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1.
Neural Netw ; 169: 293-306, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37918272

RESUMO

Capturing global and subtle discriminative information using attention mechanisms is essential to address the challenge of inter-class high similarity for vehicle re-identification (Re-ID) task. Mixing self-information of nodes or modeling context based on pairwise dependencies between nodes are the core ideas of current advanced attention mechanisms. This paper aims to explore how to utilize both dependency context and self-context in an efficient way to facilitate attention to learn more effectively. We propose a heterogeneous context interaction (HCI) attention mechanism that infers the weights of nodes from the interactions of global dependency contexts and local self-contexts to enhance the effect of attention learning. To reduce computational complexity, global dependency contexts are modeled by aggregating number-compressed pairwise dependencies, and the interactions of heterogeneous contexts are restricted to a certain range. Based on this mechanism, we propose a heterogeneous context interaction network (HCI-Net), which uses channel heterogeneous context interaction module (CHCI) and spatial heterogeneous context interaction module (SHCI), and introduces a rigid partitioning strategy to extract important global and fine-grained features. In addition, we design a non-similarity constraint (NSC) that forces the HCI-Net to learn diverse subtle discriminative information. The experiment results on two large datasets, VeRi-776 and VehicleID, show that our proposed HCI-Net achieves the state-of-the-art performance. In particular, the mean average precision (mAP) reaches 83.8% on VeRi-776 dataset.


Assuntos
Aprendizado de Máquina , Redes Neurais de Computação , Veículos Automotores
2.
Drug Des Devel Ther ; 16: 1515-1530, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35611358

RESUMO

Objective: Gastric cancer is one of the most lethal malignancies in the world. However, the current research on the diagnosis and treatment of nano-ultrasound contrast agents in the field of tumor is mostly focused on breast cancer, ovarian cancer, prostate cancer, liver cancer, etc. Due to the interference of gas in the stomach, there is no report on the treatment of gastric cancer. Herpes simplex virus thymidine kinase/ganciclovir (HSV-TK/GCV) therapy system is the most mature tumor suicide gene in cancer treatment. At the same time, in order to improve its safety and efficiency, we designed a gastric tumor targeted ultrasound-triggered phase-transition nano ultrasound contrast agent PFH/AGM-CBA/HSV-TK/Liposome (PAHL)-Affibody complex. Methods: In our study, guanidinylated SS-PAAs polymer poly(agmatine/N, N'-cystamine-bis-acrylamide) (AGM-CBA) was used as a nuclear localization vector of suicide gene to form a polyplex, perfluorohexane (PFH) was used as ultrasound contrast agent, liposomes were used to encapsulate perfluorohexane droplets and the polyplexes of AGM-CBA/HSV-TK, and affibody molecules were conjugated to the prepared PAHL in order to obtain a specific targeting affinity to human epidermal growth factor receptor type 2 (ErbB2) at gastric cancer cells. With the aid of ultrasound targeted microbubble destruction technology and the nuclear localization effect of AGM-CBA vector, the transfection efficiency of the suicide gene in gastric cancer cells was significantly increased, leading to significant apoptosis of gastric cancer cells. Results: It was shown that PAHL-Affibody complex was nearly spherical with an average diameter of 560 ± 28.9 nm, having higher and specific affinity to ErbB2 (+) gastric cells. In vitro experiments further confirmed that PAHL could target gastric cancer cells expressing ErbB2. In a contrast-enhanced ultrasound scanning study, the prepared ultrasound-triggered phase-change nano-ultrasound contrast agent, PAHL, showed improved ultrasound enhancement effects. With the application of the low-frequency ultrasound, the gene transfection efficiency of PAHL was significantly improved,  thereby inducing significant apoptosis in gastric cancer cells. Conclusion: This study constructs PFH/AGM-CBA/HSV-TK/Liposome-Affibody nano ultrasound contrast agent, which provides new ideas for the treatment strategy of ErbB2-positive gastric cancer and provides some preliminary experimental basis for its inhibitory effect.


Assuntos
Neoplasias Gástricas , Timidina Quinase , Antivirais/farmacologia , Meios de Contraste/farmacologia , Fluorocarbonos , Ganciclovir/farmacologia , Humanos , Lipossomos/farmacologia , Masculino , Receptor ErbB-2 , Simplexvirus/genética , Simplexvirus/metabolismo , Neoplasias Gástricas/diagnóstico por imagem , Neoplasias Gástricas/tratamento farmacológico , Timidina Quinase/genética , Timidina Quinase/metabolismo , Transfecção , Ultrassonografia
3.
Zhonghua Zheng Xing Wai Ke Za Zhi ; 21(4): 274-7, 2005 Jul.
Artigo em Chinês | MEDLINE | ID: mdl-16248523

RESUMO

OBJECTIVE: To investigate the anatomy of penis and its adjacent organ for phalloplasty. METHODS: Anatomic dissection of penis and perineum was performed on 30 adult male cadavers (60 sides). Observation and measurement were focused on the penile length of different parts, the morphological relationship of infundibular ligament and suspensory ligament with penile radix, and the feature of crus penis with relation to the deep penile artery. RESULTS: The average length of the penile shaft was 8.13 cm, the penile radix was 7.67 cm and the crus penis was 5.96 - 5.98 cm. The deep penile artery penetrated into the crus penis at its middle 1/3. The infundibular ligament attached to superficial fascia of the penis and extended downward to the scrotal septum to constitute the suspensory structure for both of them. The suspensory ligament attached to the dorsal deep fascia of the penis. Becoming thicker, the rear part of the suspensory ligament connected firmly to the pubic arcuate ligament to constitute a part of suspensory mechanism for the urethra. There was a part of cavernous body, which was free from either ligament or bony attachment, between the penile radix and the crus penis, where the dorsal artery and nerve of penis turned around from the ventral to the dorsal aspect of the penis and the penile dorsal vain penetrated the urogenital septum, draining into intrapelvic venous plexus. CONCLUSIONS: The divisional measurement of the penis length, the recognition of the suspensory ligaments and the anatomic feature of the crus penis with relation to the deep penile artery are all of significant importance to improve the operation of phalloplasty.


Assuntos
Pênis/anatomia & histologia , Adolescente , Adulto , Idoso , Humanos , Masculino , Pessoa de Meia-Idade , Períneo/anatomia & histologia , Procedimentos de Cirurgia Plástica/métodos , Adulto Jovem
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