bluuebunny/crossref_metadata_2025_split huggingface dataset:
Metal displacement and stoichiometry of protein‐metal complexes under native conditions using capillary electrophoresis/mass spectrometry
Authors: Moini Mehdi 
Published: September 2010

AbstractIncreases in the study of protein‐metal complexes, as well as in metal displacement in protein‐metal complexes under native conditions for optimum catalytic properties in drug research and catalyst design, demands a separation/detection technology that can accurately measure metal displacement and stoichiometry in protein‐metal complexes. Both nuclear magnetic resonance (NMR) and X‐ray diffraction techniques have been used for this purpose; however, these techniques lack sensitivity. Electrospray ionization mass spectrometry (ESI‐MS) using direct infusion offers higher sensitivity than the former techniques and provides molecular distribution of various protein‐metal complexes. However, since protein‐metal complexes under native conditions usually are dissolved in salt solutions, their direct ESI‐MS analysis requires off‐line sample clean‐up prior to MS analysis to avoid sample suppression during ESI. Moreover, direct infusion of the salty solution promotes non‐specific salt adduct formation by the protein‐metal complexes under ESI‐MS, which complicates the identification and stoichiometry measurements of the protein‐metal complexes. Because of the high mass of protein‐metal complexes and lack of sufficient resolution by most mass spectrometers to separate non‐specific from specific metal‐protein complexes, accurate protein‐metal stoichiometry measurements require some form of sample clean up prior to ESI‐MS analysis. In this study, we demonstrate that capillary electrophoresis/electrospray ionization in conjunction with a medium‐resolution (∼10 000) mass spectrometer is an efficient and fast method for the measurement of the stoichiometry of the protein‐metal complexes under physiological conditions (pH ∼7). The metal displacement of Co2+ to Cd2+, two metal ions necessary for activation in the monomeric AHL lactonase produced by B. thuringiensis, has been used as a proof of concept. Copyright © 2010 John Wiley & Sons, Ltd.
Gas chromatography/time‐of‐flight mass spectrometry‐based metabonomics of hepatocarcinoma in rats with lung metastasis: elucidation of the metabolic characteristics of hepatocarcinoma at formation and metastasis
Authors: Li Zong‐Fang , Wang Juan , Huang Chen , Zhang Shu , Yang Jun , Jiang An , Zhou Rui , Pan Dun 
Published: September 2010

AbstractHepatocarcinoma (HCC) has a very high mortality rate and the high recurrence and metastasis rates contribute to the poor prognosis of HCC patients. To understand HCC formation and metastasis, we assessed the metabonomics of rat HCC and HCC with lung metastasis (HLM). The HLM rat model was established by exposure to diethylnitrosamine (DEN). Levels of serum and urine metabolites were quantified with gas chromatography/time‐of‐flight mass spectrometry (GC/TOFMS), and data were analyzed with partial least‐squares discrimination analysis (PLS‐DA). Serum and urine levels of some metabolites differed significantly between the control, HCC, and HLM groups. The products and intermediates from glycolysis and glutamate metabolism were elevated, while the tricarboxylic acid (TCA) cycle was inhibited, in both HCC and HLM. HLM samples revealed enhanced metabolism of nucleic acids, amino acids and glucuronic acid. PLS‐DA indicated that principal component weighting was greatest for serum serine, phenylalanine, lactic acid, tyrosine and glucuronic acid, and urine glycine, serine, 5‐oxyproline, malate, hippuric acid and uric acid. These data provide novel information that will improve understanding of the pathophysiological processes involved in HCC and HLM, and revealed potential metabolic markers for HCC invasion and metastasis. Copyright © 2010 John Wiley & Sons, Ltd.
Coordinated control and experimentation of the dental arch generator of the tooth‐arrangement robot
Authors: Zhang Yong‐de , Jiang Jin‐gang , Lv Pei‐jun , Wang Yong 
Published: September 2010

AbstractBackgroundThe traditional way of acquiring the dental arch curve form is based on manual operation, which will randomly bring numerous errors caused by human factors. The purpose of this paper is to automatically acquire the dental arch curve and implement the coordinated control of the dental arch generator of the multi‐manipulator tooth‐arrangement robot, which can be used in full denture manufacturing.MethodsBased on the arc length constant theory, kinematics on dental arch generator is analyzed. The control pulse realization methods of high‐resolution timing and CPU time‐stamp timing are studied, and testing and comparative analysis of the control precision and stability of the two methods is carried out. Control experimentation of the dental arch generator and preliminary tooth‐arrangement experimentation are performed using the multi‐manipulator tooth‐arrangement robot system.ResultsThe dental arch generator can automatically generate a dental arch curve that fits a patient according to the patient's jaw arch parameters. Repeated positioning accuracy is 0.12 mm for the slipways which drive the dental arch generator. The maximum value of single point error is 1.64 mm when the arc width direction (x‐axis) is 37.25 mm. The experimental results indicate that the method of control pulse realized by high‐resolution timing to achieve high precision coordinated motion control of dental arch generator of tooth‐arrangement robot is feasible. The error analysis results indicate that the control strategy and technical route can fulfill the requirements for motion speed and location precision.ConclusionA novel system to generate the tooth arch curve has been developed. The traditional method of manually determining the dental arch may soon become obsolete in favour of the use of a robot to assist in generating a more standard tooth arch curve. The system can be used to manufacture a full denture. It will lay an important theoretical foundation for quantitative research of oral restoration, and also provide a way to standardize the manufacturing process of full denture. Copyright © 2010 John Wiley & Sons, Ltd.
Rapid Prototyping of Nanofluidic Systems Using Size‐Reduced Electrospun Nanofibers for Biomolecular Analysis
Authors: Park Seung‐min , Huh Yun Suk , Szeto Kylan , Joe Daniel J. , Kameoka Jun , Coates Geoffrey W. , Edel Joshua B. , Erickson David , Craighead Harold G. 
Published: September 2010

AbstractBiomolecular transport in nanofluidic confinement offers various means to investigate the behavior of biomolecules in their native aqueous environments, and to develop tools for diverse single‐molecule manipulations. Recently, a number of simple nanofluidic fabrication techniques has been demonstrated that utilize electrospun nanofibers as a backbone structure. These techniques are limited by the arbitrary dimension of the resulting nanochannels due to the random nature of electrospinning. Here, a new method for fabricating nanofluidic systems from size‐reduced electrospun nanofibers is reported and demonstrated. As it is demonstrated, this method uses the scanned electrospinning technique for generation of oriented sacrificial nanofibers and exposes these nanofibers to harsh, but isotropic etching/heating environments to reduce their cross‐sectional dimension. The creation of various nanofluidic systems as small as 20 nm is demonstrated, and practical examples of single biomolecular handling, such as DNA elongation in nanochannels and fluorescence correlation spectroscopic analysis of biomolecules passing through nanochannels, are provided.
Synthesis of Superparamagnetic CaCO3 Mesocrystals for Multistage Delivery in Cancer Therapy
Authors: Zhao Yang , Lu Yang , Hu Yan , Li Jian‐Ping , Dong Liang , Lin Li‐Ning , Yu Shu‐Hong 
Published: September 2010

AbstractTo develop a new system for site‐specific targeting, superparamagnetic CaCO3 mesocrystals with the properties of biocompatibility and biodegradability are designed and synthesized. They serve as carriers for the co‐delivery of drug and gene nanoparticles via a multistage method for cancer therapy. With a porous structure, the mesocrystalline CaCO3 particles encapsulate doxorubicin (DOX), Au–DNA, and Fe3O4@silica nanoparticles for magnetic control and therapy. As stage 1 microparticles (S1MPs), the nanoparticles–CaCO3 system is designed to protect functional sections from degradation and phagocytosis in blood circulation. After the particle margination in vascular walls, the Au–DNA nanoparticles (stage 2 nanoparticles, S2NPs) and DOX are gradually released from S1MPs by degradation towards targeted tissues for biomedical therapy. The nanoparticles–CaCO3 system exhibits high efficiency of intracellular delivery, especially in nuclear invasion. The successful expression of reporter gene and intracellular transport of DOX in vitro suggest potential as a co‐delivery system for drug and gene therapy. In a mouse tumor model, the system with particle margination and two‐step strategy affords the protection of functional nanoparticles and drug from clearance and inactivation by enzymes and proteins in vivo. The targeted delivery of S2NPs into tumors by this system is tenfold more efficient than that of the nanoparticles themselves. The drug is observed to be widely distributed in tumor slices. Thus, this platform exhibits an efficient approach in the targeted delivery of therapeutic nanoparticles and molecules via a multistage strategy, and can be used as a potential system in co‐delivery of multiple agents for biomedical imaging and therapy.
Controlling Light Localization and Light–Matter Interactions with Nanoplasmonics
Authors: Giannini Vincenzo , Fernández‐Domínguez Antonio I. , Sonnefraud Yannick , Roschuk Tyler , Fernández‐García Roberto , Maier Stefan A. 
Published: September 2010

AbstractNanoplasmonics is the emerging research field that studies light–matter interactions mediated by resonant excitations of surface plasmons in metallic nanostructures. It allows the manipulation of the flow of light and its interaction with matter at the nanoscale (10−9 m). One of the most promising characteristics of plasmonic resonances is that they occur at frequencies corresponding to typical electronic excitations in matter. This leads to the appearance of strong interactions between localized surface plasmons and light emitters (such as molecules, dyes, or quantum dots) placed in the vicinity of metals. Recent advances in nanofabrication and the development of novel concepts in theoretical nanophotonics have opened the way to the design of structures aimed to reduce the lifetime and enhance the decay rate and quantum efficiency of available emitters. In this article, some of the most relevant experimental and theoretical achievements accomplished over the last several years are presented and analyzed.
Minimally‐invasive fetal autopsy using magnetic resonance imaging and percutaneous organ biopsies: clinical value and comparison to conventional autopsy
Authors: Breeze A. C. G. , Jessop F. A. , Set P. A. K. , Whitehead A. L. , Cross J. J. , Lomas D. J. , Hackett G. A. , Joubert I. , Lees C. C. 
Published: September 2010

AbstractObjectivesAutopsy is an important investigation following fetal death or termination for fetal abnormality. Postmortem magnetic resonance imaging (MRI) can provide macroscopic information of comparable quality to that of conventional autopsy in the event of perinatal death. It does not provide tissue for histological examination, which may limit the quality of counseling for recurrence risks and elucidation of the cause of death. We sought to examine the comparability and clinical value of a combination of postmortem MRI and percutaneous fetal organ biopsies (minimally invasive autopsy (MIA)) with conventional fetal autopsy.MethodsForty‐four fetuses underwent postmortem MRI and attempted percutaneous biopsy (using surface landmarks) of major fetal organs (liver, lung, heart, spleen, kidney, adrenal and thymus) following fetal death or termination for abnormality, prior to conventional autopsy, which was considered the ‘gold standard’. We compared significant findings of the two examinations for both diagnostic information and clinical significance. Ancillary investigations (such as radiographs and placental histology) were regarded as common to the two forms of autopsy.ResultsIn 21 cases conventional autopsy provided superior diagnostic information to that of MIA. In two cases the MIA provided superior diagnostic information to that of conventional autopsy, when autolysis prevented detailed examination of the fetal brain. In the remaining 21 cases, conventional autopsy and MIA provided equivalent diagnostic information. With regard to clinical significance, however, in 32 (72.7%) cases, the MIA provided information of at least equivalent clinical significance to that of conventional autopsy. In no case did the addition of percutaneous biopsies reveal information of additional clinical significance.ConclusionsAlthough in some cases MRI may provide additional information, conventional perinatal autopsy remains the gold standard for the investigation of fetal death. The utility of adding percutaneous organ biopsies, without imaging guidance, to an MRI‐based fetal autopsy remains unproven. Postmortem MRI, combined with ancillary investigations such as placental histology, external examination by a pathologist, cytogenetics and plain radiography provided information of equivalent clinical significance in the majority of cases. Copyright © 2011 ISUOG. Published by John Wiley & Sons, Ltd.
Role of three‐dimensional ultrasound measurement of the optic tract in fetuses with agenesis of the septum pellucidum
Authors: Bault J. P. , Salomon L. J. , Guibaud L. , Achiron R. 
Published: September 2010

AbstractObjectivesTo construct reference ranges for fetal optic tract mean diameter and to report measurements in fetuses with agenesis of the septum pellucidum (SP).MethodsThree‐dimensional volumes of the optic chiasm were acquired in 98 normal fetuses during routine sonographic examination at 21–36 weeks' gestation and the diameters of the posterior left and right optic tracts were measured offline. A polynomial regression approach (mean and SD model) was used to compute reference charts for the mean fetal optic tract diameter measurements. In addition, 23 volumes were acquired in fetuses with SP agenesis for offline measurement of optic tract diameter. Complete follow‐up was obtained in 13 of these 23 cases.ResultsIn normal fetuses, the optic tract diameter increased linearly throughout gestation. There was no evidence of increased variability with gestational age (constant SD). Normal charts and equations for Z‐score calculation were constructed. Among the 13 fetuses with SP agenesis and complete follow‐up, nine had normal measurements, of which eight had normal vision postnatally. Four had hypoplastic optic tract, defined as mean optic tract diameter Z‐score below − 3. Of these, two underwent termination of pregnancy and pathological examination confirmed hypoplasia of the tract, one showed signs of hypoplasia at magnetic resonance imaging and postnatal examination confirmed blindness, and one had a hypoplastic measurement for only one tract and was born with poor vision and abnormal bilateral eye movements.ConclusionWe present new reference charts for mean fetal optic tract diameter. In fetuses with agenesis of the SP, sonography of the optic tract might be a useful tool to assess its development and may help in prenatal counseling. Copyright © 2011 ISUOG. Published by John Wiley & Sons, Ltd.
RNA diagnostics: real‐time RT‐PCR strategies and promising novel target RNAs
Authors: Mayer Günter , Müller Jens , Lünse Christina E. 
Published: September 2010

AbstractRibonucleic acid (RNA) is a multifunctional type of molecule, playing critical roles in protein biosynthesis and regulation. In recent years, suppression of protein translation by so‐called microRNAs came into the focus of research, especially because deregulation of this process has been shown to play a role in malignant transformation. Furthermore, RNA molecules circulating in the blood have been revealed as a novel class of markers for diagnosis of cancers. Moreover, genetic information of some pathogens is stored as RNA, allowing their sensitive detection using nucleic acid amplification techniques. In this article, the principle of detecting different RNA types by real‐time reverse‐transcription polymerase chain reaction applications is described. Furthermore, the emerging use of microRNA and circulating RNA profiles complementing the broad spectrum of RNA diagnosis is discussed. WIREs RNA 2011 2 32–41 DOI: 10.1002/wrna.46This article is categorized under:

Regulatory RNAs/RNAi/Riboswitches > Biogenesis of Effector Small RNAs
Regulatory RNAs/RNAi/Riboswitches > Regulatory RNAs
RNA in Disease and Development > RNA in Disease
RNA Methods > RNA Analyses In Vitro and In Silico
The tmRNA‐tagging mechanism and the control of gene expression: a review
Authors: Barends Sharief , Barend Kraal , van Wezel Gilles P. 
Published: September 2010

AbstractThe tmRNA‐mediatedtrans‐translation system is a unique quality control system in eubacteria that combines translational surveillance with the rescue of stalled ribosomes. Duringtrans‐translation, the chimeric tmRNA molecule—which acts as both tRNA and mRNA—is delivered to the ribosomal A site by a ribonucleoprotein complex of SmpB and EF‐Tu–GTP, allowing the stalled ribosome to switch template and resume translation on a small coding sequence inside the tmRNA molecule. As a result, the aberrant protein becomes tagged by a sequence that is a target for proteolytic degradation. Thus, the system elegantly combines ribosome recycling with a clean‐up function when triggered by truncated transcripts or rare codons. In addition, recent observations point to a specific regulation of the translation of a small number of genes by tmRNA‐mediated inhibition or stimulation. In this review, we discuss the most prominent biochemical and structural aspects oftrans‐translation and then focus on the specific role of tmRNA in stress management and cell‐cycle control of morphologically complex bacteria.WIREs RNA2011 2 233–246 DOI: 10.1002/wrna.48This article is categorized under:Translation > Translation MechanismsTranslation > Translation RegulationRNA Turnover and Surveillance > Turnover/Surveillance Mechanisms
Bacterial/archaeal/organellar polyadenylation
Authors: Mohanty Bijoy K. , Kushner Sidney R. 
Published: September 2010

AbstractAlthough the first poly(A) polymerase (PAP) was discovered in Escherichia coli in 1962, the study of polyadenylation in bacteria was largely ignored for the next 30 years. However, with the identification of the structural gene for E. coli PAP I in 1992, it became possible to analyze polyadenylation using both biochemical and genetic approaches. Subsequently, it has been shown that polyadenylation plays a multifunctional role in prokaryotic RNA metabolism. Although the bulk of our current understanding of prokaryotic polyadenylation comes from studies on E. coli, recent limited experiments with Cyanobacteria, organelles, and Archaea have widened our view on the diversity, complexity, and universality of the polyadenylation process. For example, the identification of polynucleotide phosphorylase (PNPase), a reversible phosphorolytic enzyme that is highly conserved in bacteria, as an additional PAP in E. coli caught everyone by surprise. In fact, PNPase has now been shown to be the source of post‐transcriptional RNA modifications in a wide range of cells of prokaryotic origin including those that lack a eubacterial PAP homolog. Accordingly, the past few years have witnessed increased interest in the mechanism and role of post‐transcriptional modifications in all species of prokaryotic origin. However, the fact that many of the poly(A) tails are very short and unstable as well as the presence of polynucleotide tails has posed significant technical challenges to the scientific community trying to unravel the mystery of polyadenylation in prokaryotes. This review discusses the current state of knowledge regarding polyadenylation and its functions in bacteria, organelles, and Archaea. WIREs RNA 2011 2 256–276 DOI: 10.1002/wrna.51This article is categorized under:

RNA Processing > 3' End Processing
RNA Turnover and Surveillance > Turnover/Surveillance Mechanisms
RNA Turnover and Surveillance > Regulation of RNA Stability
Chemische Entgiftung wichtiger organischer Cancerogene im Laboratorium
Authors: Martinetz Dieter 
Published: September 2010

AbstractDiverse classes of chemicals can induce cancer in animals and men. A review is given on laboratory detoxification of some types of chemical carcinogens and the basic principles involved in laboratory safety.No general techniques exist for the decontamination of such substances. Effective methods for the destruction of aflatoxins, aromatic amines, chloroethers, hydrazines, N‐nitrosamines and ‐amides, polycyclic aromatic hydrocarbons and some single substances (e.g. yperites, selected nitro compounds, azides, triazenes, dioxins, and captane, mercapto purine, thioguanine) in laboratory wastes are described. The methods preferred by the International Agency for Research on Cancer (Lyon) are especially considered.Destruction techniques for chemical carcinogens must be efficient, complete, irreversible, rapid, reproducible, easy to perform, and the product of detoxification must be free of mutagenic and/or carcinogenic activity.
Zu einigen Problemen in der Chromatographie; Die chromatographische Auflösung
Authors: Eppert Günter 
Published: September 2010

AbstractThe chromatographic resolution R8 is given by the product of an efficiency term, a selectivity term, and a capacity term. In the literature, there are two common used approximation formulas for R8, which give no conformable values.Therefore, it is reasonable to introduce a generally valid equation, for that I propose a proper mathematical expression. It shows that the capacity term is no independent term of resolution.Using average plate numbers, the general equation is changed into the Said equation. The Said equation is a very recommendable approximation, which should be solely used in future, instead of the common used approximation formulas.A typical function maximum exists in case of the resolution performance, which is a relevant quantity to modern chromatography.
Zur Komplexkatalyse der Aminomethylierung und Aminierung von Olefinen
Authors: Steinborn Dirk , Taube Rudolf 
Published: September 2010

AbstractThis review covers homogeneously catalyzed reactions of nonactivated olefines with aliphatic amines, α‐C  H bonds of amines react with olefines under addition to the C = C double bond in the presence of radical initiators and metal amides of early transition elements, respectively. According to Reppe the aminomethylation of olefines with CO/H2O and amines can be catalyzed by selected complexes of the VIII B groups elements. The N — H addition to olefinic double bonds is catalyzed by alkali metal compounds as well as by particular rhodium and iridium compounds. These amination reactions proceed by different mechanisms, probably with a β‐aminoethyl metal species being the most important intermediate. The chemistry of such β‐nitrogen substituted alkyl metal compounds is discussed with special attention being paid to the pronounced structure dependence of their stability and reactivity.
Tritiummarkierung von Steroiden
Authors: Wagner Horst , Römer Johannes 
Published: September 2010

AbstractThe present paper gives a survey of the prepartion of specific tritium labelled steroids of high and highest activity (up to 58 Ci/mM and 2150 GBq/mM, resp.) using the method of catalytic tritiation. It concerns steroids of all classes — androstanes, estratrienes, norandrostanes and progesterones ‐0‐‐ labelled in different positions of all the four possible rings of the steroid skeleton. The tritium labelled products have been applied in many research laboratories of the GDR and also been exported abroad.