bluuebunny/crossref_metadata_2025 huggingface dataset:
The Role of Mitochondria in Stem Cell Biology
Authors: Nesti Claudia , Pasquali Livia , Vaglini Francesca , Siciliano Gabriele , Murri Luigi
Published: May 2007

This mini-review summarizes the current literature on the role of mitochondrial DNA mutations and mitochondrial metabolism in stem cell biology. The possible uses of stem cells as a therapeutic tool in mitochondrial disorders are also reported.
Dynamics of an Intervertebral Disc Prosthesis in Human Cadaveric Spines
Authors: Meyers Kathleen N. , Campbell Deirdre A. , Lipman Joseph D. , Zhang Kai , Myers Elizabeth R. , Girardi Federico P. , Cammisa Frank P. , Wright Timothy M.
Published: May 2007

Low-back pain is a common, disabling medical condition, and one of the major causes is disc degeneration. Total disc replacements are intended to treat back pain by restoring disc height and re-establishing functional motion and stability at the index level. The objective of this study was to determine the effect on range of motion (ROM) and stiffness after implantation of the ProDisc®-L device in comparison to the intact state. Twelve L5–S1 lumbar spine segments were tested in flexion/extension, lateral bending, and axial rotation with axial compressive loads of 600 N and 1,200 N. Specimens were tested in the intact state and after implantation with the ProDisc®-L device. ROM was not significantly different in the implanted spines when compared to their intact state in flexion/extension and axial rotation but increased in lateral bending. Increased compressive load did not affect ROM in flexion/extension or axial rotation but did result in decreased ROM in lateral bending and increased stiffness in both intact and implanted spine segments. The ProDisc®-L successfully restored or maintained normal spine segment motion.
Advanced chronic heart failure: A position statement from the Study Group on Advanced Heart Failure of the Heart Failure Association of the European Society of Cardiology
Authors: Metra Marco , Ponikowski Piotr , Dickstein Kenneth , McMurray John J.V. , Gavazzi Antonello , Bergh Claes‐Hakan , Fraser Alan G. , Jaarsma Tiny , Pitsis Antonis , Mohacsi Paul , Böhm Michael , Anker Stefan , Dargie Henry , Brutsaert Dirk , Komajda Michel ,   on behalf of the Heart Failure Association of the European Society of Cardiology
Published: May 2007

Therapy has improved the survival of heart failure (HF) patients. However, many patients progress to advanced chronic HF (ACHF). We propose a practical clinical definition and describe the characteristics of this condition.

Patients that are generally recognised as ACHF often exhibit the following characteristics: 1) severe symptoms (NYHA class III to IV); 2) episodes with clinical signs of fluid retention and/or peripheral hypoperfusion; 3) objective evidence of severe cardiac dysfunction, shown by at least one of the following: left ventricular ejection fraction<30%, pseudonormal or restrictive mitral inflow pattern at Doppler‐echocardiography; high left and/or right ventricular filling pressures; elevated B‐type natriuretic peptides; 4) severe impairment of functional capacity demonstrated by either inability to exercise, a 6‐minute walk test distance<300 m or a peak oxygen uptake<12–14 ml/kg/min; 5) history of >1 HF hospitalisation in the past 6 months; 6) presence of all the previous features despite optimal therapy. This definition identifies a group of patients with compromised quality of life, poor prognosis, and a high risk of clinical events. These patients deserve effective therapeutic options and should be potential targets for future clinical research initiatives.
Clinical trials update from the American College of Cardiology 2007: ALPHA, EVEREST, FUSION II, VALIDD, PARR‐2, REMODEL, SPICE, COURAGE, COACH, REMADHE, pro‐BNP for the evaluation of dyspnoea and THIS‐diet
Authors: Cleland John G.F. , Coletta Alison P. , Clark Andrew L.
Published: May 2007

This article provides information and a commentary on trials relevant to the pathophysiology, prevention and treatment of heart failure, presented at the American College of Cardiology meeting in March 2007. Unpublished reports should be considered as preliminary data, as analyses may change in the final publication.

The ALPHA study suggested that patients with heart failure (HF) due to idiopathic dilated cardiomyopathy who have a negative T‐wave alternans test have a good prognosis and are unlikely to benefit from ICD therapy. EVEREST provides some evidence of short‐term symptom benefit of tolvaptan in patients with acute decompensated HF but no clinically important long‐term benefit. FUSION II failed to show a benefit of nesiritide in patients with chronic decompensated HF. Reducing blood pressure in hypertensive patients improved diastolic dysfunction in VALIDD. Eplerenone did not improve left ventricular remodelling in mild to moderate chronic HF. Selecting HF patients for revascularisation using FDG‐PET imaging did not significantly improve outcome. Crataegus extract added to standard HF therapy did not reduce morbidity or mortality in SPICE. The COURAGE study, conducted in patients without HF or major cardiac dysfunction, showed that PCI did not reduce cardiac morbidity or mortality and can be safely deferred in patients with stable coronary disease on optimal medical therapy. The COACH study failed to show that HF nurse‐intervention could reduce hospitalisations but did show trends to lower mortality, especially amongst patients with reduced ejection fraction; however, the smaller REMADHE study suggested striking benefits on morbidity and mortality. A large study of BNP provided additional information on its ability to distinguish cardiac and pulmonary breathlessness. The importance of dietary intervention in post‐MI patients was highlighted by the findings of THIS‐diet study.
Neurogenesis of GABAergic cells in the retina of malnourished rats
Authors: Silveira A.C.D. , Gardino P.F. , Bevilaqua M.C.N. , Hokoç J.N.
Published: May 2007

The present study investigated how prenatal protein malnutrition affects the neurogenesis of GABAergic cells in the retina. Rats were treated with a multi‐deficient diet, with only 8% of protein that was administered during the gestational and suckling periods. Pregnant mothers and pups from malnourished and control (fed with 22% protein) groups received a single intra‐peritoneal injection of [3H]‐thymidine at six developmental ages, from E14 to PN4, and the pups were sacrificed at PN18. Eyes were enucleated and cryosections of the retina were double labeled for GABA‐immunocytochemistry and for autoradiography. The percentage of double labeled cells, in the retinal inner nuclear and ganglion cell layers, was determined for both groups. Qualitative and quantitative results showed that double labeled cells [GABA(+)/thymidine(+)] were present since E14, when mitotic activity for GABAergic cells starts, in both GCL and INL layers. The peak rate of GABAergic cell generation was reached in control animals injected with [3H]‐thymidine at E18 in both central and peripheral sectors of the retina, but only at E20 in the malnourished group. The generation of cells of GABA phenotype showed a significant delay in both layers of the retina in the malnourished group. At PN4, close to the age that GABAergic mitotic activity ends in the control group, double labeled cells were significantly higher in the malnourished group. Our data showed a delay in GABAergic cell generation in the malnourished group when compared to the control group that might result in significant functional consequences in the developing retina.
Comparison of a new modified laparoscopic presacral neurectomy and conventional laparoscopic presacral neurectomy in the treatment of midline dysmenorrhea
Authors: Chang C.Y.Y. , Chang W.C. , Hung Y.C. , Ho M. , Yeh L.S. , Lin W.C.
Published: May 2007

Objective: To describe a newly modified laparoscopic presacral neurectomy procedure and to evaluate the long‐term benefits of the surgery as a treatment for midline dysmenorrhea. Method: Eighty‐eight reproductive female patients with midline dysmenorrhea were enrolled in the non‐randomized prospective study. There were fifty‐five patients in the modified laparoscopic presacral neurectomy (MLPSN) group and thirty‐three patients in the conventional laparoscopic presacral neurectomy (LPSN) group. All patients received post‐surgery follow‐up of more than eight years for evaluation with respect to pain relief, recurrence, and complications. Results: Upon receipt of surgery, the MLPSN and the LPSN groups both demonstrated a significant decrease (P < 0.001) in the mean pain score when compared to the pre‐surgery mean pain scores. However, the probability of recurrence during the eight years of follow‐up was 81.8% (27 patients) in the LPSN group, compared to 43.6% (24 patients) in the MLPSN group, resulting in a significantly lower long‐term recurrence rate in the MLPSN group, compared to the LPSN group (P < 0.05). No patients in the MLPSN group had long‐term complications and one patient had constipation after surgery in the LPSN group. Conclusion: The modified laparoscopic presacral neurectomy procedure provides an alternative for those patients who suffer intractable midline dysmenorrhea. This surgery is relatively simple and safe and could result in a satisfactory long‐term outcome in the intervention of midline dysmenorrhea.
Relapsed or refractory gestational trophoblastic neoplasia treated with the etoposide and cisplatin/etoposide, methotrexate, and actinomycin D (EP‐EMA) regimen
Authors: Mao Yuyan , Wan Xiaoyun , Lv Weiguo , Xie Xing
Published: May 2007

Objective To evaluate the effectiveness of the etoposide and cisplatin/etoposide, methotrexate and actinomycin D (EP‐EMA) regimen in patients with gestational trophoblastic neoplasia who had been successfully treated with the etoposide, methotrexate, and actinomycin D/cyclophosphamide and vincristine (EMA‐CO) regimen but experienced a relapse, or who became refractory to EMA−CO treatment. Methods From January 1999 to December 2005, 18 patients with gestational trophoblastic neoplasia who had been successfully treated with the EMA‐CO regimen but sustained a relapse (n = 7) or who became refractory to it (n = 11) were treated with the EP‐EMA regimen. The effectiveness, adverse effects, and tolerated dose intensity of the EP‐EMA regimen were retrospectively analyzed. Results The 18 patients received a total of 74 cycles of the EP‐EMA regimen and 12 (66.7%) achieved complete remission. Nine of the 11 patients (81.8%) apparently resistant to the EMA‐CO regimen achieved complete remission. However, only 3 of the 7 patients (42.9%) who experienced a relapse after treatment with the EMA‐CO regimen achieved complete remission. The main adverse effects of the EP‐EMA regimen were myelosuppression and gastrointestinal problems. Because of myelosuppression and hepatotoxicity, only 56.8% of the patients could be treated with the planned dose intensity. Conclusion EP‐EMA may be an effective option for the treatment of gestational trophoblastic neoplasia in patients resistant to treatment with the EMA‐CO regimen. However, it does not seem to benefit all the patients who experienced a relapse after treatment with the EMA‐CO regimen.
The joint influence of technology uncertainty and interorganizational interaction on external technology integration success
Authors: Stock Gregory N. , Tatikonda Mohan V.
Published: May 2007

This paper empirically examines the acquisition of a technology from a source outside the firm and its incorporation into a new or existing operational process. We refer to this key activity in process innovation as external technology integration. This paper develops a conceptual framework of external technology integration based on organizational information processing theory and technology management literature. The primary hypothesis underlying the conceptual framework is that external technology integration will be most successful when the level of interaction between the source of the technology and recipient of the technology is appropriately matched, or fit, to the characteristics of the technology to be integrated. The conceptual framework also develops other hypotheses relating to contextual factors that may also influence the success of external technology integration. A cross‐sectional survey methodology is employed to test the four hypotheses of the conceptual framework, with the results indicating strong support for the fit hypothesis and general support for the contextual hypotheses. The paper closes with a discussion of the implications of this study for both theory and practice.
The Governance of Hydro-electric Dams in Brazil
Authors: McCORMICK SABRINA
Published: May 2007

This paper examines the governance of hydroelectric dam planning in Brazil with a particular focus on two factors: first, governmental institutions that aim to provide participatory mechanisms for civil society, and second, new participatory institutions created by civil society to remedy the lack of meaningful participatory measures. One example of the latter are new collaborative research projects, which have changed dam building policies and governmental thinking about participation. It is argued here that these kinds of collaboration are fundamental to making dam-building policy more accountable to local citizens. The analysis demonstrates that lay/expert collaborations provide pathways through which affected people can contest inaccurate official scientific reports, in turn influencing the policy process. I examine six such participatory projects across the country: four are nationally based and two are international in scope. A four-pronged typology is used to analyse the processes and outcomes of these collaborations. This typology reveals multiple types of knowledge-sharing that constitute concrete means to implement participation in environmental policy, hence advancing the democratisation of environmental governance.
A Poverty of Imagination: George W. Bush's Policy in Latin America
Authors: LEOGRANDE WILLIAM M.
Published: May 2007

Washington's challenge during George W. Bush's presidency was to define a new relationship with Latin America beyond free trade and neoliberal economics – a relationship responsive to the region's demand for social and economic justice. Preoccupied by the wars in Afghanistan and Iraq, the Bush administration failed this challenge. The president left his Latin American policy in the hands of conservative cold warriors who reacted with hostility to the election of ‘new left’ socialists and populists. As a result, Washington's reputation and relations in Latin America deteriorated dramatically.
Movement Activists and Partisan Insurgents
Authors: Miroff Bruce
Published: May 2007

On the opening day of the 1972 Democratic convention, the women's caucus gave George McGovern a standing ovation. Its first meeting was packed, with 700 female delegates in attendance, exuberant over their numbers at the convention—triple the representation from four years earlier—and their new clout in presidential politics. Of all of the presidential candidates appearing, only Shirley Chisholm, the first African-American woman to run for president, was greeted with enthusiasm comparable to the warm reception for McGovern. Most of the women at the meeting were fervently anti-war and respected McGovern for his early and courageous stance on Vietnam. However, the size of the gathering attested to another of McGovern's achievements: his chairing of the reform commission that had rewritten the Democratic Party's rules on delegate selection, leading to the huge leap in the representation of women. As Liz Carpenter, a former White House aide to LBJ, put it when introducing McGovern, “We know we wouldn't be here if it hadn't been for you.”
American Political Development from Citizens' Perspective: Tracking Federal Government's Presence in Individual Lives over Time
Authors: Mettler Suzanne , Milstein Andrew
Published: May 2007

Although scholars of American political development (APD) have helped transform many aspects of the study of U.S. politics over the last quarter-century, they have barely begun to use the powerful analytical tools of this approach to elucidate the relationship between government and citizens. APD research has probed deeply into the processes of state-building and the creation and implementation of specific policies, yet has given little attention to how such development affects the lives of individuals and the ways in which they relate to government. Studies routinely illuminate how policies influence the political roles of elites and organized groups, but barely touch on how the state shapes the experiences and responses of ordinary individuals. As a result, we know little about how governance has influenced citizenship over time or how those changes have, in turn, affected politics.
State Regulation of Corporations in the Late Nineteenth Century: A Critique of the New Jersey Thesis
Authors: Chausovsky Jonathan
Published: May 2007

The transformation from nineteenth-century proprietary capitalism to twentieth-century corporate capitalism involved fundamental changes in the rights of business corporations as market actors. At the end of the Civil War, corporations were controlled by individuals and families. At the turn of the twentieth century, corporations were in the midst of a merger movement that resulted in firms with concentrated capital, large numbers of shareholders, and control residing in management. New legal rights needed to be put in place to support this more advanced level of capitalist development. Most scholarship on the transformation of business corporation rights has focused on changes in the courts and in Congress, principally in regard to antitrust regulation. In addition, however, there was another locale essential to transforming the shape of the business organization: state legislatures developed and allocated corporate rights. Nineteenth-century state laws sought not only to enable the corporation to exist, but also to regulate its place within the state economy. With the advent of corporate capitalism at the turn of the twentieth century, state capacity to regulate through statutory law waned.
Challenges and Results for Quantitative Piezoelectric Hysteresis
Measurements by Piezo Force Microscopy
Authors: Huey B. D. , Nath R. , Garcia R. E. , Blendell J. E.
Published: May 2007

Atomic Force Microscopy (AFM) has become a ubiquitous tool for
analyzing the topography of a wide variety of materials, especially as
nanoscale features become more significant for both understanding as
well as determining materials properties [1]. Many AFM variations have
also been developed for measuring surface properties beyond
straightforward cartography. In many of these cases, the contrast
mechanisms are often either extremely complex, or not well understood,
even though the principles are simple. For example, Piezo-Force
Microscopy (PFM) is relatively easy to understand and use in a standard
lab for measuring electromechanical properties of materials, but care
must be taken in order to obtain quantitative results as described
below.
Polymeric Nanostructures for Drug Delivery: Characterization by
Atomic Force Microscopy
Authors: Mosqueira V. C. F. , Leite E. A. , Barros C. M. , Vilela J. M. C. , Andrade M. S.
Published: May 2007

Formal definitions of nanotechnological devices for drug delivery
typically feature the requirements that the device itself or its
essential components be man-made, and in the 1-1000 nm range in at least
one dimension [1]. The known nanovectors or nanostructures can be filled
with drugs for different therapies and for diagnostical aims. Targeting
moieties can also be attached to their surface. Polymeric nanovectors
are generally made from biodegradable polymers such as polyesters, for
example, poly-e-caprolactone (PCL). The drug delivery system known as
nanocapsules (NCs) can be defined as a complex nanovector that is
composed by a polymeric wall surrounding an oil core, where lipophilic
drugs can be encapsulated. The advantages of NCs compared to other
nanovectors are the high entrapment efficiencies of lipophilic drugs,
low polymer content and low inherent toxicity. On the other hand,
because of its complex blend of components NCs suspension allow several
forms of nanovectors to be present at the same time, such as
nanospheres, liposomes and nanoemulsions [2]. These ‘contaminants’ would
be present in accordance with the type of formulation and method of
preparation. Atomic force microscopy (AFM) has been used as a method for
imaging the surfaces of liposomes [3] and nanospheres [4] allowing
information in nanoscaled dimensions. In the present work, the NCs were
prepared loading two different drugs, the antifungal albaconazole (ABZ),
showing a crystalline drug structure and the antimalarial halofantrine
(Hf) free base, having an amorphous form. These drugs possess high
lipophilic character, which favours the association of the drug with the
oily core, with drug loadings above 94%. Herein we studied the behavior
of ABZ-loaded and Hf-loaded NCs through the AFM technique, searching to
analyze and understand possible alterations induced by the drug
inclusion in these nanostructures.
Poly-Caprolactone Nanocapsules Morphological Features by Atomic
Force Microscopy
Authors: Leite E. A. , Vilela J. M. C. , Mosqueira V. C. F. , Spangler Andrade M.
Published: May 2007

Polymeric nanoparticles containing an oily core, named nanocapsules (NCs),
have been widely studied in the life sciences field due to their
therapeutic potentialities of drug targeting in the body accompanied
also by its larger stability in the biological fluids compared to other
colloidal carriers. Many studies have shown different applications of
nanocapsules for therapeutic use concerning their properties [1] of
loading poorly water-soluble drugs, protection drugs from inactivation
in the gastro-intestinal tract [2], gastric mucosal toxicity protection
[3,4], increased drug permeation through mucous epithelium [5,6] and
prolongation of drugs in blood circulation for surface modified
nanocapsules [7]. The characterization of the nanocapsules is frequently
performed by mean size, surface charge of the particles (zeta
potential), hydrophobicity, drug loading yield and release kinetic [8].
These features are of great importance for biodistribution profile and
interactions with the cells of mononuclear phagocyte system of any
injected particles by intravenous route [1]. However, few data on
structural organization of the nanocapsules constituents are available
in literature and several hypotheses only suggest the presence of an oil
"capsular" structure surrounded by a polymeric envelope. Recently,
atomic force microscope (AFM) has been used as a method for imaging the
surfaces of colloidal systems, such as liposomes [9,10] and nanospheres
[11], supplying high resolution information in nanoscaled dimension. In
the present work, unloaded nanocapsules were deposited on mica in order
to analyze by AFM the diameter, height, particles polydispersion, and
topographic characteristics of nanocapsule surface.
Adsorption Behaviour of Creatine Phosphokinase onto Silicon Wafers:
Comparison between Ellipsometric and Atomic Force Microscopy Data
Authors: Pancera S. M. , Gliemann H. , Petri D. F. S. , Schimmel T.
Published: May 2007

Protein adsorption plays a major role in a variety of important
technological and biological processes [1-2] and the understanding of
the fundamental factors that determine protein adsorption are imperative
to the development of biocompatible materials and biotechnological
devices [3-4] as for example biosensors [5]. The adsorption of proteins
on surfaces is a complex process. Due to the large size and different
shapes of these adsorbing particles, the interactions between the
adsorbed proteins on the surface can be strongly influentiated by the
fact that the particles may undergo conformational changes upon
adsorption [6-7]. In a previous work the adsorption behaviour of
creatine phosphokinase (CPK) onto hydrophilic (silicon wafers and
amino-terminated surfaces) and hydrophobic (Polystyrene, PS, coated
wafers) substrates was investigated by means of null-ellipsometry and
contact angle measurements [8]. This previous ellipsometric study led to
a model, where CPK adsorption takes place in four stages: (i) a
diffusive one, where all the arriving biomolecules are immediately
adsorbed; (ii) the arriving biomolecules might stick on the latter and
afterward diffuse to the free sites on the substrate, followed by
conformational changes [6-7], (iii) formation of a monolayer and (iv)
continuous and irreversible adsorption. A multilayer system might be
formed, as well as aggregation processes might play a role at this
stage. In this work Atomic Force Microscopy (AFM) measurements under
water were done in order to confirm this four steps model and to observe
changes in the film topography and homogeneity along the adsorption
process. The thickness of the adsorbed CPK biofilm obtained by
ellipsometry was also compared with that obtained by the wet AFM method.
Atomic Force Microscopy: A Useful Tool for Evaluating Aggregation
of Lipases
Authors: Baron A. M. , Lubambo A. F. , Lima V. M. G. , de Camargo P. C. , Mitchell D. A. , Krieger N.
Published: May 2007

Lipases (glycerol ester hydrolases, E.C. 3.1.1.3) are enzymes of
great industrial interest due to their ability to catalyze a broad range
of hydrolytic and synthetic reactions. They find applications in the
synthesis of compounds used in clinical, nutritional, environmental,
pharmaceutical and chemical fields. For example, lipases are used to
catalyze key intermediate steps in the synthesis of biologically active
compounds such as Naproxen, Ibuprofen and Atenolol [1]. Depending on the
application, lipases may need to be purified and characterized
biochemically before they can be used. However, the purification of
microbial lipases is often made difficult by the presence of high
molecular weight aggregates. These aggregates can form due to the
presence, in the fermentation medium, of lipids used to induce the
production of the enzyme by the microorganism or simply due to
hydrophobic interactions amongst the enzyme molecules themselves [2]. In
previous work, we characterized a new lipase produced by Bacillus
megaterium CCOC P2637. The enzyme eluted in the void volume during gel
filtration chromatography, indicating that it was present in the form of
a high molecular weight aggregate. This aggregate was dispersed when a
gradient of 60% (v/v) isopropanol was used, but formed again when the
enzyme was injected in a gel filtration column for further purification,
even when the elution buffer contained 20% (v/v) isopropanol. Further,
when the enzyme was diluted in buffer (phosphate pH 7.0 20 mM)
containing 30% isopropanol, its specific activity was double the
activity obtained by diluting in buffer without isopropanol [3].
Interface between Adjacent UV-Treated or Detergent-Treated Vaccinia virus Particles
Authors: Cardoso A. V. , Trindade G. S.
Published: May 2007

While investigating isolated or agglomerates of treated Vaccinia
virus intracellular mature (IMV) particles in atomic force microscopy
(AFM) equipment we noticed that in some occasions the enveloped
particles had been totally disrupted, with the interior being spread
around. We have also observed in these samples what appear to be some
rather intriguing viral surface interactions. Instead of showing a clear
division between individual virions the particles seem to be continuous
at the interfaces that show coalescence. In order to understand what was
happening we focused our attention on the analysis of the images of the
interface between virions particles, trying to find out what was the
explanation for such type of particle surface interaction and in which
conditions it would take place.
Combining Nanoindentation with Atomic Force Microscopy to Characterize the Mechanical Properties of each Microconstituent of Low Carbon Steel
Authors: Shuman D. J. , Oliveira F. L. G. , Andrade M. S. , Cota A. B.
Published: May 2007

In the last decades several investigations have been conducted with
the objective of studying the
microstructural characteristics and mechanical properties in low carbon
microalloyed steel [1,2].
These steels contain a polyphase microstructure, with complex mixture of
bainite, MA constituent
(martensite-austenite residual), pearlite, ferrite and martensite. They
are often used in the automobile
industry, in the production pipelines for the transport of gas and oil
in areas of sub-zero temperature
and in the naval ship construction, because they possess high strength,
high toughness at low
temperature and good weldability.
Atomic Force Microscopy Applied to the Study of Dewetting Patterns
of Thin Films from Polymer Solutions
Authors: Rezende C. A. , Lee L. -T. , Galembeck F.
Published: May 2007

Stable and defect-free films are required for many technological
applications, while controlled dewetting processes are important for
producing thin film microstructuring for microelectronics, optical
devices and biochip technology. In this work, we study the dewetting
features formed by drying an aqueous solution of a charged polymer
deposited on a mica substrate. A rich variety of morphologies can be
formed, including holes, polygonal networks, droplets and elongated
structures. The dewetting behavior depends on film thickness and on the
charge density on the polymer that can be controlled by surfactant
addition. The various nanoscale morphological patterns that are formed
may be applied as a potential method for surface nanostructuring.
Atomic Force Microscopy (AFM) Studies of Cured Self-Assembled Films
for Chemical Sensor Applications
Authors: Medeiros E. S. , Bernardes Filho R. , Martinez R. A. , Gregorio Filho R. , Mattoso L. H. C.
Published: May 2007

The use of ultrathin polymer films as sensoactive layers in chemical
sensors has received great interest in recent years due to many
advantages such as the wide choice of polymeric system (polymer types
and/or combination, dopants in conducting polymers, etc), and the
possibility of tailoring the properties of these films in terms of
sensitivity and selectivity by an efficient control of the film
formation process [1]. Among the techniques used for ultrathin films
formation, self-assembly (SA) offers several advantages since the
substrate can take any form and size, deposition time is independent of
the substrate area, there are no requirements for additional equipments
and/or clean rooms, and a large quantity of materials can be assembled
into thin films [2-8].
Adhesion Forces for Mica and Silicon Oxide Surfaces Studied by
Atomic Force Spectroscopy (AFS)
Authors: Leite F. L. , Ziemath E. C. , Oliveira Jr. O. N. , Herrmann P. S. P.
Published: May 2007

The possibility of analyzing surfaces at the nanoscale provided by
atomic force microscopy [1] (AFM) has been explored for various
materials, including polymers [2], biological materials [3] and clays
[4]. Further uses of AFMs involved nanomanipulation [5] and measurements
of interaction forces, where the latter has been referred to as atomic
force spectroscopy (AFS) [6]. Measurements of surface-surface
interactions at the nanoscale are important because many materials have
their properties changed at this range [7]. For samples in air, the
interactions with the tip are a superimposition of van der Waals,
electrostatic and capillary forces. A number of surface features can now
be monitored with AFS, such as adsorption processes and contamination
from the environment. Many implications exist for soil sciences and
other areas, because quantitative knowledge of particle adhesion is
vital for understanding technological processes, including particle
aggregation in mineral processing, quality of ceramics and adhesives. In
this paper, we employ AFS to measure adhesion (pull-off force) between
the AFM tip and two types of substrate. Adhesion maps are used to
illustrate sample regions that had been contaminated with organic
compounds.
The Effect of -Cyclodextrin Inclusion on the Morphology of
[Ru(bpy)2Cl(BPEB)](PF6) Films by Scanning Force Microscopy
Authors: Toma S. H. , Nakamura M. , Toma H. E.
Published: May 2007

Molecular level organization has been a subject of great relevance in
supramolecular chemistry and nanotechnology. Supramolecular chemists
count on the ability of molecules to form several kinds of organization,
allowing the development of nanoscaled devices. In this way, the
scanning probe microscopy provides a great tool for characterization,
manipulation and interfacing such devices [1]. Regarding the ruthenium
complexes [Ru(bpy)2Cl(BPEB)](PF6) and {[Ru(bpy)2Cl]2(BPEB)}(PF6)2, where
bpy = 2,2'-bipyridine, the presence of the BPEB
(1,4-bis[4-pyridyl)ethenyl]benzene) ligand has an important role as a
recognition site for van der Waals interactions (Figure 1). On the other
hand, cyclodextrins are macrocyclic molecules bearing a hydrophobic
cavity that can support several types of guest molecules [2-3]. In this
work we are showing the influence of the recognition site of the BPEB
ligand and the formation of an inclusion compound in the patterning
structures of films deposited over mica substrates, by SFM microscopy.
Characterization by Atomic Force Microscopy of Electrodeposited
Films of Polypyrrole Dinitrobenzoyl-derivative
Authors: Ribeiro A. S. , de O. Ribeiro L. M. , Silva Jr. J. G. , Navarro M. , Tonholo J.
Published: May 2007

Although the development of conducting polymers is very recent, such
materials have already been shown to possess a number of useful
properties that may be exploited in a range of technological
applications. In particular, the representative conducting polymer
polypyrrole (PPy) has been the subject of considerable research interest
owing to its facile polymerisation and practical application in products
as diverse as gas sensors [1], electrochromic devices [2] and battery /
capacitor components [3].
Surface Modification of a-C:H(N) Thin Films by Plasma Treatment
Authors: von Mühlen L. , Simao R. A. , Achete C. A.
Published: May 2007

Surface chemistry and topography of materials are generally
preponderant factors in a series of material properties, such as
adhesion, wettability, friction and optical properties [1]. Wettability
of films, for example, can be altered significantly by modifying its
surface roughness and also by incorporating functional groups. Plasma
treatment is a powerful and versatile way to modify surface properties
of amorphous nitrogen-incorporated carbon thin films (a-C:H(N)) and
obtain materials with improved properties, once it is possible to modify
the surfaces in a controlled way by specific settings of plasma
conditions. [2 - 4]
AFM Characterization of Composite Materials Containing Iron in a
Resin Host Based on Styrene and Divinylbenzene
Authors: de Santa Maria L. C. , Costa M. A. S. , Senna L. F. , Silva M. R. , Simao R. A.
Published: May 2007

The development of composite materials containing small metal or
metal oxides particles has attracted a great deal of attention for their
interesting chemical, physical and magnetic properties, providing their
use for several technological applications. However, it is necessary
that a complete evaluation of the morphological features of these
composite be performed and correlated to the above mentioned properties.
Therefore, the aim of this work was to use VP-SEM and AFM to investigate
the morphology and the phase difference of composite materials based on
styrene (STY) and divinylbenzene (DVB), containing iron particles. MFM
analysis was also carried out to verify the magnetic properties of
surface iron particles.
Welcome form the Program Committee
Authors: Kotula Paul , Marko Mike , Gauvin Raynald , Lucas Gabriel , Dekanich Steven , Beniac Daniel
Published: May 2007

Microscopy and Microanalysis 2006 will be the premiere meeting of the
year for scientists and technologists interested in learning about the
latest advances in applications and techniques for the analysis of a broad
range of materials in the biological and physical sciences, as well as
nano- and bio-technology. M&M-2006 will again host the largest
commercial exhibition of microscopy and microanalysis equipment and
related accessories in the world. In addition to the usual sponsoring
societies, the Microscopy Society of America (MSA), and the Microbeam
Analysis Society (MAS), the International Metallographic Society (IMS)
will again be a co-sponsoring society for the meeting. We are also
fortunate that the Microscopical Society of
Canada/Société de Microscopie du Canada (MSC/SMC)
will also be co-sponsoring the meeting this year. The M&M-2006
Executive Program Committee, comprised of co-chairs from each of the
sponsoring societies, has put together a comprehensive scientific program
that will encompass the state-of-the art in microscopy and microanalysis
in 2006, and we look forward to welcoming you to Navy Pier!
Gas hydrate property measurements in porous sediments with resonant ultrasound spectroscopy
Authors: McGrail B. P. , Ahmed S. , Schaef H. T. , Owen A. T. , Martin P. F. , Zhu T.
Published: May 2007

Resonant ultrasound spectroscopy was used to characterize a natural geological core sample obtained from the Mallik 5L‐38 gas hydrate research well at high pressure and subambient temperatures. Using deuterated methane gas to form gas hydrate in the core sample, it was discovered that resonance amplitudes are correlated with the fraction of the pore space occupied by the gas hydrate crystals. A pore water freezing model was developed that utilizes the known pore size distribution and pore water chemistry to predict gas hydrate saturation as a function of pressure and temperature. The model showed good agreement with the experimental measurements and demonstrated that pore water chemistry is the most important factor controlling equilibrium gas hydrate saturations in these sediments when gas hydrates are formed artificially in laboratory pressure vessels. With further development, the resonant ultrasound technique can provide a rapid, nondestructive, field portable means of measuring the equilibrium P‐T properties and dissociation kinetics of gas hydrates in porous media, determining gas hydrate saturations, and may provide new insights into the nature of gas hydrate formation mechanisms in geologic materials.
Toward direct, micron‐scale XRF elemental maps and quantitative profiles of wet marine sediments
Authors: Böning Philipp , Bard Edouard , Rose Jérôme
Published: May 2007

Here we describe a chemical analysis technique for Ca, Fe, K, Sr, Ti, and S using a recently developed Micro‐XRF analyzer (Micro‐XRF) with a 100‐μm resolution and an XRF whole‐core scanner (XRF‐S) with a 5‐mm resolution for selected sediment sections from a continental margin sediment core. The Micro‐XRF produces highly resolved element maps of individual sections, and the calculation of individual continuous element profiles is based on overlap measurements of successive sections. By means of discrete subsamples analyzed by ICP‐OES, the two XRF data sets are successfully calibrated to provide quantitative profiles of Ca, Fe, K, Sr, and Ti. We discuss the advantages and limitations of both XRF techniques. A comparison of the two independent XRF data sets demonstrates the overall high consistency and accuracy of both techniques. The resulting element profiles and detailed XRF maps clearly show that the Micro‐XRF is a powerful tool for studying at high resolution the chemical transitions linked to paleoenvironmental changes. For example, the discrimination between provenance changes and diagenetical effects on the Fe profile can be achieved by the combined inspection of the Fe/Ti profile and S maps. This highlights the usefulness of the XRF maps for clarification of profile ambiguities and clearly distinguishes the Micro‐XRF from other technical devices producing elemental profiles only.
Impact of terrestrial biosphere carbon exchanges on the anomalous CO2 increase in 2002–2003
Authors: Knorr W. , Gobron N. , Scholze M. , Kaminski T. , Schnur R. , Pinty B.
Published: May 2007

Understanding the carbon dynamics of the terrestrial biosphere during climate fluctuations is a prerequisite for any reliable modeling of the climate‐carbon cycle feedback. We drive a terrestrial vegetation model with observed climate data to show that most of the fluctuations in atmospheric CO2 are consistent with the modeled shift in the balance between carbon uptake by terrestrial plants and carbon loss through soil and plant respiration. Simulated anomalies of the Fraction of Absorbed Photosynthetically Active Radiation (FAPAR) during the last two El Niño events also agree well with satellite observations. Our model results suggest that changes in net primary productivity (NPP) are mainly responsible for the observed anomalies in the atmospheric CO2 growth rate. Changes in heterotrophic respiration (Rh) mostly happen in the same direction, but with smaller amplitude. We attribute the unusual acceleration of the atmospheric CO2 growth rate during 2002–2003 to a coincidence of moderate El Niño conditions in the tropics with a strong NPP decrease at northern mid latitudes, only partially compensated by decreased Rh.
Global 30–240 keV proton precipitation in the 17–18 April 2002 geomagnetic storms: 1. Patterns
Authors: Fang Xiaohua , Liemohn Michael W. , Kozyra Janet U. , Evans David S. , DeJong Anna D. , Emery Barbara A.
Published: May 2007

Global 30–240 keV proton precipitation patterns during the 17–18 April 2002 magnetic storm events were generated using newly developed 3‐hour data products of the medium energy proton and electron detector (MEPED) on board the NOAA‐15 and ‐16 satellites. The observational data set was sorted in 1‐degree corrected magnetic latitude (CML) and 8‐min magnetic local time (MLT) bins. To achieve global coverage, the missing MLT data were filled by interpolation techniques in each 1‐degree CML interval. The resulting global 30–240 keV proton precipitation maps, available on a 3‐hour cadence, provide new information on the development and variability in the structure of incident high‐energy protons on a timescale commensurate with the growth and decay of the plasma sheet and ring current. The change of energetic proton precipitation patterns in the April 2002 storms is quantified in terms of three aspects: hemispheric integrated total particle energy input, midnight proton oval equatorward boundary, and position of proton precipitation peak. In a general sense, as magnetospheric activity intensified, the midnight equatorward boundary tended to move to the lower latitude, while the precipitation peak moved equatorward and westward away from midnight, in agreement with ring current motion. It is well illustrated that energetic proton precipitation patterns can serve as a valuable diagnostic tool for investigating the inner magnetospheric activity.
Storm‐time magnetic configurations at geosynchronous orbit: Comparison between the main and recovery phases
Authors: Ohtani S. , Ebihara Y. , Singer H. J.
Published: May 2007

The present study statistically examines storm‐time geosynchronous magnetic configurations in terms of storm phase, storm intensity, and magnetic local time. It is found that the nightside geosynchronous magnetic field is more stretched with increasing ∣Sym‐H∣irrespective of the storm phase, but for a given value of Sym‐H the magnetic field tends to be more stretched during the main phase than during the recovery phase. This result suggests that the relative contribution of the tail current to Sym‐H is larger during the main phase than during the recovery phase. Interestingly, the tendency is just the opposite in the midday sector. That is, the geosynchronous magnetic field is less stretched during the main phase than during the recovery phase. It is suggested from a storm‐time ring current simulation that the ring current is indeed weakened in the midday sector during the main phase as enhanced magnetospheric convection sweeps ions on previously closed trajectories to the dayside magnetopause. Reflecting the opposite storm‐phase dependences of the dayside and nightside magnetic field, the geosynchronous magnetic configuration is significantly more asymmetric during the main phase than during the recovery phase, and the degree of the asymmetry increases with ∣Sym‐H∣. Most importantly, the asymmetry is predominantly between day and night rather than between dawn and dusk as expected from the conventional model of the partial ring current. This result suggests that the dawn‐dusk asymmetry of the low‐ and midlatitude ground magnetic depression, which the partial ring current model sought to explain, can be attributed mostly to field‐aligned currents.
Centennial changes in the solar wind speed and in the open solar flux
Authors: Rouillard A. P. , Lockwood M. , Finch I.
Published: May 2007

We use combinations of geomagnetic indices, based on both variation range and hourly means, to derive the solar wind flow speed, the interplanetary magnetic field strength at 1 AU and the total open solar flux between 1895 and the present. We analyze the effects of the regression procedure and geomagnetic indices used by adopting four analysis methods. These give a mean interplanetary magnetic field strength increase of 45.1 ± 4.5% between 1903 and 1956, associated with a 14.4 ± 0.7% rise in the solar wind speed. We use averaging timescales of 1 and 2 days to allow for the difference between the magnetic fluxes threading the coronal source surface and the heliocentric sphere at 1 AU. The largest uncertainties originate from the choice of regression procedure: the average of all eight estimates of the rise in open solar flux is 73.0 ± 5.0%, but the best procedure, giving the narrowest and most symmetric distribution of fit residuals, yields 87.3 ± 3.9%.
Seasonal probability dispersion maps in the Mediterranean Sea obtained from the Mediterranean Forecasting System Eulerian velocity fields
Authors: Pizzigalli Claudia , Rupolo Volfango , Lombardi Emanuele , Blanke Bruno
Published: May 2007

This paper presents a method to build seasonal probability dispersion maps from numerical Lagrangian trajectories as well as a user‐friendly web site containing the results. The main aim is to provide useful tools for the description of dispersion properties at the Mediterranean Sea surface. Trajectories were obtained integrating with an off‐line Lagrangian algorithm the Eulerian velocity fields, from January 2000 to December 2004, provided by the ocean general circulation model Modular Ocean Model used in the Mediterranean Forecasting System project. The statistics of dispersion properties over the entire surface of the Mediterranean Sea is calculated from the time evolution of “clusters” of numerical particles released in nonoverlapping grid boxes. Some examples of seasonal probability dispersion maps taken from the web site are shown and discussed. The results are checked against drifters of the Mediterranean Surface Drifter Database (1986–1999) by comparing the statistics of numerical and observed trajectories. The validation shows both deficiencies and skills of the methodology proposed for estimating Lagrangian dispersion variability. It also gives a starting point for discussion about future developments and improvements.