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Bone defects pose significant challenges in healthcare, with over 2 million bone repair surgeries performed globally each year. As a burgeoning force in the field of bone tissue engineering, 3D printing offers novel solutions to traditional bone transplantation procedures. However, current 3D-printed bone scaffolds still face three critical challenges in material selection, printing methods, cellular self-organization and co-culture, significantly impeding their clinical application. In this comprehensive review, we delve into the performance criteria that ideal bone scaffolds should possess, with a particular focus on the three core challenges faced by 3D printing technology during clinical translation. We summarize the latest advancements in non-traditional materials and advanced printing techniques, emphasizing the importance of integrating organ-like technologies with bioprinting. This combined approach enables more precise simulation of natural tissue structure and function. Our aim in writing this review is to propose effective strategies to address these challenges and promote the clinical translation of 3D-printed scaffolds for bone defect treatment. [ABSTRACT FROM AUTHOR]

The dressing that promotes scarless healing is essential for both normal function and aesthetics after a wound. With a deeper understanding of the mechanisms involved in scar formation during the wound healing process, the ideal dressing becomes clearer and more promising. For instance, the yes‐associated transcriptional regulator (YAP) has been extensively studied as a key gene involved in regulating scar formation. However, there has been limited attention given to pectolinarin, a natural flavonoid that may exhibit strong binding affinity to YAP, in the context of scarless healing. In this study, we successfully developed a temperature‐sensitive Pluronic@F‐127 hydrogel as a platform for delivering pectolinarin to promote scarless wound healing. The bioactive pectolinarin was released from the hydrogel, effectively enhancing endothelial cell migration, proliferation and the expression of angiogenesis‐related genes. Additionally, a concentration of 20 μg/mL of pectolinarin demonstrated remarkable antioxidant ability, capable of counteracting the detrimental effects of reactive oxygen species (ROS). Our results from rat wound healing models demonstrated that the hydrogel accelerated wound healing, promoting re‐epithelialization and facilitating skin appendage regeneration. Furthermore, we discovered that a concentration of 50 μg/mL of pectolinarin incorporated to the hydrogel exhibited the most favourable outcomes in terms of promoting wound healing and minimizing scar formation. Overall, our study highlights that the significant potential of locally released pectolinarin might substantially inhibit YAP and promoting scarless wound healing. [ABSTRACT FROM AUTHOR]

Non‐water‐limited canopy resistance (rcs, also known as the bulk stomatal resistance or surface resistance) is a critical variable in estimating potential evapotranspiration (PET), which is widely used in ecohydrology related fields. However, quantifying rcs is a challenging work. Here we develop an approach for estimating rcs over the globe. Comparing results over the globe and across 10 ET data sets (used as inputs), which are based on diverse mechanisms and algorithms, we find that the approach can capture canopy resistance well (mean correlation of 0.84 ± 0.04, mean relative Root Mean Squared Error of 4.4% ± 1.0%, and mean relative Mean Absolute Error of 5.8% ± 1.4%), and the estimated rcs are very close to those estimated using another method (R2 = 0.92), which is based on a quite different hypothesis that is only suitable for saturated regions. Based on these, we find that the rcs shows an overall increasing trend (0.43 ± 0.13 s m−1 year−1) over the globe (at 77.6% ± 3.9% of the land grid cells) during 1982–2014, and the air temperature dominates the variabilities of rcs in regions with decreasing rcs (mean relative contribution of 57.9% ± 11.4%), while air CO2 concentration controls the changes in rcs in regions with increasing rcs (mean relative contribution of 47.3% ± 8.0%). Moreover, we also find that the traditional PET estimator explicitly overestimates the increasing trends in PET, and tends to overestimate (underestimate) the increasing (decreasing) trends in regions with increasing (decreasing) PET. These findings can improve our knowledge on the complex water‐vegetation‐environment interactions and would be helpful for developing more accurate models for quantifying the impacts of global change on water resources. Key Points: An approach is developed to estimate the non‐water‐limited canopy resistance (rcs) over the globeChanges in Ta ([CO2]) dominate the variabilities of rcs in regions with decreasing (increasing) rcsTraditional potential evapotranspiration (PET) overestimates (underestimates) the increasing (decreasing) PET trends in regions with increasing (decreasing) PET [ABSTRACT FROM AUTHOR]

[Display omitted] • High-performance interfacial heterojunction, formed between OH PCN and Nb 2 O 5 via C O H O Nb bond, accelerates the carrier transfer from conduction band of Nb 2 O 5 to that of OH PCN. • The electron transfer occurred in C O H O Nb bond induces electron-rich O site, which act as an ideal adsorption site for phenol through O H ··· O hydrogen bond. • Super active site, formed by integrating triazine ring site on OH-PCN (activation site for O 2) and O site on Nb 2 O 5 (adsorption site for phenol), facilitates the evolution of O 2 and in-situ photomineralization of phenol. Promoting the carrier separation and surface catalytic reaction are critically important to maximize photocatalytic efficiency. Hydroxyl group-modified polymeric carbon nitride/niobium pentoxide nanosheets heterojunction (OH-PCN/Nb 2 O 5) is designed for fast electron transfer from Nb 2 O 5 to OH-PCN. Electron-rich O site, induced by electron transfer occurred in C O H O Nb bond, acts as an ideal adsorption site for phenol through O H⋯O bond. Super active site, formed by integrating triazine ring site on OH-PCN (activation site for O 2) and O site on Nb 2 O 5 (adsorption site for phenol), facilitates the evolution of O 2 and in-situ photomineralization of phenol. OH-PCN/Nb 2 O 5 shows a more than 8-fold improvement in phenol photodegradation efficiency than PCN. Briefly, this work provides insights on constructing interfacial super active sites by interface control of catalysts and in turn dramatically improving the photocatalytic performance. [ABSTRACT FROM AUTHOR]

China has experienced significant vegetation greening over recent decades. Vegetation greening may regulate the effective vegetation available water capacity (EVAWC), which determines the root zone water availability for evapotranspiration. EVAWC is one of the most important factors controlling vegetation growth and ecosystem resilience. Despite its importance, quantifying EVAWC at large scale is challenging due to limited observations of soil properties and insufficient understanding of underlying physical processes. Thus, to what extent changes in EVAWC are driven by vegetation and climate change is still unclear. Here, we establish a physics‐based, data‐driven stochastic approach to examine the spatiotemporal variability of the EVAWC and its potential drivers over China, with the consideration of vegetation and climate dynamics. The major strength of our approach is that it does not require observations related to soil properties as inputs, but only needs a few simple hydrometeorological and remotely sensed vegetation parameters that can be easily obtained. On average, we find that vegetation changes tend to increase EVAWC over 71.0 ± 3.9% of the total land area in China, while climate variabilities tend to reduce EVAWC over 73.7 ± 9.5% of the land area. More importantly, the potential increase in EVAWC resulting from vegetation changes is offset by climate variability. As a result, the changes in EVAWC over recent decades are generally dominated by climate variabilities (relative contribution of 82.7 ± 9.6%) rather than vegetation changes, especially in humid and semihumid areas. Our results suggest that vegetation greening in China has subordinate impacts on EVAWC, and ecosystem resilience is mainly dominated by the local climate. Key Points: A stochastic approach is developed to examine changes in effective vegetation available water capacity (EVAWC) over ChinaThis approach does not require observations related to soil properties as inputs, which are difficult to be obtained and have uncertaintiesChanges in EVAWC are dominated by climate variabilities (relative contribution 82.7 ± 9.6%) rather than vegetation changes [ABSTRACT FROM AUTHOR]

Inhibitor of nuclear factor kappa-B kinase subunit beta (IKK β) is one of important kinases in inflammation to phosphorylate inhibitor of nuclear factor kappa-B (I κ B α) and then activate nuclear factor kappa-B (NF- κ B). Inhibition of IKK β has been a therapeutic strategy for inflammatory and autoimmune diseases. Here we report that IKK β is constitutively activated in healthy donors and healthy Ikkβ C46A (cysteine 46 mutated to alanine) knock-in mice although they possess intensive IKK β –I κ B α –NF- κ B signaling activation. These indicate that IKK β activation probably plays homeostatic role instead of causing inflammation. Compared to Ikkβ WT littermates, lipopolysaccharides (LPS) could induce high mortality rate in Ikkβ C46A mice which is correlated to breaking the homeostasis by intensively activating p-I κ B α –NF- κ B signaling and inhibiting phosphorylation of 5ʹ adenosine monophosphate-activated protein kinase (p-AMPK) expression. We then demonstrated that IKK β kinase domain (KD) phosphorylates AMPK α 1 via interacting with residues Thr183, Ser184, and Thr388, while IKK β helix–loop–helix motifs is essential to phosphorylate I κ B α according to the previous reports. Kinase assay further demonstrated that IKK β simultaneously catalyzes phosphorylation of AMPK and I κ B α to mediate homeostasis. Accordingly, activation of AMPK rather than inhibition of IKK β could substantially rescue LPS-induced mortality in Ikkβ C46A mice by rebuilding the homeostasis. We conclude that IKK β activates AMPK to restrict inflammation and IKK β mediates homeostatic function in inflammation via competitively phosphorylating AMPK and I κ B α. The dual and opposite role of inhibitor of nuclear factor kappa-B kinase subunit beta (IKK β) restricts and induces inflammation by phosphorylating 5ʹ adenosine monophosphate-activated protein kinase (AMPK) and inhibitor of nuclear factor kappa-B (I κ B α). [Display omitted] [ABSTRACT FROM AUTHOR]

Potential evapotranspiration (PET) is a key input to hydrologic models simulating the atmospheric water demand. Thus, uncertainties in PET would result in considerable uncertainty in model outputs. Among numerous PET algorithms, the Penman‐Monteith equation (PM equation) is most widely used because of its clear physical basis and acceptable estimation. However, PM equation has a physical limitation resulting from the linear approximation of the saturation water vapor pressure differences between the evaporation surface and the surrounding air, which can affect markedly the responses of PET to air warming. By considering a modified PM‐type evaporation model, we revisited the global drying trends based on the widely used Palmer Drought Severity Index (PDSI). We demonstrate that the studies, which based on the classic PM equation, often overestimate the effects of air warming on global drying trends. Particularly, the PET_PM (PET calculated using the classic PM equation) driven PDSI, overestimates global mean drought‐affected areas by 60%, drought intensity by 65%, and drought duration by 35% on average over the globe, and tends to overestimate drying trends in areas that are drying and underestimate wetting trends in areas that are becoming wetter. Key Points: Modifying PM evaporation model by introducing the nonlinear relationship between water vapor and temperaturePM evaporation model overestimates the effects of air warming on potential evapotranspirationThe drought index driven by PM‐type PET overestimates the global drying trends considerably [ABSTRACT FROM AUTHOR]

Regulating the surface properties of catalysts to control the selectivity of a reaction is a fascinating approach. Bulk polymeric carbon nitride exhibits a poor N-phenylhydroxylamine yield in nitrobenzene reduction reaction mainly due to the uncontrollable condensation side reactions. Thus, adjusting the structure of the catalyst was key to solving the above issue. Herein, –OH groups-modified polymeric carbon nitride was prepared via a simple hydrothermal treatment. With the introduced –OH groups replacing the terminal amino groups (–NH2) at the surface of the polymeric carbon nitride, a 3-fold increase in reaction rate was achieved, along with a high selectivity toward N-phenylhydroxylamine (ca. 80%). The introduced –OH group was found to be beneficial to the adsorption of the nitrobenzene, based on the density functional theory (DFT) calculation. It could also lower the recombination rate of photoinduced electron–hole pairs, which would accelerate the photocatalytic oxidation of isopropanol and supply more protons to participate in the hydrogen-transfer process. Moreover, the elevated conduction band position after –OH modification would provide high energetic photogenerated electrons to promote the reduction of nitrobenzene. These are all important to guarantee the highly selective production of N-phenylhydroxylamine. This paper not only provides a simple and green approach for the modification of polymeric carbon nitride toward an efficient photocatalyst, but also sheds light on the further study of the selective hydrogenation. [ABSTRACT FROM AUTHOR]

Physical agricultural drought indices generally use soil moisture to represent root‐zone water availability (RZWA). The uncertainty in root‐zone properties, especially in deep‐rooting regions, may lead to significant uncertainty in the results. This study adopted a conceptual model that requires no specific root‐zone properties to model the RZWA. A RZWA‐based drought index (AgDI) was then developed by standardizing the root‐zone water deficit. A comparison over 20 catchments with different terrain and vegetation demonstrated the effectiveness of AgDI in characterizing agricultural droughts, with the correlations between vegetation indices (normalized difference vegetation index [NDVI] and gross primary productivity [GPP]) and AgDI (mean ~0.54) being significantly higher than those between the same vegetation indices and the Palmer Drought Severity Index (PDSI, ~0.22), Standardized Precipitation‐Evapotranspiration Index (SPEI, ~0.33), and Standardized Soil moisture Index (SSI, ~0.37). Compared to the SSI, the AgDI was not equally advantageous everywhere, but it generally showed better performance in deep‐rooting regions. Plain Language Summary: Agricultural drought can adversely affect agroecosystems; therefore its detection and quantification are essential for hazard mitigation. Limited root‐zone water availability (RZWA) is the direct cause of agricultural drought. Generally, physical agricultural drought indices are based on the soil moisture of several soil layers (e.g., 0–100 cm). However, these methods may result in uncertainties because the soil moisture in such soil profiles may not fully reflect the RZWA, especially in deep‐rooting ecosystems. In addition, estimation of RZWA is challenging because of the uncertainty in root‐zone properties (e.g., roots distribution and hydraulic properties). To overcome these known limitations, we developed a conceptual model that does not require root zone properties to model the RZWA, using which a new agricultural drought index (AgDI) was then developed by standardizing the root zone water deficit. A comparison study over 20 catchments with different terrain and vegetation properties showed that the AgDI is more effective in characterizing agricultural drought than the PDSI, SPEI and SSI. Compared to the soil moisture based SSI, the AgDI is not advantageous everywhere but generally exhibits better performance in deep‐rooting regions. We also found that the meteorological droughts are the main triggers of, but do not always lead to, agricultural droughts. Key Points: RZWA was inferred by using a conceptual model needing no specified root‐zone propertiesOur RZWA‐based drought index (AgDI) is effective in characterizing agricultural droughtsThe AgDI generally performs better in deep‐rooting regions than soil moisture based indices [ABSTRACT FROM AUTHOR]

Understanding hydrological processes is essential for management of water resources and for promoting catchment sustainability. In karst regions, landscapes are spatially heterogeneous and include discontinuous soil distribution, and complex networks of matrices and conduits in hillslopes and depressions, which result in variation in hydrological processes. However, most previous studies have mainly focused on the effects of the distribution of soil depth and the fast‐slow flow in the matrices and conduits on hydrological processes and ignored the different hydrological processes related to hillslopes and depressions. This study improved the VarKarst model by adding randomly distributed soil and epikarst depths (RSE), fast‐slow flow (FS), and hillslopes and depressions (HD). The improved model was calibrated and validated in six large catchments (1,213–5,454 km2) and one small catchment (1.25 km2). Results showed that the schemes by combining FS and HD (Scenario FS + HD) and combining RSE, FS, and HD (Scenario RSE + FS + HD) improved model performance (calibrated and validated KGE ranged from 0.54 to 0.89 and AIC ranged from −336.49 to 669.77) compared models that included other schemes (original VarKarst, Scenario RSE, Scenario FS, Scenario HD, and Scenario RSE + FS), especially when reproducing discharge of peaks and recessions. These results suggest that there is a need to separate the hillslopes and depressions when modeling karstic hydrological processes. Key Points: Hillslopes and depressions have different hydrological processes in karst regionsImproved VarKarst model better reproduced discharge of peaks and recessions compared to the original modelThere is a need to separate the hillslopes and depressions in modeling hydrological processes in karst regions [ABSTRACT FROM AUTHOR]

The critical zone (CZ) represents the intersection of the biosphere with the atmosphere, hydrosphere and lithosphere. Understanding the hydrological processes and human impact factors on the CZ is fundamental to sustainable water resources management for agroforestry. Transpiration (T) is an important component of terrestrial evapotranspiration (ET), and understanding the time lag (TL) between vegetation transpiration and meteorological factors can improve our knowledge of the mechanisms of vegetation adaptability to a changing environment. However, the controlling factors on the TL remain poorly understood. Therefore, the objective of this study is identifying the temporal dynamics of key controlling factors on the TL, using a typical deciduous broad-leaved tree species (Zenia insigins Chun) of CZ in subtropical humid karst regions. This species is used as an example to explore the characteristics of the TL between SF (sap flow) and hydro-meteorological forcing. Sap flow in these 6 trees was monitored using the thermal dissipation probes (TDP). Results showed that: (1) the peak of diurnal sap flow generally lagged behind PAR but preceded Ta (air temperature), RH (relative humidity) and VPD (vapor pressure deficit), with the mean TL of −67.4 min (PAR), 90.5 min (Ta), 91.6 min (RH) and 92.9 min (VPD), respectively; (2) TL had no significant relationships with the daily mean meteorological factors and soil moisture, but was highly (R2>0.66) correlated to CRs (changing rates of meteorological factors) in the morning; (3) At seasonal scale, the sap flow rate and TL both were controlled by the seasonality of precipitation and temperature. Overall, the seasonality of the TL was caused by plants' high water loss and strongly active physiological response in hot seasons, leading to close stomata earlier than in cold seasons; (4) The reason why CRs proposed can explain the TL better than mean values of metrological factors is that the CRs considered the distribution and change processes of metrological factors in the daytime. This study may be helpful for understanding the physiological response of vegetation to climatic change, and may be useful for constructing models to simulate transpiration processes more accurately during a day. [ABSTRACT FROM AUTHOR]

Polymeric carbon nitride is a promising candidate for metal-free photocatalysis, but it is hampered by low activity due to poor carrier separation efficiency and lack of active sites. We have constructed a bifunctionally-modified structure, containing cyano groups internally and carboxyl groups on the surface, that was about 205 times more active than unmodified carbon nitride. The internal cyano groups enhanced the photoelectric performance of carbon nitride, while the surface carboxyl groups acted as active sites to promote hydrogen production. It is anticipated that this work will inform the rational design of polymeric carbon nitride and inspire similar attempts to modify polymers. [ABSTRACT FROM AUTHOR]

ABSTRACT: Southwest (SW) China is a drought prone region. Knowledge of the risks and coupling characteristics of drought duration and severity is essential for hazards mitigation and water management. Based on probability distributions, copulas, Mann–Kendall test, overlapping moving windows approach and the self‐calibrated Palmer Drought Severity Index (PDSI) at 69 stations (1959–2013), this study focused on the trends and spatial variability (SV) of (joint) probability drought duration and severity in SW China, and further investigated the potential contributors by analysing the behaviours of precipitation (P), temperature (T), relative humidity (RH), wind speed (WS), atmospheric moisture flux (MF) and divergence (MFD). In particular, the SV was represented by the standard deviation, the drought duration and severity were characterized by the number of months with PDSI < −0.5 in a year [drought months (DM)] and the absolute mean PDSI in drought months (DS), respectively. Results showed that, the DM, DS, DM5, DS5 (5‐year return levels for DM and DS) increased by 0.058 month year−2, 0.012 month−1 year−1, 0.039 month year−2, and 0.009 month−1 year−1, respectively, and the joint return period T(DM > 4,DS > 2) decreased by −0.20 year year−1. Furthermore, due to the decreasing SV in P, T, RH, WS, MF, and MFD, SV of DM5, DS5 and T(DM > 4,DS > 2) significantly decreased in the past decades, by −0.003 month year−2, −0.006 month−1 year−1 and −0.03 year year−1, respectively. These results indicated that drought risks and severity increased significantly in the past decades over SW China. Most importantly, the decreasing SV implied that drought risks and severity might have become more homogeneous in this region. In other words, droughts became more widely spread throughout SW China in the past decades. Therefore, water agencies and governments should be more proactive in seeking measures to improve water resources management and drought mitigation in this region. [ABSTRACT FROM AUTHOR]

This study proposes a hydrological drought index, the standardized wetness index (SWI), by combining the structure of the Standardized Precipitation-Evapotranspiration Index and actual-evaporation-based residual water-energy ratio, in which actual evaporation is estimated using the Budyko hypothesis. The SWI requires three parameters-precipitation, potential evaporation, and parameter [ABSTRACT FROM AUTHOR]