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Although tropical forest soils contributed substantially global soil methane uptake, observations on soil methane fluxes in tropical forests are still sparse, especially in Southeast Asia, leading to large uncertainty in the estimation of global soil methane uptake. Here, we conducted two-year (from Sep, 2016 to Sep, 2018) measurements of soil methane fluxes in a lowland tropical forest site in Hainan island, China. At this tropical forest site, soils were substantial methane sink, and average annual soil methane uptake was estimated at 2.00 kg CH 4 -C ha -1 yr -1 . The seasonality of soil methane uptake showed strong methane uptake in the dry season (-1.00 nmol m -2 s -1 ) and almost neutral or weak soil methane uptake in the wet season (-0.24 nmol m -2 s -1 ). The peak soil methane uptake rate was observed as -1.43 nmol m -2 s -1 in February, 2018, the driest and coolest month during the past 24 months. Soil moisture was the dominant controller of methane fluxes, and could explain 94% seasonal variation of soil methane fluxes. Soil temperature could not enhance the explanation of seasonal variation of soil methane fluxes on the top of soil moisture. A positive relationship between soil methane uptake and soil respiration was also detected, which might indicate co-variation in activities of methanotroph and roots and/or microbes for soil heterotrophic respiration. Our study highlights that tropical forests in this region acted as a methane sink.

To investigate the surgical outcomes of vesiculoscopy on refractory hematospermia and ejaculatory duct obstruction (EDO), the clinical data (including pelvic magnetic resonance imaging (MRI) examinations and the long-term effects of endoscopic treatment) from 305 patients were analyzed. Four main etiologic groups were found on MRI. We found that 62.0% (189/305) of patients showed abnormal signal intensity in MRI investigations in the seminal vesicle (SV) area. Cystic lesions were observed in 36.7% (112/305) of the patients. The third sign was dilatation or enlargement of unilateral or bilateral SV, which were observed in 32.1% (98/305) of the patients. The fourth sign was stone formation in SV or in an adjacent cyst, which was present in 8.5% (26/305) of the patients. The transurethral endoscopy or seminal vesiculoscopy and the related procedures, including fenestration in prostatic utricle (PU), irrigation, lithotripsy, stone removal, biopsy, electroexcision, fulguration, or transurethral resection/incision of the ejaculatory duct (TURED/TUIED), chosen according to the different situations of individual patients were successfully performed in 296 patients. Fenestrations in PU+ seminal vesiculoscopy were performed in 66.6% (197/296) of cases. Seminal vesiculoscopy via the pathological opening in PU was performed in 10.8% (32/296) of cases. TURED/TUIED + seminal vesiculoscopy was performed in 12.8% (38/296) of cases, and seminal vesiculoscopy by the natural orifices of the ejaculatory duct (ED) was performed in 2.4% (7/296) of cases. Electroexcision and fulguration to the abnormal blood vessels or cavernous hemangioma at posterior urethra were performed in 7.4% (22/296) of cases. Two hundred and seventy-one patients were followed up for 6-72 months. The hematospermia of all the patients disappeared within 2-6 weeks, and 93.0% of the patients showed no further hematospermia during follow-up. No obvious postoperative complications were observed. The transurethral seminal vesiculoscopy technique and related procedures are safe and effective approaches for refractory hematospermia and EDO.