An evaluation of ruminally degradable intake protein and metabolizable amino acid requirements of feedlot calves

Ruminally degradable intake protein (DIP) and metabolizable indispensable amino acid (MIAA) requirements of feedlot steers were evaluated. Dietary treatments consisted of isocaloric 80% concentrate steam-flaked corn-based diets containing either .8% urea, 1.5% fish meal (FM), 3.0% FM, 4.5% FM, or 4.5% soybean meal (SBM). Treatment effects on characteristics of ruminal and total tract digestion were evaluated using four Holstein steers (249 kg) with cannulas in the rumen and proximal duodenum. Ruminal digestibility of OM (RDOM; P < .05) and feed N (P < .01) and microbial N flow (MNF; P < .01) to the small intestine were greater with urea as the supplemental N source. The level of DIP was closely associated (R2 = .89) with MNF. Postruminal digestibility of OM was greater (P < .05) for FM than for urea-supplemented diets, compensating for lower RDOM. There were no treatment effects (P > .10) on DOM. As the level of FM was increased, MIAA increased linearly (P < .01). Intestinal MIAA were similar (P > .10) for urea- and SBM-supplemented diets. Treatment effects on 56-d growth performance were evaluated using 100 medium-framed crossbred steers (231 kg). Daily weight gain (linear effect; P < .01), DM intake (linear effect; P < .10), feed efficiency (linear effect; P < .05), and diet NE (linear effect; P < .05) increased with level of FM supplementation. Daily weight gain (P < .10) and DM intake (P < .05) were greater for urea- than for SBM-supplemented diets. Using bovine tissue as the reference protein, the biological value (based on chemical score) of the intestinal chyme protein averaged 73%; methionine was first-limiting. There was a close association (R2 = .99) between methionine supply to the small intestine and observed/expected dietary NE. The metabolizable methionine requirement (MMETR, g/d) of medium-framed feedlot steers can be reliably predicted from measures of BW and ADG (MMETR = 1.565 + .0234ADG[268 - (29.4 x .0557BW(.75)ADG(1.097))/ADG] + .0896BW(.75)). There was a very close association (R2 = .89) between DIP and MNF (MNF = 13.7DIP - .66DIP(2) + 25.9). At maximal observed synthesis, DIP accounted for 76% of the MNF. A minimum of 100 g DIP/kg of total tract digestible OM was required to maximize RDOM and MNF.     

Tyrosine kinase inhibition produces specific alterations in axon guidance in the grasshopper embryo

Tyrosine kinase signaling pathways are essential for process outgrowth and guidance during nervous system development. We have examined the roles of tyrosine kinase activity in programming growth cone guidance decisions in an intact nervous system in which neurons can be individually identified. We applied the tyrosine kinase inhibitors herbimycin A and genistein to whole 40% grasshopper embryos placed in medium, or injected the inhibitors into intact grasshopper eggs. Both inhibitors caused interneuronal axons that normally would grow along the longitudinal connectives to instead leave the central nervous system (CNS) within the segmental nerve root and grow out toward the body wall muscles. In addition, herbimycin A produced pathfinding errors in which many longitudinal axons crossed the CNS midline. To study how this drug affected guidance decisions made by individual growth cones, we dye-filled the pCC interneuron, which normally extends an axon anteriorly along the ipsilateral longitudinal connective. In the presence of herbimycin A, the pCC growth cone was redirected across the anterior commissure. These phenotypes suggest that tyrosine kinase inhibition blocks a signaling mechanism that repels the growth cones of longitudinal connective neurons and prevents them from crossing the midline.     

Nanocopper Based Solder-Free Electronic Assembly

CuantumFuse nano copper material has been used to assemble functional LED test boards and a small camera board with a 48 pad CMOS sensor quad-flat no-lead chip and a 10 in flexible electronics demo. Drop-in replacement of solder, by use of stencil printing and standard surface mount technology equipment, has been demonstrated. Applications in space and commercial systems are currently under consideration. The stable copper-nanoparticle paste has been examined and characterized by scanning electron microscopy and high-resolution transmission electron microscopy; this has shown that the joints are nanocrystalline but with substantial porosity. Assessment of reliability is expected to be complicated by this and by the effects of thermal and strain-enhanced coarsening of pores. Strength, creep, and fatigue properties were measured and results are discussed with reference to our understanding of solder reliability to assess the potential of this nano-copper based solder alternative.     

Ultrathin Polydopamine Films with Phospholipid Nanodiscs Containing a Glycophorin A Domain

Cellular membranes have long served as an inspiration for nanomaterial research. The preparation of ultrathin polydopamine (PDA) films with integrated protein pores containing phospholipids and an embedded domain of a membrane protein glycophorin A as simplified cell membrane mimics is reported. Large area, ultrathin PDA films are obtained by electropolymerization on gold surfaces with 10–18 nm thickness and dimensions of up to 2.5 cm². The films are transferred from gold to various other substrates such as nylon mesh, silicon, or substrates containing holes in the micrometer range, and they remain intact even after transfer. The novel transfer technique gives access to freestanding PDA films that remain stable even at the air interfaces with elastic moduli of ≈6–12 GPa, which are higher than any other PDA films reported before. As the PDA film thickness is within the range of cellular membranes, monodisperse protein nanopores, so‐called “nanodiscs,” are integrated as functional entities. These nanodisc‐containing PDA films can serve as semi‐permeable films, in which the embedded pores control material transport. In the future, these simplified cell membrane mimics may offer structural investigations of the embedded membrane proteins to receive an improved understanding of protein‐mediated transport processes in cellular membranes.     

Analysis of microRNAs in Exosomes of Breast Cancer Patients in Search of Molecular Prognostic Factors in Brain Metastases

Brain metastases are the most severe tumorous spread during breast cancer disease. They are associated with a limited quality of life and a very poor overall survival. A subtype of extracellular vesicles, exosomes, are sequestered by all kinds of cells, including tumor cells, and play a role in cell-cell communication. Exosomes contain, among others, microRNAs (miRs). Exosomes can be taken up by other cells in the body, and their active molecules can affect the cellular process in target cells. Tumor-secreted exosomes can affect the integrity of the blood-brain barrier (BBB) and have an impact on brain metastases forming. Serum samples from healthy donors, breast cancer patients with primary tumors, or with brain, bone, or visceral metastases were used to isolate exosomes and exosomal miRs. Exosomes expressed exosomal markers CD63 and CD9, and their amount did not vary significantly between groups, as shown by Western blot and ELISA. The selected 48 miRs were detected using real-time PCR. Area under the receiver-operating characteristic curve (AUC) was used to evaluate the diagnostic accuracy. We identified two miRs with the potential to serve as prognostic markers for brain metastases. Hsa-miR-576-3p was significantly upregulated, and hsa-miR-130a-3p was significantly downregulated in exosomes from breast cancer patients with cerebral metastases with AUC: 0.705 and 0.699, respectively. Furthermore, correlation of miR levels with tumor markers revealed that hsa-miR-340-5p levels were significantly correlated with the percentage of Ki67-positive tumor cells, while hsa-miR-342-3p levels were inversely correlated with tumor staging. Analysis of the expression levels of miRs in serum exosomes from breast cancer patients has the potential to identify new, non-invasive, blood-borne prognostic molecular markers to predict the potential for brain metastasis in breast cancer. Additional functional analyzes and careful validation of the identified markers are required before their potential future diagnostic use.     

Growth hormone response to growth hormone releasing hormone in calves that differ in genetic merit for milk yield

Holstein heifer, steer, and bull calves from control (CL) and select (SL) lines of cows that differed by more than 4000 kg of milk during a 305-d lactation (SL > CL) were used to determine growth hormone (GH) response to 5 doses of GH releasing hormone (GHRH) and how this response was affected by gender, period (age), and genetic merit for milk yield. Doses (0, 2.5, 5, 10, and 20 microg/100 kg of BW) of a GHRH analog were assigned randomly to each heifer (4 CL, 4 SL), steer (4 CL, 4 SL), and bull (3 CL, 3 SL) calf and administered on consecutive days at approximately 3, 6, and 10 mo of age (periods; P1, P2, and P3). Jugular blood samples (n = 15) collected between -30 and 240 min relative to GHRH administration were used to quantify area under the GH response curve (AUC) after subtracting mean prechallenge GH concentrations. Estimates of maximum response (Rmax) and sensitivity (ED50) to GHRH were obtained from the hyperbolic dose response curves (AUC vs. dose). Data were analyzed for effects of dose, line, period, gender, and their interactions with period as the repeated effect. Prechallenge GH concentrations were not affected by genetic line, gender, or period. The AUC was not affected by line, but decreased with period and increased with GHRH dose. The Rmax did not differ between lines or among genders, but decreased with period. The ED50 did not differ between lines or among periods, but heifers were more sensitive to GHRH than steers or bulls. Although GH response to GHRH has been identified as a potential indicator of genetic merit, it did not differ between these substantially different genetic lines.     

Reduction of the elongation at break of thermoplastic polyolefins through melt blending with polylactide and the influence of the amount of compatibilizers and the viscosity ratios of the blend components on phase morphology and mechanics

The objective of this work is the synthesis of a polypropylene/ethylene‐propylene‐rubber (TPO)/polylactide (PLA)/compatibilizer (PVM) blend to reduce the elongation at break of TPO by blending TPO with brittle PLA. Three TPO types with different viscosities were melt blended with PLA and an ethylene/n‐butylacrylate/glycidyl methacrylate terpolymer (PVM) as reactive compatibilizer. All blends had a constant PLA amount of 30 wt%. Two parameters were varied in the experiments, viscosity of the TPO types, and amount of PVM used in the blends. Both parameters played important roles in reducing the nominal elongation at break compared to pure TPO foils and influencing the phase morphology of extruded blend foils. The nominal elongation at break could be reduced by 100‐150% through blending TPO with PLA and PVM. Characterization regarding the blend morphology, especially the size and shape of the dispersed PLA phase in the TPO matrix was done by Environmental Scanning Electron Microscopy (ESEM) images. Investigations of the morphology showed that size and shape of dispersed PLA phases are dependent on the viscosity ratios of the blend components and on the amount of compatibilizer in the blend. AFM images of the polymer blends reveal soft rubbery layers around the dispersed PLA phases. POLYM. ENG. SCI., 56:905–913, 2016. © 2016 Society of Plastics Engineers     

Efficient Modular Synthesis of Isomeric Mono‐ and Bispyridyl[2.2]paracyclophanes by Palladium‐Catalyzed Cross‐ Coupling Reactions

Pyridyl‐substituted [2.2]paracyclophanes build a multifunctional structural motif that is useful in material chemistry, catalysis and for luminescent structures. Nonetheless, there is still a lack of general methods for the synthesis of these structures tolerating easily accessible bromides as well as different isomeric pyridyl groups. Hence the coupling of functionalized [2.2]paracyclophanes with various substituted and functionalized pyridyl derivatives was achieved using Stille, Suzuki and Kumada coupling conditions. Hereby the Stille coupling of a [2.2]paracyclophane is presented as a versatile reaction for the formation of heteromeric [2.2]paracyclophane‐containing biaryl structures.