The"4+4"Medical Doctor(MD)Pilot Program at PUMC:Implementation,Performance,and Prospects

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.

Estimation of Incidence of Herpes Zoster in Three Cities of China,2019-2020

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).

The importance of aboveground and belowground interspecific interactions in determining crop growth and advantages of peanut/maize intercropping

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.

Astronomical time scale of the Turonian constrained by multiple paleoclimate proxies

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.

Hydrothermal synthesis and enhanced photocatalytic activity of hierarchical flower-like Fe-doped BiVO_4

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.

MiR-25-3p attenuates the proliferation of tongue squamous cell carcinoma cell line Tca8113

Objective:To investigate the effects of miR-25-3p on the occurrence,development and proliferation of tongue squamous cell carcinoma cells.Methods:To establish tongue squamous cell carcinoma cell line Tca8113 that stably and highly express miR-25-3p using recombinant reiroviral vector-mediated gene transfer method.The proliferation of transfected Tca8113 was detected by thiazolyl blue tetrazolium bromide(MTT)and cell colony formation assays.eyclnD1,p21^(cipt)and p27^(kipt)mRNA expressions in the transfected Tca-8113 were detected by quantitative PCR.cyclinD1,p21^(cipt),p27^(kipt),AKT,p-AKT,FOXOt and p-FOX01 expressions in the transfected Tca8113 were detected by western blot analysis.In addition,miR-25-3p expression in the tongue squamous cell carcinoma cell line and tissue specimen was also detected by quantitative PCR.Results:Quantitative PCR showed that mitt-25-3p expression in the tongue squamous cell carcinoma cell lines and tissue specimen was significantly lower than that in the adjacent tissue.MTT and cell colony formation assays showed that after miR-25-3p overexpression,the proliferation of transfected Tca8113 was obviously attenuated.Western blot analysis and quantitative PCR showed that after miR-25-3p overexpression.p21^(cipt)and p27^(kipt)expressions were upregulated,while cyclinD1,AKT,FOXO1 expressions were downregulated,and AKT and FOXO1 phosphorylation was inactivated in the transfected Tca8113 cells.Conclusions:MiR-25-3p inhibited the proliferation of tongue squamous cell carcinoma cells and regulated cell cycle-related protein expression,playing an important role in the occurrence and development of squamous cell carcinoma of the tongue.

Auxin response and transport during induction of pedicel abscission in tomato

Auxin plays a central role in control of organ abscission,and it is thought that changes in the auxin gradient across the abscission zone are the primary determinant of the onset of abscission.The nature of this gradient,whether in concentration,flow,or perhaps in the response system has not conclusively been determined.We employed a DR5::GUS auxin response reporter system to examine the temporal and spatial distribution of the auxin response activity in response to developmental and environmental cues during pedicel abscission in tomato.In pedicels of young and fully open flowers,auxin response,as indicated by GUS activity,was predominantly detected in the vascular tissues and was almost entirely confined to the abscission zone(AZ)and to the distal portion of the pedicel,with a striking reduction in the proximal tissues below the AZ-a‘step’,rather than a gradient.Following pollination and during early fruit development,auxin response increased substantially throughout the pedicel.Changes in GUS activity following treatments that caused pedicel abscission(flower removal,high temperature,darkness,ethylene,or N-1-naphthylphthalamic acid(NPA)treatment)were relatively minor,with reduced auxin response in the AZ and some reduction above and below it.Expression of genes encoding some auxin efflux carriers(PIN)and influx carriers(AUX⁄LAX)was substantially reduced in the abscission zone of NPA-treated pedicels,and in pedicels stimulated to abscise by flower removal.Our results suggest that changes in auxin flow distribution through the abscission zone are likely more important than the auxin response system in the regulation of abscission.

Correg-Yolov3:a Method for Dense Buildings Detection in High-resolution Remote Sensing Images

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.

The Tomato Hybrid Proline-rich Protein regulates the abscission zone competence to respond to ethylene signals

The Tomato Hybrid Proline-rich Protein(THyPRP)gene was specifically expressed in the tomato(Solanum lycopersicum)flower abscission zone(FAZ),and its stable antisense silencing under the control of an abscission zone(AZ)-specific promoter,Tomato Abscission Polygalacturonase4,significantly inhibited tomato pedicel abscission following flower removal.For understanding the THyPRP role in regulating pedicel abscission,a transcriptomic analysis of the FAZ of THyPRP-silenced plants was performed,using a newly developed AZ-specific tomato microarray chip.Decreased expression of THyPRP in the silenced plants was already observed before abscission induction,resulting in FAZ-specific altered gene expression of transcription factors,epigenetic modifiers,post-translational regulators,and transporters.Our data demonstrate that the effect of THyPRP silencing on pedicel abscission was not mediated by its effect on auxin balance,but by decreased ethylene biosynthesis and response.Additionally,THyPRP silencing revealed new players,which were demonstrated for the first time to be involved in regulating pedicel abscission processes.These include:gibberellin perception,Ca2+-Calmodulin signaling,Serpins and Small Ubiquitin-related Modifier proteins involved in post-translational modifications,Synthaxin and SNARE-like proteins,which participate in exocytosis,a process necessary for cell separation.These changes,occurring in the silenced plants early after flower removal,inhibited and/or delayed the acquisition of the competence of the FAZ cells to respond to ethylene signaling.Our results suggest that THyPRP acts as a master regulator of flower abscission in tomato,predominantly by playing a role in the regulation of the FAZ cell competence to respond to ethylene signals.

Small-sized cuprous oxide species on silica boost acrolein formation via selective oxidation of propylene

Oxide-supported copper-containing materials have attracted considerable research attention as promising candidates for acrolein formation.Nevertheless,the elucidation of the structure-performance relationships for these systems remains a scientific challenge.In this work,copper oxide clusters deposited on a high-surface-area silica support were synthesized via a deposition-precipitation approach and exhibited remarkable catalytic reactivity(up to 25.5%conversion and 66.8%selectivity)in the propylene-selective oxidation of acrolein at 300℃.Aberration-corrected high-angle annular dark-field scanning transmission electron microscopy combined with X-ray absorption fine structure measurements of the catalyst before and after the reaction confirmed the transformation of the small-sized copper oxide(CuO)clusters into cuprous oxide(Cu2O)clusters.With the aid of in situ X-ray diffraction and in situ dual beam Fourier transform infrared spectroscopy(DB-FTIR),the allyl intermediate(CH2=CHCH2*)was clearly observed,along with the as-formed Cu2O species.The intermediate can react with oxygen atoms from neighboring Cu2O species to form acrolein during the catalytic process,and the small-sized Cu2O clusters play a crucial role in the generation of acrolein via the selective oxidation of propylene.

Robust Formation Maneuvers Through Sliding Mode for Multi-agent Systems With Uncertainties

This paper develops a robust control method for formation maneuvers of a multi-agent system. The multi-agent system is leader-follower-based, where the graph theory is utilized to describe the information exchange among the agents. The control method is exercised via sliding mode methodology where each agent is subjected to uncertainties. The technique of nonlinear disturbance observer is adopted in order to overcome the adverse effects of the uncertainties. Assuming that the uncertainties have an unknown bound, the formation stability conditions are investigated according to a given communication topology. In the sense of Lyapunov, not only the formation maneuvers of the multi-agent system have guaranteed stability, but the desired formations of the agents are also realized. Compared with other two control approaches, i.e., the basic sliding mode approach and the fuzzy sliding mode approach, some numerical results are presented to illustrate the effectiveness, performance and validity of the robust control method for formation maneuvers in the presence of uncertainties.

CFD-Based Numerical Analysis of the Thermal Characteristics of an Electric Vehicle Power Battery

Towards the end to solve the problem of temperature rise in the power battery of electric vehicles,a method based on the coupling of electrochemical,thermal and hydrodynamic aspects is implemented.The method relies on the COMSOL Multiphysics software,which is used here to simulate the thermal behaviour,the related fluid-dynamics and the life attenuation of the power battery.A 3D battery model is built assuming a cylindrical geometry.The diameter of the battery is 18 mm,and its length is 65 mm.The battery charges and discharges at 3C,and the initial temperature is 25°C.Intake flow is set to 0.5 m/s after the air of the battery is cooled.The results show that:(1)The highest temperature of the battery unit increases significantly from 1.14°C of the original nylon heat pipe to 0.17°C of the hot pipe core shaft;(2)When the short circuit of the battery is simulated,the temperature rise of the single battery is close to 20°C,the minimum rise is about 12°C,and their difference reaches 8°C.

Tea Polyphenols Reduce Inflammation of Orbital Fibroblasts in Graves’Ophthalmopathy via the NF-κB/NLRP3 Pathway

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.

Genetic variation in GmCRP contributes to nodulation in soybean(Glycine max Merr.)

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.

A review of manufacturing technologies for silicon carbide superjunction devices

Superjunction technology is believed to reach the optimal specific on-resistance and breakdown voltage trade-off.It has become a mainstream technology in silicon high-voltage metal oxide semiconductor field effect transistor devices.Numerous efforts have been conducted to employ the same concept in silicon carbide devices.These works are summarized here.

Comparisons of Image Quality and ADCs in Breath-Hold, Respiratory-Triggered and Free-Breathing DWI of Pancreas at 3-T

Objective: To compare image quality and apparent diffusion coefficients (ADC) of the normal pancreas parenchymas in breath-hold, respiratory-triggered and free-breathing diffusion weighted imaging (DWI) at 3.0-Tesla. Methods: DWI of the pancreas was performed at 3.0-Tesla in 21 healthy volunteers with breath-hold, respiratory-triggered and free-breathing using b-values of 0 and 500 s/mm2. For all three sequences, two readers assigned an image quality score to images at b0 and b500, and two independent readers measured ADCs for the head, body and tail of pancreas. Image quality scores and ADCs of pancreas in the three DWIs were compared. Results: For b0, image quality scores was not significantly different among the three sequences (p = 0.103). For b500, image quality score was significantly lower in free-breathing DWI than breath-hold or respiratory-triggered DWI (p = 0.000), and not significantly different between breath-hold and respiratory-triggered DWI (p = 0.212). Mean ADCs differed significantly among the anatomical regions with the lowest values measured in the pancreatic tail both at breath-hold and respiratory-triggered DWIs whereas no significant difference was found at free-breathing DWI. Conclusion: Breath-hold or respiratory-triggered technique provided DW images of pancreas with acceptable quality at 3.0-Tesla. Breath-hold is the preferred DWI technique for ADC measurements of pancreas.

Seismic performance analysis of underground structures based on random field model of soil mechanical parameters

Soils with spatial variability are the product of natural history.The mechanical properties tested by soil samples from boreholes in the same soil layer may be different.Underground structure service in surrounding soils,their seismic response is controlled by the deformation of the surrounding soils.The variability of soil mechanical parameters was not considered in the current research on the seismic response of underground structures.Therefore,a random field model was established to describe the spatial variability of surrounding soils based on the random field theory.Then the seismic response of underground structures in the random field was simulated based on the time-domain explicit global FEM analysis,and the soil mechanical parameters and earthquake intensity influencing the seismic response of surrounding soils and underground structures were studied.Numerical results presented that,the randomness of soil parameters does not change the plastic deformation mode of surrounding soils significantly.The variation coefficients of inter-story deformation of structures and lateral deformation of columns are much smaller than that of mechanical parameters,and the randomness of soil parameters has no obvious effect on the structural deformation response.

Comparative Test on New Small Watermelon Varieties with Red Flesh under Soilless Culture Conditions

In order to screen out the small watermelon varieties with red flesh suitable for soilless cultivation and to meet people's requirements of high-quality watermelons,comparative tests were conducted on 6 small watermelon varieties with red flesh under soilless culture conditions in 2018.Based on the data of field traits,yield traits,quality traits and commercial traits,the integrated results showed that ‘Chuanqi 2’ had good quality and high yield,and the overall performance was the best.

A high-order scheme based on lattice Boltzmann flux solver for viscous compressible flow simulations

In this paper,a high-order scheme based on the lattice Boltzmann flux solver(LBFS)is proposed to simulate viscous compressible flows.The flux reconstruction(FR)approach is adopted to implement the spatial discretization.The LBFS is employed to compute the inviscid flux by using the local reconstruction of the lattice Boltzmann equation solutions from macroscopic flow variables.Meanwhile,a switch function is used in LBFS to adjust the magnitude of the numerical viscosity.Thus,it is more beneficial to capture both strong shock waves and thin boundary layers.Moreover,the viscous flux is computed according to the local discontinuous Galerkin method.Some typical compressible viscous problems,including manufactured solution case,lid-driven cavity flow,supersonic flow around a cylinder and subsonic flow over a NACA0012 airfoil,are simulated to demonstrate the accuracy and robustness of the proposed FR-LBFS.

Zircon classification from cathodoluminescence images using deep learning

Zircon is a widely-used heavy mineral in geochronological and geochemical research because it can extract important information to understand the history and genesis of rocks. Zircon has various types,and an accurate examination of zircon type is a prerequisite procedure before further analysis.Cathodoluminescence(CL) imaging is one of the most reliable ways to classify zircons. However, current CL image examination is conducted by manual work, which is time-consuming, bias-prone, and requires expertise. An automated and bias-free method for zircon classification is absent but necessary. To this end, deep convolutional neural networks(DCNNs) and transfer learning are applied in this study to classify the common types of zircons, i.e., igneous, metamorphic, and hydrothermal zircons. An atlas with over 4000 CL images of these three types of zircons is created, and three DCNNs are trained using these images. The results of this study indicate that the DCNNs can distinguish hydrothermal zircons from other zircons, as indicated by the highest accuracy of 100%. Although similar textures in igneous and metamorphic zircons pose great challenges for zircon classification, the DCNNs successfully classify 95% igneous and 92% metamorphic zircons. This study demonstrates the high accuracy of DCNNs in zircon classification and presents the great potentiality of deep learning techniques in numerous geoscientific disciplines.