bluuebunny/crossref_metadata_2025 huggingface dataset:
Feasibility of subsurface drainage for salinity control in the Trans‐Gangetic region of India
Authors: Datta K. K. , de Jong C. , Singh O. P.
Published: October 2002

The sustainability of irrigated agriculture in India is threatened by waterlogging, soil salinity and alkalinity. To reverse declining agricultural productivity, a combination of surface and subsurface drainage, supplemented by improved irrigation management, has been identified as the most appropriate strategy. But drainage for salinity control is costly. Therefore, the benefits in terms of sustained agricultural production must be thoroughly investigated to establish its techno‐economic feasibility. The present study attempts to do this by analysing: (i) the cost of installing subsurface drainage, (ii) the direct on‐farm benefits of subsurface drainage, and (iii) the financial feasibility of subsurface drainage.

Haryana State was selected as the site of the study. The study shows that, after the installation of drainage, land utilization intensified as a sizeable area of formerly fallow land was brought under cultivation. It also shows that the cropping pattern changed in favour of more remunerative crops and that crop yields increased. This is an indication of the immediate gain from drainage, which helps to increase land productivity, gainful employment of the farmers and, hence, farm income. Recently (1997–98), mechanically installed large‐scale drainage development in the framework of the Indo‐Dutch Haryana Operational Pilot Project (HOPP) also supported the above findings. Given a sustainable solution for the disposal of the drainage effluent, the financial feasibility of drainage in waterlogged and saline areas looks favourable, provided that sufficient water is available for leaching and irrigation. Copyright © 2002 John Wiley & Sons, Ltd.
Individual and combined effect of waterlogging and salinity on crop yields in the Indus basin
Authors: Kahlown Muhammad Akram , Azam Muhammad
Published: October 2002

Waterlogging and salinity are the major threats to the sustainability of irrigated agriculture in Pakistan. About 50% of the Culturable Command Area (CCA) in the Fordwah Eastern Sadiqia South (FESS) is affected by waterlogging and 12% by surface and profile salinity. A sample of 26 watercourses was selected in the project area to evaluate the individual and combined impacts of waterlogging and salinity on the yields of cotton, wheat, sugarcane and rice. The crop yields were measured separately for waterlogged fields and those affected with salinity and waterlogging simultaneously. The extent of yield loss as result of a rise in the water table from 1–2 m to less than 1 m was 27 and 33% for wheat and sugarcane crops, whereas it was 7 and 6% in the case of a drop of the water table to more than 2 m. For cotton, a rising water table from 2–3 m to 1–2 m and less than 1 m gave a yield decrease of about 11 and 60% respectively. The rice crop preferred waterlogging, and in contrast to other crops, gave about 7% less yield with a lowering of the water table from less than 1 m to 1–2 m. The wheat and sugarcane yields had decreasing trends with salinity in excess of 4 dS m−1 and had complete failures with salinity greater than 12 dS m−1 at water table depths of less than 1, 1–2 and 2–3 m. The cotton crop demonstrated relatively higher salinity tolerance under a water table deeper than 1 m. However, this crop could not survive at salinity levels in excess of 12 dS m−1 at water table depth of less than 1 m. The rice crop was a complete failure at salinity level of greater than 12 dS m−1 under water table depths of less than 1 and 1–2 m. The combined impact of waterlogging and salinity was more harmful to crop yields when compared with the individual effects of waterlogging. The combined analysis of waterlogging and salinity on crop yields provide a good sensitivity of the salinity‐yield relationships and indicated the importance of subsurface drainage. Copyright © 2002 John Wiley & Sons, Ltd.
Egg coats of the rock shrimp Rhynchocinetes typus: ultrastructural characterization and their function during fertilization
Authors: Palomino Jaime , Moreno Ricardo D. , Bustamante Eva , Messen Lucy , Dupré Enrique , Barros Claudio
Published: October 2002

The aim of the present work was to characterize structurally and ultrastructurally the egg coats of the rock shrimp, Rhynchocinetes typus, and to describe their functional roles during fertilization. Oocytes fixed directly from the ovary, have a total diameter of 549 µm and are covered by a 10‐µm‐thick transparent envelope. Electron microscope sections (dehydrated) of the egg envelope revealed an electron‐dense external coat of 0.4 µm covered by filamentous processes, and a granular inner coat of 4‐µm thickness. Oocytes placed for 5 min in seawater had a significantly larger diameter (573 µm), because of the increase in the thickness of the egg coats (32 µm) and the formation of a 16‐µm perivitelline space. The diameter of the egg proper was reduced by the same extent as the size of the perivitelline space. All these changes were associated to the loss of the egg fertilizability. SDS‐PAGE of isolated and solubilized egg coats with 20% β‐mercaptoethanol or 25 mM dithiothreitol (DTT) showed bands between 58 and 105 kDa and between 44 and 103 kDa, respectively. During normal fertilization, the sperm undergoes a drastic change in shape after first contact with the egg. We observed a similar change when solubilized egg coats were placed with vas deferens sperms. When the solubilized egg coat proteins were ultrafiltrated with a membrane of 10,000 MWCO (pore size) and then assayed for their effect on fertilization, an inhibitory effect of 30%, 41%, and 59% was found when oocytes were incubated with spermatozoa pre‐treated with 30, 60, and 120 µg/ml of proteins solubilized with β‐mercaptoethanol. A similar inhibitory effect was found when egg coat proteins solubilized with 25 mM DTT were used. Our results suggest that, in the shrimp, the egg coats play an active role during the morphological changes of the sperm during their passage through them. J. Exp. Zool. 293:632–640, 2002. © 2002 Wiley‐Liss, Inc.
Variation in plasma lipids during the reproductive cycle of male and female desert tortoises, Gopherus agassizii
Authors: Lance Valentine A. , Place Allen R. , Grumbles Janice S. , Rostal David C.
Published: October 2002

Plasma triacylglycerol, phospholipid, cholesterol, cholesterol esters, fatty acids, and total lipids were measured in 30 female and 20 male desert tortoises (Gopherus agassizii) during the annual reproductive cycle in the eastern Mojave desert, Nevada. Blood samples were collected at monthly intervals from April to October. All lipid fractions, with the exception of free fatty acids, were significantly higher in female plasma than in male plasma in all months of the year. In contrast, free fatty acids were higher in male plasma than in female plasma in all months. The seasonal pattern in estradiol secretion mirrored that of triacylglycerol, phospholipid, cholesterol, and total lipid, all of which showed a significant correlation with the hormone. Estradiol and the vitellogenesis‐associated lipids were all significantly higher in August, September, October, and April than in June. The seasonal variation in cholesterol ester levels in females did not correlate with any of the reproductive events and did not appear to be involved in yolk precursor formation. Total lipid in males showed a negative correlation with testosterone and spermatogenesis. Individual fatty acids in the June and August samples (at the highest and lowest estradiol levels) were compared in male and female plasma. The percent of C18:3n3, C18:2n6, C18:1n9, C20:5n3, and C22:5 were significantly higher in the June female plasma sample than in the August sample. Docosahexanoic (C22:6n3) acid was barely detectable in female plasma in either month. J. Exp. Zool. 293:703–711, 2002. © 2002 Wiley‐Liss, Inc.
Juvenoid hormone methyl farnesoate is a sex determinant in the crustacean Daphnia magna
Authors: Olmstead Allen W. , Leblanc Gerald A.
Published: October 2002

Daphnids (Daphnia magna) utilize cyclic parthenogenesis as a reproductive strategy. During periods of abundant resources, these organisms reproduce asexually. In response to environmental cues that signal the onset of environmental adversity, daphnids produce males and reproduce sexually. The environmental cues that stimulate the sexual reproductive phase are well known; however, the endocrine signals that transduce these environmental cues remain unknown. The present study was undertaken to test the hypothesis that the crustacean juvenoid hormone, methyl farnesoate, is a male sex determinant in this species. Continuous exposure to aqueous concentrations of methyl farnesoate greater than approximately 30 nM stimulated a concentration‐dependent production of male‐containing broods of organisms. Short‐term exposures to methyl farnesoate during periods of egg and embryo maturation revealed that male sex determination occurred during a specific 12‐hour period of ovarian egg development. Exposure of eggs to 400 nM methyl farnesoate during this sensitive developmental period resulted in the production of all‐male broods of offspring, while exposure to concentrations as low as 52 nM produced mixed broods of males and females. This active concentration range of methyl farnesoate is consistent with levels measured in the hemolymph of some decapod crustaceans. These results demonstrate that methyl farnesoate is capable of programming daphnid embryos to develop into males and is likely the endocrine factor responsible for initiating the sexual reproductive phase in these organisms. J. Exp. Zool. 736–739, 2002. © 2002 Wiley‐Liss, Inc.
Specific binding of the endocytosis tracer horseradish peroxidase to intestinal fatty acid‐binding protein (I‐FABP) in apical membranes of carp enterocytes
Authors: Concha Margarita I. , Santander Cristián , Villanueva Julieta , Amthauer Rodolfo
Published: October 2002

In a previous study we had demonstrated that a 15‐kDa protein present in carp intestinal brush‐border membrane vesicles (BBMV) was able to bind the endocytosis tracer horseradish peroxidase (HRP) with high specificity. Here we show that this protein corresponds to a peripheral membrane protein, identified by partial amino acid sequence analysis as the intestinal fatty acid‐binding protein (I‐FABP), a member of the small cytosolic fatty acid binding protein family (FABPs). The presence of I‐FABP and its HRP‐binding activity was demonstrated both in the cytosolic and membrane‐associated fractions of intestinal mucosa by Western and ligand blot analyses, respectively. Also, both fractions displayed significant capacity to bind [3H]palmitic acid, a known ligand for I‐FABP. Immunohistochemical analysis showed that I‐FABP localizes both in the cytosol and in the brush‐border membranes of epithelial cells. Taken together the unusual extra‐cellular localization of I‐FABP as well as its ability to interact with HRP suggests a novel function for this protein in the intestinal mucosa. J. Exp. Zool. 293:541–550, 2002. © 2002 Wiley‐Liss, Inc.
Dynamics of vitellogenin mRNA expression and changes in hemolymph vitellogenin levels during ovarian maturation in the giant freshwater prawn Macrobrachium rosenbergii
Authors: Jayasankar Vidya , Tsutsui Naoaki , Jasmani Safiah , Saido‐Sakanaka Hisako , Yang Wei‐Jun , Okuno Atsuro , Hien Tran Thi Thanh , Aida Katsumi , Wilder Marcy N.
Published: October 2002

The dynamics of vitellogenin mRNA expression during ovarian maturation in Macrobrachium rosenbergii were examined by measuring hemolymph vitellogenin (Vg) levels and Vg mRNA expression in the hepatopancreas and ovary at differing reproductive stages in both intact and eyestalk ablated animals. Vg mRNA was quantified using real‐time RT‐PCR and hemolymph Vg was measured by enzyme immunoassay. In intact animals, Vg mRNA levels in the hepatopancreas and hemolymph Vg levels showed a gradual increase during the molt cycle concomitant with increasing gonadosomatic index (GSI), with Vg levels decreasing prior to ecdysis although GSI continued to increase. Eyestalk ablation was seen to accelerate Vg synthesis as well as ovarian maturation, although it did not alter the overall pattern of Vg expression. Vg mRNA expression was negligible in the ovary of both intact and eyestalk ablated animals, confirming that the hepatopancreas is the principal site of Vg synthesis in M. rosenbergii with the ovary being only a minor contributor. This study has shown that Vg synthesis is correlated to ovarian maturation and the molt cycle in M. rosenbergii. J. Exp. Zool. 293:675–682, 2002. © 2002 Wiley‐Liss, Inc.
Effects of altered photoperiod and temperature, serotonin‐affecting drugs, and melatonin on brain tyrosine hydroxylase activity in female catfish, Heteropneustes fossilis: A study correlating ovarian activity changes
Authors: Chaube R. , Joy K.P.
Published: October 2002

Exposure of female catfish, Heteropneustes fossilis to 30‐day regimes of long photoperiod (16L), elevated temperature (28 ± 2°C), or a combination of both stimulated brain tyrosine hydroxylase (TH) activity significantly over that of control fish held in natural conditions in gonad resting (10.5L:13.5D, 10 ± 2°C) and preparatory (12.5L:11.5D,18 ± 2°C) phases. The response was high in the combination group in both phases. The increase in TH activity was higher in forebrain regions (telencephalon and hypothalamus) than medulla oblongata. Exposure of the fish to short photoperiod (8L:16D) and total darkness decreased the enzyme activity significantly in both resting and preparatory phases regardless of the temperature. The inhibition was high in fish held under total darkness. Gonadosomatic index (GSI) was significantly elevated in long photoperiod and high temperature groups, alone or in combination, and decreased significantly in short photoperiod (only in preparatory phase) and total darkness groups. Administration of the serotonin precursor 5‐hydroxytryptophan (5‐HTP; 5mg/100g body weight [BW], three daily intraperitoneal [i.p.] injections prior to sacrificing) stimulated TH activity in fish held under long and normal photoperiods in both phases. Three daily injections of the serotonin blocker parachlorophenylalanine (p‐CPA; 10mg/100g BW) and melatonin (75 µg/100g BW) prior to sacrificing inhibited brain TH activity significantly in both phases. GSI was significantly stimulated by 5‐HTP, and inhibited by both p‐CPA and melatonin injections. Changes in TH activity and GSI can be correlated and explained on the basis of previous reports on changes in catecholamine activity that modulates gonadotropin secretion in the catfish. Further, the photoperiod and temperature‐induced changes in TH activity may be modulated by alterations in serotonergic activity. J. Exp. Zool. 293:585–593, 2002. © 2002 Wiley‐Liss, Inc.
Radiosynthesis of [123I]N‐(3‐iodoprop‐(2E)‐enyl)‐2α‐(imino‐methyl)‐3β‐(3′,4′‐dichlorophenyl) nortropane as a potential SPET tracer for dopamine transporter
Authors: Yu Meixiang , Airaksinen Anu J. , Gee Antony D. , Lötjönen Simo , Kuikka Jyrki T. , Vepsäläinen Jouko J. , Hiltunen Jukka , Bergström Kim A.
Published: October 2002

The radiosynthesis of a novel tropane derivative [123I]KUC‐25019, [[123I];N‐(3‐iodoprop‐(2E)‐enyl)‐2α‐(imino‐methyl)‐3β‐(3′,4′‐dichlorophenyl)nortropane], a potential inhibitor of the dopamine transporter is reported. The synthetic routes include the preparation of standard reference, the stannyl precursor and the 123I‐labeling synthesis. The no‐carrier‐added 123I‐labeling has about 20% yield, the specific activity of [123I]KUC‐25019 is > 107 GBq/µmol and the radiochemical purity of [123I] KUC‐25019 is >95%. Copyright © 2002 John Wiley & Sons, Ltd.
New preparation of [123I]PE2I: investigation of the oxidation and purification steps
Authors: Berthommier E. , Loc'h C. , Chalon S. , Olivier C. , Emond P. , Dao Boulanger H. , Lelait M.A. , Mauclaire L.
Published: October 2002

In order to simplify preparation of [123I]PE2I, iodogen and hydrogen peroxide were examined as oxidants for the preparation of radioiodinated PE2I, e.g. (E)‐N‐(3‐iodoprop‐2‐enyl)‐2β‐carbomethoxy‐3β‐(4′‐tolyl) nortropane). Among the oxidizing compounds assayed, iodogen appears to afford the best results for this purpose (high radiochemical yield, high chemical purity and a reasonable reaction time). A simplified and efficient method is described here for the preparation of [123I]PE2I based on the exchange of a 123I tributyl tin analogue in oxidative conditions followed by purification by solid phase extraction (SPE). Using this method, [123I]PE2I was obtained with a radio‐pharmaceutical yield over 60%, with chemical and radiochemical purities higher than 95% without the addition of a carrier (Na127I) (2G Bq/nmol) or with a specific activity adjusted to 85–90 MBq/nmol in the presence of the carrier. Copyright © 2002 John Wiley & Sons, Ltd.
Nerve growth factor and enhancement of proliferation, invasion, and tumorigenicity of pancreatic cancer cells
Authors: Zhu Zhaowen , Kleeff Jörg , Kayed Hany , Wang Li , Korc Murray , Büchler Markus W. , Friess Helmut
Published: October 2002

Nerve growth factor (NGF) exerts both stimulatory and inhibitory effects on neuronal and certain non‐neuronal tumors. In pancreatic cancer NGF is overexpressed, and this overexpression is associated with increased perineural invasion. NGF has the potential to stimulate the growth of some pancreatic cancer cell lines, and this effect is mediated by the phosphorylation of tyrosine kinase receptor A and mitogen‐activated protein kinase activation; it is dependent on the expression levels of tyrosine kinase receptor A and p75 receptors. To determine whether cancer cell–derived NGF can participate in the regulation of pancreatic cancer cell proliferation, PANC‐1 human pancreatic cancer cells were stably transfected with a full‐length human β‐NGF expression vector. In vitro and in vivo growth characteristics were analyzed by proliferation assays and invasion assays and in a nude mouse tumor model. Stable transfection of NGF in PANC‐1 cells resulted in enhanced anchorage‐dependent growth, with a decrease in doubling times of up to 50%, and in an approximately twofold increase in anchorage‐independent cell growth and cell invasion. Furthermore, stably transfected PANC‐1 cells showed enhanced tumorigenicity in nude mice. These results suggest that NGF has the capacity to act in a paracrine and/or an autocrine manner in pancreatic cancer and that it enhances cancer cell growth and invasion in vivo, thereby contributing to the aggressiveness and poor prognosis of this disease. © 2002 Wiley‐Liss, Inc.
Contributions of mitogen‐activated protein kinase and nuclear factor kappa B to N‐(4‐hydroxyphenyl)retinamide–induced apoptosis in prostate cancer cells
Authors: Shimada Keiji , Nakamura Mitsutoshi , Ishida Eiwa , Kishi Munehiro , Yonehara Shin , Konishi Noboru
Published: October 2002

The synthetic retinoid N‐(4‐hydroxyphenyl)retinamide (4‐HPR) has been shown to induce apoptosis in various types of tumors, including prostate cancer. We sought to examine the key mechanisms affecting the resistance to 4‐HPR–induced apoptosis in three human prostate cancer cell lines, PC‐3, DU145, and LNCaP. Concentrations of more than 40 μM 4‐HPR produced apoptosis to almost the same extent in all cell lines; however, only the LNCaP line remained highly sensitive to concentrations less than 10 μM. These differing sensitivities at low concentrations correlated well with the level of constitutive activation of nuclear factor kappa B (NFκB) in the individual cell lines. We found that NFκB activation inhibited c‐jun NH2‐terminal kinase and caspase 3 activation induced by 4‐HPR and that NFκB inhibition by the I kappa B alpha phosphorylation inhibitor compound Bay 117082 resulted in increasing sensitization of both PC‐3 and DU145 lines to apoptosis induced by 4‐HPR at low concentrations. Furthermore, we found that inhibition of extracellular signal–regulated kinase (ERK) enhanced the suppression of NFκB by 4‐HPR and also resulted in sensitization to apoptosis in the DU145 cell line, in which ERK is activated constitutively. It thus appears that mitogen‐activated protein kinase associated with the activity of NFκB plays an important role in the degree of resistance to 4‐HPR‐induced apoptosis in human prostate cancer cells. © 2002 Wiley‐Liss, Inc.
Analgesic use for postoperative pain: differences arise when comparing departments of surgery
Authors: Soler‐Company Enrique , Baños Josep‐E. , Faus‐Soler Teresa , Morales‐Olivas Francisco , Montaner‐Abasolo Carmen
Published: October 2002

Purpose

The goal of the study is to analyse whether the analgesic therapy of postoperative pain during the first 2 days after surgery differs among the different surgical departments.

Methods

Patients were randomly chosen from among all those who underwent elective surgery. Characteristics of analgesic treatment (drug, dosage, schedule) and pain intensity were determined at the postoperative anaesthetic care unit and in the first and second postoperative days on the ward. All comparisons were carried out by surgical departments.

Results

Six hundred and twenty‐three patients from six surgical departments were studied. Analgesic treatment orders varied greatly among the different departments, and these differences were statistically significant regarding number of drugs, type of drugs, analgesic schedule, and completeness of medical orders. Some differences were also observed regarding drug dosage. Patients from gynaecology and obstetrics, traumatology and orthopaedics and general surgery reported the most severe pain.

Conclusions

The treatment of postoperative pain differs among the surgical departments, especially regarding analgesic schedules and completeness of analgesic orders. Analgesic therapy may often be based more on customary habits than on the patients' pain intensity. Copyright © 2002 John Wiley & Sons, Ltd.
Synthesis and properties of biodegradable chitin‐graft‐poly(L‐lactide) copolymers
Authors: Kim Ji Young , Ha Chang Sik , Jo Nam Ju
Published: October 2002

In this study, novel biodegradable polymers were synthesized by ring opening polymerization (ROP) of L‐lactide on chitin in an N,N‐dimethyl acetamide (DMAc)/lithium chloride (LiCl) solvent system, and chitin was used as macroinitiator to afford new materials. Lithium chloride (LiCl) was used as catalyst. The synthesized copolymers [chitin‐graft‐poly(L‐lactide) (PLLA)] were characterized by Fourier transform infrared (FTIR) spectroscopy to confirm the newly formed ester bond. From the FTIR spectra, the peak intensity of ester bond in the chitin‐graft‐PLLA copolymers increased in comparison to that of L‐lactide monomer. Therefore, it was confirmed that PLLA was successfully grafted on to chitin. Also, cross polarization–magic angle spinning (CP‐MAS), 13C solid state NMR spectroscopy and differential scanning calorimetry were used to characterize novel chitin‐graft‐PLLA copolymers.

© 2002 Society of Chemical Industry
Supramolecular polymer chemistry—scope and perspectives
Authors: Lehn Jean‐Marie
Published: October 2002

The connection of molecular monomers through non‐covalent intermolecular interactions leads to the formation of polymolecular entities defining a supramolecular polymer chemistry. The basic features of this field are presented and illustrated by some selected results. Thus, the molecular recognition directed association between monomers bearing complementary hydrogen bonding groups leads to linear supramolecular polymers and liquid crystals. Also, rigid rod, two‐dimensional, metal coordination‐based, side‐chain and cross‐linked supramolecular polymeric entities may be envisaged and several types have been generated. Like supramolecular materials in general, supramolecular polymers are reversible, constitutionally dynamic materials, capable of modifying their constitution by exchanging, recombining, incorporating components. They may present a variety of novel properties and behave as adaptive materials.

© 2002 Society of Chemical Industry
Morphology and enzymatic degradation of poly(ϵ‐caprolactone) single crystals: does a polymer single crystal consist of micro‐crystals?
Authors: Iwata Tadahisa , Doi Yoshiharu
Published: October 2002

Solution‐grown lamellar single crystals of poly(ϵ‐caprolactone) (PCL) were prepared from a dilute solution of n‐hexanol by the isothermal crystallization condition or the self‐seeding method. Hexagonal‐shaped lamellar crystals with and without spiral growth were obtained, and the crystals produced well‐resolved electron diffraction diagrams. The chain‐packing structure and morphological complexity in lamellar crystals were investigated by bright‐field and dark‐field diffraction contrast methods of transmission electron microscopy. Based on both diffraction contrast images, it was revealed that both tightly and loosely chain‐packing regions exist in one lamellar crystal. Thus, it was emphasized that PCL solution‐grown lamellar single crystals consist of micro‐crystals with nano‐order size for the crystalline core region. Lipase type XIII from Pseudomonas sp was used for the enzymatic degradation of the PCL lamellar crystals. Enzymatic degradation progressed perpendicularly from the crystal lateral sides, without decrease of the molecular weight and lamellar thickness, yielding notched‐shaped morphologies to the crystals. These results further indicate that PCL lamellar crystals consist of nano‐order micro‐crystals, and that enzyme hydrolyzes the loosely chain‐packing regions between the tightly chain‐packing regions (micro‐crystal regions).

© 2002 Society of Chemical Industry
Effect of photo‐initiators on melt degradation of polypropylene and starch‐filled polymer
Authors: Bagheri Rouhallah , Naimian Faranak
Published: October 2002

Six series of the processed polypropylene (pp) samples containing 0.25–1 wt% photo‐initiators (PIs, four aromatic carbonyl, two ferric compounds) and also a series of 6 wt% corn‐starch‐filled pp containing 0.5 wt% of each PI, were prepared using a mixer in a closed system at 180 °C for 5 min. The melt flow index (MFI) and apparent viscosity measurments of the processed pp–PI samples showed a large increase in MFI/or decrease in apparent viscosity at 0.25 wt% of the PIs. Further increase in the amounts of PIs led these properties to reach a constant value at 0.5 wt% of the PIs. The presence of corn starch in the samples corresponded to a much lower increase in the MFI or decrease in the apparent viscosity. Ferric stearate and Irgacure 184 amoung the PIs showed the highest and lowest melt degradation effects, respectively. Carbonyl measurments of all the film samples showed good correlations between chemical changes in the pp structure and variations in the flow properties during processing. UV absorption of the films also evidenced the presence of the aromatic carbonyl PIs in the pp matrix after melt processing.

© 2002 Society of Chemical Industry
Ethylene polymerization by iron complexes with symmetrical and unsymmetrical ligands
Authors: Ma Zhi , Sun Wen‐Hua , Li Zi‐Long , Shao Chang‐Xing , Hu You‐Liang , Li Xiu‐Hua
Published: October 2002

A series of penta‐coordinated iron complexes with 2,6‐bis(imino)pyridine ligands were prepared and used in ethylene polymerization or oligomerization with methylaluminoxane as (MAO) co‐catalyst. The activity of the complexes depends strongly on the steric and electronic effects of the ligands, in which the electronic conjugated system plays an important role. N,N′‐Bis(α,α‐diphenyl) methyl 2,6‐bis(imino)pyridine iron complex (1) could not activate ethylene, N,N′‐difluorenyl‐2,6‐bis(imino)pyridine iron complex (2) exhibited high activity for ethylene oligomerization, whilst N,N′‐diaryl 2,6‐bis(imino)pyridine iron complexes (3–6) performed ethylene polymerization. The results are collected and briefly discussed.

© 2002 Society of Chemical Industry
Tissue engineering matrixes by emulsion templating
Authors: Busby Wendy , Cameron Neil R , Jahoda Colin A B
Published: October 2002

Foams containing poly(lactic acid) (PLA) have been prepared from the corresponding macromonomers using high internal phase emulsions (HIPEs) as templates to create the porous structure. The resulting PolyHIPE foams have been investigated by scanning electron microscopy and the influence of diluent type, either reactive (styrene or methyl methacrylate (MMA)) or unreactive (toluene), on foam morphology has been determined. The morphology was found to depend on the type of diluent: styrene resulted in cellular materials at low PLA levels but tended to give structures characteristic of phase separation at higher PLA content; MMA yielded porous cellular materials at all levels of PLA; toluene tended to give soft materials that collapsed on drying. The swelling of the foam materials in toluene, isopropyl alcohol (IPA) and water was also investigated. It was found that most of the foams swelled to a relatively low extent in all solvents, apart from that of low PLA content made with toluene. This was ascribed to a low crosslinking level and high porosity of this material. Cell and tissue growth studies on the resulting foams, as well as analogues prepared from poly(ε‐caprolactone) (PCL) macromonomers, using whole chicken embryo explants, rat skin explants or individual human skin cells, indicated excellent biocompatibility of all foams over the length of each experiment (maximum length 6 days). Comparative studies indicated that cells adhered to PCL‐based materials more rapidly than their PLA‐containing counterparts.

© 2002 Society of Chemical Industry
From prebiotic macromolecules to synthetic polypeptides: a new, efficient synthesis of α‐amino acid N‐carboxyanhydrides (NCAs)
Authors: Boiteau Laurent , Collet Hélène , Lagrille Olivier , Taillades Jacques , Vayaboury Willy , Giani Olivia , Schué François , Commeyras Auguste
Published: October 2002

While polypeptide materials present important application potentialities, the expense of amino acid N‐carboxyanhydride (NCA) monomers strongly limits their applications. We present here a new, promising synthetic route to NCA through N‐carbamoylamino acid nitrosation by gaseous NOx(1 < x < 2) in the solid–gas phase. This very efficient reaction (which was originally developed in a prebiotic context) works in the absence of solvent and with minimum waste, and presents interesting economic features. Some mechanistic investigations aimed at the optimisation and scale‐up of this reaction in the solid‐gas phase are presented.

© 2002 Society of Chemical Industry
ω‐OH polystyrene and ω‐OH poly(n‐butyl acrylate) as reactive stabilizers for the preparation of uniform polyurethane particles in a dispersed medium
Authors: Cloutet Eric , Radhakrishnan Bindushree , Cramail Henri
Published: October 2002

ω‐OH polystyrene (PS‐OH) and ω‐OH poly(n‐butyl acrylate) (PnBA‐OH) have been designed to act as both stabilizers and reactants in the synthesis of polyurethanes (PURs) in a dispersed medium. Uniform PUR particles with a size ranging from 0.2 µm to 5 µm could be prepared by step‐growth polymerization of ethylene glycol (EG) and tolylene‐2,4‐diisocyanate (TDI) at 60 °C in cyclohexane, in the presence of dibutyl tin dilaurate (DBTDL) as the catalyst and either hydroxy‐terminated polystyrene (PS‐OH) or hydroxy‐terminated poly(n‐butyl acrylate) (PnBA‐OH) as the reactive stabilizer. Parameters such as the manner of addition of the reactants, the concentration and length of the stabilizer, were varied to tune the polyurethane particle size. While the molar mass of ω‐OH PnBA was allowed to increase from 6000 to 15 000 g mol−1, the particle size was found to decrease from 2 µm to 200 nm.

© 2002 Society of Chemical Industry
Elementary mechanisms of metallocene activation by methylaluminoxane cocatalysts for olefin polymerization
Authors: Pédeutour Jean‐Noël , Radhakrishnan Karunakaran , Cramail Henri , Deffieux Alain
Published: October 2002

The different elementary steps in the activation process of racEt(Ind)2ZrCl2 by commercial methylaluminoxane (MAO) have been studied by UV/visible spectroscopy and correlated with hexene polymerization kinetics. After monomethylation of the zirconocene dichloride (λ = 396 nm), abstraction of Cl ligand by MAO at low Al/Zr ratios (Al/Zr = 150) yields tight ion pairs, with an absorption band centred at λ = 440 nm, which are inactive towards hexene polymerization. Addition of MAO in large excess (Al/Zr = 2000) is required to form the active species. The latter, characterized by an absorption at λ = 470 nm, were identified as trimethylaluminium (TMA) separated ion pairs. The activation by commercial MAO of racEt(Ind)2ZrX2, with X being methyl, benzyl or dimethylamino as extractable group, instead of chloride, reveals much easier and complete activation at low Al/Zr ratios (Al:Zr = 50–150). For these systems, formation of active ion pairs of different catalytic activities and absorbing in the range λ = 430–440 nm is observed. The use of TMA‐depleted MAO instead of commercial MAO, as cocacalyst for racEt(Ind)2ZrCl2 actvation also allows the formation of active tight ion pairs absorbing at λ = 440 nm at low Al/Zr ratio. These results underline the negative role of chloride ligands when associated with TMA (contained in MAO) in the activation process of zirconocene for olefin polymerization, and also suggest interesting alternatives to reduce the amount of MAO necessary for metallocene activation.

© 2002 Society of Chemical Industry
Antitubercular constituents from the hexane fraction of Morinda citrifolia Linn. (Rubiaceae)
Authors: Saludes Jonel P. , Garson Mary J. , Franzblau Scott G. , Aguinaldo Alicia M.
Published: October 2002

A crude ethanol extract and hexane fraction from Morinda citrifolia Linn. (Rubiaceae) show antitubercular activity. The major constituents of the hexane fraction are E‐phytol, cycloartenol, stigmasterol, β‐sitosterol, campesta‐5,7,22‐trien‐3β‐ol and the ketosteroids stigmasta‐4‐en‐3‐one and stigmasta‐4‐22‐dien‐3‐one. E‐Phytol, a mixture of the two ketosteroids, and the epidioxysterol derived from campesta‐5,7,22‐trien‐3β‐ol all show pronounced antitubercular activity. Copyright © 2002 John Wiley & Sons, Ltd.
Antimicrobial potential of two different Hypericum species available in India
Authors: Mukherjee Pulok K. , Saritha G. S. , Suresh B.
Published: October 2002

The antimicrobial activity of extracts of the leaves and stems of two different varieties of Hypericum was evaluated by the disc diffusion method. Petroleum ether, acetone, chloroform and methanol extracts of Hypericum mysorense and Hypericum patulum stems and leaves were investigated for their antimicrobial activity against six different strains of bacteria and fungi by the zone of inhibition method (ZIM). The results showed that both the stem and leaf extracts of both species have a very broad spectrum of antibacterial activity. The petroleum ether and acetone extract of the leaves and stems of H. mysorense did not show antifungal effects against any of the six fungal organisms tested but other extracts showed a potential antifungal effect which was comparable to that of griseofulvin, the standard antifungal agent. Thus these results demonstrate that the leaf and stem extracts of both the Hypericum species have a very broad spectrum of activity and suggest that they may be useful in the treatment of various microbial infections. Copyright © 2002 John Wiley & Sons, Ltd.
Anti‐stress and anti‐fatigue effect of fermented rice bran
Authors: Kim K. M. , Yu K. W. , Kang D. H. , Suh H. J.
Published: October 2002

The anti‐stress and anti‐fatigue effects of a hot water extract of fermented rice bran (FRB) were investigated with Saccharomyces cerevisae IFO 2346 on rats or mice. Oral administration (1 g/kg/day) of a hot water extract of FRB inhibited major changes in weight of the adrenal, thymus, spleen and thyroid, showing the anti‐stress effect. A hot water extract of FRB also inhibited the increase of GPT and LDH activity, cholesterol and serum glucose levels. Administration (1 g/kg/day) for 2 weeks significantly prolonged the swimming time, resulting in an increase of the anti‐fatigue effect. From these results, it can be considered that FRB has an anti‐stress and anti‐fatigue effect. Copyright © 2002 John Wiley & Sons, Ltd.
Antistress effects of bacosides of Bacopa monnieri: modulation of Hsp70 expression, superoxide dismutase and cytochrome P450 activity in rat brain
Authors: Chowdhuri D. Kar , Parmar D. , Kakkar P. , Shukla R. , Seth P. K. , Srimal R. C.
Published: October 2002

The antistress effect of bacosides of Brahmi (Bacopa monnieri, BBM), dissolved in distilled water, was ­studied in adult male Sprague Dawley rats by administering oral doses of 20 and 40 mg/kg for 7 consecutive days. In half of the animals treated with 20 or 40 mg/kg of BBM, stress was given 2 h after the last dose. Stress was also administered to the animals treated with distilled water alone. BBM, at both doses, did not induce a significant change in the expression of Hsp70 in any brain region studied while stress alone produced a significant increase in the Hsp70 expression in all the brain regions. A significant decrease in the activity of superoxide dismutase (SOD) was evident in the hippocampus with the lower dose of BBM and in animals given stress alone, while an increase in the activity of SOD was observed in the brain regions with the higher dose of BBM. An increase in the activity of cytochrome P450 (P450) dependent 7‐pentoxyresorufin‐o‐dealkylase (PROD) and 7‐ethoxyresorufin‐o‐deethylase (EROD) was observed in all the brain regions after exposure to stress alone and with both doses of BBM although the magnitude of induction of P450 expression was less with a higher dose of BBM. Interestingly, stress when given to the animals pretreated with BBM for 7 days resulted in a decrease in Hsp70 expression in all the brain regions with a significant decrease occurring only in the hippocampus. Likewise the activity of SOD was found to be further reduced in all the brain regions in the animals treated with the lower dose of BBM followed by stress. However, when stress was given to the animals pretreated with the higher dose of BBM, a significant increase in the enzyme activity was observed in the cerebral cortex and in the rest of the brain while the activity of SOD was reduced to a much greater extent in the cerebellum and in the hippocampus. Likewise, the activity of P450 enzymes was found to be restored to almost control levels in the animals given stress and pretreated with the higher dose of BBM, while a lesser degree of induction, compared with animals treated with BBM or stress alone, was observed in the animals pretreated with the lower dose of BBM and given stress. The data indicate that BBM has potential to modulate the activities of Hsp70, P450 and SOD thereby possibly allowing the brain to be prepared to act under adverse conditions such as stress. Copyright © 2002 John Wiley & Sons, Ltd.
Hypoglycaemic activity of Scopariadulcis L. extract in alloxan induced hyperglycaemic rats
Authors: Pari L. , Venkateswaran S.
Published: October 2002

Scoparia dulcis L. commonly known as ‘Sweet Broomweed’ is widely used in Indian folk medicine for the treatment of diabetes mellitus. Oral administration of 0.15, 0.30 and 0.45 g/kg body weight of the aqueous extract of the Scoparia dulcis leaves (SLEt) for 45 days resulted in a significant reduction in blood glucose, glycosylated haemoglobin and an increase in total haemoglobin but in the case of 0.45 g/kg body weight the effect was highly significant. The aqueous extract also prevented a decrease in the body weight. An oral glucose tolerance test was also performed in experimental diabetic rats, in which there was a significant improvement in glucose tolerance in animals treated with SLEt and the effect was comparable to that of glibenclamide. Copyright © 2002 John Wiley & Sons, Ltd.
Relaxant activity of raspberry ( Rubus idaeus) leaf extract in guinea‐pig ileum in vitro
Authors: Rojas‐Vera Janne , Patel Asmita V. , Dacke Christopher G.
Published: October 2002

Tea made from the leaves of Rubus idaeus L. (raspberry) has been used for centuries as a folk medicine to treat wounds, diarrhoea, colic pain and as a uterine relaxant. Extracts of dried raspberry leaves prepared with different solvents, (n‐hexane, ethyl acetate, chloroform and methanol) were tested in vitro for relaxant activity on transmurally stimulated guinea‐pig ileum. The methanol (MeOH) extract exhibited the largest response and also indicated that the active compounds are of a relatively polar nature. Hence the bulk of the leaves were extracted with methanol and the dried extract fractionated on a silica gel column, eluting with chloroform, mixtures of chloroform and methanol and finally methanol. Each fraction was examined by thin layer chromatography and tested for relaxant activity in an in vitro transmurally stimulated guinea‐pig ileum preparation. The fractions eluted with chloroform (CHCl3) lacked relaxant activity. Samples eluted with CHCl3/MeOH (95:5) had moderate relaxant activity, while a second distinctive peak of activity eluted with a more polar solvent mixture (CHCl3/MeOH 50:50) provided strong dose dependent responses. Evidence was obtained that there are at least two components of raspberry leaf extract which exhibit relaxant activity in an in vitro gastrointestinal preparation. Copyright © 2002 John Wiley & Sons, Ltd.
Onions—A global benefit to health
Authors: Griffiths Gareth , Trueman Laurence , Crowther Timothy , Thomas Brian , Smith Brian
Published: October 2002

Onion (Allium cepa L.) is botanically included in the Liliaceae and species are found across a wide range of latitudes and altitudes in Europe, Asia, N. America and Africa. World onion production has increased by at least 25% over the past 10 years with current production being around 44 million tonnes making it the second most important horticultural crop after tomatoes. Because of their storage characteristics and durability for shipping, onions have always been traded more widely than most vegetables. Onions are versatile and are often used as an ingredient in many dishes and are accepted by almost all traditions and cultures. Onion consumption is increasing significantly, particularly in the USA and this is partly because of heavy promotion that links flavour and health. Onions are rich in two chemical groups that have perceived benefits to human health. These are the flavonoids and the alk(en)yl cysteine sulphoxides (ACSOs). Two flavonoid subgroups are found in onion, the anthocyanins, which impart a red/purple colour to some varieties and flavanols such as quercetin and its derivatives responsible for the yellow and brown skins of many other varieties. The ACSOs are the flavour precursors, which, when cleaved by the enzyme alliinase, generate the characteristic odour and taste of onion. The downstream products are a complex mixture of compounds which include thiosulphinates, thiosulphonates, mono‐, di‐ and tri‐sulphides. Compounds from onion have been reported to have a range of health benefits which include anticarcinogenic properties, antiplatelet activity, antithrombotic activity, antiasthmatic and antibiotic effects. Here we review the agronomy of the onion crop, the biochemistry of the health compounds and report on recent clinical data obtained using extracts from this species. Where appropriate we have compared the data with that obtained from garlic (Allium sativum L.) for which more information is widely available. Copyright © 2002 John Wiley & Sons, Ltd.
Anxiolytic and antiemetic activity of Zingiber officinale
Authors: Vishwakarma S. L. , Pal S. C. , Kasture Veena S. , Kasture S. B.
Published: October 2002

The benzene fraction (BF) of a petroleum ether extract of dried rhizomes of ginger, which contained anticonvulsant principle(s), was screened for anxiolytic and antiemetic activity. Motor coordination was not affected by BF per se, but diazepam‐induced motor incoordination was potentiated. Animals treated with BF showed decreased occupancy in the closed arm of the elevated plus maze suggesting the presence of anxiolytic principles in the BF. BF also blocked lithium sulphate‐induced conditioned place aversion indicating antiemetic activity. These findings suggest that the fraction (BF) possesses anticonvulsant, anxiolytic and antiemetic activity. Copyright © 2002 John Wiley & Sons, Ltd.
Effects of black radish root (Raphanus sativus L. var niger) on the colon mucosa in rats fed a fat rich diet
Authors: Sipos P , Hagymási K , Lugasi A , Fehér E , Blázovics A
Published: October 2002

The effect of black radish root (Raphanus sativus L. var niger) was studied on the structure and redox state of the colon mucosa in fat‐rich diet fed rats. The epithelial lining disrupted, the number of enterocytes and the goblet cells reduced and inflammatory cells were observed in rats fed with a fat‐rich diet. After treatment with granules from black radish root all of the histopathological changes and parameters of the redox state caused by the fat‐rich diet were improved. The structure of the epithelial cells was similar to the controls, the number of goblet cells increased and no inflammation was observed. Copyright © 2002 John Wiley & Sons, Ltd.
Potential roles of cellular proteins in HIV‐1
Authors: Ott David E.
Published: October 2002

Human immunodeficiency virus type‐1 particles contain host proteins, both on their surface and interior. This review summarises the cellular proteins found in these virions and covers some of their potential roles in the viral life cycle and pathogenesis. For most proteins studied, their role and function are either unknown or in the hypothesis stage. This reflects the relatively recent emphasis given to these proteins by the HIV‐1 field as well as the incomplete understanding of their function in the cell. The study of cellular proteins in HIV‐1 promises to help us better understand the interaction of this virus with the cell, the immune system, and the whole human host as well as to shed light on the nature of AIDS and suggest more targets for therapeutic intervention. Finally, many of the cell systems themselves are still poorly understood. The extensive study of HIV‐1 has already brought increased attention to the fields of immunology and vaccine science and, in the same way, might assist our understanding of the cellular pathways themselves. Published in 2002 by John Wiley & Sons, Ltd.
Environment, economy and society: fitting them together into sustainable development
Authors: Giddings Bob , Hopwood Bill , O'Brien Geoff
Published: October 2002

Sustainable development is a contested concept, with theories shaped by people's and organizations' different worldviews, which in turn influence how issues are formulated and actions proposed. It is usually presented as the intersection between environment, society and economy, which are conceived of as separate although connected entities. We would argue that these are not unified entities: rather they are fractured and multi‐layered and can be considered at different spatial levels. The economy is often given priority in policies and the environment is viewed as apart from humans. They are interconnected, with the economy dependent on society and the environment while human existence and society are dependent on, and within the environment. The separation of environment, society and economy often leads to a narrow techno‐scientific approach, while issues to do with society that are most likely to challenge the present socio‐economic structure are often marginalized, in particular the sustainability of communities and the maintenance of cultural diversity. Copyright © 2002 John Wiley & Sons, Ltd. and ERP Environment