358 research outputs found

    Efficient multi-view ray tracing using edge detection and shader reuse

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    Stereoscopic rendering and 3D stereo displays are quickly becoming mainstream. The natural extension is autostereoscopic multi-view displays, which by the use of parallax barriers or lenticular lenses, can accommodate many simultaneous viewers without the need for active or passive glasses. As these displays, for the foreseeable future, will support only a rather limited number of views, there is a need for high-quality interperspective antialiasing. We present a specialized algorithm for efficient multi-view image generation from a camera line using ray tracing, which builds on previous methods for multi-dimensional adaptive sampling and reconstruction of light elds. We introduce multi-view silhouette edges to detect sharp geometrical discontinuities in the radiance function. These are used to significantly improve the quality of the reconstruction. In addition, we exploit shader coherence by computing analytical visibility between shading points and the camera line, and by sharing shading computations over the camera line

    Plasma disappearance rate of albumin when infused as a 20% solution.

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    BACKGROUND The transcapillary leakage of albumin is increased by inflammation and major surgery, but whether exogenous albumin also disappears faster is unclear. METHODS An intravenous infusion of 3 mL/kg of 20% albumin was given over 30 min to 70 subjects consisting of 15 healthy volunteers, 15 post-burn patients, 15 patients who underwent surgery with minor bleeding, 10 who underwent surgery with major bleeding (mean, 1.1 L) and 15 postoperative patients. Blood Hb and plasma albumin were measured on 15 occasions over 5 h. The rate of albumin disappearance from the plasma was quantitated with population kinetic methodology and reported as the half-life (T1/2). RESULTS No differences were observed for T1/2 between volunteers, post-burn patients, patients who underwent surgery with minor bleeding and postoperative patients. The T1/2 averaged 16.2 h, which corresponds to 3.8% of the amount infused per h. Two groups showed plasma concentrations of C-reactive protein of approximately 60 mg/L and still had a similarly long T1/2 for albumin. By contrast, patients undergoing surgery associated with major hemorrhage had a shorter T1/2, corresponding to 15% of the infused albumin per h. In addition, our analyses show that the T1/2 differ greatly depending on whether the calculations consider plasma volume changes and blood losses. CONCLUSION The disappearance rate of the albumin in 20% preparations was low in volunteers, in patients with moderately severe inflammation, and in postoperative patients

    The Increased Burden of Morbidity Over the Life-Course Among Patients with COPD: A Register-Based Cohort Study in Sweden

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    Carolina Smith,1,2 Ayako Hiyoshi,1,3 Mikael Hasselgren,2,4 Hanna Sandelowsky,5– 7 Björn Ställberg,8 Scott Montgomery1,5,9 1Clinical Epidemiology and Biostatistics, School of Medical Sciences, Faculty of Medicine and Health, Örebro University, Örebro, Sweden; 2Centre for Clinical Research and Education, Region Värmland, Karlstad, Sweden; 3Department of Public Health Sciences, Stockholm University, Stockholm, Sweden; 4School of Medical Sciences, Faculty of Medicine and Health, Örebro University, Örebro, Sweden; 5Clinical Epidemiology Division, Department of Medicine, Solna, Karolinska Institutet, Stockholm, Sweden; 6Department of Neurobiology, Care Sciences and Society, Division of Family Medicine and Primary Care, Karolinska Institutet, Stockholm, Sweden; 7Academic Primary Health Care Center, Region Stockholm, Stockholm, Sweden; 8Department of Public Health and Caring Sciences, Family Medicine and Preventive Medicine, Uppsala University, Uppsala, Sweden; 9Department of Epidemiology and Public Health, University College, London, UKCorrespondence: Carolina Smith, School of Medical Sciences, Faculty of Medicine and HealthÖrebro University, Örebro, 701 82, Sweden, Email [email protected]: Patients with a diagnosis of chronic obstructive pulmonary disease (COPD) often have other chronic disorders. This study aims to describe the life-course pattern of morbidity in patients with COPD.Patients and Methods: Among all residents aged 50– 90 years in Sweden in 1997, people with a hospital COPD diagnosis were identified using Swedish national registers (1997– 2018). Each patient with COPD was matched by sex, birthyear and county of residency with up to five COPD-free controls. Other chronic disease diagnoses were identified during 1987– 2018. Conditional logistic regression calculated risk of diseases diagnosed prior to first COPD diagnosis, producing odds ratios (OR) and 95% confidence intervals (95% CI). Cox regression estimated risk of diagnoses after first COPD diagnosis, producing hazard ratios (HR) and 95% CI.Results: Among 2,706,814 individuals, 225,159 (8.3%) had COPD. The nested case–control sample included 223,945 COPD-cases with 1,062,731 controls. Prior to first COPD diagnosis, future COPD patients had higher risks than controls for most examined conditions. Highest risks were seen for chronic heart failure (OR = 3.25, 3.20– 3.30), peripheral arterial disease (OR = 3.12, 3.06– 3.18) and lung cancer (OR = 12.73, 12.12– 13.37). Following the COPD diagnosis, individuals with COPD had higher risks of most conditions than individuals without COPD. Chronic heart failure (HR = 3.50, 3.46– 3.53), osteoporosis (HR = 3.35, 3.30– 3.42), depression (HR = 2.58, 2.53– 2.64) and lung cancer (HR = 6.04, 5.90– 6.18) predominated. The risk of vascular dementia was increased after COPD diagnosis (HR = 1.53, 1.48– 1.58) but not Alzheimer’s disease.Conclusion: Accumulation of chronic morbidity may precede COPD. Following the diagnosis, an increased burden of cardiovascular disease and cancer is to be expected, but subsequent depression, osteoporosis, and vascular dementia should also be noted. Management strategies for patients with COPD should consider the higher-than-average risk of multimorbidity.Keywords: COPD, multimorbidity, register-stud

    Emergency pulpotomy in relieving acute dental pain among Tanzanian patients

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    BACKGROUND: In Tanzania, oral health services are mostly in the form of dental extractions aimed at alleviating acute dental pain. Conservative methods of alleviating acute dental pain are virtually non-existent. Therefore, it was the aim of this study to determine treatment success of emergency pulpotomy in relieving acute dental pain. METHODS: Setting: School of Dentistry, Muhimbili National Hospital, Dar es Salaam, Tanzania. Study design: Longitudinal study. Participants: 180 patients who presented with dental pain due to acute irreversible pulpitis during the study period between July and August 2001. Treatment and evaluation: Patients were treated by emergency pulpotomy on permanent posterior teeth and were evaluated for pain after one, three and six week's post-treatment. Pain, if present, was categorised as either mild or acute. RESULTS: Of the patients with treated premolars, 25 (13.9%) patients did not experience pain at all while 19 (10.6%) experienced mild pain. None of the patients with treated premolars experienced acute pain. Among 136 patients with treated molars 56 (31%) did not experience any pain, 76 (42.2%) experienced mild pain and the other 4 (2.2%) suffered acute pain. CONCLUSION: The short term treatment success of emergency pulpotomy was high being 100% for premolars and 97.1% for molars, suggesting that it can be recommended as a measure to alleviate acute dental pain while other conservative treatment options are being considered

    Research productivity and academics’ conceptions of research

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    This paper asks the question: do people with different levels of research productivity and identification as a researcher think of research differently? It discusses a study that differentiated levels of research productivity among English and Australian academics working in research-intensive environments in three broad discipline areas: science, engineering and technology; social science and humanities; and medicine and health sciences. The paper explores the different conceptions of research held by these academics in terms of their levels of research productivity, their levels of research training, whether they considered themselves an active researcher and a member of a research team, and their disciplinary differences

    Exhaled nitric oxide and urinary EPX levels in infants: a pilot study

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    <p>Abstract</p> <p>Background</p> <p>Objective markers of early airway inflammation in infants are not established but are of great interest in a scientific setting. Exhaled nitric oxide (FeNO) and urinary eosinophilic protein X (uEPX) are a two such interesting markers.</p> <p>Objective</p> <p>To investigate the feasibility of measuring FeNO and uEPX in infants and their mothers and to determine if any relations between these two variables and environmental factors can be seen in a small sample size. This was conducted as a pilot study for the ongoing Swedish Environmental Longitudinal Mother and child Asthma and allergy study (SELMA).</p> <p>Methods</p> <p>Consecutive infants between two and six months old and their mothers at children's health care centres were invited, and 110 mother-infant pairs participated. FeNO and uEPX were analysed in both mothers and infants. FeNO was analyzed in the mothers online by the use of the handheld Niox Mino device and in the infants offline from exhaled air sampled during tidal breathing. A 33-question multiple-choice questionnaire that dealt with symptoms of allergic disease, heredity, and housing characteristics was used.</p> <p>Results</p> <p>FeNO levels were reduced in infants with a history of upper respiratory symptoms during the previous two weeks (p < 0.002). There was a trend towards higher FeNO levels in infants with windowpane condensation in the home (p < 0.05). There was no association between uEPX in the infants and the other studied variables.</p> <p>Conclusion</p> <p>The use of uEPX as a marker of early inflammation was not supported. FeNO levels in infants were associated to windowpane condensation. Measuring FeNO by the present method may be an interesting way of evaluating early airway inflammation. In a major population study, however, the method is difficult to use, for practical reasons.</p

    Expression of the ubiquitin-proteasome pathway and muscle loss in experimental cancer cachexia

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    Muscle protein degradation is thought to play a major role in muscle atrophy in cancer cachexia. To investigate the importance of the ubiquitin-proteasome pathway, which has been suggested to be the main degradative pathway mediating progressive protein loss in cachexia, the expression of mRNA for proteasome subunits C2 and C5 as well as the ubiquitin-conjugating enzyme, E214k, has been determined in gastrocnemius and pectoral muscles of mice bearing the MAC16 adenocarcinoma, using competitive quantitative reverse transcriptase polymerase chain reaction. Protein levels of proteasome subunits and E214k were determined by immunoblotting, to ensure changes in mRNA were reflected in changes in protein expression. Muscle weights correlated linearly with weight loss during the course of the study. There was a good correlation between expression of C2 and E214k mRNA and protein levels in gastrocnemius muscle with increases of 6–8-fold for C2 and two-fold for E214k between 12 and 20% weight loss, followed by a decrease in expression at weight losses of 25–27%, although loss of muscle protein continued. In contrast, expression of C5 mRNA only increased two-fold and was elevated similarly at all weight losses between 7.5 and 27%. Both proteasome functional activity, and proteasome-specific tyrosine release as a measure of total protein degradation was also maximal at 18–20% weight loss and decreased at higher weight loss. Proteasome expression in pectoral muscle followed a different pattern with increases in C2 and C5 and E214k mRNA only being seen at weight losses above 17%, although muscle loss increased progressively with increasing weight loss. These results suggest that activation of the ubiquitin-proteasome pathway plays a major role in protein loss in gastrocnemius muscle, up to 20% weight loss, but that other factors such as depression in protein synthesis may play a more important role at higher weight loss
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