16 research outputs found
Nucleation of a sodium droplet on C60
We investigate theoretically the progressive coating of C60 by several sodium
atoms. Density functional calculations using a nonlocal functional are
performed for NaC60 and Na2C60 in various configurations. These data are used
to construct an empirical atomistic model in order to treat larger sizes in a
statistical and dynamical context. Fluctuating charges are incorporated to
account for charge transfer between sodium and carbon atoms. By performing
systematic global optimization in the size range 1<=n<=30, we find that Na_nC60
is homogeneously coated at small sizes, and that a growing droplet is formed
above n=>8. The separate effects of single ionization and thermalization are
also considered, as well as the changes due to a strong external electric
field. The present results are discussed in the light of various experimental
data.Comment: 17 pages, 10 figure
Risk profiles and one-year outcomes of patients with newly diagnosed atrial fibrillation in India: Insights from the GARFIELD-AF Registry.
BACKGROUND: The Global Anticoagulant Registry in the FIELD-Atrial Fibrillation (GARFIELD-AF) is an ongoing prospective noninterventional registry, which is providing important information on the baseline characteristics, treatment patterns, and 1-year outcomes in patients with newly diagnosed non-valvular atrial fibrillation (NVAF). This report describes data from Indian patients recruited in this registry. METHODS AND RESULTS: A total of 52,014 patients with newly diagnosed AF were enrolled globally; of these, 1388 patients were recruited from 26 sites within India (2012-2016). In India, the mean age was 65.8 years at diagnosis of NVAF. Hypertension was the most prevalent risk factor for AF, present in 68.5% of patients from India and in 76.3% of patients globally (P < 0.001). Diabetes and coronary artery disease (CAD) were prevalent in 36.2% and 28.1% of patients as compared with global prevalence of 22.2% and 21.6%, respectively (P < 0.001 for both). Antiplatelet therapy was the most common antithrombotic treatment in India. With increasing stroke risk, however, patients were more likely to receive oral anticoagulant therapy [mainly vitamin K antagonist (VKA)], but average international normalized ratio (INR) was lower among Indian patients [median INR value 1.6 (interquartile range {IQR}: 1.3-2.3) versus 2.3 (IQR 1.8-2.8) (P < 0.001)]. Compared with other countries, patients from India had markedly higher rates of all-cause mortality [7.68 per 100 person-years (95% confidence interval 6.32-9.35) vs 4.34 (4.16-4.53), P < 0.0001], while rates of stroke/systemic embolism and major bleeding were lower after 1 year of follow-up. CONCLUSION: Compared to previously published registries from India, the GARFIELD-AF registry describes clinical profiles and outcomes in Indian patients with AF of a different etiology. The registry data show that compared to the rest of the world, Indian AF patients are younger in age and have more diabetes and CAD. Patients with a higher stroke risk are more likely to receive anticoagulation therapy with VKA but are underdosed compared with the global average in the GARFIELD-AF. CLINICAL TRIAL REGISTRATION-URL: http://www.clinicaltrials.gov. Unique identifier: NCT01090362
Resposta tecidual a implantes de discos de poliuretana de mamona nas formas pré-moldada ou biomassa moldada Tissue reaction to premolded or molded biomass disks of polyurethanes containing castor oil
O trabalho teve por objetivo avaliar a resposta tecidual à implantação de discos de poliuretana derivada do óleo de mamona confeccionados de duas formas distintas, na forma pré-moldada fornecida pela indústria e em biomassa moldada no momento da aplicação, de forma a observar se haveria algum tipo de reação local tardia associada à possível continuidade do processo de endurecimento final do biomaterial. Foram utilizados 20 ratos, linhagem Wistar, fêmeas, com peso de 300-350g, nos quais foi inserido o disco pré-moldado no tecido subcutâneo do flanco direito e o de biomassa moldada no flanco esquerdo. Ambos os discos tinham 0,8cm de diâmetro por 0,5cm de espessura. Para o procedimento histológico, cinco ratos foram submetidos à eutanásia aos 3, 7, 15 e 30 dias de pós-cirúrgico. Os implantes e tecidos circundantes foram colhidos, processados e corados pela técnica de hematoxilina-eosina. Foi observada inicialmente uma reação inflamatória moderada, composta especialmente por células polimorfonucleares e macrófagos. Os linfócitos variaram de ausentes a discretos. A reação inflamatória diminui de intensidade à medida que se intensificou a formação de tecido conjuntivo fibroso ao redor dos implantes, porém sem modificação dos números de macrófagos. Sendo assim, conclui-se que ambos os discos de poliuretana induzem uma reação inflamatória similar, que varia de moderada a discreta na dependência do momento de avaliação.<br>The aim of this study was to histologically evaluate the tissue reaction to implantation of polyurethane disks containing castor oil produced in premolded form, supplied commercially, and biomass molded at the moment of application; since a late tissue reaction may occur during the total hardening process of the biomaterial. Twenty female Wistar rats, about 3 months of age, weighing 300-350g, and polyurethane disks 0.8cm in diameter and 0.5cm in thickness were used. The premolded disk was implanted into the subcutaneous tissue at the right flank and the molded biomass disk at the left flank. Five rats each were submitted to euthanasia at 3, 7, 15 and 30 days after surgery, and the polyurethane disks and surrounding tissue were collected. The specimens were processed for HE staining and examined microscopically. A moderate inflammatory reaction was primarily composed of polymorphonuclear cells and macrophages. The lymphocytes varied from absent to discreet. The intensity of the inflammatory reaction decreased at the same time the formation of fibrous conjunctive tissue increased around the implants. However, the numbers of macrophages remained the same. In conclusion, both polyurethane disks induce the same type of inflammatory reaction that varies from slight to moderate according to evaluation time
Análise clínica, radiológica, macroscópica e histológica do úmero de codornas domésticas (Coturnix japonica), submetido ao implante da poliuretana derivada do polímero de mamona (Ricinnus communis) Clinical, radiological, macroscopical and histological analysis of domestic quail (Coturnix japonica) humerus submitted to implant of polyurethane from castor oil polymer (Ricinnus communis)
Na cirurgia ortopédica, são freqüentes as situações em que o cirurgião se depara com grandes perdas ósseas, provocadas especialmente por traumatismos de alta energia, tumores ou infecções. A reparação dessas fraturas requer grande conhecimento a respeito de materiais que possam ser utilizados para preencher essas falhas. Esses materiais podem ser derivados biológicos, sintéticos ou metálicos. Dentre eles, destacam-se os enxertos ósseos e os implantes de biomateriais. Com o aumento dos animais exóticos, utilizados como animais de estimação, a casuística clínica e cirúrgica dessa especialidade vem crescendo, tanto em clínicas quanto em hospitais veterinários. Particularmente, as aves constituem a maioria desses animais, e entre seus problemas cirúrgicos as fraturas são os de maior destaque. O objetivo deste trabalho foi estudar o efeito clínico, radiológico, macroscópico e histológico da poliuretana derivada do polímero de mamona (Ricinnus communis) implantada no úmero de codornas domésticas (Coturnix japonica). Para isso, foram utilizadas 20 codornas, machos e fêmeas, separadas aleatoriamente em quatro grupos de cinco animais, os quais receberam o implante no úmero esquerdo, com exame clínico diário durante o período pós-operatório, avaliações radiológica imediata e quinzenal e macroscópica e histológica aos 15, 30, 60 e 90 dias. Clinicamente não foram observadas alterações locais, regionais nem sistêmicas. Ao exame radiológico, notou-se aumento de densidade local, sem sinais de alteração óssea, dos tecidos circunjacentes, e de sacos aéreos. A análise macroscópica revelou que a poliuretana de mamona não foi absorvida em nenhum dos quatro grupos permanecendo implantada no seio do osso pneumático, porém, notou-se alteração em sua resistência. O exame histopatológico mostra inicialmente mínima reação inflamatória, discreta fibrose ao redor do implante e osteointegração pela presença de trabéculas e medula óssea no interior do implante. Concluiu-se que a poliuretana derivada do polímero de mamona é biocompatível em aves, podendo ser utilizada na cirurgia ortopédica, ocorrendo osteointegração.<br>In orthopedic surgery there are frequently situations in which the surgeon faces severe bone losses caused by high-energy trauma, tumors or infections. Repairing these losses require knowledge about filling materials. Those materials can be biological, synthetic or metallic, with emphasis in bony grafts and biomaterial implants. The increase of the use of birds as pets is leading to an increasing number of clinical and surgical cases related to this taxon, where fractures are the most commonly observed surgical problems. The objective of this study was to evaluate clinical, radiological, macroscopic and microscopic effects of the polyurethane derived from castor oil (Ricinus communis) polymer, when implanted in the humerus of domestic quails (Coturnix japonica). Twenty male and female quails, were used randomly distributed in four groups of five individuals. The birds received the implants in the left humerus, being submitted to daily physical examination during the postoperative period, immediate and biweekly radiological examination, and macroscopic and microscopic evaluation at the 15th, 30th, 60th and 90th days. Clinically, there were not observed local, regional or systemic changes. Radiologically, increase in local density was observed with no signs of changes in bone or adjacent tissue, as well as in the air sacs. Macroscopic analysis revealed that the polyurethane derived from castor oil polymer was not absorbed in none of the four groups, remaining implanted within the pneumatic bone. Its resistance, however, has changed. Microscopic examination evidenced minimum inflammatory reaction, slight fibrosis around the implants, and osteo-integration with presence of trabeculi and bone marrow inside the implants. Concluding, implants of polyurethane derived from castor oil polymer are biocompatible in quails, with occurrence of osteo-integration, and can be used in orthopedic surgery in this species