bluuebunny/crossref_metadata_2025 huggingface dataset:
A influência do uso do "clamp" ou braçadeira no acúmulo de coágulos em drenos pleurais tubulares
Authors: Lima Alexandre Garcia de , Rocha Elen Renate Figueira , Seabra José Cláudio Teixeira , Mussi Ricardo Kalaf , Santos José Geraldo dos , Contrera Toro Ivan Felizardo
Published: May 2008

OBJETIVO: Conduziu-se este estudo prospectivo a fim de avaliar-se a influência do uso da braçadeira sobre o acúmulo de coágulos dentro dos drenos pleurais. MÉTODO: Os drenos pleurais foram pesados logo após sua retirada, lavados e secados e pesados novamente. A diferença entre a primeira e a segunda pesagem foi admitida como a quantidade de coágulos acumulada. RESULTADOS: Houve maior acúmulo de coágulo nos drenos temporariamente obstruídos por braçadeira em relação àqueles não obstruídos. CONCLUSÃO: Notou-se, neste estudo, maior acúmulo de coágulo dentro de drenos pleurais obstruídos, mesmo que intermitentemente, o que pode levar ao mau funcionamento de todo o sistema de drenagem. A discussão sobre o correto uso dos drenos pleurais deve ser constante e fazer parte de programas de educação continuada para médicos e enfermagem, a fim de que este sistema, amplamente utilizado e altamente eficiente, seja otimizado.
Epidemiologia do traumatismo da coluna vertebral
Authors: Campos Marcelo Ferraz de , Ribeiro André Tosta , Listik Sérgio , Pereira Clemente Augusto de Brito , Andrade Sobrinho Jozias de , Rapoport Abrão
Published: May 2008

OBJETIVO: Avaliação epidemiológica retrospectiva de 100 casos de traumatismo da coluna vertebral. MÉTODO: Estudo transversal de dados colhidos por levantamento de prontuário, segundo protocolo de decodificação local. RESULTADOS: Predomínio etário de 20 a 40 anos em 64% dos casos; sexo masculino em 86%; segmento toracolombar mais comumente atingido 64% e 36% para o segmento cervical; principais causas foram às quedas em 40%, seguidas de acidentes automobilísticos em 25% e quedas da laje 23%. A prevalência dos ferimentos por arma de fogo foi de 7%, mergulho em águas rasas 3% e agressões 2%. Houve análise complementar com cruzamentos entre idade, sexo, causa e segmento da coluna vertebral acometido, observando que o segmento cervical teve grande predomínio nas mulheres em relação aos homens em 85,7% X 14,3%. CONCLUSÃO: O traumatismo da coluna vertebral ocorreu predominantemente em homens entre 20 e 40 anos e o segmento cervical foi o mais acometido nas mulheres em relação aos homens na proporção de 6:1.
Uso de mutações induzidas e cruzamentos recíprocos no incremento da variabilidade genética para o caráter ciclo vegetativo em triticale
Authors: Pandini Fábio , Carvalho Fernando Irajá Felix de , Barbosa Neto José Fernandes
Published: May 2008

O triticale, por ser uma espécie recente e desenvolvida artificialmente, possui uma estreita base genética. O estudo de mecanismos que contribuem para o incremento da variabilidade genética é de grande importância para o melhoramento do triticale e na expansão do seu cultivo. O objetivo deste trabalho foi comparar a eficiência de diferentes métodos para ampliar a variabilidade genética do caráter ciclo vegetativo em triticale. Cruzamentos recíprocos e mutações induzidas pela radiação gama, nas doses de 0, 5, 10, 20, 40 kR foram testados nas cultivares BR4 e EMBRAPA18 de triticale. Os resultados obtidos revelaram um acréscimo do ciclo vegetativo para a maioria dos tratamentos. Houve incrementos significativos nas variâncias para ambas as cultivares nas duas gerações estudadas. Houve alterações nas médias e distribuições de freqüência na maioria dos tratamentos. As maiores alterações ocorridas nas variâncias sugerem que um grande número de genes de pequeno efeito foram atingidos, incrementando as classes genotípicas. Embora a recombinação e a segregação de genes tenha sido superior para o incremento do ciclo, classes genotípicas com menor ciclo foram observadas, principalmente para o tratamento 40 kR, sendo viável a seleção de indíviduos com maior precocidade. Os resultados indicam a possibilidade do uso destas técnicas para ampliar a variabilidade genética do caráter ciclo vegetativo, aumentando a probabilidade de êxito na seleção.
Lesões extra-renais de uremia em 72 cães
Authors: Dantas Antônio Flávio Medeiros , Kommers Glaucia Denise
Published: May 2008

Entre 1986 e 1995 foram diagnosticados 72 casos (4,43%) de uremia de um total de 1.623 cães necropsiados no setor de Patologia Veterinária da Universidade Federal de Santa Maria - RS. Sinais clínicos de uremia foram descritos em 58 cães (80,55%), com predomínio de vômito, anorexia, diarréia e apatia. As lesões extra-renais de uremia foram mais evidentes, em ordem decrescente, nos sistemas digestivo, respiratório, cardiovascular, endócrino e ósseo. As lesões mais freqüentes foram gastropatia urêmica (79,16%), pneumopatia urêmica (49,27%) e endocardite mural do átrio esquerdo associada à arteriopatia degenerativa no miocárdio (34,72%). Em 70 casos a uremia era de origem renal, correspondendo a 16,27% de 430 cães com lesões renais primárias. Dois cães (14,28%) desenvolveram uremia de origem pós-renal dentre 14 cães que apresentaram obstrução ao fluxo urinário. Nenhum caso de uremia de origem pré-renal foi diagnosticado. As lesões renais desencadeadoras de uremia foram glomerulonefrite, nefrose tubular aguda, nefrite intersticial, infarto, cistadenocarcinoma bilateral e amiloidose. A idade dos cães afetados variou entre 2 meses e 12 anos sendo as lesões agudas e subagudas mais freqüentes em animais de até 5 anos e as crônicas em cães entre 6 e 12 anos.
Avaliação de diferentes fontes protéicas sobre o desempenho inicial de larvas do jundiá Rhamdia quelen
Authors: Piaia Rosamari , Radünz Neto João
Published: May 2008

O presente estudo foi realizado com o objetivo de avaliar o efeito de diferentes fontes protéicas sobre a sobrevivência e crescimento de larvas de Rhamdia quelen durante as três primeiras semanas de vida. Utilizou-se 3000 larvas distribuídas em 15 grupos, estocadas em condições controladas de cultivo, em um sistema de criação com reutilização de água, termoregulada. As rações testadas eram isoprotéicas com 35% de PB (proteína bruta) e níveis energéticos variando entre 3075 e 3286kcal ED/kg, formuladas com fontes de origem animal, vegetal e pó de levedura Saccharomyces cerevisae. Agranulometria dos alimentos testados foi de 100 a 200mi, 200 a 400mi e 400 a 600mi para as três semanas experimentais, respectivamente. A distribuição do alimento foi feita a vontade entre 8 e 20 horas. No final deste experimento o tratamento T1, contendo figado bovino e levedura, resultou na maior taxa de sobrevivencia (61%) apresentando diferença altamente significativa em relação aos demais tratamentos. Os tratamentos 2 (soja, levedura), 3 (soja, figado bovino), 4 (soja, milho) e 5 (soja, carne, milho) não diferiram significativamente entre si, apresentando baixas taxas de sobrevivência (1,17 a 10,19%). OT1 apresentou o maior comprimento total aos 21 dias, com media individual de 16,46mm, diferindo significativamente dos demais tratamentos. Nestas condições conclui-se que o pó de levedura juntamente com o fígado bovino em rações, proporcionou o melhor desempenho de larvas de jundiá Rhamdia quelen.
Inquéritos domiciliares de saúde: potencialidades e desafios
Authors: Barros Marilisa Berti de Azevedo
Published: May 2008

É apresentada uma síntese do desenvolvimento das medidas de estado de saúde de populações e do reconhecimento da necessidade de inquéritos populacionais periódicos para a geração dos novos indicadores. Traça-se um breve histórico sobre o desenvolvimento dos inquéritos, apontando conjunturas favoráveis no Brasil para o estabelecimento de uma matriz de diferentes modalidades de inquéritos que passem a integrar de forma consistente o sistema de informação em saúde do país. Destacam-se algumas questões metodológicas relativas aos inquéritos e aponta-se o acúmulo de investimento já feito no país em validação e avaliação de instrumentos e escalas e em desenhos amostrais, entre outros aspectos. É enfatizado que a monitorização da equidade em saúde deve ser uma atribuição central dos inquéritos nacionais, considerando o patamar prevalente de concentração da renda, o que implica um conjunto de definições e escolhas de variáveis e indicadores. Ressalta-se que as linhas de pesquisa relativas aos inquéritos e à sua aplicação na análise das desigualdades em saúde podem constituir espaços significativos para o desenvolvimento de teorias epidemiológicas e de uma prática afinada com o campo da Saúde Coletiva.
Pesquisa Mundial de Saúde: aspectos metodológicos e articulação com a Organização Mundial da Saúde
Authors: Szwarcwald Célia Landmann , Viacava Francisco
Published: May 2008

No ano 2000, o Relatório da Organização Mundial de Saúde (OMS) foi dedicado à proposição de uma metodologia para a avaliação de desempenho dos sistemas de saúde dos países membros. O Relatório 2000 trouxe à agenda da OMS o comprometimento com os objetivos louváveis de avaliação dos sistemas de saúde, monitoramento das desigualdades em saúde e alcance da equidade no financiamento da saúde. Entretanto, o instrumental utilizado foi exposto a inúmeras críticas, tanto de cunho metodológico como conceitual. Como parte deste processo, para suprir informações sobre o estado de saúde das populações, a OMS propôs a elaboração da Pesquisa Mundial de Saúde (PMS) em vários países membros. No Brasil, a PMS foi conduzida no ano de 2003, e objetivou estabelecer parâmetros consistentes para avaliar o estado de saúde da população e a assistência prestada de acordo com as expectativas da população usuária, além de mensurar as desigualdades socioeconômicas em saúde. O inquérito foi realizado em 5000 indivíduos com 18 anos e mais de idade, em âmbito nacional. A amostragem foi realizada em três estágios. No primeiro, foram selecionados 250 setores censitários, com probabilidade proporcional ao tamanho. Em cada setor, foram selecionados 20 domicílios, por amostragem inversa. Em cada domicílio, um morador adulto foi selecionado com eqüiprobabilidade. O questionário modular, originalmente desenvolvido pela OMS, foi adaptado para se adequar às características do nosso meio. Nesse artigo, são descritos os aspectos metodológicos da pesquisa e o processo de articulação com a Organização Mundial da Saúde para a condução da PMS no Brasil.
Anuros da Reserva Rio das Pedras, Mangaratiba, RJ, Brasil
Authors: Carvalho-e-Silva Ana Maria Telles de , Silva Guilherme Ramos da , Carvalho-e-Silva Sergio Potsch de
Published: May 2008

Um estudo de composição de fauna foi realizado em um reduto de Mata Atlântica na região sul Fluminense, município de Mangaratiba, RJ, no período de maio de 1997 a setembro de 2006. As coletas foram feitas mensalmente nos cinco primeiros anos e bimensalmente nos outros cinco anos, totalizando 82 excursões. As visitas tiveram duração média de duas noites, com uma equipe de quatro pessoas, utilizando a metodologia de busca ativa visual e auditiva. Ao todo foram registradas para a região quarenta e uma espécies de vinte e um gêneros, distribuídos em nove famílias: Amphignathodontidae (três), Brachycephalidae (seis), Bufonidae (dois), Centrolenidae (um), Cyclorhamphidae (dois), Hylidae (21), Hylodidae (dois), Leptodactylidae (três) e Microhylidae (um). As espécies foram relacionadas aos diversos micro-ambientes de reprodução encontrados na Reserva Rio das Pedras (ReRP) e foram feitas considerações sobre seu estado de conservação. A distribuição geográfica e a variação altitudinal de Gastrotheca albolineata foram ampliadas. Proceratophrys appendiculata e Bokermannohyla circumdata tiveram também sua variação altitudinal ampliada. Scinax angrensis e Aplastodiscus eugenioi foram incluídas na lista de anfíbios do estado do Rio de Janeiro. A anurofauna da ReRP representa 25% do total de espécies de anuros do estado do Rio de Janeiro, contendo uma espécie ameaçada de extinção na categoria " em perigo" (EN), uma " quase ameaçada" (NT) e outra com distribuição restrita. O número de espécies foi considerado expressivo quando comparado com outras áreas de Mata Atlântica do Estado de São Paulo.
The Case for Autoimmunity in the Etiology of Schizophrenia
Authors: Goldsmith Carroll‐Ann W. , Rogers Donald P.
Published: May 2008

The treatment of schizophrenia has frustrated clinicians for over 50 years. Despite advances in neurotransmitter identification and the development of drugs targeting these transmitters, total remission of the disease is not always achieved. Potential etiologies other than neurotransmitter dysfunction merit consideration. One intriguing concept is the possible contribution of autoimmunity in patients with the disease. This breakdown of self‐tolerance has been implicated in patients with other chronic diseases, such as type 1 diabetes mellitus and myasthenia gravis. The literature on autoimmunity as a possible mechanism in the pathogenesis of schizophrenia can be conflicting, but there is a substantial amount of circumstantial, although not conclusive, evidence of immune dysfunction in patients with schizophrenia.
Corticosteroid receptors involved in stress regulation in common carp, Cyprinus carpio
Authors: Stolte Ellen H , de Mazon Aurélia F , Leon-Koosterziel Karen M , Jesiak Maria , Bury Nic R , Sturm Armin , Savelkoul Huub F J , van Kemenade B M Lidy Verburg , Flik Gert
Published: May 2008

In higher vertebrates, mineralo- (aldosterone) and glucocorticoids (cortisol/corticosterone) exert their multiple actions via specific transcription factors, glucocorticoid (GR) and mineralocorticoid (MR) receptors. Teleostean fishes lack aldosterone and mineral regulatory processes seem under dominant control by cortisol. Despite the absence of the classical mineralocorticoid aldosterone, teleostean fishes do have an MR with cortisol and possibly 11-deoxycorticosterone (DOC) (as alternative for aldosterone) as predominant ligands. We studied corticoid receptors in common carp (Cyprinus carpio L). Through homology cloning and bioinformatic analysis, we found duplicated GR genes and a single MR gene. The GR genes likely result from a major genomic duplication event in the teleostean lineage; we propose that the gene for a second MR was lost. Transactivation studies show that the carp GRs and MR have comparable affinity for cortisol; the MR has significantly higher sensitivity to DOC, and this favours a role for DOC as MR ligand in fish physiology. mRNA of the GRs and the MR is expressed in forebrain (in pallial areas homologous to mammalian hippocampus), corticotrophin-releasing hormone (CRH) cells in the pre-optic nucleus (NPO) and pituitary pars distalis ACTH cells, three key neural/endocrine components of the stress axis. After exposure to prolonged and strong (not to mild acute) stressors, mRNA levels of both GRs and MR become down-regulated in the brain, but not in the NPO CRH cells or pituitary ACTH cells. Our data predicts a function in stress physiology for all CRs and suggest telencephalon as a first line cortisol target in stress.
Calibration of resistance of shear connectors in troughs of profiled sheeting
Authors: Johnson R. P.
Published: May 2008

Where a composite floor slab is supported on a composite beam of steel and concrete, shear connection is provided by studs in troughs of the sheeting. The resistance of these studs to longitudinal shear depends on over 20 parameters, of which 15 appear in the mechanical models for shear resistance of Johnson and Yuan, published in 1998. These models have been revised. The mean of 213 ratios of test/predicted shear resistance is now 1·03. For six layouts of studs, the variation of the ratios is lower than that of ratios predicted using the design methods of Eurocode 4. The Eurocode provides the intended margin of safety, based on push testing. Resistances to BS 5950-3-1 are on average 19% higher, but experience with it has been satisfactory. This paradox is discussed, with reference to tests on beams and to current anxiety about slip capacity.
Stiffness identification of framed models under controlled damage
Authors: Garcés F. , Genatios C. , García P. , Lafuente M. , Mebarki A.
Published: May 2008

This paper presents an original method of estimating the location and severity of damage in a framed building based on experimental measurements of its fundamental vibration modes. Two procedures are presented: one usable when the mass matrix is known and the other usable when the mass matrix is unknown. Both require prior knowledge of the fundamental vibration modes of the undamaged structure, either through experimental tests or through an accurate analytical model. An important advantage of this method is that very few experimental data are needed. To study the accuracy of damage identification under noisy conditions, numerical simulations of a multi-storey, framed building were conducted. The new method was also tested by measuring the physical vibrations of a scale model under controlled damage conditions. Both variations of the method proved to be suitable, successfully identifying the location of damage and quantifying the stiffness reductions under various conditions.
Temperature instability of low‐temperature deposited a‐Si:H TFTs fabricated on plastic substrate
Authors: Ho K. Y. , Cheng C. H. , Cheng C. C. , Chen P. C. , Yeh Y. H.
Published: May 2008

Abstract— Low‐temperature deposited a‐Si:H TFTs have been successfully fabricated on colorless polyimide (CPI) substrate for flexible‐display applications. A serious degradation in threshold voltage was observed after applying external thermal stress. The threshold‐voltage shift saturates after applying several thermal stress cycles. In addition, the TFTs show instability under long periods of thermal stress with fixed temperature. This phenomenon was composed of thermally induced traps and substrate‐expansion‐induced mechanical stress. Finally, the a‐Si:H TFT backplane fabricated on a PI substrate at low temperature has been successfully demonstrated for flexible AMLCDs.
Energy‐transfer dynamics of blue‐phosphorescent iridium and rhodium complexes doped in fluorescent molecules
Authors: Tanaka Isao , Shibata Kazuyuki , Tokunaga Eiji , Tokito Shizuo
Published: May 2008

Abstract— The temperature‐dependent photoluminescence features of polycarbonate thin films doped with blue‐phosphorescent molecules, either bis[(4,6‐difluorophenyl)‐pyridinato‐N,C2′] (picolinate) iridium (Flrpic) or bis(2‐phenylpyridinato‐N,C2′) (acetylacetonate) rhodium [(ppy)2Rh(acac)], which have an equivalent triplet energy of 2.64 eV, have been studied. The photoluminescence intensity of the Flrpic‐doped polycarbonate thin film did not show any dependence on temperature. On the other hand, as for the (ppy)2Rh(acac)‐doped polycarbonate thin film, decreasing photoluminescence intensity with increasing temperature (especially above 100K) was clearly visible. These results reflect that the internal heavy‐atom effect of (ppy)2Rh(acac) is weaker than that of Flrpic. Furthermore, the steady‐state and time‐resolved photoluminescence spectra of tris(8‐hydroxyquinoline) aluminum (Alq3) thin films heavily doped with Flrpic or (ppy)2Rh(acac) (50 wt.%) at 8K was studied. It was found that the enhanced phosphorescence from Alq3 is mainly due not to the external heavy‐atom effect by doping with the phosphorescent molecule but to the exothermic triplet energy transfer from the phosphorescent molecule to Alq3.
Performance of liquid‐crystal displays for fire‐service thermal‐imaging cameras
Authors: Dinaburg Joshua B. , Amon Francine , Hamins Anthony , Boynton Paul
Published: May 2008

Abstract— As use of handheld thermal‐imaging cameras (TICs) becomes more prevalent in the first‐responder community, it is important that standard test metrics be available to characterize imaging performance. A key performance consideration is the quality of the image presented on the TIC display. This paper focuses on TICs that use liquid‐crystal displays to render an image for the user. Current research on TIC performance for first‐responder applications makes use of trained observers and/or composite‐video‐output‐signal measurements. Trained observer tests are subjective and composite video output tests do not evaluate the performance of the complete imaging system. A non‐destructive objective method was developed that tests the performance of the entire thermal‐imaging system, from the infrared sensor to the display. A thermal target was used to correlate the measured thermal imager composite video output signal with the luminance of the display. A well‐characterized charge‐coupled‐device (CCD) camera and digital recording device were used to measure the display luminance. An electro‐optical transfer function was determined that directly relates the composite video output signal to the luminance of the display, providing a realistic characterization of system performance.
Applying Mise-a-la-masse Method to Determine the Length of Reinforcement in Bored In situ Concrete Piles
Authors: Dong Ping , Fan Jingliang , Chen Zhengzhou , Wang Liangshu , Gao Xinnan , Qin Ran
Published: May 2008

The strength of reinforced concrete pile is largely controlled by the steel reinforcement inside the pile. Finding an effective way to determine the length of the steel reinforcement in bored in situ concrete piles has been an urgent but difficult problem for the construction administration agencies in China. Taking advantage of the significant difference in the electrical conductivity between the steel reinforcement and the concrete pile body, we apply the mise-a-la-masse (MALM) method, which has traditionally been used in ore exploration and coal mining, to determine the reinforcement length of bored in situ concrete piles. Preliminary tests show that the voltage (electrical potential) curve sharply increases at the bottom of the steel reinforcements, where the voltage gradient curve also peaks. Thus, the MALM method could be an effective, fast and convenient way to determine the reinforcement length in bored in situ concrete piles. The MALM method may also be used in the survey of old steel piles, bridge footings and dam foundations whose configurations are not available.
Simulation and Experimental Studies of Mineral Scale Formation Effects on Performance of an Iranian Carbonate Oil Reservoir Under Water Injection
Authors: Taheri A. , Masoudi R. , Zahedzadeh M. , Ataei A. R. , Fakhri H.
Published: May 2008

Water injection is an enhanced oil recovery method which is applied for number of reservoirs around the world especially offshore fields. Sea-water injection process is usually associated with important concerns affecting the efficiency, safety, and economy of the operation like formation damage, mineral scaling, early breakthrough and corrosion. Incompatibility between injected and formation waters may result in inorganic scale precipitation in the reservoir and then reduction of oil production rate (productivity loss) and water injection rate (injectivity loss). A comprehensive study supported by reliable modeling and experimental investigation will therefore, significantly improve the success of the operation.

In this paper, mineral scale deposition phenomenon in one of Iranian offshore carbonate oil reservoir under water injection is studied and its influence on reservoir performance and production rate is investigated. For this purpose, an extensive experimental work has been conducted on compatibility of sea and formation waters and the amount and type of scale formed as a result of mixing different portions of these waters. Experimental results have been applied and incorporated with simulation studies. STARS simulator (from CMG 2005) that is capable of evaluating the effect of scale formation on reservoir performance allowing for alteration of permeability and the flow path has been used in simulation study. One of the major contributions of this work is to incorporate the equilibrium conditions, reaction rates and solubility parameters for various scale types in reservoir simulation, so the results can be more realistic.

The simulation results show that in oil reservoirs under water injection, scale formation undermines the productivity index and has a major impact on reservoir performance. These results have been confirmed by production history of the field.
Detection of Scale Deposition Using Distributed Temperature Sensing
Authors: Almutairi Fajhan H. , Davies David R.
Published: May 2008

The rapid deployment of distributed temperature sensor (DTS) systems in the oil and gas E&P industry provided the engineers with large amount of real-time, downhole data. Although the basic principles for DTS operations are simple, the interpretation of the downhole data presents a challenge for the production engineer. Inflow profiling has been promoted as the prime reason for the installation of DTS systems, though DTS data are currently used in all aspects of production engineering. The differences between the thermal properties of oil, gas and water allow the detection of unwanted fluids using DTS. Monitoring of the produced fluid temperature allow the engineer to prevent the formation of wax and hydrates, ensuring effective flow assurance.

This paper examines a novel DTS application by analyzing the effect of scale deposition on the temperature profile of a conventional producing well. The low thermal conductivity of scale deposits increases the temperature of the producing fluid in the scaled region. A sensitivity study has examined the expected range of temperature increase caused by scale deposition to determine the conditions under which the flowing fluid temperature increase is a maximum.

Low to moderate production rate environments with low water production yield the greatest increase in flowing fluid temperature when scale is present. The thermal insulation provided by the scale causes a unique temperature profile. Quantitative analysis allows the scale thickness to be determined.
Seawater Injection, Inhibitor Transport, Rock-Brine Interactions, and BaSO4 Scale Control During Seawater Injection
Authors: Shen Dong , Fu Gongmin , Al-Saiari Hamad , Kan Amy T. , Tomson Mason B.
Published: May 2008

Field engineers and reservoir modelers often question if equilibrium conditions prevail downhole and when do super(sub)saturation conditions exist. This is especially critical in designing seawater injection for pressure maintenance due to serious barite scale problem in barium containing formation. The objective of this paper is (1) to discuss the experimental research on rock-brine interaction to determine when equilibrium condition prevail and when kinetics prevail; and (2) to develop realistic seawater/inhibitor injection schemes for scale control during seawater injection.

We have examined the question from three points of view: 1. thermodynamic equilibrium; 2. mass transport kinetics; and 3. experimental testing of flow through columns with or without scale inhibitors. If the reaction direction is from undersaturated toward saturation, then equilibrium normally occurs rapidly. Equilibrium is observed within about 5 min. When the reaction is going from supersaturated to equilibrium direction, such as during seawater injection into a barium containing formation, the precipitation reaction is often slow, i.e., equilibrium is not observed after 10 min of contact time. Both barite dissolution and precipitation rates on clean core material are consistent with those reported in literature with a second order rate constants for dissolution (≈ 30,172 l2·mol-1·m-2·sec-1, 100 °C) and precipitation (= 938 l2·mol-1·m-2·sec-1, 100 °C).

The kinetics of barite formation can significantly slow down in the presence of scale inhibitors and the sulfate tolerance can be increased. The kinetics of both barite dissolution and precipitation are poorly understood at the present time. It is proposed that combining sulfate reduction and scale inhibitor application in intelligent engineering design can significantly reduce the problems and costs associated with seawater injection. Equations for engineering design of such treatment were derived from nucleation kinetics, inhibition efficiency, and inhibitor adsorption and transport. Sulfate tolerance in the presence of scale inhibitors is measured and compared with the prediction from nucleation inhibition theory with excellent agreement. An innovative inhibitor treatment via core flood has been done as proof-of-concept and will be discussed.
The Challenges Associated With Performing and Combining Scale Dissolver and Squeeze Treatments in Kristin—A Subsea HP/HT Gas Condensate Field
Authors: Wat R. , Wennberg K. , Holden R. , Hustad B , Heath S. , Archibald M. , Singdahlsen K.
Published: May 2008

With an initial reservoir pressure of 911bar and a downhole temperature of 170°C Kristin is the first HPHT field in the world that has been completed and produced using subsea solutions. CaCO3 scale has been identified as the major production problem due to the expected high draw down from the reservoir together with the high level of bicarbonate and calcium in the formation water. In April 2007 breakthrough of formation water in two of the wells were detected and the subsurface safety valve in one of them showed increasing inertia. In August/September 2007 the first combined scale dissolver & squeeze treatments were carried out in these two wells. This culminated after more than 5 years of testing of a large variety of chemicals and operational planning. The jobs were successfully carried out using the unique HP injection system on board that is dedicated for such well intervention. In this paper a full case history of these first treatments on Kristin will be presented. It starts with a brief summary of the difficult path to qualify various chemicals for the challenging conditions. This is followed by the early detection, diagnosis and data interpretation processes when the formation water first broke through. The paper will include the operational planning with special focus on the constraints to inject chemicals at an adequate rate against a HPHT well. The challenges in delivering and maintaining separation of the different chemical pills to a well lying 7km away will be highlighted. Despite the best intension some compromises on the treatment design have to be made in order to maintain safety and system integrity and these will be discussed. Finally the paper will conclude by presenting the results from these treatments, the assessment of the operations, the experiences being learnt and the area identified for future improvement.
Integrity Control In Heavily Fouled Systems–Environmentally Friendly Solutions
Authors: Monk Keith A. , Horsup David I. , Richard Meyer G. , Willis Martin J.
Published: May 2008

Corrosion control of heavily fouled systems poses a significant challenge for integrity management programs. In cases where deposits build up in pipelines, or within pits, it is virtually impossible for a corrosion inhibitor to penetrate the deposit and impart inhibition at the underlying surface. The inhibitor simply adsorbs onto the deposits while corrosion continues unabated at the metal surface.

The research presented in this paper extends our earlier work into the development of multifunctional corrosion inhibitor products that are extremely effective at removing pipeline deposits and mitigating corrosion. The focus of this paper is the development of a new formulation containing a patent-pending corrosion inhibitor active that exhibits these properties, in addition to meeting the most stringent environmental regulations governing the use of production chemicals in the North Sea.
The Cost and Value of Field, Laboratory, and Simulation Data for Validating Scale Inhibitor Treatment Models
Authors: Patroni Zavala J. A. , Mackay E. J. , Vazquez O. , Boak L. S. , Singleton M. , Ross Gill
Published: May 2008

Scale formation presents a flow assurance challenge to the oil and gas industry. Scale inhibitor squeeze treatments are the most common method used to prevent scale deposition in subsurface applications. Software tools exist which are routinely used to assist with the challenges posed by scale. An important step in using predictive simulation models is validation. Validation requires the collection of field or laboratory data for comparison with the model predictions. The cost and value of various data required for designing scale inhibitor squeeze treatments with SQUEEZE VI has been assessed.

The first stage of designing a scale inhibitor squeeze treatment is chemical selection. Corefloods are used to derive an inhibitor-rock interaction function called an isotherm. The possible consequence of terminating a coreflood too early has been demonstrated. An opportunity for reducing the man-hours required to derive an isotherm has been identified.

The water production and injection profile in a well is valuable information which, when incorporated into a squeeze treatment model, improves the accuracy of the model's prediction. Possible methods for obtaining this data have been reviewed. The consequences of modelling a squeeze treatment with the wrong flow profile have been demonstrated.

After executing a squeeze treatment brine samples are collected and scale inhibitor concentrations are measured. This data is used to determine when the treatment should be repeated and to history match the squeeze treatment model. The cost per barrel of treated fluid may be reduced by collecting samples less frequently. The impact and risk of reducing the sampling frequency on the ability to predict a treatment's lifetime is demonstrated. Lastly, the possible outcomes of reducing the sampling frequency on the ability to effectively history match a model are demonstrated.
Coupled Adsorption/Precipitation Of Scale Inhibitors: Experimental Results And Modelling
Authors: Kahrwad M. , Sorbie K. S. , Boak L. S
Published: May 2008

In this paper, results are presented on the general mechanisms by which scale inhibitors (SIs) are retained within porous media. There is a generally accepted view that the main two mechanisms of SI retention are "adsorption" and "precipitation" and these are described by different but related modelling approaches in the literature. These approaches have been used quite successfully to model field squeeze treatments. To analyse in a detailed and unambiguous manner where a given retention mechanism (e.g. pure adsorption) or mechanisms (e.g. coupled adsorption and precipitation) are operating requires that we carry out careful laboratory experiments under "field relevant" conditions.

In this work, we study adsorption vs. adsorption/ precipitation by performing a series of experiments where we know that the system exhibits either (a) adsorption only or (b) coupled adsorption/precipitation. Experimentally it is straightforward to determine which regime the system is in, as explained below. We present the theory describing the coupled adsorption/precipitation process. In addition, an extensive series of experimental adsorption/precipitation measurements are presented for various mineral separates including sand, chlorite, siderite, muscovite, kaolinite, feldspar and montmorillonite. The coupled adsorption/ precipitation model is in very good agreement with experiment.
Using Modeling and Data Analytics To Signal Change: Can We Avert a "Midlife Crisis"?
Authors: Durnie Will , Harrop Don
Published: May 2008

More often than not we have more data than we know what to do with. The availability of large amounts of data should enhance decision making but often has the opposite effect. The sheer amount of data, combined with the pressure to make smarter and faster decisions often overwhelms decision-makers. This holds true in the world of corrosion as much as any other field.

The cost of acquiring data and the risks of misinterpretation are significant. Any manipulation of data which can reveal aspects/patterns that are linked to corrosion will help to minimize risks and assessment of the condition of an operating system. Increased capability to manage risk has the potential to add significant value through optimization of effectiveness for monitoring, inspection and chemical deployment as well as timely identification and selection of equipment for repair/replacement.

Given the critical importance that estimation of corrosion rate has in determining risk of future failure and in the estimation of the time to repair/replacement, this paper outlines the concepts of alternative and complementary means of estimating this rate/condition using data analytical methods. In addition to consideration of local estimates of corrosion rate (i.e. spot ultrasonic data or in-line inspection data) the activity has involved processing a large set of rate estimates to search for predictive patterns based on attributes of the lines, process conditions, coupon/probe data, similarity of service conditions and use of inhibition chemicals.
Development and Applications of the HYDRUS and STANMOD Software Packages and Related Codes
Authors: Šimůnek Jirí , van Genuchten Martinus Th. , Šejna Miroslav
Published: May 2008

Mathematical models have become indispensable tools for studying vadose zone flow and transport processes. We reviewed the history of development, the main processes involved, and selected applications of HYDRUS and related models and software packages developed collaboratively by several groups in the United States, the Czech Republic, Israel, Belgium, and the Netherlands. Our main focus was on modeling tools developed jointly by the U.S. Salinity Laboratory of the USDA, Agricultural Research Service, and the University of California, Riverside. This collaboration during the past three decades has resulted in the development of a large number of numerical [e.g., SWMS_2D, HYDRUS‐1D, HYDRUS‐2D, HYDRUS (2D/3D), and HP1] as well as analytical (e.g., CXTFIT and STANMOD) computer tools for analyzing water flow and solute transport processes in soils and groundwater. The research also produced additional programs and databases (e.g., RETC, Rosetta, and UNSODA) for quantifying unsaturated soil hydraulic properties. All of the modeling tools, with the exception of HYDRUS‐2D and HYDRUS (2D/3D), are in the public domain and can be downloaded freely from several websites.
The PTPN22 1858T Gene Variant in Type 1 Diabetes Is Associated With Reduced Residual β-Cell Function and Worse Metabolic Control
Authors: Petrone Antonio , Spoletini Marialuisa , Zampetti Simona , Capizzi Marco , Zavarella Sara , Osborn John , Pozzilli Paolo , Buzzetti Raffaella ,   for the Immunotherapy Diabetes (IMDIAB) Group
Published: May 2008

OBJECTIVE—Evidence has been reported for a new susceptible locus for type 1 diabetes, the protein tyrosine phosphatase nonreceptor type 2 (PTPN22), which encodes a lymphoid-specific phosphatase. The aim of the study was to evaluate the influence of the C1858T variant of the PTPN22 gene on β-cell function as measured by C-peptide levels from time of disease diagnosis through 12 months follow-up in a prospective series of 120 consecutive type 1 diabetic subjects.

RESEARCH DESIGN AND METHODS—The C1858T polymorphism was genotyped using TaqMan. Fasting C-peptide, A1C, and insulin requirements were determined at diagnosis and every 3 months for 12 months; their change during follow-up was analyzed using the general linear model repeated-measures procedure.

RESULTS—Fasting C-peptide levels were significantly lower and A1C levels were significantly higher in subjects carrying the PTPN22 1858T variant than in subjects homozygous for C1858 from time of disease diagnosis through 12 months of intensive insulin therapy follow-up (P = 0.008 and P = 0.01, respectively). These findings were independent of age at onset, sex, and HLA risk groups. The trend in C-peptide and A1C levels in the 12-month period did not differ significantly between subjects with or without the 1858T variant. Insulin dose was similar in the 1858T carriers and noncarriers.

CONCLUSIONS—Type 1 diabetic subjects carrying the 1858T variant show significantly lower β-cell function and worse metabolic control at diagnosis and throughout the study period than subjects homozygous for C1858; these differences remain unchanged over the course of the first year after diagnosis.
A Community-Based Diabetes Prevention and Management Education Program in a Rural Village in India
Authors: Balagopal Padmini , Kamalamma N. , Patel Thakor G. , Misra Ranjita
Published: May 2008

OBJECTIVE—In this study we evaluated a 7-month community-based nonpharmacological lifestyle intervention to prevent/reduce the risk of developing diabetes and its complications in a resource-poor village in Tamilnadu, India.

RESEARCH DESIGN AND METHODS—A total of 703 village inhabitants, comprising adults and youth aged 10–92 years, were provided educational intervention using “trained trainers.” Culturally and linguistically appropriate health education messages addressed diet, physical activity, and knowledge improvement. The prevalence of diabetes and the effectiveness of the intervention were assessed using select parameters.

RESULTS—The crude prevalences of diabetes and pre-diabetes among adults were 5.1 and 13.5%, respectively, while the prevalence of pre-diabetes in youth aged 10–17 years was 5.1%. Intervention reduced fasting blood glucose levels of pre-diabetic adults by 11%, pre-diabetic youth by 17%, and type 2 diabetic adults by 25%. Improvements in obesity parameters and dietary intake also occurred. A stepwise worsening of parameters progressing from the normoglycemic state to the impaired levels of pre-diabetes and diabetes was observed.

CONCLUSIONS—This study has charted the increasing prevalence of diabetes and pre-diabetes in rural India. Educational intervention was successful in reducing some of the obesity parameters and improving dietary patterns of individuals with pre-diabetes and diabetes.
Incidence and Risk Factors for New-Onset Diabetes in HIV-Infected Patients
Authors: De Wit Stephane , Sabin Caroline A. , Weber Rainer , Worm Signe Westring , Reiss Peter , Cazanave Charles , El-Sadr Wafaa , Monforte Antonella d'Arminio , Fontas Eric , Law Matthew G. , Friis-Møller Nina , Phillips Andrew
Published: May 2008

OBJECTIVE—The aims of this study were to determine the incidence of diabetes among HIV-infected patients in the Data Collection on Adverse Events of Anti-HIV Drugs (D:A:D) cohort, to identify demographic, HIV-related, and combination antiretroviral therapy (cART)-related factors associated with the onset of diabetes, and to identify possible mechanisms for any relationships found.

RESEARCH DESIGN AND METHODS—D:A:D is a prospective observational study of 33,389 HIV-infected patients; diabetes is a study end point. Poisson regression models were used to assess the relation between diabetes and exposure to cART after adjusting for known risk factors for diabetes, CD4 count, lipids, and lipodystrophy.

RESULTS—Over 130,151 person-years of follow-up (PYFU), diabetes was diagnosed in 744 patients (incidence rate of 5.72 per 1,000 PYFU [95% CI 5.31–6.13]). The incidence of diabetes increased with cumulative exposure to cART, an association that remained significant after adjustment for potential risk factors for diabetes. The strongest relationship with diabetes was exposure to stavudine; exposures to zidovudine and didanosine were also associated with an increased risk of diabetes. Time-updated measurements of total cholesterol, HDL cholesterol, and triglycerides were all associated with diabetes. Adjusting for each of these variables separately reduced the relationship between cART and diabetes slightly. Although lipodystrophy was significantly associated with diabetes, adjustment for this did not modify the relationship between cART and diabetes.

CONCLUSION—Stavudine and zidovudine are significantly associated with diabetes after adjustment for risk factors for diabetes and lipids. Adjustment for lipodystrophy did not modify the relationship, suggesting that the two thymidine analogs probably directly contribute to insulin resistance, potentially through mitochondrial toxicity.
Screening for Depressive Symptoms
Authors: Stahl Dorit , Sum Chee Fang , Lum Shin Si , Liow Pei Hsiang , Chan Yiong Huak , Verma Swapna , Chua Hong Choon , Chong Siow Ann
Published: May 2008

OBJECTIVE—We determined the reliability and validity of the Center for Epidemiologic Studies Depression Scale (CES-D) against the DSM-IV–based diagnostic inventory, Schedule for Clinical Assessment in Neuropsychiatry (SCAN), in a multiethnic sample of adult subjects with diabetes attending a diabetes center in Singapore.

RESEARCH DESIGN AND METHODS—A total of 522 subjects (74.7% Chinese, 11.1% Malay, and 14.2% Indian) completed culturally adapted versions of the CES-D; 291 subjects were administered the SCAN inventory.

RESULTS—The CES-D (cutoff score 16) showed high negative predictive values of more than 90% in all three ethnic groups. The prevalence of depressive symptoms (CES-D) and depression (SCAN) was significantly different between the Chinese and Indian subjects (CES-D 27.4 vs. 43.2%, P = 0.006); (SCAN 15.0 vs. 31.1%, P = 0.01).

CONCLUSIONS—The CES-D proved to be a reliable instrument for identifying patients with depressive symptoms in the multiethnic setting of this study.
Sex Hormone–Binding Globulin and Testosterone in Individuals With Childhood Diabetes
Authors: Danielson Kirstie K. , Drum Melinda L. , Lipton Rebecca B.
Published: May 2008

OBJECTIVE—Insulin downregulates hepatic production of sex hormone–binding globulin (SHBG), which in turn influences sex hormone bioavailability. The effects of childhood-onset diabetes and insulin resistance in nondiabetic individuals on SHBG and testosterone in children and young adults are poorly understood.

RESEARCH DESIGN AND METHODS—Individuals with diabetes diagnosed at <18 years of age (n = 48) and their siblings without diabetes (n = 47) were recruited for the Chicago Childhood Diabetes Registry Family Study. SHBG and total and free testosterone were measured. Participants ranged in age from 10 to 32 years; 39% were non-Hispanic white. The majority of individuals with diabetes had the classic type 1 phenotype (75%), while the remainder exhibited features of type 2 or mixed diabetes; 96% were treated with insulin.

RESULTS—SHBG and total testosterone were higher in male subjects with diabetes compared with those in male siblings. Elevated SHBG was associated with the absence of endogenous insulin independent of sex; elevated total testosterone was similarly associated with the absence of C-peptide for male subjects only. Diabetes type and treatment were unrelated. In those without diabetes, greater insulin resistance had a small, nonsignificant association with lower SHBG and higher free testosterone.

CONCLUSIONS—SHBG and total testosterone appear to be higher in male children and young adults with diabetes compared with nondiabetic male siblings, which is apparently related to the absence of endogenous insulin. This may have implications for sex hormone–dependent processes across the lifespan in male individuals diagnosed with diabetes as children.