Search

Objective: To determine the influence of TAP1 and TAP2 alleles in northwestern Colombian patients with systemic lupus erythematosus (SLE). Methods: Unselected patients with SLE (n=140) and controls (n=120) matched for [...]

Rheumatoid arthritis (RA) is the most common chronic inflammatory disease, affecting about 1% of the white population, particularly female patients, and has considerable physical, psychological, and social repercussions. (1) In [...]

We have studied the influence of the thermal treatment on the stress dependence of the switching field during the devitrification of amorphous Fe73.5Cu1Nb3Si11.5B11 microwires. The non-destructive test (NDT) method based on the magnetization reversal of ferromagnetic materials is sensible to changes in microstructural characteristics and the stress state of the material. The stress dependence has been explained considering the magnetoelastic contribution to the switching mechanism which is modified applying the tensile stresses and changing the magnetostriction constant and strength of the internal stresses distribution through thermal treatments. We show that by properly setting a frequency during the measurement and adequate treatment of the sample, it is possible to vary the sensitivity, magnitude and stress dependence of the sample. Keywords: Magnetic bistability, glass-coated microwires, switching field, stress sensor

One presents in this work the study of the interaction between a focused laser beam and Si nanowires (NWs). The NWs heating induced by the laser beam is studied by solving the heat transfer equation by finite element methods (FEM). This analysis permits to establish the temperature distribution inside the NW when it is excited by the laser beam. The overheating is dependent on the dimensions of the NW, both the diameter and the length. When performing optical characterisation of NWs using focused laser beams, one has to consider the temperature increase introduced by the laser beam. An important issue concerns the fact that the NW’s diameter has subwavelength dimensions, and is also smaller than the focused laser beam. The analysis of the thermal behaviour of the NWs under the excitation with the laser beam permits the interpretation of the Raman spectrum of Si NWs. It is demonstrated that the temperature increase induced by the laser beam plays a major role in shaping the Raman spectrum of Si NWs.

This laboratory work presents a study of the effect of ultrafine grinding on the gold recovery of a highly refractory gold concentrate. The particle size of the concentrate was P80= 46 µm and the main species present were quartz (28.58%), dolomite (25.63%), pyrite (20.93%), arsenopyrite (15.39%) and 112 g/t gold. After optimizing hydrated lime and lead nitrate additions, standard cyanidation with 1% NaCN, pH = 12.3, 25% S/L permits to recover only 9.4% of the gold. Different particle sizes were submitted to cyanidation. When the concentrate was ground to ultrafine sizes (P80= 4.6 µm), the gold recovery for the same cyanidation conditions increased to 67%, with cyanide consumption of 66.7 kg NaCN/t. Additional tests were performed in order to reduce the cyanide consumption. The reduction of the cyanide concentration in the leaching solution from 1 to 0.5% and the addition of 100 g Pb(NO3)2/t allowed the reduction of the cyanide consumption to 27.6 kg NaCN/t (58% reduction), while maintaining the same gold recovery of 67%. The remaining gold could be present as very fine inclusions or in solid solution in the matrix.

Monitoring water level changes is necessary to manage, conserve and restore natural, and anthropogenic lake systems. However, the in‐situ monitoring of lake systems is unfeasible due to limitations of costs and access. Furthermore, current remote sensing methods are restricted to large lakes and low spatial resolutions. We develop a novel approach using subsequential pixel‐wise observations of the Sentinel‐1B sensor based on interferometric synthetic aperture radar to detect water level changes in small lakes. We used 24 small ungauged lakes of the Cajas Massif lake system in Ecuador for development and validation. We found Differential Interferometric Synthetic Aperture Radar (DInSAR)‐derived water level changes across lakes to be consistent with precipitation, capturing the peak of the wet seasons. Furthermore, accumulated water level changes could be explained by differences in lake area among lakes. Although with limitations, this study shows the underutilized potential of DInSAR to understand water level changes in small lakes with current radar data availability. Lakes are essential elements of the hydrological cycle, and changes in lakes water availability affect their aquatic and terrestrial ecosystems and their associated watersheds. Monitoring water level changes is necessary to manage lake systems worldwide; however, monitoring remote and small lakes is unfeasible due to limitations of costs and access. We develop a novel approach that combines satellite remote sensing radar imagery to detect water level changes in small lakes. We used 24 small and high‐altitude unmonitored lakes in Ecuador for development and validation. We found the water level changes across lakes to be consistent with precipitation in the region. Furthermore, accumulated water level changes could be explained by differences in lake area among lakes. Our methodology underpins the underutilized potential of satellite radar observations to understand water level changes in small lakes. It also has considerable potential for the near real‐time monitoring of lake systems worldwide from space observations. We demonstrated the utility of synthetic aperture radar interferometry to track water level changes in small ungauged lakes simultaneouslyRegional precipitation and area of lakes conditioned the spatiotemporal patterns of changes in water levelIrregular topography and surrounding elements on the lake shores were crucial for the use of radar interferometry We demonstrated the utility of synthetic aperture radar interferometry to track water level changes in small ungauged lakes simultaneously Regional precipitation and area of lakes conditioned the spatiotemporal patterns of changes in water level Irregular topography and surrounding elements on the lake shores were crucial for the use of radar interferometry

ObjectiveData concerning the immunogenetic characteristics of primary Sjogren's syndrome (SS) in Latin-Americans are scarce. A research project centered on primary SS in Colombians was initiated in January 1996 to better define these characteristics.MethodsTAP, HLA, IL-10, and microsatellites on 6p21.3 genotyping was performed by polymerase chain reaction techniques. Immunohistochemistry for Bcl-2 antagonist/killer (Bak) was performed. Autoantibodies and serum level of cytokines (IL-10, TNF-@a, IFN-@c, IL-4, and IL-12p70) were determined by enzyme-linked immunosorbent assay.ResultsThe HLA-DRB1*0301-DQB1*0201 haplotype was associated with disease (OR = 4.3, 95% CI: 1.6 to 11.9, P = 0.002), with a more severe histopathologic picture, and with the presence of anti-Ro and anti-La antibodies. D6S439 microsatellite polymorphism was associated with primary SS in an HLA-independent manner. The most likely gene related to the D6S439 chromosomal location appears to be BAK-1, which codes for Bak protein, expressed in salivary gland's infiltrate from patients with primary SS but not in controls. IL-10 and IFN-@c concentrations were significantly higher in patients than in controls (P < 0.01). IL-10 correlated with titers of IgA rheumatoid factor, anti-Ro, and anti-La antibodies, and with the severity of lymphocytic infiltrate (r > 0.3, P < 0.04). Patients who produced high IL-10 levels had significantly more episodes of cutaneous vasculitis and a higher proportion the IL-10.G9 allele.ConclusionsThe HLA-DRB1*0301-DQB1*0201 haplotype and IL-10 participate in the histopathological progression of SS, autoantibody production, and clinical manifestations. Bak protein and its gene polymorphism may participate in the pathology and susceptibility of disease. HLA and cytokine (IL-10 and IFN-@c) manipulation may be helpful in treating patients with primary SS.

Sulfasalazine is an efficient treatment for rheumatoid arthritis (RA), but its mode of action is not known. In RA, a correlation has been demonstrated between disease activity and the secretion of immunoglobulin A (IgA) by peripheral blood lymphocytes (PBL) in culture. Furthermore, the IgA-producing cells of the peripheral blood have been shown to originate from the mucous-associate lymphoid tissue (MALT). We studied the variations in the total IgA concentration in the serum of RA patients, and the secretion of IgA by PBL after 7 days culture in vitro, before and after treatment with sulfasalazine. A significant decrease in the serum IgA concentraton was obtained, but there was no modification of the spontaneous increase in the in vitro IgA synthesis by circulating monoclear cells. Our results suggested that the decrease in serum IgA concentration after treatment with sulfasalazine was not linked to a decrease in the IgA secretion by PBL. This does not favour a direct effect of sulfasalazine on the mucous-associated lymphoid tissue.

Six cases of follicular lymphoma contained an abundant plasma cell component. With immunoperoxidase techniques, this was found to demonstrate monotypic cytoplasmic marking for either K or L Ig light chain in five cases, and for IgA heavy chain only in one case. A histogenetic relationship between follicular center cells and plasma cells was suggested by cell forms morphologically intermediate between these two types and by monotypic plasma cells in the neoplastic follicles. The progressive differentiation of follicular center cells into Ig-secreting cells in these cases is likely to be the result of an alteration of the immunoregulatory mechanisms that usually block the differentiation of follicular lymphomas.

Abstract: A facility for polarized epithermal neutrons of high intensity is set up at the Los Alamos National Laboratory for parityviolation and time reversal experiments at neutron resonances over a wide range of neutron energies. The beam is polarized with the aid of a polarized proton target used as a neutronspin filter. Total cross section measurements as well as capture gamma-ray experiments will be carried out. The main features of this system will be discussed.

Diamond seeds were assessed for their role in the heterogeneous nucleation for diamond films deposited on silicon using chemical vapor deposition. Two diamond seed sizes-4 nm and 20 nm-were studied. The study revealed that the larger seed size, even when with a smaller seed density, produces a larger grain size near the interface region, and led to a higher in-plane thermal conductivity as measured by Raman thermography. By fine control of the seed size and density, thermal conductivity near the nucleation region can therefore be improved. This demonstrates that the seeding condition is critical to diamond film growth for thermal applications in electronic devices.

This paper deals with the simulation of ultrasonic transmission tomography systems in water-immersed to nondestructively inspect highly heterogeneous materials with fractures. The time-domain Elastodynamic Finite Integration Technique (EFIT) was employed for all numerical simulations because is able to reliably simulate this type of ultrasonic problems. The EFIT code was implemented using OpenCL and PyOpenCL. Several ultrasonic tomography inspection setups were numerically simulated under different conditions varying the number of ultrasonic sources and their size and number and different operation schemes. Sinograms of concrete scenarios were computed and compared for each configuration, using homogeneous materials with similar fracture types and experimentally validated.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.