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41.
Leonardo Martinez Gisela Collazo Lilia Cabrera Antonio Bernabe-Ortiz Yasnina Ramos-Pe?a Richard Oberhelman 《The American journal of tropical medicine and hygiene》2013,89(2):229-231
Free-ranging chickens are often found in periurban communities in developing countries, and their feces can pose a significant public health sanitation problem. Corralling chickens raised in these periurban areas in chicken coops has been proposed previously as an intervention to address this problem. Aims of this study were to revisit households in a corralling intervention study conducted in 2000–2001 to compare poultry-raising practices and investigate current attitudes regarding the impact of raising chickens in a periurban environment. Sociobehavioral questionnaires were given sequentially to all study participants; 30 families (58%) ceased raising poultry of any kind, whereas 42 (81%) do not raise chickens in their home. This finding indicates a significant reduction in poultry-raising in our study population since 2000–2001, possibly because of acculturation and/or change in socioeconomic status. However, attitudes about corral use for raising poultry were overwhelmingly positive, and the most common reason cited was cleanliness of the home. 相似文献
42.
43.
Pereira-Filho J Rörig LR Schettini CA Soppa MA Santana BL dos Santos JE 《Anais da Academia Brasileira de Ciências》2010,82(4):963-982
This study was carried out with the aim of evaluating the spatial variation of the water quality in the Itajaí-A?ú River estuary. Seven stations along the estuary were monitored on a weekly basis, from October 2003 to December 2004, plus two stations in tributaries (Itajaí-Mirim River, the main tributary, and one reference station). This monitoring included measurements of salinity, pH, dissolved oxygen, temperature, nutrients(NH+4,NO3-2,NO-3,PO3-4,H4SiO4) Biochemical Oxygen Demand (BOD), total phosphorous and dissolved organic phosphorus (TP and DOP), particulate organic carbon (POC), suspended particulate matter (SPM) and chlorophyll-a (Cla). Multivariate analyses demonstrated the compartmentalization of the system based on the deterioration in water quality and marine influence. Urban development was the main factor responsible for the spatial variation of the monitored variables, resulting in increases in the indicators for organic matter and a progressive decrease in O2. Despite the effect of dilution by marine influence, there was an increase in ammonium, attributed to the influence of the municipal districts of Itajaí and Navegantes, close to the river mouth. 相似文献
44.
45.
Lubart R Friedmann H Lavie R Longo L Jacobi J Baruchin O Baruchin AM 《Lasers in medical science》2007,22(1):1-3
In recent years, much research has been done in the field of non-ablative skin rejuvenation. This comes as a response to the
continuous demand for a simple method of treating rhytides, UV exposure, and acne scars. Numerous researches involve visible
light-pulsed systems (20–30 J/cm2). The mechanism of action is believed to be a selective heat-induced denaturalization of dermal collagen that leads to subsequent
reactive synthesis (Bitter Jr., Dermatol. Surg., 26:836–843, 2000; Fitzpatrick et al., Arch. Dermatol., 132:395–402, 1996; Kauvar and Geronemus, Dermatol. Clin., 15:459–467, 1997; Negishi et al., Lasers Surg. Med., 30:298–305, 2002; Goldberg and Cutler, Lasers Surg. Med., 26:196–200, 2000; Hernandez-Perez and Ibeitt, Dermatol. Surg., 28:651–655, 2002). In this study, we suggest a different mechanism for photorejuvenation based on light-induced reactive oxygen species (ROS)
formation. We irradiated collagen in vitro with a broadband of visible light (400–800 nm, 24–72 J/cm2) and used the spin trapping coupled with electron paramagnetic resonance spectroscopy to detect ROS. Irradiated collagen
resulted in hydroxyl radicals formation. We propose, as a new concept, that visible light at the energy doses used for skin
rejuvenation (20–30 J/cm2) produces high amounts of ROS, which destroy old collagen fibers, encouraging the formation of new ones. On the other hand,
at inner depths of the skin, where the light intensity is much weaker, low amounts of ROS are formed, which are well known
to stimulate fibroblast proliferation. 相似文献
46.
Gradient dynamical systems with discontinuous righthand sides are designed using Persidskii-type nonsmooth Lyapunov functions to work as support vector machines (SVMs) for the discrimination of nonseparable classes. The gradient systems are obtained from an exact penalty method applied to the constrained quadratic optimization problems, which are formulations of two well known SVMs. Global convergence of the trajectories of the gradient dynamical systems to the solution of the corresponding constrained problems is shown to be independent of the penalty parameters and of the parameters of the SVMs. The proposed gradient systems can be implemented as simple analog circuits as well as using standard software for integration of ODEs, and in order to use efficient integration methods with adaptive stepsize selection, the discontinuous terms are smoothed around a neighborhood of the discontinuity surface by means of the boundary layer technique. The scalability of the proposed gradient systems is also shown by means of an implementation using parallel computers, resulting in smaller processing times when compared with traditional SVM packages. 相似文献
47.
Sanabria ER D'Andrea Vieira I da Silveira Pereira MF Faria LC da Silva AC Cavalheiro EA da Silva Fernandes MJ 《Brain research bulletin》2006,69(5):535-545
Pharmacological induction of epileptiform activity is a complementary method to study the epileptogenic area in drug-resistant epileptic patients. Among the different activation methods, fentanyl derivatives (e.g. alfentanil) provide one of the most efficient tools in triggering epileptiform abnormalities in surgical candidates. In this study, we tested the pro-epileptic effect of different concentrations of alfentanil in hippocampal slices obtained from control and pilocarpine-treated chronic epileptic rats. The pro-convulsant action of alfentanil was also studied in control and pilocarpine-treated epileptic rats implanted with subdural and hippocampal electrodes for electroencephalographic recordings. In 90% of slices from control animals, application of alfentanil (0.1-5 microM) induced a significant enhancement in amplitude and number of population spikes recorded in the hippocampal CA1 region. In contrast, alfentanil produced a significant reduction in the amplitude of population spikes in slices from pilocarpine-treated epileptic rats. These changes were accompanied by a significant increase in the number of population spikes in the form of epileptiform multispike responses of epileptic slices. Naloxone (20 microM) antagonized the effect of alfentanil in both control and epileptic slices, reducing the number of population spikes in slices from epileptic rats. In control rats, alfentanil induced epileptiform abnormalities in the hippocampal and cortical electroencephalographic recordings but only at concentrations higher than 200 microg/kg (e.g. 350 microg/kg). Lower doses of alfentanil (25 microg/kg) elicited epileptiform abnormalities only in chronic epileptic rats. The potent action of a minimal dose of alfentanil in inducing epileptiform activity suggests an enhancement of the pro-convulsant action of mu-receptor opioids in chronic temporal lobe epilepsy. 相似文献
48.
Stroke is the leading cause of adult disability in the western world. Consensus has built over the last few years regarding the usefulness of training to improve motor disability resulting from stroke. Until recently, there were no accepted strategies to enhance the beneficial effects of training. However, the combination of basic and clinical science data over the last few years is changing this picture, and is highly relevant to the field of neurorehabilitation. Human studies in both healthy individuals and patients after brain damage demonstrate as a proof of principle that somatosensory input, cortical stimulation, interhemispheric interactions, and pharmacologic interventions can modulate cortical plasticity in neurorehabilitation after stroke. These findings strongly suggest directions in the development of novel strategies to enhance training effects on motor recovery. The intent of this review is to describe these strategies, the basic science principles on which they are based, and the clinical applications that have emerged so far. 相似文献
49.
Christian E Jacome‐Galarza Sun‐Kyeong Lee Joseph A Lorenzo Hector Leonardo Aguila 《Journal of bone and mineral research》2011,26(6):1207-1216
Parathyroid hormone (PTH) increases both the number of osteoclast in bone and the number of early hematopoietic stem cells (HSCs) in bone marrow. We previously characterized the phenotype of multiple populations of bone marrow cells with in vitro osteoclastogenic potential in mice. Here we examined whether intermittent administration of PTH influences these osteoclast progenitor (OCP) populations. C57BL/6 mice were treated with daily injections of bPTH(1–34) (80 µg/kg/day) for 7 or 14 days. We found that PTH caused a significant increase in the percentage of TN/CD115+CD117high and TN/CD115+CD117int cells (p < .05) in bone marrow on day 7. In contrast, PTH decreased the absolute number of TN/CD115+CD117low cells by 39% on day 7 (p < .05). On day 14, there was no effect of PTH on osteoclast progenitor distribution in vivo. However, PTH treatment for 7 and 14 days did increase receptor activator of NF‐κB ligand (RANKL)– and macrophage colony‐stimulating factor (M‐CSF)–stimulated in vitro osteoclastogenesis and bone resorption in TN/CD115+ cells. In the periphery, 14 days of treatment increased the percentage and absolute numbers of HSCs (Lin?CD117+Sca‐1+) in the spleen (p < .05). These data correlated with an increase in the percent and absolute numbers of HSCs in bone marrow on day 14 (p < .05). Interestingly, the effects on hematopoietic progenitors do not depend on osteoclast resorption activity. These results suggest that in vivo PTH treatment increased in vitro osteoclastogenesis and resorption without altering the number of osteoclast precursors. This implies that in vivo PTH induces sustained changes, possibly through an epigenetic mechanism, in the in vitro responsiveness of the cells to M‐CSF and RANKL. © 2011 American Society for Bone and Mineral Research. 相似文献
50.
Leonardo CR Filgueiras MF Vasconcelos MM Vasconcelos R Marino VP Pires C Pereira AC Reis F Oliveira EA Lima EM 《Pediatric nephrology (Berlin, Germany)》2007,22(11):1891-1896
Risk factors for renal scarring in children with lower urinary tract dysfunction (LUTD) were evaluated. The medical records
of 120 patients were assessed concerning gender, presence of vesicoureteric reflux (VUR), bladder capacity, detrusor overactivity,
residual urine, febrile urinary tract infection (UTI), bacteriuria, constipation, detrusor sphincter incoordination (DSI),
high detrusor pressure at maximal cystometric capacity (PMCC), low compliance, and thickness and trabeculation of the bladder
wall. Renal scarring was diagnosed by 99mtechnetium-dimercaptosuccinic acid renal scan (DMSA). Renal scarring was detected in 38 patients (31%). VUR, UTI, decreased
bladder capacity, urinary residue, and trabeculated and thick bladder wall were associated with scarring at univariate analysis.
Multivariate analysis showed VUR (P < 0.0001) as the independent risk factor for renal scarring. Thickness of the bladder wall was a marginal risk factor (P
= 0.07). Although UTI was not a risk factor, it was associated with VUR (P
= 0.03). In our analysis, VUR was the main risk factor; however, renal scarring was probably due to multifactorial causes,
as VUR was associated with UTI. 相似文献