A Multi-Robot Cooperation Framework for Sewing Personalized Stent Grafts

This paper presents a multi-robot system for manufacturing personalized medical stent grafts. The proposed system adopts a modular design, which includes: a (personalized) mandrel module, a bimanual sewing module, and a vision module. The mandrel module incorporates the personalized geometry of patients, while the bimanual sewing module adopts a learning-by-demonstration approach to transfer human hand-sewing skills to the robots. The human demonstrations were firstly observed by the vision module and then encoded using a statistical model to generate the reference motion trajectories. During autonomous robot sewing, the vision module plays the role of coordinating multi-robot collaboration. Experiment results show that the robots can adapt to generalized stent designs. The proposed system can also be used for other manipulation tasks, especially for flexible production of customized products and where bimanual or multi-robot cooperation is required.Comment: 10 pages, 12 figures, accepted by IEEE Transactions on Industrial Informatics, Key words: modularity, medical device customization, multi-robot system, robot learning, visual servoing, robot sewin

The Traitor

The proteolytic activation of protein kinase Cδ (PKCδ) generates a catalytic fragment called PKCδ-CF, which induces cell death. However, the mechanisms underlying PKCδ-CF-mediated cell death are largely unknown. On the basis of an engineering leukemic cell line with inducible expression of PKCδ-CF, here we employ SILAC-based quantitative phosphoproteomics to systematically and dynamically investigate the overall phosphorylation events during cell death triggered by PKCδ-CF expression. Totally, 3000 phosphorylation sites were analyzed. Considering the fact that early responses to PKCδ-CF expression initiate cell death, we sought to identify pathways possibly related directly with PKCδ by further analyzing the data set of phosphorylation events that occur in the initiation stage of cell death. Interacting analysis of this data set indicates that PKCδ-CF triggers complicated networks to initiate cell death, and motif analysis and biochemistry verification reveal that several kinases in the downstream of PKCδ conduct these networks. By analysis of the specific sequence motif of kinase-substrate, we also find 59 candidate substrates of PKCδ from the up-regulated phosphopeptides, of which 12 were randomly selected for <i>in vitro</i> kinase assay and 9 were consequently verified as substrates of PKCδ. To our greatest understanding, this study provides the most systematic analysis of phosphorylation events initiated by the cleaved activated PKCδ, which would vastly extend the profound understanding of PKCδ-directed signal pathways in cell death. The MS data have been deposited to the ProteomeXchange with identifier PXD000225

Views of surgical areas showing the conditions of RWM after different treatments.

<p>The insert of each image performed RWM in vitro correspondingly. A: control RWM freshly exposed. The RWM was partially covered by a piece of bone, which was routinely removed during surgery. B: Punctured RWM. The punctured point was covered by a small amount of fluid. C: RWM treated with 30 mg/mL collagenase I, revealing intact RWM with slight congestion. D: RWM treated with 60 mg/mL collagenase I. RWM was intact, but apparent congestion was observed in the RWM and nearby soft tissues, and a scar was seen in the middle of RWM in vitro. E: RWM treated with 90 mg/mL collagenase I, resulting in a large perforation of the RWM, indicated by the crosses. Arrow, RWM; arrowhead, stapedial artery; square, wall of the bulla; circle, lower edge of the round window niche; triangle, the perforation observed in RWM. RWM: round window membrane.</p

Inner Ear Gene Transfection in Neonatal Mice Using Adeno-Associated Viral Vector: A Comparison of Two Approaches

<div><p>Local gene transfection is a promising technique for the prevention and/or correction of inner ear diseases, particularly those resulting from genetic defects. Adeno-associated virus (AAV) is an ideal viral vector for inner ear gene transfection because of its safety, stability, long-lasting expression, and its high tropism for many different cell types. Recently, a new generation of AAV vectors with a tyrosine mutation (mut-AAV) has demonstrated significant improvement in transfection efficiency. A method for inner ear gene transfection via the intact round window membrane (RWM) has been developed in our laboratory. This method has not been tested in neonatal mice, an important species for the study of inherited hearing loss. Following a preliminary study to optimize the experimental protocol in order to reduce mortality, the present study investigated inner ear gene transfection in mice at postnatal day 7. We compared transfection efficiency, the safety of the scala tympani injection via RWM puncture, and the trans-RWM diffusion following partial digestion with an enzyme technique. The results revealed that approximately 47% of inner hair cells (IHCs) and 17% of outer hair cells (OHCs) were transfected via the trans-RWM approach. Transfection efficiency via RWM puncture (58% and 19% for IHCs and OHCs, respectively) was slightly higher, but the difference was not significant.</p> </div

Cochleograms showing transfection efficiency in the OHCs and IHCs A: trans-RWM group, B: RWM-puncture group.

<p>IHCs: inner hair cells; OHCs: outer hair cells; RWM: round window membrane.</p

Survival after surgery by experimental group.

*<p>Survival % for animals that received the surgery. Op: operated, S-op: sham operation</p

Cross-sectional view of the basal turn of cochlea showing cochlear transfection. In the trans-RWM subgroup of RWM treatment with 60 mg/mL collagenase.

<p>A–C: Strong GFP signals were observed in the IHCs, Claudius cells, membrana tectoria, spiral limbus, and spiral ligament; GFP staining was weak in the OHC (A and B). Few GFP-positive type II SGNs were found (arrows in C), and no staining was observed in type I SGNs. RWM-puncture group D–F: the relative transfection across different cell types and locations was similar to the trans-RWM group, but the GFP signal was generally stronger in the RWM-puncture group. GFP-positive type II SGNs (arrows in F). Arrowhead: type I SGNs. ScV: scala vestibule; ScT: scala tympani; ScM: scala media; OHC: outer hair cell; IHC: inner hair cell; SGNs: spiral ganglion neurons; CC: Claudius cell; DC: Deiters cell; SL: spiral ligament; SV: stria vascularis; MT: membrana tectoria; RM: Reissner's membrane; SPL: spiral limbus; NF: nerve fibers. Scale bars = 50 µm.</p

Mut-AAV-GFP transfection in the hair cells of neonatal mice 14 days postinoculation.

<p>A and B: Negative transfection in the hair cells of the collagenase 30 mg/mL group. C–E: Transfection in hair cells at different magnitudes in the collagenase 60 mg/mL subgroup, D: Apical turn, E: Basal turn. F–H: Transfection in hair cells viewed at different magnitudes in the RWM-puncture group. G: Apical turn, H: Basal turn. I: Sparse IHC transfection (arrow) seen in an ear contralateral to that receiving virus via RWM puncture. Scale bars = 50 µm. RWM: round window membrane.</p

Competition between Serum IgG, IgM, and IgA Anti-Glycan Antibodies

<div><p>Anti-glycan antibodies are an abundant subpopulation of serum antibodies with critical functions in many immune processes. Changes in the levels of these antibodies can occur with the onset of disease, exposure to pathogens, or vaccination. As a result, there has been significant interest in exploiting anti-glycan antibodies as biomarkers for many diseases. Serum contains a mixture of anti-glycan antibodies that can recognize the same antigen, and competition for binding can potentially influence the detection of antibody subpopulations that are more relevant to disease processes. The most abundant antibody isotypes in serum are IgG, IgM, and IgA, but little is known regarding how these different isotypes compete for the same glycan antigen. In this study, we developed a multiplexed glycan microarray assay and applied it to evaluate how different isotypes of anti-glycan antibodies (IgA, IgG, and IgM) compete for printed glycan antigens. While IgG and IgA antibodies typically outcompete IgM for peptide or protein antigens, we found that IgM outcompete IgG and IgA for many glycan antigens. To illustrate the importance of this effect, we provide evidence that IgM competition can account for the unexpected observation that IgG of certain antigen specificities appear to be preferentially transported from mothers to fetuses. We demonstrate that IgM in maternal sera compete with IgG resulting in lower than expected IgG signals. Since cord blood contains very low levels of IgM, competition only affects maternal IgG signals, making it appear as though certain IgG antibodies are higher in cord blood than matched maternal blood. Taken together, the results highlight the importance of competition for studies involving anti-glycan antibodies.</p></div

Dependence of inhibition on carbohydrate antigen structure.

<p>Measured IgG signals to Forssman disaccharide and tetrasaccharide (A) and four blood group A antigens (B) in the absence of added IgM (0 μg/mL) or in the presence of varying amounts of IgM (50–400 μg/mL).</p