bluuebunny/crossref_metadata_2025_split huggingface dataset:
Optimisation of Infrared‐assisted Extraction of Rutin from Crude Flos Sophorae Immaturus Using Response Surface Methodology and HPLC Analysis
Authors: Li Fa‐jie , Ning Su‐li , Li Yan , Yu Ying‐jia , Shen Ci‐dan , Duan Geng‐li 
Published: October 2011

ABSTRACTIntroductionRutin, one of main constituents in Flos Sophorae Immaturus, has been proven to possess several pharmacological properties such as anti‐oxidant, anti‐platelet, anti‐inflammatory effects and so on. However, optimisation of the extraction of rutin from Flos Sophorae Immaturus has rarely been reported. Thus, it is important to develop an effective method to obtain maximum yields of rutin from Flos Sophorae Immaturus.ObjectiveTo develop an infrared‐assisted extraction method for maximum rutin yield from crude Flos Sophorae Immaturus using response surface methodology and HPLC analysis.MethodologyThrough single factor experiments, ranges of the main variables (including methanol concentration, liquid:solid ratio, extraction time and infrared power) affecting the extraction yield of rutin were confirmed. A Box–Behnken design consisting of 24 experimental runs and five replicates at zero point was then applied and a regression model was obtained to predict the optimal extraction yield.ResultsThe ANOVA analysis indicated that the regression equation fits very well with the actual situation. The optimal conditions were as follows: infrared power 204.90 W, liquid:solid ratio 30.00 mL/g, methanol concentration 70.00% and extraction time 4.80 min. Under optimal conditions the predicted maximum yield (125.70 mg rutin/0.5 g raw material) was consistent with the experimental value (126.32 ± 0.67 mg rutin/0.5 g raw material) (n = 3).ConclusionThe application of response surface methodology was reliable and feasible in the optimisation of infrared‐assisted extraction of rutin from crude Flos Sophorae Immaturus. Copyright © 2011 John Wiley & Sons, Ltd.
Effects of Auxins on the Production of Steroidal Alkaloids in Rapidly Proliferating Tissue and Cell Cultures of Solanum lyratum
Authors: Kuo Chung‐Io , Chao Chi‐Hsein , Lu Mei‐Kuang 
Published: October 2011

ABSTRACTIntroductionSolanum lyratum, a rare species, is used to treat cancer, tumours and warts. Plant cell and tissue culture of S. lyratum, producing steroidal alkaloids, could be useful supplements to natural sources.ObjectiveTo study the production of solanine, solanidine and solasodine by adding auxin‐type phytohormones including indole‐3‐acetic acid (IAA), indole‐3‐butyric acid (IBA), naphthaleneacetic acid (NAA) and 2,4‐dichlorophenoxyacetic acid (2,4‐D) to cell and callus cultures of S. lyratum.MethodologyMethanolic extracts were made from callus and cell cultures of S. lyratumand and analysed using RP C18 HPLC with UV detection.Results2,4‐D‐induced calli from roots led to a significant enhancement in solanine production with a value of 4.13 mg/g dry weight (DW). The maximal solanidine and solasodine levels of 6.26 and 7.69 mg/g DW were respectively obtained with IBA‐ and IAA‐treated S. lyratum cells at concentrations of 1 and 5 mg/L.ConclusionAuxins were found to be useful phytohormones for the production of steroidal alkaloids. The callus and cell culture system developed is simple and can hence be a method of production of steroidal alkaloids in S. lyratum and other Solanaceae species. Copyright © 2011 John Wiley & Sons, Ltd.
Preparation and properties of epoxy nanocomposites. Part 2: The effect of dispersion and intercalation/exfoliation of organoclay on mechanical properties
Authors: Ngo T.‐D. , Ton‐That M.‐T. , Hoa S.V. , Cole K.C. 
Published: October 2011

AbstractThe effect of the dispersion and intercalation/exfoliation of organoclay on the mechanical properties of epoxy nanocomposites was studied. The epoxy resin was EPON828 and the hardener was Jeffamine D‐230. The organoclay Cloisite 30B was used. Nanocomposites were prepared by different mixing devices that can generate different shear forces, such as a mechanical stirrer, a microfluidizer, and a homogenizer. The results indicate that the modulus increases almost linearly with the clay loading and also is improved with the quality of microdispersion, although the latter plays a less important role. On the other hand, only good dispersion can improve the strength, while poor dispersion results in loss of strength. The strength levels off above 4 wt% organoclay loading. It can be concluded that finer and more uniform dispersion increases the clay surface area available for interaction with the matrix and reduces stress concentration in the large aggregates that initiate the failure under stress. It is also observed that the presence of C30B does not significantly affect the glass transition (Tg) of the epoxy systems regardless of the level of clay dispersion and clay loading. Dynamic mechanic analysis (DMA) shows the positive effect of dispersion and intercalation/exfoliation on the storage modulus of epoxy nanocomposites (ENCs). POLYM. ENG. SCI., 2012. © 2011 Society of Plastics Engineers
Study of the effects of multi‐walled carbon nanotubes on mechanical performance and thermal stability of polypropylene
Authors: Pascual J. , Peris F. , Boronat T. , Fenollar O. , Balart R. 
Published: October 2011

AbstractCarbon nanotubes (CNTs) have been added to polypropylene (PP) matrix to improve the overall performance of composites. The mixing process has been carried out by melt compounding using a twin screw co‐rotating extruder with different CNTs amounts in the 0.5–10 wt% from a concentrated PP‐CNTs masterbatch (20 wt% CNTs). Results show a remarkable increase in tensile strength and elastic modulus while a decrease in elongation at break is detected. With regard to thermal behavior, a remarkable increase in thermal stability at high temperatures (decomposition process studied by thermogravimetric analysis) is obtained as the CNTs amount increases. In addition to this improvement, a noticeable increase in thermal stability at medium temperatures (degradation onset determined by differential scanning calorimetry, DSC) is also observed. In a similar way, other property related to thermal and mechanical performance, such as Vicat softening temperature (VST) is improved with CNTs content. The optimum balance between cost and properties seems to be in the 1–3 wt% range. POLYM. ENG. SCI., 2011. © 2011 Society of Plastics Engineers
Molecular orientation distributions during injection molding of liquid crystalline polymers: Ex situ investigation of partially filled moldings
Authors: Fang Jun , Burghardt Wesley R. , Bubeck Robert A. 
Published: October 2011

AbstractThe development of molecular orientation in thermotropic liquid crystalline polymers (TLCPs) during injection molding has been investigated using two‐dimensional wide‐angle X‐ray scattering coordinated with numerical computations employing the Larson–Doi polydomain model. Orientation distributions were measured in “short shot” moldings to characterize structural evolution prior to completion of mold filling, in both thin and thick rectangular plaques. Distinct orientation patterns are observed near the filling front. In particular, strong extension at the melt front results in nearly transverse molecular alignment. Far away from the flow front shear competes with extension to produce complex spatial distributions of orientation. The relative influence of shear is stronger in the thin plaque, producing orientation along the filling direction. Exploiting an analogy between the Larson–Doi model and a fiber orientation model, we test the ability of process simulation tools to predict TLCP orientation distributions during molding. Substantial discrepancies between model predictions and experimental measurements are found near the flow front in partially filled short shots, attributed to the limits of the Hele–Shaw approximation used in the computations. Much of the flow front effect is however “washed out” by subsequent shear flow as mold filling progresses, leading to improved agreement between experiment and corresponding numerical predictions. POLYM. ENG. SCI.,, 2011. © 2011 Society of Plastics Engineers
Cofactor‐binding sites in proteins of deviating sequence: Comparative analysis and clustering in torsion angle, cavity, and fold space
Authors: Stegemann Björn , Klebe Gerhard 
Published: October 2011

AbstractSmall molecules are recognized in protein‐binding pockets through surface‐exposed physicochemical properties. To optimize binding, they have to adopt a conformation corresponding to a local energy minimum within the formed protein–ligand complex. However, their conformational flexibility makes them competent to bind not only to homologous proteins of the same family but also to proteins of remote similarity with respect to the shape of the binding pockets and folding pattern. Considering drug action, such observations can give rise tounexpected and undesired cross reactivity. In this study, datasets of six different cofactors (ADP, ATP, NAD(P)(H), FAD, and acetyl CoA, sharing an adenosine diphosphate moiety as common substructure), observed in multiple crystal structures of protein–cofactor complexes exhibiting sequence identity below 25%, have been analyzed for the conformational properties of the bound ligands, the distribution of physicochemical properties in the accommodating protein‐binding pockets, and the local folding patterns next to the cofactor‐binding site. State‐of‐the‐art clustering techniques have been applied to group the different protein–cofactor complexes in the different spaces. Interestingly, clustering in cavity (Cavbase) and fold space (DALI) reveals virtually the same data structuring. Remarkable relationships can be found among the different spaces. They provide information on how conformations are conserved across the host proteins and which distinct local cavity and fold motifs recognize the different portions of the cofactors. In those cases, where different cofactors are found to be accommodated in a similar fashion to the same fold motifs, only a commonly shared substructure of the cofactors is used for the recognition process. Proteins 2012. © 2011 Wiley Periodicals, Inc.
Uncertainty in carbon exchange modelling in a forest canopy due to kB−1 parametrizations
Authors: Hong J. , Kim J. , Byun Y. H. 
Published: October 2011

AbstractThe difference in turbulent transfer efficiency between momentum and scalars, represented by kB−1, has been the subject of considerable interest in micrometeorology, and various parametrizations have been proposed to address this issue. The simple kB−1 parametrizations that are based on either empirical formulations or K‐theory are still popularly used in the land surface models despite their theoretical deficiencies. Moreover, the impact of the uncertainty in this parameter on modelling surface carbon exchange has not been previously estimated. In this study, we examined the uncertainties of the simulated gross primary productivity (GPP), ecosystem respiration (RE), and net ecosystem exchange (NEE ≡ RE–GPP) for a forest canopy due to kB−1 parametrizations. The tested parametrizations included not only the schemes that set kB−1 as a constant or as a function of only the Reynolds number (popularly used in the land surface model), but also the schemes that express kB−1 as a function of plant phenology derived from the Lagrangian theory. Except for parametrizations that produced aerodynamic resistance as large as canopy resistance over a tall forest canopy, the variabilities of GPP and RE induced by kB−1 parametrizations were less than 2% of the annual GPP and RE, respectively. Nevertheless, the model produced approximately 10% variability of NEE values with changes in the kB−1 parametrizations (203±24 g C m−2year−1) because the simulated RE was less sensitive to the kB−1 parametrizations than the simulated GPP due to the negative feedback among kB−1, temperature, and RE. Our findings reveal that kB−1 parametrizations should be suitably applied in land surface modelling for better simulation of the global carbon cycle. Copyright © 2011 Royal Meteorological Society and British Crown Copyright, the Met Office
Receptor binding affinity based comparative QSAR study of testosterone derivatives
Authors: Khan Ahmad Khalid Raza , Khan Suhail Ahmad , Mishra Sunil , Khan Tajuddin , Ansari Mohiuddin , Khan Badshah Hasan 
Published: October 2011

AbstractThe quantitative structure activity relationship models of 22 testosterone derivatives have been made with the help of topological and quantum chemical parameters. The molecular modeling and geometry optimization have been carried out with CAChe Pro software. The calculations of topological and quantum chemical parameters have been done by MOPAC 2007. The statistical parameters are calculated by STATISTICA and SSP software. The study indicates that the topological parameters better predict the receptor binding affinity of testosterone derivatives, whereas quantum chemical parameters better predict androgenic potency of testosterone derivatives as indicated by correlation coefficient, standard error, standard error of estimation, p value, t value, and degree of freedom of the quantitative structure activity relationship (QSAR) models. The predicted activity values obtained by these QSAR models are close to observed activity. © 2011 Wiley Periodicals, Inc. Int J Quantum Chem, 2012
Pharmacology of P2X receptors
Authors: Syed Nawazish‐i‐Husain , Kennedy Charles 
Published: October 2011

AbstractP2X receptors are ligand‐gated cation channels that mediate many of the extracellular actions of adenosine 5′‐triphosphate (ATP). The genes encoding seven different P2X subunits, P2X1–7, have been cloned and when expressed alone all P2X subunits form functional receptors, except P2X6, which usually only assembles in a heteromeric form. Subunits can also interact with each other and to date seven functional heteromultimers with pharmacological and/or biophysical properties that differ from the individual homomultimers have been identified: P2X2/3, P2X4/6, P2X1/5, P2X2/6, P2X1/4, P2X1/2, and possibly P2X4/7. These are distributed widely throughout the body and are involved in many physiological and pathophysiological processes. ATP is an agonist at all subtypes and few selective agonists and no useful antagonists were available when P2X receptors were first defined. Subsequently, nonselective antagonists, such as suramin and PPADS, were discovered and since then, and particularly in the past decade, numerous potent and subtype‐selective antagonists have been developed. These include NF449 and RO‐1 at P2X1 receptors; PSB‐1011 at P2X2 receptors; A317491, compound A, RO‐3, and AF‐353 at P2X3 and P2X2/3 receptors; 5‐BDBD at P2X4 receptors; and A740003, A438079, A804598, GSK314181A, AZ10606120, AZ11645373, AZD‐9056, CE‐224535, and EVT‐401 at P2X7 receptors. The therapeutic usefulness of these compounds is currently being investigated in a variety of disorders, including thrombosis (P2X1), chronic neuropathic and inflammatory pain (P2X3, P2X2/3, P2X4, P2X7), dysfunctional urinary bladder (P2X1, P2X3, P2X2/3), rheumatoid arthritis and osteoarthritis (P2X7), and depression (P2X7). WIREs Membr Transp Signal 2012, 1:16–30. doi: 10.1002/wmts.1For further resources related to this article, please visit the WIREs website.
Calcium channels of schistosomes: unresolved questions and unexpected answers
Authors: Salvador‐Recatalà Vicenta , Greenberg Robert M. 
Published: October 2011

AbstractParasitic flatworms of the genus Schistosoma are the causative agents of schistosomiasis, a highly prevalent, neglected tropical disease that causes significant morbidity in hundreds of millions of people worldwide. The current treatment of choice against schistosomiasis is praziquantel (PZQ), which is known to affect Ca2+ homeostasis in schistosomes, but which has an undefined molecular target and mode of action. PZQ is the only available antischistosomal drug in most parts of the world, making reports of PZQ resistance particularly troubling. Voltage‐gated Ca2+ (Cav) channels have been proposed as possible targets for PZQ, and, given their central role in the neuromuscular system, may also serve as targets for new anthelmintic therapeutics. Indeed, ion channels constitute the majority of targets for current anthelmintics. Cav channel subunits from schistosomes and other platyhelminths have several unique properties that make them attractive as potential drug targets, and that could also provide insights into structure–function relationships in, and evolution of, Cav channels. WIREs Membr Transp Signal 2012, 1:85–93. doi: 10.1002/wmts.19For further resources related to this article, please visit the WIREs website.
Kainate receptors in developing presynaptic terminals
Authors: Lauri Sari , Taira Tomi 
Published: October 2011

AbstractThe formation of neuronal circuitry involves a period of activity‐dependent fine‐tuning and maturation of the connectivity, during which some of the nascent synapses are strengthened and others are eliminated. Many of the mechanisms utilized in this process are developmentally downregulated and replaced with synaptic machinery typical of adult‐type transmission. The kainate‐type of ionotropic glutamate receptors (KARs) modulate transmission and excitability of the neuronal networks in a complex manner, and thereby contribute to generation of patterned activity critical for plasticity and information processing. The expression, activation, and signaling of KARs is altered during early postnatal development and it is becoming evident that these receptors have specific functions during synapse maturation. In particular, developmentally restricted functions have been described for presynaptically located KARs in both areas CA3 and CA1 of the hippocampus. Although the exact mechanisms and receptor subunits responsible for these effects are still largely unclear, it is evident that KARs regulate synapse dynamics and plasticity in the neonatal brain and might be critically important in linking neuronal activity to morphogenesis at immature synapses. WIREs Membr Transp Signal 2012, 1:45–55. doi: 10.1002/wmts.3For further resources related to this article, please visit the WIREs website.
Horizontal transfer of RNAs: exosomes as mediators of intercellular communication
Authors: Ramachandran Saraswathi , Palanisamy Viswanathan 
Published: October 2011

AbstractMulticellular organisms are similar to biological communities, consisting of various cell types; thus, inter‐cell communication is critical for the functioning of the whole system that ultimately constitutes a living being. Conventional models of cellular exchange include signaling molecules and direct contact‐mediated cell communications. Exosomes, small vesicles originating from an inward budding of the plasma membrane, represent a new avenue for signaling between cells. This interchange is achieved by packaging RNA species into exosomes endowed with specific cell surface‐targeting motifs. The delivered RNA molecules are functional, and mRNA can be translated into new proteins, while microRNAs (miRNAs) target host mRNAs in the recipient cell. RNA involved in transmitting information or molecules between cells is called exosomal RNA (esRNA). This review summarizes the characteristics of exosomes, specifically focusing on their role in the horizontal transfer of cellular information. WIREs RNA 2012, 3:286–293. doi: 10.1002/wrna.115This article is categorized under:

Regulatory RNAs/RNAi/Riboswitches > Regulatory RNAs
RNA in Disease and Development > RNA in Development
Crystal Growth of Al‐Rich Complex Metallic Phases in the System Al–Cr–Fe Using the Czochralski Method
Authors: Bauer Birgitta , Gille Peter 
Published: October 2011

AbstractComplex metallic phases in the Al–Cr–Fe system are considered to be interesting because of their enhanced resistance against corrosion. Single crystal growth of the Al4(Cr,Fe) and Al13(Fe,Cr)4 phases, which is a prerequisite for detailed studies is presented herein for the first time. Along with their binary end members Al4Cr and Al13Fe4 growth of cm3‐size crystals was achieved by using the Czochralski method from Al‐rich solutions at temperatures of approximately 1000 °C. Special emphasis is put on the refinement of the Al‐rich corner of the ternary phase diagram in determining the 1000 °C equilibria between the incongruent melts and the corresponding ternary solid solutions. Our findings confirm earlier data on the existence region of Al13(Fe,Cr)4, but significantly differ from those with respect to the so called Al4(Cr,Fe) phase. It is shown that the existence region of Al4(Cr,Fe) decomposes into four regions of structurally different phases depending on the Cr/Fe ratio. Binary μ‐Al4Cr crystallizes in the hexagonal space group P63/mmc and can dissolve only up to about 1 At‐% iron. More Fe‐rich alloys crystallize in the orthorhombic space group Cmcm (about 2 At‐% iron) or Immm (containing between 3 and about 6 At‐% iron). For crystals containing about 7 At‐% iron the structure belongs to the space group R$\bar{3}$. The grown single crystals were characterized by electron probe microanalysis revealing only weak segregation effects. The structural perfection of the orthorhombic phase was studied using X‐ray topography with the Lang technique. Significant anisotropic properties of this phase allow to discuss structural similarities with decagonal quasicrystals.
THE EFFECTS OF PRUNING AT DIFFERENT TIMES ON THE GROWTH, PHOTOSYNTHESIS AND YIELD OF CONILON COFFEE (COFFEA CANEPHORA) CLONES WITH VARYING PATTERNS OF FRUIT MATURATION IN SOUTHEASTERN BRAZIL
Authors: MORAIS L. E. , CAVATTE P. C. , MEDINA E. F. , SILVA P. E. M. , MARTINS S. C. V. , VOLPI P. S. , JÚNIOR S. ANDRADE , MACHADO FILHO J. A. , RONCHI C. P. , DAMATTA F. M. 
Published: October 2011

SUMMARYThe economics of coffee plantations is intrinsically linked to pruning, which can improve the canopy architecture and thereby increase productivity. However, recommended pruning times on conilon coffee plantations have been made on an entirely empirical basis. In this study, by evaluating growth, photosynthetic gas exchanges, starch accumulation and crop productivity, the effects of pruning at different times between harvest and flowering were investigated for six conilon coffee clones with distinct stages of fruit maturation (early, intermediate and late). Clones with an early maturation stage were pruned at four different times: 0, 30, 60 and 90 days after harvest (DAH). Intermediate clones were pruned at 0, 30 and 60 DAH, and late clones were pruned at 0 and 30 DAH. Overall, the rates of shoot growth and net photosynthesis, the stomatal conductance and the crop yield were not affected by the pruning treatments in any of the clones. In addition, pruning times did not affect the concentrations of starch or the photochemical efficiency of photosystem II. The carbon isotope composition ratio was marginally affected by the treatments. These results suggest that the pruning time after harvests is relatively unimportant and pruning operations can be scheduled to optimise the use of labour, which directly impacts the production costs of coffee.