This paper presents a numerical investigation on the local and distortional buckling behaviour of cold-formed steel zed-section beams subjected to uniformly distributed transverse loads. The analysis ...is performed using a semi-analytical finite strip method. The beams investigated include both detached sections and restrained sections. The results obtained from the present study highlight the differences in the local and distortional buckling behaviours of the thin-walled sections between pure bending and the uniformly distributed loading.
Lipoprotein (a) Lp(a) is an independent risk factor for atherosclerosis-related events that is under strong genetic control (heritability = 0.68-0.98). However, causal mutations and functional ...validation of biological pathways modulating Lp(a) metabolism are lacking. We performed a genome-wide association scan to identify genetic variants associated with Lp(a)-cholesterol levels in the Old Order Amish. We confirmed a previously known locus on chromosome 6q25-26 and found Lp(a) levels also to be significantly associated with a SNP near the APOA5-APOA4-APOC3-APOA1 gene cluster on chromosome 11q23 linked in the Amish to the APOC3 R19X null mutation. On 6q locus, we detected associations of Lp(a)-cholesterol with 118 common variants (P = 5 × 10(-8) to 3.91 × 10(-19)) spanning a ∼5.3 Mb region that included the LPA gene. To further elucidate variation within LPA, we sequenced LPA and identified two variants most strongly associated with Lp(a)-cholesterol, rs3798220 (P = 1.07 × 10(-14)) and rs10455872 (P = 1.85 × 10(-12)). We also measured copy numbers of kringle IV-2 (KIV-2) in LPA using qPCR. KIV-2 numbers were significantly associated with Lp(a)-cholesterol (P = 2.28 × 10(-9)). Conditional analyses revealed that rs3798220 and rs10455872 were associated with Lp(a)-cholesterol levels independent of each other and KIV-2 copy number. Furthermore, we determined for the first time that levels of LPA mRNA were higher in the carriers than non-carriers of rs10455872 (P = 0.0001) and were not different between carriers and non-carriers of rs3798220. Protein levels of apo(a) were higher in the carriers than non-carriers of both rs10455872 and rs3798220. In summary, we identified multiple independent genetic determinants for Lp(a)-cholesterol. These findings provide new insights into Lp(a) regulation.
In situ Raman spectroscopic studies, in combination with electrochemical measurements, further testify that the electrochemical reactions, i.e., iodate reduction and periodic hydrogen evolution, ...coupled with alternately predominant diffusion and convection mass transfer of iodate, account for the potential oscillation that appears under galvanostatic reduction of iodate over its limiting current in alkaline solution. The diffusion-limited depletion and the convection-enhanced replenishment of the iodate consist of a pair of positive and negative feedback steps between the bistable states (iodate reduction with and without hydrogen evolution). This mechanism is applicable to the same category of oscillators originating from such a coupling. The limiting diffusion concentration profile and the concentration variation of iodate in the diffusion layer during the oscillation by diffusion-limited depletion and by convection-enhanced replenishment through hydrogen evolution have been measured directly by using in situ Raman spectroscopy for the first time. A crossing cycle in the cyclic voltammogram that displays the bistability and the positive and negative feedbacks can be obtained only when the scan is reversed at a potential where hydrogen evolution takes place, and hydrogen evolution is thus mainly to induce the convection feedback of the reactant after its surface concentration depletes to zero by diffusion-limited reduction, rather than purely an additional current carrier. No oscillation can occur by simply removing the convection feedback with another pure current carrier instead of hydrogen evolution. The other model on the basis of negative differential resistance (NDR) fails to reflect the convection feedback step required for this category of oscillators.
To investigate the effect of arbuscular mycorrhizal fungi (AMF) inoculation and short-term cold exposer on Elymus nutans Griseb, 45day old seedlings of two cultivars, Zhengdao (ZD) and Kangma (KM), ...were subjected to a 5day cold treatment after inoculated with Glomus mosseae. The effects of AMF on the physiology of the two cultivars were determined, and we were especially interested in oxidative indexes under cold stress. Accumulation of reactive oxygen species (ROS), including superoxide and hydrogen peroxide, was very high in cold-stressed plants and caused lipid peroxidation in membranes, which measured as relative electrolyte leakage (REL), malondialdehyde (MDA) content. Less oxidative damage was detected in AMF colonized plants, which was associated with higher activities of superoxide dismutase (SOD), catalase (CAT), ascorbate peroxidase (APX) and glutathione reductase (GR). Mycorrhizal inoculum application promoted plant growth and enhanced the level of chlorophyll and antioxidant compounds such as glutathione and soluble sugars. We also measured the extent of mycorrhizal colonization. These protective mechanisms were found to be more efficient in temperature-tolerant KM than temperature-sensitive ZD. Overall, we suggest that AMF inoculation can improve plant resistance to cold stress in E. nuatans seedlings by directly scavenging ROS and by modulating redox balance and other defense mechanisms.
•Cold cause oxidative damage on Elymus nutans Griseb seedlings.•Protective effect of arbuscular mycorrhizal fungi (AMF) inoculation on cold-induced oxidative damage.•Glomus mosseae inoculation could help Elymus nutans Griseb with their growth under cold stress.
During the 1998 Leonid meteor shower, multi‐instrument observations of persistent meteor trains were made from the Starfire Optical Range on Kirtland Air Force Base, New Mexico, and from a secondary ...site in nearby Placitas, New Mexico. The University of Illinois Na resonance lidar measured the Na density and temperature in the trains, while various cameras captured images and videos of the trains, some of which were observed to persist for more than 30 min. The Na density measurements allow the contribution of Na airglow to the observed train luminescence to be quantified for the first time. To do this, persistent train luminescence is numerically modeled. Cylindrical symmetry is assumed, and observed values of the Na density, temperature, and diffusivity are used. It is found that the expected Na luminosity is consistent with narrowband CCD all‐sky camera observations, but that these emissions can contribute only a small fraction of the total light observed in a 0.5–1 μ bandwidth. Other potential luminosity sources are examined, in particular, light resulting from the possible excitation of monoxides of meteoric metals (particularly FeO) and O2(b1∑g+) during reactions between atmospheric oxygen species and meteoric metals. It is found that the total luminosity of these combined processes falls somewhat short of explaining the observed brightness, and thus additional luminosity sources still are needed. In addition, the brightness distribution, the so‐called hollow cylinder effect, remains unexplained.
Medroxyprogesterone acetate (MPA) has a relative molecular mass of only 344.5 and it has no immunogenicity. The analytical methods for the carbodiimides and the mixed anhydride were both adopted to ...couple MPA with bovine serum albumin, the carrier protein. The coupling rates of conjugate using the above methods were estimated to be 14 and 20 by ultraviolet spectrophotometry. The coupling was successful and verified according to sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) analysis. New Zealand White rabbits were immunized with the conjugate, the coupling rate of which was 14, and blood was collected after 5 periods of immunities. Then the titer of antiserum was tested to be 2.6 x 105 by indirect enzyme-linked immunosorbent assay (ELISA). Based on the purified antibody, a competitive indirect ELISA was developed. ELISAs provided a limit of detection of 0.096 ng/g, recoveries (in the edible tissues) between 72% and 91%, and a working range of 0.1 to 8.1 ng/g. Preliminary evaluation of assay performance through specificity, sensitivity, precision, and accuracy showed that this ELISA method can be applied to the practical detection of MPA in tissue samples. Moreover, it was compared with liquid chromatography tandem mass spectrometry (LC/MS/MS). The ion pair for quantification of MPA was 345.2/123.1, and the linear equation of MPA was Y = 6.68 x 10(3) X + 6.63 x 10(2). The 2 analytical methods can be applied to monitor MPA and other steroid residues in edible foods.
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