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1.
J Clin Med ; 12(23)2023 Nov 22.
Article in English | MEDLINE | ID: mdl-38068282

ABSTRACT

BACKGROUND: mitral regurgitation (mr) is the most common valvular heart disease (vhd) in the elderly and tends to be more prevalent in women. while relevant sex differences in outcomes are evident in surgically treated collectives, there are very limited and conflicting sex-specific data for the growing cohort of patients undergoing transcatheter edge-to-edge repair (teer). OBJECTIVE: to investigate whether sex impacts procedural safety and efficacy, and in-hospital- and long-term outcomes, after teer for mr. METHODS: in a multicenter observational cohort study, patients who underwent teer were stratified by sex and relevant outcome measures, and analyzed using multivariable cox regression and propensity score matching (psm). RESULTS: a total of 821 patients were analyzed, of whom 37.4% (307/821) were female. compared to male patients, females were significantly older (77 ± 8.5 vs. 80.4 ± 6.7 years, p = 0.03), and had less coronary artery disease (cad, 67.7% vs. 53.1%, p < 0.0001) and a higher proportion of preserved left ventricular function (lvef > 50%, 32.5% vs. 50.5%, p > 0.0001). safety and efficacy of the teer procedure and in-hospital mortality did not differ between the sexes. after psm, women showed significantly better survival 3 years after teer compared to men (60.7% vs. 54.2%, p = 0.04) and a lower risk of all-cause death according to multiple cox regression (hr 0.8, 95% ci 0.6-0.9, p = 0.02). after sex-specific stratification for concomitant atrial fibrillation (af), the most common comorbidity in the present collective, women with af experience significantly worse adjusted survival compared to women without af (53.9% vs. 75.1%, p = 0.042) three years after teer and lose the survival advantage over men. CONCLUSIONS: female patients are older and less comorbid than males undergoing TEER. The TEER procedure is equally safe and effective in both sexes. While in-hospital mortality did not differ, female patients experienced a significantly better adjusted long-term survival compared to male patients. Concomitant AF offsets the prognostic advantage of females over males and, in contrast to males, significantly impairs long-term survival in women undergoing TEER. Further research is warranted to elucidate underlying causes for the observed sex disparities and to develop sex-tailored treatment recommendations.

2.
Front Cardiovasc Med ; 10: 1229651, 2023.
Article in English | MEDLINE | ID: mdl-37645518

ABSTRACT

Background: Atrial fibrillation (AF) is the most common concomitant disease in patients undergoing transcatheter edge-to-edge repair (TEER) for mitral regurgitation (MR) and detrimentally affects their outcome. While there is increasing evidence for prognostic improvement and safety of catheter ablation (CA) of AF in the overall cohort of heart failure patients, corresponding data in TEER patients are lacking. Objectives: To investigate the impact of treatment regimens for concomitant AF on survival of TEER patients. Methods: In a multicenter observational cohort study consecutive patients successfully undergoing TEER were analyzed and survival of patients receiving CA of concomitant AF was compared with that of patients on pharmacological AF treatment and with that of patients without a history of AF, using propensity score matching (PSM). Results: A total of 821 patients were analyzed. Of these, 608 (74.1%) had concomitant AF, of whom 48 patients received CA. Patients with CA in AF showed significantly higher 3-year-survival after TEER compared to PSM-patients on pharmacological AF treatment (75.5% [36/48] vs. 49.4% [166/336], p = 0.009). The 3-year-survival after TEER of patients with concomitant AF treated with CA was not significantly different from PSM-patients without AF (75.5% [36/48] vs. 68.3% [98/144], p = 0.36). Conclusions: CA of AF is superior to pharmacotherapy as it significantly improves the survival of TEER patients in a PSM analysis. CA even offsets the prognostic disadvantage of coexisting AF in TEER patients. Given the growing evidence of prognostic benefits in the overall cohort of HF patients, our data point out the importance of treating concomitant AF and support CA as an essential part of a holistic management of TEER patients.

3.
Polymers (Basel) ; 15(12)2023 Jun 07.
Article in English | MEDLINE | ID: mdl-37376241

ABSTRACT

Investigations of historical conservation materials on historical stained glass windows of the Naumburg Cathedral in Germany offered an opportunity for the study of polymers, naturally aged in a non-controlled environment. This allowed the conservation history of the cathedral to be traced and expanded by valuable insights. The historical materials were characterized through the use of spectroscopy (FTIR, Raman), thermal analysis, PY-GC/MS, and SEC on taken samples. The analyses show that acrylate resins were predominantly used for conservation. The lamination material from the 1940s is particularly noteworthy. Epoxy resins were also identified in isolated cases. Artificial aging was used to investigate the influence of environmental influences on the properties of the identified materials. Through a multi-stage aging program, influences of UV radiation, high temperatures and high humidity can be considered in isolation. Piaflex F20, Epilox, Paraloid B72 as a modern material and combinations of Paraloid B72/diisobutyl phthalate and PMA/diisobutyl phthalate were investigated. The parameters yellowing, FTIR spectra, Raman spectra, molecular mass and conformation, glass transition temperature, thermal behavior, and adhesive strength on glass were determined. The effects of the environmental parameters on the investigated materials are differentiated. UV and extreme temperatures tend to show a stronger influence than humidity. The comparison of the artificially aged samples with the naturally aged samples from the cathedral shows that the latter were less aged. Recommendations for the conservation of the historical stained glass windows were derived from the results of the investigation.

4.
J Cardiovasc Dev Dis ; 9(11)2022 Oct 25.
Article in English | MEDLINE | ID: mdl-36354765

ABSTRACT

Transcatheter edge-to-edge mitral valve repair (TEER) has become established as a safe and efficacious therapy for severe mitral regurgitation (MR) in high-risk patients. Despite its widespread use, postprocedural antithrombotic therapy (ATT) still to date is based on local expertise rather than evidence. In a multicenter, observational cohort study, 646 consecutive patients undergoing TEER were enrolled; 609 patients were successfully treated and antithrombotic therapy analyzed; 449 patients (73.7%) were previously treated with oral anticoagulants (OAC) due to the high prevalence of atrial fibrillation (459/609, 75.4%). Postprocedural ATT in patients previously treated with OAC consisted of no additional, additional single (SAPT) or dual antiplatelet therapy (DAPT) in 146/449 (33.6%), 248/449 (55.2%) and 55/449 (12.2%), respectively. There were 234/449 (52.1%) patients treated with vitamin-k antagonists (VKA) and 215/449 (47.9%) with nonvitamin-k antagonist oral anticoagulants (NOAC). One hundred sixty patients (26.3%) had no prior indication for OAC and were predominantly treated with DAPT (132/160, 82.5%). Use of SAPT (17/160, 10.6%) and no APT (11/160, 6.9%) was marginal. No statistically significant differences in terms of in-hospital mortality or the rate of major adverse cardiac and cerebrovascular events (MACCE) between the different antithrombotic therapy regimens were observed. Multiple Cox regression analysis showed a statistically significant decreased risk for all-cause mortality after a median follow-up of 419 days for OAC monotherapy (HR 0.6, 95%-CI 0.5-0.9, p = 0.04). This study provides evidence for a more favorable long-term outcome of OAC monotherapy in patients with an indication for OAC and reiterates the urgent need for randomized controlled trials on the optimal antithrombotic treatment of TEER patients.

5.
ACS Appl Mater Interfaces ; 14(39): 44772-44781, 2022 Oct 05.
Article in English | MEDLINE | ID: mdl-36153978

ABSTRACT

We designed high-volumetric-energy-density supercapacitors from monolithic composites composed of self-standing carbon foam (CF) as the conducting matrix and embedded hierarchically organized porous carbon (PICK) as the active material. Using multiprobe scanning tunneling microscopy at selected areas, we were able to disentangle morphology-dependent contributions of the heterogeneous composite to the overall conductivity. Adding PICK is found to enhance the conductivity of the monoliths by providing additional links for the CF network, enabling high and stable performance. The resulting all-carbon CF-PICK composites were used as self-standing electrodes for symmetric supercapacitors without the need for a binder, additional conducting additive, metals as a current collector, or casting/drying steps. Supercapacitors achieved a capacitance of 181 F g-1 based on the entire mass of the monolithic electrode as well as an outstanding rate capability. Our symmetrical supercapacitors also delivered a record volumetric energy density of 19.4 mW h cm-3 when using aqueous electrolytes. Excellent cycling stability with almost quantitative retention of capacitance was found after 10,000 cycles in 6.0 M KOH as the electrolyte. Furthermore, charge-discharge testing at different currents demonstrated the fast charge-discharge capability of this material system that meets the requirements for practical applications.

6.
Sci Total Environ ; 806(Pt 4): 150611, 2022 Feb 01.
Article in English | MEDLINE | ID: mdl-34610398

ABSTRACT

Municipal sewage sludge has been shown to be high in microplastics (MP) and is applied to agricultural land as fertiliser in many countries. The authors recently proposed in a viewpoint article that MP applied to land in this way may well contaminate other areas in an uncontrolled way. This study examined experimental plots with known history of application of sewage sludge. Results showed that 44% of the MP load found on sludge-applied land was found on nearby land never directly applied with sludge. Examination of polymer type compositions demonstrated marked similarity between the two fields indicating the sludge-applied field was a source of contamination for surrounding areas. Furthermore, MP was detected at a depth of 60-90 cm in the sludge-applied soil indicating that MP may also penetrate deep enough to reach agricultural drainage systems, although this effect is slight (1.6% of surface load). These results show that application of municipal sewage sludge on agricultural land can lead to further uncontrolled contamination, paving the way for future research to improve understanding of the extents of such effects on real farms to better inform future agricultural policy.


Subject(s)
Microplastics , Sewage , Agriculture , Plastics , Soil
7.
Sci Total Environ ; 818: 151812, 2022 Apr 20.
Article in English | MEDLINE | ID: mdl-34808158

ABSTRACT

Microplastic (MP) appears to be omnipresent in the atmosphere, raising concerns about dispersion across environmental compartments, ecological consequences and human health risks by inhalation. To date, data on the sources of atmospheric MP and deposition to river catchment areas are still sparse. We, therefore, took aerosol and total atmospheric deposition samples in the catchment area of the large German river Weser to estimate microplastic deposition fluxes (DFs) at six specific sites and airborne MP concentrations. Sampling in rural, suburban, and urban environments and wastewater treatment plants (WWTPs) was performed, aiming at a variation in airborne MP pollution and elucidating potential MP source areas. Aerosol samples were taken twice in April and October while monthly total deposition samples were collected over a period from March to October. Microplastics were detected in all analysed aerosol samples by Raman spectroscopy down to 4 µm, and in all 32 total deposition samples by µFT-IR down to 11 µm. Average MP number concentrations of 91 ± 47 m-3 were found in aerosol samples. The measured total MP number DFs ranged between 10 and 367 N m-2 day-1 (99 ± 85 mean ± SD) corresponding to total deposition of 0.05 ± 0.1 kg ha-1 per year and to an estimated 232 metric tons of plastic being deposited in the Weser River catchment annually. MP number DFs were higher in urban than rural sites. An effect of WWTPs on the MP abundance in air was not observed. Polypropylene, polyethylene, polyethylene terephthalate, polyvinyl chloride, polystyrene, and silicone fragments were found as the predominant polymer types in total deposition samples, while polyethylene particles dominated in aerosol samples. The results suggest that proximity to sources, especially to cities, increase the numbers of MP found in the atmosphere. It further indicates that atmospheric MP considerably contributes to the contamination of both aquatic and terrestrial habitats.


Subject(s)
Microplastics , Water Pollutants, Chemical , Environmental Monitoring , Humans , Plastics , Polyethylene/analysis , Rivers , Water Pollutants, Chemical/analysis
8.
J Clin Med ; 10(21)2021 Oct 28.
Article in English | MEDLINE | ID: mdl-34768567

ABSTRACT

Atrial fibrillation (AF) is a highly prevalent comorbidity in patients with severe mitral valve regurgitation (MR) undergoing transcatheter mitral valve repair (TMVR) and has been shown to significantly worsen their outcome. However, data on the impact of AF treatment strategy in this rapidly growing cohort of patients is unknown. In a multicenter, observational cohort study, 542 consecutive patients undergoing TMVR were enrolled, and subsequently, comprehensive survival analyses according to AF status and therapy were performed using propensity score matching and Cox regression. In the analyzed cohort, 373 (73.3%) of the TMVR patients had concomitant AF. Of these patients, 212 (59%) were on rate control therapy and 161 (41%) were on rhythm control therapy. At 3 years, significantly reduced cumulative survival was observed for patients on rhythm compared to patients on rate control (46.7% (75/161) vs. 56.5% (91/161), p = 0.032). Amiodarone was used to a substantial extent for rhythm control and found to be an independent mortality predictor (Hazard Ratio 1.5, 95%CI 1.1-2.1, p = 0.04). The adverse outcome of concomitant AF in TMVR patients was confirmed (AF: 47.3% (126/266) vs. non-AF: 58.3% (78/133), p = 0.047). Rhythm control achieved almost exclusively pharmacologically is associated with an adverse outcome compared to the rate control of AF in TMVR. This raises awareness of the importance of AF and its treatment, as this seems to be a promising key point for improving the prognosis of TMVR patients.

9.
Anal Bioanal Chem ; 413(24): 5969-5994, 2021 Oct.
Article in English | MEDLINE | ID: mdl-34283280

ABSTRACT

Microplastics are a widespread contaminant found not only in various natural habitats but also in drinking waters. With spectroscopic methods, the polymer type, number, size, and size distribution as well as the shape of microplastic particles in waters can be determined, which is of great relevance to toxicological studies. Methods used in studies so far show a huge diversity regarding experimental setups and often a lack of certain quality assurance aspects. To overcome these problems, this critical review and consensus paper of 12 European analytical laboratories and institutions, dealing with microplastic particle identification and quantification with spectroscopic methods, gives guidance toward harmonized microplastic particle analysis in clean waters. The aims of this paper are to (i) improve the reliability of microplastic analysis, (ii) facilitate and improve the planning of sample preparation and microplastic detection, and (iii) provide a better understanding regarding the evaluation of already existing studies. With these aims, we hope to make an important step toward harmonization of microplastic particle analysis in clean water samples and, thus, allow the comparability of results obtained in different studies by using similar or harmonized methods. Clean water samples, for the purpose of this paper, are considered to comprise all water samples with low matrix content, in particular drinking, tap, and bottled water, but also other water types such as clean freshwater.


Subject(s)
Drinking Water/chemistry , Guidelines as Topic , Microplastics/analysis , Practice Guidelines as Topic , Spectrophotometry, Infrared/methods , Spectrum Analysis, Raman/methods , Water Pollutants, Chemical/analysis
10.
Environ Pollut ; 286: 117524, 2021 Oct 01.
Article in English | MEDLINE | ID: mdl-34116488

ABSTRACT

Microplastic (MP) has been detected ubiquitously in freshwater systems. Until now MP sampling, however, is predominantly based on short-term net or pumping and filtration systems which can only provide snapshots of MP abundance; especially in flowing water bodies. To improve representativeness in the determination of MP occurrences in these aquatic compartments, an integrative approach that covers larger water volumes for a longer period of time is required. In this regard, surface water supplied drinking water treatment plants (DWTPs) represent an opportunity. In DWTPs, suspended solids from thousands of cubic metres of raw water are continuously removed over several hours and enriched in coagulation/flocculation and filtration processes. Our hypothesis was that MP is also removed to a full extent, like suspended solids, and that an integrative approach for identification and quantification in raw water can be derived from the analysis of MP in the treatment sludge. To prove this hypothesis, treatment sludge from a riverside DWTP (Warnow river, North-Eastern Germany) was analysed for MP > 50 µm. A sample purification protocol overcoming potential matrix effects caused by coagulants and flocculants was developed and validated. MP was analysed using micro-Raman spectroscopy. MP occurrence determined for the Warnow river was compared with in situ reference sampling using an established pumping and filtration system at relatively stable flow conditions. As result, the number of MP particles derived from treatment sludge was extrapolated to 196 ± 42 m-3 for the Warnow river and is statistically insignificantly different from 233 ± 36 m-3 identified by conventional water sampling. In addition, the polymer distribution and particles shape indicated the validity of the integrative concept. Consequently, the determination of MP abundance for freshwater systems based on DWTP treatment sludge represents an adequate method to estimate MP concentrations in flowing waters in an integrative way.


Subject(s)
Drinking Water , Water Pollutants, Chemical , Environmental Monitoring , Fresh Water/analysis , Microplastics , Plastics , Rivers , Sewage , Water Pollutants, Chemical/analysis
11.
mSphere ; 6(3): e0085120, 2021 06 30.
Article in English | MEDLINE | ID: mdl-34106771

ABSTRACT

While it is now appreciated that the millions of tons of plastic pollution travelling through marine systems carry complex communities of microorganisms, it is still unknown to what extent these biofilm communities are specific to the plastic or selected by the surrounding ecosystem. To address this, we characterized and compared the microbial communities of microplastic particles, nonplastic (natural and wax) particles, and the surrounding waters from three marine ecosystems (the Baltic, Sargasso and Mediterranean seas) using high-throughput 16S rRNA gene sequencing. We found that biofilm communities on microplastic and nonplastic particles were highly similar to one another across this broad geographical range. The similar temperature and salinity profiles of the Sargasso and Mediterranean seas, compared to the Baltic Sea, were reflected in the biofilm communities. We identified plastic-specific operational taxonomic units (OTUs) that were not detected on nonplastic particles or in the surrounding waters. Twenty-six of the plastic-specific OTUs were geographically ubiquitous across all sampled locations. These geographically ubiquitous plastic-specific OTUs were mostly low-abundance members of their biofilm communities and often represented uncultured members of marine ecosystems. These results demonstrate the potential for plastics to be a reservoir of rare and understudied microbes, thus warranting further investigations into the dynamics and role of these microbes in marine ecosystems. IMPORTANCE This study represents one of the largest comparisons of biofilms from environmentally sampled plastic and nonplastic particles from aquatic environments. By including particles sampled through three separate campaigns in the Baltic, Sargasso, and Mediterranean seas, we were able to make cross-geographical comparisons and discovered common taxonomical signatures that define the plastic biofilm. For the first time, we identified plastic-specific bacteria that reoccur across marine regions. Our data reveal that plastics have selective properties that repeatedly enrich for similar bacteria regardless of location, potentially shifting aquatic microbial communities in areas with high levels of plastic pollution. Furthermore, we show that bacterial communities on plastic do not appear to be strongly influenced by polymer type, suggesting that other properties, such as the absorption and/or leaching of chemicals from the surface, are likely to be more important in the selection and enrichment of specific microorganisms.


Subject(s)
Bacteria/genetics , Bacteria/isolation & purification , Microbiota , Plastics , Seawater/microbiology , Bacteria/metabolism , Biofilms/growth & development , Geography , RNA, Ribosomal, 16S , Water Pollutants, Chemical/analysis
12.
J Hazard Mater ; 414: 125482, 2021 07 15.
Article in English | MEDLINE | ID: mdl-34030400

ABSTRACT

For commonly applied microplastic sampling approaches based on filtration, high throughput and no size-discrimination are conflicting goals. Therefore, we propose two efficient centrifugal separators for small microplastic sampling, namely the utilization of a hydrocyclone as well as a continuous flow centrifuge. Thorough method optimization was followed by application in an extensive sampling study to investigate the separators' retention behavior for particulate plastics from estuarine waters. Microplastic concentrations ranged from 193 to 2072 particles m-3. The most dominant identified polymer types were polypropylene, acrylates, polyvinyl chloride and polyethylene. More than 95% of particles were < 100 µm. For the first time in microplastic research, an expanded uncertainty was calculated according to the "Guide to the expression of Uncertainty in Measurement" (JCGM 100:2008). Bottom-up uncertainty evaluation revealed the different sampling methods (~ 44%), sample replicates (~ 26%) and the different detection techniques (~ 16%) as the major sources of uncertainty. Depending on the number of particles detected in the samples, the relative expanded uncertainty (Urel (k = 2)) ranged from 24% up to > 200% underpinning tremendous importance of sound uncertainty evaluation. Our results indicate that scientist should rethink many "observed patterns" in the literature due to being insignificant and herewith not real.

13.
Molecules ; 26(5)2021 Mar 01.
Article in English | MEDLINE | ID: mdl-33804444

ABSTRACT

Co-continuous blend systems of polycarbonate (PC), poly(styrene-co-acrylonitrile) (SAN), commercial non-functionalized multi-walled carbon nanotubes (MWCNTs) or various types of commercial and laboratory functionalized single-walled carbon nanotubes (SWCNTs), and a reactive component (RC, N-phenylmaleimide styrene maleic anhydride copolymer) were melt compounded in one step in a microcompounder. The blend system is immiscible, while the RC is miscible with SAN and contains maleic anhydride groups that have the potential to reactively couple with functional groups on the surface of the nanotubes. The influence of the RC on the localization of MWCNTs and SWCNTs (0.5 wt.%) was investigated by transmission electron microscopy (TEM) and energy-filtered TEM. In PC/SAN blends without RC, MWCNTs are localized in the PC component. In contrast, in PC/SAN-RC, the MWCNTs localize in the SAN-RC component, depending on the RC concentration. By adjusting the MWCNT/RC ratio, the localization of the MWCNTs can be tuned. The SWCNTs behave differently compared to the MWCNTs in PC/SAN-RC blends and their localization occurs either only in the PC or in both blend components, depending on the type of the SWCNTs. CNT defect concentration and surface functionalities seem to be responsible for the localization differences.


Subject(s)
Acrylic Resins/chemistry , Biocompatible Materials/chemistry , Nanotubes, Carbon/chemistry , Polycarboxylate Cement/chemistry , Polymers/chemistry , Polystyrenes/chemistry , Surface Properties
14.
ACS Chem Neurosci ; 12(7): 1178-1188, 2021 04 07.
Article in English | MEDLINE | ID: mdl-33754692

ABSTRACT

Glycosaminoglycan-based hydrogels hold great potential for applications in tissue engineering and regenerative medicine. By mimicking the natural extracellular matrix processes of growth factor binding and release, such hydrogels can be used as a sustained delivery device for growth factors. Since neural networks commonly follow well-defined, high-aspect-ratio paths through the central and peripheral nervous system, we sought to create a fiber-like, elongated growth factor delivery system. Cryogels, with networks formed at subzero temperatures, are well-suited for the creation of high-aspect-ratio biomaterials, because they have a macroporous structure making them mechanically robust (for ease of handling) yet soft and highly compressible (for interfacing with brain tissue). Unlike hydrogels, cryogels can be synthesized in advance of their use, stored with ease, and rehydrated quickly to their original shape. Herein, we use solvent-assisted microcontact molding to form sacrificial templates, in which we produced highly porous cryogel microscale scaffolds with a well-defined elongated shape via the photopolymerization of poly(ethylene glycol) diacrylate and maleimide-functionalized heparin. Dissolution of the template yielded cryogels that could load nerve growth factor (NGF) and release it over a period of 2 weeks, causing neurite outgrowth in PC12 cell cultures. This microscale template-assisted synthesis technique allows tight control over the cryogel scaffold dimensions for high reproducibility and ease of injection through fine gauge needles.


Subject(s)
Cryogels , Glycosaminoglycans , Intercellular Signaling Peptides and Proteins , Porosity , Reproducibility of Results , Tissue Engineering
15.
Appl Spectrosc ; 75(4): 395-411, 2021 Apr.
Article in English | MEDLINE | ID: mdl-33393351

ABSTRACT

Qualitative and quantitative Raman and infrared measurements on sodium nitrate (NaNO3) solutions have been carried out over a wide concentration range (5.56 × 10-6-7.946 mol/L) in water and heavy water. The Raman spectra were measured from 4000 cm-1 to low wavenumbers at 45 cm-1. Band fit analysis on the profile of the 1047 cm-1 band, ν1(a1') NO3- measured at high resolution at 0.90 cm-1 produced a small contribution at 1027 cm-1 of the isotopomer N16O218O(aq). The effect of solute concentration on the Raman and infrared bands has been systematically recorded. Extrapolation of the experimental data resulted in values for all the nitrate bands of the "free", i.e., fully hydrated NO3-(aq). However, even in dilute solutions, the vibrational symmetry of the hydrated NO3-(aq) is broken and the antisymmetric N-O stretch, which is degenerate for the isolated anion, is split by 56 cm-1. At concentrations >2.5 mol/L, direct contact between Na+ and NO3- was observed and accompanied by large band parameter changes. DFT calculations on NO3-(H2O)n (n = 1-3) led to optimized geometries and vibrational frequencies which reproduced the measured ones within an accuracy of 1%. A hydrated gas phase species Na+(H2O)10NO3- was optimized resulting in the geometry and symmetry of the nitrate, which is bound in an antisymmetric bidentate fashion with the nitrate possessing C1. The ν1 Na+(OH2) breathing mode in aqueous solution appears at 189 cm-1, whereas in heavy water, ν1 Na+(OD2) is shifted to 175.6 cm-1 due to the isotope effect. DFT calculations on hydrated Na+(OH2)n gas phase clusters provided realistic Na+ hydrate structures with n = 4 and 5, which resembled the measured frequency of ν1 Na+ OH2 mode quite well. Quantitative Raman analysis employing the symmetric stretching band, ν1(a1') NO3-, has been carried out down to concentrations as low as 5.56 × 10-6 mol/L. The in-plane deformation mode ν4(e') in the Raman scattering at higher concentrations has been used as an indicator band for directly coordinated NO3-.

16.
Nanoscale Adv ; 3(9): 2632-2648, 2021 May 04.
Article in English | MEDLINE | ID: mdl-36134148

ABSTRACT

The use of electronic devices and wireless networks is increasing rapidly, and electromagnetic (EM) pollution remediation remains a challenge. We employed a unique approach to fabricate two ultrathin (approx. 53 µm) multilayered assemblies to address this. By sequentially stacking thin films of polyvinylidene difluoride (PVDF) and polycarbonate (PC) nanocomposites and interfacially locking them with a mutually miscible polymer (PMMA, polymethyl methacrylate), materials with enhanced structural properties and electromagnetic interference (EMI) shielding performance can be designed. Utilizing reduced graphene oxide (rGO) and molybdenum disulfide (MoS2) as a template, ferrite was grown on the surface to design two different nanohybrid structures (rGO-Fe3O4 and MoS2-Fe3O4). PVDF was composited with either rGO-Fe3O4 or MoS2-Fe3O4, and multiwall carbon nanotubes (CNTs) were dispersed in the PC component. As PC and PVDF are immiscible, their poor interface would result in inferior structural properties, which can be challenging in designing EMI shielding materials due to cyclic thermal fatigue. Hence, PMMA is sandwiched to interfacially stitch the components (PC and PVDF) and improve interfacial adhesion. This was confirmed using SEM/EDS and Raman mapping/imaging. The mechanical stability of the multilayered assemblies was characterized using a dynamic mechanical analyzer (DMA), and the storage modulus was found to be as high as 2767 MPa at 40 °C (@constant frequency and strain amplitude), for the multilayered film with rGO-Fe3O4 in PVDF, PMMA as a sandwich layer and CNTs in PC. A typical assembly of 9 multilayers (∼480 µm) with rGO-Fe3O4 in PVDF, and CNTs in PC, and interfacially stitched with PMMA gave rise to a high EMI shield effectiveness (SET) of -26.3 dB @ 26.5 GHz. This unique arrangement of a multilayered assembly suppressed EMI primarily by absorption.

17.
Herz ; 46(3): 242-249, 2021 Jun.
Article in English | MEDLINE | ID: mdl-31965195

ABSTRACT

BACKGROUND: Patients at high risk of bleeding requiring percutaneous coronary intervention (PCI) need careful evaluation of both their thrombotic and their bleeding risks. In these patients, a polymer-free metallic stent coated with biolimus-A9 (BA9-DCS) followed by 1­month dual antiplatelet therapy (DAPT) could be a safe option; however, real-world data are still lacking. We analyzed the performance of the device in a real-world scenario. METHODS: Patients assessed as being at high risk of bleeding with an indication for PCI were treated with BA9-DCS and DAPT consisting of aspirin (100 mg/day) and clopidogrel (75 mg/day) for at least 1 month, followed by either oral anticoagulation or single antiplatelet therapy. No exclusion criteria were used. The primary endpoint was the occurrence of an adverse event after PCI, i.e. severe bleeding requiring hospitalization, ischemic or hemorrhagic stroke, clinically driven stent thrombosis, myocardial infarction or cardiac death. RESULTS: Overall, 89 patients were enrolled in this study [median age 75 (66-81) years; 27 females (30%)] and 171 interventions were performed. During a median follow-up of 203 (145-273) days the primary endpoint occurred in 20 patients (23%): 12 (13%) had clinically significant bleeding, four (5%) ischemic stroke and four (5%) died from cardiac causes related neither to stent thrombosis nor to acute myocardial infarction. Female gender emerged as the only statistically significant predictor of an adverse event (adjusted hazard ratio (HR) 3.3; 95% confidence interval (CI): 1.2-8.7, p = 0.017). CONCLUSION: In real-world patients at high risk of bleeding, implantation of the polymer-free metallic stent coated with Biolimus-A9 (Biofreedom®; Biosensors Europe, Morges, Switzerland) followed by 1 -month DAPT showed encouraging results without any stent thrombosis.


Subject(s)
Coronary Artery Disease , Drug-Eluting Stents , Percutaneous Coronary Intervention , Aged , Coronary Artery Disease/drug therapy , Drug Therapy, Combination , Europe , Female , Humans , Platelet Aggregation Inhibitors/adverse effects , Polymers , Sirolimus/analogs & derivatives , Switzerland , Treatment Outcome
18.
J Interv Cardiol ; 2020: 6542028, 2020.
Article in English | MEDLINE | ID: mdl-32934608

ABSTRACT

BACKGROUND: Atrial fibrillation (AF) is a highly prevalent comorbidity in patients with severe mitral valve regurgitation (MR). Recent studies show a deleterious outcome of patients with concomitant AF after transcatheter mitral valve repair (TMVR). This underlines the essential need for additional strategies that ameliorate the prognosis of these patients. Fundamental data on AF characteristics and treatment regimes in this special cohort of patients are lacking. METHODS: We retrospectively analyzed the data of 542 consecutive patients with severe MR undergoing TMVR in three tertiary heart centers with special focus on AF type and underlying treatment strategies. RESULTS: The prevalence of concomitant AF was 73.3%, and AF did not affect the procedural success or the incidence of major adverse cardiac and cerebrovascular events. The patients with AF were more frequently >75 years, had more tricuspid regurgitation, and less coronary artery disease than non-AF patients. The distribution of AF types was 32% paroxysmal AF, 27% persistent AF, and 41% permanent AF. Except for a higher degree in severe tricuspid regurgitation and a higher likelihood of male sex, no substantial differences were observed while comparing permanent and nonpermanent AF patients. The predominant treatment regime was rate control (57%), with only beta blockers (BB) in the majority of persistent and permanent AF patients, while additional digitalis or a pacemaker was used infrequently. Rhythm control was mainly achieved with BB alone in paroxysmal AF patients and with additional antiarrhythmic drugs in the majority of persistent AF patients. Interventional rhythm control therapy was performed in 2.5% and 30.9% of paroxysmal and persistent AF patients, respectively. The guideline-adherent use of oral anticoagulants was comparable and high in both groups (91.9% in nonpermanent vs. 90.1% in permanent AF). CONCLUSION: This is the first study to provide necessary information for the understanding of the current clinical practice in dealing with TMVR patients. Since evidence suggests that AF is not a benign concomitant disease, further investigations are needed to assess the prognostic impact of these different AF treatment strategies.


Subject(s)
Anti-Arrhythmia Agents , Anticoagulants , Atrial Fibrillation , Mitral Valve Annuloplasty , Mitral Valve Insufficiency , Aged , Anti-Arrhythmia Agents/therapeutic use , Anticoagulants/therapeutic use , Atrial Fibrillation/drug therapy , Atrial Fibrillation/epidemiology , Cardiac Catheterization/methods , Comorbidity , Female , Humans , Male , Medication Therapy Management , Mitral Valve Annuloplasty/methods , Mitral Valve Insufficiency/epidemiology , Mitral Valve Insufficiency/surgery , Prognosis , Risk Factors , Treatment Outcome
19.
Appl Spectrosc ; 74(9): 1185-1197, 2020 Sep.
Article in English | MEDLINE | ID: mdl-32436395

ABSTRACT

Determining microplastics in environmental samples quickly and reliably is a challenging task. With a largely automated combination of optical particle analysis, Fourier transform infrared (FT-IR), and Raman microscopy along with spectral database search, particle sizes, particle size distributions, and the type of polymer including particle color can be determined. We present a self-developed, open-source software package for realizing a particle analysis approach with both Raman and FT-IR microspectroscopy. Our software GEPARD (Gepard Enabled PARticle Detection) allows for acquiring an optical image, then detects particles and uses this information to steer the spectroscopic measurement. This ultimately results in a multitude of possibilities for efficiently reviewing, correcting, and reporting all obtained results.


Subject(s)
Environmental Monitoring/methods , Environmental Pollutants/analysis , Microplastics/analysis , Software , High-Throughput Screening Assays , Spectroscopy, Fourier Transform Infrared , Spectrum Analysis, Raman
20.
Sci Rep ; 9(1): 18839, 2019 Dec 06.
Article in English | MEDLINE | ID: mdl-31806865

ABSTRACT

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

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