bluuebunny/crossref_metadata_2025 huggingface dataset:
Successful pregnancy outcome in a patient with Fabry disease receiving enzyme replacement therapy with agalsidase alfa
Authors: Wendt S. , Whybra C. , Kampmann C. , Teichmann E. , Beck M.
Published: September 2005

Fabry disease is an inherited lysosomal storage disease caused by deficiency of α‐galactosidase A. Enzyme replacement therapy for this multisystem progressive disease has been available only since 2001. We here report the first known successful pregnancy of a female patient receiving such therapy.
mtDNA single macrodeletions associated with myopathies: Absence of haplogroup‐related increased risk
Authors: Goios A. , Nogueira C. , Pereira C. , Vilarinho L. , Amorim A. , Pereira L.
Published: September 2005

As for any non‐recombining genome, any mutation at mtDNA, if not recurrent, appears on a particular haplotype background, allowing its detection by haplogroup association studies. It has been shown that the propensity for occurrence of single macrodeletions at a level beyond the pathological threshold is associated with super‐haplogroup U/K. However, in this report, we present evidence for the absence of preferential haplogroup backgrounds for single macrodeletions. We have analysed how haplogroup diagnostic polymorphisms could disrupt direct repeats usually flanking the deleted segment, and we have concluded that for the Common Deletion, no such polymorphisms are observed in humans, but they do occur in other primates. Furthermore, we also report five new single macrodeletions.
Bone marrow transplantation correcting β‐galactosidase activity does not influence neurological outcome in juvenile GM1‐gangliosidosis
Authors: Shield J. P. H. , Stone J. , Steward C. G.
Published: September 2005

Donor bone marrow engraftment, which resulted in complete normalization of white cell β‐galactosidase levels in a patient with presymptomatic juvenile onset GM1‐gangliosidosis (McKusick 230600), did not improve long‐term clinical outcome.
Hereditary coproporphyria: Comparison of molecular and biochemical investigations in a large family
Authors: Allen K. R. , Whatley S. D. , Degg T. J. , Barth J. H.
Published: September 2005

Hereditary coproporphyria (HCP) is the least common of the three autosomal dominant acute porphyrias. To compare the sensitivity of metabolite measurements for the identification of asymptomatic HCP, we carried out a molecular and biochemical investigation of a large family in which HCP is caused by a previously unreported frameshift mutation (c.119delA). Thirteen of 19 asymptomatic family members, aged 10–72 years, were shown by mutational analysis to have HCP. The faecal coproporphyrin isomer III:I ratio was increased in all of these 13 family members; faecal total porphyrin concentration and urinary porphyrin excretion were increased in 11 and 8 of them, respectively. Plasma porphyrin concentrations were marginally increased in three individuals and plasma fluorescence emission scanning showed a porphyrin peak at 618 nm in two of these. Our results add to the evidence that an increased faecal porphyrin coproporphyrin III:I ratio is a highly sensitive test for the detection of clinically latent HCP in individuals over the age of 10 years; its sensitivity below this age remains uncertain. They also show that plasma fluorescence emission scanning is not useful for the investigation of families with HCP.
New haplotype for the Glu104Asp mutation in triose‐phosphate isomerase deficiency and prenatal diagnosis in a Spanish family
Authors: Repiso A. , Corrons J. L. Vives , Vulliamy T. , Killeen N. , Layton M. , Carreras J. , Climent F.
Published: September 2005

First‐trimester prenatal diagnosis was undertaken by chorionic villus DNA analysis in a Spanish family with the inherited Glu104Asp triose‐phosphate isomerase deficiency. The fetus was heterozygous for the mutation and therefore predicted to be clinically unaffected. To investigate the evolutionary origin of this mutation, studies were conducted on the intragenic 2262A/G polymorphism and the CD4 pentameric tandem repeat marker. A different haplotype was found to the one previously described, suggesting a different origin of the Spanish mutation.
Role of conserved cysteines in mediating sulfur transfer from IscS to IscU
Authors: Smith Archer D. , Frazzon Jeverson , Dean Dennis R. , Johnson Michael K.
Published: September 2005

The role of the three conserved cysteine residues on Azotobacter vinelandii IscU in accepting sulfane sulfur and forming a covalent complex with IscS has been evaluated using electrospray‐ionization mass spectrometry studies of variants involving individual cysteine‐to‐alanine substitutions. The results reveal that IscS can transfer sulfur to each of the three alanine‐substituted forms of IscU to yield persulfide or polysulfide species, and formation of a heterodisulfide covalent complex between IscS and Cys37 on IscU. It is concluded that S transfer from IscS to IscU does not involve a specific cysteine on IscU or the formation of an IscS–IscU heterodisulfide complex.
Adenovirus‐mediated silencing of Synaptotagmin 9 inhibits Ca2+‐dependent insulin secretion in islets
Authors: Iezzi Mariella , Eliasson Lena , Fukuda Mitsunori , Wollheim Claes B.
Published: September 2005

Synaptotagmins (Syts) are involved in Ca2+‐dependent insulin release. However, which Syt isoform is functional in primary β‐cells remains unknown. We demonstrate by electron microscopy of pancreatic islets, the association of Syt 9 with insulin granules. Silencing of Syt 9 by RNA interference adenovirus in islet cells had no effect on the expression of Syt 5, Syt 7 and Syt 3 isoforms. The latter was localized at the plasma membrane of pancreatic polypeptide cells. Insulin release in response to glucose or tolbutamide was strongly inhibited in Syt 9 deficient islets, whereas exocytosis potentiated by raising cAMP levels, was unaltered. Thus, Syt 9 may act as Ca2+ sensor for β‐cell secretion.
In vivo evidence for an increase in 5alpha‐reductase activity in the rat central nervous system following morphine exposure
Authors: Amini Hossein , Ahmadiani Abolhassan
Published: September 2005

In the present study, the effects of acute and chronic morphine exposure on testosterone concentrations in the central nervous system (CNS) and serum were investigated in rats. Acute morphine administration (5 mg/kg, sc) reduced significantly testosterone levels in serum and spinal cord but not in the brain. Following chronic morphine administration (orally for 21 days), the brain testosterone was also significantly reduced as well as serum and spinal cord. Since, the decrease in testosterone levels following morphine exposure was more obvious in the CNS than serum, we suggested that it cannot be caused by only a direct decline in testosterone levels in periphery, and an increased local metabolism of testosterone in the CNS might be attributed in these effects. This hypothesis was supported with the findings that pretreatment with finasteride, a 5alpha‐reductase inhibitor (5 mg/kg, sc) blocked testosterone elimination from the CNS following morphine exposure. Moreover, the serum concentration of 5alpha‐reduced metabolites of testosterone, dihydrotestosterone and 3alpha‐diol glucuronide was increased significantly following chronic morphine exposure, but not after co‐treatment with finasteride. These results suggest that morphine exposure increase the CNS activity of 5alpha‐reductase, which is an important metabolizing enzyme for testosterone.
NGF and IL‐1β are co‐localized in the developing nervous system of the frog, Xenopus laevis
Authors: Jelaso Anna M. , DeLong Cari
Published: September 2005

NGF, a neurotrophic factor best known for its role in promoting cell survival, regulates many neurodevelopmental processes, including synaptic plasticity, neurite outgrowth and programmed cell death. Although there is a large amount of data regarding NGF in the developing nervous system of many species, there is little known about its regulation and role in the frog, Xenopus laevis. In this report, immunocytochemistry was used to characterize NGF protein expression in developing tadpoles. Protein expression was analyzed in tadpoles from stage 44/45 through stage 50, a period of development characterized by extensive neurite outgrowth, neuronal differentiation and an initial period of programmed cell death. Similar to other species, NGF was expressed in sensory cells and tissues, including the inner ear, eye, olfactory system, lateral line organs, papillae in the oral cavity, and gills tufts. In addition, NGF was expressed in specific cells in the central nervous system, cranial and dorsal root ganglia, spinal sensory and motoneurons, and muscle tissues in the tail and body cavity.

In the mammalian nervous system, the cytokine, interleukin‐1β (IL‐1β) induces expression of NGF. In this report, double‐label immunocytochemistry was used to determine the relationship between NGF and IL‐1β. Results showed most cell types and/or tissues that expressed NGF also expressed IL‐1β. However, NGF was typically associated with cellular and nuclear membranes, whereas IL‐1β appeared in the cytoplasm and nucleolus. The nuclear localization of IL‐1β supports the idea that it regulates gene transcription in the frog. The appearance of NGF and IL‐1β in the same cells suggests they may interact to influence neural development.
In Scaphoid Non-Union, Does the Source of Graft Affect Outcome? Iliac Crest Versus Distal End of Radius Bone Graft
Authors: TAMBE A. D. , CUTLER L. , MURALI S. R. , TRAIL I. A. , STANLEY J. K.
Published: September 2005

Iliac crest bone grafts are sometimes preferred to other bone grafts for the treatment of non-unions of fractures of the scaphoid as they are claimed to have better osteogenic potential and biomechanical properties. We retrospectively studied a consecutive cohort of 68 symptomatic established scaphoid non-unions treated by bone grafting. An iliac crest graft was used in 44 cases and a distal radius graft in the other 24. The two treatment groups were comparable in terms of location of the fracture, duration of the non-union and the fixation implants used. Overall union was achieved in 45 of the 68 patients (66%) and the union rate was not influenced by the type of bone graft used. Twenty-nine of the 44 treated with iliac crest bone graft (66%) and 16 of the 24 (67%) treated with distal radial graft united. Donor site pain over the iliac crest was present in nine of the 44 patients in this group.
High-Pressure Injection Injuries of the Hand in a Chinese Population
Authors: WONG T. C. , IP F. K. , WU W. C.
Published: September 2005

We performed a retrospective review of 28 digits in 28 patients who suffered high-pressure injection injuries of the hand during the last 10 years. They were all men, with a mean age of 36 years. All were work injury and the injuries were classified into mild, moderate and severe and were either treated conservatively or surgically. There were seven patients with mild injuries and six of these were successfully treated by conservative methods. Sixteen patients had moderate injuries and all were successfully treated with repeated debridement and delayed direct closure. The index fingers of two severely injured patients were salvaged with digital artery flaps and the remainder of the involved fingers were amputated. The authors advocate proper identification of mild injuries to allow conservative treatment, the application of digital artery flaps for resurfacing large finger defects and have formulated a treatment protocol according to the severity of the injury.
The Role of Atypical Bacteria in Chronic Rhinosinusitis
Authors: Lee Raymond E. , Kaza Sarita , Plano Gregory V. , Casiano Roy R.
Published: September 2005

OBJECTIVE

This study examines the presence of atypical bacteria in chronic rhinosinusitis (CRS) by utilizing the polymerase chain reaction (PCR).

STUDY DESIGN AND SETTING

Eleven patients with CRS were prospectively enrolled. DNA was isolated from the mucosa samples and subjected to PCR using oligonucleotides specific for identification of atypical bacteria including: Mycoplasma pneumoniae, Chlamydia pneumoniae, and Legionella pneumophila. Also, routine aerobic and anerobic cultures were processed. Sinus tissue samples from 6 fresh corpses without evident sinus disease served as controls.

RESULTS

No atypical bacteria were identified in the 11 patient samples by PCR. One of 6 cadaver controls was positive by PCR for M pneumoniae. The most common organism obtained from routine culture was coagulase negative staphylococci.

CONCLUSION

Using sensitive PCR techniques, CRS mucosa did not reveal DNA from M pneumoniae, C pneumoniae, or L pneumophila.

SIGNIFICANCE

Atypical bacteria were not identified in patients with CRS despite highly effective PCR methods and they may not play a significant role in the cause of CRS.
A Comparison of Negative‐Pressure Dressings Versus Bolster and Splinting of the Radial Forearm Donor Site
Authors: Vidrine D. Macy , Kaler Steven , Rosenthal Eben L.
Published: September 2005

OBJECTIVE

Negative‐pressure dressings (NPDs) have been reported to improve split‐thickness skin graft survival in some settings; we assessed whether NPDs could improve skin graft results in radial forearm donor sites.

METHODS

Between October 2003 and November 2004, 45 radial forearm donor sites underwent split‐thickness skin graft immobilization either with conventional bolster dressing and splint or with an NPD. Split‐thickness skin graft take was recorded at 1 and 4 weeks postoperatively.

RESULTS

Overall split‐thickness skin graft healing was improved in the NPD group (92%) compared with the case of conventional splinting (81%) at 4 weeks (P =. 10). The rate of major graft loss was less in NPDs (10%) compared with the case of conventional management (28%) after 4 weeks (P =. 06).

CONCLUSIONS

Split‐thickness skin graft survival was significantly improved by the use of NPDs. Because the use of NPDs is expensive, we consider their use only in patients with potential wound‐healing problems, when there is a need to monitor the hand, or when immediate postoperative hand immobilization might impede the patient's recovery.
New Endoscopic Instruments for Paranasal Sinus Surgery
Authors: Bumm Klaus , Wurm Jochen , Bohr Christopher , Zenk Johannes , Iro Heinrich
Published: September 2005

BACKGROUND

Minimally invasive endoscopic and microscopic procedures represent state of the art paranasal sinus surgery techniques in both diagnostic and surgical fields. To combine favorable aspects of both techniques, we evaluated the clinical applicability and effectiveness of multifunctional microendoscopes, providing multiple features to ensure highest accuracy and surveillance when performing crucial steps in paranasal sinus surgery.

METHODS

The study included both anatomic experiments on cadaveric heads and clinical tests on patients undergoing routine paranasal surgery. The systems applicability was evaluated in procedures approaching the frontal and sphenoid sinus. Three different endoscopes, 2 straight and the other 1 with a 90° angle, were tested. They integrate canals for flushing and suction and a working canal for either drilling or obtaining biopsies with a miniaturized forceps. For stereotactic feedback, the applicability in combination with a computer‐navigation system was evaluated.

RESULTS

Anatomic tests were performed to optimize illumination and to test drilling features and forceps biopsies. In all cases, the frontal sinus ostium and the sphenoid sinus anterior wall was easily identified and enlarged by drilling under visual and stereotactic control. Continuous suction and irrigation ensured a constant visual surveillance by removing drilling debris and blood. Best suited for multifunctional endoscopic surgery were drill heads with a cylinder shape, for placing bore holes along the Z axis, and spherical drill heads, for furbishing and enlarging drill holes.

CONCLUSION

These new instruments have proven their applicability in paranasal sinus surgery. Multifunctional endoscopic procedures were deemed best suited for maneuvers requiring highest precision, such as the surgery of the frontal and sphenoid sinus.
Anatomic Changes After Hyoid Suspension for Obstructive Sleep Apnea: An MRI Study
Authors: Stuck Boris A. , Neff Wolfgang , Hörmann Karl , Verse Thomas , Bran Gregor , Baisch Alexander , Düber Christoph , Maurer Joachim T.
Published: September 2005

OBJECTIVE

To assess the effects of isolated hyoid suspension on subjective and objective parameters of obstructive sleep apnea and to evaluate changes in upper airway anatomy with the help of standardized magnetic resonance imaging.

STUDY DESIGN AND SETTING

Fifteen patients received isolated hyoid suspension. Changes in respiratory disturbance index were assessed with polysomnography, and anatomical changes with standardized magnetic resonance imaging. Snoring, daytime sleepiness, and functional parameters were assessed with questionnaires. Lateral x‐ray cephalometry was performed preoperatively.

RESULTS

Mean respiratory disturbance index was reduced from 35.2 ± 19.1 to 27.4 ± 26.2. Forty percent of the patients were classified as responders. Daytime sleepiness improved significantly. Relevant changes in upper airway anatomy could not be detected. There were no remarkable differences between responders and nonresponders in regard to imaging.

CONCLUSIONS

Hyoid suspension is effective only in a subgroup of patients and does not lead to relevant changes in airway diameters in the awake patient. Magnetic resonance imaging and x‐ray cephalometry do not add additional information for patient selection.

SIGNIFICANCE

The reported clinical effects of hyoid suspension are more likely due to functional changes in airway collapsibility than to an enlargement of the upper airway.
a tigrinya letter from an eritrean notable
Authors: ullendorff edward
Published: September 2005

tigrinya (t[schwa]gr[schwa]ňňa) is, next to amharic, the most widely spoken semitic language in ethiopia, mainly in the tigre province and in eritrea. in most respects it is closer to the orthodox semitic typology than amharic. in terms of the number of semitic language speakers in general it follows arabic and amharic and surpasses hebrew by those who speak that language indigenously.
The acquisition of auxiliaries BE and HAVE: an elicitation study*
Authors: THEAKSTON ANNA L. , LIEVEN ELENA V. M.
Published: September 2005

Auxiliary syntax is recognized to be one of the more complex aspects of language that children must acquire. However, there is much disagreement among researchers concerning children's early understanding of auxiliaries, with some researchers advocating a relatively abstract grammar as the basis for auxiliary syntax, while others view the acquisition of auxiliary syntax as the gradual accumulation of linguistic knowledge, initially tied to individual lexical items. To investigate the status of children's early knowledge of auxiliary syntax, two studies were carried out. In study 1, 28 children (M=3;1) were tested for their use of the auxiliaries BE and HAVE in declaratives, while in study 2, 19 children (M=3;3) were tested for their use of these auxiliaries in questions. Although overall error rates were low, there were differences between BE and HAVE in the proportion and types of errors observed in declaratives and questions, and some individual children showed very high error rates. The implications of these findings for different models of auxiliary syntax in children's early utterances are discussed.
Cellulitis incidence in a defined population
Authors: ELLIS SIMONSEN S. M. , VAN ORMAN E. R. , HATCH B. E. , JONES S. S. , GREN L. H. , HEGMANN K. T. , LYON J. L.
Published: September 2005

A population-based insurance claims database was used to examine cellulitis incidence, anatomical sites of infection, complicating diagnoses, source of health service, and recurrence rates. Insurance claim files were searched for cellulitis ICD-9-CM codes 681.0–682.9. Complications of cellulitis including erysipelas, lymphadenitis, lymphangitis, and necrotizing fasciitis were also identified by ICD-9-CM codes. We found a cellulitis incidence rate of 24·6/1000 person-years, with a higher incidence among males and individuals aged 45–64 years. The most common site of infection was the lower extremity (39·9%). The majority of patients were seen in an outpatient setting (73·8%), and most (82·0%) had only one episode of cellulitis during the 5-year period studied. There was a very low incidence of cellulitis complications, including necrotizing fasciitis. Cellulitis is fairly common, usually treated in outpatient settings, and is infrequently complicated by erysipelas, lymphadenitis, lymphangitis, or necrotizing fasciitis.
Challenges in identifying the methodology to estimate the prevalence of infectious intestinal disease in Malta
Authors: GAUCI C. , GILLES H. , O'BRIEN S. , MAMO J. , STABILE I. , RUGGERI F. , MICALLEF C. C.
Published: September 2005

Routine surveillance systems capture only a fraction of infectious intestinal disease (IID) that is actually occurring in the community. Different methodologies utilized among various international studies in the field were reviewed in order to devise an appropriate survey to obtain current estimates of prevalence of IID in Malta. An age-stratified retrospective cross-sectional telephone study was selected for the study due to its feasibility in terms of limited resources necessary (funds, time and human). The disadvantages of this type of study include the inherent biases such as selection bias (sampling, ascertainment and participation bias) and information bias (recall and observer bias). A pilot study was carried out using a random age-stratified sample of 100 persons over a 3-month period. A total of 5·0% (95% CI ±4·27) of the population was estimated to have suffered from IID during that period. This estimate was used in order to assist in sample size calculations for a large-scale community study. It also served to test the survey instrument and methodology and to identify operational problems.
Avant-gardes in the First Half of the Twentieth Century: New Perspectives
Authors: BANDIER NORBERT
Published: September 2005

The time has come for researchers into innovative movements in art and literature in the first half of the twentieth century to break free from traditional investigative frameworks. The works reviewed here belong to different disciplines – art history, literary history, literary criticism, history – but all show a shift of perspectives in the history of culture. They point to a reassessment of the theoretical models we use to understand modern art and literature. Those models are – in this case as they relate to the avant-garde – nuanced, refined, developed and sometimes even invalidated. Though some of these works are not wholly devoted to the European avant-gardes, they do deal with the international circulation of modern art in, to or from Europe, studied here in its lesser-known aspects. Moreover, they all to some extent examine the artist’s responsibility to the community, or the state’s responsibility to art. This theme of responsibility runs through all these works, either in its ethical dimension or as an aspect of the social function of art, especially when art has to confront an entertainment culture or is roped in as part of cultural policy.
Simulations of water isotope abundances in the upper troposphere and lower stratosphere and implications for stratosphere troposphere exchange
Authors: Gettelman Andrew , Webster Christopher R.
Published: September 2005

An analytic model of transport and microphysics in the tropical tropopause layer (TTL) is extended to include stable isotopes of water. The model, running along trajectories, is tested against in situ and satellite observations of HDO and H218O in the Upper Troposphere and Lower Stratosphere (UT/LS). The model is able to reproduce the range of isotopic depletions observed in the data, and reproduce individual episodes that mirror or depart from Rayleigh fractionation processes. The results indicate that water substance in the upper troposphere does not follow a Rayleigh distillation model due to the presence of condensed phase water. Stratospheric abundances of stable isotopes of water can be understood based on known isotopic physics, convective transport of ice, and gradual dehydration.
Formation and behavior of aeolian streamers
Authors: Baas A. C. W. , Sherman D. J.
Published: September 2005

Field experiments were conducted to determine the characteristic spatial and temporal dimensions and behavior of aeolian streamers and to identify the processes responsible for their formation. An instrument array that included anemometer towers, piëzo‐electric transport sensors (Safires), and hot‐film probes was deployed to measure streamers and airflow dynamics on both a coastal dune and a desert sand mound in California. Aeolian transport occurs predominantly in the form of families of intertwining and bifurcating streamers, while under intense wind forcing, more complex patterns of nested streamers and clouds with embedded streamers develop. The streamers display a characteristic width of approximately 0.2 m and an average lateral spacing of about 1 m. These dimensions appear to be independent of mean airflow characteristics. The observations and measurements of streamers under different environmental conditions suggest that bed surface control in the form of differentiation in moisture content, grain size, or microtopography is not a necessary condition for the formation of streamers. The results show little correlation between possible streamwise vortices or burst sweep events and streamers. It is proposed that streamers are generated by near‐surface gusts that originate from large eddies propagating to the ground from higher regions of the boundary layer. These elongated and stretched eddies scrape across the surface and initiate saltation along their path. This concept accounts for the characteristic size and spacing of streamers, their rapid propagation, and the fast response of saltation to wind speed fluctuations.
Disruption of E region echoes observed by the EAR during the development phase of equatorial spread F: A manifestation of electrostatic field coupling
Authors: Patra A. K. , Yokoyama T. , Yamamoto M. , Saito S. , Maruyama T. , Fukao S.
Published: September 2005

Simultaneous observations of E‐ and F‐ region irregularities made using the Equatorial Atmosphere Radar (EAR) are presented to study the coupling between the E‐ and F‐ region. The observations clearly suggest that the disruption of E region field aligned irregularities (FAI) over the EAR is closely associated with the development phase of equatorial plasma bubble. The observed coupling effects on the low latitude E region FAI during the development phase of equatorial bubble are found to be quite pronounced over the EAR. This is consistent with the fact that the E region over the EAR connects the F region over the equator, where strong polarization electric fields are generated in association with equatorial plasma bubble phenomenon. Relatively weak vertical downward electric field and large eastward polarization electric field associated with plasma density depletion in the evening equatorial ionosphere, which map to low latitude E region over the EAR, are proposed to be responsible for the inhibition of growth of irregularities.
First measurements of the latitudinal atmospheric O2 and CO2 distributions across the western Pacific
Authors: Tohjima Y. , Mukai H. , Machida T. , Nojiri Y. , Gloor M.
Published: September 2005

We examine the latitudinal distribution of the tracer “atmospheric potential oxygen” APO = O2 + 1.1 × CO2 between 40°S and 50°N using new atmospheric CO2 and O2 measurements from flask samples collected onboard cargo ships between Japan and the United States, and Japan and Australia (or New Zealand) during the period from December 2001 to August 2004. Because APO is unaltered during photosynthesis and respiration by land vegetation, its atmospheric distribution is tightly linked to the air‐sea gas exchange of O2 and CO2 and the underlying processes. We find that the seasonal amplitude of APO increases towards high latitudes in both hemispheres and its minimum is located approximately 10‐degree north of the equator. The latitudinal distribution of annual mean APO shows a maximum in the tropics, confirming the recent coupled ocean‐atmosphere model predictions for this region.
A direct method for locating minimum-energy crossing points (MECPs) in spin-forbidden transitions and nonadiabatic reactions
Authors: Chachiyo Teepanis , Rodriguez Jorge H.
Published: September 2005

An efficient computational method for locating minimum-energy crossing points (MECPs) between potential-energy surfaces in spin-crossover transitions and nonadiabatic spin-forbidden (bio)chemical reactions is introduced. The method has been tested on the phenyl cation and the computed MECP associated with its radiationless singlet-triplet spin crossover is in good agreement with available data. However, the convergence behavior of the present method is significantly more efficient than some alternative methods which allows us to study nonadiabatic processes in larger systems such as spin crossover in metal-containing compounds. The convergence rate of the method obeys a fast logarithmic law which has been verified on the phenyl cation. As an application of this new methodology, the MECPs of the ferrous complex [Fe(ptz)6](BF4)2, which exhibits light-induced excited spin state trapping, have been computed to identify their geometric and energetic parameters during spin crossover. Our calculations, in conjunction with spin-unrestricted density-functional calculations, show that the transition from the singlet ground state to a triplet intermediate and to the quintet metastable state of [Fe(ptz)6](BF4)2 is accompanied by unusually large bond-length elongations of the axial ligands (≈0.26 and 0.23Å, respectively). Our results are consistent with crystallographic data available for the metastable quintet but also predict new structural and energetic information about the triplet intermediate and at the MECPs which is currently not available from experiment.
A newab initiointeraction energy surface and high-resolution spectra of the H2–CO van der Waals complex
Authors: Jankowski Piotr , Szalewicz Krzysztof
Published: September 2005

A new four-dimensional intermolecular potential-energy surface for the H2–CO complex is presented. The ab initio points have been computed on a five-dimensional grid including the dependence on the H–H separation (the C–O separation was fixed). The surface has then been obtained by averaging over the intramolecular vibration of H2. The coupled-cluster supermolecular method with single, double, and noniterative triple excitations has been used to calculate the interaction energy. The correlation part of the interaction energy has been obtained from extrapolations based on calculations in a series of basis sets. An analytical fit of the ab initio potential-energy surface has the global minimum of −93.049cm−1 at the intermolecular separation of 7.92bohr for the linear geometry with the C atom pointing toward the H2 molecule. For the other linear geometry, with the O atom pointing toward H2, the local minimum of −72.741cm−1 has been found for the intermolecular separation of 7.17bohr. The potential has been used to calculate the rovibrational energy levels of the para-H2–CO complex. The results agree very well with those observed by McKellar [A. R. W. McKellar J. Chem. Phys. 108, 1811 (1998)]: the discrepancies are smaller than 0.1cm−1. The calculated dissociation energy is equal to 19.527cm−1 and significantly smaller than the value of 22cm−1 estimated from the experiment. Predictions of rovibrational energy levels for ortho-H2–CO have also been done and can serve as a guidance to assign recorded experimental spectra. The interaction second virial coefficient has been calculated and compared with the experimental data.
Structural properties of water: Comparison of the SPC, SPCE, TIP4P, and TIP5P models of water
Authors: Zielkiewicz Jan
Published: September 2005

Molecular-dynamics simulations were carried out for the SPC, SPCE, TIP4P, and TIP5P models of water at 298 K. From these results we determine the following quantities: the absolute entropy using the two-particle approximation, the mean lifetime of the hydrogen bond, the mean number of hydrogen bonds per molecule, and the mean energy of the hydrogen bond. From the entropy calculations we find that nearly all contributions to the total entropy originates from the orientation effects. Moreover, we determine the contributions to the total entropy which originate from the first, second, and higher solvation shells. It is interesting that the limits between solvation shells are clearly visible. The first solvation shell (0.22<r<0.36nm) contributes approximately 43J∕molK to the total entropy; the second solvation shell (0.36<r<0.60nm) contributes approximately 12J∕molK, while contributions from the third and other solvation shells are very small, approximately 2J∕molK in summary. This indicates that water molecules are strongly ordered up to 0.55-0.6 nm around the central water molecule, and beyond this limit the ordering diminishes. The results of calculations (entropy and hydrogen bonds) are compared with the experimental data for the choosing of the best water model. We find that the SPC and TIP4P models reproduce the best experimental values, and we recommend these models for computer simulations of the aqueous solution of biomolecules.
Error analyses on some typically approximate solutions of residual stress within a thin film on a substrate
Authors: Zhang X. C. , Xu B. S. , Wang H. D. , WU Y. X.
Published: September 2005

Stoney's equation and subsequent modifications and some approximations are widely used to evaluate the macrostress within a film on a substrate, though some of these solutions are only applicable for thin films. The purpose of this paper is to review the considerable efforts devoted to the analysis of residual stresses in a single-layer film in the last century and recent years and to estimate the errors involved in using these formulas. The following are some of the important results that can be obtained. (1) The exact solution for the residual stress can be expressed in terms of Stoney's equation [Proc. R. Soc. London A82, 172 (1909)] and a correction factor, (1+Ση3)∕(1+η), where Σ,η are the ratios of the elastic modulus and the thickness of the film to those of the substrate, respectively. (2) When the thickness ratio of the film and the substrate is less than 0.1, Stoney's equation and Röll's approximation [J. Appl. Phys. 47, 3224 (1976)] do not cause serious errors. (3) The approximation proposed by Vilms and Kerps [J. Appl. Phys. 53, 1536 (1982)] is an improved modification for Stoney's equation and can be applicable when η≤0.3. (4) The approximations proposed by Brenner and Senderoff [J. Res. Natl. Bur. Stand. 42, 105 (1949)] and Teixeira [Thin Solid Films 392, 276 (2001)] can lead to serious errors and should be avoided. (5) The approximation based on the assumption of constant elastic modulus is only applicable for a ratio of η≤0.01 and can be very misleading.
Magnetic and transport properties of (Mn, Co)-codoped ZnO films prepared by radio-frequency magnetron cosputtering
Authors: Gu Zheng-Bin , Yuan Chang-Sheng , Lu Ming-Hui , Wang Jing , Wu Di , Zhang Shan-Tao , Zhu Shi-Ning , Zhu Yong-Yuan , Chen Yan-Feng
Published: September 2005

(Mn, Co)-codoped ZnO films have been synthesized on c-sapphire (0001) by a radio-frequency magnetron sputtering system in which two targets were sputtered together. X-ray-diffraction measurements indicate that the films are highly c-axis oriented. X-ray photon spectra show that the doped Mn and Co ions in (Mn, Co) ZnO films are both in the divalent states. The films show ferromagnetic behavior with a coercivity of about 90 Oe and a saturation moment of 0.11μB∕(0.3Mn2++0.7Co2+) at 300 K. In the lower temperatures between 5 and 20 K, a relatively large positive magnetoresistance over 10% was observed for (Mn0.03,Co0.07)Zn0.90O film. The number of carrier concentration is experimentally established to be 1.5613×1018cm−3 and the mobility to be 2.815cm2V−1s−1 for (Mn0.03,Co0.07)Zn0.90O film by Hall measurements at 300 K. The origins of the room-temperature magnetism and the large positive magnetoresistance are also discussed.
The effect of interfacial layer on the performance of organic light-emitting diodes
Authors: Choulis Stelios A. , Choong Vi-En , Mathai Mathew K. , So Franky
Published: September 2005

We demonstrate high efficiency organic light-emitting devices by incorporation of a nanoscale interfacial layer between a hole-conducting layer (PEDOT:PSS) and a light-emitting polymer layer (LEP) to improve hole injection. The interfacial layer has appropriate highest occupied molecular orbital level in order to act as a bridge for efficient hole injection from the PEDOT:PSS into the LEP. As an example we have incorporated a suitable interfacial layer into a green-emitting single-layer electrophosphorescent light-emitting diode. Devices with the interfacial layer show a peak efficiency of 41lm∕W, an improvement of more than 25% in their performance over comparable devices without the interfacial layer. The results presented here introduce a novel method to improve hole injection and thus efficiency in organic electroluminescent devices.
Characterization of SnO2 nanowires as an anode material for Li-ion batteries
Authors: Ying Z. , Wan Q. , Cao H. , Song Z. T. , Feng S. L.
Published: September 2005

Sn O 2 nanowires synthesized by thermal evaporation method are investigated as a possible anode electrode for Li-ion batteries. In the first discharge process, the capacity of Li ions is 2133mAhg−1, which is much more than the theoretical total capacity of the bulk SnO2, 1494mAhg−1. During the successive 15cycles, the reversible capacity stays in the range of 1250–700mAhg−1 with a capacity fading of 3.89%percycle at a constant current density of 0.5mAcm−2. These results demonstrate that SnO2 nanowires are a promising anode material for Li-ion battery applications.
Magnetoresistance in epitaxially grown degenerate ZnO thin films
Authors: Reuss F. , Frank S. , Kirchner C. , Kling R. , Gruber Th. , Waag A.
Published: September 2005

The magnetoresistance of high-quality epitaxial doped ZnO(:Ga) thin films with various electron concentrations ranging from 3.2×1018 to 1.3×1020cm−3 has been measured. All samples investigated exhibit a negative magnetoresistance at low magnetic fields. Its magnitude systematically depends on carrier concentration and temperature. Low-doped samples switch the sign of the magnetoresistance and the conventional positive component dominates at high fields, whereas highly doped degenerate samples only show a negative component up to fields of 14.5 T. Therefore, the data are analyzed as the sum of a positive and negative contribution to the magnetoresistance applying a semiempirical expression to describe the observed behavior. The model takes into account third-order s–d exchange Hamiltonians describing the negative part and a two-band model for the positive contribution. Least-squares fits to the data are presented. Theory and experiment are in excellent agreement.
Influence of composition and heat-treatment on the charge transport properties of poly(3-hexylthiophene) and [6,6]-phenyl C61-butyric acid methyl ester blends
Authors: Huang Jinsong , Li Gang , Yang Yang
Published: September 2005

Poly(3-hexylthiophene) (P3HT) and [6,6]-phenyl C61-butyric acid methyl ester (PCBM) blends have been demonstrated to form highly efficient polymer photovoltaic devices. In this letter, the time-of-flight technique is used to investigate the influence of composition and heat treatment on charge transport properties of P3HT and PCBM blends. The transport of electrons and holes both display a transition from dispersive to nondispersive and return to dispersive again as the percentage of PCBM increases. A balanced mobility of both electron and hole is obtained at a composition of 1:1 weight ratio, and it is nearly independent of the electrical field in the range of our test. The increase in carrier mobility is attributed to the formation of a more-ordered structure in the blend. This structural ordering is further enhanced by slowly evaporating the solvent during film formation which results in additional increase in carrier mobility. However, no such effect is observed in thick films (∼200nm), indicating the presence of such high-degree ordering due to heat treatment.
In
Ga
N
∕
Ga
N
multi-quantum-well structures on (111)-oriented bonded silicon-on-insulator substrates
Authors: Wang L. S. , Tripathy S. , Chua S. J. , Zang K. Y.
Published: September 2005

We report growth of InGaN∕GaN multiple quantum wells (MQWs) on (111)-oriented bonded silicon-on-insulator (SOI) substrates by metalorganic chemical vapor deposition (MOCVD). Prior to MOCVD growth of MQWs, about a 1.2μm thick GaN layer was deposited on SOI substrate with a high-temperature transitional buffer layer. The growth conditions were tuned to realize blue-green emission peaks centered around 420–495nm from such MQWs on SOI. X-ray diffraction, atomic force microscopy, scanning electronic microscopy, and photoluminescence techniques were used to characterize these MQWs. Such an approach to realize multicolor light-emitting layers on SOI substrates is suitable for the integration of InGaN∕GaN-based optoelectronic structures on SOI-based micro-optoelectromechanical systems and sensors.
Experimental determination of kinetic parameters for crystallizing amorphous NiTi thin films
Authors: Lee Hoo-Jeong , Ni Hai , Wu David T. , Ramirez Ainissa G.
Published: September 2005

The crystallization of amorphous NiTi thin films was studied using in situ transmission electron microscopy (TEM) methods. Samples were subjected to heating conditions within the microscope and the microstructural development was monitored and recorded. The nucleation rate and the growth rate were determined experimentally by noting the number of new grains per frame and their change in size. These parameters were compared to the conventional method of kinetic analysis using the Johnson-Mehl-Avrami-Kolmogorov (JMAK) theory. In it, the amount transformed is related to fitting parameters that describe the overall crystallization rate. The individual kinetic rates found directly with the TEM methods have considerable agreement with the overall rate determined by the conventional JMAK analysis. This quantitative analysis provides the groundwork for the control of microstructures and properties in NiTi shape memory alloy thin films.
BaTi 4 O 9 thin films for high-performance metal-insulator-metal capacitors
Authors: Jang Bo-Yun , Kim Beom-Jong , Lee Suk-Jin , Lee Kyong-Jae , Nahm Sahn , Sun Ho-Jung , Lee Hwack-Joo
Published: September 2005

The dielectric and electrical properties of a BaTi4O9 film were investigated in order to evaluate its potential use in metal-insulator-metal (MIM) capacitors for rf/mixed signal integrated circuits. A high capacitance density of 4.62fF∕μm2 along with a low tanδ of 0.0025 were obtained at 100 kHz. A high capacitance density of 4.12fF∕μm2 and a high quality factor of 322 were also achieved at 2 GHz. The leakage current density was approximately 1nA∕cm2 at ±2V. Small linear and quadratic voltage coefficients of capacitance of 110ppm∕V and 40.05ppm∕V2, respectively, and a small temperature coefficient of capacitance of −92.157ppm∕°C at 100 kHz were obtained. These results demonstrate that the BaTi4O9 film is a good candidate material for MIM capacitors.
Non-cell-autonomous induction of tissue overgrowth by JNK/Ras cooperation in a
Drosophila
tumor model
Authors: Uhlirova Mirka , Jasper Heinrich , Bohmann Dirk
Published: September 2005

The role of c-Jun N-terminal kinase (JNK) signaling in cancer is enigmatic, and both tumor-promoting and tumor-suppressing functions have been ascribed to JNK pathway components. We have used the
Drosophila
eye to investigate the function of the JNK pathway in three different tumor models of increasing malignancy. Benign lesions caused by loss of the neoplastic tumor suppressor gene
scribble
can efficiently be eliminated by JNK-induced apoptosis. In such a scenario, the eye reverts to a wild-type phenotype, indicating that the JNK pathway prevents tumor formation. The situation changes in the case of aggressive tissue overgrowth, which can be induced by oncogenic activation of the Ras/Raf pathway in the eye, or in malignant invasive tumors resulting when Raf activation is combined with loss of
scribble
. The growth of these more aggressive tumor types is significantly, yet incompletely, suppressed by JNK-mediated apoptosis. Remarkably, oncogenic Raf and JNK cooperate in these tumors, to induce massive hyperplasia in adjacent wild-type tissue. Thus, depending on the genetic context, JNK signaling can eradicate tumors by removing premalignant cells, or promote aberrant overgrowth in tissues surrounding primary lesions.
Electrical synapses in retinal ON cone bipolar cells: Subtype-specific expression of connexins
Authors: Han Yi , Massey Stephen C.
Published: September 2005

Retinal bipolar cells are known to form a complex, interconnecting network through electrical synapses that are either heterologous (with amacrine cells) or homologous (with other bipolar cells). These electrical synapses can be functionally as important as chemical synapses because their distinct properties provide a different character for the network. Much less is known, however, about electrical synapses in retinal bipolar cells than about chemical synapses. Here we report the molecular basis for electrical synapses in retinal bipolar cells, particularly ON cone bipolar cells. We have found variable connexin 36 (cx36) expression in different types of ON cone bipolar cells: cx36 message was found in some, but not all, ON cone bipolar cells (4 of 14 cells). In one specific type of ON cone bipolar cell (BP
Gus-GFP
), however, cx36 was detected in 17 of 19 cells. Moreover, we have located cx36 puncta at the axonal terminals of BP
Gus-GFP
cells, and we have found that these BP
Gus-GFP
-associated cx36 puncta always colocalized with AII amacrine cell processes. Molecular and immunocytochemical evidence obtained in this study also shows that connexin 45 (cx45) is not present in BP
Gus-GFP
cells. Taken together, our results suggest that connexins are expressed in bipolar cells in a neuronal subtype-specific manner and that cx36/cx36 gap junctions form the heterologous electrical synapses between AII amacrine cells and BP
Gus-GFP
cells. Our findings imply that visual information can be differently processed by distinct subtypes of ON cone bipolar cells via electrical synapses.
Probing the structure of a rotaxane with two-dimensional infrared spectroscopy
Authors: Larsen Olaf F. A. , Bodis Pavol , Buma Wybren Jan , Hannam Jeffrey S. , Leigh David A. , Woutersen Sander
Published: September 2005

Femtosecond 2D-IR spectroscopy has been used to study the structure of a [2]rotaxane composed of a benzylic amide macrocycle that is mechanically interlocked onto a succinamide-based thread. Both the macrocycle and the thread contain carbonyl groups, and by determining the coupling between the stretching modes of these groups from the cross-peaks in the 2D-IR spectrum, the structure of the macrocycle-thread system has been probed. Our results demonstrate that 2D-IR spectroscopy can be used to observe structural changes in molecular devices on a picosecond time scale.