| 1 | Primary dolostone related to the Cretaceous lacustrine hydrothermal sedimentation in Qingxi sag, Jiuquan Basin on the northern Tibetan Plateau显示文摘Based on comprehensive studies in petrography,petrofabric analysis and geochemistry,this paper describes a unique and rare laminated micritic ferruginous primary dolostone crystallized and precipitated from the alkaline hot brine under the conditions of the Mesozoic faulted lake basin.The main rock-forming mineral of this dolostone is ferruginous dolomite with a micritic structure.This dolomite mostly exhibits laminae of 0.1–1 mm thick and is often discovered with other minerals,such as albite,analcite,barite and dickite,which have at least two types of interbedded laminae.Petrogeochemistry reveals that this dolostone contains a large number of typomorphic elements of hydrothermal sedimentation,including Sb,Ba,Sr,Mn,and V.In addition,the LREE is in relatively high concentrations and possesses the typical REE distribution pattern with negative Eu anomaly.Oxygen isotope values(δ18OPDB)range from 5.89‰to 14.15‰with an average of 9.69‰.The ratio of87Sr/86Sr is between0.711648 and 0.719546,with an average of 0.714718.These data indicate that the depositional environment is a stable,blocked,anoxic low-lying hot brine pool in the bottom of deep lake controlled by basement faults.The hydrothermal fluid is the alkaline hot brine formed by the combination of the infiltration lake water and mantle-derived magmatic water,consisting of many ions,including Ca2+,Mg2+and Fe2+.Under the driving flow power of magmatic heat,gravity and compaction,the hydrothermal fluid overcame the overburden pressure and hydrostatic pressure of the lake water body,and boiled to explosion,and then the explosion shattered the original laminated micritic ferruginous primary dolostone near the vent and then formed a new type of dolostone called shattered'hydroexplosion breccias'.In the low-lying,unperturbed hot brine pool,far from the vent,the laminated micritic ferruginous primary dolostone was quickly crystallized and chemicals precipitated from the hydrotherm.This study of special rocks contributes to research into the causes of the formation of lacustrine carbonate rocks and dolostone.In particular,it provides new examples and research insights for future studies of the lacustrine dolomite from the similar Mesozoic and Cenozoic basins in China. | WEN HuaGuo ZHENG RongCai QING HaiRuo FAN MingTao LI YanAn GONG BoShi | 2013 | Science China Earth Sciences2013,56,12: | 12 |
| 2 | A modified double-tract reconstruction following laparoscopic proximal gastrectomy for Siewert Ⅱ adenocarcinoma of the esophagogastric junction (with video)显示文摘Objective:The incidence of adenocarcinoma of the esophagogastric junction(AEG)is increasing.For patients with resectable Siewert II AEG,there is still a lack of consensus with regards to which surgical procedure can well balance survival time and quality of life.This study aims to describe a modified double-tract reconstruction(DTR)method following laparoscopic proximal gastrectomy(LPG)and to evaluate the feasibility,safety,and effects of this novel method.Method:This study retrospectively reviewed 29 patients who received modified DTR after LPG for Siewert Ⅱ AEG at a single center between August 2015 and October 2020.Clinicopathological characteristics,surgical outcomes,nutritional status and dietary ability were analyzed.Result:The mean surgical time was 206.4±39.2 min,mean intraoperative blood loss was 175.9±41.4 mL,and median postoperative hospital stay was 11 d(range,9-70 d).The early complication rate was 13.8%(n=4),and the late complication rate was 6.9%(n=2).No reflux esophagitis or reflux symptom was recorded.There were no perioperative deaths within three months post-operatively.At the third follow-up month after surgery,most patients(25/29,86.2%)were experiencing sufficient oral food intake,with a median frequency of 5 meal/d(range,3-6 meal/d).The median total weight loss was 8 kg(range,0-15 kg)and there were no case of post-operative malnutrition.Conclusion:The modified DTR method following LPG represents a novel,safe,and feasible method that provides sufficient nutritional support with few diet-related discomforts.Prospective large-scale randomized trials are now needed to validate the clinical applicability of this method. | Boshi Fan Weian Song Junqiang Liu Shouyin Di Caiying Yue Taiqian Gong | 2021 | Laparoscopic, Endoscopic and Robotic Surgery2021,4,4: | 0 |