Mesozoic volcanic rocks and granitoids are widespread in the Great Xing'an Range, which is part of a large igneous province in the eastern China. However, the ages of the volcanic rocks, especially ...those in the southern segment of the range, are poorly constrained. Here we present zircon U–Pb and whole rock Ar–Ar ages of 43 volcanic rocks from the four recognized formations (Manketouebo, Manitu, Baiyingaolao and Meiletu) in the southern Great Xing'an Range. The volcanic rocks of the Manketouebo Formation have a large span of ages ranging from 174 to 122
Ma, while those of the Manitu Formation exhibit a smaller age range from 156 to 125
Ma. The Baiyingaolao and Meiletu volcanic rocks both have Early Cretaceous ages between 139 and 124
Ma. These data indicate that the mapped units are not strictly ‘formations’ and further studies are required to resolve this issue. However, when taken together, these new data define two episodes of magmatism (Late Jurassic and Early Cretaceous) with the Early Cretaceous volcanic rocks being dominant. Combined with previously published data from the northern Great Xing'an Range, and available age data from other parts of northeastern China and surrounding regions, two stages of magmatism, i.e., Jurassic and Early Cretaceous, can be identified throughout this part of Asia. The Jurassic rocks mainly comprise granites, while volcanic rocks are dominant in the Early Cretaceous. These two stages of magmatism form opposite spatial trends, that is, the Jurassic rocks become younger to the west, whereas the Cretaceous rocks become younger to the east. Between the two stages of magmatism, the ‘magma gap’ increases eastward in duration from less than 10
Ma in the Great Xing'an Range to more than 40
Ma in Japan. These trends can be explained by westward subduction of the Paleo-Pacific oceanic Plate and its control on subsequent geodynamic processes. Jurassic subduction of the oceanic slab caused crustal shortening and thickening, and formed the westward decrease in age of the granites with characteristics of an active continental margin, while volcanism was rare. By the end of the Jurassic, westward flat-slab subduction of the Paleo-Pacific Oceanic plate changed its direction to the north or northwest. This subsequently caused a transformation in tectonic regime from compression to extension in the Cretaceous and induced large-scale delamination of the thickened lower crust and lithospheric mantle. Delamination was initiated at the western margin of the subducting slab, and migrated eastward. Delamination and consequent upwelling of the asthenosphere triggered extensive volcanic eruption, with only minor granite emplacement. Similar age trends are also observed for other parts of eastern China, suggesting this model can also be applied to explain the geodynamic setting of the Mesozoic large igneous events in China and adjacent regions.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
The Hengduan Mountains (HDM) biodiversity hotspot exhibits exceptional alpine plant diversity. Here, we investigate factors driving intraspecific divergence within a HDM alpine species Salix ...brachista (Cushion willow), a common component of subnival assemblages. We produce a high-quality genome assembly for this species and characterize its genetic diversity, population structure and pattern of evolution by resequencing individuals collected across its distribution. We detect population divergence that has been shaped by a landscape of isolated sky island-like habitats displaying strong environmental heterogeneity across elevational gradients, combined with population size fluctuations that have occurred since approximately the late Miocene. These factors are likely important drivers of intraspecific divergence within Cushion willow and possibly other alpine plants with a similar distribution. Since intraspecific divergence is often the first step toward speciation, the same factors can be important contributors to the high alpine species diversity in the HDM.
Major and trace element, whole rock Sr‐, Nd‐and Hf‐isotopes and zircon U–Pb age and Hf–O isotope data have been determined for mafic to felsic intrusive rocks from the Late Triassic Mayihe (MYH), ...Longtou–Chaxinzi–Xiaoweishahe (LCX) and Nankouqian–Xidadingzi (NX) intrusions in the northern Liaodong Peninsula, NE China, in order to investigate their sources and petrogenesis related to decrationization of the North China Craton. The rocks include clinopyroxene diorite, monzodiorite, quartz diorite, granodiorite, monzogranite and mafic microgranular enclaves. Laser ablation inductively coupled plasma mass spectrometry (LA–ICPMS) and secondary ion mass spectrometer (SIMS) U–Pb analyses of zircon from MYH, LXC to NX intrusions yield Late Triassic ages of 224–218Ma, establishing that the mafic and felsic magmas were coeval. The clinopyroxene diorites from the MYH pluton have high MgO concentrations at low silica contents, with positive whole rock εNd(t) (up to +3.8) and εHf(t) (up to +6.2) and zircon εHf(t) values and some mantle-like δ18O values. They are enriched in large ion lithophile (LILEs) and light rare earth elements (LREEs) and depleted in high field strength elements (HFSEs), which can be explained as melts derived from a depleted mantle, with some subsequent crustal contamination. However, the diorites from the LXC and NX intrusions are high‐K rocks and have high MgO concentrations and mantle-like δ18O values, but with negative whole rock εNd(t) (−12.9 to −7.6) and εHf(t) (−14.0 to −5.6) and zircon εHf(t) values, distinct from those of MYH pyroxene diorites, indicating that their parental magmas were derived from partial melting of an ancient lithospheric mantle. The granitoids from three plutons have high SiO2 contents and low MgO concentrations, suggesting they were mainly derived from crustal sources. However, the MYH monzogranite and granodiorite have positive whole rock εNd(t) and εHf(t) (up to +3.0) and zircon εHf(t) values, indicating a juvenile crustal source, whereas, the LXC and NX granitoids have strong negative and variable whole rock εNd(t) and εHf(t) and zircon εHf(t) values, indicating that they were derived from partial melting of ancient lower crustal materials with involvement of mantle components. Field observations, geochronology, geochemistry, Sr–Nd–Hf isotopic and zircon Hf–O isotopic compositions point to a complex petrogenesis, where mantle- and crust-derived magma mixing was coupled with crystal fractionation, thus explaining the genetic link between mafic and felsic rocks. Identification of four components, i.e., depleted and enriched mantle and juvenile and ancient crust in the Late Triassic magmatism in the northern Liaodong Peninsula suggests a strong mantle–crust interaction process related to decratonization of the North China Craton.
► Magmatism related to decratonization of the North China Craton (NCC). ► Zircon Hf–O isotopes show multiple sources in the origin of Late Triassic magmatism. ► Magma mixing and AFC processes in the genesis of granitoids. ► Lithospheric architecture related to decratonization.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
Aim
Endogenous dynorphin signaling via kappa opioid receptors (KORs) plays a key role in producing the depressive and aversive consequences of stress. We investigated the behavioral effects of the ...dynorphin/KOR system in the ventral pallidum (VP) and studied the underlying mechanisms.
Methods
To investigate the effects of dynorphin on the VP, we conducted behavioral experiments after microinjection of drugs or shRNA and brain‐slice electrophysiological recordings. Histological tracing and molecular biological experiments were used to identify the distribution of KORs and the possible sources of dynorphin projections to the VP.
Results
An elevated dynorphin concentration and increased KOR activity were observed in the VP after acute stress. Infusion of dynorphin‐A into the VP produced depressive‐like phenotypes including anhedonia and despair and anxiety behaviors, but did not alter locomotor behavior. Mechanistically, dynorphin had an inhibitory effect on VP neurons—reducing their firing rate and inhibiting excitatory transmission—through direct activation of KORs and modulation of downstream G‐protein‐gated inwardly rectifying potassium (GIRK) channels and high‐voltage gated calcium channels (VGCCs). Tracing revealed direct innervation of VP neurons by dynorphin‐positive projections; potential sources of these dynorphinergic projections include the nucleus accumbens, amygdala, and hypothalamus. Blockade of dynorphin/KOR signaling in the VP by drugs or viral knock‐down of KORs significantly reduced despair behavior in rats.
Conclusions
Endogenous dynorphinergic modulation of the VP plays a critical role in mediating depressive reactions to stress.
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DOBA, FSPLJ, FZAB, GIS, IJS, IZUM, KILJ, NLZOH, NUK, OILJ, PILJ, PNG, SAZU, SBCE, SBMB, SIK, UILJ, UKNU, UL, UM, UPUK
•Petrogenesis of highly-fractionated I-type granites.•Mineral component and whole rock geochemistry show crystal fractionation.•Zircon U–Pb age and Hf–O isotopes constrain on mantle–crust ...interaction.•Large volume of Jurassic granites in the coastal of southeast China.
Whole-rock geochemical and Sr–Nd–Hf isotopic data and zircon in situ U–Pb ages and Hf–O isotopes are reported for twelve granitic intrusions from inland to coastal areas of the Cathaysia Block, Southeast (SE) China, in order to constrain their magma sources and petrogenesis. They are mainly composed of biotite granites with minor granodiorites. Zircon U–Pb dating by LA-ICPMS and SIMS methods gave emplacement ages of 165–154Ma for these rocks, which are metaluminous to weakly peraluminous (A/CNK=0.95–1.10), with variable SiO2 contents and high K2O contents. They are all depleted in high field strength elements (HFSEs) and enriched in light rare earth elements (LREEs) and large ion lithophile elements (LILEs), and show negative Sr, Ba and Eu anomalies in the spidergrams. Petrographic and geochemical features suggest the granodiorites that contain hornblende to be typical of I-type, while the biotite granites without hornblende are fractionated I-type granites. Their variable major and trace element concentrations are due to fractional crystallization of feldspar, biotite, hornblende, and accessory minerals, including apatite, allanite and monazite. Moreover, our data indicate significant variations in isotopic compositions of these granitoids from inland to coastal areas. The inland granites, from the Lapu, Fogang, Xinfengjiang and Baishigang plutons, have relatively high initial 87Sr/86Sr ratios (0.7105–0.7155) and low εNd(t) (−11.2 to −7.3) and εHf(t) (−10.9 to −6.3) values for whole rocks, and variable δ18O values of 7.69–9.25‰ and εHf(t) values of −13.5 to −6.7 for zircons. In contrast, the coastal granites, from the Longwo, Wushikeng, Lianhuashan, Shigushan, Chiliao, Hulutian, Mantoushan and Fenghuang plutons, show relatively low initial 87Sr/86Sr ratios (0.7056–0.7110) and high εNd(t) (−7.6 to −6.2) and εHf(t) (−6.5 to −2.8) values for whole-rocks, together with εHf(t) values of −7.2 to 3.9 and δ18O values of 6.69–8.38‰ for zircons. The spatial isotopic variations suggest that these Jurassic granitoids were generated by different-percentage mixing of mantle- and ancient (Paleoproterozoic) crust-derived magmas, with subsequently minor crustal assimilation. Our results highlight that Jurassic fractionated I-type granites occur widely from inland to coastal areas of SE China, arguing against the previous view that Jurassic granites occur only in inland while coastal granites are mainly Cretaceous. The widespread occurrence of Jurassic granitoids in SE China is attributed to ascending of mantle-derived magmas, which provide heat for partial melting of lower crustal materials, in an extensional setting.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
Whole-rock geochemical and Sr–Nd–Hf isotopic data and in situ zircon U–Pb and Hf–O isotopes have been determined for mafic (gabbro and diorite) and felsic (I- and A-type granites) rocks from the ...Zhangzhou batholith in southeastern (SE) China, in order to constrain their source and petrogenesis. The batholith consists of gabbro, diorite, granodiorite, monzogranite and alkali feldspar granite, with mafic microgranular enclaves in the monzogranite. Zircon SIMS and LA–ICP–MS U–Pb dating gives consistent emplacement ages of 107–97Ma for these rocks, establishing that the mafic and felsic magmas were coeval. The gabbros and diorites have relatively high MgO contents (up to 5.2wt.%) at low silica concentrations (up to 49.9wt.%), with relatively homogeneous whole-rock initial 87Sr/86Sr ratios (~0.706), negative εNd(t) values of −3.4 to −2.7, chondrite-like εHf(t) values of −0.3 to +0.5, zircon εHf(t) values of −0.8 to +3.2 and δ18O values of +5.0 to +6.1‰, indicating that they were derived by partial melting of an enriched subcontinental lithospheric mantle, coupled with olivine and pyroxene fractionation. The calc-alkaline granodiorites and monzogranites are metaluminous and have relatively high SiO2 and low MgO contents. They have whole-rock initial 87Sr/86Sr ratios of 0.706, εNd(t) ratio of −3.0 to −4.0, εHf(t) values of −2.0 to +0.3 and zircon εHf(t) values of −4.4 to +0.3, with Nd and Hf model ages of about 1.3Ga, indicating that they were mainly derived by partial melting of old continental crustal materials. The alkali feldspar granites have geochemical features similar to A-type granite, with relatively high K2O+Na2O and Nb contents and FeO/MgO and Ga/Al ratios. They have distinct isotopic compositions from the associated mafic rocks, with εNd(t) values of −4.9, εHf(t) values of −3.2 to −3.5, zircon εHf(t) values of −5.1 to +1.0 and δ18O values of +5.1‰ to +6.3‰. They are depleted in Sr, Ba and Eu, indicating that they were mainly derived from partial melting of crustal materials with plagioclase in the residue. Field observations, as well as the petrographic and geochemical data, suggest that the mafic and felsic rocks in the Zhangzhou batholith- were the result of mixing between lithospheric mantle-derived and crustally-derived magmas, coupled with crystal fractionation, in an extensional setting related to Cretaceous subduction of the Paleo-Pacific Plate.
► Cretaceous magmatism in Southeast China related to extension. ► Zircon Hf–O isotopes show multiple sources in the origin of Cretaceous magmatism. ► Petrogenesis of Cretaceous I- and A-type granites in Southeast China. ► The role of mantle-derived magma in petrogenesis of A- and I-type granites.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
In this work, we report the geochemical, whole-rock Sr-, Nd-, and Hf-isotopes, and zircon U–Pb age and Hf–O isotopic compositions for six granitic intrusions in northeastern Fujian, coastal region of ...southeastern China, to elucidate the petrogenesis of aluminous and peralkaline A-type granites in this region. Zircon U–Pb dating of these rocks (including porphyritic syenites, porphyritic granites, alkali-feldspar granites, and arfvedsonite granites) yielded Late Cretaceous ages of 94–98 Ma. Mineral assemblage and geochemical features suggested that the arfvedsonite granites were peralkaline A-type but the porphyritic syenites, porphyritic granites, and alkali-feldspar granites were aluminous A-type. Geochemical data, whole-rock Nd–Hf isotopes (εNd(t) = −5.5 to −4.0, εHf(t) = −3.6 to 0), and the zircon Hf–O isotopes (εHf(t) = −3.0 to +1.4, δ18O = 5.4‰–6.0‰) indicated that the porphyritic syenites were produced by partial melting of crustal rocks in the lower crust. The porphyritic granites and alkali-feldspar granites had similar geochemical features and zircon Hf–O isotopic composition with the porphyritic syenites, suggesting that they were formed by feldspar-dominant crystal fractionation of deep crust derived syenitic magma under shallow crustal level. Compared with the aluminous A-type granites, the peralkaline A-type granites had lower abundance of Al2O3, MgO, CaO, Ba, and Sr, higher abundance of SiO2 and HFSE, as well as higher ratio of total FeO/MgO, Ga/Al, and Rb/Sr. However, the whole-rock Nd-, Hf- and zircon Hf–O isotopic compositions of the peralkaline and aluminous A-type granites were similar. It could be inferred that the peralkaline A-type granites were formed by crystal fractionation of aluminous A-type granitic magmas. Since the studied A-type granitic intrusions were coeval with the bimodal volcanic rocks and the extensional basins in the coastal region of southeastern China, they were likely produced in an extensional setting, possibly during lithospheric thinning that resulted from the subduction of the paleo-Pacific plate beneath southeastern China.
•Aluminous and peralkaline A-type granites were crystallized at 94–98 Ma.•Aluminous and peralkaline A-type granites were derived from a common source.•Aluminous A-type granite was produced by partial melting of lower crustal rocks.•Peralkaline A-type granite was formed via crystal fractionation.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
T helper 17 (Th17) cells are a subset of CD4
T helper cells involved in the inflammatory response in autoimmunity. Th17 cells secrete Th17 specific cytokines, such as IL-17A and IL17-F, which are ...governed by the master transcription factor RoRγt. However, the epigenetic mechanism regulating Th17 cell function is still not fully understood. Here, we reveal that deletion of RNA 5-methylcytosine (m
C) methyltransferase Nsun2 in mouse CD4
T cells specifically inhibits Th17 cell differentiation and alleviates Th17 cell-induced colitis pathogenesis. Mechanistically, RoRγt can recruit Nsun2 to chromatin regions of their targets, including Il17a and Il17f, leading to the transcription-coupled m
C formation and consequently enhanced mRNA stability. Our study demonstrates a m
C mediated cell intrinsic function in Th17 cells and suggests Nsun2 as a potential therapeutic target for autoimmune disease.
The aim of this study was to distinguish the characteristics of intervertebral disc degeneration (IVDD) originating from mechanics imbalance, biology disruption, and their communion, and to develop a ...composite IVDD model by ovariectomy combined with lumbar facetectomy for mimicking elderly IVDD with osteoporosis and lumbar spinal instability. Mice were randomly divided into four groups and subjected to sham surgery (CON), ovariectomy (OVX), facetectomy (mechanical instability, INS) or their combination (COM), respectively. Radiographical (
n
= 4) and histological changes (
n
= 8) of L4/5 spinal segments were analyzed. Tartrate-resistant acid phosphatase (TRAP) staining was conducted to detect osteoclasts, and expression of osterix (OSX), type I collagen (Col I), type II collagen (Col II) and vascular endothelial growth factor (VEGF) were evaluated by immunochemistry. OVX affected the body's metabolism but INS did not, as the body weight increased and uterus weight decreased in OVX and COM mice compared to CON and INS mice. OVX, INS, and COM caused IVDD in various degrees at 12 weeks after surgery. However, the major pathogeneses of OVX- and INS-induced IVDD were different, which focused on endplate (EP) remodeling and annulus fibrosus (AF) collapse, respectively. OVX induced osteopenia of vertebra. In contrast, INS promoted the stress-adaptive increase of subchondral bone trabeculae. The COM produced a reproducible severe IVDD model with characteristics of sparse vertebral trabeculae, cartilaginous EP ossification, subchondral bone sclerosis, fibrous matrix disorder, angiogenesis, disc stiffness, as well as space fusion. Additionally, all groups had elevated bone and cartilage turnover compared with CON group, as the quantity of trap + osteoclasts and the osteogenic OSX expression increased in these groups. Likewise, the VEGF expression levels were similar, accompanied by the altered matrix expression of disc, including the changed distribution and contents of Col II and Col I. The findings suggested that the composite mouse model to some extent could effectively mimic the interactions of biology and mechanics engaged in the onset and natural course of IVDD, which would be more compatible with the IVDD of elderly with vertebral osteoporosis and spinal instability and benefit to further clarify the complicated mechanobiological environment of elderly IVDD progression.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OBVAL, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
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