Drilling operations on Carbon Fiber Reinforced Plastics (CFRP) have become crucial for the manufacturing process of multiple components on the aerospace industry. The main objective of this research ...is to develop a comparative analysis between a step geometry drill bit, currently used in the aerospace industry for drilling processes in CFRP with a hole diameter of 9.54 mm, and the double point angle geometry. The tool material is tungsten carbide with a diamond coating. The performance of each cutting geometry is assessed based on the type of tool wear, the evolution of the thrust force and cutting torque and the onset of machining induced damage on the test specimens. Although the main wear mechanism suffered by both tools was very similar, it was observed a remarkable influence of the cutting geometry on the tool wear evolution and the associated thrust force. This different performance also affected the onset of the machining induced damage.
The purpose of this study was to determine the magnitude and distribution of acute gastrointestinal illness (GI) in the Chilean population, describe its burden and presentation, identify risk factors ...associated with GI and assess the differences between a 7-day, 15-day and a 30-day recall period in the population-based burden of illness study design. Face-to-face surveys were conducted on 6047 randomly selected residents in the Metropolitan region, Chile (average response rate 75·8%) in 2008. The age-adjusted monthly prevalence of GI was 9·2%. The 7-day recall period provided annual incidence rate estimates about 2·2 times those of the 30-day recall period. Age, occupation, healthcare system, sewer system, antibiotic use and cat ownership were all found to be significant predictors for being a case. This study expands on the discussion of recall bias in retrospective population studies and reports the first population-based burden and distribution of GI estimates in Chile.
To propose classification criteria for patients entering clinical and basic studies on reactive arthritis (ReA).
From a MEDLINE search of articles published between 1980 and 1996, we identified ...reports on HLA-B27 related ReA and Reiter's syndrome as study groups and analyzed the items that constituted the diagnostic, classification, and inclusion (or entry) criteria of patients. We developed disease categories that constituted our classification proposal.
We reviewed 175 articles containing 110 study groups of patients with ReA and 94 with Reiter's syndrome. Most articles (89.7%) relied on arthritis for diagnosis, but only 48.0% relied on infection. Only 22.5% of articles used published criteria for diagnosis. Articles including a bacterial name to further describe a group of patients with ReA relied on cultures at the site of infection, serum antibodies, or both to confirm the diagnosis. There were inter/intra-group variations and overlapping of diagnostic criteria, at least 32 different terms referring to ReA or Reiter's syndrome, and 6 patterns of disease. According to these data, we propose 3 categories of disease for patients entering clinical and basic studies on ReA: probable ReA (2 subgroups); definite ReA triggered by bacteria (2 subgroups); and bacterial-associated undifferentiated oligoarthritis or spondyloarthropathy.
This proposal provides a rationale for reducing the heterogeneity found in criteria for including patients with ReA in research and to facilitate scientific communication. In contrast to diagnostic criteria, this proposal does not restrict the study population to a minority of patients, but allows the investigator to include several forms of disease and to analyze results according to different categories.
Many investigators have observed mild cognitive deficits in essential tremor (ET), yet the functional significance of these deficits is unclear. Also, there are very few data in which functional ...activity in ET has been divided into cognitively based activities (remembering appointments) versus motor-based activities (writing cheques).
The authors (1) compared functional level in ET cases versus controls, assessing functional activities that are cognitively based and those that are dependent upon both motor and cognitive factors, and (2) determined whether lower mini mental status test scores in ET cases have a functional correlate.
In a population-based study of people > or = 65 years in central Spain (NEDICES), a 37-item version of the Mini-Mental State Examination (37-MMSE) and an 11-item version of the Pfeffer Functional Activities Questionnaire (FAQ) were administered to non-demented ET cases and controls.
The FAQ was 55.5% higher (ie, lower function) in 208 cases than 3616 controls (2.8+/-4.8 vs 1.8+/-4.2, p<0.001). Cases reported more difficulty (ie, higher FAQ scores) with FAQ items that were cognitive measures as well as FAQ items that were cognitive-motor in nature. In cases, a lower 37-MMSE was associated with more difficulty on both cognitively based and cognitive-motor-based FAQ items (p<0.001).
In this large, population-based study, ET cases reported more functional difficulty than controls, and this functional difficulty was present in both cognitive and cognitive-motor domains. Lower cognitive test scores were associated with more reported functional difficulty, indicating that lower cognitive test scores in ET, rather than being inconsequential, have a clear clinical-functional correlate.
Epidemiological data on the incidence of cerebrovascular diseases in our country are scarce. A representative population-based study with a large denominator is required.
To present the design of the ...study on stroke incidence in Spain, entitled Iberictus.
We conducted a prospective, population-based study on the incidence of strokes and transient ischemic attacks, in which it is possible to distinguish: 1) population with a steady risk, which was well defined and had a broad denominator. We included all the cases in which the first episode of acute cerebrovascular disease was diagnosed among those over the age of 17 years (with no upper age limit) with their habitual residence in the areas of study between the 1st January and 31st December 2006: Lugo, Segovia, Talavera de la Reina, Mallorca and Almeria (total denominator, 1,440,997 inhabitants; minimum denominator per area, 100,000 inhabitants); 2) source of multiple and complementary data: hospital records (minimum basic data set, discharge abstracts), emergency and primary care records for the area with diagnostic codes 430-39 and 674.0 (International Classification of Diseases-9), population-based mortality records; 3) standardised definitions: diagnostic categorisation (MONICA-World Health Organisation, 1987), pathological classification (ischaemia, haemorrhagic), topography and aetiology; 4) presentation of data in suitable age groups, by sex and overall; 5) pilot study and analysis of inter-observer agreement among researchers.
With this design, the Iberictus study satisfies the methodological criteria as an 'ideal' study of the incidence of acute cerebrovascular diseases proposed by Malgrem, Sudlow and Warlow, and represents a unique opportunity to further our knowledge of the epidemiology of strokes in our country.
A low-temperature photoluminescence (PL) study of liquid phase epitaxy grown undoped and Te-doped In0.14Ga0.86As0.13Sb0.87 layers lattice matched to n-type GaSb is reported. The quaternary solid ...solutions In x Ga1−x As y Sb12y are promising materials for the fabrication of optoelectronics devices operating in the spectral range of 3−5 μm because these alloys can form type II heterojunctions with both staggered and broken-gap alignments. The PL for the undoped InGaAsSb layer shows three narrow exciton-related peaks with narrow full width at half-maximum (FWHM), which is an evidence of the good crystalline quality of the epilayers. The PL spectrum for a slight Te-doped InGaAsSb layer shows a red shift, which is more remarkable for high excitation powers. When increasing the Te-doping in the quaternary alloys, the PL spectra show that the donor-to-acceptor radiative transition associated with neutral tellurium and a neutral acceptor is dominant, although the band-to-band transition is present too.
The management of the energy produced by photovoltaic panel stations can be converted into a management where the consumer himself can have a tendency in the final price of the price of the energy he ...pays. The system of generation and sale of energy by means of photovoltaic systems can be managed through global BLOCKCHAIN type procedures.
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