1,393 research outputs found
Robots in Industry. Past,present and future of a growing collaboration with humans
Robots have been part of automation systems for a very long time, and in public perception, they are often synonymous with automation and industrial revolution perse. Fueled by Industry 4.0 and Internet of Things (IoT) concepts as well as by new software technologies, the field of robotics in industry is currently undergoing a revolution on its own. This article gives an overview of the evolution of robotics from its beginnings to recent trends like collaborative robotics, autonomous robots, and human- robot interaction. Particular attention is devoted to the deep changes of the last decades, from the traditional industrial scenario based on isolated robotic cells up to the most recent coworking and collaborative robots. The role of robotics in the Industry 4.0 framework is analyzed, and the relationships with industrial communications and software technologies are also discussed. Some future directions for robotics are envisaged, focusing on the contributions coming from new materials, sensors, actuators, and technologies. Open issues are highlighted as well as the main barriers that currently limit the deployment of industrial robots in the small and medium enterprise (SME) world
Catalytic mechanism and role of hydroxyl residues in the active site of theta class Glutathione-S-Transferases: Investigation of Ser-9 and Tyr-113 in a Glutathione S-Transferase from the australian sheep blowfly Lucilia cuprina
Abstract Spectroscopic and kinetic studies have been performed on the Australian sheep blowfly Lucilia cuprina glutathione S-transferase (Lucilia GST; EC 2.5.1.18) to clarify its catalytic mechanism. Steady state kinetics of Lucilia GST are non-Michaelian, but the quite hyperbolic isothermic binding of GSH suggests that a steady state random sequential Bi Bi mechanism is consistent with the anomalous kinetics observed. The rate-limiting step of the reaction is a viscosity-dependent physical event, and stopped-flow experiments indicate that product release is rate-limiting. Spectroscopic and kinetic data demonstrate thatLucilia GST is able to lower the pK a of the bound GSH from 9.0 to about 6.5. Based on crystallographic suggestions, the role of two hydroxyl residues, Ser-9 and Tyr-113, has been investigated. Removal of the hydroxyl group of Ser-9 by site-directed mutagenesis raises the pK a of bound GSH to about 7.6, and a very low turnover number (about 0.5% of that of wild type) is observed. This inactivation may be explained by a strong contribution of the Ser-9 hydroxyl group to the productive binding of GSH and by an involvement in the stabilization of the ionized GSH. This serine residue is highly conserved in the Theta class GSTs, so the present findings may be applicable to all of the family members. Tyr-113 appears not to be essential for the GSH activation. Stopped-flow data indicate that removal of the hydroxyl group of Tyr-113 does not change the rate-limiting step of reaction but causes an increase of the rate constants of both the formation and release of the GSH conjugate. Tyr-113 resides on α-helix 4, and its hydroxyl group hydrogen bonds directly to the hydroxyl of Tyr-105. This would reduce the flexibility of a protein region that contributes to the electrophilic substrate binding site; segmental motion of α-helix 4 possibly modulates different aspects of the catalytic mechanism of theLucilia GST
Interaction of glutathione transferase from horse erythrocytes with 7-chloro-4-nitrobenzo-2-oxa-1,3-diazole
7-Chloro-4-nitrobenzo-2-oxa-1,3-diazole reacts with two thiol groups of the dimeric horse erythrocyte glutathione transferase at pH 5.0, with strong inactivation reversible on dithiothreitol treatment. The inactivation kinetic follows a biphasic pattern, similar to that caused by other thiol reagents as recently reported. Both S-methylglutathione and 1-chloro-2,4-dinitrobenzene protect the enzyme from inactivation. Analysis of the reactive SH group-containing peptide gives the sequence Ala-Ser-Cys-Leu-Tyr, identical with that of the peptide that contains the reactive cysteine 47 of the human placental transferase. In the presence of glutathione, the enzyme is not inactivated by this reagent, but it catalyzes its conjugation to glutathione. At higher pH values, 7-chloro-4-nitrobenzo-2-oxa-1,3-diazole reacts with 2 tyrosines/dimer and lysines, as well as with cysteines. Reaction with lysine seems essentially without effect on activity; whether the reactive tyrosines are important for activity could not be determined using this reagent only. However, 2 tyrosines among the 4 that are nitrated by tetranitro-methane are important for activity
Glutathione transferases and glutathionylated hemoglobin in workers exposed to low doses of 1,3-butadiene.
We evaluated glutathione transferase (GST) activities and the levels of glutathionylated hemoglobin in the
RBCof 42 workers exposed to 1,3-butadiene in a petrochemical plant, using 43 workers not exposed to
1,3-butadiene and 82 foresters as internal and external controls, respectively. Median 1,3-butadiene exposure levels were 1.5, 0.4, and 0.1 Mg/m3 in 1,3-butadieneexposed
workers, in workers not directly exposed to 1,3-butadiene, and in foresters, respectively. In addition,
we determined in the peripheral blood lymphocytes of the same individuals the presence of GST polymorphic genes GSTT1 and GSTM1 and the distribution of GSTP1 allelic variants. Comparing the mean values observed in petrochemical workers
with those of control foresters, we found a marked decrease of GST enzymatic activity and a significant
increase of glutathionylated hemoglobin in the petrochemical workers. A weak but significant negative correlation was found between levels of 1,3-butadiene exposure and GST activity, whereas a positive
correlation was found between 1,3-butadiene exposure
and glutathionylated hemoglobin. A negative correlation was also observed between GST activity and glutathionylated hemoglobin. No influence of confounders was observed. Using a multiple linear regression model, up to 50.6% and 41.9% of the
variability observed in glutathionylated hemoglobin
and GST activity, respectively, were explained by 1,3- butadiene exposure, working setting, and GSTT1 genotype. These results indicate that occupational
exposure to 1,3-butadiene induces an oxidative stress that impairs the GST balance in RBC, and suggest that GST activity and glutathionylated hemoglobin
could be recommended as promising biomarkers of effect in petrochemical workers
Inherently chiral, highly electroactive macrocyclic oligothiophenes: a new class with a "Portfolio" of outstanding potentialities
We have recently introduced1,2,3 an entirely new class of chiral oligothiophene macrocycles, easily accessible by either chemical or electrochemical oxidation of monomers, like the BT2-T4 one in Figure 1 (taken from ref. 3), endowed with "inherent chirality". Such property stems from a tailored torsion in the main conducting backbone,1,2 corresponding to a high rotational energy barrier. Thus the monomer can be separated into stable enantiopure antipodes, whose chirality is entirely transferred to the corresponding cyclic oligomers.
The new molecules possess an uncommon pool of outstanding properties even as racemates. For example:
\ub7 they idealize conducting polymers without end, that is, without defectivity connected with free terminals;
\ub7 in CV and EIS experiments they exhibit very fast and reversible electron transfer and charge transport;
\ub7 their HOMO and LUMO levels, which are modulable with the multiplicity and length of the monomer units in the cyclic oligomer, appear convenient for application in devices like bulk heterojunction solar cells;
\ub7 they are electrochromic;
\ub7 they exhibit (negative) photocurrent activity.
Most impressive, however, are the properties as enantiopure antipodes, possibly as a consequence of the unique coincidence of the source of both chirality and electroactivity with the entire main conducting backbone, which affords inter alia to reversibly modulate chiroptical properties by electrochemical polarization.
The enantiopure oligomers exhibit:
\ub7 impressive optical rotatory power;
\ub7 impressive circular dichroism signals, which can be finely and reversibly modulated by the electrical potential ("breathing chirality");
\ub7 remarkable circularly polarized luminescence (CPL);
\ub7 outstanding enantiorecognition ability.
In particular, we have recently highlighted3 their applicative potentialities as low-cost and easy-to-prepare artificial enantiopure electrode surfaces, which display an unprecedented ability to pronouncedly separate voltammetry peaks of enantiomers of quite different chiral probes, including the model ferrocenyl one in Figure 2 (adapted from ref. 2, and where 3 stays for the BT2-T4 cyclic trimer), or of applicative interest (e.g. pharmaceutical ones like DOPA, Figure 3 from ref. 3), concurrently with linear dynamic ranges for peak currents, affording enantiomer excess determination, particularly on disposable SPEs, testing small drops of enantiomer solutions.
It is also remarkable that, while usual chiral recognition methods are based on selectors of natural origin and therefore available as a single enantiomer, this approach offers availability of both selector enantiomers.
Thus inherently chiral enantiopure electrodes can indeed be regarded as a key to chiral voltammetry.
With the contribution of Fondazione Cariplo, grant no.2011-0417
Patent deposited MI2014A000948-23/05/2014
References:
[1] F. Sannicol\uf2, P.R. Mussini, T. Benincori, S. Arnaboldi, M. Panigati, E. Quartapelle Procopio et al., Chem. Eur. J. 2014, 20, 15298 \u2013 15302.
[2] F. Sannicol\uf2, S. Arnaboldi, T. Benincori, P.R. Mussini, M. Panigati et al., Angew. Chem. Int. Ed. 2014, 53, 2623 \u20132627.
[3] S. Arnaboldi, T. Benincori, R. Cirilli, W. Kutner, M. Magni, P.R. Mussini, K. Noworyta, F. Sannicol\uf2, Chemical Science, 2015, 6, 1706\u20131711
Anti-Angiogenic Therapy Induces Integrin-Linked Kinase 1 Up-Regulation in a Mouse Model of Glioblastoma
BACKGROUND: In order to improve our understanding of the molecular pathways that mediate tumor proliferation and angiogenesis, and to evaluate the biological response to anti-angiogenic therapy, we analyzed the changes in the protein profile of glioblastoma in response to treatment with recombinant human Platelet Factor 4-DLR mutated protein (PF4-DLR), an inhibitor of angiogenesis. METHODOLOGY/PRINCIPAL FINDINGS: U87-derived experimental glioblastomas were grown in the brain of xenografted nude mice, treated with PF4-DLR, and processed for proteomic analysis. More than fifty proteins were differentially expressed in response to PF4-DLR treatment. Among them, integrin-linked kinase 1 (ILK1) signaling pathway was first down-regulated but then up-regulated after treatment for prolonged period. The activity of PF4-DLR can be increased by simultaneously treating mice orthotopically implanted with glioblastomas, with ILK1-specific siRNA. As ILK1 is related to malignant progression and a poor prognosis in various types of tumors, we measured ILK1 expression in human glioblastomas, astrocytomas and oligodendrogliomas, and found that it varied widely; however, a high level of ILK1 expression was correlated to a poor prognosis. CONCLUSIONS/SIGNIFICANCE: Our results suggest that identifying the molecular pathways induced by anti-angiogenic therapies may help the development of combinatorial treatment strategies that increase the therapeutic efficacy of angiogenesis inhibitors by association with specific agents that disrupt signaling in tumor cells
Granulysin, a novel marker for extranodal NK/T cell lymphoma, nasal type
Granulysin is a cytolytic protein expressed in cytotoxic T and natural killer (NK) cells. Abnormal serum levels of granulysin in lymphomas with NK and cytotoxic phenotype have been shown to correlate with tumour progression. In this study, we investigated the expression pattern of granulysin in routine sections of normal and reactive lymphoid tissues as well as in a large series of lymphomas. In normal tissues, granulysin labelled a small population of cells that double immunostaining revealed to belong to the pool of cytotoxic T/NK cells. Among lymphoid neoplasms, the highest expression of granulysin (71%) was found in extranodal NK/T cell lymphomas of nasal type (ENKTL). To note is that 29% of ENKTLs, which were negative for one or more of classical cytotoxic markers strongly expressed granulysin. Furthermore, expression of granulysin was observed in rare cases of T cell lymphomas with a cytotoxic phenotype (i.e. ALK-negative anaplastic large cell lymphoma (26%), enteropathy-associated T cell lymphoma (12%) and peripheral T cell lymphoma, NOS (4%)). None of the investigated non-Hodgkin B cell lymphomas, Hodgkin lymphoma and plasma cell myeloma were granulysin positive. The results suggest granulysin as a novel marker for a subset of cytotoxic NK cell derived malignancies and its usefulness is highlighted in those ENKTLs that lack expression of other cytotoxic markers but retain granulysin expression
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