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1.
Int J Mol Sci ; 25(11)2024 May 29.
Artigo em Inglês | MEDLINE | ID: mdl-38892123

RESUMO

DNA methylation is an important way to regulate gene expression in eukaryotes. In order to reveal the role of DNA methylation in the regulation of germ cell-specific piwi gene expression during spermatogenesis of Japanese flounder (Paralichthys olivaceus), the expression profiles of piwil1 (piwi-like 1) and piwil2 (piwi-like 2) genes in the gonads of female, male, and sex-reversed pseudo-male P. olivaceus were analyzed, and the dynamic of DNA methylation was investigated. As a result, piwil1 and piwil2 genes were highly expressed in the testis of both male and pseudo-male P. olivaceus, with significant variation among male individuals. The DNA methylation levels in the promoter regions of both piwil1 and piwil2 were negatively correlated with their expression levels, which may contribute to the transcriptional regulation of piwi genes during spermatogenesis. There was also sperm quality variation among male P. olivaceus, and the sperm curvilinear velocity was positively correlated with the expression of both piwil1 and piwil2 genes. These results indicated that the DNA methylation in piwil1 and piwil2 promoter regions may affect the initiation of piwi gene transcription, thereby regulating gene expression and further affecting the spermatogenesis process and gamete quality in P. olivaceus.


Assuntos
Proteínas Argonautas , Metilação de DNA , Linguado , Espermatogênese , Espermatozoides , Animais , Masculino , Proteínas Argonautas/genética , Proteínas Argonautas/metabolismo , Linguado/genética , Linguado/metabolismo , Espermatozoides/metabolismo , Espermatogênese/genética , Feminino , Regiões Promotoras Genéticas , Testículo/metabolismo , Regulação da Expressão Gênica , Proteínas de Peixes/genética , Proteínas de Peixes/metabolismo
2.
Environ Sci Pollut Res Int ; 31(17): 25273-25286, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38467998

RESUMO

The poor conductivity, poor stability, and agglomeration of iron-based metal organic framework MIL-88A(Fe) limit its application as persulfate (PS) activator in water purification. Herein, MXene-supported MIL-88A(Fe) composites (M88A/MX) were synthesized to enhance its adsorption and catalytic capability for tetracycline (TC) removal. Scanning electron microscope (SEM), X-ray diffractometer (XRD), Fourier transform infrared spectrometer (FT-IR), and X-ray photoelectron spectroscopy (XPS) were used to characterize prepared materials, confirming the successful attachment of MIL-88A(Fe) to the surface of MXene. M88A/MX-0.2 composites, prepared with 0.2 g MXene addition, exhibit optimal degradation efficiency, reaching 98% under conditions of 0.2 g/L M88A/MX-0.2, 1.0 mM PS, 20 ppm TC, and pH 5. The degradation rate constants of M88A/MX-0.2 were 0.03217 min-1, which was much higher than that of MIL-88A(Fe) (0.00159 min-1) and MXene (0.00626 min-1). The removal effects of reaction parameters, such as dosage of M88A/MX-0.2 and PS; initial solution pH; and the presence of the common co-existing constituents (humic acid and the inorganic anions) were investigated in detail. Additionally, the reuse of M88A/MX-0.2 showed that the composites had good cycling stability by recurrent experiments. The results of electron paramagnetic resonance (EPR) and quenching experiments indicated that ·OH, ·SO4-, and ·O2- were involved in the M88A/MX-0.2/PS system where persulfate oxidation process was activated with prepared M88A/MX-0.2. In addition, the intermediates of photocatalytic degradation were determined by HPLC-MS, and the possible degradation pathways of the target molecules were inferred. This study offered a new avenue for sulfate-based degradation of Fe-based metal organic framework.


Assuntos
Estruturas Metalorgânicas , Nitritos , Elementos de Transição , Estruturas Metalorgânicas/química , Espectroscopia de Infravermelho com Transformada de Fourier , Tetraciclina , Antibacterianos
3.
Acta Radiol ; 64(3): 1175-1183, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-35765198

RESUMO

BACKGROUND: Prior studies have detected topological changes of brain functional networks in patients with acute mild traumatic brain injury (mTBI). However, the alterations of dynamic topological characteristics in mTBI have been scarcely elucidated. PURPOSE: To evaluate static and dynamic functional connectivity topological networks in patients with acute mTBI using resting-state functional magnetic resonance imaging (fMRI). MATERIAL AND METHODS: A total of 55 patients with acute mTBI and 55 age-, sex-, and education-matched healthy controls (HCs) were enrolled in this study. All participants underwent resting-state fMRI scans, and data were analyzed using graph-theory methods and a sliding window approach. Post-traumatic cognitive performance and resting-state fMRI data were collected within one week after injury. Static and dynamic functional connectivity patterns were determined by independent component analysis. Spearman's correlation analysis was further performed between fMRI changes and Montreal cognitive assessment (MoCA) scores. RESULTS: Global efficiency was lower (P = 0.02), and local efficiency (P < 0.001) and mean Cp (P < 0.001) were higher in patients with acute mTBI than in HCs. Local efficiency was correlated with visuospatial/executive performance (r = -0.421; P = 0.002) in patients with acute mTBI. Significant differences in nodal efficiency and node degree centrality (P < 0.01) were found between the mTBI and HC groups. For dynamic properties, patients with mTBI showed higher variance (P = 0.016) in global efficiency than HCs. CONCLUSIONS: The present study shows that patients with mTBI have abnormal brain functional connectome topology, especially the dynamic graph theory characteristics, which provide new insights into the role of topological network properties in patients with acute mTBI.


Assuntos
Concussão Encefálica , Conectoma , Humanos , Concussão Encefálica/diagnóstico por imagem , Rede Nervosa , Encéfalo/diagnóstico por imagem , Imageamento por Ressonância Magnética/métodos
4.
J Food Sci ; 87(12): 5276-5288, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36382852

RESUMO

The deeply oxidized pork fat (PF) is the key in the production of Chi-aroma Baijiu, a Chinese distilled spirit. Previous studies have not proposed an integrated method to promote lipid oxidation of PF, and the formation of volatiles has not been studied. In this work, an efficient method was established to promote lipid oxidation and release of volatiles of pork fat pulp (PFP) in an integrated treatment for the production of Chi-aroma Baijiu. The results showed that the acid value of PFP by lipase pretreatment (T1) was significantly elevated (p < 0.05), compared to the control (T0). Lipase-blue light-riboflavin-25°C (T2), lipase-open vial-dark-25°C (T3), and lipase-dark-40°C (T4) further promoted lipid oxidation and reached the oxidation level of PFP by F0, while T2 show the best results. The peroxide value of PFP by T2, T3, and T4 was 41.96-, 16.70- and 14.20-fold higher, and the para-anisidine value was 27.13-, 6.94- and 6.70 fold higher than that in T1. The flavor and volatile analyses showed that PFP by T2 had higher response values than T0 at six electronic nose sensors. T2-T4 promoted the release of volatiles and T2 showed the best result. T2 potentially facilitated lipid oxidation, esterification, and substance exchange of PFP, resulting in a higher type (78.57%) and content (114.50%) of volatiles than T0. The integrated treatment with lipase hydrolysis, blue light with riboflavin could promote lipid oxidation and volatiles release to improve production efficiency of deeply oxidized PF. The results would be viably applied to the production of Chi-aroma Baijiu. PRACTICAL APPLICATION: Deeply oxidized pork fat was the key to the production of Chi-aroma Baijiu, while it took a long time (at least 4 months) to prepare. The integrated treatment with lipase hydrolysis, blue light with riboflavin could promote lipid oxidation and volatiles release to improve the production efficiency of deeply oxidized pork fat. The results would be viably applied to the production of Chi-aroma Baijiu.


Assuntos
Carne de Porco , Carne Vermelha , Compostos Orgânicos Voláteis , Animais , Suínos , Compostos Orgânicos Voláteis/análise , Lipase , Carne de Porco/análise , Carne Vermelha/análise , Imersão , Riboflavina , Lipídeos
5.
Front Immunol ; 13: 873789, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35572515

RESUMO

Despite impressive progress, a significant portion of patients still experience primary or secondary resistance to chimeric antigen receptor (CAR) T-cell immunotherapy for relapsed/refractory diffuse large B-cell lymphoma (r/r DLBCL). The mechanism of primary resistance involves T-cell extrinsic and intrinsic dysfunction. In the present study, a total of 135 patients of DLBCL treated with murine CD19/CD22 cocktail CAR T-therapy were assessed retrospectively. Based on four criteria (maximal expansion of the transgene/CAR-positive T-cell levels post-infusion [Cmax], initial persistence of the transgene by the CAR transgene level at +3 months [Tlast], CD19+ B-cell levels [B-cell recovery], and the initial response to CAR T-cell therapy), 48 patients were included in the research and divided into two groups (a T-normal group [n=22] and a T-defect [n=26] group). According to univariate and multivariate regression analyses, higher lactate dehydrogenase (LDH) levels before leukapheresis (hazard ratio (HR) = 1.922; p = 0.045) and lower cytokine release syndrome (CRS) grade after CAR T-cell infusion (HR = 0.150; p = 0.026) were independent risk factors of T-cell dysfunction. Moreover, using whole-exon sequencing, we found that germline variants in 47 genes were significantly enriched in the T-defect group compared to the T-normal group (96% vs. 41%; p<0.0001), these genes consisted of CAR structure genes (n=3), T-cell signal 1 to signal 3 genes (n=13), T cell immune regulation- and checkpoint-related genes (n=9), cytokine- and chemokine-related genes (n=13), and T-cell metabolism-related genes (n=9). Heterozygous germline UNC13D mutations had the highest intergroup differences (26.9% vs. 0%; p=0.008). Compound heterozygous CX3CR1I249/M280 variants, referred to as pathogenic and risk factors according to the ClinVar database, were enriched in the T-defect group (3 of 26). In summary, the clinical characteristics and T-cell immunodeficiency genetic features may help explain the underlying mechanism of treatment primary resistance and provide novel insights into CAR T-cell immunotherapy.


Assuntos
Linfoma Difuso de Grandes Células B , Receptores de Antígenos Quiméricos , Animais , Antígenos CD19 , Humanos , Imunoterapia Adotiva/efeitos adversos , Linfoma Difuso de Grandes Células B/tratamento farmacológico , Linfoma Difuso de Grandes Células B/terapia , Proteínas de Membrana , Camundongos , Fatores R , Receptores de Antígenos Quiméricos/genética , Receptores de Antígenos Quiméricos/uso terapêutico , Estudos Retrospectivos , Lectina 2 Semelhante a Ig de Ligação ao Ácido Siálico/genética , Linfócitos T
6.
Turk J Chem ; 45(4): 1133-1145, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34707439

RESUMO

A series of Zr(SO4)2/SiO2 solid acid catalysts with different Zr(SO4)2 loadings were prepared by water-soluble-impregnation method at room temperature. Then, the prepared catalysts were characterized by Fourier transform infrared spectroscopy, transmission electron microscopy and energy-dispersive X-ray spectrum, X-ray diffraction, adsorption/desorption of N2, and temperature-programmed desorption of NH3. The results showed that the active component Zr(SO4)2 was successfully adhered to the mesoporous SiO2, and the acid amount of Zr(SO4)2/SiO2 increased with the increasing of the Zr(SO4)2 loadings. Finally, the wheat stalk was used as raw material and depolymerized over Zr(SO4)2/SiO2 to produce ethyl levulinate (EL). The reaction mixture was separated and purified by filtration and vacuum distillation. The kinetic characteristics and the reaction pathway were also studied. A comparative study showed that 20 wt.% Zr(SO4)2/SiO2 exhibited higher catalytic activity. When reaction temperature, time, catalyst dosage and Zr(SO4)2 loadings were 190 °C, 50 min, 20 wt.% and 30 wt.%, the EL yield reached a maximum of 17.14%. The relative content of EL exceeded 90% after three steps of distillation.

8.
Stem Cell Res Ther ; 12(1): 234, 2021 04 13.
Artigo em Inglês | MEDLINE | ID: mdl-33849651

RESUMO

BACKGROUND: The repair of critical-sized bone defects is always a challenging problem. Electromagnetic fields (EMFs), used as a physiotherapy for bone defects, have been suspected to cause potential hazards to human health due to the long-term exposure. To optimize the application of EMF while avoiding its adverse effects, a combination of EMF and tissue engineering techniques is critical. Furthermore, a deeper understanding of the mechanism of action of EMF will lead to better applications in the future. METHODS: In this research, bone marrow mesenchymal stem cells (BMSCs) seeded on 3D-printed scaffolds were treated with sinusoidal EMFs in vitro. Then, 5.5 mm critical-sized calvarial defects were created in rats, and the cell scaffolds were implanted into the defects. In addition, the molecular and cellular mechanisms by which EMFs regulate BMSCs were explored with various approaches to gain deeper insight into the effects of EMFs. RESULTS: The cell scaffolds treated with EMF successfully accelerated the repair of critical-sized calvarial defects. Further studies revealed that EMF could not directly induce the differentiation of BMSCs but improved the sensitivity of BMSCs to BMP signals by upregulating the quantity of specific BMP (bone morphogenetic protein) receptors. Once these receptors receive BMP signals from the surrounding milieu, a cascade of reactions is initiated to promote osteogenic differentiation via the BMP/Smad signalling pathway. Moreover, the cytokines secreted by BMSCs treated with EMF can better facilitate angiogenesis and osteoimmunomodulation which play fundamental roles in bone regeneration. CONCLUSION: In summary, EMF can promote the osteogenic potential of BMSCs and enhance the paracrine function of BMSCs to facilitate bone regeneration. These findings highlight the profound impact of EMF on tissue engineering and provide a new strategy for the clinical treatment of bone defects.


Assuntos
Células-Tronco Mesenquimais , Animais , Células da Medula Óssea , Regeneração Óssea , Diferenciação Celular , Campos Eletromagnéticos , Osteogênese , Ratos , Alicerces Teciduais
9.
J Mol Graph Model ; 104: 107842, 2021 05.
Artigo em Inglês | MEDLINE | ID: mdl-33529934

RESUMO

To study the binding mechanism of 4',6-diamidino-2-phenylindole (DAPI) and polyphosphate (Poly-P) and find fluorescent dyes which can dye Poly-P better, the interaction model of DAPI and Poly-P was calculated by the self-consistent-charge, density functional tight-binding (SCC-DFTB-D) method, and the binding sites of DAPI and Poly-P were analyzed. Further, Cy3, Rhodamine 6G and Fluorescein, which are structurally similar to DAPI, were selected to analyze their interactions with Poly-P. The binding energies and frontier orbital properties of the complexes were analyzed. These four fluorescent dyes were further used to dye the activated sludge smear and observe the fluorescence property. The Simulation results show that the N-containing indole ring structures in DAPI plays an important role in the interaction with Poly-P; the binding energies for DAPI, Cy3, Rhodamine 6G and Fluorescein with Poly-P are -42.6, -165.4, -34.7 and -28.9 kcal/mol, respectively. The frontier orbital properties for the complexes were studied, which further indicates that the interactions between Cy3, Rhodamine 6G and Poly-P are stronger than that of Fluorescein and Poly-P. The experimental results showed that Cy3 had excellent dyeing effect on Poly-P and could recognize them, while Fluorescein could not dye Poly-P. The experimental results were in good agreement with those predicted by simulation, which verified the correctness of our calculation method and provided a new strategy for finding more reliable, more sensitive and more economical fluorescent dyes capable of dyeing Poly-P.


Assuntos
Corantes Fluorescentes , Polifosfatos , Sítios de Ligação , Espectrometria de Fluorescência
10.
Stem Cell Res Ther ; 12(1): 143, 2021 02 17.
Artigo em Inglês | MEDLINE | ID: mdl-33597006

RESUMO

BACKGROUND: Intervertebral fusion is the most common surgery to treat lumbar degenerative disease (LDD). And the graft material used in the operation is derived from the iliac crest to promote fusion. However, autografts possess the fatal disadvantage of lack of source. Therefore, economical and practical bone substitutes are urgently needed to be developed. Sinusoidal electromagnetic fields (EMF) combined with tissue engineering techniques may be an appropriate way to promote intervertebral fusion. METHODS: In this research, porous scaffolds made of polycaprolactone (PCL) and nano-hydroxyapatite (nHA) were used as cell carriers. Then, the scaffolds loaded with bone marrow mesenchymal stem cells (BMSCs) were treated with sinusoidal electromagnetic field and the osteogenic capability of BMSCs was tested later. In addition, an intervertebral disc of the tail vertebra of the rat was removed to construct a spinal intervertebral fusion model with a cell-scaffold implanted. The intervertebral fusion was observed and analyzed by X-ray, micro-CT, and histological methods. RESULTS: BMSCs stimulated by EMF possess splendid osteogenic capability under an osteogenic medium (OM) in vitro. And the conditioned medium of BMSCs treated with EMF can further promote osteogenic differentiation of the primitive BMSCs. Mechanistically, EMF regulates BMSCs via BMP/Smad and mitogen-activated protein kinase (MAPK)-associated p38 signaling pathways. In vivo experiments revealed that the scaffold loaded with BMSCs stimulated by EMF accelerated intervertebral fusion successfully. CONCLUSION: In summary, EMF accelerated intervertebral fusion by improving the osteogenic capacity of BMSCs seeded on scaffolds and might boost the paracrine function of BMSCs to promote osteogenic differentiation of the homing BMSCs at the injured site. EMF combined with tissue engineering techniques may become a new clinical treatment for LDD.


Assuntos
Células-Tronco Mesenquimais , Osteogênese , Animais , Células da Medula Óssea , Diferenciação Celular , Campos Eletromagnéticos , Ratos , Engenharia Tecidual , Alicerces Teciduais
11.
J Sci Food Agric ; 101(3): 918-926, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-32737878

RESUMO

BACKGROUND: Aged pork fat, deeply oxidized pork fat soaked in basic liquor for more than half a year, is an important material in producing Chi-aroma Baijiu (CAB). With the expansion of production scale of CAB, innovative strategies for efficient production of aged pork fat are in great demand. The purpose of this study is to accelerate the lipid oxidation of pork fat and improve the productivity of aged pork fat. RESULTS: Results showed that polyunsaturated fatty acids (PUFAs) were the main reactant; generation reactions of lipid peroxides and free fatty acids (FFAs) were two limiting steps during the preparation of aged pork fat. Processing under illumination could alleviate the first limiting step by increasing the peroxide value and p-anisidine value of pork fat to 16.22- and 28.48-fold higher than control samples and simultaneously the PUFAs were increased to 190.60 ± 0.19 g kg-1 . Soaking in basic liquor with deeply oxidized fat oil could alleviate the second limiting step by transferring FFAs from fat oil into pork fat. With more oxidized PUFAs, the acid value of the pork fat was 7.91-fold higher than that of the control. CONCLUSION: Illumination and deeply oxidized fat oil could alleviate the two rate-limiting steps of lipid oxidation and improve the productivity of aged pork fat significantly. The results are highly applicable in the CAB industry. © 2020 Society of Chemical Industry.


Assuntos
Bebidas Alcoólicas/análise , Gorduras/química , Ácidos Graxos Insaturados/química , Produtos da Carne/análise , Animais , Manipulação de Alimentos , Oxirredução , Suínos
12.
Materials (Basel) ; 13(22)2020 Nov 11.
Artigo em Inglês | MEDLINE | ID: mdl-33187269

RESUMO

In existing simulations of the Almen intensity test, arc height is indirectly obtained by an equivalent method including a representative cell, a few shots and equivalent loading. Most of these equivalent methods cannot consider the transverse deformation of the strip, the complex stress state of the plastic hardening layer and process parameters, resulting in deviation from the actual test. This paper introduces an improved and experimentally validated discrete element model (DEM)-finite element model (FEM) to predict the actual Almen intensity. The improvement of this model is mainly reflected in the large and real number of shots involved in the actual Almen intensity test, shot-shot interactions, and real-size solid finite element model of the Almen strip. A new method for calculating the shot stream is proposed based on the test and considering test process parameters such as the mass flowrate, nozzle movement speed and nozzle-workpiece distance. The shot stream impacting the strip with a fully restrained underside was first simulated in improved DEM-FEM to bring the forming energy. As a second step, an implicit solver of the Almen strip FEM calculates the spring-back to simulate strip removal from the holder. The results achieved by the present approach are compared with the results obtained by the experimental results and those in the literature. The results show that the arc height and Almen intensity obtained by the present approach match much better with the literature than the traditional method. Some new results obtained by the improved coupling DEM-FEM method are presented. The influences of the transverse deformation and surface plastic layer on the deformation of the Almen strip are discussed. This improved method provides an alternative characterization method for precision peen forming simulation.

13.
Stem Cell Res Ther ; 11(1): 433, 2020 10 06.
Artigo em Inglês | MEDLINE | ID: mdl-33023631

RESUMO

BACKGROUND: Current strategies for craniofacial defect are faced with unmet outcome. Combining 3D-printing with safe, noninvasive magnetic therapy could be a promising breakthrough. METHODS: In this study, polylactic acid/hydroxyapatite (PLA/HA) composite scaffold was fabricated. After seeding rat bone marrow mesenchymal stem cells (BMSCs) on scaffolds, the effects of electromagnetic fields (EMF) on the proliferation and osteogenic differentiation capacity of BMSCs were investigated. Additionally, 6-mm critical-sized calvarial defect was created in rats. BMSC-laden scaffolds were implanted into the defects with or without EMF treatment. RESULTS: Our results showed that PLA/HA composite scaffolds exhibited uniform porous structure, high porosity (~ 70%), suitable compression strength (31.18 ± 4.86 MPa), modulus of elasticity (10.12 ± 1.24 GPa), and excellent cyto-compatibility. The proliferation and osteogenic differentiation capacity of BMSCs cultured on the scaffolds were enhanced with EMF treatment. Mechanistically, EMF exposure functioned partly by activating mitogen-activated protein kinase (MAPK) or MAPK-associated ERK and JNK pathways. In vivo, significantly higher new bone formation and vascularization were observed in groups involving scaffold, BMSCs, and EMF treatment, compared to scaffold alone. Furthermore, after 12 weeks of implanting, craniums in groups including scaffold, BMSCs, and EMF exposure showed the greatest biomechanical properties. CONCLUSION: In conclusion, EMF treatment combined with 3D-printed scaffold has great potential applications in craniofacial regeneration.


Assuntos
Osteogênese , Alicerces Teciduais , Animais , Regeneração Óssea , Campos Eletromagnéticos , Impressão Tridimensional , Ratos , Ratos Sprague-Dawley
14.
J Virol Methods ; 276: 113793, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-31794781

RESUMO

Dengue fever is a highly endemic arthropod-borne viral disease in the tropical and sub-tropical countries and is rapidly becoming a global threaten. Diagnosis has been conducted by either traditional serological methods or molecular biological techniques. However, these methods are either labor-intensive, time-consuming or with multiple steps, which are not suitable for high throughput detection of large quantity of samples. In the current study, a novel, rapid, no-wash one-step amplified luminescent proximity homogenous assay-linked immunosorbent assay (AlphaLISA) was developed and optimized for the diagnosis of dengue fever through the detection of dengue virus non-structural protein 1 (NS1). The linear range of the assay was determined to be 60,000 pg/mL to 200 pg/mL, with a lower detection limit of 127.45 pg/mL for NS1 protein. The precision of the assay was 8.24 % and 4.93 % for the high and low concentration. Clinical evaluation indicated that the sensitivity and specificity of the assay was 91.49 % and 81.54 %, respectively. This novel, rapid, no-wash one-step AlphaLISA assay is convenient and sensitive, which could be a good alternative for the screening of dengue fever in a high throughput format.


Assuntos
Vírus da Dengue/química , Dengue/diagnóstico , Imunoensaio/métodos , Proteínas não Estruturais Virais/análise , Humanos , Limite de Detecção , Reprodutibilidade dos Testes , Sensibilidade e Especificidade
15.
ISA Trans ; 83: 142-153, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-30236927

RESUMO

The impulse signal in large rotating machinery with damage fault is sparse, weak, coupled, and even nonperiodic in intermittent operation. To extract this complex signal is a key topic in machinery fault diagnosis. Sparse decomposition (SD) has excellent adaptability in describing arbitrary complex signals based on over-complete dictionary. However, the pursuit speed of best atom is a serious drawback. To alleviate this, a method of sparse decomposition based on time-frequency spectrum segmentation (SD-TFSS) is introduced. Generalized S transform (GST) provides the capability to show the distribution of vibration signals, but the resolution is susceptible to noise, multiresolution generalized S-transform (MGST) is developed to generate multiresolution time-frequency spectrums. Then, spectrums fusion with an appropriate threshold is adopted to acquire multiresolution binary spectrums and produce an optimal binary spectrum. From this optimal binary spectrum, all the connectivity areas are extracted and marked by spectrum segmentation. Thus, an optimal library can be constructed by selecting the optimal atoms of every connectivity area, and the signal can be expressed with this library. We conduct simulations and experiments demonstrating that the proposed method performs well with lower pursuit complexity, higher decomposition efficiency, and better approximation precision.

16.
Chem Commun (Camb) ; 47(12): 3529-31, 2011 Mar 28.
Artigo em Inglês | MEDLINE | ID: mdl-21311805

RESUMO

Hierarchical TS-1 with a well connected network of meso/macropores inside the zeolite crystal was directly synthesized by using caramel as the template.

18.
Space Med Med Eng (Beijing) ; 16 Suppl: 494-9, 2003.
Artigo em Chinês | MEDLINE | ID: mdl-14989304

RESUMO

OBJECTIVE: To examine and evaluate the vestibular function of Chinese astronaut candidates in order to select the astronauts with good vestibular function. METHOD: Fifty-nine male candidates, the fighter plane pilots, participated in the Caloric tests, and 38 pilots among all the candidates experienced the parallel swing and Coriolis acceleration stimuli in tests. The parameters, such as vestibule-autonomic nervous reflex symptoms, electrogastrography (EGG), electronystagmography (ENG), ECG, blood pressure, postural equilibrium ability were employed to evaluate the vestibular function. RESULT: Caloric tests indicated that there were function symmetry on both sides of semicircular canals, as well as normality of visual-vestibular and vestibulo-ocular reflexes in all the candidates. The parallel swing and Coriolis acceleration stimulus demonstrated that there were differences of vestibular functions in 38 pilots. Incidence of I category (stability type) of vestibular function exceeded 52.6%, and II category (relatively stable type) approached 42.1% as well III category (relatively susceptible type) was reported to be 5.3%. CONCLUSION: Vestibular function of astronaut candidates could be evaluated comprehensively and objectively in the present tests. The Chinese astronauts can be chosen from the candidates with stable type or relatively stable type up to standard vestibular function.


Assuntos
Astronautas , Enjoo devido ao Movimento , Seleção de Pessoal , Voo Espacial , Vestíbulo do Labirinto/fisiologia , Pressão Sanguínea/fisiologia , Testes Calóricos , China , Força Coriolis , Eletrofisiologia , Motilidade Gastrointestinal/fisiologia , Humanos , Masculino , Nistagmo Optocinético/fisiologia , Ausência de Peso
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