9,068 research outputs found
Firm R&D, Absorptive Capacity and Learning by Exporting: Firm-level Evidence from China
No full textThe absorptive capacity of firms developed through R&D promotes learning by exporting. In this paper, we estimate the instantaneous and long-run productivity effects of exporting on the universe of Chinese manufacturing firms. We find that exporting has very different productivity effects for firms with different pre-export R&D status. It has large and lasting productivity effects for firms with pre-export R&D, while it has little effects for firms without pre-export R&D. Furthermore, the effect of exporting increases with the number of years of pre-export R&D investment.Business, FinanceEconomicsInternational RelationsSSCI0ARTICLE91131-11453
AMPylation of Rho GTPases Subverts Multiple Host Signaling Processes
No full textabstract: Rho GTPases are frequent targets of virulence factors as they are keystone signaling molecules. Herein, we demonstrate that AMPylation of Rho GTPases by VopS is a multifaceted virulence mechanism that counters several host immunity strategies. Activation of NFκB, Erk, and JNK kinase signaling pathways were inhibited in a VopS-dependent manner during infection with Vibrio parahaemolyticus. Phosphorylation and degradation of IKBα were inhibited in the presence of VopS as was nuclear translocation of the NFκB subunit p65. AMPylation also prevented the generation of superoxide by the phagocytic NADPH oxidase complex, potentially by inhibiting the interaction of Rac and p67. Furthermore, the interaction of GTPases with the E3 ubiquitin ligases cIAP1 and XIAP was hindered, leading to decreased degradation of Rac and RhoA during infection. Finally, we screened for novel Rac1 interactions using a nucleic acid programmable protein array and discovered that Rac1 binds to the protein C1QA, a protein known to promote immune signaling in the cytosol. Interestingly, this interaction was disrupted by AMPylation. We conclude that AMPylation of Rho Family GTPases by VopS results in diverse inhibitory consequences during infection beyond the most obvious phenotype, the collapse of the actin cytoskeleton.This research was originally published in JOURNAL OF BIOLOGICAL CHEMISTRY. Woolery, Andrew R., Yu, Xiaobo, LaBaer, Joshua, & Orth, Kim. [Title]. JOURNAL OF BIOLOGICAL CHEMISTRY. 2014; 289:0-0. © the American Society for Biochemistry and Molecular Biology
Correlated hyperfine interactions in amorphous Cr72-xFexC17Si8Al3 alloys
No full textPT: J; CR: BAHADUR D, 1987, J MATER SCI, V22, P2477 DINI K, 1986, J MATER SCI, V21, P1037 DUNLAP RA, 1982, CAN J PHYS, V60, P909 DUNLAP RA, 1985, J MATER SCI LETT, V4, P773 EIBSCHUTZ M, 1983, PHYS REV B, V28, P425 INGALLS R, 1978, MOSSBAUER ISOMER SHI, P361 LECAER G, 1979, J PHYS E SCI INSTRUM, V12, P1083 OLIVIER M, 1982, J APPL PHYS, V53, P7696 POLLARD RJ, 1984, PHYS REV B, V29, P4864 YU BL, 1984, J APPL PHYS, V55, P1748; NR: 10; TC: 10; J9: J PHYS-F-METAL PHYS; PG: 8; GA: R0716Source type: Electronic(1
AlGaN/GaN HEMT micro-sensor technology for gas sensing applications
No full text Wide bandgap gallium nitride material has highly favorable electronic properties for next generation power and high frequency electronic devices. A less widely studied application is highly miniaturized chemical and gas sensors capable of operating in harsh environment conditions. In this work we present our recent developments on design, fabrication and testing of AlGaN/GaN high electron mobility transistor (HEMT) based sensors for detection of various gases. First, the method of as-fabricated device baseline value stabilization is demonstrated. Secondly, the impact of sensor design is discussed with the emphasis on gate electrode geometry optimizations to enhance sensing performance. Then we present the sensing characteristics of Pt-HEMTs towards H 2 S and compare them to H 2 and NO 2 . Finally we demonstrate recent results of NO 2 detection with Ti/Au based HEMT sensors, which are superior to those using Pt based devices. Accepted author manuscriptElectronic Components, Technology and Material
The etiology of esophageal cancer in high- and low- risk areas of Jiangsu province, China
No full text [Background]Esophageal cancer (EC) remains one of the most common and fatal malignancies worldwide. The geographic variation in EC occurrence is striking, and China is an area with one of the highest incidences of EC. A number of epidemiological studies have been conducted toward EC in the past decades, results suggested that tobacco smoking, alcohol drinking, unhealthy dietary factors and chronic injuries of the esophageal mucosa are important in the development of this disease. Genetic polymorphisms in enzymes involved in metabolism of carcinogens may also influence individual susceptibility. However, the effects of major lifestyle and hereditary risk factors on the development of EC remain poorly understood in China. Moreover, little attention has been paid to the etiological heterogeneity between similar areas with great risk gradient. [Methods]From 2003 to 2007, a large population-based case-control study of EC has been conducted in a selected high-risk area and a selected low-risk area of Jiangsu Province, one of the highest cancer incidence areas in China. In total, 1,520 cases and 3,879 controls were recruited. In this thesis, we evaluated the role of major lifestyle factors such as tobacco smoking, alcohol drinking and dietary factors, as well as inherited determinants including family history of cancer and genetic polymorphisms of alcohol-metabolizing related genes on the risk of EC. In addition, we investigated how much of the risk gradient between two areas could be explained by variation in the distributions of major risk factors. [Results] Tobacco smoking and alcohol drinking moderately increased the risk of EC, while the positive associations were only found among men but not among women. Dietary factors were observed to play important roles in the development of EC. Specific dietary habits i.e., fast eating speed, and hot eating and/or drinking substantially elevated EC risk and could explain more than 20% of EC cases each. High intake of salty foods and fried foods, low consumption of raw garlic were also observed to increase the risk of EC. In addition to environmental and lifestyle factors, we confirmed that a positive family history can significantly increase EC risk, and found the inheritance may modify the effect of some unhealthy lifestyles. Moreover, we further explored the relationship between EC and single nucleotide polymorphismsof ADH1B, ADH1C and ALDH2 genes. Results showed that the slow metabolizing ADH1B G allele, ADH1C G allele and ALDH2 A allele significantly increased EC risk among moderate-to-heavy alcohol drinkers, and a significant interaction was observed between ALDH2 gene and alcohol consumption. Lastly, we found that more than 60% of EC cases could be attributable to major lifestyle risk factors in the study population; furthermore, dissimilar distribution of several lifestyle factors, together with variations of hereditary factors may be largely responsible for the incidence difference between two study areas. [Conclusion]The findings in this thesis confirm that unhealthy lifestyles including smoking, alcohol drinking and some dietary factors are the predominant risk factors of EC in China, and a large proportion of incidence difference between regions at varying risk could be attributed to the different prevalence of lifestyle factors. As most of the identified risk factors are modifiable, these could be translated into risk reduction prevention programs in China, and a substantial proportion of new EC cases are expected to be prevented by eliminating or avoiding these risk factors in the population. </p
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Cold-formed Steel Framed Shear Wall Sheathed with Corrugated Sheet Steel
No full textIncombustibility is one important advantage of the sheet steel sheathed shear wall over wood panel sheathed shear wall. Compared to shear wall sheathed with plywood and OSB panel, shear wall sheathed with flat sheet steel behaved lower shear strength. Although shear wall sheathed with corrugated sheet steel exhibited high nominal strength and high stiffness, the shear wall usually behaved lower ductility resulting from brittle failure at the connection between the sheathing to frames. This research is aimed at developing modifications on the corrugated sheathing to improve the ductility of the shear wall as well as derive practical response modification factor by establishing correct relationship between ductility factor ? and response modification factor R. Totally 21 monotonic and cyclic full-scale shear wall tests were conducted during the winter break in 2012 by the author in NUCONSTEEL Materials Testing Laboratory in the University of North Texas. The research investigated nineteen 8 ft. × 4 ft. shear walls with 68 mil frames and 27 mil corrugation sheet steel in 11 configurations and two more shear walls sheathed with 6/17-in.OSB and 15/32-in. plywood respectively for comparison. The shear walls, which were in some special cutting arrangement patterns, performed better under lateral load conditions according to the behavior of ductility and shear strength and could be used as lateral system in construction
Directional features of the downshifted peak observed in HF-induced stimulated electromagnetic emission spectra obtained using an interferometer
No full textInternational audienceA high frequency (HF) ionospheric modification experiment was carried out between 25 September and 8 October 2004, using the EISCAT HF transmitter located near Tromsø, Norway. During this experiment the spectra of the stimulated HF sideband waves (stimulated electromagnetic emission or SEE) induced by the HF pump were observed using an interferometer consisting of three spaced receiving antennas with baselines both along and perpendicular to the meridian, and a multi-channel coherent receiver, installed in the vicinity of the HF facility. The transmitter operated at 4040kHz and its antenna beam was scanned to angles of 0°, 7°, 14°, and 21° south from vertical, pausing 4min at each position. This paper focuses on features of the downshifted peak (DP) emission, which has not been as thoroughly studied as many of the other SEE spectral features observable within the EISCAT pump frequency range. It was found that the signal-weighted direction of the DP source region remained within 5° of magnetic zenith as the HF beam was tilted between 0 and 21° south of vertical
Singularity problem in the f(R) model with nonminimal coupling
No full textWe consider the nonminimal coupling between matter and the geometry in the f(R) theory. In the new theory which we established, a new scalar psi has been defined and we give it a certain stability condition. We intend to take a closer look at the dark energy oscillating behavior in the de Sitter universe and the matter era, from which we derive the oscillating frequency and the oscillating condition. More importantly, we present the condition of coupling form that the singularity can be solved. We discuss several specific coupling forms and find that logarithmic coupling with an oscillating period Delta T similar to Delta z in the matter era z > 4 can improve singularity in the early universe. The result of numerical calculation verifies our theoretic calculation about the oscillating frequency. Considering two toy models, we find the cosmic evolution in the coupling model is nearly the same as that in the normal f(R) theory when lna > 4. We also discuss the local tests of the nonminimal coupling f(R) model and show the constraint on the coupling form. DOI: 10.1103/PhysRevD.86.123526http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000312836000002&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=8e1609b174ce4e31116a60747a720701Astronomy & AstrophysicsPhysics, Particles & FieldsSCI(E)6ARTICLE12null8
Biotransformation of 20(R)-panaxadiol by the fungus Rhizopus chinensis
No full textMicrobial transformation of 20(R)-panaxadiol by the fungus Rhizopus chinensis CICC 3043 yielded seven metabolites. Their structures were elucidated on the basis of extensive spectroscopic analyses. R. chinensis could catalyze hydroxylation and further dehydrogenation at C-24 of 20(R)-panaxadiol, as well as hydroxylation at C-7, C-15, C-16, and C-29. Three of these compounds at 10 mu M could moderately inhibit growth of HepG2 human hepatocellular carcinoma cells with an inhibition rate of about 40%. Three compounds (also at 10 mu M) showed approximately 30% inhibition on NF-kappa B transcriptional activity in SW480 human colon carcinoma cells stably transfected with NF-kappa B luciferase reporter and induced by LPS. (C) 2014 Elsevier Ltd. All rights reserved.http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000340986900016&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=8e1609b174ce4e31116a60747a720701Biochemistry & Molecular BiologyPlant SciencesSCI(E)[email protected]; [email protected]
Phonology of middle Mongolian in 'Da-da yi-yu'
No full textThis paper is concerned with the phones of middle Mongolian transcribed by Chinese characters in the glossary 『韃靼譯語(Da-da yi-yu)』. This text is the Mongolian part of the type 丙 of the glossaries ｢華夷譯語(Hua-yi yi-yu)｣ in which words of Chinese were contrasted with those of some foreign languages in Ming and Qing dynasties. 『韃靼譯語』was written for interpreters to study the Mongolian language. So it is expected that the phones of colloquial Mongolian were described more naturally in this text than in the other texts. In this paper, we reconstructed the phones of middle Mongolian in 『韃靼譯語』 and revealed the system of transcription using the phones of Chinese in 『重訂司馬温公等韻図経』 written in 1606. Consequently we found the following features peculiar to 『韃靼譯語』. (i) t, k, ɣ, l at the end of syllables are not transcribed frequently. (ii) ɣ preceded by l, r and ŋ is often transcribed by a Chinese consonant zero (影母). (iii) The phone ər of Chinese is used for the transcription of liquids. These features show that the author of 『韃靼譯語』 heard the phones of colloquial Mongolian and transcribed them naturally using the phones of his own Chinese, not artificially through written Mongolian
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