A Stable Q Compensated Reverse Time Migration Method Based on Excitation Amplitude Imaging Condition

The stability and efficiency, especially the stability, are generally concerned issues in Q compensated reverse time migration (Q-RTM). The instability occurs because of the exponentially boosted high frequency ambient noise during the forward or backward seismic wavefield propagation. The regularization and low-pass filtering methods are two effective strategies to control the instability of the wave propagation in Q-RTM. However, the regularization parameters are determined experimentally, and the wavefield cannot be recovered accurately. The low-pass filtering method cannot balance the selection of cutoff frequency for varying Q values, and may damage the effective signals, especially when the signal-to-noise ratio (SNR) of the seismic data is low, the Q-RTM will be a highly unstable process. In order to achieve the purpose of stability, the selection of cutoff frequency will be small enough, which can cause great damage to the effective high frequency signals. In this paper, we present a stable Q-RTM algorithm based on the excitation amplitude imaging condition, which can compensate both the amplitude attenuation and phase dispersion. Unlike the existing Q-RTM algorithms enlarging the amplitude, the exponentially attenuated seismic wavefield will be used during both the forward and backward wavefield propagation of Q-RTM. Therefore, the new Q-RTM algorithm is relative stable, even for the low SNR seismic data. In order to show the accuracy and stability of our stable Q-RTM algorithm clearly, an example based on Graben model will be illustrated. Then, a realistic BP gas chimney model further demonstrates that the proposed method enjoys good stability and anti-noise performance compared with the traditional Q-RTM with amplitude amplification. Compare the Q-RTM images of these two models to the reference images obtained by the acoustic RTM with acoustic seismic data, the new Q-RTM results match the reference images quite well. The proposed method is also tested using a field seismic data, the result shows the effectiveness of our proposed method.     

经鼻高流量湿化氧疗在小儿先心病术后的疗效观察

目的探析经鼻高流量湿化氧疗用于小儿先心病术后治疗中的效果以及护理措施。方法2014年9月—2017年10月在郑州儿童医院外科监护室接受手术治疗的先心病患儿中随机抽取130例,根据术后氧疗方法不同分组:对照组患儿术后给予常规面罩吸氧,观察组患儿术后给予经鼻高流量湿化氧疗,2组患儿均给予优质术后护理,对比2组的血气指标、住院时间等。结果2组患者氧疗后24h、48h的血氧饱和度差异无统计学意义,在氧疗后24h的PaCO2水平差异无统计学意义,而在氧疗后24h和48h的氧合指数,观察组明显高于对照组,差异有统计学意义(P<0.05);2组ICU入住时间和总住院时间差异无统计学意义(P>0.05)。结论经鼻高流量湿化氧疗的应用提高先心病患儿术后的舒适度,改善呼吸状况,值得推广。     

Additional bedtime H2‐receptor antagonist for the control of nocturnal gastric acid breakthrough: A Cochrane systematic review

OBJECTIVES: To assess the effectiveness and safety of additional bedtime H₂‐receptor antagonists (H₂RAs) in suppressing nocturnal gastric acid breakthrough (NAB) via a systematic review. METHODS: Eligible trials were identified by searching the Cochrane Central Register of Controlled Trials (CENTRAL) (Cochrane Library Issue 2, 2004), MEDLINE (January 1966–June 2004), EMBASE (January 1980–June 2004) and CINAHL (January 1982–June 2004). Additional hand‐searching was conducted on the proceedings of correlated conferences, eight important Chinese journals and references of all included trials. All randomized controlled trials evaluating H₂RAs for the control of NAB were eligible for inclusion. The systematic review was conducted using methods recommended by The Cochrane Collaboration. RESULTS: Only two randomized crossover studies, comprising 32 participants, met the inclusion criteria. Because the design, dosage and duration of the treatments were different between the studies, it was not possible to conduct meta‐analysis. There were no consistent conclusions found between the two included studies in evaluating H₂RAs for the control of NAB. CONCLUSIONS: No implications for practice at this stage can be concluded. Appropriately designed large‐scale randomized controlled trials with long‐term follow up are needed to determine the effects of additional bedtime H₂RAs in suppressing NAB.     

IL-1Ra和IL-10真核表达质粒载体的构建及其表达检测

目的:构建人IL-1Ra和人IL-10真核表达质粒载体并检测其表达。方法:用双酶切方法切取PCDI-IL-1Ra和PCDI-IL-10质粒中包含人IL-1Ra和人IL-10 CDS全长序列的cD-NA片段,并分别连接到真核表达质粒pcDNA3.1上,然后用壳聚糖转染上述质粒到原代软骨细胞,RT-PCR检测其mRNA水平的表达。结果:成功将人IL-1Ra和IL-10 CDS全长序列的cDNA片段克隆到真核表达载体,mRNA水平检测到目的基因的表达明显提高。结论:真核表达质粒可以用于外源基因的原代软骨细胞导入和表达,为进一步的基因治疗研究提供依据。     

磁共振成像在肝移植术后并发症诊断中的应用

目的探讨磁共振成像在肝移植并发症诊断中的价值。方法回顾分析11例肝移植术后发生并发症者的磁共振检查影像资料。结果11例患者术后出现皮肤和巩膜黄染、发热以及尿黄等症状，丙氨酸转氨酶、天冬氨酸转氨酶、γ-谷氨酰转移酶和胆红素升高．经B型超声波检查不能明确原因，采用磁共振（MRI、MRA和MRCP）检查，明确肝动脉吻合口狭窄1例；肝动脉闭塞2例；下腔静脉吻合口狭窄及血栓形成各1例；胆管吻合口狭窄4例，其中1例伴胆汁瘤形成；肝门水平非吻合口狭窄6例；肝坏死2例；肝包膜下血肿及右肾上腺出血各1例；均显示不等量的右侧胸腔积液、腹腔积液及肝门部水肿。结论磁共振一次检查可显示肝内外的多种结构，能为肝移植术后并发症的诊断提供丰富的肝脏、血管、胆道以及肝外结构的图像信息。     

特需病房护理工作特点及管理对策

特需医疗服务是顺应社会政治、经济、文化和组织形态的发展,伴随医学模式的改变,在医学高度进步的知识经济时代,充分利用医学及相关学科的资源而产生的一种特殊医疗服务形式[1]。特需医疗的特点不是医疗原则和医疗质量的特殊,而是通过改善医疗服务时间、空间、生活设旋、就诊环     

针灸加微波治疗肱骨外上髁炎100例

肱骨外上髁炎,俗称网球肘,属中医筋伤范畴,是常见的肘部筋腱慢性劳损性疾病。多见于从事前臂劳动强度较大的工作人员,如木工、银行点钞员及网球运动员。临床可见肘关节外侧酸痛、病侧手部无力握物、前臂旋转活动受限。中医认为与素体亏损、血不养筋、气滞血瘀有关。2004年5月至今我院理疗康复中心采用“针灸加微波疗法治疗肱骨外上髁炎100例,结果令人满意。现总结如下。1临床资料100例患者均为门诊病例,诊断均符合高等中医院校《中医骨伤科学》肘部筋伤的诊断标准。其中男性30例,女性7例;年龄最大65岁,最小30例,平均年龄45岁;病程最长年,最…     

乙酰半胱氨酸对脓毒症大鼠炎症介质的影响及对肝脏的保护作用

目的探讨乙酰半胱氨酸(NAC)对脓毒症大鼠肝脏损伤的保护作用。方法90只Wistar大鼠随机分为3组,每组30只。即假手术组(A组),脓毒症模型组(B组),NAC治疗组(C组)。A组除不结扎盲肠,不刺穿盲肠外,余操作同B组；B组成功后不做任何处理；C组NAC治疗组,盲肠结扎穿孔后大鼠立即经尾静脉给予NAC 150 mg/kg体重。各组大鼠在术后6、12、24 h分次处死,每次10只,取下腔静脉血检测血清中炎性细胞因子水平,并取肝组织行病理检查。结果血清ALT、AST水平B组、C组二组12 h后明显上升,ALT水平在12 h以后B组显著高于C组[(132．80±12．36)U/L比(87．40±10．22)U/L；(284．60±26．47)U/L比(156．60±13．56)U/L],AST水平24 h B组显著高于C组[(308．60±30．42)U/L比(175．60±17．67)U/L]；B组大鼠血中炎性细胞介质水平显著升高,肿瘤坏死因子(TNF)-α为165．41±20．14,325．36±42．20,578．40±61．70；白细胞介素(IL)-1β为(128．24±17．21),(298．24±32．02),(302．36±46．26)肝功能与形态出现损伤性变化；C组血中炎性介质水平明显降低,TNF-α为(142．25±18．72)、(232．32±30．24)、(342．20±44．55)ng/L；IL-1β(96．41±16．3)、(164．30±26．18)、(201．47±40．56)ng/L肝功能与形态损伤减轻。结论NAC对大鼠脓毒症有治疗作用,其机制可能是通过减少机体炎症介质的释放引起。     

微囊化异种甲状旁腺组织移植的研究

目的探讨微囊化异种甲状旁腺(PTG)组织移植对Wistar大鼠甲状旁腺功能低下的治疗作用及微囊的通透性。方法 40只去甲状旁腺Wistar大鼠随机分为微囊组、非微囊组、空囊组、空白对照组。用海藻酸-钡交联微囊包裹兔甲状旁腺组织,移植至Wistar大鼠肾包囊。移植后每隔2周取血测血钙,移植后第16周取移植物进行透射电镜检查及T淋巴细胞、大鼠IgG抗体的免疫组织化学染色。结果微囊组移植后第4周血清钙由(1．62±0．04)mmol／L恢复至正常水平 (2．2～2．6)mmol／L,9例维持至观察期结束(P<0．01),非微囊组、空囊组及空白对照组血清钙差异无统计学意义(P>0．05)。第16周取出移植物检测显示移植物活性良好,微囊周围可见较多T 淋巴细胞浸润,囊壁及囊内IgG抗体染色阳性。结论海藻酸-钡交联微囊可对甲状旁腺组织起到有效的保护作用,使甲状旁腺组织较长时间存活并发挥正常功能。但海藻酸-钡交联微囊并未减轻受体免疫排斥反应的激活且未有效的免疫隔离IgG抗体。     

可控性回结肠膀胱术10例报告

对１０例膀胱癌患者施行根治性全膀胱切除可控性回肠膀胱术，经随访，除１例术后２年因肿瘤转移至盆腔骨关节及肺部而死上，９例均健在，可控自行导尿，无漏尿及返流现象，结果表明，这种用结肠去管重建，用缩窄的末段回肠做输出道的贮尿囊，可控性能好，容量大，电解质紊乱轻，插管容易，不影响肾功能，并发症少，临床观察效果满意。