bluuebunny/crossref_metadata_2025 huggingface dataset:
Identification of a Novel Bovine Herpesvirus 1 Transcript Containing a Small Open Reading Frame That Is Expressed in Trigeminal Ganglia of Latently Infected Cattle
Authors: Inman Melissa , Zhou Joe , Webb Heather , Jones Clinton
Published: April 2004

Bovine herpesvirus 1
(BHV-1), like other
Alphaherpesvirinae
subfamily members, establishes latency in sensory neurons. The latency-related (LR) RNA is abundantly expressed during latency, and expression of an LR protein is required for the latency reactivation cycle in cattle. Within LR promoter sequences, a 135-amino-acid open reading frame (ORF) was identified, ORF-E, that is antisense to the LR RNA. ORF-E is also downstream of the gene encoding the major viral transcriptional activator, bICP0. Strand-specific reverse transcription-PCR demonstrated that a transcript containing ORF-E was consistently expressed in trigeminal ganglia (TG) of latently infected calves, productively infected cultured cells, and acutely infected calves. As expected, a late transcript encoding glycoprotein C was not detected in TG of latently infected calves. The ORF-E transcript is polyadenylated and is expressed early when cultured bovine cells are productively infected. Protein coding sequences containing ORF-E were fused to green fluorescent protein (GFP) to examine the cellular localization of the putative protein. In transiently transfected mouse neuroblastoma (neuro-2A) and human neuroblastoma (SK-N-SH) cells, the ORF-E/GFP fusion protein was detected in discreet domains within the nucleus. In contrast, the ORF-E/GFP fusion protein was detected in the cytoplasm and nucleus of rabbit skin cells and bovine kidney cells. As expected, the GFP protein was expressed in the cytoplasm and nucleus of transfected cells. These studies indicate that the ORF-E transcript is consistently expressed during latency. We suggest that the ORF-E gene regulates some aspect of the latency reactivation cycle.
Are Online Study Questions Beneficial?
Authors: Grimstad Kristin , Grabe Mark
Published: April 2004

Brothen and Wambach (2001) found that under certain conditions students do not benefit from online resources. They awarded points toward the course grade for high performance on small sets of practice questions and concluded student strategies in completing these quizzes were not beneficial to course performance. We investigated student use of online questions when students received no credit for answering practice questions and found students who made voluntary use of online questions scored higher on course examinations. In contrast to situations in which students complete assigned tasks for credit, students who respond to questions as a voluntary study tactic may use question feedback quite differently and make decisions about how many questions to review using different criteria.
Contribution of Head Shadow and Pinna Cues to Chronic Monaural Sound Localization
Authors: Van Wanrooij Marc M. , Van Opstal A. John
Published: April 2004

Monaurally deaf people lack the binaural acoustic difference cues in sound level and timing that are needed to encode sound location in the horizontal plane (azimuth). It has been proposed that these people therefore rely on spectral pinna cues of their normal ear to localize sounds. However, the acoustic head-shadow effect (HSE) might also serve as an azimuth cue, despite its ambiguity when absolute sound levels are unknown. Here, we assess the contribution of either cue in the monaural deaf to two-dimensional (2D) sound localization. In a localization test with randomly interleaved sound levels, we show that all monaurally deaf listeners relied heavily on the HSE, whereas binaural control listeners ignore this cue. However, some monaural listeners responded partly to actual sound-source azimuth, regardless of sound level. We show that these listeners extracted azimuth information from their pinna cues. The better monaural listeners were able to localize azimuth on the basis of spectral cues, the better their ability to also localize sound-source elevation. In a subsequent localization experiment with one fixed sound level, monaural listeners rapidly adopted a strategy on the basis of the HSE. We conclude that monaural spectral cues are not sufficient for adequate 2D sound localization under unfamiliar acoustic conditions. Thus, monaural listeners strongly rely on the ambiguous HSE, which may help them to cope with familiar acoustic environments.
Roles of Ca2+, Hyperpolarization and Cyclic Nucleotide-Activated Channel Activation, and Actin in Temporal Synaptic Tagging
Authors: Zhong Ning , Zucker Robert S.
Published: April 2004

At crayfish neuromuscular junctions, cAMP increases transmitter released by action potentials by activating two effectors, hyperpolarization and cyclic nucleotide-activated channels (HCNCs) and a separate target that has been tentatively identified as exchange protein activated by cAMP (Epac). Intense electrical activity in the motor neuron induces a long-term facilitation (LTF) of transmitter release in which hyperpolarization from an electrogenic Na+-K+exchanger activates HCNCs. The coupling of HCNCs to transmission involves actin. After LTF induction, cAMP further increases transmission in an HCNC-independent manner, activating the second target. This relaxation of the requirement for HCNC activation to enhance release is called temporal synaptic tagging. Tagging lasts at least 1 d but develops only in the 10 min period after electrical activity. The HCNCs are activated by the post-tetanic hyperpolarization occurring during this time. Both synaptic tagging and LTF induction depend on presynaptic Ca2+accumulation during activity; both are blocked by EGTA-AM, and LTF is also prevented by stimulation in a low-[Ca2+] medium. Actin depolymerizers prevent induction of LTF and tagging, with little effect on HCNCs, whose sensitivity to cAMP and HCNC blockers is unaffected by tagging. Enhancement of actin polymerization can rescue tagging from HCNC block, suggesting that actin acts at a step after HCNC activation. These and other recent results suggest a model in which HCNC activation, followed by a process involving actin polymerization, acts cooperatively with [Ca2+] to induce tagging, after which only Epac activation is required for cAMP to further enhance transmission.
The Role of the Frontal Pursuit Area in Learning in Smooth Pursuit Eye Movements
Authors: Chou I-han , Lisberger Stephen G.
Published: April 2004

The frontal pursuit area (FPA) in the cerebral cortex is part of the circuit for smooth pursuit eye movements. The present paper asks whether the FPA is upstream, downstream, or at the site of learning in pursuit eye movements. Learning was induced by having monkeys repeatedly pursue targets that moved at one speed for 150 msec before changing speed. Single-cell recording showed no consistent correlate of pursuit learning in the responses of FPA neurons. Some neurons showed changes in firing in the same direction as the learning, others showed changes in the opposite direction, and many showed no changes at all. In contrast, the eye movements evoked by electrical stimulation of the FPA showed clear correlates of learning. Learning effects were observed when microstimulation was delivered during the initiation of pursuit and during fixation of a stationary target. In addition, learning caused changes in the degree to which stimulation of the FPA enhanced the eye velocity evoked by brief perturbations of a stationary target. The magnitude of the change in the stimulation-evoked eye movement in each tracking condition was proportional to the size of the eye movement evoked under that condition before learning. We conclude that learning occurs downstream from the FPA, possibly within the cerebellum, and that learning may be related to mechanisms that also control the gain of visual-motor responses on a rapid time scale.
A Novel Class of Neurons at the Trigeminal Subnucleus Interpolaris/Caudalis Transition Region Monitors Ocular Surface Fluid Status and Modulates Tear Production
Authors: Hirata Harumitsu , Okamoto Keiichiro , Tashiro Akimasa , Bereiter David A.
Published: April 2004

Reflex tears are produced by many conditions, one of which is drying of the ocular surface. Although peripheral neural control of the lacrimal gland is well established, the afferent pathways and properties of central premotor neurons necessary for this reflex are not known. Male rats under barbiturate anesthesia were used to determine whether neurons at the ventral trigeminal subnucleus interpolaris- caudalis (Vi/Vc) transition or the trigeminal subnucleus caudalis-cervical cord (Vc/C1) junction region in the lower brainstem were necessary for tears evoked by noxious chemical stimulation (CO2pulses) or drying of the ocular surface. Both the Vi/Vc transition and Vc/C1 junction regions receive a dense direct projection from corneal nociceptors. Synaptic blockade of the Vi/Vc transition, but not the Vc/C1 junction, by the GABAAreceptor agonist muscimol inhibited CO2-evoked tears. Glutamate excitation of the Vi/Vc transition, but not the Vc/C1 junction, increased tear volume. Single units recorded at the Vi/Vc transition, but not at the Vc/C1 junction, were inhibited by wetting and excited by drying the ocular surface. Nearly all moisture-sensitive Vi/Vc units displayed an initial inhibitory phase to noxious concentrations of CO2followed by delayed excitation and displayed an inhibitory surround receptive field from periorbital facial skin. Drying of the ocular surface produced many Fos-positive neurons at the Vi/Vc transition, but not at the Vc/C1 junction. This is the first report of a unique class of moisture-sensitive neurons that exist only at the ventral Vi/Vc transition, and not at more caudal portions of Vc, that may underlie fluid homeostasis of the ocular surface.
Neuroendocrine Control of Larval Ecdysis Behavior inDrosophila: Complex Regulation by Partially Redundant Neuropeptides
Authors: Clark Anthony C. , del Campo Marta L. , Ewer John
Published: April 2004

To complete each molting cycle, insects display a stereotyped sequence of behaviors to shed the remains of the old cuticle. These behavioral routines, as well as other related physiological events, are critical for proper development and are under the control of several neuropeptides. Their correct deployment and concatenation depends on the complex actions and interactions among several peptide hormones: ecdysis triggering hormone (ETH), eclosion hormone (EH), and crustacean cardioactive peptide (CCAP). Numerous theories, some in conflict, have been proposed to define the functional hierarchies by which these regulatory factors operate. Here we use wild-typeDrosophilaand transgenic flies bearing targeted ablations of either EH or CCAP neurons, or ablations of both together, to reevaluate their roles. Consistent with findings in moths, our results suggest that EH and ETH affect the release of each other via a positive feedback, although ETH can also be released in the absence of EH. We show that EH and ETH both contribute to the air filling of the air ducts (trachea) of the next stage but that EH may play a primary role in this process. We present evidence that EH, whose actions have always been placed upstream of CCAP, may also regulate ecdysis independently of CCAP. Finally, we confirm that flies lacking EH neurons do not ecdyse prematurely when injected with ETH peptides. These findings are surprising and not easily explained by currently available hypotheses. We propose that important additional neuropeptides, and additional interactions between known regulators, contribute to the mechanisms underlying insect ecdysis behaviors.
Novel Crosslinking of High‐order and Multiple Copper Twins in Advanced Microelectronics Packaging
Authors: Zhang W. , Liu C.‐Z. , Li D.‐X. , Sui M.‐L.
Published: April 2004

Novel crosslinking of high‐order and multiple copper twins has been formed in the metallization/solder interconnect subjected to the thermal aging. This surprising finding may illustrate a universal metallization failure mode. Meanwhile, many copper nanocrystals in situ originated from those twins crosslinking shed a novel light on the synthesis approach to fascinating nanocrystalline metals.
Polymer Nanocomposites for Aerospace Applications: Characterization
Authors: Njuguna J. , Pielichowski K.
Published: April 2004

Development of several advanced miscroscopic and sprectroscopic techniques have played a key role in the development of characterization and parametric studies of polymer nanocomposites starting from the molecular level. The main issues affecting the production of good quality composites are fiber alignment, fiber‐matrix adhesion and fiber dispersion which makes characterization so vital. The current work reviews the ongoing investigations and techniques to overcome the challenges posed by polymer nanocomposites characterization.
Taking Snapshots of Photoexcited Molecules in Disordered Media by Using Pulsed Synchrotron X‐rays
Authors: Chen Lin X.
Published: April 2004

Photoexcited molecules are quintessential reactants in photochemistry. Structures of these photoexcited molecules in disordered media in which a majority of photochemical reactions take place remained elusive for decades owing to a lack of suitable X‐ray sources, despite their importance in understanding fundamental aspects in photochemistry. As new pulsed X‐ray sources become available, short‐lived excited‐state molecular structures in disordered media can now be captured by using laser‐pulse pump, X‐ray pulse–probe techniques of third‐generation synchrotron sources with time resolutions of 30–100 ps, as demonstrated by examples in this review. These studies provide unprecedented information on structural origins of molecular properties in the excited states. By using other ultrafast X‐ray facilities that will be completed in the near future, time‐resolution for the excited‐state structure measurements should reach the femtosecond timescales, which will make “molecular movies” of bond breaking or formation, and vibrational relaxation, a reality.
Acrylic acid/vinyl acetate suspension copolymerizations. I. Partition coefficients for acrylic acid
Authors: Silva Fabricio Machado , Lima Enrique Luis , Pinto José Carlos
Published: April 2004

During acrylic acid (AA)/vinyl acetate (VAc) suspension copolymerizations, AA is partitioned between the organic phase and the aqueous phase. For this reason, the AA partition coefficient in suspensions of AA/VAc/water is studied here. Partition experiments were performed at different temperatures and AA concentrations. It was observed that the AA partition coefficient ranged from 0.001 to 1.58, depending strongly on the temperature and on the aqueous phase composition. Therefore, the distribution of AA between the continuous phase and the monomer droplets may exert a significant effect upon the observed kinetic behavior during suspension polymerizations. The UNIFAC‐LLE model was used to describe the observed liquid–liquid equilibrium of the ternary system AA/VAc/water and model predictions were compared to the obtained experimental data. It was observed that the UNIFAC‐LLE model is able to represent AA partition coefficients qualitatively only when AA dissociation effects are taken into consideration. Additional experiments also indicated that AA partition coefficients may be very sensitive to the presence of polymer in the organic phase and to the presence of salt in the aqueous phase, as usual during actual suspension copolymerizations. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 93: 1077–1088, 2004
Assessing organo‐clay dispersion in polymer nanocomposites
Authors: Eckel Deborah F. , Balogh Michael P. , Fasulo Paula D. , Rodgers William R.
Published: April 2004

Organo‐clay polymer nanocomposites offer improved material properties at very low filler loadings making them of immediate interest for application in body panels, claddings, and instrument panels. This improvement in properties requires that the organo‐clay be well dispersed if not completely exfoliated. Conventionally, the dispersion and exfoliation of the organo‐clay is evaluated using transmission electron microscopy (TEM) and X‐ray diffraction (XRD). Although both TEM and XRD data were found to correlate with flexural modulus of thermoplastic olefin nanocomposite materials, only TEM proved successful in quantifying the dispersion of the organo‐clay in all nanocomposite materials (exfoliated, tactoid, or agglomerated tactoid). XRD was found to be capable of detecting exfoliation and intercalation but is limited because of clay dilution, preferred orientation, mixed‐layering, and other peak broadening factors. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 93: 1110–1117, 2004
Automatic generation of domain representations using thesaurus structures
Authors: Lloréns Juan , Velasco Manuel , de Amescua Antonio , Moreiro José A. , Martínez Vicente
Published: April 2004

Domain analysis was first used 15 years ago as one of the most important techniques for software reuse. Even today, new techniques appear every year, and different authors propose different domain representation structures to represent and store all the different software components and the relationships among them. These relationships among components are the kernel of the domain semantics. In this report, a set of techniques and tools is presented regarding mathematical, statistical, and neural fields that, when linked together, enable semi‐automatically building domain representations and storing them in a thesaurus structure of software components. Thesaurus structures, widely used in information science, are presented as the domain‐modeling key concept, due to their higher automation possibilities compared with previous structures. New metrics to evaluate the quality, consistency, and completeness of the domain model obtained through this technique are also presented.
Dynamic Chemical Devices: Modulation of Photophysical Properties by Reversible, Ion‐Triggered, and Proton‐Fuelled Nanomechanical Shape‐Flipping Molecular Motions
Authors: Barboiu Mihail , Prodi Luca , Montalti Marco , Zaccheroni Nelsi , Kyritsakas Nathalie , Lehn Jean‐Marie
Published: April 2004

The terpy‐derived (terpy=terpyridine) ligand 1 has an extended W shape in which the two appended photoactive pyrenyl groups are held apart. On binding of a zinc(II) ion with a terpy group, ligand 1 is converted into complex 2 whereby it adopts a U shape, thus stacking the aromatic units. This structural modification leads to a very pronounced change in photophysical properties: from a highly fluorescent free ligand to a very weakly emitting complex. The W/U structural switching can be reversibly induced by the addition of a competitive tren ligand, which binds and releases a zinc(II) ion under protonation/deprotonation cycles, thus leading to oscillations in light emission. Therefore, the present system performs periodic modulation of optical output through a nanomechanical shape‐flipping motion, triggered by metal ion binding and fuelled by acid–base neutralisation energy. Overall, it represents an ion‐triggered opto‐mechanical supramolecular device.
Highly Efficient Biocatalytic Resolution of cis‐ and trans‐3‐Aminoindan‐1‐ol: Syntheses of Enantiopure Orthogonally Protected cis‐ and trans‐Indane‐1,3‐diamine
Authors: López‐García Mónica , Alfonso Ignacio , Gotor Vicente
Published: April 2004

The efficient chemoenzymatic synthesis of enantiopure 1,3‐difunctionalized indane derivatives has been achieved. The corresponding cis and trans N‐protected amino alcohols were successfully resolved by acetylation using lipase B, which is a biocatalyst isolated from Candida antarctica. All the possible isomers were obtained in very good chemical yields and ee values (>99 %). The utility of these compounds was subsequently shown by the preparation of orthogonally protected cis‐ and trans‐indane‐1,3‐diamine using a Mitsunobu reaction. Both enantiomers of the trans isomer and a desymmetrized cis diastereomer were prepared in enantiopure form. Complete inversion of configuration during the Mitsunobu reaction was demonstrated by a combination of NMR techniques and molecular modeling. The utility and versatility of the strategy was also demonstrated by the selective deprotection of each nitrogen atom under mild reaction conditions.
Mikroreaktionstechnik im Curriculum der Technischen Chemie an der FSU Jena – Stand und Perspektive
Authors: Gorges R. , Klemm W. , Kreisel G. , Ondruschka B. , Scholz P. , Taubert T.
Published: April 2004

No abstracts.
Die Industrieplattform Mikroverfahrenstechnik – Eine deutsche Initiative zur Förderung der Mikrotechnik in Chemie, Pharma und Life Sciences
Authors: Bazzanella A.
Published: April 2004

No abstracts.
Phase II study of oral S‐1 for treatment of metastatic colorectal carcinoma
Authors: Shirao Kuniaki , Ohtsu Atsushi , Takada Hideho , Mitachi Yasushi , Hirakawa Kosei , Horikoshi Noboru , Okamura Takeshi , Hirata Koichi , Saitoh Soh , Isomoto Hiroharu , Satoh Atsushi
Published: April 2004

BACKGROUND

The goal of the current study was to evaluate the objective response rate and toxicity associated with the oral fluoropyrimidine S‐1 (a combination of tegafur, 5‐chloro‐2,4‐dihydroxypyridine, and potassium oxonate) in patients with previously untreated metastatic colorectal carcinoma.

METHODS

Thirty‐eight patients were enrolled in the study. S‐1 was administered orally at a dose of 40 mg/m2 twice daily for 28 days, followed by a 14‐day rest period. Treatment was repeated every 6 weeks unless disease progression was observed.

RESULTS

A combined total of 173 courses of S‐1 were administered to the 38 enrolled patients. The median number of courses administered to a given patient was 3.5 (range, 1–18). Although no patient exhibited a complete response to treatment, 15 had partial responses (response rate, 39.5%; 95% confidence interval, 24.0–56.6%). In addition, 5 patients had minor responses, and 14 had stable disease. Four patients were found to have progressive disease after two courses of treatment. The median survival time was 358 days (95% confidence interval, 305–490 days), and the 1‐year survival rate was 47.4%. The most common adverse reactions included myelosuppression and gastrointestinal toxicity; most cases involved Grade 1 or 2 toxicity, but Grade 3 toxicities (anemia [7.9% of patients], neutropenia [5.3% of patients], diarrhea [2.6% of patients], and abnormal bilirubin levels [7.9% of patients]) also were noted. Neither Grade 4 toxicity nor treatment‐related death was observed during the study.

CONCLUSIONS

Orally administered S‐1 is active against metastatic colorectal carcinoma and has an acceptable toxicity profile. This promising agent has the potential to become a valuable chemotherapeutic option. Cancer 2004. © 2004 American Cancer Society.
Does pT2b prostate carcinoma exist? Critical appraisal of the 2002 TNM classification of prostate carcinoma
Authors: Eichelberger Lori E. , Cheng Liang
Published: April 2004

BACKGROUND

Clinicopathologic staging of prostate adenocarcinoma provides a method for assessing the extent of tumor and predicting patient prognosis. The American Joint Committee on Cancer (AJCC) TNM staging system has undergone recent revisions for T2 prostate tumors. T2 tumors currently are subclassified as T2a (less than one‐half of one lobe involvement), T2b (greater than one‐half of one lobe involvement), and T2c (bilateral involvement). Despite general acceptance of the system, controversy and uncertainty still exist with regard to the application of the TNM staging system, particularly the use of the T2 staging subclassification.

METHODS

The study population was comprised of 369 patients with prostate carcinoma who were treated with radical retropubic prostatectomy. Radical prostatectomy specimens were evaluated histologically by complete embedding and whole‐mount processing. Tumor specimens were staged initially using the 1998 AJCC TNM system and then reevaluated according to the 2002 TNM staging guidelines.

RESULTS

The weights of the prostate specimens ranged from 14–149 g (median, 38 g). Prostate tumor specimens were multifocal in 312 patients (85%). The majority of the specimens were classified pathologically as T2 (n = 276 [75%]). Using the 2002 TNM staging criteria, 54 of the tumor specimens (15%) were classified as pT2a, 222 (60%) were pT2c, 75 (20%) were pT3a, and 18 (5%) were pT3b. No pathologic T2b tumor specimens were identified.

CONCLUSIONS

Taking into consideration the average weight of the prostate specimens (38 g), as well as the predominance of tumor multifocality, it would be unusual to identify tumors involving greater than one‐half of 1 lobe (approximately an 8‐cm3 tumor) without involving the other lobe. The authors question the existence of a true pT2b tumor. Cancer 2004. © 2004 American Cancer Society.
Sonographic assessment of clubfoot
Authors: Gigante Cosimo , Talenti E. , Turra S.
Published: April 2004

Purpose

This study was performed to develop a standardized methodology for the sonographic assessment of clubfoot at birth and at the end of both conservative treatment and surgical correction.

Methods

Forty‐two congenital clubfeet and 42 normal feet were examined sonographically in the position of spontaneous alignment and during passive manual correction. Scans along 4 planes provided information relevant to the assessment: sagittal posterior, sagittal anterior, coronal lateral, and transverse.

Results

Sagittal posterior sonograms demonstrated the progressive gain of dorsiflexion ability during the different steps of treatment for clubfoot. Sagittal anterior sonograms could not demonstrate the normal alignment of the navicular in clubfeet because of the bone's medial displacement. On transverse sonograms, the talar head and the medially displaced navicular may lie on the same plane, depending on the severity of the deformity. Coronal lateral sonograms provided for estimation of the relationships between the calcaneus and cuboid, which were described by the calcaneal‐cuboid angle.

Conclusions

Sonography is a promising technique for assessment and monitoring of clubfoot during treatment. The method described here yields accurate and reproducible information about the anatomy of the nonossified clubfoot, helping the orthopedic team decide on appropriate treatment steps. © 2004 Wiley Periodicals, Inc. J Clin Ultrasound 32:235–242, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI: 10.1002/jcu.20022
B‐flow imaging of internal carotid artery stenosis: Comparison with power Doppler imaging and digital subtraction angiography
Authors: Yurdakul Mehmet , Tola Muharrem , Cumhur Turhan
Published: April 2004

Purpose

Digital subtraction angiography (DSA) is the gold standard in the diagnosis of carotid artery stenosis, but it has a relatively high complication rate. We evaluated the efficacy of B‐flow imaging (BFI) in examining internal carotid artery stenosis (ICAS) compared with power Doppler imaging (PDI) and DSA.

Methods

We performed BFI, PDI, and DSA on 56 consecutive patients with suspected ICAS. The degree of stenosis was calculated for each technique, and results of BFI and PDI were then correlated with those of DSA.

Results

Measurements of the percentage of stenosis made using both sonographic techniques were significantly correlated with those of DSA (p < 0.0001). However, the coefficient of correlation between DSA and BFI (r = 0.94) was higher than that between DSA and PDI (r = 0.87). The mean difference between ICAS measurements with BFI and DSA was −1.3% (95% confidence interval [CI], –2.5 to 0). The mean difference between ICAS measurements with PDI and DSA was −6.5% (95% CI, –8.2 to –4.7). ICAS was graded significantly lower on PDI than on DSA, whereas BFI findings were similar to those of DSA.

Conclusion

BFI shows high correlation with DSA and provides a more accurate planimetric evaluation of ICAS than PDI does. © 2004 Wiley Periodicals, Inc. J. Clin Ultrasound 32:243–248, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI: 10.1002/jcu.20024
Comparison of transperineal and transvaginal sonography in predicting preterm delivery
Authors: Yazici Gurkan , Yildiz Akgun , Tiras M. Bulent , Arslan Murat , Kanik Arzu , Oz Utku
Published: April 2004

Purpose

A major advantage of transperineal sonography (TPUS) is its ability to evaluate the cervix without causing any distortion. This study was performed to compare transvaginal sonography (TVUS) and TPUS at 24 weeks of gestation in predicting preterm delivery in low‐risk pregnancy.

Methods

Three hundred fifty‐seven pregnant women underwent TVUS and TPUS at 24 weeks of gestation. The relationship between cervical length and preterm delivery was assessed. Accuracy values of TVUS and TPUS at 24 weeks of gestation were compared in predicting preterm delivery.

Results

Preterm delivery (before 36 weeks of gestation) occurred in 22 pregnancies (6.2%). Mean cervical lengths measured by TVUS and TPUS were significantly different in preterm and term delivery groups (P < 0.05). Areas under the curves were 0.801 and 0.857 for the transvaginal and transperineal measurements, respectively. The coefficient of correlation between the transvaginal and transperineal cervical length measurements was 0.83. TPUS had a sensitivity of 77% in predicting preterm delivery, with a false‐positive rate of 17% and a relative risk of 4.5 at the 32.5‐mm cutoff value.

Conclusions

When the cervix is well visualized, TPUS can predict preterm delivery as accurately as TVUS. © 2004 Wiley Periodicals, Inc. J Clin Ultrasound 32:225–230, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI: 10.1002/jcu. 20027
Nitrate content in lettuce (Lactuca sativa L) heads in relation to plant spacing, nitrogen form and irrigation level
Authors: Abu‐Rayyan Azmi , Kharawish Basel H , Al‐Ismail Khalid
Published: April 2004

A field study was conducted at two locations (Jordan valley and Al‐Jubeiha) with different rainfall levels, altitudes and temperature ranges. The study was established to evaluate the optimum planting density, nitrogen (N) form and irrigation level to attain the best quality of lettuce crop in terms of minimum nitrate (NO3) content and to minimise the impact on the environment. Seeds of ‘Amar’ lettuce were sown 1 month before transplanting. Three forms of N fertiliser (Ca(NO3)2, (NH4)2SO4 and CO(NH2)2) were applied at three times at a total rate of 100 kg N ha−1. Three in‐row spacings (15, 20 and 25 cm) were assigned. Two irrigation levels were applied: level 1 had twice the amount of irrigation water as level 2, which was achieved by doubling the number of irrigation lines. The results indicated that N form significantly increased both N and NO3 contents. Ca(NO3)2 was the most effective in increasing the N and NO3 contents in lettuce leaf tissues, followed by CO(NH2)2 and then (NH4)2SO4. The outer leaves (green colour) had about five times the NO3 content of the inner leaves (pale yellow colour). However, the effect of N form on production, total N absorption and N recovery was significant in the following order: (NH4)2SO4 > Ca(NO3)2 > CO(NH2)2. Increasing the plant spacing resulted in a significant increase in N and NO3 contents in the lettuce leaves. Copyright © 2004 Society of Chemical Industry
Physical scoring function based on AMBER force field and Poisson–Boltzmann implicit solvent for protein structure prediction
Authors: Hsieh Meng‐Juei , Luo Ray
Published: April 2004

A well‐behaved physics‐based all‐atom scoring function for protein structure prediction is analyzed with several widely used all‐atom decoy sets. The scoring function, termed AMBER/Poisson–Boltzmann (PB), is based on a refined AMBER force field for intramolecular interactions and an efficient PB model for solvation interactions. Testing on the chosen decoy sets shows that the scoring function, which is designed to consider detailed chemical environments, is able to consistently discriminate all 62 native crystal structures after considering the heteroatom groups, disulfide bonds, and crystal packing effects that are not included in the decoy structures. When NMR structures are considered in the testing, the scoring function is able to discriminate 8 out of 10 targets. In the more challenging test of selecting near‐native structures, the scoring function also performs very well: for the majority of the targets studied, the scoring function is able to select decoys that are close to the corresponding native structures as evaluated by ranking numbers and backbone Cα root mean square deviations. Various important components of the scoring function are also studied to understand their discriminative contributions toward the rankings of native and near‐native structures. It is found that neither the nonpolar solvation energy as modeled by the surface area model nor a higher protein dielectric constant improves its discriminative power. The terms remaining to be improved are related to 1‐4 interactions. The most troublesome term is found to be the large and highly fluctuating 1‐4 electrostatics term, not the dihedral‐angle term. These data support ongoing efforts in the community to develop protein structure prediction methods with physics‐based potentials that are competitive with knowledge‐based potentials. Proteins 2004. © 2004 Wiley‐Liss, Inc.
Identifying acetylated lignin units in non‐wood fibers using pyrolysis‐gas chromatography/mass spectrometry
Authors: del Río José C. , Gutiérrez Ana , Martínez Ángel T.
Published: April 2004

A series of non‐wood plant fibers, namely kenaf, jute, sisal and abaca, have been analyzed upon pyrolysis‐gas chromatography/mass spectrometry (Py‐GC/MS) of the whole material. The pyrolysis products mainly arise from the carbohydrate and lignin moieties of the fibers. The lignin‐derived phenols belonged to the p‐hydroxyphenylpropanoid (H), guaiacylpropanoid (G) and syringylpropanoid (S) structures, and showed a high S/G ratio of between 2.0 and 5.4, the highest corresponding to kenaf. Among the lignin‐derived phenols released, small amounts of sinapyl and coniferyl acetates (in both cis‐ and trans‐forms) were identified for the first time upon Py‐GC/MS of lignocellulosic materials. Acetylation of the sinapyl and coniferyl alcohols was at the γ‐position of the side chain. The release of these alcohols derived from intact acetylated lignin units upon pyrolysis seems to indicate that the native lignin in the fibers selected for this study is at least partially acetylated. Sinapyl (and coniferyl) acetates have recently been suggested to be authentic lignin precursors involved in the polymerization of lignin along with the normal sinapyl and coniferyl alcohols. Py‐GC/MS will offer a convenient and rapid tool for analyzing naturally acetylated lignins, as well as to screen plant materials for the presence of acetylated units in lignin. Copyright © 2004 John Wiley & Sons, Ltd.
Electrospray sample deposition for matrix‐assisted laser desorption/ionization (MALDI) and atmospheric pressure MALDI mass spectrometry with attomole detection limits
Authors: Wei Hui , Nolkrantz Kerstin , Powell David H. , Woods James H. , Ko Mei‐Chuan , Kennedy Robert T.
Published: April 2004

Electrospray sample deposition was explored for matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry (MALDI‐TOFMS). In this method, nanoliter volumes of matrix/analyte mixture were electrosprayed from a high voltage biased (1–2 kV) fused‐silica capillary onto a grounded MALDI plate mounted 100–500 μm from the capillary outlet. Electrospray deposition with these conditions produced sample spots 200–300 μm in diameter thus matching the laser spot size. Varying spray voltage and distance resulted in different crystal sizes and volatilization rates for α‐cyano‐4‐hydroxycinnamic acid matrix. Best results were obtained when the sample was deposited as wet droplets as opposed to deposition as dried solid. Under ‘wet‐spray’ conditions, 2–4 μm diameter crystals were formed and detection limits for several neuropeptides were 0.7–25 amol. Samples could be pre‐concentrated on the plate by spraying continuously and allowing sample to evaporate in a small spot. Sample volumes as large as 580 nL were deposited yielding a detection limit of 35 pM for neurotensin 1‐11. Electrospray sample deposition yielded similar results when using atmospheric pressure‐MALDI coupled with a quadrupole ion trap mass spectrometer, except that the sensitivity was ∼seven‐fold worse. Copyright © 2004 John Wiley & Sons, Ltd.
Study of the photoinduced degradation of polycyclic musk compounds by solid‐phase microextraction and gas chromatography/mass spectrometry
Authors: Sanchez‐Prado Lucía , Lourido Mercedes , Lores Marta , Llompart Maria , Garcia‐Jares Carmen , Cela Rafael
Published: April 2004

Polycyclic musks are widely used synthetic fragrances that have been identified during the last few years in biota samples and environmental matrices. Nevertheless, there is a lack of information concerning the photodegradation behavior of these compounds. In this work, the photoinduced degradation of six polycyclic musk compounds (Cashmeran, Celestolide, Phantolide, Galaxolide, Traseolide and Tonalide) was studied using a solid‐phase microextraction (SPME) fiber as support. Musk fragrances were extracted from aqueous solutions using SPME fibers that were subsequently exposed to ultraviolet (UV) irradiation for different times. To study the degradation kinetics and to tentatively identify the photoproducts generated, gas chromatography coupled to ion trap mass spectrometry was used. Aqueous photodegradation studies were also performed. The on‐fiber photodegradation approach avoids the need for further extraction processes and makes the identification of photoproducts easier, due to their higher concentration on the fibers. All musk compounds were easily photodegraded, suggesting that UV irradiation could work as a decontamination tool for these musks. Copyright © 2004 John Wiley & Sons, Ltd.
Distinct expression and distribution of vesicular proteins in the hippocampus of TNFa‐deficient mice during development
Authors: Golan Hava , Levav Tamar , Huleihel Mahmoud
Published: April 2004

Tumor necrosis factor alpha (TNFa) is a cytokine produced mainly by cells of the immune system. It is also expressed by brain neurons and glia. In the brain, TNFa governs synaptic plasticity, such as long‐term potentiation and learning. Using TNFa‐deficient mice (TNFa‐KO) and immunohistochemical techniques, we resolved the spatio‐temporal effect of TNFa on the expression of vesicular soluble N‐ethylmaleimide‐sensitive factor attachment protein receptor (v‐SNARE) in the presynaptic terminals of the hippocampus during the first month of development. During postnatal days 1–14, the levels of Synaptotagmin I and VAMP II were similar in the hippocampus of TNFa‐KO and wild type (wt) mice. However, the levels of Syntaptotagmin II were reduced in the pyramidal cell layer of the CA1 region in TNFa‐KO. At postnatal day 21, both proteins accomplished comparable levels in the hippocampus of TNFa‐KO and wt mice. In addition, TNFa deficiency impairs the correlation of expression of Synaptotagmin I and II in CA1 region. The expression of those proteins in the CA1 stratum radiatum was uniform during development and similar in both mice groups. Higher expression of all examined proteins was demonstrated in dendritic fields of the CA3 region in TNFa‐KO as compared to wt mice. We suggest that the impairment of synaptic plasticity by TNFa may be related to its modulation of synaptic vesicle proteins. Synapse 53:6–10, 2004. © 2004 Wiley‐Liss, Inc.
Effect of early life stress on serotonin responses in the hippocampus of young adult rats
Authors: Van Riel Els , Van Gemert Neeltje G. , Meijer Onno C. , Joëls Marian
Published: April 2004

In this study, we investigated the effects of early life stress on several aspects of serotonin (5‐HT) transmission in hippocampus, later on in life. Three‐day‐old rats were subjected to 24‐hour maternal deprivation or control treatment. Maternal deprivation is known to activate the hypothalamo‐pituitary‐adrenal axis, resulting in increased corticosterone levels at a time‐point in life when the axis is particularly insensitive to most stressful stimuli. When these animals had matured to 3 months of age, functional responses to 5‐HT as well as 5‐HT1A‐receptor mRNA expression were examined. Also, indices for hypothalamo‐pituitary‐adrenal function were studied in the adult state, including hippocampal mRNA expression for the mineralocorticoid and the glucocorticoid receptor. Resting membrane potential of CA1 pyramidal neurons was significantly depolarized in animals earlier subjected to maternal deprivation compared to the controls. Despite this depolarized resting potential, hyperpolarizing responses induced by 5‐HT in CA1 pyramidal neurons from deprived compared to non‐deprived rats were attenuated. This attenuation in 5‐HT response was not accompanied by changes in mRNA expression of the 5‐HT1A‐receptor. Maternal deprivation was not found to change any of the neuroendocrine parameters investigated once animals had matured. We conclude that maternal deprivation can alter specific aspects of hippocampal 5‐HT transmission later on in life, possibly by post‐translational modification of the 5‐HT1A‐receptor or changes in the 5‐HT1A‐receptor signal transduction pathway. Synapse 53:11–19, 2004. © 2004 Wiley‐Liss, Inc.
Erosive form of lichen planus
Authors: Kyrmizakis Dionysios E. , Papadakis Chariton E.
Published: April 2004

A 55‐year‐old edentulous man was referred to Venizelion Hospital with a long‐standing symptom of burning and painful mouth, particularly while eating. During the previous 10 months he had seen several physicians and had been treated with many different medications, without resolution of his symptoms. He was otherwise healthy and denied a history of smoking or excessive alcohol intake.
Hearing ability by telephone of patients with cochlear implants
Authors: Ito Juichi , Nakatake Mitsuko , Fujita Shuji
Published: April 2004

We investigated the telephone communication ability of patients with cochlear implants who could understand conversations in natural voice without difficulty. The hearing ability of those patients with telephone adapters, which usually are used to reduce noise level in the telephone and to record into a tape recorder, was also investigated. Vowel‐confusion, consonant‐confusion, and speech‐tracking test results of patients listening to voices by telephone and by telephone adapter were compared with those of patients listening to natural, nontelephone voices. The average score of the speech‐tracking test with natural voice was 111.5 phrases per 5 minutes. This score dropped to 62.4 by telephone. However, with a telephone adapter, the score of the speech‐tracking test was 109.3 phrases per 5 minutes. This was almost the same score as that of the natural voice. So, generally speaking, the telephone communication ability of cochlear implant patients was not good enough. However, hearing ability with a telephone adapter came close to hearing ability during natural speech.
Skin: An unusual site of metastases in nasopharyngeal carcinoma
Authors: Taşlkin Yüucel Ö , Hoşlal A. Şlefik , Önerci Metin , Sőukmensüer Cenk
Published: April 2004

Nasopharyngeal carcinoma, because of its aggressive nature, is capable of causing significant distant metastasis to the bone, lung, and liver.1 Metastasis to the skin, although reported, is very unusual for nasopharyngeal carcinoma. We present 2 cases of metastasis to the skin that occurred in patients with nasopharyngeal carcinoma.
Mandibular sclerosing osteomyelitis of Garré
Authors: Martin‐Granizo Rafael , Garcia‐Gonzalez Dolores , Sastre Jesus , Diaz Francisco J.
Published: April 2004

Since 1893, when Carl Garréa1 described the features of the sclerosing osteomyelitis, few reports have been published. This is a rather rare disease also named periostitis ossificans, nonsuppurative chronic osteomyelitis, and chronic osteomyelitis with proliferative periostitis. It is defined as an intense proliferation of periosteum with reactive peripheral bone formation caused by a slight irritation or infection without necrosis or purulent exudate.2
Application of Kolmogorov entropy to the self-amplified spontaneous emission free-electron lasers
Authors: Zhang Shi-Chang , Elgin John
Published: April 2004

Based on the numerical simulation of Kolmogorov entropy, the dynamic behavior is investigated for the relativistic electrons injected into the wiggler in a self-amplified spontaneous emission free-electron laser system. Results show an interesting phenomenon that the self-fields of the electron beam have an effect of stabilizing the electron’s dynamic behavior. It is found that the adiabatic magnetic field of one-dimensional wiggler has trivial influence to the dynamic stability, although it is helpful to the electrons to enter the cavity smoothly. Moreover, the laser field deteriorates the stability of the electron’s dynamic behavior as it grows exponentially and becomes very strong in the rear range.
Influence of plasma environments on photoionization of atoms
Authors: Zhao L. B. , Ho Y. K.
Published: April 2004

Within the framework of the method of the complex-coordinate rotation, a computational scheme has been developed to investigate influence of plasma environments on photoionization for atoms and ionized atoms. The Debye screening potential is used to describe effects of the plasma environments. Photoionization cross sections are reported for hydrogen and hydrogen-like helium in the ground states and compared with the available data. Investigation shows that near the ionization thresholds, photoionization is sensitive to the plasma screening. The strong screening remarkably alters the photoionization cross sections near the ionization thresholds. It is concluded that a great error may arise if photoionization cross sections for isolated atoms or ions are employed for numerical simulations of astrophysical and laboratory plasmas.
Propagation of thermal and hydromagnetic waves in an ionizing-recombining hydrogen plasma
Authors: Di G. Sigalotti Leonardo , Sira Eloy , Rendón Otto , Tremola Ciro , Mendoza-Briceño César A.
Published: April 2004

The propagation of thermal and magnetohydrodynamic (MHD) waves in a heat-conducting, hydrogen plasma, threaded by an external uniform magnetic field (B) and in which photoionization and photorecombination [H++e−⇌H+hν(χ)] processes are progressing, is investigated here using linear analysis. The resulting dispersion equation is solved analytically for varied strength (β≪1 and ∼1) and orientation of the magnetic field, where β denotes the ratio of plasma to magnetic pressures. Application of this model to the interstellar medium shows that heat conduction governs the propagation of thermal waves only at relatively high frequencies regardless of the plasma temperature, strength, and orientation of the magnetic field. When the direction of wave propagation is held perpendicular to B (i.e., k ⊥B), the magnetosonic phase velocity is closely Alfvénic for β≪1, while for β∼1 both the hydrostatic and magnetic pressures determine the wave velocity. As long as k ∥B, the fast (transverse) magnetosonic wave becomes an Alfvén wave for all frequencies independent of the plasma temperature and field strength, while the slow (longitudinal) magnetosonic wave becomes a pure sound wave. Amplification of thermal and MHD waves always occur at low frequencies and preferentially at temperatures for which the plasma is either weakly or partially ionized. Compared to previous analysis for the same hydrogen plasma model with B=0, the presence of the magnetic field makes the functional dependence of the physical quantities span a longer range of frequencies, which becomes progressively longer as the field strength is increased.