Aims/hypothesis The aim of the study was to examine the determinants of oral glucose tolerance in 602 persons with impaired glucose tolerance (IGT) who participated in the Actos Now for Prevention of ...Diabetes (ACT NOW) study. Methods In addition to the 602 IGT participants, 115 persons with normal glucose tolerance (NGT) and 50 with impaired fasting glucose (IFG) were identified during screening and included in this analysis. Insulin secretion and insulin sensitivity indices were derived from plasma glucose and insulin during an OGTT. The acute insulin response (AIR) (0-10 min) and insulin sensitivity (SI) were measured with the frequently sampled intravenous glucose tolerance test (FSIVGTT) in a subset of participants. Results At baseline, fasting plasma glucose, 2 h postprandial glucose (OGTT) and HbA₁c were 5.8 ± 0.02 mmol/l, 10.5 ± 0.05 mmol/l and 5.5 ± 0.04%, respectively, in participants with IGT. Participants with IGT were characterised by defects in early (∆I ₀₋₃₀/∆G ₀₋₃₀ × Matsuda index, where ∆I is change in insulin in the first 30 min and ∆G is change in glucose in the first 30 min) and total (∆I₀₋₁₂₀/∆G₀₋₁₂₀ × Matsuda index) insulin secretion and in insulin sensitivity (Matsuda index and SI). Participants with IGT in whom 2 h plasma glucose was 7.8-8.3 mmol/l had a 63% decrease in the insulin secretion/insulin resistance (disposition) index vs participants with NGT and this defect worsened progressively as 2 h plasma glucose rose to 8.9-9.94 mmol/l (by 73%) and 10.0-11.05 mmol/l (by 80%). The Matsuda insulin sensitivity index was reduced by 40% in IGT compared with NGT (p < 0.005). In multivariate analysis, beta cell function was the primary determinant of glucose AUC during OGTT, explaining 62% of the variance. Conclusion Our results strongly suggest that progressive beta cell failure is the main determinant of progression of NGT to IGT.
We report on high resolution laser ionization time-of-flight mass spectroscopy (LITOF-MS) measurements of lead borosilicate and sodium-doped lead borosilicate glasses. This technique permits the ...observation of intermediate range mesounits, and provides new insights into the glass network structure. In lead borosilicates we observed strong mixing of borate and silicate groupings, a likely absence of diborate units, and the formation of boroxol rings with one lead cation (PbB
3O
6) at borate-rich compositions. The spectra also suggest the growth of a limited lead oxide subnetwork at high Pb contents. In the sodium-doped glasses we see a preference of the sodium for boron units, and the simultaneous appearance of sodium-containing silicate units between 10 and 24 mol% Na
2O, though borate association remains predominant. The reedmergnerite unit (BSi
4O
10) is seen in very small amounts in both glass families.
A high resolution, laser desorption time of flight mass spectrometer (LITOF-MS) was used to study lead borate glasses and crystals. This technique provides valuable information about glass structure, ...including the superstructural network units. Several structural units were identified and we found evidence of a lead substructure beginning to form in the glass with increased lead content.
Extracorporeal membrane oxygenation-related complications are potentially catastrophic if not addressed quickly. Because complications are rare, high-fidelity simulation is recommended as part of the ...training regimen for extracorporeal membrane oxygenation specialists. We hypothesized that the use of standardized checklists would improve team performance during simulated extracorporeal membrane oxygenation emergencies.
Randomized simulation-based trial.
A quaternary-care academic hospital with a regional extracorporeal membrane oxygenation referral program.
Extracorporeal membrane oxygenation specialists and other healthcare providers.
We designed six read-do checklists for use during extracorporeal membrane oxygenation emergencies using a modified Delphi process. Teams of two to three providers were randomized to receive the checklists or not. All teams then completed four simulated extracorporeal membrane oxygenation emergencies.
Simulation sessions were video-recorded, and the number of critical tasks performed and time-to-completion were compared between groups. A survey instrument was administered before and after simulations to assess participants' attitudes toward the simulations and checklists. We recruited 36 subjects from a single institution, randomly assigned to 15 groups. The groups with checklists completed more critical tasks than participants in the control groups (90% vs 75%; p < 0.001). The groups with checklists performed a higher proportion of both nontechnical tasks (71% vs 44%; p < 0.001) and extracorporeal membrane oxygenation-specific technical tasks (94% vs 86%; p < 0.001). Both groups reported an increase in reported self-efficacy after the simulations (p = 0.003). After adjusting for multiple comparisons, none of the time-to-completion measures achieved statistical significance.
The use of checklists resulted in better team performance during simulated extracorporeal membrane oxygenation emergencies. As extracorporeal membrane oxygenation use continues to expand, checklists may be an attractive low-cost intervention for centers looking to reduce errors and improve response to crisis situations.
Medical training spans nearly a decade, during which many physicians traditionally begin families. Although childrearing responsibilities are shared by men and women in the modern era, differences in ...time allocated to child care by sex and its potential impact on residency experience merit discussion.
An anonymous, voluntary, 102-item survey was distributed to 540 current radiation oncology residents and 2014 graduates that asked about marital and parental status, pregnancy during residency, publication productivity, career aspirations, and experiences working with pregnant co-residents. Respondents with children were asked about childcare arrangements, and women who were pregnant during residency were asked about radiation safety, maternity leave, and breastfeeding experiences.
A total of 190 respondents completed the survey, 107 men (56.3%) and 84 women (43.7%). Ninety-seven respondents (51.1%) were parents, and 84 (44.2%) reported a pregnancy during residency. Respondents with children more often were male (65% vs 47.3%; P=.014), in a higher level of training (79.3% vs 54.8% were PGY4 or higher; P=.001), were older (median age of 32, interquartile range IQR:31-35 vs age 30 IQR: 29-33; P<.001), had a PhD (33% vs 19.3%, respectively; P=.033), were married (99% vs 43%, respectively; P<.001), and had a partner who did not work (24.7% vs 1.9%, respectively; <.001). There were no differences in the number of manuscripts published or the number of residents who expressed likelihood of pursing an academic career by parental status. Among parents, men more frequently had partners who did not work (38.1% vs 0%, respectively; P<.001) and reported that their partner performed a greater percentage of childcare duties (70% IQR: 60%-80% vs 35% IQR: 20%-50%, respectively; P<.001).
Pregnancy and parenthood are common during residency. Female residents are frequently responsible for more childcare duties than males but have similar research productivity and career aspirations. Further investigation is critical to elucidate gender disparities in parenthood and career development.
Final design of the C-SPECT-I lab-prototype Chang, W.; Rozler, M.; Sankar, P. ...
2015 IEEE Nuclear Science Symposium and Medical Imaging Conference (NSS/MIC),
2015-Oct.
Conference Proceeding
Improving system sensitivity without sacrificing imaging resolution is the key to improving the performance of cardiac SPECT imaging. This sensitivity increase is needed for reducing imaging time, or ...radiation dose, and/or motion artifacts for clinical imaging studies, as well as for exploration of new clinical applications. In addition, attenuation correction is necessary to yield quantitative information - the long-standing goal of SPECT imaging. These goals can be met by C-SPECT - our proposed dedicated cardiac platform for SPECT imaging. High sensitivity is accomplished by C-SPECT's optimized detection and system geometry, which wraps around patients' left-front thorax and provides the highest practical geometric efficiency for any spatial resolution of collimation. The first generation of C-SPECT platform - C-SPECT-I - is the simplified version that uses parallel axial collimation instead of the ultimate 3D converging collimation. In the presented final design, C-SPECT-I's variable collimation system provides 5 slit-arcs, for transaxial collimation to match with 2 slat-stacks, for axial collimation, to provide high system sensitivity and a large number of simultaneous projections. This lab-prototype will provide a system sensitivity that is 2.5 times that of a dual-head SPECT system for heart imaging with the same hardware resolution at the center of the imaging volume as well as unprecedented functionality and operational versatility.
Petroleum System Modelling (PSM) is a method which reproduces the burial history of sedimentary basins, together with rock properties, thermal and stress state, fluid flow and chemical transfers. The ...Vaca-Muerta Formation (Fm) in the Neuquén foreland basin, Argentina, presents exceptionally high overpressure despite the latest erosional history coeval with the current basin shortening. PSM currently accounts for vertical compaction laws only, which are not sufficient to match the observed pore pressure while keeping permeability values realistic. It also prevents to discuss the relationships between natural fracturing and the basin hydrodynamic. To assess these phenomena, a code coupling a PSM and a geomechanical simulator is used, in which we consider a 3D poro-elastoplastic geomechanical framework that accounts for both burial and tectonic compaction. Using this coupled approach, we calibrate porosity and pore pressure in a 3D geological model of the Neuquén basin using successive tectonic shortening phases related to the Andean subduction. Compared to PSM results using similar parameters, this study quantifies how much Andean tectonic deformation influenced pore pressure evolution in the basin. It shows that Late Miocene to recent tectonic could explain most of the overpressure observed in the Vaca-Muerta Fm. A shear-induced fracturing index provided by the constitutive model suggests that fracturing in the Vaca-Muerta Fm is very likely to occur during one of the main Andean deformation phases. The work suggests that pore pressure prediction in regions that have been subjected to lateral tectonic loading should be handled considering a 3D geomechanical approach. Using the Neuquén basin as an example, the present study discusses the impact of tectonic in pore pressure evolution, and its role in natural fluid migration in sedimentary basins subjected to tectonic deformation.
•We couple a PSM and a geomechanical code to model tectonic shortening in the poro-mechanichal evolution of the Neuquén basin.•Miocene to recent Andean tectonics can explain most of the present-day fluid overpressure in the Vaca-Muerta Fm.•The Vaca-Muerta Fm seal fracturing occurs simultaneously to the Andean deformation phases.
Background
Myocardial perfusion imaging is commonly performed using SPECT, where both general‐purpose and dedicated scanners are available. A limitation with general‐purpose systems has been the ...inability to image dynamically since different projections are obtained far apart in time due to scanner rotation. Dedicated systems can have this capability since they acquire completely sampled projections (i.e., those with enough angular views for reconstruction) with short time frames. C‐SPECT, does not need any scanner or patient motion to obtain complete projections, allowing fast dynamics. When imaging fast dynamics, the optimal collimator settings are not necessarily the same as for static imaging, where longer acquisitions can be utilized. Thus, C‐SPECT offers adaptive collimation in the transverse and axial directions.
Purpose
The performance of adaptation in the axial direction was characterized herein.
Methods
The ratio of the resolution metric in high‐sensitivity mode to that in the high‐resolution mode, termed resolution boost factor, was determined. Analogously, the sensitivity boost factor was also determined. Comparisons were made with theory and simulations.
Results
The boost factors for resolution and sensitivity, averaged over the 14 modules of the system, were determined to be 1.72 and 1.75, respectively.
Conclusions
The boost factors, which ideally would be two, were between 10% and 15% below optimal values and tracked each other, suggesting mechanical challenges in the apparatus, such as incomplete closure of adjacent slats, but show reasonably successful adaptation between modes.
Infertility and mortality Stentz, Natalie C.; Koelper, Nathanael; Barnhart, Kurt T. ...
American journal of obstetrics and gynecology,
March 2020, 2020-03-00, 20200301, Letnik:
222, Številka:
3
Journal Article
Recenzirano
Infertility affects 1 in 10 American reproductive-age women. The impact of this disease beyond the reproductive years is largely unknown.
The objective of the study was to determine the association ...of infertility history with all-cause and cause-specific mortality.
This secondary analysis of a multicenter randomized clinical trial included 75,784 women (aged 55–74 years) prospectively enrolled in the Prostate, Lung, Colorectal, and Ovarian cancer-screening trial from 1992 through 2001 and followed up a minimum of 10 years for health-related outcomes and death (856,935 person-years). We examined the association of infertility history (inability to conceive for 1 year or greater) of all-cause and cause-specific mortality using disease risk score–adjusted Cox-proportional hazard regression models.
Infertile women had a 10% increased risk of death (from any cause) during the study period compared with the unexposed (adjusted hazard risk, 1.10, 95% confidence interval, 1.02–1.18, P = .010). This effect was predominantly noted in women at an otherwise low risk of mortality who had a 26% increased risk of death (adjusted hazard risk, 1.26, 95% confidence interval, 1.12–1.42, P < .001). No differences in cardiovascular or diabetic mortality were noted. The risk of cancer death at any time over the study period was increased by 23% in infertile women compared with the unexposed (adjusted hazard risk, 1.23, 95% confidence interval, 1.10–1.37, P < .001). This effect was predominantly noted in women at an otherwise low risk of cancer mortality who had a 47% increased risk of cancer death (adjusted hazard risk, 1.47, 95% confidence interval, 1.25–1.73, P < .001). While no differences are seen in the risk of death from endometrial or ovarian cancer, the risk of death from breast cancer was more than doubled in infertile women at an otherwise low risk of breast cancer death compared with the unexposed (adjusted hazard risk, 2.64, 95% confidence interval, 1.71–4.08, P < .001).
Infertility is a harbinger of future morbidity and mortality. Infertile women are at an increased risk of all-cause and cancer-related mortality. Consideration of infertility history in health care maintenance presents an opportunity for screening and early intervention for long-term health outcomes.
PDF
