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AbstractAlthough pegmatites are volumetrically minor in the upper continental crust, these rocks host abundant rare metal deposits (e.g., Li, Be, Rb, Ta, and Nb). Pegmatites can be formed either by extensive fractional crystallization of granitic magmas or by low-degree partial melting of metasedimentary rocks. The Mao’ershan–Yuechengling composite batholith in the Nanling Range in the South China Block (SCB) is of early Paleozoic–Triassic age (440–381 and 236–204 Ma, respectively). Recently, hundreds of pegmatites associated with Nb, Ta, Be, Rb, and Li mineralization have been identified in this batholith. These pegmatites are hosted by granitic wall rocks. However, the relationships between the pegmatites and granitic wall rocks are not well constrained. To address this, we investigated the Mao’antang (MAT) and Tongzuo (TZ) pegmatites and their biotite granite wall rocks in the middle part of the Yuechengling pluton. Laser ablation inductively coupled plasma mass spectrometry zircon U–Pb ages revealed that the MAT pegmatites formed during the Permian (269 Ma) and Triassic (231 Ma) and that the MAT biotite granite wall rock records two stages of magmatic activity (271 and 231 Ma) that are coeval with the pegmatites. The TZ pegmatites probably formed during the Triassic (235 Ma), and the TZ biotite granite wall rock formed during the Silurian (435 Ma). The MAT biotite granite and pegmatites (εNdt=−12.0 to −10.6; εHft=−8.0 to −1.0), TZ pegmatites (εNdt=−10.4 to −6.1), and TZ biotite granites (εNdt=−9.1 to −8.7; εHft=−7.7 to −4.1) have enriched whole-rock Nd and zircon Hf isotopic compositions that are similar to those of early Paleozoic and Triassic S-type granites in the SCB. In addition, the whole-rock Pb isotopic compositions of the MAT and TZ pegmatites and granites are distributed along the upper crust evolution line. We suggest that the MAT and TZ biotite granites were mainly derived from Paleoproterozoic metasedimentary rocks in the middle crust. The MAT pegmatites are fractional crystallization products of the MAT biotite granites, whereas the TZ pegmatites were formed by fractional crystallization of hidden parental S-type granites. We propose that the MAT and TZ pegmatites have potential for rare metal (Nb, Ta, Be, and Li) mineralization, as they record high degrees of fractional crystallization. The MAT and TZ areas in the middle of the Yuechengling pluton are promising targets for rare metal exploration.

The Jiangnan orogenic belt is located between the Yangtze and Cathaysia blocks in South China and is one of the largest W–Sn–Nb–Ta ore belts worldwide. Mineralization occurred from the Proterozoic to Mesozoic, but Caledonian Sn mineralization has rarely been reported. The Jialong cassiterite–sulfide deposit is located in the western Jiangnan orogenic belt. It is hosted by the Sibao Group and in contact with the northeastern part of the Yuanbaoshan granite. The deposit was overprinted by the Sirong ductile shear zone. Here, we present cassiterite U–Pb and mylonitic granite muscovite 40Ar/39Ar ages for this deposit. The cassiterite and muscovite yielded concordant U–Pb and 40Ar/39Ar ages of 422–420 Ma, indicating that Sn mineralization occurred during the early Paleozoic and was spatially and temporally related to the ductile shear zone. The cassiterite is depleted in Nb (0.51–5.46 ppm), Ta (0.01–1.09 ppm), Ti (32.84–423.15 ppm), Sc (0.02–1.45 ppm), Hf (0–1.11 ppm), and other high-field-strength elements. Elements, such as Pb (0.01–8.11 ppm) and Sb (9.92–56.45 ppm), are relatively enriched in the cassiterite, which indicate the Jialong deposit was not directly related to magmatism. Shearing along the Sirong ductile shear zone occurred at 419.6 ± 3.8 Ma, concurrent with the formation of the Jialong Sn–Cu deposit. Moreover, cassiterite in the deposit exhibits obvious shear and brittle deformation, and dissolution and regrowth, suggesting that Sn mineralization was closely related to ductile shearing. The Sirong ductile shear zone and secondary shear structures had a key role in controlling the Sn orebody. The heat generated during tectonic deformation in the ductile shear zone may have produced the ore-forming hydrothermal fluids, and NW–SE-trending fractures in the strata provided the space for mineralization. Metamorphic hydrothermal fluids generated by Caledonian shear deformation extracted Sn from Sn-rich strata, which then migrated along interlayer fractures produced by shearing. A decrease in pressure and water–rock reactions led to the mineralization of Sn and other elements. This deposit is the first example of Caledonian and shear zone-related Sn mineralization identified in the Jiuwandashan area of northern Guangxi.

Abstract Background Concurrent chemoradiotherapy is considered curative intent treatment for patients with non-operative esophageal cancer. Radiation-induced heart damage receives much attention. We performed repeated four-dimensional computed tomography (4DCT) to detect changes in cardiac volume during radiotherapy for esophageal cancer patients, and explored potential factors responsible for those changes. Methods Forty-six patients with esophageal cancer underwent enhanced 4DCT and three-dimensional (3D) CT scans before radiotherapy and every 10 fractions during treatment. The heart was contoured on 3DCT images, 4DCT end expiratory (EE) images and 4DCT maximum intensity projection (MIP) images by the same radiation oncologist. Heart volumes and other relative parameters were compared by the SPSS software package, version 19.0. Results Compared with its initial value, heart volume was smaller at the 10th fraction (reduction = 3.27%, 4.45% and 4.52% on 3DCT, EE and MIP images, respectively, p

Slab breakoff can explain the postcollisional igneous and metamorphic events in many collisional orogens and triggers the transition from initial continental collision to deep subduction. However, the relationship between the deep-seated geometry of slab breakoff and shallow tectono-magmatic events remains unclear. In this study, we report new geochronological, geochemical, and Hf isotope data for granitic rocks from the Qiangtang block. Three granitic samples yielded zircon U-Pb ages of 226-214 Ma and mostly gave negative zircon εHf(t) values of -20.1 to +0.57. These granitoids are K-rich, calc-alkaline, magnesian, and metaluminous to weakly peraluminous. We propose that the granites were generated by partial melting of compositionally heterogeneous lower crust in the Southern Qiangtang block. Our new data, along with previously published data for igneous and metamorphic rocks in the Qiangtang block, suggest that the Longmu Co--Shuanghu suture zone represents a remnant of the closure of the Paleo-Tethys Ocean, and that the Late Triassic tectono-magmatic evolution was controlled by slab breakoff after continental collision. The contrasting magmatic and metamorphic ages show that the two stages of tectono-magmatic activity in the Late Triassic were due to a change in the subduction angle of the continental lithosphere from steep (225-215 Ma) to shallow (215-205 Ma) during slab breakoff. Furthermore, we infer that slab breakoff of the oceanic lithosphere caused extensive crustal melting and reworking and initiated far-field subduction. Our results provide new insights into the slab breakoff processes that control the geometry of subducting continental lithosphere and related postcollisional magmatic and metamorphic events in collision zones. [ABSTRACT FROM AUTHOR]

A suite of subduction-related early Triassic igneous rocks crops out in the Pingxiang area of the DianQiong suture (DQS) in southwest China; this suite represents an important geological record of subduction and closure of the Paleo-Tethys Ocean. In this study, we report geochronological, geochemical, and NdHf isotope data for newly discovered rhyolites and biotite granites in the Pingxiang area. We use these data to constrain their emplacement ages, origins, and geodynamic implications. Zircon U-Pb dating indicates that the rhyolites and biotite granites were emplaced at 251–250 Ma and 249 Ma (early Triassic), respectively. The rhyolites and biotite granites have elevated FeOT/(FeOT + MgO) (0.78–0.89) and 10,000 × Ga/Al (2.83–4.11) ratios, with geochemical affinities to A2-type granites. These rocks are enriched in some large-ion lithophile elements (e.g., Rb, Th, and Ba) and depleted in high-field-strength elements (e.g., Nb, Ta, and Ti), indicating their formation in a subduction-related arc. The rhyolites and biotite granites have negative whole-rock εNd(t) (−11.5 to −9.7) and zircon εHf(t) (−14.5 to −6.2) values, suggesting that these magmas were derived from an ancient crust-dominated source. Geochemical and Nd isotope data reveal that the peraluminous A2-type rhyolites and biotite granites were derived by partial melting of felsic crustal rocks under low-pressure and high-temperature conditions. By integrating all the available data with the regional tectonic evolution of the southwestern Youjiang Basin and adjacent regions, we attribute the generation of the peraluminous A2-type rhyolites and biotite granites to the extensional setting that existed during oceanic subduction, which was induced by roll-back of the Paleo-Tethys oceanic lithosphere at 251–249 Ma. This study indicates that subduction-related magmatism related to Paleo-Tethys oceanic lithosphere was still active in the early Triassic. [ABSTRACT FROM AUTHOR]

In this paper, the nonlinear dynamics equations of a pure rolling low-noise excavating system with one clearance are derived, and the characters and the factors affecting the response, such as rotating angular velocity, mass center of crank, elastic coefficient in the normal direction and the size of clearance, are discussed. The results show that, the larger the elastic coefficient is, the more stable the system is; the value of the elastic coefficient at clearance has almost no affect on the load torque, whether from the magnitude or fluctuation. When the size of clearance and rotational velocity are increased, the interactive forces will increase, and the maximum value of impact force is increased also. The results provide preference for the design of low-noise system in actual engineering. [ABSTRACT FROM PUBLISHER]

The subduction and demise of an ocean plate are generally recognized as essential processes that result in the reworking and maturation of the continental crust. The northern Lhasa Terrane in central Tibet represents the forefront of the Lhasa-Qiang-tang collision belt following the closure of the Bangong-Nujiang Ocean. Thus, it is a pivotal location to study the transition processes from oceanic lithosphere subduction to continental collision as well as pertinent crustal growth mechanisms. Here, we present zircon U-Pb dating, whole-rock major and trace element and Sr-Nd isotope, and zircon Hf isotope and trace element data of the Mendang igneous complex, Baingoin County, northern Lhasa Terrane. Geochro-nological results show that the granodiorites, trachydacites, and rhyolites in the Mendang igneous complex formed at ca. 122-116 Ma, 97 Ma, and 73 Ma, respectively. The Early Cretaceous granodiorite samples are peraluminous with high SiO2, Al2O3, and K2O contents, and moderate A/CNK (molar ratio of Al2O3/[CaO + Na2O + K2O]) values, which are similar to those of typical felsic peraluminous I-type granites. The granodiorites are characterized by enrichment in light rare earth elements and large ion lithophile elements (e.g., Rb) and depletion in high field strength elements (e.g., Nb, Ta). They also show the most enriched whole-rock Sr-Nd [(87Sr/86Sr)i = 0.7072-0.7078; eNd(t) = -7.60 to -5.08] and zircon Hf [eHf(t) = -4.46 to +1.02] isotope compositions, indicating that the Early Cretaceous granodiorites were likely derived from an ancient basement under a subduction setting. The trachy-dacites have uniform SiO2, high Al2O3, Sr contents, and Sr/Y values, and low Y and Yb contents, belonging to adakitic rocks. They show more depleted whole-rock Sr-Nd [(87Sr/86Sr)i = 0.7065-0.7066; eNd(t) = -0.56 to -0.22] and zircon Hf [eHf(t) = 4.36-7.84] isotopes than the granodiorites, suggesting that the trachydacites may have generated from partial melting of the juvenile thickened lower continental crust. The rhyolites have the highest SiO2 and K2O contents in the Mendang igneous complex, and significant depletion of Ba, Sr, Eu, P, and Ti. They have slighter more enriched whole-rock Nd [eNd(t) = -3.71 to -1.16] and zircon Hf [eHf(t) = 1.03-4.31] isotope compositions than the trachydacites. These features suggest that the rhyolites were highly fractionated products of the crustal melts. Wholerock Sr-Nd and zircon Hf isotopes of the Mendang igneous complex show a kink trend from enrichment to depletion and then transfer to enrichment again, signifying an increased contribution of juvenile materials in the northern Lhasa Terrane toward progressively replacing the ancient lower crust and accumulating to newly formed crust. The estimated crustal thickness beneath the northern Lhasa Terrane shows a sharp increase from the Early to Late Cretaceous and peak at ca. 97 Ma, whereas it largely decreases in the Late Cretaceous. Integrated with previous studies, we propose that the formation of the Mendang igneous complex (122-73 Ma) elaborately documents the regional tectonic transition from oceanic lithosphere subduction to demise as well as continental crustal differentiation and maturation. The rollback and breakoff of the southward subducted Bangong-Nujiang oceanic slab in the Early Cretaceous initiated diverse magmatism in the northern Lhasa Terrane. During the early Late Cretaceous, the widespread ada-kitic and Mg-rich magmatism was attributed to the delamination of the thickened lithosphere following the final amalgamation of the Lhasa and Qiangtang Terranes. In the late Late Cretaceous, post-collisional extension induced the formation of the rhyolites in the northern Lhasa Terrane. The growth and destruction of the continental crust had certain tempos from the oceanic lithosphere subduction to continental post-collision stage. [ABSTRACT FROM AUTHOR]

为建立花生球蛋白致敏原的免疫学快速检测方法,采用碱溶酸沉法提取花生球蛋白，经SDS-PAGE检测蛋白纯度后，免疫5只6~8周龄的Balb/c雌性小鼠制备花生球蛋白鼠源多克隆抗体（多抗）血清，并进行免疫学特性鉴定。结果表明：免疫结束后得到的5个多抗血清效价均在1∶ 51 200 以上，均具有一定的敏感性，其中2号小鼠的多抗血清敏感性较好，半数抑制浓度为320 ng/mL；制备的多抗血清特异性较强，2号小鼠的多抗血清与伴花生球蛋白、大豆球蛋白、β-伴大豆球蛋白、牛血清白蛋白、麦朊蛋白、乳清蛋白的交叉反应率均较低，在0.5%以下；Western blot鉴定结果表明成功制备出了花生球蛋白鼠源多克隆抗体。综上，获得了效价高、敏感性强、特异性优良的花生球蛋白鼠源多克隆抗体，为其单克隆抗体的制备及免疫学快速检测方法研究奠定了基础。 In order to establish a rapid immunological detection method for the arachin allergens,the arachin was extracted by alkali solution and acid precipitation method, and its purity was detemined by SDS-PAGE, and 5 Balb/c female mice aged 6 to 8 weeks were immunized to prepare the arachin mouse-derived polyclonal antiserum,the polyclonal antiserum immunological characteristics were identified. The results showed that the titers of the polyclonal antiserum obtained after the end of immunization were all above 1∶ 51 200, and all of them had certain sensitivities, among which the polyclonal antiserum from 2# mouse had the best sensitivities, with a half-inhibitory concentration of 320 ng/mL.The polyclonal antiserum from 2# mouse was not sensitive to conarachin, glycinin, β-conglycinin, bovine serum albumin, gluten protein, and skimmed milk powder,and the cross-reaction rate was low(all below 05%),indicating that the specificity of the polyclonal antiserum prepared was relatively strong. Western blot experiment results indicated the successful preparation of arachin mouse-derived polyclonal antiserum. In conclusion, a arachin mouse-derived polyclonal antibody with high titer, strong sensitivity and excellent specificity is obtained, which provide the material foundation for the preparation of monoclonal antibodies and the research of rapid immunological detection methods.

Abstract Background To explore the differences and correlations between the target volumes defined using preoperative prone diagnostic magnetic resonance imaging (MRI) and postoperative prone computed tomography (CT) simulation imaging based on deformable image registration (DIR) for external-beam partial breast irradiation (EB-PBI) after breast-conserving surgery (BCS). Methods Eighteen breast cancer patients suitable for EB-PBI were enrolled. Preoperative prone diagnostic MRI and postoperative prone CT scan sets for all the patients were acquired during free breathing. Target volumes and ipsilateral breast were all contoured by the same radiation oncologist. The gross tumor volume (GTV) delineated on the preoperative MRI images was denoted as the GTVpreMR and the tumor bed (TB) delineated on the postoperative prone CT images was denoted as the GTVpostCT. The MIM software system was used to deformably register the MRI and CT images. Results When based on the coincidence of the compared target centers, there were statistically significant increases in the conformity index (CI) and degree of inclusion (DI) values for GTVpostCT-GTVpreMR, GTVpostCT-CTVpreMR + 10, CTVpostCT + 10-GTVpreMR, and CTVpostCT + 10-CTVpreMR + 10 when compared with those based on the DIR of the thorax (Z = − 3.724, − 3.724, − 2.591, − 3.593, all P