bluuebunny/crossref_metadata_2025_split huggingface dataset:
Assessment of the impact of key terrestrial observing systems using DMI‐HIRLAM
Authors: Amstrup Bjarne 
Published: June 2008

AbstractFollowing a EUCOS decision to make an assessment of the impact on NWP forecasts of different components of the current observing systems in various combinations, a number of OSEs (Observing System Experiments) have been made by a number of NWP centres, with some running global models and some limited‐area models. The Danish Meteorological Institute (DMI) carried out OSEs with the limited‐area model HIRLAM. The following runs were made by DMI (two periods, one month each): (1) A baseline system (BL); (2) BL + all aircraft wind and temperature data; (3) BL + non‐GUAN radiosonde winds; (4) BL + non‐GUAN radiosonde temperature and wind; (5) BL + wind profiler; (6) as (4) + aircraft wind and temperature; (7) as (4) + non‐GUAN radiosonde humidity; (8) as BL + all in situ data (full combined system); and (9) BL + E‐AMDAR only (no ACARS and no traditional AIREPs). The lateral boundaries for these OSEs were provided by runs made by ECMWF, which was one of the centres to make OSEs with a global model.The main conclusions are that the radiosonde data are the most important data, closely followed by the aircraft data, and that aircraft data and radiosonde data are complementary and not redundant data. Furthermore the results show that it is important to have both wind and temperature profile data; wind data alone produce much poorer impact. Copyright © 2008 Royal Meteorological Society
QSAR Models for the Dermal Penetration of Polycyclic Aromatic Hydrocarbons Based on Gene Expression Programming
Authors: Wang Tao , Si Hongzong , Chen Pingping , Zhang Kejun , Yao Xiaojun 
Published: June 2008

AbstractGene Expression Programming (GEP) is a novel machine learning technique. The GEP is used to build nonlinear quantitative structure activity relationship model for the prediction of the Percent of Applied Dose Dermally Absorbed (PADA) over 24 h for polycyclic aromatic hydrocarbons. This model is based on descriptors which are calculated from the molecular structure. Three descriptors are selected from the descriptors pool by Heuristic Method (HM) to build a multivariable linear model. The GEP method produced a nonlinear quantitative model with a correlation coefficient and a mean error of 0.92 and 4.70 for the training set, 0.91 and 7.65 for the test set, respectively. It is shown that the GEP predicted results are in good agreement with experimental ones.
Comparative analysis of the gas‐phase reactions of cylindrospermopsin and the difference in the alkali metal cation mobility
Authors: Dörr Felipe Augusto , Tomaz José Carlos , Lopes Norberto Peporine , Pinto Ernani 
Published: June 2008

AbstractCylindrospermopsin (CYN) belongs to a group of toxins produced by several strains of freshwater cyanobacteria. It is a compact zwitterionic molecule composed of a uracil section and a tricyclic guanidinium portion with a primarily hepatotoxic effect. Using low multi‐stage and high‐resolution mass spectrometry, the gas‐phase reactions of this toxin have been investigated. Our data show that collision‐induced dissociation (CID) spectra of CYN are dominated by neutral losses, and three major initial fragmentation pathways are clearly distinguishable. Interestingly, comparative analysis of protonated and cationizated molecules showed a significant difference in the balance of the SO3 and terminal ring elimination. These data indicate that the differential ion mobility of H+, Li+, Na+ and K+ leads to different fragmentation pathways, giving rise to mass spectra with different profiles. Copyright © 2008 John Wiley & Sons, Ltd.
Isobaric metabolite interferences and the requirement for close examination of raw data in addition to stringent chromatographic separations in liquid chromatography/tandem mass spectrometric analysis of drugs in biological matrix
Authors: Yan Zhengyin , Maher Noureddine , Torres Rhoda , Cotto Carlos , Hastings Becki , Dasgupta Malini , Hyman Rolanda , Huebert Norman , Caldwell Gary W. 
Published: June 2008

AbstractIn addition to matrix effects, common interferences observed in liquid chromatography/tandem mass spectrometry (LC/MS/MS) analyses can be caused by the response of drug‐related metabolites to the multiple reaction monitoring (MRM) channel of a given drug, as a result of in‐source reactions or decomposition of either phase I or II metabolites. However, it has been largely ignored that, for some drugs, metabolism can lead to the formation of isobaric or isomeric metabolites that exhibit the same MRM transitions as parent drugs. The present study describes two examples demonstrating that interference caused by isobaric or isomeric metabolites is a practical issue in analyzing biological samples by LC/MS/MS. In the first case, two sequential metabolic reactions, demethylation followed by oxidation of a primary alcohol moiety to a carboxylic acid, produced an isobaric metabolite that exhibits a MRM transition identical to the parent drug. Because the drug compound was rapidly metabolized in rats and completely disappeared in plasma samples, the isobaric metabolite appeared as a single peak in the total ion current (TIC) trace and could easily be quantified as the drug since it was eluted at a retention time very close to that of the drug in a 12‐min LC run. In the second example, metabolism via the ring‐opening of a substituted isoxazole moiety led to the formation of an isomeric product that showed an almost identical collision‐induced dissociation (CID) MS spectrum as the original drug. Because two components were co‐eluted, the isomeric product could be mistakenly quantified and reported by data processing software as the parent drug if the TIC trace was not carefully inspected. Nowadays, all LC/MS data are processed by computer software in a highly automated fashion, and some analysts may spend much less time to visually examine raw TIC traces than they used to do. Two examples described in this article remind us that quality data require both adequate chromatographic separations and close examination of raw data in LC/MS/MS analyses of drugs in biological matrix. Copyright © 2008 John Wiley & Sons, Ltd.
Surface roughening of a non‐tapered open tubular emitter for improved electrospray ionization mass spectrometry performance at low flow rates
Authors: Su Shuqin , Marecak Dale , Oleschuk Richard D. 
Published: June 2008

AbstractA non‐tapered open tubular emitter with 75 µm internal diameter (i.d.) and 360 µm external diameter (o.d.) was developed by simply grinding the exit aperture of a fused‐silica capillary. The roughened emitter, with a relatively large aperture, generates stable electrospray signals (generally <5% relative standard deviation (RSD) for most conditions studied) at less than 500 nL/min flow rates, and was characterized with atomic force microscopy. The surface treatment greatly extends the operational range of an open tubular emitter to lower flow rates, compared to that of a cleaved capillary with similar dimensions. The stabilized nanoelectrospray is attributed to the increased surface roughness and modified wetting characteristics of the emitter exit resulting from grinding. Electrospray performance was evaluated, and as a result of the enhanced sensitivity from a roughened emitter, five femtomoles of leucine enkephalin were detected at a 50 nL/min flow rate with a signal to noise (S/N) ratio of 48. Furthermore, trypsin‐digested bovine serum albumin (BSA) was used to demonstrate the application of the emitter in protein identification, giving a sequence coverage of 60%. These emitters are robust, and may become a facile alternative to tapered emitters at moderate nano flow rates (e.g. 50 to 500 nL/min). Copyright © 2008 John Wiley & Sons, Ltd.
Correlation between nuchal translucency and nuchal skin‐fold measurements in Down syndrome and unaffected fetuses
Authors: Maymon R. , Zimerman A. L. , Weinraub Z. , Herman A. , Cuckle H. 
Published: June 2008

AbstractObjectiveTo assess whether there is a correlation between nuchal translucency (NT) and nuchal skin‐fold (NF) measurements, in Down syndrome and in normal pregnancies.MethodsNineteen Down syndrome and 224 normal fetuses underwent ultrasound sequential examinations at 11–13 weeks and 14–28 weeks' gestation. NT was measured at the earlier examination and NF at the later one. Both markers were expressed in multiples of the normal gestation‐specific median (MoM). The affected cases had been referred to us for termination of pregnancy; NT had been measured locally and NF was measured at our center prior to the procedure. All unaffected pregnancies were scanned routinely at our center.ResultsThere was no statistically significant correlation between NT and NF, in either the Down syndrome (r = 0.076, P = 0.76) or the unaffected (r = − 0.021, P = 0.76) pregnancies. The median NF value in Down syndrome fetuses was 1.538 MoM, compared with 0.990 in unaffected fetuses (P < 0.0001). Gaussian modeling with parameters from a published meta‐analysis, updated to include the current series, predicted a 91% detection rate of Down syndrome for a 5% false‐positive rate when NF replaced second‐trimester biochemistry in a sequential contingent screening strategy.ConclusionWhile this study cannot exclude a small correlation between NT and NF, and the Down syndrome karyotype was known at the time of the NF scan, the markers can be considered as independent determinants of Down syndrome risk. Modeling suggests that sequential contingent screening incorporating NF is an effective screening strategy, although this needs to be confirmed in a prospective study. Copyright © 2008 ISUOG. Published by John Wiley & Sons, Ltd.
Frontomaxillary facial angle in screening for trisomy 21 at 11 + 0 to 13 + 6 weeks
Authors: Borenstein M. , Persico N. , Kagan K. O. , Gazzoni A. , Nicolaides K. H. 
Published: June 2008

AbstractObjectiveTrisomy 21 is associated with a flat face, which can now be quantified by measurement of the frontomaxillary facial (FMF) angle. The aim of this study was to examine whether in trisomy 21 fetuses fetal nuchal translucency (NT) thickness and maternal serum free ß‐human chorionic gonadotropin (ß‐hCG) and pregnancy‐associated plasma protein‐A (PAPP‐A) are independent of the FMF angle, and to estimate the performance of a first‐trimester screening test for trisomy 21 that includes measurement of the FMF angle.MethodsThis was a prospective study in singleton pregnancies at 11 + 0 to 13 + 6 weeks of gestation in which three‐dimensional volumes of the fetal head were obtained and measurement of the FMF angle performed immediately before fetal karyotyping by chorionic villus sampling (CVS). The women chose to have CVS after risk assessment by a combination of maternal age, fetal NT thickness and maternal serum free ß‐hCG and PAPP‐A. Regression analysis was used to examine the significance of the association within the euploid and within the trisomy 21 fetuses between the deviation from the normal median in FMF angle and the deviation in NT, free ß‐hCG and PAPP‐A. We estimated the detection rate (DR) and false positive rate (FPR) of first‐trimester screening for trisomy 21 by measuring the FMF angle in all cases and of an alternative policy in which first‐stage screening is by fetal NT and maternal serum biochemistry in all patients, followed by second‐stage assessment of FMF angle only in those with an intermediate risk (1 in 51 to 1 in 1000) after the first stage.ResultsThe FMF angle was measured in 782 euploid and 108 trisomy 21 fetuses. In the euploid fetuses the mean FMF angle decreased linearly with CRL from 83.5° at a crown–rump length (CRL) of 45 mm to 76.4° at a CRL of 84 mm. In the euploid fetuses the mean delta FMF angle was 0.0 (SD, 4.264)° and the respective values in the trisomy 21 fetuses were 7.172 (SD, 4.092)°. Incorporating the FMF angle in first‐trimester combined screening increased the estimated DR from 90 to 94% at an FPR of 5% and from 85 to 92% at an FPR of 3%. In two‐stage screening it would be necessary to measure the FMF angle in 12% of cases and the DRs would be 93 and 91% at FPRs of 5 and 3%, respectively.ConclusionsMeasurement of the FMF angle improves the performance of first‐trimester screening for trisomy 21. Copyright © 2008 ISUOG. Published by John Wiley & Sons, Ltd.
Prenatal diagnosis of thrombosis of the dural sinuses: report of six cases, review of the literature and suggested management
Authors: Laurichesse Delmas H. , Winer N. , Gallot D. , Lopes K. , Perrotin F. , Fluncker S. , Geissler F. , Beaufrere A. M. , Vendittelli F. , Couture C. , Lemery D. 
Published: June 2008

AbstractObjectivesTo describe and assess the sonographic findings, evolution and clinical implications of thrombosis of the fetal dural sinuses.MethodsWe compiled a multicenter report of the outcomes of five cases with a prenatal diagnosis of thrombosis of the dural sinuses, and one case in which thrombosis of the dural sinus was diagnosed at necroscopy after termination of pregnancy. Prognostic factors are discussed, and suggestions made for prenatal and postnatal management.ResultsThe mean (range) gestational age at diagnosis of thrombosis of the dural sinuses in the five cases in which it was made prenatally was 25.2 (22–31) weeks. In these five cases, diagnosis was made by sonography and confirmed by magnetic resonance imaging (MRI), which showed a blood clot in the region of the torcular herophili. Three of the six cases delivered vaginally with favorable sonographic findings, and normal clinical neurological development. Two pregnancies were terminated at the request of the parents. In one of these cases the prognosis was poor, with signs of fetal decompensation or cardiac failure; the pregnancy was terminated and necropsy revealed thrombosis of the occipital dural sinuses associated with a hemangioma. One infant, in whom the thrombosis developed in conjunction with a dural sinus malformation, died at 4 months of age.ConclusionsThrombosis of the cerebral venous circulation can occur antenatally and is detectable by fetal real‐time and color Doppler ultrasound examination. A review of the literature supports targeted evaluation of the fetus by serial ultrasound imaging and MRI to help guide the diagnosis, and to improve the counseling and management of such cases. Partial or total regression, isolated abnormality, absence of fetal decompensation or signs of cardiac failure and favorable clinical evolution are suggestive of favorable prognosis. In such cases, non‐interventional neonatal management is recommended. Copyright © 2008 ISUOG. Published by John Wiley & Sons, Ltd.
Spectrophotometric studies of cheuri (Madhuca butyracea) fat and ghee mixtures: I
Authors: Jha J. S. 
Published: June 2008

AbstractVisible spectra of cheuri (Madhuca butyracea) fat, ghee (clarified butter fat) and 10 of their mixtures are reported. Pure ghee showed no absorption band in the visible range whereas the cheuri fat samples showed an absorption band with maxima between 640 and 680 nm. Even 5% cheuri fat content in ghee had a small absorption in this range. An index R (maximal absorbance of band between 640 and 680 nm‐A700) was found suitable for estimating the amount of cheuri fat in ghee samples.
Recent advances in the analysis of glucosinolates
Authors: Olsen O. , Sørensen H. 
Published: June 2008

AbstractOccurrence and biochemistry of glucosinolates are briefly discussed. The chemistry of intact glucosinolates and their degradation products is considered in relation to the methods used for their determination. Different methods have been used, including ion‐ exchange chromatography, paper chromatography, high‐ voltage electrophoresis,1H‐ and13C‐ NMR spectroscopy. The quantitative analysis of trimethylsilylated desulfoglucosinolates by gas chromatography and of intact glucosinolates by high performance liquid chromatography is discussed in relation to previously used methods based on the determination of glucosinolate degradation products.
GOCE gradiometer: estimation of biases and scale factors of all six individual accelerometers by precise orbit determination
Authors: Visser P. N. A. M. 
Published: June 2008

AbstractA method has been implemented and tested for estimating bias and scale factor parameters for all six individual accelerometers that will fly on-board of GOCE and together form the so-called gradiometer. The method is based on inclusion of the individual accelerometer observations in precise orbit determinations, opposed to the baseline method where so-called common-mode accelerometer observations are used. The method was tested using simulated data from a detailed GOCE system simulator. It was found that the observations taken by individual accelerometers need to be corrected for (1) local satellite gravity gradient (SGG), and (2) rotational terms caused by centrifugal and angular accelerations, due to the fact that they are not located in the satellite’s center of mass. For these corrections, use is made of a reference gravity field model. In addition, the rotational terms are derived from on-board star tracker observations. With a perfect a priori gravity field model and with the estimation of not only accelerometer biases but also accelerometer drifts, scale factors can be determined with an accuracy and stability better than 0.01 for two of the three axes of each accelerometer, the exception being the axis pointing along the long axis of the satellite (more or less coinciding with the flight direction) for which the scale factor estimates are unreliable. This axis coincides with the axis of drag-free control, which results in a small variance of the signal to be calibrated and thus an inaccurate determination of its scale factor in the presence of relatively large (colored) accelerometer observation errors. In the presence of gravity field model errors, it was found that still an accuracy and stability of about 0.015 can be obtained for the accelerometer scale factors by simultaneously estimating empirical accelerations.
How to Optimize Autonomic Nerve Preservation in Total Mesorectal Excision: Clinical Topography and Morphology of Pelvic Nerves and Fasciae
Authors: Clausen Nicolas , Wolloscheck Tanja , Konerding Moritz A. 
Published: June 2008

AbstractBackgroundUrogenital dysfunction after rectal and pelvic surgery was significantly decreased with the introduction of nerve‐preserving dissection and total mesorectal excision (TME). Profound topographic knowledge of the pelvic connective tissue spaces is indispensable for identification and preservation of autonomic pelvic nerves. The purpose of this cadaver study was to highlight the course of important autonomous nerve structures and to identify potential injury sites.MethodsEleven cadavers were dissected according to TME with subsequent preparation of the pelvic nerves. The pelves of further three cadavers were sliced horizontally and cubed. Specimens were harvested and processed for light microscopy and immunohistochemistry to analyze both fascia and the types of nerves and their localization.ResultsThe neurovascular bundle, arising from the inferior pelvic plexus, shows the highest nerve density. At the lateral edge of Denonvilliers’ fascia, it pierces the parietal pelvic fascia. Several fine nerve branches spread into the loose periprostatic tissue up to the prostate or pass the prostate toward the urinary bladder. En route, we consistently find perikarya of autonomic nerves. Within the mesorectum, nerve fibers are distributed heterogeneously with laterally high densities, ventrally and dorsally low densities.ConclusionThe highest risk for pelvic nerve damage—apart from lesions of the superior hypogastric plexus itself—is anterolaterally of the rectum where the neurovascular bundle releases from the pelvic sidewall. Careful dissection helps to identify and protect these nerve structures. The retroprostatic Denonvilliers’ fascia contains no important nerve structures.
Resection of Colorectal Liver Metastases: Is a Resection Margin of 3 mm Enough?
Authors: Konopke Ralf , Kersting Stephan , Makowiec Frank , Gaßmann Peter , Kuhlisch Eberhard , Senninger Norbert , Hopt Ulrich , Saeger Hans Detlev 
Published: June 2008

AbstractBackgroundA safety margin of ≥10 mm is generally accepted in surgery for colorectal metastases. It is reasonable that modern methods of liver parenchyma dissection may allow for a reduction in this distance.MethodsA total of 333 patients were included in a multicenter trial after resection of colorectal liver metastases. Dissection of the liver had been performed with a CUSA®, UltraCision®, or water‐jet dissector. The size of the resection margin was correlated with recurrence risk and survival.ResultsThe median hepatic recurrence‐free survival reached 35 months for all patients; median recurrence‐free survival was 24 months and overall survival was 41 months. Univariate analysis of different groups denoting the extent of resection margin (≥10 mm, 6–9 mm, 3–5 mm, 1–2 mm, 0 mm (R1)) indicated that a margin of 1–2 mm leads to a significantly reduced median hepatic recurrence‐free survival of 20 months (p = 0.004) and recurrence‐free survival of 19 months (p = 0.011). Patients with R1 resection had the worst prognosis. Overall survival was not influenced by the size of the resection margin. Surgical margins were significantly reduced in simultaneous resections of four or more liver metastases and in cases in which metastatic infiltration of central liver segments was present. At multivariate analysis, resection margins of 1–2 mm and 0 mm were independent predictors of hepatic recurrence and overall recurrence.ConclusionThe indication for resection of metastases can be safely extended to cases in which tumors sit closer than 1 cm to nonresectable structures.
Selection of modalities, prescription, and technical issues in children on peritoneal dialysis
Authors: Verrina Enrico , Cappelli Valeria , Perfumo Francesco 
Published: June 2008

AbstractPeritoneal dialysis (PD) is widely employed as a dialytic therapy for uraemic children, especially in its automated form (APD), that is associated with less burden of care on patient and family than continuous ambulatory PD. Since APD offers a wide range of treatment options, based on intermittent and continuous regimens, prescription can be individualized according to patient’s age, body size, residual renal function, nutritional intake, and growth-related metabolic needs. Transport capacity of the peritoneal membrane of each individual patient should be assessed, and regularly monitored, by means of standardized peritoneal function tests validated in pediatric patients. To ensure maximum recruitment of peritoneal exchange area, fill volume should be scaled to body surface area and adapted to each patient, according to clinical tolerance and intraperitoneal pressure. PD solutions should be employed according to their biocompatibility and potential ultrafiltration capacity; new pH-neutral, glucose-free solutions can be used in an integrated way in separate dwells, or by appropriately mixing during the same dialytic session. Kinetic modelling software programs may help in the tailoring of PD prescription to individual patients’ characteristics and needs. Owing to advances in the technology of new APD machines, greater programming flexibility, memorized delivery control, and tele-dialysis are currently possible.