bluuebunny/crossref_metadata_2025 huggingface dataset:
Analysis on the Impact of FDI in Eastern China on Local Innovation
Authors: Jun Liu , Jifeng Zhang
Published: June 2022

Innovation is an important strategic support for China to accelerate the building of a strong science and technology nation. As the largest developing country attracting FDI, China's FDI has become an exogenous driving force for development, and the technology spillover generated by FDI plays a key role in improving China's innovation capacity. In order to further study the impact of FDI on local innovation in eastern China, based on the panel data from 2008 to 2018, this paper takes 12 provinces, municipalities and autonomous regions in eastern China as research samples to make an empirical analysis on the data of FDI and the relevant indicators of local innovation capability. Based on the empirical results, it is concluded that FDI, R&D personnel input, the degree of trade openness and the level of economic development all have a significant promotion effect on the improvement of local innovation capability in the east, but R&D capital investment, on the contrary, has a suppressing effect on local innovation capability in the east to a certain extent. According to the conclusion, this paper puts forward some suggestions that we should attract high-quality foreign investment, invest R&D funds reasonably, increase the investment of R&D personnel and expand the level of opening to the outside world.
T cell receptor‐mediated stimulation of mouse thymocytes induces up‐regulation of the GM2/GD2 synthase gene
Authors: Takamiya Kogo , Yamamoto Akihito , Yamashiro Shuji , Furukawa Keiko , Haraguchi Masashi , Okada Masahiko , Ikeda Takayoshi , Shiku Hiroshi , Furukawa Koichi
Published: July 2002

cDNA clones of the mouse GM2/GD2 synthase (EC 2.4.1.92) gene were isolated, and their analyses revealed that the protein has a type II transmembrane structure with 533 amino acids, which was very similar to the human homolog except for the mRNA size. The mRNA level in thymocytes dramatically increased after treatment with anti‐CD3 monoclonal antibody, whereas it was not elevated when treated with prostaglandin E2. In situ hybridization showed an elevation of mRNA levels in medullar thymocytes, suggesting that T cell receptor‐mediated signaling induces up‐regulation of the GM2/GD2 synthase gene in mature thymocytes.
Proposed cation‐π mediated binding by factor Xa: a novel enzymatic mechanism for molecular recognition
Authors: Lin Zhaolan , Johnson Michael E.
Published: July 2002

Factor Xa (FXa) is an important serine protease in the blood coagulation cascade. Small synthetic competitive inhibitors of FXa are under development as potential anticoagulants. To better understand FXa structural features and molecular recognition mechanisms, we have constructed three dimensional models of FXa‐inhibitor complex structures via a new search approach that samples conformational space and binding space simultaneously for DABE and DX‐9065a, two bis amidinoaryl derivatives that are among the most potent and selective FXa inhibitors reported to date. We find the most probable binding modes for the two inhibitors to be a folded conformation, with one distal amidino group extending into the S1 pocket, forming a salt‐bridge with FXa Asp‐189, and the other positively charged group fitting into the S4 subsite, and stabilized by a cation‐π interaction. We propose as a hypothesis that the cavity‐like S4 subsite formed by the three π‐faces of the aromatic residues Tyr‐99, Phe‐174 and Trp‐215 is sufficiently rich in π electrons that it is not only a hydrophobic pocket, but also forms a cation recognition site. This proposed cation‐π binding mechanism is one of the first proposed for enzymatic molecular recognition, and for which experimental verification can be obtained without any complicating charge compensation mechanism. Our models provide plausible explanations of the structure‐activity relationships observed for these inhibitors, and suggest that cation‐π interactions may provide a novel mechanism for molecular recognition.
DNA binding site of the yeast heteromeric Ino2p/Ino4p basic helix‐loop‐helix transcription factor: structural requirements as defined by saturation mutagenesis
Authors: Schüller Hans-Joachim , Richter Karin , Hoffmann Brigitte , Ebbert Ronald , Schweizer Eckhart
Published: July 2002

The inositol/choline‐responsive element (ICRE) is an 11 bp cis‐activating sequence motif with central importance for the regulated expression of phospholipid biosynthetic genes in the yeast Saccharomyces cerevisiae. The ICRE containing the CANNTG core binding sequence (E‐box) of basic helix‐loop‐helix (bHLH) regulatory proteins is recognized by the heteromeric bHLH transcription factor Ino2p/Ino4p. In this study, we define the Ino2p/Ino4p consensus binding sequence (5′‐WYTTCAYR‐TGS‐3′) based on the characterization of all possible single nucleotide substitutions. Interestingly, this analysis also identified a single functional deviation (CACATTC) from the CANNTG core recognition element of bHLH proteins. The DNA binding specificities of different yeast bHLH proteins may now be explained by distinct nucleotide preferences especially at two positions immediately preceding the CANNTG core motif.
Characterisation of anArabidopsis thalianacDNA encoding glutathione synthetase
Authors: Rawlins Marion R. , Leaver Christopher J. , May Mike J.
Published: July 2002

AnArabidopsis thalianacDNA (AtGSHS) encoding a protein with high primary sequence identity to cDNAs previously isolated fromXenopus laevis(42%),Schizosaccharomyces pombe(40%),Rattus norvegicus(40%) andHomo sapiens(37%) encoding glutathione synthetase (EC 6.3.2.3) has been isolated by functional complementation of anEscherichia colimutant deficient in this enzyme. AtGSHS is encoded by a single gene,GSHB, as determined by Southern blot analysis and the corresponding mRNA is abundant in both roots and leaves ofArabidopsis.
Carcinoma of the uterine cervix associated with schistosomiasis and induced by human papillomaviruses
Authors: Moubayed P. , Ziehe A. , Peters J. , Mwakyoma H. , Schmidt D.
Published: July 2002

Objectives: To determine the presence of human papillomaviruses (HPVs) in cervical cancer among patients in Tanzania and to ascertain their prevalence in cases associated with schistosomiasis. Methods: In situ hybridization was applied to 31 carcinomas of the uterine cervix including 10 in which schistosomiasis co‐occurred. Twenty‐six cases in this series also exhibited koilocytic dysplasia. Results: Twenty‐six out of 31 cases revealed a specific hybridization for HPVs with varying density and distribution. A slightly higher labeling of HPV −16 than −18 was demonstrated. All schistosomiasis‐associated cancers encoded the papillomaviruses. The 31 patients were predominantly young adults, a fact that reflects sexual activity at a very young age in the ethnic communities of Africa. Conclusion: These findings shed new light on the presumed etiologic implication of schistosomiasis in the genesis of cervical cancer. In the absence of HPV, schistosomiasis is not the oncogenic causative agent for carcinoma of the uterine cervix.
Placenta previa and previous cesarean section
Authors: To W.W.K. , Leung W.C.
Published: July 2002

Objective: To assess the relationship between previous cesarean section and subsequent development of placenta previa and placenta previa with accreta. Method: The records of all patients delivered with the diagnosis of placenta previa during the 10‐year period from 1984 to 1993 were reviewed. Results: From a total of 50 485 deliveries, 421 (0.83%) had placenta previa, 43 (10.2%) of whom had a history of previous cesarean section. The incidence of placenta previa was significantly increased in those with a previous cesarean section (1.31%) compared with those with an unscarred uterus (0.75%) (R.R. 1.64). This risk increased as the number of previous cesarean sections increased (R.R. 1.53 for one previous section, 2.63 for two or more). The incidence of an anterior placenta previa and placenta accreta was significantly increased in those with previous cesarean scars. The incidence of placenta accreta was 1.18% among patients with placenta previa, 80% being in patients with previous cesarean section. The relative risk for placenta accreta in patients with placenta previa was 35 times higher in those with a previous cesarean section than in those with an unscarred uterus. Conclusion: The association of previous cesarean section with placenta previa and placenta previa accreta is confirmed. Patients with an antepartum diagnosis of placenta previa who have had a previous cesarean section should be considered at high risk for developing placenta accreta.
From the Editor
Authors: Mandell Lewis
Published: July 2002

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Probabilistic Estate Planning
Authors: Crabb Ronald R.
Published: July 2002

Probabilistic estateplanning is based on the principle of maximizing expected net present value commensurate with the riskassumed. Rather than assuming that death occurs at life expectancy, probabilistic estate planning treats death as a random variable. Compounded to randomly chosen ages of death, estate assets are taxed and distributed to heirs. The purpose of probabilistic estate planning is to find the estate plan and asset/liability combination that maximizes the expected net present value of assets passing to heirs and to convey some idea of the risk associated with that estate plan.
Letter to the Editor
Authors: Cain Michael M.
Published: July 2002

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The Individual’s Tax-Exempt Bond Portfolio Decision Under Income Uncertainty
Authors: Puelz Amy v.
Published: July 2002

In this article, an individual’s tax-exempt bond porrfolio decision is investigated. A model capturing the relationship between income uncertainty and optimal portfolio choice is defined when an individual decision-maker has the opportunity to hold higher yielding private-activity bonds. The findings in this article show that in most cases risk-averse individuals will maximize the expected utility of after-tax income by holding a large proportion of private-activity bonds in their portfolio even under income uncertainty and the risk of a minimum tax liability. Those individuals who would benefit from holding private-activity bonds in a tax-exempt portfolio are identified and the magnitude of the benefit is quantified,
An Optimization Model for Scheduling Withdrawals from Tax-Deferred Retirement Accounts
Authors: Ragsdale Cliff T. , Seila Andrew F. , Little Philip L.
Published: July 2002

As a growing number of Americans reach refiremen? age, more and more people are facing important decisions about how to withdraw savingsfrom tax-deferred retirement accounts (TDRAs). These decisions are complicated by the Federal Tax Code which imposes a number of rules and regulations on these withdrawals. Since these decisions collectively involve billions of dollars, the potential lossfrom even slightly suboptimal decision making is very large. In this paper, we present a mathematical programming model that can be used to assist retirees ami/or their advisors in determining the optimal schedule of withdrawals from TDRAs.
Targeting of the 22 kDa integral peroxisomal membrane protein
Authors: Pause Birgit , Saffrich Rainer , Hunziker Andreas , Ansorge Wilhelm , Just Wilhelm W.
Published: July 2002

Investigating targeting of the 22 kDa peroxisomal membrane protein (Pmp22p) to the peroxisomal membrane we have confined the targeting signal to amino acid residues 16–37 located in the N‐terminal cytoplasmic tail. Comparison of Pmp22p orthologous sequences revealed a conserved motif Y3xL3xP3x(KQN) which might represent the core of this targeting signal not found so far in other Pmps. Fusion of the Pmp22p N‐terminal tail to the C‐terminal portion of Pmp22p which per se is not targeted to peroxisomes, conveys peroxisomal targeting. These data suggest that Pmp22p is targeted to peroxisomes by a new membrane targeting signal which is necessary and sufficient to target a polypeptide containing two transmembrane spans to peroxisomes.
In vivo transfer of hepatocyte growth factor gene accelerates proliferation of hepatic oval cells in a 2‐acetylaminofluorene/partial hepatectomy model in rats
Authors: Shiota Goshi , Kunisada Takahiro , Oyama Kenji , Udagawa Akihide , Nomi Takahiro , Tanaka Kiwamu , Tsutsumi Atsushi , Isono Masato , Nakamura Takafumi , Hamada Hirofumi , Sakatani Takashi , Sell Stewart , Sato Kenzo , Ito Hisao , Kawasaki Hironaka
Published: July 2002

To clarify the effect of hepatocyte growth factor (HGF) on proliferation of hepatic oval cells, we transferred HGF gene into liver of the Solt–Farber rat model. Male Fisher 344 rats were infected with a recombinant adenovirus carrying the cDNA for HGF (pAxCAHGF) from tail vein. HGF mRNA showed its peak at 4 days, and diminished thereafter. The total and proliferating cell nuclear antigen‐positive hepatic oval cells were significantly elevated in HGF‐transferred rats, in which stem cell factor and c‐kit mRNA increased at each time point. Our results suggest that in vivo transfer of the HGF gene into liver accelerates proliferation of hepatic oval cells in the Solt–Farber model in rats.
The plant ribosome inactivating proteins luffin and saporin are potent inhibitors of HIV‐1 integrase
Authors: Au T.K , Collins R.A , Lam T.L , Ng T.B , Fong W.P , Wan D.C.C
Published: July 2002

The ribosome inactivating proteins (RIPs) are a group of proteins that are able to inactivate eukaryotic protein synthesis by attacking the 28S ribosomal RNA. Recent studies have shown that some RIPs possess strong anti‐human immunodeficiency virus (HIV) activity. In this study, several common plant RIPs including agrostin, gelonin, luffin, α‐momorcharin, β‐momorcharin, saporin and trichosanthin were examined for the ability to interfere with HIV‐1 replication in a variety of mechanistic assays in vitro. These assays included the CD4/gp120 interaction assay, HIV‐1 reverse transcriptase (RT) assay, HIV‐1 protease assay and HIV‐1 integrase assay. At the concentration of 100 nM, all RIPs appeared to enhance the CD4/gp120 interaction by about 50%. These RIPs exhibited a very weak suppressive effect on HIV‐1 RT and on HIV‐1 protease. In contrast, with the exception of agrostin, all the RIPs tested could strongly inhibit HIV‐1 integrase, the extent of inhibition ranging from 26.1 to 96.3% in an ELISA‐based assay. Two RIPs, saporin and luffin, which licited over 90% inhibition in the ELISA‐based assay, were further characterized in a radiometric assay. Both of these two RIPs evoked a strong dose‐dependent inhibition in the 3′‐end processing and strand‐transfer activities of integrase. The results from this study suggest that the anti‐HIV property of RIPs may be due to inhibition of HIV‐1 integrase.
Application of Antibody and Fluorophore‐Derivatized Liposomes to Heterogeneous Immunoassays for D‐dimer
Authors: Singh Anup K. , Kilpatrick Peter K. , Carbonell Ruben G.
Published: July 2002

Small unilamellar liposomes comprised of cholesterol and phospholipids, in which one of the lipids is labeled with a fluorophore, have been covalently functionalized with antibodies. The liposomes were conjugated with thousands of fluorescein molecules and 10−20 monoclonal antibodies per liposome. These bifunctional liposomes were used in a direct (sandwich‐type) immunoassay for the detection of thromboembolic disorders by assaying for d‐dimer. D‐dimer is the final and the smallest proteolytic product in the degradation of cross‐linked fibrin by the plasma protein plasmin. The immunoassay using liposomes was compared to a conventional immunoassay that uses a fluor−antibody conjugate. The liposomes, by virtue of having thousands of fluorophores coupled to one liposome in contrast to one or a few reporter molecules in the conventional fluor−antibody conjugate, performed better on two counts: (1) they lowered the detection limit by a factor of 120 and (2) they provided a 1 order of magnitude amplification in signal. The minimum detectable concentration (MDC) of d‐dimer was 5.6 ng/mL with the liposomal assay as compared to an MDC of 674 ng/mL with conventional fluor−antibody conjugate. The results of fluorescence assays were also compared with the results obtained by Singh et al. (Biotechnol. Prog. 1995, 11, 333–341) in an enzyme immunoassay developed using liposomes. These results demonstrate the potential of liposomes in lowering detection limits and increasing the sensitivity of immunoassays.
Lipid transfer proteins and 2S albumins as allergens
Authors: Pastorello Elide A. , Pravettoni Valerio , Trambaioli Chiara , Pompei Carlo , Brenna Oreste , Farioli Laura , Conti Amedeo
Published: July 2002

Plant lipid transfer proteins, a widespread family of proteins, have been recently identified as important food allergens. Their common structural features, such as eight conserved cysteines forming disulfide bridges, basic isoelectric point and high similarity in amino acid sequence, are the basis of allergic clinical cross‐reactivity. This has been demonstrated for the LTP allergens of the Prunoideae subfamily, whose similarity is about 95% as demonstrated for the purified allergens of peach, apricot, plum and apple. A relevant aspect is the existence of sequence homology of LTPs of botanically unrelated foods, as demonstrated for LTPs of maize and peach. A class of food allergens of well recognized clinical importance is that of seed storage 2S albumins. They have been identified in the most diffused edible seeds and nuts, such as mustard, sesame, Brazil nut, walnut and peanut. In particular, a strong correlation between IgE‐binding to these proteins and food‐induced anaphylaxis has been demonstrated for Brazil nut and sesame seeds.
Reactivity toward deamidation of asparagine residues in β‐turn structures
Authors: Xie M. , Borchardt R.T. , Topp E.M. , Schowen R.L. , Aubé J. , Morton M. , Vander Velde D.
Published: July 2002

Mimetics of β‐turn structures in proteins have been used to calibrate the relative reactivities toward deamidation of asparagine residues in the two central positions of a β‐turn and in a random coil. N‐Acetyl‐Asn‐Gly‐6‐aminocaproic acid, an acyclic analog of a β‐turn mimic undergoes deamidation of the asparaginyl residue through a succinimide intermediate to generate N‐acetyl‐Asp‐N‐Gly‐6‐aminocaproic acid (6‐aminocaproic acid, hereafter Aca) and N‐acetyl‐l‐iso‐aspartyl (isoAsp)‐Gly‐Aca (pH 8.8, 37 °C) ≈ 3‐fold faster than does the cyclic β‐turn mimic cyclo‐[L‐Asn‐Gly‐Aca] with asparagine at position 2 of the β‐turn. The latter compound, in turn, undergoes deamidation ≈ 30‐fold faster than its positional isomer cyclo‐[Gly‐Asn‐Aca] with asparagine at position 3 of the β‐turn. Both cyclic peptides assume predominantly β‐turn structures in solution, as demonstrated by NMR and circular dichroism characterization. The open‐chain compound and its isomer N‐acetyl‐Gly‐Asn‐Aca assume predominantly random coil structures. The latter isomer undergoes deamidation 2‐fold slower than the former. Thus the order of reactivity toward deamidation is: asparagine in a random coil ≈ 3× asparagine in position 2 of a β‐turn ≈ 30× asparagine in position 3 of a β‐turn.
Control mechanisms operating for lipid biosynthesis differ in oil-palm (Elaeis guineensis Jacq.) and olive (Olea europaea L.) callus cultures
Authors: RAMLI Umi S. , BAKER Darren S. , QUANT Patti A. , HARWOOD John L.
Published: July 2002

As a prelude to detailed flux control analysis of lipid synthesis in plants, we have examined the latter in tissue cultures from two important oil crops, olive (Olea europaea L.) and oil palm (Elaeis guineensis Jacq.). Temperature was used to manipulate the overall rate of lipid formation in order to characterize and validate the system to be used for analysis. With [1-14C]acetate as a precursor, an increase in temperature from 20 to 30°C produced nearly a doubling of total lipid labelling. This increase in total lipids did not change the radioactivity in the intermediate acyl-(acyl carrier protein) or acyl-CoA pools, indicating that metabolism of these pools did not exert any significant constraint for overall synthesis. In contrast, there were some differences in the proportional labelling of fatty acids and of lipid classes at the two temperatures. The higher temperature caused a decrease in polyunsaturated fatty acid labelling and an increase in the proportion of triacylglycerol labelling in both calli. The intermediate diacylglycerol was increased in olive, but not in oil palm. Overall the data indicate the suitability of olive and oil-palm cultures for the study of lipid synthesis and indicate that de novo fatty acid synthesis may exert more flux control than complex lipid assembly. In olive, diacylglycerol acyltransferase may exert significant flux control when lipid synthesis is rapid.
Post-translational integration and oligomerization of connexin 26 in plasma membranes and evidence of formation of membrane pores: implications for the assembly of gap junctions
Authors: AHMAD Shoeb , EVANS W. Howard
Published: July 2002

Gap-junction channels provide a widespread intercellular signalling mechanism. They are constructed of a family of connexin membrane proteins that thread across the membrane four times and oligomerize to generate hexameric gap-junction hemichannels. Using an in vitro cell-free transcription/translation system, we demonstrate that connexin (Cx) 26, one of the smallest connexins, is integrated directly in a post-translational manner into plasma membranes. Protein-cleavage studies of Cx26 integrated into plasma membranes indicate a similar native transmembrane topography to that of Cx26 integrated co-translationally into microsomes. Cx26 integrated post-translationally into plasma membranes oligomerizes and, when incorporated into liposomes, provides permeability to ascorbic acid, suggesting that gap-junction hemichannels are generated. The results provide the basis of a novel alternative mechanism for spontaneous assembly in plasma membranes of Cx26 gap-junction hemichannels that occurs independently of the conventional biogenesis of gap junctions involving connexin trafficking and oligomerization via membrane components of the secretory pathway.
Characterization of glycosphingolipids from Schistosoma mansoni eggs carrying Fuc(α1–3)GalNAc‐, GalNAc(β1–4)[Fuc(α1–3)]GlcNAc‐ and Gal(β1–4)[Fuc(α1–3)]GlcNAc‐ (Lewis X) terminal structures
Authors: Wuhrer Manfred , Kantelhardt Sven R. , Dennis Roger D. , Doenhoff Michael J. , Lochnit Günter , Geyer Rudolf
Published: July 2002

The carbohydrate moieties of glycosphingolipids from eggs of the human parasite, Schistosoma mansoni, were enzymatically released, labelled with 2‐aminopyridine (PA), fractionated and analysed by linkage analysis, partial hydrolysis, enzymatic cleavage, matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry and nano‐electrospray ionization mass spectrometry. Apart from large, highly fucosylated structures with five to seven HexNAc residues, we found short, oligofucosylated species containing three to four HexNAc residues. Their structures have been determined as Fuc(α1–3)GalNAc(β1–4)[ ± Fuc (α1–3)]GlcNAc(β1–3)GalNAc(β1–4)Glc‐PA, GalNAc(β1–4)[Fuc(α1–3)]GlcNAc(β1–3)GlcNAc(β1–3)GalNAc(β1–4) Glc‐PA, Fuc(α1–3)GalNAc(β1–4)[Fuc(α1–3)]GlcNAc(β1–4) GlcNAc(β1–3)GalNAc(β1–4)Glc‐PA, and Fuc(α1–3) GalNAc(β1–4)[ ± Fuc(α1–2) ± Fuc(α1–2)Fuc(α1–3)]Glc NAc(β1–3)GlcNAc(β1–3)GalNAc(β1–4)Glc‐PA. The last structure exhibits a trifucosyl sidechain previously identified on the cercarial glycocalyx. These structures stress the importance of 3‐fucosylated GalNAc as a terminal epitope in schistosome glycoconjugates. To what degree these glycans contribute to the pronounced antigenicity of S. mansoni egg glycolipids remains to be determined. In addition, we have identified the compounds GlcNAc(β1–3)GalNAc(β1–4)Glc‐PA, Gal(β1–4)[Fuc(α1–3)]GlcNAc(β1–3) GalNAc (β1–4)Glc‐PA, the latter of which is a Lewis X‐pentasaccharide identical to that present on cercarial glycolipids, as well as Gal(β1–3)GalNAc(1–4)Gal(1–4)Glc‐PA, which corresponds to asialogangliotetraosylceramide and is most probably derived from the mammalian host.
Patients' understanding of risk and benefit associated with carotid endarterectomy
Authors: Lloyd A J , Hayes P D , Naylor A R , Bell P R F
Published: July 2002

Background

Recent well publicized cases have highlighted problems regarding a patient's perception of risk and the provision of informed consent which currently forms the medicolegal and ethical basis of modern healthcare practice. This study was designed to determine whether patients understood the risks of stroke associated with carotid endarterectomy (CEA).

Methods

All patients were counselled by the surgeon before going on the waiting list. Patients were informed that the risk of stroke due to surgery was 2·5 per cent and that 3 years after CEA a further 5 per cent of patients will also have suffered a stroke. This compares with a 20–30 per cent risk of stroke at 3 years in patients treated medically. Some 71 patients on the waiting list for CEA were surveyed regarding their understanding of the risk and benefit to health of undergoing CEA.

Results

Patients' estimates of stroke risk due to surgery ranged from 0 to 65 per cent (actual risk 2 per cent). Patients also dramatically overestimated their risk of stroke without the operation (mean 57 per cent). In addition to preventing stroke, most patients also believed that CEA would improve angina, poor memory or shortness of breath. When resurveyed the day before the operation patients' perception of risk associated with surgery had increased threefold (P < 0·01).

Conclusion

Most patients failed to understand the risks and benefits associated with CEA. Despite best efforts, the current doctor–patient relationship still fails to furnish patients with the skills and knowledge needed for healthcare decision making. Patients' recall of statistical data is extremely limited even in the short term.
A comparison of proxy measures of abdominal obesity in Chinese, European and South Asian adults
Authors: Patel S. , Unwin N. , Bhopal R. , White M. , Harland J. , Ayis S. A. M. , Watson W. , Alberti K. G. M. M.
Published: July 2002

Aims To assess whether four proxy measures of abdominal obesity (waist circumference; waist‐to‐hip ratio (WHR); waist‐to‐height ratio and C index, a measure of body shape) were uniformly associated with features of the metabolic syndrome (triglycerides, high density lipoprotein (HDL) cholesterol, 2‐h glucose) in three ethnic groups.

Methods Anthropometric and biochemical data were collected in 629 Europeans (320 men, 309 women), 380 Chinese (183 men, 197 women) and 597 South Asians (275 men, 322 women) aged 25–64 years in Newcastle upon Tyne, UK. Linear regression models were used to determine whether relationships differed between ethnic groups.

Results Linear regression analysis showed that most proxy measures of abdominal obesity were associated with features of the metabolic syndrome. There were significant interactions between WHR and ethnicity and C index and ethnicity in the relationship with log triglycerides when comparing European and Chinese women. Interactions existed between all proxy measures and ethnicity in the relationship with log triglycerides and HDL cholesterol when comparing European and South Asian women. In men, interactions between ethnicity and waist circumference, WHR and C index when comparing Europeans and South Asians, and between ethnicity and WHR and C index when comparing South Asian and Chinese for log 2‐h glucose were significant (P < 0.001). All interactions remained significant when differences in smoking, alcohol and physical activity were taken into account.

Conclusions Not all the proxy measures of abdominal obesity were consistently related to features of the metabolic syndrome across the ethnic groups studied. However, waist circumference and waist to height ratio were the most consistent and WHR the least when comparing across the ethnic groups.
Reverse end‐diastolic umbilical artery blood flow at 11 weeks' gestation
Authors: Montenegro N. , Beires J. , Pereira Leite L.
Published: July 2002

This report describes a case of reverse end‐diastolic blood flow in the umbilical artery of one of the fetuses of a twin pregnancy at 11 weeks' gestation. Cytogenetic studies after amniocentesis performed at 12 weeks revealed a 45, X karyotype of this twin whose death was registered 1 week later. Spontaneous delivery of the co‐twin occurred at 37 weeks; the newborn was healthy and normal.

This is the earliest record of reverse diastolic flow in the umbilical artery. Even in the first trimester of pregnancy this is an ominous sign and fatal demise is expected. Copyright © 1995 International Society of Ultrasound in Obstetrics and Gynecology
Distribution of Carabid Beetles (Coleoptera, Carabidae) across a Boreal Forest–Clearcut Ecotone
Authors: Heliölä Janne , Koivula Matti , Niemelä Jari
Published: July 2002

Abstract: We studied the occurrence of carabid beetles (Coleoptera, Carabidae) in boreal forest fragments, their edges, and adjacent clearcuts in central Finland. Beetles were collected with pitfall traps along transects extending 60 m from the edge into clearcuts and 60 m into forest interior. Our main findings were that (1) species richness was significantly higher in the clearcut than in the forest fragments, (2) clearcuts hosted many open‐habitat species, which increased overall species richness in these sites, (3) carabid assemblages in the edges were more similar to forest assemblages than to those found in the clearcuts, (4) no edge specialists were found, and (5) open‐habitat species did not penetrate into the forest fragments from the clearcut. Because forest specialists occurred all the way to the edge on the forest side, it seems that edge effects per se do not adversely affect these species, at least in the short term. In the long term, however, habitat conditions in the edges may deteriorate for interior species because of trees falling over in strong winds, thereby reducing the size of the fragments and widening the edge zone.
Restoration of Wet Dune Slacks on the Dutch Wadden Sea Islands: Recolonization After Large‐Scale Sod Cutting
Authors: Grootjans Ab P. , Everts Henk , Bruin Kees , Fresco Latzi
Published: July 2002

The effects of sod cutting were studied in a dune area on the Dutch Wadden Sea Island of Texel. Sod cutting was carried out in a range of different dune slacks in order to restore dune slack vegetation with many endangered Red List species. Sod cutting removed approximately 96% of the soil seed bank. Species abundant in the seed bank, notably Juncacea, also had a high frequency in the vegetation that established during the first year after the restoration measures. Many other species not registered in the seed bank or in the former vegetation also appeared. Species richness in the monitored plots exceeded that of uncut reference plots after a few years. Colonization rates were higher than extinction rates in most plots, indicating that a stable state has not been reached after 5 years. Differences in species richness between slacks appeared to be related to the occurrence of source areas nearby and availability of dispersal agents, such as flooding and animals.
Antiepileptic Drugs in Migraine Prevention
Authors: Mathew Ninan T.
Published: July 2002

Migraineurs may continue to experience attacks, despite daily use of one or more agents from a wide range of drugs, including β‐blockers, calcium channel blockers, serotonin antagonists, tricyclic antidepressants, monoamine oxidase inhibitors, and antiepileptic agents. Divalproex sodium is the only antiepileptic drug approved for migraine prevention. Gabapentin, topiramate, and other antiepileptic agents are being evaluated for migraine prevention and treatment. Prospective, double‐blind, placebo‐controlled clinical trials of divalproex, gabapentin, and topiramate for migraine prevention generally were composed of a prospective baseline period, a dose titration period, and a fixed‐dose treatment period. The primary efficacy variable was a reduction in the 28‐day frequency of migraine headache. Patients receiving divalproex for 12 weeks at doses up to 1500 mg/day achieved significant decreases in the migraine frequency (P<.05), corresponding to reductions of 30% to 40% compared with baseline. Nearly half of the divalproex‐treated patients had a 50% or more reduction from baseline in headache frequencies (P.05). Asthenia, vomiting, somnolence, tremor, and alopecia were common adverse events associated with divalproex. Significant reductions in migraine frequency were also observed with gabapentin (1800 to 2400 mg/day) when compared with placebo (P<.01), and nearly half of all patients treated at the highest dose experienced a reduction in headache rate of 50% or more. Somnolence was the most commonly reported adverse event among the gabapentin‐treated patients. Two single‐center, double‐blind, placebo‐controlled clinical trials evaluated topiramate for migraine prevention. A lower 28‐day migraine frequency was seen during 18 weeks of administration at a maximum daily dose of 200 mg (P = .09). In a second study, a significantly lower mean 28‐day migraine frequency was observed during 16 weeks of treatment with topiramate (P = .0015). Mean reduction in migraine frequency was also significantly greater in topiramate‐treated patients (P = .0037). Paresthesias, diarrhea, somnolence, and altered taste were commonly reported adverse events in the topiramate‐treated patients. Unlike some patients given divalproex or gabapentin, some given topiramate reported weight loss. Large, double‐blind, placebo‐controlled trials may prove the effectiveness of novel antiepileptic drugs in migraine prevention.
Oxygen atom thermal vibration anisotropy in Ba0.87K0.13BiO3
Authors: Wignacourt J. P. , Swinnea J. S. , Steinfink H. , Goodenough J. B.
Published: July 2002

Crystals of Ba1−xKxBi2O3 were obtained from a melt of a mixture of Ba(OH)2⋅8H2O, Bi2O3 (0.6Ba:1Bi), and excess KOH heated at 360 °C in air. Single-crystal x-ray diffraction data show that the crystals are cubic a=4.3223(5) Å, space group Pm3m. The 55 unique reflections resulting from averaging 1364 measured intensities were used to refine the structure by least squares to R=0.0089, wR=0.0076. The atomic positional parameters are fixed by symmetry; the refinement of the Ba occupancy factor yields the value 0.872(6). The thermal vibration parameters for the cations are constrained to be spherical; the oblate vibration ellipsoid for oxygen yields rms displacements of 0.258(5) Å perpendicular to the Bi-Bi distance and 0.12(1) Å parallel to it. A prolate ellipsoid for the oxygen anisotropic thermal displacement parameters would have indicated a softening of ‘‘breathing’’ modes at the bismuth atoms. Instead, an oblate spheroid locks the oxygen atoms at mid-bismuth positions with enhanced vibrations perpendicular to the Bi-Bi distance. The potassium substitution suppresses the Bi(III)-Bi(V) disproportionation observed in BaBiO3.
Room-temperature exciton electroabsorption in partially intermixed GaAs/AlGaAs quantum well waveguides
Authors: Ralston J. D. , Schaff W. J. , Bour D. P. , Eastman L. F.
Published: July 2002

Perpendicular field electroabsorption is measured for the first time in GaAs/AlGaAs quantum well (QW) structures which have been modified via partial interdiffusion of the well and barrier layers. In waveguide samples containing two GaAs QWs, the impurity-free vacancy diffusion process is shown to allow continuously variable permanent band-edge energy shifts of at least 40 meV while still retaining clearly resolved heavy hole and light hole exciton absorption peaks at room temperature. Furthermore, the quantum-confined Stark effect is shown to be preserved in the partially intermixed structures, greatly expanding the range of photon energies over which such behavior can be utilized in a single epitaxially grown sample. Transmission resonance calculations are used to model the observed enhanced electric-field-induced broadening of exciton absorption peaks in the partially intermixed QWs due to increased carrier tunneling through the graded and lowered potential barriers.
Exponential temperature dependence of the critical transport current in Y-Ba-Cu-O thin films
Authors: Yom S. S. , Hahn T. S. , Kim Y. H. , Chu H. , Choi S. S.
Published: July 2002

We have measured the critical currents in rf-sputtered YBa2Cu3O7−x thin films deposited on polycrystalline yttria-stabilized zirconia substrates as a function of temperature down to 10 K. The dependence of the granular films at low temperature indicated exponential behavior which is similar to the superconductor-normal metal-superconductor (S-N-S) type tunneling junctions. For the films with a grain size of approximately 1 μm, we observed two exponential decay constants, which suggest that Josephson junctions limiting the transport critical current are possible both at the grain boundaries and at twin boundaries.
Wet chemical techniques for passivation of YBa2Cu3O7−x
Authors: Vasquez R. P. , Foote M. C. , Hunt B. D.
Published: July 2002

Wet chemical techniques are described for treatment of YBa2Cu3O7−x surfaces, resulting in the formation of native compounds with little or no reactivity to water. Promising native compounds include CuI, BaSO4, CuS, Cu2S, and the oxalates, all of which are either insoluble or have very low solubility in water. Treatment with dilute HI results in the formation of anative iodide film which is 80–90% CuI with small amounts of YI3 and BaI2. Treatment with dilute H2SO4 results in the formation of a film which is 95% BaSO4 and 5% Y2(SO4)3. Cu2S is formed on the surface with a dilute Na2S solution. An oxalate film with equal amounts of Y2(C2O4)3 and BaC2O4 results from treatment with dilute oxalic acid. X-ray photoelectron spectra show no significant changes when the sulfide, sulfate, or oxalate films are dipped in water, while the iodide film shows evidence of Cu(OH)2 formation.
Picosecond hole dynamics in GaAs grown on silicon
Authors: Shum Kai , Takiguchi Y. , Mohaidat J. M. , Liu Feng , Alfano R. R. , Morkoç H.
Published: July 2002

Picosecond hole dynamics in GaAs grown on silicon substrate are reported for the first time using time- and energy-resolved photoluminescence spectroscopy. The emission spectrum is attributed to transitions from electrons in donor (Si, 1016 cm−3) states to the internal stress separated heavy hole and light hole bands [(D°→hh), (D°→lh)]. The intraband thermalization process for heavy holes is observed to be faster than for light holes. The intervalence-band thermalization time of holes is found to be about 11 ps. The hole cooling rate is measured to be six times smaller than expected based on hole scatterings with longitudinal optical phonons.
Novel alignment technique for surface stabilized ferroelectric liquid crystal
Authors: Bawa S. S. , Biradar A. M. , Saxena K. , Chandra S.
Published: July 2002

An alignment method for obtaining excellent surface stabilized ferroelectric liquid-crystal devices is described. Alignment is obtained by obliquely depositing the SiO in two steps. The first deposition involves vacuum coating at 60° angle and the second at 85° (orthogonally to the first) with the substrate normal. The method induces a high (∼20°–25°) pretilt surface which depends on the thickness of the second layer. The glass substrates are matched with antiparallel direction of evaporation of second coating. This ensures a selective pretilt of molecules and the uniformly tilted smectic layer structure. The advantages of this new method are the ease of large-scale production, defect-free large uniform monodomains, good contrast, bistability, and microsecond switching speed response.
Heteroepitaxial growth of Ge on (100) Si by ultrahigh vacuum, chemical vapor deposition
Authors: Cunningham Brian , Chu Jack O. , Akbar Shah
Published: July 2002

The heteroepitaxial growth of pure Ge films on (100) Si by an ultrahigh vacuum, chemical vapor deposition technique is reported for the first time. The growth mode is found to be critically dependent on the substrate temperature during deposition. Two temperature regimes for growth are observed. Between 300 and 375 °C, growth occurs in a two-dimensional, layer-by-layer mode, with an activation energy of 1.46 eV. Above 375 °C, island formation is observed. In the low-temperature regime the growth rate is controlled by a surface decomposition reaction, whereas in the high-temperature regime the growth rate is controlled by diffusion and adsorption from the gas phase.
Anomalous temperature dependencies of photoluminescence for visible-light-emitting porous Si
Authors: Zheng X. L. , Wang W. , Chen H. C.
Published: July 2002

Porous Si has been prepared by the electrochemical anodization method. At room temperature it has a light-emission peak energy in the range of 1.50–2.06 eV. The results from variable-temperature photoluminescence (PL) show anomalous temperature dependencies of the spectral characteristics: the emission intensity increases with decreasing temperature until reaching an intensity maximum at about 100–200 K, then it decreases at lower temperatures; the emission energy shift with temperature has no fixed trend and varies with sampling point. Such dependencies are reversible with the two directions of temperature change. The above observations can be explained by phonon participation in the light-emission process of porous Si.
Far infrared photoelectric thresholds of extrinsic semiconductor photocathodes
Authors: Perera A. G. U. , Sherriff R. E. , Francombe M. H. , Devaty R. P.
Published: July 2002

Far infrared detection is demonstrated in forward biased Ge (out to 240 μm), Si (220 μm), and InGaAs (90 μm) p-i-n diodes with D up to 5×1010 cm Hz1/2/W at 4.2 K. For silicon detectors, this is the longest response wavelength ever reported. Estimates for the responsivity and the detectivity for unoptimized commercial samples are provided by comparison with a silicon composite bolometer. The variations observed in the long wavelength threshold (λt) suggest that if correlations with device processing parameters can be successfully established, this approach can be used to tailor detectors for different IR wavelength regions. Spectral response comparison with a single p-i structure strongly supports the detection mechanism and opens the possibility of detector optimization using multilayered structures.
Thermal-stress-induced voiding in narrow, passivated Cu lines
Authors: Bo/rgesen P. , Lee J. K. , Gleixner R. , Li C.-Y.
Published: July 2002

Copper is being considered as an alternative to aluminum-based metallizations in microelectronic circuits, both because copper is a better conductor and because it is expected to be more resistant to thermal stress and electromigration induced failure. However, thermal stresses are found to cause significant voiding in passivated copper lines, in a manner very similar to that commonly observed for passivated aluminum lines.
Strain-induced lateral carrier confinement in quantum wells grafted onto nonplanar substrates
Authors: Chan Winston K. , Ravi T. S. , Kash K. , Christen Jürgen , Gmitter Thomas J. , Florez Leigh T. , Harbison James P.
Published: July 2002

We remove a thin semiconductor film from its growth substrate and reattach it to a nonplanar host substrate. The film is under a large, localized bending stress. In a GaAs/AlGaAs film with a quantum well near one surface where the bending strain is greatest, carriers are laterally confined by the strain to regions where the band gap is red-shifted by up to 62 meV.
Vacuum-deposited metal/polyaniline Schottky device
Authors: Misra S. C. K. , Ram M. K. , Pandey S. S. , Malhotra B. D. , Chandra Subhas
Published: July 2002

All vacuum-deposited metal/semiconducting polyaniline hetrojunction Schottky devices using vacuum-evaporated polyaniline films of a thickness of the order of 0.1 μm have been prepared. Schottky junctions have been formed using the following metals, Al, Sn, In, Pb, Sb, and Ag. Electrical characterization has been carried out and electronic parameters, including the barrier height and ideality factor, have been determined. Infrared optical absorption spectroscopy of the vacuum-deposited polyaniline films were used to determine the structure, energy band gap, and effect of various ambients on the vacuum-deposited polyaniline films.
Dry lithography using focused ion beam implantation and reactive ion etching of SiO2
Authors: Choquette Kent D. , Harriott Lloyd R.
Published: July 2002

We report a novel dry process suitable for submicron lithography using focused ion beam writing and plasma development of SiO2. Robust masks are fashioned in layers of SiO2 with a focused Ga ion beam, followed by development using CF4/O2 reactive ion etching. We find the development selectivity (etch rate ratio) between unimplanted and implanted SiO2 increases with increasing Ga dose. Using an implant dose of 1.5×1016 cm−2 we form SiO2 line and circular dot masks with dimensions as small as 300 nm. To demonstrate the utility of these durable masks, the patterns are transferred into GaAs by reactive ion etching, producing structures with aspect ratios (depth/width) greater than 10. Since masks formed of SiO2 are appropriate for ion bombardment processes such as found in plasma etching, as well as high-temperature regrowth steps, this dry lithographic technique is promising for in situ vacuum integrated fabrication.
Niobium trilayer Josephson tunnel junctions with ultrahigh critical current densities
Authors: Miller R. E. , Mallison W. H. , Kleinsasser A. W. , Delin K. A. , Macedo E. M.
Published: July 2002

We describe the fabrication and properties of Nb-AlOx-Nb Josephson tunnel junctions having critical current densities as high as 400 kA/cm2, roughly an order of magnitude larger than any previously reported for this materials system. The quality of the junction characteristics, as indicated by the current level at subgap voltages, is considerably lower in high-Jc than in low-Jc junctions. However, over the entire high-Jc range of 20–400 kA/cm2, the quality of our junctions remains the same (i.e., subgap current scales with critical current).
High-efficiency pyrromethene doped solid-state dye lasers
Authors: Hermes Robert E. , Allik Toomas H. , Chandra Suresh , Hutchinson J. Andrew
Published: July 2002

Successful laser oscillation of various pyrromethene dyes doped in a modified acrylic plastic has been achieved. Pumped with a frequency doubled Nd:YAG laser at 532 nm, a slope efficiency of 85% has been obtained from one of the dyes in plastic, with an output beam energy of 128 mJ. A useful lifetime of greater than 20 000 shots at 3.33 Hz with output energies above 30 mJ has been demonstrated, with only a 34% loss in the available output energy.
Formation of gallium nitride by a novel hot mechanical alloying process
Authors: Millet P. , Calka A. , Williams J. S. , Vantenaar G. J. H.
Published: July 2002

Using a novel ball mill with controlled ball movement and operating at elevated temperature, gallium nitride powder has been synthetized by simple milling of gallium metal in a dry ammonia atmosphere. The structural changes resulting from milling were studied by x-ray diffractometry and transmission electron microscopy. The elemental composition of the as-milled product was analyzed using Rutherford backscattering spectroscopy. A nanostructural phase was obtained following milling, which transforms into polycrystalline GaN of the wurtzite-type structure upon further thermal treatment.
Maskless writing of submicrometer gratings in fused silica by focused ion beam implantation and differential wet etching
Authors: Albert J. , Hill K. O. , Malo B. , Johnson D. C. , Bilodeau F. , Templeton I. M. , Brebner J. L.
Published: July 2002

Surface relief gratings with submicrometer periods have been fabricated in silica by ion implantation with a focused ion beam, followed by etching in diluted hydrofluoric acid. Implanted silica etches three times faster than unimplanted silica and groove depths of the order of 300 nm have been achieved. The method does not require photolithography or masking layers, allows arbitrary patterns to be defined, and may be used to fabricate diffractive optical elements or grating filters in optical waveguides.