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1.
Macromol Biosci ; : e1900394, 2020 Feb 17.
Artigo em Inglês | MEDLINE | ID: mdl-32065462

RESUMO

Many coating materials have been studied to prevent surgical site infections (SSIs). However, antibacterial coating on surfaces show weak adhesion using the traditional titanium (Ti) cage, resulting in low efficacy for preventing SSIs after spinal surgery. Herein, a 3D-printed Ti cage combined with a drug-releasing system is developed for in situ drug release and bacteria killing, leading to prevention of SSIs in vitro and in vivo. First, a 3D-printed Ti cage is designed and prepared by the Electron Beam Melting (EBM) method. Second, polyvinyl alcohol (PVA) containing hydrophilic vancomycin hydrochloride (VH) is scattered across the surface of 3D-printed porous Ti (Ti-VH@PVA) cages. Ti-VH@PVA cages show an efficient drug-releasing profile and excellent bactericidal effect for three common bacteria after more than seven days in vitro. In addition, Ti-VH@PVA cages exhibit reliable inhibition of inflammation associated with Staphylococcus aureus and effective bone regeneration capacity in a rabbit model of SSIs. The results indicate that Ti-VH@PVA cages have potential advantages for preventing SSIs after spinal surgery.

2.
Mol Genet Genomic Med ; : e1112, 2020 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-32061057

RESUMO

BACKGROUND: Long noncoding RNA (LncRNA) XIST is one of the genes that exists in different types of cancers. Earlier researches showed that XIST can advance the progression of colorectal cancer. Nevertheless, the potential molecular mechanism of XIST in combination with miR-93-5p has not been explored in colorectal cancer. METHODS: We performed qRT-PCR to explore the level of XIST. And a serious experiments in vitro and in vivo were performed to explore the function of XIST. The relationship between XIST/HIF-1A and miR-93-5p was confirmed by RIP and dual-luciferase assays. RESULTS: In the present research, our team demonstrated the upregulation of XIST expression, which was related to tumor progression, and the downregulation of miR-93-5p in cells and tissues of colorectal cancer. XIST is the competitive endogenous RNA of miR-93-5p to promote HIF-1A, and then the upregulated AXL level facilitates the EMT process, migration, and proliferation of colorectal cancer. At last, we proved that XIST enhanced the in vivo and in vitro activities of colorectal cancer by regulating AXL signaling. CONCLUSION: In summary, the above results indicate that XIST promotes colorectal cancer tumorigenesis by regulating miR-93-5p/HIF-1A/AXL signaling pathway, which will supply a novel perspective to diagnose and treat colorectal cancer disease.

3.
Cell Commun Signal ; 18(1): 27, 2020 Feb 17.
Artigo em Inglês | MEDLINE | ID: mdl-32066462

RESUMO

BACKGROUND: Excessive light exposure is a detrimental environmental factor that plays a critical role in the pathogenesis of retinal degeneration. However, the mechanism of light-induced death of retina/photoreceptor cells remains unclear. The mammalian/mechanistic target of rapamycin (mTOR) and Poly (ADP-ribose) polymerase-1 (PARP-1) have become the primary targets for treating many neurodegenerative disorders. The aim of this study was to elucidate the mechanisms underlying light-induced photoreceptor cell death and whether the neuroprotective effects of mTOR and PARP-1 inhibition against death are mediated through apoptosis-inducing factor (AIF). METHODS: Propidium iodide (PI)/Hoechst staining, lentiviral-mediated short hairpin RNA (shRNA), Western blot analysis, cellular fraction separation, plasmid transient transfection, laser confocal microscopy, a mice model, electroretinography (ERG), and hematoxylin-eosin (H & E) staining were employed to explore the mechanisms by which rapamycin/3-Aminobenzamide (3AB) exert neuroprotective effects of mTOR/PARP-1 inhibition in light-injured retinas. RESULTS: A parthanatos-like death mechanism was evaluated in light-injured 661 W cells that are an immortalized photoreceptor-like cell line that exhibit cellular and biochemical feature characteristics of cone photoreceptor cells. The death process featured over-activation of PARP-1 and AIF nuclear translocation. Either PARP-1 or AIF knockdown played a significantly protective role for light-damaged photoreceptors. More importantly, crosstalk was observed between mTOR and PARP-1 signaling and mTOR could have regulated parthanatos via the intermediate factor sirtuin 1 (SIRT1). The parthanatos-like injury was also verified in vivo, wherein either PARP-1 or mTOR inhibition provided significant neuroprotection against light-induced injury, which is evinced by both structural and functional retinal analysis. Overall, these results elucidate the mTOR-regulated parthanatos death mechanism in light-injured photoreceptors/retinas and may facilitate the development of novel neuroprotective therapies for retinal degeneration diseases. CONCLUSIONS: Our results demonstrate that inhibition of the mTOR/PARP-1 axis exerts protective effects on photoreceptors against visible-light-induced parthanatos. These protective effects are conducted by regulating the downstream factors of AIF, while mTOR possibly interacts with PARP-1 via SIRT1 to regulate parthanatos. Video Abstract Schematic diagram of mTOR interacting with PARP-1 to regulate visible light-induced parthanatos. Increased ROS caused by light exposure penetrates the nuclear membrane and causes nuclear DNA strand breaks. PARP-1 detects DNA breaks and synthesizes PAR polymers to initiate the DNA repair system that consumes a large amount of cellular NAD+. Over-production of PAR polymers prompts the release of AIF from the mitochondria and translocation to the nucleus, which leads to parthanatos. Activated mTOR may interact with PARP-1 via SIRT1 to regulate visible light-induced parthanatos.

4.
Clin Respir J ; 2020 Feb 04.
Artigo em Inglês | MEDLINE | ID: mdl-32017385

RESUMO

INTRODUCTION: Hypercapnia has been shown to attenuate ventilator-induced lung injury (VILI). However, the underlying mechanism of this protective effect is not clear. OBJECTIVES: The current study investigated the role of vagus nerve activation in the protective effects of hypercapnia in VILI rats. METHODS: Male Sprague-Dawley rats were randomized to either high-tidal volume (30 ml/kg) or low-tidal volume ventilation (8 ml/kg, control) and monitored for 4 h. The high-tidal volume group was further divided into either a vagotomy or sham-operated group and each surgery group was further divided into two subgroups (n = 8/group): normocapnia (FiCO2 , 0.0; target PaCO2 = 35-45 mmHg) and hypercapnia (FiCO2, 0.5; target PaCO2 = 80-100 mmHg). Injuries were assessed hourly through hemodynamics, respiratory mechanics and gas exchange. Protein concentration, cell count and cytokines (TNF-α and IL-8) in bronchoalveolar lavage fluid (BALF), lung wet-to-dry weight and pathological changes were examined after 4 h ventilation. Vagus nerve activity was measured for 1 h at the beginning of the experiment. RESULTS: Compared to the control group, injurious ventilation resulted in a decrease in PaO2 /FiO2 and greater lung static compliance, MPO activity, enhanced BALF cytokines (TNF-α and IL-8), protein concentration, cell count, and histology injury score. Conversely, hypercapnia significantly improved VILI by decreasing the above injury parameters. However, vagotomy abolished the protective effect of hypercapnia on VILI. In addition, hypercapnia enhanced efferent vagus nerve activity compared to normocapnia. CONCLUSIONS: These results indicate that the vagus nerve plays an important role in mediating the anti-inflammatory effect of hypercapnia on VILI.

5.
Aging (Albany NY) ; 12(2): 1656-1684, 2020 Jan 29.
Artigo em Inglês | MEDLINE | ID: mdl-32003759

RESUMO

Immune cell infiltration mediates therapeutic response to immune therapies. The investigation on the genes regulating leukocyte migration may help us to understand the mechanisms regulating immune cell infiltration in tumor microenvironment. Here, we collected the data from Chinese Glioma Genome Atlas (CGGA) and The Cancer Genome Atlas (TCGA) to analyze the expression of leukocyte migration related genes in glioblastoma (GBM). Lymphocyte specific protein 1 (LSP1) was identified as the only gene in this family which not only has an elevated expression, but also serve as an independent predictive factor for progressive malignancy in glioma. We further confirmed these results in clinical glioma samples by quantitative PCR, immunofluorescence, immunohistochemistry, and western blot. Moreover, LSP1 expression was closely related to the response to radio- and chemotherapy in GBM, and positively correlated with immunosuppressive cell populations, including M2 macrophages, neutrophil, and regulatory T cell. Additionally, elevated LSP-1 expression enhanced the expression of immunosuppression related genes like programmed cell death 1 (PD1) and leukocyte associated immunoglobulin like receptor 1 (LAIR1) in macrophages. LSP1 also promoted the migration of macrophages. Together, our study suggests a novel role of LSP1 contributing to immunosuppressive microenvironment in GBM and serving as a potential therapeutic target for it.

6.
Chem Commun (Camb) ; 2020 Jan 31.
Artigo em Inglês | MEDLINE | ID: mdl-32003369

RESUMO

Hydroxyl alkylation of indoles by Friedel-Crafts reaction with a carbonyl compound is a useful strategy. However, the reaction was restricted to ketones due to the easy formation of a bisindole byproduct. Therefore, hydroxyl alkylation of an aldehyde with indole is confronted with great challenges. Here, we report an efficient strategy for asymmetric hydroxyl alkylation of 2-substituted indoles with aldehydes under 0.1 mol% chiral phosphoric acid. A series of α-hydroxyl ketones were obtained in high yields (up to 99%) and good enantioselectivities (up to 97%).

7.
J Phys Chem Lett ; 2020 Feb 12.
Artigo em Inglês | MEDLINE | ID: mdl-32048849

RESUMO

Recent years have witnessed various in-depth researches of self-reconstruction behavior toward electrocatalysis. Tracking the phase transformation and evolution of true active sites are of great significance for the development of self-reconstructed electrocatalysts. Here, the optimized atomic sulfur-doped bismuth nanobelt (S-Bi) is fabricated via an electrochemical self-reconstruction evolved from Bi2S3. Advanced technologies have demonstrated that the nonmetallic S atoms has been doped into the lattice of Bi frame, leading to the reconstruction of local electronic structure of Bi. The as-prepared S-Bi nanobelt exhibits a remarkable NH3 generation rate of 10.28 µg h-1 mg-1 and Faradaic efficiency of 10.48%. Density function theory (DFT) calculations prove that the S-doping can significantly lower the energy barrier of the rate-determining step and enlarge the N≡N bond for further dissociation towards N2 fixation. This work not only establishes insights into the evolution process of electrochemical-derived self-reconstruction, but also unravels the root of the NRR mechanism associated with the atomic nonmetal dopants.

8.
Curr Cardiol Rep ; 22(4): 19, 2020 Feb 08.
Artigo em Inglês | MEDLINE | ID: mdl-32036477

RESUMO

PURPOSE OF REVIEW: Endothelial cells are of great importance in many types of diseases including the coronary artery diseases in heart and stroke in brain. In this review, we explore the heterogeneity among endothelial cells from an organism-wide, organ-specific, and healthy versus disease perspective. RECENT FINDINGS: Recent studies addressing the cellular heterogeneity between arterial versus venous endothelial cells (ECs) have revealed that arterial ECs have tighter junctions, a decreased immune response, anticoagulant properties while veins have both anticoagulant and procoagulant properties. Blood and lymphatic ECs are quite distinct from each other as well, with the lymphatic ECs being more involved in the immune response and lymphangiogenesis while blood vessel ECs being involved in angiogenesis and maintenance of perfusion throughout the body. ECs from various organs such as the heart, the lung, and especially the brain are quite heterogeneous and provide barriers that prevent small particles to pass through the endothelium when compared with the endothelium of the liver and the kidney that are quite porous. The heart ECs have higher angiogenesis and metabolic rates (oxidation and glycolysis) than lung, liver, and kidney ECs. Ex vivo liver and kidney ECs grow at a moderate pace, while the lung and brain ECs grow very slowly. ECs from within a tumor have fenestrae and large intracellular gaps and junctions leading to increased permeability and tumor cell overgrowth. There is a large degree of heterogeneity among organism-wide and organ-specific ECs as well as between healthy and disease-specific ECs. We believe this review will help highlight the EC heterogeneity and further advance our ability to treat cardiovascular disease and other conditions.

9.
Chemistry ; 2020 Feb 11.
Artigo em Inglês | MEDLINE | ID: mdl-32043700

RESUMO

The development of cost-effective and durable oxygen electrocatalysts remains highly critical but challenging for energy conversion and storage devices. Herein, a novel FeNi alloy nanoparticle core encapsulated in carbon shells supported on a N-enriched graphene-like carbon matrix (denoted as FeNi@C/NG) was constructed by facile pyrolyzing the mixture of metal salts, glucose, and dicyandiamide. The in situ pyrolysis of dicyandiamide in the presence of glucose plays a significant effect on the fabrication of the porous FeNi@C/NG with a high content of doped N and large specific surface area. The optimized FeNi@C/NG catalyst displays not only a superior catalytic performance for the oxygen reduction reaction (ORR, with an onset potential of 1.0 V and half-wave potential of 0.84 V) and oxygen evolution reaction (OER, the potential at 10 mA cm-2 is 1.66 V) simultaneously in alkaline, but also outstanding long-term cycling durability. The excellent bifunctional ORR/OER electrocatalytic performance is ascribed to the synergism of the carbon shell and FeNi alloy core together with the high-content of nitrogen doped on the large specific surface area graphene-like carbon.

10.
Chin Med J (Engl) ; 2020 Feb 07.
Artigo em Inglês | MEDLINE | ID: mdl-32044814

RESUMO

BACKGROUND: A novel coronavirus (2019-nCoV) causing an outbreak of pneumonia in Wuhan, Hubei province of China was isolated in January 2020. This study aims to investigate its epidemiologic history, and analyzed the clinical characteristics, treatment regimens, and prognosis of patients infected with 2019-nCoV during this outbreak. METHODS: Clinical data from 137 2019-nCoV-infected patients admitted to the respiratory departments of nine tertiary hospitals in Hubei province from December 30, 2019 to January 24, 2020 were collected, including general status, clinical manifestations, laboratory test results, imaging characteristics, and treatment regimens. RESULTS: None of the 137 patients (61 males, 76 females, aged 20-83 years, mean age 55 ±â€Š16 years) had a definite history of exposure to Huanan Seafood Wholesale Market. Major initial symptoms included fever (112/137, 81.8%), coughing (66/137, 48.2%), and muscle pain or fatigue (44/137, 32.1%), with other, less typical initial symptoms observed at low frequency, including heart palpitations, diarrhea, and headache. Nearly 80% of the patients had normal or decreased white blood cell counts, and 72.3% (99/137) had lymphocytopenia. Lung involvement was present in all cases, with most chest computed tomography scans showing lesions in multiple lung lobes, some of which were dense; ground-glass opacity co-existed with consolidation shadows or cord-like shadows. Given the lack of effective drugs, treatment focused on symptomatic and respiratory support. Immunoglobulin G was delivered to some critically ill patients according to their condition. Systemic corticosteroid treatment did not show significant benefits. Notably, early respiratory support facilitated disease recovery and improved prognosis. The risk of death was primarily associated with age, underlying chronic diseases, and median interval from the appearance of initial symptoms to dyspnea. CONCLUSIONS: The majority of patients with 2019-nCoV coronavirus pneumonia present with fever as the first symptom, and most of them still showed typical manifestations of viral pneumonia on chest imaging. Middle-aged and elderly patients with underlying comorbidities are susceptible to respiratory failure and may have a poorer prognosis.

11.
DNA Cell Biol ; 2020 Jan 21.
Artigo em Inglês | MEDLINE | ID: mdl-31968179

RESUMO

Pancreatic ductal adenocarcinoma (PDAC) is one of the deadly tumors in digestive tract tumors. Although there has been advancement in PDAC treatment, its prognosis still remains unsatisfactory, mainly because of dismal diagnosis. This article aims to develop new prognostic factors related to energy metabolism in PDAC and to use these genes for novel risk stratification. Hundred fifty messenger RNA (mRNA) expression profiles and clinicopathological data of PDAC were downloaded from The Cancer Genome Atlas dataset. The glycolysis pathway was the significant pathway based on the gene set enrichment analysis. We chose the glycolysis pathway-related 176 genes for further analysis. Multivariate Cox regression analysis and forward stepwise Cox regression model established a novel three-gene glycolytic signature (including MET, B3GNT3, and SPAG4) for PDAC patients' prognosis prediction. All 150 patients were classified into two groups by the median risk score. High-risk group had a worse outcome compared to the low-risk group. The risk score was also significantly correlated with age and radiotherapy. A nomogram, including the glycolytic gene signature, has shown some clinical net benefit for overall survival prediction. We also validated the validity and reliability in the Puleo dataset. This novel gene expression signature may be involved in the pathophysiology and used for risk stratification and prognosis prediction in PDAC.

12.
Genetics ; 2020 Jan 24.
Artigo em Inglês | MEDLINE | ID: mdl-31980449

RESUMO

Sex determination is remarkably variable amongst animals with examples of environmental sex determination, male heterogametic (XX/XY) and female heterogametic (ZZ/ZW) chromosomal sex determination, and other genetic mechanisms. The cephalochordate amphioxus occupies a key phylogenetic position as a basal chordate and outgroup to vertebrates, but its sex determination mechanism is unknown. During the course of generating Nodal mutants with transcription activator-like effector nucleases (TALENs) in amphioxus Branchiostoma floridae, serendipitously we generated three mutant strains that reveal the sex determination mechanism of this animal. In one mutant strain, all heterozygous mutant offspring over three generations were female and all wild-type descendants were male. This pattern suggests the Nodal allele targeted is on a female-specific W chromosome. A second mutant showed the same W-linked inheritance pattern, with a female heterozygote passing the mutation only to daughters. In a third mutant strain, both male and female offspring could be heterozygous but a female heterozygote only passed the mutation to sons. This pattern is consistent with the targeted allele being on a Z chromosome. We found an indel polymorphism linked to a Nodal allele present in most females but no males in our cultured population. Together, these results indicate that Nodal is sex chromosome-linked in B. floridae, and that B. floridae has a ZZ/ZW sex chromosome system.

13.
Artigo em Inglês | MEDLINE | ID: mdl-31980929

RESUMO

PURPOSE: In this retrospective study, we evaluated the treatment patterns and survival after positron emission tomography-computed tomography (PET/CT)-guided local consolidation therapy (LCT) for oligometastatic non-small cell lung cancer (NSCLC). METHODS: We reviewed the medical records of Chinese patients with oligometastatic stage IV non-small cell lung cancer (≤ 5 metastases) who had undergone PET/CT and were eligible for systemic therapy at two centers between May 2005 and August 2019. Propensity score matching (1:1) was used to reduce selection bias and imbalanced distribution of confounding factors. RESULTS: We identified 84 eligible patients and used propensity scores to create well-matched groups of 35 patients who did or did not undergo LCT. Among all patients, the 1-year overall survival (OS) rate was 47.6% and the 2-year OS rate was 22.6%. Relative to the group that did not receive LCT, the LCT group had a significantly higher OS rate (13 months vs. 7 months, p = 0.002). The two groups had similar incidences and classifications of LCT-related side effects. In multivariable analysis, LCT was found to be strongly associated with a favorable OS (hazard ratio: 0.508, 95% confidence interval: 0.311-0.828, p = 0.001). CONCLUSION: We concluded that LCT was significantly associated with improved clinical outcomes among the Chinese patients with oligometastatic NSCLC who were eligible for systemic treatment and could undergo PET/CT evaluation.

14.
J Vis Exp ; (155)2020 Jan 07.
Artigo em Inglês | MEDLINE | ID: mdl-31984954

RESUMO

Single cell mRNA sequencing has made significant progress in the last several years and has become an important tool in the field of developmental biology. It has been successfully used to identify rare cell populations, discover novel marker genes, and decode spatial and temporal developmental information. The single cell method has also evolved from the microfluidic based Fluidigm C1 technology to the droplet-based solutions in the last two to three years. Here we used the heart as an example to demonstrate how to profile the mouse embryonic tissue cells using the droplet based scRNA-Seq method. In addition, we have integrated two strategies into the workflow to profile multiple samples in a single experiment. Using one of the integrated methods, we have simultaneously profiled more than 9,000 cells from eight heart samples. These methods will be valuable to the developmental biology field by providing a cost-effective way to simultaneously profile single cells from different genetic backgrounds, developmental stages, or anatomical locations.

15.
Dalton Trans ; 49(6): 1975-1980, 2020 Feb 14.
Artigo em Inglês | MEDLINE | ID: mdl-31984993

RESUMO

Infrared (IR) nonlinear optical (NLO) materials are of great importance in laser technology, which could be applied in many civil and military fields. However, the low laser damage threshold and two-photon absorption, caused by the small bandgap, have hindered the applications of commercial IR NLO materials. In this work, Li2CdSiS4, with a wide bandgap (3.76 eV) and a moderate second-harmonic generation (SHG) response (1 × AgGaS2) was successfully designed and fabricated by a high temperature flux method in vacuum and sealed quartz tubes. The compound with a wurtz-stannite structure type was constructed with hexagonal close packing tetrahedra and it meets the requirements of optimal IR NLO material properties. Theoretical results show that Li2CdSiS4 has an indirect bandgap, and the bandgap is determined by the S 3p and Si 3p orbitals, not by the massive Cd element, which enables Li2CdSiS4 to have a wider bandgap than those of other Cd-obtained chalcogenides. In addition, the SHG response originates mainly from the S2- and Cd2+ of CdS4 tetrahedra while the contributions of Li and Si in this compound are ignorable. All the above information indicates that Li2CdSiS4 is a promising NLO material in the IR field and Cd is a good choice for designing new IR NLO materials.

16.
Development ; 147(1)2020 Jan 13.
Artigo em Inglês | MEDLINE | ID: mdl-31826864

RESUMO

Cilia rotation-driven nodal flow is crucial for the left-right (L-R) break in symmetry in most vertebrates. However, the mechanism by which the flow signal is translated to asymmetric gene expression has been insufficiently addressed. Here, we show that Hedgehog (Hh) signalling is asymmetrically activated (L

17.
Mol Phylogenet Evol ; 143: 106691, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31759175

RESUMO

Chitin is a very important and widely-used biopolymer in fungi and lower metazoans, but mysteriously disappears in mammals. Recent studies reveal that at least lower vertebrates have chitin synthases (CS) and use them to synthesize endogenous chitin. Amphioxus, a basal chordate, therefore becomes critical to understand the evolution of CS, as it occupies the transitional position from invertebrates to vertebrates, and is considered as a good proxy to the chordate ancestor. Here, by exploiting multiple genome assemblies, high-depth RNA-seq data and synteny relations, we identify 11-12 CS genes for each amphioxus species. It represents the largest CS gene pool ever found in eukaryotes so far. As comparison, most metazoans have one or two CSs. Amphioxus is the only chordate that has both the very ancient type-I CS family and the more broadly distributed type-II CS family. Specifically, amphioxus has only one type-II CS but 10-11 type-I CSs, which means that amphioxus is the only metazoan with a greatly expanded type-I CS family. Further analysis suggests that the chordate ancestor have at least one type-II CS and an expanded of type-I CS family. We hypothesize that: these ancient CSs are mostly retained in amphioxus; but the whole type-I CS family was lost in urochordates and vertebrates; the type-II CS was later duplicated into two lineages in vertebrates and followed by stochastic losses, till all type-II CSs were eventually lost in birds and mammals. Finally, our expression profiling and preliminary gene knockout analysis suggest that amphioxus CSs could have highly diverse but mildly overlapping functions in various tissues and organs. Taken together, these findings not only provide insights into the evolution of chordate CSs, lay a foundation for further functional study of the chordate CSs. After all, it is mysterious that our chordate ancestor needed so many isoenzymes for chitin formation.

18.
Ecotoxicol Environ Saf ; 189: 110043, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31812821

RESUMO

Ethylene signaling was addressed, for the first time, in plant responses to nitrogen dioxide (NO2) by comparatively analyzing the performance of Arabidopsis ethylene insensitive 2 (ein2-1) with wild-type (WT) plants. Following NO2 fumigation, severe leaf wilting and chlorosis occurred in WT plants, but much less symptoms were observed in ein2-1. The activities of superoxide dismutase (SOD), peroxidase (PRX) and catalase (CAT) were 39%, 92%, and 11% higher, respectively, in ein2-1 than in WT following NO2 exposure. Although glutathione contents and the ratio of its reduced form (GSH) to oxidized form (GSSG) were decreased by NO2, an obviously alleviated degree was detected in ein2-1 relative to WT. Correspondingly, the contents of hydrogen peroxide (H2O2) and malondialdehyde (MDA), and electrolyte leakage were 25%, 24%, and 29% lower, respectively, in ein2-1 than in WT. The difference of oxidative stress between two tested genotypes was also revealed by the leaf staining regarding the production and distribution of H2O2, superoxide anion (O2˙-), and cell death. The genes involved in antioxidation or oxidation-reduction processes mostly presented a stronger expression in ein2-1 than in WT under NO2 stress. The photosynthesis-related parameters including chlorophyll and soluble sugar contents, net photosynthetic rate (Pn), and ribulose bisphosphate carboxylase/oxygenase (Rubisco) activity and gene expression, and chlorophyll fluorescence parameters were affected, generally, to a lesser degree in ein2-1 than in WT following NO2 fumigation. The enzymatic activities and gene expressions of invertases mostly displayed a higher level in ein2-1 relative to WT following NO2 fumigation. For example, the activities of cytoplasmic, cell wall and vacuolar invertases were 76%, 26%, and 26% higher, respectively, in ein2-1 than in WT. Together, these data suggest that ethylene signal insensitivity efficiently improves plant tolerance to NO2 exposure, and the possible mechanisms might be correlated with leaf antioxidative defense, photosynthesis-related processes, and sucrose metabolisms.

19.
Mol Med Rep ; 21(1): 123-130, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31746402

RESUMO

The present study aimed to investigate the effects of sevoflurane post­conditioning in a rat brain cerebral ischemia­reperfusion (I/R) model and examine its possible mechanism. Rats were randomly divided into six groups: Sham control group (Sham), I/R group, sevoflurane group (Se), Toll­like receptor­4 (TLR4) inhibitor group (Tak­242), nuclear factor (NF)­κB inhibitor group (QNZ) and Sevoflurane post­conditioning combined with TLR4­NF­κB signaling pathway inhibitor group (Se + Tak­242). Morris water maze test and tetrazolium chloride staining were used to investigate the I/R injury. The nerve cell apoptosis and autophagy in cortical tissue were detected by TUNEL and transmission electron microscopy, respectively. The expression of TLR4 protein in cortical tissue was observed by immunohistochemical staining. The expression of autophagy and apoptotic associated proteins in cortical tissues and the activity of TLR4­NF­κB signaling pathway were assayed by western blot analysis. Sevoflurane post­conditioning improved the learning and memory dysfunction caused by cerebral I/R injury. The cerebral infarction area, nerve cell apoptosis and formation of autophagic vacuoles were reduced after sevoflurane administration. The expression of light chain 3II/I, Beclin­1, Bad and Cleaved­Caspase­3 proteins were inhibited and the expression of Bcl­2 protein was upregulated after sevoflurane administration. Sevoflurane post­conditioning also inhibited the TLR4 protein and NF­κB phosphorylation, and increased inhibitor of kBα phosphorylation. The treatment effect of Tak­242 and QNZ groups were not significantly different compared with the Se group (P>0.05), and the Se + Tak­242 group had the best results. The present study demonstrated that sevoflurane post­conditioning could protect middle cerebral artery occlusion­induced brain injury rats by inhibiting autophagy and apoptosis, and that its mechanism is related to the TLR4­NF­κB signaling pathway.

20.
IEEE Trans Med Imaging ; 39(1): 188-203, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31217097

RESUMO

In this paper, we present a semi-supervised deep learning approach to accurately recover high-resolution (HR) CT images from low-resolution (LR) counterparts. Specifically, with the generative adversarial network (GAN) as the building block, we enforce the cycle-consistency in terms of the Wasserstein distance to establish a nonlinear end-to-end mapping from noisy LR input images to denoised and deblurred HR outputs. We also include the joint constraints in the loss function to facilitate structural preservation. In this process, we incorporate deep convolutional neural network (CNN), residual learning, and network in network techniques for feature extraction and restoration. In contrast to the current trend of increasing network depth and complexity to boost the imaging performance, we apply a parallel 1×1 CNN to compress the output of the hidden layer and optimize the number of layers and the number of filters for each convolutional layer. The quantitative and qualitative evaluative results demonstrate that our proposed model is accurate, efficient and robust for super-resolution (SR) image restoration from noisy LR input images. In particular, we validate our composite SR networks on three large-scale CT datasets, and obtain promising results as compared to the other state-of-the-art methods.

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