bluuebunny/crossref_metadata_2025_split huggingface dataset:
Synthesis and characterization of star polymers initiated by hexafunctional discotic initiator through atom transfer radical polymerization
Authors: Feng Xiao‐Shuang , Pan Cai‐Yuan 
Published: October 2004

AbstractA novel hexafunctional discotic initiator, 2,3,6,7,11,12‐hexakis(2‐bromobutyryloxy)triphenylene (HBTP), was synthesized by the esterification of 2,3,6,7,11,12‐hexahydroxytriphenylene with 2‐bromobutyryl chloride. Atom transfer radical polymerizations of styrene, methyl acrylate, and n‐butyl acrylate were carried out in 50 vol % tetrahydrofuran with HBTP/copper(I) bromide/2,2′‐bipyridyl as an initiation system. The polymers produced had well‐controlled molecular weights and narrow molecular weight distributions (<1.2). On the basis of 1H NMR spectra of the star polymer and its hydrolyzed products, we can conclude that the initiator quantitatively initiated the polymerization of vinyl monomers and that a star polymer with a discotic core was obtained. © 2001 John Wiley & Sons, Inc. J Polym Sci Part A: Polym Chem 39: 2233–2243, 2001
Mechanistic study of trans⇆cis isomerization of the substituted azobenzene moiety bound on a liquid‐crystalline polymer
Authors: Ho Chao‐Hsien , Yang Kai‐Nung , Lee Sung‐Nung 
Published: October 2004

AbstractA mechanistic study of the trans⇆cis isomerization of the azobenzene moiety in a side‐chain liquid‐crystal polymer system was carried out with six liquid‐crystalline polymethacrylates in which different electron‐withdrawing substituents were attached to the para‐positions of the azobenzene chromophores. Compared to the non‐nitro‐substituted azo polymers, the nitro‐substituted azo polymers exhibited two quite different behaviors: an extraordinarily high reaction rate of the thermal cis–trans isomerization and an unexpected composition of cis–trans isomers obtained from the photochemical trans–cis isomerization process. A potential energy profile for the isomerization process was established on basis of the structures of the proposed transition states and was employed to elucidate the reaction mechanism. The results confirmed that the nitro‐substituted azo polymer system proceeded via a rotation mechanism in either direction of the trans⇆cis isomerization reaction, whereas the non‐nitro‐substituted species were more likely to follow an inversion mechanism. © 2001 John Wiley & Sons, Inc. J Polym Sci Part A: Polym Chem 39: 2296–2307, 2001
Kinetics of the volume phase transition in poly(n‐isopropylacrylamide) gels prepared under high pressure
Authors: Kitada Tadayosi 
Published: October 2004

AbstractNew poly(N‐isopropylacrylamide) gels were prepared under high pressure (ca. 200 MPa) during gelation. The preparation‐pressure dependence of the deswelling speed of the gels was measured with a conventional T‐jump method. The deswelling time of a gel rod 2.2 mm in diameter prepared at 193 MPa was about 200 s, 1000 times faster than that of a homogeneous poly(N‐isopropylacrylamide) gel. Moreover, the collective diffusion coefficient, the thermal fluctuation, and the ensemble‐average intensity of the swollen gel networks were obtained with dynamic light scattering measurements. Both the enthalpy and entropy of the gels were estimated from equilibrium swelling curves with the Flory–Huggins interaction parameter evaluated with mean field theory based on the Flory‐type of the Gibbs free‐energy formula. It was found that the networks of the gels had an inhomogeneous structure newly introduced by the preparation pressure. © 2001 John Wiley & Sons, Inc. J Polym Sci Part A: Polym Chem 39: 2315–2325, 2001
Correlation between local mobility and mechanical properties of high‐speed melt‐spun nylon‐6 fibers
Authors: Kwak Seung‐Yeop , Kim Jun Hyung , Lee Jong‐Chan 
Published: October 2004

AbstractThis article establishes the processing–microstructure–motion–property relationship of high‐speed melt‐spun nylon‐6 fibers. From solid‐state 1H NMR T1ρ (spin–lattice relaxation time in the rotating frame) relaxation studies, all nylon‐6 fibers spun at 4500–6100 m/min showed three‐component exponential decay with the time constants T1ρ,I, T1ρ,II, and T1ρ,III, indicating that there existed three different motional phases. These phases were assigned to immobile crystalline, intermediate rigid amorphous, and mobile amorphous regions. The determination of the correlation time (τc) of the respective phases provided information about the local molecular mobility of each phase with respect to the spinning speed. As the spinning speed increased, τc of the crystalline region increased (4500–5200 m/min) and then reached a plateau. However, τc for the rigid amorphous region increased from 5200 m/min onward, indicating that the rigid amorphous chains were more oriented and constrained in the spinning speed range of 5500–6100 m/min. The drastic increase of the maximum thermal stress for all fibers from 5500 to 6100 m/min was coincident with the τc characteristics of the rigid amorphous region. The significant increase in tenacity and Young's modulus and the large decrease in elongation at break at 5500–6100 m/min were also in good agreement with the local molecular motion of the intermediate rigid amorphous phase in the nylon‐6 fibers. © 2001 John Wiley & Sons, Inc. J Polym Sci B: Polym Phys 39: 993–1000, 2001
Poly(ester amide)s derived from glycine, even‐numbered diols, and dicarboxylic acids: Considerations on the packing
Authors: Paredes N. , Casas M. T. , Puiggalí J. 
Published: October 2004

AbstractA new sequential poly(ester amide) derived from 1,12‐dodecanediol, sebacic acid, and glycine was synthesized and characterized. Its crystalline structure was studied with transmission electron microscopy and X‐ray diffraction. The results were compared with results for a related polymer, derived from glycine, 1,6‐hexanediol, and succinic acid, that produced a lower methylene/carbonyl ratio. The crystalline structures of both polymers corresponded to a periodic arrangement of two layers of hydrogen‐bonded molecular chains, whose polymethylene sequences mimicked the packing of polyethylene and the majority of polyesters. © 2001 John Wiley & Sons, Inc. J Polym Sci B: Polym Phys 39: 1036–1045, 2001
Effect of aromatic substitution on phase behavior of blends of halogenated polystyrene and conventional polystyrene
Authors: Thaweephan Pawiga , Meng Scott , Sigalov Grigori , Koo Hyun , Sung Kim , Choi Ho , Kyu Thein 
Published: October 2004

AbstractMiscibility phase behavior in blends of poly(bromostyrene) with polystyrene (PS) has been investigated by means of time‐resolved light scattering, optical microscopy, and DSC. Cloud point phase diagrams of blends of conventional PS with poly‐(2‐bromostyrene) (P2BrS), poly‐(3‐bromostyrene), and poly‐(4‐bromostyrene) of comparable molecular weights were established by light scattering. Of particular interest is the fact that ortho, meta, and para substitutions in the styrenic aromatic rings of poly(bromostyrene) show profound effects on the composition–temperature phase diagrams of their blends with PS, exhibiting a lower critical‐solution temperature (LCST), an upper critical solution temperature (UCST), and combined LCST/UCST diagrams, respectively. Poly‐(2‐chlorostyrene) exhibits an LCST behavior very close to that of the P2BrS blend, suggesting that these types of halogen atoms may be inconsequential to phase behavior. A similar study has been extended to a PS blend containing commercial brominated PS (66 mol % bromine substitution) to determine what location of bromine substitution is crucial for miscibility enhancement in the flame‐retardant brominated PS blends. © 2001 John Wiley & Sons, Inc. J Polym Sci Part B: Polym Phys 39: 1605–1615, 2001
Effects of single‐dose fluticasone on exercise‐induced asthma in asthmatic children: A pilot study*
Authors: Thio B.J. , Slingerland G.L.M. , Nagelkerke A.F. , Roord J.J. , Mulder P.G.H. , Dankert‐Roelse J.E. 
Published: October 2004

AbstractA single high dose of inhaled corticosteroid (ICS) can increase airway caliber in children with asthma attacks and laryngitis subglottica. Presumably the effect is due to the vasoconstrictive and antiedematous properties of topical steroids. Enlarged vessels have been suggested to play a role in the pathophysiology of exercise‐induced bronchial obstruction (EIB). To investigate this, we evaluated the effect of a single high dose of fluticasone propionate (FP) on EIB in asthmatic children. Nine children aged 8–16 years with mild to moderate asthma were included. All children had a history of EIB, which was confirmed by an exercise test. None was taking ICS maintenance therapy. The children inhaled either a single dose of 1 mg FP or placebo on 2 separate days within 7–14 days. After inhalation, airway caliber (FEV1) was assessed for 4 hr before exercise. Then an exercise challenge was performed on a treadmill to assess EIB (% fall FEV1).A significant increase in FEV1 was observed 1 hr after inhalation of FP compared to placebo. Response to exercise was expressed as maximal % fall in FEV1 from baseline (% fall) and as area under the curve (AUC) of the 30‐min time/response curve. The % fall FEV1 after exercise and the AUC were significantly reduced when FP was inhaled compared to placebo inhalation (% fall 9.7% vs. 19.2%, respectively, P = 0.038 and AUC 92.0%ċmin vs. 205.7%ċmin, respectively, P = 0.03). There was considerable individual variability in reduction of EIB, with 5 out of 9 children having a clinically significant response.We conclude that a single high dose of inhaled FP has an acute protective effect on the bronchial response to exercise in a substantial proportion of asthmatic children. Pediatr Pulmonol. 2001; 32:115–121. © 2001 Wiley‐Liss, Inc.
Intratracheal administration of perfluorochemical‐gentamicin suspension: A comparison to intravenous administration in normal and injured lungs*
Authors: Cox Cynthia A. , Cullen Aaron B. , Wolfson Marla R. , Shaffer Thomas H. 
Published: October 2004

AbstractRespiratory infections can lead to acute lung injury and perfusion abnormalities. We hypothesized that intratracheal (IT) administration of a perfluorochemical (PFC) gentamicin (G) suspension as compared to intravenous (IV) administration of gentamicin will result in higher lung tissue levels of gentamicin, while maintaining safe serum levels. To test this hypothesis, 21 lambs with normal and acid injured lungs were studied for 4 hr, using 2 different drug delivery methods, IT and IV. Lungs were injured with warm HCl acid in saline lavage, followed by partial liquid ventilation with perflubron (bolus FRC = 20 mL/kg). G at a dose of 5 mg/kg was delivered either IT (G‐PFC; 20 mL/kg) or IV (aqueous injection with IT 20 mL/kg PFC alone). Throughout the study, serum G levels, arterial blood gases, respiratory system compliance, and mean arterial blood pressure were measured. Lung tissue G levels were measured at 4 hr and averaged across lobes. Physiologic gas exchange and pulmonary function were maintained throughout the protocol for both the normal and injured lungs.Intravenously administered G resulted in an initial 5‐min serum concentration of 43 ± 2.5 mcg/mL, followed by an exponential decline over the 4‐hr protocol to a level of 2.1 ± 0.23 mcg/mL at hr 4. The intratracheally administered G suspension resulted in a 5‐min serum concentration of 1.8 ± 0.98 mcg/mL and remained relatively constant throughout the protocol, with a 4‐hr level of 1.6 ± 0.29 mcg/mL. With respect to lung tissue G levels, IT administration was significantly more effective in delivering the drug to the normal lungs than IV (31.4 ± 3.3 mcg/g vs. 4.0 ± 0.7 mcg/g) 4 hr after administration. In the lung injury group, there was a small but significant difference in lung tissue G levels, with the IT‐administered perfluorochemical‐G suspension achieving greater levels than the IV‐administered G (11.9 ± 0.52 mcg/g vs. 10.1 ± 0.8 mcg/g). Additionally, the drug delivered IV and IT in both the normal and injured lung models was homogeneously distributed throughout the lung.These data show that G lung tissue levels in both normal and injured lungs were higher in the IT group when compared to IV administration. The results of this study demonstrate that in normal and injured lungs, homogeneous G lung tissue levels can be more effectively achieved at lower serum levels when delivered IT in a G‐PFC suspension as compared to IV administration. Pediatr Pulmonol. 2001; 32:142–151. © 2001 Wiley‐Liss, Inc.
Pulmonary involvement in a child with ligneous conjunctivitis and homozygous type I plasminogen deficiency
Authors: Özçelik Uǧur , Akçören Zuhal , Anadol Deniz , Kiper Nural , Orhon Mehmet , Göçmen Ayhan , Irkeç Murat , Schuster Volker 
Published: October 2004

AbstractLigneous conjunctivitis (LC) is a rare disorder characterized by a chronic course of recurrent membranous lesions at conjunctivae. Pseudomembranes of other mucous membranes have been reported in patients with LC, but to the best of our knowledge, no case with alveolar involvement has been described. Here, we report a 2.5‐year‐old girl with LC who had tracheoaveolar involvement and homozygous type I plasminogen deficiency. Tracheal involvement was diagnosed by bronchoscopic biopsy and alveolar involvement with postmortem biopsy. She was shown to be homozygous for frameshift mutation in plasminogen exon 14 (Gly565ins‐G) with molecular genetic examination of DNA which was obtained from parafin embedded postmortem lung tissue. Ligneous inflammation of the upper and lower respiratory tract must be considered in children with LC and recurrent respiratory tract problems. Pediatr Pulmonol. 2001; 32:179–183. © 2001 Wiley‐Liss, Inc.
Androgen regulation of spermidine synthase expression in the rat prostate*
Authors: Cyriac Jomol , Haleem Riffat , Cai Xiaoyan , Wang Zhou 
Published: October 2004

AbstractBACKGROUNDSpermidine synthase, an essential enzyme in the polyamine synthesis pathway, was identified as one of the androgen‐response genes in the rat ventral prostate. Characterization of androgen regulation of spermidine synthase is important to the understanding of androgenic regulation of polyamine synthesis.METHODSFull‐length cDNA encoding rat spermidine synthase was isolated from a λZAP cDNA phage library. Young male adult Sprague‐Dawley rats were used for castration and androgen replacement. Northern blot and in situ hybridization were used to characterize gene expression.RESULTSThe amino acid sequence of rat spermidine synthase shares 99% and 94% identity with that of mouse and human spermidine synthase, respectively. Spermidine synthase gene is abundantly expressed and regulated by androgens in the ventral, dorsal, and lateral lobes of the rat prostate, and its expression is localized to the epithelial cells. Spermidine synthase also is regulated by androgens in the seminal vesicles but not in the muscle, brain, kidney, thymus, heart, or liver, suggesting that this enzyme is responsive to androgen in the male sex accessory organs only. The expression of spermidine synthase and two other enzymes involved in polyamine synthesis, S‐adenosylmethionine decarboxylase and ornithine decarboxylase, are regulated by androgens coordinately.CONCLUSIONSSpermidine synthase is most abundantly expressed and regulated by androgens in the prostatic epithelial cells, suggesting that regulation of spermidine synthase is likely a key step in coordinated androgen regulation of polyamine synthesis in the prostate. Prostate 50: 252–261, 2002. © Wiley‐Liss, Inc.
Effectiveness of mass screening for the prognosis of prostate cancer patients in Japanese communities
Authors: Kubota Yutaka , Ito Kazuto , Imai Kyoichi , Yamanaka Hidetoshi 
Published: October 2004

AbstractBACKGROUNDA study was conducted to investigate the effectiveness of mass screening (MS) for prostate cancer in Japanese communities using the long‐term follow‐up results.METHODSSubjects were 279 patients with prostate cancer detected by MS in Gunma prefecture (MS group) and 624 patients with prostate cancer who did not undergo screening (non‐MS group). From the follow‐up data, the prognoses were compared between the groups.RESULTSThe ratio of patients with Stage II cancer was higher for the MS group (59.1%) when compared to non‐MS group (25.3%). As a whole, the prognosis of the MS group was more favorable than that of the non‐MS group for relative survival rate. Prognosis was especially favorable for patients with Stage III prostate cancer in mass screening group considering the effect of lead‐time bias.CONCLUSIONSEarly detection and longer survival of the patients with prostate cancer detected by mass screening suggested the effectiveness of prostate cancer screening. Prostate 50: 262–269, 2002. © Wiley‐Liss, Inc.
Antitumor effect of an HER2‐specific antibody–toxin fusion protein on human prostate cancer cells
Authors: Wang Ling , Liu Bolin , Schmidt Mathias , Lu Yang , Wels Winfried , Fan Zhen 
Published: October 2004

AbstractBACKGROUNDHER2/neu has been implicated in the oncogenesis of human prostate cancer. Clinical studies have suggested that overexpression of HER2 may be one of the indicators of poor prognosis in prostate cancer patients.METHODSWe used Western blot analysis to examine the expression of HER2 in a panel of established human prostate cancer cell lines and used an MTT assay to evaluate the cytotoxicity on these cells of a recombinant fusion protein consisting of an HER2‐specific single‐chain antibody and the Pseudomonas exotoxin A, scFv(FRP5)‐ETA.RESULTSLNCaP cells express high levels of HER2 protein. Exposure of LNCaP cells to scFv(FRP5)‐ETA caused remarkable cell death. In contrast, PC3M cells, which express an undetectable level of HER2 protein, were resistant to scFv(FRP5)‐ETA‐induced cytotoxicity. MDA PCa 2a, MDA PCa 2b, and DU145 cells express low‐to‐medium levels of HER2 protein and showed an HER2 level‐dependent response to scFv(FRP5)‐ETA‐induced cytotoxicity. The scFv(FRP5)‐ETA‐induced cytotoxicity of LNCaP cells could be inhibited by an anti‐HER2 monoclonal antibody (mAb), which downregulated the levels of HER2 protein, indicating the specificity of scFv(FRP5)‐ETA in inducing cytotoxicity in LNCaP cells. Using an apoptosis ELISA, we demonstrated that scFv(FRP5)‐ETA induced apoptosis in LNCaP cells. The apoptosis was inhibited by the presence of dihydrotestosterone (DHT) in culture medium. Exposure of LNCaP cells to scFv(FRP5)‐ETA caused reduction in the level of the prostate‐specific antigen (PSA).CONCLUSIONSOur data suggest that scFv(FRP5)‐ETA might be a useful agent for the treatment of human prostate cancer cells with high levels of HER2 expression. Prostate 47:21–28, 2001. © 2001 Wiley‐Liss, Inc.
Pathological features of prostate cancer detected on initial and repeat prostate biopsy: Results of the prospective European prostate cancer detection study
Authors: Djavan Bob , Mazal Peter , Zlotta Alex , Wammack Robert , Ravery Vincent , Remzi Mesut , Susani Martin , Borkowski Andrzej , Hruby Stefan , Boccon‐Gibod Laurent , Schulman Claude C. , Marberger Michael 
Published: October 2004

AbstractBACKGROUNDWe evaluated pathological features of prostate cancer detected on repeat prostate biopsy in men with a serum total prostate‐specific antigen (PSA) level between 4 and 10 ng/ml who were diagnosed with benign prostatic tissue after an initial biopsy and compared them to those cancers detected on initial prostate biopsy.METHODSIn this prospective European prostate cancer detection study, 1,051 men with a total PSA level between 4 and 10 ng/ml underwent transrectal ultrasound (TRUS)–guided sextant biopsy and two additional transition zone biopsies. All subjects whose biopsy samples were negative for prostate cancer (CaP) underwent a repeat biopsy after 6 weeks. Those with clinically localized cancers underwent radical prostatectomy. Pathological and clinical features of patients diagnosed with cancer on either initial or repeat biopsy and clinically organ confined disease who agreed to undergo radical prostatectomy were compared.RESULTSInitial biopsy was positive (CaP) in 231 of 1,051 enrolled subjects and negative (benign histology) in 820 subjects. Of these 820 subjects, CaP was detected in 10% (83/820) upon repeat biopsy. Of cancers detected on initial and repeat biopsy, 148/231 (64%) and 56/83 (67.5%) had clinically localized disease, respectively, and were offered radical prostatectomy. 10/148 (6.7%) and 3/56 (5.3%), respectively, opted for radiation therapy and thus, 138/148 (93.3%) and 53/56 (94.7%), respectively, underwent radical retropubic prostatectomy. There were statistically significant differences with respect to multifocality (P = 0.009) and cancer location (P < 0.001) with cancers on repeat biopsy showing a lower rate of multifocality and a more apico‐dorsal location. In contrast, there were no differences with respect to stage (P = 0.2), Gleason score (P = 0.36), percentage Gleason grade 4/5 (P = 0.1), serum PSA (P = 0.62), and patient age (P = 0.517).CONCLUSIONSAt least 10% of patients with negative prostatic biopsy results will be diagnosed with CaP on repeat biopsy. Despite differences in location and multifocality, pathological and biochemical features of cancers detected on initial and repeat biopsy are similar, suggesting similar biological behavior and thus advocating for a repeat prostate biopsy in case of a negative finding on initial biopsy. Cancers missed on initial biopsy and subsequently detected on repeat biopsy are located in a more apico‐dorsal location. Repeat biopsies should thus be directed to this rather spared area in order to improve cancer detection rates. Prostate 47:111–117, 2001. © 2001 Wiley‐Liss, Inc.
Comparison of prazosin, terazosin and tamsulosin: Functional and binding studies in isolated prostatic and vascular human tissues
Authors: Amadesi Silvia , Varani Katia , Spisani Lorella , Daniele Carlo , Turini Alessandro , Agnello Giovanni , Zamboni Paolo , Borea Pier Andrea , Geppetti Pierangelo 
Published: October 2004

AbstractBACKGROUNDTerazosin and tamsulosin are drugs currently used in the treatment of benign prostatic hypertrophy (BPH). The potency of these two α1 receptor antagonists and that of prazosin to inhibit contractions induced by noradrenaline and the binding of [3H]‐prazosin in human prostate and four different human arterial and venous vessels (saphenous and umbilical veins, renal and mesenteric arteries) was studied.METHODSBy bioassay and binding studies, we examined the receptor affinities of different α1 receptor antagonists in different human tissues.RESULTSpKb of terazosin, tamsulosin, and prazosin obtained in the prostatic tissues (8.15, 9.64, and 8.59, respectively) were not different from those obtained in the umbilical veins (8.07, 9.56, and 8.30, respectively), in the mesenteric artery (8.27, 10.29, and 9.01, respectively), renal artery (8.35, 10.13, and 8.76, respectively) and saphenous vein (7.8, 10.3, and 9.32, respectively). IC50 (nM) of prazosin, terazosin, and tamsulosin obtained from binding studies in membrane preparations from prostate tissue were similar to those from umbilical veins, saphenous vein, and renal artery.CONCLUSIONSAll of the evaluated drugs showed similar selectivity for prostatic vs. vascular tissues. Thus, different clinical profiles of the present drugs should not result from their differential affinity for prostatic versus vascular α1‐adrenoceptors. Prostate 47:231–238, 2001. © 2001 Wiley‐Liss, Inc.