关岭及相关生物群沉积与生态环境的探讨

根据近年来对黔东南至滇东关岭、兴义、贞丰和罗平等地中-晚三叠世含海生爬行动物骨架和(或)深水海百合黑色岩系(通常所称黑色页岩)化石库的研究,现将该区岩石地层单位划分,以及这些黑色岩系化石库生物组合特征、时代、分布、沉积和古地理环境概括如下:1)在关岭—兴义地区中-晚三叠世(安尼期、拉丁期和早卡尼期)地层中,至少夹有3层、甚至4层含海生爬行动物的黑色岩系化石库(或黑色"页岩"化石库),自下而上产盘县生物群、兴义生物群和关岭生物群。云南罗平地区中三叠统关岭组中新发现的"罗平生物群"与盘县生物群层位大致相当。贞丰龙场赖石科组上部新挖掘出的30m厚产创口海百合、双壳类及菊石的黑色岩系,应该是研究地区最高层位的海相三叠纪黑色岩系,时代似属晚三叠世早卡尼期晚期;2)推测这些含海生爬行动物骨架的黑色岩系化石库是在印支造山运动影响下,伴随南盘江前陆盆地隆升和闭合,在扬子克拉通台地边缘所形成的一个或几个边缘凹陷、或边缘盆地之中形成的,这些凹陷或盆地形成之初,表层水充氧,且具有很好的食物链结构,有利于各类海生生物生活;后来的海平面上升至最大海泛期,以及由此引起缺氧和含硫化氢水位的上升,导致这些凹陷逐渐变成安静、滞流的死亡之海和黑色岩系化石库;3)关岭生物群产于晚三叠世卡尼期早期小凹组下段上部黑色岩系之中,是一个典型的在滞流、缺氧且海底没有食腐动物边缘局限盆地中所形成的黑色页岩化石库,以产大量海生爬行动物和深水假浮游海百合为特征,此外还有个别的两栖类和原始龟类发现;4)产于竹杆坡组近底部黑色岩系中的兴义生物群,以产大量肿肋龙类为特点,尤以个体较小的贵州龙最为常见,共生的还有多种鱼类化石,在生物组合和产出层位上,可与阿尔卑斯南部Meride灰岩所夹黑色含沥青页岩化石库对比,时代似应归属拉丁期早或中期;大量米虾在竹杆坡组近底部含贵州龙层的发现,推测兴义生物群可能形成于台地边缘早期并不缺氧,且具有理想食物链结构的浅水、超盐的凹陷或盆地之中。由于存在浮游生物—虾—贵州龙—欧龙—虾—浮游生物所组成的生态组合和食物链结构,从而为解释以肿肋龙类为代表的兴义生物群的繁衍和多生提供了依据;接踵而来的沉积速率下降和缺氧水位的上升,以及间歇性火山作用,导致该特有生态体系的崩溃和化石库的形成。根据对贞丰挽澜竹杆坡组底部首次发现的棘皮动物的化石库的研究,指出该化石库系由海星、细小蛇尾、底栖海百合茎、海胆和海参等5类棘皮动物化石和含贵州龙骨架碎片组成,其下为8m厚夹有薄层的骨层的凝缩层沉积,后者位于硬底之上。此种沉积和埋藏模式与德国上壳灰岩早拉丁期的棘皮动物化石库类似,是在近岸海水不太浅的内陆棚的环境下,由于风暴潮作用所形成的化石库,他们与在滞流、缺氧海底、通过化石聚集所形成的化石库是不同的;5)产盘县生物群的黑色岩系化石库主要见于盘县羊件和普安青山中三叠世(安尼期)关岭组中,与云南罗平地区的"罗平生物群"在层位及生物组合上大致相当,均以含大量混鱼龙、幻龙和欧龙,以及鱼类为特点,共生的还有大量节肢动物。所不同的是后者由于靠近滨岸,故而出现大量幼年期的鱼类以及虾类和鲎类化石,推测他们形成于靠近古陆或滨岸的台缘浅水表层充氧的正常、且有时超盐的凹陷之中,时代上早于阿尔卑斯南部安尼期/拉丁期比塞娄组;其集群死亡除因后期盆地滞流、缺氧外,可能还与风暴和火山作用有关。

影响猪体细胞核移植重构胚体外发育的若干因素

以卵丘细胞为核供体细胞组成重构胚,卵裂率达到56.7%,发育至桑椹胚达11.7%、孵化囊胚率为6.7%,显著高于成纤维细胞组成的重构胚(p<0.05)。我们研究了卵母细胞的采集方法,激活方法和卵龄对卵丘细胞核移植重构胚体外发育的影响。以血清饥饿法将卵丘细胞诱导至GO或G1期,抽吸法/解剖法采集卵母细胞,体外培养33或44 h,将卵丘细胞置于去核卵母细胞的卵周隙中,重构胚以钙离子载体A23817或电脉冲结合6-DMAP激活处理,体外培养6天,结果表明,卵母细胞采集方法、激活液中细胞松弛素(CB)并不影响重构胚的发育(以卵龄44h的卵母细胞为受体);而以电脉冲结合6-DMAP激活处理能提高重构胚发育能力(以卵龄33 h的卵母细胞为受体)(p<0.05)。本研究显示,以电脉冲结合6-DMAP激活卵丘细胞重构胚。

不同供体细胞及其处理对猪核移植重构胚体外发育的影响

系统探讨了体细胞的组织来源及培养代数对猪核移植重构胚发育的影响。体外成熟培养40～44h的猪卵母细胞去核后，将经血清饥饿（0．5％FBS）培养2～9天、0．1mg／L Aphidicolin（APD）培养＋0．5％FBS培养2～9天或一般培养法（10％FBS）培养的卵丘细胞、颗粒细胞、输卵管上皮细胞和耳皮成纤维细胞，直接注射到去核的卵母细胞质中，或注射到卵周隙中，再经电融合（100V／mm，30μs，电脉冲1次）构建重构胚．重构胚以钙离子载体A23817或电脉冲结合6．DMAP激活处理，体外培养6天。耳皮成纤维细胞和颗粒细胞经0．1mg／LAPD＋0．5％FBS培养处理后的重组胚卵裂率，均高于血清饥饿和一般培养处理的同种供体细胞（P〈0．01）。卵丘细胞、颗粒细胞经0．1mg／LAPD＋0．5％FBS处理后进行核移植的分裂率和发育率均高于输卵管上皮细胞和耳皮成纤维细胞（P〈0．05）。以猪颗粒细胞为核供体时，电融合法的重构胚分裂率显著高于胞质内注入法（P〈0．05），但囊胚发育率无显著差异（P〉0．05）。培养3代和6代的猪颗粒细胞以及培养6代和10代的耳皮成纤维细胞，其具有正常二倍染色体的细胞比例均无显著差异（P〉0．05）；以这2种细胞不同培养代数做供体进行核移植时，各代之间核移胚的体外分裂率、囊胚发育率无显著差异（P〉0．05）。这些结果表明：（1）猪耳皮成纤维细胞和颗粒细胞经培养传代所建立起来的细胞系相对比较稳定；（2）0．1mg／LAPD预培养处理供体细胞能提高猪体细胞核移植的效果，血清饥饿培养则无明显效果；（3）猪颗粒细胞和耳皮成纤维细胞等均可做供核细胞，核移植后都能得到体细胞克隆的囊胚，但前者的效果略优于后者，且其核移植效果不受供核细胞培养代数的影响；（4）电融合核移植胚胎的发育率高于胞质内直接注入法，但两者的总体效率相近。

猪卵母细胞去核方法的改进

对猪体细胞克隆技术中关键步骤之一的去核方法作了较深入的研究。结果表明,由本实验室改进的Willadsen去核法———二步挤压去核法,无论在去核操作成功率(73.9%)上还是在去核效率(81.2%)上都明显好于McGrath-Solter去核法(42.5%、67.4%,P<0.05);同时,本试验还发现,卵母细胞成熟培养36 h后去核组去核效率(89.1%)显著地高于成熟培养44 h后去核组(55.8%,P<0.05),而核移植重构胚的发育率2个组间无显著差异。

体细胞的组织来源及培养代数对猪核移植重构胚发育的影响

本研究系统探讨了体细胞的组织来源及培养代数对猪核移植重构胚发育的影响。体外成熟培养40-44h的猪卵母细胞去核后,将经血清饥饿(0．5%FBs)培养2-9d、0．1mg/L Aphidicolin (APD)培养+0．5%FBS培养2-9d或一般培养法(10%FBS)培养的卵丘细胞、颗粒细胞、输卵管上皮细胞和耳皮成纤维细胞,直接注射到去核的卵母细胞质中,或注射到卵周隙中。再经电融合(100V/mm,30μs,电脉冲1次)构建重构胚。重构胚以钙离子载体A23817或电脉冲结合6- DMAP激活处理,体外培养6天。耳皮成纤维细胞和颗粒细胞经0．1mg/L APD+0．5%FBS培养处理后的重组胚卵裂率,均高于血清饥饿和一般培养处理的同种供体细胞(P＜0．01)。卵丘细胞、颗粒细胞经0．1mg/L APD+0．5%FBS处理后进行核移植的分裂率和发育率均高于输卵管上皮细胞和耳皮成纤维细胞(P＜0．05)。以猪颗粒细胞为核供体时,电融合法的重构胚分裂率显著高于胞质内注入法(P＜0．05),但囊胚发育率无显著差异(P＞0．05)。培养3代和6代的猪颗粒细胞以及培养6代和10代的耳皮成纤维细胞,其具有正常二倍染色体的细胞比例均无显著差异(P＞0．05)；以这2种细胞不同培养代数做供体进行核移植时,各代之间核移胚的体外分裂率、囊胚发育率无显著差异(P＞0．05)。这些结果表明：(1)猪耳皮成纤维细胞和颗粒细胞经培养传代所建立起来的细胞系相对比较稳定；(2)0．1mg/L APD预培养处理供体细胞能提高猪体细胞核移植的效果,血清饥饿培养则无明显效果；(3)猪颗粒细胞和耳皮成纤维细胞等均可做供核细胞．核移植后都能得到体细胞克隆的囊胚,但前者的效果略优于后者,且其核移植效果不受供核细胞培养代数的影响；(4)电融合核移植胚胎的发育率高于胞质内直接注入法,但两者的总体效率相近。

不同氮肥形态组合肥料与施肥方法对球茎甘蓝生长的影响

本文研究了不同氮肥形态与施肥方法对球茎甘蓝生长的影响,结果表明:与传统硝态氮比较,铵态氮营养中硫酸铵和尿素或硫酸铵和磷酸二铵的混合处理可以提高球茎甘蓝块茎的产量、提高球茎甘蓝块基重量与叶子重量的比例,其中以石膏和高岭土混合物为添充物、以硫酸铵和磷二铵混合物处理的球茎甘蓝块茎的产量最高,同时这些处理对植物体内铁、锰与铜等营养元素的浓度也有一定的提高。

Development in vitro in Reconstitution of Embryo from Porcine Somatic Cell Nuclear Transfer

In present paper,a study on reconstitution of porcine oocytes by using nuclear transfer with cumulus cells(CC) and fibroblast cells(FC) was carried out.Reconstituted oocytes which were the fusion with CC and showed a cleavage rate of 56.7%,developed into morula (11.7%) and blastocysts (6.7%) phases which were higher than those derived from the fusion with FC( P <0.05).The results of this study also involved the effects of oocyte collection method,activation protocol and maturational age of recipient oocytes during the in vitro develpoment of nuclear transfer embryos which were reconstituted with cultured cumulus cells.The cumulus cells synchronized in G 0/G 1 phases through serum starvation culture,were transferred into enuclated oocytes which were collected by aspiration or dissection method and cultured for 33 or 44 h.Reconstituted embryos were activated with a combination of calcium ionophore A23187 or electric pulsation and 6 DMAP,and cultured for 6 days.As for the oocyte collection methods,activation treatment in the presence of cytochalasin B and activation protocols did not affect the developmental rate of embryos reconstituted with 44 h mature recipients.However,the development rate of reconstituted embryos with 33 h mature recipients were significantly higher( P <0.05) by activation with the combination of electric pulsation and 6 DMAP.These results suggest that the reconstituted porcine embryos derived from cultured cumulus cells can develop into the blastocyst stage and that the development of the former could be improved for the reconstitution with young oocyte cytoplast after the activation with the combination of electric pulsation and 6 DMAP.

早期胚胎心肌细胞兴奋收缩耦联模式

目的研究胚胎心肌细胞兴奋收缩耦联的机理;方法使用膜片钳与钙离子浓度分析系统测量酶消化法得到的小鼠胚胎心肌细胞的膜电位与细胞内钙离子浓度;结果细胚胎心肌细胞存在两种兴奋收缩耦联模式,一种与正常成熟心肌细胞的兴奋收缩耦联模式类似,与细胞膜上的钠通道、L-钙离子通道相关;另一种由细胞内钙振荡诱发,这种钙振荡通过细胞膜上的钠钙交换蛋白引起了细胞膜电位的小幅度变化,该模式是一种更基本的兴奋收缩模式。近似熵分析表明,与后一种模式相比较,前一种模式的规律性更强。结论胚胎心肌细胞存在两种兴奋收缩耦联模式。

Noninvasive model including right ventricular speckle tracking for the evaluation of pulmonary hypertension

AIM To find parameters from transthorathic echocardiography(TTE) including speckle-tracking(ST) analysis of the right ventricle(RV) to identify precapillary pulmonary hypertension(PH).METHODS Forty-four patients with suspected PH undergoing right heart catheterization(RHC) were consecutively included(mean age 63.1 ± 14 years, 61% male gender). All patients underwent standardized TTE including ST analysis of the RV. Based on the subsequent TTE-derived measurements, the presence of PH was assessed: Left ventricular ejection fraction(LVEF) was calculated by Simpsons rule from 4Ch. Systolic pulmonary artery pressure(s PAP) was assessed with continuous wave Doppler of systolic tricuspid regurgitant velocity and regarded raised with values ≥ 30 mmH g as a surrogate parameter for RA pressure. A concomitantly elevated PCWP was considered a means to discriminate between the precapillary and postcapillary form of PH. PCWP was considered elevated when the E/e' ratio was > 12 as a surrogate for LV diastolic pressure. E/e' ratio was measured by gauging systolic and diastolic velocities of the lateral and septal mitral valve annulus using TDI mode. The results were then averaged with conventional measurement of mitral valve inflow. Furthermore, functional testing with six minutes walking distance(6MWD), ECG-RV stress signs, NT pro-BNP and other laboratory values were assessed.RESULTS PH was confirmed in 34 patients(precapillary PH, n = 15, postcapillary PH, n = 19). TTE showed significant differences in E/e' ratio(precapillary PH: 12.3 ± 4.4, postcapillary PH: 17.3 ± 10.3, no PH: 12.1 ± 4.5, P = 0.02), LV volumes(ESV: 25.0 ± 15.0 mL, 49.9 ± 29.5 m L, 32.2 ± 13.6 m L, P = 0.027; EDV: 73.6 ± 24.0 mL, 110.6 ± 31.8 mL, 87.8 ± 33.0 mL, P = 0.021) and systolic pulmonary arterial pressure(sP AP: 61.2 ± 22.3 mm Hg, 53.6 ± 20.1 mm Hg, 31.2 ± 24.6 mm Hg, P = 0.001). STRV analysis showed significant differences for apical RV longitudinal strain(RVAS: -7.5% ± 5.6%, -13.3% ± 4.3%, -14.3% ± 6.3%, P = 0.03). NT pro-BNP was higher in patients with postcapillary PH(4677.0 ± 7764.1 pg/m L, precapillary PH: 1980.3 ± 3432.1 pg/mL, no PH: 367.5 ± 420.4 pg/mL, P = 0.03). Patients with precapillary PH presented significantly more often with ECG RV-stress signs(P = 0.001). Receiver operating characteristics curve analyses displayed the most significant area under the curve(AUC) for RVAS(cut-off < -6.5%, AUC 0.91, P < 0.001), sPAP(cut-off > 33 mmH g, AUC 0.86, P < 0.001) and ECG RV stress signs(AUC 0.83, P < 0.001). The combination of these parameters had a sensitivity of 82.8% and a specificity of 17.2% to detect precapillary PH. CONCLUSION The combination of non-invasive measurements allows feasible assessment of PH and seems beneficial for the differentiation between the pre- and postcapillary form of this disease.

Early Miocene flora of central Kazakhstan(Turgai Plateau) and its paleoenvironmental implications

The investigation of the fossil floras from the Turgai plateau (central Kazakhstan) contributes to a better understanding of the origin of the temperate Turgai type flora which spread to Kazakhstan and adjacent areas during the Oligocene-Miocene transition. In this paper, we present the results of a carpological and palynological study of the Kumyrtas flora collected from a flora-bearing horizon of the regional coalbearing Zhilanchik suite, dated to the Aquitanian period. Pollen analysis identified 33 taxa, with are dominated by angiosperms (about 73%) and reflect zonal vegetation. The high percentages of Betula (27%) and Pterocarya (7.5%) that were found in this flora allows comparisons with other Aquitanian floras of Kazakhstan. Based on descriptions of fossil fruits and seeds, we determined that 19 taxa were dominant;these taxa had meosphytic herbaceous components, suggesting mostly edaphic local conditions. The incongruence between the carpological and the pollen records suggests a significant taphonomical effect. Quantitative reconstruction of the palaeoclimate based on pollen records supports—and slightly extends—previous findings based on fossil leaf data, but contradicts findings deduced from the carpological record. Plant Functional Type (PFT) classification was used to characterize the vegetation patterns. Pollen records show that about 45% of diversity relates to the arboreal broadleaved deciduous components and ca. 35% to conifers. Fossil fruit and seed data indicate riverine vegetation with a high diversity of aquatic components and shrub stratum.

Analysis of Rural Water Pollution Sources of Lushui Reservoir in Hubei Province

Pollution resulting from increased human activities is threatening the drinking water quality in China.Lushui Reservoir was selected as a typical example to represent polluted drinking water sources with rapid social economic development.This study analyzed the pollution load of Lushui Reservoir from rural areas by estimating the chemical oxygen demand(COD),ammonia nitrogen,total nitrogen and total phosphorus contributed by domestic sewage,agricultural activity,livestock breeding and aquaculture activity.Results show that the annual chemical oxygen demand,ammonia nitrogen,total nitrogen and total phosphorus loads in Lushui Reservoir were 180.44,22.99,33.15,and 3.99 t,respectively.The highest contribution to pollution load in all four aspects is domestic sewage,which was 89%,96%,82%,and 79%,respectively.Therefore,policies for sustainable development in the region should be directed primarily towards a reduction of domestic pollution.

Two new species from Sulawesi and Borneo facilitate phylogeny and taxonomic revision of Engelhardia(Juglandaceae)

Engelhardia,a genus of Juglandaceae(the walnut family),is endemic to tropical and subtropical Asia.The rich Cenozoic fossil records and distinctive morphological characters of the living plants have been used to explore the evolutionary history and geographic distribution of Juglandaceae.However,the taxonomy of this genus has been suffered from a lack of in-depth investigation and good specimens across its distribution ranges.Species delimitation of Engelhardia was defined with seven species in 2020,but detailed information on the circumscription of the species still remains poorly understood.In this study,two new species are described from Sulawesi and Borneo,Engelhardia anminiana and E.borneensis.We also revised and reconstructed the phylogeny within Engelhardia using morphological,molecular(plastid and ribosomal),and distribution data.We sampled 787 individuals in 80 populations,and all the samples were genotyped using plastid regions,trnS-trnG,rps16,trnL-trnF,psbA-trnH,and rpl32-trnL;one ribosomal region,nuclear ribosomal internal transcribed spacer(nrITS).The all datasets were used to reconstruct the phylogenetic relationships.Then,the molecular analyses were combined for 738 sheets of specimens with 15 morphological characteristics to further explore the morphological clusters of Engelhardia.Cluster analysis using morphological data confirmed the delimitation of nine Engelhardia species.Also,phylogenetic analysis based on molecular data(i.e.,plastid and ribosomal)supported the monophyly of Engelhardia and generated phylogenetic trees that included E.fenzelii,E.roxburghiana,E.borneensis,E.hainanensis,E.anminiana,E.serrata,E.villosa,E.apoensis and the varieties of E.spicata(i.e.,E.spicata var.spicata,E.spicata var.rigida,E.spicata var.aceriflora,and E.spicata var.colebrookeana).Our comprehensive taxonomic revision of Engelhardia will provide an insight into understanding the plant diversity in tropical and subtropical Asia.

Separability of Dominant Crop Cultures in Southern Germany Using TerraSAR-X Data

The research aims at differentiating dominant crop cultures in two test sites of Baden-Wuert- temberg, Southern Germany by creating crop signatures from radar backscatter values. It seeks to establish whether the crop signatures collected in one test site are comparable or transferable to another test site. The two test sites are located in different agro-ecological zones as described in the climate maps of the “Klimaatlas Baden-Wuerttemberg”. TerraSAR-X images (VV polarization) for the months of July and August 2010 were overlaid with crop fields’ ground truth data. As pre-processing steps, radiometric correction was carried out on the images in order to normalize the topographical effects. Classification of the crops was performed on a field scale, according to the mean and standard deviation of their backscatter values. From the results, potatoes could be uniquely differentiated from the cereals in the two different test sites for both the months of July and August 2010. Cereals (rapes, maize, barley, wheat and oats) had comparable backscatter values and their differentiation varied from one test site to another. The results’ accuracy obtained with a maximum kappa coefficient of 0.82 agrees with results of a similar research carried out in North East Germany.

Geochemical element balance during tropical weathering. Hercynian Rheinisches Schiefergebirge (Germany): a case study

Introduction The Rheinisches Schiefergebirge, the northern,non metamorphic part of the Hercynian orogen in Middle Europe is one of the most excellent examples of a stable continental area, deeply weathered under a tropical to subtropical climate during upper Mesozoic and especially Paleogene periods.

Necroptosis, pyroptosis and apoptosis: an intricate game of cell death

Cell death is a fundamental physiological process in all living organisms.Its roles extend from embryonic development,organ maintenance,and aging to the coordination of immune responses and autoimmunity.In recent years,our understanding of the mechanisms orchestrating cellular death and its consequences on immunity and homeostasis has increased substantially.Different modalities of what has become known as‘programmed cell death’have been described,and some key players in these processes have been identified.We have learned more about the intricacies that fine tune the activity of common players and ultimately shape the different types of cell death.These studies have highlighted the complex mechanisms tipping the balance between different cell fates.Here,we summarize the latest discoveries in the three most well understood modalities of cell death,namely,apoptosis,necroptosis,and pyroptosis,highlighting common and unique pathways and their effect on the surrounding cells and the organism as a whole.

Aluminium toxicity targets PIN2 in Arabidopsis root apices: Effects on PIN2 endocytosis, vesicular recycling, and polar auxin transport

The most obvious symptom of Al toxicity is the inhibition of root growth. However, the mechanism of Al-inhibiting root growth remains to be elucidated. In this study, auxin transport and vesicle movement of an auxin-efflux carrier (PIN2) were investigated in Arabidopsis roots in response to Al stress. Results indicated that Al inhibited the apical transport of auxin in root tips of Arabidopsis significantly. The severe inhibition was localized in the cells of transition zone, where the concentration of auxin was only 34% that of the control. Brefeldin A (BFA), an inhibitor of vesicle transport, induced the dot-like structure of PIN2 vesicle significantly. Al decreased the size of dot-like structure of PIN2 vesicles. Re- sults of real-time RT-PCR and Western-blotting analysis showed that Al increased the transcript level of PIN2 and the accumulation of PIN2 protein in horizontal direction of plasma membrane, but decreased its distribution in endosomes, suggesting that Al inhibited the transport of PIN2 vesicles from plasma membrane to endosomes. Results of cytoskeleton-depolymering drugs indicated that it was via the pathway of disruption of actin microfilaments that Al inhibited the transport of PIN2 vesicles. Exposed to Al stress, the cells of elongation zone had less Al uptake and less transport frequency of vesicles than cells of transition zone. Taken together, our results suggested that Al inhibited root growth mainly by modulating the transport of PIN2 vesicles between plasma membrane and endosomes, thus block- ing auxin transport and root growth.

Iron fractions in the apoplast of intact root tips of Zea mays L. seedlings affected by nitrogen form

The effects of ammonium (NH4+-N) and nitrate (NO3- - N) were examined on Fe fractions and FeCN (ferricyanide) reductase activity in intact root tips (0-3 cm) of young maize (Zea mays L. cv. Lenz) in solution culture by using short-term experiment under controlled Fe deficiency conditions (containing high HCO3- concentration in pre-culture solution). The results showed that Fe(Ⅱ) concentrations in root tip apoplast of maize were only 20-40 nmol/g FW which accounted for 7%-13% of total Fe. Most of Fe in root tips existed as Fe(Ⅲ) compounds. Imposition of the roots to NH4+ - N or NO3- - N for 60 min led to an increase of Fe(Ⅱ) in root tip apoplast. NH4+ - N led to an increased concentration of Fe(Ⅱ) and exchangeable Fe (Fe(Ⅱ) and Fe (Ⅲ)) in root tips, while NO3- - N increased FeCN reductase activity. The relationship between pH and Fe fractions, FeCN reductase activity was also discussed.

How location and cellular signaling combine to activate the NLRP3 inflammasome

NOD-,LRR-,and pyrin domain-containing 3(NLRP3)is a cytosolic innate immune sensor of cellular stress signals,triggered by infection and sterile inflammation.Upon detection of an activating stimulus,NLRP3 transitions from an inactive homo-oligomeric multimer into an active multimeric inflammasome,which promotes the helical oligomeric assembly of the adaptor molecule ASC.ASC oligomers provide a platform for caspase-1 activation,leading to the proteolytic cleavage and activation of proinflammatory cytokines in the IL-1 family and gasdermin D,which can induce a lytic form of cell death.Recent studies investigating both the cellular requirement for NLRP3 activation and the structure of NLRP3 have revealed the complex regulation of NLRP3 and the multiple steps involved in its activation.This review presents a perspective on the biochemical and cellular processes controlling the assembly of the NLRP3 inflammasome with particular emphasis on structural regulation and the role of organelles.We also highlight the latest research on metabolic control of this inflammatory pathway and discuss promising clinical targets for intervention.