bluuebunny/crossref_metadata_2025 huggingface dataset:
Hemangiopericytoma: long-term outcome revisited
Authors: Schiariti Marco , Goetz Pablo , El-Maghraby Hussien , Tailor Jignesh , Kitchen Neil
Published: July 2010

Object

Hemangiopericytomas are rare tumors that behave aggressively with a high rate of local recurrence and distant metastases. With the aim of determining the outcome and response to various treatment modalities, a series of 39 patients who underwent microsurgical resection for primary meningeal hemangiopericytoma over a 24-year period is presented.

Methods

Patients with hemangiopericytoma were identified from histopathology records and their medical records were analyzed retrospectively by 2 independent reviewers to collect data on surgical treatment, adjuvant therapy, postoperative course, local or distant recurrence, and follow-up.

Results

Of the 39 patients, 19 were male and 20 were female. Mean patient age was 44.1 years. Thirty-four tumors were intracranial and 5 were spinal. The mean follow-up period was 123 months. Twenty-eight patients developed local recurrence. The recurrence rate at 1, 5, and 15 years was 3.5%, 46%, and 92%, respectively. Extraneural metastasis occurred in 8 patients (26%) at an average of 123 months after initial surgery. Recurrences and metastases were treated by surgical excision, external beam radiation therapy (EBRT), chemotherapy, and/or stereotactic radiosurgery. Adjuvant EBRT following initial surgery was found to extend the disease-free interval from 154 months to 254 months, although it did not prevent the development of metastasis. In those patients with EBRT and complete resection, the mean recurrence-free interval was found to be 126.3 months longer (p = 0.04) and overall survival 126 months longer than without EBRT. Furthermore, adjusting for resection, patients undergoing EBRT had 0.33 times increased risk of recurrence compared with those who did not (p = 0.03). A majority of patients remained able to live independently despite revision surgery for recurrence.

Conclusions

The mean follow-up of this patient series represents the longest follow-up duration published to date and demonstrates extended survival in a significant number of patients with hemangiopericytoma. Gross-total resection followed by adjuvant EBRT provides patients with the highest probability of an increased recurrence-free interval and overall survival. Prolonged survival justifies long-term follow-up and aggressive treatment of initial, recurrent, and metastatic disease.
Papillary Carcinoma of the Third Part of the Duodenum: A Case Report and Review of the Literature
Authors: Sayeed Abu , Siraji Dilruba , Begum Mamtaz , Ali SM Ashraf
Published: July 2010

Keywords: distal duodenal tumour; intractable vomiting; resectionDOI: 10.3329/jcmcta.v20i2.5630Journal of Chittagong Medical College Teachers' Association 2009: 20(2):56-59
Residential field site training project abstracts - 47th Batch Session: 2004-2005, 4th year MBBS students, CMC
Authors: Editor The
Published: July 2010

DOI: 10.3329/jcmcta.v20i2.5631Journal of Chittagong Medical College Teachers' Association 2009: 20(2):60-63
Univariate Cubic L1 Interpolating Splines: Analytical Results for Linearity, Convexity and Oscillation on 5-PointWindows
Authors: Jin Qingwei , Lavery John E. , Fang Shu-Cherng
Published: July 2010

We analytically investigate univariate C1 continuous cubic L1 interpolating splines calculated by minimizing an L1 spline functional based on the second derivative on 5-point windows. Specifically, we link geometric properties of the data points in the windows with linearity, convexity and oscillation properties of the resulting L1 spline. These analytical results provide the basis for a computationally efficient algorithm for calculation of L1 splines on 5-point windows.
Micro Data Analysis of Medical and Long-Term Care Utilization Among the Elderly in Japan
Authors: Hashimoto Hideki , Horiguchi Hiromasa , Matsuda Shinya
Published: July 2010

Japan is currently experiencing the most rapid population aging among all OECD countries. Increasing expenditures on medical care in Japan have been attributed to the aging of the population. Authors in the recent debate on end-of-life care and long-term care (LTC) cost in the United States and Europe have attributed time to death and non-medical care cost for the aged as a source of rising expenditures. In this study, we analyzed a large sample of local public insurance claim data to investigate medical and LTC expenditures in Japan. We examined the impact of aging, time to death, survivorship, and use of LTC on medical care expenditure for people aged 65 and above. On the basis of these findings, we conclude that age is a contributing factor to the rising expenditures on LTC, and that the contribution of aging to rising medical care expenditures should be distinguished according to survivorship.
Can Intensive Use of Alcohol-Based Hand Rubs Lead to Passive Alcoholization?
Authors: Bessonneau Vincent , Clément Michel , Thomas Olivier
Published: July 2010

Hand disinfection with alcohols-based hand rubs (ABHRs) are known to be the most effective measure to prevent nosocomial infections in healthcare. ABHRs contain on average 70% by weight of one or more alcohols. During the hand rubbing procedure, users are exposed to these alcohols not only through dermal contact, but also via inhalation, due to the physical and chemical properties of alcohols volatilizing from alcoholic solutions or gels into the air. Ethanol ingestion is well known to increase risks of several diseases (affecting the pancreas, liver, cardiovascular system…), but there is a lack of knowledge about the effects of exposure to other alcohols (including n- or isopropanol) via inhalation and dermal contact, despite the worldwide use of ABHRs. This work aims at discussing possible health effects related to unintentional alcoholization (via inhalation and dermal contact) from professional ABHR usage to suggest the need for more research in this area (but not to question the value of ABHRs). Based upon an average of 30 hand rubbings per healthcare professional per day, it can be assumed that a healthcare worker may be exposed to a maximum 5,500 mg/m3 per work shift, five times above the recommended occupational time weighted average limit. Thus, in order to answer the question posed in the title, studies on spatial and temporal variability of alcohol emission from ABHRs in real world situations and studies on certain high risk individuals are needed.
Integral Kinetic Model for Studying Quercetin Degradation and Oxidation as Affected by Cholesterol During Heating
Authors: Chien John-Tung , Hsu Da-Jung , Inbaraj Baskaran Stephen , Chen Bing-Huei
Published: July 2010

The degradation and oxidation of quercetin, as affected by cholesterol during heating at 150 °C, was kinetically studied using non-linear regression models. Both TLC and HPLC were used to monitor the changes of quercetin, cholesterol and cholesterol oxidation products (COPs) during heating. The formation of COPs, including triol, 7-keto, 7a-OH and 7b-OH, was completely inhibited during the initial 30 minute heating period in the presence of 0.02% quercetin, accompanied by reduction in cholesterol peroxidation and degradation. However, the quercetin degradation or oxidation proceeded fast, with the rate constants (h-1) in the presence of nitrogen, oxygen and the combination of oxygen and cholesterol being 0.253, 0.868 and 7.17, respectively. When cholesterol and quercetin were heated together, the rate constants (h-1) of cholesterol peroxidation, epoxidation and degradation were 1.8 ´ 10-4, 0.016 and 0.19, respectively. The correlation coefficients (r2) for all the oxidative and degradation reactions ranged from 0.82-0.99. The kinetic models developed in this study may be used to predict the degradation and oxidation of quercetin as affected by cholesterol during heating.
Chemistry of Nitroquinolones and Synthetic Application to Unnatural 1-Methyl-2-quinolone Derivatives
Authors: Nishiwaki Nagatoshi
Published: July 2010

The 1-methyl-2-quinolone (MeQone) framework is often found in alkaloids and recently attention was drawn to unnatural MeQone derivatives with the aim of finding new biologically active compounds, however, low reactivity of the MeQone framework prevents the syntheses of versatile derivatives. A nitro group is one of the useful activating groups for this framework that enables a concise chemical transformation. Among nitroquinolones, 1-methyl-3,6,8-trinitro-2-quinolone (TNQ) exhibits unusual reactivity favoring region-selective cine-substitutions that afford 4-substituted 1-methyl-6,8-dinitro-2-quinolones upon treatment with nucleophilic reagents. Contrary to this, 1-methyl-3,6-dinitro-2-quinolone (3,6-DNQ) does not undergo any reaction under the same conditions. The unusual reactivity of TNQ is caused by steric repulsion between the methyl group at the 1-position and the nitro group at the 8-position, which distorts the MeQone framework. As a result, the pyridone ring of TNQ loses aromaticity and acts rather as an activated nitroalkene. Indeed, the pyridone moiety of TNQ undergoes cycloaddition with electron-rich alkenes or dienes under mild conditions, whereby a new fused ring is constructed on the [c]-face of the MeQone. Consequently, TNQ can be used as a new scaffold leading to versatile unnatural MeQone derivatives.
Asymmetry, Symmetry and Beauty
Authors: Sabelli Hector , Lawandow Atoor , Kopra Abbe R.
Published: July 2010

Asymmetry and symmetry coexist in natural and human processes. The vital role of symmetry in art has been well demonstrated. This article highlights the complementary role of asymmetry. Further we show that the interaction of asymmetric action (recursion) and symmetric opposition (sinusoidal waves) are instrumental in generating creative features (relatively low entropy, temporal complexity, novelty (less recurrence in the data than in randomized copies and complex frequency composition). These features define Bios, a pattern found in musical compositions and in poetry, except for recurrence instead of novelty. Bios is a common pattern in many natural and human processes (quantum processes, the expansion of the universe, gravitational waves, cosmic microwave background radiation, DNA, physiological processes, animal and human populations, and economic time series). The reduction in entropy is significant, as it reveals creativity and contradicts the standard claim of unavoidable decay towards disorder. Artistic creations capture fundamental features of the world.
Incidence of Taxane-Induced Pain and Distress in Patients Receiving Chemotherapy for Early-Stage Breast Cancer: A Retrospective, Outcomes-Based Survey
Authors: Saibil S. , Fitzgerald B. , Freedman O.C. , Amir E. , Napolskikh J. , Salvo N. , Dranitsaris G. , Clemons M.
Published: July 2010

Introduction: With the widespread use of sequential anthracycline/taxane–based chemotherapy for early-stage breast cancer, clinicians are becoming rapidly aware of toxicities associated with those regimens. Despite the low incidence reported in the literature of significant arthralgia and myalgia with those regimens, it is clinically evident that a substantial proportion of patients develop such toxicities. We performed a pilot study to investigate the extent of this problem. Patients and Methods: Patients who had received prior adjuvant or neoadjuvant chemotherapy [doxorubicin–cyclophosphamide followed by paclitaxel (AC-T), doxorubicin–cyclophosphamide followed by docetaxel (AC-D), or 5-fluourouracil–epirubicin–cyclophosphamide followed by docetaxel (FEC-D)] completed a retrospective outcomes-based survey. The survey utilized the Functional Assessment of Cancer Therapy–Taxane Scale, the Memorial Symptom Assessment Scale, and a modified Brief Pain Inventory. Results: Interviews were conducted with 82 patients. Interviewees had received AC-T (43%), FEC-D (43%), and AC-D (14%). Pain as a side effect of either the anthracycline or the taxane chemotherapy was reported by 87% of patients. Most of the patients (79%) indicated that their worst pain occurred during the taxane component of treatment. Compared with paclitaxel, docetaxel was reported to cause more pain. Narcotics for pain management were required by 35 of 82 patients (43%). Conclusions: A significant number of patients receiving sequential anthracycline/taxane–based chemotherapy for early-stage breast cancer experience pain, particularly during the taxane component. Prospective patient-reported outcome assessments are needed to help individualize treatment interventions and to improve symptom management in this population.
The Impact of Treatment Modality on Infection-Related Hospitalization Rates in Peritoneal Dialysis and Hemodialysis Patients
Authors: Williams Victoria R. , Quinn Robert , Callery Sandra , Kiss Alex , Oliver Matthew J.
Published: July 2010

Background and Objectives

Infection is a major cause of morbidity and mortality in the dialysis population. This study compares the rates of infection-related hospitalization (IRH) in incident chronic dialysis patients initiating outpatient peritoneal dialysis (PD) and hemodialysis (HD).

Methods and Patients

This was a retrospective cohort study at the dialysis program of a tertiary-care center in Toronto, Canada. Incident chronic dialysis patients that were eligible for both PD and HD and started outpatient dialysis between 1 January 2004 and 31 August 2008 were included. Dialysis modality was assigned at the start of outpatient dialysis treatment. All hospital admissions were reviewed and incidence of IRH was compared between PD and HD using Poisson regression.

Results

Of 264 incident chronic dialysis patients, 168 (64%) were eligible for both treatment modalities: 71 (42%) started outpatient PD and 97 (58%) started outpatient HD. The unadjusted and adjusted incidence rate ratios (IRR) of IRH did not differ significantly between PD and HD: 1.23 [95% confidence interval (CI) 0.65 - 2.32, p = 0.37] and 1.14 (95% CI 0.58 - 2.23, p = 0.71) respectively. There was no difference between PD and HD in the risk of access loss (28% vs 35%, p = 0.73), modality change (22% vs 0%, p = 0.10), or death (17% vs 6%, p = 0.60) following hospitalization for infection. Patients starting outpatient treatment on PD versus HD were more likely to be hospitalized for peritonitis (IRR 3.20, 95% CI 1.16 - 9.09; p = 0.029) and there was a trend for fewer hospitalizations for bacteremia (IRR 0.19, 95% CI 0.028 - 1.30; p = 0.091). The risk of IRH did not differ between PD and HD in the subgroup of patients that received adequate predialysis care (IRR 1.16, 95% CI 0.59 - 2.27; p = 0.67) or when patients starting outpatient HD with a central venous catheter were excluded (IRR 1.52, 95% CI 0.53 - 4.37; p = 0.44).

Conclusions

Patients that initiate outpatient peritoneal dialysis do not have a significantly increased risk of infection-related hospitalization compared to those that initiate outpatient hemodialysis.
Showcasing Differences Between Quality Improvement, Evidence-Based Practice, and Research
Authors: Shirey Maria R. , Hauck Sheila L. , Embree Jennifer L. , Kinner Tracy J. , Schaar Gina L. , Phillips Lori A. , Ashby Shelley R. , Swenty Constance F. , McCool Isabella A.
Published: July 2010

The literature confirms that much confusion exists regarding the terms quality improvement (QI), evidence-based practice (EBP), and research. A multifaceted approach was used to provide clarity regarding these three equally important concepts. First, the authors present a synthesis of the literature that discusses differences between QI, EBP, and research. Second, the authors introduce a newly created comparative table that synthesizes current literature and showcases differences between QI, EBP, and research. Finally, the authors highlight uses of the comparative table within multiple settings.
Building an Organizational Culture of Caring: Caring Perceptions Enhanced with Education
Authors: Glembocki Margaret M. , Dunn Karen S.
Published: July 2010

Background:

This pilot study was undertaken to determine whether an educational intervention called Reigniting the Spirit of Caring (RSC) from Creative Healthcare Management would enhance perceptions of caring behaviors among nurses. A pretest/posttest within-subjects research design was used to evaluate the educational intervention.

Methods:

Investigators used the licensed RSC program as the educational intervention. This study included 36 registered nurses employed in one Midwestern hospital.

Results:

Statistical differences were found in the pretest and posttest measurement of nurses’ perceptions of caring behaviors.

Conclusion:

The RSC program can be used as an effective educational intervention to increase nurses’ perceptions of caring, and the Caring Assessment for the Caregiver tool can be used as an effective tool to measure nurses’ perceptions of caring behaviors.
A Systematic Review of the Effectiveness of Remediation Interventions to Improve NCLEX-RN Pass Rates
Authors: Pennington Tracy D. , Spurlock Darrell
Published: July 2010

First-time NCLEX-RN pass rates are important measures of educational quality in prelicensure nursing education programs. Licensure pass rate problems has been the subject of countless nursing education articles and studies over the past several decades. To improve NCLEX-RN pass rates, remediation is often prescribed for students who have academic performance deficits. This article presents a systematic review of studies on remediation interventions and their effects on NCLEX-RN pass rates. Most studies of remediation and its effects on licensure pass rates are descriptive program evaluation reports. The overall quality of studies included in this review is uneven but generally low. Nursing education researchers should focus on conducting higher quality intervention studies in which the fidelity of remediation interventions can be examined. Viewing licensure pass rates from a process improvement perspective and accounting for pass rate variations could also change the nature of scholarship on this topic.
Quality and Safety Education for Nurses Clinical Evaluation Tool
Authors: Walsh Teresa , Jairath Nalini , Paterson Mary A. , Grandjean Cindy
Published: July 2010

An efficient evaluation tool is essential when measuring the clinical performance of undergraduate nursing students. It is also important that this evaluation tool accurately assess the critical competencies that students must demonstrate in the clinical setting. The tool should be unambiguous, succinct, and adaptable to a wide variety of clinical experiences and faculty. As part of a curriculum improvement initiative for their baccalaureate nursing program, the nursing faculty teaching in a 4-year undergraduate program identified the need for the development of a new clinical performance evaluation tool for the evaluation of undergraduate nursing students in each clinical placement. The resultant tool more accurately appraised clinical capabilities by focusing on quality and safety in health care, and it permitted the evaluation of critical thinking skills and team communication.
Development of Simulation Scenarios for an Adolescent Patient with Diabetic Ketoacidosis
Authors: Schneider Sarver Patricia A. , Senczakowicz Elizabeth A. , Slovensky Bernadette Murphy
Published: July 2010

Changes in health care delivery have shifted the care of pediatric patients primarily to the outpatient setting, with the exception of children and adolescents requiring complex, highly acute care. Thus, nurse educators are challenged to provide nursing students with pediatric learning experiences and are further confounded by the relative paucity of available clinical placements. Nurse educators are exploring the use of simulation to provide realistic alternatives to pediatric clinical experiences. The development of simulation scenarios focused on the care of an adolescent patient presenting with diabetic ketoacidosis is discussed. A review of the current literature addressing the use of simulation in nursing education and the advantages and challenges of designing, implementing, and evaluating simulation scenarios are also discussed.
A Bold Adventure in Innovation: An International Off-Campus Master’s Degree Program
Authors: Jones Patricia S. , Van Cleve Lois , King Helen E. , Bossert Elizabeth , Herrmann Marilyn M.
Published: July 2010

In response to the global shortage of nursing faculty, Loma Linda University School of Nursing offered an off-campus master’s degree program to prepare nurse educators who would commit to remain in their home countries following graduation. The program was approved by the Western Association of Schools and Colleges to be offered in both English and Spanish. Students and faculty met for 1 month each year for 4 years at one of two international sites: Thailand or Argentina. Forty-five of 49 students completed the program. The cultural diversity in both cohorts enriched classroom discussions, social interaction, and student-faculty conversations. The program was a life-changing experience for all involved and helped to meet the global need for nursing faculty. The faculty reported that it broadened their world view and opened their minds to the potential for innovation to transform nursing education.
Scleral Dellen After Fibrin Glue Use in Strabismus Surgery
Authors: Basmak Hikmet , Erdogan Hakika , Sahin Afsun , Gürsoy Hüseyin
Published: July 2010

The authors report a case of scleral dellen occurrence after fibrin glue use in strabismus surgery. The complication was well managed and it may alert surgeons preferring fibrin glue for conjunctival closure to the possibility of scleral dellen occurrence.
Atypical Duane's Retraction Syndrome: Congenital Adduction Palsy With Synergistic Divergence in Association With Aberrant Trigeminal Innervation and Facial Hypoplasia
Authors: Gupta Malvika , Sethi Harinder Singh , Gupta Vishnu Swarup , Malik K.P.S.
Published: July 2010

The authors describe the atypical and unique features of trigeminal-oculomotor synkinesis in a 6-year-old boy with left congenital adduction palsy and synergistic divergence with facial hypoplasia. Adducting movements of the left eye were also seen on mastication. To the best of the authors' knowledge, a case of this nature has not previously been reported. This case illustrates the absence of changes in palpebral aperture and globe retraction on attempted adduction and also the complete absence of any abduction deficit of the involved eye. Additionally, presence of adducting movements on mastication suggests a trigemino-oculomotor synkinesis. Hypothesis favors an anomalous innervation of the medial rectus muscle from the motor branch of the trigeminal nerve that innervates the external pterygoids.
Reliability of the IOLMaster in Measuring Corneal Power Changes After Hyperopic Photorefractive Keratectomy
Authors: Rosa Nicola , De Bernardo Maddalena , Borrelli Maria , Filosa Maria Luisa , Minutillo Emma , Lanza Michele
Published: July 2010

Purpose:

To test the accuracy of the IOLMaster (Carl Zeiss Meditec) in detecting corneal power changes after hyperopic photorefractive keratectomy (PRK).

Methods:

Forty-five consecutive eyes that underwent hyperopic PRK with the SCHWIND ESIRIS excimer laser, ranging from +0.75 to +7.00 diopters (D) (mean: +3.84±1.56 D), were analyzed. Data included pre- and postoperative (1, 3, and 6 months) fogging refraction and automated keratometry (K). Statistical analysis was performed to determine the correlation between the changes in refraction at the corneal plane and the changes in keratometry.

Results:

The mean difference between the changes in refraction and the measured corneal changes was +0.27±1.19 D (range: −1.91 to +4.28 D) (
P
=.18) at 1 month; +0.56±0.97 D (range: −1.00 to +2.96 D) (
P
=.006) at 3 months; and +0.67±0.80 D (range: −0.73 to +2.31 D) (
P
=.00002) at 6 months. Based on these results, we suggest using the regression formula found at 6-month follow-up (y=0.8074 x + 0.092) to better calculate the effective corneal power. Comparison between the data obtained with IOLMaster measurements and equivalent K readings from the Holladay report obtained with the Pentacam (Oculus Optikgeräte GmbH) shows good agreement (R
2
=0.9).

Conclusions:

Automated keratometry provided by the IOLMaster underestimates the effective refractive changes after hyperopic PRK, and a correcting factor is needed to calculate the corneal power in these cases.
Refractive Stability of LASIK with the VISX 20/20 Excimer Laser vs ZB5M Phakic IOL Implantation in Patients with High Myopia (>−10.00 D): A 10-Year Retrospective Study
Authors: Rosman Mohamad , Alió Jorge L. , Ortiz Dolores , Pérez-Santonja Juan J.
Published: July 2010

Purpose:

To compare the long-term outcomes of LASIK and ZB5M phakic intraocular lens implantation (PIOL) (Domilens) for high myopia (>−10.00 diopters [D]).

Methods:

This long-term (10 years) follow-up retrospective interventional case series study included 126 eyes that underwent LASIK and 52 eyes that underwent ZB5M angle-supported PIOL implantation. Both groups of eyes were similar in terms of preoperative spherical equivalent refraction (SE), corrected distance visual acuity (CDVA), and age.

Results:

Mean preoperative SE was −14.33 D in the LASIK group and −14.84 D in the PIOL group. At 10-year follow-up, mean postoperative SE was −1.47±2.00 D in the LASIK group and −1.01±1.36 D in the PIOL group (
P
=.21). In the LASIK group, 67% of eyes were within ±1.00 D of emmetropia at 2 years after surgery, compared to 42% at 10 years. In the PIOL group, 68% of eyes were within ±1.00 D of emmetropia 2 years after implantation compared to 53% at 10 years. In the LASIK group, 43.5% of eyes achieved UDVA of 20/40 or better 10 years after surgery compared to 67.9% in the PIOL group (
P
=.02).

Conclusions:

The ZB5M angle-supported PIOL was shown to have better predictability and stability compared to LASIK over 10 years. However, reductions in endothelial cell count over time were observed in eyes with PIOLs.
Descemet’s Membrane Detachment Following Phacoemulsification
Authors: Sukhija Jaspreet , Ram Jagat , Kaushik Sushmita , Gupta Amod
Published: July 2010

Background and Objective:

To determine the management options and the indications for surgical intervention in Descemet’s membrane detachment (DMD) after phacoemulsification.

Patients and Methods:

Clinical records of 11 consecutive eyes (11 patients) with DMD were reviewed. All cases had undergone phacoemulsification with posterior chamber intraocular lens implantation. Patients with DMD involving one-third or more of the cornea were analyzed.

Results:

All patients underwent clear corneal phacoemulsification. In three cases where the detachment was recognized intraoperatively, perfluoropropane gas was injected. Eight eyes (8 cases) had unexpected corneal edema detected as DMD postoperatively and managed by injecting perfluoropropane gas into the anterior chamber. Three eyes that required repeated surgical intervention postoperatively had more than 50% corneal involvement with significant separation of the membrane from the stroma and curling or folding of the membrane. At last follow-up, 10 eyes retained clear corneas and one had residual DMD not involving visual axis. All 11 eyes had best-corrected visual acuity of better than 6/12.

Conclusion:

DMD should be suspected in patients showing unexpected corneal edema postoperatively who have undergone uneventful phacoemulsification and be treated in a timely manner. Surgical intervention is recommended in cases with significant separation of the membrane from stroma and curling or folding of the Descemet’s membrane.
Aportaciones al estudio reológico de pastas y morteros de cemento portland
Authors: Miranda J. , Flores-Ales V. , Barrios J.
Published: July 2010

The concrete could be considered as a thick solid particles suspension in fine particles suspension. The rhealogy of the last one influences very hardly the concrete behaviour, so that the importance to realize an study concerning the mortars and pastes rheology.
The first objective of this work has been to determine the more adequated rheometer to characterize this kind of samples, considering the difficulty of the rheologic study of high concentration suspensions who tends towards the development of shear phenomena in the walls of the sensor system. Between the equipments with placa-placa sensor, coaxial cylinders and helicoidal band shaker, the first ones were discarded due to the high relationship between particle diameter and measure cavity that makes de viscose properties scarcely repetitive, whereas the last set doesn´t present this problem, in view of which we choose to use it to the obtention of rheologic properties of the samples studied.
Secondly, we have try to describe the viscose behaviour of different pastes and mortars with different agregates and relations water/cement. For this purpose some sweeping of shake speed were realized as well as tests at constant speed, relating the viscosity evolution with the setting time.
The analyse of the rheologic behaviour is affected by the fact of applying a shake that conduces to the system break who tends towards to be structured during the setting time. This specificity concerning the time, joined with the heterogeneity of the samples, makes difficult to obtain results with a good repeatability.
Optical properties of vanadium dioxide thin film as a windows thermochromic coating
Authors: Wu Z. P. , Miyashita A. , Yamamoto S. , Nashiyama I. , Narumi K. , Naramoto H
Published: July 2010

The optical properties of vanadium dioxide (VO2) thin film have been studied for the potential application of intelligent windows. The results show that VO2 film deposited on sapphire substrates exhibits good thermochromic effects, its IR transmittance changes 60% before and after phase transition, and has less thickness dependence than UV transmittance. Doping can significantly reduce transition temperature, such as to 30°C for 1.5% Mo doped VO2.
Cleaning of stone materials in the Cathedral de Valladolid (Spain)
Authors: Fort R. , López de Azcona M. C. , Mingarro F.
Published: July 2010

Two types of black crusts showing gypsiferous and calcareous compositions are recognized on the front-walls of the Valladolid Cathedral. On the basis of several petrophysical parameters, in particular compacity, sorption and desorption kinematics of carbonate rocks used building the cathedral, we conclude that the most appropriate cleaning method of the ashlars is washing with water. Highest efficiency of the method is attained with water at 90ºC and at a pressure of 120 bars. This assessment is valid for most of the carbonate rocks of the cathedral except for detrital pelmicrites because of their low compacity which makes that water pressure for cleaning must not exceed 50 bars. The processing of cleaning with water should be preceded by alkaline treatment (NaOH and EDTA) of the rock surface.
Effect of pollutant gases on electrical insulators deterioration
Authors: Zamarad A. , Martínez-Ramírez S. , Thompson G. E. , Moore B. E.
Published: July 2010

In this work ceramic materials as electrical insulators have been exposed in laboratory-based chambers. Water contact angle and FTIR of the surface before and after pollutant exposures have been studied. The results indicated that the reaction between the policrete and the atmospheric pollutant produce some salts deposits, some hydrolysis over the resin surface, modifying water contact angle.
Influence of the metakaolin on porous structure of matrixes based in mk/cement
Authors: Frías M. , Sánchez de Rojas M. I.
Published: July 2010

The incorporation of pozzolanic materials in the manufacturing of blended cement has a positive effect on the improvement of blended mortar and concretes performances. These active additions modify porous structure, impeding or delaying the access of aggressive solutions and, therefore materials more durable are possible of obtaining.
An increase or decrease on the durability of blended pastes, mortars and concretes will depend on chemical and mineralogical compositions, fineness and reaction kinetics of these pozzolans.
The current work shows the results of a research carried out in blended pastes to know the effect of activated material (metakaolin) on the microporosity of pastes elaborated with different amounts of mk (0-25%). A water/ binder ratio of 0,55 was used. Samples were cured at 20ºC for 360 days.
The evolution of total, capilary and gel porosity as well as average pore size were carried out through mercury intrusion porosimeter (MIP). Also, the helium pycnometer as alternative method to obtain additional information about porosity above 1,4 Å was used.
A good correlation between both methods has been obtained. In addition, it is proposed the best mk content for the elaboration of mk-blended pastes.
Behaviour of alkaline cement mortars reinforced with acrylic and polypropylene fibres
Authors: Puertas F. , Amat T. , Vázquez T.
Published: July 2010

In the present work, the behaviour of alkaline cement mortars reinforced with fibres of different nature (acrylic and polypropylene fibres) is studied. Also the chemical stability of those fibres in strong alkaline medium has been investigated. Three different matrixes have been used: glass blast furnace slag activated with NaOH 2M (room temperature, 22 ºC); fly ash activated with NaOH 8M, cured at 85ºC during 24 hours and 50% fly ash / 50% slag activated with NaOH 8M, room temperature. The fibre content was 0,2 and 1% in mortar volume. The tests carried out were: tenacity and tenacity index, impact resistance and drying shrinkage. On the specimens tested, a microstructural study by SEM/EDX was carried out.
The results obtained have demonstrated the following: a) The acrylic and polypropylene fibres are stable in strong basic media, although the first undergo hydrolysis/ hydration processes showed by the alteration of the surface texture, b) with low fibre contents (0,2%) in volume), tenacity and tenacity index of these mortars remain unaffected. With higher contents (1%), an increase of the corresponding values is produced. This increment is higher in mortars with alkaline activated slag, c) For the three matrixes studied, the polypropylene fibres increase the impact strength in higher degree than the acrylic ones. The reinforcement effect is more significative in matrix A and when the fibre content is 1% in volume, d) the shrinkage of these mortars is modified depending on the matrix and fibre type. In mortars of activated slag, fibres do not reduce the shrinkage. In mortars of activated fly ash reinforced with acrylic fibres, shrinkage is lower than those containing polypropylene fibres are. Finally, in mortars of fly ash/ activated slag, the two fibres decrease the drying shrinkage.
Evaluation of treatment products for the front door of the church of Santiago, Guadix
Authors: Villegas-Sánchez R. , Espinosa Gaitán J.
Published: July 2010

In a previous article the materials and the state of conservation of the Front Door of the church have been characterized, with the aim of determining the causes and the alteration mechanisms that are present in it.
In the present work the behaviour of several treatments, water repellents and/or consolidants, is evaluated to determine their effectiveness and their answer to the weathering factors.
With this object, several characteristics of the stone, before and after the application of treatments, have been determined, as well as the weathering resistance that has been measured subjecting the samples to alteration tests that reproduce the observed weathering mechanisms, salt crystallization and freezing-thawing.
Alkaline activated slag cements. Determination of reaction degree
Authors: Fernández-Jiménez A. , Puertas F.
Published: July 2010

The aim of the present work was to evaluate the validity of non-calorimetric different methods, used in the determination of reaction degree of alkaline activated slag pastes. The methods used were: (a) chemical separation by methanol-salicylic acid; (b) determination of the weight loss mass between 100-600°C in TG curves, associated to chemically combined water; (c) quantification of the -74 ppm signal in 29Si MAS-NMR spectra.
The parameters considered in the process were: nature of the alkaline activator (Waterglass, Na2CO3 and NaOH), activator concentration (4% and 3% Na2O in mass with respect to the slag), curing temperature (25 and 45°C), slag specific surface (460 and 900 m2/kg) and time of reaction (from 7 days to 18 months).
The results obtained indicate that none of the three methods is definitive but complementary and they provide to follow the reactive evolution of the alkaline activated slag cements. The method based on the quantification of the -74 ppm signal in the 29Si MAS NMR is the most suitable method.
Relationship between flexural toughness energy and impact energy of high strength fiber reinforced concrete (HSFRC)
Authors: Marar Khaled , Eren Özgür , Çelik Tahir
Published: July 2010

A simple, economical and practical impact resistance test method has been developed for high strength fiber reinforced concrete (HSFRC). The results indicated that there is a logarithmic relation between flexural toughness energy (EFT) and impact energy (El) for FRC In this study, three different aspect ratios of hooked-end fibers, namely, 30/0.50; 60/0.80 and 50/0.60 length/diameter (mm/mm) were used. Fibers were added to concrete in four different volume percentages of 0.5, 1.0, 1.5 and 2.0 %. From the results it can be said that fibers in high strength concrete improve impact resistance and flexural toughness of concrete. Also a good correlation between flexural toughness energy and impact energy has been established.
Early hydration cement Effect of admixtures superplasticizers
Authors: Puertas F. , Vázquez T.
Published: July 2010

Early hydration of portland cement with superplasticizer admixtures of different nature has been studied. These admixtures were: one based on melamine synthetic, other based on vinyl copolymer and other based on polyacrylate copolymers. The dosage of the formers were constant (1% weigth of cement) and for the third, the influence of admixture dosage was also evaluated, giving dosage values among 1-0.3%. The pastes obtained were studied by conduction calorimetry, XRD and FTIR. Also the apparent fluidity was determined by "Minislump" test. The main results obtained were: a) superplasticizers admixtures used, regardless of their nature and for the polycarboxilate one the dosage, retard the silicate hydration (specially, alite phase), b) The ettringite formation is affected by the nature of the admixture. c)A relationship between the dosage of admixture based on polycarboxilates and the time at the acceleration has been established. A lineal relation (y = 11.03 + 16.05x) was obtained. From these results is possible to know, in function of dosage admixture, the time when the masive hydration products and the setting times are produced. Also the total heat releases in these reactions is independent of the nature and dosage of admixture, saying that in all cases the reactions are the same.
Slag founding: kinetic study and election of a grinding system
Authors: Salas Vinent M. E. , Rabilero Bouza A. C. , Córdova Rodríguez V.
Published: July 2010

Here we offer results obtained in laboratories and industry, concerning the kinetic study of steelfounding in cement manufacture. We choose the most suitable grinding system, valuing also its economical and environmental repercussion.
The obtained results indicated that the kinetic method is extremely useful to solve the practical problems in the conception and design of grinding systems, and it is also a speed and the inverted bolting-rell gap almost like a Arrhenius equation.
Fiftieth anniversary of the journal "Últimos Avances en Materiales de Construcción"
Authors: Calleja J.
Published: July 2010

The aim of the author is to present an historical survey of the birth, growth and development along the fifty years of the life of the scientific and technical magazine MATERIALES DE CONSTRUCCIÓN, mainly devoted to cement and concrete matters.
This has been intended in the present paper taking into account four periods of the mentioned life: "Prehistory" (Antecedents), "Protohistory" (The Journal) referred to The First Hundred Numbers of the Journal, "Modern History" dealing with The Second Hundred Numbers of it, and "Contemporary History", in which the present state of the Journal is described in brief.
The description has been carried out with an analytical and critical purpose, giving emphasis in it to all kind of aspects.
Objectivity in citing references
Authors: Neville A.
Published: July 2010

Not available
New advanced electrochemical techniques for on site measurements of reinforcement corrosion
Authors: Andrade C. , Martínez I. , Alonso C. , Fullea J.
Published: July 2010

Measurement techniques of reinforcement corrosion are scarcely researched if compared with the increasing number of publications in the subject. However, numerous possibilities and challenges remain without being explored. In present paper mention is made to some of the present possibilities of electrochemical techniques, either on-site or in the laboratory. Concerning on-site techniques it is commented the possibilities and limitations of present methods of measuring Polarization Resistance, Rp. Particular attention is given to the need to use a modulated guardring with sensors controlling this modulation to obtain accurate values of the corrosion rate. After, description of the basis of new techniques related to the measurements of the passivation state in cathodically protected structures, is made. The basis of a new method of measuring corrosion without the need to touch the metal is also presented. Regarding the use of embedded sensors, the experience until now shows the difficulty of interpretation of the data collected, due to the important influence of ambient temperature. Finally, some comments are presented on the need of joint work of material and structural specialists.
Carbonation of calcium aluminate cement pastes
Authors: Fernández-Carrasco L. , Puertas F. , Blanco-Varela M. T. , Vázquez T.
Published: July 2010

This work discusses the results from accelerated tests intended to investigate the ways the different curing methods affect the carbonation of calcium aluminate cements pastes (CAC). The research was focused on the mineralogical composition of hydrated and carbonated samples. The compressive strengths and the porosity of the samples have been determined.
Results point out that vaterite and aragonite are formed as a result of carbonation of both cubic and hexagonal calcium aluminate hydrates. The polymorph of calcium carbonate formed does not depend on the curing process. Carbonation rates is higher in hexagonal than in cubic hydrates. Results obtained through this study evidence that, as a consequence of the carbonation process of CAC pastes, in test conditions, an increase of the mechanical strengths occurs.
Role of clay constituents in stone decay processes
Authors: Veniale F. , Setti M. , Rodríguez-Navarro C. , Lodola S.
Published: July 2010

Stone alterability/durability is depending upon a number of intrinsic and extrinsic factors among which "clay minerals" constituents, either diffused throughout the stone framework or as coating-filling of void spaces, can play an important role.
Swelling-shrinking and aggregation-disaggregation phenomena occurring by interaction of argillaceous particles with water and other fluids can cause destructuration of the stone resulting in a variety of pathologies. Also salt crystallization which is depending on fluid transfer, moisture evaporation and ion concentration in the circulating solutions, can be influenced by clay mineral reactivity. Furthermore, saline solutions can drastically change the clay minerals behaviour, resulting in enhanced "osmotic" swelling and variations in clay aggregation geometry; these phenomena resulting in significant stone damage.
Case histories concerning several lithotypes used for monumental buildings and artistic manufacts are reported for showing the role of different clay mineral types in determining trend and intensity of decay processes.
Structure of aluminosilicate melts produced from granite rocks for the manufacturing of petrurgical glass-ceramics construction materials
Authors: Simakin A. G. , Salova T. P. , Romero M. , Rincón J. M.
Published: July 2010

The aluminosilicate melt is a partly ordered phase and is the origin of glass for producing glassceramics and petrurgical materials. They are well extended used as construction materials for pavings and coatings. Its structure can be described in the terms of the aluminosilica tetrahedras coordination so-called Q speciation. The proportions of tetrahedra with different degree of connectivity with others (from totally connected to free) has been studied by NMR and IR methods for sodium-silicate melts. Medium range structure can be characterized by the sizes of irreducible rings composed of the aluminosilica tetrahedra. Systematic increase of the four member rings proportion in the sequence of the Ab-An glasses were observed. The water dissolution in sodium-silicate glass affects the Q speciation. Cations network-modifiers positions in the melt structure are important to know since these cations stabilize particular structure configurations. Modification of the distribution of Na coordination in the sodium-silicate glass at water dissolution was determined by NMR spectroscopy. The observed modification of the hydrous aluminosilicate melt structure resulted in the shift of the eutectic composition in the granite system with decreasing of the crystallization field of feldspars. The feldspar growth rates show practically no dependence on the water content in the concentration range 2-4 wt.%. Likewise, the solved water has a little influence on the crystal growth rate of the lithium silicate phase in lithium containing glasses in accordance with estimated enhancing of the diffusion transport.
Influence of relationship water/cement upon the processing of cements with pozzolana in standard mortar
Authors: Gener Rizo M. , Álvarez Cabrera J. L.
Published: July 2010

The processing of standard mortar is completed following different methods in accordance with the country, but they exist two fundamental tendecies, the ISO and the ASTM. The cuban norm for mechanic-physic tests is based in ISO, and so they use a constant relationship water/cement in the processing of standard mortar a great problem concerning the cement users when they tested those mixed with puzzolanes, because they don't take care of the bigger water needs of those materials.
In this work we present an study of the behaviour of Pozzolanic Portland cements (PP-250) elaborates with a fix and changeable relationship water/cement, obtained starting from the fluidity of the pure Portland cement.
(P-350) The results obtained shows that the mechanical resistance decreased in cement mortars PP-250 realised with changeable relationship water/cement. So we recommend the adoption of an optional procedure to elaborate a quality mortar with pozzolana cements.