showing 36 of ~574560 from 574555 documents
Model independent Higgs boson mass limits at LEP
1993
We derive model-independent constraints on Higgs mass and couplings from associated signals for higher masses, accessible at LEP2. This work is motivated by the fact that, in many extensions of the standard model, the Higgs boson can have substantial "invisible" decay modes, for example, into light or massless weakly interacting Goldstone bosons associated to the spontaneous violation of lepton number below the weak scale.
In vivo delivery of human alpha 1-antitrypsin gene to mouse hepatocytes by liposomes.
1993
The pTG7101 plasmid containing the full length human alpha 1-Antitrypsin was encapsulated in large (142 +/- 15 nm of diameter) and small (54 +/- 11 nm of diameter) liposomes and administered i.v. to mice (80 ng/mouse). Control animals were treated with empty (small and large) liposomes plus free DNA and with the liposome solvent buffer. The immunohistochemical results on liver cryosections and cytophotometric analysis of hepatocyte chromophore absorbance, after peroxidase reaction, indicated that significant presence of immunoreactive human alpha 1-antitrypsin was present 7 days after mice treatment with encapsulated DNA in small liposomes but not when large liposomes were used. This effect…
Role of thyroid state on induction by ciprofibrate of laurate hydroxylase and peroxisomal enzymes in rat liver microsomes.
1993
The effects of hypothyroidism and hyperthyroidism upon liver microsomal omega-laurate hydroxylase activity (cytochrome P450 IV A1-dependent), peroxisome proliferation marker enzyme activities and acyl CoA oxidase (AOX) expression induced by ciprofibrate (2 mg/kg/day during 8 days) were studied in the male Wistar rat so as to clarify firstly the possible involvement of thyroid hormones in the modification of peroxisomal ciprofibrate-induced enzyme activities in relation to hepatic microsomal cytochrome P450 IV A1 induction, and secondly the possible direct effect of thyroid hormones on the gene expression of specific peroxisomal enzymes. No significant change was found in the ciprofibrate-in…
Fractal structures and environmental regulations in urban growth
1993
Unusual business or business as usual: An investigation of meeting support requirements in multilateral diplomacy
1993
Abstract The concept of supporting meetings at the same time and at the same place with computers raises the problem of how salient features of group behaviors are understood in meetings. In this paper we critically examine some aspects of meeting behaviors. We point out that the idea of small, cohesive business teams is not necessarily a valid starting point in thinking of all meeting support. In particular, beliefs that relate to user aspects, group features such as composition, structure and protocols, and task characteristics such as nature, importance, and goals in meetings may need deliberation in many group decision support systems (GDSS) interventions. To demonstrate the credibility…
Concerning“An Opinion on the Heterogeneous Photoreduction of N2 with H2O”: Second Letter
1993
UNA RARA INDICAZIONE ALLA LOBECTOMIA DEL NEONATO: L'Emangioendotelioma complicato
1993
L'Emangioendotelioma epatico (EEE) è un raro tumore benigno vascolare dell'età pediatrica di maggiore riscontro nella prima infanzia, periodo durante il quale può essere causa di notevoile morbilità e mortalità per le temibili complicanze possibili. Gli Autori presentano un caso di EEE nel neonato, occorso alla loro osservazione e discutono le problematiche relative alla diagnosi ed al trattamento
Single particle jumps and correlated ionic motions in glass-ceramics
1993
Using impedance spectroscopy, the ion transport in poorly Li-conducting aluminosilicate glass ceramics and their precursor glasses has been measured for temperatures 50 K < T < 550 K and covering a frequency range of more than 14 decades from 10 mHz up to 3 THz. In addition to the familiar cooperative ionic motion dominating at high temperatures, for the first time dielectric relaxation due to elementary hopping processes is observed well below room temperature.
Roxindole, a dopamine autoreceptor agonist, in the treatment of major depression
1993
Roxindole is a potent autoreceptor-“selective” dopamine agonist originally developed for the treatment of schizophrenic syndromes. The drug also inhibits 5-HT uptake and has 5-HT1A agonistic actions. In this open clinical trial 12 in-patients suffering from a major depressive episode (DSM-III-R) were treated with roxindole for 28 days in a fixed dosage of 15 mg per day. A reduction of at least 50% in HAMD-17 total scores was observed in 8 out of 12 patients after 4 weeks (mean HAMD-17 reduction of 56% in all patients), while 4 patients did not respond to roxindole treatment. Half of the patients showed a complete psychopathological remission (HAMD-17 <8). Roxindole's onset of antidepressant…
From lamps to lasers—Optical spectroscopy of radioactive atoms
1993
Über Tetraaryl-methan-analoga in der gruppe 14
1993
The title compounds have been synthesized by Li and Grignard reactions. The crystal structure of Ph3Si-p-Tol has been determined. The substitution of only one phenyl by one p-tolyl group causes only a slight deviation from the ideal S4 symmetry of Ph4Si. Gradual replacement of phenyl by p-tolyl groups leads to increasing low field shifts for all 13C(ipso) atoms. The substitution of the first phenyl group by p-tolyl in Ph4Si and Ph4Sn results in a high field shift both for δ(29Si) (−0.3 ppm) and for δ(119Sn) (−1 ppm). Further replacement shows nearly linear dependencies (Δδ(29Si) = −0.1 ppm, Δδ(119Sn) = + 1.5 ppm per p-tolyl group).
Conversion and Undiversion Surgery
1993
A model for polybutadiene coatings on porous silica
1993
Non-wetting viscous liquids such as oligobutadiene prefer “active” sites such as pores during the process of physisorption. Thus, polybutadiene (PBD) coatings on porous silica do not result in a homogeneous polymer film but in an inhomogeneous loading where the bulk polymer is mainly sited in the pores of the silica. An increasing polymer loading leads to increasingly filled pores instead of a thicker polymer film. We cannot exclude the possibility that most of the surface is covered at least with a thin polymer film since the chromatographic behaviour is relatively good for polypeptides, which are highly susceptible to the silanol groups of silica.
Response to Anti-human IgE in Human Pulmonary Arteries: Regulation by Endothelium
1993
Initial reports concerning anaphylactic reactions in the lung have demonstrated that histamine is released, and this mediator may be responsible for the severe hypotension observed in vivo in sensitized animals. However, those mechanisms involved in the antigen-vascular interactions have not been elucidated. Human isolated pulmonary arterial preparations relaxed when challenged with anti-human IgE (a-IgE). This response was associated with a release of histamine and PGI2. Both the relaxation and the release of PGI2 were attenuated by removal of the endothelium or by prior treatment of the tissues with chlorpheniramine. Indomethacin also significantly reduced the relaxations produced by a-Ig…
6-phosphofructo-2-kinase/fructose-2,6-bisphosphatase from frog skeletal muscle: purification, kinetics and immunological properties.
1993
Fructose 2,6-bisphosphate is the most potent activator of 6-phosphofructo-1-kinase, a key regulatory enzyme of glycolysis in animal tissues. This study was prompted by the finding that the content of fructose 2,6-bisphosphate in frog skeletal muscle was dramatically increased at the initiation of exercise and was closely correlated with the glycolytic flux during exercise. 6-phosphofructo-2-kinase/fructose-2,6-bisphosphatase, the enzyme system catalyzing the synthesis and degradation of fructose 2,6-bisphosphate, was purified from frog (Rana esculenta) skeletal muscle and its properties were compared with those of the rat muscle type enzyme expressed in Escherichia coli using recombinant DN…
[MnM(egta)]· 8H2O(M= Mn, Cd): A Novel Type of Two-Dimensional Magnetic Lattice
1993
Características petrográficas y geoquímicas de los elementos mayores del Campo Volcánico de Los Tuxtlas, Veracruz, México
1993
El Campo Volcánico de Los Tuxtlas se localiza en la costa del Golfo de México, al oriente del Cinturón Volcánico Mexicano, como unidad volcánica independiente, a unos 300 Km al SE del volcán Citlaltépetl. Está constituido por más de 276 estructuras volcánicas situadas dentro de un área subcircular de 50 Km de diámetro. Este vulcanismo, cuya edad va del Oligoceno al Holoceno, es de tipo explosivo, fisural y de carácter alcalino. Las rocas varían de basanita tefrítica a basalto y excepcionalmente a andesita basáltica. Los análisis de elementos mayores y sus respectivas normas CIPW nos hacen inferir que, salvo a una muestra, se trata de magmas poco diferenciados, con valores de magnesio altos …
Poderes locales, conflictividad y cambio social en la España agraria. Del Antiguo Régimen a la sociedad burguesa
1993
Se analizan los debates y las comunicaciones del VI Seminario de Historia Agraria en la sesión dedicada a los poderes locales en la España del siglo XIX. Se sitúa la discusión en la problemática del cambio social, las actitudes y la conflictividad colectivas. The various discussions and papers from the 4th Seminar on Agrarian History in its meeting about the local authorities in the 19th-century Spain, are discussed. The reflection focusses on the set of problems of the social change, on the collective attitudes, tensions and disputes. jmillan@uv.es
Estimating regional differences in the utilization of labour resources
1993
This paper introduces a method for the analysis of regional differences in the utilization of labour resources. The method developed is a version of ‘components-of-change’ analysis in which labour force utilization in each regional labour market is compared with the sitation of a labour market with the highest level of utilization. The aggregate measure is split up into three components: open (registered) unemployment, hidden unemployment and underemployment. The effects of structural factors on aggregate differences are also estimated. In the empirical section the situation of Finnish provinces in 1989 is analysed within the framework developed. The results indicated the existence of large…
Ecotoxicological studies with the freshwater rotifer Brachionus calyciflorus II. An assessment of the chronic toxicity of lindane and 3,4-dichloroani…
1993
The effects of chronic exposure of the freshwater rotifer Brachionus calyciflorus to the toxicants lindane and 3,4-dichloroaniline (DCA), were evaluated. The parameters used to determine the toxicity on these compounds were the age-specific and fertility, and the demographic parameters: intrinsic rate of natural increase (r), generation time (T), net reproductive rate (Ro), reproductive value (Vx) and life expectancy (eo). All the demographic parameters studied decreased with increasing toxicant concentrations. The use of life tables techniques with B. calyciflorus as a test method for the determination of chronic toxicity of xenobiotics is discussed.
Development of type-specific and cross-reactive serological probes for the minor capsid protein of human papillomavirus type 33.
1993
Human papillomavirus type 33 (HPV33) is associated with malignant tumors of the cervix. In an attempt to develop immunological probes for HPV33 infections, antisera against various bacterial fusion proteins carrying sequences of the minor capsid protein encoded by L2 were raised in animals. Antigenic determinants on the HPV33 L2 protein were identified by using truncated fusion proteins and were classified as type specific or cross-reactive with respect to HPV1, -8, -11, -16, and -18. Cross-reactive epitopes map to amino acids 98 to 107 or to amino acids 102 to 112 and 107 to 117, respectively, depending on the fusion protein used for immunization. Antibodies directed toward these epitopes …
MR-tomographische Funktionsanalyse des linken Ventrikels
1993
The following contribution presents a continuous MRT analysis of the contraction and relaxation processes of healthy left ventricles giving reference values for contraction and relaxation velocities. For the total ventricle we have Vsyst. r. total = 342 +/- 47% LVEDV/sec and Vdiast. r. total = 303 +/- 59% LVEDV/sec. In relation to the end-diastolic (tomographic) volume (EDSV) significantly greater changes in volume per unit of time were measured apically compared to basal (systolic: 411 +/- 89% EDSV/sec apical vs 261 +/- 35% EDSV/sec basal; diastolic: 810 +/- 145% EDSV/sec apical vs 245 +/- 70% EDSV/sec basal). Occurrence of the end-systolic minimal volumes of apical tomographic layers was …
Organochromium complexes - labelled aminoglycoside antibiotics derived from kanamycin A and tobramycin. Synthesis, structural characterization and us…
1993
Abstract The synthesis of metallocenic derivatives of aminoglycoside antibiotics, i. e. kanamycin A and tobramycin, is described. The organometallic-labelled compounds have been obtained from the reaction between the polyaminodrugs and organochromium esters of N-hydroxysuccinimide. The reaction proceeded selectively at the 6′-N position, as might be deduced both from the mass and the pH-dependent 13 C-NMR spectra. The procedure could be regarded as generally useful for the metallolabelling of aminoglycoside antibiotics. As an example of application a competitive immunoassay based on the use of these labels is proposed.
Concerning“An Opinion on the Heterogeneous Photoreduction of N2 with H2O”: First Letter
1993
Retinopathy of prematurity-current diagnosis and management
1993
Despite advances in ophthalmological care of premature infants, retinopathy of prematurity (ROP) remains a still unsolved problem for paediatricians as well as ophthalmologists. A survey of the current literature concerning drug therapy and surgical management as related to the different stages of ROP is given. The classification system for ROP according to the International Committee is presented as well as our screening policy in relation to the literature. The effectiveness in preventing severe cases of ROP and the toxicity of vitamin E supplementation in high-risk premature infants is still disputed and no recommendations can be given. Cryotherapy is recommended in symmetric cases of st…
Effects of gemfibrozil in hyperlipidemic patients with or without diabetes
1993
Abstract Four hundred sixty-one hyperlipidemic men and women, aged 23 to 73 years, with (n = 200) or without (n = 261) non-insulin-dependent diabetes mellitus were included in a study designed to evaluate the efficacy and tolerability of 1,200 mg of gemfibrozil given once daily for 24 weeks. All lipid values improved significantly in both diabetic and nondiabetic patients during treatment. The number of patients with the atherogenic predictor ratio of low-density:high-density lipoprotein cholesterol (HDL-C:LDL-C) >5 decreased by 95% in both patient groups. The number of patients in the highest-risk subgroup with the combination risk factors of LDL-C:HDL-C >5 and triglyceride levels >200 mg/…
Age-related changes in delta 6 and delta 5 desaturase activities in rat liver microsomes.
1993
Age-related changes in Δ6 desaturation of [1-14C]α-linolenic acid and [1-14C]linoleic acid and in Δ5 desaturation of [2-14C]dihomo-γ-linolenic acid were studied in liver microsomes from Wistar male rats at various ages ranging from 1.5 to 24 mon. Desaturase activities were expressed both as specific activity of liver microsomes and as the capacity of whole liver to desaturate by taking into account the total amount of liver microsomal protein. Δ6 Desaturation of α-linolenic acid increased from 1.5 to 3 mon and then decreased linearly up to 24 mon to reach the same desaturation capacity of liver measured at 1.5 mon. The capacity of liver to desaturate linoleic acid increased up to 6 mon and …
Organometallic complexes with biological molecules. I. Diorganotin(IV)chloro protoporphyrin IX complexes: Solid-state and solution-phase characteriza…
1993
Protoporphyrin IX (H4PPIX) complexes of diorganotin(IV)chloro moieties with formula (R2SnCl)2H2PPIX (RMe, Bu and Ph) have been obtained and their solid-state and solution-phase configurations have been studied through spectroscopic investigations. Coordination of the side-chain carboxylates of H4PPIX to R2Sn(IV)Cl moieties, with bridging carboxylate (COO−) has been inferred by comparison of the free and coordinated H4PPIX IR spectra, while the occurrence of a five-coordinated tin(IV) atom in a cis-R2 trigonal bipyramidal structure has been deduced, for all of the synthesized complexes, by rationalization of the nuclear quadrupole splitting parameters, according to the point-charge model for…
Low target birth weight or growth retardation? Umbilical Doppler flow velocity waveforms and histometric analysis of fetoplacental vascular tree
1993
Objective: The placental vascular architecture of small-for-gestatonal-age fetuses seems to have an impact on the flow patterns in the umbilical arteries. Study Design: Blood flow velocity waveforms of the umbilical arteries were measured by Doppler ultrasonography in nine small-for-gestational-age fetuses with elevated systolic/diastolic ratios of the umbilical arteries, seven small-for-gestational-age fetuses with normal flow patterns, and 14 appropriate-for-gestational-age fetuses with normal flow patterns. After delivery histomorphometric placental investigations were performed. Results: Reduced end-diastolic flow velocities were significantly associated with both a reduction of vascula…
Schizophrenia and left hemisphere dysfunctions a controlled neuropsychological study in schizophrenics and their relatives
1993
The impact of gender and age at onset on the familial aggregation of schizophrenia.
1993
Some recent family studies have shown that the familial risk for schizophrenia is higher in female than in male schizophrenics. It is debated whether the risks for the other disorders, such as schizotypal personality disorder or affective disorders in families of schizophrenics are similarly influenced by the proband's gender. Also, the reason for the effect of proband's gender on the recurrence risk for schizophrenia has not been clarified. This family study (159 probands, 589 first degree relatives) confirms that schizophrenia, but also schizophrenia spectrum disorders were more frequent in families of female compared with male schizophrenics. Neither age at onset in probands nor the inte…
Immunoblotting as a confirmatory test for antimitochondrial antibodies in primary biliary cirrhosis.
1993
Primary biliary cirrhosis is characterised by the presence of antimitochondrial antibodies which are directed against components of mitochondrial dehydrogenase complexes. The specificity of antimitochondrial antibodies for primary biliary cirrhosis as detected by immunoblotting was investigated. Commercially available preparations of pyruvate and oxo-glutarate dehydrogenases and beef-heart mitochondria were used as source of antigens. Sera from 47 primary biliary cirrhosis patients (46 of whom were antimitochondrial antibody positive by immunofluorescence), 16 non-primary biliary cirrhosis patients (antimitochondrial antibody positive by immunofluorescence), 23 liver-kidney microsomal antib…
On the scavenging of SO2 by large and small rain drops: V. A wind tunnel and theoretical study of the desorption of SO2 from water drops containing S…
1993
An experimental and theoretical study has been carried out to investigate the rate of desorption of SO2 from water drops falling at terminal velocity in air. The experiments were carried out in the Mainz vertical wind tunnel in which water drops of various sizes containing S(IV) in various concentrations were freely suspended in the vertical airstream of the tunnel. The results of these experiments were compared with the predictions of three theoretical models, and with the experiments of Walceket al. This comparison shows that the predictions of the diffusion model of Kronig and Brink in the formulation given by Walcek and Pruppacher agree well with the experimental results for all relevan…
Factors related to coping with physical and instrumental activities of daily living among people born in 1904-1923
1993
Functional ability is affected by a number of different factors, including biological ageing, illness, and living environment. This study was concerned with the connections of functional ability with mood and cognitive capacity in elderly individuals. It forms part of a cross-sectional study which was carried out in 1988, involving two random samples of 800 non-institutionalized persons born in 1904–1913 and 1914–1923. Functional ability tests included 18 questions; eight concerned coping with physical activities of daily living (PADL) and 10 instrumental activities of daily living (IADL). Depressive symptoms and cognitive capacity were examined by tests. In addition, there was a set of que…
The ultrastructure of articular cartilage of the chicken's knee joint
1993
The articular cartilage and synovial membrane of immature and mature chicken knee joints were studied by light, scanning and transmission microscopy. The findings differed from human articular cartilage and we conclude that the chicken knee joint is not suitable as a model for human joint degeneration.