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1.
Comput Biol Med ; 168: 107727, 2024 01.
Article in English | MEDLINE | ID: mdl-38029532

ABSTRACT

Multi-objective optimization problems (MOPs) are characterized as optimization problems in which multiple conflicting objective functions are optimized simultaneously. To solve MOPs, some algorithms used machine learning models to drive the evolutionary algorithms, leading to the design of a variety of model-based evolutionary algorithms. However, model collapse occurs during the generation of candidate solutions, which results in local optima and poor diversity in model-based evolutionary algorithms. To address this problem, we propose a dual-population multi-objective evolutionary algorithm driven by Wasserstein generative adversarial network with gradient penalty (DGMOEA), where the dual-populations coordinate and cooperate to generate high-quality solutions, thus improving the performance of the evolutionary algorithm. We compare the proposed algorithm with the 7 state-of-the-art algorithms on 20 multi-objective benchmark functions. Experimental results indicate that DGMOEA achieves significant results in solving MOPs, where the metrics IGD and HV outperform the other comparative algorithms on 15 and 18 out of 20 benchmarks, respectively. Our algorithm is evaluated on the LEADS-PEP dataset containing 53 protein-peptide complexes, and the experimental results on solving the protein-peptide docking problem indicated that DGMOEA can effectively reduce the RMSD between the generated and the original peptide's 3D poses and achieve more competitive results.


Subject(s)
Algorithms , Benchmarking , Proteins , Machine Learning , Peptides
2.
Comput Biol Med ; 169: 107777, 2024 Feb.
Article in English | MEDLINE | ID: mdl-38104516

ABSTRACT

The identification of medical images is an essential task in computer-aided diagnosis, medical image retrieval and mining. Medical image data mainly include electronic health record data and gene information data, etc. Although intelligent imaging provided a good scheme for medical image analysis over traditional methods that rely on the handcrafted features, it remains challenging due to the diversity of imaging modalities and clinical pathologies. Many medical image identification methods provide a good scheme for medical image analysis. The concepts pertinent of methods, such as the machine learning, deep learning, convolutional neural networks, transfer learning, and other image processing technologies for medical image are analyzed and summarized in this paper. We reviewed these recent studies to provide a comprehensive overview of applying these methods in various medical image analysis tasks, such as object detection, image classification, image registration, segmentation, and other tasks. Especially, we emphasized the latest progress and contributions of different methods in medical image analysis, which are summarized base on different application scenarios, including classification, segmentation, detection, and image registration. In addition, the applications of different methods are summarized in different application area, such as pulmonary, brain, digital pathology, brain, skin, lung, renal, breast, neuromyelitis, vertebrae, and musculoskeletal, etc. Critical discussion of open challenges and directions for future research are finally summarized. Especially, excellent algorithms in computer vision, natural language processing, and unmanned driving will be applied to medical image recognition in the future.


Subject(s)
Diagnostic Imaging , Neural Networks, Computer , Diagnostic Imaging/methods , Algorithms , Image Processing, Computer-Assisted/methods , Machine Learning
3.
J Ovarian Res ; 16(1): 145, 2023 Jul 21.
Article in English | MEDLINE | ID: mdl-37480140

ABSTRACT

CONTEXT: Granulosa cells (GCs) that surround oocytes in mammalian reproduction play an active role in oocyte differentiation through proliferation and energy production. AIMS: This study aimed to investigate the characteristics of the energy metabolism of ovarian GCs and the influence of GCs on the early embryonic development in polycystic ovary syndrome (PCOS). METHODS: The clinical characteristics and in vitro fertilization-embryo transfer treatment outcomes of 39 patients with PCOS and 68 patients with simple tubal factor infertility who underwent controlled ovarian hyperstimulation were analyzed and summarized. The mitochondrial function and glucose metabolism level of the GCs were determined, as well as the content of oxidative stress markers in the follicular fluid (FF) of patients with and without PCOS. KEY RESULTS: When compared to the non-PCOS group, patients with PCOS had a significantly increased number of retrieved oocytes but a significantly decreased number of high-quality embryos, available embryos, and high-quality blastocyst formation (P < 0.05). Furthermore, the mitochondrial membrane potential, adenosine triphosphate level, and mitochondrial DNA (mtDNA) copy number decreased in the GCs, whereas the levels of reactive oxygen species increased (P < 0.01). The levels of malondialdehyde and 8-oxo-deoxyguanosine (8-OHdG) in the follicular fluid (FF) of the patients with PCOS were higher than those of the control group (P < 0.05), and superoxide dismutase was increased by compensation (P < 0.05). In the PCOS group, the expressions of GLUT1, LDHA, and PFKP were lower than those in the non-PCOS group, and glucose levels were higher. CONCLUSIONS: The low oocyte competence of PCOS may be associated with mitochondrial dysfunction and abnormal glycolysis. IMPLICATIONS: This research offers explanations for the possible connections influencing human ovarian folliculogenesis.


Subject(s)
Polycystic Ovary Syndrome , Pregnancy , Female , Humans , Polycystic Ovary Syndrome/metabolism , Granulosa Cells/metabolism , Embryo Transfer , Follicular Fluid/metabolism , Obesity/metabolism , Fertilization in Vitro , Energy Metabolism
4.
Zhongguo Dang Dai Er Ke Za Zhi ; 25(6): 633-638, 2023 Jun 15.
Article in Chinese | MEDLINE | ID: mdl-37382134

ABSTRACT

OBJECTIVES: To investigate the distribution characteristics of non-bacterial pathogens in community-acquired pneumonia (CAP) in children. METHODS: A total of 1 788 CAP children admitted to Shenyang Children's Hospital from December 2021 to November 2022 were selected. Multiple RT-PCR and capillary electrophoresis were used to detect 10 viral pathogens and 2 atypical pathogens, and serum antibodies of Chlamydial pneumoniae (Ch) and Mycoplasma pneumoniae (MP) were detected. The distribution characteristics of different pathogens were analyzed. RESULTS: Among the 1 788 CAP children, 1 295 children were pathogen-positive, with a positive rate of 72.43% (1 295/1 788), including a viral pathogen positive rate of 59.68% (1 067/1 788) and an atypical pathogen positive rate of 22.04% (394/1 788). The positive rates from high to low were MP, respiratory syncytial virus (RSV), influenza B virus (IVB), human metapneumovirus (HMPV), human rhinovirus (HRV), human parainfluenza virus (HPIV), influenza A virus (IVA), bocavirus (BoV), human adenovirus (HADV), Ch, and human coronavirus (HCOV). RSV and MP were the main pathogens in spring; MP had the highest positive rate in summer, followed by IVA; HMPV had the highest positive rate in autumn; IVB and RSV were the main pathogens in winter. The positive rate of MP in girls was higher than that in boys (P<0.05), and there were no significant differences in other pathogens between genders (P>0.05). The positivity rates of certain pathogens differed among age groups (P<0.05): the positivity rate of MP was highest in the >6 year-old group; the positivity rates of RSV and Ch were highest in the <1 year-old group; the positivity rates of HPIV and IVB were highest in the 1 to <3 year-old group. RSV, MP, HRV, and HMPV were the main pathogens in children with severe pneumonia, while MP was the primary pathogen in children with lobar pneumonia, and MP, IVB, HMPV, RSV, and HRV were the top 5 pathogens in acute bronchopneumonia. CONCLUSIONS: MP, RSV, IVB, HMPV, and HRV are the main pathogens of CAP in children, and there are certain differences in the positive rates of respiratory pathogens among children of different ages, genders, and seasons.


Subject(s)
Community-Acquired Infections , Pneumonia , Respiratory Syncytial Virus, Human , Humans , Child , Female , Male , Infant , Child, Preschool , Antibodies , Hospitalization , Influenza B virus , Mycoplasma pneumoniae
5.
Comput Biol Med ; 162: 107120, 2023 08.
Article in English | MEDLINE | ID: mdl-37276753

ABSTRACT

In recent years, Unet and its variants have gained astounding success in the realm of medical image processing. However, some Unet variant networks enhance their performance while increasing the number of parameters tremendously. For lightweight and performance enhancement jointly considerations, inspired by SegNeXt, we develop a medical image segmentation network model using atrous multi-scale (AMS) convolution, named AMSUnet. In particular, we construct a convolutional attention block AMS using atrous and multi-scale convolution, and redesign the downsampling encoder based on this block, called AMSE. To enhance feature fusion, we design a residual attention mechanism module (i.e., RSC) and apply it to the skip connection. Compared with existing models, our model only needs 2.62 M parameters to achieve the purpose of lightweight. According to experimental results on various datasets, the segmentation performance of the designed model is superior for small, medium, and large-scale targets. Code will be available at https://github.com/llluochen/AMSUnet.


Subject(s)
Image Processing, Computer-Assisted , Neural Networks, Computer
6.
Ann Bot ; 131(4): 723-736, 2023 04 28.
Article in English | MEDLINE | ID: mdl-36848247

ABSTRACT

BACKGROUND AND AIMS: Desert plants possess excellent water-conservation capacities to survive in extreme environments. Cuticular wax plays a pivotal role in reducing water loss through plant aerial surfaces. However, the role of cuticular wax in water retention by desert plants is poorly understood. METHODS: We investigated leaf epidermal morphology and wax composition of five desert shrubs from north-west China and characterized the wax morphology and composition for the typical xerophyte Zygophyllum xanthoxylum under salt, drought and heat treatments. Moreover, we examined leaf water loss and chlorophyll leaching of Z. xanthoxylum and analysed their relationships with wax composition under the above treatments. KEY RESULTS: The leaf epidermis of Z. xanthoxylum was densely covered by cuticular wax, whereas the other four desert shrubs had trichomes or cuticular folds in addition to cuticular wax. The total amount of cuticular wax on leaves of Z. xanthoxylum and Ammopiptanthus mongolicus was significantly higher than that of the other three shrubs. Strikingly, C31 alkane, the most abundant component, composed >71 % of total alkanes in Z. xanthoxylum, which was higher than for the other four shrubs studied here. Salt, drought and heat treatments resulted in significant increases in the amount of cuticular wax. Of these treatments, the combined drought plus 45 °C treatment led to the largest increase (107 %) in the total amount of cuticular wax, attributable primarily to an increase of 122 % in C31 alkane. Moreover, the proportion of C31 alkane within total alkanes remained >75 % in all the above treatments. Notably, the water loss and chlorophyll leaching were reduced, which was negatively correlated with C31 alkane content. CONCLUSION: Zygophyllum xanthoxylum could serve as a model desert plant for study of the function of cuticular wax in water retention because of its relatively uncomplicated leaf surface and because it accumulates C31 alkane massively to reduce cuticular permeability and resist abiotic stressors.


Subject(s)
Zanthoxylum , Zygophyllum , Zygophyllum/metabolism , Zanthoxylum/metabolism , Alkanes , Plant Leaves/metabolism , Sodium Chloride , Chlorophyll , Stress, Physiological , Water/metabolism , Waxes , Gene Expression Regulation, Plant
7.
BMC Plant Biol ; 23(1): 7, 2023 Jan 05.
Article in English | MEDLINE | ID: mdl-36600201

ABSTRACT

BACKGROUND: Heat stress has adverse effects on the growth and reproduction of plants. Zygophyllum xanthoxylum, a typical xerophyte, is a dominant species in the desert where summer temperatures are around 40 °C. However, the mechanism underlying the thermotolerance of Z. xanthoxylum remained unclear. RESULTS: Here, we characterized the acclimation of Z. xanthoxylum to heat using a combination of physiological measurements and transcriptional profiles under treatments at 40 °C and 45 °C, respectively. Strikingly, moderate high temperature (40 °C) led to an increase in photosynthetic capacity and superior plant performance, whereas severe high temperature (45 °C) was accompanied by reduced photosynthetic capacity and inhibited growth. Transcriptome profiling indicated that the differentially expressed genes (DEGs) were related to transcription factor activity, protein folding and photosynthesis under heat conditions. Furthermore, numerous genes encoding heat transcription shock factors (HSFs) and heat shock proteins (HSPs) were significantly up-regulated under heat treatments, which were correlated with thermotolerance of Z. xanthoxylum. Interestingly, the up-regulation of PSI and PSII genes and the down-regulation of chlorophyll catabolism genes likely contribute to improving plant performance of Z. xanthoxylum under moderate high temperature. CONCLUSIONS: We identified key genes associated with of thermotolerance and growth in Z. xanthoxylum, which provide significant insights into the regulatory mechanisms of thermotolerance and growth regulation in Z. xanthoxylum under high temperature conditions.


Subject(s)
Thermotolerance , Zanthoxylum , Zygophyllum , Thermotolerance/genetics , Sodium/metabolism , Zygophyllum/genetics , Zygophyllum/metabolism , Zanthoxylum/genetics , Transcriptome , Gene Expression Profiling , Heat-Shock Response/genetics , Transcription Factors/genetics , Transcription Factors/metabolism , Hot Temperature , Plant Proteins/genetics , Plant Proteins/metabolism , Gene Expression Regulation, Plant
8.
Asian J Androl ; 25(1): 132-136, 2023.
Article in English | MEDLINE | ID: mdl-35532557

ABSTRACT

A cross-sectional study was conducted to estimate the age-stratified normal levels and age-related changes in the risk predictors of benign prostatic hyperplasia (BPH) progression. A total of 4706 male participants aged 40 years or older in Zhengzhou (China) were enrolled. The values of the International Prostate Symptom Score (IPSS), prostate-specific antigen (PSA), prostate volume (PV), and postvoid residual urine volume (PVR) significantly increased with age. Nonlinear relationships between age and IPSS scores ≥8 (P for nonlinearity = 0.046), PSA level ≥1.6 ng ml-1, PV ≥31 ml, or PVR ≥39 ml (all P for nonlinearity <0.001) were observed. After the age of 61 years, the risk indicators related to BPH progression were positively correlated with age (odds ratio [OR] >1), regardless of the predictors of the IPSS score, PSA level, PV, or PVR; and the OR values increased gradually. Therefore, after the age of 61 years, the risk predictors related to BPH progression were positively correlated with age.


Subject(s)
Prostatic Hyperplasia , Humans , Male , Prostatic Hyperplasia/epidemiology , Prostatic Hyperplasia/diagnosis , Prostate-Specific Antigen , Cross-Sectional Studies , East Asian People , Risk Factors
9.
IEEE J Biomed Health Inform ; 26(8): 4238-4247, 2022 08.
Article in English | MEDLINE | ID: mdl-35476570

ABSTRACT

Internet of Things assisted healthcare services grants reliable clinical diagnosis and analysis by exploiting heterogeneous communication and infrastructure elements. Communication is enabled through point-to-point or cluster-to-point between the users and the diagnosis center. In this process, the complication is the resource sharing and diagnosis swiftness invalidating multiple resources. IoT's open and ubiquitous nature results in proactive resource sharing, resulting in delayed transmissions. This manuscript introduces the Redemptive Resource Sharing and Allocation (R2SA) scheme to address this issue. The available health data is accumulated on a first-come-first-serve basis, and the transmitting infrastructure is selected. In this process, the data-to-capacity of the available infrastructure is identified for non-redemptive resource allocation. The extremity of the capacity and unavailability of the resource is then analyzed for parallel processing and allocation. Therefore, the data accumulation and exchange rely on concurrent sharing and resource allocation processes, deferring a better accumulation ratio. The concurrent redemptive selection and sharing reduces transmission delay, improves resource allocation, and reduces transmission complexity. The entire process is managed for transfer learning, data-to-capacity validation, and concurrent recommendation. The first validation knowledge base remains the same/shared for different data accumulation and sharing intervals.


Subject(s)
Internet of Things , Communication , Delivery of Health Care , Humans
12.
Zhongguo Zhen Jiu ; 41(6): 645-50, 2021 Jun 12.
Article in Chinese | MEDLINE | ID: mdl-34085482

ABSTRACT

OBJECTIVE: To observe the effect of electroacupuncture (EA) pretreatment on hippocampal oxidative stress in aged mice with postoperative cognitive dysfunction (POCD) and explore the relevant mechanism of EA pretreatment on the improvement of learning and memory in POCD aged mice. METHODS: A total of 72 healthy male aged mice were randomized into a blank group, a model group, a medication group and an EA group, 18 mice in each one. In each group, 1-day, 3-day and 7-day subgroups were divided separately, 6 mice in each subgroup. In the EA group, "Baihui" (GV 20) and "Dazhui" (GV 14) were selected and stimulated with EA, using continuous wave (15 Hz, 1 mA), continuously for 30 min, once a day, for 5 days consecutively. In the medication group, 10% minocycline was injected intraperitoneally, 40 mg/kg, once a day, consecutively for 5 days. In the blank and the control group, intraperitoneal injection of 0.9% sodium chloride solution was given with equal dosage. Except the blank group, at the end of intervention, partial hepatectomy was conducted to establish POCD model in the rest groups. Morris water maze test was adopted to evaluate the learning and memory ability of the aged mice. ELISA was used to determine the contents of reactive oxygen species (ROS) and malondialdehyde (MDA) in the hippocampal tissue. Western blot method was applied to detect the protein expressions of superoxide dismutase 1 (SOD 1) and superoxide dismutase 2 (SOD 2) in the hippocampal tissue. RESULTS: Compared with the blank group, the percentage of platform quadrant residence time was obviously reduced in the mice in the model group (P<0.01), and those in the medication group and the EA group were larger than the model group (P<0.01). Compared with the model group, the contents of ROS were reduced in each subgroup of the medication group and the 3-day subgroup and the 7-day subgroup of the EA group separately (P<0.01, P<0.05), MDA contents were reduced in the medication group and the EA group (P<0.01, P<0.05), the protein expressions of SOD 1 and SOD 2 were all increased in each subgroup of the medication group and the 3-day subgroup and the 7-day subgroup of the EA group (P<0.05, P<0.01). Compared with the medication group, the contents of ROS and MDA in the 1-day subgroup of the EA group were increased (P<0.05), the hippocampal SOD 1 protein expression was increased in the 7-day group of the EA group (P<0.05) and the hippocampal SOD 2 protein expression was reduced in the 1-day subgroup of the EA group (P<0.05). CONCLUSION: Electroacupuncture pretreatment at "Baihui" (GV 20) and "Dazhui" (GV 14) may increase the learning and memory ability of POCD aged mice, which is probably related to the decrease of oxidative stress and the strengthening of hippocampal antioxidant capacity.


Subject(s)
Electroacupuncture , Postoperative Cognitive Complications , Animals , Hippocampus , Male , Memory , Mice , Oxidative Stress
13.
Exp Neurol ; 341: 113692, 2021 07.
Article in English | MEDLINE | ID: mdl-33727099

ABSTRACT

Triggering receptor expressed on myeloid cells-1 (TREM-1) was found to be induced in the context of subarachnoid hemorrhage (SAH) before. This study further investigates its role in the development of SAH-induced early brain injury (EBI). Firstly, rats were randomly divided into Sham and SAH groups for analysis of temporal patterns and cellular localization of TREM-1. Secondly, TREM-1 intervention was administrated to produce Sham, vehicle, antagonist and agonist groups, for analyzing TREM-1, Toll-like receptor 4 (TLR4), myeloid differentiation factor 88 (MyD88) and NF-κB expressions at 24 h post-modeling, and EBI assessment at 24 h and 72 h. Thirdly, TLR4 inhibitor (TAK-242) was exploited to produce Sham, Sham+TAK-242, SAH, and SAH + TAK-242 groups to analyze the effects of TLR4 inhibition on TREM-1 induction and EBI evaluation at 72 h. Fourthly, the relationship of soluble TREM-1 (sTREM-1) levels in cerebrospinal fluid of SAH patients with Hunt-Hess grades were explored. The results showed that TREM-1 increased in the brain after experimental SAH (eSAH) early at 6 h and peaked at 48 h, which was found to be located in microglia and endothelial cells. TREM-1 inhibition attenuated EBI associated with TLR4/MyD88/NF-κB suppression, while enhancement had the opposite effects. Contrarily, TLR4 inhibition prevented TREM-1 induction and ameliorated EBI. In addition, sTREM-1 levels in SAH patients positively correlated with Hunt-Hess grades. Overall, the present study provides new evidence that TREM-1 increases dynamically in the brain after eSAH and it is located in microglia and endothelial cells, which may aggravate EBI by interacting with TLR4 pathway. And sTREM-1 in patients might act as a monitoring biomarker of EBI, providing new insights for future studies.


Subject(s)
Brain Injuries/metabolism , Brain Injuries/pathology , Subarachnoid Hemorrhage/metabolism , Subarachnoid Hemorrhage/pathology , Triggering Receptor Expressed on Myeloid Cells-1/metabolism , Aged , Animals , Blood-Brain Barrier/metabolism , Blood-Brain Barrier/pathology , Brain/metabolism , Brain/pathology , Endothelial Cells/metabolism , Endothelial Cells/pathology , Female , Humans , Male , Microglia/metabolism , Microglia/pathology , Middle Aged , Rats , Rats, Sprague-Dawley , Time Factors
14.
Acta Pharmacol Sin ; 42(2): 264-271, 2021 Feb.
Article in English | MEDLINE | ID: mdl-32737468

ABSTRACT

Previous studies demonstrated that prolonged exposure to elevated levels of free fatty acids (FFA), especially saturated fatty acids, could lead to pancreatic ß-cell apoptosis, which plays an important role in the progression of type 2 diabetes (T2D). Diacylglycerol acyltransferase 1 (DGAT1), an enzyme that catalyzes the final step of triglyceride (TG) synthesis, has been reported as a novel target for the treatment of multiple metabolic diseases. In this study we evaluated the potential beneficial effects of DGAT1 inhibitors on pancreatic ß-cells, and further verified their antidiabetic effects in db/db mice. We showed that DGAT1 inhibitors (4a and LCQ908) at the concentration of 1 µM significantly ameliorated palmitic acid (PA)-induced apoptosis in MIN6 pancreatic ß-cells and primary cultured mouse islets; oral administration of a DGAT1 inhibitor (4a) (100 mg/kg) for 4 weeks significantly reduced the apoptosis of pancreatic islets in db/db mice. Meanwhile, 4a administration significantly decreased fasting blood glucose and TG levels, and improved glucose tolerance and insulin tolerance in db/db mice. Furthermore, we revealed that pretreatment with 4a (1 µM) significantly alleviated PA-induced intracellular lipid accumulation, endoplasmic reticulum (ER) stress, and proinflammatory responses in MIN6 cells, which might contribute to the protective effects of DGAT1 inhibitors on pancreatic ß-cells. These findings provided a better understanding of the antidiabetic effects of DGAT1 inhibitors.


Subject(s)
Diabetes Mellitus, Experimental/drug therapy , Diabetes Mellitus, Type 2/drug therapy , Diacylglycerol O-Acyltransferase/antagonists & inhibitors , Hypoglycemic Agents/pharmacology , Animals , Apoptosis/drug effects , Blood Glucose/drug effects , Cell Line , Diabetes Mellitus, Experimental/physiopathology , Diabetes Mellitus, Type 2/physiopathology , Endoplasmic Reticulum Stress/drug effects , Insulin/metabolism , Insulin-Secreting Cells/drug effects , Insulin-Secreting Cells/pathology , Islets of Langerhans/drug effects , Islets of Langerhans/pathology , Male , Mice , Mice, Inbred C57BL , Palmitic Acid/toxicity
15.
Front Immunol ; 11: 1024, 2020.
Article in English | MEDLINE | ID: mdl-32733433

ABSTRACT

The interaction between microglia and astrocytes significantly influences neuroinflammation. Microglia/astrocytes, part of the neurovascular unit (NVU), are activated by various brain insults. The local extracellular and intracellular signals determine their characteristics and switch of phenotypes. Microglia and astrocytes are activated into two polarization states: the pro-inflammatory phenotype (M1 and A1) and the anti-inflammatory phenotype (M2 and A2). During neuroinflammation, induced by stroke or lipopolysaccharides, microglia are more sensitive to pathogens, or damage; they are thus initially activated into the M1 phenotype and produce common inflammatory signals such as IL-1 and TNF-α to trigger reactive astrocytes into the A1 phenotype. These inflammatory signals can be amplified not only by the self-feedback loop of microglial activation but also by the unique anatomy structure of astrocytes. As the pathology further progresses, resulting in local environmental changes, M1-like microglia switch to the M2 phenotype, and M2 crosstalk with A2. While astrocytes communicate simultaneously with neurons and blood vessels to maintain the function of neurons and the blood-brain barrier (BBB), their subtle changes may be identified and responded by astrocytes, and possibly transferred to microglia. Although both microglia and astrocytes have different functional characteristics, they can achieve immune "optimization" through their mutual communication and cooperation in the NVU and build a cascaded immune network of amplification.


Subject(s)
Astrocytes/immunology , Brain/physiology , Microglia/immunology , Neurogenic Inflammation/immunology , Neurons/physiology , Neurovascular Coupling/physiology , Animals , Humans , Inflammation Mediators/metabolism
16.
Sci Rep ; 9(1): 15040, 2019 10 21.
Article in English | MEDLINE | ID: mdl-31636294

ABSTRACT

The XRF, XRD, polarizing microscopy and SEM-EDS were used to study the alteration mechanism of copper-bearing biotite and the leachable property of copper-bearing minerals in Mulyashy Copper Mine, Zambia. It was found that biotite can be divided into copper-bearing biotite and copper-free biotite. Some copper-bearing biotite existed in the form of monomer, and others aggregated with copper-bearing chlorite, malachite or copper-bearing limonite. The main reason for the occurrence of biotite aggregations was that copper-bearing biotite underwent two kinds of alteration mechanisms as follows: altering into copper-bearing chlorite and malachite, and altering into copper-bearing chlorite and copper-bearing limonite. The order of factors effecting the copper leaching rate of the ores in acid leaching experiments was temperature > sample size > H2SO4 concentration > leaching time > stirring speed. In addition, the copper leaching rate of copper-bearing minerals at different temperatures was in the following order: malachite, chrysocolla and pseudomalachite > copper-bearing chlorite > copper-bearing muscovite > copper-bearing biotite > copper-bearing limonite. The leachable property of biotite is closely related to its special structure.

17.
ACS Appl Mater Interfaces ; 11(35): 32097-32107, 2019 Sep 04.
Article in English | MEDLINE | ID: mdl-31408610

ABSTRACT

Kesterite Cu2ZnSn(S,Se)4 (CZTSSe) thin film is a promising material for optoelectronic devices. In this work, we fabricate Mo/CZTSSe/CdS/ZnO/ITO (ITO, indium tin oxide) heterojunction photodetectors with favorable self-powered characteristics. The photodetector exhibits exceptional high-frequency photoresponse performance whose -3 dB bandwidth and rise/decay time have reached 1 MHz and 240/340 ns, respectively. For further improvement, ultrathin Al2O3 layer prepared via atomic layer deposition (ALD) process is introduced at the Mo/CZTSSe interface. The influence of ALD-Al2O3 layer thickness and its role on the photoresponse performance are investigated in detail. The interfacial layer proved to serve as a protective layer preventing selenization of Mo electrode, resulting in the reduction of MoSe2 transition layer and the decrease of series resistance of the device. Accordingly, the -3 dB bandwidth is remarkably extended to 3.5 MHz while the rise/decay time is dramatically improved to 60/77 ns with 16 cycles of ALD-Al2O3 layer, which is 4-5 orders of magnitude faster than the other reported CZTSSe photodetectors. Simultaneously, it is revealed that the ALD-Al2O3 interfacial layer acts as an electron blocking layer which leads to the effective suppression of carrier recombination at the rear surface. Consequently, the responsivity and detectivity are enhanced in the entire range while the maximum values are up to 0.39 AW-1 and 2.04 × 1011 Jones with 8 cycles of ALD-Al2O3, respectively. Finally, the CZTSSe photodetector is successfully integrated into a visible light communication system and obtains a satisfying transfer rate of 2 Mbps. These results indicate the satisfying performance of CZTSSe-based thin film photodetectors with great potential applications for communication.

18.
Small ; 15(36): e1902135, 2019 Sep.
Article in English | MEDLINE | ID: mdl-31322829

ABSTRACT

Self-powered photodetectors (PDs) based on inorganic metal halide perovskites are regarded as promising alternatives for the next generation of photodetectors. However, uncontrollable film growth and sluggish charge extraction at interfaces directly limit the sensitivity and response speed of perovskite-based photodetectors. Herein, by assistance of an atomic layer deposition (ALD) technique, CsPbBr3 perovskite thin films with preferred orientation and enlarged grain size are obtained on predeposited interfacial modification layers. Thanks to improved film quality and double side interfacial engineering, the optimized CsPbBr3 (Al2 O3 /CsPbBr3 /TiO2 , ACT) perovskite PDs exhibit outstanding performance with ultralow dark current of 10-11 A, high detectivity of 1.88 × 1013 Jones and broad linear dynamic range (LDR) of 172.7 dB. Significantly, excellent long-term environmental stability (ambient conditions >100 d) and flexibility stability (>3000 cycles) are also achieved. The remarkable performance is credited to the synergistic effects of high carrier conductivity and collection efficiency, which is assisted by ALD modification layers. Finally, the ACT PDs are successfully integrated into a visible light communication system as a light receiver on transmitting texts, showing a bit rate as high as 100 kbps. These results open the window of high performance all-inorganic halide perovskite photodetectors and extends to rational applications for optical communication.

19.
Biosens Bioelectron ; 141: 111452, 2019 Sep 15.
Article in English | MEDLINE | ID: mdl-31252259

ABSTRACT

A stable and sensitive electrochemical acetylcholinesterase (AChE) biosensor for detection of organophosphorus pesticides (OPs) was developed by doping Au nanorods (AuNRs)@mesoporous SiO2 (MS) core-shell nanoparticles into CS/TiO2-CS (CS denotes for chitosan) immobilization matrix. AuNRs@MS core-shell nanoparticles were synthesized and characterized. The doping and the biosensor fabrication process were probed and confirmed by scanning electron microscopy and electrochemistry techniques. The doping conditions were optimized. The matrix both before and after AChE immobilization had a mesoporous nanostructure. The nanoparticles dispersed homogeneously within the matrix. The doping significantly enhanced the electro-conductivity of the TiO2-CS hydrogel, and dramatically improved the bioelectrocatalytic activity and OPs detection sensitivity of the AChE immobilized matrix. The detection linear ranges for both dichlovos (DDVP) and fenthion were from 0.018 µM (4.0 ppb) to 13.6 µM, and the limit of detection (LOD) was 5.3 nM (1.2 ppb) and 1.3 nM (0.36 ppb), respectively. The biosensor exhibited high reproducibility and accuracy in detecting OPs spiked vegetable juice samples. In addition, it exhibited very high detection stability and storage stability. The developed AChE biosensor was provided to be a promisingly applicable tool for OPs detection with high reliability, simplicity, and rapidness.


Subject(s)
Biosensing Techniques/methods , Gold/chemistry , Hydrogels/chemistry , Nanotubes/chemistry , Organophosphorus Compounds/analysis , Pesticides/analysis , Acetylcholinesterase/chemistry , Animals , Chitosan/chemistry , Electrophorus , Enzymes, Immobilized/chemistry , Fish Proteins/chemistry , Limit of Detection , Nanoparticles/chemistry , Silicon Dioxide/chemistry , Titanium/chemistry
20.
Acta Pharmacol Sin ; 40(9): 1193-1204, 2019 Sep.
Article in English | MEDLINE | ID: mdl-30833709

ABSTRACT

Gluconeogenesis is a major source of hyperglycemia in patients with type 2 diabetes mellitus (T2DM), thus targeting gluconeogenesis to suppress glucose production is a promising strategy for anti-T2DM drug discovery. In our preliminary in vitro studies, we found that a small-molecule (E)-3-(2-(quinoline-4-yl)vinyl)-1H-indol-6-ol (QVO) inhibited the hepatic glucose production (HGP) in primary hepatocytes. We further revealed that QVO suppressed hepatic gluconeogenesis involving calmodulin-dependent protein kinase kinase ß- and liver kinase B1-adenosine monophosphate-activated protein kinase (AMPK) pathways as well as AMPK-independent mitochondrial function-related signaling pathway. To evaluate QVO's anti-T2DM activity in vivo, which was impeded by the complicated synthesis route of QVO with a low yield, we designed and synthesized 4-[2-(1H-indol-3-yl)vinyl]quinoline (IVQ) as a prodrug with easier synthesis route and higher yield. IVQ did not inhibit the HGP in primary hepatocytes in vitro. Pharmacokinetic studies demonstrated that IVQ was quickly converted to QVO in mice and rats following administration. In both db/db and ob/ob mice, oral administration of IVQ hydrochloride (IVQ-HCl) (23 and 46 mg/kg every day, for 5 weeks) ameliorated hyperglycemia, and suppressed hepatic gluconeogenesis and activated AMPK signaling pathway in the liver tissues. Furthermore, IVQ caused neither cardiovascular system dysfunction nor genotoxicity. The good druggability of IVQ has highlighted its potential in the treatment of T2DM and the prodrug design for anti-T2DM drug development.


Subject(s)
Diabetes Mellitus, Type 2/drug therapy , Gluconeogenesis/drug effects , Hypoglycemic Agents/therapeutic use , Indoles/therapeutic use , Prodrugs/therapeutic use , Quinolines/therapeutic use , AMP-Activated Protein Kinases/metabolism , Animals , Diabetes Mellitus, Experimental/drug therapy , Electron Transport Complex I/antagonists & inhibitors , Electron Transport Complex III/antagonists & inhibitors , Enzyme Activators/therapeutic use , Enzyme Activators/toxicity , Enzyme Inhibitors/therapeutic use , Enzyme Inhibitors/toxicity , Glucose-6-Phosphatase/antagonists & inhibitors , Hepatocytes/drug effects , Hypoglycemic Agents/toxicity , Indoles/toxicity , Liver/drug effects , Male , Mice, Inbred C57BL , Mitochondria/drug effects , Phosphoenolpyruvate Carboxykinase (GTP)/antagonists & inhibitors , Prodrugs/toxicity , Quinolines/toxicity , Signal Transduction/drug effects
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