72 research outputs found
SOLIS: Autonomous Solubility Screening using Deep Neural Networks
Accelerating material discovery has tremendous societal and industrial
impact, particularly for pharmaceuticals and clean energy production. Many
experimental instruments have some degree of automation, facilitating
continuous running and higher throughput. However, it is common that sample
preparation is still carried out manually. This can result in researchers
spending a significant amount of their time on repetitive tasks, which
introduces errors and can prohibit production of statistically relevant data.
Crystallisation experiments are common in many chemical fields, both for
purification and in polymorph screening experiments. The initial step often
involves a solubility screen of the molecule; that is, understanding whether
molecular compounds have dissolved in a particular solvent. This usually can be
time consuming and work intensive. Moreover, accurate knowledge of the precise
solubility limit of the molecule is often not required, and simply measuring a
threshold of solubility in each solvent would be sufficient. To address this,
we propose a novel cascaded deep model that is inspired by how a human chemist
would visually assess a sample to determine whether the solid has completely
dissolved in the solution. In this paper, we design, develop, and evaluate the
first fully autonomous solubility screening framework, which leverages
state-of-the-art methods for image segmentation and convolutional neural
networks for image classification. To realise that, we first create a dataset
comprising different molecules and solvents, which is collected in a real-world
chemistry laboratory. We then evaluated our method on the data recorded through
an eye-in-hand camera mounted on a seven degree-of-freedom robotic manipulator,
and show that our model can achieve 99.13% test accuracy across various setups.Comment: 7 pages, 4 figure
Powder-Bot: A Modular Autonomous Multi-Robot Workflow for Powder X-Ray Diffraction
Powder X-ray diffraction (PXRD) is a key technique for the structural
characterisation of solid-state materials, but compared with tasks such as
liquid handling, its end-to-end automation is highly challenging. This is
because coupling PXRD experiments with crystallisation comprises multiple solid
handling steps that include sample recovery, sample preparation by grinding,
sample mounting and, finally, collection of X-ray diffraction data. Each of
these steps has individual technical challenges from an automation perspective,
and hence no commercial instrument exists that can grow crystals, process them
into a powder, mount them in a diffractometer, and collect PXRD data in an
autonomous, closed-loop way. Here we present an automated robotic workflow to
carry out autonomous PXRD experiments. The PXRD data collected for polymorphs
of small organic compounds is comparable to that collected under the same
conditions manually. Beyond accelerating PXRD experiments, this workflow
involves 13 component steps and integrates three different types of robots,
each from a separate supplier, illustrating the power of flexible, modular
automation in complex, multitask laboratories.Comment: 11 pages, 4 figures plus Supporting Information (2 videos, 13
supporting figures and one table
Autonomous biomimetic solid dispensing using a dual-arm robotic manipulator
An automated solid dispenser was developed using a dual-arm robot and fuzzy logic controller, mimicking the operations of human researchers.</jats:p
Metal-organic framework crystal-glass composites.
The majority of research into metal-organic frameworks (MOFs) focuses on their crystalline nature. Recent research has revealed solid-liquid transitions within the family, which we use here to create a class of functional, stable and porous composite materials. Described herein is the design, synthesis, and characterisation of MOF crystal-glass composites, formed by dispersing crystalline MOFs within a MOF-glass matrix. The coordinative bonding and chemical structure of a MIL-53 crystalline phase are preserved within the ZIF-62 glass matrix. Whilst separated phases, the interfacial interactions between the closely contacted microdomains improve the mechanical properties of the composite glass. More significantly, the high temperature open pore phase of MIL-53, which spontaneously transforms to a narrow pore upon cooling in the presence of water, is stabilised at room temperature in the crystal-glass composite. This leads to a significant improvement of CO2 adsorption capacity
Liquid phase blending of metal-organic frameworks.
The liquid and glass states of metal-organic frameworks (MOFs) have recently become of interest due to the potential for liquid-phase separations and ion transport, alongside the fundamental nature of the latter as a new, fourth category of melt-quenched glass. Here we show that the MOF liquid state can be blended with another MOF component, resulting in a domain structured MOF glass with a single, tailorable glass transition. Intra-domain connectivity and short range order is confirmed by nuclear magnetic resonance spectroscopy and pair distribution function measurements. The interfacial binding between MOF domains in the glass state is evidenced by electron tomography, and the relationship between domain size and Tg investigated. Nanoindentation experiments are also performed to place this new class of MOF materials into context with organic blends and inorganic alloys
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Metal-organic framework and inorganic glass composites
Abstract: Metal-organic framework (MOF) glasses have become a subject of interest as a distinct category of melt quenched glass, and have potential applications in areas such as ion transport and sensing. In this paper we show how MOF glasses can be combined with inorganic glasses in order to fabricate a new family of materials composed of both MOF and inorganic glass domains. We use an array of experimental techniques to propose the bonding between inorganic and MOF domains, and show that the composites produced are more mechanically pliant than the inorganic glass itself
Healthcare Costs and Life-years Gained From Treatments Within the Advancing Cryptococcal Meningitis Treatment for Africa (ACTA) Trial on Cryptococcal Meningitis: A Comparison of Antifungal Induction Strategies in Sub-Saharan Africa
Background
Mortality from cryptoccocal meningitis remains high. The ACTA trial demonstrated that, compared with 2 weeks of amphotericin B (AmB) plus flucystosine (5FC), 1 week of AmB and 5FC was associated with lower mortality and 2 weeks of oral flucanozole (FLU) plus 5FC was non-inferior. Here, we assess the cost-effectiveness of these different treatment courses.
Methods
Participants were randomized in a ratio of 2:1:1:1:1 to 2 weeks of oral 5FC and FLU, 1 week of AmB and FLU, 1 week of AmB and 5FC, 2 weeks of AmB and FLU, or 2 weeks of AmB and 5FC in Malawi, Zambia, Cameroon, and Tanzania. Data on individual resource use and health outcomes were collected. Cost-effectiveness was measured as incremental costs per life-year saved, and non-parametric bootstrapping was done.
Results
Total costs per patient were US 1763 for 1 week of AmB and FLU, 2125 for 2 weeks of AmB and FLU, and 208 (95% confidence interval $91–1210) per life-year saved.
Conclusions
Both 1 week of AmB and 5FC and 2 weeks of Oral FLU and 5FC are cost-effective treatments
AIDS-related mycoses: the way forward.
The contribution of fungal infections to the morbidity and mortality of HIV-infected individuals is largely unrecognized. A recent meeting highlighted several priorities that need to be urgently addressed, including improved epidemiological surveillance, increased availability of existing diagnostics and drugs, more training in the field of medical mycology, and better funding for research and provision of treatment, particularly in developing countries
Albiglutide and cardiovascular outcomes in patients with type 2 diabetes and cardiovascular disease (Harmony Outcomes): a double-blind, randomised placebo-controlled trial
Background:
Glucagon-like peptide 1 receptor agonists differ in chemical structure, duration of action, and in their effects on clinical outcomes. The cardiovascular effects of once-weekly albiglutide in type 2 diabetes are unknown. We aimed to determine the safety and efficacy of albiglutide in preventing cardiovascular death, myocardial infarction, or stroke.
Methods:
We did a double-blind, randomised, placebo-controlled trial in 610 sites across 28 countries. We randomly assigned patients aged 40 years and older with type 2 diabetes and cardiovascular disease (at a 1:1 ratio) to groups that either received a subcutaneous injection of albiglutide (30–50 mg, based on glycaemic response and tolerability) or of a matched volume of placebo once a week, in addition to their standard care. Investigators used an interactive voice or web response system to obtain treatment assignment, and patients and all study investigators were masked to their treatment allocation. We hypothesised that albiglutide would be non-inferior to placebo for the primary outcome of the first occurrence of cardiovascular death, myocardial infarction, or stroke, which was assessed in the intention-to-treat population. If non-inferiority was confirmed by an upper limit of the 95% CI for a hazard ratio of less than 1·30, closed testing for superiority was prespecified. This study is registered with ClinicalTrials.gov, number NCT02465515.
Findings:
Patients were screened between July 1, 2015, and Nov 24, 2016. 10 793 patients were screened and 9463 participants were enrolled and randomly assigned to groups: 4731 patients were assigned to receive albiglutide and 4732 patients to receive placebo. On Nov 8, 2017, it was determined that 611 primary endpoints and a median follow-up of at least 1·5 years had accrued, and participants returned for a final visit and discontinuation from study treatment; the last patient visit was on March 12, 2018. These 9463 patients, the intention-to-treat population, were evaluated for a median duration of 1·6 years and were assessed for the primary outcome. The primary composite outcome occurred in 338 (7%) of 4731 patients at an incidence rate of 4·6 events per 100 person-years in the albiglutide group and in 428 (9%) of 4732 patients at an incidence rate of 5·9 events per 100 person-years in the placebo group (hazard ratio 0·78, 95% CI 0·68–0·90), which indicated that albiglutide was superior to placebo (p<0·0001 for non-inferiority; p=0·0006 for superiority). The incidence of acute pancreatitis (ten patients in the albiglutide group and seven patients in the placebo group), pancreatic cancer (six patients in the albiglutide group and five patients in the placebo group), medullary thyroid carcinoma (zero patients in both groups), and other serious adverse events did not differ between the two groups. There were three (<1%) deaths in the placebo group that were assessed by investigators, who were masked to study drug assignment, to be treatment-related and two (<1%) deaths in the albiglutide group.
Interpretation:
In patients with type 2 diabetes and cardiovascular disease, albiglutide was superior to placebo with respect to major adverse cardiovascular events. Evidence-based glucagon-like peptide 1 receptor agonists should therefore be considered as part of a comprehensive strategy to reduce the risk of cardiovascular events in patients with type 2 diabetes.
Funding:
GlaxoSmithKline
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The Development of Hybrid Liquids and Glasses
Abstract: The Development of Hybrid Liquids and Glasses
Louis Michael David Longley
Metal-organic framework (MOF) glasses are amorphous materials formed by heating a crystalline MOF into the liquid phase and then cooling to form an amorphous solid material. The hybrid nature, defined here as materials containing both inorganic and organic bonding, of MOF glasses makes them distinct from previous glass families which have inorganic, organic, or metallic bonding. Most of the work on MOF glasses reported in the literature has focused on a sub-set of MOFs known as Zeolitic Imidazolate Frameworks (ZIFs).
This work begins with a discussion of the structure of MOF glasses, particularly focusing on structure occurring beyond the first metal-metal correlation, also termed mid-range order. The observed midrange
order in MOF glasses, measured by X-ray total-scattering, is interpreted using existing theory for inorganic glasses.
The number of MOFs which form liquids on heating is small relative to the total number of known crystalline MOF structures due to decomposition of the framework occurring before melting in most cases. This work therefore takes an alternative approach to expanding the MOF glass domain through exploitation of the reactivity of the liquid phase as a route to the synthesis of new glass structures. ‘Complex’ glasses formed from two parent MOF crystals heated into the liquid phase were synthesised, and their structures investigated by a variety of techniques, including x-ray total-scattering, differential scanning calorimetry, and electron microscopy.
Following this work the scope of MOF glasses was further expanded through the production of composite materials of MOF and inorganic phosphate glasses. The structures and properties of these materials were also investigated thoroughly with attention being given to the interaction occurring at the interface between the two highly dissimilar components. Finally, as an extension of this, the interaction between a phosphate glass and a crystalline ZIF was investigated to probe the potential for inorganic glass crystalline MOF composite formation.Engineering and Physical Sciences Research Counci
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