Impact of pH-adjusted fluoride and stannous solutions on the protective properties on the pellicle layer in vitro and in situ

This study evaluates the ideal pH for anti-erosion and anti-adherent efficacy of fluoride and stannous solutions (sodium fluoride (SF), amine fluoride (AF), sodium monofluorophosphate (SMFP), stannous fluoride (SnF2) with 500 ppm fluoride concentration each and stannous chloride (SnCl2, 1563 ppm stannous)). In vitro, solutions were tested at pH 4.5 and 5.5. The main in situ experiments were carried out at the pH of 4.5: For pellicle formation 6 volunteers wore bovine enamel slabs intraorally for 1 min, rinsed with 8 ml solution for 1 min and continued for up to 30 min/8 h. Physiological pellicle samples served as controls. After incubation in HCl (2.0, 2.3) for 2 min mineral release was determined photometrically. Bacterial counts on 8 h biofilms were determined by fluorescence microscopy (BacLight™ and DAPI with Concanavalin A). Modification of the pellicle ultrastructure was examined by TEM. Statistical analysis was performed using Kruskal-Wallis and Mann-Whitney-U tests with Bonferroni-correction (p < 0.05). SnF2 showed a significant erosion protection. AF, SnF2, and SnCl2 were most anti-adherent. SnF2 and SnCl2 caused a pronounced basal pellicle with stannous precipitates. Compared to other fluoride monosubstances, stannous ions offer greater protection against erosive acidic attacks. Stannous ions act as crucial co-factor in this process.

Determination of the optimal feed recipe of anaerobic digesters using a mathematical model and a genetic algorithm

Recently, numerous experimental studies have been undertaken to understand the interactions between different feedstocks in anaerobic digestion. They have unveiled the potential of blending substrates in the process. Nevertheless, these experiments are time-intensive, prompting the exploration of various optimization approaches. Notably, genetic algorithms have gained interest due to their population-based structures allowing them to efficiently yield multiple Pareto-optimal solutions in a single run. This study uses a simplified static anaerobic co-digestion model as the fitness function for a multi-objective optimization. The optimization aims to achieve a methane production set-point while reducing the output ammonia nitrogen and increasing the recipe' profitability. Thus, the study employs genetic algorithms to identify Pareto fronts and constraints confined the solution space within feasible boundaries. It also underscores the influence of economic considerations on the viable solution space. Ultimately, the optimal feed recipe not only ensures stable operations within the digester but also enhances associated profits.

Are you better than me? Social comparisons in carrion crows (Corvus corone)

Comparing oneself to others is a key process in humans that allows individuals to gauge their performances and abilities and thus develop and calibrate their self-image. Little is known about its evolutionary foundations. A key feature of social comparison is the sensitivity to other individuals' performance. Recent studies on primates produced equivocal results, leading us to distinguish between a 'strong' variant of the social comparison hypothesis formulated for humans and a 'weak' variant found in non-human primates that would comprise some elements of human social comparison. Here, we focus on corvids that are distantly related to primates and renowned for their socio-cognitive skills. We were interested in whether crows' task performances were influenced (i) by the presence of a conspecific co-actor performing the same discrimination task and (ii) by the simulated acoustic cues of a putative co-actor performing better or worse than themselves. Crows reached a learning criterion quicker when tested simultaneously as compared to when tested alone, indicating a facilitating effect of social context. The performance of a putative co-actor influenced their performance: crows were better at discriminating familiar images when their co-actor was better than they were. Standard extremity (how pronounced the difference was between the performance of the subject and that of the co-actor), and category membership (affiliation status and sex), of the putative co-actors had no effect on their performance. Our findings are in line with the 'weak' variant of social comparison and indicate that elements of human social comparison can be found outside of primates.

Temporal trends regarding clinical impact of diabetes mellitus on peripheral artery disease

Introduction

Patients with peripheral artery disease (PAD) and Diabetes mellitus (DM) suffer from higher morbidity and mortality rates compared to non-diabetic PAD patients. Huge efforts are made to improve medical care of patients with DM including chronic disease programs.

Purpose

To investigate temporal trends of the clinical burden of DM on PAD patients between the years 2005 and 2019.

Methods

All patients hospitalized due to PAD between 2005 and 2019 in Germany based on the diagnosis related groups [DRG] system were stratified according to presence or absence of DM (source: Federal Statistical Offices of Germany, DRG statistics 2005–2019 and own calculations). Morbidity and mortality of both groups were compared in time trend.

Results

The number of hospitalisations due to PAD increased from 142,778 in the year 2005 to 190,135 in 2019 (β 3956 per year [95% CI 3034–4878], P&lt;0.001). In the same period also the amount of PAD patients with additional diagnosis of DM inclined (2005: 41,609 patients corresponding 29.1% of all PAD patients vs. 2019: 65,302 patients corresponding 34.3% of all PAD patients; β 2019 per year [95% CI 1593–2446], P&lt;0.001). While the portion of patients with type 1 DM decreased during the observational period (β −1.43 [95% CI −1.49 to −1.37]; P&lt;0.001), type 2 DM was progressive (β 2.27 [95% CI 2.23–2.32]; P&lt;0.001). PAD patients with DM suffered from lower rates of pulmonary embolism (β −0.64 [95% CI −0.89 to −0.40]; P&lt;0.001) and intracerebral bleeding (β −0.45 [95% CI −0.94 to 0.04]; P=0.072) in the last years of the investigation period, whereas the amount of patient-cases with pneumonia (β 0.29 [95% CI 0.23–0.35]; P&lt;0.001), shock (β 0.75 [95% CI 0.66–0.84]; P&lt;0.001) and gastrointestinal bleeding (β 0.33 [95% CI 0.20–0.46]; P&lt;0.001) increased. Fortunately, less amputations had to be performed in diabetics over time (amputations regardless of minor or major amputations: β −0.42 [95% CI −0.44 to −0.40]; P&lt;0.001; minor amputations: β −0.03 [95% CI −0.06 to −0.01]; P=0.015; major amputations: β −1.24 [95% CI −1.28 to −11.20]; P&lt;0.001) and in-hospital mortality decreased during the observational-time (2005: 4.7%, 2019: 2.8%; β −0.64 [95% CI −0.69 to −0.59]; P&lt;0.001). Despite the improvement in morbidity and mortality within the investigated time period, diabetics with DM were still associated with increased risk for morbidity and mortality compared to PAD patients without DM.

Conclusions

We observed an improvement regarding morbidity and mortality in hospitalized PAD patients with DM in Germany within the investigation period between 2005 and 2019. However, DM remained to be associated with increased morbidity and mortality compared to non-diabetics. Hence, despite the achieved improvements within the period 2005 to 2019, DM still represents an outstanding risk factor for morbidity and mortality in patients with PAD.

Funding Acknowledgement

Type of funding sources: None.

Impact of prediabetes and type 2 diabetes mellitus on cardiac function in the general population

Introduction

Prediabetes and type 2 diabetes mellitus (T2DM) are risk factors for heart failure (HF). The association of prediabetes and T2DM to different forms of functional left ventricular impairment and their impact on clinical outcome in the general population needs to be further investigated. In this context, little is known about the prevalences of prediabetes and different HF subtypes in the general population, especially in Europe.

Purpose

To investigate the prevalence and clinical impact of prediabetes and type 2 diabetes mellitus (T2DM) on functional cardiac disorder (FCD).

Methods

The participants of the Gutenberg Health Study sample (15,010 subjects, 35–74 years) were stratified in individuals with euglycaemia, prediabetes and T2DM based on clinical information and HbA1c level. FCD included asymptomatic systolic and diastolic dysfunction, symptomatic systolic and diastolic heart failure, asymptomatic diastolic dysfunction and preserved left ventricular ejection fraction (EF), asymptomatic diastolic dysfunction and reduced EF, asymptomatic preserved diastole and reduced EF, symptomatic heart failure with preserved EF (HFpEF) and symptomatic heart failure with reduced EF HFrEF). Using structured follow-up clinical outcome was assessed.

Results

Overall, 14,870 individuals were included in the present analysis. Among them, 9,426 individuals were categorized in the euglycaemia group, 4,128 participants had prediabetes and in 1,316 individuals T2DM was present. Prevalence of FCD increased from euglycaemia (19.6%) over prediabetes (33.3%) to T2DM (46.8%, p&lt;0.0001). Prevalence of symptomatic HF was increased in patients with T2DM (euglycaemia 2.8%, prediabetes 5.9%, T2DM 11.9%). T2DM was associated with reduced EF (β −0.63, 95% CI −0.99 to −0.26, P=0.00088) and elevated E/E' (β 0.08, 95% CI 0.06 to 0.10, P&lt;0.0001), whereas prediabetes was associated to elevated E/E' (β 0.02, 95% CI 0.01 to 0.03, P=0.0029). Prediabetes and T2DM revealed increased prevalences of FCD (13%, 18%), asymptomatic diastolic dysfunction with preserved EF (prediabetes: 14%, T2DM: 11%), symptomatic heart failure (prediabetes: 46%, T2DM: 70%) and HFpEF (prediabetes: 49%, T2DM: 82%). With prediabetes and T2DM all-cause mortality was elevated in presence and absence of FCD, only T2DM was also a risk factor for cardiovascular mortality with and without FCD. Within a 5-years follow-up, T2DM was an independent risk factor for the development of FCD, asymptomatic diastolic dysfunction with reduced ejection fraction, symptomatic heart failure and HFrEF. Prediabetes was not an independent risk factor for FCD.

Conclusions

In the general population, a high prevalence of asymptomatic FCD is present. Coexisting FCD and prediabetes as well as T2DM result in increased mortality elucidating the need for early detection and prevention of DM development, especially with regard to numerous asymptomatic people concerned. T2DM, but not prediabetes, is a risk factor for incident FCD.

Funding Acknowledgement

Type of funding sources: Private company. Main funding source(s): The Gutenberg Health Study is supported by the government of Rheinland-Pfalz (`Stiftung Rheinland-Pfalz für Innovation'), the research programmes `Wissen schafft Zukunft' and the Centre forTranslational Vascular Biology (CTVB) of the Johannes Gutenberg-University of Mainz, Germany, and its contract with Boehringer Ingelheim and Philips Medical Systems including an unrestricted grant forthe Gutenberg Health Study. P.S.W. and J.H.P. are funded by the Federal Ministry of Education and Research (BMBF 01EO1503). P.S.W. and T.M. are principal investigators of the German Center for Cardiovascular Research (DZHK). P.S.W. is principal investigator of the DIASyM research core (BMBF 161L0217A).

A single hole spin with enhanced coherence in natural silicon

Semiconductor spin qubits based on spin-orbit states are responsive to electric field excitations, allowing for practical, fast and potentially scalable qubit control. Spin electric susceptibility, however, renders these qubits generally vulnerable to electrical noise, which limits their coherence time. Here we report on a spin-orbit qubit consisting of a single hole electrostatically confined in a natural silicon metal-oxide-semiconductor device. By varying the magnetic field orientation, we reveal the existence of operation sweet spots where the impact of charge noise is minimized while preserving an efficient electric-dipole spin control. We correspondingly observe an extension of the Hahn-echo coherence time up to 88 μs, exceeding by an order of magnitude existing values reported for hole spin qubits, and approaching the state-of-the-art for electron spin qubits with synthetic spin-orbit coupling in isotopically purified silicon. Our finding enhances the prospects of silicon-based hole spin qubits for scalable quantum information processing.

Edge-to-edge transcatheter valve repair of atrial functional mitral regurgitation positively influences atrial pathology

Introduction

Functional mitral regurgitation (FMR) is the result of an insufficient coaptation of the mitral valve leaflets lacking relevant degeneration or morphological alterations of the valve apparatus. In most patients, this is caused by left ventricular (LV) systolic dysfunction and remodelling (ischemic or non-ischemic). However, a small subset of FMR patients is seen in the context of left atrial (LA) enlargement due to isolated atrial dilation in the absence of a ventricular pathology and has been termed “atrial functional MR” (AFMR) as a distinct etiology of FMR.

The effect of transcatheter mitral valve repair (TMVR) by edge-to-edge-repair (e.g., MitraClip®) on AFMR reduction has not been studied, but it is considered to be effective regarding its effect on the anterior-posterior mitral annular diameter.

Methods

We retrospectively screened all 737 patients treated with TMVR by edge-to-edge repair in our center between January 2013 and April 2019. AFMR was defined as FMR with: (1) relevant LA dilatation, (2) no LV systolic dysfunction or (3) dilatation, (4) no ischemic etiology of FMR. LA mean pressure was invasively measured peri-interventionally before and after device implantation. Echocardiographic assessment was repeated at 1 year follow-up (1yFUP).

Results

Among 350 patients (47.5%) with FMR, 57 patients (16.3%) met the inclusion criteria for AFMR and were included in the data analysis. All patients in the AFMR group (mean age 81.4±5.7 years, 78.9% female) were symptomatic (82.2% functional NYHA class≥III) at baseline and were assessed to be at elevated risk for surgery (mean logistic EuroScore of 24.8±12.0%).

TVMR was successfully performed in all patients without any peri-interventional major complications. At hospital discharge, 78.3% of patients had mild residual MR and 17.4% had no detectable MR. At 1 year, the echocardiographic prevalence of residual moderate MR was 11.4% and 2.9% of patients had severe MR (Figure A). Invasive LA mean pressure measurements were available in 39 patients (68.4%). In average, LA mean pressures decreased from 18.8 mmHg to 12.8 mmHg (p&lt;0.001).

Analysis at 1yFUP showed a significant reduction in LA volume, both at end-systole (79.6±31.9 vs. 66.9±31.8 ml/m2 p&lt;0.001; Figure B) and at end-diastole (61.6±21.5 vs. 50.4±27.37 ml/m2; p&lt;0.01; Figure C). LA ejection fraction increased from 18.8%±12.6% to 30.1%±12.3% in 54.8% of patients. These findings were accompanied by a relevant symptomatic benefit (NYHA class I/II was found in 66.7% of patients at 1 year).

Conclusions

Transcatheter mitral valve repair by edge-to-edge therapy in symptomatic patients with atrial functional mitral regurgitation is safe and capable of a relevant reduction of mitral regurgitation severity accompanied by symptomatic improvement and positive atrial remodeling.

Funding Acknowledgement

Type of funding sources: None.

Quantitative SPECT imaging and biodistribution point to molecular weight independent tumor uptake for some long-circulating polymer nanocarriers

Polymeric nanocarriers are promising entities for cancer diagnosis and therapy. The aim of such nanocarriers is to selectively accumulate in cancerous tissue that is difficult to visualize or treat. The passive accumulation of a nanocarrier in a tumor through extravasation is often attributed to the enhanced permeation and retention (EPR) effect and the size and shape of the nanocarrier. However, the tumor microenvironment is very heterogeneous and the intratumoral pressure is usually high, leading to different opinions about how the EPR of nanocarriers through the irregular vasculature of a tumor leads to accumulation. In order to investigate this topic, we studied methods for the determination of pharmacokinetic parameters, biodistribution and the tumor uptake of nanocarriers. More specifically, we used non-invasive quantitative Single-Photon Emission Computed Tomography/Computed Tomography (qSPECT/CT) imaging of hyperbranched polyglycerols (HPGs) to explore the specific biodistribution and tumor uptake of six model nanocarriers in Rag2m mice. We were interested to see if a distinct molecular weight (MW) of nanocarriers (HPG 25, 50, 100, 200, 300, 500 kDa) is favoured by the tumor. To trace the model nanocarriers, HPGs were covalently linked to the strong chelator desferrioxamine (DFO), and radiolabeled with the gamma emitter 67Ga (EC = 100%, E γ = 185 keV (21.4%), 300 keV (16.6%), half-life = 3.26 d). Without the need for blood collection, but instead using qSPECT/CT imaging inside the heart, the blood circulation half-lives of the 67Ga labeled HPGs were determined and increased from 9.9 ± 2.9 to 47.8 ± 7.9 hours with increasing polymer MW. Total tumor accumulation correlated positively with the circulation time of the HPGs. Comparing the tumor-to-blood ratio dynamically revealed how blood and tumor concentrations of the nanocarrier change over time and when equilibrium is reached. The time of equilibrium is size-dependent and increases with molecular weight. Furthermore, the data indicate that for larger MWs, nanocarrier uptake and retention by the tumor is size independent. Further studies are necessary to advance our understanding of the interplay between MW and nanoparticle accumulation in tumors.

Synthesis of surfactant-free micro- and nanolatexes from Pickering emulsions stabilized by acetylated cellulose nanocrystals

Surfactant-free micro- and nanolatexes from Pickering emulsions stabilized by acetylated cellulose nanocrystals (CNCs).

Drainage dynamics of thin liquid foam films containing soft PNiPAM microgels: influence of the cross-linking density and concentration

We investigate the drainage dynamics of thin liquid foam films containing PNiPAM microgel suspensions with two cross-linking densities (1.5 and 5 mol% BIS) and at two microgel concentrations (0.1 and 1% wt). For this purpose, we use a thin-film pressure balance apparatus that can apply a controlled and sudden hydrostatic pressure on a film, and record the subsequent film thinning as a function of time. Once the film thickness has reached a stationary value, we test the adhesion between the interfaces of the film by reducing the pressure and measuring the angle between the film and the meniscus. This angle increases on reduction of pressure for adhesive films, which resists the separation of their interfaces. Non-adhesive films separate easily, and the meniscus angle stays constant. At a low microgel concentration, the more densely cross-linked microgels (5 mol% BIS) tend to drain into more adhesive films than the more loosely cross-linked particles (1.5 mol% BIS). The adhesion results from particles that bridge the two air-water interfaces of the film and are shared between them. In these cases, the film, which is initially stabilized by a bilayer of microgel particles, rearrange to a state where the microgels bridge the interfaces. These results are discussed and compared with previous studies at a low concentration of microgels, which have shown that emulsions stabilized with densely cross-linked microgels are more adhesive and less resistant to mechanical stresses than those obtained with lower cross-linking densities. In addition, micron-scale depleted zones with no microgels are observed in the films stabilized with the 5 mol% BIS particles, which eventually lead to the rupture of the films. At 1% wt, the films drain slowly, are not adhesive and have the thickness of a bilayer of microgel; while at 0.1% wt, the films have the thickness of a monolayer of microgel, are adhesive and show bridging. From the thin liquid foam film thicknesses we extract a rough estimation of the radii of adsorbed particles in the thick films before applying the pressure. Our results are consistent with particles being adsorbed in a spread conformation for the 0.1% wt sample and in a compressed conformation for the 1% wt sample. In line with previous studies on emulsions, we conclude that a larger surface coverage may reduce rearrangements, thus preventing bridging.

Surgical adhesive BioGlue™ does not benefit tendon repair strength: an ex vivo study

Surgical adhesives are useful supplements in surgery, but their benefit in tendon repair is uncertain. The purpose of this study was to evaluate the effect of BioGlue™ on strength of flexor tendon repair. A total of 60 porcine flexor tendons were divided into three groups. In group one, a conventional core and peripheral suture repair was used. In group two, a core suture and BioGlue™ were used. In group three, a conventional core and peripheral suture repair and BioGlue™ were used. We performed static and cyclic axial load testing and measured diameter of the repair site. We found that BioGlue™ did not improve the tensile strength when added to a core and peripheral suture and that there was an increase in bulk at the repair site. We conclude that BioGlue™ application cannot replace a peripheral suture as tensile strength significantly decreases without a peripheral suture, and it does not benefit a tendon already repaired with a core and peripheral suture.

LEVEL OF EVIDENCE

n/a.

Co-doping of (Bi(0.5)Na(0.5))TiO(3): secondary phase formation and lattice site preference of Co

Bismuth sodium titanate (Bi(0.5)Na(0.5))TiO(3) (BNT) is considered to be one of the most promising lead-free alternatives to piezoelectric lead zirconate titanate (PZT). However, the effect of dopants on the material has so far received little attention from an atomic point of view. In this study we investigated the effects of cobalt-doping on the formation of additional phases and determined the preferred lattice site of cobalt in BNT. The latter was achieved by comparing the measured x-ray absorption near-edge structure (XANES) spectra to numerically calculated spectra of cobalt on various lattice sites in BNT. (Bi(0.5)Na(0.5))TiO(3) + x mol% Co (x = 0.0, 0.5, 1.0, 2.6) was synthesized via solid state reaction. As revealed by SEM backscattering images, a secondary phase formed in all doped specimens. Using both XRD and SEM-EDX, it was identified as Co(2)TiO(4) for dopant levels >0.5 mol%. In addition, a certain amount of cobalt was incorporated into BNT, as shown by electron probe microanalysis. This amount increased with increasing dopant levels, suggesting that an equilibrium forms together with the secondary phase. The XANES experiments revealed that cobalt occupies the octahedral B-site in the BNT perovskite lattice, substituting Ti and promoting the formation of oxygen vacancies in the material.

Formulation and mechanical properties of emulsion-based model polymer foams

We produce cellular material based on the formulation of model emulsions whose drop size and composition may be continuously tuned. The obtained solid foams are characterized by narrow cell and pore size distributions in direct relation with the emulsion structure. The mechanical properties are examined, by varying independently the cell size and the foam density, and compared to theoretical predictions. Surprisingly, at constant density, Young's modulus depends on the cell size. We believe that this observation results from the heterogeneous nature of the solid material constituting the cell walls and propose a mean-field approach that allows describing the experimental data. We discuss the possible origin of the heterogeneity and suggest that the presence of an excess of surfactant close to the interface results in a softer polymer layer near the surface and a harder layer in the bulk.

Characterization of a two-transmon processor with individual single-shot qubit readout

We report the characterization of a two-qubit processor implemented with two capacitively coupled tunable superconducting qubits of the transmon type, each qubit having its own nondestructive single-shot readout. The fixed capacitive coupling yields the sqrt[iSWAP] two-qubit gate for a suitable interaction time. We reconstruct by state tomography the coherent dynamics of the two-bit register as a function of the interaction time, observe a violation of the Bell inequality by 22 standard deviations after correcting readout errors, and measure by quantum process tomography a gate fidelity of 90%.

Coupling a quantum dot, fermionic leads, and a microwave cavity on a chip

We demonstrate a hybrid architecture consisting of a quantum dot circuit coupled to a single mode of the electromagnetic field. We use single wall carbon nanotube based circuits inserted in superconducting microwave cavities. By probing the nanotube dot using a dispersive readout in the Coulomb blockade and the Kondo regime, we determine an electron-photon coupling strength which should enable circuit QED experiments with more complex quantum dot circuits.

Particle-stabilized emulsions comprised of solid droplets

We kinetically stabilize oil-in-water emulsions comprising paraffin crystals by adsorbing solid particles (silica) of colloidal size at the oil/water interface. We obtain a set of emulsions that are quiescently stable for a long period of time (months), while the same emulsions are destabilized after only a few hours in the presence of surfactant molecules alone. The emulsions are submitted to a shear stress in order to probe their stability under flow conditions. Partial coalescence and gelation occur when the shear is applied for a sufficiently long period of time. The experiments reveal the existence of a critical droplet mass fraction, phi*, that defines a sharp transition between slow and fast gelation. The process of gelation is rather slow for phi < phi*, occurring at the scale of hours, and becomes almost instantaneous above phi*.

Coarsening of alkane-in-water emulsions stabilized by nonionic poly(oxyethylene) surfactants: the role of molecular permeation and coalescence

We produce different alkane-in-water concentrated emulsions stabilized by the same nonionic surfactant, and we follow their kinetic evolution by granulometry. The size distribution becomes remarkably narrow during the first stages of coarsening and progressively turns to a wide function as time passes. We get evidence that the size evolution occurs under the effect of molecular permeation and coalescence. A second hydrophobic species of large molecular size is dissolved in the dispersed phase. This latter is expected to inhibit the permeation mechanism, and coalescence should act alone. Surprisingly, coalescence is also suppressed, even at a very low concentration of the second component (approximately 1% w/w). We vary the chemical nature and concentration of the second species, and we propose a simple mechanism to explain the stabilizing effect with respect to coalescence.

Some general features of limited coalescence in solid-stabilized emulsions

We produce direct and inverse emulsions stabilized by solid mineral particles. If the total amount of particles is initially insufficient to fully cover the oil-water interfaces, the emulsion droplets coalesce such that the total interfacial area between oil and water is progressively reduced. Since it is likely that the particles are irreversibly adsorbed, the degree of surface coverage by them increases until coalescence is halted. We follow the rate of droplet coalescence from the initial fragmented state to the saturated situation. Unlike surfactant-stabilized emulsions, the coalescence frequency depends on time and particle concentration. Both the transient and final droplet size distributions are relatively narrow and we obtain a linear relation between the inverse average droplet diameter and the total amount of solid particles, with a slope that depends on the mixing intensity. The phenomenology is independent of the mixing type and of the droplet volume fraction allowing the fabrication of both direct and inverse emulsion with average droplet sizes ranging from micron to millimetre.

Epidemiology of severe brain injuries: a prospective population-based study

BACKGROUND

The aim of this prospective study was to estimate annual incidences of hospitalization for severe traumatic brain injury (TBI) (maximum Abbreviated Injury Score in the head region [HAIS] 4 or 5) in a defined population of 2.8 million.

METHODS

Severe TBI patients were included in the emergency departments in the 19 hospitals of the region. A prospective data form was completed with initial neurologic state, computed tomographic scan lesions, associated injuries, length of unconsciousness, and length of stay in acute care centers. Outcome at the time the patient left acute hospitalization was retrospectively assessed from medical notes.

RESULTS

During the 1-year period (1996), 497 residents fulfilled the inclusion criteria, leading to an annual incidence rate of 17.3 per 100,000 population; 58.1% were HAIS5. Mortality rate was 5.2 per 100,000. Men accounted for 71.4% of cases. Median age was 44 years, with a quarter of patients more than 70 years old. Traffic accidents were the most frequent causes (48.3%), but falls accounted for 41.8% of all patients. Age and severity were different according to the major categories of external causes. In HAIS5 patients, 86.5% were considered as comatose (coma lasting more than 24 hours or leading to immediate death) but only 60.9% had an initial Glasgow Coma Scale score < 9. In the HAIS4 group, 7.2% had an initial Glasgow Coma Scale score < 9. Fatality rates were 30.0% in the whole study group, 7.7% in HAIS4, 12.8% in HAIS5 without coma, and 51.2% in HAIS5 with coma.

CONCLUSION

This study shows a decrease in severe TBI incidence when results are compared with another study conducted 10 years earlier in the same region. This is because of a decrease in traffic accidents. However, this results in an increase in the proportion of falls in elderly patients and an increase in the median age in our patients. This increased age influences the mortality rate.

Rheological Behavior of Fluorinated Highly Concentrated Reverse Emulsions with Temperature

Reverse highly concentrated fluorinated emulsions exist in a large temperature domain (between 10 and 50 degrees C). The study of the phase behavior reveals that the continuous medium composition varied with the temperature. Highly concentrated emulsions behave as elastic solids. Monitoring the evolution of their elasticity with time as a function of temperature by rheology is an original way to characterize their aging. This method was used to get more insight into the modification of the behavior of polydisperse emulsions with temperature and time. The elastic modulus decreased exponentially with time in the range of temperatures studied. This was interpreted as a result of coalescence due to a single film rupture frequency which was independent of its thickness. This coalescence mechanism is thermally activated with an activation energy of 50 k(B)T. Copyright 1999 Academic Press.

Characterization of echoviruses that bind decay accelerating factor (CD55): evidence that some haemagglutinating strains use more than one cellular receptor

Several echoviruses (EVs) have previously been shown to use decay accelerating factor (DAF) as a cellular receptor. Since DAF is expressed on erythrocytes, EVs that use this receptor cause haemagglutination. Here we show that all EVs that haemagglutinate do so via attachment to DAF and that this interaction can be inhibited by a monoclonal antibody (MAb) specific for DAF domain SCR3. Although the viruses haemagglutinate via DAF some can bind to rhabdomyosarcoma cells from which DAF has been removed and infect in the presence of a MAb against DAF. This suggests that some EVs have the capacity to interact with more than one cellular receptor.

Confinement of dilute solutions of living polymers

We investigate the thermodynamic properties of a dilute solution of living polymers confined between two solid repulsive walls. We consider both the case of rigid and of flexible macromolecules. When the confined system is taken to be at equilibrium with an external reservoir the living polymers behave similarly to a polydisperse solution of unbreakable chains. However for closed gaps the behaviour is quite different from a classical polymer solution because the worm-like micelles can adapt their intrinsic polydispersity in order to release the confinement constraint. In particular, for rigid living polymers this leads to a divergence of the average chain-length in the limit of strong confinement, as well as to a non-monotonic behaviour of the pressure acting on the walls.

[Obstructive disorders of urine transport in the upper urinary tract--vascular and inflammatory causes]

Vascular and inflammatory causes of ureteral obstruction may be difficult in diagnosis and are recognized often too late. Symptoms, diagnostic approach and therapeutic measures are described in detail.

Fluid phase generation of terminal complement complex as a novel index of bioincompatibility

Blood membrane interactions in hemodialysis have been shown to trigger complement (C) activation. As indicators of C-activation the anaphylatoxins (C3a and C5a) are problematical because of methodological difficulties and their kinetic properties. We developed a sensitive and specific micro-ELISA using a monoclonal antibody against neoantigens on the terminal complement complex (TCC); highly purified human TCC served as standard. Concentrations of TCC were measured in single-path perfusion systems (in vitro) and in the blood lines (arterial inlet; venous outlet) of patients on hemodialysis using steam-sterilized or ETO-sterilized dialyzers with the following membranes: cuprophan (CU), hemophan (HE) and polysulfone F6 (PS), respectively. All dialyzers with identical geometry were run under identical conditions. All membranes tested caused continuously ongoing net generation of TCC. In vitro, contact of serum with CU minidialyzers resulted in fivefold higher net release of TCC compared with HE and PS. In vivo TCC concentration-time profiles differed significantly between membranes in the rank order CU much much greater than HE greater than PS (mean basal concentration 58 x 10(-11) M; peak increase over baseline with CU 40-fold, HE fourfold, PS threefold). In addition, more TCC was generated from the same dialyzers with ETO than steam sterilization. TCC differed from C3a and C5a in the following respects: (i) lower detection limit (4 x 10(-11) vs. less than 5 x 10(-9) M for both C-anaphylatoxins); (ii) higher relative increment (inlet) during CU dialysis (25-fold vs. eightfold and twofold, respectively); (iii) C-anaphylatoxins yielded the same ranking (CU much greater than HE greater than PS), but TCC concentrations were not a linear function of C3a or C5a concentrations, respectively. Kinetic analysis (Bateman function) showed significant differences of invasion constants between membranes, that is, CU 0.088 min-1, HE 0.09, PS 0.168. The net amount of TCC released from the dialyzer was calculated under certain assumptions. It was 75.5 mg/4 hr for CU, 7.3 for HE and 5.0 for PS. The elimination constant was also dependent on the type of membrane. Using flow cytofluorometry and immunohistochemical methods (APAAP), TCC was demonstrated on membranes of granulocytes obtained during dialysis; this is compatible with potential in vivo cell activation. Generation of PGE2 and TNF alpha by adherent monocytes induced by cuprophan was C8 dependent: levels were significantly increased by addition of C8 to C8 deficient human serum concomitantly with generation of TCC.(ABSTRACT TRUNCATED AT 250 WORDS)