bluuebunny/crossref_metadata_2025 huggingface dataset:
A compact setup to study homogeneous nucleation and condensation
Authors: Karlsson Mattias , Alxneit Ivo , Rütten Frederik , Wuillemin Daniel , Tschudi Hans Rudolf
Published: March 2007

An experiment is presented to study homogeneous nucleation and the subsequent droplet growth at high temperatures and high pressures in a compact setup that does not use moving parts. Nucleation and condensation are induced in an adiabatic, stationary expansion of the vapor and an inert carrier gas through a Laval nozzle. The adiabatic expansion is driven against atmospheric pressure by pressurized inert gas its mass flow carefully controlled. This allows us to avoid large pumps or vacuum storage tanks. Because we eventually want to study the homogeneous nucleation and condensation of zinc, the use of carefully chosen materials is required that can withstand pressures of up to 106 Pa resulting from mass flow rates of up to 600 lN min−1 and temperatures up to 1200 K in the presence of highly corrosive zinc vapor. To observe the formation of droplets a laser beam propagates along the axis of the nozzle and the light scattered by the droplets is detected perpendicularly to the nozzle axis. An ICCD camera allows to record the scattered light through fused silica windows in the diverging part of the nozzle spatially resolved and to detect nucleation and condensation coherently in a single exposure. For the data analysis, a model is needed to describe the isentropic core part of the flow along the nozzle axis. The model must incorporate the laws of fluid dynamics, the nucleation and condensation process, and has to predict the size distribution of the particles created (PSD) at every position along the nozzle axis. Assuming Rayleigh scattering, the intensity of the scattered light can then be calculated from the second moment of the PSD.
Measurements of acoustic streaming in a looped-tube thermoacoustic engine with a jet pump
Authors: Biwa Tetsushi , Tashiro Yusuke , Ishigaki Masahiro , Ueda Yuki , Yazaki Taichi
Published: March 2007

This paper reports on the acoustic streaming in a looped-tube thermoacoustic prime mover equipped with an asymmetric constriction called a jet pump. The time-averaged mass flow velocity was determined using visualization methods and using acoustic field measurements. It was demonstrated that the magnitude and the direction of the velocity were dependent on the orientation of the jet pump. From the observed velocities, we estimated the heat carried away from the hot heat exchanger by the mass flow. It was shown that the heat loss was decreased from 30 W to 6.5 W by reversing the orientation of the jet pump, when the input heat power supplied to the prime mover was 100 W. The influence of the acoustic streaming was also studied from the cooling temperature of the looped-tube cooler.
Thermal-neutron scintillator: Ce3+ activated Rb2LiYBr6
Authors: Birowosuto M. D. , Dorenbos P. , de Haas J. T. M. , van Eijk C. W. E. , Krämer K. W. , Güdel H. U.
Published: March 2007

Scintillation and luminescence characteristics of Rb2LiYBr6 doped with 0.1%, 0.5%, 1%, and 5% Ce3+ are presented. Under optical and x-ray excitation, Ce3+ doublet emission is observed at 385 and 420 nm. Rb2LiYBr6:0.5% Ce3+ shows very high thermal neutron scintillation light output of 83 000 photons/neutron. An excellent neutron peak resolution of 3.6% (full width at half maximum over peak position) is observed for the 4.8 MeV neutron-reaction products energy response in Rb2LiYBr6:0.1% Ce3+. This peak shows up at 3.6 MeV γ-equivalent energy and therefore it gives an α∕β ratio of 0.74. The combination of a large fraction of neutron absorption in natural L6i (62%), a sharp neutron response peak, high light yield, and large α∕β ratio makes Rb2LiYBr6:Ce3+ an efficient scintillator for thermal neutron detection.
X-ray microdiffraction imaging of a silicon microcantilever
Authors: Hassani Kh. , Sutton M. , Tkachuk A. , Holt M.
Published: March 2007

A triple crystal x-ray topography technique with sample and analyzer mesh scans has been used to obtain micron resolution lattice orientation and strain maps of a single crystal silicon microcantilever. Both free and slightly bent states of the cantilever have been studied. The results show ∼8 mdeg twist between the cantilever and the supporting base, 0.3 m radius of anticlastic curvature, and strain on the order of −2×10−5 in the direction of surface normal.
Langmuir probe system for dusty plasmas under microgravity
Authors: Klindworth M. , Arp O. , Piel A.
Published: March 2007

This article describes a fully automated 2D-scanning Langmuir probe system for dusty plasmas under microgravity. The design combines necessary features such as random sampling, radio frequency compensation, and a compact mechanical design. The various aspects of the probe implementation and the contamination problem in the dusty plasma environment are discussed and the functionality of the system is demonstrated by measurements performed on parabolic flights.
Effect of Mo interlayer on thermal stability of polycrystalline NiSi thin films
Authors: Severino A. , La Magna A. , Anzalone R. , Bongiorno C. , Rimini E. , La Via F.
Published: March 2007

In this work we report an in situ transmission electron microscopy investigation of hole nucleation and growth under thermal processes. Two different systems are considered: a NiSi layer on poly-Si substrate without any interlayer and a NiSi+Mo (as metallic interlayer) system. This approach allows us to follow in situ hole formation and growth and to determine hole growth rate until the coalescence occurs. Furthermore, Rs measurements were performed for both systems to evaluate the effect of hole formation on electrical properties. The time and temperature dependences of the sheet resistance provide a relationship between the electrical properties and the morphological changes of the thin NiSi film during a thermal process. This dual characterization of nickel silicide with and without Mo ensures us on the key role of the interlayer in stabilizing the system when temperature is raised, causing a 60°C shift of the temperature at which degradation occurs. Moreover, the energetics of such systems have been discussed by means of a theoretical approach based on an extended Srolovitz model of the thin film instability. This analysis shows the importance of the inclusion of the polycrystalline nature of NiSi films in the theory in order to obtain a reliable classification of the experimental data.
Mn
2
+
activated red phosphorescence in BaMg2Si2O7: Mn2+, Eu2+, Dy3+ through persistent energy transfer
Authors: Ye Song , Zhang Jiahua , Zhang Xia , Lu Shaozhe , Ren Xinguang , Wang Xiao-jun
Published: March 2007

Based on persistent energy transfer, Mn2+ activated red phosphorescence is achieved in BaMg2Si2O7. Two types of Mn2+ centers with emitting peaks at 620 and 675nm, respectively, are observed and found to govern both the red luminescence and red phosphorescence spectral shapes. The spectral distribution of the red phosphorescence as a function of irradiation wavelengths and Mn2+ concentrations is systematically studied in Mn2+ and Dy3+ doubly doped and Mn2+, Eu2+, and Dy3+ tridoped samples, indicating the dominant role of persistent energy transfer on generation of the red phosphorescence. Moreover, it is found that the incorporation of Mn2+ in BaMg2Si2O7: Eu2+, Dy3+ may prolong the phosphorescent persistence time (>1h) compared with the Mn2+ free materials.
Alternans and the influence of ionic channel modifications: Cardiac three–dimensional simulations and one-dimensional numerical bifurcation analysis
Authors: Bauer S. , Röder G. , Bär M.
Published: March 2007

Cardiac propagation is investigated by simulations using a realistic three–dimensional (3D) geometry including muscle fiber orientation of the ventricles of a rabbit heart and the modified Beeler-Reuter ionic model. Electrical excitation is introduced by a periodic pacing of the lower septum. Depending on the pacing frequency, qualitatively different dynamics are observed, namely, normal heart beat, T-wave alternans, and 2:1 conduction block at small, intermediate, and large pacing frequencies, respectively. In a second step, we performed a numerical stability and bifurcation analysis of a pulse propagating in a one–dimensional (1D) ring of cardiac tissue. The precise onset of the alternans instability is obtained from computer-assisted linear stability analysis of the pulse and computation of the associated spectrum. The critical frequency at the onset of alternans and the profiles of the membrane potential agree well with the ones obtained in the 3D simulations. Next, we computed changes in the wave profiles and in the onset of alternans for the Beeler-Reuter model with modifications of the sodium, calcium, and potassium channels, respectively. For this purpose, we employ the method of numerical bifurcation and stability analysis. While blocking of calcium channels has a stabilizing effect, blocked sodium or potassium channels lead to the occurrence of alternans at lower pacing frequencies. The findings regarding channel blocking are verified within three-dimensional simulations. Altogether, we have found T-wave alternans and conduction block in 3D simulations of a realistic rabbit heart geometry. The onset of alternans has been analyzed by numerical bifurcation and stability analysis of 1D wave trains. By comparing the results of the two approaches, we find that alternans is not strongly influenced by ingredients such as 3D geometry and propagation anisotropy, but depends mostly on the frequency of pacing (frequency of subsequent action potentials). In addition, we have introduced numerical bifurcation and stability analysis as a tool into heart modeling and demonstrated its efficiency in scanning a large set of parameters in the case of models with reduced conductivity. Bifurcation analysis also provides an accurate test for analytical theories of alternans as is demonstrated for the case of the restitution hypothesis.
Electromagnetic ion acoustic perturbations in spatially varying plasma
Authors: Vranjes J. , Saleem H. , Poedts S.
Published: March 2007

It is pointed out that an ion acoustic wave in an inhomogeneous plasma naturally couples with a transverse (with respect to the direction of the wave vector) electromagnetic perturbation. Due to this coupling, the ion acoustic mode becomes essentially electromagnetic. In addition, there appears to be a lower frequency cutoff of the ion acoustic wave. The wave becomes dispersive and backward, i.e., with a negative group velocity. The presented coupling mechanism should play a role in the magnetic field generation in spatially inhomogeneous plasmas at the ion acoustic time scale.
Graphene-based resonant-tunneling structures
Authors: Pereira J. Milton , Vasilopoulos P. , Peeters F. M.
Published: March 2007

Resonant electronic transmission through graphene-based double barriers (wells) is studied as a function of the incident wave vector, the widths and heights (depths) of the barriers (wells), and the separation between them. Resonant features in the transmission result from resonant electron states in the wells or hole states in the barriers and strongly influence the ballistic conductance of the structures.
Band diagrams of spin tunneling junctions La0.6Sr0.4MnO3∕Nb:SrTiO3 and SrRuO3∕Nb:SrTiO3 determined by in situ photoemission spectroscopy
Authors: Minohara M. , Ohkubo I. , Kumigashira H. , Oshima M.
Published: March 2007

The authors report on the band diagram for epitaxial Schottky junctions of ferromagnetic metallic oxides [half-metallic ferromagnet La0.6Sr0.4MnO3 (LSMO) and itinerant ferromagnet SrRuO3 (SRO)] on Nb-doped SrTiO3 (Nb:STO) semiconductor substrates using in situ photoemission spectroscopy. The ideal Schottky barrier is formed in SRO/Nb:STO junctions with Schottky barrier height (SBH) of 1.2±0.1eV, while the measured SBH of LSMO/Nb:STO (1.2±0.1eV) is much larger than the prediction from the Schottky-Mott rule (0.7±0.1eV). These results suggest that a certain interface dipole is formed at the LSMO/Nb:STO interface.
Ferrite with extraordinary electric and dielectric properties prepared from self-combustion technique
Authors: Chen Qian , Du Piyi , Huang Wenyan , Jin Lu , Weng Wenjian , Han Gaorong
Published: March 2007

Nickel-zinc ferrites (Ni0.5Zn0.5Fe2O4) with extraordinary electric and dielectric properties were prepared by self-combustion technique. The resistivity of ferrite in the ferric citrate system is on the order of 1010Ωcm, which is about four orders higher than that of ferrite in the ferric nitrate system as well as that of ferrite prepared by the conventional method. The dielectric loss of sample in the ferric citrate system is only 0.008. The amorphous phase and its encapsulation well around the grains have played most important roles in both high resistivity and low dielectric loss of ferrite in the ferric citrate system.
Switching characteristics of microplasmas in a planar electrode gap
Authors: Rahaman Hasibur , Lee Byung-Joon , Petzenhauser Isfried , Frank Klaus , Urban Jürgen , Stark Robert
Published: March 2007

Microplasmas at high pressure have been the authors’ special interest for its practical relevance to the development of a switch. They concentrated on repetitive switching with a possibility to exceed the up to now known values for plasma closing switches and simultaneously maintaining a subnanosecond rise time of the switched pulses at a load. They examined several parameters for this purpose such as the electrode gap spacing, the electrode geometry, the gas type, the gas pressure, and including the applied voltage and current rating to operate these plasmas.
Organic thin-film transistor integration using silicon nitride gate dielectric
Authors: Li Flora M. , Nathan Arokia , Wu Yiliang , Ong Beng S.
Published: March 2007

The impact of film composition of silicon nitride (SiNx) gate dielectrics on the electrical performance of organic thin-film transistors (OTFTs) was investigated. Polythiophene OTFTs with SiNx dielectric, prepared using a series of interface modification processes, exhibited effective mobility of 0.09cm2∕Vs and on/off current ratio of 107. Overall improvement in mobility, on/off current ratio, and gate leakage current was observed as silicon content in SiNx increases. The results demonstrate the viability of using SiNx for OTFTs. The low temperature processing and large area deposition capabilities of SiNx hold great promise for integration of OTFT circuits for large area flexible electronic applications.
Excitonic ultraviolet lasing in ZnO-based light emitting devices
Authors: Ryu Y. R. , Lubguban J. A. , Lee T. S. , White H. W. , Jeong T. S. , Youn C. J. , Kim B. J.
Published: March 2007

The authors have fabricated ultraviolet (UV) laser diodes based on ZnO∕BeZnO films. The devices have p-n heterojunction structures with a multiple quantum well (MQW) active layer sandwiched between guide-confinement layers. The MQW active layer comprises undoped ZnO and BeZnO, while the two guide-confinement layers were As-doped p-type ZnO∕BeZnO and Ga-doped n-type BeZnO∕ZnO films, respectively. The exciton binding energy in the MQW region is exceptionally large (263meV). Exciton-related lasing was observed by optically pumping the MQWs. ZnO∕BeZnO-based diodes showed laser action by current injection at room temperature. The lasing mechanism is inelastic exciton-exciton collision.
Thickness-dependent energy level alignment of rubrene adsorbed on Au(111)
Authors: Wang Li , Chen Shi , Liu Lei , Qi Dongchen , Gao Xingyu , Wee Andrew T. S.
Published: March 2007

Energy level alignment of rubrene adsorbed on Au(111) was studied by photoemission spectroscopy. After rubrene adsorption, the work function is reduced from 5.24eV for clean Au to 4.31eV, suggesting the invalidity of vacuum level alignment and the presence of a strong interfacial dipole. The frontier molecular orbital energies of rubrene are modified by electrode surface polarization in the submonolayer regime. As a consequence, the hole injection barrier is thickness dependent and varies from about 0.4eV for a monolayer of rubrene to 0.9eV for a thick layer.
Bias-induced local heating in atom-sized metal contacts at 77K
Authors: Tsutsui Makusu , Kurokawa Shu , Sakai Akira
Published: March 2007

Local heating in Zn atom-sized contacts is studied at 77K under high biases. Switching rate ν of two-level fluctuations of the contact conductance is measured and statistically analyzed to estimate the contact effective temperature. Typical logν increases linearly with the bias up to 0.35V, which suggests negligible contact heating in the low-bias regime. Above 0.4V, however, logν rises steeply with the bias due to an onset of contact overheating. The estimated contact temperature rises more rapidly with the bias than the V dependence derived theoretically.
Ultrafast dynamics of water in cationic micelles
Authors: Dokter Adriaan M. , Woutersen Sander , Bakker Huib J.
Published: March 2007

The effect of confinement on the dynamical properties of liquid water is investigated for water enclosed in cationic reverse micelles. The authors performed mid-infrared ultrafast pump-probe spectroscopy on the OH-stretch vibration of isotopically diluted HDO in D2O in cetyltrimethylammonium bromide (CTAB) reverse micelles of various sizes. The authors observe that the surfactant counterions are inhomogeneously distributed throughout the reverse micelle, and that regions of extreme salinity occur near the interfacial Stern layer. The authors find that the water molecules in the core of the micelles show similar orientational dynamics as bulk water, and that water molecules in the counterion-rich interfacial region are much less mobile. An explicit comparison is made with the dynamics of water confined in anionic sodium bis(2-ethythexyl) sulfosuccinate (AOT) reverse micelles. The authors find that interfacial water in cationic CTAB reverse micelles has a higher orientational mobility than water in anionic AOT reverse micelles.
Free Trade: A Governmentality Approach
Authors: Traub-Werner Marion
Published: March 2007

The content of global free-trade rules and the number of nations beholden to them have expanded dramatically since the Uruguay round of multilateral negotiations; much of it through agreements to form preferential trade areas (PTAs). Drawing on Foucauldian governmentality studies, this paper explores how the spaces of ‘free trade’ are produced through neoliberal spatial and political imaginaries and material practices to construct ‘barriers to trade’ as objects of trade rules. These concepts are explored through a case study of rules of origin in PTAs, increasingly long technical footnotes to trade agreements that aim to sort hybrid flows of commodities and services into single nation-state categories. I argue that projects to create spaces of unimpeded trade reconfigure obstacles and barriers in new and sometimes unexpected ways.
The Fluid Scales and Scope of UK Spatial Planning
Authors: Allmendinger Philip , Haughton Graham
Published: March 2007

In this paper we argue that the emerging new systems for subnational plans and spatial strategies represent a highly contested policy terrain over which battles are being played out about what constitute the appropriate scale, scope, and process of strategic planmaking activities. Significantly, these debates are being played out in different ways in different parts of the post devolutionary UK state. The approach adopted here engages with and develops existing work on state restructuring and sociopolitical rescaling. In doing so we bring struggles over spatial planning to the centre of the analysis, addressing calls for increasing integration across different sectoral policy domains.
Politics of Scale and Networks of Association in Public Participation GIS
Authors: Ghose Rina
Published: March 2007

The public participation geographic information systems (PPGIS) research agenda has explored the issue of equitable access and use of geographic information systems (GIS) and spatial data among traditionally marginalized citizens, in order to facilitate effective citizen participation in inner-city revitalization activities. However, prior research indicates that PPGIS is a complex process, with uneven outcomes. The author contends that such unevenness can be explained by use of a new theoretical framework drawn from the literature of politics of scale and networks. The author contends that the PPGIS process occurs in ‘spaces of dependence’, containing localized social relations and place-specific conditions. The politics of securing this space leads to the creation of ‘spaces of engagement’ at multiple scales. Within these spaces, networks of association evolve to connect multiple actors from public and private sectors with community organizations. Such networks can contain structural inequities, hierarchical dominance, and fluctuating resources. But these networks also transcend political boundaries and are dynamic and flexible, enabling individuals to manipulate and modify them. In trying to control the revitalization agendas and the material resources required, the actors and community organizations construct politics of scale. For some community organizations, such scalar politics and creative alliances with critical actors allow them to navigate territorially scaled networks of power skillfully in order to gain an effective voice in decisionmaking activities. But other community organizations lag behind, and are not able to form relationships in order to secure their urban space. By the use of new empirical data, coupled with a new theoretical framework, the author aims to contribute both to greater theorization and to better understanding of the uneven and contradictory nature of PPGIS processes.
Making Labour-Market Geographies: Volatile ‘Flagship’ Inward Investment and Peripheral Regions
Authors: Dawley Stuart
Published: March 2007

In recent years a series of high-profile flagship plant closures and short-lived investment projects across peripheral regions in the United Kingdom provided a stark reminder of the potential fallibility of peripheral region development strategies based upon inward investment. Nevertheless, inward investment promotion remains a common component within the economic development strategies of UK peripheral regions. In particular, capturing the potential positive labour market contributions offered by flagship projects has been used by policymakers to legitimate the continued pursuit of inward investment. In this paper I move beyond the static analysis of employment outcomes of investment episodes by investigating the detailed structure of labour-market processes and imprints across workforce formation and dissolution. I use the example of the fluctuating and youthful history of the semiconductor fabrication industry in the old industrial region of the North East of England to illustrate the spatial, occupational, and sectoral labour-market imprints of investment episodes. Using the example of two large-scale high-technology inward-investment projects, Fujitsu and Siemens, I expand our understanding of both the labour-market dynamics associated with volatile flagship investment and the policy implications for peripheral regions.
Gene organization of the liverwort Y chromosome reveals distinct sex chromosome evolution in a haploid system
Authors: Yamato Katsuyuki T. , Ishizaki Kimitsune , Fujisawa Masaki , Okada Sachiko , Nakayama Shigeki , Fujishita Mariko , Bando Hiroki , Yodoya Kohei , Hayashi Kiwako , Bando Tomoyuki , Hasumi Akiko , Nishio Tomohisa , Sakata Ryoko , Yamamoto Masayuki , Yamaki Arata , Kajikawa Masataka , Yamano Takashi , Nishide Taku , Choi Seung-Hyuk , Shimizu-Ueda Yuu , Hanajiri Tsutomu , Sakaida Megumi , Kono Kaoru , Takenaka Mizuki , Yamaoka Shohei , Kuriyama Chiaki , Kohzu Yoshito , Nishida Hiroyuki , Brennicke Axel , Shin-i Tadasu , Kohara Yuji , Kohchi Takayuki , Fukuzawa Hideya , Ohyama Kanji
Published: March 2007

Y chromosomes are different from other chromosomes because of a lack of recombination. Until now, complete sequence information of Y chromosomes has been available only for some primates, although considerable information is available for other organisms, e.g., several species of
Drosophila
. Here, we report the gene organization of the Y chromosome in the dioecious liverwort
Marchantia polymorpha
and provide a detailed view of a Y chromosome in a haploid organism. On the 10-Mb Y chromosome, 64 genes are identified, 14 of which are detected only in the male genome and are expressed in reproductive organs but not in vegetative thalli, suggesting their participation in male reproductive functions. Another 40 genes on the Y chromosome are expressed in thalli and male sexual organs. At least six of these genes have diverged X-linked counterparts that are in turn expressed in thalli and sexual organs in female plants, suggesting that these X- and Y-linked genes have essential cellular functions. These findings indicate that the Y and X chromosomes share the same ancestral autosome and support the prediction that in a haploid organism essential genes on sex chromosomes are more likely to persist than in a diploid organism.
Arias‐Stella reaction in an adenomyomatous polyp of the uterus
Authors: SATO HIROKAZU , NANJO HIROSHI , TANAKA HIDENORI , TANAKA TOSHINOBU
Published: March 2007

We describe a rare case of an Arias‐Stella reaction in an adenomyomatous polyp of the endometrium found in the first trimester of pregnancy. A 33‐year‐old Japanese woman, gravida 1, para 1, presented for an initial prenatal examination at 6‐week gestation; ultrasound revealed a myoma‐like solid mass in the cervical canal. An abnormal Papanicolaou's smear (highly suspicious of adenocarcinoma) prompted the resection of this pedunculated polyp. Histologically, the musculature located in the center of the polyp was covered by the endometrium; numerous glands within both the endometrium and the musculature exhibited an Arias‐Stella reaction. This explains the result of Papanicolaou's smear, because subsequent smears — both intrapartum and postpartum — were negative. To our knowledge, this is the first reported incident of an Arias‐Stella reaction in an adenomyomatous polyp. This could be one of the diagnostic pitfalls in Papanicolaou's smears taken during pregnancy.
Maternal mid‐arm circumference and other anthropometric measures of adiposity in relation to infant birth size among Zimbabwean women
Authors: OGBONNA CHINYERE , WOELK GODFREY B. , NING YI , MUDZAMIRI SARAH , MAHOMED KASSAM , WILLIAMS MICHELLE A.
Published: March 2007

Background.To examine relationships between maternal anthropometric measures in Zimbabwean women and indices of infant birth size.Methods.We conducted a cross‐sectional study of pregnant women admitted for labor and delivery at the Harare Maternity Hospital from July 1998 to March 1999. The study population was comprised of 498 participants who delivered singleton infants. Anthropometric measures (height, weight, and mid‐arm circumference) were taken during participants’ postpartum hospital stay. Logistic regression and least‐squares regression procedures were used to assess the association of maternal measures with infant size.Results.Women in the highest weight quartile (>67 kg) were 58% less likely to have a low‐birth‐weight infant when compared to women in the lowest quartile (<57 kg) (OR = 0.42, 95% CI 0.19–0.90). Women in the highest body mass index quartile were 75% less likely to have a low‐birth‐weight infant compared to women in the lowest quartile (>27 versus <23 kg/m2: OR = 0.25, 95%CI 0.10–0.60). Similar trends were seen for risk of low birth weight in relation to mid‐arm circumference. Maternal mid‐arm circumference was most strongly related with the four infant size indices measured. Each unit increase in maternal mid‐arm circumference resulted in a 36.1‐g increase in infant birth weight (p<0.001). In general, women who were heavier at the time of delivery were less likely to have a low‐birth‐weight infant than women who were lighter.Conclusions.In areas where food security is a public health concern, as it is in most parts of the developing world, pregnant women may not be meeting their own nutritional needs and those of their fetus.
Pregnancy outcome and recurrence after conservative laparoscopic surgery for borderline ovarian tumors
Authors: TINELLI F.G. , TINELLI RAFFAELE , LA GROTTA F. , TINELLI A. , CICINELLI E. , SCHÖNAUER M.M.
Published: March 2007

Background. The aim of this study was to evaluate the safety and efficacy of conservative laparoscopic management of borderline ovarian tumors, and to assess pregnancy outcome and recurrence after fertility‐sparing surgery. Methods. From 1995 to 2005, 43 patients of reproductive age presented with adnexal mass, which was subsequently diagnosed as a borderline tumor of the ovary. These patients were treated by conservative laparoscopic surgery, with intraoperative staging of the disease. Patients were evaluated every 3 months for the first 2 years, and then every 6 months thereafter, to determine the best modality for following patients after conservative surgery. Results. Three (7%) patients developed a recurrence after conservative treatment. Among the 43 patients who had conservative surgery, 21 (49%) became pregnant during the follow‐up period; 12 (57%) conceived spontaneously, and the remaining 9 (43%) patients underwent caesarean section. Conclusions. In our opinion, conservative laparoscopic treatment of borderline ovarian tumors is an appropriate and reasonable therapeutic option for young women with low‐stage disease who wish to preserve their childbearing potential, because the fertility results are encouraging. Recurrence can be noted after this type of treatment, but the cases of recurrent disease can be detected with close follow‐up and treated accordingly. Careful selection of candidates for this kind of treatment is, of course, necessary, and close follow‐up is required.
Perceptions and attitudes of pregnant women towards caesarean section in urban Nigeria
Authors: AZIKEN MICHAEL , OMO‐AGHOJA LAWRENCE , OKONOFUA FRIDAY
Published: March 2007

Objectives. To determine the perceptions and attitudes towards caesarean section [CS] among women attending maternity care at the University of Benin Teaching Hospital in Nigeria. Methods. Some 413 consecutive women, attending antenatal care in the hospital, were interviewed with a structured questionnaire that solicited information on their socio‐demographic characteristics, their previous pregnancy and delivery history, and their knowledge and attitudes towards CS. Additional focus group discussions and in‐depth interviews were held with women who recently underwent CS in the hospital, to gain further insights into attitudes and perception about CS in the women. Results. The women had good knowledge of CS; however, only 6.1% were willing to accept CS as a method of delivery, while 81% would accept CS if needed to save their lives and that of their babies. Up to 12.1% of women would not accept CS under any circumstances. Logistic regression showed that women's low level of education, and past successful vaginal and instrumental deliveries, were most likely to be associated with women's non‐acceptance of indicated caesarean section. Further analysis showed that this was mainly due to inaccurate cultural perceptions of labour and caesarean section in the cohort of women. Conclusion. There is a need for programs to increase women's and community understanding and perceptions of CS as a method of delivery in Nigeria.
Primary hyperparathyroidism is common in postmenopausal women with forearm fracture and low bone mineral density
Authors: BERGSTRÖM INGRID , LANDGREN BRITT‐MARIE , FREYSCHUSS BO
Published: March 2007

Objective. The most common etiologies of osteoporosis in women are estrogen deficiency and, later on in life, the functional changes caused by aging. There are, however, numerous causes of secondary bone loss. Little is known about the prevalence of concomitant disease in women with distal forearm fracture, which is the most common of the classical osteoporotic fractures. Method. Postmenopausal healthy women between 45 and 65 years of age with a forearm fracture were invited to join a prospective randomized study evaluating the effect of physical training on bone mineral density. The main inclusion criteria were previous forearm fracture and BMD T‐score in the interval −1 to −3.0. Of the 167 postmenopausal women with a forearm fracture, 23% had a normal BMD, 59% had osteopenia, and 18% had osteoporosis. Results. Of the 119 patients meeting the BMD criteria for inclusion, one patient was found to have sprue, two were diagnosed with thyreotoxicos, and eight had primary hyperparathyroidism. The prevalence of primary hyperparathyroidism in this population was 6.7%, and thus three times higher than that previously observed in healthy Swedish postmenopausal women. Conclusion. The data suggest an increased prevalence of primary hyperparathyroidism in women with forearm fracture and low bone mass, and imply the importance of basic laboratory screening in this population.
Severe life events and impaired fetal growth: a nation‐wide study with complete follow‐up
Authors: HANSEN PRECHT DORTHE , KRAGH ANDERSEN PER , OLSEN JØRN
Published: March 2007

Background. To estimate the association between severe maternal life events and infants small for gestational age at different gestational ages at birth. Methods. From 1980 to 1992 all women exposed to severe life events such as death or first hospitalization for cancer or acute myocardial infarction in partners or children during pregnancy or up to 485 days before were identified through national registers. We included all 3,402 exposed pregnancies and 19,551 unexposed pregnancies randomly selected to the control cohort and performed adjusted stratified Cox proportional hazards regression analyses with time‐dependent covariates. Results. These life events were not associated with SGA in general, but exposed infants born before 32 weeks of gestation had twice the risk for being born with a birth weight ≤10% for the gestational age, (adjusted hazard rate ratio 1.99, 95% confidence interval (CI) (1.26; 3.17)). Infants, whose mother had lost a child had the highest risk (adjusted hazard rate ratio 2.73, 95% CI (1.67; 4.48)). Infants whose mother had been exposed to severe life events during the year before pregnancy but not during the pregnancy had increased risks of being born as small for gestational age preterms. Conclusion. Severe life events are not in general associated with being SGA, but may be associated with SGA in preterms born before 32 weeks of gestation. Our study indicates that stress‐induced SGA may have its origin in the earliest weeks of gestation and only affects the more preterm infants.
Prognostic markers of high‐grade squamous intraepithelial lesions: the role of p16INK4a and high‐risk human papillomavirus
Authors: ELEUTÉRIO JOSÉ , GIRALDO PAULO CÉSAR , GONÇALVES ANA KATHERINE , CAVALCANTE DIANE ISABELLE MAGNO , DE ALMEIDA FERREIRA FRANCISCO VALDECI , MESQUITA SUZANA MOREIRA , MORAIS SIRLEI SIANI
Published: March 2007

Background. p16INK4a seems to be an indicator of the grade of Human Papillomavirus‐induced lesions and a possible predictor of the lesion evolution. There are few studies about the role of HPV test and p16INK4a in diagnosis of high‐grade cervical lesions in South‐American women. The aim of the present study was to evaluate the presence of p16INK4a and high‐risk HPV‐DNA expression in cases diagnosed as squamous intra‐epithelial lesion and evaluate their role in the approach of high‐grade squamous intra‐epithelial lesion. Methods. p16INK4a and high‐risk Human papillomavirus were investigated in 96 samples of the cervix (13 cases of high grade squamous intraepithelial lesions, 26 cases of low grade intraepithelial lesions and 57 normal tissues). The p16INK4a was identified by immunohistochemistry using the p16INK4a kit (E6H4 clone, DakoCytomation, Carpinteria, CA) and Human papillomavirus DNA was classified by hybrid capture (Digene®). Associations were evaluated by the KAPPA index. Results. The p16INK4a was detected in 92.3% of the high‐grade squamous intraepithelial lesions, in 15.4% of the low‐grade and in none of the normal tissues. The sensitivity, specificity, positive predictive value and negative predictive value for high‐grade lesion were 92.3%, 100%, 100%, and 98.3%, respectively when considering p16INK4a expression, and 100%, 70.2%, 43.3% and 100%, respectively when considering high‐risk HPV. Conclusions. p16INK4a test was better associated with high‐grade intraepithelial lesion (κ = 0.95) than was the presence of high‐risk HPV (κ = 0.47). Both tests could be complementary to high‐grade squamous intra‐epithelial lesion screening and help to define the diagnosis of the inconclusive low‐grade/high‐grade squamous intraepithelial lesion cases.
Early random capillary glucose level screening and multidisciplinary antenatal teamwork to improve outcome in gestational diabetes mellitus
Authors: BERG MARIE , ADLERBERTH ANNIKA , SULTAN BO , WENNERGREN MARGARETA , WALLIN GUNNAR
Published: March 2007

Background. This study describes maternal and neonatal characteristics and delivery outcome in women with gestational diabetes mellitus [GDM], compared to a control group. Methods. A retrospective observational study of 719 women with GDM was undertaken in a Swedish urban district. All other parturients at the same hospital served as the control group. GDM was diagnosed using random capillary glucose levels at fixed intervals, beginning early in pregnancy. An oral glucose tolerance test was performed at glucose levels ≥7.0 mmol/l (127.8 mg/dl). Data was analysed according to glucose levels at diagnosis, ie, mild or severe GDM. Results. GDM was diagnosed in 2.28% of the women who were older and had higher Body Mass Index [BMI]. A high proportion was of non‐Nordic origin (44.5%); they had severe GDM more often (49.1%) than the Nordic group (33.1%). The GDM‐mild group had less complications and abnormalities, compared to the GDM‐severe group, although both groups differed from the control group in this respect. Delivery was spontaneous in 70.2% of GDM‐mild, 65.7% of GDM‐severe and 81.0% of the control group. LGA (+2 SD) was found in 4.8, 10.5 and 3.2%, respectively. Conclusion. Early non‐fasting random universal screening and multidisciplinary antenatal teamwork intervention seems to be favourable, with low rates of excessive fetal growth, instrumental vaginal delivery and caesarean section.
Attitudes among sperm donors in 1992 and 2002: a Danish questionnaire survey
Authors: ERNST ERIK , JAKOB INGERSLEV HANS , SCHOU OLE , STOLTENBERG MEREDIN
Published: March 2007

Background. Sweden prohibited anonymous sperm donation in 1985 and Norway in 2005. In recent years the question of continued use of sperm from anonymous sperm donors for insemination in couples and the question of insemination of single and lesbian women have been vividly debated in Denmark. This survey examines the sperm donors’ attitude towards these questions and describes any changes in attitude between 1992 and 2002. The objective is to investigate the likely consequences of abolishing anonymous sperm donation in Denmark. Methods. A questionnaire survey carried out among donors at a private Danish sperm bank, Cryos‐International Sperm Bank Ltd. Over a period of 9 weeks in 2002 an anonymous questionnaire was handed out to all donors who were in contact with the sperm bank. The results were compared to a questionnaire survey carried out in 1992 at the same sperm bank. Results. In 2002, 25% (19% approved; 35% non‐approved) of the donors stated that they would continue as donors if anonymity was abolished, whereas in 1992 the number was 32%. But when donors were asked whether they would accept that the children could contact them, only 22% agreed in 1992 and 13% (15% approved; 10% non‐approved) in 2002. Altruistic as well as financial motives were the main factors for becoming a donor in both 1992 and 2002. Approximately 50% would accept sperm donation to lesbians in both surveys. In 2002 approximately one third was positive towards donation to single women. Conclusion. Maintaining anonymity is still important for the vast majority of the donors.
Outpatient cervical ripening before first‐trimester surgical abortion: a comparison between misoprostol and isosorbide mononitrate
Authors: RADULOVIC NINA , NORSTRÖM ANDERS , EKERHOVD ERLING
Published: March 2007

Background. Vaginal administration of prostaglandin analogues as well as nitric oxide donors before first‐trimester surgical abortion has been shown to induce effective cervical ripening. In addition, nitric oxide donors, such as isosorbide mononitrate and nitroglycerin, have been associated with a patient‐friendly side‐effect profile when administered 3 h before the surgical procedure. We wanted to compare the cervical ripening effect and possible side effects of isosorbide mononitrate and the prostaglandin analogue misoprostol when self‐administered at bedtime the evening before surgical abortion. Methods. One hundred and twenty nulliparous women scheduled for suction termination of pregnancy in the first trimester were randomly assigned to receive per vaginam either 40 mg of isosorbide mononitrate or 200 µg of misoprostol. Sixty of the women were included for assessment of cervical ripening as well as evaluation of side effects. The other 60 women were recruited for assessment of side effects only. Cervical ripening was evaluated by measuring baseline cervical dilation and the cumulative force to dilate the cervix to 9 mm by means of a cervical tonometer. For assessment of side effects, the women were asked to complete a symptom questionnaire. Results. Cervical resistance was significantly higher in women treated with isosorbide mononitrate compared to misoprostol (median cumulative force 73 versus 15 N). Common side effects of misoprostol were abdominal pain (69%), nausea (44%), and vaginal bleeding (66%), while in the isosorbide mononitrate group headache was frequently experienced (79%). In both treatment groups, the frequency and intensity of side effects gradually increased during the treatment interval. Conclusions. Misoprostol induced a more pronounced cervical ripening than isosorbide mononitrate, but both regimens were associated with a high frequency of side effects.
Analysis of malpractice claims with a focus on oxytocin use in labour
Authors: JONSSON MARIA , LINDEBERG NORDÉN SOLVEIG , HANSON ULF
Published: March 2007

Background. The objective of this study was to analyse the motives behind disciplinary action in obstetric malpractice cases concerning delivery, and to evaluate the frequency of inappropriate oxytocin use in these cases. Methods. An analysis of all malpractice claims resulting in disciplinary action against physicians and midwives during the period 1996–2003. Investigations and decisions made by the Board of Medical Responsibility were reviewed with special focus on the use of oxytocin. Results. Of 77 cases, 60 regarded patients in labour. In the majority, there had been a normal pregnancy and spontaneous start of labour (78%). At the beginning of labour, 87% showed a normal fetal heart rate (FHR) pattern, indicating fetal well‐being. In 70%, there was adverse fetal outcome with brain damage or death. The most common reason for disciplinary action was improper interpretation of fetal monitor tracings and corresponding failure to recognise fetal distress (76%). Injudicious use of oxytocin was common (68.5%), and was the primary reason for disciplinary action in 33% of the cases. Conclusion. In a Swedish setting, a few common clinical problems pervade; interpretation of FHR patterns and the use of oxytocin account for the majority of rulings of negligence in malpractice cases regarding delivery. Analysis of the cases suggests that the adverse fetal outcomes could possibly have been prevented.
Empirical Investigation of Two Assumptions in the Diagnosis of DSM-IV Major Depressive Episode
Authors: Sakashita Chika , Slade Tim , Andrews Gavin
Published: March 2007

Objective: The aim of the current study was to examine two major assumptions behind the DSM-IV diagnosis of major depressive episode (MDE): that depression represents a distinct category defined by a valid symptom threshold, and that each depressive symptom contributes equally to the diagnosis.

Methods: Data were from the Australian National Survey of Mental Health and Wellbeing. Participants consisted of a random population-based sample of 10 641 community volunteers, representing a response rate of 78%. DSM-IV diagnoses of MDE and other mental disorders were obtained using the Composite International Diagnostic Interview, version 2.0. Analyses were carried out on the subsample of respondents who endorsed either depressed mood or loss of interest (n =2137). Multivariate linear regression analyses examined the relationship between the number and type of symptoms and four independent measures of impairment.

Results: The relationship between the number of depressive symptoms and the four measures of impairment was purely linear. Three individual symptoms (sleep problems, energy loss, and psychomotor disturbance) were all independent predictors of three of the four measures of impairment.

Conclusions: Counting symptoms alone is limited in guiding a clear diagnostic threshold. The differential impact of individual symptoms on impairment suggests that impairment levels may be more accurately estimated by weighting the particular symptoms endorsed.
Self-reported Suicide Attempts and Associated Risk and Protective Factors Among Secondary School Students in New Zealand
Authors: Fleming Theresa M. , Merry Sally N. , Robinson Elizabeth M. , Denny Simon J. , Watson Peter D.
Published: March 2007

Objective: To examine associations between individual, family, school and community characteristics and rates of suicide attempts in a national population sample of New Zealand secondary school students.

Method: A total of 9570 randomly selected 9- to 13-year-old students from 114 schools were surveyed, using the New Zealand Adolescent Health Survey. This is a 523-item anonymous self-report comprehensive questionnaire delivered by Multi-Media Computer-Assisted Self-Interviewing. Multivariate analyses were used to examine correlates of self-reported suicide attempts within the last 12 months.

Results: In total, 739 participants (4.7% of males and 10.5% of females) reported having made a suicide attempt within the last 12 months. Depressive symptoms, alcohol abuse, -having a friend or family member attempt suicide, family violence and non-heterosexual attractions were independently associated with increased rates of suicide attempts while parents caring, other family members caring, teachers being fair and feeling safe at school were independently associated with decreased rates of suicide attempts. Caring friendships, attending worship frequently, possible sexual abuse and anxiety symptoms were not independently associated with suicide attempts. Risk and protective factors operated in the same way for male and female students and for those with and without other suicide predictors.

Conclusions: New Zealand secondary school students, particularly female students, report high rates of suicide attempts. Risk of suicide attempts is lower in students reporting caring home and fair, safe school environments and this effect remains once depression is taken into account. This study confirms the importance of depression, substance use, problem behaviour, negative life events, exposure to suicide behaviour by others and the significance of sexual orientation in suicidal behaviour among school students and provides evidence of the importance of the family and school environments in reducing risk among this group.