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1.
J Environ Manage ; 302(Pt A): 113960, 2022 Jan 15.
Artículo en Inglés | MEDLINE | ID: mdl-34700076

RESUMEN

The rapid specialization of livestock production in China has contributed to spatially decoupled crop and livestock production, leading to various environmental pollution issues. Some regional agro-environmental policies have recently promoted the coupling of specialized crop and livestock farms through cooperation. However, the environmental and economic performances of such cooperation remain unclear. This study investigated multiple environmental footprints of two contrasting production systems: cooperative crop-livestock systems (CCLS) and decoupled specialized livestock systems (DSLS), using survey data of 87 ruminant farms in Northwest China. Results show that farms in CCLS had lower net greenhouse gas (GHG) emissions (12-29%), lower reactive nitrogen (Nr) emissions (21-40%), lower phosphorus footprints (PF) (41-54%), and used less cropland (24-31%) per kg animal product, compared to those in DSLS. The large differences in GHG emissions between the two systems were mainly related to enteric fermentation and resource production (used for feed production). The differences in Nr emissions and PF were mainly related to manure management. Net profits per kg animal product were higher in CCLS (13-35%) than in DSLS, and most profits originated from lower purchasing costs of feed and young livestock. Net profits and environmental footprints were negatively correlated, suggesting an environmental and economic win-win situation for CCLS. The possible obstacles to recoupling specialized crop and livestock farms through cooperation have been discussed, including farm size, contract stability, and local policies. Our study provides science-based evidence to support policymakers and specialized farms to close nutrient loops between crop and livestock production sectors through regional cooperation.


Asunto(s)
Gases de Efecto Invernadero , Ganado , Animales , Granjas , Estiércol , Nitrógeno
2.
Sci Rep ; 14(1): 14525, 2024 Jun 24.
Artículo en Inglés | MEDLINE | ID: mdl-38914642

RESUMEN

To achieve high-efficiency combustion of heavy fuel oil (HFO), this study investigated the combustion characteristics of methanol/HFO droplets with methanol content from 10 to 30% using the suspension method under ambient temperature from 923 to 1023 K. The combustion of methanol/HFO droplets was summarized as a two-phase process consisting of six typical stages, emphasizing liquid phase. Especially, the fluctuation evaporation stage, induced by frequent and intense puffing, was identified as prominent character. Both the ignition delay and lifetime of HFO and methanol/HFO droplets decreased with increasing ambient temperatures. For the methanol/HFO droplet, the ignition delay and droplet lifetime increased with the increasing methanol content. Prominently, compared to HFO, HM10 had the most significant reduction in droplet lifetime and TINL under the same operating conditions, which indicated that the addition of 10% methanol accelerated the combustion process and reduced soot generation. Additionally, the thermos-dynamic characteristics of methanol/HFO droplets were investigated. Puffing was primarily attributed to superheating of methanol and pyrolysis of heavy components in HFO, which resulted in active and passive rupture of bubbles. Similarity and maximum deformation were employed to qualitatively distinguish between them. The obtained findings aimed to develop a promising alternative fuel to reduce emissions and preserve energy.

3.
Front Immunol ; 14: 1189323, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37292204

RESUMEN

Head and neck squamous cell carcinomas (HNSCCs) refers to a group of highly malignant and pathogenically complex tumors. Traditional treatment methods include surgery, radiotherapy, and chemotherapy. However, with advancements in genetics, molecular medicine, and nanotherapy, more effective and safer treatments have been developed. Nanotherapy, in particular, has the potential to be an alternative therapeutic option for HNSCC patients, given its advantageous targeting capabilities, low toxicity and modifiability. Recent research has highlighted the important role of the tumor microenvironment (TME) in the development of HNSCC. The TME is composed of various cellular components, such as fibroblasts, vascular endothelial cells, and immune cells, as well as non-cellular agents such as cytokines, chemokines, growth factors, extracellular matrix (ECM), and extracellular vesicles (EVs). These components greatly influence the prognosis and therapeutic efficacy of HNSCC, making the TME a potential target for treatment using nanotherapy. By regulating angiogenesis, immune response, tumor metastasis and other factors, nanotherapy can potentially alleviate HNSCC symptoms. This review aims to summarize and discuss the application of nanotherapy that targets HNSCC's TME. We highlight the therapeutic value of nanotherapy for HNSCC patients.


Asunto(s)
Carcinoma de Células Escamosas , Neoplasias de Cabeza y Cuello , Humanos , Carcinoma de Células Escamosas de Cabeza y Cuello/terapia , Carcinoma de Células Escamosas/tratamiento farmacológico , Carcinoma de Células Escamosas/metabolismo , Neoplasias de Cabeza y Cuello/terapia , Microambiente Tumoral , Células Endoteliales/metabolismo
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