Enhanced High-Temperature Energy Storage Performance of All-Organic Composite Dielectric via Constructing Fiber-Re in forced Structure

Optimizing the high-temperature energy storage characteristics of energy storage dielectrics is of great significance for the development of pulsed power devices and power control systems.Selecting a polymer with a higher glass transition temperature(T_(g))as the matrix is one of the effective ways to increase the upper limit of the polymer operating temperature.However,current high-T_(g)polymers have limitations,and it is difficult to meet the demand for high-temperature energy storage dielectrics with only one polymer.For example,polyetherimide has high-energy storage efficiency,but low breakdown strength at high temperatures.Polyimide has high corona resistance,but low high-temperature energy storage efficiency.In this work,combining the advantages of two polymer,a novel high-T_(g)polymer fiber-reinforced microstructure is designed.Polyimide is designed as extremely fine fibers distributed in the composite dielectric,which will facilitate the reduction of high-temperature conductivity loss for polyimide.At the same time,due to the high-temperature resistance and corona resistance of polyimide,the high-temperature breakdown strength of the composite dielectric is enhanced.After the polyimide content with the best high-temperature energy storage characteristics is determined,molecular semiconductors(ITIC)are blended into the polyimide fibers to further improve the high-temperature efficiency.Ultimately,excellent high-temperature energy storage properties are obtained.The 0.25 vol%ITIC-polyimide/polyetherimide composite exhibits high-energy density and high discharge efficiency at 150℃(2.9 J cm^(-3),90%)and 180℃(2.16 J cm^(-3),90%).This work provides a scalable design idea for high-performance all-organic high-temperature energy storage dielectrics.

基于石墨涂层传热技术制备界面冶金结合泡沫铝夹芯板

提出一种通过石墨涂敷处理(GCT)泡沫铝夹芯板(AFS)前驱体来提高其在粉末冶金发泡过程中传热效率的新方法。研究不同传热方法的升温和膨胀特征以及对泡孔结构和抗弯性能的影响。结果表明,前驱体在采用GCT后,升温速度增加近2倍,这提高了AFS的膨胀率、改善了泡孔尺寸均匀性和外部面板形态。此外,在发泡后期阶段具有更加平稳的升温速率,这有助于提高泡孔圆度,并减少泡壁内微孔缺陷。这些改变使AFS的弯曲强度和吸能性能得以显著提高。值得注意的是,因为热传递速率不受板幅尺寸的影响,GCT技术在大尺寸AFS的生产中具有巨大潜力。

Low-temperature replacement construction of three-dimensional corrosion-resistant interface for deeply rechargeable Zn metal batteries

Aqueous Zn batteries are promising candidates for grid-scale renewable energy storage.Foil electrodes have been widely investigated and applied as anode materials for aqueous Zn batteries,however,they suffer from limited surface area and severe interfacial issues including metallic dendrites and corrosion side reactions,limiting the depth of discharge(DOD)of the foil electrode materials.Herein,a low-temperature replacement reaction is utilized to in-situ construct a three-dimensional(3D)corrosion-resistant interface for deeply rechargeable Zn foil electrodes.Specifically,the deliberate low-temperature environment controlled the replacement rate between polycrystalline Zn metal and oxalic acid,producing a Zn foil electrode with distinct 3D corrosion-resistant interface(3DCI-Zn),which differed from conventional two-dimensional(2D)protective structure and showed an order of magnitude higher surface area.Consequently,the 3DCI-Zn electrode exhibited dendrite-free and anticorrosion properties,and achieved stable plating/stripping performance for 1000 h at 10 mA cm^(-2)and 10 mAh cm^(-2)with a remarkable DOD of 79%.After pairing with a MnO2cathode with a high areal capacity of 4.2 mAh cm^(-2),the pouch cells delivered 168 Wh L^(-1)and a capacity retention of 89.7%after 100 cycles with a low negative/positive(N/P)ratio of 3:1.

Complex role of neutrophils in the tumor microenvironment: an avenue for novel immunotherapies

Neutrophils,which originate from the bone marrow and are characterized by a segmented nucleus and a brief lifespan,have a crucial role in the body’s defense against infections and acute inflammation.Recent research has uncovered the complex roles of neutrophils as regulators in tumorigenesis,during which neutrophils exhibit a dualistic nature that promotes or inhibits tumor progression.This adaptability is pivotal within the tumor microenvironment(TME).In this review,we provide a comprehensive characterization of neutrophil plasticity and heterogeneity,aiming to illuminate current research findings and discuss potential therapeutic avenues.By delineating the intricate interplay of neutrophils in the TME,this review further underscores the urgent need to understand the dual functions of neutrophils with particular emphasis on the anti-tumor effects to facilitate the development of effective therapeutic strategies against cancer.

A compact X-band backward traveling-wave accelerating structure

Very high-energy electrons(VHEEs)are potential candidates for FLASH radiotherapy for deep-seated tumors.We proposed a compact VHEE facility based on an X-band high-gradient high-power technique.In this study,we investigated and realized the first X-band backward traveling-wave(BTW)accelerating structure as the buncher for a VHEE facility.A method for calculating the parameters of single cell from the field distribution was introduced to simplify the design of the BTW structure.Time-domain circuit equations were applied to calculate the transient beam parameters of the buncher in the unsteady state.A prototype of the BTW structure with a thermionic cathode-diode electron gun was designed,fabricated,and tested at high power at the Tsinghua X-band high-power test stand.The structure successfully operated with 5-MW microwave pulses from the pulse compressor and outputted electron bunches with an energy of 8 MeV and a pulsed current of 108 mA.

Two Distinct Charge Orders in Infinite-Layer PrNiO_(2+δ) Revealed by Resonant X-Ray Diffraction

Research of infinite-layer nickelates has unveiled a broken translation symmetry,which has sparked significant interest in its root,its relationship to superconductivity,and its comparison to charge order in cuprates.In this study,resonant x-ray scattering measurements were performed on thin films of infinite-layer PrNiO_(2+δ).The results show significant differences in the superlattice reflection at the Ni L_(3) absorption edge compared to that at the Pr M_(5) resonance in their dependence on energy,temperature,and local symmetry.These differences point to two distinct charge orders,although they share the same in-plane wavevectors.It is suggested that these dissimilarities could be linked to the excess oxygen dopants,given that the resonant reflections were observed in an incompletely reduced PrNiO_(2+δ)film.Furthermore,azimuthal analysis indicates that the oxygen ligands likely play a crucial role in the charge modulation revealed at the Ni L_(3) resonance.

Trading in Fast-ChangingMarkets withMeta-Reinforcement Learning

How to find an effective trading policy is still an open question mainly due to the nonlinear and non-stationary dynamics in a financial market.Deep reinforcement learning,which has recently been used to develop trading strategies by automatically extracting complex features from a large amount of data,is struggling to deal with fastchanging markets due to sample inefficiency.This paper applies the meta-reinforcement learning method to tackle the trading challenges faced by conventional reinforcement learning(RL)approaches in non-stationary markets for the first time.In our work,the history trading data is divided into multiple task data and for each of these data themarket condition is relatively stationary.Then amodel agnosticmeta-learning(MAML)-based tradingmethod involving a meta-learner and a normal learner is proposed.A trading policy is learned by the meta-learner across multiple task data,which is then fine-tuned by the normal learner through a small amount of data from a new market task before trading in it.To improve the adaptability of the MAML-based method,an ordered multiplestep updating mechanism is also proposed to explore the changing dynamic within a task market.The simulation results demonstrate that the proposed MAML-based trading methods can increase the annualized return rate by approximately 180%,200%,and 160%,increase the Sharpe ratio by 180%,90%,and 170%,and decrease the maximum drawdown by 30%,20%,and 40%,compared to the traditional RL approach in three stock index future markets,respectively.

分析化学“课程思政”重构的思考和教改探索

为落实各类课程都要与思想政治理论课同向同行,形成协同效应的高校教育新模式,开展了分析化学课程的思政重构研究和教学探索。分析化学课程自身具有显著的可实验验证特性,特别适合科学论证、以理服人,适合课程思政重构。通过精心挖掘、设计思政元素和润物无声、情感共鸣的教学方式,实现了价值引领和对专业学习的促进效果。

凝固浴中氯化锂的添加对PEDOT∶PSS导电纤维结构与性能的影响

以不同比例的丙酮/异丙醇为凝固浴,通过湿法纺丝制备聚3,4-乙撑二氧噻吩∶聚对苯乙烯磺酸(PEDOT∶PSS)纤维,确定纺丝最佳凝固浴配比是丙酮/异丙醇体积比1∶1。在此基础上,探究了凝固浴中加入不同量的氯化锂对PEDOT∶PSS纤维结构和性能影响,并分析其机理。采用扫描电子显微镜、数字万用表、电子单纤维强力仪、显微共聚焦拉曼光谱仪、X射线衍射仪对纤维结构和性能进行测试表征。结果表明,凝固浴中氯化锂的加入可使纤维内部均匀紧密,并有效增加纤维强度,在氯化锂质量分数为0.4%时,纤维强度高达(247±7.5)MPa;且氯化锂的添加不改变纤维的结晶,但能使PEDOT分子链的共轭结构缩短,增加缠结,提高纺丝连续性和纤维强度。

老年股骨转子间骨折术前康复训练效果研究

目的研究老年股骨转子间骨折(IFF)术前开始康复训练的治疗效果。方法回顾性分析2014年1月-2016年10月该院接受闭合复位防旋股骨近端髓内钉内固定术手术治疗的老年IFF患者110例。根据患者是否术前接受康复训练分为术前训练组和对照组,两组术后康复训练计划相同。比较两组并发症的发生情况,入院、出院时疼痛评分(VAS),术后早期离床活动率,出院及术后3个月Barthel指数评分,住院天数和住院费用。结果术前训练组术后并发症发生人数少于对照组,而术后早期离床活动率高于对照组(P<0.05);出院术前训练组VAS低于对照组(P<0.05),而Barthel指数评分高于对照组(P<0.05);住院天数有缩短,住院费用降低。患者出院后门诊随访3~6个月,失访7例。术前训练组术后3个月Barthel指数评分高于对照组(P<0.05)。结论老年IFF围手术期进行康复干预,物理治疗师术前开始对患者进行康复训练的效果优于术后开始康复训练。

Repetitive transcranial magnetic stimulation for lower extremity motor function in patients with stroke:a systematic review and network meta-analysis

Transcranial magnetic stimulation,a type of noninvasive brain stimulation,has become an ancillary therapy for motor function rehabilitation.Most previous studies have focused on the effects of repetitive transcranial magnetic stimulation(rTMS)on motor function in stroke patients.There have been relatively few studies on the effects of different modalities of rTMS on lower extremity motor function and corticospinal excitability in patients with stroke.The MEDLINE,Embase,Cochrane Library,ISI Science Citation Index,Physiotherapy Evidence Database,China National Knowledge Infrastructure Library,and ClinicalTrials.gov databases were searched.Parallel or crossover randomized controlled trials that addressed the effectiveness of rTMS in patients with stroke,published from inception to November 28,2019,were included.Standard pairwise meta-analysis was conducted using R version 3.6.1 with the“meta”package.Bayesian network analysis using the Markov chain Monte Carlo algorithm was conducted to investigate the effectiveness of different rTMS protocol interventions.Network meta-analysis results of 18 randomized controlled trials regarding lower extremity motor function recovery revealed that low-frequency rTMS had better efficacy in promoting lower extremity motor function recovery than sham stimulation.Network meta-analysis results of five randomized controlled trials demonstrated that highfrequency rTMS led to higher amplitudes of motor evoked potentials than low-frequency rTMS or sham stimulation.These findings suggest that rTMS can improve motor function in patients with stroke,and that low-frequency rTMS mainly affects motor function,whereas high-frequency rTMS increases the amplitudes of motor evoked potentials.More highquality randomized controlled trials are needed to validate this conclusion.The work was registered in PROSPERO(registration No.CRD42020147055)on April 28,2020.

Exogenous neural stem cell transplantation for cerebral ischemia

Cerebral ischemic injury is the main manifestation of stroke,and its incidence in stroke patients is 70–80%.Although ischemic stroke can be treated with tissue-type plasminogen activator,its time window of effectiveness is narrow.Therefore,the incidence of paralysis,hypoesthesia,aphasia,dysphagia,and cognitive impairment caused by cerebral ischemia is high.Nerve tissue regeneration can promote the recovery of the aforementioned dysfunction.Neural stem cells can participate in the reconstruction of the damaged nervous system and promote the recovery of nervous function during self-repair of damaged brain tissue.Neural stem cell transplantation for ischemic stroke has been a hot topic for more than 10 years.This review discusses the treatment of ischemic stroke with neural stem cells,as well as the mechanisms of their involvement in stroke treatment.

Different histological subtypes of parotid gland tumors: CT findings and diagnostic strategy

AIM:To present computed tomography(CT) findings of different histological subtypes of parotid gland masses in detail and to establish diagnostic strategy.METHODS:From January 2009 to November 2011,56 patients were collected through the histopathology and Picture Archiving and Communication Systems records,which revealed 5 basal cell adenoma(BCA),16 pleomorphic adenoma(PA),25 Warthin's tumor(War-T),3 Kimura's disease(KD) and 7 parotid carcinoma(PCa) cases.All the CT images were retrospectively analyzed by two radiologists in consensus,based on their description of morphology(location,number,size,margin and fibrous capsule) and enhancement patterns of masses.In addition,the diagnostic efficiency of diagnostic strategy is tested.RESULTS:War-T and BCA patients' mean age was 59.9 ± 12.6 years and 58.4 ± 18.2 years;the significant difference was seen in War-T vs PA and BCA vs PA.About 40% of War-Ts presented with bilateral multifocal lesions,a higher ratio than others.Seventy two percent of War-Ts were limited to the superficial lobe,followed by BCA 60% and PA 40%.Vessel facing sign and enlarged lymph nodes were both frequent in War-T,which respectively accounts for 84% and 76% of cases.Rapid contrast enhancement and decreases were unique for War-T.BCA and PA showed obvious delayed enhancement.The diagnostic strategy of parotid gland tumor had a good diagnostic efficiency,with high accuracy,sensitivity and specificity.CONCLUSION:Determination of the histological subtypes of parotid gland masses might be possible based on CT findings and clinical data.A diagnostic strategy with high diagnostic efficiency was established.

Drug-eluting fully covered self-expanding metal stent for dissolution of bile duct stones in vitro

BACKGROUND The treatment of difficult common bile duct stones(CBDS)remains a big challenge around the world.Biliary stenting is a widely accepted rescue method in patients with failed stone extraction under endoscopic retrograde cholangiopancreatography.Fully covered self-expanding metal stent(FCSEMS)has gained increasing attention in the management of difficult CBDS.AIM To manufacture a drug-eluting FCSEMS,which can achieve controlled release of stone-dissolving agents and speed up the dissolution of CBDS.METHODS Customized covered nitinol stents were adopted.Sodium cholate(SC)and disodium ethylene diamine tetraacetic acid(EDTA disodium,EDTA for short)were used as stone-dissolving agents.Three different types of drug-eluting stents were manufactured by dip coating(Stent I),coaxial electrospinning(Stent II),and dip coating combined with electrospinning(Stent III),respectively.The drugrelease behavior and stone-dissolving efficacy of these stents were evaluated in vitro to sort out the best manufacturing method.And the selected stonedissolving stents were further put into porcine CBD to evaluate their biosecurity.RESULTS Stent I and Stent II had obvious burst release of drugs in the first 5 d while Stent III presented controlled and sustainable drug release for 30 d.In still buffer,the final stone mass-loss rate of each group was 5.19%±0.69%for naked FCSEMS,20.37%±2.13%for Stent I,24.57%±1.45%for Stent II,and 33.72%±0.67%for Stent III.In flowing bile,the final stone mass-loss rate of each group was 5.87%±0.25%for naked FCSEMS,6.36%±0.48%for Stent I,6.38%±0.37%for Stent II,and 8.15%±0.27%for Stent III.Stent III caused the most stone mass-loss no matter in still buffer or in flowing bile,which was significantly higher than those of other groups(P<0.05).In vivo,Stent III made no difference from naked FCSEMS in serological analysis(P>0.05)and histopathological examination(P>0.05).CONCLUSION The novel SC and EDTA-eluting FCSEMS is efficient in diminishing CBDS in vitro.When conventional endoscopic techniques fail to remove difficult CBDS,SC and EDTA-eluting FCSEMS implantation may be considered a promising alternative.

Effects of anesthetic methods on preserving anti-tumor T-helper polarization following hepatectomy

AIM:To investigate the impact of different anesthetic techniques on T-helper(Th) cell subsets in hepatocellular carcinoma(HCC) patients undergoing hepatectomy.METHODS:Sixty-one HCC patients who received hepatectomies were randomized into an epidural combined general anesthesia(G + E;n = 31) or a general anesthesia(G;n = 30) group.Blood samples were obtained the morning before the operation(d0),and on the second(d2) and seventh(d7) day after the operation.Th cell contents were evaluated using flow cytometry,realtime reverse transcription-polymerase chain reaction and enzyme-linked immunosorbent assay.RESULTS:In all 61 patients,Th1 and Th2 cell frequencies,and interferon-(IFN-) mRNA expression markedly increased on d2,compared to d0.They recovered slightly on d7,and the Th1/Th2 ratio increased markedly on d7,compared with d2.In contrast,Th17,regulatory T cell(Treg),and interleukin-17(IL-17) levels and FOXP3 mRNA expression showed no significant change on d2,and then markedly decreased on d7.Similarly,plasma IFN-concentration on d2 was much higher than that on d0,and then partly recovered on d7.As compared with the G group,in the G + E group,Th1 cell frequencies and the Th1/Th2 ratio were slightly higher on d2 and significantly higher on d7,while Th2,Th17,and Treg cell frequencies were slightly lower on d2,and significantly lower on d7.Consistently,on d7,IFN-mRNA and protein levels and the IFN-/IL-4 ratio in the G + E group were higher than those in the G group.In contrast,the IL-17 mRNA level,and IL-17 and transforming growth factor-1 concentrations in the G + E group were lower than those in the G group.CONCLUSION:G + E is superior to G in shifting the Th1/Th2 balance towards Th1,while decreasing Th17 and Treg,potentially benefiting HCC patients by promoting anti-tumor Th polarization.

Abnormal activation of the occipital lobes during emotion picture processing in major depressive disorder patients

A large number of studies have demonstrated that depression patients have cognitive dysfunction. With recently developed brain functional imaging, studies have focused on changes in brain function to investigate cognitive changes. However, there is still controversy regarding abnormalities in brain functions or correlation between cognitive impairment and brain function changes. Thus, it is important to design an emotion-related task for research into brain function changes. We selected positive, neutral, and negative pictures from the International Affective Picture System. Patients with major depressive disorder were asked to judge emotion pictures. In addition, functional MRI was performed to synchronously record behavior data and imaging data. Results showed that the total correct rate for recognizing pictures was lower in patients compared with normal controls. Moreover, the consistency for recognizing pictures for depressed patients was worse than normal controls, and they frequently recognized positive pictures as negative pictures. The consistency for recognizing pictures was negatively correlated with the Hamilton Depression Rating Scale. Functional MRI suggested that the activation of some areas in the frontal lobe, temporal lobe, parietal lobe, limbic lobe, and cerebellum was enhanced, but that the activation of some areas in the frontal lobe, parietal lobe and occipital lobe was weakened while the patients were watching positive and neutral pictures compared with normal controls. The activation of some areas in the frontal lobe temporal lobe, parietal lobe, and limbic lobe was enhanced, but the activation of some areas in the occipital lobe were weakened while the patients were watching the negative pictures compared with normal controls. These findings indicate that patients with major depressive disorder have negative cognitive disorder and extensive brain dysfunction. Thus, reduced activation of the occipital lobe may be an initiating factor for cognitive disorder in depressed patients.

星蒌承气汤对急性缺血性中风小鼠中枢和外周免疫炎症的影响与肠道菌群有关

目的:探讨星蒌承气汤(Xinglou Chengqi decoction,XCD)对急性缺血性卒中小鼠脑–肠轴的影响。方法:根据中医辨证分型标准,采用改良Longa法建立痰热腑实证脑缺血再灌注模型。60只无特定病原体的雄性C57BL/6小鼠随机分为5组,36只经抗生素处理的(ABX)小鼠随机分为三组。采用酶联免疫吸附试验检测盲肠去甲肾上腺素(NE)和胃动素(MTL),免疫组织化学方法检测盲肠酪氨酸羟化酶(TH)蛋白表达水平,免疫荧光法检测Iba-1和胶质纤维酸性蛋白(GFAP)表达水平,流式多因子技术检测血清炎症因子含量。结果:与假手术组相比,大脑中动脉闭塞(MCAO)组盲肠组织中TH的表达水平显著升高(P=0.015)。与假手术组相比,MCAO组大鼠MTL水平显著升高(P<0.001),与MCAO组相比XCD组和尼莫地平(Nim)组大鼠血清MTL水平明显降低(P=0.003和P=0.007)。MCAO组星形胶质细胞和小胶质细胞明显激活,而XCD组激活程度低于MCAO组。ABX小鼠中星形胶质细胞和小胶质细胞在ABX–MCAO组明显激活,而ABX–XCD组激活程度较低。ABX–XCD组白细胞介素22水平较ABX–MCAO组显著升高(P=0.021)。结论:星蒌承气汤对急性缺血性卒中小鼠脑–肠轴的免疫通路有明显的调节作用,去除肠道菌群使该作用明显减弱。

Meclofenamic acid represses spermatogonial proliferation through modulating m^6A RNA modification

Background: N6-Methyladenosine(m^6A), the most prevalent modification in mammalian m RNA, plays important roles in numerous biological processes. Several m^6A associated proteins such as methyltransferase like 3(METTL3),methyltransferase like 14(METTL14), α-ketoglutarate-dependent dioxygenase Alk B homolog 5(ALKBH5) and YTH domain containing 2(YTHDC2) are involved in the regulation of spermatogenesis and oogenesis. However, the role of the first detected m^6A demethylase, fat mass and obesity associate protein(FTO), in germ cells remains elusive.Elucidation of FTO roles in the regulation of germ cell fate will provide novel insights into the mammalian reproduction.Methods: Mouse GC-1 spg cells were treated with the ester form of meclofenamic acid(MA2) to inhibit the demethylase activity of FTO. The cellular m^6A and m^6Amlevel were analyzed through high performance liquid chromatography combined with tandem mass spectrometry(HPLC/MS-MS). The cell apoptosis was detected via TUNEL and flow cytometry. The cell proliferation was detected through Ed U and western blot. The m RNA level of core cyclin dependent kinases(CDKs) was quantified via q-PCR. RNA decay assay were performed to detect RNA stability. Dual fluorescence assay was conducted to study whether MA2 affects the expression of CDK2 dependent on the m^6A modification at 3’UTR.Results: MA2 significantly increased the cellular m^6A level and down-regulated the expression of CDK1, CDK2, CDK6 and Cd C25 a, resulting in arrest of G1/S transition and decrease of cell proliferation. MA2 downregulated CDK2 m RNA stability. Additionally, mutation of the predicted m^6A sites in the Cdk2–3’UTR could mitigated the degradation of CDK2 m RNA after MA2 treatment.Conclusion: MA2 affected CDKs expression through the m^6A-dependent m RNA degradation pathway, and thus repressed spermatogonial proliferation.

Extremely low frequency electromagnetic fields promote cognitive function and hippocampal neurogenesis of rats with cerebral ischemia

Extremely low frequency electromagnetic fields(ELF-EMF) can improve the learning and memory impairment of rats with Alzheimer's disease, however, its effect on cerebral ischemia remains poorly understood.In this study, we established rat models of middle cerebral artery occlusion/reperfusion.One day after modeling, a group of rats were treated with ELF-EMF(50 Hz, 1 mT) for 2 hours daily on 28 successive days.Our results showed that rats treated with ELF-EMF required shorter swimming distances and latencies in the Morris water maze test than those of untreated rats.The number of times the platform was crossed and the time spent in the target quadrant were greater than those of untreated rats.The number of BrdU~+/NeuN~+ cells, representing newly born neurons, in the hippocampal subgranular zone increased more in the treated than in untreated rats.Up-regulation in the expressions of Notch1, Hes1, and Hes5 proteins, which are the key factors of the Notch signaling pathway, was greatest in the treated rats.These findings suggest that ELF-EMF can enhance hippocampal neurogenesis of rats with cerebral ischemia, possibly by affecting the Notch signaling pathway.The study was approved by the Institutional Ethics Committee of Sichuan University, China(approval No.2019255A) on March 5, 2019.

Sertoli cell and spermatogonial development in pigs

Background:Spermatogenesis is an intricate developmental process during which undifferentiated spermatogonia,containing spermatogonial stem cells(SSCs),undergo self-renewal and differentiation to generate eventually mature spermatozoa.Spermatogenesis occurs in seminiferous tubules within the testis,and the seminiferous tubules harbor Sertoli and germ cells.Sertoli cells are an essential somatic cell type within the microenvironment that support and steer male germ cell development,whereas spermatogonia are the primitive male germ cells at the onset of spermatogenesis.While the developmental progression of Sertoli cells and spermatogonia has been well established in mice,much less is known in other mammalian species including pigs.Results:To acquire knowledge of Sertoli cell and spermatogonial development in pigs,here we collected as many as nine ages of Duroc porcine testes from the neonate to sexual maturity,i.e.,testes from 7-,30-,50-,70-,90-,110-,130-,150-and 210-day-old boars,and performed histological and immunohistochemical analyses on testis sections.We first examined the development of spermatogenic cells and seminiferous tubules in porcine testes.Then,by immunofluorescence staining for marker proteins(AMH,SOX9,DBA,UCHL1,VASA,KIT,Ki67 and/or PCNA),we delved into the proliferative activity and development of Sertoli cells and of spermatogonial subtypes(pro-,undifferentiated and differentiating spermatogonia).Besides,by immunostaining forβ-catenin and ZO-1,we studied the establishment of the blood-testis barrier in porcine testes.Conclusions:In this longitudinal study,we have systematically investigated the elaborate Sertoli cell and spermatogonial developmental patterns in pigs from the neonate to sexual maturity that have so far remained largely unknown.The findings not only extend the knowledge about spermatogenesis and testicular development in pigs,but also lay the theoretical groundwork for porcine breeding and rearing.