Outcome of a session of extracorporeal shock wave lithotripsy before endoscopic retrograde cholangiopancreatography for problematic and large common bile duct stones

AIM To compare the efficacy of a session of extracorporeal shock wave lithotripsy(ESWL) before endoscopic retrograde cholangiopancreatography(ERCP) vs ERCP only for problematic and large common bile duct(CBD) stones.METHODS Adult patients with CBD stones for whom initial ERCP was unsuccessful because of the large size of CBD stones were identified. The patients were randomized into two groups,an "ESWL + ERCP group" and an "ERCP-only" group. For ESWL + ERCP cases,ESWL was performed prior to ERCP. Clearance of the CBD,complications related to the ESWL/ERCP procedure,frequency of mechanical lithotripsy use and duration of the ERCP procedure were evaluated in both groups.RESULTS There was no significant difference in baseline characteristics between the two groups. A session of ESWL before ERCP compared with ERCP only resulted in similar outcomes in terms of successful stone removal within the first treatment session(74.2% vs 71.0%,P = 0.135),but a higher clearance rate within the second treatment session(84.4% vs 51.6%,P = 0.018) and total stone clearance(96.0% vs 86.0%,P = 0.029). Moreover,ESWL prior to ERCP not only reduced ERCP procedure time(43 ± 21 min vs 59 ± 28 min,P = 0.034) and the rate of mechanical lithotripsy use(20% vs 30%,P = 0.025),but also raised the clearance rate of extremely large stones(80.0% vs 40.0%,P = 0.016). Post-ERCP complications were similar for the two groups.CONCLUSION Based on the higher rate of successful stone removal and minimal complications,ESWL prior to ERCP appears to be a safe and effective treatment for the endoscopic removal of problematic and large CBD stones.

Predicting gas-bearing distribution using DNN based on multi-component seismic data: Quality evaluation using structural and fracture factors

The tight-fractured gas reservoir of the Upper Triassic Xujiahe Formation in the Western Sichuan Depression has low porosity and permeability. This study presents a DNN-based method for identifying gas-bearing strata in tight sandstone. First, multi-component composite seismic attributes are obtained.The strong nonlinear relationships between multi-component composite attributes and gas-bearing reservoirs can be constrained through a DNN. Therefore, we identify and predict the gas-bearing strata using a DNN. Then, sample data are fed into the DNN for training and testing. After optimized network parameters are determined by the performance curves and empirical formulas, the best deep learning gas-bearing prediction model is determined. The composite seismic attributes can then be fed into the model to extrapolate the hydrocarbon-bearing characteristics from known drilling areas to the entire region for predicting the gas reservoir distribution. Finally, we assess the proposed method in terms of the structure and fracture characteristics and predict favorable exploration areas for identifying gas reservoirs.

Linking anisotropy with Fe_3C distribution in AISI 1045 steel

The anisotropy of the microstructure, thermal expansion behavior, corrosion resistance and magnetic properties of AISI 1045 steel was investigated. The distribution of Fe3C lameUae in the investigation plane parallel to the radial directions of molds was observed to differ from that in the investigation plane perpendicular to the radial directions by transmission electron microscopy. The lattice constants a0 of α-Fe deduced from the XRD patterns of samples prepared using a sand （S）-mold and cut parallel to the radial direction of the mold （S//） and using a metal （M）-mold and cut parallel to the radial direction （M//）, the corrosion resistance measured using an electrochemical work- station, and the magnetic permeability obtained by vibrating sample magnetometry also indicated the existence of anisotropy in the tested samples. The anisotropic change of corrosion potential （Eeorr）, pitting potential （Epit） and magnetic permeability （μ） of the samples was observed to depend on the orientation factorF200 of α-Fe in the measured samples, which is controlled by the distribution of Fe3C lamellae in the eutectoid structure.

二氧化碳的人工生物转化（英文）

CO2是最主要的温室气体,也是重要的碳氧资源.从资源和能源发展战略角度,利用低品阶可再生能驱动CO2转化合成化学品,将为CO2资源化利用和可再生能转化并存储为化学能提供极大的发展空间,具有重大意义.目前,利用可再生能光电催化CO2转化利用的研究方兴未艾,而人工生物转化CO2作为重要的合成化学品新途径也受到越来越多的关注.通过模拟自然界中植物和微生物等的自然光合作用过程,设计和构建出人工光合体系,可使人工生物转化CO2以更加高效的方式转化CO2合成化学品.人工生物转化CO2合成化学品是电催化、光催化和光电催化CO2等过程的重要补充,主要包括微生物电合成、无机-生物杂化光合系统、PSII复合体系和代谢工程等关键技术.微生物电合成(microbial electrosynthesis,MES)是在生物电化学系统中利用特定的微生物作为生物催化剂,以电能作为能量输入,通过生物反应将CO2还原成多碳化合物的最有前途的新兴技术之一.用于MES的细菌和酶具备合成单一产物的功能,对于合成目标产物具有100%的选择性.以太阳能、风能等低品阶可再生电能作为其驱动能量,从而使MES成为一种更绿色和可持续的CO2转换技术.MES中CO2转化为高附加值化学品和生物燃料仍处于初步阶段,有许多技术和经济挑战需要解决,如低能量利用效率和CO2转化率.无机-生物杂化光合体系(photosynthetic biohybrid systems,PBSS)是由细菌或酶固定在无机半导体光催化剂上组成的新型光驱动装置,将高效无机光催化剂与酶催化剂或细胞有机体结合起来,以接近或超过自然光合作用或单独化学催化的效率选择性地固定CO2.PBSS可在温和条件下以成本效益高的方式高选择性获得目标产物,并且具有合成大量长链碳分子的能力.该装置也可以理解为是MES反应器以太阳能为动力,或对MES电极进行改造,使其能够直接捕获光能,从而有效地成为一种比天然光合作用具有更高太阳能效率的人工光合作用装置.PBSS目前还处于发展的初级阶段,虽然可以获得更高的太阳能转换效率(10%?20%),但进行实际应用仍有不少困难.其中主要的挑战在于选择可兼容的光采集系统和高效的生物固碳元件,以及生物和非生物组分的无缝集成,即要克服跨生物和非生物界面上的电荷转移屏障.PSII复合体系是最近提出来的一种由天然光合系统二(photosynthetic system II,PSII)和人工光催化剂组成的,或用PSII对MES电极进行修饰,辅助MES对CO2还原的人工光化学体系.与PBSS相比,PSII复合体系的生物酶是PSII,可以再现PSII的生物特征如优秀的光采集能力,PSII可以高效捕获可见太阳光光谱所有波长的能量,并且有效地利用该能量驱动水分解产氢,这也是无机光催化剂不具有的优势.研究人员对利用PSII组装在电极上的光伏转换系统进行了大量研究,并将其应用于CO2光电化学合成,目前已取得初步进展.代谢工程(metabolic engineering)是根据细胞代谢网络对细胞代谢途径进行合理设计,并利用分子生物学手段如重组DNA技术有目的地设计和调控生物体中已有的代谢网络和表达调控网络,从而实现更高效的生物化学转化、能量转移以及积累目标产物的应用学科.目前,代谢工程被大量应用于光合生物固碳,进一步优化CO2到生物量或其他有机碳化合物的资源化利用.通过对代谢工程的研究,提高认识、设计和改造细胞代谢CO2的能力,从而获得低能耗、高效率的固碳途径,推动生物固碳工业技术进步.本文总结了近年来基于上述CO2人工生物转化关键技术在合成不同碳数化合物方面所取得的重要研究成果,并对其未来发展趋势进行了展望.

Dopaminergic neurons show increased low-molecular-mass protein 7 activity induced by 6-hydroxydopamine in vitro and in vivo

Background:Abnormal expression of major histocompatibility complex class I(MHC-I)is increased in dopaminergic(DA)neurons in the substantia nigra(SN)in Parkinson’s disease(PD).Low-molecular-mass protein 7(β5i)is a proteolytic subunit of the immunoproteasome that regulates protein degradation and the MHC pathway in immune cells.Methods:In this study,we investigated the role of β5i in DA neurons using a 6-hydroxydopamine(6-OHDA)model in vitro and vivo.Results:We showed that 6-OHDA upregulatedβ5i expression in DA neurons in a concentration-and time-dependent manner.Inhibition and downregulation ofβ5i induced the expression of glucose-regulated protein(Bip)and exacerbated 6-OHDA neurotoxicity in DA neurons.The inhibition of β5i further promoted the activation of Caspase 3-related pathways induced by 6-OHDA.β5i also activated transporter associated with antigen processing 1(TAP1)and promoted MHC-I expression on DA neurons.Conclusion:Taken together,our data suggest that β5i is activated in DA neurons under 6-OHDA treatment and may play a neuroprotective role in PD.