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1.
Med Sci Monit ; 26: e921831, 2020 Jul 05.
Artigo em Inglês | MEDLINE | ID: mdl-32623439

RESUMO

BACKGROUND Insomnia seriously affects people's health and quality of life. Short-term use of Western drugs may also be harmful. Traditional Chinese medicine has been widely used to treat diseases in world. Therefore, this paper aims to study the therapeutic effect of berberine based on the insomnious rat model. MATERIAL AND METHODS The insomnia rat model was established by intragastric administration of caffeine and parachlorophenylalanine (PCPA). Berberine and diazepam were used to treat the established insomnia rats. Then, the pathological changes of insomnia rats were detected. In addition, transcriptome sequencing and data analysis were carried out using rat hippocampus. The expression of key genes was verified by quantitative polymerase chain reaction and western blot. RESULTS After 7 days of intragastric administration of berberine, the body weight, memory, and sleep quality of insomnia rats were significantly improved. The key roles of Erbb4, Erbb2, Ar, and Grin2a in berberine treatment were identified. Through the analysis of biological functions and signaling pathways, berberine was shown to play a salutary role through nervous system development and ErbB signaling pathway. Gene-set enrichment analysis (GSEA) results showed that berberine treatment affected more metabolic pathways. Compared with diazepam, berberine can play a faster role, and also improve the overall health level of insomnia rats. CONCLUSIONS These results suggest that berberine can alleviate insomnia in rats through a neuroprotective effect and improved metabolic level. Berberine has great potential in treatment of insomnia and might have better clinical significance.

2.
Nat Nanotechnol ; 2020 Jun 29.
Artigo em Inglês | MEDLINE | ID: mdl-32601451

RESUMO

In the nervous system, dendrites, branches of neurons that transmit signals between synapses and soma, play a critical role in processing functions, such as nonlinear integration of postsynaptic signals. The lack of these critical functions in artificial neural networks compromises their performance, for example in terms of flexibility, energy efficiency and the ability to handle complex tasks. Here, by developing artificial dendrites, we experimentally demonstrate a complete neural network fully integrated with synapses, dendrites and soma, implemented using scalable memristor devices. We perform a digit recognition task and simulate a multilayer network using experimentally derived device characteristics. The power consumption is more than three orders of magnitude lower than that of a central processing unit and 70 times lower than that of a typical application-specific integrated circuit chip. This network, equipped with functional dendrites, shows the potential of substantial overall performance improvement, for example by extracting critical information from a noisy background with significantly reduced power consumption and enhanced accuracy.

3.
Protein Expr Purif ; 174: 105658, 2020 Apr 28.
Artigo em Inglês | MEDLINE | ID: mdl-32360598

RESUMO

The recombinant multi-epitope vaccine called VBP3 is designed to suppress tumor growth and angiogenesis through targeting both basic fibroblast growth factor (bFGF) and vascular endothelial growth factor A (VEGFA). We are aiming to produce VBP3 vaccine in a large scale and provide sufficient protein for pre-clinical study. High cost and potential toxicity are severe limitations of IPTG and we investigated whether lactose can mediate VBP3 induction. Firstly, we identified the biological characteristics and established a culture bank of VBP3 strains. The best-performing strains were selected and the fermentation mode of medium, bacterial growth and protein expression were optimized in shake flasks. We scaled up the VBP3 production in 10 L bioreactor using lactose as inducer and the protein yield was comparable with IPTG induction. Next, the target protein was purified by nickel-nitrilotriacetic acid (Ni-NTA) affinity chromatography, with a SDS-PAGE purity over 90%. Further, the purified VBP3 vaccine was subcutaneously injected in BALB/c mice and elicited high-titer anti-bFGF (1:32,000) and anti-VEGFA (1:4000) antibodies. Take together, lactose was an applicable inducer for VBP3 production and the eligible product of VBP3 was harvested in the large-scale fermentation, supporting the industrial production and pre-clinical study in the future. The VBP3 vaccine with superior immunogenicity might be used as a potential therapeutic vaccine for tumor treatment.

5.
Phytochemistry ; 176: 112399, 2020 May 11.
Artigo em Inglês | MEDLINE | ID: mdl-32408190

RESUMO

Black aspergilli are distributed worldwide and represent one of the most prolific sources of metabolites with biomedical and agrochemical interests. However, due to their similar morphological characteristics and insufficient molecular identification, the taxonomic classification of black aspergilli remains ill-defined. The production of specialised metabolites is often unique for species among black aspergilli and could be used as diagnostic chemical markers for species identification. In this study, chemical investigation of Aspergillus tubingensis OUCMBIII 143291 led to the discovery of the diagnostic chemical marker asperazine, a complex diketopiperazine heterodimer, as well as two previously undescribed analogues, asperazine B and C. In addition, an undescribed 2-benzylpyridin-4(1H)-one-containing amide, pestalamide D, along with four known related metabolites were isolated. Their chemical structures, including their absolute configurations, were established on the basis of comprehensive spectral analysis and chiral HPLC analysis of the acidic hydrolysates. Asperazines B and C can serve as potential chemical markers for distinguishing A. tubingensis from A. niger, two representative species of black aspergilli that are usually incorrectly identified. Moreover, the isolated compounds were evaluated for their antifungal activity against eight phytopathogenic fungi including Alternaria alternata, A. brassicae, Botrytis cinerea, Colletotrichum lagenarium, Fusarium oxysporum, Gaeumannomyces graminis, Penicillium digitatum, and Valsa mali. Pestalamide D exhibited significant activities against B. cinerea, C. lagenarium, and V. mali, with MIC values of 4, 8, and 8 µg/mL, respectively, compared with the positive controls carbendazim (MICs = 8, 4, and 4 µg/mL) and prochloraz (MICs = 8, 8, and 4 µg/mL). The results of this study reveal two additional chemical markers and provide a powerful tool for the rapid identification of black aspergilli.

6.
Cell Death Dis ; 11(5): 345, 2020 May 11.
Artigo em Inglês | MEDLINE | ID: mdl-32393810

RESUMO

miRNAs have emerged as a pivotal component of gene regulatory networks, mediating cytokines secretion, cell cycle, and differentiation regulation. However, how miRNAs collaborate with transcription factors and downstream effector proteins that determine the fate of ovarian cancer cells remains to be understood, especially regarding to mechanism of tumor angiogenesis regulation. Based on the qRT-PCR and IHC analysis, we found that miR-6086 was maintained a very low level both in ovarian cancer cell lines and tissues. Further, we identified OC2 and EGFL6 as the direct targets of miR-6086 by luciferase assay and we observed an inverse relationship between the expression of miR-6086 and the OC2/VEGFA/EGFL6 axis. The Western blotting analysis suggested that OC2 could directly upregulate VEGFA and indirectly up-regulate EGFL6 through VEGFA. Moreover, miR-6086 could indirectly downregulate VEGFA through OC2. In addition, miR-6086, siOC2 and siEGFL6 could negatively regulate the tumor growth and angiogenesis of ovarian cancer (Skov3) in the animal studies, with the inhibition rates of 77.07%, 69.89%, and 73.62%, respectively (**p < 0.01). Moreover, the tumor cell proliferation, migration, and invasion of ovarian cancer cell lines (Caov3 and Skov3) and vascular formation (HUVECs) were significantly suppressed in vitro, by decreasing the AKT/MAPK pathways (*p < 0.05). Taken together, our results reveal that miR-6086 can suppress the angiogenesis networks in ovarian cancer by down-regulating the OC2/VEGFA/EGFL6 axis, directly or indirectly, which may provide potential targets for tumor therapeutics.

7.
J Craniomaxillofac Surg ; 48(6): 569-573, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32340907

RESUMO

PURPOSE: In the treatment of philtral ridge deficiency in cleft lip patients, optimal results are difficult to obtain due to visible scarring following surgery. The purpose of this article is to introduce a novel strategy for philtrum reconstruction along with an evaluation of postoperative outcomes of this technique. METHOD: All patients with a deficiency of the philtrum underwent reconstruction of the philtral ridge and upper lip using an orbicularis oris muscle flap with a specific re-suturing technique in our study. The convexity of the philtral ridge was evaluated pre- and postoperatively at rest and while puckering using patient photography as well as three-dimensional simulation technology. Postoperative outcomes and complications were assessed during follow-up, including a patient satisfaction survey. RESULTS: Thirty cleft lip patients underwent treatment in this study using a specific orbicularis oris muscle re-suturing technique. The average age of the 13 male and 17 female patients was 31.5 years. The follow-up period ranged from 6 months to 3.5 years with an average of 10.3 months. Postoperative results showed an aesthetic reconstructed philtral ridge with stable outcome. Complications included acute infection (1 case) and temporary stiffness of smile (3 cases). No systemic complications occurred. All patients were satisfied with their results, and none required further surgery. CONCLUSION: We propose a simple, effective, and reproducible technique involving an orbicularis oris muscle flap for the creation of the philtral column in secondary cleft lip deformity. Our approach allowed aesthetically pleasing and stable outcomes. Although the short-term results of the philtrum reconstruction seem to be adequate there is no information on the long-term situation, and therefore no general recommendation to adopt this method can be given.

8.
Environ Sci Technol ; 54(11): 6761-6770, 2020 Jun 02.
Artigo em Inglês | MEDLINE | ID: mdl-32250111

RESUMO

Ferrihydrite nanoparticles (Fh NPs) are ubiquitous in natural environments. However, their colloidal stability, and fate and transport behavior are difficult to predict in the presence of heterogeneous natural organic matter (NOM) mixtures. Here, we investigated the adsorption and aggregation behavior of Fh NPs exposed to NOM fractions with different molecular weights (MW). The NOM fraction with MW < 3 kDa destabilized the NPs, resulting in accelerated aggregation even at high C/Fe mass ratios, whereas higher MW NOM fractions imparted better colloidal stability with increasing MW and C/Fe ratio. Despite differences in the functional group composition of the bulk (dissolved) NOM fractions, all NOM fractions produced similar adsorbed layer compositions on the NPs, suggesting minimal contribution of chemical properties to the distinctive aggregation behavior. Rather, the higher adsorbed mass and larger size of the higher MW fractions were key factors in stabilizing the NPs through steric repulsion, whereas the lowest MW fraction had low adsorbed mass and was unable to counter electrostatic patch-charge attraction when the NPs are positively charged. This mechanistic understanding helps us predict the transport and fate of Fh NPs and the associated contaminants in natural environments with varying NOM compositions.

9.
JMIR Med Inform ; 8(4): e17642, 2020 Apr 23.
Artigo em Inglês | MEDLINE | ID: mdl-32324148

RESUMO

BACKGROUND: Health education emerged as an important intervention for improving the awareness and self-management abilities of chronic disease patients. The development of information technologies has changed the form of patient educational materials from traditional paper materials to electronic materials. To date, the amount of patient educational materials on the internet is tremendous, with variable quality, which makes it hard to identify the most valuable materials by individuals lacking medical backgrounds. OBJECTIVE: The aim of this study was to develop a health recommender system to provide appropriate educational materials for chronic disease patients in China and evaluate the effect of this system. METHODS: A knowledge-based recommender system was implemented using ontology and several natural language processing (NLP) techniques. The development process was divided into 3 stages. In stage 1, an ontology was constructed to describe patient characteristics contained in the data. In stage 2, an algorithm was designed and implemented to generate recommendations based on the ontology. Patient data and educational materials were mapped to the ontology and converted into vectors of the same length, and then recommendations were generated according to similarity between these vectors. In stage 3, the ontology and algorithm were incorporated into an mHealth system for practical use. Keyword extraction algorithms and pretrained word embeddings were used to preprocess educational materials. Three strategies were proposed to improve the performance of keyword extraction. System evaluation was based on a manually assembled test collection for 50 patients and 100 educational documents. Recommendation performance was assessed using the macro precision of top-ranked documents and the overall mean average precision (MAP). RESULTS: The constructed ontology contained 40 classes, 31 object properties, 67 data properties, and 32 individuals. A total of 80 SWRL rules were defined to implement the semantic logic of mapping patient original data to the ontology vector space. The recommender system was implemented as a separate Web service connected with patients' smartphones. According to the evaluation results, our system can achieve a macro precision up to 0.970 for the top 1 recommendation and an overall MAP score up to 0.628. CONCLUSIONS: This study demonstrated that a knowledge-based health recommender system has the potential to accurately recommend educational materials to chronic disease patients. Traditional NLP techniques combined with improvement strategies for specific language and domain proved to be effective for improving system performance. One direction for future work is to explore the effect of such systems from the perspective of patients in a practical setting.

10.
JMIR Mhealth Uhealth ; 8(2): e14466, 2020 02 25.
Artigo em Inglês | MEDLINE | ID: mdl-32130161

RESUMO

BACKGROUND: Hypertension is a lifestyle-induced chronic disease that threatens the lives of patients. Control of hypertension requires patients to follow self-management regimes; unfortunately, however, patient compliance with hypertension self-management is low, especially in developing countries. Improvement of patient compliance is premised on meeting patient needs. Mobile health apps are becoming increasingly popular for self-management of chronic diseases. However, few mobile apps have been designed to meet patient needs for hypertension self-management. OBJECTIVE: The goal of this study was to develop a mobile health app to improve patient compliance with hypertension self-management and evaluate the effectiveness of the app in terms of patient compliance. METHODS: Clustering methods based on questionnaire responses were used to group patients. Qualitative interviews were conducted to identify the needs of different groups. In stage 2, several functional modules were designed to meet the needs of different groups based on the results from stage 1. In stage 3, prototypes of functional modules were designed and implemented as a real app. Stage 4 was the deployment process, in which we conducted a pilot study to investigate patient compliance after using the app. Patient compliance was calculated through the frequency with which they took blood pressure measurements. In addition, qualitative interviews were conducted to learn the underlying reasons for the compliance. RESULTS: In stage 1, patients were divided into 3 groups based on 82 valid questionnaire responses. Eighteen patients from the different groups (7, 5, and 6 patients) were interviewed, and the needs of the groups were summarized as follows: improve self-management ability, enhance self-management motivation, and receive self-management support. In stages 2 and 3, 6 functional modules were designed and implemented based on specified needs, and the usability of the app was improved through usability tests. In stage 4, 143 patients were recruited to use different versions of the app for 2 months. Results show that patient compliance improved as functional modules were added (P<.001) and was maintained at a high level (rate of 0.73). Interview results from 32 patients show that the design of the app met different needs; thus, patients were more compliant with it. CONCLUSIONS: This study developed a mobile health app for hypertension self-management using the goal-directed design method. The app proved to be effective for improving patient compliance with hypertension self-management.

11.
Transl Neurosci ; 10: 235-240, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31497320

RESUMO

Objective: Resveratrol(RES) is a natural polyphenol which possesses an anti-depressant effect. However, the mechanisms of its anti-depressant effect remain unclear. The aim of the study is to investigate the potential mechanisms in the neuro-protective efficiency in the corticosterone-induced pheochromacytoma 12 (PC12) cells. Methods: PC12 cells were treated with 200 µM of corticosterone in the absence or presence of different concentrations of RES for 24 h. Then, cell viability was measured by Cell Counting Kit-8 assay. Apoptosis of PC12 cells was measured by Annexin V-FITC and Propidium iodide (PI) labelling. The expression of apoptosis-related proteins including Bax, Bcl-2, caspase-3 was determined by western blotting. Results: The results showed that treatment with 200 µM of corticosterone induced cytotoxicity in PC12 cells. However, different concentrations of RES (2.5µmol/L, 5µmol/L and 10 µmol/L) significantly increased the cell viability, suppressed the apoptosis of PC12 cells, down-regulated Bax and caspase-3 protein expression, and up-regulated Bcl-2 protein expression, compared to the model group (p<0.05). Conclusion: Resveratrol has a protective effect on corticosterone-induced neurotoxicity in PC12 cells, which may be related to the apoptosis via inhibition of apoptosis-related proteins and displays the antidepressant-like effect.

12.
Nature ; 572(7767): 106-111, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-31367028

RESUMO

There are two general approaches to developing artificial general intelligence (AGI)1: computer-science-oriented and neuroscience-oriented. Because of the fundamental differences in their formulations and coding schemes, these two approaches rely on distinct and incompatible platforms2-8, retarding the development of AGI. A general platform that could support the prevailing computer-science-based artificial neural networks as well as neuroscience-inspired models and algorithms is highly desirable. Here we present the Tianjic chip, which integrates the two approaches to provide a hybrid, synergistic platform. The Tianjic chip adopts a many-core architecture, reconfigurable building blocks and a streamlined dataflow with hybrid coding schemes, and can not only accommodate computer-science-based machine-learning algorithms, but also easily implement brain-inspired circuits and several coding schemes. Using just one chip, we demonstrate the simultaneous processing of versatile algorithms and models in an unmanned bicycle system, realizing real-time object detection, tracking, voice control, obstacle avoidance and balance control. Our study is expected to stimulate AGI development by paving the way to more generalized hardware platforms.

13.
J Hazard Mater ; 379: 120570, 2019 11 05.
Artigo em Inglês | MEDLINE | ID: mdl-31382082

RESUMO

To enhance the long-term immobilization of radioactive wastes, ferrihydrite nanoparticles were incorporated into cementitious materials. The effects of ferrihydrite nanoparticles on the physicochemical and mechanical properties of cementitious materials and the immobilization of uranium (U), strontium (Sr) and cesium (Cs) were investigated. Adding ferrihydrite nanoparticles at 0.65%, 1.30%, 3.90% and 6.50% of cement weight slightly improved compressive strength by 5-11%, but dramatically reduced U leaching by 50-57%. The enhanced U immobilization was attributed to the strong adsorption of U by ferrihydrite nanoparticles, and the structural incorporation of U into hematite formed during ferrihydrite recrystallization. Although ferrihydrite nanoparticles had weaker effect than hematite nanoparticles on improving cement hydration and reducing permeability, they exhibit stronger U immobilization capacity. In contrast, incorporating ferrihydrite nanoparticles into cementitious materials had no significant effects on Cs and Sr leaching and no detectable adsorption of Sr and Cs. This study elucidated the fundamental differences in the interactions between ferrihydrite nanoparticles and U, Sr or Cs within cementitious systems that led to the distinctive immobilization mechanisms for these radionuclides. It generated new mechanistic understandings of U, Sr and Cs leaching from cementitious barriers modified by Fe-based nanoparticles, and proposed a new approach for enhancing long-term immobilization of U.

14.
Front Neurosci ; 13: 650, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31333397

RESUMO

Development of computer science has led to the blooming of artificial intelligence (AI), and neural networks are the core of AI research. Although mainstream neural networks have done well in the fields of image processing and speech recognition, they do not perform well in models aimed at understanding contextual information. In our opinion, the reason for this is that the essence of building a neural network through parameter training is to fit the data to the statistical law through parameter training. Since the neural network built using this approach does not possess memory ability, it cannot reflect the relationship between data with respect to the causality. Biological memory is fundamentally different from the current mainstream digital memory in terms of the storage method. The information stored in digital memory is converted to binary code and written in separate storage units. This physical isolation destroys the correlation of information. Therefore, the information stored in digital memory does not have the recall or association functions of biological memory which can present causality. In this paper, we present the results of our preliminary effort at constructing an associative memory system based on a spiking neural network. We broke the neural network building process into two phases: the Structure Formation Phase and the Parameter Training Phase. The Structure Formation Phase applies a learning method based on Hebb's rule to provoke neurons in the memory layer growing new synapses to connect to neighbor neurons as a response to the specific input spiking sequences fed to the neural network. The aim of this phase is to train the neural network to memorize the specific input spiking sequences. During the Parameter Training Phase, STDP and reinforcement learning are employed to optimize the weight of synapses and thus to find a way to let the neural network recall the memorized specific input spiking sequences. The results show that our memory neural network could memorize different targets and could recall the images it had memorized.

15.
Chemosphere ; 234: 822-829, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31247492

RESUMO

Mercury is one of the 10 toxic chemicals with major public health concerns. Continuous exposure to low levels of heavy metals including mercury is related to renal injury, especially in children. This study investigated the possible molecular mechanism of inorganic mercury-induced kidney injury. Twenty eight Kunming mice were divided into four groups (n = 7), and treated with 0, 20, 40, 80 mg/L mercuric chloride (HgCl2) in drinking water for 16 weeks respectively. All the HgCl2 exposure mice displayed different degrees of renal injury, which was diagnosed by hematoxylin and eosin stain, biochemical analysis, and ultrastructure examination. The treatment of HgCl2 inhibited the silent information regulator two ortholog 1 (Sirt1)/peroxisome proliferator-activated receptor-γ coactivator-1α (PGC-1α) signaling pathway and resulted the disorder of mitochondrial dynamics, as evidenced by the increasing expression of dynamin-related protein 1 and decreasing expression of mitofusin 2. Meanwhile, HgCl2 inhibited the nuclear factor erythroid 2-related factor 2 (Nrf2) axis. The abnormality of mitochondrial dynamics and the suppression of Nrf2 axis exacerbated oxidative stress, and then induced cell apoptosis. These findings demonstrated that the disorder of mitochondrial dynamics induced by HgCl2 activated oxidative stress, and further resulted in renal apoptosis through inhibiting the Sirt1/PGC-1α signaling pathway and the Nrf2 axis.


Assuntos
Apoptose , Rim/lesões , Cloreto de Mercúrio/toxicidade , Dinâmica Mitocondrial/efeitos dos fármacos , Estresse Oxidativo , Animais , Apoptose/efeitos dos fármacos , Relação Dose-Resposta a Droga , Dinaminas/metabolismo , GTP Fosfo-Hidrolases/metabolismo , Rim/efeitos dos fármacos , Rim/metabolismo , Camundongos , Fator 2 Relacionado a NF-E2 , Estresse Oxidativo/efeitos dos fármacos , Coativador 1-alfa do Receptor gama Ativado por Proliferador de Peroxissomo/metabolismo , Transdução de Sinais/efeitos dos fármacos , Sirtuína 1/metabolismo
16.
Proc Natl Acad Sci U S A ; 116(27): 13221-13226, 2019 07 02.
Artigo em Inglês | MEDLINE | ID: mdl-31113880

RESUMO

Sr-bearing marine barite [(Ba x , Sr1-x )SO4] cycling has been widely used to reconstruct geochemical evolutions of paleoenvironments. However, an understanding of barite precipitation in the ocean, which is globally undersaturated with respect to barite, is missing. Moreover, the reason for the occurrence of higher Sr content in marine barites than expected for classical crystal growth processes remains unknown. Field data analyses suggested that organic molecules may regulate the formation and composition of marine barites; however, the specific organic-mineral interactions are unclear. Using in situ grazing incidence small-angle X-ray scattering (GISAXS), size and total volume evolutions of barite precipitates on organic films were characterized. The results show that barite forms on organic films from undersaturated solutions. Moreover, from a single supersaturated solution with respect to barite, Sr-rich barite nanoparticles formed on organics, while micrometer-size Sr-poor barites formed in bulk solutions. Ion adsorption experiments showed that organic films can enrich cation concentrations in the adjacent solution, thus increasing the local supersaturation and promoting barite nucleation on organic films, even when the bulk solution was undersaturated. The Sr enrichment in barites formed on organic films was found to be controlled by solid-solution nucleation rates; instead, the Sr-poor barite formation in bulk solution was found to be controlled by solid-solution growth rates. This study provides a mechanistic explanation for Sr-rich marine barite formation and offers insights for understanding and controlling the compositions of solid solutions by separately tuning their nucleation and growth rates via the unique chemistry of solution-organic interfaces.

17.
Chembiochem ; 20(21): 2743-2746, 2019 11 04.
Artigo em Inglês | MEDLINE | ID: mdl-31100196

RESUMO

Stimuli responsivity has been extensively pursued in dynamic DNA nanotechnology, due to its incredible application potentials. Among diverse dynamic systems, redox-responsive DNA assembly holds great promise for broad applications, especially considering that redox processes widely exist in various physiological environments. However, only a few studies have been reported on redox-sensitive dynamic DNA assembly. Albeit ingenious, most of these studies are either dependent on the DNA sequence or involve chemical modification. Herein, a facile and universal mechanism to realize redox-responsive self-assembly of DNA nanocages (tetrahedron and cube) driven by the interconversion between cystamine and cysteamine toward dynamic DNA nanotechnology is reported.

18.
PLoS One ; 14(2): e0212368, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30794587

RESUMO

It is evident through biology research that, biological neural network could be implemented through two means: by congenital heredity, or by posteriority learning. However, traditionally, artificial neural network, especially the Deep learning Neural Networks (DNNs) are implemented only through exhaustive training and learning. Fixed structure is built, and then parameters are trained through huge amount of data. In this way, there are a lot of redundancies in the implemented artificial neural network. This redundancy not only requires more effort to train the network, but also costs more computing resources when used. In this paper, we proposed a bionic way to implement artificial neural network through construction rather than training and learning. The hierarchy of the neural network is designed according to analysis of the required functionality, and then module design is carried out to form each hierarchy. We choose the Drosophila's visual neural network as a test case to verify our method's validation. The results show that the bionic artificial neural network built through our method could work as a bionic compound eye, which can achieve the detection of the object and their movement, and the results are better on some properties, compared with the Drosophila's biological compound eyes.


Assuntos
Inteligência Artificial , Biônica , Drosophila melanogaster/fisiologia , Rede Nervosa/fisiologia , Redes Neurais de Computação , Vias Visuais/fisiologia , Percepção Visual/fisiologia , Algoritmos , Animais , Cor , Aprendizado de Máquina , Movimento , Reconhecimento Automatizado de Padrão
19.
J Biochem ; 165(6): 487-495, 2019 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-30597085

RESUMO

The human fibroblast growth factor-2 (FGF-2) highly expressed in tumours is an important factor to promote tumour angiogenesis and lymphangiogenesis. A disulphide-stabilized diabody (ds-Diabody) could specifically target FGF-2 and show its advantages in inhibition of tumour angiogenesis and growth. It is very important for antibody drugs to confirm the fine epitope. Here, theoretical structure models of FGF-2 and antibody were built by homology modelling. The amino acid residues in the interaction interface of antigen and antibody were analysed by molecular docking. The potential epitope was predicted by homology modelling and molecular docking of antigen-antibody and site-directed mutation assays of alanine scanning. The predicted epitope was verified by antigen mutagenesis and enzyme-linked immunosorbent assay (ELISA). The epitope mapping assay showed that the epitope of ds-Diabody against FGF-2 was defined by the discontinuous sites including six amino acid residues (P23, Q65, R69, G70, Y82 and R118). The results showed that the epitope was localized in the interaction interface of FGF-2 and ds-Diabody. The fine epitope mapping provided the important information for understanding the inhibition activity of ds-Diabody against FGF-2 and helping in the further development of ds-Diabody against FGF-2 as a potentially promising antibody drug for future cancer therapy.


Assuntos
Anticorpos Biespecíficos/imunologia , Anticorpos Biespecíficos/farmacologia , Dissulfetos/química , Mapeamento de Epitopos , Fator 2 de Crescimento de Fibroblastos/antagonistas & inibidores , Fator 2 de Crescimento de Fibroblastos/imunologia , Neoplasias/tratamento farmacológico , Anticorpos Biespecíficos/química , Anticorpos Biespecíficos/uso terapêutico , Reações Antígeno-Anticorpo , Proliferação de Células/efeitos dos fármacos , Ensaio de Imunoadsorção Enzimática , Fator 2 de Crescimento de Fibroblastos/genética , Células HEK293 , Humanos , Modelos Moleculares , Mutagênese Sítio-Dirigida , Neoplasias/imunologia , Neoplasias/patologia
20.
J Nurs Manag ; 27(2): 320-329, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30295970

RESUMO

AIM: To investigate nursing work patterns in a neurology department in a Chinese hospital. BACKGROUND: Knowledge of nursing work patterns is important for nursing management and work design, and for the evaluation of organizational process change associated with the introduction of an innovation. METHODS: A time-and-motion method was used to observe 14 registered nurses' (RNs') work patterns in a neurology department in a Chinese hospital. RESULTS: There were 147 hr of observation. Overall, the most time-consuming activities were verbal communication (28.5%) and documentation (28.3%), followed by indirect care (14.6%) and direct care (14%). Compared to support RNs, charge RNs spent 20% more time on documentation and 11% more time on verbal communication. Two-thirds of the observed activities had a duration of less than 40 s. CONCLUSIONS: Communication, in verbal and written forms, consumed more than half of the nursing time. Conversely, nurses only spent about a quarter of their worktime on preparation for care provision and direct care provision. This reflects the significant role and resource-consuming nature of communication to provide safe and quality care. IMPLICATIONS FOR NURSING MANAGEMENT: Communication methods need to be enhanced to improve nursing productivity. This may be achieved through the introduction of more effective nursing documentation methods.


Assuntos
Eficiência , Neurologia/métodos , Carga de Trabalho/normas , China , Hospitais , Humanos , Relações Interprofissionais , Neurologia/normas , Qualidade da Assistência à Saúde/normas , Estudos de Tempo e Movimento , Carga de Trabalho/psicologia
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