bluuebunny/crossref_metadata_2025 huggingface dataset:
An empirical comparison of methods for analyzing correlated data from a discrete choice survey to elicit patient preference for colorectal cancer screening
Authors: Cheng Ji , Pullenayegum Eleanor , Marshall Deborah A , Marshall John K , Thabane Lehana
Published: February 2012

Background

A discrete choice experiment (DCE) is a preference survey which asks participants to make a choice among product portfolios comparing the key product characteristics by performing several choice tasks. Analyzing DCE data needs to account for within-participant correlation because choices from the same participant are likely to be similar. In this study, we empirically compared some commonly-used statistical methods for analyzing DCE data while accounting for within-participant correlation based on a survey of patient preference for colorectal cancer (CRC) screening tests conducted in Hamilton, Ontario, Canada in 2002.

Methods

A two-stage DCE design was used to investigate the impact of six attributes on participants' preferences for CRC screening test and willingness to undertake the test. We compared six models for clustered binary outcomes (logistic and probit regressions using cluster-robust standard error (SE), random-effects and generalized estimating equation approaches) and three models for clustered nominal outcomes (multinomial logistic and probit regressions with cluster-robust SE and random-effects multinomial logistic model). We also fitted a bivariate probit model with cluster-robust SE treating the choices from two stages as two correlated binary outcomes. The rank of relative importance between attributes and the estimates of
β
coefficient within attributes were used to assess the model robustness.

Results

In total 468 participants with each completing 10 choices were analyzed. Similar results were reported for the rank of relative importance and
β
coefficients across models for stage-one data on evaluating participants' preferences for the test. The six attributes ranked from high to low as follows: cost, specificity, process, sensitivity, preparation and pain. However, the results differed across models for stage-two data on evaluating participants' willingness to undertake the tests. Little within-patient correlation (ICC ≈ 0) was found in stage-one data, but substantial within-patient correlation existed (ICC = 0.659) in stage-two data.

Conclusions

When small clustering effect presented in DCE data, results remained robust across statistical models. However, results varied when larger clustering effect presented. Therefore, it is important to assess the robustness of the estimates via sensitivity analysis using different models for analyzing clustered data from DCE studies.
Increased prevalence of methicillin-resistant Staphylococcus aureus nasal colonization in household contacts of children with community acquired disease
Authors: Rafee Yaseen , Abdel-Haq Nahed , Asmar Basim , Salimnia Tanaz , Pharm Celine Vidaillac , Rybak Pharm Michael J , Amjad Muhammad
Published: February 2012

Background

To measure Methicillin-resistant Staphylococcus aureus (MRSA) nasal colonization prevalence in household contacts of children with current community associated (CA)-MRSA infections (study group) in comparison with a group of household contacts of children without suspected Staphylococcus aureus infection (a control group).

Methods

This is a cross sectional study. Cultures of the anterior nares were taken. Relatedness of isolated strains was tested using pulse field gel electrophoresis (PFGE).

Results

The prevalence of MRSA colonization in the study group was significantly higher than in the control group (18/77 (23%) vs 3/77 (3.9%); p ≤ 0.001). The prevalence of SA colonization was 28/77 (36%) in the study group and 16/77 (21%) in the control group (p = 0.032). The prevalence of SA nasal colonization among patients was 6/24 (25%); one with methicillin-susceptible S. aureus (MSSA) and 5 with MRSA. In the study (patient) group, 14/24 (58%) families had at least one household member who was colonized with MRSA compared to 2/29 (6.9%) in the control group (p = 0.001). Of 69 total isolates tested by PFGE, 40 (58%) were related to USA300. Panton-Valetine leukocidin (PVL) genes were detected in 30/52 (58%) tested isolates. Among the families with ≥1 contact colonized with MRSA, similar PFGE profiles were found between the index patient and a contact in 10/14 families.

Conclusions

Prevalence of asymptomatic nasal carriage of MRSA is higher among household contacts of patients with CA-MRSA disease than control group. Decolonizing such carriers may help prevent recurrent CA-MRSA infections.
Study protocol for the recruitment of female sex workers and their non-commercial partners into couple-based HIV research
Authors: Syvertsen Jennifer L , Robertson Angela M , Abramovitz Daniela , Rangel M Gudelia , Martinez Gustavo , Patterson Thomas L , Ulibarri Monica D , Vera Alicia , El-Bassel Nabila , Strathdee Steffanie A ,   Proyecto Parejas
Published: February 2012

Background

Researchers are increasingly recognizing the importance of addressing sexual and drug-related HIV risk within the context of intimate relationships rather than solely focusing on individual behaviors. Practical and effective methods are needed to recruit, screen, and enroll the high risk and hard-to-reach couples who would most benefit from HIV interventions, such as drug-using female sex workers (FSWs) and their intimate, non-commercial partners. This paper outlines a bi-national, multidisciplinary effort to develop and implement a study protocol for research on the social context and epidemiology of HIV, sexually transmitted infections (STI), and high risk behaviors among FSWs and their non-commercial male partners in Tijuana and Ciudad Juarez, Mexico. We provide an overview of our study and specifically focus on the sampling, recruitment, screening, and successful enrollment of high risk couples into a public health study in this context.

Methods/Design

We used targeted and snowball sampling to recruit couples through the female partner first and administered a primary screener to check her initial eligibility. Willing and eligible females then invited their primary male partners for couple-based screening using a couple verification screening (CVS) instrument adapted from previous studies. The CVS rechecked eligibility and separately asked each partner the same questions about their relationship to "test" if the couple was legitimate. We adapted the original protocol to consider issues of gender and power within the local cultural and socioeconomic context and expanded the question pool to create multiple versions of the CVS that were randomly administered to potential couples to determine eligibility and facilitate study enrollment.

Discussion

The protocol successfully enrolled 214 high risk couples into a multi-site public health study. This work suggests the importance of collaborating to construct a study protocol, understanding the local population and context, and drawing on multiple sources of input to determine eligibility and verify the legitimacy of relationships. We provide a practical set of tools that other researchers should find helpful in the study of high risk couples in international settings, with particular relevance to studies of FSWs and their intimate partners.
A SCN9A gene-encoded dorsal root ganglia sodium channel polymorphism associated with severe fibromyalgia
Authors: Vargas-Alarcon Gilberto , Alvarez-Leon Edith , Fragoso Jose-Manuel , Vargas Angelica , Martinez Aline , Vallejo Maite , Martinez-Lavin Manuel
Published: February 2012

Background

A consistent line of investigation suggests that autonomic nervous system dysfunction may explain the multi-system features of fibromyalgia (FM); and that FM is a sympathetically maintained neuropathic pain syndrome. Dorsal root ganglia (DRG) are key sympathetic-nociceptive short-circuit sites. Sodium channels located in DRG (particularly Nav1.7) act as molecular gatekeepers for pain detection. Nav1.7 is encoded in gene SCN9A of chromosome 2q24.3 and is predominantly expressed in the DRG pain-sensing neurons and sympathetic ganglia neurons. Several SCN9A sodium channelopathies have been recognized as the cause of rare painful dysautonomic syndromes such as paroxysmal extreme pain disorder and primary erythromelalgia. The aim of this study was to search for an association between fibromyalgia and several SCN9A sodium channels gene polymorphisms.

Methods

We studied 73 Mexican women suffering from FM and 48 age-matched women who considered themselves healthy. All participants filled out the Fibromyalgia Impact Questionnaire (FIQ). Genomic DNA from whole blood containing EDTA was extracted by standard techniques. The following SCN9A single-nucleotide polymorphisms (SNP) were determined by 5' exonuclease TaqMan assays: rs4371369; rs4387806; rs4453709; rs4597545; rs6746030; rs6754031; rs7607967; rs12620053; rs12994338; and rs13017637.

Results

The frequency of the rs6754031 polymorphism was significantly different in both groups (P = 0.036) mostly due to an absence of the GG genotype in controls. Interestingly; patients with this rs6754031 GG genotype had higher FIQ scores (median = 80; percentile 25/75 = 69/88) than patients with the GT genotype (median = 63; percentile 25/75 = 58/73; P = 0.002) and the TT genotype (median = 71; percentile 25/75 = 64/77; P = 0.001).

Conclusion

In this ethnic group; a disabling form of FM is associated to a particular SCN9A sodium channel gene variant. These preliminary results raise the possibility that some patients with severe FM may have a dorsal root ganglia sodium channelopathy.
Polysaccharides from the Chinese medicinal herb Achyranthes bidentata enhance anti-malarial immunity during Plasmodium yoelii 17XL infection in mice
Authors: Zhu Xiaotong , Pan Yanyan , Zheng Li , Cui Liwang , Cao Yaming
Published: February 2012

Background

Clinical immunity to malaria in human populations is developed after repeated exposure to malaria. Regulation and balance of host immune responses may lead to optimal immunity against malaria parasite infection. Polysaccharides (ABPS) derived from the Chinese herb ox knee Achyranthes bidentata possess immuno-modulatory functions. The aim of this study is to use the rodent malaria model Plasmodium yoelii 17XL (P. y 17XL) to examine whether pretreatment with ABPS will modulate host immunity against malaria infection and improve the outcome of the disease.

Methods

To determine whether ABPS could modulate immunity against malaria, mice were pretreated with ABPS prior to blood-stage infection by P. y 17XL. Host survival and parasitaemia were monitored daily. The effect of pretreatment on host immune responses was studied through the quantitation of cytokines, dendritic cell populations, and natural regulatory T cells (Treg).

Results

Pretreatment with ABPS prior to infection significantly extended the survival time of mice after P. y 17XL infection. At three and five days post-infection, ABPS pretreated mice developed stronger Th1 immune responses against malaria infection with the number of F4/80+CD36+ macrophages and levels of IFN-γ, TNF-α and nitric oxide being significantly higher than in the control group. More importantly, ABPS-treated mice developed more myeloid (CD11c+CD11b+) and plasmacytoid dendritic cells (CD11c+CD45R+/B220+) than control mice. ABPS pretreatment also resulted in modulated expression of MHC-II, CD86, and especially Toll-like receptor 9 by CD11c+ dendritic cells. In comparison, pretreatment with ABPS did not alter the number of natural Treg or the production of the anti-inflammatory cytokine IL-10.

Conclusion

Pretreatment with the immuno-modulatory ABPS selectively enhanced Th1 immune responses to control the proliferation of malaria parasites, and prolonged the survival of mice during subsequent malaria infection.
Improvement in the photoelectrochemical responses of PCBM/TiO2 electrode by electron irradiation
Authors: Yoo Seung Hwa , Kum Jong Min , Ali Ghafar , Heo Sung Hwan , Cho Sung Oh
Published: February 2012

The photoelectrochemical (PEC) responses of electron-irradiated [6, 6]-phenyl-C61-butyric acid methyl ester (PCBM)/TiO2 electrodes were evaluated in a PEC cell. By coating PCBM on TiO2 nanoparticle film, the light absorption of PCBM/TiO2 electrode has expanded to the visible light region and improved the PEC responses compared to bare TiO2 electrode. The PEC responses were further improved by irradiating an electron beam on PCBM/TiO2 electrodes. Compared to non-irradiated PCBM/TiO2 electrodes, electron irradiation increased the photocurrent density and the open-circuit potential of PEC cells by approximately 90% and approximately 36%, respectively at an optimum electron irradiation condition. The PEC responses are carefully evaluated correlating with the optical and electronic properties of electron-irradiated PCBM/TiO2 electrodes.
Optical and electrical properties of undoped and doped Ge nanocrystals
Authors: Das Samaresh , Aluguri Rakesh , Manna Santanu , Singha Rajkumar , Dhar Achintya , Pavesi Lorenzo , Ray Samit Kumar
Published: February 2012

Size-dependent photoluminescence characteristics from Ge nanocrystals embedded in different oxide matrices have been studied to demonstrate the light emission in the visible wavelength from quantum-confined charge carriers. On the other hand, the energy transfer mechanism between Er ions and Ge nanocrystals has been exploited to exhibit the emission in the optical fiber communication wavelength range. A broad visible electroluminescence, attributed to electron hole recombination of injected carriers in Ge nanocrystals, has been achieved. Nonvolatile flash-memory devices using Ge nanocrystal floating gates with different tunneling oxides including SiO2, Al2O3, HfO2, and variable oxide thickness [VARIOT] tunnel barrier have been fabricated. An improved charge storage characteristic with enhanced retention time has been achieved for the devices using VARIOT oxide floating gate.
Overview of enabling technologies for 3GPP LTE-advanced
Authors: Tran Thien-Toan , Shin Yoan , Shin Oh-Soon
Published: February 2012

As the long term evolution (LTE) standard comes to an end, 3rd Generation Partnership Project is discussing further evolution of the LTE to meet the international mobile telecommunications advanced requirements, which is referred to as LTE-Advanced (LTE release 10 and beyond). This article first presents the network infrastructure of the LTE-Advanced, and then provides an in-depth overview of enabling technologies from the physical layer aspects, including carrier aggregation, advanced multiple-input multiple-output (MIMO) techniques, wireless relays, enhanced inter-cell interference coordination (eICIC), and coordinated multipoint (CoMP) transmission/reception. In particular, we describe concept and principle of each technology and elaborate important technical details. Moreover, we discuss promising study items of the LTE-Advanced for further enhancement.
The embryonic leaf identity gene FUSCA3 regulates vegetative phase transitions by negatively modulating ethylene-regulated gene expression in Arabidopsis
Authors: Lumba Shelley , Tsuchiya Yuichiro , Delmas Frederic , Hezky Jodi , Provart Nicholas J , Shi Lu Qing , McCourt Peter , Gazzarrini Sonia
Published: February 2012

Background

The embryonic temporal regulator FUSCA3 (FUS3) plays major roles in the establishment of embryonic leaf identity and the regulation of developmental timing. Loss-of-function mutations of this B3 domain transcription factor result in replacement of cotyledons with leaves and precocious germination, whereas constitutive misexpression causes the conversion of leaves into cotyledon-like organs and delays vegetative and reproductive phase transitions.

Results

Herein we show that activation of FUS3 after germination dampens the expression of genes involved in the biosynthesis and response to the plant hormone ethylene, whereas a loss-of-function fus3 mutant shows many phenotypes consistent with increased ethylene signaling. This FUS3-dependent regulation of ethylene signaling also impinges on timing functions outside embryogenesis. Loss of FUS3 function results in accelerated vegetative phase change, and this is again partially dependent on functional ethylene signaling. This alteration in vegetative phase transition is dependent on both embryonic and vegetative FUS3 function, suggesting that this important transcriptional regulator controls both embryonic and vegetative developmental timing.

Conclusion

The results of this study indicate that the embryonic regulator FUS3 not only controls the embryonic-to-vegetative phase transition through hormonal (ABA/GA) regulation but also functions postembryonically to delay vegetative phase transitions by negatively modulating ethylene-regulated gene expression.
Antiviral activity of recombinant ankyrin targeted to the capsid domain of HIV-1 Gag polyprotein
Authors: Nangola Sawitree , Urvoas Agathe , Valerio-Lepiniec Marie , Khamaikawin Wannisa , Sakkhachornphop Supachai , Hong Saw-See , Boulanger Pierre , Minard Philippe , Tayapiwatana Chatchai
Published: February 2012

Background

Ankyrins are cellular mediators of a number of essential protein-protein interactions. Unlike intrabodies, ankyrins are composed of highly structured repeat modules characterized by disulfide bridge-independent folding. Artificial ankyrin molecules, designed to target viral components, might act as intracellular antiviral agents and contribute to the cellular immunity against viral pathogens such as HIV-1.

Results

A phage-displayed library of artificial ankyrins was constructed, and screened on a polyprotein made of the fused matrix and capsid domains (MA-CA) of the HIV-1 Gag precursor. An ankyrin with three modules named AnkGAG1D4 (16.5 kDa) was isolated. AnkGAG1D4 and MA-CA formed a protein complex with a stoichiometry of 1:1 and a dissociation constant ofKd~ 1 μM, and the AnkGAG1D4 binding site was mapped to the N-terminal domain of the CA, within residues 1-110. HIV-1 production in SupT1 cells stably expressing AnkGAG1D4 in both N-myristoylated and non-N-myristoylated versions was significantly reduced compared to control cells. AnkGAG1D4 expression also reduced the production of MLV, a phylogenetically distant retrovirus. The AnkGAG1D4-mediated antiviral effect on HIV-1 was found to occur at post-integration steps, but did not involve the Gag precursor processing or cellular trafficking. Our data suggested that the lower HIV-1 progeny yields resulted from the negative interference of AnkGAG1D4-CA with the Gag assembly and budding pathway.

Conclusions

The resistance of AnkGAG1D4-expressing cells to HIV-1 suggested that the CA-targeted ankyrin AnkGAG1D4 could serve as a protein platform for the design of a novel class of intracellular inhibitors of HIV-1 assembly based on ankyrin-repeat modules.
Assertive Community Treatment for alcohol dependence (ACTAD): study protocol for a randomised controlled trial
Authors: Gilburt Helen , Burns Tom , Copello Alex , Coulton Simon , Crawford Michael , Day Ed , Deluca Paolo , Godfrey Christine , Parrott Steve , Rose Abigail K , Sinclair Julia M A , Wright Christine , Drummond Colin
Published: February 2012

Background

Alcohol dependence is a significant and costly problem in the UK yet only 6% of people a year receive treatment. Current service provision based on the treatment of acute episodes of illness and emphasising personal choice and motivation results in a small proportion of these patients engaging with alcohol treatment. There is a need for interventions targeted at the population of alcohol dependent patients who are hard to engage in conventional treatment. Assertive Community Treatment (ACT), a model of care based on assertive outreach, has been used for treating patients with severe mental illnesses and presents a promising avenue for engaging patients with primary alcohol dependence. So far there has been little research on this.

Methods/Design

In this single blind exploratory randomised controlled trial, a total of 90 alcohol dependent participants will be recruited from community addiction services. After completing a baseline assessment, they will be assigned to one of two conditions: (1) ACT plus care as usual, or (2) care as usual. Those allocated to the ACT plus care as usual will receive the same treatment that is routinely provided by services, plus a trained key worker who will provide ACT. ACT comprises intensive and assertive contact at least once a week, over 50% of contacts in the participant's home or local community, and comprehensive case management across social and health care, for a period of one year. All participants will be followed up at 6 months and 12 months to assess outcome post randomisation. The primary outcome measures will be alcohol consumption: mean drinks per drinking day and percentage of days abstinent measured by the Time Line Follow Back interview. Secondary outcome measures will include severity of alcohol dependence, alcohol related problems, motivation to change, social network involvement, quality of life, therapeutic relationship and service use. Other outcome variables are treatment engagement including completion of assessment, detoxification and aftercare.

Discussion

Results of this trial will help clarify the potential beneficial effects of ACT for people with alcohol dependence and provide information to design a definitive trial.

Trial registration number

ISRCTN: ISRCTN22775534
Hemolytic disease of the fetus and newborn caused by anti-D and anti-S alloantibodies: a case report
Authors: Yousuf Rabeya , Abdul Aziz Suria , Yusof Nurasyikin , Leong Chooi-Fun
Published: February 2012

Introduction

Hemolytic disease of the fetus and newborn is most commonly caused by anti-D alloantibody. It is usually seen in Rhesus D (RhD)-negative mothers that have been previously sensitized. We report here a case of hemolytic disease of the fetus and newborn in a newborn baby caused by anti-D and anti-S alloantibodies, born to a mother who was RhD negative, but with no previous serological evidence of RhD alloimmunization.

Case presentation

A one-day-old Chinese baby boy was born to a mother who was group A RhD negative. The baby was jaundiced with hyperbilirubinemia, but with no evidence of infection. His blood group was group A RhD positive, his direct Coombs' test result was positive and red cell elution studies demonstrated the presence of anti-D and anti-S alloantibodies. Investigations performed on the maternal blood during the 22 weeks of gestation showed the presence of anti-S antibodies only. Repeat investigations performed post-natally showed the presence of similar antibodies as in the newborn and an anti-D titer of 1:32 (0.25 IU/mL), which was significant. A diagnosis of hemolytic disease of the fetus and newborn secondary to anti-D and anti-S was made. The baby was treated with phototherapy and close monitoring. He was discharged well after five days of phototherapy.

Conclusions

This case illustrates the possibility of an anamnestic response of allo-anti-D from previous sensitization in a RhD-negative mother, or the development of anti-D in mid-trimester. Thus, it highlights the importance of thorough antenatal ABO, RhD blood grouping and antibody screening, and if necessary, antibody identification and regular monitoring of antibody screening and antibody levels for prevention or early detection of hemolytic disease of the fetus and newborn, especially in cases of mothers with clinically significant red cell alloantibody.
Replicated associations of TNFAIP3, TNIP1 and ETS1 with systemic lupus erythematosus in a southwestern Chinese population
Authors: Zhong Hua , Li Xiao-lan , Li Ming , Hao Li-xia , Chen Rong-wei , Xiang Kun , Qi Xue-bin , Ma Runlin Z , Su Bing
Published: February 2012

Introduction

Recent genome-wide and candidate gene association studies in large numbers of systemic lupus erythematosus (SLE) patients have suggested approximately 30 susceptibility genes. These genes are involved in three types of biological processes, including immune complex processing, toll-like receptor function and type I interferon production, and immune signal transduction in lymphocytes, and they may contribute to the pathogenesis of SLE. To better understand the genetic risk factors of SLE, we investigated the associations of seven SLE susceptibility genes in a Chinese population, including FCGR3A, FCGR2A, TNFAIP3, TLR9, TREX1, ETS1 and TNIP1.

Methods

A total of 20 SNPs spanning the seven SLE susceptibility genes were genotyped in a sample of 564 unrelated SLE patients and 504 unrelated healthy controls recruited from Yunnan, southwestern China. The associations of SNPs with SLE were assessed by statistical analysis.

Results

Five SNPs in two genes (TNFAIP3 and ETS1) were significantly associated with SLE (corrected P values ranging from 0.03 to 5.5 × 10-7). Through stratified analysis, TNFAIP3 and ETS1 showed significant associations with multiple SLE subphenotypes (such as malar rash, arthritis, hematologic disorder and antinuclear antibody) while TNIP1 just showed relatively weak association with onset age. The associations of the SNPs in the other four genes were not replicated.

Conclusions

The replication analysis indicates that TNFAIP3, ETS1 and TNIP1 are probably common susceptibility genes for SLE in Chinese populations, and they may contribute to the pathogenesis of multiple SLE subphenotypes.
Erectile dysfunction is frequent in systemic sclerosis and associated with severe disease: a study of the EULAR Scleroderma Trial and Research group
Authors: Foocharoen Chingching , Tyndall Alan , Hachulla Eric , Rosato Edoardo , Allanore Yannick , Farge-Bancel Dominique , Caramaschi Paola , Airó Paolo , Nikolaevna Starovojtova M , Pereira da Silva José António , Stamenkovic Bojana , Riemekasten Gabriela , Rednic Simona , Sibilia Jean , Wiland Piotr , Tarner Ingo , Smith Vanessa , Onken Anna T , Abdel Atty Mohamed Walid Ahmed , Distler Oliver , Morović-Vergles Jadranka , Himsel Andrea , de la Peña Lefebvre Paloma Garcia , Hügle Thomas , Walker Ulrich A
Published: February 2012

Introduction

Erectile dysfunction (ED) is common in men with systemic sclerosis (SSc) but the demographics, risk factors and treatment coverage for ED are not well known.

Method

This study was carried out prospectively in the multinational EULAR Scleroderma Trial and Research database by amending the electronic data-entry system with the International Index of Erectile Function-5 and items related to ED risk factors and treatment. Centres participating in this EULAR Scleroderma Trial and Research substudy were asked to recruit patients consecutively.

Results

Of the 130 men studied, only 23 (17.7%) had a normal International Index of Erectile Function-5 score. Thirty-eight per cent of all participants had severe ED (International Index of Erectile Function-5 score ≤ 7). Men with ED were significantly older than subjects without ED (54.8 years vs. 43.3 years, P < 0.001) and more frequently had simultaneous non-SSc-related risk factors such as alcohol consumption. In 82% of SSc patients, the onset of ED was after the manifestation of the first non-Raynaud's symptom (median delay 4.1 years). ED was associated with severe cutaneous, muscular or renal involvement of SSc, elevated pulmonary pressures and restrictive lung disease. ED was treated in only 27.8% of men. The most common treatment was sildenafil, whose efficacy is not established in ED of SSc patients.

Conclusions

Severe ED is a common and early problem in men with SSc. Physicians should address modifiable risk factors actively. More research into the pathophysiology, longitudinal development, treatment and psychosocial impact of ED is needed.
Solvothermal Synthesis and Magnetic Properties of La-Substituted Barium Ferrite
Authors: Zheng Xiaoying , Du Yunchen , Wang Yu , Cui Ying , He Xiong , Han Xijiang
Published: February 2012

A series of La-substituted barium ferrite (Ba1−xLaxFe12O19, 0 ≤ x ≤ 0.2) have been prepared through a solvothermal route and routine high-temperature calcination. Compared with some existing techniques, this solvothermal method shows some advantages in simplicity and low cost, and the obtained products exhibit high-purity crystalline phase, small particle size, and strong magnetic properties.
Inorganic Frameworks Made by Combining Paddle-wheel Diruthenium(II, III) Complexes and Polyoxometalate Clusters
Authors: Sawada Yuki , Yamamoto Yuma , Nishio Masaki , Kosaka Wataru , Hayashi Yoshihito , Miyasaka Hitoshi
Published: February 2012

The reactions of a pivalate-bridged paddle-wheel diruthenium(II, III) complex, [Ru2II,III(piv)4(THF)2]BF4, with two kinds of polyoxometalates (POMs), (TBA)2[Mo6O19] and (TBA)3[H3V10O28] (TBA: tetra-n-butylammonium cation), led to the formation of one- and two-dimensional inorganic frameworks composed of [–{Ru2}n–(POM)–]− repeating units with n = 1 and 2, respectively.
Phosphine-catalyzed [3 + 2] and [3 + 3] Annulations of Azomethine Imines with Ethyl 2-Butynoate
Authors: Liu Jun , Liu Honglei , Na Risong , Wang Guiyong , Li Zhen , Yu Hao , Wang Min , Zhong Jiangchun , Guo Hongchao
Published: February 2012

The phosphine-catalyzed [3 + 2] and [3 + 3] annulation reactions of azomethine imines and ethyl 2-butynoate were developed, providing 1,2-dinitrogen-containing heterocycles tetrahydropyrazolopyrazolones and tetrahydropyrazolopyridazinones in moderate to good yields.
Controlled Assembly of Ultrasmall Iron Oxide Nanoparticles on Carbon Nanotubes: Facile Preparation and Interfacially Induced Ferromagnetism
Authors: Xu Jiaoxing , Wang Ning , Guan Lunhui
Published: February 2012

Ultrasmall (<5 nm) γ-Fe2O3 nanocrystals with tunable loading density on the carbon nanotubes (CNTs) were solvothermally synthesized using bifunctional phenol as capping ligand and dually as surfactant that favored uniform attachment. With the interfacial charge transfer, the nanosize-dependently superparamagnetic γ-Fe2O3 nanoparticles transform to weak ferromagnetism at room temperature.
The voice of the patient in the Mid Staffordshire Public Inquiry: Part 1
Authors: Heyes Caron
Published: February 2012

An outline of how the Public Inquiry came about and AvMA's role as a core participant. We look at some of the evidence heard and the key themes of the Inquiry and indicate some of the issues that AvMA hope to see dealt with in the final Report. The Inquiry concluded its hearing of evidence and submissions on 1 December 2011, and the Chair is now preparing his report which is expected in June 2012. Further examination of the Report and its implications for the Health Service, and for future patient involvement and the instigation of a statutory Duty of Candour, will be published in Part 2 of this article after publication of the report.
Putting Things Right in Wales
Authors: Ferguson Anne-Louise , Braithwaite Emma
Published: February 2012

Since April 2011, concerns about treatment or care in the NHS raised by patients, their relatives or members of NHS staff have been subject to investigation under new regulations brought in by the devolved Welsh Government. The intention is ‘to do it once; do it well’ and if there is a qualifying liability in tort, to deal with any lower value claim expeditiously and economically. More importantly, lessons learned are acknowledged and shared in a drive towards ‘putting things right’ for the future. It is early days for the scheme as yet but this article sets out the general rules of engagement.
Making amends for adverse events arising during hospital care
Authors: Neale Graham
Published: February 2012

Making amends for adverse events arising during hospital care, in a manner that will satisfy most people, is difficult. In this issue of Clinical Risk, the Chief Solicitor with Welsh Health Legal Services describes the progress of the NHS Redress Scheme initiative in Wales, an important step forward. The aim of this review is to examine the manner in which errors in hospital practice are addressed for patients who desire compensation, how the issues of making amends have been managed, and how these may affect what may be regarded as a prime recompense – that of improving the quality and safety of healthcare.
Searching primary care records for predefined triggers may expose latent risks and adverse events
Authors: Bowie Paul , Halley Lyn , Gillies Jill , Houston Neil , de Wet Carl
Published: February 2012

We describe the evolving development of a trigger review process as part of a pilot national safety improvement programme, which enables primary care clinicians to rapidly search electronic patient records to identify latent risks and previously undetected adverse events.
Osteoarthritis
Authors: Hogervorst T.
Published: February 2012

Osteoarthritis is extremely common and many different causes for it have been described. One such cause is abnormal morphology of the affected joint, the hip being a good example of this. For those joints with femoroacetabular impingement (FAI) or developmental dysplasia of the hip (DDH), a link with subsequent osteoarthritis seems clear. However, far from being abnormal, these variants may be explained by evolution, certainly so for FAI, and may actually be normal rather than representing deformity or disease. The animal equivalent of FAI is coxa recta, commonly found in species that run and jump. It is rarely found in animals that climb and swim. In contrast are the animals with coxa rotunda, a perfectly spherical femoral head, and more in keeping with the coxa profunda of mankind. This article describes the evolutionary process of the human hip and its link to FAI and DDH. Do we need to worry after all?
Modeling Hydraulic Fractures in Finite Difference Simulators Using Amalgam LGR (Local Grid Refinement)
Authors: Abdelmoneim S. S. , Rabee R.. , Shehata A. M. , Aly A..
Published: February 2012

Hydraulic fracturing allows numerous, otherwise unproductive, low permeability hydrocarbon formations to be produced. The interactions between the fractures and the heterogeneous reservoir rock, however, are quite complex, which makes it quite difficult to model production from hydraulically-fractured systems. Various techniques have been applied in the simulation of hydraulically fractured wells using finite difference simulators most of these techniques are limited by the gnd dimensions and computing time and hardware restrictions. Most of the current analytical techniques assume a single rectangular shaped fracture m a single phase homogeneous reservoir, the fracture is limited to the block size and the fracture properties are adjusted using permeability multiplier. The current work demonstrates how to model these systems with a smaller grid block size which allows you to apply sensitivity to the fracture length and model the fracture with enhanced accuracy. It also allows you to study the effect of reservoir heterogeneity on the fractured well performance. It is proposed to apply amalgam LGR technique to decrease the grid size to the dimensions of the hydraulic fracture without dramatically increasing the number of gnd blocks which would cause a great increase in the computing time and the model size with no added value. This paper explains how the amalgam LGR is designed and compares between standard LGRs and the proposed design and a case study is presented from an anonymous field in Egypt to illustrate how to use this technique to model the hydraulically fractured well. The simulation model is matched to available production data by changing fracture lengths. Then the model is used to predict future response from the wells. The advantage of this technique is that it allows hydraulically fractured reservoirs to be modeled with less grid size which will lead to more realistic models and more accurate predictions: however, the most usefid application of this technique may come in the fracture modeling stage. With this tool, various fracture geometries and scenarios can be tested in the simulator, and the most economic scenarios selected and implemented. This will cause better fracture placement, and ultimately greater production.
Durability of Portland Cement with and without Metal Oxide Weighting Material in a CO2/ H2S Environment
Authors: Fakhreldin Y..
Published: February 2012

Hematite and hausmannite Ore ground are the most common material for weighting cement, it most adequately fulfills all the requirements and achieves the highest effective specific gravity, they usually dry blend with oil well cement to prepare high-density cement slurries. Cement sheath made of Portland cement and high-density additive of metal oxide such as Hematite and or hausmannite Ore ground decomposes much faster than cement sheath made of net or low Portland cement when it exposes to hydrogen sulfide (H2S) and or wet carbon dioxide (CO2) during the Well-Life. Hematite and hausmannite Ore ground's pre-densified cement sheath breaks down into many compounds through series of chemical reactions often involve an energy source that breaks apart the bonds of compounds. It decomposes into metal sulfide and or carbonate and calcium carbonate with a small concentration of iron sulfide as a result of the metal oxide and or Portland cement content sulfidation and carbonation reactions. Cement sheaths made of net, high, or low-Portland cement without high-density additive of metal oxide decomposition rate is less than cement sheath made of Portland cement with a high-density additive of metal oxide when it exposes to H2S and or CO2. H2S alone does not drastically decompose cement sheaths made of net, high, or low-Portland cement without high-density additive of metal oxide. H2S has limited impact on these cement sheath type as it reacts with iron(III) hydroxide [Fe(OH)3] in which is a part of 10% of the cement hydration products. Carbonic acid reacts with 90 % of the cement hydration products (calcium silicate hydrate and lime) and degrades cement sheath thoroughly. Despite that net cement-sheath does not drastically decompose when it exposed to H2S alone, it does when expose to CO2 alone and the decomposition rate increase in the as H2S concentration increase; unfortunately, it is not a case of if, it is a case of when cement sheaths with or without a high-density additive of metal oxide decompose due to the Carbonation and or Sulfidation reaction under wet CO2 and or sour environments. The cement sheath deterioration not only prevents well production or injection rate by reducing the inner diameter of the tubing and restrict access to the well with surveillance equipment for data acquisition but also damage the well-integrity and allow hydrocarbons along with H2S and CO2 to break through to the surface eventually. Immiscible gas injection is the worst case scenario ever, Portland cement sheath whether it contain a heavyweight additive of metal oxide or not, low-Portland or high Portland cannot sustain the acid gas, and it will lose its integrity. These wells have to fail in a short period due to the cement sheath deterioration. This paper discusses the durability of different oil well cement formulations under H2S / wet CO2 environments and demonstrates why some metal oxide containing cement more stable than others under sour CO2 reservoir downhole conditions.
Drilling Fluid: State of The Art and Future Trend
Authors: Apaleke Adeleye Sanmi , Al-Majed Abdulaziz , Hossain M. Enamul
Published: February 2012

In its endeavor to provide a sustainable flow of hydrocarbon energy, the Petroleum industry has been recognized by the general public as an industry that has negatively impacted the environment as a result of using either harmful materials or risky practices. This leads the industry to continuously invest in R&D to develop environmentally friendly technologies and products. For any new technology or product, the current R&D trend is toward the development of sustainable practices and expertise. Drilling fluids are necessary for drilling oil and gas wells. Unfortunately drilling fluids have become increasingly more complex in order to satisfy the various operational demands and challenges. The materials used in the process to improve the quality and functions of the drilling fluids, contaminates the subsurface and underground systems, landfills, and surrounding environment.

Due to the increasing environmental awareness and pressure from environmental agencies throughout the world, it is very important to look back to the drilling fluid technology to reassess its progress while it tries to make forward steps to improve the petroleum industry's position as an environment friendly industry. This article outlines the state-of-the-art of drilling fluids. The major types of drilling fluids, their strengths, limitations, and remedies to limitations are discussed. It also presents the current trend and the future challenges of this technology. In addition, future research guidelines are presented focusing on the development of environmentally friendly drilling fluids with zero impact on the environment. The paper concludes that future trend leads toward the development of sustainable drilling fluids.
A Model to Minimize Risk of Cement Plug failure in HPHT Conditions
Authors: Olutimehin Adekunle A , Odunuga Marilyn
Published: February 2012

Cement plugs play a central role in providing hydraulic isolation for oil and gas well integrity. They are routinely required for abandonment purposes, drilling sidetracks and wellbore remedial operations. Despite extensive industry experience from around the world, there are many cases in high-pressure, high-temperature (HPHT) wells where an otherwise straightforward cement plug operation has led to major non-productive time (NPT) resulting in escalation of overall well costs. There are a number of issues that increase risks especially when it involves placement of high-density cement slurries in HPHT wells. Downhole conditions present additional challenges, which make it difficult to do the job right the first time. Whenever a job goes wrong in these conditions there is often an impact apart from the immediate non-productive rig time. In addition to the increase in costs there are other associated impact, e.g. potential loss of downhole barrier with negative implications for safety and the environment.

Many studies and publications have highlighted the risk of unmitigated fluids contamination during placement as one of the most common causes of cement plug failure.

One service company with extensive experience operating in the North Sea has used a model that integrates design and planning combined with a structured, detail-oriented process workflow to reduce surface execution and downhole placement risks thereby increasing the chances of success. The model relies heavily on close cooperation between the service company and the operator. Following the same strategy, this model can be applied in other geographical environments with the core objective of improving quality ensuring the job is always done right the first time. Some case histories, which inspire confidence in the ability to sustain the success rate, are described in this paper.
A Case Study on Compositional Reservoir Simulation for a Large Tight Reservoir: A Detailed Road Map from Initialization and History Match to Prediction Simulation
Authors: Basioni Mahmoud , Saad Mohamed A. , Dawoud Ahmed , El Mahdi Ahmed
Published: February 2012

This paper illustrates a detailed workflow to build a compositional simulation model for a large gas-bearing with a sizable oil-rim carbonate reservoir in the Middle East. The workflow is emphasising on the importance of data gathering, validation, analysis and integration in building a sound simulation model from geological and dynamical perspective. One of the main achievements of this work was the concept behind matching the variable producing Gas-to-Oil ratio without jeoporadizing the match of other performance parameters. The key resolution to this problem is the careful setup of equilibration and fluid models.
Integrated Approach: Key to Improved Reservoir Model
Authors: Tiwari Sanhita , Sathe Swati
Published: February 2012

An integrated approach where information and analysis from each discipline like geology, seismic, petrophysics and reservoir engineering is applied to build three-dimensional (3D) geo-cellular model and finally simulating the reservoir to represent the real flow conditions leading to formulate the field development strategy.

Most of the present workflows are designed to model the clastic reservoirs integrating geological trend and statistical methods effectively. Limestone formations are highly sensitive to fluctuations in temperature, salinity and bathymetry which affect secondary porosity and permeability within the formation and thus result in randomness. Generally, in limestone the integration of geology and geo-statistics is very difficult due to lack of well defined geological trend or randomness. This difficulty is further enhanced if the wells available within the study area are few. Paper brings out how use of seismic derived porosity trend during property modeling led to a meaningful porosity model in a limestone reservoir. In absence of core based J-function data, use of log derived initial water saturation helped in deciding the rock type distribution and saturation modeling capturing the transition zone observed in wells. Classical methods like WOR & WOR derivative plots and material balance study helped in deciding the type of aquifer support and oil volume in place. The paper deals with a real case example of a carbonate reservoir in an offshore environment with around 12 MMT oil in place and 3 exploratory and around 9 development wells within the study area. Finally, with the help of a real case example, the paper brings out the critical stages where the application of integrated approach leads to an improved reservoir model which gives reasonably good estimate of the oil in place and a satisfactory history match.
A Study of the Behavior of Oil Spill from an Offshore Rig in Red Sea Region
Authors: Shehadeh M.. , Elsayed T.. , Youssef M.. , Al Ashkar G..
Published: February 2012

Oil spills due to various industries including commercial shipping and offshore platforms damage the near coastal zones, ecological life, and tourism areas. Hence, it is required in many countries to develop oil spill contingency plans in compliance with the Oil Pollution Act of 1990 (OPA) and/or the Offshore Continental Shelf Lands Act (OCSLA). Implementation of the International Convention on Oil Pollution Preparedness, Response and Co-operation (OPRC) Convention and related issues are important elements of the IMO's Integrated Technical Co-operation Programme. The risk assessment/management, development of national contingency plans, environmental sensitivity index mapping, establishment of regional and sub-regional preparedness and response systems (agreements, plans and centers) and advice on dealing with marine pollution incidents are requested. This paper presents simulation results using a simulation model for studying the behavior of oil spill from an offshore rig. The model possesses a general structure that can accommodate most of the remaining weathering processes and a number of hypothetical scenarios are simulated for Red Sea region. The results show that using simulation can improve the oil spill contingency plans to support a risk-based decision which prevents future fatal accidents.