Pressure induced insulator to metal transition followed by the appearance of superconductivity has been observed recently in inorganic quantum spin liquid candidate NaYbSe_(2).In this paper,we study the properties of ...Pressure induced insulator to metal transition followed by the appearance of superconductivity has been observed recently in inorganic quantum spin liquid candidate NaYbSe_(2).In this paper,we study the properties of isostructural compound NaYbS_(2)under pressure.It is found that the resistance of Na YbS_(2)single crystal exhibits an insulating state below 82.9 GPa,but with a drop of more than six orders of magnitude at room temperature.Then a minimum of resistance is observed at about 100.1 GPa and it moves to lower temperature with further compression.Finally,a metallic state in the whole temperature range is observed at about 130.3 GPa accompanied by a non-Fermi liquid behavior below 100 K.The insulator to metal transition,non-monotonic resistance feature and non-Fermi liquid behavior of NaYbS_(2)under pressure are similar to those of NaYbSe_(2),suggesting that these phenomena might be the universal properties in NaLnCh_(2)(Ln=rare earth,Ch=O,S,Se)system.展开更多
Situated in the Salawusu River Valley, southeast of China's Mu Us Desert, the MGS2 (Milanggouwan section) portion of the Milanggouwan stratigraphic section records 5.5 sedimentary cycles consisting of alternations ...Situated in the Salawusu River Valley, southeast of China's Mu Us Desert, the MGS2 (Milanggouwan section) portion of the Milanggouwan stratigraphic section records 5.5 sedimentary cycles consisting of alternations between dune sand deposits and fluvial or lacustrine facies. We analyzed the grain-size and CaCO3 distributions in MGS2, and found that Mz (mean particle diameter) and o (standard deviation) displayed clear variations in peaks and valleys within different sedimentary facies. The CaCO3 content averaged 0.4% in the dune sand deposits, 1.43% in the fluvial facies, and 8.82% in the lacustrine facies. Both the grain-size distribution and CaCO3 contents, which equal the indicators for the alternation among the sedimentary facies, suggest the occurrence of 5.5 cycles. These results suggest that the observed cycles mainly resulted from fluctuations between a cold and dry winter monsoon climate and a warm and humid summer monsoon climate, and that the MGS2 portion experienced at least 5.5 fluctuations between these two extremes. This high-frequency climatic fluctuation indicates a strong influence of millennium-scale variations in the strength of the East Asian winter and summer monsoons in our study area during the Pleniglacial.展开更多
Nanocellulose composites combine the advantages of nanocellulose and composites. Recently, nanocellulose composites have been received more attentions due to their improved properties and promising broad applications....Nanocellulose composites combine the advantages of nanocellulose and composites. Recently, nanocellulose composites have been received more attentions due to their improved properties and promising broad applications. In the past, rapid progress has been made in the synthesis, properties, and mechanism of nanocellulose composites and potential applications were reported. There are a few reports on the increasing applications of nanocellulose composites with focus on the biomedical field, environmental field, electrode and sensor applications. In this article, the recent development of nanocellulose composites was reviewed via some typical examples. In addition to the synthesis methods, improved properties and potential applications were discussed. The problems and future applications of nanocellulose composites were also suggested.展开更多
Superconductivity is one of most intriguing quantum phenomena,and the quest for elemental superconductors with high critical temperature(T_(c))is of great scientific significance due to their relatively simple materia...Superconductivity is one of most intriguing quantum phenomena,and the quest for elemental superconductors with high critical temperature(T_(c))is of great scientific significance due to their relatively simple material composition and the underlying mechanism.Here we report the experimental discovery of densely compressed scandium(Sc)becoming the first elemental superconductor with T_(c)breaking into 30 K range,which is comparable to the T_(c)values of the classic La-Ba-Cu-O or LaFeAsO superconductors.Our results show that T_(c)^(onset)of Sc increases from~3K at around 43GPa to~32K at about 283GPa(T_(c)^(zero)~31 K),which is well above liquid neon temperature.Interestingly,measured T_(c)shows no sign of saturation up to the maximum pressure achieved in our experiments,indicating that T_(c)may be even higher upon further compression.展开更多
Heterojunction composites with intimate interfaces can shorten the diffusion distance,which leads to a shorter path for photogenerated carriers,thereby increasing photocatalytic activity.Herein,we report the fabricati...Heterojunction composites with intimate interfaces can shorten the diffusion distance,which leads to a shorter path for photogenerated carriers,thereby increasing photocatalytic activity.Herein,we report the fabrication of Ti_(3)C_(2)-Bi_(2)WO_(6)(TC-BW)heterojunctions hinged by Bi_(2)Ti_(2)O_(7)joints via an in situ hydrothermal reaction of Ti_(3)C_(2)in the presence of Na_(2)WO_(4)and Bi(NO_(3))_(3).The TC-BW was characterized using X-ray diffraction(XRD),scanning transmission electron microscopy(STEM),and Raman spectroscopy.TC-BW showed superior photocatalytic activity(productivity over 15TC-WB reaches up to 5.0 mmolreacted BA·gcat.^(−1)·h^(−1))in the oxidation of benzyl alcohol using light-emitting diode(LED)light,arising from the surface defects and intimate heterojunction interface between the Ti_(3)C_(2)MXene and Bi_(2)WO_(6)nanosheets.TC-BW heterojunctions provide an enhanced separation efficiency of photogenerated charges,which in turn yields superior photocatalytic activity.Furthermore,it is well substantiated by density functional theory(DFT)calculations.In summary,this study elucidates the preparation of heterojunction composites with intimate interfaces for highly efficient photooxidation.展开更多
Objective: Adjuvant chemotherapy (AC) after curative resection is known to improve the survival of patients with non-small cell lung cancer (NSCLC); however, few studies have reported the correlation between the time ...Objective: Adjuvant chemotherapy (AC) after curative resection is known to improve the survival of patients with non-small cell lung cancer (NSCLC); however, few studies have reported the correlation between the time to initiation of AC (TTAC) and survival in NSCLC patients. Methods: The clinical data of 925 NSCLC patients who received curative resection and post-operative AC at the Cancer Hospital of Chinese Academy of Medical Sciences between 2003 and 2013 were retrospectively analyzed. TTAC was measured from the date of surgery to the initiation of AC. Disease-free survival (DFS) was defined as the duration from surgery to the time of tumor recurrence or last follow-up evaluation. The optimal cut-off value of TTAC was determined by maximally selected log-rank statistics. The DFS curve was estimated using the Kaplan-Meier method, and the Cox proportional hazards regression model was used to identify risk factors independently associated with DFS. Propensity score matching (PSM) was performed for survival analysis using the match data. Results: The optimal discriminating cut-off value of TTAC was set at d 35 after curative resection based on which the patients were assigned into two groups: group A (<= 35 d) and group B (> 35 d). There was no significant difference in the DFS between the two groups (P=0.246), indicating that the TTAC is not an independent prognostic factor for DFS. A further comparison continued to show no significant difference in the DFS among 258 PSM pairs (P=0.283). Conclusions: There was no significant correlation between the TTAC and DFS in NSCLC patients. Studies with larger samples are needed to further verify this conclusion.展开更多
In multiple sclerosis, gray matter atrophy is extensive, and cognitive deficits and mood disorders are frequently encountered. It has been conjectured that focal atrophy is associated with emotional decline. However, ...In multiple sclerosis, gray matter atrophy is extensive, and cognitive deficits and mood disorders are frequently encountered. It has been conjectured that focal atrophy is associated with emotional decline. However, conventional MRI has revealed that the pathological characteristics cannot fully account for the mood disorders. Moreover, there is no correlation between cognitive disorders and MRI results in clinically isolated syndromes or in cases of definite multiple sclerosis. In this casecontrol study, voxel-based morphometric analysis was performed on 11 subjects with relapsing-remitting multiple sclerosis, and the results show that these patients exhibit gray matter atrophy. Moreover, the gray matter atrophy in the superior and middle gyri of the right frontal lobe in patients with multiple sclerosis was correlated with scores from the Hamilton Anxiety Rating Scale. The scores obtained with the Repeatable Battery for the Assessment of Neuropsychological Status were associated with gray matter atrophy in the middle gyrus of the left frontal lobe, the superior and middle gyrus of the right frontal lobe, the middle gyrus of the left cingulate, the superior and middle gyri of the left frontal lobe, and the triangular area of the left frontal lobe. However, there was no statistical significance. These findings suggest that the cingulate and frontal cortices of the dominant hemisphere are the most severely atrophic regions of the brain, and this atrophy is correlated with cognitive decline and emotional abnormalities.展开更多
The Old Red Sand is composed of brown-red, red, or orange-yellow semi-cemented and medium-fine sand sediment, mainly dis- tributed along the southeast coast of China. Based on previous studies, this paper summarizes t...The Old Red Sand is composed of brown-red, red, or orange-yellow semi-cemented and medium-fine sand sediment, mainly dis- tributed along the southeast coast of China. Based on previous studies, this paper summarizes the distribution and forms, sedi- mentary characteristics, formation mechanism, developing age, reddening process and the paleo-environment, suggesting that the Old Red Sand is mainly aeolian sediment of Late Pleistocene Age. The reddening process is mainly the result of decomposition and oxidation of iron-containing minerals caused by hot and humid tropical and sub-tropical climate. In this study, existing prob- lems are discussed and the prospect of further research is presented as well.展开更多
Morphological effects of nanoparticles are crucial in many solid-catalyzed chemical transformations.We herein prepared two manganese-ceria solid solutions,well-defined MnCeO_(x)nanorods and MnCeO_(x)-nanocubes,exposin...Morphological effects of nanoparticles are crucial in many solid-catalyzed chemical transformations.We herein prepared two manganese-ceria solid solutions,well-defined MnCeO_(x)nanorods and MnCeO_(x)-nanocubes,exposing preferentially(111)and(100)facets of ceria,respectively.The incorporation of Mn dopant into ceria lattice strongly enhanced the catalytic performance in the NO reduction with CO.MnCeO_(x)(111)catalyst outperformed MnCeO_(x)(100)counterpart due to its higher population density of oxygen vacancy defects.In-situ infrared spectroscopy investigations indicated that the reaction pathway over MnCeO_(x)and pristine CeO_(2)is similar and that besides the direct pathway,an indirect pathway via adsorbed hyponitrite as an intermediate cannot be ruled out.X-ray photoelectron and Raman spectroscopies as well as first-principles density functional theory(DFT)calculations indicate that the enhanced catalytic performance of MnCeO_(x)can be traced back to its“Mn–OL(VÖ)–Mn–OL(VÖ)–Ce”connectivities.The Mn dopant strongly facilitates the formation of surface oxygen vacancies(VÖ)by liberating surface lattice oxygen(OL)via CO*+OL→CO_(2)*+VÖand promotes the reduction of NO,according to NO*+VÖ→N*+OL and 2N*→N_(2).The Mn dopant impact on both the adsorption of CO and activation of OL reveals that a balance between these two effects is critical for facilitating all reaction steps.展开更多
Summary What is already known about this topic?Congenital heart defects(CHDs)represent the most prevalent birth defects in China,exhibiting significant mortality and morbidity rates.Recent years have witnessed a stead...Summary What is already known about this topic?Congenital heart defects(CHDs)represent the most prevalent birth defects in China,exhibiting significant mortality and morbidity rates.Recent years have witnessed a steady increase in the occurrence of CHDs,highlighting a crucial need for rigorous research focus.展开更多
Summary What is already known about this topic?Robust evidence indicates that supplementing with folic acid periconceptionally may decrease the risk of neural tube defects(NTDs)in fetuses.What is added by this report?...Summary What is already known about this topic?Robust evidence indicates that supplementing with folic acid periconceptionally may decrease the risk of neural tube defects(NTDs)in fetuses.What is added by this report?Over half of the mothers in both the NTD case group and the control group utilized folic acid supplements during the periconceptional period,showing no notable variations between the two groups.展开更多
Summary What is already known about this topic?Interpregnancy intervals(IPIs)that are either excessively long or short have been linked with an elevated risk of adverse perinatal outcomes.Presently,no pertinent guidel...Summary What is already known about this topic?Interpregnancy intervals(IPIs)that are either excessively long or short have been linked with an elevated risk of adverse perinatal outcomes.Presently,no pertinent guidelines have been established in China to provide clear direction with regard to optimal IPI.What is added by this report?A brief interpregnancy interval may elevate the risk of miscarriage,postpartum hemorrhage,and fetal distress among expectant women.What are the implications for public health practice?展开更多
Summary What is already known about this topic?The primary causes of early miscarriage and stillbirth are chromosomal abnormalities(CAs)whose prevalence has been observed to increase in recent years.What is added by t...Summary What is already known about this topic?The primary causes of early miscarriage and stillbirth are chromosomal abnormalities(CAs)whose prevalence has been observed to increase in recent years.What is added by this report?According to data received from a hospital-based birthdefect surveillance system in the Haidian District,Beijing,there was a significant increase in the prevalence of CAs along with most subtypes from 2013 to 2022.展开更多
Summary What is already known about this topic?Inconsistent results have been reported on the association between periconceptional folic acid only(FAO)or multiple micronutrients containing folic acid(MMFA)supplementat...Summary What is already known about this topic?Inconsistent results have been reported on the association between periconceptional folic acid only(FAO)or multiple micronutrients containing folic acid(MMFA)supplementation and the risk of gestational diabetes mellitus(GDM)in previous research.What is added by this report?In a prospective cohort study conducted among pregnant women in Haidian District,Beijing Municipality,it was observed that those who took MMFA demonstrated a higher likelihood of developing GDM in comparison to those who consumed FAO periconceptionally.Interestingly,the increased risk for GDM in pregnant women supplemented with MMFA compared to FAO was primarily due to changes in fasting plasma glucose.What are the implications for public health practice?It is highly recommended that women prioritize the use of FAO in order to yield potential benefits in the prevention of GDM.展开更多
1.Introduction In recent decade,atomically precise metal nanoclusters,comprised of metal kernel and surface protecting ligands,have appeared as a new and promising nanomaterial for abundant applications,such as nanoca...1.Introduction In recent decade,atomically precise metal nanoclusters,comprised of metal kernel and surface protecting ligands,have appeared as a new and promising nanomaterial for abundant applications,such as nanocatalysis,sensor,photoluminescence,a few to name,which is attributed to their electron energy quantization arising from quantum size effect[1].And the very recent investigations showed that the configuration of metal kernel and the electronic properties of metal nanoclusters with the same metal core are largely affected by the surface protecting ligands[[2],[3]].For example,the surface ligands can significantly alter the catalytic performance of metal nanocluster catalysts(e.g.activity and selectivity)in a positive way.We have found that the Au_(25)(SR)_(18)nanocluster with the aromatic ligands can give higher conversions and a markedly increasing selectivity toward the desired product[4].展开更多
The use of robots to augment human capabilities and assist in work has long been an aspiration.Robotics has been developing since the 1960s when the first industrial robot was introduced.As technology has advanced,rob...The use of robots to augment human capabilities and assist in work has long been an aspiration.Robotics has been developing since the 1960s when the first industrial robot was introduced.As technology has advanced,robotic-assisted surgery has shown numerous advantages,including more precision,efficiency,minimal invasiveness,and safety than is possible with conventional techniques,which are research hotspots and cutting-edge trends.This article reviewed the history of medical robot development and seminal research papers about current research progress.Taking the autonomous dental implant robotic system as an example,the advantages and prospects of medical robotic systems would be discussed which would provide a reference for future research.展开更多
With the increasing demand for high integration and multi-color photodetection for both military and civilian applications, the research of multi-wavelength detectors has become a new research hotspot. However, curren...With the increasing demand for high integration and multi-color photodetection for both military and civilian applications, the research of multi-wavelength detectors has become a new research hotspot. However, current research has been mainly in visible dual-or multi-wavelength detectors, while integration of both visible light and ultraviolet(UV) dual-wavelength detectors has rarely been studied. In this work, large-scale and high-quality monolayer MoS2 was grown by the chemical vapor deposition method on transparent free-standing GaN substrate. Monolithic integration of MoS2-based visible detectors and GaN-based UV detectors was demonstrated using common semiconductor fabrication technologies such as photolithography, argon plasma etching, and metal deposition. High performance of a 280 nm and 405 nm dual-wavelength photodetector was realized.The responsivity of the UV detector reached 172.12 A/W, while that of the visible detector reached 17.5 A/W.Meanwhile, both photodetectors achieved high photocurrent gain, high external quantum efficiency, high normalized detection rate, and low noise equivalent power. Our study extends the future application of dual-wavelength detectors for image sensing and optical communication.展开更多
Summary What is already known about this topic?Metabolic syndrome(MetS)is one of the most easily available health indicative markers for cardiovascular diseases,and it has become a major public health problem worldwid...Summary What is already known about this topic?Metabolic syndrome(MetS)is one of the most easily available health indicative markers for cardiovascular diseases,and it has become a major public health problem worldwide due to increasing urbanization and aging populations.The prevalence of MetS increased dramatically in China,however,there are no records of MetS defined by the 2017 Chinese Diabetes Society for Beijing by far.What is added by this report?In this study,the data of 24,412 participants aged 18–74 years from a large population-based study in Beijing was collected.The overall prevalence of MetS among Beijing residents was 24.5%.The prevalence was 35.2%in males and 15.4%in females.What are the implications for public health practice?Effective public health strategies should target males,people with older age,lower education,higher body mass index,smokers,those who drink alcohol,those who are unemployed or retired,and those who live in rural areas on MetS prevention and control.展开更多
Strain regulation as an effective way to enhance the photoelectric properties of two dimensional(2D)transition metal dichalcogenides has been widely employed to improve the performance of photovoltaic devices.In this ...Strain regulation as an effective way to enhance the photoelectric properties of two dimensional(2D)transition metal dichalcogenides has been widely employed to improve the performance of photovoltaic devices.In this work,tensile strain was introduced in multilayer MoS2 grown on GaN by depositing 3 nm of Al2O3 on the surface.The temperature dependent Raman spectrum shows that the thermal stability of MoS2 is improved by Al2O3.Theoretical simulations confirmed the existence of tensile strain on MoS2 covered with Al2O3,and the bandgap and electron effective mass of six layers of MoS2 decreased due to tensile strain,which resulted in an increase of electron mobility.Due to the tensile strain ffect,the photodetector with the Al2O3 stress liner achieved better performance under the illumination of 365 nm wavelength,including a higher responsivity of 24.6 A/W,photoconductive gain of 520,and external quantum fficiency of 8381%,which are more than twice the corresponding values of photodetectors without Al2O3.Our work provides an effective technical way for improving the performance of 2D material photodetectors.展开更多
基金the National Key Research and Development Program of China(Grant Nos.2018YFA0305700,2018YFE0202600,and 2022YFA1403800)the Beijing Natural Science Foundation(Grant Nos.2202059 and Z200005)+2 种基金the National Natural Science Foundation of China(Grant Nos.22171283 and 12274459)the Hebei Natural Science Foundation(Grant No.B2020205040)the Beijing National Laboratory for Condensed Matter Physics。
文摘Pressure induced insulator to metal transition followed by the appearance of superconductivity has been observed recently in inorganic quantum spin liquid candidate NaYbSe_(2).In this paper,we study the properties of isostructural compound NaYbS_(2)under pressure.It is found that the resistance of Na YbS_(2)single crystal exhibits an insulating state below 82.9 GPa,but with a drop of more than six orders of magnitude at room temperature.Then a minimum of resistance is observed at about 100.1 GPa and it moves to lower temperature with further compression.Finally,a metallic state in the whole temperature range is observed at about 130.3 GPa accompanied by a non-Fermi liquid behavior below 100 K.The insulator to metal transition,non-monotonic resistance feature and non-Fermi liquid behavior of NaYbS_(2)under pressure are similar to those of NaYbSe_(2),suggesting that these phenomena might be the universal properties in NaLnCh_(2)(Ln=rare earth,Ch=O,S,Se)system.
基金funded by the National Basic Research Program of China (2010CB833405, 2004CB720206)the National Natural Science Foundation of China (40772118, 49971009)+2 种基金Foundation of the State Key Laboratory of Loess and Quaternary Geology, Institute of Earth Environment, Chinese Academy of Sciences (SKLLQG0309)the Research Grants Council Grant of the Hong Kong Special Administrative Region(HKU7243/04H)the Knowledge Innovation Project of Chinese Academy of Sciences (KZCX2-SW-118)
文摘Situated in the Salawusu River Valley, southeast of China's Mu Us Desert, the MGS2 (Milanggouwan section) portion of the Milanggouwan stratigraphic section records 5.5 sedimentary cycles consisting of alternations between dune sand deposits and fluvial or lacustrine facies. We analyzed the grain-size and CaCO3 distributions in MGS2, and found that Mz (mean particle diameter) and o (standard deviation) displayed clear variations in peaks and valleys within different sedimentary facies. The CaCO3 content averaged 0.4% in the dune sand deposits, 1.43% in the fluvial facies, and 8.82% in the lacustrine facies. Both the grain-size distribution and CaCO3 contents, which equal the indicators for the alternation among the sedimentary facies, suggest the occurrence of 5.5 cycles. These results suggest that the observed cycles mainly resulted from fluctuations between a cold and dry winter monsoon climate and a warm and humid summer monsoon climate, and that the MGS2 portion experienced at least 5.5 fluctuations between these two extremes. This high-frequency climatic fluctuation indicates a strong influence of millennium-scale variations in the strength of the East Asian winter and summer monsoons in our study area during the Pleniglacial.
基金Financial supported from the Fundamental Research Funds for the Central Universities (No. 2017ZY49)the Foundation (No. KF201607) of Key Laboratory of Pulp and Paper Science and Technology of Ministry of Education/Shandong Province of China
文摘Nanocellulose composites combine the advantages of nanocellulose and composites. Recently, nanocellulose composites have been received more attentions due to their improved properties and promising broad applications. In the past, rapid progress has been made in the synthesis, properties, and mechanism of nanocellulose composites and potential applications were reported. There are a few reports on the increasing applications of nanocellulose composites with focus on the biomedical field, environmental field, electrode and sensor applications. In this article, the recent development of nanocellulose composites was reviewed via some typical examples. In addition to the synthesis methods, improved properties and potential applications were discussed. The problems and future applications of nanocellulose composites were also suggested.
基金supported by the National Key R&D Program of China(Grant No.2021YFA1401800,2022YFA1403800,and 2022YFA1403900)the National Natural Science Foundation of China(Grant Nos.11921004 and U2032220)+1 种基金Chinese Academy of Sciences(Grant No.XDB33010200)NSERC Canada for a Discovery Grant。
文摘Superconductivity is one of most intriguing quantum phenomena,and the quest for elemental superconductors with high critical temperature(T_(c))is of great scientific significance due to their relatively simple material composition and the underlying mechanism.Here we report the experimental discovery of densely compressed scandium(Sc)becoming the first elemental superconductor with T_(c)breaking into 30 K range,which is comparable to the T_(c)values of the classic La-Ba-Cu-O or LaFeAsO superconductors.Our results show that T_(c)^(onset)of Sc increases from~3K at around 43GPa to~32K at about 283GPa(T_(c)^(zero)~31 K),which is well above liquid neon temperature.Interestingly,measured T_(c)shows no sign of saturation up to the maximum pressure achieved in our experiments,indicating that T_(c)may be even higher upon further compression.
基金the National Natural Science Foundation of China(Nos.22172167 and 22272112).
文摘Heterojunction composites with intimate interfaces can shorten the diffusion distance,which leads to a shorter path for photogenerated carriers,thereby increasing photocatalytic activity.Herein,we report the fabrication of Ti_(3)C_(2)-Bi_(2)WO_(6)(TC-BW)heterojunctions hinged by Bi_(2)Ti_(2)O_(7)joints via an in situ hydrothermal reaction of Ti_(3)C_(2)in the presence of Na_(2)WO_(4)and Bi(NO_(3))_(3).The TC-BW was characterized using X-ray diffraction(XRD),scanning transmission electron microscopy(STEM),and Raman spectroscopy.TC-BW showed superior photocatalytic activity(productivity over 15TC-WB reaches up to 5.0 mmolreacted BA·gcat.^(−1)·h^(−1))in the oxidation of benzyl alcohol using light-emitting diode(LED)light,arising from the surface defects and intimate heterojunction interface between the Ti_(3)C_(2)MXene and Bi_(2)WO_(6)nanosheets.TC-BW heterojunctions provide an enhanced separation efficiency of photogenerated charges,which in turn yields superior photocatalytic activity.Furthermore,it is well substantiated by density functional theory(DFT)calculations.In summary,this study elucidates the preparation of heterojunction composites with intimate interfaces for highly efficient photooxidation.
文摘Objective: Adjuvant chemotherapy (AC) after curative resection is known to improve the survival of patients with non-small cell lung cancer (NSCLC); however, few studies have reported the correlation between the time to initiation of AC (TTAC) and survival in NSCLC patients. Methods: The clinical data of 925 NSCLC patients who received curative resection and post-operative AC at the Cancer Hospital of Chinese Academy of Medical Sciences between 2003 and 2013 were retrospectively analyzed. TTAC was measured from the date of surgery to the initiation of AC. Disease-free survival (DFS) was defined as the duration from surgery to the time of tumor recurrence or last follow-up evaluation. The optimal cut-off value of TTAC was determined by maximally selected log-rank statistics. The DFS curve was estimated using the Kaplan-Meier method, and the Cox proportional hazards regression model was used to identify risk factors independently associated with DFS. Propensity score matching (PSM) was performed for survival analysis using the match data. Results: The optimal discriminating cut-off value of TTAC was set at d 35 after curative resection based on which the patients were assigned into two groups: group A (<= 35 d) and group B (> 35 d). There was no significant difference in the DFS between the two groups (P=0.246), indicating that the TTAC is not an independent prognostic factor for DFS. A further comparison continued to show no significant difference in the DFS among 258 PSM pairs (P=0.283). Conclusions: There was no significant correlation between the TTAC and DFS in NSCLC patients. Studies with larger samples are needed to further verify this conclusion.
文摘In multiple sclerosis, gray matter atrophy is extensive, and cognitive deficits and mood disorders are frequently encountered. It has been conjectured that focal atrophy is associated with emotional decline. However, conventional MRI has revealed that the pathological characteristics cannot fully account for the mood disorders. Moreover, there is no correlation between cognitive disorders and MRI results in clinically isolated syndromes or in cases of definite multiple sclerosis. In this casecontrol study, voxel-based morphometric analysis was performed on 11 subjects with relapsing-remitting multiple sclerosis, and the results show that these patients exhibit gray matter atrophy. Moreover, the gray matter atrophy in the superior and middle gyri of the right frontal lobe in patients with multiple sclerosis was correlated with scores from the Hamilton Anxiety Rating Scale. The scores obtained with the Repeatable Battery for the Assessment of Neuropsychological Status were associated with gray matter atrophy in the middle gyrus of the left frontal lobe, the superior and middle gyrus of the right frontal lobe, the middle gyrus of the left cingulate, the superior and middle gyri of the left frontal lobe, and the triangular area of the left frontal lobe. However, there was no statistical significance. These findings suggest that the cingulate and frontal cortices of the dominant hemisphere are the most severely atrophic regions of the brain, and this atrophy is correlated with cognitive decline and emotional abnormalities.
基金supported by National Natural Science Foundation of China (No. 40971007)
文摘The Old Red Sand is composed of brown-red, red, or orange-yellow semi-cemented and medium-fine sand sediment, mainly dis- tributed along the southeast coast of China. Based on previous studies, this paper summarizes the distribution and forms, sedi- mentary characteristics, formation mechanism, developing age, reddening process and the paleo-environment, suggesting that the Old Red Sand is mainly aeolian sediment of Late Pleistocene Age. The reddening process is mainly the result of decomposition and oxidation of iron-containing minerals caused by hot and humid tropical and sub-tropical climate. In this study, existing prob- lems are discussed and the prospect of further research is presented as well.
基金the National Natural Science Foundation of China(Nos.22065029 and 22172167)the Natural Science Foundation of Inner Mongolia Autonomous Region(No.2022MS02002).
文摘Morphological effects of nanoparticles are crucial in many solid-catalyzed chemical transformations.We herein prepared two manganese-ceria solid solutions,well-defined MnCeO_(x)nanorods and MnCeO_(x)-nanocubes,exposing preferentially(111)and(100)facets of ceria,respectively.The incorporation of Mn dopant into ceria lattice strongly enhanced the catalytic performance in the NO reduction with CO.MnCeO_(x)(111)catalyst outperformed MnCeO_(x)(100)counterpart due to its higher population density of oxygen vacancy defects.In-situ infrared spectroscopy investigations indicated that the reaction pathway over MnCeO_(x)and pristine CeO_(2)is similar and that besides the direct pathway,an indirect pathway via adsorbed hyponitrite as an intermediate cannot be ruled out.X-ray photoelectron and Raman spectroscopies as well as first-principles density functional theory(DFT)calculations indicate that the enhanced catalytic performance of MnCeO_(x)can be traced back to its“Mn–OL(VÖ)–Mn–OL(VÖ)–Ce”connectivities.The Mn dopant strongly facilitates the formation of surface oxygen vacancies(VÖ)by liberating surface lattice oxygen(OL)via CO*+OL→CO_(2)*+VÖand promotes the reduction of NO,according to NO*+VÖ→N*+OL and 2N*→N_(2).The Mn dopant impact on both the adsorption of CO and activation of OL reveals that a balance between these two effects is critical for facilitating all reaction steps.
基金Supported by the National Key Research and Development Program,Ministry of Science and Technology of the People’s Republic of China(No.2021YFC2701101)National Natural Science Foundation of China(No.82171661,No.81973056,No.82373582).
文摘Summary What is already known about this topic?Congenital heart defects(CHDs)represent the most prevalent birth defects in China,exhibiting significant mortality and morbidity rates.Recent years have witnessed a steady increase in the occurrence of CHDs,highlighting a crucial need for rigorous research focus.
基金National Natural Science Foundation of China(No.81973056 and No.82373582)the National Key Research and Development Program,Ministry of Science and Technology of the People’s Republic of China(No.2021YFC2701001).
文摘Summary What is already known about this topic?Robust evidence indicates that supplementing with folic acid periconceptionally may decrease the risk of neural tube defects(NTDs)in fetuses.What is added by this report?Over half of the mothers in both the NTD case group and the control group utilized folic acid supplements during the periconceptional period,showing no notable variations between the two groups.
基金Supported by Beijing Natural Science Foundation(No.722248)National Natural Science Foundation of China(No.81673177).
文摘Summary What is already known about this topic?Interpregnancy intervals(IPIs)that are either excessively long or short have been linked with an elevated risk of adverse perinatal outcomes.Presently,no pertinent guidelines have been established in China to provide clear direction with regard to optimal IPI.What is added by this report?A brief interpregnancy interval may elevate the risk of miscarriage,postpartum hemorrhage,and fetal distress among expectant women.What are the implications for public health practice?
基金Supported by National Key Research and Development Program,Ministry of Science and Technology of the People’s Republic of China(No.2021YFC2701101)National Natural Science Foundation of China(No.82171661,No.82373582).
文摘Summary What is already known about this topic?The primary causes of early miscarriage and stillbirth are chromosomal abnormalities(CAs)whose prevalence has been observed to increase in recent years.What is added by this report?According to data received from a hospital-based birthdefect surveillance system in the Haidian District,Beijing,there was a significant increase in the prevalence of CAs along with most subtypes from 2013 to 2022.
基金Funds for the Central Universities(BMU2021YJ034)CNS-ZD Tizhi and Health Fund(CNS-ZD2020-115)National Natural Science Foundation of China(81673177).
文摘Summary What is already known about this topic?Inconsistent results have been reported on the association between periconceptional folic acid only(FAO)or multiple micronutrients containing folic acid(MMFA)supplementation and the risk of gestational diabetes mellitus(GDM)in previous research.What is added by this report?In a prospective cohort study conducted among pregnant women in Haidian District,Beijing Municipality,it was observed that those who took MMFA demonstrated a higher likelihood of developing GDM in comparison to those who consumed FAO periconceptionally.Interestingly,the increased risk for GDM in pregnant women supplemented with MMFA compared to FAO was primarily due to changes in fasting plasma glucose.What are the implications for public health practice?It is highly recommended that women prioritize the use of FAO in order to yield potential benefits in the prevention of GDM.
文摘1.Introduction In recent decade,atomically precise metal nanoclusters,comprised of metal kernel and surface protecting ligands,have appeared as a new and promising nanomaterial for abundant applications,such as nanocatalysis,sensor,photoluminescence,a few to name,which is attributed to their electron energy quantization arising from quantum size effect[1].And the very recent investigations showed that the configuration of metal kernel and the electronic properties of metal nanoclusters with the same metal core are largely affected by the surface protecting ligands[[2],[3]].For example,the surface ligands can significantly alter the catalytic performance of metal nanocluster catalysts(e.g.activity and selectivity)in a positive way.We have found that the Au_(25)(SR)_(18)nanocluster with the aromatic ligands can give higher conversions and a markedly increasing selectivity toward the desired product[4].
基金supported by the National Natural Science Foundation of China[grant number 81970987].
文摘The use of robots to augment human capabilities and assist in work has long been an aspiration.Robotics has been developing since the 1960s when the first industrial robot was introduced.As technology has advanced,robotic-assisted surgery has shown numerous advantages,including more precision,efficiency,minimal invasiveness,and safety than is possible with conventional techniques,which are research hotspots and cutting-edge trends.This article reviewed the history of medical robot development and seminal research papers about current research progress.Taking the autonomous dental implant robotic system as an example,the advantages and prospects of medical robotic systems would be discussed which would provide a reference for future research.
基金National Key Research and Development Plan(2017YFB0403000)National Science Fund for Distinguished Young Scholars(61725403)+6 种基金National Natural Science Foundation of China(61874118,61704171,61504083,61674161)CAS Pioneer Hundred Talents ProgramJilin Provincial Science&Technology Department(20180201026GX)Key Program of the International Partnership Program of CAS(181722KYSB20160015)Special Project for Inter-government Collaboration of the State Key Research and Development Program(2016YFE0118400)Youth Innovation Promotion Association of CASGuangdong Province Key Research and Development Plan(2019B010138002)。
文摘With the increasing demand for high integration and multi-color photodetection for both military and civilian applications, the research of multi-wavelength detectors has become a new research hotspot. However, current research has been mainly in visible dual-or multi-wavelength detectors, while integration of both visible light and ultraviolet(UV) dual-wavelength detectors has rarely been studied. In this work, large-scale and high-quality monolayer MoS2 was grown by the chemical vapor deposition method on transparent free-standing GaN substrate. Monolithic integration of MoS2-based visible detectors and GaN-based UV detectors was demonstrated using common semiconductor fabrication technologies such as photolithography, argon plasma etching, and metal deposition. High performance of a 280 nm and 405 nm dual-wavelength photodetector was realized.The responsivity of the UV detector reached 172.12 A/W, while that of the visible detector reached 17.5 A/W.Meanwhile, both photodetectors achieved high photocurrent gain, high external quantum efficiency, high normalized detection rate, and low noise equivalent power. Our study extends the future application of dual-wavelength detectors for image sensing and optical communication.
基金Research Special Fund for Municipal Medical Public Welfare Institute(2017-BJYJ-15)National Natural Science Foundation of China(81373014)CNS-ZD Tizhi and Health Fund(CNSZD2020-115).
文摘Summary What is already known about this topic?Metabolic syndrome(MetS)is one of the most easily available health indicative markers for cardiovascular diseases,and it has become a major public health problem worldwide due to increasing urbanization and aging populations.The prevalence of MetS increased dramatically in China,however,there are no records of MetS defined by the 2017 Chinese Diabetes Society for Beijing by far.What is added by this report?In this study,the data of 24,412 participants aged 18–74 years from a large population-based study in Beijing was collected.The overall prevalence of MetS among Beijing residents was 24.5%.The prevalence was 35.2%in males and 15.4%in females.What are the implications for public health practice?Effective public health strategies should target males,people with older age,lower education,higher body mass index,smokers,those who drink alcohol,those who are unemployed or retired,and those who live in rural areas on MetS prevention and control.
基金National Key Research and Development Program of China(2017YFB0403000)National Natural Science Foundation of China(61974144)+1 种基金Guangdong Province Key Research and Development Plan(2019B010138002)Key Research and Development Program of Guangdong Province(2020B010174003).
文摘Strain regulation as an effective way to enhance the photoelectric properties of two dimensional(2D)transition metal dichalcogenides has been widely employed to improve the performance of photovoltaic devices.In this work,tensile strain was introduced in multilayer MoS2 grown on GaN by depositing 3 nm of Al2O3 on the surface.The temperature dependent Raman spectrum shows that the thermal stability of MoS2 is improved by Al2O3.Theoretical simulations confirmed the existence of tensile strain on MoS2 covered with Al2O3,and the bandgap and electron effective mass of six layers of MoS2 decreased due to tensile strain,which resulted in an increase of electron mobility.Due to the tensile strain ffect,the photodetector with the Al2O3 stress liner achieved better performance under the illumination of 365 nm wavelength,including a higher responsivity of 24.6 A/W,photoconductive gain of 520,and external quantum fficiency of 8381%,which are more than twice the corresponding values of photodetectors without Al2O3.Our work provides an effective technical way for improving the performance of 2D material photodetectors.