Electrochemical regeneration of hexavalent chromium from aqueous solutions in a gas sparged parallel plate reactor.

In this study anodic oxidation of Cr2(SO4)3 was carried out in an air-sparged divided parallel plate cell. Variables studied were current density, Cr2(SO4)3 concentration, and superficial air velocity. The rate constant of Cr2(SO4)3 oxidation was found to increase with increasing current density and Cr2(SO4)3 concentration. The effect of air sparging was found to depend on Cr2(SO4)3 concentrations, at high Cr2(SO4)3 concentration (> 0.1 M) air sparging does not affect the rate constant of the reaction denoting that the reaction is charge transfer controlled. As Cr2(SO4)3 concentration decreases below 0.1 M the reaction becomes under mixed diffusion and chemical control and the rate constant increases with increasing air superficial velocity, the lower Cr2(SO4)3 concentration the higher the contribution of diffusion to the reaction rate. The current efficiency of the process ranged from 20 to 85% depending on current density and Cr2(SO4)3 concentration. Electrical energy consumption which ranged from 1.8 to 14.4 kW h/kg of Cr6+ was found to increase with increasing current density and decreases with increasing Cr2(SO4)3 concentration. Air sparging was found to decrease electrical energy consumption in the case of dilute solutions << 0.1 M Cr2(SO4)3.

Bioassays guided isolation of compounds from Chaetomium globosum.

The aim of the present study was to evaluate different biological activities of the fungus Chaetomium globosum (family Chaetomiaceae). The evaluation was done through testing its antimicrobial, antioxidant and anticancer effects. C. globosum was isolated from the Cucumber soil (rhizosphere) and caused inhibition of the mycelial growth of Fusarium solani, Rhizoctonia solani and Sclerotium rolfsii in the biculture test. Petroleum ether and ethyl acetate extracts of the liquid culture of C. globosum showed potent in vitro antioxidant activity. C. globosum proved potent antibacterial activity against Bacillus subtilis, Escherichia coli and Pseudomonas fluorescens. It also recorded significant antifungal activity against Candida albicans, F. solani, Fusarium oxysporum, R. solani and Pythium ultimum. It exerted cytotoxic effect on human hepatocellular carcinoma cell line (HepG2). Unsaponifiable and saponifiable matters of the petroleum ether extract showed the presence of hydrocarbons, sterols and fatty acids. The ethyl acetate extract showed the presence of prenisatin, chrysophanol, chrysazin, chaetoviridin A and B. The isolated secondary metabolites proved significant antioxidant and antimicrobial activity on B. subtilis, E. coli and R. solani. In conclusion, this fungus showed different biological activities. Further studies must be done to apply its use in the agricultural and medicinal field.

Bilateral intrapleural regional analgesia for postoperative pain control: a dose-finding study.

Postoperative pain management for major abdominal or thoracoabdominal procedures requires bilateral multisegmental intercostal nerve blocks or epidural analgesia. This study was undertaken to examine the possible role of bilateral intrapleural regional analgesia (BIRA) and to select the proper dose for this new technique. Bilateral intrapleural catheters were inserted after surgery, using a Mancao dual-cannula system. Bupivacaine with epinephrine 1/200,000 (BE) was administered in each side as 20 mL of 0.5% in three patients. When this dose was found to be ineffective, 30 mL of 0.75% BE was administered in five patients; however, two patients complained of tinnitus and visual disturbances. Subsequently, 20 mL of 0.75% BE was used in five patients and was found to be satisfactory. Thirteen additional patients received the latter dose. Arterial blood levels of bupivacaine were determined at 15, 30, 60, and 120 minutes. The group of 18 patients (group I) who received 20 mL of 0.75% BE bilaterally were compared with a second group (group II) of 16 patients undergoing similar surgery who received only parenteral narcotics for pain management. BIRA was considered effective when patients denied pain or discomfort and when narcotics were not required in the postanesthesia recovery unit. Patients in groups I and II received narcotic medication whenever they felt pain or discomfort. The duration of BIRA was considered to be from the injection of the drug until the time a narcotic was administered to the patient. Demographic variables, changes in BP and heart rate after surgery, frequency of narcotic administration during the first four postoperative days, and postoperative hospital stay were compared in groups I and II.(ABSTRACT TRUNCATED AT 250 WORDS)

Intrapleural regional analgesia for pain management in cholecystectomy.

Fifty patients undergoing cholecystectomy either electively or urgently were treated in the postoperative period with the intrapleural injection of 30 mL of 0.75% bupivacaine hydrochloride with epinephrine (1:200,000). The frequency of narcotic administration and the postoperative stay were compared with those of 50 historical controls. The group receiving intrapleural regional analgesia had significant, prolonged pain relief requiring minimal narcotic analgesics in the first 24 hours postoperatively and had a significantly shortened hospital stay. There were no complications related to catheter insertion or bupivacaine toxic effects. This technique is safe and effective in controlling perioperative pain.

Diazepam-ketamine anaesthesia for open heart surgery a "micro-mini" drip administration technique.

Two hundred open-heart cases were anaesthetized with a diazepam-ketamine combination. The results were excellent. A "Micro-Mini" drip technique insured low, even, but adequate dose levels of ketamine and less drug was used. Induction and maintenance are simple and smooth. Effects on the cardiovascular system and respiratory system are minimal. The margin of safety is wide and 100% oxygen can be used whenever needed.

Diazepam-ketamine anaesthesia for open heart surgery "micro-mini" drip administration technique.

Two hundred open heart cases anaesthetized with a combination of diazepam-ketamine using "Micro-Mini" drip administration technique were presented. The results were eminently desirable, and in the opinion of the authors are a notable improvement over other methods for all types of cardiovascular surgery including most advanced heart diseases. The advantages of this anaesthetic method for cardiovascular surgery are as follows: 1. Effects on cardiovascular system are minimal.--2. Respiratory depression is negligible.--3. There is no increase in salivation or muscle tone.--4. Induction and maintenance of anaesthesia are simple and smooth.--5. Anaesthesia can be maintained, using a high concentration of oxygen alone, by a slight increase in rate of ketamine administration whenever necessary.--6. Post-anaesthetic psychotomimetic effects are negligible.--7. Nearly 100% of patients have excellent amnesia.--8. It has a wide margin of safety.--9. This technique has proved highly acceptable to patients and surgeons. We feel ketamine should be used in small dosages continuously administered with either "Micro-Mini" drip infusion or infusion pump. Ketamine given in this fashion should be regarded as an analgesic.