bluuebunny/crossref_metadata_2025 huggingface dataset:
Muscle strength and functional performance in patients with anterior cruciate ligament injury treated with training and surgical reconstruction or training only: A two to five‐year followup
Authors: Ageberg Eva , Thomeé Roland , Neeter Camille , Silbernagel Karin Grävare , Roos Ewa M.
Published: November 2008

Objective

To study muscle strength and functional performance in patients with anterior cruciate ligament (ACL) injury with or without surgical reconstruction 2 to 5 years after injury. Good muscle function is important in preventing early‐onset osteoarthritis (OA), but the role of reconstructive surgery in restoring muscle function is unclear.

Methods

Of 121 patients with ACL injury included in a randomized controlled trial on training and surgical reconstruction versus training only (the Knee, Anterior cruciate ligament, NON‐surgical versus surgical treatment [KANON] study, ISRCTN: 84752559), 54 (mean age at followup 30 years, range 20–39, 28% women) were assessed a mean ± SD of 3 ± 0.9 years after injury with reliable, valid, and responsive test batteries for strength (knee extension, knee flexion, leg press) and hop performance (vertical jump, one‐leg hop, side hop). The Limb Symmetry Index (LSI; injured leg divided by uninjured and multiplied by 100) value and absolute values were used for comparisons between groups (analysis of variance). An LSI ≥90% was considered normal.

Results

There were no differences between the surgical and nonsurgical treatment groups in muscle strength or functional performance. Between 44% and 89% of subjects had normal muscle function in the single tests, and between 44% and 56% had normal function in the test batteries.

Conclusion

The lack of differences between patients treated with training and surgical reconstruction or training only indicates that reconstructive surgery is not a prerequisite for restoring muscle function. Abnormal muscle function, found in approximately one‐third or more of the patients, may be a predictor of future knee OA.
Efficacy of wrist working splints in patients with rheumatoid arthritis: A randomized controlled study
Authors: Veehof M. M. , Taal E. , Heijnsdijk‐Rouwenhorst L. M. , van de Laar M. A. F. J.
Published: November 2008

Objective

To investigate the efficacy of wrist working splints after a period of splinting in patients with rheumatoid arthritis (RA).

Methods

We performed a 4‐week randomized controlled trial among 33 RA patients with wrist arthritis. Patients were randomly allocated to the splinting group (n = 17) or the control group (n = 16). Patients in the splinting group received a prefabricated wrist working splint and were instructed to use this splint as much as possible during the day. The primary outcome measure was average wrist pain during the past week, measured using a visual analog scale (VAS). Secondary outcome measures were grip strength and functional ability. The latter was measured using the Disabilities of the Arm, Shoulder, and Hand questionnaire and the short version of the Sequential Occupational Dexterity Assessment. Measurements were performed at baseline and after 4 weeks. Performance tests were performed without splint. Differences in change scores between the splinting and the control group were analyzed using analysis of covariance. To indicate the magnitude of the treatment effects, effect sizes were calculated.

Results

A large and highly significant treatment effect on wrist pain was found. VAS pain scores decreased by 32% in the splinting group and increased by 17% in the control group. Small and nonsignificant treatment effects were found with regard to nonsplinted grip strength and functional ability.

Conclusion

Prefabricated wrist working splints are highly effective in reducing wrist pain after 4 weeks of splint wearing in RA patients with wrist arthritis.
Arthritis‐related work transitions: A prospective analysis of reported productivity losses, work changes, and leaving the labor force
Authors: Gignac Monique A. M. , Cao Xingshan , Lacaille Diane , Anis Aslam H. , Badley Elizabeth M.
Published: November 2008

Objective

To prospectively examine arthritis‐related productivity losses, work changes, and leaving employment, the relationships among these work transitions, and the factors associated with them.

Methods

Participants with inflammatory arthritis or osteoarthritis were interviewed at 4 time points, 18 months apart, using a structured questionnaire. At baseline (T1), all participants (n = 490; 381 women, 109 men) were employed. At T2, T3, and T4, the sample decreased to 413, 372, and 349 participants, respectively. Respondents were recruited using community advertising and from rheumatology and rehabilitation clinics. Work transitions considered were productivity losses (absenteeism, job disruptions), work changes (reduced hours, changing jobs), and leaving employment. Also measured were demographic, illness, work context, and psychological variables. Generalized estimation equations modeled predictors of work transitions over time.

Results

Although 63.1% of respondents remained employed throughout the study, work transitions were common (reported by 76.5% of participants). Productivity losses, especially job disruptions such as being unable to take on extra work, were the most frequently reported. Work transitions were related to subsequently making other work transitions, including leaving employment. Age, sex, education, activity limitations, control, depression, and arthritis‐work spillover were also associated with work transitions.

Conclusion

This study sheds light on a process of diverse employment changes that may occur in the lives of many individuals with arthritis. It emphasizes the interrelationships among work transitions, as well as other factors in predicting work transitions, and it provides insight into work changes that may signal impending difficulties with remaining employed.
An ultrasonographic study of osteoarthritis of the hand: Synovitis and its relationship to structural pathology and symptoms
Authors: Keen Helen I. , Wakefield Richard J. , Grainger Andrew J. , Hensor Elizabeth M. A. , Emery Paul , Conaghan Philip G.
Published: November 2008

Objective

Few studies have examined hand osteoarthritis (OA) pathology using sensitive imaging techniques. The aim of this study was to determine the extent of ultrasound (US)–detected pathology and investigate its relationship with symptoms in hand OA.

Methods

Subjects with symptomatic hand OA and controls were recruited. All underwent clinical and US examination of the small joints of both hands and completed a range of measures of hand pain, stiffness, and function.

Results

Thirty‐six subjects with symptomatic OA and 19 control subjects with similar demographics were recruited. US‐detected pathology (osteophytes, joint space narrowing, gray‐scale synovitis, and power Doppler signal) occurred frequently in symptomatic hand OA (41%, 40%, 46%, and 7% of joints, respectively), and significantly less often in controls (P < 0.001 for all comparisons). Symptomatic joints were more likely to demonstrate US‐detected changes of gray‐scale synovitis, power Doppler signal, or osteophytes (P < 0.001, P = 0.002, and P < 0.001, respectively). Neither the number of affected joints per individual nor the summative semiquantitative scores for synovitis per individual correlated with symptoms (pain visual analog scale [VAS], global VAS, or Australian/Canadian Osteoarthritis Hand Index).

Conclusion

This study demonstrated extensive synovitis changes as well as the traditional structural radiographic findings of hand OA. Symptomatic joints were significantly more likely to demonstrate US‐detected structural changes or inflammation in symptomatic hand OA; however, the extent of changes in individual joints or in individuals did not correlate with the degree of symptoms, which may relate to both the assessment tools and the complex nature of pain.
Asymptotic behaviour of the finite‐time ruin probability in renewal risk models
Authors: Leipus Remigijus , Šiaulys Jonas
Published: November 2008

In this paper we study the tail behaviour of the probability of ruin within finite time t, as initial risk reserve x tends to infinity, for the renewal risk model with strongly subexponential claim sizes. The asymptotic formula holds uniformly for t∈[f(x), ∞), where f(x) is an infinitely increasing function, and substantially extends the result of Tang (Stoch. Models 2004; 20:281–297) obtained for the class of claim distributions with consistently varying tails. Two examples illustrate the result. Copyright © 2008 John Wiley & Sons, Ltd.
A Misclassification Model for the Non‐Disjunction Fraction in Meiosis I
Authors: Loschi Rosangela H. , Monteiro João V. D. , Souto Cristiane S.
Published: November 2008

In this paper we introduce a misclassification model for the meiosis I non‐disjunction fraction in numerical chromosomal anomalies named trisomies. We obtain posteriors, and their moments, for the probability that a non‐disjunction occurs in the first division of meiosis and for the misclassification errors. We also extend previous works by providing the exact posterior, and its moments, for the probability that a non‐disjunction occurs in the first division of meiosis assuming the model proposed in the literature which does not consider that data are subject to misclassification. We perform Monte Carlo studies in order to compare Bayes estimates obtained by using both models. An application to Down Syndrome data is also presented. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Bcl‐2, Raf‐1 and mitochondrial regulation of apoptosis
Authors: Wang Hong‐Gang , Reed John C.
Published: November 2008

Raf‐1 kinase was shown to bind via its catalytic domain (Cat) to Bcl‐2 in a BH4 domain‐dependent manner. Using a green fluorescent protein (GFP)‐Raf‐1 (Cat) fusion protein, Bcl‐2 but not Bcl‐2(Δ BH4) was found to target Raf‐1 to mitochondria in cells. Targeting Raf‐1 (Cat) to mitochondrial membranes by fusing with the transmembrane domain of an outer mitochondrial membrane protein protected cells from apoptosis and resulted in phosphorylation of BAD protein, whereas plasma‐membrane targeted Raf‐1 failed to phosphorylate BAD and did not protect against cell death. Moreover, a Bcl‐2 binding protein, BAG‐1, was shown to not only bind Raf‐1 but also increase the activity of this kinase through a protein—protein interaction. The findings suggest that Bcl‐2 targets Raf‐1 to mitochondria, allowing this kinase to contribute to cellular survival by phosphorylating BAD or possibly other protein substrates in the vicinity of Bcl‐2.
Specific interaction of methionine adenosyltransferase with free radicals
Authors: Avila M. A. , Corrales F. J. , Ruiz F. , Sánchez‐Góngora E. , Mingorance J. , Carretero M. V. , Mato J. M.
Published: November 2008

Although free radicals have been traditionally implicated in cell injury, and associated to pathophysiological processes, recent data implicate them in cell signaling events. Free radicals are naturally occurring oxygen‐, nitrogen‐ and sulfur‐derived species with an unpaired electron, such as superoxide, hydroxyl radical or nitric oxide. In order to assess the role of free radicals in cell signaling, we have studied the modulator effect of oxygen and nitrogen active species on liver methionine adenosyltransferase (MAT), a key metabolic enzyme. The presence of 10 cysteine residues per subunit, makes liver MAT a sensitive target for oxidation/nitrosylation. Here we show that purified MAT from rat liver is nitrosylated and oxidized in vitro. Incubation with H2O2 or the NO donor S‐nitrosylated GSH (GSNO), diminish MAT activity in a dose‐ and time‐dependent manner. Furthermore, the inactivation derived from both oxidation and nitrosylation, was reverted by GSH. MAT inactivation originates on the specific and covalent modification of the sulphydryl group of cysteine residue 121. We also studied how free radicals modulate MAT activity in vivo. It was previously shown that MAT activity is strongly dependent on cellular GSH levels. Generation of oxygen and nitrogen active species in rats by injection of LPS, induced a decrease of liver MAT activity. This effect might derive from nitrosylation and/or oxidation of the enzyme. Modulation of liver MAT by NO is further supported by the inactivation of this enzyme observed in experimental models in which NO is produced; such as the administration of NO donors to rats and in hepatocytes cultured in hypoxia, a condition that induces the expression of the inducible nitric oxide synthase (iNOS). Oxidation also controls liver MAT activity in a cell environment as shown in CHO cells stably transfected with rat liver MAT cDNA upon addition of H2O2 to the culture medium. This effect depends upon the generation of the hydroxyl radical. On the basis of the metabolic implications of liver MAT, together with the structural features accounting for the sensitivity of this enzyme to active oxygen and nitrogen species, we propose that modulation of MAT by these agents could be a mechanism to regulate the consumption of ATP in the liver, and thus preserve cellular viability under different stress conditions.
Catechin metabolites after intake of green tea infusions
Authors: Pietta P. G. , Simonetti P. , Gardana C. , Brusamolino A. , Morazzoni P. , Bombardelli E.
Published: November 2008

Green tea contains relatively large amounts of catechins, that have been recognized to be efficient free‐radical scavengers. In spite of a largely described antioxidant effect, the metabolic fate of catechins in humans has been scarcely studied. An infusion of green tea (about 400 mg of catechins) was given to healthy volunteers; plasma and urine samples were collected for 5 h and 2 days, respectively. Epigallocatechin gallate and epicatechin gallate were detected in plasma samples, reaching the maximum concentration (2 μM) at 2 h. Urine samples collected at 6–48 h contained detectable amounts of final catechin metabolites, including 4‐hydroxybenzoic acid, 3,4‐dihydroxybenzoic acid, 3‐methoxy‐4‐hydroxy‐hippuric acid and 3‐methoxy‐4‐hydroxybenzoic acid (vanillic acid). The total content of these metabolites averaged 60 mg. The levels of free plasma catechins account only partly for the increased (∼ +20%) total radical‐trapping antioxidant parameter (TRAP) detected after green tea intake. Catechin conjugates (glucuronide and sulphate) and metabolites may add further contribution and explain the measured TRAP increase.
Plasma antioxidants are strongly affected by iron‐induced lipid peroxidation in rats subjected to physical exercise and different dietary fats
Authors: Quiles José L. , Huertas Jesús R. , Mañas Mariano , Battino Maurizio , Ochoa Julio J. , Mataix JosÉ
Published: November 2008

Plasma is an important vehicle through which antioxidant molecules are conveyed and in which they may show different behaviors, either acting as a protective factor for oxidative damage to different blood elements or using it as a vehicle through which dietary antioxidant factors would be distributed to the body. The aim of the study was to determine the plasma level of vitamin E, coenzyme Q, uric acid and vitamin A and their relation with the cellular oxidative damage mediated by physical training and the ingestion of different fats (virgin olive and sunflower oils). Male Wistar rats were divided into 8 subgroups based on the dietary fat intake and their physical activity. Results show that both dietary fat and physical training affect susceptibility to iron‐induced lipid peroxidation in plasma and the tissues that were studied. The increase of this lipid peroxidation parallels a decrease of the level of all the plasma antioxidants that were studied.
Serum malondialdehyde in HIV‐seropositive children negatively correlates with CD4+ lymphocytes count
Authors: Jareño Enrique J. , Bosch‐Morell Francisco , Fernández‐Delgado Rafael , Donat Joaquín , Romero Francisco J.
Published: November 2008

Human immunodeficiency virus (HIV) infection is associated with oxidative stress as it has been demonstrated in adult‐seropositive individuals. We show in this study that serum malondialdehyde (MDA) concentration of HIV‐infected children was significantly higher than in control children. A negative correlation (r=‐0.515) was found in HIV‐infected children between their CD4+ lymphocyte count, and MDA concentration but not with serum antioxidant status. The increase of MDA concentration in HIV‐seropositive children confirms the involvement of oxidative stress in the pathophysiology of this infection also in childhood. Because of the importance of oxidative stress and antioxidants for HIV viral replication, the adequacy of an adjuvant therapy with antioxidants should be considered; an adequate candidate for it could be N‐acetyl‐cysteine.
Oxidant—antioxidant imbalance in blood of children with juvenile rheumatoid arthritis
Authors: Araujo V. , Arnal C. , Boronat M. , Ruiz E. , Domínguez C.
Published: November 2008

Juvenile rheumatoid arthritis (JRA) is the most commonly diagnosed rheumatic disease in children and may represent not a single disease, but rather a syndrome of diverse aetiologies in which inflammation is an exceedingly complex process. Oxidative free radical production at inflammation sites contributes to tissue damage and could also play a significant role in the pathogenesis of JRA. The aim of this study was to evaluate the antioxidant status and lipid peroxidation parameters related to the clinical form of JRA. Plasma malondialdehyde and hydroperoxide concentrations in children with polyarticular and systemic JRA subtypes were significantly higher than in controls. Plasma vitamin E and β‐carotene levels of the JRA children were lower in the three forms compared with healthy children. Patients with JRA present an imbalance in the oxidant—antioxidant system that manifests clearly in the polyarticular and systemic forms through an increase in lipoperoxidation products and significant decrease in the lipid‐soluble antioxidants vitamin E and β‐carotene.
Phenyl Cinnamate Derivatives from Oxalis pes‐caprae
Authors: DellaGreca Marina , Purcaro Raffaella , Previtera Lucio , Zarrelli Armando
Published: November 2008

During the screening of Mediterranean invasive plants, Oxalis pes‐caprae was identified as promising species. The fresh leaves and twigs of the plant were crumbled and extracted with AcOEt. The solution was concentrated, and separated into acidic and neutral fractions. The crude neutral residue was fractionated by chromatographic procedures, followed by structure elucidation on the basis of 1H‐ and 13C‐NMR, and MS data analysis, and six new phenyl cinnamate derivatives were identified. The phytotoxic effects of the isolated compounds on the germination and growth of the dicotyledon Lactuca sativa L. (lettuce) were studied in the concentration range from 10−4 to 10−7 M.
Furanocembranoids from the Soft Corals Sinularia asterolobata and Litophyton arboreum
Authors: Grote Daniela , Dahse Hans‐Martin , Seifert Karlheinz
Published: November 2008

The new cembranoid diterpene danielid (1) along with 3α‐ethoxyfuranocembranoid 2, pukalide (3), 13α‐acetoxypukalide (4), furanocembranoid 5, and furanosesquiterpene 6 have been isolated from the soft coral Sinularia asterolobata. The furanocembranoid diterpene 11β,12β‐epoxypukalide (7) and the sesquiterpene (−)‐bicyclogermacrene (8) have been obtained from the soft coral Litophyton arboreum. The structures were elucidated primarily by NMR spectroscopy. The furanocembranoids 2, 4, and 5 show good antiproliferative activities against the cell lines L‐929 and K‐562, and weak cytotoxic effects on HeLa cells.
Multivariate monitoring of water quality: a case study of Lake Simpele, Finland
Authors: Heikka Riitta Aulikki
Published: November 2008

Lake Simpele is located in South‐east Finland. The surface area of the lake, which consists of its eastern and western parts, is 97 km2. The wastewater treatment plant of the Parikkala municipality is situated between the two parts in Särkisalmi. The eastern part of the lake is more under the influence of agriculture (discharges from fields). The rather polluted bay Siikalahti is also located in the eastern part of the lake. The data for this study was obtained through obligatory monitoring measurements during the period 1974–2006. The seven water quality variables used in the classifications were the dissolved oxygen saturation degree C2‐sat. %, chemical oxygen demand CODMn, total phosphorus concentration, total nitrogen concentration, pH, electrical conductivity and colour. All of the time series of the eight sampling sites were used in the first classification with PCA. The dissolved oxygen saturation degree was not used as a variable in this classification, because the depth of the sampling sites varied a great deal. The sampling sites were put in order according to the pooled t‐values of the years 2000–2005. The t‐values of the studied decades were also pooled in order to examine the history of water quality in the different sampling sites. The changes in water quality were studied during the past three decades. Measures to protect the environment during the past decades have improved the quality of the water in Lake Simpele. The water quality of the western part of the lake has been and still is better than that of the eastern part. The epilimnion and hypolimnion were classified in one sampling site. The low dissolved oxygen saturation degree and total phosphorus concentration had a strong negative correlation. It could be seen how the low oxygen saturation degree releases phosphorus in the hypolimnion. Copyright © 2008 John Wiley & Sons, Ltd.
High Catalytic Efficiency of Nanostructured Molybdenum Trioxide in the Benzylation of Arenes and an Investigation of the Reaction Mechanism
Authors: Wang Feng , Ueda Wataru
Published: November 2008

The synthesis and characterization of nanostructured MoO3 with a thickness of about 30 nm and a width of about 450 nm are reported. The composition formula of the MP (precipitation method) precursor was estimated to be [(NH4)2O]0.169⋅MoO3⋅ (H2O)0.239. The calcination of the precursor in air afforded nanostructured pellets of the α‐MoO3 phase. The nanostructured MoO3 catalyst exhibited high efficiency in catalyzing the benzylation of various arenes with substituted benzyl alcohols, which were strikingly different to common bulk MoO3. Most reactions offered >99 % conversion and >99 % selectivity to monoalkylated compounds. MoO3 is a typical acid catalyst. However, the benzylation reaction over nanostructured MoO3 does not belong to the acid‐catalyzed type or defect site‐catalyzed type, since the catalyst has no acidity and defect site on surface. Characterization with thermal, spectroscopic, and electronic techniques reveal that the catalyst contains fully oxygen‐coordinated MoO6 octahedrons on the surface but partially reduced species (Mo5+) within the bulk phase. The terminal oxygen atoms of MoO bonds on the (010) basal plane resemble oxygen anion radicals and act as active sites for the adsorption and activation of benzyl alcohols by electrophilic attack. Such sites are indispensable for catalytic reactions since the blocking of these sites by electron acceptors, such as tetracyanoethylene (TCNE), can greatly decrease catalytic activity. This work represents a successful example of combining a heterogeneous catalysis study with nanomaterial synthesis.
Template‐Controlled Assembly of Ditopic Catechol Phosphines: A Strategy for the Generation of Complexes of Bidentate Phosphines with Different Bite Angles
Authors: Chikkali Samir H. , Gudat Dietrich , Lissner Falk , Niemeyer Mark , Schleid Thomas , Nieger Martin
Published: November 2008

A rational approach to the synthesis of heterobi‐ or ‐trimetallic complexes based upon self‐assembly of a flexible ditopic catechol‐phosphine ligand with [(cod)PdCl2] and simple metal halides such as GaCl3, BiCl3, SnCl4, or ZrCl4 is described. All products were characterized by spectroscopic and analytical data and single‐crystal X‐ray diffraction studies. The molecular structures can be described in terms of cis‐configured palladium complexes with supramolecular bisphosphine ligands that are formed by the assembly of two phosphine catecholate fragments on a main group/transition metal template. Of particular interest are the distinct decreases in P‐Pd‐P bite angles and P⋅⋅⋅P distances between the ligating atoms with increasing covalent radii of the templates. The range of these variations is of a magnitude similar to that of the geometrical changes in known families of complexes containing molecular bidentate ligands. Solution NMR studies give further evidence that in several cases the μ2‐bridging coordination of two of the catechol oxygen atoms in the template complexes is broken under the influence of donor solvents, thus allowing the supramolecular ligand to be switched between tetradentate ‐O2P2 and bidentate ‐P2 coordination modes.
Synthesis of Stable Aminoacyl‐tRNA Analogues Containing Triazole as a Bioisoster of Esters
Authors: Chemama Maryline , Fonvielle Matthieu , Arthur Michel , Valéry Jean‐Marc , Etheve‐Quelquejeu Mélanie
Published: November 2008

Stable analogues: An effective synthetic route involving cycloaddition between alkynes and azidonucleosides to afford a new class of stable aminoacyl‐tRNA analogues such as depicted is presented. Biological evaluation showed that theses new compounds act as potent inhibitors of FemXWv aminoacyl transferase, a novel drug target.

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Aminoacyl‐tRNAs have important roles in a variety of biological processes, including protein synthesis by ribosomes, targeting of proteins for degradation by the proteasome, and bacterial cell wall synthesis. Here we describe the synthesis of stable aminoacyl‐tRNA analogues containing 1,4‐ and 1,5‐substituted 1,2,3‐triazole rings. The procedure involves i) Cu‐ and Ru‐catalysed cycloadditions of 3′‐azidoadenosine and alkynes, which produced the 1,4 and 1,5 regioisomers of the triazoles, respectively, ii) coupling between the resulting triazole‐deoxyadenosine derivatives and a deoxycytidine phosphoramidite, and iii) the enzymatic ligation of the substituted dinucleotides with a 22 nt RNA microhelix that mimics the acceptor arm of tRNA. Nucleoside and nucleotide compounds were characterized by MS spectrometry and 1H, 31P and 13C NMR spectroscopy and were assayed for inhibition of FemXWv, an alanyltransferase essential for the formation of the peptidoglycan network of Gram‐positive bacterial pathogens. The low IC50 values obtained (2 to 4 μM) indicate that the five‐membered triazole rings acted as bioisosters of esters and can be used for the design of stable aminoacyl‐tRNA analogues.
Anion–π Slides for Transmembrane Transport
Authors: Mareda Jiri , Matile Stefan
Published: November 2008

The recognition and transport of anions is usually accomplished by hydrogen bonding, ion pairing, metal coordination, and anion–dipole interactions. Here, we elaborate on the concept to use anion–π interactions for this purpose. Different to the popular cation–π interactions, applications of the complementary π‐acidic surfaces do not exist. This is understandable because the inversion of the aromatic quadrupole moment to produce π‐acidity is a rare phenomenon. Here, we suggest that π‐acidic aromatics can be linked together to produce an unbendable scaffold with multiple binding sites for anions to move along across a lipid bilayer membrane. The alignment of multiple anion–π sites is needed to introduce a cooperative multi‐ion hopping mechanism. Experimental support for the validity of the concept comes from preliminary results with oligonaphthalenediimide (O‐NDI) rods. Predicted by strongly positive facial quadrupole moments, the cooperativity and chloride selectivity found for anion transport by O‐NDI rods were consistent with the existence of anion–π slides. The proposed mechanism for anion transport is supported by DFT results for model systems, as well as MD simulations of rigid O‐NDI rods. Applicability of anion–π slides to achieve electroneutral photosynthesis is elaborated with the readily colorizable oligoperylenediimide (O‐PDI) rods. To clarify validity, scope and limitations of these concepts, a collaborative research effort will be needed to address by computer modeling and experimental observations the basic questions in simple model systems and to design advanced multifunctional anion–π architectures.
Salt Effects on the Structure of Water Probed by Attenuated Total Reflection Infrared Spectroscopy and Molecular Dynamics Simulations
Authors: Riemenschneider Julian , Holzmann Jörg , Ludwig Ralf
Published: November 2008

We study aqueous solutions of alkaline chlorides (NaCl, KCl, RbCl and CsCl) with a combination of attenuated total reflection infrared (ATR‐IR) spectroscopy and molecular dynamics (MD) simulations using the TIP4P‐Ew water model (Horn et al.,J. Chem. Phys.2004,120, 9665), covering concentration ranges between 0.1 and 6 M. Spectral modifications in the OH stretch region are evaluated and correlated to the various salts and salt concentrations. By taking the difference spectra between the spectral line shapes of aqueous salt solutions and those of pure water, we specifically focus on the small quasi‐“free OH“ band appearing at the highest wavenumbers in the spectra. This free‐OH feature is found constantly at 3650 cm−1for all salts and salt concentrations, but it shows a characteristic intensity depending on the chosen cation. In the order from Na+to Cs+, the free OH intensity decreases compared to that of pure water. To interpret the experimental results, we performed MD simulations for similar salt solutions. The experimentally observed effects can be correlated with structural alterations indicated by differences between the site–site pair correlation functions of water in aqueous salt solutions and those of pure water.
Freezing and Melting of Water Confined in Silica Nanopores
Authors: Findenegg Gerhard H. , Jähnert Susanne , Akcakayiran Dilek , Schreiber Andreas
Published: November 2008

In nanosized pores, liquid water can be thermodynamically stable down to temperatures well below the limit of homogeneous nucleation of bulk water (∼235 K). Studies of water in such pores therefore offer an opportunity to reveal the anomalous behavior of deeply supercooled water. Herein we focus on recent studies of the limits of freezing and melting of water in the cylindrical pores of ordered mesoporous silicas with pore diameters in the range of 2–10 nm, based on vapor sorption measurements, calorimetric studies, NMR spectroscopy and cryoporometry, and neutron diffraction studies.
Induction of an antigen specific humoral immune response by immunization with the aggregate‐free human TGFα‐P64k fusion protein
Authors: Capote Ailem Rabasa , Gómez Pérez José A. , Hidalgo Greta Garrido , Hernández Liliet Matech , Gómez Iván Piñera , Ramírez Belinda Sánchez , Rodríguez Rolando Pérez , Vitlloch Adolfo Castillo , Molina Luis E. Fernández
Published: November 2008

Transforming growth factor alpha (TGFα) is an important epidermal growth factor receptor (EGFR) ligand. Over‐expression of both molecules in epithelial tumors has been correlated with poor prognosis and disease progression. Due to the importance of TGFα in tumorigenesis, this molecule has great potential for cancer immunotherapy. We previously designed a TGFα‐based vaccine consisting of a fusion protein between human TGFα (hTGFα) and P64k protein from Neisseria meningitidis expressed in Escherichia coli. However, this protein was obtained highly aggregated, which hampered its introduction into clinical use. In this study, we demonstrate that this aggregation state is not a consequence of IMAC purification, but is formed after bacterial disruption. To obtain this protein as a monomer, we designed a procedure that included an unfolding/refolding step at the end of purification. We verified that hTGFα in the refolded fusion protein (hTGFα‐P64k‐r) is immunogenic in mice. The latter was capable of inducing a humoral immune response against hTGFα identical to that generated with the aggregated fusion protein, demonstrating that the aggregation level has no influence on hTGFα immunogenicity. We also showed that TGFα‐directed antibodies induced apoptosis in A431 cells. The present results also validated the potential use of this vaccine in cancer patients with tumors overexpressing TGFα. Drug Dev Res 69 2008. © 2008 Wiley‐Liss, Inc.
Forest floor carbon dioxide fluxes within an upland‐peatland complex in the Western Boreal Plain, Canada
Authors: Solondz Danielle S. , Petrone Richard M. , Devito Kevin J.
Published: November 2008

This study examined the midday (10:00 to 16:00) growing season (April to October) surface cover CO2 relationships with different canopy closures in a forested upland–peatland–pond complex in the Western Boreal Plain (WBP), north‐central Alberta, Canada. Large differences were observed among the forest floors of landscape units with different canopy covers with respect to midday total respiration [(Rtot) = vegetation respiration (Rveg) + soil respiration (Rsoil)] and gross ecosystem production (GEP), and the seasonal pattern of GEP and Rtot. Highest rates of Rtot followed the general progression of riparian > upland > open peatland > covered peatland, with high Rsoil contributions. Strong correlations were observed between C:N, soil temperature, moisture and Rtot. Photosynthetic active radiation (PAR) controlled the GEP, which was highest in the open and covered peatland. GEP and Rtot were highest in the middle of the growing season when soil and air temperatures were warmest; in addition Rveg contributed more to Rtot during this time. However, Rsoil dominated the flux.

This study demonstrated that controlling environmental factors on CO2 exchange cannot necessarily be extrapolated among land cover units within a sub‐humid region, such as Canada's WBP. In addition, forest floors of different land cover units, and microtopography should be taken into account when discussing understory contributions to CO2 exchange. Copyright © 2008 John Wiley & Sons, Ltd.
The hydraulic structure of a raised bog and its implications for ecohydrological modelling of bog development
Authors: Baird Andrew J. , Eades Phil A. , Surridge Ben W. J.
Published: November 2008

Raised bogs are important ecohydrological systems in which there are strong two‐way links between plant succession, litter and peat decay, and hydrological functioning. Using recently established protocols, we measured the hydraulic structure of a raised bog in West Wales. We tested two hypotheses: (i) that the hydraulic conductivity (K) of the peat shows depth dependency such that lower layers of peat are effectively impermeable, and (ii) that the K of the marginal peat of the bog dome is lower than that in central areas. From 107 piezometer measurements we found there was depth dependency of K but that lower peat layers were not poorly permeable or impermeable. We also found that the K of the peat on the margin of the bog dome was generally significantly lower than that in central areas. Our results suggest that, for some bogs at least, it is important to simulate water flow through deeper peats when simulating peatland development or growth. They also raise the intriguing possibility that the low K of marginal peat is important in maintaining wet conditions in central bog areas, allowing bogs to reach greater thicknesses than they would do in the absence of the low‐K margin; an idea first proposed for blanket bogs by Lapen et al. (2005). Copyright © 2008 John Wiley & Sons, Ltd.
Voltammetric Sensing of Mercury and Copper Cations at Poly(EDTA‐like) Film Modified Electrode
Authors: Buica George O. , Bucher Christophe , Moutet Jean‐Claude , Royal Guy , Saint‐Aman Eric , Ungureanu Eleonora M.
Published: November 2008

Complexing polymer‐coated electrodes have been synthesized by oxidative electropolymerization of ethylenediamine tetra‐N‐(3‐pyrrole‐1‐yl)propylacetamide (monomer L). The presence of four polymerizable pyrrole fragments on the same EDTA skeleton was thought to confer enhanced rigidity and controlled dimensionality to the resulting complexing materials, which were used for the electrochemical detection of Hg(II), Cu(II), Pb(II) and Cd(II) ions by means of the chemical preconcentration‐anodic stripping technique. The polyamide electrode material showed particularly a significant selectivity towards mercury ions, even in the presence of a large excess of other metal cations. Moreover, the use of imprinted polymer‐coated electrodes prepared by electropolymerization of L in the presence of metal cations turned out to significantly improve the detection limits, down to 5×10−10 mol L−1 for Hg(II) and Cu(II) species.
Microfluidics: Applications for analytical purposes in chemistry and biochemistry
Authors: Ohno Ken‐ichi , Tachikawa Kaoru , Manz Andreas
Published: November 2008

In this review, we present recent advancements and novel developments in fluidic systems for applied analytical purposes in chemistry, biochemistry, and life science in general that employ and reflect the full benefits of microfluidics. A staggering rise in publications related to integrated, all‐in‐one microfluidic chips capable of separation, reaction, and detection have been observed, all of which realise the principal of micro total analysis systems or lab‐on‐a‐chip. These integrated chips actively adopt the scaling law concepts, utilising the highly developed fabrication techniques. Their aim is to multi‐functionalise and fully automate devices believed to assist the future advancements of point‐of‐care, clinical, and medical diagnostics.
Improved workup for glycosaminoglycan disaccharide analysis using CE with LIF detection
Authors: Hitchcock Alicia M. , Bowman Michael J. , Staples Gregory O. , Zaia Joseph
Published: November 2008

This work describes improved workup and instrumental conditions to enable robust, sensitive glycosaminoglycan (GAG) disaccharide analysis from complex biological samples. In the process of applying CE with LIF to GAG disaccharide analysis in biological samples, we have made improvements to existing methods. These include (i) optimization of reductive amination conditions, (ii) improvement in sensitivity through the use of a cellulose cleanup procedure for the derivatization, and (iii) optimization of separation conditions for robustness and reproducibility. The improved method enables analysis of disaccharide quantities as low as 1 pmol prior to derivatization. Biological GAG samples were exhaustively digested using lyase enzymes, the disaccharide products and standards were derivatized with the fluorophore 2‐aminoacridone and subjected to reversed polarity CE‐LIF detection. These conditions resolved all known chondroitin sulfate (CS) disaccharides or 11 of 12 standard heparin/heparan sulfate disaccharides, using 50 mM phosphate buffer, pH 3.5, and reversed polarity at 30 kV with 0.3 psi pressure. Relative standard deviation in migration times of CS ranged from 0.1 to 2.0% over 60 days, and the relative standard deviations of peak areas were less than 3.2%, suggesting that the method is reproducible and precise. The CS disaccharide compositions are similar to those obtained by our group using tandem MS. The reversed polarity CE‐LIF disaccharide analysis protocol yields baseline resolution and quantification of heparin/heparan sulfate and CS/dermatan sulfate disaccharides from both standard preparations and biologically relevant proteoglycan samples. The improved CE‐LIF method enables disaccharide quantification of biologically relevant proteoglycans from small samples of intact tissue.
Topology optimization of microfluidic mixers
Authors: Andreasen Casper Schousboe , Gersborg Allan Roulund , Sigmund Ole
Published: November 2008

This paper demonstrates the application of the topology optimization method as a general and systematic approach for microfluidic mixer design. The mixing process is modeled as convection dominated transport in low Reynolds number incompressible flow. The mixer performance is maximized by altering the layout of flow/non‐flow regions subject to a constraint on the pressure drop between inlet and outlet. For a square cross‐sectioned pipe the mixing is increased by 70% compared with a straight pipe at the cost of a 2.5 fold increase in pressure drop. Another example where only the bottom profile of the channel is a design domain results in intricate herring bone patterns that confirm findings from the literature. Copyright © 2008 John Wiley & Sons, Ltd.
Isolation and X‐Ray Structures of Reactive Intermediates of Organocatalysis with Diphenylprolinol Ethers and with Imidazolidinones
Authors: Seebach Dieter , Grošelj Uroš , Badine D. Michael , Schweizer W. Bernd , Beck Albert K.
Published: November 2008

Reaction of 2‐phenylacetaldehyde with the Me3Si ether of diphenyl‐prolinol, with removal of H2O, gives a crystalline enamine (1). The HBF4 salts of the MePh2Si ether of diphenyl‐prolinol and of 2‐(tert‐butyl)‐3‐methyl‐ and 5‐benzyl‐2,2,3‐trimethyl‐1,3‐imidazolidin‐4‐one react with cinnamaldehyde to give crystalline iminium salts 2, 3, and 4. Single crystals of the enamine and of two iminium salts, 2 and 3, were subjected to X‐ray structure analysis (Figs. 1, 2, and 6), and a 2D‐NMR spectrum of the third iminium salt was recorded (Fig. 7). The crystal and NMR structures confirm the commonly accepted, general structures of the two types of reactive intermediates in organocatalysis with the five‐membered heterocycles, i.e., D, E (Scheme 2). Fine details of the crystal structures are discussed in view of the observed stereoselectivities of the corresponding reactions with electrophiles and nucleophiles. The structures 1 and 2 are compared with those of other diphenyl‐prolinol derivatives (from the Cambridge File CSD; Table 1) and discussed in connection with other reagents and ligands, containing geminal diaryl groups and being used in enantioselective synthesis (Fig. 4). The iminium ions 3 and 4 are compared with N‐acylated imidazolidinones F and G (Figs. 9, 12, and 13, and Table 3), and common structural aspects such as minimalization of 1,5‐repulsion (the ‘A1,3‐effect’), are discussed. The crystal structures of the simple diphenyl‐prolinol⋅HBF4 salt (Fig. 3) and of Boc‐ and benzoyl‐(tert‐butyl)methyl‐imidazolidinone (Boc‐BMI and Bz‐BMI, resp.; Figs. 10 and 11) are also reported. Finally, the crystal structures are compared with previously published theoretical structures, which were obtained from high‐level‐of‐theory DFT calculations (Figs. 5 and 8, and Table 2). Delicate details including pyramidalization of trigonal N‐atoms, distortions around iminium CN bonds, shielding of diastereotopic faces, and the π‐interaction between a benzene ring and a Me group match so well with, and were actually predicting the experimental results that the question may seem appropriate, whether one will soon start considering to carry out such calculations before going to the laboratory for experimental optimizations.
Electrophilic S‐Trifluoromethylation of Cysteine Side Chains in α‐ and β‐Peptides: Isolation of Trifluoro‐methylated Sandostatin® (Octreotide) Derivatives
Authors: Capone Stefania , Kieltsch Iris , Flögel Oliver , Lelais Gerald , Togni Antonio , Seebach Dieter
Published: November 2008

The new electrophilic trifluoromethylating 1‐(trifluoromethyl)‐benziodoxole reagents A and B (Scheme 1) have been used to selectively attach CF3 groups to the S‐atom of cysteine side chains of α‐ and β‐peptides (up to 13‐residues‐long; products 7–14). Other functional groups in the substrates (amino, amido, carbamate, carboxylate, hydroxy, phenyl) are not attacked by these soft reagents. Depending on the conditions, the indole ring of a Trp residue may also be trifluoromethylated (in the 2‐position). The products are purified by chromatography, and identified by 1H‐, 13C‐, and 19F‐NMR spectroscopy, by CD spectroscopy, and by high‐resolution mass spectrometry. The CF3 groups, thus introduced, may be replaced by H (Na/NH3), an overall Cys/Ala conversion. The importance of trifluoromethylations in medicinal chemistry and possible applications of the method (spin‐labelling, imaging, PET) are discussed.
Further New Bis‐cembranoids from the Hainan Soft Coral Sarcophyton tortuosum
Authors: Jia Rui , Guo Yue‐Wei , Mollo Ernesto , Gavagnin Margherita , Cimino Guido
Published: November 2008

Two new bis‐cembranoids, ximaolides F (1) and G (2), were isolated from the Hainan soft coral Sarcophyton tortuosum. The structures and relative configurations of the two new compounds were elucidated by the combination of spectroscopic methods, chemical conversion of ximaolide F (1) into ximaolide G (2), and comparison with related model compounds.
Clintoniosides A – C, New Polyhydroxylated Spirostanol Glycosides from the Rhizomes of Clintonia udensis
Authors: Mimaki Yoshihiro , Watanabe Kazuki
Published: November 2008

Phytochemical analyses were carried out on the rhizomes of Clintonia udensis (Liliaceae) with particular attention paid to the steroidal glycoside constituents, resulting in the isolation of three new polyhydroxylated spirostanol glycosides, named clintonioside A (1), B (2), and C (3). On the basis of their spectroscopic data, including 2D‐NMR spectroscopy, in combination with acetylation and hydrolytic cleavage, the structures of 1–3 were determined to be (1β,3β,23S,24S,25R)‐1,23,24‐trihydroxyspirost‐5‐en‐3‐yl O‐β‐D‐glucopyranosyl‐(1→4)‐O‐[α‐L‐rhamnopyranosyl‐(1→2)]‐β‐D‐glucopyranoside (1), (1β,3β,23S,24S)‐3,21,23,24‐tetrahydroxyspirosta‐5,25(27)‐dien‐1‐yl O‐α‐L‐rhamnopyranosyl‐(1→2)‐O‐[β‐D‐xylopyranosyl‐(1→3)]‐β‐D‐glucopyranoside (2), and (1β,3β,23S,24S)‐21‐(acetyloxy)‐24‐[(6‐deoxy‐β‐D‐gulopyranosyl)oxy]‐3,23‐dihydroxyspirosta‐5,25(27)‐dien‐1‐yl O‐α‐L‐rhamnopyranosyl‐(1→2)‐O‐[β‐D‐xylopyranosyl‐(1→3)]‐β‐D‐glucopyranoside (3).
A New Alkaloid from Lycopodium japonicumThunb.
Authors: Sun Yun , Yan Jian , Meng Hao , He Chun‐Lin , Yi Ping , Qiao Ying , Qiu Ming‐Hua
Published: November 2008

A new alkaloid, miyoshianine C (1), was isolated from the whole plants of Lycopodium japonicum Thunb., together with the known four compounds α‐obscurine (2), lycodoline (3), miyoshianine A (4), and lucidioline (5). Their structures were elucidated on the basis of in‐depth spectroscopic analysis.
Eupatozansins A – C, Sesquiterpene Lactones from Eupatorium chinense var. tozanense
Authors: Liaw Chia‐Ching , Kuo Yao‐Haur , Hwang Tsong‐Long , Shen Ya‐Ching
Published: November 2008

Phytochemical investigation of Eupatorium chinense var. tozanense has resulted in the isolation of three new germacranolides, designated as eupatozansins A–C (1–3), along with five known compounds, (5S,6R,7R,8R)‐8‐angeloyloxy‐2‐oxoguaia‐1(10),3,11(13)‐trien‐12,6‐olide (4), costunolide (5), leptocarpin (6), 2α‐hydroxyeupatolide 8‐O‐angelate (7), and quercetin (8). The structures of the new compounds were identified by 1D and 2D NMR experiments, as well as high‐resolution mass spectrometry. The in vitro cytotoxic activities of compounds 1–8 were evaluated.
New Sesquiterpenes from Edible Fungus Clavicorona pyxidata
Authors: Zheng Yong‐Biao , Lu Chun‐Hua , Zheng Zhong‐Hui , Lin Xin‐Jian , Su Wen‐Jin , Shen Yue‐Mao
Published: November 2008

Three new sesquiterpenes, pyxidatol A–C (1–3, resp.), were obtained from the fermentation culture of Clavaria pyxidata, together with two known ones, tsugicoline E (4) and omphadiol (5). Their structures were elucidated through spectroscopic analyses, including 1D‐ and 2D‐NMR experiments, HR‐ESI‐Q‐TOF mass spectrometry, chemical correlation, and X‐ray single‐crystal diffraction.