Light field display with ellipsoidal mirror array and single projector.

We present a method to create light field display using a single projector and an array of plane mirrors. Mirrors can reproduce densely arranged virtual projectors regardless of the physical size of the real projector, thus producing a light field display of competitive ray density. We propose an ellipsoidal geometric framework and a design pipeline, and use parametric modelling technique to automatically generate the display configurations satisfying target design parameters. Three units of mirror array light field display systems have been implemented to evaluate the proposed methodologies. More importantly, we have experimentally verified that the high-density light field produced by our method can naturally evoke accommodation of the eyes, thereby reducing the vergence-accommodation conflict. The mirror array approach allows flexible trading between the spatial and angular resolutions for accommodating different applications, thus providing a practical solution to realize projection-based light field display.

Outline-etching image segmentation reveals enhanced cell chirality through intercellular alignment.

Cells cultured on micropatterns exhibit a chiral orientation, which may underlie the development of left-right asymmetry in tissue microarchitectures. To investigate this phenomenon, fluorescence staining of nuclei has been used to reveal such orientation. However, for images with high cell density, analysis is difficult because of the overlapping nuclei. Here, we report an image processing method that can acquire cell orientations within dense cell populations. After initial separation based on Boolean addition of binarized images using global and adaptive thresholds, the overlapping nucleus contours in the binarized images were segmented by iteratively etching the outlines of nuclei, which allowed the orientations of each cell to be extracted from densely packed cell clusters. In applying this technique to cultured C2C12 myoblasts in micropatterned stripes on different substrates, we found an enhanced chiral orientation on glass substrate. More important, this enhanced chirality was consistently observed with increased intercellular alignment and independent of cell-cell distance or cell density, suggesting that intercellular alignment plays a role in determining the chiral orientation. By segmenting single cells with intact orientation, this technique offers an automated method for quantitative analysis with improved accuracy, providing an essential tool for studying left-right asymmetry and other morphogenic dynamics in tissue formation.

Effects of exercise amount and intensity on abdominal obesity and glucose tolerance in obese adults: a randomized trial.

BACKGROUND: Exercise reduces obesity and related glucose tolerance, but whether increasing exercise intensity offers additional benefit at fixed exercise amounts is unknown. OBJECTIVE: To determine the separate effects of exercise amount and intensity on abdominal obesity and glucose tolerance. DESIGN: 24-week, single-center, parallel-group trial from 2009 to 2013. (ClinicalTrials.gov: NCT00955071). SETTING: Kingston, Ontario, Canada. PARTICIPANTS: 300 abdominally obese adults. INTERVENTION: Control (no exercise) (n = 75) or 5 weekly sessions of low-amount, low-intensity exercise (LALI) (180 and 300 kcal/session for women and men, respectively, at 50% of maximum oxygen consumption [V̇o2peak]) (n = 73); high-amount, low-intensity exercise (HALI) (360 and 600 kcal/session, respectively, at 50% of V̇o2peak) (n = 76); or high-amount, high-intensity exercise (HAHI) (360 and 600 kcal/session, respectively, at 75% of V̇o2peak) (n = 76). Daily unsupervised physical activity and sedentary time were measured by accelerometer. MEASUREMENTS: Waist circumference and 2-hour glucose level (primary outcomes) and cardiorespiratory fitness and measures of insulin action (secondary measurements). RESULTS: 217 participants (72.3%) completed the intervention. Mean exercise time in minutes per session was 31 (SD, 4.4) for LALI, 58 (SD, 7.6) for HALI, and 40 (SD, 6.2) for HAHI. Daily unsupervised physical activity and sedentary time did not change in any exercise group versus control (P > 0.33). After adjustment for age and sex in a linear mixed model, reductions in waist circumference were greater in the LALI (-3.9 cm [95% CI, -5.6 to -2.3 cm]; P < 0.001), HALI (-4.6 cm [CI, -6.2 to -3.0 cm]; P < 0.001), and HAHI (-4.6 cm [CI, -6.3 to -2.9 cm]; P < 0.001) groups than the control group but did not differ among the exercise groups (P > 0.43). After adjustment for covariates, reductions in 2-hour glucose level were greater in the HAHI group (-0.7 mmol/L [-12.5 mg/dL] [CI, -1.3 to -0.1 mmol/L {-23.5 to -1.5 mg/dL}]; P = 0.027) than the control group but did not differ for the LALI or HALI group versus the control group (P > 0.159). Weight loss was greater in all exercise groups than the control group (P < 0.001); however, reduction in body weight did not differ among the exercise groups (P > 0.182). LIMITATION: The clinical importance of reducing 2-hour glucose level in nondiabetic adults remains undetermined. CONCLUSION: Fixed amounts of exercise independent of exercise intensity resulted in similar reductions in abdominal obesity. Reduction in 2-hour glucose level was restricted to high-intensity exercise.

Scalable pattern formation of skeletal myotubes by synergizing microtopographic cues and chiral nematics of cells.

Topographical cues have been widely used to facilitate cell fusion in skeletal muscle formation. However, an unexpected yet consistent chiral orientation of myotubes deviating from the groove boundaries is commonly observed but has long been unattended. In this study, we report a method to guide the formation of skeletal myotubes into scalable and controlled patterns. By inducing C2C12 myoblasts onto grooved patterns with different widths (from 0.4 to 200µm), we observed an enhanced chiral orientation of cells developing on wide grooves (50 and 100µm width) since the first day of induction. Active chiral nematics of cells involving cell migration and chiral rotation of the cell nucleus subsequently led to a unified chiral orientation of the myotubes. Importantly, these chiral myotubes were formed with enhanced length, diameter, and contractility on wide grooves. Treatment of latrunculin A (Lat A) suppressed the chiral rotation and migration of cells as well as the myotube formation, suggesting the essence of chiral nematics of cells for myogenesis. Finally, by arranging wide grooved/striped patterns with corresponding compensation angles to synergize microtopographic cues and chiral nematics of cells, intricate and scalable patterns of myotubes were formed, providing a strategy for engineering skeletal muscle tissue formation.

Manual and automated office measurements in relation to awake ambulatory blood pressure monitoring.

BACKGROUND: Automated blood pressure (BP) devices are commonly used in doctor's offices. How BP measured on these devices relates to ambulatory BP monitoring is not clear. OBJECTIVE: To assess how well office-based manual and automated BP predicts ambulatory BP. METHODS: Using data on 654 patients, we assessed how well sphygmomanometer measurements and measurements taken with an automated device (BpTRU) predicted results on ambulatory BP monitoring. We assess positive and negative predictive values and overall accuracy. We look at different cut-points for systolic (130, 135 and 140 mmHg) and diastolic (80, 85 and 90 mmHg) BP. RESULTS: A single automated office BP (AOBP) assessment provides superior predictive values and overall accuracy compared to three manual office BP assessments. For systolic BP, the predictive values are ≤69% for any of the cut-points while the positive predictive values for the single automated measurement is between 80.0% and 86.9% and the overall accuracy gets as high as 74% for the 130 mmHg cut-point. For diastolic BP, the automated readings are also more predictive but in this case, it is the negative predictive values that are better, as well as the overall accuracy. CONCLUSIONS: Based on the results, we suggest that 135/85 mmHg continue to be used as the cut-point defining high BP with the BpTRU device. However, future research might suggests that values in a grey zone between 130-139 mmHg systolic and 80-89 mmHg diastolic be confirmed using ambulatory BP monitoring. As well, three AOBP assessments might produce much greater accuracy than the single AOBP assessment used in the study.

Reliability of lower limb alignment measures using an established landmark-based method with a customized computer software program.

The objective of the study was to evaluate the reliability of frontal plane lower limb alignment measures using a landmark-based method by (1) comparing inter- and intra-reader reliability between measurements of alignment obtained manually with those using a computer program, and (2) determining inter- and intra-reader reliability of computer-assisted alignment measures from full-limb radiographs. An established method for measuring alignment was used, involving selection of 10 femoral and tibial bone landmarks. (1) To compare manual and computer methods, we used digital images and matching paper copies of five alignment patterns simulating healthy and malaligned limbs drawn using AutoCAD. Seven readers were trained in each system. Paper copies were measured manually and repeat measurements were performed daily for 3 days, followed by a similar routine with the digital images using the computer. (2) To examine the reliability of computer-assisted measures from full-limb radiographs, 100 images (200 limbs) were selected as a random sample from 1,500 full-limb digital radiographs which were part of the Multicenter Osteoarthritis Study. Three trained readers used the software program to measure alignment twice from the batch of 100 images, with two or more weeks between batch handling. Manual and computer measures of alignment showed excellent agreement (intraclass correlations [ICCs] 0.977-0.999 for computer analysis; 0.820-0.995 for manual measures). The computer program applied to full-limb radiographs produced alignment measurements with high inter- and intra-reader reliability (ICCs 0.839-0.998). In conclusion, alignment measures using a bone landmark-based approach and a computer program were highly reliable between multiple readers.

An agar gel membrane-PDMS hybrid microfluidic device for long term single cell dynamic study.

Significance of single cell measurements stems from the substantial temporal fluctuations and cell-cell variability possessed by individual cells. A major difficulty in monitoring surface non-adherent cells such as bacteria and yeast is that these cells tend to aggregate into clumps during growth, obstructing the tracking or identification of single-cells over long time periods. Here, we developed a microfluidic platform for long term single-cell tracking and cultivation with continuous media refreshing and dynamic chemical perturbation capability. The design highlights a simple device-assembly process between PDMS microchannel and agar membrane through conformal contact, and can be easily adapted by microbiologists for their routine laboratory use. The device confines cell growth in monolayer between an agar membrane and a glass surface. Efficient nutrient diffusion through the membrane and reliable temperature maintenance provide optimal growth condition for the cells, which exhibited fast exponential growth and constant distribution of cell sizes. More than 24 h of single-cell tracking was demonstrated on a transcription-metabolism integrated synthetic biological model, the gene-metabolic oscillator. Single cell morphology study under alcohol toxicity allowed us to discover and characterize cell filamentation exhibited by different E. coli isobutanol tolerant strains. We believe this novel device will bring new capabilities to quantitative microbiology, providing a versatile platform for single cell dynamic studies.

The significance of biological variation in the diagnosis of testosterone deficiency, and consideration of the relevance of total, free and bioavailable testosterone determinations.

PURPOSE: The diagnosis of testosterone deficiency syndrome is based on clinical manifestations and documentation of low testosterone. Which biochemical tests to use and the importance of morning sampling are still controversial. Biological variation (including interindividual and intraindividual biological variation) must be considered when interpreting individual results as it determines the usefulness of reference intervals and the change (reference change value) necessary for a significant difference between results. MATERIALS AND METHODS: A total of 87 healthy men (50 to 70+ years old) provided blood in the morning of the first day, and 4 weeks later in the morning and afternoon. Samples were frozen (-70C) and analyzed in the same run for serum testosterone, sex hormone-binding globulin and albumin, and bioavailable testosterone and free testosterone were calculated. RESULTS: Serum testosterone was lower in the afternoon by 1.5 nmol/l (43 ng/dl, p <0.05), with larger changes observed with higher morning values. However, this diurnal effect was dwarfed by the normal biological variation observed for repeat morning samples (serum testosterone +/- 4 nmol/l [115 ng/dl]). Between day intra-individual biological variation for morning serum testosterone was 18.7% while within day intra-individual biological variation was 12.9%. A change of 52% (reference change value) is necessary between serial morning results to confirm a significant difference. The biological variation parameters of calculated bioavailable testosterone and calculated free testosterone confer no advantage over total testosterone. CONCLUSIONS: Marked individuality of serum testosterone is evident even in healthy men. Because intraindividual biological variation is less than interindividual biological variation, reference intervals are marginally useful. The homeostatic set point of a patient could decrease by half and still be within the reference interval. Prospective establishment of an individual's baseline over repeated measurements or symptoms regardless of serum testosterone concentration should be used to guide clinical decisions.

A primary care pragmatic cluster randomized trial of the use of home blood pressure monitoring on blood pressure levels in hypertensive patients with above target blood pressure.

BACKGROUND: The measurement of blood pressure (BP) at home by patients with hypertension is increasingly used to assess and monitor BP. Evidence for its effectiveness in improving BP control is mixed. METHODS: To determine if home BP monitoring improves BP a pragmatic cluster randomized contolled trial was carried out in family practices in southeastern Ontario, Canada. Family practice patients with uncontrolled hypertension were recruited to the trail. Patients were divided into two groups: one with at least weekly measurements of BP at home, recording those measurements and showing those to the family physician during office visits for hypertension and the control group were given usual care. The primary outcome was mean awake BP on ambulatory monitoring at 6- and 12-month follow-up and the secondary outcomes were mean BP on full 24-hour ambulatory blood pressure monitoring (ABPM), mean sleep BP on ABPM and BP on the BpTRU device, all at 6- and 12-month follow-up. RESULTS: Home BP monitoring did not improve BP compared to usual care at 12-month follow-up: mean awake systolic BP on ABPM [141.1 versus 142.8 mmHg, mean difference 1.7 mmHg; 95% confidence interval (CI) -0.6 to 4.0, P = 0.314] and mean awake diastolic BP on ABPM (78.7 versus 79.4 mmHg, mean difference 0.7 mmHg; 95% CI -7.7 to 9.1, P = 0.398). Similar negative results were obtained for men and women separately. However, outcomes using the full 24-hour ABPM and the BpTRU device showed a significantly lower diastolic BP at 12 months. When analysis was done by sex, this effect was shown to be only in men. CONCLUSION: Home BP monitoring may improve BP control in men with hypertension.

Effectiveness of a protocol-based strategy for achieving better blood pressure control in general practice.

BACKGROUND: There continues be a problem with the proportion of treated hypertension patients who are actually at recommended blood pressure targets. OBJECTIVE: Is an intensive protocol-based strategy for achieving blood pressure control effective in family practice and will family physicians and their hypertensive patients adhere to such a protocol. METHODS: Design of the study is a cluster randomized controlled trial at the Centre for Studies in Primary Care, Queen's University, Kingston, Ontario. Participants were 19 family physicians and 156 (98 intervention group and 58 control group) of their patients in and around the Kingston area. Patients were eligible if they had a diagnosis of hypertension and had not yet achieved their target blood pressure. Patients in the intervention group were managed according to a protocol that involved seeing their family doctor every 2 weeks over a 16-week period and having their antihypertensive medication regimen adjusted at each visit if target was not achieved. This was compared to usual care. Main outcomes were primary effectiveness outcome measured at 12 months was the differences in blood pressure between baseline and 12 months in the two groups. Secondary effectiveness outcomes included rates of achieving BP target and compliance with protocol by physicians and patients. Adherence outcomes were assessed by determining the number of visits made during the 16-week intervention period and the increase in the number of drugs being used. RESULTS: Of the patients enrolled, 72 (74%) from the intervention group and 41 (71%) in the control group were available for analysis. Improvement between baseline and 12-month follow-up was significantly better for the intervention group than the control for diastolic mean daytime BP on 24 hours ambulatory blood pressure monitoring (4.5 mmHg reduction versus 0.5 mmHg reduction) and for both systolic (14.7 mmHg reduction versus 2.7 mmHg reduction) and diastolic (7.4 mmHg reduction versus 0.6 mmHg increase) blood pressure on BpTRU. Of the 98 patients in the intervention, 80% attended four or more of the eight visits and 25% attended all eight visits; physicians increased the number or dosage of drugs the patient was taking in 52% of the visits. Conclusions. An intensive, protocol-based, management approach to achieving blood pressure control in hypertensive patients in family practice is effective and works even when there is flexibility built into the algorithm to allow family physicians to use their judgement in individual patients.

Microfluidic immunoassay for detection of serological antibodies: A potential tool for rapid evaluation of immunity against SARS-CoV-2.

In December 2019, coronavirus disease 2019 became a pandemic affecting more than 200 countries and territories. Millions of lives are still affected because of mandatory quarantines, which hamstring economies and induce panic. Immunology plays a major role in the modern field of medicine, especially against virulent infectious diseases. In this field, neutralizing antibodies are heavily studied because they reflect the level of infection and individuals' immune status, which are essential when considering resumption of work, flight travel, and border entry control. More importantly, it also allows evaluating the antiviral vaccine efficacy as vaccines are still known for being the ultimate intervention method to inhibit the rapid spread of virulent infectious diseases. In this Review, we first introduce the host immune response after the infection of SARS-CoV-2 and discuss the latest results using conventional immunoassays. Next, as an enabling platform for detection with sufficient sensitivity while saving analysis time and sample size, the progress of microfluidic-based immunoassays is discussed and compared based on surface modification, microfluidic kinetics, signal output, signal amplification, sample matrix, and the detection of anti-SARS-CoV-2 antibodies. Based on the overall comparison, this Review concludes by proposing the future integration of visual quantitative signals on microfluidic devices as a more suitable approach for general use and large-scale surveillance.

Early Committed Clockwise Cell Chirality Upregulates Adipogenic Differentiation of Mesenchymal Stem Cells.

Cell chirality is observed with diverse forms and coordinates various left-right (LR) asymmetry in tissue morphogenesis. To give rise to such diversity, cell chirality may be coupled with cell differentiation. Here, using micropatterned human mesenchymal stem cells (hMSCs), an early committed clockwise (CW) cell chirality that can itself upregulate the adipogenic differentiation is reported. hMSC chirality enables a positively tilted chiral orientation on micropatterned stripes. When cultured as single cells on circular micropatterns, an anticlockwise (ACW)-biased nucleus rotation and swirling pattern of actin filament are observed. Interestingly, with adipogenic induction for 3-6 days, such chirality is reversed to negative chiral orientation and CW-biased rotation, which is earlier than the maturation of other differentiation markers, and consistently expressed in terminally differentiated adipocytes. Using latrunculin A (LatA), cytochalasin D (CD), and nocodazole (Noco) that forces a CW-biased actin filament and nucleus rotation resembling the early differentiated chirality upon adipogenic induction, an upregulation of adipogenic differentiation is found. The result demonstrates that the early differentiated chirality may serve as a mechanical precursor to engage the lineage commitment, suggesting a feedback mechanism of chiral actin in regulating cell differentiation and LR morphogenesis.

Age at diagnosis of autism spectrum disorders in four regions of Canada.

OBJECTIVES: Early diagnosis of autism spectrum disorders ("autism") may lead to better treatment outcomes, reduces the stress parents experience when they do not understand the reasons for their child's behaviour, and empowers parents to make choices such as seeking genetic counseling. We examined the age at which Canadian children are diagnosed with autism, and analyzed whether there are geographic or temporal variations or differences by sex or diagnostic subtype. METHODS: As part of an autism surveillance program, in 2002/2003 we began collecting information on children with autism in Manitoba, Southeastern Ontario, Prince Edward Island, and Newfoundland and Labrador. For the analysis presented in this paper, we included children identified for our surveillance program who were diagnosed between 1997 and 2005 (n = 769). RESULTS: We found significant inter-regional differences in age at diagnosis, with Newfoundland and Labrador having the lowest median age at diagnosis (39.0 months) and Southeastern Ontario the highest (55.0 months). Diagnostic subtype was significantly associated with age at diagnosis in all regions. Southeastern Ontario was the only region where the overall age at diagnosis increased over time (p = 0.004), although in Manitoba the age at which children were diagnosed with PDD-NOS also increased significantly over the study period (p = 0.021). CONCLUSIONS: Our findings demonstrate that there are geographic differences and other sources of variation in the age at which Canadian children are diagnosed with autism. Further study is warranted to understand the factors contributing to these differences. Such research would inform best practices for early detection and timely access to treatment.

Remnant Effects of Culture Density on Cell Chirality After Reseeding.

Proper muscle function requires specific orientation of myotubes. Cell chirality, a mechanical behavior of cells, may participate in myogenesis and give rise to left-right (LR) orientation of muscle tissue. Thus, it is essential to understand the factors effecting the cell chirality. Here, using C2C12 cells as a model system, we report that prior culture condition with high/low density can create remnant effects on cell chirality after reseeding. C2C12 myoblasts were first conditioned by a series of subcultures with plating density at 2200 cells/cm2 (low density) or 22 000 cells/cm2 (high density). After reseeding on micropatterned stripes fabricated on glass or polydimethylsiloxane (PDMS) substrates, we found that the cells after low-density cultures exhibited a reduced cell aspect ratio and intercellular alignment, leading to an attenuated chiral orientation only appearing on glass substrate. In contrast, chiral orientation was observed in cells after high-density culture on both substrates. By comparing it to the original cells without being subcultured with high/low density, we found that the series of low-density cultures disorganized the formation of actin rings in single cells, which is an essential structure for cell chirality. Moreover, by using high-density culture supplemented with inhibitors of actin polymerization, the effect of low-density cultures was recaptured, suggesting that the series of subcultures with high/low density may be an in vitro aging process that modifies the actin cytoskeleton, causing a remnant attenuation of cell chirality even after trypsin digestion and reseeding. Together, our result suggests a mechanistic insight of how cytoskeletal structures "memorize" the previous experience through modification of the actin filament, opening up new possibilities for morphogenesis and mechanobiology.

Prevalence and associations of coronary artery calcification in patients with stages 3 to 5 CKD without cardiovascular disease.

BACKGROUND: Patients with chronic kidney disease (CKD) have a high prevalence of coronary artery calcification, suggesting that CKD itself is a risk factor for its occurrence. Existing studies are confounded by the inclusion of patients who may not have CKD by means of diagnostic criteria and by failing to account for existing cardiovascular disease. STUDY DESIGN: Cross-sectional study. PARTICIPANTS & SETTING: 119 patients with CKD stages 3 to 5 (excluding dialysis) without known cardiovascular disease receiving care at a single center in Kingston, Ontario, Canada. PREDICTORS: Glomerular filtration rate was estimated (eGFR) by using the 4-variable Modification of Diet in Renal Disease Study equation. Traditional and nontraditional coronary artery calcification risk factors were defined a priori. OUTCOMES: Coronary artery calcification was measured by means of multislice computed tomographic scan. RESULTS: Mean and median coronary artery calcification scores were 566.5 +/- 1,108 and 111 (interquartile range, 2 to 631.5), respectively. A total of 32.8% of patients showed little calcification (score, 0 to 10). Calcification correlated with age (r = 0.44; P < 0.001), body mass index (r = 0.28; P = 0.002), high-density lipoprotein cholesterol level (r = -0.23; P = 0.01), diabetes mellitus (r = 0.23; P = 0.01), and cardiovascular risk score (r = 0.35; P < 0.001). By means of multivariable linear regression controlling for eGFR and diabetes mellitus, age (beta = 0.05; 95% confidence interval, 0.03 to 0.06; P < 0.001), body mass index (beta = 0.04; 95% confidence interval, 0.02 to 0.07; P = 0.001), and serum calcium level (beta = 0.9; 95% confidence interval, 0.15 to 1.6; P = 0.02), were risk factors for coronary artery calcification. LIMITATIONS: Inadequate sample size and uncontrolled confounding are possible limitations, but are unlikely to have changed the main study findings. CONCLUSIONS: In this study, traditional cardiovascular disease risk factors and serum calcium level were associated with coronary artery calcification. No association was shown with eGFR. Studies exploring protective mechanisms against coronary artery calcification are needed.

Prevalence, incidence, and clinical resolution of insulin resistance in critically ill patients: an observational study.

BACKGROUND: The primary objective of this study was to measure the prevalence, incidence, and resolution of insulin resistance (IR) in critically ill patients. A secondary objective was to explore the relationship between IR and inflammatory cytokines, coagulation abnormalities, and clinical outcomes. DESIGN: Prospective observational study. METHODS: The setting was the medical/surgical intensive care unit (ICU). We enrolled consecutive patients within 24 hours of admission to the ICU. Blood samples were collected daily until discharge, death, or a maximum of 10 days, then sent for measurement of markers of IR, inflammation, and coagulation. Charts were reviewed retrospectively to determine clinical outcomes. The homeostasis model assessment method (HOMA) was used to determine IR; a score of > or = 4 represents insulin resistance. RESULTS: A total of 96 patients were enrolled. Upon admission, 64 (67%) patients had overt IR (glucose > 7 mmol/L or insulin use), 9 (9.4%) had non-overt IR (normal glucose but HOMA > 4), and 23 (24%) were insulin sensitive (IS; normal glucose and HOMA < 4). During the course of ICU stay, an additional 16 patients developed overt IR, while 10 (10%) remained IS. There were no significant differences in inflammatory markers, coagulation tests, and clinical outcomes between IR and IS patients. There was no significant correlation between HOMA and inflammatory markers and coagulation markers. In a multivariable regression model, only interleukin-6 levels were significantly associated with mortality. CONCLUSIONS: A high proportion of critically ill patients have IR. There may not be any significant relationship between IR and measures of inflammation, coagulation, and clinical outcomes in a heterogeneous population of critically ill patients.

The prevalence of blebs or bullae among young healthy adults: a thoracoscopic investigation.

BACKGROUND: To determine the prevalence of blebs or bullae using thoracoscopy in young healthy adults, and to compare patient characteristics among those with and without blebs. METHODS: Bilateral thoracoscopic evaluation of the lungs was performed in healthy individuals who were referred for thoracoscopic thoracic sympathectomy for essential hyperhidrosis. Participants were enrolled into a registry and followed for up to 9 years. RESULTS: Analysis was performed on 250 consecutive cases. Blebs were observed in 15 of 250 individuals (6%; male, n = 6; female, n = 9; mean age, 25.3 years; range, 15 to 51 years). Individuals with blebs had a significantly lower body mass index (BMI) [mean +/- SD, 20.7 +/- 2.4 kg/m(2) vs 22.7 +/- 3.4 kg/m(2); p = 0.027] when compared to individuals without blebs, whereas all other parameters were similar. Blebs were most prevalent among slim individuals (BMI < 22 kg/m(2)) who smoked (odds ratio, 5.9; 95% confidence interval, 1.19 to 29.20). CONCLUSION: Blebs were identified thoracoscopically in 6% of young healthy adults with no underlying lung disease. Low BMI in combination with smoking may have an important role in the development of pleural blebs in healthy young adults; however, these changes may not be responsible for future spontaneous pneumothoraces.

Discrete Element Model for Suppression of Coffee-Ring Effect.

When a sessile droplet evaporates, coffee-ring effect drives the suspended particulate matters to the droplet edge, eventually forming a ring-shaped deposition. Because it causes a non-uniform distribution of solid contents, which is undesired in many applications, attempts have been made to eliminate the coffee-ring effect. Recent reports indicated that the coffee-ring effect can be suppressed by a mixture of spherical and non-spherical particles with enhanced particle-particle interaction at air-water interface. However, a model to comprehend the inter-particulate activities has been lacking. Here, we report a discrete element model (particle system) to investigate the phenomenon. The modeled dynamics included particle traveling following the capillary flow with Brownian motion, and its resultant 3D hexagonal close packing of particles along the contact line. For particles being adsorbed by air-water interface, we modeled cluster growth, cluster deformation, and cluster combination. We found that the suppression of coffee-ring effect does not require a circulatory flow driven by an inward Marangoni flow at air-water interface. Instead, the number of new cluster formation, which can be enhanced by increasing the ratio of non-spherical particles and the overall number of microspheres, is more dominant in the suppression process. Together, this model provides a useful platform elucidating insights for suppressing coffee-ring effect for practical applications in the future.

The Ontario Asthma Regional Variation Study: emergency department visit rates and the relation to hospitalization rates.

BACKGROUND: Hospitalization rates for asthma vary more than threefold across regions of Ontario. It is not known whether this variation is primarily due to regional differences in the rate of emergency department (ED) visits or hospital admissions. OBJECTIVE: To determine the variation in ED visit rates for asthma in Ontario, and the relation between ED visit rates and hospitalization rates. DESIGN, SETTING, AND PATIENTS: We studied patients with an ED disposition diagnosis of asthma in a stratified sample of 16 hospitals (pediatric facilities, 13; adult facilities, 14) over a 1-year period. Pediatric patients were defined as those patients who were

What matters most in end-of-life care: perceptions of seriously ill patients and their family members.

BACKGROUND: Initiatives to improve end-of-life care are hampered by our nascent understanding of what quality care means to patients and their families. The primary purpose of this study was to describe what seriously ill patients in hospital and their family members consider to be the key elements of quality end-of-life care. METHODS: After deriving a list of 28 elements related to quality end-of-life care from existing literature, focus groups with experts and interviews with patients, we administered a face-to-face questionnaire to older patients with advanced cancer and chronic end-stage medical disease and their family members in 5 hospitals across Canada to assess their perspectives on the importance. We compared differences in ratings across various subgroups of patients and family members. RESULTS: Of 569 eligible patients and 176 family members, 440 patients (77%) and 160 relations (91%) agreed to participate. The elements rated as "extremely important" most frequently by the patients were "To have trust and confidence in the doctors looking after you" (55.8% of respondents), "Not to be kept alive on life support when there is little hope for a meaningful recovery" (55.7%), "That information about your disease be communicated to you by your doctor in an honest manner" (44.1%) and "To complete things and prepare for life's end - life review, resolving conflicts, saying goodbye" (43.9%). Significant differences in ratings of importance between patient groups and between patients and their family members were found for many elements of care. INTERPRETATION: Seriously ill patients and family members have defined the importance of various elements related to quality end-of-life care. The most important elements related to trust in the treating physician, avoidance of unwanted life support, effective communication, continuity of care and life completion. Variation in the perception of what matters the most indicates the need for customized or individualized approaches to providing end-of-life care.