427 research outputs found
Induction of Cellular Immune Response by DNA Vaccine Coexpressing E. acervulina 3-1E Gene and Mature CHIl-15 Gene
We previously reported that the chimeric DNA vaccine pcDNA-3-1E-linker-mChIL-15, fused through linking Eimeria acervulina 3-1E encoding gene and mature chicken IL-15 (mChIL-15) gene with four flexible amino acid SPGS, could significantly offer protection against homologous challenge. In the present study, the induction of cellular immune response induced by the chimeric DNA vaccine pcDNA-3-1E-linker-mChIL-15 was investigated. Spleen lymphocyte subpopulations were characterized by flow cytometric analysis. The spleen lymphocyte proliferation assays were measured by 3-[4,5-dimethylthiazol-2-y1]-2,5-diphenyltetrazolium bromide (MTT) method. The mRNA profiles of ChIL-2 and ChIFN-γ in spleen were characterized by means of real-time PCR. Chickens immunized with pcDNA-3-1E-linker-mChIL-15 exhibited significant upregulated level of ChIL-2 and ChIFN-γ transcripts in spleen following two immunizations compared with chickens in other groups (P < 0.01). In comparison with pcDNA3.1-immunized and control groups, lymphocyte proliferation, percentage of CD8α+ cell, and levels of ChIL-2 and ChIFN-γ transcripts in the group immunized with pcDNA-3-1E-linker-mChIL-15 were significantly increased on day 6 following challenge (P < 0.05, P < 0.01, and P < 0.01, resp.). Our data suggested that the fusion antigen 3-1E-linker-mChIL-15 could be a potential candidate for E. acervulina vaccine development
Threshold fluences for conditioning, fatigue and damage effects of DKDP crystals
Conditioning, fatigue and damage characteristics on the surface of DKDP nonlinear optical crystals were studied under the
irradiation of 1064 nm (1Ï) and 355 nm (3Ï) lasers. Conditioning takes effect as laser fluence reaches the lower limit of
conditioning, 6âŒ8 J/cm2
and 4âŒ6 J/cm2
for 1064 nm and 355 nm in our experiments, respectively; further increase in laser
fluence will induce fatigue effects when fluence exceeds the âsafeâ fluence, âŒ10 J/cm2
and âŒ8 J/cm2
for 1064 nm and
355 nm laser light in the experiments; 1-on-1 damage will take place if fluence is sufficiently high, > 17 J/cm2
(1064 nm)
and 11 J/cm2
(355 nm) in our cases. In the conditioning regime, greater fluence will result in more damage-resistant DKDP
surface and increasing the number of con- ditioning laser pulses will have similar influence on damage resistance of DKDP
surface. When the laser fluence falls into the band of fatigue effects, the laser induced damage threshold (LIDT) drops with
increasing pulse number of conditioning laser incident on DKDP surface and finally stabilizes at a certain value, âsafeâ
fluence, below which DKDP surface cannot be damaged macroscopically even if a myriad of laser pulses shoot the DKDP
surface. The âsafeâ fluence is usually 60%âŒ80% of 1-on-1 LIDT. Our work will be beneficial to optimization of laser
conditioning and to provide insights into laser-induced damage in DKDP crystals
Stick-slip meta-instability of coal under uniaxial loading and AE and EMR response characteristics
Meta-instability stage is the most abundant precursory information and the most intense change stage in the process of fault stick-slip instability. In order to deeply explore the characteristics of coal meta-instability and the response law of acoustic and electrical signals in this process, the uniaxial graded loading experiments of coal samples with different prefabricated crack angles were carried out. The internal fracture source location, surface displacement field, acoustic emission and electromagnetic radiation signals of the samples were synchronously collected, and the mechanical behavior and acoustic and electrical characteristics of coal meta-instability were analyzed. The results show that: â The inclination angle of the prefabricated crack significantly affects the internal stress distribution of the loaded coal sample, and even the expansion distribution of the new cracks in the meta-instability stage. The acoustic emission count and energy have obvious responses to stress and failure. When the meta-instability is near, the acoustic emission count and energy increase sharply at the same time, and the signal proportion is close to 20%. The response characteristics can be used as the basis for judging the crack coal sample entering the meta-instability stage. ⥠After entering the meta-instability state, the electromagnetic radiation activity is the most intense, which is almost consistent with the occurrence time of stress drop. Before the main fracture occurs, the energy and amplitude of electromagnetic radiation increase sharply, and the peak energy increases first and then decreases with the increase of crack dip angle. When the crack dip angle is 45°, the electromagnetic radiation count accounts for the largest proportion of the total instability process. âą The fracture profile of the coal sample in the meta-instability stage has been basically formed. The inclination angle of the prefabricated crack has a significant impact on the duration of the meta-instability stage of the coal sample. When the inclination angle is 45°, the duration of the meta-instability stage is the longest, and when the inclination angle is 60°, the duration proportion is the shortest. The research results can be used to formulate the monitoring scheme of fault meta-instability, and the evolution and disaster of large-scale rock burst in fault structural are
On the dynamics of the South China Sea Warm Current
Author Posting. © American Geophysical Union, 2008. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Journal of Geophysical Research 113 (2008): C08003, doi:10.1029/2007JC004427.The South China Sea Warm Current (SCSWC) flows northeastward over the shelf and continental slope in the northern South China Sea (SCS). This current persists in its northeastward direction in all seasons despite the fact that the annually averaged wind stress is decisively southwestward against it. Two major mechanisms have been proposed in previous studies, one attributing it directly to the wind stress forcing within the SCS and the other to the Kuroshio intrusion through the Luzon Strait. In this study we use a simple model to demonstrate that neither of them is the leading forcing mechanism. Instead, the SCSWC is a source- and sink-driven flow induced by the Taiwan Strait Current (TSC), a year-round northward flow through the Taiwan Strait. The two previously suggested mechanisms are important but secondary. The model simulations show that the local wind stress alone would force a current in the opposite direction to the SCSWC. Blocking the Kuroshio intrusion through the Luzon Strait, on the other hand, only weakens the SCSWC. The SCSWC vanishes when the Taiwan Strait is closed in the model.This study has been supported by the U.S.
National Science Foundation (OCE-0351055), Chinaâs International Science
and Technology Cooperation Program (2006DFB21250), and Chinaâs
National Basic Research Priorities Program (2005CB422302)
First-Principles Study of the Band Gap Structure of Oxygen-Passivated Silicon Nanonets
A net-like nanostructure of silicon named silicon nanonet was designed and oxygen atoms were used to passivate the dangling bonds. First-principles calculation based on density functional theory with the generalized gradient approximation (GGA) were carried out to investigate the energy band gap structure of this special structure. The calculation results show that the indirectâdirect band gap transition occurs when the nanonets are properly designed. This band gap transition is dominated by the passivation bonds, porosities as well as pore array distributions. It is also proved that SiâOâSi is an effective passivation bond which can change the band gap structure of the nanonets. These results provide another way to achieve a practical silicon-based light source
Phosphorylated ERK is a potential predictor of sensitivity to sorafenib when treating hepatocellular carcinoma: evidence from an in vitro study
<p>Abstract</p> <p>Background</p> <p>Sorafenib is the first agent that has demonstrated an improved overall survival benefit in advanced hepatocellular carcinoma (HCC), setting a new standard for first-line treatment. However, no one has yet been able to predict sensitivity to sorafenib. Pre-treatment pERK level has been shown to be associated with favorable response to such therapy in a phase II clinical study, indicating that pERK may be a potential biomarker for treatment of HCC with sorafenib.</p> <p>Methods</p> <p>The effects of sorafenib and 5-fluorouracil (5-FU) on cell proliferation were evaluated by cell viability assays in four HCC cell lines (SMMC-7721, MHCC97-L, MHCC97-H and HCCLM6) with different metastatic potential and basal pERK expression levels. Expression levels of pERK were determined by immunocytochemical quantification together with western blot analysis, and pERK density values were also calculated. Correlation analyses were then carried out between the IC<sub>50 </sub>values of drugs and pERK density values. After basal ERK phosphorylation was down-regulated with U0126 in MHCC97-H cells, cellular responsiveness to sorafenib was assessed by cell viability assay.</p> <p>Results</p> <p>Basal pERK levels increased stepwise in cell lines in accordance with their metastatic potential. Sorafenib inhibited ERK phosphorylation in a dose-dependent manner in all four cell lines at a concentration between 5 and 20 ΌM, but the degree of inhibition was significantly different according to their basal pERK expression level (<it>P </it>< 0.0001). In contrast, no significant change was observed after 5-FU treatment. Correlation analyses between the IC<sub>50 </sub>values and pERK densities revealed that the effects of sorafenib on cell proliferation were significantly correlated with basal pERK levels (Spearman r = -0.8671, <it>P </it>= 0.0003). Resistance to 5-FU was also significantly associated with basal pERK expression in these HCC cell lines (Spearman r = 0.7832, <it>P </it>= 0.0026). After the basal ERK phosphorylation level in MHCC97-H cells was reduced with U0126, they were significantly less sensitive to sorafenib-mediated growth inhibition, with an IC<sub>50 </sub>of 17.31 ± 1.62 ΌM versus 10.81 ± 1.24 ΌM (<it>P </it>= 0.0281).</p> <p>Conclusion</p> <p>In this <it>in vitro </it>study, pERK was confirmed to be a potential biomarker predictive of sensitivity to sorafenib in treating HCC. The RAF/MEK/ERK pathway may be involved in drug resistance to traditional chemotherapy in HCC.</p
An analysis of farmers' perception of the new cooperative medical system in Liaoning Province, China
<p>Abstract</p> <p>Background</p> <p>Since 2003, the number of pilot areas of the New Rural Cooperative Medical System (NRCMS) has increased in rural China. And the major efforts have been concentrated on the enrollment of prospective members. In this study, we examined the satisfaction of the rural residents with the NRCMS as well as factors affecting their attitudes towards the NRCMS.</p> <p>Methods</p> <p>The data for this study were collected from a survey involving twenty counties in Liaoning Province. Interviews and focus groups were conducted between 10<sup>th </sup>January and 20<sup>th </sup>August 2008. A total of 2,780 people aged 18-72 were randomly selected and interviewed. Data were evaluated by nonparametric tests and ordinal regression models.</p> <p>Results</p> <p>71.6% of the study subjects were satisfied with the NRCMS. Single factor analysis showed that attitudes towards the NRCMS were influenced by gender, age, marital status, and self-rated health status. In the ordinal regression analysis, gender, age, and self-rated health status affect satisfaction (P < 0.05).</p> <p>Conclusions</p> <p>We found that a considerable proportion of farmers were satisfied with the NRCMS. Gender, age, and self-rated health status had significant effects on farmers' attitudes towards the NRCMS. The Chinese Central Government attempted to adopt active measures in the future to continuously improve the NRCMS, including initiating educational programs, building new medical facilities and increasing financial investment.</p
GPVI and GPIbα Mediate Staphylococcal Superantigen-Like Protein 5 (SSL5) Induced Platelet Activation and Direct toward Glycans as Potential Inhibitors
Background
Staphylococcus aureus (S. aureus) is a common pathogen capable of causing life-threatening infections. Staphylococcal superantigen-like protein 5 (SSL5) has recently been shown to bind to platelet glycoproteins and induce platelet activation. This study investigates further the interaction between SSL5 and platelet glycoproteins. Moreover, using a glycan discovery approach, we aim to identify potential glycans to therapeutically target this interaction and prevent SSL5-induced effects.
Methodology/Principal Findings
In addition to platelet activation experiments, flow cytometry, immunoprecipitation, surface plasmon resonance and a glycan binding array, were used to identify specific SSL5 binding regions and mediators. We independently confirm SSL5 to interact with platelets via GPIbα and identify the sulphated-tyrosine residues as an important region for SSL5 binding. We also identify the novel direct interaction between SSL5 and the platelet collagen receptor GPVI. Together, these receptors offer one mechanistic explanation for the unique functional influences SSL5 exerts on platelets. A role for specific families of platelet glycans in mediating SSL5-platelet interactions was also discovered and used to identify and demonstrate effectiveness of potential glycan based inhibitors in vitro.
Conclusions/Significance
These findings further elucidate the functional interactions between SSL5 and platelets, including the novel finding of a role for the GPVI receptor. We demonstrate efficacy of possible glycan-based approaches to inhibit the SSL5-induced platelet activation. Our data warrant further work to prove SSL5-platelet effects in viv
Study of the decay
The decay is studied
in proton-proton collisions at a center-of-mass energy of TeV
using data corresponding to an integrated luminosity of 5
collected by the LHCb experiment. In the system, the
state observed at the BaBar and Belle experiments is
resolved into two narrower states, and ,
whose masses and widths are measured to be where the first uncertainties are statistical and the second
systematic. The results are consistent with a previous LHCb measurement using a
prompt sample. Evidence of a new
state is found with a local significance of , whose mass and width
are measured to be and , respectively. In addition, evidence of a new decay mode
is found with a significance of
. The relative branching fraction of with respect to the
decay is measured to be , where the first
uncertainty is statistical, the second systematic and the third originates from
the branching fractions of charm hadron decays.Comment: All figures and tables, along with any supplementary material and
additional information, are available at
https://cern.ch/lhcbproject/Publications/p/LHCb-PAPER-2022-028.html (LHCb
public pages
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