bluuebunny/crossref_metadata_2025_split huggingface dataset:
A novel route for the synthesis of poly(2‐hydroxyethyl methacrylate) grafted TiO2 nanoparticles via surface thiol‐lactam initiated radical polymerization
Authors: Bach Long Giang , Islam Md. Rafiqul , Seo Sung Yong , Lim Kwon Taek 
Published: May 2012

AbstractHybrid nanocomposites of poly(2‐hydroxyethyl methacrylate) (PHEMA) and TiO2 nanoparticles were synthesized via surface thiol‐lactam initiated radical polymerization by following the grafting from strategy. Initially, TiO2 nanoparticles were modified by 3‐mercaptopropyl trimethoxysilane to prepare thiol functionalized TiO2 nanoparticles (TiO2SH). Subsequently, surface initiated polymerization of 2‐hydroxyethyl methacrylate was conducted by using TiO2SH and butyrolactam as an initiating system. The anchoring of PHEMA onto the surface of TiO2 nanoparticles was investigated by FTIR, 1H‐NMR, XPS, TGA, and XRD analyses. The experimental results indicated a strong interaction between PHEMA and TiO2 nanoparticles owing to covalent bonding. The TEM and SEM images of PHEMA‐g‐TiO2 showed that the agglomeration propensity of TiO2 nanoparticles was significantly reduced upon the PHEMA functionalization. The molecular weight and polydispersity index of the cleaved PHEMA from the surface of TiO2 nanocomposites were estimated by GPC analysis. An improved thermal property of the nanocomposites was observed from TGA analysis. PHEMA‐g‐TiO2 nanocomposites were found to be highly dispersible in organic solvents. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Hemocompatibility evaluation of polyurethane film with surface‐grafted poly(ethylene glycol) and carboxymethyl‐chitosan
Authors: Ren Zhenchu , Chen Guangyi , Wei Zhiyong , Sang Lin , Qi Min 
Published: May 2012

AbstractTo improve the hemocompatibility and biocompatibility of polyurethanes (PUs), PU surface was firstly modified by poly(ethylene glycol) PEG through acryloyl chloride and subsequently grafted on carboxymethyl‐chitosan (CMCS). Attenuated total reflection Fourier transform infrared spectroscopy and X‐ray photoelectron spectroscopy analysis confirmed that carboxyl‐chitosan was grafted onto PUs surface. The surface properties of unmodified and modified PU films were determined and compared by water contact angle assessment. After PEG and CMCS grafting, the surface energy of the PU film was increased. Furthermore, the hemocompatibility of the modified PU films was systematically evaluated by bovine serum albumin (BSA) adsorption, the dynamic blood clotting test, the platelet adhesion test, and the hemolytic test. It appears that BSA adsorption and platelet adhesion were significantly curtailed for the modified PU films. Therefore, the obtained results showed the modified PU film has better hemocompatibility. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Grafting of maleic anhydride onto an ethylene‐propylene‐diene terpolymer and concurrent organoclay nanocomposite preparation in solution and melt
Authors: Krajnc Matjaž , Karger‐Kocsis József , Šebenik Urška 
Published: May 2012

AbstractThe possibility of simultaneous peroxide‐initiated grafting of MAH (maleic anhydride) onto EPDM (ethylene‐propylene‐diene terpolymer) and EPDM/clay nanocomposite synthesis by the solution and melt process is investigated. Montmorillonite organoclay is used. Maleation efficiency is investigated by infrared spectroscopy. Clay exfoliation and the resulting nanocomposite properties are determined by X‐ray diffraction and dynamic mechanical analysis, respectively. Simultaneous grafting and exfoliated nanocomposite synthesis can be carried out in solution and melt. The use of optimal amounts of initiator and MAH is very important. High peroxide initiator concentration causes extensive EPDM crosslinking and scission reactions. High concentration of MAH deteriorates clay exfoliation in melt because of reduced shearing due to MAH addition. The use of low MAH concentration is a straightforward solution if the extent of MAH grafting onto EPDM is not considerably impaired. To overcome this problem, a two step melt compounding process is suggested and tried out. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Covalent immobilization of α‐amylase onto thermally crosslinked electrospun PVA/PAA nanofibrous hybrid membranes
Authors: Baştürk Emre , Demir Serap , Danış Özkan , Kahraman Memet Vezir 
Published: May 2012

AbstractPoly(vinyl alcohol)/poly(acrylic acid) (PVA/PAA) nanofibers with the fiber diameter of 100–150 nanometers were fabricated by electrospinning. PVA/PAA nanofibers were crosslinked by heat‐induced esterification and resulting nanofiber mats insoluble in water. α‐Amylase was covalently immobilized onto the PVA/PAA nanofiber surfaces via the activation of amine groups in the presence of 1,1′‐carbonyldiimidazole. The immobilized α‐amylase has more resistance to temperature inactivation than that of the free form and showed maximum activity at 50°C. pH‐dependent activities of the free and immobilized enzymes were also investigated, and it was found that the pH of maximum activity for the free enzyme was 6.5, while for the optimal pH of the immobilized enzyme was 6.0. Reuse studies demonstrated that the immobilized enzyme could reuse 15 times while retaining 81.7% of its activity. Free enzyme lost its activity completely within 15 days. Immobilized enzyme lost only 17.1% of its activity in 30 days. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Habitat use by a freshwater dolphin in the low‐water season
Authors: Braulik Gill T. , Reichert Albert P. , Ehsan Tahir , Khan Samiullah , Northridge Simon P. , Alexander Jason S. , Garstang Richard 
Published: May 2012

ABSTRACT

Many river dolphin populations are most vulnerable during the low‐water season when habitat is limited. Indus River dolphin habitat selection in the dry season was investigated using Generalized Linear Models of dolphin distribution and abundance in relation to physical features of river geomorphology and channel geometry in cross‐section.
Dolphins selected locations in the river with significantly greater mean depth, maximum depth, cross‐sectional area, and hydraulic radius, and significantly narrower river width and a lower degree of braiding than areas where dolphins were absent. They were also recorded with higher frequency at river constrictions and at confluences.
Channel cross‐sectional area was the most important factor affecting dolphin presence and abundance, with the area of water below 1 m in depth exerting the greatest influence. Indus dolphins avoided channels with small cross‐sectional area (<700 m2), presumably owing to the risk of entrapment and reduced foraging opportunities.
Channel geometry had a greater ability to explain dolphin distribution than river geomorphology; however, both analyses indicated similar types of habitat selection. The dolphin–habitat relationships identified in the river geomorphology analysis were scale‐dependent, indicating that dolphin distribution is driven by the occurrence of discrete small‐scale features, such as confluences and constrictions, as well as by broader‐scale habitat complexes.
There are numerous plans to impound or extract more water from the Indus River system. If low‐water season flows are allowed to decrease further, the amount of deeper habitat will decline, there may be insufficient patches of suitable habitat to support the dolphin population through the low‐water season, and dolphins may become isolated within deeper river sections, unable or unwilling to traverse through shallows between favourable patches of habitat. Copyright © 2012 John Wiley & Sons, Ltd.
Fostering empathy in undergraduate health science majors through the reconciliation of objectivity and subjectivity: An integrated approach
Authors: Dunbar Robert L. , Nichols Marcia D. 
Published: May 2012

AbstractThe demand for empathetic health care practitioners requires an academic curriculum suited to that need. Here we describe a series of integrated activities that were designed to foster empathy in undergraduate health science majors. By combining content and pedagogical approaches from the humanities and sciences, we asked students to reconcile objective and subjective modes of understanding the human body as a learning object. Preliminary evaluations of student behavior, written student responses, and survey results are offered as support for our conclusion that the integration of a humanities perspective into the Anatomy classroom at University of Minnesota Rochester can facilitate the process of developing student empathy through the reconciliation of objective and subjective modes. Furthermore, students were able to apply this understanding to images on the page or screen, to living human learning objects and human cadavers. Although to claim that these activities in themselves can stymie the stasis/decline of empathy that health science students report would be patently false, we conclude that similar approaches could offer an avenue by which other educators might develop similar activities that, in aggregate, might have a lasting effect from the undergraduate through the graduate level of training in the health sciences. Anat Sci Educ. © 2012 American Association of Anatomists.
Flow‐injection chemiluminescence and electrogenerated chemiluminescence determination of escitalopram oxalate in tablet form
Authors: Alarfaj Nawal A. , Aly Fatma A. , Al‐Qahtany Abeer A. 
Published: May 2012

ABSTRACTRapid, simple and highly sensitive flow‐injection (FI) chemiluminescence (CL) and flow‐injection electrogenerated chemiluminescence (ECL) methods were developed for the determination of escitalopram oxalate (ESC), a selective serotonin reuptake inhibitor used as an antidepressant drug. The CL method was based on the CL reaction of ESC with acidic cerium(IV) and tris(2,2'‐bipyridyl)ruthenium(II) (Ru). Various experimental parameters affecting CL intensity were carefully studied and optimised. The method enabled the determination of 0.001‐50 µg/mL of ESC in bulk form with a correlation coefficient r = 0.9999. The limit of detection (LOD) was 0.01 ng/mL (S/N = 3). The ECL method was based on the ECL reaction of Ru with the drug in an acidic medium, permitting the determination of ESC in the range of 0.00001‐70 µg/mL with r = 0.9999 and LOD of 1 x 10‐4 ng/mL. The proposed methods were applied to the determination of ESC in commercial tablets. The results were compared statistically with those obtained from a published method using t‐ and F‐tests. Copyright © 2012 John Wiley & Sons, Ltd.
Structured intraoperative assessment of pancreatic gland characteristics in predicting complications after pancreaticoduodenectomy
Authors: Ansorge C , Strömmer L , Andrén-Sandberg Å , Lundell L , Herrington M K , Segersvärd R 
Published: May 2012

Abstract

Background
The morbidity rate after pancreaticoduodenectomy remains high (20–50 per cent) and postoperative pancreatic fistula (POPF) is a major underlying factor. POPF has been reported to be associated with pancreatic consistency (PC) and pancreatic duct diameter (PDD). The aim was to quantify the risk of pancreaticojejunostomy-associated morbidity (PJAM) by means of a structured intraoperative assessment of both characteristics.

Methods
This single-centre prospective observational study included pancreaticoduodenectomies performed between 2008 and 2010 with a standardized duct-to-mucosa end-to-side pancreaticojejunostomy. PC and PDD were assessed during surgery and classified into four grades each (from very hard to very soft, and from larger than 4 mm to smaller than 2 mm, respectively). PJAM was defined as POPF (grade B or C in International Study Group on Pancreatic Fistula classification) or symptomatic peripancreatic collection of either abscess or fluid. PJAM of at least Clavien grade IIIb was considered severe.

Results
PJAM and POPF were observed in 24 (21·8 per cent) and 17 (15·5 per cent) of 110 patients respectively. Softer PC and smaller PDD were risk factors for POPF (both P &lt; 0·001), symptomatic peripancreatic collections (P = 0·071 and P = 0·015) and PJAM (both P &lt; 0·001). Combining consistency and duct characteristics in a composite classification the PJAM risk was stratified as ‘high’ (both risk factors, PJAM incidence 51 per cent), ‘intermediate’ (softer PC or smaller PDD, PJAM 26 per cent) or ‘low’ (no risk factors, PJAM 2 per cent). Severe PJAM was observed only in patients with smaller PDD.

Conclusion
A high-risk pancreatic gland had a 25-fold higher risk of PJAM after pancreaticoduoden- ectomy than a low-risk gland. This simple classification can contribute to more individualized patient management and allow stratification of study cohorts with homogeneous POPF risk.
Comparative study on safety, efficacy, and midterm results of balloon mitral valvotomy performed with triple lumen and double lumen mitral valvotomy catheters
Authors: Nair Krishna Kumar Mohanan , Pillai Harikrishnan Sivadasan , Thajudeen Anees , Tharakan Jaganmohan , Titus Thomas , Valaparambil Ajitkumar , Sivasubramonian Sivasankaran , Mahadevan Krishnamoorthy Kavassery , Namboodiri Narayanan , Sasidharan Bijulal , Ganapathi Sanjay 
Published: May 2012

AbstractBackgroundThe triple lumen Inoue balloon is routinely used for Balloon Mitral Valvotomy (BMV) in India. Its major limitation is the high cost. The double lumen Accura balloon is less expensive, making it an attractive alternative in the developing countries. The study was meant to assess the safety, efficacy and midterm results of Accura balloon with respect to the Inoue balloon.Patients and Methods816 consecutive patients, who underwent elective BMV in this Institute from 1997 to 2003, were included in the study. The data of 487 patients who underwent BMV with Accura balloon was compared with 329 patients who underwent BMV with Inoue balloon. The clinical, echocardiographic, and hemodynamic data of these patients were analyzed retrospectively to assess the safety and efficacy of Accura balloon with respect to the Inoue balloon.ResultsImmediate procedural success (93.9% in Inoue group and 91.6% in Accura group p. NS) and complications (6.6% in Inoue group and 5.6% in Accura group p. NS) were comparable between the study groups. The two study population had similar restenosis rate and events at 1 year after BMV. Both balloons could be reused multiple times without compromising on the safety and effectiveness. Accura balloons were less costly than Inoue balloon. The reusability with Accura was slightly more and found to be more cost‐effective.ConclusionsBoth Accura and Inoue balloon mitral valvotomy balloons are effective in providing relief from hemodynamically significant mitral stenosis in terms of gain in valve area and reduction in trans mitral gradient. Both groups have similar procedural success and complication rates, restenosis, and follow‐up events at 1 year. Both balloons could be reused multiple times and Accura balloon is found to be more cost effective. © 2012 Wiley Periodicals Inc.
Hybrid intravascular ultrasound and optical coherence tomography catheter for imaging of coronary atherosclerosis
Authors: Li Brian H. , Leung Annie S.O. , Soong Alan , Munding Chelsea E. , Lee Hyunggyun , Thind Amandeep S. , Munce Nigel R. , Wright Graham A. , Rowsell Corwyn H. , Yang Victor X.D. , Strauss Bradley H. , Stuart Foster F. , Courtney Brian K. 
Published: May 2012

ObjectiveTo demonstrate the feasibility of imaging human coronary atherosclerosis using a novel hybrid intravascular ultrasound (IVUS) and optical coherence tomography (OCT) imaging catheter.BackgroundIVUS and OCT have synergistic advantages and recent studies involving both modalities suggest the use of a hybrid imaging catheter may offer improved guidance of coronary interventions and plaque characterization.MethodsA 1.3 m custom hybrid IVUS‐OCT imaging probe was built within a 4F catheter using a 42 MHz ultrasound transducer and an OCT imaging fiber. Coplanar images were simultaneously acquired ex vivo by both modalities in 31 arterial segments from 11 cadaveric human coronaries. IVUS and OCT images were acquired at 250 μm intervals, of which 13 of the arterial segments were selected as representative of a diverse set of pathological findings. The selected segments were then imaged with either digital X‐ray or micro‐CT, processed for histological analysis and compared with the corresponding IVUS and OCT images.ResultsImages of human coronary atherosclerosis using the hybrid IVUS‐OCT catheter demonstrated a range of vascular pathologies that were confirmed on histology. The anticipated synergistic advantages of each modality were qualitatively apparent, including the deeper tissue penetration of IVUS and the superior contrast, resolution and near‐field image quality of OCT.ConclusionsPreliminary ex vivo images using a hybrid IVUS‐OCT catheter demonstrated feasibility in using the device for intracoronary imaging of atherosclerosis. Future studies will include in vivo imaging and larger samples sizes to enable quantitative comparisons of tissue characterization and feature identification using hybrid imaging catheters versus standalone IVUS and OCT imaging techniques. © 2012 Wiley Periodicals, Inc.
Hemodynamic findings in severe tricuspid regurgitation
Authors: Rao S. , Tate D.A. , Stouffer G.A. 
Published: May 2012

AbstractTricuspid regurgitation (TR) most commonly occurs in response to right ventricular (RV) dilation with structural abnormalities in the tricuspid valve being rarer. In addition to RV size and valvular integrity, the amount of TR is influenced by RV preload and afterload, the respiratory cycle, left heart function and atrial fibrillation. Hemodynamic changes in right atrial (RA) pressures in severe TR include elevated mean pressures, a large systolic wave called an “s” wave, a prominent ‘Y’ descent and a blunted ‘X’ descent. In addition, RV end diastolic pressure is elevated and cardiac output is reduced, especially with exercise. “Ventricularization” of the RA pressure tracing, in which the contour of the RA pressure is similar to, but of lower amplitude than, the contour of the RV pressure is the most specific finding but is found in a minority of patients with severe TR. In summary, alterations in the RA pressure tracing are common in patients with severe TR but specific hemodynamic findings lack sensitivity, which may in part be due to the large effects of RV preload, RV afterload and RA compliance on the amount of TR. © 2012 Wiley Periodicals, Inc.
Impact of aortic valve calcification on the outcome of transcatheter aortic valve implantation: Results from the prospective multicenter German TAVI registry
Authors: Staubach Stephan , Franke Jennifer , Gerckens Ulrich , Schuler Gerhard , Zahn Ralf , Eggebrecht Holger , Hambrecht Rainer , Sack Stefan , Richardt Gert , Horack Martin , Senges Jochen , Steinberg Daniel H. , Ledwoch Jakob , Fichtlscherer Stephan , Doss Mirko , Wunderlich Nina , Sievert Horst ,   German Transcatheter Aortic Valve Implantation—Registry Investigators
Published: May 2012

ObjectivesTranscatheter aortic valve implantation (TAVI) is an emerging technology in patients with severe aortic stenosis.BackgroundWhether the degree of aortic valve calcification impacts the outcome after TAVI has not been thoroughly evaluated.MethodsWe analyzed data from the prospective multicenter German TAVI registry, including 1,365 patients as of July 2010. Patients were divided into three groups, based on the degree of aortic valve calcification: mild (n = 67), moderate (n = 392), and severe (n = 906) valve calcification, determined by visual estimation by the operator.ResultsMean age was 81.7 ± 6.2 years; mean logistic EUROscore was 20.6 ± 13.7%. Patients with severe aortic valve calcification had a higher mean and peak‐to‐peak gradient before the intervention (P < 0.0001). Technical success was achieved in 97%, similar in each group. The Medtronic CoreValve was implanted in 80.8%, the Sapien Edwards prosthesis in the remaining cases. The duration of the procedure and fluoroscopy was higher in the group with severe calcification (P < 0.01 for procedure and P < 0.05 for fluoroscopy).During the periprocedural period there were no differences among the groups regarding in‐hospital death, cerebrovascular events, myocardial infarction, thromboembolic events, aortic dissection, or severe vascular complications. Furthermore, there was no significant difference in postprocedural aortic mean gradient (7.0 mm Hg vs. 5.6 mm Hg vs. 6.3 mm Hg; P = 0.07), in residual aortic regurgitation (74% vs. 72% vs. 68%; P = 0.3) or postprocedure pacemaker implantation (38% vs. 30.4% vs. 34.2%; P = 0.35).During 30‐day follow up there was no difference in regard to the number of death, strokes, and myocardial infarctions.ConclusionsOur results of a real‐world registry suggest that the extent of aortic valve calcification does not influence the success or procedural outcome significantly. © 2012 Wiley Periodicals, Inc.
Tuning the Solid‐State Luminescence of BODIPY Derivatives with Bulky Arylsilyl Groups: Synthesis and Spectroscopic Properties
Authors: Lu Hua , Wang Qiuhong , Gai Lizhi , Li Zhifang , Deng Yuan , Xiao Xuqiong , Lai Guoqiao , Shen Zhen 
Published: May 2012

AbstractBoron dipyrromethenes (BODIPYs) with bulky triphenylsilylphenyl(ethynyl) and triphenylsilylphenyl substituents on pyrrole sites were prepared via Hagihara–Sonogashira and Suzuki–Miyaura cross‐coupling with ethynyl‐terminated tetraphenylsilane and boronic acid‐terminated tetraphenylsilane. The chromophores are designed to prevent intermolecular π–π stacking interaction and enhance fluorescence in the solid state. Single crystals of 1 a and 2 b for X‐ray structural analysis were obtained, and weak π–π stacking interactions of the neighboring BODIPY molecules were observed. Spectroscopic properties of all of the dyes in various solvents and in films were investigated. Triphenylsilylphenyl‐substituted BODIPYs generally show more pronounced increases in solid‐state emission than triphenylsilylphenyl(ethynyl)‐substituted BODIPYs. Although the simple BODIPYs do not exhibit any fluorescence in the solid state (Φ=0), arylsilyl‐substituted BODIPYs exhibit weak to moderate solid‐state fluorescence with quantum yields of 0.03, 0.07, 0.10, and 0.25. The structure–property relationships were analyzed on the basis of X‐ray crystallography, optical spectroscopy, cyclic voltammetry, and theoretical calculations.