Combined radiometric and electrochemical study of the behaviour of Tc (vii) ions at gold and platinized surfaces in acidic media

The sorption and deposition of technetium species formed from TcO ₄ ^– at gold and platinized surfaces was followed by a coupledin situ radiometric and electrochemical technique. It was found: (i) that a layer of TcO₂ species is formed preceding the massive deposition of technetium species, and (ii) that the deposition process is not connected with hydrogen evolution or reaction with adsorbed hydrogen as has been assumed in the literature. An important new finding, the electrocatalytic reduction of ClO₄ ions at surfaces covered by technetium species, was demonstrated on the basis of a comparative study of the phenomena observed in H₂SO₄ and HClO₄ supporting electrolytes.This paper is dedicated to Professor Brian E. Conway on the occasion of his 65th birthday, and in recognition of his outstanding contribution to electrochemisty.     

Experimental electrocoagulation of dog esophageal and duodenal mucosa

The per review system for the assessment of research proposals is widely respected by working scientists. Nevertheless two problems associated with the operation of this system by the US National Institutes of Health are identified. First the scientist has no control over which committee will review an application and it may be considered by a quite inappropriate group. Second analysis of the committee composition suggests that in some of the groups several members are not active scientists and therefore not the "peers" of the applicant.     

Leucinosis--a case of congenital metabolic disease in a child

Trasditional Chinese medicine is based on inductive-synthetic reasoning with regard to all life processes, in contrast to the causal-analytic orientation in our Western medicine. This philosophical approach is based on a system of comparisons (equivalents), referred to as Yin and Yang. Vital functions are seen as "energizing" processes, whereby the acupuncture points and the system of meridians are seen as a means of regulation for this "energy". A disturbed balance in this energy results in illness. The therapy according to the acupuncture method is to acheive a balance in the disturbed flow of energy by means of acupuncture points. By utilizing biophysical methods of measurement, it is possible to prove that a change in this energy takes place. The complex active principle which results in the effectiveness of acupuncture includes neurophysiological, biochemical and biophysical functional processes.     

Observation of a half-quantum-flux periodicity pattern in an rf SQUID with small critical currents

We have found experimentally that rf SQUID's working in a nonhysteretic mode with small critical currents give exactly at resonance and at very low rf bias a triangular pattern with a period equal to half of one elementary quantum of magnetic flux. We discuss a possible explanation of this peculiar result.     

Pigmentary glaucoma? Relations to megalocornea

The student population at Edinburgh University was surveyed in 1974 to collect data on women's menstrual cycles and to examine sources of individual differences in reporting symptoms associated with the cycle. 2542 non-oral contraceptive (OC) users and 756 OC users provided data. Both sets of respondents were questioned about the occurrence, both premenstrually and during menstruation, of 9 symptoms. The "physical" symptoms (stomachache, backache, nausea, fainting) were more often reported during menstruation, whereas the so-called "emotional" symptoms (lethargy, irritability, depression, tension, headache) had a greater prevalence premenstrually. When the 9 menstrual symptoms were broken down by students' fields of concentration, arts students were found to report more "emotional" symptoms than those in the sciences and professions (medicine and law). Further analysis showed that only and 1st born children were slightly less likely to report symptoms than those whose nearest sibling is 7 or more years older or younger or later born children. A similar trend was found for the reporting of illness in an earlier analysis of data from this sample. When cycle length and reqularity were analyzed together, women with long and regular cycles were found to have the lowest proportion reporting symptoms during menstruating with the exception of tension, nausea, and fainting, and women with short and irregular cycles had a correspondingly high incidence of all symptoms. In addition, women with more regular cycles were more likely to report infrequent recall of dreams than those with irregular cycles. Overall, the women who are most likely to report menstrual symptoms, especially those of an "emotional" character, are more likely to report other illnesses with emotional connotations, recall their dreams more frequently, show a preference for the arts, and tend to have been brought up with older siblings. This cluster of personality attributes defines an "expressive" personaltiy in contrast to the more "controlled" style of women at the other extreme.     

The psychological development of orphanage-reared infants: interventions with outcomes (Tehran)

This paper describes five successive interventions in the rearing of infants at an orphanage in Tehran, with their outcomes. The outcomes were assessed longitudinally. The first of the successive groups, here called "waves", numbered 15. These Ss constitute the controls. The only intervention consisted of examining the infants every other week during the first year and every fourth week thereafter with the ordinal, sensorimotor scales of Uzgiris and Hunt. The audio-visual intervention intended for the second wave of 10 infants was tape-recorded mother talk and music under the control of the infants and mobiles that the infants could activate. This plan was never adequately implemented because of inadequate supervision. The third wave of 10 infants got extra untutored human care. The fourth wave of 20 infants got the kind of audio-visual intervention originally intended for the second wave plus access to responsive inanimate materials. For the fifth wave, numbering 11, the infant-caretaker ratio was reduced to two or three to one and the caretakers were taught the Badger program supplemented with procedures to foster vocal imitation and semantic mastery of body parts, clothing, toys, and other objects and events regularly encountered. The results show that each successive wave, excepting the second, achieved the top steps of nearly all seven of the ordinal scales at mean ages younger than the preceding wave, and the fifth wave surpassed even home-reared American children from predominantly professional families in achieving the top steps on five of the seven scales. The findings show that infants need not advance along all branches simultaneously and that the kinds of experience encountered determine the branch along which advancement occurs. A number of theoretical implications are examined. Especially important is the idea that a dependable educational psychology for infancy and early childhood calls for much more knowledge than we now have of the kinds of experience that advance development along each of the various branches.     

Relative importance of growth hormone and sex steroids for the growth at puberty of trunk length, limb length, and muscle width in growth hormone-deficient children

We have followed the growth of stature, sitting height, skinfolds, muscle widths measured radiologically, and skeletal maturity in growth hormone-deficient patients in whom hGH was given and withheld in alternating three-month periods throughout puberty (referred to as "off-hGH" and "on-hGH" periods). Six boys and four girls had true isolated GH deficiency and developed puberty spontaneously. Two boys had gonadotrophin deficiency plus GH deficiency, and five boys had multiple deficiencies; in these boys the signs of puberty were induced by hormone treatment. Boys with true isolated deficiency grew about two-thirds as much in height in the off-hGH periods as in the on-hGH periods; their total gain in height during the adolescent spurt would have been about 20 cm, instead of 30 cm, if hGH had been discontinued at the beginning of puberty. The effect of hGH was entirely on growth in leg-length, however, which virtually ceased during the off-hGH periods. Growth in sitting height altered little when hGH was withdrawn. Growth in limb muscles, however, was GH dependent throughout puberty; during the majority of periods when hGH was withheld, muscle was actually lost; this occurred in the boys who were receiving large doses of testosterone as well as in those producing their own normal amounts. Subcutaneous fat diminished when hGH was given and increased when it was withdrawn; this occurred independently of administration of testosterone. There was little evidence that growth of pubic and axillary hair progressed faster during on-hGH periods, except perhaps in patients with multiple deficiencies. There was some evidence, however, that bone age progressed less rapidly during on-hGH periods than during off-hGH periods in the patients with isolated deficiency. The results in the girls agreed with those in boys so far as stature was concerned, but the relationship with sitting height and leg length appeared to be different; the reasons for this are discussed. We conclude that all children with GH deficiency should continue on treatment with hGH throughout puberty, ideally until growth ceases.     

Effect of prolactin suppression on gonadotrophic secretion in the puerperium

Serum levels of prolactin (PRL), FSH, LH and oestradiol-17 beta were determined by radioimmunoassay in 57 lactating women and in 20 women in whom lactation was inhibited by ergocryptine (CS-154). Women who breast fed their infants exhibited high PRL levels which abruptly declined within 48 h post-partum, and remained low for the duration of the study. Serum FSH was undetectable during the first week post-partum in lactating as well as in CB-154 treated women. Thereafter, lactating women showed increasing FSH levels which reached a maximum by the third week post-partum. These FSH values were higher in lactating women than in the CBS-154 treated group. In contrast, LH levels were higher in those women receiving CB-154. Serum oestradiol-17 beta remained in low levels throughout the study, and no difference was observed between the two groups of subjects. From these results it seems that: 1) inhibition of PRL secretion leads to a faster recovery of gonadotrophin secretion toward the "menstrual type", and 2) PRL suppression produces no effect on the ovarian oestrogen production.     

Synthesis, structure, and field emission properties of sulfur-doped nanocrystalline diamond

The synthesis and properties of sulfur-doped nanocrystalline diamond films were investigated. The films were deposited by hot-filament chemical vapor deposition on Mo substrates using methane, hydrogen, and hydrogen disulfide. The nanocrystalline nature of the material arises from the induction of continuous secondary nucleation in the chemical vapor deposition environment. Complementary characterization tools were employed in order to obtain a comprehensive and coherent understanding of the correlations between the structural and electronic properties. In particular, sulfur-doped nanocrystalline diamond films show n-type Hall conductivity, enhanced field emission properties, and insensitivity to ion radiation. It was found that n-type doping of the tetragonally-bonded carbon matrix together with a nano network of trigonally-bonded carbon are crucial elements for enhanced field emission from nanocrystalline diamond. These conclusions and the corresponding supporting evidence are discussed.     

Patterns of international scientific co-operation in Puerto Rico

Scientific activity has been increasing in Puerto Rico in recent years, a development mirrored not only by the amount of papers published, but by the international links established for scientific co-operation. The purpose of the present study is to identify and discuss the patterns of such co-operation, along with the trends in scientific research conducted in that context at Puerto Rican institutions. The methodology includes an analysis of the main areas of research addressed, defined as the area of specialization of the journals publishing papers indexed in the Science Citation Index (CD-ROM version) from 1980 to 1999. A total of 7271 studies, appearing in 1240 scientific journals, were selected to study the co-operation established between Puerto Rican institutions and organizations in other countries. The findings showed a high rate of international co-operation: 46.07% of the papers published were co-authored by researchers from other countries. The country accounting for the highest percentage of joint research was the USA, followed by Germany, United Kingdom, Canada and Italy. The close relationship between the Puerto Rican and US scientific systems is not unusual, inasmuch as the economic and socio-political bonds between them play an essential role in Puerto Rican scientific activity. The results also revealed substantial differences between the nineteen eighties and the nineties in terms of the nature of the links established, as well as growing internationalization of scientific research conducted on the island over the twenty-year period studied.