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1.
J Environ Sci (China) ; 139: 84-92, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38105080

RESUMEN

Additives could improve composting performance and reduce gaseous emission, but few studies have explored the synergistic of additives on H2S emission and compost maturity. This research aims to make an investigation about the effects of chemical additives and mature compost on H2S emission and compost maturity of kitchen waste composting. The results showed that additives increased the germination index value and H2S emission reduction over 15 days and the treatment with both chemical additives and mature compost achieved highest germination index value and H2S emission reduction (85%). Except for the treatment with only chemical additives, the total sulfur content increased during the kitchen waste composting. The proportion of effective sulfur was higher with the addition of chemical additives, compared with other groups. The relative abundance of H2S-formation bacterial (Desulfovibrio) was reduced and the relative abundance of bacterial (Pseudomonas and Paracoccus), which could convert sulfur-containing substances and H2S to sulfate was improved with additives. In the composting process with both chemical additives and mature compost, the relative abundance of Desulfovibrio was lowest, while the relative abundance of Pseudomonas and Paracoccus was highest. Taken together, the chemical additives and mature compost achieved H2S emission reduction by regulating the dynamics of microbial community.


Asunto(s)
Compostaje , Microbiota , Suelo/química , Gases , Azufre
2.
Opt Express ; 31(2): 2931-2941, 2023 Jan 16.
Artículo en Inglés | MEDLINE | ID: mdl-36785295

RESUMEN

In this work, by using three-dimensional finite-difference time-domain (3D FDTD) method, the effect of conventional nano-patterned sapphire substrate (NPSS) on the optical crosstalk and the light extraction efficiency (LEE) for InGaN/GaN-based flip-chip micro light-emitting diodes (µ-LEDs) are systematically studied. We find that the conventional NPSS is not suitable for µ-LEDs. It is because the inclined mesa sidewall for µ-LEDs possesses a good scattering effect for µ-LEDs, but the introduced conventional NPSS causes part of the light be off escape cone between sapphire and air and become the guided light. To suppress the guided light and improve the optical crosstalk, a thick air layer between the n-GaN layer and the sapphire substrate can be used as a light filter to prevent the guided light from propagating into the sapphire. However, in reality, it is challenging to make the aforementioned air layer from point of fabrication view. Therefore, we propose the air-cavity patterned sapphire substrate (AC-PSS) as the light filter. Our results show that the crosstalk ratio can be decreased to the value even lower than 10%. The LEE can also be enhanced simultaneously due to combination effects of the filtering effect of the AC-PSS and the scattering effect of the inclined mesa sidewall.

3.
Opt Lett ; 48(22): 5863-5866, 2023 Nov 15.
Artículo en Inglés | MEDLINE | ID: mdl-37966738

RESUMEN

In this Letter, beveled mesas for 30 × 30 µm2 GaN-based micro-light-emitting diodes (µLEDs) with different inclination angles are designed, fabricated, and measured. We find that µLED with a mesa inclination angle of 28° has the lowest internal quantum efficiency (IQE) and the highest injection current density at which the peak IQE is obtained. This is due to the increased quantum confined Stark effect (QCSE) at the mesa edge. The increased QCSE results from the strong electric field coupling effect. Instead of radiative recombination, more nonradiative recombination and leakage current will be generated in the sidewall regions. Besides, the smallest angle (28°) also produces the lowest light extraction efficiency (LEE), which arises from the optical loss caused by the sidewall reflection at the beveled surface sides. Therefore, the inclination angle for the beveled mesa has to be increased to 52° and 61° by using Ni and SiO2 as hard masks, respectively. Experimental and numerical results show that the external quantum efficiency (EQE) and the optical power can be enhanced for the fabricated devices. Meanwhile, the reduced surface recombination rate also decreases the leakage current.

4.
Appl Opt ; 62(13): 3431-3438, 2023 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-37132844

RESUMEN

In this paper, by using advanced numerical models, we investigate the impact of the AlN/GaN distributed Bragg reflector (DBR) and AlInN/GaN DBR on stimulated radiative recombination for GaN-based vertical-cavity-surface-emitting lasers (VCSELs). According to our results, when compared with the VCSEL with AlN/GaN DBR, we find that the VCSEL with AlInN/GaN DBR decreases the polarization-induced electric field in the active region, and this helps to increase the electron-hole radiative recombination. However, we also find that the AlInN/GaN DBR has a reduced reflectivity when compared with the AlN/GaN DBR with the same number of pairs. Furthermore, this paper suggests that more pairs of AlInN/GaN DBR will be set, which helps to even further increase the laser power. Hence, the 3 dB frequency can be increased for the proposed device. In spite of the increased laser power, the smaller thermal conductivity for AlInN than AlN results in the earlier thermal droop in the laser power for the proposed VCSEL.

5.
Opt Express ; 30(21): 37675-37685, 2022 Oct 10.
Artículo en Inglés | MEDLINE | ID: mdl-36258351

RESUMEN

In this report, the impact of different mesa designs on the optical and electrical characteristics for GaN-based micro-light emitting diodes (µLEDs) has been systematically and numerically investigated by using TCAD simulation tools. Our results show that an enhanced light extraction efficiency can be obtained by using beveled mesas. The inclined mesa angles can more effectively reflect the photons to the substrate, and this helps to extract the photons to free air for flip-chip µLEDs. However, it is found that the current injection is influenced by inclination angles for the investigated µLEDs, such that the beveled mesas make stronger charge-coupling effect and increase the electric field magnitude in the multiple quantum wells at the mesa edge, so that the carriers cannot be effective consumed by radiative recombination. As a result, this gives rise to stronger defect-induced nonradiative recombination at mesa surfaces. Therefore, there are tradeoffs between the LEEs and IQEs when changing the beveled angle, to maximize external quantum efficiency for GaN-based µLEDs, the beveled mesa angle shall be carefully designed and optimized.

6.
Opt Express ; 29(19): 29651-29660, 2021 Sep 13.
Artículo en Inglés | MEDLINE | ID: mdl-34614706

RESUMEN

In this report, we investigate the impact of a thin p-GaN layer on the efficiency for AlGaN-based deep-ultraviolet light-emitting diodes (DUV LEDs). According to our results, the light extraction efficiency (LEE) becomes higher with the decrease of the p-GaN layer thickness, which can be ascribed to the decreased absorption of DUV emission by the thin p-GaN layer. Moreover, we also find that the variation trend of external quantum efficiency (EQE) is consistent with that of LEE. Therefore, we can speculate that high-efficiency DUV LEDs can be achieved by using thin p-GaN layer to increase the LEE. However, a thin p-GaN layer can also cause severe current crowding effect and the internal quantum efficiency (IQE) will be correspondingly reduced, which will restrict the improvement of EQE. In this work, we find that the adoption of a current spreading layer for such DUV LED with very thin p-GaN layer can facilitate the current spreading effect. For the purpose of demonstration, we then utilize a well-known p-AlGaN/n-AlGaN/p-AlGaN (PNP-AlGaN) structured current spreading layer. Our experimental and numerical results show that, as long as the current crowding effect can be suppressed, the DUV LED with thin p-GaN layer can significantly increase the EQE and the optical power thanks to the enhanced LEE.

7.
Opt Express ; 29(20): 31201-31211, 2021 Sep 27.
Artículo en Inglés | MEDLINE | ID: mdl-34615218

RESUMEN

Due to the increased surface-to-volume ratio, the surface recombination caused by sidewall defects is a key obstacle that limits the external quantum efficiency (EQE) for GaN-based micro-light-emitting diodes (µLEDs). In this work, we propose selectively removing the periphery p+-GaN layer so that the an artificially formed resistive ITO/p-GaN junction can be formed at the mesa edge. Three types of LEDs with different device dimensions of 30 × 30 µm2, 60 × 60 µm2 and 100 × 100 µm2 are investigated, respectively. We find that such resistive ITO/p-GaN junction can effectively prevent the holes from reaching the sidewalls for µLEDs with smaller size. Furthermore, such confinement of injection current also facilitates the hole injection into the active region for µLEDs. Therefore, the surface-defect-caused nonradiative recombination in the edge of mesa can be suppressed. Meantime, a reduction of current leakage caused by the sidewall defects can also be obtained. As a result, the measured and calculated external quantum efficiency (EQE) and optical output power for the proposed LED with small sizes are increased.

8.
Acta Pharmacol Sin ; 42(5): 832-842, 2021 May.
Artículo en Inglés | MEDLINE | ID: mdl-33824461

RESUMEN

Nanomedicine has attracted increasing attention and emerged as a safer and more effective modality in cancer treatment than conventional chemotherapy. In particular, the distinction of tumor microenvironment and normal tissues is often used in stimulus-responsive drug delivery systems for controlled release of therapeutic agents at target sites. In this study, we developed mesoporous silica nanoparticles (MSNs) coated with polyacrylic acid (PAA), and pH-sensitive lipid (PSL) for synergistic delivery and dual-pH-responsive sequential release of arsenic trioxide (ATO) and paclitaxel (PTX) (PL-PMSN-PTX/ATO). Tumor-targeting peptide F56 was used to modify MSNs, which conferred a target-specific delivery to cancer and endothelial cells under neoangiogenesis. PAA- and PSL-coated nanoparticles were characterized by TGA, TEM, FT-IR, and DLS. The drug-loaded nanoparticles displayed a dual-pH-responsive (pHe = 6.5, pHendo = 5.0) and sequential drug release profile. PTX within PSL was preferentially released at pH = 6.5, whereas ATO was mainly released at pH = 5.0. Drug-free carriers showed low cytotoxicity toward MCF-7 cells, but ATO and PTX co-delivered nanoparticles displayed a significant synergistic effect against MCF-7 cells, showing greater cell-cycle arrest in treated cells and more activation of apoptosis-related proteins than free drugs. Furthermore, the extracellular release of PTX caused an expansion of the interstitial space, allowing deeper penetration of the nanoparticles into the tumor mass through a tumor priming effect. As a result, FPL-PMSN-PTX/ATO exhibited improved in vivo circulation time, tumor-targeted delivery, and overall therapeutic efficacy.


Asunto(s)
Antineoplásicos/uso terapéutico , Trióxido de Arsénico/uso terapéutico , Neoplasias de la Mama/tratamiento farmacológico , Portadores de Fármacos/química , Nanopartículas/química , Paclitaxel/uso terapéutico , Resinas Acrílicas/química , Resinas Acrílicas/farmacocinética , Resinas Acrílicas/toxicidad , Animales , Antineoplásicos/química , Antineoplásicos/farmacocinética , Apoptosis/efectos de los fármacos , Trióxido de Arsénico/farmacocinética , Neoplasias de la Mama/patología , Proliferación Celular/efectos de los fármacos , Cetrimonio/química , Cetrimonio/toxicidad , Portadores de Fármacos/farmacocinética , Portadores de Fármacos/toxicidad , Liberación de Fármacos , Femenino , Puntos de Control de la Fase G2 del Ciclo Celular/efectos de los fármacos , Células Endoteliales de la Vena Umbilical Humana , Humanos , Células MCF-7 , Ratones Endogámicos ICR , Nanopartículas/toxicidad , Oligopéptidos/química , Oligopéptidos/farmacocinética , Oligopéptidos/toxicidad , Paclitaxel/química , Paclitaxel/farmacocinética , Porosidad , Dióxido de Silicio/química , Dióxido de Silicio/farmacocinética , Dióxido de Silicio/toxicidad , Ensayos Antitumor por Modelo de Xenoinjerto
9.
Appl Opt ; 60(11): 3006-3012, 2021 Apr 10.
Artículo en Inglés | MEDLINE | ID: mdl-33983194

RESUMEN

In this work, we propose adopting step-type quantum wells to improve the external quantum efficiency for GaN-based yellow micro light-emitting diodes. The step-type quantum well is separated into two parts with slightly different InN compositions. The proposed quantum well structure can partially reduce the polarization mismatch between quantum barriers and quantum wells, which increases the overlap for electron and hole wave functions without affecting the emission wavelength. Another advantage is that the slightly decreased InN composition in the quantum well helps to decrease the valence band barrier height for holes. For this reason, the hole injection capability is improved. More importantly, we also find that step-type quantum wells can make holes spread less to the mesa edges, thus suppressing the surface nonradiative recombination and decreasing the leakage current.

10.
Opt Express ; 28(6): 8668-8679, 2020 Mar 16.
Artículo en Inglés | MEDLINE | ID: mdl-32225487

RESUMEN

A better lateral current confinement is essentially important for GaN-based vertical-cavity-surface-emitting lasers (VCSELs) to achieve lasing condition. Therefore, a buried insulator aperture is adopted. However, according to our results, we find that the current cannot be effectively laterally confined if the insulator layer is not properly selected, and this is because of the unique feature for GaN-based VCSELs grown on insulating substrates with both p-electrode and n-electrode on the same side. Our results indicate that the origin for the current confinement arises from lateral energy band bending in the p-GaN layer rather than the electrical resistivity for the buried insulator. The lateral energy band in the p-GaN layer can be more flattened by using a buried insulator with a properly larger dielectric constant. Thus, less bias can be consumed by the buried insulator, enabling better lateral current confinement. On the other hand, the bias consumption by the buried insulator is also affected by the insulator thickness, and we propose to properly decrease the insulator layer thickness for reducing the bias consumption therein and achieving better lateral current confinement. The improved lateral current confinement will correspondingly enhance the lasing power. Thanks to the enhanced lateral current confinement, the 3dB frequency will also be increased if proper buried insulators are adopted.

11.
Opt Express ; 28(12): 18035-18048, 2020 Jun 08.
Artículo en Inglés | MEDLINE | ID: mdl-32680005

RESUMEN

In this report, we propose GaN-based vertical cavity surface emitting lasers with a p-GaN/n-GaN/p-GaN (PNP-GaN) structured current spreading layer. The PNP-GaN current spreading layer can generate the energy band barrier in the valence band because of the modulated doping type, which is able to favor the current spreading into the aperture. By using the PNP-GaN current spreading layer, the thickness for the optically absorptive ITO current spreading layer can be reduced to decrease internal loss and then enhance the lasing power. Furthermore, we investigate the impact of the doping concentration, the thickness and the position for the inserted n-GaN layer on the lateral hole confinement capability, the lasing power, and the optimization strategy. Our investigations also report that the optimized PNP-GaN structure will suppress the thermal droop of the lasing power for our proposed VCSELs.

12.
Zhongguo Zhong Yao Za Zhi ; 43(8): 1618-1625, 2018 Apr.
Artículo en Zh | MEDLINE | ID: mdl-29751708

RESUMEN

Arsenic trioxide (ATO) is an effective component of traditional Chinese medicine arsenic. The existing studies have shown its good inhibition and apoptosis ability on a variety of tumours. However, its toxicity and difficulties in the permeability into the blood brain barrier (BBB) has the limitation in the application of glioma treatment. Polyamide-amine dendrimer (PAMAM) is a synthetic polymer with many advantages, such as a good permeability, stability and biocompatibility. Additionally, the 5th generation of PAMAM is an ideal drug carrier due to its three-dimensional structure. In this study, the 5th generation of PAMAM co-modified with RGDyC and PEG, then confirmed by ¹H-NMR. The average particle size of nanoparticles was about 20 nm according to the nanoparticle size-potential analyser and transmission electron microscopy. in vitro release showed that the nanocarrier not only has the sustained release effect, but also some pH-sensitive properties. The cell results showed that PAMAM co-modified with RGDyC and PEGAM has a lower cytotoxicity than the non-modified group in vitro. Accordingly, the drug delivery system has a better anti-tumour effect across the blood brain barrier (BBB) in vitro, which further proves the tumour targeting of RGDyC.


Asunto(s)
Glioma , Trióxido de Arsénico , Línea Celular Tumoral , Dendrímeros , Portadores de Fármacos , Sistemas de Liberación de Medicamentos , Humanos , Polietilenglicoles
13.
Zhong Yao Cai ; 38(12): 2602-5, 2015 Dec.
Artículo en Zh | MEDLINE | ID: mdl-27352543

RESUMEN

OBJECTIVE: To optimize the formulation of Panax notoginseng saponins (PNS) transfersomes. METHODS: PNS transfersomes were prepared by film hydration-dispersion process. Based on the entrapment efficiency (EE) of ginsenoside Rg1 and ginsenoside Rb1, the effects of formulated quantity of sodium deoxycholate and cholesterol, the relative ion strength and pH value of hydration liquid were investigated. The formulation of PNS transfersomes were optimized by single-factor experiment and uniform design experiment. The in vitro characteristics of the optimized transfersomes were evaluated. RESULTS: The optimum formulation were as follows: egg phospholipid 0.45 g, cholesterol 0.05 g,vitamin E 0.01 g, sodium deoxycholate 0.119 g, PNS 0.1 g,10 mL of hydration liquid with pH at 4.75 (a mixture of 0.1 mol/L citric acid solution and 0.2 mol/L disodium orthophosphate solution, which corresponded to appropriate ion strength). The optimized PNS transfersomes had an average size of (121.8 ± 3.9) nm with a PDI of 0.136 ± 0.007 and a Zeta potential of (-8. 24 ± 0. 63) mV. The EE of ginsenoside Rg1 and ginsenoside Rb1 was 88.0% and 98.7% respectively. CONCLUSION: The formulation of PNS transfersomes can be optimized by uniform design experiment combined with single-factor experiment.


Asunto(s)
Química Farmacéutica/métodos , Medicamentos Herbarios Chinos/química , Panax notoginseng/química , Plantas Medicinales/química , Saponinas/química , Ginsenósidos/química
14.
Sci Total Environ ; 921: 170852, 2024 Apr 15.
Artículo en Inglés | MEDLINE | ID: mdl-38342462

RESUMEN

Under the twin pressures of global food security and dual­carbon strategies, improving farm eco-efficiency is critical for achieving China's goal of a 50 Pg increase in grain production, meeting the ambitious climate mitigation targets set by the Paris Agreement, and meeting seven of the seventeen Sustainable Development Goals (SDGs) set by the United Nations. However, there is limited research on eco-efficiency measures supported by localised fine-scale data and coupling mechanisms for the structure, production process, efficiency improvement, and carbon reduction synergies of integrated farming systems in China. This study used the Life Cycle Assessment (LCA) and Data Envelopment Analysis (DEA) methods to assess eco-efficiency at the farm level in northern China, included in the National Coupling Crop and Livestock Production Pilot Programs, to improve the eco-efficiency of farms to achieve increased production and emission reductions. The results showed that the overall eco-efficiency of farms was in the lower-middle range, with only 20.18 % of the farms having a technical efficiency exceeding 1. Problems included a backward level of pure technical efficiency and a return to scale. Non-integrated farms have the lowest profitability (41.33 %) and the highest carbon emission intensity of 3.03 kg CO2eq/USD. The global warming potential impact of non-integrated farms optimization could be reduced by 25 Pg CO2eq. Implementing the integrated farming mode has a significant advantage in reducing carbon emissions and improving productivity. Overall, farm fodder optimization can be increased by up to 42.41 %. Simultaneously, farms with sufficient farmland are more likely to realise a highly integrated business mode for crop cultivation and livestock breeding. Therefore, constructing a new type of green integrated farming system will help farms achieve increased production and emission reductions, promote the development of sustainable agriculture, and provide a Chinese model for the realisation of global SDGs.


Asunto(s)
Agricultura , Ganado , Animales , Agricultura/métodos , Granjas , China , Carbono , Estadios del Ciclo de Vida
15.
Bioresour Technol ; 410: 131305, 2024 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-39155021

RESUMEN

Composting is one of the primary methods for organic waste recycling in China. This study aims to analyze the product quality of organic fertilizer enterprises from the perspective of actual production and the relationship between production process variations and organic matter content in organic fertilizers based on 348 samples from 229 organic fertilizer companies across 22 provinces. Results showed that fertilizers produced through composting processes contain higher organic matter, averaging 45.42 %, compared to commercial organic fertilizers and bio-organic fertilizers. Raw materials, equipment, methods, operational scale, and personnel structure are key factors affecting the content of organic matter in products. Optimizing equipment and processes in Chinese organic fertilizer companies could increase organic matter content to 49.3 %, potentially reducing annual carbon emissions by an estimated 3.07 to 6.97 billion kg of CO2 equivalent, thereby supporting the realization of dual carbon goals.


Asunto(s)
Carbono , Compostaje , Fertilizantes , Carbono/análisis , China , Compostaje/métodos , Industrias , Reciclaje , Suelo/química
16.
Front Microbiol ; 15: 1372568, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38533333

RESUMEN

Aeration is an important factor to regulate composting efficiency and nitrogen loss. This study is aimed to compare the effects of different aeration modes (continuous and intermittent) and aeration rate on nitrogen conversion and bacterial community in composting from dehydrated sludge and corn straw. Results showed that the intermittent aeration mode at same aeration volume was superior to the continuous aeration mode in terms of NH3 emission reduction, nitrogen conversion and germination index (GI) improvement. Intermittent aeration mode with 1200 L/h (aeration 5 min, stop 15 min) [K5T15 (V1200)] and 300 L/h of continuous aeration helped to the conservation of nitrogen fractions and accelerate the composting process. However, it was most advantageous to use 150 L/h of continuous aeration to reduce NH3 emission and ensure the effective composting process. The aeration mode K5T15 (V1200) showed the fastest temperature rise, the longer duration of thermophilic stage and the highest GI (95%) in composting. The cumulative NH3 emission of intermittent aeration mode was higher than continuous aeration mode. The cumulative NH3 emission of V300 was 23.1% lower than that of K5T15 (V1200). The dominant phyla in dehydrated sludge and corn straw composting were Firmicutes, Proteobacteria, Actinobacteria, and Bacteroidetes. The dominant phylum in the thermophilic stage was Firmicutes (49.39%~63.13%), and the dominant genus was Thermobifida (18.62%~30.16%). The relative abundance of Firmicutes was greater in the intermittent aeration mode (63.13%) than that in the continuous aeration mode (57.62%), and Pseudomonas was dominant in composting with lower aeration rate and the lowest NH3 emission. This study suggested that adjustment to the aeration mode and rate could affect core bacteria to reduce the nitrogen loss and accelerate composting process.

17.
Biomater Sci ; 12(1): 187-198, 2023 Dec 19.
Artículo en Inglés | MEDLINE | ID: mdl-37981869

RESUMEN

Macrophage-hitchhiked arsenic/AB bionic preparations were developed to improve the therapeutic effect on liver cancer by means of the tumor-targeting ability of macrophages in vivo. In vitro and in vivo cellular uptake assays demonstrated that arsenic/AB, with negatively charged particles of around 100-200 nm size, could hitchhike to macrophages. Dissolution experiments of arsenic/AB showed that arsenic/AB could delay the release of arsenic and ensure the safety of macrophages during its transport. Histological examination confirmed the safety of the preparations for major organs. In vivo distribution experiment showed that the arsenic/AB bionic preparations could rapidly accumulate in tumors, and in vivo treatment experiment showed a significant tumor inhibition of arsenic/AB. The therapeutic mechanism of liver cancer might be that the arsenic/AB bionic preparations could inhibit tumor growth by reducing inflammatory response and inhibiting CSF1 secretion to block CSF1R activation to induce more differentiation of tumor-associated macrophages (TAMs) towards the anti-tumor M1 phenotype. Therefore, we concluded that the arsenic/AB bionic preparations could improve the distribution of arsenic in vivo by hitchhiking on macrophages as well as make it have tumor targeting and deep penetration abilities, thus increasing the therapeutic effect of arsenic on liver cancer with reduced side effects.


Asunto(s)
Arsénico , Neoplasias Hepáticas , Humanos , Arsénico/farmacología , Biónica , Neoplasias Hepáticas/tratamiento farmacológico , Macrófagos , Fenotipo , Microambiente Tumoral
18.
Zhonghua Fu Chan Ke Za Zhi ; 47(9): 676-80, 2012 Sep.
Artículo en Zh | MEDLINE | ID: mdl-23141291

RESUMEN

OBJECTIVE: To study ovarian development in vitrification of embryos born mice and expression of growth differentiation factor 9 (GDF-9) in its. METHODS: The vitrification recovery embryos (vitrified-embryo group) and fresh embryos (fresh-embryo group) were transplanted into pseudopregnant mice, respectively. The female offspring mice in two groups were sacrificed on the 3(rd), 7(th), 14(th), 21(st), 28(th) and 60(th) day after birth, the ovarian tissues were taken, 6 mice in each time point of each group. The ovarian development was observed by HE staining, the expression of GDF-9 mRNA and protein at each time point of two groups were detected by reverse transcription (RT)-PCR and western blot. RESULTS: HE staining showed that no abnormal ovarian development was observed in offsprings at two groups. On the 3(rd), 7(th), 14(th), 21(st), 28(th) and 60(th) day after birth, the expression of GDF-9 mRNA in vitrified-embryo group were 0.14 ± 0.07, 0.42 ± 0.16, 1.00 ± 0.24, 1.59 ± 0.28, 2.05 ± 0.32 and 2.23 ± 0.21, respectively, which in fresh-embryo group were 0.13 ± 0.06, 0.45 ± 0.18, 1.00 ± 0.21, 1.56 ± 0.26, 2.01 ± 0.37 and 2.26 ± 0.23, respectively, there was no statistical difference between two groups (P > 0.05); the expression of GDF-9 protein in vitrified-embryo group were 0.040 ± 0.030, 0.120 ± 0.060, 0.170 ± 0.030, 0.250 ± 0.040, 0.320 ± 0.060 and 0.330 ± 0.010, respectively, which in fresh-embryo group were 0.030 ± 0.020, 0.110 ± 0.040, 0.150 ± 0.010, 0.210 ± 0.020, 0.360 ± 0.070 and 0.350 ± 0.030, respectively, there was no statistical difference between two groups (P > 0.05). CONCLUSION: The ovarian morphology in vitrification of embryos born mice and expression of GDF-9 in ovary has no any obvious change.


Asunto(s)
Transferencia de Embrión , Factor 9 de Diferenciación de Crecimiento/metabolismo , Ovario/crecimiento & desarrollo , Ovario/metabolismo , Vitrificación , Animales , Criopreservación/métodos , Femenino , Factor 9 de Diferenciación de Crecimiento/genética , Ratones , ARN Mensajero/genética , ARN Mensajero/metabolismo , Factores de Tiempo
19.
Animals (Basel) ; 12(11)2022 Jun 03.
Artículo en Inglés | MEDLINE | ID: mdl-35681910

RESUMEN

Ecological pig-raising systems (EPRSs) differ from conventional breeding systems, focusing more on environmental consequences, human health, and food safety during production processes. Thus productions from EPRSs have undergone significant development in China. Thus far, adding plant fiber sources (e.g., sweet potato leaves, maize or wheat straw, potato, alfalfa, and vinasse) to feed has become a common practice to reduce the cost during the fattening period. Under such a context, it is necessary to choose the precision EPRS diet components and fattening period with low environmental consequences and high economic benefits. This study set up a database via pig growth models to predict environmental and economic performance based on two trials with 0%, 10%, 40%, 60%, and 80% maize silage (dry weight) added to the feed. A continuous curve about plant fiber concentration was built through the generated database. Our results showed that, with increased plant fiber concentration, the environmental performance of the EPRSs exhibited an "increase-decrease-increase" trend, and the economic performance firstly increased and then decreased. The best maize silage added percentages of emergy yield ratio (EYR), environmental loading ratio (ELR), unit emergy value (UEV), and emergy sustainability index (ESI), and the economic profits were 19.0%, 34.3%, 24.6%, 19.9%, and 18.0%, respectively. Besides, the 19.9% sun-dried maize silage added to the feed with a 360-day raising period had the best balance for environmental impact and economic performance. At the balance point, the performances of EYR, ELR, UEV, ESI, and the economic profit were only 0.04%, 3.0%, 0.8%, 0.0%, and 0.1%, respectively, lower than their maximum values. Therefore, we recommended the feed added 20% sun-dried maize silage is suitable for practical pig raising systems.

20.
Environ Sci Pollut Res Int ; 28(2): 1901-1918, 2021 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-32862345

RESUMEN

With a large agricultural sector, China is greatly affected by natural disasters caused by extreme weather events. Because the occurrence of natural disasters is closely related to the sharp increased consumption of energy and the massive emissions of carbon dioxide, this research examines relevant data from 2013 to 2017 in four major regions of China that cover 30 provincial administrative regions. Using the two-stage dynamic DEA model, we evaluate total efficiency value, two-stage efficiency value, and the efficiencies of energy consumption, CO2 emissions, and crop disaster areas, setting CO2 as the link between the production stage (first stage) and the crop damage stage (second stage). The research findings show that overall efficiency in China is generally low, whereby the total efficiencies of eastern and northeastern China are higher than those of central and western China. The efficiency value of the first stage (production stage) is greater than that of the second stage (crop damage stage), and the efficiency of most administrative regions' second stage is below 0.3, which is the main reason for the country's low overall efficiency. There is little difference between China's CO2 and energy consumption efficiency scores, but the efficiency values of crop disaster areas fluctuate greatly. The efficiency scores of various indicators in the eastern region are generally higher and more balanced, and the total efficiency scores exhibit a decreasing trend from east to west. Therefore, it is necessary to implement the environmental policy of controlling energy consumption and early warning of natural disasters in the central and western regions, and promote the R&D industry and technological innovation of carbon dioxide emission reduction and disaster control in the economically developed eastern regions.


Asunto(s)
Dióxido de Carbono , Desastres , Agricultura , Dióxido de Carbono/análisis , China , Desarrollo Económico
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