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The Qinling Orogen is a composite orogenic belt that can be subdivided into the North and South Qinling, broadly separated by the Shangdan suture zone. These two orogenic belts were generated by subduction-collisional processes in the Early Paleozoic and Late Triassic, respectively. During the Late Jurassic to Early Cretaceous, the eastern portion of the Qinling Orogen was tectonically reactivated due to westerly subduction of the Izanagi plate underneath the East China continental margin. The Qinling Orogen is well-endowed with numerous Au, Mo, Ag-Pb-Zn deposits that predominantly formed in the Late Triassic to Early Cretaceous, with rare Paleozoic varieties documented. In this study, we present garnet and zircon U-Pb dating results to show that the Huoshenmiao iron skarn deposit in the Tongbai area of North Qinling orogenic belt formed in the Early Silurian and is genetically related to subduction-related magmatism. The Huoshenmiao deposit consists of lenticular and stratiform orebodies that contain massive or densely disseminated magnetite variably associated with garnet, diopside, epidote, hornblende, and actinolite. Garnets from iron ores are andradite and grossular in composition (Ad83.1Gr13.3-Ad86.5Gr10.2) and characterized by enrichment in light rare earth elements (ΣLREE=57.85–103.82 ppm) and depletion in heavy rare earth elements (ΣHREE=5.50–11.34 ppm), with significantly positive Eu and Ce anomalies (δEu of 1.09–1.89 and δCe of 1.39–1.69). These compositional signatures are distinctly different from those of garnets in the ore-hosting metamorphic rocks that are typically dominated by almandine, spessartine and grossular (Al47.4Sp30.4Gr13.8-Al51.9Sp24.8Gr17.6), depleted in LREE (0.14–0.69 ppm), enriched in HREE (95.68–841.60 ppm) and have pronounced negative Eu anomalies (δEu=0.24–0.51). In addition, garnets from iron ores of the Huoshenmiao deposit contain abundant daughter mineral-bearing, multiphase fluid inclusions, further confirming their hydrothermal origin. Two samples of those hydrothermal garnets yield U-Pb dates of 437±9 Ma and 437±10 Ma (2σ), revealing a Paleozoic mineralization event that has long been ignored and rarely documented. These garnet dates agree well with zircon U-Pb dates of 438±4 Ma to 436±3 Ma for a gabbroic diorite and 430±4 Ma for a granite intrusion in close proximity of the mine, supporting a possible genetic link between the iron mineralization and Early Silurian magmatism. The Paleozoic intrusions are enriched in large ion lithophile elements (LILEs: Ba, K, Sr) and LREEs, depleted in high field strength elements (HFSEs: Nb, Ta, P, Ti), have whole-rock (87Sr/86Sr)i, eNd(t), and zircon eHf(t) values of 0.7039–0.7042, 3.32–4.33, and 13.0–14.9, respectively. These geochemical and isotopic characteristics suggest that the Paleozoic intrusions were affiliated with arc magmatism triggered by subduction of the Shangdan oceanic plate in the Early Paleozoic. Recognition of the Silurian Huoshenmiao iron skarn deposit opens a new window for exploration of Paleozoic mineral resources in the Tongbai area and other portions of the North Qinling Orogen.

Blending effect of color blended yarns, which plays a critical important role to the fabrics styles, is affected by yarn structure, spinning processes, and blending methods. In this study, color blended viscose yarns were produced by compact ring spinning, rotor spinning and air-jet vortex spinning with single-passage and three-passage color-blended slivers. The blending effect of these yarns was evaluated by Hamilton transfer index. Additionally, yarn performance was tested, compared and analyzed, including strength, hairiness and evenness. Results show that the blending effect of the rotor spun yarns is the best with both types of slivers. Even though such yarns have wrap fibers on the surface like the air-jet vortex yarns, the yarn structures are different. Compared to the tightly wrapped fiber on the rotor-spun yarns, wrapped fibers form a shield on core fibers of the air-jet vortex yarns. Among the three types of yarns, compact ring yarns have higher mean value of evenness and its value also changes with the passage number of sliver, yarn linear density and the spinning method. Hairiness of air-jet vortex yarn is the lowest, followed by rotor spun yarn and then the compact ring-spinning yarn. While physical performance such as tenacity, breaking elongation, and break work of compact-ring-spinning yarns are the greatest among the three types of yarns.

This paper has designed an anchor point lever beam coupled tuning fork micro-gyroscope and tested its output performance. The tuning fork micro-gyro is designed to eliminate the output error caused by orthogonal coupling and in-phase-inverting coupling by structural decoupling and electrical decoupling, and can improve the anti-vibration performance and the modal optimization ability. It has derived the dynamic response working model of the non-ideal tuning fork micro-gyroscope, and optimized the structural parameters of the micro-gyroscope by simulation analysis. The microstructure processing has been realized by the SOI-MEMS process, sealed the processed structural prototype, and tested the performance through the established experimental system. According to the test results, the designed micro-gyroscope driving direction has greatly reduced the in-phase-inverting coupling through the anchor coupling lever beam, and the detection direction effectively suppressed the in-phase-inverting coupling through the stiffness matching electrode. While closed-loop detecting, the measured Aallan variance zero-bias stability is 1.779°/h, and the 1σ zero-bias stability is 8.3°/h. While applying a stiffness matching voltage, the measured vibration sensitivity is 23.9°/h/g.

Background Converting carbon dioxide (CO2) into value-added chemicals using engineered cyanobacteria is a promising strategy to tackle the global warming and energy shortage issues. However, most cyanobacteria are autotrophic and use CO2 as a sole carbon source, which makes it hard to compete with heterotrophic hosts in either growth or productivity. One strategy to overcome this bottleneck is to introduce sugar utilization pathways to enable photomixotrophic growth with CO2 and sugar (e.g., glucose and xylose). Advances in engineering mixotrophic cyanobacteria have been obtained, while a systematic interrogation of these engineered strains is missing. This work aimed to fill the gap at omics level. Results We first constructed two engineered Synechococcus elongatus YQ2-gal and YQ3-xyl capable of utilizing glucose and xylose, respectively. To investigate the metabolic mechanism, transcriptomic and metabolomic analysis were then performed in the engineered photomixotrophic strains YQ2-gal and YQ3-xyl. Transcriptome and metabolome of wild-type S. elongatus were set as baselines. Increased abundance of metabolites in glycolysis or pentose phosphate pathway indicated that efficient sugar utilization significantly enhanced carbon flux in S. elongatus as expected. However, carbon flux was redirected in strain YQ2-gal as more flowed into fatty acids biosynthesis but less into amino acids. In strain YQ3-xyl, more carbon flux was directed into synthesis of sucrose, glucosamine and acetaldehyde, while less into fatty acids and amino acids. Moreover, photosynthesis and bicarbonate transport could be affected by upregulated genes, while nitrogen transport and assimilation were regulated by less transcript abundance of related genes in strain YQ3-xyl with utilization of xylose. Conclusions Our work identified metabolic mechanism in engineered S. elongatus during photomixotrophic growth, where regulations of fatty acids metabolism, photosynthesis, bicarbonate transport, nitrogen assimilation and transport are dependent on different sugar utilization. Since photomixotrophic cyanobacteria is regarded as a promising cell factory for bioproduction, this comprehensive understanding of metabolic mechanism of engineered S. elongatus during photomixotrophic growth would shed light on the engineering of more efficient and controllable bioproduction systems based on this potential chassis.

Magmatic-hydrothermal gold–copper deposits in post-subduction settings represent essential targets for mineral exploration, but controls on their formation remain controversial. The early Cretaceous lode Au districts that formed during lithosphere destruction of the North China Craton provide an ideal opportunity to better understand the key tectono-magmatic factors responsible for the genesis of Au-rich deposits in post-subduction settings. Here, we present a LA-ICP-MS study of silicate melt inclusions and sulfide inclusions from ore-related mafic to intermediate rocks in the central Taihangshan Au district in the interior of the North China Craton to constrain the content and evolution of magmatic ore metals ± volatiles. The results, combined with numerical modeling, suggest that the ore-related magmas contained only a few ng/g Au, which is similar to the Au content of non-mineralization-related mafic to intermediate magmas worldwide. The low Au content of the lode Au-related magmas suggest that large volumes of magmas had to accumulate in the middle to lower crust through trans-lithospheric fault systems to produce the lode Au deposits. It is further suggested that the lode Au-related magmas were alkali-rich, hydrous, oxidized and relatively rich in sulfur and chlorine (mafic melt inclusions contain 0.14‒0.24 wt% S and 0.1‒0.2 wt% Cl). These properties are considered critical for the generation of auriferous ore fluids. By comparing the tectono-magmatic setting of the giant Jiaodong Au province (~ 4000 t Au) with the central Taihangshan district (~ 150 t Au), we propose that the much larger total Au tonnage of the Jiaodong district results from the accumulation of a much larger volume of ore-forming magmas at deep crustal levels, induced by a stronger degree of lithosphere modification. In addition, given that the composition of lode Au-related magmas is similar to that of porphyry Cu–Au-related magmas, the lack of giant, early Cretaceous porphyry Cu–Au deposits in the North China Craton suggests that strong extensional settings favor the formation of lode Au deposits instead of porphyry Cu–Au deposits. The present study, therefore, has general implications for the genesis of Au-rich deposits in strongly extensional settings.

Background Part of tuberculosis (TB) patients were missed if symptomatic screening was based on the main TB likely symptoms. This study conducted to compare the yield and relative costs of different TB screening algorithms in active case-finding in the whole population in China. Methods The study population was screened based on the TB likely symptoms through a face-to-face interview in selected 27 communities from 10 counties of 10 provinces in China. If the individuals had any of the enhanced TB likely symptoms, both chest X-ray and sputum tests were carried out for them furtherly. We used the McNemar test to analyze the difference in TB detection among four algorithms in active case-finding. Of four algorithms, two were from WHO recommendations including 1a/1c, one from China National Tuberculosis Program, and one from this study with the enhanced TB likely symptoms. Furthermore, a two-way ANOVA analysis was performed to analyze the cost difference in the performance of active case-finding adjusted by different demographic and health characteristics among different algorithms. Results Algorithm with the enhanced TB likely symptoms defined in this study could increase the yield of TB detection in active case-finding, compared with algorithms recommended by WHO (p Conclusions Active case-finding based on the enhanced symptom screening is meaningful for TB case-finding and it could identify more active TB cases in time. The findings indicated that this enhanced screening approach cost more compared to algorithms recommend by WHO and China NTP, but the increased yield resulted in comparative costs per patient. And it cost much more that only smear/bacteriological-positive TB cases are screened in active case-finding.

In this paper, the competing requirements of material strength, casting formation and residual stress are considered in the design of a large bulkhead integral isothermal forging die using a design approach that incorporates an outer ring plus a die body. Thermal stress assembly was conducted to resolve the various manufacturing issues encountered in the production of this large-scale casting. This paper also proposes a design method for an expansion joint and material-saving holes to homogenize the cross-sectional thickness of the casting die by solving problems associated with defects and hot cracking during the casting process. The finite element method was used based on the equivalent liquid level descending method, the Niyama criterion, etc., to analyze the pouring of the sand model with different risers to choose the casting process. To resolve the occurrence of hot cracks during production, the design was optimized and the process was improved in combining with the simulation analysis result, after which carrying out another finite element analysis and by re-verifying the production process again. The results show that the simulated porosity, shrinkage and stress distribution are in accord with the practical production status. Based on the mechanical properties and a microstructure analysis, the tension strength of the K3 casting die at 950 °C is approximately 635 MPa, and the microstructures are typical dendrites. However, through the simulation, practical production, and analysis of the mechanical properties and microstructure, the die design method proposed in this paper offers benefits in solving casting forming problems and hot cracking of an integral oversized titanium bulkhead casting die, and a K3 superalloy die with a weight of 7.8 tons was successfully cast.

The West Qinling Orogen is endowed with more than 100 sediment-hosted gold deposits with an estimated resource of > 2000 t Au. Previous radiometric dating results have shown that most deposits formed during a Late Triassic to Early Jurassic period of contractional deformation over the orogen. However, here we show that the newly discovered Daqiao gold deposit (> 105 t at 3–4 g/t) in the southern belt of the West Qinling Orogen formed in latest Jurassic to Early Cretaceous under a different tectonic regime. The Daqiao gold deposit is hosted in weakly metamorphosed Triassic turbidites and is spatially associated with hydrothermally altered granodiorite and diorite porphyry dykes. Six granodiorite dykes have similar zircon U–Pb ages ranging from 215.0 ± 1.1 to 211.5 ± 1.5 Ma (1σ), whereas one diorite porphyry dyke has a zircon U–Pb age of 187.5 ± 2.1 Ma (1σ). The age of gold mineralization is constrained by two types of sericite: sericite aggregates coexisting with disseminated auriferous pyrite in relatively high-grade breccia ores and sericite coexisting with auriferous pyrite in weakly mineralized granodiorite dykes. Sericite aggregates from the breccia ores have 40Ar/39Ar plateau ages ranging from 150.7 ± 3.1 to 142.3 ± 2.5 Ma (2σ), whereas grains from the altered granodiorite dykes and low-grade breccia ores have 40Ar/39Ar plateau ages of 130.8 ± 3.1 to 127.2 ± 0.6 Ma (2σ). The 40Ar/39Ar ages thus suggest two periods of gold mineralization in the latest Jurassic and Early Jurassic that are likely related to repeated brecciation at Daqiao. These Jurassic-Cretaceous mineralization ages coincide with discounted ages from several other gold deposits in the region and suggest that there is an underappreciated gold event in the West Qinling Orogen that may not have been associated with the orogenic deformation but is genetically related to the far-field effects of plate reorganization during Paleo-Pacific subduction beneath the eastern Eurasian continent.

The Gutaishan deposit is a slate-hosted lode Au–Sb deposit in the Xiangzhong Sb–Au metallogenic province, South China. The deposit has a proven reserve of ca. 9 -t gold at an average grade of 13-g/t and contains 2500-t Sb. The deposit represents the product of a complex ore-forming process, comprising four different stages, of which the third stage is the main gold–stibnite bearing stage. Scanning electron microscopy, electron probe microanalysis, and laser ablation inductively coupled plasma-mass spectrometry were used to investigate the occurrence of visible gold and the distribution of invisible gold in pyrite and arsenopyrite. Visible gold displays textural complexity with four distinct categories defined and assumed to have formed directly precipitated from ore-forming fluid and remobilized from pyrite and arsenopyrite. Pyrite and arsenopyrite occur as ten and four texturally distinct subtypes; all host invisible gold, which is lattice-bound. Trace element mapping of selected pyrite and arsenopyrite grains reveals a marked compositional zoning with respect to Au and other elements in both minerals. Observed decoupled behavior between Au and As in some grains contradicts the paradigm of coupled Au and As substitution. Evidence suggests that the Gutaishan deposit likely represents an evolving Au–Sb mineralization event recorded by the complex texture and geochemical signatures of visible gold, sulfides, and sulfosalts.

For breast cancer patients, a false-negative rate lower than 10% can be achieved if targeted axillary dissection (TAD) is performed, which includes the excision of both biopsy-proven positive lymph nodes (BxLNs) and sentinel lymph nodes (SLNs). However, little evidence exists on the accuracy of intraoperative touch imprint cytology (ITPC) applied in TAD after neoadjuvant chemotherapy (NAC) for breast cancer patients with initial axillary metastasis. This study aimed to investigate the accuracy of ITPC in TAD after NAC. Breast cancer patients with biopsy-confirmed nodal metastasis were prospectively enrolled in the study. After completion of NAC, all patients underwent TAD followed by axillary lymph node dissection (ALND). Then ITPC was performed to evaluate BxLNs and SLNs. The accuracy of TAD and ITPC was calculated in comparison with hematoxylin and eosin (H&E) staining of ALNs. The results of ITPC during 6 months at our center in the adjuvant setting were used for comparison . Overall, the false-negative rate of TAD was 10.8%. In a test with 92 patients, ITPC had an accuracy of 92.4%, a sensitivity of 87.9%, and a specificity of 94.9%. In the non-NAC group, ITPC showed similar accuracy (91.2%) and specificity (97.9%) but significantly lower sensitivity (68.9%; P = 0.03). The use of ITPC was feasible for TAD among breast cancer patients with biopsy-confirmed axillary metastasis who were treated with NAC. All the misses in the ITPC involved patients with micrometastases or isolated tumor cells. Use of ITPC can help decrease the number of second operations for patients with residual disease in ALNs after NAC.

Uranium–lead isotopes and trace elements of titanite from the Chengchao iron skarn deposit (Daye district, Eastern China), located along the contact zones between Triassic marine carbonates and an early Cretaceous intrusive complex consisting of granite and quartz diorite, were analyzed using laser ablation inductively coupled plasma mass spectrometry to provide temporal constraints on iron mineralization and to evaluate its potential as a reference material for titanite U–Pb geochronology. Titanite grains from mineralized endoskarn have simple growth zoning patterns, exhibit intergrowth with magnetite, diopside, K-feldspar, albite and actinolite, and typically contain abundant primary two-phase fluid inclusions. These paragenetic and textural features suggest that these titanite grains are of hydrothermal origin. Hydrothermal titanite is distinct from the magmatic variety from the ore-related granitic intrusion in that it contains unusually high concentrations of U (up to 2995 ppm), low levels of Th (12.5–453 ppm), and virtually no common Pb. The REE concentrations are much lower, as are the Th/U and Lu/Hf ratios. The hydrothermal titanite grains yield reproducible uncorrected U–Pb ages ranging from 129.7 ± 0.7 to 132.1 ± 2.7 Ma (2σ), with a weighted mean of 131.2 ± 0.2 Ma [mean standard weighted deviation (MSWD) = 1.7] that is interpreted as the timing of iron skarn mineralization. This age closely corresponds to the zircon U–Pb age of 130.9 ± 0.7 Ma (MSWD = 0.7) determined for the quartz diorite, and the U–Pb ages for zircon and titanite (130.1 ± 1.0 Ma and 131.3 ± 0.3 Ma) in the granite, confirming a close temporal and likely genetic relationship between granitic magmatism and iron mineralization. Different hydrothermal titanite grains have virtually identical uncorrected U–Pb ratios suggestive of negligible common Pb in the mineral. The homogeneous textures and U–Pb characteristics of Chengchao hydrothermal titanite suggest that the mineral might be a suitable internal reference material for U–Pb dating.

In this paper, a self-mode-locked Nd:YVO4 picosecond vortex laser is demonstrated, which can operate on the different Laguerre-Gaussian (LG) modes at 1 064 nm. A π/2 mode converter is utilized to realize the picosecond vortex laser with LG mode transformed from the high-order Hermite-Gaussian (HG) mode. For the proposed laser, the mode-locked pulse repetition rate is 1.81 GHz. The average output powers of LG12 mode and LG02 mode are 1.241 W and 1.27 W, respectively, and their slope efficiencies are 23.2% and 24%, respectively.

Background The problem of population aging is a critical public health concern in modern China, and more tuberculosis (TB) control efforts are needed to reach elderly people at high priority. In this study, we aim to determine the prevalence and identify the risk factors of TB among elderly people in China. Methods A multistage cluster-sampled cross-sectional survey was conducted in 2013, and 27 clusters were selected from 10 counties of 10 provinces in China. All consenting participants greater than or equal to 65 years of age were screened for pulmonary TB with a chest X-ray (CXR) and a symptom questionnaire. Three sputum specimens for bacteriological examination by microscopy and culture were collected from those whose screening was positive. Prevalence was calculated, a multiple logistic regression model was performed to confirm the risk factors, and population attributable fraction (PAF) of each risk factor was calculated to indicate the public health significance. Results Of 38 888 eligible people from 27 clusters, 34 269 participants finished both questionnaire and physical examination. There were 193 active pulmonary TB cases, 62 of which were bacteriologically confirmed. The estimated prevalence of active pulmonary TB and bacteriologically confirmed TB in those 65 years of age and older was 563.19 per 100 000 (95% CI: 483.73–642.65) and 180.92 per 100 000 (95% CI: 135.89–225.96), respectively. Male sex, older age, living in rural areas, underweight, diabetes, close contact of pulmonary TB (PTB) and previous TB history are all risk factors for TB. The risk of TB increased with increasing age and decreasing body mass index (BMI) after adjusting for other factors, and there is a positive dose–response relationship. Conclusions In China, active case finding (ACF) could be implemented among elderly people aged 65 and above with underweight, diabetes, close contact history and previous TB history as a priority, which will get significant yields and be cost-effective. Electronic supplementary material The online version of this article (10.1186/s40249-019-0515-y) contains supplementary material, which is available to authorized users.

The Xiahe-Hezuo district in the West Qinling orogen contains numerous Au-(As-Sb) and Cu-Au-(W) deposits. The district is divided into eastern and western zones by the Xiahe-Hezuo Fault. The western zone is exposed at a shallow level and contains sediment-hosted disseminated Au-(As-Sb) deposits, whereas the eastern zone is exposed at a deeper level and contains Cu-Au-(W) skarn and lode gold deposits within or close to granitic intrusions. The Laodou gold deposit in the eastern zone consists of auriferous quartz-sulfide-tourmaline and minor quartz-stibnite veins that are structurally controlled by fault zones transecting the Laodou quartz diorite porphyry stock and enveloped by potassic and phyllic alteration. Both the veins and alteration halos commonly contain quartz, sericite, tourmaline, pyrite, and arsenopyrite, with minor galena, sphalerite, chalcopyrite, tetrahedrite, and enargite. Gold occurs mainly as invisible gold in pyrite or arsenopyrite and locally as inclusions less than 50 μm in diameter. The zircon U-Pb age of 247.6 ± 1.3 Ma (2σ) on the host quartz diorite porphyry and the sericite 40Ar/39Ar plateau ages of 249.1 ± 1.6 and 249.0 ± 1.5 Ma (2σ) on two ore-related hydrothermal sericite samples are within analytical errors of one another. At the formation temperature (275 °C) inferred from microthermometric measurements of fluid inclusion, sericite and tourmaline yield calculated δDH2O values of −70 to −45‰ and δ 18OH2O of 5.8 to 9.7‰, while quartz yields calculated δ 18OH2O values of 5.1∼5.7‰. Hydrothermal tourmaline in quartz-sulfide-tourmaline veins has δ 11B of −11.2 to −0.9‰ (mean of −6.3‰) that are similar to the values of magmatic tourmaline (−8.9 to −5.5‰ with a mean of −6.8‰) in the host quartz diorite porphyry. The δ 34S values of sulfide minerals range from −5.9 to +5.8‰ with a mean of −0.6‰ that is typical of magmatic sulfur. Pyrite from hydrothermally altered quartz diorite porphyry and quartz-sulfide-tourmaline veins have relatively homogeneous lead isotopic compositions, compatible with granitic intrusions in the district. The geochronological and isotopic data combined support a magmatic origin for the Laodou gold deposit, most likely formed from fluids exsolved from the Laodou quartz diorite porphyry or associated intrusive phases at deeper levels beneath the stock. Orogenic and Carlin-like gold deposits in the West Qinling orogen have been commonly thought to have formed from metamorphic fluids. This study, however, highlights the role of magmatic-derived fluids in the formation of lode gold deposits. Synthesis of geochronological, geological, and geochemical data on magmatic rocks and ore deposits in and surrounding the Xiahe-Hezuo district indicates that gold mineralization predominantly occurred within a subduction-related magmatic arc prior to collision between the Yangtze and North China cratons that produced the West Qinling orogen.

The Dongxiangqiao Mn deposit in Hunan Province is one of numerous supergene Mn-oxide deposits in central South China. This deposit is derived from chemical weathering of Permian Mn-rich shales and limestones. Mn-oxide samples from the Dongxiangqiao deposit consist mainly of pyrolusite, lithiophorite, and cryptomelane, with minor amounts of hollandite and nsutite. Cobalt and Ni are enriched in lithiophorite and cryptomelane-hollandite. Our studies suggest that Co occurs mainly in the structural and adsorption sites of lithiophorite. Cobalt in lithiophorite accounts for ~80 % of the bulk Mn-oxide ores, thus it can be comprehensively utilized when lithiophorite has been separated by a suitable physical beneficiation process. Four cryptomelane-dominated grains from the saprolite zone yield 40Ar/39Ar plateau ages ranging from 10.3 ± 0.3 to 4.19 ± 0.08 Ma (2σ). This indicates that intense enrichment of supergene Mn-oxides has prevailed at least in the late Miocene and persisted into the Pliocene at Dongxiangqiao. When combined sedimentalogical and thermochronoloical data, our dating results suggest that central South China has a relatively rapid surface uplift rate.

The Xishimen iron skarn deposit in the Handan-Xingtai district, North China Craton, contains 256 Mt @ 43 % Fe (up to 65 %). The mineralization is dominated by massive magnetite ore along the contact zone between the early Cretaceous Xishimen diorite stock and middle Ordovician dolomite and dolomitic limestones with numerous intercalations of evaporitic beds. Minor lenticular magnetite-dominated bodies also occur in the carbonate rocks proximal to the diorite stock. Hydrothermal alteration is characterized by extensive albitization within the diorite stock and extreme development of magnesian skarn along the contact zone consisting of diopside, forsterite, serpentine, tremolite, phlogopite, and talc. Magmatic quartz and amphibole from the diorite and hydrothermal diopside from the skarns contain abundant primary or pseudosecondary fluid inclusions, most of which have multiple daughter minerals dominated by halite, sylvite, and opaque phases. Scanning electron microscopy (SEM) and laser Raman spectrometry confirm that pyrrhotite is the predominant opaque phase in most fluid inclusions, in both the magmatic and skarn minerals. These fluid inclusions have total homogenization temperatures of 416–620 °C and calculated salinities of 42.4–74.5 wt% NaCl equiv. The fluid inclusion data thus document a high-temperature, high-salinity, ferrous iron-rich, reducing fluid exsolved from a cooling magma likely represented by the Xishimen diorite stock. Pyrite from the iron ore has δ34S values ranging from 14.0 to 18.6 ‰, which are significantly higher than typical magmatic values (δ34S = 0 ± 5 ‰). The sulfur isotope data thus indicate an external source for the sulfur, most likely from the evaporitic beds in the Ordovician carbonate sequences that have δ34S values of 24 to 29 ‰. We suggest that sulfates from the evaporitic beds have played a critically important role by oxidizing ferrous iron in the magmatic-hydrothermal fluid, leading to precipitation of massive magnetite ore. A synthesis of available data suggests that oxidation of Fe2+-rich, magmatic-hydrothermal fluids by external sulfates could have been a common process in many of the world’s iron skarn deposits and other magnetite-dominated ores, such as iron oxide-copper-gold (IOCG) and iron oxide-apatite (IOA) systems.

TiO2 films were prepared on the surface of the diamond particles using a classical sol-gel method. The results showed that the TiO2 covered on the diamond surface as a rough and dense film with anatase phase, and tightly combined with the diamond substrates via the Ti-O-C bond. The initial oxidation temperature and compression strength of diamond were improved to 725 °C and 23.8 N with TiO2 film coated. TiO2 film increased the roughness of the diamond surface, promoted its mutual solubility, and formed the chemical bonding (Ti-O-Si) between the vitrified bond and the diamond. Therefore, the TiO2 film decreased the interface energy of the diamond, and promoted the wetting angle of vitrified bond with diamond to 36.7°. As a result, the TRS of vitrified bond diamond composites was increased to 76.3 MPa.

To achieve reversible immortalization of cells, we design a modified tetracycline-inducible expression (Tet-on) system to conditionally regulate the ectopic expression of human telomerase reverse transcriptase (hTERT) in primary cells. The hTERT gene, hygromycin-resistant gene and all essential elements for achieving tetracycline induction were combined into a single plasmid vector. Sheep fetal fibroblast cells were transfected with the vector and four putative immortalized cell clones were obtained via induction of hTERT expression by doxycycline. These immortalized cells maintained a normal karyotype and showed no transformed phenotype after 250 days continuous culture. When hTERT expression was switched off by withdrawal of doxycycline, the immortalized cells reverted to a normal proliferative state and eventually senesced after limited divisions. This single-plasmid based Tet-on inducible hTERT expression system can be applied for reversible immortalization of animal cells.

Numerous polymetallic volcanogenic massive sulfide (VMS), vein, and replacement deposits are distributed along the Changning–Menglian suture zone in Sanjiang Tethyan metallogenic province, SW China. Laochang is the largest Pb–Zn–Ag vein and replacement deposit in this area, with a proven reserve of 0.51 Mt Pb, 0.34 Mt Zn, and 1,737 t Ag. Its age and relationship to magmatic events and VMS deposits in the region, however, have long been debated. In this paper, we present pyrite Re–Os and titanite U–Pb ages aiming to provide significant insights into the timing and genesis of the Pb–Zn–Ag mineralization. Pyrite grains in textural equilibrium with galena, sphalerite, and chalcopyrite from stratabound Pb–Zn–Ag and Cu-bearing Pb–Zn–Ag orebodies have a Re–Os isochron age of 45.7 ± 3.1 Ma (2σ, mean square weighted deviation (MSWD) = 0.45), whereas titanite grains intergrown with sulfide minerals yield a weighted mean 206Pb/238U age of 43.4 ± 1.2 Ma (2σ, n = 8). A Mo-mineralized granitic porphyry intersected by recent drilling below the Laochang Pb–Zn–Ag ores yields a zircon U–Pb age of 44.4 ± 0.4 Ma (2σ, n = 12). Within analytical uncertainties, the ages of the Pb–Zn–Ag deposit and the concealed Mo-mineralized porphyry are indistinguishable, indicating that they are products of a single magmatic hydrothermal system. The results show that Laochang Pb–Zn–Ag deposit is significantly younger than the host mafic volcanic rock (zircon U–Pb age of 320.8 ± 2.7 Ma; 2σ, n = 12) and Silurian VMS deposits along the Changning–Menglian suture zone, arguing against its origin as a Carboniferous VMS deposit as many researchers claimed. The initial 187Os/188Os ratio (0.540 ± 0.012) obtained from the pyrite Re–Os isochron suggests that metals were likely derived from the granitic porphyry that formed from a hybrid magma due to mixing of crustal- and mantle-derived melts, rather than from the mafic volcanic host rocks as previously thought. Our results favor that the Laochang Pb–Zn–Ag deposit is the shallow product of a porphyry Mo system. Thus, there is potential for discovery of porphyry Mo or Cu–Mo deposits below Laochang and similar Pb–Zn–Ag deposits in the Changning–Menglian suture zone.

In this paper, the antitumor activity of a novel porphyrin-based photosensitizer 5, 10, 15, 20-tetrakis[(5-diethylamino)pentyl] porphyrin (TDPP) was reported in vitro and in vivo. The photophysical and cellular properties of TDPP were investigated. The singlet oxygen generation quantum yield of TDPP was detected ; it showed a high singlet oxygen quantum yield of 0.52. The intracellular distribution of photosensitizer was detected with laser scanning confocal microscopy. The efficiency of TDPP-photodynamic therapy (PDT) in vitro was analyzed by 3-(4, 5-dimethyl-2-thiazolyl)-2, 5- diphenyl-2H-tetrazolium bromide (MTT) assay and in situ trypan blue exclusion test. Treated with a 630-nm laser, TDPP can kill cultured human esophageal cancer cell line (Eca-109) cells and reduce the growth of Eca-109 xenograft tumors significantly in BABL/c nude mice. And histopathological study was also used to confirm the antitumor effect. It has the perspective to be developed as a new antitumor drug in photodynamic therapy and deserves further investigation.

High spatial resolution textural (scanning electron microscope (SEM)), chemical (electron microprobe (EMP)) and laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS)), and sulfur isotopic (secondary ion mass spectrometry (SIMS)) analyses of pyrite from the Qiuling sediment-hosted gold deposit (232 ± 4 Ma) in the West Qinling orogen, central China were conducted to distinguish pyrite types and gain insights into the source and evolution of sulfur in hydrothermal fluids. The results reveal an enormous variation (−27.1 to +69.6 ‰) in sulfur isotopic composition of pyrite deposited during three paragenetic stages. Pre-ore framboidal pyrite, which is characterized by low concentrations of As, Au, Cu, Co, and Ni, has negative δ34S values of −27.1 to −7.6 ‰ that are interpreted in terms of bacterial reduction of marine sulfate during sedimentation and diagenesis of the Paleozoic carbonate and clastic sequences, the predominant lithologies in the deposit area, and the most important hosts of many sediment-hosted gold deposits throughout the West Qinling orogen. The ore-stage hydrothermal pyrite contains high concentrations of Au, As, Cu, Sb, Tl, and Bi and has a relatively narrow range of positive δ34S values ranging from +8.1 to +15.2 ‰. The sulfur isotope data are comparable to those of ore pyrite from many Triassic orogenic gold deposits and Paleozoic sedimentary exhalative (SEDEX) Pb-Zn deposits in the West Qinling orogen, both being hosted mainly in the Devonian sequence. This similarity indicates that sulfur, responsible for the auriferous pyrite at Qiuling, was largely derived from the metamorphic devolatization of Paleozoic marine sedimentary rocks. Post-ore-stage pyrite, which is significantly enriched in Co and Ni but depleted in Au and As, has unusually high δ34S values ranging from +37.4 to +69.6 ‰, that are interpreted to result from thermochemical reduction of evaporite sulfates in underlying Cambrian sedimentary rocks with very high δ34S values. The variations in Au content and sulfur isotopic compositions across a single ore-stage pyrite grain may reflect displacement of indigenous groundwater with low δ34S values by auriferous metamorphic fluids with high δ34S values. The very low-grade metamorphism of the host rocks and the metamorphic derivation of sulfur for the ore pyrite indicate that the Qiuling sediment-hosted gold deposit is an epizonal manifestation of an orogenic gold system in the West Qinling orogen.

In this study, we carried out petrography, zircon U-Pb geochronology and Hf isotopic analyses on a granitic pegmatite dyke in the Xiaoqinling area in southern margin of the North China Craton (NCC). Our study suggests that the pegmatite dyke likely crystallized from a volatile-rich pegmatitic magma. Different from most other pegmatite elsewhere, zircon from this pegmatite dyke does not contain unusually high U and Th concentrations and suffered no evident radioactive damage, therefore we successfully obtained a zircon U-Pb dating using laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS), which yields an average 207Pb/206Pb age of 1 814±6 Ma, representing the intrusive age of the granitic pegmatite dyke. Zircon ɛ Hf(t) values are between −8.3 and −3.0, corresponding to Hf depleted mantle model ages from 2 649 to 2 991 Ma with an average of 2 881 Ma. These data indicate that this granitic pegmatite dyke may have been derived from partial melting of Meso-Neoarchean metamorphic rocks from the Xiaoqinling basement. Granitic pegmatite magma may have emplaced within the Taihua Group wall rocks during the last stage of the middle to high grade metamorphism. Furthermore, according to the petrographic observation, the 1.81 Ga pegmatite dyke and the 1 800–1 750 Ma Xiong’er Group rocks were not undergone middle to high grade metamorphism, indicating 1.81 Ga as the termination of the latest regional metamorphism in the southern margin of the NCC.

Chlorin derivatives are promising photosensitive agents for photodynamic therapy (PDT) of tumors. The aim of the current study is to investigate the PDT therapeutic effects of a novel chlorin-based photosensitizer, meso-tetra[3-(N,N-diethyl)aminomethyl-4-methoxy]phenyl chlorin (TMPC) for gliomas in vitro and in vivo. Physicochemical characteristics of TMPC were recorded by ultraviolet visible spectrophotometer and fluorescence spectrometer. The rate of singlet oxygen generation of TMPC upon photo-excitation was detected by using 1,3-diphenylisobenzofuran (DPBF). The accumulation of TMPC in gliomas U87 MG cells was measured by fluorescence spectrometer. The efficiency of TMPC-PDT in vitro was analyzed by MTT assay and clonogenic assay. The biodistribution and clearance of TMPC were determined by fluorescence measuring. Human gliomas U87 MG tumor-bearing mice model was used to evaluate the antitumor effects of TMPC-PDT. TMPC shows a singlet oxygen generation rate of 0.05 and displays a characteristic long wavelength absorption peak at 653 nm (ε = 15,400). The accumulation of TMPC increased with the increase of incubation time. In vitro, PDT using TMPC and laser showed laser dose- and concentration-dependent cytotoxicity to U87 MG cells. In U87 MG tumor-bearing mice, TMPC-PDT significantly reduced the growth of the tumors. Both in vitro and in vivo, TMPC showed little dark toxicity. In vitro and in vivo studies, it found that TMPC has excellent antitumor activities. It suggests that TMPC is a potential photosensitizer of photodynamic therapy for cancer.

Apatite is a ubiquitous accessory mineral in a variety of rocks and hydrothermal ores. Strontium isotopes of apatite are well known to retain petrogenetic information and have been widely used to investigate the origin of igneous rocks, but such attempts have rarely been made to constrain ore-forming processes of hydrothermal systems. We here report in situ LA-MC-ICPMS Sr isotope data of apatite from the ~1660-Ma Yinachang Fe-Cu-REE deposit, Southwest China. The formation of this deposit was coeval to the emplacement of regionally distributed doleritic intrusions within a continental-rift setting. The deposit has a paragenetic sequence consisting of sodic alteration (stage I), magnetite mineralization (stage II), Cu sulfide and REE mineralization (stage III), and final barren calcite veining (stage IV). The stage II and III assemblages contain abundant apatite, allowing to investigate the temporal evolution of the Sr isotopic composition of the ore fluids. Apatite of stage II (Apt II) is associated with fluorite, magnetite, and siderite, whereas apatite from stage III (Apt III) occurs intimately intergrown with ankerite and Cu sulfides. Apt II has 87Sr/86Sr ratios varying from 0.70377 to 0.71074, broadly compatible with the coeval doleritic intrusions (0.70592 to 0.70692), indicating that ore-forming fluids responsible for stage II magnetite mineralization were largely equilibrated with mantle-derived mafic rocks. In contrast, Apt III has distinctly higher 87Sr/86Sr ratios from 0.71021 to 0.72114, which are interpreted to reflect external radiogenic Sr, likely derived from the Paleoproterozoic strata. Some Apt III crystals have undergone extensive metasomatism indicated by abundant monazite inclusions. The metasomatized apatite has much higher 87Sr/86Sr ratios up to 0.73721, which is consistent with bulk-rock Rb-Sr isotope analyses of Cu ores with 87Sr/86Sri from 0.71906 to 0.74632. The elevated 87Sr/86Sr values of metasomatized apatite and bulk Cu ores indicate that later fluids were dominated by highly radiogenic Sr equilibrated with the Paleoproterozoic country rocks. Results of this study highlight the utilization of in situ Sr isotope analysis of apatite in unraveling the evolution of hydrothermal systems.

Andradite-rich garnet is a common U-bearing mineral in a variety of alkalic igneous rocks and skarn deposits, but has been largely neglected as a U–Pb chronometer. In situ laser ablation-inductively coupled plasma mass spectrometry U–Pb dates of andradite-rich garnet from a syenite pluton and two iron skarn deposits in the North China craton demonstrate the suitability and reliability of the mineral in accurately dating magmatic and hydrothermal processes. Two hydrothermal garnets from the iron skarn deposits have homogenous cores and zoned rims (Ad86Gr11 to Ad98Gr1) with 22–118 ppm U, whereas one magmatic garnet from the syenite is texturally and compositionally homogenous (Ad70Gr22 to Ad77Gr14) and has 0.1–20 ppm U. All three garnets have flat time-resolved signals obtained from depth profile analyses for U, indicating structurally bound U. Uranium is correlated with REE in both magmatic and hydrothermal garnets, indicating that the incorporation of U into the garnet is largely controlled by substitution mechanisms. Two hydrothermal garnets yielded U–Pb dates of 129 ± 2 (2σ; MSWD = 0.7) and 130 ± 1 Ma (2σ; MSWD = 0.5), indistinguishable from zircon U–Pb dates of 131 ± 1 and 129 ± 1 Ma for their respective ore-related intrusions. The magmatic garnet has a U–Pb age of 389 ± 3 Ma (2σ; MSWD = 0.6), consistent with a U–Pb zircon date of 388 ± 2 Ma for the syenite. The consistency between the garnet and zircon U–Pb dates confirms the reliability and accuracy of garnet U–Pb dating. Given the occurrence of andradite-rich garnet in alkaline and ultramafic magmatic rocks and hydrothermal ore deposits, our results highlight the potential utilization of garnet as a powerful U–Pb geochronometer for dating magmatism and skarn-related mineralization.

Muscle cell differentiation is a complex process that is principally governed by related myogenic regulatory factors (MRFs). DNA methylation is considered to play an important role on the expression of MRF genes and on muscle cell differentiation. However, the roles of enzymes specifically in myogenesis are not fully understood. Here, we demonstrate that Tet2, a ten-eleven translocation (Tet) methylcytosine dioxygenase, exerts a role during skeletal myoblast differentiation. By using an immunostaining method, we found that the levels of 5-hydroxymethylcytosine (5-hmC) were much higher in differentiated myotubes than in undifferentiated C2C12 myoblasts. Both Tet1 and Tet2 expression were upregulated after differentiation induction of C2C12 myoblasts. Knockdown of Tet2, but not Tet1, significantly reduced the expression of myogenin as well as Myf6 and myomaker, and impaired myoblast differentiation. DNA demethylation of myogenin and myomaker promoters was negatively influenced by Tet2 knockdown as detected by bisulfite sequencing analysis. Furthermore, although vitamin C could promote genomic 5hmC generation, myogenic gene expression and myoblast differentiation, its effect was significantly attenuated by Tet2 knockdown. Taken together, these results indicate that Tet2 is involved in myoblast differentiation through promoting DNA demethylation and myogenic gene expression.

The Zhoukoudian pluton in the North China craton is a circular granodiorite intrusion containing porphyritic diorite dykes (PDDs), porphyritic granodiorite dykes (PGDs) and abundant mafic microgranular enclaves (MMEs), which provide an excellent opportunity to study fractional crystallization and magma mixing. The PDDs and PGDs are located in the western part of the pluton with the PDDs intruded by the PGDs. The dykes have similar mineral assemblages although plagioclase in the PDDs has higher anorthite content than the PGDs. Linear relationships between the SiO2 and most major and trace element contents, as well as a positive trend of initial 87Sr/86Sr ratios and a negative trend of epsilon Nd values with increasing SiO2 contents for the dykes suggest that both types were formed by assimilation and fractional crystallization of a common parental magma. Major oxide mass balance and trace element Rayleigh fractionation modeling points to early separation of garnet (11 %), clinopyroxene (27 %), orthopyroxene (16 %), plagioclase (25 %), biotite (19 %), and apatite (2 %) and late fractionation of hornblende (25 %), plagioclase (46 %), biotite (25 %), apatite (1 %), and magnetite (3 %). Most MMEs occur within the transitional granodiorite of the Zhoukoudian pluton. Zoned MMEs, dyke-like MME swarms, local presence of concave margins, veins and enclaves of host granodiorite within some MMEs, and several MMEs surrounded by the biotite-rich granodiorite support their formation by multiple magma mixing events, which finally resulted in different whole-rock major oxides and compatible elements, but homogeneous mineral major oxides (except zoned plagioclase), whole-rock incompatible elements and Sr-Nd isotopes between the MMEs and their host granodiorite. We suggest that multiple magma mixing events might also cause complexly zoned plagioclase in the Zhoukoudian pluton. Relative calcic, irregular or patchy cores and dusty zoned mantles from the zoned plagioclase crystals and their relatively low anorthite content indicate multiple mixing events between mafic/intermediate and felsic magmas. The mafic/intermediate end-members could be represented by the diabase dykes and the PDDs. Therefore, the dykes and MMEs in the Zhoukoudian pluton are genetically linked.

Supergene Mn-oxide deposits are commonly related to thick weathering profiles and form as a result of intense and prolonged weathering of Mn-bearing precursor rocks, processes facilitated by a combination of multiple factors including warm and wet climate, relatively quiescent tectonic environment, and favorable geomorphic setting. Precise age constraints of supergene Mn-oxides may provide valuable information on the climatic, tectonic, and geomorphic conditions prevailing in the geological past. 40Ar/39Ar laser incremental heating analysis of cryptomelane from the Baye manganese deposit, western Yunnan-Guizhou Plateau, SW China, was conducted to provide numerical constraints on the ages of supergene Mn enrichment and growth rates of Mn-oxide veins. In this study, two Mn-oxide veins of 3–6 cm thickness, termed as Vein A and B, respectively, were collected for 40Ar/39Ar dating. Vein A is subhorizontal and present in fractures parallel to schistosity of the Proterozoic spessartine schists, whereas Vein B is filled in nearly vertical fractures penetrating the schistosity. A combination of optical microscopy, XRD, SEM, and EMP analyses demonstrate that mineral grains extracted from both veins consist of pure, well-crystallized cryptomlane, which has acicular crystal forms and contains 0.96%–4.70% K2O. Fourteen cryptomelane subsamples extracted from different growth bands of Vein A yield well-defined plateau ages ranging from 1.35 ± 0.05 to 1.16 ± 0.04 Ma (2σ), whereas seven subsamples obtained from Vein B have plateau ages ranging from 1.23 ± 0.05 to 1.01 ± 0.04 Ma (2σ). The age results permit estimation for the growth rates of both veins at ca. 115–153 and 34–67 mm Ma−1, respectively. Distinct growth rates between Veins A and B are likely reflective of different fluid pressures during their formation governed by the orientation of the fractures hosting the veins. The growth rates calculated for both veins are 1–2 orders of magnitude higher than the values (

We combine a simple model potential with closed-orbit theory to study the photodetachment of H � near a dielectric-covered metal surface. We calculate photodetachment cross sections to show that the chem- isorption of a dielectric thin layer on the metal surface can significantly affect the photodetachment of negative ions. Compared to the photodetachment of hydrogen negative ions near clean metallic surfaces, our calculated cross sections show stronger oscillations, the amplitude of the oscillation growing with the layer thickness. For fixed thickness, the amplitude depends on the dielectric constant and on the metallic surface. We expect our study to guide future experimental studies of negative- ion photodetachment from dielectric-covered metallic surfaces.

The safety and feasibility of laparoscopic splenectomy and esophagogastric devascularization are still uncertain. The aim of this study was to compare our results for laparoscopic splenectomy and esophagogastric devascularization with those for open splenectomy and esophagogastric devascularization. From January 2008 to December 2011, 153 patients were diagnosed with portal hypertension and serious gastroesophageal varices in our institute, among which, 107 patients also had repeated upper gastrointestinal bleeding and 85 had severe hypersplenism. Eighty patients chose laparoscopic splenectomy and esophagogastric devascularization and 73 patients underwent the open procedure. Results and outcomes were compared retrospectively. Nine patients underwent conversion to laparotomy in the laparoscopic group. We compared the laparoscopic group (80 patients) and the open group (73 patients). Operating times and the frequencies of blood transfusions were similar. Blood loss was less (P = 0.044), the passing of flatus was earlier (P = 0.041), and hospital stays were shorter (P = 0.028) in the laparoscopic group. Portal vein system thrombosis after laparoscopy was more frequent (P = 0.012) but the rates of main trunk occlusion were similar between the two groups. Pleural effusion after laparoscopy was less (P = 0.021) and, apart from this, there was no difference in other morbidities between the two groups. During a postoperative follow-up period of 2 to 50 months in 80 patients of the laparoscopic group vs. 73 patients of the open group, the incidence of esophagogastric variceal rebleeding, encephalopathy, and secondary liver cancer showed no significant differences. And the mortality rates for each of the groups were not different. The short-term effects of laparoscopic splenectomy and esophagogastric devascularization were better than those for open surgery, and the medium-term effects were similar between these two surgical approaches. Prospective randomized studies with a greater number of cases are needed to confirm the role of laparoscopy in splenectomy and esophagogastric devascularization.

The Qianhe gold deposit in the Xiong’ershan area is located along the southern margin of the Archean-Paleoproterozoic North China Craton. The deposit consists of six orebodies that are hosted in Paleoproterozoic andesites to basaltic andesites and structurally controlled by roughly EW-trending faults. Individual orebodies comprise auriferous quartz veins and disseminated Au-bearing pyrite within hydrothermally altered rocks on both sides of, or close to, the veins. Ore-related hydrothermal alteration has produced various mixtures of K-feldspar, quartz, sericite, chlorite, epidote, carbonate, and sulfides. Pyrite is the most important ore mineral, associated with minor amounts of galena, sphalerite, and chalcopyrite. Other trace minerals include molybdenite, arsenopyrite, scheelite, rutile, xenotime, and parisite. Gold occurs mostly as native gold and electrum enclosed in pyrite or along microfractures of sulfides and quartz. Microthermometric measurements of primary inclusions in auriferous quartz suggest that gold and associated minerals were precipitated in the range of 160–305 °C from aqueous or carbonic-aqueous fluids with salinities of 6–22 wt% NaCl equiv. Samples of molybdenite coexisting with Au-bearing pyrite have Re–Os model ages of 134–135 Ma, whereas ore-related hydrothermal sericite separates yield 40Ar/39Ar plateau ages between 127 and 124 Ma. The Re–Os and 40Ar/39Ar ages are remarkably consistent with zircon U–Pb ages (134.5 ± 1.5 and 127.2 ± 1.4 Ma; 1σ) of the biotite monzogranite from the Heyu-intrusive complex and granitic dikes in and close to the Qianhe gold mine, indicating a close temporal and thus possibly genetic relationship between gold mineralization and granitic magmatism in the area. Fluid inclusion waters extracted from auriferous quartz have δD values of −80 to −72 ‰, whereas the calculated δ 18OH2O values range from 3.1 to 3.8 ‰. The hydrogen and oxygen isotopes from this study and previous work indicate that ore fluids were likely derived from degassing of magmas, with addition of minor amounts of meteoric water. Gold mineralization at Qianhe is temporarily coincident with pervasive bimodal magmatism, widespread fault-basin formation, and well development of metamorphic core complexes in the whole eastern North China Craton that have been interpreted as reflecting reactivation of the craton in the late Mesozoic after prolonged stabilization since its formation in the late Paleoproterozoic. It is therefore concluded that the Qianhe gold deposit formed as a result of this craton reactivation event.

The Haopinggou deposit in the Xiong’ershan district, southern margin of the North China Craton, comprises numerous Au and Ag–Pb–Zn veins hosted in metamorphic rocks of the Late Archean to early Paleoproterozoic Taihua Group. Two stages of mineralization have been recognized: Stage 1 pyrite–quartz veins and Stage 2 Pb–Zn-sulfide veins. Some pyrite–quartz veins are surrounded or cut by Pb–Zn-sulfide veins, others occur as independent veins. Six generations of pyrite have been identified at Haopinggou: Py1 to Py3 in Stage 1 and Py4 to Py6 in Stage 2. Pyrites from Stage 1 are enriched in Au, As, Co, Ni, and Bi, whereas Stage 2 pyrites contain higher Ag, Pb, Zn, Sn, and Sb. Invisible Au mostly occurs as lattice-bound gold in Py2 (up to 92 ppm Au) and Py3 (up to 127 ppm Au) and has a close relationship with As. Native Au grains are also present in Py3 and likely resulted from mobilization and reprecipitation of the invisible Au previously locked in the precursor pyrite. This view is supported by extensive plastic deformation in Stage 1 pyrite as revealed by electron backscatter diffraction analysis. In Stage 2, Ag is mostly present as lattice-bound silver closely associated with Sb in galena (up to 798 ppm Ag). A variety of silver minerals are also present as inclusions within galena or as interstitial grains. These silver minerals were likely formed via Ag–Cu exchange reaction between tetrahedrite and galena or represent exsolution from galena due to a temperature decrease. Pb isotopic compositions differ remarkably between Stage 1 and Stage 2 sulfides, indicating different sources of lead. Pb in Stage 2 Pb–Zn-sulfide veins is consistent with the Haopinggou porphyry close to the veins. The field, textural, compositional, and lead isotopic data led us to conclude that the early gold-bearing pyrite–quartz veins and late silver-bearing Pb–Zn-sulfide veins likely formed from distinct fluid systems related to discrete mineralization events. Our study suggests that Au and Ag–Pb–Zn veins hosted in the same metamorphic terrains may not be genetically related to each other.

The Jigongshan and Qijianfeng batholiths in the Tongbai orogen consist mainly of porphyritic hornblende-biotite monzogranite, biotite monzogranite, and biotite syenogranite, which are variably intruded by lamprophyre, diorite, and syenogranite dykes. Mafic microgranular enclaves commonly occur in the hornblende-biotite monzogranite, whereas surmicaceous enclaves are found in the biotite monzogranite. Both batholiths have zircon U–Pb ages ranging from ca. 139 to 120 Ma, indicating their emplacement in the Early Cretaceous. The hornblende-biotite monzogranite has an adakitic affinity marked by relatively high Sr/Y and (La/Yb)N ratios, lack of Eu anomalies, low MgO and Ni contents, and Na2O > K2O. Its chemical compositions, combined with enriched Sr–Nd isotopic signatures, suggest formation by dehydration melting of mafic rocks in a thickened lower crust. This thickened crust resulted from the Permo-Triassic subduction-collision between the North China and South China blocks and persisted until the Early Cretaceous. The biotite monzogranite and biotite syenogranite have low Al2O3, CaO, and Sr contents, low Rb/Sr, FeOt/MgO, and (Na2O + K2O)/CaO ratios, and flat HREE patterns with moderate to weak Eu anomalies. They were produced by partial melting of crustal materials under relatively low pressure. Partial melting at different crustal levels could have significantly contributed to mechanical weakening of the crust. The diorite and lamprophyre dykes show linear trends between SiO2 and major or trace elements on Harker diagrams, with two lamprophyre samples containing normative nepheline and olivine. These rocks have high La/Yb and Dy/Yb ratios, both displaying co-variation with contents of Yb. They were originated from relatively deep lithospheric mantle followed by fractionation of olivine + clinopyroxene + apatite + Fe–Ti oxides. Extensive partial melting in the lithospheric mantle indicates relatively high temperatures at this level. We suggest that the presence of adakitic magmas, thickened but weakened crust and high temperatures in the lithosphere mantle point to lower crustal delamination in the Early Cretaceous in the Tongbai orogen.

Supergene jarosite-group minerals are widespread in weathering profiles overlying Pb-Zn sulfide ores at Xitieshan, northern Tibetan Plateau, China. They consist predominantly of K-deficient natrojarosite, with lesser amounts of K-rich natrojarosite and plumbojarosite. Electron microprobe (EMP) analyses, scanning electron microcopy (SEM) investigation, and X-ray mapping reveal that the jarosite-group minerals are characterized by spectacular oscillatory zoning composed of alternating growth bands of K-deficient and K-bearing natrojarosite (K2O >1 wt.%). Plumbojarosite, whenever present, occurs as an overgrowth in the outermost bands, and its composition can be best represented by K0.29Na0.19Pb0.31Fe2.66Al0.22(SO4)1.65(PO4)0.31(AsO4)0.04(OH)7.37. The substitution of monovalent for divalent cations at the A site of plumbojarosite is charge balanced by the substitution of five-valent for six-valent anions in XO4 at the X site. Thermogravimetric analysis (TGA) of representative samples reveal mass losses of 11.46 wt.% at 446.6 °C and 21.42 wt.% at 683.4 °C due to dehydroxylation and desulfidation, respectively. TGA data also indicate that the natrojarosite structure collapses at 446.6 °C, resulting in the formation of NaFe(SO4)2 and minor hematite. The decomposition products of NaFe(SO4)2 are hematite and Na2SO4. Powder X-ray diffraction (XRD) analyses show that the jarosite-group minerals have mean unit-cell parameters of a = 7.315 A and c = 016.598 A. XRD and EMP data support the view that substitutions of Na for K in the A site and full Fe occupancy in the B site can considerably decrease the unit-cell parameter c, but only slightly increase a. The results from this study suggest that the observed oscillatory zoning of jarosite-group minerals at Xitieshan resulted mainly from substitutions of K for Na at the A site and P for S at the X site.

The Mesozoic Yangzhaiyu lode gold deposit is situated in the southern edge of the North China craton. Gold mineralization is hosted in Archean amphibolite facies metamorphic rocks, and consists mainly of auriferous quartz veins. Pyrite is the predominant sulfide mineral, with minor amounts of chalcopyrite, sphalerite, and galena. Based on morphology and paragenesis, there are three generations of pyrite, termed as first generation (G1), second generation (G2), and third generation (G3). They have distinct contents, occurrences, and distribution patterns of gold. The coarse-grained, euhedral G1 pyrite contains negligible to low levels of gold, whereas both invisible and visible gold are present in the fine- to medium-grained G2 pyrite that is characterized by abundance of microfractures and porosities, forming a foam-like texture. Laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) depth profiles indicate that invisible gold occurs either as solid solution or as nanoparticles of gold-bearing tellurides in the G2 pyrite. Visible gold is widespread and present as irregular grains and stringers of native gold mostly along grain boundaries or filling microfractures of pyrite, likely resulting from remobilization of invisible gold once locked in the G2 pyrite. The G3 pyrite, invariably intergrown with chalcopyrite, sphalerite, and galena, contains the highest levels of invisible gold. There is a positive correlation between Au, Ag, and Te, indicating that gold occurs as submicroscopic Au-bearing telluride inclusions in the host minerals. Whenever gold, either invisible or visible, is present, As is always below or only marginally higher than the detection limit of LA-ICP-MS. This indicates that As played an insignificant role in gold mineralization. Tellurides are widespread in the auriferous quartz veins, consisting mainly of petzite, calaverite, hessite, altaite, and tellurobismuthite. Native gold commonly occurs as intergrowths with tellurides. Textural evidence indicates a precipitation sequence, in a temporal order, of calcaverite, petzite, altaite, tellurobismuthite, and hessite. Little amount of sulfide phases has been found in association with the tellurides, indicating that tellurides were deposited under low S fugacity (fS2) and/or high Te fugacity (fTe2) conditions. The textural relationships, when combined with fluid inclusion microthermometric data of auriferous quartz veins and tellurides thermodynamic data, permit estimation for logfTe2 during telluride formation, which are −6.8 to −10.8 at 300°C and −9.6 to −17.6 at 250°C. Available geochronological and geochemical data suggest that Te was most likely derived from the late Mesozoic magmatic rocks widespread in the Xiaoqinling district and other parts of the southern North China craton, which were emplaced broadly contemporaneous with gold mineralization at Yangzhaiyu. This study highlights the role of Te and tellurides as important gold scavengers in As-deficient ore fluids.

Icariin, a plant-derived flavonol glycoside, has been proved as an osteoinductive agent for bone tissue engineering. A new bone repair scaffold was generated by thorough mixing of icariin and chitosan/hydroxyapatite (icariin-CS/HA) using freeze-drying technigue. Characteristics of morphology, mechanical properties, biocompatibility, drug release behavior and bone repair abilities in vivo were evaluated. The results show that drug loading process of icariin did not affect physical structure of CS/HA composite significantly but decreased mechanical properies of CS/HA composite, which happened with a high dosage; icariin-CS/HA had favorable cell compatibility and promoted osteogenic differentiation of hBMSCs; the controlled release of icariin was satisfactory and the release retained after 90 d in vitro. In addition, icariin-CS/HA scaffolds had favorable osteoconduction and osteoinduction in vivo, and could fill bone defect sites and stimulate newborn bone tissues formation at early stage. On the basis of these data, icariin-CS/HA is believed to be an optical bone repair scaffold for tissue engineering.

In the IP multimedia subsystem (IMS) of UMTS, two authentication procedures are necessary for IMS subscribers before accessing IMS services: (i) packet-switch domain authentication using the authentication and key agreement of the 3rd Generation Partnership Projects (3GPP AKA), and (ii) IMS authentication using IMS AKA. However, since IMS AKA is based on 3GPP AKA, almost all of the operations are the same. Besides, IMS AKA needs two round-trips to carry out. Therefore, it is inefficient that almost all involved steps in IMS AKA are duplicated. Therefore, we propose a one-pass IMS AKA instead of IMS AKA. The one-pass IMS AKA can keep the security properties of IMS AKA, such as mutual authentication and key agreement. Furthermore, the one-pass IMS AKA not only has at least 45% improvement over IMS AKA in terms of authentication signaling, but also has 76.5% improvement over IMS AKA in terms of storage space.

Late Mesozoic dioritic and quartz dioritic plutons are widespread in the Daye region, eastern Yangtze craton, eastern China. Detailed geochronological, geochemical, and Sr–Nd isotopic studies have been undertaken for most of these plutons, in an attempt to provide a comprehensive understanding in the age, genesis and geodynamical control of the extensive magmatism. SHRIMP and LA-ICP-MS zircon U–Pb dating indicate that the plutons were emplaced in the range of latest Jurassic (ca. 152 Ma) to early Cretaceous (ca. 132 Ma), which was followed by dyke emplacement between 127 and 121 Ma and volcanism during the 130–113 Ma interval. Both diorites and quartz diorites are sodic, metaluminous, high-K calc-alkaline, and characterized by strongly fractionated, sub-parallel REE patterns without obvious Eu anomalies. The rocks are enriched in highly incompatible elements and large ion lithophile elements, but depleted in high field strength elements. Samples of diorite and quartz diorite have similar Sr–Nd isotopic compositions that are consistent with the early Cretaceous basalts and mafic intrusions throughout the eastern Yangtze craton. The geochemical and isotopic data, together with results of geochemical modeling, indicate an enriched mantle source for the plutonic rocks. The quartz diorites have geochemical signatures resembling adakites, such as high Al2O3 (15–19 wt.%), Sr (630–2,080 ppm), Na2O (>3.5 wt.%), negative Nb–Ta anomalies, low Y (7–19 ppm), Yb (0.5–1.8 ppm), Sc (5–15 ppm), and resultant high Sr/Y (45–200) and La/Yb (31–63) ratios. Genesis of the adakitic quartz diorites is best explained in terms of low-pressure intracrustal fractional crystallization of cumulates consisting of hornblende, plagioclase, K-feldspar, magnetite, and apatite from mantle-derived dioritic magmas. Mantle-derived magmatism broadly coeval with that of the Daye region also is widespread in other regions of the eastern Yangtze craton, reflecting large-scale melting of the lithospheric mantle during the Late Mesozoic. The large-scale magmatism was most likely driven by lithospheric extension associated with thinning of lithospheric mantle beneath the eastern China continent.

The Tongshankou Cu–Mo deposit, located in the westernmost Daye district of the Late Mesozoic Metallogenic Belt along the Middle-Lower reaches of the Yangtze River, eastern China, consists mainly of porphyry and skarn ores hosted in the Tongshankou granodiorite and along the contact with the Lower Triassic marine carbonates, respectively. Sensitive high-resolution ion microprobe zircon U–Pb dating constrains the crystallization of the granodiorite at 140.6 ± 2.4 Ma (1σ). Six molybdenite samples from the porphyry ores yield Re–Os isochron age of 143.8 ± 2.6 Ma (2σ), while a phlogopite sample from the skarn ores yields an 40Ar/39Ar plateau age of 143.0 ± 0.3 Ma and an isochron age of 143.8 ± 0.8 Ma (2σ), indicating an earliest Cretaceous mineralization event. The Tongshankou granodiorite has geochemical features resembling slab-derived adakites, such as high Sr (740–1,300 ppm) and enrichment in light rare earth elements (REE), low Sc (

Supergene Mn-oxide deposits are widely distributed in Guangxi, Guangdong, Yunnan, and Hunan Provinces, South China, accounting for 18% of the total Mn reserves in the country. Direct dating of supergene Mn enrichment, however, is lacking. In this paper, we present high-resolution 40Ar/39Ar ages of Mn oxides from the Xinrong Mn deposit, western Guangdong, to place numerical constraints on the timing and duration of supergene Mn enrichment. A total of ten cryptomelane samples, spanning a vertical extent of 67 m, were dated using the 40Ar/39Ar laser incremental heating technique, with seven samples yielding well-defined plateau or pseudo-plateau ages ranging from 23.48 ± 0.91 to 2.06 ± 0.05 Ma (2σ). One sample yields a staircase spectrum that does not reach a plateau; the spectrum, however, indicates the presence of two or more generations of Mn oxides in the sample, whose ages are best estimated at 22.34 ± 0.31 and 10.2 ± 0.86 Ma, respectively. The remaining two samples gave meaningless or uninterpretable results due to significant 39Ar recoil and contamination by old phases. The 40Ar/39Ar data thus reveal a protracted history of weathering and supergene Mn enrichment that started at least in the end of the Oligocene or beginning of Miocene and extending into the latest Pliocene. Staircase-apparent age spectra, resulting from banded or botryoidal samples, yield an average growth rate of Mn oxides at 0.6–0.7 × 10−3 mm kyr−1. The values indicate that a 1-mm grain of Mn oxides may host minerals precipitated during a time span of ca. 1.5 m.y., and accumulation of Mn oxides to form economic deposits under weathering environments may take millions of years. The distribution of weathering ages shows that the oldest Mn oxides occur on the top of the profile, whereas the youngest minerals are found at the bottom, suggesting downward propagation of weathering fronts. However, two samples located at the intermediate depths of the profile yield ages comparable with those occurring at the highest elevations. Such a complexity of age distribution is interpreted in terms of preferential penetration of Mn-rich weathering solutions along more permeable fault zones, or as a result of multi stages of dissolution and re-precipitation of Mn oxides. A synthesis of geochronological and geological data suggests that formation of the Xinrong deposit was a consequence of a combination of favorable lithological, climatic, and structural conditions. Because the climatic and structural conditions are similar among the provinces of South China during the Cenozoic, the geochronological results obtained at Xinrong may also have implications for the timing of supergene Mn enrichment throughout South China.

The early Tertiary Sanerlin uranium deposit is located near the southwestern margin of the Chaling–Yongxing pull-apart basin defined by the Chaling–Yongxing and Chenxian–Linwu sinistral strike-slip faults in southern China. The uranium ores are hosted in 15 breccia-vein bodies, which are separately located in the cores of three secondary anticlines of the Upper Permian Dangchong Formation. Individual breccia-vein bodies are composed of fragments of silicified shale and sandstone from the Dangchong Formation, and quartz veinlets as cements. These fragments, together with quartz veins, form a mosaic texture. Hydrothermal pitchblende is the only commercial uranium mineral, mainly occurring as disseminated grains within quartz veins or coating fragments. Other metallic minerals include molybdenite, pyrite, chalcopyrite, galena, sphalerite, and red microcrystalline hematite. Fluid inclusions in quartz veins have homogenization temperatures ranging from 150 to 280 °C, and calculated salinity values between 5.6 and 13.4 wt% NaCl equivalent. Stable isotope analyses show that the mineralizing fluid was characterized by δ18O values of –2.2 to +2.6‰ and δDH2O values of –134 to –110‰. These analytical data demonstrate that hydrothermal fluids were mainly derived from formation waters (brines) of the Chaling–Yongxing basin. Fluid overpressuring was caused by an abnormal geothermal gradient and impermeable shales in the deposit area. The geometry, texture, and structure of the breccia-vein system, along with the fluid pressure estimates, suggest that hydraulic fracturing generated the mineralized breccia-vein system. Pitchblende and associated minerals were deposited when gaseous phases were released abruptly from the ore fluids due to the hydraulic fracturing.

The Jingtieshan deposit occurs in a Precambrian tectonic-stratigraphic terrane within the Northern Qilian Caledonian Orogen, and is generally considered as a Superior-type iron formation. The deposit is characterized by Fe-Si-Ba and Cu mineralization and consists of two types of orebodies, an upper jasper-barite-iron deposit and a lower copper sulfide deposit. The iron orebodies occur as independent stratigraphic layers concordant within a thick argillaceous succession, and exhibit fine-grained textures and well-developed sedimentary layering. The ores are predominantly composed of specularite and jasper with lesser amounts of magnetite, hematite, siderite, and barite. The presence of barite, hematite and jasper as major components shows that the iron ores were precipitated in a relatively oxidized ocean floor environment. The Cu orebody directly underlies the iron ore and is hosted by chlorite-sericite-quartz phyllite. The Cu mineralization is composed of pyrite and chalcopyrite and is characterized by stockwork. The disseminated and stockwork Cu mineralization is metamorphosed and concordant with respect to foliation, indicating pre-fabric development, i.e. pre-metamorphism, and was probably originally formed by reduced fluids reacting at the base of and within the oxide iron formation. Geochemical data show that the jasper-barite-iron ores, which resemble Superior-type iron formations, have a high input of hydrothermal-hydrogeneous elements (SiO2, av.=56%; Fe2O3t, av.=30%; Mn, av.=0.45%; BaO, av.=16.7%) with minimal terrigeneous input (