Single-atom catalysts not only maximize metal atom efficiency, they also display properties that are considerably different to their more conventional nanoparticle equivalents, making them a ...promising family of materials to investigate. Herein we developed a general host-guest strategy to fabricate various metal single-atom catalysts on nitrogen-doped carbon (M
/CN, M = Pt, Ir, Pd, Ru, Mo, Ga, Cu, Ni, Mn). The iridium variant Ir
/CN electrocatalyses the formic acid oxidation reaction with a mass activity of 12.9 Formula: see text whereas an Ir/C nanoparticle catalyst is almost inert (~4.8 × 10
Formula: see text). The activity of Ir
/CN is also 16 and 19 times greater than those of Pd/C and Pt/C, respectively. Furthermore, Ir
/CN displays high tolerance to CO poisoning. First-principle density functional theory reveals that the properties of Ir
/CN stem from the spatial isolation of iridium sites and from the modified electronic structure of iridium with respect to a conventional nanoparticle catalyst.
Metal isolated single atomic sites catalysts have attracted intensive attention in recent years owing to their maximized atom utilization and unique structure. Despite the success of single atom ...catalyst synthesis, directly anchoring metal single atoms on three-dimensional (3D) macro support, which is promising to achieve the heterogenization of homogeneous catalysis, remains a challenge and a blank in this field. Herein, we successfully fabricate metal single atoms (Pd, Pt, Ru, Au) on porous carbon nitride/reduced graphene oxide (C
3
N
4
/rGO) foam as highly efficient catalysts with convenient recyclability. C
3
N
4
/rGO foam features two-dimensional microstructures with abundant N chelating sites for the stabilization of metal single atoms and vertically-aligned hierarchical mesostructure that benefits the mass diffusion. The obtained Pd
1
/C
3
N
4
/rGO monolith catalyst exhibits much enhanced activity over its nanoparticle counterpart for Suzuki-Miyaura reaction. Moreover, the Pd
1
/C
3
N
4
/rGO monolith catalyst can be readily assembled in a flow reactor to achieve the highly efficient continuous production of 4-nitro-1,1′-biphenyl through Suzuki-Miyaura coupling.
Aberrant expression of adipogenic regulatory factors (ADIRF) in tumor cells is critical for tumor growth and metastasis. N6-methyladenosine (m6A) modifications have an important role in a variety of ...biological activities. Our study aimed to investigate the role of ADIRF in adenocarcinoma and to elucidate the regulatory role of m6A signaling on ADIRF. Differential expression of genes in tumor and normal tissues was analyzed using the LUAD dataset (GSE1987). The Kaplan-Meier method and receiver operating characteristic (ROC) curve analysis were performed to evaluate the prognostic and diagnostic value of ADIRF in LUAD. Loss-of-function or gain-of-function experiments were performed to study the effect of ADIRF on LUAD growth in vitro. The molecular mechanism of action of ADIRF in LUAD was confirmed using a dual-luciferase reporter system and MeRIP-qPCR. We identified a loss of ADIRF expression in LUAD tissues and cells. Furthermore, the restoration of ADIRF levels attenuated LUAD cell growth and metastasis in vitro. Mechanistically, an m6A “eraser,” α-ketoglutarate-dependent dioxygenase alkB homolog 5 (ALKBH5), eliminated the ADIRF m6A modification motif and further blocked the binding of the YTH domain-containing 2 (YTHDC2)-binding protein to ADIRF. At the molecular level, ALKBH5 enrichment increased ADIRF mRNA levels and prevented the attenuation of ADIRF mRNA by YTHDC2. The effects of ALKBH5 overexpression could also extend to the inhibition of LUAD cell proliferation and metastasis. This study linked ADIRF with the m6A modifying regulators ALKBH5 and YTHDC2, providing a promising molecular intervention for LUAD and deepening the understanding of LUAD mechanisms.
Background
Hitherto, no study has evaluated postoperative pain in patients with non-small cell lung cancer (NSCLC) treated with video-assisted mini-thoracotomy (VAMT). In this study, we aimed to ...assess postoperative pain related to the width of the metal rib spreader in patients who underwent lobectomy using VAMT.
Methods
We retrospectively analysed the data of 94 consecutive patients with NSCLC who underwent lobectomy using VAMT at our institution between March 2019 and May 2022. We divided the patients into groups according to the width ratio of the rib spreader to that of a single intercostal space. Patients with width ratios ≤ 2.5 times were assigned to group A, and those with width ratios > 2.5 times were assigned to group B. Pre-, intra-, and postoperative data were collected and reviewed.
Results
We successfully performed VAMT in 94 patients with NSCLC. Forty-five patients were in group A, and 49 were in group B. There were no intraoperative mortalities, although one patient, due to respiratory failure, experienced 30-day mortality. There were no significant differences between the two groups in terms of the blood loss volume, operative time, drainage time, postoperative complications, length of hospital stay, or number of lymph node stations explored and retrieved. The drainage volumes (Day 1–Day 3) were higher in group B than in group A (
P
< 0.05). The postoperative visual analogue scale (VAS) pain scores were significantly lower in Group A than in Group B at 12, 24, and 48 h (
P
< 0.05), although there was no significant difference in the VAS scores between the two groups at 72 h and 1 week postoperatively (
P
> 0.05).
Conclusion
The smaller the width of the metal rib spreader used in surgery, the less pain experienced by the patient and the faster the recovery. Multicentre, randomised, controlled trials should be conducted in the future.
Efficient electroreduction of CO
2
into CO and other chemicals turns greenhouse gases into fuels and value-added chemicals, holding great promise for a closed carbon cycle and the alleviation of ...climate changes. However, there are still challenges in the large-scale application of CO
2
electroreduction due to the sluggish kinetics. Herein we develop a self-assembly strategy to synthesize a highly efficient CO
2
reduction electrocatalyst with atomically dispersed Ni-N
4
active centers anchored on polymer-derived mesh-like N-doped carbon nanofibers (Ni-N
4
/NC). The Ni-N
4
/NC exhibits high selectivity for CO
2
reduction reaction with CO Faradaic efficiency (CO FE) above 90% over a wide potential range from −0.6 to −1.0 V vs. RHE. The catalyst reaches a maximum CO FE up to 98.4% at −0.8 V with a TOF of 1.28 × 10
5
h
−1
and Tafel slope of 113 mV·dec
−1
. The catalyst also exhibits remarkable stability, with little change in current density and CO FE over a 10-hour durability test at −0.8 V vs. RHE. This method provides a new route for the synthesis of highly efficient CO
2
reduction electrocatalyst.
Previous studies have reported that microbubbles bearing targeting ligands to molecular markers of angiogenesis can be successfully detected by ultrasound imaging in various animal models of solid ...cancer. In the present study, we sought to investigate the activity of microbubbles targeted to vascular endothelial growth factor receptor 2 (VEGFR2) in an orthotopic model of renal cell carcinoma (RCC). Microbubbles conjugated to an anti-VEGFR2 antibody (MBV) were compared with microbubbles conjugated to an isotype control antibody (MBC) or naked microbubbles (MBN). An orthotopic mouse model of human RCC was established by surgically implanting an established tumor within the renal capsule in mice. Tumor growth and blood flow were verified by B-mode and color Doppler ultrasound imaging. VEGFR2 expression within the tumor and renal parenchyma was detected by immunohistochemistry. The duration of contrast enhancement of MBV was much longer than those of MBN and MBC when assessed over 10 min. The baseline-subtracted contrast intensity within the tumor was higher for MBV than for MBC and MBN (p < 0.01). Additionally, the contrast intensity for MBV was significantly higher in the tumor region than in normal parenchyma (p < 0.01). Microbubbles targeting VEGFR2 exhibit suitable properties for imaging angiogenesis in orthotopic models of renal cell carcinoma, with potential applications in life science research and clinical medicine.
Single-atom-site catalysts (SASCs) featuring maximized atom utilization and isolated active sites have progressed tremendously in recent years as a highly prosperous branch of catalysis research. ...Varieties of SASCs have been developed that show excellent performance in many catalytic applications. The major goal of SASC research is to establish feasible synthetic strategies for the preparation of high-performance catalysts, to achieve an in-depth understanding of the active-site structures and catalytic mechanisms, and to develop practical catalysts with industrial value. This Perspective describes the up-to-date development of SASCs and related catalysts, such as dual-atom-site catalysts (DASCs) and nano-single-atom-site catalysts (NSASCs), analyzes the current challenges encountered by these catalysts for industrial applications, and proposes their possible future development path.
There has been a great interest in fermentative hydrogen production during recent decades. However, the low H2 yield associated with fermentative hydrogen production process continues to hinder its ...industrial application. It is delectable that a maximum 3.9 mol H2 per mol glucose was obtained in fed-batch fermentation mode with a butyric acid over-producing Clostridium tyrobutyricum mutant, which to our knowledge is the highest H2 yield ever got in the fermentation process with Clostridium sp. This study aimed to better understand the change of flux profile within the whole metabolic network and to conduct the metabolic flux analysis of fermentative hydrogen production. For the first time, we constructed a metabolic flux model for the anaerobic glucose metabolism of C. tyrobutyricum ATCC 25755, and revealed the internal mechanism responsible for the redistribution of the carbon flux in the mutant strain in comparison with the wide-type. The MFA methodology was used to study the fractional flux response to variations in operational pH, and revealed that pH was a significant operational parameter effecting on the fermentative hydrogen production process. Furthermore, the presence of NADH-ferredoxin oxidoreductase activity in this anaerobe was demonstrated. By measuring the activities of related enzymes in the biosynthesis pathway of hydrogen, we thus concluded that the increased specific activities of both NFOR and hydrogen-catalyzing enzyme (hydrogenase) would be attributed to the hydrogen over-producing.
► We constructed a metabolic flux model for H2 production of Clostridium tyrobutyricum. ► We revealed the redistribution of the carbon flux in mutant and wide-type strain. ► The operational pH was proved to be a key parameter for H2 production. ► The presence of a NFOR in C. tyrobutyricum was demonstrated. ► The high activities of NFOR and hydrogenase were benefit for H2 production.
Single-atom site catalysts (SASCs) are characterized with atomically dispersed isolated metal active sites and theoretically 100% metal dispersion. Supports with high specific surface area are ...crucial for the fabrication of highly efficient SASCs with maximized metal dispersion. The high specific surface area supports provide anchoring sites that stabilize the monodispersed active metal atoms. The metal atoms and their coordination environment jointly constitute the metal single-atom sites, which represent the active sites of SASCs. The selection of suitable supports is one of the key factors that determine the structures and properties of SASCs. In this perspective, we introduce various types of SASCs based on high specific surface area supports from 0-dimension to 3-dimension with different sorts of active sites and coordination environments. In particular, we select the most representative high specific surface supports in each dimension and introduce the corresponding SASCs and how different supports cooperate with single metal atoms to achieve efficient catalysis. We summarize the current developments, and also present future opportunities and challenges of SASCs, aiming to provide an instructive perspective of the SASCs based on high specific surface area supports.
Single-atom site catalysts (SASCs) are characterized with atomically dispersed isolated metal active sites and theoretically 100% metal dispersion.
CRISPR is reshaping biosensing technology due to its programmability, sensitivity, and specificity. Most current CRISPR-based biosensors are developed based on Cas12 and Cas13, while the biosensing ...potentials of the newly discovered Cas14 have not been fully elucidated yet. Herein, a fluorometric biosensor named HARRY (highly sensitive aptamer-regulated Cas14 R-loop for bioanalysis) was developed. The diblock ssDNA is designed to contain the activator sequence of Cas14 and the aptamer sequence of specific targets. In the absence of targets, the ssDNA activates Cas14a, then the Cas14a trans-cleavages the fluorescent reporter, causing fluorescence enhancement. In the presence of the targets, ssDNA-target assembly is formed via aptamer interaction, resulting in the inhibition of Cas14a activation. HARRY can detect ATP, Cd2+, histamine, aflatoxin B1, and thrombin with detection limits at the low-nanomolar level, which shows improvement compared with Cas12a-based aptasensors in sensitivity and versatility. We reasoned that the improvement is derived from the ssDNA specificity of Cas14a and found that the detection limit of HARRY is correlated to the binding affinities of aptamers. This study unlocks the potential of Cas14a in versatile aptasensing, which may inspire the development of CRISPR-based biosensors from the Cas14a branch.
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•A fluorometric aptasensor based on CRISPR/Cas14 was developed.•This Cas14-based aptasensor is sensitive in the detection of diverse targets.•Cas14 is more sensitive than Cas12 in aptasensing.
