bluuebunny/crossref_metadata_2025 huggingface dataset:
Lanthanide(III) Nitrobenzenesulfonates as New Nitration Catalysts: The Role of the Metal and of the Counterion in the Catalytic Efficiency
Authors: Parac‐Vogt Tatjana N. , Pachini Sophia , Nockemann Peter , Van Hecke Kristof , Van Meervelt Luc , Binnemans Koen
Published: November 2004

Lanthanide(III) complexes of p‐nitrobenzenesulfonic acid, Ln(p‐NBSA)3, m‐nitrobenzenesulfonic acid, Ln(m‐NBSA)3, and 2,4‐nitrobenzenesulfonic acid, Ln(2,4‐NBSA)3, were prepared, characterized and examined as catalyst for the nitration of benzene, toluene, xylenes, naphthalene, bromobenzene and chlorobenzene. The initial screening of the catalysts showed that lanthanum(III) complexes were more effective than the corresponding ytterbium(III) complexes, and that catalysts containing the bulky 2,4‐NBSA ligand were less effective than the catalyst containing p‐NBSA (nosylate) or m‐NBSA ligands. Examination of a series of Ln(p‐NBSA)3 and Ln(m‐NBSA)3 catalysts revealed that there is a clear correlation between the ionic radii of the lanthanide(III) ions and the yields of nitration, with the lighter lanthanides being more effective. The X‐ray single crystal structure of Yb(m‐NBSA)3·6H2O shows that two m‐NBSA ligands are directly bound to the metal centre while the third ligand is not located in the first coordination sphere, but it is hydrogen bonded to one of the water molecules which is coordinated to ytterbium(III). NMR studies suggest that this structure is preserved under the conditions used in the nitration reaction. The structure of Yb(m‐NBSA)3 is markedly different from the structure of the well‐known ytterbium(III) triflate catalyst. The coordination of the nitrobenzenesulfonate counterion to the lanthanide(III) ion suggests that steric effects might play an important role in determining the efficiency of these novel nitration catalysts. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)
Synthetic Circularized Analogues of Bovine Pancreatic Trypsin Inhibitor
Authors: Tulla‐Puche Judit , Getun Irina V. , Alsina Jordi , Albericio Fernando , Barany George
Published: November 2004

Two cyclic analogues of the protein bovine pancreatic trypsin inhibitor (BPTI), c‐[R]Smc and c‐Cys5[R]Abu, have been synthesized. For the first target, a semisynthetic approach featured a cyclization that took advantage of the constraint imposed by the three disulfides of the native protein. For the second target, an entirely unstructured 58‐residue thiolester, prepared by total synthesis with mild Fmoc chemistry and a side‐chain anchoring strategy, was cyclized by native chemical ligation. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)
Inter‐ and Intramolecular [2+2]‐Photocycloaddition of Tetronates − Stereoselectivity, Mechanism, Scope and Synthetic Applications
Authors: Kemmler Michael , Herdtweck Eberhardt , Bach Thorsten
Published: November 2004

[2+2]‐photocycloaddition reactions of various tetronates (3−8, 12, 16, 20, 37) have been examined. The tetronates were prepared from the corresponding tetronic acid by O‐alkylation with an alkyl bromide or with an alcohol (Mitsunobu protocol). If the photocycloaddition reaction (λ = 254 nm, solvent: diethyl ether or tert‐butyl alcohol) was carried out in an intramolecular fashion the tri‐ and tetracyclic products 21−23, 27−36 were obtained in good yields (52−75%) and with excellent simple diastereoselectivity. The reaction tolerates a high degree of substitution at both the tetronate and at the alkene double bond. High facial diastereoselectivities were observed if stereogenic centers were present in the alkene tether (e.g. 7a → 33) or if the alkenyl substituent was attached to the stereogenic C5 carbon atom of the tetronate irradiation precursor (e.g. 20 → 32). The reaction was also conducted in an intermolecular fashion. The methoxyethoxymethoxy (MEM) protecting group was suitable to protect the free tetronate hydroxy group. The photocycloaddition of tetronate 8 to cyclopentene was highly selective delivering the tricyclic products 39 in an 8:1 exo/endo ratio (59% yield). The products obtained from the intermolecular reaction underwent a de Mayo‐like ring expansion delivering oxepane‐diones 45−47 in good yields (74−84%). In mechanistic studies it was found that the formation of the photoproduct was supressed upon addition of piperylene. Furthermore, in the presence of acetone as a sensitizer the reaction could be conducted at λ = 300 nm. At this wavelength no conversion occurred under direct irradiation. These observations suggest the involvement of triplet intermediates in the reaction. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)
Sulfonic Acid Libraries Attained Through Opening of 2‐Sulfobenzoic Acid Anhydride
Authors: Robinson Richard I. , Stephens John C. , Worden Steve M. , Blake Alexander J. , Wilson Claire , Woodward Simon
Published: November 2004

2‐Sulfobenzoic acid anhydride opens cleanly with N‐Boc‐protected α‐amino alcohols to afford zwitterionic esters 1,2‐C6H4(SO3−)(CO2CH2CHR1NH3+) (R1 = H, alkyl), the species R1 = iPr is crystallographically characterised. Dehydration of these species affords zwitterionic oxazoline sulfonic acid derivatives 1,2‐C6H4(SO3−)(CA=NH+CHR1CH2OA) (CA and OA are bonded C−O) for R1 = iPr (X‐ray), iBu, tBu, CH2Ph. Reaction with water regenerates the zwitterionic esters while exposure to M(OAc)2 (M = Cu, Pd) leads to the formation of the crystallographically characterised complexes MIIL2 (L = anion of the iPr‐oxazolinesulfonic acid). Heating either the zwitterionic esters or oxazolines with R2NH2 [R2 = CH2Ph, CH2(1‐C10H7), R‐CH(Me)Ph] leads to SN2 attack at the oxazoline methylene group leading to the amido sulfonic acids 1,2‐C6H4(CONHCHRCH2NHR2)(SO3H) based on crystallographic studies on R1 = iPr, R2 = CH2(1‐C10H7). (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)
FLOX® Steam Reforming for PEM Fuel Cell Systems
Authors: Schmid H.‐P. , Wünning J. A.
Published: November 2004

Primary energy savings and CO2 reduction is one of the key motivations for the use of fuel cell systems in the energy sector. A benchmark of domestic cogeneration by PEMFC with existing large scale power production systems such as combined steam‐gas turbine cycle, clearly reveals that only fuel cell systems optimising overall energy efficiency (> 85%) and electrical efficiencies (> 35%) show significant primary energy savings, about 10%, compared with the best competing technology.

In this context, fuel processing technology plays a dominant role. A comparison of autothermal and steam reforming concepts in a PEMFC system shows inherent advantages in terms of efficiency at low complexity for the latter. The main reason for this is that steam reforming allows for the straightforward and effective use of the anode‐off gas energy in the reformer burner. Consequently, practical electrical system efficiencies over 40% seem to be achievable, most likely by steam reformers.

FLOX®‐steam reforming technology has reached a high state of maturity, offering diverse advantages including: compact design, stable anode off‐gas usage, high efficiency, as well as simple control behaviour. Scaling of the concept is straightforward and offers an opportunity for efficient adaptation to smaller (1 kW) and larger (50 kW) units.
PEM – Fuel Cell System for Residential Applications
Authors: Britz P. , Zartenar N.
Published: November 2004

Viessmann is developing a PEM fuel cell system for residential applications. The uncharged PEM fuel cell system has a 2 kW electrical and 3 kW thermal power output. The Viessmann Fuel Processor is characterized by a steam‐reformer/burner combination in which the burner supplies the required heat to the steam reformer unit and the burner exhaust gas is used to heat water. Natural gas is used as fuel, which is fed into the reforming reactor after passing an integrated desulphurisation unit. The low temperature (600 °C) fuel processor is designed on the basis of steam reforming technology. For carbon monoxide removal, a single shift reactor and selective methanisation is used with noble metal catalysts on monoliths. In the shift reactor, carbon monoxide is converted into hydrogen by the water gas shift reaction. The low level of carbon monoxide at the outlet of the shift reactor is further reduced, to approximately 20 ppm, downstream in the methanisation reactor, to meet PEM fuel cell requirements. Since both catalysts work at the same temperature (240 °C), there is no requirement for an additional heat exchanger in the fuel processor. Start up time is less than 30 min.

In addition, Viessmann has developed a 2 kW class PEFC stack, without humidification. Reformate and dry air are fed straight to the stack. Due to the dry operation, water produced by the cell reaction rapidly diffuses through the electrolyte membrane. This was achieved by optimising the MEA, the gas flow pattern and the operating conditions. The cathode is operated by an air blower.
Selective reduction of fibrotic markers in repairing corneas of mice deficient in Smad3
Authors: Stramer Brian M. , Austin Jeffrey S. , Roberts Anita B. , Elizabeth Fini M.
Published: November 2004

The cytokine transforming growth factor‐β (TGF‐β) is a key mediator of fibrosis in all organs. Expression of fibrotic markers in repairing cutaneous wounds is reduced in mice lacking Smad3, a downstream cytoplasmic mediator of TGF‐β signaling (Ashcroft et al., 1999, Nat Cell Biol 1(5):260–266). This is correlated with a reduction in inflammation, and thus in the blood elements thought to be a significant source of TGF‐β at the wound site, the principle form being TGF‐β1. Since the major cellular source of TGF‐β in corneal wounds is the epithelium, and the principal isoform is TGF‐β2, we investigated whether Smad3 deficiency has similar anti‐fibrotic effects on corneal repair. In contrast to the situation of cutaneous repair, expression of the fibrotic marker, fibronectin, was equivalent in corneal repair tissue of Smad3−/− mice as compared to their +/− littermates, even though expression of a second fibrotic marker not previously examined in cutaneous wounds, α‐smooth muscle (sm) actin, was reduced. Also unlike in cutaneous wounds, the inflammatory response was unaffected. These differences between corneal and cutaneous repair correlated with the lack of apparent change in the levels of corneal TGF‐β2. There was a significant reduction of α‐sm actin expression in stromal cell cultures established from Smad3−/− mice as compared to their +/− littermates, but the rate of cell proliferation stimulated by TGF‐β, as well as expression of fibronectin, was unaffected. Therefore, a deficiency in Smad3 has different effects on corneal and cutaneous repair, probably due to the difference in cellular source and principal isoform of the TGF‐β involved. © 2004 Wiley‐Liss, Inc.
The role of caldesmon in the regulation of endothelial cytoskeleton and migration
Authors: Mirzapoiazova Tamara , Kolosova Irina A. , Romer Lew , Garcia Joe G.N. , Verin Alexander D.
Published: November 2004

The actin‐ and myosin‐binding protein, caldesmon (CaD) is an essential component of the cytoskeleton in smooth muscle and non‐muscle cells and is involved in the regulation of cell contractility, division, and assembly of actin filaments. CaD is abundantly present in endothelial cells (EC); however, the contribution of CaD in endothelial cytoskeletal arrangement is unclear. To examine this contribution, we generated expression constructs of l‐CaD cloned from bovine endothelium. Wild‐type CaD (WT‐CaD) and truncated mutants lacking either the N‐terminal myosin‐binding site or the C‐terminal domain 4b (containing actin‐ and calmodulin‐binding sites) were transfected into human pulmonary artery EC. Cell fractionation experiments and an actin overlay assay demonstrated that deleting domain 4b, but not the N‐terminal myosin‐binding site, resulted in decreased affinity to both the detergent‐insoluble cytoskeleton and soluble actin. Recombinant WT‐CaD co‐localized with acto‐myosin filaments in vivo, but neither of CaD mutants did. Thus both domain 4b and the myosin‐binding site are essential for proper localization of CaD in EC. Overexpression of WT‐CaD led to cell rounding and formation of a thick peripheral subcortical actin rim in quiescent EC, which correlated with decreased cellular migration. Pharmacological inhibition of p38 MAPK, but not ERK MAPK, caused disassembly of this peripheral actin rim in CaD‐transfected cells and decreased CaD phosphorylation at Ser531 (Ser789 in human h‐CaD). These results suggest that CaD is critically involved in the regulation of the actin cytoskeleton and migration in EC, and that p38 MAPK‐mediated CaD phosphorylation may be involved in endothelial cytoskeletal remodeling. © 2004 Wiley‐Liss, Inc.
HSG cells differentiated by culture on extracellular matrix involves induction of S‐adenosylmethione decarboxylase and ornithine decarboxylase
Authors: Lam Kirby , Zhang Lianfeng , Bewick Mary , Lafrenie Robert M.
Published: November 2004

The human salivary gland (HSG) epithelial cell line can differentiate when cultured on extracellular matrix preparations. We previously identified >30 genes upregulated by adhesion of HSG cells to extracellular matrix. In the current studies, we examined the role of one of these genes, the polyamine pathway biosynthetic enzyme S‐adenosylmethionine decarboxylase (SAM‐DC) and the related enzyme, ornithine decarboxylase (ODC), on HSG cell differentiation during culture on extracellular matrix. HSG cells cultured on fibronectin‐, collagen I gel‐, and Matrigel‐coated substrates for 12–24 h upregulated SAM‐DC and ODC mRNA expression and enzyme activity compared to cells cultured on non‐precoated substrates. After 3–5 days, HSG cells grown on Matrigel‐ or collagen I gel‐coated substrates acquired a differentiated phenotype: the cells showed changes in culture morphology and increased expression of salivary gland differentiation markers (vimentin, SN‐cystatin, and α‐amylase). Further, culturing the cells on substrates precoated with an anti‐β1‐integrin‐antibody promoted differentiation‐like changes. HSG cells cultured on collagen I‐ or Matrigel‐coated substrates rapidly entered the cell cycle but showed decreased cell proliferation at longer times. In contrast, cell proliferation was enhanced on fibronectin‐coated substrates compared to cells on non‐precoated substrates. Treatment with the polyamine synthesis inhibitors, difluoromethylornithine (DFMO), and methylglyoxal bis‐(guanylhydrazone) (MGBG), inhibited cell proliferation and delayed 3H‐thymidine incorporation in HSG cells cultured on all of the substrates. Further, inclusion of DFMO and MGBG inhibited or delayed acquisition of the differentiated phenotype in HSG cells cultured on Matrigel‐ or collagen I gel‐coated substrates. This suggests that the adhesion‐dependent expression of SAM‐DC and ODC contributes to extracellular matrix‐dependent HSG cell differentiation. © 2004 Wiley‐Liss, Inc.
An efficient gene transfer method mediated by ultrasound and microbubbles into the kidney
Authors: Koike Hiromi , Tomita Naruya , Azuma Haruhito , Taniyama Yoshiaki , Yamasaki Keita , Kunugiza Yasuo , Tachibana Katsuro , Ogihara Toshio , Morishita Ryuichi
Published: November 2004

Background

Safety issues are of paramount importance in clinical human gene therapy. From this point of view, it would be better to develop a novel non‐viral efficient gene transfer method. Recently, it was reported that ultrasound exposure could induce cell membrane permeabilization and enhance gene expression.

Methods

In this study, we examined the potential of ultrasound for gene transfer into the kidney. First, we transfected rat left kidney with luciferase plasmid mixed with microbubbles, Optison, to optimize the conditions (duration of ultrasound and concentration of Optison). Then, 4, 7, 14 and 21 days after gene transfer, luciferase activity was measured. Next, localization of gene expression was assessed by measuring luciferase activity and green fluorescent protein (GFP) expression. Expression of GFP plasmid was examined under a fluorescence microscope at 4 and 14 days after gene transfer. Finally, to examine the side effects of this gene transfer method, biochemical assays for aspartate aminotransferase (AST), alanine aminotransferase (ALT), blood urea nitrogen (BUN) and creatinine (Cre) were performed.

Results

Optison and/or ultrasound significantly enhanced the efficiency of gene transfer and expression in the kidney. Especially, 70–80% of total glomeruli could be transfected. Also, a significant dose‐dependent effect of Optison was observed as assessed by luciferase assay (Optison 25%: 12.5 × 105 relative light units (RLU)/g tissue; 50%: 31.3 × 105 RLU/g tissue; 100%: 57.9 × 105 RLU/g tissue). GFP expression could be observed in glomeruli, tubules and interstitial area. Results of blood tests did not change significantly after gene transfer.

Conclusions

Overall, an ultrasound‐mediated gene transfer method with Optison enhanced the efficiency of gene transfer and expression in the rat kidney. This novel non‐viral method may be useful for gene therapy for renal disease. Copyright © 2004 John Wiley & Sons, Ltd.
Chronic nicotine and smoke treatment modulate dopaminergic activities in ventral tegmental area and nucleus accumbens and the γ‐aminobutyric acid type B receptor expression of the rat prefrontal cortex
Authors: Li Shu‐Peng , Park Moon Seok , Kim Jong Hun , Kim Myeong Ok
Published: November 2004

Dopaminergic afferents from the mesencephalic areas, such as ventral tegmental area (VTA), synapse with the γ‐aminobutyric acid (GABA)‐ergic interneurons in the prefrontal cortex (PFC). Pharmacological and electrophysiological data show that the reinforcement, the dependence‐producing properties, as well as the psychopharmacologic effects of nicotine depend to a great extent on activation of nicotinic receptors within the mesolimbocortical dopaminergic projection. To explore further the relationship between the mesencephalic dopaminergic neurons and PFC GABAergic neurons, we investigated the effects of nicotine and passive exposure to cigarette smoke on the regulation of tyrosine hydroxylase (TH) in VTA and substantia nigra (SNC) and dopamine (DA) D1 receptor levels in nucleus accumbens (NAc) and caudate‐putamen (CPu). Also, the simultaneous changes in GABAB receptors mRNAs in the PFC were studied. The results showed that chronic nicotine and smoking treatment differentially changed the levels of TH protein in VTA and SNC and DA D1 receptor levels in Nac and CPu. GABAB1 and GABAB2 receptor mRNA levels also showed different change patterns. Ten and thirty minutes of smoke exposure increased GABAB1 receptor mRNA to a greater extent than that of GABAB2, whereas GABAB2 was greatly enhanced after 1 hr of smoke exposure. The TH levels in VTA were closely related to DA D1 receptor levels in NAc and with GABAB receptor mRNA changes in PFC. These results suggest that the mesolimbic pathway and GABAB receptor mRNA in PFC are modulated by nicotine and cigarette smoke, implying an important role in nicotine's psychopharmacological effects. © 2004 Wiley‐Liss, Inc.
In vivo optical imaging of tone‐evoked activity in the dorsal cochlear nucleus with a voltage sensitive dye
Authors: Kaltenbach J.A. , Zhang J.S.
Published: November 2004

We investigated the use of optical imaging for observing the spatial patterns of neural activation in the dorsal cochlear nucleus (DCN) of hamsters during tonal stimulation. The patterns of activation were studied in the DCN, in vivo, following application of a voltage sensitive dye, Di‐2‐ANEPEQ, to the DCN surface. Beginning 60–90 min following dye application, tones were presented to the ipsilateral ear. Electrophysiological recordings after dye application revealed no significant toxicity of Di‐2‐ANEPEQ that affected the frequency‐tuning properties of DCN neurons. We examined areas of activation in response to each of a series of test stimuli consisting of pure tones ranging in frequency from 2 to 20 kHz. For each stimulus condition, images were collected over a stimulus interval of 400 msec and averaged over 32 stimulus repetitions. These images revealed areas of activation with definable epicenters. The epicenters shifted from lateral to more medial locations on the DCN surface with increases in stimulus frequency. Comparison with electrophysiological data indicated a close parallel between the tonotopic gradient defined by optical imaging and that defined by the distribution of characteristic frequencies. The principal temporal and spatial features of these optical responses are described. © 2004 Wiley‐Liss, Inc.
Climate dynamics of atmosphere and ocean in the equatorial zone: a synthesis
Authors: Hastenrath Stefan , Lamb Peter J.
Published: November 2004

A synopsis is offered of circulation mechanisms in the oceanic regions of the equatorial zone. Over the eastern Atlantic and Pacific, and especially in boreal summer, cross‐equatorial flow from the Southern Hemisphere is strong and induces a tongue of cold surface waters, centred to the south of the equator. Upon crossing the equator in these sectors, owing to the Coriolis effect and a kinetic energy imbalance, the airstream speeds up and divergence develops, producing the Intertropical Divergence Zone (ITDZ). Once these processes result in the wind recurving from southeasterly to southwesterly, the flow slows down and becomes convergent, manifest in the Intertropical Convergence Zone, with a maximum to the south of the wind confluence. By contrast, over the western Atlantic and central Pacific and especially in boreal winter, winds in the equatorial band are predominantly from the east, upper‐ocean Ekman transport is directed away from the equator, and the upwelling and cold tongue are centred on the equator. Cross‐equatorial flow is insufficient to produce recurvature, the ITDZ is narrower and weaker, the divergence maximum is at the equator rather than in low northern latitudes, and the convergence maximum straddles the wind confluence.

Over the Indian Ocean, the wind field is dominated by the alternation between the predominantly meridional flow of the winter and summer monsoons. Equatorial westerlies are limited to the short monsoon transition seasons. Essential for their origin is an eastward pressure gradient along the equator and weak southern trade winds, allowing recurvature somewhat south of the equator. Because the zonal pressure gradient is strongest in boreal summer and the southern trade winds are weakest in austral summer, the equatorial westerlies peak in spring and autumn. The boreal autumn equatorial westerlies are the surface manifestation of a powerful zonal–vertical circulation cell along the Indian Ocean equator. Equatorial zonal–vertical circulation cells require well‐developed zonal flow in the lower troposphere along the equator and, therefore, appear confined to the oceanic longitudes and certain seasons. Thus, they are found over the Atlantic only in boreal winter and over the Indian Ocean only in boreal autumn, whereas over the Pacific they prevail all year round. Copyright © 2004 Royal Meteorological Society
Expression of growth differentiation factor 9 (GDF9), bone morphogenetic protein 15 (BMP15), and BMP receptors in the ovaries of goats
Authors: Silva J.R.V. , van den Hurk R. , van Tol H.T.A. , Roelen B.A.J. , Figueiredo J.R.
Published: November 2004

The process of ovarian folliculogenesis is composed of proliferation and differentiation of the constitutive cells in developing follicles. In goats, relatively little information is available on the local factors that regulate this process. We studied the presence and distribution of growth differentiation factor 9 (GDF9), bone morphogenetic protein 15 (BMP15), and BMP receptors types 2 (BMPR2), 1A (BMPR1A), and 1B (BMPR1B) in goat ovaries to find evidence for their possible roles in folliculogenesis. Ovaries of cyclic goats were collected and fixed in paraformaldehyde for immunohistochemical localization of GDF9 and BMP15 proteins or used to collect follicles and luteal tissue to study the mRNA expression of GDF9, BMP15, and BMP receptors using reverse transcriptase polymerase chain reaction (RT‐PCR). GDF9 and BMP15 proteins were found in oocytes of all types of follicles and granulosa cells of primary, secondary, and antral but not primordial follicles. The mRNAs for GDF9, BMP15, BMPR2, BMPR1A, and BMPR1B were detected in primordial, primary, and secondary follicles as well as in oocyte and granulosa cells of antral follicles. Transcripts for BMPR2, BMPR1A, BMPR1B, and GDF9, and GDF9 protein were furthermore found in corpora lutea. It is concluded that the mRNAs and proteins of GDF9 and BMP15 and the mRNAs of BMP receptors are expressed in goat ovarian follicles at all stages of their development, and that they form a complex intrafollicular regulatory system during folliculogenesis. Expression of all BMP receptor mRNAs and GDF9 mRNA and protein in luteal tissue additionally points to a role of GDF9 in corpus luteum function. Mol. Reprod. Dev. 70: 11–19, 2004. © 2004 Wiley‐Liss, Inc.
Mouse epiblasts change responsiveness to BMP4 signal required for PGC formation through functions of extraembryonic ectoderm
Authors: Okamura Daiji , Hayashi Katsuhiko , Matsui Yasuhisa
Published: November 2004

Mouse primordial germ cells (PGCs) are initially identified as a cluster of alkaline phosphatase (AP)‐positive cells within the extraembryonic mesoderm near the posterior part of the primitive streak at embryonic day (E) 7.25. Clonal analysis of epiblast cells has revealed that the putative precursors of PGCs are localized in the proximal epiblast, and we demonstrated that the conditions required for PGC formation are induced in the proximal region of epiblasts by extraembryonic ectoderm. Bone morphogenetic protein (BMP) 4 and BMP8b, which belong to the transforming growth factor‐β (TGF‐β) superfamily, might generate induction signals from extraembryonic ectoderm. Smad1 and Smad5, which are intracellular signaling molecules for BMP4, might also play a critical role in stimulating epiblasts to form PGC. However, how pluripotential epiblasts temporally and spatially respond to BMP signals to form PGCs remains unclear. The present study examines changes of responsiveness to BMP4 for PGC formation in epiblasts and their molecular mechanisms. We initially examined the effect of recombinant human (rh) BMP4 upon cultured epiblasts at different developmental stages, and found that they acquire the ability to respond to BMP4 signals for PGC formation between E5.25 and E5.5. In addition, such competence was conferred upon epiblasts by the extraembryonic ectoderm. We also showed that the increased expression of Smad1 and the onset of Smad5 expression induced by extraembryonic ectoderm might be responsible for quick acquisition of this competence. Furthermore, we show that only proximal epiblast cells maintain responsiveness to BMP4 for PGC formation at E6.0, and that this is associated with the proximal epiblast‐specific expression of Smad5. These results explain why only the proximal region of epiblasts can sustain the ability to form PGCs. Mol. Reprod. Dev. 70: 20–29, 2004. © 2004 Wiley‐Liss, Inc.
Oxygen‐regulated expression of GLUT‐1, GLUT‐3, and VEGF in the mouse blastocyst
Authors: Kind Karen L. , Collett Rachael A. , Harvey Alexandra J. , Thompson Jeremy G.
Published: November 2004

The oxygen concentration used in the incubation atmosphere during embryo culture influences embryo development rates and embryo quality. In somatic cells, oxygen levels can influence the expression of a range of genes, including glucose transporters, glycolytic enzymes, and angiogenic growth factors. Many of these oxygen‐regulated genes have important roles in embryonic development and metabolism. The aim of this study was to determine whether oxygen regulates gene expression in the preimplantation mouse blastocyst. Mouse embryos were cultured from the 1‐cell to morula stage under 7% oxygen, followed by culture under 20, 7, or 2% oxygen to the blastocyst stage. Expression of glucose transporter (GLUT)‐1, GLUT‐3, and vascular endothelial growth factor (VEGF) in blastocysts was measured by real‐time reverse transcription PCR. Development from morula to blastocyst was not altered by culture under different oxygen conditions. Expression of GLUT‐1, GLUT‐3, and vascular endothelial growth (VEGF) was increased by 2‐ to 4‐fold in embryos cultured under 2% oxygen, when compared to embryos cultured under 20 or 7% oxygen, and when compared to embryos developed in vivo (all P < 0.001). These results suggest that the preimplantation mouse embryo has the capacity to detect and respond to low oxygen availability with changes in expression of oxygen‐regulated genes. Mol. Reprod. Dev. 70: 37–44, 2004. © 2004 Wiley‐Liss, Inc.
TESSP‐1: A novel serine protease gene expressed in the spermatogonia and spermatocytes of adult mouse testes
Authors: Takano Naoharu , Matsui Hitoshi , Takahashi Takayuki
Published: November 2004

A cDNA encoding a novel type of serine protease, designated testis‐specific serine protease 1 (TESSP‐1), was cloned using mRNA isolated from the adult mouse testis. The open reading frame of this cDNA codes for a protein of 322 amino acids, which includes a hydrophobic signal peptide of 18 amino acids and an N‐terminal activation peptide of 34 amino acids. The protein has an additional hydrophobic amino acid sequence at the C‐terminus. Expression of the TESSP‐1 gene was restricted to the testis. TESSP‐1 mRNA expression initiated in the mouse testis at 2 weeks after birth, and its level increased steadily with sexual maturation of the animal. In situ hybridization analysis revealed that TESSP‐1 mRNA was expressed in type B spermatogonia and spermatocytes at stages between preleptotene and pachytene. The testis contained at least five distinct forms of TESSP‐1 transcript, which presumably resulted from alternative splicing of the mRNA, but only one of these transcripts encodes a complete, functional enzyme. Expression experiments using COS‐7 cells showed that TESSP‐1 was synthesized as a glycoprotein with N‐glycosylated carbohydrates. Tests also showed that the C‐terminal hydrophobic region of TESSP‐1 was important upon its binding to the membrane by anchoring through glycosylphosphatidylinositol (GPI). Mol. Reprod. Dev. 70: 1–10, 2004. © 2004 Wiley‐Liss, Inc.
Detection and expression of hepatitis B virus X gene in one and two‐cell embryos from golden hamster oocytes in vitro fertilized with human spermatozoa carrying HBV DNA
Authors: Ali Bahy‐Ahmed , Huang Tian‐Hua , Xie Qing‐Dong
Published: November 2004

The main objectives of this study were to introduce motile human sperm carrying Hepatitis B virus (HBV) DNA to golden hamster oocytes in a co‐culture environment and to detect the replication and expression of the HBx gene in early embryonic cells. Zona‐free hamster oocytes were inseminated with human sperm carrying pBR322‐HBV DNA plasmid using the in vitro fertilization (IVF) technique. Both the one‐ and two‐cell stages of early embryonic development were studied. PCR, RT‐PCR, and Dot hybridization were performed to observe the HBx gene and its expression in these stages. “Fluorescence in situ hybridization” (FISH) was carried out to confirm the integration of HBV into the pronucleus, nucleus, and the chromosomes of embryos. The results showed that we have the ability to obtain a fertilization rate of 80%. RT‐PCR showed that the HBx gene could be expressed in both one‐ and two‐cell stages of embryonic development. The data suggested the possibility of sperm as a vector for the vertical transmission of HBV DNA to the next generation. Mol. Reprod. Dev. 70: 30–36, 2004. © 2004 Wiley‐Liss, Inc.
Morphological abnormalities in the spermatozoa of fertile and infertile men
Authors: Kubo‐Irie Miyoko , Matsumiya Kiyomi , Iwamoto Teruaki , Kaneko Satoru , Ishijima Sumio
Published: November 2004

The morphological analysis of the spermatozoa from fertile and infertile men was performed using light and electron microscopy to clarify the relationship between sperm morphology and fertility. Semen samples obtained from 22 partners of pregnant women were prepared according to the protocol standardized in an international collaborative study. Semen samples from 17 patients with asthenozoospermia or varicocele were collected in a hospital. Abnormalities in the spermatozoa were classified into three types for the tails, two for the midpieces, and six for the heads according to the criteria adapted from WHO guidelines (World Health Organization, 1999: WHO laboratory manual for the examination of human semen and semen–cervical mucus interaction (4th edition)). Approximately 14% of the spermatozoa from the fertile men had abnormal tails at the light microscopic level while approximately 44% had abnormal heads. Most types of abnormalities found in the spermatozoa from the asthenozoospermic and varicocele patients were encountered in those from the fertile men, although the semen from the fertile men contained a higher percentage of normal spermatozoa than that from the patients. These results were also confirmed at the ultrastructural level. Most abnormal cell types are encountered in semen from fertile men, although the incidence of abnormalities is low. Mol. Reprod. Dev. 70: 70–81, 2004. © 2004 Wiley‐Liss, Inc.
Implications of structural genomics target selection strategies: Pfam5000, whole genome, and random approaches
Authors: Chandonia John‐Marc , Brenner Steven E.
Published: November 2004

Structural genomics is an international effort to determine the three‐dimensional shapes of all important biological macromolecules, with a primary focus on proteins. Target proteins should be selected according to a strategy that is medically and biologically relevant, of good value, and tractable. As an option to consider, we present the “Pfam5000” strategy, which involves selecting the 5000 most important families from the Pfam database as sources for targets. We compare the Pfam5000 strategy to several other proposed strategies that would require similar numbers of targets. These strategies include complete solution of several small to moderately sized bacterial proteomes, partial coverage of the human proteome, and random selection of approximately 5000 targets from sequenced genomes. We measure the impact that successful implementation of these strategies would have upon structural interpretation of the proteins in Swiss‐Prot, TrEMBL, and 131 complete proteomes (including 10 of eukaryotes) from the Proteome Analysis database at the European Bioinformatics Institute (EBI). Solving the structures of proteins from the 5000 largest Pfam families would allow accurate fold assignment for approximately 68% of all prokaryotic proteins (covering 59% of residues) and 61% of eukaryotic proteins (40% of residues). More fine‐grained coverage that would allow accurate modeling of these proteins would require an order of magnitude more targets. The Pfam5000 strategy may be modified in several ways, for example, to focus on larger families, bacterial sequences, or eukaryotic sequences; as long as secondary consideration is given to large families within Pfam, coverage results vary only slightly. In contrast, focusing structural genomics on a single tractable genome would have only a limited impact in structural knowledge of other proteomes: A significant fraction (about 30–40% of the proteins and 40–60% of the residues) of each proteome is classified in small families, which may have little overlap with other species of interest. Random selection of targets from one or more genomes is similar to the Pfam5000 strategy in that proteins from larger families are more likely to be chosen, but substantial effort would be spent on small families. Proteins 2005. © 2004 Wiley‐Liss, Inc.
Associative mechanism for phosphoryl transfer: A molecular dynamics simulation of Escherichia coli adenylate kinase complexed with its substrates
Authors: Krishnamurthy Harini , Lou Hongfeng , Kimple Adam , Vieille Claire , Cukier Robert I.
Published: November 2004

The ternary complex of Escherichia coli adenylate kinase (ECAK) with its substrates adenosine monophosphate (AMP) and Mg‐ATP, which catalyzes the reversible transfer of a phosphoryl group between adenosine triphosphate (ATP) and AMP, was studied using molecular dynamics. The starting structure for the simulation was assembled from the crystal structures of ECAK complexed with the bisubstrate analog diadenosine pentaphosphate (AP5A) and of Bacillus stearothermophilus adenylate kinase complexed with AP5A, Mg2+, and 4 coordinated water molecules, and by deleting 1 phosphate group from AP5A. The interactions of ECAK residues with the various moieties of ATP and AMP were compared to those inferred from NMR, X‐ray crystallography, site‐directed mutagenesis, and enzyme kinetic studies. The simulation supports the hypothesis that hydrogen bonds between AMP's adenine and the protein are at the origin of the high nucleoside monophosphate (NMP) specificity of AK. The ATP adenine and ribose moieties are only loosely bound to the protein, while the ATP phosphates are strongly bound to surrounding residues. The coordination sphere of Mg2+, consisting of 4 waters and oxygens of the ATP β‐ and γ‐phosphates, stays approximately octahedral during the simulation. The important role of the conserved Lys13 in the P loop in stabilizing the active site by bridging the ATP and AMP phosphates is evident. The influence of Mg2+, of its coordination waters, and of surrounding charged residues in maintaining the geometry and distances of the AMP α‐phosphate and ATP β‐ and γ‐phosphates is sufficient to support an associative reaction mechanism for phosphoryl transfer. Proteins 2005. © 2004 Wiley‐Liss, Inc.
Photoluminescence of doped ZnS nanoparticles under hydrostatic pressure
Authors: Li G. H. , Su F. H. , Ma B. S. , Ding K. , Xu S. J. , Chen W.
Published: November 2004

The pressure dependence of the photoluminescence from ZnS:Mn2+, ZnS:Cu2+, and ZnS:Eu2+ nanoparticles were investigated under hydrostatic pressure up to 6 GPa at room temperature. Both the orange emission from the 4T1 – 6A1 transition of Mn2+ ions and the blue emission from the DA pair transition in the ZnS host were observed in the Mn‐doped samples. The measured pressure coefficients are –34.3(8) meV/GPa for the Mn‐related emission and –3(3) meV/GPa for the DA band, respectively. The emission corresponding to the 4f65d1 – 4f7 transition of Eu2+ ions and the emission related to the transition from the conduction band of ZnS to the t2 level of Cu2+ ions were observed in the Eu‐ and Cu‐doped samples, respectively. The pressure coefficient of the Eu‐related emission was found to be 24.1(5) meV/GPa, while that of the Cu‐related emission is 63.2(9) meV/GPa. The size dependence of the pressure coefficients for the Mn‐related emission was also investigated. The Mn emission shifts to lower energies with increasing pressure and the shift rate (the absolute value of the pressure coefficient) is larger in the ZnS:Mn2+ nanoparticles than in bulk. Moreover, the absolute pressure coefficient increases with the decrease of the particle size. The pressure coefficients calculated based on the crystal field theory are in agreement with the experimental results. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
High‐pressure X‐ray structural study of BeO and ZnO to 200 GPa
Authors: Mori Y. , Niiya N. , Ukegawa K. , Mizuno T. , Takarabe K. , Ruoff A. L.
Published: November 2004

We have carried out high‐pressure X‐ray structural studies of BeO and ZnO up to 200 GPa to find the phase transition of BeO from the wurzite to the NaCl structure and that of ZnO from the NaCl to the CsCl structure, which are expected theoretically. The phase transition of BeO occurred at 137 GPa, which is in good agreement with the theoretical value of 139 GPa. The wurzite phase persisted up to 175 GPa. The bulk modulus of BeO at zero pressure is determined to be 223 GPa by the Birch's equation. As previously reported, the ZnO sample transformed from the wurzite structure to the NaCl structure at 9.1 GPa. Extending the pressure range up to 202 GPa no phase transition to the CsCl structure occurred. The bulk modulus of the NaCl structure was determined to be 194 GPa. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Role of charge‐transfer effects in regioselectivity
Authors: Korchowiec Jacek
Published: November 2004

The energy‐partitioning scheme was used to study the regioselectivity problem. As a model system, Diels–Adler (DA) reaction was considered. It is shown that charge‐transfer (CT) energy is not responsible for experimentally observed trends in regioselectivity. However, it is the only contribution to the overall interaction energy that depends regularly on the type of substituents attached to reactant molecules. The main factors governing the orientation in DA reaction are deformation and Heitler–London energies. We have also demonstrated that the clear relationship between CT energy and the amount of charge transferred from one to another reactant exists for reactive systems that differ only in the substitution pattern. © 2004 Wiley Periodicals, Inc. Int J Quantum Chem, 2005
Density functional calculations of 19F and 235U NMR chemical shifts in uranium (VI) chloride fluorides UF6−nCln: Influence of the relativistic approximation and role of the exchange‐correlation functional
Authors: Schreckenbach Georg
Published: November 2004

Relativistic density functional theory (DFT) has been applied to the calculation of the 19F nuclear magnetic resonance (NMR) chemical shifts of the title compounds. It is shown that, while large‐core effective core potentials (ECP) fail completely for the calculation of ligand NMR chemical shifts in uranium compounds, small‐core ECPs are a valid relativistic method for this purpose. In an earlier study of the same systems, certain differences between theory and experiment had been observed, for instance, in the relative chemical shift of the A4 and X sites in UF5Cl. The reason for these deviations has been investigated further in the current paper. By comparing different relativistic methods, it is shown that the relativistic approximation is not responsible for these deviations. The role of the approximation to the exchange‐correlation (XC) functional of DFT has been probed, and generalized gradient approximations (GGA) as well as hybrid DFT methods have been investigated. None of these methods corrects the mentioned errors. It is argued that the neglect of environmental factors (solvent effects) remains as a possible error source, although the approximate XC functional appears to be the more likely cause of the problem. 235U NMR shieldings and chemical shifts have been calculated, and the trends predicted earlier have been confirmed. © 2004 Wiley Periodicals, Inc. Int J Quantum Chem, 2005
Building teacher identity with urban youth: Voices of beginning middle school science teachers in an alternative certification program
Authors: Proweller Amira , Mitchener Carole P.
Published: November 2004

Teacher identity development and change is shaped by the interrelationship between personal biography and experience and professional knowledge linked to the teaching environment, students, subject matter, and culture of the school. Working from this framework, this study examines how beginning teacher interns who are part of an alternative route to teacher certification construct a professional identity as science educators in response to the needs and interests of urban youth. From the teacher interns, we learn that crafting a professional identity as a middle‐level science teacher involves creating a culture around science instruction driven by imagining “what can be,” essentially a vision for a quality and inclusive science curriculum implicating science content, teaching methods, and relationships with their students. The study has important implications for the preparation of a stronger and more diverse teaching force able to provide effective and inclusive science education for all youth. It also suggests the need for greater attention to personal and professional experience and perceptions as critical to the development of a meaningful teacher practice in science. © 2004 Wiley Periodicals, Inc. J Res Sci Teach 41: 1044–1062, 2004
Environment, Quality of Life, and Urban Growth in the New Economy
Authors: Hirschhorn Joel S.
Published: November 2004

Sooner or later, most environmental professionals will be affected by the national smart growth movement, which addresses suburban sprawl and urban revitalization. Environmental sustainability is at the heart of more sustainable economic growth—which means growth that does not sacrifice quality of life for economic prosperity. This article summarizes the findings of a recent report on the linkage between growth and quality of life in the new economy, with a special emphasis on the role of governors. © 2001 John Wiley & Sons, Inc.
Integrating Economic Analysis into LCA
Authors: Norris Gregory A.
Published: November 2004

Current life‐cycle assessment (LCA) methodologies rarely include economic analysis—even though this element is almost always crucial to any company's decision making. This article discusses practical tools for integrating economic considerations into LCA. © 2001 John Wiley & Sons, Inc.
Eco‐Value, Sustainability, and Shareholder Value: Driving Environmental Performance to the Bottom Line
Authors: Kiernan Matthew J.
Published: November 2004

Contrary to popular assumptions, superior eco‐efficiency is associated with superior financial performance throughout a range of industries. In fact, environmental leaders typically outperform laggards by a substantial margin. © 2001 John Wiley & Sons, Inc.
Metal Products and Machinery: Proposed Rule for Pretreatment and Effluent Guidelines
Authors: Miller Wade
Published: November 2004

EPA's proposal outlines technology‐based effluent limits and pretreatment standards for waste‐water discharges from facilities that manufacture, rebuild, repair, or maintain finished metal products, parts, or machines. © 2001 John Wiley & Sons, Inc.
“Externes Denken“ beim Problemlösen - unterstützt das Skizzieren auch die Problemanalyse?
Authors: Sachse Pierre , Hacker Winfried , Leinert Sven
Published: November 2004

Zusammenfassung. Bei technischen Entwurfstätigkeiten ist die Aufgabenanalyse leistungsbestimmend. Auch Experten nutzen dabei u. a. Freihandskizzen. Die experimentelle Studie (N = 60 Studierende einer Technischen Universität) zeigt an Mechanikproblemen, dass Skizzieren während der Aufgabenanalyse das Identifizieren von Relationen, nicht von Komponenten der Systeme, ohne Verlängerung der Bearbeitungszeit verbessert. Die Ergebnisse können nicht allein durch Gedächtnisunterstützungen erklärt werden. Das Skizzieren unterstützt Denkprozesse. Es wird für die Wirksamkeit externer psychomotorischer Komponenten von Denkprozessen argumentiert. Praktische Konsequenzen werden angeführt.
Adolescent Suicide Myths in the United States
Authors: Moskos Michelle Ann , Achilles Jennifer , Gray Doug
Published: November 2004

Abstract: In the United States, teen suicide rates tripled over several decades, but have declined slightly since the mid-1990s. Suicide, by its nature, is a complex problem. Many myths have developed about individuals who complete suicide, suicide risk factors, current prevention programs, and the treatment of at-risk youth. The purpose of this article is to address these myths, to separate fact from fiction, and offer recommendations for future suicide prevention programs. Myth #1: Suicide attempters and completers are similar. Myth #2: Current prevention programs work. Myth #3: Teenagers have the highest suicide rate. Myth #4: Suicide is caused by family and social stress. Myth #5: Suicide is not inherited genetically. Myth #6: Teen suicide represents treatment failure. Psychiatric illnesses are often viewed differently from other medical problems. Research should precede any public health effort, so that suicide prevention programs can be designed, implemented, and evaluated appropriately. Too often suicide prevention programs do not use evidence-based research or practice methodologies. More funding is warranted to continue evidence-based studies. We propose that suicide be studied like any medical illness, and that future prevention efforts are evidence-based, with appropriate outcome measures.