Facile Use of Silver Nanoparticles-Loaded Alumina/Silica in Nanofluid Formulations for Enhanced Catalytic Performance toward 4-Nitrophenol Reduction.

The introduction of toxic chemicals into the environment can result in water pollution leading to the degradation of biodiversity as well as human health. This study presents a new approach of using metal oxides (Al2O3 and SiO2) modified with a plasmonic metal (silver, Ag) nanoparticles (NPs)-based nanofluid (NF) formulation for environmental remediation purposes. Firstly, we prepared the Al2O3 and SiO2 NFs of different concentrations (0.2 to 2.0 weight %) by ultrasonic-assisted dispersion of Al2O3 and SiO2 NPs with water as the base fluid. The thermo-physical (viscosity, activation energy, and thermal conductivity), electrical (AC conductivity and dielectric constant) and physical (ultrasonic velocity, density, refractive index) and stability characteristics were comparatively evaluated. The Al2O3 and SiO2 NPs were then catalytically activated by loading silver NPs to obtain Al2O3/SiO2@Ag composite NPs. The catalytic reduction of 4-nitrophenol (4-NP) with Al2O3/SiO2@Ag based NFs was followed. The catalytic efficiency of Al2O3@Ag NF and SiO2@Ag NF, for the 4-NP catalysis, is compared. Based on the catalytic rate constant evaluation, the catalytic reduction efficiency for 4-NP is found to be superior for 2% weight Al2O3@Ag NF (92.9 × 10-3 s-1) as compared to the SiO2@Ag NF (29.3 × 10-3 s-1). Importantly, the enhanced catalytic efficiency of 2% weight Al2O3@Ag NF for 4-NP removal is much higher than other metal NPs based catalysts reported in the literature, signifying the importance of NF formulation-based catalysis.

Effect of PVP-Capped ZnO Nanoparticles with Enhanced Charge Transport on the Performance of P3HT/PCBM Polymer Solar Cells.

We attempted surface modification in ZnO nanoparticles (NPs) synthesized by the sol-gel process with polyvinyl pyrrolidone (PVP) applied to bulk-heterojunction polymer solar cells (PSCs) as an electron transport layer (ETL). In general, ZnO NPs have trap sites due to oxygen vacancies which capture electrons and degrade the performance of the PSCs. Devices with six different PVP:Zn ratios (0.615 g, 1.230 g, 1.846 g, 2.460 g, 3.075 g, and 3.690 g) were fabricated for surface modification, and the optimized PVP:Zn ratio (2.460 g) was found for PSCs based on P3HT/PCBM. The power conversion efficiency (PCE) of the fabricated PSCs with PVP-capped ZnO exhibited a significant increase of approximately 21% in PCE and excellent air-stability as compared with the uncapped ZnO-based PSCs.

Employing PCBTDPP as an Efficient Donor Polymer for High Performance Ternary Polymer Solar Cells.

A compatible low-bandgap donor polymer (poly[N-90-heptadecanyl-2,7carbazole-alt-3,6-bis(thiophen-5-yl)-2,5-dioctyl-2,5-dihydropyrrolo [3,4] pyrrole-1,4-dione], PCBTDPP) was judicially introduced into the archetypal poly(3-hexylthiophene):[6,6]-phenyl-C61-butyric acid methyl ester (P3HT:PC61BM) photoactive system to fabricate highly efficient ternary based bulk heterojunction polymer solar cells (PSCs). The PCBTDPP ternary-based PSC with optimal loading (0.2 wt.%) displayed outstanding performance with a champion power conversion efficiency (PCE) of 5.28% as compared to the PCE (4.67%) for P3HT:PC61BM-based PSC (reference). The improved PCE for PCBTDPP ternary-based PSC can be mainly attributed to the incorporation of PCBTDPP into P3HT:PC61BM that beneficially improved the optical, morphological, electronic, and photovoltaic (PV) performance. This work instills a rational strategy for identifying components (donor/acceptor (D/A) molecules) with complementary beneficial properties toward fabricating efficient ternary PSCs.

Uncooled Short-Wave Infrared Sensor Based on PbS Quantum Dots Using ZnO NPs.

Shortwave infrared (SWIR) sensors have attracted interest due to their usefulness in applications like military and medical equipment. SWIR sensors based on various materials are currently being studied. However, most SWIR detectors need additional optical filters and cooling systems to detect specific wavelengths. In order to overcome these limitations, we proposed a solution processed SWIR sensor that can operate at room temperature using lead chloride (PbS) QDs as a photoactive layer. Additionally, we adapted zinc oxide (ZnO) nanoparticles (NPs) as an electron transport layer (ETL) to improve the sensitivity of a PbS SWIR sensor. In this study, PbS SWIR sensors with and without a ZnO NPs layer were fabricated and their current-voltage (I-V) characteristics were measured. The on/off ratio of the PbS SWIR sensor with ZnO NPs was 2.87 times higher than that of the PbS SWIR sensor without ZnO NPs at the maximum current difference. The PbS SWIR sensor with ZnO NPs showed more stable current characteristics than that without ZnO NPs because of the ZnO NPs' high electron mobility and proper lowest unoccupied molecular orbital (LUMO) level.

Improving Air-Stability and Performance of Bulk Heterojunction Polymer Solar Cells Using Solvent Engineered Hole Selective Interlayer.

In bulk heterojunction polymer solar cells (BHJ-PSCs), poly(3,4-ethylenedioxythiophene) doped with poly(styrene sulfonate) (PEDOT:PSS) is the most commonly used hole selective interlayer (HSIL). However, its acidity, hygroscopic nature, and the use of indium tin oxide (ITO) etching can degrade the overall photovoltaic performance and the air-stability of BHJ-PSCs. Solvent engineering is considered as a facile approach to overcome these issues. In this work, we engineered the HSIL using ethanol (ET) treated PEDOT:PSS to simultaneously enhance the photovoltaic performance properties and air-stability of the fabricated devices. We systematically investigated the influence of ET on the microstructural, morphological, interfacial characteristics of modified HSIL and photovoltaic characteristics of BHJ-PSCs. Compared with the BHJ-PSC with pristine PEDOT:PSS, a significant enhancement of power conversion efficiency (~17%) was witnessed for the BHJ-PSC with PEDOT:PSS-ET (v/v, 1:0.5). Consequently, the BHJ-PSC with PEDOT:PSS-ET (v/v, 1:0.5) as HSIL exhibited remarkably improved air-stability.

Improving Photovoltaic Properties of P3HT:IC60BA through the Incorporation of Small Molecules.

We investigated the role of a functional solid additive, 2,3-dihydroxypyridine (DHP), in influencing the optoelectronic, morphological, structural and photovoltaic properties of bulk-heterojunction-based polymer solar cells (BHJ PSCs) fabricated using poly(3-hexylthiophene): indene-C60 bisadduct (P3HT:IC60BA) photoactive medium. A dramatic increase in the power conversion efficiency (~20%) was witnessed for the BHJ PSCs treated with DHP compared to the pristine devices. A plausible explanation describing the alignment of pyridine moieties of DHP with the indene side groups of IC60BA is presented with a view to improving the performance of the BHJ PSCs via improved crystalline order and hydrophobicity changes.

Functional solid additive modified PEDOT:PSS as an anode buffer layer for enhanced photovoltaic performance and stability in polymer solar cells.

Poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) is most commonly used as an anode buffer layer in bulk-heterojunction (BHJ) polymer solar cells (PSCs). However, its hygroscopic and acidic nature contributes to the insufficient electrical conductivity, air stability and restricted photovoltaic (PV) performance for the fabricated PSCs. In this study, a new multifunctional additive, 2,3-dihydroxypyridine (DOH), has been used in the PEDOT: PSS buffer layer to obtain modified properties for PEDOT: PSS@DOH and achieve high PV performances. The electrical conductivity of PEDOT:PSS@DOH films was markedly improved compared with that of PEDOT:PSS. The PEDOT:PSS@DOH film exhibited excellent optical characteristics, appropriate work function alignment, and good surface properties in BHJ-PSCs. When a poly(3-hexylthiohpene):[6,6]-phenyl C61-butyric acid methyl ester blend system was applied as the photoactive layer, the power conversion efficiency of the resulting PSCs with PEDOT:PSS@DOH(1.0%) reached 3.49%, outperforming pristine PEDOT:PSS, exhibiting a power conversion enhancement of 20%. The device fabricated using PEDOT:PSS@DOH (1.0 wt%) also exhibited improved thermal and air stability. Our results also confirm that DOH, a basic pyridine derivative, facilitates adequate hydrogen bonding interactions with the sulfonic acid groups of PSS, induces the conformational transformation of PEDOT chains and contributes to the phase separation between PEDOT and PSS chains.

Analysis of genetic variation of porcine reproductive and respiratory syndrome virus (PRRSV) isolates in Central China.

Porcine reproductive and respiratory syndrome virus (PRRSV) is an epidemic etiology in pigs of all ages causing reproductive failure and respiratory manifestation. PRRSV has been circulating in Chinese pig farms for almost 20 years. The aim of the present study was to fully understand the extent of the genetic diversity and molecular characteristics of PRRSVs in Central China. A strain of PRRSV isolated from a recent outbreak farm in Hunan province in Central China, designated HUN-2014, was sequenced and analyzed with 39 other PRRSVs from 1998 to 2014 in Central China. Comparative results of genomic sequences revealed that all 40 PRRSVs belonged to the North American genotype (NA genotype) and shared 88.8-99.0% homology. Phylogenetic analysis showed three subgenotypes, namely conventional PRRSV (C-PRRSV), specially mutant PRRSV (S-PRRSV) and highly pathogenic PRRSV (HP-PRRSV), in all 40 PRRSVs. Moreover, comparative analysis of amino acid (AA) sequences of NSP2, GP3, GP5 and ORF5a revealed the main evolution trend of PRRSVs in Central China from 1998 to 2014, which was from C-PRRSV to HP-PRRSV, accompanied by different evolving directions to S-PRRSV. In conclusion, both the major evolutionary trend and special features of genetic variation should be emphasized as theoretical basis for development of new vaccines and control strategies for PRRS.

Molecular cloning and sequence analysis of prion protein gene in Xiji donkey in China.

Prion diseases are a group of human and animal neurodegenerative disorders caused by the deposition of an abnormal isoform prion protein (PrP(Sc)) encoded by a single copy prion protein gene (PRNP). Prion disease has been reported in many herbivores but not in Equus and the species barrier might be playing a role in resistance of these species to the disease. Therefore, analysis of genotype of prion protein (PrP) in these species may help understand the transmission of the disease. Xiji donkey is a rare species of Equus not widely reared in Ningxia, China, for service, food and medicine, but its PRNP has not been studied. Based on the reported PrP sequence in GenBank we designed primers and amplified, cloned and sequenced the PRNP of Xiji donkey. The sequence analysis showed that the Xiji donkey PRNP was consisted of an open reading frame of 768 nucleotides encoding 256 amino acids. Amino acid residues unique to donkey as compared with some Equus animals, mink, cow, sheep, human, dog, sika deer, rabbit and hamster were identified. The results showed that the amino acid sequence of Xiji donkey PrP starts with the consensus sequence MVKSH, with almost identical amino acid sequence to the PrP of other Equus species in this study. Amino acid sequence analysis showed high identity within species and close relation to the PRNP of sika deer, sheep, dog, camel, cow, mink, rabbit and hamster with 83.1-99.7% identity. The results provided the PRNP data for an additional Equus species, which should be useful to the study of the prion disease pathogenesis, resistance and cross species transmission.

Investigation of the effect of Mycobacterium bovis infection on bovine neutrophils functions.

Bovine tuberculosis is a disease in cattle caused by infection with Mycobacterium bovis. The disease has posed significant economic losses and remains a public health hazard worldwide. Interactions between M. bovis and bovine macrophages have been extensively characterized in various studies, while similar analyses in neutrophils, which are one of the other types of white blood cells in mammals, were often overlooked. Neutrophils provide defense against all microbes and can present a diverse collection of antimicrobial molecules, which play an important role in the control of tuberculosis progression. Much of the available data about the involvement of neutrophils in the killing M. bovis is controversial. In this study, we assessed the effect of in vitro infection with M. bovis on some parameters of neutrophils functions including phenotypic changes, apoptosis rate and inflammatory cytokines production. Our results demonstrated that phagocytosis of M. bovis activated and enhanced bovine neutrophils functions as well as initialed their defense mechanism, but failed to eliminate the mycobacteria. Moreover, autophagy might get involved in the defense infection process functioning as a protective mechanism, and inducible-autophagy by lipopolysaccharides stimulation and starvation treatment could efficiently reverse the inability of neutrophils for killing M. bovis, suggesting a potential target for anti-mycobacterial drug-therapy.

Expression pattern of interferon-inducible transcriptional genes in neutrophils during bovine tuberculosis infection.

Mycobacterium bovis, the classical causative agent of bovine tuberculosis (BTB), infects animals of agricultural importance and other mammals, including humans. Neutrophils are one of the first lines of defense against all microbes and produce a diverse collection of antimicrobial molecules, which play an important role in the early control of tuberculosis progression. An interferon (IFN)-inducible neutrophil-driven blood transcriptional signature that consisted of both IFN-γ and type I IFN-α/ß signaling has been identified in human tuberculosis, supporting a role for neutrophils in the pathogenesis of tuberculosis disease. However, it is unknown whether bovine neutrophils play a similar role during M. bovis infection. Thus, we assessed the expression levels of ten IFN-inducible transcriptional genes in neutrophils from healthy cattle stimulated by M. bovis and neutrophils isolated from three groups of cattle of different infection status, and in addition, examined the changes in the expression of myeloperoxidase (MPO) and pentraxin-related protein pentraxin-inducible protein (PTX3) genes during bovine tuberculosis infection. Our results demonstrated a specific expression pattern of IFN-inducible transcriptional genes and MPO and PTX3 genes in neutrophils during bovine tuberculosis infection. The observed expression pattern provides a potential diagnostic tool, which may have implications for vaccine and therapeutic development to combat the bovine tuberculosis epidemic.

Immune responses in mice vaccinated with a suicidal DNA vaccine expressing the hemagglutinin glycoprotein from the peste des petits ruminants virus.

Peste des petits ruminants (PPR), an acute and highly contagious disease, affects sheep, goats, and some small ruminants. The hemagglutinin (H) glycoprotein of the PPR virus (PPRV) is considered important for inducing protective immune responses. In this study, a suicidal DNA vaccine based on the Semliki Forest virus (SFV) replicon was constructed and tested for its ability to induce immunogenicity in a mouse model. For this, the H gene of PPRV was cloned and inserted into pSCA1, an SFV replicon vector. The resultant plasmid named pSCA1-H was then transfected into BHK-21 cells following which the antigenicity of the expressed protein was confirmed by Western blotting and immunofluorescence. The pSCA1-H plasmid was then injected intramuscularly into BALB/c mice thrice at 2-week intervals. To evaluate the immunogenicity of pSCA1-H, specific antibodies and neutralizing antibodies against PPRV-H were measured using an indirect enzyme-linked immunosorbent assay and a microneutralization test, respectively. Cell-mediated immune responses were also examined using a lymphocyte proliferation assay. The results showed that pSCA1-H could express the H protein in BHK-21 cells. Specific antibodies, neutralizing antibodies, and lymphocyte proliferation responses were all induced in mice. Thus, this suicidal DNA vaccine could be a promising new approach for vaccine development against PPR.

PP2 and piceatannol inhibit PrP106-126-induced iNOS activation mediated by CD36 in BV2 microglia.

Prion diseases are a group of transmissible fatal neurodegenerative disorders of humans and animals, including bovine spongiform encephalopathy, scrapie, and Creutzfeldt-Jakob disease. Microglia, the resident macrophages of the central nervous system, are exquisitely sensitive to pathological tissue alterations, altering their morphology and phenotype to adopt a so-called activated state and perform immunological functions in response to pathophysiological brain insults. Although recent findings have provided valuable insights into the role microglia play in the proinflammatory events observed in prion, the intracellular signaling molecules responsible for the initiation of these responses remain to be elucidated. It seems that microglial activation involve PrP106-126 binding and the activation of cell surface immune and adhesion molecules such as CD36 and integrins, with the subsequent recruitment of Src family tyrosine kinases such as Fyn, Lyn, and Syk kinases. In the present study, we show that CD36 is involved in PrP106-126-induced microglial activation and that PP2 and piceatannol (Pic) can abrogate neurotoxic prion peptides-induced inducible nitric oxide synthase activation in microglia. These findings unveil a previously unrecognized role of PP2 and Pic as Src family kinase Fyn and the tyrosine kinase Syk inhibitor involved in neurotoxic prion peptides-microglia interactions, thus providing new insights into mechanisms underlying the activation of microglia by neurotoxic prion peptides.

Recombinant adenovirus expressing F and H fusion proteins of peste des petits ruminants virus induces both humoral and cell-mediated immune responses in goats.

Peste des petits ruminants (PPR) is an acute and contagious disease of some small ruminants caused by peste des petits ruminants virus (PPRV). Fusion (F) protein and hemagglutinin (H) protein are two glycoproteins of PPRV that might induce a protective immune response. In this study, three replication-defective recombinant adenoviruses were constructed and the immunogenicity was evaluated in goats (the natural host). The recombinant adenoviruses (rAds) expressing F, H, and F-H fusion protein were named rAd-F, rAd-H, and rAd-F-H, respectively. In vitro, the proteins expressed in AAV-293 cells infected with different rAds were identified by Western blotting and immunofluorescence. The results showed that the proteins could be expressed in vitro. Three groups of goats (6 goats per group) were inoculated subcutaneously twice at 3-week intervals with the rAds. As negative controls, two additional groups were inoculated with wild-type adenovirus (wtAd) or PBS. In vivo, goats immunized with the rAds developed PPRV-specific virus neutralizing antibody (VNA) by 3 weeks after primary immunization. Moreover, the seroconversions were maintained for approximately 21 weeks after primary immunization. Stronger lymphocyte proliferation responses were induced in goats immunized with the three rAds than in the negative controls (P<0.05). Notably, goats inoculated with rAd-F-H developed significantly higher VNA titers (P<0.05) and stronger cell-mediated immune responses than did goats inoculated with rAd-F or rAd-H alone. The results suggest that the three rAds might be attractive candidate differentiating infected from vaccinated animals (DIVA) vaccines for preventing PPRV infection. Notably, the rAd-F-H expressing F-H fusion protein is likely the most potent candidate of the rAds.

Complete genome comparison of duck hepatitis virus type 1 parental and attenuated strains.

Two complete duck hepatitis virus type 1 (DHV-1) genomes, strain SY5 and its chicken embryos passage descendent vaccine strain ZJ-A, were compared and analyzed in order to identify possible sites of attenuation. Of the 205 nucleotide changes, 22 resulted in sense mutations, 174 produced nonsense mutations. Besides, there are 7 consistent nucleotides substitutions in 5'UTR and 2 in 3'UTR. Three of these 22 sense mutations resided in VP0, 6 exists in VP1, one exists in VP3, 3 exists in 2A2, 3 exists in 2C, one was detected in 3B and 5 was in 3D. These results suggested that VP0, VP1, 3D, and 5'/3'UTR may contribute to the attenuation of DHV-1 in chicken/duck/embryos. The results provide a genetic basis for future manipulation of a DHV-1 infectious clone.

Cloning and polymorphism analysis of prion protein gene in domestic bactrian camel in China.

Up to now, little is known about the prion protein gene (PRNP) of domestic bactrian camels, and no polymorphisms of the bactrian camel PRNP have been analyzed or reported. In this study, we cloned and analyzed the PRNP sequences of 89 domestic bactrian camels. The results showed that the amino acid sequence of bactrian camel PrP starts with the consensus sequence MVKSH, with almost identical amino acid sequence to the PrP of dromedary camels. A four octapeptide PHGGGWGQ repeat region follows a nonapeptide (PQGGGGWGQ) in the N-terminal of deduced amino acid sequence from residues 54 to 95. Polymorphisms of PRNP in both species of camels were observed in codons 16(A→V), 17(M→T), 120(N→S), 176(R→K), 215(I→V), 234(S→Y), 237(Y→S), and 239(Q→G) by comparing with other ruminants. The PrP gene nucleotide sequence alignments of bactrian camels (HQ204566.1 and HQ204567.1) showed high identity with dromedary camel (99.2%, 99.1%), sheep (91.9%, 91.8%) and cattle (91.8%, 91.6%). This study provides valuable data for future research on susceptibility or resistance of camels to prion diseases.

Generation and evaluation of the trivalent inactivated reassortant vaccine using human, avian, and swine influenza A viruses.

Reassortant technology was used to obtain three interspecific reassortant influenza viruses using three influenza viruses of A/Puerto Rico/8/34(H1N1), A/swine/Hebei/1/2005(H3N2) and A/chicken/Guangdong/126/2002(H9N2). The high-growth reassortant strains were H9/PR8, H3/H9N2 and H1/H9N2 that contained hemagglutinin (HA) and neuraminidase (NA) genes from the inactivated parental viruses and the other 6 internal genes from the live parental viruses. The trivalent formalin-inactivated vaccine, containing H1, H3 and H9 subtype antigens from human, swine and avian influenza viruses respectively, was prepared using these reassortant viruses. Animal studies showed that the vaccine was safe and immunogenic. Two-dosing regimen of the influenza vaccine induced high titers of hemagglutination inhibiting (HI) antibodies and influenza-specific IgG antibodies without antigenic cross-interference. It protected 100% chickens from challenge of A/chicken/Guangdong/126/2002 virus and protected 100% mice against challenges with different combinations of the three infective parental viruses. These results indicated that the trivalent vaccine could offer multi-protection against multi-influenza viruses synchronously. This kind of multivalent inactivated reassortant influenza vaccine maybe enlightens the pandemic influenza preparedness as the emergency measure.

Alteration of integrin-associated protein (CD47) on experimental porcine eperythrozoonosis.

To evaluate the alteration of CD47 on RBCs of pigs infected with M. suis, we induced the experimental porcine eperythrozoonosis and collected the blood samples at the different time points. The result of analysis by flow cytometry after reaction with mouse-anti-human CD47 and caprine-anti-mouse IgG-FITC reagents indicated that the CD47 quantity on RBCs changed correlatively with the course of PE. The lowest value of M1 (percentage of the positive cells in fluorescence intensity) occurred on day 7 post inoculation at the peak of parasitemia and decreased 82% compared with the control sample. And then, the values of M1 on day 14 and 21 rised slowly but were still significantly different with the controls (p < 0.01). These suggested that the quantity of CD47 on RBCs altered progressively with the phases of the PE disease. The decrease of CD47 on RBCs maybe weaken the inhibitory CD47-SIRPalpha interaction and provide positive signals for phagocytosis of macrophages resulting in the removal of the RBCs from the circulation. In conclusion, CD47, a marker on RBCs, maybe play an important role on the mechanism of hemolysis caused by infection of M. suis.

Occurrence of avian leukosis virus subgroup J in commercial layer flocks in China.

Mortality from myeloid leukosis was observed in commercial layers from 12 farms in northern China. Affected chickens were extremely thin and dehydrated, bleeding occurred in feather follicles and claws, combs were pale and anaemic, phalanges were swollen, and many yellowish-white tumours were seen on the visceral surface of the sternum. Focal tumour cells, with spherical eosinophilic granules in the cytoplasm, were found in the liver, spleen, kidney, ovary, oviduct, lung, bone marrow, proventriculus and gut by histopathological examination. Immunohistochemical studies with a monoclonal antibody to gp85 of avian leukosis virus subgroup J (ALV-J) revealed antigen in all organs examined. Polymerase chain reaction tests using a pair of ALV-J-specific primers H5/H7 (Smith et al., 1998) produced a 545 basepair fragment. The sequence of the Polymerase chain reaction product was compared with that of the ALV-J HPRS-103 prototype strain. The identity of nucleotides and predicted amino acids was 97.4% and 96.1%, respectively. On this basis the disease in the egg-type chickens was diagnosed as an ALV-J infection. This is the first report of field cases of myeloid leukosis caused by ALV-J in commercial egg-type chickens.