bluuebunny/crossref_metadata_2025_split huggingface dataset:
Evaluation of twin growth status at birth using individualized growth assessment: Comparison with conventional methods
Authors: Xu Bishong , Deter Russell L. , Milner Lizabeth L. , Hill Reba M. 
Published: February 2007

AbstractObjective: We sought to evaluate the growth status of twins at birth using individualized growth assessment methods and to compare this assessment with that obtained with conventional methods.Study design: Twenty twin pregnancies were studied longitudinally with ultrasound. Measurements of the head and abdominal cubes (A, B), head circumference (HC), abdominal circumference (AC), thigh circumference (ThC), and femur diaphysis length (FDL) made in the 2nd trimester were used to specify Rossavik growth models for each parameter in each fetus. These models were used to predict weight (WT), HC, AC, ThC, and crown–head length (CHL) at birth. Actual birth measurements made within 24 hours of delivery were compared to predicted values, the latter corrected using singleton [corrects for both technical problems (TP)] or twin [corrects for both technical problems (TP) and decreased soft‐tissue deposition (DSTD)] correction factors where appropriate. Two sets of growth potential realization index (GPRI) values and their corresponding neonatal growth assessment scores (NGAS) were calculated and compared to previously established normal values. Birth measurements were compared with appropriate population age‐specific size curves. These data were used to characterize and classify the growth status of each twin neonate.Results: Individualized growth assessment identified five primary types of growth outcomes: normal (Group I, 45%); primarily DSTD (Group II, 22.5%); IUGR (Group III, 15%); above average soft‐tissue deposition (Group IV, 5%); and growth acceleration (Group V, 7.5%). Within Group I was a subgroup with evidence of DSTD (Group Ib, 33.3% of Group I). Group II could be divided into two subgroups, one with only DSTD (Group IIa, 44.4% of Group II) and one with both DSTD and other growth abnormalities (Group IIb, 55.6% of Group II). Group III had multiple growth abnormalities which were more severe than those seen in Group II. All normal neonates were AGA and had virtually all anatomic parameters within their respective normal ranges. Of the neonates with definite evidence of IUGR (Groups IIb and III), only 4 of 11 (36.4%) were SGA and only 6 of 11 (54.5%) had any of the five anatomic parameters below their respective normal ranges. Only 1 of 3 (33.3%) of neonates with growth acceleration was LGA and none (0%) of the five anatomic parameters were above their respective normal ranges.Conclusions: Individualized growth assessment methods provide a more comprehensive assessment of growth outcome in twins and detect a decrease in soft‐tissue deposition not identifiable with conventional growth assessment procedures. The latter procedures are also less sensitive in the detection of both IUGR and growth acceleration. © 1995 John Wiley & Sons, Inc.
Causes of increasing width of right anterior extrarenal space seen in ultrasonographic examinations
Authors: Chen Jyh‐Jou , Changchien Chi‐Sin , Kuo Chung‐Huang 
Published: February 2007

AbstractThe right anterior extrarenal space is composed of the perirenal fascia, the right anterior perirenal space, the right anterior pararenal space, and the liver capsule. To clarify the probable causes of an increasing width of the right anterior extrarenal space, the width was measured using ultrasonography for a period of 8 months. The right anterior extrarenal space was measured 3 cm from the superior renal pole and the smallest width obtained in several different scan planes was used. In 1,114 ultrasound examinations, 35 patients were found to have an increased width of the right anterior extrarenal space. Among the 35 cases, the common probable causes for such a condition were found in 27 cases. Eight patients had hyperechogenicity in the right pararenal space, a condition considered to be due to an acute inflammation, including acute pancreatitis, acute cecal diverticulitis, acute appendicitis, ischemic bowel, acute cholangitis, liver abscess, and penetrated duodenal ulcer. Chronic inflammations of an adjacent organ, a previous history of laparotomy, a malignancy with peritoneal metastases, and treatment with corticosteroid were considered the causes behind the condition in the 19 patients with normal echogenicity. For the remaining 8 patients, causes were not found during the follow‐up period. This study indicates that life‐threatening diseases, such as acute or chronic inflammatory diseases and malignancy of the abdomen, could be the cause of an increase in the width of this space. © 1995 John Wiley & Sons, Inc.
Relationship between portal blood flow measured by image‐directed doppler ultrasonography and hepatic blood flow measured by indocyanine green constant infusion in patients with cirrhosis
Authors: Bolognesi Massimo , Sacerdoti David , Merkel Carlo , Gatta Angelo 
Published: February 2007

AbstractThe validity of portal blood flow measurement in image‐directed Doppler ultrasound (PBF‐IDU) is still under debate.In this study PBF‐IDU has been compared with hepatic blood flow measured by the indocyanine green constant infusion technique (HBF‐ICG), which is the reference invasive method with which to measure total hepatic blood flow in man (ie, the sum of hepatic artery and portal vein blood flow).In 27 cirrhotic patients with hepatopetal portal blood flow, PBF‐IDU was measured by multiplying the portal vein cross‐sectional area by the averaged mean velocity of blood in the vessel. About 1 hour later HBF‐ICG was measured during hepatic vein catheterization performed to evaluate portal hypertension. In 19 of 27 patients, intra‐hepatic arterial resistance indices were also measured.PBF‐IDU and HBF‐ICG were 1.010 ± 0.555 L/min (M ± SD) and 1.496 ± 0.731 L/min, respectively. Blood flow measured by the two methods showed a close correlation (r = 0.80, p < 0.001). The regression line showed that HBF‐ICG was systematically higher than PBF‐IDU (mean difference + 29 ± 30%). The hepatic artery component of HBF‐ICG probably accounted for the difference. An inverse correlation was found between the differences between the two procedures and intrahepatic arterial resistance indices (r = −0.52, p = 0.04), which may be considered indirect parameters of arterial supply. It can be concluded that image‐directed Doppler ultrasound is a sufficiently accurate method to measure portal blood flow in cirrhotics. © 1995 John Wiley & Sons, Inc.
Sonohysterography of the uterine cavity: Preliminary investigations
Authors: Gaucherand Pascal , Piacenza Jean M. , Salle Bruno , Rudigoz René Ch. 
Published: February 2007

AbstractObjective: To compare sonohysterography (SH), in the exploration of the uterine cavity, with classical transvaginal sonography (TVS), hysterography (HSG), and hysteroscopy.Study design: 104 consecutive patients evaluated for uterine disorders underwent both TVS and SH. SH was obtained by distension of the uterine cavity with the instillation of an isotonic saline solution; 36 patients also underwent HSG; 82 women underwent surgery. Histologic findings were considered as gold standard. The criteria used to compare these methods were sensitivity, specificity, and negative and positive predictive values (NPV, PPV) for identifying pathology.Results: 3 instillation failures occurred. SH was found to be more effective (sensitivity 94%, specificity 98%) than HSG (sensitivity 67%, specificity 94%). The difference between TVS and SH was less marked, SH showing some superiority (sensitivity 88%, specificity 98%) to TVS (sensitivity 77%, specificity 93%).Conclusion: SH represents an improvement over conventional TVS and is fully capable of replacing HSG for the study of the uterine cavity. © 1995 John Wiley & Sons, Inc.
Visceral slide for intraperitoneal adhesions? A prospective study in 48 patients with surgical correlation
Authors: Uberoi R. , D'Costa H. , Brown C. , Dubbins P. 
Published: February 2007

AbstractBowel perforation in patients undergoing laparoscopic surgery is an uncommon but serious complication. Bowel adherent to the anterior abdominal wall due to adhesions is considered a particular risk. It has been suggested that transabdominal ultrasound can reliably predict the presence of intraperitoneal adhesions. Normal bowel excursions (visceral slide) in 15 volunteers with no history of surgery or peritonitis and in 48 patients undergoing abdominal surgery were evaluated. Visceral slide during spontaneous respiration (SRSL) with manual compression (MCSL) and exaggerated respiration (ESL) was assessed in all 4 quadrants. Adhesions were found in 43 quadrants (12 in the RUQ, 6 in the LUQ, 14 in the RIF, and 11 in the LIF) in 21 patients at surgery. Reduced SRSL detected fibrous adhesions in 6 of 15 quadrants, but only 3 of 28 fibrinous adhesions, with an overall sensitivity of 21%, specificity of 94%, and accuracy of 76%. MCSL detected 9 of 15 fibrous and 9 of 28 fibrinous adhesions, with an overall sensitivity of 42%, specificity of 73.5%, and accuracy of 62%. ESL detected 6 of 15 fibrous and 3 of 28 fibrinous adhesions, with an overall sensitivity of 20%, specificity of 76%, and accuracy of 63%. Preliminary results suggest that ultrasound can detect adhesions preoperatively, but the overall sensitivity is poor and the number of false‐positives and false‐negatives make it unreliable for routine use. © 1995 John Wiley & Sons, Inc.
Hepatic venous Doppler waveforms: Changes in pregnancy
Authors: Roobottom C. A. , Hunter J. D. , Weston M. J. , Dubbins P. A. 
Published: February 2007

AbstractA total of 75 fasted healthy normal volunteers were examined during various stages of pregnancy. Examinations were performed in a supine position using an Acuson 128 ultrasound scanner with a 3.5 MHz transducer. Doppler interrogation of the middle hepatic vein was made during quiet respiration by one of three examiners. The Doppler waveforms were subsequently assessed blindly by one of the authors and categorized as normal, damped, or flat. Between 12 and 20 weeks, the majority of patients had normal hepatic pulsatility (64%) with 20% damped and 16% flat. Between 20 and 30 weeks there was a significant change (p > 0.001) with 68% being flat, 20% damped, and only 12% normal. In the last 10 weeks of pregnancy the changes were more marked: 80% were flat, 12% dampened, and 8% normal. There was a profound change in hepatic venous pulsatility during pregnancy. Hepatic waveforms changed from their normal pulsatile nature to become completely flat with increasing gestation. These changes were more frequent and more marked the further gestation progressed. © 1995 John Wiley & Sons, Inc.
Early fetal circulation in pregnancies complicated by retroplacental hematoma
Authors: Rizzo Giuseppe , Capponi Alessandra , Soregaroli Mirella , Arduini Domenico , Romanini Carlo 
Published: February 2007

AbstractThe objective of this study was to investigate the effects in early gestation of retroplacental hematomas on Doppler indices measured in different fetal vascular districts and to relate these changes, if any, to the volume of hematoma and pregnancy outcome. Thirty‐eight pregnancies complicated by bleeding and ultrasonographic findings of retroplacental hematomas were considered for this study. Menstrual age ranged between 9 and 14 weeks. Blood flow velocity waveforms were measured in the umbilical artery, descending aorta, middle cerebral artery, and inferior vena cava. The pulsatility index in arterial vessels was calculated as well as the percentage reverse flow in the inferior vena cava. The values obtained were compared to previously constructed reference limits. No significant differences were found for any of the Doppler indices when the values obtained in pregnancies complicated by retroplacental hematomas were compared to the reference limits. Furthermore no significant relationships were found between the Doppler indices and either the size of hematoma or pregnancy outcome. In conclusion, retroplacental hematoma does not induce hemodynamic effects in the fetal circulation before 14 weeks, menstrual age. These data do not support the use of Doppler ultrasonography in early gestation for pregnancies complicated by bleeding and retroplacental hematomas. © 1995 John Wiley & Sons, Inc.
Quantitative characterization of color Doppler images: Reproducibility, accuracy, and limitations
Authors: Delorme Stefan , Weisser Gerald , Zuna Ivan , Fein Martin , Lorenz Adolf , van Kaick Gerhard 
Published: February 2007

AbstractA computer‐based quantitative analysis for color Doppler images of complex vascular formations is presented. The red‐green‐blue‐signal from an Acuson XP10 is frame‐grabbed and digitized. By matching each image pixel with the color bar, color pixels are identified and assigned to the corresponding flow velocity (color value). Data analysis consists of delineation of a region of interest and calculation of the relative number of color pixels in this region (color pixel density) as well as the mean color value. The mean color value was compared to flow velocities in a flow phantom. The thyroid and carotid artery in a volunteer were repeatedly examined by a single examiner to assess intra‐observer variability. The thyroids in five healthy controls were examined by three experienced physicians to assess the extent of inter‐observer variability and observer bias. The correlation between the mean color value and flow velocity ranged from 0.94 to 0.96 for a range of velocities determined by pulse repetition frequency. The average deviation of the mean color value from the flow velocity was 22% to 41%, depending on the selected pulse repetition frequency (range of deviations, −46% to +66%). Flow velocity was underestimated with inadequately low pulse repetition frequency, or inadequately high reject threshold. An overestimation occurred with inadequately high pulse repetition frequency. The highest intra‐observer variability was 22% (relative standard deviation) for the color pixel density, and 9.1% for the mean color value. The inter‐observer variation was approximately 30% for the color pixel density, and 20% for the mean color value. In conclusion, computer assisted image analysis permits an objective description of color Doppler images. However, the user must be aware that image acquisition under in vivo conditions as well as physical and instrumental factors may considerably influence the results. © 1995 John Wiley & Sons, Inc.
Assessment of fetal breathing movements using three different ultrasound modalities
Authors: Bruner Joseph P. , Coggins Teresa 
Published: February 2007

AbstractTwenty‐five consecutive women in the third trimester of pregnancy were studied to determine the presence or absence of fetal breathing movements using three different ultrasound imaging techniques. Using real‐time B‐mode observation of the fetal trunk as the standard, image‐directed pulsed wave Doppler insonation of the umbilical vein confirmed the presence of breathing movements with a sensitivity of 100% and the absence of breathing movements with a specificity of 100%. The sensitivity and specificity of color Doppler imaging of the fetal naso‐and oropharynx for the presence or absence of fetal breathing movements were 96% and 100%, respectively. In the current study, the detection of fetal breathing movements by three different ultrasound modalities was virtually interchangeable. © 1995 John Wiley & Sons, Inc.
Ionization of anabolic steroids by adduct formation in liquid chromatography electrospray mass spectrometry
Authors: Pozo Oscar J. , Van Eenoo Peter , Deventer Koen , Delbeke Frans T. 
Published: February 2007

AbstractThe ionization of 46 anabolic steroids has been studied. The absence of basic or acidic moieties in most of these analytes makes their direct ionization as [M + H]+ by atmospheric pressure interfaces difficult. The formation of adducts with different components of the mobile phase has been found to be an efficient way to ionize anabolic steroids by electrospray. Different mobile phases using methanol (MeOH) or acetonitrile as organic solvent and HCOOH, Na+ or NH4+ as additives have been tested to favor the adduct formation. A direct correlation between the chemical structure of the anabolic steroid and the possibility to ionize it in a particular chromatographic condition has been found. According to their ionization, anabolic steroids can be divided into seven different groups depending on both the nature and the relative position of their functional groups. The formation of different adducts such as [M + Na + MeOH]+ or [M + H + CH3 CN − H2O]+ is required in order to ionize some of these groups and the optimal mobile phase composition for each group of anabolic steroids is proposed. Despite the ionization limitations due to their chemical structure, most of tested anabolic steroids could be ionized using the adduct formation approach. Copyright © 2007 John Wiley & Sons, Ltd.
Holocene colluvial (debris‐flow and water‐flow) processes in eastern Norway: stratigraphy, chronology and palaeoenvironmental implications
Authors: Sletten K. , Blikra L. H. 
Published: February 2007

AbstractVery little is known about the temporal pattern and the palaeoenvironmental implications of Holocene colluvial processes (debris‐flow and water‐flow processes) in eastern Norway. In this study, well‐dated sedimentary successions from 19 deep excavations are used to reconstruct Holocene colluvial activity in upper Gudbrandsdalen, eastern Norway. Following deglaciation, debris‐flow and water‐flow events have been common in upper Gudbrandsdalen throughout the Holocene, with 62% of the recognised debris‐flow and water‐flow units deposited prior to 5000 cal. yr BP. Relatively high colluvial activity is recorded at ca. 8600–7400, 2400–1900 and 800–400 cal. yr BP, with a conspicuous peak at ca. 8500–8100. Periods of relatively low colluvial activity are recorded at ca. 7100–6500, 5900–5300 and 3500–2500 cal. yr BP. Two different weather situations, unusually heavy rains and warm periods during the snowmelt season, are responsible for triggering colluvial processes in this area. These different weather situations may in turn be related to different climatic conditions. Copyright © 2007 John Wiley & Sons, Ltd.
Robust Nash Equilibrium in multi‐model LQ differential games: analysis and extraproximal numerical procedure
Authors: Jiménez‐Lizárraga Manuel , Poznyak Alex 
Published: February 2007

AbstractThis paper tackles the problem of finding a Nash equilibrium for a multi‐model differential game. Player's dynamics is governed by an ordinary differential equation with unknown parameters (Multi‐Model Representation) from a given finite set. The problem consists in the designing of min–max strategies for each player which guarantee an equilibrium for the worst‐case scenario. Based on the Robust Maximum Principle necessary conditions for a game to be in Robust Nash Equilibrium are derived. The LQ differential games are considered in detail. It is shown that the initial min–max differential game may be converted into a standard static game given in a multi‐dimensional simplex. A numerical procedure for resolving the LQ differential game is designed. Copyright © 2007 John Wiley & Sons, Ltd.
Conjugated polymers with tethered electron‐accepting moieties as ambipolar materials for photovoltaics
Authors: Cravino Antonio 
Published: February 2007

AbstractConjugated polymers are of increasing interest as semiconductors for soft (opto)electronic devices, including photovoltaic elements. A promising conversion of solar energy into electrical energy is possible with blends of soluble electron donor‐type conjugated polymers and fullerenes as electron‐acceptor, transporting component. This approach, called bulk‐heterojunction, suggested the preparation of intrinsic ambipolar materials to control simultaneously the electronic and morphological properties. On these bases, the covalent grafting of acceptor moieties onto conjugated backbones seemed attractive for the preparation of intrinsically ambipolar polymeric materials (‘double‐cable’ polymers) as an alternative to donor–acceptor composites. The design, characterisation and application of this novel class of polymers are reviewed taking into account the current understanding of organic photovoltaics. Copyright © 2007 Society of Chemical Industry
Monodisperse magnetic nanoparticles for biomedical applications
Authors: Xu Chenjie , Sun Shouheng 
Published: February 2007

AbstractMagnetic nanoparticles that are superparamagnetic with high saturation moment have great potential for biomedical applications. Solution‐phase syntheses have recently been applied to make various kinds of monodisperse magnetic nanoparticles with standard deviation in diameter of less than 10%. However, the surface of these nanoparticles is coated with a layer of hydrocarbon molecules due to the use of lipid‐like carboxylic acid and amine in the syntheses. Surface functionalization leads to the formation of water‐soluble nanoparticles that can be further modified with various biomolecules. Such functionalization has brought about several series of monodisperse magnetic nanoparticle systems that have shown promising applications in protein or DNA separation, detection and magnetic resonance imaging contrast enhancement. The goal of this mini review is to summarize the recent progress in the synthesis and surface modification of monodisperse magnetic nanoparticles and their applications in biomedicine. Copyright © 2007 Society of Chemical Industry
III‐V concentrator solar cell reliability prediction based on quantitative LED reliability data
Authors: Vázquez Manuel , Algora Carlos , Rey‐Stolle Ignacio , González José Ramón 
Published: February 2007

AbstractIII‐V Multi Junction (MJ) solar cells based on Light Emitting Diode (LED) technology have been proposed and developed in recent years as a way of producing cost‐competitive photovoltaic electricity. As LEDs are similar to solar cells in terms of material, size and power, it is possible to take advantage of the huge technological experience accumulated in the former and apply it to the latter. This paper analyses the most important parameters that affect the operational lifetime of the device (crystalline quality, temperature, current density, humidity and photodegradation), taking into account experience on the reliability of LEDs. Most of these parameters are less stressed for a III‐V MJ solar cell working at 1000 suns than for a high‐power LED. From this analysis, some recommendations are extracted for improving the long‐term reliability of the solar cells. Compared to high‐power LEDs based on compound semiconductors, it is possible to achieve operational lifetimes higher than 105 hours (34 years of real‐time operation) for III‐V high‐concentration solar cells. Copyright © 2007 John Wiley & Sons, Ltd.