152 research outputs found
Access to urban parks: Comparing spatial accessibility measures using three GIS-based approaches
Urban parks are essential components of urban ecosystems, providing recreation and relaxation places to residents. Measuring the spatial accessibility to urban parks serves as an initial step in urban planning and developing urban development strategies to improve social and environmental justice. This study aims to evaluate measures of spatial accessibility to urban parks by comparing three geographic information systems (GIS)-based approaches, accounting for network complexity, transport modes, distance thresholds, and destination choices. Taking Ipswich City (Australia) and Enschede (the Netherlands) as two testbeds, we examine the spatial patterns of a total of 21 accessibility measures in the two cities and conduct a correlation and principal component analysis to unravel the interrelationship between these measures. The results suggest that among all measures under the three approaches, the selection of distance thresholds and transport modes matter more to accessibility measures than the destination choices. Furthermore, when distance threshold and transport mode are held constant, the network-based and entrance-based methods provide more realistic accessibility measures than other methods. We also discuss the generality of the entrance-based method we propose and suggest ways to choose the most appropriate accessibility measure for use in different contexts
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The Risk of Adverse Events Associated With Atropine Administration During Dobutamine Stress Echocardiography in Cardiac Transplant Patients: A 28-Year Single-Center Experience
Background
Although dobutamine stress echocardiography (DSE) is performed in heart transplant patients, the safety profile of atropine administration in DSE in this setting is unclear.
Methods and Results
We identified heart transplant patients who received atropine during DSE from January 1984 to August 2011 at our institution and compared them with a propensity-scored matched control group of heart transplant patients who underwent DSE without atropine. Adverse events were defined as significant arrhythmias (sinus arrest, Mobitz type II heart block, complete heart block, ventricular tachycardia, or ventricular fibrillation), hypotension requiring hospitalization, syncope or presyncope, myocardial infarction, and death. Forty-five heart transplant patients (median age 62 years, 82% male) received 0.2–1 mg atropine during DSE. Of these, 1 patient (2.2%) developed temporary complete heart block. No adverse events were identified in the control group of 154 patients who received dobutamine without atropine.
Conclusions
Our findings suggest that complete heart block can occur infrequently with the administration of atropine in heart transplant patients undergoing DSE. Therefore, patients should be appropriately monitored for these adverse events during and after DSE
Effect of change in systolic blood pressure between clinic visits on estimated 10-year cardiovascular disease risk
Background
Systolic blood pressure (SBP) often varies between clinic visits within individuals, which can affect estimation of cardiovascular disease (CVD) risk.
Methods and Results
We analyzed data from participants with two clinic visits separated by a median of 17 days in the Third National Health and Nutrition Examination Survey (n = 808). Ten-year CVD risk was calculated with SBP obtained at each visit using the Pooled Cohort Equations. The mean age of participants was 46.1 years, and 47.3% were male. The median SBP difference between the two visits was −1 mm Hg (1st to 99th percentiles: −23 to 32 mm Hg). The median estimated 10-year CVD risk was 2.5% and 2.4% at the first and second visit, respectively (1st to 99th percentiles −5.2% to +7.1%). Meaningful risk reclassification (ie, across the guideline recommended 7.5% threshold for statin initiation) occurred in 12 (11.3%) of 106 participants whose estimated CVD risk was between 5% and 10%, but only in two (0.3%) of 702 participants who had a 10-year estimated CVD risk of 10%.
Conclusions
SBP variability can affect CVD risk estimation, and can influence statin eligibility for individuals with an estimated 10-year CVD risk between 5% and 10%
A global portrait of expressed mental health signals towards COVID-19 in social media space
Globally, the COVID-19 pandemic has induced a mental health crisis. Social media data offer a unique oppor-
tunity to track the mental health signals of a given population and quantify their negativity towards COVID-19.
To date, however, we know little about how negative sentiments differ across countries and how these relate to
the shifting policy landscape experienced through the pandemic. Using 2.1 billion individual-level geotagged
tweets posted between 1 February 2020 and 31 March 2021, we track, monitor and map the shifts in negativity
across 217 countries and unpack its relationship with COVID-19 policies. Findings reveal that there are important
geographic, demographic, and socioeconomic disparities of negativity across continents, different levels of a
nation’s income, population density, and the level of COVID-19 infection. Countries with more stringent policies
were associated with lower levels of negativity, a relationship that weakened in later phases of the pandemic.
This study provides the first global and multilingual evaluation of the public’s real-time mental health signals to
COVID-19 at a large spatial and temporal scale. We offer an empirical framework to monitor mental health
signals globally, helping international authorizations, including the United Nations and World Health Organi-
zation, to design smart country-specific mental health initiatives in response to the ongoing pandemic and future
public emergencies
Anti-Lung-Cancer Activity and Liposome-Based Delivery Systems of β
In the past decade, β-elemene played an important role in enhancing the effects of many anticancer drugs and was widely used in the treatment of different kinds of malignancies and in reducing the side effects of chemotherapy. Further study showed that it is also a promising anti-lung cancer drug. However, the clinical application of β-elemene was limited by its hydrophobic property, poor stability, and low bioavailability. With the development of new excipients and novel technologies, plenty of novel formulations of β-elemene have improved dramatically, which provide a positive perspective in terms of clinical application for β-elemene. Liposome as a drug delivery system shows great advantages over traditional formulations for β-elemene. In this paper, we summarize the advanced progress being made in anti-lung cancer activity and the new liposomes delivery systems of β-elemene. This advancement is expected to improve the level of pharmacy research and provide a stronger scientific foundation for further study on β-elemene
Defect Analysis in Microgroove Machining of Nickel-Phosphide Plating by Small Cross-Angle Microgrooving
Crystalline nickel-phosphide (c-Ni-P) plating is a newly developed mold material for precision glass molding (PGM) to fabricate microgrooves. In the ultraprecision cutting process of the c-Ni-P plating material, the neighboring microgrooves are required to adjoin with each other to ensure acute microgroove ridges and miniaturize the microgroove size. Generally, defects of burrs and fracture pits can easily occur on the ridges when the plating layer is grooved. Burrs appear when tears dominate in material removal with a large adjacent amount. With the change of the adjacent amount, the removed material is sheared out from the workpiece, and when the cutting depth of the groove ridge is over the brittle-ductile transition thickness, fracture pits arise. To restrict these defects, a small cross-angle microgrooving method is proposed to test the critical adjacent amount range efficiently. It is found that an acute ridge of the microgroove is formed with a small enough adjacent amount; when this amount is in the range of 570 nm~720 nm in the microgroove machining process, fracture pits begin to arise on the gradient edge. High-quality microgrooves can be obtained based on this methodology
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Activin A and BMP4 Signaling Expands Potency of Mouse Embryonic Stem Cells in Serum-Free Media.
Inhibitors of Mek1/2 and Gsk3β, known as 2i, and, together with leukemia inhibitory factor, enhance the derivation of embryonic stem cells (ESCs) and promote ground-state pluripotency (2i/L-ESCs). However, recent reports show that prolonged Mek1/2 suppression impairs developmental potential of ESCs, and is rescued by serum (S/L-ESCs). Here, we show that culturing ESCs in Activin A and BMP4, and in the absence of MEK1/2 inhibitor (ABC/L medium), establishes advanced stem cells derived from ESCs (esASCs). We demonstrate that esASCs contributed to germline lineages, full-term chimeras and generated esASC-derived mice by tetraploid complementation. We show that, in contrast to 2i/L-ESCs, esASCs display distinct molecular signatures and a stable hypermethylated epigenome, which is reversible and similar to serum-cultured ESCs. Importantly, we also derived novel ASCs (blASCs) from blastocysts in ABC/L medium. Our results provide insights into the derivation of novel ESCs with DNA hypermethylation from blastocysts in chemically defined medium
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