bluuebunny/crossref_metadata_2025 huggingface dataset:
Successful Optimization of Viscoelastic Foamed Fracturing Fluids with Ultra-Lightweight Proppants for Ultra Low Permeability Reservoirs
Authors: Cawiezel Kay E. , Gupta D. V. S.
Published: January 2009

Successful fracturing treatments in ultra low permeability reservoirs require combining the most recent innovations in fracturing technologies. Viscoelastic surfactants, foams and ultra lightweight proppants have specific properties that when combined offer the unique performance required by the demands of fracturing these reservoirs. Inexpensive, logistically simple, polymer-free viscoelastic surfactants provide exceptionally high viscosity under low shear conditions required for proppant transport. They also provide excellent cleanup characteristics. Foamed viscoelastic surfactants provide increased viscosity for frac width, better leak off control and further improve fluid cleanup characteristics, particularly in low pressure reservoirs. Ultra-lightweight proppants provide excellent transport properties in conventional fracturing fluids with minimal viscosity, which ensures desired effective propped fracture conductivity. Utilization of these revolutionary ultra lightweight proppants in foamed viscoelastic fluids provides fracturing treatments with optimum proppant placement and excellent cleanup. As with all successfully applied fracturing fluids the fluid systems must be optimized. These combined systems require significant laboratory testing to successfully characterize and optimize the fluid system for the demands of ultra low permeability reservoirs. This paper focuses on small and large scale laboratory testing performed to optimize these viscoelastic-foamed systems in an effort to test the technical limit of this new technology for future field developments.
Simultaneous Hydraulic Fracturing of Adjacent Horizontal Wells in the Woodford Shale
Authors: Waters George , Dean Barry , Downie Robert , Kerrihard Ken , Austbo Lance , McPherson Bruce
Published: January 2009

Hydraulic fracturing of horizontal wells in shale gas reservoirs is now an established, commercially successful technique. The evolution of the completion technique has reached the point that numerous stimulation stages through multiple perforation clusters in wellbores with some form of annular isolation is now an accepted practice. The objective is to place multiple closely spaced hydraulic fractures. This has proven to be a viable development strategy for many shale reservoirs in North America.

To further enhance the recovery factor in these ultra low permeability reservoirs simultaneously hydraulically fracturing of adjacent wellbore is increasingly being tested. Most of the time this is performed in horizontal wellbores paralleling each other. The goal is to create hydraulic fractures more closely spaced than can be achieved from a single wellbore. When real time microseismic monitoring of the stimulation treatments is incorporated changes can be made "On-the-Fly" to improve the effective stimulated reservoir volume.

Continental Resources has employed simultaneous hydraulic fracturing as a development strategy for their Woodford Shale acreage in the Arkoma Basin of Eastern Oklahoma. To monitor the effectiveness of the stimulations geophones have been deployed into horizontal wellbores to record microseismic events when offsetting vertical wellbores are unavailable. Cased hole sonic logs have also been run to quantify cement bond quality, estimate stress variation along the lateral, and to pick optimum perforating points.

This paper reviews the methodology employed in the completion design and process. The impact of the simultaneous stimulations and geologic structure on the fracture geometry are shown as well as the impact on well productivity.
Modeling Simultaneous Growth of Multiple Hydraulic Fractures and Their Interaction With Natural Fractures
Authors: Olson Jon E. , Dahi-Taleghani Arash
Published: January 2009

Hydraulic fracture diagnostics have highlighted the potentially complex natural of hydraulic fracture geometry and propagation. This has been particularly true in the cases of hydraulic fracture growth in naturally fractured reservoirs, where the induced fractures interact with pre-existing natural fractures. A simplified numerical model has been developed to account for mechanical interaction between pressurized fractures, and to examine the simultaneous propagation of multiple (>2) hydraulic fracture segments. Fracture intersection is presumed to communicate the hydraulic fracturing fluid to the natural fracture, which then takes up the continued propagation. Simulations for multi-stage horizontal well treatments and single stage vertical well treatments show that fracture pattern complexity is strongly controlled by the magnitude of the hydraulic fracture net pressure relative to the in situ horizontal differential stress as well as the geometry of the natural fractures. Analysis of the neartip stress field around a hydraulic fracture also indicates that induced stresses may be high enough to debond sealed natural fractures ahead of the arrival of the hydraulic fracture tip.
Surface Etching Pattern and its Effect on Fracture Conductivity in Acid Fracturing
Authors: Antelo Luis Fernando , Pournik M. , Zhu D. , Hill A. D.
Published: January 2009

Conductivity in acid fracturing after fracture closure depends on the contact of the non-uniformly etched fracture surfaces created by the acid. The surface topography of the fracture faces after acid injection is rarely investigated and, therefore, poorly described. The concept of average fracture width has been used in the fracture conductivity models to predict fracture conductivity in acid fracturing. Previous study showed that the characterization of fracture faces after acid etching plays an important role in fracture conductivity. If channels and wormholes are created, fracture conductivity cannot be described by the conventional model. For more evenly distributed etching, surface topography characteristic strongly influences the resulting conductivity. With a surface profilometer, a laser device that accurately measures the height of the asperities on the rock surface, we obtain a digital image that can be used to quantitatively characterize the etched surface topography after acidizing. Using this data we are able to define the channel geometry and etching patterns as numerical values. The distribution of these numerical values is later converted and analyzed as surface texture parameters and standard statistical variables for rough surface characterization. When two roughness parameters of each corresponding fracture surface are superposed, the fracture conductivity can be related to the statistical parameters of etching.

In this paper we present experimental results for a wide range of acid fracturing conditions that provide the variables and controlling parameters relating roughness of the fractures surface to fracture conductivity measurements. The findings of this study is important to understanding the effect of etcing pattern of fracture face on fracture conductivity behavior, and it also helps to develop lab scale fracture conductivity correlations in acid fracturing.
Method and Apparatus for Simultaneous Stimulation of Multi-Well Pads
Authors: Tolman R. C. , Simons J. W. , Petrie D. H. , Nygaard K. J. , Clingman S. R. , Farah A. M.
Published: January 2009

Progressively, the oil and gas industry is producing from unconventional reservoirs with low permeability in numerous small pay zones that require close well spacing and multiple stimulations in each well. To effectively produce from such reservoirs and reduce the surface footprint, ExxonMobil has drilled multiple wells from single pads, and new technologies have been developed to efficiently stimulate the multiple pay zones in each well.

ExxonMobil has developed and licensed Multi-Zone Stimulation Technologies (MZST), which are designed to efficiently stimulate wells with multiple pays zones. The technologies have been applied in fracturing tight gas reservoirs with numerous lenticular sands in the Rocky Mountains. We have also developed a technology that enables the simultaneous stimulation of multiple wells on the same or different well pads, and while drilling additional wells. The benefits of this technology include reduced environmental impact, time saving, and improved production rates. Most importantly we have demonstrated that these simultaneous operations can be conducted in a safe and responsible manner to ensure the highest standards of operations integrity.

This paper introduces the method and apparatus for this technology and discusses the results from several years of field applications, including the Piceance Basin. Some specific elements of the simultaneous operations safety plan will also be provided.
Residential water demand under block rates – a Portuguese case study
Authors: Martins Rita , Fortunato Adelino
Published: January 2009

A residential water demand equation is estimated using a panel data sample of five Portuguese local communities and 72 months, corresponding to a total number of 360 observations. Because of the presence of multi-part tariffs, we use the two common price-related variables: marginal price and difference as explanatory variables. To prevent the simultaneity bias from using observed quantities to determine the values of marginal price and difference directly from the rate schedule, we use an instrumental variable approach to create a constant marginal price and difference parameters for each rate structure.

The price elasticity values obtained fall within the range of those found in other case studies. Thus, although presenting weak elasticity, price seems to play a role in water demand management. However, we do not confirm the expected influence of difference on residential water demand. This can be a consequence of the complexity of the Portuguese water tariffs and the confusing signs that come from the simultaneous use of fixed quotas and increasing block tariffs. So, it is imperative to clarify water tariffs objectives by reviewing the Portuguese water tariffs design processes.
Assessing integrated water resources management in Nigeria: insights and lessons from irrigation projects in the Cross River Basin
Authors: Akpabio Emmanuel M.
Published: January 2009

This paper examines the practice of integrated water resources management (IWRM) in the Cross River Basin, Nigeria. Specific case studies have been made of the irrigation projects of the Cross River Basin Development Authority (CRBDA) to generate issues and examine implications on the concept of IWRM. A wide range of study methods, including semi-structured interviews, case studies of irrigation projects, personal correspondence, field visits, observation and secondary data was used in the research. In the results, it was observed that the CRBDA irrigation projects are highly under-utilised. The authority has acquired many hectares of land but has developed only 3.4%.There were a number of factors that explained this. These ranged from poor user interests and financing, fragmented and inconsistent policies, declining funding and political commitment as well as problems of accountable and transparent management practices. The paper argues that the above factors relate to the overall influences of macro and micro institutional processes as well as physical challenges that border on water and related resources management in the area. Based on these issues the paper concludes that the policy on IWRM in Nigeria was a sweeping experiment with no meaningful consideration of local contexts and circumstances as well as other institutional issues for operation.
PPP – policies, practices and problems in Ghana's urban water supply
Authors: Fuest Veronika , Haffner Stefan A.
Published: January 2009

Since the beginning of the 1990s, comprehensive reforms of the Ghanaian water sector were initiated by the Bretton Woods Institutions. The Government of Ghana was obliged to restructure the sector by establishing regulatory bodies, opening the sector to private sector participation and separating responsibilities for urban water supply from rural water supply. The parastatal Ghana Water Company Limited (GWCL) was created to be solely in charge of urban water supply. In spite of external assistance, GWCL continued to suffer from massive financial, managerial and technical problems. The gap between supply and demand increased while demand for potable water in the cities was on the rise and the supply systems were degenerating.

In order to introduce greater efficiency, two options for public–private partnerships (PPP) were developed and contested, over a period of 10 years. At first private companies were invited to take over the GWCL by a lease contract. Numerous factors, among them a massive anti-privatisation campaign and global economic trends unfavourable to private investment, particularly in the water sector, caused a comprehensive revision of the policy and the modification of the PPP programme from lease to short-term management contract with an ensuing affermage concession in 2004. This process was to be supported by external donor agencies substantially upgrading the water supply infrastructure. However, it seemed doubtful if the recent policy would lead to a sustainable system of urban water supply and substantial improvements in the supply situation of the poor. Patronage relations were not sufficiently addressed and alternative PPP options based on local potential had not been considered. The case of Ghana raises issues of imposed PPP policies that are not based on adequate information about local, national and international framework conditions.
Simulation of the Agro-Biomass(Olive Kernel) Fast Pyrolysis in a Wire Mesh Reactor Considering Intra-Particle Radial and Temporal Distribution of Products
Authors: Damartzis Theodoros , Kostoglou Margaritis , Zabaniotou Anastasia
Published: January 2009

In the present study, a model for the fast pyrolysis of a spherical biomass particle has been developed. The model admits the generation of data which are not accessible experimentally such as the intra-particle temperature and concentration distribution. Simulations have been carried using data from the reactor as well as from literature and the effects of the heating rate and the particle size have been examined. The kinetic model is coupled with a heat transfer model. The reaction kinetic constants have been chosen in order to match the theory to the data taken from experiments carried out in a laboratory wire mesh reactor, for a temperature range from 573 K to 873 K and a heating rate of 200 K/s. Pyrolysis temperature and product distribution profiles in both spatial and temporal directions throughout the particle are presented. The effects of the particle size and the reactor's heating rate in the final pyrolysis products and temperature are shown and discussed. Simulations were carried out using Matlab and the model has been validated against the experimental results. The heating rate, which is an important operating condition in thermal processes, seems to have a positive effect on the biomass conversion to gaseous and liquid products, an increase of the first resulting to an increase of the second. Particle size was found to have a negative effect on pyrolysis conversion as larger particles tend to give higher char yields. For the particular experimental system analyzed here, it seems that the radial non-uniformity is not very large and acceptable results can also be taken using a lumped particle model. Validation of the model with experimental data showed great accordance, thus the model could be used for the prediction of final pyrolysis yields and temperatures.
Bazedoxifene: A Selective Estrogen-Receptor Modulator
Authors: Mitwally Mohamed FM
Published: January 2009

Bazedoxifene is a third-generation selective estrogen-receptor modulator being developed for use alone or in combination with estrogen for prevention and treatment of osteoporosis in postmenopausal women. Preliminary clinical trials are encouraging. Bazedoxifene has been found to be efficacious in reducing bone turnover without adverse effects of breast pain. In Phase III studies, bazedoxifene was found to increase vasomotor symptoms when compared with placebo. This effect is similar to that of raloxifene. Lack of endometrial stimulation is another advantage. Current literature suggests that bazedoxifene is likely to be safe, well tolerated and effective for the treatment of postmenopausal osteoporosis. However, completion of Phase III clinical trials will further elucidate its safety and efficacy, as well as its advantages in comparison with other selective estrogen-receptor modulators.
Is SATB1 a Master Regulator in Breast Cancer Growth and Metastasis?
Authors: Zheng Jie
Published: January 2009

Evaluation of: Han HJ, Russo J, Kohwi Y et al.: SATB1 reprogrammes gene expression to promote breast tumor growth and metastasis. Nature 452(7184), 187–193 (2008). Metastasis is the most common cause of death in cancer patients. However, the genetic mechanisms involved in the master control genes of metastasis remain unclear. In this study, the authors found that special AT-rich sequence-binding protein 1 (SATB1) expression contributed to breast cancer growth and metastasis. SATB1 expression is detected in aggressive breast cancer cells rather than nonaggressive breast cancer cells. Moreover, by introducing the SATB1 gene into nonmetastatic breast cancer cells, invasive tumors can be induced in mice; whereas, silencing of SATB1 in metastatic cells not only abolishes metastasis and tumor growth in mice, but also returns cells to their normal appearance. These effects are related as SATB1 upregulates metastasis-associated genes while downregulating tumor-suppressor genes through epigenetic modification. The research suggests that SATB1 is a master regulator in the metastasis of breast cancer and, therefore, can be considered as an independent prognostic factor and a potential therapeutic target for breast cancer.
Recommending Mammography Screening beyond 80 Years of Age: A Time for Caution
Authors: Ciatto Stefano
Published: January 2009

Evaluation of: Badgwell BB, Giordano SH, Duan ZZ et al.: Mammography before diagnosis among women age 80 years and older with breast cancer. J. Clin. Oncol. 26, 5–8 (2008). While strong scientific evidence of efficacy supports the recommendation of mammography screening up to the age of 74 years, the current recommendation of continuing screening up to or beyond the age of 80 years, issued by several guidelines, is not based on controlled evidence of screening efficacy, but simply on the assumption that mammography increases its accuracy with age and that mammography screening must be beneficial, providing that life expectancy is long enough to allow for the benefit to take place. In the present study, a large series of breast cancer patients aged 80 years or above was considered, demonstrating that mammography use is associated with less advanced stage at diagnosis and with better survival. The authors conclude that the opportunity for continuing screening beyond the age of 80 years, owing to its potential benefit, should be discussed with patients, particularly those without significant comorbidity, foretelling a longer life expectancy. Although their findings may also suggest a benefit in terms of mortality reduction, the clear presence of a healthy screening effect, lead time and overdiagnosis considerations call for major caution, since screening might be more detrimental than beneficial.
Infertility Treatment for HIV-Positive Women
Authors: Semprini Augusto Enrico , Hollander Lital Hannah , Vucetich Alessandra , Gilling-Smith Carole
Published: January 2009

Thanks to antiretroviral combination therapy, HIV-infected individuals live longer, healthier lives and may wish to have children. Women with HIV can attempt to conceive naturally or through simple self-insemination to minimize the risk of horizontal HIV transmission. Assisted reproduction technology is necessary in couples with infertility, which can either be independent of HIV infection and its treatment or be associated with it. This article summarizes the latest evidence regarding the desire for a child in HIV-positive women and how HIV infection and its treatment may impact female fertility. Current data regarding access to and outcomes of assisted conception programs in HIV-positive women wishing to conceive in both high- and low-income countries is also reviewed.
Diagnosis and Treatment of Pelvic Inflammatory Disease
Authors: Haggerty Catherine L , Ness Roberta B
Published: January 2009

Pelvic inflammatory disease (PID), the infection and inflammation of the female upper genital tract, is a common cause of infertility, chronic pain and ectopic pregnancy. Diagnosis and management are challenging, largely resulting from varying signs and symptoms and a polymicrobial etiology that is not fully delineated. Owing to the potential for serious sequelae, a low threshold for diagnosis and treatment is recommended. As PID has a multimicrobial etiology, including Neisseria gonorrhoeae, Chlamydial trachomatis and anaerobic and mycoplasmal bacteria, treatment of PID should consist of a broad spectrum antiobiotic regimen. Recent treatment trials have focused on shorter duration regimens, such as azithromycin, and monotherapies including ofloxacin, but data are sparse. Research comparing sequelae development by differing antimicrobial regimens is extremely limited, but will ultimately shape future treatment guidelines.
Dysmenorrhea: Risk Factors in Women with Endometriosis
Authors: Liu Xishi , Guo Sun- Wei
Published: January 2009

Although it is generally accepted that endometriosis is responsible for dysmenorrhea, as well as other symptoms such as infertility, the precise relationship between the severity of dysmenorrhea and various characteristics of disease, such as stage and the type or site of endometriotic lesions, has been elusive and often a matter of heated debate, owing largely to conflicting reports. Here we review factors that are reported to be associated with dysmenorrhea in endometriosis. We also demonstrate, through a real example, that different statistical models employed in data analyses may yield somewhat different sets of risk factors, and the difference may not be always resolved within the same data set. In addition, we make the point that despite the best-fitting models, there may still be a sizable portion of variation in the severity of dysmenorrhea that can not be explained completely by the identified risk factors, suggesting that factors other than those of surgical findings or patient characteristics may also be responsible for dysmenorrhea severity. We review some possible factors that may also be responsible for the risk and severity of dysmenorrhea. Finally, we expose areas in need of further research.
Conservative Treatments in Breast Cancer: An Update from the European Institute of Oncology
Authors: Zurrida Stefano
Published: January 2009

Breast cancer is the most common cancer in women and is a major killer. Progress in treating the disease has been spectacular in recent decades and mortality is now declining in Western countries. This article describes the development of conservative surgical treatments for breast cancer and indicates future directions. Since they respect the integrity of the woman's body, conservative treatments have encouraged women to participate en masse in screening programs, plausibly resulting in earlier disease detection and greater curability.
Young Children Being Rhythmically Playful: Creating Musike Together
Authors: Alcock Sophie
Published: January 2009

This article explores young children's rhythmic, musical, aesthetic and playful creative communication in an early childhood education centre. Young children's communication is musically rhythmic and social. The data, presented as ‘events’, formed part of an ethnographic-inspired study conducted by the researcher as a participant observer. Cultural-historical activity theory (CHAT) framed the methodology, with mediated activity as the unit of analysis. Critical and related aesthetic theory inform the data analyses, providing open ways of appreciating diversity in young children's aesthetic experience. The collaborative nature of young children's rhythmic musicality is explored and the article suggests that rhythm pervades young children's creative and communicative playfulness.
Analysis of Classroom Management Problems in Primary Schools in Delta State, Nigeria
Authors: Oghuvbu Enamiroro Patrick , Atakpo Theresa Edirin
Published: January 2009

This article identifies classroom management problems, their causes, and possible ways to reduce these problems in primary schools located in Delta State, Nigeria. A total of 600 teachers selected from twelve local government areas participated in this study. Data were collected in a checklist containing 27 items and a two section questionnaire containing 19 items. Three research questions and three hypotheses were formulated and tested using percentage, bar and pie charts, chi-square and analysis of variance at 0.05 level of significance. The study revealed that common classroom management problems were related to students shouting, calling names, sleeping and talking/engaging in discussion during lessons. Identified causes of these problems were seen as originating in: overcrowded classrooms; parent neglect of the health conditions of children; and an unhygienic and below-standard teaching and learning environment. School location does not significantly influence teachers' views on identified causes and possible ways to reduce classroom management problems in primary schools in Delta State, Nigeria.
Toxicity of High-Dose Chlorambucil in Wistar Rats
Authors: Tomenendálová J. , Mayer J. , Doubek M. , Scheer P. , Horký D. , Řeháková Kristína , Doubek J.
Published: January 2009

The aim of this study was to determine the maximum tolerated dose and the haematological and non-haematological toxicity of chlorambucil in male Wistar rats. Chlorambucil (pulverized pills or pure substance) was dissolved in ethanol and administered orally at a dose ranging from 0.15 to 50 mg/kg/day for 5 days. Evaluations of experimental rats included general clinical state of health, body weight, haematological indicators (red blood cell count, white blood cell count, platelet count, differential leukocyte count, packed cell volume and haemoglobin concentration), biochemical plasma indicators (urea, creatinine, ALP, ALT, AST, Na, K, Cl), immunophenotype of leukocytes (CD3, CD8 and CD4 markers), as well as histopathology. Doses of chlorambucil from 0.15 to 0.75 mg/kg/day had no effect on the general clinical state of health as well as on other laboratory variables. Doses of 2–12 mg/kg/day were well tolerated, but mild myelotoxicity (leukopaenia) and elevated activities of liver transaminases were found. Doses of 20 to 50 mg/kg/day were myelotoxic (p < 0.01) with prevailing lymphopaenia but only minimum effects on red blood cells and platelets. Histology revealed pneumotoxicity, nephrotoxicity and damage to the gastrointestinal tract. Doses of 40 and 50 mg/kg/day resulted in acute lethal effects in 50% and 75% of individuals, respectively. Results of this study are intended for use in the testing of chlorambucil in combination with other drugs as a conditioning for bone marrow transplantation.
Equine Herpesvirus type 1 and 4 in Individually Reared Horses in Central and Western Turkey
Authors: Gür S. , Yapici O.
Published: January 2009

The objective of the study was to investigate EHV type 1 and 4 infections serologically in individually reared horses in Turkey. Equine herpesvirus 1 (EHV1) and 4 comprise two distinct viruses of horses of the Alphaherpesvirinae subfamily. EHV1 is a major cause of abortion, respiratory and neurological disorders in horses. EHV4 is responsible for respiratory disease in foals. In this study, EHV1 and 4 infections were investigated serologically in individually reared horses in Turkey. A total of 188 unvaccinated horses in four provinces were sampled and tested using indirect ELISA. EHV1- specific antibodies were found to be in three out of four provinces as 3.7% (7/188) between 4.5–6.9%. Test results showed that EHV4 is more prevalent than EHV1, the proportion varied among 48.4% and 65.7% in four provinces, 107 out of 188 samples (56.9%) were found to be seropositive. This is the first serological investigation for EHV1 and EHV4 in Turkey.
Radial Segmentation of Blood Lymphocytes Nuclei in Pheasants Vaccinated against Newcastle Disease and Haemorrhagic Enteritis
Authors: Graczyk S. , Wieliczko A. , Pliszczak-Król A. , Janaczyk B.
Published: January 2009

The purpose of the experiment was to investigate the influence of the pheasant vaccination with a vaccine containing live attenuated virus of haemorrhagic enteritis, (HE) on the ability of peripheral blood lymphocytes to form a nuclei deformation described as the radial segmentation (RS). This feature is identified with cytoskeletal rearrangement of the cells. The pheasants were vaccinated against Newcastle disease (ND) on the 1st, 28th and 56th day of life. Moreover, on the 49th day of life, a part of the birds was given the vaccine containing HEV (Haemorrhagic enteritis virus) in drinking water. Fourteen days after the HEV vaccination, the birds were administered intravenously 0.5 ml of the 10% SRBC (Sheep red blood cells) suspension. Blood samples were collected on the 21st day after HEV vaccination, on the 7th day after SRBC injection. It was shown that in pheasants the percentage of cells undergoing RS induced by oxalates was low, approximately 3.75%, whereas in HEV vaccinated birds this percentage increased twice (p < 0.05). Pheasant immunization with SRBC led to significant reduction of the ability to form RS, whereas in HEV vaccinated birds after SRBC administration the percentage of cells with RS remained on the level of the control group. Based on these results, the authors suggest that immunosuppressive effects of some viruses may be a result of both sensitivity and rearrangement ability changes in cytoskeletal proteins of the cells involved in immunological response.
Magnesium supplementation on children with severe protein energy malnutrition
Authors: Khalil Md Ibrahim , Al-Baki Abdullah , Akhter Nasrin , Al-Azad Md Abdus Samad , Zafreen Farzana , Wahab Md Abdul
Published: January 2009

doi:10.3329/jafmc.v4i2.1821

JAFMC Bangladesh Vol.4(2) 2008 10-13
Bile duct injury complications and management
Authors: Bhuiyan Jahangir Hossain , Khan MA Wahab , Rabbi ANM Atai , Akhter Latifa
Published: January 2009

doi:10.3329/jafmc.v4i2.1840 JAFMC Bangladesh Vol.4(2) 2008 21-26
Choledochoduodenal fistula secondary to duodenal ulcer disease and choledocholithiasis: Report of 2 cases
Authors: Al-Aziz Md Zakaria , Ahmed Mashrafi , Siddiqui Md Mahmudur Rahman , Shipa Md Ruhul Amin , Sarker Symal , Arif Syed Md , Siddiqui FM
Published: January 2009

doi:10.3329/jafmc.v4i2.1845 JAFMC Bangladesh Vol.4(2) 2008 38-41
Virtual Instrumentation Based Active Fin Control for Roll Stabilization
Authors: Subramanian V Anantha , Asokumar G , Mohamed Thaju
Published: January 2009

The objective of this work is to develop a non-traditional strategy for providing control of ship roll motion in a seaway using active fins. This is based on a multidisciplinary approach. It consists of the assessment of the hydrodynamic coefficients of a ship using a numerical package [SEDOS], representation of the hydrodynamic coefficients by suitable polynomial functions, identification of the time dependent fundamental frequency in the roll disturbance signal sample, generation of control signal for an appropriate fin angle based on the fin lift characteristics of the chosen fin and employment of feedback control to maintain the fin at the appropriate angle for maximum control. Once the ship based hydrodynamic coefficients are generated, the entire control algorithm is developed in the virtual instrumentation mode using LabVIEW environment. One of the disadvantages of the traditional stabilizer system is the enormous hardware involved in the controllers and instrumentation panels, which makes maintenance and troubleshooting difficult. With the help of virtual instrumentation, design of the stabilization controller and instrumentation panels can be carried out much more effectively, in comparison with the traditional hardware approach. Key words: Roll stabilization, Active fin control, Virtual instrumentation doi:10.3329/jname.v2i2.1869 Â Journal of Naval Architecture and Marine Engineering 2(2005) 11-24
Parental Smoking and Smoking Status of Japanese Dental Hygiene Students: A Pilot Survey at a Dental Hygiene School in Japan
Authors: Naito Toru , Miyaki Koichi , Naito Mariko , Yoneda Masahiro , Suzuki Nao , Hirofuji Takao , Nakayama Takeo
Published: January 2009

This study aimed to determine the frequency of smoking and to explore factors associated with the smoking habits of female students at a dental hygiene school in Japan. Questionnaires regarding cigarette smoking were given to 168 female students. The response rate was 97.6%. The prevalence of smoking, including current and occasional smokers, was 20.3%. Among family members, only the smoking status of their mother significantly influenced the smoking status of the students. The odds ratio for smoking among dental hygiene students whose mothers were smokers in comparison to students whose mothers were not smokers was 5.1 (95% confidence interval 2.1-12.2, p=0.000). Decision tree analysis showed that the smoking habit of dental hygiene students was correlated with their mothers’ smoking history, as well as the smoking status of junior high school teachers, the smoking habits of close friends and a history of participating in a smoking prevention program when in elementary school. The increased smoking rate of young females, including dental hygienists, is a growing problem in Japan. The smoking statuses of dental hygiene students might be closely influenced by their mothers' smoking status.
Phenolics: Occurrence and Immunochemical Detection in Environment and Food
Authors: Meulenberg Eline P.
Published: January 2009

Phenolic compounds may be of natural or anthropogenic origin and be present in the environment as well as in food. They comprise a large and diverse group of compounds that may be either beneficial or harmful for consumers. In this review first a non-exhausting overview of interesting phenolics is given, in particular with regards to their presence in environment and food. For some of these compounds, beneficial, toxicological and/or optionally endocrine disrupting activities will be presented. Further, immunochemical detection and/or isolation methods developed will be discussed, including advantages and disadvantages thereof in comparison with conventional analytical methods such as HPLC, GC, MS. A short overview of new sensor-like methods will also be included for present and future application.
An Energy-Aware Routing Protocol in Wireless Sensor Networks
Authors: Liu Ming , Cao Jiannong , Chen Guihai , Wang Xiaomin
Published: January 2009

The most important issue that must be solved in designing a data gathering algorithm for wireless sensor networks (WSNS) is how to save sensor node energy while meeting the needs of applications/users. In this paper, we propose a novel energy-aware routing protocol (EAP) for a long-lived sensor network. EAP achieves a good performance in terms of lifetime by minimizing energy consumption for in-network communications and balancing the energy load among all the nodes. EAP introduces a new clustering parameter for cluster head election, which can better handle the heterogeneous energy capacities. Furthermore, it also introduces a simple but efficient approach, namely, intra-cluster coverage to cope with the area coverage problem. We use a simple temperature sensing application to evaluate the performance of EAP and results show that our protocol significantly outperforms LEACH and HEED in terms of network lifetime and the amount of data gathered.
Modeling Impact-induced Failure of Polysilicon MEMS: A Multi-scale Approach
Authors: Mariani Stefano , Ghisi Aldo , Corigliano Alberto , Zerbini Sarah
Published: January 2009

Failure of packaged polysilicon micro-electro-mechanical systems (MEMS) subjected to impacts involves phenomena occurring at several length-scales. In this paper we present a multi-scale finite element approach to properly allow for: (i) the propagation of stress waves inside the package; (ii) the dynamics of the whole MEMS; (iii) the spreading of micro-cracking in the failing part(s) of the sensor. Through Monte Carlo simulations, some effects of polysilicon micro-structure on the failure mode are elucidated.
Balancing role of nitric oxide in complement‐mediated activation of platelets frommCd59aandmCd59bdouble‐knockout mice
Authors: Qin Xuebin , Hu Weiguo , Song Wenping , Blair Price , Wu Gongxiong , Hu Xuemei , Song Yanli , Bauer Selena , Feelisch Martin , Leopold Jane A. , Loscalzo Joseph , Halperin Jose A.
Published: January 2009

CD59 is a membrane protein inhibitor of the membrane attack complex (MAC) of complement.mCd59knockout mice reportedly exhibit hemolytic anemia and platelet activation. This phenotype is comparable to the human hemolytic anemia known as paroxysmal nocturnal hemoglobinuria (PNH), in which platelet activation and thrombosis play a critical pathogenic role. It has long been suspected but not formally demonstrated that both complement and nitric oxide (NO) contribute to PNH thrombosis. UsingmCd59aandmCd59bdouble knockout mice (mCd59ab−/−mice) in complement sufficient (C3+/+) and deficient (C3−/−) backgrounds, we document thatmCd59ab−/−platelets are sensitive to complement‐mediated activation and provide evidence for possible in vivo platelet activation inmCd59ab−/−mice. Using a combination of L‐NAME (a NO‐synthase inhibitor) and NOC‐18 or SNAP (NO‐donors), we further demonstrate that NO regulates complement‐mediated activation of platelets. These results indicate that the thrombotic diathesis of PNH patients could be due to a combination of increased complement‐mediated platelet activation and reduced NO‐bioavailability as a consequence of hemolysis. Am. J. Hematol. 2009. © 2009 Wiley‐Liss, Inc.
A randomized controlled trial evaluating an alternative mouse or forearm support on change in median and ulnar nerve motor latency at the wrist
Authors: Conlon Craig F. , Krause Niklas , Rempel David M.
Published: January 2009

Background

The purpose of this study was to determine the effects of an alternative mouse and/or a forearm support board on nerve function at the wrist among engineers.

Methods

This randomized controlled intervention trial followed 206 engineers for 1 year. Distal motor latency (DML) at baseline and follow‐up was conducted for the median and ulnar nerves at the right wrist.

Results

One hundred fifty‐four subjects agreed to a nerve conduction study at the beginning and end of the study period. Those who received the alternative mouse had a protective effect (OR = 0.47, 95% CI 0.22–0.98) on change in the right ulnar DML. There was no significant effect on the median nerve DML. The forearm support board had no significant effect on the median or ulnar nerve DML.

Conclusions

In engineers who use a computer for more than 20 hr per week, an alternative mouse may have a protective effect for ulnar nerve function at the wrist. No protective effect of a forearm support board was found for the median nerve. Am. J. Ind. Med. 52:304–310, 2009. © 2009 Wiley‐Liss, Inc.
Mesothelioma in a worker who spun chrysotile asbestos at home during childhood
Authors: Yano Eiji , Wang Zhi‐Ming , Wang Xiao‐Rong , Wang Mian‐Zheng , Takata Ayako , Kohyama Norihiko , Suzuki Yasunosuke
Published: January 2009

Background

Malignant mesothelioma has a long latency period and more commonly found in those exposed to amphibole than chrysotile asbestos.

Method

A 35 years old asbestos worker in an asbestos textile plant in Chongqing, China, developed mesothelioma after only 4 years of employment. He was born and bred in a company residence of an asbestos plant and manually spun asbestos thread during school age. In the plant, not amphibole but only chrysotile has been used.

Results

Diagnosis of malignant mesothelioma was confirmed by comprehensive approaches including gross appearance, histology, histochemistry, and immunocytochemistry. In the lung and tumor tissues, huge number of tremolite with exceptional chrysotile was observed despite the reverse proportion in the work environment.

Discussion

Residential exposure and home spinning of asbestos seemed contributed to the early development of mesothelioma in this subject. Although only chrysotile was used and contamination of tremolite was low in the work environment, chrysotile seemed to be cleared leaving tremolite remain in the tissue.

Conclusion

Chrysotile with little contamination of tremolite can lead to early development of malignant mesothelioma when heavily exposed from childhood at a company residence with household exposure. There can be several mechanisms for tremolite to remain in the lung tissue, far exceeding chrysotile in number. Am. J. Ind. Med. 52:282–287, 2009. © 2009 Wiley‐Liss, Inc.
A scoring system for coat and tail condition in ringtailed lemurs, Lemur catta
Authors: Berg Wiebke , Jolly Alison , Rambeloarivony Hajarimanitra , Andrianome Vonjy , Rasamimanana Hantanirina
Published: January 2009

Coat condition can be influenced by a wide variety of disorders and thus provides a useful tool for noninvasive health and welfare assessments in wild and captive animals. Using Lemur catta as an exemplar, we offer a 6‐step scoring system for coat and tail condition, ranging from perfectly fluffy to half or more of body and tail being hairless. The categories are described in detail and illustrated with sample pictures from a wild population in Berenty Reserve, Madagascar. Furthermore, we elaborate on intermediate conditions and discoloration of fur. Coat condition scoring allows the comparison between years, seasons, and the effect of toxin, disease or stress. Although this system was developed for wild L. catta, we believe it can also be of value for other species. We recommend scoring coat condition in healthy wild mammal populations to give a baseline on yearly and seasonal variations vs. deteriorating health conditions or pathology. Am. J. Primatol. 71:183–190, 2009. © 2009 Wiley‐Liss, Inc.
Folinic acid–responsive seizures are identical to pyridoxine‐dependent epilepsy
Authors: Gallagher Renata C. , Van Hove Johan L. K. , Scharer Gunter , Hyland Keith , Plecko Barbara , Waters Paula J. , Mercimek‐Mahmutoglu Saadet , Stockler‐Ipsiroglu Sylvia , Salomons Gajja S. , Rosenberg Efraim H. , Struys Eduard A. , Jakobs Cornelis
Published: January 2009

Objective

Folinic acid–responsive seizures and pyridoxine‐dependent epilepsy are two treatable causes of neonatal epileptic encephalopathy. The former is diagnosed by characteristic peaks on cerebrospinal fluid (CSF) monoamine metabolite analysis; its genetic basis has remained elusive. The latter is due to α‐aminoadipic semialdehyde (α‐AASA) dehydrogenase deficiency, associated with pathogenic mutations in the ALDH7A1 (antiquitin) gene. We report two patients whose CSF showed the marker of folinic acid–responsive seizures, but who responded clinically to pyridoxine. We performed genetic and biochemical testing of samples from these patients, and seven others, to determine the relation between these two disorders.

Methods

CSF samples were analyzed for the presence of α‐AASA and pipecolic acid. DNA sequencing of the ALDH7A1 gene was performed.

Results

Both patients reported here had increased CSF α‐AASA, CSF pipecolic acid, and known or likely pathogenic mutations in the ALDH7A1 gene, consistent with α‐AASA dehydrogenase deficiency. Analysis of CSF samples from seven other anonymous individuals diagnosed with folinic acid–responsive seizures showed similar results.

Interpretation

These results demonstrate that folinic acid–responsive seizures are due to α‐AASA dehydrogenase deficiency and mutations in the ALDH7A1 gene. Thus, folinic acid–responsive seizures are identical to the major form of pyridoxine‐dependent epilepsy. We recommend consideration of treatment with both pyridoxine and folinic acid for patients with α‐AASA dehydrogenase deficiency, and consideration of a lysine restricted diet. The evaluation of patients with neonatal epileptic encephalopathy, as well as those with later‐onset seizures, should include a measurement of α‐AASA in urine to identify this likely underdiagnosed and treatable disorder. Ann Neurol 2008
Übergangsmetall‐katalysierte Diaminierung von Alkenen
Authors: de Figueiredo Renata Marcia
Published: January 2009

Als leistungsstarke Methode zum Aufbau relativ komplexer Moleküle, die eine 1,2‐Diamineinheit enthalten, haben sich neue Transformationen auf dem Gebiet der Übergangsmetall‐katalysierten Diaminierung von Alkenen erwiesen (siehe Schema). In diesem Highlight wird ein Überblick über entsprechende Methoden inklusive asymmetrischer Varianten gegeben.

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Aluminiumbasen für die hoch chemoselektive Synthese von Aryl‐ und Heteroarylaluminiumverbindungen
Authors: Wunderlich Stefan H. , Knochel Paul
Published: January 2009

O am Steuer: Vielfältige funktionalisierte (hetero)aromatische Aluminiumreagentien wurden in THF effizient über eine dirigierte Aluminierung mithilfe neuartiger, neutraler Aluminiumtrisamidbasen hergestellt. Ester‐ und Cyanfunktionen werden gut toleriert. Bemerkenswerterweise sind Donor‐Sauerstoffsubstituenten effektive dirigierende Gruppen für diese Aluminierungen. An O,S‐ und N,S‐Heterocyclen werden bei der Metallierung hohe Regioselektivitäten beobachtet.

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Nanomedicine—Challenge and Perspectives
Authors: Riehemann Kristina , Schneider Stefan W. , Luger Thomas A. , Godin Biana , Ferrari Mauro , Fuchs Harald
Published: January 2009

The application of nanotechnology concepts to medicine joins two large cross‐disciplinary fields with an unprecedented societal and economical potential arising from the natural combination of specific achievements in the respective fields. The common basis evolves from the molecular‐scale properties relevant to the two fields. Local probes and molecular imaging techniques allow surface and interface properties to be characterized on a nanometer scale at predefined locations, while chemical approaches offer the opportunity to elaborate and address surfaces, for example, for targeted drug delivery, enhanced biocompatibility, and neuroprosthetic purposes. However, concerns arise in this cross‐disciplinary area about toxicological aspects and ethical implications. This Review gives an overview of selected recent developments and applications of nanomedicine.
Palladium‐Catalyzed Substitution of Allylic Fluorides
Authors: Hazari Amaruka , Gouverneur Véronique , Brown John M.
Published: January 2009

As unusual substrates for the Tsuji–Trost allylation reaction, allylic fluorides are responsive to palladium‐catalyzed substitution. Their activity towards this reaction fits in the series OCO2Me>OBz≫F≫OAc. The classic stereoretention mechanism that involves sequential inversions does not operate in this case. Several distinct cases are considered.

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Transition‐Metal‐Catalyzed Diamination of Olefins
Authors: de Figueiredo Renata Marcia
Published: January 2009

Diaminations are a girl's best friend: New reactions in the field of transition‐metal‐catalyzed diamination of olefins provide a powerful tool for the elaboration of more complex molecules bearing the 1,2‐diamine moiety. An overview of these methods, including asymmetric versions, is given.

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High‐Purity Discrete PEG‐Oligomer Crystals Allow Structural Insight
Authors: French Alister C. , Thompson Amber L. , Davis Benjamin G.
Published: January 2009

To great (monodisperse) lengths: An improved synthesis of purer ethylene glycol (EG) oligomers allows access to 16‐ and 32‐mers pure enough for multiple incorporation, and also to the longest (48‐mer) discrete EG oligomer yet reported. The high purity enables the first crystallizations and hence the first glimpses of secondary 310‐helical PEG structures.

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