bluuebunny/crossref_metadata_2025 huggingface dataset:
Replication initiation and DNA topology: The twisted life of the origin
Authors: Rampakakis E. , Gkogkas C. , Di Paola D. , Zannis‐Hadjopoulos M.
Published: March 2010

Genomic propagation in both prokaryotes and eukaryotes is tightly regulated at the level of initiation, ensuring that the genome is accurately replicated and equally segregated to the daughter cells. Even though replication origins and the proteins that bind onto them (initiator proteins) have diverged throughout the course of evolution, the mechanism of initiation has been conserved, consisting of origin recognition, multi‐protein complex assembly, helicase activation and loading of the replicative machinery. Recruitment of the multiprotein initiation complexes onto the replication origins is constrained by the dense packing of the DNA within the nucleus and unusual structures such as knots and supercoils. In this review, we focus on the DNA topological barriers that the multi‐protein complexes have to overcome in order to access the replication origins and how the topological state of the origins changes during origin firing. Recent advances in the available methodologies to study DNA topology and their clinical significance are also discussed. J. Cell. Biochem. 110: 35–43, 2010. © 2010 Wiley‐Liss, Inc.
Pneumatically assisted desorption/ionization: 1. Some thoughts on the possible ionization mechanism(s)
Authors: Zivolic Fabio , Zancanaro Flavio , Favretto Donata , Ferrara Santo Davide , Seraglia Roberta , Traldi Pietro
Published: March 2010

We have observed that spraying solvent droplets on a zopiclone tablet produced MH+ ions also in the absence of any electrical field and without the addition of organic acids to the sprayed solvent. The choice of a drug tablet as test bench has been done for the signal stability, higher than that observed when the drug is directly placed on a stainless steel surface. This behavior indicates that the formation of MH+ ions is mainly due to pneumatical effects and the results are discussed with respect to those obtained by other research groups. Different mechanisms contributing to MH+ production under these conditions are proposed and discussed. The local heating of the solvent thin layer present on the surface has been calculated and the small temperature increase (and the consequent small decrease of pKa value) suggests that this effect can play only a minor role. However, different solvents have been employed for studying this aspect and, quite surprisingly, the best results have been obtained with acetonitrile (ACN). Experiments performed by spraying CD3CN showed again the formation of MH+ and not MD+, and this excludes the role of ACN as protonating medium. A further thought was stimulated by the behavior observed by varying the sheath gas (N2) flow, showing that the MH+ ion intensity increases by increasing the flow. Side effects related to the highest kinetic energy of the spraying droplets can be considered, but an active role of N2 in the MH+ formation could be taken into account, by considering the possible ionization of N2 by collisional phenomena. The N2+• ions could undergo a charge–exchange reaction with analyte molecules leading to a short‐lived odd electron ion which behaves as protonating media for neutral molecules. The above‐described mechanism does not require either the presence of electrical fields nor the addition of organic acid to the sprayer solvent and can give a rationale for what was observed when only pneumatical conditions are employed. Copyright © 2010 John Wiley & Sons, Ltd.
A Raman spectroscopic study on the allocation of ammonium adsorbing sites on H2Ti3O7 nanofibre and its structural derivation during calcination
Authors: Liu Hongwei , Zheng Zhanfeng , Yang Dongjiang , Waclawik Eric , Ke Xuebin , Zhu Huaiyong , Palmer Sara , Frost Ray L.
Published: March 2010

The adsorption behaviour of ammonium ions and the structural features of layered proton trititanate were characterised by using Raman spectroscopy, X‐ray diffraction (XRD) and transmission electron microscopy. It revealed that the intensity of the Raman band at 309 cm−1, assigned to very long TiO bonds (0.22 nm), reduced, whereas the band at 890 cm−1, assigned to very short TiO bonds (0.17 nm), increased slightly after the adsorption of ammonium ions (NH4+). The adsorption of ammonium ions enlarged the interlayer distance of the (200) plane. Ammonium ions were located at the corner of the TiO6 octahedral slabs. This was further confirmed by XRD, with an increased intensity of the (201) plane being observed. Copyright © 2010 John Wiley & Sons, Ltd.
Far‐infrared spectroscopy, the wavenumbers of metal–ligand vibrations and the characterisation of inorganic pigments
Authors: Clark Robin J. H.
Published: March 2010

Extensive far‐infrared studies of inorganic materials and pigments in the early 1960s are highlighted and related to the many subsequent Raman studies of the same materials, studies which led to the formulation of Raman spectral libraries for use in conservation science. The need for complementary infrared/far‐infrared libraries is recognised. Copyright © 2010 John Wiley & Sons, Ltd.
Multidetector computed tomography for preoperative prediction of postsurgical prognosis of patients with extrahepatic biliary cancer
Authors: Kobayashi Shogo , Nagano Hiroaki , Marubashi Shigeru , Wada Hiroshi , Eguchi Hidetoshi , Takeda Yutaka , Tanemura Masahiro , Kim Tonsok , Doki Yuichiro , Mori Masaki
Published: March 2010

Background

Preoperative prognostic information to select a treatment strategy is important especially in patients who need highly aggressive surgery, such as those with biliary cancer. We evaluated various prognostic factors and non‐curative surgical factors using multidetector computed tomography (MDCT).

Methods

We retrospectively analyzed 71 patients who underwent MDCT preoperatively and were scheduled for surgical resection of biliary cancer. For MDCT diagnosis, we used MDCT‐based classification equivalent to the surgical and pathological classification of the Japanese Society of Biliary Surgery. We evaluated MDCT‐related prognostic factors and non‐curative surgical factors and compared these factors with pathological results.

Results

MDCT‐diagnosed category T (primary tumor invasion) included both prognostic factors and non‐curative surgical factors but not category N (lymph node metastasis). Multivariate analysis identified MDCT‐based suspected arterial invasion as an independent prognostic factor. In patients suspected of arterial invasion by MDCT, the 3‐year overall survival rate was only 39% and the curative resection ratio was only 33%, because of the high positive surgical dissected margin.

Conclusion

MDCT‐based suspected arterial invasion is a predictor of poor prognosis after surgery for biliary cancer and represents a non‐curative surgical factor associated with positive dissected margin. J. Surg. Oncol. 2010; 101:376–383. © 2010 Wiley‐Liss, Inc.
Is FDG‐PET suitable for evaluating neoadjuvant therapy in non‐small cell lung cancer? Evidence with systematic review of the literature
Authors: Rebollo‐Aguirre Ángel C. , Ramos‐Font Carlos , Villegas Portero Román , Cook Gary J.R. , Llamas Elvira José Manuel , Romero Tabares Antonio
Published: March 2010

Background

Neoadjuvant therapy response assessment is crucial in patients with non‐small cell lung cancer (NSCLC). FDG‐PET has emerged as a valuable tool for defining therapy response assessment in other tumours.

Aim

To systematically review publications appearing in the literature describing induction therapy response assessment with FDG‐PET in NSCLC.

Methods

We performed a bibliographic search and selected only prospective studies in order to include the highest levels of evidence.

Results

Nine of 497 potentially relevant publications were selected. The ranges of sensitivity, specificity, positive predictive value and negative predictive value for primary tumour response assessment were 80–100%, 0–100%, 42.9–100%, and 66.7–100%, respectively. Pooling data for N2 restaging after neoadjuvant response the overall sensitivity was 63.8% (95% CI, 53.3–73.7%) and overall specificity was 85.3% (95% CI, 80.4–89.4%).

Conclusion

The results of the analysis do not support the use of FDG‐PET as the only re‐assessment tool for mediastinal lymph node evaluation for routine clinical use. FDG‐PET seems to predict primary tumour response to induction therapy but it could not be shown by pooling analysis. J. Surg. Oncol. 2010; 101:486–494. © 2010 Wiley‐Liss, Inc.
Effect of vascular endothelial growth factor on nasal vascular permeability
Authors: Matsune Shoji , Ohori Junichiro , Yoshifuku Kousuke , Kurono Yuichi
Published: March 2010

Objectives/Hypothesis:

One of the major functions of vascular endothelial growth factor (VEGF) is increasing vascular permeability. We previously reported that VEGF is present in nasal secretions in rhinosinusitis, particularly in allergic rhinitis, and is hyperproduced immediately after antigen provocation. However, its function in nasal mucosa has not yet been investigated. This study was designed to estimate the increased vascular permeability by VEGF in nasal mucosa and to discuss its possible role in allergic rhinitis.

Study Design:

Prospective animal experiment.

Methods:

Hartley guinea pigs were used. Ethyl carbamate was injected into the abdomen for anesthesia, followed by intravenous injection of Evans blue into the femoral vein. Phosphate buffered saline, histamine, or VEGF was then applied to nasal cavities. Nasal mucosa was harvested after saline reflux from heart with phlebotomy by amputating the abdominal aorta. Tissue samples were soaked in formamide for 12 hours at 63°C to extract dye exudates from nasal mucosa. To analyze vascular permeability, dye was quantified by colorimetry.

Results:

VEGF increased vascular permeability in nasal mucosa, and was more than 1 × 106 times more potent than histamine on the basis of molar units. Although increased vascular permeability by VEGF was not inhibited by histamine 1 receptor antagonist, it was markedly inhibited by anti‐VEGF receptor antibodies.

Conclusions:

VEGF increased vascular permeability to a greater degree than histamine in nasal mucosa via a different pathway. Regulating VEGF may be a new therapeutic option for persistent nasal symptoms in allergic rhinitis. Laryngoscope, 2010
Functional outcomes of fibula and osteocutaneous forearm free flap reconstruction for segmental mandibular defects
Authors: Virgin Frank W. , Iseli Tim A. , Iseli Claire E. , Sunde Jumin , Carroll William R. , Magnuson Jeffery S. , Rosenthal Eben L.
Published: March 2010

Objective/Hypothesis:

To demonstrate that the osteocutaneous radial forearm free flap provides equivalent functional outcomes and improved morbidity compared to the fibular free flap in mandibular reconstruction.

Study Design:

Retrospective review.

Methods:

There were 168 patients requiring free flap reconstruction of segmental mandibular defects between January 2001 and December 2008. Mean follow‐up was 31 months for fibula free flap (FFF) (n = 117) and 20 months for osteocutaneous radial forearm free flaps (OCRFFF) (n = 51), reflecting an increasing use of forearms.

Results:

OCRFFF were more commonly used in older patients (mean 63.7 years vs. 59 years, P = .03). The majority (96.2%) of reconstruction was for malignant pathology. Flap failure was 3.4% for the fibula group and 3.9% in the forearm group. Malunion was infrequent (2.0% OCRFFF, 6.0% FFF, P = .26). Donor site complications were higher in the FFF group (4.3%) versus none in the OCRFF group (P = .13). Despite a high rate of long‐term survival in this patient population (75% at 5 years for carcinoma), dental implants were rarely placed (2.3% of patients) and were more common in forearm than fibula free flaps. Functional outcomes demonstrated no significant difference between groups with respect to oral diet (FFF 72.6% vs. OCRFFF 79.1%, P = .49) or retained enterogastric feeding tube (20.9% OCRFFF vs. 27.4% FFF, P = .49).

Conclusions:

Osteocutaneous radial forearm flaps provide comparable functional outcomes with less morbidity compared to fibula free flaps for selected segmental mandibulectomy defects. The overall dental implantation rate was low and more commonly performed in osteocutaneous radial forearm flaps compared to fibula flaps. Laryngoscope, 2010
Recovery of soil microbial community structure after fire in a sagebrush‐grassland ecosystem
Authors: Dangi S. R. , Stahl P. D. , Pendall E. , Cleary M. B. , Buyer J. S.
Published: March 2010

Recovery of the soil microbial community after fire in a sagebrush‐grassland ecosystem was examined using a chronosequence of four sites ranging in time since fire from 3–39 years. The successional stage communities examined included Recent Burn (3 years since fire, ysf), Establishment (7 ysf), Expansion (21 ysf), and Mature (39 ysf). Aboveground standing plant biomass increased with time since disturbance to the Mature stage where sagebrush became dominant over herbaceous species. Phospholipid fatty acid (PLFA) analysis was used to characterize the microbial community structure. Soil microbial community productivity generally appeared to be similar to the Mature site soil (39 ysf) within 7 years of fire. Diversity of PLFAs detected in soils, at both depths, increased from a low value of 29 at the Recent site to a high of 37 at the Establishment site and then decreased again to 31 at the Mature stage site. Canonical variates analysis indicated important disparities in microbial community structure at the four sites. Greatest disparities were observed in microbial community structure between the Recent and Establishment stages but greater similarity between the Recent stage and the sagebrush dominated Mature stage. This study emphasizes both short‐term and long‐term changes in the belowground community and suggests that soil microbial communities are highly resilient to disturbances after prescribed fire. Copyright © 2010 John Wiley & Sons, Ltd.
Synthesis and Structure/Property Relationships of Regioselective 2‐O‐, 3‐O‐ and 6‐O‐Ethyl Celluloses
Authors: Kamitakahara Hiroshi , Funakoshi Toshihiro , Nakai Shinji , Takano Toshiyuki , Nakatsubo Fumiaki
Published: March 2010

Regioselectively ethylated celluloses, 2‐O‐ (1), 3‐O‐ (2), and 6‐O‐ethyl‐ (3) celluloses were synthesized via ring‐opening polymerization of glucopyranose orthopivalate derivatives. The number‐average degrees of polymerization (DPns) of compounds 1 and 2 were calculated to be 10.6 and 49.4, respectively. Three kinds of compound 3 with different DPns were prepared: DPns = 12.9 (3‐1), 60.3 (3‐2), and 36.1 (3‐3). The 2‐O‐, 3‐O‐, and 6‐O‐ethylcelluloses were soluble in water, confirmed by NMR analysis. Furthermore, the 3‐O‐ (2), and 6‐O‐ethyl‐ (3‐2) celluloses showed thermo‐responsive aggregation behavior and had a lower critical solution temperature (LCST) at about 40 °C and 70 °C, respectively, based on the results from turbidity tests and DSC measurements. The 6‐O‐ethyl‐cellulose (3‐3) with DPn = 36.1 and DPw = 54.6 showed gelation behavior over approx 70 °C, whereas the 6‐O‐ethyl‐celluloses 3‐1 and 3‐2 with lower and higher molecular weight, such as DPns 12.9 and 60.3, did not show gelation behavior at this temperature. It was revealed that the position of ethyl group affected the phase transition temperature. According to our experiments, the 3‐O‐ethyl and 6‐O‐ethyl groups along the cellulose chains caused the thermo‐responsive property of their aqueous solutions. The appropriate DP of the regioselective 6‐O‐ethyl‐cellulose existed for gelation of the aqueous solution.

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Long‐term results of a multicenter study on subthalamic and pallidal stimulation in Parkinson's disease
Authors: Moro Elena , Lozano Andres M. , Pollak Pierre , Agid Yves , Rehncrona Stig , Volkmann Jens , Kulisevsky Jaime , Obeso Jose A. , Albanese Alberto , Hariz Marwan I. , Quinn Niall P. , Speelman Jans D. , Benabid Alim L. , Fraix Valerie , Mendes Alexandre , Welter Marie‐Laure , Houeto Jean‐Luc , Cornu Philippe , Dormont Didier , Tornqvist Annalena L. , Ekberg Ron , Schnitzler Alfons , Timmermann Lars , Wojtecki Lars , Gironell Andres , Rodriguez‐Oroz Maria C. , Guridi Jorge , Bentivoglio Anna R. , Contarino Maria F. , Romito Luigi , Scerrati Massimo , Janssens Marc , Lang Anthony E.
Published: March 2010

We report the 5 to 6 year follow‐up of a multicenter study of bilateral subthalamic nucleus (STN) and globus pallidus internus (GPi) deep brain stimulation (DBS) in advanced Parkinson's disease (PD) patients. Thirty‐five STN patients and 16 GPi patients were assessed at 5 to 6 years after DBS surgery. Primary outcome measure was the stimulation effect on the motor Unified Parkinson's Disease Rating Scale (UPDRS) assessed with a prospective cross‐over double‐blind assessment without medications (stimulation was randomly switched on or off). Secondary outcomes were motor UPDRS changes with unblinded assessments in off‐ and on‐medication states with and without stimulation, activities of daily living (ADL), anti‐PD medications, and dyskinesias. In double‐blind assessment, both STN and GPi DBS were significantly effective in improving the motor UPDRS scores (STN, P < 0.0001, 45.4%; GPi, P = 0.008, 20.0%) compared with off‐stimulation, regardless of the sequence of stimulation. In open assessment, both STN‐ and GPi‐DBS significantly improved the off‐medication motor UPDRS when compared with before surgery (STN, P < 0.001, 50.5%; GPi, P = 0.002, 35.6%). Dyskinesias and ADL were significantly improved in both groups. Anti‐PD medications were significantly reduced only in the STN group. Adverse events were more frequent in the STN group. These results confirm the long‐term efficacy of STN and GPi DBS in advanced PD. Although the surgical targets were not randomized, there was a trend to a better outcome of motor signs in the STN‐DBS patients and fewer adverse events in the GPi‐DBS group. © 2010 Movement Disorder Society
Objective measurement of dyskinesia in Parkinson's disease using a force plate
Authors: Chung Kathryn A. , Lobb Brenna M. , Nutt John G. , McNames James , Horak Fay
Published: March 2010

Clinical investigation of levodopa‐induced dyskinesia (LID) in Parkinson's disease (PD) is limited because of lack of objective measurements and no consensus on use of a standard measuring tool. Currently, clinical trials use subject‐completed diaries of dyskinesia throughout the day or investigator‐administered clinical rating scales. An objective and valid method of measuring LID would reduce bias, variability, and decrease the time and number needed in trials of potential anti‐dyskinetic agents. We have investigated using a force plate under standing subjects, which records movement of the center of pressure (CoP) to quantify LID over a levodopa (L‐dopa) cycle. Twenty‐two PD subjects (15 with LID, 7 without LID) admitted to an inpatient research facility had their PD meds withheld overnight, followed by a 2 hours intravenous L‐dopa infusion the next day. The root mean squared of the velocity in the anterior‐posterior direction (RMSV) derived from an analysis of the CoP, and, the modified Abnormal Involuntary Movement Scale (mAIMS) were performed repeatedly for 6 hours, initially as subjects were OFF before the infusion, through infusion until OFF again. There was a high correlation between the area under the curve (AUC) of the mAIMS and the RMSV within and between subjects. As a measure of LID, RMSV had excellent validity and reliability between subjects, and using a force plate was feasible. Sensitivity to changes in LID wasinitially demonstrated but should be repeated. Thus, CoP recordings on a force plate can objectively quantify LID in PD and may be very useful in clinical trials or other investigations of dyskinesia. © 2010 Movement Disorder Society
Technische Chemie 2009
Authors: Rößner Frank , Traa Yvonne , Oldiges Marco , Weber Hedda K.
Published: March 2010

Im Zuge des Rohstoffwandels und einer nachhaltigen Entwicklung erschließt die chemische Industrie neue Rohstoffquellen für Chemikalien und Treibstoffe. Biobasierte Verfahren haben einen festen Platz im Portfolio der Unternehmen und angesichts von immer mehr Produkten auf Basis nachwachsender Rohstoffe fragen Forscher, wie die Industrie ethisch vertretbar mit Rohstoffen zu versorgen ist und wie sich petrochemische und biobasierte Raffineriekonzepte verknüpfen lassen. Das Beispiel Holz zeigt, wie viel Chemie ein nachwachsender Rohstoff erfordert und ermöglicht.
In vivo diffusion tensor magnetic resonance imaging and fiber tracking of the mouse brain
Authors: Harsan Laura‐Adela , Paul Dominik , Schnell Susanne , Kreher Bjorn W. , Hennig Jürgen , Staiger Jochen F. , von Elverfeldt Dominik
Published: March 2010

Until very recently, the study of neural architecture using fixed tissue has been a major scientific focus of neurologists and neuroanatomists. A non‐invasive detailed insight into the brain's axonal connectivity in vivo has only become possible since the development of diffusion tensor magnetic resonance imaging (DT‐MRI). This unique approach of analyzing axonal projections in the living brain was used in the present study to describe major white matter fiber tracts of the mouse brain and also to identify for the first time non‐invasively the rich connectivity between the amygdala and different target regions. To overcome the difficulties associated with high spatially and temporally resolved DT‐MRI measurements a 4‐shot diffusion weighted spin echo (SE) echo planar imaging (EPI) protocol was adapted to mouse brain imaging at 9.4T. Diffusion tensor was calculated from data sets acquired by using 30 diffusion gradient directions while keeping the acquisition time at 91 min. Two fiber tracking algorithms were employed. A deterministic approach (fiber assignment by continuous tracking ‐ FACT algorithm) allowed us to identify and generate the 3D representations of various neural pathways. A probabilistic approach was further used for the generation of probability maps of connectivity with which it was possible to investigate – in a statistical sense ‐ all possible connecting pathways between selected seed points. We show here applications to determine the connection probability between regions belonging to the visual or limbic systems. This method does not require a priori knowledge about the projections' trajectories and is shown to be efficient even if the investigated pathway is long or three‐dimensionally complex. Additionally, high resolution images of rotational invariant parameters of the diffusion tensor, such as fractional anisotropy, volume ratio or main eigenvalues allowed quantitative comparisons in‐between regions of interest (ROIs) and showed significant differences between various white matter regions. Copyright © 2010 John Wiley & Sons, Ltd.
Two‐scale diffusion–deformation coupling model for material deterioration involving micro‐crack propagation
Authors: Terada Kenjiro , Kurumatani Mao
Published: March 2010

In this paper, we introduce a two‐scale diffusion–deformation coupled model that represents the aging material deterioration of two‐phase materials involving micro‐crack propagations. The mathematical homogenization method is applied to relate the micro‐ and macroscopic field variables, and a weak coupling solution method is employed to solve the two‐way coupling phenomena between the diffusion of scalar fields and the deformation of quasi‐brittle solids. The macroscopic mechanical behavior represented by the derived two‐scale two‐way coupled model reveals material nonlinearity due to micro‐scale cracking induced by the scalar‐field‐induced deformation, which can be simulated by the finite cover method. After verifying the fundamental validity of the proposed model and the analysis method, we perform a simple numerical example to demonstrate their ability to predict aging material deterioration. Copyright © 2010 John Wiley & Sons, Ltd.
Biodegradable ultrafine fibers with core–sheath structures for protein delivery and its optimization
Authors: Yang Ye , Li Xiaohong , He Shuhui , Cheng Long , Chen Fang , Zhou Shaobing , Weng Jie
Published: March 2010

This study was aimed to design core–sheath‐structured polymeric fibers for protein delivery through emulsion electrospinning to enhance the encapsulation efficiency (EE), structural integrity, and activity retention, and to achieve controllable protein release. Integral core–sheath structure was achieved for electrospun fibers with lysozyme loading efficiency of 93.3% and the specific activity retention (SAR) of 64.6%, while the surface protein content (SP) was as low as 4.2%. The emulsion components were optimized to minimize the burst release and extend the release period, and the release profiles were found to be closely related with the fiber characteristics such as the SPs. An initial burst release as low as 6.2% followed by gradual release for 33 days was indicated from poly(ethylene glycol)‐poly(DL‐lactide) (PELA) fibers. The gradual protein release was determined by a competition of fiber collapse leading to accelerated release and fiber fusion leading to decelerated release. Dependent on the matrix polymer and protein encapsulated, the degradation behaviors of the fiber matrices were correlated with the release rate and the effective lifetime of the drug release. The core–sheath‐structured ultrafine fibers could protect the structural integrity and bioactivity of encapsulated lysozyme, and an increase in the protective effect was demonstrated for fibers prepared from PELA matrix. Copyright © 2010 John Wiley & Sons, Ltd.
A prospective evaluation of the prevalence of symptomatic von Willebrand disease (VWD) in a pediatric primary care population
Authors: Bowman M. , Hopman W.M. , Rapson D. , Lillicrap D. , Silva M. , James P.
Published: March 2010

The prevalence of von Willebrand disease (VWD) is reported as ∼1%; however, these estimates were not based on individuals with significant symptoms. Four thousand five hundred ninety‐two unselected parents/children were asked: “Does your child have a problem with bleeding/bruising?”; 223 (5%) answered yes, 41 of whom were administered the validated Pediatric Bleeding Questionnaire and had VWF testing. Five were diagnosed with VWD (three type 1, one type 2A, one type 2B). The prevalence of bleeding/bruising in a general pediatric population is 5%; the prevalence of symptomatic VWD at the level of pediatric primary care is at least 1 in 1,000. Pediatr Blood Cancer 2010;55:171–173. © 2010 Wiley‐Liss, Inc.
Stopping the clock on proteomic degradation by heat treatment at the point of tissue excision
Authors: Goodwin Richard J. A. , Lang Alastair M. , Allingham Heather , Borén Mats , Pitt Andrew R.
Published: March 2010

The effectiveness of rapid and controlled heating of intact tissue to inactivate native enzymatic activity and prevent proteome degradation has been evaluated. Mouse brains were bisected immediately following excision, with one hemisphere being heat treated followed by snap freezing in liquid nitrogen while the other hemisphere was snap frozen immediately. Sections were cut by cryostatic microtome and analyzed by MALDI‐MS imaging and minimal label 2‐D DIGE, to monitor time‐dependent relative changes in intensities of protein and peptide signals. Analysis by MALDI‐MS imaging demonstrated that the relative intensities of markers varied across a time course (0–5 min) when the tissues were not stabilized by heat treatment. However, the same markers were seen to be stabilized when the tissues were heat treated before snap freezing. Intensity profiles for proteins indicative of both degradation and stabilization were generated when samples of treated and nontreated tissues were analyzed by 2‐D DIGE, with protein extracted before and after a 10‐min warming of samples. Thus, heat treatment of tissues at the time of excision is shown to prevent subsequent uncontrolled degradation of tissues at the proteomic level before any quantitative analysis, and to be compatible with downstream proteomic analysis.
Preparation, characterization, and binding profile of molecularly imprinted hydrogels for the peptide hepcidin
Authors: Abbate Vincenzo , Frascione Nunzianda , Bansal Sukhvinder S.
Published: March 2010

Molecularly imprinted hydrogels for the capture of the peptide hormone hepcidin were prepared by water‐in‐oil (w/o) suspension polymerization under mild conditions. Spherical and relatively uniformly sized gel beads were routinely obtained after optimization of the synthetic methodology. The polymers were analyzed by Fourier transform infrared spectroscopy, optical microscopy, and scanning electron microscopy. Although the imprinted materials exhibited higher affinity towards the epitope template (hepcidin N‐terminus) than their corresponding blank polymers, the full‐length target peptide was found strongly bound to all the hydrogels tested. However, by using whole fluorescent hepcidin as the print species, the imprinting effect was more pronounced. Moreover, bovine serum albumin did not bind to the poly N‐isopropylacrylamide (PNIPAm)‐based polymers. Thus, polymeric “sponges” for biomacromolecules with size‐exclusion effect were developed, useful for peptide concentration, immobilization and/or purification from serum samples. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 1721–1731, 2010
SET‐LRP of N,N‐dimethylacrylamide and of N‐isopropylacrylamide at 25 °C in protic and in dipolar aprotic solvents
Authors: Nguyen Nga H. , Rosen Brad M. , Percec Virgil
Published: March 2010

The single‐electron transfer living radical polymerization (SET‐LRP) of water‐soluble monomers, N,N‐dimethylacrylamide (DMA) and N‐isopropylacrylamide (NIPAM), initiated with 2‐methylchloropropionate (MCP) in dipolar aprotic and protic solvents is reported. The radical polymerization of acrylamides is characterized by higher rate constants of propagation and bimolecular termination than acrylates. Therefore, the addition of CuCl2 is required to mediate deactivation in the early stages of the reaction. Through the use of Cu(0)‐wire/Me6‐TREN catalysis, conditions were optimized to minimize the amount of externally added CuCl2 required to maintain a linear evolution of molecular weight and narrow molecular weight distribution. By using less CuCl2 additive, the amount of soluble copper species that must ultimately be removed from the reaction mixture is reduced. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 1752–1763, 2010
The process safety guerrilla: Giving your company a future, even if it does not want one
Authors: Berger Scott
Published: March 2010

You understand well that a strong process safety program not only prevents incidents but also improves overall operational discipline, quality, efficiency, and profitability. Unfortunately, your management thinks that process safety is some kind of hippie environmentalist thing that will shave a few dollars off quarter‐over‐quarter growth. If only you could implement the kind of transformative program demonstrated by the Center for Chemical Process Safety founding companies and other industry leaders, unfortunately, you're not at a sufficient level to champion such a transition, and the people at that level are not even in the ballpark, never mind willing to step up to the plate. Some day, maybe soon, the plant will go up in flames, and along with it will go your 401(k) and the livelihoods of your family, friends, and neighbors.

Now is the time for the downtrodden to rise up. How? By implementing the time‐honed guerrilla strategies used throughout the generations by those who lack the power of position. These strategies include theft, gangs, subterfuge, sabotage, arson, assassination, official corruption, and others.

Well… not really. But these “crimes” do suggest legal and effective ways of building a stronger process safety program from the bottom up. This article will summarize ways that clever and persistent “process safety guerillas” have precipitated positive change at their companies. © 2010 American Institute of Chemical Engineers Process Saf Prog 2010
Changes in the valence band structure of as‐grown InN(0001)‐2 × 2 surfaces upon exposure to oxygen and water
Authors: Eisenhardt Anja , Reiß Stephanie , Himmerlich Marcel , Schaefer Juergen A. , Krischok Stefan
Published: March 2010

We investigated the surface chemistry and valence band (VB) structure of as‐grown thin InN(0001)‐2 × 2 films as well as their change upon the exposure to oxygen and water. The InN films were grown by plasma‐assisted molecular beam epitaxy (PAMBE) and in situ characterized by reflection high electron energy diffraction (RHEED) and photoelectron spectroscopy (UPS, XPS). The oxygen and water exposure was directly performed on the as‐grown, contamination‐free InN surfaces at room temperature and leads to changes in the chemical surface states as well as the electronic properties. For 2 × 2 reconstructed InN surfaces one observes directly after growth a surface state at the Fermi‐edge which decreases continuously with oxygen and water exposure. Furthermore, two oxygen related electronic states develop in the VB at binding energies at around 5 and 10 eV. For water exposure a third weak state around 8 eV is additionally observed. The impact of oxygen and water on the work function Φ as well as the variation of surface band bending was investigated. In both cases for initially 2 × 2 reconstructed surfaces a reduction in the downward band bending is found, while Φ increases in the case of oxygen exposure but in the case of interaction with water a reduced work function is observed. The oxygen uptake rates reveal a higher reactivity of water with InN surfaces compared to oxygen. Furthermore, during oxidation and water exposure different chemical oxygen bonds are formed, but a direct assignment to In–O or N–O bonds is difficult due to changes in the In3d and N1s XPS core level peak shape.
Electron color center creation in LiF irradiated with Kr ions
Authors: Dauletbekova Alma , Akilbekov Abdirash , Zdorovets Maxim
Published: March 2010

First irradiation experiments on the cyclotron ion accelerator DC‐60 are presented. LiF crystals were irradiated with 147 MeV Kr+14 ions in the fluence (Φ) range 8 × 1010–3 × 1012 ions/cm2 at a beam current 20 nA/cm2 (corresponding to a flux ϕ ≈ 9 × 109 ions/cm2 s). The main electron microdefects (F‐type color centers) were studied by absorption spectroscopy in the spectral range 200–650 nm. After a linear increase with the fluence, single F centers saturate at Φ ≈ 1012 ions/cm2 and at higher fluences decrease, whereas the concentration of complex centers have a strong increase. The efficiency of F center creation at higher fluences decreases due to the strong recombination losses of primary Frenkel pairs.
Semiconductor nanolasers
Authors: Ning C. Z.
Published: March 2010

Semiconductor nanolasers represent the current frontier of research in the confluencing area of nanotechnology (or nanophotonics) and semiconductor lasers. In this paper, we review some of the most exciting progress made recently in the area. We will focus on nanoscale lasers made of semiconductor nanowires grown in a bottom‐up fashion or nanopillars that are produced through a top‐down wafer etching. Special features of these nanolasers will be reviewed. In particular, recent results on metal–semiconductor plasmonic lasers will be presented which represents the smallest lasers by taking advantages of surface plasmonic effects. Due to the small size and strong confinement in these nanolasers, certain familiar concepts in semiconductor‐laser physics need to be re‐examined to determine their validity or implication at nanoscale. These include the concept of modal gain and confinement factor (CF). The seemly abnormal behavior of CF in dielectric and plasmonic nanolasers will be explained from a unified point of view. Throughout this tutorial, we attempt to address the question of how small a laser can be made or whether there exists an ultimate size limit for a laser.

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Laser intensity profile along a nanowire laser. The nanowire laser is confined to the left by the substrate and surrounded by air from all other sides.
Geometric rearrangement of adsorbate driven by the charge transfer
Authors: Pavlyukh Yaroslav , Berakdar Jamal , Hübner Wolfgang
Published: March 2010

Adsorption of alkali atoms induces a significant charge redistribution in the region around the adatom. Such charge displacement is associated with a large dipole moment responsible for the interaction of adatoms and a reduction of the surface work function. In addition to these well‐known effects our first principles simulations for the ${\rm Na}_9^ +$ cluster on the Cu(001) surface demonstrate how the charge transfer (CT) from the adsorbate to the substrate can drastically change the geometric structure of the cluster. We report on a detailed study of the adsorption process using quantum chemistry. A representation of the substrate by a cluster of 54 Cu atoms allows us to treat quantum mechanically the electronic structure of both systems, the adsorbate and the surface, on equal footing. Subsequently, we analyze the charge distribution in the composite system. Convergence of the results is verified by considering a much larger substrate cluster containing 126 Cu atoms. The role of the CT is further elucidated by the geometry optimization of the bare cluster with and without an electron deficit. It is shown that the CT drives the system to a meta‐stable state which thereafter relaxes to a new configuration.
Wound healing and protease inhibition activity of Bacoside‐A, isolated from Bacopa monnieri wettest
Authors: Sharath R. , Harish B.G. , Krishna V. , Sathyanarayana B.N. , Swamy H.M. Kumara
Published: March 2010

Bacopa monnieri (L.) Wettest. (Scrophulariaceae) is a well‐known medicinal herb. In the Indian system of medicine it is known as Brahmi (Sanskrit) and Indian water hyssop. Methanolic extract of Bacopa monnieri and its isolated constituent Bacoside‐A were screened for wound healing activity. Bacoside‐A was screened for wound healing activity by excision, incision and dead space wound on Swiss albino rats. Significant wound healing activity was observed in both extract and the Bacoside‐A treated groups. The SDS‐PAGE caseinolytic zymogram analysis of inhibition of matrix metalloproteases (MMPs) enzyme from the excision wound by Bacoside‐A, an isolated constituent, was done with the concentrations 100 and 200 μmg/ml. In Bacoside‐A treated groups, epithelialization of the excision wound was faster with a high rate (18.30 ± 0.01 days) of wound contraction. The tensile strength of the incision wound was increased (538.47 ± 0.14 g) in the Bacoside‐A treated group. In the dead space wound model, the weight of the granuloma was also increased (89.15 ± 0.08 g). The histological examination of the granuloma tissue of the Bacoside‐A treated group showed increased cross‐linking of collagen fibers and absence of monocytes. The wound healing activity of Bacoside‐A was more effective in various wound models compared to the standard skin ointment Nitrofurazone. Copyright © 2010 John Wiley & Sons, Ltd.
Exploring the interactions between gold nanoparticles and analytes through surface‐assisted laser desorption/ionization mass spectrometry
Authors: Lin Yang‐Wei , Chen Wen‐Tsen , Chang Huan‐Tsung
Published: March 2010

Surface‐assisted laser desorption/ionization mass spectrometry (SALDI‐MS) is applied to provide strong evidence for the chemical reactions of functionalized gold nanoparticles (Au NPs) with analytes – Hg2+ ions induced MPA−Au NPs aggregation in the presence of 2,6‐pyridinedicarboxylic acid (PDCA) and H2O2 induced fluorescence quenching of 11‐MUA−Au NDs. PDCA‐Hg2+‐MPA coordination is responsible for Au NPs aggregation, while the formation of 11‐MUA disulfide compounds that release into the bulk solution is responsible for H2O2‐induced fluorescence quenching. In addition to providing information about the chemical structures, SALDI‐MS is also selective and sensitive for the detection of Hg2+ ions and H2O2. The limits of detection (LODs) for Hg2+ ions and H2O2 by SALDI‐MS were 300 nM and 250 µM, respectively. The spot‐to‐spot variations in the two studies were both less than 18% (50 sample spots). Our results reveal that SALDI‐MS can be used to study analyte‐induced changes in the surface properties of nanoparticles. Copyright © 2010 John Wiley & Sons, Ltd.
A clean‐up technology for the simultaneous determination of lysophosphatidic acid and sphingosine‐1‐phosphate by matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry using a phosphate‐capture molecule, Phos‐tag
Authors: Morishige Jun‐ichi , Urikura Mai , Takagi Haruko , Hirano Kaoru , Koike Tohru , Tanaka Tamotsu , Satouchi Kiyoshi
Published: March 2010

Lysophosphatidic acid (LPA) and sphingosine‐1‐phosphate (S1P) are growth factor‐like lipids having a phosphate group. The concentrations of these mediator lipids in blood are considered to be potential biomarkers for early detection of cancer or vascular diseases. Here, we report a method for simultaneous determination of LPA and S1P using Phos‐tag, a zinc complex that specifically binds to a phosphate‐monoester group. Although both LPA and S1P are hydrophilic compounds, we found that they acquire hydrophobic properties when they form complexes with Phos‐tag. Based on this finding, we developed a method for the enrichment of LPA and S1P from biological samples. The first partition in a two‐phase solvent system consisting of chloroform/methanol/water (1:1:0.9, v/v/v) is conducted for the removal of lipids. LPA and S1P are specifically extracted as Phos‐tag complexes at the second partition by adding Phos‐tag. The Phos‐tag complexes of LPA and S1P are detectable by matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry (MALDI‐TOFMS) and quantifiable based on the relative intensities of ions using 17:0 LPA and C17 S1P as internal standards. The protocol was validated by analyses of these mediator lipids in calf serum, a rat brain and a lung. The clean‐up protocol is rapid, requires neither thin‐layer chromatography (TLC) nor liquid chromatography (LC), and is applicable to both blood and solid tissue samples. We believe that our protocol will be useful for a routine analysis of LPA and S1P in many clinical samples. Copyright © 2010 John Wiley & Sons, Ltd.
Hydrogen/deuterium exchange on aromatic rings during atmospheric pressure chemical ionization mass spectrometry
Authors: Davies Noel W. , Smith Jason A. , Molesworth Peter P. , Ross John J.
Published: March 2010

It has been demonstrated that substituted indoles fully labelled with deuterium on the aromatic ring can undergo substantial exchange back to partial and even fully protonated forms during atmospheric pressure chemical ionisation (APCI) liquid chromatography/mass spectrometry (LC/MS). The degree of this exchange was strongly dependent on the absolute quantity of analyte, the APCI desolvation temperature, the nature of the mobile phase, the mobile phase flow rate and the instrument used. Hydrogen/deuterium (H/D) exchange on several other aromatic ring systems during APCI LC/MS was either undetectable (nitrobenzene, aniline) or extremely small (acetanilide) compared to the effect observed for substituted indoles. This observation has major implications for quantitative assays using deuterium‐labelled internal standards and for the detection of deuterium‐labelled products from isotopically labelled feeding experiments where there is a risk of back exchange to the protonated form during the analysis. Copyright © 2010 John Wiley & Sons, Ltd.
The production of entrepreneurial opportunity: a constructivist perspective
Authors: Wood Matthew S. , McKinley William
Published: March 2010

This article presents a conceptual model of entrepreneurial opportunity production from a constructivist perspective. The model assumes that opportunity production proceeds through several stages, including conceptualization of an opportunity idea by an entrepreneur, objectification of that idea, and enactment of the opportunity into a new venture. However, not all opportunity ideas survive this full process. Between the conceptualization stage and the objectification stage, some ideas are abandoned due to inadequate objectification. Also, between the objectification stage and the enactment stage, some objectified opportunities are abandoned due to insufficient resource support. We identify variables that influence the likelihood that opportunity ideas will be objectified and other variables that influence the likelihood that objectified opportunities will be enacted, and these variables are incorporated into empirically testable propositions. In the discussion section, we describe several boundary conditions for our theory, contrast the theory with objectivist (discovery) theory, and derive implications for future research. Copyright © 2010 Strategic Management Society.
Estimating the crude probability of death due to cancer and other causes using relative survival models
Authors: Lambert P. C. , Dickman P. W. , Nelson C. P. , Royston P.
Published: March 2010

Relative survival is used extensively in population‐based cancer studies to measure patient survival correcting for causes of death not related to the disease of interest. An advantage of relative survival is that it provides a measure of mortality associated with a particular disease, without the need for information on cause of death. Relative survival provides a measure of net mortality, i.e. the probability of death due to cancer in the absence of other causes. This is a useful measure, but it is also of interest to measure crude mortality, i.e. the probability of death due to cancer in the presence of other causes. A previous approach to estimate the crude probability of death in population‐based cancer studies used life table methods, but we show how the estimates can be obtained after fitting a relative survival model. We adopt flexible parametric models for relative survival, which use restricted cubic splines for the baseline cumulative excess hazard and for any time‐dependent effects. We illustrate the approach using an example of men diagnosed with prostate cancer in England and Wales showing the differences in net and crude survival for different ages. Copyright © 2010 John Wiley & Sons, Ltd.
Checking consistency in mixed treatment comparison meta‐analysis
Authors: Dias S. , Welton N. J. , Caldwell D. M. , Ades A. E.
Published: March 2010

Pooling of direct and indirect evidence from randomized trials, known as mixed treatment comparisons (MTC), is becoming increasingly common in the clinical literature. MTC allows coherent judgements on which of the several treatments is the most effective and produces estimates of the relative effects of each treatment compared with every other treatment in a network.

We introduce two methods for checking consistency of direct and indirect evidence. The first method (back‐calculation) infers the contribution of indirect evidence from the direct evidence and the output of an MTC analysis and is useful when the only available data consist of pooled summaries of the pairwise contrasts. The second more general, but computationally intensive, method is based on ‘node‐splitting’ which separates evidence on a particular comparison (node) into ‘direct’ and ‘indirect’ and can be applied to networks where trial‐level data are available. Methods are illustrated with examples from the literature. We take a hierarchical Bayesian approach to MTC implemented using WinBUGS and R.

We show that both methods are useful in identifying potential inconsistencies in different types of network and that they illustrate how the direct and indirect evidence combine to produce the posterior MTC estimates of relative treatment effects. This allows users to understand how MTC synthesis is pooling the data, and what is ‘driving’ the final estimates.

We end with some considerations on the modelling assumptions being made, the problems with the extension of the back‐calculation method to trial‐level data and discuss our methods in the context of the existing literature. Copyright © 2010 John Wiley & Sons, Ltd.