bluuebunny/crossref_metadata_2025 huggingface dataset:
Best surgical practices: a stepwise approach to the University of Pennsylvania deep brain stimulation protocol
Authors: Kramer Daniel R. , Halpern Casey H. , Buonacore Dana L. , McGill Kathryn R. , Hurtig Howard I. , Jaggi Jurg L. , Baltuch Gordon H.
Published: July 2010

Deep brain stimulation (DBS) is the treatment of choice for otherwise healthy patients with advanced Parkinson disease who are suffering from disabling dyskinesias and motor fluctuations related to dopaminergic therapy. As DBS is an elective procedure, it is essential to minimize the risk of morbidity. Further, precision in targeting deep brain structures is critical to optimize efficacy in controlling motor features. The authors have already established an operational checklist in an effort to minimize errors made during DBS surgery. Here, they set out to standardize a strict, step-by-step approach to the DBS surgery used at their institution, including preoperative evaluation, the day of surgery, and the postoperative course. They provide careful instruction on Leksell frame assembly and placement as well as the determination of indirect coordinates derived from MR images used to target deep brain structures. Detailed descriptions of the operative procedure are provided, outlining placement of the stereotactic arc as well as determination of the appropriate bur hole location, lead placement using electrophysiology, and placement of the internal pulse generator. The authors also include their approach to preventing postoperative morbidity. They believe that a strategic, step-by-step approach to DBS surgery combined with a standardized checklist will help to minimize operating room mistakes that can compromise targeting and increase the risk of complication.
Deep brain stimulation for obsessive-compulsive disorder: past, present, and future
Authors: Mian Matthew K. , Campos Michael , Sheth Sameer A. , Eskandar Emad N.
Published: July 2010

Obsessive-compulsive disorder (OCD) is a psychiatric illness that can lead to chronic functional impairment. Some patients with severe, chronic OCD have been treated with ablative neurosurgical techniques over the past 4 decades. More recently, deep brain stimulation (DBS) has been investigated as a therapy for refractory OCD, and the procedure was granted a limited humanitarian device exemption by the FDA in 2009. In this article, the authors review the development of DBS for OCD, describe the current understanding of the pathophysiological mechanisms of the disorder and how the underlying neural circuits might be modulated by DBS, and discuss the clinical studies that provide evidence for the use of this evolving therapy. The authors conclude with suggestions for how a combined basic science and translational research approach could drive the understanding of the neural mechanisms underlying OCD as well as the clinical effectiveness of DBS in the setting of recalcitrant disease.
Long-term follow-up of deep brain stimulation for Meige syndrome
Authors: Lyons Mark K. , Birch Barry D. , Hillman Renee A. , Boucher Orland K. , Evidente Virgilio Gerald H.
Published: July 2010

Object

Meige syndrome is characterized by blepharospasm, cervical dystonia, and facial oromandibular dystonia. The medical treatment of this condition is largely unsuccessful over time and is a major source of decreased quality of life in those patients suffering from this disease. Recent advances in the application of deep brain stimulation (DBS) surgery techniques for many disorders have prompted several recent reports of DBS for medically refractory cases of Meige syndrome. While the etiology for this disorder is unknown, it is considered by many investigators to be a form of idiopathic torsion dystonia. Pallidal stimulation is widely considered to be effective for dystonia.

Methods

The authors report the long-term results of bilateral globus pallidus internus (GPi) or subthalamic nucleus (STN) stimulation in 3 patients with Meige syndrome and 1 patient with Parkinson disease and associated craniofacial dystonia treated at their center.

Results

Initial 12-month and long-term follow-up Burke-Fahn-Marsden scores were substantially improved in all 4 patients compared with preoperative scores.

Conclusions

Bilateral GPi DBS may be an effective and safe treatment for medically refractory Meige syndrome. The results are comparable with those reported in the literature. Sustained and long-term improvement in symptoms does appear to be reproducible across reports. The authors' patient with Parkinson disease and associated craniofacial dystonia syndrome undergoing bilateral STN DBS noted immediate and sustained improvement in his symptoms. Further study is required, but these results, along with the other reports, suggest that bilateral GPi DBS is an effective treatment for medically refractory Meige syndrome.
Deep brain stimulation in the management of disorders of consciousness: a review of physiology, previous reports, and ethical considerations
Authors: Sen Anish N. , Campbell Peter G. , Yadla Sanjay , Jallo Jack , Sharan Ashwini D.
Published: July 2010

Patients suffering from disorders of consciousness constitute a population that exists largely outside of the daily practice patterns of neurosurgeons. Historically, treatment has focused on nursing and custodial issues with limited neurosurgical intervention. Recently, however, deep brain stimulation has been explored to restore cognitive and physical function to patients in minimally conscious states. In this article, the authors characterize the physiological mechanisms for the use of deep brain stimulation in persistently vegetative and minimally conscious patients, review published cases and associated ethical concerns, and discuss future directions of this technology.
Gene therapy for late infantile neuronal ceroid lipofuscinosis: neurosurgical considerations
Authors: Souweidane Mark M. , Fraser Justin F. , Arkin Lisa M. , Sondhi Dolan , Hackett Neil R. , Kaminsky Stephen M. , Heier Linda , Kosofsky Barry E. , Worgall Stefan , Crystal Ronald G. , Kaplitt Michael G.
Published: July 2010

Object

The authors conducted a phase I study of late infantile neuronal ceroid lipofuscinosis using an adenoassociated virus serotype 2 (AAV2) vector containing the deficient CLN2 gene (AAV2CUhCLN2). The operative technique, radiographic changes, and surgical complications are presented.

Methods

Ten patients with late infantile neuronal ceroid lipofuscinosis disease each underwent infusion of AAV2CUhCLN2 (3 × 1012 particle units) into 12 distinct cerebral locations (2 depths/bur hole, 75 minutes/infusion, and 2 μl/minute). Innovative surgical techniques were developed to overcome several obstacles for which little or no established techniques were available. Successful infusion relied on preoperative stereotactic planning to optimize a parenchymal target and diffuse administration. Six entry sites, each having 2 depths of injections, were used to reduce operative time and enhance distribution. A low-profile rigid fixation system with 6 integrated holding arms was utilized to perform simultaneous infusions within a practical time frame. Dural sealant with generous irrigation was used to avoid CSF egress with possible subdural hemorrhage or altered stereotactic registration.

Results

Radiographically demonstrated changes were seen in 39 (65%) of 60 injection sites, confirming localization and infusion. There were no radiographically or clinically defined complications.

Conclusions

The neurosurgical considerations and results of this study are presented to offer guidance and a basis for the design of future gene therapy or other clinical trials in children that utilize direct therapeutic delivery.
Deep brain stimulation of the orbitofrontal projections for the treatment of intermittent explosive disorder
Authors: Maley Jason H. , Alvernia Jorge E. , Valle Edison P. , Richardson Donald
Published: July 2010

Intermittent explosive disorder (IED) is characterized by a dysfunction in the greater limbic system leading an individual to experience sudden aggressive behavior with little or no environmental perturbation. This report describes a procedure for the treatment of IED in a 19-year-old woman with a history of IED, having had episodes of severe violent attacks against family, dating to early childhood. Due to the severity and intractability of the illness, deep brain stimulation was performed, targeting the orbitofrontal projections to the hypothalamus. The patient's history and the procedure, management, and rationale are described in detail.
Development of intraoperative electrochemical detection: wireless instantaneous neurochemical concentration sensor for deep brain stimulation feedback
Authors: Van Gompel Jamie J. , Chang Su-Youne , Goerss Stephan J. , Kim In Yong , Kimble Christopher , Bennet Kevin E. , Lee Kendall H.
Published: July 2010

Deep brain stimulation (DBS) is effective when there appears to be a distortion in the complex neurochemical circuitry of the brain. Currently, the mechanism of DBS is incompletely understood; however, it has been hypothesized that DBS evokes release of neurochemicals. Well-established chemical detection systems such as microdialysis and mass spectrometry are impractical if one is assessing changes that are happening on a second-to-second time scale or for chronically used implanted recordings, as would be required for DBS feedback. Electrochemical detection techniques such as fast-scan cyclic voltammetry (FSCV) and amperometry have until recently remained in the realm of basic science; however, it is enticing to apply these powerful recording technologies to clinical and translational applications. The Wireless Instantaneous Neurochemical Concentration Sensor (WINCS) currently is a research device designed for human use capable of in vivo FSCV and amperometry, sampling at subsecond time resolution. In this paper, the authors review recent advances in this electrochemical application to DBS technologies. The WINCS can detect dopamine, adenosine, and serotonin by FSCV. For example, FSCV is capable of detecting dopamine in the caudate evoked by stimulation of the subthalamic nucleus/substantia nigra in pig and rat models of DBS. It is further capable of detecting dopamine by amperometry and, when used with enzyme linked sensors, both glutamate and adenosine. In conclusion, WINCS is a highly versatile instrument that allows near real-time (millisecond) detection of neurochemicals important to DBS research. In the future, the neurochemical changes detected using WINCS may be important as surrogate markers for proper DBS placement as well as the sensor component for a “smart” DBS system with electrochemical feedback that allows automatic modulation of stimulation parameters. Current work is under way to establish WINCS use in humans.
Current and future indications for deep brain stimulation in pediatric populations
Authors: Lipsman Nir , Ellis Michael , Lozano Andres M.
Published: July 2010

Deep brain stimulation (DBS) has proven to be an effective and safe treatment option in patients with various advanced and treatment-refractory conditions. Thus far, most of the experience with DBS has been in the movement disorder literature, and more specifically in the adult population, where its use in conditions such as Parkinson disease has revolutionized management strategies. The pediatric population, however, can also be afflicted by functionally incapacitating neurological conditions that remain refractory despite the clinicians' best efforts. In such cases, DBS offers an additional treatment alternative. In this paper, the authors review their institution's experience with DBS in the pediatric population, and provide an overview of the literature on DBS in children. The authors conclude that DBS in children can and should be considered a valid and effective treatment option, albeit in highly specific and carefully selected cases.
Surgical treatment of single-suture craniosynostosis: an argument for quantitative methods to evaluate cosmetic outcomes
Authors: Hankinson Todd C. , Fontana Elizabeth J. , Anderson Richard C. E. , Feldstein Neil A.
Published: July 2010

The traditional reasons for surgical intervention in children with single-suture craniosynostosis (SSC) are cosmetic improvement and the avoidance/treatment of intracranial hypertension, which has been thought to contribute to neurocognitive deficits. Despite considerable work on the topic, the exact prevalence of intracranial hypertension in the population of patients with SSC is unknown, although it appears to be present in only a minority. Additionally, recent neuropsychological and anatomical literature suggests that the subtle neurocognitive deficits identified in children with a history of SSC may not result from external compression. They may instead reflect an underlying developmental condition that includes disordered primary CNS development and early suture fusion. This implies that current surgical techniques are unlikely to prevent neurocognitive deficits in patients with SSC. As such, the most common indication for surgical treatment in SSC is cosmetic, and most patients benefit from considerable subjective cosmetic normalization following surgery. Pediatric craniofacial surgeons have not, however, agreed upon objective means to assess postoperative cranial morphological improvement. We should therefore endeavor to agree upon objective craniometric tools for the assessment of operative outcomes, allowing us to accurately compare the various surgical techniques that are currently available.
Prevalence of tethered spinal cord in infants with VACTERL
Authors: O'Neill Brent R. , Yu Alexander K. , Tyler-Kabara Elizabeth C.
Published: July 2010

Object

The term VACTERL represents a nonrandom association of birth defects including vertebral malformations, anal atresia, cardiac anomalies, tracheoesophageal fistulas (TEFs), renal anomalies, and limb malformations. Clinical experience and a few published case series suggest that a tethered spinal cord (TSC) occurs commonly in children with VACTERL, but to date, no study has defined the prevalence of TSC in patients with VACTERL. Such information would guide decisions about the appropriateness of screening spinal imaging.

Methods

The authors reviewed the charts of all patients discharged from the neonatal intensive care unit at Children's Hospital Pittsburgh in the past 14 years with the diagnosis of VACTERL, TEF, or anal atresia. During that period, the authors' protocol has been to use spinal ultrasound to screen this population for TSC. The charts were reviewed for the presence of a TSC requiring surgery and for the features of VACTERL.

Results

Thirty-three patients with VACTERL and adequate spinal imaging studies were identified. In 13 (39%) of these, a TSC requiring surgery was identified. Among patients without VACTERL, the incidence of TSC was 7.9% in those with anal atresia and 2.4% in those with TEF. False-negative ultrasounds were identified in 21.4% of patients with TSC.

Conclusions

Children with VACTERL should undergo MR imaging screening for TSC. In infants with anal atresia without VACTERL, the incidence of TSC is much lower than in those with VACTERL.
Stimulation of the globus pallidus internus in a patient with DYT1-positive primary generalized dystonia: a 10-year follow-up
Authors: Alcindor Dunbar , Oh Michael Y. , Baser Susan , Angle Cindy , Cheng Boyle C. , Whiting Donald
Published: July 2010

The authors report the case of DYT1-positive primary generalized dystonia refractory to medical management that was successfully treated with continuous deep brain stimulation of the internal segment of the globus pallidus. Prior studies have shown that neuromusculoskeletal deficits can remain permanent if early surgical intervention is not undertaken. The authors report prolonged efficacy and safety over a 10-year period in a 28-year-old man.
Transfer of the phrenic nerve to the posterior division of the lower trunk to recover thumb and finger extension in brachial plexus palsy
Authors: Lin Haodong , Hou Chunlin , Chen Aimin , Xu Zhen
Published: July 2010

Object

Hand function is severely impaired in cases of lower root avulsion. In the present study, the authors investigated the clinical effectiveness and safety of phrenic nerve transfer to the posterior division of the lower trunk of the brachial plexus to recover thumb and finger extension.

Methods

Between 2004 and 2006, 10 patients with brachial plexus palsy underwent phrenic nerve transfer as part of a strategy for surgical reconstruction of their plexuses. The mean patient age of was 27.2 years (range 18–44 years), and the mean interval from injury to surgery was 5.7 months (range 3–9 months). The phrenic nerve was always transferred to the posterior division of the lower trunk.

Results

The follow-up of the patients ranged from 2.5 to 4.4 years, with an average follow-up length of 3.5 years. There were no major complications related to the surgery. Eight patients recovered to Grade 3 or better (Medical Research Council grade) in extensor digitorum strength, and 7 patients recovered to Grade 3 or better in extensor pollicis strength. None of the patients had any clinical signs or symptoms of respiratory insufficiency.

Conclusions

Satisfactory thumb and finger extension can be achieved by phrenic nerve transfer to the posterior division of the lower trunk of the brachial plexus. This procedure is simple and less traumatic than that of transferring the phrenic nerve to the radial nerve. It is indicated in cases in which the brachial plexus is relatively intact at the division level.
Large-Scale Synthesis of Carbon Nanomaterials by Catalytic Chemical Vapor Deposition: A Review of the Effects of Synthesis Parameters and Magnetic Properties
Authors: Qi Xiaosi , Qin Chuan , Zhong Wei , Au Chaktong , Ye Xiaojuan , Du Youwei
Published: July 2010

The large-scale production of carbon nanomaterials by catalytic chemical vapor deposition is reviewed in context with their microwave absorbing ability. Factors that influence the growth as well as the magnetic properties of the carbon nanomaterials are discussed.
New Graduate Nurses’ Perceptions of the Effects of Clinical Simulation on Their Critical Thinking, Learning, and Confidence
Authors: Kaddoura Mahmoud A.
Published: July 2010

Critical thinking has been a crucial outcome of nursing educational programs. Effective nurses should be knowledgeable about complex patient situations and confident in their skills. One teaching strategy recently adopted by some educators to develop nurses’ critical thinking, learning, and confidence is simulation. Simulation incorporates scenarios and case studies developed to replicate real-life clinical situations. Learners are asked to solve clinical problems and make critical decisions based on the information provided. Little research has been done on how simulation experiences promote critical thinking, learning, and confidence, especially in new graduate nurses. This study explored the perceptions of new graduate nurses of how clinical simulation developed their critical thinking skills, learning, and confidence throughout their hospital clinical training. Ten new baccalaureate nursing graduates voluntarily participated in this study, which used an exploratory descriptive design. Data were collected by demographic questionnaires and semi-structured interviews and were analyzed using content analysis. Participants reported that simulation prepared them well to care confidently for critically ill patients. Simulation also helped them learn to make sound clinical decisions to improve patient outcomes. The findings have crucial implications for nursing education, practice, and research. They provide evidence to support the use of simulation as a teaching strategy to promote critical thinking skills, learning, and confidence.
Primary Congenital Glaucoma Associated With Patau Syndrome With Long Survival
Authors: Jaru-Ampornpan Pimkwan , Kuchtey John , Dev V.G. , Kuchtey Rachel
Published: July 2010

Ocular abnormalities are common in Patau syndrome (trisomy 13), but only a few cases with congenital glaucoma have been reported, some of which were associated with other ocular defects. This report describes a case of primary congenital glaucoma in an 11-year-old patient with full trisomy 13.
The Role of Occupational Therapy in Diabetes Self-Management Interventions
Authors: Pyatak Elizabeth A.
Published: July 2010

Approximately 23.6 million people in the United States are living with diabetes, a disease that is a leading cause of disabling conditions including blindness, kidney failure, amputations, heart disease, and stroke. Although these complications of diabetes can be delayed or prevented through intensive diabetes self-management (DSM), maintaining control of the disease can be burdensome and negatively impact quality of life. Occupational therapy has a largely untapped potential to assist individuals who struggle with managing diabetes in the context of everyday life, yet there is little discussion of DSM in the occupational therapy literature. The author conducts a systematic review of the existing occupational therapy literature on diabetes, examines the current state of DSM interventions, and discusses a potential role for occupational therapy using programs such as Lifestyle Redesign®.
In Vivo Laser Confocal Microscopic Analysis of Corneal K-Structures After Keratorefractive Surgery (LASIK and Epi-LASIK)
Authors: Yokogawa Hideaki , Kobayashi Akira , Tagawa Kosaku , Sugiyama Kazuhisa
Published: July 2010

Background and Objective:

To demonstrate alterations of corneal K-structures (sub-Bowman’s fibrous structures) after keratorefractive surgery by in vivo laser confocal microscopy and to look for association of K-structures with fluorescein-stained anterior corneal mosaic (ACM).

Patients and Methods:

Five patients (nine eyes) participated in this study. For four patients, one eye was evaluated after laser in situ keratomileusis (LASIK) and the other after epipolis-laser in situ keratomileusis (epi-LASIK). For one patient, the left eye was evaluated after epithelial debridement. A photograph of the ACM was obtained. Central corneal regions were scanned by Heidelberg Retina Tomograph 2 Rostock Cornea Module (Heidelberg Engineering GmbH, Heidelberg, Germany).

Results:

The ACM and K-structures disappeared in all corneas after epi-LASIK, but not after LASIK and epithelial debridement cornea.

Conclusion:

The presence of K-structures and ACM may be an index to identify eyes that had a previous refractive surgical procedure (surface ablation or LASIK) and be a health index of Bowman layer and adjacent anterior stroma.
Apoptosis in Diabetic Fibrovascular Membranes After Panretinal Photocoagulation
Authors: Tran Anh T. , Bula Deisy V. , Kovacs Kyle D. , Savageau Judy , Arroyo Jorge G.
Published: July 2010

A more complete understanding of the role of apoptosis in the regression of diabetic neovasculature following laser panretinal photocoagulation (PRP) will both elucidate the treatment’s therapeutic mechanism and potentially lead to novel treatments for neovascularization associated with proliferative diabetic retinopathy that target apoptotic pathways. Pars plana vitrectomy with fibrovascular membrane delamination was performed on five patients with proliferative diabetic retinopathy, with four having received previous PRP treatment and one no previous laser treatment. Using in situ terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling, propidium iodide and hematoxylin–eosin staining, apoptotic cells were identified in the excised membranes. The authors found evidence of cells undergoing apoptosis in all of the excised membranes, with increasing amounts of preoperative PRP associated with an increased number of apoptotic cells per millimeter of membrane. The preliminary data suggest that the decrease in ambient mitogen, initiated by PRP treatment, activates apoptosis in diabetic fibrovascular membranes.
Morteros a base de suelos. Caracterización
Authors: Cabrera J. L. , Fernández Collazo Y. , González Ramírez N. , Bermúdez Valles S.
Published: July 2010

The goals states in this work are included in a study with different volumetric dosifications, using different kinds of soils like aggregates, and cement and lime like binding material to be used in mansonry mortars.
The mortars were caracterized by determining the R a/c, Rf and Re to different ages, R adh. to 28 days, capilar absorption till constant values and cost/m3 of mortars.
The results show that mansonry mortars made with soils fulfill the necessary parameters to be used in construction works with cement-soils.
The leaning Tower of Pisa, Structure, building materials and reinforcement interventions
Authors: Veniale F.
Published: July 2010

An exhaustive diagnosis of "anatomy, physiology and pathology" of the masonry body of the leaning Tower of Pisa has been carried out with the aim of integrate the knowledge of the structure features, mechanical conditions and decay processes of the building materials, necessary for correctly managing the therapy, temporary and definitive interventions.
The interventions already or being implemented consist of (i) outer circular slightly stressed steel tendons, (ii) inner stressed and/or passive strainless bars, and (iii) grouting by a specially devised cement admixture.
The paper will not be dealing with "materic" restoration works, and geotechnical interventions for reducing the progressive tilting and stabilizing the foundation/subsoil system of the Tower.
Evaluation of the penetration of restoration materials in stone. A new method
Authors: Rodríguez-Gordillo J. , Durán-Suárez J. A. , García-Casco A.
Published: July 2010

We have used the measurements of the water-stone contact angle on the surface of sections of biocalcarenite samples to evaluate the penetration of organic and silico-organic restoration products in this rock. The method has been found to be effective and precise, allowing us to distinguish the depth of the zone with water-repellent characteristics from that with merely a consolidating effect.
Reinforced plaster by means of the synergic action between concrete additives (superfluidifiers, fluidifiers and airing-plasticizers) and E glass fibres
Authors: Del Río Merino M. , Hernández Olivares F.
Published: July 2010

Through the analysis of the different compounds (plaster + additives + E glass fibres) we pretend to demostrate that a synergic action is present between certain concrete additives (superfluidifiers, fluidiflers, and airingplasticizers) and E glass fibre, on the basis of the flection resistance of plaster matrix based compound materials.
Recycling of the Granite Quarries and Municipal Incinerator Wastes for the Processing of New Materials as Porcelainized Stoneware
Authors: Hernández-Crespo M. S. , Rincón J. M.
Published: July 2010

In the 1980s started in the ceramic sector the material conception of porcelainized stoneware, a product with versatile and modern characteristics similar to those of the natural stone, depicting improved properties to the marble and granite. Porcelanized stoneware is a compact ceramic material, very hard and homogeneous, generally not fully vitreous (unglazed) in its surface, obtained by fast firing from compositions enriched in kaolinite, which contain a large quantity of fluxes. The raw materials for body are a mixture that contains an adequate relationship of kaolinitic clays, feldspars and quartz. Such material is characterized by its low or almost zero porosity, being adequated to sustain heavy and high traffic intensity for uses in and outside of buildings with wide range of aspects, desings and colors.
By considering the chemistry and mineralogical composition of the granite and incinerator wastes, this paper describes their use in the processing of construction materials, specifically, in a new type of stoneware flooring and covering materials.
According to the most of the physical and mechanical properties here determined, these "Modified Porcelainized Stoneware" (MPS) materials are close to the conventional porcelainized stoneware and glass ceramics products.
Pozzolanic properties of residues of sugar industries (first part)
Authors: Martirena-Hernández J. F. , Betancourt-Rodríguez S. , Middendorf B. , Rubio A. , Martínez-Fernández J. , Machado López J. , González-López R.
Published: July 2010

Non altered straw and sugar cane bagasse ash (CPC, CBC) collected directly from the boilers in the sugar industry and from non-controlled burning in the open fields turned up to be a reasonably good pozzolana, which can be utilized for the manufacture of lime-pozzolana binders. This paper presents a detailed survey of this material with the aim to use it as raw material in the manufacture of binders.
Quality study of a fedspar deposit
Authors: Taboada J. , Vaamonde A. , Saavedra A. , Argüelles A.
Published: July 2010

This work describes a pegmatite mineral deposit composed by some veins of a length between 50 and 800 meters and a width of almost 15 meters. With the purpose to evaluate the potential exploitation, we have characterized the quality of the selling product, through a sampling procedure, granulometric classification, magnetic separation, flotation process and mineralogical analysis. In order to establish the more able flotation process, we have tested different methods, that we also include here. Later on, and with the finality to establish the selling feldspar percentage in the deposit, we realized a geostatic study in order to identify, not only the different qualities but also its distribution in the deposit.
Influence of temperature and composition in the mechanical resistance and porosity of ceramic pieces
Authors: Jordán Vidal M. M. , Sanfeliu Montolio T. , De la Fuente Cullell C.
Published: July 2010

We have tried to establish a relationship between the raw material and the mechanical properties of ceramic pieces subjected to different firing processes, so under the determinant of the thermal process we have done a follow up on the petrogenetic process that the manufacture of ceramics represents. This is evaluated in terms of the mechanical behaviour of the ceramic tile bodies, which have been normalised and submitted to tests for flexion. The principal objective is to be able to indicate what the optimum firing temperature for each sample is, and to determine what it is in the ceramic body which offers the greatest resistance when a specific force is applied. The study of the texture of the ceramic body will be considered mainly in relation to the existent porosity, as well as its distribution, which conditions its characteristics and specifications. The relation between porosity and the parameters that describe the porous texture of the ceramic tile pieces studied is complicated because of the fact that these have many pores with a complex and irregular spatial disposition, with a broad distribution of forms and sizes, and as such they do not fit into established empirical equations.
Pozzolanic properties of residues of sugar industries (second part)
Authors: Martirena-Hernández J. F. , Betancourt-Rodríguez S. , Middendorf B. , Rubio A. , Martínez-Fernández L. , Machado López I. , González-López R.
Published: July 2010

Results of studies conducted in lime pozzolana pastes are introduced in this paper. The pozzolana was sourced from Sugar Cane Baggasse Ash (CBC) and Sugar Cane Straw Ash (CPC). The hydration of this binder was carefully monitored by means of instrumental techniques with the aim of describing the kinetics of the reaction.
Condition of knowledge about the Friedel’s salt
Authors: Lannegrand R. , Ramos G. , Talero R.
Published: July 2010

A vast bibliography revision is done about the Friedel's salt. The structure, more possible mechanisms of formation and stability intervals in presence of other salts and temperature effect and by pH are pointed out.
Designing concrete for durability
Authors: Boyd A. J. , Mindess S. , Skalny J.
Published: July 2010

Some of the factors affecting the durability of modern concrete structures are discussed, with an emphasis on the problems caused by modern portland cements. This is followed by a description of some concrete durability issues of current interest, such as plastic shrinkage, seawater attack, and sulfate attack. The strategies for testing for durability are also discussed. It is concluded that, to produce durable concretes, a holistic approach to concrete construction must be adopted.
Trace elements based classification on clinkers. Application to Spanish clinkers
Authors: Tamás F. D. , Abonyi J. , Puertas F.
Published: July 2010

The qualitative identification to determine the origin (i.e. manufacturing factory) of Spanish clinkers is described. The classification of clinkers produced in different factories can be based on their trace element content. Approximately fifteen clinker sorts are analysed, collected from 11 Spanish cement factories to determine their Mg, Sr, Ba, Mn, Ti, Zr, Zn and V content. An expert system formulated by a binary decision tree is designed based on the collected data. The performance of the obtained classifier was measured by ten-fold cross validation. The results show that the proposed method is useful to identify an easy-to-use expert system that is able to determine the origin of the clinker based on its trace element content.
Swelling behaviour of stones and its interest in conservation. An appraisal
Authors: Delgado Rodrigues J.
Published: July 2010

Swelling can be defined as the volume increase experienced by any solid body when wetted. Many lithotypes (carbonate rocks, sandstones, igneous rocks) have expansive components in their composition; anhydrite and clay minerals are the two best-known expansive components in stone materials. Swelling strain can be easily quantified and swelling pressure determination is accessible in many geotechnical laboratories. This paper deals with the decay of stone due to swelling of clays and discusses the ways to take the swelling behaviour into account when the assessment of stone durability is concerned. It analyses the role of swelling in stone conservation and reviews some cases where this decay mechanism has a relevant role, explicit or implicitly.
Wastes based glasses and glass-ceramics
Authors: Barbieri L. , Corradi A. , Lancellotti I.
Published: July 2010

Actually, the inertization, recovery and valorisation of the wastes coming from municipal and industrial processes are the most important goals from the environmental and economical point of view. An alternative technology capable to overcome the problem of the dishomogeneity of the raw material chemical composition is the vitrification process that is able to increase the homogeneity and the constancy of the chemical composition of the system and to modulate the properties in order to address the reutilization of the waste. Moreover, the glasses obtained subjected to different controlled thermal treatments, can be transformed in semy-cristalline material (named glass-ceramics) with improved properties with respect to the parent amorphous materials. In this review the tailoring, preparation and characterization of glasses and glass-ceramics obtained starting from municipal incinerator grate ash, coal and steel fly ashes and glass cullet are described.
Use of dry sludge from waste water treatment plants as an additive in prefabricated concrete brick
Authors: Yagüe A. , Valls S. , Vázquez E. , Kuchinow V.
Published: July 2010

Dry sludge from the Sabadell Water Treatment Plant was used to prepare prefabricated concrete bricks.
After characterising the sludge and the manufacturing process used to make the bricks, we define the conditions of addition of the sludges in the manufacture. Reference samples not containing sludge and samples containing 2 % of dry sludge by cement weight were prepared. The variation in density, porosity, absorption coefficient and compressive strength of the bricks with the presence of sludge was determined over time. Leaching of the bricks was determined according to the NEN 7345 standard.
In most cases the addition of sludge produces a decrease in porosity and absorption coefficients and an increase in compressive strength, so one could expect these bricks to have greater durability. As regards leaching pollutants in the bricks, they are below the limit of the Dutch NEN standard for construction materials and thus can be classified as inert material.
Study of the instability of black slags from electric arc furnace steel industry
Authors: Frías M. , Sánchez de Rojas M. I. , Uría A.
Published: July 2010

In Spain, the steel manufacture produces important quantities of by-products, representing between 15 and 20 % of total steel production. Most by-products are deposited on open air spaces causing serious economical and environmental problems, internationally, different recycling wais are studied, being the main alternative for these by-products as recycled aggregate. The possibility of recycling these by-products in construction sector depends on its possible volume instability because of the presence of some undesirable compounds. In current paper, two different black slags from electric arc furnace steel industry were chemically characterized, paying attention to some well-known compounds by theirs expansion effects, such as: free CaO, free MgO, chlorides and sulphates.
The analytical results carried out in the current research detected the presence of insignificant or null amounts of harmful compounds. Therefore, they should not have any negative incidence on phenomena of volume instability.
Analysis of the effect of volume on the bending strength of the Spanish scot and laricio pine timber
Authors: Fernández-Golfín J. I. , Hermoso E. , Díez M. R.
Published: July 2010

Since the beginning of the XX century it has been recognized that the bending strength of timber is affected by the size of the specimen.
In the present work the influence of depth (h) and thickness (t) on the characteristic bending strength (fk) of both Scot (Pinus sylvestris) and Laricio (Pinus nigra) pine Spanish grown timber is assessed.
1.733 pieces of both species ranging in size from 100x40x2500 mm to 200x70x4.500 mm and especially sampled for this work, have been tested for bending in accordance with UNE EN 408 standard.
In both species, the influence of depth and thickness on the characteristic bending strength of timber is highly significative but different between them and lead to conclude that the effect of the species is also significative and thus that the proposition of general values should be done cautiously, avoiding extrapolations.
It is also concluded that, for both species, the effect of thickness seems to be highly significative and thus shouldn’t be ignored by the European standards.
Finally, the convenience of revising the present depth factor considered in UNE EN 384 and UNE ENV 1995-1-1 standards is also suggested.
ALLOGENEIC HEMATOPOIETIC CELL TRANSPLANTATION IN THE TREATMENT OF CHRONIC LYMPHOCITIC LEUKEMIA : WHY AND WHEN ?
Authors: Delioukina Maria L. , Forman Stephen J.
Published: July 2010

Chronic lymphocytic leukemia (CLL) is the most common hematologic malignancy in adults with an incidence rate of 4.2 per 100,000 per year. CLL frequently takes an indolent course, with some patients not requiring treatment for years, yet is incurable by currently available chemo- and immuno-therapeutic modalities. Despite high initial response rates, particularly to purine analogues, patients invariably relapse and subsequently develop resistance to therapy. The traditional “watchful waiting” approach to CLL is being challenged by data showing that treatments used early in the disease course impact long-term overall and progression-free survivals . The only curative treatment for CLL currently, is allogeneic hematopoeietic cell transplantation (alloHCT). In contrast to autologous transplant, myeloablative alloHCT for CLL patients generates durable remissions with promising survival plateaus; however, significant transplant related mortality (TRM) is also observed (25-50%) . At present the fact remains that for poor-risk CLL, alloHCT is the only treatment with the potential of providing long-term disease control. Future combinations with emerging low-toxicity therapies may further enhance the curative potential of allogeniec hematopoietic cell transplant. New drugs can also potentially enable refractory patients to attain response as a bridge to more effective stem cell transplantation.
An overview of the Amazonian Aerosol Characterization Experiment 2008 (AMAZE-08)
Authors: Martin S. T. , Andreae M. O. , Althausen D. , Artaxo P. , Baars H. , Borrmann S. , Chen Q. , Farmer D. K. , Guenther A. , Gunthe S. S. , Jimenez J. L. , Karl T. , Longo K. , Manzi A. , Pauliquevis T. , Petters M. D. , Prenni A. J. , Pöschl U. , Rizzo L. V. , Schneider J. , Smith J. N. , Swietlicki E. , Tota J. , Wang J. , Wiedensohler A. , Zorn S. R.
Published: July 2010

Abstract. The Amazon Basin provides an excellent environment for studying the sources, transformations, and properties of natural aerosol particles and the resulting links between biological processes and climate. With this framework in mind, the Amazonian Aerosol Characterization Experiment (AMAZE-08), carried out from 7 February to 14 March 2008 during the wet season in the central Amazon Basin, sought to understand the formation, transformations, and cloud-forming properties of fine- and coarse-mode biogenic aerosol particles, especially as related to their effects on cloud activation and regional climate. Special foci included (1) the production mechanisms of secondary organic components at a pristine continental site, including the factors regulating their temporal variability, and (2) predicting and understanding the cloud-forming properties of biogenic particles at such a site. In this overview paper, the field site and the instrumentation employed during the campaign are introduced. Observations and findings are reported, including the large-scale context for the campaign, especially as provided by satellite observations. New findings presented include: (i) a particle number-diameter distribution from 10 nm to 10 μm that is representative of the pristine tropical rain forest and recommended for model use; (ii) the absence of substantial quantities of primary biological particles in the submicron mode as evidenced by mass spectral characterization; (iii) the large-scale production of secondary organic material; (iv) insights into the chemical and physical properties of the particles as revealed by thermodenuder-induced changes in the particle number-diameter distributions and mass spectra; and (v) comparisons of ground-based predictions and satellite-based observations of hydrometeor phase in clouds. A main finding of AMAZE-08 is the dominance of secondary organic material as particle components. The results presented here provide mechanistic insight and quantitative parameters that can serve to increase the accuracy of models of the formation, transformations, and cloud-forming properties of biogenic natural aerosol particles, especially as related to their effects on cloud activation and regional climate.
The influence of small-scale variations in isoprene concentrations on atmospheric chemistry over a tropical rainforest
Authors: Pugh T. A. M. , MacKenzie A. R. , Langford B. , Nemitz E. , Misztal P. K. , Hewitt C. N.
Published: July 2010

Abstract. Biogenic volatile organic compounds (BVOCs) such as isoprene constitute a large proportion of the global atmospheric oxidant sink. Their reactions in the atmosphere contribute to processes such as ozone production and secondary organic aerosol formation. However, over the tropical rainforest, where 50% of the global emissions of BVOCs are believed to occur, atmospheric chemistry models have been unable to simultaneously simulate the measured daytime concentration of isoprene and that of its principal oxidant, hydroxyl (OH). One reason for this model-measurement discrepancy may be incomplete mixing of isoprene within the convective boundary layer, leading to patchiness or segregation in isoprene and OH mixing ratios and average concentrations that appear to be incompatible with each other. One way of capturing this effect in models of atmospheric chemistry is to use a reduced effective rate constant for their reaction. Recent studies comparing atmospheric chemistry global/box models with field measurements have suggested that this effective rate reduction may be as large as 50%; which is at the upper limit of that calculated using large eddy simulation models. To date there has only been one field campaign worldwide that has reported co-located measurements of isoprene and OH at the necessary temporal resolution to calculate the segregation of these compounds. However many campaigns have recorded sufficiently high resolution isoprene measurements to capture the small-scale fluctuations in its concentration. We use a box model of atmospheric chemistry, constrained by the spectrum of isoprene concentrations measured, to estimate segregation intensity of isoprene and OH from high-frequency isoprene time series. The method successfully reproduces the only directly observed segregation. The effective rate constant reduction for the reaction of isoprene and OH over a South-East Asian rainforest is calculated to be typically <15%. This estimate is not sensitive to heterogeneities in NO at this remote site, unless they are correlated with those of isoprene, or to OH-recycling schemes in the isoprene oxidation mechanism, unless the recycling happens in the first reaction step. Segregation alone is therefore unlikely to be the sole cause of model-measurement discrepancies for isoprene and OH above a rainforest.
Aerosol Single Scattering Albedo retrieved from ground-based measurements in the UV-visible
Authors: Buchard V. , Brogniez C. , Auriol F. , Bonnel B.
Published: July 2010

Abstract. Estimates of Aerosol Single Scattering Albedo (SSA) from ground-based spectral measurements in the UV-visible are conducted at Villeneuve d'Ascq (VdA) in France. In order to estimate this parameter, measurements of global and diffuse UV-visible solar irradiances performed under cloud-free conditions since 2003 with a spectroradiometer operated by the Laboratoire d'Optique Atmosphérique (LOA) are used. The technique consists in comparing the measured irradiance values to modelled irradiances computed for various SSA. The retrieval is restricted to the 330–450 nm range to avoid ozone influence. For validation purpose, the retrieved values of SSA at 440 nm are compared to the ones obtained from sunphotometer measurements of the AERONET/PHOTONS network available on the LOA site. The results are rather satisfying: in 2003 and 2005–2006 the Root Mean Square (RMS) of the differences are about 0.05, these values are within the uncertainty domain of retrieval of both products. Distinction between days characterized by different aerosol content, by means of the aerosol optical thickness (AOT) retrieved from ground-based measurements at the same wavelength, shows that the comparisons between both products are better when AOT are higher. Indeed in case AOT are greater than 0.2, the RMS is 0.027 in 2003 and 0.035 in 2005–2006. The SSA estimated at 340 and 380 nm from ground-based spectra are also studied, though no validation can be carried out with sunphotometer data (440 nm is the shortest wavelength at which the SSA is provided by the network). The good comparisons observed at 440 nm can let assume that the SSA retrieved from spectroradiometer measurements at the two other wavelengths are also obtained with a good confidence level. Thus these values in the UV range can be used to complete aerosol data provided by AERONET/PHOTONS at VdA. Moreover they can be used for a best knowledge of the aerosol absorption that is necessary to quantify the error on surface UV irradiances estimated from satellite.