Origins of the Ediacaran Doushantuo High-Grade Primary Phosphorites at Kaiyang, Guizhou Province, China.

The Ediacaran Doushantuo phosphate deposit in Kaiyang, Guizhou Province, China, contains thick phosphate ores. Most of the ores are reconstituted phosphorite, and there have been few studies of the primary phosphorites, which has led to controversy regarding the origins and nature of mineralization of these phosphate-rich deposits. We identified high-grade primary phosphorites in the Kaiyang area and undertook a stratigraphic, petrological, sedimentological, geochemical, and isotopic study of these rocks. Moving up-section, the Longshui phosphate ore deposit comprises granular, micritic, stromatolitic, honeycomb, and sandy phosphorites. The first four types of phosphorite contain abundant biological structures, such as spherical, lobe-like, and amorphous forms. These are mainly fossils of benthic multicellular red algae, along with other types of algae. These fossils comprise >70% of the phosphorites, indicating that these are protist phosphorites. The ores are massive, unstratified, and contain numerous layered cavity structures, indicating that the ore bed was originally a reef. The phosphorites have P2O5 contents of 38.6-40.2 wt %, with an average of 38.9 wt %. The Al2O3 + TiO2 values are 0.02-0.44 wt %. The δ18O values of the samples vary from 13.76 to 16.57‰, with an average of 14.60‰, and δ13C values range from -15.789 to -8.697‰, with an average of -13.133‰. The samples exhibit rare-earth element patterns that are enriched with middle rare-earth elements and have strongly negative Ce anomalies. The geochemical features show that the reef was deposited in clear and oxidized waters. The discovery of this high-grade protist phosphorite shows that the involvement of algae was key to the formation of the Kaiyang phosphate-rich deposit.

[Clinical application of blood purification (artificial liver) in treatment of acute liver failure in children].

OBJECTIVE: To investigate the clinical application, indication, timing and prognosis of blood purification (artificial liver, BP) in treatment of acute liver failure in children. METHOD: Artificial liver was used to treat 30 cases of pediatric acute liver failure (PALF), who were hospitalized in pediatric intensive care unit of Bayi Children's Hospital Affiliated to Beijing Military Command General Hospital, during March 2010 to July 2013. Simple plasma exchange (PE) mode was used for PALF without complications, while PE combined with continuous veno-venous hemodiafiltration (CVVHDF) mode was used for PALF with cerebral edema and/or hepatorenal syndrome and/or serious abnormality of electrolyte and acid-base balance. RESULT: Sixteen cases survived and restored hepatic function, with a survival rate of 53.3%. Single PE therapy could significantly decrease total bilirubin (TBIL) from (293.96 ± 214.52) µmol/L to (155.64 ± 140.97) µmol/L (P = 0.033), increase prothrombin time activity (PTA) from (34.50 ± 18.34) % to (60.50 ± 33.97) % (P = 0.013), while it did not significantly influence ammonia from (156.43 ± 67.23) µmol/L to (124.03 ± 62.58) µmol/L (P = 0.156) and alanine transarninase (ALT) from (752.53 ± 1 291.84) U/L to (132.00 ± 98.57) U/L (P = 0.066). PE + CVVHDF therapy could significantly ameliorate TBIL from (326.90 ± 233.85) µmol/L to (157.53 ± 125.31) µmol/L (P = 0.033), ALT from (1 476.64 ± 1 728.18) U/L to (169.38 ± 207.18) U/L (P = 0.019), ammonia from (215.83 ± 83.92) µmol/L to (141.25 ± 63.09) µmol/L (P = 0.022) and PTA from (36.68 ± 23.13)% to (71.75 ± 50.50) % (P = 0.044). Prothrombin time (PT) from (29.71 ± 17.75)s to (16.27 ± 6.38)s (P = 0.008) , ALT from (1 574.11 ± 1 775.96) U/L to (145.81 ± 113.89 ) U/L (P = 0.003) , TBIL from (233.16 ± 219.70) µmol/L to (75.19 ± 86.07) µmol/L (P = 0.012) , ammonia from (182.75 ± 90.07) µmol/L to (101.81 ± 37.14) µmol/L (P = 0.002) and PTA from (38.38 ± 20.39)% to (83.13 ± 41.68)% (P = 0.001) in survived cases significantly ameliorated after BP therapy. TBIL from (394.04 ± 192.80) µmol/L to (249.34 ± 113.97) µmol/L (P = 0.023) in died cases declined significantly after BP therapy, while alteration of PT, ALT, ammonia , and PTA had no statistical significance (P > 0.10) after BP therapy. CONCLUSION: PE + CVVHDF therapy could significantly ameliorate not only TBIL and PTA but also ammonia and ALT compared with single PE therapy. The decline of only an index like TBIL or ALT after BP therapy could not improve the prognosis. The inconsistency between serum bilirubin and ALT levels was an important factor that suggested poor prognosis of ALF, and it might increase survival rate to use BP therapy before that inconsistency emerged.

[Argon plasma coagulation combined CO2 freezing through the flexible bronchoscope for treatment of airway granulation proliferation in children].

OBJECTIVE: To explore the safety and the efficacy of bronchoscopic argon plasma coagulation (APC) combined with CO2 freezing for the treatment of airway granulation hyperplasia after pediatric airway stenting. METHOD: From April 2010 to December 2012, APC combined CO2 cryotherapy was performed for granulation tissue hyperplasia in 8 children after airway stenting, their clinical data, complications and postoperative outcomes and follow-up data were analyzed. RESULT: Five of the 8 cases were male and 3 female, when stenting their age was 2 to 17 months, the average age was (8.63 ± 5.50) months. Granulation tissue hyperplasia appears in the range of bracket covering, common to both ends of the stent. The time from stentinging to find hyperplasia of granulation tissue was 20 days to 19 months. As a result, in 30%-100% of children airway narrowing was found. We applied APC treatment when the bronchoscopy found hyperplasia lesions, then we used CO2 cryotherapy, i.e., freezing was persisted for 1 min twice and more, then the probe was moved until the APC burning area was entirely frozen, dyspnea in children were significantly improved and two cases of atelectasis patients' lung were completely re-expanded. Eight patients had varying degrees of postoperative low to moderate fever, three cases had a small amount of active bleeding after APC treatment, hemostasis was achieved after topical application of endoscopic injection of epinephrine or reptilase bleeding and freezing, no complications occurred with CO2 cryotherapy. According to the efficacy criteria in this article, the result was significantly effective in 6 cases, effective in 1 case, and partially effective in 1 case. CONCLUSION: APC combined with CO2 cryotherapy may be one of the optional methods that rapidly eliminates granulation tissue and remove the airway obstruction, so it can be used in treatment of pediatric airway' benign lesions.