Targeting mitochondrial quality control with melatonin has been found promising for attenuating diabetic cardiomyopathy (DCM), although the underlying mechanisms remain largely undefined. Activation ...of SIRT6 and melatonin membrane receptors exerts cardioprotective effects while little is known about their roles during DCM. Using high‐fat diet‐streptozotocin‐induced diabetic rat model, we found that prolonged diabetes significantly decreased nocturnal circulatory melatonin and heart melatonin levels, reduced the expressions of cardiac melatonin membrane receptors, and decreased myocardial SIRT6 and AMPK‐PGC‐1α‐AKT signaling. 16 weeks of melatonin treatment inhibited the progression of DCM and the following myocardial ischemia‐reperfusion (MI/R) injury by reducing mitochondrial fission, enhancing mitochondrial biogenesis and mitophagy via re‐activating SIRT6 and AMPK‐PGC‐1α‐AKT signaling. After the induction of diabetes, adeno‐associated virus carrying SIRT6‐specific small hairpin RNA or luzindole was delivered to the animals. We showed that SIRT6 knockdown or antagonizing melatonin receptors abolished the protective effects of melatonin against mitochondrial dysfunction as evidenced by aggravated mitochondrial fission and reduced mitochondrial biogenesis and mitophagy. Additionally, SIRT6 shRNA or luzindole inhibited melatonin‐induced AMPK‐PGC‐1α‐AKT activation as well as its cardioprotective actions. Collectively, we demonstrated that long‐term melatonin treatment attenuated the progression of DCM and reduced myocardial vulnerability to MI/R injury through preserving mitochondrial quality control. Melatonin membrane receptor‐mediated SIRT6‐AMPK‐PGC‐1α‐AKT axis played a key role in this process. Targeting SIRT6 with melatonin treatment may be a promising strategy for attenuating DCM and reducing myocardial vulnerability to ischemia‐reperfusion injury in diabetic patients.
Lithium-oxygen batteries with ultrahigh energy density have received considerable attention as of the future energy storage technologies. The development of effective electrocatalysts and a ...corresponding working mechanism during cycling are critically important for lithium-oxygen batteries. Here, a single cobalt atom electrocatalyst is synthesized for lithium-oxygen batteries by a polymer encapsulation strategy. The isolated moieties of single atom catalysts can effectively regulate the distribution of active sites to form micrometre-sized flower-like lithium peroxide and promote the decomposition of lithium peroxide by a one-electron pathway. The battery with single cobalt atoms can operate with high round-trip efficiency (86.2%) and long-term stability (218 days), which is superior to a commercial 5 wt% platinum/carbon catalyst. We reveal that the synergy between a single atom and the support endows the catalyst with excellent stability and durability. The promising results provide insights into the design of highly efficient catalysts for lithium-oxygen batteries and greatly expand the scope of future investigation.
A photoinduced flexible Li‐CO2 battery with well‐designed, hierarchical porous, and free‐standing In2S3@CNT/SS (ICS) as a bifunctional photoelectrode to accelerate both the CO2 reduction and ...evolution reactions (CDRR and CDER) is presented. The photoinduced Li‐CO2 battery achieved a record‐high discharge voltage of 3.14 V, surpassing the thermodynamic limit of 2.80 V, and an ultra‐low charge voltage of 3.20 V, achieving a round trip efficiency of 98.1 %, which is the highest value ever reported (<80 %) so far. These excellent properties can be ascribed to the hierarchical porous and free‐standing structure of ICS, as well as the key role of photogenerated electrons and holes during discharging and charging processes. A mechanism is proposed for pre‐activating CO2 by reducing In3+ to In+ under light illumination. The mechanism of the bifunctional light‐assisted process provides insight into photoinduced Li‐CO2 batteries and contributes to resolving the major setbacks of the system.
Battery life on Mars: A photoinduced flexible Li‐CO2 battery with hierarchical, porous, and free‐standing In2S3@CNT/SS as a bifunctional photoelectrode to accelerate both CO2 reduction and evolution is presented. The Li‐CO2 battery achieved a record‐high discharge voltage of 3.14 V (thermodynamic limit: 2.80 V), and an ultra‐low charge voltage of 3.20 V, and a roundtrip efficiency of 98.1 %.
Herein, an electroreductive carboxylation of organic carbon‐halogen bonds (X=Br and Cl) promoted by catalytic amounts of naphthalene as an organic mediator is reported. This transformation proceeds ...smoothly under mild conditions with a broad substrate scope of 59 examples, affording the valuable and versatile carboxylic acids in moderate to excellent yields without the need of costly transition metal, wasted stoichiometric metal reductants, or sacrificial anodes. Further late‐stage carboxylations of natural product and drug derivatives demonstrate its synthetic utility. Mechanistic studies confirmed the activation of carbon‐halogen bonds via single‐electron transfer and the key role of naphthalene in this reaction.
A general and metal‐free method for the electroreductive carboxylation of carbon‐halogen bonds has been developed to obtain carboxylated compounds in the presence of catalytic amounts of naphthalene as a mediator. This reaction exhibits a broad substrate scope, and is shown to be a powerful approach for the late‐stage carboxylation of natural product and drug derivatives.
Photoassisted electrochemical reaction is regarded as an effective approach to reduce the overpotential of lithium–oxygen (Li–O2) batteries. However, the achievement of both broadband absorption and ...long term battery cycling stability are still a formidable challenge. Herein, an oxygen vacancy‐mediated fast kinetics for a photoassisted Li–O2 system is developed with a silver/bismuth molybdate (Ag/Bi2MoO6) hybrid cathode. The cathode can offer both double advantages for light absorption covering UV to visible region and excellent electrochemical activity for O2. Upon discharging, the photoexcited electrons from Ag nanoplate based on the localized surface plasmon resonance (LSPR) are injected into the oxygen vacancy in Bi2MoO6. The fast oxygen reaction kinetics generate the amorphous Li2O2, and the discharge plateau is improved to 3.05 V. Upon charging, the photoexcited holes are capable to decompose amorphous Li2O2 promptly, yielding a very low charge plateau of 3.25 V. A first cycle round‐trip efficiency is 93.8% and retention of 70% over 500 h, which is the longest cycle life ever reported in photoassisted Li–O2 batteries. This work offers a general and reliable strategy for boosting the electrochemical kinetics by tailoring the crystalline of Li2O2 with wide‐band light.
A facile oxygen vacancy‐mediated fast kinetics for an ultrawide band photoassisted Li–O2 system is developed. The bifunctional Ag/Bi2MoO6 cathode is favorable to promoting the oxygen reduction reaction and oxygen evolution reaction kinetics due to the discharge products is amorphous Li2O2. The reaction mechanism is revealed by in situ X‐ray diffraction and Raman spectroscopy.
The asymmetric synthesis of Si‐stereogenic silanes has attracted great attention due to the increasing values of Si‐containing functional molecules in synthetic chemistry, medicinal chemistry, and ...material chemistry. Merging organosilicon chemistry with transition‐metal‐catalyzed C−H approach has led to rich sets of new reactions holding great synthetic values. This Minireview aims to summarize the advances in the construction of Si‐stereogenic silanes through the transition‐metal‐catalyzed C−H activation approach.
The preparation of chiral Si‐stereogenic silanes, a class of functional molecules with increasing values in synthetic chemistry, medicinal chemistry, and material chemistry, via transition‐metal‐catalyzed C−H activation approach is an elegant and attractive manner, in short steps from simple starting materials. This Minireview summarizes the advances in construction of Si‐stereogenic silanes by using this approach as well as future perspectives.
The present study reports an unprecedented protocol for the phosphonylation of unactivated C(sp3)−H bonds. By utilizing 1 mol % 4DPAIPN (1,2,3,5‐tetrakis(diphenylamino)‐4,6‐dicyanobenzene) as the ...catalyst, satisfactory yields of γ‐phosphonylated amides are obtained through a visible‐light‐induced reaction between N‐((4‐cyanobenzoyl)oxy)alkanamides and 9‐fluorenyl o‐phenylene phosphite at room temperature. This protocol demonstrates broad substrate scope and wide functional group compatibility.
Chemoselective phosphonylation of unactivated C(sp3)−H bond distal to the amide group was achieved at room temperature under transition‐metal‐free, photocatalyzed conditions.
The photoassisted lithium–oxygen (Li–O2) system has emerged as an important direction for future development by effectively reducing the large overpotential in Li–O2 batteries. However, the ...advancement is greatly hindered by the rapidly recombined photoexcited electrons and holes upon the discharging and charging processes. Herein, a breakthrough is made in overcoming these challenges by developing a new magnetic and optical field multi‐assisted Li–O2 battery with 3D porous NiO nanosheets on the Ni foam (NiO/FNi) as a photoelectrode. Under illumination, the photogenerated electrons and holes of the NiO/FNi photoelectrode play a key role in reducing the overpotential during discharging and charging, respectively. By introducing the external magnetic field, the Lorentz force acts oppositely on the photogenerated electrons and holes, thereby suppressing the recombination of charge carriers. The magnetic and optical field multi‐assisted Li–O2 battery achieves an ultralow charge potential of 2.73 V, a high energy efficiency of 96.7%, and good cycling stability. This external magnetic and optical field multi‐assisted technology paves a new way of developing high‐performance Li–O2 batteries and other energy storage systems.
A renewable magnetic and optical field multi‐assisted Li–O2 battery is developed with porous NiO on the Ni foam as a photoelectrode. The battery achieves an ultralow charge potential of 2.73 V, a high energy efficiency of 96.7%, and good cycling stability. The effect mechanism of the improved battery performance with magnetic field and optical field is revealed.
Directly converting and storing abundant solar energy in next‐generation energy storage devices is of central importance to build a sustainable society. Herein, a new prototype of a light‐promoted ...rechargeable and flexible Li‐CO2 battery with a TiO2/carbon cloth (CC) cathode is reported for the direct utilization of solar energy to promote the kinetics of the carbon dioxide reduction reaction and carbon dioxide evolution reaction (CO2ER). Under illumination, photoelectrons are generated in the conduction band of TiO2/CC, followed by the enhancing diffusion of electrons and lithium ions during the discharge process. The photoelectrons on the cathode surface can regulate the morphology of the discharge product Li2CO3, contributing to boosting the kinetics of the subsequent CO2ER process. In the reverse charge process, photogenerated holes can favor the decomposition of Li2CO3, leading to a negative charge potential of 2.88 V without increased polarization over ≈60 h of cycling. Owing to an ultralow overpotential of 0.06 V between the discharge and charge process, an ultrahigh energy efficiency of 97.9% is attained under illumination. The introduction of a light‐promoted flexible Li‐CO2 battery can pave the way toward developing the use of solar energy to address the charging overpotential of conventional Li‐CO2 batteries.
A renewable light‐promoted flexible Li‐CO2 battery is developed inspired by the photoenergy conversion and utilization concept. The utilization of solar light can effectively alleviate the charge polarization and promote the Li+ diffusion and mass transfer, resulting in considerable improvement of the kinetics of the carbon dioxide reduction reaction and carbon dioxide evolution reaction processes in the Li‐CO2 battery.
► We selected an efficient light source for the culture of tomato young plants. ► The growth and leaf development were studied under different light intensities. ► We examined the growth and ...development mechanisms associated with lighting intensity. ► The PPFD of 300μmolm−2s−1 of R:B=1:1 LED light was the suitable light source.
We used red light-emitting diodes (LEDs, R) and blue light-emitting diodes (LEDs, B) to obtain the different light intensities of uniform spectra and investigated the effects of different light intensities on growth and leaf development of young tomato plants. The results showed that fresh weight, dry weight, stem diameter and health index were superior in plants grown under 300, 450 and 550μmolm−2s−1. The energy efficiency was highest under 300μmolm−2s−1. When photosynthetic photon flux density (PPFD) increased from 50 to 550μmolm−2s−1, a decrease in the specific leaf area (SLA) was observed. Under 300 and 450μmolm−2s−1, the thickness of leaves, palisade parenchyma and spongy parenchyma were the bigger, and the stomatal frequency and stomatal area per unit leaf area were also higher. The highest net photosynthesis rate (Pn) was observed under 300μmolm−2s−1. Our results implied that, compared to other light treatments, 300μmolm−2s−1 was more suitable for the culture of young tomato plants and there was no substantial gain from a PPFD above 300μmolm−2s−1.
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