bluuebunny/crossref_metadata_2025_split huggingface dataset:
Electron Microscopy, Nanoscopy, and Scanning Micro‐ and NanoanalysisUpdate based on the original article by Vladimir Oleshko, Renaat Gijbels and Severin Amelinckx,Encyclopedia of Analytical Chemistry, © 2000, John Wiley & Sons, Ltd
Authors: Oleshko Vladimir P. , Gijbels Renaat , Amelinckx Severin 
Published: March 2013

AbstractThe article considers the history and stages of development of electron microscopy (EM) and scanning microanalysis, including theoretical aspects of electron beam–solid interactions, instrumentation, methodology of particular techniques and image analysis, sample preparation, and some typical applications as well. Major classes of EM techniques, i.e. stationary beam (transmission) and scanning beam EM methods, analytical electron microscopy (AEM), in situ EM, holography, and tomography are overviewed. In AEM, several imaging, diffraction, and analytical modes are integrated in a design to provide analytical synergism having obvious advantages over any single instrument. The subject of EM is to determine the morphology, crystallinity, defect structure, phase and elemental compositions, and electronic properties of a material using the focused electron beam and signals generated in the course of its interaction with the specimen. Various electron–specimen interactions generate a great deal of structural and analytical information in the form of emitted electrons and/or photons and internally produced signals, such as elastically and inelastically scattered electrons, Auger electrons (AEs), X‐rays, and cathodoluminescence (CL), which can be analyzed in different operating modes. Imaging of solid materials is essentially due to elastic scattering (diffraction) of electrons by the periodic arrangement of atoms in crystals (diffraction contrast) and/or interference of several diffracted and transmitted beams (phase contrast). High‐resolution imaging in scanning transmission mode is possible by using incoherently scattered electrons (Z‐contrast). Inelastic interactions form the basis for all chemical analytical techniques (energy‐dispersive (EDS) and wavelength‐dispersive (WDS) X‐ray spectroscopy, electron energy‐loss spectroscopy (EELS) energy‐filtering transmission electron microscopy (EFTEM), AE‐, and CL‐spectroscopy). The introduction of aberration‐corrected and monochromatic electron optics during the last decade opened a new era of nanoscopy and nanoanalysis at sub‐0.1 nm lateral resolution and sub‐electronvolt energy resolution levels with improved signal‐to‐noise ratio (SNR). Basic data characterizing the current state‐of‐the‐art and trends in development of electron nanoscopy and nanoanalysis are presented.
Ultrafast Electrochemical TechniquesUpdate based on the original article by Robert J. Forster,
Encyclopedia of Analytical Chemistry
, © 2000, John Wiley & Sons, Ltd.
Authors: Mallon Colm , Keyes Tia E. , Forster Robert J. 
Published: March 2013

Abstract
Ultrafast electrochemical techniques provide information about the kinetics and thermodynamics of redox processes that occur at microsecond to nanosecond timescales. This short timescale is achieved either by making very rapid transient measurements or by using ultrasmall probes to achieve very high rates of diffusion under steady‐state conditions. Micro‐ and nanoelectrodes, i.e., electrodes with critical dimensions in the micrometer to nanometer range, play pivotal roles in both approaches. Electrochemistry has several advantages over spectroscopy in that it provides direct information about electron transfer and coupled chemical reactions. Here, we discuss the key factors that influence the ability to make short timescale measurements using dynamic and steady‐state approaches, as well as applications ranging from heterogeneous and homogeneous electron transfer dynamics to analytical applications.
Saxitoxin Analysis
Authors: Halme Mia , Vanninen Paula 
Published: March 2013

Abstract
This article gives a review of the chemistry, mechanism of action, and analysis methods for screening and identification of saxitoxin (STX) in light of verification of the Chemical Weapons Convention (CWC). STX is a potent, naturally occurring neurotoxin, and listed in the CWC. Isolation and sample preparation from mussels and algal samples are briefly described. Analysis methods for the determination of STX have been developed mainly for environmental monitoring, seafood regulation, or medical diagnostic purposes. Different biological, biochemical, and chemical techniques have been used widely all around the world for analysis of STX and its analogs. Over the last decade, liquid chromatography‐tandem mass spectrometry (LC‐MS/MS) has become an important method in the field of the analysis of chemical warfare agents and it is also appropriate for unambiguous identification of STX and its analogs. For verification of the CWC, identification criteria for STX accepted by the Organisation for Prohibition of Chemical Weapons (the OPCW) are also discussed briefly.
Retino‐Dural Hemorrhage of Infancy
Authors: Squier Waney 
Published: March 2013

AbstractThe termshaken baby syndrome(SBS), defined by the triad of retinal hemorrhage (RH), encephalopathy, and subdural hemorrhage (SDH), despite being widely accepted for 40 years, can no longer be regarded as a valid diagnosis. Multiple lines of evidence, from biomechanics to advances in understanding the anatomy and pathophysiology of the developing infant brain and its coverings, have undermined the diagnosis, and the nomenclature has been revised to reflect this.It is important to shift the focus to the objective pathological findings in babies with these closely interrelated phenomena rather than speculating on mechanisms; the term retino‐dural haemorrhage of infancy more accurately characterizes this syndrome.RHs have many causes and are more common after natural disease and accidents than after inflicted injury. Encephalopathy results from hypoxic‐ischemic injury rather than from traumatic axonal injury. Trauma is a cause of infant SDH, but there are many natural causes; almost half of normal newborns have SDH identified on brain scan. Infant SDH is usually a thin bilateral film, its source traditionally ascribed to torn bridging veins, but this remains unproved and is rarely documented. The dura is an alternative source; the infant dura is richly vascularized and innervated and bleeding into it is common. SDH evolves into a reactive membrane containing thin‐walled capillaries. Recurrent bleeding into these membranes is seen on microscopy. In some cases, SDH evolves into a chronic fluid collection; the causes for this are unknown.Biomechanical studies have shown that the forces generated by shaking are far less than those resulting from impact, but it remains correct to advise parents that babies should never be shaken.This article examines the pathology of each of these signs and their pathophysiology.The importance of considering the birth, early clinical history, and predisposing vulnerabilities when examining a case of suspected abuse is emphasized.
Friction Ridge Skin: Comparison and Identification
Authors: Langenburg Glenn , Hall Carey 
Published: March 2013

AbstractFriction ridge skin covers the epidermal surface of the fingers, palms, toes, and soles of the feet. This specially adapted skin has long attracted the attention of many cultures and has a variety of forensic applications in modern contexts. Friction ridge examination has played an important part in modern criminal investigations, biometrics, and legal proceedings. Research continues to expand the boundaries of forensic uses of friction ridge skin and their impressions. A growing body of research has begun to provide a better understanding of the strengths and limitations present in friction ridge examinations.
Metallocenter Biosynthesis & AssemblyUpdate based on the original article by Scott B. Mulrooney and Robert P. Hausinger,Encyclopedia of Inorganic Chemistry© 2005, John Wiley & Sons, Ltd
Authors: Mulrooney Scott B. , Hausinger Robert P. 
Published: March 2013

AbstractCells synthesize biological metallocenters by use of several recurring themes, often with multiple themes combined into a single pathway. In the simplest situation, binding of a metal ion to a biological ligand occurs by reversible thermodynamic control; however, the prevalence of metallocenters deeply buried within macromolecules, the exceedingly low concentrations of free metal ions within cells, and the sophisticated structures of many metal‐containing active sites and cofactors provide evidence that alternative and more complex approaches must also exist. In some cases, metal binding is accompanied by posttranslational modification of the target protein, either before or after the metal binds. Many metallocenters contain additional components that are added along with the metal ion. In other cases, metallochaperones are used to deliver the metal of interest to an apoprotein. Another alternative is to incorporate the metal into a protein subunit that subsequently swaps for an apoprotein subunit in the native protein. In addition, electron‐transfer reactions may be coupled with metal assembly. Other proteins require a preassembled metal‐containing cofactor rather than just the free metal ions. The cofactor may bind reversibly or be delivered by a chaperone, and scaffolding proteins may be used to provide a framework for construction of such a cofactor. Covalent attachment of the cofactor occurs in some cases. Finally, molecular chaperones that directly or indirectly alter the conformation of the target apoprotein may be utilized. In many cases, the function of the molecular chaperone is coupled to nucleotide triphosphate hydrolysis. Examples are provided for each of these metallocenter biosynthetic mechanisms.
3‐Chlorooxindoles: Versatile Starting Materials for Asymmetric Organocatalytic Synthesis of Spirooxindoles
Authors: Noole Artur , Ošeka Maksim , Pehk Tõnis , Öeren Mario , Järving Ivar , Elsegood Mark R. J. , Malkov Andrei V. , Lopp Margus , Kanger Tõnis 
Published: March 2013

Abstract3‐Chlorooxoindoles have emerged as versatile precursors in the synthesis of spirocyclopropyl oxindoles. High enantio‐ and diastereoselectivity was attained under conditions of both iminium/enamine and H‐bonding catalysis.
Domain Purity, Miscibility, and Molecular Orientation at Donor/Acceptor Interfaces in High Performance Organic Solar Cells: Paths to Further Improvement
Authors: Ma Wei , Tumbleston John R. , Wang Ming , Gann Eliot , Huang Fei , Ade Harald 
Published: March 2013

AbstractDomain purity and interface structure are known to be critical for fullerene‐based bulk heterojunction (BHJ) solar cells, yet have been very difficult to study. Using novel soft X‐ray tools, we delineate the importance of these parameters by comparing high performance cells based on a novel naphtha[1,2‐c:5,6‐c]bis[1,2,5]thiadiazole (NT) material to cells based on a 2,1,3‐benzothiadiazole (BT) analogue. BT‐based devices exhibit ∼15 nm, mixed domains that differ in composition by at most 22%, causing substantial bimolecular recombination. In contrast, NT‐based devices have more pure domains that are >80 nm in size, yet the polymer‐rich phase still contains at least 22% fullerene. Power conversion efficiency >6% is achieved for NT devices despite a domain size much larger than the nominal exciton diffusion length due to a favourable trade‐off in the mixed domain between exciton harvesting, charge transport, and bimolecular recombination. The miscibility of the fullerene with the NT and BT polymer is measured and correlated to the purity in devices. Importantly, polarized x‐ray scattering reveals preferential face‐on orientation of the NT polymer relative to the PCBM‐rich domains. Such ordering has previously not been observed in fullerene‐based solar cells and is shown here to be possibly a controlling or contributing factor to high performance.
Bony pelvic canal size and shape in relation to body proportionality in humans
Authors: Kurki Helen K. 
Published: March 2013

ABSTRACTObstetric selection acts on the female pelvic canal to accommodate the human neonate and contributes to pelvic sexual dimorphism. There is a complex relationship between selection for obstetric sufficiency and for overall body size in humans. The relationship between selective pressures may differ among populations of different body sizes and proportions, as pelvic canal dimensions vary among populations. Size and shape of the pelvic canal in relation to body size and shape were examined using nine skeletal samples (total female n = 57; male n = 84) from diverse geographical regions. Pelvic, vertebral, and lower limb bone measurements were collected. Principal component analyses demonstrate pelvic canal size and shape differences among the samples. Male multivariate variance in pelvic shape is greater than female variance for North and South Africans. High‐latitude samples have larger and broader bodies, and pelvic canals of larger size and, among females, relatively broader medio‐lateral dimensions relative to low‐latitude samples, which tend to display relatively expanded inlet antero‐posterior (A‐P) and posterior canal dimensions. Differences in canal shape exist among samples that are not associated with latitude or body size, suggesting independence of some canal shape characteristics from body size and shape. The South Africans are distinctive with very narrow bodies and small pelvic inlets relative to an elongated lower canal in A‐P and posterior lengths. Variation in pelvic canal geometry among populations is consistent with a high degree of evolvability in the human pelvis. Am J Phys Anthropol 151:88–101, 2013. © 2013 Wiley Periodicals, Inc.
Sinonasal anatomic variants and asthma are associated with faster development of chronic rhinosinusitis in patients with allergic rhinitis
Authors: Sedaghat Ahmad R. , Gray Stacey T. , Chambers Kyle J. , Wilke Claus O. , Caradonna David S. 
Published: March 2013

BackgroundAllergic rhinitis (AR) and chronic rhinosinusitis (CRS) are a major burden to the healthcare system. Although no causal relationship has been established, previous work has demonstrated a strong association of AR with CRS. In this study, we sought to identify risk factors that may influence speed of development of CRS in patients with AR.MethodsRetrospective review of all patients diagnosed with AR without CRS presenting to an otolaryngology clinic at a tertiary medical center as part of a multidisciplinary allergy evaluation between March 2004 and November 2011. Medical records were evaluated for clinicodemographic factors including age, gender, smoking history, medical comorbidities, categories of AR based on formal allergy testing, the presence of sinonasal anatomic variants on computed tomography as well as subsequent development of CRS.ResultsFaster progression to CRS in patients with AR was associated with comorbid asthma (hazard ratio [HR] = 3.97) as well as sinonasal anatomic variants, such as infraorbital cells (HR = 7.39), and frontal intersinus cells (HR = 68.03), on multivariate survival analysis. A statistically significant but negative interaction between infraorbital cells and frontal intersinus cells suggests that concomitant presence of both leads to a less than additive increase in the rate of CRS progression.ConclusionSinonasal anatomical variants, infraorbital cells, and frontal intersinus cells, as well as comorbid asthma are associated with faster development of CRS in patients with AR. The presence of these clinical risk factors identifies patients who should be counseled on compliance with medical therapy for AR.
Enantiomeric separation of tolperisone and eperisone by reversed‐phase HPLC with cellulose tris(3‐chloro‐4‐methylphenylcarbamate)‐coated chiral column
Authors: Owada Yuri , Takahashi Mizuho , Iwasa Sumiko , Ichiba Hideaki , Sadamoto Kiyomi , Fukushima Takeshi 
Published: March 2013

ABSTRACTEnantiomeric separations of centrally acting muscle relaxants, that is, tolperisone (TOL) and eperisone (EP), that are marketed as racemates were investigated by reversed‐phase high‐performance liquid chromatography (HPLC) on a polysaccharide‐based chiral column. Both TOL and EP are basic drugs because they contain a tertiary amino group and have similar chemical structures with the exception of the p‐methylphenyl and p‐ethylphenyl groups in TOL and EP, respectively. A reversed‐phase chiral column, that is, a Chiralcel OZ‐RH column, which bears cellulose tris(3‐chloro‐4‐methylphenylcarbamate) as the chiral moiety, was effective for the enantiomeric separation of TOL and EP enantiomers. The separation factor and resolution values obtained for TOL were 1.22 and 1.66, respectively, and those for EP were 1.21 and 2.24, respectively, using a 20 mm ammonium acetate in H2O (pH 8.0 and 7.0, respectively)–CH3CN (70:30) mobile phase. Using the proposed HPLC conditions, it was found that (R)‐TOL eluted faster than (S)‐TOL, as revealed by the optical rotation and circular dichroism spectroscopy. In contrast, EP was easily racemized under the experimental conditions, and hence, the elution order was not determined. Copyright © 2013 John Wiley & Sons, Ltd.
A liquid chromatography–mass spectrometric method for the quantification of azithromycin in human plasma
Authors: Ben‐Eltriki Mohamed , Somayaji Vishwa , Padwal Raj S. , Brocks Dion R. 
Published: March 2013

ABSTRACTA liquid chromatographic mass spectrometric assay for the quantification of azithromycin in human plasma was developed. Azithromycin and imipramine (as internal standard, IS) were extracted from 0.5 mL human plasma using extraction with diethyl ether under alkaline conditions. Chromatographic separation of drug and IS was performed using a C18 column at room temperature. A mobile phase consisting of methanol, water, ammonium hydroxide and ammonium acetate was pumped at 0.2 mL/min. The mass spectrometer was operated in positive ion mode and selected ion recording acquisition mode. The ions utilized for quantification of azithromycin and IS were m/z 749.6 (M + H) + and m/z 591.4 (fragment) for azithromycin, and 281.1 m/z for internal standard; retention times were 6.9 and 3.4 min, respectively. The calibration curves were linear (r2 > 0.999) in the concentration ranges of 10–1000 ng/mL. The mean absolute recoveries for 50 and 500 ng/mL azithromycin and 1 µg/ mL IS were >75%. The percentage coefficient of variation and mean error were <11%. Based on validation data, the lower limit of quantification was 10 ng/mL. The present method was successfully applied to determine azithromycin pharmacokinetic parameters in two obese volunteers. The assay had applicability for use in pharmacokinetic studies. Copyright © 2013 John Wiley & Sons, Ltd.
Self‐Sorting of Four Organic Molecules into a Heterowheel Polypseudorotaxane
Authors: Li Liang , Zhang Heng‐Yi , Zhao Jin , Li Nan , Liu Yu 
Published: March 2013

AbstractThe social self‐sorting supramolecular assembly is described by non‐covalent interactions among four organic components. Toward this goal, a series of self‐sorting systems have been investigated by mixing two or three different compounds; naphthyl‐bridged bis(α‐cyclodextrin), N,N′‐dioctyl‐4,4′‐bipyridinium, 2,6‐dihydroxynaphthalene, and cucurbit[8]uril. The influence of alkyl chains of viologen derivatives and the binding abilities of these systems have also been studied. Their integrative self‐sorting led to the exclusive formation of the purple supramolecular heterowheel polypseudorotaxane. The heterowheel polypseudorotaxane is a thermodynamically stable self‐sorted product, and consists of two different macrocycles with three sorts of different non‐covalent interactions. Its structure was established by NMR spectroscopy and UV/Vis absorption spectroscopy, transmission electron microscopy (TEM), atomic force microscopy (AFM), dynamic light‐scattering (DLS), diffusion‐ordered spectroscopy (DOSY), and viscosity measurements.
A predictive model to identify hospitalized cancer patients at risk for 30‐day mortality based on admission criteria via the electronic medical record
Authors: Ramchandran Kavitha J. , Shega Joseph W. , Von Roenn Jamie , Schumacher Mark , Szmuilowicz Eytan , Rademaker Alfred , Weitner Bing Bing , Loftus Pooja D. , Chu Isabella M. , Weitzman Sigmund 
Published: March 2013

BACKGROUNDThis study sought to develop a predictive model for 30‐day mortality in hospitalized cancer patients, by using admission information available through the electronic medical record.METHODSObservational cohort study of 3062 patients admitted to the oncology service from August 1, 2008, to July 31, 2009. Matched numbers of patients were in the derivation and validation cohorts (1531 patients). Data were obtained on day 1 of admission and included demographic information, vital signs, and laboratory data. Survival data were obtained from the Social Security Death Index.RESULTSThe 30‐day mortality rate of the derivation and validation samples were 9.5% and 9.7% respectively. Significant predictive variables in the multivariate analysis included age (P < .0001), assistance with activities of daily living (ADLs; P = .022), admission type (elective/emergency) (P = .059), oxygen use (P < .0001), and vital signs abnormalities including pulse oximetry (P = .0004), temperature (P = .017), and heart rate (P = .0002). A logistic regression model was developed to predict death within 30 days: Score = 18.2897 + 0.6013*(admit type) + 0.4518*(ADL) + 0.0325*(admit age) − 0.1458*(temperature) + 0.019*(heart rate) − 0.0983*(pulse oximetry) − 0.0123 (systolic blood pressure) + 0.8615*(O2 use). The largest sum of sensitivity (63%) and specificity (78%) was at −2.09 (area under the curve = −0.789). A total of 25.32% (100 of 395) of patients with a score above −2.09 died, whereas 4.31% (49 of 1136) of patients below −2.09 died. Sensitivity and positive predictive value in the derivation and validation samples compared favorably.CONCLUSIONSClinical factors available via the electronic medical record within 24 hours of hospital admission can be used to identify cancer patients at risk for 30‐day mortality. These patients would benefit from discussion of preferences for care at the end of life. Cancer 2013;119:2074–2080. © 2013 American Cancer Society.