Advanced approach for screening soil with a low radiocesium transfer to brown rice in Fukushima based on exchangeable and nonexchangeable potassium.

Phytoavailable K in soil is a key to control the transfer factor of radiocesium from soil to brown rice. The transfer factors were determined for paddy fields cultivated in 2017 and 2018 under different K fertilization regimes in Fukushima Prefecture, Japan. Two phytoavailable forms of K, the exchangeable and nonexchangeable K contents were investigated for the surface soil sampled after the transplanting and fertilization as well as after harvest of rice in the same paddy fields. The exchangeable K content largely decreased from after transplanting and fertilization to after harvest, and the exchangeable K of the soil after harvest was negatively correlated with the transfer factor (rs = -0.70, p < .001). Most soil samples after harvest showed that the transfer factors exponentially increased as the exchangeable K decreased; however, some of the samples indicated considerably low transfer factors (<0.005) despite being exchangeable K deficient, i.e., exchangeable K < 25 mg K2O 100 g-1. Even though this value before usual fertilization has been effectively used as a threshold to determine whether supplemental K fertilization is required to reduce the radiocesium content in brown rice, additional screening was needed to estimate this radiocesium transfer more precisely. Thus, we found that not only the exchangeable K but also nonexchangeable K contents had a negative correlation with the transfer factor (rs = -0.60, p < .001) of the soil samples after harvest but were not correlated with each other (rp = -0.10). Furthermore, the results revealed that soil with nonexchangeable K > 50 mg K2O 100 g-1 indicated a considerably low transfer factor, even if exchangeable K deficient. Thus, via our field-scale experiments, we concluded that the criterion nonexchangeable K > 50 mg K2O 100 g-1 can be used as another threshold for use along with that of exchangeable K to differentiate soil with a low radiocesium transfer rate from exchangeable K deficient soil.

[Initial results of transurethral enucleation with bipolar system for benign prostate hypertrophy patients].

We have performed transurethral enucleation with bipolar system (TUEB) on 60 patients since April 2008. The patients were 61 to 81 years old (average 71.7 years old), and estimated prostate volumes were 25 cm3 to 80.43 cm3 (average 51.1 cm3). The weight of prostate removed was 8 g to 56 g (average 27.4 g) during the operations which lasted between 40 min to 200 min (average 117.5 min). The International Prostate Symptom Score (IPSS), quality of life index (QOL) maximum flow rate (Q max) and average flow rate (Qave) were recorded before operation, and at 1 and at 3 months after operation. The results indicated a high safety with TUEB compared to TUR-P even for beginners. In conclusion, TUEB may become the most common approach in the treatment of BPH.

[Initial results of holmium laser enucleation of prostate for benign prostate hypertrophy patients].

We have performed holmium laser enucleation of prostate (HoLEP) in 14 cases since February 2005. The patient's age ranged from 62 to 84 years old (average: 75). The preoperative results of International Prostate Sympton Score (IPSS), quality of life index, maximum urinary flow rate and residual urine volume were compared with those 3 months after surgery. The mean operation time, the mean estimated prostate volume and the mean enucleated prostate volume were 143 min, 50 cm3 and 35 g, retrospectively. All cases showed improvement in each parameter, and all but one case recovered continence in 3 months after surgery. A periurethral abscess had developed in the patient, suffering from incontinence. We concluded that HoLEP is an effective treatment. The relatively higher incidence of urinary incontinence in HoLEP remains to be resolved in the future.