Early stages of polycrystalline diamond deposition: laser reflectance at substrates with growing nanodiamonds.

The chemical vapor deposition of polycrystalline diamond (PCD) films is typically done on substrates seeded with diamond nanoparticles. Specular laser reflectance has been used in tandem with a continuous film model to monitor the thickness of these films during their deposition. However, approaches to gain information on properties that strongly affect film morphology, such as the areal density of seeds, remain largely unexplored. This work outlines a strategy for using laser reflectance measurements to refine the monitoring of film thickness during deposition, estimate the mean equivalent radii and the areal density of seeds, and estimate growth incubation periods. We present a general model based on the Rayleigh theory of scattering for laser reflectance at substrates with growing nanoparticles that captures the early stages of PCD deposition. We test our model experimentally by depositing diamond under identical conditions on silicon substrates with various seed densities and by comparing seed densities obtained by scanning electron microscopy to those determined by our strategy. We also explore the different deposition stages for which our model and a continuous film model can be used safely. In addition to providing guidelines for characterizing PCD deposition, this work may also advance the general understanding of nanoparticle growth and formation.

Block copolymer-nanodiamond coassembly in solution: towards multifunctional hybrid materials.

Polymer-nanodiamond composites are excellent candidates for the fabrication of multifunctional hybrid materials. They integrate polymer flexibility and exceptional properties of nanodiamonds (NDs), such as biocompatibility, mechanical strength, color centers, and chemically-tailored surfaces. However, their development is hindered by the challenge of ensuring that NDs are homogeneously distributed in the composites. Here, we exploit colloidal coassembly between poly(isoprene-b-styrene-b-2-vinyl pyridine) (ISV) block copolymers (BCPs) and NDs to avoid ND self-agglomeration and direct ND spatial distribution. NDs were first air oxidized at 450 °C to obtain stable dispersions in dimethylacetamide (DMAc). By adding ISV into the dispersions, patchy hybrid micelles were formed due to H-bonds between NDs and ISV. The ISV-ND coassembly in DMAc was then used to fabricate nanocomposite films with a uniform sub-50 nm ND distribution, which has never been previously reported for an ND loading (φND) of more than 50 wt%. The films exhibit good transparency due to their well-defined nanostructures and smoothness and also exhibit an improved UV-absorption and hydrophilicity compared to neat ISV. More intriguingly, at a φND of 22 wt%, ISV and NDs coassemble into a network-like superstructure with well-aligned ND strings via a dialysis method. Transmission electron microscopy and dynamic light scattering measurements suggest a complex interplay between polymer-polymer, polymer-solvent, polymer-ND, ND-solvent, and ND-ND interactions during the formation of structures. Our work may provide an important foundation for the development of hierarchically ordered nanocomposites based on BCP-ND coassembly, which is beneficial for a wide spectrum of applications from biotechnology to quantum devices.

Correction to: MRI assessment of the thigh musculature in dermatomyositis and healthy subjects using diffusion tensor imaging, intravoxel incoherent motion and dynamic DTI.

The original version of this article, published on 04 June 2018, unfortunately contained a mistake.

MRI assessment of the thigh musculature in dermatomyositis and healthy subjects using diffusion tensor imaging, intravoxel incoherent motion and dynamic DTI.

INTRODUCTION: Dermatomyositis (DM) is an idiopathic inflammatory myopathy involving severe debilitation in need of diagnostics. We evaluated the proximal lower extremity musculature with diffusion tensor imaging (DTI), intravoxel incoherent motion (IVIM) and dynamic DTI in DM patients and controls and compared with standard clinical workup. METHODS: In this IRB-approved, HIPAA-compliant study with written informed consent, anatomical, Dixon fat/water and diffusion imaging were collected in bilateral thigh MRI of 22 controls and 27 DM patients in a 3T scanner. Compartments were scored on T1/T2 scales. Single voxel dynamic DTI metrics in quadriceps before and after 3-min leg exercise were measured. Spearman rank correlation and mixed model analysis of variance/covariance (ANOVA/ANCOVA) were used to correlate with T1 and T2 scores and to compare patients with controls. RESULTS: DM patients showed significantly lower pseudo-diffusion and volume in quadriceps than controls. All subjects showed significant correlation between T1 score and signal-weighted fat fraction; tissue diffusion and pseudo-diffusion varied significantly with T1 and T2 score in patients. Radial and mean diffusion exercise response in patients was significantly higher than controls. CONCLUSION: Static and dynamic diffusion imaging metrics show correlation with conventional imaging scores, reveal spatial heterogeneity, and provide means to differentiate dermatomyositis patients from controls. KEY POINTS: • Diffusion imaging shows regional differences between thigh muscles of dermatomyositis patients and controls. • Signal-weighted fat fraction and diffusion metrics correlate with T1/T2 scores of disease severity. • Dermatomyositis patients show significantly higher radial diffusion exercise response than controls.

Spatially resolved kinetics of skeletal muscle exercise response and recovery with multiple echo diffusion tensor imaging (MEDITI): a feasibility study.

OBJECTIVES: We describe measurement of skeletal muscle kinetics with multiple echo diffusion tensor imaging (MEDITI). This approach allows characterization of the microstructural dynamics in healthy and pathologic muscle. MATERIALS AND METHODS: In a Siemens 3-T Skyra scanner, MEDITI was used to collect dynamic DTI with a combination of rapid diffusion encoding, radial imaging, and compressed sensing reconstruction in a multi-compartment agarose gel rotation phantom and within in vivo calf muscle. An MR-compatible ergometer (Ergospect Trispect) was employed to enable in-scanner plantar flexion exercise. In a HIPAA-compliant study with written informed consent, post-exercise recovery of DTI metrics was quantified in eight volunteers. Exercise response of DTI metrics was compared with that of T2-weighted imaging and characterized by a gamma variate model. RESULTS: Phantom results show quantification of diffusivities in each compartment over its full dynamic rotation. In vivo calf imaging results indicate larger radial than axial exercise response and recovery in the plantar flexion-challenged gastrocnemius medialis (fractional response: nT2w = 0.385 ± 0.244, nMD = 0.163 ± 0.130, nλ1 = 0.110 ± 0.093, nλrad = 0.303 ± 0.185). Diffusion and T2-weighted response magnitudes were correlated (e.g., r = 0.792, p = 0.019 for nMD vs. nT2w). CONCLUSION: We have demonstrated the feasibility of MEDITI for capturing spatially resolved diffusion tensor data in dynamic systems including post-exercise skeletal muscle recovery following in-scanner plantar flexion.

Legislation of direct-to-consumer genetic testing in Europe: a fragmented regulatory landscape.

Despite the increasing availability of direct-to-consumer (DTC) genetic testing, it is currently unclear how such services are regulated in Europe, due to the lack of EU or national legislation specifically addressing this issue. In this article, we provide an overview of laws that could potentially impact the regulation of DTC genetic testing in 26 European countries, namely Austria, Belgium, Cyprus, the Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Ireland, Italy, Latvia, Lithuania, Luxembourg, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, the Netherlands and the United Kingdom. Emphasis is placed on provisions relating to medical supervision, genetic counselling and informed consent. Our results indicate that currently there is a wide spectrum of laws regarding genetic testing in Europe. There are countries (e.g. France and Germany) which essentially ban DTC genetic testing, while in others (e.g. Luxembourg and Poland) DTC genetic testing may only be restricted by general laws, usually regarding health care services and patients' rights.

Photocurrent generation in diamond electrodes modified with reaction centers.

Photoactive reaction centers (RCs) are protein complexes in bacteria able to convert sunlight into other forms of energy with a high quantum yield. The photostimulation of immobilized RCs on inorganic electrodes result in the generation of photocurrent that is of interest for biosolar cell applications. This paper reports on the use of novel electrodes based on functional conductive nanocrystalline diamond onto which bacterial RCs are immobilized. A three-dimensional conductive polymer scaffold grafted to the diamond electrodes enables efficient entrapment of photoreactive proteins. The electron transfer in these functional diamond electrodes is optimized through the use of a ferrocene-based electron mediator, which provides significant advantages such as a rapid electron transfer as well as high generated photocurrent. A detailed discussion of the generated photocurrent as a function of time, bias voltage, and mediators in solution unveils the mechanisms limiting the electron transfer in these functional electrodes. This work featuring diamond-based electrodes in biophotovoltaics offers general guidelines that can serve to improve the performance of similar devices based on different materials and geometries.

Contactless photoconductance study on undoped and doped nanocrystalline diamond films.

Hydrogen and oxygen surface-terminated nanocrystalline diamond (NCD) films are studied by the contactless time-resolved microwave conductivity (TRMC) technique and X-ray photoelectron spectroscopy (XPS). The optoelectronic properties of undoped NCD films are strongly affected by the type of surface termination. Upon changing the surface termination from oxygen to hydrogen, the TRMC signal rises dramatically. For an estimated quantum yield of 1 for sub-bandgap optical excitation the hole mobility of the hydrogen-terminated undoped NCD was found to be ∼0.27 cm(2)/(V s) with a lifetime exceeding 1 µs. Assuming a similar mobility for the oxygen-terminated undoped NCD a lifetime of ∼100 ps was derived. Analysis of the valence band spectra obtained by XPS suggests that upon oxidation of undoped NCD the surface Fermi level shifts (toward an increased work function). This shift originates from the size and direction of the electronic dipole moment of the surface atoms, and leads to different types of band bending at the diamond/air interface in the presence of a water film. In the case of boron-doped NCD no shift of the work function is observed, which can be rationalized by pinning of the Fermi level. This is confirmed by TRMC results of boron-doped NCD, which show no dependency on the surface termination. We suggest that photoexcited electrons in boron-doped NCD occupy nonionized boron dopants, leaving relatively long-lived mobile holes in the valence band.

Evidence for phase separation of ethanol-water mixtures at the hydrogen terminated nanocrystalline diamond surface.

Interactions between ethanol-water mixtures and a hydrophobic hydrogen terminated nanocrystalline diamond surface, are investigated by sessile drop contact angle measurements. The surface free energy of the hydrophobic surface, obtained with pure liquids, differs strongly from values obtained by ethanol-water mixtures. Here, a model which explains this difference is presented. The model suggests that, due to a higher affinity of ethanol for the hydrophobic surface, when compared to water, a phase separation occurs when a mixture of both liquids is in contact with the H-terminated diamond surface. These results are supported by a computational study giving insight in the affinity and related interaction at the liquid-solid interface.

Local boron environment in B-doped nanocrystalline diamond films.

Thin films of heavily B-doped nanocrystalline diamond (B:NCD) have been investigated by a combination of high resolution annular dark field scanning transmission electron microscopy and spatially resolved electron energy-loss spectroscopy performed on a state-of-the-art aberration corrected instrument to determine the B concentration, distribution and the local B environment. Concentrations of ~1 to 3 at.% of boron are found to be embedded within individual grains. Even though most NCD grains are surrounded by a thin amorphous shell, elemental mapping of the B and C signal shows no preferential embedding of B in these amorphous shells or in grain boundaries between the NCD grains, in contrast with earlier work on more macroscopic superconducting polycrystalline B-doped diamond films. Detailed inspection of the fine structure of the boron K-edge and comparison with density functional theory calculated fine structure energy-loss near-edge structure signatures confirms that the B atoms present in the diamond grains are substitutional atoms embedded tetrahedrally into the diamond lattice.

Heat-transfer resistance at solid-liquid interfaces: a tool for the detection of single-nucleotide polymorphisms in DNA.

In this article, we report on the heat-transfer resistance at interfaces as a novel, denaturation-based method to detect single-nucleotide polymorphisms in DNA. We observed that a molecular brush of double-stranded DNA grafted onto synthetic diamond surfaces does not notably affect the heat-transfer resistance at the solid-to-liquid interface. In contrast to this, molecular brushes of single-stranded DNA cause, surprisingly, a substantially higher heat-transfer resistance and behave like a thermally insulating layer. This effect can be utilized to identify ds-DNA melting temperatures via the switching from low- to high heat-transfer resistance. The melting temperatures identified with this method for different DNA duplexes (29 base pairs without and with built-in mutations) correlate nicely with data calculated by modeling. The method is fast, label-free (without the need for fluorescent or radioactive markers), allows for repetitive measurements, and can also be extended toward array formats. Reference measurements by confocal fluorescence microscopy and impedance spectroscopy confirm that the switching of heat-transfer resistance upon denaturation is indeed related to the thermal on-chip denaturation of DNA.

A positive caver map response poorly predicts recovery of potency after radical prostatectomy.

OBJECTIVES: To determine whether preservation of the neurovascular bundles (NVBs), defined by a positive CaverMap response, correlates with the recovery of potency after radical prostatectomy. METHODS: We studied a group of 60 men who were potent preoperatively who underwent radical retropubic prostatectomy by one surgeon. The CaverMap was used after removal of the prostate to assess the integrity of the NVBs. Postoperative potency was assessed by a postal questionnaire and telephone interview, administered independently of the treating surgeon. Men were considered potent if they reported postoperative erections consistently sufficient for vaginal penetration with or without the use of sildenafil. RESULTS: The mean patient age was 59 years, and the median follow-up was 365 days. A positive CaverMap response was obtained in 73 (77%) of the 95 NVBs tested. The overall potency rate was 18%. No patients with a bilateral negative CaverMap response were potent, and 2 (22%) of 9 with a unilateral CaverMap response (negative versus unilateral response, P = 0.46) and 6 (27%) of 22 with bilateral CaverMap responses (negative versus bilateral response, P = 0.32) were potent. CONCLUSIONS: A positive CaverMap response, suggesting that a successful nerve-sparing prostatectomy had been performed, was obtained in 77% of the NVBs tested. Nevertheless, with a median follow-up of 12 months, most patients with a positive CaverMap response remained impotent. This suggests that other factors are critical to the recovery of sexual function after radical prostatectomy.

Effect of future costs on cost-effectiveness of medical interventions among young adults: the example of intensive therapy for type 1 diabetes mellitus.

OBJECTIVES: Recent research based on a lifetime utility maximization model has suggested that cost-effectiveness analyses should account for all future costs, including medical costs for related and unrelated illnesses and nonmedical costs. This work has also shown that analyses that omit future costs are biased to favor interventions among the elderly that extend life over interventions that improve quality of life. However, the effect of including future costs on the cost-effectiveness of interventions among the young has not been studied. This article examines the effect of including future costs on the cost-effectiveness of intensive therapy for type 1 diabetes mellitus among young adults. METHODS: By modifying a cost-effectiveness model based on the Diabetes Control and Complications Trial to include future costs, the effect of including future costs on the cost-effectiveness of intensive therapy for type 1 diabetes mellitus among young adults was examined. Future costs added to the model included future costs for medical expenditures for illnesses unrelated to diabetes and future nonmedical expenditures net of earnings. RESULTS: Intensive therapy among young adults led to approximately equal increases in the expected number of years lived before age 65, when people generally produce more than they consume, and after age 65, when the opposite tends to hold. Because the discounted value of savings due to lower mortality before age 65 exceeded the discounted value of later increases in costs due to lower mortality after age 65, accounting for future costs decreased the cost-effectiveness ratio from $22,576 to $9,626 per quality-adjusted life-year. CONCLUSIONS: The inclusion of future costs can significantly improve the cost-effectiveness of interventions that decrease mortality among young adults. The common practice of excluding future costs may bias cost-effectiveness analyses against such interventions.

P2-purinoceptors on postganglionic sympathetic neurones.

1. Postganglionic sympathetic neurones possess both excitatory and inhibitory P2-purinoceptors. 2. The mechanisms of action of excitatory P2-purinoceptors have recently been studied on cultured sympathetic neurones of the rat. The receptors mediate fast increases in intracellular Ca2+ levels and a release of noradrenaline. They are likely to belong to the neuronal types of P2X-purinoceptors and to be located on the sympathetic nerve cell bodies or their dendrites. 3. Inhibitory P2-purinoceptors have been shown to operate at sympathetic axon terminals in isolated tissues. Adenine nucleotides decreased the stimulation-evoked release of noradrenaline by activation of these receptors. The receptors are likely to belong to the group of G-protein-coupled P2Y-purinoceptors. They mediate a negative feedback in which co-transmitter ATP inhibits subsequent sympathetic transmitter release.

P2-purinoceptor-mediated inhibition of noradrenaline release in rat atria.

1. We looked for P2-purinoceptors modulating noradrenaline release in rat heart atria. Segments of the atria were preincubated with [3H]-noradrenaline and then superfused with medium containing desipramine (1 microM) and yohimbine (1 microM) and stimulated electrically, by 30 pulses/1 Hz unless stated otherwise. 2. The adenosine A1-receptor agonist, N6-cyclopentyl-adenosine (CPA; EC50 9.7 nM) and the nucleotides, ATP (EC50 6.6 microM) and adenosine-5'-O-(3-thiotriphosphate) (ATP gamma S; EC50 4.8 microM), decreased the evoked overflow of tritium. The adenosine A2a-agonist, 2-p-(2-carbonylethyl)-phenethylamino-5'-N-ethylcarboxamido-a denosine (CGS-21680; 0.03-0.3 microM) and the P2x-purinoceptor agonist beta, gamma-methylene-L-ATP (30 microM) caused no change. 3. The concentration-response curve of CPA was shifted to the right by the adenosine A1-receptor antagonist, 8-cyclopentyl-1,3-dipropyl-xanthine (DPCPX; 3 nM; apparent pKB value 9.7) but hardly affected by the P2-purinoceptor antagonist, cibacron blue 3GA (30 microM). In contrast, the concentration-response curves of ATP and ATP gamma S were shifted to the right by DPCPX (3 nM; apparent pKB values 9.3 and 9.4, respectively) as well as by cibacron blue 3GA (30 microM; apparent pKB values 5.0 and 5.1, respectively). Combined administration of DPCPX and cibacron blue 3GA caused a much greater shift of the concentration-response curve of ATP than either antagonist alone. The concentration-response curve of ATP was not changed by indomethacin, atropine or the 5'-nucleotidase blocker alpha, beta-methylene-ADP. 4. Cibacron blue 3GA (30 microM) increased the evoked overflow of tritium by about 70%. The increase was smaller when the slices were stimulated by 9 pulses/O00 Hz instead of 30 pulses/I Hz.5. The results indicate that the postganglionic sympathetic axons in rat atria possess P2-purinoceptors in addition to the known adenosine Al-receptor. Both mediate inhibition of noradrenaline release. Some adenine nucleotides such as ATP and ATP gamma S act at both receptors. The presynaptic P2-purinoceptor seems to be activated by an endogenous ligand, presumably ATP, under the condition of these experiments. This is the first evidence for presynaptic P2-purinoceptors at cardiac postganglionic sympathetic axons.

[Liver injuries]. / Leberverletzungen.

Mortality in blunt hepatic trauma is still high, death being most frequently caused by hemorrhage. Associated injuries are present in nearly all cases. A variety of possible surgical procedures allow treatment tailored to fit the individual situation. Even the sophisticated intensive care required by the frequent posttraumatic complications is not a substitute for adequate surgery.

Polyvalent immunoglobulins for prophylaxis of bacterial infections in patients following multiple trauma. A randomized, placebo-controlled study.

One hundred and fifty severely injured patients requiring long-term artificial ventilation were evaluated in a prospective, randomized, double blind study comparing the prophylactic effect of an intravenous immunoglobulin (Sandoglobulin; IGIV) against nosocomial infections with a placebo preparation. The groups were comparable in age, sex, injury pattern, and severity of the trauma. Seventy-six patients received 12 g of Sandoglobulin as a 3% solution on day 0, day 5 and day 12, i.e. a total of 36 g. Sandoglobulin significantly reduced the incidence of pneumonia (28 cases in the IGIV group, 43 cases in the placebo group, p = 0.0111). This resulted in a reduced therapeutic use of antibiotics. For the occurrence of sepsis (IGIV: 14 cases; placebo 19 cases) and other infections (IGIV: 11 cases; placebo: 10 cases) no significant differences were found. No side effects of the administration of IGIV were observed. IGIV prophylaxis neither reduced the overall death rate nor those deaths caused by infection. On day 5 after administration of the first 12 g of IGIV, the IgG serum concentrations were significantly higher in the Sandoglobulin group (8.41 +/- 1.96 mg/ml and 7.42 +/- 2.25 mg/ml respectively, p less than 0.001) whereas later serum samples showed no significant differences.