Mechanical Expansion of Steel Tubing as a Solution to Leaky Wellbores

Wellbore cement, a procedural component of wellbore completion operations, primarily provides zonal isolation and mechanical support of the metal pipe (casing), and protects metal components from corrosive fluids. These are essential for uncompromised wellbore integrity. Cements can undergo multiple forms of failure, such as debonding at the cement/rock and cement/metal interfaces, fracturing, and defects within the cement matrix. Failures and defects within the cement will ultimately lead to fluid migration, resulting in inter-zonal fluid migration and premature well abandonment. Currently, there are over 1.8 million operating wells worldwide and over one third of these wells have leak related problems defined as Sustained Casing Pressure (SCP)¹. The focus of this research was to develop an experimental setup at bench-scale to explore the effect of mechanical manipulation of wellbore casing-cement composite samples as a potential technology for the remediation of gas leaks. The experimental methodology utilized in this study enabled formation of an impermeable seal at the pipe/cement interface in a simulated wellbore system. Successful nitrogen gas flow-through measurements demonstrated that an existing microannulus was sealed at laboratory experimental conditions and fluid flow prevented by mechanical manipulation of the metal/cement composite sample. Furthermore, this methodology can be applied not only for the remediation of leaky wellbores, but also in plugging and abandonment procedures as well as wellbore completions technology, and potentially preventing negative impacts of wellbores on subsurface and surface environments.     

右美托咪定对下肢手术患者止血带诱发肢体缺血-再灌注损伤的影响

目的:探讨右美托咪定对下肢手术患者因止血带诱发肢体缺血-再灌注损伤的影响。方法:选取2015年1月-2016年5月我院行下肢手术治疗的患者90例,按照数字随机法分为观察组及对照组,每组各45例。两组均给予蛛网膜下腔阻滞联合硬膜外麻醉,观察组在穿刺成功15 min内静脉输注1μg/kg的右美托咪定,维持剂量0.5μg/kg·h直至手术结束,对照组患者则给予同等剂量的生理盐水。对比两组止血带前(T0)、止血带充气30 min(T1)、止血带充气1 h(T2)、止血带释放后30 min(T3)、止血带释放后1 h(T4)时的超氧化物歧化酶(SOD)、丙二醛(MDA)、肿瘤坏死因子-α(TNF-α)、白介素-6(IL-6)、平均动脉压(MAP)、心率(HR)水平以及不良反应发生情况。结果:T3、T4时点观察组SOD水平显著高于对照组,MDA水平显著低于对照组(P0.05)。T1、T2、T3、T4时点观察组TNF-α水平显著低于对照组,T4时点IL-6水平也显著低于对照组(P0.05)。T1、T2时点观察组MAP、HR水平均显著低于对照组(P0.05)。观察组术中止血带疼痛、高血压发生率均显著低于对照组(P0.05)。结论:右美托咪定可显著抑制下肢手术患者止血带诱发氧化应激反应以及炎症反应,进而降低肢体缺血-再灌注损伤,具有较好的安全性。     

损伤控制性手术在肝胆外科治疗中的临床应用价值

目的:损伤控制性手术(Damage Control Operation,DCO)是针对严重创伤患者进行阶段性修复的外科策略,本文通过观察DCO在肝胆外科治疗中的效果,探讨其临床应用价值,为肝胆外科手术治疗提供参考。方法:选取2012年2月-2013年3月我院收治的90例重症肝胆外伤患者的临床资料进行回顾性分析。将所选病例随机分为对照组和DCO组,每组45例。其中对照组实施常规手术治疗,DCO组实施损伤控制性手术进行治疗。对比两组患者的手术时间,术中出血量、死亡率、术后感染及并发症等。结果:DCO组手术时间为(62.59±8.61)min,术中出血量为(306.48±23.54)m L,死亡率为20%,术后感染率为8.89%,并发症的发生率为11.11%;对照组术时间为(90.35±7.86)min,术中出血量为(600.32±34.21)m L,死亡率为53.33%,术后感染率为24.44%,并发症的发生率为35.56%;DCO组患者的各项指标均优于对照组,差异显著且具有统计学意义(P0.05)。结论:在肝胆外科治疗中采用损伤控制性手术具有明显的临床效果,不但缩短了手术时间,减少出血量,降低死亡率,提高手术成功率,而且降低了术后并发症及感染的发生率,值得推广。     

Pelvis of Gargoyleosaurus (Dinosauria: Ankylosauria) and the Origin and Evolution of the Ankylosaur Pelvis

Discovery of a pelvis attributed to the Late Jurassic armor-plated dinosaur Gargoyleosaurus sheds new light on the origin of the peculiar non-vertical, broad, flaring pelvis of ankylosaurs. It further substantiates separation of the two ankylosaurs from the Morrison Formation of the western United States, Gargoyleosaurus and Mymoorapelta. Although horizontally oriented and lacking the medial curve of the preacetabular process seen in Mymoorapelta, the new ilium shows little of the lateral flaring seen in the pelvis of Cretaceous ankylosaurs. Comparison with the basal thyreophoran Scelidosaurus demonstrates that the ilium in ankylosaurs did not develop entirely by lateral rotation as is commonly believed. Rather, the preacetabular process rotated medially and ventrally and the postacetabular process rotated in opposition, i.e., lateral and ventrally. Thus, the dorsal surfaces of the preacetabular and postacetabular processes are not homologous. In contrast, a series of juvenile Stegosaurus ilia show that the postacetabular process rotated dorsally ontogenetically. Thus, the pelvis of the two major types of Thyreophora most likely developed independently. Examination of other ornithischians show that a non-vertical ilium had developed independently in several different lineages, including ceratopsids, pachycephalosaurs, and iguanodonts. Therefore, a separate origin for the non-vertical ilium in stegosaurs and ankylosaurs does have precedent.     

Personality as a Predictor of Weight Loss Maintenance after Surgery for Morbid Obesity

Objective: Personality characteristics are assumed to underlie health behaviors and, thus, a variety of health outcomes. Our aim was to examine prospectively whether personality traits predict short‐ and long‐term weight loss after laparoscopic adjustable gastric banding. Research Methods and Procedures: Of patients undergoing laparoscopic adjustable gastric banding, 168 (143 women, 25 men, 18 to 58 years old, mean 37 years, preoperative BMI 45.9 ± 5.6 kg/m²) completed the Dutch Personality Questionnaire on average 1.5 years before the operation. The relationship between preoperative personality and short‐ and long‐term postoperative weight loss was determined using multilevel regression analysis. Results: The average weight loss of patients progressively increased to 10 BMI points until 18 months after surgery and stabilized thereafter. A lower baseline BMI, being a man, and a higher educational level were associated with a lower weight loss. None of the personality variables was associated with weight outcome at short‐term follow‐up. Six of seven personality variables did not predict long‐term weight outcome. Egoism was associated with less weight loss in the long‐term postoperative period. The effect sizes of the significant predictions were small. Discussion: None of the personality variables predicted short‐term weight outcome, and only one variable showed a small and unexpected association with long‐term weight outcome that needs confirmation. This suggests that personality assessment as intake psychological screening is of little use for the prediction of a poor or successful weight outcome after bariatric surgery.     

Postoperative Copeptin as a Biomarker for Development of Diabetes Insipidus Following Hypothalamic-Pituitary Surgery

ObjectiveCopeptin is a surrogate marker of arginine vasopressin release with better stability and simplicity of measurement. Postoperative copeptin levels may guide clinicians in stratifying patients who need close monitoring of fluid balance. The objective is to determine whether copeptin is a predictive marker of postoperative diabetes insipidus (DI).MethodsThis is a prospective diagnostic study. Patients who underwent neurosurgical intervention of the sellar-suprasellar regions were recruited. Serum copeptin levels were measured before and after surgery, within 24 hours. Logistic regression analysis and diagnostic performance measures were calculated to determine the relationship between postoperative copeptin levels and DI.ResultsOf 82 patients, 26 (31.7%) developed postoperative DI, with 7 patients (8.5%) having permanent DI. The samples for copeptin measurement were taken at 13 ± 2.1 hours postoperatively. From the receiver operating characteristic analysis, low postoperative copeptin levels (<2.5 pmol/L) demonstrated an acceptable ability to predict DI (area under the curve, 0.72; 95% CI, 0.60-0.84). Discriminative power was stronger in the permanent DI group (area under the curve, 0.82; 95% CI, 0.64-1.00). Postoperative copeptin levels <2.5 pmol/L were associated with DI (specificity > 91%). However, postoperative copeptin levels >20 pmol/L were rarely associated with DI, with a negative predictive value of 100%.ConclusionsIn patients undergoing sellar-suprasellar interventions, low postoperative copeptin levels within the first postoperative day predict postoperative DI, whereas high levels exclude it. Copeptin measurement should be applied in the clinical practice of postoperative care in patients following hypothalamic-pituitary surgery. This study may expand the potential use of copeptin, including in the Asian population.     

Roentgen Examination of Soft Tissues of the Pelvis

With meticulous preparation of the patient and with careful technique, the soft tissues of the pelvis are identifiable in most cases. Search should be made for the traces of abnormal pelvic structures on plain-film studies. Once the normal is recognized, any variations are easily identified. The fundamental differences between various radiologic densities—air, fat, fluid, muscle, calcium, bone and metal—should be observed. Special procedures can be used to enhance the contrasts after adequate evaluation of the simplest and, on many occasions, the invaluable, plain-film study of the soft tissues of the pelvis.     

损伤控制性手术在野战条件下腹部严重创伤治疗中的应用价值

目的:损伤控制性手术(Damage Control Operation,DCO)是针对严重创伤患者进行阶段性修复的外科策略,本文通过观察DCO在野战条件下严重腹部创伤治疗中的效果,探讨其应用价值,为野战外科手术提供参考。方法:对2012年2月-2013年3月我院收治的90例重症肝胆外伤患者的临床资料进行回顾性分析。将所选病例随机分为对照组和DCO组,每组45例。其中对照组实施常规手术治疗,DCO组实施损伤控制性手术进行治疗。对比两组患者的手术时间,术中出血量、死亡率、术后感染及并发症等。结果:DOC组手术时间为(62.59±8.61)min,术中出血量为(306.48±23.54)mL,死亡率为20%,术后感染率为8.89%,并发症的发生率为11.11%;对照组术时间为(90.35±7.86)min,术中出血量为(600.32±34.21)mL,死亡率为53.33%,术后感染率为24.44%,并发症的发生率为35.56%;DCO组患者的各项指标均优于对照组,差异显著且具有统计学意义(P0.05)。结论:在肝胆外科治疗中采用损伤控制性手术具有明显的临床效果,不但缩短了手术时间,减少出血量,提高手术成功率,而且降低了术后并发症的发生率,值得推广。