The Triassic-Jurassic (Tr-J) boundary marks a major extinction event, which (~200 Ma)resulted in global extinctions of fauna and flora both in the marine and terrestrial realms. There prevail great challenges in ...The Triassic-Jurassic (Tr-J) boundary marks a major extinction event, which (~200 Ma)resulted in global extinctions of fauna and flora both in the marine and terrestrial realms. There prevail great challenges in determining the exact location of the terrestrial Tr-J boundary, because of endemism of taxa and the scarcity of fossils in terrestrial settings leading to difficulties in linking marine and terrestrial sedimentary successions. Investigation based on palynology and bivalves has been carried out over a 1113 m thick section, which is subdivided into 132 beds, along the Haojiagou valley on the southern margin of the Junggar Basin of the northern Xinjiang, northwestern China. The terrestrial Lower Jurassic is conformably resting on the Upper Triassic strata. The Upper Triassic covers the Huangshanjie Formation overlaid by the Haojiagou Formation, while the Lower Jurassic comprises the Badaowan Formation followed by the Sangonghe Formation. Fifty six pollen and spore taxa and one algal taxon were identified from the sediments. Based on the key-species and abundance of spores and pollen, three zones were erected: the Late Triassic (Rhaetian) Aratrisporites-Alisporites Assemblage, the Early Jurassic (Hettangian) Perinopollenites-Pinuspollenites Assemblage, and the Sinemurian Perinopollenites-Cycadopites Assemblage. The Tr-J boundary is placed between bed 44and 45 coincident with the boundary between the Haojiagou and Badaowan formations. Beds with Ferganoconcha (?), Unio-Ferganoconcha and Waagenoperna-Yananoconcha bivalve assemblages are recognized. The Ferganoconcha (?) bed is limited to the upper Haojiagou Formation,Unio- Ferganoconcha and Waagenoperna- Yananoconcha assemblages are present in the middle and upper members of the Badaowan Formation. The sedimentary succession is interpreted as terrestrial with two mainly lake deposit intervals within Haojiagou and Badaowan formations, yielding fresh water algae and bivalves. However, the presence of brackish water algae Tasmanites and the marine-littoral facies bivalve Waagenoperna from the Badaowan Formation indicate that the Junggar Basin was influenced by sea water caused by transgressions from the northern Tethys, during the Sinemurian.展开更多
Worldwide,as the population age,osteoporosis is becoming increasingly common,and osteoporotic fractures have a significant economic burden.Postmenopausal women are the most susceptible to developing osteoporosis and t...Worldwide,as the population age,osteoporosis is becoming increasingly common,and osteoporotic fractures have a significant economic burden.Postmenopausal women are the most susceptible to developing osteoporosis and the most critical time to prevent it is during the perimenopausal and early menopausal years.In this regard,we hypothesize rational combination of acupuncture and Traditional Chinese Medicine(TCM)in the form of herbal extract could prevent osteoporosis in women.Estrogen deficiency during menopause causes low-level inflammation that stimulates the formation of osteoclasts,the boneresorbing cells,and simultaneously inhibits the viability and function of osteoblasts,the bone-forming cells.The most potent inflammatory cytokine in skeletal homeostasis is the receptor activator of nuclear factor kappa B ligand(RANKL)that stimulates osteoclast function.Conversely,the canonical Wnt pathway is essential for osteoblastogenesis and bone formation,and estrogen deficiency leads to diminished functioning of this pathway.TCM and acupuncture could target the RANKL and the Wnt pathway in favorable ways to prevent the accelerated bone loss experienced during the early menopausal stage and promote the gain in bone mass in postmenopausal women.In this review,we propose a rational combination of specific TCM and acupuncture targeting those signaling molecules/pathways by the drugs that are in clinical use for the treatment of postmenopausal osteoporosis.Our rational approach revealed that Danshen(Radix Salviae Miltiorrhizae)could exert a synergistic effect with acupuncture.We then propose a translational path for developing the putative combination in women with postmenopausal osteoporosis to curtail the risk of osteoporotic fractures.展开更多
Photocatalysis has emerged as a promising alternative for converting and utilizing CO_(2).Polymeric carbon nitride(PCN),typically synthesized through the one-step thermal polycondensation of nitrogen-rich precursors,h...Photocatalysis has emerged as a promising alternative for converting and utilizing CO_(2).Polymeric carbon nitride(PCN),typically synthesized through the one-step thermal polycondensation of nitrogen-rich precursors,has shown considerable promise due to its adjustable band structure and inherent safety.Over the past five years,significant literature in this field has identified five primary methods for modifying PCN:morphology modulation,element doping,defect induction,co-catalyst loading,and heterojunction construction.A detailed discussion on how each modification method influences light absorption,charge separation,and surface reaction efficiencies in photocatalysis is provided.Based on these findings,several future directions for the development of PCN-based materials are proposed,such as designing tailored PCN structures for specific photocatalytic reactions and using theoretical calculations to verify and correct results from current characterization methods.Despite the challenges associated with the large-scale synthesis of PCN materials with controllable structures and satisfactory performance,this work offers valuable insights for advancing photocatalytic PCN-based systems for large-scale solar fuel production.展开更多
Objective Reef reservoirs have recently been receiving more and more attention due to their important role in petroleum exploration.Large-scale reefs have been previously discovered in the Paleozoic strata of western ...Objective Reef reservoirs have recently been receiving more and more attention due to their important role in petroleum exploration.Large-scale reefs have been previously discovered in the Paleozoic strata of western China,suchas the Late Permian of the Sichuan Basin,Late Ordovician of the Ordos Basin,and Late Ordovician of the Tarim Basin,which are all important hydrocarbon reservoirs in these areas.展开更多
基金supported by Special Basic Research Program of Ministry of Science and Technology of China (Grant No. 2006FY120300)National Committee of Stratigraphy of China. V. Vajda acknowledges the financial support provided by Swedish Research Council (VR, Grant No. 2007-4509)+1 种基金V. Vajda is a Swedish Royal Academy of Sciences Research Fellow founded through the Knut and Alice Wallenbergs Foundationa contribution to UNESCO-IUGS IGCP Project 506
文摘The Triassic-Jurassic (Tr-J) boundary marks a major extinction event, which (~200 Ma)resulted in global extinctions of fauna and flora both in the marine and terrestrial realms. There prevail great challenges in determining the exact location of the terrestrial Tr-J boundary, because of endemism of taxa and the scarcity of fossils in terrestrial settings leading to difficulties in linking marine and terrestrial sedimentary successions. Investigation based on palynology and bivalves has been carried out over a 1113 m thick section, which is subdivided into 132 beds, along the Haojiagou valley on the southern margin of the Junggar Basin of the northern Xinjiang, northwestern China. The terrestrial Lower Jurassic is conformably resting on the Upper Triassic strata. The Upper Triassic covers the Huangshanjie Formation overlaid by the Haojiagou Formation, while the Lower Jurassic comprises the Badaowan Formation followed by the Sangonghe Formation. Fifty six pollen and spore taxa and one algal taxon were identified from the sediments. Based on the key-species and abundance of spores and pollen, three zones were erected: the Late Triassic (Rhaetian) Aratrisporites-Alisporites Assemblage, the Early Jurassic (Hettangian) Perinopollenites-Pinuspollenites Assemblage, and the Sinemurian Perinopollenites-Cycadopites Assemblage. The Tr-J boundary is placed between bed 44and 45 coincident with the boundary between the Haojiagou and Badaowan formations. Beds with Ferganoconcha (?), Unio-Ferganoconcha and Waagenoperna-Yananoconcha bivalve assemblages are recognized. The Ferganoconcha (?) bed is limited to the upper Haojiagou Formation,Unio- Ferganoconcha and Waagenoperna- Yananoconcha assemblages are present in the middle and upper members of the Badaowan Formation. The sedimentary succession is interpreted as terrestrial with two mainly lake deposit intervals within Haojiagou and Badaowan formations, yielding fresh water algae and bivalves. However, the presence of brackish water algae Tasmanites and the marine-littoral facies bivalve Waagenoperna from the Badaowan Formation indicate that the Junggar Basin was influenced by sea water caused by transgressions from the northern Tethys, during the Sinemurian.
文摘Worldwide,as the population age,osteoporosis is becoming increasingly common,and osteoporotic fractures have a significant economic burden.Postmenopausal women are the most susceptible to developing osteoporosis and the most critical time to prevent it is during the perimenopausal and early menopausal years.In this regard,we hypothesize rational combination of acupuncture and Traditional Chinese Medicine(TCM)in the form of herbal extract could prevent osteoporosis in women.Estrogen deficiency during menopause causes low-level inflammation that stimulates the formation of osteoclasts,the boneresorbing cells,and simultaneously inhibits the viability and function of osteoblasts,the bone-forming cells.The most potent inflammatory cytokine in skeletal homeostasis is the receptor activator of nuclear factor kappa B ligand(RANKL)that stimulates osteoclast function.Conversely,the canonical Wnt pathway is essential for osteoblastogenesis and bone formation,and estrogen deficiency leads to diminished functioning of this pathway.TCM and acupuncture could target the RANKL and the Wnt pathway in favorable ways to prevent the accelerated bone loss experienced during the early menopausal stage and promote the gain in bone mass in postmenopausal women.In this review,we propose a rational combination of specific TCM and acupuncture targeting those signaling molecules/pathways by the drugs that are in clinical use for the treatment of postmenopausal osteoporosis.Our rational approach revealed that Danshen(Radix Salviae Miltiorrhizae)could exert a synergistic effect with acupuncture.We then propose a translational path for developing the putative combination in women with postmenopausal osteoporosis to curtail the risk of osteoporotic fractures.
基金the National Natural Science Foundation of China(22209207)the National Key Research and Development Program of China(2022YFB4002400).
文摘Photocatalysis has emerged as a promising alternative for converting and utilizing CO_(2).Polymeric carbon nitride(PCN),typically synthesized through the one-step thermal polycondensation of nitrogen-rich precursors,has shown considerable promise due to its adjustable band structure and inherent safety.Over the past five years,significant literature in this field has identified five primary methods for modifying PCN:morphology modulation,element doping,defect induction,co-catalyst loading,and heterojunction construction.A detailed discussion on how each modification method influences light absorption,charge separation,and surface reaction efficiencies in photocatalysis is provided.Based on these findings,several future directions for the development of PCN-based materials are proposed,such as designing tailored PCN structures for specific photocatalytic reactions and using theoretical calculations to verify and correct results from current characterization methods.Despite the challenges associated with the large-scale synthesis of PCN materials with controllable structures and satisfactory performance,this work offers valuable insights for advancing photocatalytic PCN-based systems for large-scale solar fuel production.
基金funded by the National Natural Science Foundation of China (grants No.41272159 and 41572099)China Geological Survey (grant No.1212011120964)
文摘Objective Reef reservoirs have recently been receiving more and more attention due to their important role in petroleum exploration.Large-scale reefs have been previously discovered in the Paleozoic strata of western China,suchas the Late Permian of the Sichuan Basin,Late Ordovician of the Ordos Basin,and Late Ordovician of the Tarim Basin,which are all important hydrocarbon reservoirs in these areas.