bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effect of Hypericum perforatum on marble‐burying by mice
Authors: Skalisz L. L. , Beijamini V. , Andreatini R. 
Published: May 2004

AbstractThe effect of Hypericum perforatum extract (LI 160) at a dose that exerts an antidepressive‐like effect was studied in mice in the marble‐burying test. Acute Hypericum perforatum (150, 300 and 500 mg/kg, p.o.) reduced immobility time in the forced swimming test. The number of marbles buried, but not locomotor activity, was reduced by acute treatment with Hypericum perforatum (150 and 300 mg/kg, p.o.). However, this effect was not seen after chronic treatment (21 days) with Hypericum perforatum (300 mg/kg, p.o.). Thus, Hypericum perforatum extract, at antidepressant dose, exerts an acute anxiolytic drug effect on the marble‐burying test, which could indicate a potential anti‐obsessive effect, although the development of tolerance could be an important drawback. Copyright © 2004 John Wiley & Sons, Ltd.
Identifying several biased coins encountered by a hidden random walk
Authors: Levin David A. , Peres Yuval 
Published: May 2004

AbstractSuppose that attached to each site z ∈ ℤ is a coin with bias θ(z), and only finitely many of these coins have nonzero bias. Allow a simple random walker to generate observations by tossing, at each move, the coin attached to its current position. Then we can determine the biases {θ(z)}z∈ℤ, using only the outcomes of these coin tosses and no information about the path of the random walker, up to a shift and reflection of ℤ. This generalizes a result of Harris and Keane. © 2004 Wiley Periodicals, Inc. Random Struct. Alg., 2004
Data structures for maintaining set partitions
Authors: Bender Michael A. , Sethia Saurabh , Skiena Steven S. 
Published: May 2004

AbstractEfficiently maintaining the partition induced by a set of features is an important problem in building decision‐tree classifiers. In order to identify a small set of discriminating features, we need the capability of efficiently adding and removing specific features and determining the effect of these changes on the induced classification or partition. In this paper we introduce a variety of randomized and deterministic data structures to support these operations on both general and geometrically induced set partitions. We give both Monte Carlo and Las Vegas data structures that realize near‐optimal time bounds and are practical to implement. We then provide a faster solution to this problem in the geometric setting. Finally, we present a data structure that efficiently estimates the number of partitions separating elements. © 2004 Wiley Periodicals, Inc. Random Struct. Alg., 2004
All five digits of the hands of fetuses with Down syndrome are short
Authors: Maymon R. , Tovbin Y. , Dreazen E. , Weinraub Z. , Herman A. 
Published: May 2004

AbstractObjectiveTo compare mid‐gestation sonographic measurements of all five digits of the hands of fetuses with Down syndrome with those of normal controls.MethodsTwenty‐nine fetuses between 17 and 26 weeks' gestation which had been confirmed by karyotyping to have Down syndrome were included in this prospective study. Each fetus was scanned once and the digits of only one hand were measured. Measurements were compared with those of 302 previously reported normal controls matched for gestational age. All measurements were expressed in multiples of the gestation‐specific normal median (MoM) for each digit.ResultsCompared to 1 MoM for the length of Digits 1 to 5 from the normal population, the respective values in the Down syndrome digits were: 0.94, 0.85, 0.92, 0.88 and 0.85 MoM, representing values significantly lower than normal (P < 0.05; t‐test).ConclusionsAll five digits of the hands of fetuses with Down syndrome are shorter than are those of euploid fetuses. Integration of fetal digit measurement into the antenatal assessment of selected high‐risk cases may be of value although confirmation of our findings should be obtained before this measurement is incorporated into Down syndrome screening in the general population. Copyright © 2004 ISUOG. Published by John Wiley & Sons, Ltd.
Maxillary length at 11–14 weeks of gestation in fetuses with trisomy 21
Authors: Cicero S. , Curcio P. , Rembouskos G. , Sonek J. , Nicolaides K. H. 
Published: May 2004

AbstractObjectiveTo determine the value of measuring maxillary length at 11–14 weeks of gestation in screening for trisomy 21.MethodsIn 970 fetuses ultrasound examination was carried out for measurement of crown–rump length (CRL), nuchal translucency and maxillary length, and to determine if the nasal bone was present or absent, immediately before chorionic villus sampling for karyotyping at 11–14 weeks of gestation. In 60 cases the maxillary length was measured twice by the same operator to calculate the intraobserver variation in measurements.ResultsThe median gestation was 12 (range, 11–14) weeks. The maxilla was successfully examined in all cases. The mean difference between paired measurements of maxillary length was −0.012 mm and the 95% limits of agreement were −0.42 (95% CI, −0.47 to −0.37) to 0.40 (95% CI, 0.35 to 0.44) mm. The fetal karyotype was normal in 839 pregnancies and abnormal in 131, including 88 cases of trisomy 21. In the chromosomally normal group the maxillary length increased significantly with CRL from a mean of 4.8 mm at a CRL of 45 mm to 8.3 mm at a CRL of 84 mm. In the trisomy 21 fetuses the maxillary length was significantly shorter than normal by 0.7 mm and in the trisomy 21 fetuses with absent nasal bone the maxilla was shorter than in those with present nasal bone by 0.5 mm. In fetuses with other chromosomal defects there were no significant differences from normal in the maxillary length.ConclusionAt 11–14 weeks of gestation, maxillary length in trisomy 21 fetuses is significantly shorter than in normal fetuses. Copyright © 2004 ISUOG. Published by John Wiley & Sons, Ltd.
Doppler blood flow velocity waveforms in the fetal renal arteries: variability at proximal and distal sites in the right and left arteries
Authors: Haugen G. , Godfrey K. , Crozier S. , Hanson M. 
Published: May 2004

AbstractObjectiveTo investigate variability in pulsatility/resistance indices and absolute velocities of blood flow in fetal renal arteries dependent on side and sampling site within each vessel.MethodsDoppler blood flow measurements of pulsatility index (PI), resistance index (RI) and peak systolic velocity (PSV) and end‐diastolic velocity (EDV) were performed in the renal arteries of 27 fetuses between 236 and 247 days of gestation. Velocity waveforms were sampled in both the right and left renal arteries at two different sites: proximally, close to the aorta, and distally, before any major visible bifurcation of the vessels. The intraobserver variation was measured in 15 additional fetuses.ResultsMean values of PI and RI were similar in the right and left renal arteries and at the proximal and distal sampling sites of these arteries. Mean PSV and EDV were higher at the proximal compared to the distal site on both sides. For all parameters the 95% limits of agreement between measurements made in the right and left arteries and at proximal and distal sites were wide but tended to be narrower for the left renal artery and at the distal site. Intraclass correlation coefficients for intraobserver variability were 0.88, 0.89, 0.83 and 0.81 for PI, RI, PSV and EDV, respectively.ConclusionsIt is important to standardize the precise site at which Doppler blood flow velocity waveform measurements are made in the renal arteries of the fetus. On the basis of our observations, we suggest that the left renal artery is the preferred vessel for sampling and that measurements should be made in the renal arterial trunk away from the aorta and before any visible branches. Copyright © 2004 ISUOG. Published by John Wiley & Sons, Ltd.
Organometallic Molybdenum(V) Complexes with Primary Phosphine Ligands. Syntheses, Spectroscopic Properties and Molecular Structures of [Cp°MoCl4(PH2R)] (R = But, 1‐Ad, Cy, Ph, 2, 4, 6‐Me3C6H2, 2, 4, 6‐Pri3C6H2, Cp° = C5EtMe4)
Authors: Felsberg Reinhard , Blaurock Steffen , Junk Peter C. , Kirmse Reinhard , Voigt Andreas , Hey‐Hawkins Evamarie 
Published: May 2004

Abstract[Cp°MoCl4] (Cp° = C5EtMe4) reacts with primary phosphines PH2R to give the paramagnetic phosphine complexes [Cp°MoCl4(PH2R)] [Cp° = C5EtMe4, R = But (1), 1‐Ad (1‐Ad = 1‐adamantyl; 2), Cy (3), Ph (4), Mes (Mes = 2, 4, 6‐Me3C6H2; 5), Tipp (Tipp = 2, 4, 6‐Pri3C6H2; 6)]. 1—6 were characterized spectroscopically (IR, MS), and X‐ray crystal structures were determined for 1—4 and 6. EPR investigations in liquid and frozen solution confirmed the presence of MoV species, and the data were used to analyze the spin‐density distribution in the first coordination sphere. Complexes 3 and 4 react with two equivalents of NEt3 with formation of [Cp°MoCl2(η3‐P4Cy4H)] (7) and [Cp°2Mo2(μ‐Cl)2(μ‐P4Ph4)] (8), respectively, in low yield. Complexes 7 and 8 were characterized by X‐ray crystallography.
Diimido‐, Imido(oxo)‐, Dioxo‐ und Imido(alkyliden)‐Halbsandwich‐Verbindungen über selektive Hydrolyse und α—H‐Abstraktion an Organylkomplexen des sechswertigen Molybdäns und Wolframs
Authors: Radius Udo , Wahl Günter , Sundermeyer Jörg 
Published: May 2004

AbstractOrganometall‐Imide [(η5‐C5R5)M(NR′)2Ph] (M = Mo, W, R = H, Me, R′ = Mes, tBu) 4 — 8 lassen sich durch Umsetzung der chlorfunktionellen Halbsandwich‐Verbindungen [(η5‐C5R5)M(NR′)2Cl] mit Phenyllithium in guten Ausbeuten darstellen. Ausgehend von den Phenylverbindungen 4—8 von sowie von bereits zuvor beschriebenen Methylverbindungen [(η5‐C5Me5)M(NtBu)2Me] (M = Mo, W) werden mit verdünnter Salzsäure die Imido(oxo)‐Methyl‐ bzw. Phenyl‐Komplexe [(η5‐C5Me5)M(NtBu)(O)(R)] M = Mo, R = Me (9), Ph (10); M = W, R = Ph (11) und die Dioxo‐Komplexe [(η5‐C5Me5)M(O)2(CH3)] M = Mo (12), M = W (13) gewonnen. Die Hydolyse von Organometall‐Imiden unter Erhalt von M‐C σ‐ und π‐Bindungen stellt somit eine interessante Alternative zur Gewinnung von Organometall‐Oxiden dar, verglichen mit bekannten Strategien, die sich der oxidativen Decarbonylierung niedervalenter Alkyl‐Carbonyl‐ und Alkyl‐Nitrosylkomplexe bedienen. Auch die Protolyse von [(η5‐C5H5)W(NtBu)2(CH3)] und [(η5‐C5Me5)Mo(NtBu)2(CH3)] mit HCl‐Gas führt unter Erhalt der M‐C‐Bindungen zu [(η5‐C5H5)W(NtBu)Cl2(CH3)] 14 und [(η5‐C5Me5)Mo(NtBu)Cl2(CH3)] 15. Die Inertheit der recht unpolaren M‐C‐σ‐Bindung gegenüber Protolyse bietet somit eine Strategie zur gezielten Synthese von Methylchloro‐Komplexen, die auf anderem Weg, etwa über die partielle Methylierung von [(η5‐C5R5)M(NR′)Cl3] mit MeLi nicht rein darstellbar sind. Als Reinstoffe lassen sich aus dieser Reaktion lediglich die Trimethylverbindungen [(η5‐C5R5)M(NtBu)(CH3)3] 16‐18, M = Mo, W, R = H, Me, gewinnen. Imido(benzyliden)‐Komplexe [(η5‐C5Me5)M(NtBu)(CHPh)(CH2Ph)] M = Mo (19), W (20) entstehen dagegen unter α‐H‐Abstraktion bei Alkylierung von [(η5‐C5Me5)M(NtBu)Cl3] mit PhCH2MgCl. Auf Basis von NMR‐Daten zeichnet sich ein Trend abnehmender Donorfähigkeit der Liganden [NtBu]2— > [O]2— > [CHR]2— ≫ 2 [CH3]— > 2 [Cl]— ab.
Das erste oxidische T5‐Supertetraeder: Na26Mn39O55
Authors: Möller Angela , Amann Peter , Kataev Vladislav , Schittner Norbert 
Published: May 2004

AbstractNa26Mn39O55 wurde durch eine Redoxreaktion von metallischem Mangan mit CdO in Gegenwart von Na2O und Na2SO4 als Mineralisator in Form roter Einkristalle mit oktaedrischem Habitus erhalten. Die Kristallstruktur konnte anhand von Einkristalldaten bestimmt werden (Fd3¯m, Z = 8, a = 2377, 4(3) pm bei 293 K und a = 2372, 5(2) pm bei 130 K). Das seltene charakteristische Strukturelement eines T5‐Supertetraeders, [Mn35O56], zeichnet die Kristallstruktur des neuen gemischtvalenten Natrium‐Oxomanganats(II, III), Na26Mn39O55, aus. Über erste Untersuchungen des ungewöhnlichen magnetischen Verhaltens wird berichtet.
Zur Elektronenstruktur metallorganischer Komplexe der f‐Elemente. 60 [1] Strukturelle, einkristalloptische und magnetooptische Untersuchungen von Trialkylphosphat‐Addukten des Grundkörpers Tris(cyclopentadienyl)lanthanid(III) (Ln = La, Pr) sowie Ergebnisse vergleichender optischer Studien an [Pr(Ind)3(OP(OEt)3)] (Ind = Indenyl)
Authors: Apostolidis Christos , Morgenstern Alfred , Walter Olaf , Reddmann Hauke , Amberger Hanns‐Dieter 
Published: May 2004

Abstract[Ln(Cp)3(OP(OR)3)] (Cp = η5‐Cyclopentadienyl; Ln = La, R = Et (1); Ln = Pr, R = Me (2); Ln = Pr, R = Et (3)) und [Pr(Ind)3(OP(OEt)3)] (4) wurden synthetisiert und spektroskopisch sowie teilweise strukturell (nur Verbindungen 1 und 2) charakterisiert. Auf der Grundlage der bei variablen Temperaturen aufgenommenen α‐Absorptionsspektren eines orientierten Einkristalls, der magnetischen Zirkulardichroismusspektren von gelöstem, und der Lumineszenzspektren von gepulvertem Material konnte ein fast vollständiges Kristallfeld(KF)‐Aufspaltungsmuster von 3 aufgestellt und durch Anpassung der freien Parameter eines phänomenologischen Hamilton‐Operators simuliert werden. Die hierbei verwendeten Parameter erlaubten die Berechnung der vom Pr3+‐Zentralion wahrgenommenen globalen KF‐Stärke, die Abschätzung der nephelauxetischen und relativistischen nephelauxetischen Parameter, sowie die Aufstellung der experimentorientierten nichtrelativistischen und relativistischen Molekülorbital‐Schemata im f‐Bereich. Die optischen Spektren von Verbindung 4 weisen auf die Existenz zweier unterschiedlicher Spezies bei tiefen Temperaturen hin, wodurch eine erfolgreiche KF‐Analyse der Spektren verhindert wird.
On the Reaction of [(CO)3Fe(μ‐Me2NCO)2Fe(CO)2(NHMe2)] with Chelating Ligands — X‐Ray Structures of New Binuclear μ‐Carbamoyl Complexes
Authors: Petz Wolfgang , Neumüller Bernhard , Pudewills Jens 
Published: May 2004

AbstractReaction of the binuclear μ‐carbamoyl complex [(CO)3Fe(μ‐Me2NCO)2Fe(CO)2(HNMe2)] (1) in toluene with the chelating ligands Ph2PCH2PPh2 (dppm) and Ph2PCH2CH2PPh2 (dppe) gives different results. With dppm only the complex [(CO)3Fe(μ‐Me2NCO)2Fe(CO)2(dppm)] (3) with a dangling ligand is obtained under replacement of amine, whereas with dppe depending on the reaction conditions up to three compounds are found. A 1 : 1 mixture of the educts generates the related complex [(CO)3Fe(μ‐Me2NCO)2Fe(CO)2(dppe)] (4) together with the tetranuclear complex [{(CO)3Fe(μ‐Me2NCO)2Fe(CO)2}2(dppe)] (5). 4 slowly converts into [(CO)3Fe(μ‐Me2NCO)2Fe(CO)(dppe)] (6) with dppe acting as a chelating ligand. 6 is the first compound in this series in which one of the five CO groups is replaced by another donor. A 2 : 1 molar ratio of 1 and dppe quantitatively produces 5. Addition of CO to a solution of 6 proceeds under slow reversible conversion of the complex into 4. The compounds were characterized by the usual spectroscopic methods; 3, 5 and 6 were also studied by X‐ray diffraction analyses.
A One‐dimensional Lead(II) Coordination Polymer with Bridging Saccharinate and 2‐Aminomethylpyridine Ligands: Synthesis, IR Spectra, and Crystal Structure of [Pb(ampy)(μ‐sac)2]n
Authors: Yilmaz Veysel T. , Caglar Sema , Harrison William T. A. 
Published: May 2004

AbstractA complex with eight‐coordinate lead(II) atom and saccharinate (sac) and 2‐aminomethylpyridine ligands was characterized by IR, elemental analysis and X‐ray crystallography. The lead(II) complex crystallizes in the monoclinic crystal system with space group P21/c. The single crystal X‐ray analysis shows that the complex is a coordination polymer, [Pb(ampy)(μ‐sac)2]n, in which the lead(II) ions have a highly distorted bicapped trigonal antiprism coordination. Lead(II) ions are bridged by carboxyl groups of sac forming one‐dimensional linear chains, running parallel to the a axis. The intrachain Pb···Pb distances are 4.4490(3) and 4.4679(3)Å. The individual chains are connected by N—H···Osulfonyl and Campy—H···Osulfonyl type hydrogen bonds, resulting in a three‐dimensional network. The sac ligand acts as bidentate and bridging ligand, while ampy behaves as an N, N′ donor. The IR spectra of the lead(II) complex are discussed in detail.
Metallat‐Ionen [Al(OR)4]— als Chelatliganden für Übergangsmetall‐Kationen
Authors: Pauls Jochen , Iravani Effat , Köhl Peter , Neumüller Bernhard 
Published: May 2004

AbstractWasserfreies CoCl2 kann mit [{Li(Diglyme)}{Al(OtBu)4}] in THF zum Komplex [Li(THF)4][{CoCl2}{Al(OtBu)4}] umgesetzt werden. Zusatz von Diglyme zu den Reaktionslösungen liefert die blaue Verbindung [Li(Diglyme)2][{CoCl2}{Al(OtBu)4}] (1). Nach der gleichen Vorgehensweise bildet sich mit FeCl2 der FeII‐Komplex [Li(Diglyme)2][{FeCl2}2{Al(OtBu)4}] (2). [{Li(Diglyme)}{Al(OtBu)4}] in THF/Diglyme dient als Alkoxid‐Übertragungsreagenz auf TiCl4 und führt zum Neutralkomplex [TiCl2(OtBu)2(Diglyme)] (3). Wird Li[Al(OCH2Ph)4] mit CoCl2 in THF zur Reaktion gebracht, bildet sich das himmelblaue Salz [Li(THF)4]2[{CoCl2}3{Al(OCH2Ph)4}2] (4). Nach Behandlung von 4 mit Diglyme findet teilweise Ligandenredistribution statt, was zum himmelblauen [Li(Diglyme)2]2[{CoCl2}3{Al(OCH2Ph)4}2] (5) und zum veilchenblauen [Li(Diglyme)2]2[Co2Cl5(OCH2Ph)] (6) führt. Ein entprechendes Salz kann auch direkt aus Li[Al(OtBu)4] und CoCl2 in Diglyme als [Li(Diglyme)2]2[Co2Cl5(OtBu)] (7) isoliert werden.1 — 7 wurden mittels IR‐Spektroskopie, teilweise durch Massenspektrometrie und Röntgenstrukturanalysen charakterisiert. Von 1 und 5 wurden dazu UV‐VIS‐Spektren angefertigt. Nach den Röntgenstrukturanalysen sind sowohl die MII‐Ionen [MII = Fe2+, Co2+] als auch die AlIII‐Ionen in allen Fällen verzerrt tetraedrisch koordiniert. In 1, 2, 4 und 5 wirkt die Einheit [Al(OR)4]— auch wie erhofft als Chelatligand.
Commentary on women‐centered reproductive health services
Authors: Toro Olga Lucia 
Published: May 2004

AbstractFrom women's perspectives, the primary principles of a reproductive health framework in the developing world are as follows:

Family planning is a basic human right to which all human beings are entitled. Provision of family planning services must be comprehensive, including safe and low cost methods, freedom of choice about both contraception and pregnancy termination, timely and honest information, privacy and confidentiality, individual needs assessment, and counseling of women, men or the couple. Wide contraceptive choice requires more research on methods that are less invasive of women's anatomy and physiology and more supportive of women's control of their own bodies. These parameters of quality care in family planning must be centered on women's needs, desires and expectations.
The concept of conscious contraception implies an attitude of conscious sexuality. When a woman accepts that sexual gratification independent of reproduction is a legitimate right, she is better prepared to engage in the pursuit of her own health and happiness. If family planning programs do not include sexuality as a key issue to discuss with clients, all long‐term strategies will fall short in modifying people's attitudes, especially women's reluctance to contracept.
Sexual and reproductive health includes emotional health. As Dr. Sai points out, the effects of underdevelopment and poverty strike women in dramatic ways, and quite often all the pressures to which they are exposed lead to precarious emotional health. They become victims of violence and repeat the cycle of violence with their children. We, as advocates of sexual and reproductive rights, must also consider the psychological and emotional implications of sexuality and reproduction, and learn to deal with them in our clinics and services.
We must discuss, understand and take firm positions regarding major ethical issues in sexual and reproductive health. These include regulation of drug marketing, of policies for research on human subjects, and of coercion of individuals or governments to accept contraception, or abortion, for whatever reasons.
Finally, we must understand that the pursuit of sexual and reproductive health requires the decriminalization of abortion. Legal restrictions on abortion are lethal means of violence against women. Silence on these restrictions masks an enormous amount of suffering among women in Third World countries.I invite you to make a commitment to women's rights by exploring, with courage and dedication, creative and simple ways to provide comprehensive reproductive health services.
Effects of self‐complexity on mood‐incongruent recall1
Authors: SAKAKI MICHIKO 
Published: May 2004

Abstract:  Some people cope with negative moods by retrieving positive memories, which is mood‐incongruent recall. Though mood‐incongruent recall is helpful for mood‐regulation, the factors that influence people's ability to utilize mood‐incongruent recall are not well understood. This study investigated whether complex knowledge structure is a factor for the ability of mood‐incongruent recall, based on self‐complexity. In the experiment, 50 participants were requested to recall positive memories in both neutral and negative moods. The results of this study indicated that self‐complexity was an important factor associated with participants’ ability to recall positive memories while they were in negative moods. Participants who rated high in self‐complexity were those whose knowledge is structured in a complex way, recalled more highly positive memories in negative moods than in neutral moods. On the other hand, participants who were rated low in self‐complexity with simple knowledge structures recalled memories with a lower extent of positivity in negative moods than those in neutral moods.
Fish habitat requirements as the basis for rehabilitation of eutrophic lakes by oxygenation
Authors: Müller R. , Stadelmann P. 
Published: May 2004

AbstractEutrophic lakes often suffer from hypolimnetic oxygen depletion during summer and autumn, and the accumulation of reduced substances in the hypolimnion. The space fish can occupy is therefore reduced, and the potential for fish kills caused by toxic algae and the upwelling of anoxic water increases. Fish, such as coregonids, require at least 4 mg O2 L−1 to survive in the long‐term. This critical level has been postulated as one of the major goals for the rehabilitation of several eutrophic Swiss lakes. It was predicted that this oxygen criterion would reduce phosphorus release from the sediment and increase phosphorus retention, and re‐establish natural reproduction of coregonids. Rehabilitation measures applied to three eutrophic Swiss lakes were hypolimnetic oxygenation during summer stratification, and artificial mixing using compressed air to enhance circulation in winter. These lake‐internal measures carried out for more than 15 years showed the 4 mg O2 L−1 criterion can be achieved most of the time. The measures have led to an expansion of habitat for oxygen‐dependent organisms to greater depths. However, other goals were not attained, such as increasing phosphorus retention by the sediment. In addition, natural reproduction of coregonids could not be re‐established. Excessive oxygen consumption by the sediment, arising from the decomposition of deposited organic matter produced during summer, caused death by suffocation of coregonid eggs developing on the sediment. Thus rehabilitation of eutrophic lakes by oxygenating the hypolimnion and artificial mixing will not be successful, unless it is accompanied by lowering the nutrient loading and thus primary production and oxygen consumption by the sediment. Nevertheless, positive effects of lake aeration were the expansion of living space for fish and benthic invertebrates, and the prevention of fish kills by upwelling anoxic hypolimnetic water.