bluuebunny/crossref_metadata_2025 huggingface dataset:
Improved one‐step steam pretreatment of SO2‐Impregnated softwood with time‐dependent temperature profile for ethanol production
Authors: Monavari Sanam , Bennato Andrea , Galbe Mats , Zacchi Guido
Published: March 2010

In the production of ethanol from lignocellulosic material, pretreatment of the raw material before enzymatic hydrolysis and fermentation is essential to obtain high overall yields of sugar and ethanol. Two‐step steam pretreatment results in higher ethanol yields from softwood than the standard one‐step pretreatment process. However, the difficulty with separation and washing of the material at high pressure between the two pretreatment steps is a major drawback. In this study, a new one‐step pretreatment procedure was investigated, in which the time‐temperature profile was varied during pretreatment. The efficiency of pretreatment was assessed by performing simultaneous saccharification and fermentation on the pretreated slurries. Pretreatment of SO2‐impregnated softwood performed by varying the temperature (190–226°C), the residence time (5–10 min), and the mode of temperature increase (linear or stepwise), resulted in recovery of about 90% of the mannose and glucose present in the raw material. The highest ethanol yield, 75% of theoretical based on the glucan and mannan content of the raw material, was obtained at pretreatment conditions of 190°C for 12 min. Similar ethanol yields were achieved when running the pretreatment as one‐step (190–200°C), two levels of temperature, at shorter residence time (7 min), which results in lower capital costs for the process. © 2010 American Institute of Chemical Engineers Biotechnol. Prog., 2010
Microplate‐reader compatible perfusion microbioreactor array for modular tissue culture and cytotoxicity assays
Authors: Wen Yuan , Zhang Xudong , Yang Shang‐Tian
Published: March 2010

One important application of tissue engineering is to provide novel in vitro models for cell‐based assays. Perfusion microbioreactor array provides a useful tool for microscale tissue culture in parallel. However, high‐throughput data generation has been a challenge. In this study, a 4 × 4 array of perfusion microbioreactors was developed for plate‐reader compatible, time‐series quantification of cell proliferation, and cytotoxicity assays. The device was built through multilayer soft lithography. Low‐cost nonwoven polyethylene terephthalate fibrous matrices were integrated as modular tissue culture scaffolds. Human colon cancer HT‐29 cells with stable expression of enhanced green fluorescent protein were cultured in the device with continuous perfusion and reached a cell density over 5 × 107 cells/mL. The microbioreactor array was used to test a chemotherapeutic drug 5‐FU for its effect on HT‐29 cells in continuous perfusion 3D culture. Compared with conventional 2D cytotoxicity assay, significant drug resistance was observed in the 3D perfusion culture. © 2010 American Institute of Chemical Engineers Biotechnol. Prog., 2010
RNA‐Cleaving Deoxyribozyme Sensor for Nucleic Acid Analysis: The Limit of Detection
Authors: Gerasimova Yulia V. , Cornett Evan , Kolpashchikov Dmitry M.
Published: March 2010

Along with biocompatibility, chemical stability, and simplicity of structural prediction and modification, deoxyribozyme‐based molecular sensors have the potential of an improved detection limit due to their ability to catalytically amplify signal. This study contributes to the understanding of the factors responsible for the limit of detection (LOD) of RNA‐cleaving deoxyribozyme sensors. A new sensor that detects specific DNA/RNA sequences was designed from deoxyribozyme OA‐II [Chiuman, W.; Li, Y. (2006) J. Mol. Biol. 357, 748–754]. The sensor architecture allows for a unique combination of high selectivity, low LOD and the convenience of fluorescent signal monitoring in homogeneous solution. The LOD of the sensor was found to be ∼1.6×10−10 M after 3 h of incubation. An equation that allows estimation of the lowest theoretical LOD using characteristics of parent deoxyribozymes and their fluorogenic substrates was derived and experimentally verified. According to the equation, “catalytically perfect” enzymes can serve as scaffolds for the design of sensors with the LOD not lower than ∼2×10−15 M after 3 h of incubation. A new value termed the detection efficiency (DE) is suggested as a time‐independent characteristic of a sensor's sensitivity. The expressions for the theoretical LOD and DE can be used to evaluate nucleic acid and protein enzymes for their application as biosensing platforms.
Photocaged T7 RNA Polymerase for the Light Activation of Transcription and Gene Function in Pro‐ and Eukaryotic Cells
Authors: Chou Chungjung , Young Douglas D. , Deiters Alexander
Published: March 2010

A light‐activatable bacteriophage T7 RNA polymerase (T7RNAP) has been generated through the site‐specific introduction of a photocaged tyrosine residue at the crucial position Tyr639 within the active site of the enzyme. The photocaged tyrosine disrupts polymerase activity by blocking the incoming nucleotide from reaching the active site of the enzyme. However, a brief irradiation with nonphototoxic UV light of 365 nm removes the ortho‐nitrobenzyl caging group from Tyr639 and restores the RNA polymerase activity of T7RNAP. The complete orthogonality of T7RNAP to all endogenous RNA polymerases in pro‐ and eukaryotic systems allowed for the photochemical activation of gene expression in bacterial and mammalian cells. Specifically, E. coli cells were engineered to produce photocaged T7RNAP in the presence of a GFP reporter gene under the control of a T7 promoter. UV irradiation of these cells led to the spatiotemporal activation of GFP expression. In an analogous fashion, caged T7RNAP was transfected into human embryonic kidney (HEK293T) cells. Irradiation with UV light led to the activation of T7RNAP, thereby inducing RNA polymerization and expression of a luciferase reporter gene in tissue culture. The ability to achieve spatiotemporal regulation of orthogonal RNA synthesis enables the precise dissection and manipulation of a wide range of cellular events, including gene function.
A longitudinal analysis of early risk factors for adult‐onset offending: What predicts a delayed criminal career?
Authors: Zara Georgia , Farrington David P.
Published: March 2010

Background Late‐onset offending, at the age of 21 or thereafter, is an underexplored dimension of the criminal career.

Aims Our aims were to explore which factors are precursors of late‐onset offending, and the extent to which adult criminality can be predicted in childhood and adolescence.

Method This is the first study that defines late‐onset offending based on a combination of official records and self‐reports. Longitudinal data from the Cambridge Study in Delinquent Development (CSDD) were used. Four hundred and three South London men, followed from ages 8–10 to ages 48–50, were divided into late‐starters (LS,n= 51), early‐starters (ES,n= 140) and non‐offenders (NO,n= 212).

Results LS men were more likely than NO men to have been neurotic, truants or in poor housing at ages 8–10. At ages 12–14, they tended to be neurotic, and at ages 16–18, they had high unemployment and spent time hanging about on the streets. Compared with ES, LS were nervous at ages 8–10, and at age 18 they were more likely to be sexual virgins. Overall, LS men were more similar to NO men before age 21, but more similar to ES men by age 32.

Conclusions Our hypotheses that late‐onset offenders would be particularly characterised by neuroticism or nervousness, but that this would buffer rather than fully protect over the life course, were sustained. Intervention to increase the resilience of children and adolescents who are rated as high on neurotic characteristics may lessen the burden that these factors impose in adult life and reduce the risk of a deteriorating quality of life and late onset criminal careers. Copyright © 2010 John Wiley & Sons, Ltd.
Importance of the angiosome concept for endovascular therapy in patients with critical limb ischemia
Authors: Iida Osamu , Nanto Shinsuke , Uematsu Masaaki , Ikeoka Kuniyasu , Okamoto Shin , Dohi Tomoharu , Fujita Masashi , Terashi Hiroto , Nagata Seiki
Published: March 2010

Objective: We investigated the role of the angiosome concept in endovascular therapy (EVT) for limb salvage. Background: The angiosome concept is clinically useful in bypass surgery for critical limbs ischemia (CLI). However, comparison with direct and indirect flow to the site of ulceration based on angiosome concept regarding freedom from amputation has not been systematically studied for the patient with CLI undergoing EVT. Methods: We analyzed 203 limbs in 177 consecutive patients (male = 127, age = 70 ± 11 years) with ischemic ulceration that was Rutherford 5 or 6 (5 in 145 limbs and 6 in 58 limbs; pretreatment ankle‐brachial index = 0.74 ± 0.27), who underwent EVT alone without bypass surgery. We classified these patients into direct and indirect groups depending on whether feeding artery flow to the site of ulceration was successfully acquired or not acquired based on the angiosome concept. Freedom from amputation was compared between the direct and the indirect groups by Kaplan‐Meier analysis. Results: The overall limb salvage rate was 82% (167/203). Skin perfusion pressure was significantly higher in the direct group (67 ± 25 mm Hg) than in the indirect group (41 ± 20 mm Hg, P = 0.002). The limb salvage rate was also significantly (P = 0.03) higher in the direct group (86%) than in the indirect group (69%) for up to 4 years after the procedure. The number of vessels with run‐off flow did not influence the limb salvage rate in either the direct group (P = 0.84) or the indirect group (P = 0.90). Conclusion: Acquiring direct flow based on the angiosome concept is important for limb salvage by EVT in patients with CLI.© 2010 Wiley‐Liss, Inc.
Percutaneous closure of an aneurysmal patent ductus arteriosus in an adult
Authors: Schussler Jeffrey M. , Choi James W.
Published: March 2010

We report a case of a 24 year old woman with an aneurysmal patent ductus arteriosus (PDA) that was percutaneously closed using an Amplatzer Vascular Plug II. This is the first report of the successful use of an Amplatzer Vascular Plug II for a PDA, and suggests the feasibility and safety of its utilization in select cases. © 2010 Wiley‐Liss, Inc.
Percutaneous closure of patent ductus arteriosus: A multiinstitutional registry comparing multiple devices
Authors: Brunetti Marissa A. , Ringel Richard , Owada Carl , Coulson John , Jennings Jacky M. , Hoyer Mark H. , Everett Allen D.
Published: March 2010

Background: There are no guidelines and multiple devices available now for closure of PDA. Objective: We sought to determine which devices are used and their outcomes. Methods: Prospectively collected data on closure of PDA at 12 US catheterization labs was entered into the MAGIC data registry between November 2005 and September 2008. Results: PDA closure was accomplished in 357 of 359 attempted closures during the study period. Mean age, weight, and minimum ductal diameter were 4.3 ± 6.8 years, 18.7 ± 18.4 kg, and 2.1 ± 1.4 mm, respectively. Devices used were Gianturco coils (161/359), Amplatzer Duct Occluder (ADO, 174/359), Flipper coils (18/359), and other devices (6/359). Gianturco coils had the least fluoroscopy and contrast exposure (8.7 ± 7.5 min, P = 0.00001, 2.6 ± 1.4 cm3 kg−1, P = 0.00001). Immediate angiographic success rates were 96.9% (156/161) for Gianturco coils, 89.7% (156/174) for the ADO, 100% (18/18) for Flipper coils, and 66.7% (4/6) for other devices. Major complication rates were 0.6% for Gianturco coils (1/161), 1.7% for ADO (3/174), and 83.3% for other devices (4/6). Minor complication rates by device were 1.9% for Gianturco coils (3/161), 2.3% for ADO (4/174), and 16.7% (1/6) for other devices. Conclusions: Gianturco coils, the ADO and Flipper coils were immediately successful with low complication profiles. The ADO and Gianturco coils were the predominate devices. The ADO was the device of choice for PDA > 3 mm with good success. In PDA < 3 mm, the Gianturco coil is as effective and safe as the ADO with less cost, less radiation, and less contrast exposure. © 2010 Wiley‐Liss, Inc.
Early assessment of infarct size and prediction of functional recovery by quantitative myocardial blush grade in patients with acute coronary syndromes treated according to current guidelines
Authors: Riedle Nina , Dickhaus Hartmut , Erbacher Markus , Steen Henning , Andrassy Martin , Lossnitzer Dirk , Hardt Stefan , Rottbauer Wolfgang , Zugck Christian , Giannitsis Evangelos , Katus Hugo A. , Korosoglou Grigorios
Published: March 2010

Purpose: To determine whether quantification of myocardial blush grade (MBG) during cardiac catheterization can aid the determination of follow‐up left ventricular (LV)‐function in patients with ST‐elevation and non‐ST‐elevation myocardial infarction (STEMI and NSTEMI). Methods: We prospectively examined patients with first STEMI (n = 46) and NSTEMI (n = 49). ECG‐gated angiographic series were used to quantify MBG by analyzing the time course of contrast agent intensity rise. Hereby, the parameter Gmax/Tmax was calculated, derived from the plateau of grey‐level intensity (Gmax), divided by the time‐to‐peak intensity (Tmax). Cardiac magnetic resonance imaging (CMR) deemed as the standard reference for the estimation of infarct size, transmurality and of the LV‐function at 6 months of follow‐up. Results: Cut‐off values of Gmax/Tmax=5.7/sec and 3.8/sec, respectively, yielded similar accuracy as infarct transmurality for the prediction of follow‐up ejection fraction >55% (AUC = 0.86 for STEMI and AUC = 0.90 for NSTEMI, by Gmax/Tmax and AUC = 0.85 for STEMI and AUC = 0.89 for NSTEMI, by infarct transmurality, respectively, P = NS). Both clearly surpassed the predictive value of visual MBG (AUC = 0.69 for STEMI and AUC = 0.68 for NSTEMI, P < 0.05). Conclusion: Gmax/Tmax is an easy to acquire but highly valuable surrogate parameter for infarct size, which yields equally high accuracy with infarct transmurality and favorably compares with visually assessed blush grades for the prediction of follow‐up LV‐function in patients with acute ischemic syndromes. © 2010 Wiley‐Liss, Inc.
Transcatheter treatment of “complex” aortic coarctation
Authors: Santoro Giuseppe , Qureshi Shakeel , Russo Maria Giovanna
Published: March 2010

A young woman, submitted to aortic coarctation repair in early infancy, was referred with clinical and echocardiographic signs of severe recoarctation. Spiral CT scan confirmed the aortic isthmus obstruction but imaged also a huge aneurysm distal to the coarctation site, from which arose a large aberrant right subclavian artery. In cardiac catheterization, this vessel showed an upper‐to‐lower flow direction and its closure was deemed mandatory to abolish a major feeding source to the aneurysmal sack. Thus, this anomalous vessel was occluded with an Amplatzer Duct Occluder device and multiple covered Cheatham‐Platinum stents were telescopically implanted into the thoracic aorta to dilate the coarctation and exclude the aneurysm. In conclusion, percutaneous transcatheter treatment is feasible, safe, and cost‐effective even in aortic arch obstructions with complex anatomic arrangement. © 2010 Wiley‐Liss, Inc.
Angioplasty of ulnar or radial arteries to treat critical hand ischemia: Use of 3‐ and 4‐French Systems
Authors: Kawarada Osami , Yokoi Yoshiaki , Higashimori Akihiro
Published: March 2010

Objectives: The aim of this preliminary study is to report the results of catheter‐based treatment for isolated distal upper extremity artery disease with CHI. Background: Critical hand ischemia (CHI) is a rare but potentially devastating condition. Methods: The study consisted of five critically ischemic hands (Rutherford category 4: 2, Rutherford category 5: 3) in four patients undergoing catheter intervention for isolated distal upper extremity artery disease between November 2007 and April 2009. Results: Balloon angioplasty via an antegrade brachial approach was performed with a 3Fr or 4Fr sheath to achieve the principal endpoint of the establishment of one straight‐line flow to the palmar arch. All patients had end‐stage renal disease requiring chronic hemodialysis. The target vessels were the ulnar artery in four cases, the radial artery in one, and the palmar arch in two. Four cases had a stenotic lesion and one had chronic total occlusion. Technical success was achieved in all cases without complications, and skin perfusion pressure of the hand improved significantly from 39 ± 20 to 52 ± 16 (P = 0.019) on the palmar side and from 40 ± 18 to 60 ± 29 on the dorsal side (P = 0.046). Clinical success was achieved in all cases during a mean follow‐up period of 11 ± 8 (2–19) months. Conclusions: Percutaneous angioplasty using contemporary dedicated devices could be a potentially useful option for CHI patients with isolated distal upper extremity artery disease. © 2010 Wiley‐Liss, Inc.
Mitral valve repair with the MitraClip device after prior surgical mitral annuloplasty
Authors: Lim D. Scott , Kunjummen Binu J. , Smalling Richard
Published: March 2010

While mitral valve repair using the MitraClip device is currently being evaluated in the EVEREST trials, surgical approaches to mitral regurgitation remain the standard of care, at least for operative candidates. Two patients in whom previous surgical annuloplasty failed to maintain MR reduction and who were treated with the MitraClip device after mitral valve repair surgery are described. Imaging and hemodynamic considerations associated with this approach are discussed. © 2010 Wiley‐Liss, Inc.
Transthoracic echocardiographic assistance for interatrial stenting in low birth‐Weight neonates with hypoplastic left heart syndrome and intact atrial septum
Authors: Petit Christopher J. , Altman Carolyn A. , Pignatelli Ricardo H.
Published: March 2010

Infants with hypoplastic left heart syndrome and intact or highly restrictive atrial septum require emergent therapy to relieve pulmonary congestion. Transcatheter stenting has become, in most large centers, the mainstay of therapy for relief of left atrial hypertension. Normally, this procedure is performed with the assistance of transesophageal echocardiographic guidance. However, the transesophageal approach is untenable in neonates of low birth weight, as the transducers can be traumatic and can cause ventilatory difficulty. We present two cases in which transthoracic echocardiographic guidance was used to guide atrial perforation and stenting in low birth‐weight neonates with hypoplastic left heart syndrome with intact or highly restrictive atrial septum. Both procedures were straightforward and there were no complications. Real‐time biplane imaging greatly assisted in the intervention in one case. The advantages of this approach are discussed. © 2010 Wiley‐Liss, Inc.
Reduction in spasm with a long hydrophylic transradial sheath
Authors: Caussin Christophe , Gharbi Mostari , Durier Chloé , Ghostine Saïd , Pesenti‐Rossi David , Rahal Saliha , Brenot Philippe , Barri Maruan , Durup Florence , Lancelin Bernard
Published: March 2010

Objectives: We aimed to assess the efficiency of a long hydrophilic sheath in reducing radial spasm for transradial approach. Background: Despite a lower access site complication rate, cardiac catheterization using transradial approach is not widely used. Radial spasm is one of the main issues for transradial angiography and percutaneous interventions. We assumed that radial artery protection using a long hydrophilic‐coated sheath would reduce radial spasm compared to a bare short sheath. Methods: Three hundred and fifty one patients (pts) admitted for transradial coronary angiography ± percutaneous coronary interventions were randomly assigned to a long hydrophilic‐coated or a short sheath (control group). Primary end point was the occurrence of a radial spasm defined by significant patient pain evaluated by scale score (>4) or significant catheter frictions during manipulation. Procedure failure, radial occlusion, and local complications were also assessed. Results: Radial spasm was significantly reduced when using the long‐coated compared to the short sheath in 7 (4%) vs. 32 pts (18%) P < 0.001. No difference was found regarding procedure failure respectively 1.2% vs. 0.6%, local complication 0.6% vs. 1.2%, and radial occlusion 3.5% vs. 3.5%. Conclusion: Radial artery protection using the long hydrophilic‐coated sheath was efficient in the prevention of radial spasm for transradial approach. © 2010 Wiley‐Liss, Inc.
Migration of covered stents from hemodialysis A‐V access to the pulmonary artery: Percutaneous stent retrieval and procedural trends
Authors: Dashkoff Neil , Blessios George A. , Cox Matthew R.
Published: March 2010

Details are presented of two patients with end‐stage renal disease (ESRD) who recently experienced migration of a Viabahn covered stent from a peripheral hemodialysis A‐V access to the right lower lobe pulmonary artery. Successful percutaneous retrieval was achieved in one patient using a dual snare approach, facilitated by ex vivo product testing. The second patient was managed conservatively. A review of the institution's A‐V access salvage procedures, indicated a concomitant trend toward greater use of stent‐assisted procedures, and a higher utilization of covered versus uncovered stents. © 2010 Wiley‐Liss, Inc.
Lung perfusion studies after transcatheter closure of persistent ductus arteriosus with the Amplatzer duct occluder
Authors: Polat Tugcin Bora , Celebi Ahmet , Hacımahmutoglu Sevim , Akdeniz Celal , Erdem Abdullah , Fırat Fatih
Published: March 2010

Background: Reduced left lung perfusion has been described after transcatheter closure of the patent ductus arteriosus (PDA) with several prostheses. Although the Amplatzer ductal occluder (ADO) device is currently the most widely used occluder for closure of large‐sized PDAs, the potential consequences of flow distribution to the lungs of this device have not been completely clarified. We evaluated lung perfusion following occlusion of PDA with the ADO device. Methods: Forty‐seven patients underwent successful transcatheter PDA occlusion using the ADO device were included in this study. Lung perfusion scans were performed 6 months after the procedure. Results: Decreased perfusion to the left lung (defined as < 40% of total lung flow) was observed in 17 patients (36%), 5 of whom were low‐weight symptomatic infants. Ductal ampulla length was significantly shorter and minimal ductal diameter to ampulla diameter ratio was significantly higher in patients with decreased left lung perfusion and correlated well with left lung perfusion values (r = 0.516 and r = −0.501, respectively). A cut‐off value of ≤5.8 mm for the ductal ampulla length and ≥1.9 for ampulla diameter to ampulla length ratio showed high sensitivity and specificity for reduced lung perfusion. Conclusions: The incidence of abnormal left lung perfusion is high 6 months after transcatheter closure of PDA with the ADO, more likely in the low weight symptomatic infants and in patients with a short duct or a relatively shallow duct having abrupt narrowing of a large ampulla. © 2010 Wiley‐Liss, Inc.
Percutaneous intervention of left main coronary artery compression by pulmonary artery aneurysm
Authors: Vaseghi Marmar , Lee Michael S. , Currier Jesse , Tobis Jonathan , Shapiro Shelley , Aboulhosn Jamil
Published: March 2010

Background: Extrinsic compression of the left main coronary artery (LMCA) by a pulmonary artery aneurysm (PAA) has become increasingly recognized as an etiology of angina in patients with pulmonary arterial hypertension (PAH). The purpose of this study was to assess the feasibility and efficacy of LMCA stenting in the treatment LMCA stenosis because of PAA. Methods: Retrospective analysis of data on patients with PAH who presented with angina and underwent percutaneous intervention of their LMCA compression because of PAA was performed. Results: Five patients (age 51 ± 16 years, all female) with PAH presented with angina and underwent LMCA stenting between 2007 and 2009. Four had positive cardiac enzymes. LMCA compression because of a PAA was diagnosed in all patients with cardiac CT angiography after echocardiography demonstrated an enlarged pulmonary artery. LMCA stenting was successfully performed in all patients with resolution of angina and electrocardiographic abnormalities. After a mean follow‐up of 16.6 ± 15.7 months (range of 5–39 months), patients remained angina free, no complications of the procedure were noted, and long term stent patency was confirmed in three of the five patients who underwent repeat cardiac CT angiography. Conclusions: LMCA stenting appears to be a feasible and durable option in patients who present with angina because of compression by PAA. This procedure was well tolerated and is of particular value given the increased surgical risk in patients with PAH. © 2010 Wiley‐Liss, Inc.
A new dedicated ultrashort steerable balloon for side branch ostial dilatation
Authors: Secco Gioel Gabrio , Di Mario Carlo
Published: March 2010

A dedicated balloon with a short beveled tip and the ability to rotate it from the proximal hub was successfully used to dilate the origin of a side branch which became totally occluded after deployment of a stent in the main vessel. Although regular low profile balloons are mostly successful in crossing struts of previously deployed stents, this new device has the potential to offer a more predictable and rapid solution in routine practice. © 2010 Wiley‐Liss, Inc.
Comparative Study of Copper‐ and Silver‐Catalyzed Protodecarboxylations of Carboxylic Acids
Authors: Gooßen Lukas J. , Rodríguez Nuria , Linder Christophe , Lange Paul P. , Fromm Andreas
Published: March 2010

The protodecarboxylation of aromatic carboxylic acids by various copper and silver catalysts is investigated with the help of density functional calculations and experimental studies. The computational results reveal that the catalytic activity of copper(I)–1,10‐phenanthroline catalysts increases with the introduction of electron‐rich substituents at the phenanthroline ligand. They also predicted that for some substrates, silver complexes should possess a substantially higher decarboxylating activity than copper, which is confirmed by experimental studies, leading to the discovery of a silver(I) catalyst that effectively promotes the protodecarboxylation of various carboxylic acids at temperatures in the range of 80–120 °C—more than 50 °C below those of the best known copper(I) catalyst. The scope of the new system complements that of the copper(I)‐based method as it includes benzoates for example, with halogen or ether groups in the ortho positions.
Gold‐Catalyzed Cross‐Couplings: New Opportunities for CC Bond Formation
Authors: Garcia Pierre , Malacria Max , Aubert Corinne , Gandon Vincent , Fensterbank Louis
Published: March 2010

Cross‐coupling is a powerful tool for the rapid construction of highly valuable compounds. In this area of chemical transformations, new catalysts have recently emerged. Combining both a π‐Lewis acid character and interesting redox properties, gold has proven to be an expedient choice for mediating such transformations. Recent developments in the use of gold to mediate a variety of CC coupling reactions are summarized, including Suzuki and Sonogashira cross‐coupling reactions, as well as the development of tandem processes and the combination of gold with palladium to enable CC bond formation via transmetalation.
Disjoint hard models for classification
Authors: Li Dong , Lloyd Gavin R , Duncan John C , Brereton Richard G
Published: March 2010

The paper describes a new approach for disjoint hard modelling of classes. This involves developing independent PC models for each group in the class, and calculating both the Q statistic (square prediction error) for each sample to the class model and a separate statistic about how well samples are classified within the projected PC space. The latter statistic can be applied to different types of classifiers, in this paper we choose to illustrate by Quadratic Discriminant Analysis (D statistic) and one class Support Vector Domain Description (SVDD) (f‐value). The two measures (Q and the classifier dependent statistic) are combined into a joint decision function which uniquely classifies each sample. The disjoint hard models are contrasted to conjoint models where PCA is performed on the entire dataset using both QDA and Support Vector Machines (SVMs) classifiers. The optimum number of PCs for each model is determined using the bootstrap, and model performance assessed on 100 test sets obtained using different iterative splits, using %PA (Predictive Ability) and %CR (Classification Rate). The method is illustrated using a dataset consisting of 293 samples from nine groups of polymers obtained using thermal profiling. The approach described, in this paper, has many of the advantages of one class disjoint models (e.g. SIMCA) and of conventional hard models, and is useful if it is known that all samples must belong to one of a series of known groups but each group has a very different structure. Copyright © 2010 John Wiley & Sons, Ltd.
Synthesis, Magnetic Properties, and STM Spectroscopy of Cobalt(II) Cubanes [CoII4(Cl)4(HL)4]
Authors: Scheurer Andreas , Ako Ayuk M. , Saalfrank Rolf W. , Heinemann Frank W. , Hampel Frank , Petukhov Konstantin , Gieb Klaus , Stocker Michael , Müller Paul
Published: March 2010

Reaction of cobalt(II) chloride hexahydrate with N‐substituted diethanolamines H2L2–4 (3) in the presence of LiH in anhydrous THF leads under anaerobic conditions to the formation of three isostructural tetranuclear cobalt(II) complexes [CoII4(Cl)4(HL2–4)4] (4) with a [Co4(μ3‐O)4]4+ cubane core. According to X‐ray structural analyses, the complexes 4 a,c crystallize in the tetragonal space group I41/a, whereas for complex 4 b the tetragonal space group P$\bar 4$ was found. In the solid state the orientation of the cubane cores and the formation of a 3D framework were controlled by the ligand substituents of the cobalt(II) cubanes 4. This also allowed detailed magnetic investigations on single crystals. The analysis of the SQUID magnetic susceptibility data for 4 a gave intramolecular ferromagnetic couplings of the cobalt(II) ions (J1≈20.4 K, J2≈7.6 K), resulting in an S=6 ground‐state multiplet. The anisotropy was found to be of the easy‐axis type (D=−1.55 K) with a resulting anisotropy barrier of Δ≈55.8 K. Two‐dimensional electron‐gas (2DEG) Hall magnetization measurements revealed that complex 4 a is a single‐molecule magnet and shows hysteretic magnetization characteristics with typical temperature and sweep‐rate dependencies below a blocking temperature of about 4.4 K. The hysteresis loops collapse at zero field owing to fast quantum tunneling of the magnetization (QTM). The structural and electronic properties of cobalt(II) cubane 4 a, deposited on a highly oriented pyrolytic graphite (HOPG) surface, were investigated by means of STM and current imaging tunneling spectroscopy (CITS) at RT and standard atmospheric pressure. In CITS measurements the rather large contrast found at the expected locations of the metal centers of the molecules indicated the presence of a strongly localized LUMO.
The Effect of the Equatorial Environment on Oxo‐Group Silylation of the Uranyl Dication: A Computational Study
Authors: Yahia Ahmed , Arnold Polly L. , Love Jason B. , Maron Laurent
Published: March 2010

A theoretical investigation of the reductive oxo‐group silylation reaction of the uranyl dication held in a Pacman macrocylic environment has been carried out. The effect of the modeling of the Pacman ligand on the reaction profiles is found to be important, with the dipotassiation of a single oxo group identified as a key component in promoting the reaction between the SiX and uranium–oxo bonds. This reductive silylation reaction is also proposed to occur in an aqueous environment but was found not to operate on bare ions; in this latter case, substitution of a ligand in the equatorial plane was the most likely reaction. These results demonstrate the importance of the presence but not the identity of the equatorial ligands upon the silylation of the uranyl UO bond.
Small area estimation of poverty indicators
Authors: Molina Isabel , Rao J. N. K.
Published: March 2010

The authors propose to estimate nonlinear small area population parameters by using the empirical Bayes (best) method, based on a nested error model. They focus on poverty indicators as particular nonlinear parameters of interest, but the proposed methodology is applicable to general nonlinear parameters. They use a parametric bootstrap method to estimate the mean squared error of the empirical best estimators. They also study small sample properties of these estimators by model‐based and design‐based simulation studies. Results show large reductions in mean squared error relative to direct area‐specific estimators and other estimators obtained by “simulated” censuses. The authors also apply the proposed method to estimate poverty incidences and poverty gaps in Spanish provinces by gender with mean squared errors estimated by the mentioned parametric bootstrap method. For the Spanish data, results show a significant reduction in coefficient of variation of the proposed empirical best estimators over direct estimators for practically all domains. The Canadian Journal of Statistics 38: 369–385; 2010 © 2010 Statistical Society of Canada
The Venlafaxine “Heart Revenge:” A Short Report
Authors: Caroselli Costantino , Ricci Giorgio
Published: March 2010

A 40‐year‐old white woman with a history of venlafaxine abuse was admitted to our emergency department within 3 days after attempting suicide. On admission, blood pressure was 140/85 mm Hg with 70 beats per minute. The resting 12‐lead ECG showed a significant ST‐segment elevation in the anterolateral leads consistent with acute anterolateral myocardial infarction (anterolateral AMI). Noninvasive monitoring of blood oxygen saturation showed 97% while she was breathing room air. Laboratory findings showed the increase of troponin I up to 16 µg/L (normal range, 0–0.05 µg/L) and creatine kinase MB subunit levels up to 166 U/L (normal range, 0–25 U/L). An emergency coronary angiogram was normal. Venlafaxine is generally prescribed for the treatment of major depression, as well as, generalized and social anxiety. This is the first time in the literature that we describe an association between myocardial infarction and an overdose with venlafaxine. Copyright © 2010 Wiley Periodicals, Inc.
Human mesenchymal stem cells and their use in cell‐based therapies
Authors: Motaln Helena , Schichor Cristian , Lah Tamara T.
Published: March 2010

The human population is increasingly facing various diseases, including types of cancer, that cannot be cured with conventional drugs. Advanced drug targeting of tumor cells is also often impossible when treating highly invasive and infiltrative tumors such as glioblastoma or pulmonary cancer, because of tumor cells' high migration and invasiveness. Pluripotent human mesenchymal stem cells (hMSCs) have been extensively studied, and strategies are being proposed for treating “incurable” cancers and injury/disease‐affected organs. Because of their own intrinsic properties, involving homing and immunomodulatory potency, hMSCs could be used as an excellent cell/drug delivery vehicle in those cell‐based therapies. Their unprecedented use has been shadowed, however, by their spontaneous transformation, which links them to cancer‐initiating cells during tumor development. How malignant initiation proceeds in vivo, and what are the exact characteristics of the cancer‐initiating cells, still remain to be investigated. In the present review, the authors summed up the most recent knowledge about hMSC characteristics, their malignant transformation, and outlined the possibilities of their safe use in novel cell‐based therapies. Cancer 2010. © 2010 American Cancer Society.
Impact of chemotherapy on quality of life in patients with metastatic esophagogastric cancer
Authors: Al‐Batran Salah‐Eddin , Ajani Jaffer A.
Published: March 2010

BACKGROUND:

Health‐related quality of life (HRQoL) is a key issue in patients with metastatic esophagogastric cancer, a disease associated with survival times rarely exceeding 10 months. The objective of the current review was to evaluate the effects of chemotherapy on the HRQoL of patients with metastatic or locally advanced, inoperable esophagogastric cancer.

METHODS:

A systematic MEDLINE search was performed to address a predefined question list: Does chemotherapy improve or maintain HRQoL? Do available data favor a particular chemotherapy? What relation exists between HRQoL and the efficacy and tolerability of therapy?

RESULTS:

The majority of studies, including large randomized studies, indicated no significant improvements in mean HRQoL scores versus baseline after chemotherapy. However, scores were maintained and symptomatic relief or improved performance status was observed in many patients. HRQoL was maintained in approximately 50% of patients for up to 6 months but deteriorated in the remaining patients. In randomized phase 3 trials, only cisplatin/fluorouracil plus either docetaxel or epirubicin were found to provide superior HRQoL versus comparators. Between‐regimen differences in HRQoL scores appeared to correspond to differences in the efficacy rather than the toxicity of treatment regimens.

CONCLUSIONS:

Chemotherapy maintained HRQoL in a substantial proportion of patients with advanced esophagogastric cancer. This effect appeared to correspond to the efficacy of the treatment. Cancer 2010. © 2010 American Cancer Society.
An Anticipative Recursively Adjusting Mechanism for parallel file transfer in data grids
Authors: Yang Chao‐Tung , Yang Ming‐Feng , Chi Yao‐Chun , Hsu Ching‐Hsien
Published: March 2010

Data Grids enable the sharing, selection, and connection of a wide variety of geographically distributed computational and storage resources for content needed by large‐scale data‐intensive applications such as high‐energy physics, bioinformatics, and virtual astrophysical observatories. In Data Grids, co‐allocation architectures were developed to enable parallel downloads of data sets from selected replica servers. As Internet is usually the underlying network of a grid, network bandwidth plays as the main factor affecting file transfers between clients and servers. In this paradigm, there are still some challenges that need to be solved, such as to reduce differences in finish times between selected replica servers, to avoid traffic congestion resulting from transferring the same blocks in different links among servers and clients, and to manage network performance variations among parallel transfers. In this paper, we propose theAnticipative Recursively Adjusting Mechanism(ARAM) scheme to adjust the workloads on selected replica servers and handle unpredictable variations in network performance by those servers. Our algorithm is based on using the finish rates for previously assigned transfers to anticipate the bandwidth status for the next section to adjust workloads, and to reduce file transfer times in grid environments. Our approach is useful in grid environments with unstable network link. It not only reduces idle time wasted waiting for the slowest server, but also decreases file transfer completion times. Copyright © 2010 John Wiley & Sons, Ltd.
Assembly of Gold Nanoparticles on a Molecular Ultrathin Film: Tuning the Surface Plasmon Resonance
Authors: Rajesh K. , Sreedhar B. , Radhakrishnan T. P.
Published: March 2010

A number of methodologies for immobilizing metal nanoparticles in 2‐dimensional aggregate structures on various substrates, some with concomitant tuning of the surface plasmon resonance (SPR), have been reported. Many of them involve special functionalization of the nanoparticles, multiple fabrication steps or lengthy procedures. The present study demonstrates that monolayer Langmuir–Blodgett (LB) film of a hemicyanine‐based amphiphile with cationic headgroup is an easily fabricated platform for harnessing citrate‐stabilized gold nanoparticles. It is shown that a single immersion step can be used to immobilize the nanoparticles uniformly on large area films and that systematic variation of the immersion time from 10 min to 6 h leads to controlled assembly of the particles and tuning of the SPR band over ∼100 nm. A model for the structural reorganization in the LB film that facilitates the assembly of nanoparticles is presented and the advantages of the current methodology over earlier protocols are pointed out. The versatility of LB films in terms of the molecular level control of fabrication it enables and the variety of film structures that can be realized, point to the wide scope for future explorations, expanding upon the present observations.
Adsorption of Proline and Glycine on the TiO2(110) Surface: A Density Functional Theory Study
Authors: Tonner Ralf
Published: March 2010

The optimal adsorption modes for the amino acids glycine and proline on the ideal TiO2(110) surface are investigated by using density functional theory (PBE) applying periodic boundary conditions. Binding modes with anionic acid moieties bridging two titanium atoms after transferring a proton to the surface are the most stable configurations for both molecules investigated—similar to previous results for carboxylic acids. In contrast to the latter compounds, amino acids can form hydrogen bonds via the amino group towards the surface‐bound proton; this provides an additional stabilisation of 15–20 kJ mol−1. Zwitterionic binding modes are less stable (by 10–20 kJ mol−1) and are less important for proline. Neutral modes are energetically even less favourable. Calculations of vibrational frequencies and core‐level shifts complement the adsorption study and provide guidance for future experimental investigations. Control of the computational parameters is crucial for the derivation of accurate results. The layout and thickness of the slab model used are also shown to be decisive factors. Calculations with a different GGA‐functional (PW91) provide very similar relative energies, although the absolute energies change by about 20 kJ mol−1. Results derived with the hybrid functional PBE0 show an even greater stabilisation of the anionic binding modes with respect to the zwitterionic modes. A previously observed discrepancy between experimental and theoretical results for glycine could be solved, although the experimentally proposed free rotation of the CC bond could not be reproduced.
Intermediates in the Catalytic Cycle of [NiFe] Hydrogenase: Functional Spectroscopy of the Active Site
Authors: Pandelia Maria‐Eirini , Ogata Hideaki , Lubitz Wolfgang
Published: March 2010

The [NiFe] hydrogenase from the anaerobic sulphate reducing bacterium Desulfovibrio vulgaris Miyazaki F is an excellent model for constructing a mechanism for the function of the so‐called ‘oxygen‐sensitive’ hydrogenases. The present review focuses on spectroscopic investigations of the active site intermediates playing a role in the activation/deactivation and catalytic cycle of this enzyme as well as in the inhibition by carbon monoxide or molecular oxygen and the light‐sensitivity of the hydrogenase. The methods employed include magnetic resonance and vibrational (FTIR) techniques combined with electrochemistry that deliver information about details of the geometrical and electronic structure of the intermediates and their redox behaviour. Based on these data a mechanistic scheme is developed.
The Conformations of Amino Acids on a Gold(111) Surface
Authors: Hoefling Martin , Iori Francesco , Corni Stefano , Gottschalk Kay‐Eberhard
Published: March 2010

The interactions of amino acids with inorganic surfaces are of interest for biologists and biotechnologists alike. However, the structural determinants of peptide–surface interactions have remained elusive, but are important for a structural understanding of the interactions of biomolecules with gold surfaces. Molecular dynamics simulations are a tool to analyze structures of amino acids on surfaces. However, such an approach is challenging due to lacking parameterization for many surfaces and the polarizability of metal surfaces. Herein, we report DFT calculations of amino acid fragments in vacuo and molecular dynamics simulations of the interaction of all amino acids with a gold(111) surface in explicit solvent, using the recently introduced polarizable gold force field GolP. We describe preferred orientations of the amino acids on the metal surface. We find that all amino acids preferably interact with the gold surface at least partially with their backbone, underlining an unfolding propensity of gold surfaces.
In‐situ Scanning Transmission X‐Ray Microscopy of Catalytic Solids and Related Nanomaterials
Authors: de Groot Frank M. F. , de Smit Emiel , van Schooneveld Matti M. , Aramburo Luis R. , Weckhuysen Bert M.
Published: March 2010

The present status of in‐situ scanning transmission X‐ray microscopy (STXM) is reviewed, with an emphasis on the abilities of the STXM technique in comparison with electron microscopy. The experimental aspects and interpretation of X‐ray absorption spectroscopy (XAS) are briefly introduced and the experimental boundary conditions that determine the potential applications for in‐situ XAS and in‐situ STXM studies are discussed. Nanoscale chemical imaging of catalysts under working conditions is outlined using cobalt and iron Fischer–Tropsch catalysts as showcases. In the discussion, we critically compare STXM‐XAS and STEM‐EELS (scanning transmission electron microscopy–electron energy loss spectroscopy) measurements and indicate some future directions of in‐situ nanoscale imaging of catalytic solids and related nanomaterials.
Spatial Distribution of Acoustic Cavitation Bubbles at Different Ultrasound Frequencies
Authors: Ashokkumar Muthupandian , Lee Judy , Iida Yasuo , Yasui Kyuichi , Kozuka Teruyuki , Tuziuti Toru , Towata Atsuya
Published: March 2010

Images of sonoluminescence, sonophotoluminescence and sonochemiluminescence are recorded in order to semi‐quantitatively compare the spatial distribution of the cavitation activity at three different ultrasound frequencies (170 kHz, 440 kHz and 700 kHz) and at various acoustic amplitudes. At all ultrasound frequencies investigated, the sonochemically active cavitation zones are much larger than the cavitation zones where sonoluminescence is observed. Also, the sonochemically active bubbles are observed at relatively lower acoustic amplitudes than that required for sonoluminescence bubbles to appear. The acoustic power required for the observation of the initial cavitation bubbles increases with an increase in the ultrasound frequency. The cavitation bubbles are observed relatively uniformly throughout the reactor at 170 kHz whereas they are located away from the transducer at the higher frequencies used in this study. While these observations highlight the complexities involved in acoustic cavitation, possible reasons for the observed results are discussed.
High‐quality LaCoO3 single crystal grown by optical floating zone method and its electromagnetic properties
Authors: Song Gengxin , Li Liang , Xu Dapeng
Published: March 2010

A LaCoO3 single crystal with 4 mm in diameter and 30 mm in length has been grown by optical floating zone method. The as‐grown crystal is highly crystalline with the rhombohedral perovskite structure (R3c) and grows parallel to the (121) direction. The room temperature resistivity of the as‐grown crystal is 0.12 Ω·cm and the insulator‐metal transition occurs around 500 K. The coercivity and the remanence of the as‐grown crystal are 5 Oe and 6.61×10–5 μB/f.u. at 5 K, respectively. In 1000 Oe under zero‐field cooling, the magnetic susceptibility of the as‐grown crystal shows an upturn in a Curie tail fashion below 35 K, and appears a wave crest over the interval 55 K≤T≤90 K. In addition, a slope change of 1/χ(T) at about 12 K is observed in 50000 Oe under zero‐field cooling. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)