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The inhibitory effect (allelopathic potential) of shoot, seed and root extracts of 8 white, 5 red and 5 black rice (Oryza sativa L.) cultivars was determined against the seedling growth of lettuce (Lactuca sativa L.) and white clover (Trifolium repens L.). All extracts inhibited hypocotyl and root growth of lettuce and white clover seedlings, and those inhibitory activities ranged from –1% – 96%. The average inhibitory activity of the extracts on the hypocotyl and root growth of lettuce and white clover was 42 – 88%. No apparent difference in the inhibitory activity was found either among the extracts of white, red and black rice, or among the extracts of shoots, seeds and roots. However, the red rice cultivar Tsushima-akamai marked the greatest inhibitory activity with an average of 88% growth inhibition on hypocotyls and roots of lettuce and white clover, followed by Souja-akamai and Koshihikari. These results suggest two red rice, Tsushima-akamai and Souja-akamai, may be potentially useful for weed management in agriculture.

In this paper, we numerically investigate the influence of multi-interchannel optical crosstalk in a 25-GHz spaced dense-wavelength division multiplexing (DWDM) millimeter-wave-band radio-over-fiber (RoF) downlink system. Up to 31 undesired RoF signals were intentionally mixed as the crosstalk with the desired RoF signal. We define the suppression ratio of the crosstalk as the ratio of the mm-wave power of the desired channel to the undesired channels which are estimated from optical spectrum of the detected RoF signal. The simulation results show that the receiver sensitivity degradation due to the crosstalk can be fairly well predicted with the measurable suppression ratio regardless of the total DWDM channel number.

La reaction d'aldehydes avec des halogeno-1 alcanes et du chlorure de chrome II, en presence de vitamine B 12 ou d'un complexe phtalocyaninique du cobalt, conduit a la reduction selective de la fonction aldehyde par rapport aux cetones ou esters

Treatment of an aldehyde in THF at −30°C with a reagent derived by reduction of acrolein dialkyl acetal with CrCl2 in the presence of Me3SiI gave 1,2- erythro -3,4-butene-1,2-diol derivatives selectively.

The effects of hypertonic mannitol on postischemic cerebral circulation were studied in 20 dogs. Mannitol, 2 g/kg iv, was infused into ten dogs during a 2-h period starting 1.5 h after 6 min of complete cerebral ischemia. One hour postischemia, regional cerebral blood flow (rCBF) was 36% in the control group (ten dogs) and 39% in the mannitol group. In the control group, rCBF increased gradually thereafter to 70% of the preischemic value 10 h postischemia, whereas the restoration of rCBF was suppressed in the mannitol group. During the postischemic period, intracranial pressure (ICP) increased significantly in the control group, but it did not change significantly in the mannitol group. The effects of mannitol on rCBF and ICP in the present study can be explained primarily by decreased body water due to urinary loss. The administration of mannitol does not necessarily improve postischemic cerebral circulation.

The following parameters were monitored simultaneously in 15 dogs, in order to evaluate the efficacy of conventional CPR (C-CPR), new CPR (N-CPR), and open-chest CPR (O-CPR) on cerebral perfusion: arterial blood pressure (BP), central venous pressure (CVP), intrathoracic airway pressure, blood flow in carotid artery, intracranial pressure (ICP), sagittal sinus blood flow (sinus BF) and pressure (sinus P), and blood flow in cerebral cortex (cortical BF). The sinus blood flow was measured by the direct-method and with a cannulating electromagnetic flowmeter. The cortical blood flow was measured with a termocouple tissue flowmeter. Intracranial pressure was obtained by measuring subarachmoid cerebrospinal fluid pressure. Ventricular fibrillation was induced electrically. Chest compression and ventilation were always done manually in all cardiopulmonary resuscitation. The mean blood pressures during C-CPR, N-CPR and O-CPR were 52, 68 and 95 mmHg, respectively, and mean carotid blood flows per stroke were 36, 71 and 131% of the control values, respectively. The intracranial pressures were 30, 42 and 36 mmHg, respectively, giving the calculated cerebral perfusion pressures (BP-ICP) of 22, 27 and 60 mmHg, respectively. This should have been reflected in cerebral blood flow. Sinus blood flows/min were 18, 18 and 42%, and sinus blood flows per stroke were 55, 45 and 127% of control values, respectively; the differences between C-CPR and N-CPR were not significant. This was also true for cortical blood flow. From this we conclude that, firstly, N-CPR is not significantly better than C-CPR in cerebral perfusion because of its accompanying high intracranial pressure, secondly, O-CPR is far superior to the other two methods in respect of cerebral perfusion.

La reaction d'aldehydes avec des halogeno-1 alcanes et du chlorure de chrome II, en presence de vitamine B 12 ou d'un complexe phtalocyaninique du cobalt, conduit a la reduction selective de la fonction aldehyde par rapport aux cetones ou esters

Reductive coupling of the acetals (I) with the aldehydes (II) in the presence of chromium(II) chloride and iodotrimethylsilane gives the hydroxyalkenyl ethers (III).