bluuebunny/crossref_metadata_2025 huggingface dataset:
Conservation area networks for the Indian region: Systematic methods and future prospects
Authors: Sarkar Sahotra , Mayfield Michael , Cameron Susan , Fuller Trevon , Garson Justin
Published: March 2008

We present a framework for systematic conservation planning for biodiversity with an emphasis on the Indian context. We illustrate the use of this framework by analyzing two data sets consisting of environmental and physical features that serve as surrogates for biodiversity. The aim was to select networks of potential conservation areas (such as reserves and national parks) which include representative fractions of these environmental features or surrogates. The first data set includes the entire subcontinent while the second is limited to the Eastern Himalayas. The environmental surrogates used for the two analyses result in the selection of conservation area networks with different properties. Tentative results indicate that these surrogates are successful in selecting most areas known from fieldwork to have high biodiversity content such as the broadleaf and subalpine conifer forests of the Eastern Himalayas. However, the place-prioritization algorithm also selected areas not known to be high in biodiversity content such as the coast of the Arabian Sea. Areas selected to satisfy a 10% target of representation for the complete surrogate set provide representation for 46.03% of the ecoregions in the entire study area. The algorithm selected a disproportionately small number of cells in the Western Ghats, a hotspot of vascular plant endemism. At the same target level, restricted surrogate sets represent 33.33% of the ecoregions in the entire study area and 46.67% of the ecoregions in the Eastern Himalayas. Finally, any more sophisticated use of such systematic methods will require the assembly of Geographical Information Systems (GIS)-based biogeographical data sets on a regional scale.

Key words: Indian biodiversity, Eastern Himalayas, complementarity, area prioritization, reserve selection, surrogacy

Himalayan Journal of Sciences Vol.4(6) 2007 p.27-40
Flow-assisted surgical cerebral revascularization
Authors: Ashley William W. , Amin-Hanjani Sepideh , Alaraj Ali , Shin John H. , Charbel Fady T.
Published: March 2008

✓Extracranial–intracranial bypass surgery has advanced from a mere technical feat to a procedure requiring careful patient selection and a justifiable decision-making paradigm. Currently available technologies for flow measurement in the perioperative and intraoperative setting allow a more structured and analytical approach to decision making. The purpose of this report is to review the use of flow measurement in cerebral revascularization, presenting algorithms for flow-assisted surgical planning, technique, and surveillance.
Palladium‐Catalyzed Direct Arylations of 1,2,3‐Triazoles with Aryl Chlorides using Conventional Heating
Authors: Ackermann Lutz , Vicente Rubén , Born Robert
Published: March 2008

Generally applicable, palladium‐catalyzed direct arylations of 1,2,3‐triazoles with aryl chlorides were accomplished through conventional heating at reaction temperatures of 105–120 °C. Thereby, intra‐ and intermolecular CH bond functionalizations were achieved with a variety of differently substituted chlorides as electrophiles, bearing numerous valuable functional groups.
Palladium‐Catalyzed Stille Cross‐Coupling Reaction of Aryl Chlorides using a Pre‐Milled Palladium Acetate and XPhos Catalyst System
Authors: Naber John R. , Buchwald Stephen L.
Published: March 2008

A highly active catalyst system based upon a biaryl monophosphine ligand, XPhos, for the palladium‐catalyzed Stille reaction has been developed. This method allows for the coupling of aryl chlorides with a range of tributylarylstannanes to produce the corresponding biaryl compounds in good to excellent yields (61–98%) in short reaction times (4 h). Palladium(II) acetate [Pd(OAc)2] and XPhos in a 1:1.1 ratio were milled into a fine powder that was used as pre‐catalyst for these reactions.
Improved Syntheses of Versatile Ruthenium Hydridocarbonyl Catalysts Containing Electron‐Rich Ancillary Ligands
Authors: Beach Nicholas J. , Dharmasena Ureshini L. , Drouin Samantha D. , Fogg Deryn E.
Published: March 2008

Clean, high‐yield routes are established to the important catalyst chlorobis(tricyclohexylphosphine)ruthenium hydridocarbonyl [RuHCl(CO)(PCy3)2] 2 and its N‐heterocyclic carbene (NHC) derivatives RuHCl(CO)(NHC)(PCy3) (3a: NHC=IMes; 3b, NHC=H2IMes; IMes=1,3‐dimesitylimidazol‐2‐ylidene). These complexes are obtained by treating chlorotris(tricyclohexylphosphine)ruthenium hydridocarbonyl [RuHCl(CO)(PPh3)3] 1 with tricyclohexylphosphine [PCy3], or with the appropriate NHC ligand, then PCy3. Advantages over prior routes to these complexes lie in the high yields from a conveniently accessible precursor, the absence of by‐products that otherwise prove difficult to remove, and the short reaction times under experimentally convenient conditions.
Synthesis by a single‐step swelling process and characterization of micrometer‐sized polychloromethylstyrene/poly(butyl methacrylate) hemispherical composite particles of narrow size distribution
Authors: Baruch‐Sharon Sigal , Margel Shlomo
Published: March 2008

Polychloromethylstyrene (PCMS) micrometer‐sized particles of narrow size distribution were prepared by the dispersion polymerization of chloromethylstyrene in a mixture of ethanol and dimethyl sulfoxide. Micrometer‐sized PCMS/poly(butyl methacrylate) hemispherical composite particles of narrow size distribution were prepared by a single‐step swelling process of the uniform PCMS template particles with emulsion droplets of butyl methacrylate (BMA) containing benzoyl peroxide, followed by the polymerization of BMA at 73°C within the swollen template particles. The effects of various polymerization parameters, for example, BMA volume, initiator type and concentration, and toluene as the swelling solvent, on the properties (size and size distribution, morphology, polymerization yield, and composition) of the hemispherical composite particles were elucidated. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Trial‐manufacture and UV‐blocking property of ZnO nanorods on cotton fabrics
Authors: Xu Bi , Cai Zaisheng
Published: March 2008

Oriented ZnO nanorod arrays were prepared on cotton fabrics via a simple two‐step process. The ZnO nanocrystals were first synthesized and coated onto cotton substrates by dip‐pad‐cure process as nucleation seeds, followed by hydrothermal ZnO growth in aqueous solution of zinc nitrate hydrate and hexamethylenetetramine. Field‐emission scanning electron microscope images showed the typical ZnO nanorods were 40–60 nm in diameter and 300–400 nm in length. Meanwhile, a few mesoscale ZnO nanorods with diameter of 150–200 nm, length of 600–800 nm, and their congeries were also observed on the cotton fabrics. X‐ray diffraction result and Raman spectrum indicated the as‐prepared nanorods were of high quality and defect free with hexagonal wurtzite ZnO structure. The as‐obtained cotton sample was also characterized with energy dispersive spectroscopy and no impurities were detected. The ZnO nanorods grown on cotton fabrics possessed an ultrahigh ultraviolet protection factor of 379.14 in this study, indicating an excellent protection against ultraviolet radiation in comparison with the untreated cotton fabrics. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Study of the conductive paths of carbon‐black‐filled polyethylene composites by the alternating‐current impedance method
Authors: Sun Daoxing , Wei Yanyan
Published: March 2008

Conductive carbon‐black (CB)‐filled polyethylene composites were prepared after irradiation with a cobalt 60 source. The conductive composites were characterized by alternating‐current impedance spectroscopy, and the conductive mechanism of the conductive composites was analyzed in terms of a mathematical model. The values of the conductive ability, conductive style, sum of the electrical resistance of the continuous CB chains, electrical resistivity of the CB chains with one gap or a few small gaps, room‐temperature resistance, and slopes of the conductive composites were calculated. The investigation indicated that there existed continuous (contacting)‐path CB chains, small‐gap chains, and larger gap CB chains inthe composites, and the conductive paths in the composites were considered to be a three‐dimensional network. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Preparation and characterization of novel Ce(III)‐gelatin complex
Authors: Huang Yaqin , Wei Tingting , Ge Youyong
Published: March 2008

A new complex of cerium(III) [Ce(III)] with gelatin has been prepared in an aqueous solution. The FTIR, UV–vis, and XRD studies of the Ce(III)‐gelatin complex revealed that the carboxyl groups of gelatin coordinated to Ce(III). The thermal property of the complex was investigated by thermo gravimetric analysis. It was discovered that the thermally decomposed rate of the complex decreased obviously. In addition, the antimicrobial activity of the complex to Staphylococcus aureus, Pseudomonas aeruginosa, and Escherachia coli was measured and found that its minimal inhibitory concentration (MIC) to the growth of bacterium was 350 μg/mL, which was almost the same as Ce(III) ion. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Water flow through the polypropylene‐based geotextiles
Authors: Patanaik Asis , Anandjiwala Rajesh D.
Published: March 2008

This article presents the results from a study on the cross‐plane water flow through the needle punched nonwoven geotextiles produced from polypropylene fibers. Different types of nonwoven geotextiles are produced by varying the processing parameters during the needle punching process. The pore characteristics and the cross‐plane water flow (or permeability) through the nonwoven geotextiles are measured by liquid extrusion porometry and water permeability tester, respectively. The water flow velocities through the geotextiles are predicted by the finite element analysis. There is a good correlation between the average velocity data obtained from water permeability test and theoretical prediction based on finite element analysis. The pore characteristics play an important role in water permeability behavior of nonwoven geotextiles. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
An ethical solution to the challenges in teaching anatomy with dissection in the Chinese culture
Authors: Zhang Luqing , Wang Yunfeng , Xiao Ming , Han Qunying , Ding Jiong
Published: March 2008

Universities and medical schools in China are faced with an ongoing shortage of cadavers for education and research because of insufficient numbers of cadaver donations. This article will examine the main obstacles to cadaver donation in the Chinese culture. These include superstitious traditional views about the body, a lack of legislation regulating donations, and a deficiency of effective channels for cadaver donations. Cadaver dissection has always been the most important method of teaching anatomy to medical students. Today, ethics courses have also become essential to a complete medical education. Contemporary physicians need to be equipped to navigate the myriad of moral and ethical issues inherent to modern medicine. In China, cadaver donations lag behind those in other countries, threatening to create valid disadvantages in medical education. New legislation and public education are necessary to remove cultural barriers and change Chinese views on cadaver donation. For this reason, the Department of Human Anatomy at Nanjing Medical University has established the “Educational Center for Medical Ethics.” The goal of the Center is to promote proper respect for cadavers used for medical research and education, cherish the human lives the cadavers represent, and gain the trust of potential donors. Anat Sci Ed 1:56–59, 2008. © 2008 American Association of Anatomists.
Fetal ethanol exposure activates protein kinase a and impairsShhexpression in prechordal mesendoderm cells in the pathogenesis of holoprosencephaly
Authors: Aoto Kazushi , Shikata Yayoi , Higashiyama Daisuke , Shiota Kohei , Motoyama Jun
Published: March 2008

BACKGROUND:

In humans, fetal ethanol exposure can cause holoprosencephaly (HPE), one of the most common birth defects that is characterized by brain, facial, and oral abnormalities. However, the pathogenesis of HPE is not clear. In the present study, we investigated the teratogenic mechanism of ethanol‐induced brain and facial malformations in mice.

METHODS:

Pregnant C57BL/6J mice were administered ethanol on E7 and facial and brain malformations were characterized on E10.5. We examined the effect of fetal ethanol exposure onShhexpression and activation of protein kinase A (PKA) because mutations in the humanShhgene are the most frequent cause of autosomal‐dominant inherited HPE and PKA is a potent endogenous antagonist of Shh signaling.

RESULTS:

Fetal ethanol exposure on E7 induced severe midline defects characteristic of HPE. Ethanol exposure impairedShhexpression and induced excessive apoptosis only along the anterior edge of the prechordal mesendoderm (PME). In addition, ethanol activated PKA in anterior PME cells. Pretreatment of embryos with antioxidants, such as vitamins C or E, prevented the development of ethanol‐induced HPE.

CONCLUSIONS:

Shhexpression in PME cells is involved in the pathogenesis of ethanol‐induced HPE. Ethanol may impairShhexpression indirectly by activating PKA. The inhibition of excessive apoptosis in PME cells by antioxidants implies that oxidative stress may underlie the teratogenic actions of ethanol. Thus, antioxidant treatment may be a simple preventative measure that could reduce the incidence of HPE following fetal ethanol exposure. Birth Defects Research (Part A), 2008. © 2008 Wiley‐Liss, Inc.
Polymeric particles conjugated with a ligand to VCAM‐1 exhibit selective, avid, and focal adhesion to sites of atherosclerosis
Authors: Deosarkar Sudhir P. , Malgor Ramiro , Fu Jie , Kohn Leonard D. , Hanes Justin , Goetz Douglas J.
Published: March 2008

The increased expression of VCAM‐1 on endothelial segments within plaque regions could be used as a target to deliver polymeric drug carriers selectively to sites of atherosclerosis. We probed the hypothesis that polymeric particles conjugated with a ligand for VCAM‐1 exhibit selective and avid adhesion to sites of atherosclerosis. Particles made from polystyrene or the biodegradable polymer poly(sebacic acid)‐block‐polyethylene glycol (PSA‐PEG) were conjugated with an antibody to VCAM‐1 (α‐VCAM‐1) or IgG (negative control). The particles were injected into the jugular vein of ApoE−/− (a murine model of atherosclerosis) or wild type mice and their adhesion to the aorta determined. α‐VCAM‐1 particles exhibited significantly greater adhesion to ApoE−/− mouse aorta [32 ± 5 (mean ± SEM) particles/mm2 for polystyrene particles and 31 ± 7 particles/mm2 for PSA‐PEG particles] compared to the level of adhesion to wild type mouse aorta (18 ± 1 particles/mm2 for polystyrene particles and 6 ± 1 particles/mm2 for PSA‐PEG particles). Within ApoE−/− mice, the α‐VCAM‐1 particles exhibited significantly greater adhesion to the aorta (32 ± 5 particles/mm2 for polystyrene particles and 31 ± 7 particles/mm2 for PSA‐PEG particles) compared to the adhesion of IgG particles (1 ± 1 particles/mm2 for polystyrene particles and 2 ± 1 particles/mm2 for PSA‐PEG particles). Detailed analysis of the adhesion revealed that α‐VCAM‐1 particles exhibited focal adhesion to plaque regions, in particular the periphery of the plaques, within the ApoE−/− mouse aorta. Combined the data demonstrate that polymeric particles conjugated with a ligand to VCAM‐1 exhibit selective, avid and focal adhesion to sites of atherosclerosis providing strong evidence that VCAM‐1 ligand bearing polymeric particles could be used for targeting drugs selectively to atherosclerotic tissue. Biotechnol. Bioeng. 2008;101: 400–407. © 2008 Wiley Periodicals, Inc.
A Study of the Binding Energies of Efavirenz to Wild‐Type and K103N/Y181C HIV‐1 Reverse Transcriptase Based on the ONIOM Method
Authors: Srivab Pensri , Hannongbua Supa
Published: March 2008

A three‐layered ONIOM model was used to study the interactions between efavirenz and the binding sites of HIV‐1 reverse transcriptase (RT): wild‐type and double mutant K103N/Y181C enzyme forms. Binding energies were determined and compared to describe the loss of activity of efavirenz with the mutant HIV‐1 RT binding pocket. The calculated binding energy for the efavirenz–K103N/Y181C HIV‐1 RT complex is less than that with the wild‐type complex by approximately 8 kcal mol−1. The interaction energies, calculated at the MP2/6‐31G(d,p) level between efavirenz and individual residues surrounding the binding pocket of the K103N/Y181C enzyme, demonstrate that the attractive interactions between efavirenz and residue positions 101 and 103 were less than those for wild‐type RT by 5.52 and 3.62 kcal mol−1, respectively. Understanding these interactions could be useful in the design of inhibitors specific for the HIV‐1 RT allosteric site and that have greater potency against the mutant enzyme.
Localized intermolecular zero‐quantum coherence spectroscopy in vivo
Authors: Balla David Z. , Faber Cornelius
Published: March 2008

Resolution enhancement in NMR spectra, acquired in spatially or temporally varying magnetic fields, can be achieved with 2D pulse sequences detecting intermolecular zero‐quantum coherences (iZQC). The insensitivity towards long range field distortions renders these methods particularly appealing for in vivo NMR spectroscopy, where ample sources of field inhomogeneities are encountered. This article provides a comprehensive description of iZQC spectroscopy, following a classical treatment. A pictorial explanation is given of how iZQC signal is formed under the action of the distant dipolar field in the sample and how this local refocusing process leads to line narrowing in the indirect dimension of 2D spectra. Signal evolution and peak positions in the spectra are analyzed by solving the modified Bloch equations. Finally, it is explained how water suppression and localization can be combined with the iZQC preparation sequence, and recent in vivo applications are discussed. The given examples illustrate that iZQC spectroscopy can provide either resolution or sensitivity enhancement in vivo. © 2008 Wiley Periodicals, Inc. Concepts Magn Reson Part A 32A: 117–133, 2008.
Optical detection of NMR in organic fluids
Authors: Meriles Carlos A.
Published: March 2008

In a recent publication, Romalis and coworkers report the detection of nuclear magnetic resonance (NMR) in water using optical Faraday rotation (OFR). This groundbreaking result sets the stage for a new class of experiments on a range of samples largely exceeding that previously thought possible. In this manuscript, I review the fundamentals behind Faraday rotation including those aspects of the theory that lead to detection of NMR. I also describe the setup needed for these experiments as well as some possible strategies to improve detection sensitivity. In particular, I discuss the use of an optical cavity as a way to amplify the Faraday rotation induced by a ∼1 cm long fluid sample in the Voigt geometry. With enhancement factors of order ∼103, detection of the nuclear spin signal appears as a challenging though possible experiment, provided the dissimilar physical constraints imposed by a high‐finesse, tunable cavity and high‐field NMR are simultaneously fulfilled. © 2008 Wiley Periodicals, Inc. Concepts Magn Reson Part A 32A: 79–87, 2008.
Expression and localization of the prion protein PrPC in the olfactory system of the mouse
Authors: Le Pichon Claire E. , Firestein Stuart
Published: March 2008

The normal physiological function of the prion protein PrPC remains elusive despite its widespread expression, particularly throughout the nervous system. A critical step toward identifying its function is to precisely localize its pattern of expression. Historically, the immunolocalization of PrPC has proved to be notoriously difficult and nonconsensual. We have thus undertaken a detailed expression analysis by means of a combination of in situ hybridization, knockout mice, and immunohistochemistry, using recently generated highly specific antibodies. We have attempted to accurately localize PrPC expression in a tissue that is highly structured and of crucial behavioral importance to mice, the olfactory system. We found that PrPC was expressed in both peripheral and central neurons of the olfactory system and that its distribution was axonal‐specific in both olfactory sensory neurons of the olfactory epithelium and mitral cells of the olfactory bulb. Our detailed expression analysis and the axonal localization we observed may provide important hints toward potential functions of PrPC. J. Comp. Neurol. 508:487–499, 2008. © 2008 Wiley‐Liss, Inc.
Spectroscopic Properties of a Strongly Anharmonic Mannich Base N‐oxide
Authors: Jezierska Aneta , Panek Jarosław J. , Koll Aleksander
Published: March 2008

Car–Parrinello molecular dynamics simulations in vacuum and in the solid state are performed on a strongly anharmonic system, namely, 2‐(N‐diethylamino‐N‐oxymethyl)‐4,6‐dichlorophenol, to investigate its molecular and spectroscopic properties. The investigated compound contains two slightly different molecules in the crystal cell with very short intramolecular hydrogen bonds (of 2.400 and 2.423 Å), as determined previously by neutron diffraction. The vibrational properties of the compound are studied on the basis of standard approaches, that is, Fourier transformation of the autocorrelation functions of the atomic velocities and dipole moments. Then, the trajectory obtained from ab initio molecular dynamics is sampled and the obtained snapshots are used to solve the vibrational Schrödinger equations and to calculate the OH stretching envelope as a superposition of the 0→1 transition. Using an envelope method, the a posteriori quantum effects are included in the OH stretching. In addition, NMR spectra are calculated also using the obtained snapshots. One‐ and two‐dimensional potentials of mean force (1D and 2D pmf) are derived to explain the details of the proton dynamics. The computational results are supported by NMR experimental data. In addition, the calculated results are compared with previously published X‐ray, neutron diffraction, and spectroscopic descriptions. A detailed analysis of the bridged proton′s dynamics is thus obtained. The application of 1D and 2D pmf in a system with a strong bridged‐proton delocalization is also demonstrated.
Pd on Porous Glass: A Versatile and Easily Recyclable Catalyst for Suzuki and Heck Reactions
Authors: Schmöger Christine , Szuppa Tony , Tied Antje , Schneider Franziska , Stolle Achim , Ondruschka Bernd
Published: March 2008

The catalytic activity of Pd supported on porous glass was studied for both Suzuki and Heck reactions under aerobic conditions, with particular focus on the Suzuki coupling. The reactions were carried out in water under microwave irradiation. The effects of the catalyst preparation process (calcination time and temperature), as well as the base, substrate, and boron compound used on the coupling reaction were investigated in relation to the reusability of the catalyst. Various bases promote the Suzuki coupling of phenylboronic acid with bromophenol very effectively resulting in quantitative conversion and excellent selectivity for the coupling product. However, most bases lead to deactivation of the catalyst after the first reaction cycle and the catalyst must be reactivated before reuse. Therefore, excellent conversions and selectivities for individual reactions are not sufficient to conclude if the chosen conditions are suitable for a given reaction, but results from recycling studies have to be considered also.
A 2‐year‐old child's memory of hospitalization during early infancy
Authors: Solter Aletha
Published: March 2008

A child who had had surgery at 5 months of age, and who had been treated at the time for post‐traumatic symptoms (reported in a previous paper by the author), was interviewed 2 years later and almost 3 years later to test for possible verbal recall of his hospitalization. He appeared to have some memories of the experience at 29 months of age, and he was able to superimpose verbal labels onto the preverbal memories. At 40 months of age, however, the memories were no longer verbally accessible. The results are discussed in the context of different theories of encoding, storage, retrieval, and loss of early memories. The findings from this study support other findings indicating that there appears to be some form of long‐term memory in place early in life, at least for highly salient, traumatic events. There may be one memory system for traumatic memories, fully functional at birth, and a later developing, different system for neutral memories. It is further hypothesized that there may be a sensitive period around 2–3 years of age for the recall of early traumatic memories, and that verbal recall is more likely to be present in verbally precocious children during that period. Copyright © 2008 John Wiley & Sons, Ltd.
Osteoprotegerin decreases human osteoclast apoptosis by inhibiting the TRAIL pathway
Authors: Chamoux Estelle , Houde Nicolas , L'Eriger Karine , Roux Sophie
Published: March 2008

Osteoprotegerin (OPG) is a secreted decoy receptor that recognizes RANKL, and blocks the interaction between RANK and RANKL, leading to the inhibition of osteoclast differentiation and activation. As OPG is a major inhibitor of bone resorption, we wondered whether OPG could modulate osteoclast survival/apoptosis. Osteoclast apoptosis was evaluated by adding various doses of OPG to human osteoclast cultures obtained from cord blood monocytes. Surprisingly, apoptosis decreased after adding the OPG. We hypothesized that OPG may block its second ligand, TRAIL, which is involved in osteoclast apoptosis. We showed that osteoclasts expressed TRAIL, and that TRAIL levels in the culture medium dose‐dependently decreased in presence of OPG, as did the level of activated caspase‐8 in osteoclasts. In addition, the expression of TRAIL by osteoclasts was not affected in the presence of OPG. Our findings suggest that OPG inhibits osteoclast apoptosis, at least in part, by binding and thus inhibiting endogenously produced TRAIL in human osteoclast cultures. TRAIL could be an autocrine factor for the regulation of osteoclast survival/apoptosis. J. Cell. Physiol. 216: 536–542, 2008. © 2008 Wiley‐Liss, Inc.
Effect of hydrolysis products and Mg2+, Mn2+ and Ca2+ ions on whey lactose hydrolysis and β‐galactosidase stability
Authors: Demirhan Elçin , Apar Dilek Kiliç , Özbek Belma
Published: March 2008

BACKGROUND: Enzyme inhibition is one of the constraints of reactions catalysed by enzymes, and information is required on the inhibition mechanisms that affect the process yield. Therefore the aim of the present study was to investigate the effect of hydrolysis products and ions on the hydrolysis of lactose recovered from whey and enzyme inactivation during the reaction. The experiments were carried out in 250 mL of 25 mmol L−1 phosphate buffer solution using β‐galactosidase from Kluyveromyces marxianus lactis in a batch reactor system.

RESULTS: The degree of lactose hydrolysis (%) and the residual enzyme activity (%) in the presence and absence of lactose over time were investigated versus hydrolysate amount, glucose and galactose concentrations and Mg2+, Mn2+ and Ca2+ ion concentrations. The hydrolysis degree decreased with the addition of all hydrolysis products, as enzyme inhibition occurred. The residual enzyme activity increased with the addition of hydrolysate and glucose but decreased with the addition of galactose. It was observed that Mn2+ and Mg2+ ions activated the enzyme. It was also found that the hydrolysis degree was not affected by the addition of Mn2+ ions. On the other hand, the hydrolysis degree decreased with the addition of Ca2+ ions, as the enzyme was inactivated.

CONCLUSION: Evaluation of the experimental data showed that both β‐galactosidase activity and lactose hydrolysis were affected by the addition of hydrolysis products and ions. Moreover, mathematical models proposed to predict the residual lactose concentration and residual enzyme activity were confirmed by the experimental results. Copyright © 2008 Society of Chemical Industry
Behaviour and mechanism of Zn(II) adsorption on Chinese loess at dilute slurry concentrations
Authors: Tang Xiaowu , Li Zhenze , Chen Yunmin
Published: March 2008

BACKGROUND: Zn(II) is commonly present in mining drainage in developing countries. Since loess is abundant and always located near mining sites in China, it would be useful to investigate the possibility and efficiency of using loess to remove Zn(II) from aqueous solution.

RESULTS: The Zn(II) adsorption capacity of Chinese loess was determined as 215.9 mg g−1. The adsorption followed pseudo‐second‐order kinetics and took place mainly by surface diffusion. Generally, higher initial pH and solute concentration resulted in higher % Zn(II) removal, while higher temperature and slurry concentration led to lower % Zn(II) removal. A thermodynamic study revealed that the adsorption process was exothermic, with the predicted enthalpy change ranging from −20.87 to −4.06 kJ mol−1. With the assistance of X‐ray photoelectron spectroscopy and X‐ray diffraction, the high adsorption capacity was ascribed to the growth of micro‐organisms and mineral constituents such as kaolinite and goethite.

CONCLUSION: Chinese loess proved effective for Zn(II) adsorption in this study. The optimal adsorption conditions included pH > 3.0, temperature ⩽15 °C and contact time ≈ 400 min. As an abundant natural soil in arid areas with very low population density, it would be appropriate to develop this material into a wastewater‐purifying agent. Copyright © 2008 Society of Chemical Industry
Peracetic acid pretreatment of sugarcane bagasse for enzymatic hydrolysis: a continued work
Authors: Zhao Xue‐Bing , Wang Lei , Liu De‐Hua
Published: March 2008

Previous work has shown that the enzymatic hydrolysis of sugarcane bagasse could be greatly enhanced by peracetic acid (PAA) pretreatment. There are several factors affecting the enzymatic digestibility of the biomass, including lignin and hemicelluloses content, cellulose crystallinity, acetyl group content, accessible surface area and so on. The objective of this work is to analyze the mechanism of the enhancement of enzymatic digestibility caused by PAA pretreatment. Delignification resulted in an increase of the surface area and reduction of the irreversible absorption of cellulase, which helped to increase the enzymatic digestibility. The Fourier transform infrared (FTIR) spectrum showed that the absorption peaks of aromatic skeletal vibrations were weakened or disappeared after PAA pretreatment. However, the infrared crystallization index (N.O'KI) was increased. X‐ray diffraction (XRD) analysis indicated that the crystallinity of PAA‐treated samples was increased owing to the partial removal of amorphous lignin and hemicelluloses and probable physical change of cellulose. The effect of acetyl group content on enzymatic digestibility is negligible compared with the degree of delignification and crystallinity. The results indicate that enhancement of enzymatic digestibility of sugarcane bagasse by PAA pretreatment is achieved mainly by delignification and an increase in the surface area and exposure of cellulose fibers. Copyright © 2008 Society of Chemical Industry
Dendrosomes as novel gene porters‐III
Authors: Sadeghizadeh Majid , Ranjbar Bijan , Damaghi Mehdi , Khaki Leila , Sarbolouki Mohammad N , Najafi Farhood , Parsaee Simak , Ziaee Abed‐Ali , Massumi Mohammad , Lubitz Werner , Kudela Paul , Paukner Susan , Karami Ali
Published: March 2008

BACKGROUND: It was previously reported that dendrosomes, i.e. neutral, biodegradable, covalent or self‐assembled, hyperbranched, spheroidal nano‐particles with a size ranging from 15 to 100 nm, provide a convenient and efficient means of gene delivery into various kinds of cells such as human hepatoma and kidney cells as well as animal models.

RESULTS: New studies via circular dichroism show that hydrophilic and amphipathic dendrosomes either do not affect the DNA structure or moderately transform it from B‐ to A‐conformation. Gene delivery into human liver, kidney, and endothelial cells as well as other animal cells like Bowes, U‐937, Raw, CCRF‐CEM, MOLT‐4, K562, Huh‐7 and VERO reveal that the genes are efficiently expressed and in comparison with other gene porters like Lipofectin or bacterial ghosts, do quite well. It is also shown that dendrosomes are able to deliver genes into cells like endothelials that are usually hard to transfect. Cell culture experiments as well as intraperitoneal/intradermal injections of dendrosomes into mice establish their nontoxicity (up to 2.5 mg kg−1 of animal weight in the latter case). Studies on immunization of BALB/c mice using conventional adjuvants such as aluminium phosphate, CpG motif and one of the dendrosomes, indicate that the latter leads to the mildest initial response development while exceeding them afterwards.

CONCLUSION: CD studies reveal that, owing to the neutrality of dendrosomes, formation of Den/DNA complexes is accompanied by slight structural modifications of DNA cell culture, and animal studies reveal that dendrosomes are inert, non‐toxic and highly efficient gene porters that perform at extremely low doses. In comparison with bacterial ghosts and some common porters, they are efficient in delivery of genes into animals and a variety of cells including those that are usually hard to transfect. Copyright © 2008 Society of Chemical Industry
Hydrothermal processing of rice husks: effects of severity on product distribution
Authors: Vegas Rodolfo , Kabel Mirjam , Schols Henk A. , Alonso J. L. , Parajó J.C.
Published: March 2008

BACKGROUND: Treatment in aqueous media (hydrothermal or autohydrolysis reactions) is an environmentally friendly technology for fractionating lignocellulosic materials. Rice husks were subjected to hydrothermal processing under a variety of operational conditions to cause the selective breakdown of xylan chains, in order to assess the effects of reaction severity on the distribution of reaction products.

RESULTS: The effects of severity (measured by the severity factor, R0) on the concentrations of the major autohydrolysis products (monosaccharides, xylo‐ and glucooligosaccharides, xylooligosaccharide substituents, acetic acid, acid‐soluble lignin and elemental nitrogen) were assessed. The interrelationship between the severity of treatment and molecular weight distribution was established by high‐performance size‐exclusion chromatography. Selected samples were subjected to refining treatments as ethyl acetate extraction and ion exchange for refining purposes, and the concentrates were assayed by high‐performance anion‐exchange chromatography and matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry.

CONCLUSIONS The protein equivalent of the products present in liquors accounted for 43 to 51% of the protein present in the raw rice husks. The concentrations of glucose (derived from starchy material) and arabinose (split from the xylan backbone) were fairly constant with severity. Even in treatments at low severity, high molecular weight compounds derived from xylan accounted for a limited part of the stoichiometric amount. Operating under harsh conditions, about 50% of the total xylan‐derived compounds corresponded to fractions with a degree of polymerization (DP) < 9. After refining, saccharides accounted for more than 90% of the non‐volatile components of the sample. The refined products showed a series of xylose oligomers up to about DP 13, and a series of acetylated xylose oligomers up to about DP 15. Copyright © 2008 Society of Chemical Industry
Kinetics of synthesis of butyl butyrate by esterification and transesterification in supercritical carbon dioxide
Authors: Varma Mahesh N. , Madras Giridhar
Published: March 2008

BACKGROUND: The synthesis of butyl butyrate (used as a pineapple flavor) by green chemistry is of immense importance to the food industry. This study investigated the enzymatic esterification of butanol and butyric acid to butyl butyrate and transesterification of ethyl butyrate to butyl butyrate in supercritical carbon dioxide (ScCO2) with a lipase, Novozym 435.

RESULTS: The effect of various parameters, such as temperature and enzyme, loading was investigated. The initial rate increased sharply up to 3% (w/w) and 7% (w/w) of enzyme loading for esterification and transesterification, respectively while further addition of enzyme did not increase the initial rate significantly. The optimum temperature for the reaction was between 45–50 °C. Because lipases can catalyze both esterification and hydrolysis, a complete kinetic model accounting for both reactions was developed and used to determine the kinetic parameters.

CONCLUSION: Butyl butyrate was successfully synthesized in supercritical carbon dioxide in the presence of a lipase. The kinetic parameters for esterification, hydrolysis and transesterification were determined using the Ping‐Pong Bi‐Bi mechanism with substrate inhibition and represented by the Lineweaver and Burk plot. Copyright © 2008 Society of Chemical Industry
Separation and concentration of bilberry impact aroma compound from dilute model solution by pervaporation
Authors: García Verónica , Diban Nazely , Gorri Daniel , Keiski Riitta , Urtiaga Ane , Ortiz Inmaculada
Published: March 2008

BACKGROUND: In the present work, the flavor compounds of natural juice of bilberries were qualitatively analyzed by GC‐MS, leading to the identification of trans‐Hex‐2‐en‐1‐ol as one of the major ‘impact aroma’ compounds of this fruit. The pervaporation of trans‐Hex‐2‐en‐1‐ol from diluted aqueous solutions was studied using commercial polydimethylsiloxane (PDMS) capillary membranes. The influences of solvent composition (water/ethanol mixtures), initial concentration of the aroma compound, flow rate and temperature of the feed were studied.

RESULTS: High selectivity of the PDMS membrane towards the aroma compound was obtained, leading to enrichment factors in the range 100 < β < 200. Mass transfer resistance was found to be located in the pervaporation membrane. Experimental data showed a linear dependency of the permeation flux of trans‐Hex‐2‐en‐1‐ol on the differences in partial pressures of the compound across the pervaporation membrane. The permeability coefficient of the PDMS membrane to the transport of trans‐Hex‐2‐en‐1‐ol was calculated as Pm, Hex(50 °C) = 7.62 × 10−11 mol m−1 s−1 Pa−1.

CONCLUSION: The membrane used was found to be very selective toward trans‐Hex‐2‐en‐1‐ol. A model based on the solution‐diffusion mechanism was applied. The mass transfer parameters needed for the design of a pervaporation process for aroma compound recovery were obtained. Copyright © 2008 Society of Chemical Industry
Development through integration? EU aid reform and the evolution of Mediterranean aid policy
Authors: Holden Patrick
Published: March 2008

The recipient states for Mediterranean aid are the middle‐income Arab countries of the Mediterranean littoral. Due to the region's importance for Europe there is a comprehensive EU strategy for the region and this has shaped Mediterranean aid policy more than the EU's generic aid policy reforms, although these have also had an impact. The EU's approach to developing these countries is to instigate liberal economic reform and integrate them economically with Europe. This takes the form of a regional free trade area and bilateral integration with the EU's single market. Mediterranean aid from 2001 to 2007 has been targeted at supporting and enabling reform in key sectors. A crude form of allocative (rewards‐based) conditionality has been applied. Assistance is thus more focused and coherent with EU policy than before. The Country Strategy Paper format and the organisational reforms of the aid programme facilitated this, but the political importance given to the Mediterranean area is the major reason. In any case, the broader reform and development strategy is not a success, as there is little sign that partial integration with Europe will enable economic development. While there is a new, post‐2006, aid instrument for the region this is not fundamentally different to its predecessor. Copyright © 2008 John Wiley & Sons, Ltd.
Loss of benzene to generate an enolate anion by a site‐specific double‐hydrogen transfer during CID fragmentation of o‐alkyl ethers of ortho‐hydroxybenzoic acids
Authors: Attygalle Athula B. , Bialecki Jason B. , Nishshanka Upul , Weisbecker Carl S. , Ruzicka Josef
Published: March 2008

Collision‐induced dissociation of anions derived from ortho‐alkyloxybenzoic acids provides a facile way of producing gaseous enolate anions. The alkyloxyphenyl anion produced after an initial loss of CO2 undergoes elimination of a benzene molecule by a double‐hydrogen transfer mechanism, unique to the ortho isomer, to form an enolate anion. Deuterium labeling studies confirmed that the two hydrogen atoms transferred in the benzene loss originate from positions 1 and 2 of the alkyl chain. An initial transfer of a hydrogen atom from the C‐1 position forms a phenyl anion and a carbonyl compound, both of which remain closely associated as an ion/neutral complex. The complex breaks either directly to give the phenyl anion by eliminating the neutral carbonyl compound, or to form an enolate anion by transferring a hydrogen atom from the C‐2 position and eliminating a benzene molecule in the process. The pronounced primary kinetic isotope effect observed when a deuterium atom is transferred from the C‐1 position, compared to the weak effect seen for the transfer from the C‐2 position, indicates that the first transfer is the rate determining step. Quantum mechanical calculations showed that the neutral loss of benzene is a thermodynamically favorable process. Under the conditions used, only the spectra from ortho isomers showed peaks at m/z 77 for the phenyl anion and m/z 93 for the phenoxyl anion, in addition to that for the ortho‐specific enolate anion. Under high collision energy, the ortho isomers also produce a peak at m/z 137 for an alkene loss. The spectra of meta and para compounds show a peak at m/z 92 for the distonic anion produced by the homolysis of the OC bond. Moreover, a small peak at m/z 136 for a distonic anion originating from an alkyl radical loss allows the differentiation of para compounds from meta isomers. Copyright © 2008 John Wiley & Sons, Ltd.
Matrix‐free laser desorption/ionization of ions landed on plasma‐treated metal surfaces
Authors: Volný Michael , Sadílek Martin , Jackson Karl E. , Diener Matthew , Elam W. Tim , Tureček František
Published: March 2008

We report new experiments in which laser desorption/ionization time‐of‐flight mass spectrometry (LDI‐TOF‐MS) was applied to detection and characterization of gramicidin S and IgG pentapeptide (DSDPR) that were reactively landed on plasma‐treated stainless steel surfaces. The distributions of [M + H]+, [M + Na]+ and [M + K]+ ion species in LDI‐TOF for gramicidin S and IgG pentapeptide (DSDPR) were found to be markedly different from those in conventional MALDI‐TOF spectra of the same samples. LDI‐TOF mass spectra showed a strong preference for [M + K]+ adducts even in the presence of a large excess of sodium cations, or following surface treatment with trifluoroacetic acid. Alkali metal cations (K+ and Cs+) can be exchanged in reactively landed peptide samples to provide the corresponding cationized peptide ions by LDI. Multiple charged trypsin cations were reactively landed into a layer of 2‐(4‐hydroxyphenylazo)benzoic acid and ionized by LDI. The ionization mechanisms for LDI of surface‐deposited peptides are briefly discussed. Copyright © 2008 John Wiley & Sons, Ltd.
Changes in the large‐scale features associated with the Indian summer monsoon in the recent decades
Authors: Yadav R. K.
Published: March 2008

The inter‐annual variability of the Indian summer monsoon rainfall (ISMR) has been examined in association with the variability of surface temperature, the mean sea level pressure (MSLP), the tropospheric geopotential height, and wind patterns over the globe to study the changes in the large‐scale features associated with Indian summer monsoon (ISM) in the recent decades. The data for the study have been considered from 1949–2005 (for a period of 57 years). It has been found that, during the recent decades, the El Nino‐Southern Oscillation (ENSO) relationship over ISMR has weakened while the northwest (NW) of North Atlantic sea surface temperature (SST) relationship has increased. A physical mechanism for the relationship of North Atlantic SST with ISMR is proposed, by which during the excess years of ISMR, the SST over NW of North Atlantic is above normal. The rise in SST is the consequence of intensification and a cell‐type shaped Azores high with isobars parallel to the east coast of North America, which drives a subtropical oceanic gyre (Gulf stream) transporting equatorial warm water NW of North Atlantic. The Azores high act as a source of downstream Rossby wave train over Eurasian region having barotropic structure consisting of a successive pressure trough and ridge. The Rossby wave may be associated with intensifying the low surface pressure anomaly over the Iranian landmass, which intensify the monsoon current over the Indian region. Copyright © 2008 Royal Meteorological Society
Nanocomposites based on polyolefins and functional thermoplastic materials
Authors: Ciardelli Francesco , Coiai Serena , Passaglia Elisa , Pucci Andrea , Ruggeri Giacomo
Published: March 2008

Polyolefins are today the most used thermoplastic materials thanks to the high technology and sustainability of the polymerization process, their excellent thermomechanical properties and their good environmental compatibility, including easy recycling. In the last few decades much effort has been devoted worldwide to extend the applications of polyolefins by conferring on them new properties through mixing and blending with different materials. In this latter context, nanocomposites have recently offered new exciting possibilities. This has been made possible on the basis of the improvement of polyolefin functionalization processes with the availability of several olefin homo‐ and copolymers bearing a small (generally less than 1 mol%) amount of backbone grafted polar groups. These are indeed adequate to endow favourable interface interactions with polar macromolecules and inorganic compounds, leading first to compatible blends and then to microcomposites. The successful use of nanostructured dispersed materials has opened, on a similar basis, the way to nanocomposites as described in this review. This review provides a broad and updated description of the synthetic routes to nanostructured biphase materials having the typical structural properties of polyolefins (continuous matrix) but showing enhanced thermomechanical properties, thermostability, lower flammability, lower gas permeability and electrical and optical properties, thanks to the presence of an extended interphase interaction with very different nanodispersed species. Copyright © 2008 Society of Chemical Industry
A novel photo‐responsive organogel based on azobenzene
Authors: Zhou Yifeng , Xu Miao , Wu Junchen , Yi Tao , Han Jiantao , Xiao Shuzhang , Li Fuyou , Huang Chunhui
Published: March 2008

A novel triarmed cis‐1, 3, 5‐cyclohexanetricarboxamides gelator, functionalized by three azobenzene moieties grafted with three long alkyl chains, was designed and synthesized. The gelator can gel most of the organic solvents in low concentration. The morphologies of the xerogels show one‐dimensional aggregated bundles or helical fibres. The azobenzene groups in the gel state form H‐type aggregation and perform expected trans–cis photoisomerization with a gel to sol phase transition upon irradiation of UV light. The main driving force for gelation is intermolecular hydrogen bonding between amides and π–π interaction of azobenzene moieties. Copyright © 2008 John Wiley & Sons, Ltd.