Visitantes florais do algodoeiro Gossypium hirsutum em Quixeramobim e Quixeré no Estado do Ceará.

O objetivo deste estudo foi investigar os visitantes florais em áreas de algodoeiro comercial, cultivar 187 8R, nos municípios de Quixeramobim e Quixeré, Ceará

RAFT aqueous dispersion polymerization yields poly(ethylene glycol)-based diblock copolymer nano-objects with predictable single phase morphologies

A poly(ethylene glycol) (PEG) macromolecular chain transfer agent (macro-CTA) is prepared in high yield (>95%) with 97% dithiobenzoate chain-end functionality in a three-step synthesis starting from a monohydroxy PEG113 precursor. This PEG113-dithiobenzoate is then used for the reversible addition-fragmentation chain transfer (RAFT) aqueous dispersion polymerization of 2-hydroxypropyl methacrylate (HPMA). Polymerizations conducted under optimized conditions at 50 °C led to high conversions as judged by 1H NMR spectroscopy and relatively low diblock copolymer polydispersities (Mw/Mn < 1.25) as judged by GPC. The latter technique also indicated good blocking efficiencies, since there was minimal PEG113 macro-CTA contamination. Systematic variation of the mean degree of polymerization of the core-forming PHPMA block allowed PEG113-PHPMAx diblock copolymer spheres, worms, or vesicles to be prepared at up to 17.5% w/w solids, as judged by dynamic light scattering and transmission electron microscopy studies. Small-angle X-ray scattering (SAXS) analysis revealed that more exotic oligolamellar vesicles were observed at 20% w/w solids when targeting highly asymmetric diblock compositions. Detailed analysis of SAXS curves indicated that the mean number of membranes per oligolamellar vesicle is approximately three. A PEG 113-PHPMAx phase diagram was constructed to enable the reproducible targeting of pure phases, as opposed to mixed morphologies (e.g., spheres plus worms or worms plus vesicles). This new RAFT PISA formulation is expected to be important for the rational and efficient synthesis of a wide range of biocompatible, thermo-responsive PEGylated diblock copolymer nano-objects for various biomedical applications

Controlled Radical Polymerization of Vinyl Acetate Mediated by a Bis(imino)pyridine Vanadium Complex

Source type: Prin

Polymerization-Induced Self-Assembly of Block Copolymer Nano-objects via RAFT Aqueous Dispersion Polymerization

In this Perspective, we discuss the recent development of polymerization-induced self-assembly mediated by reversible addition–fragmentation chain transfer (RAFT) aqueous dispersion polymerization. This approach has quickly become a powerful and versatile technique for the synthesis of a wide range of bespoke organic diblock copolymer nano-objects of controllable size, morphology, and surface functionality. Given its potential scalability, such environmentally-friendly formulations are expected to offer many potential applications, such as novel Pickering emulsifiers, efficient microencapsulation vehicles, and sterilizable thermo-responsive hydrogels for the cost-effective long-term storage of mammalian cells

Chain transfer kinetics of acid/base switchable n-aryl- n-pyridyl dithiocarbamate RAFT agents in methyl acrylate, n-vinylcarbazole and vinyl acetate polymerization

This is an accepted manuscript of an article published by American Chemistry Society in Macromolecules on 14/05/2012, available online: https://doi.org/10.1021/ma300616g ©American Chemical Society. The accepted version of the publication may differ from the final published version.The structures of the "Z" and "R" substituents of a RAFT agent (Z-C(S)S-R) determine a RAFT agent's ability to control radical polymerization. In this paper we report new acid/base switchable N-aryl-N-pyridyl dithiocarbamates (R = -CH 2CN, Z = -N(Py)(Ar)) which vary in substituent at the 4-position of the aryl ring and the use of these to control molecular weight and dispersity. In their protonated form, the new RAFT agents are more effective in controlling polymerization of the more activated monomer, methyl acrylate (MA), whereas in their neutral form they provide more effective control of the polymerization of less activated monomers, N-vinyl carbazole (NVC) and vinyl acetate (VAc). For each polymerization, the apparent chain transfer coefficient (C trapp) shows a good correlation with Hammett parameters. Dithiocarbamates with more electron-withdrawing aryl ring substituents have the higher C trapp. This demonstrates the influence of polar effects on C trapp and supports the hypothesis that the activity of these RAFT agents is determined by the availability of the lone pair of the dithiocarbamate nitrogen.The authors gratefully acknowledge the Capability Development Fund of CSIRO Materials Science and Engineering for financial support.Published versio

Alquimia, Ocultismo, Maçonaria: o ouro e o simbolismo hermético dos cadinhos (Séculos XVIII e XIX)

Este artigo apresenta a arqueologia das enigmáticas marcas impressas na base de cadinhos dos séculos XVIII e XIX recuperados nas escavações da Casa da Moeda do Rio de Janeiro, na década de 1980, e a explanação do seu significado simbólico à luz da alquimia, do ocultismo e da Maçonaria. Espraiando-se extraordinariamente mundo afora através de uma bem-sucedida estratégia de comunicação visual, a Maçonaria utilizou símbolos herméticos para a difusão de seus princípios nos mais diferentes suportes. Aparentemente estamos diante de um sinal de reconhecimento maçônico, o sinal exterior de uma organização oculta, só partilhado por iniciados e incompreensível para os demais, que contribuiu para difundir veladamente a doutrina maçônica por diferentes pontos do globo

Low-back pain at the emergency department: still not being managed?

Alessandro Rizzardo,1 Luca Miceli,1 Rym Bednarova,2 Giovanni Maria Guadagnin,1 Rodolfo Sbrojavacca,3 Giorgio Della Rocca11Department of Anesthesia and Intensive Care, Academic Hospital of Udine, University of Udine, Udine, 2Pain Medicine and Palliative Care, Health Company Number 2, Gorizia, 3Emergency Department, Academic Hospital of Udine, Udine, ItalyBackground: Low-back pain (LBP) affects about 40% of people at some point in their lives. In the presence of &ldquo;red flags&rdquo;, further tests must be done to rule out underlying problems; however, biomedical imaging is currently overused. LBP involves large in-hospital and out-of-hospital economic costs, and it is also the most common musculoskeletal disorder seen in emergency departments (EDs).Patients and methods: This retrospective observational study enrolled 1,298 patients admitted to the ED, including all International Classification of Diseases 10 diagnosis codes for sciatica, lumbosciatica, and lumbago. We collected patients&rsquo; demographic data, medical history, lab workup and imaging performed at the ED, drugs administered at the ED, ED length of stay (LOS), numeric rating scale pain score, admission to ward, and ward LOS data. Thereafter, we performed a cost analysis.Results: Mean numeric rating scale scores were higher than 7/10. Home medication consisted of no drug consumption in up to 90% of patients. Oxycodone&ndash;naloxone was the strong opioid most frequently prescribed for the home. Once at the ED, nonsteroidal anti-inflammatory drugs and opiates were administered to up to 72% and 42% of patients, respectively. Imaging was performed in up to 56% of patients. Mean ED LOS was 4 hours, 14 minutes. A total of 43 patients were admitted to a ward. The expense for each non-ward-admitted patient was approximately &euro;200 in the ED, while the mean expense for ward-admitted patients was &euro;9,500, with a mean LOS of 15 days.Conclusion: There is not yet a defined therapeutic care process for the patient with LBP with clear criteria for an ED visit. It is to this end that we need a clinical pathway for the prehospital management of LBP syndrome and consequently for an in-hospital time-saving therapeutic approach to the patient.Keywords: low-back pain, health policies, emergency department, cost analysi