586 research outputs found

    Modelling solution speciation to predict pH and supersaturation for design of batch and continuous organic salt crystallisation processes

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    Organic salt crystallisation is of great importance to the pharmaceutical industry as the majority of pharmaceutical products are marketed as salts. In this study a solution speciation model was developed and experimentally validated to predict pH and supersaturation during organic salt crystallisation processes when only the overall solution composition is known. By solving a particular system of equations simultaneously the full speciation and pH of the solution is calculated. Simply with knowledge of only the overall solution composition, dissociation constants and solubility products this model can be used to generate the design space for organic salt crystallisation and gain deeper understanding of the salt crystallisation process. In particular, the model can be used to calculate the maximum theoretical crystallisation yield and the corresponding mother liquor pH which would be impossible to determine otherwise without performing experiments. The case study used in this work is the polymorphic organic salt ethylenediammonium 3,5-dinitrobenzoate (EDNB) which is the 2:1 salt of 3,5-dinitrobenzoic acid (3,5-DNBA) with ethylenediamine. In this system three solid forms can be produced: EDNB monoclinic, EDNB triclinic and/or the 3,5-dinitrobenzoic acid (3,5-DNBA) starting material. The solution speciation model was used to investigate the crystallisation process for each solid form and test different feed molar ratios and different solution addition/mixing approaches for semi-batch and continuous processes

    Crystallographic MAD Phasing Strategies Explored Using ELETTRA Sincrotrone Mn K-Edge Data to 2.1 Å and Use of CHESS Establishes the Diffraction Resolution Limit as 0.92 Å for the Protein Mn, Ca Concanavalin A

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    Multiwavelength anomalous dispersion (MAD) data have been collected from a single crystal of the protein concanavalin A so as to evaluate different combinations of wavelengths for crystallographic structure determination. Data were recorded to 2.1 Å resolution on a flash frozen crystal at three wavelengths about the Mn K-edge (1.8951 Å, 1.8940 Å, 1.800 Å) using synchrotron radiation at ELETTRA\u27s Sincrotrone Trieste \u27XRD\u27 beamline. This is one of the longest wavelength K-edge MAD studies undertaken to date. Anomalous and dispersive Patterson maps are seen to be of high quality and indicate a high occupancy for the manganese binding site. This is confirmed also in the MAD phase determination and electron density maps. Finally 0.92 Å data recorded at CHESS indicates the prospects available for combined phasing strategies based on MAD to medium/high resolution along with ultra high resolution data

    Schistosoma mansoni cercarial elastase (SmCE): differences in immunogenic properties of native and recombinant forms

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    The Schistosoma mansoni cercarial elastase (SmCE) has previously been shown to be poorly immunogenic in mice. However, a minority of mice were able to produce antibodies against SmCE after multiple immunizations with crude pre- parations containing the enzyme. These mice were partially protected against challenge infections of S. mansoni. In the present study, we show that in contrast to the poor immunogenicity of the enzymatically active native form of SmCE derived from a crude preparation (cercarial transformation fluid), immunization of CBA/Ca mice with two enzymatically inactive forms, namely purified native SmCE or a recombinant SmCE fused to recombinant Schistosoma japonicum gluta- thione S-transferase (rSmCE-SjGST), after adsorption onto aluminum hydroxide adjuvant, induced specific anti-SmCE immunoglobulin G (IgG) in all mice within 2 weeks of the second immunization. The IgG antibody response to rSmCE- SjGST was mainly of the IgG1 subclass. These results suggest that inactive forms of the antigen could be used to obtain the optimum immunogenic effects as a vaccine candidate against schistosomiasis. Mice immunized with the rSmCE- SjGST on alum had smaller mean worm burdens and lower tissue egg counts when compared with adjuvant alone- and recombinant SjGST-injected controls. The native SmCE was antigenically cross-reactive with homologous enzymes of Schistosoma haematobium and Schistosoma margrebowiei

    Validation of a diagnosis-agnostic symptom questionnaire for asthma and/or COPD

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    ACKNOWLEDGEMENTS The authors wish to acknowledge the work of the NOVELTY study investigators, who are listed in full in the supplementary material, and Sharon MacLachlan (Evidera, London, UK), who participated in the analysis of sections of the data. Medical writing support, under the direction of the authors, was provided by Lauren McNally, MSci, CMC Connect, McCann Health Medical Communications, and was funded by AstraZeneca, Cambridge, UK, in accordance with Good Publication Practice (GPP3) guidelines (Ann Intern Med 2015; 163: 461–464). Support statement: The NOVELTY study is funded by AstraZenecaPeer reviewedPublisher PD

    Methods for managing miscarriage:a network meta-analysis

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    This is a protocol for a Cochrane Review (Intervention). The objectives are as follows:The objectives of this review are:• to estimate the relative effectiveness and safety profiles for methods of management of miscarriage;• to provide a ranking of the available methods according to their effectiveness and safety profile

    Chronic Airways Assessment Test : Psychometric properties in patients with asthma and/or COPD

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    Acknowledgements The authors would like to thank the patients who participated in this study and wish to acknowledge the work of the NOVELTY Scientific Community and the NOVELTY study investigators, who are listed in full below, and Sharon MacLachlan (Evidera, London, UK), who participated in the analysis of sections of the data. Medical writing support, under the direction of the authors, was provided by Niall Tyrer, MBiolSci, CMC Connect, a division of IPG Health Medical Communications, funded by AstraZeneca, Cambridge, UK, in accordance with Good Publication Practice (GPP 2022) guidelines (Ann Intern Med 2022; 175(9):1298–1304). Funding The NOVELTY study was funded by AstraZeneca.Peer reviewedPublisher PD

    An observational study of patient characteristics associated with the mode of admission to acute stroke services in North East, England

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    Objective Effective provision of urgent stroke care relies upon admission to hospital by emergency ambulance and may involve pre-hospital redirection. The proportion and characteristics of patients who do not arrive by emergency ambulance and their impact on service efficiency is unclear. To assist in the planning of regional stroke services we examined the volume, characteristics and prognosis of patients according to the mode of presentation to local services. Study design and setting A prospective regional database of consecutive acute stroke admissions was conducted in North East, England between 01/09/10-30/09/11. Case ascertainment and transport mode were checked against hospital coding and ambulance dispatch databases. Results Twelve acute stroke units contributed data for a mean of 10.7 months. 2792/3131 (89%) patients received a diagnosis of stroke within 24 hours of admission: 2002 arrivals by emergency ambulance; 538 by private transport or non-emergency ambulance; 252 unknown mode. Emergency ambulance patients were older (76 vs 69 years), more likely to be from institutional care (10% vs 1%) and experiencing total anterior circulation symptoms (27% vs 6%). Thrombolysis treatment was commoner following emergency admission (11% vs 4%). However patients attending without emergency ambulance had lower inpatient mortality (2% vs 18%), a lower rate of institutionalisation (1% vs 6%) and less need for daily carers (7% vs 16%). 149/155 (96%) of highly dependent patients were admitted by emergency ambulance, but none received thrombolysis. Conclusion Presentations of new stroke without emergency ambulance involvement were not unusual but were associated with a better outcome due to younger age, milder neurological impairment and lower levels of pre-stroke dependency. Most patients with a high level of pre-stroke dependency arrived by emergency ambulance but did not receive thrombolysis. It is important to be aware of easily identifiable demographic groups that differ in their potential to gain from different service configurations
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