Characterising the shape, size, and orientation of cloud‐feeding coherent boundary‐layer structures

Two techniques are presented for characterisation of cloud-feeding coherent boundary-layer structures through analysis of large-eddy simulations of shallow cumulus clouds, contrasting conditions with and without ambient shear. The first technique is a generalisation of the two-point correlation function, where the correlation length-scale as well as the orientation can be extracted. The second technique identifies individual coherent structures and decomposes their vertical transport by the shape, size, and orientation of these objects. The bulk-correlation technique is shown to capture the elongation and orientation of coherence by ambient wind, but is unable to characterise individual coherent structures. Using the object-based approach, it is found that the individual structures dominating the vertical flux are plume-like in character (extending from the surface into cloud) rather than thermal-like, show small width/thickness asymmetry, and rise near-vertically in the absence of ambient wind. The planar stretching and tilting of boundary-layer structures caused by the introduction of ambient shear is also quantified, demonstrating the general applicability of the techniques for future study of other boundary-layer patterns

Flow-Alignment of Extracellular Vesicles: Structure and Orientation of Membrane Associated Biomacromolecules Studied with Polarized Light

Extracellular vesicles (EVs) are currently in the scientific focus having a great potential to revolutionize the diagnosis and therapy of various diseases. However, numerous aspects of these species are still poorly understood, thus additional insight to molecular level properties, membrane-protein interactions, or membrane rigidity is still needed. We here demonstrate using red blood cell derived EVs (REVs) that polarized light spectroscopy techniques, linear and circular dichroism, can provide molecular level structural information on these systems. Flow-linear dichroism (flow-LD) measurements show that EVs can be oriented by shear force, and indicate that hemoglobin molecules are associated to the lipid bilayer in freshly released REVs. During storage this interaction ceases coupled to major protein conformational changes relative to the initial state. Further on, the degree of orientation gives insight to vesicle rigidity, which decreases in time parallel to changes in protein conformation. In overall, we propose that both LD and circular dichroism (CD) spectra provide simple, rapid, yet efficient ways to track changes in membrane-protein interactions of EV components at the molecular level which may also give insight to processes occurring during vesiculation

Circulating platelet-derived and placenta-derived microparticles expose Flt-1 in preeclampsia.

BACKGROUND: Flt-1 is secreted by various cells and elevated concentrations are present in preeclampsia affecting vascular function. Microparticles from these cells may expose Flt-1. We evaluated whether Flt-1 is microparticle-associated in preeclampsia, and established the origin of Flt-1-exposing microparticles. METHODS: The concentration of Flt-1 was measured in samples from preeclamptic patients, pregnant and nonpregnant women by enzyme-linked immunosorbent assay. Microparticles were analyzed by flow cytometry. Western blot determined the different forms of Flt-1. RESULTS: Noncell bound Flt-1 was elevated in preeclampsia compared to controls. A fraction (5%) was associated with microparticles in preeclampsia. Flt-1-exposing microparticles were increased in preeclampsia compared to normotensive pregnancy (p = 0.02). Full-length Flt-1, was identified in microparticles of platelet and placental origin. CONCLUSION: Full-length Flt-1 is associated with platelet and placenta-derived microparticles. Possibly, the presentation of Flt-1 on the membrane of a microparticle might alter its function, particularly if it acts in synergism with other exposed vasoactive molecules

Comparative analysis of length of stay, hospitalization costs, opioid use, and discharge status among spine surgery patients with postoperative pain management including intravenous versus oral acetaminophen

<p><b>Background:</b> Recovery from spine surgery is oriented toward restoring functional health outcomes while reducing resource use. Optimal pain management is a key to reaching these objectives. We compared outcomes of spine surgery patients who received standard pain management including intravenous (IV) acetaminophen (APAP) vs. oral APAP.</p> <p><b>Methods:</b> We performed a retrospective analysis of the Premier database (January 2012 to September 2015) comparing spine surgery patients who received pain management with IV APAP to those who received oral APAP, with no exclusions based on additional pain management. We performed multivariable logistic regression for the discharge and all cause 30-day readmission to the same hospital outcomes and instrumental variable regressions using the quarterly rate of IV APAP use for all hospitalizations by hospital as the instrument in two-stage least squares regressions for length of stay (LOS), hospitalization costs, and average daily morphine equivalent dose (MED) outcomes. Models adjusted for age, gender, race, admission type, 3M All Patient Refined Diagnosis Related Group severity of illness and risk of mortality, hospital size, and indicators for whether the hospital was an academic center and whether it was urban or rural.</p> <p><b>Results:</b> We identified 112,586 spine surgery patients with 51,835 (46%) having received IV APAP. Subjects averaged 57 and 59 years of age respectively in the IV APAP and oral APAP cohorts and were predominantly non-Hispanic Caucasians and female. In our adjusted models, IV APAP was associated with 0.68 days shorter LOS (95% CI: −0.76 to −0.59, <i>p</i> < .0001), $1175 lower hospitalization costs (95$1611 to −$739, <i>p</i> < .0001), 13 mg lower average daily MED (95% CI: −14 mg to −12 mg, <i>p</i> < .0001), 34% lower risk of discharge to a skilled nursing facility (95% CI: 0.63 to 0.69, <i>p</i> < .0001), and 13% less risk of 30-day readmission (95% CI: 0.73 to 1.03).</p> <p><b>Conclusions:</b> Compared to oral APAP, managing post-spine-surgery pain with IV APAP is associated with less resource use, lower costs, lower doses of opioids, and improved discharge status.</p

Analysis of predictors of opioid-free analgesia for management of acute post-surgical pain in the United States

<p><b>Objectives:</b> Utilization of opioid-free analgesia (OFA) for post-surgical pain is a growing trend to counter the risks of opioid abuse and opioid-related adverse drug events (ORADEs). However, utilization patterns of OFA have not been examined. In this study, we investigated the utilization patterns and predictors of OFA in a surgical population in the United States.</p> <p><b>Methods:</b> Analysis of the Cerner Health Facts database (January 2011 to December 2015) was conducted to describe hospital and patient characteristics associated with OFA. Baseline characteristics, such as age, gender, race, discharge status, year of admission and chronic comorbidities at index admission were collected. Hospital characteristics and payer type at index admission were collected as reported in the electronic health record database. Descriptive statistics and logistic regression were used to identify statistically significant predictors of OFA on patient and institutional levels.</p> <p><b>Results:</b> The study identified 10,219 patients, from 187 hospitals, who received post-surgical OFA and 255,196 patients who received post-surgical opioids. OFA rates varied considerably by hospital. Patients more likely to receive OFA were older (OR = 1.06, 95% CI [1.03, 1.10]; <i>p</i> < .001), or had neurological disorders (OR = 1.24, 95% CI [1.10, 1.39]; <i>p</i> < .001), diabetes (OR = 1.20, 95% CI [1.08, 1.33]; <i>p</i> = .001) or psychosis (OR = 1.18, 95% CI [1.01, 1.37]; <i>p</i> = .030). Patients with obesity and depression were less likely to receive OFA (OR = 0.80, 95% CI [0.67, 0.95]; <i>p</i> = .010 OR = 0.85, 95% CI [0.73, 0.98]; <i>p</i> = .030, respectively).</p> <p><b>Conclusions:</b> Use of post-surgical OFA was limited overall and was not favored in some patient groups prone to ORADEs, indicating missed opportunities to reduce opioid use and ORADE incidence. A substantial proportion of OFA patients was contributed by a few hospitals with especially high rates of OFA, suggesting that hospital policies, institutional structure and cross-functional departmental commitment to reducing opioid use may play a large role in the implementation of OFA.</p