bluuebunny/crossref_metadata_2025 huggingface dataset:
Development and validation of an International Prognostic Score of thrombosis in World Health Organization–essential thrombocythemia (IPSET-thrombosis)
Authors: Barbui Tiziano , Finazzi Guido , Carobbio Alessandra , Thiele Juergen , Passamonti Francesco , Rumi Elisa , Ruggeri Marco , Rodeghiero Francesco , Randi Maria Luigia , Bertozzi Irene , Gisslinger Heinz , Buxhofer-Ausch Veronika , De Stefano Valerio , Betti Silvia , Rambaldi Alessandro , Vannucchi Alessandro M. , Tefferi Ayalew
Published: October 2012

Accurate prediction of thrombosis in essential thrombocythemia (ET) provides the platform for prospective studies exploring preventive measures. Current risk stratification for thrombosis in ET is 2-tiered and considers low- and high-risk categories based on the respective absence or presence of either age > 60 years or history of thrombosis. In an international study of 891 patients with World Health Organization (WHO)–defined ET, we identified additional independent risk factors including cardiovascular risk factors and JAK2V617F. Accordingly, we assigned risk scores based on multivariable analysis–derived hazard ratios (HRs) to age > 60 years (HR = 1.5; 1 point), thrombosis history (HR = 1.9; 2 points), cardiovascular risk factors (HR = 1.6; 1 point), and JAK2V617F (HR = 2.0; 2 points) and subsequently devised a 3-tiered prognostic model (low-risk = < 2 points; intermediate-risk = 2 points; and high-risk = > 2 points) using a training set of 535 patients and validated the results in the remaining cohort (n = 356; internal validation set) and in an external validation set (n = 329). Considering all 3 cohorts (n = 1220), the 3-tiered new prognostic model (low-risk n = 474 vs intermediate-risk n = 471 vs high-risk n = 275), with a respective thrombosis risk of 1.03% of patients/y versus 2.35% of patients/y versus 3.56% of patients/y, outperformed the 2-tiered (low-risk 0.95% of patients/y vs high-risk 2.86% of patients/y) conventional risk stratification in predicting future vascular events.
Optimization of a direct spectrophotometric method to investigate the kinetics and inhibition of sialidases
Authors: Hayre Jasvinder Kaur , Xu Guogang , Borgianni Luisa , Taylor Garry L , Andrew Peter W , Docquier Jean-Denis , Oggioni Marco R
Published: October 2012

Backgrounds

Streptococcus pneumoniae expresses three distinct sialidases, NanA, NanB, and NanC, that are believed to be key virulence factors and thus, potential important drug targets. We previously reported that the three enzymes release different products from sialosides, but could share a common catalytic mechanism before the final step of product formation. However, the kinetic investigations of the three sialidases have not been systematically done thus far, due to the lack of an easy and steady measurement of sialidase reaction rate.

Results

In this work, we present further kinetic characterization of pneumococcal sialidases by using a direct spectrophotometric method with the chromogenic substrate p-nitrophenyl-N-acetylneuraminic acid (p- NP-Neu5Ac). Using our assay, the measured kinetic parameters of the three purified pneumococcal sialidase, NanA, NanB and NanC, were obtained and were in perfect agreement with the previously published data. The major advantage of this alternative method resides in the direct measurement of the released product, allowing to readily determine of initial reaction rates and record complete hydrolysis time courses.

Conclusion

We developed an accurate, fast and sensitive spectrophotometric method to investigate the kinetics of sialidase-catalyzed reactions. This fast, sensitive, inexpensive and accurate method could benefit the study of the kinetics and inhibition of sialidases in general.
Downregulation of Cyclophilin A by siRNA diminishes non-small cell lung cancer cell growth and metastasis via the regulation of matrix metallopeptidase 9
Authors: Qian Zhe , Zhao Xiaoting , Jiang Mei , Jia Wenyun , Zhang Chunyan , Wang Yue , Li Baolan , Yue Wentao
Published: October 2012

Background

Cyclophilin A (CypA) is a cytosolic protein possessing peptidyl-prolyl isomerase activity that was recently reported to be overexpressed in several cancers. Here, we explored the biology and molecular mechanism of CypA in non-small cell lung cancer (NSCLC).

Methods

The expression of CypA in human NSCLC cell lines was detected by real-time reverse transcription PCR. The RNA interference-mediated knockdown of CypA was established in two NSCLC cell lines (95C and A549). 239836 CypA inhibitor was also used to suppress CypA activity. Tumorigenesis was assessed based on cellular proliferation, colony formation assays, and anchorage-independent growth assays; metastasis was assessed based on wound healing and transwell assays.

Results

Suppression of CypA expression inhibited the cell growth and colony formation of A549 and 95C cells. CypA knockdown resulted in the inhibition of cell motility and invasion. Significantly, we show for the first time that CypA increased NSCLC cell invasion by regulating the activity of secreted matrix metallopeptidase 9 (MMP9). Likewise, suppression of CypA with 239836 CypA inhibitor decreased cell proliferation and MMP9 activity.

Conclusions

The suppression of CypA expression was correlated with decreased NSCLC cell tumorigenesis and metastasis.
Exercise and nutrition for head and neck cancer patients: a patient oriented, clinic-supported randomized controlled trial
Authors: Capozzi Lauren C , Lau Harold , Reimer Raylene A , McNeely Margaret , Giese-Davis Janine , Culos-Reed S Nicole
Published: October 2012

Background

Research on physical activity and nutrition interventions aimed at positively impacting symptom management, treatment-related recovery and quality of life has largely excluded head and neck (HN) cancer populations. This translates into a lack of clinical programming available for these patient populations. HN cancer patients deal with severe weight loss, with more than 70% attributed to lean muscle wasting, leading to extended recovery times, decreased quality of life (QoL), and impaired physical functioning. To date, interventions to address body composition issues have focused solely on diet, despite findings that nutritional therapy alone is insufficient to mitigate changes. A combined physical activity and nutrition intervention, that also incorporates important educational components known to positively impact behaviour change, is warranted for this population. Our pilot work suggests that there is large patient demand and clinic support from the health care professionals for a comprehensive program.

Methods/Design

Therefore, the purpose of the present study is to examine the impact and timing of a 12-week PA and nutrition intervention (either during or following treatment) for HN cancer patients on body composition, recovery, serum inflammatory markers and quality of life. In addition, we will examine the impact of a 12-week maintenance program, delivered immediately following the intervention, on adherence, patient-reported outcomes (i.e., management of both physical and psychosocial treatment-related symptoms and side-effects), as well as return to work.

Discussion

This research will facilitate advancements in patient wellness, survivorship, and autonomy, and carve the path for a physical-activity and wellness-education model that can be implemented in other cancer centers.

Trial registration

Current Controlled Trials NCT01681654
Primary glioblastoma of the cerebellum in a 19-year-old woman: a case report
Authors: El El Maaqili Moulay Rachid , Hossini Adil , El Fatemi Nizar , Gana Rachid , Saïdi Amar , Jiddane Mohammed , Bellakhdar Fouad
Published: October 2012

Introduction

Cerebellar glioblastoma is an uncommon adult lesion. The pathogeny and prognosis of cerebellar glioblastoma are still incompletely elucidated.

Case presentation

We report the case of a 19-year-old Moroccan woman. A neurologic examination revealed the presence of cerebellar signs. A diagnosis of cerebellar glioblastoma is rarely made before surgery. An encephalic computer tomography scan and magnetic resonance imaging increased the accuracy of defining the nature of the lesion. Magnetic resonance imaging showed a heterogeneously enhancing mass in the vermis and the right cerebellar hemisphere. After surgery, glioblastoma was histologically confirmed. Post-operative radiotherapy followed. The outcome of our patient was favorable after one year of follow-up.

Conclusions

We report an unusual case of cerebellar gliobastoma. Cerebellar glioblastoma multiforme should be considered in the differential diagnosis of a cerebellar mass lesion.
Oxygen deficit and H2S in hemorrhagic shock in rats
Authors: Van de Louw Andry , Haouzi Philippe
Published: October 2012

Introduction

Hemorrhagic shock induced O2 deficit triggers inflammation and multiple organ failure (MOF). Endogenous H2S has been proposed to be involved in MOF since plasma H2S concentration appears to increase in various types of shocks and to predict mortality. We tested the hypothesis that H2S increases during hemorrhagic shock associated with O2 deficit, and that enhancing H2S oxidation by hydroxocobalamin could reduce inflammation, O2 deficit or mortality.

Methods

We used a urethane anesthetized rat model, where 25 ml/kg of blood was withdrawn over 30 minutes. O2 deficit, lactic acid, tumor necrosis factor (TNF)-alpha and H2S plasma concentrations (Siegel method) were measured before and after the bleeding protocol in control animals and animals that received 140 mg/kg of hydroxocobalamin. The ability to oxidize exogenous H2S of the plasma and supernatants of the kidney and heart homogenates was determined in vitro.

Results

We found that withdrawing 25 ml/kg of blood led to an average oxygen deficit of 122 ± 23 ml/kg. This O2 deficit was correlated with an increase in the blood lactic acid concentration and mortality. However, the low level of absorbance of the plasma at 670 nm (A670), after adding N, N-Dimethyl-p-phenylenediamine, that is, the method used for H2S determination in previous studies, did not reflect the presence of H2S, but was a marker of plasma turbidity. There was no difference in plasmatic A670 before and after the bleeding protocol, despite the large oxygen deficit. The plasma sampled at the end of bleeding maintained a very large ability to oxidize exogenous H2S (high μM), as did the homogenates of hearts and kidneys harvested just after death. Hydroxocobalamin concentrations increased in the blood in the μM range in the vitamin B12 group, and enhanced the ability of plasma and kidneys to oxidize H2S. Yet, the survival rate, O2 deficit, H2S plasma concentration, blood lactic acid and TNF-alpha levels were not different from the control group.

Conclusions

In the presence of a large O2 deficit, H2S did not increase in the blood in a rat model of untreated hemorrhagic shock. Hydroxocobalamin, while effective against H2S in vitro, did not affect the hemodynamic profile or outcome in our model.
Effect of condom-use measures in predicting sexually transmitted diseases: variation by individual and contextual factors of sexual risk
Authors: Zhou Y , Li X , Yang H , Hong Y , Fang X , Wang B , Stanton B
Published: October 2012

Inconsistent findings in the global literature regarding the effectiveness of condom use against sexually transmitted diseases (STDs) may result from variations in the measurement of condom use. In this study, we assess the sensitivity and specificity of six condom-use measures in predicting STD infection, and assess the difference in sensitivity and specificity by type of sexual partner (clients versus stable partners), type of STD, ethnicity (Han versus non-Han), years of formal schooling (≤6 versus >6 years) and level of risk of STD exposure (high versus low). Cross-sectional data were obtained from 454 female sex workers (FSWs) in Guangxi, China. Measurements of condom use were created along types of use (any use, consistent use, correct use, or the combination of consistent and correct use) and periods of recall (life time, last month or recent three sexual episodes). Measures of consistent use had higher sensitivity and lower specificity than measures of any use in predicting STDs among FSWs, regardless of the recall period and type of sexual partner. Incorporating correct use improved the measures of consistent use. Measures of consistent use and the combination of consistent and correct use demonstrated high sensitivity in predicting particular STDs. They showed higher sensitivity in predicting STDs among FSWs who reported higher risk for STD exposure than among FSWs who reported lower risk of exposure to STDs. In conclusion, the findings suggest the superiority of consistent use and correct use of condoms in predicting STD infection. The findings also underscore the importance of considering the context of sexual risk such as type of sexual partner and risk of exposure to STD infection when we measure condom use. Future studies of condom effectiveness should collect and quantify these contextual and individual factors among the target population.
Discrepancies in diagnosis of incident HIV infection between antibody- and DNA-based tests in a phase III prevention trial in southern Africa
Authors: Montgomery E T , van der Pol B , van der Straten A , Ramjee G , de Bruyn G , Chipato T , Blanchard K , Padian N S ,   MIRA Team
Published: October 2012

Dried blood spots (DBS) are widely used to test for HIV in a variety of research and service delivery settings; however, uniform guidelines regarding collection, storage and DNA extraction processes have neither been developed nor evaluated. Previously published reports suggested DBS may be stored at room temperature for up to 60 days, and intensive stability tests have shown that DBS can withstand high temperatures, humidity and freeze–thawing. During the implementation of a large randomized controlled trial (RCT) in southern Africa, with HIV acquisition as the primary endpoint, we observed 65 instances when DBS samples collected from the same day as a positive HIV antibody test yielded negative DNA polymerase chain reaction (PCR) results. The source of this discrepancy may have been due to inadequate specimen volume, filter paper or DNA extraction procedures, but were most likely due to storage conditions that have been reported as acceptable in other settings.
The outcome of treatment of early syphilis with different benzathine penicillin regimens in HIV-infected and -uninfected patients
Authors: Cousins DE , Taylor M , Lee V
Published: October 2012

The evolution of treatment guidelines for early syphilis to single-dose benzathine penicillin regardless of HIV status has been controversial in the UK. We describe the treatment response in patients treated by current and previous regimens of benzathine penicillin for early syphilis. We found no difference in treatment efficacy between single-dose benzathine and previously recommended benzathine treatment courses in HIV co-infected patients. HIV-positive status did alter treatment efficacy as evidenced by increased serological cure rates at 12 months, although this was not statistically significant. This may be due to the loss to follow-up in HIV-negative patients. HIV-infected patients were increasingly likely to be re-infected with syphilis compared to HIV-negative patients. Our findings also justify the screening of HIV patients with syphilis serology at each routine HIV follow-up.
Eosinophilia: clinical significance in HIV-infected individuals
Authors: Sivaram M , White A , Radcliffe K W
Published: October 2012

This study was conducted to determine the relationship between eosinophilia and parasitic infection in HIV-infected individuals. HIV-positive patients attending an HIV clinic in Birmingham were recruited and classified as either eosinophilic (>400 eosinophils/mm3) or non-eosinophilic. A demographic and parasitic risk history was taken and clinical examination was performed. Urine and stool were examined for parasites, and blood samples taken for parasite serology. A total of 266 patients (96 eosinophilic and 170 non-eosinophilic) were recruited. Of 64 eosinophilic patients who had a stool examination, one (1.6%) was positive for both Strongyloides larvae and schistosomal eggs. Urine microscopy was negative in the 245 patients (88 eosinophilic, 157 non-eosinophilic) from whom a sample was available. Two hundred and sixty-three patients underwent serological investigation (96 eosinophilic and 167 non-eosinophilic): 13 (4.9%) were positive for schistosomiasis and three (1.1%) positive for Strongyloides. A significant association between eosinophilia and positive schistosomal serology was found ( P = 0.003): 11 (10.5%) were eosinophilic patients, while only four (2.3%) were non-eosinophilic patients. Eosinophilia was associated with a low nadir CD4 count ( P = 0.021) and prior AIDS-defining illness ( P = 0.041). In all, 7.8% of patients from a developing country and 5.3% of patients from a developed country with a travel history had positive parasitic serology. Eosinophilia in HIV-infected patients was significantly associated with positive serology for schistosomiasis, low nadir CD4 count and prior AIDS-defining illness. Geographical exposure is also an important determinant of positive parasitic serology.
Testicular microlithiasis: is it significant?
Authors: Mullooly C , Hickerton B , Weston R , Woolley P D
Published: October 2012

Previously considered to be a benign finding on scrotal ultrasonography, testicular microlithiasis (TM) is now recognized as a condition associated with the development of testicular neoplasia. Despite this the management of TM remains unclear. We review the evidence for this association and suggested management strategies.
A community-based study to examine the effect of a youth HIV prevention programme in South Africa
Authors: Peltzer K , Ramlagan S , Chirinda W , Mlambo G , Mchunu G
Published: October 2012

The aim of this study was to examine the relationships among changes in self-reported HIV and sexually transmitted infection (STI) and exposure to the loveLife youth HIV prevention programmes. A cross-sectional population-based household survey was conducted using a multistage stratified cluster sampling approach. The total sample included 3123 participants, aged 18–24, 54.6% men and 45.4% women, from four provinces (Eastern Cape, Gauteng, KwaZulu-Natal and Mpumalanga). Results indicate a self-reported STI past-year prevalence of 2.6%, experienced genital sores or ulcers in the past year prevalence of 3.9% and an HIV self-reported prevalence of 7.4%. In multivariable analyses it was found that knowing a person living with HIV and a person who has died from AIDS, lower education, having had two or more sexual partners in the past year, not having talked with a partner about condom use, difficulty of getting condoms and not having been male circumcised were associated with having been diagnosed with an STI in the past 12 months and/or HIV. Face-to-face and multimedia youth HIV prevention programmes had limited effect.
A presentation of penile Mondor's disease
Authors: Rowe M , Depraetere K
Published: October 2012

Mondor's disease can manifest itself in the penile dorsal vein. It is a rare complaint with a quoted incidence of 1.39%. We report a case of a 41-year-old man who has sex with men (MSM), who presented with penile swelling and painful erections following intensive and vigorous sexual activity. He was found to have a thrombosis of the penile dorsal veins. He was managed with non-steroidal anti-inflammatory drugs and sexual abstinence and his symptoms resolved in the following two weeks. Practitioners need to beware of Mondor's disease as a differential diagnosis in the presence of penile swelling and not underestimate the anxiety it can cause the patient.
Recurrent vulval ulceration: could it be Behçet's disease?
Authors: Patel S , Prime K
Published: October 2012

This report describes a young black Caribbean woman with a three-year history of recurrent genital ulceration initially diagnosed as genital herpes. This diagnosis had been made clinically by the general practitioner but never confirmed on culture or nucleic acid amplification testing; sequential treatment with aciclovir and famciclovir over a four-month period did not alleviate her genital symptoms. Presentation to our genitourinary (GU) medicine clinic identified painful aphthous genital and oral ulcers, erythema nodosum bilaterally and a history of eye irritation. A clinical diagnosis of Behçet's disease was made. Treatment with hydrocortisone mouth pellets and dermovate ointment was initiated in addition to dermatology and ophthalmology referral. This report reminds clinicians to consider alternative diagnoses in clinical practice when faced with patients who are resistant to treatment. It also highlights the importance of recognizing systemic disease and maintaining a holistic approach when treating patients.
Olympic outreach: testing for sexually transmitted infections in construction workers
Authors: Shanmugaratnam S , Horne P , Coyne K M
Published: October 2012

Concerns have been voiced in the national press that the surge in migrant construction workers leading up to the 2012 Olympics Games would increase the levels of sexual ill health in East London. Between 2009 and 2011, we sent a sexual health outreach team to the Olympic Park and Village. A total of 614 clients were tested, of whom 91% were men and 46% reported English/Scottish/Welsh ethnicity. The age range was 17–73 years and median age 30 years. Reported sexual risk factors were low, including use of commercial sex workers. Prevalence of sexually transmitted infections was low, with Chlamydia trachomatis found in 20 clients (3%), and hepatitis B diagnosed in one client. This study, although small, did not support the image of construction workers presenting a higher than average sexual health risk.
Management of acute poststroke blood pressure and detection of atrial fibrillation: a postal questionnaire of UK stroke physicians’ current clinical practice
Authors: O'brien R E , Lees K R
Published: October 2012

The aim of this study was to determine the current clinical practice of UK stroke physicians with regard to the early management of blood pressure (BP) and arrhythmia detection following acute stroke. Postal service evaluation questionnaires were sent to the lead physicians for stroke in UK hospitals. Hospitals were identified by their inclusion in the 2008 Scottish Stroke Care Audit and the 2006 Royal College of Physicians Sentinel Stroke Audit. A total of 259 questionnaires were sent with a 33% response rate. Current practice regarding acute post-stroke BP management varied considerably. Approximately one-third of respondents lowered systolic BP within the first 72 hours of stroke, but the majority (65%) delayed intervening for at least seven days. Most would not intervene until systolic BP exceeded 180 mmHg. Of those who intervene, the most commonly quoted target systolic BP was 160 ± 5 mmHg. Post-stroke arrhythmia investigation was similarly varied; 12-lead electrocardiogram recording was frequent, with further investigation being more individualized. Of all respondents, 87% expressed interest in participating in future trials of complex interventions for stroke. Current practice of UK stroke physicians regarding acute BP intervention is diverse, reflecting conflicting evidence. There is interest in the stroke community for further research aiming to answer these important clinical questions.
Peat Characterization and Uptake of Nickel (II) and Cobalt (II) in a Saprist Peat Column
Authors: Asapo E.S. , Coles C.A.
Published: October 2012

In this study, fibrist and saprist sphagnum peat soils taken from a bog in Torbay, Newfoundland (Canada) were characterized. The saprist and fibrist peat soils had wet bulk densities of 0.65 and 0.60 g/cm3, respectively, and cation-exchange capacities of 70 and 45 meq/100 g, respectively. The pH of both peat soils was 4.2 and the soils were amorphous for the most part; however, the fibrist peat was more porous than the saprist peat. Results of Fourier transform infrared spectroscopy and 13carbon nuclear magnetic resonance suggested the presence of carboxylic acid, alcoholic hydroxyl, phenolic hydroxyl, amine and amide functional groups in both peats. The less reported amine and amide groups may have been observed because non-destructive characterization techniques were employed. The saprist peat was studied as an Ni2+ and Co2+ adsorbent in a vertical downflow fixed-bed column and at the end of each column experiment, metal ions in the upper layer of the peat were desorbed with HCl. The metal sorption capacity of the saprist peat increased with decreasing flow rate and overall the sorption capacity of Ni2+ was two times greater than the sorption capacity of Co2+. Ni2+ may have been retained by a combination of ion exchange and complexation, while Co2+ may have been retained only by complexation.
Ca–Mg-Doped Surface-Modified Nano-Sized Ferrihydrite Powder Synthesized by Surfactant Mediation–Precipitation Technique: A Novel Super Adsorbent for Cations
Authors: Mohapatra M. , Padhi T. , Anand S. , Mishra B.K.
Published: October 2012

In this study, high surface area (312 m2 g−1) nano-sized Ca–Mg-doped ferrihydrite was synthesized using surfactant mediation–precipitation technique. The micrographs obtained by transmission electron microscopy confirmed the particle size to be in the range of 2–5 nm. The weak crystalline nature of powder was indicated by the selected area electron diffraction pattern. Here, we studied the adsorption of four cations [Pb(II), Cd(II), Cu(II) and Co(II)] onto self-prepared nano-sized powder under various experimental conditions. The contact time data followed pseudo-second-order kinetics model for all the four cations giving regression coefficient values >0.99. The isothermic data fitted well to both Langmuir and Freundlich models for Pb(II), Cd(II) and Cu(II) with corresponding Langmuir monolayer capacities of 312.5, 333.3 and 333.3 mg g−1, respectively. For Co(II) isothermic data, only Freundlich model showed good fit and the experimentally obtained maximum loading capacity was 225 mg g−1. Desorption studies confirmed that Pb(II)- or Cd(II)-loaded adsorbent can be regenerated/reused. Studies up to five cycles of adsorption–desorption confirmed increase in uptake capacity upon regeneration. Although Cu(II)- or Co(II)-loaded adsorbents could not be regenerated, toxicity characteristic leaching procedure tests confirmed that they were safe for disposal. This is the first study of its kind to report high-loading capacities for various cations and an increase in Pb(II) or Cd(II) uptake capacities after regeneration on an adsorbent. Therefore, the prepared sample can be regarded as a super adsorbent.
Preparation and Characterization of Cobalt Aluminate Spinels CoAl2O4 Doped with Magnesium Oxide
Authors: Azer Christine , Ramadan Adham R. , Ghaly Gehane , Ragai Jehane
Published: October 2012

Cobalt aluminate spinels were prepared from cobalt and aluminium nitrate solutions using sol–gel synthesis route by ammonium hydroxide precipitation. The gels were dried at 75°C, doped with different amounts of magnesium nitrate, and then calcined for 3 h at 650°C. Sample characterization was carried out by infrared spectroscopy, X-ray diffraction, scanning electron microscopy, nitrogen adsorption studies, thermogravimetry and by determining acid–base properties. This was carried out with the objective of elucidating the effect, if any, of the presence of the dopant on the spinel structure and properties. The spinel structure was clearly exhibited in all of the prepared samples which were predominantly mesoporous. None of the samples showed any acidic properties, i.e. they exhibited only basic properties. We found that doping with Mg resulted in a slightly increased disorder of cation distribution for those samples doped with higher amounts of Mg. Doping also led to a general increase in surface areas and the development of larger pores, as well as larger content of chemisorbed water.
Adsorptive Removal of Cationic Dyes from Aqueous Solutions Using Graphite Oxide
Authors: Jin Qian-Qian , Zhu Xiao-Hua , Xing Xiang-Ying , Ren Tie-Zhen
Published: October 2012

In this study, graphite oxide (GO) was prepared by a simple one-pot treatment method and used as an adsorbent for removing cationic dyes, methylene blue (MB), crystal violet (CV) and rhodamine B (RhB) from aqueous solution of different initial concentrations. We found that an increase in initial dye concentration favoured adsorption. The adsorption kinetic process fits to the pseudo-second-order equation. When compared with the expanded graphite, GO exhibits a high adsorption capability on non-acid dye molecules, with the adsorption capacities of 199.2, 195.4 and 154.8 mg·g−1 for MB, CV and RhB, respectively. An analysis of the results of UV–Vis spectra suggested that the adsorbed dye molecules represent a different form of aggregation. Meanwhile, the layered graphene structure and surface oxygen functional groups play an important role in adsorption capability.
Wind Turbine Blade Design Review
Authors: Schubel P.J. , Crossley R.J.
Published: October 2012

A detailed review of the current state-of-art for wind turbine blade design is presented, including theoretical maximum efficiency, propulsion, practical efficiency, HAWT blade design, and blade loads. The review provides a complete picture of wind turbine blade design and shows the dominance of modern turbines almost exclusive use of horizontal axis rotors. The aerodynamic design principles for a modern wind turbine blade are detailed, including blade plan shape/quantity, aerofoil selection and optimal attack angles. A detailed review of design loads on wind turbine blades is offered, describing aerodynamic, gravitational, centrifugal, gyroscopic and operational conditions.
Modelling Passive Yawing Motion of Horizontal Axis Small Wind Turbine: Derivation of New Simplified Equation for Maximum Yaw Rate
Authors: Watanabe Fumihito , Takahashi Toru , Tokuyama Hideki , Nishizawa Yoshifumi , Ushiyama Izumi
Published: October 2012

A large number of small wind turbines are installed in an urban area or on a rooftop where they experience sudden changes of wind speed and wind direction. For small wind turbines, the yawing load is one of the important design drivers because of its severity. Typically, a passive yaw system using a tail fin is employed for these small wind turbines. IEC61400-2 ed.2 provides a simplified equation for the maximum yaw angular velocity, or yaw rate, for use in estimating the yawing load. However, it is unclear whether this yaw rate considers the sudden change of wind direction. Furthermore, this simplified equation of yaw rate is only function of a rotor radius.

In this paper, in order to consider the sudden change of wind direction, the authors derived the theoretical equation of the yawing motion to calculate yaw rate up to yaw angle of 180 degrees. This equation embraces the design variables including rotor radius, design tip speed ratio, tail fin area, and moment of inertia about the yaw axis. This theoretical equation was verified by comparing with wind tunnel test results. A number of theoretical calculations were undertaken varying all the design variables to find the relationship between the design variables and the yaw rate. Then, a new simplified equation, to calculate the yaw rate for a small wind turbine with a passive yaw system, is derived. This simplified equation is more practical than the existing IEC standard because it includes all design variables. This new equation enables to the yawing load to be estimated even for large change of wind direction.
Numerical Studies of Flow around a Wind Turbine Equipped with a Flanged-Diffuser Shroud Using an Actuator-Disk Model
Authors: Ohya Yuji , Uchida Takanori , Karasudani Takashi , Hasegawa Masaru , Kume Hiroshi
Published: October 2012

Unsteady 3-D direct numerical simulations based on the finite-difference method (FDM) were performed for flow fields around a wind turbine equipped with a flanged-diffuser shroud. Generally, it is difficult to numerically simulate the flow around rotating bodies such as the blades of wind turbines because of the unsteady flow generated by moving bodies with complex geometry. Therefore, we have devised an actuator-disk model for a wind turbine for simulating the drag and rotational forces exerted on the fluid by the wind turbine. By incorporating the body forces derived from the actuator-disk model into the external terms in the Navier-Stokes equations, the unsteady flow around a wind turbine can be simulated. The results of numerical simulations were compared with the results from wind tunnel experiments and showed good agreement for the velocity and pressure fields.
A Methodology for Updating Wind Turbine Capital Costs
Authors: Morgan Eric R. , Manwell James F. , McGowan Jon G.
Published: October 2012

Wind turbine cost models can become obsolete due a number of factors such as changes in manufacturing techniques and the price of raw materials. This paper illustrates that, in order to keep the models current, the Producer Price Index ( PPI) should be included to escalate and deescalate the costs of producing wind turbine components. The PPI is incorporated into a popular cost and scaling model developed at the National Renewable Energy Laboratory (NREL) by using the weighted averages of the PPI for each of the components of the turbine. A single PPI for the entire turbine is calculated which can be used to escalate the costs of the NREL model. The “wind turbine PPI” is then calculated for each year starting in 2002 and ending in 2010. The resulting updated turbine costs are inflated to 2010 US dollars and compared to wind turbine prices in the United States, as reported by the Lawrence Berkeley National Laboratory (LBNL). It is shown that the PPI is able to simultaneously predict the net effects of labor costs, materials prices and energy prices. The results can be used to escalate the costs stated in the NREL model or to update the costs of similar turbines across time.
Three Dimensional Simulation of the Flow Effect on the Acoustic Propagation inside Lined Duct
Authors: Taktak Mohamed , Jrad Hanen , Karra Chafik , Bentahar Mabrouk , Haddar Mohamed
Published: October 2012

The flow presents an important factor influencing the acoustic propagation inside a duct element. In this paper, a three dimensional numerical method based on the convected Helmholtz equation was used to evaluate this effect in the case of cylindrical wall - lined - wall duct element by simulating the acoustic field inside a duct element presenting an impedance discontinuity. The flow effect was evaluated for several modes and Mach numbers. A comparison between acoustic fields inside the duct for several studied cases showed that the direction and the amplitude of the flow may affect on the attenuation of the acoustic pressure inside lined ducts.
Ultra-High Strength Concrete Filled Composite Columns for Multi-Storey Building Construction
Authors: Liew J.Y. Richard , Xiong D.X.
Published: October 2012

A test programme was carried out to investigate the performance of 27 axially loaded column specimens, including 18 steel tubes infilled with ultra-high strength concrete ( UHSC) of compressive strength close to 200 MPa, 4 steel tubes infilled with normal strength concrete ( NSC) and 5 hollow steel tubes. Steel fibres were added into the UHSC to study their effect in enhancing the ductility and strength. Concrete filled double-tube columns were also investigated for potential application in multi-storey and high-rise constructions. Test results showed that UHSC filled tubular columns achieved ultra-high load-carrying capacities, but they could become brittle after the maximum load was attained. In addition, the ductility and strength of composite columns infilled with UHSC was improved by applying load only on the concrete core, adding steel fibres into the concrete core or increasing the steel contribution ratio. Comparison of test results with Eurocode 4's predictions indicates that the Eurocode 4 method could be safely extended to predict the compressive resistance of UHSC filled composite stub columns. On average, Eurocode 4 approach underestimated the resistance by 14.6% if the confinement effect was not considered and by 3.5% if the confinement effect was considered for all the specimens involving UHSC. However, to ensure sufficient ductility, it is recommended that a minimum steel contribution ratio of 0.30 or 1% steel fibres should be used. Furthermore, strength enhancement due to confinement effect should be ignored in estimating the ultimate strength of concrete filled composite columns with Class 3 steel sections.
Mitigation of Progressive Collapse in Multi-Storey Buildings
Authors: Izzuddin B.A.
Published: October 2012

This paper describes recent developments in performance-based design of multi-storey buildings against progressive collapse, where particular emphasis is given to practical implementation within the structural design process. The benefits of sudden column loss as an event-independent scenario are highlighted, and its computational merits as well as its correlation with actual extreme dynamic events are emphasised. It is proposed that the robustness limit state should be based on avoidance of failure in the upper floors above the damaged column, where it is proposed that the design envelope should be stretched from the conventional strength limit to the ductility limit so as to achieve economic design for robustness. In addressing the dynamic effects of sudden column loss, load factor approaches that have been recently proposed for use with some new usa design codes are shown to have serious shortcomings, potentially leading to unsafe estimation of dynamic amplification. These shortcomings are effectively addressed by the ductility-centred approach recently developed at imperial college london, which offers a practical multi-level assessment framework for progressive collapse under sudden column loss. Key lessons are drawn from the application of the ductility-centred approach to steel-concrete composite multi-storey buildings, where the inadequacy of prescriptive and load factor approaches is clearly demonstrated, and where the benefits of such factors as connection ductility, additional connection reinforcement, axial restraint, infill panels and rate-sensitivity are highlighted.
Recent Advances in Design of Steel and Composite Beams with Web Openings
Authors: Chung K.F.
Published: October 2012

This paper presents recent advances in the design of steel and composite beams with web openings for full integration with building services. The conventional design approaches, such as ‘ Tee Section Approach’ and ‘ Perforated Section Approach’, are provided as an introduction to the topic. The key findings of a comprehensive finite element investigation into the structural behaviour of steel beams with web openings of various shapes and sizes are presented, and a generalized design rule with a set of moment-shear interaction curves based on the finite element results is also developed for practical applications. It should be noted that based on three structural parameters, namely, the shear utilisation ratio, v, the coupled moment capacity ratio, m̄, and the coupled shear capacity ratio, v̄, the load carrying capacities of steel beams with web openings of various shapes and sizes are obtained readily through the use of the proposed moment-shear interaction curves.

Moreover, an advanced finite element study on a composite beam with a pair of large rectangular web openings is also presented, and the structural behaviour of the perforated composite beam with deformable shear connectors of different deformation characteristics is examined. It is found that both the stiffnesses and the resistances of shear connectors are very important to the load carrying capacities of the perforated composite beams. The maximum difference in the load carrying capacities of the perforated composite beams with different types of shear connectors is shown to be around 15%, reflecting the differ1ent deformation states of the composite beams at failure. Moreover, large pull-out forces are also induced in those shear connectors in the vicinity of the web openings which have been neglected in the past. As the values of these pull-out forces are found to be comparable to the shear resistances of the shear connectors adopted in the models in some cases, such forces should be considered properly in design.
Applications, Behaviour and Design of Composite Steel-Concrete Structures
Authors: Uy B.
Published: October 2012

The behaviour of composite steel-concrete beams subjected to pure flexure and the presence of flexure and shear is fairly well understood and provisions do exist in international codes of practice for their design, however in most instances the influence of the concrete slab is not included in the strength design of the composite beam in shear. Combined internal actions including the presence of torsion and flexure have also been considered of late. These actions combine to occur in edge beams and curved composite beams and thus are of significant practical interest. Of increasing interest has become the presence of axial force and flexure in composite beams. These internal actions need to be considered in the design of raking beams of stadia, elevated approach spans for bridges and interchanges and in the design of integral abutment bridges and cable stayed bridges. Furthermore, composite beams in floor systems for braced multi-storey buildings are often required to resist axial force, flexure and shear force. This paper considers the effects of the presence of axial force in conventional composite beams. The effects of different forms of axial force and flexure combinations are considered in this paper. An analytical treatment, experiments and design approaches are given in this paper which is useful for structural engineers. Furthermore research in this area is also discussed. This paper will also present the results of an extensive experimental series to study the behaviour of high performance steel sections subjected to transverse impact loads which are able to simulate either a collision or blast. The experimental program has considered both mild structural steel and stainless steel hollow sections both filled and unfilled being tested. The purpose of the tests was to identify the potential advantages of using concrete infill to increase the energy absorption capability of steel hollow sections.
Experimental and Numerical Analysis of Complex Welded Tubular DKYY-Joints
Authors: Chiew Sing-Ping , Zhang Ji-Chao , Shao Yong-Bo , Qiu Zhi-Heng
Published: October 2012

The design of multi-planar welded tubular joints is still not fully developed and very often it is not covered in design codes due to the complexity of such structures. The joint position for multi-planar tubular structures is especially critical because there are many brace members which are welded onto the chord surface. Thus, many external forces which are transferred from the braces are applied directly to the chord. Among the various multi-planar tubular joint configurations, the DKYY-joint configuration is often used in tubular space structures to form long-span roofs. However, its design, failure modes and calculations of its joint capacity are not provided in any design code. As a result, it is necessary to carry out experimental investigation and finite element numerical analysis to understand further the behavior and failure process of this type of joint. This paper details an actual practical application where a full-scale specimen is investigated experimentally in a test programme. To improve its joint capacity, reinforcements such as strengthening plates are placed inside the brace members. The chord at the joint connection is thickened to avoid local buckling. The stresses at some critical positions on the braces and on the chord are measured from strain gauges and strain rosettes to monitor the failure process and the ultimate joint capacity is determined from experimental load-displacement relationship. Experimental results show that local buckling on the chord surface at the joint is avoided effectively due to the reinforcement to the chord by increasing the chord thickness locally and placing inner circular plate inside the chord. As the stiffness of the chord at the joint is improved efficiently, failure position moves to the brace, and thus the chord is protected. Finally, finite element analysis is conducted and the numerical results are compared against those obtained from experimental measurements.
Mechanically Consistent Scaling of Composite Beam-Column Joints
Authors: Dorka Uwe E.
Published: October 2012

Today, mature beam-column joints exist for steel-concrete composite structures and their structural behaviour has been studied in many tests. Finite Elements can be used to study such regions in detail but are impractical for the analysis of a complete frame. This paper presents a scaling method that allows for the transfer of local behaviour to a higher scale analysis and back using orthogonal boundary states of a macro region as input to an FE model. To exemplify this scaling process, a sophisticated local FE model for a composite beam-column joint with welded connections is used to derive the macro constitutive law of a plane rectangular macro element, which is then applied in the analysis of a 2-storey 2-bay frame under horizontal loading. The extension to cyclic loading is discussed and so are the implications for practical frame analysis in the future.
Finite Element Analysis of Distortional Lateral Buckling of Continuous Composite Beams with Transverse Web Stiffeners
Authors: Chen Shiming , Wang Xindi
Published: October 2012

In a composite beam, transverse web stiffeners are often provided to the steel section at regular intervals along the beam span to eliminate local shear buckling as well as to reduce web distortion in the steel section. These transverse stiffeners are also found to be effective in providing intermediate lateral restraints from the stiff concrete slab to the compressive steel flange, forming a ‘discrete inverted U-frame’ action so that the resistance of the composite beam against distortional lateral buckling is significantly enhanced. In general, the load carrying capacity of a continuous composite beam depends on a number of factors such as initial imperfections, residual stresses, and material nonlinearity. A general design method to evaluate the contribution of transverse web stiffeners to the capacity of a continuous composite beam, is however yet unavailable.

This paper presents an advanced numerical investigation into the structural behaviour of composite beams under the discrete inverted U-frame action. Based on a comprehensive finite element study, the following key parameters affecting the load carrying capacity of the beam are studied: i) the flexural stiffness of the concrete slab, ii) the stiffness of the web stiffeners, iii) the ratio of the depth to thickness of the steel web, and iv) the ratio of the spacing of the web stiffeners to the beam span. It has been verified that in the presence of properly designed web stiffeners, the buckling moment resistances of composite beams will be significantly increased while the lateral deflection of the compression flanges is greatly reduced.