The Transpolar Drift conveys methane from the Siberian Shelf to the central Arctic Ocean.

Methane sources and sinks in the Arctic are poorly quantified. In particular, methane emissions from the Arctic Ocean and the potential sink capacity are still under debate. In this context sea ice impact on and the intense cycling of methane between sea ice and Polar surface water (PSW) becomes pivotal. We report on methane super- and under-saturation in PSW in the Eurasian Basin (EB), strongly linked to sea ice-ocean interactions. In the southern EB under-saturation in PSW is caused by both inflow of warm Atlantic water and short-time contact with sea ice. By comparison in the northern EB long-time sea ice-PSW contact triggered by freezing and melting events induces a methane excess. We reveal the Ttranspolar Drift Stream as crucial for methane transport and show that inter-annual shifts in sea ice drift patterns generate inter-annually patchy methane excess in PSW. Using backward trajectories combined with δ18O signatures of sea ice cores we determine the sea ice source regions to be in the Laptev Sea Polynyas and the off shelf regime in 2011 and 2015, respectively. We denote the Transpolar Drift regime as decisive for the fate of methane released on the Siberian shelves.

Variable versus conventional lung protective mechanical ventilation during open abdominal surgery (PROVAR): a randomised controlled trial.

BACKGROUND: Experimental studies showed that controlled variable ventilation (CVV) yielded better pulmonary function compared to non-variable ventilation (CNV) in injured lungs. We hypothesized that CVV improves intraoperative and postoperative respiratory function in patients undergoing open abdominal surgery. METHODS: Fifty patients planned for open abdominal surgery lasting >3 h were randomly assigned to receive either CVV or CNV. Mean tidal volumes and PEEP were set at 8 ml kg-1 (predicted body weight) and 5 cm H2O, respectively. In CVV, tidal volumes varied randomly, following a normal distribution, on a breath-by-breath basis. The primary endpoint was the forced vital capacity (FVC) on postoperative Day 1. Secondary endpoints were oxygenation, non-aerated lung volume, distribution of ventilation, and pulmonary and extrapulmonary complications until postoperative Day 5. RESULTS: FVC did not differ significantly between CVV and CNV on postoperative Day 1, 61.5 (standard deviation 22.1) % vs 61.9 (23.6) %, respectively; mean [95% confidence interval (CI)] difference, -0.4 (-13.2-14.0), P=0.95. Intraoperatively, CVV did not result in improved respiratory function, haemodynamics, or redistribution of ventilation compared to CNV. Postoperatively, FVC, forced expiratory volume at the first second (FEV1), and FEV1/FVC deteriorated, while atelectasis volume and plasma levels of interleukin-6 and interleukin-8 increased, but values did not differ between groups. The incidence of postoperative pulmonary and extrapulmonary complications was comparable in CVV and CNV. CONCLUSIONS: In patients undergoing open abdominal surgery, CVV did not improve intraoperative and postoperative respiratory function compared with CNV. CLINICAL TRIAL REGISTRATION: NCT 01683578.

Attitudes toward postmortem cornea donation in Germany: a multicenter survey.

PURPOSE: To analyse the willingness for postmortem cornea donation in Germany. METHODS: Employees in two cities (UKM, UKS), and university hospitals (STM, STE), members of the German Ophthalmological Society (DOG), and employees of an automobile company (BO) participated in a questionnaire about postmortem cornea donation attitudes. The questionnaire consisted of demographic items, motives concerning postmortem cornea donation, general attitudes toward donation, and questions concerning the perceived needs for information about donation. The statistical analyses included logistic regression with the target parameter of 'willingness to donate cornea postmortem'. RESULTS: Of the participants, 67.7 % (UKM, UKS), 70.9 % (STM, STE), 70.8 % (BO), and 79.4 % (DOG) declared their intention to donate their corneas postmortem. Younger age (p < 0.001), poorer general health (p < 0.05), faith in an eternal life (p < 0.05), disagreement with brain death diagnostics (p < 0.001), fear of receiving worse medical treatment (p < 0.001), and fear of the commercialization of organs (p < 0.001) were found to be risk factors for a negative attitude toward postmortem cornea. The majority of participants (57.4 %) indicated that additional information about donation would be appreciated, and the internet (69.9 %) was considered the most appropriate means for conveying this information. CONCLUSIONS: Emotional items were revealed to be the most relevant factors influencing the willingness to donate cornea postmortem, which may be counteracted by means of public education. The relatively low willingness among the medical staff contrasts with previous observations in a professional ophthalmologic society.

[Results of an internet-based survey amongst members of the German Ophthalmological Society concerning postmortem cornea donation]. / Ergebnisse einer internetbasierten Umfrage zur Hornhautspendebereitschaft bei DOG-Mitgliedern.

BACKGROUND: Analysis of willingness for postmortem cornea donation by professionals in ophthalmology and their motives in favor of or against donation. PATIENTS AND METHODS: 3887 members of the German Ophthalmological Society received an anonymous questionnaire concerning sociodemographic background, physical health, experiences with organ explantation and their former engagement and motives concerning organ and cornea donation. RESULTS: 722 of the questionnaires were partially and 533 completely answered with an average willingness for cornea donation of 79.4%. Significant parameters for cornea donation were gender, former experience with organ explantation, ophthalmological health and fear of false diagnosis of brain death, worse medical treatment or organ commercialization. Of the participants 53.9% suggested the internet as a favorite source of information in this matter. CONCLUSION: The factors which had a significant impact on cornea donation in this survey seem to be mainly a result of insufficient information. Detailed information regarding this topic should preferentially be presented on internet pages of professional societies and could probably increase donation approval of DOG members.

[New strategies for the treatment of thermally injured hands with regard to the epithelial substitute Suprathel]. / Neue Strategien zur Behandlung thermisch geschädigter Hände unter Berücksichtigung des Epithelersatzes Suprathel.

The treatment of thermally injured hands has changed in the last 20 years. An early necrectomy and grafting with split-skin grafts is recommended by most burn specialists. The outcome in regard to cosmetic and functional results could be improved by early grafting. Meanwhile unnecessary grafts in burns with indeterminate depth can be avoided by new skin replacements. The new epithelial substitute Suprathel is marked by a considerable reduction of pain if it is applied on second degree burns. Therefore the mobilisation of the burned patient can be accelerated. Many hand burns were treated by Suprathel in our burn centre without severe scarring and without loss of function. We treated 76 inpatients with thermally injured hands in our burn centre from January 2004 to July 2006. Only 28 (25.7 %) of all 109 afflicted hands required a primary skin grafting. Suprathel was applied primarily in 78 hands (71.6 %). 3 hands were treated otherwise. 8 of the hands which were primarily treated by Suprathel (10.3 %) required a well-aimed grafting after one or two weeks, 70 (89.7 %) had a complete epithelisation without grafting. Many skin grafts could be avoided. We modified our strategy for the treatment of burned hands by our excellent experiences with Suprathel.

Remediation of heavy metal-contaminated forest soil using recycled organic matter and native woody plants.

The main aim of this study was to determine how the application of a mulch cover (a mixture of household biocompost and woodchips) onto heavy metal-polluted forest soil affects (i) long-term survival and growth of planted dwarf shrubs and tree seedlings and (ii) natural revegetation. Native woody plants (Pinus sylvestris, Betula pubescens, Empetrum nigrum, and Arctostaphylos uva-ursi) were planted in mulch pockets on mulch-covered and uncovered plots in summer 1996 in a highly polluted Scots pine stand in southwest Finland. Spreading a mulch layer on the soil surface was essential for the recolonization of natural vegetation and increased dwarf shrub survival, partly through protection against drought. Despite initial mortality, transplant establishment was relatively successful during the following 10 yr. Tree species had higher survival rates, but the dwarf shrubs covered a larger area of the soil surface during the experiment. Especially E. nigrum and P. sylvestris proved to be suitable for revegetating heavy metal-polluted and degraded forests. Natural recolonization of pioneer species (e.g., Epilobium angustifolium, Taraxacum coll., and grasses) and tree seedlings (P. sylvestris, Betula sp., and Salix sp.) was strongly enhanced on the mulched plots, whereas there was no natural vegetation on the untreated plots. These results indicate that a heavy metal-polluted site can be ecologically remediated without having to remove the soil. Household compost and woodchips are low-cost mulching materials that are suitable for restoring heavy metal-polluted soil.

Suprathel, a new skin substitute, in the management of donor sites of split-thickness skin grafts: results of a clinical study.

OBJECTIVE: A prospective, randomized, two center clinical study was conducted to evaluate the impact on wound healing of Suprathel in donor sites of split-thickness skin grafts. Suprathel represents an absorbable, synthetic wound dressing with properties of natural epithelium. METHODS: 22 burn patients who were treated with split-thickness skin grafts, and with a mean age of 39.6 years were included in the study. Donor sites of skin grafts were randomly selected; partly treated with Jelonet and partly treated with Suprathel. First gauze change was carried out the fifth day postoperatively followed by regular wound inspection until complete re-epithelization. The study focused on patient pain score, healing time, analysis of wound bed, ease of care, and treatment costs. RESULTS: There was no significant difference between the two materials tested regarding healing time and re-epithelization. There was a significantly lower pain score for patients treated with Suprathel (p=0.0002). Suprathel became transparent when applied and allowed close monitoring of wound healing. In contrast to Jelonet, Suprathel showed excellent plasticity with better attachment and adherence to wound surfaces. Throughout the healing process it detached from wounds without damaging the new epithelial surface. In addition, wound areas treated with Suprathel required less frequent dressing changes. It also demonstrated excellent ease of care. This, altogether with the significant pain reduction, presented a positive feedback by patients and healthcare professionals who both rated Suprathel as their treatment preference. Though Jelonet is more cost effective as dressing material, the study revealed an overall reduction in total treatment costs achieved with Suprathel. CONCLUSION: Suprathel represents a solid, reliable epidermal skin substitute with impact on wound healing, patient comfort and ease of care. The material effectiveness contributes to the reduction of overall treatment costs.

[Loss of function and morphological changes in subfoveolar choroidal neovascularisations and various beginnings of photodynamic therapies]. / Funktionsverlust und morphologische Veränderungen bei subfoveolaren choroidalen Neovaskularisationen und differentem Beginn photodynamischer Therapien.

BACKGROUND: In the year 2000, the photodynamic therapy (PDT) was introduced as a new option for the treatment of exudative choroidal neovascularisation (CNV). Since this kind of therapy required the health insurance company's consent, the waiting period for the first therapy varied considerably. MATERIALS AND METHODS: Between July 2000 and September 2004, 133 eyes were treated via PDT. In this study, 59 courses were analysed retrospectively, all of them within the frame of a classic or predominantly classic exudative CNV. RESULTS: At the time of indication for the therapy, 38.46 % of the eyes of patients under the age of 65 and 73.91 % of the eyes of patients over the age of 65 showed a visual acuity (VA) of less than 0.3. Nine eyes lost the VA needed to drive a car (> or = 0.6), eight eyes lost the reading ability (< 0.4) before the first PDT. One eye lost its reading ability, one eye reached the classification of "visually handicapped & blindness" (< or = 0.3) and one eye went blind (< or = 0.02) within 7 days of waiting time. CONCLUSION: Elderly people showed less VA at first investigations by ophthalmologists, which underscores the necessity of an intensive campaign about the classic symptoms of AMD. The results of this study confirm that loss of VA can be caused by CNV progression within seven days. Whether or not rapid treatment with PDT influences the visual and morphological outcome, has to be proven by more extensive studies.

Suprathel-an innovative, resorbable skin substitute for the treatment of burn victims.

Autologous split skin grafts are the most reliable method for closing third degree burns. Under this scheme, donor sites as well as second degree burns under conservative treatment, however, would benefit from rapid wound closure. For this treatment, biological as well as synthetic materials are available. For the improvement of these materials, primary goals are pain reduction and easy handling in the absence of biological risk. From a synthetic copolymer mainly based on DL-lactic acid a new skin substitute was developed, marketed as Suprathel. Within the scope of a bicentric study Suprathel was compared versus paraffin gauze intraindividually applied on split skin donor sites. Wound pain was measured on the Visual Pain Analog Scale over a period of 10 days as the critical criterion. Accordingly Suprathel versus Omiderm were compared on second degree burns (degree 2a, partial thickness burns). In both study parts, Suprathel significantly reduced pain. Its easy handling was superior compared to other materials. The Suprathel membrane adhered rapidly to the wound thus protecting against infections and promoting wound healing. No allergic reactions were observed. The ability of the material to resorb ensured pain-free removal after complete healing of the wound.

Consensus meeting on "Relevance of parenteral vitamin C in acute endothelial dependent pathophysiological conditions (EDPC)".

The 22 supersetnd Hohenheim Consensus Workshop took place in at the University of Stuttgart-Hohenheim. The subject of this conference was vitamin C and its role in the treatment of endothelial dysfunction. Scientists, who had published and reviewed scientific and regulatory papers on that topic were invited, among them basic researchers, toxicologists, clinicians and nutritionists. The participants were presented with eleven questions, which were discussed and answered at the workshop, with the aim of summarising the current state of knowledge. The explicatory text accompanying the short answers was produced and agreed on after the conference and was backed up by corresponding references. The therapeutic relevance of administration of the physiological antioxidant vitamin C in high parenteral doses in Endothelial Dependent Pathophysiological Conditions (EDPC) was discussed. Endothelial dysfunction is defined as including disturbed endothelial dependant relaxation of resistance vessels, breakdown of the microvascular endothelial barrier and/or loss of anti-adhesive function. It occurs in severe burn injury, intoxications, acute hyperglycemia, sepsis, trauma, and ischemic-reperfusion tissue injury and is induced by oxidative stress. Reduced plasma ascorbate levels are a hallmark of oxidative stress and occur in severe burns, sepsis, severe trauma, intoxication, chemotherapy/radiotherapy and organ transplantation. Vitamin C directly enhances the activity of nitric oxide synthase, the acyl CoA oxidase system and inhibits the actions of proinflammatory lipids. There is experimental evidence that parenteral high-dose vitamin C restores endothelial function in sepsis. In vitro, supraphysiological concentrations (> 1mM) of ascorbate restore nitric oxide bioavailability and endothelial function. Only parenterally, can enough vitamin C be administered to combat oxidative stress. There is no evidence that parenteral vitamin C exerts prooxidant effects in humans. Theoretical concerns in relation to competitive interactions between vitamin C and glucose cellular uptake are probably only relevant for oxidised vitamin C (dehydroascorbate).

Illuminated artificial orbit for the training of vitreoretinal surgery in vitro.

PURPOSE: Demonstrations and practical experiments are important constituents of the teaching of surgical principles and techniques to residents in ophthalmology. The objective was to develop an eye-support device for experimental and didactic use during vitreoretinal microsurgery in vitro. METHODS: Various eye-support devices with different light sources and illumination intensities were designed and tested. The main components of the final prototype are a high-intensity halogen lamp, a flexible light guide, a cylinder with a mirror inside, and a replaceable, transparent eye support with a ring-adapter. Light from the point source is reflected via the light guide into the cylinder and through the eye support transsclerally into the eye. RESULTS: The device illuminates the retina and the vitreous body sufficiently. It accentuates the transparent appearance of the retina and makes the three-dimensional structure more visible, for example, in case of retinal detachment. Subretinal tissue can be visualized and differentiated more precisely. CONCLUSIONS: The device is useful, in the teaching of residents and in experimental vitreoretinal surgery.