This work presents a Monte Carlo simulation of ion mixing of a multilayered target. The simulation deals with collisional effects and accounts for the dynamic alteration of the target under ion ...bombardment. The results refer to As implants, 190 keV, on a target composed of alternating Ni-Ta layers on a Si substrate.
Organic nitrates (nitroglycerin, isosorbide dinitrate) are inhibitors of platelet function more effective in vivo than in vitro (Am J Cardiol 1984; 53:1683), the in vivo effect requiring ...concentrations 10-100 times lower than in vitro. We have previously excluded that such difference is due to elicitation by nitrates of prostacyclin synthesis in human endothelial cells or vascular fragments (Circulation 1985; 71:176). In the present study we evaluated alternative explanations: that the difference is due (1) to generation of more active drug metabolites; (2) to synergism between nitrates and prostacyclin in the inhibition of platelet function. Isosorbide dinitrate (ISDN) and its two main in vivo metabolites, isosorbide-2-mononitrate (IS-2-MN) and isosorbide-5-mononitrate (IS-5-MN), were compared in their ability to inhibit platelet aggregation and thromboxane (TX) B2 formation (RIA) in respone to threshold doses of ADP, adrenaline, collagen, arachidonic acid and thrombin in citrated platelet-rich plasma. The same tests were performed in 10 healthy volunteers before, during (at 5, 15 and 30 min) and after infusion of the three drugs at 8 mg/h for 30 min in 3 different days. Finally, the concentration of prostacyclin (and its stable analogue Iloprost) added in vitro to platelets, and required to inhibit platelet aggregation by 50% (IC50) after 5 min pre-incubation of platelets with nitrates was determined. In vitro incubation of platelets with IS-2-MN resulted in greater inhibition of both aggregation and TX formation (by ADP and adrenaline) than with ISDN and IS-5-MN. At 10
−7
M, only IS-2-MN significantly inhibited aggregation (−12%, P< 0.05) and TX formation (from 9.2±1.8 to 5.9± 0.6 ng/ml) by ADP, while minimum effective concentrations were 10
−7
M for ISDN and 10
−7
m for IS-5-MN. These in vitro differences are unlikely to be the explanation of in vivo findings, since IS-2-MN, ISDN and IS-5-MN were equipotent when administered in vivo (complete abolition of secondary wave after ADP and adrenaline at 30 min of infusion). At supra-threshold doses of all the aggregating agents, all three drugs, at 10
−7
M, decreased IC50 for prostacyclin from 2.9± 1.3 to 0.32± 0.18 nM (P< 0.01). Synergim with prostacyclin is most likely to account, at least partially, for in vivo antiplatelet effects by organic nitrates.
Low dose implanted lithium depth profiles in preamorphized silicon have been measured in the energy range of 5 keV to 2 MeV by means of three different nuclear reaction techniques and SIMS ...measurements, and they are compared to theory. Though the agreement is good for the mean projected range, we find systematic deviations for the range straggling.
Further, the shapes of lithium depth profiles are studied as a function of the preamorphization dose. Also, the diffusion of li in amorphous Si was measured between - 18 and + 350°C. It is described by D = D
0
·exp(-E
A
/kT), the value of D
0
and E
A
ranging from those for purely interstitial diffusion (D
0
= 2 · 10
−(4±0.5)
cm
2
s
−1
and E
A
= 0.74 ± 0.5 eV) up to higher ones, which describe trap controlled diffusion (D
0
= 3 × 10
+(3±1)
cm
2
s
−1
and E = 1.74 ± 0.1 eV). A gradual transition between those extremes with diffusion time is observed.
This report summarizes the clinical and laboratory findings from a group of our patients and literature reviews from several families who have a genetic deficiency in three related leukocyte membrane ...surface antigens known as CR3,LFA-1, and p150,95. Each surface antigen has an identical beta-chain noncovalenty linked to one of three distinct alpha-chain types. Patients affected by this autosomal recessive disease have now been identified by several investigators. The patients have an increased susceptibility to bacterial infections that is similar to patients who have other types of neutrophil functional deficiencies or neutropenia. Laboratory tests have indicated that isolated neutrophils from these patients have two major types of functional deficiencies that probably contribute to their reduced ability to overcome bacterial infections. This review focuses exclusively on the phagocytic and cytotoxic abnormalities of neutrophils from these patients.
Two cases of moderate granulocyte adhesion glycoproteins complex deficiency are briefly discussed. These patients presented a clinical history of serious infections at various tissues and organs. ...Recently, the studies with monoclonal antibodies identified a new group of congenital granulocyte diseases.
