2)). These different configurations are used to study the VUV irradiation of CO ice at 14 K. In contrast to the majority of studies dedicated to the VUV irradiation of astrophysical ice analogs, which have not taken into consideration the emission spectrum of the MDHL, our results show that the processes induced by photons in CO ice from a broad energy range are different and more complex than the sum of individual processes induced by monochromatic sources spanning the same energy range, as a result of the existence of multistate electronic transitions and discrepancy in absorption cross sections between parent molecules and products in the Ly- alpha and H sub(2) molecular emission ranges.
Cadmium (Cd) levels in paddy fields across Taiwan have increased due to emission from industry. To ensure the production of rice that meets food quality standards, predictive models or suitable soil ...tests are needed to evaluate the quality of soils to be used for rice cropping. Levels of Cd in soil and rice grains were measured in 19 paddy fields across the western plains in Taiwan. Cadmium levels in soil range from less than 0.1 mg kg
−1 to 30 mg kg
−1. Measured Cd levels in brown rice were predicted very well (
R
2 > 0.8) based on Cd and Zinc in a 0.01 M CaCl
2 extract or a soil–plant transfer model using the reactive soil Cd content, pH, and cation exchange capacity. In contrast to current soil quality standards used in Taiwan, such models are effective in identifying soils where Cd in rice will exceed food quality standards.
Cadmium uptake by 12 rice cultivars is predicted well by a single soil–plant transfer model based on 0.01 M CaCl
2 or a combination of pH, CEC, and the 0.43 N HNO
3-extractable soil Cd concentration.
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