bluuebunny/crossref_metadata_2025 huggingface dataset:
Investigation of microstructure and thermophysical properties of Morasko iron meteorites
Authors: Szurgot M. , Rożniakowski K. , Wojtatowicz T. W. , Polański K.
Published: July 2008

Chemical etching and electron microscopy were used to reveal and characterize minerals and microstructure of four samples of Morasko iron meteorites. All important iron meteorite minerals such as: kamacite, taenite, schreibersite, rhabdite, troilite, and graphite, as well as typical of iron meteoritc structures: Widmanstätten patterns and Neumann bands have been revealed. This implies that all the samples represent the extraterrestrial materials. Apart from similarities, differences in microstructure of various samples have also been noted, and this nonuniformity is expected for this type of material. To characterize the physical properties of Morasko meteorites, density and thermophysical properties have been chosen to compare with the properties of terrestrial materials of similar composition. Thermal diffusivity and specific heat capacity were measured by the laser flash method. Thermal conductivity was calculated on the basis of measured parameters. For the Morasko meteorites, the thermal diffusivity of various samples is in the range (7–19)·10–6m2/s, and the thermal conductivity (25–67) W/m·K at room temperature. Specific heat capacity in the temperature range between 163 and 303 K increases from 50 to 590 J/kg·K, and is equal to 478 J/kg·K at 293 K, but various samples have their heat capacity in the range (440–596) J/kg·K at room temperature. Thermal diffusivity, thermal conductivity and specific heat capacity of Morasko meteorites are within the range of values attained in terrestrial metals: iron, nickel, steels and iron alloys. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
The crystallization of lysozyme in the system of ionic liquid [BMIm][BF4]‐water
Authors: Li Xinxin , Xu Xiaodong , Dan Yuanyuan , Feng Jing , Ge Lan , Zhang Milin
Published: July 2008

Lysozyme crystallization was conducted in the ionic liquid (IL) 1‐butyl‐3‐methylimidizolium tetrafluoroborate ([BMIm][BF4]) with different buffer/IL proportions. It was found that the addition of [BMIm][BF4] could promote the crystallization process, during which more lager single crystals with controllable morphologies could be obtained due to the manageable crystal growth velocity. A probable explanation was proposed based on the influence of the ionic polarization and kinetics in the lysozyme crystallization. Moreover, the transform in coordination number and the relative growth rate of different crystal faces were discussed. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Hydrothermal growth of ZnS microspheres and their temperature‐dependent luminescence properties
Authors: Zhang Li , Yang Liangbao
Published: July 2008

ZnS microspheres have been synthesized in large scale by a hydrothermal route. The influence of reaction time on the phase constitution is studied. The evolution process from cubic phase to hexagonal phase is showed with prolonging reaction time. It is observed that the luminescence intensity of the same sample decreases dramatically with increasing the temperature. At the same time, the Luminescence intensity of ZnS particles increases with prolonging the reaction time. The luminescence intensity of the particles is affected by the reaction time and temperature. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Recent Developments in Solid‐State Dye‐Sensitized Solar Cells
Authors: Yum Jun‐Ho , Chen Peter , Grätzel Michael , Nazeeruddin Mohammad K.
Published: July 2008

The dye‐sensitized solar cell, developed in the 1990s, is a non‐conventional solar technology that has attracted much attention owing to its stability, low cost, and device efficiency. Power‐conversion efficiencies of over 11 % have been achieved for devices that contain liquid electrolytes, whereas solid‐state devices that do not require a liquid electrolyte display an overall efficiency of 5 %. Improvement of the efficiency of solid‐state dye‐sensitized solar cells requires optimization of their various components, such as the hole‐transport material, sensitizer, mesoporous TiO2 film, and the blocking layer. This Minireview highlights the current state of the art and future directions of solid‐state dye‐sensitized solar cell technology.
Catalytic Conversion of Biomass: Challenges and Issues
Authors: Gallezot Pierre
Published: July 2008

There are strong incentives to develop the production of fuels, chemicals and materials from biomass. However, the extensive use of biomass for industrial production, particularly for biofuels which involves high tonnages, raises environmental and ethical issues that may throw some doubts on the sustainability of these processes. The processing cost of biomass must be decreased by designing new processing routes and catalytic systems because those employed for hydrocarbons are not adapted to the molecular structure of biomolecules. To avoid competition with food supply, lignocellulosic feedstocks should be used rather than traditional agricultural crops particularly for biofuel production. Life‐cycle assessment, which takes into account all the inputs and outputs of a process/product, should be carried out to evaluate the environmental impact of processes and used as a decision‐making tool for product development.
Heterogeneous Multifunctional Catalysts for Tandem Processes: An Approach toward Sustainability
Authors: Felpin François‐Xavier , Fouquet Eric
Published: July 2008

The development of sustainable organometallic chemistry is one of the many challenges that chemists must address to solve environmental issues. Until now, the classical approach was to develop highly selective homogeneous catalysts for a single transformation. However, a new area of research focuses on the execution of two or more reactions in the same vessel using heterogeneous multitask catalysts. This approach results in a reduced number of operations leading to time and cost benefits. Moreover, owing to the scarcity of natural resources and the recent dramatic cost increase of these resources and metals, the development of recyclable heterogeneous catalysts is urgent. This Minireview focuses on the latest developments in tandem reactions promoted by heterogeneous multitask catalysts.
Abnormal mitosis in hypertetraploid cells causes aberrant nuclear morphology in association with H2O2‐induced premature senescence
Authors: Ohshima Susumu
Published: July 2008

Aberrant nuclear morphology, such as nuclei with irregular shapes or fragmented nuclei, is often observed in senescent cells, but its biological significance is not fully understood. My previous study showed that aberrant nuclear morphology in senescent human fibroblasts is attributable to abnormal mitosis in later passages. In this study, the production of abnormal nuclei in association with premature senescence was investigated. Premature senescence was induced by brief exposure of human fibroblasts to hydrogen peroxide (H2O2), and mitosis was observed by time‐lapse microscopy. In addition, cell cycle and nuclear morphology after exposure to H2O2 were also analyzed using a laser scanning cytometer. Time‐lapse analysis revealed that the induction of premature senescence caused abnormal mitoses, such as mitotic slippage or incomplete mitosis, especially in later days after H2O2 exposure and often resulted in abnormal nuclear morphology. Analysis by laser scanning cytometer showed significantly higher frequency of abnormal cells with deformed nuclei and abnormal mitotic cells with misaligned chromosomes in a hypertetraploid subpopulation. These results suggest that unstable hypertetraploid cells, formed in association with H2O2‐induced premature senescence, cause abnormal mitosis that leads to aberrant nuclear morphology. © 2008 International Society for Advancement of Cytometry
Comparison of PAX‐2, RCC antigen, and antiphosphorylated H2AX antibody (γ‐H2AX) in diagnosing metastatic renal cell carcinoma by fine‐needle aspiration
Authors: Wasco Matthew J. , Pu Robert T.
Published: July 2008

Diagnosing metastatic renal cell carcinoma (RCC) by fine‐needle aspiration (FNA) can be challenging. Existing antibodies supporting a diagnosis of RCC, including CD10 and RCC‐Ma, have problems with specificity and interpretation. In this report, we evaluate the use of two newer immunostains, PAX‐2 and γ‐H2AX, which to our knowledge have not been studied in FNA material, in the diagnosis of metastatic RCC and in comparison with RCC‐Ma. 29 cases of metastatic RCC were identified as well as a TMA of an additional 30 RCC cases. In the case cohort, RCC‐Ma in a membranous pattern of staining identified 15/27 (56%) metastatic RCC, although interpretation was made difficult in many cases due to focality of staining and non‐specific cytoplasmic staining. PAX‐2 stained 23/29 (79%) of tumors in a nuclear stain, most strongly. Gamma‐H2AX stained 19/26 (73%) of metastatic RCC strongly in a nuclear stain. In the TMA, strong, diffuse nuclear staining with γ‐H2AX was present in 22/30 RCC (73%). If weak staining was also included as positive, 26/30 (87%) were positive. PAX‐2 stained RCC TMA with a lower percentage at 56%, including weaker staining intensity. Both PAX‐2 and γ‐H2AX demonstrated patchy staining of normal renal tubules, PAX‐2 to a greater extent. Both PAX‐2 and γ‐H2AX are sensitive markers for the diagnosis of metastatic RCC, with improved ease of interpretation when compared with RCC‐Ma. A combination of all 3 markers identified 87% of cases, and failure to stain for both PAX‐2 and γ‐H2AX suggests against, but does not disprove, a diagnosis of RCC. Diagn. Cytopathol. 2008; 36: 568–573. © 2008 Wiley‐Liss, Inc.
Paracoccidioides brasiliensis in a liquid‐based Papanicolaou test from a pregnant woman: Report of a case
Authors: Alsharif Mariam , Martin Andrea U. , Shelton Jack B. , Pambuccian Stefan E.
Published: July 2008

With the exception of Candida species, fungal organisms are rarely encountered in the Papanicolaou test and, when encountered, usually represent contaminants rather then infections. We present the case of a healthy 29‐year‐old pregnant female, gravida 1, para 0, who presented for her first prenatal visit at 12‐week gestation and had many large fungal‐like elements with a distinct budding pattern of multiple narrow‐based buds resembling a “ship's‐wheel” identified in her routine liquid‐based Papanicolaou test. Based on its characteristic appearance in the Papanicolaou test and the hematoxylin and eosin, periodic acid Schiff and Gomori's methenamine silver stains performed on the cell block made from the residual sample, the fungus was diagnosed as “consistent with Paracoccidioides.” This is the second reported case of Paracoccidioides presenting in a Papanicolaou test and shows that this organism may rarely involve the uterine cervix in the absence of clinical systemic disease. Diagn. Cytopathol. 2008; 36: 557–560. © 2008 Wiley‐Liss, Inc.
Imprint cytology of high‐grade immature ovarian teratoma: A case report, literature review, and distinction from other ovarian small round cell tumors
Authors: Ramalingam Preetha , Teague Daniel , Reid‐Nicholson Michelle
Published: July 2008

Immature ovarian teratoma (IOT) is a rare and aggressive malignant neoplasm characterized by immature neural tissue. The cytomorphologic features have only rarely been described. We herein describe an additional case and review the literature regarding this entity. To the best of our knowledge, this is the first reported case with imprint cytology. A 35‐year‐old woman presented with a pelvic mass which was resected and sent for frozen section evaluation. Imprint smears and frozen section of the mass were diagnostic of IOT. IOT has diagnostic cytologic features which show complete concordance with histology. Differential diagnoses include other small round cell neoplasms such as ovarian neuroblastoma, small cell carcinoma of hypercalcemic type, primitive neuroectodermal tumor, Wilm's tumor, desmoplastic small round cell tumor, and Non‐Hodgkin lymphoma. Distinguishing IOT from these tumors can be challenging however if diligent morphologic study and/or ancillary studies are performed accurate diagnosis is possible. Diagn. Cytopathol. 2008; 36: 595–599. © 2008 Wiley‐Liss, Inc.
Cytomorphology of lymphoepithelioma‐like carcinoma of the urinary bladder: Report of two cases
Authors: Cai Guoping , Parwani Anil V.
Published: July 2008

Lymphoepithelioma‐like carcinoma (LELC) of the urinary bladder is a rare variant of high‐grade urothelial carcinoma. Here, we report urine cytologic findings in two cases of this rare entity, the diagnosis of which was confirmed by histopathological examination of the resected tumors. The cytomorphologic features included large tumor cells with high nuclear to cytoplasmic ratios, vesicular chromatin, and prominent nucleoli, presented as single cells or intermixed with inflammatory cells. The differential diagnosis included otherwise typical high‐grade urothelial carcinoma, reactive urothelial cells and rarely large cell lymphoma. The rarity of the tumor cells may impose a diagnostic challenge in urine specimen. Diagn. Cytopathol. 2008; 36: 600–603. © 2008 Wiley‐Liss, Inc.
Cytological features of myxoid adrenocortical adenoma with a pseudoglandular component: A case report with differential diagnostic considerations
Authors: Ishida Mitsuaki , Yoshida Keiko , Miyamoto Keiko , Iwai Muneo , Miyahira Yoshimitsu , Kushima Ryoji , Okabe Hidetoshi
Published: July 2008

Myxoid adrenocortical tumors are extremely rare neoplasms with only nine adenomas and eleven carcinomas reported in the literature. They occasionally have a pseudoglandular component resembling metastatic mucinous adenocarcinoma in the adrenal gland. However the cytological features of this unusual tumor have not been previously described. We report here the first cytopathological study of a myxoid adrenocortical adenoma with a pseudoglandular component, contributing especially to the differential diagnosis from metastatic mucinous adenocarcinoma. Two major cytopathological features distinguishing myxoid adrenocortical adenoma from metastatic mucinous adenocarcinoma in the adrenal gland are: (1) the myxoid material is found only in the extracellular space, and not in the cytoplasm; and (2) nuclei are usually located in the central portion of the cytoplasm, and not compressed to the periphery. Careful observation of these cytological features and positive immunoreactivity to Melan A, alpha‐inhibin and synaptophysin can lead to the correct diagnosis. Diagn. Cytopathol. 2008; 36: 576–580. © 2008 Wiley‐Liss, Inc.
Intranuclear cytoplasmic inclusion is a significant diagnostic feature for the differentiation of lobular endocervical glandular hyperplasia from minimal deviation adenocarcinoma of the cervix
Authors: Hashi Akihiko , Yuminamochi Tsutomu , Xu Jia‐Ying , Kondo Tetsuo , Katoh Ryohei , Hoshi Kazuhiko
Published: July 2008

Lobular endocervical glandular hyperplasia (LEGH) is a cervical lesion with pyloric gland metaplasia. Minimal deviation adenocarcinoma (MDA) is an extremely well differentiated form of endocervical adenocarcinoma (AC). To date, it is difficult to differentiate LEGH from MDA because they share similar clinical, radiological, and immunohistochemical features. Furthermore, the cytological features of LEGH and MDA have not been well defined. In the present study, we describe the cytological features of LEGH and MDA. We reviewed 24 cases of LEGH (18 pure and six mixed forms) and four MDA cases of the cervix. A total of 40 cytologic smears from 28 patients were reviewed. Abundant yellow mucin was frequently present in both LEGH and MDA; however, an INCI was found in 22 of the 24 LEGH cases and it was not found in either MDA or adenocarcinoma cells associated with LEGH. Neither cell atypia nor architectural distortion was observed in LEGH. In MDA, slight cellular atypia, three dimensional, irregular cell clustering, and prominent nucleoli were observed. The presence of an INCI is a good parameter for the diagnosis of LEGH. Cytology is an effective aid in the differentiation of LEGH from MDA. Diagn. Cytopathol. 2008; 36: 535–544. © 2008 Wiley‐Liss, Inc.
Unconscious processing of Web advertising: Effects on implicit memory, attitude toward the brand, and consideration set
Authors: Yoo Chan Yun
Published: July 2008

Consumers have become increasingly savvy about technology in recent years, and many of them ignore Web ads during online activities. In this context, measuring advertising effects based on the traditional cognitive models of information processing may undervalue the effectiveness of Web ads. This study experimentally examined the effects of unconscious processing of Web ads by manipulating the level of attention paid to the ad (directed vs. non-directed attention). Online advertisers should be encouraged by the findings of this study. The results suggest that, upon exposure to Web ads, consumers experience priming caused by implicit memory and build a more favorable attitude toward the advertised brand regardless of the levels of attention they paid to the advertisements. Furthermore, those who unconsciously processed Web ads did not remember seeing the ad explicitly, but they were more likely to include the advertised brand in the consideration set than those who had no exposure.
An empirical analysis of inter-acquisition time of free online content
Authors: Qiu Guiyou , Papatla Purushottam
Published: July 2008

Free, content-oriented Web sites depend on advertising revenues that are based on the number of visitors to the site. To induce visitors to acquire information quickly, these sites present information items according to their popularity. We empirically examine two key determinants of a visitor's inter-acquisition time (popularity and the number of information items previously acquired by the visitor) using a hazard model estimated from data obtained from del.icio.us, a social bookmarking site. The results indicate that inter-acquisition times are longer for heavy users and for less popular information items. The results are relevant for other free content-providing sites such as cnet.com and music.yahoo.com .
Beyond trial: Consumer assimilation of electronic channels
Authors: Johnson Devon S.
Published: July 2008

This paper explores the assimilation of electronic channels into consumers'routines. It proposes that consumer learning orientation for the product/service and the efficiency realized from channel use are essential determinants of post-trial assimilation and that assimilation reduces information ambiguity and improves consumers’ sense of identity with the firm. These relationships are tested using data from a survey of online banking customers. The study reveals that consumer efficiency and learning orientation influence assimilation more strongly than some other determinants of consumer trial and that assimilation improves consumers’ understanding of the service and facilitates a greater sense of identity with the firm. Theoretical implications are discussed and suggestions are presented on how managers can increase the rate of customer electronic channel assimilation and how to take strategic advantage of this.
Diabetes classification: grey zones, sound and smoke: Action LADA 1
Authors: Leslie R. D. G. , Kolb H. , Schloot N. C. , Buzzetti R. , Mauricio D. , De Leiva A. , Yderstraede K. , Sarti C. , Thivolet C. , Hadden D. , Hunter S. , Schernthaner G. , Scherbaum W. , Williams R. , Pozzilli P.
Published: July 2008

Diseases gain identity from clinical phenotype as well as genetic and environmental aetiology. The definition of type 1 diabetes is clinically exclusive, comprising patients who are considered insulin dependent at diagnosis, whilst the definition of type 2 diabetes is inclusive, only excluding those who are initially insulin dependent. Ketosis‐prone diabetes (KPD) and latent autoimmune diabetes in adults (LADA) are each exclusive forms of diabetes which are, at least initially, clinically distinct from type 2 diabetes and type 1 diabetes, and each have a different natural history from these major types of diabetes.

KPD can be diagnosed unequivocally as diabetes presenting with the categorical clinical feature, ketoacidosis. In contrast, LADA can be diagnosed by the co‐occurrence of three traits, not one of which is categorical or exclusive to the condition: adult‐onset non‐insulin‐requiring diabetes, an islet autoantibody such as glutamic acid decarboxylase autoantibodies (GADA) orcytoplasmicislet cell autoantibodies (ICA), and no need for insulin treatment for several months post‐diagnosis. But while some would split diabetes into distinct subtypes, there is a strong case that these subtypes form a continuum of varying severity of immune and metabolic dysfunction modified by genetic and non‐genetic factors. This article discusses the nature of disease classification in general, and KPD and LADA in particular, emphasizing the potential value and pitfalls in classifying diabetes and suggesting a need for more research in this area. Copyright © 2008 John Wiley & Sons, Ltd.
InN@SiO2 Nanomaterials as New Blue Light Emitters
Authors: Munusamy Prabhakaran , Mahalingam Venkataramanan , van Veggel Frank C. J. M.
Published: July 2008

In this article we report blue photoluminescence (≈ 450 nm) from InN@SiO2 nanomaterials. The InN@SiO2 nanomaterials were prepared by a simple precipitation reaction followed by a solid‐state reaction. Various control experiments demonstrate that the interface between the InN and SiO2 seems to play a crucial role in the origin of the blue emission from the InN@SiO2 nanomaterial. The InN@SiO2 nanomaterial was characterized by using analytical methods such as TEM, XRD, Raman, XPS, and photoluminescence spectroscopy, which confirmed the existence of InN on SiO2 with a small excess of nitrogen relative to indium.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
MCM‐41 Derivatised with Pyridyl Groups and Its Use as a Support for Luminescent Europium(III) Complexes
Authors: Bruno Sofia M. , Coelho Ana C. , Ferreira Rute A. S. , Carlos Luís D. , Pillinger Martyn , Valente Anabela A. , Ribeiro‐Claro Paulo , Gonçalves Isabel S.
Published: July 2008

An organic–inorganic hybrid ligand silica was prepared by reaction of the ordered mesoporous silica MCM‐41 with 3‐triethoxysilylpropyl 4‐pyridylacetamide. Elemental analysis indicated that a pyridyl group loading of 0.93 mmol g–1 was achieved. The derivatised material was further characterised by powder X‐ray diffraction, N2 adsorption, thermogravimetric analysis, FTIR and Raman spectroscopy, and 13C and 29Si CP MAS NMR spectroscopy. Pyridyl‐functionalised MCM‐41 (L″) was treated with chloroform solutions of lanthanide tris‐β‐diketonate complexes Ln(nta)3(H2O)2 [Ln = Eu, Gd; nta = 1‐(2‐naphthoyl)‐3,3,3‐trifluoroacetonate] to give the surface‐bound monosubstituted species Ln(nta)3(H2O)(L″). The residual coordinated water molecules were subsequently replaced by pyridine (py) or methyl phenyl sulfoxide (mpso) to give immobilised Ln(nta)3(py)(L″) and Ln(nta)3(mpso)(L″) species. Photoluminescence studies were carried out at room temperature and 14 K. The emission spectra of the Eu‐modified materials were dominated by the typical Eu3+ red lines ascribed to transitions between the 5D0 excited state and the ground multiplet (7F0–4), and only very weak or negligible emission from the organic ligands are observed. Variation of the excitation wavelength confirmed that all of the Eu3+ ions occupied the same average local environment within each sample. By comparison with the photoluminescence data for the nonsupported Eu(nta)3(py)2 and Eu(nta)3(mpso)2 complexes, it is shown that the interaction between the host and guest has a strong effect on the excited states of the organic ligands; Eu3+ sensitisation occurs exclusively through the ligands rather than by direct intra‐4f6 excitation.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
Magnetic Coupling and Anisotropy in a Series of Mixed Chain Charge‐Transfer Salts [M(Cp*)2][M′(tds)2] (M = Fe, Mn, Cr; M′ = Ni, Pt)
Authors: Rabaça Sandra , Vieira Bruno J. C. , Meira Rui , Santos Isabel C. , Pereira Laura C. J. , Duarte M. Teresa , da Gama Vasco
Published: July 2008

The preparation of new charge‐transfer (CT) salts based on the decamethylmetallocenium donors (D), [M(Cp*)2] (M = Mn, Cr), and on the bis[bis(trifluoromethyl)ethylene diselenolato]metalate(III) acceptors (A), [M′(tds)2] (M = Ni, Pt), yielded four new members of the family of CT salts [M(Cp*)2][M′(tds)2] {M/M′ = Fe/Ni (1), Fe/Pt (2), Mn/Ni (3), Mn/Pt (4), Cr/Ni (5), Cr/Pt (6)}. Their crystal structures consist of anarrangement of parallel mixed chains, DADADA, with short D–A contacts and large interchain separations. The CT salts 1–5 are isostructural and 6 shows minor differences in the interchain arrangements. The analysis of the intermolecular contacts, in the framework of the McConnell I model, provides a fair interpretation of the magnetic coupling. The behavior of these salts is dominated by the ferromagnetic (FM) D–A intrachain interactions. Coexisting weaker antiferromagnetic (AF) interchain couplings induce AF transitions in 2, 3, 4, and 6, with TN = 3.3, 2.1, 5.8, and 5.2 K, respectively. The intrachain coupling and the TN values of the CT salts based on the [M(Cp*)2] (M = Fe, Mn) donors (1, 2, 3, and 4) were found to be in good agreement with those predicted by the mean field model. Compounds 5 and 6 exhibit weaker intrachain coupling and lower critical temperatures than those predicted by that model, which is attributed to weaker D–A interactions. The study of the low temperature behavior of the salts 3, 4, and 6 allowed the disclosure of the effect of the magnetic anisotropy of the donors. The CT salts based on highly anisotropic donors, such as 3 and 4, show metamagnetic (MM) behavior, with phase diagrams that include a paramagnetic (PM) and an AF phase, as previously observed for 2. In the phase diagram of 6, where the [Cr(Cp*)2] donor does not show magnetic anisotropy, a spin‐flop (SF) phase is present in addition to the PM and AF phases. This is the first time an SF phase was observed in [M(Cp*)2]‐based CT salts. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
Checking the Route to Cluster Helicates
Authors: Bermejo Manuel R. , González‐Noya Ana M. , Martínez‐Calvo Miguel , Pedrido Rosa , Romero María J. , Vázquez López Miguel
Published: July 2008

The aim of the work described here was to test the general applicability of our recently reported route to cluster helicates and to carry out a systematic study to relate the structural and coordinative properties of the organic strands with the microarchitectures of the resulting cluster helicates. Nine new ZnII, CuI and AgI complexes were prepared from three Schiff base ligands [H2La: bis(4‐methyl‐3‐thiosemicarbazone)‐2,6‐diacetylpyridine; H2Lb: bis(4‐methyl‐3‐thiosemicarbazone)‐2,6‐diacetylbenzene; H2Lc: bis(4‐ethyl‐3‐thiosemicarbazone)‐2,6‐diacetylbenzene]. The experimental data confirm that AgI and CuI tetranuclear cluster helicates were obtained with a [M4(Lx)2] stoichiometry, and this finding demonstrates the general applicability of the synthetic route. The cluster helicates presented in this work were characterized for the first time in solution by NMR spectroscopy. In addition, six of the nine complexes were characterized by X‐ray diffraction studies, and three of them were found to be tetranuclear cluster helicates. A detailed study of these three crystal structures leads us to state that the changes introduced in the organic strands do not prevent the assembly of the tetranuclear cluster dihelicates, but they do affect the microarchitectures. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
Structure and Properties of NaBH4·2H2O and NaBH4 (Eur. J. Inorg. Chem. 20/2008)
Authors: Filinchuk Yaroslav , Hagemann Hans
Published: July 2008

The cover picture shows the crystal structure of sodium borohydride dihydrate, NaBH4·2H2O, determined from synchrotron diffraction on a single crystal. The European Synchrotron Radiation Facility (ESRF), shown in the lower left corner, provided the source of X‐rays. The BH4– anion has a nearly ideal tetrahedral geometry. By applying the systematic correction to the positions of hydrogen atoms seen by X‐rays, the geometry of the dihydrogen O–Hδ+···δ–H–B bonding was accurately characterized. The structure of anhydrous NaBH4 was also investigated by X‐ray diffraction on a single crystal. Vibrational properties of NaBH4·2H2O and related substances were studied by IR and Raman spectroscopy. Details are discussed in the article by Y. Filinchuk and H. Hagemann on p. 3127 ff.
The quality and volatile‐profile changes of camellia oil (Camellia oleifera Abel) following bleaching
Authors: Qizhi Long , Yonghui Huang , Haiyan Zhong , Bedgood Danny R. , Prenzler Paul D. , Robards Kevin
Published: July 2008

Bleaching is a necessary step in the production of refined camellia oil (Camellia oleifera Abel) since crude oil has a dark brown color, due to pigments extracted from the seed coat during pressing, which is unacceptable to consumers. In order to understand the quality change and oxidative state of camellia oil in the bleaching step, measurements of various quality parameters, i.e. peroxide value (POV), free fatty acids (FFA), UV absorbance, and the volatile profiles of crude and bleached oils, were carried out. The results showed that FFA, K270, and K232 increased, whereas POV decreased, with increase of the activated earth dosage of 0–4% and of bleaching time from 0 to 40 min at 110 °C. As the amount of activated earth was increased from 0 to 4% with bleaching at 110 °C for 30 min, various classes of volatile compounds increased in concentration: aldehydes (23.7 µg/g), alcohols (13.2 µg/g), esters (8.0 µg/g), alkenes (2.0 µg/g) and ketones (1.9 µg/g). Likewise, when bleaching was carried out at 110 °C with 3% activated earth and the bleaching time varied between 0 and 40 min, the concentrations of volatile compounds also increased: aldehydes (27.7 µg/g), alcohols (18.2 µg/g), esters (7.3 µg/g), ketones (3.2 µg/g) and alkenes (0.6 µg/g). These findings indicate that hydroperoxides in the oil were decomposed into lower‐molecular‐weight products in the process of bleaching and that the extent of this decomposition can be controlled by time and amount of activated earth.
The effect of malaxation temperature on the virgin olive oil phenolic profile under laboratory‐scale conditions
Authors: Parenti Alessandro , Spugnoli Paolo , Masella Piernicola , Calamai Luca
Published: July 2008

The relationship between olive paste malaxation temperature and the concentration of olive oil hydrophilic phenols (HP), i.e. simple phenols, secoiridoids and lignans, was investigated. Malaxation experiments were performed at laboratory scale for 45 min at 21, 24, 27, 30, 33 and 36 °C. A significant (p <0.05) increment of total phenols concentration was found with a maximum at 27 °C, whereas for higher temperatures (30–36 °C) a progressive decrement was observed. A similar pattern was recorded approximately for all the secoiridoid compounds, i.e. a quasi‐linear increment of concentrations with increasing temperature until 30 °C, followed by a marked decrease in correspondence with the higher malaxation temperature (33 and 36 °C). The amount of simple phenols increased linearly with increasing temperature and no decrements were observed up to the maximal temperature investigated (36 °C), while no significant differences were found for lignans. A small increment of peroxide values and total chlorophyll was recorded as a function of the increasing malaxation temperature, whereas no differences were observed in the free acidity. The results highlight that there is not a univocal relationship between HP concentration and malaxation temperature. An equilibrium between degradation (chemical and biochemical oxidation and hydrolysis) and transfer (partitioning) phenomena was hypothesized.
Lipid adsorption capacities of magnesium silicate and activated carbon prepared from the same rice hull
Authors: Taspinar Ozgul O. , Ozgul‐Yucel Sevil
Published: July 2008

This study is a comparison of the lipid adsorption capacities of synthetic magnesium silicate and activated carbon produced from rice hulls of the same origin. The lipids examined were the free fatty acids, diacylglycerols and monoacylglycerols of frying oils. Pure oleic acid, an unused sunflower frying oil and a used sunflower frying oil were used in the experiments. The produced adsorbents, magnesium silicate and activated carbon, have surface areas of 680 and 43 m2/g, respectively. The lipid adsorption capacity of the produced magnesium silicate was found as 644 mg polar compounds/g adsorbent and it is higher than the capacities of the industrial adsorbents, Magnesol XL and activated carbon. This value is only 368 mg polar compounds/g adsorbent for the activated carbon produced from the same‐origin rice hull.
Undecylenic acid: A valuable renewable building block on route to Tyromycin A derivatives
Authors: Van der Steen Marijke , Stevens Christian V. , Eeckhout Yves , De Buyck Laurent , Ghelfi Franco , Roncaglia Fabrizio
Published: July 2008

A key intermediate for the synthesis of Tyromycin A, a C‐20 tetrachlorodicarboxylic acid, was produced in six steps starting with the dimerization of methyl 10‐undecenoate which was obtained from a renewable resource, e.g. castor oil. The acyloin condensation product was then oxidized, transformed to the diene, followed by ozonization, chlorination and finally oxidation to the corresponding tetrachlorodicarboxylic acid.
Thermostability of genetically modified sunflower oils differing in fatty acid and tocopherol compositions
Authors: Marmesat Susana , Velasco Leonardo , Ruiz‐Méndez Maria Victoria , Fernández‐Martínez José María , Dobarganes Carmen
Published: July 2008

The objective of the study was to investigate the performance at frying temperature of a new sunflower oil with high content of oleic and palmitic acid (HOHPSO) and containing γ‐tocopherol as the most abundant natural antioxidant. HOHPSO either containing α‐ or γ‐tocopherol (HOHPSO‐α and HOHPSO‐γ, respectively) were obtained from genetically modified sunflower seeds and refined under identical conditions. The oil stability against oxidation, as measured by Rancimat at 120 °C, was much higher for the oil containing γ‐tocopherol, suggesting the higher effectiveness of γ‐tocopherol as compared to α‐tocopherol to delay oxidation. Experiments at high temperature (180 °C) simulating the conditions applied in the frying process clearly demonstrated that, for the same periods of heating, the oil degradation and the loss of natural tocopherol were significantly lower for the oil containing γ‐tocopherol. Comparison of different genetically modified sunflower oils with different fatty acid compositions confirmed that oil degradation depended on the fatty acid composition, being higher at a higher degree of unsaturation. However, the loss of tocopherol for a similar level of oil degradation was higher as the degree of unsaturation decreased. Overall, the results showed that HOHPSO‐γ had a very high stability at frying temperatures and that mixtures of HOHPSO‐α and HOHPSO‐γ would be an excellent alternative to fulfill the frying performance required by the processors and the vitamin E content claimed by the consumers.
J‐Based Analysis and DFT–NMR Assignments of Natural Complex Molecules: Application to 3β,7‐Dihydroxy‐5,6‐epoxycholestanes
Authors: Poza Jesús Javier , Jiménez Carlos , Rodríguez Jaime
Published: July 2008

In order to reproduce the stereochemical dispositions of the epoxy and hydroxy functionalities, four 3β,7‐hydroxy‐5,6‐epoxycholestanes were easily prepared from cholesterol, and their NMR spectroscopic data were experimentally obtained from 1D and 2D NMR experiments. An exhaustive QM‐J‐based analysis was then performed to replicate the experimental H–H and C–H coupling constants as well as the 13C NMR chemical shifts. The B3LYP GIAO methodology with the 6‐311‐G(d,p) basis set was chosen and showed that the data obtained from rings A and B were sufficient to calculate the correct stereochemistry of the 5,6‐epoxy and 7‐hydroxy groups. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
Synthesis of α,α‐Difluoro‐β‐amino Esters or gem‐Difluoro‐β‐lactams as Potential Metallocarboxypeptidase Inhibitors
Authors: Boyer Nicolas , Gloanec Philippe , De Nanteuil Guillaume , Jubault Philippe , Quirion Jean‐Charles
Published: July 2008

The synthesis of gem‐difluorinated β‐lactams and gem‐difluorinated β‐amino acids, each possessing a potential basic functional group, from ethyl bromodifluoroacetate and either imines (for β‐lactams) or N‐(α‐aminoalkyl)benzotriazoles (for β‐amino esters) was investigated. A series of these compounds were used for the design of novel metallocarboxypeptidase inhibitors. N‐Alkylation and N‐acylation of these two versatile scaffolds were carried out, leading to the expected targets in moderate to good yields.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
Tuning the Chemoselectivity of the Metathesis Reactions of N‐Substituted 2‐Azabicyclo[2.2.1]hept‐5‐en‐3‐one
Authors: Aljarilla Ana , Plumet Joaquín
Published: July 2008

By using the second‐generation Hoveyda–Grubbs precatalyst, the metathesis transformations of N‐substituted 2‐azabicyclo[2.2.1]hept‐5‐en‐3‐one derivatives have been explored. In the absence of any external alkene (cross‐metathesis partner), substituted pyrrolizidin‐3‐one derivatives were obtained by ring‐opening metathesis/ring‐closing metathesis tandem reactions. In the presence of an external alkene, N‐substituted 2‐pyrrolidinones were isolated by ring‐opening metathesis/cross metathesis tandem reactions. In this case, and by using an alkene other than ethylene (allyltrimethylsilane), the reaction was totally chemo‐ and diastereoselective. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
Electrochemistry of Mitochondria: A New Way to Understand Their Structure and Function
Authors: Zhao Jing , Meng Fanben , Zhu Xiaoli , Han Kun , Liu Shanli , Li Genxi
Published: July 2008

In this article, electrochemistry of mitochondria is achieved. Cyclic voltammograms of freshly prepared mitochondria were obtained by immobilizing mitochondria together with glutaraldehyde and bovine serum albumin on the surface of a pyrolytic graphite electrode. Two pairs of redox peaks could be observed which were ascribed to the electron transfer reactions of cytochrome c and FAD/FADH2. Study of submitochondrial particles was also conducted, which could confirm the results of the study of the entire mitochondria. The redox wave of NADH could be obtained due to the destruction of the membrane of mitochondria. We have also checked the function of succinate in mitochondria by employing the electrochemical method. This work is not only the first to be able to obtain the direct electrochemistry of mitochondria, but is also beneficial to the further understanding of the structure and function of mitochondria in vitro.
Underivatized cyclic olefin copolymer as substrate material and stationary phase for capillary and microchip electrochromatography
Authors: Gustafsson Omar , Mogensen Klaus B. , Kutter Jörg P.
Published: July 2008

We report, for the first time, the use of underivatized cyclic olefin copolymer (COC, more specifically: Topas) as the substrate material and the stationary phase for capillary and microchip electrochromatography (CEC), and demonstrate chromatographic separations without the need of coating procedures. Electroosmotic mobility measurements in a 25 μm id Topas capillary showed a significant cathodic EOF that is pH‐dependent. The magnitude of the electroosmotic mobility is comparable to that found in glass substrates and other polymeric materials. Open‐tubular CEC was employed to baseline‐separate three neutral compounds in an underivatized Topas capillary with plate heights ranging from 5.3 to 12.7 μm. The analytes were detected using UV absorbance at 254 nm, thus taking advantage of the optical transparency of Topas at short wavelengths. The fabrication of a Topas‐based electrochromatography microchip by nanoimprint lithography is also presented. The microchip has an array of pillars in the separation column to increase the surface area. The smallest features that were successfully imprinted were around 2 μm wide and 5 μm high. No plasma treatment was used during the bonding, thus keeping the surface properties of the native material. An RP microchip electrochromatography separation of three fluorescently labeled amines is demonstrated on the underivatized microchip with plate heights ranging from 3.4 to 22 μm.
Optimization of Two‐Step Cotton Scouring with β‐Cyclodextrin and Alkaline Pectinase
Authors: Wang Q. , Fan X. , Yuan J. , Wang P. , Cui L. , Chen J.
Published: July 2008

The hydrophobic cuticle of cotton fibers has formed a natural barrier for individual pectinases to catalyze its substrates (pectins beneath the cuticle), thus resulting in an insufficient bio‐scouring. β‐Cyclodextrin with a special non‐polar cavity is accommodating some organic compounds (dyestuffs, functional finishes, etc.) to form stable inclusion complexes. It has been demonstrated that β‐cyclodextrin can be used as a scouring agent of cotton fabric because this special inclusion helps to remove hydrophobic waxes in the cuticle of cotton. Considering possible synergetic effects between pectinase and β‐cyclodextrin which might lead to better cotton scouring effects, two reverse cases of scouring processing, β‐CD treatment followed by pectinase treatment and pectinase treatment followed by β‐cyclodextrin treatment, were put forward. For each scouring processing, optimal scouring parameter dosages of pectinase and β‐cyclodextrin as well as incubation time were determined by means of wettability. β‐CD treatment followed by pectinase treatment produced a better scouring effect than β‐CD treatment following pectinase treatment because the partially elimination of hydrophobic waxes and fats in the cotton cuticle could increase the accessibility of the subsequent pectinase to the substrates. Finally, the whiteness and strength of the bleached cotton fabrics and the K/S values (color depth) of the dyed cotton fabrics were measured and compared with those of conventionally alkali‐treated ones.
Combined Bio‐carbonization and Dyeing of Wool: A Possibility Using Cell Wall‐Degrading Enzymes and 1:1 Metal–Complex Dyes
Authors: Gouveia I. C. , Fiadeiro J. M. , Queiroz J. A.
Published: July 2008

This study was undertaken to investigate the possibility of a new process to remove plant residues from wool, using enzymes as biocatalysts together with a dyeing process in a two‐step exhaustion process, performed in a single bath. The enzymes were selected in order to hydrolyze the polysaccharides in primary plant cell walls and middle lamella, resulting in more fragile residues easier to be removed. Commercial enzymatic preparations of Trichoderma reesei and Aspergillus aculeatus were used, after appropriate optimization. A total enzyme loading of 1.0 mL/L of each enzymatic preparation yielded an equivalent amount of 241.2 mg of glucose per gram of plant residue, under the optimal conditions: 40.5 °C, pH 4.0, and 0.75 mL/L of a non‐ionic wetting agent. Reducing groups of the total released sugars were determined with the Miller reactive 3,5‐dinitrosalicilic acid (DNS), which has been used for the indirect measurement of the efficiency of the process. Furthermore, to enhance the degradation of the plant residues, dyeing processes using the incubation bath and several acid and metal–complex dyes, usually applied on wool dyeing, were tested. The dyeing procedure with 1:1 metal–complex dyes adjusted to pH 1.9 with sulfuric acid has promoted a higher degradation of the plant residues without damaging wool fibers. Accordingly, higher concentration of glucose was detected by the DNS reagent and higher weight losses of the plant residues were obtained when compared to enzymatic treatment without dyeing. The low pH used in the dyeing procedure increases the degradation of the cell wall polysaccharides, by acid catalysis. Also, scanning electron microscopy was used to show the plant cell wall degradation.
Strategies towards the Functionalization of Subtilisin E from Bacillus subtilis for Wool Finishing Applications
Authors: Araújo R. , Cavaco‐Paulo A. , Casal M.
Published: July 2008

Subtilisin E is an alkaline serine protease secreted by the Gram positive bacterium Bacillus subtilis and widely used in industry as a biocatalyst for various processes. The most common application of subtilisins is in laundry detergents. However, due to environmental concerns, the application of subtilisins to treat wool, is under study. There are some reports regarding the attempts to substitute the conventional chlorine treatment by an enzymatic process capable of providing the same characteristics to the fabric, like anti‐shrinking and better uptake and fixation of the dyestuff. However, the degree of uncontrolled hydrolysis due to diffusion of the enzyme inside the wool fiber causes unacceptable losses of strength. To overcome this fact, and taking advantage of the x‐ray crystallographic structure, the authors have modified subtilisin E genetically, increasing its molecular weight, to restrict the hydrolysis to the surface of the wool fibers. Therefore, three genetically modified enzymes with a molecular weight 2‐fold to 4‐fold higher than the native subtilisin E were produced and assessed for activity. The prokaryotic expression systems, pET25b (+), pET11b and pBAD C, were explored for the production of recombinant enzymes. The results demonstrated that regardless the expression system or strain used, chimeric subtilisins were not expressed with the correct folding. No active and soluble recombinant protein was recovered under the testing conditions. Despite this drawback, a novel approach was described to increase the molecular weight of subtilisin. The reported results are noteworthy and can indicate good guidelines for future work aiming at the solubilization of recombinant chimeric subtilisins.
Comparative Analysis of the Physiological and Structural Properties of a Medium Chain Length Polyhydroxyalkanoate Depolymerase from Pseudomonas putida KT2442
Authors: de Eugenio L. I. , García J. L. , García P. , Prieto M. A. , Sanz J. M.
Published: July 2008

Medium‐chain‐length polyhydroxyalkanoates (mcl‐PHAs) produced by Pseudomonas putida KT2442 can be chiral 3‐hydroxyalkanoic acids catabolized by the intracellular PhaZ depolymerase when the bacteria are cultured under carbon limitation. PhaZ is an intracellular depolymerase and is attached to PHA granules. In this study, the PhaZ expression was analyzed by Western blot and Real Time RT‐PCR assays. The PhaZ expression depends on the carbon source and nitrogen limitation conditions. The substrate recognition of the binding surface was altered using directed mutagenesis experiments. A structural comparison between intracellular and extracellular PHA depolymerases was carried out using PhaZ from P. putida KT2442 and P. fluorescens GK13, respectively. Both share the presence of a core displaying an α/β‐hydrolase fold, but the former would possess an additional “lid” domain that suggests some kind of interfacial activation and that may account for differences in substrate specificity for both proteins.