Long term outcome after treatment of de novo coronary artery lesions using three different drug coated balloons.

OBJECTIVE: To evaluate the long-term efficacy of three currently available drug coated balloons (DCB) for the treatment of de-novo coronary lesions. METHODS: This was a retrospective analysis of prospectively collected data from the Swedish Coronary Angiography and Angioplasty Registry. Between 2009 and 2017, three currently available DCB brands used in the treatment of de novo lesions were included. Outcomes were clinically driven restenosis and target lesion thrombosis (TLT) (per device) and major adverse cardiac events (MACE) including death, myocardial infarction or target vessel revascularization (per patient) at 4 years. Multivariable Cox regression models were used to adjust for differences. RESULTS: We included 6715 lesions treated with DCBs, 4483 SeQuent® Please (S-DCB), 1071 IN.PACT Falcon (I-DCB) and 1161 Pantera® Lux (P-DCB), in 5670 patients. The mean DCB diameter was 2.4 mm. Bailout stenting occurred in 6.7% of lesions. Angiographic success was 98.5%. The overall cumulative rate of restenosis was 5.5% (299 events). The risk for reported restenosis did not significantly differ between I-DCB vs S-DCB, adjusted hazard ratio (aHR) 0.96; 95% confidence interval (CI) 0.69-1.34, P-DCB vs S-DCB aHR 0.88; 95% CI 0.63-1.23 and I-DCB vs P-DCB aHR 1.10; 95% CI 0.72-1.68. The cumulative risk for TLT was 0.8% in all three DCBs. The risk for MACE or individual components of MACE did not differ between the three patient-groups. CONCLUSION: In de novo coronary lesions, we found comparable long-term efficacy with three currently available DCB brands. DCB angioplasty was feasible with low risk for long-term restenosis and TLT.

Enhanced thermal conduction by surface phonon-polaritons.

Improving heat dissipation in increasingly miniature microelectronic devices is a serious challenge, as the thermal conduction in nanostructures is markedly reduced by increasingly frequent scattering of phonons on the surface. However, the surface could become an additional heat dissipation channel if phonons couple with photons forming hybrid surface quasiparticles called surface phonon-polaritons (SPhPs). Here, we experimentally demonstrate the formation of SPhPs on the surface of SiN nanomembranes and subsequent enhancement of heat conduction. Our measurements show that the in-plane thermal conductivity of membranes thinner than 50 nm doubles up as the temperature rises from 300 to 800 kelvin, while thicker membranes show a monotonic decrease. Our theoretical analysis shows that these thickness and temperature dependencies are fingerprints of SPhP contribution to heat conduction. The demonstrated thermal transport by SPhPs can be useful as a previously unidentified channel of heat dissipation in a variety of fields including microelectronics and silicon photonics.

Heat transfer in rough nanofilms and nanowires using full band ab initio Monte Carlo simulation.

The Boltzmann transport equation is one of the most relevant frameworks to study the heat transport at the nanoscale, beyond the diffusive regime and up to the micrometer-scale. In the general case of 3D devices, the particle Monte Carlo approach of phonon transport is particularly powerful and convenient, and requires reasonable computational resources. In this work, we propose an original and versatile particle Monte Carlo approach parametrized by using ab initio data. Both the phonon dispersion and the phonon-phonon scattering rates have been computed by DFT calculation in the entire 3D Brillouin zone. To treat the phonon transport at rough interfaces, a combination of specular and diffuse reflections has been implemented in phase space. Thermal transport has been investigated in nanowires and thin films made of cubic and hexagonal Silicon, including edge roughness, in terms of effective thermal conductivity, phonon band contributions and heat flux orientation. It is shown that the effective thermal conductivity in quasi-ballistic regime obtained from our Monte Carlo simulation cannot be accurately fitted by simple semi-analytical Matthiessen-like models and that spectral approaches are mandatory to get good results. Our full band approach shows that some phonon branches exhibiting a negative group velocity in some parts of the Brillouin zone may contribute negatively to the total thermal flux. Besides, the thermal flux clearly appears to be oriented along directions of high density of states. The resulting anisotropy of the heat flux is discussed together with the influence of rough interfaces.

Thermal conductivity and air-mediated losses in periodic porous silicon membranes at high temperatures.

Heat conduction in silicon can be effectively engineered by means of sub-micrometre porous thin free-standing membranes. Tunable thermal properties make these structures good candidates for integrated heat management units such as waste heat recovery, rectification or efficient heat dissipation. However, possible applications require detailed thermal characterisation at high temperatures which, up to now, has been an experimental challenge. In this work we use the contactless two-laser Raman thermometry to study heat dissipation in periodic porous membranes at high temperatures via lattice conduction and air-mediated losses. We find the reduction of the thermal conductivity and its temperature dependence closely correlated with the structure feature size. On the basis of two-phonon Raman spectra, we attribute this behaviour to diffuse (incoherent) phonon-boundary scattering. Furthermore, we investigate and quantify the heat dissipation via natural air-mediated cooling, which can be tuned by engineering the porosity.Nanostructuring of silicon allows acoustic phonon engineering, but the mechanism of related thermal transport in these structures is not fully understood. Here, the authors study the heat dissipation in silicon membranes with periodic nanoholes and show the importance of incoherent scattering.

Spectral mapping of heat transfer mechanisms at liquid-solid interfaces.

Thermal transport through liquid-solid interfaces plays an important role in many chemical and biological processes, and better understanding of liquid-solid energy transfer is expected to enable improving the efficiency of thermally driven applications. We determine the spectral distribution of thermal current at liquid-solid interfaces from nonequilibrium molecular dynamics, delivering a detailed picture of the contributions of different vibrational modes to liquid-solid energy transfer. Our results show that surface modes located at the Brillouin zone edge and polarized along the liquid-solid surface normal play a crucial role in liquid-solid energy transfer. Strong liquid-solid adhesion allows also for the coupling of in-plane polarized modes in the solid with the liquid, enhancing the heat-transfer rate and enabling efficient energy transfer up to the cutoff frequency of the solid. Our results provide fundamental understanding of the energy-transfer mechanisms in liquid-solid systems and enable detailed investigations of energy transfer between, e.g., water and organic molecules.

Tunable thermal conductivity of thin films of polycrystalline AlN by structural inhomogeneity and interfacial oxidation.

The effect of the structural inhomogeneity and oxygen defects on the thermal conductivity of polycrystalline aluminum nitride (AlN) thin films deposited on single-crystal silicon substrates is experimentally and theoretically investigated. The influence of the evolution of crystal structure, grain size, and out-of plane disorientation along the cross plane of the films on their thermal conductivity is analyzed. The impact of oxygen-related defects on thermal conduction is studied in AlN/AlN multilayered samples. Microstructure, texture, and grain size of the films were characterized by X-ray diffraction and scanning and transmission electron microscopy. The measured thermal conductivity obtained with the 3-omega technique for a single and multiple layers of AlN is in fairly good agreement with the theoretical predictions of our model, which is developed by considering a serial assembly of grain distributions. An effective thermal conductivity of 5.92 W m(-1) K(-1) is measured for a 1107.5 nm-thick multilayer structure, which represents a reduction of 20% of the thermal conductivity of an AlN monolayer with approximately the same thickness, due to oxygen impurities at the interface of AlN layers. Our results show that the reduction of the thermal conductivity as the film thickness is scaled down, is strongly determined by the structural inhomogeneities inside the sputtered films. The origin of this non-homogeneity and the effect on phonon scattering are also discussed.

Making better doctors: a survey of premedical interns working as health coaches.

We operate a decision support program in a medical center in San Francisco. In this program, postbaccalaureate, premedical interns deliver decision and communication, aids to patients. We asked whether working in this program helped these premedical interns develop key physician competencies. To measure physician competencies, we adopted the standards of the Accreditation Committee on Graduate Medical Education (ACGME), which accredits residency programs in the USA. The ACGME competencies are patient care, medical knowledge, practice-based learning, interpersonal and communication skills, professionalism, and systems-based practice. We developed a survey for our program alumni to rate themselves on a scale from 0 (none) to 100 (perfect) on each competency, before and after their time in our program. The survey also solicited free-text comments regarding each competency. In June 2012, we e-mailed all 47 alumni a link to our online survey and then analyzed responses received by July 15, 2012. We visually explored the distributions of ratings and compared medians. We selected the most specific and concrete comments from the qualitative responses. Respondents (21/47 or 45%) reported that their participation in Decision Services increased their competencies across the board. Qualitative comments suggest that this is because students accompanied patients on their clinic journeys (seeing multiple facets of the systems of care) while also actively facilitating patient physician communication. Providing decision support can improve self-ratings of crucial physician competencies. Educators should consider deploying premedical and medical students as decision support coaches to increase competencies through experiential learning.

Blood pressure changes after renal denervation at 10 European expert centers.

We did a subject-level meta-analysis of the changes (Δ) in blood pressure (BP) observed 3 and 6 months after renal denervation (RDN) at 10 European centers. Recruited patients (n=109; 46.8% women; mean age 58.2 years) had essential hypertension confirmed by ambulatory BP. From baseline to 6 months, treatment score declined slightly from 4.7 to 4.4 drugs per day. Systolic/diastolic BP fell by 17.6/7.1 mm Hg for office BP, and by 5.9/3.5, 6.2/3.4, and 4.4/2.5 mm Hg for 24-h, daytime and nighttime BP (P0.03 for all). In 47 patients with 3- and 6-month ambulatory measurements, systolic BP did not change between these two time points (P0.08). Normalization was a systolic BP of <140 mm Hg on office measurement or <130 mm Hg on 24-h monitoring and improvement was a fall of 10 mm Hg, irrespective of measurement technique. For office BP, at 6 months, normalization, improvement or no decrease occurred in 22.9, 59.6 and 22.9% of patients, respectively; for 24-h BP, these proportions were 14.7, 31.2 and 34.9%, respectively. Higher baseline BP predicted greater BP fall at follow-up; higher baseline serum creatinine was associated with lower probability of improvement of 24-h BP (odds ratio for 20-µmol l(-1) increase, 0.60; P=0.05) and higher probability of experiencing no BP decrease (OR, 1.66; P=0.01). In conclusion, BP responses to RDN include regression-to-the-mean and remain to be consolidated in randomized trials based on ambulatory BP monitoring. For now, RDN should remain the last resort in patients in whom all other ways to control BP failed, and it must be cautiously used in patients with renal impairment.

Informational needs of patients with metastatic breast cancer: what questions do they ask, and are physicians answering them?

In the setting of breast oncology consultations, we sought to understand communication patterns between patients with advanced breast cancer and their oncologists during visits with Decision Support Services. This is a descriptive study analyzing themes and their frequencies of premeditated question lists of patients with metastatic breast cancer. We identified topics physicians most commonly discussed among themes previously found, documenting questions patients with metastatic breast cancer prepare for physician consultations and oncologists' response. Inclusion criteria were as follows: diagnosis of metastatic breast cancer, completion of a question list before meeting with an oncologist, and receipt of a summary of the consultation. We identified 59 women with metastatic breast cancer who received both documents. We reviewed the question lists and consultation summaries of these patients. Of the 59 patients whose documents we reviewed, patients most often asked about prognosis (38), symptom management (31), clinical trials (43), and quality of life (38). Physicians answered questions about prognosis infrequently (37% of the time); other questions that were answered more than commonly are the following: symptom management (81%), clinical trials (79%), and quality of life (66%). Breast cancer patients have many questions regarding their disease, its treatment, and symptoms, which were facilitated in this setting by Decision Support Services. Question lists may be insufficient to bridge the divide between physicians and patient information needs in the setting of metastatic breast cancer, particularly regarding prognosis. Patients may need additional assistance defining question lists, and physicians may benefit from training in communication, particularly regarding discussions of prognosis and end of life.

Ballistic thermal conductance of a lab-in-a-TEM made Si nanojunction.

The thermal conductance of a single silicon nanojunction was measured based on a Lab-in-a-TEM (microelectromechanical systems in a transmission electron microscope) technique and was found to be at least 2 orders of magnitude larger than the ones of long nanowires in the 380-460 K temperature range. The predominance of ballistic phonon transport appears as the best hypothesis to retrieve quantitative predictions despite the geometrical irregularity of the junction. The measurement is based on a MEMS structure including an electrostatic actuator that allows producing nanojunctions with the accuracy based on the resolution of a transmission electron microscope. The thermal conductance is measured by two integrated resistors that are simultaneously heating and measuring the local temperatures at the nearest of the nanojunction. The considerable thermal conductance of short nanojunctions constitutes a new key element in the design of nanosystems and in the understanding of the damaging of mechanical micronanocontacts. This conducting behavior is also paving the way for the development of nanoscale cooling devices as well as of the recent phononic information technology.

Physician behaviors surrounding the implementation of decision and communication AIDS in a breast cancer clinic: a qualitative analysis of staff intern perceptions.

The aim of this paper is to examine how physician behavior facilitated or impeded our implementation of decision and communication aids in a breast cancer clinic. Staff interns provided decision and communication aids to patients and wrote up case notes for each patient they served. We used grounded theory to code our staff interns' case notes. We then identified barriers and facilitators to our program's implementation from each category we generated in the coding. Facilitators included physicians reading patient questions and then bringing the staff interns to the consultation. Barriers included physicians forgetting to bring the staff interns to the appointments and discouraging interns from speaking during the consultation. Physicians vary in their cooperation with our program. Our next steps will be to inquire directly with physicians about how to adapt our program design. We will also seek to position the staff interns as mentees to increase physician commitment to our program.

Age-related changes of cerebral autoregulation: new insights with quantitative T2'-mapping and pulsed arterial spin-labeling MR imaging.

BACKGROUND AND PURPOSE: Cerebral perfusion and O(2) metabolism are affected by physiologic age-related changes. High-resolution motion-corrected quantitative T2'-imaging and PASL were used to evaluate differences in deoxygenated hemoglobin and CBF of the gray matter between young and elderly healthy subjects. Further combined T2'-imaging and PASL were investigated breathing room air and 100% O(2) to evaluate age-related changes in cerebral autoregulation. MATERIALS AND METHODS: Twenty-two healthy volunteers 60-88 years of age were studied. Two scans of high-resolution motion-corrected T2'-imaging and PASL-MR imaging were obtained while subjects were either breathing room air or breathing 100% O(2). Manual and automated regions of interest were placed in the cerebral GM to extract values from the corresponding maps. Results were compared with those of a group of young healthy subjects previously scanned with the identical protocol as that used in the present study. RESULTS: There was a significant decrease of cortical CBF (P < .001) and cortical T2' values (P < .001) between young and elderly healthy subjects. In both groups, T2' remained unchanged under hyperoxia compared with normoxia. Only in the younger but not in the elderly group could a significant (P = .02) hyperoxic-induced decrease of the CBF be shown. CONCLUSIONS: T2'-mapping and PASL in the cerebral cortex of healthy subjects revealed a significant decrease of deoxygenated hemoglobin and of CBF with age. The constant deoxyHb level breathing 100% O(2) compared with normoxia in young and elderly GM suggests an age-appropriate cerebral autoregulation. At the younger age, hyperoxic-induced CBF decrease may protect the brain from hyperoxemia.

[A 46-year-old patient with atrial fibrillation, elevated thyroid hormones and normal thyrotropine]. / Vorhofflimmern, erhöhte Schilddrüsenhormone und nicht supprimiertes TSH bei einem 46-jährigen Patienten.

We report on a 46 year old patient with a history of paroxysmal atrial fibrillation who presented to our emergency room. Diagnostic evaluation showed elevated free peripheral thyroid hormone levels and thyrotropine (TSH) hormone within normal limits. Ultrasound of the thyroid was normal, and thyroid autoantibodies were found in the normal range. There was a positive family history for thyroid dysfunction. TSH-producing adenoma (TSHoma) of the pituitary gland - the main differential diagnosis - was excluded by cranial MRI and laboratory tests. Familial thyroid hormone resistance (Refetoff syndrome) was suspected and could be confirmed by detection of a pathogenic mutation within the beta-thyroidhormone receptor gene. After spontaneous conversion to sinusrhythm the patient was treated with a beta(1)-selective betareceptor blocker. Up to now, no specific treatment is available to correct the defective beta-thyroidhormone receptor.

Turning carbon nanotubes from exceptional heat conductors into insulators.

Thermal conductivity (kappa) of isolated carbon nanotubes (CNTs) is higher than the kappa of diamond; however, in this Letter we show that the kappa of a packed bed of three-dimensional random networks of single and multiwall CNTs is smaller than that of thermally insulating amorphous polymers. The thermoelectric power (Sigma) of the random network of CNTs was also measured. The Sigma of a single wall nanotube network is very similar to that of isolated nanotubes and, in contrast with kappa, Sigma shows a strong dependence on the tube diameter.

A sex-linked SCAR marker in Bryonia dioica (Cucurbitaceae), a dioecious species with XY sex-determination and homomorphic sex chromosomes.

Genetic crosses between the dioecious Bryonia dioica (Cucurbitaceae) and the monoecious B. alba in 1903 provided the first clear evidence for Mendelian inheritance of dioecy and made B. dioica the first organism for which XY sex-determination was experimentally proven. Applying molecular tools to this system, we developed a sex-linked sequence-characterized amplified region (SCAR) marker for B. dioica and sequenced it for individuals representing the full geographic range of the species from Scotland to North Africa. For comparison, we also sequenced this marker for representatives of the dioecious B. cretica, B. multiflora and B. syriaca, and monoecious B. alba. In no case did any individual, male or female, yield more than two haplotypes. In northern Europe, we found strong linkage between our marker and sex, with all Y-sequences being identical to each other. In southern Europe, however, the linkage between our marker and sex was weak, with recombination detected within both the X- and the Y-homologues. Population genetic analyses suggest that the SCAR marker experienced different evolutionary pressures in northern and southern Europe. These findings fit with phylogenetic evidence that the XY system in Bryonia is labile and suggest that the genus may be a good system in which to study the early steps of sex chromosome evolution.

Thermodiffusion in model nanofluids by molecular dynamics simulations.

In this work, a new algorithm is proposed to compute single particle (infinite dilution) thermodiffusion using nonequilibrium molecular dynamics simulations through the estimation of the thermophoretic force that applies on a solute particle. This scheme is shown to provide consistent results for model nanofluids in the liquid state (spherical nonmetallic nanoparticles+Lennard-Jones fluid) where it appears that thermodiffusion amplitude, as well as thermal conductivity, decreases with nanoparticle concentration. Then, by changing the nature of the nanoparticle (size, mass, and internal stiffness) and that of the solvent (quality and viscosity), various trends are exhibited. In all cases, the single particle thermodiffusion is positive, i.e., the nanoparticle tends to migrate toward the cold area. The single particle thermal diffusion coefficient is shown to be independent of the size of the nanoparticle (diameter of 0.8-4 nm), whereas it increases with the quality of the solvent and is inversely proportional to the viscosity of the fluid. In addition, this coefficient is shown to be independent of the mass of the nanoparticle and to increase with the stiffness of the nanoparticle internal bonds. Besides, for these configurations, the mass diffusion coefficient behavior appears to be consistent with a Stokes-Einstein-like law.

[The human bocavirus: pathogen in airway infections?]. / Das humane Bocavirus: Erreger von Atemwegsinfektionen?

The human Bocavirus (HBoV), the second member of the parvovirus family, which displays pathogenicity in humans, has been described in 2005 by Allander et al.. It seems to be distributed worldwide and has been isolated mainly in infants and children with respiratory tract infection. This review covers all studies published on HBoV to February 2007 and discusses this emerging viral pathogen from the perspective of inpatient medical treatment centers.

[Low molecular heparin for treatment of venous thrombosis in two very low-birth-weight pre-term infants with genetic risk factors]. / Niedermolekulares Heparin bei Frühgeborenen mit hereditären Risikofaktoren und venösen Thrombosen.

We describe the use of low molecular weight heparin to treat venous thrombosis in two very low-birth-weight pre-term infants (GA: 30 and 27 weeks) both with genetic and acquired prothrombotic risk factors. Initially both infants were treated with unfractionated heparin. Since in one infant no effect on the thrombus size was observed and in the other infant there was an increase in size, the anticoagulation therapy was switched to subcutaneously injected low molecular heparin (Enoxaparin). During enoxaparin therapy the anti-Xa-level was carefully monitored and dosages were adjusted accordingly. Partial resolution of the thrombosis was achieved in both infants during enoxaparin therapy. No clot extension or recurrence of thrombosis occurred. An accidental overdose of Enoxaparin (100 times the required dosage) was administered to one infant without any consequences. Our data suggest that the use of low molecular weight heparin (Enoxaparin) for treatment of venous thrombosis in our two preterm infants was practical, safe and effective.

Interventional magnetic resonance imaging: an alternative to image guidance with ionising radiation.

At present, interventional procedures, such as stent placement, are performed under X-ray image guidance. Unfortunately with X-ray imaging, both patient and interventionalist are exposed to ionising radiation. Furthermore, X-ray imaging is lacking soft tissue contrast and is not capable of true 3-D displays of either interventional device or tissue morphology. Magnetic resonance imaging (MRI) offers excellent soft tissue contrast, 3-D acquisition techniques, as well as rapid image acquisition and reconstruction. Despite these advantages, MR-guided interventions are challenging owing to the limited access to the patient, strong magnetic and radio-frequency fields that require special interventional devices, inferior image frame rates and spatial resolution, and high MRI scanner noise. For MR-guided intravascular interventions, where access to the target organ is achieved through catheters, dedicated hardware and automated image slice positioning techniques have been developed. We illustrate that MR-guided renal embolisations can be performed in closed-bore high-field MR scanners.

Microscopic nature of the pygmy dipole resonance: the stable Ca isotopes.

The electric dipole strength distribution in 44Ca has been measured up to 10 MeV in high resolution photon scattering experiments for the first time. The data obtained have been compared to earlier measurements on (40,48)Ca in order to view the evolution of the electric pygmy dipole resonance (PDR). Calculations that were performed within the framework of the microscopic extended theory of finite Fermi systems, which adds contributions of the quasiparticle-phonon coupling to random phase approximation calculations, give a qualitative agreement with the experimental data for all three isotopes. We have shown that it is necessary to include this coupling to describe the PDR.