Vinculin phosphorylation impairs vascular endothelial junctions promoting atherosclerosis.

BACKGROUND AND AIMS: Atherosclerosis preferentially develops in arterial branches and curvatures where vascular endothelium is exposed to disturbed flow. In this study, the effects of disturbed flow on the regulation of vascular endothelial phosphoproteins and their contribution to therapeutic application in atherogenesis were elucidated. METHODS: Porcine models, large-scale phosphoproteomics, transgenic mice, and clinical specimens were used to discover novel site-specific phosphorylation alterations induced by disturbed flow in endothelial cells (ECs). RESULTS: A large-scale phosphoproteomics analysis of native endothelium from disturbed (athero-susceptible) vs. pulsatile flow (athero-resistant) regions of porcine aortas led to the identification of a novel atherosclerosis-related phosphoprotein vinculin (VCL) with disturbed flow-induced phosphorylation at serine 721 (VCLS721p). The induction of VCLS721p was mediated by G-protein-coupled receptor kinase 2 (GRK2)S29p and resulted in an inactive form of VCL with a closed conformation, leading to the VE-cadherin/catenin complex disruption to enhance endothelial permeability and atherogenesis. The generation of novel apolipoprotein E-deficient (ApoE-/-) mice overexpressing S721-non-phosphorylatable VCL mutant in ECs confirmed the critical role of VCLS721p in promoting atherosclerosis. The administration of a GRK2 inhibitor to ApoE-/- mice suppressed plaque formation by inhibiting endothelial VCLS721p. Studies on clinical specimens from patients with coronary artery disease (CAD) revealed that endothelial VCLS721p is a critical clinicopathological biomarker for atherosclerosis progression and that serum VCLS721p level is a promising biomarker for CAD diagnosis. CONCLUSIONS: The findings of this study indicate that endothelial VCLS721p is a valuable hemodynamic-based target for clinical assessment and treatment of vascular disorders resulting from atherosclerosis.

Electroconvulsive therapy for obsessive compulsive symptoms in a patient with schizophrenia: a brief report.

Comorbid obsessive-compulsive disorder (OCD) is common among patients with schizophrenia. The role of electroconvulsive therapy (ECT) in the treatment of OCD in schizophrenia is unclear. Herein, we present a 45-year-old man who was diagnosed with schizophrenia along with OCD and received ECT due to relapse of psychosis owing to refractive schizophrenia. Together with psychotic symptoms, obvious symptoms of OCD were observed prior to treatment, including obsessive thoughts, difficulty in starting activities, and repetitive and ritualistic behavior. After 12 sessions of ECT, symptoms of schizophrenia and OCD both improved significantly (Positive and Negative Syndrome Scale [PANSS] score decreased from 95 points to 58 points, and Yale - Brown Obsessive-Compulsive Scale [Y-BOCS] score decreased from 29 points to 11 points). Mild aggravation of OCD symptoms was noted 3 months after ECT treatment (Y-BOCS score increased from 11 points to 17 points) without obvious relapse of psychotic symptoms (PANSS score changed from 58 points to 62 points). In conclusion, ECT could be considered as an alternative therapy for patients with schizophrenia and OCD with limited response to pharmacological treatment.

Bidirectional association between major depressive disorder and dementia: Two population-based cohort studies in Taiwan.

BACKGROUND: Major depressive disorder (MDD) and dementia are both major contributors to the global burden of disease. Despite existing literature on the association between MDD and dementia, there is a lack of a nationwide longitudinal cohort study that considers the competing risk of death. Therefore, this study assessed the bidirectional associations between MDD and dementia over an 11-year period in population-based settings, accounting for death as a competing risk. METHODS: We conducted two population-based retrospective cohort studies in Taiwan. We identified 80,742 patients diagnosed with MDD in 2009-2010 and matched them with patients without MDD by sex, age, and year of diagnosis to assess the relative risk of dementia. We also identified 80,108 patients diagnosed with dementia in 2009-2010 and matched them with patients without dementia by sex, age, and year of diagnosis to assess the relative risk of MDD. All patients were followed until they received a diagnosis of new onset MDD or new onset dementia, their death, or the end of 2019. Cause-specific hazards models were used to estimate adjusted hazard ratios (aHRs). RESULTS: The incidence density (ID) of dementia was higher in patients with MDD than in patients without MDD (7.63 vs. 2.99 per 1000 person-years), with an aHR of 2.71 (95% confidence interval [CI]: 2.55-2.88). The ID of MDD was higher in patients with dementia than in patients without dementia (12.77 vs. 4.69 per 1000 person-years), with an aHR of 2.47 (95% CI: 2.35-2.59). CONCLUSIONS: This population-based study found a bidirectional association between MDD and dementia. Our findings suggest the need to identify dementia in patients with MDD and vice versa.

Ultrafast Polymer Dynamics through a Nanopore.

Ultrathin nanopore sensors allow single-molecule and polymer measurements at sub-microsecond time resolution enabled by high current signals (∼10-30 nA). We demonstrate for the first time the experimental probing of the ultrafast translocation and folded dynamics of double-stranded DNA (dsDNA) through a nanopore at 10 MHz bandwidth with acquisition of data points per 25 ns (150 MB/s). By introducing a rigorous algorithm, we are able to accurately identify each current level present within translocation events and elucidate the dynamic folded and unfolded behaviors. The remarkable sensitivity of this system reveals distortions of short-lived folded states at a lower bandwidth. This work revisits probing of dsDNA as a model polymer and develops broadly applicable methods. The combined improvements in sensor signals, instrumentation, and large data analysis methods uncover biomolecular dynamics at unprecedentedly small time scales.

Protein-enabled detection of ibuprofen and sulfamethoxazole using solid-state nanopores.

Enabled by proteins, we present an all-electrical method for rapid detection of small pharmaceuticals (ibuprofen and sulfamethoxazole [SMZ]) in aqueous media using silicon nitride pores. Specifically, we use carrier proteins, bovine serum albumin (BSA), and take advantage of their interactions with two small drug molecules to form BSA-drug complexes which can be detected by nm-diameter pores, thereby confirming the presence of small pharmaceuticals. We demonstrate detection of ibuprofen and SMZ at concentrations down to 100 nM (∼21 µg/L) and 48.5 nM (12 µg/L), respectively. We observe changes in electrical signal characteristics (reflected in event durations, rates, current magnitudes, and estimated particle diameters) of BSA-drug complexes compared to BSA-only, and differences between these two small pharmaceuticals, possibly paving a path toward developing selective sensors by identifying "electrical fingerprints" of these molecules in the future. These distinct electrical signals are likely a combined result of diffusion, electrophoretic and electroosmotic effects, interactions between the pore and particles, which depend on pore diameters, pH, and the resulting surface charges. The use of single-molecule-counting nanopores allows sensing of small pharmaceuticals, studies of protein conformational changes, and may aid in efforts to evaluate the impact of small drug molecules on aquatic and human life.

Efficacy of a temporary CentriMag ventricular assist device in acute fulminant myocarditis patients revived with extracorporeal cardiopulmonary resuscitation.

BACKGROUND: Although extracorporeal life support (ECLS) can provide emergency systemic perfusion for acute fulminant myocarditis (AFM), the mortality rate remains extremely high, especially in those undergoing extracorporeal cardiopulmonary resuscitation (ECPR). Temporary ventricular assist device (VAD) can provide a more physiological blood flow direction and better subsequent organ perfusion than ECLS. We investigated temporary VAD efficacy in ECPR-revived AFM patients. METHODS: During January 2012-May 2019, we retrospectively recruited 22 AFM patients with hemodynamic collapse and ECPR; 11 underwent ECLS only and 11 underwent additional VAD support after ECLS. Systemic perfusion was compared via laboratory biochemistry at post-ECPR days 2 (D2) and 4 (D4). Consciousness and cardiac function were assessed through the Glasgow Coma Scale (GCS) and echocardiography, respectively. All major complications and causes of mortality were recorded; 30-day survival was analyzed and risk factors were predicted. RESULTS: The VAD group had significantly better hemodynamic improvement; more inotropes being tapered at D2 and D4; better data representative of systemic perfusion, including albumin, pH, bicarbonate, and lactate levels at D4; and better 30-day survival (72.7% vs. 27.2%, p = 0.033). The causes of mortality included central failure, multiple organ failure, and bacteremia with sepsis. The risk factors included lethal dysrhythmia before ECLS, GCS <5 at D2, and elevated cardiac enzymes at D4. CONCLUSION: For AFM patients, temporary VAD could provide better systemic perfusion and organ preservation than ECLS. VAD had better survival, including improved recovery and successful transplantation. Hence, temporary VAD should be considered if ECLS cannot revive the sustained cardiogenic shock.

Investigation of entrance effects on particle electrophoretic behavior near a nanopore for resistive pulse sensing.

Resistive pulse sensing using solid-state nanopores provides a unique platform for detecting the structure and concentration of molecules of different types of analytes in an electrolyte solution. The capture of an entity into a nanopore is subject not only to the electrostatic force but also the effect of electroosmotic flow originating from the charged nanopore surface. In this study, we theoretically analyze spherical particle electrophoretic behavior near the entrance of a charged nanopore. By investigating the effects of pore size, particle-pore distance, and salt concentration on particle velocity, we summarize dominant mechanisms governing particle behavior for a range of conditions. In the literature, the Helmholtz-Smoluchowski equation is often adopted to evaluate particle translocation by considering the zeta potential difference between the particle and nanopore surfaces. We point out that, due to the difference of the electric field inside and outside the nanopore and the influence from the existence of the particle itself, the zeta potential of the particle, however, needs to be at least 30% higher than that of the nanopore to allow the particle to enter into the nanopore when its velocity is close to zero. Accordingly, we summarize the effective salt concentrations that enable successful particle capture and detection for different pore sizes, offering direct guidance for nanopore applications.

Aldehyde dehydrogenase 2 protects against abdominal aortic aneurysm formation by reducing reactive oxygen species, vascular inflammation, and apoptosis of vascular smooth muscle cells.

Mitochondrial aldehyde dehydrogenase 2 (ALDH2) is an enzyme that detoxifies aldehydes by converting them to carboxylic acids. ALDH2 deficiency is known to increase oxidative stress. Increased oxidative stress plays a pivotal role in abdominal aortic aneurysm (AAA) pathogenesis. Reactive oxygen species (ROS) promote degradation of the extracellular matrix (ECM) and vascular smooth muscle cell (VSMC) apoptosis. Reducing oxidative stress by an ALDH2 activator could have therapeutic potential for limiting AAA development. We hypothesized that ALDH2 deficiency could increase the risk for AAA by decreasing ROS elimination and that an ALDH2 activator could provide an alternative option for AAA treatment. The National Center for Biotechnology (NCBI) Gene Expression Omnibus (GEO) database was used. Human aortic smooth muscle cells (HASMCs) were used for the in vitro experiments. Gene-targeted ALDH2*2 KI knock-in mice on a C57BL/6J background and apolipoprotein E knockout (ApoE KO) mice were obtained. An animal model of AAA was constructed using osmotic minipumps to deliver 1000 ng/kg/min angiotensin II (AngII) for 28 days. Patients with AAA had significantly lower ALDH2 expression levels than normal subjects. ALDH2*2 KI mice were susceptible to AngII administration, exhibiting significantly increased AAA incidence rates and increased aortic diameters. Alda-1, an ALDH2 activator, reduced AngII-induced ROS production, NF-kB activation, and apoptosis in HASMCs. Alda-1 attenuated AngII-induced aneurysm formation and decreased aortic expansion in ApoE KO mice. We concluded that ALDH2 deficiency is associated with the development of AAAs in humans and a murine disease model. ALDH2 deficiency increases susceptibility to AngII-induced AAA formation by attenuating anti-ROS effects and increasing VSMC apoptosis and vascular inflammation. Alda-1 was shown to attenuate the progression of experimental AAA in a murine model.

Engineering adjustable two-pore devices for parallel ion transport and DNA translocations.

We report ionic current and double-stranded DNA (dsDNA) translocation measurements through solid-state membranes with two TEM-drilled ∼3-nm diameter silicon nitride nanopores in parallel. Nanopores are fabricated with similar diameters but varying in effective thicknesses (from 2.6 to 10 nm) ranging from a thickness ratio of 1:1 to 1:3.75, producing distinct conductance levels. This was made possible by locally thinning the silicon nitride membrane to shape the desired topography with nanoscale precision using electron beam lithography (EBL). Two nanopores are engineered and subsequently drilled in either the EBL-thinned or the surrounding membrane region. By designing the interpore separation a few orders of magnitude larger than the pore diameter (e.g., ∼900 vs 3 nm), we show analytically, numerically, and experimentally that the total conductance of the two pores is the sum of the individual pore conductances. For a two-pore device with similar diameters yet thicknesses in the ratio of 1:3, a ratio of ∼1:2.2 in open-pore conductances and translocation current signals is expected, as if they were measured independently. Introducing dsDNA as analytes to both pores simultaneously, we detect more than 12 000 events within 2 min and trace them back with a high likelihood to which pore the dsDNA translocated through. Moreover, we monitor translocations through one active pore only when the other pore is clogged. This work demonstrates how two-pore devices can fundamentally open up a parallel translocation reading system for solid-state nanopores. This approach could be creatively generalized to more pores with desired parameters given a sufficient signal-to-noise ratio.

Effectiveness of hospital emergency department regionalization and categorization policy on appropriate patient emergency care use: a nationwide observational study in Taiwan.

BACKGROUND: Emergency department (ED) overcrowding is a health services issue worldwide. Modern health policy emphasizes appropriate health services utilization. However, the relationship between accessibility, capability, and appropriateness of ED use is unknown. Thus, this study aimed to examine the effect of hospital ED regionalization policy and categorization of hospital emergency capability policy (categorization policy) on patient-appropriate ED use. METHODS: Taiwan implemented a nationwide three-tiered hospital ED regionalization and categorization of hospital emergency capability policies in 2007 and 2009, respectively. We conducted a retrospective observational study on the effect of emergency care policy intervention on patient visit. Between 2005 and 2011, the Taiwan National Health Insurance Research Database recorded 1,835,860 ED visits from 1 million random samples. ED visits were categorized using the Yang-Ming modified New York University-ED algorithm. A time series analysis was performed to examine the change in appropriate ED use rate after policy implementation. RESULTS: From 2005 to 2011, total ED visits increased by 10.7%. After policy implementation, the average appropriate ED visit rate was 66.9%. The intervention had no significant effect on the trend of appropriate ED visit rate. CONCLUSIONS: Although regionalization and categorization policies did increase emergency care accessibility, it had no significant effect on patient-appropriate ED use. Further research is required to improve data-driven policymaking.

Effects of Levosimendan on Systemic Perfusion in Patients with Low Interagency Registry for Mechanically Assisted Circulatory Support (INTERMACS) Score: Experience from a Single Center in Taiwan.

BACKGROUND: Patients with cardiogenic shock have a high risk of mortality. Intravenous levosimendan can provide pharmacologic inotrope support. OBJECTIVES: We aimed to investigate the effect of levosimendan in patients with extremely severe cardiogenic shock and low Interagency Registry for Mechanically Assisted Circulatory Support (INTERMACS) score with or without mechanical circulatory support. METHODS: From January 2017 to May 2019, 24 patients with INTERMACS 1-4 were enrolled in this retrospective study. All patients had systemic malperfusion and were treated with levosimendan. Biochemistry data related to systemic perfusion were recorded and compared before and at 24 and 72 hours after levosimendan administration. Echocardiography and Kansas City Cardiomyopathy Questionnaire (KCCQ) were completed 2 months later to assess left ventricular ejection fraction (LVEF) and quality of life (QoL), respectively. RESULTS: Arterial pressure and heart rate did not significantly differ before and after levosimendan administration. Atrial fibrillation and ventricular premature complex increased without significance. The dose of inotropes could be significantly tapered down. There were no significant differences in blood urea nitrogen, creatinine, and lactate levels. Urine output significantly increased (p = 0.018), and liver-related enzymes improved but without significance. B-type natriuretic peptide significantly decreased (p = 0.007) at 24 hours after levosimendan administration. Echocardiography showed significantly improved LVEF 2 months later (22.43 ± 8.13% to 35.87 ± 13.4%, p = 0.001). KCCQ showed significantly improved physical activity and greater relief of symptoms (p = 0.003). The survival-to-discharge rate was 75%. CONCLUSIONS: We observed a decrease in B-type natriuretic peptide, better urine output, and alleviated hepatic injury in the levosimendan group. Most patients who survived without transplantation had significantly improved LVEF and better QoL after levosimendan administration.

The effect of Sirt1 deficiency on Ca2+ and Na+ regulation in mouse ventricular myocytes.

This study addressed the hypothesis that cardiac Sirtuin 1 (Sirt1) deficiency alters cardiomyocyte Ca2+ and Na+ regulation, leading to cardiac dysfunction and arrhythmogenesis. We used mice with cardiac-specific Sirt1 knockout (Sirt1-/- ). Sirt1flox/flox mice were served as control. Sirt1-/- mice showed impaired cardiac ejection fraction with increased ventricular spontaneous activity and burst firing compared with those in control mice. The arrhythmic events were suppressed by KN93 and ranolazine. Reduction in Ca2+ transient amplitudes and sarcoplasmic reticulum (SR) Ca2+ stores, and increased SR Ca2+ leak were shown in the Sirt1-/- mice. Electrophysiological measurements were performed using patch-clamp method. While L-type Ca2+ current (ICa, L ) was smaller in Sirt1-/- myocytes, reverse-mode Na+ /Ca2+ exchanger (NCX) current was larger compared with those in control myocytes. Late Na+ current (INa, L ) was enhanced in the Sirt1-/- mice, alongside with elevated cytosolic Na+ level. Increased cytosolic and mitochondrial reactive oxygen species (ROS) were shown in Sirt1-/- mice. Sirt1-/- cardiomyocytes showed down-regulation of L-type Ca2+ channel α1c subunit (Cav1.2) and sarcoplasmic/endoplasmic reticulum Ca2+  ATPase 2a (SERCA2a), but up-regulation of Ca2+ /calmodulin-dependent protein kinase II and NCX. In conclusions, these findings suggest that deficiency of Sirt1 impairs the regulation of intracellular Ca2+ and Na+ in cardiomyocytes, thereby provoking cardiac dysfunction and arrhythmogenesis.

Cardiac calcium dysregulation in mice with chronic kidney disease.

Cardiovascular complications are leading causes of morbidity and mortality in patients with chronic kidney disease (CKD). CKD significantly affects cardiac calcium (Ca2+ ) regulation, but the underlying mechanisms are not clear. The present study investigated the modulation of Ca2+ homeostasis in CKD mice. Echocardiography revealed impaired fractional shortening (FS) and stroke volume (SV) in CKD mice. Electrocardiography showed that CKD mice exhibited longer QT interval, corrected QT (QTc) prolongation, faster spontaneous activities, shorter action potential duration (APD) and increased ventricle arrhythmogenesis, and ranolazine (10 µmol/L) blocked these effects. Conventional microelectrodes and the Fluo-3 fluorometric ratio techniques indicated that CKD ventricular cardiomyocytes exhibited higher Ca2+ decay time, Ca2+ sparks, and Ca2+ leakage but lower [Ca2+ ]i transients and sarcoplasmic reticulum Ca2+ contents. The CaMKII inhibitor KN93 and ranolazine (RAN; late sodium current inhibitor) reversed the deterioration in Ca2+ handling. Western blots revealed that CKD ventricles exhibited higher phosphorylated RyR2 and CaMKII and reduced phosphorylated SERCA2 and SERCA2 and the ratio of PLB-Thr17 to PLB. In conclusions, the modulation of CaMKII, PLB and late Na+ current in CKD significantly altered cardiac Ca2+ regulation and electrophysiological characteristics. These findings may apply on future clinical therapies.

Charge Inversion and Calcium Gating in Mixtures of Ions in Nanopores.

Calcium ions play important roles in many physiological processes, yet their concentration is much lower than the concentrations of potassium and sodium ions. The selectivity of calcium channels is often probed in mixtures of calcium and a monovalent salt, e.g., KCl or NaCl, prepared such that the concentration of cations is kept constant with the mole fraction of calcium varying from 0 and 1. In biological channels, even sub-mM concentration of calcium can modulate the channels' transport characteristics; this effect is often explained via the existence of high affinity Ca2+ binding sites on the channel walls. Inspired by properties of biological calcium-selective channels, we prepared a set of nanopores with tunable opening diameters that exhibited a similar response to the presence of calcium ions as biochannels. Nanopores in 15 nm thick silicon nitride films were drilled using focused ion beam and e-beam in a transmission electron microscope and subsequently rendered negatively charged through silanization. We found that nanopores with diameters smaller than 20 nm were blocked by calcium ions such that the ion currents in mixtures of KCl and CaCl2 and in CaCl2 were even ten times smaller than the ion currents in KCl solution. The ion current blockage was explained by the effect of local charge inversion where accumulated calcium ions switch the effective surface charge from negative to positive. The modulation of surface charge with calcium leads to concentration and voltage dependent local charge density and ion current. The combined experimental and modeling results provide a link between calcium ion-induced changes in surface charge properties and resulting ionic transport.

Association between surgical repair of aortic aneurysms and the diagnosis of intracranial aneurysms.

OBJECTIVE: Aortic aneurysms (AAs) and intracranial aneurysms (IAs) share several clinical risk factors, a genetic predisposition, and molecular signaling pathways. Nonetheless, associations between IAs and AAs remain to be thoroughly validated in large-scale studies. In addition, no effective medical therapies exist for unruptured IAs or AAs. METHODS: Data for this nationwide, population-based, retrospective, cohort study described herein were obtained from the National Health Insurance Research Database in Taiwan. The study outcomes assessed were (1) the cumulative incidence of IAs, which was compared between AA and patients without an AA and (2) the cumulative incidence of IAs in patients with AAs during the 13-year follow-up period, which was further compared among those who underwent open surgical repair (OSR), endovascular aneurysm repair or nonsurgical treatment (NST). RESULTS: Our analyses included 20,280 patients with an AA and 20,280 propensity score-matched patients without an AA. Compared with the patients without an AA, patients with AA exhibited a significantly increased risk of an IA diagnosis (adjusted hazard ratio [HR], 3.395; P < .001). Furthermore, 6308 patients with AAs were treated with surgical intervention and another 6308 propensity score-matched patients with AAs were not. Patients with an AA who underwent OSR had a significantly lower risk of being diagnosed with an IA than patients with an AA who underwent endovascular aneurysm repair or NST (adjusted HR, 0.491 [P < .001] and adjusted HR, 0.473 [P < .001], respectively). CONCLUSIONS: We demonstrated an association between IAs and AAs, even after adjusting for several comorbidities. We also found that OSR was associated with fewer recognized IAs than NST.

Choosing and Doing wisely: triage level I resuscitation a possible new field for starting palliative care and avoiding low-value care - a nationwide matched-pair retrospective cohort study in Taiwan.

BACKGROUND: The association between palliative care and life-sustaining treatment following emergency department (ED) resuscitation is unclear. This study aims to analyze the usage of palliative care and life-sustaining treatments among ED triage level I resuscitation patients based on a nationally representative sample of patients in Taiwan. METHODS: A matched-pair retrospective cohort study was conducted to examine the association between palliative care and outcome variables using multivariate logistic regression and Kaplan-Meier survival analyses. Between 2009 and 2013, 336 ED triage level I resuscitation patients received palliative care services (palliative care group) under a universal health insurance scheme. Retrospective cohort matching was performed with those who received standard care at a ratio of 1:4 (usual care group). Outcome variables included the number of visits to emergency and outpatient departments, hospitalization duration, total medical expenses, utilization of life-sustaining treatments, and duration of survival following ED triage level I resuscitation. RESULTS: The mean survival duration following level I resuscitation was less than 1 year. Palliative care was administered to 15% of the resuscitation cohort. The palliative care group received significantly less life-sustaining treatment than did the usual care group. CONCLUSION: Among patients who underwent level I resuscitation, palliative care was inversely correlated with the scope of life-sustaining treatments. Furthermore, triage level I resuscitation status may present a possible new field for starting palliative care intervention and reducing low-value care.

Rectification of Concentration Polarization in Mesopores Leads To High Conductance Ionic Diodes and High Performance Osmotic Power.

Nanopores exhibit a set of interesting transport properties that stem from interactions of the passing ions and molecules with the pore walls. Nanopores are used, for example, as ionic diodes and transistors, biosensors, and osmotic power generators. Using nanopores is however disadvantaged by their high resistance, small switching currents in nA range, low power generated, and signals that can be difficult to distinguish from the background. Here, we present a mesopore with ionic conductance reaching µS that rectifies ion current in salt concentrations as high as 1 M. The mesopore is conically shaped, and its region close to the narrow opening is filled with high molecular weight poly-l-lysine. To elucidate the underlying mechanism of ion current rectification (ICR), a continuum model based on a set of Poisson-Nernst-Planck and Stokes-Brinkman equations was adopted. The results revealed that embedding the polyelectrolyte in a conical pore leads to rectification of the effect of concentration polarization (CP) that is induced by the polyelectrolyte, and observed as voltage polarity-dependent modulations of ionic concentrations in the pore, and consequently ICR. Our work reveals the link between ICR and CP, significantly extending the knowledge of how charged polyelectrolytes modulate ion transport on nano- and mesoscales. The osmotic power application is also demonstrated with the developed polyelectrolyte-filled mesopores, which enable a power of up to ∼120 pW from one pore, which is much higher than the reported values using single nanoscale pores.

Electrokinetic ion transport in an asymmetric double-gated nanochannel with a pH-tunable zwitterionic surface.

Bioinspired, artificial functional nanochannels for intelligent molecular and ionic transport control have versatile potential applications in nanofluidics, energy conversion, and controlled drug release. To simulate the gating and rectification functions of biological ion channels, we model the electrokinetic ion transport phenomenon in an asymmetric double-gated nanochannel having a pH-regulated, zwitterionic surface. Taking account of the effect of electroosmotic flow (EOF), the conductance of the nanochannel and its ion current rectification (ICR) behavior are investigated and the associated mechanisms interpreted. In particular, the influences of the solution pH, the bulk salt concentration, and the base opening radius and the surface curvature of the nanochannel on these behaviors are examined. We show that through adjusting the base opening radius and the surface curvature of a nanochannel, its ICR behavior can be tuned effectively. In addition to proposing underlying mechanisms for the phenomena observed, the results gathered in this study also provide necessary information for designing relevant devices.

Successful Thoracic Endovascular Aortic Repair in Ortner's Syndrome.

We present the case of an 89-year-old man with 3-month history of hoarseness and no other significant clinical manifestations. Flexible laryngoscopy revealed a paralyzed left vocal cord, and contrast-enhanced computed tomography showed a thoracic dissecting aortic aneurysm of the distal aortic arch and proximal descending aorta. The aortic aneurysm was repaired through implantation of an endovascular stent graft, and the patient was discharged uneventfully after a week. The false lumen was completely thrombosed, and the patient had a partial resolution of hoarseness at the 1-year follow-up.

Inequality in outpatient resource utilization among older adults during the 2007-2008 financial crisis: findings from Taiwan.

BACKGROUND: Equity in medical resource utilization is a crucial concern in countries with national health insurance systems. From the perspective of an active aging framework, public health insurance is one of the pillars of economic security, as suggested by the World Bank, to achieve the goal of social security for older adults. This study thus sought to quantify income-related inequality in national health insurance systems, especially during the global economic crisis of 2007-2008. METHODS: By employing the Taiwan National Health Interview Surveys (2005 and 2009) datasets, we analyzed the socioeconomic inequality of outpatient service utilization for older Taiwanese adults during the financial crisis of 2007-2008. We used corrected concentration indices (CCIs) to examine inequalities over time. Furthermore, we decomposed socioeconomic inequalities to reveal the contributions of determinant factors. The dependent variables related to whether participants had used outpatient services in the previous month, and the independent factors included individual's needs, enabling, predisposing, and environmental factors proposed by Andersen model. RESULTS: The sample consisted of 2415 observations in 2005 and 2554 observations in 2009. The income-related health care inequality was minor from pro-rich to pro-poor across the study duration, although the difference was insignificant (women: from a concentration index [CI] of 0.0256 in 2005 to a CI of - 0.0098 in 2009; men: from a CI of 0.0379 in 2005 to a CI of 0.0310 in 2009). We used a probit model to analyze the effect of explanatory factors on outpatient resource utilization by men and women. After other factors were controlled for, we found that that the income variable had a positive and significant effect on outpatient service utilization in 2009 and the absolute contribution of income to inequality notably increased from 0.0480 in 2005 to 0.3247 in 2009 for older women. CONCLUSIONS: In conclusion, Taiwan's National Health Insurance system guarantees the accessibility of health care services to older adults, but slight income-related inequality was maintained in the outpatient resource utilization of women during the 2007-2008 financial crisis. Close attention should be paid to the vulnerability of women during times of economic insecurity.