bluuebunny/crossref_metadata_2025 huggingface dataset:
Histologic coagulative tumor necrosis as a prognostic indicator of renal cell carcinoma aggressiveness
Authors: Sengupta Shomik , Lohse Christine M. , Leibovich Bradley C. , Frank Igor , Thompson R. Houston , Webster W. Scott , Zincke Horst , Blute Michael L. , Cheville John C. , Kwon Eugene D.
Published: June 2005

BACKGROUND

Prognostic markers for renal cell carcinoma (RCC), such as patient symptoms, tumor stage, tumor size, and tumor grade, are useful for determining appropriate follow‐up and selecting patients for adjuvant therapy. Histologic coagulative tumor necrosis, also reported to be a prognostic marker for RCC, has not previously been extensively described or investigated. Hence, the objective of the current study was to characterize tumor necrosis as a prognostic feature of RCC.

METHODS

The authors of the current study identified 3009 patients treated surgically for RCC between 1970 and 2002 from the Mayo Clinic Nephrectomy Registry (Rochester, MN). Associations of tumor necrosis with clinical, laboratory, and pathologic features were examined with chi‐square, Fisher exact test, and Wilcoxon rank‐sum tests. Cancer‐specific survival was estimated with the Kaplan–Meier method, and associations with outcome were assessed with Cox proportional hazard models.

RESULTS

Tumor necrosis was present in 690 of 2445 (28%) clear cell, 196 of 421 (47%) papillary, and 28 of 143 (20%) chromophobe RCCs. The risk ratio for death from RCC in patients with necrotic compared with nonnecrotic tumors was 5.27 (95% confidence interval [CI]: 4.56–6.09; P < 0.001) for clear cell, 4.20 (CI: 1.65–10.68; P < 0.001) for chromophobe, and 1.49 (CI: 0.81–2.74; P = 0.199) for papillary RCC. The survival difference for clear cell RCC persisted even after multivariate adjustment for tumor stage, size, and grade (risk ratio 1.90; P < 0.001).

CONCLUSIONS

Histologic coagulative tumor necrosis is an independent predictor of outcome for clear cell and chromophobe RCC, and it should be routinely reported and used in clinical assessment. Cancer 2005. © 2005 American Cancer Society.
A population‐based study of lung carcinoma in Pennsylvania
Authors: Campling Barbara G. , Hwang Wei‐Ting , Zhang Jiameng , Thompson Stephanie , Litzky Leslie A. , Vachani Anil , Rosen Ilene M. , Algazy Kenneth M.
Published: June 2005

BACKGROUND

Lung carcinoma remains the major cause of cancer death in North America and is even more common among military veterans. The objective of this study was to determine whether there were differences in the characteristics and survival of Pennsylvania patients with lung carcinoma in the Veterans Administration (VA) hospital system compared with patients in the rest of the state.

METHODS

The Pennsylvania Cancer Registry was used to identify all patients who were diagnosed with lung carcinoma in the State of Pennsylvania from 1995 to 1999. Patients who were treated within the Veterans Administration Health Care Network were identified by hospital code. Survival from the date of diagnosis of lung carcinoma was determined by using the Pennsylvania state mortality files from 1995 to 2001.

RESULTS

From 1995 to 1999, 48,994 patients were newly diagnosed with lung carcinoma in Pennsylvania (41.2% women), including 856 patients in the VA system (6 women). The current analysis was restricted to male patients (n= 28,798 men). There was no major difference in age of VA patients compared with non‐VA patients, and the proportions of patients who had localized or regional stage disease were similar (49% of VA patients vs. 48% of non‐VA patients). The proportion of black patients was much higher in the VA population (23%) compared with the non‐VA population (9%). The median survival was 6.3 months for VA patients compared with 7.9 months for patients in the rest of the state, and the 5‐year overall survival rate was 12% for VA patients compared with 15% for patients in the rest of the state. When survival was analyzed according to race, there was a significant difference in the age‐adjusted survival of white patients in the VA system compared with patients in the rest of the state (P= 0.0007), but no significant difference was observed among black patients (P= 0.92).

CONCLUSIONS

The overall survival of VA patients with lung carcinoma in Pennsylvania was inferior to that of patients in the remainder of the state and this was due primarily to differences in survival among the white patients. Further investigation will be necessary to determine whether this disparity was caused by differences in socioeconomic status or comorbidities or whether there are systematic differences in the diagnosis, staging, or treatment of lung carcinoma between VA patients and civilian patients. Cancer 2005. © 2005 American Cancer Society.
Professional and economic factors affecting access to mammography: A crisis today, or tomorrow?
Authors: Farria Dione M. , Schmidt Maria E. , Monsees Barbara S. , Smith Robert A. , Hildebolt Charles , Yoffie Roberta , Monticciolo Debra L. , Feig Stephen A. , Bassett Lawrence W.
Published: June 2005

BACKGROUND

Objective data and anecdotal reports have suggested that access to mammography may be declining because of facility closures and difficulty in recruiting and retaining radiologists and radiologic technologists. To gain insight into the practice patterns, use of emerging technologies, and concerns of breast imagers in current practice, the Society of Breast Imaging (SBI) conducted a national survey of breast imaging practices in the U.S.

METHODS

Between October 2003 and April 2004, the SBI conducted a survey of the SBI membership database, and received completed surveys from 575 breast imaging practices in the U.S. Responses to the survey regarding practice characteristics, the utilization of standard and emerging technologies, staffing, malpractice, finance, and morale were analyzed.

RESULTS

Job vacancies for radiologists who read mammograms were reported in 163 practices (29%), 59 of which (10%) had 2 or more openings. A higher proportion of practices with job openings had long appointment waiting times for asymptomatic women when compared with fully staffed practices. Unfilled fellowship positions also were common, with 41 of 65 practices that offer fellowships reporting 47 openings. Among 554 responding practices, 55% reported that someone in their practice was sued because of a mammography related case within the past 5 years, and 50% of practices reported that the threat of lawsuits made radiologist staffing “moderately” or “a lot” more difficult. Of 521 responding practices, 35% reported financial losses in 2002. One in 5 respondents reported that they would prefer to spend less time in mammography, and fewer than 1 in 3 would recommend a breast imaging fellowship to a relative or friend. Emerging technologies, such as breast magnetic resonance imaging and screening ultrasound, currently are being performed in many practices.

CONCLUSIONS

The survey results provide support for anecdotal reports that breast imaging practices face significant challenges and stresses, including shortages of key personnel, a lack of trainees, malpractice concerns, financial constraints, increased workload due to emerging technologies, low appeal of breast imaging as a career specialty, and the steady rise in the population of women of screening age. Cancer 2005. © 2005 American Cancer Society.
Subcellular localization of the dopamine D2 receptor and coexistence with the calcium‐binding protein neuronal calcium sensor‐1 in the primate prefrontal cortex
Authors: Negyessy Laszlo , Goldman‐Rakic Patricia S.
Published: June 2005

Structures of the cerebral cortex expressing the D2 dopamine receptor subtype (D2) are important sites of action of antipsychotic drugs. It has also been repeatedly suggested that the prefrontal cortex plays a significant role in neuropsychiatric disorders, including schizophrenia. Here, by using single and double immunohistochemical techniques with electron microscopy, we investigated in the primate prefrontal cortex the ultrastructural localization of D2 and we compared it with that of the neuronal calcium sensor‐1 (NCS‐1), a neuron‐specific calcium‐binding and D2‐interacting protein. D2 immunoreactivity, revealed with preembedding immunoperoxidase in single labeling and with preembedding immunogold for double labeling, was localized in cell bodies with ultrastructural characteristics of both neurons and astroglia. D2 was localized in pre‐ and postsynaptic structures, including spines and dendrites, and in both excitatory‐ and inhibitory‐like axon terminals. Immunogold labeling revealed peri‐ and extrasynaptic localization of D2 in postsynaptic structures, whereas extrasynaptic labeling was typically found in boutons. NSC‐1 immunoreactivity was abundant in pre‐ and postsynaptic structures, in which it was also colocalized with D2. With the present strategy (that has high resolution but relatively limited sensitivity), NSC‐1 was observed in about 10% of the D2‐immunopositive spines and in a lower proportion of D2‐immunopositive dendrites and boutons. The data demonstrate the localization of D2 in pre‐ and postsynaptic as well as extra‐ and perisynaptic structures of the primate prefrontal cortex. The data also show the coexistence of NCS‐1 and D2 at the ultrastructural level. The latter finding suggests a role for NCS‐1 in desensitization of D2 in the prefrontal cortex. J. Comp. Neurol. 488:464–475, 2005. © 2005 Wiley‐Liss, Inc.
Development of neurons and fibers containing calcium binding proteins in the pallial amygdala of mouse, with special emphasis on those of the basolateral amygdalar complex
Authors: Legaz Isabel , Olmos Luis , Real M. Ángeles , Guirado Salvador , Dávila José Carlos , Medina Loreta
Published: June 2005

We studied the development of neurons and fibers containing calbindin, calretinin, and parvalbumin in the mouse pallial amygdala, with special emphasis on those of the basolateral amygdalar complex. Numerous calbindin‐immunoreactive (CB+) cells were observed in the incipient basolateral amygdalar complex and cortical amygdalar area from E13.5. At E16.5, CB+ cells became more abundant in the lateral and basolateral nuclei than in the basomedial nucleus, showing a pattern very similar to that of γ‐aminobutyric acid (GABA)ergic neurons. Many CB+ cells observed in the pallial amygdala appeared to originate in the anterior entopeduncular area/ganglionic eminences of the subpallium. The density of CB+ cells gradually increased in the pallial amygdala until the first postnatal week and appeared to decrease later, coinciding with the postnatal appearance of parvalbumin cells and raising the possibility of a partial phenotypic shift. Calretinin (CR) immunoreactivity could be observed in a few cells and fibers in the pallial amygdala at E14.5, and by E16.5 it became a good marker of the different nuclei of the basolateral amygdalar complex. Numerous CB+ and CR+ varicosities, part of which have an intrinsic origin, were observed in the basolateral amygdalar complex from E16.5, and some surrounded unstained perikarya and/or processes before birth, indicating an early formation of inhibitory networks. Each calcium binding protein showed a distinct spatiotemporal expression pattern of development in the mouse pallial amygdala. Any alteration in the development of neurons and fibers containing calcium binding proteins of the pallial amygdala may result in important disorders of emotional and social behavior. J. Comp. Neurol. 488:492–513, 2005. © 2005 Wiley‐Liss, Inc.
Cell tracking velocimetry as a tool for defining saturation binding of magnetically conjugated antibodies
Authors: Leigh Diane R. , Steinert Steffen , Moore Lee R. , Chalmers Jeffrey J. , Zborowski Maciej
Published: June 2005

Background:

Continuous flow immunomagnetic separation is an attractive alternative to current batch mode immunomagnetic separation methods because it is capable of high sorting speeds at mild cell conditions, and grants the operator better control of separation process. The control of the separation is dependent on knowledge of the amount of magnetic label attached to the cell (magnetic labeling intensity), however. Determination of the magnetic labeling is accomplished by measuring cell magnetophoretic mobility using a newly developed technique of Cell Tracking Velocimetry (CTV).

Methods:

Flow cytometry was used to define the antibody binding characteristics of a fluorescently tagged primary antibody. Subsequently, CTV was used to measure antibody‐binding characteristics of a magnetically tagged secondary antibody.

Results:

The results of this study show that CTV is capable of providing valuable information concerning the cell labeling by magnetically tagged antibodies. It was demonstrated that the magnetically conjugated antibody binding curve exhibits the same exponential increase to saturation characteristics as that seen with the fluorescently tagged antibody. Further, it was shown that the intensity of the secondary magnetic labeling is directly proportional to the intensity of the primary fluorescent label.

Conclusions:

CTV is an accurate tool for evaluation of magnetically conjugated antibodies. The ability to determine the intensity of magnetic labeling is necessary for the development of continuous flow immunomagnetic separations based on cell magnetophoresis. © 2005 Wiley‐Liss, Inc.
Comparative analysis of Six3 and Six6 distribution in the developing and adult mouse brain
Authors: Conte Ivan , Morcillo Julian , Bovolenta Paola
Published: June 2005

Six3 and Six6 genes are two closely related members of the Six/sine oculis family of homeobox containing transcription factors. Their expression and function at early stages of embryonic development has been widely addressed in a variety of species. However, their mRNA distribution during late embryonic, postnatal, and adult brain barely has been analyzed. Here, we show that despite their initial overlap in the anterior neural plate, the expression of Six3 and Six6 progressively segregates to different regions during mammalian brain development, maintaining only few areas of partial overlap in the thalamic and hypothalamic regions. Six3, but not Six6, is additionally expressed in the olfactory bulb, cerebral cortex, hippocampus, midbrain, and cerebellum. These distinct patterns support the idea that Six3 and Six6 are differentially required during forebrain development. Developmental Dynamics 234:718–725, 2005. © 2005 Wiley‐Liss, Inc.
Specification of embryonic axis and mosaic development in ascidians
Authors: Nishida Hiroki
Published: June 2005

Setting up future body axes is the first important event before and at the beginning of embryogenesis. The ascidian embryo is a classic model that has been used to gain insight into developmental processes for over a century. This review summarizes advances made in this decade in our understanding of the developmental processes involved in the specification of the embryonic axes and cell fates during early ascidian embryogenesis. Maternal factors, including mRNAs, are translocated to specific regions of the egg by cytoplasmic and cortical reorganization, so‐called ooplasmic segregation, and specify the animal–vegetal axis and the one perpendicular to it, which is defined as the anteroposterior axis in ascidians. Some postplasmic/PEM RNAs that are anchored to cortical endoplasmic reticulum are brought to the future posterior pole of fertilized eggs, and play crucial roles in posterior development. Following specification of the animal–vegetal axis, nuclear localization of β‐catenin takes place in the vegetal blastomeres; this occurrence is important for the acquisition of the vegetal character of the blastomeres in later development. Positioning of these maternal factors lead to subsequent cell interactions and zygotic gene expression responsible for axis establishment and for cell fate specification. We describe how endoderm blastomeres in the vegetal pole region emanate inductive signals mainly attributable to fibroblast growth factor. Marginal blastomeres next to endoderm blastomeres respond differently in ways that are determined by intrinsic competence factors. Expression patterns of developmentally important genes, including key transcription factors of each tissue type, are also summarized. Developmental Dynamics 233:1177–1193, 2005. © 2005 Wiley‐Liss, Inc.
Isolation and comparative expression analysis of the Myc‐regulatory proteins Mad1, Mad3, and Mnt during Xenopus development
Authors: Juergens Kathrin , Rust Barbara , Pieler Tomas , Henningfeld Kristine A.
Published: June 2005

The Myc‐Max‐Mad network of transcription factors plays an essential role in many cellular processes such as proliferation, differentiation, and apoptosis. The Mad proteins heterodimerize with Max, function as transcriptional repressors, and are capable of antagonizing the transforming activity of Myc. We report on the isolation of Xmad1, Xmad3, and Xmnt, novel Xenopus genes belonging to the Mad family. We also describe their temporal and spatial expression patterns during Xenopus embryogenesis. Xmad1 expression is found primarily in cells that have undergone terminal differentiation including the notochord, floor plate, and cement gland. Xmad3 transcripts are expressed broadly throughout the central nervous system and the eye, starting at neurula stages. In contrast, Xmnt expression in the CNS was localized anteriorly and, in addition, is present in the migrating neural crest cells. This study demonstrates the Mads are expressed in specific and mostly nonoverlapping patterns, suggesting distinct roles during embryogenesis. Developmental Dynamics 233:1554–1559, 2005. © 2005 Wiley‐Liss, Inc.
Nuclear β‐catenin promotes non‐neural ectoderm and posterior cell fates in amphioxus embryos
Authors: Holland Linda Z. , Panfilio Kristen A. , Chastain Roger , Schubert Michael , Holland Nicholas D.
Published: June 2005

In vertebrate development, Wnt/β‐catenin signaling has an early role in specification of dorsal/anterior identity and a late one in posterior specification. To understand the evolution of these roles, we cloned β‐catenin from the invertebrate chordate amphioxus. The exon/intron organization of β‐catenin is highly conserved between amphioxus and other animals including a cnidarian, but notDrosophila. In development, amphioxus β‐catenin is concentrated in all nuclei from the 16‐cell stage until the onset of gastrulation when it becomes undetectable in presumptive mesendoderm. Li+, which up‐regulates Wnt/β‐catenin signaling, had no detectable effect on axial patterning when applied before the late blastula stage, suggesting that a role for β‐catenin in specification of dorsal/anterior identity may be a vertebrate innovation. From the mid‐gastrula through the neurula stage, the highest levels of nuclear β‐catenin are around the blastopore. In the early neurula, β‐catenin is down‐regulated in the neural plate, but remains high in adjacent non‐neural ectoderm. Embryos treated with Li+at the late blastula stage are markedly posteriorized and lack a neural plate. These results suggest that in amphioxus, as in vertebrates, down‐regulation of Wnt/β‐catenin signaling in the neural plate is necessary for maintenance of the neuroectoderm and that a major evolutionarily conserved role of Wnt/β‐catenin signaling is to specify posterior identity and pattern the anterior/posterior axis. Developmental Dynamics 233:1430–1443, 2005. © 2005 Wiley‐Liss, Inc.
Identification of new netrin family members in zebrafish: Developmental expression of netrin2 and netrin4
Authors: Won Park Kye , Urness Lisa D. , Senchuk Megan M. , Colvin Carrie J. , Wythe Joshua D. , Chien Chi‐Bin , Li Dean Y.
Published: June 2005

Netrin1 is a diffusible factor that attracts commissural axons to the floor plate of the spinal cord. Recent evidence indicates that Netrin1 is widely expressed and functions in the development of multiple organ systems. In mammals, there are three genes encoding Netrins, whereas in zebrafish, only the Netrin1 orthologs netrin1a and netrin1b have been identified. Here, we have cloned two new zebrafish Netrins, netrin2 and netrin4, and present a comparative sequence and expression analysis. Despite significant sequence similarity with netrin1a/netrin1b, netrin2 displays a unique expression pattern. Netrin2 transcript is first detected in the notochord and in developing somites at early somitogenesis. By late somitogenesis, netrin2 is expressed in the fourth rhombomere and is subsequently expressed in the hindbrain and otic vesicles. In contrast, netrin4 is detected only at very low levels during early development. The nonoverlapping expression patterns of these four Netrins suggest that they may play unique roles in zebrafish development. Developmental Dynamics 234:726–731, 2005. © 2005 Wiley‐Liss, Inc.
Platelet‐derived growth factors in the developing avian heart and maturating coronary vasculature
Authors: Van Den Akker Nynke M.S. , Lie‐Venema Heleen , Maas Saskia , Eralp Ismail , DeRuiter Marco C. , Poelmann Robert E. , Gittenberger‐De Groot Adriana C.
Published: June 2005

Platelet‐derived growth factors (PDGFs) are important in embryonic development. To elucidate their role in avian heart and coronary development, we investigated protein expression patterns of PDGF‐A, PDGF‐B, and the receptors PDGFR‐α and PDGFR‐β using immunohistochemistry on sections of pro‐epicardial quail–chicken chimeras of Hamburger and Hamilton (HH) 28–HH35. PDGF‐A and PDGFR‐α were expressed in the atrial septum, sinus venosus, and throughout the myocardium, with PDGFR‐α retreating to the trabeculae at later stages. Additionally, PDGF‐A and PDGFR‐α were present in outflow tract cushion mesenchyme and myocardium, respectively. Small cardiac nerves and (sub)epicardial cells expressed PDGF‐B and PDGFR‐β. Furthermore, endothelial cells expressed PDGF‐B, while vascular smooth muscle cells and interstitial epicardium‐derived cells expressed PDGFR‐β, indicating a role in coronary maturation. PDGF‐B is also present in ventricular septal development, in the absence of any PDGFR. Epicardium‐derived cells in the atrioventricular cushions expressed PDGFR‐β. We conclude that all four proteins are involved in myocardial development, whereas PDGF‐B and PDGFR‐β are specifically important in coronary maturation. Developmental Dynamics 233:1579–1588, 2005. © 2005 Wiley‐Liss, Inc.
Wideband multi‐beam forming method using delayed array sensors and two‐dimensional digital filter
Authors: Nishikawa Kiyoshi
Published: June 2005

In this paper, a method is proposed for multi‐beam forming of wideband signals by means of delay processors and two‐dimensional fan filters. Only one axially symmetric two‐dimensional fan filter is used. Multi‐beam forming is carried out by multiplexing the delay processors for two‐dimensional signals for each beam direction. The delay processing here corresponds to a rotation of the two‐dimensional spectra in the two‐dimensional frequency domain and provides a delay proportional to the sensor location to each sensor output. Since each delay is a fractional delay, a method of digital signal processing based on high‐speed sampling and thinning is used for realization. A design method for multi‐beam forming is given and a study of expanding the receiving angle range is carried out. It is shown that excellent multi‐beam forming is possible if the method is used within an appropriate receiving signal range, although the beam width is slightly different depending on the beam direction. Finally, a difference of the method from multi‐beam forming by the use of several two‐dimensional fan filters is discussed. The positioning of this method and its effectiveness are clarified. © 2005 Wiley Periodicals, Inc. Electron Comm Jpn Pt 3, 88(12): 1–12, 2005; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecjc.20175
Luminescence and Theoretical Studies of Cu(tripod)X [tripod = 1,1,1‐Tris(diphenylphosphanylmethyl)ethane; X– = Halide, Thiophenolate, Phenylacetylide]
Authors: Pawlowski Valeri , Knör Günther , Lennartz Christian , Vogler Arnd
Published: June 2005

Complexes of the type CuI(tripod)X [tripod = 1,1,1‐tris(diphenylphosphanylmethyl)ethane; X– = Br–, I–, PhS–, PhC≡C–]are phosphorescent in solution and in the solid state (λmax ≈ 465 nm). Calculations show that the emissive triplet is of mixed MLCT/LLCT character. The emission is facilitated by the rigid tetrahedral structure, which is imposed by the tripod ligand. Accordingly, a distortion towards a square‐planar geometry, which should occur upon MLCT excitation, is prevented. On the other hand, in the triplet state the phenyl substituents of the phosphane ligands undergo a rotation which favours radiationless deactivation. As a result, the emission efficiency is relatively small in solution, but much higher in the solid state owing to the rigidity of the lattice. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)
Silanes/Oxygen/(Water): Green High‐Energy‐Density Materials
Authors: Hong Ding Yi , Inagaki Satoshi
Published: June 2005

Design of green high‐energy‐density materials as powerful as the well‐known H2/O2 and N2H4/O2 systems is a never‐ending goal. Here, we study the energetic properties of reactions of silanes with oxygen (and gaseous water) by the bond energy procedure and high‐level quantum chemistry calculations. The silanes/oxygen/(water) reactions finally lead to the green products, namely silica and water or silicic acids that exist in nature. The energy densities of these systems with respect to silica and water are higher than those of the conventional H2/O2 and N2H4/O2 systems. Their energy densities with respect to silicic acids are also higher than or comparable to that of the N2H4/O2 system. We propose that silanes/oxygen/(water) could be powerful green high‐energy‐density materials. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)
Synthesis, Crystal Structure and Characterisation of a Novel Chiral Mixed‐Valence Vanadium Oxide Hybrid, [V5O11(dien)3]
Authors: Fu Ming‐Lai , Guo Guo‐Cong , Wu A‐Qing , Liu Bin , Cai Li‐Zhen , Huang Jin‐Shun
Published: June 2005

The novel chiral mixed‐valence vanadium oxide hybrid [V5O11(dien)3] (1) (dien = NH2C2H4NHC2H4NH2) has been synthesised by a hydrothermal reaction of V2O5 and dien in aqueous solution and characterised by elemental analysis, IR spectroscopy, TG‐DSC analysis, magnetism, EPR spectroscopy, single‐crystal X‐ray diffraction and powder XRD. The X‐ray diffraction analysis revealed that the structure of 1 can be regarded as being constructed from two [VVO4]3– groups bicapping three [VIVO(dien)]2+ units to form a discrete asymmetric pentanuclear vanadium complex with the dien ligands coordinating directly to the vanadium(IV) centres. Compound 1 exhibits an interesting tube‐like 3D supramolecular structure due to abundant hydrogen‐bonding interactions between the oxygen atoms of the inorganic backbone and the hydrogen atoms of the dien ligands from adjacent molecules. The variable‐temperature magnetic susceptibility data of 1 suggest a weak ferromagnetic interaction among V4+ ions in the cluster. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)
A Straightforward Route to Copper/Zinc Oxide Nanocomposites: The Controlled Thermolysis of Zn[Cu(CN)3]
Authors: Guo Yanzhi , Weiss Rainer , Epple Matthias
Published: June 2005

Copper–zinc nanocomposites were prepared by thermolysis of copper–zinc cyanides under mild conditions. Two different routes were used for the preparation of the cyanide complex: A batch precipitation method and the continuous overflow precipitation method. The thermolysis of the cyanides was studied in‐situ by thermogravimetry coupled with infrared spectroscopy (TG‐IR) and by thermogravimetry coupled with mass spectroscopy (TG‐MS). The structure of the nanocomposites was investigated by X‐ray powder diffraction (XRD) and extended X‐ray absorption fine structure (EXAFS). Geometric models were suggested on the atomic scale based on EXAFS results for the precursor, the mixed oxides (CuO/ZnO), and the reduced copper–zinc samples (Cu/ZnO, i. e. catalyst for methanol synthesis). In the batch precipitation method, the influence of temperature on the morphology of the thermolysis products was explored. In the continuous overflow method, the morphology of the Cu–Zn cyanide complex was investigated as a function of concentration and residence time. A high solution concentration and a short residence time (equivalent to a high flow rate) led to smaller particles. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)
Synthesis and Characterization of Heterotrinuclear Complexes of Nickel and Palladium with Pyridinecarboxylate as Bridging Ligands
Authors: Ruiz José , Santana María Dolores , Lozano Abel , Vicente Consuelo , García Gabriel , López Gregorio , Pérez José , García Luis
Published: June 2005

Heterotrinuclear pyridinecarboxylate complexes of nickel(II) and palladium(II) of the types [Ni(mcN3)(pyridinecarboxylate)]2{μ‐[Pd(C6F5)2]}(PF6)2 [mcN3 = 2,4,4‐trimethyl‐1,5,9‐triazacyclododec‐1‐ene (Me3‐mcN3) or 2,4,4,9‐tetramethyl‐1,5,9‐triazacyclododec‐1‐ene (Me4‐mcN3)] have been prepared by two different routes. The corresponding monomeric pyridinecarboxylate complexes of nickel and the monomeric pyridinecarboxylic acid/ester complexes of palladium have also been prepared. The crystal structures of two precursors [Ni(Me4‐mcN3)(NC5H4‐3‐COO)]PF6 and cis‐[Pd(C6F5)2(NC5H4‐4‐CH2COOCH3)2] have been established by X‐ray diffraction. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)
Heparin structures in FGF‐2–dependent morphological transformation of astrocytes
Authors: Nagayasu Toshie , Miyata Seiji , Hayashi Noriko , Takano Ryo , Kariya Yutaka , Kamei Kaeko
Published: June 2005

Fibroblast growth factor‐2 (FGF‐2) participates in the morphological transformation of astrocytes (stellation) during the formation of glial scars in injured brains. In the current study, we used quantitative morphometric analysis to investigate the structural requirements for heparin's enhancement of FGF‐2‐induced stellation of cultured cortical astrocytes. Native heparin significantly promoted FGF‐2‐dependent astrocytic stellation, whereas heparin hexasaccharide inhibited FGF‐2‐dependent stellation. Furthermore, 2‐O‐, 6‐O‐, and N‐desulfated heparins were unable to promote FGF‐2‐dependent stellation. The stellation induced by FGF‐2 or by a combination of FGF‐2 and native heparin was inhibited by SU5402, an FGF receptor inhibitor. These results demonstrate that the length and sulfated position of heparin are important for its enhancement of FGF‐2‐dependent astrocyte stellation. In addition, our findings show that heparin oligosaccharides are useful for regulating the FGF‐2‐dependent astrocytic transformation. © 2005 Wiley Periodicals, Inc. J Biomed Mater Res, 2005
Simple and accurate fracture toughness testing methods for pyrolytic carbon/graphite composites used in heart‐valve prostheses
Authors: Kruzic J. J. , Kuskowski S. J. , Ritchie R. O.
Published: June 2005

The fracture toughness is a critical material property for the pyrolytic carbon materials used in mechanical heart‐valve prostheses; however, making accurate toughness measurements has traditionally been problematic due to difficulties in fatigue precracking specimens. In this work, a simple, effective, and reliable precracking method is presented where a sharp precrack is “popped in” from a razor micronotch, which allows significant savings of time and materials relative to fatigue precracking methods. It is further shown that equivalent results may be obtained using razor micronotched specimens directly without precracking, provided the notch is sufficiently sharp. Indeed, mean toughness values of 1.46 ± 0.13 and 1.35 ± 0.09 MPa√m were obtained for the pyrolytic carbon‐coated graphite materials, using precracked and razor micronotched specimens, respectively. The difference between these mean values proved to be statistically insignificant, and these values are in general agreement with published fracture toughness results obtained using fatigue precracked specimens. © 2005 Wiley Periodicals, Inc. J Biomed Mater Res, 2005
Effect of hybrid layer on stress distribution in a premolar tooth restored with composite or ceramic inlay: An FEM study
Authors: Belli Sema , Eskitaşcioǧlu Gürcan , Eraslan Oǧuz , Senawongse Pisol , Tagami Junji
Published: June 2005

The aim of this finite elemental stress analysis study was to evaluate the effect of hybrid layer on distribution and amount of stress formed under occlusal loading in a premolar tooth restored with composite or ceramic inlay. The mandibular premolar tooth was selected as the model based on the anatomical measurements suggested by Wheeler. The analysis is performed by using a Pentium II IBM compatible computer with the SAP 2000 structural analysis program. Four different mathematical models including the following structures were evaluated: 1) composite inlay, adhesive resin, and tooth structure; 2) composite inlay, adhesive resin, hybrid layer, and tooth structure; 3) ceramic inlay, adhesive resin, and tooth structure; 4) ceramic inlay, adhesive resin, hybrid layer, and tooth structure. Loading was applied from the occlusal surface of the restoration, and shear stresses under loading were evaluated. The findings were drawn by the Saplot program, and the results were analyzed by graphical comparison method. The output indicated that the hybrid layer acts as a stress absorber in models 2 and 4. The hybrid layer has also changed mathematical values of stress on cavity floors in both restoration types. Ceramic inlay collected the stress inside the body of the material, but the composite inlay directly transferred the stress through dental tissues. As a result, it was concluded that the hybrid layer has an effect on stress distribution under loading in a premolar tooth model restored with composite or ceramic inlay. © 2005 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2005
Permeability of adhesive resin films
Authors: Hashimoto Masanori , Tay Franklin R. , Ito Shuichi , Sano Hidehiko , Kaga Masayuki , Pashley David H.
Published: June 2005

The purpose of this study was to quantify the permeability of adhesive resin films to water by measuring convective flow across thin films. Cured resin films were prepared with the use of five commercially available adhesive resins and an experimental resin. Two types of resin films were prepared from solvated comonomer blends within each product; resin films made before or after evaporation of solvent (10 s of drying with air‐syringe). The permeability of the resin films was measured 30 min or 24 h after polymerization by placing the films in a split‐chamber device. Fluid filtration rate through the resin films was measured with the use of 20 cm of water pressure. Osmotically induced water movement was measured by applying hypertonic aqueous solutions of CaCl2 or HEMA to the resin films. The results showed that evaporation of solvent before polymerization reduced the permeability of adhesive resin films, compared to permeabilities obtained without solvent evaporation. The cured adhesive resin films were all permeable to water, but to varying degrees. © 2005 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2005
Genome size and endonuclear DNA replication in spiders
Authors: Rasch Ellen M. , Connelly Barbara A.
Published: June 2005

Although genome sizes (C‐values) are now available for 115 arachnid species (Gregory and Shorthouse [2003] J Hered 94:285–290), the extent of genome amplification (endonuclear DNA replication or polyploidization) accompanying tissue differentiation in this diverse and abundant class of invertebrates remains unknown. To explore this aspect of arachnid development, samples of hemolymph and other tissues were taken from wild‐caught specimens as air‐dried smears, stained with the Feulgen reaction for DNA, and assayed using both scanning and image analysis densitometry. Cells from midgut diverticula and Malpighian tubules of Argiope and Lycosa (=Pardosa) often showed giant nuclei with 50–100 pg of DNA per nucleus, reflecting at least four cycles of endonuclear DNA replication when compared to the DNA content of hemocytes or sperm from the same specimen. Nuclei with markedly elevated DNA levels also appeared, but far less frequently, in tissue samples from several other arachnid species (Antrodiaetus, Hypochilus, Latrodectus, Liphistus and Loxosceles), but revealed no correlation with differences in somatic cell (2C) genome sizes. Our data show that several DNA classes of polysomatic nuclei regularly arise during tissue differentiation in some species of spiders and may provide an interesting model system for further study of patterns of tissue‐specific variation in DNA endoreduplication during development. J. Morphol. © 2005 Wiley‐Liss, Inc.
Isomerization of the protonated acetone dimer in the gas phase
Authors: Norrman K. , Sølling T. I. , McMahon T. B.
Published: June 2005

Mass spectrometry‐based methods have been employed in order to study the reactions of non‐ (h6/h6), half (d6/h6), and fully (d6/d6) deuterium labeled protonated dimers of acetone in the gas phase. Neither kinetic nor thermodynamic isotope effects were found. From MIKES experiments (both spontaneous and collision‐induced dissociations), it was found that the relative ion yield (m/z 65 vs m/z 59) from the dissociation reaction of half deuterium labeled (d6/h6) protonated dimer of acetone is dependent on the internal energy. A relative ion yield (m/z 65 vs m/z 59) close to unity is observed for cold, nonactivated, metastable ions, whereas the ion yield is observed to increase (favoring m/z 65) when the pressure of the collision gas is increased. This is in striking contrast to what would be expected if a kinetic isotope effect were present. A combined study of the kinetics and the thermodynamics of the association reaction between acetone and protonated acetone implicates the presence of at least two isomeric adducts. We have employed G3(MP2) theory to map the potential energy surface leading from the reactants, acetone and protonated acetone, to the various isomeric adducts. The proton‐bound dimer of acetone was found to be the lowest‐energy isomer, and protonated diacetone alcohol the next lowest‐energy isomer. Protonated diacetone alcohol, even though it is an isomer hidden behind many barriers, can possibly account for the observed relative ion yield and its dependence on the mode of activation. Copyright © 2005 John Wiley & Sons, Ltd.
MALDI‐TOF mass spectrometric analysis for the characterization of the 5,10,15,20‐tetrakis‐ (m‐hydroxyphenyl)bacteriochlorin (m‐THPBC) photoproducts in biological environment
Authors: Lassalle Henri‐Pierre , Lourette Natacha , Maunit Benoît , Muller Jean‐François , Guillemin François , Bezdetnaya‐Bolotine Lina
Published: June 2005

Photoproducts formation upon irradiation (739 nm) of 5,10,15,20‐tetrakis(m‐hydroxyphenyl)bacteriochlorin (m‐THPBC) in phosphate buffer saline (PBS) supplemented with human serum albumin (HSA) were studied by means of absorption spectroscopy and MALDI‐TOF mass spectrometry. The experiments were performed with a freshly prepared PBS–HSA solution of m‐THPBC and with a PBS–HSA m‐THPBC solution incubated for 6 h at 37 °C. The incubation of m‐THPBC solution leads to the dye monomerisation, whereas in the freshly prepared solution, m‐THPBC is under an aggregated form. Regardless of the incubation condition, photobleaching experiments carried out by absorption spectroscopy demonstrate the degradation of the photosensitizer and its phototransformation in m‐THPC. Moreover, m‐THPC was the sole photoproduct detected using absorption spectroscopy. Together with a degradation of m‐THPBC and formation of m‐THPC, MALDI‐TOF mass spectrometry evidenced several other photoinduced modifications. Photoproducts such as dihydroxy m‐THPBC and dihydroxy m‐THPC were detected in both conditions; however, the formation of hydroxylated photoproducts was significantly greater in incubated solution. In addition, small molecules arising from the degradation of the photosensitizer and identified as dipyrin derivatives and dipyrrolic synthon were observed. Copyright © 2005 John Wiley & Sons, Ltd.
General anesthetics attenuate gap junction coupling in P19 cell line
Authors: Wentlandt Kirsten , Carlen Peter L. , Kushnir Moshe , Naus Christian C. , El‐Beheiry Hossam
Published: June 2005

Gap junction communication is widespread throughout the mammalian nervous system among neurons as well as glia. We addressed the hypothesis that general anesthetics attenuate gap junction mediated coupling in P19 cell line that can differentiate into neuronal‐like cells and astrocytes and oligodendrocytes. We characterized the extent of dye coupling over time in the P19 cell line using colocalization of chlormethylbenzamido‐1,1 dioctadecyl‐3,3,3′,3′‐tetramethylindocarbocyamine (CM‐DiI) and calcein‐AM in donor and recipient cells in cocultures. After seeding, the gap junction permeant dye calcein spreads from donor to recipient cells. CM‐DiI and calcein fluorescence identified donor and recipient cells, respectively. The extent of intercellular connections was evaluated using cell counting and flow cytometry up to 2 hr after treatment. Clinically relevant concentrations of the intravenous anesthetics propofol (15 μM) and thiopental (10 μM) attenuated gap junction permeability in P19 cell cultures. In contrast, halothane, a volatile anesthetic in a concentration (0.64 mM) relevant to its free aqueous EC50 had no effect on gap junction coupling; however, very high halothane concentrations (2.8 mM) blocked dye transfer by ∼90%. The results indicate that halothane concentrations pertinent to clinical anesthesia were unable to attenuate gap junction communication in a cell line that can express neuronal and glial gap junction proteins; however, clinically relevant concentrations of propofol and thiopental depressed gap junction coupling. © 2005 Wiley‐Liss, Inc.
Screening and construct‐specific detection methods of transgenic Huafan No 1 tomato by conventional and real‐time PCR
Authors: Yang Litao , Shen Huifeng , Pan Aihu , Chen Jianxiu , Huang Cheng , Zhang Dabing
Published: June 2005

Genetically modified (GM) tomatoes have been approved for commercialization in many countries since the first GM tomato FLAVR SAVR was permitted for planting in 1994. In China, GM tomato Huafan No 1 with a character of long shelf‐life was the first GM plant which was approved for commercialization in 1996. To meet the requirement of the GM tomatoes labeling policy that has been actualized in China since 2001, screening and construct‐specific PCR detection methods for detecting the universal elements transformed into tomato, such as cauliflower mosaic virus 35S (CaMV35s) promoter and the nopaline synthase (NOS) terminator of Agrobacterium tumefaciens, and the specifically inserted heterologous DNA sequence between CaMV35s promoter and anti‐sense ethylene‐forming enzyme (EFE) gene were set up. To make the detection methods normative, a novel single copy tomato gene LAT52 was also used as an endogenous reference gene in the PCR detection systems. The limit of detection of screening and construct specific detection methods for Huafan No 1 was 68 haploid genome copies in conventional PCR detection, and three copies in TaqMan real‐time PCR detection. The limit of quantitation of screening quantitative PCR assays for Huafan No 1 was three copies and was 25 copies for construct‐specific quantitative PCR. Two samples with known Huafan No 1 tomato content were detected using the established conventional and real‐time PCR systems, and these results also indicated that the established Huafan No 1 screening and construct‐specific PCR detection systems were reliable, sensitive and accurate. Copyright © 2005 Society of Chemical Industry
On the theory of the amplification of backwards matter waves in a Bose-Einstein condensate of dilute gas
Authors: Avetisyan Yu A , Trifonov E D
Published: June 2005

The solution of the Maxwell-Schrodinger equations describing amplification of backwards matter waves in the process of light scattering from a Bose-Einstein condensate of dilute gas is presented. The results obtained (without the mean field approximation) explain the main features of the effects observed in [1].
Encapsulation of Polypyrrole Chains Inside the Framework of an Ordered Mesoporous Carbon
Authors: Fuertes Antonio B.
Published: June 2005

Summary: This paper reports a facile route to fabricate high‐surface area hybrid carbon‐polymer nanocomposites following a template technique. The method presented here allows large amounts of polymer to be deposited inside one of the pore systems of a highly ordered carbon, while the other is kept empty. Such prepared composite has large polymer loadings (≈50%), high surface area (≈1 000 m2 · g−1), and a uniform porosity made up of mesopores.

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Shape Memory Effect of Bacterial Poly[(3‐hydroxybutyrate)‐co‐(3‐hydroxyvalerate)]
Authors: Kim Young Baek , Chung Chung Wook , Kim Hyung Woo , Rhee Young‐Ha
Published: June 2005

Summary: A bacterial poly[(3‐hydroxybutyrate)‐co‐(3‐hydroxyvalerate)] biosynthesized by Pseudomonas sp. HJ‐2 was found to be a shape memory polymer. Permanent shapes were set by annealing at room temperature the samples that had been pre‐treated above 95 °C in specified shapes. The temporary shapes were set by stretching and holding the elongated samples. Thermal shrinkage began at 45 °C and stopped at 75 °C to recover to their permanent shapes. Apparently, the orientation induced the formation of hard segments that were responsible for setting the temporary shapes. The shape memory effect of this polymer was explained based on the DSC and XRD results at different phases.

The recovery of a coil shape upon heating a strip of HJ‐2 PHB35V, demonstrating the polymers shape memory effect.

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The recovery of a coil shape upon heating a strip of HJ‐2 PHB35V, demonstrating the polymers shape memory effect.
Hyperexcitable polymodal and insensitive nociceptors in painful human neuropathy
Authors: Ochoa José L. , Campero Mario , Serra Jordi , Bostock Hugh
Published: June 2005

Six patients with chronic pain, mechanical and thermal hyperalgesia/allodynia, and cutaneous vasodilatation starting distally in their extremities, were evaluated using clinical and neurophysiological methods and microneurography. Evidence of small‐fiber polyneuropathy was documented in all, but the etiology remained cryptogenic in several. Different forms of hyperexcitability were detected by microneurography in both common polymodal and mechanically insensitive C nociceptors, which explain all the somatosensory abnormalities. Signs of hyperexcitability included reduced receptor threshold (accounting for mechanical and heat allodynias), spontaneous C nociceptor discharge (explaining spontaneous “burning” pain and antidromic vasodilatation), and multiplied nociceptor responses to stimulation (accounting for hyperalgesia). The clinical and electrophysiological profiles of these patients resemble the experimental syndrome evoked by application of capsaicin to the skin. This similarity, and the striking heat dependence of the spontaneous pain, suggest that a common feature may be altered expression or modulation of vanilloid 1 receptor, provoking abnormal nociceptor discharges. Muscle Nerve, 2005