bluuebunny/crossref_metadata_2025 huggingface dataset:
New sulfonated aramide nanoparticles and their copper complexes with anomalous dielectric behavior
Authors: Hassan Hammed H. A. M. , Elhusseiny Amel F. , Sweyllam Amr M. , Linhardt Robert J.
Published: June 2012

We report the preparation of thermally stable spherical sulfonated aramides nanoparticles and their copper(II) complexes. Metal chelation with copper ions furnished polymeric complexes in a 1 : 2 ratio with square planar geometries as judged by their IR, UV, electron spin resonance, and elemental analysis data. The direct‐current electrical conductivities demonstrated the semiconducting nature of the polymeric particles and their copper complexes. Dielectric loss analysis studies showed spectral peaks appearing at characteristic frequencies, which suggested the presence of relaxing dipoles in all of the polymers. All loss peaks were shown on a linear frequency scale and appeared in the range of 1 decade, and no overlap was observed in any of the samples, whereas in the normal polymer's dielectric loss behavior, each peak covered more than 1 decade. Moreover, the peak positions did not change with increasing temperature; this indicated a nonactivated process. The reported dielectric results revealed anomalous behavior, which has not been reported before for such polymeric analogues, as the polarization in these cases was limited by nonthermal forces, and a steady‐state constant polarization was produced by an applied field. A simple method for the formation of a microporous semiconducting thin film of a polymer derived from isophthalic acid and diaminodiphenylsulfone is described. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Surface modification of polyamide and poly(vinylidene fluoride) membranes
Authors: Boulares‐Pender Alya , Thomas Isabell , Prager Andrea , Schulze Agnes
Published: June 2012

Experimental results from the gas‐plasma treatment and electron‐beam irradiation of polyamide (PA) and poly(vinylidene fluoride) (PVDF) membranes to improve their wettability and to evaluate protein adsorption at their surface are presented. The wettability of the membrane surface was determined by contact angle measurements; the analysis of the surface composition was performed by X‐ray photoelectron spectroscopy (XPS). We observed that a reduction in the water contact angle was not always indicative of a reduction in the protein adsorption and, furthermore, that a charge at the surface of the modified membrane seemed to be a major factor in the protein adsorption process. Furthermore, the XPS results shed some light on the modification mechanism of PVDF and PA by electron‐beam irradiation. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Effect of block composition, size and functionality of poly(styrene‐isobutylene‐styrene) copolymers
Authors: Suleiman David , Carreras Gretselle , Soto Yahaira
Published: June 2012

This investigation studied the resulting nanostructure and transport properties of ionic membranes composed of sulfonated copolymers with thermoplastic and elastomeric blocks. Poly(styrene‐isobutylene‐styrene) (SIBS) of different number average molecular weight (Mn) and polystyrene weight fraction were sulfonated to various levels of ion exchange capacity. The solvent‐casted membranes were characterized using several techniques including elemental analysis, Fourier transform infrared spectroscopy‐, thermogravimetric analysis, and small‐angle X‐ray scattering. These techniques were used to evaluate the thermal and physical properties of the membranes, which in turn, allowed for the comparison of resulting morphologies and selectivities. In addition, counter‐ion substitution (Mg+2, Ca+2, Ba+2) was used to crosslink the sulfonated polymers to further influence their selectivity. Vapor permeabilities were measured at 308 K using dimethyl methyl‐phosphonate, a chemical compound similar to Sarin Gas, and water, to evaluate the selectivity of the membranes and their potential application for chemical and biological protective clothing. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Doping control analysis of desmopressin in human urine by LC‐ESI‐MS/MS after urine delipidation
Authors: Esposito Simone , Deventer Koen , T'Sjoen Guy , Vantilborgh Anna , Van Eenoo Peter
Published: June 2012

The World Anti‐Doping Agency (WADA) has recently added desmopressin, a synthetic analogue of the endogenous peptide hormone arginine vasopressin, to the Prohibited List, owing to the potential masking effects of this drug on hematic parameters useful to detect blood doping. A qualitative method for detection of desmopressin in human urine by high‐performance liquid chromatography–electrospray tandem mass spectrometry (LC‐ESI‐MS/MS) has been developed and validated. Desmopressin purification from urine was achieved by means of delipidation with a 60:40 di‐isopropyl ether/n‐butanol and solid‐phase extraction with WCX cartridges. The lower limit of detection was 25 pg/mL. Extraction recovery was determined as 59.3% (SD 29.4), and signal reduction owing to ion suppression was estimated to be 42.7% (SD 12.9). The applicability of the method was proven by the analysis of real urine samples obtained after intravenous, oral and intranasal administration of desmopressin, achieving unambiguous detection of the peptide in all the cases. Copyright © 2012 John Wiley & Sons, Ltd.
A reappraisal of adult abdominal surface anatomy
Authors: Ali Mirjalili S. , McFadden Sara L. , Buckenham Tim , Stringer Mark D.
Published: June 2012

Descriptions of clinically important surface landmarks often vary between and within contemporary anatomical texts. The aim of this study was to investigate the surface anatomy of major abdominal vessels, kidneys, spleen, gastroesophageal junction, and duodenojejunal flexure in living adults using computed tomography (CT). After excluding patients with distorting space‐occupying lesions, scoliosis, abnormal lordosis, and obvious visceromegaly, 108 abdominal CT scans of supine adults (mean age 60 years, range 18–97 years; 64 female) at end tidal inspiration were available for analysis by dual consensus reporting. Intra‐observer agreement was assessed by repeat blind assessment of a random sample of scans. The vertebral level of the aortic bifurcation and almost all of its major branches, and the origin of the inferior vena cava were consistent with current descriptions. Important differences from contemporary descriptions of surface anatomy were as follows: the renal arteries were most commonly at the L1 vertebral level (left 55%, right 43%); the midpoint of the renal hila was most frequently at L2 (left 68%, right 40%); the 11th rib was a posterior relation of the left kidney in only 28% of scans; and the spleen was most frequently located between the 10th and 12th ribs (48%) with its long axis in line with the 11th rib (55%). Although the majority of vascular surface landmarks are consistent with standard descriptions, the surface anatomy of the kidneys, renal arteries, and spleen needs to be revised in accordance with observations using modern imaging techniques in vivo. Clin. Anat. 25:844–850, 2012.© 2012 Wiley Periodicals, Inc.
Percutaneous mitral valve repair with the mitraclip® system
Authors: Paranskaya Liliya , D'Ancona Giuseppe , Bozdag‐Turan Ilkay , Akin Ibrahim , Kische Stephan , Turan Gökmen R. , Divchev Dimitar , Rehders Tim , Westphal Bernd , Schubert Jochen , Nienaber Christoph A. , Ince Hüseyin
Published: June 2012

Objectives: The purpose of this study was to compare outcomes using standard clipping (SC) (one to two clips) or multiple clipping (MC) (more than two clips). Background: MitraClip® implantation using MC has been proposed to treat severe mitral regurgitation (MR) in high‐risk patients. Methods and Results: A tailored strategy was used implanting as many clips as required to eliminate MR. A total of 85 consecutive patients [78 ± 6 years, 48 men (56.5%) ] with MR (grade 3+ or 4+) were included. EuroSCORE was 24 ± 12 (2.5–56.3) and STS‐score 12 ± 7 (1.2–31.2). SC was used in 61 (71.8%) and MC in 24 (28.2%) patients. Patients in MC group had larger mitral valve (MV) annuli (P = 0.025), MV orifice areas (MVOA) (P = 0.01), and MR degree (P = 0.005). Successful clip placement was achieved in 82 patients (96.5%). At discharge, no patient had grade 4+ MR. MR 3+ presented in 4 patients (7.0%) in the SC group and in 1 (4.5%) in the MC group (P = 0.72). There were 3 (3.5%) in‐hospital deaths. Follow up (211 ± 173 days, range 4–652) echocardiography confirmed similar MVOA (P = 0.83) and MV gradients (P = 0.54) in the both groups. At linear regression there was no independent correlation between clips number and postoperative MVOA/gradient. One‐year survival was 71.1% without difference between groups (P = 0.74). Conclusion: Although the hemodynamic and anatomical basis of MR may differ, every procedure should aim at eliminating MR. In some patients this goal can be achieved using MC with minimized risk of MV stenosis if preoperative anatomy/mechanism of MV regurgitation are adequately assessed. © 2012 Wiley Periodicals, Inc.
Chronic total occlusions: Successful recanalization of very old lesions
Authors: Murarka Shishir , Heuser Richard R.
Published: June 2012

Purpose

The treatment of chronic total occlusion is thought to be the final frontier in treating coronary artery disease nonsurgically. In the past, an old occlusion was not likely to be treated successfully percutaneous. We have had success in revascularizing some very old 20 plus year old occlusions percutaneously.

Methods

Six patients were treated who had >20‐year‐old occlusions. Five patients were male; mean age of patients was 72.2 years (range 63–86). Mean age of the occlusion was 24.8 years. All patients had ischemia in the corresponding territory. Four of the patients had right coronary artery occlusions; one had a left circumflex occlusion and one had left anterior descending artery occlusion.

Results

Using a combination of radial and/or femoral approach, we successfully recanalized all of these old occlusions. No patients had major adverse cardiac events. Two patients developed restenosis at follow‐up that was subsequently treated uneventfully. All the patients had a complete relief of angina.

Conclusion

In a small single center experience, even very old occlusions >20‐year old can be effectively treated with dedicated systems, excellent guiding catheter support and experienced physicians. © 2012 Wiley Periodicals, Inc.
Prognostic value of creatine kinase‐myocardial band isoenzyme elevation following percutaneous coronary intervention: A meta‐analysis
Authors: Jang Jae‐Sik , Jin Han‐Young , Seo Jeong‐Sook , Yang Tae‐Hyun , Kim Dae‐Kyeong , Kim Dong‐Soo , Cho Kyoung‐Im , Kim Bo‐Hyun , Je Hyung‐Gon , Park Yong Hyun
Published: June 2012

Objectives

To assess whether different degrees of creatine kinase‐myocardial band isoenzyme (CK‐MB) elevation after percutaneous coronary intervention (PCI) affect the subsequent risk of death.

Background

While there is consensus that extensive cardiac enzyme elevation increase mortality significantly, there is uncertainty about the exact clinical impact of smaller CK‐MB elevations after PCI.

Methods

The published literature was scanned by formal searches of electronic databases such as PubMed and MEDLINE from January 1999 to October 2011. Risk ratio (RR) was used as summary estimate.

Results

Ten studies have been included totaling 48,022 patients who underwent PCI (12,246 patients with CK‐MB elevation and 35,776 patients without CK‐MB elevation). Mean followup duration for each study ranged from 6 to 48 months. CK‐MB elevation >1× the upper limit of normal (ULN) conferred a significant increase in the risk of mortality with an overall RR of 1.74 (95% confidence interval [CI], 1.42 to 2.13, P < 0.001). Compared with patients without CK‐MB elevation, there was a dose‐response relationship with RR for death being 1.48 (95% CI, 1.25–1.77, P < 0.001) with CK‐MB elevation 1 to <3× ULN, 1.71 (95% CI, 1.23–2.37, P = 0.001) with CK‐MB elevation 3 to 5× ULN, and 2.83 (95% CI, 1.98–4.04, P < 0.001) with CK‐MB elevation ≥ 5× ULN.

Conclusions

Even a small increase in CK‐MB levels after PCI is associated with significantly higher risk of late mortality. Monitoring cardiac enzymes after PCI may help predict the long term clinical outcome. © 2012 Wiley Periodicals, Inc.
First‐in‐man transfemoral transcatheter aortic valve replacement with the 29 mm Edwards SAPIEN XT Valve
Authors: Freeman Melanie , Rodés‐Cabau Josep , Urena Marina , DeLarochelliere Robert , Dumont Eric , Masson Jean‐Bernard , Willson Alexander B. , Binder Ronald K. , Toggweiler Stefan , Leipsic Jonathon , Wood David A. , Webb John G.
Published: June 2012

Objectives

To demonstrate the feasibility of transfemoral transcatheter aortic valve replacement (TAVR) with the 29 mm Edwards SAPIEN XT valve and Novaflex™ + delivery system through a 20F expandable sheath (eSheath™, Edwards Lifesciences, USA). In addition, to describe the use of the Novaflex + delivery system and expandable sheath.

Background

TAVR has undergone significant advances in device technology resulting in smaller profile sheaths and delivery systems, allowing transfemoral delivery of a 29 mm valve.

Methods

Twelve patients underwent transfemoral TAVR with the 29 mm Edwards SAPIEN XT valve and Novaflex + delivery system through a 20F expandable sheath. Baseline clinical and procedural characteristics are evaluated. In‐hospital and 30‐day outcomes are reported according to Valve Academic Research Consortium criteria.

Results

All patients were male with a mean aortic annulus diameter of 25.0 ± 1.1 mm and 25.9 ± 1.2 mm, on transesophageal echocardiography and multidetector computerized tomography, respectively. Mean iliofemoral minimal luminal diameter (MLD) was 8.0 ± 0.8 mm. Successful deployment of the valve occurred in 11 out of 12 patients. Valve embolization occurred in one patient. Aortic valve area increased from 0.7 ± 0.2 to 2.0 ± 0.5 cm2 (P < 0.001). There were two major vascular complications; however, there were no in‐hospital or 30‐day neurological events, need for pacemaker insertion, or mortality.

Conclusions

Transfemoral TAVR with the 29 mm Edwards SAPIEN XT valve and Novaflex + delivery system through a 20F expandable sheath was feasible with acceptable short‐term outcomes. © 2012 Wiley Periodicals, Inc.
Ambulatory transradial percutaneous coronary intervention: A safe, effective, and cost‐saving strategy
Authors: Le Corvoisier Philippe , Gellen Barnabas , Lesault Pierre‐François , Cohen Remy , Champagne Stéphane , Duval Anne‐Marie , Montalescot Gilles , Elhadad Simon , Montagne Olivier , Durand‐Zaleski Isabelle , Dubois‐Randé Jean‐Luc , Teiger Emmanuel
Published: June 2012

Objectives: The aim of this prospective, multicenter study was to assess the safety, feasibility, acceptance, and cost of ambulatory transradial percutaneous coronary intervention (PCI) under the conditions of everyday practice. Background: Major advances in PCI techniques have considerably reduced the incidence of post‐procedure complications. However, overnight admission still constitutes the standard of care in most interventional cardiology centers. Methods: Eligibility for ambulatory management was assessed in 370 patients with stable angina referred to three high‐volume angioplasty centers. On the basis of pre‐specified clinical and PCI‐linked criteria, 220 patients were selected for ambulatory PCI. Results: The study population included a substantial proportion of patients with complex procedures: 115 (52.3%) patients with multivessel coronary artery disease, 50 (22.7%) patients with multilesion procedures, and 60 (21.5%) bifurcation lesions. After 4‐6 hr observation period, 213 of the 220 patients (96.8%) were cleared for discharge. The remaining seven (3.2%) patients were kept overnight for unstable angina (n = 1), atypical chest discomfort (n = 2), puncture site hematoma (n = 1), or non‐cardiovascular reasons (n = 3). Within 24 hr after discharge, no patients experienced readmission, stent occlusion, recurrent ischemia, or local complications. Furthermore, 99% of patients were satisfied with ambulatory management and 85% reported no anxiety. The average non‐procedural cost was lower for ambulatory PCI than conventional PCI (1,230 ± 98 Euros vs. 2,304 ± 1814 Euros, P < 10−6). Conclusions: Ambulatory PCI in patients with stable coronary artery disease is safe, effective, and well accepted by the patients. It may both significantly reduce costs and optimize hospital resource utilization. © 2012 Wiley Periodicals, Inc.
Analysis of Why Boron Avoids sp2 Hybridization and Classical Structures in the BnHn+2 Series
Authors: Osorio Edison , Olson Jared K. , Tiznado William , Boldyrev Alexander I.
Published: June 2012

We performed global minimum searches for the BnHn+2 (n=2‐5) series and found that classical structures composed of 2c–2e BH and BB bonds become progressively less stable along the series. Relative energies increase from 2.9 kcal mol−1 in B2H4 to 62.3 kcal mol−1 in B5H7. We believe this occurs because boron atoms in the studied molecules are trying to avoid sp2 hybridization and trigonal structure at the boron atoms, as in that case one 2p‐AO is empty, which is highly unfavorable. This affinity of boron to have some electron density on all 2p‐AOs and avoiding having one 2p‐AO empty is a main reason why classical structures are not the most stable configurations and why multicenter bonding is so important for the studied boron–hydride clusters as well as for pure boron clusters and boron compounds in general.
Synthesis of Multifunctional Ag@Au@Phenol Formaldehyde Resin Particles Loaded with Folic Acids for Photothermal Therapy
Authors: Yang Ping , Xu Qi‐Zhi , Jin Sheng‐Yu , Lu Yang , Zhao Yang , Yu Shu‐Hong
Published: June 2012

Multifunctional Ag@Au@ phenol formaldehyde resin (PFR) particles loaded with folic acids (FA) have been designed for killing tumor cells through photothermy conversion under the irradiation of near‐infrared (NIR) light. Possessing the virtue of good fluorescence, low toxicity, and good targeting, the nanocomposite consists of an Ag core, an Au layer, a PFR shell, and folic acids on the PFR shell. The Ag@PFR core–shell structure can be prepared with a simple hydrothermal method after preheating. We then filled the PFR shell with a layer of Au by heating and modified the shell with polyelectrolyte to change its surface charge state. To capture tumor cells actively, FA molecules were attached onto the surface of the Ag@Au@PFR particles in the presence of 1‐ethyl‐3‐(3‐dimethly aminopropyl) carbodiimide (EDAC) and N‐hydroxysuccinimide (NHS). Owing to the excellent property of Au NPs and Ag NPs as photothermal conversion agents, the Ag@Au@ PFR@FA particles can be utilized to kill tumor cells when exposed to NIR light.
Diagnosekompetenz durch informelle Lernarrangements?
Authors: Groß Katharina , Reiners Christiane S.
Published: June 2012

Die Fähigkeit von Lehrerinnen und Lehrern zu einer angemessenen Diagnose stellt einen bedeutenden Aspekt der Lehrerkompetenz dar. Um diese zu entwickeln, bietet sich nicht nur der Weg über die Ermittlung von Lernvoraussetzungen der Schüler an, sondern auch ein Weg über die Lernschwierigkeiten an. Eine besondere (Teilnehmer‐)Gruppe stellt der 1999 vom Kölner Modell ins Leben gerufene Experimentalwettbewerb Chemie entdecken dar, der für Schüler der Sekundarstufe I in Nordrhein‐Westfalen konzipiert wurde. Bis heute verzeichnet der Wettbewerb insgesamt über 80 000 Teilnehmer von Gymnasien, Gesamt‐, Real‐ und Hauptschulen. Allerdings zeigt ein Blick in die Statistik, dass die Hauptschulen mit nur etwa 1 % und die Gesamtschulen mit nur 6 % der Gesamtteilnehmerzahl unterrepräsentiert sind. Der vorliegende Beitrag stellt eine Untersuchung vor, in der (Lern‐)Schwierigkeiten von Schülern, die zu einer Nicht‐Teilnahme an dem Experimentalwettbewerb führen, explorativ erhoben wurden.

Im Folgenden wird aus rein pragmatischen Gründen der Lesbarkeit für Lehrerinnen und Lehrer die männliche Sprachform „Lehrer“ und für Schülerinnen und Schüler die männliche Sprachform „Schüler“ verwendet.
„Wie ein Forscher sein“
Authors: Sommer Katrin , Kakoschke Annette , Schindler Simone , Buchwald Mara , Russek Adrian , Schäfer Alexander , Steff Henning , Krupp Ute
Published: June 2012

„Forscherwelt“ ist eine von Henkel ins Leben gerufene Bildungsinitiative, die besonders Kinder im Grundschulalter für Naturwissenschaften begeistern will. In dem außerschulischen Lernort am Henkel‐Standort Düsseldorf experimentieren die Kinder zu Themen wie Kleben, Waschen oder Körperpflege und gewinnen – unterstützt von den Experten vor Ort – einen authentischen Einblick in das echte Forschungsgeschehen. Wissenschaftliche Grundlage des didaktischen Konzeptes der Forscherwelt bildet das Konstrukt der naturwissenschaftlichen Grundbildung. Dabei zielt das didaktische Konzept auf folgende Elemente eines naturwissenschaftlichen Forschungsprozesses ab: Wissenschaftliche Methoden und kritisches Nachprüfen, Analyse und Interpretation von Daten, Wissenschaft und Fragen sowie Kreativität. Das Beispiel des fünftägigen Ferienkurses zum Thema Kleben zeigt, wie die Merkmale des didaktischen Konzeptes die Gestaltung der einzelnen Projekttage prägen.
The role of clinicians in determining radioactive iodine use for low‐risk thyroid cancer
Authors: Haymart Megan R. , Banerjee Mousumi , Yang Di , Stewart Andrew K. , Koenig Ronald J. , Griggs Jennifer J.
Published: June 2012

BACKGROUND:

There is controversy regarding the optimal management of thyroid cancer. The proportion of patients with low‐risk thyroid cancer who received radioactive iodine (RAI) treatment increased over the last 20 years, and little is known about the role played by clinicians in hospital‐level RAI use for low‐risk disease.

METHODS:

Thyroid surgeons affiliated with 368 hospitals that had Commission on Cancer‐accredited cancer programs were surveyed. Survey data were linked to data reported to the National Cancer Database. A multivariable analysis was used to assess the relation between clinician decision makers and hospital‐level RAI use after total thyroidectomy in patients with stage I, well differentiated thyroid cancer.

RESULTS:

The survey response rate was 70% (560 of 804 surgeons). The surgeon was identified as the primary decision maker by 16% of the surgeons; the endocrinologist was identified as the primary decision maker by 69%, and a nuclear medicine, radiologist, or other physician was identified as the primary decision maker by 15%. In a multivariable analysis controlling for hospital case volume and hospital type, when the primary decision maker was in a specialty other than endocrinology or surgery, there was greater use of RAI at the hospital (P < .001). A greater number of providers at the hospital where RAI was administered and having access to a tumor board also were associated with increased use of RAI (P < .001 and P = .006, respectively).

CONCLUSIONS:

The specialty of the primary decision maker, the number of providers administering RAI, and having access to a tumor board were associated significantly with the use of RAI for stage I thyroid cancer. The findings have implications for addressing nonclinical variation between hospitals, with a marked heterogeneity in decision making suggesting that standardization of care will be challenging. Cancer 2013. © 2012 American Cancer Society.
A DOF‐based dynamic spectrum auction algorithm in cognitive femtocell
Authors: Wu Guangen , Ren Pinyi , Du Qinghe , Zhang Chao
Published: June 2012

Dynamic spectrum auction (DSA) has been considered as one of potential spectrum allocation approaches in cognitive femtocell networks. As a modified version of traditional spectrum auction, DSA should not only increase auction revenue but also improve spectrum utilization on finer time granularity. We propose a DSA algorithm based on a double optimization framework (DOF), which focuses on the optimization of auction revenue and spectrum utilization. The optimization processing consists of two stages. Firstly, a proper auction period is selected to balance the expected spectrum utilization and auction revenue. Then, the cognitive femtocell base station adjusts its reserve price with the repetition of auction to leverage over instant revenue and spectrum utilization. At the same time, the bidders can adjust their bidding price to improve utilities. Performance analysis shows that the DOF‐based DSA algorithm has low complexity and can resist collusion, so it can be carried out frequently with small overhead. On the other hand, it is better than the greedy algorithm and Vickrey–Clarke–Groves auction on revenue. Simulation results show that the DOF‐based DSA algorithm can keep a fine spectrum utilization and bring the cognitive femtocell base station more revenue in both single‐unit award spectrum auction and multi‐unit awards spectrum auction. Copyright © 2012 John Wiley & Sons, Ltd.
Spectroscopic Investigation into Oxidative Degradation of Silica‐Supported Amine Sorbents for CO2 Capture
Authors: Srikanth Chakravartula S. , Chuang Steven S. C.
Published: June 2012

Oxidative degradation characteristics of silica‐supported amine sorbents with varying amounts of tetraethylenepentamine (TEPA) and polyethylene glycol (PEG; P200 or P600 represents PEG with molecular weights of 200 or 600) have been studied by IR and NMR spectroscopy. Thermal treatment of the sorbents and liquid TEPA at 100 °C for 12 h changed their color from white to yellow. The CO2 capture capacity of the TEPA/SiO2 sorbents (i.e., SiO2‐supported TEPA with a TEPA/SiO2 ratio of 25:75) decreased by more than 60 %. IR and NMR spectroscopy studies showed that the yellow color of the degraded sorbents resulted from the formation of imide species. The imide species, consisting of NH associated with two CO functional groups, were produced from the oxidation of methylene groups in TEPA. Imide species on the degraded sorbent are not capable of binding CO2 due to its weak basicity. The addition of P200 and P600 to the supported amine sorbents improved both their CO2 capture capacities and oxidative degradation resistance. IR spectroscopy results also showed that TEPA was immobilized on the SiO2 surface through hydrogen bonding between amine groups and the silanol groups of SiO2. The OH groups of PEG interact with NH2/NH of TEPA through hydrogen bonding. Hydrogen bonds disperse TEPA on SiO2 and block O2 from accessing TEPA for oxidation. Oxidative degradation resistance and CO2 capture capacity of the supported amine sorbents can be optimized through adjusting the ratio of hydroxyl to amine groups in the TEPA/PEG mixture.
Effect of Morin on pharmacokinetics of Piracetam in rats, in vitro enzyme kinetics and metabolic stability assay using rapid UPLC method
Authors: Sahu Kapendra , Shaharyar Mohammad , Siddiqui Anees A.
Published: June 2012

The aim of this study was to investigate the effect of Morin on the pharmacokinetics of Piracetam in rats, in vitro enzyme kinetics and metabolic stability (high throughput) studies using human liver microsomes in UPLC. For pharmacokinetics studies, male Wistar rats were pretreated with Morin (10 mg/kg) for one week and on the last day, a single dose of Piracetam (50 mg/kg) was given orally. In another group, both Morin and Piracetam were co‐administered to evaluate the acute effect of Morin on Piracetam. The control group received oral distilled water for one week and administered with Piracetam on the last day. As Morin is an inhibitor of P‐ Glycoprotein (P‐gp) and CYP 3A, it was anticipated to improve the bioavailability of Piracetam. Amazingly, relative to control, the areas under the concentration time curve and peak plasma concentration of Piracetam were 1.50‐ and 1.45‐fold, respectively, greater in the Morin‐pretreated group. However, co‐administration of Morin had no significant effect on these parameters. Apart from the aforementioned merits, the results of this study are further confirmed by clinical trials; Piracetam dosages should be adjusted to avoid potential drug interaction when Piracetam is used clinically in combination with Morin and Morin‐containing dietary supplements. The in vitro enzyme kinetics were performed to determined km, Vmax & CLins. The in vitro metabolic stability executed for the estimation of metabolic rate constant and half‐life of Piracetam. These studies also extrapolate to in vivo intrinsic hepatic clearance (Clint, in vivo) from in vitro intrinsic hepatic clearance (CLint, in vitro). Copyright © 2012 John Wiley & Sons, Ltd.
Dynamics of GFRα1‐positive spermatogonia at the early stages of colonization in the recipient testes of W/Wν male mice
Authors: Nagai Ryohei , Shinomura Mai , Kishi Kasane , Aiyama Yoshimi , Harikae Kyoko , Sato Takeshi , Kanai‐Azuma Masami , Kurohmaru Masamichi , Tsunekawa Naoki , Kanai Yoshiakira
Published: June 2012

Background: The spermatogonial transplantation experiment can be used as an unequivocal detection assay of spermatogenic stem cells (SSCs) in both a qualitative and quantitative manner, based on their regenerative capacity. In this study, the proliferative patterns and kinetics of donor‐derived GFRα1‐positive spermatogonia containing potential SSCs were examined during early colonization following spermatogonial transplantation.Results: Donor‐derived GFRα1‐positive cells frequently formed several aggregates of Aal(aligned)/morula‐like structures in a single spermatogenic cell patch before and on day 14 post‐transplant, indicating a possible involvement in the formation of a stable spermatogenic colony at 21 days post‐transplant. The appearance of these Aal/morula‐like aggregates is positively correlated with regional, high‐level expression of immunoreactive GDNF signals, a ligand for GFRα1, associated with colony expansion. Conclusions: These data raise the hypothesis that regional GDNF signals regulate the balance between donor‐derived Aal‐like cell aggregates and their differentiation in each small patch, which subsequently leads to further selection of survival colonies at later stages. Developmental Dynamics 241:1374–1384, 2012. © 2012 Wiley Periodicals, Inc.
MCP‐1/CCR2 interactions direct migration of peripheral B and T lymphocytes to the thymus during acute infectious/inflammatory processes
Authors: Hodge Deborah L. , Reynolds Della , Cerbán Fabio M. , Correa Silvia G. , Baez Natalia S. , Young Howard A. , Rodriguez‐Galan Maria Cecilia
Published: June 2012

Mature lymphocyte immigration into the thymus has been documented in mouse, rat, and pig models, and highly increases when cells acquire an activated phenotype. Entrance of peripheral B and T cells into the thymus has been described in healthy and pathological situations. However, it has not been proposed that leukocyte recirculation to the thymus could be a common feature occurring during the early phase of a Th1 inflammatory/infectious process when a large number of peripheral cells acquire an activated phenotype and the cellularity of the thymus is seriously compromised. The data we present here demonstrate that in well‐established Th1 models triggered by different types of immunogens, for example, LPS treatment (a bacterial product), Candida albicans infection (a fungus), and after Trypanosoma cruzi infection (a parasite), a large number of mature peripheral B and T cells enter the thymus. This effect is dependent on, but not exclusive of, the available space in the thymus. Our data also demonstrate that MCP‐1/CCR2 (where MCP‐1 is monocyte chemoattractant protein‐1) interaction is responsible for the infiltration of peripheral cells to the thymus in these Th1‐inflammatory/infectious situations. Finally, systemic expression of IL‐12 and IL‐18 produced during the inflammatory process is ultimately responsible for these migratory events.
A new derivatization method coupled with LC‐MS/MS to enable baseline separation and quantification of dimethylarginines in human plasma from patients to receive on‐pump CABG surgery
Authors: Hui Yu , Wong Michael , Kim Joo‐oll , Love Jennifer , Ansley David M. , Chen David D.Y.
Published: June 2012

Asymmetric dimethylarginine (ADMA) is an inhibitor of nitric oxide synthase and a risk factor for cardiovascular events. We have developed a new derivatization method to enable baseline separation of the regio‐isomers, ADMA, and symmetric dimethylarginine (SDMA), within 15 min on a C18 reverse phase column. Reacting naphthalene‐2,3‐dicarboxaldehyde with ADMA and SDMA in the presence of 2‐mercaptoethanol produces corresponding 2,3‐dihydro‐benzo[f]isoindol‐1‐ones that are more stable than previously reported ortho‐phthaldialdehyde and 2‐mercaptoethanol derivatives. LC‐MS/MS quantitation of these derivatives can be used to determine ADMA and SDMA concentrations in the plasma of patients to receive on‐pump coronary artery bypass grafting (CABG) surgery. The LOD, LOQ and lower LOQ (LLOQ) of this method were determined to be 2.6, 8.7, and 25 nM for ADMA, and 2.5, 8.3, and 25 nM for SDMA, respectively, with consumption of only 50 μL of plasma. The relative standard deviations and relative errors of the intraday and interday determinations, as measurements of reproducibility and accuracy, are all within 15%. The ADMA and SDMA concentrations in patient plasma are 298.1 ± 11.2 nM (mean ± S.E.M., n = 123) and 457.7 ± 19.8 nM (mean ± S.E.M., n = 123), respectively. Upon unblinding of our clinical trial, these predetermined values might explain patient clinical outcomes associated with on‐pump CABG surgery, as ADMA is known to inhibit nitric oxide production. Furthermore, this derivatization reaction in conjunction with LC‐MS/MS analysis may open a venue to explore alternative chemical labeling modes for LC‐MS/MS applications, such as analysis of other amino acids, metabolites, and peptides containing primary amine group(s).
Using lectins to harvest the plasma/serum glycoproteome
Authors: Fanayan Susan , Hincapie Marina , Hancock William S.
Published: June 2012

Aberrant protein glycosylation has been shown to be associated with disease processes and identification of disease‐specific glycoproteins and glycosylation changes may serve as potential diagnostic and therapeutic biomarkers. However despite recent advances in proteomic‐based biomarker discovery, this knowledge has not yet translated into an extensive mining of the glycoproteome for potential biomarkers. The major challenge for a comprehensive glycoproteomics analysis arises primarily from the enormous complexity and the large dynamic range in protein constituent in biological samples. Methods that specifically target glycoproteins are therefore necessary to facilitate their selective enrichment prior to their identification by MS‐based analysis. The use of lectins, with selective affinities for specific carbohydrate epitopes, to enrich glycoprotein fractions coupled with modern MS, have greatly enhanced the identification of the glycoproteome. On account of their ability to specifically bind cell surface carbohydrates lectins have, during the recent past, found extensive applications in elucidation of the architecture and dynamics of cell surface carbohydrates, glycoconjugate purification, and structural characterization. Combined with complementary depletion and MS technologies, lectin affinity chromatography is becoming the most widely employed method of choice for biomarker discovery in cancer and other diseases.
Divergent‐flow isoelectric focusing for separation and preparative analysis of peptides
Authors: Duša Filip , Křenková Jana , Moravcová Dana , Kahle Vladislav , Šlais Karel
Published: June 2012

A divergent‐flow isoelectric focusing (DF IEF) technique has been applied for the separation and preparative analysis of peptides. The parameters of the developed DF IEF device such as dimension and shape of the separation bed, selection of nonwoven material of the channel, and separation conditions were optimized. The DF IEF device was tested by the separation of a peptide mixture originating from the tryptic digestion of BSA, cytochrome c, and myoglobin. The pH gradient of DF IEF was created by the autofocusing of tryptic peptides themselves without any addition of carrier ampholytes. The focusing process was monitored visually using colored pI markers, and the obtained fractions were analyzed by RP‐HPLC and ESI/TOF‐MS. DF IEF operating in the autofocusing mode provides an efficient preseparation of peptides, which is comparable with a commercially available MicroRotofor multicompartment electrolyzer and significantly improves sequence coverage of analyzed proteins. The potential of the DF IEF device as an efficient tool for the preparative scale separations was demonstrated by the isolation of caseinomacropeptide (CMP) from a crude whey solution.
Dietary genistein enhances phosphorylation of regulatory myosin light chain in the myocardium of ovariectomized mice
Authors: Schwab Karima , Stein Robert , Scheler Christian , Theuring Franz
Published: June 2012

There is evidence that isoflavones, such as genistein, can directly or indirectly improve lipid profile and lower blood pressure and hence exert cardiovascular protection. It is further believed, that genistein attenuates vascular contraction and thus vascular tone and blood pressure through altering the phosphorylation of the regulatory myosin light chain (MLC) probably via the myosin light chain kinase (MLCK) or the RhoA pathway. However, the direct role of genistein in the myocardium is poorly reviewed. In this study, we investigated the impact of genistein on the cardiac proteome in ovariectomized female mice using a 2DE‐MS approach. Dietary genistein intake considerably changed the abundance of several cytoskeletal and contractile proteins and enhanced the phosphorylation of MLC. The MLC phosphorylation was mediated through increased abundance of MLCK and inhibition of myosin light chain phosphatase latest known to be inversely regulated by RhoA. Contrary to others, in our model genistein did neither inhibit the cardiac MLCK, nor the cardiac RhoA pathway in vivo.
The determination of tissue‐specific DNA methylation patterns in forensic biofluids using bisulfite modification and pyrosequencing
Authors: Madi Tania , Balamurugan Kuppareddi , Bombardi Robin , Duncan George , McCord Bruce
Published: June 2012

The goal of this study is to explore the application of epigenetic markers in the identification of biofluids that are commonly found at the crime scene. A series of genetic loci were examined in order to define epigenetic markers that display differential methylation patterns between blood, saliva, semen, and epithelial tissue. Among the different loci tested, we have identified a panel of markers, C20orf117, ZC3H12D, BCAS4, and FGF7, that can be used in the determination of these four tissue types. Since methylation modifications occur at cytosine bases that are immediately followed by guanine bases (CpG sites), methylation levels were measured at CpG sites spanning each marker. Up to 11 samples of each tissue type were collected and subjected to bisulfite modification to convert unmethylated CpG‐associated cytosine bases to thymine bases. The bisulfite modified DNA was then amplified via nested PCR using a primer set of which one primer was biotin labeled. Biotinylated PCR products were in turn analyzed and the methylation level at each CpG site was quantitated by pyrosequencing. The percent methylation values at each CpG site were determined and averaged for each tissue type. The results indicated significant methylation differences between the tissue types. The methylation patterns at the ZC3H12D and FGF7 loci differentiated sperm from blood, saliva, and epithelial cells. The C20orf117 locus differentiated blood from sperm, saliva, and epithelial cells and saliva was differentiated from blood, sperm, and epithelial cells at a fourth locus, BCAS4. The results of this study demonstrate the applicability of epigenetic markers as a novel tool for the determination of biofluids using bisulfite modification and pyrosequencing.
Use of MDLC‐DIGE and LC‐MS/MS to identify serum biomarkers for complete remission in patients with acute myeloid leukemia
Authors: Lee Seung‐Won , Kim In Jae , Jeong Bo Yoon , Choi Mun‐Ho , Kim Jin Young , Kwon Kyung‐Hoon , Lee Jae Won , Yu Ami , Shin Myung‐Geun
Published: June 2012

The response criteria for complete remission (CR) in acute myeloid leukemia (AML) are currently based on morphology and blood cell counts. However, these criteria are insufficient to establish a diagnosis in cases with poor quality bone marrow (BM) samples demonstrating a loss of cellular morphology. We investigated whether the sera of patients contained biomarkers that indicate disease response status. First, we performed multidimensional liquid chromatography‐differential gel electrophoresis (MDLC‐DIGE) to generate protein profiles of two pooled, paired serum samples from patients who had achieved CR; one collected at diagnosis (PreCR) and the other collected after chemotherapy (CR). Then, with the biomarker candidates found, ELISA was carried out for individual PreCR and CR samples, and for other verification sets including nonremission (NR) patients and normal samples. We selected two proteins, complement factor H (CFH) and apolipoprotein H (ApoH), with dye (Cy) ratios showing greater than 2.0‐fold differences between the pooled samples. ELISA showed that CFH and ApoH are useful for distinguishing between the recovered (CR and normal) and nonrecovered (PreCR, PreNR, and NR) states in AML (p <0.001). We successfully applied a protein profiling technology of MDLC‐DIGE and LC‐MS/MS to discover two biomarkers for CR which needs further validation for a clinical setting.
Strategic and Tactical Roles of Enhanced Commodity Indices
Authors: Rallis Georgios , Miffre Joëlle , Fuertes Ana‐Maria
Published: June 2012

This article formally compares two traditional long‐only commodity indices, Standard & Poor's Goldman Sachs Commodity Index (S&P‐GSCI) and Dow Jones‐UBS Commodity Index (DJ‐UBSCI), with their enhanced versions that exploit signals based on contract maturity, momentum, and term structure. The enhanced indices are found to be useful for tactical asset allocation. With alphas ranging from 2.77% to 5.49% per annum, the maturity‐enhanced indices offer the best abnormal performance after accounting for liquidity risk. Momentum and term structure enhancements also earn a positive, albeit smaller, alpha of 2.10% per annum on average. All the enhanced indices are found to have comparable effectiveness for risk diversification and inflation hedging as their traditional counterparts, making them useful for strategic asset allocation.
Longitudinal studies of cerebral glucose metabolism in late‐life depression and normal aging
Authors: Marano Christopher M. , Workman Clifford I. , Kramer Elisse , Hermann Carol R. , Ma Yilong , Dhawan Vijay , Chaly Thomas , Eidelberg David , Smith Gwenn S.
Published: June 2012

Objective

Late‐life depression (LLD) has a substantial public health impact and is both a risk factor for and a prodrome of dementia. Positron emission tomography (PET) studies of cerebral glucose metabolism have demonstrated sensitivity in evaluating neural circuitry involved in depression, aging, incipient cognitive decline, and dementia. The present study evaluated the long term effects of a course of antidepressant treatment on glucose metabolism in LLD patients.

Methods

Nine LLD patients and seven non‐depressed control subjects underwent clinical and cognitive evaluations as well as brain magnetic resonance imaging and PET studies of cerebral glucose metabolism at baseline, after 8 weeks of treatment with citalopram for a major depressive episode (patients only), and at an approximately 2‐year follow‐up.

Results

The majority of LLD patients were remitted at follow‐up (7/9). Neither patients nor controls showed significant cognitive decline. The patients showed greater increases in glucose metabolism than the controls in regions associated with mood symptoms (anterior cingulate and insula). Both groups showed decreases in metabolism in posterior association cortices implicated in dementia.

Conclusions

Longitudinal changes in cerebral glucose metabolism are observed in controls and in LLD patients without significant cognitive decline that are more extensive than the decreases in brain volume. Longer duration follow‐up studies and the integration of other molecular imaging methods will have implications for understanding the clinical and neurobiological significance of these metabolic changes. Copyright © 2012 John Wiley & Sons, Ltd.
Alcohols Promoted Green Protocol for Biginelli Reaction
Authors: Imtiaz Shamila , Khan Misbahul Ain , Sharif Ahsan , Ahmed Ejaz , Lin Whei‐Oh , Munawar Munawar Ali
Published: June 2012

A green chemistry protocol using ethylene glycol and diethylene glycol is developed for the synthesis of dihydropyrimidinones.
Theoretical Study on the Gas‐Phase SN2 Reaction of Microhydrated Fluoride with Methyl Fluoride
Authors: Chen Jien‐Lian , Hu Wei‐Ping
Published: June 2012

The rate constants for the gas‐phase SN2 reaction of F−(H2O) with CH3F have been calculated using the dual‐level variational transition state theory including multidimensional tunneling from 50 to 500 K. Tunneling was found to dominate the reaction below 200 K. The deuterium, 13C, and 14C kinetic isotope effects (KIEs) and solvent (D2O) isotope effects (SKIEs) were also calculated in the same temperature range. The results indicated that the deuterium and heavy water substitutions resulted in inverse KIEs (0.6∼0.8 ) while the 13C and 14C substitutions resulted in normal KIEs (1.0∼1.2) at room temperature. The calculated carbon KIEs increased significantly below 80 K due to the differences in the magnitude of the tunneling effects for different isotopic substitutions.
Flow‐sensitive 4D MRI of the thoracic aorta: Comparison of image quality, quantitative flow, and wall parameters at 1.5 T and 3 T
Authors: Strecker Christoph , Harloff Andreas , Wallis Wolf , Markl Michael
Published: June 2012

Purpose:

To evaluate the effect of field strength on flow‐sensitive 4D magnetic resonance imaging (MRI) of the thoracic aorta. A volunteer study at 1.5 T and 3 T was conducted to compare phase‐contrast MR angiography (MRA) and 3D flow visualization quality as well as quantification of aortic hemodynamics.

Materials and Methods:

Ten healthy volunteers were examined by flow‐sensitive 4D MRI at both 1.5 T and 3 T MRI with identical imaging parameters (TE/TR = 6/5.1 msec, spatial/temporal resolution ≈2 mm/40.8 msec). Analysis included assessment of image quality of derived aortic 3D phase contrast (PC) angiography and 3D flow visualization (semiquantitative grading on a 0–2 scale, two blinded observers) and quantification of blood flow velocities, net flow per cardiac cycle, wall shear stress (WSS), and velocity noise.

Results:

Quality of 3D blood flow visualization (average grading = 1.8 ± 0.4 at 3 T vs. 1.1 ± 0.7 at 1.5 T) and the depiction of aortic lumen geometry by 3D PC‐MRA (1.7 ± 0.5 vs. 1.2 ± 0.6) were significantly (P < 0.01) improved at 3 T while velocity noise was significantly higher (P < 0.01) at 1.5 T. Velocity quantification resulted in minimally altered (0.05 m/s, 3 mL/cycle and 0.01 N/m2) but not statistically different (P = 0.40, P = 0.39, and P = 0.82) systolic peak velocities, net flow, and WSS for 1.5 T compared to 3 T.

Conclusion:

Flow‐sensitive 4D MRI at 3 T provided improved image quality without additional artifacts related to higher fields. Imaging at 1.5 T MRI, which is more widely available, was also feasible and provided information on aortic 3D hemodynamics of moderate quality with identical performance regarding quantitative analysis. J. Magn. Reson. Imaging 2012;36:1097–1103. © 2012 Wiley Periodicals, Inc.