Enhanced weathering (EW) of (ultra)mafic rocks is widely considered as a promising option for carbon dioxide removal (CDR). However, accurately measuring its CDR potential remains unavailable due to ...sluggish weathering process. Previous models have estimated annual CDR potentials ranging from 1 to 95 Gt by 2100, with the maximum significantly exceeding the anthropogenic CO2 emissions in 2021 (approximately 41 Gt). This raises concerns that a misconception may arise, suggesting active mitigations of CO2 emissions might not be necessary. Herein, we address this issue by partitioning the CDR potential of EW into two components, flow-through and non-flow-through processes, and develop an experimentally-calibrated model to reduce discrepancies between previous theoretical and experimental weathering rates. Our model estimates the upper bound of CDR potentials to be 0.22 (±0.16) Gt annually and 17 (±13) Gt cumulatively by 2100, thereby emphasizing the significance and urgency to advance ultra-enhanced weathering strategies.
The carbon dioxide removal (CDR) potential of enhanced weathering was factored into flow-through and non-flow-through processes, based on considerations of CO2 mass flow from air into land. Display omitted
•Discrepancies exist in estimation of enhanced weathering's CO2 removal potential.•CO2 removal of weathering is evaluated with experimentally-calibrated parameters.•CO2 removal of weathering is limited mainly due to sluggish weathering kinetics.•Ultra-enhanced weathering is necessary to be a competitive CO2 removal option.
Although single-atomically dispersed metal-N
on carbon support (M-NC) has great potential in heterogeneous catalysis, the scalable synthesis of such single-atom catalysts (SACs) with high-loading ...metal-N
is greatly challenging since the loading and single-atomic dispersion have to be balanced at high temperature for forming metal-N
. Herein, we develop a general cascade anchoring strategy for the mass production of a series of M-NC SACs with a metal loading up to 12.1 wt%. Systematic investigation reveals that the chelation of metal ions, physical isolation of chelate complex upon high loading, and the binding with N-species at elevated temperature are essential to achieving high-loading M-NC SACs. As a demonstration, high-loading Fe-NC SAC shows superior electrocatalytic performance for O
reduction and Ni-NC SAC exhibits high electrocatalytic activity for CO
reduction. The strategy paves a universal way to produce stable M-NC SAC with high-density metal-N
sites for diverse high-performance applications.
Synthesis of monomer‐recyclable polyesters solely from CO2 and bulk olefins holds great potential in significantly reducing CO2 emissions and addressing the issue of plastic pollution. Due to the ...kinetic disadvantage of direct copolymerization of CO2 and bulk olefins compared to homopolymerization of bulk olefins, considerable research attention has been devoted to synthesis of polyester via the ring‐opening polymerization (ROP) of a six‐membered disubstituted lactone intermediate, 1,2‐ethylidene‐6‐vinyl‐tetrahydro‐2H‐pyran‐2‐one (ðoe¹‐L), obtained from telomerization of CO2 and 1,3‐butadiene. However, the conjugate olefin on the six‐membered ring of ðoe¹‐L leads to serious Michael addition side reactions. Thus, the selective ROP of ðoe¹‐L, which can precisely control the repeating unit for the production of polyesters potentially amenable to efficient monomer recycling, remains an unresolved challenge. Herein, the first example of selective ROP of ðoe¹‐L is reported using a combination of organobase and N,N′‐Bis3,5‐bis(trifluoromethyl)phenylurea as the catalytic system. Systematic modifications of the substituent of the urea show that the presence of electron‐deficient 3,5‐bis(trifluoromethyl)‐phenyl groups is the key to the extraordinary selectivity of ring opening over Michael addition. Efficient monomer recovery of oligo(ðoe¹‐L) is also achieved under mild catalytic conditions.
Lung cancer is the most commonly diagnosed cancer worldwide, and metastasis in lung cancer is the leading cause of cancer‐related deaths. Thus, understanding the mechanism of lung cancer metastasis ...will improve the diagnosis and treatment of lung cancer patients. Herein, we found that expression of cluster of differentiation 109 (CD109) was correlated with the invasive and metastatic capacities of lung adenocarcinoma cells. CD109 is upregulated in tumorous tissues, and CD109 overexpression was associated with tumor progression, distant metastasis, and a poor prognosis in patient with lung adenocarcinoma. Mechanistically, expression of CD109 regulates protein kinase B (AKT)/mammalian target of rapamycin (mTOR) signaling via its association with the epidermal growth factor receptor (EGFR). Inhibition of CD109 decreases EGFR phosphorylation, diminishes EGF‐elicited activation of AKT/mTOR, and sensitizes tumor cells to an EGFR inhibitor. Taken together, our results show that CD109 is a potential diagnostic and therapeutic target in lung cancer patients.
CD109 promotes lung cancer metastasis through promoting EGFR‐AKT‐mTOR signaling and CD109 is an independent prognostic marker for lung adenocarcinoma.
The discrepancy between current CO2 emission trend and the targeted 1.5 °C warming requires the implementation of carbon dioxide removal (CDR) technologies. Among the engineered CDRs, enhanced ...weathering (EW) is expected to exhibit substantial potential for CO2 removal, owing to the availability of abundant reserves of ultramafic rocks and demonstration of worldwide liming practice. While the shrinking core model (SCM) has been commonly adopted in previous theoretical and experimental studies, there still lacks a comprehensive assessment on the impacts of model parameters, such as rock particle size, size distribution, weathering rate and time length on the weathering kinetics and the resultant CDR potential. Herein, this study incorporates particle size distribution of rock powder into the surface reaction-controlled SCM, and conducts sensitivity analysis on EW’s CDR potential quantitatively. Even fully powered by low-carbon energy in the optimistic case, the application of EW with olivine only achieves maximum CDR per unit of rock and energy consumption of 0.01 kg CO2 per kg rock and 19 g per kWh at size of 8 and 22 μm respectively, indicating the limitations of EW. The derived optimal application parameters with olivine powers within 3.7–79 μm provide valuable insights into the practical real-world applications to achieve net CO2 removal.
Synthesis of monomer-recyclable polyesters solely from CO
and bulk olefins holds great potential in significantly reducing CO
emissions and addressing the issue of plastic pollution. Due to the ...kinetic disadvantage of direct copolymerization of CO
and bulk olefins compared to homopolymerization of bulk olefins, considerable research attention has been devoted to synthesis of polyester via the ring-opening polymerization (ROP) of a six-membered disubstituted lactone intermediate, 1,2-ethylidene-6-vinyl-tetrahydro-2H-pyran-2-one (𝜹-L), obtained from telomerization of CO
and 1,3-butadiene. However, the conjugate olefin on the six-membered ring of 𝜹-L leads to serious Michael addition side reactions. Thus, the selective ROP of 𝜹-L, which can precisely control the repeating unit for the production of polyesters potentially amenable to efficient monomer recycling, remains an unresolved challenge. Herein, the first example of selective ROP of 𝜹-L is reported using a combination of organobase and N,N'-Bis3,5-bis(trifluoromethyl)phenylurea as the catalytic system. Systematic modifications of the substituent of the urea show that the presence of electron-deficient 3,5-bis(trifluoromethyl)-phenyl groups is the key to the extraordinary selectivity of ring opening over Michael addition. Efficient monomer recovery of oligo(𝜹-L) is also achieved under mild catalytic conditions.
Aerobic organisms must rely on abundant intracellular thiols to reductively protect various vital functional units, especially ubiquitous zinc(II) thiolate sites of proteins, from deleterious ...oxidations resulting from oxidizing environments. Disclosed here is the first well‐defined model study for reactions between zinc(II) thiolate complexes and copper(II) complexes. Among all the studied ligands of copper(II), diethyldithiocarbamate (DTC) displays a unique redox‐tuning ability that enables copper(II) to resist the reduction by thiols while retaining its ability to oxidize zinc(II) thiolates to form disulfides. This work proves for the first time that it is possible to develop oxidants to discriminate between thiols and zinc(II) thiolates, alluding to a new chemical principle for how oxidants, especially universal anticancer Cu(DTC)2, might circumvent the intracellular reductive defense around certain zinc(II) thiolate sites of proteins to kill malignant cells.
Oxidation tunes: Diethyldithiocarbamate (DTC) displays a unique redox‐tuning ability that enables copper(II) to resist the reduction by thiols while retaining its ability to oxidize zinc(II) thiolates to form disulfides. These studies provide molecular‐level insights into treatments of cancers with copper(II)/disulfiram.
Despite progress in the treatment of diabetic macular edema and diabetic retinopathy, the rate of lower fundus examination due to limitations of medical resources delays the diagnosis and treatment ...of diabetic retinopathy. Therefore, implementation of automated diabetic retinopathy screening program and the identification of more specific and sensitive biomarkers are important for facilitating the earlier detection of diabetic macular edema and diabetic retinopathy to decrease the prevalence of poor vision and blindness.
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