3,028 research outputs found
Government R&D subsidies and enterprise R&D activities: theory and evidence
Under the control of multi-dimensional factors such as industry
and enterprise characteristics, this paper examines the impact
of government R&D subsidies on enterprise R&D activities,
both theoretically and empirically. Theoretically, on the basis of
Symeonidis model, this paper establishes a three-stage dynamic
game model by introducing the government R&D subsidy, in
order to expand the existing theory. Taking the data of the listed
enterprises in China as the research sample, the Spatial Quantile
Autoregressive Regression method, which has the ability to examine both spatial effect and quantile effect, is used to test the theoretical results. It is found that R&D subsidies play a significant
positive role in stimulating the R&D activities of enterprises, and
the incentive effect of subsidies is more obvious with the increase
of R&D investment and R&D efficiency. Furthermore, the spillover
effect can improve R&D efficiency, and this effect will be gradually
strengthened with the increase of quantile
Shareholding structure, private benefit of control and incentive intensity: from the perspective of enterprise strategic behaviour
This paper studies theoretically and empirically the relationship
among shareholding structure, the private benefit of control and
incentive intensity. By integrating the principalāagent theory and
the market competition theory into the three-stage dynamic
game model, we built the dual principalāagent relationship
including both āshareholder-managerā and ācontrolling shareholders-small and medium shareholdersā. Empirically, the panel data
of 1971 listed enterprises in China from the year 2007 to 2014 are
analysed in order to justify the theoretical results by using twoway fixed effect model, dynamic panel model, and threshold
regression model. It is shown that for enterprise managers, the
higher their ability level and risk aversion, the stronger their
incentive intensity will be. However, for shareholders, the private
benefit of control and the incentive intensity show a non-linear
relationship with the change of ownership concentration
How trade affects high-quality development through spillovers?
This paper derives the empirical estimation model from the
endogenous economic growth theory, and tries to provide an
effective and reasonable answer to the question āhow trade
affects high-quality development through spilloversā from the perspective
of spatial interdependence. Based on the data of 69
countries from 2000 to 2015, it is confirmed that there is an obvious
spatial correlation between neighboring countriesā TFP, the
TFP of geographical and economic neighboring countries shows
ācompetition effectā, while the TFP of cultural neighboring countries
shows āfirst spillover effect, then competition effectā. The
R&D capital investment has no spatial effect on TFP of geographically
or economically neighboring countries, but it has a significant
āspillover effectā on TFP of culturally neighboring countries.
Technology spillovers caused by international trade are not only
an important factor for countries to promote TFP, but also the
core driving force to achieve high-quality development
KliniÄka primjena RT-PCR u otkrivanju DNK tuberkuloze u kombinaciji s TB-IGRA u dijagnostici pluÄne tuberkuloze s negativnim nalazom sputuma
The aim was to investigate detection of pulmonary alveolar lavage fluid tuberculosis
DNA by real-time fluorescent polymerase chain reaction (RT-PCR) combined with clinical application
of the sputum smear-negative pulmonary tuberculosis diagnosis with TB interferon-Ī³ release
assay (TB-IGRA). From October 2014 to October 2015, 632 outpatients and inpatients treated in our
hospital were randomly selected, of which 459 patients as the research group managed with RT-PCR
detection combined with TB-IGRA and 173 patients as the control group undergoing electronic
bronchoscopy alveolar lavage fluid detection, with detection results statistically evaluated. The positive
rate in the research group was 96.51%, i.e. significantly higher than that in the control group (66.47%),
yielding a statistically significant difference (Ļ2=109.68, p=0.00). The true positive rate was 97.7% in
the research group and 67.92% in the control group; the true positive rate was significantly higher in
the research group patients as compared with the control group, yielding a statistically significant difference
(Ļ2=112.04, p=0.00). The sensitivity and specificity, as well as Youden index were significantly
higher in the research group as compared with the control group. In conclusion, TB DNA detection
by RT-PCR combined with TB-IGRA is a very good method of diagnosing tuberculosis, and it can
be implemented in clinical diagnosis of pulmonary tuberculosis.Cilj istraživanja bio je ispitati otkrivanje DNK tuberkuloze u pluÄnom alveolarnom ispirku pomoÄu lanÄane reakcije
polimeraze u stvarnom vremenu s fluorescentnim bojama (RT-PCR) u kombinaciji s kliniÄkom primjenom dijagnostike
pluÄne tuberkuloze s negativnim nalazom sputuma pomoÄu testa otpuÅ”tanja TB interferona-Ī³ (TB-IGRA). Od listopada
2014. do listopada 2015. godine nasumce su odabrane 632 osobe bolniÄki i izvanbolniÄki lijeÄene u naÅ”oj bolnici, od kojih
je 459 ukljuÄeno u ispitnu skupinu podvrgnutu otkrivanju pomoÄu RT-PCR u kombinaciji s testom TB-IGRA, a 173 u
kontrolnu skupinu podvrgnutu elektroniÄkom otkrivanju u bronhoskopskom alveolarnom ispirku; rezultati su statistiÄki
obraÄeni. Stopa pozitivnih nalaza bila je 96,51% u ispitnoj skupini, odnosno znaÄajno viÅ”a od one u kontrolnoj skupini
(66,47%), uz statistiÄki znaÄajnu razliku (Ļ2=109,68; p=0,00). Stopa stvarno pozitivnih nalaza bila je 97,7% u ispitnoj skupini
i 67,92% u kontrolnoj skupini, dakle znaÄajno viÅ”a kod bolesnika ispitne skupine u usporedbi s kontrolnom skupinom, uz
statistiÄki znaÄajnu razliku (Ļ2=112,04; p=0,00). Osjetljivost i specifiÄnost, kao i Youdenov indeks bili su znaÄajno viÅ”i u
ispitnoj skupini u usporedbi s kontrolnom skupinom. U zakljuÄku, otkrivanje TB DNK pomoÄu RT-PCR u kombinaciji s
TB-IGRA vrlo je dobra metoda za dijagnosticiranje tuberkuloze, koja se može primjenjivati u kliniÄkoj dijagnostici pluÄne
tuberkuloze
AGROBEST: an efficient Agrobacterium-mediated transient expression method for versatile gene function analyses in Arabidopsis seedlings
Background: Transient gene expression via Agrobacterium-mediated DNA transfer offers a simple and fast method to analyze transgene functions. Although Arabidopsis is the most-studied model plant with powerful genetic and genomic resources, achieving highly efficient and consistent transient expression for gene function analysis in Arabidopsis remains challenging. Results: We developed a highly efficient and robust Agrobacterium-mediated transient expression system, named AGROBEST (Agrobacterium-mediated enhanced seedling transformation), which achieves versatile analysis of diverse gene functions in intact Arabidopsis seedlings. Using Ī²-glucuronidase (GUS) as a reporter for Agrobacterium-mediated transformation assay, we show that the use of a specific disarmed Agrobacterium strain with vir gene pre-induction resulted in homogenous GUS staining in cotyledons of young Arabidopsis seedlings. Optimization with AB salts in plant culture medium buffered with acidic pH 5.5 during Agrobacterium infection greatly enhanced the transient expression levels, which were significantly higher than with two existing methods. Importantly, the optimized method conferred 100% infected seedlings with highly increased transient expression in shoots and also transformation events in roots of ~70% infected seedlings in both the immune receptor mutant efr-1 and wild-type Col-0 seedlings. Finally, we demonstrated the versatile applicability of the method for examining transcription factor action and circadian reporter-gene regulation as well as protein subcellular localization and proteināprotein interactions in physiological contexts. Conclusions: AGROBEST is a simple, fast, reliable, and robust transient expression system enabling high transient expression and transformation efficiency in Arabidopsis seedlings. Demonstration of the proof-of-concept experiments elevates the transient expression technology to the level of functional studies in Arabidopsis seedlings in addition to previous applications in fluorescent protein localization and proteināprotein interaction studies. In addition, AGROBEST offers a new way to dissect the molecular mechanisms involved in Agrobacterium-mediated DNA transfer
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Phase Control on Surface for the Stabilization of High Energy Cathode Materials of Lithium Ion Batteries.
The development of high energy electrode materials for lithium ion batteries is challenged by their inherent instabilities, which become more aggravated as the energy densities continue to climb, accordingly causing increasing concerns on battery safety and reliability. Here, taking the high voltage cathode of LiNi0.5Mn1.5O4 as an example, we demonstrate a protocol to stabilize this cathode through a systematic phase modulating on its particle surface. We are able to transfer the spinel surface into a 30 nm shell composed of two functional phases including a rock-salt one and a layered one. The former is electrochemically inert for surface stabilization while the latter is designated to provide necessary electrochemical activity. The precise synthesis control enables us to tune the ratio of these two phases, and achieve an optimized balance between improved stability against structural degradation without sacrificing its capacity. This study highlights the critical importance of well-tailored surface phase property for the cathode stabilization of high energy lithium ion batteries
Synthesis, Crystal Structure, Spectroscopic Properties, and Interaction with Ct-DNA of Zn(II) with 2-Aminoethanethiol Hydrochloride Ligand
The zinc(II) complex (C 2 H 6 NS) 2 Znā
ZnCl 2 was synthesized with 2-aminoethanethiol hydrochloride and zinc sulfate heptahydrate as the raw materials in aqueous solution. The composition and structure of the complex were characterized by elemental analysis, infrared spectra, single crystal X-ray diffraction, and thermogravimetry. The crystal structure of the zinc(II) complex belongs to monoclinic system, space group 2 1 / , with cell parameters of = 0.84294(4), = 0.83920(4), = 1.65787(8) nm, = 2, and = 2.041 g/cm 3 . In this paper, the interaction of complex with Ct-DNA was investigated by UV-visible and viscosimetric techniques. Upon addition of the complex, important changes were observed in the characteristic UV-Vis bands (hyperchromism) of calf thymus DNA and some changes in specific viscosity. The experimental results showed that the complex is bound to DNA intercalative (intercalation binding)
Ser-634 and Ser-636 of Kaposiās Sarcoma-Associated Herpesvirus RTA are Involved in Transactivation and are Potential Cdk9 Phosphorylation Sites
The replication and transcription activator (RTA) of Kaposiās sarcoma-associated herpesvirus (KSHV), K-RTA, is a lytic switch protein that moderates the reactivation process of KSHV latency. By mass spectrometric analysis of affinity purified K-RTA, we showed that Thr-513 or Thr-514 was the primary in vivo phosphorylation site. Thr-513 and Thr-514 are proximal to the nuclear localization signal (527KKRK530) and were previously hypothesized to be target sites of Ser/Thr kinase hKFC. However, substitutions of Thr with Ala at 513 and 514 had no effect on K-RTA subcellular localization or transactivation activity. By contrast, replacement of Ser with Ala at Ser-634 and Ser-636 located in a Ser/Pro-rich region of K-RTA, designated as S634A/S636A, produced a polypeptide with ā¼10ākDa shorter in molecular weight and reduced transactivation in a luciferase reporter assay relative to the wild type. In contrast to prediction, the decrease in molecular weight was not due to lack of phosphorylation because the overall Ser and Thr phosphorylation state in K-RTA and S634A/S636A were similar, excluding that Ser-634 or Ser-636 motif served as docking sites for consecutive phosphorylation. Interestingly, S634A/S636A lost ā¼30% immuno-reactivity to MPM2, an antibody specific to pSer/pThr-Pro motif, indicating that 634SPSP637 motif was in vivo phosphorylated. By in vitro kinase assay, we showed that K-RTA is a substrate of CDK9, a Pro-directed Ser/Thr kinase central to transcriptional regulation. Importantly, the capability of K-RTA in associating with endogenous CDK9 was reduced in S634A/S636A, which suggested that Ser-634 and Ser-636 may be involved in CDK9 recruitment. In agreement, S634A/S636A mutant exhibited ā¼25% reduction in KSHV lytic cycle reactivation relative to that by the wild type K-RTA. Taken together, our data propose that Ser-634 and Ser-636 of K-RTA are phosphorylated by host transcriptional kinase CDK9 and such a process contributes to a full transcriptional potency of K-RTA
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