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1.
Neural Netw ; 175: 106289, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38593559

RESUMO

Most metric-based Few-Shot Learning (FSL) methods focus on learning good embeddings of images. However, these methods either lack the ability to explore the cross-correlation (i.e., correlated information) between image pairs or explore limited consensus among the correlation map constrained by the limited receptive field of CNN. We propose a Mutual Correlation Network (MCNet) to explore global consensus among the correlation map by using the self-attention mechanism which has a global receptive field. Our MCNet contains two core modules: (1) a multi-level embedding module that generates multi-level embeddings for an image pair which capture hierarchical semantics, and (2) a mutual correlation module that refines correlation map of two embeddings and generates more robust relational embeddings. Extensive experiments show that our MCNet achieves competitive results on four widely-used few-shot classification benchmarks miniImageNet, tieredImageNet, CUB-200-2011, and CIFAR-FS. Code is available at https://github.com/DRGreat/MCNet.


Assuntos
Redes Neurais de Computação , Humanos , Algoritmos , Processamento de Imagem Assistida por Computador/métodos , Aprendizado de Máquina , Semântica
2.
Cells ; 13(4)2024 Feb 08.
Artigo em Inglês | MEDLINE | ID: mdl-38391926

RESUMO

Due to the increasing trend of delayed childbirth, the age-related decline in male reproductive function has become a widely recognized issue. Sertoli cells (SCs) play a vital role in creating the necessary microenvironment for spermatogenesis in the testis. However, the mechanism underlying Sertoli cell aging is still unclear. In this study, senescent Sertoli cells showed a substantial upregulation of miR-143-3p expression. miR-143-3p was found to limit Sertoli cell proliferation, promote cellular senescence, and cause blood-testis barrier (BTB) dysfunction by targeting ubiquitin-conjugating enzyme E2 E3 (UBE2E3). Additionally, the TGF-ß receptor inhibitor SB431542 showed potential in alleviating age-related BTB dysfunction, rescuing testicular atrophy, and reversing the reduction in germ cell numbers by negatively regulating miR-143-3p. These findings clarified the regulatory pathways underlying Sertoli cell senescence and suggested a promising therapeutic approach to restore BTB function, alleviate Sertoli cell senescence, and improve reproductive outcomes for individuals facing fertility challenges.


Assuntos
MicroRNAs , Células de Sertoli , Humanos , Masculino , Células de Sertoli/metabolismo , Barreira Hematotesticular/metabolismo , Testículo , MicroRNAs/genética , MicroRNAs/metabolismo , Senescência Celular
3.
Small ; 20(1): e2303832, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37670542

RESUMO

Protonation has been considered essential for the pseudocapacitive energy storage of polyaniline (PANI) for years, as proton doping in PANI chains not only activates electron transport pathways, but also promotes the proceeding of redox reactions. Rarely has the ability for PANI of storing energy without protonation been investigated, and it remains uncertain whether PANI has pseudocapacitive charge storage properties in an alkaline electrolyte. Here, this work first demonstrates the pseudocapacitive energy storage for PANI without protonation using a PANI/graphene composite as a model material in an alkaline electrolyte. Using in situ Raman spectroscopy coupled with electrochemical quartz crystal microbalance (EQCM) measurements, this work determines the formation of -N= group over potential on a PANI chain and demonstrates the direct contribution of OH- in the nonprotonation type of oxidation reactions. This work finds that the PANI/graphene composite in an alkaline electrolyte has excellent cycling stability with a wider operation voltage of 1 V as well as a slightly higher specific capacitance than that in an acidic electrolyte. The findings provide a new perspective on pseudocapacitive energy storage of PANI-based composites, which will influence the selection of electrolytes for PANI materials and expand their application in energy storage fields.

4.
Mol Ther Nucleic Acids ; 32: 879-895, 2023 Jun 13.
Artigo em Inglês | MEDLINE | ID: mdl-37273781

RESUMO

MicroRNAs (miRNAs) regulate various cellular functions, but their specific roles in the regulation of Leydig cells (LCs) have yet to be fully understood. Here, we found that the expression of miR-300-3p varied significantly during the differentiation from progenitor LCs (PLCs) to adult LCs (ALCs). High expression of miR-300-3p in PLCs inhibited testosterone production and promoted PLC proliferation by targeting the steroidogenic factor-1 (Sf-1) and transcription factor forkhead box O1 (FoxO1) genes, respectively. As PLCs differentiated into ALCs, the miR-300-3p expression level significantly decreased, which promoted testosterone biosynthesis and suppressed proliferation of ALCs by upregulating SF-1 and FoxO1 expression. The LH/METTL3/SMURF2/SMAD2 cascade pathway controlled miR-300-3p expression, in which luteinizing hormone (LH) upregulated SMAD-specific E3 ubiquitin protein ligase 2 (SMURF2) expression through methyltransferase like 3 (METTL3)-mediated Smurf2 N6-methyladenosine modification. The Smurf2 then suppressed miR-300 transcription by inhibiting SMAD family member 2 (SMAD2) binding to the promoter of miR-300. Notably, miR-300-3p was associated with an obesity-related testosterone deficiency in men and the inhibition of miR-300-3p effectively rescued testosterone deficiency in obese mice. These findings suggested that miR-300-3p plays a pivotal role in LC differentiation and function, and could be a promising diagnostic or therapeutic target for obesity-related testosterone deficiency.

5.
Adv Mater ; 35(29): e2300580, 2023 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-37037650

RESUMO

The assembly of 3D structured materials from 2D units paves a royal road for building thick and dense electrodes, which are long sought after for practical energy-storage devices. 2D transitional metal carbides (MXene) are promising for this due to their capabilities of solution-based assembly and intrinsic high density, yet face huge challenges in yielding high areal capacitance electrodes owing to the absence of porous ion-transport paths. Here, a gelation-densification process initiated by hydroiodide acids (HI) is proposed, where the protons break the electrostatic balance of MXene nanosheets to trigger gelation, while HI serves as a spacer to prevent nanosheets from restacking during capillary shrinkage. More promising, the controlled evaporation of reductive HI leaves superiorly shrinking yet porous network for ion transport, and the produced monoliths exhibit a high density of 2.74 g cm-3 and an unprecedented areal capacitance of 18.6 F cm-2 .

6.
Antioxidants (Basel) ; 11(12)2022 Nov 22.
Artigo em Inglês | MEDLINE | ID: mdl-36552521

RESUMO

Cyclobutane pyrimidine dimers (CPDs) are the main mutagenic DNA photoproducts caused by ultraviolet B (UVB) radiation and represent the major cause of photoaging and skin carcinogenesis. CPD photolyase can efficiently and rapidly repair CPD products. Therefore, they are candidates for the prevention of photodamage. However, these photolyases are not present in placental mammals. In this study, we produced a recombinant photolyase-thymine (rPHO) from Thermus thermophilus (T. thermophilus). The rPHO displayed CPD photorepair activity. It prevented UVB-induced DNA damage by repairing CPD photoproducts to pyrimidine monomers. Furthermore, it inhibited UVB-induced ROS production, lipid peroxidation, inflammatory responses, and apoptosis. UVB-induced wrinkle formation, epidermal hyperplasia, and collagen degradation in mice skin was significantly inhibited when the photolyase was applied topically to the skin. These results demonstrated that rPHO has promising protective effects against UVB-induced photodamage and may contribute to the development of anti-UVB skin photodamage drugs and cosmetic products.

7.
Biofabrication ; 15(1)2022 Oct 27.
Artigo em Inglês | MEDLINE | ID: mdl-36219953

RESUMO

Increasing rates of male infertility require more experimental models to understand the mechanisms underlying male infertility.In vitroorganoids hold unprecedented promise for this purpose; however, the development of organoids with tissue architecture similar to that of the testisin vivoremains a challenge. Here, we generated testicular organoids derived from testicular cells by combining a hanging drop culture and a rotation culture system. Our results indicated that testicular cells could self-assemble into spheroid organoids with tubule-like structures in hanging drop culture. The organoids can subsequently be cultured and maintained in a rotation culture system. These established organoids have gene expression profiles similar to those of adult testis tissue, produce testosterone with preserved gonadotropin responsiveness, and exhibit sensitivity to reproductive toxicants. More importantly, each testicular organoid can be generated from only 2000 cells, and they maintain their proliferative ability after freezing and thawing. These features make it possible to obtain fresh primary testis cells from testicular biopsies taken from patients or endangered wild species, and to build individual-specific biobanks. These findings will help enable the exploration of self-organization process of testicular cells and provide an experimental model for reproductive biology research, pharmacotoxicology testing, and regenerative medicine.


Assuntos
Infertilidade Masculina , Testículo , Adulto , Humanos , Masculino , Camundongos , Animais , Organoides , Espermatogênese , Testosterona/metabolismo , Infertilidade Masculina/metabolismo
8.
Sensors (Basel) ; 22(13)2022 Jun 25.
Artigo em Inglês | MEDLINE | ID: mdl-35808310

RESUMO

Block compressed sensing (BCS) is suitable for image sampling and compression in resource-constrained applications. Adaptive sampling methods can effectively improve the rate-distortion performance of BCS. However, adaptive sampling methods bring high computational complexity to the encoder, which loses the superiority of BCS. In this paper, we focus on improving the adaptive sampling performance at the cost of low computational complexity. Firstly, we analyze the additional computational complexity of the existing adaptive sampling methods for BCS. Secondly, the adaptive sampling problem of BCS is modeled as a distortion minimization problem. We present three distortion models to reveal the relationship between block sampling rate and block distortion and use a simple neural network to predict the model parameters from several measurements. Finally, a fast estimation method is proposed to allocate block sampling rates based on distortion minimization. The results demonstrate that the proposed estimation method of block sampling rates is effective. Two of the three proposed distortion models can make the proposed estimation method have better performance than the existing adaptive sampling methods of BCS. Compared with the calculation of BCS at the sampling rate of 0.1, the additional calculation of the proposed adaptive sampling method is less than 1.9%.


Assuntos
Compressão de Dados , Redes Neurais de Computação , Processamento de Imagem Assistida por Computador
9.
Adv Biol (Weinh) ; 6(5): e2101184, 2022 05.
Artigo em Inglês | MEDLINE | ID: mdl-35212192

RESUMO

Sertoli cells (SCs) are vital to providing morphological and nutritional support for spermatogenesis. Defects in SCs often lead to infertility. SCs transplantation is a promising potential strategy to compensate for SC dysfunction. However, isolation of SCs from testes is impractical due to obvious and ethical limitations. Here, a molecular cocktail is identified comprising of pan-BET family inhibitor (I-BET151), retinoic acid, and riluzole that enables the efficient conversion of fibroblasts into functional Sertoli-like cells (CiSCs). The gene expression profiles of CiSCs resemble those of mature SCs and exhibit functional properties such as the formation of testicular seminiferous tubules, engulfment of apoptotic sperms, supporting the survival of germ cells, and suppressing proliferation of primary lymphocytes in vitro. Moreover, CiSCs are sensitive to toxic substances, making them an alternative model to study the deleterious effects of toxicants on SCs. The study provides an efficient approach to reprogram fibroblasts into functional SCs by using pure chemical compounds.


Assuntos
Túbulos Seminíferos , Células de Sertoli , Fibroblastos , Humanos , Masculino , Reprodução , Túbulos Seminíferos/metabolismo , Espermatogênese/genética , Testículo
10.
Entropy (Basel) ; 23(10)2021 Oct 16.
Artigo em Inglês | MEDLINE | ID: mdl-34682078

RESUMO

Block compressed sensing (BCS) is a promising technology for image sampling and compression for resource-constrained applications, but it needs to balance the sampling rate and quantization bit-depth for a bit-rate constraint. In this paper, we summarize the commonly used CS quantization frameworks into a unified framework, and a new bit-rate model and a model of the optimal bit-depth are proposed for the unified CS framework. The proposed bit-rate model reveals the relationship between the bit-rate, sampling rate, and bit-depth based on the information entropy of generalized Gaussian distribution. The optimal bit-depth model can predict the optimal bit-depth of CS measurements at a given bit-rate. Then, we propose a general algorithm for choosing sampling rate and bit-depth based on the proposed models. Experimental results show that the proposed algorithm achieves near-optimal rate-distortion performance for the uniform quantization framework and predictive quantization framework in BCS.

11.
Entropy (Basel) ; 22(1)2020 Jan 20.
Artigo em Inglês | MEDLINE | ID: mdl-33285900

RESUMO

Compressed sensing (CS) offers a framework for image acquisition, which has excellent potential in image sampling and compression applications due to the sub-Nyquist sampling rate and low complexity. In engineering practices, the resulting CS samples are quantized by finite bits for transmission. In circumstances where the bit budget for image transmission is constrained, knowing how to choose the sampling rate and the number of bits per measurement (bit-depth) is essential for the quality of CS reconstruction. In this paper, we first present a bit-rate model that considers the compression performance of CS, quantification, and entropy coder. The bit-rate model reveals the relationship between bit rate, sampling rate, and bit-depth. Then, we propose a relative peak signal-to-noise ratio (PSNR) model for evaluating distortion, which reveals the relationship between relative PSNR, sampling rate, and bit-depth. Finally, the optimal sampling rate and bit-depth are determined based on the rate-distortion (RD) criteria with the bit-rate model and the relative PSNR model. The experimental results show that the actual bit rate obtained by the optimized sampling rate and bit-depth is very close to the target bit rate. Compared with the traditional CS coding method with a fixed sampling rate, the proposed method provides better rate-distortion performance, and the additional calculation amount amounts to less than 1%.

12.
Biomed Res Int ; 2020: 6842479, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32280696

RESUMO

OBJECTIVE: To investigate the risk factors of systemic inflammatory response syndrome (SIRS) induced by flexible ureteroscope combined with Holmium laser lithotripsy. Patients and Methods. The clinical data from 216 consecutive patients who had undergone flexible ureteroscope combined with Holmium laser lithotripsy between August 2015 and May 2019 were retrospectively analyzed. To identify the risk factors of systemic inflammatory response syndrome induced by flexible ureteroscope combined with Holmium laser lithotripsy, the cases were divided into two groups according to whether they developed postoperative SIRS: SIRS group (21 cases) and non-SIRS group (195 cases). Age, gender, body mass index, stone size, surgery time, stone location, hydronephrosis, urine culture, hospital stay, stone-free rate, ureteral access sheath, and diabetes mellitus were collected. Univariate analysis was performed to calculate the potential factors. In order to determine the independence of the various factors, factors that potentially contributed to SIRS were compared between the SIRS group and the non-SIRS group. Furthermore, multivariate logistic regression analysis was used to identify the risk factors of systemic inflammatory response syndrome induced by flexible ureteroscopic lithotripsy. RESULTS: All patients were successfully treated with flexible ureteroscopic lithotripsy. The incidence of SIRS after flexible ureteroscopic lithotripsy was 9.7%. The univariate analysis demonstrated the potential risk factors of systemic inflammatory response syndrome induced by flexible ureteroscopic lithotripsy were stone size (p = 0.002), surgery time (p = 0.002), surgery time (p = 0.002), surgery time (p = 0.002), surgery time (p = 0.002), surgery time (p = 0.002), surgery time (p = 0.002), surgery time (p = 0.002), surgery time (. CONCLUSIONS: Stone size, surgery time, urine culture, and ureteral access sheath are independent risk factors for SIRS induced by flexible ureteroscopic lithotripsy. Patients with these high-risk factors should be carefully evaluated to reduce systemic inflammatory response syndrome.


Assuntos
Lasers de Estado Sólido/efeitos adversos , Litotripsia a Laser/efeitos adversos , Síndrome de Resposta Inflamatória Sistêmica/epidemiologia , Ureteroscópios/efeitos adversos , Adulto , Índice de Massa Corporal , Feminino , Humanos , Incidência , Tempo de Internação , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Duração da Cirurgia , Estudos Retrospectivos , Fatores de Risco , Síndrome de Resposta Inflamatória Sistêmica/etiologia , Ureteroscopia , Coleta de Urina
13.
Appl Opt ; 55(13): 3435-41, 2016 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-27140352

RESUMO

A weighted pose estimation method using lines that intersect at a point is proposed. Because of the weak constraints, the accuracy of pose estimation using lines in this configuration is sensitive to the error of a two-dimensional (2D) line parameter. Therefore, we construct the objective function directly based on weighted image line points instead of 2D lines; the influence of errors introduced through image line points is reduced by the reasonably designed weights. The translation parameter T cannot be determined based on lines in this configuration; thus, when the rotation R is obtained, T is solved linearly by introducing one or more additional points. The experimental results indicate that our method outperforms other methods in terms of accuracy and noise robustness.

14.
IEEE Trans Image Process ; 25(2): 713-25, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26730707

RESUMO

This paper constructs a set partition coding system (SPACS) to combine the advantages of different types of set partition coding algorithms. General tree (GT) is an important conception introduced in this paper, which can represent tree set and square set simultaneously. With the help of GT, SPIHT is generalized to construct degree- k SPIHT based on the analysis of two kinds of set partition operations. Using the same coding mechanism, SPACS (k,p) is constructed, aided with virtual subbands that are generated by recursive division on the LL band. SPACS belongs to tree-set partition coding algorithms if k and p take smaller values. In particular, SPACS(2,1) is the classical SPIHT. SPACS tends toward a block-set partition coding algorithm as k,p increases. Location bit, amplitude bit, and unnecessary bit are presented, which can be used to analyze the coding efficiency of SPACS. We compress 256 images with 512×512 using SPACS. The numerical results show SPACS achieves some improvements in coding efficiency over SPIHT, especially at very low bitrate. On average, to code every image, SPACS(3,1) (at an average of 3.93 bpp) needs 7792 more location bits but saves 10 218 unnecessary bits, compared with SPIHT (3.94 bpp).

15.
Vaccine ; 33(51): 7183-7187, 2015 Dec 16.
Artigo em Inglês | MEDLINE | ID: mdl-26562317

RESUMO

BACKGROUND: The aim of this study is to characterize the sera-epidemiology of pertussis immunity levels among community populations and to identify the underlying factors. Moreover, our study will help resolve new issues encountered during the control and prevention of pertussis reemergence. METHODS: The anti-pertussis antibody levels among community populations were examined using enzyme linked immunosorbent assays (ELISA) over three years. Comparative studies were carried out to assess the efficacy of different types of vaccines. Meanwhile, the duration of protection provided by DTaP within the under-7 age group was subjected to further analysis. RESULTS: The average positive rate for anti-pertussis antibody was 49.15% across all community populations, among which the 4-12 age group showed a rate substantially lower than those of other groups (P<0.001). There was no statistically significant difference in anti-pertussis antibody levels (P=0.977) between people receiving three and four doses of the vaccine. The surveillance results showed that the positive antibody response rate elicited by component pertussis combo (DTcP) vaccines (84.44%) was strikingly higher than that elicited by acellular pertussis combo (DTaP) vaccines (37.22%, P<0.001). More specifically, when given 4 doses of DTcP vaccines, 66.67% of the people showed positive anti-pertussis toxin (PT) antibody levels, which was higher than the ratio of 9.87% (P<0.001) in the case of DTaP vaccines. The positive anti-pertussis antibody levels peaked at 73% within the first five months following vaccination and then gradually decreased to below 20% in four years. The positive rate was inversely correlated with the length of time after vaccination (r=-0.929, P=0.003). CONCLUSIONS: The anti-pertussis antibody levels were not only relatively low among community populations, but also dropped excessively rapidly among vaccinated populations. Natural infection is an important contributor to the high pertussis immunity levels seen in adolescents and adults. The efficacy of DTaP remains to be improved.


Assuntos
Anticorpos Antibacterianos/sangue , Coqueluche/imunologia , Adolescente , Adulto , Idoso , Criança , Pré-Escolar , China , Vacinas contra Difteria, Tétano e Coqueluche Acelular/imunologia , Ensaio de Imunoadsorção Enzimática , Feminino , Humanos , Lactente , Masculino , Pessoa de Meia-Idade , Estudos Soroepidemiológicos , Coqueluche/prevenção & controle , Adulto Jovem
16.
Sensors (Basel) ; 14(6): 10124-45, 2014 Jun 10.
Artigo em Inglês | MEDLINE | ID: mdl-24919014

RESUMO

We propose a new integrated target tracking, recognition and segmentation algorithm, called ATR-Seg, for infrared imagery. ATR-Seg is formulated in a probabilistic shape-aware level set framework that incorporates a joint view-identity manifold (JVIM) for target shape modeling. As a shape generative model, JVIM features a unified manifold structure in the latent space that is embedded with one view-independent identity manifold and infinite identity-dependent view manifolds. In the ATR-Seg algorithm, the ATR problem formulated as a sequential level-set optimization process over the latent space of JVIM, so that tracking and recognition can be jointly optimized via implicit shape matching where target segmentation is achieved as a by-product without any pre-processing or feature extraction. Experimental results on the recently released SENSIAC ATR database demonstrate the advantages and effectiveness of ATR-Seg over two recent ATR algorithms that involve explicit shape matching.

17.
Guang Pu Xue Yu Guang Pu Fen Xi ; 28(7): 1445-8, 2008 Jul.
Artigo em Chinês | MEDLINE | ID: mdl-18844136

RESUMO

One of the problems limiting the utility of hyperspectral imagery is how to compress the large number of data effectively. The current methods cannot resolve the problem of the contradiction between large compression rate and spectral information veracious reservation, even the best loss compression method can not bring the satisfying result. The paper presented a loss compression method based on the endmember extraction technology, so as to resolve the contradiction between large compression ratio and spectrum preserved accurately. The endmembers were obtained with vertex component analysis (VCA) and the fractions of them were estimated based on the proportion of cosine angle similitude between endmembers and observed spectrum. The endmembers spectrum and fraction were compressed with the lossless compression method and JPEG2000 loss compression method was used for all of the hyperspectral single-band images to increase compression ratio. The experiment on the AVIRIS data shows that compression ratio was increased greatly and the spectra were resumed effectively. When the compression ratio is 50 : 1, the spectrum angle loss is about 2% for most pixels.

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