Effects of N and P additions on twig traits of wild apple (Malus sieversii) saplings.

BACKGROUND: Wild apple (Malus sieversii) is under second-class national protection in China and one of the lineal ancestors of cultivated apples worldwide. In recent decades, the natural habitation area of wild apple trees has been seriously declining, resulting in a lack of saplings and difficulty in population regeneration. Artificial near-natural breeding is crucial for protecting and restoring wild apple populations, and adding nitrogen (N) and phosphorous (P) is one of the important measures to improve the growth performance of saplings. In this study, field experiments using N (CK, N1, N2, and N3: 0, 10, 20, and 40 g m- 2 yr- 1, respectively), P (CK, P1, P2, and P3: 0, 2, 4, and 8 g m- 2 yr- 1, respectively), N20Px (CK, N2P1, N2P2, and N2P3: N20P2, N20P4 and N20P8 g m- 2 yr- 1, respectively), and NxP4 (CK, N1P2, N2P2, and N3P2: N10P4, N20P4, and N40P4 g m- 2 yr- 1, respectively) treatments (totaling 12 levels, including one CK) were conducted in four consecutive years. The twig traits (including four current-year stem, 10 leaf, and three ratio traits) and comprehensive growth performance of wild apple saplings were analyzed under different nutrient treatments. RESULTS: N addition had a significantly positive effect on stem length, basal diameter, leaf area, and leaf dry mass, whereas P addition had a significantly positive effect on stem length and basal diameter only. The combination of N and P (NxP4 and N20Px) treatments evidently promoted stem growth at moderate concentrations; however, the N20Px treatment showed a markedly negative effect at low concentrations and a positive effect at moderate and high concentrations. The ratio traits (leaf intensity, leaf area ratio, and leaf to stem mass ratio) decreased with the increase in nutrient concentration under each treatment. In the plant trait network, basal diameter, stem mass, and twig mass were tightly connected to other traits after nutrient treatments, indicating that stem traits play an important role in twig growth. The membership function revealed that the greatest comprehensive growth performance of saplings was achieved after N addition alone, followed by that under the NxP4 treatment (except for N40P4). CONCLUSIONS: Consequently, artificial nutrient treatments for four years significantly but differentially altered the growth status of wild apple saplings, and the use of appropriate N fertilizer promoted sapling growth. These results can provide scientific basis for the conservation and management of wild apple populations.

Benign Prostatic Hyperplasia Treatment by Transurethral Enucleation of the Prostate Using a 2-µm Laser.

This study investigates the efficacy of benign prostatic hyperplasia (BPH) treatment by prostate transurethral enucleation using a 2-µm laser. A total of 107 patients with BPH were treated by prostate transurethral enucleation using a RevoLix 2-µm laser surgery system. Bleeding volume, operation time, catheterization time, voiding situation, maximum urinary flow rate, and hospital stay were observed. The mean operation time was 74 min ± 12 min (range 45 to 150 min), the mean follow-up period was 2 to 6 months, the mean catheter time was 5 days, and the mean peak urinary flow rate increased from 6.3 ± 0.6 to 17.5 ± 1.5 mL/s. The International Prostate Symptom Score and quality of life significantly declined (p < 0.01). No significant differences were observed in the hemoglobin and blood electrolytes before and after operation. Prostate transurethral enucleation using a 2-µm laser is safe and efficient for BPH treatment.

[Characteristics and sources of PM10-bound PAHs during haze period in winter-spring of Xiamen].

PM10 samples were collected at Huli (industrial zone) and Dadeng Island in Xiamen from December 2008 to March 2009. Nineteen polycyclic aromatic hydrocarbons (PAHs) during haze and non-haze periods were determined by GC/MS. Combined with the meteorological data, the differences of chemical composition and source of PAHs were compared. During sampling periods, the concentrations of PM10-bound PAHs ranged from 12.93 to 79.27 ng x m(-3) with the average of 42.28 ng x m(-3), which were almost three times higher than those in the winter of 2004. PAHs concentrations were much higher during the haze periods than those in the non-haze periods. Meanwhile, during the haze periods the percentages of lower molecular weight PAHs such as Phe, Fluo and Pyr decreased significantly, on the contrary, individual components of BbF, BkF, BaP, Per, Icdp, BghiP and COR were more abundant. The main sources of PAHs were estimated by the Principal Component Analysis method and the contributions of various pollution sources to PAHs were calculated by the Multiple Linear Regression method. Results showed that the main pollutant sources of PM10-bound PAHs in winter-spring of Xiamen during the haze period were vehicle emission plus natural gas, coal combustion and coke oven, their contribution rates were 62.7%, 28.1% and 9.2%, respectively. During non-haze periods, the main pollutant sources identified were the same and the contribution rates were 48.6%, 36.9% and 14.5%, respectively. In winter-spring of Xiamen, PM10-bound PAHs were more influenced by local emission sources during the haze periods; coal combustion emissions in north China had a big contribution to PAHs during the non-haze periods.

[Effect of surfactant on the volatilization of organochlorine pesticides from still artificial seawater].

The effect of sodium dodecylbenzene sulfonate (SDBS) on the volatilization of 17 organochlorine pesticides (OCPs) from still artificial seawater has been examined. The results show that SDBS at low concentration can retard the volatilization of OCPs compared to "clean" surface. The retarding influence is more pronounced for high level of SDBS than it is for low level of SDBS. A good positive correlation between the gas-seawater partition coefficients and the measured volatilization rates of OCPs is observed. Although the SDBS films present no significant, direct resistance to transfer, the films can absorb more OCPs from the above atmosphere with respect to the "clean" surface and reduce the net volatilization flux from the still artificial seawater. The effect of the film is more pronounced for volatilization of more volatile OCPs than it is for less volatile OCPs.

Effect of midfollicular luteinizing hormone levels on ovarian response and pregnancy outcome in patients undergoing in vitro fertilization in a short-term protocol.

In a retrospective study, levels of LH in the midfollicular phase had a significant impact on ovarian response and pregnancy outcome. High LH levels were associated with reduced implantation and clinical pregnancy rates.