218 research outputs found
Probability to produce animal vaccines in insect baculovirus expression system
The insect baculovirus expression system is a valuable tool for the production of vaccine. Many subunit vaccines have been expressed in this system. The first vaccine produced in insect cells for animal use is now in the market. In this study, we reviewed recent progress of animal’s vaccine production for different expression levels and baculovirus genome stability, characteristic features of baculovirus expression vector system (BVES), virus link particles, baculovirus expression in mammalian cell and methodology of produce subunit vaccines. This review showed that BVES is a fantastic tool for vaccine development and it has wonderful feature for future animal vaccine development.Key words: Baculovirus expression system, vaccine, subunit vaccine, DNA vaccine
A possible method for non-Hermitian and non--symmetric Hamiltonian systems
A possible method to investigate non-Hermitian Hamiltonians is suggested
through finding a Hermitian operator and defining the annihilation and
creation operators to be -pseudo-Hermitian adjoint to each other. The
operator represents the -pseudo-Hermiticity of Hamiltonians.
As an example, a non-Hermitian and non--symmetric Hamiltonian with
imaginary linear coordinate and linear momentum terms is constructed and
analyzed in detail. The operator is found, based on which, a real
spectrum and a positive-definite inner product, together with the probability
explanation of wave functions, the orthogonality of eigenstates, and the
unitarity of time evolution, are obtained for the non-Hermitian and
non--symmetric Hamiltonian. Moreover, this Hamiltonian turns out to be
coupled when it is extended to the canonical noncommutative space with
noncommutative spatial coordinate operators and noncommutative momentum
operators as well. Our method is applicable to the coupled Hamiltonian. Then
the first and second order noncommutative corrections of energy levels are
calculated, and in particular the reality of energy spectra, the
positive-definiteness of inner products, and the related properties (the
probability explanation of wave functions, the orthogonality of eigenstates,
and the unitarity of time evolution) are found not to be altered by the
noncommutativity.Comment: 15 pages, no figures; v2: clarifications added; v3: 16 pages, 1
figure, clarifications made clearer; v4: 19 pages, the main context is
completely rewritten; v5: 25 pages, title slightly changed, clarifications
added, the final version to appear in PLOS ON
An extracellular steric seeding mechanism for Eph-ephrin signaling platform assembly
Erythropoetin-producing hepatoma (Eph) receptors are cell-surface protein tyrosine kinases mediating cell-cell communication. Upon activation, they form signaling clusters. We report crystal structures of the full ectodomain of human EphA2 (eEphA2) both alone and in complex with the receptor-binding domain of the ligand ephrinA5 (ephrinA5 RBD). Unliganded eEphA2 forms linear arrays of staggered parallel receptors involving two patches of residues conserved across A-class Ephs. eEphA2-ephrinA5 RBD forms a more elaborate assembly, whose interfaces include the same conserved regions on eEphA2, but rearranged to accommodate ephrinA5 RBD. Cell-surface expression of mutant EphA2s showed that these interfaces are critical for localization at cell-cell contacts and activation-dependent degradation. Our results suggest a 'nucleation' mechanism whereby a limited number of ligand-receptor interactions 'seed' an arrangement of receptors which can propagate into extended signaling arrays
An Integrated Meta-Analysis of Two Variants in HOXA1/HOXB1 and Their Effect on the Risk of Autism Spectrum Disorders
BACKGROUND: HOXA1 and HOXB1 have been strongly posed as candidate genes for autism spectrum disorders (ASD) given their important role in the development of hindbrain. The A218G (rs10951154) in HOXA1 and the insertion variant in HOXB1 (nINS/INS, rs72338773) were of special interest for ASD but with inconclusive results. Thus, we conducted a meta-analysis integrating case-control and transmission/disequilibrium test (TDT) studies to clearly discern the effect of these two variants in ASD. METHODS AND FINDINGS: Multiple electronic databases were searched to identify studies assessing the A218G and/or nINS/INS variant in ASD. Data from case-control and TDT studies were analyzed in an allelic model using the Catmap software. A total of 10 and 7 reports were found to be eligible for meta-analyses of A218G and nINS/INS variant, respectively. In overall meta-analysis, the pooled OR for the 218G allele and the INS allele was 0.97 (95% CI = 0.76-1.25, P(heterogeneity) = 0.029) and 1.14 (95% CI = 0.97-1.33, P(heterogeneity) = 0.269), respectively. No significant association was also identified between these two variants and ASD risk in stratified analysis. Further, cumulative meta-analysis in chronologic order showed the inclination toward null-significant association for both variants with continual adding studies. Additionally, although the between-study heterogeneity regarding the A218G is not explained by study design, ethnicity, and sample size, the sensitive analysis indicated the stability of the result. CONCLUSIONS: This meta-analysis suggests the HOXA1 A218G and HOXB1 nINS/INS variants may not contribute significantly to ASD risk
CNx-modified Fe3O4 as Pt nanoparticle support for the oxygen reduction reaction
A novel electrocatalyst support material, nitrogendoped carbon (CNx)-modified Fe3O4 (Fe3O4-CNx), was synthesized through carbonizing a polypyrrole-Fe3O4 hybridized precursor. Subsequently, Fe3O4-CNx-supported Pt (Pt/Fe3O4-CNx) nanocomposites were prepared by reducing Pt precursor in ethylene glycol solution and evaluated for the oxygen reduction reaction (ORR). The Pt/Fe3O4-CNx catalysts were characterized by X-ray diffraction, Raman spectra, X-ray photoelectron spectroscopy, scanning electron microscopy, and transmission electron microscopy. The electrocatalytic activity and stability of the as-prepared electrocatalysts toward ORR were studied by cyclic voltammetry and steady-state polarization measurements. The results showed that Pt/ Fe3O4-CNx catalysts exhibited superior catalytic performance for ORR to the conventional Pt/C and Pt/C-CNx catalysts.Web of Scienc
A Chitinase from Aeromonas veronii CD3 with the Potential to Control Myxozoan Disease
Background: The class Myxosporea encompasses about 2,400 species, most of which are parasites of fish and cause serious damage in aquaculture. Due to the concerns about food safety issues and limited knowledge of Myxozoa life cycle and fish immune system, no chemicals, antibiotics or immune modulators are available to control myxozoa infection. Therefore, little can be done once Myxozoa establishment has occurred. Methodology/Principal Findings: In this paper we isolated Aeromonas veronii CD3 with significant myxospore shell valvedegrading ability from pond sediment. A 3,057-bp full-length chitinase gene was consequently cloned, and the corresponding mature, recombinant chitinase (ChiCD3) produced by Escherichia coli had substantial chitinase activity. The deduced sequence of ChiCD3 contained one catalytic domain, two chitin-binding domains, and one putative signal peptide. ChiCD3 had an optimal activity at 50uC and pH 6.0, and retained more than 50 % of its optimal activity under warm water aquaculture conditions (,30uC and pH,7.0). After incubation with ChiCD3, 38.064.8 % of the myxospores had damaged shell valves, whereas myxospores incubated with commercially available chitinases remained intact. Conclusion/Significance: This study reveals a new strategy to control myxozoan disease. ChiCD3 that has capacity to damage the shell valve of myxospores can be supplemented into fish feed and used to control Myxozoa-induced disease
Differential Expression of Rubisco in Sporophytes and Gametophytes of Some Marine Macroalgae
Rubisco (ribulose-1, 5-bisphosphate carboxylase/oxygenase), a key enzyme of photosynthetic CO2 fixation, is one of the most abundant proteins in both higher plants and algae. In this study, the differential expression of Rubisco in sporophytes and gametophytes of four seaweed species — Porphyra yezoensis, P. haitanensis, Bangia fuscopurpurea (Rhodophyte) and Laminaria japonica (Phaeophyceae) — was studied in terms of the levels of transcription, translation and enzyme activity. Results indicated that both the Rubisco content and the initial carboxylase activity were notably higher in algal gametophytes than in the sporophytes, which suggested that the Rubisco content and the initial carboxylase activity were related to the ploidy of the generations of the four algal species
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Soil pH effects on the interactions between dissolved zinc, non-nano- and nano-ZnO with soil bacterial communities
Zinc oxide nanoparticles (ZnO NPs) are used in an array of products and processes, ranging from personal care products to antifouling paints, textiles, food additives, antibacterial agents and environmental remediation processes. Soils are an environment likely to be exposed to manmade nanoparticles due to the practice of applying sewage sludge as a fertiliser or as an organic soil improver. However, understanding on the interactions between soil properties, nanoparticles and the organisms that live within soil is lacking, especially with regards to soil bacterial communities. We studied the effects of nanoparticulate, non-nanoparticulate and ionic zinc (in the form of zinc chloride) on the composition of bacterial communities in soil with a modified pH range (from pH 4.5 to pH 7.2). We observed strong pH dependent effects on the interaction between bacterial communities and all forms of zinc, with the largest changes in bacterial community composition occurring in soils with low and medium pH levels (pH 4.8 and 5.9). The high pH soil (pH 7.2) was less susceptible to the effects of zinc exposure. At the highest doses of zinc (2500 mg/kg dw soil) both nano and non-nano particulate zinc applications elicited a similar response in the soil bacterial community, and this differed significantly to the ionic zinc salt treatment. The results highlight the importance of considering soil pH in nanotoxicology studies, although further work is needed to determine the exact mechanisms controlling the toxicity and fate and interactions of nanoparticles with soil microbial communities
Copy Number Variation in CNP267 Region May Be Associated with Hip Bone Size
Osteoporotic hip fracture (HF) is a serious global public health problem associated with high morbidity and mortality. Hip bone size (BS) has been identified as one of key measurable risk factors for HF, independent of bone mineral density (BMD). Hip BS is highly genetically determined, but genetic factors underlying BS variation are still poorly defined. Here, we performed an initial genome-wide copy number variation (CNV) association analysis for hip BS in 1,627 Chinese Han subjects using Affymetrix GeneChip Human Mapping SNP 6.0 Array and a follow-up replicate study in 2,286 unrelated US Caucasians sample. We found that a copy number polymorphism (CNP267) located at chromosome 2q12.2 was significantly associated with hip BS in both initial Chinese and replicate Caucasian samples with p values of 4.73E-03 and 5.66E-03, respectively. An important candidate gene, four and a half LIM domains 2 (FHL2), was detected at the downstream of CNP267, which plays important roles in bone metabolism by binding to several bone formation regulator, such as insulin-like growth factor-binding protein 5 (IGFBP-5) and androgen receptor (AR). Our findings suggest that CNP267 region may be associated with hip BS which might influence the FHL2 gene downstream
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