bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effect of osmotic shrinkage and hormones on the expression of Na+/H+ exchanger-1,Na+/K+/2Cl– cotransporter and Na+/K+-ATPase in gill pavement cells of freshwater adapted Japanese eel,Anguilla japonica
Authors: Tse William K. F. , Au Doris W. T. , Wong Chris K. C. 
Published: June 2007

SUMMARYIt is well-known that gill epithelial cells are important in fish osmoregulation. However, studies on the effect of osmotic stress on the direct cellular responses of the gill epithelial cells are limited. In this paper, we aimed to determine the effects of osmotic hypertonicity, hormones and cellular signaling molecules on the expression of ion transporters in the cultured primary freshwater pavement cells (PVCs), prepared from freshwater-adapted eels (Anguilla japonica). Our data demonstrated that the hypertonic(500 mOsmol l–1) treatment of the isolated PVCs induced cell shrinkage, followed by regulatory volume increase (RVI). Application of blockers (i.e. ouabain, bumetanide and EIPA) demonstrated that Na+/K+-ATPase,Na+/K+/2Cl– cotransporter (NKCC) and Na+/H+ exchanger-1 (NHE-1) were involved in RVI. Western blot analysis of the hypertonic-treated cells revealed a significant induction of NHE-1, NKCC and, α and β subunits of Na+/K+-ATPase. In nonshrunken cultured PVCs, we found that dexamethasone and dibutyryl cAMP treatments significantly stimulated the expression levels of the three ion transporters. Both prolactin and insulin-like growth factor-1, can only induce the expression of NKCC. The effect of thyroid hormone (T3) and dibutyryl cGMP was negligible. In this study, the induction of ion transporter expression was found to be post-transcriptionally regulated as no significant change in mRNA levels was detected. This observation implies that the regulation is rapid and is probably induced via nongenomic actions.
Gill-specific transcriptional regulation of Na+/K+-ATPase α-subunit in the euryhaline shore crabPachygrapsus marmoratus: sequence variants and promoter structure
Authors: Jayasundara Nishad , Towle David W. , Weihrauch Dirk , Spanings-Pierrot Céline 
Published: June 2007

SUMMARYThe sodium pump (Na+/K+-ATPase) has been implicated in osmoregulatory ion transport in many aquatic animals. In the euryhaline hyper–hypoosmoregulating shore crab Pachygrapsus marmoratus,induction of Na+/K+-ATPase α-subunit mRNA varies between gills in response to osmotic stress. Following transfer of crabs from normal seawater (36‰ salinity) to diluted seawater (10‰), a condition in which gills exhibit net ion uptake, α-subunit mRNA expression is upregulated in all tested gills, albeit with differing time courses. By contrast, following transfer from seawater to hypertonic(45‰) seawater, a condition in which the animal is excreting ions,α-subunit mRNA is induced primarily in gill no. 7 (nine in total),suggesting that this gill may be associated specifically with ion excretion in P. marmoratus.Full-length sequencing of α-subunit cDNA revealed the existence of two isoforms differing only in the inclusion of an 81-nucleotide segment within the N-terminal open reading frame of the long (D) form in comparison to the short (C) form. The 81-nucleotide segment encodes a 14-3-3 protein binding site that may facilitate movement of the α-subunit protein between intracellular compartments and the plasma membrane. mRNA expression of the two forms followed similar patterns upon salinity transfer. Genomic DNA sequencing of the putative promoter region of the α-subunit gene demonstrated a spectrum of predicted transcription factor binding sites that are likely associated with the complex expression pattern observed among gills following osmotic stress.
Effects of ship noise on the detectability of communication signals in the Lusitanian toadfish
Authors: Vasconcelos Raquel O. , Amorim M. Clara P. , Ladich Friedrich 
Published: June 2007

SUMMARYUnderwater noise pollution is an increasing environmental problem which might affect communication, behaviour, fitness and consequently species'survival. The most common anthropogenic noises in aquatic habitats derive from shipping. In the present study we investigated the implications of noise pollution from a ship on the sound detectability, namely of conspecific vocalizations in the Lusitanian toadfish, Halobatrachus didactylus. Ambient and ferry-boat noises were recorded in the Tagus River estuary(Portugal), as well as toadfish sounds, and their sound pressure levels determined. Hearing sensitivities were measured under quiet lab conditions and in the presence of these masking noises at levels encountered in the field,using the auditory evoked potentials (AEP) recording technique. The Lusitanian toadfish is a hearing generalist, with best hearing sensitivity at low frequencies between 50 and 200 Hz (below 100 dB re. 1 μPa). Under ambient noise conditions, hearing was only slightly masked at lower frequencies. In the presence of ship noise, auditory thresholds increased considerably, by up to 36 dB, at most frequencies tested. This is mainly because the main energies of ferry-boat noise were within the most sensitive hearing range of this species. Comparisons between masked audiograms and sound spectra of the toadfish's mating and agonistic vocalizations revealed that ship noise decreased the ability to detect conspecific acoustic signals. This study provides the first evidence that fishes' auditory sensitivity can be impaired by ship noise and that acoustic communication, which is essential during agonistic encounters and mate attraction, might be restricted in coastal environments altered by human activity.
The role of metals in molluscan adhesive gels
Authors: Werneke S. W. , Swann C. , Farquharson L. A. , Hamilton K. S. , Smith A. M. 
Published: June 2007

SUMMARYSeveral gastropod molluscs produce glues that are interesting because they are dilute gels and yet they produce strong adhesion. Specific glue proteins have been identified that play a central role in this adhesion, possibly by crosslinking other polymers in the gel. This study investigates the role of metals in the action of these glue proteins. Atomic absorption spectrometry showed that glue from the slug Arion subfuscus contains substantial quantities of zinc (46±7 p.p.m. and 189±80 p.p.m. in two different sets of experiments) and also iron, copper and manganese (2–7 p.p.m.). Iron-specific staining demonstrates that iron is bound specifically to the 15 kDa glue protein. Several approaches were used to show that these metals have important functional effects. Adding iron or copper to dissolved glue causes the proteins to precipitate rapidly, although zinc has no effect. Removing iron and related transition metals with a chelator during secretion of the glue causes a sixfold increase in the solubility of the glue. Once the glue has set, however, removing these metals has no effect. Finally, the gel-stiffening activity of the glue proteins was measured in the presence and absence of the chelator. The chelator eliminated the gel-stiffening effect of the proteins, suggesting that transition metals were necessary for the proteins to act on the gel. Thus, the glue contains transition metals and these metals play an essential role in glue function.
The application of an exhaust heat exchanger to protect the catalyst and improve the fuel economy in a spark-ignition engine
Authors: Lee Seokhwan , Bae Choongsik 
Published: June 2007

A close-coupled catalyst (CCC) can reduce engine cold-start emissions by utilizing the energy in the exhaust gas. However, in case the engine is operated at high engine speed and load condition, the catalytic converter may be damaged and eventually deactivated by thermal ageing. Excess fuel is sometimes supplied intentionally to lower the exhaust gas temperature, avoiding thermal ageing. This sacrifices fuel economy and exhaust emissions. This paper describes the results of an exhaust heat exchanger to lower the exhaust gas temperature, mainly under high load conditions. The heat exchanger was installed between the exhaust manifold and the inlet of the CCC to avoid thermal ageing. The exhaust heat exchanger successfully decreased the exhaust gas temperature, which eliminated the requirement of fuel enrichment under high-load conditions. A reduction of fuel consumption by approximately 7.7 per cent at high vehicle speed was achieved due to no fuel enrichment. Although the amount of hydrocarbon during the cold start increases due to the increment of the catalyst light-off time, it still meets the EURO-IV regulations. This problem could be resolved by adopting the solenoid valve to cut off the coolant at the inlet of the coolant passage of the heat exchanger.
Maspin Is Involved in Bone Matrix Maturation by Enhancing the Accumulation of Latent TGF-β
Authors: Tokuyama Reiko , Satomura Kazuhito , Maeda Eriko , Kudoh Keiko , Yamasaki Yasuhumi , Nagayama Masaru 
Published: June 2007

Abstract
Maspin, a serine protease inhibitor, is expressed by formative osteoblasts. The repression of maspin expression in osteoblastic cells decreased the level of latent TGF-β in the extracellular matrix, whereas the overexpression of maspin increased latent TGF-β. These findings suggest that maspin plays an important role in bone matrix formation, particularly in the accumulation of latent TGF-β.
Introduction: Maspin is a serine protease inhibitor that exhibits tumor suppressive and anti-angiogenic activities. This study was performed to elucidate a possible role for maspin in bone formation.
Materials and Methods: We performed immunohistochemical analysis of the expression of maspin during endochondral ossification. We evaluated the expression of maspin mRNA and protein in ROS 17/2.8 cells and primary rat osteoblastic cells by RT-PCR, immunocytochemistry, and Western blot analysis. We also examined the accumulation of TGF-β in the extracellular matrix of cultured ROS 17/2.8 cells after transfection with vectors expressing either maspin or maspin antisense.
Results: We observed expression of maspin by active osteoblasts in vivo. Rat osteoblastic cells also expressed maspin mRNA and protein in vitro. Moreover, the accumulation of latent TGF-β in the extracellular matrix significantly decreased in cultures exposed to an anti-maspin antibody and when cells were transfected with a maspin antisense-expressing vector. In contrast, accumulation of latent TGF-β in the extracellular matrix increased after transfection of cells with a vector expressing maspin.
Conclusions: These findings suggest that maspin expressed in active osteoblasts plays an important physiological role during maturation of the bone matrix, and in particular, during the process of accumulation of latent TGF-β in the extracellular matrix.
Factors Associated with Contraceptive Use and Nonuse, United States, 2004
Authors: Frost Jennifer J. , Singh Susheela , Finer Lawrence B. 
Published: June 2007

CONTEXT:  Each year, nearly one in four U.S. women at risk of unintended pregnancy experience one or more months of contraceptive nonuse. Understanding what factors are associated with risky contraceptive use patterns can inform programs and policies designed to reduce levels of unintended pregnancy. METHODS:  A nationally representative sample of 1,978 adult women at risk for unintended pregnancy was surveyed over the telephone in 2004. Respondents provided information on contraceptive use over the past 12 months. Multiple logistic regressions were used to identify factors associated with different contraceptive use patterns. RESULTS:  Ambivalence about avoiding pregnancy was strongly associated with both contraceptive nonuse and having a gap in use while remaining at risk of unintended pregnancy (odds ratios, 2.4 and 2.0, respectively). Other significant predictors of either of these risky contraceptive behaviors were having less than a college education, being black, being 35–44 years old, having infrequent sexual intercourse, not being in a current relationship, being dissatisfied with one’s method and believing that contraceptive service providers were not available to answer method‐related questions (1.7–3.8). CONCLUSIONS:  Providers could better help women avoid unintended pregnancy by initiating regular assessments of method use difficulties, improving counseling on method choice and pregnancy risk, and identifying and assisting women at higher risk for inconsistent method use because of disadvantage, relationship characteristics or ambivalence about pregnancy prevention. In addition to providers’ efforts, broader societal commitment is critical for increasing contraceptive knowledge and expanding access to contraceptive care for all women who are at risk of having an unintended pregnancy.
Monosomy 7 with severe myelodysplasia developing during imatinib treatment of Philadelphia‐positive chronic myeloid leukemia: Two cases with a different outcome
Authors: Navarro José‐Tomás , Feliu Evarist , Grau Javier , Espinet Blanca , Colomer Dolors , Ribera Josep‐Maria , Oriol Albert , Granada Isabel , Juncà Jordi , Millá Fuensanta 
Published: June 2007

AbstractChromosomal abnormalities in Ph‐negative metaphases from patients with chronic myeloid leukemia (CML) treated with imatinib have been described in some cases. Trisomy 8 is the most frequent, but monosomy 7 has also been described. However, the association of these chromosomal alterations with myelodysplasia has been scarcely reported. We report the appearance of monosomy 7 in Ph‐negative cells, associated with severe dysplasia, in two patients with CML treated with imatinib, with a different outcome: one with a transient evolution and the other evolving to acute myeloid leukemia. Am. J. Hematol., 2007. © 2007 Wiley‐Liss, Inc.
Synthesis and characterization of novel star polymer with β‐cyclodextrin core and its metal complexes
Authors: Jiang Yan , Zhang Hongwen , Du Lianxiang , Zhang Kai , Wang Jingyuan 
Published: June 2007

AbstractA novel star polymer with β‐cyclodextrin (β‐CD) core and polyacrylonitrile arms and its metal complexes (Cu2+, Zn2+, and Ag+) were synthesized and characterized by means of infrared spectra, ultraviolet, GPC, X‐ray photoelectron spectroscopy, differential scanning calorimetry, cyclic voltammetry, and electron spin resonance. The results indicate that the monomers of acrylonitrile were initiated by functionalized β‐CD. The thermal properties of star polymer were improved greatly after transitional metal ions were introduced into it. The novel star polymer metal complexes possess properties of metal ions, polymer, and β‐CD. Furthermore, it shows stable electrochemical activity. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007
Characterization of liquefied wood residues from different liquefaction conditions
Authors: Pan Hui , Shupe Todd F. , Hse Chung‐Yun 
Published: June 2007

AbstractThe amount of wood residue is used as a measurement of the extent of wood liquefaction. Characterization of the residue from wood liquefaction provides a new approach to understand some fundamental aspects of the liquefaction reaction. Residues were characterized by wet chemical analyses, Fourier transform infrared (FTIR) spectroscopy, X‐ray diffraction (XRD), and scanning electron microscopy (SEM). The Klason lignin content of the residues decreased, while the holocellulose and α‐cellulose contents increased as the phenol to wood ratio (P/W) increased. A peak at 1735 cm−1, which was attributed to the ester carbonyl group in xylan, disappeared in the FTIR spectra of the residues from liquefied wood under a sealed reaction system, indicating significantly different effects of atmospheric versus sealed liquefaction. The crystallinity index of the residues was higher than that of the untreated wood particles and slightly increased with an increase in the P/W ratio. The SEM images of the residues showed that the fiber bundles were reduced to small‐sized bundles or even single fibers as the P/W ratio increased from 1/1 to 3/1, which indicated that the lignin in the middle lamella had been dissolved prior to the cellulose during liquefaction. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2007
Synthesis of monomethoxy poly(ethylene glycol) without diol poly(ethylene glycol)
Authors: Zhang Jing , Zhao Yong‐Jiang , Su Zhi‐Guo , Ma Guang‐Hui 
Published: June 2007

AbstractSince monomethoxy poly(ethylene glycol) (mPEG) inevitably contains diol PEG and is difficult to get high molecular weight through traditional synthesis at high temperature under high pressure, a novel synthetic technique via anionic solution polymerization was reported in this study. With a new initiating system, potassium naphthalene and methanol, was introduced, the polymerization proceeded at ambient temperature and side reactions were well restrained. Furthermore, a slight excess of potassium naphthalene can effectively remove the trace of water and oxygen in the reaction system. Under this condition, mPEG was nearly quantitatively obtained without containing diol PEG. Its Mn ranged from 1 to 30 kDa and the polydispersity was kept lower than 1.07. Characterization of the mPEG obtained was carried out using GPC to determine the content of diol PEG and 1H‐NMR and MALDI‐ToF MS spectroscopic analysis to confirm the exact structure. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2007
Curing and thermal behavior of DGEBA in presence of dianhydrides and aromatic diamine
Authors: Jain Ritu , Choudhary Veena , Narula A. K. 
Published: June 2007

AbstractThe article describes the curing behavior of diglycidyl ether of bisphenol‐A using benzophenone 3,3′, 4,4′‐tetracarboxylic acid dianhydride (BTDA)/naphthalene 1,4,5,8‐tetracarboxylic dianhydride (NTDA)/or mixture of BTDA and 4,4′‐ diaminodiphenyl sulfone (DDS)/ or NTDA and DDS in varying molar ratio as curing agent. Differential scanning calorimetry was used to investigate the cure kinetics by recording DSC scans at heating rates of 5, 10, 15, and 20 °C/min. The peak exotherm temperature was found to be dependent on the heating rate, structure of the dianhydride as well as on the DDS/dianhydride molar ratio. Activation energy of curing reaction as determined in accordance to Ozawa's method was found to be dependent on the structure of anhydride as well as on the ratio of anhydride to amine. Thermal stability of the isothermally cured resins was evaluated using dynamic thermogravimetry in nitrogen atmosphere. The char yield was highest in case of resins cured using DDS/BTDA mixture or DDS/NTDA one (0.75 : 0.25; sample EB‐1/or EN‐1). © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2007
Reswelling transition of poly(sodium acrylate) gels due to destruction of hydrogen bonds observed by ATR FTIR spectroscopy
Authors: Sato Hiroaki , Hirashima Yumiko , Suzuki Atsushi 
Published: June 2007

AbstractWe report the reswelling transition of a physically crosslinked polyelectrolyte hydrogel in water, which was prepared using poly(sodium acrylate) as the main constituent and Al ions as the crosslinker. The nonmonotonic swelling behavior was observed at room temperature (25°C) under the continuous exchange of water; an as‐prepared gel swelled at the first stage (the swelling process) and then shrunk very slowly at the second stage (deswelling process). In the deswelling process, the water exchange was stopped and the diameter of the gel in a limited amount of water was measured as a function of the temperature. The gels reswelled at different transition temperatures in the heating processes, which depended on the initial diameter at 25°C (resulting from the different numbers of water exchange). The reswollen state was stable at 25°C and could shrink again as a result of successive water exchanges at 25°C. In the following temperature increase in the closed system, the reswelling phenomenon was observed again. The destruction of the hydrogen bonds introduced by the water exchange was confirmed by the attenuated total refraction Fourier transform infrared measurements. The reversible transition behavior between the deswollen and the reswollen states is discussed in terms of the formation and destruction of the hydrogen bonds. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007
Effect on properties of regenerated silk fibroin fiber coagulated with aqueous methanol/ethanol
Authors: Zuo Baoqi , Liu Leigen , Wu Zhengyu 
Published: June 2007

AbstractRandom coil silk fibroin membrane was designed to dissolve with HFIP, and regenerated silk fibroin fibers were obtained by wet spinning. The effect of coagulants (methanol and ethanol) on structure, mechanical properties, and actinomyces biodegradability of regenerated silk fibroin fiber was investigated through X‐ray diffraction, IR spectra, and TGA. The results showed that the effect on the structure and properties of regenerated silk fibroin fibers coagulated by methanol and ethanol was negligible, but the difference in actinomyces biodegradability in vitro was obvious. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007
Morphology, deformation behavior and thermomechanical properties of polypropylene/maleic anhydride grafted polypropylene/layered silicate nanocomposites
Authors: Dubnikova I. L. , Berezina S. M. , Korolev Yu. M. , Kim G.‐M. , Lomakin S. M. 
Published: June 2007

AbstractNanocomposites polypropylene (PP) with 3 and 7 wt % of clay were prepared by melt mixing. Four types of maleic anhydride grafted PP (MAPP) in broad range of MA groups content (0.3–4 wt %) and molecular weights (MW) were used as polar compatibilizers. The effect of the MAPP kind on both the clay dispersion and miscibility with PP was studied. The mixed intercalated/exfoliated morphologies of nanocomposites in the presence of all studied compatibilizers were revealed by XRD and TEM. The oligomer compatibilizer with 4 wt % of MA groups increases the intercalation ability of polymer into clay galleries but this one has limited miscibility with PP and worsens crystalline structure of polymer matrix. The MAPPs with 0.3–1.3% of MA are characterized by the lower intercalation ability but well cocrystallize with PP. Maximum reinforcing effect is attained using high MW MAPP with 0.6% MA and for nanocomposite with 7 wt % (3.8 vol %) of clay it averages almost 1.7 times relative to neat PP and 1.3 times relative to noncompatibilized composite. Dynamic storage moduli of nanocomposites compatibilized by MAPPs with 0.3–1.3% of MA containing 7 wt % of clay increase up to 1.4–1.5 around 30–75°C and over the whole temperature range remain higher compared with both neat PP and uncompatibilized composite. On the contrary, the oligomer MAPP with 4 wt % of MA groups decreases the thermal–mechanical stability of nanocomposite at high temperature compared with both PP and uncompatibilized composites. The study of nanocomposites flammability showed that creating complex composites containing both layered silicate and relatively small amount of magnesium hydroxide can be a successful approach to reduce the combustibility of PP‐based nanocomposites. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007