A novel scraped cooled wall crystallizer (SCWC-2) with 130 l capacity and total heat transfer area of 2.94 m2 m−3 crystallizer volume was specifically designed for eutectic freeze crystallization (EFC). It has been successfully tested for the recovery of Na2CO3 from an industrial solution. Compared with earlier designs this new crystallizer shows a high improvement in gravitational separation and ice scaling removal. High heat transfer fluxes between the heat exchanger and the solution (up to 10.5 kW m−2) were obtained and as a consequence high production rates were achieved.

Eutectic freeze crystallization was tested in a scaled up version of a scraped cooled wall crystallizer on an industrial aqueous sodium carbonate–sodium bicarbonate waste stream containing traces of molybdenum. A heat transfer rate of 5kWm−2 was maintained in the crystallizer. Sodium carbonate decahydrate with molybdenum content below 1ppm and pure ice were produced by continuous crystallization at −3.8°C by operating within the metastable zone width of bicarbonate. At −4.0°C bicarbonate started to co-crystallize. The bimodal size distribution of the mixture resulted in poor filtration and purity of the salt product.

The object of the study was to investigate the effect of EMLA cream when used as an anaesthetic for the debridement of ulcers and wounds. The cream was applied to a fresh, standardized wound caused by a dermatome, to an ulcer which was to be revised and for simultaneous split-skin grafting to both donor site and recipient area to be debrided. The effect on wound healing, the plasma concentrations of lidocaine and prilocaine and the analgesic effect following the application of EMLA to the ulcer and to both ulcer and donor site were studied. The study showed that EMLA cream when topically applied has a sufficient analgesic effect for revision of an open ulcer and can be used concomitantly for both revision of the ulcer and cutting of the split-skin graft. The application of EMLA cream to the fresh wound, or to the recipient area prior to cleaning, did not cause any clinical signs of a delayed healing at the applied areas compared to the control sites.

Ropivacaine, a new long–acting amino–amide local anaesthetic agent, and bupivacaine, in various concentrations with or without addition of adrenaline, were tested in a randomized, double–blind study using intradermal wheals. Ten non–smoking, healthy, young male volunteers participated. Inseries Iplain solutions of ropivacaine (0.25%, 0.5%, 0.75% and 1%) and bupivacaine (0.25%, 0.5% and 0.75%) were injected intradermally and inseries IIthe same concentrations, with the addition of adrenaline 5 ug ml‐1(1:200 000), were used. The same volunteers took part in both series, with an interval of at least three weeks between the experiments. Saline was included as control in both series. Pin–pricking was used to assess the dermal analgesia. Plain solutions of ropivacaine produced significantly longer durations of dermal analgesia than did plain solutions of bupivacaine, in all tested concentrations. A significant increase in duration was seen for both local anaesthetics when adding adrenaline. Local vascular effects at the injected areas were determined by visual inspection (nil, pink, pale). Local blanching (pale) was significantly more frequent for plain solutions of ropivacaine, in all tested concentrations. Local redness (pink) was significantly more frequent with plain bupivacaine, in a dose–dependent relation. An initial redness was frequently observed for both local anaesthetics containing adrenaline, followed by blanching at most sites.

The influence of intradermal needle insertion and fluid injection on skin blood flow was investigated using laser Doppler flowmetry. Seventeen healthy, young male volunteers participated. Four test sites on each forearm (volar surface) were used in a randomized, double‐blind study. Recordings were made at 20, 40, 60 and in GroupIIIalso at 90 min after needle insertion or intradermal injection. In GroupI(n = 6) different volumes of saline (0.05, 0.1, 0.2, 0.3 and 0.5 ml) were injected, producing an increase in flow, there being no differences between the various volumes. In GroupII(n = 4) needle insertions were made using different needle sizes (20 G, 23 G and 30 G), the larger ones being impractical to use. Increases in flow were seen, and were somewhat higher for the larger needles. GroupIII(n= 12) was studied regarding the effects of three local anaesthetic agents on skin blood flow (0.1 ml, 30 G needle). Injection of bupivacaine 0.75d̀ produced a marked increase in flow, similar to lidocaine 1% but apparently longer lasting. Bupivacaine 0.25% caused less increase in flow, similar to the flow seen with saline. Injections of ropivacaine 0.75d̀ and 0.25%, i.e. in clinical concentrations, caused a decrease in blood flow, this being most marked after 0.25d̀, indicating a unique flow‐decreasing effect of this new local anaesthetic drug.

In a series of experiments in rabbits the dermal reaction, provoked by a single dose or intermittent doses of irradiation, was prevented or modified by topical or parenteral administration of local anaesthetics, compared to irradiated control animals. The topical application of a eutectic lidocaine/prilocaine cream, EMLA 5%, was found to be more effective than intravenously injected lidocaine (Xylocain 1%).

The effect of bupivacaine 7.5 mg/ml with epinephrine 5μg/ml, etidocaine 15 mg/ml with epinephrine 5 μg/ml, and lidocaine 20 mg/ml with epinephrine 12.5 μg/ml was studied when used for oral infiltration anesthesia. Twenty healthy volunteers took part in the experimental and double-blind study. One ml of the respective anesthetic solution was deposited supraperiosteally in the apical area of the maxillary right lateral incisor. Onset time, frequency of analgesia, gingival spread, and duration of tooth analgesia were studied and duration of soft-tissue numbness registered. The present investigation showed that lidocaine had a shorter onset time compared with bupivacaine. No difference with regard to frequency was found. Bupivacaine and etidocaine had a longer period of soft-tissue numbness, but a significantly shorter duration of tooth analgesia than lidocaine.

The effects of the cutaneous application of EMLA cream (a eutectic mixture of lignocaine and prilocaine in their base form) were studied in volunteers. When tested by pin-prick, EMLA cream 2.5% and 5% produced analgesia of the area tested, the cream being most effective if left in contact with the skin for 60 min. The pain produced by the insertion of an i.v. cannula was successfully blocked by the application of this formulation, especially if applied to the antecubital area. Temporary blanching of the skin areas was frequently observed on removal of the occlusive tape bandages, but prolonged, or repeated, application of 5% EMLA cream did not produce local skin reactions. Tests for delayed hypersensitivity reactions were negative. Plasma concentrations of lignocaine and prilocaine were low after a standard application.

In an experimental study, comprising 1662 injections performed by 120 dental students, the number of aspirations, which were positive for blood was recorded. The highest frequency of positive blood findings in the cartridges by aspiration was found with the mandibular block injections (11,3 per cent). The results are similar to those described in earlier investigations, in which experienced clinicians made the injections. Thus, the clinical experience does not seem to be of determining importance in this connection.

Fifty women aged 75 years or older who were living alone were visited to determine their self perception of dependency. There was a wide variety in reported capacity for self care but two patterns are isolated: those who were active initiators with a self perception of independence and passive responders with a perception of dependence. Service providers should take cognisance of the woman's self perception in the effective delivery of services.

Dienamine I is a versatile intermediate for the total synthesis of modified steroids, Several examples of its application have been recently communicated from this laboratory3,4. We now wish to report the conversion of dienamine I into a 5,10-diazasteroidal system via a sequence of simple steps which are of general application to the total synthesis of this class of steroids5.