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The reasonable design of metal-organic framework (MOF)-derived nanomaterial has important meaning in increasing the enrichment efficiency in the study of protein phosphorylation. In this work, a polyoxometalate (POM) functionalized magnetic MOF nanomaterial (Fe 3 O 4 @MIL-125-POM) was designed and fabricated. The nanomaterial with multi-affinity sites (unsaturated metal sites and metal oxide clusters) was used for the enrichment of phosphopeptides. Fe 3 O 4 @MIL-125-POM had high-efficient enrichment performance towards phosphopeptides (selectivity, a mass ratio of bovine serum albumin/α-casein/β-casein at 5000:1:1; sensitivity, 0.1 fmol; satisfactory repeatability, ten times). Furthermore, Fe 3 O 4 @MIL-125-POM was employed to enrich phosphopeptides from non-fat milk digests, saliva, serum, and A549 cell lysate. The enrichment results illustrated the great potential of Fe 3 O 4 @MIL-125-POM for efficient identification of low-abundance phosphopeptides., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH, DE part of Springer Nature.)

Hemoglobins, with heme as a cofactor, are functional proteins that have extensive applications in the fields of artificial oxygen carriers and foods. Although Saccharomyces cerevisiae is an ideal host for hemoglobin synthesis, it lacks a suitable transport system to utilize additional heme for active expression of hemoglobins, resulting in the cellular aggregation and degradation of the latter. Here, an effective heme importer, heme-responsive gene 4 (Hrg-4), was selected from six candidates through the comparison of effects on the growth rates of Δhem1 S. cerevisiae strain and the activities of various hemoglobins when supplemented with 5 mg·L -1 exogenous heme. Additionally, to counter the instability of plasmid-based expression and the metabolic burden introduced from overexpressing Hrg-4, a series of hrg-4 integrated strains were constructed and the best engineered strain with five copies of hrg-4 was chosen. We found that this engineered strain was associated with an increased binding rate of heme in monomeric leghemoglobin and multimeric human hemoglobin (76.3% and 16.5%, respectively), as well as an enhanced expression of both hemoglobins (52.8% and 17.0%, respectively). Thus, the engineered strain with improved heme uptake can be used to efficiently synthesize other heme-binding proteins and enzymes in S. cerevisiae., (© 2024 Federation of European Biochemical Societies.)

Speech Emotion Recognition (SER) is the process of recognizing emotions by extracting few features of speech signals. It is becoming very popular in Human Computer Interaction (HCI) applications. The challenge is to extract relevant features of speech to recognize emotions with a low computational cost. In this paper, a lightweight Convolutional Neural Network (LCNN) based model has been proposed which extracts useful features automatically. The speech samples are converted into spectrograms of size 224 × 224 for LCNN input. 5 CNN layers and stride are used for down-sampling the feature maps in place of pooling layers which reduces the computational cost. It has been evaluated for accuracy on publicly available benchmark datasets EMOVO (81%), EMODB (87%), and SAVEE (80%). The accuracy of proposed model is also found to be better than SER CNN-assisted model, ResNet-18 and ResNet-34 models. Very few speech datasets are available in Indian ascent. So, authors have created a new Indian Emotional Speech Corpora (IESC) in English language with 600 speech samples recorded from 8 speakers using 2 sentences in 5 emotions. It will be made publicly available for researchers. The accuracy of the proposed LCNN model on IESC is found to be 95% which is better than existing datasets. [ABSTRACT FROM AUTHOR]

Animal-derived drugs are an indispensable part of folk medicine worldwide. However, their chemical constituents are poorly approached, which leads to the low level of the quality standard system of animal-derived drugs and further causes a chaotic market. Natural peptides are ubiquitous throughout the organism, especially in animal-derived drugs. Thus, in this study, we used multi-source leeches, including Hirudo nipponica (HN), Whitmania pigra (WP), Whitmania acranulata (WA), and Poecilobdella manillensis (PM), as a model. A strategy integrating proteogenomics and novel pseudotargeted peptidomics was developed to characterize the natural peptide phenotype and screen for signature peptides of four leech species. First, natural peptides were sequenced against an in-house annotated protein database of closely related species constructed from RNA-seq data from the Sequence Read Archive (SRA) website, which is an open-sourced public archive resource. Second, a novel pseudotargeted peptidomics integrating peptide ion pair extraction and retention time transfer was established to achieve high coverage and quantitative accuracy of the natural peptides and to screen for signature peptides for species authentication. In all, 2323 natural peptides were identified from four leech species whose databases were poorly annotated. The strategy was shown to significantly improve peptide identification. In addition, 36 of 167 differential peptides screened by pseudotargeted proteomics were identified, and about one-third of them came from the leucine-rich repeat domain (LRR) proteins, which are widely distributed in organisms. Furthermore, six signature peptides were screened with good specificity and stability, and four of them were validated by synthetic standards. Finally, a dynamic multiple reaction monitoring (dMRM) method based on these signature peptides was established and revealed that one-half of the commercial samples and all of the Tongxinluo capsules were derived from WP. All in all, the strategy developed in this study was effective for natural peptide characterization and signature peptide screening, which could also be applied to other animal-derived drugs, especially for modelless species that are less studied in protein database annotation. [ABSTRACT FROM AUTHOR]

The southwestern Yangtze Craton hosts over 400 carbonate-hosted zinc–lead deposits that are mostly subjected to regional folding and thrusting; however, the structural controls are poorly understood, and genesis of the deposits also remains controversial. The Kuangshanchang zinc–lead deposit (Zn + Pb: 4 Mt @ 25%) provides a typical example to unravel the issues. We herein present new structural and geochemical data from field investigation and structural mapping at Kuangshanchang. The deformational history was reconstructed by structural mapping and 158 sets of data, including NW-directed thrust faults (D1–1), NW-striking sinistral and normal faults (D1–2), and N–S-striking dextral faults (D2). Whole-rock geochemical analysis from 20 samples yields high anomalies of the ore-forming elements (Zn, Pb, Ag, Ge, Ga, and Cd) within the D1–2-stage NW-striking faults, highlighting its pivotal ore-controlling role. In situ LA–ICP–MS microanalysis from 12 samples shows that Ti, V, Cr, Mn, Co, Ni, Cu, Zn, Ge, As, Se, Ag, Sb, and Pb is enriched in pyrite. Low Co and Ni abundances (0.01 × 10–6–20.99 × 10–6) and Co/Ni ratios (0.01–2.35) constrain a low-temperature hydrothermal origin for pyrite. New field, structural, and geochemical data, integrated with previous studies, allow for a genetic model coinciding with MVT deposits. We suggest the D1–2-stage NW-striking high-angle extensional faults and the NE-striking interlayer fractures jointly determine the localization of the orebodies at the deposit scale. Our research enhances the understanding on the genesis of the zinc–lead deposits in the southwestern Yangtze Craton and provides guidelines for regional and deposit-scale prospecting. [ABSTRACT FROM AUTHOR]

Background and aims: This study performed a network pharmacology analysis to explore the potential anticancer activity of baicalein against oral squamous cell carcinoma (OSCC). Methods: The differentially expressed genes in OSCC were identified by the OSCC, and the key module related to OSCC was acquired by the weighted gene co‐expression network analysis from GSE30784. Baicalein targets were obtained from GeneCards, SwissTargetPrediction and TCMSP (the traditional Chinese medicine systems pharmacology database and analysis platform) databases. Apart from GSE30784, OSCC‐related genes were acquired from the Comparative Toxicogenomics Database and DisGeNET platform. The baicalein targets and OSCC‐related genes were overlapped to acquire the drug–disease interaction genes. We input the candidate drug–disease interaction genes into the STRING database and created the protein–protein interaction network. The hub genes in the network were identified by cytoHubba. The expression levels of hub genes between cancer tissues and normal tissues were evaluated based on The Cancer Genome Atlas. Moreover, we performed the cancer immune infiltration analysis and evaluated the association between the expression of HIF1A and the abundance of infiltrating immune cells. The molecular docking between HIFA and baicalein was also performed and visualized. Additionally, the enrichment analysis was performed based on Gene Ontology and Kyoto Encyclopedia of Genes and Genomes database. Results: After overlapping the candidate baicalein targets with OSCC‐related genes, 34 candidate drug–disease interaction genes were obtained. cytoHubba identified the top 10 genes with high centrality measures from the network, including AKT1, CD44, EGFR, HIF1A, IGF1, MMP2, MYC, PTGS2, STAT3 and TP53. The enriched biological process terms included regulation of apoptotic signaling pathway, regulation of cysteine‐type endopeptidase activity and cellular response to chemical stress. The top five enriched pathways comprised Kaposi sarcoma‐associated herpesvirus infection, hepatitis C, p53 signaling pathway, Epstein–Barr virus infection and proteoglycans in cancer. The expression of HIF1A was positively associated with the infiltration levels of CD4 + T cells (cor = 0.131, p = 0.004) and dendritic cells (cor = 0.098, p = 0.03), whereas negatively associated with B cells (cor = −0.098, p = 0.03). Conclusion: Our results suggested that baicalein might be a candidate drug against OSCC. More studies are necessary to validate its anticancer effect and explore the underlying mechanisms. [ABSTRACT FROM AUTHOR]

Hydrothermal alteration with bleaching of host rocks is the most important prospecting indicator for gold deposits in the Jiangnan Orogen Belt. The alteration has been identified as pre-ore carbonate (siderite)-sericitization and the Fe of siderite in the alteration zone is derived from the host rocks rather than fluids. In addition, such alteration decreases in intensity and width with depth and gold mineralization also occur in the non-bleached rocks, casting doubt on the reliability of the prospecting indicator. Detailed petrographic work and SEM analysis on the Wangu deposit indicate that there are two types of siderites, i.e., Sd1 and Sd2. Among them, Sd1 grains are relatively small and distributed along the planes of unaltered host rocks, while Sd2 grains, only occurring in the altered slates, are commonly larger. Both types of siderites were altered by auriferous fluids, producing porous cores and minerals such as pyrite, quartz, and ankerite. Compared with unaltered parts, the altered parts have lower Fe, but higher U, Pb, and REE. In addition, Sd1 and Sd2 are similar in Mn, Na, V, and Sr concentrations but different in Fe and Mg. The occurrence and geochemical compositions of both siderites indicate that Sd1 could be transformed into Sd2 by pre-mineralization alteration through dissolution-reprecipitation. Chlorite is another important Fe-bearing mineral in the host rocks, and EPMA analysis suggests that it is ripidolite with relatively high Fe contents. Consequently, chlorite can also provide Fe to form the pre-ore carbonate(siderite)-sericitization. Geochemical modeling demonstrates that both ripidolite and siderite can result in sulfidation and therefore gold precipitation. As a result, this study demonstrates that pre-ore alteration with characterized bleaching is not a prerequisite for gold mineralization despite of its prominent features. Due to the presence of Fe-bearing Sd1 and chlorite, gold mineralization could still occur through sulfidation in the unaltered rocks. [ABSTRACT FROM AUTHOR]

The Dulong deposit, located in the Laojunshan area of southeastern Yunnan, China, is an important polymetallic deposit due to its high reserves of tin, zinc, and indium. The occurrence state of indium is critical for understanding its supernormal enrichment mechanism. Previous studies investigated the occurrence state of indium (including the valence state) based on the indium content in sphalerite and the correlation between metal concentrations. However, more evidence is needed to better constrain indium occurrence at the micro-, nano-, or even atomic scale. In this study, EPMA-FIB-SEM-TEM and XPS techniques were employed to investigate the indium distribution characteristics and occurrence state in sphalerite from the Dulong Sn–Zn–In polymetallic deposit. The maximum concentration of indium in the indium-rich sphalerite samples is 0.37 %, and the results of the EPMA analysis showed a relatively homogeneous distribution of indium in sphalerite. The FIB-SEM-TEM results demonstrated that the lattice stripes of sphalerite were periodically and continuously distributed at the nanoscale, confirming that sphalerite in the deposit was an excellent single crystal structure, and the peak heights of the various characteristic peaks of indium in the EDX spectra were relatively close to each other, with no distinct peaks of high indium content. In addition, the XPS results indicate that the element valence state of indium in sphalerite is In3+, and it combines with S2− to form a bond. These results indicate that indium in sphalerite of the Dulong deposit is uniformly distributed at both the micro- and nanoscale, and there is no indium-independent mineral. In3+ enters the crystal lattice of sphalerite by replacing Zn2+ in the form of isomorphic substitution. [ABSTRACT FROM AUTHOR]

The Jiajika granitic- and pegmatite-type lithium deposit, which is in the Songpan-Garze Orogenic Belt in western Sichuan Province, China, is the largest in Asia. Previous studies have examined the geochemistry and mineralogy of pegmatites and their parental source rocks to determine the genesis of the deposit. However, the evolution of magmatic-hydrothermal fluids has received limited attention. We analyzed He–Ar–H–O isotopes to decipher the ore-fluid nature and identify the contribution of fluids to mineralization in the late stage of crystallization differentiation. In the Jiajika ore field, two-mica granites, pegmatites (including common pegmatites and spodumene pegmatites), metasandstones, and schists are the dominant rock types exposed. Common pegmatites derived from early differentiation of the two-mica granitic magmas before they evolved into spodumene pegmatites during the late stage of the magmatic evolution. Common pegmatites have 3He/4He ratios that vary from 0.18 to 4.68 Ra (mean 1.62 Ra), and their 40Ar/36Ar ratios range from 426.70 to 1408.06 (mean 761.81); spodumene pegmatites have 3He/4He ratios that vary from 0.18 to 2.66 Ra (mean 0.87 Ra) and their 40Ar/36Ar ratios range from 402.13 to 1907.34 (mean 801.65). These data indicate that the hydrothermal fluids were shown a mixture of crust- and mantle-derived materials, and the proportion of crust-derived materials in spodumene pegmatites increases significantly in the late stage of the magmatic evolution. The δ18OH2O–VSMOW values of common pegmatites range from 6.2‰ to 10.9‰, with a mean value of 8.6‰, and δDV–SMOW values vary from − 110‰ to − 72‰, with a mean of − 85‰. The δ18OH2O–VSMOW values of spodumene pegmatites range from 5.3‰ to 13.2‰, with a mean of 9.1‰, and δDV–SMOW values vary from − 115‰ to − 77‰, with a mean of − 91‰. These data suggest that the ore-forming fluids came from primary magmatic water gradually mixing with more meteoric water in the late stage of the magmatic evolution. Based on the He–Ar–H–O and other existing data, we propose that the ore-forming metals are mainly derived from the upper continental crust with a minor contribution from the mantle, and the fluid exsolution and addition of meteoric water during the formation of pegmatite contributed to the formation of the Jiajika superlarge lithium deposit. [ABSTRACT FROM AUTHOR]

Selective catalytic reduction (SCR) has been one of the most efficient and widely used technologies to remove nitrogen oxides (NOx). SCR research has developed rapidly in recent years, which can be reflected by the dramatic increase of related academic publications. Herein, based on the 10,627 documents from 2001 to 2020 in Web of Science, the global research landscape and hotspots in SCR are investigated based on a comprehensive bibliometric analysis. The results show that SCR research has developed positively; the annul number of articles increase sharply from 246 in 2001 to 1092 in 2020. People's Republic of China and Chinese Academy of Sciences are the most productive country and institution, respectively. The global collaboration is extensive and frequent, while People's Republic of China and USA have the most frequent research cooperation. Applied Catalysis B-Environmental is the leading publication source with 711 records. Five major research areas on SCR are identified and elaborated, including catalyst, reductant, deactivation, mechanism, and others. Zeolite is the most widely studied SCR catalyst, while copper, silver, platinum, and iron are the most popular metal elements in catalyst. Ammonia (NH3) is dominated among various SCR reductants, while hydrocarbon reductant has gained more attention. Sulfur dioxide (SO2) and vapor are the two most concerned factors leading to catalyst deactivation, and catalyst regeneration is also an important research topic. Density functional theory (DFT), in situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS), Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), and kinetics are the most widely used methods to conduct mechanism study. The studies on "low temperature," "atomic-scale insight," "elemental mercury," "situ DIRFTS investigation," "arsenic poisoning," "SPOA-34," "Cu-CHA catalyst," "TiO2 catalyst," and "Ce catalyst" have been the hotspots in recent years. [ABSTRACT FROM AUTHOR]

The alternate load path method for progressive collapse analysis ignores the cause and mechanism of member failure and its influence on the dynamic effect of the remaining structures. It must assume the location of member failure, which is unsuitable for grid structures with many members. In this paper, by using the double broken line follow-up strengthening model and the proposed VUMAT material constitutive model, taking the member instability and material failure as the member failure criteria and considering the geometric nonlinearity and material nonlinearity, the instantaneous member removal method for deleting the failure member in real time was proposed. On this basis, nonlinear dynamic analysis for a three-layer space truss was used to compare the effects of different member failure criteria on the structural responses, such as the member failure sequence and the occurrence time of the continuous structural collapse. The results show that when considering the instability of members, the initial member failure and the final progressive collapse occur earlier than when using the material failure criterion, which is more similar to the actual situation. Furthermore, the proposed VUMAT material constitutive model can apply to study the progressive collapse behavior of space truss structures. [ABSTRACT FROM AUTHOR]

Highlights: Self-healing graphene- and MXene-based composites can be deployed in wearable sensors, supercapacitors, anticorrosive coatings, electromagnetic interference shielding, electronic-skin, and soft robotics. Self-healing graphene- and MXene-based composites have shown improved electrical conductivity, mechanical properties, healing efficacy, and energy conversion efficacy. Self-healing structures can open up considerable new horizons in the future of healthcare, sensors, electronics, robotics, supercapacitors/batteries, coatings, and biomedicine. Today, self-healing graphene- and MXene-based composites have attracted researchers due to the increase in durability as well as the cost reduction in long-time applications. Different studies have focused on designing novel self-healing graphene- and MXene-based composites with enhanced sensitivity, stretchability, and flexibility as well as improved electrical conductivity, healing efficacy, mechanical properties, and energy conversion efficacy. These composites with self-healing properties can be employed in the field of wearable sensors, supercapacitors, anticorrosive coatings, electromagnetic interference shielding, electronic-skin, soft robotics, etc. However, it appears that more explorations are still needed to achieve composites with excellent arbitrary shape adaptability, suitable adhesiveness, ideal durability, high stretchability, immediate self-healing responsibility, and outstanding electromagnetic features. Besides, optimizing reaction/synthesis conditions and finding suitable strategies for functionalization/modification are crucial aspects that should be comprehensively investigated. MXenes and graphene exhibited superior electrochemical properties with abundant surface terminations and great surface area, which are important to evolve biomedical and sensing applications. However, flexibility and stretchability are important criteria that need to be improved for their future applications. Herein, the most recent advancements pertaining to the applications and properties of self-healing graphene- and MXene-based composites are deliberated, focusing on crucial challenges and future perspectives. [ABSTRACT FROM AUTHOR]

The Huashandong W deposit (7.7 Mt @ 0.26% WO3) is a newly discovered Neoproterozoic scheelite-dominated deposit in the world-class Jiangnan tungsten belt, South China. It occurs largely in metasedimentary rocks near the western margin of the Neoproterozoic Jiuling batholith and mainly consists of W-bearing exogreisen, hydrothermal breccias, and quartz veins. Two episodes of Neoproterozoic granite magmatism are identified with zircon U-Pb ages of ca. 830–823 and 807–804 Ma, respectively. According to cross-cutting relationships and mineral assemblages, two periods of hydrothermal alteration and W mineralization, corresponding to the two episodes of granite magmatism, are recognized in the Huashandong deposit. The early period is dominated by greisenization and associated scheelite mineralization whereas the late period is characterized by sericitization, hydrothermal brecciation, quartz veining, and associated scheelite and minor wolframite mineralization. Molybdenite Re-Os dating indicates that the early- and late-period W mineralization took place at ca. 828 and 800 Ma, respectively. Zircon trace element characteristics suggest that the Jiuling granite crystallized from reduced granitic magmas and has the potential for W mineralization. The petrologic and geochemical features of the Jiuling granite, coupled with the zircon U-Pb ages and Hf isotopic signatures and molybdenite Re-Os ages, imply that the Huashandong W deposit is genetically related to two phases of evolved granodiorites in the Jiuling batholith. The magmatic-hydrothermal nature of both metallogenic events is confirmed by H-O isotopes on hydrothermal quartz. [ABSTRACT FROM AUTHOR]

Tungsten-tin-(rare-metal) deposits are most commonly granite-related and an important source of critical metals. This study describes the fluid evolution in the Tiantangshan Rb-Sn-W deposit, Nanling Range, China, and discusses the implications for mineralizing processes. Mineralization at Tiantangshan is spatially zoned. The greisen roof hosts wolframite-cassiterite quartz veins. The surrounding volcanic rocks host biotite quartz veins (Rb mineralization) crosscut by cassiterite quartz veins and sphalerite-galena quartz veins. The earliest intermediate-density fluids are responsible for the early W-(Sn)-Rb mineralization and evolve towards decreasing homogenization temperature (Th) and ratios of W, Sn, Rb, Cs, Fe, and Mn to Na + K as the fluid migrated from the greisen to the volcanic rocks hosted veins (Th: 420 to 350 °C; salinity: 13 to 4 wt% NaCleq). The spatial distribution of mineralization and fluid paragenesis indicates that precipitation of wolframite, early cassiterite, and Rb-rich biotite was associated with a pH increase during fluid-rock interaction. Late cassiterite and intergrown quartz precipitated from a degassing fluid with lower Th (mainly 360 to 340 °C) and salinity (10 to 2 wt% NaCleq) and with distinctly lower Sn concentrations. Late cassiterite precipitation is therefore likely related with depressurization by brittle failure of the rock leading to simultaneous boiling and meteoric water input. Late Pb–Zn mineralization precipitated from low Th (< 320 °C) and salinity (0 to 2 wt% NaCleq) fluids through extensive mixing with meteoric water. The tempo-spatial development of Rb-Sn-W-Pb–Zn mineralization at Tiantangshan was controlled by a mixing fluid regime, where input of meteoric water gradually increased with time. [ABSTRACT FROM AUTHOR]

Orogenic gold deposits, though construed to focused fluid flow during orogenesis, commonly post-date the main accretionary events. Several lines of evidence indicate that orogenic gold formation in the Arabian–Nubian Shield continued through the orogen collapse stage and associated rapid exhumation and thermal re-equilibration. The Gidami gold deposit in the Eastern Desert of Egypt is associated with post-foliation, brittle-ductile shear zones that deformed a weakly foliated tonalite-trondhjemite massif dated as ~ 704 Ma (U–Pb zircon age). Gold-sulfide quartz veins exhibit textural features indicative of repeated mylonitization, recrystallization, and muscovite crystallization. New 40Ar/39Ar ages of muscovite flakes from the auriferous quartz veins and from the altered wallrock overlap within analytical uncertainty at ~ 583 Ma, which corresponds to the climax of extension-related wrenching and rapid exhumation in the region (~ 596 to 582 Ma). Laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) data coupled with microtextural characteristics suggest that early formed pyrite generations experienced substantial fluid-mediated recrystallization, and that a set of metals was remobilized by later fluids. A late generation of fibrous pyrite, ubiquitous in microfractures, deposited while the veins re-opened and deformed. The occurrence of free gold particles along with a late-paragenetic assemblage of galena-sphalerite-chalcopyrite(± hessite ± cervelleite) was related to influx of low salinity, metalliferous H2O-NaCl-CO2-CH4 fluids as indicated by the fluid inclusion laser Raman spectroscopy and microthermometry results. Au-mobilization and redeposition at T ≤ 350 °C and P ~ 1 to 1.7 kbar, triggered by intermittent fluid pluses and thermal re-equilibration, were most likely stimulated by extensional structures and within-plate magmatism. Coincident province- and deposit-scale pressure–temperature-time data highlight the pivotal role of the orogenic collapse tectonics in gold endowment in the Central Eastern Desert's crust. [ABSTRACT FROM AUTHOR]

Slurry impregnation and gaseous Si infiltration were effectively used to produce compact MoSi2-doped Si–HfB2–SiC/Si–SiC (HMSS/SS) coatings with a thickness of 250 μm to protect carbon fibre reinforced carbon (Cf/C) composites from oxygen corrosion at 1700°C. The HMSS/SS coating obtained with a mosaic structure makes it possible to protect Cf/C composites at 1700°C for 276 h and the mass reduction is only 0.99%. The pinning effect of the embedded hafnia, the generated MoB together with the Hf, Mo co-doped Si-based glass layer, which successfully prevented the migration of oxygen, was attributed to the superior oxidation protection ability of the HMSS/SS coatings. This work provides a practical method for successfully extending the service life of Cf/C composites in the aerospace industry. [ABSTRACT FROM AUTHOR]

The Kalatongke district is located in northern Xinjiang, where the Kalatongke Cu–Ni sulfide deposit is one of the most famous early Permian Cu–Ni sulfide deposits. At present, 13 shallow mafic intrusions lying less than 500 m in the subsurface have been explored and almost all orebodies are hosted in these mafic intrusions. The ore-bearing intrusions are controlled by faults and are characterized by high magnetic, high density, low resistivity and low seismic wave velocity. With the depletion of proved resources, deep and peripheral prospecting is imminent in the study area. In this paper, three-dimensional (3D) mineral prospectivity modeling is implemented by integrating 3D geological–geophysical data and ore deposit geology. Relevant exploration criteria for prediction were acquired as follows: (1) The bi-dimensional empirical mode decomposition (BEMD) was applied to decompose magnetic and gravity data, and the decomposed images were used to interpret faults and construct fault buffering models; (2) the magnetic susceptibility and density models were obtained by inversion of gravity data and magnetic data; and (3) discrete smooth interpolation was used to interpolate frequency domain controlled-source electromagnetic method (FDCSEM) data and seismic data, and obtain resistivity and seismic wave velocity models. Taking fault buffering model, geophysical models (density, magnetic susceptibility, seismic wave velocity and resistivity) as exploration criteria, the bagging-based positive–unlabeled data learning (BPUL) algorithm that can effectively address the issue of imbalanced training data was used for 3D mineral prospectivity modeling. Random Forest (RF) and XGBoost were applied as the base learners of BPUL to develop novel BPUL–RF and BPUL–XGBoost models, respectively. The results indicate that the BPUL–XGBoost showed better performance than the BPUL–RF, RF and XGBoost prediction models. The prediction–area plot was applied to outline the targets, which are of great significance for further Cu–Ni exploration in the Kalatongke district. [ABSTRACT FROM AUTHOR]

The identification of multivariate geochemical anomalies is critical in mineral exploration. Machine learning algorithms have been successfully employed in the recognition of multivariate geochemical anomalies in support of mineral exploration, owing to their strong ability to learn the complex relationship between geochemical characteristics and mineralization. However, applications of machine learning algorithms suffer from data redundancy and the curse of dimensionality. In this study, a hybrid model combining t-distributed stochastic neighbor embedding (t-SNE) and random forest (RF) was used to solve the aforementioned problems in geochemical mapping for gold exploration in the northwestern Hubei Province of China. Specifically, t-SNE was used for dimension reduction and feature extraction from the major and trace elements of geochemical survey data, and RF was used for probabilistic classification of geochemical patterns related to gold deposits. A comparative study demonstrated that the hybrid model of t-SNE + RF possesses stronger generalization ability than that of PCA + RF and pure RF. Specifically, after 15 experiments, the mean area under the receiver operator characteristic curve (AUC) values of t-SNE + RF, PCA + RF, and pure RF were 0.83, 0.65, and 0.75, respectively. These results suggest that the hybrid model combining t-SNE and RF can more efficiently recognize geochemical anomalies associated with gold mineralization. Compared with PCA, t-SNE can more effectively identify hidden information in complex and nonlinear geochemical survey data. In addition, it can reduce information redundancy and further improve the efficiency of RF for processing multidimensional geochemical survey data. The high-probability areas obtained by t-SNE + RF showed a strong spatial correlation with known gold deposits, which can provide critical clues for further prospecting in the study area. [ABSTRACT FROM AUTHOR]

The antitumor activities of natural paclitaxel (PTX), semisynthetic docetaxel, and cabazitaxel are highly dependent on their C-13 side chains. Therefore, using natural ergosterol peroxide (EP, 1) as the lead compound, two EP-PTX hybrids (EP-A2 and EP-B2) were prepared and their antitumor activities were evaluated against 4 kinds of human MCF-7, HepG2, HCT-116, and A549 cell lines in vitro. The results showed that both EP-A2 and EP-B2 inhibited the growth of all four kinds of tested tumor cell lines. For paclitaxelresistant MCF-7 cells, both EP-A2 and EP-B2 showed significant inhibitory activity with relatively low IC50 values (9.39 μM and 8.60 μM, respectively). In addition, EP-B2 inhibited the growth of the HepG2 cells (IC50=7.82 μM) more successfully than EP. Preliminary studies of the mechanism suggest that EP-B2 could arrest the G1 phase transition in HepG2 cells. In addition, EPB2 showed an obvious apoptosis-inducing effect in HepG2 cells, as detected by the Annexin V/PI binding assay and the Western blot assay. Hybrid EP-B2 has the potential to become a novel antitumor drug through further study of the mechanism of action and its structural modifications. [ABSTRACT FROM AUTHOR]

Exposure to hexavalent chromium [Cr(VI)] causes human and animal hepatotoxicity. However, it is unclear how Cr(VI) induces hepatotoxicity, nor is it clear which pathways and genes may be involved. This study aimed to identify the key molecular pathways and genes engaged in Cr(VI)-induced hepatotoxicity. Publicly available microarray GSE19662 was downloaded from the Gene Expression Omnibus database. GSE19662 consists of primary rat hepatocyte (PRH) groups treated with or without 0.10 ppm potassium dichromate (PD), with three samples per group. Compared to the control group, a total of 400 differentially expressed genes were obtained. Specially 262 and 138 genes were up- and downregulated in PD-treated PRHs, respectively. Gene ontology (GO) enrichment indicated that those DEGs were primarily engaged in many biological processes, including androgen biosynthetic process, the positive regulation of cell death, the response to activity, the toxic substance and hepatocyte growth factor stimulus, and others. Kyoto Encyclopedia of Genes and Genomes (KEGG) suggested that the DEGs are fundamentally enriched in hepatocellular carcinoma (HCC), hepatitis B, p53, PI3K-Akt, MAPK, AMPK, metabolic pathways, estrogen, cGMP-PKG, metabolic pathways, etc. Moreover, many genes, including UBE2C, TOP2A, PRC1, CENPF, and MKI67, might contribute to Cr(VI)-induced hepatotoxicity. Taken together, this study enhances our understanding of the regulation, prevention, and treatment strategies of Cr(VI)-induced hepatotoxicity. [ABSTRACT FROM AUTHOR]

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Copyright of Mycosystema is the property of Mycosystema Editorial Board and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Background: Seabuckthorn fruits contains many active subtances, among them, the seabuckthorn polysaccharide is one of the main active ingredients, and exhibits diverse bioactivities. The extraction of polysaccharides from seabuckthorn fruits is the most important step for their wide applications. Ultrasound‐assisted aqueous two‐phase extraction (UA‐ATPE) is a promising green method for extracting polysaccharides. Additionally, physicochemical characterization and antioxidant activities can evaluate the potential functions and applications in the food and medicine industries. Results: Based on the single‐factor experiments, 20.70% (w/w) ammonium sulfate ((NH4)2SO4) and 27.56% (w/w) ethanol were determined as the suitable composition for aqueous two‐phase. The optimum conditions of UA‐ATPE obtained by response surface methodology were as follows: ultrasonic power (390 W), extraction time (41 min), liquid‐to‐material ratio (72: 1 mL/g), and the total yield of the polysaccharides reached 34.14 ± 0.10%, The molecular weights of the purified upper‐phase seabuckthorn polysaccharide (PUSP) and the purified lower‐phase seabuckthorn polysaccharide (PLSP) were 65 525 and 26 776 Da, respectively. PUSP and PLSP contained the same six monosaccharides (galacturonic acid, rhamnose, xylose, mannose, glucose and galactose), but with different molar ratios. Furthermore, PUSP and PLSP displayed certain viscoelastic property, had no triple helical structure, possessed different thermal stability, surface morphology and conformation in aqueous solution. PUSP and PLSP displayed strong antioxidant properties by the assays of scavenging ability of ABTS+·, the protection of DNA damage and erythrocyte hemolysis. Conclusion: UA‐ATPE significantly increased the yield of seabuckthorn polysaccharides. PUSP and PLSP were different in many aspects, such as molar ratio, surface shape and antioxidant activities. Seabuckthornpolysaccharides possess great potential in medicine and functional foods. © 2022 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

The Dexing porphyry deposit is the largest porphyry Cu–Mo–Au deposit in South China. Biotite composition can record the physicochemical conditions and evolution history of magmatic-hydrothermal system. Biotite from the Dexing porphyry deposit could be divided to three types: primary magmatic biotite (Bi-M), hydrothermal altered magmatic biotite (Bi-A) and hydrothermal biotite (Bi-H). The temperature of Bi-M and Bi-H range from 719 to 767 °C and 690 to 727 °C, respectively. Both magmatic and hydrothermal biotite have high Fe3+/Fe2+ ratios (from 0.18 to 0.24) and XMg values (from 0.57 to 0.66), indicating a high oxygen fugacity. Bi-M has F lower than Bi-A and Bi-H (up to 0.26 wt%), but has Cl (Cl = 0.18–0.30 wt%) similar to Bi-A and Bi-H (Cl = 0.21–0.35 wt%), suggesting that high Cl/F ratios of early hydrothermal fluid may result from the exsolution from high Cl magma. From potassic alteration zone to phyllic and propylitic alteration zones, Cl decreases with increasing Cu, whereas F increases roughly. Therefore, Cl mostly originate from magma, but enrichment of F possibly results from reaction of fluids and Neoproterozoic strata. Negative correlation between Cl and Cu indicates that Cl might act as an important catalyst during Cu mineralization process. Biotite from Dexing has similar halogen compositions to other porphyry Cu-/Mo deposits in the world. Chlorine contents of hydrothermal fluid may be critical for Cu transportation and enrichment, while consumption of Cl would promote Cu deposition. [ABSTRACT FROM AUTHOR]

The Dongnan Cu–Mo deposit, located in the southeast of the Zijinshan ore field (the largest porphyry–epithermal system in Southeast China), represents the complex magmatic and metallogenesis events in the region. The petrogenesis and metallogenesis of granitoids from the deposit are not determined, especially the interactions between ore-bearing (granodiorite porphyry) and barren samples (granodiorite and diorite). In the paper, the whole rock geochemical features shared a similar affinity to the middle-lower content and revealed that they derived from partial melting of the Cathaysian basement with the contribution of mantle materials, even represented that they generated in the plate subduction; LA-ICP-MS zircon U–Pb ages show that these granodiorites, granodioritic porphyry and diorite, were generated during 114–103 Ma. The ore-bearing samples mostly presented εHf(t) of negative values (peak value is −4 to −3) with old two-stage Hf model ages (tDM2) (peak value is 1.10–1.15 Ga), while the barren sample showed slightly negative εHf(t) (peak value is −1 to 0) values with young tDM2 (peak value is 1.00–1.05 Ga). The value of zircon Ce4+/Ce3+ ratio mostly higher than 450 was first verified for the ore-bearing samples in the Dongnan Cu–Mo deposit, and the values of ore-bearing were found to be higher than those from the barren, which suggests that the ore-bearing formed in more oxidized parental magma with higher oxygen fugacity. Based on the geochemical characteristic of the element and isotope, we concluded that the Early Cretaceous multi-phases magmatic activities, low melting temperature and low pressure of pluton, and high oxygen fugacity of zircon, were the favorable conditions for metallogenesis of Dongnan Cu–Mo deposit. [ABSTRACT FROM AUTHOR]

The Late Paleozoic and Mesozoic tectonic framework of the Nanpanjiang Basin has much been disputed. Herein, the middle-acid volcanic rock, dacite, exposed to the Zhesang gold district, southeast Yunnan Province, has been analyzed. The results show that the dacite belongs to a calc-alkaline series, SiO2 contents range from 62.79 to 76.66 wt%. Zircon SHRIMP U–Pb dating of dacite demonstrates that they were formed in the Early Triassic (247.8 ± 1.7 Ma, MSWD = 1.2). All samples exhibit enrichment in LILE (e.g. Rb, K, Th, and U), and depletion in HFSE (e.g. Nb, Ta, and Ti), which has the geochemical affinity of I-type granite. La–La/Sm and La–La/Yb discrimination diagrams show that the partial melting, mainly of the mafic lower crust, of rocks, plays a major role in the formation process. The dacite has low initial 87Sr/86Sr ratios (0.706954 to 0.708589) and negative εNd(t) values (− 11.77 to − 10.88). Zircons in dacite have εHf(t) values of − 16.2 to − 8.3, and the two-stage Hf model ages are 1799–2301 Ma, mostly concentrated between 1800 and 1900 Ma, indicating that the magma source area is the reconstructed ancient lower crust mixed with some mantle materials, and crystal fractionation process underwent in the late stage of magma migration. This study reveals that the arc-volcanic rocks of the Early Triassic in the southern margin of the Nanpanjiang Basin were formed by the subduction of the Late Paleozoic ocean basin within the border region between China and Vietnam. [ABSTRACT FROM AUTHOR]

The Heilongjiang Jianbiannongchang area is located at the confluence of the Great and Lesser Xing'an Ranges. This area has a complex magmatic and tectonic evolutionary history that has resulted in a complex and diverse geological background for mineralization. In this study, isometric logarithmic ratio (ILR) transformations of Au, Cu, Pb, Zn, and Sb contents were performed in the 1:50,000 soil geochemical data of the Jianbiannongchang area. Robust principal component analysis (RPCA) was conducted based on ILR transformation. The local singularity and spectrum-area (S-A) methods were used to extract information on mineralogic anomalies. The results showed that: (1) the transformed data eliminated the influence of the original data closure effect, and the PC1 and PC2 information obtained by applying RPCA reflected ore-producing element anomalies dominated by Au and Cu. (2) The local singularity method can enhance the information of the local strong and weak slow anomalies. After performing local singularity analysis on PC1 and PC2, the obtained local anomalies reflected the local singularity spatial anomaly patterns related to Cu and Au mineralization in this area, which is an effective method for trapping ore-producing anomalies. (3) Furthermore, the composite anomaly decomposition of PC1 and PC2 was performed using the S-A method, and the screened anomalous and background fields reflect the ore-producing anomalies related to Cu and Au mineralization. This information is in agreement with known Cu and Au mineralization. (4) The geochemical anomalies with mineralization potential were obtained outside the known mineralization sites by integrating the information of ore-producing anomalies extracted by the local singularity and S-A methods, providing the theoretical basis and exploration direction for future exploration in the study area. [ABSTRACT FROM AUTHOR]

The Qieganbulake deposit associated with a mafic–ultramafic–carbonatite complex in the Kuluketage block is not only the world's second-largest vermiculite deposit, but also a medium-size carbonatite-related phosphate deposit. Field observations, radiometric dating results and Sr–Nd–Hf isotopes reveal that the parental magmas of the carbonatite and mafic–ultramafic rocks are cogenetic and formed synchronously at c. 810 Ma. Geochemical characteristics and Sr–Nd–Hf–S isotopes ((87Sr/86Sr)i = 0.70581–0.70710; ϵNd(t) = −0.20 to −11.80; ϵHf(t) = −7.5 to −10.3; δ34S = +0.7 ‰ to +3.0 ‰ (some sulfides with high δ34S values (+3.2 to +6.6) were formed by late hydrothermal sulfur)), in combination with mineral compositions and previous research, strongly indicate that the Qieganbulake mafic–ultramafic–carbonatite complex formed via extensive crystal fractionation/cumulation and liquid immiscibility of a carbonated tholeiitic magma, possibly derived from partial melting of an enriched subcontinental lithospheric mantle previously modified by slab-released fluids and sediment input in a continental rift setting. The coupled enriched Sr–Nd isotopic signatures, in combination with previous research, suggest that the enriched subcontinental lithospheric mantle could have been metasomatized by asthenospheric mantle melts to different degrees. The Qieganbulake carbonatite-related phosphate ores were the products of normal fractional crystallization/cumulation of P–Fe3+ complex enriched carbonatite magma in high oxygen fugacity conditions, which was generated by liquid immiscibility of CO2–Fe–Ti–P-rich residual magma undergoing high differentiation. [ABSTRACT FROM AUTHOR]

Copyright of Biotechnology Bulletin is the property of Biotechnology Bulletin Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Speech Emotion Recognition (SER) is an active area of signal processing research that aims at identifying emotional states from audio speech signals. Applications of SER range from psychological diagnosis to human-computer interaction and as such, a robust framework is needed for accurate classification. To this end, we propose a two-stage hybrid deep feature selection (HDFS) framework that combines deep learning with automated feature engineering for emotion recognition from human speeches, which shines both in terms of accuracy and computational efficiency. Our pipeline extracts self-learned features using a customized Wide-ResNet-50-2 deep learning model from mel-spectrograms of raw audio signals, whose dimensionality is reduced using a hybrid deep feature selection algorithm that comprises a fuzzy entropy and similarity-based feature ranking method, followed by Whale optimization algorithm, which is a popular meta-heuristic optimization algorithm in literature. A k-nearest neighbor classifier is used to classify the optimized feature subset into the respective emotion classes. The proposed pipeline is evaluated on three publicly available SER datasets using a 5-fold cross-validation scheme, where it is found to outperform several state-of-the-art existing works in literature by significant margins thus, justifying the superiority and reliability of the proposed research. The source codes of the proposed method can be found at: https://github.com/soumitri2001/Wrapper-Filter-Speech-Emotion-Recognition. [ABSTRACT FROM AUTHOR]

Background: The pathogenesis of urolithiasis remains unclear, making the development of medications for treatment and prevention stagnant. Randall's plaques (RPs) begin as interstitial calcium phosphate crystal deposits, grow outward and breach the renal papillary surface, acting as attachment for CaOx stones. Since matrix metalloproteinases (MMPs) can degrade all components of extracellular matrix (ECM), they might participate in the breach of RPs. Besides, MMPs can modulate the immune response and inflammation, which were confirmed to be involved in urolithiasis. We aimed to investigate the role of MMPs in the development of RPs and stone formation. Methods: The public dataset GSE73680 was mined to identify differentially expressed MMPs (DEMMPs) between normal tissues and RPs. WGCNA and three machine learning algorithms were performed to screen the hub DEMMPs. In vitro experiments were conducted for validation. Afterwards, RPs samples were classified into clusters based on the hub DEMMPs expression. Differentially expressed genes (DEGs) between clusters were identified and functional enrichment analysis and GSEA were applied to explore the biological role of DEGs. Moreover, the immune infiltration levels between clusters were evaluated by CIBERSORT and ssGSEA. Results: Five DEMMPs, including MMP1, MMP3, MMP9, MMP10, and MMP12, were identified between normal tissues and RPs, and all of them were elevated in RPs. Based on WGCNA and three machine learning algorithms, all of five DEMMPs were regarded as hub DEMMPs. In vitro validation found the expression of hub DEMMPs also increased in renal tubular epithelial cells under lithogenic environment. RPs samples were divided into two clusters and cluster A exhibited higher expression of hub DEMMPs compared to cluster B. Functional enrichment analysis and GSEA found DEGs were enriched in immune-related functions and pathways. Moreover, increased infiltration of M1 macrophages and enhanced levels of inflammation were observed in cluster A by immune infiltration analysis. Conclusion: We assumed that MMPs might participate in RPs and stone formation through ECM degradation and macrophages-mediated immune response and inflammation. Our findings offer a novel perspective on the role of MMPs in immunity and urolithiasis for the first time, and provide potential biomarkers to develop targets for treatment and prevention. [ABSTRACT FROM AUTHOR]

Speech plays an important role among the human communication and also a dominant source of medium for human computer interaction (HCI) to exchange information. Hence, it has always been an important research topic in the fields of Artificial Intelligence (AI) and Machine Learning (ML). However, in the traditional machine learning approach, when the dimension of the feature vector becomes quite large, it takes a huge amount of storage space and processing time for the learning algorithms. To address this problem, we have proposed a hybrid wrapper feature selection algorithm, called CEOAS, using clustering-based Equilibrium Optimizer (EO) and Atom Search Optimization (ASO) algorithm for recognizing different human emotions from speech signals. We have extracted Linear Prediction Coding (LPC) and Linear Predictive Cepstral Coefficient (LPCC) from the audio signals. Our proposed model helps to reduce the feature dimension as well as improves the classification accuracy of the learning model. The model has been evaluated on four standard benchmark datasets namely, SAVEE, EmoDB, RAVDESS, and IEMOCAP and impressive recognition accuracies of 98.01%, 98.72%, 84.62% and 74.25% respectively have been achieved which are better than many state-of-the-art algorithms. [ABSTRACT FROM AUTHOR]

Most porphyry Cu deposits are formed in magmatic arc settings, but some occur in non-arc environments, such as intracontinental settings. The petrogenesis of fertile magmas for porphyry Cu deposits formed in intracontinental settings is still ambiguous. To address this issue, we performed an integrated study of the late Mesozoic porphyry Cu deposits in the South Qinling Orogenic Belt. Zircon U–Pb ages indicate that these late Mesozoic porphyry Cu deposits were formed at 149–142 Ma, in a postcollisional intracontinental setting. εNd(t) (− 4.5 to − 2.7), initial 87Sr/86Sr (0.7046 to 0.7084), and zircon εHf(t) values (− 3.8 to + 2.2) of the late Mesozoic ore-forming and barren rocks suggest that both originate from Meso-Neoproterozoic juvenile lower crust. Whole-rock geochemical and isotopic characteristics indicate that the ore-forming rocks could be formed by the delamination of thickened juvenile lower crust or by the reaction of mantle with normal juvenile lower crust. The barren rocks could be formed by the partial melting of thickened or normal juvenile lower crust. Whole-rock petrochemistry and reversed anorthite contents and Sr isotope data of zoned plagioclase crystals indicate that the mafic magma was recharged into the ore-forming magma chamber. Due to the injection of mafic magma, the ore-forming rocks obtained higher oxygen fugacity, volatiles, water, sulfur, and Cu contents than the barren rocks. According to the regional tectonic evolution, the late Mesozoic porphyry Cu deposits in the South Qinling Orogenic Belt were formed in an extensional environment due to transformation of the tectonic regime. Large-scale lithospheric extension caused asthenospheric mantle upwelling and crust-mantle interaction, providing the crucial metallogenic conditions. Moreover, the injection of mantle-derived mafic magma into the normal magma is a key factor in the formation of the late Mesozoic porphyry Cu deposits in the SQB and similar porphyry systems in an intracontinental setting. [ABSTRACT FROM AUTHOR]

The Baishuizhai, Shituling and Zhushanxia deposits from the Xiazhuang district represent to date the only known occurrences of early Yanshanian (Middle to Upper Jurassic) granite-related high-temperature hydrothermal uranium deposits (175–145 Ma) in the Nanling Metallogenic Belt, South China. Whole-rock geochemistry of ore samples combined with chemical and mineralogical signatures of the hydrothermal phases associated with the U mineralisation characterised a coeval potassic and propylitic alteration fingerprint: (i) the potassic alteration is defined by Na and Ca depletion of the granitic host rock and precipitation of adularia, dioctahedral Fe-muscovite, biotite and secondary quartz; and (ii) the propylitic alteration is marked by whole-rock enrichment in Ca, Fe, Mg, Mn and Ti mainly associated with the precipitation of (Mn)-epidote, Fe-chlorite, fluorapatite, titanite, calcite, APS and Fe-Cu-Pb-Cd-Bi-Mo-sulfide minerals. The high-temperature conditions of the hydrothermal system was demonstrated by the typologies of alteration such as greisen, chlorite geothermometry giving temperature estimates of the ore fluid ranging from 316 to 455°C, minor W mineralisation and the high Zr contents in titanite. Besides, high Rb, Ba, Be, Y, Nb, W, Ta and Mo contents in ore samples, mineral assemblages and chemical signatures of the hydrothermal phases showed evidence for the alteration of fractionated felsic granitic host rocks and the contribution of enriched magmatic-derived fluids. Therefore, these characteristics define a magmatic-hydrothermal genetic model directly related to the intrusion of early Yanshanian granites in the Nanling belt. In this new metallogenic model, highly fractionated high-K calc-alkaline A2-type granitic plutons have provided magmatic fluids, heat and metal sources to the early Yanshanian high-temperature hydrothermal U system. Uranium (±W-Sn-Nb-Ta-Li)-rich fluids were derived from fractionated peraluminous residual silicate melts. Uranium was enriched in a high-temperature, highly saline, F-rich, acid and reducing fluid, and dominantly carried as fluoride complexes. This mineralising fluid percolated in the Indosinian U-rich host granites within the cupolas of early Yanshanian granites and produced characteristic propylitic and potassic (including greisen) hydrothermal alteration. During the hydrothermal alteration, the pH and T variations of the mineralising fluid and the subsequent precipitation of F- and P-bearing hydrothermal phases induced the destabilisation of U complexes, winch eventually triggered the deposition of the U mineralisation. [ABSTRACT FROM AUTHOR]

As the youngest segment of the Central Asian Orogenic Belt, the Mongol-Okhotsk Belt is critical for understanding the final amalgamation of East Asia. However, whether the Mongol-Okhotsk Ocean closed in a scissor-like manner remains controversial, in part because the spatial and temporal change of the subduction-related magmatic records are not well constrained. This paper presents new zircon U–Pb ages and whole-rock geochemical data for the Permian–Triassic magmatic rocks in the Middle Gobi belt. Zircon U–Pb dating indicates that the Luus dacite, Luus andesite, East Monhhaan granite and South Monhhaan rhyolite yielded U–Pb ages of 272 ± 4 Ma, 221 ± 2 Ma, 256 ± 2 Ma and 229 ± 2 Ma, respectively. The Luus dacite and South Monhhaan rhyolite show enrichment in LREE and LILE and negative Nb, Ta and Ti anomalies, indicating genesis in a subduction zone setting. The Luus andesite shows adakite geochemical features and was likely formed from partial melting of subducted oceanic crust. The East Monhhaan granite is of peraluminous S-type granite. These Permian–Triassic magmatic rocks are likely formed in an active margin related to the southward subduction of the Mongol-Okhotsk Ocean. Based on available data, we suggest that there is no significant age difference from west to east for the subduction-related magmatic complex at the southern margin of the Mongol-Okhotsk Ocean. Various Late Triassic subduction-related records in central Mongolia indicate the western segment of the Mongol-Okhotsk Ocean was finally closed during Jurassic, nearly contemporary with final closure of the eastern segment. Thus, we argue that the Mongol-Okhotsk Ocean was not likely closed in a scissor-like pattern as previously thought. [ABSTRACT FROM AUTHOR]

The tectonic evolution of the South Tianshan Orogenic Belt has long been a focus of geological research. As the intermontane basin of the South Tianshan, the Kumishi Basin has recorded important information relating to the evolution of the South Tianshan Orogenic Belt. The provenance and structural evolution of the Kumishi Basin was analyzed by U–Pb dating of late Quaternary detrital zircon to provide an important information record for the evolution of the South Tianshan Orogenic Belt. The zircon U–Pb ages of 62 effective zircons in the samples were measured by LA-ICP-MS. The zircon ages mainly ranged from ~ 461–422 Ma, ~ 416–366 Ma, to ~ 358–251 Ma. The Th/U ratio showed that the zircons in the Kumishi Basin were mainly magmatic. Based on the analysis of the rock properties and age composition of the potential provenance, it was speculated that the detrital zircons aged ~ 461–422 Ma and ~ 416–366 Ma were related to the subduction of the South Tianshan ocean, and the detrital zircons aged ~ 358–251 Ma were controlled by the magmatic tectonic activity around the basin during the Palaeozoic (from the Carboniferous to the Permian). A comparison of these ages with the tectonic events around the basin indicated that the extensive detrital zircon ages recorded the evolution of the South Tianshan orogenic belt. [ABSTRACT FROM AUTHOR]

The carbonate-hosted Pb–Zn deposits in the Sichuan–Yunnan–Guizhou (SYG) triangle region are important Indosinian deposits in South China. The Tianbaoshan deposit is a typical large Pb–Zn deposit in the SYG area and occurs as pipe-like type, hosted by Sinian dolostone. It contains ∼26 Mt Zn–Pb ore (7.76–10.09 % Zn, 1.28–1.50 % Pb and 93.6 g t−1 Ag) and >0.1 Mt Cu ore (2.55 % Cu). In this study, the detailed mineral textures, mineral chemical and sulphur isotopic compositions of the various sulphides have been analysed to constrain the abnormal enrichment mechanism and mineralization relationship. Four mineralization stages have been recognized: Stage 1, minor early pyrite (Py1) with relics and infill of intergranular dolomite or quartz grains; Stage 2, Cu mineralization with coarse-grained, elliptical crystal chalcopyrite (Cp1); (3) Stage 3, Zn mineralization with dark fine-grained sphalerite (Sph1) and light coarse-grained sphalerite (Sph2); and (4) Stage 4, as represented by a quartz–calcite assemblage with galena, minor pyrite (Py2) and chalcopyrite (Cp2). The petrography of the sulphide minerals (Py1, Cp1, Sph1 and Sph2) demonstrates a mutual inclusion relationship. The nature of this relationship from core to rim and their similar sulphur isotope values (5.5–8.3 ‰) indicates a single sulphur source, suggesting that the different mineralization types are the result of different stages of a continuous hydrothermal system. Sphalerite geothermometer study suggests that sphalerite in the Tianbaoshan deposit formed in a low-temperature (<200 °C) hydrothermal system. The low concentrations of Mn and In, low In/Ge ratios and high Fe/Cd ratios in the sphalerite are consistent with those of Mississippi Valley-type (MVT) deposits, but different from those of magmatism-related deposits (e.g. epithermal, skarn and VMS deposits). The positive δ34S values for Py1 (5.1–7.9 ‰), Cp1 (5.1–7.2 ‰), Sph1 (4.7–7.4 ‰), Sph2 (3.9–8.7 ‰), Py2 (4.4–9.3 ‰) and Cp2 (5.0–6.8 ‰) indicate a sulphur source from thermochemical reduction of coeval seawater sulphate. Widely developed dissolved textures (caverns and breccias) with massive sulphide infillings and deformed host rock remnants suggest that replacement of host dolostones by ore fluids was volumetrically significant and the ore formed nearly simultaneously with the cavities. The Tianbaoshan deposit is a typical MVT deposit, which resulted from mixing of a H2S-rich fluid and a metal-rich fluid, with thermochemical sulphate reduction occurring before ore precipitation rather than during ore precipitation. [ABSTRACT FROM AUTHOR]

Background: The prognosis of B-cell acute lymphoblastic leukemia (B-ALL) has improved significantly with current first-line therapy, although the recurrence of B-ALL is still a problem. Toll-like receptor 9 (TLR9) agonists have shown good safety and efficiency as immune adjuvants. Apart from their immune regulatory effect, the direct effect of TLR9 agonists on cancer cells with TLR9 expression cannot be ignored. However, the direct effect of TLR9 agonists on B-ALL remains unknown. Methods: We discussed the relationship between TLR9 expression and the clinical characteristics of B-ALL and explored whether CpG 685 exerts direct apoptotic effect on B-ALL without inhibiting normal B-cell function. By using western blot, co-immunoprecipitation, immunofluorescence co-localization, and chromatin immunoprecipitation, we explored the mechanism of the apoptosis-inducing effect of CpG 685 in treating B-ALL cells. By exploring the mechanism of CpG 685 on B-ALL, the predictive biomarkers of the efficacy of CpG 685 in treating B-ALL were explored. These efficiencies were also confirmed in mouse model as well as clinical samples. Results: High expression of TLR9 in B-ALL patients showed good prognosis. C-MYC-induced BAX activation was the key to the effect of CpG oligodeoxynucleotides against B-ALL. C-MYC overexpression promoted P53 stabilization, enhanced Bcl-2 associated X-protein (BAX) activation, and mediated transcription of the BAX gene. Moreover, combination therapy using CpG 685 and imatinib, a BCR-ABL kinase inhibitor, could reverse resistance to CpG 685 or imatinib alone by promoting BAX activation and overcoming BCR-ABL1-independent PI3K/AKT activation. Conclusion: TLR9 is not only a prognostic biomarker but also a potential target for B-ALL therapy. CpG 685 monotherapy might be applicable to Ph− B-ALL patients with C-MYC overexpression and without BAX deletion. CpG 685 may also serve as an effective combinational therapy against Ph+ B-ALL. Key points: TLR9 is not only a prognostic biomarker but also a potential target for B-ALL therapy. C-MYC-mediated BAX activation leads to CpG 685-induced apoptosis in B-ALL. [ABSTRACT FROM AUTHOR]

The Gejiu ore district (~ 3.2 Mt Sn) is located in eastern Yunnan Province, southwest China, and is one of the largest Sn polymetallic ore districts in the world. Athough it has been widely studied, the petrogenesis of ore-related granites is still unclear. In this paper, we present petrological, geochemical, and geochronological data on the granites associated with the Kafang Cu–Sn deposit in the Gejiu ore district (65 Mt Cu ore at a grade of 1.2% and 32 Mt Sn ore at a grade of 0.6%). We use these data to constrain the source, evolution, oxygen fugacity, and tectonic setting of the granitic magmatism. Zircon U–Pb dating yielded an age of 82.8 ± 0.6 Ma for the Kafang granite. The high zircon δ18O values (7.45–9.74‰; mean = 8.80‰) and narrow range of εNd(t) values (–9.0 to –7.7) of the Kafang granite indicate a highly evolved S-type granite derived by partial melting of metamorphic basement rocks of the Jiangnan orogenic belt. Rayleigh fractional crystallization modeling, along with the increase in Hf and Sn contents and decrease in Eu/Eu* values of zircons, record extensive fractional crystallization, and Sn enrichment during magmatic evolution. The Kafang granite was relatively reduced, as evidenced by low zircon Ce/Ce* (10.0–366; mean = 171), (Ce/Nd)N (0.76–8.32; mean = 4.41), △FMQ (–2.5 to 1.2) values, and Fe3+-depleted biotite compositions (Fe3+/(Fe3+ + Fe2+) = 0–0.10), which were favorable for Sn mineralization but not for Cu mineralization. Copper in the Kafang deposit may not have been derived from the granite. Our results suggest that biotite and zircon geochemical compositions, particularly biotite Mg# and A/CNK values and zircon Hf contents, Eu anomalies, and Ce/Ce* and (Ce/Nd)N ratios, are robust tracers of different types of magmatic-hydrothermal ore deposits (i.e., Cu, Mo, W, and Sn). Late Cretaceous magmatism in the Gejiu region and other areas along the southern margin of South China formed an E–W-trending igneous belt that was likely related to northward subduction of the Neo-Tethyan plate rather than northwestward subduction of the Paleo-Pacific plate. [ABSTRACT FROM AUTHOR]

The Dongping gold deposit, located near the northern margin of the North China Craton, contains ore bodies spatially associated with the Devonian Shuiquangou syenite, Cretaceous Shangshuiquan granite, and Archean metamorphic rocks. Major and trace elements and S–Pb isotopes of pyrite from two stages of gold-quartz veins and wall rocks were used to constrain the composition of hydrothermal fluids and metal sources. Stage-1 (early) pyrites are euhedral to subhedral, medium- to coarse-grained, and have low gold contents. Py1a is homogeneous with few fractures, whereas Py1b, which occurs on the edges of Py1a, is porous and has higher metal contents. Stage-2 (late) pyrites are mostly anhedral to subhedral and have smaller grain sizes and higher gold contents than Stage 1. Py2a occurs with sulfide minerals such as galena and chalcopyrite, and Py2b is porous and has the highest gold content (up to 1839 ppm) and smallest grain size. All pyrite samples yield negative δ34S values (− 7.5 to − 3.5‰), reflecting oxidized conditions during mineralization. The ~ 2‰ decrease in δ34S values from Stage 1 (− 4.3‰, − 4.9‰) to Stage 2 (− 7.0‰, − 6.4‰) may reflect a change in the fluid source and/or an increase in fO2. The Pb isotope composition of Stage-1 pyrite is suggestive of a mantle source similar to that of the Shuiquangou syenite, whereas Stage-2 pyrite has more radiogenic Pb isotopic compositions suggestive of an Archean metamorphic source. Combined with previous studies, our trace element and isotopic results indicate that the two stages of pyrite had different sources, with Stage-2 pyrite being more strongly influenced by metasedimentary rocks. We propose that the early stage of low-grade gold mineralization was related to emplacement of the Devonian Shuiquangou syenite, whereas the late stage of high-grade gold mineralization was related to emplacement of the Cretaceous Shangshuiquan granite and leaching of gold from Archean metamorphic rocks. [ABSTRACT FROM AUTHOR]

The Wulong gold deposit (> 80 t Au) is located at the northeastern margin of the North China Craton (NCC). Gold in the most economically important quartz veins (Stages 2 and 3) is associated with a varied assemblage of Bi and Te minerals. Stage 2 is characterized by, in a temporal order, native gold-native bismuth-maldonite-hedleyite, bismuthinite-Bi-sulfotellurides, electrum-hessite-Bi-Pb-Ag sulfosalts, Bi-Pb sulfosalts, and Bi-Pb-sulfotellurides. All of these minerals except maldonite, electrum, hessite, and Bi-sulfosalts are present in Stage 3 veins, which also contain jonassonite and unnamed minerals with stoichiometry of Bi8Te3 and Bi5Te3. These complex Bi mineral assemblages resulted from changes in Pb, Ag, Te and Bi concentrations in reduced hydrothermal fluids both locally and temporally, from Stage 2 to 3. Texturally, approximately 85% of the gold grains are associated with almost all Bi minerals in each main-stage mineralization. Quartz-vein ores from Stages 2 and 3 have high Bi concentrations (up to 7332 ppm) and show a positive correlation between Bi and Au, with Bi/Au ratios > 10. These textural and geochemical associations, together with the occurrence of numerous droplet-like blebs and small inclusion trails of native bismuth and Bi-tellurides with native gold, maldonite, or jonassonite, suggest that Bi-rich melts may have formed from the hydrothermal fluids of Stages 2 and 3, and acted as an Au scavenger in a complex Bi-Au-Pb-Ag-Te system. Hence, the intimate association of Bi and Au at Wulong is the result of Au enrichment via the liquid bismuth collector mechanism. Unlike Wulong, however, other deposits in the NCC, such as Yangzhaiyu (Xiaoqinling district), Guilaizhuang (Jiaodong district) and Dongping (Jidong district), are characterized by low Bi concentrations, and are much richer in Te than Bi, so these systems could not generate low-melting point Bi-rich polymetallic melts. The low-sulfur Bi-Au-Pb-Ag-Te association at Wulong is consistent with that observed in reduced intrusion-related gold systems elsewhere and suggests that hydrothermal fluids may have been derived from the co-located Early Cretaceous diorite-granite porphyry dyke swarm. [ABSTRACT FROM AUTHOR]

The large to middle-sized magmatic Ni–Cu sulfide deposits are spatially situated in the eastern portion of Eastern Tianshan, whereas those in the western portion have been poorly understood due to their quantity and scale. The Haibaotan Ni–Cu sulfide occurrence is newly discovered in the western portion of Eastern Tianshan, which provides an opportunity for understanding how its magmatic conduit system was generated and evolved. The Haibaotan mafic–ultramafic intrusion is dominated by peridotite, pyroxenite, olivine gabbro, and gabbro, and sulfide orebodies occur mainly within gabbro. Gabbro from the Haibaotan intrusion is dated at 315.5 ± 1.9 Ma, which suggests that the Haibaotan intrusion is generated in a subduction evironment. The age is much earlier than the emplacement of other mineralized mafic–ultramafic intrusions (~ 280 Ma) in Eastern Tianshan. High zircon εHf(t) values (+ 7.09 to + 18.44) indicate that the parental magmas of the Haibaotan intrusion have been derived from a metasomatized mantle source. Additionally, mafic–ultramafic rocks in the Haibaotan intrusion exhibit enrichment of large ion lithophile elements (LILE) and light rare earth elements (LREE), together with a depletion of Zr, Ti, and Nb, which is indicative of a subduction-modified mantle source. Core–rim variations of olivine forsterite (Fo) and Ni contents imply that the Haibaotan intrusion resulted from successive magma pulses, and the variable PGE tenors reflect that the sulfide droplets scavenged metals from multiple magma pulses. The low Se/S ratios of sulfide mineralization suggest that the addition of crustal sulfur triggered sulfide segregation in the shallow magma conduit system. The evolution history of the Haibaotan magma conduit system meets the requirements for generating a magmatic Ni–Cu deposit. This study highlights that the subduction environments are favorable for the formation of magmatic sulfide deposits in Eastern Tianshan. [ABSTRACT FROM AUTHOR]

The Dashuigou tellurium deposit is the world's only known independent tellurium deposit. By restoring metamorphic rocks' protolith, we seek to understand not only the development and evolution trajectory of the region but also the origin of the relevant deposits. While there are many ways to restore metamorphic rocks' protolith, we take the host metamorphic rocks of Dashuigou tellurium deposit and leverage various petrochemical eigenvalues and related diagrams previously proposed to reveal the deposit's host metamorphic rocks' protolith. The petrochemical eigenvalues include molecular number, Niggli's value, REE parity ratio, CaO/Al2O3 ratio, Fe3+/(Fe3+ + Fe2+) ratio, chondrite-normalized REE value, logarithmic REE value, various REE eigenvalues including scandium, Eu/Sm ratio, total REE amount, light and heavy REEs, δEu, Eu anomaly, Sm/Nd ratio, and silicon isotope δ30SiNBS−28‰, etc. The petrochemical plots include ACMs, 100 mg-c-(al + alk), SiO2-(Na2O + K2O), (al + fm)-(c + alk) versus Si, (FeO + Fe2O3 + TiO)–Al2O3–MgO, c-mg, Al2O3–(Na2O + K2O), chondrite-normalized REE model, La/Yb-REE, and Sm/Nd ratio, etc. On the basis of these comprehensive analyses, the following conclusions are drawn, starting from the many mantle-derived types of basalt developed in the study area of different geological ages, combined with the previously published research results on the deposit's fluid inclusions and sulfur and lead isotopes. The deposit is formed by mantle degassing in the form of a mantle plume in the late Yanshanian orogeny. The degassed fluids are rich in nano-scale substances including Fe, Te, S, As, Bi, Au, Se, H2, CO2, N2, H2O, and CH4, which are enriched by nano-effect, and then rise to a certain part of the crust in the form of mantle plume along the lithospheric fault to form the deposit. The ultimate power for tellurium mineralization was from H2 flow with high energy, which was produced through radiation from the melted iron of the Earth's outer core. The H2 flow results in the Earth's degassing, as well as the mantle and crust's uplift. [ABSTRACT FROM AUTHOR]

Southwestern Guizhou province is one of China's most important distribution areas of Carlin-type gold deposits. The Nibao deposit is a typical gold deposit in southwestern Guizhou. To elucidate the genesis of the Nibao gold deposit, establish a metallogenic model, and guide prospecting prediction, we systematically collected previously reported geological, geochemical, and dating data and discussed the genesis of the Nibao gold deposit, based on which we proposed the metallogenic model. Earlier works show that the Nibao anticline, F1 fault, and its hanging wall dragged anticline (Erlongqiangbao anticline) were formed before or simultaneously with gold mineralization, while F2, F3, and F4 faults postdate gold mineralization. Regional geophysical data showed extensive low resistivity anomaly areas near the SBT (the product of tectonic slippage and hydrothermal alteration) between the P2/P3 and the strata of the Longtan Formation in the SSE direction of Nibao anticline in the lower plate of F1 and hanging wall dragged anticline (Erlongqiangbao anticline), and the anomaly areas are distributed within the influence range of anticlines. Simultaneously, soil and structural geochemistry show that F1, Nibao anticline, Erlongqiangbao anticline, and their transition areas all show good metallogenic elements (Au, As, and S) assemblage anomalies, with good metallogenic space and prospecting possibilities. There are five main hypotheses about the source of ore-forming fluids and Au in the Nibao gold deposit: (1) related to the Emeishan mantle plume activity; (2) source from the Emeishan basalt; (3) metamorphic fluid mineralization; (4) basin fluid mineralization; (5) related to deep concealed magmatic rocks; of these, the mainstream understanding is the fifth speculation. It is acknowledged that the ore-forming fluids are hydrothermal fluids with medium–low temperature, high pressure, medium–low salinity, low density, low oxygen fugacity, weak acidity, weak reduction, and rich in CO2 and CH4. The fluid pressure is 2–96.54 MPa, corresponding to depths of 0.23–3.64 km. The dating results show that the metallogenic age is ~141 Ma, the extensional tectonic environment related to the westward subduction of the Pacific Plate. Based on the above explanation, the genetic model related to deep concealed magmatic rocks of the Nibao gold deposit is established, and favorable prospecting areas are outlined; this is of great significance for regional mineral exploration and studying the genesis of gold deposits. [ABSTRACT FROM AUTHOR]

This study presents zircon U–Pb geochronology and Hf and O isotope data for granitic rocks in the Zijinshan ore field, southwestern Fujian Province, China. The intrusive rocks comprise monzogranite, granite and granodiorite. The magmatic zircon U–Pb ages from these granitic rocks can be divided into four episodes: episodes 1 (157.9–159.9 Ma) and 2 (141 Ma) in the Late Jurassic and episodes 3 (108.1–103.2 Ma) and 4 (97.5–99.7 Ma) in the Middle and Late Cretaceous, respectively. Patterns of rare-earth elements (REE) show enrichment in light REE and obvious negative Eu anomalies. These rocks are also enriched in Rb, Th, U, La, Ce, Nd and Hf, and depleted in Ba, Nb, Sr, P and Ti. The increasing La/Yb ratio and decreasing heavy REE content with decreasing age may imply an increasing contribution of mantle-derived materials from the Late Jurassic to Cretaceous. The zircon ϵ Hf(t) and δ18O values, ranging from −37.7 to −2.8 and 12.0 ‰ to 6.3 ‰, respectively, indicate that the lower crust is an important source of granitic rocks. There was a significant increase in ϵ Hf(t) values and a decrease in δ18O values in the younger magmatic episodes (3 and 4), which ranged from −11.4 to −0.6 and 10.7 to 6.3 ‰, respectively. This suggests an increasing contribution of mantle-derived magma to the crustal melts from the Late Jurassic to late Early Cretaceous in response to the changing regional tectonic setting from compression to extension and an increasing interaction between the crust and mantle. [ABSTRACT FROM AUTHOR]

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Titanium (Ti) alloys suffer from poor mechanical strength and inferior wear resistance. Herein, we introduced the calcium hexa boride (CaB6) into Ti matrix to manufacture high-strength and high-wear in situ Ti matrix composites (TMCs) by powder metallurgy method. The effects of CaB6 addition on the microstructure, mechanical and tribological properties of TMCs were studied. Results show that the formation of hard in situ TiB and nano-size CaTiO3 particles contributes to a remarkable refinement of average grain size from 163 μm in pure Ti to 74 μm in Ti–1.0 wt.% CaB6 composite. The hardness is significantly increased from 191 ± 15 HV in pure Ti to 321 ± 13 HV in Ti–0.8 wt.% CaB6 composite. The Ti–0.8 wt.% CaB6 composite obtains the best comprehensive mechanical properties with an ultimate tensile strength of 740.3 ± 28.3 MPa, yield strength of 598.4 ± 23.1 MPa and elongation of 10.6 ± 1.5% and displays the optimal wear resistance with friction coefficients of 0.45, 50% less than pure Ti, under constant conditions (3 N, 0.03 m/s). [ABSTRACT FROM AUTHOR]

Many workers accept a metamorphic model for orogenic gold ore formation, where a gold-bearing aqueous-carbonic fluid is an inherent product of devolatilization across the greenschist-amphibolite boundary with the majority of deposits formed within the seismogenic zone at depths of 6–12 km. Fertile oceanic rocks that source fluid and metal may be heated through varied tectonic scenarios affecting the deforming upper crust (≤ 20–25 km depth). Less commonly, oceanic cover and crust on a downgoing slab may release an aqueous-carbonic metamorphic fluid at depths of 25–50 km that travels up-dip along a sealed plate boundary until intersecting near-vertical structures that facilitate fluid migration and gold deposition in an upper crustal environment. Nevertheless, numerous world-class orogenic gold deposits are alternatively argued to be products of magmatic-hydrothermal processes based upon equivocal geochemical and mineralogical data or simply a spatial association with an exposed or hypothesized intrusion. Oxidized intrusions may form gold-bearing porphyry and epithermal ores in the upper 3–4 km of the crust, but their ability to form economic gold resources at mesozonal (≈ 6–12 km) and hypozonal (≈ > 12 km) depths is limited. Although volatile saturation may be reached in magmatic systems at depths as deep as 10–15 km, such saturation doesn't indicate magmatic-hydrothermal fluid release. Volatiles typically will be channeled upward in magma and mush to brittle apical roof zones at epizonal levels (≈ < 6 km) before large pressure gradients are reached to rapidly release a focused fluid. Furthermore, gold and sulfur solubility relationships favor relatively shallow formation of magmatic-hydrothermal gold systems; although aqueous-carbonic fluid release from a magmatic system below 6 km would generally be diffuse, even if in cases where it was somehow better focused, it is unlikely to contain substantial gold. Where reduced intrusions form through assimilation of carbonaceous crustal material, subsequent high fluid pressures and hydrofracturing have been shown to lead to development of sheeted veins and greisens at depths of 3–6 km. These products of reduced magmatic-hydrothermal systems, however, typically form Sn and or W ores, with economic low grade gold occurrences (< 1 g/t Au) being formed in rare cases. Thus, whereas most moderate- to high-T orogens host orogenic gold and intrusions, there is no genetic association. [ABSTRACT FROM AUTHOR]