ABSTRACT
The complex tribochemical nature of lubricated tribological contacts is inaccessible in real time without altering their initial state. To overcome this issue, a new design of a pin-on-disc tribological apparatus was developed and combined with synchrotron X-ray absorption spectroscopy (XAS). Using the designed apparatus, it is possible to study in situ the transient decomposition reactions of various oil additives on different surfaces under a wide range of realistic operating conditions of contact pressure (1.0-3.0 GPa), temperature (25-120 °C), and sliding speed (30-3000 rpm or 0.15-15 m/s). To test the apparatus, several tribological tests were performed at different shearing times ranging from 2.5 to 60 min. These tests were carried out under helium atmosphere at a temperature of 80 °C, contact pressure of 2.2 GPa, and sliding speed of 50 rpm. The XAS experiments indicate that the zinc dialkyldithiophosphate antiwear additive decomposes in the oil to form a tribofilm on the iron surface at different reaction kinetics from the ones of the thermal film. The tribofilm composition evolves much faster than the one of the thermal film, which confirms that the formation of the tribofilm is a thermally activated process similar to the one of the thermal film but accelerated by shear. Furthermore, the results indicate that the sulfur of the formed film, whether a tribofilm or a thermal film, appears initially in the form of sulfate, with some sulfide, which under heat or shear is reduced into mainly sulfide.
ABSTRACT
The aim of this study was to describe spirometric reference equations for healthy never-smoking European adults aged 65-85 yrs and to compare the predicted values of this sample with those from other studies including middle-aged and/or older adults. Reference equations and normal ranges for forced expiratory volume in one second (FEV1), forced vital capacity (FVC), forced expiratory volume in six seconds (FEV6), FEV1/FVC ratio and FEV1/FEV6 ratio were derived from a healthy subgroup of 458 subjects aged 65-85 yrs. Spirometry examinations followed the 1994 American Thoracic Society recommendations and the quality of the data was continuously monitored and maintained. Reference values and lower limits of normal were derived using a piecewise polynomial model with age and height as predictors. The reference values of FEV1 and FVC from the present study were higher than those given by prediction equations from the European Community for Coal and Steel. By contrast, use of prediction equations from Caucasian-American elderly subjects (Cardiovascular Health Study) consistently overpredicted FVC and FEV1 in females by 8.5 and 2.1%, respectively. In males, equations from the Cardiovascular Health Study overpredicted FVC by 2.8%, whilst underpredicting FEV1 by 2.5%. In conclusion, these results underscore the importance of using prediction equations appropriate to the origin, age and height characteristics of the subjects being studied.
Subject(s)
Aging/physiology , Spirometry , Aged , Aged, 80 and over , Body Height , Body Weight , Cohort Studies , Female , Humans , Male , Predictive Value of Tests , Reference Values , Respiratory Function Tests , Sex FactorsABSTRACT
OBJECTIVE: To describe the impact factor of Archivos de Bronconeumología from 1997 until 2000 and to identify the patterns of citation of the journal and topics having the greatest impact. METHOD: SCISEARCH was used to locate citations of articles published by Archivos de Bronconeumología between 1995 and 1999. The following data were collected for each article: year of publication, authors, journal, country of publication, language, specialty or specialties, institution(s), residence of the first author and topic. The impact factor was calculated as the ratio of citations received in one year by articles published in Archivos de Bronconeumología during the two previous years and the total number of articles published by Archivos de Bronconeumología over the two years under study. RESULTS: The impact factor of Archivos de Bronconeumología was 0.107 in 1997, 0.089 in 1998, 0.105 in 1999 and 0.119 in 2000. Citations were found in a wide range of source journals, with respiratory system publications having little weight. Citations were made mainly by Spanish authors (75%) and self-citation was restrained (21.1%). Topics related to tuberculosis and respiratory infections (23.6% of the citations received) and chronic obstructive pulmonary disease (12.5%) made the greatest impact. CONCLUSION: The impact factor of Archivos de Bronconeumología is modest, although higher than those of some other publications included in Journal Citation Reports.
Subject(s)
Databases, Bibliographic , Periodicals as Topic/statistics & numerical data , Publishing/statistics & numerical data , Pulmonary Medicine , SpainABSTRACT
OBJETIVO: Describir el factor de impacto de ARCHIVOS DE BRONCONEUMOLOGÍA desde 1997 hasta 2000 e identificar los patrones de citación de la revista y las áreas temáticas con mayor repercusión. METODOLOGÍA: Se recopilaron las citas recibidas por los artículos publicados por ARCHIVOS DE BRONCONEUMOLOGÍA entre 1995 y 1999 mediante una búsqueda en SCISEARCH. De cada artículo fuente se recogieron las siguientes variables: año de publicación, autores, revista, país de publicación, idioma, especialidad/es, institución/es, residencia del primer firmante y área temática. El factor de impacto se calculó como el cociente entre las citas recibidas en un año por los artículos publicados en ARCHIVOS DE BRONCONEUMOLOGÍA los 2 años anteriores entre el total de artículos publicados por la revista en esos 2 años. RESULTADOS: El factor de impacto de ARCHIVOS DE BRONCONEUMOLOGÍA fue de 0,107 en 1997, 0,089 en 1998, 0,105 en 1999 y 0,119 en 2000. Se aprecia un patrón de citaciones caracterizado por la dispersión de las revistas fuente, con escaso peso de las publicaciones del área de sistema respiratorio, un predominio de las citas emitidas por autores españoles (75 por ciento), con una autocitación contenida (21,1 por ciento) y una mayor repercusión de las áreas temáticas relativas a tuberculosis e infecciones respiratorias (23,6 por ciento de las citas recibidas) y a la enfermedad pulmonar obstructiva crónica (12,5 por ciento). CONCLUSIÓN: ARCHIVOS DE BRONCONEUMOLOGÍA posee un factor de impacto discreto, aunque superior al de otras publicaciones biomédicas incluidas en el Journal Citation Reports (AU)
Subject(s)
Databases, Bibliographic , Pulmonary Medicine , Spain , Periodicals as Topic , PublishingABSTRACT
This study analyses the evolution of the bibliometric indicators of productivity and repercussion of European Union (EU) research into the respiratory system during the period from 1987-1998, describing the geographical distribution. Using MedLine, a selection was made of those articles by EU authors published between 1987-1998 in 38 respiratory system journals (classification from the Institute for Scientific Information). The journals, country of origin, number of articles and the relation to socioeconomic data, productivity index, visibility index, expected impact factor (EIF) and relative impact factor (RIF) were all analysed. The number of EU publications in respiratory system journals experienced an exponential increase, going from 606 articles (14.3% of world production) in 1987, to 2,325 (33.2%) in 1998. During this same period, the EIF increased from 1,258 to 2,111. The greatest gross productivities were those of the UK, France, Italy and Germany, although when corrected for number of inhabitants, Sweden, the Netherlands, Belgium and Denmark headed the list. The countries with the greatest mean EIF were the Netherlands, the UK, Spain and Belgium. In conclusion, productivity and repercussions of European Union research of the respiratory system experienced an important increase during this period.
Subject(s)
Authorship , Bibliometrics , Periodicals as Topic/statistics & numerical data , Publishing/statistics & numerical data , Respiratory System , Europe , Humans , Research/statistics & numerical dataABSTRACT
Recurrent epiphora after external dacryocystorhinostomy (DCR) can be a frustrating experience for both the patient and the physician. We present the results of a retrospective study of 18 patients with epiphora recurring after external DCR who were operated upon to recreate lacrimal drainage through an endoscopic endonasal approach. The procedure was successful in 83.3% of cases, with no major complications. The results are comparable to those of an external approach, but the cosmetic advantages are clear. It is a 1-stage procedure that permits correction of associated intranasal disease that may be a causative factor in the recurrence of lacrimal obstruction. The endoscopic endonasal approach is a relatively safe and reliable option in the management of recurrent epiphora.
Subject(s)
Dacryocystorhinostomy/adverse effects , Endoscopy , Lacrimal Apparatus Diseases/surgery , Adult , Female , Humans , Lacrimal Apparatus Diseases/etiology , Male , Middle Aged , Recurrence , Reoperation , Retrospective StudiesABSTRACT
The main bibliographic impact factors of ARCHIVOS DE BRONCONEUMOLOGIA for the past two years are estimated. Citations of ARCHIVOS DE BRONCONEUMOLOGIA in 1996 and 1997 by Medicina Clínica and all citing journals grouped under the heading "Respiratory System" in the Science Citation Index were counted. The year the citation appeared and the year of publication of the article in ARCHIVOS DE BRONCONEUMOLOGIA were recorded. The total number of articles published by ARCHIVOS DE BRONCONEUMOLOGIA between 1994 and 1996 were also counted. Based on these data we calculated our journal's impact factor for each year studied. Relative impact factor was also figured. In 1996 the exposure factor achieved was 1.602, the half-life of articles was 2.00 years, the impact factor was 0.069 and the relative impact factor was 1.371. In 1997 the exposure index was 1.477, the citation half-life was 3.00 years and the impact factor was 0.030. In conclusion, the international impact of ARCHIVOS DE BRONCONEUMOLOGIA is modest, although our relative impact factor is greater than that of some other internal medicine publications or specialized journals listed in Journal Citation Reports.
Subject(s)
Bibliometrics , Periodicals as Topic/statistics & numerical data , Publishing/statistics & numerical data , SpainABSTRACT
The aim of this study was to evaluate the evolution of bibliometric indicators for authorship and citation of ARCHIVOS DE BRONCONEUMOLOGIA over the past 20 years. At least 16 articles reporting new research or case reports were analyzed for every other year from 1976 to 1996. The following data were collected for each article: type of document, number of authors and their place of work and specialty, time interval between acceptance and publication, and references (including number, types, language, journal name and year of publication). The number of authors per article (collaboration index) averaged around five and has not varied significantly over the 20 years studied. Pulmonologists predominated among the authors, accounting for about 60% of the total, and most contributions came from a few provinces, mainly Barcelona and Madrid. The interval between reception and publication has gradually increased over the 20 years under review, coming to stand around 9.9 +/- 1.6 months in 1996. Most references (over 80%) cite journals and the proportion of references to books has decreased in recent years (from 12.3% in 1976 to 3.5% in 1996). The journal's index of isolation has increased (from 6.2 to 12.1%), as has the index of self-citation (from 0.4 to 6.2%). Although most cited works are in English (over 80%), the proportion of Spanish-language references increased (from 6.2 to 12.1%). In conclusion, maintenance of the number of collaborating authors, the predominance of journals and English-language sources among references are the main traits that characterize the bibliometric indicators for authorship and citation in ARCHIVOS DE BRONCONEUMOLOGIA.
Subject(s)
Bibliometrics , Periodicals as Topic/statistics & numerical data , Pulmonary Medicine/statistics & numerical data , Authorship , SpainABSTRACT
The clinical course of Duchenne's dystrophy is characterized by respiratory insufficiency secondary to failure of the breathing pump. Up to ten years ago, this respiratory insufficiency was corrected by mechanical ventilation via a tracheostomy. In recent years, nasal mechanical ventilation has been a considerable advance in the treatment of these patients' respiratory problems. We describe a patient with Duchenne's dystrophy who was satisfactorily treated by non-invasive mechanical ventilation.
Subject(s)
Muscular Dystrophies/complications , Respiration, Artificial/methods , Respiratory Insufficiency/etiology , Respiratory Insufficiency/therapy , Adolescent , Humans , Male , Respiratory Insufficiency/diagnosis , SpirometrySubject(s)
Home Care Services , Neoplasms/therapy , Oxygen Inhalation Therapy , Humans , Middle Aged , Palliative Care , Retrospective Studies , Terminal CareABSTRACT
Oral administration of carnitine in normal and diabetic subjects showed a marked decrease in the level of blood glucose during the oral glucose tolerance test (OGTT) except for the three hour samples in diabetic subjects, while a decrease in the level of subsequent blood pyruvate samples was observed during the OGTT in normal and diabetic subjects after the administration of carnitine. During the OGTT, the peak of blood glucose and blood pyruvate level was generally delayed in the diabetic subjects. Furthermore, the mean blood pyruvate levels were elevated above those of normal subjects during the late stages of the test. The mean levels of blood glucose and blood pyruvate of all samples after the administration of carnitine were significantly higher in diabetics than the corresponding values in noramls. Carnitine administration decreased the total blood amino acid nitrogen level only in diabetic subjects. Carnitine caused a highly significant increase in the activity of serum alanine aminotransferase in normal and diabetic subjects, while it had no effect on the activity of serum aspartate aminotransferase. In goats, the level of blood glucose during the intravenous glucose tolerance test (IVGTT) was not affected by carnitine (1,3 or 6 mg/kg body weight). Carnitine in all doses used had no effect on the total blood amino acid nitrogen during the IVGTT, or on the activity of serum alanine aminotransferase and serum aspartate aminotransferase in the fasting samples. Acetyl-D,L-beta-methylcholine had no effect on the level of blood glucose, total blood amino acid nitrogen, the activity of serum alanine aminotransferase or serum aspartate aminotransferase in normal and diabetic subjects. The level of blood pyruvate decreased both in normal and diabetic subjects, in the samples that represented the peak of the curve. Glycine betaine had no effect on blood glucose, pyruvate, total blood amino acid nitrogen and the activity of serum alanine aminotransferase or serum aspartate amino transferase in normal and diabetic subjects or in goats.
