Dalian University of Technology

About: Dalian University of Technology is a education organization based out in Dalian, China. It is known for research contribution in the topics: Catalysis & Finite element method. The organization has 60890 authors who have published 71921 publications receiving 1188356 citations. The organization is also known as: Dàlián Lǐgōng Dàxué.

Postglacial recolonization and cpDNA variation of silver birch, Betula pendula.

Abstract: Chloroplast PCR-RFLP markers were used to reconstruct the history of the silver birch, Betula pendula Roth, in Europe since the last glacial maximum (LGM). In birch, fossil pollen maps do not reveal a clear chronological sequence of postglacial spread. If anything, the pollen record suggests that most of Europe was recolonized by birches as early as 10000 bp, probably from populations that remained close to the ice sheets during the LGM. The geographical distribution of haplotypes supports a scenario of early colonization. Two of the 13 haplotypes that were observed are common, representing 35% and 49% of the total sample, respectively. Although one of the common haplotypes is predominant in the NW and the other in the SE, both are present throughout most of the investigated geographical area. Rare haplotypes are geographically restricted. The distribution of the haplotypes reveals five genetic boundaries between groups of haplotypes and allows us to infer patterns of postglacial recolonization. Europe was re-occupied by two main waves of recolonization: one eastern and one western, with origins at intermediate latitudes. Populations in the Iberian Peninsula and in Italy did not take part in the postglacial recolonization of Europe.

Visualizing Carrier Diffusion in Individual Single-Crystal Organolead Halide Perovskite Nanowires and Nanoplates

Abstract: Single-crystal CH3NH3PbX3 (X = I–, Cl–, Br–) perovskite nanowires (NWs) and nanoplates (NPs), which demonstrate ultracompact sizes and exceptional photophysical properties, offer promises for applications in nanoscale photonics and optoelectronics. However, traditional electronic and transient techniques are limited by the dimensions of the samples, and characterizations of the carrier behavior (diffusion coefficient, charge mobility and diffusion length) in these NWs and NPs are extremely difficult. Herein, we report the direct visualization of the carrier diffusion process in individual single-crystal CH3NH3PbI3 and CH3NH3PbBr3 NWs and NPs using time-resolved and photoluminescence-scanned imaging microscopy. We report the diffusion coefficient (charge motility), which varies significantly between different NWs and NPs, ranging from 1.59 to 2.41 cm2 s–1 (56.4 to 93.9 cm2 V–1 s–1) for CH3NH3PbI3 and 0.50 to 1.44 cm2 s–1 (19.4 to 56.1 cm2 V–1 s–1) for CH3NH3PbBr3 and find this variation is independent of t...

Perfectly Alternating Copolymerization of CO2 and Epichlorohydrin Using Cobalt(III)-Based Catalyst Systems

Abstract: Selective transformations of carbon dioxide and epoxides into biodegradable polycarbonates by the alternating copolymerization of the two monomers represent some of the most well-studied and innovative technologies for potential large-scale utilization of carbon dioxide in chemical synthesis. For the most part, previous studies of these processes have focused on the use of aliphatic terminal epoxides or cyclohexene oxide derivatives, with only rare reports concerning the synthesis of CO2 copolymers from epoxides containing electron-withdrawing groups such as styrene oxide. Herein we report the production of the CO2 copolymer with more than 99% carbonate linkages from the coupling of CO2 with epichlorohydrin, employing binary and bifunctional (salen)cobalt(III)-based catalyst systems. Comparative kinetic studies were performed via in situ infrared measurements as a function of temperature to assess the activation barriers for the production of cyclic carbonate versus copolymer involving two electronically ...

Epigenetic therapy inhibits metastases by disrupting premetastatic niches

Abstract: Cancer recurrence after surgery remains an unresolved clinical problem1–3. Myeloid cells derived from bone marrow contribute to the formation of the premetastatic microenvironment, which is required for disseminating tumour cells to engraft distant sites4–6. There are currently no effective interventions that prevent the formation of the premetastatic microenvironment6,7. Here we show that, after surgical removal of primary lung, breast and oesophageal cancers, low-dose adjuvant epigenetic therapy disrupts the premetastatic microenvironment and inhibits both the formation and growth of lung metastases through its selective effect on myeloid-derived suppressor cells (MDSCs). In mouse models of pulmonary metastases, MDSCs are key factors in the formation of the premetastatic microenvironment after resection of primary tumours. Adjuvant epigenetic therapy that uses low-dose DNA methyltransferase and histone deacetylase inhibitors, 5-azacytidine and entinostat, disrupts the premetastatic niche by inhibiting the trafficking of MDSCs through the downregulation of CCR2 and CXCR2, and by promoting MDSC differentiation into a more-interstitial macrophage-like phenotype. A decreased accumulation of MDSCs in the premetastatic lung produces longer periods of disease-free survival and increased overall survival, compared with chemotherapy. Our data demonstrate that, even after removal of the primary tumour, MDSCs contribute to the development of premetastatic niches and settlement of residual tumour cells. A combination of low-dose adjuvant epigenetic modifiers that disrupts this premetastatic microenvironment and inhibits metastases may permit an adjuvant approach to cancer therapy. In mouse models of pulmonary metastasis, adjuvant epigenetic therapy targeting myeloid-derived suppressor cells disrupts the premetastatic microenvironment after resection of primary tumours and inhibits the dissemination of residual tumour cells.

Efficient Electrocatalytic Water Oxidation by a Copper Oxide Thin Film in Borate Buffer

Abstract: A robust water oxidation catalyst based on copper oxide was prepared by facile electrodeposition of Cu2+ from borate buffer solution under near neutral conditions. The Cu–Bi thin film exhibits high activity and long-term stability in Cu2+-free pH 9 borate buffer. A steady current density of 1.2 mA/cm2 was sustained for at least 10 h at 1.3 V versus NHE without iR compensation, which sets a new benchmark for copper-based OEC.