Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 81
Filtrar
Más filtros

Banco de datos
País/Región como asunto
Tipo del documento
Intervalo de año de publicación
1.
Nature ; 633(8028): 109-113, 2024 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-39169191

RESUMEN

Crustal accretion at mid-ocean ridges governs the creation and evolution of the oceanic lithosphere. Generally accepted models1-4 of passive mantle upwelling and melting predict notably decreased crustal thickness at a spreading rate of less than 20 mm year-1. We conducted the first, to our knowledge, high-resolution ocean-bottom seismometer (OBS) experiment at the Gakkel Ridge in the Arctic Ocean and imaged the crustal structure of the slowest-spreading ridge on the Earth. Unexpectedly, we find that crustal thickness ranges between 3.3 km and 8.9 km along the ridge axis and it increased from about 4.5 km to about 7.5 km over the past 5 Myr in an across-axis profile. The highly variable crustal thickness and relatively large average value does not align with the prediction of passive mantle upwelling models. Instead, it can be explained by a model of buoyant active mantle flow driven by thermal and compositional density changes owing to melt extraction. The influence of active versus passive upwelling is predicted to increase with decreasing spreading rate. The process of active mantle upwelling is anticipated to be primarily influenced by mantle temperature and composition. This implies that the observed variability in crustal accretion, which includes notably varied crustal thickness, is probably an inherent characteristic of ultraslow-spreading ridges.

2.
Arch Biochem Biophys ; 755: 109960, 2024 05.
Artículo en Inglés | MEDLINE | ID: mdl-38513770

RESUMEN

Diabetes mellitus (DM) has been demonstrated to accelerate the progression of osteoarthritis (OA) by largely unknown mechanisms. Studies have shown that DM dysfunctional adipocyte-derived exosomes play a crucial role in the pathogenesis of remote organ functions. The present study aimed to clarify whether and how diabetic adipocyte-derived exosomes mediate the pathological regulation of OA. We found that intraarticular injection of DM serum exosomes in the non-diabetic mice significantly exacerbated OA injury as evidenced by a rough and fractured cartilage surface as well as increased chondrocyte apoptosis, decreased mitochondrial membrane potential (△Ψ) and increased expression of cleaved caspase-3. Mechanistic investigation identified that miR-130b-3p was significantly increased in circulating exosomes derived from DM mice and exosomes derived from HG-treated normal adipocytes, and we demonstrated that transfection of miR-130b-3p mimics significantly exacerbated the mitochondrial function of chondrocytes. Our data also indicated that miR-130b-3p impaired the △Ψ, increased cleaved caspase-3 levels, and decreased the expression of 5'-adenosine monophosphate-activated protein kinase α1 (AMPKα1), Silent mating-type information regulation 2 homolog 1 (SIRT1), and peroxisome proliferator-activated receptor gamma coactivator-1α (PGC-1α) in chondrocytes. Pharmacologic activation of AMPKα1 using AICAR reversed the â–³Ψ and catabolic responses in chondrocytes transfected with miR-130b-3p mimics. Moreover, AICAR decreased the effects of miR-130b-3p mimics on chondrocytes transfected with SIRT1-siRNA or PGC-1α-siRNA. The current study demonstrated that adipocyte-derived exosomal miR-130b-3p under DM conditions suppresses mitochondrial function in chondrocytes through targeting the AMPKα1/SIRT1/PGC1-α pathway, thus exacerbating OA injury.

3.
Arch Orthop Trauma Surg ; 144(4): 1523-1533, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38363322

RESUMEN

OBJECTIVE: To systematically analyze the effectiveness of lumbar braces in patients after lumbar spine surgery. METHODS: The databases, including PubMed, Embase, Cochrane Library, Web of Science, China National Knowledge Infrastructure (CNKI), were searched to identify the randomized controlled trials (RCTs), case-series or case-control studies on the use of lumbar braces after lumbar spine surgery. The two authors independently assessed the quality of the included study and extracted the data. The statistical analysis was performed using Revman 5.4 software. RESULTS: 9 English papers and 1 Chinese paper were included in the present work, involving a total of 2646 patients (2181 in the experimental group and 465 in the control group). The differences in preoperative VAS, postoperative VAS, preoperative ODI, postoperative ODI, length of hospital stay, postoperative complications, and surgical comparison were not statistically significant (p > 0.05). However, postoperative surgical site infection incidence was lower in the lumbar brace group than those without lumbar brace (p < 0.05). CONCLUSION: Whether or not the use of lumbar braces after lumbar fixation has a negligible impact on clinical outcomes was studied. Subsequent studies could further demonstrate whether the use of lumbar braces after lumbar surgery could reduce the incidence of surgical site infections.


Asunto(s)
Tirantes , Vértebras Lumbares , Humanos , Vértebras Lumbares/cirugía , Infección de la Herida Quirúrgica/prevención & control , Infección de la Herida Quirúrgica/epidemiología , Infección de la Herida Quirúrgica/etiología , Complicaciones Posoperatorias/epidemiología , Complicaciones Posoperatorias/prevención & control , Complicaciones Posoperatorias/etiología , Resultado del Tratamiento
4.
Biochem Cell Biol ; 101(4): 361-376, 2023 08 01.
Artículo en Inglés | MEDLINE | ID: mdl-37084412

RESUMEN

Epigenetic regulation contributes to human health and disease, especially cancer, but the mechanisms of many epigenetic regulators remain obscure. Most research is focused on gene regulatory processes, such as mRNA translation and DNA damage repair, rather than the effects on biological functions like mitochondrial activity and oxidative phosphorylation. Here, we identified an essential role for the histone chaperone structure-specific recognition protein 1 (SSRP1) in mitochondrial oxidative respiration in hepatocellular carcinoma, and found that SSRP1 suppression led to mitochondrial damage and decreased oxidative respiration. Further, we focused on TNF receptor-associated protein 1 (TRAP1), the only member of the heat shock protein 90 (HSP90) family, which directly interacts with selected respiratory complexes and affects their stability and activity. We confirmed that SSRP1 downregulation caused a decrease in TRAP1 expression at both the mRNA and protein levels. A chromatin immunoprecipitation assay also showed that SSRP1 could deposit in the TRAP1 promoter region, indicating that SSRP1 maintains mitochondrial function and reactive oxygen species levels through TRAP1. Additionally, rescue experiments and animal experiments confirmed the mechanism of SSRP1 and TRAP1 interaction. In summary, we identified a new mechanism that connects mitochondrial respiration and apoptosis, via SSRP1.


Asunto(s)
Carcinoma Hepatocelular , Neoplasias Hepáticas , Animales , Humanos , Carcinoma Hepatocelular/metabolismo , Factor 1 Asociado a Receptor de TNF/metabolismo , Chaperonas de Histonas/metabolismo , Epigénesis Genética , Neoplasias Hepáticas/metabolismo , Mitocondrias/metabolismo , Apoptosis/fisiología , Proteínas de Unión al ADN/metabolismo , Proteínas del Grupo de Alta Movilidad/metabolismo , Factores de Elongación Transcripcional/metabolismo , Proteínas HSP90 de Choque Térmico/genética , Proteínas HSP90 de Choque Térmico/metabolismo
5.
BMC Musculoskelet Disord ; 24(1): 879, 2023 Nov 11.
Artículo en Inglés | MEDLINE | ID: mdl-37951876

RESUMEN

BACKGROUND: Which types of Modic changes (MCs) and whether or how specific factors associated to MCs work on lumbar instability have yet to be well understood. The purpose of this study was to investigate the influences of the types of MCs, the extent of MCs lesion involvement, and different lumbar levels involved by MCs on lumbar instability. METHODS: This retrospective study included 263 adult subjects with MCs who underwent lumbar X-ray examinations in the neutral, flexion, and extension positions. All patients who met our inclusion criteria were examined with 1.5 Tesla magnetic resonance units. Two experienced authors with more than three-year clinical experience independently evaluated and measured the subjects' radiographic images. The subgroup analysis was performed to detect the differences in subjects' baseline characteristics and lumbar segmental motions among three types of MCs, the extent of MCs lesion involvement and different lumbar levels involved by MCs. RESULTS: There was a statistical difference in body mass index (BMI) between different involvement extent of MCs (p < 0.01), indicating that the subjects with high BMI are more likely to develop severe MCs. The subjects with Modic type 1 change (MC1) had a significant increase in lumbar angular motion than those with Modic type 2 change (MC2) and Modic type 3 change (MC3) (p < 0.01) and compared with MC3, a significant increase in lumbar translation motion was detected in subjects with MC1 and MC2 (p < 0.01). While, angular motion decreased, translation motion increased significantly as the extent of MCs lesion involvement aggravated (p < 0.01). However, there were no statistical differences in lumbar angular and translation motions between different lumbar levels involved by MCs (p > 0.05). CONCLUSIONS: Higher BMI might be a risk factor for the development of severe MCs. MC1 and MC2 significantly contribute to lumbar instability. The extents of MCs lesion involvement are strongly associated with lumbar instability. However, different lumbar levels involved by MCs have little effect on lumbar stability.


Asunto(s)
Degeneración del Disco Intervertebral , Inestabilidad de la Articulación , Enfermedades de la Columna Vertebral , Adulto , Humanos , Estudios Retrospectivos , Enfermedades de la Columna Vertebral/patología , Región Lumbosacra/patología , Imagen por Resonancia Magnética/métodos , Factores de Riesgo , Inestabilidad de la Articulación/diagnóstico por imagen , Inestabilidad de la Articulación/patología , Vértebras Lumbares/diagnóstico por imagen , Vértebras Lumbares/patología , Degeneración del Disco Intervertebral/patología
6.
J Environ Sci (China) ; 125: 603-615, 2023 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-36375942

RESUMEN

Wuhan Tianhe International Airport (WUH) was suspended to contain the spread of COVID-19, while Shanghai Hongqiao International Airport (SHA) saw a tremendous flight reduction. Closure of a major international airport is extremely rare and thus represents a unique opportunity to straightforwardly observe the impact of airport emissions on local air quality. In this study, a series of statistical tools were applied to analyze the variations in air pollutant levels in the vicinity of WUH and SHA. The results of bivariate polar plots show that airport SHA and WUH are a major source of nitrogen oxides. NOx, NO2 and NO diminished by 55.8%, 44.1%, 76.9%, and 40.4%, 33.3% and 59.4% during the COVID-19 lockdown compared to those in the same period of 2018 and 2019, under a reduction in aircraft activities by 58.6% and 61.4%. The concentration of NO2, SO2 and PM2.5 decreased by 77.3%, 8.2%, 29.5%, right after the closure of airport WUH on 23 January 2020. The average concentrations of NO, NO2 and NOx scatter plots at downwind of SHA after the lockdown were 78.0%, 47.9%, 57.4% and 62.3%, 34.8%, 41.8% lower than those during the same period in 2018 and 2019. However, a significant increase in O3 levels by 50.0% and 25.9% at WUH and SHA was observed, respectively. These results evidently show decreased nitrogen oxides concentrations in the airport vicinity due to reduced aircraft activities, while amplified O3 pollution due to a lower titration by NO under strong reduction in NOx emissions.


Asunto(s)
Contaminantes Atmosféricos , Contaminación del Aire , COVID-19 , Humanos , Aeropuertos , Emisiones de Vehículos/análisis , Dióxido de Nitrógeno/análisis , COVID-19/epidemiología , China , Control de Enfermedades Transmisibles , Contaminación del Aire/análisis , Contaminantes Atmosféricos/análisis , Aeronaves , Óxidos de Nitrógeno/análisis , Monitoreo del Ambiente/métodos , Material Particulado/análisis
7.
Opt Express ; 30(19): 33588-33602, 2022 Sep 12.
Artículo en Inglés | MEDLINE | ID: mdl-36242390

RESUMEN

Based on actual atmospheric observations of internal mixing of light-absorbing brown carbon (BrC)-coated black carbon (BC), the optical properties of mixed black and brown carbon aerosols (BBC) were calculated using four mixing models (external mixing, core-shell, Bruggeman, and Maxwell-Garnett models), and changes in their optical properties with wavelength were compared and analyzed. Under the assumption of different volumetric mixing ratios (VR=VBC/VBBC), there is little difference in volumetric absorptive coefficient (Kab) of BBC in these models in the ultraviolet band where both BC and BrC have strong absorption, particularly in the ultraviolet A band. In visible and near-infrared bands, the three internal mixing models significantly reduce the single scattering albedo compared to the external mixing scenario. In addition, the widely used core-shell model was used to evaluate the effects of BrC shell thickness and environmental relative humidity (RH) on the optical properties of BBC. The impacts of these factors are mainly seen in ultraviolet and visible bands. The volumetric extinction coefficient (Kex) decreases with BrC shell thickness under a fixed BC core radius (0.12 µm) in these bands. This is because the radiation reaching the surface of BC particles is reduced under the absorption of less efficient BrC shells (known as the blocking effect), which is different from the BC and light-scattering aerosols internal mixing scenario. Moreover, the Kex and Kab of BBC decrease with RH, which is mainly due to both the increasing thickness of the BrC shell and the change in the complex refractive index of the BrC shell. Based on the assumptions of unchanged BC core parameters and actual observations, the extinction ability increases when BrC particles are more light-scattering in the ultraviolet and visible bands. The increase in extinction is mainly from scattering, rather than absorption. However, the situation is the opposite in the near-infrared band.

8.
Exp Cell Res ; 407(1): 112799, 2021 10 01.
Artículo en Inglés | MEDLINE | ID: mdl-34461110

RESUMEN

Colorectal cancer (CRC) is the leading deadly cancer worldwide. Gene associated with retinoid-IFN-induced mortality-19 (GRIM-19), a novel tumor suppressor, has been reported to be expressed at low levels in human CRC. However, the role of GRIM-19 in CRC progression and the corresponding detailed mechanisms are unclear. The results of this study indicated that GRIM-19 expression is related to CRC progression. Overexpression of GRIM-19 was found to inhibit CRC cell proliferation and induce apoptosis in vitro and in vivo. Our results demonstrated that GRIM-19 suppresses CRC through posttranslational regulation of p53, in which SIRT7 is activated by GRIM-19 and triggers PCAF-mediated MDM2 ubiquitination, eventually stabilizing the p53 protein. We also observed that GRIM-19 enhances the effect of oxaliplatin against CRC. In conclusion, GRIM-19 plays an important role in CRC development and is a potential biomarker and therapeutic target for clinical treatment of CRC.


Asunto(s)
Proteínas Reguladoras de la Apoptosis/metabolismo , Apoptosis/fisiología , Proliferación Celular/fisiología , Neoplasias Colorrectales/metabolismo , NADH NADPH Oxidorreductasas/metabolismo , Proteína p53 Supresora de Tumor/metabolismo , Línea Celular Tumoral , Neoplasias Colorrectales/patología , Regulación Neoplásica de la Expresión Génica/fisiología , Genes Supresores de Tumor/fisiología , Humanos , Proteínas Proto-Oncogénicas c-mdm2/metabolismo , Sirtuinas/metabolismo , Ubiquitinación/fisiología
9.
BMC Surg ; 22(1): 18, 2022 Jan 16.
Artículo en Inglés | MEDLINE | ID: mdl-35034603

RESUMEN

BACKGROUND: Tetralogy of Fallot (TOF) is one of the most common cyanotic congenital heart diseases. Pulmonary regurgitation is the most common and severe comorbidity after transannular patch (TAP) repair of TOF patients. It has not been confirmed whether a TAP repair with monocusp valve reconstruction would benefit TOF patients in perioperative period compared to those without monocusp valve reconstruction. The purpose of the study is to review and analyze all clinical studies that have compared perioperative outcomes of TOF patients undergoing TAP repair with or without monocusp valve reconstruction and conduct a preferable surgery. METHODS: Eligible studies were identified by searching the electronic databases. The year of publication of studies was restricted from 2000 till present. The primary outcome was perioperative mortality, and secondary outcomes included cardiopulmonary bypass time, aortic cross-clamp time, ventilation duration, ICU length of stay, hospital length of stay, perioperative right ventricular outflow tract (RVOT) pressure gradient, and moderate or severe pulmonary regurgitation (PR). The meta-analysis and forest plots were drawn using Review Manager 5.3. Statistically significant was considered when p-value ≤ 0.05. RESULTS: Eight studies were included which consisted of 8 retrospective cohort study and 2 randomized controlled trial. The 10 studies formed a pool of 526 TOF patients in total, in which are 300 undergoing TAP repair with monocusp valve reconstruction (monocusp group) compared to 226 undergoing TAP repair without monocusp valve reconstruction (non-monocusp group). It demonstrated no significant differences between two groups in perioperative mortality (OR = 0.69, 95% CI 0.20-2.41, p = 0.58). It demonstrated significant differences in perioperative cardiopulmonary bypass time (minute, 95% CI 17.93-28.42, p < 0.00001), mean length of ICU stay (day, 95% CI - 2.11-0.76, p < 0.0001), and the degree of perioperative PR (OR = 0.03, 95% CI 0.010.12, p < 0.00001). Significant differences were not found in other secondary outcomes. CONCLUSION: Transannular patch repair with monocusp valve reconstruction have significant advantages on decreasing length of ICU stay and reducing degree of PR for TOF patients. Large, multicenter, randomized, prospective studies which focuse on perioperative outcomes and postoperative differences based on long-term follow-up between TAP repair with and without monocusp valve reconstruction are needed.


Asunto(s)
Insuficiencia de la Válvula Pulmonar , Válvula Pulmonar , Tetralogía de Fallot , Humanos , Lactante , Estudios Multicéntricos como Asunto , Estudios Prospectivos , Válvula Pulmonar/cirugía , Estudios Retrospectivos , Tetralogía de Fallot/cirugía , Resultado del Tratamiento
10.
Yi Chuan ; 43(5): 442-458, 2021 May 20.
Artículo en Inglés | MEDLINE | ID: mdl-33972215

RESUMEN

In order to develop a variety of japonica rice with good eating quality suitable for planting in Jiangsu Province, the genetic basis of high quality, disease resistance and high yield japonica rice varieties in Jiangsu Province was systematically studied. The relationship among different rice qualities of cooking, nutrition, and eating was studied by association analysis. It was clear that amylose content was the key factor affecting eating quality. The semi waxy rice with amylose content of 10%~14% has bright surface, soft texture, and elasticity, combining the softness of glutinous rice and the elasticity of japonica rice. The cold rice is not hard, and the taste is excellent. It meets the taste requirements of people in Yangtze River Delta region who like to eat soft fragrant japonica rice. The semi waxy japonica rice variety "Kantou 194" with a low expression of amylose content gene Wx mp and an amylose content of about 10% was selected as the core germplasm for improving eating quality. Pyramiding breeding of japonica rice variety with good eating quality, disease resistance and high yield was carried out by examining the development of Wx mp gene molecular markers and the use of closely linked molecular markers with disease resistance and high yield genes. A series of new japonica rice varieties with good taste such as Nanjing 46, Nanjing 5055, Nanjing 9108, and Nanjing 5718, suitable for different rice areas of Jiangsu Province, have been bred and approved by Jiangsu Provincial Variety Approval Committee. The layout of japonica rice varieties with good taste covering different rice areas in Jiangsu Province has been formed. These varieties have been planted with an accumulated area of more than 5.3 million hectares, which has effectively promoted the development of high quality rice industry in Jiangsu Province and its surrounding areas, and made important contributions to the structural adjustment of the supply side of rice industry, improving quality and efficiency, and ensuring food security.


Asunto(s)
Oryza , Amilosa , Marcadores Genéticos , Humanos , Oryza/genética , Fitomejoramiento
11.
Ecotoxicol Environ Saf ; 148: 393-401, 2018 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-29100157

RESUMEN

Triclosan (TCS) is an antibacterial and antifungal agent widely used in personal care products (PCPs). We investigated the effects of TCS (20µg/L, 100µg/L and 500µg/L) on Chlamydomonas reinhardtii by measuring the algal growth, chlorophyll content, lipid peroxidation, and transcription of the antioxidant-related genes (superoxide dismutase (SOD), glutathione peroxidase (GPX), catalase (CAT), glutathione S-transferase (GST), plastid terminal oxidase 2 (PTOX) and thioredoxin (TRX)) as well as biochemical alterations. The results showed significant dose-related effects of TCS on the algal species in terms of growth and chlorophyll content. Malondialdehyde (MDA) increased with increasing TCS concentrations and showed significant difference between the treatment of 405.3µg/L TCS and control group. Transcription analysis revealed that the expression of SOD mRNA was most sensitive to TCS among the selected genes. In addition, Fourier-transform infrared spectroscopy showed time- and concentration-specific biochemical responses in C. reinhardtii when exposed to TCS. The biochemical alterations associated with different doses of TCS were mainly attributed to structural changes associated with lipid, protein, nucleic acid and carbohydrate. The findings from this study reveal that TCS in the aquatic environment may affect algal growth, chlorophyll synthesis, oxidative stress responses and cause biochemical alterations. This study provided important information to achieve a better understanding of the toxic mechanism of triclosan on algae Chlamydomonas reinhardtii.


Asunto(s)
Chlamydomonas reinhardtii/efectos de los fármacos , Triclosán/toxicidad , Contaminantes Químicos del Agua/toxicidad , Antioxidantes/metabolismo , Catalasa/genética , Catalasa/metabolismo , Chlamydomonas reinhardtii/enzimología , Chlamydomonas reinhardtii/genética , Chlamydomonas reinhardtii/metabolismo , Clorofila/metabolismo , Glutatión Peroxidasa/genética , Glutatión Peroxidasa/metabolismo , Glutatión Transferasa/genética , Glutatión Transferasa/metabolismo , Peroxidación de Lípido/efectos de los fármacos , Malondialdehído/metabolismo , Estrés Oxidativo/efectos de los fármacos , Superóxido Dismutasa/genética , Superóxido Dismutasa/metabolismo , Transcripción Genética/efectos de los fármacos
12.
Zhongguo Zhong Yao Za Zhi ; 43(5): 926-933, 2018 Mar.
Artículo en Zh | MEDLINE | ID: mdl-29676089

RESUMEN

This article is aimed to study the response mechanism of Acanthopanax giraldii on different shading intensity to guide its artificial cultivation. The cultivated A. giraldii in Maoxian was used as the research object, set up different shading treatment groups, analyzed photosynthesis, physiology, submicroscopic structure to explore the response mechanism of A. giraldii to different light intensity. Light was the main influencing factor to photosynthetic rate.During morning and afternoon periods,the Pn of the CK group reduced by stomatal limitation and non stomatal limitation factors respectively. While during 14:30-18:30 period, the Pn of A1 and A2 groups reduced by non stomatal limitation factors.LSP, LCP and Rd of A1 and A2 groups were significantly lower than those of CK group;The content of SS and SP of A1 and A2 groups were lower than those of CK group. The content of Pro of CK group were significantly higher than those of group A2.The activities of SOD and POD of them was higher than that of CK group,CAT activity of A1 and POD activity of A2 were relatively higher In their respective free radical scavenging system. Starch grain increased and base grana declined in the chloropalst of those group CK. The study results indicated that response mechanism of different shading conditions of A. giraldii under field cultivation conditions. Its could effectively adapt to environmental changes of the home cultivation,which provided a reference for ensuring yield and quality.


Asunto(s)
Eleutherococcus/fisiología , Eleutherococcus/efectos de la radiación , Luz , Fotosíntesis , Hojas de la Planta/fisiología , Hojas de la Planta/efectos de la radiación
13.
Sheng Wu Yi Xue Gong Cheng Xue Za Zhi ; 35(5): 733-739, 2018 10 25.
Artículo en Zh | MEDLINE | ID: mdl-30370712

RESUMEN

The performance of intelligent prosthetic knee has an important effect on the realization of physiological gait of transfemoral amputees. A new type of single axis hydraulic damping knee prosthesis was designed based on the analysis of physiological gait. The training methods of the stance and swing phase were proposed. Knee prosthesis test was done through simulation and measurement device. The control target of peak flexion angle during swing of knee prosthesis is chosen to be 60-70°. When the damper valve closure was 0%, maximum swing-phase knee flexion angle of knee prosthesis were (86±2)°, (91±3)° and (97±3)° with the speed of 0.8 m/s, 1.2 m/s and 1.8 m/s, respectively. Once the valve closure was changed, maximum swing-phase knee flexion angle with different speeds could be adjusted between 60° and 70° and the required valve closure percentage were separately 25%, 40% and 70%. The damping adjustment law of intelligent knee prosthesis to achieve physiological gait was revealed.

14.
Artículo en Inglés | MEDLINE | ID: mdl-28394701

RESUMEN

This study aims to investigate nitrogen removal and its relationship with the nitrogen-cycle genes and microorganisms in the horizontal subsurface flow constructed wetlands (CWs) with different design parameters. Twelve mesocosm-scale CWs with four substrates and three hydraulic loading rates were set up in the outdoor. The result showed the CWs with zeolite as substrate and HLR of 20 cm/d were selected as the best choice for the TN and NH3-N removal. It was found that the single-stage mesocosm-scale CWs were incapable to achieve high removals of TN and NH3-N due to inefficient nitrification process in the systems. This was demonstrated by the lower abundance of the nitrification genes (AOA and AOB) than the denitrification genes (nirK and nirS), and the less diverse nitrification microorganisms than the denitrification microorganisms in the CWs. The results also show that microorganism community structure including nitrogen-cycle microorganisms in the constructed wetland systems was affected by the design parameters especially the substrate type. These findings show that nitrification is a limiting factor for the nitrogen removal by CWs.


Asunto(s)
Genes Bacterianos , Ciclo del Nitrógeno/genética , Nitrógeno/análisis , Eliminación de Residuos Líquidos/métodos , Aguas Residuales , Humedales , Bacterias/genética , Bacterias/metabolismo , Desnitrificación/genética , Consorcios Microbianos/genética , Nitrificación/genética , Nitrógeno/metabolismo , Aguas Residuales/química , Aguas Residuales/microbiología
16.
Small ; 11(19): 2284-90, 2015 May 20.
Artículo en Inglés | MEDLINE | ID: mdl-25641852

RESUMEN

Rational control of molecular ordering on surfaces and interfaces is vital in supramolecular chemistry and nanoscience. Here, a systematic scanning tunneling microscopy (STM) study for controlling the self-assembly behavior of alkoxylated benzene (B-OC(n)) molecules on a HOPG surface is presented. Three different phases have been observed and, of great importance, they can transform to each other by modifying the solute concentration. Further studies, particularly in situ diluting and concentrating experiments, demonstrate that the transitions among the three phases are highly controllable and reversible, and are driven thermodynamically. In addition, it is found that concentration-controlled reversible phase transitions are general for different chain lengths of B-OC(n) molecules. Such controllable and reversible phase transitions may have potential applications in the building of desirable functional organic thin films and provide a new understanding in thermodynamically driven self-assembly of organic molecules on surfaces and interfaces.

17.
Dermatol Surg ; 40(4): 420-6, 2014 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-24446755

RESUMEN

BACKGROUND: Vitiligo is an acquired skin disorder with great social impact. It can be successfully treated using cultured autologous melanocytes transplantation. OBJECTIVE: To evaluate the effect of different modalities of narrow-band ultraviolet B (NB-UVB) therapy on the outcome of cultured autologous melanocyte transplantation in treating vitiligo. METHODS: Patients undergoing cultured autologous melanocyte transplantation were randomly assigned to four different study groups. Group 1 underwent 20 sessions of NB-UVB treatment before transplantation; Group 2 underwent 30 sessions of NB-UVB treatment after transplantation; Group 3 underwent 20 sessions of NB-UVB treatment before transplantation and 30 sessions after transplantation; Group 4 underwent only transplantation. RESULTS: Four hundred thirty-seven patients were enrolled. Group 3 responded best, more than 90% repigmentation was achieved in 81.3% of patients, and 94.8% patients experienced 50% or greater repigmentation. Statistical analysis showed that there was a highly significant difference between the four groups (χ(2) = 35.56, p < .001). Homogeneous skin color was obtained on the repigmentation areas, and no scarring or other serious side effects were observed. CONCLUSIONS: Cultured autologous melanocyte transplantation is an effective treatment for stable vitiligo. Combination of NB-UVB therapy with melanocyte transplantation can accelerate repigmentation of transplanted vitiliginous areas, especially if NB-UVB is given before and after transplantation.


Asunto(s)
Melanocitos/trasplante , Terapia Ultravioleta/métodos , Vitíligo/terapia , Adolescente , Adulto , Niño , Preescolar , Femenino , Humanos , Masculino , Persona de Mediana Edad , Trasplante Autólogo , Adulto Joven
18.
Zhongguo Zhong Xi Yi Jie He Za Zhi ; 34(11): 1335-41, 2014 Nov.
Artículo en Zh | MEDLINE | ID: mdl-25566625

RESUMEN

OBJECTIVE: To observe the effect of pungent dispersion bitter purgation method (PDBPM) on the esophageal mucosal intercellular space of reflux esophagitis (RE) model rats. METHODS: Totally 100 Wistar rats were randomly divided into the control group, the model group, the Western medicine group (WM), the Chinese medicine group (CM), 25 rats in each group. Rats in the control group only received switch operation. Rats in the rest three groups received modified partial cardia muscle incision combined pylorus ligation of external parts to prepare the RE rat model. Starting from the 3rd day after operation, WM mixture (Motilium 3. 2 mg/kg + Omeprazole Capsule 4.3 mg/kg + Hydrotalcite Tablet 161.4 mg/kg) was administered by gastrogavage to rats in the WM group. Rats in the CM group was administered by gastrogavage with Modified Banxia Xiexin Decoction (5.7 g/kg), 2.5 mL each time, twice daily for 14 consecutive days. Equal volume of normal saline was administered by gastrogavage to rats in the control group and the model group. On day 7 and 14, the lower esophagus pH value, general specimen of mucosa and histopathologic changes were observed. Intercellular spaces of esophageal epithelium were measured for a control study. RESULTS: Compared with the same group at day 7, the lower esophagus pH value increased at day 14 (P < 0.01); the naked eye integral of esophageal mucosa and intercellular spaces of esophageal epithelium also decreased at day 14 in the CM group and the WM group (P < 0.05). Compared with the control group at the same time point, the lower esophagus pH value decreased in the model group (P < 0.01). The naked eye integral of esophageal mucosa, and intercellular spaces of esophageal epithelium increased in the model group with increased intercellular spaces (P < 0.01). Compared with the model group at the same time point, the lower esophagus pH value increased and the naked eye integral of esophageal mucosa decreased in the CM group and the WM group at day 7 and 14 (P < 0.01). Intercellular spaces of esophageal epithelium of RE model rats at day 14 was lower in the CM group and the WM group than in the model group (P < 0.01). Compared with the WM group, the lower esophagus pH value decreased at day 7 in the CM group (P < 0.05); the naked eye integral of esophageal mucosa and intercellular spaces of esophageal epithelium decreased at day 14 in the CM group (P < 0.05). CONCLUSIONS: PDBPM had favorable treatment effect on RE model rats. The therapeutic effect was more obvious along with the therapeutic course went by. Its mechanism might be achieved through good repair effect on damaged mucosa, increasing the pressure of esophageal sphincter, and inhibiting gastric acid.


Asunto(s)
Medicamentos Herbarios Chinos/farmacología , Esofagitis Péptica/tratamiento farmacológico , Animales , Antiulcerosos/farmacología , Antiulcerosos/uso terapéutico , Medicamentos Herbarios Chinos/uso terapéutico , Espacio Extracelular , Mucosa Bucal , Omeprazol/uso terapéutico , Ratas , Ratas Wistar
19.
Orthopedics ; 47(4): e167-e173, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38690847

RESUMEN

BACKGROUND: The objectives of this research were to establish an animal model of adjacent segment degeneration (ASD) bordering lumbar fusion and to investigate the expression of autophagy factors in nucleus pulposus cells of adjacent intervertebral disks. MATERIALS AND METHODS: Twenty-four adult New Zealand white rabbits were enrolled and divided into two groups: group A (n=12) and group B (n=12). Posterolateral fusion and fixation were performed after intervertebral disk degeneration occurred in group A, and the rabbits were monitored for 6 months. Group B was the control group and did not undergo fusion surgery. These rabbits were monitored for 6 months. Real-time quantitative polymerase chain reaction and immunohistochemistry were performed to detect the mRNA and protein expressions of PTEN-induced kinase 1 (PINK1), Parkin, ADAMTS-4, and MMP-3. An external database, the GEO database, was used to examine the expression of these genes and analyze them for differential expression. RESULTS: After lumbar fusion in rabbits, the animal model of ASD exhibited gradual degeneration of adjacent intervertebral disks over time. Group A displayed significantly higher mRNA and protein expressions of PINK1 and MMP-3 but lower expression of ADAMTS-4 compared with group B (P<.05). The results analyzed in the GEO database showed that the expression of PINK1 was higher in group A than in group B, while the expression of ADAMTS-4 was lower in group A than in group B. CONCLUSION: After posterolateral lumbar fusion in rabbits, the animal ASD model showed gradual deterioration of adjacent intervertebral disks with prolonged follow-up. The findings indicate the important role of autophagy in the apoptosis of nucleus pulposus cells in adjacent intervertebral disks. [Orthopedics. 2024;47(4):e167-e173.].


Asunto(s)
Autofagia , Modelos Animales de Enfermedad , Degeneración del Disco Intervertebral , Vértebras Lumbares , Núcleo Pulposo , Fusión Vertebral , Animales , Conejos , Núcleo Pulposo/metabolismo , Núcleo Pulposo/patología , Degeneración del Disco Intervertebral/metabolismo , Degeneración del Disco Intervertebral/patología , Degeneración del Disco Intervertebral/genética , Autofagia/fisiología , Vértebras Lumbares/cirugía , Vértebras Lumbares/patología , Proteína ADAMTS4/metabolismo , Proteína ADAMTS4/genética , Ubiquitina-Proteína Ligasas/genética , Ubiquitina-Proteína Ligasas/metabolismo , Proteínas Quinasas/metabolismo , Proteínas Quinasas/genética , Metaloproteinasa 3 de la Matriz/metabolismo , Metaloproteinasa 3 de la Matriz/genética , Masculino
20.
Sci Total Environ ; 923: 171353, 2024 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-38432390

RESUMEN

Black carbon (BC) exerts a profound and intricate impact on both air quality and climate due to its high light absorption. However, the uncertainty in representing the absorption enhancement of BC in climate models leads to an increased range in the modeled aerosol climate effects. Changes in BC optical properties could result either from atmospheric aging processes or from variations in its sources. In this study, a source-age model for identifying emission sources and aging states presented by University of California at Davis/California Institute of Technology (UCD/CIT) was used to simulate the atmospheric age distribution of BC from different sources and to quantify its impact on the optical properties of BC-containing particles. The results indicate that regions with greater aged BC concentrations do not correspond to regions with higher BC emissions due to atmospheric transport. High concentrations of aged BC are found in northern Yangtze River Delta (YRD) regions during summer. The chemical compositions of particles from different sources and with different atmospheric ages differ significantly. BC and primary organic aerosols (POA) are dominating in Traffic-dominated source while other components dominate in Industry-dominated source. As the atmospheric age increases, the mass fraction of secondary inorganic aerosols rises. Compared to the original model, the simulated mass absorption cross section of BC particles in the source-age model decreases while the single scattering albedo increases. This compensates for ~11 % of the overestimation of the simulated BC direct radiative forcing. Our study highlights that incorporating atmospheric age and source information into models can greatly improve the estimation of optical properties of BC-containing particles and deepen our understanding of their climate effects.

SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA