bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Novel Approach to Biodegradable Block Copolymers of ε‐Caprolactone and δ‐Valerolactone Catalyzed by New Aluminum Metal Complexes
Authors: Yang Jing , Jia Lin , Yin Lingzhi , Yu Jianyong , Shi Zhen , Fang Qiang , Cao Amin 
Published: December 2004

AbstractSummary: The chemical preparation of structurally well‐defined biodegradable amphiphilic block copolymers is now of great interest for biomedical applications and the fundamental mimetic study of biomacromolecule self‐assembly. For this purpose, in this study, (R,R)‐N,N′‐bis(3‐tert‐butylsalicylidene)‐1,2‐cyclohexanediamine 2 as a ligand was first synthesized from 1,2‐cyclohexanediamine (DACH) and was allowed to further react with AlMe3, leading to a precursor compound 3. Then, the novel five‐coordinated aluminum metal complexes 4–6 and 7–8 were prepared with good yields of 80–90%, bearing various molar mass monofunctional methoxy‐poly(ethylene glycol) MPEG and difunctional poly(ethylene glycol) PEG as the alkoxy moieties, respectively. By means of nuclear magnetic resonance spectrometry (NMR), mass spectrometry (MALDI‐FTMS) and Fourier Transform infrared spectrometry (FT‐IR), new metal aluminum complexes 4–8 were characterized as having distinct chemical structures. Utilizing the synthesized metal complexes 4–8 as novel coordination polymerization catalytic templates, biodegradable amphiphilic MPEG‐b‐PCL, MPEG‐b‐PVL, PCL‐b‐PEG‐b‐PCL and PVL‐b‐PEG‐b‐PVL were synthesized with good control of the molecular weight distribution via the ring opening polymerization of ε‐caprolactone and δ‐valerolactone monomers at 100 °C in toluene. In addition, the chemical and crystalline structures and the thermal properties of these block biodegradable copolymers were analyzed by means of NMR, gel permeation chromatography (GPC), wide‐angle X‐ray diffraction (WAXD), differential scanning calorimetry (DSC) and thermal gravimetric analysis (TGA). It was found that the melting points and crystallinities of the block copolymers synthesized strongly depended on the molecular structures of the polyether and polyester building blocks. Only one glass transition stage was detected, indicating good chain/segmental miscibility between the hydrophilic MPEG/PEG and hydrophobic PCL/PVL blocks in the non‐crystalline regions. Moreover, TGA analysis exhibited typical two‐step decomposition profiles with the weight‐loss percentages in good agreement with block compositions from NMR calculations.
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Solution Properties and Complexation of Polyampholytes based on N,N‐Dimethyldiallylammonium Chloride and Maleic Acid or Alkyl (Aryl) Derivatives of Maleamic Acids
Authors: Ibraeva Zhanar E. , Hahn Mathias , Jaeger Werner , Bimendina Larisa A. , Kudaibergenov Sarkyt E. 
Published: December 2004

AbstractSummary: Solution properties of alternating polyampholytes based on N,N‐dimethyldiallylammonium chloride and maleic acid as well as N,N‐dimethyldiallylammonium and maleamic acid (butylmaleamic acid, phenylmaleamic acid, 4‐butylphenylmaleamic acid) were studied in aqueous and aqueous‐salt solutions. The isoelectric points (IEP) of the amphoteric macromolecules were determined. It was found that the viscosity of equimolar polyampholyte solutions increases at the IEP with an increase in neutral salt concentration, while polyampholyte solutions having an excess of cationic groups exhibit polyelectrolyte character. The influence of pH, neutral salt, and a water–ethanol mixture on the viscosity of polyampholyte solutions was shown. Formation of interpolyelectrolyte complexes between regular polyampholytes based on N,N‐dimethyldiallylammonium chloride–alkyl (aryl) substituted maleamic acids and poly(acrylic acid), poly(styrene sodium sulfonate), as well as the formation of polyampholyte–sodium lauryl sulfate complexes was studied in aqueous solution by potentiometric, conductimetric, turbidimetric, and viscometric methods. The composition of polyampholyte–polyelectrolyte and polyampholyte–surfactant complexes was determined and the influence of temperature and ionic strength on their behavior was studied.Possible conformational changes of APA‐2 and APA‐3 in water, a water–ethanol mixture, and in ethanol containing 0.15 N KCl.magnified imagePossible conformational changes of APA‐2 and APA‐3 in water, a water–ethanol mixture, and in ethanol containing 0.15 N KCl.
Effects of quenched‐in vacancies on the damping behaviour of Cu–11.9Al–2.5Mn shape memory alloy
Authors: Wang Qingzhou , Han Fusheng , Wang Jinxiang , Wang Qiang 
Published: December 2004

AbstractBy internal friction technique, the behaviour of quenched‐in vacancies and their influence on the martensitic transformation of the Cu–11.9Al–2.5Mn alloy has been studied. It is found that the reverse martensitic transformation temperature Tp follows a non‐monotonous dependence on quenching temperature Tp, of which the presence of a maximum Tp value is attributed to the different vacancy formation energies in the ordered and disordered phases. The background internal friction decreases with increasing ageing time due to migration of vacancies and resultant pinning effect on the phase interfaces and dislocations. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Influence of ridge geometry on lateral mode stability of (Al,In)GaN laser diodes
Authors: Schwarz Ulrich T. , Pindl Markus , Sturm Evi , Furitsch Michael , Leber Andreas , Miller Stephan , Lell Alfred , Härle Volker 
Published: December 2004

AbstractHeight and width of the ridge forming the laser diode waveguide determine threshold current density and lateral mode stability. We measure the optical near‐field of the laser mode and simulate the two–dimensional mode distribution including waveguide losses and optical gain. The simulations show that weak guiding and not current spreading is the major cause for increased threshold current densities in weakly guided laser diodes. The near‐field measurements show fundamental and higher order modes for nominally identical ridge laser diodes. We demonstrate that asymmetric losses in the waveguide bias the lateral mode competition towards higher order modes for an intermediate range of index guiding. This asymmetric damping is specific for (Al,In)GaN laser diodes due to absorption introduced in the p‐waveguide by magnesium doping. This competition of lateral modes can also be seen spectrally as two longitudinal mode combs of different optical gain. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Acute efficacy of a sublingual dose of nifedipine on uterine arterial blood flow: preliminary data in prematurely menopausal women
Authors: Huissoud C. , Hadj S. , Bied‐Damon V. , Benchaïb M. , Salle B. 
Published: December 2004

AbstractObjectivesTo determine whether the calcium blocker nifedipine alters Doppler velocimetry and impedance parameters in the uterine artery in prematurely menopausal women.MethodsUterine artery Doppler examinations were performed transvaginally in seventeen prematurely menopausal women without the use of calcium blocker (T0). Following a 10‐mg sublingual dose of nifedipine patients were subsequently rescanned at successive time intervals (T25= 25, T40= 40, T60= 60 min). PI (normalized (NPI) for heart rate) and maximum, minimum and average velocities of the uterine artery were recorded and waveforms were qualitatively assessed using Goswamy and Steptoe's waveform classification.ResultsQuantitative analysis showed a significant decrease in NPI at T25in the right and left uterine arteries (T0:PI= 2.95 and 3.01; T25:PI= 1.52 and 1.52, respectively; P < 0.001) and until the end of the experiment. Minimum and average blood flow velocities increased strongly (P < 0.001) whereas the maximum velocities did not change significantly (P = 0.12). Qualitative analysis revealed more conspicuous results: eight subjects presented ‘abnormal’ spectra: one was type A (absence of protodiastole), three were type B (absence of telediastole) and four were type O (no diastolic blood flow); all of them recovered type C waveforms (normal spectrum) during the hour following nifedipine administration.ConclusionsNifedipine induces a reversible decrease in NPI and an increase in blood flow velocities in the uterine artery in prematurely menopausal women. These results suggest that nifedipine is a potent uterine arterial vasodilator. Copyright © 2004 ISUOG. Published by John Wiley & Sons, Ltd.
Impact of ultrasound cervical length assessment on duration of hospital stay in the clinical management of threatened preterm labor
Authors: Sanin‐Blair J. , Palacio M. , Delgado J. , Figueras F. , Coll O. , Cabero L. , Cararach V. , Gratacos E. 
Published: December 2004

AbstractObjectiveTo evaluate the impact of ultrasound cervical length measurement on duration of hospital stay in patients admitted for threatened preterm labor.Study designThis was a prospective, comparative study in 294 patients with threatened preterm labor in three hospitalization units (Units A, B and C). In the first phase of the study (observational), cervical length was measured by transvaginal ultrasound, but managing physicians were blinded to the results. In the second phase (interventional), physicians from Unit A remained blinded to cervical length information, but Units B and C incorporated these data into their clinical management protocols. Early discharge was contemplated if the cervix measured 25 mm or more on admission (Unit B) or no changes were observed over 48 h (Unit C). Duration of hospital stay and delivery rates within 7 days and before 37 weeks' gestation were recorded.ResultsHospital stay was significantly reduced in Units B and C in the interventional phase, while no changes were observed in Unit A. Delivery rates within 7 days and before 37 weeks' gestation were similar in the three units during the two stages of the study.ConclusionRoutine use of ultrasound cervical length assessment in patients admitted with threatened preterm labor may reduce the duration of hospital stay without increasing the rate of preterm births. These data should be confirmed by means of an appropriately designed randomized clinical trial. Copyright © 2004 ISUOG. Published by John Wiley & Sons, Ltd.
Assessment of fetal anatomy at the 11–14‐week ultrasound examination
Authors: Souka A. P. , Pilalis A. , Kavalakis Y. , Kosmas Y. , Antsaklis P. , Antsaklis A. 
Published: December 2004

AbstractObjectiveTo assess the feasibility of examining cardiac and non‐cardiac fetal anatomy in a low‐risk population in the setting of the routine 11–14‐week ultrasound scan.MethodsThis was a prospective study of 1144 women with viable, singleton pregnancies at 11–14 weeks of gestation. The ultrasound examination was performed transabdominally and transvaginally and fetal anatomy assessment included visualization of the skull, brain, face, spine, four‐chamber and three‐vessel views of the heart, stomach, abdominal wall, kidneys, bladder and extremities.ResultsComplete examination of the fetal anatomy was achieved in 48% of the fetuses, whereas non‐cardiac anatomy was examined successfully in 86% of the fetuses. The use of the transvaginal approach increased successful examination of the fetal anatomy from 72% to 86% of the fetuses and transvaginal scanning was particularly helpful in examining the face, kidneys and bladder. Non‐cardiac anatomy visualization increased from 65% for fetuses with a crown–rump length of 45–54 mm, to 84%, 93% and 96% for fetuses with a crown–rump length of 55–64 mm, 65–74 mm and more than 74 mm, respectively. In the same groups the four‐chamber view was seen in 67%, 86%, 93% and 97% of fetuses, and the three‐vessel view was seen in 25%, 46%, 58% and 67% of fetuses, respectively. Maternal habitus and crown–rump length were found to be statistically significant contributors to the rate of successful examination of fetal anatomy.ConclusionExamination of fetal anatomy is feasible during the routine 11–14‐week scan. The optimal gestational age for examining both cardiac and non‐cardiac anatomy is from the beginning of the 12th week to the end of the 13th week of gestation. Access to the transvaginal approach is important for completeness of the examination. Copyright © 2004 ISUOG. Published by John Wiley & Sons, Ltd.
Egg size, fertility, hatchability, and chick survivability in captive California condors (Gymnogyps californianus)
Authors: Harvey Nancy C. , Dankovchik Jenine D. , Kuehler Cynthia M. , Levites Tom , Kasielke Susie , Kiff Lloyd , Wallace Michael P. , Mace Michael E. 
Published: December 2004

AbstractCalifornia condors are one of the most endangered species native to the mainland United States and are subject of intense effort regarding captive breeding and reintroduction. We analyzed 20 years of California condor egg records from the wild and from three captive propagation facilities for fertility, hatchability, and chick survivability, along with changes in egg size due to multiple clutching. Overall annual mean percent of fertile eggs was 80.2%, hatchability was 87.3%, and chick survivability to ≥60 days was 95.5%. One egg‐laying site had a significantly lower fertility rate (P ≤ 0.0001) than the other sites, which was probably due to pair incompatibility rather than any physiological factors. Egg volume of the first egg was significantly greater than both the second (t=6.73, P=0.0001) and third egg (t=6.62, P ≤ 0.0001) of the season, while the second egg had a significantly greater volume (t=3.20, P=0.0084) than the third egg. Chicks from the second egg (t=3.24, P=0.029) and third egg (t=7.94, P=0.0014) of the season were significantly smaller than chicks from the first egg of the season. The decrease in egg measures and chick hatch weight due to multiple clutching did not affect hatchability or chick survivability. There were significant positive relationships (P<0.0001) between fresh egg weight and chick hatch weight and between egg volume and chick hatch weight, as well as between fresh egg weight and egg volume. In spite of the decrease in fresh egg weight, egg volume and chick hatch weights, due to egg removal to stimulate double and sometimes triple clutching, the captive propagation program has been successful in producing birds for the restoration of this species. Zoo Biol 23:489–500, 2004. © 2004 Wiley‐Liss, Inc.
Genetic variability and population differentiation in captive baird's Tapirs (Tapirus bairdii)
Authors: Norton James E. , Ashley Mary V. 
Published: December 2004

AbstractThe objectives of this study were to assess the level of genetic variability and population differentiation within captive populations of an endangered large mammal, Baird's tapir (Tapirus bairdii). We genotyped 37 captive animals from North American (NA) and Central American (CA) zoos and conservation ranches using six polymorphic microsatellite loci. Standard indices of genetic variability (allelic richness and diversity, and heterozygosity) were estimated and compared between captive populations, and between captive and wild population samples. In addition, we evaluated levels of population differentiation using Weir and Cockerham's version of Wright's F‐statistics. The results indicate that the NA and CA captive populations of Baird's tapirs have retained levels of genetic variability similar to that measured in a wild population. However, inbreeding coefficients estimated from the molecular data indicate that the CA captive population is at increased risk of losing genetic variability due to inbreeding. Despite this, estimated levels of population differentiation indicate limited divergence of the CA captive population from the wild population. Careful management appears to have kept inbreeding coefficients low in the NA captive population; however, population differentiation levels indicate that the NA population has experienced increased divergence from wild populations due to a founder effect and isolation. Based on these results, we conclude that intermittent exchanges of Baird's tapirs between the NA and CA captive populations will benefit both populations by increasing genetic variability and effective population size, while reducing inbreeding and divergence from wild populations. Zoo Biol 23:521–531, 2004. © 2004 Wiley‐Liss, Inc.
Angiotensin II‐mediated calcium signals and mitogenesis in human prostate stromal cell line hPCPs
Authors: Wennemuth Gunther , Aumüller Gerhard 
Published: December 2004

Western blots and immunocytochemistry were used to detect angiotensin 1 (AT1) and angiotensin 2 (AT2) receptors in human primary cultures of the prostate stromal compartment (hPCPs). Immunohistochemistry was performed on human prostate tissue‐embedded paraffin. In addition, pharmacological tools were applied in combination with photometry experiments to characterize the physiological activity of AT1 and AT2 receptors in hPCPs cell culture. A proliferation assay was used to describe the mitogenic activity of angiotensin II (Ang II) on hPCPs cells.
Only the AT1 receptor was detected in Western blot analysis. Immunocytochemistry of hPCPs cells showed that the AT1 receptor is present in both the smooth muscle type and the fibroblastic type. In the stromal compartment of human prostate tissue, immunoreaction with antibodies against the AT1 receptor was detectable.
Fura‐2‐loaded hPCPs cells showed an instantaneous and linear rise in free intracellular calcium ion concentration ([Ca2+]i) after local perfusion with Ang II in concentrations of 10 nM. Removing of external calcium or emptying intracellular calcium stores before Ang II application diminished or abolished this [Ca2+]i response.
The response to Ang II was also diminished when hPCPs cells were perfused with the AT1 receptor inhibitor losartan prior to Ang II application. No inhibition of the [Ca2+]i increase was detectable after perfusion with PD 123319, a specific inhibitor of the AT2 receptor.
hPCPs cells were stimulated with Ang II in various concentrations over a period of 2 days. The subsequently performed proliferation assay revealed a mitogenic effect of Ang II on hPCPs in concentrations starting at 10 nM. This effect could be inhibited by losartan.

British Journal of Pharmacology (2005) 144, 3–10. doi:10.1038/sj.bjp.0706037
Phosphonium compounds as new and specific inhibitors of bovine serum amine oxidase
Authors: DI PAOLO Maria Luisa , LUNELLI Michele , SCARPA Marina , RIGO Adelio 
Published: December 2004

TPP+ (tetraphenylphosphonium ion) and its analogues were found to act as powerful competitive inhibitors of BSAO (bovine serum amine oxidase). The binding of this new class of inhibitors to BSAO was characterized by kinetic measurements. TPP+ can bind to the BSAO active site by hydrophobic and by coulombian interactions. The binding probably occurs in the region of the ‘cation-binding site’[Di Paolo, Scarpa, Corazza, Stevanato and Rigo (2002) Biophys. J. 83, 2231–2239]. Under physiological conditions, the association constant of TPP+ for this site is higher than 106 M−1, the change of enthalpy being the main free-energy term controlling binding. Analysis of the relationships between substrate structure and extent of inhibition by TPP+ reveals some new molecular features of the BSAO active site.
Cross-talk of anosmin-1, the protein implicated in X-linked Kallmann's syndrome, with heparan sulphate and urokinase-type plasminogen activator
Authors: HU Youli , GONZÁLEZ-MARTÍNEZ David , KIM Soo-Hyun , BOULOUX Pierre Marc Gilles 
Published: December 2004

Defective function of anosmin-1, the protein encoded by KAL-1, underlies X-linked Kallmann's syndrome (X-KS), a human hereditary developmental disorder. Anosmin-1 appears to play a role in neurite outgrowth and axon branching, although molecular mechanisms of its action are still unknown. Anosmin-1 contains a WAP (whey acidic protein-like) domain and four contiguous FnIII (fibronectin-like type III) repeats; its WAP domain shows similarity to known serine protease inhibitors, whereas the FnIII domains contain HS (heparan sulphate)-binding sequences. To investigate the functional role of these domains, we have generated both wild-type and mutant recombinant anosmin-1 proteins using a Drosophila S2 cell expression system. Here we present the first biochemical evidence demonstrating the high-binding affinity between HS and anosmin-1, as measured by SPR (surface plasmon resonance) (Kd=2 nM). The FnIII domains, particularly the first, are essential for dose-dependent HS binding and HS-mediated cell surface association. Furthermore, we have identified uPA (urokinase-type plasminogen activator) as an anosmin-1 interactant. Anosmin-1 significantly enhances the amidolytic activity of uPA in vitro; and anosmin-1–HS–uPA co-operation induces cell proliferation in the PC-3 prostate carcinoma cell line. Both the HS interaction and an intact WAP domain are required for the mitogenic activity of anosmin-1. These effects appear to be mediated by a direct protein interaction between anosmin-1 and uPA, since anosmin-1–uPA could be co-immunoprecipitated from PC-3 cell lysates, and their direct binding with high affinity (Kd=6.91 nM) was demonstrated by SPR. We thus propose that anosmin-1 may modulate the catalytic activity of uPA and its signalling pathway, whereas HS determines cell surface localization of the anosmin-1–uPA complex.
Larger capsules enhance short‐range spore dispersal inSphagnum, but what happens further away?
Authors: Sundberg Sebastian 
Published: December 2004

I made a dispersal experiment with sixSphagnum(peat moss) species, representing a wide range of spore and capsule sizes. Spore deposition was recorded at nine distances up to 3.2 m during two four‐day periods with sunny conditions in July and August.Deposition patterns in all species fitted well to the inverse power law (deposition per unit area proportional to distanceb), with rates of decline b ranging from −1.84 to −2.35 among species (R2>0.99). However, even when these curves are extended to infinity for the four species with b<−2, they fail to explain all spores being dispersed (e.g. only 11% inS. squarrosum). Difference in rates of decline b between the periods, despite similar horizontal wind speeds and directions, indicates the importance of thermal updrafts. Spore capsule diameter negatively correlated with the proportions of spores remaining in dehisced capsules (range 5–16%), being deposited within the colony (range 2–14%), and being deposited between the colony edge and the outer sampled perimeter (range 7–22%), probably because a larger capsule shoots the spores higher into the air, in effect meaning an increased initial release height. Spore diameter positively affected deposition outside the colony edge. The deposition curves together with observed long‐distance colonisations, omnipresence in mires of manySphagnumspecies and genetic evidence, suggest thatSphagnumspores regularly travel far.Spatial extension of the empirical deposition curves at a regional scale indicate that with increasing isolation of target sites, the higher the proportion of spores would originate from sources farther away than the nearest sources. Given spatial patterns in the source populations, this would result in higher genetic (and species) diversity per coloniser with increasing isolation, thus counteracting differentiation.