bluuebunny/crossref_metadata_2025 huggingface dataset:
Risk of contrast induced nephropathy in the critically ill: a prospective, case matched study
Authors: Cely Cynthia M , Schein Roland MH , Quartin Andrew A
Published: April 2012

Introduction

Computerized tomography is frequently employed in the critically ill, often using intravenous radiocontrast material. Many of these patients have clinical features that are considered risk factors for contrast induced nephropathy, but are simultaneously at risk for renal injury from other factors related to their acute illnesses. The attributable risk for renal dysfunction from radiocontrast exposure has not been well quantified in this population.

Methods

A prospective matched cohort study was conducted of patients scanned with or without radiocontrast enhancement while receiving intensive care in a Veterans Affairs Medical Center. Patients were matched for pre-scan measured creatinine clearance, diabetes, mechanical ventilation, and vasopressor use. Measured clearance was followed for three days after scanning. Evolution of nephropathy, as determined by change in measured clearance, was compared within matched pairs.

Results

Fifty-three pairs of patients satisfied matching criteria. Unmatched characteristics were similar among the pairs, including serum creatinine variability during the week preceding scanning (67 ± 85% among contrast recipients, 63 ± 62% among others) and clinical risk factors for renal failure. In 29 pairs, pre-scan measured clearances were less than 60 mL/minute/1.73 m2. Following scanning, measured clearance declined by at least 33% in 14 contrast and 19 non-contrast patients (95% confidence interval for contrast associated difference in nephropathy rates -27% to 9%), while a 50% reduction in clearance persisted three days after scanning in three contrast and nine non-contrast patients (95% confidence interval for difference in rates -25% to 2%).

Conclusions

Among established intensive care unit patients declines in glomerular filtration following contrast-enhanced scanning are common, but these changes are far more likely to be attributable to factors other than the contrast exposure itself. The upper bound for the incidence of contrast induced renal injury lasting even three days was 2% in the population studied.
Time-lapse acoustic, transport, and NMR measurements to characterize microstructural changes of carbonate rocks during injection of CO2-rich water
Authors: Grombacher Denys , Vanorio Tiziana , Ebert Yael
Published: April 2012

We investigated how changes induced in the microstructure of carbonate rocks by the injection of [Formula: see text]-rich water affect pore-network properties. In particular, we investigated from multiple perspectives the microstructural changes and types of porosity that alter the observable geophysical properties. We thereby refined our understanding of induced modification of the pore network. Our experimental protocol included a suite of time-lapse acoustic, transport, and nuclear magnetic resonance (NMR) measurements, along with scanning electron microscopy (SEM) and CT-scan images; these gave us complementary sensitivity to changes in different properties of the pore space. Induced porosity variations were smaller than in previous reported results because of chemomechanical compaction resulting from dissolution under pressure. No porosity enhancements larger than 0.8 pu were observed. Results indicated that dissolution occured primarily in the grain-coating cement and the microporosity of the micritic phase. Both caused the formation of cracklike pores around larger grains leading to a more compliant frame, causing both velocity reductions and an increased sensitivity of velocity to pressure. Chalky micritic facies exhibited velocity reductions of [Formula: see text], whereas micritic limestones, less prone to compaction and grain sliding, experienced smaller velocity reductions ([Formula: see text]). Because porosity enhancement was minimal, we hypothesized that the reductions were due to injection-induced reduction of grain-contact stiffness. Dissolution-induced compaction played an integral role also in the permeability response during injection. Compaction in pressure-sensitive chalky facies strongly counteracted the effects of dissolution, leading to negligible permeability and NMR response changes. In contrast, stiff micritic limestones with little dissolution-induced compaction exhibited larger permeability increases ([Formula: see text]). This work demonstrated the advantages of utilizing a suite of concurrent and independent measurements to build a more comprehensive interpretation of microstructure changes induced by injecting fluids that are in chemical disequilibrium with the host formation.
Ablation of Vimentin Results in Defective Steroidogenesis
Authors: Shen Wen-Jun , Zaidi Syed Kashif , Patel Shailja , Cortez Yuan , Ueno Masami , Azhar Rakia , Azhar Salman , Kraemer Fredric B.
Published: April 2012

In steroidogenic tissues, cholesterol must be transported to the inner mitochondrial membrane to be converted to pregnenolone as the first step of steroidogenesis. Whereas steroidogenic acute regulatory protein has been shown to be responsible for the transport of cholesterol from the outer to the inner mitochondrial membrane, the process of how cholesterol moves to mitochondria from the cytoplasm is not clearly defined. The involvement of the cytoskeleton has been suggested; however, no specific mechanism has been confirmed. In this paper, using genetic ablation of an intermediate filament protein in mice, we present data demonstrating a marked defect in adrenal and ovarian steroidogenesis in the absence of vimentin. Cosyntropin-stimulated corticosterone production is decreased 35 and 50% in male and female Vimentin null (Vim−/−) mice, respectively, whereas progesterone production is decreased 70% in female Vim−/− mice after pregnant mare's serum gonadotropin and human chorionic gonadotropin stimulation, but no abnormalities in human chorionic gonadotropin-stimulated testosterone production is observed in male Vim−/− mice. These defects in steroid production are also seen in isolated adrenal and granulosa cells in vitro. Further studies show a defect in the movement of cholesterol from the cytosol to mitochondria in Vim−/− cells. Because the mobilization of cholesterol from lipid droplets and its transport to mitochondria is a preferred pathway for the initiation of steroid production in the adrenal and ovary but not the testis and vimentin is a droplet-associated protein, our results suggest that vimentin is involved in the movement of cholesterol from its storage in lipid droplets to mitochondria for steroidogenesis.
Pattern formation at the ocean surface: Sargassum distribution and the role of the eddy field
Authors: Zhong Yisen , Bracco Annalisa , Villareal Tracy A.
Published: April 2012

Lay Abstract

Organisms that float at the ocean surface such as the macroalga Sargassum and the cyanobacterium Trichodesmium often accumulate in lines visible in satellite imagery. These lines have lateral scale separations of a few kilometers and cannot be explained by Langmuir circulation. Here we discuss the physical process responsible for the accumulation of floating materials in the ocean in the presence of mesoscale (tens of kilometers) and submesoscale (few kilometers) turbulence. Using high‐resolution simulations in both an idealized domain (a 3‐dimensional box where turbulence is excited by small‐scale winds and eddies form) and a realistic domain (western Gulf of Mexico, where extensive concentrations of floating Sargassum have been recorded in satellite images), we show that the distribution of tracers at the ocean surface departs rapidly from that observed a few meters below the surface. The strong divergence and convergence zones generated at the ocean surface by ageostrophic processes (i.e., processes for which an exact balance between the Coriolis force and the pressure gradient force is not attained) at scales between hundreds of meters and a few kilometers are responsible for the creation of lines where the floating material accumulates. Floating particles in the model simulations are expelled from the core of eddies and concentrate in small filaments. The resulting patterns are similar to the distribution of Sargassum seen in satellite images. Such organization may be common in many surface‐dwelling organisms and could play a role in enhancing biological interactions.
Vigorous SO42– influxviathe gills is balanced by enhanced SO42– excretion by the kidney in eels after seawater adaptation
Authors: Watanabe Taro , Takei Yoshio
Published: April 2012

Sulfate (SO42–) is maintained at ∼1 mmol–1 l–1 in teleost fishes that are exposed to media of varying SO42– concentrations. We first measured plasma SO42– concentration in euryhaline fishes that adapt to both SO42–-poor freshwater (<0.5 mmol l) and SO42–-enriched seawater (30 mmol l–1). Unlike Mozambique tilapia and chum salmon, Japanese eels maintained higher plasma SO42– concentration in freshwater (6.2±2.3 mmol l–1) than in seawater (0.7±0.1 mmol l–1). We then analyzed the whole-body SO42– budget using 35SO42–. 35SO42– influx in seawater-adapted eels occurred by 84.5% via body surfaces and 15.5% via digestive tracts. The SO42– influx was higher in seawater eels (1.55 μmol kg–1 h–1) than in freshwater eels (0.09 μmol kg–1 min–1), but it was facilitated in freshwater eels when the difference in SO42– concentrations between plasma and environment was taken into account (freshwater eels, 6.2 vs 0.3 mmol l–1; seawater eels, 0.7 vs 30 mmol l–1). One hour after injection of 35SO42– into the blood of seawater eels, the kidney excreted ∼97% of the ionized form, whereas the radioactivity increased gradually in the medium and the rectal fluid more than 3 h after injection. As the radioactivity was poorly adsorbed by anion-exchange resin, 35SO42– in the blood may be incorporated into cells and excreted by the intestine, gills and skin, probably as mucus. These results show that freshwater eels take up SO42– actively from the environment, but seawater eels cope with the obligatory influx of SO42– through the gills by excreting excess SO42–via the kidney and in mucus.
Oesophageal chemoreceptors of blue crabs,Callinectes sapidus, sense chemical deterrents and can block ingestion of food
Authors: Aggio Juan F. , Tieu Ryan , Wei Amy , Derby Charles D.
Published: April 2012

Decapod crustaceans such as blue crabs possess a variety of chemoreceptors that control different stages of the feeding process. All these chemoreceptors are putative targets for feeding deterrents that cause animals to avoid or reject otherwise palatable food. As a first step towards characterizing the chemoreceptors that mediate the effect of deterrents, we used a behavioral approach to investigate their precise location. Data presented here demonstrate that chemoreceptors located on the antennules, pereiopods and mouthparts do not mediate the food-rejection effects of a variety of deterrents, both natural and artificial to crabs. Crabs always searched for deterrent-laced food and took it to their oral region. The deterrent effect was manifested as either rejection or extensive manipulation, but in both cases crabs bit the food. The biting behavior is relevant because the introduction of food into the oral cavity ensured that the deterrents gained access to the oesophageal taste receptors, and so we conclude that they are the ones mediating rejection. Additional support comes from the fact that a variety of deterrent compounds evoked oesophageal dilatation, which is mediated by oesophageal receptors and has been linked to food rejection. Further, there is a positive correlation between a compound’s ability to elicit rejection and its ability to evoke oesophageal dilatation. The fact that deterrents do not act at a distance is in accordance with the limited solubility of most known feeding deterrents, and likely influences predator–prey interactions and their outcome: prey organisms will be attacked and bitten before deterrents become relevant.
Constraints-based stoichiometric analysis of hypoxic stress on steroidogenesis in fathead minnows, Pimephales promelas
Authors: Hala David , Petersen Lene H. , Martinovic Dalma , Huggett Duane B.
Published: April 2012

In this study, an in silico genome-scale metabolic model of steroidogenesis was used to investigate the effects of hypoxic stress on steroid hormone productions in fish. Adult female fathead minnows (Pimephales promelas) were exposed to hypoxia for 7 days with fish sub-sampled on days 1, 3 and 7 of exposure. At each time point, selected steroid enzyme gene expressions and steroid hormone productions were quantified in ovaries. Fold changes in steroid enzyme gene expressions were used to qualitatively scale transcript enzyme reaction constraints (akin to the range of an enzyme’s catalytic activity) in the in silico model. Subsequently, in silico predicted steroid hormone productions were qualitatively compared with experimental results. Key findings were as follows. (1) In silico gene deletion analysis identified highly conserved ‘essential’ genes required for steroid hormone productions. These agreed well (75%) with literature-published genes downregulated in vertebrates (fish and mammal) exposed to hypoxia. (2) Quantification of steroid hormones produced ex vivo from ovaries showed a significant reduction for 17β-estradiol and 17α,20β-dihydroxypregnenone production after 24 h (day 1) of exposure. This lowered 17β-estradiol production was concomitant with downregulation of cyp19a1a gene expression in ovaries. In silico predictions showed agreement with experimentation by predicting effects on estrogen (17β-estradiol and estrone) production. (3) Stochastic sampling of in silico reactions indicated that cholesterol uptake and catalysis to pregnenolone along with estrogen methyltransferase and glucuronidation reactions were also impacted by hypoxia. Taken together, this in silico analysis introduces a powerful model for pathway analysis that can lend insights on the effects of various stressor scenarios on metabolic functions.
Within-lifetime trade-offs but evolutionary freedom for hormonal and immunological traits: evidence from mice bred for high voluntary exercise
Authors: Downs Cynthia J. , Schutz Heidi , Meek Thomas H. , Dlugosz Elizabeth M. , Acosta Wendy , de Wolski Karen S. , Malisch Jessica L. , Hayes Jack P. , Garland Theodore
Published: April 2012

Chronic increases in circulating corticosterone (CORT) generally suppress immune function, but it is not known whether evolved increases necessarily have similar adverse effects. Moreover, the evolution of immune function might be constrained by the sharing of signaling molecules, such as CORT, across numerous physiological systems. Laboratory house mice (Mus domesticus Linnaeus) from four replicate lines selectively bred for high voluntary wheel running (HR lines) generally had baseline circulating CORT approximately twofold higher than in four non-selected control (C) lines. To test whether elevated baseline CORT suppresses the inflammatory response in HR mice, we injected females with lipopolysaccharide (LPS). All mice injected with LPS exhibited classic signs of an inflammatory response, including sickness behavior, loss of body mass, reduced locomotor activity (i.e. voluntary wheel running), enlarged spleens and livers, elevated hematocrit and elevated inflammatory cytokines. However, as compared with C mice, the inflammatory response was not suppressed in HR mice. Our results, and those of a previous study, suggest that selective breeding for high voluntary exercise has not altered immune function. They also suggest that the effects of evolved differences in baseline CORT levels may differ greatly from effects of environmental factors (often viewed as ‘stressors’) that alter baseline CORT during an individual’s lifetime. In particular, evolved increases in circulating levels of ‘stress hormones’ are not necessarily associated with detrimental suppression of the inflammatory response, presumably as a result of correlated evolution of other physiological systems (counter-measures). Our results have important implications for the interpretation of elevated stress hormones and of immune indicators in natural populations.
Redox biology of exercise: an integrative and comparative consideration of some overlooked issues
Authors: Nikolaidis Michalis G. , Kyparos Antonios , Spanou Chrysoula , Paschalis Vassilis , Theodorou Anastasios A. , Vrabas Ioannis S.
Published: April 2012

The central aim of this review is to address the highly multidisciplinary topic of redox biology as related to exercise using an integrative and comparative approach rather than focusing on blood, skeletal muscle or humans. An attempt is also made to re-define ‘oxidative stress’ as well as to introduce the term ‘alterations in redox homeostasis’ to describe changes in redox homeostasis indicating oxidative stress, reductive stress or both. The literature analysis shows that the effects of non-muscle-damaging exercise and muscle-damaging exercise on redox homeostasis are completely different. Non-muscle-damaging exercise induces alterations in redox homeostasis that last a few hours post exercise, whereas muscle-damaging exercise causes alterations in redox homeostasis that may persist for and/or appear several days post exercise. Both exhaustive maximal exercise lasting only 30 s and isometric exercise lasting 1–3 min (the latter activating in addition a small muscle mass) induce systemic oxidative stress. With the necessary modifications, exercise is capable of inducing redox homeostasis alterations in all fluids, cells, tissues and organs studied so far, irrespective of strains and species. More importantly, ‘exercise-induced oxidative stress’ is not an ‘oddity’ associated with a particular type of exercise, tissue or species. Rather, oxidative stress constitutes a ubiquitous fundamental biological response to the alteration of redox homeostasis imposed by exercise. The hormesis concept could provide an interpretative framework to reconcile differences that emerge among studies in the field of exercise redox biology. Integrative and comparative approaches can help determine the interactions of key redox responses at multiple levels of biological organization.
Tarantulas do not shoot silk from their legs: experimental evidence in four species of New World tarantulas
Authors: Pérez-Miles Fernando , Ortíz-Villatoro David
Published: April 2012

Theraphosid tarantulas, like all other spiders, secrete silk from spigots on the abdominal spinnerets. A few years ago, it was proposed that the large tarantula Aphonopelma seemanni could extrude silk from specialized spigots on the tarsi to help adhesion to vertical surfaces. This suggestion was later questioned because silk was not observed after the spinnerets had been sealed. Recently, experiments with the tarantula Grammostola rosea again suggested tarsal silk secretion. All observations of the supposed tarsal silk were made in spiders with functional spinnerets, thus contamination with silk coming from the spinnerets could not be excluded. Recent morphological arguments also questioned putative tarsal spigots and proposed that they are actually contact chemoreceptors. We here test the supposed tarsal silk secretion in Aphonopelma seemanni, Avicularia avicularia, Brachypelma vagans and Grammostola mollicoma using similar experimental conditions as the previous authors, but with sealed spinnerets. Our results clearly demonstrate that when spinnerets are sealed, tarantulas do not show any tarsal silk secretion. We reinterpret those putative tarsal spigots and discuss possible evolutionary implications of these findings.
Contractual and Organizational Structure with Reciprocal Agents
Authors: Englmaier Florian , Leider Stephen
Published: April 2012

We solve for the optimal contract when agents are reciprocal, demonstrating that generous compensation can substitute for performance-based pay. Our results suggest several factors that make firms more likely to use reciprocal incentives. Reciprocity is most powerful when output is a poor signal of effort and when the agent is highly reciprocal and/or productive. Similarly, reciprocal incentives are attractive when firm managers have strong incentive pay and discretion over employee compensation. While reciprocal incentives can be optimal even when identical firms compete, a reciprocity contract is most likely when one firm has a match-specific productivity advantage with the agent. (JEL D23, D86, J33, M12, M52)
How Long Should Women Persevere with IVF?
Authors: Simonstein Frida , Mashiach-Eizenberg Michal
Published: April 2012

The Israeli public health insurance system covers an (almost) unlimited number of IVF cycles. In a global context, this is a policy which is looked upon as a northern star. However, many women may continue IVF treatment when the probability of a successful pregnancy is ‘zero’. This paper argues that the implication of a policy of unlimited rounds of IVF from the perspective of the ‘culture of perseverance’ that develops in IVF clinics has not yet been fully assessed. A systematic long term assessment of the health and welfare of women after IVF in Israel - especially after prolonged treatment with IVF - is necessary. In a global context, an evidence-based policy on ART may improve both the allocation of resources and the duty of care, not only in Israel, but also in other countries.
Cannabinoid Stability in Authentic Oral Fluid after Controlled Cannabis Smoking
Authors: Lee Dayong , Milman Garry , Schwope David M , Barnes Allan J , Gorelick David A , Huestis Marilyn A
Published: April 2012

BACKGROUND

Defining cannabinoid stability in authentic oral fluid (OF) is critically important for result interpretation. There are few published OF stability data, and of those available, all employed fortified synthetic OF solutions or elution buffers; none included authentic OF following controlled cannabis smoking.

METHODS

An expectorated OF pool and a pool of OF collected with Quantisal™ devices were prepared for each of 10 participants. Δ9-Tetrahydrocannabinol (THC), 11-nor-9-carboxy-THC (THCCOOH), cannabidiol (CBD), and cannabinol (CBN) stability in each of 10 authentic expectorated and Quantisal-collected OF pools were determined after storage at 4 °C for 1 and 4 weeks and at −20 °C for 4 and 24 weeks. Results within ±20% of baseline concentrations analyzed within 24 h of collection were considered stable.

RESULTS

All Quantisal OF cannabinoid concentrations were stable for 1 week at 4 °C. After 4 weeks at 4 °C, as well as 4 and 24 weeks at −20 °C, THC was stable in 90%, 80%, and 80% and THCCOOH in 89%, 40%, and 50% of Quantisal samples, respectively. Cannabinoids in expectorated OF were less stable than in Quantisal samples when refrigerated or frozen. After 4 weeks at 4 and −20 °C, CBD and CBN were stable in 33%–100% of Quantisal and expectorated samples; by 24 weeks at −20 °C, CBD and CBN were stable in ≤44%.

CONCLUSIONS

Cannabinoid OF stability varied by analyte, collection method, and storage duration and temperature, and across participants. OF collection with a device containing an elution/stabilization buffer, sample storage at 4 °C, and analysis within 4 weeks is preferred to maximize result accuracy.
Microtubule Redistribution in Growth Cones Elicited by Focal Inactivation of Kinesin-5
Authors: Nadar Vidya C. , Lin Shen , Baas Peter W.
Published: April 2012

In order for growth cones to turn, microtubules from the central domain must preferentially invade the peripheral domain in the direction of the turn. Recent studies suggest that kinesin-5 (also called Eg5 or kif11) suppresses the invasion of microtubules into the peripheral domain on the side of the growth cone opposite the direction of turning. In theory, kinesin-5 could elicit these effects by acting on the microtubules within the peripheral domain itself, by acting on microtubules in the central domain, or in the transition zone between these two domains. In rat neurons expressing kinesin-5, we documented the presence of kinesin-5 in both domains of the growth cone and especially enriched in the transition zone. We then focally inactivated kinesin-5 in various regions of the growth cone, using micro-chromophore-assisted laser inactivation. We found that a greater invasion of microtubules into the peripheral domain occurred when kinesin-5 was inactivated specifically in the transition zone. However, there was no effect on microtubule invasion into the peripheral domain when kinesin-5 was inactivated in the peripheral domain itself or in the central domain. In other experiments, frog growth cones were observed to turn toward a gradient of a drug that inhibits kinesin-5, confirming that asymmetric inactivation of kinesin-5 can cause the growth cone to turn. Finally, expression of a phospho-mutant of kinesin-5 resulted in greater microtubule invasion throughout the peripheral domain and an inhibition of growth cone turning, implicating phosphorylation as a means by which kinesin-5 is regulated in the growth cone.
Microsaccades and Blinks Trigger Illusory Rotation in the “Rotating Snakes” Illusion
Authors: Otero-Millan Jorge , Macknik Stephen L. , Martinez-Conde Susana
Published: April 2012

Certain repetitive arrangements of luminance gradients elicit the perception of strong illusory motion. Among them, the “Rotating Snakes Illusion” has generated a large amount of interest in the visual neurosciences, as well as in the public. Prior evidence indicates that the Rotating Snakes illusion depends critically on eye movements, yet the specific eye movement types involved and their associated neural mechanisms remain controversial. According to recent reports, slow ocular drift—a nonsaccadic type of fixational eye movement—drives the illusion, whereas microsaccades produced during attempted fixation fail to do so. Here, we asked human subjects to indicate the presence or absence of rotation during the observation of the illusion while we simultaneously recorded their eye movements with high precision. We found a strong quantitative link between microsaccade and blink production and illusory rotation. These results suggest that transient oculomotor events such as microsaccades, saccades, and blinks, rather than continuous drift, act to trigger the illusory motion in the Rotating Snakes illusion.
Collections-Based Research at Berkeley’s Museum of Vertebrate Zoology
Authors: Sunderland Mary E.
Published: April 2012

Recognizing natural history collections as dynamic scientific tools that enable unique forms of comparative analysis, theorizing, and questioning offers a new perspective on the history of the life sciences in the twentieth century that emphasizes the important role that collections played in the transformation of biology. To build an understanding of “collections-based research,” this paper focuses on the career of Alden Holmes Miller, who led the Museum of Vertebrate Zoology at the University of California, Berkeley through significant institutional, disciplinary, and technological changes (1940–1965). This paper examines how Miller’s efforts as researcher, administrator, and teacher enabled him to foster collections-based research. Miller’s own research into speciation and reproductive physiology are examples of collectionsbased work, incorporating concepts, theories, practices, and tools from the laboratory, museum, and field.
Free State Slavery: Bound Indian Labor and Slave Trafficking in California's Sacramento Valley, 1850–1864
Authors: Magliari Michael F.
Published: April 2012

Although it outlawed chattel slavery, antebellum California permitted the virtual enslavement of Native Americans under the 1850 Act for the Government and Protection of Indians. Drawing data from a rare and valuable cache of Indian indenture records at the Colusa County courthouse and interpreting them through the lens of Henry Bailey's candid pioneer memoir, this article offers a detailed case study of bound Native American labor and Indian slave trafficking in Northern California's Sacramento Valley. While never comprising a majority of the state's rural work force, bound Indian laborers proved essential to California's rise as a major agricultural producer. Compensating for the dearth of white women and children in male-dominated Gold Rush society and providing a vital alternative source of labor in an expensive free wage market, captive Indian farm hands and domestic servants enabled pioneer farm operations and communities to flourish throughout the formative 1850s and 1860s.
Indigenous Borderlands: Livestock, Captivity, and Power in the Far West
Authors: Zappia Natale A.
Published: April 2012

In the eighteenth and nineteenth centuries, Spaniards, Mexicans, and Americans of the Far West forged dynamic economies based on livestock, furs, and agriculture. Simultaneously, though, Natives in the borderlands between New Mexico and California expanded their economic and military power even as Californios and Nuevo Mexicanos emerged as dominant ruling classes. Through the formation and expansion of an indigenous captive-and-livestock raiding economy, the “Interior World” challenged the power of newcomers in the Far West. Understanding this raiding economy provides an important look at colonial exchanges from the indigenous perspective within the context of interregional trading networks and borderlands.
Enhanced Chlorophyll A Purification and Dye Sensitized Solar Cell Performance
Authors: Magsi Komal , Lee Ping , Kang Yeona , Bhattacharya Soumya , Fortmann Charles M
Published: April 2012

Dye-sensitized solar cells (DSSC) may provide an economical alternative to the present p–n junction photovoltaic devices. Here the relation between chlorophyll purity and photovoltaic performance was examined. Also the commercial grade copper chlorophyll was examined. The performance under simulated sunlight and the quantum efficiency were measured. All samples had large short wavelength quantum efficiency however the high purity chlorophyll had larger quantum efficiency in the visible. The highest purity samples produced DSSC solar cells with the highest open circuit voltage and efficiency while the fill factor and the short circuit current were not strongly correlated with purity. The un-altered short circuit current suggests that chlorophyll attachment and charge transfer at the titanium oxide are not altered by impurities. However the results suggest that impurities (and/or copper in the commercial chlorophyll case) alter the photo-absorption and the electrolyte so as to either change the iodine chemical potential or decrease the diffusivity of iodine ions.
Thermodynamic study of lithium-ion battery materials
Authors: Yu Denis Y.W. , Reynier Yvan , Cardema Joanna Dodd , Ozawa Yasunori , Yazami Rachid
Published: April 2012

The ability to monitor the status of a battery during charge and discharge is important for predicting its performance and life. This is typically done by measuring the voltage and resistance across the terminals, or by external characterization methods such as X-ray diffraction and Raman spectroscopy. Thermodynamics measurements based on entropy and enthalpy provide another mean to “look inside” a battery, giving us more information to determine the state of health of the battery. In particular, entropy undergoes drastic changes at boundaries of phase transitions taking place in each electrode material at defined states of charge (lithium stoichiometry). Recent work on thermodynamics study on lithium ion battery materials is summarized in this paper.
Metal- Metal Oxide Electrode: A Promising Energy Storage Candidate for Supercapacitor Application
Authors: Jena Anirudha , Munichandraiah N. , Shivashankar S. A.
Published: April 2012

In the present study we have synthesized Ni/NiO nanocomposite was synthesized via microwave assisted rapid chemical route. The electrochemical properties of the composite was studied and found to be showing better performance in presence of metallic nickel in presence of its oxide.
Evaluation of inadequate anti-retroviral treatment in patients with HIV/AIDS
Authors: Fonseca Leonardo Carvalho da , Martins Francislene Juliana , Vieira Rita de Cássia Padula Alves , Pereira Rouzeli Maria Coelho , Ferreira Aline Siqueira , Raposo Nádia Rezende Barbosa
Published: April 2012

INTRODUCTION: Since the emergence of antiretroviral therapy, the survival of patients infected with human immunodeficiency virus has increased. Non-adherence to this therapy is directly related to treatment failure, which allows the emergence of resistant viral strains. METHODS: A retrospective descriptive study of the antiretroviral dispensing records of 229 patients from the Center for Health Care, University Hospital, Federal University of Juiz de Fora, Brazil, was conducted between January and December 2009. RESULTS: The study aimed to evaluate patient compliance and determine if there was an association between non-adherence and the therapy. Among these patients, 63.8% were men with an average age of 44.0 ± 9.9 years. The most used treatment was a combination of 2 nucleoside reverse transcriptase inhibitors with 1 non-nucleoside reverse transcriptase inhibitor (55.5%) or with 2 protease inhibitors (28.8%). It was found that patients taking lopinavir/ritonavir with zidovudine and lamivudine had a greater frequency of inadequate treatment than those taking atazanavir with zidovudine and lamivudine (85% and 83.3%, respectively). Moreover, when the combination of zidovudine/ lamivudine was used, the patients were less compliant (χ2 = 4.468, 1 degree of freedom, p = 0.035). CONCLUSIONS: The majority of patients failed to correctly adhere to their treatment; therefore, it is necessary to implement strategies that lead to improved compliance, thus ensuring therapeutic efficacy and increased patient survival.
Seroepidemiological monitoring in sentinel animals and vectors as part of arbovirus surveillance in the state of Mato Grosso do Sul, Brazil
Authors: Batista Paulo Mira , Andreotti Renato , Chiang Jannifer Oliveira , Ferreira Milene Silveira , Vasconcelos Pedro Fernando da Costa
Published: April 2012

INTRODUCTION: From February-September 2010, seroepidemiological surveys were conducted on non-human primates and transmitter vector capture was used to investigate the possible circulation of arboviruses in the municipalities of Bonito, Campo Grande, and Jardim, State of Mato Grosso do Sul, Brazil. METHODS: A total of 65 primates from the wild and captivity were used, and potential vectors were captured using Castro and dip nets. Serum samples were tested at the Instituto Evandro Chagas, State of Pará, using the hemagglutination inhibition test to detect total antibodies against 19 different arboviruses. Virus isolation was attempted from serum samples and arthropod suspensions using newborn mice and the C6/36 cell line clone. In addition, identification of the vector species was conducted. RESULTS: From the 19 serum samples from Campo Grande, 1 sample had a 1:20 titer for Flavivirus. From the 35 samples collected in Bonito, 17 samples had antibodies to arboviruses, 4 (11.4%) were positive for Alphavirus, and 5 (14.2%) were positive for Flavivirus. Monotypic reactions were observed for the Mayaro (n = 10) and Oropouche (n = 5) viruses, and 6 (17.1%) samples had titers for >1 virus. We captured 120 Culicidae individuals that were potential arbovirus transmitters in Jardim; however, all the samples were negative for the viruses. CONCLUSIONS: Mato Grosso do Sul has a variety of vertebrate hosts and transmission vectors, thereby providing ideal conditions for the emergence or reemergence of arboviruses, including some pathogenic to human beings.
Circulation of the rabies virus in non-hematophagous bats in the city of Rio de Janeiro, Brazil, during 2001-2010
Authors: Cabral Claudius Couto , Morais Ana Carolina Nunes de , Dias Alba Valéria de Almeida Barcelos , Araújo Marcela Garcia , Moreira Wildeberg Cal , Mattos Gláucio Luis Mata
Published: April 2012

INTRODUCTION: Rabies is one of the most known lethal zoonosis, responsible for 55,000 human deaths per year. It is transmitted to humans mainly by the bite of domestic or wild animals infected with the virus. This paper shows the circulation of this virus in non-hematophagous bats in the City of Rio de Janeiro, Brazil. METHODS: A survey was performed on the number of bats that had been sent for diagnosis by the Seção de Virologia of the Instituto Municipal de Medicina Veterinária Jorge Vaitsman and were positive for rabies. The positive animals were identified, and the isolated viruses were sent for antigenic typification with indirect immunofluorescence. The results were compared with the antigenic panel of the Centers for Disease Control and Prevention. RESULTS: During 2001-2010, the laboratory received 555 non-hematophagous bats for rabies diagnosis, with 198 (35.7%) from Rio de Janeiro City. A total of 11 (5.5%) animals were positive for this disease. Antigenic typification revealed the predominance of variant 3 in 9 (81.8%) of the isolated viruses; 1 virus was classified as variant 4 and 1 variant was identified that segregated with the viruses in insectivorous bats. CONCLUSIONS: The data obtained in this study showed the presence of the rabies virus in synanthropic populations of non-hematophagous bats in the City of Rio de Janeiro. The circulation of this agent in these animals represents a serious risk to human and animal health and requires attention and control measures by the authorities.
Biological behavior of Trypanosoma cruzi stocks obtained from the state of Amazonas, Western Brazilian Amazon, in mice
Authors: Monteiro Wuelton Marcelo , Magalhães Laylah Kelre Costa , Oliveira Josué Costa , Guerra Jorge Augusto de Oliveira , Silveira Henrique , Ferreira Luiz Carlos de Lima , Toledo Max Jean de Ornelas , Barbosa Maria das Graças Vale
Published: April 2012

INTRODUCTION: The biological diversity of circulating Trypanosoma cruzi stocks in the Amazon region most likely plays an important role in the peculiar clinic-epidemiological features of Chagas disease in this area. METHODS: Seven stocks of T. cruzi were recently isolated in the State of Amazonas, Brazil, from humans, wild mammals, and triatomines. They belonged to the TcI and Z3 genotypes and were biologically characterized in Swiss mice. Parasitological and histopathological parameters were determined. RESULTS: Four stocks did not promote patent parasitemia in mice. Three stocks produced low parasitemia, long pre-patent periods, and a patent period of 1 day or oscillating parasitemia. Maximum parasitemia ranged from 1,400 to 2,800 trypomastigotes/0.1mL blood. Mice inoculated with the T. cruzi stocks studied showed low positivity during fresh blood examinations, ranging from 0% to 28.6%. In hemoculture, positivity ranged from 0% to 100%. Heart tissue parasitism was observed in mice inoculated with stocks AM49 and AM61. Stock AM49 triggered a moderate inflammatory process in heart tissue. A mild inflammatory process was observed in heart tissue for stocks AM28, AM38, AM61, and AM69. An inflammatory process was frequently observed in skeletal muscle. Examinations of brain tissue revealed inflammatory foci and gliosis in mice inoculated with stock AM49. CONCLUSIONS: Biological and histopathological characterization allowed us to demonstrate the low infectivity and virulence of T. cruzi stocks isolated from the State of Amazonas.
Effects of an exercise program on the functional capacity of patients with chronic Chagas' heart disease, evaluated by cardiopulmonary testing
Authors: Fialho Paloma Hargreaves , Tura Bernardo Rangel , Sousa Andréa Silvestre de , Oliveira Claudia Rosa de , Soares Carla Cristiane Santos , Oliveira Juliana Rega de , Souza Marcus Vinícius , Coelho Marina Pereira , Souza Fernando César de Castro e , Cunha Ademir Batista da , Kopiler Daniel Arkader
Published: April 2012

INTRODUCTION: Despite all efforts to restrict its transmission, Chagas' disease remains a severe public health problem in Latin America, affecting 8-12 million individuals. Chronic Chagas' heart disease, the chief factor in the high mortality rate associated with the illness, affects more than half a million Brazilians. Its evolution may result in severe heart failure associated with loss of functional capacity and quality of life, with important social and medical/labor consequences. Many studies have shown the beneficial effect of regular exercise on cardiac patients, but few of them have focused on chronic Chagas' heart disease. METHODS: This study evaluated the effects of an exercise program on the functional capacity of patients with chronic Chagas' disease who were treated in outpatient clinics at the Evandro Chagas Institute of Clinical Research and the National Institute of Cardiology, Rio de Janeiro, Brazil. The exercises were performed 3 times a week for 1 h (30 min of aerobic activity and 30 min of resistance exercises and extension) over 6 months in 2010. Functional capacity was evaluated by comparing the direct measurement of the O2 uptake volume (VO2) obtained by a cardiopulmonary exercise test before and after the program (p < 0.05). RESULTS: Eighteen patients (13 females) were followed, with minimum and maximum ages of 30 and 72 years, respectively. We observed an average increase of VO2peak > 10% (p = 0.01949). CONCLUSIONS: The results suggest a statistically significant improvement in functional capacity with regular exercise of the right intensity.
Carbohydrate-rich high-molecular-mass antigens are strongly recognized during experimental Histoplasma capsulatum infection
Authors: Tristão Fabrine Sales Massafera , Leonello Paula César , Nagashima Luciene Airy , Sano Ayako , Ono Mário Augusto , Itano Eiko Nakagawa
Published: April 2012

INTRODUCTION: During histoplasmosis, Histoplasma capsulatum soluble antigens (CFAg) can be naturally released by yeast cells. Because CFAg can be specifically targeted during infection, in the present study we investigated CFAg release in experimental murine histoplasmosis, and evaluated the host humoral immune response against high-molecular-mass antigens (hMMAg. >150 kDa), the more immunogenic CFAg fraction. METHODS: Mice were infected with 2.2x10(4) H. capsulatum IMT/HC128 yeast cells. The soluble CFAg, IgG anti-CFAg, IgG anti-hMMAg, and IgG-hMMAg circulating immune complexes (CIC) levels were determined by enzymelinked immunosorbent assay, at days 0, 7, 14, and 28 post-infection. RESULTS: We observed a progressive increase in circulating levels of CFAg, IgG anti-CFAg, IgG anti-hMMAg, and IgG-hMMAg CIC after H. capsulatum infection. The hMMAg showed a high percentage of carbohydrates and at least two main immunogenic components. CONCLUSIONS: We verified for the first time that hMMAg from H. capsulatum IMT/HC128 strain induce humoral immune response and lead to CIC formation during experimental histoplasmosis.
Insights into the clinical and functional significance of cardiac autonomic dysfunction in Chagas disease
Authors: Junqueira Junior Luiz Fernando
Published: April 2012

INTRODUCTION: Exclusive or associated lesions in various structures of the autonomic nervous system occur in the chronic forms of Chagas disease. In the indeterminate form, the lesions are absent or mild, whereas in the exclusive or combined heart and digestive disease forms, they are often more pronounced. Depending on their severity these lesions can result mainly in cardiac parasympathetic dysfunction but also in sympathetic dysfunction of variable degrees. Despite the key autonomic effect on cardiovascular functioning, the pathophysiological and clinical significance of the cardiac autonomic dysfunction in Chagas disease remains unknown. METHODS: Review of data on the cardiac autonomic dysfunction in Chagas disease and their potential consequences, and considerations supporting the possible relationship between this disturbance and general or cardiovascular clinical and functional adverse outcomes. RESULTS: We hypothesise that possible consequences that cardiac dysautonomia might variably occasion or predispose in Chagas disease include: transient or sustained arrhythmias, sudden cardiac death, adverse overall and cardiovascular prognosis with enhanced morbidity and mortality, an inability of the cardiovascular system to adjust to functional demands and/or respond to internal or external stimuli by adjusting heart rate and other hemodynamic variables, and immunomodulatory and cognitive disturbances. CONCLUSIONS: Impaired cardiac autonomic modulation in Chagas disease might not be a mere epiphenomenon without significance. Indirect evidences point for a likely important role of this alteration as a primary predisposing or triggering cause or mediator favouring the development of subtle or evident secondary cardiovascular functional disturbances and clinical consequences, and influencing adverse outcomes.
Comparison among three polymerase chain reaction assays on detection of DNA from Leishmania in biological samples from patients with american cutaneous leishmaniasis
Authors: Silva João Guilherme Lino da , Silva Thiago Miranda da , Peloso Eduardo de Figueiredo , Machado-Coelho George Luiz Lins , Mayrink Wilson , Ariosa Marília Caixeta Franco , Faria e Silva Paulo Márcio de , Marques Marcos José
Published: April 2012

INTRODUCTION: The study analyzed positivity of polymerase chain reaction (PCR) on detection of DNA from Leishmania in patients' samples. METHODS: Extracted DNA was submitted to L150/L152, 13Y/13Z, and seminested PCR (snPCR). RESULTS: Results were evidenced by bands of approximately 120, 720, and 670 bp for L150/L152, 13Y/13Z, and snPCR, respectively. L150/L152, 13Y/13Z, and snPCR positivity indexes were 76.9, 56.4, and 9.2 (p>0.05), respectively, for suspected and 93.7, 68.7, and 84.4 (p<0.05), respectively, for confirmed. CONCLUSIONS: Preliminary results showed that these assays, mainly L150/L152 and snPCR, can detect Leishmania DNA and carry potential on laboratory diagnosis of leishmaniasis.
Advanced megaesophagus (Group III) secondary to vector-borne Chagas disease in a 20-month-old infant
Authors: Rassi Anis , Rezende Joffre Marcondes de , Rassi Junior Anis
Published: April 2012

The authors report the case of a female infant with Group III (or Grade III) megaesophagus secondary to vector-borne Chagas disease, resulting in severe malnutrition that reversed after surgery (Heller technique). The infant was then treated with the antiparasitic drug benznidazole, and the infection was cured, as demonstrated serologically and parasitologically. After follow-up of several years without evidence of disease, with satisfactory weight and height development, the patient had her first child at age 23, in whom serological tests for Chagas disease yielded negative results. Thirty years after the initial examination, the patient's electrocardiogram, echocardiogram, and chest radiography remained normal.
Challenge in the management of infective endocarditis with multiple valvular involvement
Authors: Araújo Izabella Rodrigues de , Nunes Maria do Carmo Pereira , Gelape Claudio Leo , Carvalho Vinicius Tostes , Lacerda Benone Evaristo Rezende Araújo , Oliveira Gustavo Brandão de , Brant Luiza Caldeira , Ferrari Teresa Cristina Abreu
Published: April 2012

We describe the case of a 41-year-old man with congenital heart disease and infective endocarditis (IE), who presented multiple vegetations attached to the pulmonary, mitral, and aortic valves. Three valve replacements were performed, but the patient developed an abscess at the mitral-aortic intervalvular fibrosa and died due to sepsis. We briefly discuss the indications for surgery in IE, emphasizing its role in the treatment of uncontrolled infection.