This study aimed to obtain the first national estimate of the prevalence of autism spectrum disorder(ASD) in Chinese children.We targeted the population of 6 to 12-year-old children for this prevalence study by multis...This study aimed to obtain the first national estimate of the prevalence of autism spectrum disorder(ASD) in Chinese children.We targeted the population of 6 to 12-year-old children for this prevalence study by multistage convenient cluster sampling.The Modified Chinese Autism Spectrum Rating Scale was used for the screening process.Of the target population of 142,086 children,88.5%(n=125,806) participated in the study.A total of 363 children were confirmed as having ASD.The observed ASD prevalence rate was 0.29%(95% CI:0.26%-0.32%) for the overall population.After adjustment for response rates,the estimated number of ASD cases was867 in the target population sample,thereby achieving an estimated prevalence of 0.70%(95% CI:0.64%-0.74%).The prevalence was significantly higher in boys than in girls(0.95%;95% CI:0.87%-1.02% versus 0.30%;95%CI:0.26%-0.34%;P <0.001).Of the 363 confirmed ASD cases,43.3% were newly diagnosed,and most of those(90.4%) were attending regular schools,and 68.8% of the children with ASD had at least one neuropsychiatric comorbidity.Our findings provide reliable data on the estimated ASD prevalence and comorbidities in Chinese children.展开更多
Currently,pyroptosis has received more and more attention because of its association with innate immunity and disease.The research scope of pyroptosis has expanded with the discovery of the gasdermin family.A great de...Currently,pyroptosis has received more and more attention because of its association with innate immunity and disease.The research scope of pyroptosis has expanded with the discovery of the gasdermin family.A great deal of evidence shows that pyroptosis can affect the development of tumors.The relationship between pyroptosis and tumors is diverse in different tissues and genetic backgrounds.In this review,we provide basic knowledge of pyroptosis,explain the relationship between pyroptosis and tumors,and focus on the significance of pyroptosis in tumor treatment.In addition,we further summarize the possibility of pyroptosis as a potential tumor treatment strategy and describe the side effects of radiotherapy and chemotherapy caused by pyroptosis.In brief,pyroptosis is a double-edged sword for tumors.The rational use of this dual effect will help us further explore the formation and development of tumors,and provide ideas for patients to develop new drugs based on pyroptosis.展开更多
Background： Atopic dermatitis （AD） is an inflammatory skin disease characterized by chronic recurrent dermatitis with profound itching. Most patients have personal and/or family history of atopic diseases. Several ...Background： Atopic dermatitis （AD） is an inflammatory skin disease characterized by chronic recurrent dermatitis with profound itching. Most patients have personal and/or family history of atopic diseases. Several criteria have been proposed for the diagnosis of AD. Although the clinical features of childhood AD have been widely studied, there has been less large-scale study on adult/adolescent AD. The aim of this study was to investigate the clinical features of adult/adolescent patients with chronic symmetrical eczemaJAD and to propose Chinese diagnostic criteria for adult/adolescent AD. Methods： A hospital-based study was performed. Forty-two dermatological centers participated in this study. Adult and adolescent patients （12 years and over） with chronic symmetrical eczema or AD were included in this study. Questionnaires were completed by both patients and-investigators. The valid questionnaires were analyzed using EpiData 3.1 and SPSS 17.0 software. Results： A total of 2662 valid questionnaires were collected （1369 male and 1293 female）. Of all 2662 patients, 2062 （77.5%） patients had the disease after 12 years old, while only 600 （22.5%） patients had the disease before 12 years old, suggesting late-onset eczema/AD is common. Two thousand one hundred and thirty-nine （80.4%） patients had the disease for more than 6 months. One thousand one hundred and forty-four （43.0%） patients had a personal and/or family history of atopic diseases. One thousand five hundred and forty-eight （58.2%） patients had an elevated total serum IgE and/or eosinophilia and/or positive allergen-specific IgE. Based on these clinical and laboratory features, we proposed Chinese criteria for adult/adolescent AD. Of all 2662 patients, 60.3% were satisfied with our criteria, while only 48.2% satisfied with Hanifin Rajka criteria and 32.7% satisfied with Williams criteria, suggesting a good sensitivity of our criteria in adult/adolescent AD patients. Conclusion： Late-onset of eczema or AD is common. Th展开更多
Dear Editor Salvia miltiorrhiza Bunge （Danshen） is a medicinal plant of the Lamiaceae family, and its dried roots have long been used in traditional Chinese medicine with hydrophilic phenolic acids and tanshinones a...Dear Editor Salvia miltiorrhiza Bunge （Danshen） is a medicinal plant of the Lamiaceae family, and its dried roots have long been used in traditional Chinese medicine with hydrophilic phenolic acids and tanshinones as pharmaceutically active components （Zhang et al., 2014; Xu et al., 2016）. The first step of tanshinone biosynthesis is bicyclization of the general diterpene precursor （E,E,E）-geranylgeranyl diphosphate （GGPP） to copalyl diphosphate （CPP） by CPP synthases （CPSs）, which is followed by a cyclization or rearrangement reaction catalyzed by kaurene synthase-like enzymes （KSL）. The resulting intermediate is usually an olefin, which requires the insertion of oxygen by cytochrome P450 mono-oxygenases （CYPs） for the final production of diterpenoids （Zi et al., 2014）. While the CPS, KSL, and several early acting CYPs （CYP76AH1, CYP76AH3, and CYP76AK1） for tanshinone biosynthesis have been identified in S. miltiorrhiza （Gao et al., 2009; Guo et al., 2013, 2016; Zi and Peters, 2013）, the majority of the overall biosynthetic pathway, as well as the relevant regulatory factors associated with tanshinone production, remains elusive （Figure 1B）.展开更多
Ferroptosis is an iron-dependent novel cell death pathway. Deferoxamine, a ferroptosis inhibitor, has been reported to promote spinal cord injury repair. It has yet to be clarified whether ferroptosis inhibition repre...Ferroptosis is an iron-dependent novel cell death pathway. Deferoxamine, a ferroptosis inhibitor, has been reported to promote spinal cord injury repair. It has yet to be clarified whether ferroptosis inhibition represents the mechanism of action of Deferoxamine on spinal cord injury recovery. A rat model of Deferoxamine at thoracic 10 segment was established using a modified Allen's method. Ninety 8-week-old female Wistar rats were used. Rats in the Deferoxamine group were intraperitoneally injected with 100 mg/kg Deferoxamine 30 minutes before injury. Simultaneously, the Sham and Deferoxamine groups served as controls. Drug administration was conducted for 7 consecutive days. The results were as follows:(1) Electron microscopy revealed shrunken mitochondria in the spinal cord injury group.(2) The Basso, Beattie and Bresnahan locomotor rating score showed that recovery of the hindlimb was remarkably better in the Deferoxamine group than in the spinal cord injury group.(3) The iron concentration was lower in the Deferoxamine group than in the spinal cord injury group after injury.(4) Western blot assay revealed that, compared with the spinal cord injury group, GPX4, xCT, and glutathione expression was markedly increased in the Deferoxamine group.(5) Real-time polymerase chain reaction revealed that, compared with the Deferoxamine group, mRNA levels of ferroptosis-related genes Acyl-CoA synthetase family member 2(ACSF2) and iron-responsive element-binding protein 2(IREB2) were up-regulated in the Deferoxamine group.(6) Deferoxamine increased survival of neurons and inhibited gliosis. These findings confirm that Deferoxamine can repair spinal cord injury by inhibiting ferroptosis. Targeting ferroptosis is therefore a promising therapeutic approach for spinal cord injury.展开更多
Clayey silt reservoirs bearing natural gas hydrates(NGH)are considered to be the hydrate-bearing reservoirs that boast the highest reserves but tend to be the most difficult to exploit.They are proved to be exploitabl...Clayey silt reservoirs bearing natural gas hydrates(NGH)are considered to be the hydrate-bearing reservoirs that boast the highest reserves but tend to be the most difficult to exploit.They are proved to be exploitable by the first NGH production test conducted in the South China Sea in 2017.Based on the understanding of the first production test,the China Geological Survey determined the optimal target NGH reservoirs for production test and conducted a detailed assessment,numerical and experimental simulation,and onshore testing of the reservoirs.After that,it conducted the second offshore NGH production test in 1225 m deep Shenhu Area,South China Sea(also referred to as the second production test)from October 2019 to April 2020.During the second production test,a series of technical challenges of drilling horizontal wells in shallow soft strata in deep sea were met,including wellhead stability,directional drilling of a horizontal well,reservoir stimulation and sand control,and accurate depressurization.As a result,30 days of continuous gas production was achieved,with a cumulative gas production of 86.14×104 m3.Thus,the average daily gas production is 2.87×10^4 m^3,which is 5.57 times as much as that obtained in the first production test.Therefore,both the cumulative gas production and the daily gas production were highly improved compared to the first production test.As indicated by the monitoring results of the second production test,there was no anomaly in methane content in the seafloor,seawater,and atmosphere throughout the whole production test.This successful production test further indicates that safe and effective NGH exploitation is feasible in clayey silt NGH reservoirs.The industrialization of hydrates consists of five stages in general,namely theoretical research and simulation experiments,exploratory production test,experimental production test,productive production test,and commercial production.The second production test serves as an important step from the exploratory production test to exper展开更多
The New Vacuum Solar Telescope （NVST） is a one meter vacuum solar telescope that aims to observe fine structures on the Sun. The main goals of NVST are high resolution imaging and spectral observations, including me...The New Vacuum Solar Telescope （NVST） is a one meter vacuum solar telescope that aims to observe fine structures on the Sun. The main goals of NVST are high resolution imaging and spectral observations, including measurements of the solar magnetic field. NVST is the primary ground-based facility used by the Chinese solar research community in this solar cycle. It is located by Fuxian Lake in southwest China, where the seeing is good enough to perform high resolution observations. We first introduce the general conditions at the Fuxian Solar Observatory and the primary science cases of NVST. Then, the basic structures of this telescope and instruments are described in detail. Finally, some typical high resolution data of the solar photosphere and chromosphere are also shown.展开更多
Metamaterials based on effective media can be used to produce a number of unusual physical properties(for example,negative refraction and invisibility cloaking)because they can be tailored with effective medium parame...Metamaterials based on effective media can be used to produce a number of unusual physical properties(for example,negative refraction and invisibility cloaking)because they can be tailored with effective medium parameters that do not occur in nature.Recently,the use of coding metamaterials has been suggested for the control of electromagnetic waves through the design of coding sequences using digital elements‘0’and‘1,'which possess opposite phase responses.Here we propose the concept of an anisotropic coding metamaterial in which the coding behaviors in different directions are dependent on the polarization status of the electromagnetic waves.We experimentally demonstrate an ultrathin and flexible polarization-controlled anisotropic coding metasurface that functions in the terahertz regime using specially designed coding elements.By encoding the elements with elaborately designed coding sequences(both 1-bit and 2-bit sequences),the x-and y-polarized waves can be anomalously reflected or independently diffused in three dimensions.The simulated far-field scattering patterns and near-field distributions are presented to illustrate the dual-functional performance of the encoded metasurface,and the results are consistent with the measured results.We further demonstrate the ability of the anisotropic coding metasurfaces to generate a beam splitter and realize simultaneous anomalous reflections and polarization conversions,thus providing powerful control of differently polarized electromagnetic waves.The proposed method enables versatile beam behaviors under orthogonal polarizations using a single metasurface and has the potential for use in the development of interesting terahertz devices.展开更多
The Large Sky Area Multi-Object Fiber Spectroscopic Telescope (LAMOST, also called the Guo Shou Jing Telescope) is a special reflecting Schmidt telescope. LAMOST’s special design allows both a large aperture (effecti...The Large Sky Area Multi-Object Fiber Spectroscopic Telescope (LAMOST, also called the Guo Shou Jing Telescope) is a special reflecting Schmidt telescope. LAMOST’s special design allows both a large aperture (effective aperture of 3.6 m–4.9 m) and a wide field of view (FOV) (5°). It has an innovative active reflecting Schmidt configuration which continuously changes the mirror’s surface that adjusts during the observation process and combines thin deformable mirror active optics with segmented active optics. Its primary mirror (6.67m×6.05 m) and active Schmidt mirror (5.74m×4.40 m) are both segmented, and composed of 37 and 24 hexagonal sub-mirrors respectively. By using a parallel controllable fiber positioning technique, the focal surface of 1.75 m in diameter can accommodate 4000 optical fibers. Also, LAMOST has 16 spectrographs with 32 CCD cameras. LAMOST will be the telescope with the highest rate of spectral acquisition. As a national large scientific project, the LAMOST project was formally proposed in 1996, and approved by the Chinese government in 1997. The construction started in 2001, was completed in 2008 and passed the official acceptance in June 2009. The LAMOST pilot survey was started in October 2011 and the spectroscopic survey will launch in September 2012. Up to now, LAMOST has released more than 480 000 spectra of objects. LAMOST will make an important contribution to the study of the large-scale structure of the Universe, structure and evolution of the Galaxy, and cross-identification of multiwaveband properties in celestial objects.展开更多
Over the past few years, three photorespiratory bypasses have been introduced into plants, two of which led to observable in creases in photos yn thesis and biomass yield. However, most of the experiments were carried...Over the past few years, three photorespiratory bypasses have been introduced into plants, two of which led to observable in creases in photos yn thesis and biomass yield. However, most of the experiments were carried out using Arabidopsis under controlled environmental conditions, and the increases were only observed under low-light and short-day conditions. In this study, we designed a new photorespiratory bypass (called GOC bypass), characterized by no reducing equivalents being produced during a complete oxidation of glycolate into CO2 catalyzed by three rice-self-originating enzymes, i.e., glycolate oxidase, oxalate oxidase, and catalase. We successfully established this bypass in rice chloroplasts using a multi-gene assembly and transformation system. Transgenic rice plants carrying GOC bypass (GOC plants) showed significant increases in photosynthesis efficiency, biomass yield, and nitrogen content, as well as several other CO2-enriched phe no types under both greenhouse and field conditions .Grain yield of GOC plants varied depending on seeding season and was increased significantly in the spring. We further demonstrated that GOC plants had significant advantages under high-light conditions and that the improvements in GOC plants resulted primarily from a photosynthetic CO2-concentrating effect rather than from improved energy balance. Taken together, our results reveal that engineering a newly designed chloroplastic photorespiratory bypass could increase photosynthetic efficiency and yield of rice plants grown in field conditions, particularly under high light.展开更多
基金supported by the National Health Commission of the People’s Republic of China (201302002,Clinical Trial NCT02200679)。
文摘This study aimed to obtain the first national estimate of the prevalence of autism spectrum disorder(ASD) in Chinese children.We targeted the population of 6 to 12-year-old children for this prevalence study by multistage convenient cluster sampling.The Modified Chinese Autism Spectrum Rating Scale was used for the screening process.Of the target population of 142,086 children,88.5%(n=125,806) participated in the study.A total of 363 children were confirmed as having ASD.The observed ASD prevalence rate was 0.29%(95% CI:0.26%-0.32%) for the overall population.After adjustment for response rates,the estimated number of ASD cases was867 in the target population sample,thereby achieving an estimated prevalence of 0.70%(95% CI:0.64%-0.74%).The prevalence was significantly higher in boys than in girls(0.95%;95% CI:0.87%-1.02% versus 0.30%;95%CI:0.26%-0.34%;P <0.001).Of the 363 confirmed ASD cases,43.3% were newly diagnosed,and most of those(90.4%) were attending regular schools,and 68.8% of the children with ASD had at least one neuropsychiatric comorbidity.Our findings provide reliable data on the estimated ASD prevalence and comorbidities in Chinese children.
基金This work was financially supported by Grant No.81773341,82073458,81830096 from the National Natural Science Foundationthe Major Projects of International Cooperation and Exchanges NSFC Grant No.81620108024+1 种基金the Program of Introducing Talents of Discipline to Universities(111 Project,No.B20017)Scientific Research and Innovation Project of postgraduates in Hunan Province Grant No.1053320192834.
文摘Currently,pyroptosis has received more and more attention because of its association with innate immunity and disease.The research scope of pyroptosis has expanded with the discovery of the gasdermin family.A great deal of evidence shows that pyroptosis can affect the development of tumors.The relationship between pyroptosis and tumors is diverse in different tissues and genetic backgrounds.In this review,we provide basic knowledge of pyroptosis,explain the relationship between pyroptosis and tumors,and focus on the significance of pyroptosis in tumor treatment.In addition,we further summarize the possibility of pyroptosis as a potential tumor treatment strategy and describe the side effects of radiotherapy and chemotherapy caused by pyroptosis.In brief,pyroptosis is a double-edged sword for tumors.The rational use of this dual effect will help us further explore the formation and development of tumors,and provide ideas for patients to develop new drugs based on pyroptosis.
文摘Background： Atopic dermatitis （AD） is an inflammatory skin disease characterized by chronic recurrent dermatitis with profound itching. Most patients have personal and/or family history of atopic diseases. Several criteria have been proposed for the diagnosis of AD. Although the clinical features of childhood AD have been widely studied, there has been less large-scale study on adult/adolescent AD. The aim of this study was to investigate the clinical features of adult/adolescent patients with chronic symmetrical eczemaJAD and to propose Chinese diagnostic criteria for adult/adolescent AD. Methods： A hospital-based study was performed. Forty-two dermatological centers participated in this study. Adult and adolescent patients （12 years and over） with chronic symmetrical eczema or AD were included in this study. Questionnaires were completed by both patients and-investigators. The valid questionnaires were analyzed using EpiData 3.1 and SPSS 17.0 software. Results： A total of 2662 valid questionnaires were collected （1369 male and 1293 female）. Of all 2662 patients, 2062 （77.5%） patients had the disease after 12 years old, while only 600 （22.5%） patients had the disease before 12 years old, suggesting late-onset eczema/AD is common. Two thousand one hundred and thirty-nine （80.4%） patients had the disease for more than 6 months. One thousand one hundred and forty-four （43.0%） patients had a personal and/or family history of atopic diseases. One thousand five hundred and forty-eight （58.2%） patients had an elevated total serum IgE and/or eosinophilia and/or positive allergen-specific IgE. Based on these clinical and laboratory features, we proposed Chinese criteria for adult/adolescent AD. Of all 2662 patients, 60.3% were satisfied with our criteria, while only 48.2% satisfied with Hanifin Rajka criteria and 32.7% satisfied with Williams criteria, suggesting a good sensitivity of our criteria in adult/adolescent AD patients. Conclusion： Late-onset of eczema or AD is common. Th
文摘Dear Editor Salvia miltiorrhiza Bunge （Danshen） is a medicinal plant of the Lamiaceae family, and its dried roots have long been used in traditional Chinese medicine with hydrophilic phenolic acids and tanshinones as pharmaceutically active components （Zhang et al., 2014; Xu et al., 2016）. The first step of tanshinone biosynthesis is bicyclization of the general diterpene precursor （E,E,E）-geranylgeranyl diphosphate （GGPP） to copalyl diphosphate （CPP） by CPP synthases （CPSs）, which is followed by a cyclization or rearrangement reaction catalyzed by kaurene synthase-like enzymes （KSL）. The resulting intermediate is usually an olefin, which requires the insertion of oxygen by cytochrome P450 mono-oxygenases （CYPs） for the final production of diterpenoids （Zi et al., 2014）. While the CPS, KSL, and several early acting CYPs （CYP76AH1, CYP76AH3, and CYP76AK1） for tanshinone biosynthesis have been identified in S. miltiorrhiza （Gao et al., 2009; Guo et al., 2013, 2016; Zi and Peters, 2013）, the majority of the overall biosynthetic pathway, as well as the relevant regulatory factors associated with tanshinone production, remains elusive （Figure 1B）.
基金supported by the National Natural Science Foundation of China,No.81672171(to XY),81330042(to SQF),81620108018(to SQF),81772342the State Key Laboratory of Medicinal Chemical Biology(Nankai University),China,No.2017027
文摘Ferroptosis is an iron-dependent novel cell death pathway. Deferoxamine, a ferroptosis inhibitor, has been reported to promote spinal cord injury repair. It has yet to be clarified whether ferroptosis inhibition represents the mechanism of action of Deferoxamine on spinal cord injury recovery. A rat model of Deferoxamine at thoracic 10 segment was established using a modified Allen's method. Ninety 8-week-old female Wistar rats were used. Rats in the Deferoxamine group were intraperitoneally injected with 100 mg/kg Deferoxamine 30 minutes before injury. Simultaneously, the Sham and Deferoxamine groups served as controls. Drug administration was conducted for 7 consecutive days. The results were as follows:(1) Electron microscopy revealed shrunken mitochondria in the spinal cord injury group.(2) The Basso, Beattie and Bresnahan locomotor rating score showed that recovery of the hindlimb was remarkably better in the Deferoxamine group than in the spinal cord injury group.(3) The iron concentration was lower in the Deferoxamine group than in the spinal cord injury group after injury.(4) Western blot assay revealed that, compared with the spinal cord injury group, GPX4, xCT, and glutathione expression was markedly increased in the Deferoxamine group.(5) Real-time polymerase chain reaction revealed that, compared with the Deferoxamine group, mRNA levels of ferroptosis-related genes Acyl-CoA synthetase family member 2(ACSF2) and iron-responsive element-binding protein 2(IREB2) were up-regulated in the Deferoxamine group.(6) Deferoxamine increased survival of neurons and inhibited gliosis. These findings confirm that Deferoxamine can repair spinal cord injury by inhibiting ferroptosis. Targeting ferroptosis is therefore a promising therapeutic approach for spinal cord injury.
基金This study is supported by the offshore NGH production test projects under the Marine Geological Survey Program initiated by the China Geological Survey(DD20190226,DD20190218)the Major Program of National Natural Science Foundation of China(41730528,51991365)。
文摘Clayey silt reservoirs bearing natural gas hydrates(NGH)are considered to be the hydrate-bearing reservoirs that boast the highest reserves but tend to be the most difficult to exploit.They are proved to be exploitable by the first NGH production test conducted in the South China Sea in 2017.Based on the understanding of the first production test,the China Geological Survey determined the optimal target NGH reservoirs for production test and conducted a detailed assessment,numerical and experimental simulation,and onshore testing of the reservoirs.After that,it conducted the second offshore NGH production test in 1225 m deep Shenhu Area,South China Sea(also referred to as the second production test)from October 2019 to April 2020.During the second production test,a series of technical challenges of drilling horizontal wells in shallow soft strata in deep sea were met,including wellhead stability,directional drilling of a horizontal well,reservoir stimulation and sand control,and accurate depressurization.As a result,30 days of continuous gas production was achieved,with a cumulative gas production of 86.14×104 m3.Thus,the average daily gas production is 2.87×10^4 m^3,which is 5.57 times as much as that obtained in the first production test.Therefore,both the cumulative gas production and the daily gas production were highly improved compared to the first production test.As indicated by the monitoring results of the second production test,there was no anomaly in methane content in the seafloor,seawater,and atmosphere throughout the whole production test.This successful production test further indicates that safe and effective NGH exploitation is feasible in clayey silt NGH reservoirs.The industrialization of hydrates consists of five stages in general,namely theoretical research and simulation experiments,exploratory production test,experimental production test,productive production test,and commercial production.The second production test serves as an important step from the exploratory production test to exper
基金Supported by the National Natural Science Foundation of China
文摘The New Vacuum Solar Telescope （NVST） is a one meter vacuum solar telescope that aims to observe fine structures on the Sun. The main goals of NVST are high resolution imaging and spectral observations, including measurements of the solar magnetic field. NVST is the primary ground-based facility used by the Chinese solar research community in this solar cycle. It is located by Fuxian Lake in southwest China, where the seeing is good enough to perform high resolution observations. We first introduce the general conditions at the Fuxian Solar Observatory and the primary science cases of NVST. Then, the basic structures of this telescope and instruments are described in detail. Finally, some typical high resolution data of the solar photosphere and chromosphere are also shown.
基金supported by the National Science Foundation of China(61571117,61522106,61138001,61302018 and 61401089)Natural Science Foundation of the Jiangsu Province(BK2012019)the 111 Project(111-2-05).
文摘Metamaterials based on effective media can be used to produce a number of unusual physical properties(for example,negative refraction and invisibility cloaking)because they can be tailored with effective medium parameters that do not occur in nature.Recently,the use of coding metamaterials has been suggested for the control of electromagnetic waves through the design of coding sequences using digital elements‘0’and‘1,'which possess opposite phase responses.Here we propose the concept of an anisotropic coding metamaterial in which the coding behaviors in different directions are dependent on the polarization status of the electromagnetic waves.We experimentally demonstrate an ultrathin and flexible polarization-controlled anisotropic coding metasurface that functions in the terahertz regime using specially designed coding elements.By encoding the elements with elaborately designed coding sequences(both 1-bit and 2-bit sequences),the x-and y-polarized waves can be anomalously reflected or independently diffused in three dimensions.The simulated far-field scattering patterns and near-field distributions are presented to illustrate the dual-functional performance of the encoded metasurface,and the results are consistent with the measured results.We further demonstrate the ability of the anisotropic coding metasurfaces to generate a beam splitter and realize simultaneous anomalous reflections and polarization conversions,thus providing powerful control of differently polarized electromagnetic waves.The proposed method enables versatile beam behaviors under orthogonal polarizations using a single metasurface and has the potential for use in the development of interesting terahertz devices.
文摘The Large Sky Area Multi-Object Fiber Spectroscopic Telescope (LAMOST, also called the Guo Shou Jing Telescope) is a special reflecting Schmidt telescope. LAMOST’s special design allows both a large aperture (effective aperture of 3.6 m–4.9 m) and a wide field of view (FOV) (5°). It has an innovative active reflecting Schmidt configuration which continuously changes the mirror’s surface that adjusts during the observation process and combines thin deformable mirror active optics with segmented active optics. Its primary mirror (6.67m×6.05 m) and active Schmidt mirror (5.74m×4.40 m) are both segmented, and composed of 37 and 24 hexagonal sub-mirrors respectively. By using a parallel controllable fiber positioning technique, the focal surface of 1.75 m in diameter can accommodate 4000 optical fibers. Also, LAMOST has 16 spectrographs with 32 CCD cameras. LAMOST will be the telescope with the highest rate of spectral acquisition. As a national large scientific project, the LAMOST project was formally proposed in 1996, and approved by the Chinese government in 1997. The construction started in 2001, was completed in 2008 and passed the official acceptance in June 2009. The LAMOST pilot survey was started in October 2011 and the spectroscopic survey will launch in September 2012. Up to now, LAMOST has released more than 480 000 spectra of objects. LAMOST will make an important contribution to the study of the large-scale structure of the Universe, structure and evolution of the Galaxy, and cross-identification of multiwaveband properties in celestial objects.
基金the National Natural Science Foundation of China (31470343, 31770256)the Science and Technology Project of Guangzhou City (201607020006).
文摘Over the past few years, three photorespiratory bypasses have been introduced into plants, two of which led to observable in creases in photos yn thesis and biomass yield. However, most of the experiments were carried out using Arabidopsis under controlled environmental conditions, and the increases were only observed under low-light and short-day conditions. In this study, we designed a new photorespiratory bypass (called GOC bypass), characterized by no reducing equivalents being produced during a complete oxidation of glycolate into CO2 catalyzed by three rice-self-originating enzymes, i.e., glycolate oxidase, oxalate oxidase, and catalase. We successfully established this bypass in rice chloroplasts using a multi-gene assembly and transformation system. Transgenic rice plants carrying GOC bypass (GOC plants) showed significant increases in photosynthesis efficiency, biomass yield, and nitrogen content, as well as several other CO2-enriched phe no types under both greenhouse and field conditions .Grain yield of GOC plants varied depending on seeding season and was increased significantly in the spring. We further demonstrated that GOC plants had significant advantages under high-light conditions and that the improvements in GOC plants resulted primarily from a photosynthetic CO2-concentrating effect rather than from improved energy balance. Taken together, our results reveal that engineering a newly designed chloroplastic photorespiratory bypass could increase photosynthetic efficiency and yield of rice plants grown in field conditions, particularly under high light.
