To send content items to your account,
please confirm that you agree to abide by our usage policies.
If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your account.
Find out more about sending content to .
To send content items to your Kindle, first ensure email@example.com
is added to your Approved Personal Document E-mail List under your Personal Document Settings
on the Manage Your Content and Devices page of your Amazon account. Then enter the ‘name’ part
of your Kindle email address below.
Find out more about sending to your Kindle.
Note you can select to send to either the @free.kindle.com or @kindle.com variations.
‘@free.kindle.com’ emails are free but can only be sent to your device when it is connected to wi-fi.
‘@kindle.com’ emails can be delivered even when you are not connected to wi-fi, but note that service fees apply.
This research shows the development of alternative Cu-based materials for applications where enhanced thermal properties are desired. Cu/AlN composites were fabricated from mixtures of pure Cu and copper plated AlN-Cu composite powders. The ceramic phase was added in amounts of 10, 20 and 30 vol.% and the mixtures sintered by pulsed electric current sintering process (PECS). The results showed that the AlN particles are homogeneously distributed in the copper matrix and that the true contacts between hard particles are reduced because of the deposited copper on their surfaces, improving the connectivity of the matrix phase and bonding at the metal-ceramic interface. The relative density of the Cu/AlN composites was major than 97% in all cases. Thermal conductivity of the composites was high and decreased with the ceramic content from 359 to 194 W/mK, for 10 and 30% AlN, respectively. The coefficient of thermal expansion followed a lineal behavior with temperature and is also reduced with the ceramic content.
OBJECTIVES/SPECIFIC AIMS: The aims of this study are (1) to develop and characterize a novel nonhuman primate model of pneumococcal pneumonia that mimics human disease; and (2) determine whether Streptococcus pneumoniae can: (a) translocate to the heart, (b) cause adverse cardiac events, (c) induce cardiomyocyte death, and (d) lead to scar formation during severe pneumonia in baboons. METHODS/STUDY POPULATION: Six adult baboons (Papio cynocephalus) were surgically tethered to a monitoring system to continuously assess their heart rate, temperature, and electrocardiogram (ECG). A baseline transthoracic echocardiogram, 12-lead ECG, serum troponin-I levels, brain natriuretic peptide, and heart-type fatty acid binding protein (HFABP) levels were obtained before infection and at the end of the experiment to determine cardiovascular damage during pneumococcal pneumonia. Animals were challenged with 108 colony-forming units of S. pneumoniae in the right middle lobe using flexible bronchoscopy. Three baboons were rescued with ampicillin therapy (80 mg/kg/d) after the development of pneumonia. Cardiac damage was confirmed by examination of tissue sections using immunohistochemistry as well as electron and fluorescence microscopy. Western-blots and tissue staining were used to determine the presence of necroptosis (RIP3 and pMLKL) and apoptosis (Caspase-3) in the cardiac tissue. Cytokine and chemokine levels in the heart tissue were determined using Luminex technology. RESULTS/ANTICIPATED RESULTS: Four males (57%) and three (43%) females were challenged. The median age of all baboons was 11 (IQR, 10-19) years old, which corresponds to a middle-aged human. Infected baboons consistently developed severe pneumonia. All animals developed systemic inflammatory response syndrome with tachycardia, tachypnea, fever, and leukocytosis. Infection was characterized by initial leukocytosis followed by severe leukopenia on day 3 postinoculation. Non-specific ischemic alterations by ECG (ST segment and T-wave flattering) and in the premortem echocardiogram were observed. The median (IQR) levels of troponin I and HFABP at the end of the experiment were 3550 ng/mL (1717–5383) and 916.9 ng/mL (520.8–1323), respectively. Severe cardiomyopathy was observed using TEM and H&E stains in animals with severe pneumonia. Necroptosis was detected in cardiomyocytes of infected animals by the presence of pMLKL and RIP3 in cardiac tissues. Signs of cardiac remodeling indicated by disorganized collagen deposition was present in rescued animals but not in the other animals. DISCUSSION/SIGNIFICANCE OF IMPACT: We confirmed that baboons experience cardiac injury during severe pneumococcal pneumonia that is characterized by myocardial invasion, activation of necroptosis, and tissue remodeling in animals rescued by antimicrobial therapy. Cardiac damage by invading pneumococci may explain why adverse cardiac events that occur during and after pneumococcal pneumonia in adult human patients.
The care of patients with CHD remains a challenge in low- and middle-income countries. Their health systems have not been able to achieve consistently high performance in this field. The large volume of patients, manpower constraints, inconsistencies in the level and type of background training of the teams caring for this patient population, and the inadequate quality control systems are some of the barriers to achieving excellence of care. We describe three different international projects supporting the paediatric cardiac surgical and paediatric cardiac intensive care programmes in Latin America, Asia, and the Caribbean.
Core subset selection from collections hosted by seed banks, grow in importance as the number of accessions and genetic marker information rapidly increases. A data set of 20,526 single-nucleotide polymorphism (SNP) markers characterizing 7986 Mexican creole wheat landraces, was used to test 11 methods for core subset selection, through optimization criteria containing average genetic distance and genetic diversity. Allele richness was used as an additional criterion to qualify the generated core subsets. Three replications with random samples of 1500 SNP loci, each comprising a maximum of 3000 alleles, were used to perform the method evaluations through four different objective functions. The LR greedy search (LR) and LR with random first pair (LRSemi) were consistently best across all assays for maximizing the objective functions, and they performed well even for criteria not included in those functions. The Tukey's HSD (honest significant difference) multiple comparisons grouped those methods together with the sequential forward selection (SFS) and SFS with random first pair (SFSSemi) strategies as the top set of approaches. All of them are simple heuristic maximization algorithms, and outperformed two more sophisticated optimization approaches: parallel mixed replica exchange and replica exchange Monte Carlo. For their efficiency to optimize the objective functions and computing speed, the LRSemi and SFSSemi methods demonstrated to be good alternatives for core subset selection from large collections of highly homozygous accessions characterized by many biallelic markers.
To assess the consumption of ultra-processed foods and analyse its association with the content of added sugars in the Chilean diet.
Cross-sectional study of national dietary data obtained through 24 h recalls and classified into food groups according to the extent and purpose of food processing (NOVA classification).
A probabilistic sample of 4920 individuals (aged 2 years or above) studied in 2010 by a national dietary survey (Encuesta Nacional de Consumo Alimentario).
Ultra-processed foods represented 28·6 (se 0·5) % of total energy intake and 58·6 (se 0·9) % of added sugars intake. The mean percentage of energy from added sugars increased from 7·7 (se 0·3) to 19·7 (se 0·5) % across quintiles of the dietary share of ultra-processed foods. After adjusting for several potential sociodemographic confounders, a 5 percentage point increase in the dietary share of ultra-processed foods determined a 1 percentage point increase in the dietary content of added sugars. Individuals in the highest quintile were three times more likely (OR=2·9; 95 % CI 2·4, 3·4) to exceed the 10 % upper limit for added sugars recommended by the WHO compared with those in the lowest quintile, after adjusting for sociodemographic variables. This association was strongest among individuals aged 2–19 years (OR=3·9; 95 % CI 2·7, 5·9).
In Chile, ultra-processed foods are important contributors to total energy intake and to the consumption of added sugars. Actions aimed at limiting consumption of ultra-processed foods are being implemented as effective ways to achieve WHO dietary recommendations to limit added sugars and processed foods, especially for children and adolescents.
Ni-Co/Al2O3 composites with alumina particles below 0.53 µm in size were electrochemically deposited on carbon steel AISI-O1 substrates. The influence of current density (2, 3, 4 and 5 mA/cm2) on the microstructure and adhesion behavior was investigated. It was found that the micro-hardness of the surface increased in 90% with respect to the plain substrate. SEM examination revealed an increased thickness from 3.7 to 10.7 µm at current density of 2 and 5 mA/cm2, respectively. The Co/Ni weight ratio in the coatings was determined by atomic absorption spectroscopy (AAS); the content of Co and Ni at 2 mA/cm2 were 42.4 %Co and 57.6 %Ni, while at 5 mA/cm2 were 44.5%Co and 55.5%Ni. The adhesion of the coatings was evaluated qualitatively according to the VDI 3198 norm; in all the cases, the adhesion was more than acceptable since no cracks or detachments were observed in the periphery of the marks. Details on the synthesis and properties of the Ni-Co/Al2O3 composite coatings are presented together with the excellent properties they show despite of their thin thickness.
In the present work we have computed the physical parameters and chemical abundances for 45 planetary nebulae (PN) in the Large Magellanic Cloud (LMC) using the photoionization code CLOUDY, developed by Ferland (1993). CLOUDY is used as a subroutine in the code DIANA, developed by Elizalde & Steiner (1996), which minimises indices that measures the difference between the calculated and real nebula.
Chladni figures are formed when particles scattered across a plate move due to an external harmonic force resonating with one of the natural frequencies of the plate. Chladni figures are precisely the nodal set of the vibrational mode corresponding to the frequency resonating with the external force. We propose a plausible model for the movement of the particles that explains the formation of Chladni figures in terms of the stochastic stability of the equilibrium solutions of stochastic differential equations.
The objective of the study was to design and evaluate a pilot programme aimed at promoting the active ageing of older adults at the Mexican Institute of Social Security. The study was conducted in three stages: (a) design; (b) implementation; and (c) before–after evaluation through analysis of changes in functional status, occupational functioning and health-related quality of life. To overcome the limitations of the study design, we evaluated the effect of 80 per cent adherence to the programme on the outcome variables using the generalised linear regression models (GLM). Two hundred and thirty-nine older adults agreed to participate, of whom 65 per cent completed the programme. Most were women; the average age was 77 years. Adherence to the programme was higher than 75 per cent for the group who completed active ageing services and less than 60 per cent for the drop-out group. Overall, 46 per cent of older adults reached an adherence level of 80 per cent or higher. Adherence was significantly associated with improved quality of life total score (coefficient 2.7, p<0.0001) and occupational functioning total score (coefficient 2.2, p<0.0001). Participation of older adults in an active ageing programme may improve their health-related quality of life and occupational functioning. It is necessary to identify the potential barriers and to implement strategies to improve the recruitment and retention rates during the intervention.
We report our main results on the development of un-cooled microbolometers based on hydrogenated amorphous Germanium-Silicon (a-GexSiy:H) thermo-sensing films deposited by Plasma Enhanced Chemical Vapor Deposition (PECVD). Our research has been conducted to improve both, the structure of the devices (pixels) and the performance characteristics of the amorphous Germanium-Silicon thermosensing films.
Our motivation is to produce microbolometers with much better performance characteristics (larger thermal coefficient of resistance, larger conductivity and better stability) than those available in commercial microbolometer arrays, based on boron doped hydrogenated amorphous silicon (a-Si:H,B).
As part of our latest research, we also report the study of what we believe is the next generation of thermosensing films based on Silicon and Geranium amorphous films with embedded nanocrystals in the amorphous matrix (polymorphous films). Those materials have several advantages over amorphous, as a lower defect density, better stability and better transport properties.
The study objective was to examine the association, among older persons with cutaneous melanoma, between areal socioeconomic status (SES) and receiving chemotherapy. SEER-Medicare-linked database (1,239 white men and women aged ≥ 66, with invasive melanoma [regional and distant stages]; 1991–1999) was used. SES was measured by census tract poverty level (average of 1990 and 2000 Census data). Covariates were sociodemographics, tumor characteristics, and comorbidity index. Residing in poorer SES areas was associated with a lower likelihood for receiving chemotherapy among patients in the overall sample (adjusted odds ratios = OR 0.97, 95% confidence interval = CI 0.95–0.99), and those with regional stage at diagnosis (OR 0.97, 95% CI 0.94–0.98). These findings reflect socioeconomic disparities in chemotherapy use for melanoma among older white patients in the United States.
Ni-P and Ni-P-Al2O3 composite coatings are obtained by electroless plating on steel substrates. Alumina particles with an average particle size of 5 microns are added to the bath in loads of 5, 10, 15 and 20g/L. It is found a maximum retention of 18.2 vol.% Al2O3 for a ceramic load of 10g/L. The composition of the binary Ni-P deposits is 9.3 wt.% P and the balance nickel. The addition of ceramics to the electroless solution induces a reduction of phosphorous content to 9.0, 8.3, 7.9 and 7.3%, respectively. The deposited coatings are heat-treated in the temperature range between 100 and 500°C and holding times from 30 to 300 minutes. A maximum hardness of 1600 HV0.1 is obtained for composite coatings containing 18.2 vol.% Al2O3 treated at 400 °C/1h. The uniform distribution of ceramics and precipitation of fine Ni3P and Ni12P5 precipitates are responsible of the hardening of the nickel matrix.
Phytosterols (PS) are recommended to reduce LDL-cholesterol. However, the influence of cholesterol and fat intake on the lipid-lowering effect of PS in mildly hypercholesterolaemia is unclear. Thus, the aim of the present study was to evaluate whether the efficacy of PS is related to the composition of saturated fat and dietary cholesterol intake. Additionally, serum carotenoid content was analysed to evaluate to what extent it was undermined by PS. This was a 3-month randomised, parallel trial with a three-arm design. Patients were divided into three groups: healthy diet (n 24), healthy diet+PS (n 31) and free diet+PS (n 29), receiving 2 g/d of PS. Healthy and free diets were characterised by a daily ingestion of 6·8 % of saturated fat and 194·4 mg of cholesterol and 12·7 % of saturated fat and 268·1 mg of cholesterol, respectively. After PS therapy, patients receiving the healthy diet+PS or a free diet+PS exhibited a similar reduction in total cholesterol (6·7 and 5·5 %), LDL-cholesterol (9·6 and 7·0 %), non-HDL-cholesterol (12·2 and 8·9 %) and apo B-100/apo A-I ratio (11·5 and 11·6 %), respectively. In patients following the healthy diet, (β-carotene concentration rose by 26·9 %, whereas the β-carotene and lycopene levels dropped by 21·0 and 22·8 % in the group receiving the free diet+PS, respectively. No change was observed in carotenoid levels in healthy diet+PS group. In conclusion, the efficacy of PS in relation to lipoprotein profile is not influenced by saturated fat or dietary cholesterol intake, which confirms the positive effect of healthy diet therapy in improving the negative effects that PS exert on carotenoid levels.
Using the method of canonical group quantization, we construct the angular momentum operators associated to configuration spaces with the topology of (i) a sphere and (ii) a projective plane. In the first case, the angular momentum operators derived this way are the quantum version of Poincaré's vector, i.e., the physically correct angular momentum operators for an electron coupled to the field of a magnetic monopole. In the second case, the operators one obtains represent the angular momentum operators of a system of two indistinguishable spin zero quantum particles in three spatial dimensions. The relevance of the proposed formalism for the progress in our understanding of the spin–statistics connection in nonrelativistic quantum mechanics is discussed.
The connection between the spin of quantum particles and the statistics they obey is a remarkable example of a simply stated physical fact without the recognition of which many physical phenomena (ranging from the stability of matter and the electronic configuration of atoms to Bose–Einstein condensation and superconductivity) would not have an explanation. Nevertheless, the simplicity of the assertion “integer spin particles obey Bose statistics, and half-integer spin particles obey Fermi statistics” stands in bold contrast to its intricate physical origin. Indeed, Pauli's proof of the spin–statistics theorem [Pau40] (improving on earlier work by Fierz [Fie39]), showed that the spin–statistics connection was deeply rooted in relativistic quantum field theory. The path to a rigorous proof of this theorem (from the mathematical point of view) was a long one and involved the efforts of many people (see, e.g., the book by Duck and Sudarshan [DS98b]).
Subcutaneous hydration, or hypodermoclysis (HDC), is a very simple technique that should be practised more often by doctors and nurses who care for older patients. It involves less discomfort, generates less cost and has fewer adverse effects than the intravenous route and may reduce the need for admission to the emergency department. The main indication is the management of mild to moderate dehydration, and prevention of dehydration in patients who are intolerant of oral intake. It should not be administered in situations of severe dehydration, in emergency situations, or in patients with fluid overload. Isotonic or hypotonic solutions must be used with appropriate electrolytes. Certain medicines can be given simultaneously by HDC and this may be especially valuable in palliative care settings. In most cases there is no need to add hyaluronidase.
The objectives of this study were to assess the prevalence of fear of falling (FOF) among patients over age 60 with dizziness, falls, or syncope; and to analyze risk factors associated with FOF, including data from the tilt table test. This study included 200 older patients referred to a geriatric outpatient clinic specializing in dizziness, falls, and syncope. The primary outcome measure was the proportion of patients who experienced FOF (yes vs. no) and whether FOF restricted leaving home alone or performing activities of daily living. FOF occurred in 50 per cent of patients in this population. Among these, 44 per cent gave up going out alone and 10 per cent stopped doing basic activities of daily living. Beyond age 75, FOF was associated with recurrent dizziness, depression, and symptoms on standing, but not prior falls.
We explore the association between a neighbourhood’s ethnic composition and the foods and nutrients consumed by Mexican-Americans.
Cross-sectional survey of a large national sample, from the Third National Health and Nutrition Examination Survey (1988–94), was linked to the 1990 Census. The outcomes were food frequencies and serum levels of micronutrients. The variable of interest was percentage of Mexican-Americans at the census tract level.
A total of 5306 Mexican-American men and women aged 17–90 years.
Increased percentage of Mexican-Americans at the census tract level was associated with less consumption of fruits, carrots, spinach/greens and broccoli and with lower serum levels of Se, lycopene, α-carotene, vitamin C and folate. By contrast, increased percentage of Mexican-Americans at the census tract level was associated with more consumption of corn, tomatoes, hot red chilli peppers and legumes such as beans, lentils or chickpeas.
An increased percentage of Mexican-Americans at the census tract level was associated with less consumption of selective foods (e.g. some fruits, broccoli) and low levels of serum Se or vitamin C, but it was associated with more consumption of other foods (e.g. legumes, tomatoes, corn products) that may have positive effects on health in this population.
This paper is devoted to the numerical solution of stationary
laminar Bingham fluids by path-following methods. By using duality theory, a
system that characterizes the solution of the original problem is derived.
Since this system is ill-posed, a family of regularized problems is obtained
and the convergence of the regularized solutions to the original one is proved.
For the update of the regularization parameter, a path-following method is
investigated. Based on the differentiability properties of the path, a model of
the value functional and a correspondent algorithm are constructed. For the
solution of the systems obtained in each path-following iteration a semismooth
Newton method is proposed. Numerical experiments are performed in order to
investigate the behavior and efficiency of the method, and a comparison with a
penalty-Newton-Uzawa-conjugate gradient method, proposed in [Dean et al., J. Non-Newtonian Fluid Mech.142 (2007) 36–62], is
Oocytes undergo numerous biochemical and morphological changes during their development from preantral to preovulatory phases. In vitro studies have suggested several compounds that might induce oocyte maturation. Heparin is a natural component of ooplasm, follicular fluid and uterine fluid and previous studies indicated that it might act as a chromatin maturation factor in bovine oocytes. We tested this hypothesis in vitro by timing germinal vesicle breakdown (GVBD) and first polar body (PB) formation without any other natural or introduced factors that might influence the rate of oocyte maturation. We also determined if these oocytes could be fertilized.
Bovine oocytes were incubated in a salt medium and TCM 199 supplemented with different concentrations of heparin for 24 h at 37.5 °C in a humidified atmosphere of 5% CO2. With 1.0 and 6.5 mg/ml heparin, the time of GVBD was reduced from 4.7 ± 1.1 h to about 1.5 h and the time of first PB formation was reduced from 22.0 ± 1.1 h to 9.0–11.0 h in salt medium. In TCM 199, only 6.5 mg/ml heparin significantly reduced the time of PB formation. In both incubation media, 1.0 and 6.5 mg/ml heparin induced GVBD, extrusion of the first PB and formation of the metaphase II nucleus. Moreover, heparin did not interfere with the fertilization of oocytes matured in TCM 199. Based on the results, we propose that heparin plays an important role in the rearrangement of the oocyte chromatin and acts as an oocyte maturation factor.