Hydroxy-Functionalized Ionic Liquids under Pressure: The Influence on Hydrogen Bonding between Ions of Opposite and Like Charges

Hydroxy functionalization of cations in ionic liquids (ILs) can lead to formation of hydrogen bonds between their OH groups, resulting in so-called (c-c) H-bonds. Thereby, the (c-c) H-bonds compete with regular H-bonds (c-a) between the OH groups and the anions. Polarizable cations, weakly interacting anions, and long alkyl chains at the cation support the propensity for the formation of (c-c) H-bonds. At low temperatures, the equilibrium between (c-c) and (c-a) H-bonds is strongly shifted in favor of the cation-cation interaction. Herein, we clarify the pressure dependence on (c-c) and (c-a) H-bond distributions in the IL 1-(2-hydroxyethyl)-3-methylimidazolium hexafluorophosphate [HOC2C1Im][PF6], in mixtures of [HOC2C1Im][PF6] with the nonhydroxy-functionalized IL 1-propyl-3-methylimidazolium hexafluorophosphate [C3C1Im][PF6] and in [HOC2C1Im][PF6] including trace amounts of water. The infrared (IR) spectra provide clear evidence that the (c-c) H-bonds diminish with increasing pressure in favor of the (c-a) H-bonds. Adding trace amounts of water results in enhanced (c-c) clustering due to cooperative effects. At ambient pressure, the water molecules are involved in the (c-c) H-bond motifs. Increasing pressure leads to squeezing them out of H-bond clusters, finally resulting in demixing of water and the IL at the microscopic level.

Exploring the Benefits of 3D-Printed Bolus in Cone Beam CT for Modified Radical Mastectomy Breast Cancer

PURPOSE/OBJECTIVE(S)

To improve the accuracy of superficial dose coverage for patients undergoing modified radical mastectomy (MRM), boluses are frequently applied to the skin surface of targeted region during radiotherapy. The irregular curvature of MRM breast cases results in discrepancies of dosimetry and poor contact. Additionally, the presence of an air gap causes unnecessary high-dose escalation and uncertainty in dose calculation, making the use of commercial flat bolus problematic. This study evaluated the effectiveness of 3D-printed bolus by comparing it to commercial bolus in setup variations and dosimetric compliance through daily cone-beam computed tomography (CBCT) scans.

MATERIALS/METHODS

Ten patients underwent MRM were divided into 2 groups. 5 patients treated with 0.5 cm commercial bolus as group A while the other 5 patients covered by 3D Bolus as group B. 3D bolus was made of polylactic acid filament (PLA) and contoured in advance with thickness of 0.5 cm on the surface of target. Positional errors were recorded through daily image guidance and compared with the images. Both groups had right-sided breast with neck lymph nodes involved and received 50 Gy in 25 fractions using 4 partial arcs of the volumetric modulated arc therapy (VMAT) technique. The CBCTs were recalculated through treatment planning system (TPS) to assess superficial dose coverage. A two-tailed student's t-test was applied.

RESULTS

Groups A and B pitch angles were -0.203 ± 0.837° and 0.334 ± 0.909° (p = 0.0003). Roll angle were 0.313 ± 0.728° and -0.633 ± 1.286° (p = 0.0000013). Yaw angle were -0.034 ± 0.872° and 0.018 ± 0.883° (p = 0.721). There was a trend of differences in the Z-axis and significant statistical differences in the pitch and roll angles due to aligning gel layers directly with group A's body surface, while 3D bolus rigidly adherence to group B's delineated curve. In the planned target volume (PTV), the CI and HI of group A were 0.9448±0.0208 and 1.2061±0.0448, respectively, while 0.9776±0.0144 and 1.1472±0.0206 (p<0.005) were for group B. As for the superficial region, which is defined from body surface to 0.5cm inside PTV, CI and HI of A were 0.8290±0.0599 and 1.4675±0.2434, while for B, they were 0.9753±0.0214 and 1.1330±0.0126, respectively (p<0.005).

CONCLUSION

The study analyzed the results through image comparison and investigated the CI and HI between two types of boluses. The 3D bolus reduces setup errors and improves dose coverage especially when superficial region is concerned. Better consistency of patient repositioning and dosimetry can be achieved and proved by daily assessment of CBCT scan. The customization of 3D bolus with integration of TPS and CT scans provides a solution to the inadequacies of commercial bolus. The results suggest that the use of 3D bolus is a promising development in radiation therapy for MRM breast cancer patients.

Left ventricular apical aneurysm in Fabry disease: implications for clinical significance and risk stratification

Funding Acknowledgements

Type of funding sources: None.

Background

More than 50% of patients with Fabry disease (FD) present with cardiac phenotype, and left ventricular hypertrophy (LVH) is the most frequent manifestation. Among FD patients with LVH, a rare and novel presentation of left ventricular apical aneurysm (LVAA) has been reported.

Purpose

This study aimed to investigate the clinical incidence of LVAA and its impacts on prognosis among FD patients.

Methods

We retrospectively analyzed 268 FD patients at a tertiary medical center between January 2003 to September 2020. Two patients with ischemic LVAA were excluded. LVH and LVAA were confirmed either by echocardiography (Figure 1A) or cardiovascular magnetic resonance imaging (Figure 1B). The primary endpoints were a composite of heart failure (HF) hospitalization, sustained ventricular tachycardia (VT), stroke, and death. 

Results

Of 266 FD patients, there were 105 (39.5%) patients had LVH, and 11 (10.3%) of them had LVAAs (age 67.5 ± 9.5 years, 8 males [72.7%]). After a mean follow-up of 49.3 ± 34.8 months, 8 patients experienced primary endpoints, including 5 (45.5%) HF hospitalizations, 3 (27.3%) VT, 1 (9.1%) stroke, and 4 (36.4%) deaths. The risk for composite adverse events was significantly higher in patients with LVAA compared with those without (8 [72.7%] vs 17 [18.1%]), leading to significantly lower event-free survival in patients with LVAA (Log-Rank P &lt; 0.001, Figure 2). The presence of LVAA was independently associated with an increased risk of composite adverse events (hazard ratio: 3.59; confidence interval: 1.30-9.91, P = 0.01) after adjusting for age, gender, advanced HF, renal function, dyslipidemia, atrial fibrillation, left ventricular ejection fraction of &lt;40%, average E/e’, and LV mass index.

Conclusions

LVAA presents in around 10% of patients with Fabry cardiomyopathy and is strongly associated with an increased risk of adverse events. The identification of this phenotype would be useful to identify high-risk patients with Fabry cardiomyopathy, among whom more aggressive treatments may be considered. Abstract Figure. Apical aneurysm in Fabry cardiomyopathy  Abstract Figure. KM curve of composite adverse events

Pressure-Dependent Clustering in Ionic-Liquid-Poly (Vinylidene Fluoride) Mixtures: An Infrared Spectroscopic Study

The nanostructures of ionic liquids (ILs) have been the focus of considerable research attention in recent years. Nevertheless, the nanoscale structures of ILs in the presence of polymers have not been described in detail at present. In this study, nanostructures of ILs disturbed by poly(vinylidene fluoride) (PVdF) were investigated via high-pressure infrared spectra. For 1-(2-hydroxyethyl)-3-methylimidazolium bis(trifluoromethanesulfonyl)imide ([HEMIm][TFSI])-PVdF mixtures, non-monotonic frequency shifts of the C^4,5-H vibrations upon dilution were observed under ambient pressure. The experimental results suggest the presence of microheterogeneity in the [HEMIm][TFSI] systems. Upon compression, PVdF further influenced the local structure of C^4,5–H via pressure-enhanced IL–PVdF interactions; however, the local structures of C²–H and hydrogen-bonded O–H were not affected by PVdF under high pressures. For choline [TFSI]–PVdF mixtures, PVdF may disturb the local structures of hydrogen-bonded O–H. In the absence of the C^4,5–H⋯anion and C²–H⋯anion in choline [TFSI]–PVdF mixtures, the O–H group becomes a favorable moiety for pressure-enhanced IL–PVdF interactions. Our results indicate the potential of high-pressure application for designing pressure-dependent electronic switches based on the possible changes in the microheterogeneity and electrical conductivity in IL-PVdF systems under various pressures.

Pulmonary pressure-to-longitudinal strain ratio by echocardiography: a rapid surrogate to magnetic resonance for right ventricular failure assessment

Funding Acknowledgements

Type of funding sources: Public hospital(s). Main funding source(s): United Christian Hospital Ruttonjee and Tang Siu Kin Hospitals

Background

Better risk stratification in pulmonary hypertension (PH) by echocardiography (echo) to detect ventricular vascular uncoupling may act as gate-keeper for downstream management, such as MRI and expensive therapies. Studies showed modest correlation found between RV peak global longitudinal strain (RVGLS), which is afterload dependent, and right ventricular ejection fraction (RVEF)

Purpose

To test the accuracy and optimal cut-off of echo derived mean PA pressure-to-RVGLS ratio against MRI detected severe RV dysfunction (defined as RVEF&lt; 35%), RV dilatation (defined as RVEDVi &gt;87ml), and correlate native T1-values (nT1)

Method

Strain analyses by echo and volumetric assessment by 1.5 tesla MRI were performed in all patients. Contoured MRI short axis images provided RVEF. In a subgroup of pulmonary arterial hypertension (PAH), right heart catheterization and MRI non-contrast native T1 mapping were performed (Figure 1). Using previous study data, to identify a difference of 1.8 pressure-to-strain ratio between mild and severe PH with a variance  of 2.2 , power of 80% and a significance level of 0.05, a total of 11 participants per group were needed

Result

Thirty-one PH patients (13 female, age 60 ± 14y, 13 had PAH) were recruited prospectively. Strong correlation was demonstrated between the mean PA pressure-to-RVGLS ratio to MRI derived RVEF (r = 0.80, p &lt; 0.01), and to catheterization derived pulmonary vascular resistance and indexed cardiac output (r = -0.80, p= 0.001; r= -0.75, p = 0.003 respectively). The cut-off value of -2.5 had best accuracy in ROC analyses (Table 1)

In PAH patients, this ratio correlated with global nT1 at basal short-axis level (r= -0.91, p = 0.004), but not at the mid short-axis level. Their basal posterior interventricular insertion regions had significantly higher nT1 than those of age-matched normal controls at the same region on the same scanner (1256 ± 217 ms vs. 932 ± 25 ms, p = 0.04)

Conclusion

In terms of detection of severe right ventricular dysfunction by echocardiography, mean PA pressure-to-RVGLS ratio performed better than RVGLS alone, and a ratio cutoff of -2.5 predicts MRI determined ventricular vascular uncoupling in pulmonary hypertension

Table 1 Echo detect MRI AUC standard error 95% CI sens (%) spec (%) p Mean PA pressure -to-RVGLS ratio RVEF &lt; 35% 0.86 0.073 0.71-1.00 72 83 0.007 RVEDVi &gt; 87ml 0.81 0.081 0.65-0.97 83 70 0.004 RVGLS RVEF &lt; 35% 0.76 0.100 0.57-0.96 60 83 0.048 RVEDVi &gt; 87ml 0.73 0.090 0.55-0.91 67 70 0.032 PA pulmonary artery; RVGLS: RV global longitudinal strain; RVEDVi: indexed RV end-diastolic volume Abstract Figure 1

Structural Reorganization of Imidazolium Ionic Liquids Induced by Pressure-Enhanced Ionic Liquid-Polyethylene Oxide Interactions

Mixtures of polyethylene oxide (PEO, M.W.~900,000) and imidazolium ionic liquids (ILs) are studied using high-pressure Fourier-transform infrared spectroscopy. At ambient pressure, the spectral features in the C-H stretching region reveal that PEO can disturb the local structures of the imidazolium rings of [BMIM]+ and [HMIM]+. The pressure-induced phase transition of pure 1-butyl-3-methylimidazolium bromide ([BMIM]Br) is observed at a pressure of 0.4 GPa. Pressure-enhanced [BMIM]Br-PEO interactions may assist PEO in dividing [BMIM]Br clusters to hinder the aggregation of [BMIM]Br under high pressures. The C-H absorptions of pure 1-hexyl-3-methylimidazolium bromide [HMIM]Br do not show band narrowing under high pressures, as observed for pure [BMIM]Br. The band narrowing of C-H peaks is observed at 1.5 GPa for the [HMIM]Br-PEO mixture containing 80 wt% of [HMIM]Br. The presence of PEO may reorganize [HMIM]Br clusters into a semi-crystalline network under high pressures. The differences in aggregation states for ambient-pressure phase and high-pressure phase may suggest the potential of [HMIM]Br-PEO (M.W.~900,000) for serving as optical or electronic switches.

P923Feasibility of the transcatheter mitral valve repair as the rescue therapy for patients with severe mitral regurgitation and endangered heart failure

Background

For those who carry high or prohibitive surgical risk, the transcatheter edge-to edge mitral valve repair using MitraClip has been a safe and effective treatment for severe mitral regurgitation (MR). In patients with severe MR and cardiogenic shock under hemodynamic supporting devices, emergent surgical mitral valve interventions carry extremely high risk for peri-operative morbidities and mortalities. The feasibility and efficacy of emergent MitraClip to rescue patients in critical conditions remains elucidate.

Methods

Patients with severe MR were evaluated by the heart team and those with high or prohibitive surgical risks were referred to receive MitraClip procedures. Emergent MitraClip were conducted in patients with unstable hemodynamics and under mechanical or inotropic support. The hemodynamic measures, transthoracic echocardiography, transesophageal echocardiography, and blood tests were performed before MitraClip procedures. Procedural success was defined as having mild mitral regurgitation immediately after MitraClip, and patients were free from in-hospital mortality. Clinical and echocardiographic outcomes were followed by telephones and clinics.

Results

Among 50 consecutive patients (74.7±11.2 years, 74% male), 8 emergent MitraClip procedures were conducted to rescue patients with cardiogenic shock. Extracorporeal membrane oxygenation were used in 2 patients and intra-aortic balloon pump were applied in 4 patients (50%). The rest of 4 patients received continuous inotropic agent administration. Compare to those who underwent elective procedures, patients underwent emergent MitraClip had higher surgical risk profile (Euroscore II 34.8% vs 5.1% and STS score 19.7% vs 5.1%), poorer renal function and higher right atrial pressure. There was no peri-procedural death, myocardial infarction, stroke or any adverse events requiring emergent cardiac surgery in both groups. Mild mitral regurgitation was achieved in 87.5% patients from the emergent group and 95.2% patients in the elective group (P=0.514). In follow up, there were 5 deaths (three in the emergent group), including 2 non-cardiovascular deaths. The Kaplan-Meier analysis showed patients who underwent emergent procedures have poorer long-term survival rate as compare to those who received elective procedures. (P value = 0.008).

Conclusions

When open-heart surgery is not feasible and deferred due to excessive risk, trans-catheter mitral valve repair is an alternative way to rescue patients in cardiogenic shock status. The emergent MitraClip procedure may provide comparable safety and efficacy in treating patients with severe MR and unstable hemodynamics.

The Nature of Cation-Anion Interactions in Magnetic Ionic Liquids as Revealed Using High-Pressure Fourier Transform Infrared (FT-IR) Spectroscopy

Magnetic ionic liquids are a group of magneto-responsive compounds that typically possess high ionic conductivities and low vapor pressures. In spite of the general interest in these materials, a number of questions concerning the fundamental interactions among the ions remain unanswered. We used vibrational spectroscopy to gain insight into the nature of these interactions. Intramolecular vibrational modes of the ions are quite sensitive to their local potential energy environments, which are ultimately defined by cation-anion coordination schemes present among the ions. Ambient pressure Fourier transform infrared (FT-IR) spectroscopy indicates comparable interaction motifs for 1-ethyl-3-methylimidazolium tetrachloroferrate(III), [emim]FeCl₄, and 1-ethyl-3-methylimidazolium tetrabromoferrate(III), [emim]FeBr₄, magnetic ionic liquids. However, the vibrational modes of [emim]FeCl₄ generally occur at slightly higher frequencies than those of [emim]FeBr₄. These differences reflect different interaction strengths between the [emim]⁺ cations and FeCl4- or FeBr4- anions. This conclusion is supported by gas-phase ab initio calculations of single [emim]FeCl₄ and [emim]FeBr₄ ion pairs that show longer C-H···Br-Fe interaction lengths compared to C-H···Cl-Fe. Although the IR spectra of [emim]FeCl₄ and [emim]FeBr₄ are comparable at ambient pressure, a different series of spectroscopic changes transpire when pressure is applied to these compounds. This suggests [emim]⁺ cations experience different types of interaction with the anions under high-pressure conditions. The pressure-dependent FT-IR spectra highlights the critical role ligands attached to the tetrahalogenoferrate(III) anions play in modulating cation-anion interactions in magnetic ionic liquids.

Pressure-Dependent Confinement Effect of Ionic Liquids in Porous Silica

The effect of confining ionic liquids (ILs) such as 1-ethyl-3-methylimidazolium tetrafluoroborate [C₂C₁Im][BF₄] or 1-butyl-3-methylimidazolium tetrafluoroborate [C₄C₁Im][BF₄] in silica matrices was investigated by high-pressure IR spectroscopy. The samples were prepared via the sol-gel method, and the pressure-dependent changes in the C–H absorption bands were investigated. No appreciable changes were observed in the spectral features when the ILs were confined in silica matrices under ambient pressure. That is, the infrared measurements obtained under ambient pressure were not sufficient to detect the interfacial interactions between the ILs and the porous silica. However, dramatic differences were observed in the spectral features of [C₂C₁Im][BF₄] and [C₄C₁Im][BF₄] in silica matrices under the conditions of high pressures. The surfaces of porous silica appeared to weaken the cation-anion interactions caused by pressure-enhanced interfacial IL-silica interactions. This confinement effect under high pressures was less obvious for [C₄C₁Im][BF₄]. The size of the cations appeared to play a prominent role in the IL-silica systems.

Utilizing Infrared Spectroscopy to Analyze the Interfacial Structures of Ionic Liquids/Al₂O₃ and Ionic Liquids/Mica Mixtures under High Pressures

The interfacial interactions between ionic liquids (1,3-dimethylimidazolium methyl sulfate and 1-ethyl-3-methylimidazolium trifluoromethanesulfonate) and solid surfaces (mesoporous aluminum oxide and mica) have been studied by infrared spectroscopy at high pressures (up to 2.5 GPa). Under ambient pressure, the spectroscopic features of pure ionic liquids and mixtures of ionic liquids/solid particles (Al₂O₃ and mica) are similar. As the pressure is increased, the cooperative effect in the local structure of pure 1,3-dimethylimidazolium methyl sulfate becomes significantly enhanced as the imidazolium C–H absorptions of the ionic liquid are red-shifted. However, this pressure-enhanced effect is reduced by adding the solid particles (Al₂O₃ and mica) to 1,3-dimethylimidazolium methyl sulfate. Although high-pressure IR can detect the interactions between 1,3-dimethylimidazolium methyl sulfate and particle surfaces, the difference in the interfacial interactions in the mixtures of Al₂O₃ and mica is not clear. By changing the type of ionic liquid to 1-ethyl-3-methylimidazolium trifluoromethanesulfonate, the interfacial interactions become more sensitive to the type of solid surfaces. The mica particles in the mixture perturb the local structure of 1-ethyl-3-methylimidazolium trifluoromethanesulfonate under high pressures, forcing 1-ethyl-3-methylimidazolium trifluoromethanesulfonate to form into an isolated structure. For Al₂O₃, 1-ethyl-3-methylimidazolium trifluoromethanesulfonate tends to form an associated structure under high pressures.

Temperature- and pressure-dependent infrared spectroscopy of 1-butyl-3-methylimidazolium trifluoromethanesulfonate: A dipolar coupling theory analysis

Continued growth and development of ionic liquids requires a thorough understanding of how cation and anion molecular structure defines the liquid structure of the materials as well as the various properties that make them technologically useful. Infrared spectroscopy is frequently used to assess molecular-level interactions among the cations and anions of ionic liquids because the intramolecular vibrational modes of the ions are sensitive to the local potential energy environments in which they reside. Thus, different interaction modes among the ions may lead to different spectroscopic signatures in the vibrational spectra. Charge organization present in ionic liquids, such as 1-butyl-3-methylimidazolium trifluoromethanesulfonate ([C₄mim]CF₃SO₃), is frequently modeled in terms of a quasicrystalline structure. Highly structured quasilattices enable the dynamic coupling of vibrationally-induced dipole moments to produce optical dispersion and transverse optical-longitudinal optical (TO-LO) splitting of vibrational modes of the ionic liquid. According to dipolar coupling theory, the degree of TO-LO splitting is predicted to have a linear dependence on the number density of the ionic liquid. Both temperature and pressure will affect the number density of the ionic liquid and, therefore, the amount of TO-LO splitting for this mode. Therefore, we test these relationships through temperature- and pressure-dependent FT-IR spectroscopic studies of [C₄mim]CF₃SO₃, focusing on the totally symmetric SO stretching mode for the anion, ν_s(SO₃). Increased temperature decreases the amount of TO-LO splitting for ν_s(SO₃), whereas elevated pressure is found to increase the amount of band splitting. In both cases, the experimental observations follow the general predictions of dipolar coupling theory, thereby supporting the quasilattice model for this ionic liquid.

Interactions of ionic liquids and surfaces of graphene related nanoparticles under high pressures

High-pressure infrared spectroscopy was used to study the interactions between 1-methyl-3-propylimidazolium iodide [MPIM]I and graphene-based nanoparticles. The results obtained at ambient pressure indicate the imidazolium ring of the cation to be a more favorable moiety for adsorption than alkyl C-H groups at ambient pressure. Upon increasing the pressure, the dominant C²-H band of pure [MPIM]I yields a significant red frequency shift. As the mixtures, i.e., graphene oxide (GO)/[MPIM]I, reduced graphene oxide (RGO)/[MPIM]I, and graphene (G)/[MPIM]I, were compressed, mild shifts in the C²-H absorption frequency were observed. The absence of drastic red-shifts suggests that the local C²-H structures may be perturbed by the addition of GO, RGO, and G under high pressures. When pure [MPIM]I was compressed from ambient to 0.4 GPa, the alkyl C-H band at ca. 2964 cm^-1 was blue-shifted to 2984 cm^-1. This discontinuous jump occurring around 0.4 GPa becomes less obvious for the mixtures GO/[MPIM]I, RGO/[MPIM]I, and G/[MPIM]I. The results of this study suggest that the addition of GO, RGO, and G can disturb the local structures of alkyl C-H under high pressures, demonstrating that high pressures may have the potential to tune the strength of ionic liquid-surface interactions and the performance of energy storage devices (e.g. supercapacitors).

Fluid Restriction for Treatment of “Fluid Creep” after Acute Burn Resuscitation

Objective

Fluid creep in patients recovering from acute burns still exists, despite the use of a more treatment conservative approach. Most of our severe burn patients develop fluid overload and body weight increase after acute fluid resuscitation. How to quickly return patients to their pre-injury body weight is an important issue.

Methods

Right after acute fluid resuscitation, we applied a “total fluid requirement” volume (usually 1/2 to 2/3 of initial 24 hour volume) and strictly monitored patients' hourly urine (between 0.5-1 ml/kg/hr). Patients' responses (body weight, enteric feeding amount, pulmonary condition, etc.) were also closely monitored and frequent adjustments of fluid volume administration were performed simultaneously.

Results

Most patients regained their pre-injury body weight within 2-3 weeks. Enteric feeding also improved markedly. No patients had severe oedema-related complications.

Conclusions

Stricter fluid administration after acute burn fluid resuscitation is advised for allowing patients to reduce body weight to their pre-injury weight or at least close to it. We use pre-injury body weight, enteric feeding and urine output as our guides. (Hong Kong j.emerg.med. 2014;21:222-229)

Paddle Position and Contact Force: An Important Step to Check When Troubleshooting for Refractory Ventricular Fibrillation

Ventricular fibrillation (VF) is a lethal medical emergency that requires immediate defibrillation. VF is resistant when it persists after three or more defibrillator shocks. Successful defibrillation requires depolarisation of a critical mass of myocardium. Several variables, such as the length of time in VF, body type, total energy used, and energy waveform have been reported to be associated with the success rate of defibrillation. Correct paddle position and good contact force to create an adequate current flow through the heart is essential for defibrillation. We report a patient who developed VF because of acute myocardial infarction that was resistant to a total of 13 shocks. The cause of shock-resistant VF was diagnosed by noticing the skin marks caused by the defibrillator paddle that indicated incorrect paddle position and inadequate paddle force. By checking the skin marks, an emergency physician could make a correct diagnosis within a few seconds and save a patient.

The effect of pressure on cation-cellulose interactions in cellulose/ionic liquid mixtures

Cation-cellulose interactions in binary mixtures of [EMIM][OAc] and cellulose have been investigated using high-pressure infrared spectroscopy. At low concentrations of cellulose, almost no changes were observed in the imidazolium C(2)-H frequency; on the other hand, at high concentrations of cellulose, increases in the C(2)-H vibration frequency were observed under ambient pressure. As the pressure was elevated, the imidazolium C(2)-H absorption of the [EMIM][OAc]/cellulose mixtures underwent band-narrowing and blue-shifts in the frequency. These observations suggest that high pressures may strengthen the hydrogen bonds formed between C(2)-H and cellulose, possibly forcing the cellulose to dissociate clusters of ionic liquid through enhanced cation-cellulose interactions. In contrast to the cation-cellulose interaction results, the COO(-) absorption of the anion does not show dramatic changes under high pressures. Our results indicate the possibility of enhanced cation-cellulose interactions through pressure elevation, demonstrating that high pressures may have the potential to tune the relative contributions of cation-cellulose and anion-cellulose interactions in cellulose/ionic liquid mixtures.

Photon bunching in cathodoluminescence

We have measured the second order correlation function [g^{(2)}(τ)] of the cathodoluminescence intensity resulting from the excitation by fast electrons of defect centers in wide band-gap semiconductor nanocrystals of diamond and hexagonal boron nitride. We show that the cathodoluminescence second order correlation function g^{(2)}(τ) of multiple defect centers is dominated by a large, nanosecond zero-delay bunching (g^{(2)}(0)>30), in stark contrast to their flat photoluminescence g^{(2)}(τ) function. We have developed a model showing that this bunching can be attributed to the synchronized emission from several defect centers excited by the same electron through the deexcitation of a bulk plasmon into few electron-hole pairs.

Ambient pressure structural quantum critical point in the phase diagram of (Ca(x)Sr(1-x))(3)Rh(4)Sn(13)

The quasiskutterudite superconductor Sr_{3}Rh_{4}Sn_{13} features a pronounced anomaly in electrical resistivity at T^{*}∼138  K. We show that the anomaly is caused by a second-order structural transition, which can be tuned to 0 K by applying physical pressure and chemical pressure via the substitution of Ca for Sr. A broad superconducting dome is centered around the structural quantum critical point. Detailed analysis of the tuning parameter dependence of T^{*} as well as insights from lattice dynamics calculations strongly support the existence of a structural quantum critical point at ambient pressure when the fraction of Ca is 0.9 (i.e., x_{c}=0.9). This establishes the (Ca_{x}Sr_{1-x})_{3}Rh_{4}Sn_{13} series as an important system for exploring the physics of structural quantum criticality without the need of applying high pressures.

A systematic review on the use of daily subcutaneous administration of teriparatide for treatment of patients with osteoporosis at high risk for fracture in Asia

This systematic review aimed to examine the evidence for teriparatide in Asia for osteoporosis with a high fracture risk and for exploratory (unapproved) bone-related indications. MEDLINE (1946+), EMBASE (1966+), and ClinicalTrials.gov (2008+) were searched (16 August 2013); all studies of daily subcutaneous teriparatide 20 μg for bone-related conditions from China, Hong Kong, Japan, Republic of Korea, Philippines, Singapore, and Taiwan were included. Evidence on efficacy/safety was retrieved primarily from randomized controlled trials (10 publications) of postmenopausal women from Japan and China. In these studies, teriparatide was well tolerated; subjects had significantly greater increases in lumbar spine bone mineral density (BMD) from baseline compared with placebo, antiresorptive agents, or elcatonin/calcitonin; bone turnover markers increased from baseline and were sustained at elevated levels during teriparatide treatment. Few studies reported fracture risk, pain, or quality of life; one study showed a lower incidence of new-onset vertebral fracture with teriparatide versus antiresorptive agents. Nonrandomized studies (nine publications, one unpublished trial) conducted mainly in Taiwan, Japan, and the Republic of Korea provided supporting data for efficacy. The exploratory (unapproved) use of teriparatide (17 publications) for fracture healing and osteonecrosis of the jaw was described primarily in case reports. The clinical effectiveness of teriparatide for treatment of postmenopausal women with osteoporosis who are at high risk of fracture in Asia is focused primarily on improvements in BMD and tolerability. Recommended additional studies may include assessment of fracture risk and the effect of teriparatide on pain, quality of life, and mortality in Asia.

Pressure-enhanced surface interactions between nano-TiO2 and ionic liquid mixtures probed by high pressure IR spectroscopy

The formation of pressure-enhanced C–H⋯nano-TiO₂ interactions around the C–H groups was observed.

Advances in three-dimensional rapid prototyping of microfluidic devices for biological applications

The capability of 3D printing technologies for direct production of complex 3D structures in a single step has recently attracted an ever increasing interest within the field of microfluidics. Recently, ultrafast lasers have also allowed developing new methods for production of internal microfluidic channels within the bulk of glass and polymer materials by direct internal 3D laser writing. This review critically summarizes the latest advances in the production of microfluidic 3D structures by using 3D printing technologies and direct internal 3D laser writing fabrication methods. Current applications of these rapid prototyped microfluidic platforms in biology will be also discussed. These include imaging of cells and living organisms, electrochemical detection of viruses and neurotransmitters, and studies in drug transport and induced-release of adenosine triphosphate from erythrocytes.

Detection of a few metallo-protein molecules using color centers in nanodiamonds

Nanometer-sized diamonds containing nitrogen-vacancy defect centers (NV) are promising nanosensors in biological environments due to their biocompatibility, bright fluorescence, and high magnetic sensitivity at ambient conditions. Here we report on the detection of ferritin molecules using magnetic noise induced by the inner paramagnetic iron as a contrast mechanism. We observe a significant reduction of both coherence and relaxation time due to the presence of ferritin on the surface of nanodiamonds. Our theoretical model is in excellent agreement with the experimental data and establishes this method as a novel sensing technology for proteins.

Isradipine prevents rotenone-induced intracellular calcium rise that accelerates senescence in human neuroblastoma SH-SY5Y cells

Previous research demonstrated that rotenone (RT) induces neuronal injury partially by increasing intracellular Ca(2+) concentrations ([Ca(2+)]i), and inducing oxidative stress, leading to a neurodegenerative disorder. However, the mechanism of RT-induced injury remains elusive. Recent work revealed that Ca(2+) signaling is important for RT-induced senescence in human neuroblastoma SH-SY5Y cells. In the present study, we found that in SH-SY5Y cells, RT increased [Ca(2+)]i, senescence associated β-galactosidase activity, aggregation of lipofuscin, production of reactive oxygen species, G1/G0 cell cycle arrest, and activation of p53/p21 signaling proteins. In addition, RT decreased the expression of the signaling proteins for cell proliferation and survival, Cyclin-dependent kinase 2 (CDK2), cyclin D1, and Akt. Pretreatment of SH-SY5Y cells with isradipine, an L-type Ca(2+) channel blocker, or EGTA antagonized these effects of RT. These results suggested that application of isradipine might be a novel approach to prevent RT-induced neurodegenerative disorder such as Parkinson's disease.

Adverse postoperative outcomes in surgical patients with immune thrombocytopenia

Background

Patients with immune thrombocytopenia (ITP) are likely to have various medical co-morbidities, yet their global features regarding adverse postoperative outcomes and use of medical resources when undergoing major surgery are unknown. The objective of this study was to validate whether ITP is an independent risk factor for adverse postoperative outcomes, and to explore the potential clinical predictors of outcomes after major surgery among patients with ITP.

Methods

A retrospective population-based cohort study was conducted using Taiwan's National Health Insurance Research Database, controlling for preoperative co-morbidities by means of multiple logistic regression. Major postoperative complication and mortality rates, and in-hospital medical costs were analysed.

Results

The study included 11 085 surgical patients with ITP and 44 340 controls without ITP matched for sex, age, and type of surgery and anaesthesia. Surgical patients with ITP had a higher risk of postoperative death (odds ratio (OR) 1·89, 95 per cent confidence interval 1·57 to 2·27), and overall postoperative complications (OR 1·47, 1·39 to 1·56), and increased hospital stay (OR 1·90, 1·80 to 2·01), admission to the intensive care unit (OR 1·73, 1·63 to 1·83) and medical costs (OR 1·89, 1·79 to 1·99). Amount of preoperative platelet and/or red blood cell transfusion, emergency visits and admission to hospital for ITP care were identified as risk factors for adverse postoperative outcomes.

Conclusion

Patients with ITP undergoing surgery are at increased risk of adverse perioperative events, particularly if blood or blood product transfusion are required preoperatively, or the procedure is done as an emergency.

Susceptibility-weighted imaging in patients with pyogenic brain abscesses at 1.5T: characteristics of the abscess capsule

BACKGROUND AND PURPOSE

SWI is a high-resolution 3D, fully velocity-compensated gradient-echo sequence that uses both magnitude and phase data. The purpose of this study was to investigate the phase behavior of the capsule of pyogenic brain abscesses with noncontrast SWI.

MATERIALS AND METHODS

Fourteen patients with pyogenic brain abscesses were studied at 1.5T. In all of the patients, SWI images were obtained and reviewed in addition to conventional MR images. Phase values within the abscess capsule were measured and compared with those from the abscess cavities and contralateral normal white matter using 1-way repeated measures ANOVA with post hoc Bonferroni analysis.

RESULTS

SWI phase images showed mild hypointesity in 6 patients, isointensity in 3 patients, and mixed iso- to mild hypointensity in 5 patients. The means of phase in the cavity, rim of abscesses, and contralateral normal white matter were -7.552 × 10(-3) ± 0.024, -0.105 ± 0.080, and +0.029 ± 0.011 radians, respectively. Post hoc comparisons showed significant differences between any pair of the 3 regions (abscess cavity, rim capsule, and normal white matter) in SWI (all Ps < .005).

CONCLUSIONS

SWI phase imaging shows evidence of paramagnetic substances in agreement with the presence of free radicals from phagocytosis. SWI may provide additional information valuable in the characterization of pyogenic brain abscesses.

Purification and characterization of antifungal δ-dodecalactone from Lactobacillus plantarum AF1 isolated from kimchi

The aim of this study was to purify and identify an antifungal compound from Lactobacillus plantarum AF1, which was isolated from kimchi. The antifungal compound was purified by solid-phase extraction and recycling preparative high-performance liquid chromatography, and its structure was elucidated by using gas chromatography-mass spectrometry (GC-MS). The active compound from L. plantarum AF1 was confirmed to be δ-dodecalactone (molecular weight, 198.3) by comparison of its gas chromatographic retention time with the mass spectrum of standard δ-dodecalactone. The MICs of δ-dodecalactone against various fungi and bacteria ranged from 350 to 6,250 m g/ml. δ-Dodecalactone showed strong antifungal activity against molds Aspergillus flavus, A. fumigatus, A. petrakii, A. ochraceus, A. nidulans, and Penicillium roqueforti. The three tested yeast strains of Candida albicans were more resistant than the molds. Antibacterial activity was evident but less potent than the antifungal activity. δ-Dodecalactone produced pleasurable (fruity) organoleptic characteristics. The results indicate the potential of the δ-dodecalactone produced by L. plantarum AF1 as a biopreservative and flavoring compound, as well as a biosafe remedy for candidiasis.

Capsaicin may induce breast cancer cell death through apoptosis-inducing factor involving mitochondrial dysfunction

The majority of breast cancer patients are resistant to chemotherapy or radiotherapy due to the down-regulation or lack of caspase-3 expression. Capsaicin was found to inhibit cancer cell growth in caspase-3-deficient human breast cancer cells. This study aimed to investigate the growth-inhibitive effect of capsaicin and its mechanisms in human breast cancer cell lines, MCF-7 and BT-20. The results showed that cell viability decreased in a dose-dependent manner in both the caspase-3-deficient and non-deficient cells through inducing cell apoptosis and arresting the cell cycle in the S phase. Capsaicin significantly decreased mitochondria membrane potential, induced the cleavage of PARP-1, and decreased procaspase-7 expression in both cells. Apoptosis-inducing factor (AIF) was distinctly released from mitochondria and translocated into the cytoplasm and nucleus in MCF-7 cells (52.9%), but not in BT-20 cells (2%) after treatment with 200 μM of capsaicin for 24 hours. Capsaicin inhibited breast cancer cell growth through inducing cell apoptosis and cell cycle arrest in the S phase. This apoptotic effect could be induced through the mitochondrial pathway, and PARP-1 subsequently cleaved by activation of caspase-7. The application of capsaicin in clinical therapy could be useful for breast cancer patients.

Forensic Science in Support of Wildlife Conservation Efforts - Developments in Morphological and Chemical Approaches in Taiwan

Parts from animals that are now endangered species (such as bear bile, rhino horn, and tiger bone) have long been important ingredients of traditional Chinese medicine (TCM). Deeply believing in the potency of these ingredients and coupled with substantial gains in wealth of the population in Taiwan in the 1980s, ugly scenarios came to light. Taiwan quickly became the target of investigation pursued by international wildlife conservationists. To provide scientific bases for the government's investigation efforts, morphological, chemical/physical, and genetic methods were developed to characterize TCM products. This review focuses on Taiwanese scientists' efforts on the following topic matters: (a) morphological approach to identify CITES-listed species from the turtle shells traded in the TCM market; (b) chromatographic and spectrophotometric methods for the identification and differentiation of bile products of different animal origins; and (c) gas chromatography-mass spectrometry method for the analysis of deer musk components and alleged musk products.

Determination of microbial diversity in meju, fermented cooked soya beans, using nested PCR-denaturing gradient gel electrophoresis

AIMS

To identify the microbiota in meju, fermented cooked soya beans, that may directly affect the microbial communities of Korean fermented soya bean foods.

METHODS AND RESULTS

Using conventional bacterial 16S rDNA, bacilli-specific 16S rDNA or fungi 18S rDNA-specific primers, PCR products were amplified through a series of PCRs using the DNA extracted from ten meju samples. The amplicons were analysed using denaturing gradient gel electrophoresis (DGGE), which showed that Enterococcus durans was commonly detected in nine of ten meju samples. Bacillus subtilis was shown to be the major strain of bacilli in the samples tested. Based on the DGGE analysis of fungi in meju, we determined that Absidia corymbifera, Aspergillus sp. and Candida rugosa were the main fungi in the tested samples.

CONCLUSIONS

A variety of bacterial and fungal micro-organisms were identified in meju samples, in addition to the micro-organisms already known to be present.

SIGNIFICANCE AND IMPACT OF THE STUDY

This is the first report showing the differences and similarities in the populations of micro-organisms in meju samples using nested PCR-DGGE, a culture-independent method. The results may be applicable to the development of improved meju, in which the indigenous micro-organisms required for fermentation can be standardized.

Purification of a new antifungal compound produced by Lactobacillus plantarum AF1 isolated from kimchi

The aim of this study was to purify and to identify an antifungal compound of Lactobacillus plantarum AF1, which was isolated from kimchi, and to determine if Lb. plantarum AF1 can prevent fungal growth in a particular food model system. The antifungal compound was purified using SPE and recycling prep-HPLC and its structure was elucidated using NMR and ESI-MS. The active compound from Lb. plantarum AF1 is C(12)H(22)N(2)O(2), 3,6-bis(2-methylpropyl)-2,5-piperazinedion has a molecular mass of 226. This is a new antifungal compound produced by lactic acid bacteria (LAB). To investigate the potential application of the antifungal compound to eliminate fungal spoilage in food and feed, soybean was used as a model. White mycelia and dark green spores of Aspergillus flavus ATCC 22546 were observed in the control soybeans after 1 to 2days incubation. However, fungal growth was not observed in the soybeans treated with a 4-fold concentrated supernatant of Lb. plantarum AF1 culture, even after 2days. The end products produced from kimchi LAB, like 3,6-bis(2-methylpropyl)-2,5-piperazinedion identified in this study, may be a promising alternative to chemical preservatives as a potential biopreservative which prevent fungal spoilage and mycotoxin formation in food and feed.

Water-assisted CO(2) laser ablated glass and modified thermal bonding for capillary-driven bio-fluidic application

The glass-based microfluidic chip has widely been applied to the lab-on-a-chip for clotting tests. Here, we have demonstrated a capillary driven flow chip using the water-assisted CO(2) laser ablation for crackless fluidic channels and holes as well as the modified low-temperature glass bonding with assistance of adhesive polymer film at 300 degrees Celsius. Effect of water depth on the laser ablation of glass quality was investigated. The surface hydrophilic property of glass and polymer film was measured by static contact angle method for hydrophilicity examination in comparison with the conventional polydimethylsiloxane (PDMS) material. Both low-viscosity deionized water and high-viscosity whole blood were used for testing the capillary-driving flow behavior. The preliminary coagulation testing in the Y-channel chip was also performed using whole blood and CaCl(2) solution. The water-assisted CO(2) laser processing can cool down glass during ablation for less temperature gradient to eliminate the crack. The modified glass bonding can simplify the conventional complex fabrication procedure of glass chips, such as high-temperature bonding, long consuming time and high cost. Moreover, the developed fluidic glass chip has the merit of hydrophilic behavior conquering the problem of traditional hydrophobic recovery of polymer fluidic chips and shows the ability to drive high-viscosity bio-fluids.

Safrole-Induced Ca2+Mobilization and Cytotoxicity in Human PC3 Prostate Cancer Cells

The effect of the carcinogen safrole on intracellular Ca2+ mobilization and on viability of human PC3 prostate cancer cells was examined. Cytosolic free Ca2+ levels ([Ca2+]i) were measured by using fura-2 as a probe. Safrole at concentrations above 10 microM increased [Ca2+]i in a concentration-dependent manner with an EC50 value of 350 microM. The Ca2+ signal was reduced by more than half after removing extracellular Ca2+ but was unaffected by nifedipine, nicardipine, nimodipine, diltiazem, or verapamil. In Ca2+-free medium, after treatment with 650 microM safrole, 1 microM thapsigargin (an endoplasmic reticulum Ca2+ pump inhibitor) failed to release Ca2+. Neither inhibition of phospholipase C with U73122 nor modulation of protein kinase C activity affected safrole-induced Ca2+ release. Overnight incubation with 0.65-65 microM safrole did not affect cell viability, but incubation with 325-625 microM safrole decreased viability. Collectively, the data suggest that in PC3 cells, safrole induced a [Ca2+]i increase by causing Ca2+ release from the endoplasmic reticulum in a phospholipase C- and protein kinase C-independent fashion, and by inducing Ca2+ influx. Safrole can decrease cell viability in a concentration-dependent manner.

Melittin-induced [Ca2+]i increases and subsequent death in canine renal tubular cells

The effect of melittin on cytosolic free Ca2+ concentration ([Ca2+]i) and viability is largely unknown. This study examined whether melittin alters Ca2+ levels and causes Ca2+-dependent cell death in Madin-Darby canine kidney (MDCK) cells. [Ca2+]i and cell death were measured using the fluorescent dyes fura-2 and WST-1 respectively. Melittin at concentrations above 0.5 μM increased [Ca2+]i in a concentration-dependent manner. The Ca2+ signal was reduced by 75% by removing extracellular Ca2+. The melittin-induced Ca2+ influx was also implicated by melittin-caused Mn2+ influx. After pretreatment with 1 μM thapsigargin (an endoplasmic reticulum Ca2+ pump inhibitor), melittin-induced Ca2+ release was inhibited; and conversely, melittin pretreatment abolished thapsigargin-induced Ca2+ release. At concentrations of 0.5–20 μM, melittin killed cells in a concentration-dependent manner. The cytotoxic effect of 0.5 μM melittin was nearly completely reversed by prechelating cytosolic Ca2+ with BAPTA. Melittin at 0.5–2 μM caused apoptosis as assessed by flow cytometry of propidium iodide staining. Collectively, in MDCK cells, melittin induced a [Ca2+]i rise by causing Ca2+ release from endoplasmic reticulum and Ca2+ influx from extracellular space. Furthermore, melittin can cause Ca2+-dependent cytotoxicity in a concentration-dependent manner.

Fragment-specific fracture fixation and double-column plating of unstable distal radial fractures using AO mini-fragment implants and Kirschner wires

OBJECTIVE

To evaluate the efficacy of AO mini-fragment implants and 1.25-mm Kirschner wires using fragment-specific fracture fixation and double-column plating for displaced or unstable distal radial fractures.

DESIGN

prospective and consecutive.

SETTING

level II trauma hospital.

PARTICIPANTS

28 people with 30 fractures and an average follow-up of 21.1 (range 12-41) months, treated with fragment-specific fracture fixation.

OUTCOME MEASUREMENTS

anatomical assessment using anteroposterior and lateral radiographs, graded according to Sarmiento's modification of Lidstrom's scoring system. CLINICAL OUTCOME ASSESSMENT: DASH and Modified Gartland and Werley scores.

RESULTS

There were 24 excellent and 6 good radiological results. Final mean grip strength was 83% of uninjured side, and mean wrist range of motion was 61 degrees dorsiflexion, 54 degrees palmar flexion, 85 degrees supination and 83 degrees pronation. Gartland and Werley's demerit point system revealed 13 (43%) excellent, 12 (40%) good, 5 (17%) fair and no poor results. The mean DASH score was 18, with a standard deviation of +/-18.

CONCLUSION

This fixation method is a reliable and low-cost alternative with good clinical and anatomical results, particularly useful in open reduction and internal fixation of comminuted intra-articular distal radial fractures.

Identification of the agent from Lactobacillus plantarum KFRI464 that enhances bacteriocin production by Leuconostoc citreum GJ7

AIM

To provide evidence that the production of bacteriocin by lactic acid bacteria can be enhanced by the presence of a bacteriocin-sensitive strain and identify the agent that is responsible for enhancing bacteriocin production.

METHODS AND RESULTS

One bacteriocin-producing lactic acid bacterium was isolated from kimchi. The strain GJ7 was designated as Leuconostoc citreum GJ7 based on Gram staining, biochemical properties, and 16S rRNA gene sequencing. The isolate produced a heat- and pH-stable bacteriocin (kimchicin GJ7), which has antagonistic activity against a broad spectrum of micro-organisms. Tricine-sodium dodecyl sulfate-polyacrylamide gel electrophoresis of purified kimchicin GJ7 showed a single band of molecular weight c. 3500 Da. Cultures of Leuc. citreum GJ7 in the presence of thermally inactivated kimchicin GJ7-sensitive strains, Lactobacillus plantarum KFRI 464, Lactobacillus delbrueckii KFRI 347, or Leuconostoc mesenteroides KCTC 1628, increased bacteriocin production. This inducing factor was characterized and purified from Lact. plantarum KFRI 464, which showed the greatest enhancement of kimchicin GJ7 activity. The inducing factor was purified using a DEAE (diethyl aminoethyl)-Sephacel column and high-performance liquid chromatography, and yielded a single band of c. 6500 Da. N-terminal sequencing of the inducing factor identified 16 amino acids. The N-terminal sequence of the inducing factor was synthesized and examined for the induction of kimchicin GJ7 activity, and was found to induce activity, but at a level about 10% lower than that of the entire molecule.

CONCLUSIONS

The presence of a bacteriocin-sensitive strain, Lact. plantarum KFRI 464, acts as an environmental stimulus to activate the production of kimchicin GJ7 by Leuc. citreum GJ7. The inducing factor from Lact. plantarum KFRI 464 is highly homologous to the 30S ribosomal protein S16 from various micro-organisms. The N-terminal sequence of the inducing factor examined in this study is a very important sequence related to the inducing activity. Nevertheless, the inducing factor may not be part of the ribosomal protein S16 itself.

SIGNIFICANCE AND IMPACT OF THE STUDY

We believe that the present study is the first to identify an agent that is produced by one micro-organism and influences bacteriocin production in another. The bacteriocin-enhancing system described in this study could be effectively used to control the growth of other micro-organisms (sensitive cells) in food systems. Moreover, this enhancement of bacteriocin production can be applied usefully in industrial production of natural food preservatives.