[Hydrochemical Characteristics and the Dissolved Inorganic Carbon Flux in Liuzhou Section of Liujiang Basin].

An important aspect of the current global change research is using river chemical composition to reveal the chemical weathering process and its effect of carbon sink. In this study, water samples were collected and analyzed 2 ~3 times per month from January to December in 2013. The hydrochemistry belonged to HCO3-Ca type. Ca+ and HCO3- were the main cation and anion, which reflected that the hydrochemical characteristics of river were mainly affected by the dissolution of carbonate rock. The concentration of main ions varied with the seasons, which reflected that the crest value occurred in winter, followed by those in autumn and spring, and the lowest value was observed in summer. Due to the interaction of effect of dilution and effect of C2, the seasonal variation of Ca2+ and HCO3- showed that the highest value was in autumn and the lowest value was in summer. The seasonal variation law of other ions should be attributed to the effect of dilution or agricultural activities or combined action of them. Both carbonic acid and sulfuric acid took part in the chemical weathering of carbonate rocks as evidenced by stoichiometric analysis. Besides, the δ34S of sulfate ion of the river waters (δ34S: from 7. 65 per thousand to 8. 55 per thousand) showed that SO2- was originated mainly from oxidation of sulfide minerals in ore deposits and acid rain. Chemical mass balance method was applied to estimate the proportion of HCO- coming from carbonate weathering by sulfuric acid. The result was 28. 26% . On this basis, the total carbon flux of carbon ( by CO2 calculation) in Liuzhou section calculated month by month was about 8. 95 x 10(5) t . a-1. What's more, the carbon flux showed a positive correlation with flow, which implied that the discharge of catchment was the main influencing factor of carbon flux rather than the HCO3- concentration.

[Gynecomastia in 38 children: etiology and treatment].

OBJECTIVE: To summarize the etiology and treatment of gynecomastia in male children. METHODS: The clinical data of 38 boys with gynecomastia at ages of 2-14 years were retrospectively studied. RESULTS: In the 38 cases, 17 cases were identified as adolescent breast hyperplasia, 2 cases were relevant to primary disease, 4 cases were caused by ingestion of drugs containing hormone, and 15 cases did not show identifiable causes and were diagnosed as idiopathic gynecomastia. For the 3 children with breast development in B3 stage, oral rupixiao was administered (1.34 g, tid) for one month. For 16 children at ages of over 12 years with breast development in B2 stage and with obvious clinical symptoms, oral rupixiao was administered (1.34 g, tid) for 3-5 days. The other patients did not receive drug treatment. In a one month to one year follow-up, most of the patients recovered well. CONCLUSIONS: The etiology of gynecomastia in male children includes adolescent breast hyperplasia, ingestion of drugs containing hormone and secondary causes. Most gynecomastia can be attributed to physiological reasons. Only a few children with obvious clinical symptoms need drug treatment.