There exist differences in the epidemiological characteristics,clinicopathological features,tumor biological characteristics,treatment patterns,and drug selections between gastric cancer patients from the Eastern and ...There exist differences in the epidemiological characteristics,clinicopathological features,tumor biological characteristics,treatment patterns,and drug selections between gastric cancer patients from the Eastern and Western countries.The Chinese Society of Clinical Oncology(CSCO)has organized a panel of senior experts specializing in all sub-specialties of gastric cancer to compile a clinical guideline for the diagnosis and treatment of gastric cancer since 2016 and renews it annually.Taking into account regional differences,giving full consideration to the accessibility of diagnosis and treatment resources,these experts have conducted expert consensus judgment on relevant evidence and made various grades of recommendations for the clinical diagnosis and treatment of gastric cancer to reflect the value of cancer treatment and meeting health economic indexes in China.The 2021 CSCO Clinical Practice Guidelines for Gastric Cancer covers the diagnosis,treatment,follow-up,and screening of gastric cancer.Based on the 2020 version of the CSCO Chinese Gastric Cancer guidelines,this updated guideline integrates the results ofmajor clinical studies from China and overseas for the past year,focused on the inclusion of research data from the Chinese population for more personalized and clinically relevant recommendations.For the comprehensive treatment of non-metastatic gastric cancer,attentions were paid to neoadjuvant treatment.The value of perioperative chemotherapy is gradually becoming clearer and its recommendation level has been updated.For the comprehensive treatment of metastatic gastric cancer,recommendations for immunotherapy were included,and immune checkpoint inhibitors fromthird-line to the first-line of treatment for different patient groups with detailed notes are provided.展开更多
AIM： To investigate the functional, morphological changes of the gut barrier during the restitution process after hemorrhagic shock, and the regional differences of the large intestine and small intestine in response...AIM： To investigate the functional, morphological changes of the gut barrier during the restitution process after hemorrhagic shock, and the regional differences of the large intestine and small intestine in response to ischemia/ reperfusion injury. METHODS： Forty-seven Sprague-Dawley rats with body weight of 250-300 g were divided into two groups： control group （sham shock n = 5） and experimental group （n = 42）. Experimental group was further divided into six groups （n = 7 each） according to different time points after the hemorrhagic shock, including 0^th group, 1^st group, 3^rd group, 6th h group, 12^th group and 24^th group. All the rats were gavaged with 2 mL of suspension of lactulose （L） （100 mg/2 mL） and mannitol （M） （50 mg/each） at the beginning and then an experimental rat model of hemorrhagic shock was set up. The specimens from jejunum, ileum and colon tissues and the blood samples from the portal vein were taken at 0, 1, 3, 6, 12 and 24 h after shock resuscitation, respectively. The morphological changes of the intestinal mucosa, including the histology of intestinal mucosa, the thickness of mucosa, the height of villi, the index of mucosal damage and the numbers of goblet cells, were determined by light microscope and/or electron microscope. The concentrations of the bacterial endotoxin lipopolysaccharides （LPS） from the portal vein blood, which reflected the gut barrier function, were examined by using Limulus test. At the same time point, to evaluate intestinal permeability, all urine was collected and the concentrations of the metabolically inactive markers such as L and M in urine were measured by using GC-9A gas chromatographic instrument.RESULTS： After the hemorrhagic shock, the mucosal epithelial injury was obvious in small intestine even at the 0th h, and it became more serious at the 1^stand the 3^rd h. The tissue restitution was also found after 3 h, though the injury was still serious. Most of the injured mucosal restitution was established after 6 展开更多
Nasopharyngeal carcinoma(NPC)is a malignant epithelial tumor originating in the nasopharynx and has a high incidence in Southeast Asia and North Africa.To develop these comprehensive guidelines for the diagnosis and m...Nasopharyngeal carcinoma(NPC)is a malignant epithelial tumor originating in the nasopharynx and has a high incidence in Southeast Asia and North Africa.To develop these comprehensive guidelines for the diagnosis and management of NPC,the Chinese Society of Clinical Oncology(CSCO)arranged a multi-disciplinary team comprising of experts from all sub-specialties of NPC to write,discuss,and revise the guidelines.Based on the findings of evidencebased medicine in China and abroad,domestic experts have iteratively developed these guidelines to provide proper management of NPC.Overall,the guidelines describe the screening,clinical and pathological diagnosis,staging and risk assessment,therapies,and follow-up of NPC,which aim to improve the management of NPC.展开更多
Background： Patients on hemodialysis have a high-mortality risk. Tiffs study analyzed factors associated with death in patients on maintenance hemodialysis （MHD）. While some studies used baseline data of MHD patien...Background： Patients on hemodialysis have a high-mortality risk. Tiffs study analyzed factors associated with death in patients on maintenance hemodialysis （MHD）. While some studies used baseline data of MHD patients, this study used the most recent data obtained from patients just prior to either a primary endpoint or the end of the study period to iliad the characteristics of patients preceding death.Methods： Participants were selected from 16 blood purification centers in China from January 2012 to December 2014, Patients＇ data were collected retrospectively. Based on survival status, the participants were divided into two groups： survival group and the death group. Logistic regression analysis was performed to determine/＇actors associated with all-cause mortality.展开更多
This paper reports geochemical and Pb-Sr-Nd isotopic compositions of the Indosinian Yangba (215 Ma),Nanyili (225 Ma) and Mopi granitoids from the Bikou block of the northwestern margin of the Yangtze plate. These gran...This paper reports geochemical and Pb-Sr-Nd isotopic compositions of the Indosinian Yangba (215 Ma),Nanyili (225 Ma) and Mopi granitoids from the Bikou block of the northwestern margin of the Yangtze plate. These granitoids are enriched in Al (Al2O3:14.56%―16.48%) and Sr (352 μg/g―1047 μg/g),and depleted in Y (<16 μg/g) and HREE (e.g. Yb<1.61 μg/g),resulting in high Sr/Y (36.3―150) and (La/Yb)N (7.8―36.3) ratios and strongly fractionationed REE patterns. The Indosinian granotoids show initial Sr isotopic ratios (ISr) from 0.70419 to 70752,εNd(t) values from-3.1 to -8.5,and initial Pb isotopic ratios 206Pb/204Pb=17.891-18.250,207Pb/204Pb=15.494-15.575,and 208Pb/204Pb=37.788-38.335. Their geochemi-cal signatures indicate that the granitoids are adakitic. However,they are distinct from some adakites,generated by partial melting of subducted oceanic slab and/or underplated basaltic lower crust,be-cause they have high K (K2O: 1.49%―3.84%) and evolved Nd isotopic compositions,with older Nd iso-topic model ages (TDM=1.06―1.83 Ga). Geochemical and Sr-Nd isotopic compositions suggest that the magmas of the Insoninian adakitic rocks in the Bikou block were derived from partial melting of thick-ened basaltic lower crust. Combined with regional analyses,a lithospheric delamination model after collision between the North China and South China plates can account for the Indosinian adakitic magma generation. On the other hand,based on the Pb-Sr-Nd isotopic probing to the magma sources of the adakitic rocks,it is suggested that there is an unexposed continent-type basement under the exposed Bikou Group volcanic rocks. This can constrain on the Bikou Group volcanic rocks not to be MORB-or OIB-type.展开更多
Zircons were separated from granitoids, gneisses, and sedimentary rocks of the Chinese Altai. Those with igneous characteristics yielded U-Pb ages of 280-2800 Ma, recording a long history of magmatic activity in the r...Zircons were separated from granitoids, gneisses, and sedimentary rocks of the Chinese Altai. Those with igneous characteristics yielded U-Pb ages of 280-2800 Ma, recording a long history of magmatic activity in the region. Zircon Hf isotopic compositions show an abrupt change at ~420 Ma, indicating that prior to that time the magmas came from both ancient and juvenile sources, whereas younger magmas were derived mainly from juvenile material. This may imply that the lithosphere was signifi- cantly modified in composition by a rapid addition of melt from the mantle. We suggest that this dramatic change was due to the onset of ridge subduction, which can account not only for the formation of voluminous granitoids, mafic rocks with complex compositions, and the association of adakite + high-Mg andesite + boninite + Nb-enriched basalt, but also for the coeval high-T, low-P metamorphism.展开更多
The Large sky Area Multi-Object Fiber Spectroscopic Telescope（LAMOST） general survey is a spectroscopic survey that will eventually cover approximately half of the celestial sphere and collect 10 million spectra of ...The Large sky Area Multi-Object Fiber Spectroscopic Telescope（LAMOST） general survey is a spectroscopic survey that will eventually cover approximately half of the celestial sphere and collect 10 million spectra of stars, galaxies and QSOs. Objects in both the pilot survey and the first year regular survey are included in the LAMOST DR1. The pilot survey started in October 2011 and ended in June 2012, and the data have been released to the public as the LAMOST Pilot Data Release in August 2012. The regular survey started in September 2012, and completed its first year of operation in June 2013. The LAMOST DR1 includes a total of 1202 plates containing 2 955 336 spectra, of which 1 790 879 spectra have observed signalto-noise ratio（SNR） ≥ 10. All data with SNR ≥ 2 are formally released as LAMOST DR1 under the LAMOST data policy. This data release contains a total of 2 204 696 spectra, of which 1 944 329 are stellar spectra, 12 082 are galaxy spectra and 5017 are quasars. The DR1 not only includes spectra, but also three stellar catalogs with measured parameters： late A,FGK-type stars with high quality spectra（1 061 918 entries）, A-type stars（100 073 entries）, and M-type stars（121 522 entries）. This paper introduces the survey design, the observational and instrumental limitations, data reduction and analysis, and some caveats. A description of the FITS structure of spectral files and parameter catalogs is also provided.展开更多
Background： Antiphospholipid syndrome （APS）-related immune factors are considered as an important cause of recurrent spontaneous abortion （RSA）. Anticoagulant and anti-inflammatory treatments are believed to effe...Background： Antiphospholipid syndrome （APS）-related immune factors are considered as an important cause of recurrent spontaneous abortion （RSA）. Anticoagulant and anti-inflammatory treatments are believed to effectively improve adverse pregnancy outcomes by affecting the abnormal autoimmune response of the maternal-fetal interface. The aim of this study was to observe the clinical characteristics and treatment outcomes of anticoagulant regimens and anti-inflammatory plus anticoagulation regimens for APS-related RSA. Methods： APS-related RSA cases from September 2011 to September 2016 at Peking University Third Hospital were retrospectively analyzed. The patients were assigned to study group （anti-inflammation plus anticoagulation） and control group （simple anticoagulation）, The incidence of repeat abortion, the incidence of placental dysfunction, the gestational weeks of pregnancy, and the mean weight of the fetus were observed. Results： The pregnancy and neonatal outcome indicators of the repeat pregnancy loss rate （ 11. 11% vs. 22.70%）, placental dysfunction-related diseases （6.35% vs. 15.60%）, the mean birth weight of infants born after 24 weeks gestation （3152.4 ± 844.67 g vs. 2765.76 ± 816.40 g）, full-ternl delivery weight （3456.28 ±419.79 g vs. 3076.18±518.79 g）, the proportions of low birth weight infants （ 12.70% vs. 21.98%）, and small for gestational age （6.35% vs. 14.18%） differed significantly between the study and control groups （all P 〈 0.05）. The incidence of preterm delivery, term delivery, and stillbirth was not significantly different between the two groups, and there was no significant difference between the study and control groups in gestational age at birth （37.6 ± 3.3 weeks vs. 36.9 ± 3.2 weeks： P 〉 0.05）. Conclusion： The anti-inflammatory and anticoagulation regimen is more effective than the simple anticoagulation regimen in the treatlnent of APS recurrent abortion.展开更多
Lithium–sulfur(Li–S)batteries have extremely high theoretical energy density that make them as promising systems toward vast practical applications.Expediting redox kinetics of sulfur species is a decisive task to b...Lithium–sulfur(Li–S)batteries have extremely high theoretical energy density that make them as promising systems toward vast practical applications.Expediting redox kinetics of sulfur species is a decisive task to break the kinetic limitation of insulating lithium sulfide/disulfide precipitation/dissolution.Herein,we proposed a porphyrinderived atomic electrocatalyst to exert atomic-efficient electrocatalytic effects on polysulfide intermediates.Quantifying electrocatalytic efficiency of liquid/solid conversion through a potentiostatic intermittent titration technique measurement presents a kinetic understanding of specific phase evolutions imparted by the atomic electrocatalyst.Benefiting from atomically dispersed“lithiophilic”and“sulfiphilic”sites on conductive substrates,the finely designed atomic electrocatalyst endows Li–S cells with remarkable cycling stablity(cyclic decay rate of 0.10%in 300 cycles),excellent rate capability(1035 mAh g−1 at 2 C),and impressive areal capacity(10.9 mAh cm−2 at a sulfur loading of 11.3 mg cm−2).The present work expands atomic electrocatalysts to the Li–S chemistry,deepens kinetic understanding of sulfur species evolution,and encourages application of emerging electrocatalysis in other multielectron/multiphase reaction energy systems.展开更多
The sequence of the rice genome holds fundamental information for its biology, including physiology, genetics, development, and evolution, as well as information on many beneficial phenotypes of economic significance....The sequence of the rice genome holds fundamental information for its biology, including physiology, genetics, development, and evolution, as well as information on many beneficial phenotypes of economic significance. Using a "whole genome shotgun" approach, we have pro-duced a draft rice genome sequence of Oryza sativa ssp. in-dica, the major crop rice subspecies in China and many other regions of Asia. The draft genome sequence is constructed from over 4.3 million successful sequencing traces with an accumulative total length of 2214.9 Mb. The initial assembly of the non-redundant sequences reached 409.76 Mb in length, based on 3.30 million successful sequencing traces with a total length of 1797.4 Mb from an indica variant cultivar 93-11, giving an estimated coverage of 95.29% of the rice genome with an average base accuracy of higher than 99%. The coverage of the draft sequence, the randomness of the sequence distribution, and the consistency of BIG-ASSEM-BLER, a custom-designed software package展开更多
文摘There exist differences in the epidemiological characteristics,clinicopathological features,tumor biological characteristics,treatment patterns,and drug selections between gastric cancer patients from the Eastern and Western countries.The Chinese Society of Clinical Oncology(CSCO)has organized a panel of senior experts specializing in all sub-specialties of gastric cancer to compile a clinical guideline for the diagnosis and treatment of gastric cancer since 2016 and renews it annually.Taking into account regional differences,giving full consideration to the accessibility of diagnosis and treatment resources,these experts have conducted expert consensus judgment on relevant evidence and made various grades of recommendations for the clinical diagnosis and treatment of gastric cancer to reflect the value of cancer treatment and meeting health economic indexes in China.The 2021 CSCO Clinical Practice Guidelines for Gastric Cancer covers the diagnosis,treatment,follow-up,and screening of gastric cancer.Based on the 2020 version of the CSCO Chinese Gastric Cancer guidelines,this updated guideline integrates the results ofmajor clinical studies from China and overseas for the past year,focused on the inclusion of research data from the Chinese population for more personalized and clinically relevant recommendations.For the comprehensive treatment of non-metastatic gastric cancer,attentions were paid to neoadjuvant treatment.The value of perioperative chemotherapy is gradually becoming clearer and its recommendation level has been updated.For the comprehensive treatment of metastatic gastric cancer,recommendations for immunotherapy were included,and immune checkpoint inhibitors fromthird-line to the first-line of treatment for different patient groups with detailed notes are provided.
基金Supported by the Grants from the Health Research Foundation (A2003189) and the Science Research Project (2004B30601001) of Guangdong Province, China
文摘AIM： To investigate the functional, morphological changes of the gut barrier during the restitution process after hemorrhagic shock, and the regional differences of the large intestine and small intestine in response to ischemia/ reperfusion injury. METHODS： Forty-seven Sprague-Dawley rats with body weight of 250-300 g were divided into two groups： control group （sham shock n = 5） and experimental group （n = 42）. Experimental group was further divided into six groups （n = 7 each） according to different time points after the hemorrhagic shock, including 0^th group, 1^st group, 3^rd group, 6th h group, 12^th group and 24^th group. All the rats were gavaged with 2 mL of suspension of lactulose （L） （100 mg/2 mL） and mannitol （M） （50 mg/each） at the beginning and then an experimental rat model of hemorrhagic shock was set up. The specimens from jejunum, ileum and colon tissues and the blood samples from the portal vein were taken at 0, 1, 3, 6, 12 and 24 h after shock resuscitation, respectively. The morphological changes of the intestinal mucosa, including the histology of intestinal mucosa, the thickness of mucosa, the height of villi, the index of mucosal damage and the numbers of goblet cells, were determined by light microscope and/or electron microscope. The concentrations of the bacterial endotoxin lipopolysaccharides （LPS） from the portal vein blood, which reflected the gut barrier function, were examined by using Limulus test. At the same time point, to evaluate intestinal permeability, all urine was collected and the concentrations of the metabolically inactive markers such as L and M in urine were measured by using GC-9A gas chromatographic instrument.RESULTS： After the hemorrhagic shock, the mucosal epithelial injury was obvious in small intestine even at the 0th h, and it became more serious at the 1^stand the 3^rd h. The tissue restitution was also found after 3 h, though the injury was still serious. Most of the injured mucosal restitution was established after 6
文摘Nasopharyngeal carcinoma(NPC)is a malignant epithelial tumor originating in the nasopharynx and has a high incidence in Southeast Asia and North Africa.To develop these comprehensive guidelines for the diagnosis and management of NPC,the Chinese Society of Clinical Oncology(CSCO)arranged a multi-disciplinary team comprising of experts from all sub-specialties of NPC to write,discuss,and revise the guidelines.Based on the findings of evidencebased medicine in China and abroad,domestic experts have iteratively developed these guidelines to provide proper management of NPC.Overall,the guidelines describe the screening,clinical and pathological diagnosis,staging and risk assessment,therapies,and follow-up of NPC,which aim to improve the management of NPC.
文摘Background： Patients on hemodialysis have a high-mortality risk. Tiffs study analyzed factors associated with death in patients on maintenance hemodialysis （MHD）. While some studies used baseline data of MHD patients, this study used the most recent data obtained from patients just prior to either a primary endpoint or the end of the study period to iliad the characteristics of patients preceding death.Methods： Participants were selected from 16 blood purification centers in China from January 2012 to December 2014, Patients＇ data were collected retrospectively. Based on survival status, the participants were divided into two groups： survival group and the death group. Logistic regression analysis was performed to determine/＇actors associated with all-cause mortality.
基金Supported by the National Natural Science Foundation of China (Grant Nos. 40234052 and 40521001)the Program for Changjiang Scholars and Innovative Research Team in University (Grant No. IRT0441)
文摘This paper reports geochemical and Pb-Sr-Nd isotopic compositions of the Indosinian Yangba (215 Ma),Nanyili (225 Ma) and Mopi granitoids from the Bikou block of the northwestern margin of the Yangtze plate. These granitoids are enriched in Al (Al2O3:14.56%―16.48%) and Sr (352 μg/g―1047 μg/g),and depleted in Y (<16 μg/g) and HREE (e.g. Yb<1.61 μg/g),resulting in high Sr/Y (36.3―150) and (La/Yb)N (7.8―36.3) ratios and strongly fractionationed REE patterns. The Indosinian granotoids show initial Sr isotopic ratios (ISr) from 0.70419 to 70752,εNd(t) values from-3.1 to -8.5,and initial Pb isotopic ratios 206Pb/204Pb=17.891-18.250,207Pb/204Pb=15.494-15.575,and 208Pb/204Pb=37.788-38.335. Their geochemi-cal signatures indicate that the granitoids are adakitic. However,they are distinct from some adakites,generated by partial melting of subducted oceanic slab and/or underplated basaltic lower crust,be-cause they have high K (K2O: 1.49%―3.84%) and evolved Nd isotopic compositions,with older Nd iso-topic model ages (TDM=1.06―1.83 Ga). Geochemical and Sr-Nd isotopic compositions suggest that the magmas of the Insoninian adakitic rocks in the Bikou block were derived from partial melting of thick-ened basaltic lower crust. Combined with regional analyses,a lithospheric delamination model after collision between the North China and South China plates can account for the Indosinian adakitic magma generation. On the other hand,based on the Pb-Sr-Nd isotopic probing to the magma sources of the adakitic rocks,it is suggested that there is an unexposed continent-type basement under the exposed Bikou Group volcanic rocks. This can constrain on the Bikou Group volcanic rocks not to be MORB-or OIB-type.
基金Supported by National Basic Research Program of China (Grant No. 2007CB411308)Hong Kong RGC Grants (Grant Nos. HKU704307P and 704004P)+1 种基金National Natural Science Foundation of China (Grant Nos. 40772130, 40803009)CAS/SAFEA International Partnership Program for Creative Research Teams
文摘Zircons were separated from granitoids, gneisses, and sedimentary rocks of the Chinese Altai. Those with igneous characteristics yielded U-Pb ages of 280-2800 Ma, recording a long history of magmatic activity in the region. Zircon Hf isotopic compositions show an abrupt change at ~420 Ma, indicating that prior to that time the magmas came from both ancient and juvenile sources, whereas younger magmas were derived mainly from juvenile material. This may imply that the lithosphere was signifi- cantly modified in composition by a rapid addition of melt from the mantle. We suggest that this dramatic change was due to the onset of ridge subduction, which can account not only for the formation of voluminous granitoids, mafic rocks with complex compositions, and the association of adakite + high-Mg andesite + boninite + Nb-enriched basalt, but also for the coeval high-T, low-P metamorphism.
基金funded by the National Basic Research Program of China (973 Program, 2014CB845700)the National Natural Science Foundation of China (Grant Nos. 11390371)Funding for the project has been provided by the National Development and Reform Commission
文摘The Large sky Area Multi-Object Fiber Spectroscopic Telescope（LAMOST） general survey is a spectroscopic survey that will eventually cover approximately half of the celestial sphere and collect 10 million spectra of stars, galaxies and QSOs. Objects in both the pilot survey and the first year regular survey are included in the LAMOST DR1. The pilot survey started in October 2011 and ended in June 2012, and the data have been released to the public as the LAMOST Pilot Data Release in August 2012. The regular survey started in September 2012, and completed its first year of operation in June 2013. The LAMOST DR1 includes a total of 1202 plates containing 2 955 336 spectra, of which 1 790 879 spectra have observed signalto-noise ratio（SNR） ≥ 10. All data with SNR ≥ 2 are formally released as LAMOST DR1 under the LAMOST data policy. This data release contains a total of 2 204 696 spectra, of which 1 944 329 are stellar spectra, 12 082 are galaxy spectra and 5017 are quasars. The DR1 not only includes spectra, but also three stellar catalogs with measured parameters： late A,FGK-type stars with high quality spectra（1 061 918 entries）, A-type stars（100 073 entries）, and M-type stars（121 522 entries）. This paper introduces the survey design, the observational and instrumental limitations, data reduction and analysis, and some caveats. A description of the FITS structure of spectral files and parameter catalogs is also provided.
文摘Background： Antiphospholipid syndrome （APS）-related immune factors are considered as an important cause of recurrent spontaneous abortion （RSA）. Anticoagulant and anti-inflammatory treatments are believed to effectively improve adverse pregnancy outcomes by affecting the abnormal autoimmune response of the maternal-fetal interface. The aim of this study was to observe the clinical characteristics and treatment outcomes of anticoagulant regimens and anti-inflammatory plus anticoagulation regimens for APS-related RSA. Methods： APS-related RSA cases from September 2011 to September 2016 at Peking University Third Hospital were retrospectively analyzed. The patients were assigned to study group （anti-inflammation plus anticoagulation） and control group （simple anticoagulation）, The incidence of repeat abortion, the incidence of placental dysfunction, the gestational weeks of pregnancy, and the mean weight of the fetus were observed. Results： The pregnancy and neonatal outcome indicators of the repeat pregnancy loss rate （ 11. 11% vs. 22.70%）, placental dysfunction-related diseases （6.35% vs. 15.60%）, the mean birth weight of infants born after 24 weeks gestation （3152.4 ± 844.67 g vs. 2765.76 ± 816.40 g）, full-ternl delivery weight （3456.28 ±419.79 g vs. 3076.18±518.79 g）, the proportions of low birth weight infants （ 12.70% vs. 21.98%）, and small for gestational age （6.35% vs. 14.18%） differed significantly between the study and control groups （all P 〈 0.05）. The incidence of preterm delivery, term delivery, and stillbirth was not significantly different between the two groups, and there was no significant difference between the study and control groups in gestational age at birth （37.6 ± 3.3 weeks vs. 36.9 ± 3.2 weeks： P 〉 0.05）. Conclusion： The anti-inflammatory and anticoagulation regimen is more effective than the simple anticoagulation regimen in the treatlnent of APS recurrent abortion.
基金This work was supported by the National Key Research and Development Program(2016YFA0202500)National Natural Science Foundation of China(21776019,21808124,and U1801257)We thank Jin Xie and Meng Zhao for their helpful discussion.
文摘Lithium–sulfur(Li–S)batteries have extremely high theoretical energy density that make them as promising systems toward vast practical applications.Expediting redox kinetics of sulfur species is a decisive task to break the kinetic limitation of insulating lithium sulfide/disulfide precipitation/dissolution.Herein,we proposed a porphyrinderived atomic electrocatalyst to exert atomic-efficient electrocatalytic effects on polysulfide intermediates.Quantifying electrocatalytic efficiency of liquid/solid conversion through a potentiostatic intermittent titration technique measurement presents a kinetic understanding of specific phase evolutions imparted by the atomic electrocatalyst.Benefiting from atomically dispersed“lithiophilic”and“sulfiphilic”sites on conductive substrates,the finely designed atomic electrocatalyst endows Li–S cells with remarkable cycling stablity(cyclic decay rate of 0.10%in 300 cycles),excellent rate capability(1035 mAh g−1 at 2 C),and impressive areal capacity(10.9 mAh cm−2 at a sulfur loading of 11.3 mg cm−2).The present work expands atomic electrocatalysts to the Li–S chemistry,deepens kinetic understanding of sulfur species evolution,and encourages application of emerging electrocatalysis in other multielectron/multiphase reaction energy systems.
基金This work was sponsored by the Chinese Academy of Sciences, the Commission for Economy Planning, the Ministry of Science and Technology, the National Natural Science Foundation of China, Beijing Municipal Government, Zhejiang Provincial Government, and H
文摘The sequence of the rice genome holds fundamental information for its biology, including physiology, genetics, development, and evolution, as well as information on many beneficial phenotypes of economic significance. Using a "whole genome shotgun" approach, we have pro-duced a draft rice genome sequence of Oryza sativa ssp. in-dica, the major crop rice subspecies in China and many other regions of Asia. The draft genome sequence is constructed from over 4.3 million successful sequencing traces with an accumulative total length of 2214.9 Mb. The initial assembly of the non-redundant sequences reached 409.76 Mb in length, based on 3.30 million successful sequencing traces with a total length of 1797.4 Mb from an indica variant cultivar 93-11, giving an estimated coverage of 95.29% of the rice genome with an average base accuracy of higher than 99%. The coverage of the draft sequence, the randomness of the sequence distribution, and the consistency of BIG-ASSEM-BLER, a custom-designed software package
