59 research outputs found
Estimating Early Fundraising Performance of Innovations via Graph-based Market Environment Model
Well begun is half done. In the crowdfunding market, the early fundraising
performance of the project is a concerned issue for both creators and
platforms. However, estimating the early fundraising performance before the
project published is very challenging and still under-explored. To that end, in
this paper, we present a focused study on this important problem in a market
modeling view. Specifically, we propose a Graph-based Market Environment model
(GME) for estimating the early fundraising performance of the target project by
exploiting the market environment. In addition, we discriminatively model the
market competition and market evolution by designing two graph-based neural
network architectures and incorporating them into the joint optimization stage.
Finally, we conduct extensive experiments on the real-world crowdfunding data
collected from Indiegogo.com. The experimental results clearly demonstrate the
effectiveness of our proposed model for modeling and estimating the early
fundraising performance of the target project
Output Voltage Response Improvement and Ripple Reduction Control for Input-parallel Output-parallel High-Power DC Supply
A three-phase isolated AC-DC-DC power supply is widely used in the industrial
field due to its attractive features such as high-power density, modularity for
easy expansion and electrical isolation. In high-power application scenarios,
it can be realized by multiple AC-DC-DC modules with Input-Parallel
Output-Parallel (IPOP) mode. However, it has the problems of slow output
voltage response and large ripple in some special applications, such as
electrophoresis and electroplating. This paper investigates an improved
Adaptive Linear Active Disturbance Rejection Control (A-LADRC) with flexible
adjustment capability of the bandwidth parameter value for the high-power DC
supply to improve the output voltage response speed. To reduce the DC supply
ripple, a control strategy is designed for a single module to adaptively adjust
the duty cycle compensation according to the output feedback value. When
multiple modules are connected in parallel, a Hierarchical Delay Current
Sharing Control (HDCSC) strategy for centralized controllers is proposed to
make the peaks and valleys of different modules offset each other. Finally, the
proposed method is verified by designing a 42V/12000A high-power DC supply, and
the results demonstrate that the proposed method is effective in improving the
system output voltage response speed and reducing the voltage ripple, which has
significant practical engineering application value.Comment: Accepted by IEEE Transactions on Power Electronic
The effects of (+)-Gossypol on 11β-HSD and the concentration of corticosterone and dehydrocorticosterone in mice serum and tissues
11β-hydroxysteroid dehydrogenase (11β-HSD) plays an important part in mediating glucocorticoid action, catalyzing the interconversion of corticosterone (B) and dehydrocorticosterone (A) in rodents. The aim of our study is to investigate the effects of (+)-gossypol (G+) on 11β-HSD. Adult ICR mice were given B and B + (G+) by intraperitoneal injection. The activity of 11β-HSD was evaluated by measuring the ratio of A and B, meanwhile the effects of (+)-gossypol on the conversion rate of B to A was determined with HPLC. Serum A/B levels of the B+(G+) group decreased by 2.42, 7.32, 17.85, 31.39, and 40.02 % compared to the B group at each measured time interval. A/B levels at 1 h for the B + (G+) group decreased by 43.78, 21.29 and 34.47% in liver, kidney and adrenal glands, respectively, in comparison to the B group. However, (+)-gossypol had no effect on brain and testis. (+)-Gossypol was an inhibitor of 11β-HSD.Colegio de Farmacéuticos de la Provincia de Buenos Aire
The effects of (+)-Gossypol on 11β-HSD and the concentration of corticosterone and dehydrocorticosterone in mice serum and tissues
11β-hydroxysteroid dehydrogenase (11β-HSD) plays an important part in mediating glucocorticoid action, catalyzing the interconversion of corticosterone (B) and dehydrocorticosterone (A) in rodents. The aim of our study is to investigate the effects of (+)-gossypol (G+) on 11β-HSD. Adult ICR mice were given B and B + (G+) by intraperitoneal injection. The activity of 11β-HSD was evaluated by measuring the ratio of A and B, meanwhile the effects of (+)-gossypol on the conversion rate of B to A was determined with HPLC. Serum A/B levels of the B+(G+) group decreased by 2.42, 7.32, 17.85, 31.39, and 40.02 % compared to the B group at each measured time interval. A/B levels at 1 h for the B + (G+) group decreased by 43.78, 21.29 and 34.47% in liver, kidney and adrenal glands, respectively, in comparison to the B group. However, (+)-gossypol had no effect on brain and testis. (+)-Gossypol was an inhibitor of 11β-HSD.Colegio de Farmacéuticos de la Provincia de Buenos Aire
Mutations in porin LamB contribute to ceftazidime-avibactam resistance in KPC-producing Klebsiella pneumoniae.
Ceftazidime-avibactam (CAZ-AVI) shows promising activity against carbapenem-resistant Klebsiella pneumoniae (CRKP), however, CAZ-AVI resistance have emerged recently. Mutations in KPCs, porins OmpK35 and/or OmpK36, and PBPs are known to contribute to the resistance to CAZ-AVI in CRKP. To identify novel CAZ-AVI resistance mechanism, we generated 10 CAZ-AVI-resistant strains from 14 CAZ-AVI susceptible KPC-producing K. pneumoniae (KPC-Kp) strains through in vitro multipassage resistance selection using low concentrations of CAZ-AVI. Comparative genomic analysis for the original and derived mutants identified CAZ-AVI resistance-associated mutations in KPCs, PBP3 (encoded by ftsI), and LamB, an outer membrane maltoporin. CAZ-AVI susceptible KPC-Kp strains became resistant when complemented with mutated blaKPC genes. Complementation experiments also showed that a plasmid borne copy of wild-type lamB or ftsI gene reduced the MIC value of CAZ-AVI in the induced resistant strains. In addition, blaKPC expression level increased in four of the six CAZ-AVI-resistant strains without KPC mutations, indicating a probable association between increased blaKPC expression and increased resistance in these strains. In conclusion, we here identified a novel mechanism of CAZ-AVI resistance associated with mutations in porin LamB in KPC-Kp
Twin-field quantum key distribution without phase locking
Twin-field quantum key distribution (TF-QKD) has emerged as a promising
solution for practical quantum communication over long-haul fiber. However,
previous demonstrations on TF-QKD require the phase locking technique to
coherently control the twin light fields, inevitably complicating the system
with extra fiber channels and peripheral hardware. Here we propose and
demonstrate an approach to recover the single-photon interference pattern and
realize TF-QKD \emph{without} phase locking. Our approach separates the
communication time into reference frames and quantum frames, where the
reference frames serve as a flexible scheme for establishing the global phase
reference. To do so, we develop a tailored algorithm based on fast Fourier
transform to efficiently reconcile the phase reference via data
post-processing. We demonstrate no-phase-locking TF-QKD from short to long
distances over standard optical fibers. At 50-km standard fiber, we produce a
high secret key rate (SKR) of 1.27 Mbit/s, while at 504-km standard fiber, we
obtain the repeater-like key rate scaling with a SKR of 34 times higher than
the repeaterless secret key capacity. Our work provides a scalable and
practical solution to TF-QKD, thus representing an important step towards its
wide applications.Comment: Published versio
Simultaneous determination of cortisone and cortisol in serum by HPLC-DAD and application for pharmacokinetics
To develop a high performance liquid chromatography method for the simultaneous determination of cortisone and cortisol in rat serum and apply it for pharmacokinetics. After addition of pirfenidone as internal standard (IS), a liquid-liquid extraction with ethylacetate was employed for the sample preparation. Samples were separated on Zorbax SB-C18 column at 25 ºC using mobile phase consisting of acetonitrile-water-0.1 % trifluoroacetic acid with flow rate of 0.9 mL/min, utilizing DAD detection at 246 nm. Excellent liner relationships of the cortisone and cortisol concentrations were obtained from 50 to 6000 ng/mL, with r = 0.9997, 0.9999 respectively, and the lower limit of quantitation (LLOQ) were both 50 ng/mL. The developed method was successfully applied to pharmacokinetic studies of cortisone and cortisol in rats following single dose of 20 mg/kg via intraperitoneal injection.Colegio de Farmacéuticos de la Provincia de Buenos Aire
Global emergence of a hypervirulent carbapenem-resistant <i>Escherichia coli </i>ST410 clone
Carbapenem-resistant Escherichia coli (CREC) ST410 has recently emerged as a major global health problem. Here, we report a shift in CREC prevalence in Chinese hospitals between 2017 and 2021 with ST410 becoming the most commonly isolated sequence type. Genomic analysis identifies a hypervirulent CREC ST410 clone, B5/H24RxC, which caused two separate outbreaks in a children's hospital. It may have emerged from the previously characterised B4/H24RxC in 2006 and has been isolated in ten other countries from 2015 to 2021. Compared with B4/H24RxC, B5/H24RxC lacks the blaOXA-181-bearing X3 plasmid, but carries a F-type plasmid containing blaNDM-5. Most of B5/H24RxC also carry a high pathogenicity island and a novel O-antigen gene cluster. We find that B5/H24RxC grew faster in vitro and is more virulent in vivo. The identification of this newly emerged but already globally disseminated hypervirulent CREC clone, highlights the ongoing evolution of ST410 towards increased resistance and virulence. </p
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