Intercomparison of bidirectional reflectance distribution function measurements at in- and out-of-plane geometries.

In recent years, there has been a growing interest in the measurements of the bidirectional reflectance distribution function (BRDF) in industry and research and development. However, there is currently no dedicated key comparison to demonstrate the scale conformity. To date, scale conformity has been proved only for classical in-plane geometries, in comparisons between different national metrology institutes (NMIs) and designated institutes (DIs). This study aims at expanding that with nonclassical geometries, including, for the first time, to the best of our knowledge, two out-of-plane geometries. A total of four NMIs and two DIs participated in a scale comparison of the BRDF measurements of three achromatic samples at 550 nm in five measurement geometries. The realization of the scale of BRDF is a well-understood procedure, as explained in this paper, but the comparison of the measured values presents slight inconsistencies in some geometries, most likely due to the underestimation of measurement uncertainties. This underestimation was revealed and indirectly quantified using the Mandel-Paule method, which provides the interlaboratory uncertainty. The results from the presented comparison allow the present state of the BRDF scale realization to be evaluated, not only for classical in-plane geometries, but also for out-of-plane geometries.

Treatment of cardiac arrest in the hyperbaric environment: key steps on the sequence of care--case reports.

The U.S. territory of Guam attracts thousands of military and civilian divers annually and is home to the only recompression facility within a 5,000-km radius that accepts critically injured dive casualties. As recompression chambers are confined spaces and standard use of electrical cardioversion cannot be used, cardiac resuscitation at depth must deviate from advanced cardiovascular life support (ACLS) algorithms. Furthermore, many hyperbaric chambers that accept dive casualties are in remote locations, a situation that requires providers to approach cardiac resuscitation in a different way when compared to an in-hospital or ICU setting. This presents a challenge to trained medical and diving professionals. We present two contrasting vignettes of diving injuries initially responsive to appropriate treatment but then deteriorating during recompression therapy and ultimately requiring resuscitation at depth. Additionally, we explore the physiologic basis of resuscitation in a hyperbaric environment as it relates to the treatment of cardiac arrest at depth. This review critically examines the current guidelines in place for emergency cardiac resuscitation in a hyperbaric chamber followed by recommendations for the key steps in the sequence of care.

[Social media: forum webcare as a proactive information strategy in health promotion: Results of a pilot project by the BZgA]. / Social Media - Foren-Webcare als proaktive Informationsstrategie in der Gesundheitsförderung : Ergebnisse aus einem Pilotprojekt der Bundeszentrale für gesundheitliche Aufklärung (BZgA).

Over several weeks in 2013, the BZgA pilot project "SoMe" (August 2012 to February 2014) tested and investigated various social media interventions in the fields of family planning and sex education. The interventions included the tool "forum webcare," which was used in four forums for pregnant women and three for young people. The term webcare originally described a customer-oriented communication strategy of the web economy. The term includes elements of reputation management, customer care, and online marketing. In the present pilot project, forum webcare has been understood and applied in the sense of "virtual street work," which means that issues on health topics in non-self-operated forums were identified and answered. The design was based on the Precede-Proceed Model. In the phases of analysis, implementation, and evaluation the project used chronologically and methodologically interlaced and mutually controlling methods such as online test groups, intensive interviews, and the evaluation of data on web use. The analysis indicated that the target groups of the project used the forums quite often; that they had a positive attitude toward the idea of webcare providing contributions from experts working for public institutions; and that the risk of reactance was low. Forum webcare allows important supplementary and well-founded information to be brought into the discussions. At the same time the results of the project show that users, when keeping to certain rules, mostly see webcare as a welcome addition to incomplete information and the improvement of faulty information, and appreciate it as quality enhancement for the forum. From the view of the information provider, forum webcare is more a chance to address numerous passive recipients rather than communicating with single users. At the same time the instrument provides the chance to learn from users of the forums, and to become familiar with and be able to respond to their needs and the way in which they receive information. For the purposes of systemic health literacy, webcare can thus also contribute to the expansion of institutional health competence.

Development of primary reference facilities and measurement comparison of standard artifacts for the bidirectional transmittance distribution function.

To determine the bidirectional transmittance distribution function (BTDF) of diffusely transmitting materials, two new primary facilities have been developed at the Physikalisch-Technische Bundesanstalt (PTB) and Aalto University (Aalto). A detailed description of both facilities and the different approaches used are presented in this paper. The performance of both facilities is compared by determining the BTDF of two different diffuser types in both in-plane and out-of-plane bidirectional geometries at four different wavelengths in the visible spectral range. Due to delayed completion of PTB's primary facility, the measured BTDF values are compared between Aalto's primary facility and another PTB setup, whose measurement scales are successfully transferred to PTB's primary facility by an internal comparison. A thorough analysis of the measurement uncertainty is presented, leading to a combined k = 1 standard uncertainty of 0.8%-1.2% for PTB's primary facility and 1.3%-1.7% for Aalto's primary facility. The BTDF results obtained agree well within their expanded k = 2 uncertainty. This indirect bilateral comparison shows that Aalto's and PTB's new facilities are suited as primary reference setups for the determination of the BTDF. These studies also reveal action points to improved measurement capabilities and for a reduction of the measurement uncertainty, depending on the type of diffuser under test.

Autologous stem cell therapy in the treatment of limb ischaemia induced chronic tissue ulcers of diabetic foot patients.

BACKGROUND AND AIM: Despite improvements in surgical revascularisation, limitations like anatomical factors or atherosclerosis limit the success of revascularisation in diabetic patients with critical limb ischaemia. Stem cells were shown to improve microcirculation in published studies. The aim of this study was to evaluate safety, feasibility and efficacy of transplantation of bone marrow derived cellular products regarding improvement in microcirculation and lowering of amputation rate. METHODS: Bone marrow mononuclear cells (BMCs) in comparison with expanded bone marrow cells enriched in CD90+ cells ('tissue repair cells', TRCs) were used in the treatment of diabetic ulcers to induce revascularisation. Diabetic foot patients with critical limb ischaemia without option for surgical or interventional revascularisation were eligible. Parameters examined were ABI, TcPO(2) , reactive hyperaemia and angiographic imaging before and after therapy. RESULTS: Of 30 patients included in this trial, 24 were randomised to receive either BMCs or TRCs. The high number of drop-outs in the control group (4 of 6) led to exclusion from evaluation. A total of 22 patients entered treatment; one patient in the TRC group and two in the BMC group did not show wound healing during follow up, one patient in each treatment group died before reaching the end of the study; one after having achieved wound healing (BMC group), the other one without having achieved wound healing (TRC group). Thus, 18 patients showed wound healing after 45 weeks. The total number of applicated cells was 3.8 times lower in the TRC group, but TRC patients received significantly higher amounts of CD90+ cells. Improvement in microvascularisation was detected in some, but not all patients by angiography, TcPO(2) improved significantly compared with baseline in both therapy groups. CONCLUSION: The transplantation of BMCs as well as TRCs proved to be safe and feasible. Improvements of microcirculation and complete wound healing were observed in the transplant groups.

Pharmacokinetics of bromide in adult sheep following oral and intravenous administration.

OBJECTIVE: To determine the pharmacokinetics of bromide in sheep after single intravenous (IV) and oral (PO) doses. PROCEDURE: Sixteen Merino sheep were randomly assigned to two treatment groups and given 120 mg/kg bromide, as sodium bromide IV or potassium bromide PO. Serum bromide concentrations were determined by colorimetric spectrophotometry. RESULTS: After IV administration the maximum concentration (Cmax ) was 822.11 ± 93.61 mg/L, volume of distribution (Vd ) was 0.286 ± 0.031 L/kg and the clearance (Cl) was 0.836 ± 0.255 mL/h/kg. After PO administration the Cmax was 453.86 ± 43.37 mg/L and the time of maximum concentration (Tmax ) was 108 ± 125 h. The terminal half-life (t½ ) of bromide after IV and PO administration was 387.93 ± 115.35 h and 346.72 ± 94.05 h, respectively. The oral bioavailability (F) of bromide was 92%. No adverse reactions were noted in either treatment group during this study. The concentration versus time profiles exhibited secondary peaks, suggestive of gastrointestinal cyclic redistribution of the drug. CONCLUSIONS AND CLINICAL RELEVANCE: When administered PO, bromide in sheep has a long half-life (t½ ) of approximately 14 days, with good bioavailability. Potassium bromide is a readily available, affordable salt with a long history of medical use as an anxiolytic, sedative and antiseizure therapy in other species. There are a number of husbandry activities and flock level neurological conditions, including perennial ryegrass toxicosis, in which bromide may have therapeutic or prophylactic application.

Femtosecond modification of electron localization and transfer of angular momentum in nickel.

The rapidly increasing information density required of modern magnetic data storage devices raises the question of the fundamental limits in bit size and writing speed. At present, the magnetization reversal of a bit can occur as quickly as 200 ps (ref. 1). A fundamental limit has been explored by using intense magnetic-field pulses of 2 ps duration leading to a non-deterministic magnetization reversal. For this process, dissipation of spin angular momentum to other degrees of freedom on an ultrafast timescale is crucial. An even faster regime down to 100 fs or below might be reached by non-thermal control of magnetization with femtosecond laser radiation. Here, we show that an efficient novel channel for angular momentum dissipation to the lattice can be opened by femtosecond laser excitation of a ferromagnet. For the first time, the quenching of spin angular momentum and its transfer to the lattice with a time constant of 120+/-70 fs is determined unambiguously with X-ray magnetic circular dichroism. We report the first femtosecond time-resolved X-ray absorption spectroscopy data over an entire absorption edge, which are consistent with an unexpected increase in valence-electron localization during the first 120+/-50 fs, possibly providing the driving force behind femtosecond spin-lattice relaxation.

Femtosecond undulator radiation from sliced electron bunches.

At the 1.7-GeV electron storage ring BESSY II, a first source of synchrotron radiation with 100 fs pulse duration, variable (linear and circular) polarization, tunable photon energy (300 to 1400 eV), and excellent signal-to-background ratio was constructed and is now in routine operation.

Femtosecond terahertz radiation from femtoslicing at BESSY.

Femtosecond far-infrared radiation pulses in the THz spectral range were observed as a consequence of the energy modulation of 1.7 GeV electrons by femtosecond laser pulses in the BESSY storage ring in order to generate femtosecond x-ray pulses ("femtoslicing"). In addition to being crucial for diagnostics of the laser-electron interaction, the THz radiation itself is useful for experiments where intense ultrashort THz pulses of well-defined temporal and spectral characteristics are required.

Two-color Brillouin ring laser gyro with gyro-compassing capability.

We investigated the gyro-compassing capability of a Brillouin ring laser gyro set up in a two-color operation. Two counterpropagating pump lasers initiated two Brillouin ring lasers on different resonances of a fiber-optic ring resonator cavity, which excluded the mutual intracavity interaction between both counterpropagating Brillouin lasers. Additionally minimizing the external feedback channels of the individual Brillouin lasers allowed for high-resolution measurements, e.g., the horizontal component of the Earth's rotation rate (10.0 degrees /h at Uberlingen, Germany, which corresponded to a beat frequency of 6.85 Hz).