A Versatile AuNP Synthetic Platform for Decoupled Control of Size and Surface Composition.

While a plethora of protocols exist for the synthesis of sub-10-nm gold nanoparticles (AuNPs), independent control over the size and surface composition remains restricted. This poses a particular challenge for systematic studies of AuNP structure-function relationships and the optimization of crucial design parameters. To this end, we report on a modular two-step approach based on the synthesis of AuNPs in oleylamine (OAm) followed by subsequent functionalization with thiol ligands and mixtures thereof. The synthesis of OAm-capped AuNPs enables fine-tuning of the core size in the range of 2-7 nm by varying the reaction temperature. The subsequent thiol-for-OAm ligand exchange allows a reliable generation of thiol-capped AuNPs with target surface functionality. The compatibility of this approach with a vast library of thiol ligands provides detailed control of the mixed ligand composition and solubility in a wide range of solvents ranging from water to hexane. This decoupled control over the AuNP core and ligand shell provides a powerful toolbox for the methodical screening of optimal design parameters and facile preparation of AuNPs with target properties.

Phase behaviour and applications of a binary liquid mixture of methanol and a thermotropic liquid crystal.

Herein, we report on the phase behaviour of a binary liquid mixture composed of methanol (MeOH) and the thermotropic liquid crystal 4-cyano-4'-pentylbiphenyl (5CB). The corresponding phase diagram combines features of a conventional liquid-liquid mixture with characteristics that are particular to the nematic liquid crystal. We observe four arrangements as a function of composition and temperature, namely monophasic isotropic, monophasic nematic, biphasic isotropic-isotropic and biphasic isotropic-nematic, with an upper critical solution temperature of 24.4 ± 0.5 °C. The interplay of nematogenic and non-nematogenic species offers tunability of phase mixing and phase composition in an accessible temperature window and provides novel routes for the extraction of target compounds, here exemplarily shown for Crystal Violet, Doxorubicin, Eosin Y, Rhodamine 6G and Sudan IV.

Engineering the nanoscale morphology of a quantum dot-fullerene assembly via complementary hydrogen bonding interactions.

We have demonstrated controlled assembly between CdSe quantum dots (QDs) and a fullerene (C60) derivative via complementary three-point hydrogen bonding interactions. The recognition-mediated assembly facilitated an interpenetrated network morphology and hence efficient charge transfer from QD to C60.

Beyond the Interface: Improved Pulmonary Surfactant-Assisted Drug Delivery through Surface-Associated Structures.

Pulmonary surfactant (PS) has been proposed as an efficient drug delivery vehicle for inhaled therapies. Its ability to adsorb and spread interfacially and transport different drugs associated with it has been studied mainly by different surface balance designs, typically interconnecting various compartments by interfacial paper bridges, mimicking in vitro the respiratory air-liquid interface. It has been demonstrated that only a monomolecular surface layer of PS/drug is able to cross this bridge. However, surfactant films are typically organized as multi-layered structures associated with the interface. The aim of this work was to explore the contribution of surface-associated structures to the spreading of PS and the transport of drugs. We have designed a novel vehiculization balance in which donor and recipient compartments are connected by a whole three-dimensional layer of liquid and not only by an interfacial bridge. By combining different surfactant formulations and liposomes with a fluorescent lipid dye and a model hydrophobic drug, budesonide (BUD), we observed that the use of the bridge significantly reduced the transfer of lipids and drug through the air-liquid interface in comparison to what can be spread through a fully open interfacial liquid layer. We conclude that three-dimensional structures connected to the surfactant interfacial film can provide an important additional contribution to interfacial delivery, as they are able to transport significant amounts of lipids and drugs during surfactant spreading.

Reversible Microscale Assembly of Nanoparticles Driven by the Phase Transition of a Thermotropic Liquid Crystal.

The arrangement of nanoscale building blocks into patterns with microscale periodicity is challenging to achieve via self-assembly processes. Here, we report on the phase-transition-driven collective assembly of gold nanoparticles in a thermotropic liquid crystal. A temperature-induced transition from the isotropic to the nematic phase under anchoring-driven planar alignment leads to the assembly of individual nanometer-sized particles into arrays of micrometer-sized agglomerates, whose size and characteristic spacing can be tuned by varying the cooling rate. Phase field simulations coupling the conserved and nonconserved order parameters exhibit a similar evolution of the morphology as the experimental observations. This fully reversible process offers control over structural order on the microscopic level and is an interesting model system for the programmable and reconfigurable patterning of nanocomposites with access to micrometer-sized periodicities.

Accuracy and quality of clinical decision rules for syncope in the emergency department: a systematic review and meta-analysis.

STUDY OBJECTIVE: We assess the methodological quality and prognostic accuracy of clinical decision rules in emergency department (ED) syncope patients. METHODS: We searched 6 electronic databases, reviewed reference lists of included studies, and contacted content experts to identify articles for review. Studies that derived or validated clinical decision rules in ED syncope patients were included. Two reviewers independently screened records for relevance, selected studies for inclusion, assessed study quality, and abstracted data. Random-effects meta-analysis was used to pool diagnostic performance estimates across studies that derived or validated the same clinical decision rule. Between-study heterogeneity was assessed with the I(2) statistic, and subgroup hypotheses were tested with a test of interaction. RESULTS: We identified 18 eligible studies. Deficiencies in outcome (blinding) and interrater reliability assessment were the most common methodological weaknesses. Meta-analysis of the San Francisco Syncope Rule (sensitivity 86% [95% confidence interval {CI} 83% to 89%]; specificity 49% [95% CI 48% to 51%]) and the Osservatorio Epidemiologico sulla Sincope nel Lazio risk score (sensitivity 95% [95% CI 88% to 98%]; specificity 31% [95% CI 29% to 34%]). Subgroup analysis identified study design (prospective, diagnostic odds ratio 8.82 [95% CI 3.5 to 22] versus retrospective, diagnostic odds ratio 2.45 [95% CI 0.96 to 6.21]) and ECG determination (by evaluating physician, diagnostic odds ratio 25.5 [95% CI 4.41 to 148] versus researcher or cardiologist, diagnostic odds ratio 4 [95% CI 2.15 to 7.55]) as potential explanations for the variability in San Francisco Syncope Rule performance. CONCLUSION: The methodological quality and prognostic accuracy of clinical decision rules for syncope are limited. Differences in study design and ECG interpretation may account for the variable prognostic performance of the San Francisco Syncope Rule when validated in different practice settings.

Emergency Department hyperglycemia as a predictor of early mortality and worse functional outcome after intracerebral hemorrhage.

BACKGROUND: We have previously reported the association of hyperglycemia and mortality after ischemic stroke. This study attempts to answer the hypothesis, if hyperglycemia at arrival, is associated with early mortality and functional outcome in patients with acute non-traumatic intracerebral hemorrhage (ICH). METHODS: The study cohort consisted of 237 patients who presented to the ED with ICH and had blood glucose measured on ED presentation. The presence of hyperglycemia on presentation was correlated with outcome measures including volume of hematoma, intraventricular extension of hematoma (IVE), stroke severity, functional outcome at discharge, and date of death. RESULTS: Of the cohort of 237 patients, a total of 47 patients had prior history of Diabetes Mellitus (DM). Median blood glucose at presentation was 140 mg/dl (Inter-quartile range 112-181 mg/dl). DM patients had higher glucose levels on arrival (median 202 mg/dl for DM vs. 132.5 mg/dl for non-DM, P < 0.0001). Higher blood glucose at ED arrival was associated with early mortality in both non-diabetics and diabetics (P < 0.0001). Higher blood glucose was associated with poor functional outcome in non-DM patients(P < 0.0001) but not in DM patients (P = 0.268). In the logistic regression model, after adjustment for stroke severity, hematoma volume, and IVE of hemorrhage, higher initial blood glucose was a significant predictor of death (P = 0.0031); as well as bad outcome in non-DM patients (P = 0.004). CONCLUSIONS: Hyperglycemia on presentation in non-diabetic patients is an independent predictor of early mortality and worse functional outcome in patients with intracerebral hemorrhage.

Evaluation and management of renal colic in the emergency department.

Renal stones (nephrolithiasis) are a relatively common problem and a frequent Emergency Department (ED) diagnosis in patients who present with acute flank/abdominal pain. The goal of this topic review is to provide physicians with an evidence-based diagnostic approach for the evaluation and management of patients with nephrolithiasis. Unenhanced helical CT scan of the abdomen and pelvis should be performed on all patients with their first episode of acute flank pain and suspected renal colic. It is considered the optimal diagnostic test to confirm a urinary stone in a patient with flank pain. Pain management can be achieved by using NSAIDs, opioids or a combination of both. Several factors will help you determine if emergent urology evaluation is warranted; size and location of renal calculi, persistence of colic pain, impaired renal function and signs of infection.

Coplanar Donor-π-Acceptor Dyes Featuring a Furylethynyl Spacer for Dye-Sensitized Solar Cells.

Coplanar metal-free organic dyes featuring a furylethynyl spacer with different donor residues (MeO-, MeS-, and Me2N-) have been synthesized. Density functional theory (DFT) calculations predicted that the Me2N- residue would facilitate more effective charge transfer from donor to acceptor than the MeO- and MeS- residues. In agreement with DFT calculations, the dye-sensitized solar cells (DSSCs) fabricated with the Me2N- functionalized dye exhibited the best power conversion efficiency (η), 2.88%. Furthermore, the effect of the furan spacer on the photophysical properties and DSSC parameters are discussed in comparison to a previously reported thiophene counterpart.

pH-Mediated molecular differentiation for fluorimetric quantification of chemotherapeutic drugs in human plasma.

At present, drug dosage is based on standardised approaches that disregard pharmakokinetic differences between patients and lead to non-optimal efficacy and unnecessary side effects. In this work, we demonstrate the potential of pH-mediated fluorescence spectroscopy for therapeutic drug monitoring in complex media. We apply this principle to the simultaneous quantification of the chemotherapeutic prodrug Irinotecan and its active metabolite SN-38 from human plasma across the clinically relevant concentration range, i.e. from micromolar to nanomolar at molar ratios of up to 30 : 1.

Effect of Annealing on Exciton Diffusion in a High Performance Small Molecule Organic Photovoltaic Material.

Singlet exciton diffusion was studied in the efficient organic photovoltaic electron donor material DTS(FBTTh2)2. Three complementary time-resolved fluorescence measurements were performed: quenching in planar heterojunctions with an electron acceptor, exciton-exciton annihilation, and fluorescence depolarization. The average exciton diffusivity increases upon annealing from 1.6 × 10-3 to 3.6 × 10-3 cm2 s-1, resulting in an enhancement of the mean two-dimensional exciton diffusion length (LD = (4Dτ)1/2) from 15 to 27 nm. About 30% of the excitons get trapped very quickly in as-cast films. The high exciton diffusion coefficient of the material leads to it being able to harvest excitons efficiently from large donor domains in bulk heterojunctions.

Outcomes of endoscopic optic nerve decompression in patients with idiopathic intracranial hypertension.

BACKGROUND: The conventional treatment for idiopathic intracranial hypertension involves weight loss, steroids, diuretics, and/or serial lumbar punctures; however, if the symptoms persist or worsen, surgical intervention is recommended. Surgical options include cerebrospinal fluid diversion procedures, such as ventriculoperitoneal and lumboperitoneal shunts, and optic nerve decompression with nerve sheath fenestration. The latter can be carried out using an endoscopic approach, but the outcomes of this technique have not been firmly established. METHODS: This systematic review examined the outcomes of performing endoscopic optic nerve decompression (EOND) in patients with idiopathic intracranial hypertension (IIH). Six studies were included for a total of 34 patients. RESULTS: The patients presented with visual field disturbances (32 of 32 [100%]), visual acuity disruptions (33 of 34 [97.1%]), papilledema (26 of 34 [76.5%]), and persistent headache (30 of 33 [90.1%]). The mean duration of symptoms ranged from 7 to 32 months. Overall, the patients showed post-EOND improvement in signs and symptoms associated with IIH, specifically visual field deficits (93.8%), visual acuity (85.3%), papilledema (81.4%), and headaches (81.8%). Interestingly, 11 cases showed postoperative improvement in their symptoms with bony decompression of the optic canal alone, without nerve sheath fenestration. There were no major adverse events or complications reported with this approach. CONCLUSION: EOND appears to be a promising and safe surgical alternative for patients with IIH who fail to respond to medical treatment. Further studies are needed before we can attest to the clinical validity of this procedure.

Opportunities for Emergency Medical Services (EMS) Care of Syncope.

UNLABELLED: Introduction Emergency Medical Service (EMS) systems are vital in the identification, assessment, and treatment of trauma, stroke, myocardial infarction, and sepsis patients, improving early recognition, resuscitation, and transport. Emergency Medical Service personnel provide similar care for patients with syncope. The role of EMS in the management of patients with syncope has not been reported. Hypothesis/Objective The objective of this study was to describe the management of out-of-hospital syncope by prehospital providers in an urban EMS system. METHODS: This was a retrospective cohort study of consecutively enrolled patients over 18 years of age, over a two-year period, who presented by EMS with syncope, or near-syncope, to a tertiary care emergency department (ED). Demographics included comorbidities, history, and physical exam findings documented by prehospital providers, as well as the interventions provided. Data were collected from standardized patient care records for descriptive analysis. RESULTS: Of the 723 patients presenting with syncope to the ED, 284 (39.3%) were transported by EMS. Compared to non-EMS patients, those who arrived by ambulance were older (mean age 65 [SD = 18.5] years versus 61 [SD = 19.2] years; P = .019). There were no statistically significant differences in cardiovascular comorbidities (hypertension, coronary artery disease, diabetes mellitus, stroke, or congestive heart failure) between EMS and non-EMS patients. The most common chief complaints were fainting (50.0%) and dizziness (44.7%). The most common intervention provided was cardiac monitoring (55.6%), followed by administration of normal saline infusion (50.5%), oxygen (41.9%), blood glucose check (41.5%), and electrocardiogram (EKG; 40.5%). CONCLUSION: Emergency Medical Service personnel transport more than one-third of patients presenting to the ED with syncope. Documentation of key elements of the history (witnesses, prodrome, predisposing factors, and post-event symptoms) and physical examination were not recorded consistently. Long BJ , Serrano LA , Cabanas JG , Bellolio MF . Opportunities for Emergency Medical Services (EMS) care of syncope. Prehosp Disaster Med. 2016;31(4):349-352.

The impact of driving force on electron transfer rates in photovoltaic donor-acceptor blends.

The effect of acceptor energy level on electron transfer rate in blends of the polymer solar-cell material poly[[4,8-bis[(2-ethylhexyl)oxy]benzo[1,2-b:4,5-b']dithiophene-2,6-diyl][3-fluoro-2-[(2-ethylhexyl)carbonyl]thieno[3,4-b]thiophenediyl]] (PTB7) is studied using time-resolved fluorescence. Fast electron transfer in less than 2 ps is observed for a driving force between 0.2 and 0.6 eV and the electron transfer is slower outside this range. This dependence is described by Marcus theory with a reorganization energy of ≈0.4 eV.

Determining the optimum morphology in high-performance polymer-fullerene organic photovoltaic cells.

The morphology of bulk heterojunction organic photovoltaic cells controls many of the performance characteristics of devices. However, measuring this morphology is challenging because of the small length-scales and low contrast between organic materials. Here we use nanoscale photocurrent mapping, ultrafast fluorescence and exciton diffusion to observe the detailed morphology of a high-performance blend of PTB7:PC71BM. We show that optimized blends consist of elongated fullerene-rich and polymer-rich fibre-like domains, which are 10-50 nm wide and 200-400 nm long. These elongated domains provide a concentration gradient for directional charge diffusion that helps in the extraction of charge pairs with 80% efficiency. In contrast, blends with agglomerated fullerene domains show a much lower efficiency of charge extraction of ~45%, which is attributed to poor electron and hole transport. Our results show that the formation of narrow and elongated domains is desirable for efficient bulk heterojunction solar cells.

Effect of anticoagulant and antiplatelet therapy in patients with spontaneous intra-cerebral hemorrhage: Does medication use predict worse outcome?

OBJECTIVES: To assess the impact of anticoagulants and antiplatelet agents on the severity and outcome of spontaneous non-traumatic intra-cerebral hemorrhage (ICH). To evaluate associations between reversal of anticoagulation and mortality/morbidity in these patients. METHODS: Data was collected on a consecutive cohort of adults presenting with ICH to an academic Emergency Department over a 3-year period starting January 2006. RESULTS: The final cohort of 245 patients consisted of 125 females (51.1%). The median age of the cohort was 73 years [inter-quartile (IQR) range of 59-82 years]. Antiplatelet (AP) use was seen in 32.6%, 18.4% were using anticoagulant (AC) and 8.9% patients were on both drugs (AC+AP). Patients on AC had significantly higher INR (median 2.3) and aPTT (median 31 s) when compared to patients not on AP/AC (median INR 1.0, median aPTT 24s; p<0.001). Similarly patients on AC+AP also had higher INR (median 1.9) and aPTT (median 30s) when compared to those not on AC/AP (p<0.001). Hemorrhage volumes were significantly higher for patients on AC alone (median 64.7 cm(3)) when compared to those not on either AC/AP (median 27.2 cm(3); p=0.05). The same was not found for patients using AP (median volume 20.5 cm(3); p=0.813), or both AC+AP (median volume 27.7 cm(3); p=0.619). Patients on AC were 1.43 times higher at risk to have intra-ventricular extension of hemorrhage (IVE) as compared to patients not on AC/AP (95% CI 1.04-1.98; p=0.035). There was no relationship between the use of AC/AP/AC+AP and functional outcome of patients. Patients on AC were 1.74 times more likely to die within 7 days (95% CI 1.0-3.03; p=0.05). No relationship was found between use of AP or AC+AP use and mortality. Of the 82 patients with INR>1.0, 52 patients were given reversal (minimum INR 1.4, median 2.3). Therapy was heterogeneous, with fresh frozen plasma (FFP) being the most commonly used agent (86.5% patients, median dose 4U). Vitamin K, activated factor VIIa and platelets were the other agents used. Post reversal, INR normalized within 24h (median 1.2, IQR 1.1-1.3). There was no association between reversal and volume of hemorrhage, IVE, early mortality (death<7 days) or functional outcome. CONCLUSIONS: Anticoagulated patients were at 1.7 times higher risk of early mortality after ICH. Reversal of INR to normal did not influence mortality or functional outcome.