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1.
Artigo em Inglês | MEDLINE | ID: mdl-35450934

RESUMO

BACKGROUND: Northern England has been experiencing a persistent rise in the number of primary liver cancers, largely driven by an increasing incidence of hepatocellular carcinoma (HCC) secondary to alcohol-related liver disease and non-alcoholic fatty liver disease. Here we review the effect of the COVID-19 pandemic on primary liver cancer services and patients in our region. OBJECTIVE: To assess the impact of the COVID-19 pandemic on patients with newly diagnosed liver cancer in our region. DESIGN: We prospectively audited our service for the first year of the pandemic (March 2020-February 2021), comparing mode of presentation, disease stage, treatments and outcomes to a retrospective observational consecutive cohort immediately prepandemic (March 2019-February 2020). RESULTS: We observed a marked decrease in HCC referrals compared with previous years, falling from 190 confirmed new cases to 120 (37%). Symptomatic became the the most common mode of presentation, with fewer tumours detected by surveillance or incidentally (% surveillance/incidental/symptomatic; 34/42/24 prepandemic vs 27/33/40 in the pandemic, p=0.013). HCC tumour size was larger in the pandemic year (60±4.6 mm vs 48±2.6 mm, p=0.017), with a higher incidence of spontaneous tumour haemorrhage. The number of new cases of intrahepatic cholangiocarcinoma (ICC) fell only slightly, with symptomatic presentation typical. Patients received treatment appropriate for their cancer stage, with waiting times shorter for patients with HCC and unchanged for patients with ICC. Survival was associated with stage both before and during the pandemic. 9% acquired COVID-19 infection. CONCLUSION: The pandemic-associated reduction in referred patients in our region was attributed to the disruption of routine healthcare. For those referred, treatments and survival were appropriate for their stage at presentation. Non-referred or missing patients are expected to present with more advanced disease, with poorer outcomes. While protective measures are necessary during the pandemic, we recommend routine healthcare services continue, with patients encouraged to engage.


Assuntos
COVID-19 , Carcinoma Hepatocelular , Neoplasias Hepáticas , COVID-19/epidemiologia , Carcinoma Hepatocelular/epidemiologia , Humanos , Neoplasias Hepáticas/epidemiologia , Pandemias , Estudos Retrospectivos
2.
Chem Commun (Camb) ; 56(24): 3559-3562, 2020 Mar 25.
Artigo em Inglês | MEDLINE | ID: mdl-32104796

RESUMO

7-Borylindoles undergo a one-pot oxidative-hydrolysis of the arylboronate and oxidative cleavage of the indole C2-C3 double bond to afford o-amidophenol derivatives. Subsequent cyclisation delivers benzoxazoles bearing an acyl group at C4, a substitution pattern common to fungal-derived benzoxazole alkaloids. Using 7-borylindoles as substrates to access functionalised o-amidophenols circumvents the difficult preparation of these compounds from arenes, streamlining access to substituted 4-acylbenzoxazoles in the process.

3.
Scand J Gastroenterol ; 49(4): 473-80, 2014 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-24472065

RESUMO

OBJECTIVE: To determine the yield of endoscopic ultrasound (EUS) in the investigation of patients with normal liver function tests (LFTs) and unexplained dilatation of common bile duct (CBD) and/or pancreatic duct (PD), following CT and/or magnetic resonance cholangiopancreatography. MATERIALS AND METHODS: Consecutive patients undergoing linear EUS between January 2007 and August 2011 for the indication of dilated CBD and/or PD, normal LFT, and nondiagnostic cross-sectional imaging formed the study group. The study was performed as a retrospective analysis of prospectively collected data. RESULTS: During the study period, 83 patients (CBD and PD dilatation n = 38, PD dilatation n = 5, CBD dilatation n = 40) met the inclusion criteria and underwent EUS. Five (13.1%) of the CBD and PD groups had a new finding, which in one (2.6%) case was causal. In this group, men were significantly more likely to have a new finding (p = 0.012). Eight (20%) of the CBD group had a new finding, which in seven (17.5%) cases was causal. In the CBD group, cholecystectomy was significantly (p = 0.005) more common in those without a finding. Three (60%) of the PD group had a finding on EUS, all of which were causal, including a case of pancreatic malignancy. CONCLUSION: There is a significant yield from EUS in individuals with isolated PD dilatation and isolated CBD dilatation. Previous cholecystectomy is significantly associated with a negative EUS in the group with isolated CBD dilatation. The yield in those with CBD and PD dilatation was low and a finding was more likely in males.


Assuntos
Ducto Colédoco/diagnóstico por imagem , Endossonografia/métodos , Ductos Pancreáticos/diagnóstico por imagem , Adulto , Idoso , Idoso de 80 Anos ou mais , Colangiopancreatografia por Ressonância Magnética , Ducto Colédoco/patologia , Dilatação Patológica , Feminino , Humanos , Testes de Função Hepática , Masculino , Pessoa de Meia-Idade , Ductos Pancreáticos/patologia , Estudos Retrospectivos , Tomografia Computadorizada por Raios X
4.
J Gastrointestin Liver Dis ; 21(1): 105-7, 2012 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-22457868

RESUMO

Pancreatic tuberculosis is a rare disease. It can be easily confused with malignancy or pancreatitis on imaging. This could result in unnecessary surgery. As this is a treatable disease it is imperative to diagnose this condition pre-operatively. We report three cases of pancreatic tuberculosis that were diagnosed by endoscopic ultrasound. In conclusion, endoscopic ultrasound is the diagnostic modality of choice for pancreatic tuberculosis facilitating high resolution imaging, as well as sampling of tissue for staining, cytology, culture and polymerase chain reaction assay.


Assuntos
Endossonografia , Pâncreas/diagnóstico por imagem , Pancreatopatias/diagnóstico por imagem , Tuberculose/diagnóstico por imagem , Adulto , Humanos , Masculino
5.
Chemistry ; 17(37): 10259-71, 2011 Sep 05.
Artigo em Inglês | MEDLINE | ID: mdl-21837711

RESUMO

Tetrasodium p-sulfonatocalix[4]arene exists as a hydrate with approximately 14 water molecules and has three polymorphic modifications, all of which contain a water molecule in the molecular cavity that is engaged in OH···π interactions. Single-crystal neutron structures are reported for two of these three forms and reveal a "compressed" water molecule with short OH bonds. Partial atomic charges and hardness analysis (PACHA) calculations based on the neutron coordinates give an OH···π interaction energy of 6.9-7.5 kJ mol(-1). The PACHA analysis also reveals the dominance of the charge-assisted hydrogen bonds from the Na(+)-coordinated water molecules. The instability of the crystal towards dehydration can be traced to an uncoordinated lattice water site. The remarkable calixarene-Na(+)-hydrate motif is conserved almost unchanged across all three polymorphs. A single-crystal neutron structure is also reported for pentasodium p-sulfonatocalix[4]arene·12H(2)O, which exhibits an intracavity water molecule that is engaged in both OH···π and OH···O hydrogen bonding. The shorter covalent bond to the hydrogen atom that forms the interaction with the aromatic ring is again apparent.

6.
Inorg Chem ; 50(17): 8524-31, 2011 Sep 05.
Artigo em Inglês | MEDLINE | ID: mdl-21834508

RESUMO

Rhenium(I) compounds [Re(CO)(3)(Hdmpz)(2)(ampy)]BAr'(4) and [Re(CO)(3)(N-MeIm)(2)(ampy)]BAr'(4) (Hdmpz = 3,5-dimethylpyrazole, N-MeIm = N-methylimidazole, ampy = 2-aminopyridine or 3-aminopyridine) have been prepared stepwise as the sole reaction products in good yields. The cationic complexes feature two different types of hydrogen bond donor ligands, and their anion binding behavior has been studied both in solution and in the solid state. Compounds with 2-ampy ligands are labile in the presence of nearly all of the anions tested. The X-ray structure of the complex [Re(CO)(3)(Hdmpz)(2)(ampy)](+) (2) shows that the 2-ampy ligand is metal-coordinated through the amino group, a fact that can be responsible for its labile character. The 3-ampy derivatives (coordinated through the pyridinic nitrogen atom) are stable toward the addition of several anions and are more selective anion hosts than their tris(pyrazole) or tris(imidazole) counterparts. This selectivity is higher for compound [Re(CO)(3)(N-MeIm)(2)(MeNA)]BAr'(4) (5·BAr'(4), MeNA = N-methylnicotinamide) that features an amido moiety, which is a better hydrogen bond donor than the amino group. Some of the receptor-anion adducts have been characterized in the solid state by X-ray diffraction, showing that both types of hydrogen bond donor ligands of the cationic receptor participate in the interaction with the anion hosts. DFT calculations suggest that coordination of the ampy ligands is more favorable through the amino group only for the cationic complex 2, as a consequence of the existence of a strong intramolecular hydrogen bond. In all other cases, the pyridinic coordination is clearly favored.


Assuntos
Monóxido de Carbono/química , Compostos Organometálicos/química , Rênio/química , Ânions/química , Cristalografia por Raios X , Ligação de Hidrogênio , Ligantes , Modelos Moleculares , Estrutura Molecular , Compostos Organometálicos/síntese química , Teoria Quântica , Estereoisomerismo
7.
Br J Ophthalmol ; 95(3): 365-9, 2011 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-20610474

RESUMO

AIM: Rhegmatogenous retinal detachment (RRD) is a common and sight-threatening condition. The reported incidence of RRD has varied considerably in published literature and few studies have examined the temporal trends in incidence rate over a long time period. Our aim is to examine the time trends of primary RRD in Scotland. METHODS: We obtained linked hospital episode statistics data for all patients admitted with a primary diagnostic code of RRD in Scotland between 1987 and 2006. Using this database as an estimate of RRD incidence, we calculated the annual age- and sex-specific incidence rates of RRD in Scotland. Log-linear Poisson regression analysis was used to explore age, period and cohort trends. RESULTS: The overall age-standardised incidence of RRD in Scotland has steadily increased from 9.36 per 100 000 (95% CI 8.19 to 10.53) in 1987 to 13.61 per 100 000 (95% CI 12.25 to 14.97) in 2006 with an average annual increase of 1.9% (p<0.001) during the 20-year period. Men have been affected more frequently than women in all age groups with a significant temporal trend towards earlier age of onset. The peak incidence of RRD in men and women is in the sixth decade of life. No significant period or recent birth cohort trend effects were found. CONCLUSIONS: The estimated incidence of RRD is within the range reported from previous population-based studies worldwide. The rise in RRD incidence between 1987 and 2006 is attributed in part to the changing demographic in Scotland. There is an increasing sex imbalance in incidence, with men being affected more frequently and at a younger age.


Assuntos
Descolamento Retiniano/epidemiologia , Adolescente , Adulto , Distribuição por Idade , Idoso , Idoso de 80 Anos ou mais , Criança , Pré-Escolar , Feminino , Humanos , Incidência , Lactente , Recém-Nascido , Masculino , Registro Médico Coordenado , Pessoa de Meia-Idade , Descolamento Retiniano/etiologia , Escócia/epidemiologia , Distribuição por Sexo , Adulto Jovem
8.
Dalton Trans ; 40(3): 573-82, 2011 Jan 21.
Artigo em Inglês | MEDLINE | ID: mdl-21116573

RESUMO

A series of tripodal imidazole frameworks (TIFs) are reported based on a tripodal, cavity-containing tris(imidazole) derivative. In the case of [Co(3)Cl(6)(1)(2)]·n(solvent) (TIF-1) which possesses a doubly interpenetrated framework structure, the material exhibits rigid, permanent porosity and selectively absorbs CO(2). The non-interpenetrated [Co(1)(2)(H(2)O)(2)]Cl(2)·4H(2)O (TIF-2) also absorbs gases and vapours fully reversibly exhibiting a reversible phase change in the process and considerable conditioning and hysteresis. The very highly hydrated [Co(1)(2)]Cl(2)·22H(2)O (TIF-3) irreversibly dehydrates to the layered structure [Co(1)(2)]Cl(2)·H(2)O (TIF-4). A nickel analogue [Ni(1)(2)]Cl(2)·22H(2)O (TIF-5) closely related to TIF-3 is also reported along with two isostructural, non-porous materials [MCl(2)(1)] (M = Mn, TIF-6; M = Cd, TIF-7) based on d(5) and d(10) Mn(II) and Cd(II). Some of the materials may be prepared by mechanochemical as well as solution based methods. We liken TIF-1 to a gas cylinder, TIF-2 to a sponge and TIF-3 to a fragile soda can that is crushed on emptying to give TIF-4.

9.
Chemistry ; 16(35): 10818-31, 2010 Sep 17.
Artigo em Inglês | MEDLINE | ID: mdl-20715211

RESUMO

Treatment of a range of bis(thiourea) ligands with inert organometallic transition-metal ions gives a number of novel complexes that exhibit unusual ligand binding modes and significantly enhanced anion binding ability. The ruthenium(II) complex [Ru(η(6)-p-cymene)(κS,S',N-L(3)-H)](+) (2b) possesses juxtaposed four- and seven-membered chelate rings and binds anions as both 1:1 and 2:1 host guest complexes. The pyridyl bis(thiourea) complex [Ru(η(6)-p-cymeme)(κS,S',N(py)-L(4))](2+) (4) binds anions in both 1:1 and 1:2 species, whereas the free ligand is ineffective because of intramolecular NH⋅⋅⋅N hydrogen bonding. Novel palladium(II) complexes with nine- and ten-membered chelate rings are also reported.

10.
Dalton Trans ; 39(25): 5899-907, 2010 Jul 07.
Artigo em Inglês | MEDLINE | ID: mdl-20508889

RESUMO

Monometallic complexes of the tetrakis(pyrazolyl)borate ligand [ML(2){B(pz)(4)}] {M = Rh, Ir; L(2) = eta-cod, eta-nbd, (CO)(2), (CO)(PPh(3))} have two free pyrazolyl rings which can be coordinated to a second ML(2) unit to give the dimeric compounds [L(2)M{mu-B(pz)(4)}ML(2)](+), and to a metal halide to give heterobimetallic species [L(2)M{mu-B(pz)(4)}M'Cl(2)]. (1)H NMR spectroscopy shows that [(eta-cod)Rh{mu-B(pz)(4)}Rh(eta-cod)](+) 1(+), [(eta-nbd)Rh{mu-B(pz)(4)}Rh(eta-nbd)](+) 2(+), [(eta-cod)Ir{mu-B(pz)(4)}Ir(eta-cod)](+) 3(+) and [(CO)(2)Rh{mu-B(pz)(4)}Rh(CO)(2)](+) 4(+) are fluxional at room temperature. Cooling a solution of [(eta-cod)Rh{mu-B(pz)(4)}Rh(eta-cod)](+) 1(+) to -90 degrees C slows the fluxional process, which involves inversion of the two B-(N-N)(2)-M six-membered rings. Attempts to synthesise the asymmetric complexes [(eta-cod)Rh{mu-B(pz)(4)}Rh(eta-nbd)](+) 7(+), [(eta-cod)Rh{mu-B(pz)(4)}Ir(eta-cod)](+) 8(+) and [(eta-cod)Rh{mu-B(pz)(4)}Rh(CO)(2)](+) 9(+) produced a mixture of [L(2)M{mu-B(pz)(4)}ML(2)](+), [L'(2)M'{mu-B(pz)(4)}M'L'(2)](+) and the desired species. The heterobimetallic complexes [L(2)Rh{mu-B(pz)(4)}M'Cl(2)] (M' = Co, L(2) = eta-cod 10; M' = Co, L(2) = eta-nbd 11; M' = Co, L = CO 12; M' = Co, L(2) = (CO)(PPh(3)) 13; M' = Zn, L(2) = eta-cod 14; M' = Zn, L(2) = eta-nbd 15; M' = Pd, L(2) = eta-cod 16) possess square planar Rh(I) linked to square planar Pd(II) or tetrahedral Zn(II) and Co(II) centres. The paramagnetic Co(II) complexes give (1)H NMR spectra with signals shifted over a range of 75 ppm. The UV-Vis spectra of 10-13 show four bands, one MLCT at Rh and three d-d transitions arising from the splitting of the (4)T(1)(P) excited state due to approximate C(2v) symmetry at Co.

11.
Cochrane Database Syst Rev ; (4): CD008189, 2010 Apr 14.
Artigo em Inglês | MEDLINE | ID: mdl-20393968

RESUMO

BACKGROUND: Infertility is a prevalent problem and has significant consequences for individuals, families and the wider community. People's chance of having a healthy, live birth may be impacted upon by factors such as weight, diet, smoking, other substance abuse, environmental pollutants, infections, medical conditions, medications and family medical history. However, there is no current guideline about what preconception advice should be offered to people presenting for infertility treatment. It is important to determine what preconception advice should be given about these types of factors to such people in order to help them to make positive changes and hopefully improve their chances of conception and delivering a healthy, live baby. OBJECTIVES: To assess the effects of preconception advice on the chances of a live birth for people who perceive that they may be infertile and are investigating the possibility of medical treatment to address subfertility. SEARCH STRATEGY: All published and unpublished randomised controlled trials addressing preconception advice to influence lifestyle factors in people who perceived that they may be infertile and investigated the possibility of medical treatment to address subfertility were sought from the Cochrane Menstrual Disorders and Subfertility Review Group Trials Register, Cochrane Central Register of Controlled Trials (CENTRAL), The Cochrane Library, MEDLINE, PubMed, EMBASE, PsycINFO, AMED, Cumulative Index to Nursing and Allied Health Literature (CINAHL), LILACS, trial registers for ongoing and registered trials, citation indexes, ISI Web of Knowledge, Clinical Study Results database, OpenSIGLE database, China National Knowledge Infrastructure (CNKI) Periodical Index and Google (inception to 5 October 2009). SELECTION CRITERIA: Only randomised controlled trials (RCTs), including cluster-randomised (group-randomised) trials, that considered preconception advice given to individuals who perceived that they may be infertile and were investigating the possibility of medical treatment from subfertility specialist services were eligible for inclusion. The primary outcome was live birth, defined as delivery of a live fetus after 20 completed weeks of gestation. DATA COLLECTION AND ANALYSIS: Two review authors independently applied eligibility criteria to, extracted data from and assessed the risk of bias in the single included trial. MAIN RESULTS: One trial assessing smoking cessation advice for 94 infertile women smokers fulfilled the criteria for this review, but the trial did not report on the review's primary outcome of live birth or any other fertility-related outcomes. This trial of women attending a fertility clinic showed that smoking cessation advice tailored to a woman's "stage-of-change" (readiness to stop smoking) did not show significant evidence of a difference in stage (including smoking cessation rates) compared with standard clinical advice. AUTHORS' CONCLUSIONS: No RCTs were located that assessed the effects of preconception advice on the chance of a live birth or other fertility outcomes in people who perceived that they may be infertile and were investigating the possibility of medical treatment to address subfertility. Given the lack of RCTs evaluating the effectiveness of preconception lifestyle advice for people in the afore-mentioned population, this review cannot provide guidance for clinical practice in this area. However, it does highlight the need for further research into this important subject.


Assuntos
Infertilidade/terapia , Estilo de Vida , Cuidado Pré-Concepcional/métodos , Abandono do Hábito de Fumar , Aconselhamento/métodos , Feminino , Humanos , Nascido Vivo
12.
Aust N Z J Obstet Gynaecol ; 50(1): 8-20, 2010 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-20218991

RESUMO

BACKGROUND: Clinical infertility is a prevalent problem with significant financial and psychosocial costs. Modifiable lifestyle factors exist that may affect a person's time to conception and their chance of having a healthy, live birth. However, no guideline delineates what preconception advice should be offered to people presenting for infertility treatment. AIM: The aim of this article is to review the literature regarding modifiable lifestyle factors in people seeking infertility treatment. RESULTS: A person's time to pregnancy and their chance of having a healthy, live birth may be affected by factors such as weight, vitamin and iodine intake, alcohol and caffeine consumption, smoking, substance abuse, stress, environmental pollutants, vaccinations and oxidative stress. CONCLUSIONS: Advice on modifiable lifestyle factors should be given to people presenting for infertility treatment to help them make positive changes that may improve their chances of pregnancy and delivering a healthy, live baby. Developing a guideline for this would be a prudent step towards helping clinicians to implement this aspect of preconception care.


Assuntos
Infertilidade Feminina/etiologia , Infertilidade Masculina/etiologia , Estilo de Vida , Feminino , Comportamentos Relacionados com a Saúde , Humanos , Infertilidade Feminina/metabolismo , Infertilidade Masculina/metabolismo , Masculino , Obesidade/complicações , Estresse Oxidativo , Gravidez , Fumar/efeitos adversos
13.
Org Biomol Chem ; 7(13): 2756-60, 2009 Jul 07.
Artigo em Inglês | MEDLINE | ID: mdl-19532992

RESUMO

A ditopic tetrapodal imidazolium-based 1,3-alternate calix[4]arene host binds anions as 1 : 2 complexes via a range of CH...anion hydrogen bonds. Allosteric enhancement of the affinity for the second chloride anion is observed. X-Ray crystal structures of the chloride, bromide and nitrate complexes suggest that this behaviour is linked to inter-binding site communication mediated by the calixarene framework. The imidazolium groups exist as either in-out or out-out conformers with respect to the calixarene, with the chloride complex exhibiting conformational isomorphism such that both forms are present in the same crystal structure.


Assuntos
Brometos/química , Calixarenos/química , Cloretos/química , Imidazóis/química , Nitratos/química , Fenóis/química , Ânions/química , Cristalografia por Raios X , Ligação de Hidrogênio , Modelos Moleculares , Estrutura Molecular
14.
Dalton Trans ; (21): 4181-9, 2009 Jun 07.
Artigo em Inglês | MEDLINE | ID: mdl-19452068

RESUMO

The structures adopted by a range of hydrotris(3,5-dimethylpyrazolyl)methane complexes [ML(2){HC(pz')(3)}](+) (M = Rh, Ir; L(2) = diene) have been investigated. There is low steric hindrance between ligands in [Rh(eta-nbd){HC(pz')(3)}](+) (nbd = norbornadiene) and [Rh(eta-dmbd){HC(pz')(3)}](+) (dmbd = 2,3-dimethylbuta-1,3-diene) resulting in kappa(3) co-ordination of the pyrazolylmethane. The complexes [M(eta-cod){HC(pz')(3)}](+) (cod = cycloocta-1,5-diene) (M = Rh, Ir) are kappa(2) co-ordinated with the free pyrazolyl ring positioned above and approximately parallel to the square plane about rhodium or iridium. The HC(pz')(3) complexes undergo fast exchange of the co-ordinated and unco-ordinated pyrazolyl rings on the NMR spectroscopic timescale. However, for [Rh(eta-dmbd){HC(pz')(3)}](+), the fluxional process is slowed at low temperatures, so that inequivalent pyrazolyl rings may be observed. A mechanism for the fluxional process is proposed involving dynamic interconversion between isomeric forms in solution. The bonding mode of the HC(pz')(3) ligand can be determined by (13)C NMR spectroscopy. The (13)C chemical shifts (for the sp(3) hybridised carbon of the ligand) show the general pattern, kappa(3) < 71.5 ppm < kappa(2). The electrochemical behaviour of the pyrazolylmethane complexes is related to the degree of structural change, which occurs on electron transfer and is compared with that of the pyrazolylborate analogues.

15.
Dalton Trans ; (3): 530-43, 2009 Jan 21.
Artigo em Inglês | MEDLINE | ID: mdl-19122911

RESUMO

The d4 halide complexes [MX(CO)(eta-RC[triple bond, length as m-dash]CR)Tp'] [R = Me, M = W, X = F; R = Ph, M = Mo or W, X = F or Cl; Tp' = hydrotris(3,5-dimethylpyrazolyl)borate] undergo two-electron oxidation in the presence of a halide source to give the d2 monocations [MX1X2(eta-PhC[triple bond, length as m-dash]CPh)Tp']+ (R = Me, M = W, X1 = X2 = F; R = Ph, M = Mo, X1 = X2 = F or Cl; M = W, X1 = X2 = F or Cl; X1 = F, X2 = Cl). Each monocation (R = Ph) shows two reversible one-electron reductions (the second process was not detected for R = Me) corresponding to the stepwise formation of the neutral d3 and monoanionic d4 analogues, [MX1X2(eta-PhC[triple bond, length as m-dash]CPh)Tp'] and [MX1X2(eta-PhC[triple bond, length as m-dash]CPh)Tp']- respectively; the potentials for the two processes can be 'tuned' over a range of ca. 1.0 V by varying M and X. Chemical one-electron reduction of [MX2(eta-PhC[triple bond, length as m-dash]CPh)Tp']+ gave [MX2(eta-PhC[triple bond, length as m-dash]CPh)Tp'] (M = Mo or W, X = F or Cl). X-Ray structural studies on the redox pairs [WX2(eta-PhC[triple bond, length as m-dash]CPh)Tp']z (X = F and Cl, z = 0 and 1+) show the alkyne to bisect the X-W-X angle in the d2 cations but align more closely with one M-X bond in the neutral d3 molecules, consistent with the anisotropic ESR spectra of the latter; the solution ESR spectrum of [MoF2(eta-PhC[triple bond, length as m-dash]CPh)Tp'] showed equivalent fluorine atoms, i.e the alkyne oscillates at room temperature. The successful isolation of [MX2(eta-PhC[triple bond, length as m-dash]CPh)Tp']+ and [MX2(eta-PhC[triple bond, length as m-dash]CPh)Tp'] completes a series in which d6 to d2 alkyne complexes are linked in a redox family tree by sequential one-electron transfer and substitution reactions. The implications for such trees in the production of new species and the selective synthesis of paramagnetic complexes acting as synthetically useful 'alkyne radicals' are discussed.

16.
Dalton Trans ; (20): 2680-92, 2008 May 28.
Artigo em Inglês | MEDLINE | ID: mdl-18688399

RESUMO

The structures adopted by a range of poly(pyrazolyl)borate complexes [ML2Tp(x)] [M = Rh, Ir; L2 = diene; Tp(x) = Bp' {dihydrobis(3,5-dimethylpyrazolyl)borate}, Tp' {hydrotris(3,5-dimethylpyrazolyl)borate}, Tp {hydrotris(pyrazolyl)borate}, B(pz)4 {tetrakis(pyrazolyl)borate}] have been investigated. Low steric hindrance between ligands in [Rh(eta-nbd)Tp] (nbd = norbornadiene), [Rh(eta-cod)Tp] (cod = cycloocta-1,5-diene) and [Rh(eta-nbd)Tp'] results in K3 coordination of the pyrazolylborate but [M(eta-cod)Tp'] (M = Rh, Ir) are kappa2 coordinated with the free pyrazolyl ring positioned above and approximately parallel to the square plane about the metal. All but the most sterically hindered Tp(x) complexes undergo fast exchange of the coordinated and uncoordinated pyrazolyl rings on the NMR spectroscopic timescale. For [Rh(eta-cod){B(pz)4}], [Rh(eta-dmbd)Tp'] (dmbd = 2,3-dimethylbuta-1,3-diene) and [Rh(eta-cod)Tp(Ph)] {Tp(Ph) = hydrotris(3-phenylpyrazolyl)borate} the fluxional process is slowed at low temperatures so that inequivalent pyrazolyl rings are observed. The bonding modes of the Tp' ligand (but not of other pyrazolylborate ligands) can be determined by 11B NMR and IR spectroscopy. The 11B chemical shifts (for a series of Tp' complexes) show the general pattern, kappa3 < -7.5 ppm < kappa2 and the nu(BH) stretch kappa3 > 2500 cm(-1) > kappa2. The electrochemical behaviour of the pyrazolylborate complexes is related to the degree of structural change which occurs on electron transfer. One-electron oxidation of complexes with Tp', Tp and B(pz)4 ligands is generally reversible although that of [Ir(etacod)Tp] is only reversible at higher scan rates and that of [Ir(eta-cod){B(pz)4}] is irreversible. Of the complexes with the more sterically hindered Tp(Ph) ligand, only [Rh(eta-nbd)Tp(Ph)] shows any degree of reversible oxidation. The ESR spectra of a range of Rh(II) complexes show coupling to both 14N and 103Rh nuclei in most cases but what appears to be coupling to rhodium and one hydrogen atom, possibly a hydride ligand, for the oxidation product of [Rh(eta-nbd)Tp(Ph)].

17.
Chem Commun (Camb) ; (32): 3720-2, 2008 Aug 28.
Artigo em Inglês | MEDLINE | ID: mdl-18685755

RESUMO

A relatively inflexible 1D coordination polymer is induced to adopt either planar or quintuple helical supramolecular isomers according to the hydrogen bonding demands of the counter anions.

18.
Med Teach ; 30(8): 787-94, 2008.
Artigo em Inglês | MEDLINE | ID: mdl-18608966

RESUMO

BACKGROUND: Doctors' clinical reasoning ability significantly impacts upon their level of clinical competence. Throughout medical training students are given the opportunity to develop their reasoning ability in order to become appropriately clinically competent by graduation. AIM: To develop an instrument to assess students' reasoning ability on a written case-based question which was aligned to their learning in a PBL program. METHOD: An instrument with 10 criteria centred upon hypothesis generation, learning issues and mechanistic explanations was developed. Experienced clinical and medical educators validated the instrument, prior to its use with 145 undergraduate first-year medical students. RESULTS: The results enabled the establishment of the strengths and weaknesses in the reasoning performances of individuals, as well as the overall cohort. The instrument's Cronbach alpha coefficient was 0.94, and it had high inter-rater and intra-rater reliability. Further validation of the instrument's performance was established through qualitative evidence derived from student interviews and tutor reports for this cohort. CONCLUSIONS: Aligning written assessment to the PBL process enables students and teachers to better understand how the reasoning process is developing for individuals and a cohort, and provides a basis for further investigation into the development of student clinical reasoning.


Assuntos
Educação de Graduação em Medicina , Avaliação Educacional/métodos , Aprendizagem Baseada em Problemas , Pensamento , Adolescente , Humanos , Entrevistas como Assunto , Adulto Jovem
19.
Chemistry ; 14(24): 7296-305, 2008.
Artigo em Inglês | MEDLINE | ID: mdl-18613165

RESUMO

The synthesis of a series of ruthenium(II) based anion sensors of the type [Ru(eta(6)-C(6)H(4)MeCHMe(2))Cl(L)(2)][BF(4)] (2) is reported in which ligand L represents a series of substituted pyridinylmethyl-amine derivatives. The carbazole based ligand L(3) exhibits a fluorescent intraligand charge-transfer (ILCT) state that is quenched by ligand-to-metal charge transfer (LMCT) upon coordination to ruthenium in the 1:1 complex [Ru(eta(6)-C(6)H(4)MeCHMe(2))Cl(2)(L(3))] (1 c). The 1:2 complex 2 c is fluorescent, however, and acts as a fluorescent anion sensor because of the mixing of an anion-dependent charge-transfer component into the excited state. The 1:2 complexes of type 2 all exhibit interesting low symmetry (1)H NMR spectra that also are a useful handle on anion complexation. The electronic structures of L(3), 1 c and 2 c have been probed by time-dependent DFT calculations.

20.
Clin Cancer Res ; 14(6): 1775-81, 2008 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-18347179

RESUMO

PURPOSE: Conventional renal cell carcinoma (RCC) has a variable natural history, and determining individual prognosis is important to guide management. We have examined the prognostic significance of a large number of hematologic and biochemical variables, as well as traditional tumor-related factors in patients with RCC. EXPERIMENTAL DESIGN: Patients undergoing nephrectomy for newly diagnosed RCC between September 1998 and March 2005 were invited to participate. Clinical, pathologic, and laboratory data were recorded in each case, and immunophenotyping was carried out on a subset of patients. A planned subset analysis of patients presenting with N0M0 disease was done. RESULTS: Two hundred twelve patients with RCC formed the study population. In addition to tumor-related factors, multivariate analyses revealed preoperative serum sodium concentration to be independently and significantly associated with overall survival and disease-free survival when considered as both a continuous variable and when dichotomized to above and below the median value [139 mmol/L; reference range 135-145 mmol/L, hazard ratio 0.44, 95% confidence interval (95% CI) 0.22-0.88, P = 0.014]. Five-year overall survival estimates for patients above and below the median serum sodium were 67.6% (95% CI 54.2-80.9) and 44.3% (95% CI 32.8-55.8), respectively. These findings persisted in the N0M0 subgroup analysis. CONCLUSIONS: We have confirmed the prognostic value of traditional tumor-related factors but, to our knowledge, these are the first data to show that low preoperative sodium concentration may be an important factor associated with reduced survival in patients with RCC, suggesting that serum sodium should be considered with established prognostic variables in modeling survival in RCC.


Assuntos
Carcinoma de Células Renais/diagnóstico , Carcinoma de Células Renais/mortalidade , Neoplasias Renais/diagnóstico , Neoplasias Renais/mortalidade , Sódio/sangue , Adulto , Idoso , Idoso de 80 Anos ou mais , Algoritmos , Carcinoma de Células Renais/sangue , Carcinoma de Células Renais/cirurgia , Estudos Transversais , Feminino , Humanos , Neoplasias Renais/sangue , Neoplasias Renais/cirurgia , Masculino , Pessoa de Meia-Idade , Modelos Teóricos , Análise Multivariada , Prognóstico , Análise de Sobrevida
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