A new method for estimating solar radiation from bright sunshine data

Daily values of H/H₀, the ratio of total horizontal radiation to that outside the atmosphere has been correlated with s/S, bright sunshine as a fraction of daylength for 3 yr measurements in Adana and Ankara, Turkey. Using a maximum-likelihood quadratic fit, we show that monthly averages s/S and its standard deviation σ_s/S can be used to estimate the monthly average H/H₀ as

H/H₀ = 0.204 + 0.758s/S − 0.250[s/S² + σ²_s/S.

Comparison of the estimations of the above equation with measurements from different regions of Turkey indicate that less than 5 per cent relative error is possible. A further correlation σ²_s/S with s/S makes it possible to estimate H/H₀ with just the knowledge of s/S.     

Marchantinquinone, isolated from Reboulia hemisphaerica, as inhibitor of lipid peroxidation and as free radical scavenger

Recent years have witnessed a renewed interest in plants as pharmaceuticals in the Western world. This interest is channeled into the discovery of new biologically-active molecules by the pharmaceutical industry and into the adoption of crude extracts of plants for self-medication by the general public. In both of these areas some attention is being paid to the investigation and use of ethnopharmacology, the traditional use of plants for medicinal purposes by particular cultural groups. Ethnopharmacologic leads have resulted in the introduction of new single molecule drugs but have a greater role to play if crude extracts are accepted for clinical use in the West. The problems confronting such usage are discussed. Considerable benefits for developing countries are possible when the local medicinal plants are subjected to scientific methods of validation of traditional use and quality control. This approach has met with success in some parts of the world but is not always appreciated by national governments and international agencies. Related areas of concern such as conservation of ecology and culture must be integrated with any such program. Plants used in traditional medicine therefore have an important role to play in the maintenance of health in all parts of the world and in the introduction of new treatments.     

Outcome of moderate carotid artery stenosis in patients who are asymptomatic

PURPOSE: The incidence rate of disease progression and stroke after the diagnosis of a moderate (50% to 79%) carotid stenosis was determined by means of color-flow duplex scanning. METHODS: During a 4-year period, 344 male veterans with moderate internal carotid artery stenoses, on one or both sides, were examined at regular intervals for a mean period of 25 months. Carotid color-flow scans were obtained semiannually. Clinical follow-up was performed to determine the incidence rate of amaurosis fugax, transient ischemic attacks, nonhemispheric symptoms, and strokes. RESULTS: New neurologic symptoms developed in 75 patients (21.8%). Fifty-one (14.8%) had ipsilateral symptoms during follow-up: 18 amaurosis fugax (5.2%), 14 transient ischemic attacks (4%), 5 nonhemispheric symptoms (1.4%), and 14 strokes (4%). Twenty-four patients (6.9%) had contralateral symptoms: 20 strokes (5.8%) and 4 transient ischemic attacks (1.2%). Life-table analysis showed that the annual rate of ipsilateral neurologic events was 8.1%, and the annual rate of stroke was 2.1%. Seventy-five patients (22%) died in the follow-up period. Disease progression to 80% to 99% stenosis or occlusion occurred in 71 of 458 vessels (15.5%). The internal carotid arteries that showed evidence of disease progression had a significantly higher initial peak systolic velocity (251 vs 190 cm/s; P <.0001) and end diastolic velocity (74 vs 52 cm/s; P < 0.0001). Black patients and patients with ischemic heart disease were at a higher risk for disease progression. We could not identify any atherosclerotic risk factors that reliably predicted patients in whom future ipsilateral neurologic symptoms were more likely to develop. However, there was an increased risk of stroke associated with progression of disease. CONCLUSION: Patients who are asymptomatic and who have moderate carotid stenoses are at significant risk for neurologic symptoms and death, but have a relatively low incidence rate of ipsilateral events. The initial flow characteristics in the stenotic vessel are predictive of future disease progression, but they are not helpful in identifying patients in whom symptoms will develop.     

Immobilization of acrylamide-modified oligonucleotides by co-polymerization

A flexible chemistry for solid phase attachment of oligonucleotides is described. Oligonucleotides bearing 5'-terminal acrylamide modifications efficiently co-polymerize with acrylamide monomers to form thermally stable DNA-containing polyacrylamide co-polymers. Co-polymerization attachment is specific for the terminal acrylamide group. Stable probe-containing layers are easily fabricated on supports bearing exposed acrylic groups, including plastic microtiter plates and silanized glass. Attachment can be accomplished using standard polyacrylamide gel recipes and polymerization techniques. Supports having a high surface density of hybridizable oligonucleotide (approximately 200 fmol/mm2) can be produced.     

Intraperitoneal chemo-hyperthermia with mitomycin C in cancer of the stomach with peritoneal carcinosis

We report 42 cases of gastric cancer with peritoneal carcinosis treated with intraperitoneal chemohyperthermia. Intraperitoneal chemohyperthermia was achieved with a closed sterile circuit containing mitomycin C, 10 mg/l producing an input temperature varying from 46 to 49 degrees C for 90 minutes. There were three postoperative deaths: one pulmonary embolism at day 4, one multiple organ failure et day 4, and one septic shock at day 25 due to a colonic fistula. Two patients suffered complications: one opening of the duodenal stump requiring reoperation on day 5, and one prolonged postoperative ileus lasting to day 10. Of the 12 patients with ascites, resorption was achieved in 8. In patients with early-stage peritoneal carcinosis (granulations less than 5 mm) survival at 1, 2 and 3 years was 90%, 61% and 41% respectively. For those with more extensive carcinosis, survival at 1 year was 10%. Five patients survived more than 30 months, three have survived to 34, 43 and 73 months. Intraperitoneal chemohyperthermia is a new treatment for carcinosis of gastric origin. These early results must be assessed further with larger controlled.