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Abstract Background Breast cancer causes hundreds of thousands of deaths each year worldwide. The early stage diagnosis and treatment can significantly reduce the mortality rate. However, the traditional manual diagnosis needs intense workload, and diagnostic errors are prone to happen with the prolonged work of pathologists. Automatic histopathology image recognition plays a key role in speeding up diagnosis and improving the quality of diagnosis. Methods In this work, we propose a breast cancer histopathology image classification by assembling multiple compact Convolutional Neural Networks (CNNs). First, a hybrid CNN architecture is designed, which contains a global model branch and a local model branch. By local voting and two-branch information merging, our hybrid model obtains stronger representation ability. Second, by embedding the proposed Squeeze-Excitation-Pruning (SEP) block into our hybrid model, the channel importance can be learned and the redundant channels are thus removed. The proposed channel pruning scheme can decrease the risk of overfitting and produce higher accuracy with the same model size. At last, with different data partition and composition, we build multiple models and assemble them together to further enhance the model generalization ability. Results Experimental results show that in public BreaKHis dataset, our proposed hybrid model achieves comparable performance with the state-of-the-art. By adopting the multi-model assembling scheme, our method outperforms the state-of-the-art in both patient level and image level accuracy for BACH dataset. Conclusions We propose a novel compact breast cancer histopathology image classification scheme by assembling multiple compact hybrid CNNs. The proposed scheme achieves promising results for the breast cancer image classification task. Our method can be used in breast cancer auxiliary diagnostic scenario, and it can reduce the workload of pathologists as well as improve the quality of diagnosis.

The circadian misalignment of the gut microbiota caused by unusual eating times in adult animals is related to disease development. However, whether the composition and diurnal rhythm of gut microbiota can be optimized by synchronizing the window period of eating with natural eating habits to reduce the risk of diarrhea remains unclear, especially in growing animals. In this study, 108 5-week-old weaned rabbits (nocturnal animals) were randomly subjected to daytime feeding (DF) and night-restricted feeding (NRF). At age 12 weeks, six rabbits were selected from each group, and caecum and cecal contents, as well as serum samples were collected at 4-h intervals during 24 h. Overall, NRF was found to reduce the risk of diarrhea in growing rabbits, improved the diurnal rhythm and abundance of beneficial microorganisms, along with the production of beneficial metabolites, whereas reduced the abundance of potential pathogens (Synergistes, Desulfovibrio, and Alistipes). Moreover, NRF improved diurnal rhythm of tryptophan hydroxylase isoform 1 and serotonin. Furthermore, NRF strengthened the diurnal amplitude of body core temperature, and promoted the diurnal expression of intestinal clock genes (BMAL1, CLOCK, REV-ERBα, and PER1), and genes related to the regulation of the intestinal barrier (CLAUDIN-1), and intestinal epithelial cell self-proliferation and renewal (BMI1). In vitro simulation experiments further revealed that synchronization of microbial-driven serotonin rhythm and eating activity-driven body temperature oscillations, which are important zeitgebers, could promote the diurnal expression of clock genes and CLAUDIN-1 in rabbit intestinal epithelial cells (RIEC), and enhance RIEC proliferation. This is the first study to reveal that NRF reprograms the diurnal rhythm of the gut microbiome, promotes the diurnal expression of clock genes and tight junction genes via synchronization of microbial-driven serotonin rhythm and eating activity-driven body temperature oscillations, thereby improving intestinal health and reducing the risk of diarrhea in growing rabbits. Collectively, these results provide a new perspective for the healthy feeding and management of growing animals.

Platelets are essential components in the tumor microenvironment. For decades, clinical data have demonstrated that cancer patients have a high risk of thrombosis that is associated with adverse prognosis and decreased survival, indicating the involvement of platelets in cancer progression. Increasing evidence confirms that cancer cells are able to induce production and activation of platelets. Once activated, platelets serve as allies of cancer cells in tumor growth and metastasis. They can protect circulating tumor cells (CTCs) against the immune system and detachment-induced apoptosis while facilitating angiogenesis and tumor cell adhesion and invasion. Therefore, antiplatelet agents and platelet-based therapies should be developed for cancer treatment. Here, we discuss the mechanisms underlying the bidirectional cancer-platelet crosstalk and platelet-based therapeutic approaches.

During the flotation separation process of bastnaesite, it is difficult to separate bastnaesite from fluorite effectively. In this present study, sodium silicate (SS) can effectively improve the flotation separation effect of bastnaesite and fluorite in salicylhydroxamic acid (SHA) systemasa. Through relevant analyses, such as Zeta potential measurements, adsorption capacity tests, Fourier transform infrared (FTIR) spectroscopic analyses and X-ray photoelectron spectroscopy (XPS) tests, the selective suppressor of SS on fluorite was proven. At pH 10, the single mineral flotation results show that with the increase of SS dosage, the flotation recovery of fluorite rapidly decreases from 61.5% to 35.31%, while the flotation rate of bastnaesite is still high (recovery is 80.02%). Then, the experiment of artificial mixed ore proved that the flotation separation of fluorite and bastnaesite was effective under the appropriate dosage of inhibitor. The results of potentiodynamic measurement and an adsorption capacity test showed that the SiOOH3− structure of SS more easily reacted with fluorite, which further prevented the adsorption of SHA on the fluorite surface. FTIR test results and XPS analysis further showed that SS had a strong binding effect with the Ca site on the fluorite surface, but a weak binding effect with the Ce site on the bastnaesite surface. Consequently, SS can be used as an effective inhibitor in the flotation separation of fluorite and bastnaesite.

Recently, evidence has shown that GOT1 expression is upregulated in pancreatic cancer tissues and promotes cancer development, but the specific mechanism remains unclear. We found that GOT1 expression was upregulated in pancreatic cancer cell-derived exosomes. When PANC-1 cells were incubated with exosomes alone or transfected together with si-GOT1, we found that exosomes enhanced cell proliferation, invasion and migration, promoted ferroptosis, and si-GOT1 reversed the effects of exosomes. The results of online bioinformatics database analysis indicated that CCR2 was a potential binding protein of GOT1 and is highly expressed in pancreatic cancer tissues. PANC-1 cells were transfected with pcDNA-CCR2 or si-CCR2, and it was found that pcDNA-CCR2 enhanced cell proliferation, invasion and migration, promoted ferroptosis, and si-CCR2 had an opposite effect. Next, exosome-treated cells were transfected with si-GOT1 alone or together with pcDNA-CCR2, and we found that exosomes promoted CCR2 expression, promoted cell proliferation and invasion, and inhibited ferroptosis, the transfection of si-GOT1 abolished the effect of exosomes, and the transfection of pcDNA-CCR2 again reversed the effect of si-GOT1. Furthermore, when exosome-treated cells were transfected with si-GOT1 alone or co-incubated with Nrf2 activator NK-252, we found that si-GOT1 reversed the promoting effect of exosomes on Nrf2 and HO-1 expression, as well as its inhibitory effect on ferroptosis, but this effect was abrogated by NK-252. In vivo studies showed that knockdown of GOT1 expression inhibited tumor formation compared with tumor tissues formed upon exosome induction, which was mediated by promoting ferroptosis via suppressing the protein expression of GOT1, CCR2, Nrf2 and HO-1 in tumor tissues.

To some extent, the photosynthetic traits of developing leaves of maize are regulated systemically by water and nitrogen. However, it remains unclear whether photosynthesis is systematically regulated via water and nitrogen when maize crops are grown under close (high density) planting conditions. To address this, a field experiment that had a split-split plot arrangement of treatments was designed. Two irrigation levels on local traditional irrigation level (high, I2, 4,050 m3 ha−1) and reduced by 20% (low, I1, 3,240 m3 ha−1) formed the main plots; two levels of nitrogen fertilizer at a local traditional nitrogen level (high, N2, 360 kg ha−1) and reduced by 25% (low, N1, 270 kg ha−1) formed the split plots; three planting densities of low (D1, 7.5 plants m−2), medium (D2, 9.75 plants m−2), and high (D3, 12 plants m−2) formed the split-split plots. The grain yield, gas exchange, and chlorophyll a fluorescence of the closely planted maize crops were assessed. The results showed that water–nitrogen coupling regulated their net photosynthetic rate (Pn), stomatal conductance (Gs), transpiration rate (Tr), quantum yield of non-regulated non-photochemical energy loss [Y(NO)], actual photochemical efficiency of PSII [Y(II)], and quantum yield of regulated non-photochemical energy loss [Y(NPQ)]. When maize plants were grown at low irrigation with traditional nitrogen and at a medium density (i.e., I1N2D2), they had Pn, Gs, and Tr higher than those of grown under traditional treatment conditions (i.e., I2N2D1). Moreover, the increased photosynthesis in the leaves of maize in the I1N2D2 treatment was mainly caused by decreased Y(NO), and increased Y(II) and Y(NPQ). The coupling of 20%-reduced irrigation with the traditional nitrogen application boosted the grain yield of medium density-planted maize, whose Pn, Gs, Tr, Y(II), and Y(NPQ) were enhanced, and its Y(NO) was reduced. Redundancy analysis revealed that both Y(II) and SPAD were the most important physiological factors affecting maize yield performance, followed by Y(NPQ) and NPQ. Using the 20% reduction in irrigation and traditional nitrogen application at a medium density of planting (I1N2D2) could thus be considered as feasible management practices, which could provide technical guidance for further exploring high yields of closely planted maize plants in arid irrigation regions.

Cancer is a leading cause of death in worldwide. Growing evidence has shown that docosahexaenoic acid (DHA) has ameliorative effects on cancer. However, the effects of DHA-enriched phosphatidylcholine (DHA-PC) and efficacy differences between DHA-PC, DHA-triglyceride (DHA-TG), and DHA- ethyl esters (DHA-EE) on cancer cells had not been studied. In this study, 95D lung cancer cells in vitro were used to determine the effects and underlying mechanisms of DHA with different molecular forms. The results showed that DHA-PC and DHA-TG treatment significantly inhibited the growth of 95D cells by 53.7% and 33.8%, whereas DHA-EE had no significantly effect. Morphological analysis showed that DHA-PC and DHA-TG prompted promoted cell contraction, increased concentration of cell heterochromatin, vacuolization of cytoplasm, and edema of endoplasmic reticulum and mitochondria. TUNEL and AO/EB staining indicated that both DHA-PC and DHA-TG promoted cell apoptosis, in which DHA-PC performed better than DHA-TG. Mechanistically, DHA-PC and DHA-TG treatment up-regulated the PPARγ and RXRα signal, inhibited the expression of NF-κB and Bcl-2, and enhanced the expression of Bax and caspase-3, thereby promoting cell apoptosis. In conclusion, DHA-PC exerted superior effects to DHA-TG and DHA-EE in promoting apoptosis in 95D non-small-cell lung cancer cells. These data provide new evidence for the application of DHA in treatment of cancer.

The present study aimed to investigate the effect of resveratrol on inflammatory pain. Mice were injected intraperitoneally with lipopolysaccharide (LPS) for 5 consecutive days to induce subacute systemic inflammation. Acetic acid-induced writhing tests and tail-flick tests were performed following the final LPS injection. Glial fibrillary acidic protein (GFAP; an astrocyte-specific activation marker), ionized calcium binding adapter molecule 1 (Iba-1; a microglia-specific activation marker) and sirtuin 1 (SIRT1) protein expression levels were detected using immunohistochemistry analysis or western blotting. Following administration of LPS for 5 days, the number of writhes increased and the tail-flick latency decreased. Resveratrol (10 or 20 mg/kg) partly inhibited LPS-induced hyperalgesia and prevented the increase in tumor necrosis factor-a and interleukin 6 levels induced by LPS. LPS injection reduced the SIRT1 protein expression and increased the number of GFAP-positive and Iba-1-positive cells in the spinal cord. Resveratrol increased the SIRT1 protein expression levels and decreased the number of GFAP-positive and Iba-1-positive cells in LPS-treated mice. The protective effect of resveratrol was partly blocked by a selective SIRT1 inhibitor, EX-257. Results from the present study suggest that subacute treatment with LPS induced the activation of glial cells and hyperalgesia. Resveratrol was demonstrated to inhibit the activation of glial cells and attenuate inflammatory hyperalgesia in a SIRT1-dependent manner. [ABSTRACT FROM AUTHOR]

For advanced lung adenocarcinoma patients with common epidermal growth factor receptor (EGFR) mutations (exon 19 deletions or the exon 21 L858R mutation), tyrosine kinase inhibitors (TKIs) are the standard therapies, and achieve favorable responses. However, for the rare EGFR deletion-insertion mutation of exon 18, there is no evidence of the efficacy of EGFR TKIs. Herein, we report a lung adenocarcinoma patient harboring a rare EGFR E709_T710delinsD mutation who was treated with afatinib as the first-line therapy and achieved a progression-free survival of 23 months. After the disease progressed, the patient received almonertinib treatment and exhibited a stable disease. This case indicated that non-small cell lung cancer patients harboring the EGFR E709_T710delinsD mutation could benefit from afatinib treatment, followed with almonertinib treatment, as a potential therapeutic strategy.

Receptor tyrosine kinase ROR1 plays an essential role in embryogenesis and is overexpressed in many types of malignant tumors. Studies have demonstrated that it plays an important role in oncogenesis by activating cell survival signaling events, particularly the non-canonical WNT signaling pathway. Antibody-based immunotherapies targeting ROR1 have been developed and evaluated in preclinical and clinical studies with promising outcomes. However, small molecule inhibitors targeting ROR1 are underappreciated because of the initial characterization of ROR1 as a peusdokinase. The function of ROR1 as a tyrosine kinase remains poorly understood, although accumulating evidence have demonstrated its intrinsic tyrosine kinase activity. In this review, we analyzed the structural and functional features of ROR1 and discussed therapeutic strategies targeting this kinase.

Plastic is a valuable mulching measure for increasing crop productivity in arid environments; however, little is known about the main mechanism by which this valuable technology actuates spatial–temporal changes in soil hydrothermal effect. So a 3-year field experiment was conducted to optimize soil hydrothermal effect of maize field with three plastic mulched management treatments: (1) no tillage with plastic re-mulching (NM), (2) reduced tillage with plastic mulching (RM), and (3) conventional tillage with annual new plastic mulching (CM). The results showed that NM treatment increased soil water content by 6.6–8.4% from maize sowing to seedling stage, than did CM, and it created a good soil moisture environment for sowing of maize. Also, NM had greater soil water content by 4.8–5.6% from maize silking to early-filling stage than had CM, and it made up for the abundant demand of soil moisture for the vigorous growth of maize filling stage. The NM treatment increased water consumption (WC) before maize big-flare stage, decreased WC from big-flare to early-filling stage, and increased WC after early-filling stage. So NM treatment effectively coordinated water demand contradiction of maize at entire growing season. NM decreased soil accumulated temperature (SAT) by 7.0–13.0% at maize sowing to early-filling stage than did CM, but NM had little influence on the SAT during filling stage. In particular, the treatment on NM had smaller absolute values of air–soil temperature differences than RM and CM treatments during maize filling stage, indicating that NM treatment maintains the relative stability of soil temperature for ensuring grain filling of maize. The NM treatment allowed the maize to grow in a suitable hydrothermal status and still maintained high yield. In addition, NM treatment obtained higher net income and rate of return by 6.4–11.0% and 44.1–54.5%, respectively, than did CM, because NM treatment mainly decreased the input costs for plastic and machine operations. Therefore, the NM treatment can be recommended as a promising technique to overcome simultaneous heat stress and water shortage in arid environments.

In order to improve cold roll-beating forming spline surface roughness and surface quality,cold roll-beating experiment is carried out. According to cold roll-beating spline forming principle,the main influencing factors（ rolling wheel speed,workpiece feed rate,beating ways,beating depth） of the surface roughness of cold roll forming spline are analyzed. The relationship between the rotational speed of the rolling wheel,workpiece feed rate and the surface roughness is quantitatively analyzed. Research shows: The surface roughness with the increase in the rotation speed of the wheel shows a downward trend.And the surface roughness increases with the increase of workpiece feed rate. When the rotational speed of the rolling wheel is in the range of 1581 r/min ～ 2032 r/min and the workpiece feed rate is in the range of 21 mm/min ～ 35 mm/min,the suitable cold roll-beating spline surface roughness and considerable surface quality is obtained.

Recently, tin oxide (SnO2) has been the preferred thin film material for semiconductor devices such as thin-film transistors (TFTs) due to its low cost, non-toxicity, and superior electrical performance. However, the high oxygen vacancy (VO) concentration leads to poor performance of SnO2 thin films and devices. In this paper, with tetraethyl orthosilicate (TEOS) as the Si source, which can decompose to release heat and supply energy when annealing, Si doped SnO2 (STO) films and inverted staggered STO TFTs were successfully fabricated by a solution method. An XPS analysis showed that Si doping can effectively inhibit the formation of VO, thus reducing the carrier concentration and improving the quality of SnO2 films. In addition, the heat released from TEOS can modestly lower the preparation temperature of STO films. By optimizing the annealing temperature and Si doping content, 350 °C annealed STO TFTs with 5 at.% Si exhibited the best device performance: Ioff was as low as 10−10 A, Ion/Ioff reached a magnitude of 104, and Von was 1.51 V. Utilizing TEOS as an Si source has a certain reference significance for solution-processed metal oxide thin films in the future.

Cables/hangers are important load-bearing components of suspension, cable-stayed, and through-arch bridges. Their reliability throughout their service life directly affects the safety of these bridges. In this study, to provide a reference for the design, maintenance, and inspection of bridge cables/hangers, their damage and failure mechanisms were theoretically analyzed using finite element analysis and corrosion-fatigue simulation tests of steel wires, based on the characteristics of the cable/hanger damage. The finite element analysis showed that a rotation of 0.00113 rad in the lower anchorage area results in a bending stress of 18.8 MPa, indicating that the effect of the bending stress on the steel wires in this area cannot be neglected, as it is a factor contributing to the failure of long cables/hangers. We further used a salt spray chamber to simulate an acid-rain environment. The results showed the following: (1) corrosion-fatigue damage of the cables/hangers occurs under the combined action of a corrosive environment and an alternating stress. This leads to an intensified corrosion damage, reduced ductility, increased brittleness, and eventually, brittle fracturing of the cables/hangers. (2) In the same corrosive environment, the highest degree of specimen corrosion occurred during alternating stress, followed by static stress, and no stress. (3) After corrosion-fatigue damage occurred for a specimen, its breaking stress was about 60% in comparison to the uncorroded specimen. The percentage elongation at the break also decreased; this was about 40% in comparison to the uncorroded specimen, indicating brittle fracturing. (4) The steel wires of the cables/hangers with corrosion-fatigue damage are more prone to brittle fracture if they are exposed to complex spatial stresses.

Accumulating evidence suggests that activation of spinal microglia contributes to the development of inflammatory and neuropathic pain. However, the role of spinal microglia in the maintenance of chronic pain remains controversial. Bone cancer pain shares features of inflammatory and neuropathic pain, but the temporal activation of microglia and astrocytes in this model is not well defined. Here, we report an unconventional role of spinal microglia in the maintenance of advanced-phase bone cancer pain in a female rat model. Bone cancer elicited delayed and persistent microglial activation in the spinal dorsal horn on days 14 and 21, but not on day 7. In contrast, bone cancer induced rapid and persistent astrocytic activation on days 7-21. Spinal inhibition of microglia by minocycline at 14 d effectively reduced bone cancer-induced allodynia and hyperalgesia. However, pretreatment of minocycline in the first week did not affect the development of cancer pain. Bone cancer increased ATP levels in CSF, and upregulated P2X7 receptor, phosphorylated p38, and IL-18 in spinal microglia. Spinal inhibition of P2X7/p-38/IL-18 pathway reduced advanced-phase bone cancer pain and suppressed hyperactivity of spinal wide dynamic range (WDR) neurons. IL-18 induced allodynia and hyperalgesia after intrathecal injection, elicited mechanical hyperactivity of WDR neurons in vivo, and increased the frequency of mEPSCs in spinal lamina IIo nociceptive synapses in spinal cord slices. Together, our findings demonstrate a novel role of microglia in maintaining advanced phase cancer pain in females via producing the proinflammatory cytokine IL-18 to enhance synaptic transmission of spinal cord nociceptive neurons. [ABSTRACT FROM AUTHOR]

Background: Systemically administered dexmedetomidine (DEX), a selective α2 adrenergic receptor (α2-AR) agonists, produces analgesia and sedation. Peripherally restricted α2-AR antagonist could block the analgesic effect of systemic DEX on neuropathic pain, with no effect on sedation, indicating peripheral analgesic effect of DEX. Tetrodotoxinresistant (TTX-R) sodium channel Nav1.8 play important roles in the conduction of nociceptive sensation. Both α2-AR and Nav1.8 are found in small nociceptive DRG neurons. We, therefore, investigated the effects of DEX on the Nav1.8 currents in acutely dissociated small-diameter DRG neurons. Results: Whole-cell patch-clamp recordings demonstrated that DEX concentration-dependently suppressed TTX-R Nav1.8 currents in small-diameter lumbar DRG neurons. DEX also shifted the steady-state inactivation curves of Nav1.8 in a hyperpolarizing direction and increased the threshold of action potential and decrease electrical and chemical stimuli-evoked firings in small-diameter DRG neurons. The α2-AR antagonist yohimbine or α2A-AR antagonist BRL44408 but not α2B-AR antagonist imiloxan blocked the inhibition of Nav1.8 currents by DEX. Immunohistochemistry results showed that Nav1.8 was predominantly expressed in peripherin-positive small-diameter DRG neurons, and some of them were α2A-AR-positive ones. Our electrophysiological recordings also demonstrated that DEX-induced inhibition of Nav1.8 currents was prevented by intracellular application of G-protein inhibitor GDPβ-s or Gi/o proteins inhibitor pertussis toxin (PTX), and bath application of adenylate cyclase (AC) activator forskolin or membrane-permeable cAMP analogue 8-Bromo-cAMP (8-Br-cAMP). PKA inhibitor Rp-cAMP could mimic DEX-induced inhibition of Nav1.8 currents. Conclusions: We established a functional link between α2-AR and Nav1.8 in primary sensory neurons utilizing the Gi/o/AC/cAMP/PKA pathway, which probably mediating peripheral analgesia of DEX. [ABSTRACT FROM AUTHOR]

Chronic stress represents a vulnerability factor for anxiety and depressive disorders and has been widely used to model aspects of these disorders in rodents. Disinhibition of somatostatin (SST)-positive GABAergic interneurons in mice by deletion of γ2 GABAA receptors selectively from these cells (SSTCre:γ2f/f mice) has been shown to result in behavioral and biochemical changes that mimic the responses to antidepressant doses of ketamine. Here we explored the extent to which SSTCre:γ2f/f mice exhibit resilience to unpredictable chronic mild stress (UCMS). We found that male SSTCre:γ2f/f mice are resilient to UCMS-induced (i) reductions in weight gain, (ii) reductions in SST-immuno-positive cells in medial prefrontal cortex (mPFC), (iii) increases in phosphorylation of eukaryotic elongation factor 2 (eEF2) in mPFC, and (iv) increased anxiety in a novelty suppressed feeding test. Female SSTCre:γ2f/f mice were resilient to UCMS-induced reductions in SST-immuno-positive cells indistinguishably from males. However, in contrast to males, they showed no UCMS effects on weight gain independent of genotype. Moreover, in mPFC of female γ2f/f control mice, UCMS resulted in paradoxically reduced p-EF2 levels without stress effects in the SSTCre:γ2f/f mutants. Lastly, female SSTCre:γ2f/f mice showed increased rather than reduced UCMS induced anxiety compared to γ2f/f controls. Thus, disinhibition of SST interneurons results in behavioral resilience to UCMS selectively in male mice, along with cellular resilience of SST neurons to UCMS independent of sex. Thus, mechanisms underlying vulnerability and resilience to stress are sex specific and map to mPFC rather than hippocampus but appear unrelated to changes in expression of SST as a marker of corresponding interneurons.

The design of a modern Global Navigation Satellite System (GNSS) has been exceptionally valued by the military and civilians of various countries. The inclusion of the pilot channel in addition to the navigation data channel is considered one of the major changes in GNSS modernization. Schemes of an equal weight combination (1:1 combination) and power ratio combination for data and pilot are primarily adopted by traditional receivers. With the emergence of the new data and pilot modulation signals with unequal power, such as L1C at Global Positioning System (GPS) L1 frequency and B1C at BeiDou Navigation Satellite System (BDS) B1 frequency, the traditional combination coefficient cannot achieve optimal reception performance. Considering the influence of the combination coefficient on the reception performance, the optimal coefficient of the correlator joint is estimated in this paper. The entire architecture of the data/pilot correlator joint tracking and positioning with unequal power is given. Based on the equivalence principle of the correlator joint and the discriminator joint, the optimal coefficient of the carrier loop is determined. A mathematical model of joint code tracking accuracy is established, and the optimal coefficient of the code loop is determined. The real-life satellite signal and simulation results show that the amplitude–ratio combined scheme is the best for receiving of correlator joints, followed by the power–ratio combination scheme and, finally, the 1:1 combination scheme. It is worth mentioning that the positioning accuracy of the amplitude–ratio combination is improved by 2% compared to the 1:1 combination, and by 1.3% compared to the power–ratio combination for B1C signal. The positioning accuracy of the amplitude–ratio combination is improved by 2.37% compared to the 1:1 combination, and by 1.6% compared to the power–ratio combination for L1C signal. The conclusions of this paper are validated for the traditional data/pilot with an equal power allocation. The techniques and test results provide technical support for GNSS high-precision-user receivers.

In the field of oil and gas exploration, drilling fluid is regarded as the essential “blood” for drilling, which mainly helps to control the formation pressure and remove cuttings from the well. During the drilling fluid cycle, the drilling fluid penetrates into the pores of the formation rock, thus blocking the rock pores and resulting in a decline in oil and gas recovery efficiency. Therefore, it is very important to understand the microscopic mechanism of formation damage caused by drilling fluid. However, as an important component of formation damage, the microscopic mechanism of fluid damage has not yet been clearly revealed. In this study, a new microetching model (MEM), along with displacement equipment, was designed. The pore network of rock samples was extracted from thin-section images and etched to a thin aluminum sheet by laser. Oil-based drilling fluid was used to displace the stratum water in the MEM. The displacement process was recorded by a camera and analyzed. A core flooding experiment, permeability measurement, and SEM observations were performed. The results show that, for low-porosity and low-permeability sandstone, the main forms of formation damage by drilling fluid include solid damage and liquid damage. Solid damage is mainly caused by the blockage of small pores and narrow throats with solid particles of the size 0.1~30.0 μm in drilling fluid, while liquid damage is mainly caused by the water lock and hydrocarbon lock effects formed by the oil–water two-phase interface, gas–water two-phase interface, or the oil–gas–water three-phase interface.

Pain is the most common symptom of bone cancer. TGF-ß, a major bone-derived growth factor, is largely released by osteoclast bone resorption during the progression of bone cancer and contributes to proliferation, angiogenesis, immunosuppression, invasion, and metastasis. Here, we further show that TGF-ß 1 is critical for bone cancer-induced pain sensitization. We found that, after the progression of bone cancer, TGF-ß1 was highly expressed in tumor-bearing bone, and the expression of its receptors, TGFßRI and TGFßRII, was significantly increased in the DRG in a rat model of bone cancer pain that is based on intratibia inoculation of Walker 256 mammary gland carcinoma cells. The blockade of TGF-ß receptors by the TGFßRI antagonist SD-208 robustly suppressed bone cancer-induced thermal hyperalgesia on post-tumor day 14 (PTD 14). Peripheral injection ofTGF-ß1 directly induced thermal hyperalgesia in intact rats and wide-type mice, but not in Trpvl-/- mice. Whole-cell patch-clamp recordings from DRG neurons showed that transient receptor potential vanilloid (TRPV1) sensitivity was significantly enhanced on PTD 14. Extracellular application ofTGF-ß1 significantly potentiated TRPV1 currents and increased [Ca2+]i in DRG neurons. Pharmacological studies revealed that the TGF-ß1 sensitization of TRPV1 and the induction of thermal hyperalgesia required the TGF-ßR-mediated Smad-independent PKCe and TGF-ß activating kinase 1-p38 pathways. These findings suggest that TGF-ß1 signaling contributes to bone cancer pain via the upregulation and sensitization of TRPV1 in primary sensory neurons and that therapeutic targeting ofTGF-ß1 may ameliorate the bone cancer pain in advanced cancer. [ABSTRACT FROM AUTHOR]

Taking the non-road turbocharged inter-cooled diesel engine for research objects, by means of coupled fluid-solid analysis method, established the coupled heat transfer model of Cylinder head-Cooling fluid-Cylinder liner-Cylinder block,did a temperature test of flame face of cylinder head and key points of cylinder liner, studied the deformation of cylinder liner under the mechanical loads、thermal loads and coupled loads. The result show that temperature distribution of cylinder liner is not uniform, the highest temperature located in the top of the first cylinder liner; The deformation is relatively small under mechanical loads and the maximum value appeared in the thrust side of the top of the forth cylinder liner; The deformation is heart-shaped under coupled loads, the maximum value appeared in the top of the forth cylinder liner and close to the direction of flywheel, the thermal loads are predominant.

Motion trajectories tracked from the points of interest can provide the key relevant features for characterizing the motion patterns in video. As the increasing number of 3-D vision sensors rises, the 3-D motion trajectories that serve as motion representations have been applied successfully to video retrieval and analysis, scene understanding, motion recognition, and so on, in existing works. Most of these works use raw data of motion trajectories directly or draw simple geometric quantities to describe the motion trajectories, whereas these simple descriptions are not intrinsically complete as they cannot feature the orientation changes of moving points along the 3-D motion trajectories. In principle, orientation changes of a single moving point in 3-D space have to been obtained by resorting to high-order derivatives, but the high-order derivatives would result in high sensitivity to noise. This paper tackles the problem by describing the local reference frames along 3-D motion trajectories, while we consider a motion trajectory as a temporal sequence of local reference frames. The maximal blurred segment of the noisy discrete curves is employed to estimate the local reference frames without high-order derivatives involved, and the local reference frame contains complete information of positions and orientations in the 3-D Euclidean space. To describe such local reference frames, we use the rotations and local square root velocities of local reference frames as the proposed descriptor to characterize the position and orientation changes of the moving points along the motion trajectories. In the experiments, we evaluate the effectiveness of the proposed descriptor by applying it to the gesture recognition on two large benchmark data sets that contain hand motion trajectories. The results show that our proposed descriptor can achieve superior performance compared to the existing descriptors and state-of-the-art methods in the 3-D motion trajectory recognition.

A microstrip patch antenna (MPA) loaded with linear-type negative permittivity metamaterials (NPMMs) is designed. The simple linear-type metamaterials have negative permittivity at 1–10 GHz. Four groups of antennas at different frequency bands are simulated in order to study the effect of linear-type NPMMs on MPA. The antennas working at 5.0 GHz are processed and measured. The measured results illustrate that the gain is enhanced by 2.12 dB, the H-plane half-power beam width (HPBW) is converged by 14°, and the effective area is increased by 62.5%. It can be concluded from the simulation and measurements that the linear-type metamaterials loaded on the substrate of MAP can suppress surface waves and increase forward radiation well.

Current generation of smartphones is running more and more complex applications that reduce the battery life to as short as several hours. Thus, it becomes very important to understand the diversities of applications installed on smartphones and how batteries are consumed across different applications. This paper presents a large-scale battery study on smartphones focusing on diversities in applications and users. Based on application and battery traces collected on over 80000 Android smartphones for a four-week period, we analyze the battery discharging patterns, the types of mobile applications, and the usage and energy consumption patterns for these applications. During the analysis, we introduce a novel method to calculate the energy consumption rate for each application based on coarse-grained battery data collected with a lightweight monitoring tool. Based on the results, we present some observations and discuss possible improvements on smartphone designs and mobile application development. We also compare our results to some previous studies wherever it is possible.

Intercropping is considered a promising system for boosting crop productivity. However, intercropping usually requires higher inputs of resources that emit more CO2. It is unclear whether an improved agricultural pattern could relieve this issue and enhance agricultural sustainability in an arid irrigation area. A field experiment using a well-designed agricultural practice was carried out in northwest China; reduced tillage, coupled with wheat straw residue retention measures, was integrated with a strip intercropping pattern. We determined the crop productivity, water use, economic benefits, and carbon emissions (CEs). The wheat-maize intercropping coupled with straw covering (i.e., NTSI treatment), boosted grain yield by 27–38% and 153–160% more than the conventional monoculture of maize and wheat, respectively, and it also increased by 9.9–11.9% over the conventional intercropping treatment. Similarly, this pattern also improved the water use efficiency by 15.4–22.4% in comparison with the conventional monoculture of maize by 45.7–48.3% in comparison with the conventional monoculture of wheat and by 14.7–15.9% in comparison with the conventional intercropping treatment. Meanwhile, NTSI treatment caused 7.4–13.7% and 37.0–47.7% greater solar energy use efficiency than the conventional monoculture of maize and wheat, respectively. Furthermore, the NTSI treatment had a higher net return (NR) by 54–71% and 281–338% and a higher benefit per cubic meter of water (BPW) by 35–51% and 119–147% more than the conventional monoculture of maize and wheat, respectively. Similarly, it increased the NR and BPW by 8–14% and 14–16% in comparison with the conventional intercropping treatment, respectively. An additional feature of the NTSI treatment is that it reduced CEs by 13.4–23.8% and 7.3–17.5% while improving CE efficiency by 62.6–66.9% and 23.2–33.2% more than the conventional monoculture maize and intercropping treatments, respectively. We can draw a conclusion that intercropping maize and wheat, with a straw covering soil surface, can be used to enhance crop production and NRs while effectively lowering CO2 emissions in arid oasis irrigation region.

The effect of different cross-fostering strategies on the growth performance, stress and immunity of piglets was investigated in this study. In the first experiment, a total of 20 litters (i.e., 20 sows) and 120 piglets were classified into one of six treatments in a 2 × 3 factorial arrangement. The treatments consisted of piglets without or with cross-fostering and different birth weights (low birth weight, LBW; intermediate birth weight, IBW; high birth weight, HBW). The weaning weight (WW) and average daily gain (ADG) of LBW piglets and IBW piglets were not significantly different between the not cross-fostered (NC-F) group and the cross-fostered (C-F) group. There was a higher (p < 0.05) ADG in the control piglets compared with the cross-fostered piglets. This effect on ADG was only seen in the HBW piglets. In the second experiment, six sows with a similar body condition and farrowed on the same day were selected. Three female piglets with a birth weight of 0.6–0.85 kg were selected from each litter as experimental piglets. Eighteen piglets were grouped into three treatments: (1) not cross-fostered (NC-F1), (2) cross-fostered at 36–48 h after birth (C-F1), (3) cross-fostered at day 7 after birth (C-F2). The growth performance of NC-F1 and C-F1 piglets was higher than C-F2 piglets (p < 0.05), and the suckling positions of NC-F1 and C-F1 piglets on days 8, 12, 16 and 20 were more forward than the C-F2 piglets (p < 0.05). Plasma cortisol (COR) concentrations of NC-F1 and C-F1 piglets were lower than C-F2 piglets (p < 0.05). A significant negative correlation was observed between BW at day 21 and plasma COR concentration. In conclusion, cross-fostering within 24 h of birth has adverse influences on the ADG of HBW piglets, while it has no negative effect on the ADG of LBW and IBW piglets. Moreover, for IBW piglets, late cross-fostering (i.e., on day 7 after farrowing) has negative impacts on the growth performance and teat order of piglets, and it increases the cortisol level of piglets.

In an attempt to investigate the nature and origin of mantle heterogeneities beneath the South Mid-Atlantic Ridge (SMAR), we report new whole-rock Sr, Nd, Pb, and Hf isotopic data from eight basalt samples at four dredge stations along the SMAR between 18°S and 21°S. Sr, Nd, and Pb isotopic data from SMAR mid-ocean ridge basalts (MORBs) at 18–21°S published by other researchers were also utilized in this study. The SMAR MORBs at 18–21°S feature the following ratio ranges: 87Sr/86Sr = 0.70212 to 0.70410, 143Nd/144Nd = 0.512893 to 0.513177, 206Pb/204Pb = 18.05 to 19.50, 207Pb/204Pb = 15.47 to 15.71, 208Pb/204Pb = 37.87 to 38.64, and 176Hf/177Hf = 0.283001 to 0.283175. The 87Sr/86Sr, 143Nd/144Nd, 206Pb/204Pb, and 176Hf/177Hf ratios of these MORBs varied considerably along the SMAR axis. The variable compositions of the Sr–Nd–Pb–Hf isotopes, combined with the corresponding whole-rock major and trace elemental abundances reported in previous studies, suggest that the SMAR MORBs at 18–21°S were probably derived from a heterogeneous mantle substrate related to a mixture of depleted mantle (DM) materials with a small amount (but variable input) of HIMU (high-μ, where μ = 238U/204Pb)- and enriched (EMII)-type materials. The HIMU-type materials likely originated from the proximal St. Helena plume and may have been transported through “pipe-like inclined sublithospheric channels” into the SMAR axial zone. The EMII-type materials possibly originated from a recycled metasomatized oceanic crust that may have been derived from the early dispersion of other plume heads into the subcontinental asthenosphere prior to the opening of the South Atlantic Ocean. In addition, the contributions of subducted sediments, continental crust, and subcontinental lithospheric mantle components to the formation of the SMAR MORBs at 18–21°S may be nonexistent or negligible.

In this paper, isoelectronic doping with indium (In) in p-GaN is investigated on the basis of the thermal quenching of ultraviolet luminescence (UVL) band. A phenomenological rate-equation model is proposed as a nondestructive diagnostic technique to acquire the dopant ionization energy of p-GaN. In terms of this model, we analyze the evolution of the ionization energy of p-GaN samples grown with different trimethyindium flow rate and find that isoelectronic doping with appropriate In incorporation is able to significantly reduce the ionization energy of the acceptor from 245 to 112 meV, which are consistent with the results of the variable temperature Hall-effect measurements. The comparison between the samples' full width at half maximum of the UVL band indicates that excessive In incorporation will degenerate the conductivity of p-GaN.

Trillions of bacteria reside in the human gut and they metabolize dietary substances to obtain nutrients and energy while producing metabolites. Therefore, different dietary components could affect human health in various ways through microbial metabolism. Many such metabolites have been shown to affect human physiological activities, including short-chain fatty acids metabolized from carbohydrates; indole, kynurenic acid and para-cresol, metabolized from amino acids; conjugated linoleic acid and linoleic acid, metabolized from lipids. Here, we review the features of these metabolites and summarize the possible molecular mechanisms of their metabolisms by gut microbiota. We discuss the potential roles of these metabolites in health and diseases, and the interactions between host metabolism and the gut microbiota. We also show some of the major dietary patterns around the world and hope this review can provide insights into our eating habits and improve consumers’ health conditions.

The article comes up with a measure that uses fiber vibration sensing technology to avoid external intrusion harm on electric cables, dealing with the problem that buried cables are sometimes destroyed by constructions. This measure is based on dual Mach-Zehnder(M-Z) interference, and it makes use of power grids’ fiber-optic cables laid in the cable trench—along with the electric cables—as sensors. These sensors could monitor vibration near to optical cables and trench, and recognize the events that vibrate the cable, and finally judge the extent of the harm caused by the events. The article also try to find out a more reliable and more efficient mechanism of patrolling electric cables, which is based on the abovementioned measure.

In this paper, the adsorption and anoxic degradation of No. 0 diesel oil in Bohai coastal sediments were studied. The results showed that the adsorption of oil on the coastal sediments matched pseudo-second-order kinetics, which indicated that adsorption processes were essentially chemical reactions. Part of oil could be degraded in natural coastal sedimentary environment, and the additions of nutrients and proper electron acceptors could promote the degradation of oil effectively. The addition of nitrogen and phosphorus nutrients increased the removal ratio of oil from 54 % to 61 %. Different electron acceptors showed different effects on the degradation of oil in coastal sediment. Nitrate greatly promoted the degradation of oil, but sulfate had an adverse effect on that. Three oil-degrading strains named B1, B2, B3 were domesticated and isolated from Bohai coastal sediments. All the three strains could promote the degradation of oil, and the effect of B2 on the degradation of oil was the most significant, which increased the removal ratio of oil by nearly 30 %.

This paper aims to disclose the adsorption and anoxic degradation processes of three typical polycyclic aromatic hydrocarbons (PAHs) in the coastal sediments of China’s Bohai Sea region. The PAHs are naphthalene (Nap), phenanthrene (Phe) and pyrene (Pyr). Several sediments samples were collected from Qinhuangdao Port, and subjected to adsorption and biodegradation experiments. Then, pseudo-first-order and pseudo-second-order kinetic models were tested to explain the kinetics of liquid-solid phase adsorption systems. It is discovered that the adsorption of the three PAHs on the coastal sediments matched pseudo- second-order kinetics, revealing that adsorption processes were essentially chemical reactions. In terms of equilibrium adsorption capacity, the three PAHs are ranked as Pyr>Phe>Nap. Next, Freundlich and Langmuir models were employed to fit the experimental data. The fitting results show that the adsorption of Nap, Phe and Pyr on the coastal sediments can be explained as mono-molecular layer adsorption. All the adsorptions of Nap, Phe and Pyr were exothermic reactions. In the anoxic sediments, 93.2% of Nap was removed after 30h, 96.6% of Phe was removed after 7d, and 98.1% of Pyr was removed after 42d. The detected metabolites of Nap were [4,4-dimethyl-2-cyclohexene-1-ol], [1-carboxyl,2-hydroxy, 4-methyl-cyclohexane], the metabolites of Phe were [3-ethoxy ethyl benzoate], [Phthalate (2-methyl propyl) ester] and the metabolites of Pyr were [2- methyl succinic acid, double (2-methyl propyl) ester], [Phthalate (2-methyl propyl) ester], [Phthalic acid butyl ester, 14 alkyl ester]. The findings shed new light on the research of PAHs adsorption and anoxic degradation in coastal sediments.

In this work, the corrosion behaviors of steel strands exposed to acidic rain under alternating stress, static stress, and no stress were modeled based on experimental data. The results are based on an image corrosion feature analysis of steel strands at different corrosion times and operating conditions, and the corrosion fatigue behaviors indicate that the steel strands display different degrees of corrosion under different loading conditions. The corrosion fatigue behaviors of the steel strands were analyzed based on the corrosion features in the images of the steel strands subjected to different corrosion times and operating conditions. The results showed that different loading conditions lead to different degrees of corrosion in the steel strands. The samples’ surface images and corrosion damage continuously changed as the corrosion time increased. Given the same corrosion time, the degree of corrosion was the highest in samples subjected to alternating stress, followed by that in samples under static stress. Unstressed samples had the lowest degree of corrosion. The variations of the corroded surface and the degree of corrosion in the material were particularly reflected by three image features pitting rate, pit depth, and pit radius. No significant changes occurred in the samples when the corrosion time was 120–360 h, regardless of the type of stress they were subjected to. This finding indicated that pitting has a minimal effect on the force-bearing capacity of steel strands during pit nucleation and expansion. However, a substantial decrease in the fracture strength occurred under alternating stresses when the pits expanded into cracks (very deep cracks were found at the 720-h mark in the samples subjected to alternating loads). Conventional damage tolerance analysis methods and software can then be used to perform crack propagation life predictions by treating pits as quantizations of a crack. Fatigue life estimation based on the corrosion images with the appropriate combination of corrosion damage levels and load-bearing capacities is a viable technical pathway. The findings of this work will provide new ideas for the assessment of structural reliability and safety via the processing of inspection photographs.

At present, the qualities of the coastal aquatic ecosystems and sediments have seriously deteriorated as a result of excessive using the pyrethroid insecticides in the tidal farms. Deltamethrin is one of the most frequently detected pyrethroid in the coastal sediment. In this paper, the anoxic degradation behavior and mechanism of deltamethrin in bohai coastal sediment was studied. The results showed that deltamethrin could be degraded in natural coastal sedimentary environment at a relatively slow rate. The degradation kinetics followed the first-order kinetic with the rate constant 0.0055 h-1.The m-phenoxyphenyl-acetonitril was the main metabolic product, and the possible degradation pathway was that deltamethrin was hydrolyzed at ester bond firstly, and then was reduced to be m-phenoxyphenyl-acetonitril. Adequate addition of carbon sources could significantly promote the microbial degradation of deltamethrin, but oversupplying carbon source inhibited it.

Background: Hyperhomocysteinemia (HHcy) may be correlated with cognitive function. Although intervention with folic acid and VitBi2 can decrease the homocysteine (Hcy) level, its effect on cognitive function remains uncertain. This prospective study aimed to explore the effects of folic acid and VitBi2 on the Hcy level and cognitive function in patients with vascular cognitive impairment-no dementia (VCIND) complicated with HHcy. Methods: A total of 120 patients with VCIND complicated by HHcy were randomly selected. They were divided into intervention and control groups. The intervention group was given 5 mg of folic acid per day and 500 μg of VitB12 thrice per day apart from conventional therapy. Folic acid, VitB12, and Hcy were determined and Montreal cognitive assessment (MoCA) and event-related potential P300 determination were performed before and after treatment. Results: Before treatment, no significant differences in the folic acid, VitB12, Hcy, MoCA, and P300 parameters were observed between the groups. After treatment, the folic acid and VitB12 levels increased and the Hcy level decreased in the intervention group compared with that before treatment and in the control group. At 24 weeks, the MoCA score and P300 outcomes in the intervention group improved compared with those before treatment and in the control group. Conclusions: Folic acid and VitB12 effectively decrease the Hcy level in VCIND patients and improve their cognitive functions.

To evaluate the influence of transition metal substituents on the characteristics of CH3NH3PbI3/TiO2, we investigated the geometrical and electronic properties of transition metal-substituted CH3NH3PbI3/TiO2 by first-principles calculations. The results suggested that the substitution of Ti4+ at the five-fold coordinated (Ti5c) sites by transition metals is energetically favored. The substituted interface has enhanced visible light sensitivity and photoelectrocatalytic activity by reducing the transition energies. The transition metal substitution can effectively tune the band gap of the interface, which significantly improves the photo-reactivity. The substituted systems are expected to be more efficient in separating the photo-generated electrons-holes and active in the visible spectrum.

Accumulating evidence indicates that cold exposure changes the composition of the gut microbiota and reduces intestinal immunity in early postweaning livestock. However, little is known about the effects of drinking warm water (WW) on gut microbiota during winter. In this study, we investigated the effects of drinking WW in winter on the growth performance and gut microbiota structure of rabbits raised in poorly insulated housing from the early postweaning period (day 46) to the subadult period (day 82). The average daily gain and feed conversion ratio in rabbits drinking WW were significantly improved compared to those of the rabbits drinking cold water (CW) during 47−58 days. In addition, rabbits drinking WW had a significantly decreased the risk of diarrhea during 71−82 days. 16S rRNA sequence analysis revealed that the alpha diversity of the cecal microbiota was not significantly different between the WW and CW groups, but significantly increased with age. The relative abundance of cecal microorganisms, such as Coprococcus spp. was considerably increased at day 70 in the group drinking WW. Correlation analysis indicated that Coprococcus spp. was negatively associated with pro-inflammatory factors. In conclusion, our results suggest that drinking WW has a positive effect on growth performance and gut microbiota in rabbits during the early postweaning stage in winter.

The Yushui ore deposit, located in the middle section of the Yong’an-Meixian Hercynian depression, is a medium-sized Cu-polymetallic massive sulphide deposit in Eastern Guangdong Province, South China. This deposit is characterized by unusually high copper grade (up to 50−60 wt. % Cu). Other metallic elements, such as lead, zinc and silver, are also economically important in the Yushui ore bodies. The aim of this study was to apply N2−Ar−He systematics, together with organic gases (light-hydrocarbon tracers), to constrain the origin and evolution of ore-forming fluids. The helium-argon isotopes and trace gas compositions of fluid inclusions trapped within metal sulphide minerals were measured for a number of bonanza ores from the Yushui deposit. The noble gas concentrations in the studied samples vary over one to two orders of magnitude (4He: 2.27−160.00 × 10−5 cm3 STP g−1; 3He: 0.53−34.88 × 10−12 cm3 STP g−1; 40Ar: 6.28−37.82 × 10−7 cm3 STP g−1; 36Ar: 1.25−10.40 × 10−9 cm3 STP g−1). Our data show a narrow range of 3He/4He ratios from 0.006 to 0.056 Ra (~0.026 Ra on average, n = 8), which are considerably lower than the modern atmospheric end-member value; whereas the 40Ar/36Ar ratios (ranging from 333.76 to 501.68, with an average of 397.53) are significantly greater than that of air-saturated water. Most of the bornite samples have somewhat higher 3He/4He ratios of trapped fluids when compared to chalcopyrite. Overall, these He-Ar results are well within the range of crustal reservoir, thus implying a predominantly crustal source (originated from Caledonian basement) for ore-forming solutions, with little contribution from mantle-derived fluids. Analysis of the N2−Ar−He composition in Cu-rich sulphides indicates that the Yushui ore-forming fluids were probably derived from formation water (or basinal hot brines). Moreover, organic gas species identified in sulphide-hosted fluid inclusions are mainly composed of C1−C4 alkanes, while the concentrations of unsaturated olefins and aromatic hydrocarbons are very low. In particular, most chalcopyrite samples with relatively low 3He/4He ratios (0.006−0.016 Ra) and 40Ar*/4He values (0.0002−0.0012) are generally characterized by very high CO2/CH4 ratios (~60−102). All these suggest that main-stage Cu-Ag metallogenic processes might have not been affected by high-temperature magmatic activities or superimposed by strong metamorphic overprinting, although some chalcopyrite-rich ores appear to be influenced by later stage hydrothermal processes. In summary, neither magmatic input nor convecting seawater has played an important role in the formation of Yushui copper-polymetallic deposit. The massive sulphide ore bodies were products of water−rock interaction between metal-bearing basinal brines and the host sedimentary strata.

Marine hydrogenetic Fe–Mn crusts on seamounts are known as potential mineral resources of rare earth elements plus yttrium (REY). In recent years, increasing numbers of deposits of Fe–Mn crusts and nodules were discovered in the South China Sea (SCS), yet the enrichment mechanism of REY is yet to be sufficiently addressed. In this study, hydrogenetic Fe–Mn crusts from the South China Sea (SCS) and the Western Pacific Ocean (WPO) were comparatively studied with mineralogy and geochemistry. In addition, we used an in situ REY distribution mapping method, implementing laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) and a sequential leaching procedure to investigate the partitioning behavior of REY in the Fe–Mn crusts. The typical Fe–Mn crusts from SCS were mainly composed of quartz, calcite, vernadite (δ-MnO2), and amorphous Fe oxides/hydroxides (FeOOH). The Fe–Mn crusts from the Central SCS Basin and the WPO contained quartz, δ-MnO2, FeOOH, todorokite, and phillipsite. Furthermore, geochemical analysis indicated that the typical SCS crusts had a higher growth rate and lower REY concentrations. The LA-ICP-MS mapping results showed that the δ-MnO2 and FeOOH dominated the occurrence phases of REY in the SCS crusts. Four mineral phases (i.e., easily exchangeable and carbonate, Mn-oxide, amorphous FeOOH, and residual aluminosilicates) in these Fe–Mn crusts were separated by a sequential leaching procedure. In the SCS and WPO crusts, the majority of total REY (ΣREY) was distributed in the Mn-oxide and amorphous FeOOH phases. The post-Archean Australian shale-normalized REY patterns showed that light REY (LREY) and heavy REY (HREY) were preferentially adsorbed onto δ-MnO2 and FeOOH, respectively. It is noteworthy that ~27% of ΣREY was associated with the residual aluminosilicates phase of the WPO crusts. The La/Al ratios in the aluminosilicates phase of the typical SCS crusts were the values of the upper crust. We conclude that large amounts of terrigenous materials dilute the abundance of REY in the SCS crusts. In addition, the growth rates of Fe–Mn crusts have a negative correlation with the FeOOH-bound and aluminosilicate-bound REY. As a result of the fast growth rates, the SCS crusts contain relatively low concentrations of REY.

Noble gases have become a powerful tool to constrain the origin and evolution of ore-forming fluids in seafloor hydrothermal systems. The aim of this study was to apply these tracers to understand the genesis of newly discovered polymetallic sulphide deposits along the ultraslow-spreading Southwest Indian Ridge (SWIR). The helium, argon, and sulphur isotope compositions of metal sulphide minerals were measured for a number of active/inactive vent fields in the Indian Ocean. The helium concentrations and isotopic ratios in these ore samples are variable (4He: 0.09⁻2.42 × 10−8 cm3STP∙g−1; 3He: 0.06⁻3.28 × 10−13 cm3STP∙g−1; 3He/4He: 1.12⁻9.67 Ra) and generally greater than the modern atmosphere, but significantly lower than those in massive sulphides from the fast-spreading East Pacific Rise (EPR), especially for three Cu⁻Fe-rich samples from the ultramafic-hosted Tianzuo and Kairei vent fields. On the contrary, most of the SWIR sulphide deposits have somewhat higher 40Ar/36Ar ratios of trapped fluids (ranging from 290.6 to 303.4) when compared to the EPR ore samples. Moreover, the majority of sulphide minerals from the Indian Ocean have much higher δ34S values (3.0‰⁻9.8‰, ~5.9 on average, n = 49) than other basaltic-hosted active hydrothermal systems on the EPR. Overall, these He⁻Ar⁻S results are well within the range of seafloor massive sulphide deposits at global sediment-starved mid-ocean ridges (MORs), lying between those of air-saturated water (ASW) and mid-ocean ridge basalt (MORB) end members. Therefore, our study suggests that the helium was derived mainly from the MORB mantle by degassing during the high-temperature stage of hydrothermal activity, as well as from a mixture of vent fluids with variable amounts of ambient seawater during either earlier or late-stage low-temperature hydrothermal episodes, whereas the argon in ore-forming fluids trapped within sulphide minerals was predominantly derived from deep-sea water. Additionally, relatively high δ34S values exhibit a great estimated proportion (up to nearly 40%) of seawater-derived components. In summary, sub-seafloor extensive fluid circulation, pervasive low-temperature alteration, shallow seawater entrainment, and mixing processes, may make a larger contribution to the SWIR hydrothermal ore-forming systems, compared to fast-spreading centres.

In this study, the He and Ar isotope compositions were measured for the Fe-Mn polymetallic crusts and nodules from the South China Sea (SCS), using the high temperature bulk melting method and noble gases isotope mass spectrometry. The He and Ar of the SCS crusts/nodules exist mainly in the Fe-Mn mineral crystal lattice and terrigenous clastic mineral particles. The results show that the 3He concentrations and R/RA values of the SCS crusts are generally higher than those of the SCS nodules, while 4He and 40Ar concentrations of the SCS crusts are lower than those of the SCS nodules. Comparison with the Pacific crusts and nodules, the SCS Fe-Mn crusts/nodules have lower 3He concentrations and 3He/4He ratios (R/RA, 0.19 to 1.08) than those of the Pacific Fe-Mn crusts/nodules, while the 40Ar/36Ar ratios of the SCS samples are significantly higher than those of the Pacific counterparts. The relatively low 3He/4He ratios and high 40Ar concentrations in the SCS samples are likely caused by terrigenous detrital input with high radiogenic 4He and 40Ar contents. The SCS crusts and nodules have shorter growth periods, implying that in situ post-formation radiogenic 3He, 4He and 40Ar produced by decay of U, Th and K have no effect on their isotope compositions. Thus, the SCS crusts/nodules inherited the noble gases characteristics of their sources. Helium and Ar isotope compositions in the SCS Fe-Mn crusts and nodules reflect the product of an equilibrium mixture between air-saturated seawater and radiogenic components during their growth, while the partial 3He excess in some SCS samples may represent a little mantle-derived origin. The different He and Ar isotope compositions of the Fe-Mn crusts and nodules between the South China Sea and the Pacific Ocean are due to their different sources and genetic processes. The characteristics of He and Ar isotope compositions in the SCS polymetallic crusts and nodules are similar to the properties of hydrogenetic Fe-Mn oxide/hydroxide precipitates, which reflects mainly the product of an equilibrium mixture between air-saturated seawater and radiogenic components.