A triphenylamine-based colorimetric and fluorescent probe with donor­bridge­acceptor structure for detection of G-quadruplex DNA.

In this Letter, three triphenylamine-based dyes (TPA-1, TPA-2a and TPA-2b) with donor­bridge­acceptor (D­p­A) structure were designed and synthesized for the purpose of G-quadruplexes recognition. In aqueous conditions, the interactions of the dyes with G-quadruplexes were studied with the aim to establish the influence of the geometry of the dyes on their binding and probing properties. Results indicate that TPA-2b displays significant selective colorimetric and fluorescent changes upon binding of G-quadruplex DNA. More importantly, its distinct color change enables visual detection and differentiation of G-quadruplexes from single and duplex DNA structures. CD titration date reveals that TPA-2b could induce and stabilize the formation of G-quadruplex structure. All these remarkable properties of TPA-2b suggest that it should have promising application in the field of G-quadruplexes research.

Targeted deletion of thioesterase superfamily member 1 promotes energy expenditure and protects against obesity and insulin resistance.

Mammalian acyl-CoA thioesterases (Acots) catalyze the hydrolysis of fatty acyl-CoAs to form free fatty acids plus CoA, but their metabolic functions remain undefined. Thioesterase superfamily member 1 (Them1; synonyms Acot11, StarD14, and brown fat inducible thioesterase) is a long-chain fatty acyl-CoA thioesterase that is highly expressed in brown adipose tissue and is regulated by both ambient temperature and food consumption. Here we show that Them1(-/-) mice were resistant to diet-induced obesity despite greater food consumption. Them1(-/-) mice exhibited increased O(2) consumption and heat production, which were accompanied by increased rates of fatty acid oxidation in brown adipose tissue and up-regulation of genes that promote energy expenditure. Them1(-/-) mice were also protected against diet-induced inflammation in white adipose tissue, as well as hepatic steatosis, and demonstrated improved glucose homeostasis. The absence of Them1 expression in vivo and in cell culture led to markedly attenuated diet- or chemically induced endoplasmic reticulum stress responses, providing a mechanism by which Them1 deficiency protects against insulin resistance and lipid deposition. Taken together, these data suggest that Them1 functions to decrease energy consumption and conserve calories. In the setting of nutritional excess, the overproduction of free fatty acids by Them1 provokes insulin resistance that is associated with inflammation and endoplasmic reticulum stress.

Correction: Ultrafast switching to zero field topological spin textures in ferrimagnetic TbFeCo films.

Correction for 'Ultrafast switching to zero field topological spin textures in ferrimagnetic TbFeCo films' by Kaixin Zhu et al., Nanoscale, 2024, 16, 3133-3143, https://doi.org/10.1039/D3NR04529C.

Robust Ferrimagnetism and Ferroelectricity in 2D ɛ-Fe2O3 Semiconductor with Ultrahigh Ordering Temperature.

2D single-phase multiferroic materials with the coexistence of electric and spin polarization offer a tantalizing potential for high-density multilevel data storage. One of the current limitations for application is the scarcity of the materials, especially those combine ferromagnetism and ferroelectricity at high temperatures. Here, robust ferrimagnetism and ferroelectricity in 2D ɛ-Fe2O3 samples with both single-crystalline and polycrystalline form are demonstrated. Interestingly, the polycrystalline nanosheets also exhibit easily switchable ferroelectric polarizations comparable to that of single crystals. The existence of grain boundary does not hinder the switching and retention of ferroelectric polarization. Furthermore, the ɛ-Fe2O3 nanosheets show ferrimagnetic and ferroelectric Curie temperatures up to 800 K, which reaches record highs in 2D single-phase multiferroic materials. This work provides important progress in the exploration of 2D high-temperature single-phase multiferroics for potentially compact high-temperature information nanodevices.

Ultrafast switching to zero field topological spin textures in ferrimagnetic TbFeCo films.

The capability of femtosecond (fs) laser pulses to manipulate topological spin textures on a very short time scale is sparking considerable interest. This article presents the creation of high density zero field topological spin textures by fs laser excitation in ferrimagnetic TbFeCo amorphous films. The topological spin textures are demonstrated to emerge under fs laser pulse excitation through a unique ultrafast nucleation mechanism, rather than thermal effects. Notably, large intrinsic uniaxial anisotropy could substitute the external magnetic field for the creation and stabilization of topological spin textures, which is further verified by the corresponding micromagnetic simulation. The ultrafast switching between topological trivial and nontrivial magnetic states is realized at an optimum magnitude of magnetic field and laser fluence. Our results would broaden the options to generate zero-field topological spin textures from versatile magnetic states and provides a new perspective for ultrafast switching of 0/1 magnetic states in spintronic devices.

CDK6 inhibits de novo lipogenesis in white adipose tissues but not in the liver.

Increased de novo lipogenesis (DNL) in white adipose tissue is associated with insulin sensitivity. Under both Normal-Chow-Diet and High-Fat-Diet, mice expressing a kinase inactive Cyclin-dependent kinase 6 (Cdk6) allele (K43M) display an increase in DNL in visceral white adipose tissues (VAT) as compared to wild type mice (WT), accompanied by markedly increased lipogenic transcriptional factor Carbohydrate-responsive element-binding proteins (CHREBP) and lipogenic enzymes in VAT but not in the liver. Treatment of WT mice under HFD with a CDK6 inhibitor recapitulates the phenotypes observed in K43M mice. Mechanistically, CDK6 phosphorylates AMP-activated protein kinase, leading to phosphorylation and inactivation of acetyl-CoA carboxylase, a key enzyme in DNL. CDK6 also phosphorylates CHREBP thus preventing its entry into the nucleus. Ablation of runt related transcription factor 1 in K43M mature adipocytes reverses most of the phenotypes observed in K43M mice. These results demonstrate a role of CDK6 in DNL and a strategy to alleviate metabolic syndromes.

Down-regulated CK8 expression in human intervertebral disc degeneration.

As an intermediate filament protein, cytokeratin 8 (CK8) exerts multiple cellular functions. Moreover, it has been identified as a marker of notochord cells, which play essential roles in human nucleus pulposus (NP). However, the distribution of CK8 positive cells in human NP and their relationship with intervertebral disc degeneration (IDD) have not been clarified until now. Here, we found the percentage of CK8 positive cells in IDD (25.7±4.14%) was significantly lower than that in normal and scoliosis NP (51.9±9.73% and 47.8±5.51%, respectively, p<0.05). Western blotting and qRT-PCR results confirmed the down-regulation of CK8 expression in IDD on both of protein and mRNA levels. Furthermore, approximately 37.4% of cell clusters were CK8 positive in IDD. Taken together, this is the first study to show a down-regulated CK8 expression and the percentage of CK8 positive cell clusters in IDD based upon multiple lines of evidence. Consequently, CK8 positive cells might be considered as a potential option in the development of cellular treatment strategies for NP repair.

Insights into the hallmarks of human nucleus pulposus cells with particular reference to cell viability, phagocytic potential and long process formation.

OBJECTIVE: As a main cellular component within the disc, nucleus pulposus (NP) cells play important roles in disc physiology. However, little is known on the biologic hallmarks of human NP cells. Therefore, the present study aimed to address the features of human NP cells. METHODS: Human NP samples were collected from normal cadavers, patients with scoliosis and disc degeneration as normal, disease control and degenerative NP, respectively. The NP samples were studied using transmission electron microscopy and TUNEL assay. Pre-digested NP samples were studied using flow cytometry with PI/Annexin V staining. RESULTS: Both control and degenerative human NP consisted of mainly viable cells with a variety of morphology. Both necrosis and apoptosis were noted in human NP as forms of cell death with increased apoptosis in degenerative NP, which was further confirmed by the TUNEL assay. Phagocytic NP cells had the hallmarks of both stationary macrophages with lysosomes and NP cells with the endoplasmic reticulum. Annulus fibrosus cells have similar morphologic characteristics with NP cells in terms of cell nest, phagocytosis and intracellular organs. Moreover, NP cells with long processes existed in degenerative and scoliotic NP rather than normal NP. When cultured in glucose-free medium, NP cells developed long and thin processes. CONCLUSION: Human degenerative NP consists of primarily viable cells. We present direct and in vivo evidence that both human annulus fibrosus and NP cells have phagocytic potential. Moreover, NP cells with long processes exist in both scoliotic and degenerative NP with lack of glucose as one of the possible underlying mechanisms.

Intraoperative analgesic effect of intravertebral lidocaine injection during percutaneous kyphoplasty in the treatment of thoracolumbar compression fractures in elderly patients.

BACKGROUND: In recent years, percutaneous kyphoplasty (PKP) has been increasingly used in clinical settings. OBJECTIVE: In this study, we aimed to determine the analgesic effect of intravertebral lidocaine injections in PKP. METHODS: A total of 60 patients who were treated with PKP were enrolled in this study. Lidocaine hydrochloride was chosen as the medication for the experimental group. Patients were randomly assigned into three groups using a double-blind study design: In group A (20 cases), no drugs were injected into the vertebral body during surgery; group B (20 cases) received intravertebral injection of normal saline; and in group C (20 cases), lidocaine hydrochloride was administered into the vertebral body during surgery. The age of patients, operation time, balloon dilatation pressure, balloon dilatation volume, and amount of bone cement injected were compared across the three groups. A pain visual analog scale (VAS) was used to assess pain suffered by the patients before, during, and 24 hours after the surgery. RESULTS: Age, operation time, balloon dilatation pressure, balloon dilatation volume, and amount of bone cement injected did not differ significantly among the three groups (P> 0.05). The differences in VAS scores 24 hours before and after surgery were not statistically significant (P> 0.05). Group C had lower intraoperative VAS scores than groups A and B, and the difference was statistically significant (P< 0.01). There was no statistically significant difference between group A and group B (P> 0.05). CONCLUSION: Intravertebral injections of lidocaine during PKP can successfully reduce intraoperative pain.

Simulation of ultrafast electron diffraction intensity under coherent acoustic phonons.

Ultrafast electron diffraction has been proven to be a powerful tool for the study of coherent acoustic phonons owing to its high sensitivity to crystal structures. However, this sensitivity leads to complicated behavior of the diffraction intensity, which complicates the analysis process of phonons, especially higher harmonics. Here, we theoretically analyze the effects of photoinduced coherent transverse and longitudinal acoustic phonons on electron diffraction to provide a guide for the exploitation and modulation of coherent phonons. The simulation of the electron diffraction was performed in 30-nm films with different optical penetration depths based on the atomic displacements obtained by solving the wave equation. The simulation results exhibit a complex relationship between the frequencies of the phonons and diffraction signals, which highly depends on the laser penetration depth, sample thickness, and temporal stress distribution. In addition, an intensity decomposition method is proposed to account for the in-phase oscillation and high harmonics caused by inhomogeneous excitation. These results can provide new perspectives and insights for a comprehensive and accurate understanding of the lattice response under coherent phonons.

Efficiently accelerated free electrons by metallic laser accelerator.

Strong electron-photon interactions occurring in a dielectric laser accelerator provide the potential for development of a compact electron accelerator. Theoretically, metallic materials exhibiting notable surface plasmon-field enhancements can possibly generate a high electron acceleration capability. Here, we present a design for metallic material-based on-chip laser-driven accelerators that show a remarkable electron acceleration capability, as demonstrated in ultrafast electron microscopy investigations. Under phase-matching conditions, efficient and continuous acceleration of free electrons on a periodic nanostructure can be achieved. Importantly, an asymmetric spectral structure in which the vast majority of the electrons are in the energy-gain states has been obtained by means of a periodic bowtie-structure accelerator. Due to the presence of surface plasmon enhancement and nonlinear optical effects, the maximum acceleration gradient can reach as high as 0.335 GeV/m. This demonstrates that metallic laser accelerator could provide a way to develop compact accelerators on chip.

Confinement of MnOx@Fe2O3 core-shell catalyst with titania nanotubes: Enhanced N2 selectivity and SO2 tolerance in NH3- SCR process.

Surface interface regulation is an important research content in the field of heterogeneous catalysis. To improve the interface interaction between the active component and matrix, tremendous efforts have been dedicated to tailoring the morphology, size, and structure of composite catalysts. In this work, we report a confinement strategy to synthesize a series of core-shell catalysts loaded with metal oxides on titania nanotubes (TNTs), which were applied to the selective catalytic reduction of NOx with ammonia. Interestingly, the core-shell catalyst with confinement of TNTs exhibited the remarkable activity at low temperature region, N2 selectivity and sulfur tolerance. Benefiting from the superior interfacial confinement characteristic of TNTs and Fe2O3, strong component interactions, the surface acid sites and strong oxidizability of MnOx were properly regulated, thus obtained the outstanding activity, N2 selectivity and provide chemical protection to effectively prevent SO2 poisoning. As far as the reaction mechanism, we found that the adsorption and reactivity of Lewis acid sites were the dominant factors affecting the activity in the NH3-SCR process by in situ DRIFT spectra. In general, our work provides an innovative strategy for constructing an TNTs-enwrapped nanocomposite with nano-confinement and core-shell structure to improve the low temperature SCR process.

Enhancement of lattice dynamics by an azimuthal surface plasmon on the femtosecond time scale in multi-walled carbon nanotubes.

Plasmon-enhanced light-matter interactions have been widely investigated in the past decades. Here, we report surface plasmon-enhanced structural dynamics in multi-walled carbon nanotubes. The optical polarization dependent dynamic properties of multi-walled carbon nanotubes are investigated using ultrafast transmission electron microscopy. Lattice contractions in the femtosecond time regime are observed upon excitation of the azimuthal plasmon by light polarized perpendicular to the tubular axis. The polarization dependence of the plasmon near field was examined using photon-induced near-field electron microscopy. The lattice changes resulting from the azimuthal plasmon enhance ultrafast alterations in both localized evanescent fields and the collective charge excitation, which play critical roles governing the light-matter interaction. These results suggest that the ultrafast responses of lattice degrees of freedom in nanomaterials could be essential for understanding the mechanism of surface plasmon enhanced effects.

Therapeutic Effect of Resection, Prosthetic Replacement and Open Reduction and Internal Fixation for the Treatment of Mason Type III Radial Head Fracture.

Aim of the Study: Mason type III radial head fractures are a source of concern due to the severe injury and poor recovery. At present, radial head resection, open reduction and internal fixation (ORIF), and prosthetic replacement are three common treatment methods for these fractures. The clinical efficacy and postoperative complications are controversial, which makes it difficult for physicians to determine the most appropriate regimen. Herein, this present prospective, non-randomized, parallel-controlled study was conducted to compare the therapeutic effects and identify the most effective treatment method for Mason type III radial head fracture. Materials and Methods: We assessed patients with Mason type III radial head fracture treated with resection, prosthetic replacement, and ORIF to compare preoperative and postoperative pain condition, elbow joint function, curative effect, and complication rate. A visual analog scale was used to score pain. The elbow joint function was observed using the Broberg-Morrey elbow joint score. Results: No significant differences were found in patient demographics among the resection, prosthetic replacement, and ORIF groups. The prosthetic replacement and ORIF procedures were more complex and had higher technical requirements. Prosthetic replacement and ORIF enabled higher elbow joint scores and lower pain scores than resection. Excellent and good ratings were highest and complication rates were lowest in the prosthetic replacement group, followed by the ORIF group. Conclusion: Our results showed that prosthetic replacement is more effective than ORIF and radial head resection in relieving pain, functional recovery and reducing complications in the treatment of Mason type III radial head fractures.

The flavoheme reductase Ncb5or protects cells against endoplasmic reticulum stress-induced lipotoxicity.

NCB5OR is a novel flavoheme reductase with a cytochrome b5-like domain at the N-terminus and a cytochrome b5 reductase-like domain at the C terminus. Ncb5or knock-out mice develop insulin deficient diabetes and loss of white adipose tissue. Ncb5or(-/-) mice have impairment of Delta9 fatty acid desaturation with elevated ratios of palmitate to palmitoleate and stearate to oleate. In this study we assess the role of the endoplasmic reticulum (ER) stress response in mediating lipotoxicity in Ncb5or(-/-) mice. The ER stress response was assessed by induction of BiP, ATF3, ATF6, XBP-1, and C/EBP homologous protein (CHOP). Exposure to palmitate, but not oleate or mixtures of oleate and palmitate induced these markers of ER stress to a much greater extent in Ncb5or(-/-) hepatocytes than in wild-type cells. In contrast, Ncb5or(-/-) and Ncb5or(+/+) hepatocytes were equally sensitive to ER stress imposed by increasing concentrations of tunicamycin. In order to assess the role of ER stress in vivo, we prepared mice that lack both NCB5OR and CHOP, a proapoptotic transcription factor important in the ER stress response. Onset of hyperglycemia in the Chop(-/-);Ncb5or(-/-) mice was delayed two weeks beyond that observed in Chop(+/+);Ncb5or(-/-) mice. Taken together these results suggest that ER stress plays a critical role in palmitate-induced lipotoxicity both in vitro and in vivo.

Ultrafast lattice and electronic dynamics in single-walled carbon nanotubes.

Understanding the photoinduced ultrafast structural transitions and electronic dynamics in single-walled carbon nanotubes (SWCNTs) is important for the development of SWCNT-based optoelectronic devices. In this study, we conducted femtosecond-resolved electron diffraction and electron energy-loss spectroscopy (EELS) measurements on SWCNTs using ultrafast transmission electron microscopy. The experimental results demonstrated that dominant time constants of the dynamic processes were ∼1.4 ps for electron-driven lattice expansion, ∼17.4 ps for thermal phonon-driven lattice expansion associated with electron-phonon coupling. The time-resolved EELS measurements clearly revealed a notable red shift of plasmon peaks by ∼100 meV upon femtosecond laser excitation. Different features of charge carrier excitation and relaxation were carefully discussed in correlation with the lattice dynamics and photoinduced absorption signals of SWCNTs. Our results provide a comprehensive understanding of the ultrafast dynamics in SWCNTs and powerful techniques to characterize the dynamics of low-dimensional structures.

N'-(4-Hydr-oxy-3-methoxy-benzyl-idene)acetohydrazide monohydrate.

In the title compound, C(10)H(12)N(2)O(3)·H(2)O, the Schiff base mol-ecule is approximately planar [within 0.189 (1) Å]. The inter-planar angle between the benzene and acetohydrazide planes is 8.50 (10)°. In the crystal, mol-ecules are linked into a three-dimensional network by strong and weak O-H⋯O and strong N-H⋯O hydrogen bonds. The hydr-oxy H atom deviates from the 4-hydr-oxy-3-methoxy-phenyl mean plane by 0.319 (2) Å, probably due to the involvement of this H atom in the O-H⋯O hydrogen bond. The weak O-H⋯O hydrogen bond is involved in a bifurcated hydrogen bond with R(1) (2)(4) motif. A weak C-H⋯π inter-action is also present.

N'-(3,4-Dihydroxy-benzyl-idene)acetohydrazide.

In the title compound, C(9)H(10)N(2)O(3), the Schiff base mol-ecule is approximately planar, the dihedral angle between the benzene ring and the acetohydrazide group (r.m.s. deviation = 0.034 Å) being 8.81 (7)°. An intra-molecular O-H⋯O hydrogen bond is observed. In the crystal, mol-ecules are linked into a three-dimensional network by O-H⋯O, N-H⋯O and C-H⋯O hydrogen bonds.

(E)-Methyl N'-(2-hydr-oxy-3-methoxy-benzyl-idene)hydrazinecarboxyl-ate.

The title compound, C(10)H(12)N(2)O(4), adopts a trans configuration with respect to the C=N double bond. The non-H atoms of the mol-ecule are essentially coplanar, with a maximum deviation of 0.015 (2) Å. An intra-molecular O-H⋯N inter-action is observed. In the crystal structure, the mol-ecules are linked into a two-dimensional network parallel to the ac plane by N-H⋯O hydrogen bonds involving the meth-oxy O atom and by two C-H⋯O hydrogen bonds involving the carbonyl O atom. In addition, an intermolecular C-H⋯π inter-action is observed.

Facile synthesis of highly ordered mesoporous Fe3O4 with ultrasensitive detection of dopamine.

Dopamine (DA) detection is significant for the prevention of unfavorable neuronal illness. However, the detection of DA with low concentration still face tremendous challenges. In this study, highly ordered mesoporous Fe3O4 materials were synthesized as a biosensor by using mesoporous silica KIT-6 with different aging temperature as hard template. The ordered mesoporous Fe3O4 with high surface area modified glassy carbon electrode shows the high sensitivity for detecting DA. Fe3O4-40 mesoporous material modified electrode has the highest catalytic activity to DA with a sensitivity of 0.053 nA nM-1 and a detection limit of 0.8 nM (S/N = 3). The results indicating that the mesoporous Fe3O4 material modified electrode exhibits high sensitivity to determine DA at low levels, which can be used for DA real-time monitoring in neutral biological media.