Collision-free motion of two robot arms in a common workspace

Collision-free motion of two robot arms in a common workspace is investigated. A collision-free motion is obtained by detecting collisions along the preplanned trajectories using a sphere model for the wrist of each robot and then modifying the paths and/or trajectories of one or both robots to avoid the collision. Detecting and avoiding collisions are based on the premise that: preplanned trajectories of the robots follow a straight line; collisions are restricted to between the wrists of the two robots (which corresponds to the upper three links of PUMA manipulators); and collisions never occur between the beginning points or end points on the straight line paths. The collision detection algorithm is described and some approaches to collision avoidance are discussed

Bar-grid oscillators

Grid oscillators are an attractive way of obtaining high power levels from the solid-state devices, since potentially the output powers of thousands of individual devices can be combined. The active devices do not require an external locking signal, and the power combining is done in free space. Thirty-six transistors were mounted on parallel brass bars, which provide a stable bias and have a low thermal resistance. The output power degraded gradually when the devices failed. The grid gave an effective radiated power of 3 W at 3 GHz. The directivity was 11.3 dB, and the DC-to-RF efficiency was 22%. Modulation capabilities of the grid were demonstrated. An equivalent circuit model for the grid is derived, and comparison with experimental results is shown

Quasi-optical power-combining arrays

Semiconductor devices have limited power handling capabilities at high frequencies, particularly at millimeter-wave frequencies. A method is presented for overcoming this problem by combining the outputs of several devices quasi-optically in a resonator cavity. This method has been applied to a number of solid-state devices, including Gunn diodes and MESFETs. The devices do not require an external locking signal because they lock to a mode of the resonator cavity. Effective radiated powers of 22 watts for a 4×4 array of Gunn diodes and 25 watts for a 10×10 array of MESFETs have been achieved

A Bisphosphonate With a Low Hydroxyapatite Binding Affinity Prevents Bone Loss in Mice After Ovariectomy and Reverses Rapidly With Treatment Cessation

Bisphosphonates (BPs) are a mainstay of osteoporosis treatment; however, concerns about bone health based on oversuppression of remodeling remain. Long-term bone remodeling suppression adversely affects bone material properties with microdamage accumulation and reduced fracture toughness in animals and increases in matrix mineralization and atypical femur fractures in patients. Although a “drug holiday” from BPs to restore remodeling and improve bone quality seems reasonable, clinical BPs have long functional half-lives because of their high hydroxyapatite (HAP) binding affinities. This places a practical limit on the reversibility and effectiveness of a drug holiday. BPs with low HAP affinity and strong osteoclast inhibition potentially offer an alternative approach; their antiresorptive effect should reverse rapidly when dosing is discontinued. This study tested this concept using NE-58025, a BP with low HAP affinity and moderate osteoclast inhibition potential. Young adult female C57Bl/6 mice were ovariectomized (OVX) and treated with NE-58025, risedronate, or PBS vehicle for 3 months to test effectiveness in preventing long-term bone loss. Bone microarchitecture, histomorphometry, and whole-bone mechanical properties were assessed. To test reversibility, OVX mice were similarly treated for 3 months, treatment was stopped, and bone was assessed up to 3 months post-treatment. NE-58025 and RIS inhibited long-term OVX-induced bone loss, but NE-58025 antiresorptive effects were more pronounced. Withdrawing NE-58025 treatment led to the rapid onset of trabecular resorption with a 200% increase in osteoclast surface and bone loss within 1 month. Cessation of risedronate treatment did not lead to increases in resorption indices or bone loss. These results show that NE-58025 prevents OVX-induced bone loss, and its effects reverse quickly following cessation treatment in vivo. Low-HAP affinity BPs may have use as reversible, antiresorptive agents with a rapid on/off profile, which may be useful for maintaining bone health with long-term BP treatment

Comparison of Proteomic Assessment Methods in Multiple Cohort Studies

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/155922/1/pmic13292_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/155922/2/pmic13292.pd

Analysis and Functional Consequences of Increased Fab-Sialylation of Intravenous Immunoglobulin (IVIG) after Lectin Fractionation

It has been proposed that the anti-inflammatory effects of intravenous immunoglobulin (IVIG) might be due to the small fraction of Fc-sialylated IgG. In this study we biochemically and functionally characterized sialic acid-enriched IgG obtained by Sambucus nigra agglutinin (SNA) lectin fractionation. Two main IgG fractions isolated by elution with lactose (E1) or acidified lactose (E2) were analyzed for total IgG, F(ab’)2 and Fc-specific sialic acid content, their pattern of specific antibodies and anti-inflammatory potential in a human in vitro inflammation system based on LPS- or PHA-stimulated whole blood. HPLC and LC-MS testing revealed an increase of sialylated IgG in E1 and more substantially in the E2 fraction. Significantly, the increased amount of sialic acid residues was primarily found in the Fab region whereas only a minor increase was observed in the Fc region. This indicates preferential binding of the Fab sialic acid to SNA. ELISA analyses of a representative range of pathogen and auto-antigens indicated a skewed antibody pattern of the sialylated IVIG fractions. Finally, the E2 fraction exerted a more profound anti-inflammatory effect compared to E1 or IVIG, evidenced by reduced CD54 expression on monocytes and reduced secretion of MCP-1 (CCL2); again these effects were Fab- but not Fc-dependent. Our results show that SNA fractionation of IVIG yields a minor fraction (approx. 10%) of highly sialylated IgG, wherein the sialic acid is mainly found in the Fab region. The tested anti-inflammatory activity was associated with Fab not Fc sialylation

Common Genetic Polymorphisms Influence Blood Biomarker Measurements in COPD

Implementing precision medicine for complex diseases such as chronic obstructive lung disease (COPD) will require extensive use of biomarkers and an in-depth understanding of how genetic, epigenetic, and environmental variations contribute to phenotypic diversity and disease progression. A meta-analysis from two large cohorts of current and former smokers with and without COPD [SPIROMICS (N = 750); COPDGene (N = 590)] was used to identify single nucleotide polymorphisms (SNPs) associated with measurement of 88 blood proteins (protein quantitative trait loci; pQTLs). PQTLs consistently replicated between the two cohorts. Features of pQTLs were compared to previously reported expression QTLs (eQTLs). Inference of causal relations of pQTL genotypes, biomarker measurements, and four clinical COPD phenotypes (airflow obstruction, emphysema, exacerbation history, and chronic bronchitis) were explored using conditional independence tests. We identified 527 highly significant (p 10% of measured variation in 13 protein biomarkers, with a single SNP (rs7041; p = 10−392) explaining 71%-75% of the measured variation in vitamin D binding protein (gene = GC). Some of these pQTLs [e.g., pQTLs for VDBP, sRAGE (gene = AGER), surfactant protein D (gene = SFTPD), and TNFRSF10C] have been previously associated with COPD phenotypes. Most pQTLs were local (cis), but distant (trans) pQTL SNPs in the ABO blood group locus were the top pQTL SNPs for five proteins. The inclusion of pQTL SNPs improved the clinical predictive value for the established association of sRAGE and emphysema, and the explanation of variance (R2) for emphysema improved from 0.3 to 0.4 when the pQTL SNP was included in the model along with clinical covariates. Causal modeling provided insight into specific pQTL-disease relationships for airflow obstruction and emphysema. In conclusion, given the frequency of highly significant local pQTLs, the large amount of variance potentially explained by pQTL, and the differences observed between pQTLs and eQTLs SNPs, we recommend that protein biomarker-disease association studies take into account the potential effect of common local SNPs and that pQTLs be integrated along with eQTLs to uncover disease mechanisms. Large-scale blood biomarker studies would also benefit from close attention to the ABO blood group

FGF-2 promotes osteocyte differentiation through increased E11/podoplanin expression

E11/podoplanin is critical in the early stages of osteoblast-to-osteocyte transitions (osteocytogenesis) however the upstream events which regulate E11 expression are unknown. The aim of this study was to examine the effects of FGF-2 on E11-mediated osteocytogenesis and to reveal the nature of the underlying signaling pathways regulating this process. Exposure of MC3T3 osteoblast-like cells and murine primary osteoblasts to FGF-2 (10ng/ml) increased E11 mRNA and protein expression (

Gene expression analysis suggests that EBF-1 and PPAR gamma 2 induce adipogenesis of NIH-3T3 cells with similar efficiency and kinetics

Differentiation of multipotent mesenchymal stem cells into lipid-accumulating adipocytes is a physiological process induced by transcription factors in combination with hormonal stimulation. We have used Affymetrix microarrays to compare the adipogenic differentiation pathways of NIH-3T3 fibroblasts induced to undergo in vitro differentiation by ectopic expression of early B cell factor (EBF)-1 or peroxisome proliferator-activated receptor (PPAR)gamma 2. These experiments revealed that commitment to the adipogenic pathway in the NIH-3T3 cells was not reflected in gene expression until 4 days after induction of differentiation. Furthermore, gene expression patterns at the earlier time points after stimulation indicated that EBF-1 and PPAR gamma 2 induced different sets of genes, while the similarities increased upon differentiation, and that several genes linked to adipocyte differentiation were also transiently induced in the vector-transduced cells. These data suggest that the initial activation of genes associated with adipocyte development is independent of commitment to the adipogenic pathway and that EBF-1 and PPAR gamma 2 induce adipocyte differentiation with comparable kinetics and efficiency