41 research outputs found
Hemagglutinin-based polyanhydride nanovaccines against H5N1 influenza elicit protective virus neutralizing titers and cell-mediated immunity
H5N1 avian influenza is a significant global concern with the potential to become the next pandemic threat. Recombinant subunit vaccines are an attractive alternative for pandemic vaccines compared to traditional vaccine technologies. In particular, polyanhydride nanoparticles encapsulating subunit proteins have been shown to enhance humoral and cell-mediated immunity and provide protection upon lethal challenge. In this work, a recombinant H5 hemagglutinin trimer (H53) was produced and encapsulated into polyanhydride nanoparticles. The studies performed indicated that the recombinant H53 antigen was a robust immunogen. Immunizing mice with H53 encapsulated into polyanhydride nanoparticles induced high neutralizing antibody titers and enhanced CD4+ T cell recall responses in mice. Finally, the H53-based polyanhydride nanovaccine induced protective immunity against a low-pathogenic H5N1 viral challenge. Informatics analyses indicated that mice receiving the nanovaccine formulations and subsequently challenged with virus were similar to naïve mice that were not challenged. The current studies provide a basis to further exploit the advantages of polyanhydride nanovaccines in pandemic scenarios
Hemagglutinin-based polyanhydride nanovaccines against H5N1 influenza elicit protective virus neutralizing titers and cell-mediated immunity.
H5N1 avian influenza is a significant global concern with the potential to become the next pandemic threat. Recombinant subunit vaccines are an attractive alternative for pandemic vaccines compared to traditional vaccine technologies. In particular, polyanhydride nanoparticles encapsulating subunit proteins have been shown to enhance humoral and cell-mediated immunity and provide protection upon lethal challenge. In this work, a recombinant H5 hemagglutinin trimer (H5₃) was produced and encapsulated into polyanhydride nanoparticles. The studies performed indicated that the recombinant H5₃ antigen was a robust immunogen. Immunizing mice with H5₃ encapsulated into polyanhydride nanoparticles induced high neutralizing antibody titers and enhanced CD4(+) T cell recall responses in mice. Finally, the H5₃-based polyanhydride nanovaccine induced protective immunity against a low-pathogenic H5N1 viral challenge. Informatics analyses indicated that mice receiving the nanovaccine formulations and subsequently challenged with virus were similar to naïve mice that were not challenged. The current studies provide a basis to further exploit the advantages of polyanhydride nanovaccines in pandemic scenarios
The complete chloroplast genome sequence of Ardisia crispa Thunb.
Ardisia crispa (Thunb.) A. DC. belongs to the genus Ardisia (Myrsinaceae). It is a traditional medicinal plant widely used to treat inflammatory-related diseases in southern China. Here, we provide the complete chloroplast genome of A. crispa from Laibin, Guangxi, PR China using Illumina high-throughput sequencing approach. The total length of the chloroplast genome is 156,709 bp, including a large single-copy (LSC) region, a small single-copy (SSC) region, and a pair of inverted repeats IRa and IRb regions which are separated by the LSC and SSC, with lengths of 86,301 bp, 18,411 bp, and 25,999 bp, respectively. In general, 132 genes were identified, including 93 protein-coding genes, 31 transfer RNA (tRNA) genes, and eight ribosomal RNA (rRNA) genes. The overall GC content is 47.82%. Phylogenetic analysis revealed that A. crispa is close to congeneric species A. mamillata
an automatic testing approach for compiler based on metamorphic testing technique
Compilers play an important role in software development, and it is quite necessary to perform abundant testing to ensure the correctness of compilers. A critical task in compiler testing is to validate the semantic-soundness property which requires consistence between semantics of source programs and behavior of target executables. For validating this property, one main challenging issue is generation of a test oracle. Most existing approaches fall into two main categories when dealing with this issue: reference-based approaches and assertion-based approaches. All these approaches have their weakness when new programming languages are involved or test automation is required. To overcome the weakness in the existing approaches, we propose a new automatic approach for testing compiler. Our approach is based on the technique of metamorphic testing, which validates software systems via so-called "metamorphic relations". We select the equivalence-preservation relation as the metamorphic relation and propose an automatic metamorphic testing framework for compiler. We also propose three different techniques for automatically generating equivalent source programs as test inputs. Based on our approach, we developed a tool called Mettoc. Our mutation experiments show that Mettoc is effective to reveal compilers' errors in terms of the semantic-soundness property. Moreover, the empirical results also reveal that simple approaches for constructing test inputs are not weaker than complicated ones in terms of fault-detection capability. We also applied Mettoc in testing a number of open source compilers, and two real errors in GCC-4.4.3 and UCC-1.6 respectively have been detected by Mettoc. © 2010 IEEE
The complete chloroplast genome of Callicarpa macrophylla Vahl.
Callicarpa macrophylla Vahl. belongs to the family Lamiaceae. Its root is a widely used Yao Medicine (YM) to treat internal and external bleeding at the Yao minority areas in southern China. Here, we provide the complete chloroplast genome of C. macrophylla which was collected from Laibin city in Guangxi, China. The total length of the chloroplast genome is 154,141 bp, including a large single-copy (LSC) region, a small single-copy (SSC) region, and a pair of inverted repeats (IRs) regions which are separated by the LSC and SSC, with lengths of 84,904 bp, 17,839 bp, and 25,699 bp, respectively. One hundred and thirty-one genes were identified, including 89 protein-coding genes, 34 tRNA genes, and eight rRNA genes. The overall GC content is 38%. Phylogenetic analysis revealed that C. macrophylla is closely related to C. integerrima var. chinensis
Single-chromophore-based photoswitchable nanoparticles enable dual-alternating-color fluorescence for unambiguous live cell imaging
We have developed a class of spiropyran dyes and their fluorescence colors can be reversibly photoswitched from red to green, blue, or nearly dark, thus alternating between two colors. Such individual dyes emit either one color or the other but not both simultaneously. Nanoparticles enabled with these photoswitchable dyes, however, emit either one pure color or a combination of both colors because the nanoparticle fluorescence originates from multiple dyes therein. As a result, the nanoparticle shines >30 times brighter than state-of-the-art organic dyes such as fluorescein. Interestingly, these copolymer nanoparticles exhibit tunable nonspecific interactions with live cells, and nanoparticles containing properly balanced butyl acrylate and acrylamide monomers render essentially very little nonspecific binding to live cells. Decorated with HMGA1 protein, these optically switchable dual-color nanoparticles undergo endocytosis and unambiguously identify themselves from fluorescence interference including autofluorescence, thus enabling a new tool for live cell imaging
The complete chloroplast genome sequence of Clematis chinensis Osbeck
Clematis chinensis Osbeck is an important medicinal and edible plant. The complete chloroplast genome of C. chinensis Osbeck was constructed and annotated for the first time in this study. Full length of the chloroplast genome of C. chinensis Osbeck is 159,647 bp, with a large single-copy (LSC) region of 86,301 bp, a small single-copy (SSC) region of 79,536 bp, and a pair of inverted repeats IRa and IRb regions of 31,039 bp. The result of the gene annotation identified the 135 genes in the chloroplast genome, including 91 protein-coding genes, 36 tRNA genes, and eight rRNA genes. The total amount of GC is 47.82%. In the phylogenetic analysis, C. chinensis Osbeck showed the closest relationship with Clematis uncinata
Model-Based Fault Diagnosis of an Anti-Lock Braking System via Structural Analysis
The anti-lock braking system (ABS) is an essential part in ensuring safe driving in vehicles. The Security of onboard safety systems is very important. In order to monitor the functions of ABS and avoid any malfunction, a model-based methodology with respect to structural analysis is employed in this paper to achieve an efficient fault detection and identification (FDI) system design. The analysis involves five essential steps of SA applied to ABS, which includes critical faults analysis, fault modelling, fault detectability analysis and fault isolability analysis, Minimal Structural Over-determined (MSO) sets selection, and MSO-based residual design. In terms of the four faults in the ABS, they are evaluated to be detectable through performing a structural representation and making the Dulmage-Mendelsohn decomposition with respect to the fault modelling, and then they are proved to be isolable based on the fault isolability matrix via SA. After that, four corresponding residuals are generated directly by a series of suggested equation combinations resulting from four MSO sets. The results generated by numerical simulations show that the proposed FDI system can detect and isolate all the injected faults, which is consistent with the theoretical analysis by SA, and also eventually validated by experimental testing on the vehicle (EcoCAR2) ABS
Photoswitchable Nanoparticles Enable High-Resolution Cell Imaging: The PULSAR Microscopy
Beyond-diffraction-limit optical imaging of cells will reveal biological mechanisms, cellular structures, and physiological processes in nanometer scale. Harnessing the photoswitching properties of spiropyran fluorophores, we achieved nano-resolution fluorescence imaging using photo-actuated unimolecular logical switching attained reconstruction (PULSAR) microscopy. The PULSAR microscope successfully resolved nanostructures and subcellular organelles when the photoswitchable nanoparticles containing spiropyran dyes were used as the fluorescent probes