Nickel Single Atom Density-Dependent CO2 Efficient Electroreduction

The transition metal-nitrogen-carbon (M─N─C) with MNx sites has shown great potential in CO2 electroreduction (CO2RR) for producing high value-added C1 products. However, a comprehensive and profound understanding of the intrinsic relationship between the density of metal single atoms and the CO2RR performance is still lacking. Herein, a series of Ni single-atom catalysts is deliberately designed and prepared, anchored on layered N-doped graphene-like carbon (x Ni1@NG-900, where x represents the Ni loading, 900 refers to the temperature). By modulating the precursor, the density of Ni single atoms (DNi) can be finely tuned from 0.01 to 1.19 atoms nm-2. The CO2RR results demonstrate that the CO faradaic efficiency (FECO) predominantly increases from 13.4% to 96.2% as the DNi increased from 0 to 0.068 atoms nm-2. Then the FECO showed a slow increase from 96.2% to 98.2% at -0.82 V versus reversible hydrogen electrode (RHE) when DNi increased from 0.068 to 1.19 atoms nm-2. The theoretical calculations are in good agreement with experimental results, indicating a trade-off relationship between DNi and CO2RR performance. These findings reveal the crucial role of the density of Ni single atoms in determining the CO2RR performance of M─N─C catalysts.

Dual-sgRNA CRISPRa System for Enhanced MK-7 Production and Salmonella Infection Mitigation in Bacillus subtilis natto Applied to Caco-2 Cells

This study optimized the menaquinone-7 (MK-7) synthetic pathways in Bacillus subtilis (B. subtilis) natto NB205, a strain that originated from natto, to enhance its MK-7 production. Utilizing mutation breeding, we developed NBMK308, a mutant strain that demonstrated a significant 117.23% increase in MK-7 production. A comprehensive transcriptome analysis identified two key genes, ispA and ispE, as being critical in MK-7 synthesis. The dual-sgRNA CRISPRa system was utilized to achieve precise regulation of ispA and ispE in the newly engineered strain, A3E3. This strategic modulation resulted in a significant enhancement of MK-7 production, achieving increases of 20.02% and 201.41% compared to traditional overexpression systems and the original strain NB205, respectively. Furthermore, the fermentation supernatant from A3E3 notably inhibited Salmonella invasion in Caco-2 cells, showcasing its potential for combating such infections. The safety of the dual-sgRNA CRISPRa system was confirmed through cell assays. The utilization of the dual-sgRNA CRISPRa system in this study was crucial for the precise regulation of key genes in MK-7 synthesis, leading to a remarkable increase in production and demonstrating additional therapeutic potential in inhibiting pathogenic infections. This approach effectively combined the advantages of microbial fermentation and biotechnology, addressing health and nutritional challenges.

Navigating the AI Revolution: The Case for Precise Regulation in Health Care

Health care is undergoing a profound transformation through the integration of artificial intelligence (AI). However, the rapid integration and expansive growth of AI within health care systems present ethical and legal challenges that warrant careful consideration. In this viewpoint, the author argues that the health care domain, due to its complexity, requires specialized approaches to regulating AI. Precise regulation can provide clear guidelines for addressing these challenges, thereby ensuring ethical and legal AI implementations.

A MYB activator, DcMYB11c, regulates carrot anthocyanins accumulation in petiole but not taproot

The first domesticated carrots were thought to be purple carrots rich in anthocyanins. The anthocyanins biosynthesis in solid purple carrot taproot was regulated by DcMYB7 within P₃ region containing a gene cluster of six DcMYBs. Here, we described a MYB gene within the same region, DcMYB11c, which was highly expressed in the purple pigmented petioles. Overexpression of DcMYB11c in 'Kurodagosun' (KRD^G , orange taproot carrot with green petioles) and 'Qitouhuang' (QTH^G , yellow taproot carrot with green petioles) resulted in deep purple phenotype in the whole carrot plants indicating anthocyanins accumulation. Knockout of DcMYB11c in 'Deep Purple' (DPP^P , purple taproot carrot with purple petioles) through CRISPR/Cas9-based genome editing resulted in pale purple phenotype due to the dramatic decrease of anthocyanins content. DcMYB11c could induce the expression of DcbHLH3 and anthocyanins biosynthesis genes to jointly promote anthocyanins biosynthesis. Yeast one-hybrid assay (Y1H) and dual-luciferase reporter assay (LUC) revealed that DcMYB11c bound to the promoters of DcUCGXT1 and DcSAT1 and directly activated the expression of DcUCGXT1 and DcSAT1 responsible for anthocyanins glycosylation and acylation, respectively. Three transposons were present in the carrot cultivars with purple petioles but not in the carrot cultivars with green petioles. We revealed the core factor, DcMYB11c, involved in anthocyanins pigmentation in carrot purple petioles. This study provides new insights into precise regulation mechanism underlying anthocyanins biosynthesis in carrot. The orchestrated regulation mechanism in carrot might be conserved across the plant kingdom and useful for other researchers working on anthocyanins accumulation in different tissues.

Controlled Latent Heat Phase-Change Microcapsules for Temperature Regulation

Microencapsulation of phase-change materials (PCMs) is of great value and significance for improving energy efficiency and reducing carbon dioxide emissions. Here, highly controllable phase-change microcapsules (PCMCs) with hexadecane as the core material and polyurea as the shell material were developed for precise temperature regulation. A universal liquid-driven active flow focusing technique platform was used to adjust the diameter of PCMCs, and the shell thickness can be controlled by adjusting the monomer ratio. In synchronized regime, the droplet size is only related to the flow rate and excitation frequency, which can be accurately predicted by the scaling law. The fabricated PCMCs have uniform particle size with a coefficient of variation (CV) under 2%, smooth surface, and compact structure. Meanwhile, under the good protection of a polyurea shell, PCMCs exhibit fair phase-change performance, strong heat storage capacity, and good thermal stability. The PCMCs with different sizes and wall thickness show obvious differences in thermal properties. The feasibility of the fabricated hexadecane phase-change microcapsules in phase-change temperature regulation was verified by thermal analysis. These features indicate that the developed PCMCs by the active flow focusing technique platform have broad application prospects in thermal energy storage and thermal management.

MicroRNAs Are Involved in Regulating Plant Development and Stress Response through Fine-Tuning of TIR1/AFB-Dependent Auxin Signaling

Auxin, primarily indole-3-acetic acid (IAA), is a versatile signal molecule that regulates many aspects of plant growth, development, and stress response. Recently, microRNAs (miRNAs), a type of short non-coding RNA, have emerged as master regulators of the auxin response pathways by affecting auxin homeostasis and perception in plants. The combination of these miRNAs and the autoregulation of the auxin signaling pathways, as well as the interaction with other hormones, creates a regulatory network that controls the level of auxin perception and signal transduction to maintain signaling homeostasis. In this review, we will detail the miRNAs involved in auxin signaling to illustrate its in planta complex regulation.

Remarkable enhancement of bleomycin production through precise amplification of its biosynthetic gene cluster in Streptomyces verticillus

Amplification of biosynthetic gene clusters is important to increase secondary metabolite production. However, the copy number of amplified gene clusters is difficult to control precisely. In this study, the tandem amplification of a 70 kb bleomycin biosynthetic gene cluster was precisely regulated through the combined strategy of a ZouA-dependent DNA amplification system and double-reporter-guided recombinant selection in Streptomyces verticillus ATCC15003. The production of bleomycin in the recombinant strain containing six copies of the bleomycin gene cluster was 9.59-fold higher than that in the wild-type strain. The combined strategy used in this study is powerful and applicable for precisely regulating the amplification of gene clusters and improving the corresponding secondary metabolite production.

A Logic AND-Gated Sonogene Nanosystem for Precisely Regulating the Apoptosis of Tumor Cells

To date, many methods have been developed for inducing tumor cell death, such as using chemical drugs and radiation. However, all of them have a common problem, a lack of mechanisms for precisely regulating the death of tumor cells. It often leads to nonspecific death and systemic side effects. Therefore, the efficacy and further application of these traditional methods are limited. In this paper, a logic AND-gated sonogene nanosystem was designed for precisely regulating the apoptosis of tumor cells. The running of this system required two essential parts, MscL I92L channel protein and ultrasound. Ultrasound could open the MscL I92L protein channel which when expressed on cells triggers the influx and outflux of small molecules through the channel. When the channel is kept open for a long time, Ca²⁺ influx becomes excessive which in turn activates the Ca²⁺ apoptosis pathway of cells. The expression of MscL I92L protein and the applying of ultrasound constituted the logic AND gate which could implement the precise regulation to apoptosis. This strategy would help reduce nonspecific triggers and side effects. In this system, cationic nanoliposomes were prepared as the carrier for effectively delivering MscL I92L plasmids to tumor cells in vivo. We investigated the apoptosis-promoting effect of this system in different tumor cell lines (HeLa, B16, and 4T1). The results demonstrated that the apoptosis rate was highest in the B16 cell line (the early apoptosis rate was 11.9% and the late apoptosis rate was 59.1%) when the cells were subjected to consistent ultrasound (6 MHz, 15 W) for 30 min. This logic AND-gated sonogene nanosystem is expected to provide a new strategy and development direction for tumor therapy.