bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effectiveness of chromic catgut implantation in men with idiopathic infertility
Authors: Ramos Padilla Kenia 
Published: April 2024

Introduction: the treatment of idiopathic male infertility is empirical and controversial. Objective: to assess the effectiveness of chromic catgut implantation at selected acupuncture points according to traditional Chinese syndromic diagnosis in men with idiopathic infertility. Methods: quasi-experimental study with pre-test-post-test and control group, in 135 patients with idiopathic infertility divided into: study group (67 treated with catgut implantation) and control group (68 treated with medication). A traditional medical history was taken and descriptive and inferential statistics were used. Results: Mean age was similar in both groups (33.90 ± 6.28 years study group and 33.68 ± 5.6 years control group). Patients with Kidney yang vacuum predominated (55.2 % study group and 52.9 % control group). Both groups showed highly significant differences in sperm concentration, motility and morphology before and after treatments and between groups. Clinical improvement (64.2 % vs. 8.8 %), spermogram normalisation (53.7 % vs. 16.2 %) and pregnancy achievement (17.9 % vs. 4.4 %) were higher in patients treated with chromic catgut implantation compared to those using Clomiphene. Conclusions: chromic catgut implantation in selected acupuncture points according to traditional Chinese syndromic diagnosis in men with idiopathic infertility is effective because it improves sperm concentration, motility and morphology, normalises the spermogram and contributes to achieving pregnancies with increased fertility, to a greater extent than treatment with Clomiphene; together with the clinical improvement of the patients
Enhanced Photorefractivity of Poly(N‐vinylcarbazole)‐Based Composites through Electric‐Field Treatments and Ionic Liquid Doping
Authors: Quintana José A. , Villalvilla José M. , Boj Pedro G. , Martín‐Gomis Luis , Ortiz Javier , Fernández‐Lázaro Fernando , Sastre‐Santos Ángela , García María A. Díaz 
Published: January 2009

AbstractIt is shown that the photorefractive (PR) performance of polymer composites based on poly(N‐vinylcarbazole) can be improved when samples are subjected to an electric field for a certain time, i.e. conditioned, previous to the PR characterization. It is also found that for conditioned samples the addition of an organic ionic liquid to the PR composition allows to obtain PR effect without the need of using a sensitizer. The typical electric field treatment time at room temperature and at a field of 20 V µm−1is 20 min. This procedure leads to a decrease of dark conductivity and an increase of photoconductivity, and consequently an increase of conductivity contrast. This results in higher PR two‐beam‐coupling gain coefficients and shorter response times, particularly at low fields. Dependencies of the process dynamics on impurities, applied field strength, temperature and the presence of an organic ionic liquid are examined in detail. It is remarkable the significant increase of the PR gain coefficients, and more drastically of the net gain coefficients, observed at low fields (<55 V µm−1), when an ionic organic liquid such as benzalkonium chloride is added to unsensitized conditioned PR composites. These findings open a new route to improve the PR performance, not only of PVK‐based composites, but also of other types of organic materials, the main advantage being that no sensitizer is needed.
Reactive Intermediates in Oxygenation Reactions with Mononuclear Nonheme Iron Catalysts
Authors: Yoon Jihae , Wilson Samuel A. , Jang Yu Kyeong , Seo Mi Sook , Nehru Kasi , Hedman Britt , Hodgson Keith O. , Bill Eckhard , Solomon Edward I. , Nam Wonwoo 
Published: January 2009

AbstractEine späte Zwischenstufe: Der Nichthäm‐Eisen(IV)‐Oxo‐Komplex [FeIV(O)(bqen)(L)]n+ (bqen=N,N′‐Dimethyl‐N,N′‐bis(8‐chinolyl)ethan‐1,2‐diamin, L=CH3CN oder CF3SO3−) aktiviert die C‐H‐Bindungen von Alkanen und Alkoholen durch Wasserstoffatomabstraktion. Die katalytische Oxidation dieser Spezies soll durch eine bei Oxidationsreaktionen hoch aktive Nichthäm‐Eisen(V)‐Oxo‐Spezies erfolgen (siehe Bild).magnified image
High‐Yielding Synthesis of the Anti‐Influenza Neuramidase Inhibitor (−)‐Oseltamivir by Three “One‐Pot” Operations
Authors: Ishikawa Hayato , Suzuki Takaki , Hayashi Yujiro 
Published: January 2009

AbstractAbkürzungen genommen: Eine bemerkenswert kurze und ergiebige asymmetrische Totalsynthese von (−)‐Oseltamivir beruht auf organokatalytischen Umsetzungen und Dominoreaktionen. Die als Tamiflu bekannte Zielverbindung wird in kurzer Zeit effizient erhalten, und auch Derivate können effektiv synthetisiert werden.magnified image
Sequential Assembly of Phototunable Ferromagnetic Ultrathin Films with Perpendicular Magnetic Anisotropy
Authors: Suda Masayuki , Einaga Yasuaki 
Published: January 2009

AbstractGeordnete Verhältnisse: Assoziate ferromagnetischer FePt‐Nanopartikel mit großer senkrechter magnetischer Anisotropie wurden durch magnetfeldgestützte schichtweise Abscheidung erhalten, und anschließend wurden geschichtete Filme aus L10‐FePt‐Nanopartikeln und organischen Polymeren hergestellt. Diese Filme werden bei der Verwendung photochromer Moleküle als Polymerschichten photodurchstimmbar.magnified image
Dicationic Sulfur Analogues of N‐Heterocyclic Silylenes and Phosphenium Cations
Authors: Martin Caleb D. , Jennings Michael C. , Ferguson Michael J. , Ragogna Paul J. 
Published: January 2009

AbstractS2+ in der Stickstoffzange: Schwefel(II)‐Dikationen lassen sich mithilfe von α‐Diiminen erhalten, die die positive Ladung stabilisieren (siehe Schema; DAB=Diazabutadien, Dipp=2,6‐Diisopropylphenyl, OTf=CF3SO3). Die Bindungssituation entspricht am ehesten der eines N,N‐koordinierten Schwefel(II)‐Dikations; diese Spezies sind die ersten Schwefel‐Strukturmimetika N‐heterocyclischer Silylenverbindungen und Phospheniumkationen.magnified image
Enantioselective Intermolecular Crossed‐Conjugate Additions between Nitroalkenes and α,β‐Enals through a Dual Activation Strategy
Authors: Zhong Cheng , Chen Yunfeng , Petersen Jeffrey L. , Akhmedov Novruz G. , Shi Xiaodong 
Published: January 2009

AbstractDoppelt schön: Die Titelreaktion wurde mithilfe einer Kombination aus Lewis‐Basen‐ und Iminium‐Aktivierung entwickelt (siehe Schema). Sie verläuft mit ausgezeichneten Ausbeuten und ee‐Werten, und die Produkte können zudem mit ausgezeichneter Erhaltung der Konfiguration in Einzelenantiomere eines substituierten Pyrrolidins überführt werden.magnified image
Photoresponsive Cyclodextrin‐Covered Nanocontainers and Their Sol‐Gel Transition Induced by Molecular Recognition
Authors: Park Chiyoung , Lee Kyuho , Kim Chulhee 
Published: January 2009

AbstractSpringing the trap: Cyclodextrin‐covered mesoporous silica nanoparticles with photocleavable linkers exhibit photoinduced release characteristics and a sol–gel transition that is induced by molecular recognition (see picture). Upon exposure to UV light, the guest molecules were released from the pore by removal of the CD “gatekeeper”, which was linked on the surface of the silica nanoparticle through a photocleavable o‐nitrobenzyl ester moiety.magnified image
High‐Yielding Synthesis of the Anti‐Influenza Neuramidase Inhibitor (−)‐Oseltamivir by Three “One‐Pot” Operations
Authors: Ishikawa Hayato , Suzuki Takaki , Hayashi Yujiro 
Published: January 2009

AbstractTaking shortcuts: A remarkably short and high‐yielding asymmetric total synthesis of (−)‐oseltamivir takes advantage of organocatalysis and single‐pot domino operations. The target, known as the drug Tamiflu, is prepared efficiently in a short time, and also its derivatives can be synthesized effectively.magnified image
Sequential Assembly of Phototunable Ferromagnetic Ultrathin Films with Perpendicular Magnetic Anisotropy
Authors: Suda Masayuki , Einaga Yasuaki 
Published: January 2009

AbstractGetting organized: Assemblies of ferromagnetic FePt nanoparticles were generated with large perpendicular magnetic anisotropy by a magnetic‐field‐assisted layer‐by‐layer method, and subsequently layer‐by‐layer films consisting of L10‐FePt nanoparticles and organic polymers were prepared. These films are phototunable when photochromic molecules are used as polymer layers.magnified image
Synthesis and polymerization of novel epoxy compounds having an adamantane ring and evaluation of their heat resistance and transparency
Authors: Maehara Takayuki , Takenaka Junji , Tanaka Kenji , Yamaguchi Masao , Yamamoto Hiromasa , Ohshita Joji 
Published: January 2009

AbstractThree adamantane derivatives substituted by epoxy groups, 1,3‐bis(glycidyloxy)adamantane (2a), 5,7‐dimethyl‐1,3‐bis(glycidyloxy)adamantane (2b), 1,3,5‐tris(glycidyloxy)adamantane (2c), were synthesized from the corresponding adamantanediol or triol in good yields. These three epoxy compounds were polymerized with an acid anhydride, and the heat resistance of the resulting resins was evaluated. The resin prepared from 2c exhibited high heat resistance with the glass transition temperature (Tg) of 208°C and low degree of coloring by heating. The epoxy compounds were also found to be potentially useful as the precursors of high heat‐resistant resins by thermal homopolymerization. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
New polymer syntheses, Part 43: Novel polyamides‐based diarylidenecyclopentanone: Synthesis, characterization, and corrosion inhibition behavior
Authors: Aly Kamal I. , Wahdan Mostafa H. , Hussein Mahmoud A. 
Published: January 2009

AbstractA new interesting class of polyamides containing diarylidenecyclopentanone moiety IIIa–f was synthesized by polycondensation reaction of the new diamino arylidene monomer I with different aliphatic and aromatic diacid chlorides (including adipoyl, sebacoyl, oxaloyl, terephthaloyl, isophthaloyl, biphenyldicarbonyl) and LiCl anhydrous as a catalyst at room temperature in NMP. The model compound II was synthesized by the interaction of one mole of diarylidenecyclopentanone monomer I with two moles of benzoyl chloride in NMP/LiCl at room temperature. The structure of the model compound was confirmed by correct elemental and spectral analyses. The resulting polymers were characterized by elemental and spectral analyses, beside solubility and viscometry measurements. The thermal properties of those polymers were evaluated by TGA, DTG, and DTA measurements and correlated to their structural units. X‐ray analysis showed that polymers having high degree of crystallinity in the region 2θ = 5 − 60°. In addition, the UV‐visible spectra of some selected polymers were measured in DMSO solution and showed absorption bands in the range 260 − 475 nm, due to n − π* and π − π* transition. On the other hand, the corrosion inhibition behavior of selected examples of polyamides was carried out on carbon–steel in 0.5M H2SO4 at 40°C. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Characterization of associating hydrogels of poly(vinyl alcohol) and poly(vinyl pyrrolidone)
Authors: Liu X. , Fussell G. , Marcolongo M. , Lowman A. M. 
Published: January 2009

AbstractIn this study, hydrogels were prepared from blends of poly(vinyl alcohol) (PVA) and poly(vinyl pyrrolidone) (PVP). The miscibility of the polymers was confirmed with differential scanning calorimetry with the appearance of a single glass‐transition temperature. Additionally, a negative Flory–Huggins interaction parameter further verified the interaction between PVA and PVP. We evaluated the stability of the hydrogels by swelling the gels in phosphate‐buffered saline solutions at pH 7.4. With attenuated total reflectance‐Fourier transform infrared spectroscopy, it was determined that, during swelling, PVP dissolved out of the gel over time and the equilibrium gel content of PVP was nearly identical in all of the samples investigated. After the dissolution of PVP, the equilibrium water content of the gels ranged from 64 to 76 wt %. Additionally, rubber elasticity studies were performed to elucidate information about the physically crosslinked network structure. As determined from rubber elasticity experiments, the mesh size of the physically crosslinked hydrogels ranged from 90 to 230 Å. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Effects of alkalization and fiber loading on the mechanical properties and morphology of bamboo fiber composites. II. Resol matrix
Authors: Das Mahuya , Chakraborty Debabrata 
Published: January 2009

AbstractResol resin composites reinforced with alkali‐treated bamboo strips were fabricated with a hand‐lay‐up technique. This study was aimed at the evaluation of the influence of the caustic concentration on the mechanical properties of bamboo‐strip‐reinforced resol composites with a constant 50% loading of the reinforcement. The treatment of bamboo fiber in a solution of sodium hydroxide with increasing concentration percentages resulted in more and more rigid composites; as a result, the strength and modulus values exhibited improvements. The maximum improvement in the properties was possibly achieved with 20% caustic treated reinforcements. An infrared study indicated the formation of aryl alkyl ether with OH groups of cellulose and methylol groups of resol. Beyond 20%, there was degradation in all the strength properties due to the failure of the mechanical properties of the reinforcement itself. A correlation was found to exist between the mechanical properties and the morphology that developed. Another set of composites with variable loadings of 20% alkali treated fiber (40, 50, and 60%) was fabricated, and a 60% fiber loading showed the best mechanical properties. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Synthesis and water absorbency of polyampholytic hydrogels with antibacterial activity
Authors: Li Xiaohong , Dong Qinzheng , He Peixin 
Published: January 2009

AbstractAmphoteric terpolymers of acrylic acid (AA), acrylamide (AM), and N,N′‐dimethyl‐N‐ethylmeth‐acryloxylethylammoniumbromide (DMAEA‐EB) with varied compositions P[AA‐AM‐(DMAEA‐EB)] were synthesized by inverse suspension polymerization. The components of P[AA‐AM‐(DMAEA‐EB)] were verified by FTIR spectroscopy. The water absorption ability and antibacterial activity of the copolymer against Escherichia coli(E. coli) and Staphylococcus hyicus(S. hyicus) suspended in sterilized physiological saline were investigated. The introduction of N+R4 may increase the water absorbency of P[AA‐AM‐(DMAEA‐EB)] in some degree because of the excellent hydrophilicity of N+R4. The AA‐AM‐(DMAEA‐EB) hydrogels exhibited high antibacterial activity against bacteria tested. The process of adsorption between live bacteria cells and resins was at least partially reversible. A peak of antibacterial efficiency existed with increasing contact time. The resin killed 96.6% E. coli organisms and 90.3% S. hyicus organisms, respectively, within 30 min of contact at dosage of 0.1g. The concentration of DMAEA‐EB has a special effect on the antibacterial activity of the polyampholytic hydrogels, which is different from polycation. It was observed that the antibacterial activity of the resin with 2 mol % of DMAEA‐EB is superior to the copolymers tested with other compositions. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Thermal degradation behavior of styrene‐butadiene‐styrene tri‐block copolymer/multiwalled carbon nanotubes composites
Authors: Lu Lan , Yu Haiyang , Wang Shifeng , Zhang Yong 
Published: January 2009

AbstractThe thermal degradation behavior of styrene‐butadiene‐styrene triblock copolymer (SBS) and SBS/multiwalled carbon nanotubes (MWCNTs) composites prepared by solution processing and melt mixing, respectively, was investigated using nonisothermal thermogravimetric analysis (TGA). The kinetic parameters of the activation energy (Ea) for degradation, preexponential factor A, and the reaction order (n) were evaluated by the Flynn‐Wall‐Ozawa, Kissinger, and Coats‐Redfern methods, respectively. Ea increased and n decreased after the incorporation of 3 wt % of MWCNTs into the SBS. The Ea of SBS/MWCNTs composite prepared by melt mixing was higher than that by solution processing, which was attributed to the good dispersion of MWCNTs in SBS and the interactions between MWCNTs and SBS. The gases evolved during thermal degradation at a nitrogen atmosphere were studied by Fourier transform infrared spectroscopy (FTIR) coupled with the TGA. Aliphatic and aromatic CH peaks appeared simultaneously in FTIR spectra, indicating the thermal degradation of SBS proceeds by a random chain scission process. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Sisal chemo‐thermomechanical pulp paper with a strongly hydrophobic surface coating produced by a pentafluorophenyldimethylsilane cold plasma
Authors: Navarro Fernando , Dávalos Florentina , González‐Cruz Ricardo , López‐Dellamary Fernando , Manríquez Ricardo , Turrado José , Ramos Juan 
Published: January 2009

AbstractFluorinated thin layers were created on CTMP sisal and filter paper surfaces by using pentafluorophenyldimethylsilane (PFPDMS) under RF‐plasma conditions. Surface wettability and water absorption of unmodified and modified samples of both materials were evaluated through contact angle and Cobb test techniques, respectively. The mechanical strength and optical properties were also analyzed. The surface functional groups produced were evaluated using X‐ray photoelectron spectroscopy, Electron Spectroscopy for Chemical Analysis (ESCA) and Attenuated Total Reflectance Fourier Transform infrared (ATR FT‐IR) spectroscopy. Surface morphological changes after plasma treatment were evaluated using Scanning Electron Microscopy (SEM) and Atomic Force Microscopy (AFM). PFPDMS‐plasma treatment of sisal CTMP reduced water absorption from more than 400 g (H2O)/m2 to 18 g (H2O)/m2. The contact angle was increased from less than 15° to 119°–134°. Water absorption for untreated filter paper was 220 g (H2O)/m2 and after plasma treatment the value decreased to 13.6 g (H2O)/m2. Water drop contact angle for untreated filter paper was 24°, and after PFPDMS‐plasma treatment it was 134°. Strength properties were slightly reduced in some cases and brightness was reduced in most of the trials, turning to yellow. ATR FT‐IR and ESCA spectroscopy indicated a fluorinated aromatic surface, whereas AFM and SEM showed a smooth surface coating for both sisal and filter paper after PFPDMS‐plasma treatment. A fully coated surface with a very high hydrophobic character was observed. This new property can be attributed to the formation of a crosslinked polymer network of covalently bound PFPDMS‐based units on the paper surface as shown by the presence of CSi, COSi, CCFx, and CF bonds. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Synthesis and characterization of poly(carbonate urethane) networks with shape‐memory properties
Authors: Feng Yakai , Xue Yan , Guo Jintang , Cheng Lei , Jiao Licai , Zhang Yu , Yue Jinlong 
Published: January 2009

AbstractIn this study, a series of shape‐memory polyurethanes were prepared from polycarbonate diol (PCDL) with a molecular weight of 2000, trimethylol propane, and isophorone diisocyanate (IPDI). The properties of crosslinked poly(carbonate urethane) (PCU) networks with various compositions were investigated. The chemical structures and thermal properties were determined with Fourier transform infrared (FTIR) spectroscopy, differential scanning calorimetry, and thermogravimetric analysis. FTIR analysis indicated that PCU had the structures of IPDI and PCDL and the amido formyl ester in polyurethanes. The gel content of PCU showed that PCU could be effectively formed as crosslinked polyurethane networks. The glass‐transition temperatures of the PCU networks increased slightly with decreasing soft‐segment content in the networks. The values of Young's modulus in the networks at 25°C increased with decreasing soft‐segment content, whereas the tensile stress and breaking elongation decreased significantly. PCU showed shape‐memory effects with a high strain fixity rate. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
LnNa8[OC(CH3)3]10(OH) alkoxide clusters: Highly active single‐component catalysts for the homopolymerization and copolymerization of ε‐caprolactone and trimethylene carbonate
Authors: Sheng Hongting , Li Junmei , Yao Yong Zhang Yingming , Shen Qi 
Published: January 2009

AbstractHeterometal alkoxide clusters of lanthanide and sodium, LnNa8[OC(CH3)3]10(OH) [where Ln = Nd (1) or Yb (2)], which were synthesized by the metathesis reaction of LnCl3 with NaOC(CH3)3 and NaOH in a 1 : 10 : 1 molar ratio in high yields and fully characterized including X‐ray analysis for 2, were found to be highly active catalysts in the ring‐opening polymerization of ε‐caprolactone and trimethylene carbonate and their copolymerization. All of the polymers obtained showed a unimodal molecular weight distribution, indicating that 1 and 2 could really be used as single‐component catalysts. The dependence of catalytic activity on the lanthanide metals was observed: Yb < Nd. A coordination–insertion mechanism for the ring‐opening polymerization is proposed. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Characterization and evaluation of supported rac‐dimethylsilylenebis(indenyl)zirconium dichloride on ethylene polymerization
Authors: Franceschini Fernando C. , Tavares Tatiana T. da R. , Bianchini Daniela , Alves Maria do Carmo M. , Ferreira Maria Lujan , dos Santos João H. Z. 
Published: January 2009

Abstractrac‐Dimethylsilylenebis(indenyl)zirconium dichloride was grafted onto commercial methyl aluminoxane modified silica (SMAO) at different loadings (0.1–1.5 wt % Zr/SMAO). Supported catalysts were evaluated in ethylene polymerization with isoprenylaluminum as a cocatalyst. The characterization of two supported catalysts bearing 0.3 and 0.8 wt % Zr/SiO2 by extended X‐ray absorption fine structure indicated that the number and the intensity of the peaks beyond the coordination shell, associated with the next nearest neighbors, depended on the Zr concentration. For the catalyst with a higher Zr content, only one peak (2.8 Å) was observed. The catalyst with 0.3 wt % Zr/SMAO presented two small peaks at 2.8 and 3.8 Å. Polymers produced with the supported catalysts presented lower crystallinity and higher molar mass and polydispersity values in comparison to that produced by the homogeneous one. Gel permeation chromatogram deconvolution suggested the presence of four catalyst sites for the supported systems. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Preparation and characterization of composite membranes of polysulfone and microcrystalline cellulose
Authors: Zhang Liping , Chen Guowei , Tang Huanwei , Cheng Qingzheng , Wang Siqun 
Published: January 2009

AbstractPhysical and chemical modifications of polymeric ultrafiltration membranes are necessary to improve their hydrophilic properties, strength, and other characteristics. Microcrystalline cellulose (MCC) was prepared from cellulose pulp by acid‐catalyzed hydrolysis in the presence of ultrasonic radiation, and the properties of MCC were evaluated. Through the addition of MCC to a polysulfone (PS) membrane solution, a casting solution of a PS/MCC blend was obtained. Subsequently, the ultrafiltration membrane from the blend was further developed in a phase‐inversion process comprising immersion and deposition. The capacity for ultrafiltration was better with increasing MCC content. When the ratio of MCC to PS was 0.3, the pure water flux of the composite membrane reached 234.2 L/m2/h, and the retention of a bovine serum albumin solution (1 g/L) was as high as 93.4%. The membranes were also observed with scanning electron microscopy and atomic force microscopy to study their microstructures. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009