The differential impact of Type D personality on the prognosis of patients with stable coronary artery disease.

OBJECTIVE: This study investigated the association between Type D personality and prognoses in stable coronary artery disease (CAD) patients by mode of endpoints, age, and methodological debates to explain substantial heterogeneity among Type D studies. DESIGN: The prospective study was designed to recruit 590 stable CAD patients in Taiwan. Main outcome measures: Demographic and clinical characteristics, and the 14-item Type D scale-Taiwanese version were recorded at discharge. RESULTS: Hierarchical logistic regression analyses showed, regardless of the methodological debates, Type D personality was significantly associated with MACEs though not non-cardiac outcomes in stable CAD patients after adjusting for possible confounders. Furthermore, Type D personality was especially associated with MACEs in stable CAD patients with younger age (<65 y), rather than older age (≥65 y). Subgroup analysis also showed the adverse effect of Type D personality on MACEs was larger among males, those living in the rural region, those with PTCA or stent, those with heart failure, hypertension, diabetes, and those who were smokers. CONCLUSIONS: Regardless of whether the methodological debate is dichotomous or continuous, Type D personality was significantly associated with MACEs in stable CAD patients, some of whom had younger age, were males, smokers, or had comorbidities.

Genetic and Epigenetic Host-Virus Network to Investigate Pathogenesis and Identify Biomarkers for Drug Repurposing of Human Respiratory Syncytial Virus via Real-World Two-Side RNA-Seq Data: Systems Biology and Deep-Learning Approach.

Human respiratory syncytial virus (hRSV) affects more than 33 million people each year, but there are currently no effective drugs or vaccines approved. In this study, we first constructed a candidate host-pathogen interspecies genome-wide genetic and epigenetic network (HPI-GWGEN) via big-data mining. Then, we employed reversed dynamic methods via two-side host-pathogen RNA-seq time-profile data to prune false positives in candidate HPI-GWGEN to obtain the real HPI-GWGEN. With the aid of principal-network projection and the annotation of KEGG pathways, we can extract core signaling pathways during hRSV infection to investigate the pathogenic mechanism of hRSV infection and select the corresponding significant biomarkers as drug targets, i.e., TRAF6, STAT3, IRF3, TYK2, and MAVS. Finally, in order to discover potential molecular drugs, we trained a DNN-based DTI model by drug-target interaction databases to predict candidate molecular drugs for these drug targets. After screening these candidate molecular drugs by three drug design specifications simultaneously, i.e., regulation ability, sensitivity, and toxicity. We finally selected acitretin, RS-67333, and phenformin to combine as a potential multimolecule drug for the therapeutic treatment of hRSV infection.

The association between hydroxychloroquine use and future development of systemic lupus erythematosus in patients with primary Sjögren's syndrome.

AIM: Hydroxychloroquine (HCQ), commonly used to treat patients with primary Sjögren's syndrome (pSS), has been shown to delay the development of systemic lupus erythematosus (SLE). This study aimed to explore the association between HCQ use and future development of SLE in pSS patients based on a nationwide nested case-control study. METHOD: Based on the National Health Insurance Research Database of Taiwan, those patients who were diagnosed with SLE at least 1 year after the diagnosis of pSS were identified as cases. Matched controls were randomly selected from pSS patients without a later diagnosis of SLE in a 1:10 ratio. The odds ratios (ORs) of HCQ exposure between cases and controls were analyzed by unconditional logistic regression after adjustment for age. RESULTS: A cohort of 11 772 pSS patients were extracted from the database during the period from January 1, 2000 to December 31, 2010. A total of 111 (0.9%) pSS patients developed SLE during the follow-up period. Most (79%) of them developed SLE within 5 years after the diagnosis of pSS. There was no significant difference in the odds of HCQ exposure between cases and controls, with an adjusted OR of 2.43 (95% CI: 0.73-8.05). Neither did we observe a significant difference in the odds of exposure to a higher average dose of HCQ (≥100 mg/d vs non-exposed) between cases and controls in the sensitivity analysis. CONCLUSION: Nearly 1% of pSS patients may develop SLE. HCQ use in pSS patients was not associated with a lower possibility of the future development of SLE.

A Comparative Study on Analysis of Ginsenosides in American Ginseng Root Residue by HPLC-DAD-ESI-MS and UPLC-HRMS-MS/MS.

Ginseng (Panax quinquefolius), a popular herbal and nutritional supplement consumed worldwide, has been demonstrated to possess vital biological activities, which can be attributed to the presence of ginsenosides. However, the presence of ginsenosides in ginseng root residue, a by-product obtained during processing of ginseng beverage, remains unexplored. The objectives of this study were to develop a high-performance liquid chromatography-photodiode array detection-mass spectrometry (HPLC-DAD-ESI-MS) and an ultra-high-performance-liquid-chromatography-tandem mass spectrometry (UPLC-HRMS-MS/MS) method for the comparison of ginsenoside analysis in ginseng root residue. Results showed that by employing a Supelco Ascentis Express C18 column (150 × 4.6 mm ID, particle size 2.7 µm) and a gradient mobile phase of deionized water and acetonitrile with a flow rate at 1 mL/min and detection at 205 nm, a total of 10 ginsenosides, including internal standard saikosaponin A, were separated within 18 min and detected by HPLC-DAD-ESI-MS. Whereas with UPLC-HRMS-MS/MS, all the 10 ginsenosides were separated within six minutes by using an Acquity UPLC BEH C18 column (50 × 2.1 mm ID, particle size 1.7 µm, 130 Å) and a gradient mobile phase of ammonium acetate and acetonitrile with column temperature at 50 °C, flow rate at 0.4 mL/min and detection by selected reaction monitoring (SRM) mode. High accuracy and precision was shown, with limit of quantitation (LOQ) ranging from 0.2−1.9 µg/g for HPLC-DAD-ESI-MS and 0.269−6.640 ng/g for UPLC-HRMS-MS/MS. The contents of nine ginsenosides in the ginseng root residue ranged from

Immunogenicity, Effectiveness, and Safety of COVID-19 Vaccines in Rheumatic Patients: An Updated Systematic Review and Meta-Analysis.

BACKGROUND: Vaccination is one of the most important measures worldwide to halt the spread of the corona virus disease 2019 (COVID-19). However, the efficacy and safety of these vaccines in rheumatic patients are not well explored. Therefore, we conducted a systematic review and meta-analysis. METHODS: We performed a literature search of the PubMed and EMBASE databases on 17 November 2021. Forty-seven studies relevant to the immunogenicity, efficacy/effectiveness, and safety of COVID-19 vaccines were selected. RESULTS: Our results demonstrated that COVID-19 vaccination is effective in protecting rheumatic patients from severe illness caused by the virus. Both the humoral and cellular immunogenicity of vaccines were impaired in rheumatic patients, which were greatly enhanced after the second vaccine dose. Receiving anti-CD20 therapy was associated with impaired humoral immunogenicity. Adverse events due to COVID-19 vaccines in rheumatic patients were similar to those in healthy controls, except for an increased incidence of arthralgia. The incidence of disease flares after COVID-19 vaccination was low. CONCLUSION: Our systematic review indicated the importance of full vaccination in rheumatic patients. Withholding anti-CD20 therapy was found to be potentially beneficial for the immunogenicity. Furthermore, the vaccines were found to be safe in general. Despite significant heterogeneity between studies, we recommend that rheumatic patients receive these vaccines amidst the global pandemic.

Insights into aerosol chemical composition and optical properties at Lulin Atmospheric Background Station (2862 m asl) during two contrasting seasons.

Continental outflows from peninsular Southeast Asia and East Asia dominate the widespread dispersal of air pollutants over subtropical western North Pacific during spring and autumn, respectively. This study analyses the chemical composition and optical properties of PM10 aerosols during autumn and spring at a representative high-altitude site, viz., Lulin Atmospheric Background Station (23.47°N, 120.87°E; 2862 m a.s.l.), Taiwan. PM10 mass was reconstructed and the contributions of major chemical components were also delineated. Aerosol scattering (σsp) and absorption (σap) coefficients were regressed on mass densities of major chemical components by assuming external mixing between them, and the site-specific mass scattering efficiency (MSE) and mass absorption efficiency (MAE) of individual components for dry conditions were determined. NH4NO3 exhibited the highest MSE among all components during both seasons (8.40 and 12.58 m2 g-1 at 550 nm in autumn and spring, respectively). (NH4)2SO4 and organic matter (OM) accounted for the highest σsp during autumn (51%) and spring (50%), respectively. Mean MAE (mean contribution to σap) of elemental carbon (EC) at 550 nm was 2.51 m2 g-1 (36%) and 7.30 m2 g-1 (61%) in autumn and spring, respectively. Likewise, the mean MAE (mean contribution to σap) of organic carbon (OC) at 550 nm was 0.84 m2 g-1 (64%) and 0.83 m2 g-1 (39%) in autumn and spring, respectively. However, a classification matrix, based on scattering Ångström exponent, absorption Ångström exponent, and single scattering albedo (ω), demonstrated that the composite absorbing aerosols were EC-dominated (with weak absorption; ω = 0.91-0.95) in autumn and a combination of EC-dominated and EC/OC mixture (with moderate absorption; ω = 0.85-0.92) in spring. This study demonstrates a strong link between chemical composition and optical properties of aerosol and provides essential information for model simulations to assess the imbalance in regional radiation budget with better accuracy over the western North Pacific.

All-Vacuum-Deposited Perovskite X-ray Detector with a Record-High Self-Powered Sensitivity of 1.2 C Gy-1 cm-3.

Highly sensitive X-ray detection is crucial in, for example, medical imaging and secure inspection. Halide perovskite X-ray detectors are promising candidates for detecting highly energetic radiation. In this report, we describe vacuum-deposited Cs-based perovskite X-ray detectors possessing a p-i-n architecture. Because of the built-in potential of the p-i-n structure, these perovskite X-ray detectors were capable of efficient charge collection and displayed an exceptionally high X-ray sensitivity (1.2 C Gyair-1 cm-3) under self-powered, zero-bias conditions. We ascribe the outstanding X-ray sensitivity of the vacuum-deposited CsPbI2Br devices to their prominent charge carrier mobility. Moreover, these devices functioned with a lowest detection limit of 25.69 nGyair s-1 and possessed excellent stability after exposure to over 3000 times the total dose of a chest X-ray image. For comparison, we also prepared traditional spin-coated CH3NH3-based perovskite devices having a similar device architecture. Their volume sensitivity was only one-fifth of that of the vacuum-deposited CsPbI2Br devices. Thus, all-vacuum deposition appears to be a new strategy for developing perovskite X-ray detectors; with a high practical deposition rate, a balance can be reached between the thickness of the absorbing layer and the fabrication time.

The impact of sources of perceived social support on readmissions in patients with heart failure.

BACKGROUND: Lower levels of perceived social support have been known as an independent predictor of hospital readmissions in patients with heart failure (HF). However, the impact of sources of perceived social support on readmissions remain unexplored. PURPOSE: The main purpose of this study was to investigate and compare the relative importance of social support from significant other, family, and friends on all-cause readmission and cardiac readmission in patients with HF. METHODS: The prospective cohort study was used to recruit a total of 299 patients with HF in Taiwan between May 2012 and December 2014. Demographic and clinical characteristics, Multidimensional Perceived Social Support Scale (MPSSS), and 18-month follow-up readmissions were recorded during the hospital stay. Univariate and multivariate logistic regressions were constructed to determine the impact of levels and sources of perceived social support with all-cause readmission and cardiac readmission. RESULTS: A total of 158 patients (52.8%) and 118 patients (39.5%), respectively, had all-cause readmission and cardiac readmissions within 18 months. Multivariate logistic regression yielded inverse associations between levels of perceived social support and readmissions by 18-months. Importantly, social support from significant other was significantly associated with a lower risk of readmissions, both of all-cause readmission and cardiac readmission, in patients with HF, even after controlling for possible covariates, social support from family and friends. CONCLUSIONS: Social support from significant other, rather than from family and friends, was relatively and inversely associated with 18-month all-cause readmission and cardiac readmission in patients with HF, which is consistent with the hierarchical compensatory model.

Systems Medicine Design for Triple-Negative Breast Cancer and Non-Triple-Negative Breast Cancer Based on Systems Identification and Carcinogenic Mechanisms.

Triple-negative breast cancer (TNBC) is a heterogeneous subtype of breast cancers with poor prognosis. The etiology of triple-negative breast cancer (TNBC) is involved in various biological signal cascades and multifactorial aberrations of genetic, epigenetic and microenvironment. New therapeutic for TNBC is urgently needed because surgery and chemotherapy are the only available modalities nowadays. A better understanding of the molecular mechanisms would be a great challenge because they are triggered by cascade signaling pathways, genetic and epigenetic regulations, and drug-target interactions. This would allow the design of multi-molecule drugs for the TNBC and non-TNBC. In this study, in terms of systems biology approaches, we proposed a systematic procedure for systems medicine design toward TNBC and non-TNBC. For systems biology approaches, we constructed a candidate genome-wide genetic and epigenetic network (GWGEN) by big databases mining and identified real GWGENs of TNBC and non-TNBC assisting with corresponding microarray data by system identification and model order selection methods. After that, we applied the principal network projection (PNP) approach to obtain the core signaling pathways denoted by KEGG pathway of TNBC and non-TNBC. Comparing core signaling pathways of TNBC and non-TNBC, essential carcinogenic biomarkers resulting in multiple cellular dysfunctions including cell proliferation, autophagy, immune response, apoptosis, metastasis, angiogenesis, epithelial-mesenchymal transition (EMT), and cell differentiation could be found. In order to propose potential candidate drugs for the selected biomarkers, we designed filters considering toxicity and regulation ability. With the proposed systematic procedure, we not only shed a light on the differences between carcinogenetic molecular mechanisms of TNBC and non-TNBC but also efficiently proposed candidate multi-molecule drugs including resveratrol, sirolimus, and prednisolone for TNBC and resveratrol, sirolimus, carbamazepine, and verapamil for non-TNBC.

Autoimmune and Rheumatic Manifestations Associated With COVID-19 in Adults: An Updated Systematic Review.

Background: Numerous cases of the coronavirus disease 2019 (COVID-19) with autoimmune and rheumatic manifestations have been reported. Despite the available reviews that summarized its autoimmune/rheumatic manifestations, a systematic approach is still lacking. Therefore, we conducted a comprehensive systematic review in order to give an overview upon these rare but clinically significant manifestations. Methods: We performed a literature search of PubMed and EMBASE as of October 9, 2020. All articles relevant to either systemic or organ-specific autoimmune and rheumatic manifestations potentially associated with COVID-19 were collected. The reviewed literature were limited to adults ≥18 years. Results: Although most of the existing evidence was based on case reports or case series without a long-term follow-up, a variety of autoimmune/rheumatic manifestations were associated with COVID-19. The manifestations that have a consistent association with COVID-19 include autoimmune cytopenia, cutaneous vasculitis, encephalitis, and Guillain-Barre syndrome. Such association is conflicting as regards to antiphospholipid syndrome, hemophagocytic lymphohistiocytosis, and myasthenia gravis. Conclusion: Our systematic review indicated the potential of the COVID-19 virus to trigger a myriad of autoimmune and rheumatic manifestations, which should be considered amid global efforts to combat COVID-19.

Very Robust Spray-Synthesized CsPbI3 Quantum Emitters with Ultrahigh Room-Temperature Cavity-Free Brightness and Self-Healing Ability.

Although colloidal lead halide perovskite quantum dots (PQDs) exhibit desirable emitter characteristics with high quantum yields and narrow bandwidths, instability has limited their applications in devices. In this paper, we describe spray-synthesized CsPbI3 PQD quantum emitters displaying strong photon antibunching and high brightness at room temperature and stable performance under continuous excitation with a high-intensity laser for more than 24 h. Our PQDs provided high single-photon emission rates, exceeding 9 × 106 count/s, after excluding multiexciton emissions and strong photon antibunching, as confirmed by low values of the second-order correlation function g(2)(0) (reaching 0.021 and 0.061 for the best and average PQD performance, respectively). With such high brightness and stability, we applied our PQDs as quantum random number generators, which demonstrably passed all of the National Institute of Standards and Technology's randomness tests. Intriguingly, all of the PQDs exhibited self-healing behavior and restored their PL intensities to greater than half of their initial values after excitation at extremely high intensity. Half of the PQDs even recovered almost all of their initial PL intensity. The robust properties of these spray-synthesized PQDs resulted from high crystallinity and good ligand encapsulation. Our results suggest that spray-synthesized PQDs have great potential for use in future quantum technologies (e.g., quantum communication, quantum cryptography, and quantum computing).

High performance ionic-liquid-gated air doped diamond field-effect transistors.

We report successful fabrication of high performance ion-gated field-effect transistors (FETs) on hydrogenated diamond surface. Investigations on the hydrogen (H)-terminated diamond by Hall effect measurements shows Hall mobility as high as ∼200 cm2 V-1 s-1. In addition we demonstrate a rapid fabrication scheme for achieving stable high performance devices useful for determining optimal growth and fabrication conditions. We achieved H-termination using hydrogen plasma treatment with a sheet resistivity as low as ∼1.3 kΩ/sq. Conductivity through the FET channel is studied as a function of bias voltage on the liquid ion-gated electrode from -3.0 to 1.5 V. Stability of the H-terminated diamond surface was studied by varying the substrate temperature up to 350 °C. It was demonstrated that the sheet resistance and carrier densities remain stable over 3 weeks in ambient air atmosphere even at substrate temperatures up to 350 °C, whereas increasing temperature beyond this limit has effected hydrogenation. This study opens new avenues for carrying out fundamental research on diamond FET devices with ease of fabrication and high throughput.

Perovskite Quantum Dot Lasing in a Gap-Plasmon Nanocavity with Ultralow Threshold.

Lead halide perovskite materials have recently received considerable attention for achieving an economic and tunable laser owing to their solution-processable feature and promising optical properties. However, most reported perovskite-based lasers operate with a large lasing-mode volume, resulting in a high lasing threshold due to the inefficient coupling between the optical gain medium and cavity. Here, we demonstrate a continuous-wave nanolasing from a single lead halide perovskite (CsPbBr3) quantum dot (PQD) in a plasmonic gap-mode nanocavity with an ultralow threshold of 1.9 Wcm-2 under 120 K. The calculated ultrasmall mode volume (∼0.002 λ3) with a z-polarized dipole and the significantly large Purcell enhancement at the corner of the nanocavity inside the gap dramatically enhance the light-matter interaction in the nanocavity, thus facilitating lasing. The demonstration of PQD nanolasing with an ultralow-threshold provides an approach for realizing on-chip electrically driven lasing and integration into on-chip plasmonic circuitry for ultrafast optical communication and quantum information processing.

Factors associated with sepsis risk in immune-mediated inflammatory diseases receiving tumor necrosis factor inhibitors: a nationwide study.

BACKGROUND: Risk factors for sepsis have not been assessed in patients receiving tumor necrosis factor-alpha inhibitors (TNFi) for immune-mediated inflammatory diseases (IMIDs) who are vulnerable to serious/hospitalized infections. METHODS: Data from 2003-2017 were obtained from Taiwan's National Health Insurance Research Database to identify patients receiving TNFi, including etanercept, adalimumab, and golimumab, for IMIDs including rheumatoid arthritis (RA), ankylosing spondylitis (AS), psoriasis (PsO), psoriatic arthritis (PsA), Crohn's disease (CD), and ulcerative colitis (UC). To investigate risk factors for sepsis, we used the Sepsis-3 definition and calculated hazard ratios (HRs) with 95% confidence intervals (CIs) using Cox regression analysis. RESULTS: There were 17,764 patients (mean age 49.3 ± 14.3 years; females, 57.6%) receiving TNFi for IMIDs, including RA (58.6%), AS (19.1%), PsO (15.1%), PsA (2.5%), CD (3.0%), and UC (1.7%). The overall incidence rate of sepsis was 1088 per 100,000 person-years. After adjustment for potential confounders, recent sepsis within 3 months before TNFi initiation (HR, 2.35; 95% CI, 1.73-3.20), CD (HR, 3.36; 95% CI 2.11-5.34; reference group: AS) and glucocorticoid use (prednisolone-equivalent dose, mg/day HR, 1.05; 95% CI, 1.05-1.06) were associated with the risk of sepsis. Intriguingly, golimumab users appeared to have a lower risk of sepsis compared with etanercept users (HR, 0.56; 95% CI, 0.38-0.83). In addition, socioeconomic status, including urbanization level and insured amount, was associated with sepsis in a dose-response manner. CONCLUSIONS: Recent sepsis, CD, concomitant glucocorticoid use, and low socioeconomic status, which were associated with an increased risk of sepsis, are crucial for individualized risk management plans.

Optimized oxygen deprived low temperature sputtered WO3 thin films for crystalline structures.

We report a detailed analysis on the effects of processing parameters for sputtered tungsten trioxide (WO3) thin nanoscale films on their structural, vibrational and electrical properties. The research aims to understand the fundamental aspects of WO3 sputtering at relatively low temperatures and in an oxygen deprived environment targeting applications of temperature and oxygen sensitive substrates. Structural analysis indicates that films deposited at room temperature, or substrate temperatures at or below 400 °C with low oxygen partial pressure are amorphous. Crystallization of the films was observed with distinct Raman peaks when the films were annealed at 300 °C or above using rapid thermal annealing for 10 min. Films revealed monoclinic phases of WO3 with the presence of W-O-W stretching, bending and lattice vibrational modes in the Raman spectra. Interestingly, a change of transport behavior from insulating to semiconducting was observed for as deposited films on post annealing. Annealed films revealed stoichiometric WO3 phases with no external defects detected. The present study adopts a route to intercalate WO3 in a variety of applications from electrochromic coloration to a nanocrystalline thin film for electronic devices sensitive to higher temperatures and gas flow in the sputtering system.

High-Quality Conformal Homogeneous All-Vacuum Deposited CsPbCl3 Thin Films and Their UV Photodiode Applications.

A sensitive and fast ultraviolet (UV) photodetector is strongly desirable because of its wide range of applications in chemical/biological sensing and imaging. CsPbCl3-based thin film photodetectors have not been constructed previously owing to their extremely poor precursor solubility; however, vapor deposition allows for thin film fabrication without the limitation of solubility. Therefore, this work is the first to demonstrate the optoelectronic properties of inorganic CsPbCl3 perovskite thin films and UV photodiodes using all-vacuum deposition. The perovskites annealed at 120 °C exhibited outstanding performance, including a notable external quantum efficiency value of 797.1% with an applied bias of -2 V, an outstanding detectivity of 1.4 × 1013 Jones, a short response time as low as ∼ 50 µs, and a large linear dynamic range of up to 136 dB. CsPbCl3 thin films manufactured by this vacuum-deposited approach were also found to be moisture-resistant and demonstrated high durability. The devices maintained excellent performance and demonstrated less than 10% degradation after 30 days. Thus, thin film visible-blind UV detectors can potentially be used in transparent smart displays, window-integrated electronic circuits, and sensor applications.

Prognostic Value of Anxiety Between Heart Failure With Reduced Ejection Fraction and Heart Failure With Preserved Ejection Fraction.

Background Evidence suggests differences in clinical characteristics, causes, and prognoses between heart failure with reduced ejection fraction ( HF r EF ) and heart failure with preserved ejection fraction (HFpEF). Most studies have failed to support the prognostic relevance of anxiety in HF r EF or unclassified HF with mean left ventricular ejection fraction <40%. Meanwhile, the association between anxiety and prognoses in HF p EF remains unexamined. This study compared the prognostic value of anxiety between HF r EF and HF p EF . Methods and Results A total of 158 patients with HF r EF (left ventricular ejection fraction=28.51±7.53%) and 108 patients with HFpEF (left ventricular ejection fraction=64.53±9.67%) were recruited between May 2012 and December 2014. Demographic and clinical characteristics, Spielberger State-Trait Anxiety Inventory, Beck Depression Inventory- II scale, and 18-month follow-up outcomes were recorded during the hospital stay. There were significant differences in age, sex, comorbidities, laboratory biomarkers, discharge medications, and unhealthy behaviors, which supported the contention that HF r EF and HF p EF represent 2 distinct phenotypes, although there were no significant differences in anxiety and 18-month outcomes. Multiple logistic regression yielded no significant associations between anxiety and 18-month outcomes in HF r EF . By contrast, trait anxiety could predict 18-month all-cause mortality (odds ratio, 1.429; 95% CI, 1.020-2.000; P=0.038), all-cause readmission or death (odds ratio, 1.147; 95% CI , 1.036-1.271; P=0.008), and cardiac readmission or death (odds ratio, 1.133; 95% CI , 1.031-1.245; P=0.010) in HF p EF after adjusting for possible confounders. Conclusions Trait anxiety was independently associated with 18-month all-cause mortality, all-cause readmission or death, and cardiac readmission or death in HF p EF , but not in HF r EF .

Roles of the Hydrophobic Gate and Exit Channel in Vigna radiata Pyrophosphatase Ion Translocation.

Membrane-embedded pyrophosphatase (M-PPase) hydrolyzes pyrophosphate to drive ion (H+ and/or Na+) translocation. We determined crystal structures and functions of Vigna radiata M-PPase (VrH+-PPase), the VrH+-PPase-2Pi complex and mutants at hydrophobic gate (residue L555) and exit channel (residues T228 and E225). Ion pore diameters along the translocation pathway of three VrH+-PPases complexes (Pi-, 2Pi- and imidodiphosphate-bound states) present a unique wave-like profile, with different pore diameters at the hydrophobic gate and exit channel, indicating that the ligands induced pore size alterations. The 2Pi-bound state with the largest pore diameter might mimic the hydrophobic gate open. In mutant structures, ordered waters detected at the hydrophobic gate among VrH+-PPase imply the possibility of solvation, and numerous waters at the exit channel might signify an open channel. A salt-bridge, E225-R562 is at the way out of the exit channel of VrH+-PPase; E225A mutant makes the interaction eliminated and reveals a decreased pumping ability. E225-R562 might act as a latch to regulate proton release. A water wire from the ion gate (R-D-K-E) through the hydrophobic gate and into the exit channel may reflect the path of proton transfer.

Reconfigurable Vanadium Dioxide Nanomembranes and Microtubes with Controllable Phase Transition Temperatures.

Two additional structural forms, free-standing nanomembranes and microtubes, are reported and added to the vanadium dioxide (VO2) material family. Free-standing VO2 nanomembranes were fabricated by precisely thinning as-grown VO2 thin films and etching away the sacrificial layer underneath. VO2 microtubes with a range of controllable diameters were rolled-up from the VO2 nanomembranes. When a VO2 nanomembrane is rolled-up into a microtubular structure, a significant compressive strain is generated and accommodated therein, which decreases the phase transition temperature of the VO2 material. The magnitude of the compressive strain is determined by the curvature of the VO2 microtube, which can be rationally and accurately designed by controlling the tube diameter during the rolling-up fabrication process. The VO2 microtube rolling-up process presents a novel way to controllably tune the phase transition temperature of VO2 materials over a wide range toward practical applications. Furthermore, the rolling-up process is reversible. A VO2 microtube can be transformed back into a nanomembrane by introducing an external strain. Because of its tunable phase transition temperature and reversible shape transformation, the VO2 nanomembrane-microtube structure is promising for device applications. As an example application, a tubular microactuator device with low driving energy but large displacement is demonstrated at various triggering temperatures.