768 research outputs found
The Determinants of Mortality
Mortality rates have fallen dramatically over time, starting in a few countries in the 18th century, and continuing to fall today. In just the past century, life expectancy has increased by over 30 years. At the same time, mortality rates remain much higher in poor countries, with a difference in life expectancy between rich and poor countries of also about 30 years. This difference persists despite the remarkable progress in health improvement in the last half century, at least until the HIV/AIDS pandemic. In both the time-series and the cross-section data, there is a strong correlation between income per capita and mortality rates, a correlation that also exists within countries, where richer, better-educated people live longer. We review the determinants of these patterns: over history, over countries, and across groups within countries. While there is no consensus about the causal mechanisms, we tentatively identify the application of scientific advance and technical progress (some of which is induced by income and facilitated by education) as the ultimate determinant of health. Such an explanation allows a consistent interpretation of the historical, cross-country, and within-country evidence. We downplay direct causal mechanisms running from income to health.
LOCATION DETERMINANTS OF MANUFACTURING INDUSTRY IN RURAL AREAS
Community/Rural/Urban Development,
The Determinants of Mortality
The pleasures of life are worth nothing if one is not alive to experience them. Through the twentieth century in the United States and other high-income countries, growth in real incomes was accompanied by a historically unprecedented decline in mortality rates that caused life expectancy at birth to grow by nearly 30 years. In the years just after World War II, life expectancy gaps between countries were falling across the world. Poor countries enjoyed rapid increases in life-expectancy through the 1970s, with the gains in some cases exceeding an additional year of life expectancy per year, though the HIV/AIDS epidemic and the transition in Russia and Eastern Europe have changed that situation. We investigate the determinants of the historical decline in mortality, of differences in mortality across countries, and of differences in mortality across groups within countries. A good theory of mortality should explain all of the facts we will outline. No such theory exists at present, but at the end of the paper we will sketch a tentative synthesis.Economic
Location determinants of manufacturing industry in rural areas
The spatial distribution of economic activity has been the subject of much theoretical study during the last 150 years. The two-state study which provides primary evidence for this article is, to the authors' knowledge, the first attempt to analyze statistically the determinants of industrial location in rural communities with an explicit objective of more enlightened public action at the local, state, and federal levels
Early onset airway obstruction in response to organic dust in the horse
Equine recurrent airway obstruction (RAO) has been used as a naturally occurring model of human asthma. However, it is unknown whether there is an early-phase response in RAO. The aim of this study was to determine whether exposure to organic dust induces immediate changes in lung function in RAO-affected horses, which could be mediated by airway mast cells. Six RAO-affected horses in remission and six control horses were challenged with hay-straw dust suspension by nebulization. Total respiratory resistance at 1 Hz, measured by forced oscillation, was increased from 0.62 +/- 0.09 cmH(2)O.l(-1).s (mean +/- SE) to 1.23 +/- 0.20 cmH(2)O.l(-1).s 15 min after nebulization in control horses (P = 0.023) but did not change significantly in the RAO group. Total respiratory reactance at 1 Hz (P = 0.005) was significantly lower in the control horses (-0.77 +/- 0.07 cmH(2)O.l(-1).s) than in the RAO group (-0.49 +/- 0.04 cmH(2)O.l(-1).s) 15 min after nebulization. Bronchoalveolar lavage fluid (BALF) histamine concentration was significantly elevated 10 and 20 min postnebulization in control horses but not in RAO horses. Minimum reactance at 1 Hz in the early postnebulization period significantly correlated with both prechallenge BALF mast cell numbers (r = -0.65, P = 0.02) and peak BALF histamine concentration postnebulization (r = -0.61, P = 0.04). In conclusion, RAO horses, unlike human asthmatic patients, do not exhibit an early-phase response. However, healthy control horses do demonstrate a mild but significant early (<20 min) phase response to inhaled organic dust. This response may serve to decrease the subsequent dose of dust inhaled and as such provide a protective mechanism, which may be compromised in RAO horses
Helical EndoStaples enhance endograft fixation in an experimental model using human cadaveric aortas
ObjectiveThis study evaluated the contribution of Aptus EndoStaples (Aptus Endosystems, Sunnyvale, Calif) in the proximal fixation of eight endografts used in the endovascular repair of abdominal aortic aneurysms (EVAR).MethodsNine human cadaveric aortas were exposed, left in situ, and transected to serve as fixation zones. The Zenith (Cook, Bloomington, Ind), Anaconda (Vascutek, Inchinnan, Scotland, UK), Endurant (Medtronic, Minneapolis, Minn), Excluder (W. L. Gore and Associates, Flagstaff, Ariz), Aptus (Aptus Endosystems), Aorfix (Lombard Medical, Didcot, UK), Talent (Medtronic), and AneuRx (Medtronic) stent grafts were proximally deployed and caudal displacement force (DF) was applied via a force gauge, recording the DF required to dislocate each device ≥20 mm from the infrarenal neck. Measurements were repeated after four and six EndoStaples were applied at the proximal fixation zone, as well as after a Dacron graft was sutured at the proximal neck in standard fashion. Finally, a silicone tube was used as a control fixation zone to test the DF of grafts with EndoStaples in a material that exceeded the integrity of a typical human cadaveric aorta and provided a consistent substrate to examine the differential effect of variable degrees of EndoStaple implantation using zero, two, four, and six EndoStaples.ResultsIn the cadaveric model, the mean DF required to dislocate the endografts without the application of EndoStaples was 19.73 ± 12.52 N; this increased to 49.72 ± 12.53 N (P < .0001) when four EndoStaples where applied and to 79.77 ± 28.04 N when six EndoStaples were applied (P = .003). The DF necessary to separate the conventionally hand-sutured Dacron graft from the aorta was 56 N. In the silicone tube model, the Aptus endograft without EndoStaples withstood 3.2 N of DF. The DF increased to 39 ± 3 N when two EndoStaples were added, to 71 ± 6 N when four were added, and to 98 ± 5 N when six were added. In eight of the 13 cadaver experiments conducted with four and six EndoStaples, the displacement occurred as a result of complete aortic transection proximal to the fixation site, indicating that aortic tissue integrity was the limiting factor in these experiments.ConclusionsThe fixation of eight different endografts was increased by a mean of 30 N with four Aptus EndoStaples and by a mean of 57 N with six EndoStaples in this model. Endostaples can increase endograft fixation to levels equivalent or superior to that of a hand-sewn anastomosis. The application of six EndoStaples results in aortic tissue failure above the fixation zone, demonstrating fixation strength that exceeds inherent aortic integrity in these cadavers.Clinical RelevanceThe proximal fixation of an endovascular device in the endovascular repair of abdominal aortic aneurysms (EVAR) is of crucial importance to avoid complications such as kinking, migration, and endoleak. This study represents the first attempt to quantify the effect of a new innovative device (Aptus EndoStaples) aimed to enhance endograft fixation. A cadaveric model, which resembles the forces applied onto the endovascular devices in vivo, was chosen to test the effect of the EndoStaples. The results suggest that endograft fixation is significantly better after the application of the EndoStaples, to an extent where it surpasses the inherent durability of the vessel wall
E-Type Delayed Fluorescence of a Phosphine-Supported Cu_2(μ-NAr_2)_2 Diamond Core: Harvesting Singlet and Triplet Excitons in OLEDs
A highly emissive bis(phosphine)diarylamido dinuclear copper(I) complex (quantum yield = 57%) was shown to exhibit E-type delayed fluorescence by variable temperature emission spectroscopy and photoluminescence decay measurement of doped vapor-deposited films. The lowest energy singlet and triplet excited states were assigned as charge transfer states on the basis of theoretical calculations and the small observed S_1−T_1 energy gap. Vapor-deposited OLEDs doped with the complex in the emissive layer gave a maximum external quantum efficiency of 16.1%, demonstrating that triplet excitons can be harvested very efficiently through the delayed fluorescence channel. The function of the emissive dopant in OLEDs was further probed by several physical methods, including electrically detected EPR, cyclic voltammetry, and photoluminescence in the presence of applied current
Recommended from our members
Interventions to increase referral to and uptake of Pulmonary Rehabilitation programmes for people with Chronic Obstructive Pulmonary Disease (COPD): A systematic review
Outcome of the pivotal study of the Aptus endovascular abdominal aortic aneurysms repair system
ObjectiveEndovascular treatment of abdominal aortic aneurysm (AAA) is associated with benefits over open surgery, yet limitations remain with current endovascular devices. This study was performed to assess outcomes of AAA repair with the Aptus endograft and EndoAnchors (Aptus Endosystems, Sunnyvale, Calif).MethodsThis prospective, multicenter, single-arm investigational device exemption trial was conducted at 25 sites in the United States. A total of 155 patients were enrolled in the trial (mean age, 73 ± 8 years; male, 93.5%; mean AAA diameter, 53.6 ± 7.9 mm). The Aptus endograft is a two-component system: a multilumen, modular endograft with two docking limbs (Aptus Endograft System) and the Heli-FX Aortic Securement System comprising an electronically controlled applier (Heli-FX Applier) with helical EndoAnchors provided in a cassette and a deflectable sheath (Heli-FX Guide) designed for delivery of the applier to the target location for EndoAnchor implantation. The main eligibility criteria included proximal neck length of ≥12 mm, diameter of 19 to 29 mm, and infrarenal angulation of ≤60 degrees. The primary safety end point was freedom from major adverse events at 30 days, and the primary effectiveness end point was successful aneurysm treatment at 12 months. Thrombus-related events (TRE) were defined as limb occlusion or thromboembolism from the endograft. Subjects were observed for a median of 4.2 years, with imaging end points analyzed by a core laboratory and adverse events adjudicated by a clinical events committee.ResultsAmong 155 enrolled subjects, 153 (98.7%) underwent successful implantation of the Aptus endograft and a median of five EndoAnchors; two subjects were converted to open surgical repair during the initial procedure. Overall, the primary safety and effectiveness end points were met in 98.1% and 97.4% of the subjects, respectively. Aneurysm-related mortality was 0.6%, with one postdischarge cardiac death 18 days after implantation. There were no AAA ruptures. There were no fractures of stents or EndoAnchors. There was one type I endoleak and one type III endoleak. Stent graft migration was noted in five subjects, none associated with sac enlargement, type I endoleak, or EndoAnchor dislocation from the endograft. AAA sac shrinkage of ≥5 mm at 1, 2, and 3 years was observed in 60.3%, 72.9%, and 81.7%, respectively. Sixty-one subjects (39.4%) experienced 113 TRE, associated with 80 reinterventions (in 58 subjects) unassociated with limb loss or death. A root cause analysis of TRE identified small, out-of-specification docking limbs with graft infolding and high local shear, resulting in thrombus formation within the endograft with subsequent distal embolization in some cases.ConclusionsEarly results of the Aptus endograft trial met its safety and effectiveness end points; however, a high rate of TRE was observed because of manufacturing discrepancies. The findings confirm a low rate of type I and type III endoleaks, migration, and non-TRE reintervention with a high rate of aneurysm sac regression during midterm follow-up
- …