bluuebunny/crossref_metadata_2025_split huggingface dataset:
Preparation, structure, and reactivity of a new heterocyclic system‐1‐thio‐2,8‐diphenyl‐2,5,8‐triaza‐1λ5‐phosphabicyclo[3.3.0]octane
Authors: Laurens Susan , Ichharam Vimal V. H. , Modro Tomasz A. 
Published: September 2002

AbstractA new heterocyclic system, 1‐thio‐2,8‐diphenyl‐2,5,8‐triaza‐1λ5‐phosphabicyclo[3.3.0]octane, has been prepared, and its structure was confirmed by single‐crystal X‐ray diffraction. Preliminary reactivity studies demonstrated a complex mechanism for the acid‐catalyzed methanolysis. Gas chromatography–mass spectrometry analysis indicates a reversible substitution leading to the monocyclic, eight‐membered product, followed by two rearrangement reactions: isomerization to the 1,3,2‐diazaphosphorinane derivative, and to the SMe thioester via the oxygen → sulfur migration of the methyl group. © 2001 John Wiley & Sons, Inc. Heteroatom Chem 12:327–332, 2001
π‐facial diastereoselection of hydride reduction of 1,3‐diheteran‐5‐ones: application of the exterior frontier orbital extension model
Authors: Kaneno Daisuke , Zhang Jian , Iwaoka Michio , Tomoda Shuji 
Published: September 2002

AbstractTo obtain further evidence for the importance of the ground state conformational and orbital properties in π‐facial diastereoselection of 1,3‐diheteran‐5‐ones (heteroatom = O, S, Se), 2‐phenyl‐1,3‐diselenan‐5‐one (3a) has been synthesized, and its π‐facial diastereoselection upon hydride reduction has been examined. The experimental data of π‐facial stereoselection of 3a has been successfully rationalized by the exterior frontier orbital extension model (the EFOE model). Intrinsic reaction coordinate (IRC) and natural bond orbital (NBO) analyses of transition states of LiAlH4 reduction of this ketone have strongly indicated that the transition state effects (the torsional strain of the carbonyl moieties and the antiperiplanar effects involving the incipient bond proposed by the conventional theoretical models for π‐facial diastereoselection; the Felkin‐Anh model and the Cieplak model) are not responsible for facial selection. © 2001 John Wiley & Sons, Inc. Heteroatom Chem 12:358–368, 2001
Preparation, structure, and reactivity of pentacoordinate disilanes bearing an 8‐charcogeno‐1‐naphthyl group and a heteroatom on the same silicon atom
Authors: Toshimitsu Akio , Hirao Shino , Saeki Tomoyuki , Asahara Masahiro , Tamao Kohei 
Published: September 2002

AbstractThe pentacoordinate disilanes bearing an 8‐chalcogeno‐1‐naphthyl group and an ethoxy group (or a fluorine atom) on the same silicon center are found to be thermally stable, in sharp contrast to the thermal lability of the analogous disilanes coordinated by the group 15 elements, such as nitrogen and phosphorus, to α‐elimination of the ethoxysilane (or fluorosilane) to generate the base‐coordinated silylenes. As the reasons for this different behavior, two possibilities are pointed out as follows: (1) the nitrogen‐coordinated disilanes are destabilized due to the distortion of the naphthyl moiety, and (2) silylenes are more stabilized by coordination with the group 15 elements than with the group 16 elements. © 2001 John Wiley & Sons, Inc. Heteroatom Chem 12:392–397, 2001
Synthesis, characterization, and photoreactions of 1,2‐disiladigermacyclobutane
Authors: Hashimoto Hisako , Yagihashi Yusuke , Ignatovich Lubov , Kira Mitsuo 
Published: September 2002

AbstractA new four‐membered ring compound having a Si2Ge2 skeleton, octaisopropyl‐1,2‐disiladigermacyclobutane (1), was synthesized by the reductive coupling of tetraisopropyl‐1,2‐dichlorosilagermane with sodium in toluene. The structure of 1, which has one Ge–Ge bond, one Si–Si bond, and two Ge–Si bonds in a ring, was confirmed by chemical derivatization; the reactions of 1 with m‐chloroperoxybenzoic acid and PCl5 led to the selective cleavage of the Ge–Ge bond in 1. The selective extrusion of a germylene from 1 was observed at the initial stage of the photolysis using 254 nm light. © 2001 John Wiley & Sons, Inc. Heteroatom Chem 12:398–405, 2001
A discrete random effects probit model with application to the demand for preventive care
Authors: Deb Partha 
Published: September 2002

AbstractI have developed a random effects probit model in which the distribution of the random intercept is approximated by a discrete density. Monte Carlo results show that only three to four points of support are required for the discrete density to closely mimic normal and chi‐squared densities and provide unbiased estimates of the structural parameters and the variance of the random intercept. The empirical application shows that both observed family characteristics and unobserved family‐level heterogeneity are important determinants of the demand for preventive care. Copyright © 2001 John Wiley & Sons, Ltd.
GABAergic control of synaptic summation in hippocampal CA1 pyramidal neurons
Authors: Enoki Ryosuke , Inoue Masashi , Hashimoto Yoshinori , Kudo Yoshihisa , Miyakawa Hiroyoshi 
Published: September 2002

AbstractThe primary function of neurons is to integrate synaptic inputs and to transmit the results to other cells. It was shown previously that separate excitatory inputs to hippocampal pyramidal neurons are summated nonlinearly. In the hippocampus, responses of pyramidal neurons are influenced by GABAergic inputs in feed‐forward or feedback manner, and also by oscillatory network activities. It is likely that these GABAergic inputs regulate the way synaptic inputs are summated. To examine the roles of GABAergic inputs on synaptic summation, we made whole‐cell recordings from the cell bodies of CA1 pyramidal neurons in rat hippocampal slices while stimulating two independent input pathways with short interstimulus intervals, and examined the manner by which postsynaptic potentials were summated. We found that: 1) the summation of the perforant pathway and the Schaffer collateral pathway inputs was sublinear when the interval between two inputs was shorter than 30 ms, 2) the blockade of GABAA receptors partially suppressed the sublinearity, and 3) further blockade of GABAB receptors removed the sublinearity totally. We also found that 4) the summation was superlinear under the concomitant blockade of GABAA and GABAB receptors when the two inputs arrived with no delay. Thus our study demonstrates that GABAergic inputs are responsible for keeping the summation of two separate inputs on CA1 pyramidal neurons sublinear. Hippocampus 2001;11:683–689. © 2001 Wiley‐Liss, Inc.
Involvement of noradrenergic innervation from locus coeruleus to hippocampal formation in negative feedback regulation of penile erection in the rat
Authors: Chang Alice Y.W. , Huang Chun‐Ming , Chan Julie Y.H. , Chan Samuel H.H. 
Published: September 2002

AbstractWe demonstrated previously that a novel negative feedback mechanism for the regulation of penile erection, which is triggered by ascending sensory inputs initiated by tumescence of the penis, exists in the hippocampal formation (HF). This study further elucidated the role of the locus coeruleus (LC), which is the largest aggregate of norepinephrine‐containing neurons in the brain and provides the major noradrenergic innervation to the HF, in this process. Adult male Sprague‐Dawley rats that were anesthetized and maintained with chloral hydrate were used. The intracavernous pressure (ICP) recorded from the corpus cavernosum of the penis was used as the experimental index for penile erection. Electrical activation of the LC elicited a significant reduction in baseline ICP. Similar observations were obtained on microinjection bilaterally into the hippocampal CA1 or CA3 subfield or dentate gyrus of equimolar doses (5 nmol) of norepinephrine (α1‐, α2‐agonist), phenylephrine (α1‐agonist), or BHT 933 (α2‐agonist). Bilateral electrolytic lesions of the LC discernibly enhanced the magnitude and/or duration of the elevation in ICP induced by intracavernous administration of papaverine (400 μg). A potentiation of the papaverine‐evoked ICP increase was also observed following pretreatment with bilateral hippocampal application of equimolar doses (250 pmol) of either prazosin (α1‐, α2B‐, α2C‐antagonist), naftopidil (α1A/D‐antagonist), yohimbine (α2‐antagonst), or rauwolscine (α2B‐, α2C‐antagonist). None of these antagonists, however, affected baseline ICP. These results suggest that noradrenergic innervation of the HF that originates from the LC may play an active role in negative feedback regulation of penile erection, engaging at least α1A/D‐, α2B‐, and α2C‐adrenoceptors in the HF. Hippocampus 2001;11:783–792. © 2001 Wiley‐Liss, Inc.
Expanding the horizons of depression: beyond the monoamine hypothesis
Authors: Hindmarch I. 
Published: September 2002

AbstractThe monoamine hypothesis has dominated our understanding of depression and of pharmacological approaches to its management and it has produced several generations of antidepressant agents, ranging from the monoamine oxidase inhibitors (MAOIs), through tricyclics (TCAs) and selective serotonin reuptake inhibitors (SSRIs), to the recently introduced selective noradrenaline reuptake inhibitor (NARI), reboxetine. Greater receptor selectivity has improved tolerability, but not efficacy, when newer compounds are compared with the original tricyclic antidepressants (TCAs) and monoamine oxidase inhibitors. Essentially, the newer antidepressants have the same distinguishing feature as older ones, i.e. acute enhancement of monoaminergic neurotransmission. The monoamine hypothesis cannot conclusively link the acute biochemical action of antidepressants on monoamine levels with their delayed clinical effect of 10–14 days, nor can it explain the mode of action of antidepressants that are effective despite being very weak inhibitors of monoaminergic transmission (e.g. iprindole) or, incongruously, enhancing monoamine uptake (e.g. tianeptine). Compared with other fields of medicine, there has been a lack of progress in understanding the pathophysiology of depression and producing truly novel antidepressant agents. Other biological approaches to depression, such as overactivity of the hypothalamic–pituitary–adrenal axis, hippocampal neural plasticity in response to stress, and the link between the inflammatory response and depression, offer new approaches to finding pharmacological agents, aided by improved techniques for visualising the human brain, better animal models, and increased knowledge of human markers of depression. Copyright © 2001 John Wiley & Sons, Ltd.
Role of within‐lake processes and hydrobiogeochemical changes over 16 years in a watershed in the Adirondack Mountains of New York State, USA
Authors: Mitchell Myron J. , McHale Patrick J. , Inamdar Shreeram , Raynal Dudley J. 
Published: September 2002

AbstractHydrological and biogeochemical relationships were evaluated for the Arbutus Watershed in the Adirondack Mountains of New York State. Wet‐only precipitation inputs (weekly) and discharge losses were evaluated from 1983 to 1998. Precipitation from 1983–98 had significant (p<0·05) decreases in concentrations of Ca2+(−0·10µmolcl−1year−1), Mg2+(−0·07µmolcl−1year−1), K+(−0·01µmolcl−1year−1), Na+(−0·04µmolcl−1year−1), Cl−(−0·07µmolc l−1year−1), SO42−(−0·82µmolcl−1year−1) and H+(−0·55µmolcl−1year−1), whereas NH4+ and NO3− concentrations did not change.For the same period, there were decreases in solute concentrations in the Arbutus Lake outlet for Ca2+(−1·18µmolcl−1year−1), Mg2+(−0·32µmolcl−1year−1), K+(−0·33µmolcl−1year−1), Cl−(−0·17µmolcl−1year−1) and SO42−(−1·90µmolcl−1year−1) and a significant increase in NH4+ concentrations (+0·07µmolcl−1year−1). For the period from 1995 through 1998 the discharge measurements for the outlet and the major inlet of Arbutus Lake were combined with weekly chemical measurements supplemented with storm sampling. At the inlet there were significant relationships (p<0·05) between discharge rates and the concentrations of all solutes except Cl−, but only for Na+, NO3−, H+ and Al did these relationships explain more than 20% of the variation in solute concentrations. April had the greatest rates of discharge and solute flux of any month due to spring snowmelt. The dormant season (October–May) accounted for >80% of the discharge in the inlet and outlet of Arbutus Lake and >78% of the flux of all solutes. For 1995–98 the mass balances of discharge losses from the catchment draining into Arbutus Lake inlet versus precipitation inputs suggest that internal watershed processes resulted in net generation of Ca2+(−1342molcha−1year−1), Mg2+(−313molcha−1year−1), K+(−35molcha−1year−1), SO42−(−635molcha−1year−1) and Cl−(−45molcha−1year−1) and net retention of inorganic N solutes (NO3−+NH4+: 204 molc ha−1 year−1) and H+(424molcha−1year−1). Concentrations and fluxes of Ca2+, H+, NO3−, SO42− and Al were lower at the lake outlet compared with the inlet. A comparison of mass balances at the Arbutus Lake inlet and outlet suggested that these decreases may have been due to within‐lake biotic processes and/or dilution from other water sources to the lake. Copyright © 2001 John Wiley & Sons, Ltd.
The effect of physician advice on alcohol consumption: count regression with an endogenous treatment effect
Authors: Kenkel Donald S. , Terza Joseph V. 
Published: September 2002

AbstractAlthough there are encouraging trends, alcohol abuse continues to be a significant public health problem. Econometric studies of alcohol demand have yielded a great deal of information for alcohol abuse prevention policy. These studies suggest that higher alcohol taxes and stricter drunk‐driving policies can reduce heavy drinking and drunk driving. In this paper we explore the role physician advice plays in the campaign to prevent alcohol‐related problems. Compared to alcohol taxation, physician advice is a more precisely targeted intervention that does not impose extra costs on responsible drinkers. Compared to the resource costs of arresting, processing, and punishing drunk drivers, physician advice may be a lower‐cost intervention. To provide a basis for alcohol policy analysis, we use an alcohol demand framework to test whether physician‐provided information about the adverse consequences of alcohol abuse shifts demand to more moderate levels. There are three aspects of our alcohol demand model that complicate the estimation: (1) the dependent variable is non‐negative (it is a count variable—number of drinks consumed); (2) a non‐trivial number of sample observations have zero values for the dependent variable; and (3) because the data we use is non‐experimental, the treatment variable indicating receipt of advice from a physician may be endogenous. We implement an estimation method that is specifically designed to deal with these three complicating factors. Our results show that advice has a substantial and significant impact on alcohol consumption by males with hypertension, and that failing to account for the endogeneity of advice masks this result. Copyright © 2001 John Wiley & Sons, Ltd.
Toxicokinetics of bromodichloroacetate in B6C3F1 mice
Authors: Merdink J. L. , Bull R. J. , Schultz I. R. 
Published: September 2002

AbstractThe oral and i.v. elimination kinetics were investigated for bromodichloroacetate (BDCA), a haloacetate found in drinking water. The BDCA was administered at a dose of 5, 20 and 100 mg kg−1 to B6C3F1 mice and appears to distribute to the total body water with a mean volume of distribution of 427 ± 79 ml kg−1. It is subject to first‐pass hepatic metabolism with a range of bioavailabilities of 0.28–0.73. A mean terminal half‐life of 1.37 ± 0.21 h. was calculated from the two lower doses of both i.v. and oral administration. Non‐linear behavior was exhibited at doses greater than 20 mg kg−1, with a much higher than expected area under the curve (AUC), a decrease in total body clearance (CLb) and an increase in the terminal half‐life to 2.3 h at the highest dose. The average CLb was 220 ml h−1 kg−1 for the lower two doses but decreased to 156 ml h−1 kg−1 at the high dose. The BDCA is primarily eliminated by metabolism, with only 2.4% of the parent dose being recovered in the urine at the high dose. The unbound renal clearance, as calculated from the high dose, was 15.0 ml h−1 kg−1. The BDCA is moderately bound to plasma proteins (fu = 0.28) and preferentially distributes to the plasma with a blood/plasma ratio of 0.88. Copyright © 2001 John Wiley & Sons, Ltd.
Expression of translation initiation factor IF2 is regulated during osteoblast differentiation
Authors: Weber Janet A. , Gay Carol V. 
Published: September 2002

AbstractWe isolated and characterized a cDNA for the N‐terminal half of the eukaryotic initiation of translation factor 2 (cIF2) during a screen of chicken osteoblast cDNAs. The apparent size of the message for this protein, ∼5.6 kb, is slightly larger in size than that for human IF2 (hIF2). There is a high degree of sequence similarity between the human and chicken N‐terminal portions of the protein that extends to the encoding nucleotide sequence. The tissue specific expression pattern for cIF2 and hIF2 are similar, being moderately abundant in brain, liver, and skeletal muscle, and detectable in kidney, chondrocytes, and freshly isolated osteoblasts. The ratio of message for cIF2 to that of β‐actin was 0.10 and 0.18 for liver and brain. Message levels peak in osteoblasts between 8 and 12 days of culture, coinciding with high levels of matrix protein synthesis. At peak expression, the ratio of cIF2:β‐actin for 8 day osteoblasts was 0.76. Treatment of osteoblast cultures with cycloheximide markedly reduces the level of cIF2 message indicating that novel protein synthesis is required for its expression. Hybridization of RNA samples from either chicken osteoblasts or a human osteoblast cell line with a probe for a subunit of human eukaryotic initiation of translation factor 2 (eIF2α), the housekeeping initiation factor, indicates that levels of eIF2 remain low. With hIF2, cIF2 represents the only other vertebrate homolog of IF2 for which a major portion of the coding sequence has been identified. This is the first report of regulated expression for a eukaryotic IF2 and is the first demonstration of its abundance in osteoblasts. J. Cell. Biochem. 81: 700–714, 2001. © 2001 Wiley‐Liss, Inc.
Prenatal sonographic diagnosis of adrenal neuroblastoma
Authors: Grandó Alvaro , Monteggía Vicente , Gandara Carlos , Ruano Rodrigo , Bunduki Victor , Zugaib Marcelo 
Published: September 2002

AbstractNeuroblastoma is the most frequent extracranial solid tumor in childhood, but it is seldom diagnosed prenatally. We report a case of adrenal neuroblastoma identified at 39 weeks' menstrual age and successfully treated by postnatal surgery and chemotherapy. Sonography revealed a hyperechoic mass in the right upper quadrant of the fetal abdomen associated with hydramnios and hydronephrosis. Two days after delivery, the tumor was resected. No metastasis was identified. The infant received 6 cycles of chemotherapy, and at 2 years of age she was well, with no signs of recurrence. © 2001 John Wiley & Sons, Inc. J Clin Ultrasound 29:250–253, 2001.
Sonographic diagnosis of ascaris‐induced cholecystitis and pancreatitis in a child
Authors: Grover Shabnam Bhandari , Pati Nalin K. , Rattan Simmi K. 
Published: September 2002

AbstractWe describe the sonographic diagnosis of ascaris‐induced acute cholecystitis and pancreatitis in a 2‐year‐old girl. Abdominal sonography revealed a grossly distended gallbladder with a thick (0.5‐cm) wall. The common bile duct was dilated to 0.6 cm without sludge or calculi. The pancreas was hypoechoic, with an enlarged, 3.3‐cm pancreatic head. Sonography showed dilatation of the small‐ and large‐bowel loops, with multiple roundworms in duodenal and colonic loops. Sonography has an important role not only in the diagnosis of this uncommon condition but also in the documentation of its unusual etiologic agent. © 2001 John Wiley & Sons, Inc. J Clin Ultrasound 29:254–259, 2001.
Do prostaglandins regulate external gill regression in anurans?
Authors: Warkentin Karen M. , Wassersug Richard J. 
Published: September 2002

AbstractAlthough the endocrinological mechanism controlling regression of the internal, larval gills of anurans &lpar;frogs and toads&rpar; is well understood, the mechanism regulating loss of the external, embryonic gills is not known. Based on the homology of the mammalian ductus arteriosus with a portion of the amphibian branchial arches, and the regulation of blood flow in the mammalian ductus by prostaglandins of the E family &lpar;PGEs&rpar;, we hypothesized that anuran external gill loss is also regulated by PGEs. To test this hypothesis, we topically applied both PGE2 and a synthetic analogue of PGE1, misoprostol, to embryos and young hatchlings of the red&hyphen;eyed treefrog, Agalychnis callidryas. Both agents accelerated external gill regression. Furthermore, misoprostol overrode the inhibitory effect of hypoxia on gill regression in hatchlings and induced rapid loss of external gills in embryos, which normally maintain the gills until hatching. These observations support the hypothesis that PGEs regulate anuran external gill loss. The specific site of action for prostaglandins within the gills is not known; however, PGEs are secreted in the oral mucus of tadpoles, and this could be a natural topical source for these agents. PGEs offer a tool for manipulation of external gills and should facilitate tests of the physiological importance of these structures. J. Exp. Zool. 289:366&ndash;373, 2001. &copy; 2001 Wiley&hyphen;Liss, Inc.
Growth, feeding frequency, protein turnover, and amino acid metabolism in European lobster Homarus gammarus L.
Authors: Mente Eleni , Houlihan Dominic F. , Smith Kerry 
Published: September 2002

AbstractThe effect of feeding frequency on growth and protein metabolism in the European lobster, Homarus gammarus, was investigated. Fourth (IV) stage lobsters H. gammarus were fed individually a marine animal meal (herring/mussels meal) for 56 days. Feeding a daily ration equivalent to 10% of their body weight gave better growth than feeding daily rations of 5% and 20%. Protein synthesis rates were similar for the three food rations but protein growth rates were significantly lower and protein degradation rates highest in the 5% body weight per day ration group. The efficiency with which synthesised protein was retained as growth was found to be 38% in the in the 10% ratio group. Protein synthesis rates of lobsters were found to be lower than those for shrimps (Penaeus vannamei). The amino acid flux also suggests a lower protein conversion efficiency than shrimps P. vannamei. The results suggests that lobsters are slow, periodic feeders and that growth can be readily increased by manipulation of particular environmental factors such as feeding frequency. J. Exp. Zool. 289:419–432, 2001. © 2001 Wiley‐Liss, Inc.