Herpes zoster(HZ)is a painful condition resulting from reactivation of dormant varicella-zoster virus(VZV)in a previously VZV-infected person[1].Typical clinical manifestation of HZ are unilateral radicular pain and a...Herpes zoster(HZ)is a painful condition resulting from reactivation of dormant varicella-zoster virus(VZV)in a previously VZV-infected person[1].Typical clinical manifestation of HZ are unilateral radicular pain and a vesicular rash limited to one side of the body in the distribution of a nerve[2].The most common complication of HZ postherpetic neuralgia(PHN).展开更多
Peking Union Medical College(PUMC)launched the"4+4"Medical Doctor(MD)pilot program in 2018,admitting students with non-medical backgrounds from top universities,aligning with national medical talent training...Peking Union Medical College(PUMC)launched the"4+4"Medical Doctor(MD)pilot program in 2018,admitting students with non-medical backgrounds from top universities,aligning with national medical talent training policies to foster diverse and eager learners in medicine.On the occasion of the graduation of the first class of the"4+4"MD pilot class at PUMC in 2023,we reviewed the teaching reform in the pilot program and carried out a systematic survey and interviews with students,faculties,and management staff of the pilot class.This article reports on the measures taken by the pilot class at PUMC in enrollment and curriculum setting,and demonstrates the achievements of the pilot class in terms of student academic background structure,knowledge acquisition and skill learning,scientific research ability,and course evaluation.The results indicated that the pilot class had met the national demand for the"Medicine+X"talent training model.More specifically,with a diverse academic backgrounds,the pilot class graduates had academic levels comparable to the eight-year medical education graduates,and their scientific research abilities were satisfactory.The pilot program at PUMC will optimize the curriculum setting,strengthen the construction of faculty,learning resources,and teaching facilities,and reform the academic evaluation methods,thus deepening the reform of medical education and improving the"4+4"MD program as a novel medical education model.展开更多
The exploration of building detection plays an important role in urban planning,smart city and military.Aiming at the problem of high overlapping ratio of detection frames for dense building detection in high resoluti...The exploration of building detection plays an important role in urban planning,smart city and military.Aiming at the problem of high overlapping ratio of detection frames for dense building detection in high resolution remote sensing images,we present an effective YOLOv3 framework,corner regression-based YOLOv3(Correg-YOLOv3),to localize dense building accurately.This improved YOLOv3 algorithm establishes a vertex regression mechanism and an additional loss item about building vertex offsets relative to the center point of bounding box.By extending output dimensions,the trained model is able to output the rectangular bounding boxes and the building vertices meanwhile.Finally,we evaluate the performance of the Correg-YOLOv3 on our self-produced data set and provide a comparative analysis qualitatively and quantitatively.The experimental results achieve high performance in precision(96.45%),recall rate(95.75%),F1 score(96.10%)and average precision(98.05%),which were 2.73%,5.4%,4.1%and 4.73%higher than that of YOLOv3.Therefore,our proposed algorithm effectively tackles the problem of dense building detection in high resolution images.展开更多
Objective:This study aimed to explore the effects of tea polyphenols(TP)on inflammation of orbital fibroblasts in Graves’ophthalmopathy(GO)and to provide new ideas for GO treatment.Methods:Primary orbital fibroblasts...Objective:This study aimed to explore the effects of tea polyphenols(TP)on inflammation of orbital fibroblasts in Graves’ophthalmopathy(GO)and to provide new ideas for GO treatment.Methods:Primary orbital fibroblasts were extracted from orbital adipose/connective tissues of patients with and without GO.Real-time quantitative PCR(RT-qPCR)was used to detect the expression of interleukin(IL)-6,IL-1β,and monocyte chemotactic protein(MCP)-1 in non-GO and GO orbital fibroblasts.The CCK-8 assay was used to determine the appropriate concentration of TP for subsequent experiments.RT-qPCR and enzyme-linked immunosorbent assay(ELISA)were performed to investigate the effects of TP on lipopolysaccharide(LPS)-induced production of inflammatory cytokines.Nuclear factor-κB(NF-κB)expression was measured using Western blotting analysis.NOD-like receptor 3(NLRP3)expression was detected using both Western blotting analysis and immunofluorescence staining.Results:The mRNA levels of IL-6,IL-1β,and MCP-1 in GO orbital fibroblasts were significantly higher than those in non-GO cells.TP treatment significantly inhibited LPS-induced production of inflammatory factors,including IL-6,IL-1β,and MCP-1.TP also inhibited the expression levels of NF-κB and NLRP3.Inflammation in the GO orbital fibroblasts was higher than that in non-GO cells.TP inhibited the production of inflammatory cytokines in GO orbital fibroblasts in vitro through the NF-κB/NLRP3 pathway.Conclusion:These findings suggest that TP may have a potential role in GO treatment.展开更多
Symbiosis between soybean and rhizobia contributes to soybean yield and quality. Although secreted rhizobial type Ⅲ effectors are known to regulate infection and promote nitrogen fixation, much about them remains unk...Symbiosis between soybean and rhizobia contributes to soybean yield and quality. Although secreted rhizobial type Ⅲ effectors are known to regulate infection and promote nitrogen fixation, much about them remains unknown. Mutation of NopC, a type Ⅲ effector from Sinorhizobium fredii HH103, reduced nodule numbers and dry weights in 310 soybean accessions, and expression of NopC in soybean hairy roots promoted symbiosis. Based on observed differences in nodule traits between Suinong 14 and Zyd 00,006inoculated with HH103 and the NopC mutant, 11 QTL associated with rhizobia were identified in chromosome segment substitution lines(CSSLs) derived from Suinong 14 and Zyd 00006. Using chromosome fragment insertion, whole-genome sequencing of Suinong 14 and Zyd 00006, and qRT-PCR,Glyma.19G176300(GmCRP) was identified as a candidate gene associated with NopC, and GmCRP was found to be induced by NopC to positively regulate nodulation. SNPs located in the regulatory regions of GmCRP influenced its expression response to NopC, with SNPs contributing to nodulation having been selected during domestication. Our findings reveal the function of a soybean gene encoding a rhizobial type Ⅲ effector that contributes to symbiosis, and will facilitate the practical application of symbiotic nitrogen fixation in molecular breeding.展开更多
The Litang fault(LTF),located in the southeast of the Qinghai-Tibetan Plateau,is known for its high level of present-day seismicity,whereas its Pleistocene activity has been scarcely documented.This study focused on a...The Litang fault(LTF),located in the southeast of the Qinghai-Tibetan Plateau,is known for its high level of present-day seismicity,whereas its Pleistocene activity has been scarcely documented.This study focused on a tract of banded travertine deposits precipitated from thermal waters along the NW–SE-trending LTF trace.The role of travertine deposits in recording neotectonic activity has been studied by identifying their internal structure.Typical soft-sediment deformation structures observed within the banded travertines include micro folds,liquefied breccia,and liquefied diapirs.These deformed structures,which are restricted to a single unit separated unconformably by undeformed layers,can be traced for tens of meters,indicating that they were formed by seismic shaking triggered by LTF activity.The deformation of the banded travertine layers is attributed to the combined effects of seismic shaking,liquefaction,and fluidization,and it can be related to a paleo earthquake event with a magnitude of MS>5.The U-series ages obtained from the banded travertine deposits perturbed by the earthquakes are in the range of 130.59–112.94 ka,indicating an important fault-assisted neotectonic activity that occurred during the Middle–Late Pleistocene.Analysis of such structures,in combination with the use of U-series dating methods,can yield a reliable timing of neotectonic activity and provide new evidence for under-standing the seismotectonic setting of the Litang area.展开更多
[Objectives]This study was conducted to select small seedless watermelon varieties with excellent quality and high yield suitable for planting in Beijing.[Methods]Under the conditions of facility cultivation in Beijin...[Objectives]This study was conducted to select small seedless watermelon varieties with excellent quality and high yield suitable for planting in Beijing.[Methods]Under the conditions of facility cultivation in Beijing,a screening test was conducted on seven small seedless watermelon varieties for growth process,field traits,yield traits,fruit quality,and disease resistance.[Results]Varieties Mitong,Motong and Tianbao Xiaowuzi had a short growth period and relatively stable growth,and bore fruit easily,and their female flowers were closely spaced.Their yields exceeded 60000 kg/hm~2,ranking in the top three among all varieties.The fruit had a thin skin,a bright red flesh color,and a high mass fraction of soluble solids in the center.The flesh was tight or crispy,and tasted good.They also showed good disease resistance.Overall,they showed excellent comprehensive agronomic traits,and are thus suitable for facility cultivation in Beijing and its surrounding areas.[Conclusions]This study provides a theoretical basis for the upgrading of varieties and the increase in production and farmers'income in the suburbs of Beijing.展开更多
[Objectives]The paper was to explore the effects of different concentrations of paclobutrazol on seedling quality of small seedless watermelon in autumn.[Methods]The leaves of watermelon seedlings were sprayed with 30...[Objectives]The paper was to explore the effects of different concentrations of paclobutrazol on seedling quality of small seedless watermelon in autumn.[Methods]The leaves of watermelon seedlings were sprayed with 30,50,80 and 120 mg/L paclobutrazol at cotyledon expansion stage,and those sprayed with tap water were used as control.[Results]All the treatments of paclobutrazol effectively inhibited the excessive growth of watermelon at seedling stage,significantly enhanced the leaf quality of watermelon seedlings and promoted root growth.The seedlings treated by 50 mg/L paclobutrazol had the best performance compared with the control:a decrease of hypocotyl by 37.9%,an increase of plant dry weight by 46.55%,significantly increased seedling strength index,deep green leaf color,thick leaves,an increase of specific leaf weight by 28.13%,and significantly heavier root weight and longer length.[Conclusions]The results will provide a reference for strong seedling cultivation of small seedless watermelon.展开更多
[Objectives]To compare the effects of molecular distillation on the flavor and antitumor activity of Ganoderma lucidum spore oil.[Methods]G.lucidum spore oil was separated and purified by molecular distillation techno...[Objectives]To compare the effects of molecular distillation on the flavor and antitumor activity of Ganoderma lucidum spore oil.[Methods]G.lucidum spore oil was separated and purified by molecular distillation technology,and the volatile components of different components of molecular distillation were analyzed by gas chromatography-ion mobility spectrometry(GC-IMS)technology.Human liver carcinoma cells(HepG2),human breast cancer cells(MCF-7),and human cervical cancer cells(Hela)were selected as the tumor cell lines to be tested,and the cell viability was detected by the MTT assay.[Results]Molecular distillation effectively reduced small molecular substances produced by oil oxidation in G.lucidum spore oil,such as heptanal,octanal,linalool,hexanal,E-2-octanal,3-ethylpyridine,etc.Among the heavy components,the content of esters was relatively high,mainly including ethyl levulinate,ethyl crotonate,and amyl butyrate.The MTT cytotoxicity test indicated that G.lucidum spore oil and its molecular distillation components had certain inhibitory effects on the growth of three tumor cells,and G.lucidum spore oil crude oil had the most significant antitumor activity.G.lucidum spore oil crude oil,heavy component,and light component had the most significant antitumor activity on HepG2 cells,followed by MCF-7 cells,and the weakest antitumor activity on Hela cells.The quality of G.lucidum spore oil became higher after molecular distillation,and the rancid smell was reduced,and molecular distillation had little effect on the antitumor activity of G.lucidum spores.[Conclusions]Molecular distillation technology can be applied to the refining of G.lucidum spore oil to improve product quality.展开更多
Thermo-responsive nanocomposites have recently emerged as potential nanoplugging agents for shale stabilization in high-temperature water-based drilling fluids(WBDFs). However, their inhibitory properties have not bee...Thermo-responsive nanocomposites have recently emerged as potential nanoplugging agents for shale stabilization in high-temperature water-based drilling fluids(WBDFs). However, their inhibitory properties have not been very effective in high-temperature drilling operations. Thermo-responsive Janus nanocomposites are expected to strongly interact with clay particles from the inward hemisphere of nanomaterials, which drive the establishment of a tighter hydrophobic membrane over the shale surface at the outward hemisphere under geothermal conditions for shale stabilization. This work combines the synergistic benefits of thermo-responsive and zwitterionic nanomaterials to synchronously enhance the chemical inhibitions and plugging performances in shale under harsh conditions. A novel thermoresponsive Janus nanosilica(TRJS) exhibiting zwitterionic character was synthesized, characterized,and assessed as shale stabilizer for WBDFs at high temperatures. Compared to pristine nanosilica(Si NP)and symmetrical thermo-responsive nanosilica(TRS), TRJS exhibited anti-polyelectrolyte behaviour, in which electrolyte ions screened the electrostatic attraction between the charged particles, potentially stabilizing nanomaterial in hostile shaly environments(i.e., up to saturated brine or API brine). Macroscopically, TRJS exhibited higher chemical inhibition than Si NP and TRS in brine, prompting a better capability to control pressure penetration. TRJS adsorbed onto the clay surface via chemisorption and hydrogen bonding, and the interactions became substantial in brine, according to the results of electrophoretic mobility, surface wettability, and X-ray diffraction. Thus, contributing to the firm trapping of TRJS into the nanopore structure of the shale, triggering the formation of a tight hydrophobic membrane over the shale surface from the outward hemisphere. The addition of TRJS into WBDF had no deleterious effect on fluid properties after hot-treatment at 190℃, implying that TRJS could find potential use as a shale stabilizer in WBDFs in hostile environments.展开更多
Convolutional neural networks(CNNs) exhibit excellent performance in the areas of image recognition and object detection, which can enhance the intelligence level of spacecraft. However, in aerospace, energetic partic...Convolutional neural networks(CNNs) exhibit excellent performance in the areas of image recognition and object detection, which can enhance the intelligence level of spacecraft. However, in aerospace, energetic particles, such as heavy ions, protons, and alpha particles, can induce single event effects(SEEs) that lead CNNs to malfunction and can significantly impact the reliability of a CNN system. In this paper, the MNIST CNN system was constructed based on a 28 nm systemon-chip(SoC), and then an alpha particle irradiation experiment and fault injection were applied to evaluate the SEE of the CNN system. Various types of soft errors in the CNN system have been detected, and the SEE cross sections have been calculated. Furthermore, the mechanisms behind some soft errors have been explained. This research will provide technical support for the design of radiation-resistant artificial intelligence chips.展开更多
Federated learning enables data owners in the Internet of Things(IoT)to collaborate in training models without sharing private data,creating new business opportunities for building a data market.However,in practical o...Federated learning enables data owners in the Internet of Things(IoT)to collaborate in training models without sharing private data,creating new business opportunities for building a data market.However,in practical operation,there are still some problems with federated learning applications.Blockchain has the characteristics of decentralization,distribution,and security.The blockchain-enabled federated learning further improve the security and performance of model training,while also expanding the application scope of federated learning.Blockchain has natural financial attributes that help establish a federated learning data market.However,the data of federated learning tasks may be distributed across a large number of resource-constrained IoT devices,which have different computing,communication,and storage resources,and the data quality of each device may also vary.Therefore,how to effectively select the clients with the data required for federated learning task is a research hotspot.In this paper,a two-stage client selection scheme for blockchain-enabled federated learning is proposed,which first selects clients that satisfy federated learning task through attribute-based encryption,protecting the attribute privacy of clients.Then blockchain nodes select some clients for local model aggregation by proximal policy optimization algorithm.Experiments show that the model performance of our two-stage client selection scheme is higher than that of other client selection algorithms when some clients are offline and the data quality is poor.展开更多
AIM:To compare the safety and clinical outcomes of subconjunctival trypsin and dexamethasone(DEX)injections in the treatment of anterior chamber fibrin exudates in eyes with globe rupture following primary wound repai...AIM:To compare the safety and clinical outcomes of subconjunctival trypsin and dexamethasone(DEX)injections in the treatment of anterior chamber fibrin exudates in eyes with globe rupture following primary wound repair and vitrectomy.METHODS:A retrospective analysis included 42 males and 10 females(mean age 46.0±6.0y,range 34 to 58y)who underwent primary wound sutures and vitrectomy for globe rupture.Patients with pupil-covered fibrinous exudate or/and membrane in the anterior chamber were treated.On the first postoperative day,subconjunctival injections of either 5000 units(0.4 mL)of trypsin solution(n=25)or 0.5 mL(1 mg)DEX(n=27)were administered to accelerate exudate absorption.Efficacy was assessed by observing break time and partial absorption of the fibrin exudate membrane.Safety and comfort were evaluated by monitoring intraocular pressure(IOP),allergy,pain,and foreign body sensation.RESULTS:Both groups achieved 1/3 absorption of the anterior chamber fibrin exudate membrane,but the trypsin group exhibited shorter break time and partial absorption time compared to the DEX group(P<0.05).Trypsin treatment was also less irritating to patients.No adverse reactions were reported,and IOP remained stable.Visual acuity improved in both groups without statistical difference.CONCLUSION:Compared to DEX,trypsin demonstrates a shorter absorption time for the fibrin exudate membrane with a more comfortable process in treating pupil-covered fibrinous exudate or/and membrane after vitrectomy for globe rupture.展开更多
BACKGROUND Some hydatid cysts of cystic echinococcosis type 1(CE1)lack well-defined cyst walls or distinctive endocysts,making them difficult to differentiate from simple hepatic cysts.AIM To investigate the diagnosti...BACKGROUND Some hydatid cysts of cystic echinococcosis type 1(CE1)lack well-defined cyst walls or distinctive endocysts,making them difficult to differentiate from simple hepatic cysts.AIM To investigate the diagnostic methods for atypical hepatic CE1 and the clinical efficacy of laparoscopic surgeries.METHODS The clinical data of 93 patients who had a history of visiting endemic areas of CE and were diagnosed with cystic liver lesions for the first time at the People's Hospital of Xinjiang Uygur Autonomous Region(China)from January 2018 to September 2023 were retrospectively analyzed.Clinical diagnoses were made based on findings from serum immunoglobulin tests for echinococcosis,routine abdominal ultrasound,high-frequency ultrasound,abdominal computed tomography(CT)scan,and laparoscopy.Subsequent to the treatments,these patients underwent reexaminations at the outpatient clinic until October 2023.The evaluations included the diagnostic precision of diverse examinations,the efficacy of surgical approaches,and the incidence of CE recurrence.RESULTS All 93 patients were diagnosed with simple hepatic cysts by conventional abdominal ultrasound and abdominal CT scan.Among them,16 patients were preoperatively diagnosed with atypical CE1,and 77 were diagnosed with simple hepatic cysts by high-frequency ultrasound.All the 16 patients preoperatively diagnosed with atypical CE1 underwent laparoscopy,of whom 14 patients were intraoperatively confirmed to have CE1,which was consistent with the postoperative pathological diagnosis,one patient was diagnosed with a mesothelial cyst of the liver,and the other was diagnosed with a hepatic cyst combined with local infection.Among the 77 patients who were preoperatively diagnosed with simple hepatic cysts,4 received aspiration sclerotherapy of hepatic cysts,and 19 received laparoscopic fenestration.These patients were intraoperatively diagnosed with simple hepatic cysts.During the followup period,none of the 14 patients with CE1 experienced recurrence or implantation of hydatid scolices.One of the 77 patients was finally confirmed to have CE complicated with implantation to the right intercostal space.CONCLUSION Abdominal high-frequency ultrasound can detect CE1 hydatid cysts.The laparoscopic technique serves as a more effective diagnostic and therapeutic tool for CE.展开更多
In this study,a novel residential virtual power plant(RVPP)scheduling method that leverages a gate recurrent unit(GRU)-integrated deep reinforcement learning(DRL)algorithm is proposed.In the proposed scheme,the GRU-in...In this study,a novel residential virtual power plant(RVPP)scheduling method that leverages a gate recurrent unit(GRU)-integrated deep reinforcement learning(DRL)algorithm is proposed.In the proposed scheme,the GRU-integrated DRL algorithm guides the RVPP to participate effectively in both the day-ahead and real-time markets,lowering the electricity purchase costs and consumption risks for end-users.The Lagrangian relaxation technique is introduced to transform the constrained Markov decision process(CMDP)into an unconstrained optimization problem,which guarantees that the constraints are strictly satisfied without determining the penalty coefficients.Furthermore,to enhance the scalability of the constrained soft actor-critic(CSAC)-based RVPP scheduling approach,a fully distributed scheduling architecture was designed to enable plug-and-play in the residential distributed energy resources(RDER).Case studies performed on the constructed RVPP scenario validated the performance of the proposed methodology in enhancing the responsiveness of the RDER to power tariffs,balancing the supply and demand of the power grid,and ensuring customer comfort.展开更多
Doped HfO_(2)-based ferroelectric(FE)films are emerging as leading contenders for next-generation FE nonvolatile memories due to their excellent compatibility with complementary metal oxide semiconductor processes and...Doped HfO_(2)-based ferroelectric(FE)films are emerging as leading contenders for next-generation FE nonvolatile memories due to their excellent compatibility with complementary metal oxide semiconductor processes and robust ferroelectricity at nanoscale dimensions.Despite the considerable attention paid to the FE properties of HfO_(2)-based films in recent years,enhancing their polarization switching speed remains a critical research challenge.We demonstrate the strong ferroelectricity of sub-10nm Hf_(0.5)Zr_(0.5)O_(2)(HZO)thin films and show that the polarization switching speed of these thin films can be significantly affected by HZO thickness and anisotropically strained La_(0.67)Sr_(0.33)MO_(3)-buffered layer.Our observations indicate that the HZO thin film thickness and anisotropically strained La_(0.67)Sr_(0.33)MO_(3)layer influence the nucleation of reverse domains by altering the phase composition of the HZO thin film,thereby reducing the polarization switching time.Although the increase in HZO thickness and anisotropic compressive strain hinder the formation of the FE phase,they can enable faster switching.Our findings suggest that FE HZO ultrathin films with polar orthorhombic structures have broad application prospects in microelectronic devices.These insights into novel methods for increasing polarization switching speed are poised to advance the development of high-performance FE devices.展开更多
Intercropping of maize(Zea mays L.) and peanut(Arachis hypogaea L.) often results in greater yields than the respective sole crops. However, there is limited knowledge of aboveground and belowground interspecific inte...Intercropping of maize(Zea mays L.) and peanut(Arachis hypogaea L.) often results in greater yields than the respective sole crops. However, there is limited knowledge of aboveground and belowground interspecific interactions between maize and peanut in field. A two-year field experiment was conducted to investigate the effects of interspecific interactions on plant growth and grain yield for a peanut/maize intercropping system under different nitrogen(N) and phosphorus(P) levels. The method of root separation was employed to differentiate belowground from aboveground interspecific interactions. We observed that the global interspecific interaction effect on the shoot biomass of the intercropping system decreased with the coexistence period, and belowground interaction contributed more than aboveground interaction to advantages of the intercropping in terms of shoot biomass and grain yield. There was a positive effect from aboveground and belowground interspecific interactions on crop plant growth in the intercropping system, except that aboveground interaction had a negative effect on peanut during the late coexistence period. The advantage of intercropping on grain came mainly from increased maize yield(means 95%) due to aboveground interspecific competition for light and belowground interaction(61%–72% vs. 28%–39% in fertilizer treatments). There was a negative effect on grain yield from aboveground interaction for peanut, but belowground interspecific interaction positively affected peanut grain yield.The supply of N, P, or N + P increased grain yield of intercropped maize and the contribution from aboveground interspecific interaction. Our study suggests that the advantages of peanut/maize intercropping for yield mainly comes from aboveground interspecific competition for maize and belowground interspecific facilitation for peanut, and their respective yield can be enhanced by N and P. These findings are important for managing the intercropping system and optimizing the benefits from using this system.展开更多
One of the clocks that record the Earth history is(quasi-) periodic astronomical cycles.These cycles influence the climate that can be ultimately stored in sedimentary rocks.By cracking these(quasi-) periodic sediment...One of the clocks that record the Earth history is(quasi-) periodic astronomical cycles.These cycles influence the climate that can be ultimately stored in sedimentary rocks.By cracking these(quasi-) periodic sedimentation signals,high resolution astronomical time scale(ATS) can be obtained.Paleoclimate proxies are widely used to extract astronomical cycles.However different proxies may respond differently to astronomical signals and nonastronomical noises including tectonics,diagenesis,and measurement error among others.Astronomical time scale constructed based on a single proxy where its signal-to-noise ratio is low may have uncertainty that is difficult to evaluate but can be revealed by utilizing other proxies.Here,we test eight astronomical age models using two astrochro no logical methods from four paleoclimate proxies(i.e.,color reflection L~* and b~*,natural gamma radiation,and bulk density) from the Turonian to the Coniacian of the Cretaceous Period at the Demerara Rise in the equatorial Atlantic.The two astrochronological methods are time calibration using long eccentricity bandpass filtering(E1 bandpass) and tracking the long eccentricity from evolutive harmonic analysis(tracking EHA).The statistical mean and standard deviation of four age models from the four proxies are calculated to construct one integrated age model with age uncertainty in each method.Results demonstrate that extracting astronomical signals from multiple paleoclimate proxies is a valid method to estimate age model uncertainties.Anchored at the Cenomanian/Turonian boundary with an age of 93.9 ± 0.15 Ma from biostratigraphy,the ages for CC11/CC12(calcareous nannofossil zones),Turonian/Coniacian(CC12/CC13),CC13/CC14,and Coniacian/Santonian boundaries are 91.25±0.20 Ma,89.87±0.20 Ma,86.36±0.33 Ma,and 86.03±0.32 Ma in E1 bandpass method,compared with 91.17±0.36 Ma,89.74±0.38 Ma,86.13±1.31 Ma,and 85.80±1.33 Ma respectively in tracking EHA method.These results are consistent with previous studies within error and provide a reliable estimation of uncertainties of the ages.展开更多
Fe-doped BiVO4with hierarchical flower-like structure was prepared via a hydrothermal method using sodium dodecylbenzene sulfonate(SDBS)as structure directing agent.X-ray diffraction(XRD),scanning electron microscope(...Fe-doped BiVO4with hierarchical flower-like structure was prepared via a hydrothermal method using sodium dodecylbenzene sulfonate(SDBS)as structure directing agent.X-ray diffraction(XRD),scanning electron microscope(SEM),transmissionelectron microscope(TEM),high resolution transmission electron microscope(HRTEM),X-ray photoelectron spectroscopy(XPS)and UV-Vis were applied for characterization of the as-prepared samples.The formation mechanism of flower-like structure wasproposed based on the evolution of morphology as a function of hydrothermal time.Fe-doped into substitutional sites of BiVO4effectively improved the migration and separation of photogenerated carrier and enhanced the utilization of visible light.Flower-likeFe-doped BiVO4showed much higher visible-light-driven photocatalytic efficiency for degradation of methyl blue compared withthe pristine BiVO4.And the sample with a Fe/Bi mole ratio of2.5%showed the highest photocatalytic efficiency.展开更多
基金supported by the Operation of Public Health Emergency Response Mechanism of the Chinese Center for Disease Control and Prevention(10239322002001,0000017)Research on Vaccine Evaluation Strategy and capacity Building Project(09207).
文摘Herpes zoster(HZ)is a painful condition resulting from reactivation of dormant varicella-zoster virus(VZV)in a previously VZV-infected person[1].Typical clinical manifestation of HZ are unilateral radicular pain and a vesicular rash limited to one side of the body in the distribution of a nerve[2].The most common complication of HZ postherpetic neuralgia(PHN).
文摘Peking Union Medical College(PUMC)launched the"4+4"Medical Doctor(MD)pilot program in 2018,admitting students with non-medical backgrounds from top universities,aligning with national medical talent training policies to foster diverse and eager learners in medicine.On the occasion of the graduation of the first class of the"4+4"MD pilot class at PUMC in 2023,we reviewed the teaching reform in the pilot program and carried out a systematic survey and interviews with students,faculties,and management staff of the pilot class.This article reports on the measures taken by the pilot class at PUMC in enrollment and curriculum setting,and demonstrates the achievements of the pilot class in terms of student academic background structure,knowledge acquisition and skill learning,scientific research ability,and course evaluation.The results indicated that the pilot class had met the national demand for the"Medicine+X"talent training model.More specifically,with a diverse academic backgrounds,the pilot class graduates had academic levels comparable to the eight-year medical education graduates,and their scientific research abilities were satisfactory.The pilot program at PUMC will optimize the curriculum setting,strengthen the construction of faculty,learning resources,and teaching facilities,and reform the academic evaluation methods,thus deepening the reform of medical education and improving the"4+4"MD program as a novel medical education model.
基金National Natural Science Foundation of China(No.41871305)National Key Research and Development Program of China(No.2017YFC0602204)+2 种基金Fundamental Research Funds for the Central Universities,China University of Geosciences(Wuhan)(No.CUGQY1945)Open Fund of Key Laboratory of Geological Survey and Evaluation of Ministry of Education and the Fundamental Research Funds for the Central Universities(No.GLAB2019ZR02)Open Fund of Laboratory of Urban Land Resources Monitoring and Simulation,Ministry of Natural Resources,China(No.KF-2020-05-068)。
文摘The exploration of building detection plays an important role in urban planning,smart city and military.Aiming at the problem of high overlapping ratio of detection frames for dense building detection in high resolution remote sensing images,we present an effective YOLOv3 framework,corner regression-based YOLOv3(Correg-YOLOv3),to localize dense building accurately.This improved YOLOv3 algorithm establishes a vertex regression mechanism and an additional loss item about building vertex offsets relative to the center point of bounding box.By extending output dimensions,the trained model is able to output the rectangular bounding boxes and the building vertices meanwhile.Finally,we evaluate the performance of the Correg-YOLOv3 on our self-produced data set and provide a comparative analysis qualitatively and quantitatively.The experimental results achieve high performance in precision(96.45%),recall rate(95.75%),F1 score(96.10%)and average precision(98.05%),which were 2.73%,5.4%,4.1%and 4.73%higher than that of YOLOv3.Therefore,our proposed algorithm effectively tackles the problem of dense building detection in high resolution images.
基金supported by the National Natural Science Foundation of China(No.82160206 and No.81360152),the Natural Science Foundation of Guangxi Province(No.2018GXNSFAA281234),2019 Guangxi One Thousand Young and Middle-Aged College and University Backbone Teachers Cultivation Program and“Medical Excellence Award”Funded by the Creative Research Development Grant from the First Affiliated Hospital of Guangxi Medical University.
文摘Objective:This study aimed to explore the effects of tea polyphenols(TP)on inflammation of orbital fibroblasts in Graves’ophthalmopathy(GO)and to provide new ideas for GO treatment.Methods:Primary orbital fibroblasts were extracted from orbital adipose/connective tissues of patients with and without GO.Real-time quantitative PCR(RT-qPCR)was used to detect the expression of interleukin(IL)-6,IL-1β,and monocyte chemotactic protein(MCP)-1 in non-GO and GO orbital fibroblasts.The CCK-8 assay was used to determine the appropriate concentration of TP for subsequent experiments.RT-qPCR and enzyme-linked immunosorbent assay(ELISA)were performed to investigate the effects of TP on lipopolysaccharide(LPS)-induced production of inflammatory cytokines.Nuclear factor-κB(NF-κB)expression was measured using Western blotting analysis.NOD-like receptor 3(NLRP3)expression was detected using both Western blotting analysis and immunofluorescence staining.Results:The mRNA levels of IL-6,IL-1β,and MCP-1 in GO orbital fibroblasts were significantly higher than those in non-GO cells.TP treatment significantly inhibited LPS-induced production of inflammatory factors,including IL-6,IL-1β,and MCP-1.TP also inhibited the expression levels of NF-κB and NLRP3.Inflammation in the GO orbital fibroblasts was higher than that in non-GO cells.TP inhibited the production of inflammatory cytokines in GO orbital fibroblasts in vitro through the NF-κB/NLRP3 pathway.Conclusion:These findings suggest that TP may have a potential role in GO treatment.
基金supported by the China Postdoctoral Science Foundation(2020M681072)the National Natural Science Foundation of China(32072014,U20A2027,and 31771882)‘Hundred-thousand and million project of Heilongjiang province for engineering and technology science’soybean breeding technology innovation and new cultivar breeding(2019ZX16B01).
文摘Symbiosis between soybean and rhizobia contributes to soybean yield and quality. Although secreted rhizobial type Ⅲ effectors are known to regulate infection and promote nitrogen fixation, much about them remains unknown. Mutation of NopC, a type Ⅲ effector from Sinorhizobium fredii HH103, reduced nodule numbers and dry weights in 310 soybean accessions, and expression of NopC in soybean hairy roots promoted symbiosis. Based on observed differences in nodule traits between Suinong 14 and Zyd 00,006inoculated with HH103 and the NopC mutant, 11 QTL associated with rhizobia were identified in chromosome segment substitution lines(CSSLs) derived from Suinong 14 and Zyd 00006. Using chromosome fragment insertion, whole-genome sequencing of Suinong 14 and Zyd 00006, and qRT-PCR,Glyma.19G176300(GmCRP) was identified as a candidate gene associated with NopC, and GmCRP was found to be induced by NopC to positively regulate nodulation. SNPs located in the regulatory regions of GmCRP influenced its expression response to NopC, with SNPs contributing to nodulation having been selected during domestication. Our findings reveal the function of a soybean gene encoding a rhizobial type Ⅲ effector that contributes to symbiosis, and will facilitate the practical application of symbiotic nitrogen fixation in molecular breeding.
基金This work is supported financially by Spark Program of Earthquake Sciences,China Earthquake Administration(XH202301Y and XH23048C)State Key Laboratory of Earthquake Dynamics,Institute of Geology,CEA(LED2020B02)+1 种基金Lhasa National Geophysical Observation and Research Station(NORSLS21-04)Earthquake Science and Technology Special Project of Sichuan Earthquake Agency(LY2205 and LY2206).
文摘The Litang fault(LTF),located in the southeast of the Qinghai-Tibetan Plateau,is known for its high level of present-day seismicity,whereas its Pleistocene activity has been scarcely documented.This study focused on a tract of banded travertine deposits precipitated from thermal waters along the NW–SE-trending LTF trace.The role of travertine deposits in recording neotectonic activity has been studied by identifying their internal structure.Typical soft-sediment deformation structures observed within the banded travertines include micro folds,liquefied breccia,and liquefied diapirs.These deformed structures,which are restricted to a single unit separated unconformably by undeformed layers,can be traced for tens of meters,indicating that they were formed by seismic shaking triggered by LTF activity.The deformation of the banded travertine layers is attributed to the combined effects of seismic shaking,liquefaction,and fluidization,and it can be related to a paleo earthquake event with a magnitude of MS>5.The U-series ages obtained from the banded travertine deposits perturbed by the earthquakes are in the range of 130.59–112.94 ka,indicating an important fault-assisted neotectonic activity that occurred during the Middle–Late Pleistocene.Analysis of such structures,in combination with the use of U-series dating methods,can yield a reliable timing of neotectonic activity and provide new evidence for under-standing the seismotectonic setting of the Litang area.
基金Supported by Special Crop Innovation Team of Beijing(BAIC04-2022)。
文摘[Objectives]This study was conducted to select small seedless watermelon varieties with excellent quality and high yield suitable for planting in Beijing.[Methods]Under the conditions of facility cultivation in Beijing,a screening test was conducted on seven small seedless watermelon varieties for growth process,field traits,yield traits,fruit quality,and disease resistance.[Results]Varieties Mitong,Motong and Tianbao Xiaowuzi had a short growth period and relatively stable growth,and bore fruit easily,and their female flowers were closely spaced.Their yields exceeded 60000 kg/hm~2,ranking in the top three among all varieties.The fruit had a thin skin,a bright red flesh color,and a high mass fraction of soluble solids in the center.The flesh was tight or crispy,and tasted good.They also showed good disease resistance.Overall,they showed excellent comprehensive agronomic traits,and are thus suitable for facility cultivation in Beijing and its surrounding areas.[Conclusions]This study provides a theoretical basis for the upgrading of varieties and the increase in production and farmers'income in the suburbs of Beijing.
基金Beijing Innovation Consortium of Special Crops Research System(BAIC04-2022).
文摘[Objectives]The paper was to explore the effects of different concentrations of paclobutrazol on seedling quality of small seedless watermelon in autumn.[Methods]The leaves of watermelon seedlings were sprayed with 30,50,80 and 120 mg/L paclobutrazol at cotyledon expansion stage,and those sprayed with tap water were used as control.[Results]All the treatments of paclobutrazol effectively inhibited the excessive growth of watermelon at seedling stage,significantly enhanced the leaf quality of watermelon seedlings and promoted root growth.The seedlings treated by 50 mg/L paclobutrazol had the best performance compared with the control:a decrease of hypocotyl by 37.9%,an increase of plant dry weight by 46.55%,significantly increased seedling strength index,deep green leaf color,thick leaves,an increase of specific leaf weight by 28.13%,and significantly heavier root weight and longer length.[Conclusions]The results will provide a reference for strong seedling cultivation of small seedless watermelon.
基金Supported by Taishan Industrial Leading Talent Project(Efficient Ecological Agriculture Innovation)(LJNY202105)。
文摘[Objectives]To compare the effects of molecular distillation on the flavor and antitumor activity of Ganoderma lucidum spore oil.[Methods]G.lucidum spore oil was separated and purified by molecular distillation technology,and the volatile components of different components of molecular distillation were analyzed by gas chromatography-ion mobility spectrometry(GC-IMS)technology.Human liver carcinoma cells(HepG2),human breast cancer cells(MCF-7),and human cervical cancer cells(Hela)were selected as the tumor cell lines to be tested,and the cell viability was detected by the MTT assay.[Results]Molecular distillation effectively reduced small molecular substances produced by oil oxidation in G.lucidum spore oil,such as heptanal,octanal,linalool,hexanal,E-2-octanal,3-ethylpyridine,etc.Among the heavy components,the content of esters was relatively high,mainly including ethyl levulinate,ethyl crotonate,and amyl butyrate.The MTT cytotoxicity test indicated that G.lucidum spore oil and its molecular distillation components had certain inhibitory effects on the growth of three tumor cells,and G.lucidum spore oil crude oil had the most significant antitumor activity.G.lucidum spore oil crude oil,heavy component,and light component had the most significant antitumor activity on HepG2 cells,followed by MCF-7 cells,and the weakest antitumor activity on Hela cells.The quality of G.lucidum spore oil became higher after molecular distillation,and the rancid smell was reduced,and molecular distillation had little effect on the antitumor activity of G.lucidum spores.[Conclusions]Molecular distillation technology can be applied to the refining of G.lucidum spore oil to improve product quality.
基金financially supported by the National Natural Science Foundation of China(Grant No.52150410427)the Key Support Program for Foreign Experts of the Ministry of Science and Technology of the People's Republic of China(No.wgxz2022057)funding for post-doctoral work by the Department of Human Resources and Social Security of Hubei Province。
文摘Thermo-responsive nanocomposites have recently emerged as potential nanoplugging agents for shale stabilization in high-temperature water-based drilling fluids(WBDFs). However, their inhibitory properties have not been very effective in high-temperature drilling operations. Thermo-responsive Janus nanocomposites are expected to strongly interact with clay particles from the inward hemisphere of nanomaterials, which drive the establishment of a tighter hydrophobic membrane over the shale surface at the outward hemisphere under geothermal conditions for shale stabilization. This work combines the synergistic benefits of thermo-responsive and zwitterionic nanomaterials to synchronously enhance the chemical inhibitions and plugging performances in shale under harsh conditions. A novel thermoresponsive Janus nanosilica(TRJS) exhibiting zwitterionic character was synthesized, characterized,and assessed as shale stabilizer for WBDFs at high temperatures. Compared to pristine nanosilica(Si NP)and symmetrical thermo-responsive nanosilica(TRS), TRJS exhibited anti-polyelectrolyte behaviour, in which electrolyte ions screened the electrostatic attraction between the charged particles, potentially stabilizing nanomaterial in hostile shaly environments(i.e., up to saturated brine or API brine). Macroscopically, TRJS exhibited higher chemical inhibition than Si NP and TRS in brine, prompting a better capability to control pressure penetration. TRJS adsorbed onto the clay surface via chemisorption and hydrogen bonding, and the interactions became substantial in brine, according to the results of electrophoretic mobility, surface wettability, and X-ray diffraction. Thus, contributing to the firm trapping of TRJS into the nanopore structure of the shale, triggering the formation of a tight hydrophobic membrane over the shale surface from the outward hemisphere. The addition of TRJS into WBDF had no deleterious effect on fluid properties after hot-treatment at 190℃, implying that TRJS could find potential use as a shale stabilizer in WBDFs in hostile environments.
基金Project supported by the National Natural Science Foundation of China(Grant No.12305303)the Natural Science Foundation of Hunan Province of China(Grant Nos.2023JJ40520,2021JJ40444,and 2019JJ30019)+3 种基金the Research Foundation of Education Bureau of Hunan Province of China(Grant No.20A430)the Science and Technology Innovation Program of Hunan Province(Grant No.2020RC3054)the Natural Science Basic Research Plan in the Shaanxi Province of China(Grant No.2023-JC-QN-0015)the Doctoral Research Fund of University of South China。
文摘Convolutional neural networks(CNNs) exhibit excellent performance in the areas of image recognition and object detection, which can enhance the intelligence level of spacecraft. However, in aerospace, energetic particles, such as heavy ions, protons, and alpha particles, can induce single event effects(SEEs) that lead CNNs to malfunction and can significantly impact the reliability of a CNN system. In this paper, the MNIST CNN system was constructed based on a 28 nm systemon-chip(SoC), and then an alpha particle irradiation experiment and fault injection were applied to evaluate the SEE of the CNN system. Various types of soft errors in the CNN system have been detected, and the SEE cross sections have been calculated. Furthermore, the mechanisms behind some soft errors have been explained. This research will provide technical support for the design of radiation-resistant artificial intelligence chips.
文摘Federated learning enables data owners in the Internet of Things(IoT)to collaborate in training models without sharing private data,creating new business opportunities for building a data market.However,in practical operation,there are still some problems with federated learning applications.Blockchain has the characteristics of decentralization,distribution,and security.The blockchain-enabled federated learning further improve the security and performance of model training,while also expanding the application scope of federated learning.Blockchain has natural financial attributes that help establish a federated learning data market.However,the data of federated learning tasks may be distributed across a large number of resource-constrained IoT devices,which have different computing,communication,and storage resources,and the data quality of each device may also vary.Therefore,how to effectively select the clients with the data required for federated learning task is a research hotspot.In this paper,a two-stage client selection scheme for blockchain-enabled federated learning is proposed,which first selects clients that satisfy federated learning task through attribute-based encryption,protecting the attribute privacy of clients.Then blockchain nodes select some clients for local model aggregation by proximal policy optimization algorithm.Experiments show that the model performance of our two-stage client selection scheme is higher than that of other client selection algorithms when some clients are offline and the data quality is poor.
基金Supported by the Joint Construction Project of Henan Medical Science and Technology(No.LHGJ20220370)the Natural Science Foundation of Henan Province(No.232300420237).
文摘AIM:To compare the safety and clinical outcomes of subconjunctival trypsin and dexamethasone(DEX)injections in the treatment of anterior chamber fibrin exudates in eyes with globe rupture following primary wound repair and vitrectomy.METHODS:A retrospective analysis included 42 males and 10 females(mean age 46.0±6.0y,range 34 to 58y)who underwent primary wound sutures and vitrectomy for globe rupture.Patients with pupil-covered fibrinous exudate or/and membrane in the anterior chamber were treated.On the first postoperative day,subconjunctival injections of either 5000 units(0.4 mL)of trypsin solution(n=25)or 0.5 mL(1 mg)DEX(n=27)were administered to accelerate exudate absorption.Efficacy was assessed by observing break time and partial absorption of the fibrin exudate membrane.Safety and comfort were evaluated by monitoring intraocular pressure(IOP),allergy,pain,and foreign body sensation.RESULTS:Both groups achieved 1/3 absorption of the anterior chamber fibrin exudate membrane,but the trypsin group exhibited shorter break time and partial absorption time compared to the DEX group(P<0.05).Trypsin treatment was also less irritating to patients.No adverse reactions were reported,and IOP remained stable.Visual acuity improved in both groups without statistical difference.CONCLUSION:Compared to DEX,trypsin demonstrates a shorter absorption time for the fibrin exudate membrane with a more comfortable process in treating pupil-covered fibrinous exudate or/and membrane after vitrectomy for globe rupture.
文摘BACKGROUND Some hydatid cysts of cystic echinococcosis type 1(CE1)lack well-defined cyst walls or distinctive endocysts,making them difficult to differentiate from simple hepatic cysts.AIM To investigate the diagnostic methods for atypical hepatic CE1 and the clinical efficacy of laparoscopic surgeries.METHODS The clinical data of 93 patients who had a history of visiting endemic areas of CE and were diagnosed with cystic liver lesions for the first time at the People's Hospital of Xinjiang Uygur Autonomous Region(China)from January 2018 to September 2023 were retrospectively analyzed.Clinical diagnoses were made based on findings from serum immunoglobulin tests for echinococcosis,routine abdominal ultrasound,high-frequency ultrasound,abdominal computed tomography(CT)scan,and laparoscopy.Subsequent to the treatments,these patients underwent reexaminations at the outpatient clinic until October 2023.The evaluations included the diagnostic precision of diverse examinations,the efficacy of surgical approaches,and the incidence of CE recurrence.RESULTS All 93 patients were diagnosed with simple hepatic cysts by conventional abdominal ultrasound and abdominal CT scan.Among them,16 patients were preoperatively diagnosed with atypical CE1,and 77 were diagnosed with simple hepatic cysts by high-frequency ultrasound.All the 16 patients preoperatively diagnosed with atypical CE1 underwent laparoscopy,of whom 14 patients were intraoperatively confirmed to have CE1,which was consistent with the postoperative pathological diagnosis,one patient was diagnosed with a mesothelial cyst of the liver,and the other was diagnosed with a hepatic cyst combined with local infection.Among the 77 patients who were preoperatively diagnosed with simple hepatic cysts,4 received aspiration sclerotherapy of hepatic cysts,and 19 received laparoscopic fenestration.These patients were intraoperatively diagnosed with simple hepatic cysts.During the followup period,none of the 14 patients with CE1 experienced recurrence or implantation of hydatid scolices.One of the 77 patients was finally confirmed to have CE complicated with implantation to the right intercostal space.CONCLUSION Abdominal high-frequency ultrasound can detect CE1 hydatid cysts.The laparoscopic technique serves as a more effective diagnostic and therapeutic tool for CE.
基金supported by the Sichuan Science and Technology Program(grant number 2022YFG0123).
文摘In this study,a novel residential virtual power plant(RVPP)scheduling method that leverages a gate recurrent unit(GRU)-integrated deep reinforcement learning(DRL)algorithm is proposed.In the proposed scheme,the GRU-integrated DRL algorithm guides the RVPP to participate effectively in both the day-ahead and real-time markets,lowering the electricity purchase costs and consumption risks for end-users.The Lagrangian relaxation technique is introduced to transform the constrained Markov decision process(CMDP)into an unconstrained optimization problem,which guarantees that the constraints are strictly satisfied without determining the penalty coefficients.Furthermore,to enhance the scalability of the constrained soft actor-critic(CSAC)-based RVPP scheduling approach,a fully distributed scheduling architecture was designed to enable plug-and-play in the residential distributed energy resources(RDER).Case studies performed on the constructed RVPP scenario validated the performance of the proposed methodology in enhancing the responsiveness of the RDER to power tariffs,balancing the supply and demand of the power grid,and ensuring customer comfort.
基金supported by the National Key Research and Development Program of China(Grant Nos.2023YFA1406404 and 2020YFA0309100)the National Natural Science Foundation of China(Grant Nos.12074365,12374094,12304153,U2032218,and 11974326),the National Natural Science Foundation of China(Grant No.12274120)+4 种基金CAS Project for Young Scientists in Basic Research(Grant No.YSBR-084)the Fundamental Research Funds for the Central Universities(Grant Nos.WK9990000102 and WK2030000035)Anhui Provincial Natural Science Foundation(Grant No.2308085MA15)Hefei Science Center CAS Foundation(Grant Nos.2021HSC-CIP017 and 2016HSC-IU06)the China Postdoctoral Science Foundation(Grant No.2022M713060)。
文摘Doped HfO_(2)-based ferroelectric(FE)films are emerging as leading contenders for next-generation FE nonvolatile memories due to their excellent compatibility with complementary metal oxide semiconductor processes and robust ferroelectricity at nanoscale dimensions.Despite the considerable attention paid to the FE properties of HfO_(2)-based films in recent years,enhancing their polarization switching speed remains a critical research challenge.We demonstrate the strong ferroelectricity of sub-10nm Hf_(0.5)Zr_(0.5)O_(2)(HZO)thin films and show that the polarization switching speed of these thin films can be significantly affected by HZO thickness and anisotropically strained La_(0.67)Sr_(0.33)MO_(3)-buffered layer.Our observations indicate that the HZO thin film thickness and anisotropically strained La_(0.67)Sr_(0.33)MO_(3)layer influence the nucleation of reverse domains by altering the phase composition of the HZO thin film,thereby reducing the polarization switching time.Although the increase in HZO thickness and anisotropic compressive strain hinder the formation of the FE phase,they can enable faster switching.Our findings suggest that FE HZO ultrathin films with polar orthorhombic structures have broad application prospects in microelectronic devices.These insights into novel methods for increasing polarization switching speed are poised to advance the development of high-performance FE devices.
基金supported by the National Key Research and Development Program of China(2017YFD0200202)the National Natural Science Foundation of China(U1404315)+1 种基金the China Scholarship Council(201608410278)the Natural Science Foundation of Henan Province(182300410014)。
文摘Intercropping of maize(Zea mays L.) and peanut(Arachis hypogaea L.) often results in greater yields than the respective sole crops. However, there is limited knowledge of aboveground and belowground interspecific interactions between maize and peanut in field. A two-year field experiment was conducted to investigate the effects of interspecific interactions on plant growth and grain yield for a peanut/maize intercropping system under different nitrogen(N) and phosphorus(P) levels. The method of root separation was employed to differentiate belowground from aboveground interspecific interactions. We observed that the global interspecific interaction effect on the shoot biomass of the intercropping system decreased with the coexistence period, and belowground interaction contributed more than aboveground interaction to advantages of the intercropping in terms of shoot biomass and grain yield. There was a positive effect from aboveground and belowground interspecific interactions on crop plant growth in the intercropping system, except that aboveground interaction had a negative effect on peanut during the late coexistence period. The advantage of intercropping on grain came mainly from increased maize yield(means 95%) due to aboveground interspecific competition for light and belowground interaction(61%–72% vs. 28%–39% in fertilizer treatments). There was a negative effect on grain yield from aboveground interaction for peanut, but belowground interspecific interaction positively affected peanut grain yield.The supply of N, P, or N + P increased grain yield of intercropped maize and the contribution from aboveground interspecific interaction. Our study suggests that the advantages of peanut/maize intercropping for yield mainly comes from aboveground interspecific competition for maize and belowground interspecific facilitation for peanut, and their respective yield can be enhanced by N and P. These findings are important for managing the intercropping system and optimizing the benefits from using this system.
基金.This study was supported by NSF CAREERaward to Stephen R.Meyers (EAR-1151438)partially supported by the NSF Grant with No.1835717
文摘One of the clocks that record the Earth history is(quasi-) periodic astronomical cycles.These cycles influence the climate that can be ultimately stored in sedimentary rocks.By cracking these(quasi-) periodic sedimentation signals,high resolution astronomical time scale(ATS) can be obtained.Paleoclimate proxies are widely used to extract astronomical cycles.However different proxies may respond differently to astronomical signals and nonastronomical noises including tectonics,diagenesis,and measurement error among others.Astronomical time scale constructed based on a single proxy where its signal-to-noise ratio is low may have uncertainty that is difficult to evaluate but can be revealed by utilizing other proxies.Here,we test eight astronomical age models using two astrochro no logical methods from four paleoclimate proxies(i.e.,color reflection L~* and b~*,natural gamma radiation,and bulk density) from the Turonian to the Coniacian of the Cretaceous Period at the Demerara Rise in the equatorial Atlantic.The two astrochronological methods are time calibration using long eccentricity bandpass filtering(E1 bandpass) and tracking the long eccentricity from evolutive harmonic analysis(tracking EHA).The statistical mean and standard deviation of four age models from the four proxies are calculated to construct one integrated age model with age uncertainty in each method.Results demonstrate that extracting astronomical signals from multiple paleoclimate proxies is a valid method to estimate age model uncertainties.Anchored at the Cenomanian/Turonian boundary with an age of 93.9 ± 0.15 Ma from biostratigraphy,the ages for CC11/CC12(calcareous nannofossil zones),Turonian/Coniacian(CC12/CC13),CC13/CC14,and Coniacian/Santonian boundaries are 91.25±0.20 Ma,89.87±0.20 Ma,86.36±0.33 Ma,and 86.03±0.32 Ma in E1 bandpass method,compared with 91.17±0.36 Ma,89.74±0.38 Ma,86.13±1.31 Ma,and 85.80±1.33 Ma respectively in tracking EHA method.These results are consistent with previous studies within error and provide a reliable estimation of uncertainties of the ages.
基金Project(51102025)supported by the National Natural Science Foundation of ChinaProject(14JJ7040)supported by Natural Science Foundation of Hunan Province,ChinaProject(2014GH561172)supported by China Torch Program
文摘Fe-doped BiVO4with hierarchical flower-like structure was prepared via a hydrothermal method using sodium dodecylbenzene sulfonate(SDBS)as structure directing agent.X-ray diffraction(XRD),scanning electron microscope(SEM),transmissionelectron microscope(TEM),high resolution transmission electron microscope(HRTEM),X-ray photoelectron spectroscopy(XPS)and UV-Vis were applied for characterization of the as-prepared samples.The formation mechanism of flower-like structure wasproposed based on the evolution of morphology as a function of hydrothermal time.Fe-doped into substitutional sites of BiVO4effectively improved the migration and separation of photogenerated carrier and enhanced the utilization of visible light.Flower-likeFe-doped BiVO4showed much higher visible-light-driven photocatalytic efficiency for degradation of methyl blue compared withthe pristine BiVO4.And the sample with a Fe/Bi mole ratio of2.5%showed the highest photocatalytic efficiency.