Upper extremity hemodynamics and sensation with backpack loads

Heavy backpacks are often used in extreme environments, for example by military during combat, therefore completion of tasks quickly and efficiently is of operational relevance. The purpose of this study was to quantify hemodynamic parameters (brachial artery Doppler and microvascular flow by photoplethysmography; tissue oxygenation by near-infrared spectroscopy; arterial oxygen saturation by pulse oximeter) and sensation in upper extremities and hands (Semmes-Weinstein monofilament test and 2-point discrimination test) while wearing a loaded backpack (12 kg) in healthy adults for 10 min. All values were compared to baseline before wearing a backpack. Moderate weight loaded backpack loads significantly decreased upper extremity sensation as well as all macrovascular and microvascular hemodynamic values. Decreased macrovascular and microvascular hemodynamics may produce neurological dysfunction and consequently, probably affect fine motor control of the hands.     

Genetic design of bioactive glass

This paper reviews the discovery that controlled release of biologically active Ca and Si ions from bioactive glasses leads to the up-regulation and activation of seven families of genes in osteoprogenitor cells that give rise to rapid bone regeneration. This finding offers the possibility of creating a new generation of gene activating glasses designed specially for tissue engineering and in situ regeneration of tissues. Recent findings also indicate that controlled release of lower concentrations of ionic dissolution products from bioactive glasses can be used to induce angiogenesis and thereby offer potential for design of gene activating glasses for soft tissue regeneration.     

Adaptive Boolean Logic Using Ferroelectrics Capacitors as Basic Units of Artificial Neurons and Its Implementation in FPGA

In this work we propose the implementation of boolean logic through artificial neurons with Ferroelectric Capacitor (FeCapacitor) as its basic unit on a reconfigurable hardware platform. Two neurons were implemented: the Perceptron and the Spiking Neuron model. Both neurons use the phenomenon of the hysteresis loop as an activation function and were embedded on a Field Gate Programmable Gate Array (FPGA) hardware platform. The implementations were carried out by Simulink models and hardware synthesizable blocks from DSP Builder software and the results are shown in the form of the models and the boolean functions implemented by them.     

A novel method of making PVF porous foam without using the pore forming agent

Different with the conventional method of manufacturing poly(vinyl formal) (PVF) porous foam by using the pore‐forming agents such as wheat or potato starches, a novel method without using the pore‐forming agent is introduced in this article. Through the help of images taken by a scanning electron microscope, the formation process of the present PVF foam will be discussed in terms of the spinodal decomposition (SD) phase separation principle. Additionally, the effect of poly(vinyl alcohol) concentration and reaction temperature on the pore structure of the PVF foam will be investigated. Moreover, the water adsorption capacities of the PVF foams obtained by the present method will be studied in details through the analyses of pore‐size distribution, mechanical modulus, and thermal property. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41270.     

美国Highland铀矿碱法地浸采铀工艺(续完)

Highiand铀矿是西方国家最大的铀地浸矿山之一，采用典型的美国碱法地浸工艺，即以CO2和O2配制溶浸剂进行浸出。介绍了Highland铀矿采用的井场设计与建设、环境评价与监测、生产操作和地下水复原等方法，以及Highland铀矿的地质概况。     

Subtle variations in the structure of crosslinked epoxy networks and the impact upon mechanical and thermal properties

Presented here is an investigation of the structure–property relationships of crosslinked networks using three bi-functional glycidyl ether aromatic epoxy resins, two bi-aryl and one tri-aryl, cured with bi- and tri-aryl amines. Subtle changes to the monomer chemistry including changing aromatic substitution patterns from meta to para, methylene to isopropyl and isopropyl to ether were explored. Changing an epoxy resin backbone from methylene to isopropyl enhances backbone rigidity thus increasing glass transition temperature (T_g), yield strength, and strain despite reducing modulus. Changing meta-substitution to para increases T_g and yield strain while leaving strength unaffected and reducing modulus. Changing isopropyl linkages to ether reduces modulus, strength, T_g, and yield strain reflecting increased molecular flexibility. Using three instead of two aromatic rings increases the molecular weight between crosslinks thereby decreasing T_g and yield strain while increasing modulus and strength. Despite the complexities of multiple systems for varying epoxy resins and amine hardeners, the effect upon network properties is explained in terms of short- and long-range molecular and segmental mobility, crosslink density, and equilibrium packing density. © 2020 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020 , 137, 48874.     

Reproductive disruption in fish downstream from an estrogenic wastewater effluent

To assess the impact of an estrogenic wastewater treatment plant (WWTP) effluent on fish reproduction, white suckers (Catostomus commersoni) were collected from immediately upstream and downstream (effluent site) of the city of Boulder, CO, WWTP outfall. Gonadal intersex, altered sex ratios, reduced gonad size, disrupted ovarian and testicular histopathology, and vitellogenin induction consistent with exposure to estrogenic wastewater contaminants were identified in white suckers downstream from the WWTP outfall and not at the upstream site. The sex ratio was female-biased at the effluent site in both the fall of 2003 and the spring of 2004; the frequency of males at the effluent site (17-21%) was half that of the upstream site (36-46%). Intersex white suckers comprised 18-22% of the population at the effluent site. Intersex fish were not found at the upstream site. Chemical analyses determined that the WWTP effluent contained a complex mixture of endocrine-active chemicals, including 17beta-estradiol (E2) 17alpha-ethynylestradiol, alkylphenols, and bisphenol A resulting in an estimated total estrogen equivalence of up to 31 ng E2 L(-1). These results indicate that the reproductive potential of native fishes may be compromised in wastewater-dominated streams.     

Factors affecting production of extracellular carbohydrate complexes by Escherichia coli O157:H7

Production of extracellular carbohydrate complexes (ECC) by foodborne pathogens on raw fruits and vegetables may result in protection against removal or inactivation by sanitizers. The influence of environmental conditions on cell growth, the total amount of ECC produced, and the amount of ECC produced on a per cell basis by Escherichia coli O157:H7 strains ATCC 43895 (wild type) and 43895-exopolysaccharides (EPS) (natural mutant, extensive EPS producer) was studied. To determine the effects of pH on the production of ECC on a per cell basis, E. coli O157:H7 was grown aerobically at 12 and 22 degrees C on tryptic soy agar (TSA) acidified to pH 7.0, 6.5, 6.0, 5.5, 5.0, 4.5, and 4.0. Lettuce, alfalfa sprout, cantaloupe, tomato, and apple juice agars (pH 4.46-6.50) were also evaluated for their support of the ECC production. Conditions generally favorable for growth of E. coli O157:H7 were a rich nutrient medium (TSA) vs. heated lettuce juice agar (HLJA) or minimal salts medium (MSM), 22 degrees C compared to 12 degrees C, and an aerobic atmosphere compared to modified atmosphere (1% O(2), 10% CO(2), and 89% N(2)). Conditions favorable for production of ECC on a per cell basis were HLJA, 12 degrees C, and an aerobic atmosphere. This suggests that modified atmosphere packaging of lettuce may not only decrease the growth of E. coli O157:H7 but also its propensity to form biofilm. There was a negative relationship between cell growth and production of ECC on a per cell basis, and environmental conditions that affected the total amount of ECC produced based on initial population reflected a combination of environmental conditions influencing both cell growth and ECC production on a per cell basis. A relative growth index factor (RGIF) was calculated to better understand ECC production as affected by various environmental conditions simultaneously. The production of ECC on a per cell basis by strain 43895-EPS showed a negative linear relationship with pH of TSA at both 12 and 22 degrees C. This strain generally produced a greater amount of ECC on fresh juice agar than on TSA at the same pH, but production of ECC on alfalfa sprout juice agar (FJA, pH 6.45) at 22 degrees C was significantly less than on TSA (pH 6.50). This indicates that nutrient limitation is not based only on nutrient availability. There may be other factors that repress the production of ECC on FJA, and the effects of those factors may be temperature dependent. Further studies will be required to better understand the relationship between nutrient availability and other factors on the production of ECC by E. coli O157:H7 on raw produce.