Systematic relationships of some members of the genera Oesophagostomum and Chabertia (Nematoda: Chabertiidae) based on ribosomal DNA sequence data

The present study characterised seven species of the Chabertiidae (Nematoda: Strongyloidea) belonging to either the subfamily Oesophagostominae (Oesophagostomum radiatum, Oesophagostomum venulosum, Oesophagostomum dentatum, Oesophagostomum quadrispinulatum, Oesophagostomum columbianum, Oesophagostomum bifurcum) or to the subfamily Chabertiinae (Chabertia ovina) by their second internal transcribed spacer rDNA sequence, assessed the extent of intraspecific variation and interspecific differences in the sequence, and inferred the phylogenetic relationship of C. ovina with respect to members of the Oesophagostominae. In both the phenetic and cladistic analyses of the sequence data, Chabertia was nested within Oesophagostomum, suggesting either that the species examined represent members of the same genus, or alternatively, that Oesophagostomum may represent more than one genus.     

Histomorphometric, physical, and mechanical effects of spaceflight and insulin-like growth factor-I on rat long bones

Pituitary adenylate cyclase activating peptide and vasoactive intestinal peptide belong to the same neuropeptide family. Both peptides are present in nerve fibers in the gastric wall and are thought to be involved in the regulation of inflammatory processes. Experimental ulcers were induced in the rat gastric mucosa by local application of acetic acid. During the healing process we examined the PACAP and VIP innervation by means of immunohistochemistry and in situ hybridization. The ulcer area was examined from day 1 to day 15 after ulcer induction. There was a marked depletion of PACAP in nerve fibers at the ulcer margin from day 1 and onwards. On day 10 and day 15, PACAP-immunoreactive nerve fibers could again be visualized at the ulcer margin. In contrast, VIP immunoreactive nerve fibers were present at the ulcer margin at all time points studied. From day 10 following ulcer induction PACAP- and VIP- immunoreactive nerve fibers were increased in frequency in the smooth muscle beneath the ulcer. An upregulation of VIP and PACAP mRNA was also demonstrated in the myenteric ganglia adjacent to ulcer. The present results indicate that neuronal PACAP and VIP react differently to the inflammation at the ulcer margin but similarly in the smooth muscle during the ulcer healing.     

The success of locoregional, low-dose recombinant interleukin-2 therapy in tumor-bearing mice is dependent on the time of rIL-2 administration

The most common chromosomal aberrations in myelodysplastic syndromes (MDS) are complete or partial loss of chromosomes 5 and 7, and trisomy 8. To identify genes important in the pathogenesis of this disease that could be associated with these gross chromosomal defects, we have employed the differential display PCR (DDPCR) procedure developed by Liang and Pardee. This method allows simultaneous comparison of several cDNA sources for the presence of differentially expressed genes. Polymorphonuclear cells (PMNs) from two MDS patients, containing a 5q deletion or a trisomy 8, and three healthy controls were used. Initial screening resulted in the identification of five and three partial cDNA sequences, respectively that were either differentially expressed in both patient samples or in individual patients, as compared with the controls. The authenticity of aberrant expression was verified by reanalyzing the same primer combinations on newly prepared cDNA. Differential expression of the three remaining fragments was subsequently checked on a larger panel of MDS patients, using amplicon-specific primer sets. These were obtained by cloning and sequencing of the fragments. For one partial cDNA (DC3), the original expression pattern, i.e., decreased expression in individual MDS patients, was confirmed. These results demonstrate the utility of the DDPCR procedure to isolate differentially expressed sequences in primary patient samples where the availability of cells is a limiting factor.     

An evaluation of the effectiveness of adaptive histogram equalization for contrast enhancement

Adaptive histogram equalization (AHE) and intensity windowing have been compared using psychophysical observer studies. Experienced radiologists were shown clinical CT (computerized tomographic) images of the chest. Into some of the images, appropriate artificial lesions were introduced; the physicians were then shown the images processed with both AHE and intensity windowing. They were asked to assess the probability that a given image contained the artificial lesion, and their accuracy was measured. The results of these experiments show that for this particular diagnostic task, there was no significant difference in the ability of the two methods to depict luminance contrast; thus, further evaluation of AHE using controlled clinical trials is indicated.     

Thermal alteration of a cyclic fatty acid produced by a flaxseed extract

Methyl 8-[2-(cis-pent-2′-enyl)-3-oxo-cis-cyclopent-4-enyl] octanoate (I) is the methyl ester of a cyclic fatty acid synthesized enzymically from an incubation of linolenic acid with an extract of flaxseed (Linum usitatissimum L.). A proposed trivial name for I is methyl 12-oxo-cis-10, 15-phytodienoate (12-oxo-PDA). The evidence presented indicated that compound I has thecis configuration of the carbon chains with respect to the cyclopentenone ring. Treatment with acid, base, or heat isomerized I to a second product (II) that has thetrans configuration of the carbon chains. Prolonged heat treatment of II yielded a third cyclic product, methyl 12-oxo-9(13),cis-15-phytodienoate (III).     

Complex refractive index,single scattering albedo,and mass absorption coefficient of secondary organic aerosols generated from oxidation of biogenic and anthropogenic precursors

Refractive index and optical properties of biogenic and anthropogenic secondary organic aerosol (SOA) particles were investigated. Aerosol precursors, namely longifolene, α-pinene, 1-methylnaphthalene, phenol, and toluene were oxidized in a Teflon chamber to produce SOA particles under different initial hydrocarbon concentrations and hydroxyl radical sources, reflecting exposures to different levels of nitrogen oxides (NO_x). The real and imaginary components (n and k, respectively) of the refractive index at 375?nm and 632?nm were determined by Mie theory calculations through an iterative process, using the χ² function to evaluate the fitness of the predicted optical parameters with the measured scattering, absorption, and extinction coefficients from a Photoacoustic Extinctiometer and Cavity Attenuated Phase Shift Spectrometer. Single scattering albedo (SSA) and bulk mass absorption coefficient (MAC) at 375?nm were calculated. SSA values of SOA particles from biogenic precursors (longifolene and α-pinene) were ～0.98–0.99 (～6.3% uncertainty), reflecting purely scattering aerosols regardless of the NO_x regime. However, SOA particles from aromatic precursors were more absorbing and displayed NO_x-dependent SSA values. For 1-methylnaphthalene SOA particles, SSA values of 0.92–0.95 and ～0.75–0.90 (～6.1% uncertainty) were observed under intermediate- and high-NO_x conditions, respectively, reflecting the absorbing effects of SOA particles and NO_x chemistry for this aromatic system. In mixtures of longifolene and phenol or longifolene and toluene SOA under intermediate- and high-NO_x conditions, k values of the aromatic-related component of the SOA mixture were higher than that of 1-methylnaphthalene SOA particles. With the increase in OH exposure, k_phenol decreased from 0.10 to 0.02 and 0.22 to 0.05 for intermediate- and high-NO_x conditions, respectively. A simple relative radiative forcing calculation for urban environments at λ?=?375?nm suggests the influence of absorbing SOA particles on relative radiative forcing at this wavelength is most significant for aerosol sizes greater than 0.4?µm.

Copyright © 2019 American Association for Aerosol Research     

CO2 process intensification of algae oil extraction to biodiesel

Algae-to-biodiesel processes are hindered by high costs and low energy return on investment.^1,2. Herein, three foci in research improve algae-to-biodiesel processes by: (1) reducing high installation and energy costs in the CO₂ sequestration, cultivation, and harvesting stages; (2) improving oil extraction and biodiesel generation; and (3) increasing utilization of the proteins in lipid-extracted biomass (e.g., for animal feed), as well as the omega-3 fatty acids for nutraceuticals and food supplements. A process is introduced that uses carbon dioxide to aid in all three of these foci. CO₂ is used first in the form of microbubbles to lyse algae cell walls, releasing triglyceride oils. CO₂ also aids with transesterification of these triglycerides using methanol. At low temperatures (353.15–368.15 K) and intermediate pressures (5–10 MMPa), carbon dioxide causes methanol to dissolve partially in the triglyceride phase and triglyceride to dissolve partially in the methanol phase, increasing the transesterification reaction rate. Due to the nondestructive nature of these processes, other metabolites can also be harvested providing improvements in both mass and economic efficiency with an overall sharp reduction in the modeled price of biodiesel.     

Al改性HP40合金力学性能的研究

在HP40合金中加入5%～20％的Al替代Ni，进行室温压缩和硬度力学性能试验。结果表明，铝的加入使合金的强度和硬度得到了显著提高。但随着Al含量的提高，由于树枝状（Ni，Fe）Al金属间化合物的析出及增加,使合金的脆性增加。