38 research outputs found
Effect of Air Injection on Nucleation Rates: An Approach from Induction Time Statistics
From
disruption of the supersaturated solution to improved mass
transfer in the crystallizing suspension, the introduction of a moving
gas phase in a crystallizer could lead to improved rates of nucleation
and crystal growth. In this work, saturated air has been injected
to batch crystallizers to study the effects on formation of the first
crystal and subsequent turbidity buildup. To account for the typically
large sample-to-sample variation, nucleation rates were evaluated
for a large number of replicates using probability distributions of
induction times. The slope and the intercept of the distributions
were studied independently, allowing the simultaneous determination
of the mean induction time and a certain detection delay related to
the rate of crystal growth after formation of the first nucleus. When
saturated air was injected in aqueous glycine solutions, the average
detection delay was reduced from 69 to 13 min, and the mean induction
time decreased from 128 to 36 min. The effect on aqueous solutions
of l-arginine was less apparent, with a detection delay reduction
from 15 to 3 min, and no significant changes on the rate of primary
nucleation. These results demonstrate the potential of this technique
for reduction in nucleation induction time and improved mass deposition
rates in crystallization operations
Characterization of a Multistage Continuous MSMPR Crystallization Process assisted by Image Analysis of Elongated Crystals
This work demonstrates
how quantitative image analysis can assist
in the characterization of continuous crystallization processes and
in the proper selection of mathematical models for the early assessment
of crystal quality. An active pharmaceutical ingredient presenting
an elongated crystal habit was crystallized using two stirred tank
crystallizers in series. With image analysis of the crystallization
magma, the sources of crystal breakage in the crystallization cascade
were identified, and the impact on crystal habit was evaluated quantitatively.
As it is expected for particles presenting high aspect ratios, crystal
breakage preferentially occurs in the smallest plane, perpendicular
to the largest dimension. This phenomenon is hardly avoidable in downstream
production, but it can be accounted for with a design approach based
on the real crystal dimensions. The kinetic rate equations for nucleation
and crystal growth were determined based on crystal width, from which
a model for the accurate prediction of this dimension was applied.
The predicted crystal size distribution is consistent through a moderate
degree of crystal breakage during downstream processing
Effect of Air Injection on Nucleation Rates: An Approach from Induction Time Statistics
Impact of acute coronary syndrome on clinical outcomes after revascularization with the dual-therapy CD34 antibody-covered sirolimus-eluting Combo stent and the sirolimus-eluting Orsiro stent
OBJECTIVES: To compare the efficacy and safety of the dual-therapy CD34 antibody-covered sirolimus-eluting Combo stent (DTS) and the sirolimus-eluting Orsiro stent (O-SES) in patients with and without acute coronary syndrome (ACS) included in the SORT OUT X study.BACKGROUND: The incidence of target lesion failure (TLF) after treatment with modern drug-eluting stents has been reported to be significantly higher in patients with ACS when compared to patients without ACS. Whether the results from the SORT OUT X study apply to patients with and without ACS remains unknown.METHODS: In total, 3146 patients were randomized to stent implantation with DTS (n = 1578; ACS: n = 856) or O-SES (n = 1568; ACS: n = 854). The primary end point, TLF, was a composite of cardiac death, target-lesion myocardial infarction (MI), or target lesion revascularization (TLR) within 1 year.RESULTS: At 1 year, the rate of TLF was higher in the DTS group compared to the O-SES group, both among patients with ACS (6.7% vs. 4.1%; incidence rate ratio: 1.65 [95% confidence interval, CI: 1.08-2.52]) and without ACS (6.0% vs. 3.2%; incidence rate ratio: 1.88 [95% CI: 1.13-3.14]). The differences were mainly explained by higher rates of TLR, whereas rates of cardiac death and target lesion MI did not differ significantly between the two stent groups in patients with or without ACS CONCLUSION: Compared to the O-SES, the DTS was associated with a higher risk of TLF at 12 months in patients with and without ACS. The differences were mainly explained by higher rates of TLR.</p
Telomeres and the natural lifespan limit in humans
An ongoing debate in demography has focused on whether the human lifespan has a maximal natural limit. Taking a mechanistic perspective, and knowing that short telomeres are associated with diminished longevity, we examined whether telomere length dynamics during adult life could set a maximal natural lifespan limit. We define leukocyte telomere length of 5 kb as the 'telomeric brink', which denotes a high risk of imminent death. We show that a subset of adults may reach the telomeric brink within the current life expectancy and more so for a 100-year life expectancy. Thus secular trends in life expectancy should confront a biological limit due to crossing the telomeric brink
Targeted prevention in primary care aimed at lifestyle-related diseases:a study protocol for a non-randomised pilot study
Background: The consequences of lifestyle-related disease represent a major burden for the individual as well as for society at large. Individual preventive health checks to the general population have been suggested as a mean to reduce the burden of lifestyle-related diseases, though with mixed evidence on effectiveness. Several systematic reviews, on the other hand, suggest that health checks targeting people at high risk of chronic lifestyle-related diseases may be more effective. The evidence is however very limited. To effectively target people at high risk of lifestyle-related disease, there is a substantial need to advance and implement evidence-based health strategies and interventions that facilitate the identification and management of people at high risk. This paper reports on a non-randomized pilot study carried out to test the acceptability, feasibility and short-term effects of a healthcare intervention in primary care designed to systematically identify persons at risk of developing lifestyle-related disease or who engage in health-risk behavior, and provide targeted and coherent preventive services to these individuals. Methods: The intervention took place over a three-month period from September 2016 to December 2016. Taking a two-pronged approach, the design included both a joint and a targeted intervention. The former was directed at the entire population, while the latter specifically focused on patients at high risk of a lifestyle-related disease and/or who engage in health-risk behavior. The intervention was facilitated by a digital support system. The evaluation of the pilot will comprise both quantitative and qualitative research methods. All outcome measures are based on validated instruments and aim to provide results pertaining to intervention acceptability, feasibility, and short-term effects. Discussion: This pilot study will provide a solid empirical base from which to plan and implement a full-scale randomized study with the central aim of determining the efficacy of a preventive health intervention. Trial registration: Registered at Clinical Trial Gov (Unique Protocol ID: TOFpilot2016). Registered 29 April 2016. The study adheres to the SPIRIT guidelines
A Mouse Model that Recapitulates Cardinal Features of the 15q13.3 Microdeletion Syndrome Including Schizophrenia- and Epilepsy-Related Alterations
Rare and low-frequency coding variants alter human adult height
Height is a highly heritable, classic polygenic trait with ~700 common associated variants identified so far through genome - wide association studies . Here , we report 83 height - associated coding variants with lower minor allele frequenc ies ( range of 0.1 - 4.8% ) and effects of up to 2 16 cm /allele ( e.g. in IHH , STC2 , AR and CRISPLD2 ) , >10 times the average effect of common variants . In functional follow - up studies, rare height - increasing alleles of STC2 (+1 - 2 cm/allele) compromise d proteolytic inhibition of PAPP - A and increased cleavage of IGFBP - 4 in vitro , resulting in higher bioavailability of insulin - like growth factors . The se 83 height - associated variants overlap genes mutated in monogenic growth disorders and highlight new biological candidates ( e.g. ADAMTS3, IL11RA, NOX4 ) and pathways ( e.g . proteoglycan/ glycosaminoglycan synthesis ) involved in growth . Our results demonstrate that sufficiently large sample sizes can uncover rare and low - frequency variants of moderate to large effect associated with polygenic human phenotypes , and that these variants implicate relevant genes and pathways