BACKGROUND Endoscopic retrograde cholangiopancreatography(ERCP)is an invasive endoscopic procedure used mainly to treat hepato-pancreato-biliary(HPB)diseases.The need for ERCP has increased with the rising number of H...BACKGROUND Endoscopic retrograde cholangiopancreatography(ERCP)is an invasive endoscopic procedure used mainly to treat hepato-pancreato-biliary(HPB)diseases.The need for ERCP has increased with the rising number of HPB diseases over the past decade.Thus,due to increased demand,ERCP is performed at more centers.Currently,it is performed by general surgeons,gastroenterology and invasive radiology specialists in the United States and Europe as recommended by the British Society of Gastroenterology(BSG).AIM To present the results of ERCP procedures from fourteen surgical centers in Türkiye.METHODS Fourteen surgical centers performing ERCP were included in the present study.The age,gender,ERCP indication,success status,post-ERCP complications,ERCP reports and the files of 66993 patients who underwent ERCP were collected from the participating centers.The results are discussed according to the targets declared by the BSG,which are volume load per annum,proportion of successful cannulation(>85%),bile duct clearance rate(>75%),stenting rate for strictures(>80%)and complications(<6%).RESULTS A total of 66993 ERCP procedures were performed in the centers included in the study up to August 2024.29250(43.6%)of the procedures were performed urgently,especially for suppurative cholangitis,biliary tract injuries,etc.The remaining 37743(56.4%)cases were performed electively.50.2%of the patients were female and 49.8%were male.The average ages were 56.5 years for women and 55.9 years for men.General anesthesia was used in 84.1%of the patients while sedation was used in 15.9%.The indications were bile duct stone(78.7%),pancreatic tumor(3.9%),papillary tumor(3.3%),cholangiocarcinoma(2.6%),Oddi sphincter dysfunction(2.4%),bile leakage after cholecystectomy(2%),bile leakage after hydatid cyst surgery(1.9%),biliary stricture(1.7%),and other diseases(3.1%).Hyperamylasemia and post-ERCP pancreatitis were the most common complications as observed in 8.1%of the patients.They were usually self-limited and responded to supportive measures.The frequency of the other complications was also consistent with the literature.CONCLUSION There is a huge shortage of ERCP endoscopists worldwide due to insufficient ERCP training and centers especially in developing and underdeveloped countries.As patients requiring ERCP usually present to surgical practitioners,the incorporation of surgeons into this training program is an effective and reliable solution.The BSG recommends the incorporation of surgeons and radiologists in addition to gastroenterology specialists.This study is the first to present the results of ERCP procedures from fourteen surgical centers throughout Türkiye.The results suggest that the surgical centers included were able to achieve the targets set by the BSG.This study demonstrated that the surgical ERCP units in the present work have reached satisfactory results and provided a reliable and successful ERCP service.There are currently no issues regarding the validity and appropriateness of the surgeons performing ERCP.Therefore,ERCP training should be encouraged in surgeons and more surgical ERCP centers should be provided.展开更多
Electrorheological （ER） properties of polyaniline （PAni）, pumice and polyaniline/pumice composites （PAPC） were investigated. Polyaniline and PAni/pumice composite were prepared by oxidative polymerization. PAni/...Electrorheological （ER） properties of polyaniline （PAni）, pumice and polyaniline/pumice composites （PAPC） were investigated. Polyaniline and PAni/pumice composite were prepared by oxidative polymerization. PAni/pumice particlesbased ER suspensions were prepared in silicone oil （SO）, and their ER behavior was investigated as a function of shear rate, electric field strength, concentration and temperature. Sedimentation stabilities of suspensions were determined. It has been found that ER activity of all the suspensions increases with increasing electric field strength, concentration and decreasing shear rate. It has shown that the suspensions have a typical shear thinning non-Newtonian viscoelastic behavior. Yield stress of composite suspensions increased linearly with increasing applied electric field strength and with concentrations of the particles. The effect of high temperature on ER activity of purrfice/silicone oil systems was also investigated.展开更多
The effects of intermediate mechanical deformation （IMD） and bending processing on Bi-2223 tapes were studied. Bi-2223 tapes were manufactured by powder-in-tube process with an IMD. Normal rolling （NR）, pressing ...The effects of intermediate mechanical deformation （IMD） and bending processing on Bi-2223 tapes were studied. Bi-2223 tapes were manufactured by powder-in-tube process with an IMD. Normal rolling （NR）, pressing （P） and sandwich rolling （SR） with different reduction rate were used in the IMD. And there were an optimum reduction rate existing for the three MID techniques, at which critical current reached maximum. Critical current densities Jc of Bi-2223 crystals were measured with an applied magnetic field B respectively parallel to ab face and c axis. Relations of Jc dependences of reduction rate and superconducting materials density D were respectively studied and showed a Gaussian distribution law. Maximum pinning force density Fmax and irreversible magnetic field Birr were introduced to describe the effects of mechanical processing. Analysis of experimental results showed that Jcs Fmax and Birr were linear dependence on D. Obviously, increasing D was a vital way to enhance Jc Bending experiments were performed for SR tapes sheathed by Ag and Ag/Sb and Ag/Mg alloy, respectively. Silver alloy sheathed tapes showed better bending properties than pure silver sheathed one. Therefore, silver alloy sheathed, optimum reduction rate of IMD, and increasing D for Bi-2223 tapes＇ applications were important technical strategies to enhance their mechanical, electrical, and magnetic properties.展开更多
The growth mechanisms of high temperature Yttrium- and Bismuth-based-superconductors were investigated at nanoscale. We started with studying the growth relationships among the three phases of Bi-2201, Bi-2212, and Bi...The growth mechanisms of high temperature Yttrium- and Bismuth-based-superconductors were investigated at nanoscale. We started with studying the growth relationships among the three phases of Bi-2201, Bi-2212, and Bi-2233, and then extended to another growth mechanism of Bi-2223 and the growth of yttrium-based high-temperature nanosuperconductors （nano-YBCO）. A time dependence of growth experiment was performed. In this experiment, the Bi-based superconductors grew within different sintering periods, and its three phases were determined by X-ray diffraction. And then, a time dependence of growth model was suggested to explain the experimental facts. With this model, governing equations were derived to quantitatively describe the growth and decomposition mechanisms during sintering period. The results calculated from the derived equations were well in agreement with the experimental data. We also suggested an alternative growth mechanism for the Bi-2223 phase, which was supported by an observation of transmission electron microscopy （TEM）. The nano-YBCO also grew, and their orthorhombic crystal structures were determined by the TEM. The superconducting properties of Bi-2223 were investigated by the measurements of ac magnetic susceptibility. It is expected that the derived equations will fit the alternative experimental growth mechanism of the Bi-2223 phase and the nano-YBCO growth mechanism, too.展开更多
The optical transmittance properties of single-hole arrays and three-hole chain(vertical)arrays with different geometrical parameters were numerically investigated.It was shown that on increasing the vertical distanc...The optical transmittance properties of single-hole arrays and three-hole chain(vertical)arrays with different geometrical parameters were numerically investigated.It was shown that on increasing the vertical distance between the holes in the hole chain array,the FWHM of the(1,0)resonance mode was decreased and minimum FWHM of 29 nm was obtained for a vertical gap of 48 nm between each side hole.A 1.5–2.0 times larger transmittance enhancement was observed by varying the incident light polarization from the y axis to the x axis.Furthermore,it was found that the optical transmittance of the hole chain array in the case of linearly x-axis polarized incident electromagnetic(EM)field was∼6 times larger than that linearly y-axis polarized incident EM field.展开更多
文摘BACKGROUND Endoscopic retrograde cholangiopancreatography(ERCP)is an invasive endoscopic procedure used mainly to treat hepato-pancreato-biliary(HPB)diseases.The need for ERCP has increased with the rising number of HPB diseases over the past decade.Thus,due to increased demand,ERCP is performed at more centers.Currently,it is performed by general surgeons,gastroenterology and invasive radiology specialists in the United States and Europe as recommended by the British Society of Gastroenterology(BSG).AIM To present the results of ERCP procedures from fourteen surgical centers in Türkiye.METHODS Fourteen surgical centers performing ERCP were included in the present study.The age,gender,ERCP indication,success status,post-ERCP complications,ERCP reports and the files of 66993 patients who underwent ERCP were collected from the participating centers.The results are discussed according to the targets declared by the BSG,which are volume load per annum,proportion of successful cannulation(>85%),bile duct clearance rate(>75%),stenting rate for strictures(>80%)and complications(<6%).RESULTS A total of 66993 ERCP procedures were performed in the centers included in the study up to August 2024.29250(43.6%)of the procedures were performed urgently,especially for suppurative cholangitis,biliary tract injuries,etc.The remaining 37743(56.4%)cases were performed electively.50.2%of the patients were female and 49.8%were male.The average ages were 56.5 years for women and 55.9 years for men.General anesthesia was used in 84.1%of the patients while sedation was used in 15.9%.The indications were bile duct stone(78.7%),pancreatic tumor(3.9%),papillary tumor(3.3%),cholangiocarcinoma(2.6%),Oddi sphincter dysfunction(2.4%),bile leakage after cholecystectomy(2%),bile leakage after hydatid cyst surgery(1.9%),biliary stricture(1.7%),and other diseases(3.1%).Hyperamylasemia and post-ERCP pancreatitis were the most common complications as observed in 8.1%of the patients.They were usually self-limited and responded to supportive measures.The frequency of the other complications was also consistent with the literature.CONCLUSION There is a huge shortage of ERCP endoscopists worldwide due to insufficient ERCP training and centers especially in developing and underdeveloped countries.As patients requiring ERCP usually present to surgical practitioners,the incorporation of surgeons into this training program is an effective and reliable solution.The BSG recommends the incorporation of surgeons and radiologists in addition to gastroenterology specialists.This study is the first to present the results of ERCP procedures from fourteen surgical centers throughout Türkiye.The results suggest that the surgical centers included were able to achieve the targets set by the BSG.This study demonstrated that the surgical ERCP units in the present work have reached satisfactory results and provided a reliable and successful ERCP service.There are currently no issues regarding the validity and appropriateness of the surgeons performing ERCP.Therefore,ERCP training should be encouraged in surgeons and more surgical ERCP centers should be provided.
基金This work was financially supported by the TUBITAK (Turkish Scientific and Technical Research Foundation)Süleyman Demirel University (Nos. TBAG-AY-344, SDU BAP 03-m-714)
文摘Electrorheological （ER） properties of polyaniline （PAni）, pumice and polyaniline/pumice composites （PAPC） were investigated. Polyaniline and PAni/pumice composite were prepared by oxidative polymerization. PAni/pumice particlesbased ER suspensions were prepared in silicone oil （SO）, and their ER behavior was investigated as a function of shear rate, electric field strength, concentration and temperature. Sedimentation stabilities of suspensions were determined. It has been found that ER activity of all the suspensions increases with increasing electric field strength, concentration and decreasing shear rate. It has shown that the suspensions have a typical shear thinning non-Newtonian viscoelastic behavior. Yield stress of composite suspensions increased linearly with increasing applied electric field strength and with concentrations of the particles. The effect of high temperature on ER activity of purrfice/silicone oil systems was also investigated.
文摘The effects of intermediate mechanical deformation （IMD） and bending processing on Bi-2223 tapes were studied. Bi-2223 tapes were manufactured by powder-in-tube process with an IMD. Normal rolling （NR）, pressing （P） and sandwich rolling （SR） with different reduction rate were used in the IMD. And there were an optimum reduction rate existing for the three MID techniques, at which critical current reached maximum. Critical current densities Jc of Bi-2223 crystals were measured with an applied magnetic field B respectively parallel to ab face and c axis. Relations of Jc dependences of reduction rate and superconducting materials density D were respectively studied and showed a Gaussian distribution law. Maximum pinning force density Fmax and irreversible magnetic field Birr were introduced to describe the effects of mechanical processing. Analysis of experimental results showed that Jcs Fmax and Birr were linear dependence on D. Obviously, increasing D was a vital way to enhance Jc Bending experiments were performed for SR tapes sheathed by Ag and Ag/Sb and Ag/Mg alloy, respectively. Silver alloy sheathed tapes showed better bending properties than pure silver sheathed one. Therefore, silver alloy sheathed, optimum reduction rate of IMD, and increasing D for Bi-2223 tapes＇ applications were important technical strategies to enhance their mechanical, electrical, and magnetic properties.
文摘The growth mechanisms of high temperature Yttrium- and Bismuth-based-superconductors were investigated at nanoscale. We started with studying the growth relationships among the three phases of Bi-2201, Bi-2212, and Bi-2233, and then extended to another growth mechanism of Bi-2223 and the growth of yttrium-based high-temperature nanosuperconductors （nano-YBCO）. A time dependence of growth experiment was performed. In this experiment, the Bi-based superconductors grew within different sintering periods, and its three phases were determined by X-ray diffraction. And then, a time dependence of growth model was suggested to explain the experimental facts. With this model, governing equations were derived to quantitatively describe the growth and decomposition mechanisms during sintering period. The results calculated from the derived equations were well in agreement with the experimental data. We also suggested an alternative growth mechanism for the Bi-2223 phase, which was supported by an observation of transmission electron microscopy （TEM）. The nano-YBCO also grew, and their orthorhombic crystal structures were determined by the TEM. The superconducting properties of Bi-2223 were investigated by the measurements of ac magnetic susceptibility. It is expected that the derived equations will fit the alternative experimental growth mechanism of the Bi-2223 phase and the nano-YBCO growth mechanism, too.
文摘The optical transmittance properties of single-hole arrays and three-hole chain(vertical)arrays with different geometrical parameters were numerically investigated.It was shown that on increasing the vertical distance between the holes in the hole chain array,the FWHM of the(1,0)resonance mode was decreased and minimum FWHM of 29 nm was obtained for a vertical gap of 48 nm between each side hole.A 1.5–2.0 times larger transmittance enhancement was observed by varying the incident light polarization from the y axis to the x axis.Furthermore,it was found that the optical transmittance of the hole chain array in the case of linearly x-axis polarized incident electromagnetic(EM)field was∼6 times larger than that linearly y-axis polarized incident EM field.
