558 research outputs found

    Moving Stationary State of Exciton-Phonon Condensate in Cu2O

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    We explore a simple theoretical model to describe the properties of Bose condensed para-excitons in Cu2O. Taking into account the exciton-phonon interaction and introducing a coherent phonon part of the moving condensate, we derive the dynamic equations for the exciton-phonon condensate. Within the Bose approximation for excitons, we discuss the conditions for the moving inhomogeneous condensate to appear in the crystal. We calculate the condensate wave function and energy and a collective excitation spectrum in the semiclassical approximation. The stability conditions of the moving condensate are analyzed by use of Landau arguments, and two critical velocities appear in the theory. Finally, we apply our model to describe the recently observed interference between two coherent exciton-phonon packets in Cu2O.Comment: 20 pages (LaTeX), one figure (.ps) incorporated by epsf. Submitted to Phys. Stat. Sol (B

    Wavelength-multiplexed duplex transceiver based on III-V/Si hybrid integration for off-chip and on-chip optical interconnects

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    A six-channel wavelength-division-multiplexed optical transceiver with a compact footprint of 1.5 x 0.65 mm(2) for off-chip and on-chip interconnects is demonstrated on a single silicon-on-insulator chip. An arrayed waveguide grating is used as the (de)multiplexer, and III-V electroabsorption sections fabricated by hybrid integration technology are used as both modulators and detectors, which also enable duplex links. The 30-Gb/s capacity for each of the six wavelength channels for the off-chip transceiver is demonstrated. For the on-chip interconnect, an electrical-to-electrical 3-dB bandwidth of 13 GHz and a data rate of 30 Gb/s per wavelength are achieved

    Key nodes of a microRNA network associated with the integrated mesenchymal subtype of high-grade serous ovarian cancer

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    Metastasis is the main cause of cancer mortality. One of the initiating events of cancer metastasis of epithelial tumors is epithelial-to-mesenchymal transition (EMT), during which cells dedifferentiate from a relatively rigid cell structure/morphology to a flexible and changeable structure/morphology often associated with mesenchymal cells. The presence of EMT in human epithelial tumors is reflected by the increased expression of genes and levels of proteins that are preferentially present in mesenchymal cells. The combined presence of these genes forms the basis of mesenchymal gene signatures, which are the foundation for classifying a mesenchymal subtype of tumors. Indeed, tumor classification schemes that use clustering analysis of large genomic characterizations, like The Cancer Genome Atlas (TCGA), have defined mesenchymal subtype in a number of cancer types, such as high-grade serous ovarian cancer and glioblastoma. However, recent analyses have shown that gene expression-based classifications of mesenchymal subtypes often do not associate with poor survival. This “paradox” can be ameliorated using integrated analysis that combines multiple data types. We recently found that integrating mRNA and microRNA (miRNA) data revealed an integrated mesenchymal subtype that is consistently associated with poor survival in multiple cohorts of patients with serous ovarian cancer. This network consists of 8 major miRNAs and 214 mRNAs. Among the 8 miRNAs, 4 are known to be regulators of EMT. This review provides a summary of these 8 miRNAs, which were associated with the integrated mesenchymal subtype of serous ovarian cancer

    Determination of the number of J/ψ events with J/ψ → inclusive decays

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    Research Progress of Baihe Gujin Decoction in the Treatment of Lung Cancer

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    Shi-hao Zhao,1 Wen-hui Wang,1 Yu-cong Liang,1 Kai-xin Zhang,1 Kuan Chen,1 Hong-ling Wang,2 Xiang-qi Wang2 1Acupuncture and Moxibustion Massage College, Henan University of Traditional Chinese Medicine, Zhengzhou, Henan, 450046, People’s Republic of China; 2Department of Oncology, Third Affiliated Hospital of Henan University of Traditional Chinese Medicine, Zhengzhou, Henan, 450008, People’s Republic of ChinaCorrespondence: Xiang-qi Wang, Email [email protected]: Baihe Gujin decoction is one of the most commonly used decoction in traditional Chinese medicine for the treatment of lung cancer. It can nourish yin and moisten the lung as well as prevent phlegm from forming and stop coughing. On the one hand, Baihe Gujin decoction is characterized with extensive application, proven efficacy, a long history, and high safety. On the other hand, Baihe Gujin decoction can induce apoptosis of tumor cells, improve immune function and inhibit inflammation. The main anti-tumor components of this include kaempferol, quercetin, isorhamnetin, glycyrrhizin and β-sitosterol. Clinically, Baihe Gujin decoction can improve the adverse reactions caused by radiotherapy, chemotherapy and immunotherapy for lung cancer, enhance the quality of life of patients, and prolong their survival time. At present, there are a large number of clinical and basic researches on the treatment of lung cancer with Baihe Gujin decoction. In this paper, we mainly discussed the treatment of lung cancer with Baihe Gujin decoction through analyzing basic and clinical researches at home and abroad in the past 20 years. Through the discussion, we aimed to probe deeper into Baihe Gujin decoction for the treatment of lung cancer, thereby providing a broader idea for clinical diagnosis and treatment of lung cancer.Keywords: Baihe Gujin decoction, lung cancer, traditional Chinese medicine, basic research, clinical stud

    Improvements and Applications of AMS Radiocarbon Measurement at Peking University

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    AMS radiocarbon measurements were started at Peking University in 1992 with a modified HICONEX 834 ion source. Some archaeological samples were measured at a sensitivity of 10(-14) with ca. 1.7% precision for modern samples. We have made many improvements in our first two years of operation: a high-intensity Cs sputtering ion source was installed; the graphite sample preparation technique was investigated; and the system stability has been improved. The blank sample background is currently ca. 0.006 MC and a precision within 1% can be reached for modern samples. Geological, archaeological, environmental and biomedical samples can be measured routinely. We present some typical applications.Geochemistry & GeophysicsSCI(E)

    Two-photon widths of the χ c0,2 states and helicity analysis for χ c2→γγ

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    Based on a data sample of 106×106 ψ ′ events collected with the BESIII detector, the decays ψ ′→γχ c0,2, χ c0,2→γγ are studied to determine the two-photon widths of the χ c0,2 states. The two-photon decay branching fractions are determined to be B(χ c0→γγ)=(2. 24±0.19±0.12±0.08)×10 -4 and B(χ c2→γγ)=(3.21±0.18±0. 17±0.13)×10 -4. From these, the two-photon widths are determined to be Γ γγ(χ c0)=(2. 33±0.20±0.13±0.17)keV, Γ γγ(χ c2)=(0.63±0.04±0. 04±0.04)keV, and R=Γ γγ(χ c2)/ Γ γγ(χ c0)=0.271±0. 029±0.013±0.027, where the uncertainties are statistical, systematic, and those from the PDG B(ψ ′→γχ c0,2) and Γ(χ c0,2) errors, respectively. The ratio of the two-photon widths for helicity λ=0 and helicity λ=2 components in the decay χ c2→γγ is measured for the first time to be f 0/2=Γγγλ= 0(χ c2)/Γγγλ=2(χ c2)=0. 00±0.02±0.02. © 2012 American Physical Society.published_or_final_versio

    Comparative transcriptome sequencing of germline and somatic tissues of the Ascaris suum gonad

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    <p>Abstract</p> <p>Background</p> <p><it>Ascaris suum </it>(large roundworm of pigs) is a parasitic nematode that causes substantial losses to the meat industry. This nematode is suitable for biochemical studies because, unlike <it>C. elegans</it>, homogeneous tissue samples can be obtained by dissection. It has large sperm, produced in great numbers that permit biochemical studies of sperm motility. Widespread study of <it>A. suum </it>would be facilitated by more comprehensive genome resources and, to this end, we have produced a gonad transcriptome of <it>A. suum</it>.</p> <p>Results</p> <p>Two 454 pyrosequencing runs generated 572,982 and 588,651 reads for germline (TES) and somatic (VAS) tissues of the <it>A. suum </it>gonad, respectively. 86% of the high-quality (HQ) reads were assembled into 9,955 contigs and 69,791 HQ reads remained as singletons. 2.4 million bp of unique sequences were obtained with a coverage that reached 16.1-fold. 4,877 contigs and 14,339 singletons were annotated according to the <it>C. elegans </it>protein and the Kyoto Encyclopedia of Genes and Genomes (KEGG) protein databases. Comparison of TES and VAS transcriptomes demonstrated that genes participating in DNA replication, RNA transcription and ubiquitin-proteasome pathways are expressed at significantly higher levels in TES tissues than in VAS tissues. Comparison of the <it>A. suum </it>TES transcriptome with the <it>C. elegans </it>microarray dataset identified 165 <it>A. suum </it>germline-enriched genes (83% are spermatogenesis-enriched). Many of these genes encode serine/threonine kinases and phosphatases (KPs) as well as tyrosine KPs. Immunoblot analysis further suggested a critical role of phosphorylation in both testis development and spermatogenesis. A total of 2,681 <it>A. suum </it>genes were identified to have associated RNAi phenotypes in <it>C. elegans</it>, the majority of which display embryonic lethality, slow growth, larval arrest or sterility.</p> <p>Conclusions</p> <p>Using deep sequencing technology, this study has produced a gonad transcriptome of <it>A. suum</it>. By comparison with <it>C. elegans </it>datasets, we identified sets of genes associated with spermatogenesis and gonad development in <it>A. suum</it>. The newly identified genes encoding KPs may help determine signaling pathways that operate during spermatogenesis. A large portion of <it>A. suum </it>gonadal genes have related RNAi phenotypes in <it>C. elegans </it>and, thus, might be RNAi targets for parasite control.</p
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