bluuebunny/crossref_metadata_2025 huggingface dataset:
Transformation
Authors: Schmitt Neal
Published: September 2005

Transformations are systematic alterations to a set of scores that allow for application of various statistical procedures or better communication to readers. Transformations that often change the mean and standard deviation of a set of scores, but preserve the rank order and relative size of the distance between scores are linear; nonlinear transformations do not preserve these characteristics of the original data. Taking the square or square root or normalizing a set of scores are nonlinear transformations that make multivariate or parametric data analyses procedures more acceptable. Computing percentiles or T scores is often done to provide data in terms that are more easily understood by the statistically unsophisticated audiences.
Generalizability Theory: Overview
Authors: Webb Noreen M. , Shavelson Richard J.
Published: September 2005

Generalizability (G) theory is a statistical theory for evaluating the dependability (reliability) of behavioral measurements. G theory estimates multiple sources of measurement error and permits decision makers to design a measurement procedure that minimizes error.
z

Scores
Authors: Clark‐Carter David
Published: September 2005

A
z
‐score is the difference between a score or statistic and the mean for that score or statistic divided by the standard deviation for that score or statistic. It can be used to form inferential statistics, to find the proportion of a population that has a given score, and to identify possible outliers in a set of scores.
Probability: An Introduction
Authors: Macdonald Ranald R.
Published: September 2005

The concept of a probability as a measure of the uncertainty of an event is introduced. Venn diagrams are shown to be useful as a means of representing probabilities and the basics of set theory are outlined. Treating relative frequencies as probabilities is justified using the law of large numbers and independence as a simplifying principle is explained with the help of conditional probabilities. Finally, a probability analysis is applied to a plausible real life situation.
Latent Class Analysis
Authors: Everitt Brian S.
Published: September 2005

Latent class analysis is in some senses a categorical variable analog of factor analysis used to investigate the classification of subjects according to an underlying categorical latent variable such as racial prejudice or ability. Membership in a particular class of the underlying variable is estimated from a subject's responses to a set of observed categorical variables.
Scatterplot Smoothers
Authors: Everitt Brian S.
Published: September 2005

Fitting a simple linear regression to describe the relationship between two variables is not always adequate. Polynomial fits can be used, but a more satisfactory solution is often achieved by using a locally weighted regression approach or spline functions.
Basic Protein Sequence Analysis
Authors: Krishnamurthy Nandini , Sjölander Kimmen V.
Published: September 2005

Prediction of molecular function of proteins has become an important task in the genomics era. A wide variety of sequence analysis tools are available to biologists for this task. We have selected one or two primary protocols for tasks such as domain detection, subcellular localization, and motif detection. We also present a strategy for integration of results from different protocols. All the resources needed for these protocols are accessible via publicly available Web servers and databases and require little or no computational expertise.
Overview of Digital Electrophoresis Analysis
Authors: Medberry Scott , Gallagher Sean , Moomaw Butch
Published: September 2005

Gel electrophoresis has become a ubiquitous method in molecular biology for separating biomolecules. This prominence is the result of several factors, including the robustness, speed, and potentially high throughput of the technique. The results of this method are traditionally documented using silver halide‐based photography followed by manual interpretation. While this remains an excellent method for qualitative documentation of single‐gel results, digital capture offers a number of significant advantages when documentation requires quantitation and sophisticated analysis. Digital images of gel electropherograms can be obtained rapidly using an image‐capture device, and the images can be easily manipulated using image analysis software. This overview presents reasons for digital documentation and analysis, defines some important key terms for imaging, explains the capture process and reviews the devices used for image capture, and provides an introduction to the software and methods used for one‐ and two‐dimensional digital image analysis.
Visualization of Protein Interactions in Living Cells Using Bimolecular Fluorescence Complementation (BiFC) Analysis
Authors: Hu Chang‐Deng , Grinberg Asya V. , Kerppola Tom K.
Published: September 2005

Protein interactions integrate stimuli from different signaling pathways and developmental programs. Bimolecular fluorescence complementation (BiFC) analysis has been developed for visualization of protein interactions in living cells. This approach is based on complementation between two fragments of a fluorescent protein when they are brought together by an interaction between proteins fused to the fragments, and it enables visualization of the subcellular locations of protein interactions in the normal cellular environment. It can be used for the analysis of many protein interactions and does not require information about the structures of the interaction partners. A multicolor BiFC approach has been developed for simultaneous visualization of interactions with multiple alternative partners in the same cell, based on complementation between fragments of engineered fluorescent proteins that produce bimolecular fluorescent complexes with distinct spectral characteristics. This enables comparison of subcellular distributions of different protein complexes in the same cell and allows analysis of competition between mutually exclusive interaction partners.
Measurement of Fcγ Receptor–Mediated Binding and Phagocytosis
Authors: Politis Alexander D. , Vogel Stefanie N.
Published: September 2005

This unit describes functional assays that quantify macrophage FcγR surface expression. In each assay, IgG‐opsonized sheep red blood cells (SRBC) labeled with Na251CrO4 are used to detect interaction with macrophages. The Basic Protocol measures phagocytosis of target cells following treatment of macrophages with agents known to modulate FcγR expression. The Alternate Protocol describes a method that can be used to measure FcγR‐mediated binding of target cells to macrophages. A choice of opsonin in both methods allows for some discrimination between subclasses of FcγRs that are responsible for the observed results.
Asymmetric Aza‐MoritaBaylisHillman Reaction of N‐Sulfonated Imines with Methyl Vinyl Ketone Catalyzed by Chiral Phosphine Lewis Bases Bearing Perfluoroalkanes as “Pony Tails”
Authors: Shi Min , Chen Lian‐Hui , Teng Wen‐Dong
Published: September 2005

In the aza‐Morita–BaylisHillman reaction of N‐sulfonated imines (N‐arylmethylidene‐4‐methylbenzenesulfonamides and others) with methyl vinyl ketone (MVK), we found that in the presence of a catalytic amount of the chiral phosphine Lewis bases (R)‐(−)‐6,6′‐bis[tris(3,3,4,4,5,5,6,6,7,7,8,8,8‐tridecafluorooctyl)silyl]‐2′‐(diphenylphosphanyl)‐[1,1′]binaphthalenyl‐2‐ol LB2 and (R)‐(−)‐6,6′‐(3,3,4,4,5, 5,6,6,7,7,8,8,8‐tridecafluorooctyl) ‐2′‐(diphenylphosphanyl)‐[1,1′]binaphthalenyl‐2‐ol LB3 bearing two perfluoroalkane chains at 6,6′‐positions of the naphthalene framework, the corresponding adducts could be obtained in good yields with good to high ee (52–95% ee) at room temperature (15 °C) or low temperature (−20 °C) in THF, respectively. LB3 is more effective in this reaction than the previously reported original chiral phosphine Lewis base (R)‐(−)‐2′‐diphenylphosphanyl‐[1,1′]binaphthalenyl‐2‐ol LB1.
Palladium‐Catalysed Enantioselective Conjugate Addition of Aromatic Amines to α,β‐Unsaturated N‐Imides. Effect of the Chelating Moiety
Authors: Phua Pim Huat , de Vries Johannes G. , Hii King Kuok (Mimi)
Published: September 2005

Palladium‐catalysed enantioselective additions of aromatic amines to α,β‐unsaturated N‐imides 4–6 are reported. The N‐substituent of the Michael acceptor appears to have an unusual modulating effect on the amine activity. The effects of introducing different substituents are examined. Overall, the yield and selectivity of the system appear to be less sensitive to environmental effects than previous systems. The importance of the counteranion is revealed.
Synthesis of an Enantiocomplementary Catalyst of β‐Isocupreidine (β‐ICD) from Quinine
Authors: Nakano Ayako , Ushiyama Mina , Iwabuchi Yoshiharu , Hatakeyama Susumi
Published: September 2005

Compound 20, a pseudoenantiomer of β‐isocupreidine (β‐ICD), was synthesized from quinine employing a Barton reaction of nitrosyl ester 13 and acid‐catalyzed cyclization of carbinol 18 as key steps. The Baylis–Hillman reaction of benzaldehyde, p‐nitrobenzaldehyde, and hydrocinnamaldehyde with 1,1,1,3,3,3‐hexafluoroisopropyl acrylate (HFIPA) using 20 as a chiral amine catalyst was found to give the corresponding S‐enriched adducts in high optical purity (>91% ee) in contrast to the β‐ICD‐catalyzed reaction which affords R‐enriched adducts. This result suggests that compound 20 can serve as an enantiocomplementary catalyst of β‐ICD in the asymmetric Baylis–Hillman reaction of aldehydes with HFIPA.
Airborne laser altimetry in alluviated landscapes
Authors: Challis Keith
Published: September 2005

Scanning airborne laser altimetry, usually referred to as LiDAR, generates high spatial resolution, high accuracy elevation data. The technique has found considerable use in the earth sciences, for example for flood modelling and prediction. This paper examines some geoarchaeological applications for LiDAR in alluviated landscapes. The LiDAR data for several lowland river valleys in England are examined. The technique has considerable potential for identifying archaeologically significant geomorphological features through examination of the microtopography of floodplain and terrace surfaces and for mapping upstanding archaeological earthworks. Copyright © 2005 John Wiley & Sons, Ltd.
Evaluating the effectiveness of and patterns of interactions with automated searching assistance
Authors: Jansen Bernard J. , McNeese Michael D.
Published: September 2005

We report quantitative and qualitative results of an empirical evaluation to determine whether automated assistance improves searching performance and when searchers desire system intervention in the search process. Forty participants interacted with two fully functional information retrieval systems in a counterbalanced, within‐participant study. The systems were identical in all respects except that one offered automated assistance and the other did not. The study used a client‐side automated assistance application, an approximately 500,000‐document Text REtrieval Conference content collection, and six topics. Results indicate that automated assistance can improve searching performance. However, the improvement is less dramatic than one might expect, with an approximately 20% performance increase, as measured by the number of user‐selected relevant documents. Concerning patterns of interaction, we identified 1,879 occurrences of searcher– system interactions and classified them into 9 major categories and 27 subcategories or states. Results indicate that there are predictable patterns of times when searchers desire and implement searching assistance. The most common three‐state pattern isExecute Query–View Results: With Scrolling–View Assistance.Searchers appear receptive to automated assistance; there is a 71% implementation rate. There does not seem to be a correlation between the use of assistance and previous searching performance. We discuss the implications for the design of information retrieval systems and future research directions.
Out of the mouths of middle school children: I. Developing user‐defined controlled vocabularies for subject access in a digital library
Authors: Abbas June
Published: September 2005

Representation and retrieval obstacles within a digital library designed for use by middle school children are presented. Representation of objects is key to retrieval. Tools used to create representations for children's resources, such as controlled vocabularies, need to be more age appropriate. Development of age‐appropriate controlled vocabularies requires us to learn more about the ways children interact with systems and form search strategies to represent their information needs. Children's search terms and questions are a rich resource for learning more about their information seeking process, their question state, and their formulation of searches. A method for gathering and using children's own search terms and the benefits of their utilization in developing more age‐appropriate controlled vocabularies are discussed.
Scavenging efficiency of rainfall on black carbon aerosols over an urban environment
Authors: Latha K. Madhavi , Badarinath K. V. S. , Reddy P. Manikya
Published: September 2005

Black carbon (BC) aerosols are the optically absorbing part of carbonaceous aerosols that have significantly different optical and radiative properties. The present study addresses the estimation of black carbon aerosol scavenging coefficient by using ground‐based measurements over an urban environment of India, namely, Hyderabad. Extensive ground measurements of black carbon have been carried out during January to December 2004 over a tropical urban environment of Hyderabad. Seasonal variations of black carbon aerosol mass concentration showed high values during dry season and low values during monsoon season. The diurnal variations of BC suggest that the concentrations increased by a factor of ∼2 during morning and evening hours compared to afternoon hours. Drastic reduction in black carbon aerosol loading has been observed during rainy days. The statistical fit between black carbon aerosol mass concentration and rainfall suggests the reduction of ∼3.6 µg/m3 in atmospheric black carbon aerosol loading for every 1‐mm increase in rainfall intensity over the study area. The scavenging coefficient of black carbon aerosols is found to be 1.64 × 10−5 s−1. © Crown Copyright 2005. Reproduced with the permission of Her Majesty's Stationery Office. Published by John Wiley & Sons, Ltd.
Modelling of downwelling long‐wave radiation using cloud fraction obtained from laser cloud‐base measurements
Authors: Rooney G. G.
Published: September 2005

A method is described for the estimation of downwelling long‐wave radiation in both cloudy and clear‐sky conditions. This method uses an estimate of cloud fraction, obtained from the output of a laser cloud‐base recorder, to modify the clear‐sky emissivity as calculated from standard near‐surface measurements. © Crown Copyright 2005. Reproduced with the permission of Her Majesty's Stationery Office. Published by John Wiley & Sons, Ltd.
Maternal nutritional programming of fetal adipose tissue development: Long‐term consequences for later obesity
Authors: Budge Helen , Gnanalingham Mo G. , Gardner David S. , Mostyn Alison , Stephenson Terence , Symonds Michael E.
Published: September 2005

As obesity reaches epidemic levels in the United States there is an urgent need to understand the developmental pathways leading to this condition. Obesity increases the risk of hypertension and diabetes, symptoms of which are being seen with increased incidence in children. Adipocyte development begins in the fetus and, in contrast to all other tissues whose growth ceases in late juvenile life, it has the capacity for “unlimited” growth. In normal healthy individuals, the increase in fat mass with age is accompanied by a parallel increase in cortisol sensitivity, i.e., increased glucocorticoid receptor abundance and increased activity of the enzyme 11β hydroxysteroid dehydrogenase type 1. Enhanced adipocyte sensitivity to cortisol is promoted in offspring born to mothers that were nutrient‐restricted in utero in conjunction with increased peroxisome proliferator activated receptor α. This adaptation only appears to be associated with greater fat mass in the offspring when maternal nutrient restriction is confined to late gestation, coincident with the period of maximal fetal growth. In these offspring, increased fat mass is accompanied by glucose intolerance and insulin resistance, in conjunction with an adipose tissue specific reduction in glucose transporter 4 abundance. In conclusion, changes in maternal and, therefore, fetal nutrient supply at specific stages of gestation have the potential to substantially increase the risk of those offspring becoming obese in later life. The extent to which changes in dietary habits, both during pregnancy and in later life, may act to contribute to the current explosion in childhood and adult obesity remains a scientific and public health challenge to us all. Birth Defects Research (Part C) 75:193–199, 2005. © 2005 Wiley‐Liss, Inc.
Vertebrate myotome development
Authors: Hollway Georgina , Currie Peter
Published: September 2005

The embryonic myotome generates both the axial musculature and the appendicular muscle of the fins and limbs. Early in embryo development the mesoderm is segmented into somites, and within these the primary myotome forms by a complex series of cellular movements and migrations. A new model of primary myotome formation in amniotes has emerged recently. The myotome also includes the muscle progenitor cells that are known to contribute to the secondary formation of the myotome. The adult myotome contains satellite cells that play an important role in adult muscle regeneration. Recent studies have shed light on how the growth and patterning of the myotome occurs. Birth Defects Research (Part C) 75:172–179, 2005. © 2005 Wiley‐Liss, Inc.
Transcriptional control of chondrocyte fate and differentiation
Authors: Lefebvre Véronique , Smits Patrick
Published: September 2005

Chondrogenesis is an essential process in vertebrates. It leads to the formation of cartilage growth plates, which drive body growth and have primary roles in endochondral ossification. It also leads to the formation of permanent cartilaginous tissues that provide major structural support in the articular joints and respiratory and auditory tracts throughout life. Defects in chondrogenesis cause chondrodysostoses and chondrodysplasias. These skeletal malformation diseases account for a significant proportion of birth defects in humans and can dramatically affect a person's expectancy and quality of life. Chondrogenesis occurs when pluripotent mesenchymal cells commit to the chondrocyte lineage, and through a series of differentiation steps build and eventually remodel cartilage. This review summarizes and discusses our current knowledge and lack of knowledge about the chondrocyte differentiation pathway, from mesenchymal cells to growth plate and articular chondrocytes, with a main focus on how it is controlled by tissue patterning and cell differentiation transcription factors, such as, but not limited to, Pax1 and Pax9, Nkx3.1 and Nkx3.2, Sox9, Sox5 and Sox6, Runx2 and Runx3, and c‐Maf. Birth Defects Research (Part C) 75:200–212, 2005. © 2005 Wiley‐Liss, Inc.
In vitro galactosylation of human IgG at 1 kg scale using recombinant galactosyltransferase
Authors: Warnock Dale , Bai Xiaomei , Autote Katie , Gonzales Johnny , Kinealy Kyle , Yan Boxu , Qian Jun , Stevenson Tom , Zopf David , Bayer Robert J.
Published: September 2005

The Fc effector functions of immunoglobulin G (IgG) antibodies are in part determined by structural features of carbohydrates linked to each of the paired gamma heavy chains in the antibody constant domain (CH2). One glycoform that has been shown to be advantageous is G2, where both arms of complex bi‐antennary N‐glycans terminate in galactose. In vitro treatment with glycosyltransferases can remodel heterogeneous IgG glycoforms, enabling preparation of IgG molecules with homogeneous glycan chains. Here we describe optimization of conditions for use of a soluble recombinant galactosyltransferase in vitro to remodel glycans of human serum IgG, and we demonstrate a scaled‐up reaction in which >98% of neutral glycans attached to 1 kg IgG are converted to the G2 glycoform. Removal of glycosylation reagents from the product is achieved in one step by affinity chromatography on immobilized Protein A. © 2005 Wiley Periodicals, Inc.
Transcriptional and metabolic response of recombinant Escherichia coli to spatial dissolved oxygen tension gradients simulated in a scale‐down system
Authors: Lara Alvaro R. , Leal Lidia , Flores Noemí , Gosset Guillermo , Bolívar Francisco , Ramírez Octavio T.
Published: September 2005

Escherichia coli, expressing recombinant green fluorescent protein (GFP), was subjected to dissolved oxygen tension (DOT) oscillations in a two‐compartment system for simulating gradients that can occur in large‐scale bioreactors. Cells were continuously circulated between the anaerobic (0% DOT) and aerobic (10% DOT) vessels of the scale‐down system to mimic an overall circulation time of 50 s, and a mean residence time in the anaerobic and aerobic compartments of 33 and 17 s, respectively. Transcription levels of mixed acid fermentation genes (ldhA, poxB, frdD, ackA, adhE, pflD, and fdhF), measured by quantitative RT‐PCR, increased between 1.5‐ to over 6‐fold under oscillatory DOT compared to aerobic cultures (constant 10% DOT). In addition, the transcription level of fumB increased whereas it decreased for sucA and sucB, suggesting that the tricarboxylic acid cycle was functioning as two open branches. Gene transcription levels revealed that cytrochrome bd, which has higher affinity to oxygen but lower energy efficiency, was preferred over cytochrome bO3 in oscillatory DOT cultures. Post‐transcriptional processing limited heterologous protein production in the scale‐down system, as inferred from similar gfp transcription but 19% lower GFP concentration compared to aerobic cultures. Simulated DOT gradients also affected the transcription of genes of the glyoxylate shunt (aceA), of global regulators of aerobic and anaerobic metabolism (fnr, arcA, and arcB), and other relevant genes (luxS, sodA, fumA, and sdhB). Transcriptional changes explained the observed alterations in overall stoichiometric and kinetic parameters, and production of ethanol and organic acids. Differences in transcription levels between aerobic and anaerobic compartments were also observed, indicating that E. coli can respond very fast to intermittent DOT conditions. The transcriptional responses of E. coli to DOT gradients reported here are useful for establishing rational scale‐up criteria and strain design strategies for improved culture performance at large scales. © 2005 Wiley Periodicals, Inc.
In situ measurement of bioluminescence and fluorescence in an integrated microbioreactor
Authors: Zanzotto Andrea , Boccazzi Paolo , Gorret Nathalie , Van Dyk Tina K. , Sinskey Anthony J. , Jensen Klavs F.
Published: September 2005

Reporter strains of bacteria that emit light or a fluorescent marker in response to specific conditions in their environment are having a significant impact in many areas of biology, including toxicity assays for environmental pollutants, chemical detection, and gene expression profiling. We have demonstrated methods for in situ measurements of bioluminescence and fluorescence from bacterial cultures grown in 50 µL instrumented microbioreactors. Results from microbioreactors were compared to results obtained from conventional 500 mL batch bioreactors and shake flasks. Experiments were conducted with reporter strains of Escherichia coli in which luxCDABE or gfp was fused to a promoter that was either expressed constitutively, or that responded to oxygen limitation. With these reporter strains, we have demonstrated the ability to obtain information on growth conditions within the microbioreactor. We have also shown that the large aspect ratio of the microbioreactor provides a unique advantage over measurements in larger bioreactors by reducing the inner filter effect in on‐line measurements and eliminating the need for error‐prone off‐line dilutions. In addition, continuous on‐line monitoring of genes in real‐time, when expanded to include entire reporter libraries, could potentially provide a true dynamic picture of cellular gene expression from which the kinetics of gene expression can be untangled and elucidated. © 2005 Wiley Periodicals, Inc.
Value of fluorodeoxyglucose positron emission tomography in women with breast cancer
Authors: Landheer M L E A , Steffens M G , Klinkenbijl J H G , Westenberg A H , Oyen W J G
Published: September 2005

Background

The aim of this prospective study was to evaluate the role of fluorodeoxyglucose positron emission tomography (FDG-PET) in the staging of high-risk women with primary or recurrent breast cancer.

Methods

FDG-PET was performed in 42 women with a primary breast cancer and unfavourable characteristics, or who had a suspected relapse. FDG-PET and conventional staging methods were compared. In case of abnormality on FDG-PET, confirmation was always attempted.

Results

Increased uptake was found in five of 17 women with a primary cancer. In the 25 women with a suspected relapse, FDG-PET showed increased uptake in 43 areas, 22 correctly confirming the area of suspected relapse and 21 indicating other sites of metastases. Compared with conventional imaging, FDG-PET revealed additional (confirmed) lesions in two women with primary cancers and three with relapse. Patient management was changed for five women.

Conclusion

FDG-PET is a sensitive diagnostic method for the detection of distant metastatic disease. Its exact role in women with breast cancer remains to be defined.
Coexistence of a Meckel's diverticulum and a urachal remnant
Authors: Özel L.Z. , Talu M. , User Y. , Aydin N. , Marur T.
Published: September 2005

Meckel's diverticulum, which is a remnant of the omphalomesenteric or vitelline duct, is the most common congenital abnormality of the gastrointestinal system. Urachal abnormalities, resulting from anomalous urogenital development, are not observed frequently and case reports are mainly represented in literature. The presence of these two congenital anomalies together is a very rare pathology. Complications arising from a Meckel's diverticulum or urachal remnant may clinically mimic acute appendicitis and other surgical pathologies. We report on a patient who underwent surgery for acute appendicitis when it was discovered that the symptoms were produced by a perforated Meckel's diverticulitis. In the course of the surgery, a urachal remnant was found to coexist with the diverticulum. Clin. Anat. 18:609–612, 2005. © 2005 Wiley‐Liss, Inc.
Superficial ulnar artery terminating in a normal ulnar artery
Authors: Mannan Ashim , Sarikcioglu Levent , Ghani Samuel , Hunter Alistair
Published: September 2005

Routine dissection of the left upper limb of an 86‐year‐old male cadaver showed a superficial ulnar artery that anastomosed with the ulnar artery. The superficial ulnar artery arose from the third part of the axillary artery, coursed distally over the flexor muscles of the forearm, and terminated by anastomosing with the ulnar artery in the distal third of the forearm. Arterial and neural variations were also observed on the contralateral side. The presence of a superficial ulnar artery is important clinically when raising forearm flaps in reconstructive surgery. Clin. Anat. 18:602–605, 2005. © 2005 Wiley‐Liss, Inc.
Clinical significance of suprascapular nerve mobilization
Authors: Bodily Kale D. , Spinner Robert J. , Shin Alexander Y. , Bishop Allen T.
Published: September 2005

The anatomy of the suprascapular nerve is important to surgeons when focal nerve lesions necessitate surgical repair. Recent experience with a patient who had a complete suprascapular nerve lesion in the retroclavicular region (combined with axillary and musculocutaneous nerve lesions) is presented to illustrate that successful direct nerve repair is possible despite resection of a neuroma. Specifically, we found that neurolysis and mobilization of the suprascapular nerve and release of the superior transverse scapular ligament provided the necessary nerve length to achieve direct nerve repair after the neuroma was removed. A combined supraclavicular and infraclavicular approach to the suprascapular nerve provided excellent visualization, especially in the retroclavicular region. Postoperatively, the patient recovered complete shoulder abduction and external rotation with the direct repair, an outcome uncommonly achieved with interpositional grafting. Based on our operative experience, we set out to quantify the length that the suprascapular nerve could be mobilized with neurolysis. Mobilization of the nerve and release of the superior transverse scapular ligament generated an average of 1.6 cm and 0.7 cm of extra nerve length respectively, totaling 2.3 cm of additional usable nerve length overall. The ability to expose the suprascapular nerve in the retroclavicular/infraclavicular region and to mobilize the suprascapular nerve for possible direct repair has not been previously emphasized and is clinically important. This surgical approach and technique permits direct nerve repair after resection of a focal neuroma in the retroclavicular or infraclavicular region, thus avoiding interpositional grafting, and improving outcomes. Clin. Anat. 18:573–579, 2005. © 2005 Wiley‐Liss, Inc.
Synthesis and Characterization of Heterometallic Clusters (Ir2Rh, Ir2W, Rh3) Containing 1,2‐Dicarba‐closo‐dodecaborane(12)‐1,2‐dithiolate Chelate Ligands, [(B10H10)C2S2]2−
Authors: Wang Jian‐Qiang , Cai Shuyi , Jin Guo‐Xin , Weng Lin‐Hong , Herberhold Max
Published: September 2005

The 16‐electron half‐sandwich complex [Cp*Ir{S2C2(B10H10)}] (Cp*=η5‐C5Me5) (1 a) reacts with [{Rh(cod)(μ‐Cl)}2] (cod=cycloocta‐1,5‐diene, C8H12) in different molar ratios to give three products, [{Cp*Ir[S2C2(B10H9)]}Rh(cod)] (2), trans‐[{Cp*Ir[S2C2(B10H9)]}Rh{[S2C2(B10H10)]IrCp*}] (3), and [Rh2(cod)2{(μ‐SH)(μ‐SC)(CH)(B10H10)}] (4). Complex 3 contains an Ir2Rh backbone with two different IrRh bonds (3.003(3) and 2.685(3) Å). The dinuclear complex 2 reacts with the mononuclear 16‐electron complex 1 a to give 3 in refluxing toluene. Reaction of 1 a with [W(CO)3(py)3] (py=C5H5N) in the presence of BF3⋅EtO2 leads to the trinuclear cluster [{Cp*Ir[S2C2(B10H10)]}2W(CO)2] (5) together with [{Cp*Ir(CO)[S2C2(B10H10)]}W(CO)5] (6), and [Cp*Ir(CO){S2C2(B10H10)}] (7). Analogous reactions of [Cp*Rh{S2C2(B10H10)}] (1 b) with [{Rh(cod)(μ‐Cl)}2] were investigated and two complexes cis‐[{Cp*Rh[S2C2(B10H10)]}2Rh] (8) and trans‐[{Cp*Rh[S2C2(B10H10)]}2Rh] (9) were obtained. In refluxing THF solution, the cisoid 8 is converted in more than 95 % yield to the transoid 9. All new complexes 2–9 were characterized by NMR spectroscopy (1H, 11B NMR) and X‐ray diffraction structural analyses are reported for complexes 2–5, 8, and 9.
Exploring and Exploiting the Therapeutic Potential of Glycoconjugates
Authors: Doores Katie J. , Gamblin David. P. , Davis Benjamin G.
Published: September 2005

Carbohydrates, either bound to proteins or in lipids, play essential roles as communication molecules in many intercellular and intracellular processes. In particular, carbohydrates are important mediators of cell–cell recognition events and have been implicated in related processes such as cell signaling regulation, cellular differentiation and immune response. This diverse utility has long suggested the power of carbohydrates in therapeutic approaches. This Concepts article highlights the recent potential uses of glycoconjugates as therapeutics, with particular reference to glycopeptides, glycoproteins, glycodendrimers, and glycoarrays.
Asymmetric Sulfonium Ylide Mediated Cyclopropanation: Stereocontrolled Synthesis of (+)‐LY354740
Authors: Aggarwal Varinder K. , Grange Emma
Published: September 2005

The reaction of ester‐stabilized sulfonium ylides with cyclopentenone to give (+)‐5 ((1S,5R,6S)‐ethyl 2‐oxobicyclo[3.1.0]hexane‐6‐carboxylate), an important precursor to the pharmacologically important compound (+)‐LY354740, has been studied using chiral sulfides operating in both catalytic (sulfide, Cu(acac)2, ethyl diazoacetate, 60 °C) and stoichiometric modes (sulfonium salt, base, room temperature). It was found that the reaction conditions employed had a major influence over both diastereo‐ and enantioselectivity. Under catalytic conditions, good enantioselectivity with low diastereoselectivity was observed, but under stoichiometric conditions low enantioselectivity with high diastereoselectivity was observed. When the stoichiometric reactions were conducted at high dilution, diastereoselectivity was reduced. This indicated that base‐mediated betaine equilibration was occurring (which is slow relative to ring closure at high dilution). Based on this model, conditions for achieving high enantioselectivity were established as follows: use of a preformed ylide, absence of base, hindered ester (to reduce ylide‐mediated betaine equilibration), and low concentration. Under these conditions high enantioselectivity (95 % ee) was achieved, albeit with low diastereocontrol. Our model for selectivity has been applied to other sulfonium ylide mediated cyclopropanation reactions and successfully accounts for the diastereoselectivity observed in all such reported reactions to date.
Bifunctional‐Thiourea‐Catalyzed Diastereo‐ and Enantioselective Aza‐Henry Reaction
Authors: Xu Xuenong , Furukawa Tomihiro , Okino Tomotaka , Miyabe Hideto , Takemoto Yoshiji
Published: September 2005

Bifunctional thiourea 1 a catalyzes aza‐Henry reaction of nitroalkanes with N‐Boc‐imines to give syn‐β‐nitroamines with good to high diastereo‐ and enantioselectivity. Apart from the catalyst, the reaction requires no additional reagents such as a Lewis acid or a Lewis base. The N‐protecting groups of the imines have a determining effect on the chirality of the products, that is, the reaction of N‐Boc‐imines gives R adducts as major products, whereas the same reaction of N‐phosphonoylimines furnishes the corresponding S adducts. Various types of nitroalkanes bearing aryl, alcohol, ether, and ester groups can be used as nucleophiles, providing access to a wide range of useful chiral building blocks in good yield and high enantiomeric excess. Synthetic versatility of the addition products is demonstrated by the transformation to chiral piperidine derivatives such as CP‐99,994.
Cover Picture: When are Two Waters Worse Than One? Doubling the Hydration Number of a Gd–DTPA Derivative Decreases Relaxivity (Chem. Eur. J. 20/2005)
Authors: Caravan Peter , Amedio John C. , Dunham Stephen U. , Greenfield Matthew T. , Cloutier Normand J. , McDermid Sarah A. , Spiller Marga , Zech Stephan G. , Looby Richard J. , Raitsimring Arnold M. , McMurry Thomas J. , Lauffer Randall B.
Published: September 2005

MRI contrast agents act by relaxing water protons. When an acetate group on the MRI angiography contrast agent MS‐325 is replaced with a methyl group, it opens up a coordination site for a second water ligand. The additional water is expected to improve the relaxivity of the new complex, and this is observed in buffer solution. However, in the presence of the plasma protein serum albumin the relaxivity is only about half that of MS‐325, making the new compound less attractive for blood vessel imaging. On page 5866 ff., P. Caravan et al. describe the synthesis of this novel gadolinium complex and report mechanistic studies indicating that slow water exchange limits relaxivity. The artwork was created by Vincent Jacques.
Growth of tin oxide nanocrystals
Authors: Zanotti L. , Zha M. , Calestani D. , Comini E. , Sberveglieri G.
Published: September 2005

Functional oxides are presently much investigated as regards not only their basic properties, but also their actual and potential applications. Tin oxides appear particularly interesting when grown in nanowire shape (SnO2‐NW) because of their electronic‐ and sensor‐device applications. In this paper the results of a systematic study on nucleation and growth of SnO2‐NWs, when an open‐tube vapor‐transport technique is employed, are reported and discussed. The vapor transport conditions have been investigated in greater detail and for the first time a growth model is proposed. Functional tests at different temperatures and gaseous compositions have proved that the SnO2‐NW are suitable for the preparation of highly‐sensitive and stable gas sensors. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Morphological, structural and optical study of quasi‐1D SnO2 nanowires and nanobelts
Authors: Calestani D. , Lazzarini L. , Salviati G. , Zha M.
Published: September 2005

0.1–0.3 mm thick entanglements of quasi‐one‐dimensional semiconducting Tin dioxide nanocrystals, in form of nanowires and nanobelts, are successfully grown by low cost Chemical Vapour Deposition directly on large area (100 mm2) Al2O3, SiO2 and Si substrates. Their lateral size ranges from 50 to 700 nm and their length can achieve several hundreds of micrometers. Transmission Electron Microscopy reveals either the nanowires and the nanobelts grow in the tetragonal Rutile structure. Diffraction contrast analyses and selected area diffraction investigations show the nanowires are single crystals without defects while the nanobelts sometimes present twins inside. An almost cylindrical shape and an average diameter of about 30–50 nm for the smallest nanowires is reported. X‐ray diffraction investigations exclude the presence of spurious phases. A broad band structured in two emissions peaked at about 450 nm and 560 nm is revealed by large area Cathotoluminescence, while single nanocrystal spectroscopy shows that the reduction of the lateral dimension of the nanobelts from 1000 nm to 50 nm blue‐shifts the main emission band at 560 nm of about 40 nm (at room temperature). These preliminary results suggest a possible role of oxygen vacancies and of the surface/volume ratio on the origin and the blue shift of Cathodoluminescence spectra. The near band edge emission, typical of bulk tin dioxide (∼320 nm), is not found in nanobelts narrower than 1000 nm. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Spontaneous ordering of self‐assembled‐Ge island
Authors: De Seta M. , Capellini G. , Evangelisti F.
Published: September 2005

Self‐assembled quantum dots can be the building blocks of a variety of mesoscopic devices. However, in order to use these structures in large‐scale integrated devices, accurate control over their spatial positioning is required. We show here that, by a suitable engineering of the deposition process, it is possible to obtain self‐organization resulting in well ordered clusters composed of regularly disposed nano‐sized islands. Elastically relaxed Ge islands act as a stressor for a Si layer subsequently deposited (Ge has a 4% larger lattice cell). This effect results in a modulation of the lattice parameter and strain field in the Si over‐layer. In particular the Si lattice in the columnar region on top of the buried islands is tensile strained and will act as preferential nucleation site for the subsequent Ge island growth. We have generated a square array of tensile‐strained regions oriented along the [010]‐[100] directions on the Si(001) surface exploiting the self‐ordering occurring in the growth at 750 °C of Ge island multi‐layers used as a template. The strain field intensity and shape was modified by changing the thickness of the template Si over‐layer: the thicker the overlayer the wider and less intense the strain field in the Si tensile regions. On this template we have grown a Ge island layer at the lower temperature of 600 °C. At this growth temperature the islands are much smaller than the lateral extension of the strain field on the Si surface of the template and the nucleation and evolution of several islands inside a single tensile‐strained regions is promoted. Upon decreasing the template Si over‐layer thickness from 200 to 35 nm the Ge island spatial distribution changes from random to a well‐ordered square lattice of multi‐island clusters. At intermediate Si over‐layer thickness (65 nm), the Ge islands are confined in cluster regions only at the first stage of their evolution (pyramids), while for thinner over‐layer (35 nm) islands are assembled in clusters up to the last stage their growth dynamics (relaxed domes). The strong dome‐to‐dome interaction within a cluster, due to their small mutual separation, has impact also on the dome size by reducing their mean base width of about 35%. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Formation of II‐VI nanocrystals in polymeric matrix: Thermolytic synthesis and structural characterization
Authors: Antolini F. , Di Luccio T. , Re M. , Tapfer L.
Published: September 2005

In this work we report on the growth of CdS and ZnS semiconductor nanocrystals embedded in a polymeric matrix (polystyrene) by synthesizing a metal thiolate precursor and its subsequent thermolysis at about 300 °C after dispersion in the polymer. The crystallinity, shape and size of the metal sulfide nanocrystals were investigated by x‐ray diffraction and transmission electron microscopy. The microstructural analysis demonstrates that our synthesis procedure allows us to control the nanocrystal growth in order to form nanoparticles with diameter as small as Ø = 2 nm. In particular, XRD analysis reveals that only CdS and ZnS nanocrystals of zincblende structure are formed. TEM images show that the metal sulfide nanocrystals are monocrystals of spherical shape and the size dispersion is <20%. Our experiments indicate that the nanocrystal capping agent is performed by the sulfur atoms at the surface of the nanoparticle bound to alkyl chain of the thiolate. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Growth, morphological and structural characterization of silicon carbide epilayers for power electronic devices applications
Authors: Pirri C. F. , Porro S. , Ferrero S. , Celasco E. , Guastella S. , Scaltrito L. , Yakimova R. , Syväjärvi M. , Ciechonski R. R. , De Angelis S. , Crippa D.
Published: September 2005

Silicon carbide (SiC) is a wide band gap semiconductor, interesting for its physical properties such as high breakdown field, high saturated drift velocity and high thermal conductivity, which has been intensively studied in the last years. Although the high potentiality of this material, the SiC technology shows at the moment some limitations, indeed, the reliability of SiC‐based devices is strictly correlated to the defects present in the crystalline structure. 4H‐SiC epilayers were grown by Hot Wall Chemical Vapor Deposition (at 1600 °C) and by Sublimation techniques (at 2000 °C). A surface investigation of the epilayers has been performed finding particular physical finger‐prints correlated with several kind of defects aimed at giving an important feedback to the epitaxial growth processes. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Horizontal hot wall reactor design for epi‐SiC growth
Authors: Veneroni A. , Omarini F. , Masi M. , Leone S. , Mauceri M. , Pistone G. , Abbondanza G.
Published: September 2005

The model adopted for the simulation of a new industrial size type of horizontal cold wall reactor for epitaxial silicon carbide deposition is reviewed. The attention is focalized on the chemical mechanism adopted and on the comparison with some growth rate data and temperature profiles for the system ethylene, silane, hydrogen and the deposition of undoped silicon carbide. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Thermodynamical analysis of abrupt interfaces of InGaP/GaAs and GaAs/InGaP heterostructures
Authors: Pelosi C. , Attolini G. , Bosi M. , Frigeri C. , Bersani M. , Giubertoni D. , Vanzetti L. , Musayeva N.
Published: September 2005

Interfaces between arsenide and phosphide III‐V semiconductors have shown to be one of the most difficult issues to be understood and definitively solved. This problem is particularly relevant with Vapour Phase Epitaxy (VPE) and Metallo‐Organic Vapour Phase Epitaxy (MOVPE) techniques, since an irreproducibility in preparing abrupt interfaces between arsenide and phosphide has been evidenced. Several researchers have ascribed this problem to the volatility of arsenic and phosphorus species and since then for long time different recipes and growth procedures have been suggested in order to obtain sharp transition between the two different materials. In this work the film/substrate interface is modelled using thermodynamical calculations after the regular solution model proposed by Jordan and Ilegems: PH3 flows over GaAs surface, and as a consequence the substrate is enriched with P, with the formation of a thin layer of GaAsP and mixed As‐P gaseous species. Samples of InGaP on GaAs substrate were grown by MOVPE and characterised by Secondary Ion Mass Spectroscopy (SIMS) and Transmission Electron Microscopy (TEM) in order to support the theoretical findings. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Homoepitaxy of ZnTe on (100) oriented substrates: Technology issues and MOVPE growth aspects
Authors: Traversa M. , Lovergine N. , Prete P. , Tapfer L. , Mancini A. M.
Published: September 2005

The metalorganic vapour phase epitaxy of ZnTe on single crystal (100)ZnTe:P wafers is reported. The technological steps to prepare a substrate surface suitable for the high quality homoepitaxy of ZnTe are identified and optimised in terms of structural and morphological properties of overgrown epilayers. Removal of ∼7 µm of material from the ZnTe:P wafers by chemical etching in 1% Br2‐methanol solution proved necessary to achieve a sufficiently smooth and homogeneous surface; in‐situ H2 heat treatment of the wafers at 350°C immediately before growth ensures optimal desorption of residual oxides, allowing epilayer crystalline quality comparable to the substrate. However, the structure of epilayers degrades for growth temperatures (TG) above 350 °C due to the occurrence of stacking faults (SFs) within ∼200‐300 nm from the epilayer‐substrate interface. Accordingly, the epilayer band‐edge luminescence vanishes below 350 nm, indicating a worsening of the material radiative efficiency in very thin epilayers. The epilayer surface morphology is the result of a complex interplay between SF nucleation and Te:Zn ad‐atom stoichiometry during growth. Almost featureless morphologies are obtained for growth at 350 °C, i.e. under nearly stoichiometric surface conditions. Pyramid‐like hillocks develop instead for TG ≥ 360 °C, corresponding to Te‐rich surface conditions, their density rapidly increasing up to around 9 × 106 cm–2 at TG = 400 °C. Hillocks occur in close pairs on the epilayer surface, their nucleation being strongly reduced if a thin ZnTe buffer layer is grown at low (325 °C) temperature, i.e. if SFs do not occur at the epilayer‐substrate interface. This demonstrates that hillocks form as a result of three‐dimensional growth around partial dislocations pairs bounding SFs, the phenomenon being driven by Te ad‐atoms experiencing a Schwoebel potential barrier at the surface step edges around the dislocations. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)