RESUMEN
In practical applications, polyurethane (PU) foam must be rigid to meet the demands of various industries and provide comfort and protection in everyday life. PU foam components are extensively used in structural foam, thermal insulation, decorative panels, packaging, imitation wood, and floral foam, as well as in models and prototypes. Conventional technology for producing PU foam parts often leads to defects such as deformation, short shots, entrapped air, warpage, flash, micro-bubbles, weld lines, and voids. Therefore, the development of rigid PU foam parts has become a crucial research focus in the industry. This study proposes an innovative manufacturing process for producing rigid PU foam parts using silicone rubber molds (SRMs). The deformation of the silicone rubber mold can be predicted based on its wall thickness, following a trend equation with a correlation coefficient of 0.9951. The volume of the PU foam part can also be predicted by the weight of the PU foaming agent, as indicated by a trend equation with a correlation coefficient of 0.9824. The optimal weight ratio of the foaming agent to water, yielding the highest surface hardness, was found to be 5:1. The surface hardness of the PU foam part can also be predicted based on the weight of the water used, according to a proposed prediction equation with a correlation coefficient of 0.7517. The average surface hardness of the fabricated PU foam part has a Shore O hardness value of approximately 75. Foam parts made with 1.5 g of water added to 15 g of a foaming agent have the fewest internal pores, resulting in the densest interior. PU foam parts exhibit excellent mechanical properties when 3 g of water is added to the PU foaming agent, as evidenced by their surface hardness and compressive strength. Using rigid PU foam parts as a backing material in the proposed method can reduce rapid tool production costs by about 62%. Finally, an innovative manufacturing process for creating large SRMs using rigid PU foam parts as backing material is demonstrated.
RESUMEN
Gastric adenocarcinoma, commonly known as stomach cancer, has a predilection for metastasis to the peritoneum, which portends limited survival. The peritoneal metastatic cascade remains poorly understood, and existing models fail to recapitulate key elements of the interaction between cancer cells and the peritoneal layer. To explore the underlying cellular and molecular mechanisms of peritoneal metastasis, we developed an ex vivo human peritoneal explant model. Fresh peritoneal tissue samples were suspended, mesothelial layer down but without direct contact, above a monolayer of red-fluorescent dye stained AGS human gastric adenocarcinoma cells for 24 h, then washed thoroughly. Implantation of AGS cells within the explanted peritoneum and invasion beyond the mesothelial layer were examined serially using real-time confocal fluorescence microscopy. Histoarchitecture of the explanted peritoneum was preserved over 5 days ex vivo. Both implantation and invasion were suppressed by restoration of functional E-cadherin through stable transfection of AGS cells, demonstrating sensitivity of the model to molecular manipulation. Thus, our ex vivo human peritoneal explant model permits meaningful investigation of the pathways and mechanism that contribute to peritoneal metastasis. The model will facilitate screening of new therapies that target peritoneal dissemination of gastric, ovarian and colorectal cancer.
Asunto(s)
Adenocarcinoma , Neoplasias Peritoneales , Neoplasias Gástricas , Adenocarcinoma/patología , Línea Celular Tumoral , Humanos , Neoplasias Peritoneales/secundario , Peritoneo/patología , Neoplasias Gástricas/patologíaRESUMEN
To improve anaerobic digestion biogas yield, the removal of organic-bonding metals by EDTA pretreatment was investigated to strengthen the anaerobic biogas effect. The results showed that after EDTA pretreatment (experimental group), the organic-bonding metals were reduced from (5.09±0.57)% to (1.37±0.20)% (calculated with TS) and dissolved organic matter increased significantly (SCOD improved 627%), suggesting that this method could remove a large amount of organic-bonding metals and enhance the dissolution of organic sludge. According to the results for the apparent activation energy (AAE) of sludge organic matter dissolution, the AAE of the experiment group was 36% lower than the control group, showing that pretreatment could effectively reduce the reaction energy barrier for organic matter dissolution. In a test of anaerobic acid production lasting 16 days, the VFAs of the experiment group were higher than the control group, with the largest upgrade of 42%. In the anaerobic methane production test (BMP) that lasted for 22 days, compared with control group, the accumulated biogas production of the experiment group increased by 48%. Through further research on the dynamics of methane production, the rate-limiting step in the experiment group was methanogenesis, while that of the control group was hydrolysis, indicating that removal of organic-bonding metals by EDTA pretreatment could effectively accelerate the hydrolysis rate.
Asunto(s)
Reactores Biológicos , Metales/aislamiento & purificación , Metano/biosíntesis , Aguas del Alcantarillado/química , AnaerobiosisRESUMEN
Neuroligins (NLs) are critical for synapse formation and function. NL3 R451C is an autism-associated mutation. NL3 R451C knockin (KI) mice exhibit autistic behavioral abnormalities, including social novelty deficits. However, neither the brain regions involved in social novelty nor the underlying mechanisms are clearly understood. Here, we found decreased excitability of fast-spiking interneurons and dysfunction of gamma oscillation in the medial prefrontal cortex (mPFC), which contributed to the social novelty deficit in the KI mice. Neuronal firing rates and phase-coding abnormalities were also detected in the KI mice during social interactions. Interestingly, optogenetic stimulation of parvalbumin interneurons in the mPFC at 40 Hz nested at 8 Hz positively modulated the social behaviors of mice and rescued the social novelty deficit in the KI mice. Our findings suggest that gamma oscillation dysfunction in the mPFC leads to social deficits in autism, and manipulating mPFC PV interneurons may reverse the deficits in adulthood.
Asunto(s)
Moléculas de Adhesión Celular Neuronal/genética , Moléculas de Adhesión Celular Neuronal/metabolismo , Ritmo Gamma/fisiología , Aprendizaje por Laberinto/fisiología , Proteínas de la Membrana/genética , Proteínas de la Membrana/metabolismo , Proteínas del Tejido Nervioso/genética , Proteínas del Tejido Nervioso/metabolismo , Corteza Prefrontal/metabolismo , Conducta Social , Animales , Trastorno Autístico/genética , Trastorno Autístico/fisiopatología , Técnicas de Sustitución del Gen/métodos , Células HEK293 , Humanos , Masculino , Ratones , Ratones Transgénicos , Optogenética/métodos , Corteza Prefrontal/fisiopatología , Distribución AleatoriaRESUMEN
Varicocele is one of the most common diseases in the male reproductive system. More and more attention has been drawn to the influence of varicocele on male reproduction recently. Although many experiments and achievements have been made, the mechanism of infertility in varicocele patients has not yet been fully understood. The development of the disease might be related to many factors such as microcirculation of the testis, vasoactive substance, reactive oxygen species, nitric oxide, hypoxia, immunology and apoptosis. Mostly these changes are not confined to one testis. Thus, it is of great significance to investigate the mechanism of male infertility induced by varicocele. This article updates the studies on the mechanism of infertility in varicocele males.