bluuebunny/crossref_metadata_2025_split huggingface dataset:
NaCu5(C2)3: The First Alkali Metal Transition Metal Acetylide with a Three‐dimensional Framework Structure
Authors: Cremer Ulrich , Ruschewitz Uwe 
Published: January 2004

AbstractBy heating the red residue of the reaction of NaC2H and CuI in liquid ammonia at 463 K for 30 min in a dynamic vacuum orange polycrystalline NaCu5(C2)3 is obtained. The crystal structure was solved and refined from X‐ray powder diffraction data (orthorhombic, Pnma, a = 732.80(2) pm, b = 1099.63(4) pm, c = 726.15(2) pm, Z = 4, RB = 0.030). It consists of a three‐dimensional framework of CuI and C22— ions with small channels running parallel to [100] and [001]. The sodium ions reside at the intersections of these channels. The vibrational spectra of NaCu5(C2)3 show some similarities with the spectra of phenylethynylcopper(I), but they are different to those of Cu2C2. Therefore NaCu5(C2)3 does probably not represent a crystalline model compound for the unknown structure of amorphous Cu2C2.
Untersuchungen im System LaI2/H2: Phasenverhältnisse und Fehlordnung
Authors: Ryazanov Mikhail , Simon Arndt , Mattausch Hansjürgen 
Published: January 2004

AbstractErhitzen von LaI2 unter 1 bar Wasserstoff auf 650 °C führt zu hellgrauem LaI2H0.95(3), gleichzeitig ändert sich die Symmetrie von tetragonal nach hexagonal. Indizierung der scharfen Reflexe des Röntgenpulverdiagramms in P63/mmc ergibt a = 4.2158(7)Å und c = 15.508(3)Å. Diffus verbreiterte Linien weisen auf eine Stapelfehlordnung in der Struktur hin, die einer polytypen Verwachsung von MoS2‐ und NbS2‐Varianten entspricht. Erhöhung der Reaktionstemperatur auf 730 °C führt zu einem schärferen Pulverdiagramm, das im wesentlichen als 2H‐NbS2‐Typ beschreibbar ist.Röntgenographische Untersuchungen von Proben LaI2Hn belegen die Mischungslücke zwischen LaI2 und LaI2Hn (0 ≤ n ≤ 0.5) in guter Übereinstimmung mit den früher ermittelten Werten. Mit sinkendem H‐Gehalt ändern sich die Gitterkonstanten im Homogenitätsgebiet gegenläufig und betragen für die untere Phasengrenze a = 4.236(1)Å, c = 15.39(2)Å.
Enantioselektive Katalysen. 155 [1] (Cymol)Ruthenium‐Halbsandwich‐Komplexe mit Pyrroloxazolin‐Liganden — Synthese, Stereochemie, Katalyse
Authors: Brunner Henri , Henning Frauke , Zabel Manfred 
Published: January 2004

AbstractDie (Cymol)Ruthenium‐Halbsandwich‐Komplexe K1 und K2 mit chiralen Pyrroloxazolin‐Liganden wurden synthetisiert und charakterisiert. Die Komplexe bilden Diastereomere, die sich nur in der Metallkonfiguration unterscheiden. Der Komplex K1 kristallisiert in Form des reinen Diastereomers SRu, SC4, RC5. In Lösung erfolgt Epimerisierung SRu, SC4, RC5 ⇌ RRu, SC4, RC5 durch Konfigurationsänderung am Rutheniumatom. Die Halbwertszeit für diese Reaktion erster Ordnung bei 0.4 °C in CD2Cl2 beträgt 50.6 min. Damit stehen die beiden Diastereomeren bei Raumtemperatur miteinander im Gleichgewicht. Die Gleichgewichtsgemische von K1 und K2 wurden als Katalysatoren für die Transferhydrierung von Acetophenon und für die Diels‐Alder‐Reaktion von Cyclopentadien mit Methacrolein eingesetzt. Dabei wurden Enantiomerenüberschüsse bis 60 % ee erreicht.
Zur Synthese und Struktur von K3N
Authors: Fischer D. , Cancarevic Z. , Schön J. C. , Jansen M. 
Published: January 2004

AbstractDurch simultane Bedampfung eines Saphirsubstrates mit Kalium und Stickstoff bei 77 K und anschließendem Aufwärmen wurden zwei Kaliumnitrid‐Phasen erhalten. Das Diffraktogramm der einen Phase läßt sich befriedigend unter der Annahme der Zusammensetzung K3N und Isotypie zu Cs3O (anti‐TiI3 Typ) interpretieren (hexagonal, P63/mcm, a = 779.8(2), c = 759.2(9) pm, Z = 2). Ein Vergleich mit Strukturmodellen, die mit theoretischen Methoden generiert und anschließend auf Hartree‐Fock‐ und DFT Niveau verfeinert wurden, zeigt, dass die hier für K3N beobachtete Modifikation nicht die thermodynamisch stabilste (vermutlich Li3P‐Typ) sondern eine der am wenigsten dichten Formen ist. Insofern sind die Verhältnisse analog zu denen bei Na3N. Das thermische Verhalten der Proben wurde untersucht. Danach wandelt sich hexagonales K3N bei 233 K in eine zweite K/N‐Phase um, deren Pulverdiffraktogramm sich orthorhombisch mit a = 1163, b = 596, c = 718 pm indizieren läßt. Bei 263 K findet Zersetzung unter Bildung von Kalium statt.
(LiI)2Li3SbS3: A mixed Alkali Metal Halide Thioantimonate with a novel Tetrahedron Network
Authors: Pfitzner Arno , Preitschaft Christian , Rau Franz 
Published: January 2004

Abstract(LiI)2Li3SbS3 was prepared by solid‐state reaction of stoichiometric amounts of LiI, Li, Sb, and S in the ratio 2 : 3 : 1 : 3. The product is air and moisture sensitive. The crystal structure was determined from single crystals at room temperature. Colourless to pale yellow (LiI)2Li3SbS3 crystallizes in the orthorhombic system, space group Pnnm (no. 58) with a = 10.436(1)Å, b = 13.509(1)Å, c = 7.530(1)Å, V = 1061.6(1)Å3, and Z = 4 (data at 20 °C). The crystal structure of (LiI)2Li3SbS3 is closely related to that of (CuI)2Cu3SbS3 and (AgI)2Ag3SbS3, at least for the positions of I, Sb, and S. Thus, iodine forms an eutactic arrangement which resembles the structure of hexagonal diamond. [SbS3]3— units are embedded in this framework in a way that the sulphur atoms of two adjacent trigonal pyramids form distorted octahedral voids. The lithium ions are tetrahedrally coordinated and fully ordered within the anionic framework. The three‐dimensional connectivities in (LiI)2Li3SbS3 are significantly different from the homologous copper and silver compound due to the bonding necessities of Li and slightly different radii of the monovalent cations. Thus, a novel three‐dimensional network of edge sharing tetrahedra is observed in (LiI)2Li3SbS3. It exhibits strands of eight‐membered rings of edge sharing tetrahedra which are linked by common vertices and cross linked by double tetrahedra.
Volume Chemistry of Nitrogen in Binary Metal Nitrides and Subnitrides
Authors: Bronger Welf , Kniep Rüdiger , Kohout Miroslav 
Published: January 2004

AbstractA comparison of the concept of volume increments created by W. Biltz with that based on quantum mechanical calculations by R.F.W. Bader was performed for crystal structures of binary metal nitrides and ‐subnitrides. The mutual comparison of both concepts permits insights into the bonding relationships of these compounds and reveals the considerable range of volume demand of a strongly polarisable bonding partner, such as the nitride ion. Finally it becomes clear that the Biltz volume increments show a quantum‐chemical relevance in the chemistry of solids.
Representativeness uncertainty in chemical data assimilation highlight mixing barriers
Authors: Lary David John 
Published: January 2004

AbstractWhen performing chemical data assimilation the observational, representativeness, and theoretical uncertainties have very different characteristics. In this study, we have accurately characterized the representativeness uncertainty by studying the probability distribution function (PDF) of the observations. The average deviation has been used as a measure of the width of the PDF and of the variability (representativeness uncertainty) for the grid cell. It turns out that for long‐lived tracers such as N2O and CH4 the representativeness uncertainty is markedly different from the observational uncertainty and clearly delineates mixing barriers such as the polar vortex edge, the tropical pipe and the tropopause. Published by Elsevier Ltd on behalf of Royal Meteorological Society.
Effects of the menstrual cycle on mood, neurocognitive and neuroendocrine function in healthy premenopausal women
Authors: SYMONDS C. S. , GALLAGHER P. , THOMPSON J. M. , YOUNG A. H. 
Published: January 2004

Background. Neurocognitive functioning may be impaired in the luteal phase of the menstrual cycle due to associated changes in hypothalamic–pituitary–adrenal (HPA) axis function. This study examines the relationship between changes in neurocognition and HPA axis function in different phases of the menstrual cycle.Method. Fifteen female volunteers, free from psychiatric history and hormonal medication were tested twice, during mid-follicular and late-luteal phases in a randomized, crossover design. Mood, neurocognitive function, and basal cortisol and dehydroepiandrosterone (DHEA) were profiled.Results. Relative to the follicular phase, verbal fluency was impaired in the luteal phase and reaction times speeded on a continuous performance task, without affecting overall accuracy. ‘Hedonic’ scores on the UWIST-MACL scale were decreased in the luteal phase. There was also evidence of changes in the function of the HPA axis, with 24 h urinary cortisol concentrations and salivary DHEA levels being significantly lower during the luteal phase.Conclusions. These data suggest that luteal phase HPA axis function is lower than in the follicular phase in premenopausal healthy women. This putative biological difference may be important for our understanding of the aetiopathogenesis of menstrually related mood change and neurocognitive disturbance.
Treatment response in late-onset depression: relationship to neuropsychological, neuroradiological and vascular risk factors
Authors: BALDWIN R. , JEFFRIES S. , JACKSON A. , SUTCLIFFE C. , THACKER N. , SCOTT M. , BURNS A. 
Published: January 2004

Background. Late-onset depressive disorder is associated with white matter lesions and neuropsychological deficits that in some studies are linked to a poorer outcome for depression. Some white matter lesions may be vascular in origin. This study investigated the relationship between response or non-response to antidepressant monotherapy and neuropsychological function, structural brain measures and vascular factors.Method. This was a case–control study. Fifty patients with late-onset major depressive disorder (29 who were responders to antidepressant monotherapy and 21 who were not) were compared with 35 non-depressed control subjects. Measures included assessment of vascular risk factors, neuropsychological testing and a magnetic resonance imaging (MRI) scan.Results. After adjustment for depressed mood and medication at evaluation, both patient groups had significantly more impairment compared to control subjects on verbal learning tasks involving immediate or delayed recall. Patients who did not respond to antidepressant monotherapy had significantly poorer performance than controls on tests involving visuospatial ability, language, word recognition and tests of executive function, whereas there were no differences between control subjects and responders. On two tests of executive function (verbal fluency and the Stroop test) non-responders scored significantly worse than responders. There were no significant group differences on MRI measures of atrophy or of white matter lesions apart from a higher periventricular hyperintensity score in non-responders compared to controls. There were no group differences on measures of vascular disease.Conclusion. The results lend support to the emerging evidence that resistance to treatment in late-onset depression may be associated with impaired executive function. Subtle cerebrovascular mechanisms may be involved.
Activation of group III metabotropic glutamate receptors in selected regions of the basal ganglia alleviates akinesia in the reserpine‐treated rat
Authors: MacInnes Nicholas , Messenger Marcus J , Duty Susan 
Published: January 2004

This study examined whether group III metabotropic glutamate (mGlu) receptor agonists injected into the globus pallidus (GP), substantia nigra pars reticulata (SNr) or intracerebroventricularly (i.c.v.) could reverse reserpine‐induced akinesia in the rat.
Male Sprague–Dawley rats, cannulated above the GP, SNr or third ventricle, were rendered akinetic with reserpine (5 mg kg−1 s.c.). 18 h later, behavioural effects of the group III mGlu receptor agonists L‐serine‐O‐phosphate (L‐SOP) or L‐(+)‐2‐amino‐4‐phosphonobutyric acid (L‐AP4) were examined.
In reserpine‐treated rats, unilateral injection of L‐SOP (2000 and 2500 nmol in 2.5 μl) into the GP produced a significant increase in net contraversive rotations compared to vehicle, reaching a maximum of 83±21 rotations 120 min−1 (n=8). Pretreatment with the group III mGlu receptor antagonist methyl‐serine‐O‐phosphate (M‐SOP; 250 nmol in 2.5 μl) inhibited the response to L‐SOP (2000 nmol) by 77%.
Unilateral injection of L‐SOP (250‐1000 nmol in 2.5 μl) into the SNr of reserpine‐treated rats produced a dose‐dependent increase in net contraversive rotations, reaching a maximum of 47±6 rotations 30 min−1 (n=6). M‐SOP (50 nmol in 2.5 μl) inhibited the response to L‐SOP (500 nmol) by 78%.
Following i.c.v. injection, L‐SOP (2000–2500 nmol in 2.5 μl) or L‐AP4 (0.5–100 nmol in 2 μl) produced a dose‐dependent reversal of akinesia, attaining a maximum of 45±17 (n=8) and 72±3 (n=9) arbitrary locomotor units 30 min−1, respectively.
These studies indicate that injection of group III mGlu receptor agonists into the GP, SNr or cerebral ventricles reverses reserpine‐induced akinesia, the mechanism for which remains to be established.

British Journal of Pharmacology (2004) 141, 15–22. doi:10.1038/sj.bjp.0705566
Pharmacological characterisation of a rat model of incisional pain
Authors: Whiteside Garth T , Harrison James , Boulet Jamie , Mark Lilly , Pearson Michelle , Gottshall Susan , Walker Katharine 
Published: January 2004

Both clinical and preclinical models of postsurgical pain are being used more frequently in the early evaluation of new chemical entities. In order to assess the validity and reliability of a rat model of postincisional pain, the effects of different classes of clinically effective analgesic drugs were evaluated against multiple behavioural end points.
Following surgical incision, under general anaesthesia, of the plantar surface of the rat hind paw, we determined the time course of mechanical hyperalgesia, tactile allodynia and hind limb weight bearing using the Randall–Selitto (paw pressure) assay, electronic von Frey and dual channel weight averager, respectively. Behavioural evaluations began 24 h following surgery, and were continued for 9–14 days.
Mechanical hyperalgesia, tactile allodynia and a decrease in weight bearing were present on the affected limb within 1 day of surgery with maximum sensitivity 1–3 days postsurgery. Accordingly, we examined the effect of nonsteroidal antiinflammatory drugs (NSAIDs), morphine and gabapentin, on established hyperalgesia and allodynia, 1 day following plantar incision.
In accordance with previous reports, both systemic morphine and gabapentin administration reversed mechanical hyperalgesia and tactile allodynia in the incised rat hind paw. Both drugs were more potent against mechanical hyperalgesia than tactile allodynia.
All of the NSAIDs tested, including cyclooxygenase 2 selective inhibitors, reversed mechanical hyperalgesia and tactile allodynia in the incised rat hind paw. The rank order of potency for both hyperalgesia and allodynia was indomethacin > celecoxib > etoricoxib > naproxen.
We have investigated the potency and efficacy of different classes of analgesic drugs in a rat model of postincisional pain. The rank order of potency for these drugs reflects their utility in treating postoperative pain in the clinic. As these compounds showed reliable efficacy across two different behavioural end points, the Randall–Selitto (paw pressure) assay and electronic von Frey, these methods may prove useful in the study of postsurgical pain and the assessment of novel treatments.

British Journal of Pharmacology (2004) 141, 85–91. doi:10.1038/sj.bjp.0705568
Autoradiographic distribution of 5‐HT7 receptors in the human brain using [3H]mesulergine: comparison to other mammalian species
Authors: Martín‐Cora Francisco J , Pazos Angel 
Published: January 2004

The main aim of this investigation was to delineate the distribution of the 5‐HT7 receptor in human brain. Autoradiographic studies in guinea‐pig and rat brain were also carried out in order to revisit and compare the anatomical distribution of 5‐HT7 receptors in different mammalian species.
Binding studies were performed in rat frontal cortex membranes using 10 nM [3H]mesulergine in the presence of raclopride (10 μM) and DOI (0.8 μM). Under these conditions, a binding site with pharmacological characteristics consistent with those of the 5‐HT7 receptors was identified (rank order of binding affinity values: 5‐CT>5‐HT>5‐MeOT>mesulergine ∼methiothepin>8‐OH‐DPAT=spiperone ∼(+)‐butaclamol≫imipramine ∼(±)‐pindolol≫ondansetron ∼clonidine ∼prazosin).
The autoradiographic studies revealed that the anatomical distribution of 5‐HT7 receptors throughout the human brain was heterogenous. High densities were found over the caudate and putamen nuclei, the pyramidal layer of the CA2 field of the hippocampus, the centromedial thalamic nucleus, and the dorsal raphe nucleus. The inner layer of the frontal cortex, the dentate gyrus of the hippocampus, the subthalamic nucleus and superior colliculus, among others, presented intermediate concentrations of 5‐HT7 receptors. A similar brain anatomical distribution of 5‐HT7 receptors was observed in all three mammalian species studied.
By using [3H]mesulergine, we have mapped for the first time the anatomical distribution of 5‐HT7 receptors in the human brain, overcoming the limitations previously found in radiometric studies with other radioligands, and also revisiting the distribution in guinea‐pig and rat brain.

British Journal of Pharmacology (2004) 141, 92–104. doi:10.1038/sj.bjp.0705576
The superoxide dismutase mimetic, tempol, blunts right ventricular hypertrophy in chronic hypoxic rats
Authors: Elmedal Britt , De Dam Mette Y , Mulvany Michael John , Simonsen Ulf 
Published: January 2004

The purpose of this study was to investigate whether a membrane‐permeable superoxide dismutase mimetic, tempol, added either alone or in combination with the nitric oxide (NO) donor molsidomine, prevents the development of pulmonary hypertension (PH) in chronic hypoxic rats.
Chronic hypobaric hypoxia (10% oxygen) for 2 weeks increased the right ventricular systolic pressure (RVSP), right ventricle and lung wet weight. Relaxations evoked by acetylcholine (ACh) and the molsidomine metabolite SIN‐1 were impaired in isolated proximal, but not distal pulmonary arteries, from chronic hypoxic rats.
Treatment with tempol (86 mg kg−1 day−1 in drinking water) normalized RVSP and reduced right ventricular hypertrophy, while systemic blood pressure, lung and liver weights, and blunted ACh relaxation of pulmonary arteries were unchanged.
Treatment with molsidomine (15 mg kg−1 day−1 in drinking water) had the same effects as tempol, except that liver weight was reduced, and potassium and U46619‐evoked vasoconstrictions in pulmonary arteries were increased. Combining tempol and molsidomine did not have additional effects compared to tempol alone. ACh relaxation in pulmonary arteries was not normalized by these treatments.
The media to lumen diameter ratio of the pulmonary arteries was greater for the hypoxic rats compared to the normoxic rats, and was not reversed by treatment with tempol, molsidomine, or the combination of tempol and molsidomine.
We conclude that tempol, like molsidomine, is able to correct RVSP and reduce right ventricular weight in the rat hypoxic model. Functional and structural properties of pulmonary small arteries were little affected. The results support the possibility that superoxide dismutase mimetics may be a useful means for the treatment of PH.

British Journal of Pharmacology (2004) 141, 105–113. doi:10.1038/sj.bjp.0705580
Haemodynamic effects of the selective phosphodiesterase 5 inhibitor, UK‐357,903, in conscious SHR
Authors: Gardiner Sheila M , March Julie E , Kemp Philip A , Ballard Stephen A , Hawkeswood Ed , Hughes Bernadette , Bennett Terence 
Published: January 2004

Regional haemodynamic responses to a continuous, 4‐day infusion of the selective phosphodiesterase type 5 inhibitor, UK‐357,903 (0.133 or 1.33 mg kg−1 h−1) were measured in conscious spontaneously hypertensive rats, and compared with those of enalapril (1 mg kg−1 h−1).
Both doses of UK‐357,903 caused modest reductions in mean blood pressure that were not dose‐dependent and only significantly different from the vehicle effects on Day 1 of the study (mean −11.8 and −15.3 mmHg for low and high doses, respectively). UK‐357,903 had mesenteric and hindquarters vasodilator effects, which were, again, similar for both dose levels and only significantly different from vehicle on Day 1. Neither dose of UK‐357,903 affected renal vascular conductance or heart rate.
Although the haemodynamic effects of UK‐357,903 were not clearly dose‐related and some appeared to wane with time, geometric mean plasma levels of UK‐357,903 increased in proportion to dose, and were sustained throughout the infusion period. Furthermore, plasma cyclic guanosine monophosphate, a biomarker of phosphodiesterase 5 inhibition, was persistently elevated, and increased with increasing dose.
Enalapril caused a fall in mean blood pressure on day 1 (−14.1 mmHg) that was associated with dilatation in renal, mesenteric and hindquarters vascular beds. The haemodynamic effects of enalapril were sustained or increased over the 4‐day infusion, although plasma free drug levels were stable.
In conclusion, we have shown regional and temporal changes in the haemodynamic effects of UK‐357,903, which may be due to activation of compensatory mechanisms, but there were no signs of functional compensation to the cardiovascular effects of enalapril.

British Journal of Pharmacology (2004) 141, 114–122. doi:10.1038/sj.bjp.0705581
Heterogeneity of neuronal and smooth muscle receptors involved in the VIP‐ and PACAP‐induced relaxations of the pig intravesical ureter
Authors: Hernández Medardo , Barahona María Victoria , Recio Paz , Rivera Luis , Benedito Sara , Martínez Ana Cristina , García‐Sacristán Albino , Orensanz Luis M , Prieto Dolores 
Published: January 2004

The mechanisms and receptors involved in the vasoactive intestinal peptide (VIP)‐ and pituitary adenylate cyclase‐activating polypeptide (PACAP)‐induced relaxations of the pig intravesical ureter were investigated.
VIP, PACAP 38 and PACAP 27 concentration‐dependently relaxed U46619‐contracted ureteral strips with a similar potency. [Ala11,22,28]‐VIP, a VPAC1 agonist, showed inconsistent relaxations.
The neuronal voltage‐gated Ca2+ channel inhibitor, ω‐conotoxin GVIA (ω‐CgTX, 1 μM), reduced the VIP relaxations. Urothelium removal or blockade of capsaicin‐sensitive primary afferents, nitric oxide (NO) synthase and guanylate cyclase with capsaicin (10 μM), NG‐nitro‐L‐arginine (L‐NOARG, 100 μM) and 1H‐[1,2,4]‐oxadiazolo[4,3‐a]quinoxalin‐1‐one (ODQ, 5 μM), respectively, did not change the VIP relaxations. However, the PACAP 38 relaxations were reduced by ω‐CgTX, capsaicin, L‐NOARG and ODQ.
The VIP and VIP/PACAP receptor antagonists, [Lys1, Pro2,5, Arg3,4, Tyr6]‐VIP (1 μM) and PACAP (6–38) (0.4 μM), inhibited VIP and VIP and PACAP 38, respectively, relaxations.
The nonselective and large‐conductance Ca2‐activated K+ channel blockers, tetraethylammonium (3 mM) and charybdotoxin (0.1 μM), respectively, and neuropeptide Y (0.1 μM) did not modify the VIP relaxations. The small‐conductance Ca2‐activated K+ channel blocker apamin (1 μM) did not change the PACAP 27 relaxations.
The cAMP‐dependent protein kinase A (PKA) blocker, 8‐(4‐chlorophenylthio)adenosine‐3′,5′‐cyclic monophosphorothioate (Rp‐8‐CPT‐cAMPS, 100 μM), reduced VIP relaxations. The phosphodiesterase 4 inhibitor rolipram and the adenylate cyclase activator forskolin relaxed ureteral preparations. The rolipram relaxations were reduced by Rp‐8‐CPT‐cAMPS. Forskolin (30 nM) evoked a potentiation of VIP relaxations.
These results suggest that VIP and PACAP relax the pig ureter through smooth muscle receptors, probably of the VPAC2 subtype, linked to a cAMP‐PKA pathway. Neuronal VPAC receptors localized at motor nerves and PAC1 receptors placed at sensory nerves and coupled to NO release, seem also to be involved in the VIP and PACAP 38 relaxations.

British Journal of Pharmacology (2004) 141, 123–131. doi:10.1038/sj.bjp.0705582