383 research outputs found
Ultrasensitive UV-tunable grating in all-solid photonic bandgap fibers
We study the shift of a long period grating's resonance wavelength with UV induced refractive index changes in an all-solid photonic bandgap fiber. A long period grating is mechanically imprinted in an all-solid photonic bandgap fiber with Germanium doped silica high-index rods in a lower-index silica background. The index of the high-index rods is modified through UV exposure, and we observe that the long period grating's resonance shifts with the bandgaps. With a sensitivity of 21,000 nanometers per refractive index unit and a 8.8 nm resonance width changes of refractive index of 3 x 10(-6) are in principle detectable Crown Copyrigh
Towards the understanding of microRNA and environmental factor interactions and their relationships to human diseases
Increasing studies have shown that the interactions between microRNAs (miRNAs) and environmental factors (EFs) play critical roles in determining phenotypes and diseases. In this study, we revealed a number of important biological insights by analyzing and modeling of miRNA-EF interactions and their relationships with human diseases. We demonstrated that the miRNA signatures of EFs could provide new information on EFs. More importantly, we quantitatively showed that the miRNA signatures of drug/radiation could be used as indicators for evaluating the results of cancer treatments. Finally, we developed a computational model that could efficiently identify the possible relationship between EF and human diseases. Meanwhile, we provided a website (http://cmbi.hsc.pku.edu.cn/miren) for the main results of this study. This study elucidates the mechanisms of EFs, presents a framework for predicting the results of cancer treatments, and develops a model that illustrates the relationships between EFs and human diseases
Performance of the CMS Cathode Strip Chambers with Cosmic Rays
The Cathode Strip Chambers (CSCs) constitute the primary muon tracking device
in the CMS endcaps. Their performance has been evaluated using data taken
during a cosmic ray run in fall 2008. Measured noise levels are low, with the
number of noisy channels well below 1%. Coordinate resolution was measured for
all types of chambers, and fall in the range 47 microns to 243 microns. The
efficiencies for local charged track triggers, for hit and for segments
reconstruction were measured, and are above 99%. The timing resolution per
layer is approximately 5 ns
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Nucleotide excision repair is a potential therapeutic target in multiple myeloma
Despite the development of novel drugs, alkylating agents remain an important component of therapy in multiple myeloma (MM). DNA repair processes contribute towards sensitivity to alkylating agents and therefore we here evaluate the role of nucleotide excision repair (NER), which is involved in the removal of bulky adducts and DNA crosslinks in MM. We first evaluated NER activity using a novel functional assay and observed a heterogeneous NER efficiency in MM cell lines and patient samples. Using next-generation sequencing data, we identified that expression of the canonical NER gene, excision repair cross-complementation group 3 (ERCC3), significantly impacted the outcome in newly diagnosed MM patients treated with alkylating agents. Next, using small RNA interference, stable knockdown and overexpression, and small-molecule inhibitors targeting xeroderma pigmentosum complementation group B (XPB), the DNA helicase encoded by ERCC3, we demonstrate that NER inhibition significantly increases sensitivity and overcomes resistance to alkylating agents in MM. Moreover, inhibiting XPB leads to the dual inhibition of NER and transcription and is particularly efficient in myeloma cells. Altogether, we show that NER impacts alkylating agents sensitivity in myeloma cells and identify ERCC3 as a potential therapeutic target in MM
Ex Vivo Activity of Cardiac Glycosides in Acute Leukaemia
BACKGROUND: Despite years of interest in the anti-cancerous effects of cardiac glycosides (CGs), and numerous studies in vitro and in animals, it has not yet been possible to utilize this potential clinically. Reports have demonstrated promising in vitro effects on different targets as well as a possible therapeutic index/selectivity in vitro and in experimental animals. Recently, however, general inhibition of protein synthesis was suggested as the main mechanism of the anti-cancerous effects of CGs. In addition, evidence of species differences of a magnitude sufficient to explain the results of many studies called for reconsideration of earlier results. PRINCIPAL FINDINGS: In this report we identified primary B-precursor and T-ALL cells as being particularly susceptible to the cytotoxic effects of CGs. Digitoxin appeared most potent and IC(50) values for several patient samples were at concentrations that may be achieved in the clinic. Significant protein synthesis inhibition at concentrations corresponding to IC(50) was demonstrated in colorectal tumour cell lines moderately resistant to the cytotoxic effects of digoxin and digitoxin, but not in highly sensitive leukaemia cell lines. CONCLUSION: It is suggested that further investigation regarding CGs may be focused on diagnoses like T- and B-precursor ALL
Performance and Operation of the CMS Electromagnetic Calorimeter
The operation and general performance of the CMS electromagnetic calorimeter
using cosmic-ray muons are described. These muons were recorded after the
closure of the CMS detector in late 2008. The calorimeter is made of lead
tungstate crystals and the overall status of the 75848 channels corresponding
to the barrel and endcap detectors is reported. The stability of crucial
operational parameters, such as high voltage, temperature and electronic noise,
is summarised and the performance of the light monitoring system is presented
Blechnum Orientale Linn - a fern with potential as antioxidant, anticancer and antibacterial agent
<p>Abstract</p> <p>Background</p> <p><it>Blechnum orientale </it>Linn. (<it>Blechnaceae</it>) is used ethnomedicinally for the treatment of various skin diseases, stomach pain, urinary bladder complaints and sterilization of women. The aim of the study was to evaluate antioxidant, anticancer and antibacterial activity of five solvent fractions obtained from the methanol extract of the leaves of <it>Blechnum orientale </it>Linn.</p> <p>Methods</p> <p>Five solvent fractions were obtained from the methanol extract of <it>B. orientale</it> through successive partitioning with petroleum ether, chloroform, ethyl acetate, butanol and water. Total phenolic content was assessed using Folin-Ciocalteu's method. The antioxidant activity was determined by measuring the scavenging activity of DPPH radicals. Cytotoxic activity was tested against four cancer cell lines and a non-malignant cell using MTT assay. Antibacterial activity was assessed using the disc diffusion and broth microdilution assays. Standard phytochemical screening tests for saponins, tannins, terpenoids, flavonoids and alkaloids were also conducted.</p> <p>Results</p> <p>The ethyl acetate, butanol and water fractions possessed strong radical scavenging activity (IC<sub>50 </sub>8.6-13.0 μg/ml) and cytotoxic activity towards human colon cancer cell HT-29 (IC<sub>50 </sub>27.5-42.8 μg/ml). The three extracts were also effective against all Gram-positive bacteria tested: <it>Bacillus cereus, Micrococcus luteus</it>, methicillin-susceptible <it>Staphylococcus aureus </it>(MSSA), methicillin-resistant <it>Staphylococcus aureus </it>(MRSA) and <it>Stapylococcus epidermidis</it>(minimum inhibitory concentration MIC 15.6-250 μg/ml; minimum bactericidal concentration MBC 15.6-250 μg/ml). Phytochemical analysis revealed the presence of flavonoids, terpenoids and tannins. Ethyl acetate and butanol fractions showed highest total phenolic content (675-804 mg gallic acid equivalent/g).</p> <p>Conclusions</p> <p>The results indicate that this fern is a potential candidate to be used as an antioxidant agent, for colon cancer therapy and for treatment of MRSA infections and other MSSA/Gram-positive bacterial infectious diseases.</p
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