Highlights • High-dose influenza vaccine induced higher antibody responses in individuals aged ⩾65 years. • High-dose influenza vaccine induced higher plasmablast responses. • Cell-mediated immunity ...and memory responses were similar between high and standard-dose vaccine.
The high strength 7xxx series aluminium alloys are usually difficult to be prepared as semi-solid feedstock, because some dispersoid particles （soluble only in liquid） could pin at grain and subgrain ...boundary to make the alloy difficultly recrystallise. In this work, a novel multistep reheating regime is developed for recrystallisation and partial melting （RAP） route to prepare fine spheroidal microstructure of semi-solid AI-Zn- Mg-Cu alloy. After reheating to 665 ℃, holding for 4 min and subsequent isothermally holding at 620 ℃ with total heating time of 15 min, fine spheroidal microstructures with grain size of-40 μm were prepared without remained unrecrystallised grains and directionality, which are much finer than the conventionally obtained microstructures （-100 μm）.
The 7075 aluminium matrix composite reinforced with nano-sized Si C particles was fabricated by ultrasonic assisted semisolid stirring method. The compression mechanical behaviour of the fabricated ...composite in semisolid state was investigated. The results show that the microstructure of the composite before semisolid compression consists of fine and spheroidal solid grains surrounded by liquid phase.Semisolid compression led to a nonuniform plastic deformation of solid grains. A slight plastic deformation occurred in the locations near the free surface due to the dependence of deformation on liquid flow and flow of liquid incorporating solid grains. However, obvious plastic deformation occurred in the central location and location contacting to die due to the contribution of plastic deformation of solid grains.The true stress–strain curve of the sample compressed at 500 °C consists of rapid increase of true stress and steady stage. However, rapid increase of true stress and decrease of true stress and steady stage are involved in the true stress–strain curves of the samples compressed at 550, 560, 570, 580 and 590 °C.The true stress–strain curve at 600 °C is similar to that at 500 °C. Apparent viscosity decreases with an increase of shear rate, indicating a shear thinning occurrence. When soaking time increases from 5 min to 15 min, the peak stress and steady stress decrease significantly. A further increase of the soaking time led to a slight change. Peak stress and steady stress increase with increasing volume fraction of Si C particles. A sudden increase or decrease of compression velocity led to a significant increase or decrease of the steady stress. The destruction of the samples compressed at solid state temperature mainly depends on cracks parallel to compression direction. However, the destruction forms of the samples compressed at semisolid temperatures consist of cracks parallel to compression direction and partial collapse. Increasing soaking time led to an obvious change of the destruction forms. Compression velocity affects slightly the macro appearance of the sample compressed at semisolid temperatures.
Background.
Influenza disproportionately impacts older adults while current vaccines have reduced effectiveness in the older population.
Methods.
We conducted a comprehensive evaluation of cellular ...and humoral immune responses of adults aged 50 years and older to the 2008–2009 seasonal trivalent inactivated influenza vaccine and assessed factors influencing vaccine response.
Results.
Vaccination increased hemagglutination inhibition and neutralizing antibody; however, 66.3% of subjects did not reach hemagglutination inhibition titers ≥ 40 for H1N1, compared with 22.5% for H3N2. Increasing age had a minor negative impact on antibody responses, whereas prevaccination titers were the best predictors of postvaccination antibody levels. Preexisting memory B cells declined with age, especially for H3N2. However, older adults still demonstrated a significant increase in antigen-specific IgG+ and IgA+ memory B cells postvaccination. Despite reduced frequency of preexisting memory B cells associated with advanced age, fold-rise in memory B cell frequency in subjects 60+ was comparable to subjects age 50–59.
Conclusions.
Older adults mounted statistically significant humoral and cell-mediated immune responses, but many failed to reach hemagglutination inhibition titers ≥40, especially for H1N1. Although age had a modest negative effect on vaccine responses, prevaccination titers were the best predictor of postvaccination antibody levels, irrespective of age.
The introduction of pneumococcal conjugate vaccine (PCV) to the U.S. recommended childhood immunization schedule in the year 2000 added three injections to the number of vaccinations a child is ...expected to receive during the first year of life. Surveys have suggested that the addition of PCV has led some immunization providers to move other routine childhood vaccinations to later ages, which could increase the possibility of missing these vaccines. The purpose of this study was to evaluate whether introduction of PCV affected immunization coverage for recommended childhood vaccinations among 13-month olds in four large provider groups.
In this retrospective cohort study, we analyzed computerized data on vaccinations for 33,319 children in four large provider groups before and after the introduction of PCV. The primary outcome was whether the child was up to date for all non-PCV recommended vaccinations at 13 months of age. Logistic regression was used to evaluate the association between PCV introduction and the primary outcome. The secondary outcome was the number of days spent underimmunized by 13 months. The association between PCV introduction and the secondary outcome was evaluated using a two-part modelling approach using logistic and negative binomial regression.
Overall, 93% of children were up-to-date at 13 months, and 70% received all non-PCV vaccinations without any delay. Among the entire study population, immunization coverage was maintained or slightly increased from the pre-PCV to post-PCV periods. After multivariate adjustment, children born after PCV entered routine use were less likely to be up-to-date at 13 months in one provider group (Group C: OR = 0.5; 95% CI: 0.3-0.8) and were less likely to have received all vaccine doses without any delay in two Groups (Group B: OR = 0.4, 95% CI: 0.3 - 0.6; Group C: OR = 0.5, 95% CI: 0.4-0.7). This represented 3% fewer children in Group C who were up-to-date and 14% (Group C) to 16% (Group B) fewer children who spent no time underimmunized at 13 months after PCV entered routine use compared to the pre-PCV baseline. Some disruptions in immunization delivery were also observed concurrent with temporary recommendations to suspend the birth dose of hepatitis B vaccine, preceding the introduction of PCV.
These findings suggest that the introduction of PCV did not harm overall immunization coverage rates in populations with good access to primary care. However, we did observe some disruptions in the timely delivery of other vaccines coincident with the introduction of PCV and the suspension of the birth dose of hepatitis B vaccine. This study highlights the need for continued vigilance in coming years as the U.S. introduces new childhood vaccines and policies that may change the timing of existing vaccines.
The objective of this study was to identify and investigate the factors that affect the use of conservation practices in West Tennessee that is a region of major row crop production and major soil ...erosion. The household production theory was introduced to describe the use of soil conservation practices by farmers. The conceptual model of decision process of soil conservation was constructed and investigated by regression analysis. The results of the study indicated that farmers' economic feasibility and other circumstances permit them to use different types of conservation measures. The various federal conservation programs are important in providing economic incentives and options in soil erosion control. The major conclusion was that economic incentives and feasibility were important factors for farmers to adopt conservation practice. Personal factors and sociological factors determined attitudes, beliefs towards soil conservation. Information sources, educational programs and other technical supports were also important in increasing knowledge and changing farmers' attitudes toward conservation and the use of conservation practices.
In 1976, Tenn enacted the "Agriculture, Forest, & Open Space Act," which allowed property owners to request reclassification under one of three provisions of agricultural, forestland, & open space ...area. The vast majority (99.2%) of the 164,572 Greenbelt parcels in 1990 were under the agricultural provision. Land classified under the Greenbelt Act must be appraised based on "use value" for tax purposes rather than on "market value." Tenn county property assessors must maintain both appraisal values. Counties were placed into metropolitan, urban, large rural, & small rural (N = 5, 24, 29, & 37, respectively) categories. Greenbelt parcels in metropolitan & urban counties exprienced much greater reduction in appraisal values between market value & use value appraisals &, hence, also greater savings in property tax per Greenbelt parcel than in rural counties. Rural & urban counties lost a greater proportion of the countywide property tax base due to Greenbelt parcels than did metropolitan counties, because only a small proportion of the property tax base is in agricultural land in metropolitan counties. An indirect analysis of data for the 66 rural Tenn counties indicates that most of the loss of the property tax base due to Greenbelt reclassification was replaced by the approval of higher countywide property tax rates, which, in Tenn, are set by the local legislative body.
In this work, squeeze casting experiments of flywheel housing components with a large wall thickness difference and a complex shape were carried out with AlSi9Mg aluminum alloy. The defects, ...microstructures, and mechanical properties under different process parameters were investigated. Furthermore, the local pressurization process was applied to the thick-walled positions to force-feed the cast defects. The mechanical properties and microstructures at these positions were analyzed. The results showed that the surface quality of formed components was good and that local pressurization could effectively reduce the shrinkage cavity and shrinkage porosity in thick walls, but the scope and effect of forced feeding were limited. The optimum process parameters were a pouring temperature of 650 °C, a specific pressure of 48 MPa, a mold temperature of 220 °C, a local pressurization of 800 MPa, and pressure delay times of 15 s (side A) and 17 s (side B). The ultimate tensile strength, yield strength, and elongation of the formed component under validation experiments of the optimum process parameters were 201 MPa, 103 MPa, and 5.1%. Meanwhile, the fine grains of primary α-Al were mainly rosette and equiaxed grains, and the average grain size was about 40 μm. The microstructure of the eutectic silicon was acicular and was prone to segregation under pressure. According to profile morphology, the positions after pressurization were divided into a deformation zone, a direct action zone, and an indirect action zone. The coexistence of as-cast and plastic deformation microstructures was observed. The effect of local pressurization mainly involved a change in the solidification process, plastic deformation, and forced feeding.
The short-term isothermal oxidation process of hot extruded GH3536 alloy in solid and semi-solid temperature ranges was investigated. The solid oxidation rates at 1200 °C, 1250 °C, 1300 °C were 0.049 ...mg2cm−4s−1，0.125 mg2cm−4s−1, 0.133 mg2cm−4s−1 respectively, while semi-solid oxidation rates at 1350 °C, 1360 °C, 1367 °C were 0.168 mg2cm−4s−1，0.259 mg2cm−4s−1，0.549 mg2cm−4s−1 respectively. Oxide scales formation and spallation were analyzed by X-ray diffraction (XRD), scanning electron microscopy (SEM) with energy dispersion spectroscopy (EDS). The outer diffusion of Cr3+and Fe3+resulted in formation of Fe2O3 and Cr2O3 granular oxides. Diffusion of Ni2+ promoted spinel formation. NiO intermediate oxidation layer was formed beyond 1300 °C, which was conducive to continuous Cr2O3 inner oxidation layer formation. The growth and spallation of oxide scales were significantly accelerated during semi-solid oxidation. The liquid film in the semi-solid microstructure provided a diffusion channel. The inner oxidation layer was destroyed due to thermal stress and severe deformation of the interface between oxide scales and base alloy, which led to a sharp increase in oxidation rate.
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