bluuebunny/crossref_metadata_2025_split huggingface dataset:
Common Variants in Maturity-Onset Diabetes of the Young Genes and Future Risk of Type 2 Diabetes
Authors: Holmkvist Johan , Almgren Peter , Lyssenko Valeriya , Lindgren Cecilia M. , Eriksson Karl-Fredrik , Isomaa Bo , Tuomi Tiinamaija , Nilsson Peter , Groop Leif 
Published: March 2008

OBJECTIVE—Mutations in the hepatocyte nuclear factor (HNF)-1α, HNF-4α, glucokinase (GCK), and HNF-1β genes cause maturity-onset diabetes of the young (MODY), but it is not known whether common variants in these genes predict future type 2 diabetes.
RESEARCH DESIGN AND METHODS—We tested 14 previously associated polymorphisms in HNF-1α, HNF-4α, GCK, and HNF-1β for association with type 2 diabetes–related traits and future risk of type 2 diabetes in 2,293 individuals from the Botnia study (Finland) and in 15,538 individuals from the Malmö Preventive Project (Sweden) with a total follow-up &gt;360,000 years.
RESULTS—The polymorphism rs1169288 in HNF-1α strongly predicted future type 2 diabetes (hazard ratio [HR] 1.2, P = 0.0002). Also, SNPs rs4810424 and rs3212198 in HNF-4α nominally predicted future type 2 diabetes (HR 1.3 [95% CI 1.0–1.6], P = 0.03; and 1.1 [1.0–1.2], P = 0.04). The rs2144908 polymorphism in HNF-4α was associated with elevated rate of hepatic glucose production during a hyperinsulinemic-euglycemic clamp (P = 0.03) but not with deterioration of insulin secretion over time. The SNP rs1799884 in the GCK promoter was associated with elevated fasting plasma glucose (fPG) concentrations that remained unchanged during the follow-up period (P = 0.4; SE 0.004 [−0.003–0.007]) but did not predict future type 2 diabetes (HR 0.9 [0.8–1.0], P = 0.1). Polymorphisms in HNF-1β (transcription factor 2 [TCF2]) did not significantly influence insulin or glucose values nor did they predict future type 2 diabetes.
CONCLUSIONS—In conclusion, genetic variation in both HNF-1α and HNF-4α predict future type 2 diabetes, whereas variation in the GCK promoter results in a sustained but subtle elevation of fPG that is not sufficient to increase risk for future type 2 diabetes.
Central Nervous System Neuropeptide Y Signaling Modulates VLDL Triglyceride Secretion
Authors: Stafford John M. , Yu Fang , Printz Richard , Hasty Alyssa H. , Swift Larry L. , Niswender Kevin D. 
Published: March 2008

OBJECTIVE—Elevated triglyceride (TG) is the major plasma lipid abnormality in obese and diabetic patients and contributes to cardiovascular morbidity in these disorders. We sought to identify novel mechanisms leading to hypertriglyceridemia. Resistance to negative feedback signals from adipose tissue in key central nervous system (CNS) energy homeostatic circuits contributes to the development of obesity. Because triglycerides both represent the largest energy depot in the body and are elevated in both the plasma and adipose in obesity and diabetes, we hypothesized that the same neural circuits that regulate energy balance also regulate the secretion of TGs into plasma.
RESEARCH DESIGN AND METHODS—In normal fasting rats, the TG secretion rate was estimated by serial blood sampling after intravascular tyloxapol pretreatment. Neuropeptide Y (NPY) signaling in the CNS was modulated by intracerebroventricular injection of NPY, receptor antagonist, and receptor agonist.
RESULTS—A single intracerebroventricular injection of NPY increased TG secretion by 2.5-fold in the absence of food intake, and this was determined to be VLDL by fast performance liquid chromatography (FPLC). This effect was recapitulated by activating NPY signaling in downstream neurons with an NPY-Y5 receptor agonist. An NPY-Y1 receptor antagonist decreased the elevated TGs in the form of VLDL secretion rate by 50% compared with vehicle. Increased TG secretion was due to increased secretion of VLDL particles, rather than secretion of larger particles, because apolipoprotein B100 was elevated in FPLC fractions corresponding to VLDL.
CONCLUSIONS—We find that a key neuropeptide system involved in energy homeostasis in the CNS exerts control over VLDL-TG secretion into the bloodstream.
Haptoglobin Genotype
Authors: Costacou Tina , Ferrell Robert E. , Orchard Trevor J. 
Published: March 2008

OBJECTIVE—Haptoglobin is a plasma protein that binds free hemoglobin, thereby inhibiting hemoglobin-induced oxidative damage. We investigated the association between the haptoglobin genotype and the incidence of coronary artery disease (CAD) in a cohort of individuals with childhood-onset type 1 diabetes.
RESEARCH DESIGN AND METHODS—Participants from the Epidemiology of Diabetes Complications Study who were free of CAD at study entry and had DNA available were selected (n = 453, mean age 27.1 years, and diabetes duration 18.8 years). CAD was defined as angina, ischemic electrocardiogram, myocardial infarction confirmed by Q-waves on electrocardiogram or hospital records, angiographic stenosis &gt;50%, or revascularization.
RESULTS—The proportions of the cohort with the haptoglobin 1/1, 2/1, and 2/2 genotypes were 11.5, 41.3, and 47.2%, respectively. During 18 years of follow-up, there were 135 (29.8%) incident CAD events. Univariately, the proportion of CAD events increased from 15.4 to 28.3 and 34.6% for haptoglobin 1/1, 2/1, and 2/2, respectively (P = 0.02, P-trend = 0.007). Cumulative incidence (including 33 baseline prevalent cases) also increased from 24.1 to 32.3 and 39.1%, respectively (P = 0.07, P-trend = 0.02). In Cox proportional hazards models adjusting for traditional CAD risk factors, the haptoglobin 2/2 genotype was associated with increased CAD incidence compared with the haptoglobin 1/1 genotype (hazard ratio [HR] 2.21, 95% CI 1.05–4.65, P = 0.04). Although the risk associated with the haptoglobin 2/1 genotype did not reach significance (1.78, 0.84–3.79, P = 0.13), there remained a significant trend across the three groups (P = 0.03).
CONCLUSIONS—These data support the hypothesis that the haptoglobin genotype influences cardiovascular risk in type 1 diabetes.
Study of thin film structure based on MgF2, CeO2 and Al2O3 layers for optical applications
Authors: Asghar M. H. , Shoaib M. , Naseem S. , Placido F. 
Published: March 2008

Abstract
Thin film multilayer structures based on MgF2, CeO2 and Al2O3 layers were prepared on a BK7 glass substrate with resistive heating evaporation as an antireflection coating in the 450–750 nm spectral range. Prior to deposition of the multilayer structure, individual layers of the materials used were characterized. A three-layer structure of MgF2/CeO2/Al2O3/BK7 was then prepared using the same deposition conditions as for individual layers. Reasonably low reflection was observed for the as-deposited sample with R < 0.8% from 500–750 nm and R
ave < 1% over the desired spectrum. Further, low surface roughness and small particle size were seen for the as-deposited sample. Only a few low intensity peaks for the materials were observed with X-ray diffraction. Optical and structural properties were studied as a function of annealing temperature in the range 250°C–450°C. A slight shift of reflection spectra was observed with annealing, however, an increase in particle size (35 nm–70 nm) along with surface roughness was also observed.
Effect of Cr and V on phase equilibria in Co–WC based hardmetals
Authors: Frisk Karin , Markström Andreas 
Published: March 2008

Abstract
New measurements of the influence of Cr and V on the melting temperature of the binder phase in Co-based hardmetals are presented. It was shown that both Cr and V affect the melting temperature significantly. Cr decreases the melting temperature by over 100°C, and V by approximately 40°C. This is due to the high solubility of Cr and V in liquid Co, and this solubility was determined by experiments and calculations. The solubility of Cr in solid fcc-Co is also discussed, as well as the composition of the MC, M7C3 and the M6C carbides in alloys with Cr and V. The new experimental information is used to obtain a reliable thermodynamic description of the binder phase (Co-rich) in C – Co – Cr – W and C – Co – V – W alloys. Calculated equilibria are compared with experiments.
Influence of previous ageing treatments on the strength of an Al-4.3 wt.% Mg-1.2 wt.% Cu alloy processed by ECAE
Authors: Zhang Zheng-Rong , Van Houtte Paul , Verlinden Bert 
Published: March 2008

Abstract
The interaction of equal channel angular extrusion (ECAE) with precipitation hardening during warm ECAE at 180°C in a Al-4.3 wt.% Mg-1.2 wt.% Cu alloy, annealed at various stages of ageing, was studied by room temperature compression tests and transmission electron microscopy. It was observed that peak aged samples lose much of their strength during ECAE due to fragmentation of precipitates. The highest strength after four ECAE passes (route Bc) at 180°C is obtained with samples in the under-aged condition although in this case dissolution of precipitates into the matrix occurs. After four ECAE passes fine equiaxed grains with an average size of approximately 200 nm with some traces of remnant elongated grains were obtained.
Initial stage of bi-modal microstructure in TiO2-doped α-Al2O3 ceramics induced by SiO2 impurity
Authors: Qian Pengxiang , Gu Hui , Aldinger Fritz 
Published: March 2008

Abstract
Uni-modal and bi-modal microstructures were concurrently observed in a TiO2-doped -Al2O3 ceramic material with some SiO2 impurity. The segregation of Ti and Si to grain boundaries was systematically evaluated to reveal their role at the start of anisotropic grain growth. In general, in the bi-modal area grain boundaries exhibit higher Si excess than those in the uni-modal area. However, the basal plane of anisotropic grains was always found to contain more segregated Si while the non-basal planes were found to contain less Si. Such enrichment of SiO2 was also found at the basal planes of equiaxed grains in the uni-modal area, which occurred in the initial stage of anisotropic grain growth. Before and after this stage, the grain boundary composition was relatively uniform with the mole ratio of SiO2 to TiO2 as 2.3: 1 and 5.8: 1, respectively. The latter should be related to the composition of eutectic liquid formed during the sintering, which is responsible for the development of the bi-modal microstructure.
High‐Energy Electron Diffraction
Authors: Zuo Jian‐Min 
Published: March 2008

Abstract
High‐energy electrons have very short wavelengths associated with particle waves and electron diffraction is used to probe the atomic structure of both inorganic and organic materials. Electrons have a large scattering cross section and can be focused into small probes by magnetic lenses. This makes electron diffraction very useful for studying “small” crystals, surfaces, or material's microstructure. The principles and the modern aspects of electron diffraction are described here with the intention to provide an introduction that both the novice and the expert will find useful as a guide for electron diffraction. The chapter starts with an introduction to different electron diffraction techniques. This is followed by the background theories which are useful for the interpretation of diffraction patterns. Experimental procedures are described at the end of the technical background. The applications section has a large collection of examples from relatively straightforward tasks to more advanced ones that are under development for their promises. Experimental details are provided when it is appropriate to give some idea of what it takes to do electron diffraction.
High Resolution Electron Energy‐Loss Spectroscopy
Authors: Soriaga Manuel P. , Chen Xiaole , Li Ding , Stickney John L. 
Published: March 2008

Abstract
The determination of the identity and structure of molecular species present in no more than monolayer quantities at solid surfaces is one of the more difficult tasks in interfacial science. In this regard, vibrational spectroscopy is an invaluable technique; in the evaluation of the molecular integrity of surface‐bound compounds, it has few equals. Optical methods such as infrared spectroscopy, while rather uncomplicated for bulk materials, lack the high sensitivity needed for most surface species due to minuscule molecular amounts. A much more responsive alternative is based on the use of low‐energy electrons to interact with the molecular oscillators on the surface. If inelastic interactions occur, the energy of the backscattered electrons will be lower than that of the incident electrons, and the energy loss will correspond to a vibrational‐mode frequency. The present article briefly describes the fundamental principles of and instrumental considerations in high‐resolution electron energy‐loss spectroscopy (HREELS), and cites seminal applications in the study of the adsorption of organic and inorganic molecules at metal and semiconductor surfaces. A limited list of HREELS work published since the turn of the century is added in the last section.
Microwave Rotational Spectroscopy
Authors: Xu Yunjie , Jäger Wolfgang 
Published: March 2008

AbstractSince its inception in 1934, microwave rotational spectroscopy has provided some of the most accurate data for numerous small to medium sized molecules, including structural parameters, force field parameters, and electronic charge distributions. We give a very brief review of the history of microwave spectroscopy, leading up to the most recent developments, that is, instruments that use Fourier transform techniques. Since these Fourier transform microwave spectrometers are not commercially available, a brief discussion about their general design is given. Analyses of the recorded rotational spectra can yield a number of spectroscopic parameters, depending on the molecular symmetry and the various angular momenta present, such as nuclear spins and electronic momenta. The physical significance of the more common spectroscopic parameters, such as rotational constants, centrifugal distortion constants, nuclear quadrupole coupling constants, etc. is given. We also indicate how these parameters can be used to characterize the molecule in terms of, for example, structural parameters, dynamical behavior, and bond character. The remainder of the article is devoted to case studies. These include the discovery of covalent bonds involving the noble gas atom argon, structural characterization of organometallic compounds, such as ferrocenes, bonding in diatomic transition metal‐containing compounds, a description of laboratory studies of molecules which are of atmospheric and astrophysical interest, and studies of weakly bound complexes with relevance to inorganic chemistry.
Nuclear Resonance Vibrational Spectroscopy (
NRVS
)
Authors: Zeng Weiqiao , Silvernail Nathan J. , Scheidt W. Robert , Sage J. Timothy 
Published: March 2008

Abstract
Nuclear Resonance Vibrational Spectroscopy (NRVS) utilizes the simultaneous excitation of the Mössbauer nucleus and vibrational quanta. Vibrational features appear as sidebands on the recoilless resonance. NRVS reveals the complete vibrational spectrum of the probe nucleus with the resolution almost equal to that of Raman or infrared. Major advantages include selectivity to vibrations of the Mössbauer isotope with quantitative information on vibrational amplitudes, as well as frequencies. Single crystal measurements are selective for motion along the exciting X‐ray beam. NRVS is equally applicable to all ligation and oxidation states. Questions that can be addressed include the strength of metal coordination, the energetic cost of probe displacement, discrimination of metal‐ligand vibrations from cofactor or peptide vibrations, and the local vs. global character of active site vibrations.
Photoelectron Spectroscopy
Authors: Gruhn Nadine E. , Lichtenberger Dennis L. 
Published: March 2008

Abstract
Photoelectron spectroscopy measures the energies for emission of electrons from molecules or materials through application of the photoelectric effect. For neutral molecules this is a direct measure of the ionization energies. The ionizations are explicitly defined in terms of transitions between the ground state of a molecule and accessible states of the molecular positive ion, but in a first order approximation, each ionization of a molecule can be described as removal of an electron from an individual orbital. The ionization energies can then be considered as measures of orbital energies, and shifts can be interpreted in terms of orbital stabilizations or destabilizations due to changes in electron distributions and bonding. The intensities and profiles of the ionization bands in the photoelectron spectra provide additional information on the characters and bonding natures of the orbitals. All orbitals can be probed, from valence orbitals such as lone pairs and bonds to orbitals in the cores of heavy atoms. Photoelectron spectroscopy is a large field of study that has many subfields and new techniques continue to be introduced. These different subfields all have different instrumental and sample constraints, but taken as a whole photoelectron spectroscopic experiments can be performed on almost any system of interest in inorganic chemistry. This article summarizes the basic physical principles of photoelectron emission caused by one or more photons, the relationship of photoelectron spectra to the electronic structure of neutral and anionic molecules, and the additional considerations for photoionization of bulk samples. Auger electron spectroscopy (AES) and Penning ionization electron spectroscopy (PIES), techniques which are closely related to photoelectron spectroscopy, are also discussed. Case studies are given for applications of photoelectron spectroscopy to study of bioinorganic model complexes, including iron‐sulfur and molybdenum‐sulfur bonding and covalency, electronic structure of porphyrins and metalloporphyrins, negative‐ion photoelectron spectroscopy of phthalocyanines, and the use of the technique to measure inner‐sphere reorganization energies.
Photoluminescence and Electroluminescence, Solid State
Authors: Deye Joel R. , Walters Keith A. 
Published: March 2008

Abstract
The measurement of photoluminescence or electroluminescence on solid samples can provide details on the electronic nature of the material in question. The majority of these measurements involve the examination of the electronic structure of semiconductors, especially those under consideration for use as light‐emitting diodes or photoelectric cells. The presence of defects in these materials (in the form of excitons and acceptor/donor centers) can dramatically alter the observed spectral properties. However, the technique is largely limited to electronic profiling, so significant structural information and sample morphology must be probed with complementary techniques. Basic instrumentation and techniques for recording these spectra are presented, along with special considerations for solid‐state samples. Numerous examples of recent literature reports utilizing this technique are also presented.
Electronic Spectroscopy
Authors: Hughes Joseph L. , Krausz Elmars 
Published: March 2008

AbstractDevelopments in the ability of electronic spectroscopy to provide insights into the fundamental electronic structure, photophysical and/or photochemical processes in inorganic and bioinorganic systems are outlined. These are highlighted by a number of examples across a range of chemical and biochemical systems. Some fundamental constraints regarding the application of electronic spectroscopy to a wider range of chemical questions are identified, as well as both practical and intrinsic limitations associated with the processes of measurement. The ubiquitous phenomenon of spectral broadening in optical and UV spectroscopy is given particular attention and the important concept of homogeneous versus inhomogeneous broadening is highlighted. The overall focus is on absorption‐based spectroscopies of chromophores at variable and low temperatures in either glassy, crystalline, or protein environments. The utilization of some of the powerful emerging technologies such as tuneable laser sources or synchrotron sources, along with the very high efficiency charge coupled device (CCD) and semiconductor diode detectors that are now available, allows the rapid accumulation of high quality spectra of small samples as well as measurements in minimal actinic fluences.
Electron‐Nuclear Double Resonance (
ENDOR
) Spectroscopy
Authors: Telser Joshua 
Published: March 2008

Abstract

Electron‐nuclear double resonance (ENDOR) spectroscopy is a magnetic resonance technique that was invented in the mid 1950s by George Feher, then at Bell Telephone Laboratories. The first applications of ENDOR were to problems in solid state physics, but beginning in the 1970s, and particularly since the late 1980s, ENDOR has been widely applied to bioinorganic systems. ENDOR is fundamentally an electron paramagnetic resonance (EPR) technique, however, it also has aspects of nuclear magnetic resonance (NMR) spectroscopy. Essentially, ENDOR consists of the monitoring of an EPR signal, while effecting NMR transitions. The EPR signal can be either a continuous wave (CW) signal or a pulsed, electron spin echo (ESE) signal, in both cases caused by the application of microwave energy to a sample in an external magnetic field. As with EPR itself, ENDOR can thus be either a CW or pulsed (time‐domain) spectroscopic technique. The NMR transitions are caused by the application of radiofrequency (rf) energy, as with NMR itself. NMR transitions only of nuclei magnetically (hyperfine) coupled to the paramagnetic center (i.e., the center giving rise to the EPR signal) affect the intensity of this EPR signal, whether CW or pulsed, and provide characteristic ENDOR spectra. As a consequence of its double resonance nature, ENDOR has a great deal of flexibility in spectroscopic parameters. The parameters that affect EPR signals, e.g., microwave power, can also play a role in ENDOR spectral appearance. Additionally, there are parameters relevant to the NMR aspects of ENDOR that affect ENDOR spectra. In both CW and pulsed ENDOR there is experimental flexibility, which is described here. As a result, ENDOR spectroscopy can provide detailed information on multiple, magnetically active nuclei that comprise a paramagnetic center in a bioinorganic system. This information includes identification of such nuclei and metrical information on their relation to the paramagnetic center. This article uses a multifaceted case study to illustrate the application of ENDOR spectroscopy in bioinorganic chemistry. Specifically, the case study describes the application of multinuclear (
1, 2
H,
13
C,
57
Fe,
95
Mo) CW and pulsed ENDOR to enhance our understanding of the iron–molybdenum cofactor in nitrogenase. ENDOR allows identification of the constituent metal ions and their formal oxidation states, and identifies the nature of the substrate analog or inhibitor binding to the cluster. In combination with resting state structural information, and computational and model system studies, ENDOR can provide a structural picture of the intermediates in nitrogen fixation.