Publications by authors named "Hobday C"

This 62-minute webcast features a conversation about "Women and the Heart: Gender-Related Differences in Cardiovascular Care"-the focus of Issue 20.2. Led by the issue's editor, the discussion engages the authors on emerging themes and lessons learned while researching and writing the articles.

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By virtue of their open network structures and low densities, metal-organic frameworks (MOFs) are soft materials that exhibit elastic instabilities at low applied stresses. The conventional strategy for improving elastic stability is to increase the connectivity of the underlying MOF network, which necessarily increases the material density and reduces the porosity. Here we demonstrate an alternative paradigm, whereby elastic stability is enhanced in a MOF with an aperiodic network topology.

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According to the American College of Obstetricians and Gynecologists (ACOG), women who have a systolic blood pressure ≥ 140 mm Hg and/or a diastolic pressure ≥ 90 mm Hg before pregnancy or before 20 weeks of gestation have chronic hypertension. Up to 1.5% of women in their childbearing years have a diagnosis of chronic hypertension, and 16% of pregnant women develop hypertension during their pregnancy.

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is delighted to introduce a Collection of research works focused on the modelling and advanced characterization of framework materials. Here, the Guest Editors outline the themes within and look towards the future of the field.

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Postsynthetic modification of metal-organic frameworks (MOFs) has proven to be a hugely powerful tool to tune physical properties and introduce functionality, by exploiting reactive sites on both the MOF linkers and their inorganic secondary building units (SBUs), and so has facilitated a wide range of applications. Studies into the reactivity of MOF SBUs have focussed solely on removal of neutral coordinating solvents, or direct exchange of linkers such as carboxylates, despite the prevalence of ancillary charge-balancing oxide and hydroxide ligands found in many SBUs. Herein, we show that the μ-OH ligands in the MIL-53 topology Sc MOF, GUF-1, are labile, and can be substituted for μ-OCH units through reaction with pore-bound methanol molecules in a very rare example of pressure-induced postsynthetic modification.

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Major depressive disorder during pregnancy can be detrimental to the fetus and patient. Treatments can include electroconvulsive therapy (ECT) for severe cases. The use of ketamine in ECT can provide symptomatic relief as well as induce anesthesia.

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The high-pressure behaviour of flexible zeolitic imidazolate frameworks (ZIFs) of the ZIF-62 family with the chemical composition M(im) (bim) is presented (M =Zn , Co ; im =imidazolate; bim =benzimidazolate, 0.02≤x≤0.37).

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Article Synopsis
  • - Miniaturization in materials science is essential, as the size and shape of porous framework materials (like metal-organic frameworks) significantly impact their physical and chemical properties.
  • - Understanding how crystal size and morphology influence structure and behavior is challenging due to the complex, multiscale nature of these effects, and there’s a lack of comprehensive insight into these dynamics.
  • - The article emphasizes the importance of controlling crystal size and shape for practical applications, such as drug delivery, and suggests that advances in computational tools could help model these multifaceted effects and enhance material design.
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Crystalline coordination polymers are a chemically diverse material platform that provide control over network geometry and chemical interactions, harbouring a wealth of phenomena of large scientific and technological relevance. The underlying structure together with chemical interactions play a crucial role, factors that together determine the underlying free energy surface of a material, i.e.

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Flexible metal-organic frameworks (MOFs) show large structural flexibility as a function of temperature or (gas)pressure variation, a fascinating property of high technological and scientific relevance. The targeted design of flexible MOFs demands control over the macroscopic thermodynamics as determined by microscopic chemical interactions and remains an open challenge. Herein we apply high-pressure powder X-ray diffraction and molecular dynamics simulations to gain insight into the microscopic chemical factors that determine the high-pressure macroscopic thermodynamics of two flexible pillared-layer MOFs.

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Zinc(ii) and zirconium(iv) metal-organic frameworks show uptake and slow release of the ant alarm pheromones 3-octanone and 4-methyl-3-heptanone. Inclusion of N-propyl groups on the MOFs allows for enhanced uptake and release over several months. In preliminary field trials, leaf cutting ants show normal behavioural responses to the released pheromones.

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Conformational changes of linker units in metal-organic frameworks (MOFs) are often responsible for gate-opening phenomena in selective gas adsorption and stimuli-responsive optical and electrical sensing behaviour. Herein, we show that pressure-induced bathochromic shifts in both fluorescence emission and UV/Vis absorption spectra of a two-fold interpenetrated Hf MOF, linked by 1,4-phenylene-bis(4-ethynylbenzoate) ligands (Hf-peb), are induced by rotation of the central phenyl ring of the linker, from a coplanar arrangement to a twisted, previously unseen conformer. Single-crystal X-ray diffraction, alongside in situ fluorescence and UV/Vis absorption spectroscopies, measured up to 2.

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The crystal structure of 4-iodobenzonitrile, which is monoclinic (space group 2/) under ambient conditions, contains chains of molecules linked through C≡N···I halogen-bonds. The chains interact through CH···I, CH···N and π-stacking contacts. The crystal structure remains in the same phase up to 5.

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Metal-organic frameworks (MOFs) are coordination networks with organic ligands containing potential voids. Some MOFs show pronounced structural flexibility that may result in closing and re-opening these pores. Here, we show that collective flexibility in a MOF-DUT-8(Ni) - is controlled by conformational isomerism.

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The incorporation of defects into crystalline materials provides an important tool to fine-tune properties throughout various fields of materials science. We performed high-pressure powder X-ray diffraction experiments, varying pressures from ambient to 0.4 GPa in 0.

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Some porous crystalline solids change their structure upon guest inclusion. Unlocking the potential of these solids for a wide variety of applications requires full characterisation of the response to adsorption and the underlying framework-guest interactions. Here, we introduce an approach to understanding gas uptake in porous metal-organic frameworks (MOFs) by loading liquefied gases at GPa pressures inside the Zn-based framework ZIF-8.

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A fully interpenetrated 8,3-connected zirconium MOF with the the-i topology type, STA-26 (St Andrews porous material-26), has been prepared using the 4,4',4"-(2,4,6-trimethylbenzene-1,3,5-triyl)tribenzoate (TMTB) tritopic linker with formic acid as a modulating agent. In the as-prepared form STA-26 possesses Im3‾ m symmetry compared with the Pm3‾ m symmetry of the non-interpenetrated analogue, NU-1200, prepared using benzoic acid as a modulator. Upon removal of residual solvent there is a shift between the interpenetrating lattices and a resultant symmetry change to Cmcm which is fully reversible.

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Many zeolitic imidazolate frameworks (ZIFs) are promising candidates for use in separation technologies. Comprising large cavities interconnected by small windows they can be used, at least in principle, as molecular sieves where molecules smaller than the window size are able to diffuse into the material while larger molecules are rejected. However, "swing effect" or "gate opening" phenomena resulting in an enlargement of the windows have proven to be detrimental.

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By decoupling the mechanical behaviour of building units for the first time in a wine-rack framework containing two different strut types, we show that lithium l-tartrate exhibits NLC with a maximum value, K = -21 TPa, and an overall NLC capacity, χ = 5.1%, that are comparable to the most exceptional materials to date. Furthermore, the contributions from molecular strut compression and angle opening interplay to give rise to so-called "hidden" negative linear compressibility, in which NLC is absent at ambient pressure, switched on at 2 GPa and sustained up to the limit of our experiment, 5.

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Whilst many metal-organic frameworks possess the chemical stability needed to be used as functional materials, they often lack the physical strength required for industrial applications. Herein, we have investigated the mechanical properties of two UiO-topology Zr-MOFs, the planar UiO-67 ([Zr6O4(OH)4 (bpdc)6], bpdc: 4,4'-biphenyl dicarboxylate) and UiO-abdc ([Zr6O4(OH)4 (abdc)6], abdc: 4,4'-azobenzene dicarboxylate) by single-crystal nanoindentation, high-pressure X-ray diffraction, density functional theory calculations, and first-principles molecular dynamics. On increasing pressure, both UiO-67 and UiO-abdc were found to be incompressible when filled with methanol molecules within a diamond anvil cell.

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A new member of the UiO-66 series of zirconium metal-organic frameworks (MOFs) is reported, and the postsynthetic bromination of its integral alkene moeities in a single-crystal to single-crystal manner is fully characterised. Nanoindentation is used to probe the bromination of unsaturated carbon-carbon bonds, in it and an analogous Zr MOF, which leads to more compliant materials with lower elastic moduli.

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Background: The current management strategy for women with low-grade squamous intraepithelial lesions (LSILs) is inefficient and expensive because of the inability to identify patients at high risk for disease progression. The current study was designed to determine the genotypic patterns of human papillomavirus (HPV) associated with the persistence and progression of cervical lesions in women with an initial interpretation of LSIL.

Methods: One hundred sixty-seven women with LSIL on Papanicolaou tests collected between December 1, 2009 and March 30, 2011 were studied.

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Background: Women in the 1940s-1960s were prescribed diethylstilbestrol (DES), a nonsteroidal estrogen, to prevent miscarriages, but the practice was terminated after it was discovered that the daughters so exposed in utero were at increased risk for developing clear cell adenocarcinoma (CCA) of the vagina or cervix at early ages. Pap smear screening is one of the principal methods used to identify tumor development and is necessary in this group of women to maintain their health. Currently, little is known about the factors associated with nonutilization of this screening tool in this high-risk population of women.

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Aim: A randomized controlled trial was carried out to study the effect of a recently proposed technique of ex vivo intra-arterial methylene blue injection of the surgical specimen removed for colorectal cancer on lymph node harvest and staging.

Method: Between May 2012 and February 2013, 100 consecutive colorectal cancer resection specimens in a single institution were randomly assigned to intervention (methylene blue injection) and control (standard manual palpation technique) groups before formalin fixation. The specimen was then examined by the histopathologist for lymph nodes.

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