Microcracks, spall and fracture in glass : A study using short pulsed laser shock waves

Copyright 1998 American Institute of Physics. This article may be downloaded for personal use only. Any other use requires prior permission of the author and the American Institute of Physics. The following article appeared in Journal of Applied Physics, 83(7), 3583-3594, 1998 and may be found at http://dx.doi.org/10.1063/1.36657

MicroRNA-223 Delivered by Platelet-Derived Microvesicles Promotes Lung Cancer Cell Invasion via Targeting Tumor Suppressor EPB41L3

Background: Patients with hematogenous metastatic lung cancer displayed significantly increased platelet count and aggregation compared to lung cancer patients without hematogenous metastasis. The mechanism underlying the correlation between the lung cancer hematogenous metastasis and platelet activation remains unknown. Results: In the present study, we explored the role of microRNA-223 (miR-223) derived from platelets in modulating lung cancer cell invasion. Our results demonstrated that platelets from NSCLC patients contain higher level of miR-223 than that from healthy subjects. The concentration of miR-223 in the platelet-secreted microvesicles (P-MVs) from NSCLC patients was also increased compared to that from healthy subjects. Incubation of human lung cancer A549 cells with P-MVs resulted in rapid delivery of miR-223 into A549 cells, in which platelet miR-223 targeted EPB41L3 and thus promoted A549 cell invasion. The effect of P-MVs on reducing EPB41L3 in A549 cells but promoting tumor cell invasion could be largely abolished by depletion of miR-223 via transfection with miR-223 antagomir. The role of EPB41L3 in inhibiting A549 cell invasion was further validated by directly downregulating EPB41L3 via transfecting cells with EPB41L3 siRNA or miR-223 mimic. Conclusions: Our study demonstrates for the first time that platelet-secreted miR-223 via P-MVs can promote lung cancer cell invasion via targeting tumor suppressor EPB41L3

Pancreatic β cells control glucose homeostasis via the secretion of exosomal miR-29 family.

Secreted microRNAs (miRNAs) are novel endocrine factors that play essential pathological and physiological roles. Here, we report that pancreatic β cell-released exosomal miR-29 family members (miR-29s) regulate hepatic insulin sensitivity and control glucose homeostasis. Cultured pancreatic islets were shown to secrete miR-29s in response to high levels of free fatty acids (FFAs) in vitro. In vivo, high levels of FFAs, promoted by either high-fat diet (HFD) feeding (physiopathological) or fasting (physiological), increased the secretion of miR-29s into plasma. Intravenous administration of exosomal miR-29s attenuated insulin sensitivity. The overexpression of miR-29s in the β cells of transgenic (TG) mice promoted the secretion of miR-29s and inhibited the insulin-mediated suppression of glucose output in the liver. We used selective overexpression of traceable heterogenous mutant miR-29s in β cells to confirm that islet-derived exosomal miR-29s target insulin signalling in the liver and blunt hepatic insulin sensitivity. Moreover, in vivo disruption of miR-29s expression in β cells reversed HFD-induced insulin resistance. In vitro experiments demonstrated that isolated exosomes enriched in miR-29s inhibited insulin signalling in the liver and increased hepatic glucose production. These results unveil a novel β cell-derived secretory signal-exosomal miR-29s-and provide insight into the roles of miR-29s in manipulating glucose homeostasis.MRC MD

Crown ether decorated silicon photonics for safeguarding against lead poisoning

Lead (Pb2+) toxification in society is one of the most concerning public health crisis that remains unaddressed. The exposure to Pb2+ poisoning leads to a multitude of enduring health issues, even at the part-per-billion scale (ppb). Yet, public action dwarfs its impact. Pb2+ poisoning is estimated to account for 1 million deaths per year globally, which is in addition to its chronic impact on children. With their ring-shaped cavities, crown ethers are uniquely capable of selectively binding to specific ions. In this work, for the first time, the synergistic integration of highly-scalable silicon photonics, with crown ether amine conjugation via Fischer esterification in an environmentally-friendly fashion is demonstrated. This realises a photonic platform that enables the in-situ, highly-selective and quantitative detection of various ions. The development dispels the existing notion that Fischer esterification is restricted to organic compounds, laying the ground for subsequent amine conjugation for various crown ethers. In this work, the platform is engineered for Pb2+ detection, demonstrating a large dynamic detection range of 1 - 262000 ppb with high selectivity against a wide range of relevant ions. These results indicate the potential for the pervasive implementation of the technology to safeguard against ubiquitous lead poisoning in our society

P3HT-Based Solar Cells: Structural Properties and Photovoltaic Performance

Each year we are bombarded with B.Sc. and Ph.D. applications from students that want to improve the world. They have learned that their future depends on changing the type of fuel we use and that solar energy is our future. The hope and energy of these young people will transform future energy technologies, but it will not happen quickly. Organic photovoltaic devices are easy to sketch, but the materials, processing steps, and ways of measuring the properties of the materials are very complicated. It is not trivial to make a systematic measurement that will change the way other research groups think or practice. In approaching this chapter, we thought about what a new researcher would need to know about organic photovoltaic devices and materials in order to have a good start in the subject. Then, we simplified that to focus on what a new researcher would need to know about poly-3-hexylthiophene:phenyl-C61-butyric acid methyl ester blends (P3HT: PCBM) to make research progress with these materials. This chapter is by no means authoritative or a compendium of all things on P3HT:PCBM. We have selected to explain how the sample fabrication techniques lead to control of morphology and structural features and how these morphological features have specific optical and electronic consequences for organic photovoltaic device applications

Cr(VI) reduction at rutile-catalyzed cathode in microbial fuel cells

Cathodic reduction of hexavalent chromium (Cr(VI)) and simultaneous power generation were successfully achieved in a microbial fuel cell (MFC) containing a novel rutile-coated cathode. The selected rutile was previously characterized to be sensitive to visible light and capable of both non-photo- and photocatalysis. In the MFCs containing rutile-coated cathode, Cr(VI) was rapidly reduced in the cathode chamber in presence and absence of light irradiation; and the rate of Cr(VI) reduction under light irradiation was substantially higher than that in the dark. Under light irradiation, 97% of Cr(VI) (initial concentration 26 mg/L) was reduced within 26 h, which was 1.6× faster than that in the dark controls in which only background non-photocatalysis occurred. The maximal potential generated under light irradiation was 0.80 vs. 0.55 V in the dark controls. These results indicate that photocatalysis at the rutile-coated cathode in the MFCs might have lowered the cathodic overpotential, and enhanced electron transfer from the cathode to Cr(VI) for its reduction. In addition, photoexcited electrons generated during the cathode photocatalysis might also have contributed to the higher Cr(VI) reduction rates when under light irradiation. This work assessed natural rutile as a novel cathodic catalyst for MFCs in power generation; particularly it extended the practical merits of conventional MFCs to cathodic reduction of environmental contaminants such as Cr(VI). Keywords: Cr(VI), Hexavalent chromium, Microbial fuel cell, MFC, Rutile, Semiconducto