bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of cancer prevalence on the use of risk‐assessment cut‐off levels and the performance of mathematical models to distinguish malignant from benign adnexal masses
Authors: Daemen A. , Jurkovic D. , Van Holsbeke C. , Guerriero S. , Testa A. C. , Czekierdowski A. , Fruscio R. , Paladini D. , Neven P. , Rossi A. , Bourne T. , De Moor B. , Timmerman D.
Published: September 2010

Objective

Two logistic regression models have been developed for the characterization of adnexal masses. The goal of this prospective analysis was to see whether these models perform differently according to the prevalence of malignancy and whether the cut‐off levels of risk assessment for malignancy by the models require modification in different centers.

Methods

Centers were categorized into those with a prevalence of malignancy below 15%, between 15 and 30% and above 30%. The areas under the receiver–operating characteristics curves (AUC) were compared using bootstrapping. The optimal cut‐off level of risk assessment for malignancy was chosen per center, corresponding to the highest sensitivity level possible while still keeping a good specificity.

Results

Both models performed better in centers with a lower prevalence of malignant cases. The AUCs of the two models for centers with fewer than 15% malignant cases were 0.97 and 0.95, those of centers with 15–30% malignancy were 0.95 and 0.93 and those of centers with more than 30% malignant cases were 0.94 and 0.92. This decrease in performance was due mainly to the decrease in specificity from over 90 to around 76%. In the centers with a higher percentage of malignant cases, a sensitivity of at least 90% with a good specificity could not be obtained by choosing a different cut‐off level.

Conclusions

Overall the models performed well in all centers. The performance of the logistic regression models worsened with increasing prevalence of malignancy, due to a case mix with more borderline and complex benign masses seen in those centers. Because the cut‐off of 0.10 is optimal for all three types of center, it seems reasonable to use this cut‐off for both models in all centers. Copyright © 2011 ISUOG. Published by John Wiley & Sons, Ltd.
Small island developing states
Authors: Wong Poh Poh
Published: September 2010

In the international climate change negotiations, the Small Island Developing States (SIDS) have emerged as a credible group through the AOSIS (Alliance of Small Island States) and have called for a global temperature rise of 1.5°C above preindustrial levels. Whatever the outcomes of the negotiations, they are exacerbated by climate change and a rising sea level. Many share common characteristics of small size, high population density, limited land resources, vulnerability to natural hazards, threatened biodiversity, high dependence on tourism, and limited funds and human resources. The suggestions put forward for a research agenda for the SIDS include a comprehensive assessment of the SIDS as a group, a focused attention on oceans, increased development on renewable energy, inclusion of climate adaptation under natural disaster reduction, a strategy of ‘save some islands rather than not to have any’ for some SIDS, and large‐scale modular mangrove planting for coastal protection and adaptation to sea‐level rise. These suggestions could provide an expanded scope of adaptation for the SIDS. WIREs Clim Change 2011 2 1–6 DOI: 10.1002/wcc.84

This article is categorized under:

Vulnerability and Adaptation to Climate Change > Learning from Cases and Analogies

Climate and Development > Knowledge and Action in Development
Use of stochastic weathergenerators for precipitation downscaling
Authors: Wilks Daniel S.
Published: September 2010

Downscaling coarse‐resolution model representations of climate is a disaggregation problem, in which any number of small‐scale weather sequences can be associated with a given set of large‐scale values. Because of this intrinsic indeterminacy it is natural and logically consistent for downscaling methods to include explicitly random elements. Weather generators are stochastic models for (usually) daily weather time series, which can be used for climate‐change downscaling through appropriate adjustments to their parameters. Two main approaches for such parametric adjustments have been developed, namely changes in the daily weather generator parameters based on imposed or assumed changes in the corresponding monthly statistics, and day‐by‐day changes to the generator parameters that are controlled by daily variations in simulated atmospheric circulation. This paper reviews and compares these two methods for weather‐generator‐based downscaling, focusing on the downscaling of precipitation.WIREs Clim Change2010 1 898–907 DOI: 10.1002/wcc.85

This article is categorized under:

Assessing Impacts of Climate Change > Evaluating Future Impacts of Climate Change

Assessing Impacts of Climate Change > Representing Uncertainty
Patterns of Community Violence Exposure During Adolescence
Authors: Lambert Sharon F. , Nylund-Gibson Karen , Copeland-Linder Nikeea , Ialongo Nicholas S.
Published: September 2010

This study examined cross‐sectional and longitudinal patterns of community violence exposure and malleable predictors of these exposure patterns among a community sample of 543 urban African American early adolescents (45.3% female; mean age: 11.76). In each of grades 6, 7, and 8, latent class analyses revealed two patterns of community violence exposure: high exposure and low exposure. For the majority of participants, experiences with community violence were similar at each grade. Impulsive behavior and depressive symptoms distinguished adolescents in the high and low exposure classes in grade 6. Implications for interventions to prevent community violence exposure are discussed.
Prevalence of Genetic Testing in CHARGE Syndrome
Authors: Hartshorne Timothy S. , Stratton Kasee K. , van Ravenswaaij‐Arts Conny M. A.
Published: September 2010

Parents of 145 individuals with a clinical diagnosis of CHARGE syndrome, ages 2 to 39 years, indicated in a survey whether their child had been tested for the CHD7 mutation, which is the only gene presently known to be associated with CHARGE. More than two thirds (68%) of the affected individuals had never been gene tested. Of the 46 who had been tested, 74% tested positive for the mutation. Half (50%) of those who underwent testing did so as a part of a conference blood draw by Baylor College of Medicine in 1999. Children who were tested were significantly younger than those who had not been tested. A second group of 43 parents were informally surveyed at a conference in 2009. More than half of their children had been tested, and nearly 70% were positive for the mutation. Reasons given by these parents for testing included confirming the diagnosis and assisting research. Reasons given for not testing included lack of opportunity, no known benefit, and lack of insurance coverage.
Accuracy of Reported Family History and Effectiveness of Medical Record Requests in Genetic Counseling for Alzheimer Disease
Authors: Alexander Emily L. R. , Butler Rachel K. , Guimond Colleen , Butler Blair , Sadovnick A. Dessa
Published: September 2010

The University of British Columbia Hospital Clinic for Alzheimer Disease and Related Disorders (UBCH‐CARD) invests significant effort to obtain medical records for the confirmation of patient–reported family histories of dementia. The effectiveness of requesting these records was assessed through a review of the 275 requests made by UBCH‐CARD genetic counselors during the 24‐month period of January 1, 2005–December 31, 2006. The results were categorized according to outcome. Useful medical records were obtained from 92 (33.5%) requests: 77 (28%) records supported, and 15 (5.5%) records did not support, the patient–reported information. An additional 20 (7.5%) requests yielded only vague information. When verification was possible, patient–reported family histories of Alzheimer disease, dementia, or memory loss were accurate in 84% of cases. During the study period, almost 500 h of genetic counselor work time was spent obtaining, reviewing, and following‐up on records received. Changes made to UBCH‐CARD procedure in response to these findings are discussed.
Acute Carpal Tunnel Syndrome Secondary to Iatrogenic Hemorrhage. A Case Report
Authors: Kokosis George , Blueschke Gert , Blanton Matthew , Levinson Howard , Erdmann Detlev
Published: September 2010

Carpal tunnel syndrome is a common compression neuropathy of the median nerve. Acute carpal tunnel syndrome (aCTS) is rare, associated with a variety of conditions. In this case report we present a patient who developed aCTS and volar forearm compartment syndrome after a radial artery line placement, while receiving intravenous heparin. The patient underwent immediate forearm fasciotomy and surgical release for restoration of nerve function, which resulted in improved hand function and mild residual median nerve neuropathy. There is controversy whether to discontinue or not anticoagulation in a patient with aCTS. In our patient, heparin therapy was restarted on the second postoperative day.
A High Diffusive Model for Nanomaterials
Authors: Di Sia P , Dallacasa V
Published: September 2010

Considerable attention is today devoted to the engineering of films widely used in photocatalytic, solar energy converters, photochemical and photoelectrochemical cells, dye-sensitized solar cells (DSSCs), to optimize electronic time response following photogeneration. However, the precise nature of transport processes in these systems has remained unresolved. To investigate such aspects of carrier dynamics, we have suggested a model for the calculation of correlation functions, expressed as the Fourier transform of the frequency-dependent complex conductivity σ(ω). Results are presented for the velocity correlation functions, the mean square deviation of position and the diffusion coefficient in systems, like TiO2 and doped Si, of large interest in present devices. Fast diffusion occurs in short time intervals of the order of few collision times. Consequences for efficiency of this fast response are discussed in relation to nanostructured devices.
Nano-Floating Gate Memory Devices Composed of ZnO Thin-Film Transistors on Flexible Plastics
Authors: Park Byoungjun , Cho Kyoungah , Kim Sungsu , Kim Sangsig
Published: September 2010

Nano-floating gate memory devices were fabricated on a flexible plastic substrate by a low-temperature fabrication process. The memory characteristics of ZnO-based thin-film transistors with Al nanoparticles embedded in the gate oxides were investigated in this study. Their electron mobility was found to be 0.18 cm2/V·s and their on/off ratio was in the range of 104–105. The threshold voltages of the programmed and erased states were negligibly changed up to 103 cycles. The flexibility, memory properties, and low-temperature fabrication of the nano-floating gate memory devices described herein suggest that they have potential applications for future flexible integrated electronics.
The Investigation of Intermediate Stage of Template Etching with Metal Droplets by Wetting Angle Analysis on (001) GaAs Surface
Authors: Lyamkina AA , Dmitriev DV , Galitsyn Yu G , Kesler VG , Moshchenko SP , Toropov AI
Published: September 2010

In this work, we study metal droplets on a semiconductor surface that are the initial stage for both droplet epitaxy and local droplet etching. The distributions of droplet geometrical parameters such as height, radius and volume help to understand the droplet formation that strongly influences subsequent nanohole etching. To investigate the etching and intermixing processes, we offer a new method of wetting angle analysis. The aspect ratio that is defined as the ratio of the height to radius was used as an estimation of wetting angle which depends on the droplet material. The investigation of the wetting angle and the estimation of indium content revealed significant materials intermixing during the deposition time. AFM measurements reveal the presence of two droplet groups that is in agreement with nanohole investigations. To explain this observation, we consider arsenic evaporation and consequent change in the initial substrate. On the basis of our analysis, we suggest the model of droplet evolution and the formation of two droplet groups.
Trapping Iron Oxide into Hollow Gold Nanoparticles
Authors: Huang Chienwen , Jiang Jiechao , Muangphat Chivarat , Sun Xiankai , Hao Yaowu
Published: September 2010

Synthesis of the core/shell-structured Fe3O4/Au nanoparticles by trapping Fe3O4 inside hollow Au nanoparticles is described. The produced composite nanoparticles are strongly magnetic with their surface plasmon resonance peaks in the near infrared region (wavelength from 700 to 800 nm), combining desirable magnetic and plasmonic properties into one nanoparticle. They are particularly suitable for in vivo diagnostic and therapeutic applications. The intact Au surface provides convenient anchorage sites for attachment of targeting molecules, and the particles can be activated by both near infrared lights and magnetic fields. As more and more hollow nanoparticles become available, this synthetic method would find general applications in the fabrication of core–shell multifunctional nanostructures.
Single Walled Carbon Nanotubes Exhibit Dual-Phase Regulation to Exposed Arabidopsis Mesophyll Cells
Authors: Yuan Hengguang , Hu Shanglian , Huang Peng , Song Hua , Wang Kan , Ruan Jing , He Rong , Cui Daxiang
Published: September 2010

Herein we are the first to report that single-walled carbon nanotubes (SWCNTs) exhibit dual-phase regulation to Arabidopsis mesophyll cells exposed to different concentration of SWCNTs. The mesophyll protoplasts were prepared by enzyme digestion, and incubated with 15, 25, 50, 100 μg/ml SWCNTs for 48 h, and then were observed by optical microscopy and transmission electron microscopy, the reactive oxygen species (ROS) generation was measured. Partial protoplasts were stained with propidium iodide and 4'-6- diamidino-2-phenylindole, partial protoplasts were incubated with fluorescein isothiocyanate-labeled SWCNTs, and observed by fluorescence microscopy. Results showed that SWCNTs could traverse both the plant cell wall and cell membrane, with less than or equal to 50 μg/ml in the culture medium, SWCNTs stimulated plant cells to grow out trichome clusters on their surface, with more than 50 μg/ml SWCNTs in the culture medium, SWCNTs exhibited obvious toxic effects to the protoplasts such as increasing generation of ROS, inducing changes of protoplast morphology, changing green leaves into yellow, and inducing protoplast cells' necrosis and apoptosis. In conclusion, single walled carbon nanotubes can get through Arabidopsis mesophyll cell wall and membrane, and exhibit dose-dependent dual-phase regulation to Arabidopsis mesophyll protoplasts such as low dose stimulating cell growth, and high dose inducing cells' ROS generation, necrosis or apoptosis.
Observation of Coalescence Process of Silver Nanospheres During Shape Transformation to Nanoprisms
Authors: Yu Pyng , Huang Jane , Tang Jau
Published: September 2010

In this report, we observed the growth mechanism and the shape transformation from spherical nanoparticles (diameter ~6 nm) to triangular nanoprisms (bisector length ~100 nm). We used a simple direct chemical reduction method and provided evidences for the growth of silver nanoprisms via a coalescence process. Unlike previous reports, our method does not rely upon light, heat, or strong oxidant for the shape transformation. This transformation could be launched by fine-tuning the pH value of the silver colloidal solution. Based on our extensive examination using transmission electron microscopy, we propose a non-point initiated growth mechanism, which is a combination of coalescence and dissolution–recrystallization process during the growth of silver nanoprisms.
Mullerian duct cyst: a curable entity of male infertility. Two case reports
Authors: Kobori Yoshitomo , Sato Ryo , Ashizawa Yoshio , Yagi Hiroshi , So Shigehiro , Arai Gaku , Okada Hiroshi , Okuyama Takashi
Published: September 2010

Purpose

Mullerian duct cyst is a rudiment of a Mullerian duct in the fetal period which causes ejaculatory duct obstruction and male infertility.

Case report

We report two patients with Mullerian duct cyst that presented with low ejaculate volume, oligoasthenoteratozoospermia and azoospermia syndrome. Transrectal ultrasound (TRUS) and magnetic resonance image (MRI) revealed a midline prostatic cystic structure. In each case, we performed a TRUS guided transperineal aspiration of the cyst. Seminograms of the patients improved and one of their wives got spontaneously pregnant 3 months after the surgery.

Conclusion

We should assume the TRUS guided aspiration of Mullerian duct cyst.
Imaging of endometrial and cervical cancer
Authors: Patel Shilpa , Liyanage Sidath H. , Sahdev Anju , Rockall Andrea G. , Reznek Rodney H.
Published: September 2010

In this article we review the ever increasing role of imaging in endometrial and cervical cancer. Magnetic resonance imaging (MRI) has emerged as the most widely used technique in the management of women with gynaecological cancer. In endometrial cancer, MRI is reliable in identifying myometrial and cervical invasion and extra-uterine disease, thereby informing preoperative surgical planning. In cervical cancer, MRI plays a crucial role in distinguishing early from advanced disease, thereby stratifying patients for surgery and chemoradiation. MRI is also valuable in assessing proximal extension of cervical tumours in young women with early stage disease for feasibility of fertility preserving surgery. In both cancers, imaging is used for diagnosing nodal metastases, detection of recurrence, and dealing with complications of both the disease and treatment.
Risk Factors of Delirium after Cardiac Surgery: A Systematic Review
Authors: Koster Sandra , Hensens Ab G. , Schuurmans Marieke J. , van der Palen Job
Published: September 2010

Background: Delirium or acute confusion is a temporary mental disorder that occurs frequently among hospitalized elderly patients, but also in younger patients a delirium can develop. Patients who undergo cardiac surgery have an increased risk of developing delirium that is associated with many negative consequences. Therefore, prevention of delirium is essential. Despite the high incidence of delirium, a paucity of data on risk factors for delirium exists.

Aim: The aim of this study was to summarize the available information concerning these risk factors.

Methods: A literature research was performed using the PubMed, Cinahl, and Cochrane Library databases and was limited to the last 10 years.

Results: Our review revealed 27 risk factors; 12 predisposing and 15 precipitating factors for delirium after cardiac surgery. The most established predisposing risk factors were atrial fibrillation, cognitive impairment, depression, history of stroke, older age, and peripheral vascular disease. The most established precipitating risk factor was a red blood cell transfusion. An abnormal albumin level was reported as the most established precipitating risk factor among blood values tested. A low cardiac output and the use of an Intra Aortic Balloon Pump or inotropic medication seem to be the most relevant risk factors associated with a postoperative delirium.

Conclusion: A multifactorial risk model should be applied to identify patients at an increased risk of developing delirium following elective cardiac surgery. In these patients, if possible, preventative interventions can be taken and early recognition of delirium can be realized. This could potentially decrease the incidence of delirium and negative consequences caused by a postoperative delirium.
Pregnancy‐related acute renal failure in eastern India
Authors: Arora Nalini , Mahajan Kirti , Jana Narayan , Taraphder Abhijit
Published: September 2010

Objective

To study the causes, burden, and impact of pregnancy‐related acute renal failure (PRARF) in a low‐resource setting.

Methods

A prospective observational study of consecutive women admitted to the Seth Sukhlal Karnani Memorial Hospital, Kolkata, India, with PRARF between February 1, 2007, and May 31, 2009, was conducted. The information collected included causes and predisposing conditions leading to PRARF, clinical presentations, medical and obstetric management—including need for dialysis—and maternal outcome.

Results

The leading causes of PRARF among the 57 participants were sepsis 19 (33.3%), hemorrhage 16 (28.1%), and hypertensive disorders 15 (26.3%). The condition occurred in 11 (19.3%) cases before 20 weeks of gestation, 6 (10.5%) cases after 20 weeks of gestation, and 40 (70.2%) cases during puerperium. Most women were from rural areas and received inadequate prenatal care. Although 40 women had PRARF during puerperium, the precipitating event mostly started during the process of labor/delivery. Despite multidisciplinary care, mortality was high (28.1%); cause‐specific fatality was highest with sepsis (36.8%) and hemorrhage (25.0%). Many women who survived experienced prolonged morbidity.

Conclusions

Pregnancy‐related acute renal failure is potentially fatal but largely preventable. Universal prenatal care and greater access to emergency obstetric services, especially in rural India, could avert PRARF and its consequences.
Effect of counseling on adherence to perimenopausal hormone therapy in Slovenia
Authors: Franić Damir , Verdenik Ivan , Meden‐Vrtovec Helena
Published: September 2010

Objective

To evaluate the effect of counseling on women's adherence to hormone therapy (HT) in Slovenia following the publication of the results of the Women's Health Initiative prospective study.

Method

In this 24‐month prospective, randomized, controlled study with 125 women in early menopause, those in the study group (n = 64) attended oral presentations on menopause and HT whereas those in the control group (n = 63) did not. Data were collected from 2 questionnaires, one completed before starting HT and the other during follow‐up visits after 3, 6, 12, and 24 months. The results were analyzed according to the intention‐to‐treat principle.

Results

In the second year, an improved quality of life and friends critical of HT negatively affected adherence to HT. After 24 months, 47% of the participants in the study group and 32% in the control group were still using HT. The difference between the 2 groups in the rates of participants who discontinued HT was the same in the first than and in the last 12 months of the study (49 [76.6%] vs 15 [23.4%]).

Conclusion

Since there were no changes in discontinuation rates between the groups from one study period to the other, and a total of 15 women in each group stopped using HT in the second year of the study, the effect of the educational presentations on HT adherence was long‐term rather than temporary.
A prospective study of the factors associated with the success rate of external cephalic version for breech presentation at term
Authors: Burgos Jorge , Melchor Juan Carlos , Pijoán José Ignacio , Cobos Patricia , Fernández‐Llebrez Luis , Martínez‐Astorquiza Txantón
Published: September 2010

Objective

To determine the factors associated with the success rate of external cephalic version (ECV) for breech presentation at term.

Methods

A prospective analysis of 500 ECV maneuvers. The variables maternal age, maternal weight, body mass index, previous cesarean delivery, gestational age, parity, amount of amniotic fluid, placental location, and type of breech were studied using logistic regression analysis.

Results

The success rate of ECV was 52.2% (n = 261). The variables significantly associated with success were parity, placental location, amount of amniotic fluid, and type of breech (P < 0.05). A parity of 2 had a 3.74‐times higher probability of success than nulliparity (95% CI, 2.37–5.90); a posterior placenta increased the success rate by 2.85 times compared with an anterior placenta (95% CI, 1.87–4.36); and double footling breech presentation had a 2.77‐times higher success rate compared with a frank breech presentation (95% CI, 1.16–6.62). The area under the ROC curve showed a predictive ability of 73.6% (95% CI, 69.2%–77.9%) for these 3 variables.

Conclusion

Parity, placental location, amount of amniotic fluid, and type of breech presentation were associated with the success rate of ECV.
The role of magnetic resonance imaging in fetal renal anomalies
Authors: Gupta Prerna , Kumar Sunesh , Sharma Raju , Gadodia Ankur , Roy Kallol K. , Sharma Jai B.
Published: September 2010

Objective

To evaluate the role of magnetic resonance imaging (MRI) in fetuses with suspected renal anomalies after ultrasonography.

Methods

Eighty‐six consecutive singleton fetuses with suspected malformation after ultrasound underwent MRI at the All India Institute of Medical Sciences, New Delhi, India, from January 1, 2005, to July 31, 2008. The study group comprised 27 fetuses with suspected renal anomaly on ultrasound. The MRI findings were compared with the sonographic findings, and their impact on management was assessed. Postpartum imaging, autopsy, or surgical findings were taken as the gold standard of assessment and diagnosis.

Results

The sonographic findings in 19 (70.4%) cases were confirmed by MRI; additional findings were obtained with MRI in 7 (25.9%) cases, 3 (11.1%) of which resulted in a change in postnatal management. Additional information was also provided by MRI for 5 (50.0%) of the 10 fetuses with oligohydramnios. The MRI diagnosis was incorrect—compared with ultrasound and gold standard—for 2 (7.4%) fetuses.

Conclusion

Ultrasound is the imaging modality of choice for the diagnosis of fetal renal anomalies; fetal MRI is a useful adjunct, especially when ultrasound is inconclusive owing to oligohydramnios.
A study of 579 pregnant women with premature rupture of membranes at term
Authors: Li Kui , Wang Yanping , Li Haiyan , Yang Huixia
Published: September 2010

Objective

To determine the best management for women with premature rupture of membranes at term.

Method

In 2008, 579 women admitted to Peking University First Hospital for premature rupture of membranes (PROM) at term were allocated to one of 3 groups. Group 1 (n = 292) consisted of those whose labor began spontaneously within 12 hours of PROM; group 2 (n = 234), of those whose labor did not begin within 12 hours of PROM and were induced with oxytocin; and group 3 (n = 53), of those who accepted a cesarean delivery immediately after PROM was diagnosed. The χ2 test was used to compare the rates of intrauterine and neonatal infection in these 3 groups.

Results

Compared with the intrauterine and neonatal infection rates for group 1 (3.4% and 13.7%) and group 3 (1.9% and 3.8%), the corresponding rates were higher for group 2 (10.7% and 21.8%) (P < 0.05). In group 2, 76.5% of the women began labor within 24 hours of induction and 92.7% of these within 12 hours.

Conclusion

In women at term, induction should be performed immediately after PROM is diagnosed, as it is likely to fail when labor does not begin within 12 hours of oxytocin administration.
ON EXTRINSICALLY SYMMETRIC HYPERSURFACES OF ℍn×ℝ
Authors: CALVARUSO GIOVANNI , KOWALCZYK DANIEL , VAN DER VEKEN JOERI
Published: September 2010

Totally umbilical, semi-parallel and parallel hypersurfaces of ℍn×ℝ are completely classified. More examples arise than in the analogous study on the ambient space 𝕊n×ℝ.
‘Sexual chemistry’ before the Pill: science, industry and chemical contraceptives, 1920–1960
Authors: LÖWY ILANA
Published: September 2010

The history of contraceptives met the history of drugs long before the invention of the contraceptive pill. In the first half of the twentieth century, numerous pharmaceutical laboratories, including major ones, manufactured and marketed chemical contraceptives: jellies, suppositories, creams, powders and foams applied locally to prevent conception. Efforts to put an end to the marginal status of these products and to transform them into ‘ethical’ drugs played an important role in the development of standardized laboratory tests of efficacy of contraceptive preparations; debates on the validity of such tests; evaluation of the long-term toxicity of chemical compounds; and the rise of collaborations between activists, non-profit organizations and the pharmaceutical industry. Chemical contraceptives were initially associated with quack medicine, shady commercial practices and doubtful morality. Striving to change the status of contraceptives and to promote safe and efficient products that reduced fertility in humans shaped some of the key features of the present-day production and regulation of pharmaceuticals.
HIGH FERTILITY REGIONS IN BANGLADESH: A MARRIAGE COHORT ANALYSIS
Authors: ISLAM SABINA , ISLAM MOHAMMAD AMIRUL , PADMADAS SABU S.
Published: September 2010

Bangladesh represents one of the few countries in south Asia where the pace of fertility decline has been unprecedented over the last three decades. Although there has been significant reduction in fertility levels at the national level, regional variations continue to persist, especially in Sylhet and Chittagong where the total fertility rates are well above the country average. Using data from three consecutive Bangladesh Demographic and Health Surveys (BDHSs) this paper assesses how fertility patterns in Sylhet and Chittagong differ from the rest of Bangladesh through a marriage cohort analysis of the parity progression ratios, and examines the factors determining the transition rates to higher parity in these two regions. Three cohorts of women are identified: those married during 1965–1974, 1975–84 and 1985–94. The results show that the probability that a woman from the recent cohort in Sylhet or Chittagong who had a third birth will have a fourth birth is nearly twice that of her counterpart in other regions. Social characteristics such as education, occupation, religion and residence have no effect on fertility in Sylhet and Chittagong. Additional period-specific analyses using the 2007 BDHS data show that women in Sylhet are considerably more likely to have a third or fourth birth sooner than those in other divisions, especially Khulna. The findings call for specific family planning policy interventions in Sylhet and Chittagong ensuring gender equity, promoting female education and delaying entry into marriage and childbearing.
On a uniformly valid analytical rectilinear cascade response function
Authors: POSSON HELENE , ROGER M. , MOREAU S.
Published: September 2010

This paper extends an existing analytical model of the aeroacoustic response of a rectilinear cascade of flat-plate blades to three-dimensional incident vortical gusts, by providing closed-form expressions for the acoustic field inside the inter-blade channels, as well as for the pressure jump over the blades in subsonic flows. The extended formulation is dedicated to future implementation in a fan-broadband-noise-prediction tool. The intended applications include the modern turbofan engines, for which analytical modelling is believed to be a good alternative to more expensive numerical techniques. The initial model taken as a reference is based on the Wiener–Hopf technique. An analytical solution valid over the whole space is first derived by making an extensive use of the residue theorem. The accuracy of the model is shown by comparing with numerical predictions of benchmark configurations available in the literature. This full exact solution could be used as a reference for future assessment of numerical solvers, of linearized Euler equations for instance, in rectilinear or narrow-annulus configurations. In addition, the pressure jump is a key piece of information because it can be used as a source term in an acoustic analogy when the rectilinear-cascade model is applied to three-dimensional blade rows by resorting to a strip-theory approach. When used as such in a true rectilinear-cascade configuration, it reproduces the exact radiated field that can be derived directly. The solution is also compared to a classical single-airfoil formulation to highlight the cascade effect. This effect is found important when the blades of the cascade overlap significantly, but the cascade solution tends to the single-airfoil one as the overlap goes to zero. This suggests that both models can be used as the continuation of each other if needed.
Direct numerical simulation of oscillatory flow around a circular cylinder at low Keulegan–Carpenter number
Authors: AN HONGWEI , CHENG LIANG , ZHAO MING
Published: September 2010

The Honji instability is studied using direct numerical simulations of sinusoidal oscillatory flow around a circular cylinder. The three-dimensional Navier–Stokes equations are solved by a finite element method at a relatively small value of the Keulegan–Carpenter numberKC. The generation and subsequent development of Honji vortices are discussed over a range of frequency parameters by means of flow visualization. It is found that the spacing between Honji vortices is only weakly dependent on the frequency of oscillation, but is strongly correlated toKCbecause it is the terms within the governing equation containingKCthat dominate the three-dimensional features of the flow. An empirical relationship betweenKCand the spacing between neighbouring vortices is proposed. The three-dimensional steady streaming structure within the vortices is identified and it is found that at high frequencies the steady streaming is two-dimensional although the instantaneous flow structure is itself fully three-dimensional.
Effects of electric charge on osmotic flow across periodically arranged circular cylinders
Authors: SUGIHARA-SEKI MASAKO , AKINAGA TAKESHI , ITANO TOMOAKI
Published: September 2010

An electrostatic model is developed for osmotic flow across a layer consisting of identical circular cylinders with a fixed surface charge, aligned parallel to each other so as to form an ordered hexagonal arrangement. The expression of the osmotic reflection coefficient is derived for spherical solutes with a fixed surface charge suspended in an electrolyte, based on low-Reynolds-number hydrodynamics and a continuum, point-charge description of the electric double layers. The repulsive electrostatic interaction between the surface charges with the same sign on the solute and the cylinders is shown to increase the exclusion region of solute from the cylinder surface, which enhances the osmotic flow. Applying the present model to the study of osmotic flow across the endothelial surface glycocalyx of capillary walls has revealed that this electrostatic model could account well for the reflection coefficients measured for charged macromolecules, such as albumin, in the physiological range of charge density and ion concentration.
A numerical study of the effect of fibre stiffness on the rheology of sheared flexible fibre suspensions
Authors: WU JINGSHU , AIDUN CYRUS K.
Published: September 2010

A recently developed particle-level numerical method is used to simulate flexible fibre suspensions in Newtonian simple shear flow. In this method, the flow is computed on a fixed regular ‘lattice’ using the lattice Boltzmann method, where each solid particle, or fibre in this case, is mapped onto a Lagrangian frame moving continuously through the domain. The motion and orientation of the fibre are obtained from Newtonian dynamics equations. The effect of fibre stiffness on the rheology of flexible fibre suspensions is investigated and a relation for the relative viscosity is obtained. We show that fibre stiffness (bending ratio,BR) has a strong impact on rheology in the rangeBR< 3. The relative viscosity increases significantly asBRdecreases. These results show that the primary normal stress difference has a minimum value atBR~ 1. The primary normal stress difference for slightly deformable fibres reaches a minimum and increases significantly asBRdecreases below one. The results are explained based on Batchelor's relation for non-Brownian suspensions.
Self-consistent unstirred layers in osmotically driven flows
Authors: JENSEN K. H. , BOHR T. , BRUUS H.
Published: September 2010

It has long been recognized that the osmotic transport characteristics of membranes may be strongly influenced by the presence of unstirred concentration boundary layers adjacent to the membrane. Previous experimental as well as theoretical works have mainly focused on the case where the solutions on both sides of the membrane remain well mixed due to an external stirring mechanism. We investigate the effects of concentration boundary layers on the efficiency of osmotic pumping processes in the absence of external stirring, i.e. when all advection is provided by the osmosis itself. This case is relevant in the study of intracellular flows, e.g. in plants. For such systems, we show that no well-defined boundary-layer thickness exists and that the reduction in concentration can be estimated by a surprisingly simple mathematical relation across a wide range of geometries and Péclet numbers.
The linear stability of a Stokes layer with an imposed axial magnetic field
Authors: THOMAS CHRISTIAN , BASSOM ANDREW P. , DAVIES CHRISTOPHER
Published: September 2010

The effects of a uniform axial magnetic field directed towards an oscillating wall in a semi-infinite viscous fluid (or Stokes layer) is investigated. The linear stability and disturbance characteristics are determined using both Floquet theory and via direct numerical simulations. Neutral stability curves and critical parameters for instability are presented for a range of magnetic field strengths. Results indicate that a magnetic field directed towards the boundary wall is stabilizing, which is consistent with that found in many steady flows.
Optimal velocity and density profiles for the onset of absolute instability in jets
Authors: LESSHAFFT LUTZ , MARQUET OLIVIER
Published: September 2010

The absolute/convective character of the linear instability of axisymmetric jets is investigated for a wide range of parallel velocity and density profiles. An adjoint-based sensitivity analysis is carried out in order to maximize the absolute growth rate of jet profiles with and without density variations. It is demonstrated that jets without counterflow may display absolute instability at density ratios well above the previously assumed threshold ρjet/ρ∞ = 0.72, and even in homogeneous settings. Absolute instability is promoted by a strong velocity gradient in the low-velocity region of the shear layer, as well as by a step-like density variation near the location of maximum shear. A new efficient algorithm for the computation of the absolute instability mode is presented.
Injection augmentation of arytenoids after partial laryngectomy: case series
Authors: Ghosh A , Guss J , Ruiz C E , Quon H , Weinstein G S , Mirza N
Published: September 2010

Background:

We undertook collagen injection laryngoplasty to achieve arytenoid augmentation in patients with dysphagia and persistent aspiration following partial laryngectomy, and we evaluated the efficacy of arytenoid augmentation in aiding neoglottic closure and ensuring airway safety.

Methods:

Two patients with persistent swallowing impairment after partial laryngectomy were studied. Swallowing was evaluated using fibre-optic endoscopy, and modified barium swallow study. Collagen was then injected into the arytenoid mucosa to achieve neoglottic competence.

Results:

The patients were followed up for up to two years. Both patients showed a marked improvement in neoglottic competence, as evaluated by fibre-optic and flexible endoscopy at three-month and one-year follow-up appointments.

Conclusion:

Arytenoid augmentation by injection laryngoplasty can be considered a safe and effective surgical tool for the treatment of dysphagia with persistent aspiration following partial laryngectomy.
Aspergillus pachymeningitis mimicking nasopharyngeal carcinoma
Authors: Chan H S , Yuen H Y , Ng W K , Vlantis A C , Ahuja A T , Tong C F M , van Hasselt C A
Published: September 2010

Objectives:

We report a case of otogenic fungal pachymeningitis in a diabetic patient who presented with multiple cranial nerve palsies and nasopharyngeal swelling.

Methods:

We present a case report, we describe the investigations, management and clinical course of fungal pachymeningitis, and we present a review of the world literature on fungal and non-fungal pachymeningitis.

Results:

To our knowledge, this is the first report of fungal pachymeningitis with magnetic resonance imaging features suggestive of nasopharyngeal carcinoma. It is also the first reported case with aspergillus cultured from both a dural biopsy and the ear canal.

Conclusion:

Fungal pachymeningitis is a rare condition which may present to otorhinolaryngologists. Its clinical and radiological findings can be confused with those of nasopharyngeal carcinoma; fungal pachymeningitis should thus be included in the differential diagnosis of nasopharyngeal carcinoma.
Applying problem-based learning to otolaryngology teaching
Authors: Abou-Elhamd K A , Rashad U M , Al-Sultan A I
Published: September 2010

Objectives:

Undergraduate medical education requires ongoing improvement in order to keep pace with the changing demands of twenty-first century medical practice. Problem-based learning is increasingly being adopted in medical schools worldwide. We review its application in the specialty of ENT, and we present our experience of using this approach combined with more traditional methods.

Methods:

We introduced problem-based learning techniques into the ENT course taught to fifth-year medical students at Al-Ahsa College of Medicine, King Faisal University, Saudi Arabia. As a result, the teaching schedule included both clinical and theoretical activities. Six clinical teaching days were allowed for history-taking, examination techniques and clinical scenario discussion. Case scenarios were discussed in small group teaching sessions. Conventional methods were employed to teach audiology and ENT radiology (one three-hour session each); a three-hour simulation laboratory session and three-hour student presentation were also scheduled. In addition, students attended out-patient clinics for three days, and used multimedia facilities to learn about various otolaryngology diseases (in another three-hour session). This input was supplemented with didactic teaching in the form of 16 instructional lectures per semester (one hour per week).

Conclusion:

From our teaching experience, we believe that the application of problem-based learning to ENT teaching has resulted in a substantial increase in students' knowledge. Furthermore, students have given encouraging feedback on their experience of combined problem-based learning and conventional teaching methods.
Use of computational fluid dynamics to study the influence of the uncinate process on nasal airflow
Authors: Xiong G-X , Zhan J-M , Zuo K-J , Rong L-W , Li J-F , Xu G
Published: September 2010

Background:

Chronic rhinosinusitis is commonly treated by functional endoscopic sinus surgery involving excision of the uncinate process and opening of the osteomeatal complex.

Methods:

Computational fluid dynamics were used to compare nasal airflow after two different surgical interventions which involved opening the paranasal sinuses, excising the ethmoid sinus, and excising or preserving the uncinate process, in a cadaveric head model. Cross-sectional computed tomography images were obtained before and after the interventions. Imaging data were used to prepare computer simulations, which were used to assess the airflow characteristics of the nasal cavities and paranasal sinuses during inspiration and expiration, before and after intervention.

Results:

Significantly larger nasal cavity airflow velocity changes were apparent following the uncinate process excising procedure. Nasal cavity airflow distribution remained relatively unchanged following the uncinate process preserving procedure. There was a significantly greater increase in airflow volume following the uncinate process excising procedure, compared with the uncinate process preserving procedure.

Conclusion:

Preservation of the uncinate process may significantly reduce the alteration of nasal cavity airflow dynamics occurring after functional endoscopic sinus surgery for chronic rhinosinusitis.
Residual cervical lymphadenopathy after definitive treatment of nasopharyngeal carcinoma: fine needle aspiration cytology, computed tomography and histopathological findings
Authors: Toh S-T , Yuen H-W , Lim K-H , Goh Y-H , Goh H-K C
Published: September 2010

Background:

Patients with nasopharyngeal carcinoma may have residual cervical lymphadenopathy after definitive treatment of the primary tumour and regional cervical nodal disease. Whether such lymphadenopathy truly represents persistent disease is unclear. There are few published studies addressing this clinical problem.

Methods:

We retrospectively and systematically reviewed the clinical records of 12 patients with nasopharyngeal carcinoma who had presented to a tertiary academic hospital, over an 11-year period, with suspected persistent cervical nodal disease after definitive radiotherapy or concurrent chemoradiotherapy. Findings on fine needle aspiration cytology and computed tomography scanning were correlated with final histopathological results.

Results:

The incidence of negative neck dissection was 41.7 per cent. The positive and negative predictive values of fine needle aspiration cytology in identifying disease were 100 and 42.9 per cent, respectively. Computed tomography scanning had a positive predictive value of 58.3 per cent in identifying disease.

Conclusion:

In patients treated definitively for nasopharyngeal carcinoma, residual cervical lymphadenopathy may not represent persistent disease. Head and neck surgeons involved in the management of these patients should bear in mind the current limitations of fine needle aspiration cytology and computed tomography in confirming the diagnosis pre-operatively. Salvage neck dissection may over-treat some of these patients.
Weakness of buccal branch of facial nerve after canine fossa puncture
Authors: Byun J Y , Lee J Y , Baek B J
Published: September 2010

Objective:

We report a case of weakness of the buccal branch of the facial nerve after a canine fossa puncture procedure.

Method:

A case report and literature review are presented.

Results:

A 52-year-old woman diagnosed with right chronic maxillary sinusitis underwent canine fossa puncture during endoscopic sinus surgery. Immediately after the operation, she complained of motor weakness of the right upper lip and oral commissure, in the area innervated by the buccal branch of the facial nerve. Electroneurography revealed incomplete paralysis of the right buccal branch. However, facial weakness had recovered spontaneously by three months post-operatively, with no permanent disability.

Conclusion:

This is the first reported case of an injury to the buccal branch of the facial nerve following canine fossa puncture. Although the incidence of this complication is very low, surgeons should inform their patients of the possibility, and should take care when choosing the puncture site.