bluuebunny/crossref_metadata_2025 huggingface dataset:
Improvement in recovery after experimental intracerebral hemorrhage using a selective cathepsin B and L inhibitor
Authors: Yang Dongmei , Han Yuxia , Zhang Jianfeng , Ding Christopher , Anagli John , Seyfried Donald M.
Published: July 2010

Object

This study investigates a potential novel application of a selective cathepsin B and L inhibitor in experimental intracerebral hemorrhage (ICH) in rats.

Methods

Forty adult male Wistar rats received an ICH by stereotactic injection of 100 μl of autologous blood or sham via needle insertion into the right striatum. The rats were treated with a selective cathepsin B and L inhibitor (CP-1) or 1% dimethyl sulfoxide sterile saline intravenously at 2 and 4 hours after injury. Modified neurological severity scores were obtained and corner turn tests were performed at 1, 4, 7, and 14 days after ICH. The rats were sacrificed at 3 and 14 days after ICH for immunohistological analysis of tissue loss, neurogenesis, angiogenesis, and apoptosis.

Results

The animals treated with CP-1 demonstrated significantly reduced apoptosis as well as tissue loss compared with controls (p < 0.05 for each). Neurological function as assessed by modified neurological severity score and corner turn tests showed improvement after CP-1 treatment at 7 and 14 days (p < 0.05). Angiogenesis and neurogenesis parameters demonstrated improvement after CP-1 treatment compared with controls (p < 0.05) at 14 days.

Conclusions

This study is the first report of treatment of ICH with a selective cathepsin B and L inhibitor. Cathepsin B and L inhibition has been shown to be beneficial after cerebral ischemia, likely because of its upstream regulation of the other prominent cysteine proteases, calpains, and caspases. While ICH may not induce a major component of ischemia, the cellular stress in the border zone may activate these proteolytic pathways. The observation that cathepsin B and L blockade is efficacious in this model is provocative for further investigation.
Crossed aphasia elicited by intraoperative cortical and subcortical stimulation in awake patients
Authors: Vassal Matthieu , Le Bars Emmanuelle , Sylvie Moritz-Gasser S.T. , Menjot Nicolas , Duffau Hugues
Published: July 2010

Object

Crossed aphasia (aphasia resulting from a right hemispheric lesion among right-handed patients) is rare. The authors describe for the first time transient crossed aphasia elicited by intraoperative electrostimulation of both cortex and white matter pathways in awake patients.

Methods

Three right-handed adults underwent surgery for a right-sided glioma. Because slight language disorders occurred during partial seizures or were identified on preoperative cognitive assessment, with right activations detected on language functional MR imaging in 1 patient, awake craniotomy was performed using intraoperative cortico-subcortical electrical functional mapping.

Results

Transient language disturbances were elicited by stimulating discrete cortical areas (inferior frontal gyrus and posterior part of the superior temporal gyrus) and white matter pathways (inferior frontooccipital fasciculus and arcuate fasciculus). A subtotal resection was achieved in all cases, according to functional boundaries. Postoperatively, 1 patient experienced a transient dysphasia, which resolved after speech rehabilitation, with no permanent deficit.

Conclusions

These original findings highlight the possibility of finding crucial cortico-subcortical language networks in the right hemisphere in a subgroup of atypical right-handed patients. These findings provide new insights into the neural basis of language, by underlining the role of the right inferior occipitofrontal fasciculus in semantics and that of the right arcuate fasciculus in phonology, and by supporting the hypothesis of a mirror organization between the right and left hemispheres. The authors suggest that, in right-handed patients, if language disturbances are detected during seizures or on presurgical neuropsychological assessment, especially when right activations are observed on language functional MR imaging, awake craniotomy with intraoperative language mapping should be considered.
Synthesis and Properties of 1,8-Carbazole-Based Conjugated Copolymers
Authors: Michinobu Tsuyoshi , Osako Haruka , Shigehara Kiyotaka
Published: July 2010

A new series of conjugated carbazole polymers based on the 1,8-carbazolylene unit was synthesized by the Pd-catalyzed polycondensation between the 1,8-diiodocarbazole derivative and various bifunctional counter comonomers. An alkyne spacer was found to be a key to increasing the molecular weight of the resulting polymers. All the obtained polymers showed good solubilities in the common organic solvents, and they were fully characterized by Gel permeation chromatography (GPC), and 1H NMR and infrared (IR) spectroscopies. The UV-vis absorption and fluorescence spectra revealed the relationship between the chemical structure and effective conjugation length. The efficiency order of the carbazole connectivity was 2,7-carbazolylene > 1,8-carbazolylene > 3,6-carbazolylene. The electrochemical properties of these polymers suggested the relatively facile oxidation at ca. +0.5–0.7 V vs. Fc/Fc+ or a high potential as p-type semiconductors. The combination of the electrochemical oxidation potentials and the optical band gaps allowed us to estimate the HOMO and LUMO levels of the polymers. It was shown that the energy levels of the 1,8-carbazole-based conjugated polymers can be tunable by selecting the appropriate comonomer structures.
Correlating Multimodal Physical Sensor Information with Biological Analysis in Ultra Endurance Cycling
Authors: May Gregory C. , Doherty Aiden R. , Smeaton Alan F. , D.Warrington Giles
Published: July 2010

The sporting domain has traditionally been used as a testing ground for new technologies which subsequently make their way into the public domain. This includes sensors. In this article a range of physical and biological sensors deployed in a 64 hour ultra-endurance non-stop cycling race are described. A novel algorithm to estimate the energy expenditure while cycling and resting during the event are outlined. Initial analysis in this noisy domain of “sensors in the field” are very encouraging and represent a first with respect to cycling.
Drawing from the Outside for Support in Teaching
Authors: Eifler Karen E. , Veltri Linda M.
Published: July 2010

Mentoring new nurse educators in their pedagogy is vital to their long-term success and their students’ learning. It is also crucial to build mentoring into ongoing professional development plans because doctoral studies rarely include information on how to be an effective teacher. An overlooked resource on college campuses is the education department. This article describes the processes of a fruitful 2-year mentoring relationship between a new nurse educator and an education professor and offers a virtually no-cost strategy for improving the quality of teaching in schools, departments, and colleges of nursing. Using education faculty as mentors has two advantages over using fellow nursing faculty: pedagogy is their absolute professional expertise and the relationship may be less fraught with the potential baggage of peer evaluation because the mentors and mentees are in different departments. Trust, open communication, and clear goal-setting establish the framework for successful mentoring relationships.
Embracing Multiculturalism in Nursing Learning Environments
Authors: Ackerman-Barger Piri W.
Published: July 2010

This article outlines the disparities that exist in educational opportunities for ethnic minorities in both higher education and nursing programs. Barriers exist for ethnic minorities that are directly related to students’ circumstances and factors related to faculty and universities. There are multiple strategies that can be implemented by faculty and universities to ameliorate inequities in education, but they are most meaningful when institutions use self-reflection and plan for long-term sustainable changes.
A Mentor-Protégé Program for New Faculty, Part I: Stories of Protégés
Authors: White Anne , Brannan Jane , Wilson Carol B.
Published: July 2010

With the projected shortage of nursing faculty, formalized programs are needed to provide mentorship programs that will encourage and support faculty as they move from the role of novice to expert educator. The purpose of this qualitative study is to explore the experience of protégés participating in a mentorship program for novice faculty. An interpretive phenomenological research study was conducted to illuminate the meaning of the experiences of the protégés participating in the program. The study of the experience of protégés participating in a mentor-protégé program led to the emergence of three main themes: Creating a Meaningful Mentor-Protégé Relationship, Transitioning as a New Nurse Educator, and the Mentor-Protégé Program—Lessons Learned. Data from the study will provide insight into the meaning of receiving mentorship in the role of novice nurse educator.
Are Most Sixth Nerve Palsies Really Paralytic?
Authors: Altintas Ayse Gul , Arifoglu Hasan Basri , Dal Derya , Simsek Saban
Published: July 2010

Background:

Etiology and date of palsy are two important parameters that affect the treatment protocol of sixth nerve palsies. This study evaluated the treatment protocols and outcomes of treatment in sixth nerve palsies.

Methods:

Thirty-four patients who had sixth nerve palsy were included. Botulinum toxin A (BTX) injection was performed on patients with acute sixth nerve palsy and paresis (BTX group), whereas chronic cases received only horizontal surgery (surgery group). All patients in the BTX group received a BTX injection into the ipsilateral medial rectus muscle. Patients in the surgery group underwent either ipsilateral medial rectus recession or recession combined with lateral rectus resection without the transposition procedure.

Results:

Fifteen patients were treated with a BTX injection to the medial rectus muscle. One patient underwent ipsilateral medial rectus muscle recession and 6 patients received both medial rectus recession and lateral rectus resection in the same session. Measurement of esotropia was 24.9 prism diopters (PD) (range: 18 to 35 PD) before treatment in the BTX group. The recovery rate was 86.6% (13 of 15) without any residual deviation. In the surgery group, the mean preoperative deviation was 35.1 PD (range: 14 to 75 PD), which decreased to mean 2.57 PD (range: 0 to 10 PD) postoperatively. The achievement of orthotropia rate was 85.7%.

Conclusion:

BTX injection was found to be an effective treatment because it prevented medial rectus contraction in acute sixth nerve palsies. Correction of deviation with the recession of contracted medial rectus muscles and resection of lateral rectus muscles without the need of transposition in chronic sixth nerve palsy testified that most sixth nerve palsies involve partial paralysis rather than complete paralysis.
Outcomes of Surgery in Long-Standing Infantile Esotropia with Cross Fixation
Authors: Keskinbora Kadircan H. , Gonen Tansu , Horozoglu Fatih
Published: July 2010

Background:

This is a retrospective study to determine the outcomes of the surgical correction in long-standing infantile esotropia with cross fixation.

Methods:

Medical charts of a group of patients with esotropia who had cross fixation and underwent surgery for strabismus between January 1991 and December 2004 were reviewed. The mean follow-up time was 4.7 years. Binocularity was measured by the Worth 4-dot test and Titmus stereo test. Twenty-six patients underwent surgery for strabismus. Twenty-one patients aged 8 to 26 years with a minimum 3-year postoperative follow-up were included. Five patients were excluded because they were lost to follow-up after surgery.

Results:

Bimedial recession and resection of one lateral rectus muscle were performed in all patients. Recession of the inferior oblique muscle with anteriorization was performed in patients who had inferior oblique overaction. Orthotropia was attained in 14 patients, whereas residual esotropia was diagnosed in 5 patients. Two patients were diagnosed as having exotropia. Two patients required a second surgery for dissociated vertical deviation. Overall, 9 of the 21 patients had indications of binocular function and 12 remained the same in their stereoacuity.

Conclusion:

Surgical correction of long-standing infantile esotropia with cross fixation in young adults may improve binocular function and allow long-term alignment stability.
Strabismus in Pediatric Lens Disorders
Authors: Spanou Nomiki , Alexopoulos Lampros , Manta Georgia , Tsamadou Despina , Drakos Hristos , Paikos Petros
Published: July 2010

Purpose:

To evaluate the prevalence and types of strabismus in children with cataract and ectopia lentis.

Methods:

The authors retrospectively evaluated 860 children treated in the ophthalmological department of Children’s Hospital “Agia Sophia” during the past decade. Their medical files with reference to strabismus prevalence, correlation between the time of strabismus occurrence and lens extraction surgery, and type of strabismus were studied.

Results:

Of the 822 children with cataract, 337 had congenital cataract and 485 had acquired cataract. Strabismus occurred in 199 (24.2%) patients; 113 (56.8%) patients had esotropia and 86 (43.2%) patients had exotropia. Of the 38 children with ectopia lentis, strabismus occurred in 5 (13.2%); 1 patient had esotropia and 4 patients had exotropia. There is no significant difference in the time of appearance of strabismus in relation to the cataract operation, whereas there is a significant difference in ectopia lentis, although this may be a result of the small sample size. The incidence of strabismus is higher in patients with unilateral cataracts (27.4%) than in those with bilateral cataracts (19.6%). Strabismus occurred more frequently in patients with congenital cataracts (30.3%) than in acquired cases (20%), with esotropia being more common in congenital cataracts (76.5%) and exotropia more common in acquired cataracts (63.9%).

Conclusion:

The authors believe it is imperative that great attention should be given to ocular alignment in addition to management of refractive error and intense amblyopia therapy during long-term follow-up.
Posterior Corneal Elevation After LASIK with Three Flap Techniques as Measured by Pentacam
Authors: Grewal Dilraj S. , Brar Gagandeep S. , Grewal Satinder Pal Singh
Published: July 2010

Purpose:

To evaluate and compare posterior corneal changes using elevation data obtained from Pentacam (Oculus Optikgeräte GmbH) Scheimpflug imaging in eyes undergoing LASIK with three different modes of flap creation: IntraLase femtosecond laser FS60 (Abbott Medical Optics) (femtosecond group), Amadeus (Ziemer Group AG) mechanical microkeratome (keratome group), or flap formation using 20% alcohol laser epithelial keratomileusis (LASEK) (LASEK group).

Methods:

Ninety myopic patients (90 eyes) undergoing refractive surgery were recruited. The change in posterior corneal elevation at 21 predetermined points in the central 5-mm area was measured using exported elevation data from the Pentacam before LASIK and 18 months postoperative and was compared among and within three modes of flap creation.

Results:

Mean change in posterior elevation in the central 5-mm area was 5.13±4.16 μm for the femtosecond group, 5.78±4.42 μm for the keratome group, and 6.68±4.72 μm for the LASEK group and was similar among groups (
P
=.59). Change in posterior elevation before and after LASIK was not significant within any group (
P
=.342,
P
=.232, and
P
=.321 for the femtosecond, keratome, and LASEK groups, respectively). Preoperative spherical equivalent, central corneal thickness, ablation depth, and estimated residual bed thickness did not correlate with change in posterior corneal elevation for the femtosecond, keratome, or LASEK groups (
P
>.05).

Conclusions:

Using Pentacam elevation data, there were no significant changes in posterior corneal elevation following LASIK among or within the three methods of flap creation. At 18 months after LASIK, the posterior corneal surface is not displaced anteriorly significantly and is equally stable using these three surgical techniques.
Corneal Density with the Pentacam After Photorefractive Keratectomy
Authors: Takacs Agnes I. , Mihaltz Kata , Nagy Zoltan Z.
Published: July 2010

Purpose:

To measure corneal density and evaluate corneal haze in unoperated eyes and in eyes after photorefractive keratectomy (PRK).

Methods:

Forty-nine patients (91 eyes) who underwent PRK and 48 control patients (76 unoperated eyes) were measured with the densitometry program of the Pentacam Scheimpflug imaging system (Oculus Optikgeräte GmbH) (0=no clouding, 100=tissue completely opaque). Eyes were categorized as myopic or hyperopic (myopia group and hyperopia group), with subgroups defined as unoperated (unoperated myopia group and unoperated hyperopia group), postoperative clear corneas (clear cornea myopia group and clear cornea hyperopia group), and postoperative with haze (myopia haze group and hyperopia haze group). The ANOVA option of the Statistica 8.1 program package (StatSoft Inc) was used to compare subgroups.

Results:

Maximum density of postoperative corneas with haze (myopia haze group, 46.2±16.2; hyperopia haze group, 50.2±25.8) was higher than in postoperative clear corneas (clear cornea myopia group, 29.9±8.7; clear cornea hyperopia group, 22.9±3.1), but maximum corneal density in the latter subgroups showed no difference compared with unoperated controls (unoperated myopia group, 25.1±2.4; unoperated hyperopia group, 22.8±3.2). Differences among subgroups were not found outside the 6-mm diameter ablation zone. In hazy myopic corneas, there was a strong decreasing density trend from the apex to the 3-mm radius (
P
<.001, R=−0.5), which continued towards the periphery at 4.5 mm (
P
=.019, R=−0.21). Hyperopic mild hazy corneas showed a density increase from the apex to 3 mm (
P
<.001, R=0.4), followed by a decrease towards the periphery (
P
<.01, R=−0.4).

Conclusions:

The densitometry program of the Pentacam can provide a useful objective measure of postoperative and other mild corneal haze.
Prospective, Contralateral Comparison of 120-μm and 90-μm LASIK Flaps Using the IntraLase FS60 Femtosecond Laser
Authors: Moshirfar Majid , Hatch Bryndon B. , Chang JoAnn C. , Kurz Christopher J. , Eugarrios Marcela F. , Mifflin Mark D.
Published: July 2010

Purpose:

To compare differences in visual acuity, contrast sensitivity, higher order ocular aberrations, quality of life, and patient-reported outcomes at 3 and 6 months postoperatively in eyes with stable myopia undergoing thin-flap (intended flap thicknesses of 120 or 90 μm) LASIK using the VISX Star S4 CustomVue excimer laser (VISX Inc), with flaps created by the IntraLase FS60 femtosecond laser (Abbott Medical Optics).

Methods:

In this prospective study, thin-flap LASIK was performed contralaterally on 94 eyes: 47 eyes with 120-μm intended flap thickness and 47 eyes with 90-μm intended flap thickness. Primary outcome measures were uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), contrast sensitivity, and higher order aberrations.

Results:

At 6 months, mean values for UDVA (logMAR) were −0.064±0.077 and −0.051±0.070 in the 120-μm and 90-μm groups, respectively (n=40,
P
=.431). Visual acuity of 20/20 was achieved in 98% of eyes with 120-μm flaps and 95% of eyes with 90-μm flaps, whereas 20/15 vision was achieved in 50% of eyes with 120-μm flaps and 45% of eyes with 90-μm flaps (
P
≥.454). Both groups had significant increases in total higher order aberrations (
P
≤.003). Significant differences were not found between groups in contrast sensitivity (
P
≥.258), CDVA (
P
≥.726), total higher order aberrations (
P
≥.477), or patient-reported outcomes (
P
≥.132). Patients in both groups reported increased quality of life postoperatively (
P
≤.002).

Conclusions:

Under well-controlled surgical conditions, thin-flap LASIK achieved similar results in visual acuity, contrast sensitivity, and low induction of higher order aberrations in eyes with intended flap thicknesses of either 120 or 90 μm.
Optical Quality in Eyes Implanted with Aspheric and Spherical Intraocular Lenses Assessed by NIDEK OPD-Scan: A Randomized, Bilateral, Clinical Trial
Authors: Santhiago Marcony R. , Netto Marcelo V. , Barreto Jackson , Gomes Beatriz A.F. , Oliveira Cristiane D. , Kara-Junior Newton
Published: July 2010

Purpose:

To determine whether implantation of an intraocular lens (IOL) with an aspheric surface (Akreos AO, Bausch & Lomb Inc) results in reduced ocular aberrations (spherical aberration) and improved Strehl ratio and modulation transfer function (MTF) after cataract surgery.

Methods:

In an intraindividual, randomized, double-masked, prospective study of 50 eyes (25 patients) with bilateral cataract, an IOL with modified anterior and posterior surfaces (Akreos AO) was implanted in one eye and a biconvex IOL with spherical surfaces (Akreos Fit, Bausch & Lomb Inc) implanted in the fellow eye. Ocular aberrations, Strehl ratio, and MTF curve with 4.5-, 5.0-, and 6.0-mm pupils were measured with a NIDEK OPD-Scan dynamic retinoscopy aberrometer 3 months after surgery. Uncorrected and corrected distance visual acuity (UDVA and CDVA, respectively) were also measured.

Results:

No statistically significant difference was noted between eyes in postoperative UDVA and CDVA at 1 month. At 3 months, the Akreos AO IOL group obtained statistically significant lower values of higher order and spherical aberrations with 4.5-, 5.0-, and 6.0-mm pupil diameters than the Akreos Fit IOL group (
P
<.05). The value of Strehl ratio was statistically significantly higher in eyes with the Akreos AO IOL for 4.5- and 6.0-mm pupils (
P
<.05). The MTF curve was better in the Akreos AO IOL group in 4.5-, 5.0-, and 6.0-mm pupils (
P
<.05).

Conclusions:

The aspheric Akreos AO IOL induced significantly less spherical aberration than the Akreos Fit IOL for 4.5-, 5.0-, and 6.0-mm pupils. Modulation transfer function and Strehl ratio were also better in eyes implanted with the Akreos AO IOL than the Akreos Fit.
Trainee Glaucoma Surgery: Experience with Trabeculectomy and Glaucoma Drainage Devices
Authors: Connor Michael A. , Knape Robert M. , Oltmanns Matthew H. , Smith Mary Fran
Published: July 2010

Background and Objective:

To examine outcomes of trabeculectomy with mitomycin C and glaucoma drainage device placement for uncontrolled glaucoma when performed by resident surgeons.

Patients and Methods:

This study included any patient who underwent a trabeculectomy with mitomycin C (n = 93) or a glaucoma drainage device (n = 60) by a resident surgeon between 2001 and 2006. Outcome measures at 3, 6, and 12 months included failure of treatment, number of follow-up appointments, complications, number of medications, and need for further surgery.

Results:

One year postoperatively, intraocular pressure averaged 12.1 ± 5.1 mm Hg in the trabeculectomy group and 13.0 ± 5.1 mm Hg in the glaucoma drainage device group (
P
= .31). Complications occurred in 30% of eyes with trabeculectomy and 10% of eyes with a glaucoma drainage device.

Conclusion:

During the first postoperative year, glaucoma drainage device surgery may have fewer complications and less morbidity than a trabeculectomy with mitomycin C when these surgeries are performed by resident surgeons. Final intraocular pressures were similar between the two groups.
Posterior Segment Ophthalmic Complications of Aplastic Anemia
Authors: Agarwal Monica , Yeh Steven , Faia Lisa J. , Bishop Rachel J. , Lai Michael M. , Pantin Jeremy , Scheinberg Phillip , Chew Emily Y. , Weichel Eric D.
Published: July 2010

Three patients with aplastic anemia were evaluated by the ophthalmology service within 2 months of the aplastic anemia diagnosis for bilateral visual loss. The mean age of diagnosis of aplastic anemia was 14.3 years (range: 5 to 19 years) and the mean follow-up was 25 months (range: 15 to 44 months). All 6 eyes demonstrated choroidal ischemia and vitreous hemorrhage. Pars plana vitrectomy was performed in four eyes of two patients for non-clearing vitreous hemorrhage; one patient was observed. Successful anatomic outcomes were achieved in 3 of 4 eyes that underwent vitrectomy. Initial visual acuity ranged from 20/80 to bare light perception and final visual acuity ranged from 20/20 to no light perception. All patients received immunosuppressive therapy including cyclosporine and anti-thymocyte globulin, and two underwent hematopoietic stem cell transplantation. All patients received perioperative platelet and blood transfusions. Pars plana vitrectomy resulted in functional and anatomic success in the majority of eyes in this series. Coordination of medical and surgical care with the hematology service is advisable to stabilize hematologic parameters prior to undertaking a vitreoretinal procedure.
Acute Postoperative Endophthalmitis in a Patient with Darier’s Disease
Authors: Chappelow Aimee V. , Kosmorsky Gregory , Lewis Craig , Perry Julian D.
Published: July 2010

A 58-year-old man with Darier’s disease developed endophthalmitis 3 days following left-sided cataract extraction with intraocular lens implantation. Vitreous cultures were positive for
Pseudomonas aeruginosa
, similar to previously cultured hyperkeratotic plaques on the patient. Despite emergent vitrectomy and aggressive treatment with systemic, intravitreal, and topical fortified antibiotics, the patient required evisceration 19 days postoperatively. Bacterial overgrowth within hyperkeratotic plaques may increase the risk of endophthalmitis following intraocular surgery in patients with Darier’s disease.
Characterization of ancient construction materials (mud walls and adobe) in the churches at Cisneros, Villada and Boada de Campos (Palencia)
Authors: Sánchez Hernández R. , Suárez Barrios M. , Martín Pozas J. M.
Published: July 2010

The aim of this work is to characterize the ancient building materials (mud wall and adobe) of three churches in the province of Palencia. This is the first part of a study which seeks to evaluate how the mud walls of the tower of the church of Cisneros reacted to restoration treatment which consisted of a structural reinforcement made by injecting a highly fluid grout of cement/lime/sand mortar. This treatment implies the introduction of large quantities of water into the fabric.
The mud walls of the tower of Cisneros are compositionally and texturally very similar to each other, which indicates that despite their large dimensions, care was taken in the homogeneity of the materials. These mud walls are also very similar to those of the church of Villada. The original raw material is mud with some additives (rubble, ashes, bones, etc.) and some remains of lime used as a stabiliser. Although there is a very high proportion of clay, no effervescing clay has been detected. Hence it is deduced that once the mud wall was built, there were no important changes in volume due to variation in the humidity of the fabric.
The characteristics of the adobe of the tower of Boada are logically different form those of the mud walls, being made of less sandy, more clayey mud with a high proportion of straw that the mud walls do not have, and without the addition of bricks, bones, etc.
Comparaison de l'altérabilité au brouillard salin des deux pierres calcaires de construction au moyen des mesures pondérales acoustiques et par traitement d'images
Authors: Birginie J. M. , Rivas T. , Prieto B. , Auger F.
Published: July 2010

Not available
Studies about the heat of hydration developed in mortars with natural and by-product materials
Authors: Sánchez de Rojas M. I. , Frías M. , Rivera J.
Published: July 2010

The heat of hydration developed in reactions of mortars and concretes can be sensibly reduced using pozzolanic materials. However, the decrease of the heat of hydration is not directly proportional to the amount of cement substituted, because of the heat released in the pozzolanic reaction. With materials of high pozzolanic activity as silica fume or opaline rocks very, the heat is even increased.
Research about the pozzolanic activity of waste materials from calcined clay
Authors: Sánchez de Rojas M. I. , Frías F. , Rivera J. , Escorihuela M. J. , Marín F. P.
Published: July 2010

To recycle and reutilise waste materials and find definite applications for their use, it is necessary to have a deep knowledge of them.
The aim of this study is to study the possibility of using waste materials from calcined clay, actually ceramic tile, once crushed and grounded, as pozzolanic material. For this purpose, different tests are carried out in order to establish the pozzolanic activity of this material. At the same time, these results are compared to those of other industrial by-products, fly ash and silica fume, which are pozzolanic materials usually employed to elaborate mortars and concretes.
Prevention and curing of efflorescences in the restoration of bricks construction
Authors: Rincón J. M. , Romero M.
Published: July 2010

After description of basic principles of efflorescent effect in bricks in a former published paper, where the classification and examples of efflorescences were given, here are shown the methods for prevention and techniques for curing of this pathology. Some comments about Standards are included as well as very briefly the effect of gases in dryers and furnaces of efflorescences in clay products. The knowledgement of methods for prevention and curing of this pathology are very useful not only in the cleaning of modern fabrics made of bricks, but also in the Restoration of ancient buildings.
Durability of compressed soil-cement bricks
Authors: Acosta Valle A.
Published: July 2010

This papers shows the evaluation process of the durability of compressed soil-cement bricks. A great number of tests were made to determine the behavior of bricks when they are compression loaded and under the influence of moisture. Two different types of soils were used to produce the bricks, a lime-clay soil and a sand one. The sand soil is very resistant. The other one has a limited use.
An experimental design was used to test the bricks. It is a rotational and quadratic method with a hexagonal figure which contains replicas at the central point. This method ensures the reliability of test results. Otherwise, it would reduce the amount of specimens necessary for the tests. The optimun moisture content is obtained by using a press machine. It is more rational than the standard Proctor compactation test, because it applies the same type and amount of energy used to produce the bricks.
The obtained results show the behavior differences between the two compressed soil-cement bricks subjected to the compression test, water absorption and wetting and drying tests. The durability tests results are very important in the possible use of the bricks produced.
Influence of water-repellent treatment on the properties lime and lime pozzolan mortars
Authors: Fortes Revilla C. , Blanco Varela M. T.
Published: July 2010

The influence that water-repellent products can have on physical and micro-structural properties of lime mortars, and lime plus pozzolan mortars has been studied. Three water repellent products have been used. Mixes of the previously mentioned three water repellents plus a biocide product were also applied. Treatments make the total porosity and saturation coefficient of both mortars to decrease, while colorimetric coordinates bear little alteration. All treatments with water repellent products provided mortars with a hydrophobic property index close to 100%. Durability of such mortars has been also studied: salt crystallization test, frost-thaw and dry-wet cycles, as well as ultraviolet radiation test were carried out. Relationship between mortars behavior and their porosity and saturation coefficient were found.
Secondary raw materials for synthesising new kind of cements
Authors: Goñi S. , Guerrero A. , Macías M. A. , Peña R. , Fernández Escalante E.
Published: July 2010

The present paper is a comparative study of some characteristics of new belite cements obtained from two kind of wastes, which were used as secondary raw materials: fly ash (FA), of low CaO content, from coal combustion, and ash from incineration of municipal solid waste (MSWIA). Cements were synthesised in a range of temperature between 700°C and 900°C from MSWIA and FA, which were previously activated by hydrothermal treatment at 200°C The evolution of cemented phases with the heating temperature was followed by X-ray diffraction (XRD). The results were compared with those obtained from heating the starting FA and MSWIA without the previous hydrothermal treatment. The degree of hydration was quantitatively evaluated by the combined water content, determined from thermogravimetric analyses, during a period of 28 days or 200 days from mixing depending of hydration kinetics of each cement.
Thaumasite formation in hydraulic mortars by atmospheric SO2 deposition
Authors: Blanco-Varela M. T. , Aguilera J. , Martínez Ramirez S. , Palomo A. , Sabbioni C. , Riontino C. , Zappia G. , Van Valen K. , Toumbakari E. E.
Published: July 2010

Sulphation of mortars and concretes is a function of diverse environmental factors (SO2 aerosol, temperature, etc) as well as some material characteristics. One of the phases that could be formed as consequence of the sulphation of the hydraulic binder is thaumasite. In this paper different hydraulic mortars have been exposed to laboratory exposure chambers in order to reproduce thaumasite formation due to atmospheric SO2. Under the laboratory exposure conditions, thaumasite was formed in hydraulic lime mortars, and mortars elaborated with ordinary Portland cement as well as mineralized white portland cement. However, thaumasite was not formed in mortars made of lime and pozzolan. The first product formed as a result of the SO2-mortar interaction was gypsum. Gypsum reacted with calcite and C-S-H gel, present in the samples, giving place to thaumasite. Low temperature promotes thaumasite formation.
Reactivity and expansion of electric arc furnace slag in their application in construction
Authors: Vázquez Ramonich E. , Barra M.
Published: July 2010

EAF-slag have adequate technical properties for its use as aggregates. The MgO content is the main responsable of the expansions. The expansion produced affect in different way the new material depending of the rigidity of the matrices formed. EAF-slag shows hidraulicity and forms as reaction products CSH, calcium aluminiunsilicates and amorphous phases that can increase the strength of concretes containing slags. The Le Chatelier , autoclave expansion and volume expansion tests can not be used in detecting the potential expansion of slag when used as aggregate in rigid matrix (concrete). Two new methods of measuring the potential expansion of EAF-slag are proposed.
Determination of the OH- Content in the aqueous phase of hardened cementitious materials by an empirical Leaching method
Authors: Castellote M. , Alonso M. C. , Andrade C.
Published: July 2010

The most reliable method to determine the concentration of hydroxyl ions in the aqueous phase of hardened cementitious materials is the squeezing of concrete at high pressures. However, this method needs special equipment as well as a relatively high amount of sample to be carried out. In present research, the determination of the OH concentration in the concrete pore solution is undertaken by a leaching method in granulated samples. The experimental program has been made using mortars with 5 different binders and three different leaching solutions. In the treatment of the results, different phenomena (dilution + dissolution of solid phases) occurring during leaching have been taken into account until reaching the target values validated by comparison with those obtained by means of the high pressure technique. The agreement found is good enough, for every binder tested, in spite of the fact that fully understanding of the leaching mechanism is not achieved and that concentrations and not activities of the ions are taken into account in the calculations. Therefore, the method suggested is empirical at present stage.
Determination of iron sulphides in roofing slates from the north west of Spain
Authors: García-Guinea J. , Cardenes V. , Lombardero M. , Desiloniz M. I.
Published: July 2010

The most important production of roofing slates in the world is quarried from the Ordovician formations of the Truchas Syncline, which have the largest amount of working quarries. Roofing slates, sometimes, have crystallized iron sulphides such as pyrite, pyrrhotite and other minerals. These iron sulphides oxidise and stain the tiles when are exposed to atmospheric conditions, so much oxidized how much more inclined is the roof. Galician quarrymen distinguish between harmless pyrite (i.e., resistant cubes of pyrite) and damaging pyrite (i.e., other alterable metallic minerals such as pyrrhotite, chalcopyrite, marcasite and arsenopyirite). An improved identification method is proposed using both methods (a) chemical element ratios of samples under electron microprobes and (b) quantitative determination of the iron sulphides in the slate measuring the oxidized areas by digital camera. The analysed Fe/S ratios, in an XY plot, of seventy metallic samples, define three separated zones: pyrite, pyrrhotite and iron oxi-hydroxides. Quantitative determination of iron sulphides in the slate tile were performed by sinking the tile horizontally for six hours in oxygen peroxide (3% diluted) and capturing the oxidation areas with a magnetic camera and analysing the bitmap images with Sigma-Scan 5 software. The proposed method is faster than the Spanish UNE norm (UNE-EN- 12326-2 Sept.2000), which requires thermal strike cycles for a month. The necessary use of heavy analytical equipment such as electron microprobes can be facilitated by installing it in the Slate Technological Centre of Sobradelo de Valdeorras (Orense) or by using a simple optical stereoscopic zoom microscope to classify the iron minerals.
Physical, mechanical and microscopic characterization of cold bonded fly ash lightweight aggregates
Authors: Videla C. , Martínez P.
Published: July 2010

This study presents the results of the different tests carried out on fly ash lightweight aggregates produced with three different kinds of binders: Lime, Portland cement and Pozzolan Portland cement. The elaboration process used for the aggregates consisted in an agglomeration system by agitation under cold bonded hardening conditions. The tests carried out were a physical characterization of the aggregates, the determination of mechanical properties with a crushing test and, finally, the study of the microstructure of the aggregates with scanning electron microscopy (SEM) and dispersive energy X ray (EDX). From the point of view of mechanical strength, the results indicate that the best kind of aggregate is the one made with a 5% Pozzolan Portland cement. This result was confirmed by the microstructure analysis, which shows that this kind of aggregate presents the highest hydration speed.
Alkali-silica reaction of aggregates for concrete pavements in Chihuahua’s State, Mexico
Authors: Olague C. , Castro P. , López W.
Published: July 2010

The concrete of pavements must resist the climatic conditions, heavy traffic, chemical agents or any other type of aggressive agent. A methodology for characterizing materials that would influence concrete durability was developed considering chemical and physical factors. This methodology allows the consideration of several factors like physiography, geology, and climate, among others that would be of great importance to prevent future durability problems of pavements. This methodology takes into account several tests and this paper presents the results of potential reactivity aggregates of the State of Chihuahua.
The tests for evaluating the reactive siliceous aggregate and the potential alkali-silica reactivity were performed according to the: petrographic examination (ASTM C 295) and standard quick chemical test (ASTM C 289). 38% of the tested sites resulted innocuous, 48% potentially reactive and 13% reactive. It is discussed the benefit of applying a conscious methodology in order to obtain the best results with a representative quantity of tests.
Oxidative capacity of the Mexico City atmosphere – Part 1: A radical source perspective
Authors: Volkamer R. , Sheehy P. , Molina L. T. , Molina M. J.
Published: July 2010

Abstract. A detailed analysis of OH, HO2 and RO2 radical sources is presented for the near field photochemical regime inside the Mexico City Metropolitan Area (MCMA). During spring of 2003 (MCMA-2003 field campaign) an extensive set of measurements was collected to quantify time-resolved ROx (sum of OH, HO2, RO2) radical production rates from day- and nighttime radical sources. The Master Chemical Mechanism (MCMv3.1) was constrained by measurements of (1) concentration time-profiles of photosensitive radical precursors, i.e., nitrous acid (HONO), formaldehyde (HCHO), ozone (O3), glyoxal (CHOCHO), and other oxygenated volatile organic compounds (OVOCs); (2) respective photolysis-frequencies (J-values); (3) concentration time-profiles of alkanes, alkenes, and aromatic VOCs (103 compound are treated) and oxidants, i.e., OH- and NO3 radicals, O3; and (4) NO, NO2, meteorological and other parameters. The ROx production rate was calculated directly from these observations; the MCM was used to estimate further ROx production from unconstrained sources, and express overall ROx production as OH-equivalents (i.e., taking into account the propagation efficiencies of RO2 and HO2 radicals into OH radicals). Daytime radical production is found to be about 10–25 times higher than at night; it does not track the abundance of sunlight. 12-h average daytime contributions of individual sources are: Oxygenated VOC other than HCHO about 33%; HCHO and O3 photolysis each about 20%; O3/alkene reactions and HONO photolysis each about 12%, other sources <3%. Nitryl chloride photolysis could potentially contribute ~15% additional radicals, while NO2* + water makes – if any – a very small contribution (~2%). The peak radical production of ~7.5 107 molec cm−3 s−1 is found already at 10:00 a.m., i.e., more than 2.5 h before solar noon. O3/alkene reactions are indirectly responsible for ~33% of these radicals. Our measurements and analysis comprise a database that enables testing of the representation of radical sources and radical chain reactions in photochemical models. Since the photochemical processing of pollutants in the MCMA is radical limited, our analysis identifies the drivers for ozone and SOA formation. We conclude that reductions in VOC emissions provide an efficient opportunity to reduce peak concentrations of these secondary pollutants, because (1) about 70% of radical production is linked to VOC precursors; (2) lowering the VOC/NOx ratio has the further benefit of reducing the radical re-cycling efficiency from radical chain reactions (chemical amplification of radical sources); (3) a positive feedback is identified: lowering the rate of radical production from organic precursors also reduces that from inorganic precursors, like ozone, as pollution export from the MCMA caps the amount of ozone that accumulates at a lower rate inside the MCMA. Continued VOC reductions will in the future result in decreasing peak concentrations of ozone and SOA in the MCMA.
Twentieth century δ13C variability in surface water dissolved inorganic carbon recorded by coralline algae in the northern North Pacific Ocean and the Bering Sea
Authors: Williams B. , Halfar J. , Steneck R. S. , Wortmann U. G. , Hetzinger S. , Adey W. , Lebednik P. , Joachimski M.
Published: July 2010

Abstract. Oxygen isotopes and Mg/Ca ratios in long-lived coralline algae record ambient seawater temperature in their calcified tissues over time. Similarly, carbon stable isotopes (δ13C) in the calcified tissue may record δ13C values of ambient seawater dissolved inorganic carbon. Here, we measured δ13C in the coralline algae Clathromorphum nereostratum to test the feasibility of reconstructing the intrusion of anthropogenic CO2 into the northern North Pacific Ocean and Bering Sea. δ13C was measured in the high Mg-calcite calcified tissue of three C. nereostratum specimens from two islands 500 km apart in the Aleutian archipelago. In the records spanning 1887 to 2003, the average rate of decline in δ13C values increased from 0.03‰ yr−1 in the 1960s to 0.1‰ yr−1 in the 1990s, which was higher than expected due to solely the δ13C-Suess effect. Deeper water in this region exhibits higher concentrations of CO2 and low δ13C values. Transport of deeper water into surface water (i.e., upwelling) is increased when the Aleutian Low is intensified. We hypothesize that the acceleration of δ13C decline may result from an increase in upwelling from the 1960s to 1990s, which in turn was driven by an increase in the intensity of the Aleutian Low. Detrended δ13C records also vary on 4–7 years and bidecadal timescales supporting an atmospheric teleconnection of tropical climate patterns to the northern North Pacific Ocean and Bering Sea manifested as changes in upwelling.
Climate change assessment for Mediterranean agricultural areas by statistical downscaling
Authors: Palatella L. , Miglietta M. M. , Paradisi P. , Lionello P.
Published: July 2010

Abstract. In this paper we produce projections of seasonal precipitation for four Mediterranean areas: Apulia region (Italy), Ebro river basin (Spain), Po valley (Italy) and Antalya province (Turkey). We performed the statistical downscaling using Canonical Correlation Analysis (CCA) in two versions: in one case Principal Component Analysis (PCA) filter is applied only to predictor and in the other to both predictor and predictand. After performing a validation test, CCA after PCA filter on both predictor and predictand has been chosen. Sea level pressure (SLP) is used as predictor. Downscaling has been carried out for the scenarios A2 and B2 on the basis of three GCM's: the CCCma-GCM2, the Csiro-MK2 and HadCM3. Three consecutive 30-year periods have been considered. For Summer precipitation in Apulia region we also use the 500 hPa temperature (T500) as predictor, obtaining comparable results. Results show different climate change signals in the four areas and confirm the need of an analysis that is capable of resolving internal differences within the Mediterranean region. The most robust signal is the reduction of Summer precipitation in the Ebro river basin. Other significative results are the increase of precipitation over Apulia in Summer, the reduction over the Po-valley in Spring and Autumn and the increase over the Antalya province in Summer and Autumn.
Static output‐feedback for Takagi–Sugeno systems with delays
Authors: Nachidi M. , Tadeo F. , Benzaouia A. , Ait Rami M.
Published: July 2010

A practical methodology to design controllers for Takagi–Sugeno discrete‐time systems with unknown delays is proposed, based on using Linear Matrix Inequalities. More precisely, the design of discrete‐time output‐feedback stabilizing controllers in the presence of bounded delays is solved, when values of the disturbance attenuation and decay‐rate are imposed. A numerical example is provided to illustrate the proposed approach. Copyright © 2010 John Wiley & Sons, Ltd.
Stress Concentration Factors and Weight Functions in Thin Notched Structures of Equibiaxial Anisotropic Materials
Authors: Heinzelmann Michael , Kalamkarov Alexander L.
Published: July 2010

In notched structures, the influence of the notch on the structural strength of the component can be described by a stress concentration factor or—in the presence of cracks–a weight function. Numerous stress concentration factor and weight function solutions are available to the engineer, but regrettably almost exclusively for isotropic materials. In the present study, stress concentration factors and weight functions are calculated for equibiaxial anisotropic materials. The geometry under investigation is a flat plate in tension containing a central hole. The calculated results show that the elastic anisotropic material behavior can significantly influence the magnitude of both stress concentration factors and weight functions.