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BACKGROUND: Ewe mortality during pregnancy and lambing is an issue for sheep producers globally, resulting in reduced productivity and profitability, compromised ewe welfare, and poor consumer perception. Despite these negative consequences, there was little investigation into factors associated with ewe death during this time. Therefore, this study aimed to assess associations between ewe body condition score (BCS), weight, reproductive parameters, and risk of mortality during pregnancy and lambing. METHODS: Four cohorts from three commercial New Zealand farms participated, with 13,142 ewe lambs enrolled and followed over time. Data were collected for five consecutive lambings. Visits aligned with key on-farm management times, specifically: prior to breeding, at pregnancy diagnosis (PD), prior to lambing (set-stocking), and, at weaning of their lambs. At each visit, ewes were weighed, BCS assessed and reproductive status was recorded when relevant (litter size at PD and lactation status after lambing). Ewes that died or were culled were recorded, and any ewes that were absent from consecutive visits were presumed dead. Logistic regressions were developed to assess the relationship between weight and BCS at each visit, PD result (single or multiple-bearing) and lactation status (wet or dry) in each year, and, risk of mortality during the pregnancy and lambing period in each year. RESULTS: In the PD to weaning period, mortality incidence ranged from 6.3 to 6.9% for two-tooth (18-months-old at breeding) to mixed-age (54-months-old at breeding) ewes. For ewe lambs (7 to 8-months-old at breeding), mortality was 7.3% from set-stocking to weaning. Heavier ewe lambs at PD were less likely to die during lambing (OR: 0.978, p = 0.013), as were those with greater set-stocking BCS. In subsequent years, BCS was a predictor of ewe death, with odds of mortality greatest for ewes < BCS 2.5. Additionally, for poorer BCS ewes, increasing weight reduced risk of mortality, but there was no impact of increasing weight in greater BCS ewes. CONCLUSIONS: This study identified risk factors associated with ewe mortality during the pregnancy and lambing period. Flock owners can use these to either cull at-risk ewes or proactively intervene to reduce likelihood of mortality, thereby improving flock productivity, profitability and welfare.
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Resultado da Gravidez , Aumento de Peso , Gravidez , Animais , Ovinos , Feminino , Tamanho da Ninhada de Vivíparos , Fatores de Risco , Nova Zelândia/epidemiologiaRESUMO
Genetic and pharmacological studies have defined a role for the melanocortin-4 receptor (Mc4r) in the regulation of energy homeostasis. The physiological function of Mc3r, a melanocortin receptor expressed at high levels in the hypothalamus, has remained unknown. We evaluated the potential role of Mc3r in energy homeostasis by studying Mc3r-deficient (Mc3r(-/-)) mice and compared the functions of Mc3r and Mc4r in mice deficient for both genes. The 4-6-month Mc3r-/- mice have increased fat mass, reduced lean mass and higher feed efficiency than wild-type littermates, despite being hypophagic and maintaining normal metabolic rates. (Feed efficiency is the ratio of weight gain to food intake.) Consistent with increased fat mass, Mc3r(-/-) mice are hyperleptinaemic and male Mc3r(-/-) mice develop mild hyperinsulinaemia. Mc3r(-/-) mice did not have significantly altered corticosterone or total thyroxine (T4) levels. Mice lacking both Mc3r and Mc4r become significantly heavier than Mc4r(-/-) mice. We conclude that Mc3r and Mc4r serve non-redundant roles in the regulation of energy homeostasis.
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Tecido Adiposo/metabolismo , Peso Corporal , Receptores da Corticotropina/genética , Receptores da Corticotropina/fisiologia , Fatores Etários , Animais , Southern Blotting , Temperatura Corporal , Calorimetria , Corticosterona/biossíntese , Comportamento Alimentar , Feminino , Genótipo , Glucose/biossíntese , Humanos , Hiperinsulinismo/genética , Hibridização In Situ , Insulina/biossíntese , Leptina/biossíntese , Masculino , Camundongos , Camundongos Knockout , Modelos Genéticos , Atividade Motora , Obesidade/genética , Oligopeptídeos/farmacologia , Fenótipo , Isoformas de Proteínas , Receptor Tipo 3 de Melanocortina , Receptor Tipo 4 de Melanocortina , Receptores da Corticotropina/química , Receptores de Peptídeos/genética , Receptores de Peptídeos/metabolismo , Recombinação Genética , Tiroxina/biossíntese , Fatores de Tempo , Distribuição Tecidual , alfa-MSH/análogos & derivadosRESUMO
Recently increased flood events have been prompting researchers to improve existing coupled flood-models such as one-dimensional (1D)/1D and 1D/two-dimensional (2D) models. While 1D/1D models simulate sewer and surface networks using a one-dimensional approach, 1D/2D models represent the surface network by a two-dimensional surface grid. However their application raises two issues to urban flood modellers: (1) stormwater systems planning/emergency or risk analysis demands for fast models, and the 1D/2D computational time is prohibitive, (2) and the recognized lack of field data (e.g. Hunter et al. (2008)) causes difficulties for the calibration/validation of 1D/1D models. In this paper we propose to overcome these issues by calibrating a 1D/1D model with the results of a 1D/2D model. The flood-inundation results show that: (1) 1D/2D results can be used to calibrate faster 1D/1D models, (2) the 1D/1D model is able to map the 1D/2D flood maximum extent well, and the flooding limits satisfactorily in each time-step, (3) the 1D/1D model major differences are the instantaneous flow propagation and overestimation of the flood-depths within surface-ponds, (4) the agreement in the volume surcharged by both models is a necessary condition for the 1D surface-network validation and (5) the agreement of the manholes discharge shapes measures the fitness of the calibrated 1D surface-network.
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Inundações , Modelos Teóricos , Algoritmos , CalibragemRESUMO
Intense rainfall in urban areas often generates both pluvial flooding due to the limited capacity of drainage systems, as well as fluvial flooding caused by deluges from river channels. The concurrence of pluvial and fluvial flooding can aggravate their (individual) potential damages. To analyse the impact caused by individual and composite type of flooding, the SIPSON/UIM model, an integrated 1D sewer and 2D overland flow was applied to numerical modelling. An event matrix of possible pluvial scenarios was combined with hypothetic overtopping and breaching situations to estimate the surface flooding consequences in the Stockbridge area, Keighley (Bradford, UK). The modelling results identified different flooding drivers in different parts of the study area and showed that the worst scenarios resulted from synthesised events.
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Drenagem Sanitária , Inundações , Modelos Estatísticos , Reino UnidoRESUMO
The design, construction and maintenance of Critical Infrastructures (CI) is commonly based on standards that are rigorous, so as to withstand any climate or weather-linked pressures. However, due to climate change, climate characteristics may shift, resulting in increased frequency/magnitude of potential failures, or exposure to new unknown risks. As vital components for the normal functioning of modern societies, the resilience of CIs under climate stressors encompasses their structural integrity, their operational elements, and their capacity to maximize business output. In this work, we propose an integrated and participatory methodological approach to enhance the resilience of interconnected CIs to urban flooding under climate change, by assessing the risk and introducing adaptation measures. The main objectives of the proposed methodology and approach are: (i) to provide scientific evidence for better understanding of how future climate regimes might affect normal operation of interconnected CI in urban areas during their lifespan; (ii) to assess the cost-effectiveness of different adaptation measures; (iii) to involve local stakeholders and operators in the co-design of the approach, as well as the assessment and the evaluation of adaptation measures; (iv) to combine computational modelling with advanced 3D visualisation techniques for effectively engaging stakeholders in decision making; (v) to include risk assessment and damage functions co-designed by end-users and local stakeholders; (vi) to integrate all of the aforementioned components in a specifically designed cloud platform as a Decision Support System for end-users, (vii) to validate the DSS by the end users and local stakeholders. The paper presents the computational background and tools. Additionally, it describes a Case Study in Torbay, UK, where the full methodology and the proposed participatory approach have been applied, with all the specifics, i.e., the scenarios of extreme flooding, the numerical and visualisation results, the response of the stakeholders and the evaluation of selected adaptation measures.
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PURPOSE: OP-lysine, a glycation product of lysine residues of proteins, has been reported to be formed with glyceraldehyde and glycolaldehyde as precursors in the lens, and has been suggested to play a role in senile cataracts. However, there has been no reliable information regarding the content of glyceraldehyde in tissues. This study determined the glyceraldehyde levels in the lenses of normal and diabetic rats. METHODS: Glyceraldehyde was derivatized to a fluorescent compound, and the compound was then quantified by high-performance liquid chromatography. RESULTS: The lens glyceraldehyde levels in normal and diabetic rats were 0.75 +/- 0.06 and 1.26 +/- 0.21 nmol/g wet weight (means +/- standard deviations of 6 animals, p < 0.01), respectively. Isolated rat lenses accumulated a higher level of glyceraldehyde when cultured for 6 days in 25.5 mM glucose than when cultured in 5.5 mM glucose. CONCLUSIONS: Glyceraldehyde was found to be present in the lens and was increased in diabetes mellitus. OP-lysine is thus likely to be a potential risk factor for senile and diabetic cataracts.
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Catarata/metabolismo , Diabetes Mellitus Tipo 2/metabolismo , Gliceraldeído/metabolismo , Cristalino/metabolismo , Aldeído Redutase/antagonistas & inibidores , Animais , Benzofuranos/farmacologia , Glicemia/análise , Cromatografia Líquida de Alta Pressão , Modelos Animais de Doenças , Hidantoínas/farmacologia , Cristalino/efeitos dos fármacos , Lisina/análogos & derivados , Lisina/metabolismo , Masculino , Compostos de Piridínio/metabolismo , Ratos , Ratos WistarRESUMO
Through analysis of rat genomic cosmid clones, the 5'-most exon of the rat neural cell adhesion molecule (NCAM) gene was identified. This exon, here named exon 0, contained the entire 5' untranslated region and the N-terminal signal sequence of the polypeptide. Exon 0 was isolated from a 1.6-kilobase (kb) EcoRI-HindIII fragment of rat genomic cosmid clone 9 which was 35 kb in length. This fragment was sequenced and found to contain approximately 940 base pairs (bp) of 5'-flanking sequence, exon 0, which was approximately 245 bp in length, and approximately 400 bp of the following intron 0. By using information derived from this fragment and the pR18 rat NCAM cDNA, the transcription initiation sites were determined with two assays. Both primer extensions and nuclease S1 protection assays of postnatal day 7 rat brain RNA identified seven initiation sites within a single 10-bp region at positions -195 to -186 relative to the translation start site. An additional minor site was found at position -329. In the immediate 5' region, no consensus TATA or CCAAT sequences were found. Potential regulatory elements within this region include Sp1 consensus binding sites and also a 178-bp homopurine-homopyrimidine sequence containing several mirror repeats. NCAM has multiple transcripts which are regulated in a developmental and tissue-specific fashion. To determine whether these transcripts are initiated at the same sites, transcription initiation sites were analyzed in postnatal day 7 and adult rat brain and also in cultured cell lines of neuronal, glial, and muscle phenotypes. These tissues and cells exhibited distinct NCAM transcript populations in Northern (RNA) dot blot analysis. In all cases similar transcription start sites were found, suggesting that all major NCAM transcripts have similar or identical initiation sites. These results provide essential information to begin analysis of NCAM regulation in different tissues and during development.
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Moléculas de Adesão Celular Neuronais/genética , Genes , Transcrição Gênica , Envelhecimento , Sequência de Aminoácidos , Animais , Sequência de Bases , Linhagem Celular , Clonagem Molecular , Cosmídeos , Regulação da Expressão Gênica , Biblioteca Gênica , Dados de Sequência Molecular , Especificidade de Órgãos , Plasmídeos , RNA/genética , RNA Mensageiro/genética , Ratos , Mapeamento por RestriçãoRESUMO
A numerical model is developed in this study with various components for simulating the complex flow phenomena in urban drainage basins. The model integrates the HEC-1 model, a 1-D dynamic channel-flow model, a 2-D non-inertia overland-flow model and the SWMM model to reflect the hydraulic processes in areas with different characteristics. The inundation of underground infrastructure during flood is also considered in the model. The typhoon Nari event in 2001, which resulted in severe flood in downtown Taipei, is simulated by the model. The result is compared with the survey records of flooded areas, which reveals the storage effect of underground infrastrucures is significant to the simulation results of highly developed urban areas.
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Modelos Teóricos , Eliminação de Resíduos Líquidos , Cidades , Desastres , Chuva , Taiwan , Movimentos da ÁguaRESUMO
We present a solution for detecting dementia-related travel patterns using only inertial sensors. The results and lessons learnt from the experiments on dementia and non-dementia subjects are reported.
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Demência/etiologia , Monitorização Ambulatorial/métodos , Comportamento Errante , Adulto , Algoritmos , Desenho de Equipamento , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Monitorização Ambulatorial/instrumentaçãoRESUMO
Ghrelin, a stomach-derived orexigenic hormone, has stimulated great interest as a potential target for obesity control. Pharmacological evidence indicates that ghrelin's effects on food intake are mediated by neuropeptide Y (NPY) and agouti-related protein (AgRP) in the central nervous system. These include intracerebroventricular application of antibodies to neutralize NPY and AgRP, and the application of an NPY Y1 receptor antagonist, which blocks some of the orexigenic effects of ghrelin. Here we describe treatment of Agrp(-/-);Npy(-/-) and Mc3r(-/-);Mc4r(-/-) double knockout mice as well as Npy(-/-) and Agrp(-/-) single knockout mice with either ghrelin or an orally active nonpeptide ghrelin agonist. The data demonstrate that NPY and AgRP are required for the orexigenic effects of ghrelin, as well as the involvement of the melanocortin pathway in ghrelin signaling. Our results outline a functional interaction between the NPY and AgRP pathways. Although deletion of either NPY or AgRP caused only a modest or nondetectable effect, ablation of both ligands completely abolished the orexigenic action of ghrelin. Our results establish an in vivo orexigenic function for NPY and AgRP, mediating the effect of ghrelin.
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Apetite/fisiologia , Neuropeptídeo Y/fisiologia , Hormônios Peptídicos/fisiologia , Proteínas/fisiologia , Proteína Relacionada com Agouti , Animais , Apetite/efeitos dos fármacos , Grelina , Peptídeos e Proteínas de Sinalização Intercelular , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Hormônios Peptídicos/farmacologia , Receptor Tipo 3 de Melanocortina/fisiologia , Receptor Tipo 4 de Melanocortina/fisiologia , Receptores Acoplados a Proteínas G/fisiologia , Receptores de GrelinaRESUMO
PURPOSE: To evaluate the dose calculation algorithm used in the inverse treatment planning computer system for the intensity modulation multileaf collimator. METHODS AND MATERIALS: The inverse treatment-planning computer system calculates the intensities of multiple pencil beams to achieve an optimal distribution and modulates the beam intensity through the special multileaf collimator. The system's dose calculation algorithm made the two basic assumptions: (a) The tissue-maximum ratios (TMRs) of a single pencil beam have the same values as TMRs for raylines through each pencil beam that are determined from percentage depth dose isodose curves along the long axis of the 2 x 20 cm2 field with all leaves open; and (b) the relative output factors (ROF) of each pencil beam also have the same values as the rayline TMR at d(max) of the 2 x 20 cm2 field. To verify these two assumptions, a special multileaf collimator was installed to our linear accelerator which produces 4 MV x-rays. The TMRs and ROFs for the single leaves 1 through 10 were measured using an ion chamber and TLD dosimeter in either a water or a polystyrene phantom. The values of rayline TMRs were calculated from the measured crossplane isodose curves of the 2 x 20 cm2 field. Comparisons were made between these two sets of data. RESULTS: Based on our measurements, we found that the ROFs of a pencil beam obtained from the rayline TMRs at d(max) are as much as 7.6% greater than that of single pencil beams. The ROF of the 1 x 1 cm2 pencil beam is 4 and 6.5% less than that of a cluster of four neighboring pencil beams forming a 2 x 2 cm2, and a 2 x 20 cm2 field respectively. However, the rayline TMRs are generally larger than the TMRs of a single pencil beam. At a depth of 8 cm, the average depth in the middle of intracranial space, the rayline TMRs of the pencil beams of leaves 1 and 10 are 5.4 and 9% higher than a single pencil beam TMR at the same depth, respectively. Also interesting is to note that the TMRs of each of the single pencil beams were found to be equal. CONCLUSIONS: In our article, evaluations and comparisons of TMRs and ROFs were made for two extreme conditions. The measured values of TMRs and ROFs of a single beam have been shown to be significantly different from those used in the calculations. Because both the TMR and ROF are influenced by the scattering radiation in the same direction, the deviations for these two factors would be expected to be magnified. Thus, for the two extreme situations we have investigated, dose deviations would be on the order of 15%. In real patient treatment; of course, these deviations may be somewhat less, but still significant. Our results, however, show that further investigations are warranted.
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Dosagem Radioterapêutica , Algoritmos , HumanosRESUMO
PURPOSE: The roles of postoperative pelvic and prophylactic paraaortic irradiation in pelvic node positive cervical cancer are currently controversial. A retrospective study was undertaken to examine the effect of pelvic irradiation on pelvic control and survival and to analyze the patterns of recurrence to determine whether indications exist for prophylactic paraaortic irradiation. METHODS AND MATERIALS: From 1964 to 1991, 143 cases of FIGO Stage I and II cervical cancer undergoing exploratory laparotomy, pelvic lymph node dissection, and radical hysterectomy had positive pelvic lymph nodes. Postoperatively, 108 cases were treated with whole pelvic irradiation while 35 patients were observed. Prophylactic paraaortic irradiation was not given. RESULTS: Patients who received postoperative whole pelvic irradiation compared with those treated with radical hysterectomy alone had a significantly improved pelvic control rate, disease-free survival (DFS), and overall survival. The 5-year actuarial pelvic control rate was 78% vs. 45% (p = < 0.0001), respectively. The 5-year actuarial DFS was 65% vs. 41% (p = 0.0004). The 5-year actuarial overall survival was 58% vs. 46% (p = 0.02). In multivariate analysis, pelvic irradiation continued to show a positive effect on DFS (p = 0.0001) and overall survival (p = 0.0035). Lymphatic invasion and the total number of positive lymph nodes were the only other independent predictors of overall survival and DFS. The actuarial 5-year pelvic, paraaortic, and distant failure rates were 30%, 10%, and 28%, respectively. An isolated first recurrence in the paraaortic nodes occurred in only three cases. CONCLUSION: Postoperative pelvic irradiation significantly improves pelvic control, DFS, and overall survival, and should be used in patients with early stage cervical cancer and pathologically proven pelvic nodal metastases. The low incidence of isolated paraaortic nodal failure calls into question the value of routine prophylactic paraaortic irradiation in these patients.
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Neoplasias do Colo do Útero/radioterapia , Adulto , Idoso , Feminino , Humanos , Metástase Linfática , Pessoa de Meia-Idade , Pelve , Prognóstico , Recidiva , Estudos Retrospectivos , Fatores de Risco , Análise de Sobrevida , Neoplasias do Colo do Útero/patologia , Neoplasias do Colo do Útero/cirurgiaRESUMO
PURPOSE: The intraoperative planning with peripheral loading approach is an important technique for ultrasound-guided transperineal prostate implant. In this paper a sphero-cylindrical dose model is described to generate a new power law or a look-up table for determination of the total (125)I activity required to deliver a prescription dose to a given prostate volume. METHODS AND MATERIALS: Dose calculations were based on the new standards for (125)I seeds (model 6711) implemented by the National Institute of Standards and Technology (NIST) in 1999. Using the sphero-cylindrical dose model with peripheral loading approach, a new power law for calculating total activity of radioactive iodine required to deliver a prescribed dose for the target volume was developed. Accounting for random variation of the seed positioning in the prostate and the current air-kerma strength standard of (125)I seeds, this new power law is formulated as follows: A (mCi) = 2.15 d (cm)(2.00) where A is apparent activity in mCi, or A (U) = 1. 69 d (cm)(2.00) where A is air-kerma strength in U, required to deliver a cumulative dose of 145 Gy to a prostate gland with an average dimension, d, in centimeters. RESULTS: The efficacy of using the new power law in prostate implants was demonstrated. For clinical evaluations of this new power law, 40 patients were chosen in 1998. The average D(90) of these 40 patients was 172.0 Gy (SD +/- 29 Gy). This means that on the average, 90% of the target volume received was 172.0 Gy. The average coverage index (CI) in this study was 94.7 (SD +/- 4.7). As a result, 94.7% of the target volume received the prescription dose. The dose homogeneity index (HI) which measured the degree of the dose inhomogeneity was 0.38 (SD +/- 0.21). CONCLUSION: This new and simple power law or a new mCi-volume look-up table for (125)I seed prostate implantation has been developed and formulated for clinical use. Clinical evaluations expressed in quantitative parameters such as D(90), CI, and HI in prostate implants have been thoroughly analyzed and clearly demonstrated the efficacy of this approach.
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Braquiterapia/métodos , Radioisótopos do Iodo/uso terapêutico , Neoplasias da Próstata/radioterapia , Ultrassonografia de Intervenção , Humanos , Masculino , Modelos Teóricos , Fenômenos Físicos , Física , Neoplasias da Próstata/patologia , Dosagem Radioterapêutica , Valores de ReferênciaRESUMO
PURPOSE: To examine the clinical and genetic heterogeneity of autosomal dominant optic atrophy among two unrelated central Illinois families. METHODS: Forty-three individuals from two pedigrees had complete eye examinations. Linkage analysis was performed with microsatellite markers from the region 3q28-29. RESULTS: Visual acuity in 21 affected individuals ranged from 20/25 to 20/800. Vision loss was more severe in males than females (P = 0.02). Color vision testing revealed generalized dyschromatopsia. Both visual acuity and color vision deteriorated with age. Linkage was established to chromosome 3q28-29 (LODmax = 4.68 for D3S2305). CONCLUSION: Autosomal dominant optic atrophy linked to chromosome 3q28-29 shows intrafamilial phenotypic variation as well as sex-influenced severity in two Midwestern families.
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Cromossomos Humanos Par 3/genética , Escore Lod , Repetições de Microssatélites/genética , Atrofia Óptica Autossômica Dominante/genética , Adolescente , Adulto , Fatores Etários , Idoso , Criança , Pré-Escolar , Família , Feminino , Humanos , Illinois , Lactente , Masculino , Pessoa de Meia-Idade , Linhagem , Fatores SexuaisRESUMO
Granular activated carbon (GAC), in the presence of dilute aqueous hypochlorite solutions typical of those used in water treatment, was converted to a reagent capable of carrying out free-radical coupling reactions and other oxidations of dilute aqueous solutions of phenols. The products included biphenyls with chlorine and hydroxyl substitution (hydroxylated polychlorinated biphenyls). For example, 2,4-dichlorophenol, a common constituent of wastewaters and also natural waters treated with hypochlorite, was converted to 3,5,5'trichloro-2,4'-dihydroxybiphenyl and several related compounds in significant amounts. It is possible that these products pose more of a health hazard than either the starting phenols or the unhydroxylated polychlorinated biphenyl derivatives.
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Carbono , Ácido Hipocloroso , Bifenilos Policlorados , Abastecimento de Água/análise , Desinfetantes , Radicais Livres , Hidroxilação , OxirreduçãoRESUMO
Poly(acrylic acid-co-methyl methacrylate)-cetyltrimethylammonium bromide (P(AA-co-MMA)-C16TAB) complex has shape memory behavior due to the formation of crystalline aggregates among the long alkyl chains of C16TAB in the complex, and can be regarded as a novel shape memory network.
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Since the advantages of using ureteral stents in conjunction with extracorporeal shock wave lithotripsy were first recognized, the growing demand for outpatient stone treatment has made stent use much more frequent. However, prophylactic stent placement must be judicious to maximize success and minimize associated morbidity. Recent controlled retrospective studies and randomized trials showed that ureteral stenting does not increase the stone-free rate or reduce the complication rate for stones less than 2 cm in size, yet in such cases, there are increased morbidities such as urinary urgency, frequency, stent migration, and encrustation. However, in patients with stones larger than 2 cm, Type C4 staghorn calculi, or stones associated with a solitary kidney, prophylactic stent placement may reduce the complication rates arising from these larger stone burdens. Finally, ureteral stenting may be helpful for stone localization or manipulation.
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Litotripsia , Stents , Ureter , Desenho de Equipamento , Humanos , Stents/efeitos adversosRESUMO
In traditional brachytherapy for carcinoma of the cervix, doses are often prescribed to specifically chosen points (A and B) and the normal tissue tolerance calculated at specific reference points in the bladder and rectum. These tolerance doses are often used to modify the brachytherapy treatment plan. It is inherently assumed that the position of the brachytherapy applicator does not change in relation to the relevant anatomical structures over the time-course of an implant. To assess the accuracy of this assumption, 2 sets of localization films were obtained for each implant in 28 patients, 1 prior to loading and another after the removal of the radioactive sources. Significant applicator movement and, consequently, significant dose variations were ob: served. Therefore, isolated one-time dose measurements to normal critical structures should not be used as the sole basis for making therapeutic decisions. The magnitude of dose variations and their clinical significant are discussed.
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Braquiterapia , Dosagem Radioterapêutica , Neoplasias do Colo do Útero/radioterapia , Feminino , HumanosRESUMO
Diabetic retinopathy (DR), an ocular complication of diabetes mellitus, is the leading cause of blindness in Americans age 20 to 74 today. The more severe stage of the disease, proliferative diabetic retinopathy, affects an estimated 700,000 Americans. Based on clinical findings, the disease is generally classified as nonproliferative DR or proliferative DR. While the former often begins as a symptomatically silent disease, it nevertheless may be progressing to itself cause significant visual loss. Based principally on evidence from several studies sponsored by the National Eye Institute, current treatment consists of regular observation by an ophthalmologist, laser photocoagulation, and vitrectomy. In addition, preventive methods such as tight glycemic control and ophthalmic screening of diabetics appear beneficial. While the ophthalmologist can provide specialized services for the DR patient, prevention and control lie largely in the hands of the primary care physician. Thus, only when primary and specialized care have established a strong partnership can they save the sight of the thousands at risk for diabetic retinopathy.