bluuebunny/crossref_metadata_2025 huggingface dataset:
A study of the mechanical properties of nanowires using nanoindentation
Authors: Feng Gang , Nix William D. , Yoon Youngki , Lee Cheol Jin
Published: April 2006

A nanoindenter XP with scanning capabilities was used to perform nanoindentations on GaN and ZnO nanowires with radii in the range of 20–50nm, positioned on a silicon substrate and bonded to the substrate at their ends with platinum. Since the geometry of indentation of a nanowire differs significantly from the indentation of a half-space, the standard Oliver-Pharr method [W. C. Oliver and G. M. Pharr, J. Mater. Res. 7, 1564 (1992)] of analysis may not be used. A two interface contact model has been developed for the nanoindentation of a nanowire on a flat substrate, with the two interfaces, indenter/nanowire and nanowire/substrate, being in a series. The contact at the indenter/nanowire interface is modeled as an elliptical contact at the sphere (indenter)/cylinder interface. The contact at the nanowire/substrate interface is modeled as a contact at the cylinder/half-space interface under some concentrated forces applied on top of the cylinder. Under these latter conditions the cylinder may be expected to recede from the half-space when the load is applied. In order to predict the contact stiffness for the two interfaces, the theories of Hertzian contacts and receding contacts have been reviewed, generalized, and used. Considering the possible adhesion at the nanowire/substrate interface and the fixed ends of the nanowire, we have considered two limits for the contact at the nanowire/substrate interface: one with and one without separation at the interface; thus, we obtain two bounds for the contact stiffness and hardness. The model has been used to analyze the nanoindentation data for GaN and ZnO nanowires. We found that the hardness of the GaN nanowire is 46.7±5.6GPa, which is much higher than that of the ZnO nanowire, 3.4±0.9GPa. We also found that the Oliver-Pharr hardness [W. C. Oliver and G. M. Pharr, J. Mater. Res. 7, 1564 (1992)] may be the rough lower bound of the hardness and the Joslin-Oliver hardness [D. L. Joslin and W. C. Oliver, J. Mater. Res. 5, 123 (1990)] may be the rough upper bound of the hardness.
Evidence of the magnetoimpedance effect up to microwave frequencies in polycrystalline La0.7Sr0.3MnO3 films
Authors: Stanescu D. , Xavier P. , Richard J. , Dubourdieu C.
Published: April 2006

We present broadband measurements of the magnetoimpedance of polycrystalline La0.7Sr0.3MnO3 films grown on silicon as a function of three parameters: (i) the frequency (0–1GHz), (ii) the temperature (4–275K), and (iii) the applied magnetic field (0–6T). In this paper it is evidenced that the magnetoresistive effect still exists up to 1GHz. The impedance variation with the frequency is well modeled considering that the polycrystalline film is equivalent to a random resistive-capacitive network. Similar behaviors of the impedance versus temperature variation are observed in dc and high frequency range.
Dynamic properties of flexural beams using a nonlocal elasticity model
Authors: Lu Pin , Lee H. P. , Lu C. , Zhang P. Q.
Published: April 2006

In this paper, a nonlocal Bernoulli-Euler beam model is established based on the theory of nonlocal elasticity. Frequency equations and modal shape functions of beam structures with some typical boundary conditions are derived based on the model. The corresponding dynamic properties are presented and discussed in detail, which are shown to be very different from those predicted by classic elasticity theory when nonlocal effects are significant. The results can be applied to modeling and characterization of size-dependent mechanical properties of micro- or nanoelectromechanical system (MEMS or NEMS) devices.
LIFE BEYOND DEATH: READING FOR THE DEMONIC IN THE TEXTS OF MODIANO AND JAPRISOT
Authors: Best Victoria
Published: April 2006

In classic crime fiction the demonic is located first in the crime, which mobilizes the reparative function of narrative, and then in the criminal, whose identification ensures the security of the community. The pleasure of reading such texts is bound up with the localization and erasure of the demonic forces. However, the contemporary
roman noir
in France (particularly the works of Modiano and Japrisot) rewrites the elements of crime fiction, presenting texts without these triumphant conclusions — texts in which the protagonist is simultaneously victim, criminal and detective. They are, I suggest, part of an alternative tradition of the demonic in French fiction, which understands its force to be chronic rather than acute, a structural component of subjectivity. In this article I explore a psychoanalytic reading of these protagonists and of the demonic in its chronic manifestation, drawing on Žižek's reading of Lacan and placing this in contradistinction to the work of Freud. I shall also reconsider the reading experience, proposing, as an alternative to the plot-driven desire for closure, the possibility of reading for the demonic, with its concomitant desire for unpleasure and sustained radical ambiguity.
Erythema induratum of Bazin in an infant after Bacille Calmette‐Guerin vaccination
Authors: INOUE Tomoko , FUKUMOTO Takaya , ANSAI Shinichi , KIMURA Tetsunori
Published: April 2006

We report the first case of erythema induratum of Bazin (EIB) after Bacille Calmette‐Guerin (BCG) vaccination in an infant. The patient developed recurrent multiple erythematous and subcutaneous nodules on his legs 2 months after a BCG vaccination. He had no other symptoms or family history of tuberculosis (TB). Histopathological findings revealed a granulomatous lobular panniculitis. EIB often appears as a chronic, nodular eruptions that frequently occur on the lower legs of females with tuberculin hypersensitivity. To date, only a few cases of infants with EIB have been reported. There have been no clinical reports of EIB after BCG vaccination. Our case suggests that Mycobacterium bovis in the BCG vaccination may have caused EIB.
Extrinsic allergic alveolitis
Authors: ISMAIL Tengku , MCSHARRY Charles , BOYD Gavin
Published: April 2006

Abstract: Extrinsic allergic alveolitis (also known as hypersensitivity pneumonitis) is caused by repeated inhalation of mainly organic antigens by sensitized subjects. This induces a hypersensitivity response in the distal bronchioles and alveoli and subjects may present clinically with a variety of symptoms. The aims of this review are to describe the current concepts of the immunological response, the diverse clinical presentation of this disease, the relevant investigations and management, and areas for future studies.
Evaluation of patients followed up in a cigarette cessation clinic
Authors: AKKAYA Ahmet , ÖZTÜRK ÖNder , COBANOĞLU Hafize , BIRCAN Haci Ahmet , ŞIMŞEK ŞEner , ŞAHIN ÜNal
Published: April 2006

Objectives:  The aim of this study was to evaluate the demographic characteristics and factors determining success in a smoking cessation clinic in smokers who completed a 1‐year follow up.

Method:  A total of 349 patients were assessed retrospectively.

Results:  There were 238 men (mean age: 41 ± 13.5 years) and 111 women (mean age: 37 ± 11.9 years) (t‐test P = 0.004). The average age at which they began to smoke, number of years of smoking and the number of cigarettes/day were 17.5 ± 5.2 years (median 17), 22.1 ± 13.3 years, 23.5 ± 12.0, respectively. Cigarette smoking was mostly observed in university graduates (56.8%) and a moderate negative correlation existed between education status and smoking duration (r = −0.27, P = 0.000). Patients with a Fagerström Tolerance Questionnaire score of ≥6 and those exposed to cigarette smoke in childhood tended to commence and become commited smokers later in life (χ2 = 4.915, P = 0.027). In all, 151 patients (43.26%) were successful in quitting (χ2 = 36.4, P = 0.000). Of these, 87 (24.93%) used medication such as nicotine patches (13.5%), bupropion (7.2%), nicotine patches + bupropion (4.3%) and 64 (18.33%) refused medication, but came for professional support.

Conclusion:  Increased education level, behavioural therapy and intensive motivational support, follow‐up visits and phone calls all appear to play important roles in smoking cessation. Families also play a major role.
Diffuse panbronchiolitis in East Asia
Authors: AZUMA Arata , KUDOH Shoji
Published: April 2006

Abstract:  Diffuse panbronchiolitis is characterized by chronic sinobronchial infection and diffuse bilateral centrilobular lesions consisting of peribronchial infiltration of inflammatory cells. At present, it is known that diffuse panbronchiolitis is relatively restricted to East Asia. This uneven distribution is suspected to be highly associated with genetic predisposition located between human leucocyte antigen‐A and ‐B loci. Low‐dose, long‐term macrolide therapy for the disease was suggested from a detailed observation of a single case that significantly improved by erythromycin therapy. Otherwise simple bactericidal activity of macrolides has been assumed as a candidate because of their clinical effect on the pathogenesis. In the last 10 years, the possible mechanism underlying the effectiveness of macrolide therapy has been dynamically investigated. To understand the pathological features and potential targets for macrolides in diffuse panbronchiolitis, the authors introduce the incidence of diffuse panbronchiolitis in East Asia, the profile of the disease and then trace the history of macrolide therapy in this review. The proposed mechanism of action includes the inhibition of excessive mucus and water secretion from the airway, the inhibition of neutrophil, and sometimes of lymphocyte and macrophage accumulating in the airway, the inhibition of transcription factors expressing several cytokines and the attenuation of bacterial virulence. Intracellular mechanisms of the action of macrolide are a hot topic of interest in research. The anti‐inflammatory activity of macrolides is independent of their bactericidal effect, and a new anti‐inflammatory analogue without antimicrobial activity should be developed to minimize the emergence of macrolide‐resistant microorganisms and to maintain the safety of this treatment.
Correlation study between optical coherence tomography and fluorescein angiography in post‐membrane peeling recalcitrant macular oedema
Authors: Liu David TL , Lee Vincent YW , Kwok Madeline KM , Chan Wai‐Man , Lam Dennis SC
Published: April 2006

Abstract

Correlation between optical coherence tomography and fluorescein angiography in a post‐membrane peeling patient indicated a surgically disturbed retinal vessel as the cause of recalcitrant macular oedema.
The Relationship between Poor Numerical Abilities and Subsequent Difficulty in Accumulating Statistical Knowledge
Authors: Gnaldi Michaela
Published: April 2006

Mathematics lecturers have long expressed concern about their students’ poor mathematical background and the effect this has on performance in first mathematics courses at university level. This article explores a similar concern about students’ numeracy in a statistics course for psychologists.
Protection of plants from frost using hydrophobic particle film and acrylic polymer
Authors: FULLER M P , HAMED F , WISNIEWSKI M , GLENN D M
Published: April 2006

Frost damage to potatoes, grapevine and citrus plants was assessed following treatment with either an acrylic polymer (Antistress™) or with a hydrophobic particle film (CM‐96–018). In large freezing tests, the application of the hydrophobic particle film consistently led to less damage whilst the acrylic polymer led to the same amount or more damage when compared to control plants. Detailed examination of the freezing of leaves of all three species using infrared thermal imaging revealed that the hydrophobic particle film delayed the entry of ice from a frozen water droplet containing ice nucleating active bacteria and in some cases for the complete duration of the frost test. In contrast, the acrylic polymer was only able to influence the time of ice nucleation of the leaves of citrus plants. It was concluded that the hydrophobic particle film shows considerable promise as a frost protectant applied to susceptible crops just prior to a freezing event.
Downstream regulatory element antagonistic modulator regulates islet prodynorphin expression
Authors: Jacobson David A. , Cho Julie , Landa Luis R. , Tamarina Natalia A. , Roe Michael W. , Buxbaum Joseph D. , Philipson Louis H.
Published: April 2006

Calcium-binding proteins regulate transcription and secretion of pancreatic islet hormones. Here, we demonstrate neuroendocrine expression of the calcium-binding downstream regulatory element antagonistic modulator (DREAM) and its role in glucose-dependent regulation of prodynorphin (PDN) expression. DREAM is distributed throughout β- and α-cells in both the nucleus and cytoplasm. As DREAM regulates neuronal dynorphin expression, we determined whether this pathway is affected in DREAM−/−islets. Under low glucose conditions, with intracellular calcium concentrations of <100 nM, DREAM−/−islets had an 80% increase in PDN message compared with controls. Accordingly, DREAM interacts with the PDN promoter downstream regulatory element (DRE) under low calcium (<100 nM) conditions, inhibiting PDN transcription in β-cells. Furthermore, β-cells treated with high glucose (20 mM) show increased cytoplasmic calcium (∼200 nM), which eliminates DREAM's interaction with the DRE, causing increased PDN promoter activity. As PDN is cleaved into dynorphin peptides, which stimulate κ-opioid receptors expressed predominantly in α-cells of the islet, we determined the role of dynorphin A-(1–17) in glucagon secretion from the α-cell. Stimulation with dynorphin A-(1–17) caused α-cell calcium fluctuations and a significant increase in glucagon release. DREAM−/−islets also show elevated glucagon secretion in low glucose compared with controls. These results demonstrate that PDN transcription is regulated by DREAM in a calcium-dependent manner and suggest a role for dynorphin regulation of α-cell glucagon secretion. The data provide a molecular basis for opiate stimulation of glucagon secretion first observed over 25 years ago.
Stimulation of the Human Frontal Eye Fields Modulates Sensitivity of Extrastriate Visual Cortex
Authors: Silvanto Juha , Lavie Nilli , Walsh Vincent
Published: April 2006

The precise role of frontal eye fields (FEF) in vision independent of their role in eye movements remains a matter of debate. One proposal is that the FEF exert top-down influences on the extrastriate visual cortex prior to eye movement preparation. Here we establish, by use of transcranial magnetic stimulation (TMS), that activity in the human FEFs has a direct effect on the sensitivity of extrastriate visual area MT/V5, and that the spatial organization of this top-down effect is lateralized in the human brain. We show that phosphene threshold—the TMS intensity required to elicit a visual perception—for MT/V5 stimulation changes as a function of the delay between the application of TMS over FEF and MT/V5. The effects were specific to the location and time of stimulation. Stimulation of FEF 20–40 ms prior to stimulation of MT/V5 decreased the intensity of MT/V5 stimulation required to elicit phosphenes: TMS of the right FEF changed the sensitivity of left and right MT/V5 whereas TMS of the left FEF changed the sensitivity only of the left MT/V5. Thus, the sensitivity of human extrastriate cortex is modulated by activity in the FEF.
The Lived Experience of Adult Survivors of Childhood Cancer
Authors: Prouty Diana , Ward-Smith Peggy , Hutto C. J.
Published: April 2006

Little is known about the long-term impact of surviving childhood cancer. Most children diagnosed with cancer now survive into adulthood due to advances in medical treatment. Although the number of survivors of childhood cancer has increased, a review of the literature revealed a paucity of studies that explores survivorship of childhood cancer from the perspective of the adult survivor. The purpose of this phenomenological study was to examine the lived experience of 12 adults who survived childhood cancer. This research methodology allows the meaning or essences of experiences that occurred to be uncovered. Four themes emerged from these data: (1) ongoing consequences for having had cancer, (2) living with uncertainty, (3) the cancer experience is embodied into one's present sense of self, and (4) support is valued. The results of this study demonstrate that a childhood cancer experience affects the life of each survivor, which results in specific health care needs. This knowledge is important as the number of survivors increases. Knowledge of their concerns is imperative prior to providing appropriate health care.
The transformation of spinal curvature into spinal deformity: pathological processes and implications for treatment
Authors: Hawes Martha C , O'Brien Joseph P
Published: April 2006

Background

This review summarizes what is known about the pathological processes (e.g. structural and functional changes), by which spinal curvatures develop and evolve into spinal deformities.

Methods

Comprehensive review of articles (English language only) published on 'scoliosis,' whose content yielded data on the pathological changes associated with spinal curvatures. Medline, Science Citation Index and other searches yielded > 10,000 titles each of which was surveyed for content related to 'pathology' and related terms such as 'etiology,' 'inheritance,' 'pathomechanism,' 'signs and symptoms.' Additional resources included all books published on 'scoliosis' and available through the Arizona Health Sciences Library, Interlibrary Loan, or through direct contact with the authors or publishers.

Results

A lateral curvature of the spine–'scoliosis'–can develop in association with postural imbalance due to genetic defects and injury as well as pain and scarring from trauma or surgery. Irrespective of the factor that triggers its appearance, a sustained postural imbalance can result, over time, in establishment of a state of continuous asymmetric loading relative to the spinal axis. Recent studies support the longstanding hypothesis that spinal deformity results directly from such postural imbalance, irrespective of the primary trigger, because the dynamics of growth within vertebrae are altered by continuous asymmetric mechanical loading. These data suggest that, as long as growth potential remains, evolution of a spinal curvature into a spinal deformity can be prevented by reversing the state of continuous asymmetric loading.

Conclusion

Spinal curvatures can routinely be diagnosed in early stages, before pathological deformity of the vertebral elements is induced in response to asymmetric loading. Current clinical approaches involve 'watching and waiting' while mild reversible spinal curvatures develop into spinal deformities with potential to cause symptoms throughout life. Research to define patient-specific mechanics of spinal loading may allow quantification of a critical threshold at which curvature establishment and progression become inevitable, and thereby yield strategies to prevent development of spinal deformity.

Even within the normal spine there is considerable flexibility with the possibility of producing many types of curves that can be altered during the course of normal movements. To create these curves during normal movement simply requires an imbalance of forces along the spine and, extending this concept a little further, a scoliotic curve is produced simply by a small but sustained imbalance of forces along the spine. In fact I would argue that no matter what you believe to be the cause of AIS, ultimately the problem can be reduced to the production of an imbalance of forces along the spine [1].
Direct Effect of Progestogen on Gene Expression in the Testis during Gonadotropin Withdrawal and Early Suppression of Spermatogenesis
Authors: Walton Melanie J. , Bayne Rosemary A. L. , Wallace Ian , Baird David T. , Anderson Richard A.
Published: April 2006

Context: Testicular production of steroids and gametes is under gonadotropin support, but there is little information as to the molecular mechanisms by which these are regulated in the human. The testicular response to gonadotropin withdrawal is important for the development of effective contraceptive methods.

Objective: Our objective was investigation of expression of genes in the normal human testis reflecting steroidogenesis, Sertoli cell function, and spermatogenesis after short-term gonadotropin withdrawal and the effects of activating testicular progesterone receptors.

Design and Setting: We conducted a randomized controlled trial at a research institute.

Patients: Thirty healthy men participated.

Interventions: Subjects were randomized to no treatment or gonadotropin suppression by GnRH antagonist (cetrorelix) with testosterone (CT group) or with additional administration of the gestogen desogestrel (CTD group) for 4 wk before testicular biopsy. Gene expression was quantified by RT-PCR.

Results: Both treatment groups showed similar suppression of gonadotropins and sperm production and markedly reduced expression of steroidogenic enzymes. Addition of progestogen in the CTD group resulted in reduced expression of 5α-reductase type 1 compared with both controls and the CT group. Inhibin-α and the spermatocyte marker acrosin-binding protein were significantly lower in the CTD but not CT groups, compared with controls, but did not differ between treated groups. Men who showed greater falls in sperm production also showed reduced expression of these three genes but not of the spermatid marker protamine 1.

Conclusions: These data provide evidence for direct progestogenic effects on the testis and highlight steroid 5α-reduction and disruption of spermiation as important components of the testicular response to gonadotropin withdrawal.
Self-sufficient Electron Injection from NADH to the Active Center of Flavin-Pendant Myoglobin
Authors: Hamachi Itaru , Nomoto Kana , Tanaka Shigeaki , Tajiri Yusuke , Shinkai Seiji
Published: April 2006

A riboflavin-appended myoglobin was successfully synthesized by the reconstitution of a chemically modified heme with apomyoglobin. Electron transfer from NADH to the heme active site was remarkably accelerated through a pendent riboflavin in the semi-artificial myoglobin.
Epoxidation of Olefins by Water Oxygen Catalyzed by Platinum Blue Complexes
Authors: Matsumoto Kazuko , Mizuno Kazuhiro , Abe Takeya , Kinoshita Jun , Shimura Hideo
Published: April 2006

The first olefin epoxidation by water oxygen is reported. The reaction is catalyzed by platinum blue complexes and is the first example that water oxygen atom is introduced into epoxides in catalytic or stoichiometric reaction.
Piperacillin/Tazobactam–Induced Paresthesiae
Authors: Lambourne Jonathan , Kitchen Joanne , Hughes Claudine , Merry Concepta
Published: April 2006

Objective:

To describe a case of a delayed-type hypersensitivity (DTH) reaction to piperacillin/tazobactam in which painful paresthesiae were a predominant feature.

Case Summary:

A 27-year-old man with a history of intravenous drug abuse was admitted for treatment of a pulmonary parenchymal abscess in the setting of lower-limb deep-venous thrombosis and methicillin-sensitive Staphylococcus aureus bacteremia. He was treated with intravenous piperacillin/tazobactam 4.5 g 3 times daily; however, after 2 weeks of therapy, he developed symptoms (eg, fever, chills) and laboratory abnormalities (eg, white blood cell count 2.1 × 103/mm3, erythrocyte sedimentation rate 63 mm/h) suggestive of a DTH reaction. This was accompanied by infusion-related painful paresthesiae. The symptoms and laboratory abnormalities resolved within 48 hours of treatment being switched to flucloxacillin.

Discussion:

Due to the close temporal association and the absence of any other obvious explanation, we believe these paresthesiae represent an additional feature of the DTH reaction to piperacillin/tazobactam in this patient. Use of the Naranjo probability scale indicated a probable relationship between the paresthesiae and administration of piperacillin/tazobactam.

Conclusions:

To our knowledge, as of March 24, 2006, this is the first case in which a DTH reaction to piperacillin/tazobactam manifesting as fever, neutropenia, and thrombocytopenia has been associated with paresthesiae.
Activated Microglia Contribute to the Maintenance of Chronic Pain after Spinal Cord Injury
Authors: Hains Bryan C. , Waxman Stephen G.
Published: April 2006

Traumatic spinal cord injury (SCI) results not only in motor impairment but also in chronic central pain, which can be refractory to conventional treatment approaches. It has been shown recently that in models of peripheral nerve injury, spinal cord microglia can become activated and contribute to development of pain. Considering their role in pain after peripheral injury, and because microglia are known to become activated after SCI, we tested the hypothesis that activated microglia contribute to chronic pain after SCI. In this study, adult male Sprague Dawley rats underwent T9 spinal cord contusion injury. Four weeks after injury, when lumbar dorsal horn multireceptive neurons became hyperresponsive and when behavioral nociceptive thresholds were decreased to both mechanical and thermal stimuli, intrathecal infusions of the microglial inhibitor minocycline were initiated. Electrophysiological experiments showed that minocycline rapidly attenuated hyperresponsiveness of lumbar dorsal horn neurons. Behavioral data showed that minocycline restored nociceptive thresholds, at which time spinal microglial cells assumed a quiescent morphological phenotype. Levels of phosphorylated-p38 were decreased in SCI animals receiving minocycline. Cessation of delivery of minocycline resulted in an immediate return of pain-related phenomena. These results suggest an important role for activated microglia in the maintenance of chronic central below-level pain after SCI and support the newly emerging role of non-neuronal immune cells as a contributing factor in post-SCI pain.
Rapid, Activity-Dependent Plasticity in Timing Precision in Neonatal Barrel Cortex
Authors: Daw Michael I. , Bannister Neil V. , Isaac John T. R.
Published: April 2006

Developing neuronal networks acquire the ability to precisely time events, a key feature required for information processing. In the barrel cortex, encoding of information requires a high-precision temporal code with a resolution of ∼5 ms; however, it is not known what process drives the maturation in timing precision. Here, we report that long-term potentiation (LTP) at thalamocortical synapses in the neonatal layer IV barrel cortex produces a dramatic improvement in the timing of neuronal output and synaptic input. LTP strongly reduces the latency and variability of synaptically evoked action potentials, improving the fidelity of timing to within that predicted to be required for adult sensory processing. Such changes in timing also occur during development in the neonate. LTP also reduces the summation of EPSPs shortening the window for coincidence detection for synaptic input. In contrast to these reliable effects, LTP produced only a modest and variable change in synaptic efficacy. Thus, our findings suggest that the primary role of this form of neonatal LTP is for the acquisition of timing precision and the refinement of coincidence detection, rather than an increase in synaptic strength. Therefore, neonatal thalamocortical LTP may be a critical prerequisite for the maturation of information processing in the barrel cortex.
Barrel Map Development Relies on Protein Kinase A Regulatory Subunit IIβ-Mediated cAMP Signaling
Authors: Inan Melis , Lu Hui-Chen , Albright Michael J. , She Wei-Chi , Crair Michael C.
Published: April 2006

The cellular and molecular mechanisms mediating the activity-dependent development of brain circuitry are still incompletely understood. Here, we examine the role of cAMP-dependent protein kinase [protein kinase A (PKA)] signaling in cortical development and plasticity, focusing on its role in thalamocortical synapse and barrel map development. We provide direct evidence that PKA activity mediates barrel map formation using knock-out mice that lack type IIβ regulatory subunits of PKA (PKARIIβ). We show that PKARIIβ-mediated PKA function is required for proper dendritogenesis and the organization of cortical layer IV neurons into barrels, but not for the development and plasticity of thalamocortical afferent clustering into a barrel pattern. We localize PKARIIβ function to postsynaptic processes in barrel cortex and show that postsynaptic PKA targets, but not presynaptic PKA targets, have decreased phosphorylation inpkar2bknock-out (PKARIIβ−/−) mice. We also show that long-term potentiation at TC synapses and the associated developmental increase in AMPA receptor function at these synapses, which normally occurs as barrels form, is absent in PKARIIβ−/−mice. Together, these experiments support an activity-dependent model for barrel map development in which the selective addition and elimination of thalamocortical synapses based on Hebbian mechanisms for synapse formation is mediated by a cAMP/PKA-dependent pathway that relies on PKARIIβ function.
Alterações metabólicas da síndrome lipodistrófica do HIV
Authors: Valente Angélica M.M. , Reis André F. , Machado Daisy M. , Succi Regina C.M. , Chacra Antonio R.
Published: April 2006

A introdução da highly active antiretroviral therapy (HAART) - terapia anti-retroviral fortemente ativa - vem reduzindo a morbidade e a mortalidade em pacientes infectados com o vírus da imunodeficiência humana (HIV). Entretanto, tratamentos prolongados, com combinações de drogas, são de difícil manutenção devido à má aderência e aos efeitos tóxicos. O tratamento com agentes anti-retrovirais, especialmente os inibidores da protease, fez surgir uma síndrome caracterizada por redistribuição anormal da gordura corporal, alterações no metabolismo glicêmico, resistência insulínica e dislipidemia, chamada de síndrome lipodistrófica do HIV (SLHIV). Atualmente não existe nenhum consenso para prevenção ou tratamento da síndrome, cuja causa permanece desconhecida. Esta revisão enfatiza os achados clínicos e dados da literatura a respeito da SLHIV, pois um melhor entendimento desta síndrome por infectologistas, cardiologistas e endocrinologistas é essencial para o manejo da doença.
Nota sobre a ocorrência de leishmaniose tegumentar americana na Serra da Cantareira, São Paulo, SP, Brasil
Authors: Proença Nelson Guimarães , Muller Helena
Published: April 2006

Relata-se a ocorrência de um pequeno surto de leishmaniose tegumentar americana, na Serra da Cantareira, São Paulo, SP, Brasil. Foram feitas considerações sobre a persistência de nichos de leishmaniose no Estado de São Paulo.
Subtipos do antígeno Austrália (HBsAg) em doentes de hanseníase de São Paulo, Brasil
Authors: Ottati Sandra , Candeias J. A. N.
Published: April 2006

Foram examinados 135 soros de pacientes com hanseníase para identificação dos subtipos ad e ay de HB sAg, tendo-se encontrado somente 3 casos positivos para o antígeno Austrália, todos eles do subtipo ad (2,2%).
Ocorrência de infecção natural de Fasciola hepatica Linnaeus, 1758 em Lymnaea columella Say, 1817 no Vale do Paraíba, SP, Brasil
Authors: Ueta Marlene Tiduko
Published: April 2006

Foram registradas em Piquete, no vale do rio Paraíba do Sul (SP), Brasil, taxas de 1,22% e 0,14% de infecção natural em Lymnaea columella, por Fasciola hepatica. Em um único exemplar de Lymnaea columella dentre os 1.052 examinados, foram observadas rédias com xifidiocercárias, rédias com cercárias de Fasciola hepatica e metacercárias de Echinostomatidae.
Molecular identification of Candida dubliniensis isolated from oral lesions of HIV-positive and HIV-negative patients in São Paulo, Brazil
Authors: Chavasco Jorge Kleber , Paula Claudete Rodrigues , Hirata Mario Hiroyuki , Aleva Natanael Atilas , Melo Carlos Eduardo de , Gambale Walderez , Ruiz Luciana da Silva , Franco Marília Caixeta
Published: April 2006

Candida dubliniensis is a new, recently described species of yeast. This emerging oral pathogen shares many phenotypic and biochemical characteristics with C. albicans, making it hard to differentiate between them, although they are genotypically distinct. In this study, PCR (Polymerase Chain Reaction) was used to investigate the presence of C. dubliniensis in samples in a culture collection, which had been isolated from HIV-positive and HIV-negative patients with oral erythematous candidiasis. From a total of 37 samples previously identified as C. albicans by the classical method, two samples of C. dubliniensis (5.4%) were found through the use of PCR. This study underscores the presence of C. dubliniensis, whose geographical and epidemiological distribution should be more fully investigated.
Simuliidae (Diptera:Culicomorpha) no Brasil XI - Shelleyellum gênero novo
Authors: Py-Daniel Victor , Pessoa Felipe Arley Costa
Published: April 2006

É caracterizado um novo gênero neotropical de simulídeo, com base nas espécies previamente incluídas no "Grupo Siolii", do gênero Psaroniocompsa. Chaves de identificação para imaturos são apresentadas. O gênero Shelleyellum fica constituído pelas espécies: S. damascenoi (Py-Daniel,1988), S. guaporense (Py-Daniel, 1989), S. lourencoi (Py-Daniel, 1988), S. siolli (Py-Daniel, 1988), S. tergospinosum (Hamada, 2000). O gênero é caracterizado, principalmente, pela de carena longitudinal nos distímeros dos machos e a presença de tubérculos tegumentares nas larvas.
Tráfego de máquinas agrícolas e alterações de bioporos em área sob pomar de laranja
Authors: Lima Herdjania Veras de , Lima Cláudia Liane Rodrigues de , Leão Tairone Paiva , Cooper Miguel , Silva Alvaro Pires da , Romero Ricardo Espíndola
Published: April 2006

O estudo micromorfológico permite observar detalhadamente todas as modificações causadas na estrutura e no espaço poroso do solo, impostas pelo cultivo e pelo tráfego de máquinas agrícolas. Este trabalho testou a hipótese de que a compactação causada pelo tráfego de máquinas influi, diferencialmente, na forma e na distribuição das classes de poros, os quais podem ser utilizados como indicadores da qualidade do solo. O objetivo deste trabalho foi avaliar e quantificar, por meio de estudos micromorfológicos, as modificações na porosidade oriunda da atividade biológica (bioporos) em um Latossolo Vermelho-Amarelo sob pomar de laranja submetido ao tráfego de máquinas. Amostras indeformadas foram coletadas na superfície (0-12 cm) de uma área sob pomar de laranja, abrangendo as posições: entrerodado (ER), rodado (R) e projeção da copa (PC), utilizado, como testemunha, um perfil sob mata. Os resultados mostraram que o aumento na diversidade de poros está diretamente relacionado com os processos de degradação da estrutura do solo e que o estudo da ocorrência das classes de poros mostrou-se mais eficiente na identificação da compactação do solo em estádios iniciais que os dados de densidade do solo.
O resfriamento rápido e a rápida instalação da atmosfera controlada como substitutos do 1-MCP no armazenamento de maçãs 'Gala'
Authors: Brackmann Auri , Giehl Ricardo Fabiano Hettwer , Freitas Sérgio Tonetto de , Mello Anderson Machado de , Antes Rose Beatriz
Published: April 2006

O objetivo deste trabalho foi avaliar o efeito da aplicação do 1-metilciclopropeno (1-MCP) associada a diferentes formas de resfriamento e de instalação da atmosfera controlada (AC) sobre a qualidade da maçã 'Gala'. No primeiro experimento, os tratamentos consistiram da aplicação ou não de 1-MCP no início do armazenamento refrigerado com dois períodos necessários para o resfriamento dos frutos até a temperatura de armazenamento (0,5°C): sete dias (lento) e três dias (rápido). No segundo experimento, avaliou-se o efeito da aplicação de 1-MCP associada com a instalação lenta (sete dias) ou rápida (até três dias) da AC (1,2kPa O2 + 2,5kPa CO2). A dose de 1-MCP utilizada foi de 660nL L-1, aplicada no início do armazenamento, durante 24 horas, a 0,5°C. No primeiro ensaio, o resfriamento dos frutos em três dias, em comparação com o resfriamento em sete dias, permitiu melhor manutenção dos atributos qualitativos dos frutos após seis meses de armazenamento refrigerado a 0,5°C e mais sete dias a 20°C, independentemente da aplicação de 1-MCP. No segundo experimento, observou-se que a instalação rápida da AC proporcionou resultados semelhantes à aplicação de 1-MCP, durante a instalação lenta, na manutenção da qualidade dos frutos, após oito meses de armazenamento em AC, a 0,5°C, e mais sete dias a 20°C. Esses resultados sugerem que o resfriamento rápido ou a rápida instalação da AC podem substituir a aplicação de 1-MCP em maçãs 'Gala'.
Estaquia do porta-enxerto de videira '43-43' (V. vinifera x V. rotundifolia) resistente à Eurhizococchus brasiliensis
Authors: Botelho Renato Vasconcelos , Maia Aline José , Pires Erasmo José Paioli , Terra Maurilo Monteiro , Schuck Enio
Published: April 2006

O experimento foi realizado com o objetivo de avaliar a propagação vegetativa por estaquia do porta-enxerto de videira '43-43'. Ramos herbáceos coletados em janeiro e semilenhosos em março que foram separados em dois lotes: um de estacas retiradas do ápice e outro da base dos ramos. As estacas foram então imersas por 10 segundos em soluções contendo diferentes concentrações de ácido indolilbutírico (0; 1.000; 1.500; 2.000; 2.500 ou 3.000 mg.L-1), totalizando 12 tratamentos para cada época de enraizamento. Posteriormente, as estacas foram plantadas em vasos de polipropileno com areia e mantidas em casa de vegetação sob sistema de nebulização. Sessenta dias após o plantio das estacas, para cada época, foram avaliadas as seguintes variáveis: porcentagem de estacas enraizadas, comprimento médio de raízes, massa fresca de raízes e porcentagem de estacas brotadas. Estacas herbáceas e semilenhosas apresentaram alta porcentagem de enraizamento (66,0% e 68,0%, respectivamente) mesmo quando não tratadas com o fitorregulador. Estacas apicais apresentaram maior comprimento e massa fresca de raízes. A aplicação de AIB reduziu a porcentagem de enraizamento e de brotação de estacas herbáceas e semilenhosas. Estacas semilenhosas, quando tratadas com o AIB a 1.000 mgL-1, apresentaram maior comprimento e massa fresca de raízes.
Indução de embriogênese somática em cupuaçu (Theobroma grandiflorum Schum.)
Authors: Ferreira Maria das Graças Rodrigues , Carvalho Carlos Henrique Siqueira de , Carneiro Andréia de Almeida , Damião Filho Carlos Ferreira
Published: April 2006

Folhas jovens de cupuaçu (Theobroma grandiflorum Schum.) foram empregadas para indução de embriogênese somática, as quais foram cultivadas inicialmente em meio MS suplementado com 6,0 mg/L BAP e 0,5 mg/L AIA (meio de estabelecimento), seguindo-se o cultivo em meio MS suplementado com 2,20 mg/L TDZ (meio de indução). A região da nervura mostrou intumescimento três dias após inoculação no meio de estabelecimento, o qual foi seguido pela formação de cachos de calos. As massas calosas foram transferidas para o meio de indução, e as estruturas com características pró-embriogênicas puderam ser observadas após uma semana. Estudos de microscopia eletrônica de varredura revelaram estruturas com características de embriões somáticos no meio com TDZ.
Trombose venosa profunda e suspeita de tromboembolismo pulmonar: avaliação simultânea por meio de angiotomografia pulmonar e venotomografia combinadas
Authors: Gomes Laura de Moraes , Marchiori Edson , Rodrigues Rosana Souza
Published: April 2006

OBJETIVO: Avaliar a ocorrência e a correlação de tromboembolismo pulmonar (TEP) e trombose venosa profunda (TVP) por meio de um protocolo único de angiotomografia computadorizada. MATERIAIS E MÉTODOS: Estudo prospectivo realizado de julho de 2003 a junho de 2004 no Hospital Copa D'Or, Rio de Janeiro, RJ. Foram analisadas 116 angiotomografias de pacientes com suspeita clínica de TEP. Após o estudo do tórax, com um intervalo de três minutos e sem injeção adicional de contraste, foram obtidos cortes do diafragma até os joelhos, a fim de pesquisar TVP. RESULTADOS: De 116 pacientes, 23 (19,8%) cursaram com TEP, 24 com TVP (20,7%), 15 (12,9%) apresentaram tanto TEP quanto TVP e 9 (7,8%) apresentaram TVP na ausência de TEP. Dos 23 casos positivos de TEP, 15 apresentaram concomitantemente TVP (65,2%), enquanto em 8 (34,8%) foi visto apenas TEP. Dos 24 casos positivos de TVP, 15 (62,5%) apresentaram TEP associado, enquanto em 9 (37,5%) foi encontrada TVP isolada. CONCLUSÃO: Os resultados demonstraram a forte relação entre TEP e TVP, a importância de pesquisar TVP nos casos com suspeita de TEP e a utilidade do uso combinado da angiotomografia de tórax e da venotomografia como alternativa de único exame de investigação de TEP e TVP simultaneamente.
Avaliação radiográfica da idade óssea em crianças infectadas pelo HIV por via vertical
Authors: Oliveira Helena Willhelm de , Veeck Elaine Bauer , Souza Paulo Henrique Couto , Fernandes Ângela
Published: April 2006

OBJETIVO: O presente trabalho teve por objetivo avaliar o desenvolvimento de crianças infectadas pelo vírus da imunodeficiência adquirida (HIV) por contaminação vertical, comparando-se dois métodos determinantes da idade óssea. MATERIAIS E MÉTODOS: Analisou-se uma amostra de 100 crianças, com idades variando de 4 anos e 2 meses a 11 anos e 9 meses, que realizaram radiografias de mão e punho tecnicamente padronizadas e que, posteriormente, foram analisadas segundo os critérios dos métodos de Greulich e Pyle (1959) e de Eklöf e Ringertz (1967). RESULTADOS: Os resultados obtidos mostraram diferenças estatísticas entre os métodos de análise radiográfica do desenvolvimento esquelético utilizados, com destaque para a maior sensibilidade em relação ao método de Eklöf e Ringertz (p < 0,05). O grupo feminino apresentou diferenças estatisticamente significantes entre os casos controle e HIV+ (sete casos) quando avaliados por este método (p < 0,05). CONCLUSÃO: Constatou-se, com a presente pesquisa, que houve a influência do HIV sobre o desenvolvimento esquelético neste grupo de pacientes.
Infecção pulmonar tripla em paciente gravemente imunocomprometido por AIDS: relato de caso
Authors: Faucz Rafael Artigas , Quadros Marianne Siquara de , Andrade Celso Alessandro , Troncoso Flávio Trentin , Ribeiro Filho Nelson , Furtado Juvencio Duailibe , Souza Ricardo Pires de
Published: April 2006

Os autores relatam um caso de paciente do sexo masculino, 38 anos de idade, motorista, soropositivo para HIV há oito anos, sem acompanhamento, com quadro de tosse produtiva com secreção acinzentada e episódios intermitentes de dispnéia há 15 dias. Informava dois episódios pregressos de tuberculose pulmonar (1983 e 2001) tratados. A radiografia de tórax evidenciou áreas de hipotransparência nodular e broncogramas aéreos bilateralmente. A tomografia computadorizada de tórax evidenciou vários achados inespecíficos, dentre eles áreas esparsas de consolidação, cavitação, bronquiectasia, opacidade em vidro fosco, espessamento intersticial e broncogramas aéreos. A lavagem broncoalveolar evidenciou numerosas hifas com raros septos bifurcados sugestivos de Aspergillus sp. e a cultura foi positiva para Nocardia sp. e Mycobacterium tuberculosis. Foi instituída terapia com anfotericina B, sulfametoxazol-trimetoprim e anti-retrovirais. Após 20 dias, recebeu alta sem queixas pulmonares. Decorridos 15 dias, retornou com diarréia, febre, disfagia e emagrecimento importante. Foi a óbito após cinco dias, por sepse estafilocócica.
Afinidades eletivas e pensamento econômico: 1870-1914
Authors: Paula João Antônio de
Published: April 2006

O artigo busca mostrar a aplicabilidade do conceito de "afinidades eletivas" para tratar das relações entre o pensamento econômico, a literatura e a filosofia. Em particular destaca-se o pensamento institucionalista, a escola histórica alemã e o pensamento neoclássico
Investigações fenomenológicas sobre a pintura
Authors: Escoubas Eliane
Published: April 2006

Tenta-se aqui elaborar uma fenomenologia do espaço pictural, com base nos textos de Heidegger, Merleau-Ponty e Henry Maldiney. As análises feitas foram confrontadas in fine com as de historiadores de arte, principalmente Wölfflin.
Consumo de água pela cultura do crisântemo cultivada em ambiente protegido
Authors: Pereira Joelma R. D. , Carvalho Jacinto de A. , Miguel Douglas S. , Santana Márcio J. de
Published: April 2006

Com o objetivo de determinar o consumo de água pela cultura do crisântemo, ao longo do seu ciclo de desenvolvimento, conduziu-se um experimento em ambiente protegido, na Universidade Federal de Lavras - MG, com as cultivares Kátia e Bi Time. O delineamento experimental foi o inteiramente casualizado, em esquema fatorial, com duas cultivares e duas freqüências de irrigação, com oito repetições, sendo o manejo da irrigação feito utilizando-se do método da pesagem. O consumo de água entre irrigações foi obtido pela pesagem dos vasos. Instalou-se na área experimental um tanque Classe A, para obter a evaporação e posterior correlação com o consumo hídrico das cultivares. Verificou-se que não houve diferença significativa do consumo quando as cultivares foram irrigadas uma e duas vezes ao dia. Observou-se que as cultivares possuem consumo diferenciado segundo seus estádios de desenvolvimento. O consumo médio de água, ao longo do ciclo, para a freqüência de irrigação de uma e duas vezes ao dia, da cultivar Kátia, foi de 118 e 108 mL dia-1, e da cultivar Bi Time, foi de 98 e 113 mL dia-1, respectivamente.
Estudo das alterações ultra-estruturais em pleura de ratos pós pleurodese por talco
Authors: Refosco Tiago J. , Dutra Isabela , Schneider Airton
Published: April 2006

OBJETIVO: O talco é considerado um agente efetivo de pleurodese freqüentemente utilizado no tratamento de derrame pleural maligno. Entretanto, questiona-se sua segurança em relação à carcinogênese. O objetivo deste trabalho é descrever as alterações ultra-estruturais encontradas nas pleuras de ratos submetidos à pleurodese com talco buscando esclarecer sua segurança em relação à carcinogênese. MÉTODO: Neste estudo randomizado foram utilizados seis ratos machos do tipo Wistar, pesando 250 g. Através de uma toracotomia mínima no quinto espaço intercostal esquerdo foi colocado lavado de talco em concentrações de 0,5mg (n=2) e 0,1 mg (n=2) de talco por grama de peso. Dois ratos foram apenas anestesiados e foi instilado solução fisiológica (NaCl 0,9%) intrapleural para configurar o grupo controle. Os ratos foram mortos após 45 dias. As alterações morfológicas e morfométricas ultra-estruturais foram analisadas através de microscopia eletrônica de transmissão. RESULTADOS: A análise ultra-estrutural das pleuras submetidas à talcagem demonstrou desorganização celular do tecido conjuntivo, evidenciando alterações nucleares, mitocondriais e espessamento da camada submesotelial. O grupo controle manteve a arquitetura celular preservada. CONCLUSÕES: Este estudo revelou alterações da estrutura celular da pleura exposta ao talco quando comparado ao grupo controle.