(e,3e) on helium at low impact energy: the strongly correlated three-electron continuum.

Double ionization of the helium atom by slow electron impact (E(0)=106 eV) is studied in a kinematically complete experiment. Because of a low excess energy E(exc)=27 eV above the double ionization threshold, a strongly correlated three-electron continuum is realized. This is demonstrated by measuring and calculating the fully differential cross sections for equal energy sharing of the final-state electrons. While the electron emission is dominated by a strong Coulomb repulsion, also signatures of more complex dynamics of the full four-body system are identified.

[The changes in plasma arginine-vasopressin in patients with essential hypertension and the correlation with patient's condition].

The levels of plasma arginine-vasopressin (AVP) in 80 patients with essential hypertension were measured, and its impact on the disease and its clinical significance were studied. The results showed that: (1) The levels of plasma AVP in patients with essential hypertension were significantly higher than that in normotensive subjects (P < 0.001). It dropped to normal level after antihypertensive drugs. (2) The concentrations of plasma AVP in both hypertensive subjects and normotensive subjects were not correlated with age and sex (P < 0.05). (3) The concentration of plasma AVP in patients with essential hypertension was the highest in stage III, the lowest in stage I, and middle in stage II. (4) The levels of plasma AVP in patients with malignant hypertension were significantly higher than that in patients with benign hypertension (P < 0.05). A positive correlation was found between the levels of plasma AVP and blood pressure (r = 0.3398, P < 0.01). (5) The concentrations of plasma AVP in hypertensive subjects with ventricular hypertrophy were higher than that in hypertensive subjects with out ventricular hypertrophy (P < 0.05). (6) The concentrations of plasma AVP in hypertensive subjects with heart failure were significantly higher than that in hypertensive subjects with out heart failure (P < 0.001). The results suggest that AVP has a role in the pathogenesis of hypertension, hypertension complicated with ventricular hypertrophy and hypertension complicated with heart failure. The levels of plasma AVP may be viewed as an index of the patient's condition in hypertensive subjects.

[The role of arginine-vasopressin and substance P in the pathogenesis of hypertension and their interrelation].

In this study, the concentration of plasma arginine vasopressin (AVP) and substance P (SP) in normotensive subjects as well as patients with essential hypertension was measured. The results showed that: (1) The concentration of plasma AVP in patients with essential hypertension (21.83 +/- 1.30ng/L) was significantly higher than that in normotensive subjects (11.02 +/- 1.05 ng/L) (P < 0.001). The level of plasma SP in hypertensive subjects (276.60 +/- 21.35 pmol/L) was obviously lower than that in normotensive subjects (958.20 +/- 31.13 pmol/L) (P < 0.001). (2) The level of plasma AVP decreased (from 24.88 +/- 1.63 to 8.69 +/- 1.39 ng/L, P < 0.001) and that of plasma SP increased (from 331.40 +/- 48.18 to 958.80 +/- 39.30 pmol/L, P < 0.001) after antihypertensive drug treatment. (3) A negative correlation was found between the level of plasma AVP and SP in patients with essential hypertension (r = -0.564, P < 0.001), but no correlation was found between them in normotensive subjects (r = -0.096, P > 0.05). It is suggested that the abnormal level of plasma AVP and SP plays a role in the pathogenesis of hypertension.