Experimental modeling of hypoxia in pregnancy and early postnatal life

The important role of equilibrium of environmental factors during the embryo-fetal period is undisputable. Women of reproductive age are increasingly exposed to various environmental risk factors such as hypoxia, prenatal viral infections, use of drugs, smoking, complications of birth or stressful life events. These early hazards represent an important risk for structural and/or functional maldevelopment of the fetus and neonates. Impairment of oxygen/energy supply during the pre- and perinatal period may affect neuronal functions and induce cell death. Thus when death of the newborn is not occurring following intrauterine hypoxia, various neurological deficits, including hyperactivity, learning disabilities, mental retardation, epilepsy, cerebral palsy, dystonia etc., may develop both in humans and in experimental animals. In our animal studies we used several approaches for modeling hypoxia in rats during pregnancy and shortly after delivery, i.e. chronic intrauterine hypoxia induced by the antiepileptic drug phenytoin, neonatal anoxia by decreased oxygen saturation in 2-day-old pups. Using these models we were able to test potential protective properties of natural (vitamin E, melatonin) and synthetic (stobadine) compounds. Based on our results, stobadine was also able to reduce hypoxia-induced hyperactivity and the antioxidant capacity of stobadine exceeded that of vitamin E and melatonin, and contrary to vitamin E, stobadine had no adverse effects on developing fetus and offspring

Harnessing the potential of ligninolytic enzymes for lignocellulosic biomass pretreatment

Abundant lignocellulosic biomass from various industries provides a great potential feedstock for the production of value-added products such as biofuel, animal feed, and paper pulping. However, low yield of sugar obtained from lignocellulosic hydrolysate is usually due to the presence of lignin that acts as a protective barrier for cellulose and thus restricts the accessibility of the enzyme to work on the cellulosic component. This review focuses on the significance of biological pretreatment specifically using ligninolytic enzymes as an alternative method apart from the conventional physical and chemical pretreatment. Different modes of biological pretreatment are discussed in this paper which is based on (i) fungal pretreatment where fungi mycelia colonise and directly attack the substrate by releasing ligninolytic enzymes and (ii) enzymatic pretreatment using ligninolytic enzymes to counter the drawbacks of fungal pretreatment. This review also discusses the important factors of biological pretreatment using ligninolytic enzymes such as nature of the lignocellulosic biomass, pH, temperature, presence of mediator, oxygen, and surfactant during the biodelignification process

Functional brain mapping at 9.4T using a new MRI-compatible electrode chronically implanted in rats

There is a need for acute and chronic stimulation of the brain within the MRI for studies of epilepsy, as well as of deep brain stimulation for movement and behavioral disorders. This paper describes the production and characteristics of carbon fiber based electrodes for acute and chronic stimulation in the brain. Increasing MRI field strengths are making it increasingly difficult to introduce foreign objects without a susceptibility artifact. This paper describes the production of, and the characteristics of carbon fiber based electrodes. These are biocompatible and can be implanted for chronic studies. We show the use of these electrodes at 9.4T for studying functional activation. Data are presented showing regional connectivity. Activation not only occurs near the electrode, but at sites distant and often contralateral to the electrode. In addition, there were sites showing strong negative activation to stimulation both with direct stimulation and during a kindling associated seizure.Peer reviewed: YesNRC publication: Ye

Manejo químico de Cyperus rotundus na cultura da cana-de-açúcar Chemical control of Cyperus rotundus on sugar-cane crop

Avaliou-se neste trabalho o efeito de doses (1,0, 1,5 e 2,0 kg ha-1) e épocas de aplicação (pré ou pós-emergência) da mistura comercial ametryn + trifloxysulfuron-sodium no controle de Cyperus rotundus, na cultura da cana-de-açúcar, em comparação com 1,0 kg ha-1pré + 1,0 kg ha-1 pós-emergência dessa mistura, 0,90 kg ha-1 de sulfentrazone em pré-emergência, além das testemunhas com e sem capina. Maior efeito na redução de massa seca de C. rotundus foi proporcionado pelos tratamentos 1,0 kg ha-1 pré + 1,0 kg ha-1 pós e 2,0 kg ha-1 em pós-emergência da mistura comercial de ametryn + trifloxysulfuron-sodium, respectivamente, com percentual médio de controle visual verificado nesses tratamentos de 86,8%. Quanto aos efeitos sobre o número de manifestações epígeas de C. rotundus, com exceção do tratamento de 2,0 kg ha-1 em pós-emergência, os correspondentes às aplicações em pré-emergência da mistura foram mais eficientes na sua redução. Todavia, o sulfentrazone isolado ou a menor dose de 1,0 kg ha-1 de ametryn + trifloxysulfuron-sodium em pré-emergência apresentaram baixa eficiência na redução de C. rotundus, com média de controle visual inferior a 40%. Embora, nas aplicações em pré-emergência, a dose estimada de 1,25 kg ha-1 não tenha diferido de 2,0 kg ha-1 da mistura comercial, na redução da massa seca da parte aérea de C. rotundus, a aplicação em pós-emergência de 2,0 kg ha-1 apresentou efeito significativo em relação às demais doses, com ação prolongada no controle dessa espécie. Todos os tratamentos avaliados foram seletivos para a cana-de-açúcar, variedade RB 72454.<br>This work evaluated the effect of doses (1.0, 1.5, and 2.0 kg ha-1) and periods of spraying (pre and post-emergence) of ametryn + trifloxysulfuron-sodium commercial mixture to Cyperus rotundus control, in sugar-cane crop, compared to 1.0 kg ha-1 pre + 1.0 kg ha-1 postemergence of the same mixture, 0.90 kg ha-1 of sulfentrazone in pre-emergence, besides the treatments with and without weeding. A greater effect in dry mass reduction of C. rotundus was provided by the treatments 1.0 kg ha-1 pre + 1.0 kg ha-1 post and 2.0 kg ha-1 of ametryn + trifloxysulfuron-sodium post-emergence commercial mixture, respectively, as the average percentage of visual control verified in those treatments was 86.8%. About the effects on shoot number of C. rotundus, except for the treatment (2.0 kg ha-1) in post-emergence, the pre emergence treatments of the mixture were more efficient in reducing it. Yet, only sulfentrazone or the smallest dose 1.0 kg ha-1 of ametryn + trifloxysulfuron-sodium in pre-emergence showed low efficiency on C. rotundus reduction, with average visual control lowe than 40%. Although, in pre-emergence applications, the estimated dose of 1.25 kg ha-1 did not differ from 2.0 kg ha-1 of the commercial mixture, in reducing dry mass of the aerial part of C. rotundus, the application of 2.0 kg ha-1 post-emergence presented significant effect, compared to the other doses, with remaining action control of this species. None of the treatments evaluated affected sugar-cane, variety RB 72454