bluuebunny/crossref_metadata_2025 huggingface dataset:
Measurements of chlorophyll fluorescence as an auxiliary method in estimating susceptibility of cultivated hazel (Corylus L.) for filbert aphid (Myzocallis coryli goetze)
Authors: Gantner Magdalena , Michałek Władysław
Published: April 2013

The influence of aphid feeding on chlorophyll a fluorescence in the leaves of four cultivated hazel cultivars, with different levels of resistance to filbert aphid (Myzocallis coryli Goetze), was studied. The maximum effect of photosystem reaction measured on dark-adapted hazel leaves (Fv/Fm parameter) and maximum efficiency of photon energy PAR conversion to chemical energy in light conditions (Y parameter) were estimated twice, in the leaves of four hazel cultivars with different levels of resistance to filbert aphid, using a fluorometer PAM- 2000 by Walz GmbH - Germany. The analysis of changes of these parameters showed that aphid feeding caused a reaction in all tested cultivars. The most visible reduction of the Fv/Fm and Y values as a result of aphid feeding was observed in the cultivars 'Cud z Bollwiller' and 'Olbrzymi z Halle', numerously colonized by aphids. A smaller number of aphids found on the leaves of more resistant cultivars - 'Kataloński' and 'Lamberta Biały', caused a weaker response of plants and a smaller decline in the value of this parameter. 'Cud z Bollwiller' cultivar showed higher tolerance than other tested cultivars to stress caused by the feeding of sucking insects. The Fv/Fm and Y parameters can be regarded as reliable indexes useful in diagnosing susceptibility of hazel cultivars to aphids, helpful in determining, for example, harmfulness thresholds.
Influence of crop rotation and meteorological conditons on density and biomass of weeds in spring barley (Hordeum vulgare L.)
Authors: Wanic Maria , Jastrzębska Magdalena , Kostrzewska Marta K.
Published: April 2013

The paper presents the analysis of changes in weed infestation in spring barley cultivated in the years 1990-2004 in crop rotation with a 25% proportion of this cereal (potato - spring barley - sowing peas - winter triticale), when it was grown after potato, and in crop rotation with its 75% proportion (potato - spring barley - spring barley - spring barley), when it was grown once or twice after spring barley. In the experiment, no weed control was applied. Every year in the spring (at full emergence of the cereal) and before the harvest, the composition of weed species and weed density of particular weed species were determined, and before the harvest also their biomass. Weed density increased linearly on all plots during the 15-year period. The average values confirm the increase in weed biomass in the case when spring barley was grown once or twice after this crop; however, those differences were influenced by the previous situation only during some seasons. Weed density and biomass showed high year-to-year variability and a positive correlation with the amount of precipitation and a negative correlation with temperature during the period of the study. A negative correlation between the yield of barley and weed biomass was shown.
The effect of the application of the biological control agent EM1 on gas exchange parameters and productivity of Pisum sativum L. infected with Fusarium oxysporum Schlecht.
Authors: Okorski Adam , Olszewski Jacek , Głowacka Katarzyna , Okorska Sylwia , Pszczółkowska Agnieszka
Published: April 2013

A pot experiment on different methods of EM 1 application was conducted in the period 2002-2004. The study was carried out under controlled growth conditions. The experimental factor was the method of EM1 application. Before application, the biological preparation EM1 was propagated as recommended by the manufacturer (Greenland). The health status of the aboveground parts of 'Ramrod' pea plants was estimated at the flowering stage. The assessment of pea leaf gas exchange parameters (An, E, Gs, and Ci) was made using a LI-Cor 6400 Portable Photosynthesis System. Soil application of EM1 combined with chemical control contributed to inhibiting Fusarium wilt of pea. Foliar application of EM1 combined with chemical control increased all gas exchange rates of pea leaves. Fusarium wilt of pea insignificantly decreased all gas exchange rates of pea leaves and the number of seeds per pod. The best method of EM1 application was soil treatment combined with chemical control, which increased all yield-related morphometric parameters of pea.
The effect of the method of application and concentration of asahi sl on the response of cucumber plants to chilling stress
Authors: Borowski Edward
Published: April 2013

In pot experiments conducted on cucumber cv. Śremski F1, the effect was studied of short-term chilling stress on plants which had grown from seeds germinating in the solution of Asahi SL or treated with this biostimulator during the early growth period. The plants were grown in a phytotron at an air temperature of 27/22°C (day/night), using fluorescent light with FAR flux density of 220 μmol x m-2 x s-1 and with a photoperiod of 16/8. The biostimulator was applied using the following methods: a) germination of seeds in 0.01% and 0.05% solution, b) watering of plants twice with 0.01% or 0.05% solution, c) spraying leaves with 0.3% or 0.5% solution. Plants sprayed with distilled water were the control. After 24 hours from foliar or root application of Asahi SL, one half of the plants from each experimental series was treated for a period of 3 days at a temperature of 12/6°C, with all the other growth conditions unchanged. The obtained results show that short-term chilling stress caused a significant increase in electrolyte leakage, free proline content and in the activity of ascorbate peroxidase in leaves, but a decrease in the content of chlorophyll, its maximum fluorescence (Fm) and quantum yield (Fv/Fm), carotenoid content, stomatal conductance, transpiration, photosynthesis, leaf biomass and in the activity of catalase in leaves. Foliar or root application of Asahi SL in the pre-stress period decreased the values of the traits which increased as a result of chilling or increased those which decreased. Higher concentrations of the biostimulator solutions, applied using this method, were more effective. The application of the biostimulator during seed germination did not result in significant changes in the response of plants to chilling stress.
Unilateral Orbital Compartment Syndrome with Cavernous Sinus Thrombosis after Prolonged Prone Position Anaesthesia for Spinal Surgery
Authors: Khan Mansur Ali , Agarwal Sanjeev , Shankar Sandeep
Published: April 2013

Orbital compartment syndrome is a rare but preventable cause of blindness. A 42 year male patient, a case of accidental fracture cervical spine and quadriplegia underwent cervical spine surgery under general anaesthesia. Surgery was performed with patient in prone position on a padded horse shoe stand for 4 hours duration. Proptosis, redness and chemosis of right eye was noticed 3 hours after recovery from general anaesthesia. The affected eye was stony hard with corneal oedema, fixed dilated pupil, total ophthalmoplegia and absent perception of light. Other eye was unaffected. An urgent canthotomy and cantholysis was done and topical as well as systemic antiglaucoma treatment instituted along with systemic and topical antibiotics. A contrast-enhanced computed tomography, done the next day revealed anterior displacement with posterior tenting of right globe and bilateral cavernous sinus thrombosis. Proptosis and swelling subsided gradually without any recovery of vision. Generalised retinal atrophy and secondary optic atrophy was seen 3 weeks post surgery.
Spontaneous Resolution of Traumatic Macular Hole in a Child
Authors: Verma Lalit , Chakravarti Arindam , Gupta Avnindra , Prakash Smriti
Published: April 2013

There are several published reports on spontaneous closure of idiopathic macular hole but information regarding spontaneous closure of traumatic macular hole is limited. We present a case of spontaneous resolution of post traumatic macular hole in a 9 year old child with associated visual recovery. The child was followed up for seven months and the morphological changes were documented on optical coherence tomography. The case study illustrates the role of conservative management of traumatic macular hole in selected young patients, thus preventing the need for surgical intervention and its possible difficulties and complications.
Interferons in Ophthalmology Current Status and Advancing Trends
Authors: Gantyala Shiva Prasad , Shekhar Himanshu , Vanathi M. , Sinha Rajesh , Titiyal Jeewan Singh
Published: April 2013

Interferon, a natural multifunctional protein, has been an important part of medical therapy in various ophthalmic indications. Interferons are classified as alpha, beta and gamma interferons based on molecular structure and grouped into types 1 and 2 depending on their cellular effects. Its various actions include antiviral, antiproliferative, immunomodulatory and antiangiogenic effects. Its verstile actions makes it valid indication in treating various intraocular and extraocular diseases. Its local use is indicated in ocular surface neoplasia, viral keratitis, mooren’s ulcer, VKC and systemic use in Behcet’s disease, cystoid macualr edema, AMD and optic neuritis with multiple sclerosis.
Mg‐PSZ Reinforced TRIP‐Steel MMCs – In Situ CT Investigations of Cruciform Samples under Compressive Loading
Authors: Ballaschk Uta , Berek Harry , Ehinger David , Aneziris Christos G. , Krüger Lutz
Published: April 2013

Mechanical in situ CT investigations on cruciform members of square‐celled Mg‐PSZ reinforced TRIP‐steel honeycomb structures are presented. Furthermore, test series on a pure TRIP‐steel and MMC bulk material with 10 vol% Mg‐PSZ as well as macro‐scale compression tests on honeycomb structures are performed under quasi‐static loading. The measured stress–strain curves of the cruciform columns are related to their buckling and failure behaviour. The mechanical and structural characteristics of the cell wall node elements are compared to the damage mechanisms of the complete honeycombs. Differences in the damage patterns between the pure TRIP‐steel and the MMC are demonstrated. The phase transformation effect in the Mg‐PSZ particles is pointed out based on EBSD and EDX measurements.
BiSbTe‐Based Nanocomposites with High ZT: The Effect of SiC Nanodispersion on Thermoelectric Properties
Authors: Li Jianhui , Tan Qing , Li Jing‐Feng , Liu Da‐Wei , Li Fu , Li Zong‐Yue , Zou Minmin , Wang Ke
Published: April 2013

Thermoelectric materials have potential applications in energy harvesting and electronic cooling devices, and bismuth antimony telluride (BiSbTe) alloys are the state‐of‐the‐art thermoelectric materials that have been widely used for several decades. It is demonstrated that mixing SiC nanoparticles into the BiSbTe matrix effectively enhances its thermoelectric properties; a high dimensionless figure of merit (ZT) value of up to 1.33 at 373 K is obtained in Bi0.3Sb1.7Te3 incorporated with only 0.4 vol% SiC nanoparticles. SiC nanoinclusions possessing coherent interfaces with the Bi0.3Sb1.7Te3 matrix can increase the Seebeck coefficient while increasing the electrical conductivity, in addition to its effect of reducing lattice thermal conductivity by enhancing phonon scattering. Nano‐SiC dispersion further endows the BiSbTe alloys with better mechanical properties, which are favorable for practical applications and device fabrication.
Inventory pinch algorithm for gasoline blend planning
Authors: Castillo Pedro A. Castillo , Mahalec Vladimir , Kelly Jeffrey D.
Published: April 2013

Current gasoline blend scheduling practice is to optimize blend plans via fixed duration (e.g., days) multiperiod NLP or MINLP models and schedule blends via interactive simulation. Solutions of multiperiod models typically have different blend recipes for each time period. We introduce inventory pinch points and use them to construct an algorithm based on single‐period nonlinear model to minimize the number of different blend recipes. The algorithm optimizes multigrade blend recipes for each period delimited by the inventory pinch points and then uses a fine‐grid multiperiod fixed‐recipe MILP to compute blend volumes profile. If MILP is infeasible, a corresponding period between the pinch points is subdivided and recipes are reoptimized. In our case studies, solutions are computed in significant less time and are most often within 0.01% of the solutions by multiperiod MINLP. Reduced number of blend recipes makes it easier for the blend scheduler to create a schedule by interactive simulation. © 2013 American Institute of Chemical Engineers AIChE J, 59: 3748–3766, 2013
Recent Developments in Amine‐catalyzed Non‐asymmetric Transformations
Authors: Ren Qiao , Wang Jian
Published: April 2013

Amine catalysis has emerged as a powerful and elegant method to construct diverse chiral scaffolds in asymmetric synthesis. However, amine‐based non‐asymmetric organocatalysis is still in its infancy. This Focus Review examines recent developments in amine‐catalyzed non‐asymmetric transformations based on enamine, iminium, di‐ or trienamine, and oxidative enamine catalysis.
The Photocatalyzed Meerwein Arylation: Classic Reaction of Aryl Diazonium Salts in a New Light
Authors: Hari Durga Prasad , König Burkhard
Published: April 2013

The use of diazonium salts for aryl radical generation and CH arylation processes has been known since 1896 when Pschorr first used the reaction for intramolecular cyclizations. Meerwein developed it further in the early 1900s into a general arylation method. However, this reaction could not compete with the transition‐metal‐mediated formation of C(sp2)C(sp2) bonds. The replacement of the copper catalyst with iron and titanium compounds improved the situation, but the use of photocatalysis to induce the one‐electron reduction and activation of the diazonium salts is even more advantageous. The first photocatalyzed Pschorr cyclization was published in 1984, and just last year a series of papers described applications of photocatalytic Meerwein arylations leading to aryl–alkene coupling products. In this Minireview we summarize the origins of this reaction and its scope and applications.
Fractional‐Order Dynamic Output Feedback Sliding Mode Control Design for Robust Stabilization of Uncertain Fractional‐Order Nonlinear Systems
Authors: Dadras Sara , Momeni Hamid Reza
Published: April 2013

A robust fractional‐order dynamic output feedback sliding mode control (DOF‐SMC) technique is introduced in this paper for uncertain fractional‐order nonlinear systems. The control law consists of two parts: a linear part and a nonlinear part. The former is generated by the fractional‐order dynamics of the controller and the latter is related to the switching control component. The proposed DOF‐SMC ensures the asymptotical stability of the fractional‐order closed‐loop system whilst it is guaranteed that the system states hit the switching manifold in finite time. Finally, numerical simulation results are presented to illustrate the effectiveness of the proposed method.
Autistic Traits and Sensitivity to Interference With Flavour Identification
Authors: Clark Andrea Irene , Hughes Paul Shane , Grube Manon , Stewart Mary Elizabeth
Published: April 2013

We assessed whether autistic traits are related to the ability to identify flavour. In general, the colour of the food or drink facilitates identification of its flavour. In the current study, the colour of drinks either provided congruent, incongruent or ambiguous (colourless) information about the flavour. Participants identified the flavours of 12 drinks from a list and completed a measure of autistic traits, the Autism‐Spectrum Quotient (AQ). In line with previous studies, flavour identification was impaired in incongruent conditions, while identification in congruent conditions was not improved when compared with that in ambiguous conditions. AQ scores were related to flavour identification in incongruent conditions, in that as the AQ score increased, accuracy of flavour identification decreased. There were no relationships found in the congruent or ambiguous conditions. This finding is in line with the idea that conflicting sensory information may be more disruptive for individuals on the autism spectrum. Autism Res 2013, ●●: ●●–●●. © 2013 International Society for Autism Research, Wiley Periodicals, Inc.
A situative metaphor for teacher learning: the case of university tutors learning to grade student coursework
Authors: Boyd Pete , Bloxham Sue
Published: April 2013

In the continuing concern about academic standards in the higher education sector a great deal of emphasis has been placed on quality assurance procedures rather than on considering how university tutors learn to grade the quality of work produced by students. As part of a larger research project focused on how tutors grade student coursework, this paper offers a new metaphor for such tutor learning, based on a sociocultural perspective. The research project used think‐aloud protocols recorded as university tutors graded student coursework, and this was followed by semi‐structured interviews. The voluntary participants consisted of 25 lecturers in four contrasting domains—humanities, art and design, medicine and teacher education—in three universities, two teaching‐led and one research intensive. We developed a metaphorical framework that helps to understand the work and learning of the lecturers and tested it by applying it to analysis of the tutor interview data. Grading, writing feedback, second marking and moderation are important situated professional learning opportunities for tutors to debate and reach agreement on the academic standard demonstrated by student coursework. The metaphor considers professional learning as interplay between the vertical domain of public knowledge and the horizontal domain of teachers' practical wisdom. The metaphor presented in this paper is proposed for critical consideration and wider use by academics, teachers, academic developers and teacher educators as an aid to better understanding of teacher's professional learning.
Ständig Neues aus dem Stock
Authors: Tautz Jürgen , Vonend Kristina
Published: April 2013

Über das Internet‐Projekt HOBOS können Schülerinnen und Schüler das drittwichtigste Nutztier des Menschen nach Rind und Schwein online kennenlernen. Sie können sehen und messen, was gerade live im Stock und außerhalb vor sich geht und eigenständig auf einfache, aber auch auf hochkomplexe Prozesse rund um den Bienenstaat schließen.
Tirucallane Triterpenoids from the Stems of Brucea mollis
Authors: Chen Hui , Ma Shuang‐Gang , Fang Zhen‐Feng , Bai Jian , Yu Shi‐Shan , Chen Xiao‐Guang , Hou Qi , Yuan Shao‐Peng , Chen Xia
Published: April 2013

Three new tirucallane triterpenoids, brumollisols A–C (1–3, resp.), together with five known analogues, (23R,24S)‐23,24,25‐trihydroxytirucall‐7‐ene‐3,6‐dione (4), piscidinol A (5), 24‐epipiscidinol A (6), 21α‐methylmelianodiol (7), and 21β‐methylmelianodiol (8), were isolated from an EtOH extract of the stems of Brucea mollis. Their structures were elucidated by means of spectroscopic methods including 1D‐ and 2D‐NMR techniques and mass spectrometry. In the in vitro assays, compound 6 exhibited significant cytotoxic activity against A549 and BGC‐823 cancer cells with IC50 values of 1.16 and 3.01 μM, respectively. At a concentration of 10 μM, compounds 1–5, 7, and 8 were found to inhibit NO production in mouse peritoneal macrophages with inhibitory ratios ranging from 39.8±7.7 to 68.2±4.5%.
Triterpene Glucosides from the Leaves of Aralia elata and Their Cytotoxic Activities
Authors: Kuang Hai‐Xue , Wang Zhi‐Bin , Wang Qiu‐Hong , Yang Bing‐You , Xiao Hong‐Bin , Okada Yoshihito , Okuyama Tohru
Published: April 2013

Three new triterpene glucosides, named congmuyenosides C–E (1–3, resp.), along with four known ones, were isolated from an EtOH extract of Aralia elata (Miq.) Seem. leaves. The structures of the new compounds were identified as 3‐O‐{β‐D‐glucopyranosyl‐(1→3)‐β‐D‐glucopyranosyl‐(1→3)‐[β‐D‐glucopyranosyl‐(1→2)]‐β‐D‐glucopyranosyl}caulophyllogenin (1), 3‐O‐{β‐D‐glucopyranosyl‐(1→3)‐β‐D‐glucopyranosyl‐(1→3)‐[β‐D‐glucopyranosyl‐(1→2)]‐β‐D‐glucopyranosyl}hederagenin 28‐O‐β‐D‐glucopyranosyl ester (2), 3‐O‐{β‐D‐glucopyranosyl‐(1→3)‐β‐D‐glucopyranosyl‐(1→3)‐[β‐D‐glucopyranosyl‐(1→2)]‐β‐D‐glucopyranosyl}echinocystic acid 28‐O‐β‐D‐glucopyranosyl ester (3) on the basis of spectral analyses, including MS, 1H‐NMR, 13C‐NMR, DEPT, HSQC, HMBC, NOESY, and HSQC‐TOCSY experiments. All isolates obtained were evaluated for their cytotoxic activities against three human tumor cell lines (HepG2, SKOV3, and A549). Compound 3 showed significant cytotoxicity against A549 cell line (IC50 9.9±1.5 μM).
Antitumor Effect of the Essential Oil from Leaves of Guatteria pogonopus (Annonaceae)
Authors: do N. Fontes José Eraldo , Ferraz Rosana P. C. , Britto Anny C. S. , Carvalho Adriana A. , Moraes Manoel O. , Pessoa Claudia , Costa Emmanoel V. , Bezerra Daniel P.
Published: April 2013

Guatteria pogonopus Martius, a plant belonging to the Annonaceae family, is found in the remaining Brazilian Atlantic Forest. In this study, the chemical composition and antitumor effects of the essential oil isolated from leaves of G. pogonopus was investigated. The chemical composition of the oil was determined by GC‐FID and GC/MS analyses. The in vitro cytotoxicity was evaluated against three different tumor cell lines (OVCAR‐8, NCI‐H358M, and PC‐3M), and the in vivo antitumor activity was tested in mice bearing sarcoma 180 tumor. A total of 29 compounds was identified and quantified in the oil. The major compounds were γ‐patchoulene (13.55%), (E)‐caryophyllene (11.36%), β‐pinene (10.37%), germacrene D (6.72%), bicyclogermacrene (5.97%), α‐pinene (5.33%), and germacrene B (4.69%). The essential oil, but neither (E)‐caryophyllene nor β‐pinene, displayed in vitro cytotoxicity against all three tumor cell lines tested. The obtained average IC50 values ranged from 3.8 to 20.8 μg/ml. The lowest and highest values were obtained against the NCI‐H358M and the OVCAR‐8 cell lines, respectively. The in vivo tumor‐growth‐inhibition rates in the tumor‐bearing mice treated with essential oil (50 and 100 mg/kg/d) were 25.3 and 42.6%, respectively. Hence, the essential oil showed significant in vitro and in vivo antitumor activity.
Chemotaxonomic Implications of the n‐Alkane Composition and the Nonacosan‐10‐ol Content in Picea omorika, Pinus heldreichii, and Pinus peuce
Authors: Nikolić Biljana , Tešević Vele , Bojović Srdjan , Marin Petar D.
Published: April 2013

The n‐alkane composition and the nonacosan‐10‐ol content in the needle cuticular waxes of Serbian spruce (Picea omorika), Bosnian pine (Pinus heldreichii), and Macedonian pine (Pinus peuce) were compared. The amount of nonacosan‐10‐ol in the needle waxes of P. omorika was higher than those in P. heldreichii and P. peuce. The range of n‐alkanes was also wider in P. omorika (C18–C35) than in P. heldreichii and P. peuce (C18–C33). The dominant n‐alkanes were C29 in the needle waxes of P. omorika, C23, C27, and C25 in those of P. heldreichii, and C29, C25, C27, and C23 in those of P. peuce. The waxes of P. omorika contained higher amounts of n‐alkanes C29, C31, and C33, while those of P. heldreichii and P. peuce had higher contents of n‐alkanes C21, C22, C23, C24, and C26. The principal component analysis of the contents of nine n‐alkanes showed a clear separation of the Serbian spruce populations from those of the two investigated pine species, which partially overlapped. The separation of the species was due to high contents of the n‐alkanes C29 and C31 (P. omorika), C19, C20, C21, C22, C23, and C24 (P. heldreichii), and C28 (P. peuce). Cluster analysis also showed a clear separation between the P. omorika populations on one side and the P. heldreichii and P. peuce populations on the other side. The n‐alkane and terpene compositions are discussed in the light of their usefulness in chemotaxonomy as well as with regard to the biogeography and phylogeny of these rare and endemic conifers.
Synthesis and Evaluation of Biphenyl Compounds as Kinesin Spindle Protein Inhibitors
Authors: Holland Jason P. , Kang Albert , Cohrs Susan , Selivanova Svetlana V. , Milicevic Sephton Selena , Betzel Thomas , Frey Daniel , Wieser Mara , Jaussi Rolf , Kammerer Richard A. , Schibli Roger , Fischer Eliane
Published: April 2013

Kinesin spindle protein (KSP), an ATP‐dependent motor protein, plays an essential role in bipolar spindle formation during the mitotic phase (M phase) of the normal cell cycle. KSP has emerged as a novel target for antimitotic anticancer drug development. In this work, we synthesized a range of new biphenyl compounds and investigated their properties in vitro as potential antimitotic agents targeting KSP expression. Antiproliferation (MTT (=3‐(4,5‐dimethylthiazol‐2‐yl)‐2,5‐diphenyl‐2H‐tetrazolium bromide)) assays, combined with fluorescence‐assisted cell sorting (FACS) and Western blot studies analyzing cell‐cycle arrest confirmed the mechanism and potency of these biphenyl compounds in a range of human cancer cell lines. Structural variants revealed that functionalization of biphenyl compounds with bulky aliphatic or aromatic groups led to a loss of activity. However, replacement of the urea group with a thiourea led to an increase in antiproliferative activity in selected cell lines. Further studies using confocal fluorescence microscopy confirmed that the most potent biphenyl derivative identified thus far, compound 7, exerts its pharmacologic effect specifically in the M phase and induces monoaster formation. These studies confirm that chemical scope remains for improving the potency and treatment efficacy of antimitotic KSP inhibition in this class of biphenyl compounds.
Proton Hopping: A Proposed Mechanism for Myelinated Axon Nerve Impulses
Authors: Kier Lemont B. , Tombes Robert M.
Published: April 2013

Myelinated axon nerve impulses travel 100 times more rapidly than impulses in non‐myelinated axons. Increased speed is currently believed to be due to ‘hopping’ or ‘saltatory propagation’ along the axon, but the mechanism by which impulses flow has never been adequately explained. We have used modeling approaches to simulate a role for proton hopping in the space between the plasma membrane and myelin sheath as the mechanism of nerve action‐potential flow.
On the Pathways of Biologically Relevant Diatomic Gases through Proteins. Dioxygen and Heme Oxygenase from the Perspective of Molecular Dynamics
Authors: Pietra Francesco
Published: April 2013

This work deals with dioxygen (O2) binding sites and pathways through inducible human heme oxygenase (HO‐1). The experimentally known distal binding site 1, and sites 2–3 above it, could be reproduced by means of non‐deterministic random‐acceleration molecular‐dynamics (RAMD) simulations. In addition, RAMD revealed the proximal binding site 5, a deeply‐seated binding site 4, which lies behind heme, as well as a few gates communicating with the external medium. In getting from site 1 to the main gate, which lies on the protein front opposed to site 4, O2 follows chiefly the shortest direct pathway. Less frequently, O2 visits intermediate sites 2, 4, or 5 along longer pathways. A similarity between HO‐1, myoglobin, and cytoglobin in using, for diatomic gas delivery, the direct shortest pathway from the heme center to the surrounding medium, is emphasized. Otherwise, comparing other proteins and diatomic gases, each system reveals its peculiarities as to sites, gates, and pathways. Thus, relating these properties to the physiological functions of the proteins remains in general a challenge for future studies.
Congruence of Phytochemical and Morphological Profiles along an Altitudinal Gradient in Origanum vulgare ssp. vulgare from Venetian Region (NE Italy)
Authors: Giuliani Claudia , Maggi Filippo , Papa Fabrizio , Maleci Bini Laura
Published: April 2013

Plants of Origanum vulgare L. ssp. vulgare from the Veneto region (NE Italy) were selected to study the variability of the essential‐oil composition from leaves and inflorescences throughout an elevation gradient. We investigated also the morphology of non‐glandular and glandular trichomes, their distribution on the vegetative and reproductive organs, as well as the histochemistry of the secreted products, with special focus on the terpenoidic fraction.

Since glandular trichomes are prerequisite for the essential‐oil synthesis, the second objective was to establish whether its production is related to glandular hair number, and density. Essential‐oil contents decline with increasing altitude, and the micromorphological observations revealed a decrease in trichome density along the same direction. Moreover, GC/MS analysis together with principal component analysis (PCA) showed that the three investigated populations were significantly different in chemical composition. Therefore, an important interpopulation variability for low‐, mid‐, and high‐altitude sites was established, suggesting the likely occurrence of different biotypes associated with altitudinal levels.

Hence, the involvement of abiotic factors such as temperature and drought in the chemical polymorphism of O. vulgare associated with elevation is briefly discussed.
Imidazolium‐Based Organic–Inorganic Hybrid Silica as a Functional Platform Dramatically Boosts Chiral Organometallics Performance in Asymmetric Catalysis
Authors: Xia Daquan , Cheng Tanyu , Xiao Wei , Liu Ketang , Wang Zhaoliang , Liu Guohua , Li Hexing , Wang Wei
Published: April 2013

Phase‐transfer featured, imidazolium‐based, organic‐inorganic hybrid silica represents a novel functionalized platform with particularly attractive features in asymmetric catalysis. Herein, we report a chiral organorhodium‐functionalized heterogeneous catalyst. As demonstrated in the studies, it displays comparable or higher catalytic activity and enantioselectivity than its homogeneous counterpart in asymmetric transformations. The superior catalytic performance is attributed to the synergistic effect of the salient imidazolium phase‐transfer character and the confined chiral organorhodium catalytic nature in addition to the merits of mesoporous silica. Furthermore, it is more robust than other silica‐derived heterogeneous systems and can be conveniently recovered and reused at least 10 times without loss of its catalytic efficiency. These features render the catalyst particularly attractive in practice of organic synthesis. The outcomes from the study clearly show that the strategy described here offers a general approach to immobilization of chiral ligand‐derived silane onto the phase‐transfer featured imidazolium‐based organic‐inorganic hybrid silica materials with significant improving catalyst efficiency.
Epoxide Opening versus Silica Condensation during Sol–Gel Hybrid Biomaterial Synthesis
Authors: Gabrielli Luca , Russo Laura , Poveda Ana , Jones Julian R. , Nicotra Francesco , Jiménez‐Barbero Jesús , Cipolla Laura
Published: April 2013

Hybrid organic–inorganic solids represent an important class of engineering materials, usually prepared by sol–gel processes by cross‐reaction between organic and inorganic precursors. The choice of the two components and control of the reaction conditions (especially pH value) allow the synthesis of hybrid materials with novel properties and functionalities. 3‐Glycidoxypropyltrimethoxysilane (GPTMS) is one of the most commonly used organic silanes for hybrid‐material fabrication. Herein, the reactivity of GPTMS in water at different pH values (pH 2–11) was deeply investigated for the first time by solution‐state multinuclear NMR spectroscopic and mass spectrometric analysis. The extent of the different and competing reactions that take place as a function of the pH value was elucidated. The NMR spectroscopic and mass spectrometric data clearly indicate that the pH value determines the kinetics of epoxide hydrolysis versus silicon condensation. Under slighly acidic conditions, the epoxy‐ring hydrolysis is kinetically more favourable than the formation of the silica network. In contrast, under basic conditions, silicon condensation is the main reaction that takes place. Full characterisation of the formed intermediates was carried out by using NMR spectroscopic and mass spectrometric analysis. These results indicate that strict control of the pH values allows tuning of the reactivity of the organic and inorganic moities, thus laying the foundations for the design and synthesis of sol–gel hybrid biomaterials with tuneable properties.
Highly Regioselective Organocatalyzed Synthesis of Pyrazoles from Diazoacetates and Carbonyl Compounds
Authors: Wang Lei , Huang Jiayao , Gong Xiaojie , Wang Jian
Published: April 2013

A general, organocatalytic inverse‐electron‐demand [3+2] cycloaddition reaction between a range of carbonyl compounds and diazoacetates has been developed. This reaction is catalyzed by secondary amines as a “green promoter” to generate substituted pyrazoles with high levels of regioselectivity. It is noteworthy that this [3+2] cycloaddition reaction proceeds efficiently at room temperature with a simple and inexpensive catalyst. Considering the large variety and ready availability of the starting materials (e.g. ketones, β‐ketoesters, β‐diketones, and aldehydes), as well as the operational simplicity of this process, a convenient, practical, and highly modular pyrazole synthesis has been developed. We believe that this work will arouse more research interest in the organocatalytic synthesis of other biologically active heterocycles. Such studies are currently underway in our laboratory.
Ball‐Milling‐Induced Amorphization of Zeolitic Imidazolate Frameworks (ZIFs) for the Irreversible Trapping of Iodine
Authors: Bennett Thomas D. , Saines Paul J. , Keen David A. , Tan Jin‐Chong , Cheetham Anthony K.
Published: April 2013

The I2‐sorption and ‐retention properties of several existing zeolitic imidazolate frameworks (ZIF‐4, ‐8, ‐69) and a novel framework, ZIF‐mnIm ([Zn(mnIm)2]; mnIm=4‐methyl‐5‐nitroimidazolate), have been characterised using microanalysis, thermogravimetric analysis and X‐ray diffraction. The topologically identical ZIF‐8 ([Zn(mIm)2]; mIm=2‐methylimidazolate) and ZIF‐mnIm display similar sorption abilities, though strikingly different guest‐retention behaviour upon heating. We discover that this guest retention is greatly enhanced upon facile amorphisation by ball milling, particularly in the case of ZIF‐mnIm, for which I2 loss is retarded by as much as 200 °C. It is anticipated that this general approach should be applicable to the wide range of available metal–organic framework‐type materials for the permanent storage of harmful guest species.
Multi‐faceted Reactivity of Alkyltellurophenols Towards Peroxyl Radicals: Catalytic Antioxidant Versus Thiol‐Depletion Effect
Authors: Amorati Riccardo , Valgimigli Luca , Dinér Peter , Bakhtiari Khadijeh , Saeedi Mina , Engman Lars
Published: April 2013

Hydroxyaryl alkyl tellurides are effective antioxidants both in organic solution and aqueous biphasic systems. They react by an unconventional mechanism with ROO. radicals with rate constants as high as 107 M−1 s−1 at 303 K, outperforming common phenols. The reactions proceed by oxygen atom transfer to tellurium followed by hydrogen atom transfer to the resulting RO. radical from the phenolic OH. The reaction rates do not reflect the electronic properties of the ring substituents and, because the reactions occur in a solvent cage, quenching is more efficient when the OH and TeR groups have an ortho arrangement. In the presence of thiols, hydroxyaryl alkyl tellurides act as catalytic antioxidants towards both hydroperoxides (mimicking the glutathione peroxidases) and peroxyl radicals. The high efficiency of the quenching of the peroxyl radicals and hydroperoxides could be advantageous under normal cellular conditions, but pro‐oxidative (thiol depletion) when thiol concentrations are low.
Design, Synthesis, and Antibacterial Activity of Demethylvancomycin Analogues against Drug‐Resistant Bacteria
Authors: Chang Jun , Zhang Si‐Ji , Jiang Yong‐Wei , Xu Liang , Yu Jian‐Ming , Zhou Wen‐Jiang , Sun Xun
Published: April 2013

Five novel N‐substituted demethylvancomycin derivatives were rationally designed and synthesized by using a structure‐based approach. The in vitro antibacterial activities against methicillin‐resistant Staphylococcus aureus (MRSA), gentamicin‐resistant Enterococcus faecalis (GRE), methicillin‐resistant Streptococcus pneumoniae (MRS), and vancomycin‐resistant Enterococcus faecalis (VRE) were evaluated. One of the compounds, N‐(6‐phenylheptyl)demethylvancomycin (12 a), was found to exhibit more potent antibacterial activity than vancomycin and demethylvancomycin. Compound 12 a was also found to be ∼18‐fold more efficacious than vancomycin against MRSA; however, the two compounds were found to have similar efficacy against MRS. Furthermore, compound 12 a exhibited a favorable pharmacokinetic profile with a half‐life of 5.11±0.52 h, which is longer than that of vancomycin (4.3±1.9 h). These results suggest that 12 a is a promising antibacterial drug candidate for further preclinical evaluation.
Time course of arthralgia among women initiating aromatase inhibitor therapy and a postmenopausal comparison group in a prospective cohort
Authors: Castel Liana D. , Hartmann Katherine E. , Mayer Ingrid A. , Saville Benjamin R. , Alvarez JoAnn , Boomershine Chad S. , Abramson Vandana G. , Chakravarthy A. Bapsi , Friedman Debra L. , Cella David F.
Published: April 2013

BACKGROUND

More than 80,000 postmenopausal breast cancer patients in the United States each year are estimated to begin a 5‐year course of aromatase inhibitors (AIs) to prevent recurrence. AI‐related arthralgia (joint pain and/or stiffness) may contribute to nonadherence, but longitudinal data are needed on arthralgia risk factors, trajectories, and background in postmenopause. This study sought to describe 1‐year arthralgia trajectories and baseline covariates among patients with AI and a postmenopausal comparison group.

METHODS

Patients initiating AIs (n = 91) were surveyed at the time of AI initiation and at 6 repeated assessments over 1 year. A comparison group of postmenopausal women without breast cancer (n = 177) completed concomitantly timed surveys. Numeric rating scales (0–10) were used to measure pain in 8 joint pair groups (bilateral fingers, wrists, elbows, shoulders, hips, knees, ankles, and toes). Poisson regression models were used to analyze arthralgia trajectories and risk factors.

RESULTS

By week 6, the AI‐initiating group had more severe arthralgia than did the comparison group (ratio of means = 1.8, 95% confidence interval = 1.24‐2.7, P = .002), adjusting for baseline characteristics. Arthralgia then worsened further over 1 year in the AI group. Menopausal symptom severity and existing joint‐related comorbidity at baseline among women initiating AI were associated with more severe arthralgia over time.

CONCLUSIONS

Patients initiating AI should be told about the timing of arthralgia over the first year of therapy, and advised that it does not appear to resolve over the course of a year. Menopausal symptoms and joint‐related comorbidity at AI initiation can help identify patients at risk for developing AI‐related arthralgia. Cancer 2013;119:2375–2382. © 2013 American Cancer Society.
Optimization of the systemic inflammation‐based Glasgow Prognostic Score
Authors: Proctor Michael J. , Horgan Paul G. , Talwar Dinesh , Fletcher Colin D. , Morrison David S. , McMillan Donald C.
Published: April 2013

BACKGROUND

The modified Glasgow Prognostic Score (mGPS), an inflammation‐based prognostic score that uses thresholds of C‐reactive protein (> 10 mg/L) and albumin (< 35 g/L), has been found to be independently prognostic of survival in patients with cancer. The objective of the current study was to establish whether the addition of a differential leukocyte count and a high‐sensitivity C‐reactive protein measurement enhanced the prognostic value of the mGPS.

METHODS

A total of 12,119 patients who had an incidental blood sample taken between 2000 and 2007 for C‐reactive protein, albumin, and a differential leukocyte count as well as a diagnosis of cancer made within 2 years were identified. This group was studied for the prognostic value of neutrophil, lymphocyte, and platelet counts. In addition 2742 patients whose blood was sampled after the introduction of high‐sensitivity C‐reactive protein measurements were studied for the prognostic value of different thresholds.

RESULTS

Using cancer‐specific survival as an endpoint, the prognostic value of the mGPS (hazard ratio [HR], 2.61; P < .001 [area under the receiver operating characteristic curve (AUC), 0.695]) was found to be improved by the addition of neutrophil and platelet counts (HR, 4.86; P < .001 [AUC, 0.734]) and a high‐sensitivity C‐reactive protein measurement (> 3 mg/L) (HR, 5.77; P < .001 [AUC, 0.734]).

CONCLUSIONS

The results of the current study demonstrate that the addition of neutrophil and platelet counts, as well as a high‐sensitivity C‐reactive protein measurement, enhanced the prognostic value of the mGPS. Cancer 2013;119:2325–2332. © 2013 American Cancer Society.
Progress report of a randomized trial comparing long‐term survival and late toxicity of concurrent chemoradiotherapy with adjuvant chemotherapy versus radiotherapy alone in patients with stage III to IVB nasopharyngeal carcinoma from endemic regions of China
Authors: Chen Yong , Sun Ying , Liang Shao‐Bo , Zong Jing‐Feng , Li Wen‐Fei , Chen Mo , Chen Lei , Mao Yan‐Ping , Tang Ling‐Long , Guo Ying , Lin Ai‐Hua , Liu Meng‐Zhong , Ma Jun
Published: April 2013

BACKGROUND

The objective of this study was to evaluate the long‐term survival and late toxicities of concurrent‐adjuvant chemotherapy in patients with stage III through IVB nasopharyngeal carcinoma (NPC) from endemic regions of China.

METHODS

Patients with stage III to IVB NPC were assigned randomly to receive radiotherapy (RT) alone (the RT group) or RT plus concurrent adjuvant chemotherapy (the CRT group). CRT patients received concurrent cisplatin (40 mg/m2) weekly during RT followed by cisplatin (80 mg/m2) and fluorouracil (800 mg/m2 daily for 5 days) every 4 weeks for 3 cycles. The primary endpoint was overall survival.

RESULTS

In total, 316 patients underwent randomization, with 158 to each group. At a median follow‐up of 70 months, the 5‐year overall survival rate was 72% for the CRT group and 62% for the RT group (hazard ratio, 0.69; 95% confidence interval, 0.48‐0.99; P = .043). Failure‐free survival was significantly higher in the CRT group (P = .020). Most late toxicities were similar (33% vs 26%; P = .089), except for cranial neuropathy (P = .042), peripheral neuropathy (P = .041), and ear damage (P = .048), which were significantly increased in the CRT group.

CONCLUSIONS

The addition of concurrent adjuvant chemotherapy to RT provides survival benefits to patients with stage III through IVB NPC in endemic regions of China, and it does not increase most late toxicities apart from cranial neuropathy, peripheral neuropathy, and ear damage. Cancer 2013;119:2230–2238. © 2013 American Cancer Society.
Expression of ZNF148 in different developing stages of colorectal cancer and its prognostic value
Authors: Gao Xian‐Hua , Liu Qi‐Zhi , Chang Wenjun , Xu Xiao‐Dong , Du Yan , Han Yifang , Liu Yan , Yu Zhi‐Qi , Zuo Zhi‐Gui , Xing Jun‐Jie , Cao Guangwen , Fu Chuan‐Gang
Published: April 2013

BACKGROUND

It has been speculated that zinc finger protein 148 (ZNF148) is a tumor suppressor. However, to the authors' knowledge, little is known about the clinical significance of ZNF148 expression in patients with colorectal cancer (CRC). The objective of the current study was to clarify the association between ZNF148 expression and the postoperative prognosis of patients with CRC.

METHODS

Tissue microarrays containing 56 normal mucosa, 51 adenoma, 742 CRC (TNM stage I‐IV), 16 familial adenomatous polyposis, and 21 metastatic CRC specimens were examined immunohistochemically for ZNF148 expression.

RESULTS

Expression of ZNF148 was found to increase consecutively from normal mucosa to stage I CRC, and then decreased consecutively from stage I to stage IV CRC. Lower expression of ZNF148 in tumors was found to be significantly associated with lymph node metastases, advanced TNM disease stage, poor differentiation, higher rate of disease recurrence, worse overall survival (OS), and shorter disease‐free survival. High expression of ZNF148 was also associated with improved OS (P = .025) and disease‐free survival (P = .042) in patients with stages II to III CRC. On multivariate Cox analysis, lower ZNF148 expression in tumors, advanced TNM stage, colon cancer, and elevated serum carbohydrate antigen 19‐9 (CA19‐9) were found to be significant factors for a worse OS. In 16 patients with familial adenomatous polyposis, ZNF148 expression was upregulated at steps toward carcinogenesis. In 21 patients with metastatic CRC, although ZNF148 expression was higher in primary tumors compared with adjacent mucosa, its expression in metastatic tumors was significantly lower than that in primary tumors.

CONCLUSIONS

Although ZNF148 expression is related to colorectal carcinogenesis, high ZNF148 expression in patients with CRC appears to be inversely associated with malignant phenotypes and may serve as a significant prognostic factor after surgery for patients with CRC. Cancer 2013;119:2212–2222. © 2013 American Cancer Society.
Acupuncture: Could an ancient therapy be the latest advance in the treatment of lymphedema?
Authors: Lawenda Brian D. , Vicini Frank A.
Published: April 2013

Acupuncture, an ancient medical therapy, might be the latest treatment for breast cancer–related lymphedema (BCRL). In this review, you will learn about diagnostic assessments, risk factors, complete decongestive therapy, and the potential role of acupuncture for BCRL.
Strong Light‐Molecule Coupling on Plasmonic Arrays of Different Symmetry
Authors: Salomon Adi , Wang Shaojun , Hutchison James A. , Genet Cyriaque , Ebbesen Thomas W.
Published: April 2013

The strong coupling of porphyrin J‐aggregates to plasmonic nanostructures of different symmetry is investigated. The nanostructures of higher symmetry show the strongest interaction with the molecular layer, suggesting that surface plasmon mode degeneracy plays an important role in the coupling efficiency. At high coupling strengths a new, weakly dispersive mode appears which has recently been predicted theoretically to be due to long‐range energy transfer between molecules mediated by surface plasmons. These findings point to new ways for optimizing strong coupling and thereby realize its full potential for molecular and material science.
Theoretical Investigation of Generator–Collector Microwell Arrays for Improving Electroanalytical Selectivity: Application to Selective Dopamine Detection in the Presence of Ascorbic Acid
Authors: Oleinick Alexander , Zhu Feng , Yan Jiawei , Mao Bingwei , Svir Irina , Amatore Christian
Published: April 2013

Recessed generator–collector assemblies consisting of an array of recessed disks (generator electrodes) with a gold layer (collector electrode) deposited over the top‐plane insulator reportedly allow increased selectivity and sensitivity during electrochemical detection of dopamine (DA) in the presence of ascorbic acid (AA), a situation which is frequently encountered. In sensor design, the potential of the disk electrodes is set to the wave plateau of DA, whereas the plane electrode is biased at the irreversible wave plateau of AA before the onset of the DA oxidation wave. Thus, AA is scavenged but DA is allowed to enter the nanocavities to be oxidized at the disk electrodes, and its signal is further amplified by redox cycling between disk and plane electrodes. Several different theoretical approaches are elaborated herein to analyze the behavior of the system, and their conclusions are successfully tested by experiments. This reveals the crucial role of the plane‐electrode area which screens access to the recessed disks (i.e. acts as a diffusional Faraday cage) and simultaneously contributes to amplification of the analyte signal through positive feedback, as occurs in interdigitated arrays and scanning electrochemical microscopy. Simulations also allow for the evaluation of the benefits of different geometries inspired by the above design and different operating modes for increasing the sensor performance.