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Entangled spin states are created by implanting muons into single-crystal LiY_{0.95}Ho_{0.05}F_{4} to form a cluster of correlated, dipole-coupled local magnetic moments. The resulting states have well-defined energy levels allowing experimental manipulation of the state populations by electromagnetic excitation. Experimental control of the evolution of the muon spin polarization is demonstrated through application of continuous, radio-frequency electromagnetic excitation fields. A semiclassical model of quantum, dipole-coupled spins interacting with a classical, oscillating magnetic field accounts for the muon spin evolution. On application of the excitation field, this model shows how changes in the state populations lead to the experimentally observed effects, thus enabling a spectroscopic probe of entangled spin states with muons.
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Magnetic bistability in single-molecule magnets (SMMs) is a potential basis for new types of nanoscale information storage material. The standard model for thermally activated relaxation of the magnetization in SMMs is based on the occurrence of a single Orbach process. Here, we show that incorporating a phosphorus atom into the framework of the dysprosium metallocene [(CpiPr5)Dy(CpPEt4)]+[B(C6F5)4]- (CpiPr5 is penta-isopropylcyclopentadienyl, CpPEt4 is tetraethylphospholyl) leads to the occurrence of two distinct high-temperature Orbach processes, with energy barriers of 1410(10) and 747(7) cm-1, respectively. These barriers provide experimental evidence for two different spin-phonon coupling regimes, which we explain with the aid of ab initio calculations. The strong and highly axial crystal field in this SMM also allows magnetic hysteresis to be observed up to 70 K, using a scan rate of 25 Oe s-1. In characterizing this SMM, we show that a conventional Debye model and consideration of rotational contributions to the spin-phonon interaction are insufficient to explain the observed phenomena.
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BACKGROUND: Children's hospices provide a range of services for babies, children and young people who have a life-limiting or life-threatening condition, including care after death in specialist 'cool bedrooms'. Care after death is a challenging but important element of hospice care. AIM: The aims of the study were to identify the practices of staff providing care after death in UK children's hospices, notably their moving and handling practices and their management of physiological deterioration, and to produce recommendations that promote safe and consistent practice in moving and handling and in managing physiological deterioration after death in UK children's hospices. METHOD: An electronic survey was sent to all 54 UK children's hospices. Free-text responses were analysed using deductive content analysis and used to add depth to the quantitative findings. FINDINGS: Out of 54 children's hospices, 33 responded to the survey. There were great variations in the way hospices delivered care after death, notably in length of stay, interventions and equipment. The lack of consistent practice grounded in evidence-based policy and training may mean that some staff experience higher levels of stress and anxiety than others and that some staff take risks when providing care after death, particularly to express empathy towards bereaved families. CONCLUSION: Recommendations are made about moving and handling a child's body after death and managing its physiological deterioration. Hospices can use these recommendations to develop policy and training, standardise what is expected of staff and support practitioners in adequately caring for children after death.
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Cuidados Paliativos al Final de la Vida , Hospitales para Enfermos Terminales , Adolescente , Niño , Humanos , Cuidados Paliativos , Encuestas y CuestionariosRESUMEN
Hospices for children and adolescents in the United Kingdom provide care to the bodies of deceased children in specially designed chilled bedrooms called "cool rooms." In an effort to develop resources to support hospice practitioners to provide this specialist area of care, this study aimed to identify the factors that influence decision making when moving and handling children's bodies after death in a hospice cool bedroom. An internet-based survey was sent to all practitioners employed by 1 children's hospice. A total of 94.9% of eligible staff responded (n = 56). An inductive approach to thematic analysis was undertaken, using a 6-phase methodological framework. Three core themes were identified that inform practitioners' perception of the appropriateness of moving and handling decisions: care of the body, stages of care, and method of handling. The complexity of decision making and variation in practice was identified. Practitioners relied on both analytical and initiative decision making, with more experienced practitioners using an intuitive approach. Evidence-based policy and training influence the perception of appropriateness and the decisions and behavior of practitioners. The development of a policy and education framework would support practitioners in caring for children's bodies after death, standardizing expectations and measures of competence in relation to moving and handling tasks.
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Cuidados Paliativos al Final de la Vida , Hospitales para Enfermos Terminales , Adolescente , Niño , Toma de Decisiones , Humanos , Encuestas y Cuestionarios , Reino UnidoRESUMEN
We show that the Fermi surface can survive the presence of extreme compositional disorder in the equiatomic alloy Ni_{0.25}Fe_{0.25}Co_{0.25}Cr_{0.25}. Our high-resolution Compton scattering experiments reveal a Fermi surface which is smeared across a significant fraction of the Brillouin zone (up to 40% of 2π/a). The extent of this smearing and its variation on and between different sheets of the Fermi surface have been determined, and estimates of the electron mean free path and residual resistivity have been made by connecting this smearing with the coherence length of the quasiparticle states.
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CsBi4-x Pb x Te6 is synthesized and the superconductivity associated with the structural transition from Pb substitution is studied. Photoemission spectroscopy measurements are performed in order to elucidate the relationship between the electronic structure and the occurrence of the superconductivity. When Bi is substituted with Pb, an electron doping-like change in the electronic structure is directly observed which is contrary to the naive expectation of hole doping. This observation is consistent with band structure calculations and appears to be a unique characteristic of CsBi4-x Pb x Te6 because of the dissociation of Bi dimers upon Pb substitution. These results indicate that it may be possible to control the electron and hole doping via manipulating the Bi dimers through Pb substitution.
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For the purpose of imaging element- and shell-specific magnetic distributions under high magnetic fields, a scanning soft X-ray microscope has been developed at beamline BL25SU, SPring-8, Japan. The scanning X-ray microscope utilizes total electron yield detection of absorbed circularly polarized soft X-rays in order to observe magnetic domains through the X-ray magnetic circular dichroism effect. Crucially, this system is equipped with an 8â T superconducting magnet. The performance and features of the present system are demonstrated by magnetic domain observations of the fractured surface of a Nd14.0Fe79.7Cu0.1B6.2 sintered magnet.
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The anti-perovskite superconductor MgC0.93Ni2.85 was studied using high-resolution x-ray Compton scattering combined with electronic structure calculations. Compton scattering measurements were used to determine experimentally a Fermi surface that showed good agreement with that of our supercell calculations, establishing the presence of the predicted hole and electron Fermi surface sheets. Our calculations indicate that the Fermi surface is smeared by the disorder due to the presence of vacancies on the C and Ni sites, but does not drastically change shape. The 20% reduction in the Fermi level density-of-states would lead to a significant (~70%) suppression of the superconducting T c for pair-forming electron-phonon coupling. However, we ascribe the observed much smaller T c reduction at our composition (compared to the stoichiometric compound) to the suppression of pair-breaking spin fluctuations.
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Frustrated interactions exist throughout nature, with examples ranging from protein folding through to frustrated magnetic interactions. Whilst magnetic frustration is observed in numerous electrically insulating systems, in metals it is a rare phenomenon. The interplay of itinerant conduction electrons mediating interactions between localised magnetic moments with strong spin-orbit coupling is likely fundamental to these systems. Therefore, knowledge of the precise shape and topology of the Fermi surface is important in any explanation of the magnetic behaviour. PdCrO2, a frustrated metallic magnet, offers the opportunity to examine the relationship between magnetic frustration, short-range magnetic order and Fermi surface topology. By mapping the short-range order in reciprocal space and experimentally determining the electronic structure, we have identified the dual role played by the Cr electrons in which the itinerant ones on the nested paramagnetic Fermi surface mediate the frustrated magnetic interactions between local moments.
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BACKGROUND: The direct cost of excessive alcohol consumption to health services is substantial but dwarfed by the cost borne by the workplace as a result of lost productivity. The workplace is also a promising setting for health interventions. The Preventing Alcohol Harm in Liverpool and Knowsley (PrevAIL) project aimed to evaluate a mechanism for detecting the prevalence of alcohol related liver disease using fibrosis biomarkers. Secondary aims were to identify the additive effect of obesity as a risk factor for early liver disease; to assess other impacts of alcohol on work, using a cross-sectional survey. METHODS: Participants (aged 36-55 y) from 13 workplaces participated (March 2011-April 2012). BMI, waist circumference, blood pressure and self-reported alcohol consumption in the previous week was recorded. Those consuming more than the accepted UK threshold (men: >21 units; female: >14 units alcohol) provided a 20 ml venous blood sample for a biomarker test (Southampton Traffic Light Test) and completed an alcohol questionnaire (incorporating the Severity of Alcohol Dependence Questionnaire). RESULTS: The screening mechanism enrolled 363 individuals (52 % women), 39 % of whom drank above the threshold and participated in the liver screen (n = 141, complete data = 124 persons). Workplaces with successful participation were those where employers actively promoted, encouraged and facilitated attendance. Biomarkers detected that 30 % had liver disease (25 %, intermediate; 5 % probable). Liver disease was associated with the frequency of visits to the family physician (P = 0.036) and obesity (P = 0.052). CONCLUSIONS: The workplace is an important setting for addressing alcohol harm, but there are barriers to voluntary screening that need to be addressed. Early detection and support of cases in the community could avert deaths and save health and social costs. Alcohol and obesity should be addressed simultaneously, because of their known multiplicative effect on liver disease risk, and because employers preferred a general health intervention to one that focused solely on alcohol consumption.
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Alcoholismo/complicaciones , Alcoholismo/epidemiología , Hepatopatías Alcohólicas/diagnóstico , Hepatopatías Alcohólicas/epidemiología , Obesidad/epidemiología , Lugar de Trabajo , Adulto , Consumo de Bebidas Alcohólicas/efectos adversos , Consumo de Bebidas Alcohólicas/epidemiología , Alcoholismo/diagnóstico , Biomarcadores , Estudios Transversales , Diagnóstico Precoz , Femenino , Humanos , Masculino , Persona de Mediana Edad , Salud Laboral , Prevalencia , Factores de Riesgo , Autoinforme , Encuestas y Cuestionarios , Reino Unido/epidemiologíaRESUMEN
BACKGROUND: Plasma low density lipoprotein (LDL) particles vary in size, density, electrical charge and chemical composition. An increased presence of small dense LDL (sdLDL), along with raised triglyceride concentrations and decreased high density lipoprotein (HDL) cholesterol concentrations is commonly known as the atherogenic triad and has been observed in some cases of obesity, principally in Europe and America. This study examines the prevalence of sdLDL in the plasma of an obese (BMI≥25 kg/m2) Thai population. METHODS: Plasma from fasted obese (n=48) and non-obese (n=16) Thai participants was subjected to density gradient ultracentrifugation in iodixanol to separate lipoproteins. Gradients were unloaded top-to-bottom into 20 fractions which were assayed for cholesterol, triglyceride, apo B and apo A-1 to identify lipoprotein types and subtypes. RESULTS: LDL cholesterol was subfractionated into LDL I+II (fractions 3-6, ρ=1.021-1.033 g/ml) which was considered to represent large buoyant LDL (lbLDL), LDL III (fractions 7-9, ρ=1.036-1.039 g/ml) which was considered to represent sdLDL, and, LDL IV (fractions 10-12, ρ=1.044-1.051 g/ml) which was considered to represent very sdLDL. Concentrations of LDL III and IV were increased by 15-20% in obese participants whilst that of LDL I+II was concomitantly decreased by 10%. This was accompanied by a 50% increase in plasma triglyceride concentrations and 15% decrease in HDL cholesterol concentrations. Only 3/16 (19%) non-obese participants had a pattern B LDL cholesterol profile (peak density of >1.033 g/ml), whilst 28/48 (58%) obese participants were pattern B. When expressed as a fraction of the LDL concentration, total sdLDL (i.e. LDL III+IV) showed highly significant correlations to plasma triglyceride concentrations and the triglyceride/HDL cholesterol ratio. CONCLUSIONS: The prevalence of sdLDL is increased in obesity in a Thai population such that they demonstrate a similar atherogenic triad to that previously observed in European and American populations.
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Lipoproteínas LDL/sangre , Obesidad/sangre , Apolipoproteína A-I/sangre , Apolipoproteínas B/sangre , Colesterol/sangre , Femenino , Humanos , Lipoproteínas HDL/sangre , Lipoproteínas LDL/química , Masculino , Persona de Mediana Edad , Tamaño de la Partícula , Prevalencia , Tailandia/epidemiología , Triglicéridos/sangreRESUMEN
A major problem in the serodiagnosis of human toxocariasis in tropical countries is cross-reaction with antibodies to other helminthic diseases and a lack of sensitivity. The majority of tests currently available use total IgG and, in this study, the use of peroxidase-conjugated anti-human IgG subclass antibodies (IgG1-4) was compared with total IgG for the diagnosis of human toxocariasis by using Toxocara excretory-secretory (TES) antigens in an enzyme-linked immunosorbent assay (ELISA) format. All four IgG subclass antibodies gave approximately 10-fold increases in optical density (OD) values for 50 toxocariasis patients compared to 29 healthy normals; this was significantly greater than the approximate doubling of OD values seen in the total IgG-ELISA format. IgG2 gave by far the greatest sensitivity (values: IgG, 50%; IgG1, 60%; IgG2, 98%; IgG3, 78%; IgG4, 64%). Significant cross-reactivity using all IgG subclasses in the TES ELISA was seen with 141 serum samples from patients with 10 other helminthic infections. However, IgG3 gave the best specificity (values: IgG, 73%; IgG1, 76%; IgG2, 71%; IgG3, 81%; IgG4, 71%). Thus, of the IgG subclass antibodies, IgG2 appeared best and employing this subclass can improve the serodiagnosis of human toxocariasis since it recognises carbohydrate epitopes of TES antigens.
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Anticuerpos Antiidiotipos , Antígenos Helmínticos , Ensayo de Inmunoadsorción Enzimática/métodos , Inmunoglobulina G , Toxocara canis/química , Toxocara canis/inmunología , Toxocariasis/diagnóstico , Animales , Anticuerpos Antihelmínticos/sangre , Antígenos Helmínticos/aislamiento & purificación , Reacciones Cruzadas , Humanos , Sensibilidad y Especificidad , Pruebas Serológicas/métodosRESUMEN
Mucobromic and mucochloric acid were used as building blocks for the construction of a chemical combinatorial library of 3,4,5-trisubstituted 2(5H)-furanones. With these 2 butenolide building blocks, and eight alcohols a sublibrary of 16 dihalogenated 5-alkoxy-2(5H)-furanones was prepared. This sublibrary of 5-alkoxylated furanones was reacted with 16 amines generating a full size focussed combinatorial library of 256 individual compounds. This three dimensional combinatorial library of 3-halogen-4-amino-5-alkoxy-2(5H)-furanones was prepared around the benzimida-zolyl furanone lead structure by applying a solution phase combinatorial chemistry concept. Typical representatives of the library were purified and fully characterized and one x-ray structures was recorded, additionally. The 3-bromo-4-benzimizazolyl-5-methoxy-2(5H)furanone, Br-A-l, showed an MIC of 8 microg/ml against the multiresistant Staphylococcus aureus (MRSA).
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Antibacterianos/síntesis química , Antibacterianos/farmacología , Farmacorresistencia Bacteriana Múltiple/efectos de los fármacos , Furanos/síntesis química , Staphylococcus aureus/efectos de los fármacos , Compuestos de Bromina/síntesis química , Compuestos de Bromina/farmacología , Compuestos de Cloro/síntesis química , Compuestos de Cloro/farmacología , Técnicas Químicas Combinatorias/métodos , Cristalografía por Rayos X/métodos , Escherichia coli/efectos de los fármacos , Escherichia coli/crecimiento & desarrollo , Furanos/farmacología , Espectroscopía de Resonancia Magnética/métodos , Pruebas de Sensibilidad Microbiana/métodos , Estructura Molecular , Pseudomonas aeruginosa/efectos de los fármacos , Pseudomonas aeruginosa/crecimiento & desarrollo , Staphylococcus aureus/crecimiento & desarrollo , Relación Estructura-Actividad , Tecnología Farmacéutica/métodosRESUMEN
The goal of this paper is to stress the significance of ethics for engineering education and to illustrate how it can be brought into the mainstream of higher education in a natural way that is integrated with the teaching objectives of enriching the core meaning of engineering. Everyone will agree that the practicing engineer should be virtuous, should be a good colleague, and should use professional understanding for the common good. But these injunctions to virtue do not reach closely enough the ethic of the engineer as engineer, as someone acting in a uniquely engineering situation, and it is to such conditions that I wish to speak through a set of specific examples from recent history. I shall briefly refer to four controversies between engineers. Then, in some detail I shall narrate three historical cases that directly involve the actions of one engineer, and finally I would like to address some common contemporary issues. The first section, Engineering Ethics and the History of Innovation, includes four cases involving professional controversy. Each controversy sets two people against each other in disputes over who invented the telegraph, the radio, the automobile, and the airplane. In each dispute, it is possible to identify ethical and unethical behavior or ambiguous ethical behavior that serves as a basis for educational discussion. The first two historical cases described in "Crises and the Engineer" involve the primary closure dam systems in The Netherlands, each one the result of the actions of one engineer. The third tells of an American engineer who took his political boss, a big city mayor, to court over the illegal use of a watershed. The challenges these engineers faced required, in the deepest sense, a commitment to ethical behavior that is unique to engineering and instructive to our students. Finally, the cases in "Professors and Comparative Critical Analysis" illuminate the behavior of engineers in the design of structures and also how professors can make public criticisms of designs that seem wasteful.
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Ingeniería/educación , Ética Profesional/educación , Ingeniería/ética , Ingeniería/historia , Ética Profesional/historia , Historia del Siglo XIX , Historia del Siglo XX , Estados UnidosRESUMEN
As part of a study into antimycobacterial compounds a set of phenolic N1-benzylidene-pyridinecarboxamidrazones was prepared and evaluated. This report describes the unexpected discovery of a potent compound with a pronounced selectivity for Gram-positive bacteria over Gram-negative micro-organisms. In addition, this compound is active against various drug-resistant Gram-positive bacteria.
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Antibacterianos/farmacología , Bacterias Grampositivas/efectos de los fármacos , Piridinas/farmacología , Antibacterianos/síntesis química , Antibacterianos/química , Farmacorresistencia Bacteriana , Humanos , Leucocitos/efectos de los fármacos , Pruebas de Sensibilidad Microbiana , Estructura Molecular , Piridinas/síntesis química , Piridinas/química , Relación Estructura-ActividadRESUMEN
Derivatives of salicylic acid have been synthesized as potential lipoxygenase inhibitors. Agents containing a phenolic dihydroxy moiety showed potent (IC(50)10(-6)-10(-7) M) inhibition of the growth of murine colonic tumour cells in vitro, and were effective inhibitors of 5-, 12- and 15-lipoxygenase in intact cells. The catechols were also potent inhibitors of rabbit reticulocyte 15-lipoxygenase (IC(50) approximately 1 microM).
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Antineoplásicos/síntesis química , Antineoplásicos/farmacología , Catecoles/síntesis química , Catecoles/farmacología , Inhibidores de la Lipooxigenasa/síntesis química , Inhibidores de la Lipooxigenasa/farmacología , Animales , Araquidonato 12-Lipooxigenasa/metabolismo , Araquidonato 15-Lipooxigenasa/metabolismo , Ácido Araquidónico/metabolismo , División Celular/efectos de los fármacos , Línea Celular Tumoral , Indicadores y Reactivos , Ratones , Conformación Molecular , Conejos , Relación Estructura-ActividadRESUMEN
Oxidation of low-density lipoprotein (LDL) has been recognized as playing an important role in the development and progression of atherosclerotic heart disease. Human LDL was isolated and challenged with a range of oxidants either in the presence or absence of AGE or its diethyl ether extract. Oxidative modification of the LDL fraction using CuSO(4), 5-lipoxygenase and xanthine/xanthine oxidase was monitored by both the appearance of thiobarbituric-acid substances (TBA-RS) and an increase in electrophoretic mobility. This study indicates that AGE is an effective antioxidant as it scavenged superoxide ions and reduced lipid peroxide formation in cell free assays. Superoxide production was completely inhibited in the presence of a 10% (v/v) aqueous preparation of AGE and reduced by 34% in the presence of a 10% (v/v) diethyl ether extract of AGE. The presence of 10% (v/v) diethyl ether extract of AGE significantly reduced Cu(2+) and 15-lipoxygenase-mediated lipid peroxidation of isolated LDL by 81% and 37%, respectively. In addition, it was found that AGE also had the capacity to chelate copper ions. In contrast, the diethyl ether extract of AGE displayed no copper binding capacity, but demonstrated distinct antioxidant properties. These results support the view that AGE inhibits the in vitro oxidation of isolated LDL by scavenging superoxide and inhibiting the formation of lipid peroxides. AGE was also shown to reduce LDL oxidation by the chelation of Cu(2+). Thus, AGE may have a role to play in preventing the development and progression of atherosclerotic disease.
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Antioxidantes/farmacología , Ajo/química , Peroxidación de Lípido/efectos de los fármacos , Lipoproteínas LDL/metabolismo , Extractos Vegetales/farmacología , Superóxidos/antagonistas & inhibidores , Cobre/metabolismo , Cobre/farmacología , Grupo Citocromo c/metabolismo , Electroforesis en Gel de Agar , Humanos , Immunoblotting , Técnicas In Vitro , Lipooxigenasa/metabolismo , Lipooxigenasa/farmacología , Oxidación-Reducción , Superóxidos/metabolismo , Sustancias Reactivas al Ácido Tiobarbitúrico/análisis , Ácido Úrico/metabolismo , Xantina/farmacología , Xantina Oxidasa/metabolismoRESUMEN
One hundred sixty-eight multiply substituted 1,4-benzodiazepines have been prepared by a five-step solid-phase combinatorial approach using syn-phase crowns as a solid support and a hydroxymethyl-phenoxy-acetamido linkage (Wang linker). The substituents of the 1,4-benzodiazepine scaffold have been varied in the -3, -5, -7, and 8-positions and the combinatorial library was evaluated in a chole cys to kinin (CCK) radioligand binding assay. 3-Alkylated 1,4-benzodiazepines with selectivity towards the CCK-B (CCK2) receptor have been optimized on the lipophilic side chain, the ketone moiety, and the stereochemistry at the 3-position. Various novel 3-alkylated compounds were synthesized and [S]3-propyl-5-phenyl-1,4-benzodiazepin-2-one, [S]NV-A, has shown a CCK-B selective binding at about 180 nM. Fifty-eight compounds of this combinatorial library were purified by preparative TLC and 25 compounds were isolated and fully characterized by TLC, IR, APCI-MS, and 1H/13C-NMR spectroscopy.
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Benzodiazepinas/síntesis química , Benzodiazepinas/metabolismo , Técnicas Químicas Combinatorias/métodos , Receptores de Colecistoquinina/metabolismo , Animales , Benzodiazepinas/química , Encéfalo/metabolismo , Cobayas , Masculino , Receptor de Colecistoquinina BRESUMEN
A novel synthetic approach towards N1-alkylated 3-propyl-1,4-benzodiazepines was developed in five synthetic steps from 2-amino-4-chlorobenzophenone, in which the N-oxide 4 served as a key intermediate. The structure-activity relationship optimization of this 3-propyl-1,4-benzodiazepine template was carried out on the N1-position by selective alkylation reactions and resulted in a ligand with an improved affinity on the cholecystokinin (CCK2) receptor. The N-allyl-3-propyl-benzodiazepine 6d displayed an affinity towards the CCK2 (CCK-B) receptor of 170 nM in a radiolabelled receptor-binding assay. The anxiolytic activity of this allyl-3-propyl-1,4-benzodiazepine 6d was subsequently determined in in-vivo psychotropic assays. This novel ligand had ED50 values of 4.7 and 5.2 mg kg(-1) in the black and white box test and the x-maze, respectively, and no significant sedation/muscle relaxation was observed.