Influence of chemical composition, porosity and fractal dimension on the electrical conductivity of carbon blacks.

Carbonaceous materials analyzed in this investigation were six nanometric particle size carbon blacks. Carbons were texturally characterized by gas adsorption (N2, 77 K), helium and mercury density and mercury porosimetry measurements. Electrical conductivity was determinated by impedance spectroscopy, at room temperature. Several works related to the electrical conductivity and to textural parameters of carbon blacks, such as: porosity, specific surface area, etc., have been carried out. However, there are a type of parameters, such as the fractal dimension, the percentage of macropores, the particle size, or the packing density, that are also related to the electrical conductivity, but they have not been previously investigated. In this work, it has been researched how the increase in interparticle/intraparticle porosity decreases the electrical conductivity of the samples studied. Therefore, it is possible to conclude that in this study a complete research work on electrical conductivity has been carried out.

[Sentinel node biopsy in patients with breast cancer and previous breast surgery]. / Biopsia de ganglio centinela en pacientes con cáncer de mama y cirugía mamaria previa.

AIM: The aim of this study was to establish the efficacy and safety of sentinel lymph node biopsy for lymph node staging in patients with breast cancer and prior breast surgery, considering its extension, localization and time since the previous surgical procedure. MATERIAL AND METHODS: A sentinel lymph node biopsy was performed in 38 patients with early breast cancer and previous breast surgery: recent excisional biopsy in 22 patients (Group I), previous lumpectomy or mammoplasty in 16, including one case of cancer treated with breast-conserving surgery (tumor recurrence). Lymphoscintigraphy was performed after periareolar injection, also sometimes adding an injection near to the surgical scar. After removing the sentinel node, axillary lymph node dissection was performed when the lymph node was positive (and not localized). RESULTS: The efficacy of the scintigraphic localization of the sentinel node was 92.1% of the patients, with 15.8% of extra-axillary drainages. Axillary intraoperative detection was 81.6%. The identification rate after recent excisional biopsy or previous surgery was similar (81.8 vs 81.2%). However, extra-axillary sentinel nodes were more frequent in Group II (9.1 vs 25%). Having a localization of previous surgical procedures in upper outer quadrant caused drainages outside of the axilla more frequently (27.2 vs 11.1%). Axillary detection rate was similar to other quadrants (81.8 vs 81.5%). The rate of breast cancer-related events was 5.2% (2/38), without axillary recurrences (mean follow-up: 3 years). CONCLUSION: Sentinel lymph node biopsy in patients with previous but not extensive breast surgery is safe. Extra-axillary drainages are more common when the previous surgical area was wide, especially in the upper-outer quadrant.

Relación entre características del dolor crónico y los niveles de depresión / Relationship between chornic pain carácter and depression levels

Objetivo El objetivo de este trabajo es estudiar variables del dolor crónico, concretamente la intensidad, el tiempo o la etiología, e identificar su relación con el estado de ánimo del paciente, en una muestra de pacientes con dolor crónico heterogéneo y sin antecedentes personales de depresión. Material y método La muestra está compuesta por 106 pacientes con dolor crónico que acuden a la Unidad del Dolor del Servicio de Anestesia del Hospital Clínico Universitario de Salamanca en consulta ambulatoria. Los participantes completaron una batería de cuestionarios donde, en una primera parte, se recogían los datos sociodemográficos, el diagnóstico clínico, el tiempo de padecimiento del dolor y la intensidad del mismo a través del EVA (escala visual analógica), con tres valoraciones por parte del paciente: durante la entrevista y en los momentos de máxima y mínima intensidad. Posteriormente cumplimentaron el Inventario de Depresión de Beck (BDI) para evaluar su estado de ánimo. La muestra se dividió en tres grupos de estudio en función de la etiología: oncológico, neuropático y nociceptivo, y se efectuaron análisis de control de las variables intensidad y tiempo de dolor mediante ANOVAS unifactoriales, comprobándose que los grupos eran homogéneos. Resultados y conclusiones Los resultados indican que la intensidad del dolor y el tiempo que llevan sufriendo el mismo no influyen sobre el estado anímico, y tan sólo el tipo de dolor tiene efecto sobre la depresión, apreciándose que el grupo oncológico es el que ofrece puntuaciones correspondientes a niveles clínicos. Los pacientes con dolor neuropático y nociceptivo conforman dos grupos muy homogéneos en la repercusión afectiva (oscilando entre niveles leves y moderados) derivada del padecimiento álgico. Los resultados refuerzan la teoría de la multiplicidad de variables intervinientes en la percepción dolorosa, alejándonos de la unidireccionalidad del axioma que indica que la reacción psicológica es proporcional a la severidad y al tiempo padecido de dolor

Objective The present study aims to assess chronic pain, an attempt is made to study variables such as intensity, time and origin (nature) of pain and to identify their relationship to the patient’s state of mind. A heterogenous sample of patients suffering from chronic pain is used and results are discussed. Material and method 106 patients with chronic pain participated in the study. Subjects were recruited from the Pain Unit of the Department of Anesthesia of the University Hospital Clinic of Salamanca, Spain. First, participants were asked to fill out a number of questionnaires which included socio- demographic data, clinical diagnosis, duration of suffering across time and pain intensity through VAS (Visual Analogical Scale). Second, they were asked to rate a series of statements a) during the interview and b) during moments of high and low intensity. Finally, the Beck Depression Inventory (BDI) was used to assess their state of mind. Participants were divided in three groups, according to the nature of their pain: oncological, neuropathic and nociceptive. Control analyses of pain intensity and time of suffering were conducted (using uni-factorial analyses: ANOVAS) to assure homogeneity among the participants. Results and conclusions Results show that neither pain intensity nor duration of suffering across time affect one’s state of mind. The nature of the pain seems to have an impact on depression, therefore the oncology group gave higher ratings on the clinical scale. Ratings of patients with neuropathic o nociceptive pain fluctuated between low and moderate levels of emotional impact. In the present study, the uni-directional axiom which implies that psychological reactions are closely related to the severity and the duration of pain is seriously questioned. The results seem to reinforce the theory of the existence of a wide range of variables that affect the perception of pain

¿Los niños amamantados de forma exclusiva durante 6 meses pesan menos que los de la población de referencia aragonesa? Estudio de antropometría comparada a los 6 meses de vida / Do 6 months breastfed infants weight less than infants of Aragon reference population? Study of compared anthropometrics at 6 months of life

El objetivo principal de este estudio es comparar el desarrollo pondero-estatural de niños amamantados de forma exclusiva durante seis meses de una cohorte de niños que son atendidos en un Centro de Salud con los de la población aragonesa de referencia cuyos datos se obtuvieron del estudio longitudinal del crecimiento de la Fundación Andreas Prader. Se estima que la tasa de lactancia materna de esta población de referencia a partir de los 3meses de vida es menor de un 30%. Se pretende con esta comparación saber si el desarrollo delos niños amamantados es peor y si por lo tanto existe fundamento para introducir la alimentación no materna entre los 4 y los 6 meses, o si por el contrario es correcto recomendar lactancia materna exclusiva hasta los 6 meses de vida

The main goal of this study is to compare the growth and physical development of exclusive breastfed infants during 6 months of a cohort of infants of a health centre with the reference population of Aragon obtained of Longitudinal Study of Growth and development of Andreas Prader Foundation.The prevalence of breast feeding in this population is less than 30%. The authors want to know if the growth and development of exclusive breastfeeding during 6 months is worse than the reference population. So that it may be necessary to introduce non maternal food before 6months

Recycling of hazardous waste materials in the coking process.

Every year the coking industry produces a significant amount of tarry and other wastes in byproducts plants. For the most part these wastes have not been put to any practical use. In addition, an integrated factory produces several waste oils which differ in composition and quantity, e.g., wastes from the steel rolling-mill process. In this work, the possibility of using such waste materials as binders in a partial briquetting process for metallurgical coke production is explored. By means of this coking procedure, a strong metallurgical coke not inferior in quality to coke from conventional coal blends is produced at pilot and semi-industrial scales. The use of such wastes, some of which are classified as hazardous materials, will avoid the need for dumping, thereby contributing to the protection of the environment as well as reducing the costs related to waste disposal.

Study of the composition of tars produced from blends of coal and polyethylene wastes using high-performance liquid chromatography.

Tars produced at semi-industrial scale in a coke oven of 6 x 10(3) kg capacity were used to investigate the effect of using polyethylene waste as an additive in the carbonization process with coal. The polyethylene wastes used were low-density polyethylene from the agriculture greenhouses and high-density polyethylene from domestic sources. The high-performance liquid chromatography analysis of the soluble fractions in toluene and carbon disulfide, using two polystyrene-divinylbenzene columns and a mixture of dichloromethane-methanol as a mobile phase, provides useful information on the composition of tars and their derived pitches in terms of the substitution and molecular topology of polynuclear aromatic compounds (PACs). Differences in composition of tars produced with polyethylene waste at 1% (w/w) have been found to be negligible, while a higher amount of the waste (3%, w/w) promoted the formation of peri-condensed PACs at the expense of the substituted cata-condensed PACs. This behaviour is due to more extensive secondary reactions of tar precursors via dealkylation and aromatic condensation taking place during the carbonization process as a consequence of a more viscous co-carbonizing system. Changes in tar composition caused by this amount of polyethylene waste addition were comparable to those promoted by an increase in the carbonization temperature at semi-industrial and industrial ovens and by the coal preheating before the carbonization process. The characteristic features in tar composition were also found for the derived pitches from tars obtained with the polyethylene waste addition.

Gas chromatographic study of the volatile products from co-pyrolysis of coal and polyethylene wastes.

The aim of this study was to determine the volatile products distribution of co-processing of coal with two plastic wastes, low-density polyethylene from agriculture greenhouses and high-density polyethylene from domestic uses, in order to explain the observed decrease in coal fluidity caused by polyethylene waste addition. Polymeric materials, although they are not volatile themselves, may be analysed by gas chromatography through the use of pyrolysis experiments. In this way, a series of pyrolysis tests were performed at 400 and 500 degrees C in a Gray-King oven with each of the two plastic wastes, one high-volatile bituminous coal and blends made up of coal and plastic waste (9:1, w/w, ratio). The pyrolysis temperatures, 400 and 500 degrees C, were selected on the basis of the beginning and the end of the coal plastic stage. The organic products evolved from the oven were collected, dissolved in pyridine and analysed by capillary gas chromatography using a flame ionization detector. The analysis of the primary tars indicated that the amount of n-alkanes is always higher than that of n-alkenes and the formation of the alkenes is favoured by increasing the pyrolysis temperature. However, this effect may be influenced by the size of the hydrocarbon. Thus, the fraction C17-C31 showed a higher increase of n-alkenes/n-alkanes ratio than other fractions. On the other hand, the difference between the experimental and estimated values from tars produced from single components was positive for n-alkanes and n-alkenes, indicating that co-pyrolysis of the two materials enhanced the chemical reactivity during pyrolysis and produced a higher conversion than that from individual components.

[Reliability and validity of the Legeron Riviere and Marboutin Questionnaire of Anticipatory Cognition (QAC)(1991): a study of a sample of Spanish women]. / Fiabilidad y validez del cuestionario de cogniciones anticipatorias (QCA) de Légeron Rivière y Marboutin (1991): estudio en una muestra de mujeres españolas.

The reliability and validity of Legeron Riviere and Marboutin's Anticipatory Cognition Questionnaire were studied in a sample of Spanish women (age range 19-60 years). Internal consistency was high and the predictive validity was good.

[Incidence and multivariable genesis of postmenopausal depression]. / Incidencia y génesis multivariable de la depresión en la postmenopausia.

The present work tried to find out the postmenopausal depression rates and whether depressive symptoms are due to hormonal disturbances or to multiple variables, not only biological, but also psychological and social. The sample included 128 women with no psychiatric history, pharmacological therapy or recent, important events. Results show a high rate of depression related to different variables, but especially over that of the negative anticipated thinking.

[Psycho-oncology: influence of external perception on the personality characteristics in women with cancer]. / Psicooncología: influencia de la percepción externa sobre los rasgos de personalidad en mujeres con cáncer.

Personality traits between two female groups suffering cancer with different symptomatology and treatment are compared. The authors study 59 female patients: 35 with breast cancer and 24 with hematologic neoplasia. The MMPI Inventory and the Scale to Measure of Aggression by Ledesma et al were studied. It has been found that there are similar personality traits in both groups although there are some significant differences. The group with breast cancer showed an increase both in the MMPI Si scale (Social introversion) and in self aggression with respect to the hematologic neoplasia group. On the other hand, the patients with hematologic cancer showed an increase of the hypochondria, depression and paranoia as well as hetero aggression.

Concentrations of 2,3-diphosphoglycerate (2,3-DPG) in canine blood (healthy dogs, dogs with cardiopulmonary insufficiency and dogs with renal insufficiency).

This study deals with the determination of 2,3-DPG concentrations in canine blood. The results obtained demonstrate the intraerythrocytic location of this organic phosphate as well as its equimolar relationship with the haemoglobin tetramers in blood obtained from clinically healthy dogs. The average value obtained for this group of healthy dogs (n = 93) was 5.81 +/- 0.07 mmol of 2,3-DPG/L of erythrocytes. In dogs with cardio-pulmonary insufficiency (n = 12) and uraemic syndrome (n = 10), a greater concentration of 2,3-DPG was observed, together with a loss of the equimolar relationship between this phosphate and the Hb tetramers. Furthermore, in the group of dogs with uraemic syndrome we observed a highly significant correlation between the blood values of urea and the concentration of 2,3-DPG expressed in relation to the haemoglobin tetramers.

[Experience in the use of central venous catheterization via subclavian puncture in a pediatric hospital]. / Experiencia en el uso de la cateterización venosa central por punción subclavia en un hospital pediátrico.

OBJECTIVE: To assess the frequency and type of complications during central venous catheter installation by subclavian puncture, and during its use in children admitted to an ICU. PATIENTS AND METHODS: Patients from one month to 15 years of age, admitted to the Intensive Care Unit of the Hospital de Pediatría Centro Médico Nacional, Siglo XXI, who underwent a percutaneous infraclavicular subclavian puncture for central venous catheter complications were included. Clinical features, diagnosis, complications and indications for the procedure were registered. RESULTS: 92 patients and 102 subclavian punctures were included for analysis. Effectively index was 88.3%. Main diagnosis was infectious diseases in 29.4% and neoplasia in 22.5%. Hemodynamic monitoring was the more frequent indication for the procedure (44%). Of the catheter 45% were successfully installed at first intent. The complication in the installation appear in 11.7%. Was arterial subclavian puncture (6.8%), hematoma (2.9%), without hemodynamic deterioration no any case. The mean time of permanence was 8.8 days. The late complications was present in average 7.3 days, in 18.6% of the cases. Predominance infection in entrance place of catheter. CONCLUSIONS: Installation of venous central catheter by subclavian puncture prove a great utility in our patients, with a few complications and a high effectively. For experimental personal the central venous catheterization by subclavian puncture in pediatric patients to be importance in the first place in critical ill children.

[Amenorrhea following the administration of oral contraceptives]. / Amenorrea despues de la administracion de contraceptivos orales.

PIP: It is estimated that about 2.2% of women experience amenorrhea and anovulatory cycles after discontinuing use of oral contraceptives (OCs), although exact figures are lacking due to differences of definition and problems of diagnosis. Several possible mechanisms to explain the occurrence of postpill amenorrhea have been suggested, including endometrial atrophy and fibrosis, changes in the ovaries similar to those found in Stein-Levanthal syndrome, hypothalamic disorder, late menarche, irregular cycles, and periods of amenorrhea before or during OC use. Previous pregnancies, duration of pill use, and formulation utilized are apparently not related to occurrence of post-pill amenorrhea. Clinical diagnosis requires detection of ovulation by means of basal body temperature, cervical mucus changes, and vaginal smears. If amenorrhea persists after administration of a progestagen to induce bleeding, more complete examinations must be done to exclude pituitary tumor, Cushing's syndrome, thyroid problems, and possible precocious menopause or anorexia nervosa. X-rays, administration of thyroid or suprarenal hormones, gonadotropins, or estrogens, an endometrial biopsy, or laparoscopy may be necessary. Generally all test values are normal except that levels of estrogens, follicle stimulating hormone, and luteinizing hormone are usually reduced. Treatment of post-pill amenorrhea can take various forms. About 5% of cases appear to resolve spontaneouusly; efforts should therefore be made to detect ovulation through basal body temperature, cervical mucus and vaginal smears. Corticosteroids including prednisone and dexametasone may administrered, or if estrogen levels are low and the patient fails to respond to progestagens with withdrawal bleeding, clomiphene may be used. Human menopausal gonadotropin or human chorionic gonadotropin can be in patients with low estrogen levels who do not respond to clomiphene. Ergocriptine derivatives may be used in cases with associated galactorrhea due to basal hyperprolactinemia. Palliative treatment with OCs may be used in patients who wish to avoid pregnancy. The prognosis is always poor in the presence of galactorrhea or if progestagen administration is not followed by withdrawal bleeding or estrogen levels are low. Treatment is usually futile in cases of polycystic ovaries that have sclerosed. The most significant feature of such amenorrhea is its role in infertility. If the patient wishes to become pregnant after some period of OC use, it is advisable to interrupt treatment periodically until 1-2 normal menstrual cycles have reappeared, especially in young patients who had irregular cycles before initiating hormonal contraception.^ieng