bluuebunny/crossref_metadata_2025 huggingface dataset:
Novel soft sensor modeling and process optimization technique for commercial petrochemical plant
Authors: Lahiri S. K. , Khalfe Nadeem M.
Published: October 2009

Soft sensors have been widely used in industrial process control to improve the quality of product and assure safety in production in real‐time basis. The core of a soft sensor is to construct a soft sensing model. This paper proposes a new soft sensing modeling method based on a recent advanced computational technique called support vector regression (SVR). The major advantage of the strategies is that soft sensor modeling can be conducted exclusively from the historic process data wherein the detailed knowledge of process phenomenology (reaction mechanism, kinetics, etc.) is not required.

Ultraviolet (UV) transmittance is one of the most important quality variables of monoethylene glycol (MEG) product that has impact on the polyester product quality. UV transmittance measures the presence of undesirable compounds in MEG that absorb light in the UV region of the spectrum and indirectly measures the impurity of MEG product. Off‐line laboratory method for MEG UV measurement is common practice among the manufacturer, where a sample is withdrawn several times a day from the product stream and analyzed by time‐consuming laboratory analysis. In the event of a process malfunction or operating under suboptimal condition, the plant continues to produce off‐specification (off‐spec) product until laboratory results become available. It results in enormous financial losses for a large‐scale commercial plant. In this paper, a soft sensor was developed to predict the UV transmittance on real‐time basis and an online hybrid SVR‐differential evolution (DE) technique was used to optimize the process parameters so that UV is maximized. This paper describes a systematic approach for the development of inferential measurements of UV transmittance using SVR analysis. After predicting the UV accurately, model inputs are optimized using DEs to maximize the UV. The optimized solutions when verified in actual commercial plant resulted in a significant improvement in the MEG quality. Copyright © 2009 Curtin University of Technology and John Wiley & Sons, Ltd.
Artificial neural network model with parameter tuning assisted by genetic algorithm technique: study of critical velocity of slurry flow in pipeline
Authors: Lahiri S. K. , Ghanta K. C.
Published: October 2009

This paper describes a robust hybrid artificial neural network (ANN) methodology, which can offer superior performance for important process engineering problems. The method incorporates hybrid artificial neural network and genetic algorithm technique (ANN–GA) for efficient tuning of ANN meta‐parameters. The algorithm has been applied for prediction of critical velocity of solid liquid slurry flow. A comparison with selected correlations in the literature showed that the developed ANN correlation noticeably improved prediction of critical velocity over a wide range of operating conditions, physical properties, and pipe diameters. Copyright © 2009 Curtin University of Technology and John Wiley & Sons, Ltd.
Stage-for-stage comparison of definitive chemoradiotherapy, surgery alone and neoadjuvant chemotherapy for oesophageal carcinoma
Authors: Morgan M A , Lewis W G , Casbard A , Roberts S A , Adams R , Clark G W B , Havard T J , Crosby T D L
Published: October 2009

Background

Definitive chemoradiotherapy (dCRT) has been proposed as an alternative therapy for selected patients with oesophageal cancer. The aim of this study was to determine the outcomes of dCRT, surgery alone, and neoadjuvant chemotherapy followed by surgery (CS) in patients with oesophageal cancer.

Methods

Consecutive patients diagnosed with oesophageal cancer and managed by a multidisciplinary team were staged by computed tomography and endoluminal ultrasonography. Those deemed unsuitable for surgery on the grounds of performance status, bulky local disease or personal choice received dCRT. The primary outcome measure was overall survival measured from date of diagnosis.

Results

Of 417 patients, 173 received dCRT, 126 underwent surgery alone and 118 received CS. The incidence of grade III/IV toxicity after dCRT and CS was 39·3 and 60·2 per cent respectively. Operative morbidity rates were 42·9 and 44·4 per cent after surgery alone and CS respectively. Thirty-day mortality rates were zero, 7·9 and 0·8 per cent after dCRT, surgery alone and CS respectively. Overall 2-year survival rates were 44·3, 56·2 and 42·4 per cent (P = 0·422).

Conclusion

These findings support the need for a randomized trial of dCRT versus CS for resectable oesophageal cancer.
Cost-effectiveness and quality-of-life analysis of physician-staffed helicopter emergency medical services
Authors: Ringburg A N , Polinder S , Meulman T J , Steyerberg E W , van Lieshout E M M , Patka P , van Beeck E F , Schipper I B
Published: October 2009

Background

The long-term health outcomes and costs of helicopter emergency medical services (HEMS) assistance remain uncertain. The aim of this study was to investigate the cost-effectiveness of HEMS assistance compared with emergency medical services (EMS).

Methods

A prospective cohort study was performed at a level I trauma centre. Quality-of-life measurements were obtained at 2 years after trauma, using the EuroQol—Five Dimensions (EQ-5D) as generic measure to determine health status. Health outcomes and costs were combined into costs per quality-adjusted life year (QALY).

Results

The study population receiving HEMS assistance was more severely injured than that receiving EMS assistance only. Over the 4-year study interval, HEMS assistance saved a total of 29 additional lives. No statistically significant differences in quality of life were found between assistance with HEMS or with EMS. Two years after trauma the mean EQ-5D utility score was 0·70 versus 0·71 respectively. The incremental cost–effectiveness ratio for HEMS versus EMS was €28 327 per QALY. The sensitivity analysis showed a cost-effectiveness ratio between €16 000 and €62 000.

Conclusion

In the Netherlands, the costs of HEMS assistance per QALY remain below the acceptance threshold. HEMS should therefore be considered as cost effective.
Long-term surveillance with computed tomography after endovascular aneurysm repair may not be justified
Authors: Black S A , Carrell T W G , Bell R E , Waltham M , Reidy J , Taylor P R
Published: October 2009

Background

There is a common perception that a large number of secondary interventions are needed following endovascular aortic aneurysm repair.

Methods

Prospective data were collected for a cohort of 417 consecutive elective patients undergoing infrarenal aortic endograft repair between April 2000 and May 2008. The rate of secondary interventions, associated morbidity and need for reintervention following surveillance imaging were analysed.

Results

The male : female ratio was 11 : 1, median age 76 (range 40–93) years and median aneurysm diameter 6·1 (5·3–11) cm. The overall 30-day mortality rate was 1·7 per cent (seven of 417). Secondary interventions were performed in 31 patients (7·4 per cent), of which six (1·4 per cent) were detected by surveillance. Endoleaks requiring reintervention occurred in 12 patients (2·9 per cent; ten type I and two type III endoleaks). Limb ischaemia secondary to graft occlusion occurred in 17 patients (4·1 per cent); extra-anatomical bypass was needed in 15 patients (3·6 per cent) and the remaining two had an amputation. Graft explantation following late infection was required in two patients (0·5 per cent).

Conclusion

Endoluminal repair of infrarenal aortic aneurysms can be performed with a low reintervention rate. The value of prolonged surveillance seems limited and current surveillance protocols may require revision.
Circumferential resection margin as a prognostic factor in rectal cancer
Authors: Bernstein T E , Endreseth B H , Romundstad P , Wibe A
Published: October 2009

Background

This study examined the prognostic impact of the circumferential resection margin (CRM) in patients with rectal cancer treated by total mesorectal excision (TME) with or without radiotherapy.

Methods

A national population-based rectal cancer registry included 3196 patients with known CRM status between 1993 and 2004. Some 90·5 per cent of the patients had surgery alone and 9·5 per cent had preoperative radiotherapy. Patients who did not have TME, those in whom the CRM was not measured, patients with intraoperative bowel or tumour perforation and those who received postoperative radiotherapy were excluded.

Results

Five-year local recurrence, distant metastasis and overall survival rates were 23·7, 43·9 and 44·5 per cent respectively for patients with a CRM of 0–2 mm, compared with 8·9, 21·7 and 66·7 per cent respectively for those with wider margins. A CRM of 2 mm or less had an impact on the prognosis of T2 and T3 tumours located 6–15 cm above the anal verge, but not on lower tumours. CRM also had a prognostic impact on the three endpoints in patients who received preoperative radiotherapy, but with less precision.

Conclusion

A CRM of 2 mm or less confers a poorer prognosis and patients should be considered for neoadjuvant treatment.
Recovery after ultrasound-guided foam sclerotherapy compared with conventional surgery for varicose veins
Authors: Darvall K A L , Bate G R , Adam D J , Bradbury A W
Published: October 2009

Background

The advantages of minimally invasive alternatives such as ultrasound-guided foam sclerotherapy (UGFS) over conventional surgery for the treatment of varicose veins include lower morbidity and faster recovery times. The aim was to compare morbidity, analgesia use, and time to return to driving and work following UGFS with those reported after conventional surgery for varicose veins.

Methods

Patients who had UGFS or surgery for varicose veins were sent a questionnaire 4 weeks after treatment.

Results

A total of 332 (84·9 per cent) of 391 patients who had UGFS and 53 (56 per cent) of 94 who had surgery returned a questionnaire. The groups were similar in terms of age, sex, and the proportion who had treatment of bilateral or recurrent veins. Patients who had surgery were more likely to have significant bruising (44 versus 7·2 per cent; P < 0·001) and pain (17 versus 5·5 per cent; P = 0·001). After UGFS, 43·2 per cent of patients returned to work within 24 h compared with none who had surgery (P < 0·001). Patients who had UGFS were more likely to return to driving within 4 days (P = 0·014).

Conclusion

UGFS was associated with less pain and analgesia requirement, time off work and quicker return to driving.
Medium-term results of ultrasound-guided foam sclerotherapy for small saphenous varicose veins
Authors: Darvall K A L , Bate G R , Silverman S H , Adam D J , Bradbury A W
Published: October 2009

Background

The results of surgery for small saphenous varicose vein (SSV) varicosities may be suboptimal in terms of recurrence and complications. The role of minimally invasive alternatives remains incompletely defined. The aim was to review the medium-term outcomes of ultrasound-guided foam sclerotherapy (UGFS) for SSV.

Methods

Eighty-six patients (92 legs) undergoing UGFS for SSV were assessed before, and 1, 6 and 12 months after treatment. Outcome measures were occlusion of, and abolition of reflux in, the SSV (technical success), absence of visible varicose veins (clinical success) and improvement in disease-specific health-related quality of life (HRQL) following treatment (Aberdeen Varicose Vein Symptom Severity Score (AVSS)).

Results

The technical and clinical success rates at 12 months were 91 and 93 per cent respectively; only three patients required a second treatment. After treatment of isolated SSV varicosities there was a significant improvement in AVSS, from a median of 19·0 (interquartile range 13·4–26·8) before treatment to 10·2 (4·0–18·3) and 9·7 (3·5–19·1) at 6 and 12 months respectively. The only complication was a popliteal vein thrombosis that required anticoagulation.

Conclusion

UGFS was an effective treatment for SSV, with abolition of reflux and visible varicose veins, and improvement in HRQL for at least 12 months.
Pathogenesis of primary varicose veins
Authors: Lim C S , Davies A H
Published: October 2009

Background

Valvular incompetence and reflux are common features of primary varicose veins, and have long been thought to be their cause. Recent evidence, however, suggests that changes in the vein wall may precede valvular dysfunction.

Methods

A literature search was performed using PubMed and Ovid using the keywords ‘varicose vein wall changes’, ‘pathogenesis’, ‘aetiology’ and ‘valvular dysfunction’. Articles discussing the pathophysiology of complications of varicose veins, such as ulceration, recurrence, thrombophlebitis and lipodermatosclerosis, were excluded.

Results and conclusion

Positive family history, age, sex and pregnancy are important risk factors for varicose vein formation. Areas of intimal hyperplasia and smooth muscle cell proliferation are often noted in varicose veins, although regions of atrophy are also present. The total elastin content in varicose as opposed to non-varicose veins is reduced; changes in overall collagen content are uncertain. Matrix metalloproteinases (MMPs), including MMP-1, MMP-2, MMP-3, MMP-7 and MMP-9, and tissue inhibitor of metalloproteinase (TIMP) 1 and TIMP-3 are upregulated in varicose veins. Activation of the endothelium stimulates the recruitment of leucocytes and the release of growth factors, leading to smooth muscle cell proliferation and migration. Dysregulated apoptosis has also been demonstrated in varicose veins. An understanding of the pathophysiology of varicose veins is important in the identification of potential therapeutic targets and treatment strategies.
Systematic review and meta-analysis of enteral nutrition formulations in acute pancreatitis
Authors: Petrov M S , Loveday B P T , Pylypchuk R D , McIlroy K , Phillips A R J , Windsor J A
Published: October 2009

Background

Although the benefits of enteral nutrition in acute pancreatitis are well established, the optimal composition of enteral feeding is largely unknown. The aim of the study was to compare the tolerance and safety of enteral nutrition formulations in patients with acute pancreatitis.

Methods

Electronic databases (Scopus, MEDLINE, Cochrane Controlled Clinical Trials Register) and the proceedings of major pancreatology conferences were searched.

Results

Twenty randomized controlled trials, including 1070 patients, met the inclusion criteria. None of the following was associated with a significant difference in feeding intolerance: the use of (semi)elemental versus polymeric formulation (relative risk (RR) 0·62 (95 per cent confidence interval (c.i.) 0·10 to 3·97); P = 0·611); supplementation of enteral nutrition with probiotics (RR 0·69 (95 per cent c.i. 0·43 to 1·09); P = 0·110); or immunonutrition (RR 1·60 (95 per cent c.i. 0·31 to 8·29); P = 0·583). The risk of infectious complications and death did not differ significantly in any of the comparisons.

Conclusion

The use of polymeric, compared with (semi)elemental, formulation does not lead to a significantly higher risk of feeding intolerance, infectious complications or death in patients with acute pancreatitis. Neither the supplementation of enteral nutrition with probiotics nor the use of immunonutrition significantly improves the clinical outcomes.
Supported liquid extraction in combination with LC‐MS/MS for high‐throughput quantitative analysis of hydrocortisone in mouse serum
Authors: Wu Shari , Li Wenkui , Mujamdar Tapan , Smith Tom , Bryant Matthew , Tse Francis L. S.
Published: October 2009

A high‐throughput LC–MS/MS bioanalytical method was developed and validated for the determination of hydrocortisone in mouse serum via supported liquid extraction (SLE) in a 96‐well plate format. Although sample extracts from SLE result in similar matrix effects compared with conventional liquid–liquid extraction (LLE), greater analyte extraction recovery and much higher analysis throughput for the quantitative analysis of hydrocortisone in mouse serum were obtained. The current LC‐MS/MS method was validated for a concentration range of 2.00–2000 ng/mL for hydrocortisone using a 0.100 mL volume of mouse serum. The intra‐ and inter‐day precision and accuracy of the quality control samples at low, medium and high concentration levels showed ≤12.9% CV and −3.4–6.2% bias for the analyte in mouse serum. Copyright © 2009 John Wiley & Sons, Ltd.
Analysing emission intensive firms as regulatory stakeholders: a role for adaptable business strategy
Authors: Martin Nigel , Rice John
Published: October 2009

Climate change regulations pose significant challenges to firms that produce large volumes of carbon emissions. Accordingly, firms in the trade‐exposed emission intensive industries are critical regulatory stakeholders. Following the Australian Government's ratification of the Kyoto Protocol in 2007, the proposed installation of an emission trading scheme is one of several business concerns as the government seeks to implement climate change policies and regulations. In this study, we inve stigate some of the major concerns that confront emission intensive businesses, and ask what the critical issues are for firms as a consequence of climate change policy implementation and what this means for their strategies. The study uses a concept mapping and analysis technique to reveal that future emission trading systems and business performance impacts resulting from emission reduction initiatives represent serious strategic concerns to stakeholder firms. Adaptable business strategies offer a potential solution to these perceived concerns and problems. Copyright © 2009 John Wiley & Sons, Ltd and ERP Environment.
Gossypium arboreum GHSP26 enhances drought tolerance in Gossypium hirsutum
Authors: Maqbool Asma , Abbas Waseem , Rao Abdul Qayyum , Irfan Muhammad , Zahur Muzna , Bakhsh Allah , Riazuddin Shiekh , Husnain Tayyab
Published: October 2009

Heat‐shock proteins (HSP) are molecular chaperones for protein molecules. These proteins play an important role in protein–protein interactions such as, folding and assisting in the establishment of proper protein conformation and prevention of unwanted protein aggregation. A small HSP gene GHSP26 present in Gossypium arboreum responds to dehydration. In the present study, an attempt was made to overcome the problem of drought stress in cotton. A cDNA of GHSP26 was isolated from G. arboreum, cloned in plant expression vector, pCAMBIA‐1301 driven by the cauliflower mosaic virus 35S promoter and introduced into Gossypium hirsutum. The integration and expression studies of putative transgenic plants were performed through GUS assay; PCR from genomic DNA, and quantitative real‐time PCR analysis. Transgenic cotton plants showed an enhanced drought tolerance, suggesting that GHSP26 may play a role in plant responsiveness to drought. © 2009 American Institute of Chemical Engineers Biotechnol. Prog., 2010
Hydroxycinnamic Acids as DNA‐Cleaving Agents in the Presence of CuII Ions: Mechanism, Structure–Activity Relationship, and Biological Implications
Authors: Fan Gui‐Juan , Jin Xiao‐Ling , Qian Yi‐Ping , Wang Qi , Yang Ru‐Ting , Dai Fang , Tang Jiang‐Jiang , Shang Ya‐Jing , Cheng Li‐Xia , Yang Jie , Zhou Bo
Published: October 2009

The effectiveness of hydroxycinnamic acids (HCAs), that is, caffeic acid (CaA), chlorogenic acid (ChA), sinapic acid (SA), ferulic acid (FA), 3‐hydroxycinnamic acid (3‐HCA), and 4‐hydroxycinnamic acid (4‐HCA), as pBR322 plasmid DNA‐cleaving agents in the presence of CuII ions was investigated. Compounds bearing o‐hydroxy or 3,5‐dimethoxy groups on phenolic rings (CaA, SA, and ChA) were remarkably more effective at causing DNA damage than the compounds bearing no such groups; furthermore, CaA was the most active among the HCAs examined. The involvement of reactive oxygen species (ROS) and CuI ions in the DNA damage was affirmed by the inhibition of the DNA breakage by using specific scavengers of ROS and a CuI chelator. The interaction between CaA and CuII ions and the influence of ethylenediaminetetraacetic acid (EDTA), the solvent, and pH value on the interaction were also studied to help elucidate the detailed prooxidant mechanism by using UV/Vis spectroscopic analysis. On the basis of these observations, it is proposed that it is the CaA phenolate anion, instead of the parent molecule, that chelates with the CuII ion as a bidentate ligand, hence facilitating the intramolecular electron transfer to form the corresponding CaA semiquinone radical intermediate. The latter undergoes a second electron transfer with oxygen to form the corresponding o‐quinone and a superoxide, which play a pivotal role in the DNA damage. The intermediacy of the semiquinone radical was supported by isolation of its dimer from the CuII‐mediated oxidation products. Intriguingly, CaA was also the most cytotoxic compound among the HCAs toward human promyelocytic leukemia (HL‐60) cell proliferation. Addition of exogenous CuII ions resulted in an effect dichotomy on cell viability depending on the concentration of CaA; that is, low concentrations of CaA enhanced the cell viability and, conversely, high concentrations of CaA almost completely inhibited the cell proliferation. On the other hand, when superoxide dismutase was added before, the two stimulation effects of exogenous CuII ions were significantly ameliorated, thus clearly indicating that the oxidative‐stress level regulates cell proliferation and death. These findings provide direct evidence for the antioxidant/prooxidant mechanism of cancer chemoprevention.
pH‐Modulated Watson–Crick Duplex–Quadruplex Equilibria of Guanine‐Rich and Cytosine‐Rich DNA Sequences 140 Base Pairs Upstream of the c‐kit Transcription Initiation Site
Authors: Bucek Pavel , Jaumot Joaquim , Aviñó Anna , Eritja Ramon , Gargallo Raimundo
Published: October 2009

Guanine‐rich regions of DNA are sequences capable of forming G‐quadruplex structures. The formation of a G‐quadruplex structure in a region 140 base pairs (bp) upstream of the c‐kit transcription initiation site was recently proposed (Fernando et al., Biochemistry, 2006, 45, 7854). In the present study, the acid–base equilibria and the thermally induced unfolding of the structures formed by a guanine‐rich region and by its complementary cytosine‐rich strand in c‐kit were studied by means of circular dichroism and molecular absorption spectroscopies. In addition, competition between the Watson–Crick duplex and the isolated structures was studied as a function of pH value and temperature. Multivariate data analysis methods based on both hard and soft modeling were used to allow accurate quantification of the various acid–base species present in the mixtures. Results showed that the G‐quadruplex and i‐motif coexist with the Watson–Crick duplex over the pH range from 3.0 to 6.5, approximately, under the experimental conditions tested in this study. At pH 7.0, the duplex is practically the only species present.
A Periodic Mesoporous Organosilica‐Based Donor–Acceptor System for Photocatalytic Hydrogen Evolution
Authors: Ohashi Masataka , Aoki Masao , Yamanaka Ken‐ichi , Nakajima Kiyotaka , Ohsuna Tetsu , Tani Takao , Inagaki Shinji
Published: October 2009

A new solid‐sate donor–acceptor system based on periodic mesoporous organosilica (PMO) has been constructed. Viologen (Vio) was covalently attached to the framework of a biphenyl (Bp)‐bridged PMO. The diffuse reflectance spectrum showed the formation of charge‐transfer (CT) complexes of Bp in the framework with Vio in the mesochannels. The transient absorption spectra upon excitation of the CT complexes displayed two absorption bands due to radical cations of Bp and Vio species, which indicated electron transfer from Bp to Vio. The absorption bands slowly decayed with a half‐decay period of approximately 10 μs but maintained the spectral shape, thereby suggesting persistent charge separation followed by recombination. To utilize the charge separation for photocatalysis, Vio–Bp–PMO was loaded with platinum and its photocatalytic performance was tested. The catalyst successfully evolved hydrogen with excitation of the CT complexes in the presence of a sacrificial agent. In contrast, reference catalysts without either Bp–PMO or Vio gave no or little hydrogen generation, respectively. In addition, a homogeneous solution system of Bp molecules, methylviologen, and colloidal platinum also evolved no hydrogen, possibly due to a weaker electron‐donating feature of molecular Bp than that of densely packed Bp in Bp–PMO. These results indicated that densely packed Bp and Vio are essential for hydrogen evolution in this system and demonstrated the potential of PMO as the basis for donor–acceptor systems suitable for photocatalysis.
From Byproducts to Efficient Fluorophores: A Route to the Synthesis of Fluorubines
Authors: Fleischhauer Jan , Beckert Rainer , Jüttke Yvonne , Hornig David , Günther Wolfgang , Birckner Eckhard , Grummt Ulrich‐W. , Görls Helmar
Published: October 2009

The reaction of bis(imidoyl) chlorides of oxalic acid with monoalkyl hydrazines leads to substituted Δ2‐1,2‐diazetines, which are versatile building blocks for ring‐transformation reactions. One remarkable product originating from side reactions featured by a strong orange/red fluorescence was confirmed as a novel fluorubine derivative. In continuing our studies to substituted oligoazaacenes, we developed several synthetic entries to build up novel fluorubine derivatives, in which particularly aminobridged bis(quinoxaline)s are the key products for cationic hexaazapentacenes. We would like to discuss the possible formation pathways of these fluorubine derivatives, which exhibit interesting photophysical and chemical properties. The structures of all new derivatives were confirmed by common analytical methods (NMR spectroscopy, CV, UV/Vis, mass spectrometry, elemental analysis, and X‐ray structural analysis) and will be discussed on selected examples in more detail.
[6,7]‐Heterocycle‐Fused 14‐Hydroxymorphinan Derivatives: Design, Synthesis, and Opioid Receptor Activity
Authors: Li Fuying , Yin Chenlei , Chen Jie , Liu Jinggen , Xie Xin , Zhang Ao
Published: October 2009

A series of new 14‐hydroxymorphinan analogues with a thiazole or imidazo[2,1‐b]thiazole fragment as the heterocyclic function fused to ring C were designed and synthesized. These compounds can be viewed as the result of a direct modification at ring C of the 14‐hydroxymorphinan scaffold. Among these compounds, three were identified as having potent binding affinity (∼1 nM) at both κ and μ receptors, and acting as agonists at κ and partial agonists or antagonists at μ receptors. In view of the promising results from studies on compounds with mixed κ and μ receptor activities, these new compounds warrant further investigation.
From Branched Networks of Actin Filaments to Bundles
Authors: Brill‐Karniely Yifat , Ideses Yaron , Bernheim‐Groswasser Anne , Ben‐Shaul Avinoam
Published: October 2009

Cross‐linking proteins can mediate the emergence of rigid bundles from a dense branched network of actin filaments. To enable their binding, the filaments must first bend towards each other. We derive an explicit criterion for the onset of bundling, in terms of the initial length of filaments L, their spacing b, and cross‐linker concentration f, reflecting the balance between bending and binding energies. Our model system contains actin, the branching complex Arp2/3 and the bundling protein fascin. In the first distinct stage, during which only actin and Arp2/3 are active, an entangled aster‐like mesh of actin filaments is formed. Tens of seconds later, when filaments at the aster periphery are long and barely branched, a sharp transition takes place into a star‐like structure, marking the onset of bundling. Now fascin and actin govern bundle growth; Arp2/3 plays no role. Using kinetic Monte Carlo simulations we calculate the temporal evolution of b and L, and predict the onset of bundling as a function of f. Our predictions are in good qualitative agreement with several new experiments that are reported herein and demonstrate how f controls the aster‐star transition and bundle length. We also present two models for aster growth corresponding to different experimental realizations. The first treats filament and bundle association as an irreversible sequence of elongation–association steps. The second, applicable for low f, treats bundling as a reversible self‐assembly process, where the optimal bundle size is dictated by the balance between surface and bending energies. Finally, we discuss the relevance of our conclusions for the lamellipodium to filopodia transition in living cells, noting that bundles are more likely nucleated by “tip complex” cross‐linkers (e.g. mDia2 or Ena/VASP), whereas fascin is mainly involved in bundle maintenance.
Coupled Modulated Bilayers: A Phenomenological Model
Authors: Hirose Yuichi , Komura Shigeyuki , Andelman David
Published: October 2009

We propose a model addressing the coupling mechanism between two spatially modulated monolayers. We obtain the mean‐field phase diagrams of coupled bilayers when the two monolayers have the same preferred modulation wavelength. Various combinations of the monolayer modulated phases are obtained and their relative stability is calculated. Due to the coupling, a spatial modulation in one of the monolayers induces a similar periodic structure in the second one. We have also performed numerical simulations for the case when the two monolayers have different modulation wavelengths. Complex patterns may arise from the frustration between the two incommensurate but annealed structures.
A Quantum Mechanical Study of the Second‐Order Nonlinear Optical Properties of Aryldiazenido‐Substituted Hexamolybdates: A Surprising Charge Transfer
Authors: Janjua Muhammad Ramzan Saeed Ashraf , Guan Wei , Liu Chun Guang , Muhammad Shabbir , Yan Likai , Su Zhongmin
Published: October 2009

The second‐order polarizabilities, transition moments, and density of states of aryldiazenido hexamolybdates derivatives were investigated by density functional theory (DFT). System 2 [Mo6O18(N2C6H5)]3– has a considerably large second‐order polarizability, 14.50 × 10–30 esu, and it is larger than that of system 1 [Mo6O18(N2C6H4NO2)]3– due to the absence of nitro group in the aryldiazenido ligand. The aryldiazenido ligand acts as an electron donor and the polyanion acts as an electron acceptor. The substitution of an amino(‐NH2) group in the ortho/para positions on the aryldiazenido segment leads to a substantially higher nonlinear optical (NLO) response. The introduction of an electron donor(‐NH2) in the ortho, meta, para, and ortho/para positions on the aryldiazenido ligand significantly enhances the second‐order polarizabilities of aryldiazenido hexamolybdates in comparison to the electron acceptor (‐NO2) as in system 1, because the electron‐donating ability was reasonably enhanced when the electron donor is attached to the aryldiazenido ligand. Furthermore, orbital analysis shows that incorporation of another phenyl (aromatic) ring in the aryldiazenido ligand leads to a maximum NLO response by reverting the direction and degree of charge transfer (CT), which might result from the C=C π‐conjugated bridge. System 8 [Mo6O18 (N2C14H11)]3– possesses a strikingly large and conspicuous static second‐order polarizability (βvec) computed to be 210.21 × 10–30 esu. The NLO response can be tuned by subtle changes in the aryldiazenido segment; the present investigation provides important insight into the NLO properties of (aryldiazenido) hexamolybdate derivatives.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
Hysteretic Gas Sorption in a Microporous Metal–Organic Framework with Nonintersecting 3D Channels
Authors: Seo Jinwoo , Chun Hyungphil
Published: October 2009

A permanently porous metal–organic framework (MOF) based on infinite chains of metal ions and angular dicarboxylate ligands was synthesized, and its unusual gas sorption properties were characterized. Zn2+ ions react with 2,7‐ndcH2 (2,7‐naphthalenedicarboxylic acid) to produce a double‐walled framework, [Zn(2,7‐ndc)]. The porous MOF possesses narrow channels in three perpendicular directions. Gas sorption studies using Ar, CO2, H2, N2, and O2 at various temperatures reveal that saturation isotherms show a stepwise adsorption and hysteresis loops that are highly unusual features for microporous materials. The unexpected gas sorption behavior of the microporous MOF is due to the unique arrangement of the pore channels and their narrow passages comparable to the critical dimensions of adsorptive gases. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2010)
Pyrene‐Functionalised Copper Complexes as Potential Dual‐Modality Imaging Agents
Authors: Holland Jason P. , Fisher Victoria , Hickin Jennie A. , Peach Josephine M.
Published: October 2009

The syntheses of pyrene‐functionalised bis(thiosemicarbazonato)zinc and ‐copper complexes are reported. In contrast to previously reported bis(thiosemicarbazonato)Cu2+ complexes which are nonfluorescent, the pyrene group remains highly fluorescent. The compounds have been characterised by using a wide range of techniques including reverse‐phase HPLC, cyclic voltammetry, NMR, electronic absorption (UV/Vis), infrared and fluorescence emission spectroscopy. Spectroelectrochemistry experiments demonstrated that the Cu2+ complexes undergo quasi‐reversible one‐electron reduction at biologically accessible potentials. Density functional theory calculations were used to probe the electronic structure of the pyrene‐functionalised copper complexes and confirmed that the ligand‐based fluorescent emission occurs due to the absence of orbital interactions between the pyrene and bis(thiosemicarbazonato)copper groups. These preliminary studies demonstrate that the new copper complexes have potential to be used as dual‐modality agents for in vitro cellular fluorescence microscopy and in vivo positron emission tomography experiments.
Separation of inorganic and small organic anions by CE using phosphonium‐based mono‐ and dicationic reagents
Authors: Křížek Tomáš , Breitbach Zachary S. , Armstrong Daniel W. , Tesařová Eva , Coufal Pavel
Published: October 2009

The separation of relatively small, fast‐migrating anions by CE is not possible under standard conditions with cathodic EOF of relatively high velocity. Therefore, separation approaches for these analytes usually include suppression or reversal of the EOF using various cationic additives to the BGE or covalent coating of the capillary walls. In this study, novel phosphonium‐based mono‐ and dicationic reagents (originally synthesized as ionic liquids) were evaluated as additives to the BGE for the separation of inorganic and small organic anions. The effects of these reagents on the EOF and their interactions with anionic analytes were compared. The effects of the additive's structure and concentration as well as the separation buffer pH have been studied. Propane‐1,3‐bis(tripropylphosphonium) fluoride proved to be the most effective additive, as it suppressed the EOF in the system and enabled remarkable manipulation of separation selectivity. A method for fast, reliable, and efficient separation of six inorganic and seven organic anions within 7 min time was developed using propane‐1,3‐bis(tripropylphosphonium) fluoride as an additive to the separation buffer.
Seed characters and testa sculptures of some Iranian Allium L. species (Alliaceae)
Authors: Neshati Fatemeh , Fritsch Reinhard M.
Published: October 2009

Seeds taken from herbarium specimens of 20 Allium taxa were investigated. The seeds of all species were black ranging from 1.7 mm (A. lamondiae) to 4 mm (A. altissimum and A. stipitatum) in length and 1 mm (A. lamondiae) to 3 mm (A. altissimum) in width. So, A. lamondiae had the smallest and A. altissimum the largest seeds. In the mean, the members of subg. Melanocrommyum had somewhat larger and the species of sect. Avulsea somewhat smaller seeds than most species belonging to other groups. The shape was generally ovate or variants of it and showed only slight differences between members of different sections.

The seed coat pattern was more variable. Most common were convex, granulate periclinal walls bearing several verrucae. Only A. borszczowii showed flat, densely granulate periclinal walls without verrucae, and A. bungei and A. joharchii had somewhat verruca‐like aggregating grana. The majority of the species investigated showed S‐like, rarely Omega‐like, undulated anticlinal walls with variable wavelengths and amplitudes. The testa cells of A. joharchii showed transitions to straight anticlinal walls. More or less straight anticlinal walls in A. kopetdagense, A. paradoxum, A. barsczewskii, and A. scabriscapum were connected with the presence of a strip‐like widened and transversally striated intercellular region covering these walls.

The seed coat pattern of most species corresponded well to earlier reports of the same or closely related species, or was at least already reported for not related Allium species. Only A. borszczowii and A. monophyllum displayed testa types earlier not reported. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Meta‐analysis of genome‐wide association studies: no efficiency gain in using individual participant data
Authors: Lin D. Y. , Zeng D.
Published: October 2009

To identify genetic variants with modest effects on complex human diseases, a growing number of networks or consortia are created for sharing data from multiple genome‐wide association studies on the same disease or related disorders. A central question in this enterprise is whether to obtain summary results or individual participant data from relevant studies. We show theoretically and numerically that meta‐analysis of summary results is statistically as efficient as joint analysis of individual participant data (provided that both analyses are performed properly under the same modeling assumptions). We illustrate this equivalence with case‐control data from the Finland‐United States Investigation of NIDDM Genetics (FUSION) study. Collating only summary results will increase the number and representativeness of available studies, simplify data collection and analysis, reduce resource utilization, and accelerate discovery. Genet. Epidemiol. 34:60–66, 2010. © 2009 Wiley‐Liss, Inc.
Burkitt lymphoma versus diffuse large B‐cell lymphoma: a practical approach
Authors: Bellan Cristiana , Stefano Lazzi , Giulia De Falco , Rogena Emily A , Lorenzo Leoncini
Published: October 2009

Burkitt Lymphoma (BL) is listed in the World Health Organization (WHO) classification of lymphoid tumours as an ‘aggressive B‐cell non‐Hodgkin's lymphoma’, characterized by a high degree of proliferation of the malignant cells and deregulation of the c‐MYC gene. The main diagnostic challenge in BL is to distinguish it from diffuse large B‐cell lymphoma (DLBCL). While in children BL and DLBCL types probably do not differ clinically, and the differential diagnosis between BL and DLBCL may theoretically appear clear‐cut, in adults daily practice shows the existence of cases that have morphological features, immunophenotypic and cytogenetics intermediate between DLBCL and BL, and cannot be classified with certainty in these categories. Distinguishing between BL and DLBCL is critical, as the two diseases require different management. This review summarizes the current practical approach, including the use of a large panel of antibodies, and cytogenetic and molecular diagnostic techniques, to distinguish between BL, DLBCL and the provisional category of ‘B‐cell lymphoma, unclassifiable, with features intermediate between diffuse large B‐cell lymphoma and Burkitt lymphoma’, now listed in the updated WHO classification. Copyright © 2009 John Wiley & Sons, Ltd.
Complementary use of fluorescence and magnetic resonance imaging of metastatic esophageal cancer in a novel orthotopic mouse model
Authors: Gros Stephanie J. , Dohrmann Thorsten , Peldschus Kersten , Schurr Paulus G. , Kaifi Jussuf T. , Kalinina Tatyana , Reichelt Uta , Mann Oliver , Strate Tim G. , Adam Gerhard , Hoffman Robert M. , Izbicki Jakob R.
Published: October 2009

We describe the development of an aggressive orthotopic metastatic model of esophageal cancer, which is visualized in real time with combined magnetic resonance imaging (MRI) and fluorescence imaging. The aim of the study was to describe the development of a novel model of metastatic tumor disease of esophageal carcinoma and use this model to evaluate fluorescence and MRI in early detection of local and metastatic disease. The human esophageal adenocarcinoma cell line PT1590 was stably transfected with green fluorescent protein (GFP). Nude mice were orthotopically implanted with PT1590‐GFP cells. Orthotopic tumor growth as well as metastatic spread was examined by fluorescence imaging and high‐resolution MRI at defined intervals after orthotopic implantation. Highly aggressive novel fluorescent cell lines were isolated from metastatic tissues and put into culture. After implantation of these cells, 100% of the animals developed orthotopic primary tumors. In 83% of animals, metastatic spread to liver, lung and lymph nodes was observed. Primary tumor growth could be visualized with fluorescence imaging and with MRI with high correlation between the 2 methods. Fluorescence imaging allows fast, sensitive, and economical imaging of the primary and metastatic tumor without anesthesia. With MRI, anatomical structures are visualized more precisely and tumors can be more accurately localized to specific organs. This model should prove highly useful to understand esophageal carcinoma and to identify novel therapeutics for this treatment‐resistant disease.
Frequent promoter hypermethylation of Wnt pathway inhibitor genes in malignant astrocytic gliomas
Authors: Götze Silke , Wolter Marietta , Reifenberger Guido , Müller Oliver , Sievers Sonja
Published: October 2009

Aberrant activation of wingless (Wnt) signaling is involved in the pathogenesis of various cancers. Recent studies suggested a role of Wnt signaling in gliomas, the most common primary brain tumors. We investigated 70 gliomas of different malignancy grades for promoter hypermethylation in 8 genes encoding members of the secreted frizzled‐related protein (SFRP1, SFRP2, SFRP4, SFRP5), dickkopf (DKK1, DKK3) and naked (NKD1, NKD2) families of Wnt pathway inhibitors. All tumors were additionally analyzed for mutations in exon 3 of the β‐catenin gene (CTNNB1). While none of the tumors carried CTNNB1 mutations, we found frequent promoter hypermethylation of Wnt pathway inhibitor genes, with at least one of these genes being hypermethylated in 6 of 16 diffuse astrocytomas (38%), 4 of 14 anaplastic astrocytomas (29%), 7 of 10 secondary glioblastomas (70%) and 23 of 30 primary glioblastomas (77%). Glioblastomas often demonstrated hypermethylation of 2 or more analyzed genes. Hypermethylation of SFRP1, SFRP2 and NKD2 each occurred in more than 40% of the primary glioblastomas, while DKK1 hypermethylation was found in 50% of secondary glioblastomas. Treatment of SFRP1‐, SFRP5‐, DKK1‐, DKK3‐, NKD1‐ and NKD2‐hypermethylated U87‐MG glioblastoma cells with 5‐aza‐2′‐deoxycytidine and trichostatin A resulted in increased expression of each gene. Furthermore, SFRP1‐hypermethylated gliomas showed significantly lower expression of the respective transcripts when compared with unmethylated tumors. Taken together, our results suggest an important role of epigenetic silencing of Wnt pathway inhibitor genes in astrocytic gliomas, in particular, in glioblastomas, with distinct patterns of hypermethylated genes distinguishing primary from secondary glioblastomas.
Protective effect of rosmarinic acid on V79 cells evaluated by the micronucleus and comet assays
Authors: Furtado Ricardo Andrade , de Araújo Felipe Rodrigues Rezende , Resende Flávia Aparecida , Cunha Wilson Roberto , Tavares Denise Crispim
Published: October 2009

Rosmarinic acid (RA) is a naturally occurring phenolic compound, which contributes to the beneficial and health‐promoting effects of herbs, spices and medicinal plants. RA has shown several biological activities, such as hepatoprotective, anti‐inflammatory, antiangiogenic, antitumor, antidepressant, antineurodegenerative, HIV‐1 inhibitory and antioxidant effects. The aim of this study was to investigate the ability of RA to prevent chemically induced chromosome breakage or loss and primary DNA damage using the micronucleus and comet assays with V79 cells, respectively. The chemotherapeutic agent doxorubicin (DXR; 0.5 µg ml−1) was used as the DNA‐damaging agent. The cultures were treated with different concentrations of RA (0.28, 0.56 and 1.12 mm) alone or in combination with DXR. The results showed that RA exerted no genotoxic effect, but significantly reduced the frequency of micronuclei and the extent of DNA damage induced by DXR at the three concentrations tested. The antioxidant activity of RA might be involved in the reduction of DXR‐induced DNA damage observed in the present study. Copyright © 2009 John Wiley & Sons, Ltd.
Theoretical study on HBO+ and HOB+ cations using multiconfiguration second‐order perturbation theory
Authors: Li Wen‐Zuo , Cheng Jian‐Bo , Li Qing‐Zhong , Gong Bao‐An , Sun Jia‐Zhong
Published: October 2009

The HBO+ and HOB+ cations have been reinvestigated using the CASSCF and CASPT2 methods in conjunction with the contracted atomic natural orbital (ANO) basis sets. The geometries of all stationary points in the potential energy surfaces were optimized at the CASSCF/ANO and CASPT2/ANO levels. The ground and the first excited states of HBO+ are predicted to be X2Π and A2Σ+ states, respectively. It was predicted that the ground state of HOB+ is X2Σ+ state. The A2Π state of HOB+ has unique imaginary frequency. A bending local minimum M1 was found for the first time along the 12A′′ potential energy surface and the A2Π state of HOB+ should be the transition state of the isomerization reactions for M1↔ M1. The CASPT2/ANO potential energy curves (PECs) of isomerization reactions were calculated as functions of the HBO bond angle. Many of the CASSCF and CASPT2 calculated results were different from the previously published QCISD(T) results. © 2009 Wiley Periodicals, Inc. J Comput Chem, 2010
Thrombin stimulates RPE cell proliferation by promoting c‐Fos‐mediated cyclin D1 expression
Authors: Parrales Alejandro , Palma‐Nicolás José Prisco , López Edith , López‐Colomé Ana María
Published: October 2009

The retinal pigment epithelium (RPE) plays an essential role in the maintenance and normal functioning of the neural retina. Alterations in RPE function are involved in several ocular pathologies involving the breakdown of the blood–retina barrier (BRB), which exposes RPE to serum components, thrombin among them. Our previous work has shown that thrombin stimulates the proliferation of RPE cells. We here analyzed the molecular pathways leading to this outcome, in order to support thrombin involvement in proliferative vitreoretinopathy (PVR), a major cause of retinal surgery failure. We demonstrated that thrombin activation of PAR‐1 promotes cyclin D1 expression at the transcriptional level by stimulating c‐Fos expression, mediated by PI3K, MAPK ERK1/2, and conventional PKC activity. Our results show that ERK activation is necessary but not sufficient for the induction of cyclin D1 expression and proliferation, since the inhibition of PI3K or cPKC prevents this outcome. Analysis of thrombin‐activated PAR‐1 downstream effectors demonstrated that c‐Fos expression by the sustained activation of ERK and c‐fos transcription triggers the expression and nuclear translocation of cyclin D1, a key regulator of cell cycle G1/S phase progression leading to proliferation. Evidence here provided contributes to the understanding of the mechanisms involved in proliferative eye diseases and enhances the possibility of controlling pathologies such as proliferative PVR, which eventually lead to blindness. J. Cell. Physiol. 222: 302–312, 2010. © 2009 Wiley‐Liss, Inc.