High-power linearly-polarized single-frequency thulium-doped fiber Master-Oscillator Power-Amplifier

We report a high power narrow-linewidth source at approximately 2 microm based on a Tm-doped fiber distributed-feedback master-oscillator and three Tm fiber amplifier stages. The master-oscillator and first two amplifier stages were in-band pumped by Er,Yb fiber lasers operating at 1565 nm, and the final stage amplifier was cladding-pumped at 795 nm by two spatially-combined diode-stacks. The MOPA yielded 100 W of single frequency output at 1943 nm with a beam propagation factor (M(2)) of 1.25 and with a polarization extinction ratio of >94%. The output power was limited by thermally-induced damage in the final amplifier stage. The prospects for further power scaling are considered.

The electrochemical reduction of fullerenes, C60 and C70

The hexaanion of fullerene, C(60)(6-), was obtained in 1:5 (v/v) acetonitrile-toluene mixture with a mercury hemispherical ultramicroelectrode as a working electrode at a temperature of up to 30 degrees C. The C(70)(6-) ion also can be observed under the same conditions. The differences between the redox potentials of C(60) relative to C(70) indicate that it is easier to add electrons to C(70) and its anions compared to the counterparts of C(60). The results show that the mercury electrode is very suitable for investigation of the properties of the electrochemical reduction for the fullerenes, particularly C(60), at room temperature.

Immunomodulated signaling in macrophages: Studies on activation of Raf-1, MAPK, cPLA(2) and secretion of IL-12

Little is known about the mechanism and signal transduction by LPS-mediated immunomodulation of murine peritoneal macrophages. It is found that the signal molecules of the down-stream of Ras, Raf-1, MAPK p44, and MAPK p42 are phosphorylated, and cPLA(2) is activated with a significant increase of the release of [ H(3) ] AA by macrophages in response to LPS and PMA. Compared with the very recent finding that LPS and PMA trigger the activation and translocation of PKC-alpha and PKC-epsilon, these findings suggest that there is a connection between PKC signaling pathway and the Raf-1/MAPK pathway and that the activation of these main signaling events may be closely related to the secretion of IL-12 during LPS-induced modulation of macrophages.

Raman spectroscopic characteristics of microcosmic and photosensitive damage on space structure of liposomes sensitized by hypocrellin and its derivatives

Raman spect-pic characteristics of microcosmic and photosensitive damage on space structure of DP-PC liposomes sensitized by hypocrellin and its derivatives are obvious. The trans conformation decreased and the gauche conformation increased. The longitudinal order-parameter in chains and the lateral order-parameter between chains decreased in different degrees. The lateral packing became loose. Photodamage on the liposomes sensitized by 5-Br-hypocrellin B was stronger than that by hypocrellins A and B.

The sequence and de novo assembly of the giant panda genome

Using next-generation sequencing technology alone, we have successfully generated and assembled a draft sequence of the giant panda genome. The assembled contigs (2.25 gigabases (Gb)) cover approximately 94% of the whole genome, and the remaining gaps (0.05 Gb) seem to contain carnivore-specific repeats and tandem repeats. Comparisons with the dog and human showed that the panda genome has a lower divergence rate. The assessment of panda genes potentially underlying some of its unique traits indicated that its bamboo diet might be more dependent on its gut microbiome than its own genetic composition. We also identified more than 2.7 million heterozygous single nucleotide polymorphisms in the diploid genome. Our data and analyses provide a foundation for promoting mammalian genetic research, and demonstrate the feasibility for using next-generation sequencing technologies for accurate, cost-effective and rapid de novo assembly of large eukaryotic genomes.

PhosSNP for systematic analysis of genetic polymorphisms that influence protein phosphorylation

We are entering the era of personalized genomics as breakthroughs in sequencing technology have made it possible to sequence or genotype an individual person in an efficient and accurate manner. Preliminary results from HapMap and other similar projects have revealed the existence of tremendous genetic variations among world populations and among individuals. It is important to delineate the functional implication of such variations, i.e. whether they affect the stability and biochemical properties of proteins. It is also generally believed that the genetic variation is the main cause for different susceptibility to certain diseases or different response to therapeutic treatments. Understanding genetic variation in the context of human diseases thus holds the promise for "personalized medicine." In this work, we carried out a genome-wide analysis of single nucleotide polymorphisms (SNPs) that could potentially influence protein phosphorylation characteristics in human. Here, we defined a phosphorylation-related SNP (phosSNP) as a non-synonymous SNP (nsSNP) that affects the protein phosphorylation status. Using an in-house developed kinase-specific phosphorylation site predictor (GPS 2.0), we computationally detected that approximately 70% of the reported nsSNPs are potential phosSNPs. More interestingly, approximately 74.6% of these potential phosSNPs might also induce changes in protein kinase types in adjacent phosphorylation sites rather than creating or removing phosphorylation sites directly. Taken together, we proposed that a large proportion of the nsSNPs might affect protein phosphorylation characteristics and play important roles in rewiring biological pathways. Finally, all phosSNPs were integrated into the PhosSNP 1.0 database, which was implemented in JAVA 1.5 (J2SE 5.0). The PhosSNP 1.0 database is freely available for academic researchers.

Manipulating nanoscale light fields with the asymmetric bowtie nano-colorsorter

We present a class of devices called Asymmetric Bowtie nano-Colorsorters. These devices are specifically engineered to not only capture and confine optical fields, but also to spectrally filter and steer them while maintaining nanoscale field distributions. We show that spectral properties and localized spatial mode distributions can be readily tuned by controlled asymmetry. Nano-Colorsorters can control light's spatial and spectral distributions at the nanoscale and thus significantly impact applications ranging from broadband light harvesting to ultrafast wavelength-selective photodetection.

Relationship between NFKB1 -94 insertion/deletion ATTG polymorphism and susceptibility of cervical squamous cell carcinoma risk

BACKGROUND

A very high expression of nuclear factor-kappa B protein (nuclear p50, encoded by NFKB1) in high-grade squamous intraepithelial lesion and invasive cancers has been observed. The aim of this study was to determine whether the functional NFKB1 -94 insertion/deletion ATTG polymorphism (rs28362491) is associated with cervical squamous cell carcinoma (CSCC).

MATERIALS AND METHODS

PCR-polyacrylamide gel electrophoresis method was used to genotype the NFKB1 -94 insertion/deletion ATTG polymorphism in 233 women with CSCC and 365 ethnicity-matched healthy control women. The genotyping method was confirmed by the DNA sequencing analysis.

RESULTS

The frequency of ATTG(2)/ATTG(2) genotype and ATTG(2) allele in the CSCC patients was significantly higher than that of controls, indicating that the -94 insertion/deletion ATTG polymorphism in NFKB1 promoter was associated with CSCC [P = 0.001, odds ratio (OR) = 2.560, 95% confidence interval (CI) 1.459-4.492 and P = 0.001, OR = 1.493, 95% CI 1.168-1.908, respectively]. Results of stratified analyses revealed that this polymorphism is associated with younger age (< or =35 years) and positive parametrial invasion but not with tumor differentiation, high clinical stage or lymph node status.

CONCLUSION

Our results indicate that the functional NFKB1 -94 insertion/deletion ATTG polymorphism is associated with CSCC, especially with younger age (< or =35 years) and positive parametrial invasion of CSCC patients.