110 research outputs found
Supplemental Material - A nomogram to predict nosocomial infection in patients on venoarterial extracorporeal membrane oxygenation after cardiac surgery
No full textSupplemental Material for A nomogram to predict nosocomial infection in patients on venoarterial extracorporeal membrane oxygenation after cardiac surgery by Xiyuan Li, Liangshan Wang, Chenglong Li, Xiaomeng Wang, Xing Hao, Zhongtao Du, Haixiu Xie, Feng Yang, Hong Wang, and Xiaotong Hou in Perfusion</p
Competitive market research and product design
No full textTo learn the uncertainty of customer preference on the attribute of new product, usually a firm needs to do market research. Developing a product on an attribute which is less preferred by customer may lead to a failure. In addition, a firm used to take efforts to design the product. In recent years, we observed a new business model in which the firm does not take effort to design new product, nor does she do market research by herself. She provides rewards to attract outside designers to design new product. Some designers may take effort and design products based on their private information of customer preference. The firm receives designs with different quality and attribute, she chooses one to produce. By solving this game model, we get the equilibrium quality of the design offered by each designer based on their private cost parameter. And we obtain the following insights: When the market size is too small, the firm gives nothing to designers; when the market size is sufficiently big, the firm only gives reward to the designer whose design is produced; otherwise the firm gives both rewards to participated designers and the designer whose design is produced. We find that when the market size is big enough or the disutility is high enough, the new business model dominates the benchmark business model. When both the disutility and market size are small enough, the firm prefers the benchmark business model. And the relative attractiveness of new business model versus benchmark model keeps the same when the market size is small enough. The impact of extra reward on relative attractiveness of new business model versus benchmark model increases with extra reward. When the extra reward is high enough, the firm always prefers the new business model
Strain-specific enterotoxin secretion and impact of gut epithelial cells on porcine ETEC toxin secretion
No full textPorcine ETEC is an important cause of bacterial diarrheal illness and is regarded as a global health threat for farm animals. Neonatal diarrhea (ND) and post weaning diarrhea (PWD) caused by ETEC result in severe economic losses for the farming industry worldwide due to increased morbidity and mortality and reduced growth rates. Neonatal piglets can be protected by the transfer of maternal antibodies upon vaccination of the sow. However, upon weaning piglets become highly susceptible to ETEC as the passive immunity wanes at weaning. To protect newly weaned piglets against ETEC infections, an oral live bivalent vaccine, Coliprotec® F4/F18 (Elanco GmbH), has been marketed in the EU and other countries since 2017. However, it could not provide complete protection to piglets. Furthermore, the live vaccine has some limitations and associated risks. Therefore, further research into the development of vaccines or alternative strategies is needed. This requires a deeper understanding of the pathogenesis of ETEC and its interaction with its hosts at the molecular level
Development and validation of a nomogram for predicting antibiotic treatment duration in patients with liver abscess complicated by diabetes
No full textAbstract This study aimed to identify the recovery predictors for patients with pyogenic liver abscess (PLA) and diabetes who are undergoing antibiotic therapy, and to develop an effective nomogram for predicting the antibiotic treatment duration (ORT). This retrospective study included consecutive PLA patients with diabetes who received antibiotic treatment, with ORT defined as the time from the initiation of antibiotic therapy to its cessation. Univariate and multivariate analyses were performed to identify the main predictors of ORT. Kaplan-Meier survival curves and a nomogram were subsequently constructed to predict ORT, and the accuracy of the nomogram was assessed using Harrell’s C-statistic and calibration curves. A total of 139 PLA patients with diabetes were included, with a median ORT of 17 days (interquartile range: 13–22 days). The study found that fever (P < 0.01), pre-treatment septic shock (P < 0.01), abscess diameter greater than 5 cm (P < 0.01), and elevated white blood cell count (P = 0.04) were independent risk factors for prolonged ORT, suggesting that patients with these factors had a significantly longer ORT compared to those without them. Prognostic analysis showed that patients exhibiting more predictive factors (e.g., high fever, shock, larger abscess, elevated white blood cell count) had a significantly extended ORT. Based on these factors, we developed a nomogram to predict ORT, with a Harrell’s C-statistic of 0.75, indicating good predictive accuracy. The calibration curve for predicting ORT demonstrated good consistency between the expected and actual results. This nomogram provides clinicians with a simple and practical tool to assess patient prognosis and guide the appropriate cessation of antibiotic treatment
Intestinal Epithelial Cells Modulate the Production of Enterotoxins by Porcine Enterotoxigenic E. coli Strains
No full textEnterotoxigenic Escherichia coli (ETEC) strains are one of the most common etiological agents of diarrhea in both human and farm animals. In addition to encoding toxins that cause diarrhea, ETEC have evolved numerous strategies to interfere with host defenses. These strategies most likely depend on the sensing of host factors, such as molecules secreted by gut epithelial cells. The present study tested whether the exposure of ETEC to factors secreted by polarized IPEC-J2 cells resulted in transcriptional changes of ETEC-derived virulence factors. Following the addition of host-derived epithelial factors, genes encoding enterotoxins, secretion-system-associated proteins, and the key regulatory molecule cyclic AMP (cAMP) receptor protein (CRP) were substantially modulated, suggesting that ETEC recognize and respond to factors produced by gut epithelial cells. To determine whether these factors were heat sensitive, the IEC-conditioned medium was incubated at 56 °C for 30 min. In most ETEC strains, heat treatment of the IEC-conditioned medium resulted in a loss of transcriptional modulation. Taken together, these data suggest that secreted epithelial factors play a role in bacterial pathogenesis by modulating the transcription of genes encoding key ETEC virulence factors. Further research is warranted to identify these secreted epithelial factors and how ETEC sense these molecules to gain a competitive advantage in the early engagement of the gut epithelium
Comprehensive identification of 125 multifarious constituents in Shuang-huang-lian powder injection by HPLC-DAD-ESI-IT-TOF-MS
No full textA high-performance liquid chromatography-diode array detector-electrospray ionization-ion trap-time of flight-mass spectrometry (HPLC-DAD-ESI-IT-TOF-MS) method was established for excellent separation and structural identification of constituents in Shuang-huang-lian powder injection (SHLPI). The typical ultraviolet absorptions, accurate empirical molecular formula and reasonable fragmentation mechanisms of these ingredients were used for their structural elucidation. In consequence, 125 constituents (33 phenolic acids, 29 flavonoids, 32 phenylethanoid glycosides, 15 iridoid glycosides, 8 lignans, 3 amino acids and 2 purines nucleosides, 2 quinoid glycosides and 1 alkylbenzene glycoside) were either unequivocally identified or tentatively characterized by comparing authentic standards or published data. The result showed that this study could provide valuable information for the quality control and further investigation of SHLPI formula. (C) 2015 Elsevier B.V. All rights reserved.Natural Science Foundation of Beijing, China [7142088]SCI(E)[email protected]; [email protected]
An on-line high-performance liquid chromatography-diode-array detector multi-stage mass spectrometry-deoxyribonucleic acid-4 ',6-diamidino-2-phenylindole-fluorescence detector system for screening the DNA-binding active compounds in Fufang Banbia
No full textFufang Banbianlian Injection (FBI), a well-known traditional Chinese medicine formula, has been recently approved and extensively used as a newly anti-inflammatory and anti-tumor drug. This prescription comprises an equal ratio of three traditional Chinese herbs, Lobelia chinensis Lour, Scutellaria barbata D. Don and Hedyotis diffusa Willd. The relationships between its chemical compositions and activities have not been understood well yet. To investigate the ingredients and their DNA-binding activities in FBI, an on-line high-performance liquid chromatography diode-array detector-multi-stage mass spectrometry-deoxyribonucleic acid-4',6-diamidino-2-phenylindole-fluorescence detector (HPLC-DAD-MSn-DNA-DAPI-FLD) system was developed using a combination of chromatographic, mass spectrometric and fluorescent detection techniques. 4',6-Diamidino-2-phenylindole (DAPI) specifically binds to three ATT base pairs on the DNA minor groove, and thus can be used as a fluorescent probe for screening active compounds that compete ATT sequences with DAPI. Using this system, 21 of 58 identified or tentatively characterized compounds in FBI showed DNA-binding activities, with most of the active compounds being flavone glycosides. In addition, the structure activity relationships of these active compounds suggested that conjugated planar structures are favorable for DNA-binding activities, and adjacent hydroxyl groups in flavonoids can significantly improve their activities. This is, to the best of our knowledge, the first application of DAPI as a fluorescent probe for the screening of DNA-binding active compounds in complex samples. (C) 2015 Elsevier B.V. All rights reserved.Beijing Natural Science Foundation [7142088]SCI(E)[email protected]
Heat-stable enterotoxins of enterotoxigenic Escherichia coli and their impact on host immunity
No full textEnterotoxigenic Escherichia coli (ETEC) are an important diarrhea-causing pathogen and are regarded as a global threat for humans and farm animals. ETEC possess several virulence factors to infect its host, including colonization factors and enterotoxins. Production of heat-stable enterotoxins (STs) by most ETEC plays an essential role in triggering diarrhea and ETEC pathogenesis. In this review, we summarize the heat-stable enterotoxins of ETEC strains from different species as well as the molecular mechanisms used by these heat-stable enterotoxins to trigger diarrhea. As recently described, intestinal epithelial cells are important modulators of the intestinal immune system. Thus, we also discuss the impact of the heat-stable enterotoxins on this role of the intestinal epithelium and how these enterotoxins might affect intestinal immune cells. Finally, the latest developments in vaccination strategies to protect against infections with ST secreting ETEC strains are discussed. This review might inform and guide future research on heat-stable enterotoxins to further unravel their molecular pathogenesis, as well as to accelerate vaccine design
Rapid screening and identification of compounds with DNA-binding activity from Folium Citri Reticulatae using on-line HPLC-DAD-MSn coupled with a post column fluorescence detection system
No full textTo study the interactions between natural compounds and deoxyribonucleic acid (DNA), a method has been established combining a high-performance liquid chromatography-diode array detector-multi-stage mass spectrometer with a fluorescence detector (HPLC-DAD-MSn-FLD). The FLD was used to monitor fluorescence intensity of the ethidium bromide-DNA (EB-DNA) complex when a compound separated by HPLC was introduced. This novel method was used to simultaneously obtain the HPLC fingerprint, UV spectra, MSn fragments and DNA-binding activity profile of various components in Folium Cirri Reticulatae. As a result, 35 compounds were identified, of which 25 were found in the extract of Folium Citri Reticulatae for the first time, and 33 compounds showed DNA-binding activities, with the most active being feruloylhexaric and p-coumaroylhexaric acids. In addition, the precision, stability and reproducibility of this method were validated by two positive controls, quercetin and hesperidin. This new on-line method is accurate, precise and reliable for further high-throughput screening of DNA-binding compounds from food samples and other complex matrices. (C) 2015 Elsevier Ltd. All rights reserved.National Science and Technology Major Project: Safety Testing Technology of the New Drug of TCM and the Standard Research [2014ZX09304307-001-011]SCI(E)[email protected]; [email protected]; [email protected]
Adaptive changes in chlorophyll content and photosynthetic features to low light in Physocarpus amurensis Maxim and Physocarpus opulifolius “Diabolo”
No full textThe present study aims to investigate the differences in leaf pigment content and the photosynthetic characteristics under natural and low light intensities between the Chinese native Physocarpus amurensis Maxim and the imported Physocarpus opulifolius “Diabolo” from North America. We aim to discuss the responses and the adaptive mechanism of these two cultivars of Physocarpus to a low light environment. The results show that the specific leaf area (SLA) and the chlorophyll content were significantly increased in the leaves of both Physocarpus cultivars in response to a low light intensity, and the SLA and chlorophyll content were higher in the leaves of low light-treated P. opulifolius “Diabolo” compared with the leaves of low light-treated P. amurensis Maxim. Moreover, the content of anthocyanin was markedly reduced in the leaves of P. opulifolius “Diabolo” under low light intensity, which allowed for a greater capacity of photon capture under the low light condition. Under natural light, the photosynthetic carbon assimilation capacity was greater in the leaves of P. amurensis Maxim compared with the leaves of P. opulifolius “Diabolo” that were rich with anthocyanin. However, in response to low light, AQY, Pmax, LCP and LSP decreased to a lesser extent in the leaves of P. opulifolius “Diabolo” compared with the leaves of P. amurensis Maxim. These results suggest that P. opulifolius “Diabolo” exhibits a greater ability in adaption to low light, and it is probably related to the relatively higher chlorophyll content and the smaller SLA in the leaves of P. opulifolius “Diabolo.” In addition, the low light intensity resulted in a reduced photochemical activity of photosystem (PS) II in the leaves of both Physocarpus, as evidenced by increased values of the relative variable fluorescence at point J and point I on the OJIP curve. This result suggests that the electron acceptor in PS II was the major responsive site to the low light stress in the leaves of both Physocarpus cultivars, and that the low light intensity significantly inhibited electron transfer on the acceptor side of PS II and reduced the activity of the oxygen-evolving complex (OEC) in the leaves of both Physocarpus cultivars. The PS II function in P. opulifolius “Diabolo” was higher than that in P. amurensis Maxim in response to low light. Under low light, the composition of photosynthetic pigments was altered in the leaves of P. opulifolius “Diabolo” in order to maintain a relatively high activity of primary photochemical reactions, and this is the basis of the greater photosynthetic carbon assimilation capacity and one of the main reasons for the better shade-tolerance in P. opulifolius “Diabolo.
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