We report the direct observation of surface‐enhanced Raman scattering (SERS) effect using metal–organic frameworks (MOFs) as substrates. Without the aid of any metal colloids or enhancing agents, the SERS signals of methyl orange (MO) adsorbed in MOFs were observed and even remained active if the organic linkers in MOFs were completely removed by high temperature and O2 plasma treatments. It implies that the SERS active site is at the metal oxide clusters. The ultraviolet‐visible spectra of MO, MOFs, and MO–MOF complexes show that absorption peaks are far from laser excitation line. Thus, conventional resonance enhancement effect should be ruled out, and charge‐transfer mechanism is the most likely scenario responsible for the observed SERS effect. Density functional theory (DFT) was used to interpret the chemical enhancement mechanism and the adsorption orientation‐dependent SERS spectra in our observation. The preferred adsorption orientations calculated by DFT method are consistent with the observed SERS results. Copyright © 2013 John Wiley & Sons, Ltd.

Osteoarthritis (OA) is the most prevalent joint disease that causes an enormous burden of disease worldwide. (-)-Epigallocatechin 3-gallate (EGCG) has been reported to reduce post-traumatic OA progression through its anti-inflammatory property. Aging is the most crucial risk factor of OA, and the majority of OA incidences are related to age and not trauma. In this study, we assess whether EGCG can ameliorate cartilage degradation in primary OA. In an in-vitro study, real-time PCR was performed to assess the expression of genes associated with human articular chondrocyte homeostasis. A spontaneously occurring OA model in guinea pigs was used to investigate the effect of EGCG in vivo. OA severity was evaluated using Safranin O staining and Osteoarthritis Research Society International (OARSI) scores, as well as by immunohistochemical (IHC) analysis to determine the protein level of type II collagen (Col II), matrix metalloproteinase 13 (MMP-13), and p16 ink4a in articular cartilage. In the in-vitro study, EGCG increased the gene expression of aggrecan and Col II and decreased the expression of interleukin-1, cyclooxygenase 2, MMP-13, alkaline phosphatase, Col X, and p16 Ink4a; EGCG treatment also attenuated the degraded cartilage with a lower OARSI score. Meanwhile, IHC results showed that EGCG exerted an anti-OA effect by reducing ECM degradation, cartilage inflammation, and cell senescence with a less-immunostained Col II, MMP-13, and p16 Ink4a. In conclusion, these findings suggest that EGCG may be a potential disease-modifying OA drug for the treatment of primary OA.

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The purpose of this paper was to investigate the silicon wafer surface roughness ground by the micro pellet grinding tool and the electroplated disc grinding tool with diamond grit size of 4-6 μm and 10-20μm under the spindle rotation speed of 500-2500 rpm and the feed rate of 1-5 μm/min. The results showed that the micro pellet grinding tool can get a better surface roughness of the silicon wafer than the electroplated disc tool. When the tools containing a larger diamond grit were employed, selecting a higher spindle rotation speed and a lower feed rate can obtain a better wafer roughness. However, when the tools of a smaller diamond grit were used, the spindle rotaion speed operates properly at a optimal value to obtain a best wafer surface roughness, which achieves Ra = 0.03-0.06 μm for the micro pellet tool. Besides, the material removal mechanism during the grinding silicon wafer for these two tools displayed mainly ductile grinding behavior.

This research uses Ink‐jet printer process to fabricate microlens on the bottom of a LGP in a fast and cost‐effective way. Compared with typical dot printing method, Ink‐jet printing is able to save 50% material consumption. In addition, the microlens with UV‐curable epoxy could be well controlled in the radius, contact angle and arbitrary arrangement. A 20×20cm2 LGP can be fabricated with desired microlens pattern within 10 seconds, which exhibits a potential to apply ink‐jet process upon the high‐speed mass production.