Order-disorder transition of a rigid cage cation embedded in a cubic perovskite.

The structure and properties of organic-inorganic hybrid perovskites are impacted by the order-disorder transition, whose driving forces from the organic cation and the inorganic framework cannot easily be disentangled. Herein, we report the design, synthesis and properties of a cage-in-framework perovskite AthMn(N3)3, where Ath+ is an organic cation 4-azatricyclo[2.2.1.02,6]heptanium. Ath+ features a rigid and spheroidal profile, such that its molecular reorientation does not alter the cubic lattice symmetry of the Mn(N3)3- host framework. This order-disorder transition is well characterized by NMR, crystallography, and calorimetry, and associated with the realignment of Ath+ dipole from antiferroelectric to paraelectric. As a result, an abrupt rise in the dielectric constant was observed during the transition. Our work introduces a family of perovskite structures and provides direct insights to the order-disorder transition of hybrid materials.

Estimate of mortality reduction with implementation of advanced automatic collision notification.

OBJECTIVE: Advanced Automatic Collision Notification (AACN) is a system on a motor vehicle that notifies a public safety answering point (PSAP), either directly or through a third party, that the vehicle has had a crash. AACN systems enable earlier notification of a motor vehicle crash and provide an injury prediction that can help dispatchers and first responders make better decisions about how and where to transport the patient, thus getting the patient to definitive care sooner. The purposes of the current research are to identify the target population that could benefit from AACN, and to develop a reasonable estimate range of potential lives saved with implementation of AACN within the vehicle fleet. METHODS: Data from the Fatality Analysis Reporting System (FARS) years 2009-2015 and National Automotive Sampling System-Crashworthiness Data System (NASS-CDS) years 2000-2015 were obtained. FARS data were used to determine absolute estimates of the target population who may receive benefit from AACN. These estimates accounted for a number of factors, such as whether a fatal occupant had nearby access to a trauma center and also was correctly identified by the injury severity prediction algorithm as having a "high probability of severe injury." NASS-CDS data were used to provide relative comparisons among subsets of the population. Specifically, relative survival rate ratios between occupants treated at trauma centers versus at non-trauma centers were determined using the nonparametric Kaplan-Meier estimator. Finally, the fatality reduction rate associated with trauma center care was combined with the previously published fatality reduction rate for faster notification time to develop a range for possible lives saved. RESULTS: Two relevant target populations were identified. A larger subset of 6893 fatalities can benefit only from earlier notification associated with AACN. A smaller subgroup of between 1495 and 2330 fatalities can benefit from both earlier notification and change in treatment destination (i.e., non-trauma center to trauma center). A Kaplan-Meier life curve and a multiple proportional hazard model were used to predict the benefits associated with transport to a trauma center. The resulting range for potential lives saved annually was 360 to 721. CONCLUSIONS: This analysis provides the estimates of lives that could potentially be saved with full implementation of AACN and universal cell coverage availability. This represents a fatality reduction of approximately 1.6% to 3.3% per year, and more than double the lives saved by earlier notification alone. In conclusion, AACN is a postcrash technology with a promising potential for safety benefit. AACN is therefore a key component of integrated safety systems that aim to protect occupants across the entire crash spectrum.

The effect of earlier or automatic collision notification on traffic mortality by survival analysis.

OBJECTIVE: This article explores the effects of earlier emergency medical services (EMS) or automatic collision notification (ACN) and EMS arrival on passenger/driver survivability within the short time frame following traffic crashes. METHODS: Survival analysis techniques are used extensively in this study, because traffic crash and EMS data are closely associated with time. The Kaplan-Meier estimator and life curves are applied to compare the survival rates between 2 or more conditions (e.g., earlier verus late EMS notification); The Weibull model with 3 parameters is used to predict mortality over time; furthermore, the Cox proportional hazard model explores multiple risk factors related to traffic mortality. RESULTS: Based on Fatality Analysis Reporting System (FARS) data from 2005 to 2009, Kaplan-Meier life curves clearly showed the benefits associated with earlier notifications (approximately 1.84% fatality reduction within a time frame of 6 h after a crash) and earlier arrivals, and the Weibull model with 3 parameters reasonably predicted the fatality trends. The relative risks (RRs) associated with collision notification, arrival, location, and age were obtained from a multiple Cox regression model, and the relatively higher fatality hazard (2.4% higher) associated with the later notification of more than 1 min was studied in detail. CONCLUSIONS: This article obtains the driver/passenger survival probability differences over time under different conditions of collision notifications, EMS arrivals, and crash locations; furthermore, this analysis provides an estimation of the lives that could potentially be saved (approximately 154 to 290 per year) due to earlier ACN.

Structure revision and cytotoxic activity of marinamide and its methyl ester, novel alkaloids produced by co-cultures of two marine-derived mangrove endophytic fungi.

Marinamide (1) and its methyl ester (2) have been previously reported as pyrrolyl 1-isoquinolone alkaloids, which were produced by co-cultures of two marine-derived mangrove endophytic fungi from the South China Sea coast. Recrystallisation of methyl marinamide (2) from pyridine forms the known pesticide, quinolactacide (3). Treatment of 3 with methyl iodide to afford N-methyl quinolactacide (4) was identified by X-ray crystallography. Thus, the structures of 1 and 2 were revised from the previously reported pyrrolyl 1-isoquinolone structures to pyrrolyl 4-quinolone analogues. In the MTT assays, both 1 and 2 exhibited potent cytotoxic activity against HepG2, 95-D, MGC832 and HeLa tumour cell lines.

A numerical investigation of blood damage in the hinge area of aortic bileaflet mechanical heart valves during the leakage phase.

Previous experimental and numerical blood studies have shown that high shear stress levels, long exposure times to these shear stresses, and flow recirculation promote thromboembolism. Artificial heart valves, in particular bileaflet mechanical heart valves (BMHVs), are prone to developing thromboembolic complications. These complications often form at the hinge regions of BMHVs and the associated geometry has been shown to affect the local flow dynamics and the associated thrombus formation. However, to date no study has focused on simulating the motion of realistically modeled blood elements within the hinge region to numerically estimate the hinge-related blood damage. Consequently, this study aims at (a) simulating the motion of realistically modeled platelets during the leakage (mid-diastole) phase in different BMHV hinge designs placed in the aortic position and (b) quantitatively comparing the blood damage associated with different designs. Three designs are investigated to assess the effects of hinge geometry and dimensions: a 23 mm St. Jude Medical Regent™ valve hinge with two different gap distances between the leaflet ear and hinge recess; and a 23 mm CarboMedics (CM) aortic valve hinge. The recently developed lattice-Boltzmann method with external boundary force method is used to simulate the hinge flow and capture the dynamics and surface shear stresses of individual platelets. A blood damage index (BDI) value is then estimated based on a linear shear stress-exposure time BDI model. The velocity boundary conditions are obtained from previous 3D large-scale simulations of the hinge flow fields. The trajectories of the blood elements in the hinge region are found to be qualitatively similar for all three hinges, but the shear stresses experienced by individual platelets are higher for the CM hinge design, leading to a higher BDI. The results of this study are also shown to be in good agreement with previous studies, thus validating the numerical method for future research in BMHV flows. This study provides a general numerical tool to optimize the hinge design based on both hemodynamic and thromboembolic performance.

Biosynthesis, characterization and biological evalutation of Fe(III) and Cu(II) complexes of neoaspergillic acid, a hydroxamate siderophore produced by co-cultures of two marine-derived mangrove epiphytic fungi.

A hydroxamate siderophore, neoaspergillic acid (1), and a red pigment, ferrineoaspergillin (2) which is an Fe(III) complex of 1, were produced by co-cultures of two epiphytic fungi from a rotten fruit of the mangrove Avicennia marina from the South China Sea, and a new Cu(II) complex of 1, designated as cuprineoaspergillin (3), was also prepared by treatment of 1 with cupric acetate. All the compounds (1-3) were characterized by physical and chemical techniques, including 1H NMR, ESIMS, and photoelectron energy spectra. In the bioassays, compounds 1-3 showed significant inhibitory activities against selected Gram-positive and Gram-negative bacteria, and compound 1 also exhibited moderate inhibitory activities against human cancer cell lines SPC-A-1, BEL-7402, SGC-7901 and K562.

Numerical investigation of the effects of channel geometry on platelet activation and blood damage.

Thromboembolic complications in Bileaflet mechanical heart valves (BMHVs) are believed to be due to the combination of high shear stresses and large recirculation regions. Relating blood damage to design geometry is therefore essential to ultimately optimize the design of BMHVs. The aim of this research is to quantitatively study the effect of 3D channel geometry on shear-induced platelet activation and aggregation, and to choose an appropriate blood damage index (BDI) model for future numerical simulations. The simulations in this study use a recently developed lattice-Boltzmann with external boundary force (LBM-EBF) method [Wu, J., and C. K. Aidun. Int. J. Numer. Method Fluids 62(7):765-783, 2010; Wu, J., and C. K. Aidun. Int. J. Multiphase flow 36:202-209, 2010]. The channel geometries and flow conditions are re-constructed from recent experiments by Fallon [The Development of a Novel in vitro Flow System to Evaluate Platelet Activation and Procoagulant Potential Induced by Bileaflet Mechanical Heart Valve Leakage Jets in School of Chemical and Biomolecular Engineering. Atlanta: Georgia Institute of Technology] and Fallon et al. [Ann. Biomed. Eng. 36(1):1]. The fluid flow is computed on a fixed regular 'lattice' using the LBM, and each platelet is mapped onto a Lagrangian frame moving continuously throughout the fluid domain. The two-way fluid-solid interactions are determined by the EBF method by enforcing a no-slip condition on the platelet surface. The motion and orientation of the platelet are obtained from Newtonian dynamics equations. The numerical results show that sharp corners or sudden shape transitions will increase blood damage. Fallon's experimental results were used as a basis for choosing the appropriate BDI model for use in future computational simulations of flow through BMHVs.

Utility of the radioiodine whole-body retention at 48 hours for modifying empiric activity of 131-iodine for the treatment of metastatic well-differentiated thyroid carcinoma.

BACKGROUND: Dosimetry has been used to help identify when empiric dosages of 131-I treatment for suspected metastatic well-differentiated thyroid carcinoma (WDTC) may be increased or should be decreased, but dosimetry is complex, and easier approaches would be useful. The three objectives of this study were to assess the utility of the percent whole-body retention of 131-I at 48 hours (%WBR(48hr)) in identifying patients with WDTC in whom the therapeutic empiric prescribed activity of 131-I might be increased/decreased, to evaluate the thresholds proposed by Sisson et al. in 2003 for increasing or decreasing activity, and to determine the relationship between %WBR(48hr) and maximum tolerated activity (MTA). METHOD: A retrospective review was conducted of patients who had WDTC, total thyroidectomy, suspected metastatic disease, thyroid hormone withdrawal, and 131-I dosimetry. The %WBR(48hr) was determined based on the Benua-Leeper dosimetry protocol, and the four thresholds and recommendations of Sisson et al., 2003 for the use of %WBR(48hr) were evaluated relative to an empiric activity (EA) of 7.4 GBq of 131-I. A biexponential equation was determined from the %WBR(48hr) data. RESULTS: Of 142 patients, 47 patients had a %WBR(48hr) of <9%, and all could have received more than the EA of 7.4 GBq with an average of 21.0 GBq (incremental range of 6.8-23.2 GBq). Ten patients had a %WBR(48hr) < or = 5%, and all could have had their EA of 7.4 GBq safely increased by at least 250%. Conversely, if the %WBR(48hr) was >24.8%, then 7 of 14 of these patients would have exceeded the MTA by 0.37-3.18 GBq with an EA of 7.4 GBq. Finally, for patients with a %WBR(48hr) > 40%, five of six patients would have exceeded the MTA by 0.85-3.18 GBq. A biexponential regression equation is presented. CONCLUSION: We conclude that, with respect to the treatment of metastatic epithelial cell thyroid cancer, the %WBR(48hr) of 131-I helps identify those patients in whom the empiric therapeutic prescribed activity of 131-I may be increased or should be decreased so as not to exceed the MTA and that Sisson et al.'s thresholds published in 2003 are applicable. We favor a biexponential regression model using the %WBR(48hr) and a lower limit threshold as a potentially useful method for determining how much an empiric therapeutic prescribed activity of 131-I can be increased or decreased.

Laser Doppler imaging of cutaneous blood flow through transparent face masks: a necessary preamble to computer-controlled rapid prototyping fabrication with submillimeter precision.

A paradigm shift in management of postburn facial scarring is lurking "just beneath the waves" with the widespread availability of two recent technologies: precise three-dimensional scanning/digitizing of complex surfaces and computer-controlled rapid prototyping three-dimensional "printers". Laser Doppler imaging may be the sensible method to track the scar hyperemia that should form the basis of assessing progress and directing incremental changes in the digitized topographical face mask "prescription". The purpose of this study was to establish feasibility of detecting perfusion through transparent face masks using the Laser Doppler Imaging scanner. Laser Doppler images of perfusion were obtained at multiple facial regions on five uninjured staff members. Images were obtained without a mask, followed by images with a loose fitting mask with and without a silicone liner, and then with a tight fitting mask with and without a silicone liner. Right and left oblique images, in addition to the frontal images, were used to overcome unobtainable measurements at the extremes of face mask curvature. General linear model, mixed model, and t tests were used for data analysis. Three hundred seventy-five measurements were used for analysis, with a mean perfusion unit of 299 and pixel validity of 97%. The effect of face mask pressure with and without the silicone liner was readily quantified with significant changes in mean cutaneous blood flow (P < .5). High valid pixel rate laser Doppler imager flow data can be obtained through transparent face masks. Perfusion decreases with the application of pressure and with silicone. Every participant measured differently in perfusion units; however, consistent perfusion patterns in the face were observed.

How long a shadow does epidemic obesity cast in the burn unit? A dietitian's analysis of the strengths and weaknesses of the available data in the National Burn Repository.

To demonstrate the research potential of the National Burn Repository, we examined outcomes affecting the obese burn population, specifically length of stay and mortality. This retrospective analysis evaluates burn patients from the repository coded as "obese." We queried admissions from burn units between the years 2000 to 2006 (n = 101,450). We initially intended to associate and stratify obesity with several complications and outcomes using multivariate analysis. However, because of the lack of standardized data fields, a surrogate yard stick (length of stay > or =7 days) was a straightforward and sensible outcome measurement. Mortality was used as a second outcome measurement. Two statistical approaches were used: logistic regression and the Cochran-Mantel-Haenszel test. Obese patients were 4.1 times more likely to have a length of stay > or =7 days (P < .0001) and were 2.6 times more likely to die (P < .0001) than patients not described as obese. The results not only highlighted obesity as a major challenge in burn care, but also identified means of improving the National Burn Repository to facilitate future nutrition research. The repository has vast potential to be a useful research tool for the dietitian. With standardization of the data dictionary and the addition of nutrition-related fields, such as height and weight, future research will be greatly enhanced.