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We present possible conceptual designs of a laser system for driving table-top free-electron lasers based on terahertz acceleration. After discussing the achievable performances of laser amplifiers with Yb:YAG at cryogenic and room temperature and Yb:YLF at cryogenic temperature, we present amplification modules with available results and concepts of amplifier chains based on these laser media. Their performances are discussed in light of the specifications for the tasks within the table-top light source. Technical and engineering challenges, such as cooling, control, synchronization and diagnostics, are outlined. Three concepts for the laser layout feeding the accelerator are eventually derived and presented.
In laboratories, the parasitism rate of Ostrinia furnacalis (Güenée) (Lepidoptera: Crambidae) eggs by Trichogramma dendrolimi Matsumura (Hymenoptera: Trichogrammatidae) is low; however, efforts to control O. furnacalis with T. dendrolimi in the field have been successful. In this study, the effects of the number of attacks by T. dendrolimi against O. furnacalis eggs and diet of O. furnacalis larva on wasp development were investigated. The results indicated that more attacks increased significantly not only the successful parasitism rate of O. furnacalis eggs by T. dendrolimi, but also the percentage of host eggs that failed to develop into either O. furnacalis larvae or T. dendrolimi. Both the size and female proportion of T. dendrolimi offspring decreased as the number of attacks increased. The number of T. dendrolimi eggs laid in per host egg increased significantly as the ratio of wasps to host eggs increased from 1:5 to 3:5. Host diet also significantly affected the developmental time of immaturity and the emergence rate of adults of T. dendrolimi. These results illustrate how inundative releases of T. dendrolimi can successfully control O. furnacalis despite the fact that pest parasitism by the subsequent wasp generation decreases sharply in the field. The suitability of O. furnacalis eggs to T. dendrolimi and the superparasitism effects on offspring of T. dendrolimi are discussed.
A new approach is proposed to analyze Bremsstrahlung X-rays that are emitted from laser-produced plasmas (LPP) and are measured by a stack type spectrometer. This new method is based on a spectral tomographic reconstruction concept with the variational principle for optimization, without referring to the electron energy distribution of a plasma. This approach is applied to the analysis of some experimental data obtained at a few major laser facilities to demonstrate the applicability of the method. Slope temperatures of X-rays from LPP are determined with a two-temperature model, showing different spectral characteristics of X-rays depending on laser properties used in the experiments.
As one of the follow-up studies of Herschel Planetary Nebula Survey (HerPlaNS; Ueta et al. 2014), we focus on a bipolar planetary nebula (PN) NGC6781 to characterize the dusty nebula and the central star based on our own Herschel data and the rich archival spectroscopic/photometric image data in the wavelengths from UV to far-IR. With CLOUDY, we constructed a comprehensive photoionization model of NGC6781 ever made including data from UV to radio. We succeeded to reproduce the observed spectral energy distribution (SED) and the atomic gas, H2, CO, and OH molecular line fluxes. We found that about 40% of the total dust mass would be from warm-cold dust components.
On 1996 May 10, the All-Sky Monitor aboard RXTE revealed that Cyg X-1 started a transition from its hard state to soft state (Cui 1996). Throughout this interesting episode, snapshots were taken with more sensitive detectors on ASCA, RXTE, and CGRO to monitor the temporal and spectral variability of the source over a broad energy range.
West Nile virus (WNV) infection is an emerging zoonosis that threatens global public health. In this study, a total of 95 bird serum samples from 14 species and 341 horse serum samples were collected from 2008 to 2010 in Shanghai, China. All serum samples were screened initially for WNV-reactive antibodies using a competitive ELISA. The positive samples detected by ELISA were further confirmed using a plaque-reduction neutralization test (PRNT) for WNV and its most closely related flaviviruses in the area to avoid false positives due to cross-reactivity. Five (5·3%) of the bird serum samples and none (0·0%) of the horse serum samples tested positive for WNV antibodies. The findings strongly suggest that some of the birds, specifically the resident birds in China, had been exposed to WNV.
Introduction: This study was conducted to compare gender differences in the psychometric properties of the Fagerström Test for Nicotine Dependence (FTND). Methods: The sample comprised 334 Korean immigrants (97 women and 237 men) who reported daily smoking for the past 6 months. Item-by-item responses and exploratory factor analyses (EFA) were compared by gender. Promax rotation was selected based on findings from previous studies suggesting correlated factors. Results: Compared with men, women smoked fewer cigarettes per day, were more likely to smoke when ill in bed, and were less likely to smoke frequently in the morning. The entire sample and men within the sample had the same factor loading pattern, where three items (time to first cigarette, the cigarette most hate to give up, and smoke more frequently in the morning) were loaded on Factor 1 (morning smoking) and the remaining three items (difficult to refrain from smoking in public places, number of cigarettes smoked per day, and smoking even when ill in bed) on Factor 2 (daytime smoking). For women, however, neither the 1- nor 2-factor model fit the data well. Conclusions: For Korean American male smokers, the psychometric properties of the FTND were similar to those seen in other populations, but this was not the case with Korean American women. Clinicians may need to modify their interpretation of nicotine dependence severity if basing only on the FTND with Korean women. The FTND assesses smoking patterns which has a cultural influence and other measures of nicotine dependence should be considered.
The photoelectric properties of oxygen-deficient titanium dioxide (TiO2) nanotube arrays are investigated in this study. The TiO2 nanotube arrays are prepared by anodization, followed by annealing at 450 to 750 °C for 3 h in air to form different crystalline phase mixtures. When the annealing temperature is increased, several phenomena are observed: (1) the ratio of anatase to rutile decreases, (2) the anatase nanotubes are shortened and (3) the thickness of the dense rutile film layer underneath the anatase nanotubes increases. The efficiency of visible light absorption of the nanotube arrays is enhanced with increasing annealing temperature. This is believed to be caused by the ionic defects, especially the oxygen vacancies, generated during the annealing procedure, enabling the absorption of low-energy radiations. The X-ray photoelectron spectroscopy (XPS) depth profile analysis provides the supporting evidence on the chemical nonstoichiometry (i.e., oxygen-deficiency) of the TiO2 nanotube arrays annealed at high temperature. With increasing annealing temperature, a decrease and an increase in the photocurrent density of the nanotube arrays under UV and visible light (wavelength > 500 nm) irradiations, respectively, are detected. The decrease of the photocurrent density under UV irradiation is caused by the reduction in the specific surface area (i.e., anatase nanotubes transform into rutile film with vigorous annealing). In contrast, the increase of the photocurrent density under visible light irradiation is contributed to the oxygen vacancies in the nanostructure, providing extra electron energy levels (locating below the conduction band of TiO2) within the band structure.
Three-dimensionally ordered macro-/mesoporous (3DOM/m) TiO2 monoliths were fabricated by a dual-templating synthesis approach employing a combination of both colloidal crystal templating (hard-templating) and surfactant templating (soft-templating) techniques. Titania precursor, consisting of amphiphilic triblock copolymer Pluronic P123 as a mesopore-structure-directing agent and titanium tetraisopropoxide as a titanium source, was infiltrated into the void spaces of the poly(methyl methacrylate) (PMMA) colloidal crystal monolith. Subsequent thermal treatment produced 3DOM/m TiO2 monolith. The macropore walls of the prepared 3DOM/m TiO2 exhibit a well-defined mesoporous structure with narrow pore size distribution, and the mesopore walls are composed of nanocrystalline anatase TiO2. The material also shows a high surface area (171 m2/g), and large pore volume (0.402 cm3/g).
High saturation magnetization soft magnetic materials are required for future high-density recording heads as well as high frequency inductors. In this work, (Fe0.7Co0.3)1−xNx (or in short FeCoN) alloy films were synthesized with a high saturation magnetization of 24.5 kG, a hard axis coercivity of 5 Oe, an easy axis coercivity of 18 Oe, and a resistivity of 55 μΩcm. The FeCoN film sandwiched between two permalloy layers (5 nm) shows very good magnetic softness, a low hard axis coercivity of 0.6 Oe, an easy axis coercivity of 7.8 Oe, an excellent in-plane uniaxial anisotropy with an anisotropy of about 20 Oe, an initial permeability of 1000, and a roll-off frequency of 1.5 GHz. In order to understand the effect of the permalloy layers on the FeCoN layer, we fabricated four film structures: single layer FeCoN film; FeCoN film sandwiched between two permalloy layers on both sides; FeCoN film with one permalloy layer as the underlayer; and FeCoN film with one permalloy layer as caplayer. All these film structures were both magnetically and structurally characterized and compared. Structural characterization shows that there is no significant difference in the grain size of the FeCoN single layer and the FeCoN layer sandwiched between two permalloy layers. The four film structures have almost the same amount of compressive stress, about −300 MPa; and their saturation magnetostriction constants are also very close, in the range of 39.6×10−6 to 44.3×10−6. Difference in the crystallographic textures was observed in the pole figures for the FeCoN single layer and FeCoN film with permalloy underlayer.
A magnetic-based non-destructive evaluation (NDE) method, which employs Barkhausen effect and measurement of the hysteresis loops, is used to correlate the magnetic and mechanical properties of ultra low carbon (ULC) steel. In particular, the NDE method was used to detect small deviations from linearity that occur in the stress-strain curve well below the 0.2% offset strain, and which generally defines the yield point in materials. Results show that three parameters: jumpsum and jumpsum rate (derived from the Barkhausen spectrum), and the relative permeability (derived from the B-H loops) varies sensitively with small permanent strains, and can be related to the plastic deformation in ULC steels. Investigation of micromagnetic structure revealed that plastic deformation leaves a residual stress state in the samples; the associated magneto-elastic energy makes the favorable easy axis of magnetization in a given grain to be the one that lies closest to the tensile axis. The consequence of this realignment of domains is that wall motion becomes intergranular in nature (as opposed to intragranular in unstrained samples). As a result, the more complex grain boundaries instead of dislocations, become the dominant pinning sites for domain walls. These observations provide a microscopic interpretation of the observed changes in the measured magnetic properties.
The meta-foil is an all-metal self-supported electromagnetic metamaterial that features a space-grid that is locally stiff, yet globally flexible. Owing to its mechanical, thermal, chemical and radiative robustness, it lends itself to widespread applications.
As a newly described member of the apolipoprotein gene family, apolipoprotein A5 (APOA5) has been suggested to play a key role in the triglyceride metabolism in both human and mice. The aim of this study was to identify the porcine (Sus scrofa) APOA5 gene, determine its mRNA and its mutations that are associated with lipid accumulation. The porcine APOA5 cDNA was amplified by reverse transcriptase polymerase chain reaction using the information of the mouse or other mammals. It had been determined that the open reading frame of the porcine APOA5 gene consists of 1092 bp, which encodes a predicted protein composed of 363 amino acids with a similarity to bovine (80.43%) and to human (78.47%). The expression analysis indicated that the porcine APOA5 gene was expressed in hypophysis, fat and liver. Twelve single nucleotide polymorphisms (SNPs), including 4 SNPs in the 5′ end, 1 SNP in second intron, 1 SNP in third exon and 6 SNPs in the 3′ end, were identified in the porcine APOA5 gene and genotyped on the Jinhua × Pietrain F2 reference population, it had revealed that the SNP of C1834T was significantly associated with average backfat thickness and leaf fat weight (P < 0.01 and P < 0.05, respectively). In conclusion, this study has got basic information of the porcine APOA5 gene and provides evidence that the APOA5 gene could be a potential candidate gene for fat deposition.
Somatostatin (SS) is a hormone that inhibits the secretion of growth hormone. Immunization against SS can promote the growth of animals. A novel SS-VP22 fused vaccine, pEGS2SS-V, was constructed from pEGS2SS plasmid with a VP22 gene fragment. Two times of immunization with pEGS2SS-V-induced anti-SS antibodies in mice. Compared with mice immunized with pEGS2SS and 0.85% saline, the growth performance of mice immunized with pEGS2SS-V was increased by 14.1% (P < 0.05) and 48.4% (P < 0.01) on the 2nd week after the first vaccination, respectively. The results indicated that the effects of the somatostatin DNA vaccine could be improved effectively by VP22 gene adjuvant.
To research the protective effect of melatonin against gentamicin ototoxicity.
Guinea pigs were randomly divided into four groups. The first group received intramuscular gentamicin (120 mg/kg body weight/day) for 17 days. Over the same time period, a second group simultaneously received intramuscular gentamicin (120 mg/kg body weight/day) plus (on the other side) intramuscular melatonin (0.3 ml kg body weight/day). Two groups of controls were treated for 17 days with either intramuscular melatonin or intramuscular saline. After the 17 days, each animal underwent distortion product otoacoustic emission testing (both ears). The guinea pigs were sacrificed by decapitation just after the final injection. Their cochleae were used to produce a tissue section, surface preparation and scanning electron microscope preparation.
Distortion product otoacoustic emission testing indicated gentamicin-induced hearing loss at 3, 4, 6 and 8 kHz in gentamicin-treated animals. Animals receiving melatonin co-therapy had significantly attenuated hearing loss and their cochleae showed lower rates of outer hair cell loss (comparing the same cochlear turns), compared with gentamicin-treated animals (p < 0.01).
These findings confirm the occurrence of outer hair cell loss after gentamicin treatment, and the attenuation of such loss following simultaneous melatonin injection, using the method of morphological evaluation. These results suggest that melatonin protects against gentamicin ototoxicity by interfering with cytotoxic mechanisms.
Let f and g be two permutable transcendental entire functions. Assume that f is a solution of a linear differential equation with polynomial coefficients. We prove that, under some restrictions on the coefficients and the growth of f and g, there exist two non-constant rational functions R1 and R2 such that R1 (f) = R(g). As a corollary, we show that f and g have the same Julia set: J(f) = J(g). As an application, we study a function f which is a combination of exponential functions with polynomial coefficients. This research addresses an open question due to Baker.
Hepatitis E virus (HEV) is a zoonotic pathogen of which several species of animals are considered to be reservoirs. Thirty-eight faecal samples, obtained from 22 species of animals including birds in a wildlife first-aid centre in Eastern China, were tested for HEV RNA. Our survey revealed that in total 28·9% (95% confidence interval 14·5–43·4) of the faecal samples from various mammals and birds were HEV RNA positive. Sequence and phylogenetic analyses of the 11 isolates demonstrated that all sequences clustered in genotype 4 with 96–100% identity to each other. In addition, serum samples from seven animal handlers have shown that five (71·4%) were seropositive. The findings imply that cross-species infection of HEV had probably occurred in this zoo-like location, and moreover, birds can be infected naturally with mammalian HEV.
Staphylococcal cassette chromosome mec (SCCmec) type IV methicillin-resistant Staphylococcus aureus (MRSA) strains were identified in 8 (19.5%) of 41 consecutive patients with MRSA ventilator-associated pneumonia (VAP) in this retrospective, observational study. There were no significant differences in VAP severity and crude mortality rates between patients with SCCmec type II strains and patients with SCCmec type IV strains.
In this paper, we used the method to determine the central black mass (M), and the boosting factor (δ), the propagation angle (Φ), and the distance along the axis to the site of the γ-ray production (d) as well for 32 γ-ray loud blazars with available variability timescales. If we take the intrinsic γ-ray luminosity to be λ times the Eddington luminosity, i.e. , then we have following results: the masses of the black hole are in the range of (0.9 ~ 101)×107M⊙(λ = 1.0) or (1.30 ~ 153)×107M⊙(λ=0.1).
In this work, using the database of the university of Michigan Radio Astronomy Observatory (UMRAO), we determined the brightness temperatures, TB for a sample of 167 radio sources. The value of TB is in a range of log TB(K) = 10.46 to 20.08, which suggested that the boosting factors are in a range of δ = 0.41 to 41.26.