Recovering ultraclean lignins of controlled molecular weight from Kraft black-liquor lignins.

By operating in a region of liquid-liquid equilibrium, hot acetic acid-water mixtures can be used to simultaneously clean, fractionate, and solvate Kraft black-liquor lignins. Lignin-rich liquid phases of controlled molecular weight with key metals contents reduced to <50 ppm are obtained without a washing step.

[Reconstructions after periorbital burn injuries]. / Rekonstruktionen nach periorbitalen Brandverletzungen.

Nowadays burn patients who also have periocular symptoms are usually treated by reconstructive surgeons and the role of the ophthalmic surgeon has decreased.Although periocular complications occur in a minority of burned patients, they pose a greater challenge in surgical and non-surgical treatment. Chemical, electrical and thermal burns can lead to disfiguring scar formations and delayed treatment can lead to devastating ocular complications. Achieving a successful reconstruction requires a comprehensive approach, entailing many advanced techniques with an emphasis on preserving function and balancing intricate aesthetic requirements. The theory is illustrated in this article with clinical examples.

[Development of oculoplastic surgery in Kinshasa (capital of Democratic Republic of Congo)]. / Entwicklung der okuloplastischen Chirurgie in Kinshasa (Hauptstadt der Demokratischen Republik Kongo).

The partnership between Saint Joseph Hospital in Kinshasa (Capital city of DRC) and University Eye Clinic Rostock, Germany exists since 2000. The ophthalmologists from Rostock University performed 12 visits of St. Josef Hospital with the aim to perform oculoplastic surgery in complicated cases as well as to teach the local ophthalmologists. There they performed about 150 surgeries (entropion, ectropion, ptosis, repair of lid injuries, eye lid reconstruction and tumour management, lacrimal surgery) in joint teams. The programme of on-site training was established during this time. Meanwhile, the Kinshasa colleagues are able to perform the basic techniques by themselves. Two colleagues have obtained advanced training in oculoplastics in Rostock. The fruitful cooperation enabled the development of oculoplastic surgery in St. Josef Hospital in Kinshasa. The further education and training proccesses will support the continuous advancement in ophthalmological health care in DRC.

International standardisation work on the measurement of radon in air and water.

Radon is considered to be the main source of human exposure to natural radiation. As stated by the World Health Organization, the exposure due to the inhalation of indoor radon is much greater than the one via the ingestion of water as radon degasses from water during handling. In response to these concerns about the universal presence of radon, environmental assessment studies are regularly commissioned to assess the radon exposure of public and workers. The credibility of such studies relies on the quality and reliability of radon analysis as well as on the sample representativeness of the radiological situation. The standard-setting approach, based on consensus, seemed to lend itself to a settlement of technical aspects of potential comparison. At present, two Working Groups of the International Standardization Organization are focussing on drafting standards on radon and its decay products measurement in air and water. These standards, which aim for a set of rigorous metrology practices, will be useful for persons in charge of the initial characterisation of a site with respect to natural radioactivity as well as to those performing the routine surveillance of specific sites.

[How can artificial eye motility be improved? The influence of fornix configuration and tissue thickness in front of hydroxyapatite-silicon implants in 66 patients]. / Wie lässt sich die Prothesenmotilität verbessern? Der Einfluss von Fornixtiefe und Gewebedicke vor einem Hydroxylapatitsilikon-Implantat bei 66 Patienten.

Porous hydroxyapatite of various origins has proven to be a suitable material for orbital volume replacement. Its biocompatibility surpasses all other options. The transmitted motility to the artificial eye has nevertheless, not always been to the full satisfaction of patients, oculists and ophthalmologists. Our study has shown a strong correlation between the depth of the superior and interior fornices as well as the thickness of tissue material covering the implant anterior surface.

[Muscle pedunculated scleral flaps. A microsurgical modification to improve prosthesis motility]. / Deckung von Orbitaimplantaten mit muskelgestielter autologer Sklera Eine mikrochirurgische Modifikation zur Verbesserung der Prothesenmotilität.

Orbital implants following enucleation are able beyond all doubt to compensate volume adequately and improve artificial eye motility. In recent decades progress has been made concerning implant material. Nevertheless, in most designs wrapping with homoplastic or alloplastic materials is advocated. In this report a microsurgical concept is presented to avoid wrapping material and at the same time to improve prosthesis motility in a hydroxyapatite-silicon implant. In a retrospective study two groups of patients (15 individuals each) were compared concerning prosthesis motility 6 months after surgery. In group 1 the horizontal and vertical eye muscles were sutured cross-wise in front of the implant (as done since the introduction of this type in 1989). In group 2 autologous muscle pedunculated scleral flaps were dissected microsurgically and used to cover the anterior part of the porous hydroxyapatite component of the implant. There was a highly significant better prosthesis motility and so far no complications concerning implant coverage in this second group. The authors consider the use of muscle pedunculated sclera to be a modification to improve the cosmetic outcome which may also reduce the postoperative complication rate in enucleation surgery.

Expression of the Ca2+ mobilizing muscarinic system in the chick embryo correlates with morphogenesis.

We describe muscarinic receptors and intracellular Ca2+ mobilization after cholinergic stimulation in cell suspensions prepared from chick embryos between day 2 (stage 12/13) and day 13 (stage 40) of development. Cell suspensions are prepared from whole chick embryos and from embryonic hearts, heads or brains, limb buds, and trunks. Muscarinic receptors are measured using [3H]quinuclidinylbenzilate as specific ligand. Intracellular Ca2+ mobilization is determined by changes of chlorotetracycline fluorescence. (1) Considerable amounts of muscarinic receptors are found in all parts of the embryo and at all stages tested. (2) The intracellular Ca2+ response after stimulation by muscarinic agonist shows a peak at day 3-4 (stage 23). (3) The pharmacological profile of the Ca2+ response remains constant during embryonic development and differs from the profiles of most adult systems. (4) The 'embryonic muscarinic system' is uniformly expressed in cells from neural and non-neural tissues. It appears and disappears independently of innervation.