bluuebunny/crossref_metadata_2025 huggingface dataset:
Quantitative structure–retention relationships for ionic and non‐ionic compounds in biopartitioning micellar chromatography
Authors: Escuder‐Gilabert L. , Sagrado S. , Villanueva‐Camañas R. M. , Medina‐Hernández M. J.
Published: February 2005

Quantitative structure–retention relationships, QSRRs, represent a powerful tool in chromatography. The objectives of QSRR studies are to predict the chromatographic retention behaviour of solutes based on their structural properties, to elucidate retention mechanisms, to optimize the separation of complex mixtures or to prepare experimental designs. In this paper, using the retention factors of 151 structurally unrelated solutes that cover a wide range of hydrophobicity, molecular size, hydrogen bonding properties and ionization degrees obtained in biopartitioning micellar chromatography (BMC) at different Brij35 micellar concentrations, several multivariate QSRR models are tested. It is demonstrated that the chromatographic retention of any molecule in BMC, independently of its family, can be adequately described by its hydrophobicity (expressed as log P) and its anionic and cationic total molar charge (expressed as αA and αB). Copyright © 2004 John Wiley & Sons, Ltd.
Approaches to correct device malposition in percutaneous PFO closure: Anatomical and technical implications
Authors: Muench Andreas , Boccalandro Fernando , Ellis Keith , Smalling Richard W.
Published: February 2005

We describe three patients with initial failure of transcatheter patent foramen ovale closure. Two patients had residual defects successfully closed during the initial session, and one patient had a persistent shunt, which was corrected at a later time. Anatomical and technical considerations and the role of intracardiac ultrasound are discussed. Catheter Cardiovasc Interv 2005;64:338–344. © 2005 Wiley‐Liss, Inc.
Transcatheter closure of a 22 mm patent ductus arteriosus with an Amplatzer atrial septal occluder
Authors: Spies Christian , Ujivari Franz , Schräder Rainer
Published: February 2005

Transcatheter techniques for closure of patent ductus arteriosus (PDA) have been used for almost 40 years. We report a case of a 24‐year‐old female with a 22 mm PDA, congestive heart failure, and atrial fibrillation. She underwent transcatheter PDA closure with an Amplatzer atrial septal occluder (ASO). Following the procedure, she developed hemolysis due to a large residual shunt. However, the shunt gradually resolved until complete closure was achieved within 8 months. An attempt to restore sinus rhythm with electrical cardioversion was successful and the patient is now, 2 years after procedure, in New York Heart Association functional class I. Off‐label use of an ASO for closure of a very large PDA yielded an excellent clinical result. Catheter Cardiovasc Interv 2005;64:352–355. © 2005 Wiley‐Liss, Inc.
Left ventricular conditioning in the elderly patient to prevent congestive heart failure after transcatheter closure of atrial septal defect
Authors: Schubert S. , Peters B. , Abdul‐Khaliq H. , Nagdyman N. , Lange P.E. , Ewert P.
Published: February 2005

Transcatheter closure of atrial septal defects (ASDs) is a safe and effective treatment. Over the past years, an increasing number of elderly patients (age > 60 years) have been admitted for transcatheter closure to prevent ongoing congestive heart failure from volume overload. However, recent data point to the risk of serious acute left ventricular dysfunction leading to pulmonary edema immediately after surgical or transcatheter ASD closure in some patients. In this study, we used a technique described before to recognize in advance patients at risk of left heart failure after ASD closure. Those patients at risk were then treated with preventive conditioning medication for 48–72 hr before definitive transcatheter ASD closure was performed. Fifty‐nine patients aged over 60 years (range, 60–81.8 years; median, 68 years) were admitted to our institution for transcatheter closure of an atrial septal defect. All patients received evaluation of atrial pressures before and during temporary balloon occlusion of the ASD. Patients with left ventricular restriction due to increased mean atrial pressures (> 10 mm Hg) during ASD occlusion received anticongestive conditioning medication with i.v. dopamine, milrinone, and furosemide for 48–72 hr before definitive ASD closure with an Amplatzer septal occluder was performed. In 44 patients without any signs of left ventricular restriction, ASD closure was performed within the first session. Fifteen (25%) out of 59 patients showed left ventricular restriction. In the majority of patients with LV restriction, the mean left atrial pressures with occluded ASD were significantly decreased after 48–72 hr of conditioning medication. Definitive ASD closure was then performed in a second session. Only two patients received a fenestrated 32 mm Amplatzer occluder due to persistent increased atrial pressures > 10 mm Hg even after conditioning medication. There were no significant differences in shunt, device size, or defect size between the two groups. Balloon occlusion of atrial septal defects identifies patients with left ventricular restrictive physiology before ASD closure. Intravenous anticongestive conditioning medication seems to be highly effective in preventing congestive heart failure after interventional closure of an ASD in the elderly patient with a restrictive left ventricle. Catheter Cardiovasc Interv 2005;64:333–337. © 2005 Wiley‐Liss, Inc.
Endovascular treatment of basilar artery stenosis with drug‐eluting stent: A case report and literature review
Authors: Lee Sang Hak , Jung Jae Hun , Shim Won‐Heum
Published: February 2005

Symptomatic basilar artery stenosis can be treated with stents. However, it still has limitations such as technical difficulty and restenosis. We describe a 61‐year‐old man with episodic vertigo and significant basilar artery stenosis, who was successfully treated with drug‐eluting stent. At 6 month follow‐up, cerebral angiography revealed patent basilar artery. Catheter Cardiovasc Interv 2005;64:296–300. © 2005 Wiley‐Liss, Inc.
Nanocap‐Shaped Tin Phthalocyanines: Synthesis, Characterization, and Corrosion Inhibition Activity
Authors: Beltrán Hiram I. , Esquivel Raquel , Lozada‐Cassou Marcelo , Dominguez‐Aguilar Marco A. , Sosa‐Sánchez Arturo , Sosa‐Sánchez Jose L. , Höpfl Herbert , Barba Victor , Luna‐García Rolando , Farfán Norberto , Zamudio‐Rivera Luis S.
Published: February 2005

Thermal and microwave reactions between [PcSnIVCl2] (1) and the potassium salts of eight fatty acids (2 a–h) led to cis‐[(RCO2)2SnIVPc] compounds (3 a–h) in yields ranging from 54 to 90 %. Compounds 3 a–h were fully characterized by elemental analysis, spectroscopy (IR, UV/Vis, multinuclear NMR), and seven X‐ray diffraction structures, whereby two different allotropes were observed in two cases. The two carboxylates in 3 have a cis anisobidentate binding mode, octacoordination of the tin atoms with square‐antiprismatic geometry, and π‐electron‐rich nanocap shapes. On account of the latter characteristics, 3 a–h compounds have anticorrosion properties. LPR and Tafel electrochemical methods were used to characterize the behavior of these derivatives in naturally aerated sour brine, which is a common environment in petroleum production and refinery operations. The measurement of the corrosion rate of carbon steel AISI 1018 in the presence of 3 a–h (500 ppm) gave efficiencies of 61–87 % for the inhibitor performance. Of the different derivatives examined, compounds 3 e and 3 h were the most effective corrosion inhibitor prototypes.
Ligand Functionality as a Versatile Tool to Control the Assembly Behavior of Preformed Titania Nanocrystals
Authors: Polleux Julien , Pinna Nicola , Antonietti Markus , Hess Christian , Wild Ute , Schlögl Robert , Niederberger Markus
Published: February 2005

Nanoparticle powders composed of surface‐functionalized anatase crystals with diameters of about 3 nm self‐organize into different structures upon redispersion in water. The assembly is directed by a small amount of a low‐molecular‐weight functional ligand (the “assembler”) adsorbed on the surface of the nanoparticles. The ligand functionality determines the anisotropy of the resulting structures. Multidentate ligands, such as trizma ((HOCH2)3CNH2) and serinol ((HOCH2)2CNH2), with a chargeable terminal group preferentially induce the formation of anisotropic nanostructures several hundreds of nanometers in total length, whereas all the other investigated ligands (ethanolamine H2N(CH2)2OH, glycine hydroxamate H2NCH2CONHOH, dopamine (OH)2C6H3(CH2)2NH3Cl, tris (HOCH2)3CCH3) mainly lead to uncontrolled agglomeration. Experimental data suggests that the anisotropic assembly is a consequence of the water‐promoted desorption of the organic ligands from the {001} faces of the crystalline building blocks together with the dissociative adsorption of water on these crystal faces. Both processes induce the preferred attachment of the titania nanoparticles along the [001] direction. The use of polydentate and charged ligands to functionalize the surface of nanoparticles thus provides a versatile tool to control their arrangement on the nanoscale.
Efficient Solid‐Phase Synthesis of Highly Functionalized 1,4‐Benzodiazepin‐5‐one Derivatives and Related Compounds by Intramolecular Aza–Wittig Reactions
Authors: Gil Carmen , Bräse Stefan
Published: February 2005

Due to their widespread biological activities and favorable pharmacokinetic properties, benzodiazepines were among the first classes of small molecules to be synthesized on solid supports. Since then, there have been numerous reports on the synthesis of similar skeletons. We have employed the T1 triazene linker to yield 1,4‐benzodiazepin‐5‐one. Starting from various substituted triazene resins, cleavage in the presence of an azide donor, such as trimethylsilylazide, gave rise to aryl azides. Intramolecular aza–Wittig reactions produced the appropriately functionalized N‐heterocycles. By using this route, the natural product deoxyvasicinone and related compounds were prepared.
Cover Picture: Structure Determination of Homoleptic AuI, AgI, and CuI Aryl/Alkylethynyl Coordination Polymers by X‐ray Powder Diffraction (Chem. Eur. J. 6/2005)
Authors: Chui Stephen S. Y. , Ng Miro F. Y. , Che Chi‐Ming
Published: February 2005

Polymeric structures are found for one of a series of homoleptic coordination polymers [(RCCM)n] (M=CuI, AgI, and AuI) that have been structurally characterized. The paper by C.‐M. Che et al. on page 1739 ff. describes the characterization by means of X‐ray powder diffraction measurements of several such complexes. Solid‐state properties including photoluminescence, ν(CC) stretching frequencies and thermal stability of these polymeric systems are discussed in the context of the determined structures. The picture shows the structure and diffraction data for the polymer chain [(PhCCCu)∞].
RhoA, RhoB, RhoC, Rac1, Cdc42, and Tc10 mRNA levels in spinal cord, sensory ganglia, and corticospinal tract neurons and long‐lasting specific changes following spinal cord injury
Authors: Erschbamer Matthias K. , Hofstetter Christoph P. , Olson Lars
Published: February 2005

Inhibition of RhoA has been shown to enhance axonal regeneration following spinal cord injury. Here we mapped mRNA expression patterns of RhoA, B, and C, Rac1, Cdc42, and Tc10 in spinal cord, sensory ganglia, and sensorimotor cortex in uninjured rats, and following spinal cord injury or sham laminectomy. In the intact spinal cord, neurons displayed high levels of Rac1, Cdc42, and Tc10 mRNA hybridization signal. GFAP‐immunoreactive astrocytes expressed primarily RhoB and Rac1, while oligodendrocyte‐like cells expressed RhoA, Rac1, and Cdc42. Injury caused profound, long‐lasting upregulation of RhoA, Rac1, Cdc42, and Tc10 mRNA in the spinal cord, while RhoB was modestly increased and RhoC did not change. GFAP‐immunoreactive reactive astrocytes exhibited a dramatic increase of RhoA mRNA expression along with increases of Rac1 and Cdc42. Injury also led to elevation of RhoA, Cdc42, and Tc10 in neurons and modest increases of RhoA, Rac1, and Tc10 in oligodendrocyte‐like cells. Laminectomy caused similar, but less pronounced alterations of investigated mRNA species. In dorsal root ganglia neuronal RhoA, Rac1, Cdc42, and Tc10 mRNA levels were increased similarly by spinal cord injury and sham surgery. The CST pyramidal cells expressed Tc10 mRNA and the CST itself was Tc10‐immunoreactive. Tc10‐immunoreactivity disappeared distal to injury. We conclude that there are gene‐specific patterns of expression of the six different Rho‐GTPases in normal spinal cord and dorsal root ganglia, and that specific changes of temporal and spatial expression patterns occur in response to spinal cord injury, suggesting different roles of these GTPases in the cellular sequelae of CNS injury. J. Comp. Neurol. 484:224–233, 2005. © 2005 Wiley‐Liss, Inc.
Network traffic prediction based on a new time series model
Authors: Yin Hao , Lin Chuang , Sebastien Berton , Li Bo , Min Geyong
Published: February 2005

Fast and accurate methods for predicting traffic properties and trend are essential for dynamic network resource management and congestion control. With the aim of performing online and feasible prediction of network traffic, this paper proposes a novel time series model, named adaptive autoregressive (AAR). This model is built upon an adaptive memory‐shortening technique and an adaptive‐order selection method originally developed by this study. Compared to the conventional one‐step ahead prediction using traditional Box–Jenkins time series models (e.g. AR, MA, ARMA, ARIMA and ARFIMA), performance results obtained from actual Internet traffic traces have demonstrated that the proposed AAR model is able to support online prediction of dynamic network traffic with reasonable accuracy and relatively low computation complexity. Copyright © 2005 John Wiley & Sons, Ltd.
XTbx1 is a transcriptional activator involved in head and pharyngeal arch development in Xenopus laevis
Authors: Ataliotis Paris , Ivins Sarah , Mohun Timothy J. , Scambler Peter J.
Published: February 2005

The development of pharyngeal arch derivatives in mouse and zebrafish embryos depends on the activity of the transcription factor Tbx1. We cloned the Xenopus laevis orthologue of Tbx1 (XTbx1) and show that the pattern of expression is similar to that in other vertebrate species. Zygotic transcripts are first detected shortly after the mid‐blastula transition and are localized to the presumptive mesoderm at mid‐gastrula stages. XTbx1 expression persists in the lateral plate mesoderm at neurula stages and is found in the pharyngeal arches and otic vesicles from early tail bud stages onward. We demonstrate that XTbx1 is a transcriptional activator and that this trans‐activation requires the C‐terminal region of the protein. A dominant interfering mutant of XTbx1 disrupts the development of Xenopus head structures and pharyngeal arch derivatives. Lineage labeling reveals a requirement for XTbx1 function in cells that contribute to the pharyngeal mesoderm and for fgf8 expression. Developmental Dynamics 232:979–991, 2005. © 2005 Wiley‐Liss, Inc.
Cloning of cDNAs and the differential expression of A‐type cyclins and Dmc1 during spermatogenesis in the Japanese eel, a teleost fish
Authors: Kajiura‐Kobayashi Hiroko , Kobayashi Tohru , Nagahama Yoshitaka
Published: February 2005

We cloned A‐type cyclins (cyclins A1 and A2) and Dmc1 cDNAs from the eel testis. Cyclin A1 mRNA was predominantly expressed in the livers, ovaries, and testes of the eels. In contrast to cyclin A1 mRNA, a very high expression of cyclin A2 mRNA was observed in the brains, livers, kidneys, spleens, ovaries, and testes of the eels. Dmc1 mRNA was predominantly expressed in the testes and ovaries; expression in the brain was also detected. In the eel testis, a few type‐A spermatogonia incorporating 5‐bromo‐2′‐deoxyuridine (BrdU) were seen before the initiation of spermatogenesis by hormonal induction. On day 1 after hormonal induction, the number of BrdU‐labeled spermatogonia increased remarkably, and after 3 and 6 days, many labeled type‐B spermatogonia were also observed. The expression of cyclin A2 increased 1 day after the induction of spermatogenesis and reached a plateau after 6 days, when many type‐B spermatogonia with high proliferative activity were found. In contrast, the expression of cyclin A1 mRNA was detected after 9 days, coincident with the first appearance of spermatocytes. Cyclin A1 mRNA was localized in germ cells of all stages, from primary spermatocytes to round spermatids, whereas cyclin A2 mRNA was specifically localized in spermatogonia, secondary spermatocytes, round spermatids, and testicular somatic cells, including Sertoli cells. Dmc1 was localized only in the earlier stages of primary spermatocytes; before this stage, cyclin A1 mRNA was not detectable. Overall, cyclin A2, Dmc1, and cyclin A1 are expressed in spermatogenic cells sequentially before and during meiosis in the eel testis. Developmental Dynamics 232:1115–1123, 2005. © 2005 Wiley‐Liss, Inc.
Iron(II) Formate [Fe(O2CH)2]·1/3HCO2H: A Mesoporous Magnet − Solvothermal Syntheses and Crystal Structures of the Isomorphous Framework Metal(II) Formates [M(O2CH)2]·n(Solvent) (M = Fe, Co, Ni, Zn, Mg)
Authors: Viertelhaus Martin , Adler Peter , Clérac Rodolphe , Anson Christopher E. , Powell Annie K.
Published: February 2005

Recrystallisation of iron(II) formate dihydrate from formic acid under solvothermal conditions results in single‐crystals of the iron(II) formate, α‐Fe(O2CH)2·1/3HCO2H. The crystal structure of this phase has been determined by X‐ray diffraction and reveals an open framework structure with formic acid molecules occupying channels in the lattice which is stable even after removal of the solvent molecules. Magnetic susceptibility and Mössbauer measurements show that the compound undergoes 3D magnetic ordering below TC = 16 K. α‐Fe(O2CH)2·1/3HCO2H and the corresponding magnesium, cobalt, nickel and zinc formates form an isomorphous series. In contrast to the iron compound, the magnetic behaviour of the cobalt analogue is dominated by antiferromagnetic interactions. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)
Formation of ArPdXL(amine) Complexes by Substitution of One Phosphane Ligand by an Amine in trans‐ArPdX(PPh3)2 Complexes
Authors: Jutand Anny , Négri Serge , Principaud Anna
Published: February 2005

Amines (piperidine, morpholine, diisopropylamine, terbutylamine), which may be used as bases in copper‐free palladium‐catalyzed Sonogashira reactions, substitute one phosphane PPh3 in trans‐ArPdX(PPh3)2 complexes (Ar = Ph, 4‐NC–C6H4, 4‐MeOC–C6H4, 2‐thienyl; X = I, Br, Cl) to generate ArPdX(PPh3)(amine) complexes in a reversible reaction whose equilibrium constant is determined in chloroform, THF, and DMF. The equilibrium constant depends on Ar, X, the basicity, and the steric hindrance of the amine. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)
Vanadium(IV and V) Complexes of Schiff Bases and Reduced Schiff Bases Derived from the Reaction of Aromatic o‐Hydroxyaldehydes and Diamines: Synthesis, Characterisation and Solution Studies
Authors: Correia Isabel , Pessoa João Costa , Duarte M. Teresa , da Piedade M. Fátima Minas , Jackush Tamás , Kiss Tamás , Castro M. Margarida C. A. , Geraldes Carlos F. G. C. , Avecilla Fernando
Published: February 2005

Several sal2en‐type reduced Schiff bases have been prepared from the reaction of 2 equiv. of salicylaldehyde (or derivatives) with ethylenediamine followed by reduction with NaBH4 and subsequently characterised. The water‐soluble ligands (SO3‐sal)2en and R(SO3‐sal)2en (SO3‐sal = salicylaldehyde‐5‐sulphonate) have been studied by pH potentiometry and 1H NMR spectroscopy and the protonation constants of R(SO3‐sal)2en have been determined. The Schiff bases are more susceptible to hydrolysis than the corresponding reduced Schiff bases. The crystal structures of H2(o‐van)2en and KH(o‐van)2en (o‐van = o‐vanillin) have been determined by X‐ray diffraction. The vanadium(IV) complexes have been prepared and characterised by magnetic measurements and IR, UV/Vis and EPR spectroscopy. The colours, magnetic susceptibilities and IR spectra of the new vanadium(IV) complexes of the reduced Schiff bases now obtained suggest oligomeric/polymeric structures for the compounds while the corresponding VIVO–Schiff‐base complexes are monomeric.The complexation of [VIVO]2+ and [VVO2]+ with R(SO3‐sal)2enin aqueous solution has been studied by pH potentiometry, UV/Vis as well as by EPR spectroscopy for the VIVO system and 1H and 51V NMR spectroscopy for the VVO2 system. Complex formation constants have been determined and binding modes have been proposed. N,N′‐ethylenebis(pyridoxylaminato) (Rpyr2en) has also been obtained and the structure of Na[VVO2(Rpyr2en)]·CH3OH·3H2O determined by X‐ray diffraction. The Rpyr2en2– ligand coordinates through both the N‐amine and O‐phenolate moieties in a symmetrical α‐cis type coordination mode, i.e. with both O‐phenolato donors cis to the O‐oxo atoms and trans to each other. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)
Synthesis, Characterisation of Carbon‐Bridged (Diphenolato)lanthanide Complexes and Their Catalytic Activity for Diels–Alder Reactions
Authors: Xu Xiaoping , Ma Mengtao , Yao Yingming , Zhang Yong , Shen Qi
Published: February 2005

The synthesis and structures of new lanthanide complexes supported by the carbon‐bridged diphenolato ligand 2,2′‐methylenebis(6‐tert‐butyl‐4‐methylphenolato) (MBMP2–) are described. Reactions of anhydrous lanthanide trichlorides with Na2MBMP in a 1:2 molar ratio in THF at room temperature afforded the corresponding “ate” (diphenolato)lanthanide complexes [(THF)nLn(MBMP)2Na(THF)2] [Ln = Nd (1), Sm (2),n= 2; Ln = Yb,n= 1 (3)]. Recrystallisation of complexes1–3from toluene in the presence of DME gave the discrete ion‐pair complexes [(MBMP)2Ln(THF)2][Na(DME)2(THF)2] [Ln = Nd (4), Sm (5), Yb (6)]. These complexes have been fully characterised. The single‐crystal structural analyses of1,3and6revealed that the coordination geometries of the lanthanide ions can be best described as distorted octahedral in complexes1and6and distorted trigonal‐bipyramidal in complex3. It was found that these lanthanide complexes are able to act as Lewis acids to catalyse the Diels–Alder reactions of cyclopentadiene with substituted dienophiles with good activity and stereoselectivity. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)
A Study of the Magnetic Structure of LaMn2O5 from Neutron Powder Diffraction Data
Authors: Muñoz Angel , Alonso Jose A. , Casais María T. , Martínez‐Lope María J. , Martínez Jose L. , Fernández‐Díaz María T.
Published: February 2005

Polycrystalline LaMn2O5 has been studied by neutron powder diffraction in conjunction with magnetization data. The crystal structure of this oxide contains infinite chains of edge‐sharing Mn4+O6 octahedra, interconnected by Mn3+O5 pyramids and LaO8 units. Susceptibility measurements show that LaMn2O5 presents an antiferromagnetic order below a TN value of about 31 K. Neutron diffraction experiments confirm the long‐range ordering below this temperature in a magnetic structure characterized by the propagation vector k = (0,0,1/2). The magnetic arrangement is defined by the basis vectors (Gx,Ay,0) and (0,0,C′z) for the Mn4+ and Mn3+ ions, respectively. At 3.5 K, the magnetic moments are 2.59(4) and 1.61(7) μB for the Mn3+ (4h site) and Mn4+ ions (4f site), respectively. Superexchange interactions between the Mn4+ ions through Mn4+–O–Mn4+ paths are considered in order to explain the commensurate character of the magnetic structure in comparison with the incommensurate structures observed for most of the RMn2O5 (R = rare earth metal) compounds. A spin‐glass‐type behaviour, which probably involves the short‐range order in the Mn3+ sublattice, is observed above TN. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)
New Complexes of Divalent Thulium with Substituted Phospholyl and Cyclopentadienyl Ligands
Authors: Nief François , de Borms Brice Tayart , Ricard Louis , Carmichael Duncan
Published: February 2005

In order to try to stabilise the TmII ion with phospholyl ligands lacking methyl groups at the 3 and 4 positions, the following ligand precursors were prepared: sodium 2,5‐di‐tert‐butylphospholyl [Na(Htp)] (3) and sodium 2,5‐bis(trimethylsilyl)phospholyl [Na(Hsp)] (8). Because of its similar steric bulk, we also decided to use sodium di‐tert‐butylcyclopentadienyl [NaCptt] (9) as a ligand precursor. Compound 3 was obtained by sodium cleavage of the P–P bond of 2,5,2′,5′‐tetra‐tert‐butyl‐1,1′‐diphosphole (2). Halogen‐lithium exchange in 1,4‐diiodo‐1,4‐bis(trimethylsilyl)buta‐1,3‐diene (4) followed by reaction with PhPCl2 afforded 1‐phenyl‐2,5‐bis(trimethylsilyl)phosphole (5). Treatment of 5 with lithium metal followed by oxidative treatment with iodine gave 2,5,2′,5′‐tetrakis(trimethylsilyl)‐1,1′‐diphosphole (7) which could be transformed into 8 by treatment with sodium. Treatment of 3, 8 and 9 with [TmI2(THF)3] in diethylether yielded three new organothulium(II) complexes [Tm(Htp)2(THF)] (10), [Tm(Hsp)2(THF)] (11) and [Tm(Cptt)2(THF)] (12), respectively, which could be isolated pure as crystalline solids in low to moderate yields. Complexes 10, 11 and 12 were studied by X‐ray crystallography and their structures compared with those of two previously described complexes, [Tm(Cp′′)2(THF)] 1 [Cp = 1,3‐bis(trimethylsilyl)cyclopentadienyl] and [Tm(Dtp)2(THF)] (13) (Dtp = 3,4‐dimethyl‐2,5‐di‐tert‐butylphospholyl). Although the phospholyl ligands may be slightly more bulky than their cyclopentadienyl counterparts, the structures of 1, 10, 11 and 12 are remarkably similar and are substantially different from that of the more bulky 13. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)
Posterior evaluation of odour intensity in gas chromatography–olfactometry: comparison of methods for calculation of panel intensity and their consequences
Authors: Pet'ka Ján , Ferreira Vicente , Cacho Juan
Published: February 2005

Four methods of panel intensity calculation were compared for 13 compounds, studied on five concentration levels using gas chromatography–olfactometry. All the methods produced sigmoidal dose–response functions or fractions of sigmoid, when the missing observations were replaced with zero. In contrast, panel intensities calculated only from the reported percepts provided predominantly linear plots. The linearity of such calibration curves can be additionally improved, either by employing a panel of similar dynamic range or by replacing missing observations with predicted (censored) values. Strong scale differences were observed. The panel intensity of methyl benzoate changed rapidly over a very small range of concentrations. Conversely, a very small change of panel intensity was observed for sotolon in a concentration range of three orders of magnitude. Such differences relate closely to the Stevens' slope, in the form of exponential growth function. A systematic decrease of panel intensity was observed for some volatiles at the highest concentration levels. Some of these observations could be explained with the help of current neurobiological knowledge. Copyright © 2005 John Wiley & Sons, Ltd.
Mass law effects of adenosine triphosphate on Na, K, Mg and Ca binding by rat liver microsomes
Authors: Sanui Hisashi , Pace Nello
Published: February 2005

The effect of ATP on the binding of Na, K, Mg and Ca ions by rat liver microsomes was investigated. Addition of increasing amounts of ATP to a suspension of microsomes in an ionic medium containing these cations caused a marked decrease in divalent cation binding and a concomitant increase in monovalent cation binding by the microsomes. The strong nonbiological complexing agent EDTA produced qualitatively similar but quantitatively greater changes in binding. Although ATP‐dependent binding of monovalent cations has been interpreted by other investigators in terms of an ATPase system and the formation of a hypothetical monovalent cation binding intermediate, the present data demonstrate that the role of ATP may also be reasonably explained in terms of mass law interactions of the various known solute species and fixed membrane binding sites involved.
A study of the crustacean axon repetitive response: II. The effect of cations, sodium, calcium (magnesium), potassium and hydrogen (pH) in the external medium
Authors: Wright Ernest B. , Tomita Tadao
Published: February 2005

The effects of sodium, calcium, potassium (magnesium), potassium, and hydrogen (pH) ion concentration in the external medium on the repetitive response and the transmembrane electrical parameters of the crustacean axon have been investigated. (1) The action potential is reduced with decrease in sodium ion concentration, the relationship is linear if the spike voltage is plotted against the log (Na0). The action potential amplitude does not increase significantly, above 135 mv, attained at Na0 = 452 mM, if Na0 is increased. (2) The repetitive response and oscillatory activity in general disappears as the sodium concentration is reduced to less than 150 mM. (3) The critical firing level increases with decrease in sodium, the relationship linear with respect to log (Nao). (4) The positive after potential amplitude is not affected by the sodium concentration. (5) The membrane resistance is not affected by sodium concentration. (6) Calcium lack results in decreased critical firing level and spontaneous firing, followed by a total and irreversible loss of excitability. The membrane resistance is markedly decreased. Polarizing current, if applied early after the onset of the calcium lack effect, may restore, at least partially, the excitability phenomenon. (7) Calcium excess increases membrane resistance, depresses excitability. Calcium concentration of 150 mM abolishes the repetitive response. (8) There is a 3.3+: 1 ratio Na:Ca for threshold level of repetitive response. Lower ratio figures, by reducing Na or increasing Ca or both, eliminates repetition. Increasing the ratio figure by increasing sodium or decreasing calcium or both augments oscillatory activity. This ratio is constant between the limits 400 mM Na:125, Ca to 90 mM Na:25 mM Ca. (9) Magnesium may substitute for calcium, the Na:Mg ratio for repetitive response threshold is 3.3:2. (10) Repetitive firing may be elicited over a wide range of pH values 4.2–10.5; membrane potential and resistance values decline invariably at pH values above 9.5 and below 4.5. (11) Repetitive firing is enhanced by increasing pH values, depressed by reducing pH values. (12) Effect of excess potassium produces depolarization, reduced membrane resistance, inactivation and abolition of repetitive firing, may be relieved by applied hyperpolarization. (13) Potassium lack results in membrane potential and resistance irreversible decline, permanent inactivation, total loss of excitability. Partial restoration by strong hyperpolarization if applied before effect is complete. Potassium replacement in solution only slows or temporarily arrests the overall membrane deterioration. (14) Conclusions ‐ sodium controls spike, potassium controls after potential, calcium (magnesium) controls membrane permeability, pH controls amount of available ionized calcium. Repetitive firing requires proper ratio 3.3/1 of (Nao)/(Ca0), pH above 7.6 and potassium at 15 mM in solution.
The activity of selected soluble enzymes in the avian nasal salt gland
Authors: McFarland L. Z. , Martin K. D. , Freedland R. A.
Published: February 2005

Ten adult western gulls (Larus occidentalis) ranging in weight from 761–1,004 gm were studied. The gulls were fed 3% NaCl in their drinking water. They were killed by decapitation, and the salt glands, weighing 0.51–0.78 gm were cooled, homogenized in 0.14 M KCl, centrifuged at 0–4°C at 20,000 × G for 30 minutes and the supernatant used for all enzymes assays. All assays were conducted at 25°C by observing the changes in absorbancy with time using a Gilford Multiple Absorbance Recorder. The enzymes were assayed by measuring either the appearance or disappearance of NADH or NADPH at 340 mμ. The average units of enzyme activity (the amount of enzyme required to form 1 μM of substrate per minute ) per gram of salt gland were as follows: phosphoglucomutase, 0.62; glucose‐6‐phosphate dehydrogenase, 1.40; aldolase, 2.86; lactic dehydrogenase, 90.1; isocitric dehydrogenase, 5.08; malic enzyme, 0.92; glutamic‐oxaloacetic transaminase, 100.5; and glutamic‐pyruvic transaminase, 0.50. The protein content of the salt glands varied from 62.5–87.6 mg protein/gm. On the basis of an adjusted calculation of energy yields from the glycolytic scheme and the Krebs cycle, it would appear that only one‐third of the energy derived from these pathways would be necessary to maintain the maximum rate of salt secretion, leaving the other two‐thirds for other cellular processes. Glutamate metabolism may also be important as an energy source in the salt gland.
Metabolic adaptation and the regulation of metabolism of a flagellate protozoan
Authors: Cantor Marvin H. , James Thomas W.
Published: February 2005

Evidence is presented indicating metabolic adaptation for the utilization of propionate and butyrate by the flagellate, Polytomella agilis. The existence of a lag phase prior to exponential growth, and the inability of acetate‐grown cells to readily oxidze these substrates support ths concluson.

Two aspects of metabolic regulation are discussed. The inhibitory effect of azide on the growth and on oxidation of propionate and butyrate implicates the importance of ATP availability in the control mechanism.

Oxidative metabolism is regulated to maintain a constant extent of substrate oxidation regardless of growth conditions. The Qo2 is related to the carbon source for growth, and not on the substrate to be oxidized. The rate of substrate utilization by adapted cells is less than that of unadapted cells.
Systemic effects of epinephrine in the frog
Authors: Watlington Charles O. , Burke Patrick K. , Campbell Addison D. , Huf Ernst G.
Published: February 2005

The intact frog (R. pipiens) is both very sensitive to i.v. injection of l‐epinephrine (E) in small amounts (a few micrograms), and very tolerant to large doses (several milligrams) of the hormone. A small dose increased the P.D. and the short circuit current (Is) in skin, and strongly increased the strength of auricular contraction of the heart in vivo; ventricular contractions decreased, and heart rate remained normal. Large doses of E depressed P.D. and Is after, occasionally, elevating both for a brief period following treatment. The mucous glands of the skin emptied their content shortly after E, then began to fill again with secretory materials in spite of uninterrupted E infusions. Ventricular and auricular contractions were remarkably little altered and there were no significant changes in heart rate. Changes were seen, however, in the ECG, e.g.: inversion of the P and T waves. No alteration in the QRS complex or in the rhythm was ever noted. Serum glucose remained within normal limits. A transient calorigenic effect, lasting for 10–20 minutes occurred, in which the O2 consumption rose from a normal of 6 to 7 ml/100 g/hr to several times this value. Unanesthetized frogs tolerated without great harm 10 mg of E given s.c. within one hour. Signs of prostration and a moderate increase in respiration were noted for some time following treatment. Great tolerance of frogs to hormones which do play a physiological role is also known for thyroxine and insulin, but is especially notable for epinephrine which is least tolerated by warmblooded animals treated with large doses of E. The reasons for these species differences are unknown.
Modification of cardiac and respiratory rhythms in crayfish following carbohydrate chemoreception
Authors: Ashby Ebert A. , Larimer James L.
Published: February 2005

Reflex inhibitions of cardiac and ventilation rates of the crayfish, Procambarus simulans, have been used as indices of chemical sensitivity in an assay of configurational specificity among 30 carbohydrates and related compounds. Cardiac activity was determined from electrocardiograms and the bilateral ventilation frequencies were recorded with low‐level pressure transducers. The responses were followed simultaneously on a commercial polygraph. Test solutions were introduced into the region of the branchial chamber with the ventilation stream. Positive responses consisted of inhibition or cessation of activity in both systems.

Analysis of results from sugars with various configurations involving carbons 2, 4, and 5 of the pyranose ring indicated these positions were not critical in evoking the responses. Sugars lacking carbon 6, e.g., D‐xylose and D‐arabinose, were also effective stimuli. Blocking of the ‐OH at the C1, as found in glycosides, converts a stimulating configuration into a non‐stimulating one, except where the substituent contains a free ‐OH group at the terminal carbon, e.g., maltose or cellobiose. Stimulating disaccharides were all 1–4 glycosides and possessed a free ‐OH at C1. The disaccharides with linkages other than 1–4 were non‐stimulatory, e.g., gentiobiose, trehalose, and melibiose, as were the trisaccharides, raffinose and melizitose. Linear and cyclic polyhydroxy alcohols, e.g., erythritol and inositol, and short chain aldoses, e.g., erythrose, were also ineffective.

Stimulation of the receptors seems to require the pyranose ring and access to a free hydroxyl group on C1. Isolation of the receptor and measurement of single unit activity are required before incontrovertible statements of specificity can be made. A basis for such investigations has been made.
Photodynamic and fluorochromic properties of the antibiotic actinomycin D
Authors: Zhdanov Victor M. , Yershov Felix I.
Published: February 2005

Actinomycin D was studied as a photodynamic agent and fluorochrome. With Venezuelan equine encephalitis virus propagated in chick fibroblasts, it was shown that actinomycin D induces both direct and indirect photoactivation of the virus. Some capacity of antibiotic‐treated and irradiated virus to produce plaques larger than usual was not retained with passage of virus isolated from large plaques. Cells stained with actinomycin D exhibited a weak brownish fluorescence of nuclear structure.
The effect of bile salts on tissue ATP levels of everted sacs of rat and hamster ileum
Authors: Faust Robert G. , Wu Shih‐Min Liu
Published: February 2005

The results of this investigation indicate that with a progressive increase in the initial bile salt concentration within the mucosal and serosal compartments of everted sacs of rat and hamster ileum, a decrease in tissue ATP levels is observed.
DNA lesions induced in nuclei and nucleoli of monkey kidney cells in tissue culture by simian vacuolating virus (SV40)
Authors: Kasten Frederick H. , Vendrely Colette , Tournier Paul , Wicker René
Published: February 2005

Susceptible monkey kidney cultures were infected with SV40. DNA alterations were studied in stained preparations and by quantitative cytophotometry. Early changes included a decrease in mitotic rate. Later, enlarged DNA granules formed at the nuclear membrane, followed by massive production of refractile inclusion particles of DNA in the nuclear interior. This heavily stained mass often included separate, larger DNA viral bodies surrounded by halos. Also present within this mass was a hypertrophied nucleolus enveloped by an intense ring of DNA and a halo. Prominent DNA granules were observed within nucleoli. Strands of DNA passed between the mass of inclusion particles and the nucleolar‐associated DNA and nucleolus. Nuclei with inclusions contained increased DNA in well‐developed cases which was at least five times that found in normal cells. Two types of abnormal nuclei were observed, one of which was large, appeared early, and contained inclusions (Stage 1), while the other appeared later and was pyknotic (Stage 2). It is suggested that SV40 induces arrest of the cell cycle in the G2 phase which causes a decreased mitotic rate and a scarcity of infected nuclei in the euploid DNA class.
The effect of triton X‐100 on the permeability of erythrocytes to non‐electrolytes
Authors: Ospina Bertha , George Jaime , Hunter F. R.
Published: February 2005

Studies of the effect of triton X‐100 on the fragility of rabbit erythrocytes and on shape and volume changes of rabbit and sheep erythrocytes suspended in an isotonic salt solution suggest that this subtance alters the erythrocytes of other species in a manner similar to that reported previously for human red cells. Using a densimeter technique it was found that the permeability of relatively slowly moving non‐electrolyte‐carrier‐complexes is decreased by triton X‐100 but more rapidly penetrating systems are not affected by this substance. The permeability of some molecules which cross the membrane by diffusion is increased by triton X‐100. It is suggested that triton X‐100 affects both the aqueous channels and the portion of the membrane across which carriers move. Its action is less than that of tannic acid or butanol.
Seasonal changes in energy reserves in the common frog, Rana pipiens
Authors: Mizell Sherwin
Published: February 2005

Seasonal changes in blood glucose content, liver glycogen conten, and fat body weight have been studied in Rana pipiens. Over a 12‐month period frogs were maintained at room temperature in tap water for a minimum of 14 days before observations were made. The frogs were not fed while in the laboratory. Blood glucose content was high in the summer (June through August) and fall (September through August) and fall (September through November) and low in the winter (December through February) and spring (March through May). The value for summer (60 mgm per 100 cm3 blood) was not signficantly different from the blood glucose level in the fall (60 mgm %). However, the blood glucose content in the winter (52 mgm % ) and the spring (49 mgm % ) were significantly different from each other and from the summer and fall. Liver glycogen content was high in the fall (1.16 gm/100 gm body weight). This decreased through the winter (0.85 gm/100 gm body weight) and spring (0.50 gm/100gm body weigh) until the annual low was reached in the summer (0.27 gm/100 gm body weight). All seasons were significantly diferent from each other when tested statistically. Fat body weights also exhibited a seasonal variation. All seasons were significantly different from each other. The high was in the summer (203.3 mgm/100 gm body weight). Fat body weights then decreased to 87.1 mgm/100 body weight in the fall, 32.7 mgm/100 gm body weight in the winter, and 25.1 mgm/100 gm body weight in the spring. These data are important when studying metabolic changes in this common laboratory animal.
The spatial distribution of dividing and DNA‐synthesizing cells in mouse epithelium
Authors: Cameron Ivan L. , Gosslee David G. , Pilgrim Christoph
Published: February 2005

Cells of the germinal layer of mouse esophageal epithelium were used for quantitative assessment of the spatial distribution of proliferating cells. In tritiated thymidine autoradiographs the nonsynthesizing cells between synthesizing (or dividing) cells were counted, rather than counting the dividing cells in pre‐established grid units. Dividing and DNA‐synthesizing cells are almost random in spatial distribution, but there is an excess of labeled or dividing cells immediately adjacent to one another over what would be expected if the spatial distribution were random. Two possible explanations for the excess of adjacent proliferating cells are suggested: (a) direct cellular interaction or local humoral influences, and (b) phasing of adjacent cells which have a common line of descent.
Graph minors and linkages
Authors: Chen G. , Gould R. J. , Kawarabayashi K. , Pfender F. , Wei B.
Published: February 2005

Bollobás and Thomason showed that every 22k‐connected graph is k‐linked. Their result used a dense graph minor. In this paper, we investigate the ties between small graph minors and linkages. In particular, we show that a 6‐connected graph with a K minor is 3‐linked. Further, we show that a 7‐connected graph with a K minor is (2,5)‐linked. Finally, we show that a graph of order n and size at least 7n−29 contains a K minor. © 2005 Wiley Periodicals, Inc. J Graph Theory 49: 75–91, 2005
Studies on lymphocytes IV. Further observations upon the hemopoietic effects of splenectomy in frogs
Authors: Jordan H. E. , Speidel C. C.
Published: February 2005

Total splenectomy in the frog means practically complete extirpation of the erythropoietic apparatus. Out of sixty‐four operations it was followed by:

Stimulation of erythropoiesis in the kidney (mesonephros), 35 to 46 per cent.

Stimulation of erythropoiesis in the fat‐bodies, 5 per cent; lymphocytopoiesis, 8 per cent.

Stimulation of erythropoiesis in the bone‐marrow, 11 per cent.

Formation of a new spleen, 8 per cent.

No perceptible erythropoletic stimulation, 24 per cent. The latter leads to a condition of anemia followed by death within about sixty days.

Partial splenectomy leads to spleen regeneration.

The life tenure of the frog erythrocyte is approximately 100 days.

Total splenectomy experiments indicate that the chief function of the spleen in the frog inheres largely in its lymphocyte content and in the transformation of lymphocytes into erythrocytes.
A mechanism for the coordination and regulation of ciliary movement as revealed by microdissection and cytological studies of ciliated cells of mollusks
Authors: Grave Caswell , Schmitt Francis O.
Published: February 2005

Systems of fiber‐like structures traverse ciliated cells and epithelia in a way to suggest conduction paths for stimuli for coordinating and regulating ciliary movement, and results of microdissection support such an interpretation.

Some fibers of the systems in epithelia of the gill terminate on the nuclear membrane, some between nuclei in the basal cytoplasm.

The observed double refringency of the fibrillar apparatus places it in the category of irritable and contractile substance.

Bipolar cells and nerve‐like fibers lie immediately below and parallel with ciliated epithelia of the gill, but direct connections of these fibers with the intracellular system, although suspected, was not demonstrated.

Ciliated epithelia of the gill are syncytial in character in the direction of the beat of cilia.

Interciliary structures occur in the cuticular portion of ciliated epithelia which are interpreted to function in taking up strains in the gelled cytoplasm caused by the beat of cilia.

Cilia occur in pairs in epithelia of the gill, and members of pairs are fused at their distal ends.

Each cilium, as seen in dark‐field illumination, pierces its basal body, and the fiber that is a continuation of the cilium divides immediately below the basal body into two; one diverging to the right, one to the left.

Each cilium is composed of many delicate fibrillae.
The influence of temperature on the rate of locomotion in Amoeba II. The rate of locomotion in Amoeba at different temperatures
Authors: Schwitalla Alphonse M.
Published: February 2005

In general, the changes of locomotor rate of Amoeba under the influence of temperature are similar to the effects of temperature in other biological processes.

The rate increases with rising and decreases with falling temperatures within a certain temperature range, this being, for the forms investigated, the interval between 6° and 23.5°C. In some individuals, however, these limits were found to be wider, extending from 2° to 26°. There is an average optimum at about 23.5°, beyond which an increase in temperature is followed by a decrease in rate. The immediate response of Amoeba to a change of temperature is variable, due, as was shown in a previous paper, to the fact that locomotor‐rate changes are rhythmic. The effect of a change of temperature is thus conditioned not only by the enviornmental factors, but also by the phases of the locomotor rhythm. This fact also makes it difficult to establish the exact quantitative relationship which exists between a change of temperature and the locomotor rate—an aspect which will be developed in a future paper.