Measurement of ion energy distributions using a combined energy and mass analyzer.

A method is described for measuring ion energy distributions using a commercially available, combined energy analyzer/mass spectrometer. The distributions were measured at an electrode located adjacent to pulsed, electron beam-generated plasmas produced in argon. The method uses energy-dependent tuning and was tested for various plasma conditions. The results indicate an improved collection efficiency of low-energy ions when compared to conventional approaches in measuring ion energy distributions.

Time-resolved ion flux measurements in pulsed, electron-beam-generated plasmas.

Time-resolved ion flux and energy distributions were measured at an electrode located adjacent to pulsed, electron-beam-generated plasmas in argon and oxygen. Temporal variations in the incident Ar+, O+, and O(2)+ energy and flux were correlated to changes in the electron temperature and plasma density. The decay time of the oxygen plasma is found to be shorter than that of the argon plasma, which is understood by considering the different loss mechanisms of each ion species.

Relationship between perceived parental monitoring and young adolescent girls' sexual and substance use behaviors.

STUDY OBJECTIVE: The purpose of the study was to examine the independent effects of perceived parental monitoring on sexual experience, contraceptive, and substance use. DESIGN, SETTING, AND PARTICIPANTS: Adolescent females at an urban-based adolescent clinic (N = 174; 41% sexually experienced) rated the extent to which they were directly and indirectly monitored by their parents. MAIN OUTCOME MEASURES: These perceptions were compared with reported contraceptive use as well as substance use. Direct parental monitoring was best described using two dimensions: direct monitoring and direct monitoring when with peers. RESULTS: Direct monitoring was found to be associated with the use of hormonal birth control methods at last intercourse. Direct parental monitoring when with peers was found to be associated with less use of alcohol and cigarettes. CONCLUSIONS: These data suggest that parental monitoring is a relevant factor for primary care physicians to explore during treatment.

Equitable distribution in pediatric heart transplantation. Arguments in favor of a national list.

The disparity between the supply and demand for pediatric donor hearts remains the major constraint in pediatric heart transplantation. This disparity draws attention to the importance of an equitable distribution policy for pediatric hearts. An examination of the policy on pediatric heart distribution shows that although a governmental task force recommended that these organs be allocated according to a national list, the current policy, developed by the United Network of Organ Sharing, emphasizes the local distribution of pediatric hearts. The decision to allocate organs locally was based on both theoretical and practical concerns about national distribution. In analyzing these concerns, we conclude not only that a national list may be a more equitable means of distribution but also that the arguments against a national list no longer justify a policy favoring local distribution. We suggest, therefore, that the time has come to reconsider implementation of a national list for pediatric heart distribution.

Perinatal toxicity of ethylene glycol dimethyl ether in the rat.

Ethylene glycol dimethyl ether (EGdiME) was administered by gavage to pregnant Sprague-Dawley rats in doses of 30, 60, 120, 250, 500, and 1000 mg/kg/day from day 8 through day 18 of gestation. The effects of the compound on maternal weight gain, length of gestation, perinatal mortality, teratogenicity, average fetal weight on day 19, and average pup weight one day after birth were assessed. A clear pattern of dose-dependent maternal and fetal toxicity was observed. EGdiME caused maternal deaths at 1000 mg/kg/day and was fetolethal at doses ranging from 120 to 1000 mg/kg/day. A dose of 60 mg/kg/day resulted in a 7% weight decrease and severe edema in pups surviving to birth. Skeletal examinations in this group revealed fetotoxicity as evidenced by the lack of ossified bone, but there was no indication of anomalies in soft tissues. The same concentration in dams allowed to go to term resulted in a delay in the onset of parturition and produced litters with only one-third the number of live pups as controls. Of these, an average of less than 1 per litter survived to day 1 postpartum. The compound was not fetolethal on day 19 at a dose level of 30 mg/kg/day. Perinatal mortality in the interval between day 19 of gestation and birth was manifested, however, by an average reduction of 2 live pups per litter at birth. There was a close correlation between the fetotoxic effects of the various concentrations and the degree to which the maternal weight gain pattern of each departed from the control profile.

[Prevention of venous thromboses and cutaneous necroses using physical methods and pressure therapy in the surgery of chronic venous insufficiency of the lower limbs]. / Prévention des thromboses veineuses et des nécroses cutanées par les méthodes physiques et la pressothérapie dans la chirurgie de l'insuffisance veineuse chronique des membres inférieurs.

The surgical treatment of chronic venous insufficiency in the lower limbs, whether it is a case of so-called 'essential' varices or of post-phlebitic disorders, presents a certain number of risks of venous thrombosis and especially of cutaneous necrosis or of cicatricial detachment in operations of the Lindon or Felder type. Given a less significant set-back, it has been suggested that restorative surgery of the deep venous network, valve repair or insertion of a valvulated section, should be used in the treatment of post-phlebitic illness. Promising results have been obtained through specific kinesitherapy, involving a Leduc type manual lymph drainage together with pressotherapy, in the preparation of patients and in post-operative follow-up care.