Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 8 de 8
Filtrar
Más filtros










Base de datos
Intervalo de año de publicación
1.
Int J Oncol ; 64(3)2024 03.
Artículo en Inglés | MEDLINE | ID: mdl-38214378

RESUMEN

Long­stranded non­coding RNAs (lncRNAs) are RNAs that consist of >200 nucleotides. The majority of lncRNAs do not encode proteins but have been revealed to mediate a variety of important physiological functions. Antisense­lncRNAs (AS­lncRNAs) are transcribed from the opposite strand of a protein or non­protein coding gene as part of the antisense strand of the coding gene. AS­lncRNAs can serve an important role in the tumorigenesis, prognosis, metastasis and drug resistance of a number of malignancies. This has been reported to be exerted through various mechanisms, such as endogenous competition, promoter interactions, direct interactions with mRNAs, acting as 'scaffolds' to regulate mRNA half­life, interactions with 5­untranslated regions and regulation of sense mRNAs. AS­lncRNAs have been found to either inhibit or promote tumor aggressiveness by regulating cell proliferation, energy metabolism, inflammation, inflammatory­carcinoma transformation, invasion, migration and angiogenesis. In addition, accumulating evidence has documented that AS­lncRNAs can regulate tumor therapy resistance. Therefore, targeting aberrantly expressed AS­lncRNAs for cancer treatment may prove to be a promising approach to reverse therapy resistance. In the present review, research advances on the role of AS­lncRNAs in tumor occurrence and development were summarized, with the aim of providing novel ideas for further research in this field.


Asunto(s)
Neoplasias , ARN Largo no Codificante , Humanos , ARN Largo no Codificante/genética , Neoplasias/genética , Regulación Neoplásica de la Expresión Génica
2.
Science ; 381(6658): 660-666, 2023 Aug 11.
Artículo en Inglés | MEDLINE | ID: mdl-37561862

RESUMEN

Waste plastics are an abundant feedstock for the production of renewable chemicals. Pyrolysis of waste plastics produces pyrolysis oils with high concentrations of olefins (>50 weight %). The traditional petrochemical industry uses several energy-intensive steps to produce olefins from fossil feedstocks such as naphtha, natural gas, and crude oil. In this work, we demonstrate that pyrolysis oil can be used to produce aldehydes through hydroformylation, taking advantage of the olefin functionality. These aldehydes can then be reduced to mono- and dialcohols, oxidized to mono- and dicarboxylic acids, or aminated to mono- and diamines by using homogeneous and heterogeneous catalysis. This route produces high-value oxygenated chemicals from low-value postconsumer recycled polyethylene. We project that the chemicals produced by this route could lower greenhouse gas emissions ~60% compared with their production through petroleum feedstocks.

3.
Waste Manag ; 166: 368-376, 2023 Jul 01.
Artículo en Inglés | MEDLINE | ID: mdl-37210960

RESUMEN

Material Recovery Facilities (MRFs) are crucial players in achieving a circular economy. MRFs receive complex waste streams and separate valuable recyclables from these mixtures. This study conducts techno-economic analysis (TEA) to estimate the net present value (NPV) and life cycle assessment (LCA) to estimate different environmental impacts of a commercial scale standalone, single-stream MRF to assess the economic feasibility and environmental impacts of recovering valuable recyclables from an MRF processing 120,000 tonnes per year (t/y). The TEA employs a discounted cash flow rate of return (DCFROR) analysis over a 20-year facility lifetime, along with a sensitivity analysis on the impact of different operating and economic parameters. Results show that the total fixed cost of building the MRF facility is $23 MM, and the operating cost is $45.48/tonne. The NPV of the MRF can vary from $3.57 MM to $60 MM, while 100-year global warming potential can range from 5.98 to 8.53 kg carbon dioxide equivalents (CO2-eq) per tonne of MSW. We have also found that MSW composition (arising from regional effects) significantly impacts costs, 100-year global warming potential, and other impact categories such as acidification potential, eutrophication potential, ecotoxicity, ozone depletion, photochemical oxidation, carcinogenic effects, and non-carcinogenic effects. Sensitivity and uncertainty analysis indicate that waste composition and market prices significantly impact the profitability of the MRF, and the waste composition mostly impacts global warming potential. Our analysis also indicates that facility capacity, fixed capital cost, and waste tipping fees are vital parameters that affect the economic viability of MRF operations.


Asunto(s)
Eliminación de Residuos , Animales , Ambiente , Eliminación de Residuos/métodos , Residuos Sólidos/análisis , Incertidumbre , Estados Unidos
4.
Zhen Ci Yan Jiu ; 47(12): 1101-6, 2022 Dec 25.
Artículo en Chino | MEDLINE | ID: mdl-36571226

RESUMEN

OBJECTIVE: To observe the effect of electroacupuncture (EA) at "Zhongliao" (BL33) and "Xialiao" (BL34) on the 5-hydroxytryptamine (5-HT) signaling system in colon tissue and short-chain fatty acids in feces of rats with slow transit constipation (STC), so as to explore the underlying mechanisms of EA in the treatment of STC. METHODS: A total of 32 SD rats were randomly divided into normal, model, drug control and EA groups, with 8 rats in each group. The STC model was established by intragastric administration of loperamide for 14 days. The EA stimulation (2 Hz/15 Hz) was performed at bilateral BL33 and BL34 for 30 min, once a day for 14 days. The first black stool de-fecation time and fecal water content were detected after treatment. The expressions of 5-hydroxytryptamine 4 receptor (5-HT4R), tryptophan hydroxylase 1 (TPH1) and 5-HT transporter (SERT) in colon tissues were detected by Western blot. The contents of substance P (SP) and vasoactive intestinal peptide (VIP) in serum were detected by ELISA. The contents of 5-HT in colon tissue and short chain fatty acid (SCFA) in feces were detected by mass spectrometry. RESULTS: Compared with the normal group, the fecal water content, the expressions of 5-HT, 5-HT4R, TPH1 and SERT in colon tissue, the content of serum SP were significantly decreased (P<0.05), the first black stool de-fecation time, and the content of serum VIP was significantly increased (P<0.05), the contents of SCFA in feces were significantly decreased except isobutyric acid (P<0.05) in the model group. Compared with the model group, the fecal water content, the expressions of 5-HT, 5-HT4R, TPH1 and SERT in colon tissues, the contents of acetic acid and butyrate in feces were significantly increased (P<0.05) in the EA and drug control groups, the first black stool defecation time was decreased (P<0.05) in the EA and drug control groups, and the content of serum SP was increased and the content of serum VIP was decreased (P<0.05) in the EA group. Compared with the drug control group, the content of serum VIP was significantly decreased (P<0.05), and the expressions of TPH1 and SERT in colon tissue were significantly increased (P<0.05) in the EA group. CONCLUSION: EA at BL33 and BL34 can promote intestinal motility by intervening multiple links of 5-HT signaling system in treating STC.


Asunto(s)
Electroacupuntura , Serotonina , Ratas , Animales , Serotonina/metabolismo , Ratas Sprague-Dawley , Estreñimiento/genética , Estreñimiento/terapia , Ácidos Grasos Volátiles , Puntos de Acupuntura
5.
Front Surg ; 9: 974341, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36034382

RESUMEN

Purpose: The biomechanical characteristics of the trauma size and postoperative drainage of different incisions for high complex anal fistula surgery were compared by numerical simulation analysis to provide a theoretical basis for the clinical selection of minimally invasive incisions for surgery. Methods: Using FLUENT finite element software, a typical incision finite element model was established to obtain incision areas, and the total mass outlet flow within 200 s was calculated to evaluate the drainage effect of each incision. Results: The incisions with the largest to smallest areas were the curved, spindle, and curved plus extended groove incision, indicating that the curved plus extended groove incision caused the least damage to the perianal skin muscles. Conversely, the incisions with the largest to smallest total outlet flow were as follows: curved plus extended groove, spindle, curved, and straight incision, suggesting that the curved plus extended groove model had the best diversion effect, and the curved incision had better diversion effect than that of the straight incision. Conclusion: The curved plus extended groove surgical incision had the smallest incision area, minimized damage to the perianal skin and muscle tissue, conformed to the concept of minimally invasive surgery, ensured adequate drainage of exudate, maintained the normal growth of granulation tissue on the wound surface, preserved the original form of the anus, and thus better protected the function of the anus. This improved the quality of life of patients requiring high complex anal fistulas.

6.
Exp Ther Med ; 22(6): 1368, 2021 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-34659514

RESUMEN

Ding's herbal enema (DHEP) is a traditional Chinese medicinal therapy that has been used to treat ulcerative colitis (UC) in China. The present study determined the molecular mechanism of the effect of DHEP in UC treatment. C57BL/6J mice were treated with 3.5% (w/v) dextran sulfate sodium (DSS) for 7 days to establish an animal model of colitis. The mice were divided into five groups (n=5): Control, vehicle, DHEP, mesalazine and ß-sitosterol. After oral administration for 7 days, the body weight, disease activity index, histopathology and inflammatory factors were analyzed. The fractions of CD4+Foxp3+ regulatory T (Treg) cells and CD4+IL-17A+ T helper (Th) cells were determined by flow cytometry. Gut microbiota composition was analyzed by next-generation sequencing. The results revealed that DHEP and ß-sitosterol could significantly alleviate the symptoms of DSS-induced UC. Furthermore, the levels of IL-6, cyclooxygenase-2, TNF-α and p65 were reduced after administration of DHEP. Additionally, the data indicated that DHEP could increase the abundance of seven operational taxonomic units (OTUs) and decrease the abundance of 12 OTUs in the gut microbiota. The content of short-chain fatty acids in the colon remodeled the balance of Treg/Th17 cells in DSS-induced UC in mice. The present study preliminarily defined the mechanism of action of DHEP in UC that may be associated with the regulation of the gut microbiota composition, and maintenance of the balance between Treg and Th17 cells. Furthermore, ß-sitosterol exhibited the same effects with DHEP and it could be a possible substitute for DHEP in UC treatment.

7.
Biomed Eng Online ; 20(1): 79, 2021 Aug 06.
Artículo en Inglés | MEDLINE | ID: mdl-34362379

RESUMEN

BACKGROUND: Anterior resection syndrome (ARS) is characterized by the diverse and interchangeable evacuatory symptoms that may occur following distal colorectal resection. We aimed to investigate the effect and potential mechanisms of ozone perfusion on rats with anterior rectal resection (ARR). MATERIAL AND METHODS: After establishment of rat ARR model, 20, 40 and 80 ug/ml ozone was used to treat rats by enema administration. The pathological examination of intestinal tissue was detected using hematoxylin-eosin staining. The rate of loose stools, minimum threshold volume of abdominal withdrawal reflex (AWR) and Bristol grade were used to evaluate the degree of abnormal defecation function. Subsequently, the levels of oxidative stress- and inflammation-related markers, 5-hydroxytryptamine (5-HT), inducible nitric oxide synthase (iNOS) and nitric oxide (NO) in the serum and intestinal tissue were determined with the corresponding kits. Meanwhile, the expression of nuclear factor kappa B (NF-κB) p65, transient receptor potential vanilloid (TRPV)1, TRPV4, iNOS and 5-HT receptor 3A (5-HTR3A) was determined with RT-qPCR and western blotting. RESULTS: Ozone administration (20 and 40 ug/ml) significantly alleviated the pathological changes of intestinal tissue-induced by ARR, accompanied by the decreased loose stools rate, Bristol score and increased abdominal withdraw reflex. However, 80 ug/ml of ozone intervention played opposite roles in the aforementioned changes with 20 and 40 ug/ml of ozone. Additionally, remarkably elevated reactive oxygen species (ROS), malonaldehyde (MDA), superoxide dismutase (SOD), 5-HT, iNOS and NO levels were observed in the ozone-treated groups (20 and 40 ug/ml), while high dose of ozone drastically improved ROS, MDA, 5-HT, iNOS and NO levels but reduced the activity of SOD. Consistently, the contents of inflammatory factors were decreased after low and middle doses of ozone administration. However, high dose of ozone aggravated the inflammatory injury. Moreover, 20 and 40 ug/ml ozone upregulated TRPV1 and TRPV4 expression but downregulated 5-HTR3A expression, which was restored after 80 ug/ml of ozone intervention. Remarkably, the levels of NF-κB p65 and iNOS were dose-dependently enhanced following ozone treatment. CONCLUSIONS: Taken together, low concentration of ozone attenuated intestinal injury induced by ARR via balancing oxidative stress and inflammation, but high concentration of ozone exacerbated the intestinal injury, which might be related to the 5-HT and TRPV signaling.


Asunto(s)
Ozono , Animales , Inflamación , FN-kappa B/metabolismo , Estrés Oxidativo , Ratas , Transducción de Señal , Canales Catiónicos TRPV
8.
Guang Pu Xue Yu Guang Pu Fen Xi ; 36(3): 765-9, 2016 Mar.
Artículo en Chino | MEDLINE | ID: mdl-27400521

RESUMEN

Cytisine (Cy) is one of the alkaloids that exist naturally in the plant genera Laburnum of the family Fabaceae. With strong bioactivities, Cy is commercialized for smoking cessation for years. In this work, the study of intermolecular interactions between Cy and bovine serum albumin (BSA) was performed by applying fluorescence spectroscopic methods under simulated physiological conditions. The mechanism of fluorescence quenching of BSA by Cy was also studied. Parameters such as bathing temperature, time and solution pH were investigated to optimize the fluorescence quenching. The binding type, binding ratio and binding constant between BSA and Cy were calculated by using the Stem-Volmer equation. Experimental results indicated that Cy can quench the fluorescent emission of BSA statically by forming a 1 : 1 type non-covalent complex and the binding constant is 5.6 x 10(3) L x mol(-1). Synchronous fluorescence spectral research shows Cy may affect the fluorescence emission of Trp residues of BSA. Furthermore, molecular docking is utilized to model the complex and probe the plausible quenching mechanism. It can be noted that the hydrogen bindings and hydrophobic interactions between Cy and BSA change the micro-environment of Trp213, which leads to the fluorescence quenching of BSA.


Asunto(s)
Alcaloides/química , Simulación del Acoplamiento Molecular , Albúmina Sérica Bovina/química , Espectrometría de Fluorescencia , Azocinas/química , Interacciones Hidrofóbicas e Hidrofílicas , Quinolizinas/química
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...