bluuebunny/crossref_metadata_2025 huggingface dataset:
Integrated Multizone Low-Cost Intelligent Completion for Mature Fields
Authors: Pinto H. L. da C. P. , Silva M. F. , Izetti R. G. , Guimarães G. B.
Published: December 2007

A well equipped with downhole flow control and monitoring devices provide tools to manage reservoir and well performance. Many optimization techniques have been applied in conjunction with commercial reservoir simulators with detailed multisegment well model to improve ultimate recovery. It is important to know that all the benefits of the reservoir optimization can be lost if the availability and appropriate control of the artificial lift is not used.

A well equipped with three on-off type flow control valves and four pressure and temperature optical transducer: one for each zone plus one more above the production packer in combination with a rod-pump control with moderate service condition specifications is described.

Standardization of the connectivity between automation of the intelligent completion and artificial lift is necessary for a vendor-independent integration, which becomes more cost-effective by using open industry standard protocols. This also allows the use of different supervisory software, reducing the impact of changing systems already in use without losing the flexibility of choosing a solution that has some custom features or that are cheaper.

This paper will discuss both the benefits resulting of the integration between intelligent completion and artificial lift automation. The value added to provide better decision making to respond immediately to unexpected changes, the need of satisfy reliability demands of the operational people and the issues involving the use of intelligent completion in mature fields.
Real-Time Field Surveillance and Well Services Management in a Large Mature Onshore Field: Case Study
Authors: Ormerod L. , Sardoff H. , Wilkinson J. , Erlendson B. , Cox B. , Stephenson G.
Published: December 2007

This paper describes the planning for, implementation of and results generated by a real-time field surveillance and well services management system, as it was deployed in an onshore mature field in California USA. The motivation behind the deployment of this system was simultaneously to improve efficiency and reduce operating costs in this large field with over 1,000 wells.

The paper will describe how the business processes and supporting workflows were defined. This is an essential step before any technology can be deployed. The challenges of data management included not only the automatic handling of very large quantities of real-time data, but also the management of inventory, and the integration of field-level data with corporate-level data. Historical data had to be brought into, and made compatible with, the new system. The technologies required for this project included the software systems themselves, but also the integration of these with remote intelligent field sensors and data transmission systems.

The impact of the system has been material to the performance of the asset. Examples will be given of tangible improvements in performance across the disciplines of surveillance, production engineering and well services. What was found was that critical to the successful deployment of this system was the organizational changes needed to support the new working practices it enabled. The paper will discuss the required Change Management programs.

The success of this project has established without doubt that a "smart" solution integrating intelligent remote devices, communications networks and workflow management software can be successfully deployed on large, mature fields. The deployment process to achieve this has been assimilated and is now being reproduced in many other similar fields across North America. The paper will indicate some of the areas where this combination of technology and supporting change management will be expanded in the future.
Continuous Well Production Flow Monitoring and Surveillance
Authors: Poulisse H. , van Overschee P. , Briers J. , Moncur C. , Goh K. -C.
Published: December 2007

In E &P, from asset managers to front end operations staff, there is a common problem — we are data rich, but information poor. In particular, timely well-by-well production surveillance and allocation often remains a problem. Gathering data, even real time data, from wells and facilities hasn't been an issue, but validating the data and relating this data to individual well production rates in a coherent, consistent and timely manner and then taking prompt action, is a challenge. Traditional routine well testing simply provides a series of snap-shots of a well's performance, which may or may not reflect the production during the intervening period. Errors are typically spread across the wells and reservoirs through a reconciliation process comparing estimated well productions and actual metered sales on a weekly or monthly basis.

This paper describes the development and application of a new tool, FieldWare* PRODUCTION UNIVERSE * (PU)1, which estimates real time well production rates from simple field measurements and provides online reconciliation against bulk measurements and export meters. The novel aspect of the technique is that it uses dynamic, data-driven models to describe the production process, together with a new well test methodology for capturing the data to build the initial models. Well tests include a deliberate disturbance to the production to determine the dynamic characteristics of a well. The models do not require underlying physical or process models, predetermined multiphase flow correlations, compositional data or well/piping/equipment details. This has made the models quick to set-up and easy to maintain.

FieldWare PRODUCTION UNIVERSE is now fully operational and used for well-by-well production surveillance and monitoring at many of Shell's production facilities worldwide, both onshore and offshore. The application of PU has helped increase production through improved monitoring, resolved hydrocarbon allocation problems through real time reconciliation, allowed an increase in time between well tests and reduced travel to field locations.

The availability of real time production data is a key enabler for future smart optimization and intelligent diagnostics. PU is a foundation element for Shell's Smart Fields initiative.
Well-Test Optimization and Automation
Authors: Cramer R. , Moncur C. , Berendschot L.
Published: December 2007

Much can be done to improve the Well Testing through effective use of minimal electronic instrumentation on the well head and the test separator. The purpose of this paper is to describe Shell tools and experiences using the resulting real time data to enable well test optimization and automation.
Optimized Workflow for Designing Complex Wells
Authors: Moreno J. C. , Bradley D. , Gurpinar O. , Richter P. , Hussain A. , Shammari M. , Garni S.
Published: December 2007

Application of multilateral technology, to improve productivity by maximizing reservoir contact, is expected to become a common practice. The prime objective is delineation of reservoirs with fewer wells by accessing additional reserves and accelerating production. Planning such wells requires extensive numerical modeling, which brings simultaneous optimization of well placement, total length and branch configuration. Currently there is no systematic workflow to perform these tasks.

In this paper a streamlined workflow for designing complex wells is presented. Validation of the workflow, which entails evaluation and quantification of the benefits of drilling a complex well, was performed for a Middle East reservoir. Smart well capabilities were also incorporated, aiming to maximize oil recovery through better management of the different contacted areas. The base platform for the workflow was a numerical reservoir simulator that rigorously couples wellbore and reservoir flows. Further optimization was achieved by employing a neural network.

As a result of this investigation, it was demonstrated that well deliverability is strongly influenced by number, length and position of laterals, as well as the characteristics and behavior of the injection waterfront. Consequently, it was possible to identify the best configuration of the well to maximize deliverability, at the same time reducing the number of laterals and optimizing the use of smart control devices that ensures economical feasibility.
Atorvastatin But Not Elocalcitol Increases Sildenafil Responsiveness in Spontaneously Hypertensive Rats by Regulating the RhoA/ROCK Pathway
Authors: Fibbi Benedetta , Morelli Annamaria , Marini Mirca , Zhang Xin‐Hua , Mancina Rosa , Vignozzi Linda , Filippi Sandra , Chavalmane Aravinda , Silvestrini Enrico , Colli Enrico , Adorini Luciano , Vannelli Gabriella Barbara , Maggi Mario
Published: December 2007

ABSTRACT: Spontaneously hypertensive rats (SHR) are characterized by impaired erectile function and overactivity of the procontractile RhoA/Rho‐associated, coiled‐ coil—containing protein kinase (RhoA/ROCK) pathway, as compared with their normotensive counterpart, Wistar‐Kyoto rats. By measuring the intracavernous pressure:mean arterial pressure (ICP:MAP) ratio after electrostimulation of the cavernous nerve, we confirmed these findings and showed that responsiveness to sildenafil (25 mg/kg by oral gavage) also is hampered in SHR. A 2‐week treatment with atorvastatin (5 and 30 mg/kg) improved the sildenafil‐induced ICP:MAP increase and normalized RhoA and ROCK2 overexpression in SHR corpora cavernosa (CC). Conversely, other genes, neuronal nitric oxide synthase (NOS), endothelial NOS, and phosphodiesterase 5, were unaffected. In human fetal smooth muscle cells derived from CC (hfPSMC), atorvastatin inhibited RhoA membrane translocation and ROCK activity, as well as RhoA‐dependent biologic functions like cell migration and cell proliferation. Atorvastatin's effect on migration was rescued in a dose‐dependent manner by geranylgeranyl pyrophosphate, suggesting the involvement of RhoA geranylgeranylation. In hfPSMC, atorvastatin decreased the expression of RhoA‐dependent genes such as ROCK2, desmin, α‐smooth muscle actin, SM22α, and myocardin. In contrast to atorvastatin, elocalcitol, a vitamin D analog that also interferes with RhoA activation in SHR bladder, was unable to restore penile responsiveness to sildenafil. In conclusion, atorvastatin, but not elocalcitol, ameliorates sildenafil‐induced penile erections in SHR, likely by interfering with RhoA/ROCK signaling within the penis.
Y:X Sperm Ratio in Boron‐Exposed Men
Authors: Robbins Wendie A. , Wei Fusheng , Elashoff David A. , Wu Guoping , Xun Lin , Jia Juan
Published: December 2007

ABSTRACT: Several epidemiologic investigations have shown shifts in sex ratios at birth toward females in populations with relatively high boron exposure. To investigate the paternal origin of these shifts, we assayed sperm Y:X ratio in men exposed to a range of environmental and workplace boron. Participants included 63 workers in boron industry: 39 men living in an area of high environmental boron but not employed in boron industry, and 44 controls living in an area of low environmental boron. Total daily boron exposure was calculated as the sum of boron in 24‐hour duplicate food and fluid intakes plus personal air sampling for workplace inhalable dust. Internal dose was measured in blood, urine, and semen. Sperm were analyzed by fluorescence in situ hybridization for Y‐ versus X‐bearing cells. Potential confounders were identified using a questionnaire. Total exposure was correlated with internal dose (Pearson correlation for total exposure and boron in blood = 0.63, P < .0001; semen = 0.80, P < .001; and urine = 0.79, P < .0001). Linear regression of logged boron in biologic fluids on Y:X ratio was significant for blood P = .02, semen P = .0003, and urine P = .005. Additionally, when subjects were categorized by exposure group, decreased Y:X sperm ratio was found for boron workers compared with men in a high boron environment and controls (P < .0001). Exogenous environmental or workplace boron exposures were associated with decreases in Y‐ versus X‐bearing sperm. This may explain earlier findings from us and others showing changes in offspring sex ratios at birth for men exposed to boron.
Ethanol Expansion in the Food versus Fuel Debate: How Will Developing Countries Fare?
Authors: Elobeid Amani , Hart Chad
Published: December 2007

This paper examines the impact of ethanol expansion in the United States, brought about by higher crude oil prices, on agricultural commodity prices. Given the United States's stature as a major producer and exporter of many agricultural commodities, the resulting increase in commodity prices has spillover effects into the global market. Using the price changes estimated within a multi-commodity, multi-country agricultural modeling system, this paper attempts to show how an increase in world commodity prices would affect the costs of food baskets around the world and how higher food costs will impact food security, particularly in developing countries. In general, we find that countries where corn is the major food grain experience larger increases in food basket cost while countries where rice is the major food grain have smaller food basket cost increases. Countries where wheat and/or sorghum are the major food grains fall in between. Consequently, the highest percentage increases are seen in Sub-Saharan Africa and Latin America where food basket costs are estimated to increase by at least 10%. The lowest percentage increases are seen in Southeast Asia, with cost increases of less than 2.5%.
Potential Land Use Implications of a Global Biofuels Industry
Authors: Gurgel Angelo , Reilly John M , Paltsev Sergey
Published: December 2007

In this paper we investigate the potential production and implications of a global biofuels industry. We develop alternative approaches to consistently introduce land as an economic factor input and in physical terms into a computable general equilibrium framework. The approach allows us to parameterize biomass production consistent with agro-engineering information on yields and a "second generation" cellulosic biomass conversion technology. We explicitly model land conversion from natural areas to agricultural use in two different ways: in one approach we introduced a land supply elasticity based on observed land supply responses and in the other approach we considered only the direct cost of conversion. We estimate biofuels production at the end of the century could reach 221 to 267 EJ in a reference scenario and 319 to 368 EJ under a global effort to mitigate greenhouse gas emissions. The version with the land supply elasticity allowed much less conversion of land from natural areas, forcing intensification of production, especially on pasture and grazing land, whereas the pure conversion cost model led to significant deforestation. These different approaches emphasize the importance of somehow reflecting the non-market value of land more fully in the conversion decision. The observed land conversion response we estimate may be a short turn response that does not fully reflect the effect of long run pressure to convert land if rent differentials are sustained over 100 years.
CO Methanation as Alternative Refinement Process for CO Abatement in H2-Rich Gas for PEM Applications
Authors: Galletti Camilla , Specchia Stefania , Saracco Guido , Specchia Vito
Published: December 2007

Theoretically, there are several methods that can be used to remove CO from H2-rich gases. As for the applications of PEM-FCs to vehicles, boats and yachts and residential co-generators, however, the feasible choice may be only between the preferential CO oxidation (CO-PROX) and the selective CO methanation (CO-SMET) because of the limited available spaces and low operating pressures in such application systems. The CO-PROX process has so far been extensively tested since it is somehow reliable to remove CO down to 10 ppmv by raising the O2 consumption unlimitedly. Nonetheless, the technology requires a closely controlled low O2 supply to keep the possibly lowest H2 parallel oxidation and a working temperature window suitably wide for control purposes. This, while making the method costly and complicated, obviously hampers its application to low-power PEM-FCs where very small oxidant flows have to be provided by use of well-refined expensive flow meters, such as mass flow meters. Without any additional reactant required, the CO-SMET can avoid the above-mentioned shortcomings of the CO-PROX application. Furthermore, the CO methanation is less exothermic than the CO and H2 oxidations. Thus, a CO-SMET reactor is inherently more easily controllable than a CO-PROX one. The present work deals with a screening of catalysts for CO abatement via selective methanation. Ru-based catalysts supported on TiO2, ZrO2 and CeO2 were prepared by a conventional impregnation method and CO removal was determined by varying the operating conditions. The obtained results showed good performances of the Ru/ZrO2 and Ru/CeO2 supported catalysts, and also the feasibility and applicability of the CO-SMET process, especially by employing the Ru/CeO2 supported catalyst.
Model of Noise Source for HF Interference Calculation in a Converter Station
Authors: Hao Quanrui , Xu Zheng
Published: December 2007

For high-frequency (HF) interference in an HVDC converter station, the modeling of the noise source which causes interference with the power line carrier (PLC) remains a problem. Based on the profound analysis of the basic principles on which HF noise in PLC band is produced during the commutation process, the equivalent model of the HVDC valve with a snubber circuit is applied to the simulation of the GUI-GUANG HVDC project in PSCAD/EMTDC. Then spectrum plots of the noise source in the frequency domain are obtained by FFT analysis of the voltage waveforms gained from the simulation. Through analyzing the spectrum characteristics of the noise source in various operating modes, the main factors influencing the level of HF noise are found. Furthermore, a modified empirical model used to calculate the level of the noise source is introduced, with particular explanation of the physical quantities used in the model. The spectra of the noise source gained from the modified empirical model and from the simulation are compared with an actual spectrum based on the GUI-GUANG HVDC project. The results show that the modified empirical model can meet the requirement of HF interference calculation.
Chemical Constituents, Antioxidative and Antimicrobial Activities of Essential Oil and Oleoresin of Tailed Pepper (Piper Cubeba L)
Authors: Singh Gurdip , Marimuthu Palanisamy , Heluani Carola S. de , Catalan Cesar A. N.
Published: December 2007

The antimicrobial and antioxidant potentials of hydrodistilled essential oil and oleoresin (obtained using acetone as a solvent) of tailed pepper were carried out by different techniques. The results obtained from antioxidant activity measurements of essential oil and oleoresin against mustard oil were measured for duration of 28 days in terms of peroxide, thiobarbituric acid, total carbonyl and p-anisidine values. The results obtained from butylated hydroxyanisole (BHA) and butylated hydroxytoluene (BHT) was similar to both the oleoresin and essential oil. In addition, the inhibitory action in linoleic acid system was studied by monitoring accumulation of peroxide concentration. The radical scavenging capacity of both essential oil and oleoresin on 2, 2'-diphenyl-1-picrylhydrazyl (DPPH) radical were (71.2%) and (69.77%) respectively at 25 µL/mL. It was relatively lower in comparison with synthetic antioxidants (BHA-96.41%; BHT- 95.91%). The results obtained from reducing power, chelating effect and hydroxyl radical scavenging effect was also supported the antioxidant of essential oil and oleoresin. The tailed pepper essential oil and oleoresin showed 100% mycelial zone inhibition against Penicillium viridicatum at 3000 and 2000 ppm respectively in the poison food method. It is interesting to note that the essential oil revealed 100% clear zone inhibition against Aspergillus flavus at all tested concentrations. The chemical characterization of tailed pepper essential oil by GC and GC-MS resulted in the identification of 44 components accounting for 97.8% of the oil.
Racial and Economic Factors in Attitudes to Immigration
Authors: Dustmann Christian , Preston Ian P
Published: December 2007

In this paper we distinguish between three channels that determine attitudes to further immigration: labour market concerns, welfare concerns, and racial or cultural concerns. Our analysis is based on the British Social Attitudes Survey. A unique feature of the survey is that it includes questions on attitudes towards immigration from different origin countries, with populations differing in ethnic similarity to the resident population. It also contains sets of questions relating directly to the labour market, benefit expenditure and welfare concerns, and racial and cultural prejudice. Based on this unique data source, we specify and estimate a multiple factor model that allows comparison of the relative magnitude of association of attitudes to further immigration with the three channels, as well as comparison in responses across potential immigrant groups of different origin. Our results suggest that, overall, welfare concerns play a more important role in determination of attitudes to further immigration than labour market concerns, with their relative magnitude differing across potential emigration regions and characteristics of the respondent. In addition, we find strong evidence that racial or cultural prejudice is an important component to attitudes towards immigration; however, this is restricted to immigration from countries with ethnically different populations.
Journal Publication Productivity in Academic Physical Therapy Programs in the United States and Puerto Rico From 1998 to 2002
Authors: Richter Randy R , Schlomer Sarah L , Krieger Mary M , Siler William L
Published: December 2007

Background and Purpose

The peer-reviewed journal article is the basic unit by which scholarship is defined. Few studies have examined peer-reviewed publication productivity in academic physical therapy programs. In this study, the publication productivity in academic physical therapy programs in the United States and Puerto Rico from 1998 to 2002 was documented, and publication productivity was examined in the context of selected program characteristics.

Subjects and Methods

A total of 194 programs listed on the Commission on Accreditation in Physical Therapy Education (CAPTE) Web site in the spring of 2004 were examined. The databases were searched for bibliographic citations of journal articles attributed to particular programs. The program characteristics of faculty size, offering of a research doctorate, and listing in the Carnegie Classification of Institutions of Higher Education (Carnegie Classification) were compared with the number of citations.

Results

A total of 169 programs had at least 1 attributed citation, 50.3% of the programs had fewer than 5 citations, and 3% had 44 or more citations. Rankings based on the number of citations changed when adjusted for faculty size. Of the 38 programs offering a research doctoral degree, 16 had 20 or more citations. Five programs with 44 or more citations were all categorized by the Carnegie Classification as doctoral intensive or extensive.

Discussion and Conclusion

A few programs had a large number of attributed bibliographic citations, but the majority of programs had limited publication productivity in the 5 years studied. These results may provide a baseline for studying the effectiveness of the relatively new CAPTE standards mandating scholarship by physical therapy faculty over time and the impact of the Doctor of Physical Therapy degree on research in physical therapy.
Multidimensional Motor Sequence Learning Is Impaired in Older But Not Younger or Middle-Aged Adults
Authors: Boyd Lara A , Vidoni Eric D , Siengsukon Catherine F
Published: December 2007

Background and Purpose

The purpose of this study was to identify which characteristics of a multidimensional sequence containing motor, spatial, and temporal elements would be most salient for motor sequence learning and whether age might differentially affect this learning.

Subjects

Younger (n=11, mean age=26.0 years), middle-aged (n=13, mean age=50.7 years), and older (n=11, mean age=77.5 years) adults who were neurologically intact participated in the study.

Methods

Participants practiced a sequencing task with repeated motor, spatial, and temporal dimensions for 2 days; on a separate third day, participants completed retention and interference tests designed to assess sequence learning and which elements of the sequence were learned. The mean median response time for each block of responses was used to assess motor sequence learning.

Results

Younger and middle-aged adults demonstrated sequence-specific motor learning at retention testing via faster response times for repeated sequences than random sequences; both of these groups showed interference for the motor dimension. In contrast, older adults demonstrated nonspecific learning (ie, similar improvements in response time for both random and repeated sequences). These findings were shown by a lack of difference between random and repeated sequence performance in the older adult group both at retention testing and during interference tests.

Conclusion and Discussion

Our data suggest that, when younger and middle-aged adults practice sequences containing multiple dimensions of movement, the motor element is most important for motor learning. The absence of sequence-specific change demonstrated by an older adult group that was healthy suggests an age-related impairment in motor learning that may have profound implications for rehabilitation.
Movement Training Advances the Emergence of Reaching in Infants Born at Less Than 33 Weeks of Gestational Age: A Randomized Clinical Trial
Authors: Heathcock Jill C , Lobo Michele , Galloway James C (Cole)
Published: December 2007

Background and Purpose

This study had 2 purposes: (1) to compare the emergence of reaching in infants born full-term and infants born at less than 33 weeks of gestational age and (2) to evaluate the effectiveness of a movement training program on the emergence of reaching in this preterm population.

Participants

Twenty-six infants born at less than 33 weeks of gestational age and with a birth weight less than 2,500 g were randomly assigned to receive 20 minutes of daily movement training (PT-M group) or daily social training (PT-S group) and were compared with 13 infants born full-term (FT-S group).

Methods

Reaching and hand-object interactions were tested every other week for 8 weeks. At each visit, infants were allowed six 30-second opportunities to contact a midline toy.

Results

The FT-S and PT-M groups reached earlier and more consistently than the PT-S group. Specifically, the subjects in the FT-S group contacted the toy for longer durations and with an open, ventral surface of their hand. The PT-M group demonstrated increases in the number of hand-object contacts, the number of consistent reaches, and the percentage of time interacting with the toy and the surface of hand-object contact.

Discussion and Conclusion

This project demonstrates that there are early gross motor skill differences in infants born at less than 33 weeks of gestational age. A caregiver-based daily training program, however, is effective at lessening some, but not all, of these differences over the short term.
Biomaterials for Tissue Engineering
Authors: Eisenbarth E.
Published: December 2007

Tissue engineering needs a biomaterial as a framework for single cells to build a vital and well functioning tissue. A future challenge is to modify biomaterials used this purpose in a way that they imitate in their composition and/or structure the native and physiological conditions for the tissue specific cells. This review gives a survey about types of the used biomaterials, processing techniques and biomimetic aspects.
Novel paclitaxel‐eluting, biodegradable polymer coated stent in the treatment of de novo coronary lesions: A prospective multicenter registry
Authors: Buszman Paweł , Trznadel Stanisław , Milewski Krzysztof , Rzeźniczak Janusz , Przewłocki Tadeusz , Kośmider Maciej , Wójcik Jaroslaw , Janczak Jacek , Żurakowski Aleksander , Kondys Marek , Król Marek , Kinasz Leszek , Jaklik Andrzej , Rzeszutko Łukasz , Kałuża Grzegorz L. , Kiesz Stephan , Gil Robert
Published: December 2007

Objectives: The purpose of the present study was to evaluate the efficacy and safety of a biodegradable polymer coated, paclitaxel eluting stent (Luc‐Chopin2) based on 9‐months angiographic and 12‐months clinical follow‐up results. Background: First‐generation drug‐eluting stents utilize nonbioabsorbable polymeric coatings, whose persistent presence in the arterial wall may negatively affect long‐term outcomes. Bioabsorbable coatings with a degradation period matched to that of the drug elution may be a better alternative, clinically and economically. Methods: We conducted a prospective, multicenter first‐in‐man registry of a novel, locally developed, bioabsorbable‐coated, paclitaxel‐eluting coronary stent in 116 patients with single‐lesion de novo coronary disease. Results: Major adverse cardiac events occurred in 7.8% patients within 12 months. There were no late thrombotic events, death, stroke, or surgical revascularization in that period. There were two myocardial infarctions, one related to recent subacute stent thrombosis and another associated with restenosis. By 12 months, target vessel revascularization was performed in 7.8%; 2.9% were ischemia‐driven and the rest were mandated at 9 months in accordance with a control angiography protocol. Core‐lab assessed binary in‐stent restenosis (≥50% DS) was noted in 11.9% patients and mean late loss was 0.46 ± 0.47 mm. Conclusions: This first‐in‐man experience obtained in a multicenter registry of real‐world de novo lesions (almost half of lesions were class B2 or C by AHA classification) showed a favorable safety profile and acceptable efficacy through 12 months. Randomized comparison with a benchmark nonbioabsorbable polymer coated paclitaxel eluting stent should be undertaken to validate this initial positive experience. © 2008 Wiley‐Liss, Inc.
Early and mid‐term results with the growth stent—A possible concept for transcatheter treatment of aortic coarctation from infancy to adulthood by stent implantation?
Authors: Ewert Peter , Peters Bjoern , Nagdyman Nicole , Miera Oliver , Kühne Titus , Berger Felix
Published: December 2007

Aims: Evaluation of the Growth Stent—a stent consisting of two stent halves connected by reabsorbable sutures—for the treatment of aortic coarctation in infants. Methods and Results: Surveillance study of 13 Growth Stents implanted in 12 patients aged 1–15 months (median 5 months). Body weight ranged from 3.4–12.8 kg (median 5.4 kg). Eight patients suffered from aortic (re‐)coarctation, four of them from stenosis of the aortic anastomosis after a Norwood I procedure. The follow‐up period was 24 months (11–51 months). Pressure gradients immediately after stent implantation decreased from 30 mm Hg (range 20–50 mm Hg) to 8 mm Hg (range 0–15 mm Hg). Five patients had one (3 pts) or two (2 pts) balloon dilations 3–28 months (median 12 months) after Growth Stent implantation. The median pressure gradient decreased from 25 mm Hg (range 15–30 mm Hg) to 15 mm Hg (range 5–25 mm Hg). Six patients received a large stent after 19–34 months. Median body weight was 11.8 kg (9.4–15 kg). Conclusions: The Growth Stent is suitable for the acute treatment of aortic coarctation in infants and can be overstented later on—if necessary—with a larger stent without causing restriction. © 2008 Wiley‐Liss, Inc.
Comparative rheology of low‐ and iso‐osmolarity contrast agents at different temperatures
Authors: Brunette Jean , Mongrain Rosaire , Rodés‐Cabau Josep , Larose Éric , Leask Richard , Bertrand Olivier F.
Published: December 2007

Background: Several contrast media (CM) are used for diagnostic angiography and coronary percutaneous interventions. Catheter miniaturization allows performance of most diagnostic studies using 4–5 F catheters and interventions using 5–6 F catheters. As a result of catheter lumen downsizing and viscosity of CM, the operators are sometimes required to forcefully inject to produce adequate images. Methods and Results: The aim of the study is to perform a comparative rheology analysis between three different commonly used CM: iso‐osmolar, nonionic iodixanol, Visipaque®, (GE Healthcare); low‐osmolar, nonionic ioversol, Optiray®; and low‐osmolar, ionic ioxaglate, Hexabrix®, (Tyco Healthcare, US). The viscosity was experimentally assessed for temperature varying from 14 to 40°C. To reproduce clinical use, an experimental set‐up was used and the pressure developed to inject CM was evaluated at different temperatures and compared between the three CM. All three agents demonstrated a nonlinear inverse relationship between temperature and viscosity. At 14°C iodixanol showed a twofold increase in viscosity compared with ioversol and ioxaglate. At 40°C, the difference was reduced to 27%. At room temperature (20°C), the difference in pressure needed to inject CM was 10% between iodixanol and ioxaglate and 6% between iodixanol and ioversol. As the temperatures increased, the differences in pressure became less important, becoming negligible (1%) at 37°C. Conclusion: The viscosity of the iso‐osmolar nonionic contrast agent iodixanol showed a stronger dependence on temperature compared with ioversol and ioxaglate. The impact of differences in viscosity and pressure to inject between CM were minimized at 37°C. This emphasizes the importance of temperature control when using current low‐osmolar CM and iso‐osmolar CM with smaller sized catheters. © 2008 Wiley‐Liss, Inc.
Small‐Molecule based Delivery Systems for Alkylating Antineoplastic Compounds
Authors: Bielawski Krzysztof , Bielawska Anna
Published: December 2007

Alkylating agents are a major class of anticancer drugs for the treatment of various cancers including hematological malignancies. Targeting alkylating moieties to DNA by attachment of a DNA minor groove binding carrier such as distamycin, netropsin, or Hoechst 33252 reduces the loss of active drug due to reaction with other cell components and makes it possible to direct the alkylation both sequence specifically and regiospecifically. We reported the synthesis and structure–activity studies of amidine analogues of alkylating antineoplastic compounds, which appeared to be a new class of cytotoxic minor groove binders and topoisomerase II inhibitors. Another approach to overcome the toxicity of alkylating agents to normal tissue is to construct a prodrug with lower hydrophobicity and cytotoxicity but is preferentially activated in cancer cells. Overexpression of prolidase in some neoplastic cells suggests that the proline analogue of alkylating agents may serve as a prolidase convertible prodrugs. We have compared several aspects of pharmacological actions of proline analogues of chlorambucil and melphalan in breast cancer cells. The results suggest that prolidase could serve as a target enzyme for the selective action of anticancer agents.
Understanding the impact of breast reconstruction on the surgical decision‐making process for breast cancer
Authors: Alderman Amy K. , Hawley Sarah T. , Waljee Jennifer , Mujahid Mahasin , Morrow Monica , Katz Steven J.
Published: December 2007

BACKGROUND.

Reconstruction is rarely incorporated into the decision‐making process for surgical breast cancer treatment. We examined the importance of knowing about reconstruction to patients' surgical decision‐making for breast cancer.

METHODS.

We surveyed women aged ≤79 years with breast cancer (N = 1844) who were reported to the Detroit and Los Angeles Surveillance, Epidemiology, and End Results (SEER) cancer registries (response rate, 77.4%). The dependent variables were 1) patients' report of having a discussion about breast reconstruction with their general surgeon (yes/no), 2) whether or not this discussion had an impact on their willingness to be treated with a mastectomy (yes/no), and 3) whether the patient received a mastectomy (yes/no). The independent variables included age, race, education, tumor size, tumor behavior, and presence of comorbidities. Chi‐square, Student t test, and logistic regression were used for analyses.

RESULTS.

Only 33% of patients had a general surgeon discuss breast reconstruction with them during the surgical decision‐making process for their cancer. Surgeons were significantly more likely to have this discussion with younger, more educated patients with larger tumors. Knowing about reconstructive options significantly increased patients' willingness to consider a mastectomy (OR, 2.06; P <.01). In addition, this discussion influenced surgical treatment. Patients who discussed reconstruction with their general surgeon were 4 times more likely to receive a mastectomy compared with those who did not (OR, 4.48; P < .01).

CONCLUSIONS.

Most general surgeons do not discuss reconstruction with their breast cancer patients before surgical treatment. When it occurs, this discussion significantly impacts women's treatment choice, making many more likely to choose mastectomy. This highlights the importance of multidisciplinary care models to facilitate an informed surgical treatment decision‐making process. Cancer 2008. © 2007 American Cancer Society.
The impact of prostate‐specific antigen level at diagnosis on the relative survival of 28,531 men with localized carcinoma of the prostate
Authors: Sandblom Gabriel , Ladjevardi Sam , Garmo Hans , Varenhorst Eberhard
Published: December 2007

BACKGROUND.

To evaluate the predictive value of prostate‐specific antigen (PSA) in a population‐based cohort, the authors analyzed relative survival in all men with localized prostate cancer who were registered in the Swedish National Prostate Cancer Register (NPCR) from 1996 to 2005.

METHODS.

All men aged <75 years with localized tumors were identified in the NPCR. A Poisson regression analysis was performed using observed death as response and the expected death rate as offset. The expected and observed numbers of survivors were calculated with stratification for PSA level and 3 categories of tumor differentiation (Gleason score 2–6, 7, and 8–10). The regression model included PSA as linear splines with a breakpoint at a PSA level of 4 ng/mL and with tumor differentiation as a categoric variable.

RESULTS.

The Poisson regression analysis indicated a U‐shaped curve for all 3 groups, with a negative correlation between PSA and relative survival in men with PSA levels <4 ng/mL and a positive correlation for men with PSA levels >4 ng/mL. The correlation was significant for all 3 groups, but the negative correlation between PSA and relative survival was significantly more pronounced in the group with Gleason scores from 8 to 10 than in the other 2 Gleason score groups.

CONCLUSIONS.

The demonstration of an inverse correlation between PSA level and relative survival in the group of men with PSA levels <4 ng/mL indicated the presence of a small but clinically important subgroup with undifferentiated tumors who have cells that have lost the ability to secrete PSA. This group should be taken into consideration when deciding on treatment and when choosing a cutoff level in PSA screening programs. Cancer 2008. © 2007 American Cancer Society.
A Crossed Molecular Beam Study on the Reaction of Boron Atoms with Methylacetylene and Partially Deuterated Methylacetylene
Authors: Zhang Fangtong , Kao Chih Hao , Chang Agnes H. H. , Gu Xibin , Guo Ying , Kaiser Ralf I.
Published: December 2007

The reactions of ground‐state boron atoms, B(2Pj), with methylacetylene, CH3CCH(X1A1), and its [D3]‐substituted isotopomer, CD3CCH(X1A1), are studied under single collision conditions using the crossed molecular beam technique at collision energies of 21.6 and 21.9 kJ mol−1, respectively. Utilizing the CD3CCH reactant, detailed information on the dynamics is obtained. The reaction followed indirect scattering dynamics and proceeded through at least two reaction channels via atomic deuterium and hydrogen atom elimination pathways leading eventually to two isotopomers, that is, theC2vsymmetric D2CCCBH(X1A1) and D2CCCBD(X1A1) structures via statistical and non‐statistical reaction pathways, respectively.
Head involution in Drosophila: Genetic and morphogenetic connections to dorsal closure
Authors: VanHook Annalisa , Letsou Anthea
Published: December 2007

Dorsal closure and head involution are complex morphogenetic processes that occur nearly simultaneously, midway through Drosophila embryonic development. While dorsal closure has been studied extensively in terms of both its morphology and genetics, head involution has not been described comprehensively. A thorough review of the literature nonetheless reveals considerable information regarding the genetic components of head involution. In several instances, authors have made explicit references to head involution in regard to mutant phenotypes; in others, we have made this connection. Here we collect, catalogue, and discuss published head involution studies. In considering and integrating the data, an enhanced appreciation of the molecular mechanisms underlying head involution and its molecular kinship with dorsal closure has emerged. Developmental Dynamics 237:28–38, 2008. © 2007 Wiley‐Liss, Inc.
Functional analysis of swallowing outcomes after supracricoid partial laryngectomy
Authors: Lewin Jan S. , Hutcheson Katherine A. , Barringer Denise A. , May Annette H. , Roberts Dianna B. , Holsinger F. Christopher , Diaz Eduardo M.
Published: December 2007

Background.

In this study, we analyzed swallowing recovery after supracricoid partial laryngectomy (SCPL).

Methods.

We retrospectively reviewed 27 patients treated with SCPL (September 1997 to March 2005). We evaluated recovery course, nutritional outcomes, and swallowing using objective analysis. Modified barium swallow (MBS) study results identified swallowing physiology and therapeutic effectiveness.

Results.

Average length of hospitalization was 7.7 ± 9.2 days; time to decannulation was 5.3 ± 8.2 weeks. The most common complications included pneumonia and subcutaneous emphysema (26%). Twenty‐two patients had MBS studies, in which initially, all patients aspirated due to neoglottic incompetency, and impaired base of tongue and laryngeal movements. Although aspiration rates did not change significantly over time, use of appropriately selected swallowing strategies effectively protected the airway (p = .0365). Ultimately, 81% of patients returned to complete oral intake with median tube removal at 9.4 weeks.

Conclusion.

SCPL produces severe dysphagia initially. Our findings suggest that objective swallowing assessment is important for return to oral nutrition after SCPL. © 2007 Wiley Periodicals, Inc. Head Neck, 2008
Using qualitative methods to assess student trajectories and college impact
Authors: Harper Shaun R.
Published: December 2007

Understanding how students navigate their ways to and through higher education could be instructive for those seeking to wisely invest institutional and public resources, foster supportive environments for student development, and cultivate worthwhile partnerships to improve access and enhance student success.
Using qualitative methods to assess student learning in higher education
Authors: Contreras‐McGavin Melissa , Kezar Adrianna J.
Published: December 2007

In an era of increased accountability in higher education, stronger and more compelling evidence of what and how students learn is needed. Ways in which qualitative approaches can be used to assess student learning are described in this chapter.
Structural hierarchy of biomimetic materials for tissue engineered vascular and orthopedic grafts
Authors: Lekakou C. , Lamprou D. , Vidyarthi U. , Karopoulou E. , Zhdan P.
Published: December 2007

Gelatine gels and gelatine/elastin gels have been prepared to be used in tissue engineered vascular grafts. Optical microscopy and atomic force microscopy (AFM) revealed that the gelatine formed nanofibrils as in soft collagen tissues. The gelatine/elastin gels were nanocomposites with flat elastin nanodomains embedded in the gelatine matrix mimicking the structure of the tunica media in arteries. Gelatine/“hydroxyapatite” (HA) nanocomposites were prepared with the in situ production of “HA” in solution. AFM revealed “HA” solid nanoparticles of about 20 nm size embedded in the gelatine matrix, which formed a hierarchical structure similar to that of the collagen matrix in bone. The application of amagnetic field of 9.4 T resulted in the elongation and orientation of gelatine particles and orientation of gelatine microfibrils in a direction perpendicular to that of the magnetic field. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2008
Comparison of ciprofloxacin hydrochloride‐loaded protein, lipid, and chitosan nanoparticles for drug delivery
Authors: Jain Dharmendra , Banerjee R.
Published: December 2007

The aim of the present study was to develop single dose delivery systems based on nanotechnology for prolonged antibiotic release in a controlled manner. Five different drug–carrier ratios of ciprofloxacin hydrochloride‐loaded nanoparticles of albumin, gelatin, chitosan (CS), and lipid [solid lipid nanoparticles (SLNs)] were prepared and characterized. Average particle size was found to be in the range of 73 ± 2 to 98 ± 44 nm for SLNs, 140 ± 7 to 175 ± 24 nm for albumin nanoparticles, 143 ± 18 to 184 ± 27 nm for gelatin nanoparticles, and 247 ± 48 to 322 ± 52 nm for CS nanoparticles. A drug‐to‐carrier ratio of 0.5:1 was preferred for CS nanoparticles having zeta potential of >20 mV and drug encapsulation of 35.01% ± 2.66%. Similarly, 0.6:1 ratio was preferred for albumin nanoparticles with zeta potential >16 mV and drug encapsulation 48.20% ± 3.01%. Zeta potentials of gelatin nanoparticles loaded with ciprofloxacin suggested that they were unstable and prone to flocculation. SLN with 0.25:1 drug carrier ratio showed 38.71% ± 2.38% drug entrapment and −28 ± 1 mV surface charge. All the nanoparticles showed sustained drug release avoiding “burst effect” of the free drugs for up to 120 h for albumin nanoparticles, 96 h for CS and gelatin nanoparticles, and 80 h for SLNs. The drug release profiles followed Higuchi model. Results suggest that CS nanoparticles and SLNs can act as promising carriers for sustained ciprofloxacin release in infective conditions. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2008