Universidade Federal de Minas Gerais

About: Universidade Federal de Minas Gerais is a education organization based out in Belo Horizonte, Minas Gerais, Brazil. It is known for research contribution in the topics: Population & Immune system. The organization has 41631 authors who have published 75688 publications receiving 1249905 citations.

What do we know about multicomponent reactions? Mechanisms and trends for the Biginelli, Hantzsch, Mannich, Passerini and Ugi MCRs

Abstract: The current manuscript describes the importance, mechanism propositions, evidence and controversies associated with multicomponent reactions (MCRs). The following multicomponent reactions are presented and critically evaluated: the Biginelli, Hantzsch, Mannich, Passerini and Ugi reactions. The aim of this review is to highlight what we already know about the mechanisms associated with these MCRs and the evidence supporting the proposed reaction pathways. Controversies and prospects are also discussed herein.

Systemic and regional hemodynamic effects of angiotensin-(1–7) in rats

Abstract: The systemic and regional hemodynamics effects of ANG-(1–7) were examined in urethane-anesthetized rats. The blood flow distribution (kidneys, skin, mesentery, lungs, spleen, brain, muscle, and adr...

Brazilian Protected Areas

Abstract: Although Brazil's first park was established in 1937, the past two decades have witnessed an explosion of protected areas. Until 1989 federal parks and reserves were created by the Brazilian Forest De- velopment Institute (IBDF) and the Special Secretariat for the Environment (SEMA). In 1989 SEMA and IBDF were united to form the Brazilian Institute for the Environment and Renewable Natural Resources (IBAMA). Af ormal, unified system for federal, state, and municipal parks, the National System for Protected Areas, was made law in 2000. In 1976 IBDF drew up a biogeographical model for siting protected areas for biodiversity conservation in the Amazon, based on representation of phytogeographic regions. There are three ongoing initiatives to determine the location of new protected areas: (1) protected areas were recommended for the majority of 900 priority areas for biodiversity conservation identified in workshops held for Brazil's major biomes (1998-2000); (2) establishment of biodiversity corridors with parks and reserves as key elements; and (3) the creation of protected areas in the 23 Amazonian ecoregions identified by World Wildlife Fund—Brazil (the ARPA program). Federal and state strictly protected areas now number 478 and total 37,019,697 ha, and there are 436 sustainable-use areas totalling 74,592,691 ha. Other categories of protected areas in Brazil include private natural heritage reserves (RPPNs), which are generally small but proving important for the conservation of restricted-range and highly threatened species, and indigenous reserves, which are increasingly recognized as vital for biodiversity conservation because of their enormous size. Although Brazil has created an enormous number of protected areas over the last two decades, enormous challenges remain—not only for their administration and management—but also to protect the parks themselves as Brazil continues with its ambitious developmental programs for energy, infrastructure, industry, and agriculture. ´

Muscle strengthening is not effective in children and adolescents with cerebral palsy: a systematic review

Abstract: Question: Do strengthening interventions increase strength without increasing spasticity and improve activity, and is there any carryover after cessation in children and adolescents with cerebral palsy? Design: Systematic review with meta-analysis of randomised trials. Participants: Children with spastic cerebral palsy between school age and 20 years. Intervention: Strengthening interventions that involved repetitive, strong, or effortful muscle contractions and progressed as ability changed, such as biofeedback, electrical stimulation, and progressive resistance exercise. Outcome measures: Strength was measured as continuous measures of maximum voluntary force or torque production. Spasticity was measured as velocity-dependent resistance to passive stretch. Activity was measured as continuous measures, eg, 10-m Walk Test, or using scales eg, the Gross Motor Function Measure. Results: Six studies were identified and five had data that could be included in a metaanalysis. Strengthening interventions had no effect on strength (SMD 0.20, 95% CI –0.17 to 0.56), no effect on walking speed (MD 0.02 m/s, 95% CI –0.13 to 0.16), and had a small statistically-significant but not clinically-worthwhile effect on Gross Motor Function Measure (MD 2%, 95% CI 0 to 4). Only one study measured spasticity but did not report the between-group analysis. Conclusion: In children and adolescents with cerebral palsy who are walking, the current evidence suggests that strengthening interventions are neither effective nor worthwhile. [Scianni A, Butler JM, Ada L, Teixeira-Salmela LF (2009) Muscle strengthening is not effective in children with cerebral palsy: a systematic review. Australian Journal of Physiotherapy 55: 81–87]

Direct transfer of graphene onto flexible substrates

Abstract: In this paper we explore the direct transfer via lamination of chemical vapor deposition graphene onto different flexible substrates. The transfer method investigated here is fast, simple, and does not require an intermediate transfer membrane, such as polymethylmethacrylate, which needs to be removed afterward. Various substrates of general interest in research and industry were studied in this work, including polytetrafluoroethylene filter membranes, PVC, cellulose nitrate/cellulose acetate filter membranes, polycarbonate, paraffin, polyethylene terephthalate, paper, and cloth. By comparing the properties of these substrates, two critical factors to ensure a successful transfer on bare substrates were identified: the substrate’s hydrophobicity and good contact between the substrate and graphene. For substrates that do not satisfy those requirements, polymethylmethacrylate can be used as a surface modifier or glue to ensure successful transfer. Our results can be applied to facilitate current processes and open up directions for applications of chemical vapor deposition graphene on flexible substrates. A broad range of applications can be envisioned, including fabrication of graphene devices for opto/organic electronics, graphene membranes for gas/liquid separation, and ubiquitous electronics with graphene.