32 resultados para Design For Manufacturing and Assembly
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OBJECTIVES: To document and compare the prevalence of asynchrony events during invasive-assisted mechanical ventilation in pressure support mode and in neurally adjusted ventilatory assist in children. DESIGN: Prospective, randomized, and crossover study. SETTING: Pediatric and Neonatal Intensive Care Unit, University Hospital of Geneva, Switzerland. PATIENTS: Intubated and mechanically ventilated children, between 4 weeks and 5 years old. INTERVENTIONS: Two consecutive ventilation periods (pressure support and neurally adjusted ventilatory assist) were applied in random order. During pressure support, three levels of expiratory trigger setting were compared: expiratory trigger setting as set by the clinician in charge (PSinit), followed by a 10% (in absolute values) increase and decrease of the clinician's expiratory trigger setting. The pressure support session with the least number of asynchrony events was defined as PSbest. Therefore, three periods were compared: PSinit, PSbest, and neurally adjusted ventilatory assist. Asynchrony events, trigger delay, and inspiratory time in excess were quantified for each of them. MEASUREMENTS AND MAIN RESULTS: Data from 19 children were analyzed. Main asynchrony events during PSinit were autotriggering (3.6 events/min [0.7-8.2]), ineffective efforts (1.2/min [0.6-5]), and premature cycling (3.5/min [1.3-4.9]). Their number was significantly reduced with PSbest: autotriggering 1.6/min (0.2-4.9), ineffective efforts 0.7/min (0-2.6), and premature cycling 2/min (0.1-3.1), p < 0.005 for each comparison. The median asynchrony index (total number of asynchronies/triggered and not triggered breaths ×100) was significantly different between PSinit and PSbest: 37.3% [19-47%] and 29% [24-43%], respectively, p < 0.005). With neurally adjusted ventilatory assist, all types of asynchrony events except double-triggering and inspiratory time in excess were significantly reduced resulting in an asynchrony index of 3.8% (2.4-15%) (p < 0.005 compared to PSbest). CONCLUSIONS: Asynchrony events are frequent during pressure support in children despite adjusting the cycling off criteria. Neurally adjusted ventilatory assist allowed for an almost ten-fold reduction in asynchrony events. Further studies should determine the clinical impact of these findings.
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OBJECTIVE: To highlight the clinical presentation, investigation and treatment of haemorrhage into the pancreatic duct. DESIGN: Retrospective study and review of publications. SETTING: University hospital, Switzerland. SUBJECTS: All 4 cases from 1972 to 1993. INTERVENTIONS: 2 Whipple procedures, 1 resection of the pancreatic head, 1 exploratory laparotomy. Radiological embolisation in one case. MAIN OUTCOME MEASURES: Cessation of haemorrhage and survival. RESULTS: The diagnosis was made preoperatively in three cases by gastroduodenoscopy and arteriography. Operation was the primary treatment in all patients and was effective with low morbidity and no mortality in three of them. Embolisation stopped the haemorrhage in the fourth patient, who was alcoholic and died of progressive liver insufficiency and variceal haemorrhage. CONCLUSIONS: There is no specific indication for haemorrhage into the pancreatic duct. The diagnosis is suggested by endoscopy (absence of a more common cause, or blood in the second part of the duodenum). Arteriography is essential to confirm the site of the bleeding and to attempt embolization. Operation is usually the definitive treatment.
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Pneumocystis jirovecii is a fungus belonging to a basal lineage of the Ascomycotina, the Taphrinomycotina subphylum. It is a parasite specific to humans that dwells primarily in the lung and can cause severe pneumonia in individuals with debilitated immune system. Despite its clinical importance, many aspects of its biology remain poorly understood, at least in part because of the lack of a continuous in vitro cultivation system. The present thesis consists in the genome reconstruction and comparative genomics of P. jirovecii. It is made of three parts: (i) the de novo sequencing of P. jirovecii genome starting from a single broncho- alveolar lavage fluid of a single patient (ii) the de novo sequencing of the genome of the plant pathogen Taphrina deformans, a fungus closely related to P. jirovecii, and (iii) the genome scale comparison of P. jirovecii to other Taphrinomycotina members. Enrichment in P. jirovecii cells by immuno-precipitation, whole DNA random amplification, two complementary high throughput DNA sequencing methods, and in silico sorting and assembly of sequences were used for the de novo reconstruction of P. jirovecii genome from the microbiota of a single clinical specimen. An iterative ad hoc pipeline as well as numerical simulations was used to recover P. jirovecii sequences while purging out contaminants and assembly or amplification chimeras. This strategy produced a 8.1 Mb assembly, which encodes 3,898 genes. Homology searches, mapping on biochemical pathways atlases, and manual validations revealed that this genome lacks (i) most of the enzymes dedicated to the amino acids biosyntheses, and (ii) most virulence factors observed in other fungi, e.g. the glyoxylate shunt pathway and specific peptidases involved in the degradation of the host cell membrane. The same analyses applied to the available genomic sequences from Pneumocystis carinii the species infecting rats and Pneumocystis murina the species infecting mice revealed the same deficiencies. The genome sequencing of T. deformans yielded a 13 Mb assembly, which encodes 5,735 genes. T. deformans possesses enzymes involved plant cell wall degradation, secondary metabolism, the glyoxylate cycle, detoxification, sterol biosynthesis, as well as the biosyntheses of plant hormones such as abscisic acid or indole-3-acetic acid. T. deformans also harbors gene subsets that have counterparts in plant saprophytes or pathogens, which is consistent with its alternate saprophytic and pathogenic lifestyles. Mating genes were also identified. The homothallism of this fungus suggests a mating-type switching mechanism. Comparative analyses indicated that 81% of P. jirovecii genes are shared with eight other Taphrinomycotina members, including T. deformans, P. carinii and P. murina. These genes are mostly involved in housekeeping activities. The genes specific to the Pneumocystis genus represent 8%, and are involved in RNA metabolism and signaling. The signaling is known to be crucial for interaction of Pneumocystis spp with their environment. Eleven percent are unique to P. jirovecii and encode mostly proteins of unknown function. These genes in conjunction with other ones (e.g. the major surface glycoproteins) might govern the interaction of P. jirovecii with its human host cells, and potentially be responsible of the host specificity. P. jirovecii exhibits a reduced genome in size with a low GC content, and most probably scavenges vital compounds such as amino acids and cholesterol from human lungs. Consistently, its genome encodes a large set of transporters (ca. 22% of its genes), which may play a pivotal role in the acquisition of these compounds. All these features are generally observed in obligate parasite of various kingdoms (bacteria, protozoa, fungi). Moreover, epidemiological studies failed to evidence a free-living form of the fungus and Pneumocystis spp were shown to co-evolved with their hosts. Given also the lack of virulence factors, our observations strongly suggest that P. jirovecii is an obligate parasite specialized in the colonization of human lungs, and which causes disease only in individuals with compromised immune system. The same conclusion is most likely true for all other Pneumocystis spp in their respective mammalian host. - Pneumocystis jirovecii est un champignon appartenant à ine branche basale des Ascomycotina, le sous-embranchement des Taphrinomycotina. C'est un parasite spécifique aux humains qui réside principalement dans les poumons, et qui peut causer des pneumonies sévères chez des individus ayant un système immunitaire déficient. En dépit de son importance clinique, de nombreux aspects de sa biologie demeurent,largement méconnus, au moins en partie à cause de l'absence d'un système de culture in vitro continu. Cette thèse traite de la reconstruction du génome et de la génomique comparative de P. jirovecii. Elle comporte trois parties: (i) le séquençage de novo du génome de P. jirovecii à partir d'un lavage broncho-alvéolaire provenant d'un seul patient, (ii) le séquençage de novo du génome d'un champignon pathogène de plante Taphrina deformans qui est phylogénétiquement proche de P. jirovecii, et (iii) la comparaison du génome de P. jirovecii à celui d'autres membres du sous-embranchement des Taphrinomycotina. Un enrichissement en cellules de P. jirovecii par immuno-précipitation, une amplification aléatoire des molécules d'ADN, deux méthodes complémentaires de séquençage à haut débit, un tri in silico et un assemblage des séquences ont été utilisés pour reconstruire de novo le génome de P. jirovecii à partir du microbiote d'un seul échantillon clinique. Un pipeline spécifique ainsi que des simulations numériques ont été utilisés pour récupérer les séquences de P. jirovecii tout en éliminant les séquences contaminants et les chimères d'amplification ou d'assemblage. Cette stratégie a produit un assemblage de 8.1 Mb, qui contient 3898 gènes. Les recherches d'homologies, de cartographie des voies métaboliques et des validations manuelles ont révélé que ce génome est dépourvu (i) de la plupart des enzymes dédiées à la biosynthèse des acides aminés, et (ii) de la plupart des facteurs de virulence observés chez d'autres champignons, par exemple, le cycle du glyoxylate ainsi que des peptidases spécifiques impliquées dans la dégradation de la membrane de la cellule hôte. Les analyses appliquées aux données génomiques disponibles de Pneumocystis carinii, l'espèce infectant les rats, et de Pneumocystis murina, l'espèce infectant les souris, ont révélé les mêmes déficiences. Le séquençage du génome de T. deformans a généré un assemblage de 13.3 Mb qui contient 5735 gènes. T. deformans possède les gènes codant pour les enzymes impliquées dans la dégradation des parois cellulaires des plantes, le métabolisme secondaire, le cycle du glyoxylate, la détoxification, la biosynthèse des stérols ainsi que la biosynthèse d'hormones de plantes telles que l'acide abscissique ou l'acide indole 3-acétique. T. deformans possède également des sous-ensembles de gènes présents exclusivement chez des saprophytes ou des pathogènes de plantes, ce qui est consistent avec son mode de vie alternatif saprophyte et pathogène. Des gènes impliqués dans la conjugaison ont été identifiés. L'homothallisme de ce champignon suggère mécanisme de permutation du type conjuguant. Les analyses comparatives ont démontré que 81% des gènes de P. jirovecii sont présent chez les autres membres du sous-embranchement des Taphrinomycotina. Ces gènes sont essentiellement impliqués dans le métabolisme basai. Les gènes spécifiques au genre Pneumocystis représentent 8%, et sont impliqués dans le métabolisme de l'ARN et la signalisation. La signalisation est connue pour être cruciale pour l'interaction des espèces de Pneumocystis avec leur environnement. Les gènes propres à P. jirovecii représentent 11% et codent en majorité pour des protéines dont la fonction est inconnue. Ces gènes en conjonction avec d'autres (par exemple, les glycoprotéines de surface), pourraient être déterminants dans l'interaction de P. jirovecii avec les cellules de l'hôte humain, et être potentiellement responsable de la spécificité d'hôte. P. jirovecii possède un génome de taille réduite à faible pourcentage en GC et récupère très probablement des composés vitaux comme les acides aminés et le cholestérol à partir des poumons humains. De manière consistante, son génome code pour de nombreux transporteurs (22% de ses gènes), qui pourraient jouer un rôle essentiel dans l'acquisition de ces composés. Ces caractéristiques sont généralement observées chez les parasites obligatoires de plusieurs règnes (bactéries, protozoaires, champignons). De plus, les études épidémiologiques n'ont pas réussi à prouver l'existence d'ime forme vivant librement du champignon. Etant donné également l'absence de facteurs de virulence, nos observations suggèrent que P. jirovecii est un parasite obligatoire spécialisé dans la colonisation des poumons humains, ne causant une maladie que chez des individus ayant un système immunitaire compromis. La même conclusion est très probablement applicable à toutes les autres espèces de Pneumocystis dans leur hôte mammifère respectif.
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PURPOSE: To determine and compare the diagnostic performance of magnetic resonance imaging (MRI) and computed tomography (CT) for the diagnosis of tumor extent in advanced retinoblastoma, using histopathologic analysis as the reference standard. DESIGN: Systematic review and meta-analysis. PARTICIPANTS: Patients with advanced retinoblastoma who underwent MRI, CT, or both for the detection of tumor extent from published diagnostic accuracy studies. METHODS: Medline and Embase were searched for literature published through April 2013 assessing the diagnostic performance of MRI, CT, or both in detecting intraorbital and extraorbital tumor extension of retinoblastoma. Diagnostic accuracy data were extracted from included studies. Summary estimates were based on a random effects model. Intrastudy and interstudy heterogeneity were analyzed. MAIN OUTCOME MEASURES: Sensitivity and specificity of MRI and CT in detecting tumor extent. RESULTS: Data of the following tumor-extent parameters were extracted: anterior eye segment involvement and ciliary body, optic nerve, choroidal, and (extra)scleral invasion. Articles on MRI reported results of 591 eyes from 14 studies, and articles on CT yielded 257 eyes from 4 studies. The summary estimates with their 95% confidence intervals (CIs) of the diagnostic accuracy of conventional MRI at detecting postlaminar optic nerve, choroidal, and scleral invasion showed sensitivities of 59% (95% CI, 37%-78%), 74% (95% CI, 52%-88%), and 88% (95% CI, 20%-100%), respectively, and specificities of 94% (95% CI, 84%-98%), 72% (95% CI, 31%-94%), and 99% (95% CI, 86%-100%), respectively. Magnetic resonance imaging with a high (versus a low) image quality showed higher diagnostic accuracies for detection of prelaminar optic nerve and choroidal invasion, but these differences were not statistically significant. Studies reporting the diagnostic accuracy of CT did not provide enough data to perform any meta-analyses. CONCLUSIONS: Magnetic resonance imaging is an important diagnostic tool for the detection of local tumor extent in advanced retinoblastoma, although its diagnostic accuracy shows room for improvement, especially with regard to sensitivity. With only a few-mostly old-studies, there is very little evidence on the diagnostic accuracy of CT, and generally these studies show low diagnostic accuracy. Future studies assessing the role of MRI in clinical decision making in terms of prognostic value for advanced retinoblastoma are needed.
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The nature and assembly of the chlamydial division septum is poorly defined due to the paucity of a detectable peptidoglycan (PG)-based cell wall, the inhibition of constriction by penicillin and the presence of coding sequences for cell wall precursor and remodelling enzymes in the reduced chlamydial (pan-)genome. Here we show that the chlamydial amidase (AmiA) is active and remodels PG in Escherichia coli. Moreover, forward genetics using an E. coli amidase mutant as entry point reveals that the chlamydial LysM-domain protein NlpD is active in an E. coli reporter strain for PG endopeptidase activity (ΔnlpI). Immunolocalization unveils NlpD as the first septal (cell-wall-binding) protein in Chlamydiae and we show that its septal sequestration depends on prior cell wall synthesis. Since AmiA assembles into peripheral clusters, trimming of a PG-like polymer or precursors occurs throughout the chlamydial envelope, while NlpD targets PG-like peptide crosslinks at the chlamydial septum during constriction.
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This paper advocates the adoption of a mixed-methods research design to describe and analyze ego-centered social networks in transnational family research. Drawing on the experience of the Social Networks Influences on Family Formation project (2004-2005), I show how the combined use of network generators and semistructured interviews (N = 116) produces unique data on family configurations and their impact on life course choices. A mixed-methods network approach presents specific advantages for research on children in transnational families. On the one hand, quantitative analyses are crucial for reconstructing and measuring the potential and actual relational support available to children in a context where kin interactions may be hindered by temporary and prolonged periods of separation. On the other hand, qualitative analyses can address strategies and practices employed by families to maintain relationships across international borders and geographic distance, as well as the implications of those strategies for children's well-being.
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There is a lack of dedicated tools for business model design at a strategic level. However, in today's economic world the need to be able to quickly reinvent a company's business model is essential to stay competitive. This research focused on identifying the functionalities that are necessary in a computer-aided design (CAD) tool for the design of business models in a strategic context. Using design science research methodology a series of techniques and prototypes have been designed and evaluated to offer solutions to the problem. The work is a collection of articles which can be grouped into three parts: First establishing the context of how the Business Model Canvas (BMC) is used to design business models and explore the way in which CAD can contribute to the design activity. The second part extends on this by proposing new technics and tools which support elicitation, evaluation (assessment) and evolution of business models design with CAD. This includes features such as multi-color tagging to easily connect elements, rules to validate coherence of business models and features that are adapted to the correct business model proficiency level of its users. A new way to describe and visualize multiple versions of a business model and thereby help in addressing the business model as a dynamic object was also researched. The third part explores extensions to the business model canvas such as an intermediary model which helps IT alignment by connecting business model and enterprise architecture. And a business model pattern for privacy in a mobile environment, using privacy as a key value proposition. The prototyped techniques and proposition for using CAD tools in business model modeling will allow commercial CAD developers to create tools that are better suited to the needs of practitioners.
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Background, aim, and scope A coupled Life Cycle Costing and life cycle assessment has been performed for car-bodies of the Korean Tilting Train eXpress (TTX) project using European and Korean databases, with the objective of assessing environmental and cost performance to aid materials and process selection. More specifically, the potential of polymer composite car-body structures for the Korean Tilting Train eXpress (TTX) has been investigated. Materials and methods This assessment includes the cost of both carriage manufacturing and use phases, coupled with the life cycle environmental impacts of all stages from raw material production, through carriage manufacture and use, to end-of-life scenarios. Metallic carriages were compared with two composite options: hybrid steel-composite and full-composite carriages. The total planned production for this regional Korean train was 440 cars, with an annual production volume of 80 cars. Results and discussion The coupled analyses were used to generate plots of cost versus energy consumption and environmental impacts. The results show that the raw material and manufacturing phase costs are approximately half of the total life cycle costs, whilst their environmental impact is relatively insignificant (3-8%). The use phase of the car-body has the largest environmental impact for all scenarios, with near negligible contributions from the other phases. Since steel rail carriages weigh more (27-51%), the use phase cost is correspondingly higher, resulting in both the greatest environmental impact and the highest life cycle cost. Compared to the steel scenario, the hybrid composite variant has a lower life cycle cost (16%) and a lower environmental impact (26%). Though the full composite rail carriage may have the highest manufacturing cost, it results in the lowest total life cycle costs and lowest environmental impacts. Conclusions and recommendations This coupled cost and life cycle assessment showed that the full composite variant was the optimum solution. This case study showed that coupling of technical cost models with life cycle assessment offers an efficient route to accurately evaluate economic and environmental performance in a consistent way.
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Cancer is the second cause of death after cardio-vascular diseases in economically developed countries. Two of the most commonly used anti-cancer therapies are chemo and radiotherapy. Despite the remarkable advances made in term of delivery and specificity of these two anti-tumor regimens, their toxicity towards healthy tissue remains a limitation. A promising approach to overcome this obstacle would be the utilization of therapeutic peptides that specifically augment the sensitivity of tumoral cells to treatments. Lower therapeutical doses would then be required to kill malignant cells, limiting toxic effects on healthy tissues. It was previously shown in our laboratory that the caspase-3 generated fragment N2 of RasGAP is able to potentiate the genotoxin-induced apoptosis selectively in cancer cells. In this work we show that fragment N2 strictly requires a cytoplasmic localization to deliver its pro-apoptotic effect in genotoxin-treated cancer cells. The tumor sensitizing capacity of fragment N2 was found to reside within the 10 amino acid sequence 317-326. Our laboratory earlier demonstrated that a peptide corresponding to amino acids 317 to 326 of RasGAP fused to the TAT cell permeable moiety, called TAT-RasGAP317.326, is able to sensitize cancer cells, but not normal cells, to genotoxin-induced apoptosis. In the present study we describe the capacity of TAT-RasGAP 317.326 to sensitize tumors to both chemo and radiotherapy in an in vivo mouse model. The molecular mechanism underlying the TAT-RasGAP 317.326-mediated sensitization starts now to be elucidated. We demonstrate that G3BP1, an endoribonuclease binding to amino acids 317-326 of RasGAP, is not involved in the sensitization mechanism. We also provide evidence showing that TAT-RasGAP3 17-326 potentiates the genotoxin-mediated activation of Bax in a tBid-dependent manner. Altogether our results show that TAT-RasGAP 317.326 could be potentially used in cancer therapy as sensitizer, in order to improve the efficacy of chemo and radiotherapy and prolong the life expectancy of cancer patients. Moreover, the understanding of the TAT-RasGAP317.326 mode of action might help to unravel the mechanisms by which cancer cells resist to chemo and radiotherapy and therefore to design more targeted and efficient anti-tumoral strategies.
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Toll-like receptors (TLRs) are pattern recognition receptors playing a fundamental role in sensing microbial invasion and initiating innate and adaptive immune responses. TLRs are also triggered by danger signals released by injured or stressed cells during sepsis. Here we focus on studies developing TLR agonists and antagonists for the treatment of infectious diseases and sepsis. Positioned at the cell surface, TLR4 is essential for sensing lipopolysaccharide of Gram-negative bacteria, TLR2 is involved in the recognition of a large panel of microbial ligands, while TLR5 recognizes flagellin. Endosomal TLR3, TLR7, TLR8, TLR9 are specialized in the sensing of nucleic acids produced notably during viral infections. TLR4 and TLR2 are favorite targets for developing anti-sepsis drugs, and antagonistic compounds have shown efficient protection from septic shock in pre-clinical models. Results from clinical trials evaluating anti-TLR4 and anti-TLR2 approaches are presented, discussing the challenges of study design in sepsis and future exploitation of these agents in infectious diseases. We also report results from studies suggesting that the TLR5 agonist flagellin may protect from infections of the gastrointestinal tract and that agonists of endosomal TLRs are very promising for treating chronic viral infections. Altogether, TLR-targeted therapies have a strong potential for prevention and intervention in infectious diseases, notably sepsis.
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Emotion communication research strongly focuses on the face and voice as expressive modalities, leaving the rest of the body relatively understudied. Contrary to the early assumption that body movement only indicates emotional intensity, recent studies show that body movement and posture also convey emotion specific information. However, a deeper understanding of the underlying mechanisms is hampered by a lack of production studies informed by a theoretical framework. In this research we adopted the Body Action and Posture (BAP) coding system to examine the types and patterns of body movement that are employed by 10 professional actors to portray a set of 12 emotions. We investigated to what extent these expression patterns support explicit or implicit predictions from basic emotion theory, bi-dimensional theory, and componential appraisal theory. The overall results showed partial support for the different theoretical approaches. They revealed that several patterns of body movement systematically occur in portrayals of specific emotions, allowing emotion differentiation. While a few emotions were prototypically encoded by one particular pattern, most emotions were variably expressed by multiple patterns, many of which can be explained as reflecting functional components of emotion such as modes of appraisal and action readiness. It is concluded that further work in this largely underdeveloped area should be guided by an appropriate theoretical framework to allow a more systematic design of experiments and clear hypothesis testing.
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BACKGROUND: Propionic acidemia is an inherited disorder caused by deficiency of propionyl-CoA carboxylase. Although it is one of the most frequent organic acidurias, information on the outcome of affected individuals is still limited. STUDY DESIGN/METHODS: Clinical and outcome data of 55 patients with propionic acidemia from 16 European metabolic centers were evaluated retrospectively. 35 patients were diagnosed by selective metabolic screening while 20 patients were identified by newborn screening. Endocrine parameters and bone age were evaluated. In addition, IQ testing was performed and the patients' and their families' quality of life was assessed. RESULTS: The vast majority of patients (>85%) presented with metabolic decompensation in the neonatal period. Asymptomatic individuals were the exception. About three quarters of the study population was mentally retarded, median IQ was 55. Apart from neurologic symptoms, complications comprised hematologic abnormalities, cardiac diseases, feeding problems and impaired growth. Most patients considered their quality of life high. However, according to the parents' point of view psychic problems were four times more common in propionic acidemia patients than in healthy controls. CONCLUSION: Our data show that the outcome of propionic acidemia is still unfavourable, in spite of improved clinical management. Many patients develop long-term complications affecting different organ systems. Impairment of neurocognitive development is of special concern. Nevertheless, self-assessment of quality of life of the patients and their parents yielded rather positive results.
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OBJECTIVE: To investigate whether better management of chronic conditions by family practices reduces mortality risk. DATA: Two random samples of 5 million patients registered with over 8,000 English family practices followed up for 4 years (2004/5-2007/8). Measures of the quality of disease management for 10 conditions were constructed for each family practice for each year. The outcome measure was an indicator taking the value 1 if the patient died during a specified year, 0 otherwise. STUDY DESIGN: Cross-section and multilevel panel data multiple logistic regressions were estimated. Covariates included age, gender, morbidity, hospitalizations, attributed socio-economic characteristics, and local health care supply measures. PRINCIPAL FINDINGS: Although a composite measure of the quality of disease management for all 10 conditions was significantly associated with lower mortality, only the quality of stroke care was significant when all 10 quality measures were entered in the regression. CONCLUSIONS: The panel data results suggest that a 1 percent improvement in the quality of stroke care could reduce the annual number of deaths in England by 782 [95 percent CI: 423, 1140]. A longer study period may be necessary to detect any mortality impact of better management of other conditions.
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STUDY OBJECTIVES: That sleep deprivation increases the brain expression of various clock genes has been well documented. Based on these and other findings we hypothesized that clock genes not only underlie circadian rhythm generation but are also implicated in sleep homeostasis. However, long time lags have been reported between the changes in the clock gene messenger RNA levels and their encoded proteins. It is therefore crucial to establish whether also protein levels increase within the time frame known to activate a homeostatic sleep response. We report on the central and peripheral effects of sleep deprivation on PERIOD-2 (PER2) protein both in intact and suprachiasmatic nuclei-lesioned mice. DESIGN: In vivo and in situ PER2 imaging during baseline, sleep deprivation, and recovery. SETTINGS: Mouse sleep-recording facility. PARTICIPANTS: Per2::Luciferase knock-in mice. INTERVENTIONS: N/A. MEASUREMENTS AND RESULTS: Six-hour sleep deprivation increased PER2 not only in the brain but also in liver and kidney. Remarkably, the effects in the liver outlasted those observed in the brain. Within the brain the increase in PER2 concerned the cerebral cortex mainly, while leaving suprachiasmatic nuclei (SCN) levels unaffected. Against expectation, sleep deprivation did not increase PER2 in the brain of arrhythmic SCN-lesioned mice because of higher PER2 levels in baseline. In contrast, liver PER2 levels did increase in these mice similar to the sham and partially lesioned controls. CONCLUSIONS: Our results stress the importance of considering both sleep-wake dependent and circadian processes when quantifying clock-gene levels. Because sleep deprivation alters PERIOD-2 in the brain as well as in the periphery, it is tempting to speculate that clock genes constitute a common pathway mediating the shared and well-known adverse effects of both chronic sleep loss and disrupted circadian rhythmicity on metabolic health.