Effects of drought and climate factors on vegetation dynamics in Central Asia from 1982 to 2020.

Ecological security and ecosystem stability in Central Asia depend heavily on the local vegetation. Vegetation dynamics and the response and hysteresis relationships to climate factors and drought on multiple scales over long time series in the region still need to be further explored. Using the net primary productivity (NPP) values as the vegetation change index of interest, in this study, we analyzed vegetation dynamics in Central Asia from 1982 to 2020 and assessed the responses and time lags of vegetation to climate factors and drought. The results showed that NPP gradually decreased from north to south and from east to west. Vegetation was distributed along both sides of the mountains. The temperatures rose from northeast to southwest, while precipitation gradually increased from southwest to northeast. The proportion of dry and wet years was as follows: normal (56.41%) > slightly dry (28.2%) > slightly humid (15.39%). Precipitation and drought conditions were positively correlated with NPP during the growing season, while temperature was negatively correlated with NPP. Increased spring temperature, precipitation, and drought conditions positively affected vegetation, while sustained summer temperature resulted in suppressed vegetation growth. Autumn vegetation was positively affected by temperature and drought, and precipitation was negatively correlated with autumn vegetation. Increasing winter temperatures promoted vegetation growth. The time lag between NPP and temperature gradually increased from northeast to southwest, and the time lag between NPP and precipitation gradually increased from south to north. Spring temperatures had the greatest beneficial impact on forestlands; summer climatic factors and drought had little effect on shrublands; the autumn climate exhibited small differences in its influence of each plant type; and winter temperatures had the greatest positive effect on grasslands. No time lag effect was found between any of the four vegetation types and precipitation. A one-month lag was found between cultivated lands and temperature; a two-month lag was found between forestlands and temperature; and a one-month lag was found between forestlands and drought and between shrublands and drought. The results can provide a scientific foundation for the sustainable development and management of ecosystems.

Cystic clear cell papillary renal cell carcinoma: is it related to multilocular clear cell cystic neoplasm of low malignant potential?

AIMS: We report the morphological spectrum of nine cystic clear cell papillary renal cell carcinomas (CCP-RCC). METHODS AND RESULTS: Mean tumour size was 2.1 cm and the stage was pT1a in all cases. The original diagnosis was multilocular clear cell cystic renal neoplasm of low malignant potential (MCCN-LMP) in five and CCP-RCC in four patients. All examples were composed of variably sized cysts lined by one layer of clear cells. Two tumours were exclusively cystic, seven showed tubular formation in the septae and five in which the tubular growth was compact and pseudo-solid. Two tumours had foci of nests and single cells showing similarities to the cellular areas of MCCN-LMP. The tubular/pseudo-solid/nested/single-cells foci formed microscopic nodules with a mean size of 1.8 mm. Three tumours had intracystic micropapillary formation. Cells were of International Society of Urological Pathology (ISUP) grades 1-2/4. In all cases, the neoplastic nuclei were aligned away from the basement membranes at least focally. Tumours were positive for paired box gene 8 (PAX8), carbonic anhydrase IX (CAIX), cytokeratin (CK)7 and CK34BE12 and negative for CD10. CONCLUSIONS: Cystic CCP-RCC is a pattern that should be recognized, as it shows overlapping morphological features with both multilocular cyst and MCCN-LMP. This series raises the question of whether some reported MCCN-LMPs are actually cystic CCP-RCC.

Protein kinase A modulates transforming growth factor-ß signaling through a direct interaction with Smad4 protein.

Transforming growth factor ß (TGFß) signaling normally functions to regulate embryonic development and cellular homeostasis. It is increasingly recognized that TGFß signaling is regulated by cross-talk with other signaling pathways. We previously reported that TGFß activates protein kinase A (PKA) independent of cAMP through an interaction of an activated Smad3-Smad4 complex and the regulatory subunit of the PKA holoenzyme (PKA-R). Here we define the interaction domains of Smad4 and PKA-R and the functional consequences of this interaction. Using a series of Smad4 and PKA-R truncation mutants, we identified amino acids 290-300 of the Smad4 linker region as critical for the specific interaction of Smad4 and PKA-R. Co-immunoprecipitation assays showed that the B cAMP binding domain of PKA-R was sufficient for interaction with Smad4. Targeting of B domain regions conserved among all PKA-R isoforms and exposed on the molecular surface demonstrated that amino acids 281-285 and 320-329 were required for complex formation with Smad4. Interactions of these specific regions of Smad4 and PKA-R were necessary for TGFß-mediated increases in PKA activity, CREB (cAMP-response element-binding protein) phosphorylation, induction of p21, and growth inhibition. Moreover, this Smad4-PKA interaction was required for TGFß-induced epithelial mesenchymal transition, invasion of pancreatic tumor cells, and regulation of tumor growth in vivo.

Boron dopant- and nitrogen defect-decorated C3N5 porous nanostructure as an efficient sulfur host for lithium-sulfur batteries.

Active site implantation and morphology manipulation are efficient protocols for boosting the electrochemical performance of carbon nitrides. As a promising sulfur host for lithium-sulfur batteries (LSBs), in this study, C3N5 porous nanostructure incorporated with both boron (B) atoms and nitrogen (N) defects was constructed (denoted as ND-B-C3N5) using a two-step strategy, i.e., pyrolysis of the mixture of 3-amino-1,2, 4-triazole and boric acid to obtain B-doped C3N5 porous nanostructure and then KOH etching under hydrothermal condition to generate N defects. The doped B atoms in the C3N5 porous nanostructure are in the form of B-N bonds and grafted B-O bonds. N defects are primarily created at the CN-C positions of the triazine unit, leaving behind some N vacancies and cyano groups. Benefiting from the involvement of B dopants and N defects, the optimized ND-B-C3N5-12 sample exhibits ameliorative conductivity, mass transport, lithium polysulfides (LiPSs) adsorption ability, diffusion of Li+ ions, Li2S deposition capacity, sulfur redox polarization, and a reversible solid-solid sulfur redox process. Consequently, the ND-B-C3N5-12/S cathode delivers accelerated redox performance of polysulfides for LSBs, revealing capacities of 1091 ± 44 and 753 ± 20 mAh/g at 0.2C for the initial and 300th cycles, respectively. The ND-B-C3N5-12/S cathode is also endowed with desired sulfur redox activity and stability at 2C for 1000 cycles, holding an initial discharging capacity of 788 ± 24 mAh/g and a low decay rate of 0.05 % per cycle.

Monitoring and influencing factors of grassland livestock overload in Xinjiang from 1982 to 2020.

It is crucial to estimate the theoretical carrying capacity of grasslands in Xinjiang to attain a harmonious balance between grassland and livestock, thereby fostering sustainable development in the livestock industry. However, there has been a lack of quantitative assessments that consider long-term, multi-scale grass-livestock balance and its impacts in the region. This study utilized remote sensing and empirical models to assess the theoretical livestock carrying capacity of grasslands. The multi-scale spatiotemporal variations of the theoretical carrying capacity in Xinjiang from 1982 to 2020 were analyzed using the Sen and Mann-Kendall tests, as well as the Hurst index. The study also examined the county-level grass-livestock balance and inter-annual trends. Additionally, the study employed the geographic detector method to explore the influencing factors. The results showed that: (1) The overall theoretical livestock carrying capacity showed an upward trend from 1982 to 2020; The spatial distribution gradually decreased from north to south and from east to west. In seasonal scale from large to small is: growing season > summer > spring > autumn > winter; at the monthly scale, the strongest livestock carrying capacity is in July. The different grassland types from largest to smallest are: meadow > alpine subalpine meadow > plain steppe > desert steppe > alpine subalpine steppe. In the future, the theoretical livestock carrying capacity of grassland will decrease. (2) From 1988 to 2020, the average grass-livestock balance index in Xinjiang was 2.61%, showing an overall increase. At the county level, the number of overloaded counties showed an overall increasing trend, rising from 46 in 1988 to 58 in 2020. (3) Both single and interaction factors of geographic detectors showed that annual precipitation, altitude and soil organic matter were the main drivers of spatiotemporal dynamics of grassland load in Xinjiang. The results of this study can provide scientific guidance and decision-making basis for achieving coordinated and sustainable development of grassland resources and animal husbandry in the region.

Construction of N-doped carbon encapsulated Mn2O3/MnO heterojunction for enhanced lithium storage performance.

Owing to high theoretical capacity, low cost and abundant availability, manganese oxides are widely viewed as promising anodes for lithium-ion batteries (LIBs). Nonetheless, their practical application is significantly hindered by poor electrical conductivity, sluggish reaction kinetics and substantial volume change. In this work, an ingenious polypyrrole encapsulation followed by pyrolysis strategy is proposed to produce N-doped carbon encapsulated Mn2O3/MnO heterojunction (Mn2O3/MnO@NC) by using mechanically ground Mn3O4/C3N4 mixture as the precursor. The results show that the selection of precursor plays a pivotal role in the successful preparation of Mn2O3/MnO@NC hybrid. It is revealed that the uniform encapsulation by N-doped carbon significantly enhances the conductivity and structural stability of the final product. Concurrently, the Mn2O3/MnO heterojunction within the resultant hybrid exhibits a unique quantum-dot size, which effectively shortens ion transport pathways and exposes the active sites for lithium storage. Additionally, experimental observations and theoretical calculations demonstrate that the built-in electric fields generated at the interfaces of Mn2O3/MnO heterojunction accelerate the charge transfer and ion diffusion, thereby enhancing the electrochemical reaction kinetics. As a result, the Mn2O3/MnO@NC hybrid displays much enhanced lithium storage performance. Evidently, our work offers a good guidance for the design and synthesis of advanced transition metal oxide/carbon anodes for LIBs.

Bioelectrochemical cascade reaction for energy-saving hydrogen production and innovative Zn-air batteries.

The oxygen evolution reaction (OER) is an important half-reaction in electrochemical hydrogen production (EHP) and rechargeable metal-air batteries. However, the sluggish OER kinetics has seriously impeded their performance. Herein, we report a bioelectrochemical cascade system composed of glucose oxidase (GOx)-functionalized N-doped porous carbon nanofibers to replace OER in EHP and rechargeable Zn-air batteries (ZABs) applications. In this cascade system, GOx catalyzes oxidation of glucose to produce value-added gluconic acid accompanied with the generation of H2O2 under aerobic conditions. The subsequent electrocatalytic oxidation of H2O2 replacing the OER results in an onset voltage below 1.10 V for EHP, and a low charging voltage of 1.35 V as well as a small charging/discharging voltage gap of âˆ¼ 280 mV over 170 h for ZABs in neutral aqueous electrolytes. The advantages of employing the innovative bioelectrochemical cascade reaction are demonstrated in EHP and ZABs, achieving the full utilization of biomass energy in energy-saving electrochemical systems for energy storage and conversion.

3D hierarchical self-supporting Bi2Se3-based anode for high-performance lithium/sodium-ion batteries.

Bi2Se3 is a promising material for anodes in lithium-ion batteries (LIBs) and sodium-ion batteries (SIBs) due to its abundance, easy preparation, and high capacity. However, its practical application is hindered by low conductivity and significant volume variation during cycling, leading to poor rate capability and cycling stability. Herein, a novel composite consisting of Bi2Se3 nanoplates deposited on carbon cloth (CC) and encapsulated by reduced graphene oxide (rGO) has been designed and synthesized. The composite structure combines the advantages of the Bi2Se3 nanoplates, CC substrate, and rGO encapsulation, leading to enhanced electrochemical properties. The physical vapor deposition of Bi2Se3 nanoplates onto CC ensures a high loading of active material, while the rGO encapsulation provides a conductive and stable framework for the composite. This synergistic design allows for improved electron and ion transport, as well as efficient accommodation of the volume changes during cycling. In LIBs, the composite demonstrates a high reversible capacity of 467.5 mAh/g at 0.1 A/g after 120 cycles. Moreover, it displays an outstanding rate capability, delivering a capacity of 398.6 mAh/g at 5.0 A/g. Similarly, in SIBs, the composite maintains a reversible capacity of 375.3 mAh/g at 0.1 A/g over 100 cycles and exhibits a high-rate capacity of 286.3 mAh/g at 5.0 A/g. This work represents a significant step forward in addressing the challenges associated with Bi2Se3 as an anode material, paving the way for the development of high-performance LIBs and SIBs.

Defect-Enriched Graphene Nanoribbons Tune the Adsorption Behavior of the Mediator to Boost the Lactate/Oxygen Biofuel Cell.

Owing to the high efficiency and specificity in moderate conditions, enzymatic biofuel cells (EBFCs) have gained significant interest as a promising energy source for wearable devices. However, the instability of the bioelectrode and the lack of efficient electrical communication between the enzymes and electrodes are the main obstacles. Herein, defect-enriched 3D graphene nanoribbons (GNRs) frameworks are fabricated by unzipping multiwall carbon nanotubes, followed by thermal annealing. It is found that defective carbon shows stronger adsorption energy towards the polar mediators than the pristine carbon, which is beneficial to improving the stability of the bioelectrodes. Consequently, the EBFCs equipped with the GNRs exhibit a significantly enhanced bioelectrocatalytic performance and operational stability, delivering an open-circuit voltage and power density of 0.62 V, 70.7 µW/cm2, and 0.58 V, 18.6 µW/cm2 in phosphate buffer solution and artificial tear, respectively, which represent the high levels among the reported literature. This work provides a design principle according to which defective carbon materials could be more suitable for the immobilization of biocatalytic components in the application of EBFCs.

Carbon nanorods assembled coral-like hierarchical meso-macroporous carbon as sustainable materials for efficient biosensing and biofuel cell.

Sustainable conversion of renewable biomass into high-performance electrode materials has attracted extensive scientific and technological attention. However, to our knowledge, the potential of biomass derived carbon in biosensors and biofuel cells (BFCs) developments remains to be explored. Herein, the carbon nanorods assembled coral-like hierarchical meso-macroporous carbon (CN-CHMC) was synthesized as a sustainable electrode material to construct biosensor and lactate/air BFC. The CN-CHMC from cucumber (Cucumis sativus) possesses porous structure and plentiful defects, which not only facilitate the effective immobilization of enzymes but also accelerate electron transfer on the bioelectrode surfaces. As an electrochemical lactate biosensor, the CN-CHMC-based biosensor exhibits a wider linear range with lower detection limit (3.6 µM) and higher sensitivities (57.18 and 30.99 µA mM-1 cm-2) compared to carbon nanotube (CNT)-based biosensor. The feasibility of CN-CHMC-based biosensor in practical analysis is demonstrated by detecting lactate contents in real samples. By coupling with bilirubin oxidase-based biocathode, the lactate/air BFC equipped with CN-CHMC reveals a higher output power (112.7 µW cm-2) than that of CNT-based BFC. More interestingly, the lactate/air BFC demonstrates the ability to harvest energy from multi-component samples. The application of CN-CHMC may provide a new avenue to synthesize electrode materials with economical cost and excellent electrochemical activity.