bluuebunny/crossref_metadata_2025 huggingface dataset:
Role of IL-18 in Comparison to Serum Creatinine in Early Detection of Sepsis Induced Acute Kidney Injury in Emergency Department in Suez Canal University Hospital
Authors: Mossalem Ahmed Magdi , M. Abdelgeleel Nashwa , Elaal Mohamed Fawzy Abd , Abdelgawad Mohamed Ibrahim , Zeid Ahmed El Sayed Abou
Published: August 2022

Background:  Septic acute kidney injury is a syndrome of acute impairment of function and organ damage linked with long-term adverse outcomes depending on the extent of acute injury superimposed on underlying organ reserve. Sepsis is the most important cause of Acute Kidney Injury (AKI). Interleukin-18 (IL-18) is a pro-inflammatory cytokine expressed in the renal cortex, peritubular capillaries, and interstitium.

Aim: To assess the role of IL-18 in comparison to serum creatinine in the early detection of sepsis-induced acute kidney injury in the Emergency Department (ED) at Suez Canal University Hospital.

Subjects and Methods: A comparative cross-sectional study that included two groups of participants. Study group: patient diagnosed with sepsis-induced acute kidney injury attending to the ED at Suez Canal University Hospital. Control group: healthy individuals of the same age group. Patients were clinically assessed and managed by the ABCDE protocol. All patients were subjected to Initial assessment including History, clinical examination, and laboratory investigation, including urinary IL-8.

Results: Cases had statistically significant higher urinary IL-18 compared to controls (121.97 ± 75.84 vs 69.07 ± 35.59) (p<0.001). IL-18, a value of 69.5 IU/L was found to be the best cut-off point for the prediction of sepsis-induced AKI among cases, with sensitivity = 6 and 5% specificity = 57.5%.

Conclusion: Urinary IL-18 can be used as an early predictor for AKI than serum creatinine in patients presenting with sepsis.
The Entangled Informational Universe
Authors: Denis Olivier
Published: August 2022

From the perspective of quantum gravity research, since the archetypal quantum gravitational object, the black hole, was accidentally found function as a thermodynamic system, it is certainly natural to suggest that the secret of quantum gravity may lie in thermodynamic analysis. Until now, it was not possible to express the gravitational fine-grained entropy of a black hole using the rules of gravity. However, the black holes entropic information formula fills this gap by allowing a semi-classical gravitational approach to express the gravitational fine-grained entropy of black hole. The black holes entropic information formula calculates the entropy of Hawking radiation as the entangled information of the initial considered black hole, this down to the quantum level of the system, the degrees of freedom describing the black hole, and this independently of the Bekenstein-Hawking entropy area law, providing a sufficient microscopic description of how this entropy arises, showing that the process of black holes evaporation is consistent with the unitarity principle. Also, this approach avoids ultraviolet divergences. These perspectives must be understood like the fine-grained entropy formulas discovered by Ryu and Takayanagi. In fact, the black hole entropy turns out to be a special case of the Ryu-Takayanagi conjecture. The Ryu-Takayanagi formula being a general formula for the fine-grained entropy of gravity-coupled quantum systems. That put the accent on the emergence quantum gravity process through the fundamentality of the entangled quantum information.
UMA FLOR CHAMADA DESEJO: o Brasil e o poder na Língua Portuguesa
Authors: Santos Vieira de Jesus Diego
Published: August 2022

O objetivo deste artigo é examinar a decisão brasileira de fortalecer a cooperação com Estados de Língua Portuguesa a partir da década de 1990. O argumento central aponta que os objetivos do Brasil eram racionalizar o exercício de seu poder sobre áreas do mundo em desenvolvimento e ampliar sua oportunidade de voz em fóruns multilaterais e nas negociações com blocos regionais, como a União Europeia. PALAVRAS-CHAVE: Brasil, política externa, Comunidade dos Países de Língua Portuguesa, relações internacionais.A FLOWER CALLED DESIRE: Brazil and power in Portuguese Language Diego Santos Vieira de Jesus This paper aims at analyzing the Brazilian decision of strengthening the cooperation with other Portuguese speaking countries from the 1990s on. The central argument points out that Brazil aimed at rationalizing the exercise of its power over areas under development and expanding the opportunity of being heard in multilateral forums and in the negotiations with regional blocs, as for example with the European Union. KEYWORDS: Brazil, foreign policy, Community of Portuguese Speaking Countries, international relations.UNE FLEUR APPELÉE DÉSIR: le Brésil et la force de la Portuguese Language Diego Santos Vieira de Jesus Le but de cet article est d’analyser la décision prise par le Brésil de renforcer la coopération avec les autres pays lusophones à partir des années 1990. Il y est montré que les objectifs du Brésil étaient de rationaliser l’exercice de son pouvoir sur les régions du monde en développement et d’avoir l’occasion de mieux se faire entendre dans les réunions multilatérales ainsi qu’au sein des négociations avec les blocs régionaux tel que l’Union européenne. MOTS-CLÉS: Brésil, politique étrangère, Communauté des pays de langue portugaise,relations internationales. Publicação Online do Caderno CRH: http://www.cadernocrh.ufba.br   Publicação Online do Caderno CRH no Scielo: http://www.scielo.br/ccrh
CÓDIGO FLORESTAL, FUNÇÃO SOCIOAMBIENTAL DA TERRA E SOBERANIA ALIMENTAR
Authors: Sauer Sérgio N , França Franciney Carreiro de
Published: August 2022

O presente artigo tem como objetivo discutir alterações do Código Florestal, especialmente as propostas de mudanças nas noções de Reserva Legal e Área de Preservação Permanente (APP), em processo de rediscussão no Congresso, após sanção presidencial com vetos no texto aprovado na Câmara em 25 de abril de 2012. Para suprir lacunas da nova Lei, o Executivo Federal editou a Medida Provisória (MP) 571/2012, que retoma a discussão da matéria. Tanto dispositivos da nova Lei como alterações propostas ao texto da MP geram insegurança alimentar e visam a eliminar a função socioambiental da terra. A motivação das mudanças não está relacionada à sustentabilidade ambiental ou às mudanças climáticas, temas fundamentais na agenda mundial, mas parte do princípio de que a natureza é um empecilho ao desenvolvimento. Este artigo resgata as principais alterações no Código Florestal relacionadas à Reserva Legal e às APPs, estabelecendo relações (impactos negativos) com a função socioambiental da terra e a soberania alimentar.PALAVRAS-CHAVE: Código ambiental, função socioambiental da terra, segurança alimentar, sustentabilidadePublicação Online do Caderno CRH: http://www.cadernocrh.ufba.brPublicação Online do Caderno CRH no Scielo: http://www.scielo.br/ccrh
Structural analysis and comparison of the C‐terminal transport signal domains of hemolysin A and leukotoxin A
Authors: Yin Ya , Zhang Fang , Ling Victor , Arrowsmith Cheryl H.
Published: July 2002

NMR spectroscopy was used to study the structure of the C‐terminal signal sequences of the bacterial toxins, hemolysin A(HlyA) and leukotoxin A (LktA). The two signals share little sequence homology; however, both can direct toxin transport with equal efficiency. We report here that in a membrane mimetic environment both peptides form two short non‐interacting α‐helices separated by a short loop. This higher order structure may be a common feature of C‐terminal signals and may be required for interaction with the membrane associated transporter complex.
Ultrafast excitation dynamics of low energy pigments in reconstituted peripheral light‐harvesting complexes of photosystem I
Authors: Melkozernov Alexander N. , Lin Su , Schmid Volkmar H.R. , Paulsen Harald , Schmidt Gregory W. , Blankenship Robert E.
Published: July 2002

Ultrafast dynamics of a reconstituted Lhca4 subunit from the peripheral LHCI‐730 antenna of photosystem I of higher plants were probed by femtosecond absorption spectroscopy at 77 K. Intramonomeric energy transfer from chlorophyll (Chl) b to Chl a and energy equilibration between Chl a molecules observed on the subpicosecond time scale are largely similar to subpicosecond energy equilibration processes within LHCII monomers. However, a 5 ps equilibration process in Lhca4 involves unique low energy Chls in LHCI absorbing at 705 nm. These pigments localize the excitation both in the Lhca4 subunit and in LHCI‐730 heterodimers. An additional 30–50 ps equilibration process involving red pigments of Lhca4 in the heterodimer, observed by transient absorption and picosecond fluorescence spectroscopy, was ascribed to intersubunit energy transfer.
Interaction of fMet‐tRNAfMet with the C‐terminal domain of translational initiation factor IF2 from Bacillus stearothermophilus
Authors: Krafft Christoph , Diehl Annette , Laettig Stefan , Behlke Joachim , Heinemann Udo , Pon Cynthia L. , Gualerzi Claudio O. , Welfle Heinz
Published: July 2002

Analytical ultracentrifugation studies indicated that the C‐terminal domains of IF2 comprising amino acid residues 520–741 (IF2 C) and 632–741 (IF2 C‐2) bind fMet‐tRNA with similar affinities (K
d at 25°C equal to 0.27 and 0.23 μM, respectively). Complex formation between fMet‐tRNAfMet and IF2 C or IF2 C‐2 is accompanied by barely detectable spectral changes as demonstrated by a comparison of the Raman spectra of the complexes with the calculated sum of the spectra of the individual components. These results and the temperature dependence of the K
d of the protein–RNA complexes indicate that complex formation is not accompanied by obvious conformational changes of the components, and possibly depends on a rather small binding site comprising only a few interacting residues of both components.
Significant change in the structure of a ribozyme upon introduction of a phosphorothioate linkage at P9: NMR reveals a conformational fluctuation in the core region of a hammerhead ribozyme
Authors: Suzumura Ken-ichi , Warashina Masaki , Yoshinari Koichi , Tanaka Yoshiyuki , Kuwabara Tomoko , Orita Masaya , Taira Kazunari
Published: July 2002

A modified hammerhead ribozyme (R32S) with a phosphorothioate linkage between G8 and A9, a site that is considered to play a crucial role in catalysis, was examined by high‐resolution 1H and 31P nuclear magnetic resonance (NMR) spectroscopy. Signals due to imino protons that corresponded to stems were observed, but the anticipated signals due to imino protons adjacent to the phosphorothioate linkage were not detected and the 31P signal due to the phosphorothioate linkage was also absent irrespective of the presence or absence of the substrate. 31P NMR is known to reflect backbone mobility, and thus the absence of signals indicated that the introduction of sulfur at P9 had increased the mobility of the backbone near the phosphorothioate linkage. The addition of metal ions did not regenerate the signals that had disappeared, a result that implied that the structure of the core region of the hammerhead ribozyme had fluctuated even in the presence of metal ions. Furthermore, kinetic analysis suggested that most of the R32S–substrate complexes generated in the absence of Mg2+ ions were still in an inactive form and that Mg2+ ions induced a further conformational change that converted such complexes to an activated state. Finally, according to available NMR studies, signals due to the imino protons of the central core region that includes the P9 metal binding site were broadened or not observed, suggesting that this catalytically important region might be intrinsically flexible. Our present analysis revealed a significant change in the structure of the ribozyme upon the introduction of the single phosphorothioate linkage at P9 that is in general considered to be a conservative modification.
Evidence that 3′‐phosphorylated polyphosphoinositides are generated at the nuclear surface: use of immunostaining technique with monoclonal antibodies specific for PI 3,4‐P2
Authors: Yokogawa Tohei , Nagata Satoshi , Nishio Yuichiro , Tsutsumi Tomoaki , Ihara Sayoko , Shirai Ryuichi , Morita Koji , Umeda Masato , Shirai Yasuhito , Saitoh Naoaki , Fukui Yasuhisa
Published: July 2002

Phosphatidylinositol (PI) 3,4‐P2 is a phosphoinositide that has been shown to be important for signal transduction in growth factor stimulation. We have produced monoclonal antibodies specific for PI 3,4‐P2, which were able to detect PI 3,4‐P2 generated in 293T cells treated with H2O2, or in MKN45/BD110 cells expressing activated PI 3‐kinase in immunostaining. Prolonged treatment with 0.05% Tween 20 resulted in detection of staining not only at the plasma membrane, but also at the nuclear surface, indicating that 3′‐phosphorylated phosphoinositides can be generated and function in the nucleus.
Development and application of cytotoxic T lymphocyte‐associated antigen 4 as a protein scaffold for the generation of novel binding ligands
Authors: Hufton Simon E. , van Neer Nicole , van den Beuken Twan , Desmet Johan , Sablon Erwin , Hoogenboom Hennie R.
Published: July 2002

We have explored the possibilities of using human cytotoxic T lymphocyte‐associated antigen 4 (CTLA‐4) as a single immunoglobulin fold‐based scaffold for the generation of novel binding ligands. To obtain a suitable protein library selection system, the extracellular domain of CTLA‐4 was first displayed on the surface of a filamentous phage as a fusion product of the phage coat protein p3. CTLA‐4 was shown to be functionally intact by binding to its natural ligands B7‐1 (CD80) and B7‐2 (CD86) both in vitro and in situ. Secondly, the complementarity determining region 3 (CDR3) loop of the CTLA‐4 extracellular domain was evaluated as a permissive site. We replaced the nine amino acid CDR3‐like loop of CTLA‐4 with the sequence XXX‐RGD‐XXX (where X represents any amino acid). Using phage display we selected several CTLA‐4‐based variants capable of binding to human αvβ3 integrin, one of which showed binding to integrins in situ. To explore the construction of bispecific molecules we also evaluated one other potential permissive site diametrically opposite the natural CDR‐like loops, which was found to be tolerant of peptide insertion. Our data suggest that CTLA‐4 is a suitable human scaffold for engineering single‐domain molecules with one or possibly more binding specificities.
Stimulation of Cdx1 by oncogenic β‐catenin/Tcf4 in colon cancer cells; opposite effect of the CDX2 homeoprotein
Authors: Domon-Dell Claire , Freund Jean-Noël
Published: July 2002

The homeobox gene Cdx1 is a regulator of intestinal epithelial cell proliferation and differentiation. Using a transfection approach, we showed here that the oncogenic activation of the β‐catenin pathway stimulates the endogenous expression of the Cdx1 mRNA as well as the activity of the Cdx1 promoter in cancer cells of the human colon. Reciprocally, the paralogue homeobox gene Cdx2 exerts an inhibitory effect on the basal and on the β‐catenin‐stimulated activity of the Cdx1 promoter. The inhibitory effect of CDX2 requires the intact homeodomain. It is not dependent on canonical CDX binding sites in the Cdx1 promoter nor on the cis‐elements specifically targeted by the β‐catenin/Tcf complex. We conclude that the oncogenically activated β‐catenin and CDX2 have opposite and independent effects on the Cdx1 homeobox gene.
Apoptosis‐induced concomitant release of cytosolic proteins and factors which prevent cell death
Authors: Endrich Michael M , Grossenbacher Doris , Geistlich Andreas , Gehring Heinz
Published: July 2002

Summry— In the course of the apoptotic cell death, cells fragment into apoptotic bodies, the elimination of which by phagocytosis is thought to avoid the release of cytosolic constituents whose occurrence is indicative for necrotic cell death. Confluent cultures of chicken embryo fibroblasts, however, show a different behaviour. After serum deprivation, they transiently released with the same time course mitogenic activity, lactate dehydrogenase and cytosolic peptidyl prolyl cis‐trans isomerases into the serum‐free culture medium. The release correlated in time with a decrease of the cell number which started ∼3 h after serum removal and ceased within ∼10 h at about half of the initial cell density. Morphological features like cell shrinkage, membrane blebbing and cell fragmentation as well as internucleosomal DNA fragmentation indicated apoptotic cell death whereas necrotic cell death could be excluded. Conditioned medium (Mr ≥ 30 kDa) from serum‐deprived cultures of chicken embryo fibroblasts completely prevented chicken embryo fibroblasts to undergo apoptosis as did phorbol 12‐myristate, 13‐acetate and, to ∼60%, L‐cysteine. Cycloheximide had no effect on serum deprivation‐induced apoptosis. From the present results it can be concluded that chicken embryo fibroblasts and possibly other cells undergoing apoptosis release cytosolic components and endogenous survival factor(s) which prevent apoptosis.
Cybernetic Model for the Growth of Saccharomycescerevisiae on Melibiose
Authors: Gadgil Chetan J. , Bhat P. J. , Venkatesh K. V.
Published: July 2002

Cybernetic modeling has traditionally been used in the modeling of microbial growth on multiple substrates. In this paper, cybernetic modeling has been applied to serve as a model for growth on substrates such as melibiose, which are disaccharides and enzymatically degrade to a monosaccharide mixture in the fermentation broth. The enzyme α‐galactosidase has been shown to be strongly induced in the presence of galactose and severely repressed by glucose. In the present model, the relative concentration of α‐galactosidase has been linked to that of the key enzyme for galactose metabolism. The enzymatic degradation process is placed under the control of the cybernetic variables. The maximum rate of melibiose degradation vm and the Monod parameters for growth of Saccharomyces cerevisiae on pure glucose and galactose were estimated by batch growth experiments. S. cerevisiae growth on melibiose and a mixture of melibiose and glucose under a variety of preculturing conditions was simulated. Depending on the rate of enzymatic degradation (i.e., the value of vm), the cell mass profile for microbial growth on a disaccharide can resemble profiles for growth on a single substrate (melibiose) or can resemble diauxie growth. Experiments indicate that the model is able to accurately predict the cell mass profiles for yeast growth.
How Is Enzymatic Selectivity of Menthol Esterification Catalyzed by Surfactant‐Coated Lipase Determined in Organic Media?
Authors: Kamiya Noriho , Goto Masahiro
Published: July 2002

A kinetic study of menthol esterification reaction catalyzed by surfactant‐coated lipase (from Candida rugosa) has been conducted in dry isooctane. The kinetic characteristics observed in the enantioselective esterification of menthol with lauric acid (C12) was found to conform to a ping‐pong bi−bi mechanism with dead‐end inhibition by excess menthol. According to the mechanism we determined the maximum reaction velocity (Vmax), Michaelis constants (Km(fatty acid) and Km(menthol)), and the inhibition constant (Ki) . Results have shown that the constant values Km and Ki of (+) ‐menthol are comparable with the corresponding values of the (−) ‐isomer. However, there was significant difference in the Vmax values between the two enantiomers; the Vmax involving the (−) ‐isomer was a 100‐fold faster than that of the (+) ‐isomer. The results suggest that the lipase should recognize the chirality of menthol molecule not in the binding process to the hydrophobic pocket of the lipase but in the nucleophilic attack of the OH group in (−) ‐menthol. To assess the substrate specificity of C. rugosa lipase for carboxylic acids, the effect of fatty acids of varying chain lengths (C14, C16) on esterification kinetics have been studied using the (−) ‐menthol. We found that fatty acids exhibit different Km values, whereas their Vmax values are invariably similar. The results have indicated that the catalytic activity of the surfactant‐coated lipase for different fatty acid largely depends on the binding behavior of a fatty acid to the active site of the coated enzyme and this action is independent of the acylation step of the (−) ‐isomer by an acyl−enzyme intermediate.
Flux Calculation Using Metabolic Control Constraints
Authors: Liao James C. , Delgado Javier
Published: July 2002

Prediction of metabolic fluxes requires the knowledge of reaction stoichiometry and the overall reaction kinetics including various regulatory mechanisms. Lacking the complete reaction kinetics, one often uses available flux measurements or other constraints to calculate the intracellular fluxes. In this article, we show that the flux constraints derived from the dynamic metabolic control theory can be used instead of the kinetics to calculate the fluxes. This approach provides a possibility of predicting the flux distribution in a genetically modified organism using the flux control coefficients and the fluxes determined from the host or the parent strains. It shows that the regulatory constraints can be expressed in terms of the flux control coefficients. This result gives new significance to the flux control coefficients and provides new incentives to determine the flux control coefficients systematically.
Positive skin and oral challenge responses to potato and occurrence of immunoglobulin E antibodies to patatin (Sol t 1) in infants with atopic dermatitis
Authors: Majamaa Heli , Seppälä Ulla , Palosuo Timo , Turjanmaa Kristiina , Kalkkinen Nisse , Reunala Timo
Published: July 2002

The clinical significance and molecular specificity of hypersensitivity reactions to raw and cooked potatoes remain ambiguous. We therefore investigated the clinical hypersensitivity to raw and cooked potato in infants suspected to have potato allergy and compared the findings with the occurrence of immunoglobulin E (IgE) antibodies to patatin (Sol t 1), characterized as the primary allergen of potato. Twelve infants (10 to 24 months of age) suffering from atopic dermatitis (AD) and suspected to have adverse reactions to potato, were examined. As a skin exposure test we used rubbing with both raw and cooked potato, and used open oral challenge with cooked potato for 7 days. A special eczema scoring system (SCORAD) was used to assess the severity of symptoms and signs of AD. Skin‐prick tests (SPTs) were performed with raw potato and natural Sol t 1, and serological studies included measurement of total serum IgE and IgE antibodies to Sol t 1, and potato radioallergosorbent testing (RAST). The skin‐rubbing test with raw potato was positive in seven (58%) and the oral challenge positive in eight (67%) infants. One infant presented with an immediate reaction and seven with a delayed reaction, i.e. exacerbation of AD, after oral challenge responses to cooked potato. Nine (75%) infants had IgE antibodies to Sol t 1 in enzyme‐linked immunosorbent assay (ELISA), and SPT to natural Sol t 1 was positive in six (50%) potato‐allergic infants. In conclusion, we observed positive challenge responses to both raw and cooked potato in food‐allergic atopic infants. The presence of IgE antibodies and concomitant positive SPTs to the heat‐stable potato allergen, Sol t 1, suggest that cooked potato can be an allergenic food for infants suffering from AD.
Left ventricular function in young adults with childhood and adulthood onset growth hormone deficiency
Authors: Longobardi Salvatore , Cuocolo Alberto , Merola Bartolomeo , Di Rella Francesca , Colao Annamaria , Nicolai Emanuele , Cardei Stefania , Salvatore Marco , Lombardi Gaetano
Published: July 2002

OBJECTIVE

The impairment of heart structure and function in adults with childhood onset GH deficiency has been recently described. However, previous echocardiographic studies have reported no differences in cardiac mass and function between adulthood onset GH deficient patients and healthy subjects.

DESIGN

The aim of this study was to evaluate cardiac performance in adult patients with childhood and adulthood onset GH deficiency, using equilibrium radionuclide angiography, a method more accurate than echocardiography.

PATIENTS

Eleven patients with childhood onset GH deficiency, 9 patients with adulthood onset GH deficiency and 12 age‐, gender‐, height‐ and weight‐matched healthy subjects entered the study.

MEASUREMENTS

All the study population underwent equilibrium radionuclide angiography at rest and during physical exercise.

RESULTS

Both childhood and adulthood onset GH deficient patients had an impaired left ventricular systolic performance both at rest (ejection fraction was 55 ± 6%, 55 ± 10% and 66 ± 6% in childhood and adulthood onset GH deficient patients and control group, respectively;P < 0.0001) and during physical exercise (ejection fraction was 54 ± 9% in childhood onset GH deficient patients, 53 ± 9% in adulthood onset GH deficient patients and 76 ± 7% in normal subjects;P < 0.0001). Peak ejection rate was 3.2 ± 0.8 end‐diastolic volume/second, 3.0 ± 0.6 end‐diastolic volume/second and 3.9 ± 0.8 end‐diastolic volume/second in childhood and adulthood onset GH deficient patients and control group, respectively (P < 0.01). Exercise‐induced changes in end‐systolic volume were increased in both groups of patients compared with healthy subjects. In contrast, exercise‐induced end‐diastolic volume changes were not different between GH deficient patients and controls. Resting peak filling rate was 2.6 ± 0.7 end‐diastolic volume/second, 2.5 ± 0.7 end‐diastolic volume/second and 3.1 ± 0.3 end‐diastolic volume/second in the 2 groups of patients and healthy subjects, respectively (P < 0.05). Reduced exercise tolerance in all patients, as shown by the significantly lower values of peak workload (P < 0.0001), peak rate‐pressure product (P < 0.01) and exercise duration (P < 0.0001) was observed.

CONCLUSION

Patients affected by GH deficiency have left ventricular systolic dysfunction at rest and during physical exercise, suggesting that GH plays a physiological role in maintaining normal cardiac performance in humans. Furthermore, no difference between childhood and adulthood onset GH deficient patients was found indicating that both group of patients have an impairment of cardiac function.
Role of the mukB gene in chromosome and plasmid partition in Escherichia coli
Authors: Weitao Tao , Dasgupta Santanu , Nordström Kurt
Published: July 2002

The intracellular locations of oriC and oriR1, the replication origins of the chromosome and plasmid R1, respectively, were visualized by fluorescence in situ hybridization (FISH) in exponentially growing populations of Escherichia coli. The locations of oriC and oriR1 (from a Par+ R1 plasmid) were unique and different in the wild‐type host. In a mukB mutant, the positions were perturbed for both origins. The position of oriR1 from a plasmid with active partition (Par+) in the mukB host was as randomized as that of oriR1 from the Par− plasmid in a wild‐type host. However, this mukB‐induced randomization did not result in unstable inheritance of the Par+ plasmid, as measured by the conventional segregation assay. This might result from the preferential association of the Par+ plasmid with the bigger, decondensed nucleoid‐containing daughters during cell division of MukB− cells, whereas the Par− plasmids were distributed at random and were lost by frequently ending up in anucleate cells.
Vaginal births after Caesarean (VBAC): a population study
Authors: Stone C. , Halliday J. , Lumley J. , Brennecke S.
Published: July 2002

This paper describes delivery outcomes for women from Victoria, Australia, who gave birth in 1995 and whose immediately previous (penultimate) delivery, within a 5‐year search period, was a Caesarean section. Because of the large numbers of records involved, dedicated computer software for record linkage was used to identify the previous delivery and link it with the woman’s current birth in 1995. Overall, 79% of the records from multiparous women were linked successfully. Approximately 15% were not linked because the previous birth was before the search period or was an abortion that would not have been reported to the Perinatal Data Collection Unit. Reasons for not being able to link the last 6% of the records include the previous pregnancy being overseas or interstate. Women who had a vaginal birth as the penultimate birth or a multiple birth at either event were excluded, resulting in a study population of 4663 linked records. More women (68%) had a repeat Caesarean than went into labour and, of the remaining women who laboured, 56% delivered vaginally. Overall, 18% of the women delivered vaginally. For the women who went into labour, the reported number experiencing a uterine rupture was two per 1000 births. Uterine rupture was not reported in the two‐thirds who did not labour but had a repeat Caesarean. A review of the perinatal deaths identified only two deaths, one baby being born by elective Caesarean and one by a vaginal birth after a previous Caesarean (VBAC) where the choice of delivery methods may have contributed to the death. This large study is one of the few in the literature to provide population‐based information on vaginal births after a previous Caesarean and related outcomes.
Review: Relaxin Expressed at the Feto–Maternal Interface
Authors: Klonisch T , Hombach‐Klonisch S
Published: July 2002

Contents

The placental expression of relaxin, a member of the insulin‐like family, has been studied in the placenta in various species with different histological types of materno‐fetal interdigitation and trophoblast invasiveness. Placental relaxin expression in these species showed some common features. Relaxin was present in placental areas of intense feto‐maternal nutrition‐ and gas‐exchange and high growth potential, implicating relaxin to be involved in placental metabolism and placental growth. Differentiation of trophoblast cells along various lineage pathways affected relaxin gene activity and an inverse expression pattern of relaxin and MHC class I molecules was observed in equine pseudostratified trophoblast cells. A fall in peripheral plasma concentrations of relaxin prior to abortion appears to indicate impaired materno‐fetal interdigitation which results in insufficient placentation.
X‐ray elemental analysis differentiates blood vessels and lymphatic vessels in the chick choroid
Authors: Junghans B M , Wadley R B , Crewther S G , Crewther D P
Published: July 2002

Purpose: Chick choroidal lymphatics swell rapidly during recovery from form‐deprivation occlusion, leading to the question of functional significance. To date, analysis of lymph in initial lymphatics has been problematic because of the difficulties of access. However, elemental composition can be determined using scanning electron microscope (SEM) X‐ray microanalysis. This study investigated whether cryo‐fixation would permit vascular fluids to be analysed in situ.

Methods: Two chicks were raised normally and seven were raised with monocular occlusion for 12 days before varying periods of normal visual experience. The eyes were rapidly frozen, fractured and X‐ray spectra obtained from the lumina of lymphatic and blood vessels in a Cambridge S360 SEM.

Results: The elemental signatures of Na/Cl/K/P/S distinguished the two vessel types.

Conclusions: These results suggest this bulk‐frozen tissue technique can quantify relative changes in elemental species present in various ocular compartments in response to light‐induced changes in the retina.
Does cortical motion adaptation exhibit functional properties analogous to light adaptation in the retina?
Authors: Clifford Colin W G , Wenderoth Peter
Published: July 2002

Purpose: The retina codes variations in luminance by adapting to and hence discounting, the mean luminance. During adaptation to a moving pattern, perceived speed decreases. Thus we know that the adapted visual system does not simply code the absolute speed of a stimulus. We hypothesize that adaptation to a moving stimulus serves to optimize coding of changes in speed at the expense of maintaining an accurate representation of absolute speed. In this case we would expect discrimination of speeds around the adapted level to be preserved or enhanced by motion adaptation.

Methods and results: After adaptation to motion in the same direction as a subsequent test stimulus, seven of eight subjects showed a reduction of perceived speed in the adapted region and seven showed enhanced discrimination.

Conclusions: We conclude that motion adaptation preserves or enhances differential speed sensitivity at the expense of an accurate representation of absolute speed in a manner analogous to retinal light adaptation.
Pseudo‐Kaposi’s sarcoma: The association of arterio‐venous malformations with skin lesions resembling Kaposi’s sarcoma
Authors: Smiddy Pf , Molloy Mp , Flanagan N , Barnes L
Published: July 2002

A patient is described with skin lesions resembling Kaposi’s sarcoma (KS). Arteriography revealed multiple arteriovenous malformations in the affected limb. This condition has been termed pseudo‐Kaposi’s sarcoma. Although reports of this condition have appeared in dermatological journals, as yet we are unaware of any account in the radiological literature. This paper presents a case and reviews the literature. In suspected cases of KS in which the history or clinical features are atypical, this unusual condition should be considered and a search made for the diagnostic vascular lesions.
Localization of small ovarian Sertoli–Leydig cell tumors by transvaginal sonography with color Doppler
Authors: Yanushpolsky E. H. , Brown D. L. , Smith B. L.
Published: July 2002

Color Doppler ultrasound is a non‐invasive diagnostic modality that has been gaining popularity in the evaluation of gynecological tumors. It demonstrates blood flow in a visually familiar way, and facilitates detection of neovascularity in pelvic tumors. In this article we describe, for the first time, a case in which a small androgen‐producing ovarian tumor was localized by color Doppler ultrasound after other non‐invasive imaging techniques failed. Copyright © 1995 International Society of Ultrasound in Obstetrics and Gynecology
Developmental Expression Pattern of the Myelin ProteolipiMAL Indicates Different Functions of MAL for Immature Schwann Cells and in a Late Step of CNS Myelinogenesis
Authors: Frank Marcus , Schaeren‐Wiemers Nicole , Schneider Regula , Schwab Martin E.
Published: July 2002

Abstract : The myelin and lymphocyte protein MAL is a small proteolipid of 17 kDa and is expressed by oligodendrocytes and Schwann cells. We have characterized the embryonic and postnatal expression of MAL in the rat nervous system by in situ hybridization, immunocytochemistry, and western blotting and compared it with that of other myelin constituents. In the CNS, MAL is expressed during late steps of myelination : MAL protein appears ~3‐5 days later than myelin basic protein and proteolipid protein. In contrast, in the PNS, MAL transcript and protein expression is detected prior to the onset of myelination, as early as embryonic day 17. Our results demonstrate that MAL is differentially expressed in oligodendrocytes and Schwann cells, likely reflecting different functions of the MAL proteolipid : (1) The late expression of MAL protein in the CNS points to a role in the final steps of myelin sheath formation, such as stabilization of the compacted myelin membranes. (2) The early expression of MAL protein in immature Schwann cells suggests an important role of MAL in the terminal differentiation step of the Schwann cell lineage and in the onset of peripheral myelination.
Flowering Frequency and Plant Performance and their Relation to Age in the Perennial Orchid Spiranthes spiralis (L.) Chevall.
Authors: Willems J. H. , Dorland E.
Published: July 2002

Abstract: Long‐term demographic data have been analyzed to establish possible costs of flowering in the terrestrial orchid Spiranthes spiralis (L.) Chevall. in The Netherlands. Costs of flowering can be expressed as individual plant performance and flowering frequency in relation to the generative or vegetative status in the following year. Flowering in individuals of S. spiralis in a given year (t) is followed by a non‐flowering phase in the next growing season (t + 1) in more than 80 % of the plants. The decline in flowering frequency is not a result of the age structure of the population involved because individual plants do not show signs of senescence after 10 ‐ 15 years of aerial presence as an autotrophic plant. Rosettes have a smaller leaf area in the year of flowering (t), compared to the previous (t ‐ 1) and following year (t + 1), due to the allocation of the limited underground resources to both flowering stalk and rosette at the beginning of its growing season. Generative reproduction in S. spiralis has a significant negative impact on both flowering frequency in subsequent years and on rosette size in the year of flowering. The flowering frequency and rosette size in relation to the life history, characterized by the yearly replacement of the underground tuber, is discussed. Better understanding of the life‐history strategy, including costs of reproduction, may contribute to the creation of sustainable environmental conditions for growth of S. spiralis, e.g., optimal conditions for photosynthesis during the aboveground stage of the tiny wintergreen rosettes.
Passivation of high T
c superconductor surfaces with CaF2 and Bi, Al, and Si oxides
Authors: Hill D. M. , Meyer H. M. , Weaver J. H. , Nelson D. L.
Published: July 2002

X-ray photoelectron spectroscopy has been used to investigate passivation of the high-temperature superconductors YBa2Cu3O7−x and Bi2Ca1+xSr2−xCu2O8+y involving overlayer materials deposited in vacuum onto freshly cleaved surfaces. CaF2 was found to be completely inert and to form uniform overlayers on the surface. Deposition of Bi, Si, and Al in activated oxygen produced oxides and exhibited minimal reaction and disruption of the superconductor surface. In contrast, results for Bi, Si, and Al deposition in nonactivated oxygen or ultrahigh vacuum showed extensive substrate disruption due to surface reactions and oxygen withdrawal. This indicates that the activation technique provides oxygen from the gas phase for oxide formation and facilitates nondisruptive overlayer growth, even for reactive metals.
Ultraviolet optical parametric oscillation in β-BaB2O4
Authors: Bosenberg W. R. , Cheng L. K. , Tang C. L.
Published: July 2002

We report the operation of a β-BaB2O4 singly resonant optical parametric oscillator broadly tunable in the ultraviolet, visible, and infrared regions of the spectrum. This optical parametric oscillator was pumped at 266 nm and was continously tunable throughout 0.33–1.37 μm. A novel cavity design was implemented which has applicability to other parametric oscillators. The oscillation threshold of this device was measured and compared to the calculated result.
Thermochromic sputter-deposited vanadium oxyfluoride coatings with low luminous absorptance
Authors: Khan K. A. , Granqvist C. G.
Published: July 2002

Thin films of VOxFy were made by rf magnetron sputtering of V in Ar+O2+CF4. They were analyzed by Rutherford backscattering spectrometry and transmission electron microscopy. Optical and electrical properties changed within narrow temperature ranges. These results resemble those of thermochromic VO2, although VOxFy has significantly enhanced transmittance, lowered conductance, and marginally depressed switching temperature.
Formation of a high quality two-dimensional electron gas on cleaved GaAs
Authors: Pfeiffer Loren , West K. W. , Stormer H. L. , Eisenstein J. P. , Baldwin K. W. , Gershoni D. , Spector J.
Published: July 2002

We have succeeded in fabricating a two-dimensional electron gas (2DEG) on the cleaved (110) edge of a GaAs wafer by molecular beam epitaxy (MBE). A (100) wafer previously prepared by MBE growth is reinstalled in the MBE chamber so that an in situ cleave exposes a fresh (110) GaAs edge for further MBE overgrowth. A sequence of Si-doped AlGaAs layers completes the modulation-doped structure at the cleaved edge. Mobilities as high as 6.1×105 cm2/V s are measured in the 2DEG at the cleaved interface.
Photon scanning tunneling microscope study of optical waveguides
Authors: Tsai Din Ping , Jackson Howard E. , Reddick R. C. , Sharp S. H. , Warmack R. J.
Published: July 2002

A novel technique, photon scanning microscopy, is shown to probe directly the evanescent field outside a planar and a channel waveguide. The decay lengths for these evanescent fields were measured and correspond well to the decay lengths of the evanescent fields calculated for each structure. Two-dimensional scanning at constant intensity or constant height reveals lateral variations in these fields due to topographic changes, index of refraction inhomogeneities, or modal variations within the waveguide.
Characterization of LiNbO3 crystals by line-focus-beam acoustic microscopy
Authors: Kushibiki J. , Takahashi H. , Kobayashi T. , Chubachi N.
Published: July 2002

Line-focus-beam (LFB) acoustic microscopy is applied to quantitative characterization of piezoelectric LiNbO3 crystals to demonstrate the usefulness of this new analytical technique. Experimental relations between chemical composition ratios of Li/Nb and leaky surface acoustic wave (LSAW) velocities for 128°YX LiNbO3 wafers are determined. LSAW velocity measurements are carried out for commercial wafers obtained from a series of crystal growths. Small changes of 0.092% are detected due to the compositional variation. It is estimated that the ‘‘effective’’ congruent composition in the production line is 48.440 Li2O mol% with the density of 4647.4 kg/m3.
Formation of amorphous Fe-B alloys by mechanical alloying
Authors: Calka A. , Radlinski A. P.
Published: July 2002

Using a novel ball mill with controlled ball movement we have produced for the first time amorphous Fe50B50 and Fe40B60 alloys and nanocrystalline Fe80B20 and Fe66B34 alloys by mechanical alloying. The structural evolution of elemental powder mixtures is studied following milling and subsequent thermal treatment. Upon heating both amorphous and nanostructural mechanically alloyed Fe-B alloys transform into a mixture of equilibrium phases.
Structural and optical properties of sol-gel-processed BaTiO3 ferroelectric thin films
Authors: Kamalasanan M. N. , Chandra Subhas , Joshi P. C. , Mansingh Abhai
Published: July 2002

BaTiO3 thin films having a perovskite structure were deposited onto stainless steel and fused quartz substrates by sol-gel processing. Crystalline, transparent, and crack-free films of 5000 Å thickness were fabricated by spinning and post-deposition annealing at a temperature of 600 °C. Ferroelectric properties were confirmed by P-E hysteresis loops. The dielectric constant and optical transmission were also measured.
Sputter depth profiling analysis of Ta2O5 on Si without preferential sputtering by energetic oxygen ion beams
Authors: Moon Dae Won , Kim Kyung Joong
Published: July 2002

Preferential sputtering has been one of the major problems in sputter depth profiling. Especially for compounds, preferential sputtering of one component leads to a change in the chemical state of the sample constituents. Therefore, accurate sputter depth profiling of the undistorted chemical state of sample constituents has not been possible. In this letter, we report that the preferential sputtering of oxygen atoms in the depth profiling of a Ta2O5 thin film on Si could be reduced quite successfully by using energetic oxygen ion beams with an appropriate incidence angle (30°) from the surface normal. By choosing an appropriate ion incidence angle, oxidation of the metallic Ta by the incident oxygen ion beams could be avoided as well. It was therefore possible to obtain an essentially undistorted sputter depth profile of the Ta in Ta2O5 on Si.
Electrical properties and formation mechanism of porous silicon carbide
Authors: Konstantinov A. O. , Harris C. I. , Janzén E.
Published: July 2002

Variation of the preparation conditions of porous silicon carbide is shown to have a strong effect on the structural and electrical properties of the material obtained. A correlation has been observed between the fiber size and resistivity of porous SiC, a decrease of fiber size results in a semi-insulating material due to Fermi-level pinning to surface states. A model is proposed for the mechanism of fiber size self-regulation responsible for the porous material formation. The model relates the blocking of the fiber dissolution process to the increase of resistivity in a thin fiber due to Fermi-level pinning. We suggest that the Fermi-level pinning model is also applicable to the formation mechanism of porous silicon.
Minimum detectable displacement in near-field scanning optical microscopy
Authors: Froehlich Fred F. , Milster Tom D.
Published: July 2002

The probe-to-sample separation in near-field scanning optical microscopes can be regulated by a noncontact atomic shear force sensing scheme that allows simultaneous acquisition of optical and shear force images. We have measured the minimum detectable displacement that can be achieved with a scheme based on diffracting a focused laser beam from the vibrating probe. The minimum detectable displacement determines the smallest resolvable change in force acting on the probe. The measured shot-noise-limited value is 2.8×10−3 Årms/√Hz, and the practical sensitivity is limited by thermal vibration noise to 7×10−3 Årms/√Hz. These values compare well with those calculated theoretically.
Electrically active subthreshold damage in Si ion implanted with Si, Ge, and Sn
Authors: Kringho/j P. , Williams J. S. , Jagadish C.
Published: July 2002

The residual damage in Si after Si, Ge, and Sn implantation and annealing at elevated temperatures has been studied with capacitance-voltage measurements and deep level transient spectroscopy. We present a critical dose, specific to the implanted species and energy, below which no electrically active defects are found within our detection limit (2×10−5 of the background doping). This critical dose is found to scale with the number of beam-induced vacancies and is in remarkable agreement with the critical dose established previously for observation of structural defects (dislocation loops) with transmission electron microscopy.
Corona poling of nonlinear polymer thin films for electro-optic modulators
Authors: Hill R. A. , Knoesen A. , Mortazavi M. A.
Published: July 2002

We have developed an experimental technique for corona poling a nonlinear polymer thin film for use in electro-optic modulators. This method eliminates the pinhole and surface roughness damage that has been observed when corona poling a nonlinear polymer deposited on a conducting substrate. Electro-optic modulators have been constructed to compare this corona poling technique to the contact poling technique commonly used with electro-optic devices. Experimental results are presented that demonstrate that the corona poled electro-optic devices were poled with electric fields near the dielectric breakdown of the thin polymer films—fields that are often difficult to achieve with contact poling.
Emission limited injection by thermally assisted tunneling into a trap-free transport polymer
Authors: Abkowitz M. A. , Mizes H. A. , Facci J. S.
Published: July 2002

We have measured the steady-state current supported by a variety of contacts on a polytetraphenylbenzidine hole transport polymer. When glassy carbon is used as a hole injecting contact to the polymer, the current is found to exhibit prototypical emission limited behavior. Unique features of the electric field and temperature dependence of the emission limited current cannot be explained by injection theories appropriate to conventional band type semiconductors. A model of thermally assisted tunneling from carriers at the Fermi level of the contact to localized states in the polymer has been formulated. This model is able to critically account for key features in the experimental data.