bluuebunny/crossref_metadata_2025 huggingface dataset:
Physical effects of natural pozzolana on alkali-activated slag cement
Authors: Zeghichi L. , Benghazi Z.
Published: June 2011

The alkali-activated slag (AAS) cement is an interesting building material, confronting to the new economical and ecological challenges. In order to enhance its physical properties in comparison with ordinary Portland cement (OPC), we used natural pozzolana as a mineral addition. The parameters studied are: the fineness of the addition (5350 and 5650 cm2/g), and its percentage (0 to 30%). The activator used is NaOH (5M) and the curing temperature was fixed at 20°C. The results show the possibility to obtain compound alkali-activated slag cement with better stability and a compressive strength higher than 35 MPa.
Repair and rehabilitation of corrosiondamaged concrete elements using FRP composite wraps
Authors: Karpate H. , Wheat H. , Jirsa J. , Fowler D. , Whitney D.
Published: June 2011

Reinforced concrete structures have been wrapped to provide strength and confinement in the presence of seismic loads. The wrapping of structures as a means of mitigating corrosion is relatively recent. The objective of the work to be described is to investigate the long-term effectiveness of fiber-reinforced polymer (FRP) composite wraps in mitigating corrosion in reinforced concrete elements in severe environments.
Evaluation of bulk orthotropic properties of heavy plywood bridge decking
Authors: Adam C. , Milner H. , Ahmed B.
Published: June 2011

This paper devises a method for modelling the bulk orthotropic properties of heavy plywood bridge decking described in Australia as Bridgewood, which can be customized in terms of the number of plies it consists of and also the direction of the grain for each ply to distribute its strength and stiffness characteristics laterally and longitudinally. Modelling plywood decking in finite element programs (FE) represents a problem, as an example a 166 mm deep plywood deck will contain approximately 50 × 3 mm thick single veneers that ideally should be represented individually in any complete bridge superstructure model. When taken over a 12 m span on a 3.2m wide bridge deck the FE model grows to an unmanageable size if element aspect ratios are to be held to no greater than 4 as recommended in Strand 7 (the FE software used). The size of the FE model was reduced whereby Bridgewood was treated as an orthotropic material with bulk elastic properties. A smaller model is used first in which the veneers are represented directly and specific loadings and support conditions applied that enable bulk elastic properties to be determined. To a limited extent, the bulk properties are then confirmed by laboratory testing.
Electron tunnelling in metallic beads systems and slow electric relaxation
Authors: Tekaya A. , Bouzerar R. , Bourny V. , Tekaya I.
Published: June 2011

We study numerically and theoretically the electrical behavior of individual steel beads and the contact between 2 adjacent beads within a granular system. Due to the thin insulating oxide layer present at the surface of the beads, the coupling between neighboring beads is likely to occur through electron tunneling. The quantum tunneling dominates at low current where it generates a high resistance in the upwards characteristic. Retaining only fundamental ingredients such as modeling the tunneling contact as a parallel RC circuit, we show how our model agrees qualitatively and quantitatively with experimental results as the observed hysteretic features and the slow relaxation of the electrical properties of a large assembly of beads.
Bioadsorption of suspended and dissolved particles from coal washery effluent onto fluted pumpkin seed shell biomass
Authors: Menkiti M. , Chime T. , Onukwuli O.
Published: June 2011

Fluted pumpkin seed shell, an abundant and inexpensive natural resource in Nigeria, was used as a precursor to adsorbent production for the removal of suspended and dissolved particle (SDP) from initially coagulated coal washery effluent (CWE). Key parameters such as contact time, adsorbent dose, pH and temperature were investigated using batch mode. The adsorption equilibrium, thermodynamics and kinetics of SDP on H3PO4 treated shell (FPA) and NH4Cl treated shell (FPS) were examined at specified temperatures. Equilibrium data sufficiently fit the Langmuir isotherm model (R2 > 0.99; SSE < 0.09). The pseudo-second order kinetic model provides the best correlation (R2>0.99;SSE<0.1) with the experimental data. The evaluated ΔG○ and ΔH○ indicate the spontaneous and endothermic nature of the process. This study demonstrates that pumpkin seed shell could be utilized as low cost, renewable, ecofriendly bioadsorbent for the removal of SDP from CWE.
Effect of seasonal changes on overburden stripping in limestone quarry
Authors: Adebayo B. , Taiwo O.
Published: June 2011

This paper examines the influence of seasonal changes on stripping of overburden in West African Portland Cement (WAPCO) Shagamu, Nigeria. In order to achieve this tonnage of overburden moved per mouth, tonnage of exposed and workable limestone available for blasting were determined during dry and rainy season for 3 years. The results showed that overburden stripped vary from 292,000 tons to 303,000 tons and 195,000 tons to 211,000 tons during dry and rainy seasons respectively. Also, the tonnage of exposed and workable limestone varies from 2.07 million tons to 2.61 million tons and 1.5 million tons to 1.517 million tons during dry and rainy season respectively for 2004-2006. Therefore, stripping of overburden should be compensated during dry season to maintain the level of production.
Biomimetic Analysis of Insect Wing Kinematics for Flapping MAVs
Authors: Conn Andrew T. , Ling Chung Seng , Burgess Stuart C.
Published: June 2011

Despite significant interest for over a decade in developing micro air vehicles (MAVs) that mimic the flight performance exhibited by insects, no design has achieved this challenge. This has principally been due to limitations in actuation devices, which have resulted in constrained flapping motions that require conventional rudder and aileron control surfaces. Recent advances in “artificial muscle” actuation technologies mean that reproducing the complex wing kinematics of insects with sufficient power density for MAV flight has become feasible. Consequently, there is a need to analyse the wing kinematics of insects and how they are modulated for controlled, manoeuvrable flight. It is also important to understand how wing kinematics affect the unsteady aerodynamic mechanisms that crucially augment lift and thrust force production. In this paper a biomimetic analysis of insect wing kinematics based on established biological literature is presented, that aims to aid the development of agile and controllable flapping MAVs.
A Monte Carlo Analysis of Sensor Fusion Algorithm for the Estimation of Aerodynamic Angles in a Mini Aerial Vehicle
Authors: Ramprasadh C. , Arya Hemendra
Published: June 2011

An Extended Kalman Filter (EKF) fusion algorithm has been developed for estimating the aerodynamic angles in a Mini Aerial Vehicle (MAV). The knowledge on the aerodynamic angles would be helpful in designing control laws during the high angle of attack flights. This involves an algorithm that computes pseudo measurements of Angle of Attack (AOA) and Side Slip Angle (SSA) which are fused with typical sensor data for the estimation of aerodynamic angles. The current work focuses on testing the robustness of the estimation algorithm to uncertain aircraft parameters inherited from the manufacturing errors, assembly errors and also from prolonged usage of the aircraft. For this purpose, a Monte Carlo simulation has been carried out using number of randomly generated aircraft parameters in the flight simulation program, and the true states of the aircraft are generated. With few of these true states, a zero mean white Gaussian noise is added and the sensor data has been simulated. Using the simulated sensor data, the aerodynamic angles are estimated. It should be noted that the estimation algorithm has been provided with correct aircraft parameters, whereas the flight simulation has been carried out with randomly generated aircraft parameters. This paper brings out the robustness of the estimation algorithm to changes in the aircraft parameters propagated from manufacturing / assembly errors.
Forecasting Water Levels Using Artificial Neural Networks
Authors: Londhe Shreenivas N.
Published: June 2011

For all Ocean related activities it is necessary to predict the actual water levels as accurate as possible. The present work aims at predicting the water levels with a lead time of few hours to a day using the technique of artificial neural networks. Instead of using the previous and current values of observed water level time series directly as input and output the water level anomaly (difference between the observed water level and harmonically predicted tidal level) is calculated for each hour and the ANN model is developed using this time series. The network predicted anomaly is then added to harmonic tidal level to predict the water levels. The exercise is carried out at six locations, two in The Gulf of Mexico, two in The Gulf of Maine and two in The Gulf of Alaska along the USA coastline. The ANN models performed reasonably well for all forecasting intervals at all the locations. The ANN models were also run in real time mode for a period of eight months. Considering the hurricane season in Gulf of Mexico the models were also tested particularly during hurricanes.
Determination of Wave Spectrum with Intelligent Computing
Authors: Jain Pooja , Deo M C , Latha G , Rajendran V , Kumar V Sanil
Published: June 2011

Considerable works have been reported over last few decades on determination of wave spectral shapes. The resulting spectral models still involve large uncertainties, especially in handling spectra with two or more peaks. Hence studies indicating new options or re-examining some earlier ones in this regard should be welcome. This paper reports results from a fresh investigation carried out to determine wave spectral shapes with neural network (NN)s, support vector regression (SVR) and model tree (MT)s based on measurements made by wave buoys at two locations in Arabian Sea and Bay of Bengal off the Indian coast. It was found that in general all the three modern data driven approaches worked satisfactorily and they were more useful than the commonly adopted semi-empirical spectra. In order to obtain consistent and stable results the model calibration however needs to be made in a careful manner. Separate training over low and high sea states as well as for cases of double and multi-peaked spectra paid rich dividends in this regard. The spectra with two or more peaks were more efficiently handled by neural networks and SVR than MT. The operation of MT involving physical domain splits without non-linear transformations appeared to have over-simplified the underlying complexities. For obtaining more sustained results neural networks can be recommended, although the user's experience and confidence in using the other two methods may make them still successful in a given application.
Swell Propagation over Indian Ocean Region
Authors: Bhowmick Suchandra A. , Kumar Raj , Chaudhuri Sutapa , Sarkar Abhijit
Published: June 2011

Swells are the ocean surface gravity waves that have propagated out of their generating fetch to the distant coasts without significant attenuation. Therefore they contain a clear signature of the nature and intensity of wind at the generation location. This makes them a precursor to various atmospheric phenomena like distant storms, tropical cyclones, or even large scale sea breeze like monsoon. Since they are not affected by wind once they propagate out of their generating region, they cannot be described by regional wave models forced by local winds. However, their prediction is important, in particular, for ship routing and off shore structure designing. In the present work, the propagation of swell waves from the Southern Ocean and southern Indian Ocean to the central and northern Indian Ocean has been studied. For this purpose a spectral ocean Wave Model (WAM) has been used to simulate significant wave height for 13 years from 1993–2005 using NCEP blended winds at a horizontal spatial resolution of 1° × 1°. It has been observed that Indian Ocean, with average wave height of approximately 2–3 m during July, is mostly dominated by swell waves generated predominantly under the extreme windy conditions prevailing over the Southern Ocean and southern Indian Ocean. In fact the swell waves reaching the Indian Ocean in early or mid May carry unique signatures of monsoon arriving over the Indian Subcontinent. Pre-monsoon month of April contains low swell waves ranging from 0.5–1 m. The amplitudes subsequently increase to approximately 1.5–2 meters around 7–15 days prior to the arrival of monsoon over the Indian Subcontinent. This embedded signature may be utilized as one of the important oceanographic precursor to the monsoon onset over the Indian Ocean.
Virtual Tests on Axially and Rotationally Restrained Steel Column Under Fire
Authors: Kwasniewski Leslaw , Krol Pawel , Lacki Krzysztof
Published: June 2011

During a fire, some additional forces are imposed on columns due to varied thermal deformations in the neighboring structural components. Axial and rotational restraints can produce substantial loadings, which together with thermally reduced stiffness, can lead to its premature buckling and reduction of the column fire resistance. The paper presents a study on numerical modeling of steel columns subjected to prescribed axial and rotational restraints and time dependent temperatures. The problem is investigated using nonlinear finite element simulations carried out using the general purpose program LS-DYNA®. The paper focuses on model development and its verification and validation. Several modeling options and strategies for modeling thermal and mechanical boundary conditions have been considered. A numerical prediction of structural response during heating is compared with published experimental data.
Residual Mechanical Properties of Fibre Reinforced Concrete after Exposure to Elevated Temperature
Authors: Anumala Sharath , Sharma Umesh
Published: June 2011

This study aims to find out the compressive strength, split tensile strength, flexural strength, bond strength and permeability of steel fibre reinforced concrete subjected to elevated temperatures ranging from room temperature to 800°C. The specimens were exposed to a heating rate of 10°C/min and the target temperature was maintained for 2 hours to achieve a thermal steady state. A total of 210 specimens of plain and fibre reinforced concrete were tested under the test program. Crimped steel fibres were employed in the study at three volume fractions i.e. 0%, 1% and 1.5%. The results show degradation in strength properties with an increase in maximum heating temperature in both plain and steel fibrous concretes. However, when steel fibres are incorporated in the mix, an improvement of fire resistance and crack resistance at elevated temperature was observed. The results indicate a reduced deterioration in residual compressive, split tensile, flexural and bond strengths of fibre reinforced concrete specimens as compared to controlled plain concrete specimens when the temperature was increased from room temperature to 800°C. Residual permeability characteristics of fibre reinforced concrete show better performance than plain concrete.
Evaluation of Thermal Resistance of FRP Reinforced Concrete Beams in Fire
Authors: Rafi Muhammad , Nadjai Ali , Ali Faris , O'Hare Paul
Published: June 2011

Fibre reinforced polymer (FRP) bars are made of innovative materials and establishment of the fire resistance of FRP reinforced concrete (RC) is necessary for their widespread application. Experimental behaviours of Carbon FRP (CFRP) and Glass FRP (GFRP) bar RC beams at elevated temperatures have been investigated in this paper. Data are presented from fire tests of six simply supported beams that were fabricated using normal-weight concrete. The effects of varying load levels and FRP bar type were studied. The beams were designed over-reinforced and were tested in a floor furnace. A steel bar reinforced beam was used as control specimen. A rebar temperature of 500°C was selected as failure criterion for the beam. Non-linear temperature distribution across the beam cross section was observed. Temperature rise in the compression concrete was found insignificant and its mechanical properties were nearly unaffected. All beams met the failure criterion of critical rebar temperature of 500°C. The stiffness reduction in the GFRP and steel RC beams was nearly the same at elevated temperatures and was independent of load levels and/or bar modulus. The CFRP bar reinforced beams showed better stiffness characteristics compared to other beams.
Risk-Neutral Models for Emission Allowance Prices and Option Valuation
Authors: Carmona René , Hinz Juri
Published: June 2011

The existence of mandatory emission trading schemes in Europe and the United States, and the increased liquidity of trading on futures contracts on CO2 emissions allowances, led naturally to the next step in the development of these markets: These futures contracts are now used as underliers for a vibrant derivative market. In this paper, we give a rigorous analysis of a simple risk-neutral reduced-form model for allowance futures prices, demonstrate its calibration to historical data, and show how to price European call options written on these contracts.

This paper was accepted by Haitao Li, guest editor, finance.
Effect of somatostatin infusion on peptide YY secretion: studies in the acute and recovery phase of anorexia nervosa and in obesity
Authors: Rigamonti Antonello E , Cella Silvano G , Bonomo Sara M , Mancia Giuseppe , Grassi Guido , Perotti Mario , Agosti Fiorenza , Sartorio Alessandro , Müller Eugenio E , Pincelli Angela I
Published: June 2011

Objective

Changes in many gastrointestinal peptides, including the anorexigenic peptide YY (PYY), which is produced by L cells, occur in both anorexia nervosa (AN) and obesity (OB). High PYY levels are present in AN, whereas in morbid OB fasting and postprandial PYY secretion is blunted. Somatostatin (somatotropin release-inhibiting factor (SRIF)) reportedly inhibits plasma PYY concentrations in animals and healthy humans, but the effect of a SRIF infusion on spontaneous PYY secretion in AN and OB is unknown.

Methods

A total of 18 young women, seven with acute AN (A-AN), four with AN in the recovery phase (R-AN), and seven with morbid OB, were studied. All subjects underwent an infusion of SRIF (9 μg/kg i.v./h, over 60 min), with blood samples drawn before and at different time intervals after SRIF administration. Plasma PYY levels were measured at each time point.

Results

SRIF significantly inhibited plasma PYY concentrations in R-AN and OB, without affecting PYY titers in A-AN. In OB, the inhibitory effect of SRIF also persisted at 90 min. Withdrawal of SRIF infusion in R-AN resulted in a prompt restoration of basal plasma PYY levels, whereas termination of SRIF infusion in OB was followed by a slower increase of PYY titers toward baseline levels. After infusion, PYY Δ area under the curve (ΔAUC) in R-AN was significantly higher than those in A-AN and OB patients. A significant difference in PYY ΔAUC between A-AN and OB was present.

Conclusions

These results suggest the existence of a hypo- and hyper-sensitivity of L cells to the inhibitory effect of SRIF in A-AN and OB respectively.
Novel insights into the mechanisms of pregnancy establishment: regulation of prostaglandin synthesis and signaling in the pig
Authors: Waclawik Agnieszka
Published: June 2011

Ovarian progesterone induces essential changes leading to a temporary state of uterine receptivity for conceptus implantation. Estrogens secreted by the porcine conceptus on days 11 and 12 of pregnancy provide the initial signal for maternal recognition of pregnancy and maintenance of a functional corpus luteum (CL) for continued production of progesterone. As prostaglandins F2α(PGF2α) and E2(PGE2) exert opposing actions on the CL, a tight control over their synthesis and secretion is critical either for the initiation of luteolysis or maintenance of pregnancy. One of the supportive mechanisms by which conceptus inhibits luteolysis is changing PG synthesis in favor of luteoprotective PGE2. Conceptus PGE2could be amplified by PGE2feedback loop in the endometrium. In pigs, as in other species, implantation and establishment of pregnancy is associated with upregulation of expression of proinflammatory factors, which include cytokines, growth factors, and lipid mediators. The conceptus produces inflammatory mediators: interferon γ and interferon δ, interleukins IL1B and IL6, and PGs, which probably activate inflammatory pathways in the endometrium. The endometrium responds to these embryonic signals by enhancing further progesterone-induced uterine receptivity. Understanding the mechanisms of pregnancy establishment is required for translational research to increase reproductive efficiencies and fertility in humans and animals.
Calling the Heart by Name: Distinguished Eponyms in the History of Cardiac Anatomy
Authors: Conti Andrea A.
Published: June 2011

Many outstanding scientists have given their names to anatomic structures through time. Recently the use of eponyms has been at the center of a very interesting debate in the columns of prestigious medical journals. Even if some authors have questioned their adoption, not only do the names of great figures in the history of medicine appear inextricably linked to human body structures but they also have been widely adopted. Eponyms enliven medical study and practice by representing major mnemonic aids for students and learners and opening intriguing scenarios on the history of health. Given that physicians frequently are unaware of exactly "who stands behind" a name, this article presents a reconstruction of how eponyms for cardiac structures have developed through time and provides scientific profiles of the personages after whom heart districts have been named. The article is offered in the awareness that scientists of different countries and different ages have contributed to the elaboration of the knowledge of cardiac anatomy, according to their personal skills and to the health technology available in their particular times and places.
Interrupted Aortic Arch or Extreme Coarctation? A Case Report and Review of the Literature
Authors: Teskin Onder , Gullu A. Umit , Senay Sahin , Okten E. Murat , Alhan Cem
Published: June 2011

The hallmark feature of aortic interruption that is useful in differentiating it from aortic coarctation is the "complete absence" of continuity between both parts of the interrupted segment. In this study, we reviewed the 28 patients diagnosed with isolated interrupted aortic arch (IAA) who reached adult age (> 20 years), aimed to review the validity of the Celoria-Patton classification in the literature, and reported the first microscopic pathology of the IAA in an adult.
Why Choose Cardiothoracic Surgery as a Career?
Authors: Gopaldas Raja R. , Bakaeen Faisal G. , Chu Danny , Coselli Joseph S. , Cooley Denton A.
Published: June 2011

The future of cardiothoracic surgery faces a lofty challenge with the advancement of percutaneous technology and minimally invasive approaches. Coronary artery bypass grafting (CABG) surgery, once a lucrative operation and the driving force of our specialty, faces challenges with competitive stenting and poor reimbursements, contributing to a drop in applicants to our specialty that is further fueled by the negative information that members of other specialties impart to trainees. In the current era of explosive technological progress, the great diversity of our field should be viewed as a source of excitement, rather than confusion, for the upcoming generation. The ideal future cardiac surgeon must be a "surgeon-innovator," a reincarnation of the pioneering cardiac surgeons of the "golden age" of medicine. Equipped with the right skills, new graduates will land high-quality jobs that will help them to mature and excel. Mentorship is a key component at all stages of cardiothoracic training and career development. We review the main challenges facing our specialty�length of training, long hours, financial hardship, and uncertainty about the future, mentorship, and jobs�and we present individual perspectives from both residents and faculty members.
Temporary Extracorporeal Circulatory Support and Pulmonary Embolectomy for Catastrophic Amniotic Fluid Embolism
Authors: Firstenberg Michael S. , Abel Erik , Blais Danielle , Turner Katja , Halim-Armanios Mona , Dimitrova Galina , Cohn David , Samuels Philip
Published: June 2011

Amniotic fluid embolism is usually a life-threatening complication of an otherwise healthy pregnancy. Medical management of the coagulopathy and cardiovascular collapse is challenging and is often unsuccessful. We present a case and advocate the use of temporary circulatory support and pulmonary embolectomy in what would otherwise have been a fatal scenario.
Transcatheter Aortic Valve Implantation after Previous Mechanical Mitral Valve Replacement: Expanding Indications?
Authors: Beller Carsten J. , Bekeredjian Raffi , Krumsdorf Ulrike , Leipold R�diger , Katus Hugo A. , Karck Matthias , Rottbauer Wolfgang , Kallenbach Klaus
Published: June 2011

Background: Cardiac operation for severe aortic stenosis after previous mitral valve replacement is a surgical challenge in older patients with multiple morbidities. Transcatheter aortic valve implantation (TAVI) after previous mechanical mitral valve replacement has been considered a high-risk procedure, owing to possible interference with the mitral valve prosthesis.

Methods: Since August 2008, 5 female high-risk patients with severe aortic stenosis and previous mitral valve replacement (mean � SD age, 80 � 5.1 years; logistic EuroSCORE, 39.3% � 20.5%) underwent TAVI with a pericardial xenograft valve that was fixed with a stainless steel, balloon-expandable stent (Edwards Lifesciences SAPIEN). We used a transapical approach in 4 patients and a transfemoral approach in 1 patient. Transesophageal echocardiography and multidetector computed tomography were used for preoperative planning and assessment of operation feasibility. The mean distance between the aortic annulus and the mitral valve prosthesis was 10 � 1 mm (range, 9-11 mm).

Results: TAVI was performed successfully in all 5 patients. There was no direct or functional interference with the mechanical mitral valve prostheses. Echocardiography revealed good valve function with no more than mild paravalvular incompetence early in the postoperative period and during routine follow-up. There were no neurologic events. After an initially uneventful course with good aortic valve function at the most recent echocardiography evaluation, however, 2 of the patients died from fulminant pneumonia on postoperative days 4 and 48.

Conclusion: TAVI is technically feasible in high-risk patients after previous mechanical mitral valve replacement; however, careful patient selection is mandatory with respect to preoperative clinical status and anatomic dimensions regarding the distance between aortic annulus and mitral valve prosthesis.
Important aspects of end-of-life care. Survey of patients visiting the primary care office
Authors: Csikós Ágnes , Nagy Lajos , Busa Csilla , Kállai János
Published: June 2011

Introduction: Death and dying are still taboo topics in Hungary. The care of the dying, the adequate relief of their symptoms and the psychosocial support of both patients and their caregivers are not yet well addressed. Aims: Authors obtained information about the feelings and thoughts of patients on death and dying, and about their expectations for end-of-life care. Methods: Mailed questionnaire was send to a convenience sample of 29 adult primary care offices where a total of 845 unselected patients completed the questionnaire. Results: More than two thirds (69%) of respondents would like to receive end of life care in their home. Only 19% of respondents would prefer to die in a hospital. Respondents’ greatest fear was to lose their autonomy (55%). The second most noted concern was fear from pain (38%). According to 93% of the participants, truth telling is very important in the event of terminal illness. Conclusions: Hungarian patients prefer to receive end of life care in their home. Our data support the need for improvement in three primary areas, physician communication skills, pain and symptom management, and expansion of home hospice care. Orv. Hetil., 2011, 152, 1082–1092.
Gram-negative bacteremia in neutropenic patients with hematologic disorders. Experiences with prophylactic use of fluoroquinolones
Authors: Sinkó János , Cser Viktória , Konkoly Thege Marianne , Masszi Tamás
Published: June 2011

Gram-negative bacteremia remains a severe complication of neutropenia with a high mortality rate. For high-risk patients prophylactic use of fluoroquinolones is recommended as a preventive strategy. Aims: To study the effect of fluoroquinolone prophylaxis on Gram-negative bacteremia. Methods: In the retrospective survey Gram-negative bacteremic episodes occurring in a centre for hematology and stem cell transplantation were studied. Data from the year before and after instituting prophylaxis were compared with regard to the incidence of blood stream infections, spectrum of pathogens, rate of fluoroquinolone resistance and all cause mortality of affected patient population. Results: Only a slight decrease in the incidence of Gram-negative bacteremia was seen (ARR: 0.024) after the introduction of fluoroquinolone prophylaxis. Spectrum of pathogens remained unchanged. However, the proportion of fluoroquinolone resistant Gram-negative isolates increased markedly (from 24% to 59%, p = 0.001), especially fluoroquinolone resistant E. coli strains became more prevalent (from 16% to 75%, p<0.001). All cause mortality at 7 and 30 days remained the same or increased insignificantly. Conclusions: With the current epidemiological background none of the expected benefits from the fluoroquinolone prophylaxis could be proven, whereas, the rate of fluoroquinolone resistance increased markedly. A reconsideration of present prophylactic strategies is suggested. Orv. Hetil., 2011, 152, 1063–1067.
Effects of magnesium supplementation on the calcium and magnesium levels, redox homeostasis in normolipidemic and alimentary induced hyperlipidemic rats
Authors: Virág Viktória , May Zoltán , Kocsis Ibolya , Blázovics Anna , Szentmihályi Klára
Published: June 2011

Magnesium supplementation is quite popular because of intention of health and healthy lifestyle. However, there is no information on the metabolic effects of magnesium supplementation in healthy people and in different diseases. Aims: Authors examined the effects of magnesium-malate on calcium, magnesium levels, and antioxidant parameters in normolipidemic and hyperlipidemic rats. Methods: Male Wistar rats (n = 40; 150-200 g) were divided into 4 groups (control, control-treated, hyperlipidemic, hyperlipidemic-treated). Rats in the control and control-treated groups were fed with normal diet, while hyperlipidemic and hyperlipidemic-treated groups were fed with fat rich diet (2% cholesterol, 20% sunflower oil, 0.5% cholic acid). After the 9-day-long diet the following parameters were measured: routine laboratory parameters with automatic analysator, metal content using ICP-OES, and redox-parameters using spectrophotometric and luminometric methods. Results: Magnesium-malate failed to produce significant changes in the measured parameters in control animals in most cases. Magnesium-malate decreased significantly serum glucose concentration, alkaline phosphatase and amylase activities in the hyperlipidemic group. Significantly low induced chemiluminescent activity was measured in the plasma and erythrocytes of hyperlipidemic group. The magnesium supplementation did not increase significantly magnesium concentration in different organs although the calcium/magnesium concentration ratio was decreased. Conclusions: In control animals there was no significant change in the measured parameters in most cases after dietary supplementation with a large amount of magnesium for a short period of time, but magnesium supplementation affected the metal homeostasis, routine laboratory parameters and redox system in hyperlipidemic animals. Although several changes were favorable, it should be emphasized that magnesium supplementation must be applied watchfully particularly in metabolic diseases. Orv. Hetil., 2011, 152, 1075–1081.
Assessment of the scientific-technological production in molecular biology in Brazil (1996-2007): the contribution of genomics programs
Authors: Meneghini Rogério , Gamba Estêvão C.
Published: June 2011

Several genome sequencing programs were launched in Brazil by the end of the nineties and the early 2000s.The most important initiatives were supported by the ONSA program (http://watson.fapesp.br/onsa/Genoma3.htm) and aimed at gaining domain in genomic technology and bringing molecular biology to the state of art. Two mainsets of data were collected in the 1996-2007 period to evaluate the results of these genome programs: the scientific production (Scopus and Web of Science databases) and the register of patents (US Patent and Trademark Office), both related to the progress of molecular biology along this period. In regard to the former, Brazil took a great leap in comparison to 17 other developed and developing countries, being only surpassed by China. As to the register of patents in the area of molecular biology, Brazil's performance lags far behind most of the countries focused in the presentstudy, confirming the Brazilian long-standing tendency of poor achievements in technological innovations when compared with scientific production. Possible solutions to surpass this inequality are discussed.
Anti-inflammatory, antinociceptive, and antipyretic effects of methanol extract of Cariniana rubra stem bark in animal models
Authors: Santos Edson N. , Lima Joaquim C.S. , Noldin Vânia F. , Cechinel-Filho Valdir , Rao Vietla S. N. , Lima Evangelista F. , Schmeda-Hirschmann Guillermo , Sousa Jr. Paulo T. , Martins Domingos T.O.
Published: June 2011

Cariniana rubra Miers (Lecythidaceae), popularly known as "jequitibá-vermelho'', is a large Brazilian tree whose bark is used in infusion and decoction for the treatment of inflammatory conditions. This study aims to assess the anti-inflammatory, antinociceptive, and antipyretic effects of Cariniana rubra methanolic stem bark extract (EM Cr) using experimental animals. Anti-inflammatory activity of EM Cr was tested on carrageenan and dextran-induced rat paw edema, carrageenan-induced pleurisy in rats and acetic acid-increase vascular permeability in mice. Antinociceptive and antipyretic activities were evaluated using acetic acid-induced writhing, formalin and hot-plate tests in mice, as well as brewer's yeast-induced pyrexia in rats. The extract inhibitied carrageenan and dextran-induced edema, reduced exudate volume and leukocyte migration on the carrageenan-induced pleurisy and on the vascular permeability increase induced by acetic acid. The EM Cr inhibited nociception on the acetic acid-induced writhing and in the second phase of formalin test, and decreased rectal temperature. It was, however, inactive against thermal nociception.Phytochemical analysis with EM Cr showed the occurrence of saponins, triterpenes, sterols and phenolic compounds. Phytosterols (β-sitosterol, stigmasterol), pentacyclic triterpenes (α- and β-amyrin as a mixture), arjunolic acid, a phytosterol glycoside (sitosterol 3-O-β-D-glucopyranoside), and triterpenoid saponins (28-β-glucopyranosyl-23-O-acetyl arjunolic acid; 3-O-β-glucopyranosyl arjunolic acid and 28-O-[α-L-Rhamnopyranosyl-(1→2)-β-glucopyranosyl]-23- O-acetyl arjunolic acid) were the main identified compounds. It can be presumed that EM Cr caused their effects by inhibiting the liberation and/or action of different inflammatory mediators. These findings support the traditional use of Cariniana rubra preparations to treat inflammation.
Motor hemiplegia and the cerebral organization of movement in man: II. The myth of the human extrapyramidal system
Authors: Oliveira-Souza R.
Published: June 2011

Following a brief review of the concept of extrapyramidal system, clinical and anatomic evidence is presented against its relative prominence in man. It is proposed that the greatest part of those structures traditionally labeled as extrapyramidal effects its respective functional activities by way of the pyramidal tracts themselves. Such structures, centered around the basal nuclei, the cerebellum and possibly, the limbic areas of the prosencephalon are, according to the present suggestion, indeed, pre pyramidal. This model is based upon the clinical analysis of patients and agrees with more than one century of anatomic verifications in human brains, favoring the notion of the singularity of the human brain.
Atividade epiléptica focal durante sono induzido na síndrome de Lennox-Gastaut secundária
Authors: Speciali J. G. , Resende L. A. L.
Published: June 2011

Quinze pacientes com síndrome de Lennox-Gastaut secundária foram submetidos a exames clínicos e eletrencefalográficos mensais por períodos de tempo que variaram de 1 a 9 anos. Os exames eletrencefalográficos foram realizados durante sono induzido por barbitúrico. Doze pacientes apresentaram atividade epiléptica focal. No presente trabalho descrevemos a localização, morfologia e freqüência dos paroxismos epilépticos focais.
L-dopa, biperideno e excreção sebácea na doença de Parkinson
Authors: Villares João C. B.
Published: June 2011

A excreção sebácea frontal de 47 parkinsonianos «de novo» antes e após tratamento com anticolinérgico (biperideno), levodopa + IDAA e bromocriptina foi avaliada pelo método do ácido ósmico. Outros 100 parkinsonianos sob terapêutica crônica com biperideno, levodopa + IDAA ou associação de ambos foram avaliados. Parkinsonianos «de novo» do sexo masculino apresentam valores de excreção sebácea significativamente mais elevados em relação às mulheres. Verificou-se que biperideno não foi eficaz em reduzir o grau de excreção sebácea. Já, em relação a L-dopa + IDAA constatou-se que a droga foi efetiva em reduzir o grau de excreção sebácea (NC e TRE) tanto no sexo masculino quanto no feminino. Em relação à bromocriptina (l0mg/dia) também constatou-se que houve redução da excreção sebácea no sexo masculino. Correlação significante positiva foi verificada entre o NC, tremor, bradicinesia, hipertonia, alterações da marcha e postura e incapacidade funcional, entre parkinsonianos do sexo masculino e faixa etária 50-59 anos, no período pré-tratamento. Após o período de tratamento não mais havia correlação entre excreção sebácea e as manifestações neurológicas da doença de Parkinson. Entre parkinsonianos sob terapêutica crônica verificou-se correlação positiva e significante entre excreção sebácea e bradicinesia. O grau de excreção sebácea de parkinsonianos «de novo» sem tratamento não difere do grau daqueles sob tratamento crônico, exceção feita a parkinsonianos com idade > 60 anos, em que verificou-se maior grau de excreção sebácea (NC e TRE) em relação ao mesmo sexo e faixa etária, sem tratamento. L-dopa + IDAA foi eficiente em reduzir o grau de excreção sebácea de parkinsonianos «de novo», tornando-a significativamente menor em relação àqueles sob tratamento crônico. Não há diferença entre o grau de excreção sebácea de parkinsonianos «de novo» sem tratamento e parkinsonianos sob associação de drogas cronicamente. A possibilidade de ser a disfunção dopaminérgica hipotalâmica a origem do aumento da excreção sebácea em parkinsonianos é discutida, além de serem comparados os resultados apresentados aos registrados na literatura.
Alterações da junção neuromuscular em miopatias experimentais no camundongo
Authors: Torres Luiz Fernando Bleggi
Published: June 2011

As alterações morfológicas observadas em junção neuromuscular de dois modelos de miopatia em camundongos são estudadas por métodos histoquímicos para demonstrar atividade da enzima acetilcolinesterase e por microscopia eletrônica. Em ambas as situações os resultados obtidos são similares, indicando que a junção neuromuscular permanece intacta mesmo quando a fibra que inerva está sofrendo necrose. Em fibras musculares regeneradas há acentuada simplificação das pregas pós-sinápticas, com redução de até 50% dos valores normais, comprovado por estudos morfométricos. A ausência de repercussões fisiológicas ou clínicas detectáveis nesses modelos, apesar da significativa hipotrofia da membrana pós-sináptica, sugere que a exuberante quantidade de pregas pós-sinápticas normalmente encontradas nas junções mioneürais pode representar mecanismo anatômico de segurança na transmissão química neuromuscular.
NCPAP for the treatment of obstructive sleep apnea
Authors: Silva Ademir Baptista , Lemmi Hélio
Published: June 2011

Nasal continuous positive airway pressure (NCPAP) represents a real advance in the management of obstructive sleep apnea (OSA). Our data show that except for awakenings, all sleep and respiratory parameters were significantly improved (p<0.05) in favor of the group treated with NCPAP. A main problem with NCPAP is the acceptance by the patient; it also may disturb the sleep, at least, on short term basis and, in a small number of patients, it does not correct the apneas. In our patients series, males responded better to NCPAP than females.
Considerações sobre as relações neurais e etológicas na avaliação das alterações do controle motor: I. Substratos neurais da motricidade
Authors: Garcia-Cairasco Norberto
Published: June 2011

O movimento é a expressão final da ativação harmônica de múltiplos sistemas cerebrais e musculares. Na natureza ele medeia respostas primárias de profundo valor adaptativo como a reprodução, predação e fuga, entre outras. A descrição dos movimentos como atos ou padrões motores correspondeu inicialmente à Etologia. Com o avanço nas Neurociências, hoje é proposta abordagem neuroetológica para a pesquisa nesta área. Quando se apresentam disfunções do movimento, praticamente os mesmos sistemas musculares e cerebrais são utilizados, só que de maneira aberrante, tanto no tempo quanto no espaço. Nesta revisão são ilustrados os principais sistemas envolvidos no controle motor normal, particularmente córtex, gânglios basais, cerebelo, tronco cerebral, medula, periferia muscular receptora e efetora.
Considerações sobre as relações neurais e etológicas na avaliação das alterações do controle motor: II. Modelos experimentais
Authors: Garcia-Cairasco Norberto
Published: June 2011

A utilização de modelos experimentais de disfunções motoras é discutida como instrumento para o conhecimento normal e patológico do funcionamento dos sistemas motores. São apresentados neste trabalho vários modelos experimentais como os de hemiplegia, acinesia, parkinsonismo e epilepsia.
Dor faríngea durante punção suboccipital lateral: lateral suboccipital puncture
Authors: Rossitti Sandro L. , Araújo João Flávio M. , Zuiani A. Roberto , Balbo Roque J.
Published: June 2011

Foi observada queixa de dor orofaríngea em cinco pacientes, conscientes e bons informantes, durante realização de punção suboccipital lateral da cisterna magna para mielo-grafia e/ou coleta de liqüido cefalorraqueano. São revisadas as anastomoses dos nervos cranianos inferiores, com ênfase às relações do primeiro nervo ín.) cervical (Cl) com o gânglio cervical superior da cadeia simpática e com o n. acessório (n. XI), a convergência anatômica sensitiva no subnúcleo caudal do núcleo do tracto espinhal do n. trigêmeo e sua importância na cirurgia funcional da dor. É sugerido que a referência de dor faríngea durante a punção suboccipital lateral se deva a estimulação de fibras aferentes viscerais de Cl ou de ramos comunicantes cinzentos do gânglio cervical superior para Cl.
Hematoma primário do tronco cerebral: considerações a propósito de um caso
Authors: Salomão J. Francisco , Vialogo Josué G. , Lynch José Carlos
Published: June 2011

Os autores relatam o caso de hematoma primário do tronco cerebral em uma paciente de 48 anos, normotensa. A evolução arrastada do processo sugeria tumor de tronco, sendo o diagnóstico de hematoma estabelecido por exploração cirúrgica. Discute-se a origem desses hematomas, conseqüentes à ruptura de angiomas crípticos ou microangiomas, bem como o diagnóstico diferencial com hemorragias hipertensivas do tronco cerebral, patologia de prognóstico sombrio, na maioria das vezes sem indicação cirúrgica. Dão ênfase à necessidade da sistemática exploração das lesões expansivas do tronco cerebral, principalmente em se tratando de indivíduos jovens e normotensos.
Epilepsia na síndrome do anel do cromossomo 14
Authors: Duarte Maria Herbenia O. , Lison Michel Pierre , Ferrari Iris , Soares Lucia R. M. , Fernandes Regina M. F.
Published: June 2011

Os autores relatam o caso de paciente com anel do cromossomo 14. Com base neste e na revisão de 28 casos publicados, determinam a freqüência dos sinais e sintomas clínicos, salientam a incidência constante e precoce de crises epilépticas e descrevem suas características. Enumeram as malformações congênitas associadas e chamam a atenção para sua importância na indicação do cariótipo e conseqüente detecção de novos casos.
Estado vegetativo-alfa persistente
Authors: Oliveira-Souza R. , Gusmão D. L. , Figueiredo W. M. , López J. R. R. A. , Mello J. S. , Ribeiro S. A. , Alvarenga H.
Published: June 2011

Após revisão sumária dos conceitos de «coma» e «coma-alfa», relatamos o caso de uma paciente com doença de Pick provável que, nos estágios terminais da doença, permaneceu várias semanas em estado vegetativo com EEG de vigília normal e reativo à fotoestimulação. Enfatizamos (a) algumas das implicações do aspecto dos olhos nesses pacintes, (b) a importância de distinguir a atividade alfa do ritmo alfa verdadeiro e (c) sugerimos que a categoria «coma-alfa» inclua apenas aqueles com afecções do tegmento da junção pontomesencefálica, de qualquer natureza, reservando a designação «estado vegetativo-alfa» persistente para os que se encontrem em estado vegetativo e exibam EEG em virgília idêntico ao normal.
Oligodendroglioma do ângulo ponto cerebelar: evolução de 16 anos. Revisão da literatura e considerações sobre a patologia
Authors: Carvalho Filho Adolpho , Salame José Massoud
Published: June 2011

Os autores, após minudente pesquisa bibliográfica, levantaram 43 casos de oligodendroglioma na fossa posterior. Destes, só dois eram de localização no ângulo ponto cerebelar. Os autores acrescentam mais um caso desta patologia, nesta rara localização, chamando a atenção para sua evolução comprovada durante 16 anos.
Miastenia grave familiar: relato de caso em gêmeas idênticas
Authors: Dias-Tosta Elza , Aguiar Maria de Fátima Machado , Barbosa Hamilton , Vilela Suzete Silva Leme
Published: June 2011

Trata-se do sétimo relato da literatura mundial de casos de miastenia gravis em gêmeos homozigóticos em que ambos são acometidos. O homozigotismo foi provado com certeza por estudo de HLA e a forma adquirida da doença foi provada por determinação de níveis elevados de anticorpos anti-receptor de acetilcolina, havendo também níveis elevados de anticorpos antimúsculo estriado, sem outras evidências de timoma.
Organización y tendencias del conocimiento de enfermería en Chile
Authors: Mendoza Parra Sara , Klijin Tatiana Paravic
Published: June 2011

Estudio cuantitativo, descriptivo y retrospectivo que exploró la organización del conocimiento de la Enfermería Chilena y sus tendencias. El universo estuvo constituido por reportes científicos publicados en las revistas de enfermería chilenas entre 1965 y 2003 (N=214). Se utilizó pauta basada en la CIPE, criterios de Nogueira e indicaciones de cienciometría. El análisis con medidas estadísticas de tendencia central fueron manejadas con SPSS. Algunos resultados fueron: el sujeto de estudio más frecuente fue el profesional de enfermería y la tendencia es enfocarse a las necesidades en salud de las personas adultas y en riesgo de enfermar. Se observa: las publicaciones tienen poco sustento teórico de enfermería, "Ciencia y Enfermería" es la revista que exhibe la mejor calidad científica.