bluuebunny/crossref_metadata_2025 huggingface dataset:
A novel model of intracranial meningioma in mice using luciferase-expressing meningioma cells
Authors: Ragel Brian T. , Elam Isaac L. , Gillespie David L. , Flynn Jeannette R. , Kelly David A. , Mabey David , Feng Harvey , Couldwell William T. , Jensen Randy L.
Published: February 2008

Object

Meningioma research has been hindered by the inability to sequentially measure intracranial tumor growth in a cost-effective, efficient manner. Recently, the luciferase gene has been transfected into cancer lines to obtain cells that express the luciferase enzyme, which oxidizes luciferin in a reaction that releases photon energy that can be measured noninvasively by bioluminescence imaging (BLI) systems. The authors describe a mouse model of intracranial meningioma that uses this novel BLI system.

Methods

The immortal meningioma cell lines CH-157-MN and IOMM-Lee were transfected with luciferase and neomycin phosphotransferase (LucNeo) and selected with G418. These cells were stereotactically implanted at skull base and cerebral convexity locations in nude mice. Animals were imaged for bioluminescence biweekly, and 5 mice underwent magnetic resonance (MR) imaging. Tumors were harvested for immunohistochemical and ultrastructural analysis.

Results

The CH-157-MN-LucNeo and IOMM-Lee-LucNeo cell lines were successfully implanted intracranially in mice. The tumor induction rate for CH-157-MN-LucNeo skull base tumors was 90% (36 of 40 procedures). Statistical analysis of CH-157-MN-LucNeo skull base tumor volume measured on MR imaging correlated with the results of BLI showed an R value of 0.900. The tumors exhibited characteristics of aggressive meningiomas by insinuating along arachnoid planes and invading brain.

Conclusions

Noninvasive BLI was successfully used to image intracranial meningiomas in mice. The tumors grew in a fashion similar to that of aggressive meningiomas in humans, and exhibited the microscopic, immunohistochemical, and ultrastructural features characteristic of meningiomas. This animal model overcomes the main obstacle in studying intracranial meningiomas by enabling sequential noninvasive tumor measurement in a cost-effective manner.
Glomus tumor and glomangioma of the nerve
Authors: Scheithauer Bernd W. , Rodriguez Fausto J. , Spinner Robert J. , Dyck P. James , Salem Ayman , Edelman Fredric L. , Amrami Kimberly K. , Fu Yao-Shi
Published: February 2008

✓ As a rule, normal human nerve does not contain glomus bodies. Nonetheless, rare examples of glomus tumors do arise in peripheral nerves of various sizes. Their pathobiological characteristics are poorly understood, but reported examples have been small and clinically benign. The authors identified in 1 patient each a glomus tumor and a glomangioma involving nerve. Clinical histories as well as imaging and surgical findings were reviewed. All available H & E–stained slides were examined in both cases. Immunohistochemical stains and electron microscopy, as appropriate, were also performed. The lesions were subtotally and completely resected, respectively. An uneventful postoperative recovery was noted in both patients. Glomus tumors and glomangiomas can involve major nerves on rare occasions. They seem to follow a favorable clinical course, and conservative resection can be of benefit.
Cholesterol granuloma of the lateral ventricle
Authors: Grossi Peter M. , Ellis Michael J. , Cummings Thomas J. , Gray Linda L. , Fukushima Takanori , Sampson John H.
Published: February 2008

✓Cholesterol granulomas (CGs) are benign lesions resulting from an inflammatory reaction to cholesterol and hemosiderin. These masses most often arise within the temporal bone or nasal sinuses; intracerebral CGs are extremely rare. In this report the authors present an unusual case of a CG arising within the lateral ventricle.

The patient presented with transient hemiparesis and numbness. Computed tomography and magnetic resonance imaging demonstrated a cystic partially enhancing midline mass within the right lateral ventricle, expanding the ventricle and displacing the septum pellucidum. The patient underwent an interhemispheric, transcallosal resection of the lesion. Microscopic examination revealed a granulomatous inflammatory lesion containing cholesterol clefts, macrophages, and hemosiderin. Embedded within the granulomatous response were foci of tiny cystlike structures lined by nonciliated flattened cuboidal epithelium, consistent with the diagnosis of CG.

To the authors' knowledge this is the first reported case of CG presenting as an intraventricular mass. The origin of this lesion is unclear, but it may relate to prior traumatic brain injury. The authors describe the presentation, imaging findings, histopathological characteristics, and surgical treatment of this rare lesion and related pathological entities.
A heterotopic ossification related to temporary placement of a skull bone flap
Authors: Safaz İsmail , Alaca Rıdvan , Bilgiç Serkan , Yazıcıoğlu Kamil
Published: February 2008

✓The authors report on a 19-year-old man who sustained a traumatic brain injury. Following decompressive craniotomy, he suffered from an unusual heterotopic ossification due to the temporary placement of the skull bone flap in his thigh. To the best of the authors' knowledge, this is the first time that a possible causal relationship between these entities has been reported in the literature.
Endoscopic endonasal suturing of dural reconstruction grafts: a novel application of the U-Clip technology
Authors: Gardner Paul , Kassam Amin , Snyderman Carl , Mintz Arlan , Carrau Ricardo , Moossy John J.
Published: February 2008

✓ Cerebrospinal fluid (CSF) leakage following endoscopic endonasal skull base resection can be a significant problem. A method for securing tissue grafts is needed. In this paper the authors used an endonasal suturing device to secure the graft reconstruction following endonasal tumor resection.

The U-Clip anastomotic device (Medtronic), developed for cardiovascular anastomoses, was used to secure the tissue graft to native dura. A specialized needle driver and hemoclip applier were used for the application and deployment of this device. No suture tying was necessary, facilitating its endonasal application.

The graft was successfully secured in its desired position to native dura by using the U-Clip anastomotic device. The patient did not suffer a postoperative CSF leak, and postoperative imaging and endoscopy revealed that the graft was in a good position. There was no complication from the use of the device.

The U-Clip anastomotic device can be used as a suture device during endonasal surgery. It may prevent tissue graft migration and help prevent CSF leakage.
Chimpanzees as fauna: comparisons of sympatric large mammals across long‐term study sites
Authors: Russak Samantha M. , McGrew W.C.
Published: February 2008

Although much research has shown otherwise, chimpanzees are still often classed as rainforest‐dwellers. Most long‐term studies of wild chimpanzees (Pan troglodytes) are not situated in evergreen, closed‐canopy equatorial forests, but instead are conducted in more open habitats. This study aims to elucidate the extent of chimpanzee ecological diversity by scrutinizing (recently) sympatric mammalian fauna at established study sites. We compiled presence or absence data on large mammal species at eight sites: Assirik, Bossou, Budongo, Gombe, Kibale, Lopé, Mahale, and Tai. The sites were rank ordered on the most basic ecological variable: annual total rainfall. Only three of the 65 mammalian genera compiled were sympatric with chimpanzees at all sites: Potamochoerus (bushpig), Syncerus (buffalo), and Panthera pardus (leopard). Some subfamilies (e.g. colobines) were present at most sites, but some families (e.g. hyenids) were absent at most sites. Some taxa (e.g. suids, cercopithecines) correlated better than others (e.g. canids) with basic ecological variables. The most extreme chimpanzee study site for which data are available is Assirik, Senegal. Nowhere else are chimpanzees sympatric with Erythrocebus, Alcelaphus, Hippotragus, and Ourebia. As chimpanzees are often behavioral models for extinct hominins, these living faunal assemblages have implications for paleo‐ecological reconstructions of ancestral habitats. Am. J. Primatol. 70:402–409, 2008. © 2008 Wiley‐Liss, Inc.
Studies on cyanosilylation reaction catalyzed by LnN complexes
Authors: Mei Luo , Long Shang Wei , Liang Hu Ke , Xuan Wu Shu
Published: February 2008

A novel family of LnN complexes was synthesized by two methods and as the Lewis acidic catalysts in application to the cyanosilylation of prochiral ketones and aldehydes, which gave yields > 99% of some cyano trimethylsilyl ethers from the wide range of aldehyde substrates and moderate yields from the ketone substrates at room temperature using 20 mol% catalyst loadings. Copyright © 2008 John Wiley & Sons, Ltd.
Adsorption of silane onto cellulose fibers. II. The effect of pH on silane hydrolysis, condensation, and adsorption behavior
Authors: Bel‐Hassen Ramzi , Boufi Sami , Salon Marie‐Christine Brochier , Abdelmouleh Makki , Belgacem Mohamed Naceur
Published: February 2008

The hydrolysis of four alkoxysilane agents, γ‐methacryloxypropyl trimethoxysilane (MPS), γ‐mercaptopropyl trimetoxysilane (MRPS), octyl trimethoxysilane OS), and N‐phenyl‐γ‐aminopropyl trimethoxysilane (PAPS), was carried out in an ethanol/water (80/20) solution under both acid and basic conditions. 1H, 13C, and 29Si NMR spectroscopy were used to provide quantitative analyses of the structural components during hydrolysis and condensation reaction. The analysis revealed that the acid‐catalyzed hydrolysis of silane allows the formation of high amount of silanol groups, reduced the selfcondensation reaction among silanol groups and stabilized the proportion of intermediary hydrolyzed species for several days. However, under basic condition, condensation reactions proceed as soon as the hydrolysis reaction started leading to the rapid consumption of silanol groups through selfcondensation and to the growth of three‐dimensional high molecular structures. The interaction of MPS and MRPS with cellulose fibers and the evolution of their surface properties were then investigated using adsorption isotherms and contact angle measurement. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Impact of nano‐topography on bacterial attachment
Authors: Mitik‐Dineva Natasa , Wang James , Mocanasu Radu C. , Stoddart Paul R. , Crawford Russell J. , Ivanova Elena P.
Published: February 2008

The adhesion of bacteria to surfaces is an important biological process, but one that has resisted simple categorization due to the number and complexity of parameters involved. The roughness of the substrate is known to play a significant role in the attachment process, particularly when the surface irregularities are comparable to the size of the bacteria and can provide shelter from unfavorable environmental factors. According to this scenario, roughness on a scale much smaller than the bacteria would not be expected to influence the initial attachment. To test this hypothesis, the impact of nanometer‐scale roughness on bacterial attachment has been investigated using as‐received and chemically etched glass surfaces. The surface modification by etching resulted in a 70% reduction in the nanoscale roughness of the glass surface with no significant alteration of its chemical composition or charge. Nevertheless, the number of bacteria adhering to the etched surface was observed to increase by a factor of three. The increase in attachment was also associated with an alteration in cellular metabolic activity as demonstrated by changes in characteristic cell morphologies and increased production of extracellular polymeric substances. The results indicate that bacteria may be more sensitive to nanoscale surface roughness than was previously believed.
Dynamical analysis of the calcium signaling pathway in cardiac myocytes based on logarithmic sensitivity analysis
Authors: Kim Tae‐Hwan , Shin Sung‐Young , Choo Sang‐Mok , Cho Kwang‐Hyun
Published: February 2008

Many cellular functions are regulated by the Ca2+ signal which contains specific information in the form of frequency, amplitude, and duration of the oscillatory dynamics. Any alterations or dysfunctions of components in the calcium signaling pathway of cardiac myocytes may lead to a diverse range of cardiac diseases including hypertrophy and heart failure. In this study, we have investigated the hidden dynamics of the intracellular Ca2+ signaling and the functional roles of its regulatory mechanism through in silico simulations and parameter sensitivity analysis based on an experimentally verified mathematical model. It was revealed that the Ca2+ dynamics of cardiac myocytes are determined by the balance among various system parameters. Moreover, it was found through the parameter sensitivity analysis that the self‐oscillatory Ca2+ dynamics are most sensitive to the Ca2+ leakage rate of the sarcolemmal membrane and the maximum rate of NCX, suggesting that these two components have dominant effects on circulating the cytosolic Ca2+.
High‐Energy X‐ray Absorption Spectroscopy: A New Tool for Structural Investigations of Lanthanoids and Third‐Row Transition Elements
Authors: D'Angelo Paola , De Panfilis Simone , Filipponi Adriano , Persson Ingmar
Published: February 2008

This is the first systematic study exploring the potential of high‐energy EXAFS as a structural tool for lanthanoids and third‐row transition elements. The K‐edge X‐ray absorption spectra of the hydrated lanthanoid(III) ions both in aqueous solution and in solid trifluoromethanesulfonate salts have been studied. The K‐edges of lanthanoids cover the energy range from 38 (La) to 65 keV (Lu), while the corresponding energy range for the L3‐edges is 5.5 (La) to 9.2 keV (Lu). We show that the large widths of the core‐hole states do not appreciably reduce the potential structural information in the high‐energy K‐edge EXAFS data. Moreover, for lanthanoid compounds, more accurate structural parameters are obtained from analysis of K‐edge than from L3‐edge EXAFS data. The main reasons are the much wider k range available and the absence of double‐electron transitions, especially for the lighter lanthanoids. A comparative K‐ and L3‐edge EXAFS data analysis of nonahydrated crystalline neodymium(III) trifluoromethanesulfonate demonstrates the clear advantages of K‐edge analysis over conventionally performed studies at the L3‐absorption edge for structural investigations of lanthanoid and third‐row transition metal compounds. The coordination chemistry of the hydrated lanthanoid(III) ions in aqueous solution and solid trifluoromethanesulfonate salts, based on the results of both the K‐ and L3‐edge EXAFS data, is thoroughly discussed in the next paper in this series (I. Persson, P. D'Angelo, S. De Panfilis, M. Sandström, L. Eriksson, Chem. Eur. J. 2008, 14, DOI: 10.1002/chem.200701281).
Topological Classification and Supramolecular Chirality of 21‐Helical Ladder‐Type Hydrogen‐Bond Networks Composed of Primary Ammonium Carboxylates: Bundle Control in 21‐Helical Assemblies
Authors: Yuge Tetsuharu , Sakai Tatsuya , Kai Nobuyasu , Hisaki Ichiro , Miyata Mikiji , Tohnai Norimitsu
Published: February 2008

The supramolecular chirality of 1D ladder‐type hydrogen‐bond networks composed of primary ammonium carboxylates was determined based on topological considerations. Chirality in such networks is based on the absolute configuration of the primary ammonium cation, which arises from discrimination between the two oxygen atoms of the carboxylate anion. The configurations of the cations and anions generate topological diversity in the networks, which are classified into six subgroups. In the Cambridge Structural Database, salts based on ladder type 1 constitute over 70 % of salts with a 1D‐ladder‐type network. Ladder type 1, based on a 21‐axis, is not superimposable on its mirror image, which leads to the first definition of right‐ or left‐handedness of 21‐helicity on the basis of supramolecular tilt chirality. Helical assemblies of 21‐type with triaxial chirality can be assembled in various ways to yield chiral bundles and crystals. On the basis of these considerations, we constructed clay mimic structures with several bundle patterns by connecting the hydrogen‐bond networks by using bifunctional molecules. These results open up the possibility of in‐depth crystal engineering based on hydrogen‐bond topology.
On the origin of circular dichroism in trigonal dihedral d6 complexes of bidentate ligands containing only σ‐orbitals. A qualitative model based on a density functional theory study of Λ‐[Co(en)3]3+
Authors: Fan Jing , Ziegler Tom
Published: February 2008

Time‐dependent density functional theory (TD‐DFT) in conjunction with qualitative molecular orbital theory is employed to interpret the circular dichroism (CD) spectrum of Λ‐[Co(en)3]3+. The simulated spectrum based on TD‐DFT is compared in details with the experimental data. Emphasis is put on a qualitative understanding of the origin of optical activity in σ‐bonded trigonal dihedral complexes with bidentate ligands in general. Rotatory strengths associated with the CD bands of both d‐d transitions and ligand‐to‐metal charge transfer (LMCT) are interpreted based on the metal–ligand σ‐interactions. These interactions are in turn analyzed in terms of symmetry unique overlaps between metal d‐ and symmetry ligand‐orbitals as well as the dependence of these overlaps on geometrical parameters of the complex. Chirality, 2008. © 2008 Wiley‐Liss, Inc.
Circular dichroism of polynucleotides: Interactions of NiCl2 with poly(dA‐dT)·poly(dA‐dT) and poly(dG‐dC)·poly(dG‐dC) in a water‐in‐oil microemulsion
Authors: Airoldi Marta , Gennaro Giuseppe , Giomini Marcello , Giuliani Anna Maria , Giustini Mauro
Published: February 2008

The thermal behavior of the synthetic, high molecular weight, double stranded polynucleotides poly(dA‐dT)·poly(dA‐dT) [polyAT] and poly(dG‐dC)·poly(dG‐dC) [polyGC] solubilized in the aqueous core of the quaternary water‐in‐oil cationic microemulsion CTAB|n‐pentanol|n‐hexane|water in the presence of increasing amounts of NiCl2 at several constant ionic strength values (NaCl) has been studied by means of circular dichroism and electronic absorption spectroscopies. In the microemulsive medium, both polynucleotides show temperature‐induced modifications that markedly vary with both Ni(II) concentration and ionic strength. An increase of temperature causes denaturation of the polyAT duplex at low nickel concentrations, while more complex CD spectral modifications are observed at higher nickel concentrations and ionic strengths. By contrast, thermal denaturation is never observed for polyGC. At low Ni(II) concentrations, the increase of temperature induces conformational transitions from B‐DNA to Z‐DNA form, or, more precisely, to left‐handed helical structures. In some cases, at higher nickel concentrations, the CD spectra suggest the presence of Z′‐type forms of the polynucleotide. Chirality, 2008. © 2008 Wiley‐Liss, Inc.
Neck treatment of patients with early stage oral tongue cancer
Authors: Huang Shiang‐Fu , Kang Chung‐Jan , Lin Chen‐Yu , Fan Kang‐Hsing , Yen Tzu‐Chen , Wang Hung‐Ming , Chen I‐How , Liao Chun‐Ta , Cheng Ann‐Joy , Chang Joseph Tung‐Chieh
Published: February 2008

BACKGROUND.

The role of elective and therapeutic selective neck dissection in patients with early stage cancer of the oral tongue remains controversial. The purpose was to investigate the role of neck treatment in the management of this condition.

METHODS.

A total of 380 patients with cT1‐2N0 oral tongue cancer were retrospectively reviewed. Patients were staged by means of computed tomography (CT) or magnetic resonance imaging (MRI) scans. A total of 324 patients received elective neck dissection (END), whereas 56 participants received observation (OBS). In all, 287 patients received supraomohyoid neck dissection (SOND), whereas 37 patients received modified radical neck dissection (MRND). Overall survival (OS) and neck control rates (NCR) were investigated according to the treatment modality.

RESULTS.

In the END group the occult metastasis (OM) rates in cervical lymph nodes were 5.2% for cT1 lesions and 14.6% for cT2 lesion (P = .005). The 5‐year OS (P = .029) and NCR rates (P = .001) were significantly better in the END group compared with the OBS group. Patients who received MRND had a better 5‐year NCR compared with SOND, albeit not significantly (91.4% vs 85.3%, P = .415). Multivariate analysis showed that END and stage were independent predictors of both NCR and OS.

CONCLUSIONS.

END should be performed routinely in patients with early‐stage oral tongue cancer, even in the presence of negative neck by CT scans and MRI. Cancer 2008. © 2008 American Cancer Society
Neuronal expression and subcellular localization of cholesterol 24‐hydroxylase in the mouse brain
Authors: Ramirez Denise M.O. , Andersson Stefan , Russell David W.
Published: February 2008

Cholesterol 24‐hydroxylase is a cytochrome P450 (CYP46A1) that is selectively expressed in the brain and is responsible for the majority of cholesterol turnover in the central nervous system. Mice deficient in 24‐hydroxylase exhibit impaired learning and defective hippocampal long‐term potentiation, suggesting that the metabolism of cholesterol by this enzyme is required for learning and memory formation. To determine where in the neuron cholesterol turnover was taking place, monoclonal antibodies directed against 24‐hydroxylase were generated by immunization of mice with recombinant protein and used to detect the enzyme in brain homogenates, cultured neurons, and histological sections. 24‐Hydroxylase was localized to the endoplasmic reticulum and was distributed throughout the cell bodies and dendrites of multiple types of neurons; the enzyme was not detected in axon terminals or in the cells of 24‐hydroxylase knockout mice. 24‐Hydroxylase was highly expressed in pyramidal neurons of the hippocampus and cortex, in Purkinje cells of the cerebellum, and in hippocampal and cerebellar interneurons. Within the retina, 24‐hydroxylase was detected in ganglion cells and some but not all cells of the inner nuclear layer. These findings reveal the microsomal localization of 24‐hydroxylase and provide subcellular insight into cholesterol turnover in the brain. J. Comp. Neurol. 507:1676–1693, 2008. © 2008 Wiley‐Liss, Inc.
Developmental origins of species differences in telencephalon and tectum size: Morphometric comparisons between a parakeet (Melopsittacus undulatus) and a quail (Colinus virgianus)
Authors: Striedter Georg F. , Charvet Christine J.
Published: February 2008

Parrots, including parakeets, evolved significantly larger brains than other birds, relative to their body size, and they possess a proportionately larger telencephalon. For example, the telencephalon occupies approximately 68% of the brain in parakeets but only 52% in bobwhite quail. The present study was designed to determine when and how this difference in brain region proportions arises during development. To that end, we present volumetric data on the major brain regions in parakeets and bobwhite quail at several stages of embryogenesis, at hatching and, for the parakeets, 1 week after hatching. We also report on the proportional sizes of each region's proliferative and postproliferative zones. One major finding is that parakeets develop a proportionately larger telencephalon relatively late in development and that this late increase correlates with a delay in telencephalic neurogenesis. The most prominent aspect of this delayed telencephalic development is a tremendous expansion of the proliferative subventricular zone in the telencephalon of late embryonic and posthatching parakeets. The second major finding is that the tectum is much smaller in parakeets than in quail at all developmental stages examined, suggesting that the tectum's reduced size is due to an evolutionary change in how much tissue was allocated to become tectum at the time of brain regionalization. Collectively these findings indicate that evolutionary changes in brain region proportions are caused not by a single type of change but by several distinct developmental mechanisms, including changes in brain regionalization and neurogenesis timing. J. Comp. Neurol. 507:1663–1675, 2008. © 2008 Wiley‐Liss, Inc.
Crystallization of vitamin C in a continuous DT MSMPR crystallizer – Size independent growth kinetic model approach
Authors: Wierzbowska B. , Piotrowski K. , Koralewska J. , Matynia A. , Hutnik N. , Wawrzyniecki K.
Published: February 2008

The experimental results concerning continuous mass crystallization process in L(+)‐ascorbic acid – water system are presented and discussed. Influence of L(+)‐ascorbic acid concentration in a feeding solution and mean residence time of suspension in laboratory DT MSMPR crystallizer on product crystal size distribution as well as nucleation and growth kinetics were determined. Kinetic parameter values were evaluated on the basis of size–independent growth (SIG) kinetic model (McCabe's ΔL law). It was observed, that within the examined range of crystallizer productivity (120–1600 kg LAA crystals m–3h–1) crystal product population of mean size Lm from 0.2 to 0.3 mm and CV from 66.6 to 49% is withdrawn. Linear growth rate values present decreasing trend (from ca. 7 · 10–8 to ca. 6 · 10–8 m s–1) with the productivity increase (assuming constant mean residence time of suspension τ = 900 s). Occurrence of secondary nucleation within the circulated and mixed suspension, resulting from crystal attrition and breakage, was observed. The parameter values in design equation connecting linear growth rate and suspension density with nucleation rate were determined. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Creation of calcite hollow microspheres with attached bundles of aragonite needles
Authors: Tang Hua , Yu Jiaguo , Zhao Xiufeng , Ng Dickon H. L.
Published: February 2008

Novel calcite hollow microspheres attached with bundles of aragonite needles have been synthesized via a simple precipitation reaction of aqueous solutions of CaClB2B and NaB2BCOB3B in the presence of MgP2+P ions at room temperature. The experimental results revealed that an appropriate molar ratio of [MgP2+P]/[CaP2+P], pH value of the solution and aging time are crucial for the formation of the unusual hierarchical CaCOB3B superstructure. A possible growth mechanism is proposed. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Synthesis and crystallographic characterization of a seven‐coordinate Mn(II) complex
Authors: Chen Huating , Deng Dongsheng , Miao Shaobin , Ji Baoming
Published: February 2008

A seven‐coordinate Mn(II) complex of N,N,N ′,N ′‐tetrakis[(2‐benzimidazolyl)methyl]‐1,2‐cyclohexanediamine (CDTB), namely, [Mn(CDTB)(DMF)](Pic)2·C2H5OH was synthesized and characterized by elemental analyses, IR spectra and X‐ray single‐crystal diffraction. The complex crystallizes in a typical hybrid organic‐inorganic pattern. The crystal belongs to the monoclinic system, space group P 2 (1) / n with cell constants a = 13.3343(6) Å, b = 33.7015(16) Å, c = 13.7286(6) Å, β = 108.9990(10)°, Z = 4. The structure was solved by direct methods and refined to R = 0.0561 (wR2 = 0.1172). The structure analysis reveals that the Mn(II) has a capped octahedron geometry with seven‐coordination mode, furthermore, the [Mn(CDTB)(DMF)]2+ building blocks were extended into well‐ordered supramolecular networks by complementary hydrogen bonds, and the linkers of the ethanol molecules and the picrate anions play an important role in the self‐assembly process. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Growth, spectral and thermal properties of KAP single crystals in the presence of DL‐Alanine and L‐Methionine amino acid dopants
Authors: Uthayarani K. , Sankar R. , Shashidharan Nair C. K.
Published: February 2008

Single crystals of potassium acid phthalate (KAP) and amino acid (DL‐Alanine, L‐Methionine) doped KAP were grown from aqueous solutions by slow cooling method. The grown crystals were characterized using powder X Ray diffraction (XRD) and Fourier Transform Infrared (FTIR) analysis. The thermal stability of KAP in the presence of dopants was analysed using Thermogravimetric and Differential Scanning caloriemetric (TGA/ DSC) studies and the maximum temperature for non linear optical application of this compound in the presence of dopants was found out. The transmittance of KAP was found to increase in the presence of dopants. Etch pits were observed for all the crystals using different etchants. Vickers microhardness tests were performed to study the mechanical stability of the crystals. The hardness of DL‐alanine doped KAP is more than that of L‐alanine doped KAP crystal. The dielectric constant and loss were determined as a function of temperature. Frequency response of the dielectric constant and dielectric loss factor have been studied over the frequency range of 50Hz – 5MHz. Second harmonic generation (SHG) was confirmed in all the crystals using the Kurtz and Perry powder technique. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Neue Regelungen für Kupplungen zur Verwendung an Stahl‐ und Aluminiumrohren
Authors: Schult Andreas
Published: February 2008

Kupplungen sind Gerüstbauteile, die wiederholt in temporären Konstruktionen verwendet werden. Die Erfahrungen haben gezeigt, dass diese Gerüstbauteile bei entsprechender Behandlung und Wartung durchaus eine Lebensdauer von 30 Jahren oder auch mehr aufweisen können. Voraussetzung hierbei ist, dass zum Zeitpunkt der Verwendung eine gültige technische Regel für die Verwendung vorliegt. Diese Forderung hat zur Folge, dass jede Änderung der technischen Regel im Laufe der Zeit zu der Frage führt, wie mit vorhandenen Beständen an Gerüstbauteilen zu verfahren ist.
Inverkehrbringen und Verwendung von Bauprodukten – die Bauproduktenrichtlinie und ihre Umsetzung
Authors: Springborn Matthias
Published: February 2008

Ende 1988 ist die Bauproduktenrichtlinie erlassen worden. Damit nahm man sich auf europäischer Ebene eines Binnenmarktsektors an, der eine herausragende Bedeutung für Europa hat. Mit 11,8 Millionen direkt Beschäftigter ist das Baugewerbe der größte Arbeitgeber im europäischen produzierenden Gewerbe, auf den in der Europäischen Union der 15 “alten” Mitgliedstaaten 7 % der Gesamtbeschäftigung und 28 % der Beschäftigung im produzierenden Gewerbe entfallen. Man schätzt, dass in der EU der 15 etwa 26 Millionen Arbeitskräfte in irgendeiner Weise vom Baugewerbe abhängig sind. Die Bauinvestitionen beliefen sich 2003 auf rund 910 Milliarden 3, das waren 10 % des Bruttoinlandsproduktes und 51,2 % der Bruttoanlageinvestitionen von EU‐15.

Es handelt sich aber ebenso um einen Sektor, der besondere Schwierigkeiten bei der europäischen Harmonisierung mit sich bringt und Probleme aufwirft, für deren Lösung es bisher keine Präzedenzfälle gibt. Warum das so ist, das soll im folgenden Beitrag deutlich werden.
Leitlinie für europäische technische Zulassungen “Abdichtungen für Böden und Wände in Nassräumen” (ETAG 022) Teil 1 im Bundesanzeiger bekannt gemacht
Authors: Herold Christian , Mehring Adolf
Published: February 2008

Die von der EOTA (European Organisation for Technical Approvals) erarbeitete Leitlinie für europäische technische Zulassungen für “Abdichtungen für Böden und Wände in Nassräumen” (ETAG 022) bildet die Grundlage für die technische Beurteilung der Brauchbarkeit von Bausätzen für Abdichtungen in Nassräumen, die zur Erteilung einer europäischen technischen Zulassung (ETA) führt.

Die Leitlinie gliedert sich in drei Teile:

Teil 1: Flüssig aufzubringende Abdichtungen mit oder ohne Nutzschicht

Teil 2: Abdichtungsbahnen

Teil 3: Wasserdichte Platten

Der Teil 1 dieser Leitlinie ist von der Europäischen Kommission angenommen und den Mitgliedstaaten am 18. Juli 2007 zur Veröffentlichung in den jeweiligen Amtssprachen empfohlen worden. Die deutsche Sprachfassung wurde am 31. Oktober 2007 im Bundesanzeiger bekannt gemacht. Auf dieser Grundlage können ab sofort europäische technische Zulassungen (ETAs) erteilt werden. In Deutschland ist die hierfür zuständige Stelle das Deutsche Institut für Bautechnik (DIBt). Anträge sind auf den dafür vorgesehenen Formblättern zu stellen.
Metalloid Cluster Compounds of Germanium: Synthesis – Properties – Subsequent Reactions
Authors: Schnepf Andreas
Published: February 2008

Metalloid cluster compounds represent ideal model compounds that provide an insight into the area between the molecular and the solid state. This borderland is of particular interest especially for metals or semimetals, as a drastic change of the physical properties takes place from the oxidized species (salt, nonconducting) to the bulk phase (metal, semimetal, conducting, semiconducting). For the heavier group 14 elements, this area is also of great technical interest as the module size in the computer industry approaches the nanometre range. This review describes recent achievements in the synthesis of metalloid cluster compounds of germanium. Besides different ligand systems used in synthesis, first examples of subsequent reactions of such cluster compounds are presented and further applications are discussed. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
Structural Diversity in Organotin Compounds Derived from Bulky Monoaryl Phosphates: Dimeric, Tetrameric, and Polymeric Tin Phosphate Complexes
Authors: Murugavel Ramaswamy , Shanmugan Swaminathan , Kuppuswamy Subramaniam
Published: February 2008

Monoaryl phosphates with a bulky aryl substituent have been used to synthesize new organotin clusters and polymers. The equimolar reaction between 2,6‐diisopropylphenylphosphate (dipp‐H2) and Me2SnCl2 in ethanol at 25 °C leads to the formation of [Me2Sn(μ3‐dipp)]n (1), while the reaction of 2,6‐dimethylphenylphosphate (dmpp‐H2) with Me2SnCl2 in either a 1:1 or 2:1 molar ratio proceeds to produce exclusively [Me2Sn(μ‐dmpp‐H)2]n·nH2O (2). Compounds 1 and 2 are 1D polymers with different architectures. In compound 1, the tin atom is five‐coordinate (trigonal bipyramidal). Each dipp ligand bridges three different tin atoms to form an infinite ladder‐chain structure. In 2, each six‐coordinate (octahedral) tin atom is surrounded by four phosphate oxygen atoms originating from four different bridging dmpp‐H ligands, thus forming a spirocyclic coordination polymeric chain. The use of nBu2SnO as the diorganotin source in its reaction with dipp‐H2 leads to the isolation of dimeric [nBu2Sn(μ‐dipp‐H)(dipp‐H)]2 (4), which contains a central Sn2O4P2 unit. There are two chemically different half molecules of 4 in the asymmetric part of the unit cell and hence it actually exists as a 1:1 mixture of [nBu2Sn(μ‐dipp‐H)(dipp‐H)]2 and [nBu2Sn(μ‐dipp)(dipp‐H2)]2 in the solid state. The reaction of the monoorgano tin precursor nBuSn(O)(OH)·xH2O with dipp‐H2 takes place in acetone at room temperature to yield the tetrameric cluster 5, which has different structures in the solution and in the solid state. 31P NMR spectroscopy clearly suggests that 5 has the formula [nBu4Sn4(μ‐O)2(μ‐dipp‐H)8] in solution. The single‐crystal X‐ray diffraction studies in the solid state, however, reveal that compound 5 exists as [nBu4Sn4(μ‐OH)2(μ‐dipp‐H)6(μ‐dipp)2]. The use of compounds 1–4 as possible precursors for the preparation of ceramic tin phosphate materials has been investigated. The thermolysis of 1 at 500 °C leads to the formation of quantitative amounts of Sn2P2O7, while the thermolysis of 2, 3, and 4 under similar conditions results in the formation of SnP2O7. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
Synthesis of Novel Bis(β‐lactam)‐1,3‐diynes by Copper‐Promoted Homo‐ or Cross‐Coupling of Alkynyl‐2‐azetidinones
Authors: Alcaide Benito , Almendros Pedro , Carrascosa Rocío , Rodríguez‐Acebes Raquel
Published: February 2008

Cu(OAc)2in combination with K2CO3(a solid base instead of an amine) was proven to be an extremely effective system for promoting the homocoupling of various (β‐lactam)acetylenes to affordC2‐symmetrical bis(β‐lactam)‐1,3‐diynes, whereas these 2‐azetidinone‐tethered alkynes underwent the Cadiot–Chodkiewicz cross‐coupling reaction with different 2‐azetidinone bromoalkynes to form a variety of unsymmetrical bis(β‐lactam)diynes in good yields. In addition to their potential biological activity, the resulting enantiopure bis(β‐lactam)‐1,3‐diynes can be converted into bis(β‐amino ester)‐1,3‐diynes, which may find use as macrocyclic cavities, as well as chiral ligands. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
A Modulated Tyrosinase Enzyme‐Based Biosensor for Application to the Detection of Dichlorvos and Atrazine Pesticides
Authors: Vidal Juan C. , Bonel Laura , Castillo Juan R.
Published: February 2008

A study was been made of tyrosinase amperometric biosensors for the determination of organophosphorus (dichlorvos) and triazine (atrazine) pesticides. The biosensors are based on the competitive inhibition of tyrosinase (Tyr) by the pesticides. Tyr becomes active when the reduced form of the charge‐transfer mediator (1,2‐naphthoquinone‐4‐sulfonic acid (NQS), 1,2‐naphthoquinone (NQ) and 3,5‐di‐tert‐butyl‐1,2‐benzoquinone (t‐BQ) were tested) are electrochemically generated onto the working electrode surface, which permits modulation of the enzymatic activity. The inhibition is reversible as there is a complete recovery of the current due to enzyme activity without the studied pesticides. The charge‐transfer mediators (the quinonic molecules) and the enzyme were co‐immobilized on the working electrode to obtain reagentless biosensors. Kinetic studies in solution were carried out to compare the efficiency of the measurement mechanism.
Separation and Detection of Narcotic Drugs on a Microchip Using Micellar Electrokinetic Chromatography and Electrochemiluminescence
Authors: Du Yan , Wang Erkang
Published: February 2008

A new approach for fast and sensitive electrochemiluminescence (ECL) detection of narcotic drugs on a microchip after separation by micellar electrokinetic chromatography (MEKC) is presented, taking the cocaine and its hydrolysate ecgonine as the test analytes. The mixture of hydrophilic BMIMBF4 ionic liquid (IL) and sodium dodecyl sulfate (SDS) was used directly as the buffer of MEKC with less noisy baselines, lower electrophoretic current and satisfactory separation performance. This developed microchip MEKC–ECL system was successfully applied to the determination of two very similar narcotics, heroin and codeine, within 100s in urine sample and was demonstrated as a promising method in clinical and forensic analysis.
High‐resolution modeling of isotachophoresis and zone electrophoresis
Authors: Yu Jia‐Wei , Chou Yin , Yang Ruey‐Jen
Published: February 2008

The space–time conservation element and solution element (CESE) method is applied to simulate the ITP and zone electrophoresis (ZE) separation phenomena. The CESE method expresses the governing equation in the integral form of the conservation law, and has a second‐order accuracy in both space and time. The current results show that the CESE solutions for the ITP and ZE phenomena are more accurate than those obtained using conventional numerical schemes, which are characterized by serious numerical diffusion and oscillation. Furthermore, the CESE method suppresses the numerical oscillations or peaks observed in the results obtained using traditional second‐order finite difference schemes. Finally, the results reveal that the CESE method accurately models the sharp boundaries between adjacent ITP samples under steady‐state conditions. Overall, the results presented in this study demonstrate the numerical accuracy of the CESE method and confirm its applicability to the modeling of a range of electrophoretic phenomena.
Effects of Stern layer conductance on electrokinetic energy conversion in nanofluidic channels
Authors: Davidson Christian , Xuan Xiangchun
Published: February 2008

A thermo‐electro‐hydro‐dynamic model is developed to analytically account for the effects of Stern layer conductance on electrokinetic energy conversion in nanofluidic channels. The optimum electrokinetic devices performance is dependent on a figure of merit, in which the Stern layer conductance appears as a nondimensional Dukhin number. Such surface conductance is found to significantly reduce the figure of merit and thus the efficiency and power output. This finding may explain why the recently measured electrokinetic devices performances are far below the theoretical predictions where the effects of Stern layer conductance have been ignored.
Coping with health‐care costs: implications for the measurement of catastrophic expenditures and poverty
Authors: Flores Gabriela , Krishnakumar Jaya , O'Donnell Owen , van Doorslaer Eddy
Published: February 2008

In the absence of formal health insurance, we argue that the strategies households adopt to finance health care have important implications for the measurement and interpretation of how health payments impact on consumption and poverty. Given data on source of finance, we propose to (a) approximate the relative impact of health payments on current consumption with a ‘coping’‐adjusted health expenditure ratio, (b) uncover poverty that is ‘hidden’ because total household expenditure is inflated by financial coping strategies and (c) identify poverty that is ‘transient’ because necessary consumption is temporarily sacrificed to pay for health care. Measures that ignore coping strategies not only overstate the risk to current consumption and exaggerate the scale of catastrophic payments but also overlook the long‐run burden of health payments. Nationally representative data from India reveal that coping strategies finance as much as three‐quarters of the cost of inpatient care. Payments for inpatient care exceed 10% of total household expenditure for around 30% of hospitalized households but less than 4% sacrifice more than 10% of current consumption to accommodate this spending.

Ignoring health payments leads to underestimate poverty by 7–8% points among hospitalized households; 80% of this adjustment is hidden poverty due to coping. Copyright © 2008 John Wiley & Sons, Ltd.
Partially wrong? Partial equilibrium and the economic analysis of public health emergencies of international concern
Authors: Beutels P. , Edmunds W. J. , Smith R. D.
Published: February 2008

We argue that traditional health economic analysis is ill‐equipped to estimate the cost effectiveness and cost benefit of interventions that aim at controlling and/or preventing public health emergencies of international concern (such as pandemic influenza or severe acute respiratory syndrome). The implicit assumption of partial equilibrium within both the health sector itself and – if a wider perspective is adopted – the economy as a whole would be violated by such emergencies. We propose an alternative, with the specific aim of accounting for the behavioural changes and capacity problems that are expected to occur when such an outbreak strikes. Copyright © 2008 John Wiley & Sons, Ltd.
Increased risk of hepatocellular carcinoma among patients with hepatitis C cirrhosis and diabetes mellitus
Authors: Veldt Bart J. , Chen Wendong , Heathcote Jenny E. , Wedemeyer Heiner , Reichen Juerg , Hofmann Peter W. , de Knegt Robert J. , Zeuzem Stefan , Manns Michael P. , Hansen Bettina E. , Schalm Solko W. , Janssen Harry L. A.
Published: February 2008

Recent studies suggest that diabetes mellitus increases the risk of developing hepatocellular carcinoma (HCC). The aim of this study is to quantify the risk of HCC among patients with both diabetes mellitus and hepatitis C in a large cohort of patients with chronic hepatitis C and advanced fibrosis. We included 541 patients of whom 85 (16%) had diabetes mellitus. The median age at inclusion was 50 years. The prevalence of diabetes mellitus was 10.5% for patients with Ishak fibrosis score 4, 12.5% for Ishak score 5, and 19.1% for Ishak score 6. Multiple logistic regression analysis showed an increased risk of diabetes mellitus for patients with an elevated body mass index (BMI) (odds ratio [OR], 1.05; 95% confidence interval [CI], 1.00-1.11;

P

= 0.060) and a decreased risk of diabetes mellitus for patients with higher serum albumin levels (OR, 0.81; 95% CI, 0.63-1.04;

P

= 0.095). During a median follow-up of 4.0 years (interquartile range, 2.0-6.7), 11 patients (13%) with diabetes mellitus versus 27 patients (5.9%) without diabetes mellitus developed HCC, the 5-year occurrence of HCC being 11.4% (95% CI, 3.0-19.8) and 5.0% (95% CI, 2.2-7.8), respectively (

P

= 0.013). Multivariate Cox regression analysis of patients with Ishak 6 cirrhosis showed that diabetes mellitus was independently associated with the development of HCC (hazard ratio, 3.28; 95% CI, 1.35-7.97;

P

= 0.009).

Conclusion:

For patients with chronic hepatitis C and advanced cirrhosis, diabetes mellitus increases the risk of developing HCC.
Randomized comparison of 12 or 24 weeks of peginterferon α-2a and ribavirin in chronic hepatitis C virus genotype 2/3 infection
Authors: Lagging Martin , Langeland Nina , Pedersen Court , Färkkilä Martti , Buhl Mads Rauning , Mφrch Kristine , Dhillon Amar P. , Alsiö Åsa , Hellstrand Kristoffer , Westin Johan , Norkrans Gunnar
Published: February 2008

Previous trials investigating the efficacy of treatment durations shorter than the standard of 24 weeks for chronic hepatitis C virus (HCV) genotype 2/3 infections have yielded discordant results. The aims of this investigator-initiated phase III study were to compare the efficacy of 12 or 24 weeks of treatment and to identify patients suitable for short-term therapy. Three hundred eighty-two genotype 2/3–infected patients [intention-to-treat (ITT) population] at 31 centers in Denmark, Finland, Norway, and Sweden were randomized to 12 or 24 weeks of peginterferon α-2a (180 μg/week) plus ribavirin (800 mg/day). Twelve weeks of therapy was inferior to 24 weeks in the ITT population (sustained viral response [SVR] rates: 59% versus 78%,

P

< 0.0001) and in the subgroups of patients infected with genotype 2 (56% versus 82%,

P

= 0.006) or 3 (58% versus 78%,

P

= 0.0015). These differences were observed regardless of the fibrosis stage. Age and HCV-RNA levels on days 7 and 29 were independent predictors of SVR. Short-term treatment was useful in patients < 40 years old, especially if HCV-RNA was undetectable on day 29, and also in patients ≥ 40 years old, provided that HCV-RNA was below 1000 IU/mL on day 7 in addition to being undetectable on day 29. If neither of these two criteria were met for patients ≥ 40 years old, 24 weeks of therapy was superior (

P

< 0.0001).

Conclusion:

Peginterferon/ribavirin treatment for 12 weeks in HCV genotype 2/3 infection is overall inferior to 24 weeks of treatment but may be useful in some patients with a rapid initial clearance of virus.