Solvent resistant nanofiltration membranes

This thesis describes preparation and characterization of membranes for\ud organic solvent filtration (OSF). The main aim was developing membranes for\ud solvent resistant nanofiltration (SRNF) with molecular weight cut-off below 500 g mol-1

Exposure to Stressful Life Events and Lung Cancer Risk

Objectif: Examiner l’association entre l'exposition aux évènements stressants de la vie et le cancer du poumon. Méthodes: Les données proviennent d’une étude cas-témoins, menée chez les hommes et les femmes vivant dans la région métropolitaine de Montréal entre 1996 et 2001. Le cancer du poumon d’un cas éligible devait être confirmé histologiquement à l’un des 18 hôpitaux de cette région. Les témoins ont été sélectionnés aléatoirement de la liste électorale du Québec et ont été appariés au cas par fréquence de groupes d'âge et par sexe. Un questionnaire a été administré en entrevue pour recueillir les données, dont l’évaluation de huit évènements stressants de la vie par le participant. Si le participant avait vécu un évènement stressant ciblé durant les six dernières années, il devait aussi coter cet évènement sur une échelle de trois points. La régression logistique non conditionnelle a été utilisée pour estimer les rapports de cotes ainsi que leurs intervalles de confiance à 95%. Des analyses par sexe, niveau de tabagisme et par type histologique ont été réalisées. Nous avons aussi analysé l’association entre le cancer du poumon et le nombre total d'évènements, les évènements de perte et les évènements socioéconomiques, ainsi que chaque évènement individuellement. Les analyses des scores d'impact autoévalués et avec un score externe de perception, ont également été menées. Résultats: La population de ce projet comprend 1061 cas et 1422 témoins, âgés de 35 à 70 ans. Les participants inclus avaient répondu aux sections du questionnaire portant sur les facteurs de style de vie et sur l'historique de tabagisme. Dans l'ensemble, nous n’avons pas observé d’association entre le cancer du poumon et l'exposition aux évènements stressants de la vie. Nous avons observé une diminution du risque pour les évènements socioéconomiques autoévalués comme peu stressants (RC=0,50; IC 95%= 0,31 - 0,81). Conclusion: Nos résultats suggèrent que les évènements socioéconomiques sont associées à un risque réduit si ces évènements sont considérés comme peu stressant.Objective: To examine exposure to stressful life events in relation to lung cancer risk. Methods: Our research used data from a case-control study conducted in Montreal from 1996 to 2001. Cases were diagnosed with histologically confirmed incident lung cancer at one of 18 Montreal-area hospitals. Controls were randomly selected from the Quebec electoral list and frequency matched to the distribution of cases by sex and 5 year age groups. Data was collected on sociodemographic characteristics, lifetime smoking, and lifestyle factors including 8 stressful life events. Participants indicated the stressful life events they experienced over the past six years, and an appraisal of their level of stress due to each event on a three-point scale. Unconditional logistic regression was used to estimate adjusted odds ratios and 95% confidence intervals. Each stressful life event was analyzed individually as well as in grouped variables measuring total number of events, loss events and socioeconomic events. Analyses of self-appraised impact scores were also conducted; additionally an external perceived stress score was also employed. Results: 1061 cases and 1422 population controls were included in the analyses. Overall, we observed no association between lung cancer and stressful life events. A decrease in risk for socioeconomic events self-appraised as not very stressful was observed (OR, 0.50; 95% CI, 0.31, 0.81), which included job loss, increase in debt, and move to another city. Conclusion: Our results suggest that socioeconomic events, deemed not very stressful, may reduce the risk of lung cancer

Paper Session II-C - Measuring the Concerns of Teachers: A Possible Means for Evaluating the Efficacy of Kennedy Space Center Teacher Enhancement Workshops

In-service teacher enhancement workshops are held as part of the NASA teacher preparation and enhancement programs. For these workshops, teachers are brought to NASA field centers during summer months for training in various aerospace related areas. The National Research Council, Committee on NASA Education Program Outcomes (NEPO) has recommended comprehensive data collection to show program efficacy. Teacher workshops are a part of the nearly 300 NASA educational programs for students and teachers from pre-school through post-graduate, and NEPO has made specific recommendations for the evaluation of the teacher workshops. In accordance with one recommendation, a questionnaire was administered during four of the summer 1995 teacher workshops to measure participant concerns about using workshop material (space science) in their classes. Participant responses to the questions reflect changes in concerns relative to using workshop materials in teaching. (Work performed under NASA contract: NAS1O-1218O

Категорія двоїни і становлення морфологічної норми української мови

У статті простежено вплив граматичної категорії двоїни на становлення морфологічної норми сучасної української літературної мови.The research presents an analysis of grammatical category of plural number with pair meaning. The main trends of morphological norm in literary Ukrainian have been generalised

The Role of Endogenous Neuroprotective Mechanisms in the Prevention of Retinal Ganglion Cells Degeneration

Retinal neurons are not able to undergo spontaneous regeneration in response to damage. A variety of stressors, i.e., UV radiation, high temperature, ischemia, allergens, and others, induce reactive oxygen species production, resulting in consecutive alteration of stress-response gene expression and finally can lead to cell apoptosis. Neurons have developed their own endogenous cellular protective systems. Some of them are preventing cell death and others are allowing functional recovery after injury. The high efficiency of these mechanisms is crucial for cell survival. In this review we focus on the contribution of the most recently studied endogenous neuroprotective factors involved in retinal ganglion cell (RGC) survival, among which, neurotrophic factors and their signaling pathways, processes regulating the redox status, and different pathways regulating cell death are the most important. Additionally, we summarize currently ongoing clinical trials for therapies for RGC degeneration and optic neuropathies, including glaucoma. Knowledge of the endogenous cellular protective mechanisms may help in the development of effective therapies and potential novel therapeutic targets in order to achieve progress in the treatment of retinal and optic nerve diseases

Electrical synapses interconnecting axons revealed in the optic nerve head – a novel model of gap junctions’ involvement in optic nerve function

Abstract Purpose To characterize newly discovered electrical synapses, formed by connexin (Cx) 36 and 45, between neighbouring axons within the optic nerve head. Methods Twenty-five Wistar rats were killed by CO2 inhalation. Proximal and distal optic nerve (ON) stumps were collected and processed for immunostainings, electron microscopy (EM) with immunogold labelling, PCR and Western blots (WB). Additional 15 animals were deeply anaesthetized, and flash visual evoked potentials (fVEP) after retrobulbar injection of saline (negative control) or 100 ?m meclofenamic acid solution (gap junctions? blocker) were recorded. Human paraffin cross-sections of eyeballs for immunostainings were obtained from the Human Eye Biobank for Research. Results Immunostainings of both rat and human ON revealed the presence of Cx45 and 36 colocalizing with ?3-tubulin, but not with glial fibrillary acidic protein (GFAP). In WB, Cx36 content in optic nerve was approximately halved when compared with retina (0.58 ± 0.005 in proximal stump and 0.44 ± 0.02 in distal stump), Cx45 showed higher levels (0.68 ± 0.01 in proximal stump and 0.9 ± 0.07 in distal stump). In immunogold-EM of optic nerve sections, we found electric synapses (formed mostly by Cx45) directly coupling neighbouring axons. In fVEP, blocking of gap junctions with meclofenamic acid resulted in significant prolongation of the latency of P1 wave up to 160% after 30 min (p Peer reviewe

FluoroGold-Labeled Organotypic Retinal Explant Culture for Neurotoxicity Screening Studies

Preclinical toxicity screening of the new retinal compounds is an absolute requirement in the pathway of further drug development. Since retinal neuron cultivation and in vivo studies are relatively expensive and time consuming, we aimed to create a fast and reproducible ex vivo system for retinal toxicity screening. For this purpose, we used rat retinal explant culture that was retrogradely labeled with the FluoroGold before the isolation. Explants were exposed to a toxic concentration of gentamicin and ciliary neurotrophic factor (CNTF), a known neuroprotective agent. The measured outcomes showed the cell density in retinal ganglion cell layer (GCL) and the activity of lactate dehydrogenase (LDH) in the culture medium. Gentamicin-induced oxidative stress resulted in retinal cell damage and rapid LDH release to the culture medium (p<0.05). Additional CNTF supplementation minimized the cell damage, and the increase of LDH release was insignificant when compared to LDH levels before gentamicin insult (p>0.05). As well as this, the LDH activity was directly correlated with the cell count in GCL (R=−0.84, p<0.00001), making a sensitive marker of retinal neuron damage. The FLOREC protocol could be considered as a fast, reproducible, and sensitive method to detect neurotoxicity in the screening studies of the retinal drugs

Predegenerated Schwann cells-a novel prospect for cell therapy for glaucoma : neuroprotection, neuroregeneration and neuroplasticity

Glaucoma is an optic neuropathy that leads to irreversible blindness. Because the current therapies are not sufficient to protect against glaucoma-induced visual impairment, new treatment approaches are necessary to prevent disease progression. Cell transplantation techniques are currently considered to be among the most promising opportunities for nervous system damage treatment. The beneficial effects of undifferentiated cells have been investigated in experimental models of glaucoma, however experiments were accompanied by various barriers, which would make putative treatment difficult or even impossible to apply in a clinical setting. The novel therapy proposed in our study creates conditions to eliminate some of the identified barriers described for precursor cells transplantation and allows us to observe direct neuroprotective and pro-regenerative effects in ongoing optic neuropathy without additional modifications to the transplanted cells. We demonstrated that the proposed novel Schwann cell therapy might be promising, effective and easy to apply, and is safer than the alternative cell therapies for the treatment of glaucoma.Peer reviewe