bluuebunny/crossref_metadata_2025_split huggingface dataset:
Novel tolerance interval model for the estimation of the shelf life of pharmaceutical products
Authors: Komka Kinga , Kemény Sándor , Bánfai Balázs 
Published: April 2010

AbstractThe main objective of the stability study of pharmaceutical products is to estimate the shelf life indicated on the container label. For the determination of the label shelf life the International Conference on Harmonisation (ICH) Guideline recommends the confidence interval approach, but its adequacy is questionable. Instead of the current regulation, several proposals are known in the literature applying the tolerance interval approach. The aim of our paper is to extend the tolerance interval model assuming two distinct influence sources, namely the tablet‐to‐tablet variability and the analytical measurement error. Another main concept in the paper is that the tolerance interval is constructed for the true (and not for the measured) assay content. Investigating the influence of several factors on the width of the tolerance interval, a simulation is performed applying different number of samples and repeated analysis, as well as different variance components regarding the tablet‐to‐tablet variability and the analytical measurement error. An example is also given to illustrate the difference between the former and the proposed tolerance interval models and to compare them with the present regulation of the ICH. Copyright © 2010 John Wiley & Sons, Ltd.
Principles of Proper Validation: use and abuse of re‐sampling for validation
Authors: Esbensen Kim H. , Geladi Paul 
Published: April 2010

AbstractValidation in chemometrics is presented using theexemplarcontext of multivariate calibration/prediction. A phenomenological analysis of common validation practices in data analysis and chemometrics leads to formulation of a set of generic Principles of Proper Validation (PPV), which is based on a set of characterizing distinctions: (i) Validation cannot be understood by focusing on the methods of validation only; validation must be based on full knowledge of the underlying definitions, objectives, methods, effects and consequences—which are all outlined and discussed here. (ii) Analysis of proper validation objectives implies that there is one valid paradigm only: test set validation. (iii) Contrary to much contemporary chemometric practices (and validationmyths), cross‐validation is shown to be unjustified in the form of monolithic application of a one‐for‐all procedure (segmented cross‐validation) on all data sets. Within its own design and scope, cross‐validation is in reality a sub‐optimalsimulationof test set validation, crippled by a critical sampling variance omission, as it manifestly is based on one data set only (training data set). Other re‐sampling validation methods are shown to suffer from the same deficiencies. The PPV are universal and can be applied to all situations in which the assessment of performance is desired: prediction‐, classification‐, time series forecasting‐, modeling validation. The key element of PPV is the Theory of Sampling (TOS), which allow insight into all variance generating factors, especially the so‐called incorrect sampling errors, which, if not properly eliminated, are responsible for a fatal inconstant sampling bias, for which no statistical correction is possible. In the light of TOS it is shown how a second data set (test set, validation set) is critically necessary for the inclusion of the sampling errors incurred in all ‘future’ situations in which the validated model must perform. Logically, therefore, all one data set re‐sampling approaches for validation, especially cross‐validation and leverage‐corrected validation, should be terminated, or at the very least used only with full scientific understanding and disclosure of their detrimental variance omissions and consequences. Regarding PLS‐regression, an emphatic call is made for stringent commitment to test set validation based on graphical inspection of pertinentt–uplots for optimal understanding of theX–Yinterrelationships and for validation guidance. QSAR/QSAP forms a partial exemption from the present test set imperative with no generalization potential. Copyright © 2010 John Wiley & Sons, Ltd.
RuII Multinuclear Metallosupramolecular Rack‐Type Architectures of Polytopic Hydrazone‐Based Ligands: Synthesis, Structural Features, Absorption Spectra, Redox Behavior, and Near‐Infrared Luminescence
Authors: Stadler Adrian‐Mihail , Puntoriero Fausto , Nastasi Francesco , Campagna Sebastiano , Lehn Jean‐Marie 
Published: April 2010

AbstractA novel class of polytopic hydrazone‐based ligands was synthesized. They gave heteroleptic RuII polynuclear rack‐like complexes of formula [Runterpyn(bridging molecular strand)]2n+ (terpy=2,2′:6′,2′′‐terpyridine). The new rack‐like systems can be viewed as being made of two identical or roughly identical peripheral subunits separated by several similar metal‐containing spacer subunits. The presence of pyrazine or pyrimidine units within the molecular multitopic strands introduces additional chemical diversity: whereas a pyrimidine unit leads to appended orthogonal subunits that are on the same side with regard to the main molecular strand, a pyrazine unit leads to orthogonal subunits that lie on different sides. Mixing pyrazine and pyrimidine units within the same (bridging) molecular strand also allows peculiar and topographically controlled geometries to be obtained. Redox studies provided evidence that each species undergoes reversible redox processes at mild potentials, which can be assigned to specific subunits of the multicomponent arrays. Non‐negligible electronic coupling takes place among the various subunits, and some electron delocalization extending over the overall bridging molecular strand takes place. In particular, oxidation data suggest that the systems can behave as p‐type “molecular wires” and reduction data indicate that n‐type electron conduction can occur within the multimetallic framework. All the multinuclear racks exhibit 3MLCT emission, both at 77 K in rigid matrix and at 298 K in fluid solution, which takes place in the near‐infrared region (emission maxima in the 1000–1100 nm region), and is quite structured. Rigidity of the molecular structures and delocalization within the large bridging ligands are proposed to contribute to the occurrence of the rather uncommon MLCT infrared emission, which is potentially interesting for optical communication devices.
A Flexible Approach to Azasugars: Asymmetric Total Syntheses of (+)‐Castanospermine, (+)‐7‐Deoxy‐6‐epi‐castanospermine, and (+)‐1‐epi‐Castanospermine
Authors: Liu Gang , Wu Tian‐Jun , Ruan Yuan‐Ping , Huang Pei‐Qiang 
Published: April 2010

AbstractThe asymmetric total synthesis of natural azasugars (+)‐castanospermine, (+)‐7‐deoxy‐6‐epi‐castanospermine, and synthetic (+)‐1‐epi‐castanospermine has been accomplished in nine to ten steps from a common chiral building block (S)‐8. The method features a powerful chiral relay strategy consisting of a highly diastereoselective vinylogous Mukaiyama‐type reaction with either chiral or achiral aldehydes (≥95 % de; de=diastereomeric excess) and a diastereodivergent reduction of tetramic acids, which allows formation of three continuous stereogenic centers with high diastereoselectivities. The method also provides a flexible access to structural arrays of 5‐(α‐hydroxyalkyl)tetramic acids, such as 17/34, and 5‐(α‐hydroxyalkyl)‐4‐hydroxyl‐2‐pyrrolidinones, such as 18 and 25/35 a. The method constitutes the first realization of the challenging chiral synthons A and D and thus of the conceptually attractive retrosynthetic analysis shown in Scheme 1 in a highly enantioselective manner.
Steric and Electronic Influence on Photochromic Switching of N,C‐Chelate Four‐Coordinate Organoboron Compounds
Authors: Amarne Hazem , Baik Chul , Murphy Stephen K. , Wang Suning 
Published: April 2010

AbstractA four‐coordinate organoboron compound B(ppy)Mes2 (1, ppy=2‐phenylpyridyl, Mes=mesityl) was previously found to undergo reversible photochromic switching through the formation/breaking of a CC bond, accompanied by a dramatic color change from colorless to dark blue. To understand this unusual phenomenon, a series of new four‐coordinate boron compounds based on the ppy‐chelate ligand and its derivatives have been synthesized. In addition, new N,C‐chelate ligands based on benzo[b]thiophenylpyridine and indolylpyridine have also been synthesized and their boron compounds were investigated. The crystal structures of most of the new compounds were determined by X‐ray diffraction analysis. UV/Vis, NMR, and electrochemical methods were used to monitor the photoisomerization process. DFT calculations were performed for all compounds to understand the photophysical and electronic properties of this class of molecules. The results of our study showed that the bulky mesityl group is necessary for photochromic switching. Electron‐donating and electron‐withdrawing groups on the ppy chelate have a distinct impact on the photoisomerization rate and the photochemical stability of the molecule. Furthermore, we have found that the non‐ppy‐based N,C‐chelate ligands such as benzo[b]thiophenepyridyl can also promote photoisomerization of the boron chromophore in the same manner as the ppy chelate, but the product is thermally unstable.
Construction of 2,3‐Dihydrofuran Cores through the [3+2] Cycloaddition of Gold α‐Carbonylcarbenoids with Alkenes
Authors: Li Chia‐Wen , Lin Guan‐You , Liu Rai‐Shung 
Published: April 2010

AbstractTreatment of 2‐epoxy‐1‐alkynylbenzenes with electron‐rich alkenes and a [AuCl(PR3)]/AgX catalyst in CH2Cl2 led to the formation of 2‐alkenyl‐1‐(2,3‐dihydrofuran‐4‐yl)benzenes. This transformation comprises of a gold‐catalyzed redox reaction to form a gold α‐carbonylcarbenoid initially, which then reacts in situ with an alkene in a [3+2] cycloaddition. A range of alkenes are amenable to this tandem reaction, amongst them α‐substituted styrenes, enol ethers, and 2,3‐dimethylbutadienes. Deuterium‐labeling experiments suggest a stepwise mechanism for the α‐carbonylcarbenoid/alkene [3+2] cycloaddition. The resulting 2,3‐dihydrofuran products allow access to diverse oxacyclic compounds through a stereoselective ene–oxonium reaction initiated by treatment with HOTf (1 mol %; Tf=trifluoromethanesulfonyl). A stepwise pathway is proposed for this reaction. The feasibility for direct transformation of 2‐alkenyl‐1‐alkynylbenzenes into the desired 2,3‐dihydrofuran products through initial m‐chloroperbenzoic acid oxidation, followed by the addition of gold catalyst and alkene, has also been demonstrated.
A delay‐dependent robust fuzzy MPC approach for nonlinear CSTR
Authors: Chen Qiu‐Xia , Yu Li 
Published: April 2010

AbstractBased on Takagi–Sugeno (T–S) fuzzy models, a robust fuzzy model predictive control (MPC) algorithm is presented for a class of nonlinear time‐delay systems with input constraints. Delay‐dependent sufficient conditions for the robust stability of the closed‐loop system are derived, and the condition for the existence of the fuzzy model predictive controller is formulated in terms of nonlinear matrix inequality via the parallel distributed compensation (PDC) approach. By using a novel matrix transform technique, a receding optimization problem with linear matrix inequality (LMIs) constraints is constructed to design the desired controllers with an on‐line optimal receding horizon guaranteed cost. Finally, an example of continuous stirred tank reactors (CSTR) is given to demonstrate the effectiveness of the proposed results.
Bubble shape, gas flow and gas–liquid mass transfer in pulp fibre suspensions
Authors: Ishkintana L. K. , Bennington C. P. J. 
Published: April 2010

AbstractGas–liquid mass transfer in pulp fibre suspensions in a batch‐operated bubble column is explained by observations of bubble size and shape made in a 2D column. Two pulp fibre suspensions (hardwood and softwood kraft) were studied over a range of suspension mass concentrations and gas flow rates. For a given gas flow rate, bubble size was found to increase as suspension concentration increased, moving from smaller spherical/elliptical bubbles to larger spherical‐capped/dimpled‐elliptical bubbles. At relatively low mass concentrations (Cm = 2–3% for the softwood and Cm ≅ 7% for the hardwood pulp) distinct bubbles were no longer observed in the suspension. Instead, a network of channels formed through which gas flowed. In the bubble column, the volumetric gas–liquid mass transfer rate, kLa, decreased with increasing suspension concentration. From the 2D studies, this occurred as bubble size and rise velocity increased, which would decrease overall bubble surface area and gas holdup in the column. A minimum in kLa occurred between Cm = 2% and 4% which depended on pulp type and was reached near the mass concentration where the flow channels first formed.
Polycyclic aromatic hydrocarbons (PAHs) adsorption on solid surfaces applied to waste lubricant oils recovery process
Authors: Filho José Lima Assunção , de Moura Lyzette Gonçalves Moraes , Ramos Antonio Carlos da Silva 
Published: April 2010

AbstractLubricant oils undergo degradation increasing polycyclic aromatic hydrocarbons (PAHs) concentration. In this work, PAHs adsorption onto activated carbon, powder silica, and powder chitosan surfaces was estimated, with their concentrations in organic solvents (ethanol, 2‐propanol, 1‐butanol, and terc‐butanol) monitored by UV‐visible absorption. Equilibrium concentration was attained after 72 h and the isotherms presented characteristic of multilayer formation. The greater surface density was determined for the chitosan, but the system containing activated carbon and 1‐butanol presented better efficiency for PAHs removal. Results indicated that the adsorption evaluated in this work can be a potential stage in the waste lubricant oils global recovery process.
A simple method for identifying bubbling/jetting regimes transition from large submerged orifices using electrical capacitance tomography (ECT)
Authors: Cai Qingbai , Shen Xuesong , Shen Chunyin , Dai Gance 
Published: April 2010

AbstractThe bubbling–jetting transition regimes from large orifice submerged in water were investigated for various orifice diameters. A simple and fast way for identifying the regime transition was successfully developed using electrical capacitance tomography (ECT). In all the experiments deionised water was liquid phase and air was gas phase. Orifice gas velocity (VN) and orifice diameter (do) were varied from 0.8 to 186 m/s and 4–21 mm, respectively. It was found that the VN,trans. strongly depends on the orifice diameter. In the small orifice diameter (do < 10 mm), VN,trans. greatly decreases with the increase of orifice diameter. However, in the large orifice diameter (do > 10 mm), the effect of orifice diameter on the transition velocity is insignificant. Finally, the data obtained by ECT compares with other works and the dimensionless orifice Reynolds number (Reo ∼11,000) is preferred to identify the bubbling–jetting transition regimes.
Inverted‐Takotsubo Pattern Cardiomyopathy Secondary to Pheochromocytoma: A Clinical Case and Literature Review
Authors: Kim Stephen , Yu Anthony , Filippone Lea A. , Kolansky Daniel M. , Raina Amresh 
Published: April 2010

AbstractTakotsubo cardiomyopathy is an increasingly recognized clinical syndrome of transient left ventricular dysfunction, commonly with apical ballooning, in the context of physical or emotional stress. Recently, an inverted‐Takotsubo contractile pattern has been described with hypokinesis of the basal and mid‐ventricular segments and sparing of the apex. We report a case of a 30‐year‐old man presenting with transient left ventricular dysfunction in an inverted‐Takotsubo contractile pattern, associated with a newly discovered pheochromocytoma, and present a literature review of the inverted‐Takotsubo contractile pattern cardiomyopathy. Copyright © 2010 Wiley Periodicals, Inc.
Should We Measure C‐reactive Protein on Earth or Just on JUPITER?
Authors: Bajpai Ambareesh , Goyal Abhinav , Sperling Laurence 
Published: April 2010

AbstractEvidence for the role of inflammation in the pathogenesis of atherosclerosis is compelling and has generated interest in high‐sensitivity C‐reactive protein (hs‐CRP) as a marker of cardiovascular risk. Data regarding hs‐CRP and cardiovascular risk, though largely consistent, is of unclear clinical relevance. Most recently, the Justification for the Use of Statins in Primary Prevention: An Intervention Trial Evaluating Rosuvastatin (JUPITER) trial has led to further debate regarding the utility of hs‐CRP. This article provides a comprehensive review of the data regarding cardiovascular risk and hs‐CRP with an emphasis on the JUPITER trial and concludes with an evidence‐based analysis of the current role of hs‐CRP in cardiovascular risk assessment. Copyright © 2010 Wiley Periodicals, Inc.
Cardiovascular Manifestations in Patients With Thrombotic Thrombocytopenic Purpura: A Single‐center Experience
Authors: Gandhi Kaushang , Aronow Wilbert S. , Desai Harit , Amin Harshad , Sharma Mala , Lai Hoang M. , Singh Parminder 
Published: April 2010

AbstractBackgroundCardiovascular manifestation in patients with thrombotic thrombocytopenic purpura.HypothesisThe aim of this study was to investigate the incidence of acute myocardial infarction (AMI), arrhythmias, congestive heart failure, and mortality in patients hospitalized for thrombotic thrombocytopenic purpura (TTP).MethodsThirty‐eight patients (27 women and 11 men), mean age 44 years, were hospitalized with the diagnosis of TTP confirmed by a hematologist. We investigated the incidence of AMI which developed during hospitalization for TTP. AMI was diagnosed by new electrocardiographic changes, increased serum cardiac troponin I levels, and clinical symptomatology. The patients with AMI were also monitored for development of arrhythmias during hospitalization.ResultsOf the 38 patients, 8 (21%) developed new Q‐wave AMI. There was no significant difference in baseline characteristics between patients who developed AMI and those who did not develop AMI. Of the 8 patients with AMI, 2 (25%) developed atrial fibrillation, 1 (13%) developed atrial flutter, 1 (13%) developed supraventricular tachycardia, and 2 (25%) developed congestive heart failure. Death occurred in 3 of 8 patients (38%) with AMI and in 1 of 30 patients (3%) without AMI (P < 0.01).ConclusionsNew Q‐wave AMI developed in 21% of 38 patients hospitalized with TTP. Supraventricular tachyarrhythmias developed in 50% of 8 patients with TTP who developed AMI. Patients hospitalized for TTP should be monitored for adverse cardiac events due to the high incidence of new AMI, supraventricular tachyarrhythmias, and mortality. Copyright © 2010 Wiley Periodicals, Inc.
Changes in Inflammatory Biomarkers in Patients Treated With Ticagrelor or Clopidogrel
Authors: Husted Steen , Storey Robert F. , Harrington Robert A. , Emanuelsson Håkan , Cannon Christopher P. 
Published: April 2010

AbstractBackgroundInflammation is a key factor in the development of atherosclerotic disease and acute coronary syndromes (ACS). The P2Y12 receptor antagonists ticagrelor (AZD6140) and clopidogrel may have anti‐inflammatory effects. The objective of this analysis from the Dose Confirmation Study Assessing Anti‐Platelet Effects of AZD6140 vs Clopidogrel in NSTEMI 2 (DISPERSE 2) trial was to compare ticagrelor and clopidogrel for effects on the inflammatory biomarkers C‐reactive protein (CRP), interleukin 6 (IL‐6), myeloperoxidase (MPO), and soluble CD40 ligand (sCD40L).HypothesisTicagrelor inhibits the P2Y12 receptor and inflammation to a greater extent than clopidogrel in nonST‐segment elevation ACS (NSTE‐ACS) patients.MethodsIn a double‐blind, double‐dummy, multicenter trial, 990 patients who had been hospitalized within the previous 48 hours with NSTE‐ACS were randomized to receive ticagrelor 90 mg twice daily, ticagrelor 180 mg twice daily, or clopidogrel 300 mg initially and then 75 mg once daily. Within the ticagrelor groups, patients were also randomized to receive or not receive a loading dose of ticagrelor 270 mg initially. All patients received standard treatment for ACS, which included 325 mg aspirin initially and 75 to 100 mg aspirin each day subsequently. Inflammatory biomarkers were measured at baseline, upon hospital discharge, and after 4 weeks.ResultsInflammatory biomarker measurements were not significantly different among treatment groups at baseline, discharge, and 4 weeks.ConclusionsTicagrelor and clopidogrel appeared not to differ in this study with respect to the inflammatory biomarkers CRP, IL‐6, MPO, and sCD40L in patients with NSTE‐ACS. Copyright © 2010 Wiley Periodicals, Inc.
Long‐term Outcome of Patients Treated With Prophylactic Nesiritide for the Prevention of Acute Kidney Injury Following Cardiovascular Surgery
Authors: Lingegowda Vijaykumar , Van Quoc C. , Shimada Michiko , Beaver Thomas M. , Dass Bhagwan , Sood Puneet , Ahsan Ejaz A. 
Published: April 2010

AbstractBackgroundPreviously, we reported that the prophylactic use of nesiritide did not reduce the incidence of dialysis or death following cardiovascular (CV) surgery despite reducing the incidence of acute kidney injury (AKI) in the immediate postoperative period. Therefore, we investigated whether the observed renal benefits of nesiritide had any long‐term impact on cumulative patient survival and renal outcomes.MethodsParticipants of the Nesiritide Study, a previously reported prospective, double‐blind, placebo‐controlled, randomized clinical trial investigating the effect of nesiritide on the incidence of dialysis or death at 21 days in adult patients undergoing high‐risk CV surgery, were included in the study. Data of the participants' most recent health and renal function status were obtained using institutional review board‐approved patient questionnaires, medical records, and the database of the Social Security Administration.ResultsData on all 94 patients from the Nesiritide Study were obtained. The mean follow‐up period was 20.8 ± 10.4 months. No differences in cumulative survival between the groups were noted at follow‐up (nesiritide 77.7% vs placebo 81.6%,P= 0.798). Patients with in‐hospital incidence of AKI had a higher rate of mortality than those with no AKI (AKI 41.4% vs no AKI 10.7%,P= 0.002). However, differences in survival time were not significant between the groups when the analysis was restricted to patients with AKI (nesiritide 16.8 ± 4 months vs placebo 18.5 ± 2.3 months,P= 0.729).ConclusionsRenoprotection provided by nesiritide in the immediate postoperative period was not associated with improved long‐term survival in patients undergoing high‐risk CV surgery. Copyright © 2010 Wiley Periodicals, Inc.