The Global Stratotype Section and Point(GSSP)of the base-Wuchiapingian Stage was formally ratified at the Penglaitan section in South China in 2005.However,the riverside GSSP section at Penglaitan and its auxiliary se...The Global Stratotype Section and Point(GSSP)of the base-Wuchiapingian Stage was formally ratified at the Penglaitan section in South China in 2005.However,the riverside GSSP section at Penglaitan and its auxiliary section at Tieqiao have been permanently flooded since 2020.We herein designate an excavated section at Penglaitan as the new GSSP and the Fengshan section as a new Standard Auxiliary Boundary Stratotype(SABS).In addition,we revised the original definition based on a detailed restudy of the conodont succession from the two sections.We define the GSSP of the base-Wuchiapingian by the First Appearance Datum(FAD)of Clarkina postbitteri within the lineage Jinogondolella granti→Clarkina postbitteri→C.dukouensis.It represents a major evolutionary turnover in conodonts from Jinogondolella to Clarkina and marks the end-Guadalupian extinction event.The U-Pb date of 259.51±0.21 Ma from the uppermost part of the Emeishan basalt is adopted for the GLB age.δ13Ccarb chemostratigraphy at the SABS exhibits several excursions between 3‰and 5‰across the GLB interval.Carbonate 87Sr/86Sr ratio is 0.707244 at the GLB.Remarkably,the SABS contains six normal and six reverse geomagnetic polarity zones in the uppermost Capitanian and three in the lowest Wuchiapingian.展开更多
The Ideale section(IS)at Montalbano Jonico,Italy,has been approved as a Standard Auxiliary Boundary Stratotype(SABS)for the Global boundary Stratotype Section and Point(GSSP)of the Middle Pleistocene Subseries/Subepoc...The Ideale section(IS)at Montalbano Jonico,Italy,has been approved as a Standard Auxiliary Boundary Stratotype(SABS)for the Global boundary Stratotype Section and Point(GSSP)of the Middle Pleistocene Subseries/Subepoch and Chibanian Stage/Age at the Chiba section,Japan.The proposal was submitted to the voting members of the International Commission on Stratigraphy’s Subcommission on Quaternary Stratigraphy(SQS)on May 4,2023,and following discussions was approved on July 8,2023.The 74 m thick IS continuously spans the Marine Isotope Stage(MIS)20–18 interval,and is part of the longer Montalbano Jonico succession(Basilicata,southern Italy in the Mediterranean region)encompassing MIS 37 to early MIS 16.The IS provides a detailed record based on multiple chronologically well constrained marine and terrestrial proxies,which are particularly useful for outlining the paleoclimatic evolution through the Lower–Middle Pleistocene transition.The high-resolution carbon and oxygen isotope stratigraphy outlines glacial–interglacial and stadial–interstadial phases as well as the sub-millennialscale features of Termination IX and the onset of MIS 19c.The sapropel layer equivalent to insolation cycle 74(784 ka)occurs in early MIS 19c.A prominent peak in the 10Be/9Be record at the MIS 19c–19b transition identifies the low geomagnetic dipole moment associated with the Matuyama–Brunhes boundary interval.Two tephra layers(V3 and V4)relevant to boundary interval are 40Ar/39Ar dated.The V4 layer,occurring at the MIS 19c–b transition and in the middle of the 10Be/9Be peak,has an age of 774.1±0.9 ka,corresponding to the age of the Middle Pleistocene GSSP.A high-resolution alkenone sea-surface temperature and several paleobiological records complement the rich chronological and paleoenvironmental dataset from MIS 20 to the inception of MIS 18.The GSSP boundary interval in the IS is represented from 35.50 to 39.50 m,which corresponds to the interval of the highest values of the 10Be/9Be ratio(~776.35–771.87 ka)and includes the V4 tephra layer and the MIS 19c–MIS 19b transition.This SABS extends the correlation potential of the Middle Pleistocene Subseries/Subepoch GSSP interval to the Mediterranean region.展开更多
Background: Sub arachnoid block (SAB) performed by traditional landmark palpation technique can be inaccurate. This problem is exacerbated by altered patient anatomy due to obesity and age-related changes. A pre-proce...Background: Sub arachnoid block (SAB) performed by traditional landmark palpation technique can be inaccurate. This problem is exacerbated by altered patient anatomy due to obesity and age-related changes. A pre-procedural ultrasound scan of the lumbar spine has been shown to be of benefit in guiding lumbar epidural insertion in obstetric patients. Information on the use of real-time ultrasound (RUS) guided SAB, to date, been limited. This study compared RUS guided SAB to traditional landmark guided technique in patients undergoing spinal anesthesia for different surgical procedures. Methods: This was a prospective, single center, comparative observational study conducted in the department of anesthesiology at our center. 560 patients who underwent spinal anesthesia either by landmark based technique or real-time ultrasound-guided methods. The primary outcome was the first attempt success rate of dural puncture when employing the two methods. Results: Baseline characteristics were similar in the two study groups. The first attempt success rate of dural puncture in landmark guided group was 64.3% compared to 72.6% in the ultrasound guided group. This difference was not statistically significant. The procedure performance time was significantly shorter with landmark palpation compared to use of real-time ultrasound guided method. Conclusion: Use of RUS-guided technique does not significantly improve the first attempt success rate of SAB dural puncture during spinal anesthesia compared to the traditional landmark-guided technique.展开更多
基金supported by the National Natural Science Foundation of China(42293280,42272031,42250104,42261144668)Strategic Priority Research Program(B)of the Chinese Academy of Sciences(XDB26000000).
文摘The Global Stratotype Section and Point(GSSP)of the base-Wuchiapingian Stage was formally ratified at the Penglaitan section in South China in 2005.However,the riverside GSSP section at Penglaitan and its auxiliary section at Tieqiao have been permanently flooded since 2020.We herein designate an excavated section at Penglaitan as the new GSSP and the Fengshan section as a new Standard Auxiliary Boundary Stratotype(SABS).In addition,we revised the original definition based on a detailed restudy of the conodont succession from the two sections.We define the GSSP of the base-Wuchiapingian by the First Appearance Datum(FAD)of Clarkina postbitteri within the lineage Jinogondolella granti→Clarkina postbitteri→C.dukouensis.It represents a major evolutionary turnover in conodonts from Jinogondolella to Clarkina and marks the end-Guadalupian extinction event.The U-Pb date of 259.51±0.21 Ma from the uppermost part of the Emeishan basalt is adopted for the GLB age.δ13Ccarb chemostratigraphy at the SABS exhibits several excursions between 3‰and 5‰across the GLB interval.Carbonate 87Sr/86Sr ratio is 0.707244 at the GLB.Remarkably,the SABS contains six normal and six reverse geomagnetic polarity zones in the uppermost Capitanian and three in the lowest Wuchiapingian.
文摘The Ideale section(IS)at Montalbano Jonico,Italy,has been approved as a Standard Auxiliary Boundary Stratotype(SABS)for the Global boundary Stratotype Section and Point(GSSP)of the Middle Pleistocene Subseries/Subepoch and Chibanian Stage/Age at the Chiba section,Japan.The proposal was submitted to the voting members of the International Commission on Stratigraphy’s Subcommission on Quaternary Stratigraphy(SQS)on May 4,2023,and following discussions was approved on July 8,2023.The 74 m thick IS continuously spans the Marine Isotope Stage(MIS)20–18 interval,and is part of the longer Montalbano Jonico succession(Basilicata,southern Italy in the Mediterranean region)encompassing MIS 37 to early MIS 16.The IS provides a detailed record based on multiple chronologically well constrained marine and terrestrial proxies,which are particularly useful for outlining the paleoclimatic evolution through the Lower–Middle Pleistocene transition.The high-resolution carbon and oxygen isotope stratigraphy outlines glacial–interglacial and stadial–interstadial phases as well as the sub-millennialscale features of Termination IX and the onset of MIS 19c.The sapropel layer equivalent to insolation cycle 74(784 ka)occurs in early MIS 19c.A prominent peak in the 10Be/9Be record at the MIS 19c–19b transition identifies the low geomagnetic dipole moment associated with the Matuyama–Brunhes boundary interval.Two tephra layers(V3 and V4)relevant to boundary interval are 40Ar/39Ar dated.The V4 layer,occurring at the MIS 19c–b transition and in the middle of the 10Be/9Be peak,has an age of 774.1±0.9 ka,corresponding to the age of the Middle Pleistocene GSSP.A high-resolution alkenone sea-surface temperature and several paleobiological records complement the rich chronological and paleoenvironmental dataset from MIS 20 to the inception of MIS 18.The GSSP boundary interval in the IS is represented from 35.50 to 39.50 m,which corresponds to the interval of the highest values of the 10Be/9Be ratio(~776.35–771.87 ka)and includes the V4 tephra layer and the MIS 19c–MIS 19b transition.This SABS extends the correlation potential of the Middle Pleistocene Subseries/Subepoch GSSP interval to the Mediterranean region.
文摘Background: Sub arachnoid block (SAB) performed by traditional landmark palpation technique can be inaccurate. This problem is exacerbated by altered patient anatomy due to obesity and age-related changes. A pre-procedural ultrasound scan of the lumbar spine has been shown to be of benefit in guiding lumbar epidural insertion in obstetric patients. Information on the use of real-time ultrasound (RUS) guided SAB, to date, been limited. This study compared RUS guided SAB to traditional landmark guided technique in patients undergoing spinal anesthesia for different surgical procedures. Methods: This was a prospective, single center, comparative observational study conducted in the department of anesthesiology at our center. 560 patients who underwent spinal anesthesia either by landmark based technique or real-time ultrasound-guided methods. The primary outcome was the first attempt success rate of dural puncture when employing the two methods. Results: Baseline characteristics were similar in the two study groups. The first attempt success rate of dural puncture in landmark guided group was 64.3% compared to 72.6% in the ultrasound guided group. This difference was not statistically significant. The procedure performance time was significantly shorter with landmark palpation compared to use of real-time ultrasound guided method. Conclusion: Use of RUS-guided technique does not significantly improve the first attempt success rate of SAB dural puncture during spinal anesthesia compared to the traditional landmark-guided technique.
