393 research outputs found
Prediction of Soakout Time Using Analytical Models
In precision manufacturing enterprises, machine parts at nonstandard temperatures are often soaked to standard temperature prior to making any dimensional measurements. The soakout times are usually determined using lumped heat-transfer models where the part temperatures are assumed to be uniform. This article discusses conditions under which lumped model assumptions are valid by comparing lumped analyses for various shapes and materials with the more general finite element results. In addition, the effect of ambient temperature cycling on part response is also studied
MiR203 Mediates Subversion of Stem Cell Properties During Mammary Epithelial Differentiation via Repression of ΔNP63α and Promotes Mesenchymal-to-Epithelial Transition
During reproductive life, the mammary epithelium undergoes consecutive cycles of proliferation, differentiation and apoptosis. Doing so relies on the retained proliferative capacity, prolonged lifespan and developmental potency of mammary stem cells (MaSCs). ΔNp63α, the predominant TP63 isoform in mammary epithelia, is robustly expressed in MaSCs and is required for preservation of self-renewing capacity in diverse epithelial structures. However, the mechanism(s) underlying subversion of this activity during forfeiture of self-renewing capacity are poorly understood. MicroRNAs (miRNAs) govern critical cellular functions including stem cell maintenance, development, cell cycle regulation and differentiation by disrupting translation of target mRNAs. Data presented here indicate that expression of miR203, a miRNA that targets ΔNp63α and ΔNp63β is activated during luminal epithelial differentiation and that this pattern is observed in the murine mammary hierarchy. In addition, we present evidence that the transcription factor Zeb1 represses miR203 expression, thus enhancing ΔNp63α protein levels. Furthermore, ectopic miR203 suppresses ΔNp63α expression, proliferation and colony formation. The anti-clonogenic effects mediated by miR203 require suppression of ΔNp63α. In addition, ectopic miR203 promotes mesenchymal-to-epithelial transition and disrupts activities associated with epithelial stem cells. These studies support a model in which induction of miR203 mediates forfeiture of self-renewing capacity via suppression of ΔNp63α and may also have anti-tumorigenic activity through its reduction of EMT and cancer stem cell populations
Clinical pharmacokinetics and pharmacodynamics of cerliponase alfa, enzyme replacement therapy for CLN2 disease by intracerebroventricular administration
Cerliponase alfa is recombinant human TPP1 delivered by intracerebroventricular (ICV) infusion for CLN2, a pediatric neurodegenerative disease caused by deficiency in lysosomal enzyme TPP1. We report the PK and PD of cerliponase alfa, the first ICV enzyme replacement therapy, characterized in a Phase 1/2 study. Escalating doses (30-300 mg every two weeks, Q2W) followed by 300 mg Q2W for ≥48 weeks were administered in 24 patients aged ≥3 years. Concentrations peaked in CSF at the end of ~4-hour ICV infusion and 8 hours thereafter in plasma. Plasma exposure was 300-1000 fold lower than in CSF, with no correlation in the magnitude of Cmax or AUC between body sites. There was no apparent accumulation in CSF or plasma exposure with Q2W dosing. Inter- and intra-patient variability of AUC, respectively, were 31-49% and 24% in CSF versus 59-103% and 80% in plasma. PK variability was not explained by baseline demographics, as gender, age, weight, and CLN2 disease severity score did not appear to impact CSF or plasma PK. No apparent correlation was noted between CSF or plasma PK and incidence of adverse events (pyrexia, hypersensitivity, seizure, and epilepsy) or presence of antidrug antibodies in CSF and serum. There was no relationship between magnitude of CSF exposure and efficacy (change in CLN2 score from baseline), indicating maximum benefit was obtained across the range of exposures with 300 mg Q2W. Data from this small trial of ultra-rare disease were leveraged to adequately profile cerliponase alfa and support 300 mg ICV Q2W for CLN2 treatment
Deep-Tissue Anatomical Imaging of Mice Using Carbon Nanotube Fluorophores in the Second Near Infrared Window
Fluorescent imaging in the second near infrared window (NIR II, 1-1.4 {\mu}m)
holds much promise due to minimal autofluorescence and tissue scattering. Here,
using well functionalized biocompatible single-walled carbon nanotubes (SWNTs)
as NIR II fluorescent imaging agents, we performed high frame rate video
imaging of mice during intravenous injection of SWNTs and investigated the path
of SWNTs through the mouse anatomy. We observed in real-time SWNT circulation
through the lungs and kidneys several seconds post-injection, and spleen and
liver at slightly later time points. Dynamic contrast enhanced imaging through
principal component analysis (PCA) was performed and found to greatly increase
the anatomical resolution of organs as a function of time post-injection.
Importantly, PCA was able to discriminate organs such as the pancreas which
could not be resolved from real-time raw images. Tissue phantom studies were
performed to compare imaging in the NIR II region to the traditional NIR I
biological transparency window (700- 900 nm). Examination of the feature sizes
of a common NIR I dye (indocyanine green, ICG) showed a more rapid loss of
feature contrast and integrity with increasing feature depth as compared to
SWNTs in the NIR II region. The effects of increased scattering in the NIR I
versus NIR II region were confirmed by Monte Carlo simulation. In vivo
fluorescence imaging in the NIR II region combined with PCA analysis may
represent a powerful approach to high resolution optical imaging through deep
tissues, useful for a wide range of applications from biomedical research to
disease diagnostics.Comment: Proceedings of the National Academy of Sciences (PNAS), 201
Safety and efficacy of cerliponase alfa in children with neuronal ceroid lipofuscinosis type 2 (CLN2 disease): an open-label extension study
Background: Cerliponase alfa is a recombinant human tripeptidyl peptidase 1 (TPP1) enzyme replacement therapy for the treatment of neuronal ceroid lipofuscinosis type 2 (CLN2 disease), which is caused by mutations in the TPP1 gene. We aimed to determine the long-term safety and efficacy of intracerebroventricular cerliponase alfa in children with CLN2 disease. Methods: This analysis includes cumulative data from a primary 48-week, single-arm, open-label, multicentre, dose-escalation study (NCT01907087) and the 240-week open-label extension with 6-month safety follow-up, conducted at five hospitals in Germany, Italy, the UK, and the USA. Children aged 3–16 years with CLN2 disease confirmed by genetic analysis and enzyme testing were eligible for inclusion. Treatment was intracerebroventricular infusion of 300 mg cerliponase alfa every 2 weeks. Historical controls with untreated CLN2 disease in the DEM-CHILD database were used as a comparator group. The primary efficacy outcome was time to an unreversed 2-point decline or score of 0 in the combined motor and language domains of the CLN2 Clinical Rating Scale. This extension study is registered with ClinicalTrials.gov, NCT02485899, and is complete. Findings: Between Sept 13, 2013, and Dec 22, 2014, 24 participants were enrolled in the primary study (15 female and 9 male). Of those, 23 participants were enrolled in the extension study, conducted between Feb 2, 2015, and Dec 10, 2020, and received 300 mg cerliponase alfa for a mean of 272·1 (range 162·1–300·1) weeks. 17 participants completed the extension and six discontinued prematurely. Treated patients were significantly less likely than historical untreated controls to have an unreversed 2-point decline or score of 0 in the combined motor and language domains (hazard ratio 0·14, 95% CI 0·06 to 0·33; p<0·0001). All participants experienced at least one adverse event and 21 (88%) experienced a serious adverse event; nine participants experienced intracerebroventricular device-related infections, with nine events in six participants resulting in device replacement. There were no study discontinuations because of an adverse event and no deaths. Interpretation: Cerliponase alfa over a mean treatment period of more than 5 years was seen to confer a clinically meaningful slowing of decline of motor and language function in children with CLN2 disease. Although our study does not have a contemporaneous control group, the results provide crucial insights into the effects of long-term treatment. Funding: BioMarin Pharmaceutical
Concept for Predicting Vibrations in Machine Tools Using Machine Learning
Vibrations have a significant influence on quality and costs in metal
cutting processes. Existing methods for predicting vibrations in machine tools enable an informed choice of process settings, however they rely on costly equipment and specialised staff. Therefore, this contribution proposes to reduce the modelling effort required by using machine learning based on data gathered during production. The approach relies on two sub-models, representing the machine structure and machining process respectively. A method is proposed for initialising and updating the models in production
ERR2 and ERR3 promote the development of gamma motor neuron functional properties required for proprioceptive movement control
The ability of terrestrial vertebrates to effectively move on land is integrally linked to the diversification of motor neurons into types that generate muscle force (alpha motor neurons) and types that modulate muscle proprioception, a task that in mammals is chiefly mediated by gamma motor neurons. The diversification of motor neurons into alpha and gamma types and their respective contributions to movement control have been firmly established in the past 7 decades, while recent studies identified gene expression signatures linked to both motor neuron types. However, the mechanisms that promote the specification of gamma motor neurons and/or their unique properties remained unaddressed. Here, we found that upon selective loss of the orphan nuclear receptors ERR2 and ERR3 (also known as ERR beta, ERR gamma or NR3B2, NR3B3, respectively) in motor neurons in mice, morphologically distinguishable gamma motor neurons are generated but do not acquire characteristic functional properties necessary for regulating muscle proprioception, thus disrupting gait and precision movements. Complementary gain-of-function experiments in chick suggest that ERR2 and ERR3 could operate via transcriptional activation of neural activity modulators to promote a gamma motor neuron biophysical signature of low firing thresholds and high firing rates. Our work identifies a mechanism specifying gamma motor neuron functional properties essential for the regulation of proprioceptive movement control
Detection, Mapping, and Quantification of Single Walled Carbon Nanotubes in Histological Specimens with Photoacoustic Microscopy
Contains fulltext :
110845.pdf (publisher's version ) (Open Access)AIMS: In the present study, the efficacy of multi-scale photoacoustic microscopy (PAM) was investigated to detect, map, and quantify trace amounts [nanograms (ng) to micrograms (microg)] of SWCNTs in a variety of histological tissue specimens consisting of cancer and benign tissue biopsies (histological specimens from implanted tissue engineering scaffolds). MATERIALS AND METHODS: Optical-resolution (OR) and acoustic-resolution (AR)--Photoacoustic microscopy (PAM) was employed to detect, map and quantify the SWCNTs in a variety of tissue histological specimens and compared with other optical techniques (bright-field optical microscopy, Raman microscopy, near infrared (NIR) fluorescence microscopy). RESULTS: Both optical-resolution and acoustic-resolution PAM, allow the detection and quantification of SWCNTs in histological specimens with scalable spatial resolution and depth penetration. The noise-equivalent detection sensitivity to SWCNTs in the specimens was calculated to be as low as approximately 7 pg. Image processing analysis further allowed the mapping, distribution, and quantification of the SWCNTs in the histological sections. CONCLUSIONS: The results demonstrate the potential of PAM as a promising imaging technique to detect, map, and quantify SWCNTs in histological specimens, and could complement the capabilities of current optical and electron microscopy techniques in the analysis of histological specimens containing SWCNTs
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Accelerometry: a practical tool for understanding the role of energy in agriculture-nutrition linkages
Research on nutrition in low and middle-income countries (LMICs) has mainly focused on how policy and project interventions can bring about changes in diets, while changes in physical activity has been largely overlooked. Productivity-enhancing activities can impact the calorie deficits of the undernourished via their effects on energy intakes and energy expenditure. Rural transformation also has an effect on lifestyles of rural people. Changes in diets and physical activity patterns has a profound effect on livelihoods. The energy expenditure dimension has previously not been incorporated in the analysis of agriculture-nutrition linkages and livelihood analysis. Most studies capturing energy expenditure in rural households in LMICs have use methods that require a controlled setting. These can be quite expensive and are often very practical for population-level studies. Accelerometry has advanced in recent years, providing a new opportunity to collect more accurate population-level data on energy expenditure
PET Imaging of Soluble Yttrium-86-Labeled Carbon Nanotubes in Mice
The potential medical applications of nanomaterials are shaping the landscape of the nanobiotechnology field and driving it forward. A key factor in determining the suitability of these nanomaterials must be how they interface with biological systems. Single walled carbon nanotubes (CNT) are being investigated as platforms for the delivery of biological, radiological, and chemical payloads to target tissues. CNT are mechanically robust graphene cylinders comprised of sp(2)-bonded carbon atoms and possessing highly regular structures with defined periodicity. CNT exhibit unique mechanochemical properties that can be exploited for the development of novel drug delivery platforms. In order to evaluate the potential usefulness of this CNT scaffold, we undertook an imaging study to determine the tissue biodistribution and pharmacokinetics of prototypical DOTA-functionalized CNT labeled with yttrium-86 and indium-111 ((86)Y-CNT and (111)In-CNT, respectively) in a mouse model.The (86)Y-CNT construct was synthesized from amine-functionalized, water-soluble CNT by covalently attaching multiple copies of DOTA chelates and then radiolabeling with the positron-emitting metal-ion, yttrium-86. A gamma-emitting (111)In-CNT construct was similarly prepared and purified. The constructs were characterized spectroscopically, microscopically, and chromatographically. The whole-body distribution and clearance of yttrium-86 was characterized at 3 and 24 hours post-injection using positron emission tomography (PET). The yttrium-86 cleared the blood within 3 hours and distributed predominantly to the kidneys, liver, spleen and bone. Although the activity that accumulated in the kidney cleared with time, the whole-body clearance was slow. Differential uptake in these target tissues was observed following intravenous or intraperitoneal injection.The whole-body PET images indicated that the major sites of accumulation of activity resulting from the administration of (86)Y-CNT were the kidney, liver, spleen, and to a much less extent the bone. Blood clearance was rapid and could be beneficial in the use of short-lived radionuclides in diagnostic applications
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