RESUMO
KDM6B-mediated epigenetic modification of the testicular regulator Dmrt1 has previously been identified as the primary switch of the male pathway in a temperature-dependent sex-determination (TSD) system; however, the molecular network of the female pathway has not yet been established. Here, we have functionally characterized for the first time an upstream regulator of the female pathway, the forkhead transcription factor FOXL2, in Trachemys scripta, a turtle species with a TSD system. FOXL2 exhibited temperature-dependent female-specific expression patterns before the onset of gonadal differentiation and was preferentially localized in ovarian somatic cells. Foxl2 responded rapidly to temperature shifts and estrogen. Importantly, forced expression of Foxl2 at the male-producing temperature led to male-to-female sex reversal, as evidenced by the formation of an ovary-like structure, and upregulation of the ovarian regulators Cyp19a1 and R-spondin1. Additionally, knockdown of Foxl2 caused masculinization at the female-producing temperature, which was confirmed by loss of the female phenotype, development of seminiferous tubules, and elevated expression of Dmrt1 and Sox9. Collectively, we demonstrate that Foxl2 expression is necessary and sufficient to drive ovarian determination in T. scripta, suggesting a crucial role of Foxl2 in female sex determination in the TSD system.
Assuntos
Tartarugas , Animais , Feminino , Regulação da Expressão Gênica no Desenvolvimento , Gônadas/metabolismo , Masculino , Processos de Determinação Sexual/genética , Diferenciação Sexual/genética , Temperatura , Tartarugas/genéticaRESUMO
The coordinated development of industrial agglomeration and economic resilience can drive regional economic advantages; this type of development has become a catalyst for sustainable growth and high-quality development of the economy in China. This study applied models, including the coupling coordination degree, spatial autocorrelation, and Tobit, to explore the heterogeneous characteristics of the coupling of China's industrial agglomeration and regional economic resilience from 2005 to 2019. Additionally, by applying the perspectives of economic and geographic location, indicators were selected to analyze the associated influencing factors, including industrial externalities, new economic geographies, economic policy factors, and other aspects. We found that the overall coupling between industrial agglomeration and economic resilience increased over the study period, but with only a moderate level of coordination. Provinces with high, moderate, and low levels of coordination eventually emerged along a strip-like alternating pattern in space. The dependence increased with an increase in space, but was not significant, and there was a lack of benign interaction between the regions. With respect to interactivity between locations, the interaction of the east and the coast was the most active. There were lower levels of interaction between the west and inland regions. This further confirmed the significant temporal and spatial heterogeneity of the coupling. Environmental pollution, market consumption, the quality of space, and technological support significantly promoted the coupling; opening to the outside world did not. Specifically, with respect to economic location, market consumption and spatial quality had a significant positive effect on the eastern coupling. The center and west regions were significantly affected by economic density and market consumption, and the northeast region was affected by spatial quality and capital intensity. Concerning geographical location, market and technological forces strongly promoted interactions in both the coast and inland regions. The study found that both the government and the market need better guidance to effectively engage with and shape industrial agglomeration and economic resilience in a scientific, reasonable, localized, and distinctive manner.
RESUMO
Since the late 1970s, the Yellow River Basin (YRB) has experienced accelerated land-use/land cover changes (LULCC) and consumptive water use (CWU) that have imposed low-flow regimes. Upon the continuation of these anthropogenic activities in the future, significant hydrological alteration is expected. This study takes a hydrological perspective on drought to project changes in the YRB drought risk under future LULCC and CWU business-as-usual (BAU) scenarios. A combination of seasonal trend forecasting, drought indices, land-use and hydrological modeling techniques was used. Future LULCC is assessed based on two BAU scenarios to explore the patterns of LULCC with (LULCC-BAU1) and without (LULCC-BAU2) the continuation of the Chinese Grain for Green Program. The results indicated that LULCC-BAU2 will increase the risk of mild and moderate droughts, while CWU and LULCC-BAU1 will impose higher risk of severe and extreme events. LULCC-BAU1 is projected to exacerbate the duration and intensity of the agricultural/hydrological droughts. The frequency of hydrological drought under LULCC-BAU1 and CWU scenarios is projected to increase by 43% and 53% during 2021-2050. The future agricultural droughts will likely be more intense and prolonged than meteorological droughts. Hydrological droughts, however, will be characterized by prolonged but less intense drought comparing to the metrological droughts. The meteorological to agricultural drought propagation will likely be driven by LULCC under BAU1, while the meteorological to hydrological drought propagation is controlled by CWU changes.
Assuntos
Secas , Rios , Previsões , Hidrologia , MeteorologiaRESUMO
High-tap-density silicon nanomaterials are highly desirable as anodes for lithium ion batteries, due to their small surface area and minimum first-cycle loss. However, this material poses formidable challenges to polymeric binder design. Binders adhere on to the small surface area to sustain the drastic volume changes during cycling; also the low porosities and small pore size resulting from this material are detrimental to lithium ion transport. This study introduces a new binder, poly(1-pyrenemethyl methacrylate-co-methacrylic acid) (PPyMAA), for a high-tap-density nanosilicon electrode cycled in a stable manner with a first cycle efficiency of 82%-a value that is further improved to 87% when combined with graphite material. Incorporating the MAA acid functionalities does not change the lowest unoccupied molecular orbital (LUMO) features or lower the adhesion performance of the PPy homopolymer. Our single-molecule force microscopy measurement of PPyMAA reveals similar adhesion strength between polymer binder and anode surface when compared with conventional polymer such as homopolyacrylic acid (PAA), while being electronically conductive. The combined conductivity and adhesion afforded by the MAA and pyrene copolymer results in good cycling performance for the high-tap-density Si electrode.
Assuntos
Fontes de Energia Elétrica , Eletrodos , Lítio/química , Nanoestruturas , Polímeros/química , Silício/química , Microscopia de Força AtômicaRESUMO
Silicon alloys have the highest specific capacity when used as anode material for lithium-ion batteries; however, the drastic volume change inherent in their use causes formidable challenges toward achieving stable cycling performance. Large quantities of binders and conductive additives are typically necessary to maintain good cell performance. In this report, only 2% (by weight) functional conductive polymer binder without any conductive additives was successfully used with a micron-size silicon monoxide (SiO) anode material, demonstrating stable and high gravimetric capacity (>1000 mAh/g) for â¼500 cycles and more than 90% capacity retention. Prelithiation of this anode using stabilized lithium metal powder (SLMP) improves the first cycle Coulombic efficiency of a SiO/NMC full cell from â¼48% to â¼90%. The combination enables good capacity retention of more than 80% after 100 cycles at C/3 in a lithium-ion full cell.
RESUMO
The implementation of green credits has become an important engine for China's high-quality energy development (HQED). On the basis of constructing an index of HQED and the panel data of thirty provinces in China from 2008 to 2019, this study empirically investigated the effects of green credits on HQED and the action mechanisms behind it in a multi-dimensional manner using a panel fixed-effects model, mediating-effects model, and spatial Durbin model. The results indicated that green credits had significantly contributed to China's HQED, and that conclusion still held true after a series of robustness tests were conducted. It was found that industrial structures and human capital were important channels through which green credits influenced China's HQED. Moreover, the spatial spillover effects of green credits on HQED were also confirmed. Finally, in terms of temporal heterogeneity, the positive effects of green credits on HQED were found to have increased significantly after 2012. Also, in terms of regional heterogeneity, this study observed that the positive influence of green credits on HQED was more significantly in central and western China than in eastern China, and in southern China than in northern China. The results obtained in this research investigation will potentially provide some important insights for energy planners and policymakers to further the understanding of the drivers of HQED, and the corresponding transmission mechanisms and regional differences.
Assuntos
Desenvolvimento Econômico , Indústrias , Humanos , ChinaRESUMO
Aqueous zinc-ion batteries (AZIBs) offer promising prospects for large-scale energy storage due to their inherent abundance and safety features. However, the growth of zinc dendrites remains a primary obstacle to the practical industrialization of AZIBs, especially under harsh conditions of high current densities and elevated temperatures. To address this issue, a Janus separator with an exceptionally ultrathin thickness of 29 µm is developed. This Janus separator features the bacterial cellulose (BC) layer on one side and Ag nanowires/bacterial cellulose (AgNWs/BC) layer on the other side. High zincophilic property and excellent electric/thermal conductivity of AgNWs make them ideal for serving as an ion pump to accelerate Zn2+ transport in the electrolyte, resulting in greatly improved Zn2+ conductivity, deposition of homogeneous Zn nuclei, and dendrite-free Zn. Consequently, the Zn||Zn symmetrical cells with the Janus separator exhibit a stable cycle life of over 1000 h under 80 mA cm-2 and are sustained for over 600 h at 10 mA cm-2 under 50 °C. Further, the Janus separator enables excellent cycling stability in AZIBs, aqueous zinc-ion capacitors (AZICs), and scaled-up flexible soft-packaged batteries. This study demonstrates the potential of functional separators in promoting the application of aqueous zinc batteries, particularly under harsh conditions.
RESUMO
The synergy of the digital economy and green total factor productivity (TFP) is the foundation for achieving beneficial outcomes for both the economy and environment. This synergy is also the catalyst for high-quality development and sustainable economic growth in China. The study applied a modified Ellison-Glaeser (EG) index, super-efficiency slacks-based measure (SBM) with a Malmquist-Luenberger (ML) index, coupling coordination degree, and other models to explore the spatiotemporal heterogeneity of the coupling between the digital economy and green TFP from 2011 to 2020 and also analyzed the influencing factors of the coupling. The results show that the coupling between the digital economy and green TFP showed an overall upward trend from imbalance to synergy during the study period. The distribution of the synergistic coupling expanded from point-like to band-like, and there was a significant spreading pattern from the east to the center or west China. The number of cities in a transition state decreased significantly. Spatial jumps, a coupling linkage effect, and evolution in time were prominent. Additionally, the absolute difference among cities expanded. Although coupling in the west experienced the fastest growth rate, the coupling in the east and resource-based cities showed significant benefits. Coupling did not reach an ideal coordinated state, and a neutral interaction pattern remains to be formed. Industrial collaboration, industrial upgrading, government support, economic foundation, and spatial quality all positively impacted the coupling; technological innovation had a lagged effect; and environmental regulation has not reached its full potential. Further, the positive effects of government support and spatial quality performed better in the east and in non-resource-based cities. Due to the optimization of industrial structure, the coupling of the west and resource-based cities achieved better dividends; however, spatial quality needs further improvement. Therefore, the efficient coordination of China's digital economy and green TFP requires a scientific, reasonable, localized, and distinctive approach.
Assuntos
Desenvolvimento Econômico , Governo , China , Cidades , IndústriasRESUMO
The 14th Five-Year Plan period is a critical period for China to achieve high-quality development. Based on super-efficiency slacks-based measure (SBM) model, grey-related analysis (GRA) and other models, this paper studies the heterogeneity of the coupling relationship among technological innovation, industrial transformation and environmental efficiency in the Huaihai Economic Zone during the period of 2005-2019. In addition, it analyzes the coupling mechanism of single and binary systems to the ternary system, which is of great significance for the collaborative symbiosis among systems. The findings are as follows. 1) The technological innovation, industrial transformation and environmental efficiency (TIE) systems of the Huaihai Economic Zone had significant spatial-temporal heterogeneity. Although their evaluation value fluctuated, the development trends are all positive. Ultimately, technological innovation is characterized by being high in the northeast and low in the southwest around Xuzhou, while other systems are relatively staggered in space. 2) The coupling of TIE systems is in transition, lack of orderly integration and benign interaction. However, the developing trend of interaction is also upward, and a spatial pattern driven by Xuzhou and Linyi as the dual cores has gradually formed. Moreover, the coupling is mostly manifested as outdated technological innovation and industrial transformation. Except for the final coordination of regenerative cities, the other resource types are all in transition. Cities in all traffic locations are still in transition. The overall system interaction of cities on Longhai Line (Lanzhou-Lianyungang Railway) is relatively optimal, and cities on Xinshi Line (Xinxiang-Rizhao Railway) are accelerating toward synergy. 3) The coupling status of TIE systems depends on the development of the single system and the interaction of the binary (2E) system. The coupling is closely related to technological innovation and Technology-Industry system, and is hindered by the inefficient interaction of Technology-Environment system. Specifically, the synergy of regenerative cities is attributed to the advantage of a single system and the effective integration of 2E systems. Beneficial from the advantages of environmental efficiency, the cities on Xinshi Line promote the synergy of the 2E and TIE systems. Therefore, while the Huaihai Economic Zone stimulates the development potential of the single and 2E systems, it is necessary to amplify the superimposition effect of systems in accordance on the basis of resource and location.
RESUMO
Metastasis has been widely recognized as the most lethal threats for cancer patients. Due to their special genetic and environmental context, cancer stem cells (CSCs) which are resistant to most cytotoxic drugs and radiation, are considered as the dominant culprit for metastasis. Thus, the efficient targeting and thorough elimination of CSCs are significantly urgent for the enhancement of therapeutic efficacy. Herein, we developed a facile and smart photothermal-chemo therapeutic nano-assembly system, of which the surface was modified by a sheddable PEG shell and acid-activatable pro-penetration peptide, to surmount the physiological barriers in targeting CSCs. A highly-efficient diradical-featured croconium-based photothermal agent and a natural cytotoxic heat shock protein (HSP) inhibitor were co-loaded in redox-sensitive chitosan matrices to realize the synergistic photothermal-chemo therapy. Within solid tumors, the PEG shell that prevents the nano-assembly from mononuclear phagocytic clearance could rapidly leave to expose the positively charged chitosan, and the detached iRGD could further actuate the tumor penetration of chitosan nanoparticles, and allow the CSCs targeting by selective recognition of CD44 protein. Owing to the HSP inhibition and chemo-sensitization, both the CSCs and non-CSCs could be thoroughly eliminated by the designed nano-assembly, largely inhibiting the tumor growth and metastasis. This work provides a potential strategy for CSCs-targeting drug delivery to solve the CSCs-related metastasis.
Assuntos
Hipertermia Induzida , Nanopartículas , Neoplasias , Linhagem Celular Tumoral , Doxorrubicina/farmacologia , Humanos , Nanopartículas/uso terapêutico , Células-Tronco Neoplásicas , FototerapiaRESUMO
The limited anticancer drug library and the frequent occurrence of drug resistance have driven monotherapy-based cancer therapy into a difficult situation. Considering the formidable process of new drug discovery, combination therapy using currently available drugs is a potential alternative. Nevertheless, the barrier between in vitro combination screening and precise in vivo delivery remains insurmountable in the current free-drug- or nanoparticle (NP)-based combination therapy, which substantially hinders the application of combination therapy. Herein, a novel, precise drug delivery strategy to realize efficient and individualized combination therapy is proposed. Nanomedicine (NM) is engineered using a microfluidics-based mixer by combining rationally designed polymeric prodrugs of three commercial chemotherapeutics and a cascade-responsive block copolymer; the NM possesses ratiometric drug loading and synchronized drug release. In addition to quantitative drug loading and precisely controlled drug combination, consistent nanoproperties of these NPs make their in vivo fate predictable. Consequently, tumor growth and metastasis can be effectively inhibited by precisely prescribed NPs derived from in vitro combination screening. This proof-of-concept study clearly reveals the feasibility of overcoming the current drug-library limitations through precise delivery of any predetermined drug combination, facilitating translational research of individualized combination therapy.
Assuntos
Antineoplásicos , Neoplasias , Pró-Fármacos , Antineoplásicos/farmacologia , Antineoplásicos/uso terapêutico , Sistemas de Liberação de Medicamentos , Humanos , Nanomedicina , Neoplasias/tratamento farmacológico , Pró-Fármacos/uso terapêuticoRESUMO
Drought in human-dominated environments cannot be seen as a unidirectional hazard as its characteristics are derived and modified by both natural climate variability and human influences. In this study, we applied an observation-modeling framework to quantify the natural and human controls on drought characteristics based on simulated and observed hydrometeorological data from six sub-catchments of the Yellow River Basin in China. A calibrated Soil and Water Assessment Tool (SWAT) was applied to simulate the naturalized situation, whereas Standardized Precipitation Index, Streamflow Drought Index, and Soil Moisture Deficit Index were used to characterize drought at meteorological, agricultural and hydrological aspects. Furthermore, various statistical tools, i.e., bivariate correlation analysis, heat maps, and linear models based on multiple regression, were applied to find the statistical relationships between drought characteristics and the multiple influencing factors. The results revealed that the duration of precipitation's dry spells was important for agricultural drought duration, whereas hydrological drought severity and duration highly depended on soil moisture. Meteorological to agricultural drought propagation mechanism was primarily affected by land use/land cover change (LULCC), whereas meteorological to hydrological propagation was influenced mostly by direct human activities (DHA). The human modifiers were found to have both positive and negative effects on drought severity and duration. For instance, agricultural practices and afforestation intensified soil moisture drought, while grassland restoration had a positive impact on agricultural drought severity. Deforestation enhanced hydrological drought, while afforestation and grassland restoration had the opposite effect. Hydrological drought severity and duration were largely amplified by DHA but enhanced by irrigation return flow. Spatially, sub-catchments with high urbanization and irrigated cropland were found to have shorter and less severe droughts than those dominated by grassland.
RESUMO
Due to the increasing quantities of phenolic compounds present in wastewater, the use of enzymatic degradation with the laccase has attracted much attention as a green option for their removal. In this work, we developed a novel immobilization technology using 3D bioprinting for laccase immobilization. The hydrogel mechanism properties were optimized by experimenting with different component ratios of sodium alginate (SA), acrylamide (AM), and hydroxyapatite (HA). The improved mechanism properties were validated by morphology pictures and rheology characteristics. The optimal AM:HA:SA ratio was determined to be 4:1.2:1. We then employed an extrusion-based bioprinting technique to prepare the immobilized laccase. The substrate conversion was increased with the addition of HA, which improved the permeability of the matrix, and proved to be suitable for immobilization. The resulting immobilized laccase was used for the biodegradation of p-chlorophenol. The effects of the initial substrate concentration, pH, and temperature were evaluated. The immobilized laccase exhibited good storage stability and reusability, retaining over 80% of its initial activity after 72 h of storage, and was able to be reused for seven batches. These results highlight that the immobilized laccase prepared by 3D bioprinting has great potential for use in the biodegradation of phenolic compounds.
Assuntos
Clorofenóis/química , Enzimas Imobilizadas/química , Lacase/química , Águas Residuárias/química , Acrilamida/química , Alginatos/química , Biodegradação Ambiental , Bioimpressão , Durapatita/química , Hidrogéis , Concentração de Íons de Hidrogênio , Impressão Tridimensional , TemperaturaRESUMO
This study examines the effects of manganese oxide octahedral molecular sieve chitosan microspheres (Fe3O4@OMS-2@CTS) on anaerobic and aerobic microbial communities during sewage biological treatment. The addition of Fe3O4@OMS-2@CTS (0.25 g/L) resulted in enhanced levels of operational performance for decolourization dye X-3B. However, degradation dye X-3B inhibition in the presence of Fe3O4@OMS-2@CTS was recorded as greater than or equal to 1.00 g/L. Illumina MiSeq high throughput sequencing of the 16 S rRNA gene showed that 108 genera were observed during the anaerobic process, while only 71 genera were observed during the aerobic process. The largest genera (Aequorivita) decreased from 21.14% to 12.65% and the Pseudomonas genera increased from 10.57% to 12.96% according to the abundance in the presence of 0.25 g/L Fe3O4@OMS-2@CTS during the anaerobic process. The largest Gemmatimonas genera decreased from 21.46% to 11.68% and the Isosphaerae genera increased from 5.8% to 11.98% according to the abundance in the presence of 0.25 g/L Fe3O4@OMS-2@CTS during the aerobic process. Moreover, the X-ray photoelectron spectroscopy results show that the valence states of Mn and Fe in Fe3O4@OMS-2@CTS changed during sewage biological treatment.
Assuntos
Bactérias/metabolismo , Quitosana/química , Recuperação e Remediação Ambiental/métodos , Compostos de Manganês/química , Microesferas , Óxidos/química , Esgotos/microbiologia , Anaerobiose , Compostos Azo/metabolismo , Bactérias/classificação , Biodegradação Ambiental , Análise da Demanda Biológica de Oxigênio , Reatores Biológicos/microbiologia , Cor , Compostos Férricos/química , Temperatura Alta , Naftalenossulfonatos/metabolismo , Peróxidos/química , Filogenia , Análise de Sequência de DNARESUMO
High capacity and high density functional conductive polymer binder/SiO electrodes are fabricated and calendered to various porosities. The effect of calendering is investigated in the reduction of thickness and porosity, as well as the increase of density. SiO particle size remains unchanged after calendering. When compressed to an appropriate density, an improved cycling performance and increased energy density are shown compared to the uncalendered electrode and overcalendered electrode. The calendered electrode has a high-density of â¼1.2 g/cm(3). A high loading electrode with an areal capacity of â¼3.5 mAh/cm(2) at a C/10 rate is achieved using functional conductive polymer binder and simple and effective calendering method.
RESUMO
Thin films of copper are widely used as current collectors for the negative electrodes in lithium-ion batteries. However, a major cause of battery failure is delamination between the current collector and the graphite anode. When silicon or tin is used as active material, delamination becomes a key issue owing to the large volume changes of these materials during lithation and delithation processes. Learning from Nature, we developed a new biomimetic approach based on the adhesion properties of the feet of geckos. The biomimetic approach improves adhesion between the laminate and the copper surface by introducing an array of Cu(OH)2 nanorods, which increases the surface area of the current collector. When graphite anode laminate is casted onto regular and a modified copper surfaces, the modified current collector displays superior adhesion to graphite and the PVDF binder-based electrode. The electrochemical performance of the batteries using these electrodes is not compromised by the additional chemistry of the Cu(OH)2 on the copper surface. The technique can lead to enhanced battery lifetimes over long-term cycling.