Impact of mechanical and thermo-chemical pretreatments to enhance anaerobic digestion of poly(lactic acid).

To date, the introduction of biodegradable plastics such as PLA in anaerobic digestion systems has been limited by a very low rate of biodegradation. To overcome these limitations, pretreatment technologies can be applied. In this study, the impact of pretreatments (mechanical, thermal, thermo-acid, and thermo-alkaline) was investigated. Mechanical pretreatment of PLA improved its biodegradation rate but did not affect the ultimate methane potential (430-461 NL CH4 kg-1 VS). In parallel, thermal and thermo-acid pretreatments exhibited a similar trend for PLA solubilization. Both of these pretreatments only achieved substantial solubilization (>60%) at higher temperatures (120 and 150 °C). At lower temperatures (70 and 90 °C), negligible solubilization (between 1 and 6%) occurred after 48 h. By contrast, coupling of thermal and alkaline pretreatment significantly increased solubilization at the lower temperatures (70 and 90 °C). In terms of biodegradation, thermo-alkaline pretreatment (with 5% w/v Ca(OH)2) of PLA resulted in a similar methane potential (from 325 to 390 NL CH4 kg-1 VS) for 1 h at 150 °C, 6 h at 120 °C, 24 h at 90 °C, and 48 h at 70 °C. Reduction of the Ca(OH)2 concentration (from 5% to 0.5% w/v) highlighted that a concentration of 2.5% w/v was sufficient to achieve a substantial level of biodegradation. Pretreatment at 70 and 90 °C using 2.5% w/v Ca(OH)2 for 48 h resulted in biodegradation yields of 73% and 68%, respectively. Finally, a good correlation (R2 = 0.90) was found between the PLA solubilization and its biodegradation.

[Pilot study of arterial blood pressure in the school children of Girona and its province]. / Estudio piloto de la tensión arterial escolar de Girona y provincia.

UNLABELLED: The arterial blood pressure was measured in 1,494 school children (810 boys and 684 girls) 5 to 14 years old who attended 46 schools in the province of Girona. OBJECTIVE OF THE STUDY: to establish the distribution of arterial blood pressure in school children in our community in empirical percentiles according to chronologic and anthropometric variables (age, height, weight and body surface). In our study the systolic arterial blood pressure increased significantly (p less than 0.001) in both sexes in all the variables studied. The simple correlations in decreasing order were, in boys: body surface, weight, height and age, and in girls: weight, body surface, height and age. However, there was no correlation between the diastolic arterial blood pressure in either sex with the variables studied.

Arthropathy and cutaneous calcinosis in hemodialysis oxalosis.

Recently, calcium oxalate crystals have been identified in the synovial fluid of patients with arthritis and end-stage renal failure. We describe 4 patients who, during the course of long-term hemodialysis, developed calcium oxalate crystal deposits in the synovium and skin. Clinical manifestations included podagra, tenosynovitis, olecranon bursitis, and acute and chronic synovitis of the large joints that were associated with chondrocalcinosis or subchondral bone erosions. Diffuse involvement of the hand, with chondrocalcinosis of the finger joints, miliary calcified deposits in the skin, and artery calcifications, was observed in 3 patients. The fourth patient had erosive arthropathy. Oxalosis secondary to end-stage renal failure in patients treated with long-term hemodialysis can present with articular manifestations that resemble those of gout, pseudogout, and apatite deposition disease. Other characteristic features of the synovitis associated with oxalosis secondary to end-stage renal disease were: predominant involvement of the hand, mild inflammatory changes in the synovial fluid and synovium, and poor response to administration of nonsteroidal antiinflammatory agents.

[Uremic pericarditis. Preliminary evaluation of treatment with indomethacin (author's transl)]. / Pericarditis urémica. Valoración inicial del tratamiento con indometacina.

Numerous therapeutic schemes have been proposed for pericarditis, whether or not accompanied by pericardial effusion in patients with terminal chronic renal insufficiency of subjects on periodic hemodialysis. All of the authors agree that dialysis must be initiated, or at least must not be interrupted once it is begun. There is some disagreement over the system that should be used (peritoneal dialysis or hemodialysis). Anti-inflammatory drugs have been used in association, since the condition is an inflammatory disease. Five episodes of pericarditis with daily hemodialysis and local heparine were treated, plus five other cases with the addition of 3 mg indomethacin/kg/day for 8 days. No secondary effects of indomethacin were reported. A definite reduction in the duration of pain, fever, pericardial rub, and increase in the size of the cardiac shadow was seen in the episodes treated with the association of indomethacin. This furthermore involved the number of days the patient was subjected to hemodialysis. Partial pericardiectomy was practiced on two patients not treated with indomethacin. The later course of the patients treated with indomethacin was more favorable since pericardial effusion did not lead to significant hemodynamic symptoms. There were no recurrences or other complications.