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We study the plasmonic properties of silver–silica–silver multilayer nanoshells using finite-difference time-domain methods. Silver is a weakly dissipating metal and is able to support higher order resonances compared to strongly dissipating metals like gold. We show that Fano resonances occur even in symmetric cases. Symmetry breaking via the introduction of core offset further enhances these Fano resonance peaks and leads to the appearance of higher order resonances. The optical properties of the multilayer nanoshells are explained using the plasmon hybridization theory and the results are compared to similar multilayer nanoshells with gold core and outer shell.

A differential phase error detector is inserted in the carrier loop structure for improving the dynamic performance of the loop in GNSS receiver in this paper. It is used to detect the abnormal phase jitter and amplify the adjusting increment for fast tracking. In order to avoid the differential detector amplifying noise interference in locking, fuzzy logical theory is introduced into the loop to control the amplification caused by the differential detector. Finally simulations show that the proposed design achieves high dynamic performance with effectively speeding up the tracking and widening the dynamic stress range.

The Fusarium graminearum species complex (Fg complex) consists of phylogenetically distinct species some of which cannot be discriminated based on their morphology. Their chemotypes and geographic distributions are dramatically different, and these highlight the challenges that Fusarium head blight (FHB) poses to plant disease specialists and plant breeders, thereby requiring that quarantine officials employ molecular diagnostic tools in their active surveillance programs. Molecular marker technologies play essential roles in species identification of the Fg complex, and they are being used widely to assess the genetic diversity of the clade. The utility, applicability and limitations of molecular methods for assessing the population structure and genetic diversity within the Fg complex are discussed with suitable examples. Knowledge gained from these studies will provide a baseline for monitoring changes in FHB pathogen diversity and mycotoxin potential over time, both of which are critical to the ultimate control and elimination of this economically devastating disease.

A micromachined reconfigurable metamaterial is presented, whose unit cell consists of a pair of asymmetric split-ring resonators (ASRRs); one is fixed to the substrate while the other is patterned on a movable frame. The reconfigurable metamaterial and the supporting structures (e.g., microactuators, anchors, supporting frames, etc.) are fabricated on a silicon-on-insulator wafer using deep reactive-ion etching (DRIE). By adjusting the distance between the two ASRRs, the strength of dipole–dipole coupling can be tuned continuously using the micromachined actuators and this enables tailoring of the electromagnetic response. The reconfiguration of unit cells endows the micromachined reconfigurable metamaterials with unique merits such as electromagnetic response under normal incidence and wide tuning of resonant frequency (measured as 31% and 22% for transverse electric polarization and transverse magnetic polarization, respectively). The reconfiguration could also allow switching between the polarization-dependent and polarization-independent states. With these features, the micromachined reconfigurable metamaterials may find potential applications in transformation optics devices, sensors, intelligent detectors, tunable frequency-selective surfaces, and spectral filters.

Porous crystalline SnO 2 thin films were electrodeposited from an oxygen-saturated acid aqueous solution of SnCl 2 containing different amounts of butyl rhodamine B (BRhB) at 70 °C. BRhB can not only be dissolved in the acid deposition solution due to its amidocyanogen substitute, where HCl was added to suppress hydrolysis of SnCl 2 , but also be adsorbed on the surface of SnO 2 through its carbonate substitute. Therefore, it was used as a structure-directing agent to control the growth of SnO 2 crystals and then the crystalline structure and surface morphology of the deposited film. The electrodeposited thin films show porous morphology and rutile-type SnO 2 crystalline structure due to the effects of BRhB on the growth, and these structural features can be adjusted by changing the added amount of BRhB. The SnO 2 thin film electrodeposited with addition of BRhB exhibits electrocatalytic characteristic enhancement on oxidation of phenol due to its porous structure.

DNA barcoding is a method of species identification and recognition using DNA sequence data. A tiered or multilocus method has been recommended for barcoding plant species. In this study, we sampled 196 individuals representing 9 genera and 54 species of Juglandaceae to investigate the utility of the four potential barcoding loci (rbcL, matK, trnH-psbA, and internal transcribed spacer (ITS)). Our results show that all four DNA regions are easy to amplify and sequence. In the four tested DNA regions, ITS has the most variable information, and rbcL has the least. At generic level, seven of nine genera can be efficiently identified by matK. At species level, ITS has higher interspecific p-distance than the trnH-psbA region. Difficult to align in the whole family, ITS showed heterogeneous variability among different genera. Except for the monotypic genera (Cyclocarya, Annamocarya, Platycarya), ITS appeared to have limited power for species identification within the Carya and Engelhardia complex, and have no power for Juglans or Pterocarya. Overall, our results confirmed that a multilocus tiered method for plant barcoding was applicable and practicable. With higher priority, matK is proposed as the first-tier DNA region for genus discrimination, and the second locus at species level should have enough stable variable characters.

One homochiral 1D coordination polymer [Cu(ATIBDC)(2,2′-bipy)]·3H2O·CH3OH (1) and three achiral 1D coordination polymers: [Cd(ATIBDC)(2,2′-bipy)(H2O)]·3H2O (2), [Cd(ATIBDC)(phen)(H2O)]·4H2O (3), and [Mn(ATIBDC)(phen)2]·5H2O (4) have been synthesized and characterized (H2ATIBDC=5-amino-2,4,6-triiodoisophthalic acid, 2,2′-bipy=2,2′-bipyridine, and phen=1,10-phenanthroline). Extended high dimensional network architectures are further constructed with the help of weak secondary interactions, such as hydrogen bonding, aromatic stacking, and halogen bonding (C–I…π and C–I…N/O). Complex 1 crystallizes in the monoclinic system with chiral space group P2(1) and exhibits a right-handed 21 helical chain structure. The homochirality of 1 was confirmed by CD spectrum. Interestingly, two new configurations of decameric water cluster are found in 3 and 4. The acyclic tetrameric cluster (H2O)3(CH3OH) in 1 and (H2O)4 in 2 array into highly ordered helical infinite chains. Thermal stabilities of all the complexes have been studied. Solid state fluorescent properties of the Cd(II) complexes have been explored.

Porous SnO 2 nanocrystalline thin films were successfully electrodeposited from an oxygen-saturated acid aqueous solution of SnCl 2 containing different concentrations of butyl-rhodamine B (BRhB) at 70 °C. BRhB with substitute of amidocyanogen can be dissolved in the acid deposition solution, where HCl was added to suppress hydrolysis of SnCl 2 . So it was used as a structure-directing agent to promote the crystal growth of SnO 2 . The formed porous morphology and tetragonal rutile crystalline structure of the electrodeposited thin films were controlled by the addition of BRhB with different amounts.

A novel low temperature method was used to prepare the mesoporous carbon (MC) counter electrode (CE) on indium-doped tin oxide coated polyethylene naphthalate (ITO-PEN) for flexible dye-sensitized solar cells (DSSCs). The obtained flexible MC CEs with carbon loading of 280 μg cm −2 were characterized by SEM, XRD and electrochemical impedance. The light-to-electricity conversion efficiency of the DSSC fabricated with the prepared flexible MC CE was 86% of that of DSSC based on the decomposited Pt CE.

TiO 2 colloid was prepared by the sol–gel method and was bladed on transparent conduction glass to made nanoporous electrode. The impedance performance of TiO 2 electrode was studied at various bias potential. A simplified equivalent circuit was proposed to investigate the charge transport impedance of TiO 2 film and good fitting results were obtained.

Laser interference lithography (LIL) has the capability to fabricate large-area microstructures on the photoresist with only a couple of minutes’ exposure and development. In this study, LIL was adopted to fabricate micro/nanostructures in quartz by combining the following dry-etching process either reactive ion etching (RIE) or inductively coupled plasma (ICP). A layer of gold film was coated on the quartz to act as a hard mask during the dry-etching process. A microhole array in quartz with a thin gold film covered on the surface was fabricated when choosing RIE. Each hole in the microhole array was surrounded with gold nanoparticle capped silica (Au/SiO2) cones when using ICP instead of RIE. This is due to the thin gold film that serves as the mask for creating the surface roughness required for creating the silica cone structure.

Intravenous administration of recombinant tissue plasminogen activator (rtPA) is known as the only approved treatment for acute ischemic stroke. However, it is still controversial whether acute ischemic stroke patients with atrial fibrillation should receive rtPA therapy.We studied 99 patients altogether who belonged to three different groups based on the patient characteristics: (1) atrial fibrillation rtPA-treated group consisting of 22 ischemic stroke patients with atrial fibrillation treated with rtPA within 4.5 hours after the onset of stroke; (2) atrial fibrillation non-rtPA-treated group consisting of 44 acute ischemic stroke patients with atrial fibrillation matching in age and baseline National Institutes of Health Stroke Scale (NIHSS); (3) the non-atrial fibrillation rtPA-treated group consisting of 33 patients without atrial fibrillation treated with rtPA.The median time for the administration of rtPA was 199.6 +/- 50.0 minutes. More patients had favorable outcomes (90 day modified Rankin Scale 0-1) in the atrial fibrillation rtPA-treated group than the atrial fibrillation non-rtPA-treated group (36.4 versus 13.6%; odds ratio=2.667; 95% confidence interval: 1.056-6.735; p=0.033). The mortality at day 90 was lower in the rtPA-treated group than the non-rtPA-treated group (18.2 versus 20.5%; p=0.827), although the incidence of symptomatic intracranial hemorrhage was higher (18.2 versus 6.8%; p=0.184). Patients in the atrial fibrillation rtPA-treated group had fewer favorable outcomes than non-atrial fibrillation rtPA-treated group (36.4 versus 51.6%; p=0.076), but their baseline NIHSS was higher (12.0 +/- 7.1 versus 9.1 +/- 7.3; p=0.161).As compared with non-rtPA-treated patients, rtPA treated within 4.5 hours after the onset of stroke significantly improved clinical outcomes in atrial fibrillation patients. Thrombolytic treatment increases intracranial hemorrhage rate but does not increase mortality.

Natural resistance of wheat against Fusarium head blight (FHB) is inadequate and new strategies for controlling the disease are required. Chitin synthases that catalyze chitin biosynthesis would be an ideal target for antifungal agents. In this study, a class I chitin synthase gene (CHS1) from Fusarium asiaticum, the predominant species of FHB pathogens on wheat in China, was functionally disrupted via Agrobacterium tumefaciens-mediated transformation. Specific disruption of the CHS1 gene resulted in a 58% reduction of chitin synthase activity, accompanied by decreases of 35% in chitin content, 22% in conidiation, and 16% in macroconidium length. The Deltachs1 mutant strain had a growth rate comparable to that of the wild-type on PDA medium but had a 35% increase in the number of nuclear cellulae and exhibited a remarkably increased sensitivity to osmosis stresses. Electron microscopy revealed substantial changes occurring in cell wall structures of the macroconidium, ascospore, and mycelium, with the most profound changes in the mycelium. Furthermore, the Deltachs1 mutant displayed significantly reduced pathogenicity on wheat spikes and seedlings. Re-introduction of a functional CHS1 gene into the Deltachs1 mutant strain restored the wild-type phenotype. These results reveal an important in vivo role played by a CHS1 gene in a FHB pathogen whose mycelial chitin could serve as a target for controlling the disease.

Background and objectives: Intravenous thrombolysis with recombinant tissue plasminogen activator within 3 hours of acute ischemic stroke onset can reduce the risk of death and severe disability. There are differences in collateral circulation, the compensatory ability of cerebral blood vessels, and brain metabolism between each patient, leading to differences in the thrombolysis time window. Thrombolysis is considered effective in patients 3 hours after onset; however, it remains controversial whether this time window should be extended. Therefore, we will employ a retrospective case analysis study using multimode computed tomography (CT) to observe the extended time window (3–9 hours after stroke onset) and to summarize its efficacy and safety in the treatment of acute ischemic stroke. Design: This is a retrospective, single-center, case-analysis clinical trial. Methods: We will retrospectively collect data from 450 patients with acute ischemic stroke who have undergone thrombolytic therapy in the Third People's Hospital of Dalian, China, from June 2008 to December 2017. The time window will be set to 3–9 hours after stroke onset. We will evaluate the effect of this extended thrombolysis time window using multimode CT. Outcome measures: The primary outcome measure is the National Institutes of Health Stroke Scale (NIHSS) score 7 days after treatment or at discharge, to evaluate the effect of thrombolysis. The secondary outcome measures are as follows: the occurrence of hemorrhagic events 24–36 hours and 7 days after treatment; NIHSS score at 2 and 24–36 hours, and at 3 and 12 months after treatment; modified Rankin scale score at 7 days after treatment or discharge, and at 3 and 12 months after treatment; vascular stenosis and infarct size 24–36 hours and 7 days after treatment; incidence of adverse reactions and deaths at 3 months after treatment; incidence of symptomatic intracranial hemorrhagic transformation during hospitalization; vital signs and laboratory measurements (blood indexes, blood glucose, blood lipids, liver and kidney functions, myocardial enzymes, blood electrolytes, and coagulation function); and electrocardiography results. Discussion: Under the guidance of multimode CT, we will extend the thrombolysis time window to 9 hours after the onset of the disease, and summarize the efficacy and adverse reactions of an extended time window for intravenous thrombolysis after acute ischemic stroke. This trial will provide objective data for the optimization of clinical diagnoses and treatment pathways for patients. Ethics and dissemination: This trial has been approved by the Medical Ethics Committee of The Third People's Hospital of Dalian, China on December 5, 2017. The study protocol will be conducted in accordance with the Declaration of Helsinki, formulated by the World Medical Association. This trial was designed in October 2017. Data collection has begun in January 2018 and will finish in October 2018. Outcome measures will be analyzed in December 2018. The results of the trial will be reported in a scientific conference or disseminated in a peer-reviewed journal. Trial registration: This trial had been registered in the Chinese Clinical Trial Registry (registration number: ChiCTR1800014368). Protocol version (1.0).

This paper elaborates on approaches of synthesis of Au and Ag nanoparticles (NPs), deposition of colloid onto glass substrate and encapsulation of NPs with silicon dioxide (SiO2) thin shell. As one important bio application of metallic nanoparticles, both solution-based and substrate-based fluorescence enhancement tests are demonstrated.

Protein plays key role in cellular processes and diseases diagnosis [1-3]. This paper reports a label-free detection of proteins through localized surface plasmon resonance (LSPR) and realized Au nanoparticles (AuNPs) immobilized on glass slide. Glass slide is first sonicated with 5% v/v glassware detergent in ultrapure water for 30 mins, and then in ultrapure water for another 30 mins. A 5% v/v aminopropyltriethoxysilane (APTES) solution in ultrapure water is prepared and the glass slide is immersed in the 5% v/v APTES solution for 20 mins. The glass slide is sonicated for 60 mins in ultrapure water. The purpose of the sonication is to remove the multi-layers of APTES which are formed on the glass surface. The silanized glass slide is immersed in AuNPs solution for 40 mins. Finally, the protein solution is added on the surface of the slide. The surface absorption of proteins induces a significant difference of environmental refractive index around the AuNPs. The shift in the wavelength of the LSPR spectra is very sensitive to the change in the surface refractive index of the nanoparticles. The shifts in the LSPR spectra are primarily determined by the volatility and refractive indices of the protein species. In this paper, the LSPR-nanobiosensor is designed and fabricated. The LSPR band responses are measured by a real-time UV–vis spectrometer with a CCD array detector. The response time of the protein–LSPR spectrum is less than 3 seconds and the response is reversible and reproducible.

Fusarium mycotoxins directly accumulated in grains during the infection of wheat and other cereal crops by Fusarium head blight (FHB) pathogens are detrimental to humans and domesticated animals. Prevention of the mycotoxins via the development of FHB-resistant varieties has been a challenge due to the scarcity of natural resistance against FHB pathogens. Various antibodies specific to Fusarium fungi and mycotoxins are widely used in immunoassays and antibody-mediated resistance in planta against Fusarium pathogens has been demonstrated. Antibodies fused to antifungal proteins have been shown to confer a very significantly enhanced Fusarium resistance in transgenic plants. Thus, antibody fusions hold great promise as an effective tool for the prevention of mycotoxin contaminations in cereal grains. This review highlights the utilization of protective antibodies derived from phage display to increase endogenous resistance of wheat to FHB pathogens and consequently to reduce mycotoxins in field. The role played by Fusarium-specific antibody in the resistance is also discussed.

Solid-state dye-sensitized solar cells based on nanocrystalline TiO2 thin film with the structures TiO2/dye/CuI/Pt and TiO2/dye/In situ CuI/CuI/Pt were developed in order to compare the use of In situ deposited CuI (In situ CuI). Porosity of the screen-printed nanoporous TiO2 thin film was enhanced by the addition of polystyrene balls. Evidence of decrease in interfacial resistance was observed by electrochemical impedance measurement for the device with In situ deposited CuI as compared to that without In situ deposited CuI as hole conductor. This was attributed to good interfacial contacts and better charge transfer between CuI and dye-sensitized TiO2 nanoparticles, which resulted in the enhancement of power conversion efficiency from 0.058 to 1.01%. Copyright © 2008 John Wiley & Sons, Ltd.

Fusarium head blight (FHB) or scab of wheat is a devastating disease in warm and humid regions at wheat-flowering periods worldwide. Natural resistance against FHB pathogens is inadequate and the development of FHB-resistant wheat cultivars has been a challenge. Expression of pathogen-specific antibodies in plants has been proposed as a strategy for crop protection. In this study, an antibody fusion protein comprising a Fusarium-specific recombinant antibody derived from chicken and an antifungal peptide from Aspergillus giganteus was expressed in wheat as a method for protecting plants against FHB pathogens. Plants expressing the antibody fusion displayed a very significantly enhanced resistance in T2 and T3 generations upon single-floret inoculation with the macroconidia of Fusarium asiaticum, the predominant species causing FHB in China, indicating a type II resistance. Spraying inoculation further revealed an enhanced type I resistance in the transgenic wheat plants. Remarkably, more grains were produced in the transgenic plants than the nontransgenic controls. Our results demonstrated that the antibody fusion protein may be used as an effective tool for the protection of crops against FHB pathogens.

The screen-printed nanoporous TiO 2 thin film was employed to fabricate dye-sensitized solid-state solar cells using CuI as hole-transport materials. The solar cell based on nanoporous TiO 2 thin film with large pores formed by the addition of polystyrene balls with diameter of 200 nm to the TiO 2 paste exhibits photovoltaic performance enhancement, which is attributed to the good contact of CuI with surface of dye-sensitized thin film due to easy penetration of CuI in the film with large pores.

The genetic diversity and pathogenicity of isolates of Fusarium graminearum and F. asiaticum isolated from wheat heads in China were examined and compared with those of isolates of F. graminearum, F. asiaticum and F. meridionale from Europe, USA and Nepal. Genetic diversity was assessed by SSCP (single strand conformation polymorphism) and AFLP (amplified fragment length polymorphism) analysis and by molecular chemotyping. SSCP analysis of the Fg16F/Fg16R PCR amplicon differentiated F. graminearum, F. asiaticum and F. meridionale and revealed three haplotypes among sequence-characterized amplified region (SCAR) type 1 F. graminearum isolates. AFLP analysis showed a high level of genetic diversity and clustered the majority of Chinese isolates in one group along with other isolates of Asian origin. The second cluster contained F. graminearum isolates from China, Europe and the USA. Of the Chinese isolates, 79% were F. asiaticum and 81% of these were of the 3-AcDON chemotype, with only 9·5% of either chemotype 15-AcDON or NIV. All the Chinese and USA isolates of F. graminearum were 15-AcDON, whereas among the isolates from Europe, 21% were NIV and 8% were 3-AcDON chemotype. No evidence was found for possible differences in aggressiveness between F. graminearum and F. asiaticum. Highly aggressive isolates were present in each region and no evidence was found for any association between aggressiveness and geographical origin or chemotype among the isolates examined. No difference was observed in pathogenicity towards wheat seedlings between Chinese isolates and those from Europe, the USA or Nepal.

A large number of isolates from the Fusarium graminearum clade representing all regions in China with a known history of Fusarium head blight (FHB) epidemics in wheat were assayed using PCR to ascertain their trichothecene mycotoxin chemotypes and associated phylogenetic species and geographical distribution. Of the 299 isolates assayed, 231 are from F. asiaticum species lineage 6, which produce deoxynivalenol and 3-acetyldeoxynivalenol (3-AcDON); deoxynivalenol and 15-acetyldeoxynivalenol (15-AcDON); and nivalenol and 4-acetylnivalenol (NIV) mycotoxins, with 3-AcDON being the predominant chemotype. Ninety-five percent of this species originated from the warmer regions where the annual average temperatures were above 15 degrees C, based on the climate data of 30 y during 1970-1999. However, 68 isolates within F. graminearum species lineage 7 consisted only of 15-AcDON producers, 59% of which were from the cooler regions where the annual average temperatures were 15 degrees C or lower. Identification of a new subpopulation of 15-AcDON producers revealed a molecular distinction between F. graminearum and F. asiaticum that produce 15-AcDON. An 11-bp repeat is present in F. graminearum within their Tri7 gene sequences but is absent in F. asiaticum, which could be directly used for differentiating the two phylogenetic species of the F. graminearum clade.

Controlling toxigenic Fusarium graminearum (FG) is challenging. A bacterial strain (S76-3, identified as Bacillus amyloliquefaciens) that was isolated from diseased wheat spikes in the field displayed strong antifungal activity against FG. Reverse-phase high performance liquid chromatography and electrospray ionization mass spectrometry analyses revealed that S76-3 produced three classes of cyclic lipopeptides including iturin, plipastatin and surfactin. Each class consisted of several different molecules. The iturin and plipastatin fractions strongly inhibited FG; the surfactin fractions did not. The most abundant compound that had antagonistic activity from the iturin fraction was iturin A (m/z 1043.35); the most abundant active compound from the plipastatin fraction was plipastatin A (m/z 1463.90). These compounds were analyzed with collision-induced dissociation mass spectrometry. The two purified compounds displayed strong fungicidal activity, completely killing conidial spores at the minimal inhibitory concentration range of 50 µg/ml (iturin A) and 100 µg/ml (plipastatin A). Optical and fluorescence microscopy analyses revealed severe morphological changes in conidia and substantial distortions in FG hyphae treated with iturin A or plipastatin A. Iturin A caused leakage and/or inactivation of FG cellular contents and plipastatin A caused vacuolation. Time-lapse imaging of dynamic antagonistic processes illustrated that iturin A caused distortion and conglobation along hyphae and inhibited branch formation and growth, while plipastatin A caused conglobation in young hyphae and branch tips. Transmission electron microscopy analyses demonstrated that the cell walls of conidia and hyphae of iturin A and plipastatin A treated FG had large gaps and that their plasma membranes were severely damaged and separated from cell walls.

The Balb/c mice were infected with Coxiella burnetii and samples of blood and major organs from the infected mice were collected on days 1 to 14 after infection. The DNAs extracted from the samples were detected by a developed real-time quantitative PCR specific for C. burnetii and high loads of C. burnetii were found in spleens, livers, and lungs, particularly in spleens. The Balb/c mice were immunized with whole cell antigen (WCA) of C. burnetii and coxiella loads in spleens of mice were assessed by the real-time quantitative PCR on day 7 after challenge with C. burnetii. The analysis suggested that phase I whole cells were excellent immunogen that elicited complete protection against coxiella infection by two-booster but not one-booster immunization. The results suggest that the combination of Balb/c model and the real-time quantitative PCR assay is a reliable and sensitive way to evaluate the efficiency of vaccines against Q fever.

The gene fragments encoding outer membrane protein 1 (P1) and heat-shock protein B (HspB) amplified from genomic DNA of Coxiella burnetii Xinqiao by PCR were inserted into prokaryotic expression vector pQE30 to construct recombinant expression plasmids pQE30/p1 and pQE30/hspB, respectively. The p1 fragment from pQE30/p1 was ligated with hspB of pQE30/hspB to construct pQE30/p1-hspB. Recombinant proteins, P1, HspB, and P1-HspB, were expressed in Escherichia coli cells transformed with pQE30/p1, pQE30/hspB, and pQE30/p1-hspB, respectively. The purified recombinant proteins and whole-cell antigen (WCA) of C. burnetii were used to immunize BALB/c mice. The antibody detection, T-cell proliferation assay, and cytokine detection demonstrated that the animals immunized with P1-HspB or WCA exhibited stronger humoral and cellular immune responses compared with animals immunized with P1 or HspB individually. Seven days after challenge of 10-fold 50% infection dose of C. burnetii, mice were euthanized and their spleens were collected. The splenic weights of mice immunized with P1-HspB or WCA were significantly lighter than that of mice immunized with P1 or HspB. By real-time PCR assay, the coxiella loads of spleens of mice immunized with P1-HspB or WCA were also significantly lower than that of mice immunized with P1 or HspB. The data from this study indicate that fusion antigen P1-HspB is a good immunogen for eliciting immunoresponses against C. burnetii, and it may be a more suitable candidate for preparing subunit vaccine against Q fever.

We report a real-time method to determine the size, i.e. diameter, and refractive index of single gold nanoparticles using an optofluidic chip, which consists of a quasi-Bessel beam optical chromatography. The tightly focused (∼ 0.5 μm) quasi-Bessel beam with low divergence (NA ∼ 0.04) was used to trap sub-100 nm gold nanoparticles within a long trapping distance of 140 μm. In the experiment, 60 to 100 nm gold nanoparticles were separated efficiently with at least 18 μm. The diameter and refractive index (real and imaginary) of single gold nanoparticles were measured at high resolutions with respect to the trapping distance, i.e. 0.36 nm/μm, 0.003/μm and 0.0016/μm, respectively. NRF (Natl Research Foundation, S’pore) Published version

Fusarium head blight (FHB) in wheat and other small grain cereals is a globally devastating disease caused by toxigenic Fusarium pathogens. Controlling FHB is a challenge because germplasm that is naturally resistant against these pathogens is inadequate. Current control measures rely on fungicides. Here, an antibody fusion comprised of the Fusarium spp.-specific recombinant antibody gene CWP2 derived from chicken, and the endochitinase gene Ech42 from the biocontrol fungus Trichoderma atroviride was introduced into the elite wheat cultivar Zhengmai9023 by particle bombardment. Expression of this fusion gene was regulated by the lemma/palea-specific promoter Lem2 derived from barley; its expression was confirmed as lemma/palea-specific in transgenic wheat. Single-floret inoculation of independent transgenic wheat lines of the T3 to T6 generations revealed significant resistance (type II) to fungal spreading, and natural infection assays in the field showed significant resistance (type I) to initial infection. Gas chromatography-mass spectrometry analysis revealed marked reduction of mycotoxins in the grains of the transgenic wheat lines. Progenies of crosses between the transgenic lines and the FHB-susceptible cultivar Huamai13 also showed significantly enhanced FHB resistance. Quantitative real-time PCR analysis revealed that the tissue-specific expression of the antibody fusion was induced by salicylic acid drenching and induced to a greater extent by F. graminearum infection. Histochemical analysis showed substantial restriction of mycelial growth in the lemma tissues of the transgenic plants. Thus, the combined tissue-specific and pathogen-inducible expression of this Fusarium-specific antibody fusion can effectively protect wheat against Fusarium pathogens and reduce mycotoxin content in grain.

Trehalose 6-phosphate synthase (TPS1) and trehalose 6-phosphate phosphatase (TPS2) are required for trehalose biosynthesis in yeast and filamentous fungi, including Fusarium graminearum. Three null mutants Δtps1, Δtps2 and Δtps1-Δtps2, each carrying either a single deletion of TPS1 or TPS2 or a double deletion of TPS1-TPS2, were generated from a toxigenic F. graminearum strain and were not able to synthesize trehalose. In contrast to its reported function in yeasts and filamentous fungi, TPS1 appeared dispensable for development and virulence. However, deletion of TPS2 abolished sporulation and sexual reproduction; it also altered cell polarity and ultrastructure of the cell wall in association with reduced chitin biosynthesis. The cell polarity alteration was exhibited as reduced apical growth and increased lateral growth and branching with increased hyphal and cell wall widths. Moreover, the TPS2-deficient strain displayed abnormal septum development and nucleus distribution in its conidia and vegetative hyphae. The Δtps2 mutant also had 62% lower mycelial growth on potato dextrose agar and 99% lower virulence on wheat compared with the wild-type. The Δtps1, Δtps2 and Δtps1-Δtps2 mutants synthesized over 3.08-, 7.09- and 2.47-fold less mycotoxins, respectively, on rice culture compared with the wild-type. Comparative transcriptome analysis revealed that the Δtps1, Δtps2 and Δtps1-Δtps2 mutants had 486, 1885 and 146 genotype-specific genes, respectively, with significantly changed expression profiles compared with the wild-type. Further dissection of this pathway will provide new insights into regulation of fungal development, virulence and trichothecene biosynthesis.

This paper reports a microfluidic nanoparticles sorting generator by using optical force and hydrodynamic forces. Nanoparticles ranges in size from 70 nm to 1 μm can be aligned and focused in the core flow stream by hydrodynamic focusing. By injecting light into the microfluidic system, the particles can be subsequently manipulated by the optical forces and liquid Stoke forces. The particles with different sizes and refractive indices can be selected by the optical forces and the drag force, flowing with different traces. It has a great potential in cell and molecule sorting and separating.

Type II myosin is required for cytokinesis/septation in yeast and filamentous fungi, including Fusarium graminearum, a prevalent cause of Fusarium head blight in China. A type II myosin gene from the Chinese F. graminearum strain 5035, isolated from infected wheat spikes, was identified by screening a mutant library generated by restriction enzyme-mediated integration. Disruption of the Myo2 gene reduced mycelial growth by 50% and conidiation by 76-fold, and abolished sexual reproduction on wheat kernels. The Δmyo2 mutants also had a 97% decrease in their pathogenicity on wheat, and mycotoxin production fell to just 3.4% of the normal level. The distribution of nuclei and septa was abnormal in the mutants, and the septal ultrastructure appeared disorganized. Time-lapse imaging of septation provided direct evidence that Myo2 is required for septum initiation and formation, and revealed the dynamic behavior of GFP-tagged Myo2 during hyphal and macroconidia development, particularly in the delimiting septum of phialides and macroconidial spores. Microarray analysis identified many genes with altered expression profiles in the Δmyo2 mutant, indicating that Myo2 is required for several F. graminearum developmental processes and biological activities.

A Whisper Gallery mode based biosensor with a micro-well array for allocation and enhancement of the output light. Fluorescent polystyrene microspheres are used for prostate-specific antigen (PSA) sensing.

The hickory genus (Carya) contains ca. 17 species distributed in subtropical and tropical regions of eastern Asia and subtropical to temperate regions of eastern North America. Previously, the phylogenetic relationships between eastern Asian and eastern North American species of Carya were not fully confirmed even with an extensive sampling, biogeographic and diversification patterns had thus never been investigated in a phylogenetic context. We sampled 17 species of Carya and 15 species representing all other genera of the Juglandaceae as outgroups, with eight nuclear and plastid loci to reconstruct the phylogeny of Carya. The phylogenetic positions of seven extinct genera of the Juglandaceae were inferred using morphological characters and the molecular phylogeny as a backbone constraint. Divergence times within Carya were estimated with relaxed Bayesian dating. Biogeographic analyses were performed in DIVA and LAGRANGE. Diversification rates were inferred by LASER and APE packages. Our results support two major clades within Carya, corresponding to the lineages of eastern Asia and eastern North America. The split between the two disjunct clades is estimated to be 21.58 (95% HPD 11.07-35.51) Ma. Genus-level DIVA and LAGRANGE analyses incorporating both extant and extinct genera of the Juglandaceae suggested that Carya originated in North America, and migrated to Eurasia during the early Tertiary via the North Atlantic land bridge. Fragmentation of the distribution caused by global cooling in the late Tertiary resulted in the current disjunction. The diversification rate of hickories in eastern North America appeared to be higher than that in eastern Asia, which is ascribed to greater ecological opportunities, key morphological innovations, and polyploidy.

To study the nerve electromyogram results by analysing the pathological characters of 4 cases diagnosed as peripheral neuropathy caused by n-hexane and arsenic.The nerve electromyogram examination and pathology data of 4 patients, who had been diagnosed as toxic chemicals peripheral neuropathy, were studied retrospectively.Two patients in this group were exposed to n-hexane, their nerve electromyogram examinations and biopsy pathology of superficial peroneal nerve indicated the peripheral neuropathy was mainly manifests the lesion of medullary sheath. Another two patients were exposed to arsenic, their nerve electromyogram examinations showed axonal degeneration associated with demyelination, and their biopsy pathology showed the peripheral neuropathy was mainly axonal degeneration.Axonal degeneration and demyelination always coexist in peripheral neuropathy caused by chemicals.

A high voltage pulse transmission line (TL) insulated by SF 6 is described which is used in high power microwave and high power pulse technology. According to requirements, we adopt compressed SF 6 gas as insulation and Polyphenylene Oxide (PPO) as support between inner and outer conductor which use corrugated structure with some depth to improve flexibility. For safety in application, stainless steel wire is used as tension component. Tests verify that attenuation of TL is 0.016dB/m when transmitting a signal with 3ns pulse width, 1kHz repetition frequency. Characteristic impedance of TL is 50Ω. Flange and transition connecter are discussed for application. In following work, breakdown strength of SF 6 gas with different pressure under pulse high voltage will be studied in order to compare to data under AC and DC situations and achieve breakdown theory of SF 6 gas under some pulse high voltage situations.

In this article, we investigate higher order (quadrupolar, octupolar, hexadecapolar, and triakontadipolar) Fano resonances generated in disk ring (DR) silver plasmonic nanostructures. We find that the higher order Fano resonances are generated when the size of the disk is reduced and falls into a certain range. With dual-disk ring (DDR) nanostructures, a rich set of tunable Fano line shapes is provided. More specifically, we report our observations on the optical behavior of the DDRs including asymmetric cases either in two disks with different sizes or their asymmetric locations inside the ring. In the case of symmetric dual-disk ring (SDDR) nanostructures, we demonstrate that the quadrupolar and the hexadecapolar Fano resonances are suppressed, which can reduce the cross-talk in spectroscopic measurements, while the octupolar and the triakontadipolar Fano resonances are enhanced. The potential of using the studied plasmonic nanostructures as biochemical sensors is evaluated with the figure of merit (FOM) and the contrast ratio (CR). The values of the FOM and the CR achieved using the triakontadipolar Fano resonance in the SDDR are 17 and 57%, respectively. These results indicate that the SDDRs could be developed into a high-performance biochemical sensor in the visible wavelength range.

(2006). Plantibodies: A Novel Strategy to Create Pathogen-Resistant Plants. Biotechnology and Genetic Engineering Reviews: Vol. 23, No. 1, pp. 253-272.

Fusarium verticillioides is the primary causal agent of Fusarium ear and kernel rot in maize, producing fumonisin mycotoxins that are toxic to humans and domestic animals. Rapid detection and monitoring of fumonisin-producing fungi are pivotally important for the prevention of mycotoxins from entering into food/feed products. Chicken-derived single-chain variable fragments (scFvs) against cell wall-bound proteins from F. verticillioides were isolated from an immunocompetent phage display library. Comparative phage enzyme-linked immunosorbant assays (ELISAs) and sequencing analyses identified four different scFv antibodies with high sensitivity. Soluble antibody ELISAs identified two highly sensitive scFv antibodies, FvCA3 and FvCA4, with the latter being slightly more sensitive. Three-dimensional modeling revealed that the FvCA4 may hold a better overall structure with CDRH3, CDRL1 and CDRL3 centered in the core region of antibody surface compared with that of other scFvs. Immunofluorescence labeling revealed that the binding of FvCA4 antibody was localized to the cell walls of conidiospores and hyphae of F. verticillioides, confirming the specificity of this antibody for a surface target. This scFv antibody was able to detect the fungal mycelium as low as 10(-2) μg/mL and contaminating mycelium at a quantity of 10(-2) mg/g maize. This is the first report that scFv antibodies derived from phage display have a wide application for rapid and accurate detection and monitoring of fumonisin-producing pathogens in agricultural samples.

This paper demonstrates the optical nonlinearity in opto-mechanical ring resonators that consist of a bus waveguide and two ring resonators, which is induced by the optical gradient force and characterized by the Kerr-like coefficient. Each ring resonator has a free-hanging arc that is perpendicularly deformable by an optical gradient force and subsequently this deformation changes the effective refractive index (ERI) of the ring resonator. The change of the ERI induces optical nonlinearity into the system, which is described by an equivalent Kerr coefficient (Kerr-like coefficient). Based on the experimental results, the Kerr-like coefficient of the ring resonator system falls in the range from 7.64 × 10−12 to 2.01 × 10−10 m2W−1, which is at least 6-order higher than the silicon’s Kerr coefficient. The dramatically improved optical nonlinearity in the opto-mechanical ring resonators promises potential applications in low power optical signal processing, modulation and bio-sensing. Published version

An isotope dilution liquid chromatography-tandem mass spectrometry (LC-MS/MS) method with a fast sample preparation using homemade clean-up cartridges was developed for simultaneous determination of co-occurring mycotoxins exemplified with aflatoxin B1 (AFB1) and T-2 toxin (T-2) in representative biomatrices of rat plasma, heart, liver, kidney, spleen, lung and brain in a total run time of 7 min. The established approach using stable internal standards of [C-13(17)]-AFB1 and [C-13(24)]-T-2 was extensively validated by determining the specificity, linearity (R-2 >= 0.9990), sensitivity (lower limit of quantitation at 0.05 ng mL(-1)), accuracy (70.9-107.7%), precision (RSD = 70.8%). Based on this methodological advance, the subsequent kinetics and tissue distribution after oral administration of 0.5 mg kg(-1) b.w. of both AFB1 and T-2 in rats were thoroughly studied. As revealed, both AFB1 and T-2 were rapidly eliminated with the half-life time (t(1/2)) in plasma of 8.44 +/- 4.02 h and 8.12 +/- 4.05 h, respectively. Moreover, AFB1 accumulated in all organs where the highest concentration was observed in liver (1.34 mu g kg(-1)), followed by kidney (0.76 mu g kg(-1)). Notably, only low levels of T-2 were observed in spleen (0.70 mu g kg(-1)) and in liver (0.15 mu g kg(-1)). The achieved data as supporting evidence would substantially promote the practical application of the proposed LC-MS/MS method for in vivo toxicokinetics and toxicity studies of co-occurring mycotoxins imitating natural incidence in rat system.

A novel structure of GNSS carrier loop based on Adaptive Gain Control (AGC) is given, and the loop is applied to track carrier frequency under high dynamic and low signal-to-noise ratio (SNR) conditions. It is found that adjusting the gain of error adjustment (GEA) of carrier loop can influence the loop bandwidth, so as to give consideration to both dynamic and stable characteristics. So a mathematical model which can adaptively adjust the loop gain according to the frequency discrimination results is proposed and tested for the loop tracking ability under GNSS software carrier platform. The test results indicate that the model can lock signals quickly with larger frequency jitter, can improve the frequency stability of tracked output signals, and can effectively reduce the impact of faulty control.

Microtechnology is not unfamiliar to Sin-gapore. Around the 1980s, Singapore es-tablished itself as one of the leading manufacturers of semiconductor micro-chips. Over the last 10 years, Singapore has established a biomedical research industry, epitomized by Biopolis, a two million square feet research campus. Biopolis is home to the national biomedical research institutes under the administration of the Agency of Science, Technology and Research (A*STAR), as well as corporate labs from GlaxoSmithKine (GSK), No-vartis and Eli Lily. A stone’s throw away is another major research hub, Fusionopolis, the physical science and engineering equivalent of Biopolis. Microtechnology also finds its way into this vibrant research community facilitating inter-disciplinary and translational research between biomedical and physical sciences. Other research centers, such as the Research Centres of Excellence initiated by the National Research Foundation, at the National University of Singapore and Nanyang Technological University are also in close proximity. Engineers or physical scientists need not look very far to find a myriad of opportunities to apply their technologies to help expedite biomedical sciences. Here, we feature a number of research centers where mi-crotechnologies are finding headway in advancing biomedical and fundamental sciences.

The importance of accurate measurements of the surface roughness of products can never be over-emphasised, for instance, the design and manufacture of moulds and dies is never complete without their surface roughness being specified and measured. The surface finish of products, normally expressed in terms of roughness, is also frequently an acceptance criterion in the metal-forming industry. There have also been attempts to correlate roughness with the behaviour and service life of products. Current techniques for surface roughness measurements can be classified into two broad categories: those using a measuring stylus which requires direct contact with the test object and those using non-contacting laser techniques. In these techniques, a common drawback is the small area where the roughness can be measured at any one time. In this paper, a whole field method of recording surface roughness using laser speckle for subsequent measurement and analysis is presented. The method enables direct measurement of the local roughness at any point on the test surface as well as the average roughness of the entire surface. It is found that roughness in the range of approximately 0.4 μm to 50 μm can be measured using this method.

This paper analyzes the regional ionosphere total electron content (TEC) long-term variations obtained via using GPS measurements. For this purpose,the authors used the TEC data from TEC maps (global maps in IONEX format) over 11 years.TEC at five IGS tracking stations of China was interpolated by a suitable method. Results show that the peak of TEC for different stations approximately occurs during the same period from years 1999 to 2009.In detail,there is also a close relationship between the variation of ionospheric TEC and the spatial size of the region.

A whole-field method of double-exposure speckle photography is employed to determine metal surface roughness by correlation between two speckle patterns. A movable rectangular aperture that is mounted before an image lens is shifted between the exposures, which results in a decrease in the contrast of the reconstructed Young's fringes with increasing roughness. The technique permits evaluation of the roughness of particular points on a surface as well as the average roughness of an entire surface. Four sets of random surfaces that were prepared by different machine-finishing processes and with roughnesses ranging from 0.6 to 13 µm have been tested. Different methods have been carried out to process the test data, and a practical method for the evaluation of surface roughness is proposed.

Multipath interference is one of the important error sources in most high-performance GNSS receivers. A GNSS multipath estimation algorithm based on a RAKE architecture is proposed to take advantage of multipath signals to improve the GNSS receiver performance, rather than to suppress multipath. The impact of GNSS multipath on the receiver performance is evaluated by analyzing its characteristics. The principles of the proposed Rake-based algorithm in GNSS receivers are described, and then the process of its implement is given. Simulated scenarios of multipath are applied, the algorithm is used to resolve the multipath signal and get the time of arrival (TOA) of the line-of-sight (LOS). The improvement of positioning accuracy of GNSS receivers is confirmed by simulation results.

A metallic nanoparticle can act as an optical antenna, enhancing the fluorescence of nearby fluorescent molecules. We investigate the effects of a silica spacer layer on this fluorescence enhancement. Numerical simulations using the Finite- Difference Time Domain (FDTD) method is performed to find the optimum size for the gold nanosphere core as well as the optimum thickness of the silica shell. We present the dependence of radiative decay rate and quantum yield of the fluorescent molecule with respect to varying silica layer thicknesses.