bluuebunny/crossref_metadata_2025 huggingface dataset:
A robotic assistant for stereotactic neurosurgery on small animals
Authors: Ramrath L. , Hofmann U. G. , Schweikard A.
Published: October 2008

Background

This work presents the development and performance analysis of a robotic system for stereotactic neurosurgery on small animals. The system is dedicated to the precise placement of probes in the small animal brain, thus providing an improved framework for brain research.

Methods

Based on an analysis of small animal stereotaxy, the mechanical design of the robotic system is presented. Details of the structure and mechanical components and a kinematic description are outlined. The calibration process of the system for arbitrary probes is described. To analyse the mechanical positioning accuracy of the system, a testbed is presented.

Results

Positioning performance results show that the system features a mean mechanical positioning accuracy of 32 µm and a mean positioning repeatability of 11 µm.

Conclusion

The system meets the requirements of targeting small functional areas within the brain of small animals and thus offers a new tool for small animal brain research. Copyright © 2008 John Wiley & Sons, Ltd.
An active endoscopic robot based on wireless power transmission and electromagnetic localization
Authors: Li Hongwei , Yan Guozheng , Ma Guanying
Published: October 2008

Background

Conventional endoscopes have the disadvantages of causing pain to patients because of their large dimensions and allowing incomplete inspection because of their limited power.

Methods

An active inchworm‐like endoscopic robot has been designed, which is based on electromagnetic localization and synthesis of magnetic field strength vectors.

Results

The efficiency of wireless power transmission can be kept above 0.9% when the power‐receiving coil is at arbitrary position and orientation. The position error of localization is < 10 mm and the average error of orientation angle is 2° . When the robot moves through part of the porcine colon, images are transmitted outwards continuously at a speed of 30 fps and the temperature rise of the colon is < 1 °C. By simulation, the electromagnetic exposures to the human body are lower than international standards.

Conclusions

The endoscopic robot is a promising tool for use by doctors, although further experiments and improvements need to be done. Copyright © 2008 John Wiley & Sons, Ltd.
The MARVIN message authentication code and the LETTERSOUP authenticated encryption scheme
Authors: Simplicio Marcos A. , Barbuda Pedro d'Aquino F. F. S. , Barreto Paulo S. L. M. , Carvalho Tereza C. M. B. , Margi Cintia B.
Published: October 2008

We present MARVIN, a new parallelizable message authentication code (MAC) based on the ALRED family. The new algorithm is designed with resource‐constrained platforms inmind and explores the structure of an underlying block cipher toprovide security at a small cost in terms of memory needs. Also,we show how MARVIN can be used as an authentication‐onlyfunction or else in an authenticated encryption with associateddata (AEAD) scheme. We define a new AEAD proposal called LETTERSOUP, which is based on the mode ofoperation. Finally, we LFSRC analyze the security and performance of theresulting schemes. Copyright © 2008 John Wiley & Sons, Ltd.
Information depth determination for hard X‐ray photoelectron spectroscopy up to 15 keV photoelectron kinetic energy
Authors: Rubio‐Zuazo J. , Castro G. R.
Published: October 2008

In the present work, we have determined the information depth in a solid for hard X‐ray photoelectron spectroscopy (HAXPES) up to a photoelectron kinetic energy of 15 keV. For that, we have followed the evolution of the photoemission signal from different core levels of a gold overlayer grown in situ on a polycrystalline copper substrate as a function of the photoelectron kinetic energy. We demonstrate that in the case of gold, an information depth of 57 nm can be achieved by detecting photoelectrons with 15‐keV kinetic energy. The photoemission signal produced at this depth corresponds to 0.2% of the signal coming from a semi‐infinite solid bulk. Such a high sensitivity can only be reached with the combination of a third‐generation synchrotron radiation beam with a high‐transmission electron analyzer. Copyright © 2008 John Wiley & Sons, Ltd.
Characteristics of bioactive glass coatings obtained by pulsed laser deposition
Authors: Zhao Yafan , Song Mingda , Liu Jian
Published: October 2008

A type of bioglass (named Mg10) formed by the substitution of 10wt%Na2O with MgO in Bioglass® 45S5 was designed and coated on the substrate Ti6Al4V by pulsed laser deposition (PLD) technique. Scratch test results show that the bonding strength of Mg10 coating with the substrate is higher than that of 45S5 coating. The reason is that the thermal expansion coefficient of Mg10 matches that of Ti6Al4V more than that of 45S5. The in vitro behavior of the Mg10 bioglass coatings is similar to that of 45S5 bioglass coatings and follows the bioactive mechanism. The bioactivity level of Mg10 coating is lower than that of 45S5 coating. This could be attributed to the addition of Mg in Mg10, as part of Mg ions in the bioglass become network former, which decreases the Si‐O‐NBO/Si‐O‐Si (s) intensity ratio of the Mg10 coating. Therefore, substitution of 10wt%Na2O with MgO on the base of Bioglass® 45S5 coatings can improve their long‐term stability while maintaining a good biological response. Copyright © 2008 John Wiley & Sons, Ltd.
Micellar electrokinetic chromatography for high‐performance analytical separation
Authors: Terabe Shigeru
Published: October 2008

Capillary electrophoresis (CE) is a relatively new method of analytical separation having the advantages of high separation efficiency, requirement of a small sample amount, low operating cost, and fast separation time. CE is a separation method where the analyte migrates under an electric field due to a charge on the analyte. Hence, CE was unable to separate neutral analytes until the advent of micellar electrokinetic chromatography (MEKC). MEKC is performed with an addition of ionic micelles to an electrophoretic medium, where a portion of the analyte is incorporated into the micelle and has an apparent charge, which can be subject to electrophoretic separation. The migration velocity of the neutral analyte in MEKC depends on what portion of the analyte is incorporated into the micelle. Thus, the separation principle of MEKC is similar to that of chromatography, although the micelle corresponding to the stationary phase in chromatography is not stationary inside the capillary. The fundamental characteristics and theoretical treatments of the behavior of the analyte in MEKC were studied extensively by the author's group. MEKC has been established as one of the most popular separation modes in CE. This review describes how MEKC was developed and how it is useful as a method of analytical separation. © 2008 The Japan Chemical Journal Forum and Wiley Periodicals, Inc. Chem Rec 8: 291–301; 2008: Published online in Wiley InterScience (www.interscience.wiley.com) DOI 10.1002/tcr.20156
Saccharomyces cerevisiae oxidosqualene‐lanosterol cyclase: A chemistry–biology interdisciplinary study of the protein's structure–function–reaction mechanism relationships
Authors: Wu Tung‐Kung , Chang Cheng‐Hsiang , Liu Yuan‐Ting , Wang Tsai‐Ting
Published: October 2008

The oxidosqualene cyclases (EC 5.4.99‐) constitute a family of enzymes that catalyze diverse cyclization/rearrangement reactions of (3S)‐2,3‐oxidosqualene into a distinct array of sterols and triterpenes. The relationship between the cyclization mechanism and the enzymatic structure is extremely complex and compelling. This review covers the historical achievements of biomimetic studies and current progress in structural biology, molecular genetics, and bioinformatics studies to elucidate the mechanistic and structure–function relationships of the Saccharomyces cerevisiae oxidosqualene‐lanosterol cyclase‐catalyzed cyclization/rearrangement reaction. © 2008 The Japan Chemical Journal Forum and Wiley Periodicals, Inc. Chem Rec 8: 302–325; 2008: Published online in Wiley InterScience (www.interscience.wiley.com) DOI 10.1002/tcr.20157
Catalytic synthesis of oligoene and enyne derivatives through carbometalation of internal alkynes
Authors: Satoh Tetsuya , Tsurugi Hayato , Miura Masahiro
Published: October 2008

A number of new synthetic methods for π‐conjugated oligoene and enyne compounds are described. Thus, diene and higher oligoene derivatives are selectively constructed by palladium‐catalyzed arylation reactions of internal alkynes in the presence of arylboronic acids or alkenes as terminators. In contrast, the synthesis of various enyne derivatives is achieved effectively by homo‐ or cross dimerization of alkynes under rhodium catalysis. © 2008 The Japan Chemical Journal Forum and Wiley Periodicals, Inc. Chem Rec 8: 326–336; 2008: Published online in Wiley InterScience (www.interscience.wiley.com) DOI 10.1002/tcr.20158
Design and negative refraction investigation of a compact left‐handed metamaterial
Authors: Meng Fan‐Yi , Wu Qun , Yang Guo‐Hui , Fu Jia‐Hui
Published: October 2008

A compact left‐handed metamaterial (LHM) with miniaturized unit cell and broad bandwidth is proposed. By optimization of design, the relative bandwidth is up by 21.1%, and the unit cell electrical length is only 0.072 at the central frequency where the LHM is available. The negative refraction characteristics of the wedge‐shaped LHM are investigated using full‐wave simulation, and it is shown that the designed LHM exhibits negative refraction in a broad band range of 8.5–10.5 GHz, and hence the existence of the LHM is proven. Copyright © 2008 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.
Neural network approach to stereoscopic correspondence of three‐dimensional particle tracking velocimetry
Authors: Sapkota Achyut , Ohmi Kazuo
Published: October 2008

Particle tracking velocimetry (PTV) is a reliable measurement technique for the quantitative study of fluid flows by observing the motion of the particles seeded in them and is widely used in several industrial applications. The nature of the flow can be precisely observed only if all the three components of the velocity are computed. In 3‐D PTV system, particles viewed by two (or more than two) stereoscopic cameras with a parallax have to be correctly paired at every synchronized time step. This is important because the 3‐D coordinates of individual particles cannot be computed without the knowledge of the correct stereo correspondence of the particles. In the present work, a neural network–based algorithm has been proposed for the stereoscopic particle pairing process. The correspondence between the particle pairs is modeled as a constrained optimization problem. The constraints are provided on the basis of the epipolar geometry of the particle images and on the basis of the uniqueness of the matched pairs. The results are tested with various standard images. Copyright © 2008 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.
Particle swarm optimization: a numerical stability analysis and parameter adjustment based on swarm activity
Authors: Yasuda Keiichiro , Iwasaki Nobuhiro , Ueno Genki , Aiyoshi Eitaro
Published: October 2008

In this paper, swarm activity is defined as the root mean square velocity of the particles in particle swarm optimization (PSO). Using numerical experiments, an investigation of the relationship between swarm activity and intensification/diversification during a PSO search, as well as the similarity between swarm activity and temperature in simulated annealing (SA), was conducted. Furthermore, a new method for determining the numerical stability of PSO based on swarm activity was developed. The stability limit for PSO based on the new numerical stability analysis method was compared with the stability limit based on a conventional analytical stability analysis method. Also, using the results of a numerical stability analysis of PSO, the search of conventional PSO methods was examined. From this analysis, issues related to diversification (global search) and intensification (local search) during the search could be explored. Finally, after showing that swarm activity can be controlled using the stable and unstable regions in PSO, a new PSO method that uses swarm activity feedback to control diversification and intensification during a search was proposed. The versatility and search capabilities of the new PSO were examined based on the results of numerical experiments using five typical benchmark problems. Copyright © 2008 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.
Optical and electrical properties of tunnel junctions with Au nanoparticles utilizing localized surface plasmon resonance
Authors: Uchida Hironaga , Fumoto Hiroshi , Baryshev Alexander , Kim Jooyoung , Inoue Mitsuteru
Published: October 2008

We fabricated a planer type tunnel structure with Au nanoparticles that were formed between two electrodes on a substrate. The mean diameter of the Au nanoparticles was 7.3 nm, and the wavelength of the localized surface plasmon resonance was about 544 nm. Tunnel current flowing through Au nanoparticles between two electrodes changed by illumination of a laser beam. A large change of tunnel current was observed when a plane of linear polarized light (electric field) corresponded to the direction of electron tunneling through Au nanoparticles; the change of tunnel current obtained by laser illumination with a wavelength of 532 nm was larger than the one with a wavelength of 633 nm. The dependencies on wavelength and polarization of laser beam suggest that the change of tunnel current occurs not only by the thermal effect but also by the localized surface plasmon resonant effect. Copyright © 2008 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.
Fabrication of carbon nanotubes and byproducts by arc discharge in DC motors
Authors: Aoyagi Minoru
Published: October 2008

The electrical arc generated between the brush and commutator of a DC motor is similar to the arc discharged between carbon electrodes. Since carbon nanotubes are produced by carbon electrode arc discharge, it is possible to produce carbon nanotubes and byproducts via the electrical arc generated between the brush and commutator of a DC motor. In this paper, we demonstrate experimentally that single‐wall carbon nanotubes and byproducts were generated on the surface of the brushes by the electrical arc of DC motors. The yield of the nanotubes was very low, and the nanotubes were of poor structural quality. If carbon nanotubes with a high electrical conductivity are produced across the segmented copper bars of the commutator, they can potentially cause the DC motor to flashover. Our experimental findings reveal that these carbon nanotubes and byproducts have no effect on the flashover of DC motors because they are extremely small and occur in small quantities. Copyright © 2008 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.
Two‐dimensional numerical simulation of commercial scale nonequilibrium MHD power generator coupled with radio‐frequency electromagnetic field
Authors: Fujino Takayasu , Kominami Susumu , Ishikawa Motoo , Okuno Yoshihiro
Published: October 2008

R–z two‐dimensional numerical simulations have been carried out to explore the possibility and usefulness of a support technique of the plasma production using an external radio‐frequency (rf) electromagnetic field for a commercial‐scale, large nonequilibrium disk‐shaped MHD generator with a thermal input of 1000 MW. Numerical results have demonstrated that the rf application is useful for improving the plasma state and the generator performance even for the commercial‐scale MHD generator having the large plasma volume between rf coils. For low seed fraction (SF) condition, the additional rf Joule heating enhances the ionization of seed material in the upstream region of the MHD channel. As a result, the generator performance can be improved. On the other hand, applying the rf electromagnetic field has little effect on the plasma state and the generator performance under a relatively high SF condition, where large self‐excited Joule heating is obtained. Furthermore, applying the rf electromagnetic field enables to obtain the same level of enthalpy extraction ratio (EE) with higher electrical efficiency for low SF condition. Consequently, the maximum value of the isentropic efficiency (IE) of the MHD generator can be substantially improved by applying the rf electromagnetic field. Copyright © 2008 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.
A traffic‐flow‐adaptive controller of double‐deck elevator systems using genetic network programming
Authors: Zhou Jin , Yu Lu , Mabu Shingo , Shimada Kaoru , Hirasawa Kotaro , Markon Sandor
Published: October 2008

The double‐deck elevator system (DDES) has been invented firstly as a solution to improve the transportation capacity of elevator group systems in the up‐peak traffic pattern. The transportation capacity could be even doubled when DDES runs in a pure up‐peak traffic pattern where two connected cages stop at every two floors in an elevator round trip. However, the specific features of DDES make the elevator system intractable when it runs in some other traffic patterns. Moreover, since almost all the traffic flows vary continuously during a day, an optimized controller of DDES is required to adapt to the varying traffic flow. In this paper, we have proposed a controller adaptive to traffic flows for DDES using Genetic Network Programming (GNP) based on our past studies in this field, where the effectiveness of DDES controller using GNP has been verified in three typical traffic patterns. A new traffic flow judgment part was introduced into the GNP framework of DDES controller in this paper, and the different parts of GNP were expected to be functionally localized by the evolutionary process to make the appropriate cage assignment in different traffic flow patterns. Simulation results show that the proposed method outperforms a conventional approach and two heuristic approaches in a varying traffic flow during the working time of a typical office building. Copyright © 2008 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.
High efficiency DC–DC converter for wide‐ranging loads with gradual reverse current stopping technique
Authors: Yamada Kouhei , Sugahara Satoshi , Fujii Nobuo
Published: October 2008

A novel reverse current stopping technique for synchronous rectifiers in DC–DC converters is proposed. It is based on gradual adjustment of the ON‐time of the synchronous rectifier to finally stop the reverse current. Therefore, delay to detect and stop reverse current does not cause extra reverse current, so almost perfect reverse current stopping can be achieved with small DC power consumption. An example circuit of the proposed technique was designed and included in a fixed ON‐time pulse frequency modulation (PFM) control DC–DC converter. The designed converter was fabricated in the 0.35 µm CMOS process, and then its operation was verified. Copyright © 2008 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.
An estimator to characterize varying time delays based on cross‐correlation function for the tuning of IP network‐based small DC motor speed control
Authors: Matsuo Kenshi , Miura Takeshi , Taniguchi Toshiyuki
Published: October 2008

Internet protocol (IP) network‐based control systems have recently attracted interest. There is, however, the problem such that varying time delays and packet losses in the networks induce performance degradation. Therefore, it is important how the traffic conditions are characterized. Conventional methods have characterized varying time delays based on round trip times (RTTs). In this paper, we propose an estimator to characterize the delays based on the cross‐correlation function. The tuning of the proportional‐integral (PI) controller is done using the estimator, and speed control experiments of the system for a small DC motor are done. As a result, it has been confirmed that the estimator is usable for tuning. Copyright © 2008 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.
Basic study of visual systems for sea pilot simulator training
Authors: Murai Koji , Okazaki Tadatsugi , Stone Laurie , Hayashi Yuji
Published: October 2008

Simulator training is a mandatory subject prior to the examination for a sea pilot's license. A sea pilot cadet trains using a ship handling simulator. Simulator systems consist of a ‘visual system’, a ‘bridge system’, and a ‘control system’ which are common simulator systems worldwide. The main training situations for sea pilots are ‘entering a port’ and ‘leaving a port’. Cadets need to develop their skills in simulator training. However, visual system does not provide a full 360° image around the ship. The complete 360° image is most important for cadets to obtain skills on how to navigate a ship into port. This letter proposes a visual system for training sea pilots when entering a port. Copyright © 2008 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.
Evaluation of pelvic ultrasonography in the diagnosis and differentiation of various forms of sexual precocity in girls
Authors: Badouraki M. , Christoforidis A. , Economou I. , Dimitriadis A. S. , Katzos G.
Published: October 2008

Objectives

This study was conducted to assess the role of pelvic ultrasound variables in discriminating between normal girls and girls with different forms of sexual precocity, and to establish reliable cut‐off limits of pelvic ultrasound measurements for differentiating between these conditions.

Methods

Eighty‐eight girls with different forms of sexual precocity (23 with premature thelarche, 15 with premature pubarche and 50 with central precocious puberty) were enrolled. All diagnoses were based on clinical examination with confirmation using the gonadotropin‐releasing hormone‐stimulation test. Additionally, 81 prepubertal girls, aged 0–10 years, were included as a control group. For statistical analysis and to facilitate comparisons, the groups were subdivided by age intervals (0–6, > 6–8 and > 8–10 years). All subjects underwent pelvic ultrasound examination for the measurement of uterine length, uterine volume, ovarian volume and the anteroposterior diameter at the fundus divided by the anteroposterior diameter at the cervix (fundal/cervical ratio, (F/C)). Finally, the morphological appearance of the ovaries was assessed.

Results

Patients with central precocious puberty had significantly higher values for all the ultrasound variables (with the exception of uterine length in the 1–6‐year age group) in comparison to normal girls. Patients with premature thelarche and patients with premature pubarche showed similar pelvic ultrasound parameters to those of normal girls. Ovarian volume was the best parameter for identifying patients with central precocious puberty (a cut‐off of 3.04 cm3 had a sensitivity of 100% and a specificity of 97.1% for age interval 0–6 years, a cut‐off of 3.35 cm3 had a sensitivity of 100% and a specificity of 89.5% for age interval > 6–8 years, and a cut‐off of 4.46 cm3 had a sensitivity of 80.8% and a specificity of 88.5% for age interval > 8–10 years). Uterine length was the best parameter for distinguishing between patients with central precocious puberty and patients with premature thelarche (a cut‐off of 3.185 cm had a sensitivity of 85.7% and a specificity of 91.7% for age interval 0–6 years, and a cut‐off of 3.83 cm had a sensitivity of 82.4% and a specificity of 90.9% for age interval > 6–8 years).

Conclusions

Ultrasound examination of the uterus and ovaries could serve as a complementary tool for the diagnosis of central precocious puberty and, consequently, for the early initiation of appropriate treatment. Copyright © 2008 ISUOG. Published by John Wiley & Sons, Ltd.
Prenatal diagnosis and outcome of echogenic fetal lung lesions
Authors: Cavoretto P. , Molina F. , Poggi S. , Davenport M. , Nicolaides K. H.
Published: October 2008

Objective

To describe the antenatal findings and outcome of fetuses with echogenic lung lesions.

Methods

This was a retrospective study of the prenatal sonographic features, antenatal management and outcome of 193 fetuses with an echogenic lung lesion diagnosed at 18–35 weeks of gestation. There were nine cases of congenital high airway obstruction syndrome (CHAOS), 170 cases of cystic adenomatoid malformation (CAM) and 14 cases of pulmonary sequestration (PS). A literature search was also carried out to compare our data with those of previous series.

Results

The prognosis in our series of fetuses with CHAOS was invariably poor, but the literature describes a handful of survivors after delivery by Cesarean section and ex‐utero intrapartum therapy (EXIT). Of the cases in our series with PS and no pleural effusions, more than 95% survived; in half of these cases the lesion resolved antenatally and in the other half sequestrectomy was carried out postnatally. In cases with PS and pleural effusions, successful treatment was provided by the placement of thoracoamniotic shunts or occlusion of the feeding blood vessel by ultrasound‐guided laser coagulation or injection of sclerosants. In cases with CAM and no hydrops, there was more than 95% survival and in up to half of the cases there was sonographic evidence of spontaneous antenatal resolution of the hyperechogenic lesion, which was confirmed by postnatal imaging in about 60% of the cases. Of the cases with CAM with hydrops managed expectantly, more than 95% died before or after birth. Of the cases with macrocystic CAM with hydrops, two‐thirds survived after placement of a thoracoamniotic shunt. In cases with microcystic CAM with hydrops, there is some evidence that open fetal surgery with lobectomy could improve survival but such treatment is highly invasive for the mother.

Conclusions

CHAOS is a severe abnormality, whereas CAM and PS are associated with a good prognosis. In a high proportion of fetuses with hyperechogenic lung lesion, there is spontaneous antenatal resolution and the underlying pathology may be transient bronchial obstruction. Copyright © 2008 ISUOG. Published by John Wiley & Sons, Ltd.
Dizygotic monochorionic twin pregnancy conceived following intracytoplasmic sperm injection treatment and complicated by twin‐twin transfusion syndrome and blood chimerism
Authors: Ekelund C. K. , Skibsted L. , Søgaard K. , Main K. M. , Dziegiel M. H. , Schwartz M. , Moeller N. , Roos L. , Tabor A.
Published: October 2008

We report a case of a dizygotic monochorionic twin pregnancy preceded by intracytoplasmic sperm injection treatment including assisted hatching. On ultrasound examination at 25 weeks' gestation the twins, which had been assumed to be monochorionic, were found to be of different sexes. Karyotyping and zygocity determination were performed on amniotic fluid and showed the twins to be dizygotic with normal female and male karyotypes. There were clinical and sonographic signs of twin–twin transfusion syndrome (TTTS), and Cesarean delivery was performed at 32 weeks' gestation. At birth the twins were phenotypically a normal male and a normal female. Histology of the placenta showed it to be monochorionic diamniotic. Blood chimerism was found postnatally as both infants had the karyotypes 46,XX[13]/46,XY[17]. Chimerism was not found in cells from a buccal swab at 6 months of age.

This is one of only a few reported cases of dizygotic monochorionic twins. Nearly all of these cases have been conceived after assisted reproductive technology procedures. It is of clinical importance to be aware of this rare phenomenon in relation to TTTS, prenatal screening and parental counseling. Copyright © 2008 ISUOG. Published by John Wiley & Sons, Ltd.
Changing findings in pentalogy of Cantrell in fetal life
Authors: Zidere V. , Allan L. D.
Published: October 2008

Pentalogy of Cantrell is the association of five features: a midline anterior ventral wall defect, a diaphragmatic defect, a cleft distal sternum, a defect of the apical pericardium with communication into the peritoneum, and an intracardiac defect. This is a complex abnormality that requires multiple surgical procedures, but which can be successfully treated postnatally with staged surgery. Three recent cases demonstrated features in prenatal life that were unexpected to us, and which we felt were worthy of description. The diagnosis of the pentalogy of Cantrell was made at 11, 16 and 14 weeks. Two of the three had an increased nuchal translucency measurement. All three fetuses had a major abdominal wall defect with a significant degree of protrusion of the cardiac ventricles outside the chest at the initial scan. At 20 and 26 weeks, the heart was seen to be within the chest with no protrusion, even of the apex. An intracardiac malformation was found prenatally in two of three cases. There were no karyotype anomalies and all three cases survived despite multiple operations. At the time of writing they were aged 2, 5 and 8 years. The ultrasound findings in all three cases showed an evolving pattern during gestation, with a greater degree of protrusion of the heart through the lower sternal defect into the exomphalos in the early scans than was present later. The possibility of an improvement in the findings has some bearing on counseling in early pregnancy in this complex condition. Copyright © 2008 ISUOG. Published by John Wiley & Sons, Ltd.
Validation of Quintero stage III sub‐classification for twin–twin transfusion syndrome based on visibility of donor bladder: characteristic differences in pathophysiology and prognosis
Authors: Murakoshi T. , Ishii K. , Nakata M. , Sago H. , Hayashi S. , Takahashi Y. , Murotsuki J. , Matsushita M. , Shinno T. , Naruse H. , Torii Y.
Published: October 2008

Objective

To validate the Quintero stage III subclassification for twin–twin transfusion syndrome (TTTS) based on visibility of the bladder of the donor twin.

Methods

Between July 2002 and August 2006, there were 131 pregnant Japanese women affected by severe TTTS before 26 weeks' gestation, treated with fetoscopic laser surgery at five centers in Japan, whose pregnancies continued beyond 22 weeks. Outcome data were available in all cases and surviving infants were followed up for at least 6 years. This study focused on the Stage III TTTS patients. These were subclassified into Stage III atypical (abnormal Doppler flow with visible donor bladder) and Stage III classical (abnormal Doppler flow with non‐visible donor bladder) groups. Perioperative data and postnatal outcomes were compared between the groups.

Results

Seven Stage I, 22 Stage II, 82 Stage III and 20 Stage IV pregnancies continued beyond 22 weeks. There was a significantly higher incidence of absent or reversed end‐diastolic velocity in the umbilical artery (UA‐AREDV) of the donor in Stage III atypical than in Stage III classical patients (83.8% vs. 53.3%, P = 0.004). Stage III atypical cases also had a significantly higher incidence of arterioarterial (AA) anastomoses (72.9% vs. 17.8%, P < 0.001) and intrauterine fetal demise (IUFD) of the donor (43.2% vs. 13.3%, P = 0.002). However, there were no differences in overall survival or in abnormal brain scans of surviving infants. Donors with both UA‐AREDV and AA anastomoses had a significantly higher incidence of IUFD compared with the others (53.3%, P < 0.001).

Conclusions

Quintero stage III atypical was characterized by a high incidence of AA anastomoses and UA‐AREDV of the donor, resulting in IUFD. Subclassification of Stage III based on visibility of the bladder of the donor twin was adequate for and compatible with differentiating prognosis and pathophysiology. Copyright © 2008 ISUOG. Published by John Wiley & Sons, Ltd.
Fetal cardiac output in monochorionic twins
Authors: Sueters M. , Middeldorp J. M. , Lopriore E. , Bökenkamp R. , Oepkes D. , Teunissen K. A. , Kanhai H. H. H. , Cessie S. Le , Vandenbussche F. P. H. A.
Published: October 2008

Objectives

To compare fetal cardiac output (CO) in donor and recipient twins of twin–twin transfusion syndrome (TTTS) pregnancies after laser therapy with that of monochorionic twins without TTTS and normal singletons.

Methods

In a longitudinal, prospective study, we sonographically assessed fetal CO in donors (n = 10) and recipients (n = 10) with TTTS after fetoscopic laser therapy, in monochorionic twins without TTTS (n = 20) and in normal singleton pregnancies (n = 20). The fetal CO of TTTS twins was determined 1 day and 1 week after laser treatment, and from then on every 2–4 weeks until birth. Twins without TTTS were examined biweekly until birth. Singletons were examined twice, with an 8‐week interval, at different gestational ages between 17 and 35 weeks.

Results

Absolute CO increased exponentially with advancing gestational age (P < 0.0001), and was significantly related to fetal weight in all groups (P < 0.0001). The median CO/kg in donors after laser therapy, recipients after laser therapy and non‐TTTS monochorionic twins was significantly higher than that in singletons (all P < 0.001). Median CO/kg in donors after laser therapy, recipients after laser therapy, and non‐TTTS monochorionic twins was not significantly different between groups.

Conclusions

Monochorionic twins with TTTS have higher CO after laser therapy than normal singletons. Copyright © 2008 ISUOG. Published by John Wiley & Sons, Ltd.
Value of prenatal magnetic resonance imaging in the prediction of postnatal outcome in fetuses with diaphragmatic hernia
Authors: Jani J. , Cannie M. , Sonigo P. , Robert Y. , Moreno O. , Benachi A. , Vaast P. , Gratacos E. , Nicolaides K. H. , Deprest J.
Published: October 2008

Objectives

To investigate the potential value of antenatally determined total fetal lung volume (TFLV) by magnetic resonance imaging (MRI) in the prediction of the postnatal survival in congenital diaphragmatic hernia (CDH).

Methods

We examined fetuses with isolated CDH, in which MRI was used at 22–38 weeks of gestation to measure TFLV and assess intrathoracic herniation of abdominal viscera, that were liveborn after 30 weeks of gestation and had postnatal follow‐up until death or discharge from hospital. Regression analysis was used to investigate the effect on survival of gestational age at diagnosis, observed to expected (o/e) TFLV, intrathoracic herniation of the liver, side of CDH, gestational age at MRI, institution, year and gestational age at delivery. In 76 fetuses measurements of o/e TFLV and the lung area to head circumference ratio (LHR) were performed within 2 weeks of each other; in these cases o/e TFLV and o/e LHR were compared for their prediction of postnatal survival.

Results

In the 148 cases that fulfilled the entry criteria, multiple regression analysis demonstrated that significant predictors of survival were the presence or absence of intrathoracic herniation of the liver and o/e TFLV. The area under the receiver–operating characteristics curves for prediction of postnatal survival from o/e TFLV was 0.786 (standard error, 0.059; P < 0.001) and that from o/e LHR was 0.743 (standard error, 0.069; P = 0.001).

Conclusions

In the assessment of fetuses with CDH, MRI‐based o/e TFLV is useful in the prediction of postnatal survival. Copyright © 2008 ISUOG. Published by John Wiley & Sons, Ltd.
Maternal serum placental growth factor at 11 + 0 to 13 + 6 weeks of gestation in the prediction of pre‐eclampsia
Authors: Akolekar R. , Zaragoza E. , Poon L. C. Y. , Pepes S. , Nicolaides K. H.
Published: October 2008

Objective

To investigate the potential value of maternal serum placental growth factor (PlGF) in first‐trimester screening for pre‐eclampsia (PE).

Methods

The concentration of PlGF at 11 + 0 to 13 + 6 weeks' gestation was measured in samples from 127 pregnancies that developed PE, including 29 that required delivery before 34 weeks (early PE) and 98 with late PE, 88 cases of gestational hypertension (GH) and 609 normal controls. The distributions of PlGF multiples of the median (MoM) in the control and hypertensive groups were compared. Logistic regression analysis was used to determine the factors with a significant contribution for predicting PE.

Results

In the control group significant independent contributions for log PlGF were provided by fetal crown–rump length, maternal weight, cigarette smoking and racial origin, and after correction for these variables the median MoM PlGF was 0.991. In the early‐PE and late‐PE groups PlGF (0.611 MoM and 0.822 MoM, respectively; P < 0.0001) and pregnancy‐associated plasma protein‐A (PAPP‐A) (0.535 MoM; P < 0.0001 and 0.929 MoM; P = 0.015, respectively) were reduced but in GH (PlGF: 0.966 MoM; PAPP‐A: 0.895 MoM) there were no significant differences from controls. Significant contributions for the prediction of PE were provided by maternal characteristics and obstetric history, serum PlGF and uterine artery pulsatility index (PI) and with combined screening the detection rates for early PE and late PE were 90% and 49%, respectively, for a false‐positive rate of 10%.

Conclusion

Effective screening for PE can be provided by a combination of maternal characteristics and obstetric history, uterine artery PI and maternal serum PlGF at 11 + 0 to 13 + 6 weeks' gestation. Copyright © 2008 ISUOG. Published by John Wiley & Sons, Ltd.
Three‐dimensional inversion rendering in the first‐ and early second‐trimester fetal brain: its use in holoprosencephaly
Authors: Timor‐Tritsch I. E. , Monteagudo A. , Santos R.
Published: October 2008

Objectives

To explore the feasibility and added value of three‐dimensional (3D) inversion rendering of the developing embryonic/fetal ventricular system, and to apply this display technique to enhance the sonographic examination of holoprosencephaly.

Methods

3D volumes of the embryonic/fetal brain were acquired from four normal fetuses at 8–11 postmenstrual weeks, and four fetuses diagnosed with holoprosencephaly between 9 and 14 postmenstrual weeks. The volumes were then analyzed offline to obtain inversion rendered 3D shapes of the ventricular systems.

Results

All inversion rendering displays were successful and provided the opportunity to study normal as well as pathological aspects of the early fetal brain.

Conclusions

Inversion rendering of early fetal brain ventricles is feasible and should be attempted if additional information about the early normal or pathological fetal brain is needed. It may have scientific value in embryologic or genetic studies. Copyright © 2008 ISUOG. Published by John Wiley & Sons, Ltd.
Inhibition of the thermal degradation of rigid poly(vinyl chloride) by dienophilic compounds
Authors: Abdel‐Naby Abir S. , Al‐Dossary Abeer O.
Published: October 2008

N‐(N′‐Arylamino)maleimide derivatives N‐(N′‐RPh)AMI (R = H, 2‐NO2, 4‐NO2, 2,4‐di‐NO2) were investigated as organic thermal stabilizers and costabilizers for rigid poly(vinyl chloride) (PVC) at 180°C in air. Their stabilizing efficiencies were evaluated by measuring the induction period (Ts, the period during which no evolved hydrogen chloride could be detected) and the dehydrochlorination rate as measured by continuous potentiometric determination, as well as the extent of discoloration. The stabilizing efficiencies were compared with those of some industrially used stabilizers. The results clearly revealed the greater efficiency of all of the investigated derivatives except the unsubstituted N‐(N′‐Ph)AMI, which was found to possess efficiency comparable with those of the reference stabilizers. The dinitro aminomaleimide [2,4‐di(NO2)AMI] exhibited the highest efficiency. The stabilizing efficiencies of the AMIs are attributed to the replacement of the labile chlorine atoms on the PVC chains by more thermally stable stabilizer moieties. An ionic mechanism is proposed that explains the stabilizing action. Mixing the investigated stabilizers with cyanoguanidine, which is known to act as an HCl absorber, led to a true synergistic effect. The effect of the degradation process of adding small amounts of K2CO3 to PVC stabilized with the materials under investigation also is discussed. J. VINYL ADDIT. TECHNOL., 2008. © 2008 Society of Plastics Engineers
Study of processability of poly(vinyl chloride): Effects of acrylic and chlorinated polyethylene impact modifiers, oil palm empty fruit bunch fiber, and mixing temperature
Authors: Abu Bakar Aznizam , Hassan Azman , Mohd Yusof Ahmad Fuad
Published: October 2008

The influence of acrylic impact modifier, chlorinated polyethylene (CPE) impact modifier, oil palm empty fruit bunch (OPEFB) fiber, and mixing temperature on the processability of poly(vinyl chloride) (PVC) compounds was investigated. The acrylic impact modifier was the most efficient additive in reducing the fusion time of the PVC, followed by the OPEFB fiber and the CPE impact modifier, whereas OPEFB was the most efficient in decreasing the melt viscosity of the compounds, followed by CPE and acrylic. A PVC compound containing 9 phr of CPE and 40 phr of OPEFB had high values of fusion time and end torque. The fusion time and melt viscosity of all of the PVC compounds decreased with increasing mixing temperature. J. VINYL ADDIT. TECHNOL., 2008. © 2008 Society of Plastics Engineers.
Spectroscopic, Thermal and Structural Studies of Aza‐aromatic Base Adducts of Cadmium Furoyltrifluoroacetonate
Authors: Marandi Farzin , Khosravi Maryam , Fun Hoong‐Kun
Published: October 2008

Three aza‐aromatic base adducts of cadmium(II) furoyltrifluoroacetonate, [Cd(4,4′‐bpy)(ftfa)2]n (1), [Cd(2,2′‐bpy)(ftfa)2] (2) and [Cd(dmp)(ftfa)2] (3) (“4,4′‐bpy”, “2,2′‐bpy”, “dmp” and “ftfa” are the abbreviations of 4,4′‐bipyridine, 2,2′‐bipyridine, 2,9‐dimethyl‐1,10‐phenanthroline and furoyltrifluoroacetonate, respectively) have been synthesized and characterized by elemental analysis and IR, 1H NMR and 13C NMR spectroscopy and studied by thermal as well as X‐ray crystallography. The single‐crystal structure of these complexes shows that the coordination number of the CdII ions are six with two N‐donor atoms from aza‐aromatic base ligands and four O‐donors from two the furoyltrifluoroacetonates. The supramolecular features in these complexes are guided/controlled by weak directional intermolecular interactions.
Frameworks Tuned by Different Anions via Charge‐Assisted Weak Hydrogen Bonds
Authors: Wei Wei , Wu Mingyan , Huang Yougui , Gao Qiang , Jiang Feilong , Hong Maochun
Published: October 2008

Reactions of Co(ClO4)2·6H2O, Cu(NO3)2·3H2O with 4,4′‐dipyridylsulfide (dps) give rise to coordination polymers {[Co(dps)2(DMF)2]·2(ClO4)·2dps}n (1) and {[Cu(dps)2(DMF)(H2O)]·(PF6)·(NO3)}n (2) (DMF = formydimethylamine), respectively. X‐ray diffraction analyses reveal that compound 1 has a one dimensional (1D) chain structure, whereas compound 2 is built of the non‐interpenetrating wave‐like (4, 4) nets. Close inspection of the abundant charge‐assisted weak hydrogen bonds (C‐H···X, X = O, F) between the anions and frameworks in these compounds reveals that the appearance of anion may have a subtle effect on the framework topology. Furthermore, quite few examples of framework holding two different anions only via weak effects as 2 were observed in coordination polymers.
Hydrothermal Synthesis, Crystal Structure, and Thermal Stability of Two New Metal Phosphonates with a Pillared Layered Structure
Authors: Zhang Jing , Li Jing , Sun Zhen‐Gang , Zhao Yan , Zhu Yan‐Yu , Zhang Na , Liu Lei , Dalian Xin Lu
Published: October 2008

Two new metal phosphonates with a 3D pillared layered framework based on N,N′‐piperazinebis(methylenephosphonic acid), H2O3PCH2NC4H8NCH2PO3H2 (H4L), Sn[O3PCH2NHC4H8NHCH2PO3] (1) and Pb3(OH)2[O3PCH2NC4H8NCH2PO3] (2), have been synthesized under hydrothermal conditions and structurally characterized by single‐crystal X‐ray diffraction as well as with infrared spectroscopy, elemental analysis and thermogravimetric analysis. For compound 1, each ψ‐square pyramidal SnO4 unit is in turn corner‐shared by four CPO3 tetrahedral from four different phosphonate ligands to form two‐dimensional inorganic puckered layers in ab planes. In compound 2, the complicated inorganic layer (bc planes) is built up of ψ‐PbO4N, PbO6 and CPO3 polyhedra. The overall structure for two compounds may be described in terms of alternating inorganic infinite layers and organic pillars {CH2N(C2H4)2NCH2}, to form a 3D pillared layered structure.
Two Disparate 2‐fold Interpenetrating Frameworks Constructed from ZnII, 4,4′‐Dipyridyl Disulfide and Maleic/ Fumaric Acid
Authors: Yang Xiaogang , Li Dongsheng , Fu Feng , Tang Long , Yang Jiyuan , Wang Lili , Wang Yaoyu
Published: October 2008

The reaction of ZnII nitrate with maleic acid (H2mal) / fumaric acid (H2fum) and 4,4′‐dipyridyl disulfide (4‐pds) resulted under same conditions in two distinct interpenetrated compounds, namely [Zn(4‐dps)2(H2O)2]·2Hmal (1) and [Zn(4‐dps)(fum)] (2). In 1, Hmal anion adopts bridging mode based on hydrogen bonding, affording a 2‐fold parallel interpenetrated 3D→3D α‐Po net hydrogen‐bonded framework, in which 1D double‐stranded chains are formed, and then extended to a 3D supramolecular architecture combining second‐sphere hydrogen‐bonded interactions. For 2, fum dianion takes on bis‐dentate bridging coordination fashion, furnishing a 2‐fold interpenetrated 2D→2D (4,4) layered coordination network, in which the tetrahedral ZnII atoms are interlinked by 4‐dps and fum. Additionally, the compound 2 shows strong fluorescence in the solid state at room temperature.
Mono‐ and Perfluoroaryliodine(III) Cyano Compounds – Synthesis, Reactivity, and Structure
Authors: Frohn Hermann‐Josef , Hirschberg Markus Egon , Boese Roland , Bläser Dieter , Flörke Ulrich
Published: October 2008

C6F5I(CN)2 and x‐FC6H4I(CN)2 (x = 2, 3, 4) were isolated from reactions of the corresponding aryliodine difluorides ArIF2 and a stoichiometric excess of Me3SiCN in CCl3F (0 °C) or CH2Cl2 (20 °C), respectively. In addition, x‐FC6H4I(CN)2 compounds were synthesized in good yields on alternative routes, namely from 3‐ or 4‐FC6H4I(OC(O)CH3)2 or 4‐FC6H4I(OC(O)CF3)2 or from 4‐FC6H4IO and Me3SiCN in CH2Cl2 at 20 °C. In the 1 : 1 reaction of C6F5IF2 and Me3SiCN a lower temperature was necessary to suppress partial disubstitution and to obtain the first example of a new type of aryliodine(III) cyanide compounds, C6F5I(CN)F. 4‐FC6H4I(CN)F could be isolated from the equimolar reaction of 4‐FC6H4IF2 and Me3SiCN in CH2Cl2 even at 20 °C. The new products were characterized by multi‐NMR and Raman spectroscopy. The molecular structures of C6F5I(CN)2, 3‐ and 4‐FC6H4I(CN)2, C6F5I(CN)F, and 4‐FC6H4I(CN)F are discussed and compared with that of C6F5IF2. The reactivity of C6F5I(CN)F towards fluoride acceptors EFn (BF3, AsF5) and RxEX−x (C6F5SiF3, C6H5SiF3, C6H5PF4, Me3SiCl, Me3SiC6F5) were investigated and showed differing reaction patterns (fluoride abstraction, aryl transfer, chloride transfer). Besides the molecular entities C6F5I(CN)F and C6F5I(CN)Cl, the corresponding iodonium salts [C6F5(CN)I][BF4] and [C6F5(CN)I][AsF6] were isolated. The thermal stability of ArI(CN)2 and ArI(CN)F, neat and in solution, as well as the reactivity of 4‐FC6H4I(CN)2 towards the Lewis acid BF3 are reported.
Hydrates of 5‐Amino‐1H‐tetrazolium Halogenide Salts – Starting Materials for the Synthesis of Energetic Compounds
Authors: von Denffer Moritz , Klapötke Thomas M. , Miró Sabaté Carles
Published: October 2008

5‐Amino‐1H‐tetrazolium halogenide salts (Cl, Br, I) can be used to synthesize energetic materials by metathesis reactions. Hydrate halide salts of 5‐amino‐1H‐tetrazole (5‐AtHX, X = Cl, Br, I) were synthesized and characterized by crystal structure determination. A detailed description of their structure is given in this manuscript and the bonding parameters are compared to the calculated values (MP2 and B3LYP). In addition, the compounds were characterized by using elemental analysis, mass spectrometry, vibrational spectroscopy (IR and Raman) and multinuclear NMR (1H, 13C, 15N) spectroscopy and differential scanning calorimetry (DSC). Lastly, attempts to synthesize the fluoride and the energetically interesting azide salts are discussed.