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1.
J Environ Manage ; 354: 120428, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38387359

RESUMO

Utilising cardboard waste for the partial substitution of cement within concrete has the potential to yield significant sustainability benefits. Cardboard waste is abundantly available, and a significant proportion of this material is disposed of in landfill. However, conversion of waste cardboard into kraft fibres (KFs) for concrete implementation can be utilised in the building and construction industry. Therefore, identification of sustainability variables associated with cardboard waste in concrete is vital. In this study, two KF composites satisfied the criteria for low stress grade concrete and were subsequently evaluated. SFKF5 mix design contained 5% KFs and SFKF105 contained 10% KFs with 5% metakaolin (MK). Both composites had silica fume (SF) as a fibre modification technique for durability purposes. A life cycle assessment (LCA) determined the environmental effect of waste cardboard integration. A Monte-Carlo simulation was utilised as the sensitivity analysis to investigate transportation and energy manufacturing greenhouse gas (GHG) emission variables. LCA results of SFKF105 had a savings of 11%, 8%, 4% and 1% for terrestrial acidification potential, global warming potential (GWP), terrestrial ecotoxicity potential (TEP) and human toxicity potential, respectively. SFKF5 revealed savings of 3%, 2% and 4% for GWP, TEP and marine eutrophication potential, respectively. The additional travel requirements of KFs and MK to the cement batching plant for composite production did not surpass the embodied energy and travel emissions of the control. However, this was negated due to the additional energy requirements to manufacture KFs. The control, SFKF5, and SFKF105 had an average total of 572, 1023 and 997 kgCO2-eq/m3, respectively.


Assuntos
Indústria da Construção , Gases de Efeito Estufa , Humanos , Animais , Aquecimento Global , Gases , Estágios do Ciclo de Vida
2.
Materials (Basel) ; 15(24)2022 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-36556769

RESUMO

The building and construction industry consumes a significant amount of virgin resources and minimizing the demand with alternative waste materials can provide a contemporary solution. In this study, thermal components of kraft fibres (KFs) derived from waste cardboard are investigated. The mechanical properties containing KFs within concrete composites are evaluated. Metakaolin (MK) and KFs were integrated into concrete samples as a partial substitute for cement. Silica Fume (SF) was applied to the KF (SFKFs) with a view to enhancing the fibre durability. The results indicated that there was a reduction in compressive strength of 44 and 56% when 10% raw and modified KFs were integrated, respectively. Raw, fibre and matrix-modified samples demonstrated a 35, 4 and 24% flexural strength reduction, respectively; however, the tensile strength improved by 8% when the matrix was modified using MK and SFKF. The morphology of the fibres was illustrated using a scanning electron microscope (SEM), with an energy dispersion X-ray spectroscopy (EDS) provision and Fourier transform infrared spectroscopy (FT-IR) employed to gain insights into their chemical nature. The thermal, calorimetric and combustion attributes of the fibres were measured using thermogravimetric analysis (TGA), differential scanning calorimetry (DSC) and pyrolysis combustion flow calorimetry (PCFC). SFKFs showed a lower heat release capacity (HRC), demonstrating a lower combustion propensity compared to raw KFs. Furthermore, the 45% decreased peak heat release rate (pHRR) of SFKFs highlighted the overall reduction in the fire hazards associated with these materials. TGA results also confirmed a lower mass weight loss of SFKFs at elevated temperatures, thus corroborating the results from the PCFC runs.

3.
J Med Chem ; 51(24): 8124-34, 2008 Dec 25.
Artigo em Inglês | MEDLINE | ID: mdl-19053774

RESUMO

Vasopressin (AVP) is a hormone that stimulates an increase in water permeability through activation of V2 receptors in the kidney. The analogue of AVP, desmopressin, has proven an effective drug for diseases where a reduction of urine output is desired. However, its peptidic nature limits its bioavailability. We report herein the discovery of potent, nonpeptidic, benzylurea derived agonists of the vasopressin V2 receptor. We describe substitutions on the benzyl group to give improvements in potency and subsequent modifications to the urea end group to provide improvements in solubility and increased oral efficacy in a rat model of diuresis. The lead compound 20e (VA106483) is reported for the first time and has been selected for clinical development.


Assuntos
Química Farmacêutica/métodos , Receptores de Vasopressinas/agonistas , Ureia/química , Administração Oral , Animais , Células CACO-2 , Diurese , Relação Dose-Resposta a Droga , Desenho de Fármacos , Avaliação Pré-Clínica de Medicamentos , Humanos , Modelos Químicos , Ratos , Ratos Brattleboro , Solubilidade
4.
Dalton Trans ; (4): 506-13, 2008 Jan 28.
Artigo em Inglês | MEDLINE | ID: mdl-18185867

RESUMO

The co-ordination of a series of terpyridine-N-oxide ligands to the Cu(ii) ion is reported. Addition of two equivalents of ligand results in the formation of the expected 2 : 1 six co-ordinate product, while the addition of one equivalent of ligand allows the isolation of 1 : 1 species if the ligand has a meridonal binding mode. The five complexes isolated were characterised in the solid state by X-ray crystallography while they are studied in solution using EPR, UV-vis spectroscopy and IR spectroscopy.


Assuntos
Óxidos/química , Percloratos/síntese química , Piridinas/química , Cor , Cobre/química , Cristalografia por Raios X , Espectroscopia de Ressonância de Spin Eletrônica , Modelos Moleculares , Estrutura Molecular , Percloratos/química , Espectrofotometria
5.
Dalton Trans ; (16): 1630-8, 2007 Apr 28.
Artigo em Inglês | MEDLINE | ID: mdl-17426865

RESUMO

Europium complexes of a series of terpyridine-N-oxide ligands have been prepared and structurally characterised by crystallographic studies. While the addition of three equivalents of terpyridine-1-oxide or terpyridine-1,1'-bisoxide results in complexes with nine co-ordinate tricapped trigonal prismatic or monocapped square antiprismatic geometries, respectively, three equivalents of the terpyridine-1,1',1'-trisoxide yields an unexpected 8 co-ordinate geometry. Luminescence studies of the three complexes in acetonitrile show a typical europium emission spectra, dominated by the (5)D(0)-(7)F(2) transition. While no simple trend in the relative quantum yields could be ascertained, the terpyridine-1-oxide complex was observed to have the most intense luminescence for this set of complexes.


Assuntos
Európio/química , Compostos Organometálicos/química , Óxidos/química , Óxidos/síntese química , Piridinas/química , Físico-Química/métodos , Cristalografia por Raios X/métodos , Ligantes , Luminescência , Espectroscopia de Ressonância Magnética , Modelos Químicos , Conformação Molecular , Estrutura Molecular , Compostos Organometálicos/síntese química , Fatores de Tempo
6.
J Pharmacol Exp Ther ; 320(3): 1113-8, 2007 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-17179469

RESUMO

Degarelix (FE 200486) is a member of a new class of water-soluble (>50 mg/ml) gonadotropin-releasing hormone (GnRH) antagonists in clinical development for prostate cancer. Upon subcutaneous administration, degarelix forms a gel that results in a sustained release of the compound into the circulation, immediately blocking GnRH receptors in the pituitary and inducing a fast and sustained suppression of gonadotrophin secretion in rats and primates. One of the few animal models of prostate adenocarcinoma is the Dunning R-3327H rat carcinoma transplanted into Copenhagen rats. The growth of the Dunning tumor can be inhibited by various treatments reported to be effective in the clinic, such as GnRH superagonists, antiandrogens, 5-alphareductase inhibitors, tyrosine kinase inhibitors, and surgical castration. We report in this study that degarelix produces a fast and sustained suppression of the pituitary gonadal axis in rats and a similar inhibition of tumor growth compared with surgical castration in the Dunning R-3327H rat carcinoma model. First, degarelix as been compared with d-Trp(6)-luteinizing hormone-releasing hormone and surgical castration on a short-term study (2 months); and second, degarelix has been compared with leuprolide and surgical castration on a long-term study (12 months). In both studies, degarelix demonstrated a sustained inhibition of tumor growth at least comparable with surgical castration. These data provide a convincing profile of degarelix as a potential candidate for the clinical management of sex steroid-dependent pathologies, such as prostate cancer, where long-term reversible chemical castration is required.


Assuntos
Antineoplásicos/uso terapêutico , Hormônio Liberador de Gonadotropina/antagonistas & inibidores , Oligopeptídeos/uso terapêutico , Neoplasias da Próstata/tratamento farmacológico , Testosterona/sangue , Animais , Antineoplásicos/administração & dosagem , Antineoplásicos/farmacologia , Castração , Leuprolida/administração & dosagem , Leuprolida/farmacologia , Leuprolida/uso terapêutico , Masculino , Transplante de Neoplasias , Oligopeptídeos/administração & dosagem , Oligopeptídeos/farmacologia , Tamanho do Órgão/efeitos dos fármacos , Neoplasias da Próstata/sangue , Neoplasias da Próstata/metabolismo , Neoplasias da Próstata/patologia , Ratos , Ratos Endogâmicos , Testículo/efeitos dos fármacos , Testículo/patologia
7.
J Am Chem Soc ; 128(11): 3818-30, 2006 Mar 22.
Artigo em Inglês | MEDLINE | ID: mdl-16536558

RESUMO

Iron(II) templates based on a [(eta(5)-Cp(R))Fe]+ core have been employed for the successful synthesis of 1,4,7-triphosphacyclononane derivatives (9-aneP3R'3) from a range of appropriately functionalized coordinated diphosphines and monophosphines. 1,2-Diphosphinoethane (1,2-dpe) or (2-phosphinoethyl)phenylphosphine (Phdpe) undergo a base-catalyzed Michael-type addition to trivinylphosphine, divinyl(benzyl)phosphine, or divinyl(phenyl)phosphine in [(eta(5)-Cp(R))Fe(diphosphine)(monophosphine)]+ complexes (2a-j) to give [(eta(5)-Cp(R))Fe(9aneP3R'3)]+ derivatives (4a-j) containing coordinated triphosphacyclononanes bearing one (with Phdpe) or two (with 1,2-dpe) secondary phosphine donors. The rates of macrocyclization show a dependence on the nature of the substituent(s) R on the cyclopentadienyl ligand with increased rates being observed along the series R = H5 < (Me3Si)H4 < 1,3-(Me3Si)2H3 approximately = Me5. For coupling reactions with trivinylphosphine, a pendant vinyl function remains in the macrocyclic product (4a-g) which is readily hydrogenated to the corresponding ethyl derivatives (5a-g). Further functionalization of coordinated secondary phosphines in the initially formed macrocycles (5a-g) is achieved by proton abstraction followed by addition of the appropriate alkyl halide electrophile and gives rise to tritertiary-triphospha-cyclononanes (7a-g, 7l, 7m). All new complexes have been fully characterized by spectroscopic and analytical methods in addition to the structural determination by single-crystal X-ray techniques of [{eta(5)-(Me3Si)2C5H3)Fe(9-aneP3H2C2H3)]PF6, 4c, and [(eta(5)-Me3SiC5H4)Fe(9-aneP3Et3)]BF4, 7b. 1,4,7-Triethyl-1,4,7-triphosphacyclononane is released from its metal template (7a, 7b) by treatment with either H2O2 or Br2/H2O to give the trioxide 9-aneP3(O)3Et3 (8). Attempts to recover the trivalent phosphorus species, 1,4,7-triethyl-1,4,7-triphosphacyclononane, from the trioxide by reduction proved unsuccessful.

8.
Dalton Trans ; (47): 5574-82, 2006 Dec 21.
Artigo em Inglês | MEDLINE | ID: mdl-17225894

RESUMO

The sequential treatment of Lewis acids with N,N'-bidentate ligands and thereafter with ButLi has afforded a series of hydride-encapsulating alkali metal polyhedra. While the use of Me3Al in conjunction with Ph(2-C5H4N)NH gives Ph(2-C5H4N)NAlMe2 and this reacts with MeLi in thf to yield the simple 'ate complex Ph(2-C5H4N)NAlMe3Li.thf, the employment of an organolithium substrate capable of beta-hydride elimination redirects the reaction significantly. Whereas the use of ButLi has previously yielded a main group interstitial hydride in which H- exhibits micro6-coordination, it is shown here that variability in the coordination sphere of the encapsulated hydride may be induced by manipulation of the organic ligand. Reaction of (c-C6H11)(2-C5H4N)NH with Me3Al/ButLi yields [{(c-C6H11)(2-C5H4N)N}6HLi8]+[(But2AlMe2)2Li]-, which is best viewed as incorporating only linear di-coordination of the hydride ion. The guanidine 1,3,4,6,7,8-hexahydro-2H-pyrimido[1,2-a]pyrimidine (hppH) in conjunction with Me2Zn/ButLi yields the micro8-hydride [(hpp)6HLi8]+[But3Zn]-.0.5PhMe. Formation of the micro8-hydride [(hpp)6HLi8]+[ButBEt3]- is revealed by employment of the system Et3B/ButLi. A new and potentially versatile route to interstitial hydrides of this class is revealed by synthesis of the mixed borohydride-lithium hydride species [(hpp)6HLi8]+[Et3BH]- and [(hpp)6HLi8]+[(Et3B)2H]- through the direct combination of hppLi with Et3BHLi.

9.
Dalton Trans ; (21): 3568-74, 2004 Nov 07.
Artigo em Inglês | MEDLINE | ID: mdl-15510278

RESUMO

Dimethylzinc reacts with an excess of N-2-pyridylaniline 6 to give the homoleptic species, Zn[PhN(2-C(5)H(4)N)](2) 8. Single crystal X-ray diffraction reveals a solid-state dimer based on an 8-membered (NCNZn)(2) core motif. Zn[CyN(2-C(5)H(4)N)]Me (Cy =c-C(6)H(11)) 10, prepared by the combination of ZnMe(2) with the corresponding cyclohexyl-substituted pyridylamine, is also dimeric in the solid state but reveals a central (ZnN)(2) metallacycle. Employment of (p-Tol)NH(2-C(5)H(4)N)(p-Tol = 4-MeC(6)H(4)) 11 yielded the tris(zinc) adduct Zn(3)[(p-Tol)N(2-C(5)H(4)N)](4)Me(2) 12, which incorporates a central chiral molecule of 'Zn[(p-Tol)N(2-C(5)H(4)N)](2)' 12a, that bridges two 'Zn[(p-Tol)N(2-C(5)H(4)N)]Me' 12b units. A similar trimetallic structure is noted when the pyridylaniline substrate 11 is replaced with the bicyclic guanidine 1,3,4,6,7,8-hexahydro-2H-pyrimido[1,2-a]pyrimidine (hppH), affording Zn(3)(hpp)(4)Me(2) 13. Spectroscopic studies point to retention of the solid-state structure of in hydrocarbon solution. Reaction of 13 with dimesityl borinic acid, Mes(2)BOH (Mes = mesityl), affords Zn(3)(hpp)(4)(OBMes(2))(2) 14 in which the trimetallic core is retained. This reactivity is in contrast to the closely related reaction of dimeric Zn[Me(2)NC[N(i)Pr](2)]Me 15 with Mes(2)BOH, which yielded Zn[Me(2)NC[N(i)Pr](2)][OBMes(2)].Me(2)NC[N(i)Pr][NH(i)Pr] 16 as a result of protonation at the guanidine ligand in addition to the Zn-Me bond.

10.
Bioorg Med Chem Lett ; 14(17): 4585-9, 2004 Sep 06.
Artigo em Inglês | MEDLINE | ID: mdl-15357997

RESUMO

A library of compounds targeted to the vasopressin/oxytocin family of receptors was screened for activity at a cloned human oxytocin receptor using a reporter gene assay. Potency and selectivity were optimised to afford compound 39, EC50 = 33 nM. This series of compounds represents the first disclosed, non-peptide, low molecular weight agonists of the hormone oxytocin (OT).


Assuntos
Benzazepinas/química , Ocitocina/agonistas , Pirrolidinas/química , Antagonistas de Receptores de Angiotensina , Animais , Antagonistas dos Receptores de Hormônios Antidiuréticos , Benzazepinas/metabolismo , Células CHO , Linhagem Celular , Cricetinae , Relação Dose-Resposta a Droga , Humanos , Ocitocina/antagonistas & inibidores , Ocitocina/metabolismo , Pirrolidinas/metabolismo , Receptores de Angiotensina/agonistas , Receptores de Angiotensina/metabolismo , Receptores de Ocitocina/agonistas , Receptores de Ocitocina/antagonistas & inibidores , Receptores de Ocitocina/metabolismo , Receptores de Vasopressinas/agonistas , Receptores de Vasopressinas/metabolismo
13.
Chem Commun (Camb) ; (16): 2052-3, 2003 Aug 21.
Artigo em Inglês | MEDLINE | ID: mdl-12934907

RESUMO

The reaction of MeAlCl2 with MesPHLi (1:4 equivalents) in thf/toluene gives the cage complex [[MeAl(mu-PMes)(PMes)]2Li4]2 x 7thf (1), containing an [[MeAl(mu-PMes)(PMes))2]4- tetraanion which is valence-isoelectronic with extensively studied Group 15 anions of the type [E(mu-NR)(NR)]2(2-).

14.
Chem Commun (Camb) ; (11): 1288-9, 2003 Jun 07.
Artigo em Inglês | MEDLINE | ID: mdl-12809234

RESUMO

The reaction of CyPHNa with Sn(NMe2)2 in the presence of PMDETA (= (Me2NCH2CH2)2NMe) gives the title compound [(Sn(mu-PCy))3(Na x PMDETA)2] (1), containing an electron-deficient [(Sn(mu-PCy))]3(2-) dianion with a novel two-electron, three centre (2e-3c) bonding arrangement.

15.
Diabetes ; 51(5): 1461-9, 2002 May.
Artigo em Inglês | MEDLINE | ID: mdl-11978643

RESUMO

Acute suppression of dipeptidyl peptidase IV (DPP-IV) activity improves glucose tolerance in the Zucker fatty rat, a rodent model of impaired glucose tolerance, through stabilization of glucagon-like peptide (GLP)-1. This study describes the effects of a new and potent DPP-IV inhibitor, FE 999011, which is able to suppress plasma DPP-IV activity for 12 h after a single oral administration. In the Zucker fatty rat, FE 999011 dose-dependently attenuated glucose excursion during an oral glucose tolerance test and increased GLP-1 (7-36) release in response to intraduodenal glucose. Chronic treatment with FE 999011 (10 mg/kg, twice a day for 7 days) improved glucose tolerance, as suggested by a decrease in the insulin-to-glucose ratio. In the Zucker diabetic fatty (ZDF) rat, a rodent model of type 2 diabetes, chronic treatment with FE 999011 (10 mg/kg per os, once or twice a day) postponed the development of diabetes, with the twice-a-day treatment delaying the onset of hyperglycemia by 21 days. In addition, treatment with FE 999011 stabilized food and water intake to prediabetic levels and reduced hypertriglyceridemia while preventing the rise in circulating free fatty acids. At the end of treatment, basal plasma GLP-1 levels were increased, and pancreatic gene expression for GLP-1 receptor was significantly upregulated. This study demonstrates that DPP-IV inhibitors such as FE 999011 could be of clinical value to delay the progression from impaired glucose tolerance to type 2 diabetes.


Assuntos
Diabetes Mellitus Tipo 2/tratamento farmacológico , Diabetes Mellitus/tratamento farmacológico , Dipeptidil Peptidase 4/sangue , Nitrilas/farmacologia , Obesidade , Inibidores de Proteases/farmacologia , Pirrolidinas/farmacologia , Animais , Glicemia , Diabetes Mellitus/sangue , Diabetes Mellitus/enzimologia , Diabetes Mellitus Tipo 2/sangue , Ingestão de Líquidos/efeitos dos fármacos , Ingestão de Alimentos/efeitos dos fármacos , Ácidos Graxos não Esterificados/sangue , Expressão Gênica/fisiologia , Glucagon/sangue , Peptídeo 1 Semelhante ao Glucagon , Receptor do Peptídeo Semelhante ao Glucagon 1 , Teste de Tolerância a Glucose , Humanos , Insulina/sangue , Masculino , Nitrilas/química , Pâncreas/fisiologia , Fragmentos de Peptídeos/sangue , Inibidores de Proteases/química , Precursores de Proteínas/sangue , Pirrolidinas/química , Ratos , Ratos Zucker , Receptores de Glucagon/genética , Triglicerídeos/sangue , Aumento de Peso/efeitos dos fármacos
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