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Human macrophages and the eukaryotic microbeDictyostelium discoideumingest bacteria by phagocytosis, and then kill the ingested bacteria. Some pathogenic bacteria secrete linear chains of phosphate residues (polyphosphate; polyP), and the polyP causes the phagocytes to not kill the ingested bacteria. InD. discoideum, the effect of polyP requires the G protein-coupled receptor GrlD, suggesting that polyP uses a signal transduction pathway to inhibit killing of ingested bacteria. Here we show that in addition to GrlD, theD. discoideumpolyP signaling pathway requires the GPCR interacting arrestin-like protein AdcB, inositol hexakisphosphate kinase A (I6kA), the Rho GTPase RacE, and the TOR component Lst8.D. discoideumalso secretes polyP, and at high concentrations polyP inhibitsD. discoideumcytokinesis. The polyP inhibition of bacterial killing pathway does not appear to involve many of the polyP inhibition of cytokinesis pathway components. These data suggest the intriguing possibility that if there is a similar polyP inhibition of bacterial killing pathway in macrophages, pharmacologically blocking this pathway could potentiate macrophage killing of pathogenic bacteria.ImportanceAlthough most bacteria are quickly killed after phagocytosis by a eukaryotic cell, some pathogenic bacteria prevent their killing after phagocytosis. PathogenicMycobacteriumspecies secrete polyP, and the polyP is necessary for the bacteria to prevent their killing after phagocytosis. Conversely, exogenous polyP prevents the killing of ingested bacteria that are normally killed after phagocytosis by human macrophages and the eukaryotic microbeDictyostelium discoideum. This suggests the possibility that in these cells, a signal transduction pathway is used to sense polyP and prevent killing of ingested bacteria. In this report, we identify key components of the polyP signal transduction pathway inD. discoideum. In cells lacking these components, polyP is unable to inhibit killing of ingested bacteria. The pathway components have orthologues in human cells, and an exciting possibility is that pharmacologically blocking this pathway in human macrophages would cause them to kill ingested pathogens such asM. tuberculosis.

The edge-to-edge mitral valve repair technique, invented by Alfieri and colleagues, introduced valve repair as a treatment option for patients with complex diseases where standard annuloplasty and related repair techniques are insufficient, due to annular calcification and patient frailty. We retrospectively evaluated the results of a transaortic edge-to-edge mitral valve repair (Alfieri stitch) in high-risk patients who were undergoing aortic valve replacement. From February, 2012 to December, 2017, 43 patients underwent transaortic edge-to-edge mitral valve repair with concomitant aortic valve replacement at a single institution. Preoperative and postoperative echocardiograms were compared. Home telephone follow up was conducted and postoperative morbidity was examined, including the need for reoperation, stroke and cardiac arrhythmia. 30-day and long-term survival rates were also determined. Mitral regurgitation (MR) was graded semi-quantitatively as 0 (trace and/or none), mild (1), moderate (2) or moderate to severe (3-4). The patients were 74 ± 7.8 years old. 65% of the patients were male. Mean cardiopulmonary bypass time was 115 ± 37 minutes and mean cross-clamp time was 71 ± 23 minutes. There was a significant improvement in preoperative vs postoperative median MR grade (2 (IQR 2-3) vs 0 (IQR 0-1); P = 0.05). Follow-up transthoracic echocardiograms in 29 patients obtained at a median of 9 months' (range 3 - 19 months') and in 16 patients at a median of 34 months' postoperatively (range 21 - 53 months') showed mild (1 (IQR 1-2)) grade of mitral regurgitation. 30-day survival was 98%. Long term survival at 12 and 24 months' were 88% and 81% respectively. Mitral valve reoperation was conducted in 1 patient (2%), who was suffering of endocarditis. Stroke occurred in 2 patients (7%). Cardiac arrhythmia was observed in 15 patients (35%). 8 patients (19%) suffered from atrial fibrillation and 7 patients (16%) displayed atrioventricular blockage. 10 patients (23%) could be treated conservatively and 5 patients (12%) needed implantation of a pacemaker. Transaortic edge-to-edge mitral valve repair can be safely performed during aortic valve replacement in high-risk patients and improves even long-term MR grade. Postoperative cardiac arrhythmia occurs frequently. 66% of them could be treated successfully by conservative procedures.

Background The benefit of revascularizing chronically occluded coronary arteries remains debatable, and available long-term outcome reports are sparse. Current guidelines recommend revascularization of chronically occluded arteries only in patients with myocardial ischemia and/or symptoms associated with angina. We investigated outcome of patients with total chronic occlusion of the right coronary artery (RCA) receiving coronary artery bypass grafting (CABG) surgery with and without revascularization of the RCA. Methods We retrospectively analyzed all patients with chronically occluded RCAs receiving CABG with (group 1 = RCA-CABG; n = 487) and without (group 2 = No-RCA-CABG; n = 100) revascularization of the RCA. In total, 587 patients with complete follow-up of a minimum of 6 years were included (92%). Results In total, 82% in group 1 versus 86% in group 2 were male (P = .38). European System for Cardiac Operative Risk Evaluation II was comparable between both groups (4.35 ± 7.09% vs 4.80 ± 5.77%, P = .56) with no major differences regarding preoperative characteristics between groups. Patients in group 1 received 3.24 ± 0.79 distal anastomoses, whereas group 2 received 2.45 ± 0.83 distal anastomoses (P Conclusions Patients with a chronically occluded RCA undergoing CABG who did not receive an RCA graft showed a significantly reduced long-term survival. Given the herein presented data, revascularization of chronically occluded right arteries during CABG should be recommended whenever technically feasible.

Ultrasmall ceria (CeO2) and metal-doped CeO2 nanoparticles in the sub-3 nm size regime were synthesized via a facile, single-step, liquid-phase thermal decomposition reaction in a monosurfactant me...

Summary Human pluripotent stem cell-derived cardiomyocytes (hPSC-CMs) represent an attractive model to investigate CM function and disease mechanisms. One characteristic marker of ventricular specificity of human CMs is expression of the ventricular, slow β-myosin heavy chain (MyHC), as opposed to the atrial, fast α-MyHC. The main aim of this study was to investigate at the single-cell level whether contraction kinetics and electrical activity of hESC-CMs are influenced by the relative expression of α-MyHC versus β-MyHC. For effective assignment of functional parameters to the expression of both MyHC isoforms at protein and mRNA levels in the very same hESC-CMs, we developed a single-cell mapping technique. Surprisingly, α- versus β-MyHC was not related to specific contractile or electrophysiological properties of the same cells. The multiparametric cell-by-cell analysis suggests that in hESC-CMs the expression of genes associated with electrical activity, contraction, calcium handling, and MyHCs is independently regulated., Highlights • Single-cell mapping technique allows multiparametric characterization of hESC-CMs • Twitch and action potential kinetics are independent of MyHC isoform in hESC-CMs • Myosin-mRNA levels are only weakly correlated with respective protein levels, In this article, Natalie Weber and colleagues developed a single-cell mapping technique for multiparametric analysis of hESC cardiomyocytes (hESC-CMs). Characterization of function (twitch and action potential) in direct relation to the expressed myosin heavy chain isoform by multiparametric analysis suggests that in hESC-CMs the expression of genes associated with electrical activity, contraction, calcium handling, and myosin heavy chains is independently regulated.

Two trimellitic anhydride-functionalized, thermally reduced graphenes with different aspect ratios, Af, and the same C/O ratio (8:1) were prepared and melt-mixed into poly(ethylene terephthalate) (PET), and the mechanical properties of the resulting nanocomposites were studied with a focus on plastic deformation behavior. A slight increase in the G′ of the melt was observed for the surface-modified low-Af graphene composites (Af = 20) below the percolation threshold, whereas a significant enhancement in G′ was observed for higher-Af graphene composites (Af = 80) at all graphene loadings, both below and above the percolation concentration. Furthermore, the use of modified low-Af graphene caused an improvement both in Young’s modulus and elongation at break of the resulting PET nanocomposites because of enhancement of interfacial adhesion between filler and matrix which resulted in the formation of a coupled network via covalent bonding and the suppression both of strain-induced orientation and strain-induced crystallization. By contrast, the use of modified higher-Af surface graphene in nanocomposites caused a drastic improvement in Young’s modulus but lower elongation-at-break than with the unmodified counterpart; the former effect is due to the formation of denser coupled networks and stronger interfacial adhesion as a result of graphene surface modification and the latter is due to the added geometrical restriction in unentangling chains from the PET matrix in the presence of higher-Af graphene. The preceding observations demonstrate the potential impacts of tuning both surface chemistry and aspect ratio of graphene in the fabrication of PET/graphene composites.

Aims Compelling evidence encourages the use of the radial artery (RA) as the second arterial graft in coronary artery bypass grafting (CABG). However, its long-term benefits remain disputed. We sought to evaluate long-term outcome and survival by comparing patients receiving RAs with those receiving venous grafts to a single internal thoracic artery (ITA). Methods We analyzed 345 patients undergoing primary multivessel CABG and conducted a 13-year long follow-up. In all, 187 patients received the RA and the left ITA as T-graft; 158 patients received saphenous veins complementing a single ITA. We performed propensity-score matching on 81 pairs to balance treatment selection and confounders. Results Patients receiving RAs were younger and less likely to be female or to have pulmonary hypertension, impaired renal function, or left main coronary disease.At 30 days, they showed significantly lower unadjusted mortality and renal impairment. Unadjusted long-term survival was superior in the RA group, even after propensity-score matching. We found that RA use protected from late mortality. Conclusions Using the RA and the left ITA as T-graft is associated with a significant long-term survival benefit in patients undergoing CABG. It may display a promising alternative to conventional use of a single ITA supplemented by saphenous veins.

The synthesis, characterization, and methylene blue (MB) adsorption study of a new lignosulfonate/amino-functionalized SBA-15 nanocomposite are described. (3-Aminopropyl)triethoxysilane (APTES) was grafted into SBA-15 to prepare amino-functionalized SBA-15 (N-SBA-15) which was used, along with calcium lignosulfonate (LS), to prepare a new nanocomposite LS/N-SBA-15. The prepared materials were characterized by SEM, TEM, FT-IR, Brunauer–Emmett–Teller, powder XRD, TGA analysis, and Raman spectroscopy. The experimental results indicated that the obtained nanocomposite possesses a high surface area (598 m2 g−1) and a large pore volume (1.059 cm3 g−1). This particular combination of LS and N-SBA-15 endowed this material with good dispersibility and stability in water, and better wettability. The uptake of MB from aqueous solution using the LS/N-SBA-15 nanocomposite was investigated. The adsorption investigation was performed under parameters such as pH, contact time, adsorbent dosage, temperature and initial dye concentration. The results indicated that the addition of LS to N-SBA-15 enhanced the stability of the composite in water, and improved its adsorption capacity of MB, and showed the optimum conditions at 0.05 g dose and pH = 9 during a short contact time less than 10 min. LS/N-SBA-15 exhibited a high adsorption capacity compared to other adsorbents used in the literature for the removal of MB from water. The reusability of this new nanocomposite was also investigated and the results reported. This new nanocomposite can be efficiently employed for the removal of organic dyes from wastewater.

The PSY-HEART-I trial indicated that a brief expectation-focused intervention prior to heart surgery improves disability and quality of life 6 months after coronary artery bypass graft surgery (CABG). However, to investigate the clinical utility of such an intervention, a large multi-center trial is needed to generalize the results and their implications for the health care system. The PSY-HEART-II study aims to examine whether a preoperative psychological intervention targeting patients' expectations (EXPECT) can improve outcomes 6 months after CABG (with or without heart valve replacement). EXPECT will be compared to Standard of Care (SOC) and an intervention providing emotional support without targeting expectations (SUPPORT). In a 3-arm multi-center randomized, controlled, prospective trial (RCT), N = 567 patients scheduled for CABG surgery will be randomized to either SOC alone or SOC and EXPECT or SOC and SUPPORT. Patients will be randomized with a fixed unbalanced ratio of 3:3:1 (EXPECT: SUPPORT: SOC) to compare EXPECT to SOC and EXPECT to SUPPORT. Both psychological interventions consist of 2 in-person sessions (à 50 minute), 2 phone consultations (à 20 minute) during the week prior to surgery, and 1 booster phone consultation post-surgery 6 weeks later. Assessment will occur at baseline approx. 3-10 days before surgery, preoperatively the day before surgery, 4-6 days later, and 6 months after surgery. The study's primary end point will be patients' illness-related disability 6 months after surgery. Secondary outcomes will be patients' expectations, subjective illness beliefs, quality of life, length of hospital stay and blood sample parameters (eg, inflammatory parameters such as IL-6, IL-8, CRP). This large multi-center trial has the potential to corroborate and generalize the promising results of the PSY-HEART-I trial for routine care of cardiac surgery patients, and to stimulate revisions of treatment guidelines in heart surgery.

Dictyostelium discoideumis a soil-dwelling unicellular eukaryote that accumulates extracellular polyphosphate (polyP). At high cell densities, when the cells are about to overgrow their food supply and starve, the corresponding high extracellular concentrations of polyP allow the cells to preemptively anticipate starvation, inhibit proliferation, and prime themselves to begin development. In this report, we show that starvedD. discoideumcells accumulate cell surface and extracellular polyP. Starvation reduces macropinocytosis, exocytosis, and phagocytosis, and we find that these effects require the G protein-coupled polyP receptor (GrlD) and two enzymes, Polyphosphate kinase 1 (Ppk1), which is required for synthesizing intracellular polyP, cell surface polyP, and some of the extracellular polyP, and Inositol hexakisphosphate kinase (I6kA), which is required for cell surface polyP and polyP binding to cells, and some of the extracellular polyP. PolyP reduces membrane fluidity, and we find that starvation reduces membrane fluidity, and this effect requires GrlD and Ppk1 but not I6kA. Together, these data suggest that in starved cells, extracellular polyP decreases membrane fluidity, possibly as a protective measure. In the starved cells, sensing polyP appears to decrease energy expenditure from ingestion, and decrease exocytosis, to both decrease energy expenditures and retain nutrients.

BACKGROUND: In non-ST-elevation myocardial infarction (NSTEMI) there is no consensus regarding optimal time point for coronary artery bypass grafting (CABG). Recent findings suggest that long-term outcomes are improved in early-revascularized NSTEMI patients. However, it has been stated that early surgery is associated to increased operative risk. In this study, we wanted to elucidate if early CABG in non-ST-elevation acute coronary syndrome can be performed safely. METHODS: We performed a monocentric-prospective observational study within a 2-year interval. A total of 217 consecutive patients (41 female, age 68.9±10.2, ES II 6.62±8.56) developed NSTEMI and underwent CABG. Patients were divided into two groups according to the time point of coronary artery bypass after symptom onset (group A: 72 h). Endpoints included 6-month mortality and incidence of MACE (death, stroke or re-infarction). RESULTS: There were no differences regarding mortality between both groups (30 days: group A 2.4% vs. group B 3.7%; P=0.592; 6 months: 8.4% vs. 6.0%; P=0.487). Incidence of MACE in the 6-month follow-up was also similar in both groups (group A: 9.6% vs. 9.7%, P=0.982). Regression analysis revealed as independent risk factors for mortality in the entire cohort ES II OR 1.045 (95% CI: 1.004–1.088). ES II remained an independent prognostic factor in group A OR 1.043 (95% CI: 1.003–1.086) and group B OR 1.032 (95% CI: 1.001–1.063). CONCLUSIONS: Early revascularized patients showed a higher level of illness. However, results of early CABG were comparable to those following delayed revascularization. Moreover, EuroSCORE II was determined as independent risk factors for mortality.

In this study, activated carbon (AC) and nano-zerovalent copper (nZVCu) functionalized hydroxyapatite (HA) and alginate beads were synthesized and used for the removal of As3+ from aqueous solution. The characterization by X-ray diffraction, scanning electron microscopy, X-ray energy dispersive spectroscopy, X-ray photoelectron spectroscopy, transmission electron microscopy, high resolution transmission electron microscopy, BET surface area analysis, thermogravimetric analysis, and Fourier transform infrared spectroscopy revealed successful formation of the AC/nZVCu/HA-alginate, nZVCu/HA-alginate, AC/HA-alginate, and HA-alginate beads. The scanning electron microscopy and surface analysis revealed the prepared beads to be highly mesoporous which led to the maximum adsorption of As3+, i.e., 13.97, 29.33, 30.96, and 39.06 mg/g by HA-alginate, AC/HA-alginate, nZVCu/HA-alginate, and AC/nZVCu/HA-alginate beads, respectively. The thermogravimteric analysis showed the nZVCu/HA-alginate beads to be highly stable while the AC composite beads as the least stable to heat treatment. The HA-alginate beads achieved 39% removal of As3+, however, removal efficiency was promoted to 95% by coupling AC and nZVCu with HA-alginate beads at a reaction time of 120 min. The removal of As3+ by the prepared AC & nZVCu coupled HA-alginate beads was promoted with increasing [As3+]0 and [AC/nZVCu/HA-alginate]0. The pH of aqueous solution significantly influenced the removal of As3+ by AC/nZVCu/HA-alginate beads and maximum removal was achieved at pH 5.8. Freundlich adsorption isotherm and pseudo-second-order kinetic models were found to best fit the removal of As3+ by the synthesized beads. The high performance of AC/nZVCu/HA-alginate beads in the removal of As3+ even after seven cyclic treatment as well as least leaching of Cu ions into aqueous solution suggest enhanced reusability and stability of HA-alginate beads by coupling with AC and nZVCu. The results suggest that the synthesized beads have good potential for the removal of As3+ from aqueous solutions.

Zeolite-Y is one of the preferred micro-sized zeolite commonly used as a catalyst and for adsorption and separation. The size and shape of zeolite crystals have great influence on their properties therefore the synthesis of nano-size zeolite-Y has received much attention with straightforward methodology. In the present study, nano-sized zeolite-Y crystals were synthesized by the clear-solution (CS) and dense-gel (DG) methods in the presence of alkali metal chloride salt (i.e. NaCl) under organic template-free condition. The influence of the salt on the growth of nano zeolite-Y crystal size and morphology was studied systematically by varying the NaCl concentration. Depending on the method selected for synthesis (CS or DG), the growth of nano-size crystals was affected by the addition of NaCl content. In the CS method, the size of zeolite-Y crystals was found to decrease from 120 nm to 60 nm with an increase of salt content which signify the influence of salt in hindering diffusion of nutrients to the crystal nuclei in a homogeneous starting gel. Whereas, the spherical aggregates of well-shaped nanocrystals were formed with an increase of crystal size in the case of DG method. This is attributed to the suppression of the rate of crystal dissolution in dense-gel system upon introduction of salt ions. The nano-size zeolite-Y synthesized by both methods exhibited comparatively higher water adsorption capacity (15.4 ± 0.38–16.2 ± 0.41 mmol/g) than commercially available micro-size zeolite-Y (12.9 mmol/g) which can be attributed to the contribution of the meso/macropores arising from the inter-crystal voids. Hence, the synthesized nano-size zeolite-Y can be considered as promising adsorbents for water adsorption applications.

House-of-card assemblies of faujasite nanosheets were synthesized solely from inorganic sodium aluminosilicate solution following earlier findings by Khaleel et al. demonstrating the use of pre- and post-nucleation trajectories for the synthesis of high FAU content faujasite nanocrystals. In this work, the effect of combining different synthesis trajectories on the branching of FAU/EMT materials, and hence on mesopore size, was studied. The synthesized materials were characterized using wide-angle X-ray diffraction, scanning electron microscopy, transmission electron microscopy, nitrogen physisorption, and carbon dioxide adsorption. Results show that branching in faujasite can be enhanced by first mixing the sol at compositions that favor micron size crystal formation and then—after a certain time—adjusting the composition to favor FAU/EMT intergrowth. House-of-card assemblies of faujasite nanosheets, synthesized from a combination of trajectories, show smaller pores with a narrower size distribution and high external surface area while retaining high micropore volume, compared to samples from direct syntheses.

Graphene of two different aspect ratios, Af, was melt mixed with poly(ethylene terephthalate) (PET) to form amorphous PET/graphene composites with less than 5% crystallinity. The higher-order structure and mechanical properties of poly(ethylene terephthalate) (PET) in these composites were investigated using techniques such as differential scanning calorimetry and dynamic mechanical analysis, whereas transmission electron microscopy, melt rheology, and electrical conductivity were used to study the graphene dispersion. A decrease in heat capacity changes, ΔCp, of PET in nanocomposites at the glass transition temperature, Tg, without Tg change suggests that a rigid amorphous fraction (RAF) of PET was formed at the PET/graphene interface. The stiffening effect of graphene below 1 wt % loading is quite small in the glassy state region and independent of the Af of graphene. Above 2 wt %, graphene forms a mechanical percolation network with the RAF of PET and the PET chains are geometrically restricted by the incorporation of graphene with a high Af, resulting in an unexpectedly higher modulus of nanocomposites both below and above Tg.

Graphene was modified with trimellitic anhydride groups, and its polyethylene-terephthalate-based (PET-based) nanocomposites were prepared by melt-mixing. Percolation thresholds observed from chang...

Zeolite-Y with different particle size was synthesized and the growth of crystals was studied in the presence of a cationic polyelectrolyte (PDDA) functionalized graphene oxide (PDDA-GO). The assembly of PDDA-GO was found to be cooperative in the growth of pure zeolite-Y crystals with various particle sizes (400 nm and 100 nm). The submicron size zeolite-Y particles were grown with entrapment of the GO nanosheets and the complete removal of PDDA-GO by calcination under air atmosphere assisted nanoporosity generation in the zeolite crystals. Whereas the growth of nano-size zeolite-Y particles occurred through both side of GO surface and produce nanocomposite with inter-particles porosity. The synthesized nanoporous zeolite-Y and zeolite-Y/GO nanocomposite showed higher water adsorption capacity (259–291 mg/g) than microporous zeolite-Y that placed these adsorbents as promising candidate for water adsorption applications.

Background: Device thrombosis is one of the main complications in left ventricular assist devices (LVAD) therapy and remains a challenging issue. Data on device thrombosis management, especially on the application of direct thrombin inhibitors such as argatroban, is limited and a consensus on thrombosis management has not yet been established. Methods: In this study we analysed retrospective clinical data obtained from 26 patients on VAD therapy who received argatroban for suspected VAD thrombosis, between April, 2012 and February, 2017. Results: Thirteen patients (50%) showed resolution of thrombus after argatroban therapy. Eight of 26 patients (30.8%) were free of thrombotic events 90 days after discharge. Argatroban therapy was unsuccessful in 13 patients of the study cohort, leading to subsequent VAD-exchange. Six of 13 patients with first VAD-exchange had no thrombotic events 90 days after discharge. Six patients (23.1%) suffered from bleeding, especially gastrointestinal bleeding. No hemorrhagic strokes were observed. Three patients (11.5%) did not survive the follow-up period. Conclusions: Argatroban appears to be an alternative to other pharmacological treatment options in VAD thrombosis. Efficacy and safety characteristics are acceptable, but further investigation on larger populations is necessary.

Background Minimally invasive mitral valve surgery (MIMVS) is superior to “classical” mitral valve surgery via a sternotomy regarding wound healing and postoperative pain. It is however a more challenging procedure. Patients' preference is leading clearly toward minimally invasive approaches, and surgeons are driven by upcoming new technologies in interventional procedures such as the MitraClip. Especially in re-do cases, the access via right mini-thoracotomy, as previously non-operated situs, is a possible advantage over a re-sternotomy. We therefore retrospectively analyzed our result regarding MIMVS in re-do cases at our institute. Methods From January 2011 and June 2016, 33 operations were MIMVS re-do procedures. Mean age was 60 years (±16 years), and 51% were male. Results Sixty-one percent were elective cases, 29% were urgent cases, and 9% were emergency operations. Operation times, cardiopulmonary bypass (CPB) times, and clamp times were 235 minutes (±51 min), 149 minutes (±42 min), and 62 minutes (±45min), respectively. Mitral valve repair and replacement was performed in 24% (n = 8) and 76% (n = 25), respectively. Overall in-hospital mortality, apoplexy, and re-operation rates (all for bleeding) were 0% (n = 0), 3% (n = 1), and 9% (n = 3). New onset of dialysis was required in two (6%) patients. Two (6%) patients developed superficial wound infection. Overall intensive care unit (ICU) and hospital stay was 3 days (±4 days) and 15 days (±7 days), respectively. Conclusion MIMVS for re-do cases can be performed with minimal mortality and morbidity and therefore represents a safe alternative to conventional mitral valve surgery in cardiac re-do operations. However, postoperative morbidity is highly dependent on preoperative patient status.

In the present research work, highly sensitive, stable, capacitive type humidity sensor based on polyvinylpyrrolidone and tungsten trioxide (PVP/WO3) nanocomposite was successfully developed. The sensing materials were prepared by using simple ultrasonication method and were characterized systematically through Fourier transform infrared spectroscopy, X-ray diffraction, high resolution transmission electron microscopy. Drop casting technique was used to develop sensing device using interdigitated copper electrode. Humidity sensing properties of PVP/WO3 nanocomposite sensors were investigated thoroughly and compared with pure PVP and WO3 sensors. It was observed that the humidity sensor with 20 wt% WO3 content showed high response of 44.73 nF/%RH, short response (10 s) and recovery time (15 s) as compared to pristine PVP and WO3 sensor. Low hysteresis value of 1.3 % was observed for PVP/WO3 20 wt% nanocomposite sensor along with excellent stability and repeatability.

This study focuses on the preparation of composite beads CeO2@Alginate using a one-pot method. Ce(III) was used as a crosslinking agent and then was modified with a base to transform it into CeO2 encapsulated in the alginate matrix. To study the catalytic behavior of this material the reduction of MB dye in the presence of NaBH4 was selected as a model reaction. Several parameters affecting the reduction of the MB dye were studied such as the effect of cerium content in the composite beads, the concentration of NaBH4 and the concentration of the MB dye. The results showed that the dispersion of alginate in a solution containing Ce(III) leads to the formation of hydrogel beads. The treatment of the beads with a basic solution leads to the in-situ formation of CeO2 inside the beads with a porous structure. The catalytic activity of composite beads has shown interesting results via the reduction of MB dye. The reduction of MB dye catalyzed by CeO2@ALG(2%) was total in 2 min and the associated rate constant was 2.3 min–1. The reuse tests were studied during five successive cycles, in which it was shown that the CeO2@ALG(2%) catalyst was stable without losing its effectiveness.

The current study deals with the preparation and development of nanomaterials based on iron, copper, chromium or cobalt to study their antibacterial and catalytic properties. To achieve this, the different metals were dispersed in the material MIL-101(Cr) by an ultrasonic-assisted method and then treated by chemical reduction in order to produce corresponding metal nanoparticles (MNPs). The obtained nanocatalysts MIL-101(Cr)/MNPs were characterized by various techniques such as XRD, XPS, SEM, TEM, FTIR; TGA, XRF, Adsorption-desoprtion of nitrogen at 77 K and UV–vis DR. The results showed that the nanocatalysts consist of a mixture of metal phases and oxides. All the prepared nanocatalysts were evaluated based on their performance in reducing the methylene blue (MB) dye in the presence of NaBH4 as reducing agent, for selection of the optimal catalyst. The best catalytic activity was obtained by the MIL-101 (Cr)/CuNPs nanocatalyst in which 6 min was sufficient to reduce the MB dye and the recorded rate constant kapp was 0.503 min−1. The performance of this catalyst was evaluated by varying the effects of three important parameters such as catalyst loading and the concentration of NaBH4 and MB dye. The study of the effects of these three parameters on the reduction process reveals that more than 99% of MB dye was reduced using 0.6 mM of MB dye, 6.8 mM of NaBH4 and 3 mg of nanocatalyst. The kinetic study shows that the reduction of MB dye by the MOF-101(Cr)/CuNPs nanocatalyst follows pseudo-first order kinetics. In addition, the MIL-101(Cr)/CoNPs and MIL-101(Cr)/CuNPs samples demonstrated efficacy at inhibiting bacterial and fungal growth. Hence, it is concluded through this work that the nature, size and concentration of nanoparticles present in the MOF matrix are the key parameters that can influence the catalytic and antibacterial properties of these MNP-loaded MIL-101(Cr) systems.

In this work, we use Langmuir film-balance techniques and high resolution Brewster angle microscopy (BAM) to investigate the surface activity of graphene oxide (GO) at the air-water interface. We focus on GO loading efficiency and packing at the air-water interface. We position two Wilhelmy plate tensiometers in different locations to simultaneously measure anisotropic forces as well as spatial inhomogenities in GO film coverage. We confirm our results with single sheet resolution images of GO at the air-water interface. Evidence is presented to show that GO does not significantly rearrange itself at the air-water interface over several hours. It is shown using a series of successive loading experiments that the GO surface loading efficiency decreases with each successive experiment. We also provide a detailed study of GO surface coverage with pH cycling of the subphase. In addition to subphase pH and GO sheet size we demonstrate the role of subphase pH history in determining GO surface coverage. Finally, we present a hypothesis to complement existing explanations of GO surface activity. This hypothesis explains the role of acidic pH in imparting surface active character to the GO and how GO is driven to the interface. We reconcile previous reports that while there is significant potential in the pH tunability of GO surface activity, there are also limitations pertaining to dynamics and size-selectivity. Our results present a comprehensive and high resolution perspective on the colloidal sheets packing of GO at the air-water interface and examples of how GO films are sensitive to preparation history.

In this work, we model the rheology of dilute colloidal oblate spheroids in their high aspect ratio limit of circular disks. Theoretical models for the intrinsic viscosity, [η], of disks in shear flow are reviewed: The shear-independent, monodisperse Kuhn-Kuhn model, its polydisperse form by van der Kooij, and the shear-dependent models of Stewart and Sorenson, Leal and Hinch, and Brenner. Based on these previous works, three analytical models are introduced to describe the shear response over the entire range of practically accessible rotational Peclet numbers (Pe) and aspect ratios. Using the fact that [η] is linearly additive for sufficiently dilute systems we derive a general expression for polydisperse disks as a function of the two independent variables of particle diameter D and thickness t, that is, assuming D and t to be uncorrelated independent variables. We then argue for continuum modeling being preferable to discrete for using rheological measurements to estimate particle size distribution pa...

Objectives Cardiopulmonary bypass (CPB) is an essential component of many cardiac interventions, and therefore, there is an increasing critical demand to minimize organ damage resulting from prolonged extracorporeal circulation. Our goal was to develop the first clinically relevant mouse model of CPB and to examine the course of extracorporeal circulation by closely monitoring haemodynamic and oxygenation parameters. Methods Here, we report the optimization of device design, perfusion circuit and microsurgical techniques as well as validation of physiological functions during CPB in mice after circulatory arrest and reperfusion. Validation of the model required multiple blood gas analyses, and therefore, this initial report describes an acute model that is incompatible with survival due to the need of repetitive blood draws. Results Biochemical and histopathological assessment of organ damage revealed only mild changes in the heart and lungs and signs of the beginning of acute organ failure in the liver and kidneys. Conclusions This new CPB mouse model will facilitate preclinical testing of therapeutic strategies in cardiovascular diseases and investigation of CPB in relation to different insults and pre-existing comorbidities. In combination with genetically modified mice, this model will be an important tool to dissect the molecular mechanisms involved in organ damage related to extracorporeal circulation.