bluuebunny/crossref_metadata_2025 huggingface dataset:
Budget impact analysis of apixaban to treat and prevent venous thromboembolism in Italy
Authors: Bellone Marco , Di Virgilio Roberto , Di Rienzo Paolo
Published: December 2016

BACKGROUND: Venous thromboembolism (VTE), a collective term for deep vein thrombosis (DVT) and pulmonary embolism (PE), is a serious vascular condition associated to high economic and clinical burden. Apixaban, a Novel Oral Anticoagulant (NOAC) has shown non-inferiority efficacy versus the current standard of care (low molecular weight heparin [LMWH]/vitamin K antagonist [VKA]) in the acute treatment and prevention of VTE and a significant reduction in the risk of bleeding.AIM: Evaluate the economic impact of the use of apixaban for treatment and prevention of DVT and PE from the perspective of the Italian National Health System (NHS).METHODS: A budget impact model was adapted in order to compare clinical outcomes and economic consequences associated to apixaban vs. LMWH/VKA and others NOACs over a three-year time horizon in the Italian setting. In the analysis two scenario were compared: status quo scenario without apixaban and an alternative scenario with apixaban. Only direct healthcare costs have been considered.RESULTS: Assuming a population of patients receiving apixaban over the first 3 years equal to 20,957, the introduction of apixaban is associated to an incremental saving of € 821,748 in the first years, € 1,250,454 in the second year, and € 1,866,466 in the third year. The total net saving over the 3-year period is € 3,938,668, which is a 2.47% decrease from the total budget for the status quo scenario without apixaban. This saving is mainly due to reduced VTE events and bleeds by apixaban. Indeed apixaban is associated with less VTE events (both fatal and non-fatal), less major bleeding and less Clinical Relevant Non Major (CRNM) bleeding with a total of 52 fatal events avoided.CONCLUSIONS: The listing of apixaban for the treatment of VTE (both DVT and PE) and the prevention of recurrent VTE provides both significant clinical advantages, in terms of deaths and events avoided, and economical advantages, consisting in a reduction in the total expenditure on the Italian NHS.
ВЕКОВНA ИСКУСТВA У ЗАШТИТИ РАЗНИХ ОБЛИКА ЗАПИСА АРХИВСКЕ ГРАЂЕ КАО ЈЕДАН ОД ПРЕДУСЛОВА ЗА ЊЕНО ЗАКОНСКО УРЕЂЕЊЕ
Authors: ПОПОВИЋ ЈОВАН
Published: December 2016

Трагови архивистике сежу у далеку прошлост. Свест о чува-њу и заштити архивске грађе мењала се од времена до времена, зависно од дру-штвених прилика. Архивска грађа представља најважнији траг људског дру-штва из прошлости, који се организовано чува и аутентично сведочи о постоја-њу одређених радњи, догађаја и процеса. Велика количина архивске грађе из ранијих векова је сачувана, иако није увек постојало архивско законодавсто. Логично је запитати се које су то природне и друштвене силе допринеле да се та грађа спаси све до данашњих дана. И заиста, право је умеће било сачувати ту архивску грађу. Данас је основни стуб успешног обављања архивске делатно-сти у свакој држави архивско законодавство. Доношењем и применом архив-ског законодавства умрежавају се архивске институције и уређују начин упра-вљања, заштита, валоризација, дигитализација и коришћење архивске грађе.На просторима бивше СФРЈ донето је стотињак законских и подзакон-ских прописа, што је најчешће резултат промена устава и системских закона.Аутор наводи забележене изјаве или објављене цитате великих угледни-ка науке и културе о архивима и архивској грађи.
OBNOVA MANASTIRSKE CRKVE U DOBRUNU (1886)
Authors: BOŽIĆ JELENA
Published: December 2016

U radu su predstavljeni rezultati istraživanja restauracije dobrunske srednjovjekovne manastirske crkve u 19. vijeku. Crkva u Dobrunu je dragocjena sakralna građevina velikog istorijskog i arhitektonskog značaja. Studija je bazirana na interpretaciji istorijskih izvora i sugeriše moguće odgovore na pitanja hronologije crkve. Prema njima, crkva datira iz sredine 14. vijeka (1340–1343). Tokom vijekova dešavale su se različita oštećenja i crkva nije opstala u originalnoj formi i konceptu. Pretrpjela je brojne promjene, a gornje dijelove, oštećene 1875, restaurirao je Josip Vancaš, najznačajniji arhitekt austrougarskog perioda u Bosni i Hercegovini.Stil stare građevine pripada vizantijskoj umjetnosti, najznačajnijem kultur-nom fenomenu evropske istorije. Trajala je duže nego ijedan drugi stil, pokrivajući ogroman geografski prostor. Srpska srednjovjekovna umjetnost predstavlja sintezu vizantijskog koncepta i romaničkih dekorativnih formi.U skladu s evropskom teorijom i praksom zaštite spomenika kulture u 19. vijeku, kao i u skladu s vlastitim stavovima i uvjerenjima, Vancaš je obnovio veliku kulturno-istorijsku vrijednost crkve. Njegova obnova se temelji na harmoniji postoje-će vizantijske prostorne koncepcije i romaničke arhitektonske plastike.
ПОЛИТИЧКА МОБИЛИЗАЦИЈА ЖЕНА У АРГЕНТИНИ: МАЈКЕ ТРГА МАЈО
Authors: САЈИЋ НИНА
Published: December 2016

Рад се бави политичком мобилизацијом жена у Аргентини након успостављaња посљедње војне диктатуре у земљи 1976. године, за врије-ме које је нестало између 20.000 и 30.000 људи. У раду је дат историјски пре-глед догађаја који су довели до стварања једне од најутицајних организација жена у Аргентини и Латинској Америци, Мајке Трга Мајо. Рад приказује акти-визам жена, у највећем броју домаћица без формалног образовања, које су своје биолошко мајчинство трансформисале у политичко. Мајке Трга Мајо су и данас, скоро четрдест година од оснивања, и даље политички веома активне.
ПРЕГЛЕД ДЈЕЛОВАЊА ПАРАВОЈНЕ ФОРМАЦИЈЕ ХОС ЗА ВРИЈЕМЕ ГРАЂАНСКОГ РАТА У БОСНИ И ХЕРЦЕГОВИНИ
Authors: РАДАКОВИЋ БОРИС
Published: December 2016

Питања из скорије прошлости, нарочито период разбијања СФРЈ и грађанског рата, у српској историографији још увијек нису обрађена на задовољавајући начин, штавише, веома мало се и писало о овим темама. Рад који је пред читаоцем даје преглед, на основу доступне архивске грађе, дјелова-ња паравојне организације ХОС, коју је створила Хрватска странка права као своју страначку војску, а која је била састављена од Хрвата и муслимана.
Данко Боројевић, Драги Ивић, Војска Републике Српске 12. мај 1992. ‒ 31. децембар 2005, Српски Ратни Ветерани општине Чукарица, Београд 2014, 394 стр.
Authors: РАДАКОВИЋ БОРИС
Published: December 2016

Данко Боројевић и Драги Ивић, бивши официри Војске Републике Срп-ске (ВРС), написали су књигу која описује историју Војске Републике Српске од њеног настанка па све док није укинута, кад су њени дијелови ушли у састав Оружаних снага БиХ.Увод књиге бави се српским питањем на Балкану, хронолошки, од Француске револуције (1789) до оснивања ВРС, која је у вријеме оснивања носила назив Војска Српске Републике Босне и Херцеговине (12. маја 1992. године). Аутори се у уводу највише задржавају на Првом и Другом свјетском рату и њиховим посљедицама по Србе, како на оне у БиХ тако и на све Србе на Балкану. Укратко приказују и уређење Социјалистичке Федеративне Републике Југославије и све мане ове државе, која се показала недораслом изазовима националних и идеолошких супротности између њених народа, као и донекле подређен положај Срба у њој.
Душан В. Кузмановић, Кузмановићи (породични родослов), Народна библиотека ''Данило Киш'', Теслић 2015, стр. 321
Authors: ВАСИЋ ДРАГИША
Published: December 2016

Родословље или генеалогија изучава постанак, поријекло и развој поро-дице. Родослови су били међу најважнијим врстама историографије од њених почетака. Дуго су писани једино родослови владарских и других угледних породица, док су у широким народним масама родослови преношени усменим путем с кољена на кољено. Упознавање са ближим и даљим прецима незаоби-лазно је и у самоспознаји савременог човјека, поготово јер је он честица потро-шачког друштва коју одликује отуђеност. Стога су генеалошка истраживања у наше вријеме веома потребна. Ипак, мало је одличних родослова због оскудно-сти, разуђености и фрагментарности изворне грађе, као и нестручности њихо-вих аутора.
Coincidence detection and bi-directional transmembrane signaling control a bacterial second messenger receptor
Authors: Cooley Richard B , O’Donnell John P , Sondermann Holger
Published: December 2016

The second messenger c-di-GMP (or cyclic diguanylate) regulates biofilm formation, a physiological adaptation process in bacteria, via a widely conserved signaling node comprising a prototypical transmembrane receptor for c-di-GMP, LapD, and a cognate periplasmic protease, LapG. Previously, we reported a structure-function study of a soluble LapD•LapG complex, which established conformational changes in the receptor that lead to c-di-GMP-dependent protease recruitment (Chatterjee et al., 2014). This work also revealed a basal affinity of c-di-GMP-unbound receptor for LapG, the relevance of which remained enigmatic. Here, we elucidate the structural basis of coincidence detection that relies on both c-di-GMP and LapG binding to LapD for receptor activation. The data indicate that high-affinity for LapG relies on the formation of a receptor dimer-of-dimers, rather than a simple conformational change within dimeric LapD. The proposed mechanism provides a rationale of how external proteins can regulate receptor function and may also apply to c-di-GMP-metabolizing enzymes that are akin to LapD.
A microRNA negative feedback loop downregulates vesicle transport and inhibits fear memory
Authors: Mathew Rebecca S , Tatarakis Antonis , Rudenko Andrii , Johnson-Venkatesh Erin M , Yang Yawei J , Murphy Elisabeth A , Todd Travis P , Schepers Scott T , Siuti Nertila , Martorell Anthony J , Falls William A , Hammack Sayamwong E , Walsh Christopher A , Tsai Li-Huei , Umemori Hisashi , Bouton Mark E , Moazed Danesh
Published: December 2016

The SNARE-mediated vesicular transport pathway plays major roles in synaptic remodeling associated with formation of long-term memories, but the mechanisms that regulate this pathway during memory acquisition are not fully understood. Here we identify miRNAs that are up-regulated in the rodent hippocampus upon contextual fear-conditioning and identify the vesicular transport and synaptogenesis pathways as the major targets of the fear-induced miRNAs. We demonstrate that miR-153, a member of this group, inhibits the expression of key components of the vesicular transport machinery, and down-regulates Glutamate receptor A1 trafficking and neurotransmitter release. MiR-153 expression is specifically induced during LTP induction in hippocampal slices and its knockdown in the hippocampus of adult mice results in enhanced fear memory. Our results suggest that miR-153, and possibly other fear-induced miRNAs, act as components of a negative feedback loop that blocks neuronal hyperactivity at least partly through the inhibition of the vesicular transport pathway.
Deciphering the preservation of fossil insects: a case study from the Crato Member, Early Cretaceous of Brazil
Authors: Osés Gabriel Ladeira , Petri Setembrino , Becker-Kerber Bruno , Romero Guilherme Raffaeli , Rizzutto Marcia de Almeida , Rodrigues Fabio , Galante Douglas , da Silva Tiago Fiorini , Curado Jessica F. , Rangel Elidiane Cipriano , Ribeiro Rafael Parra , Pacheco Mírian Liza Alves Forancelli
Published: December 2016

Exceptionally well-preserved three-dimensional insects with fine details and even labile tissues are ubiquitous in the Crato Member Konservat Lagerstätte (northeastern Brazil). Here we investigate the preservational pathways which yielded such specimens. We employed high resolution techniques (EDXRF, SR-SXS, SEM, EDS, micro Raman, and PIXE) to understand their fossilisation on mineralogical and geochemical grounds. Pseudomorphs of framboidal pyrite, the dominant fossil microfabric, display size variation when comparing cuticle with inner areas or soft tissues, which we interpret as the result of the balance between ion diffusion rates and nucleation rates of pyrite through the originally decaying carcasses. Furthermore, the mineral fabrics are associated with structures that can be the remains of extracellular polymeric substances (EPS). Geochemical data also point to a concentration of Fe, Zn, and Cu in the fossils in comparison to the embedding rock. Therefore, we consider that biofilms of sulphate reducing bacteria (SRB) had a central role in insect decay and mineralisation. Therefore, we shed light on exceptional preservation of fossils by pyritisation in a Cretaceous limestone lacustrine palaeoenvironment.
Molecular phylogenetics, seed morphometrics, chromosome number evolution and systematics of EuropeanElatineL. (Elatinaceae) species
Authors: Sramkó Gábor , Molnár V. Attila , Tóth János Pál , Laczkó Levente , Kalinka Anna , Horváth Orsolya , Skuza Lidia , Lukács Balázs András , Popiela Agnieszka
Published: December 2016

The genusElatinecontainsca25 species, all of which are small, herbaceous annuals distributed in ephemeral waters on both hemispheres. However, due to a high degree of morphological variability (as a consequence of their amphibious life-style), the taxonomy of this genus remains controversial. Thus, to fill this gap in knowledge, we present a detailed molecular phylogenetic study of this genus based on nuclear (rITS) and plastid (accD-psaI,psbJ-petA,ycf6-psbM-trnD) sequences using 27 samples from 13 species. On the basis of this phylogenetic analysis, we provide a solid phylogenetic background for the modern taxonomy of the European members of the genus. Traditionally accepted sections of this tree (i.e., CryptaandElatinella) were found to be monophyletic; onlyE. borchoni—found to be a basal member of the genus—has to be excluded from the latter lineage to achieve monophyly. A number of taxonomic conclusions can also be drawn:E. hexandra, a high-ploid species, is most likely a stabilised hybrid between the main sections;E. campylospermamerits full species status based on both molecular and morphological evidence;E. gussoneiis a more widespread and genetically diverse species with two main lineages; and the presence of the AsianE. ambiguain the European flora is questionable. The main lineages recovered in this analysis are also supported by a number of synapomorphic morphological characters as well as uniform chromosome counts. Based on all the evidence presented here, two new subsections withinElatinellaare described: subsectionHydropiperaconsisting of the temperate species of the section, and subsectionMacropodaeincluding the Mediterranean species of the section.
Cretaceous origin of dogwoods: an anatomically preservedCornus(Cornaceae) fruit from the Campanian of Vancouver Island
Authors: Atkinson Brian A. , Stockey Ruth A. , Rothwell Gar W.
Published: December 2016

Background

Cornaceae consists of 58 species, all within the genusCornus. The Cenozoic record ofCornusis extensive and well documented. Molecular divergence-time studies suggest that crown-groupCornusmay have originated by the Late Cretaceous. However, there has been no formal report ofCornusfrom Cretaceous deposits. Here, we characterize a permineralized fossil fruit assignable toCornussubg.Cornusfrom the Upper Cretaceous (Campanian) Shelter Point locality of Vancouver Island, British Columbia, Canada.

Methods

Serial sections of the specimen were made using the cellulose acetate peel technique. Peels were mounted onto microscope slides and studied by light microscopy.

Results

The fossil fruit consists of a tri-locular woody endocarp with dorsal germination valves. The locules are sub-triangular to ellipsoidal in transverse section and are separated by thin septa. Endocarp tissue consists of elongated and isodiametric sclereids and secretory cavities. Internal vascular tissue was not observed, but is interpreted to have been located along the outer periphery of the septa for some length, common in many cornalean taxa. There is one seed in each locule, one of which was found to have endosperm and a dicotyledonous embryo.

Discussion

Woody endocarps with germination valves, without central vascular bundles, and with one seed per locule are characteristic of several families within the order Cornales. The interpreted vascular pattern and presence of secretory cavities indicates that the fossil fruit is assignable toCornussubg.Cornus. Comparative analysis suggests that the fossil is most similar toCornus piggae, a species described from the Paleocene of North Dakota. This fossil is the first evidence of crown-group Cornaceae from the Cretaceous and sheds light on both the plesiomorphic fruit characters and the timing of the initial diversification of the family and basal asterid lineage, Cornales.
Floral development and vascularization help to explain merism evolution inPaepalanthus(Eriocaulaceae, Poales)
Authors: Silva Arthur de Lima , Trovó Marcelo , Coan Alessandra Ike
Published: December 2016

Background

Flowers in Eriocaulaceae, a monocot family that is highly diversified in Brazil, are generally trimerous, but dimerous flowers occur inPaepalanthusand a few other genera. The floral merism in an evolutionary context, however, is unclear.Paepalanthusencompasses significant morphological variation leading to a still unresolved infrageneric classification. Ontogenetic comparative studies of infrageneric groups inPaepalanthusand in Eriocaulaceae are lacking, albeit necessary to establish evolution of characters such as floral merism and their role as putative synapomorphies.

Methods

We studied the floral development and vascularization of eight species ofPaepalanthusthat belong to distinct clades in which dimery occurs, using light and scanning electron microscopies.

Results

Floral ontogeny in dimerousPaepalanthusshows lateral sepals emerging simultaneously and late-developing petals. The outer whorl of stamens is absent in all flowers examined here. The inner whorl of stamens becomes functional in staminate flowers and is reduced to staminodes in the pistillate ones. In pistillate flowers, vascular bundles reach the staminodes. Ovary vascularization shows ventral bundles in a commissural position reaching the synascidiate portion of the carpels. Three gynoecial patterns are described for the studied species: (1) gynoecium with a short style, two nectariferous branches and two long stigmatic branches, in most species; (2) gynoecium with a long style, two nectariferous branches and two short stigmatic branches, inP. echinoides; and (3) gynoecium with long style, absent nectariferous branches and two short stigmatic branches, inP. scleranthus.

Discussion

Floral development of the studied species corroborates the hypothesis that the sepals of dimerous flowers ofPaepalanthuscorrespond to the lateral sepals of trimerous flowers. The position and vascularization of floral parts also show that, during dimery evolution inPaepalanthus, a flower sector comprising the adaxial median sepal, a lateral petal, a lateral stamen and the adaxial median carpel was lost. In the staminate flower, the outer whorl of staminodes, previously reported by different authors, is correctly described as the apical portion of the petals and the pistillodes are reinterpreted as carpellodes. The occurrence of fused stigmatic branches and protected nectariferous carpellodes substantiates a close relationship betweenP.sect.ConodiscusandP.subg.Thelxinoë. Free stigmatic branches and exposed carpellodes substantiate a close relationship betweenP. sect.Diphyomene,P. sect.EriocaulopsisandP. ser.Dimeri. Furthermore, the loss of nectariferous branches may have occurred later than the fusion of stigmatic branches in the clade that groupsP. subg.ThelxinoëandP. sect.Conodiscus.
Gas Chromatography in Screening of Chemicals Related to the Chemical Weapons Convention
Authors: Kostiainen Olli
Published: December 2016

Various gas chromatographic methods, which are useful for the screening of chemical weapons convention (CWC)‐related chemicals, are described in this article. The choice of columns, detectors, and injection techniques, crucial to the optimization of gas chromatography (GC) as a routine screening tool, is discussed. In addition, various screening and identification methods are described. The use of retention indices (RI) method allowing the identification without the need for an authentic chemical is described in detail. RIs are used as identification method also together with electron impact mass spectrometry (EIMS) in on‐site analysis method established by Organization for Prohibition of Chemical Weapons (OPCW).
Nucleic Acid Structural Energetics
Authors: Vieregg Jeffrey R.
Published: December 2016

Nucleic acids perform many functions essential for life, and exhibit a correspondingly diverse array of structures. This article provides an overview of nucleic acid structure, as well as the forces that govern its formation. The current state of knowledge of nucleic acid thermodynamics is discussed, as well as techniques for predicting and designing structures of interest. Experimental methods used to determine the structure of nucleic acids and the thermodynamics of their reactions are also surveyed.
Quantitative Structure‐Activity Relationships and Computational Methods in Drug Discovery
Authors: Balaban Alexandru T.
Published: December 2016

Among the various methods for finding new medicinal drugs, the approach using molecular descriptors for quantitative structure–activity relationships (QSAR) is described in more detail, after a brief historical introduction. Starting with Corwin Hansch's observation that for many organic compounds their biological activities can often be correlated with their lipophilicity (octanol–water partition coefficients), which in turn may be approximated by computational approaches, chemical structures proved to be the early key to drug design. How can one encode discrete chemical structures into numerical values that may then be compared with biological activities that are measured by continuous scales? One well‐working tool uses topological indices (TIs) that are graph‐theoretical invariants associated with the hydrogen‐depleted constitutional formulas. Several examples are provided evidencing that this pathway proved to be successful. For three‐dimensional (3D) chemical structures, more sophisticated theoretical methods (such as CoMFA) had to be implemented. Nowadays, powerful synthetic and analytical methods involving combinatorial chemistry and high‐throughput screening on one hand, together with refined computational approaches, try to lower the cost of each new medicinal drug, which may reach one billion US dollars.
Field‐Flow Fractionation in Analysis of Polymers and Rubbers
Authors: Williams S. Kim Ratanathanawongs , Benincasa Maria‐Anna , Smith William C. , Oliver James D.
Published: December 2016

Field‐flow fractionation (FFF) was conceived by J. Calvin Giddings in 1966 as a separation and characterization method for macromolecules, colloids, and particulates. Similar to chromatography, sample migration is caused by differential interaction with a field acting along an axis orthogonal to that of the transport liquid. Unlike chromatography, where separation is achieved by solutes partitioning between mobile and stationary phases, separation in FFF arises from the distribution of sample components in fluid laminae flowing at different velocities in a single phase. The different flow velocities, described by a parabolic profile, arise from the high aspect ratio of the FFF channel. Different types of fields can be used in FFF as long as they interact with some physicochemical property of the sample. The FFF channel design makes it highly suited for analyses of fragile aggregates, high‐molecular‐weight polymers, and gels. In comparison with packed columns, shear rates in the channel and the probability of plugging the channel are low. The ability of thermal FFF to differentiate polymers and latexes of different bulk and surface composition is unique among currently used separation techniques. The FFF family of techniques can provide a great deal of information about the sample but an initial time investment is often required for method development.

In this article, the fundamental mechanism of FFF is shown at play in the separation and characterization of polymers and rubbers by the two techniques par excellence in this field: flow FFF and thermal FFF.
Sample Preparation for
X
‐Ray Fluorescence Analysis
Authors: Marguí Eva , Queralt Ignasi , Van Grieken Rene
Published: December 2016

This article presents a complete review of different sample preparation methodologies before analysis by X‐ray spectrometry. This article presents the basics of classical preparation for X‐ray fluorescence (XRF) analysis and new methods of preparation, with emphasis on recent applications.
Saturation Transfer Difference Spectroscopy
Authors: Gairí Margarida , Feliz Miguel , García Jesús
Published: December 2016

Saturation transfer difference (STD) NMR is a powerful technique for detection and characterization of reversible binding interactions between small molecule ligands and macromolecular receptors. The STD methodology is broadly used for detection of protein–ligand interactions and for fragment screening and has also been successfully applied to complex systems such as reconstituted membranes, intact cells, platelets, or whole viruses. The basic STD experiment relies on1H NMR (Nuclear Magnetic Resonance) difference spectroscopy. Saturation transferred from the receptor to bound ligands in the complex is measured by observing the NMR signal of the ligand. The corresponding STD NMR spectrum reveals only signals of binding compounds. Quantitative analysis of the STD effects allows the identification of the binding epitope of a ligand when bound to its receptor and can also provide affinity information. Water–ligand observed gradient spectroscopy (WaterLOGSY) is a related method for the characterization of transient ligand–receptor interactions, but unlike STD, in WaterLOGSY experiments, the bulk water is the origin of the perturbation transfer.
Sensitive Chemical Detection with Distributed Feedback Interband Cascade Lasers
Authors: Vurgaftman I. , Geiser P. , Bewley W. W. , Merritt C. D. , Canedy C. L. , Warren M. V. , Kim M. , Kim C. S. , Meyer J. R.
Published: December 2016

The hybrid architecture of the interband cascade laser (ICL) combines the interband active transitions of a conventional diode laser with the multiple active stages of a quantum cascade laser (QCL). An advantage for spectroscopic applications is its much lower power dissipation than other sources such as the QCL at mid‐infrared (IR) wavelengths spanning 3–6 µm. Distributed‐feedback (DFB) ICLs emitting in a single spectral mode have been developed using both top‐grating and lateral‐grating geometries. The top‐grating approach has produced up to 28 mW of continuous wave (CW) power in a single spectral mode. Lateral‐grating DFB ICLs have produced single‐mode output throughout the 3–6 µm spectral region, often operating with drive powers <100 mW. Some of the most important extractive and in situ measurement techniques for laser‐based gas sensing are described, including direct absorption spectroscopy (DAS), wavelength modulation spectroscopy (WMS), quartz enhanced photo‐acoustic spectroscopy (QEPAS), and off‐axis integrated cavity output spectroscopy (OA‐ICOS). We review a number of applications of ICL‐based systems to the sensing of methane, ethane, formaldehyde, and sulfur dioxide.
Mass Spectrometry Analysis of Peptides in Environment
Authors: Tang Yanan , Li Feng , Huang Guang , Li Xing‐Fang
Published: December 2016

Peptides are essential components of all living organisms, widely present in the environment, and play important roles in diverse environmental processes. Some peptides are a cause of concern for ecosystems and for environmental health, including drinking water safety. Peptides may impact the environment through their involvement in nitrogen cycles, cloud formation, and many other biogeochemistry processes. Some environmental peptides (e.g. microcystins, MCs) originating from microorganisms are highly toxic, and thus their distribution and transformation in the environment are of great health concern. Many analytical tools have been developed to characterize environmental peptides. The analysis of peptides in environmental samples is challenging, however, owing to their high chemical and structural diversities, low abundance, and complex sample matrices. Mass spectrometry (MS) has become one of the most attractive techniques for environmental peptide analysis, because of its high sensitivity and selectivity. In this article, we summarize the recent advances in MS methods for the analysis of peptides in environmental samples. Particularly, we discuss the analytical developments for the analysis of peptides in water, atmospheric aerosols, and soils, as each sample type represents a distinct analytical challenge.
Synthesis and characterization of dandelion‐like
ZnS
with high antibacterial activity
Authors: Ming Fangwang , Wang Zhoucheng
Published: December 2016

Nanostructure materials have been the subject of widespread research over the past couple of decades. Recent experiments on nanostructure materials have revealed a host of novel physical and chemical properties, which are significantly different from that of the conventional materials. Many workers are devoted to developing new synthesis methods to fabricate materials with novel nanostructures. ZnS, as a vital wide‐gap semiconductor, has been extensively investigated due to its outstanding photoelectric effect, high catalytic activity and wide applications. Recently, ZnS nanomaterials with various geometrical shapes such as 1D wire, rod, or 2D sheet, belt and so on, have been prepared using variety of physical or chemical methods [1‐2]. Dandelion‐like ZnS materials assembled by 2D nanosheets or 1D nanowires are of great interest as they provide extremely large specific surface areas and unique porous microstructure [3]. However, research into the 3D nanostructure ZnS assembled by 1D ZnS nanowires is still less dealt with. What's more, majority researchers were devoted to photoluminescence and photocatalytic, few of them pay enough attention to the antibacterial activity of ZnS.

Microbial contamination has become increasing difficult to control owing to the resistance offered by microbes against conventional antimicrobial agents. It is well‐know that inorganic nanomaterials, such as TiO2, AgPO3, ZnO, reveal high antibacterial activities [4‐5]. To date, only scant information about antibacterial ability of the ZnS has been recorded. In this work, dandelion‐like ZnS has been prepared via the method of facile one‐pot hydrothermal synthesis. The dandelion‐like ZnS was characterized by transmission electron microscope, scanning electron microscope, energy dispersive spectrometer and X‐ray diffraction. The results reveal that the surface topographies of the 3D dandelion‐like ZnS particles are actually assembled by plenty of interlaced 1D ZnS nanowires. The influence of reaction time, reaction temperature, Zn/S mole ratio and different zinc and sulfur sources to the dandelion‐like structure were investigated. The dandelion‐like ZnS exhibits superior ability in inhibiting the growth of Escherichia coli, which makes it promising candidate for biological materials. The large specific surface area, porous surface morphology and the releasing of the Zn2+ ions are considered probable causes for the high antibiotic activity of the dandelion‐like ZnS.
Image processing tools for morphological analysis of nanoscale objects
Authors: Arroyo Carlos , Debut Alexis , Vaca Andrea , Kumar Brajesh , Cumbal Luis
Published: December 2016

In this work, we have developed a fast, reliable and unbias algorithm to analyze size distributions and morphological properties of nanoscale images taken by Transmission Electron Microscopy. As the physicochemical properties of nanostructures strongly depend on their size, shape and surface characteristics, it is of great importance to have access to a set of reliable tools to quantify them. Our image processing process is subdivided into three major subroutines: image preprocessing, image analysis and results interpretation. Several algorithms are used to adjust the image contrast as the adapthisteq function based on the contrast‐limited adaptive histogram equalization (CLAHE) method. A segmentation procedure, based on watershed transformation, has been implemented and tested. Introducing a simple geometrical criteria the software is able to distinguish between spherical, triangular and hexagonal shapes. The sphericity, roundness and roughness are also quantified. Figure 1 and 2 show the application of the software for different examples. We demonstrate that it is possible to distinguish between alive and dead bacteria by looking at the roundness, surface roughness and the ratio between the 2D projection area of the bacteria and the bounding box area enclosing the bacteria. For the case of nanoparticles, using the fractal dimension, we can predict the reactivity of iron nanoparticles used for environmental remediation
.
Status of the
SALVE
‐microscope:
Cc
‐correction for atomic‐resolution
TEM
imaging at
20kV
Authors: Linck Martin , Hartel Peter , Uhlemann Stephan , Kahl Frank , Müller Heiko , Zach Joachim , Biskupek Johannes , Niestadt Marcel , Kaiser Ute , Haider Max
Published: December 2016

With the goal to enable atomic resolution TEM observations on beam sensitive materials the SALVE project had been initiated to develop a dedicated low‐voltage TEM that is corrected for both, spherical and chromatic aberration [1,2].

The centerpiece of the SALVE III microscope is a new quadrupole‐octupole Cc‐Cs‐corrector by CEOS that is based on the so‐called Rose‐Kuhn‐Design [3,4]. The corrector is incorporated into a cubed FEI Titan Themis TEM and has been aligned for five accelerating voltages in the range from 20 to 80kV.

During design of the corrector special care had to be taken to prevent the resolution‐limiting effect of thermal magnetic field noise (Johnson‐Nyquist noise) that causes an image spread and limits the information transfer in Cc‐corrected electron microscopes [5]. As seen in Figure 1(a), these measures have been very successful in that for all desired high‐tensions the finally achieved resolutions exceed the 50mrad milestone. Figure 1(b) exemplarily demonstrates the achieved information limit on a purely amorphous 2nm tungsten sample at an accelerating voltage of 20kV. For the two shown perpendicular directions the Young's fringes significantly surpass the 50mrad aperture. In order to “use” the transferred information in a proper way, the phase plate, i.e. the aberration function, has to be well‐controlled beyond the 50mrad‐angle. This requires accurate control over axial aberrations up to including 5th order, and ‐for a considerable field of view‐ access to off‐axial aberrations. The aberration measurement in Figure 1(c) demonstrates that all unround axial aberrations as well as the off‐axial aberrations can be tuned sufficiently small. At the same time, the round aberrations can be adjusted for a suitable phase contrast transfer function (indicated in green color). Consequently, as shown in Figure 1(d) even at 20kV atomic resolution imaging becomes reality.

The chromatic aberration causes inelastically scattered electrons, i.e. electrons of lower energy, to be focused much stronger. This effect is compensated in the Cc‐corrected instrument. Figure 1(e) compares the energy‐dependent defocus effect of a Cc‐uncorrected TEM (red line, Cc=1.45mm) and the SALVE microscope (measurements: black dots; 3rd order fit: dashed line) at 20kV. While the gradient of the Cc‐uncorrected case is too steep to be distinguished from the axis of the ordinate in the magnified area, the SALVE instrument is capable to image a 20eV window with defocus changes of only 2nm. This will enable new imaging modes such as high‐resolution EFTEM at very low voltages. [6]
Multidimensional Analysis of Local Compositional and Valence Fluctuations in the Model Complex Oxide
La2MnNiO6
Authors: Spurgeon Steven , Du Yingge , Droubay Timothy , Devaraj Arun , Sang Xiahan , Longo Paolo , Yan Pengfei , Kotula Paul , Shutthanandan Vaithiyalingam , Bowden Mark , LeBeau James , Wang Chongmin , Sushko Peter , Chambers Scott
Published: December 2016

Propelled by rapid advances in synthesis, characterization, and computational modeling, materials science is fast progressing toward a “materials‐by‐design” paradigm. While we can envision a very large number of materials combinations, we are unable to synthesize them in practice because existing characterization and modeling approaches fail to capture the inherent complexities of such systems. This shortcoming is amplified by the fundamental disconnect between highly local and volume‐averaged structure‐property models resulting from electron microscopy and X‐ray diffraction investigations, respectively. Here we show how complementary analysis techniques can reveal previously overlooked local compositional and valence fluctuations around secondary phases in an oxide thin film, yielding powerful new insight into low‐pressure thin film synthesis. We explore the model complex oxide, La2MnNiO6 (LMNO), which possesses a hierarchy of structural, chemical, and magnetic ordering across multiple length scales. This material shows great promise for next‐generation spintronics and thermoelectrics, but its implementation is hindered by a poor understanding of the underlying structure that governs its macroscale magnetic performance. Using aberration‐corrected scanning transmission electron microscopy (STEM) and energy‐dispersive X‐ray spectroscopy (STEM‐EDS), we confirm the onset of cation ordering upon annealing; however, three‐dimensional composition mapping using atom probe tomography (APT) reveals a fine distribution of NiO secondary phases, as shown in Figure 1. Electron energy loss spectroscopy (STEM‐EELS) mapping of the chemical environment surrounding these particles shows significant fine structure changes, indicating a reduction in Mn valence, as shown in Figure 2. We consider these results in light of
ab initio
calculations, which show that the NiO phase and a transition region with reduced Mn valence is an inevitable result of low‐oxygen pressure growth processes that are commonly used in fabrication of complex oxide heterojunctions. We argue that kinetic limitations on the reincorporation of NiO nuclei “locks” them into the film structure during synthesis; the resulting nanoscale network disrupts the long‐range ferromagnetic ordering of the matrix, degrading macroscale magnetic properties. This array of experimental and theoretical techniques allows us to better understand the relationship between structure and magnetic properties, illustrating the need for a correlative, multidimensional approach to thin film characterization.
Measuring Charge Distribution in Nanoscale Magnesium Aluminate Spinel by Electron Energy‐Loss Spectroscopy and Electron Holography
Authors: Halabi Mahdi , Kohn Amit , Hayun Shmuel
Published: December 2016

Charge distribution resulting in the formation of a space charge zone (SCZ) in ionic materials has a critical role on functional properties [1]. Even though significant advances in theoretical models have been accomplished, experimental evidence in nanoscale granular materials is indirect.

Here, we investigated the distribution of cations and defects on the formation of a SCZ in a nanoscale granular model system of non‐stoichiometric MgO•nAl
2
O
3
(MAS, n= 0.95 and 1.07). The SCZ was investigated experimentally by electron energy‐loss spectroscopy (EELS) and off‐axis electron holography (OAEH).

EEL spectra were collected along directions perpendicular to grain boundaries (GB's), from which the magnesium‐to‐aluminum relative cation concentrations were calculated, as presented in Fig.1. We found that regardless of annealing processes, the vicinity of GB's of the Mg rich spinel has excess Mg
+2
cations while the vicinity of GB's of the Al rich spinel has excess of Al
+3
cations. Additionally, the cation distribution shows strong dependency on the grain size. For non‐stoichiometric MAS, cation concentration is proportional to the defect concentration, because deviation from stoichiometry results in adjacent defects that compensate for the electric charge [2, 3, 4]. In both materials, the cation distribution is inhomogeneous for grains smaller than 40 nm. For larger grains, the defect concentration approaches the bulk value at the center of the grain. Furthermore, excess of Mg (Al) cations at the vicinity of the GB decreased with increase of grain size. Maier
et al.
[1] calculated that for grain size at the scale of the Debye length (estimated at 9nm for non‐stoichiometric MAS studied here [7]), the GC is no longer electrically neutral, instead influenced by accumulation or depletion of charge at the boundaries.

Due to the lack of accurate values for defect formation energy [5, 6], we applied OAEH to measure directly the electrostatic charge distribution in nano‐sized MAS. We show that charge distribution and the buildup of electrostatic potential between GB and core are linked to the spatial distribution of defects rather than the overall composition of MAS (Fig. 2). At the vicinity of GB's, excess Mg
+2
or Al
+3
cations accumulate depending on the composition, the magnitude of which increases with decreasing grain size. Indeed, the potential distributions show the relation between the excess cation species, grain size and the Debye length, in agreement with theoretical models [1].
Transmission electron microscopy investigation of
Mg‐Zn
alloy processed by severe plastic deformation
Authors: Němec Martin , Gärtnerová Viera
Published: December 2016

Magnesium alloys possess great potential owing to advantageous properties in various fields such as structural applications, electronic devices or hydrogen and thermal energy storage. Use of Mg alloys for biomedical implants also attracted enormous attention recently. Properties of Mg and its alloys can be significantly improved via design of alloys with precipitation hardening effect and grain refinement using severe plastic deformation (SPD) techniques. Mg‐Zn based alloys are among the most important Mg alloys and have been investigated for more than a hundred years. With a most recent development of various SPD techniques, there is a number of processing routes which may significantly improve the alloys properties. However, fundamental knowledge about an impact of SPD on microstructure of these alloys at nanoscale is insufficient or missing in many cases.

In this work, deformation behaviour of an α‐Mg matrix and Mg‐Zn intermetallic particles in the Mg‐12wt.% Zn alloy subjected to equal‐channel angular pressing with applied back pressure (ECAP‐BP) is characterized using transmission electron microscopy (TEM) techniques at nanoscale. Magnesium with 99.9% purity and an appropriate amount of high‐grade Zinc were melted in a graphite crucible under an Ar atmosphere. The subsequent thermal treatment consisted of annealing at 320°C for 20 hours and quenching into warm water. The material was then processed by ECAP (4 passes via Bc route) with applied BP of ~400 MPa to prevent cracking during processing. The processing temperature was gradually decreasing from 200 °C to 185 °C, 170 °C and 155 °C for 1st, 2nd, 3rd and 4th ECAP‐BP pass, respectively, to obtain ultra‐fine grained structure.

Following TEM techniques are employed for micro‐ and nano‐ structural analysis: Bright‐field (BF) imaging; selected area electron diffraction (SAED); high‐resolution transmission electron microscopy (HRTEM); high‐angle annular dark field ‐ scanning transmission electron microscopy (HAADF‐STEM) imaging; and electron energy‐loss spectroscopy (EELS). All techniques were performed using an FEI Tecnai TF20 X‐twin, which operated at 200 kV.
The atomic lensing model: extending
HAADF STEM
atom counting from homogeneous to heterogeneous nanostructures
Authors: van den Bos Karel H W , De Backer Annick , Martinez Gerardo T , Winckelmans Naomi , Bals Sara , Nellist Peter D , Van Aert Sandra
Published: December 2016

Counting the number of atoms in each atomic column from different viewing directions has proven to be a powerful technique to retrieve the 3D structure of homogeneous nanostructures [1]. In order to extend the atom counting technique to heterogeneous materials, this work presents a new atomic lensing model facilitating both atom counting and 3D compositional determination in such materials.

In the quantitative evaluation of high angle annular dark field scanning transmission electron microscopy (HAADF STEM) images the so‐called scattering cross‐section (SCS) has proven to be a successful performance measure [1–3]. Its monotonic increase with thickness can be used to count the number of atoms in homogeneous materials with single atom sensitivity [4]. However, for heterogeneous materials, small changes in atom ordering in the column can change the SCS (Fig. 1), significantly complicating atom counting. This depth dependency requires a quantitative method to predict SCSs of all possible 3D column configurations, already more than 2 million for a 20 atoms thick binary alloy. Image simulations can provide this information, but the amount of required simulations makes it an impossible task in terms of computing time. Therefore, a new atomic lensing model is developed based on the principles of the channelling theory [5], where each atom is considered to be an electrostatic lens resulting in an extra focussing effect on the probe. This model allows one to predict the SCSs of mixed columns based on the lensing factors of the individual atoms in monotonic atomic columns. As compared to a linear model neglecting channelling, this new approach leads to a significant improvement in the prediction of SCSs which is not restricted to the number of atom types (Fig. 2) and can be used for a wide range of detector angles (Fig. 3).

The power of the atomic lensing model to accurately predict SCSs enables one to extend the atom counting technique to heterogeneous materials. Here, simulated SCSs can be matched to the measured experimental SCSs. Next, the 3D structure can be determined by combining atom counts from different viewing directions. In this presentation, this technique will be demonstrated on experimentally recorded images of an Au@Ag nanocrystal. Another advantage of the atomic lensing model is its ability to accurately predict the atom ordering in the column from experimental SCSs (Fig. 1). Therefore, it opens up the possibility to extract 3D information from a single image. This ability will be presented on a simulated image of an Au@Ag nanorod.

In conclusion, a new atomic lensing model is developed which is of great importance for extending the atom counting technique from homogeneous to heterogeneous nanostructures.