Novel design of a soft lightweight pneumatic continuum robot arm with decoupled variable stiffness and positioning

Soft robot arms possess unique capabilities when it comes to adaptability, flexibility and dexterity. In addition, soft systems that are pneumatically actuated can claim high power to weight ratio. One of the main drawbacks of pneumatically actuated soft arms is that their stiffness cannot be varied independently from their end-effector position in space. The novel robot arm physical design presented in this paper successfully decouples its end-effector positioning from its stiffness. An experimental characterisation of this ability is coupled with a mathematical analysis. The arm combines the light weight, high payload to weight ratio and robustness of pneumatic actuation with the adaptability and versatility of variable stiffness. Light weight is a vital component of the inherent safety approach to physical human-robot interaction. In order to characterise the arm, a neural network analysis of the curvature of the arm for different input pressures is performed. The curvature-pressure relationship is also characterised experimentally

Design, fabrication and control of soft robots

Conventionally, engineers have employed rigid materials to fabricate precise, predictable robotic systems, which are easily modelled as rigid members connected at discrete joints. Natural systems, however, often match or exceed the performance of robotic systems with deformable bodies. Cephalopods, for example, achieve amazing feats of manipulation and locomotion without a skeleton; even vertebrates such as humans achieve dynamic gaits by storing elastic energy in their compliant bones and soft tissues. Inspired by nature, engineers have begun to explore the design and control of soft-bodied robots composed of compliant materials. This Review discusses recent developments in the emerging field of soft robotics.National Science Foundation (U.S.) (Grant IIS-1226883

All-trans-retinoic-acid and arsenic trioxide induced remission in promyelocytic blast crisis

A 78-year-old-male with chronic myeloid leukemia (CML) treated for seven years with dasatinib developed an acute promyelocytic leukemia complicated by disseminated intravascular coagulopathy. A promyelocytic blast crisis was diagnosed by demonstrating co-expression of chimeric BCL/ABL and PML/RARα translocations by karyotyping, fluorescence in situ hybridization, and quantitative real-time polymerase chain reaction. Promyelocytic blast crisis of CML is a rare event with historically poor outcomes. Treatment of our patient with all-trans-retinoic acid (ATRA) and arsenic trioxide (ATO) resulted in complete morphologic remission. We review here the relevant literature of promyelocytic blast crisis and highlight the potential of ATRA/ATO as first line management. Keywords: ATRA, ATO, CML, Promyelocytic, Blast crisi

The effect of different clays on the structure, morphology and degradation behavior of poly (lactic acid)

In this work, polylacticacid(PLA) based nanocomposites \ufb01lled with different kinds of clay were prepared and their structure, morphology and degradation behavior were compared. A similar degree of dispersion was achieved in the case of cationic and anionic clays. However, these two types of \ufb01llers had different effects on the structure and morphology. Perkalite, ananionic clay, induced higher crystallinity, a faster crystallization rate and also a modi\ufb01cation of the crystallization mechanism. Moreover, when perkalite was used, the lamellar framework of PLA was preserved. Cationic clays, on the other hand, were detrimental for a regular crystallization of the PLA matrix, producing very disordered lamellar stacks. The effects of anionic and cationic clays were different also on the degradation behavior, with the perkalite-containing nanocomposite degrading much faster than either the matrix or the montmorillonite-reinforced materials. This comparison shows that a rational choice of the chemical nature of the nano\ufb01ller allows to tune both the degradation rate of PLA and its structure

Electrospun nylon fibers for the improvement of mechanical properties and for the control of degradation rate of poly(lactide)-based composites

Poly(lactide) (PLA) composites filled with electrospun nylon 6 fibers were prepared. This allowed to simultaneously improve the mechanical properties and tune the degradation of the PLA matrix. The interfacial adhesion between the PLA matrix and the nylon fibers was very good. The major effect of electrospun fibers on the matrix was that of modifying the semicrystalline framework, thickening the polymer lamellae. This allowed increasing the mechanical properties of the material, and on the other hand to modify its degradation rate. The modulus of the composites was increased up to 3-fold with respect to neat PLA. The peculiar morphology of matrix-filler interaction moreover slowed down the degradation rate of the material and improved the dimensional stability of the specimens during the degradation process. This shows the potential of electrospun fibers as a way to tune the durability of PLA-based products, widening the range of application of this promising material

TAFRO syndrome: A case report and review of the literature

TAFRO syndrome is a rare clinicopathologic variant of idiopathic multicentric Castleman disease characterized by Thrombocytopenia, Ascites (anasarca), myeloFibrosis, Renal dysfunction, and Organomegaly. Here, we report a case of TAFRO syndrome in an HIV-negative young Caucasian male who presented with fever, normocytic anemia, thrombocytopenia, and acute renal insufficiency. The serum interleukin-6 (IL-6) level was elevated. Chest and abdominal CT revealed bilateral pleural effusion, ascites, splenomegaly, and multiple mildly enlarged lymph nodes. An excisional biopsy of inguinal lymph node showed a few atrophic follicles and expansion of interfollicular areas by marked vascular proliferation and polytypic plasmacytosis. HHV-8 was negative. Subsequent bone marrow biopsy was normocellular with moderately increased megakaryocytes and occasional megakaryocytic emperipolesis. His signs and symptoms improved after treatment with methylprednisolone and tocilizumab (anti-IL-6 receptor antibody). Our study confirms the distinctive nature of this syndrome, which should allow for better recognition and appropriate therapy. Keywords: Castleman-Kojima disease, TAFRO syndrome, Idiopathic multicentric Castleman disease, IL-6, HHV-