763 research outputs found
Cost-effective design & development of a prosthetic hand
The prosthetic hand is used to replace a missing part of a hand, which may be lost through trauma, disease, or congenital conditions in order to restore the normal functions of the hand. The state of the art design and development of prosthetic hands has been well studied and documented. The modern prosthetic hands which are computer-controlled via the means of electromyogram (EMG) signals are very helpful for amputees; however, they are expensive, not always available for low-income populations. This study presents a cost-effective solution for innovative design and development of a prosthetic hand for a patient who lost both hands due to the work accident. Design concepts of the prosthetic hand were successfully developed and tested. Different strategies for cost-effective design and development of the high-value added prosthetic hand are also discussed, including mass-customization and design for additive manufacturing
Chemoselective Installation of Amine Bonds on Proteins through Aza-Michael Ligation.
Chemical modification of proteins is essential for a variety of important diagnostic and therapeutic applications. Many strategies developed to date lack chemo- and regioselectivity as well as result in non-native linkages that may suffer from instability in vivo and adversely affect the protein's structure and function. We describe here the reaction of N-nucleophiles with the amino acid dehydroalanine (Dha) in a protein context. When Dha is chemically installed in proteins, the addition of a wide-range N-nucleophiles enables the rapid formation of amine linkages (secondary and tertiary) in a chemoselective manner under mild, biocompatible conditions. These new linkages are stable at a wide range of pH values (pH 2.8 to 12.8), under reducing conditions (biological thiols such as glutathione) and in human plasma. This method is demonstrated for three proteins and is shown to be fully compatible with disulfide bridges, as evidenced by the selective modification of recombinant albumin that displays 17 structurally relevant disulfides. The practicability and utility of our approach is further demonstrated by the construction of a chemically modified C2A domain of Synaptotagmin-I protein that retains its ability to preferentially bind to apoptotic cells at a level comparable to the native protein. Importantly, the method was useful for building a homogeneous antibody-drug conjugate with a precise drug-to-antibody ratio of 2. The kinase inhibitor crizotinib was directly conjugated to Dha through its piperidine motif, and its antibody-mediated intracellular delivery results in 10-fold improvement of its cancer cell-killing efficacy. The simplicity and exquisite site-selectivity of the aza-Michael ligation described herein allows the construction of stable secondary and tertiary amine-linked protein conjugates without affecting the structure and function of biologically relevant proteins
A comparison of Li + transport in dimethoxyethane, poly(ethylene oxide) and poly(tetramethylene oxide) by molecular dynamics simulations.
Pure dimethoxyethane (DME), poly(ethylene oxide) (PEO) and poly(tetramethylene oxide) (PTME) and their binary mixtures with LiI were investigated by molecular dynamics simulations (Li/O proportion equal to 1:8). The properties analyzed included the relative occurrence of trans and gauche population for selected torsions, radial distribution functions, mean square fluctuations and mobilities. We studied the relation between the ionic transport process of Li + and the conformational behavior in DME, PEO and PTME systems. We investigated the solvation shell around Li + in those systems. The gauche effect of DME and PEO (OCCO torsion) is strongly related to salt addition. This effect is more pronounced in DME-based systems. Li + /O co-ordination occurs in all considered systems. The mobility of the ionic species is larger in DME than in the polymers. In PTME, it is only slightly smaller than in PEO
Business networks and their effects on tourism.
O presente artigo tem como objetivo propor um modelo de alinhamento competitivo para a rede de atores do turismo, visando aumentar sua coes?o e facilitar a busca de objetivos comuns. Tal proposta foi definida com base na expertise dos autores na analise de redes de turismo, aliada a resultados obtidos na pesquisa em Ouro Preto (MG). Dessa forma, foi poss?vel perceber o peso dos atores envolvidos em fun??o dos crit?rios de escolha utilizados pelos visitantes para configurar seu caminho dentro da regi?o tur?stica analisada e, assim, refor?ar os relacionamentos existentes.The relationships between firms, to be successful, demand high levels of transparency, information and physical flows of goods and services, in order to provide free access for all people involved in doing business together. The same can be said regarding flow of money resources and talents needed by the processes and operations performed by the network. Thus, the main idea involves reaching balance conditions in terms of sharing the results obtained by all participants, considering their objectives and goals, to keep the network form of organization as being an adequate strategy. This proposal was defined from the authors? expertise in analysis of tourism networks, together with results obtained on research in Ouro Preto. Thus it was possible to realize the weight of the players involved depending on the selection criteria used by visitors to configure their way into of the tourist region analyzed and thereby strengthen existing relationships
An N-Acetyl Cysteine Ruthenium Tricarbonyl Conjugate Enables Simultaneous Release of CO and Ablation of Reactive Oxygen Species.
We have designed and synthesised a [Ru(CO)3 Cl2 (NAC)] pro-drug that features an N-acetyl cysteine (NAC) ligand. This NAC carbon monoxide releasing molecule (CORM) conjugate is able to simultaneously release biologically active CO and to ablate the concurrent formation of reactive oxygen species (ROS). Complexes of the general formulae [Ru(CO)3 (L)3 ](2+) , including [Ru(CO)3 Cl(glycinate)] (CORM-3), have been shown to produce ROS through a water-gas shift reaction, which contributes significantly, for example, to their antibacterial activity. In contrast, NAC-CORM conjugates do not produce ROS or possess antibacterial activity. In addition, we demonstrate the synergistic effect of CO and NAC both for the inhibition of nitric oxide (formation) and in the expression of tumour-necrosis factor (TNF)-α. This work highlights the advantages of combining a CO-releasing scaffold with the anti-oxidant and anti-inflammatory drug NAC in a unique pro-drug.We thank the EU (Marie Curie CIG to G.J.L.B.), FCT Portugal (FCT Investigator to G.J.L.B.; SFRH/BPD/95253/2013 to J.D.S.) and the EPSRC for funding. The NMR spectrometers are part of The National NMR Facility, supported by Fundação para a Ciência e a Tecnologia (RECI/BBB-BQB/0230/2012). G.J.L.B. is a Royal Society University Research Fellow.This is the final version of the article. It first appeared from Wiley via http://dx.doi.org/10.1002/chem.20150247
Brain-Sparing Sympathofacilitators Mitigate Obesity without Adverse Cardiovascular Effects.
Anti-obesity drugs in the amphetamine (AMPH) class act in the brain to reduce appetite and increase locomotion. They are also characterized by adverse cardiovascular effects with origin that, despite absence of any in vivo evidence, is attributed to a direct sympathomimetic action in the heart. Here, we show that the cardiac side effects of AMPH originate from the brain and can be circumvented by PEGylation (PEGyAMPH) to exclude its central action. PEGyAMPH does not enter the brain and facilitates SNS activity via theβ2-adrenoceptor, protecting mice against obesity by increasing lipolysis and thermogenesis, coupled to higher heat dissipation, which acts as an energy sink to increase energy expenditure without altering food intake or locomotor activity. Thus, we provide proof-of-principle for a novel class of exclusively peripheral anti-obesity sympathofacilitators that are devoid of any cardiovascular and brain-related side effects
Measurement of the t(t)over-bar production cross section in the dilepton channel in pp collisions at √s=8 TeV
The top-antitop quark (t (t) over bar) production cross section is measured in proton-proton collisions at root s = 8 TeV with the CMS experiment at the LHC, using a data sample corresponding to an integrated luminosity of 5.3 fb(-1). The measurement is performed by analysing events with a pair of electrons or muons, or one electron and one muon, and at least two jets, one of which is identified as originating from hadronisation of a bottom quark. The measured cross section is 239 +/- 2 (stat.) +/- 11 (syst.) +/- 6 (lum.) pb, for an assumed top-quark mass of 172.5 GeV, in agreement with the prediction of the standard model
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