Structure of active human telomerase with telomere shelterin protein TPP1.

Human telomerase is a RNA-protein complex that extends the 3' end of linear chromosomes by synthesizing multiple copies of the telomeric repeat TTAGGG1. Its activity is a determinant of cancer progression, stem cell renewal and cellular aging2-5. Telomerase is recruited to telomeres and activated for telomere repeat synthesis by the telomere shelterin protein TPP16,7. Human telomerase has a bilobal structure with a catalytic core ribonuclear protein and a H and ACA box ribonuclear protein8,9. Here we report cryo-electron microscopy structures of human telomerase catalytic core of telomerase reverse transcriptase (TERT) and telomerase RNA (TER (also known as hTR)), and of telomerase with the shelterin protein TPP1. TPP1 forms a structured interface with the TERT-unique telomerase essential N-terminal domain (TEN) and the telomerase RAP motif (TRAP) that are unique to TERT, and conformational dynamics of TEN-TRAP are damped upon TPP1 binding, defining the requirements for recruitment and activation. The structures further reveal that the elements of TERT and TER that are involved in template and telomeric DNA handling-including the TEN domain and the TRAP-thumb helix channel-are largely structurally homologous to those in Tetrahymena telomerase10, and provide unique insights into the mechanism of telomerase activity. The binding site of the telomerase inhibitor BIBR153211,12 overlaps a critical interaction between the TER pseudoknot and the TERT thumb domain. Numerous mutations leading to telomeropathies13,14 are located at the TERT-TER and TEN-TRAP-TPP1 interfaces, highlighting the importance of TER-TERT and TPP1 interactions for telomerase activity, recruitment and as drug targets.

Structure of Tetrahymena telomerase-bound CST with polymerase α-primase.

Telomeres are the physical ends of linear chromosomes. They are composed of short repeating sequences (such as TTGGGG in the G-strand for Tetrahymena thermophila) of double-stranded DNA with a single-strand 3' overhang of the G-strand and, in humans, the six shelterin proteins: TPP1, POT1, TRF1, TRF2, RAP1 and TIN21,2. TPP1 and POT1 associate with the 3' overhang, with POT1 binding the G-strand3 and TPP1 (in complex with TIN24) recruiting telomerase via interaction with telomerase reverse transcriptase5 (TERT). The telomere DNA ends are replicated and maintained by telomerase6, for the G-strand, and subsequently DNA polymerase α-primase7,8 (PolαPrim), for the C-strand9. PolαPrim activity is stimulated by the heterotrimeric complex CTC1-STN1-TEN110-12 (CST), but the structural basis of the recruitment of PolαPrim and CST to telomere ends remains unknown. Here we report cryo-electron microscopy (cryo-EM) structures of Tetrahymena CST in the context of the telomerase holoenzyme, in both the absence and the presence of PolαPrim, and of PolαPrim alone. Tetrahymena Ctc1 binds telomerase subunit p50, a TPP1 orthologue, on a flexible Ctc1 binding motif revealed by cryo-EM and NMR spectroscopy. The PolαPrim polymerase subunit POLA1 binds Ctc1 and Stn1, and its interface with Ctc1 forms an entry port for G-strand DNA to the POLA1 active site. We thus provide a snapshot of four key components that are required for telomeric DNA synthesis in a single active complex-telomerase-core ribonucleoprotein, p50, CST and PolαPrim-that provides insights into the recruitment of CST and PolαPrim and the handoff between G-strand and C-strand synthesis.

Nanoporous Titanium Implant Surface Accelerates Osteogenesis via the Piezo1/Acetyl-CoA/ß-Catenin Pathway.

Osseointegration is the most important factor determining implant success. The surface modification of TiO2 nanotubes prepared by anodic oxidation has remarkable advantages in promoting bone formation. However, the mechanism behind this phenomenon is still unintelligible. Here we show that the nanomorphology exhibited open and clean nanotube structure and strong hydrophilicity, and the nanomorphology significantly facilitated the adhesion, proliferation, and osteogenesis differentiation of stem cells. Exploring the mechanism, we found that the nanomorphology can enhance mitochondrial oxidative phosphorylation (OxPhos) by activating Piezo1 and increasing intracellular Ca2+. The increase in OxPhos can significantly uplift the level of acetyl-CoA in the cytoplasm but not significantly raise the level of acetyl-CoA in the nucleus, which was beneficial for the acetylation and stability of ß-catenin and ultimately promoted osteogenesis. This study provides a new interpretation for the regulatory mechanism of stem cell osteogenesis by nanomorphology.

Melatonin activates Nrf2/HO-1 signalling pathway to antagonizes oxidative stress-induced injury via melatonin receptor 1 (MT1) in cryopreserved mice ovarian tissue.

Our previous research has shown that melatonin (MLT) can reduce cryopreserved ovarian damage in mice. Yet, the molecular mechanism of MLT protection is still unclear. Some studies have shown that melatonin receptor 1 (MT1) is very important for animal reproductive system. To evaluate whether MLT exerts its protective effect on cryopreserved mice ovarian tissue via MT1, we added antagonist of MT1/MT2 (Luzindor) or antagonist of MT2 (4P-PDOT) to the freezing solution, followed by cryopreservation and thawing of ovarian tissue. The levels of total superoxide dismutase (T-SOD), catalase (CAT), nitric oxide (NO) and malondialdehyde (MDA) were detected. Besides, by using RT-PCR and Western blotting, the expression of Bcl-2, Bax and Nrf2/HO-1 signalling pathway-related proteins was detected. These findings demonstrated that compared with the melatonin group, the addition of Luzindor increased apoptosis, NO and MDA activities, decreased CAT and T-SOD activities and inhibited Nrf2/HO-1 signalling pathway. In conclusion, melatonin can play a protective role in cryopreserved ovarian tissue of mice through MT1 receptor.

Global integrative meta-analysis of the responses in soil organic carbon stock to biochar amendment.

Applying biochar to soil has been recognized as a promising practice of climate-smart agriculture, with considerable potential in enhancing soil organic carbon (SOC) sequestration. Previous studies showed that biochar-induced increases in SOC stock varied substantially among experiments, while the explanatory factors responsible for such variability are still not well assessed. Here, we conducted an integrative meta-analysis of the magnitude and efficiency of biochar-induced change in SOC stock, using a database including 476 field measurements at 101 sites across the globe. Biochar amendment increased SOC stock by 6.13 ± 1.62 (95% confidence interval, CI) and 7.01 ± 1.11 (95% CI) Mg C ha-1, respectively, compared to their unfertilized (R0) and mineral nitrogen (N) fertilized (Rn) references. Of which approx. 52% (R0) and 50% (Rn) were contributed directly by biochar-C input. Corresponding biochar carbon efficiencies in R0 and Rn datasets were estimated as 58.20 ± 10.37% and 65.58 ± 9.26% (95% CI), respectively. The change magnitude of SOC stock increased significantly (p < 0.01) with the increasing amount of biochar-C input, while carbon efficiency of biochar showed an opposite trend. Biochar amendment sequestered larger amounts of SOC with higher efficiency in acidic and loamy soils than in alkaline and sandy soils. Biochar amendments with higher C/N ratio caused higher SOC increase than those with lower C/N ratio. Random forest (RF) algorithm showed that accumulative biochar-C input, soil pH, and biochar C/N ratio were the three most-important factors regulating the SOC stock responses. Overall, these results suggest that applying high C/N ratio biochar in acidic soils is a recommendable agricultural practice from the perspective of enhancing organic carbon.

Sirtuin3 Alleviated Influenza A Virus-Induced Mitochondrial Oxidative Stress and Inflammation in Lung Epithelial Cells via Regulating Poly (ADP-Ribose) Polymerase 1 Activity.

INTRODUCTION: Influenza A virus (IAV) infection causes severe lung inflammation and injury, particularly in children. Sirtuin3 (Sirt3) was confirmed to be effective in protecting the lung against injury. This study aims to explore the function and mechanism of Sirt3 on influenza development in children. METHODS: The Sirt3 level in serum samples from IAV-infected children and lung epithelial cells were detected using RT-qPCR, ELISA, and Western blot assays. Cell viability and apoptosis were determined by MTT and flow cytometry assays. Virus titration was conducted by determining TCID50. Cell inflammatory response was detected by a battery of inflammatory cytokines. The contents of ROS and ATP, mitochondrial membrane potential level, and oxygen-consumption rate were examined to reflect on oxidative stress and mitochondrial dysfunction. The activity of poly (ADP-ribose) polymerase 1 (PARP-1) was measured by colorimetry. RESULTS: Sirt3 was downregulated in IAV-infected children's serum samples and BEAS-2B cells. Overexpression of Sirt3 alleviated IAV replication and IAV-induced inflammatory injury, oxidative stress, and mitochondrial dysfunction in lung epithelial cells. Moreover, upregulation of Sirt3 deacetylated SOD2 and PARP-1 and inhibited the PARP-1 activity. Notably, the Sirt3 inhibitor (3-TYP) and PARP-1 activity agonist (nicotinamide) reversed the effects of Sirt3 overexpression on IAV replication and IAV-induced injury. CONCLUSION: Overexpression of Sirt3 attenuated IAV-evoked inflammatory injury and mitochondrial oxidative stress through the inhibition of PARP-1 activity in lung epithelial cells.

Inhibition of autophagic flux by the curcumin analog EF-24 and its antiproliferative effect on MCF-7 cancer cells.

5-Bis[(2-fluorophenyl)methylene]-4-piperidinone (EF-24) is a curcumin analog, which was identified for its physiochemical stability and diverse pharmacological functions. In the present study, EF-24 was added to the breast cancer cell line MCF-7 and its cellular effects were characterized. The results indicated that EF-24 possessed antiproliferative and antimigratory activities on MCF-7 cells as determined by MTT assay, wound healing, and transwell assay, respectively. In addition, the autophagosomal vesicles could be detected by acridine orange staining and electron microscope analysis in EF-24-treated cells. Conversion of LC3-I to LC3-II was also investigated following EF-24 treatment of the cells. However, the expression analysis of p62 and LC3 revealed that EF-24 could inhibit autophagic flux in MCF-7 cells. Confocal microscopy suggested that EF-24 could inhibit the degradation of autophagic vesicles by blocking the fusion of autophagosomes with lysosomes. EF-24 could also induce apoptosis of MCF-7 cells as determined by Hoechst 33342 staining, flow cytometry analysis, and western blot analysis. Moreover, treatment of the cells with the autophagy inhibitor 3-MA enhanced the PARP1 cleavage of EF-24-treated MCF-7 cells, which indicated the crosstalk between autophagy and apoptosis in breast cancer cells. Additional investigation of EF-24 should be performed in future studies to assess its antiproliferation and antimigratory effects on MCF-7 cells. However, the current results provide a solid foundation for the potential in vivo anticancer activity of this compound.

Effects of sericin on oxidative stress and PI3K/AKT/mTOR signal pathway in cryopreserved mice ovarian tissue.

Ovarian tissue cryopreservation is an effective fertility protective strategy for preadolescent female cancer patients, whose tumor treatment cannot be delayed. In the present study, the effects of sericin, as an antioxidant, on mice ovarian tissue freezing and thawing were investigated. Mice ovarian tissues were cryopreserved and thawed in medium containing 0.5% or 1%sericin (w/v), and 0.1 mM melatonin. Then, the follicular morphology was observed. The levels of antioxidant enzymes were determined, including glutathione (GSH), glutathione peroxidase (GSH-Px), total superoxide dismutase (T-SOD), total antioxidant capacity (T-AOC) and catalase (CAT). Moreover, the levels of nitric oxide (NO), malondialdehyde (MDA) and lactate dehydrogenase (LDH) were also tested. Besides, apoptosis-related proteins Bcl-2 and Bax were determined. Our results showed that 1% sericin maintained follicular morphology, inhibited apoptosis, decreased MDA and NO levels, and boosted endogenous antioxidant enzyme levels, while had no significant effect on LDH levels. Furthermore, these effects may be related with the activation of the phosphatidylinositol-3-kinase (PI3K)/protein kinase B (AKT)/mammalian target of Rapamycin (mTOR) signaling pathway, as demonstrated by increased PI3K, p-AKT and mTOR levels. These findings demonstrate that 1% sericin may reduce oxidative stress and protect ovarian tissues during freezing and thawing via PI3K/AKT/mTOR signaling pathway.

A structurally conserved human and Tetrahymena telomerase catalytic core.

Telomerase is a ribonucleoprotein complex that counteracts the shortening of chromosome ends due to incomplete replication. Telomerase contains a catalytic core of telomerase reverse transcriptase (TERT) and telomerase RNA (TER). However, what defines TERT and separates it from other reverse transcriptases remains a subject of debate. A recent cryoelectron microscopy map of Tetrahymena telomerase revealed the structure of a previously uncharacterized TERT domain (TRAP) with unanticipated interactions with the telomerase essential N-terminal (TEN) domain and roles in telomerase activity. Both TEN and TRAP are absent in the putative Tribolium TERT that has been used as a model for telomerase for over a decade. To investigate the conservation of TRAP and TEN across species, we performed multiple sequence alignments and statistical coupling analysis on all identified TERTs and find that TEN and TRAP have coevolved as telomerase-specific domains. Integrating the data from bioinformatic analysis and the structure of Tetrahymena telomerase, we built a pseudoatomic model of human telomerase catalytic core that accounts for almost all of the cryoelectron microscopy density in a published map, including TRAP in previously unassigned density as well as telomerase RNA domains essential for activity. This more complete model of the human telomerase catalytic core illustrates how domains of TER and TERT, including the TEN-TRAP complex, can interact in a conserved manner to regulate telomere synthesis.

Clinical Value of Long Non-Coding RNA HOTAIR in Carotid Artery Stenosis and Its Role in Vascular Smooth Muscle Cell Proliferation.

This study investigated the clinical role of HOTAIR in patients with carotid artery stenosis (CAS) and its mechanism in vascular smooth muscle cells (VSMCs). Patients with CAS were collected. The expression of HOTAIR was detected by quantitative real-time polymerase chain reaction (qRT-PCR). The clinical importance of HOTAIR was revealed by the receiver operating characteristic curve. Overexpression and knockdown of HOTAIR were achieved by transfecting pCDNA3.1-HOTAIR plasmid and si-HOTAIR respectively. CCK-8 assay or Transwell assay were used to analyze the changes in cell viability or migration after transfection treatments. Double luciferase reporter gene assay confirmed the targeted relationship between HOTAIR and miR-148b-3p. The levels of miR-148b-3p in VSMCs and patients were detected by qRT-PCR. Pearson analysis was used to analyze the relationship between HOTAIR and miR-148b-3p in patients with CAS. The expression of HOTAIR in patients with CAS was significantly higher than that in healthy individuals. HOTAIR appeared to discriminate CAS patients from healthy people. The overexpression of HOTAIR increased the viability and migration of VSMCs. Silenced HOTAIR restricted the abnormal viability and migration of VSMCs. A double luciferase reporter revealed a region of complementary binding between HOTAIR and miR-148b-3p. The expression of miR-148b-3p in VSMCs was regulated by the levels of HOTAIR. Reduction of miR-148b-3p expression was substantiated in CAS patients. Pearson analysis exhibited that the expression of HOTAIR was negatively relative to the levels of miR-148b-3p. The long noncoding RNA HOTAIR might be a diagnostic biomarker for CAS patients, and it was involved in the activity of vascular smooth muscle cells.

Sarcopenia as a novel prognostic factor in the patients of primary localized gastrointestinal stromal tumor.

BACKGROUND: Sarcopenia predicts poor prognosis of a variety of gastrointestinal malignancies. However, there is a lack of study on the association between skeletal muscle index (SMI) and the prognosis of gastrointestinal stromal tumor (GIST). The aim of this study is to develop a novel nomogram based on sarcopenia for GIST patients to predict overall survival (OS). METHODS: SMI was measured by computed tomography scan of 107 patients who underwent resection for primary localized gastrointestinal stromal tumor (GIST). Sarcopenia was defined by cutoff values for SMI as 40.1 cm2/m2 and 39.8 cm2/m2 using optimum stratification for males and females respectively. Factors were included in the nomogram were specified by univariate and multiple Cox proportional hazard analysis. Concordance index (C-index) and calibration curves were conducted to measure the discrimination and accuracy of the nomogram. The utility of the nomogram was assessed by the decision curve analysis (DCA). RESULTS: Twenty-eight (26.2%) of 107 patients were sarcopenic. Sarcopenia was correlated significantly with body mass index, albumin, female sex, resection style, mitotic index, rupture status, survival. Sarcopenia was significantly related to decreased overall survival (p = 0.003).The nomogram including sarcopenia status, resection style and mitotic index had an excellent discrimination with C-index 0.794. The calibration curves represented a good accordance between the actual observation and nomogram prediction for overall survival. Decision curve analysis illustrated that the nomogram was helpful in clinic. CONCLUSIONS: We developed a nomogram based on sarcopenia to predict overall survival after resection of GISTs which is an effective and favorable prognostication tool.

Photosynthetic resistance and resilience under drought, flooding and rewatering in maize plants.

Abnormally altered precipitation patterns induced by climate change have profound global effects on crop production. However, the plant functional responses to various precipitation regimes remain unclear. Here, greenhouse and field experiments were conducted to determine how maize plant functional traits respond to drought, flooding and rewatering. Drought and flooding hampered photosynthetic capacity, particularly when severe and/or prolonged. Most photosynthetic traits recovered after rewatering, with few compensatory responses. Rewatering often elicited high photosynthetic resilience in plants exposed to severe drought at the end of plant development, with the response strongly depending on the drought severity/duration. The associations of chlorophyll concentrations with photosynthetically functional activities were stronger during post-tasseling than pre-tasseling, implying an involvement of leaf age/senescence in responses to episodic drought and subsequent rewatering. Coordinated changes in chlorophyll content, gas exchange, fluorescence parameters (PSII quantum efficiency and photochemical/non-photochemical radiative energy dissipation) possibly contributed to the enhanced drought resistance and resilience and suggested a possible regulative trade-off. These findings provide fundamental insights into how plants regulate their functional traits to deal with sporadic alterations in precipitation. Breeding and management of plants with high resistance and resilience traits could help crop production under future climate change.

Responses of soil organic carbon stock to animal manure application: A new global synthesis integrating the impacts of agricultural managements and environmental conditions.

Enhancing soil organic carbon (SOC) through applying animal manure is of interest for both sustaining cereal production and mitigating greenhouse gas (GHG) emissions. Previous syntheses showed that manuring-induced SOC changes varied substantially with agricultural managements and environmental conditions, while their significance and relative importance to such variability are still largely uncertain. Here, we presented a new synthesis using an updated and balanced database integrating the manuring-induced SOC stock changes and their plausible explanatory factors in 250 observations at global 120 sites. Manure application increased SOC stock by 7.41 ± 1.14 (95% confidence interval, CI) and 8.96 ± 1.83 (95% CI) Mg C ha-1 , respectively, compared to their mineral fertilized (REF-min) and unfertilized (REF-zero) references. Of which approx. 72% and 34% were directly contributed by manure-C input, respectively. Following the IPCC (Intergovernmental Panel on Climate Change) approach, these changes corresponded to the manuring-induced SOC change factors of 1.27 ± 0.04 (95% CI) and 1.40 ± 0.08 (95% CI), respectively. Basing on a balanced database, we identified the amount of manure-C input as the most important factor to the global variations in the resultant SOC stock changes. More importantly, our integrative analysis distinguished the significance of soil properties (e.g., soil pH and initial SOC content) in regulating the efficiency of manure application in enhancing SOC stock. These results indicate that, at the similar rate, applying manure could sequestrate much more carbon in alkaline soils than in neutral and acidic soils. By integrating the impacts of agricultural managements and environmental conditions, our findings would help to develop region-specific tailor-made manure application measures in agriculture and to refine the SOC change factors for regional GHG inventories.

Melatonin induction of HSP90 expression exerts cryoprotective effect on ovarian tissue.

Our previous study revealed that melatonin (MLT) protected the quality of cryopreserved ovarian tissues in mice. This work was carried out to examine the role of MLT in inducing HSP90 expression of ovarian tissue for achieving cryoprotection. Pieces of ovarian tissues were obtained from 50 female rats treated with MLT at 0, 0.001, 0.01, 0.1, and 1 mM, respectively. After cryopreservation-thawing, HSP90 mRNA and protein level were evaluated using qRT-PCR and western blot. The qRT-PCR results revealed that HSP90 mRNA expression was significantly (p < 0.01) upregulated in MLT-treated groups in comparison with the controls (0 mM). Western blot revealed higher HSP90 protein expression in MLT-treated groups compared to control group (0 mM), thus further confirming that MLT positively affected HSP90 expression. Moreover, 0.1 mM MLT had better effects than other concentrations of MLT. Conclusively, findings in the present work provide a feasible technology for improving cryopreserved ovarian tissue quality through the addition of MLT to elicit HSP90 expression.

The molecular mechanism of dsRNA processing by a bacterial Dicer.

Members of the ribonuclease (RNase) III family regulate gene expression by processing dsRNAs. It was previously shown that Escherichia coli (Ec) RNase III recognizes dsRNA with little sequence specificity and the cleavage products are mainly 11 nucleotides (nt) long. It was also shown that the mutation of a glutamate (EcE38) to an alanine promotes generation of siRNA-like products typically 22 nt long. To fully characterize substrate specificity and product size of RNase IIIs, we performed in vitro cleavage of dsRNAs by Ec and Aquifex aeolicus (Aa) enzymes and delineated their products by next-generation sequencing. Surprisingly, we found that both enzymes cleave dsRNA at preferred sites, among which a guanine nucleotide was enriched at a specific position (+3G). Based on sequence and structure analyses, we conclude that RNase IIIs recognize +3G via a conserved glutamine (EcQ165/AaQ161) side chain. Abolishing this interaction by mutating the glutamine to an alanine eliminates the observed +3G preference. Furthermore, we identified a second glutamate (EcE65/AaE64), which, when mutated to alanine, also enhances the production of siRNA-like products. Based on these findings, we created a bacterial Dicer that is ideally suited for producing heterogeneous siRNA cocktails to be used in gene silencing studies.

Hypoxia-induced exosomes promote hepatocellular carcinoma proliferation and metastasis via miR-1273f transfer.

Exosomes are present within the local hypoxic tumor microenvironment, where they are able to transfer microRNAs between cells, thereby, effectively mediating cell-cell communication. Hypoxia plays a pivotal role in the progression of many tumor types such as hepatocellular carcinoma (HCC), but how hypoxia-induced exosomes in HCC affect HCC cells remains uncertain. In the present study, we found that hypoxic conditions induced increased exosomal production by HCC cells, and these exosomes, in turn, enhanced the proliferation, migration, and invasiveness in addition to epithelial-to-mesenchymal transition (EMT) in HCC cells under normoxic conditions. When we analyzed these exosomes, we found that miR-1273f were present at higher levels under hypoxic conditions, and we determined that this miRNA was responsible for directly replicating the effects of hypoxic exosomes within HCC cells, in addition to activating the Wnt/ß-catenin signaling. We finally identified LHX6, which is a known inhibitor of the Wnt/ß-catenin pathway, to be a miR-1273f target. These results, thus, provide evidence that hypoxic conditions can lead HCC cells to express increased exosomes that facilitate miR-1273f expression in normoxic cells, thereby enhancing their malignant phenotype at least in part by targeting LHX6 for downregulation.

Antioxidative effect of melatonin on cryopreserved ovarian tissue in mice.

Cryopreservation of ovarian tissues (OTs) has become the most effective way to preserve the fertility of female cancer patients. However, cryopreservation of OTs is still relatively at an experimental stage. The aim of study is to examine the effect of melatonin (MTL) on cryopreserved-thawed OTs. Fragments of OTs were cryopreserved in medium containing different concentrations (0 mM, 0.001 mM, 0.01 mM, 0.1 mM and 1 mM) of MLT. The endogenous enzymes (GSH-PX, GSH, SOD, CAT and T-AOC), MDA and ROS levels were all evaluated after cryopreservation. Our results showed that the 0.1 mM of MLT significantly improved the survival and diameter of follicles (P < 0.001). Meanwhile, the antioxidant enzymes activities (including GSH-PX, GSH, SOD, CAT and T-AOC) were enhanced and MDA content were significantly decreased in 0.1 mM of MLT group compared to other groups (P < 0.001). Additionally, compared to the control group, MTL of 0.1 mM resulted in a significantly lower ROS level. In conclusion, MLT protects the quality of cryopreserved OTs by decreasing oxidative stress level and the optimal concentration is 0.1 mM.

A Novel Bilinear Feature and Multi-Layer Fused Convolutional Neural Network for Tactile Shape Recognition.

Convolutional neural networks (CNNs) can automatically learn features from pressure information, and some studies have applied CNNs for tactile shape recognition. However, the limited density of the sensor and its flexibility requirement lead the obtained tactile images to have a low-resolution and blurred. To address this issue, we propose a bilinear feature and multi-layer fused convolutional neural network (BMF-CNN). The bilinear calculation of the feature improves the feature extraction capability of the network. Meanwhile, the multi-layer fusion strategy exploits the complementarity of different layers to enhance the feature utilization efficiency. To validate the proposed method, a 26 class letter-shape tactile image dataset with complex edges was constructed. The BMF-CNN model achieved a 98.64% average accuracy of tactile shape. The results show that BMF-CNN can deal with tactile shapes more effectively than traditional CNN and artificial feature methods.

A 4-year field measurement of N2O emissions from a maize-wheat rotation system as influenced by partial organic substitution for synthetic fertilizer.

Soil N2O emissions depend on the status of stoichiometric balance between organic C and inorganic N. As a beneficial management practice to sustain soil fertility and crop productivity, partial substitution of organic fertilizers (OFs) for synthetic fertilizers (SFs) can directly affect this balance status and regulate N2O emissions. However, no multi-year field studies of N2O emissions under different ratios of OFS to SFs have been performed. We conducted a 4-year experiment to measure N2O emissions in a maize-wheat rotation in central China. Six treatments were included: total SF (TS), total OF, no N fertilizer, and ratios of to SF with 1: 2 (LO), 1: 1 (MO), and 2: 1 (HO), based on N content. Two incubation experiments were performed to further interpret the field data. In the first year, cumulative N2O emissions (kg N ha-1) in LO, MO, and HO were 4.59, 4.68, and 3.59, respectively, significantly lower than in TS (6.67). However, from the second year onwards, organic substitution did not reduce N2O emissions and even significantly enhanced them in the fourth year relative to TS. Soil respiration under OF-amended soils increased over the course of the experiment. From the second year onwards, there was no marked difference in mineral N concentrations between OF- and SF-amended soils. OF caused a drop in soil pH. Cumulative N2O was negatively correlated with pH. Long-term organic substitution enhanced N2O emissions produced via denitrification rather than nitrification and resulted in higher temperature sensitivity of N2O emissions than TS. The enhanced N2O emissions from the OF-treated soils were mainly attributable to accelerated OF decomposition, increased denitrification-N2O emissions, and lessened N2O reduction due to lower pH and greater NO3-. These results indicate that OF substitution can reduce N2O emissions in the first year, but in the long-term it can increase emissions, especially as soils warm.

The diversity between curatively resected pancreatic head and body-tail cancers based on the 8th edition of AJCC staging system: a multicenter cohort study.

BACKGROUND: To our knowledge, there are no studies to systematically compare the detailed clinical significance between curatively resected pancreatic head (ph) and body-tail (pbt) ductal adenocarcinoma based on the new 8th edition of AJCC staging system (8th AJCC stage) that was just applied in clinical practice in 2018. METHODS: Three hundred fifty-one patients with curatively resected pancreatic adenocarcinoma (PC) from three center hospitals were entered into this multicenter cohort study. RESULTS: Increasing tumor size (P < 0.001), T stage (T1 + T2 vs T3 + T4, P = 0.003), frequent postoperative liver metastasis (PLM) (P = 0.002) and 8th AJCC stage (IA to VI, P < 0.001; I + II vs III + IV, P = 0.002) were closely associated with the progression of pbt cancers compared with that in ph cancer patients. Moreover, tumor size≥3 cm (P = 0.012), 8th AJCC stage (III + IV) (P = 0.025) and PLM (P = 0.010) were identified as independent risk factors in pbt cancers in logistic analysis. Patients with pbt cancers had a significantly worse overall survival compared with ph cancer patients (P = 0.003). Moreover, pbt was an independent unfavorable factor in multivariate analysis (P = 0.011). In addition to lymph nodes metastasis, 8th AJCC stage, vascular invasion and PLM, increasing tumor size and advanced T stage were also closely associated with the poor prognosis in 131 cases of pbt cancer patients compared with Ph cancer patients. CONCLUSION: Pbt, as an independent unfavorable factor for the prognosis of PC patients, are much more aggressive than that in ph cancers according to 8th AJCC staging system. 8th AJCC staging system are more comprehensive and sensitive to reflect the malignant biology of pbt cancers.