Friends not Foes: Exfoliation of Non-van der Waals Materials.

ConspectusTwo-dimensional materials have been a focus of study for decades, resulting in the development of a library of nanosheets made by a variety of methods. However, many of these atomically thin materials are exfoliated from van der Waals (vdW) compounds, which inherently have weaker bonding between layers in the bulk crystal. Even though there are diverse properties and structures within this class of compounds, it would behoove the community to look beyond these compounds toward the exfoliation of non-vdW compounds as well. A particular class of non-vdW compounds that may be amenable to exfoliation are the ionically bonded layered materials, which are structurally similar to vdW compounds but have alkali ions intercalated between the layers. Although initially they may have been more difficult to exfoliate due to a lack of methodology beyond mechanical exfoliation, many synthesis techniques have been developed that have been used successfully in exfoliating non-vdW materials. In fact, as we will show, in some cases it has even proven to be advantageous to start the exfoliation from a non-vdW compound.The method we will highlight here is chemical exfoliation, which has developed significantly and is better understood mechanistically compared to when it was first conceived. Encompassing many methods, such as acid/base reactions, solvent reactions, and oxidative extractions, chemical exfoliation can be tailored to the delamination of non-vdW materials, which opens up many more possibilities of compounds to study. In addition, beginning with intercalated analogues of vdW materials can even lead to more consistent and higher quality results, overcoming some challenges associated with chemical exfoliation in general. To exemplify this, we will discuss our group's work on the synthesis of a 1T'-WS2 monolayer ink. By starting with K0.5WS2, the exfoliated 1T'-WS2 nanosheets obtained were larger and more uniform in thickness than those from previous syntheses beginning with vdW materials. The crystallinity of the nanosheets was high enough that films made from this ink were superconducting. We will also show how soft chemical methods can be used to make new phases from existing compounds, such as HxCrS2 from NaCrS2. This material was found to have alternating amorphous and crystalline layers. Its biphasic structure improved the material's performance as a battery electrode, enabling reversible Cr redox and faster Na-ion diffusion. From these and other examples, we will see how chemical exfoliation of non-vdW materials compares to other methods, as well as how this technique can be further extended to known compounds that can be deintercalated electrochemically and to quasi-one-dimensional crystals.

HTR3A Promotes Non-small Cell Lung Cancer Through the FOXH1/Wnt3A Signaling Pathway.

5-Hydroxytryptamine receptors (5-HTRs) are strongly correlated with tumor progression in various types of cancer. Despite this, the underlying mechanisms responsible for the role of 5-HTRs in non-small cell lung cancer (NSCLC) remains unclear. This study aimed to investigate the relationship between 5-hydroxytryptamine receptor 3A (HTR3A) and NSCLC development. Our findings indicated a higher distribution of HTR3A expression in NSCLC tissues when compared with normal tissues, where patients with high HTR3A levels demonstrated shorter overall survival times. In vitro analyses revealed that overexpression of HTR3A facilitated the proliferation and migration of NSCLC cell lines (A549 and NCI-H3255). Similarly, a notable acceleration of tumor growth and enhanced pulmonary tumorigenic potential were observed in HTR3A-overexpressing tumor-bearing mice. Mechanistically, upregulation of Forkhead Box H1 (FOXH1) by HTR3A led to the activation of Wnt3A/ß-catenin signaling pathways, thereby promoting the development of NSCLC. Our report thus highlights the significance of the HTR3A/FOXH1 axis during tumor progression in NSCLC, proposing HTR3A as a possible diagnostic indicator and candidate target for clinical therapy.

Chemical exfoliation of 1-dimensional antiferromagnetic nanoribbons from a non-van der Waals material.

As the demand for increasingly varied types of 1-dimensional (1D) materials grows, there is a greater need for new methods to synthesize these types of materials in a simple and scalable way. Chemical exfoliation is commonly used to make 2-dimensional (2D) materials, often in a way that is both straightforward and suitable for making larger quantities, yet this method has thus far been underutilized for synthesizing 1D materials. In the few instances when chemical exfoliation has been used to make 1D materials, the starting compound has been a van der Waals material, thus excluding any structures without these weak bonds inherently present. We demonstrate here that ionically bonded crystals can also be chemically exfoliated to 1D structures by choosing KFeS2 as an example. Using chemical exfoliation, antiferromagnetic 1D nanoribbons can be yielded in a single step. The nanoribbons are crystalline and closely resemble the parent compound both in structure and in intrinsic antiferromagnetism. The facile chemical exfoliation of an ionically bonded crystal shown in this work opens up opportunities for the synthesis of both magnetic and non-magnetic 1D nanomaterials from a greater variety of starting structures.

CpG oligodeoxynucleotides inhibit tumor growth and reverse the immunosuppression caused by the therapy with 5-fluorouracil in murine hepatoma.

AIM: To investigate the effect of CpG-containing oligodeoxynucleotides (CpG ODN) alone or in combination with the chemotherapeutic agent 5-fluorouracil (5-FU) on tumor growth and whether CpG ODN can reverse the immunosuppression caused by the chemotherapy with 5-FU in murine hepatoma model. METHODS: Hepatoma model was established by subcutaneous inoculation with hepatoma-22 (H(22)) cells into the right flank of BALB/c mice. Mice with tumor were treated by peritumoral injection of CpG ODN alone or in combination with subcutaneous injection of 5-FU. Tumor size was quantified regularly. Serum levels of IL-12 and IFN-gamma in mice were assayed by enzyme-linked immunosorbent assay (ELISA). The lytic capacity of splenic NK cells was tested by lactate dehydrogenase release assay. RESULTS: Peritumoral injection of CpG ODN alone or in combination with subcutaneous injection of 5-FU, and the treatment with 5-FU alone all led to significant inhibition of hepatoma growth. The mean tumor volumes fell by 46.66% in mice injected with CpG ODN, 68.34% in the 5-FU treated mice, and 70.23% in mice treated with the combination of CpG ODN and 5-FU than in controls. There was no significant difference in tumor size between 5-FU-treated mice and mice treated with the combination of 5-FU and CpG ODN (P>0.05). The serum levels of IL-12 and IFN-gamma of mice treated with CpG ODN alone (IL-12: 464.50+/-24.37 pg/mL; IFN-gamma: 134.20+/-25.76 pg/mL) or with the co-administration of CpG ODN and 5-FU (IL-12: 335.83+/-28.74 pg/mL; IFN-gamma: 111.00+/-5.33 pg/mL) were significantly higher than that of controls (IL-12: 237.50+/-45.31 pg/mL; IFN-gamma: 56.75+/-8.22 pg/mL). The production of IL-12 and IFN-gamma was suppressed moderately in 5-FU-treated mice (IL-12: 166.67+/-53.22 pg/mL; 53.33+/-16.98 pg/mL) compared to control mice (P>0.05), whereas the combination of CpG ODN and 5-FU significantly increased the serum levels of IL-12 and IFN-gamma compared to 5-FU alone (P<0.05). The NK cell killing activity in CpG ODN-treated mice (44.04+/-1.38%) or the mice treated with CpG ODN combined with 5-FU (30.67+/-1.28%) was significantly potentiated compared to controls (19.22+/-0.95%, P<0.05). The co-administration of CpG ODN and 5-FU also significantly enhanced the lytic activity of NK cells when compared with the treatment with 5-FU alone (12.03+/-1.42%, P<0.05). CONCLUSION: The present data suggests that CpG ODN used as single therapeutic agent triggers anti-tumor immune response to inhibit the growth of implanted hepatoma and reverses the immunosuppression caused by the chemotherapy with 5-FU.

Effect of chronic cigarette smoking on large-conductance calcium-activated potassium channel and Kv1.5 expression in bronchial smooth muscle cells of rats.

To investigate the role of potassium channels in the pathogenesis of airway hyperresponsiveness induced by cigarette smoking, the alteration in expression of large-conductance calcium-activated potassium channel (BKca) and voltage-dependent delayed rectifier potassium channel (Kv1.5) in bronchial smooth muscle cells were investigated in chronic cigarette smoking rats. Airway responsiveness was determined, hematoxylin and eosin staining, immuno-histochemistry, in-situ hybridization and western blot techniques were used. The results showed: (1) Chronic cigarette smoking down-regulated the protein synthesis and mRNA expression of BKca and Kv1.5 in bronchial and bronchiolar smooth muscles. (2) BKca decreased more markedly than Kv1.5 in bronchi, but there was no difference between them in bronchioli. (3) No changes in the expression of these two potassium channel proteins were found in extracted cell membrane protein from lung tissue. The results suggest that chronic cigarette smoking can down-regulate the levels of BKca and Kv1.5 in rat bronchial smooth muscle cells in vivo, which might contribute to the mechanism of airway hyperresponsiveness induced by cigarette smoking.

Effects of Zuogui Wan on neurocyte apoptosis and down-regulation of TGF-beta1 expression in nuclei of arcuate hypothalamus of monosodium glutamate -liver regeneration rats.

AIM: To inquire into the effects and mechanism of Zuogui Wan (Pills for Kidney Yin) on neurocyte apoptosis in nuclei of arcuate hypothalamus (ARN) of monosodium glutamate (MSG)-liver regeneration rats, and the mechanism of liver regeneration by using optic microscope, electron microscope and in situ end labeling technology to adjust nerve-endocrine-immunity network. METHODS: Neurocyte apoptosis in ARN of the experiment rats was observed by using optic microscope, electron microscope and in situ end labeling technology. Expression of TGF-beta1 in ARN was observed by using immunohistochemistry method. RESULTS: The expression of TGF-beta1 in rats of model group was increased with the increase of ARN neurocyte apoptosis index (AI) (t = 8.3097, 12.9884, P<0.01). As compared with the rats of model group, the expression of TGF-beta1 in rats of Zuogui Wan treatment group was decreased with the significant decrease of ARN neurocyte apoptosis (t = 4.5624, 11.1420, P<0.01). CONCLUSION: Brain neurocyte calcium ion overexertion and TGF-beta1 protein participate in the adjustment and control of ARN neurocyte apoptosis in MSG-liver regeneration-rats. Zuogui Wan can prevent ARN neurocyte apoptosis of MSG-liver regeneration in rats by down-regulating the expression of TGF-beta1, and influence liver regeneration through adjusting nerve-endocrine-immune network.

The comparative study on ultrastructure and immunohistochemistry in AFP negative and positive hepatocellular carcinoma.

SUMMARY: To comparatively investigate ultrastructural characteristics and expressions of AFP (alpha-fetoprotein) and Tn (Thomsen-Friedenreich-related antigen) protein in AFP negative (AFP-) and AFP positive (AFP+) primary hepatocellular carcinoma. Fourty-three cases of AFP- and AFP+ hepatocellular carcinoma (HCC) tissues and five cases of normal liver tissues were divided into three groups: control group (normal liver tissue, n=5); AFP+ HCC group (the serum AFP level was higher than 10 ng/ml, n = 22); AFP- HCC group (the serum AFP level was lower than 10 ng/ml, n=21). The ultrastructural morphology was studied by transmission electron microscopy, the expressions of AFP and Tn protein were detected by immunohistochemistry and cell image analysis. 1. The immunohistochemical study showed that (1) the expression intensity and positive rate of Tn protein in AFP- HCC group were markedly higher than that in AFP+ HCC group (P<0.01); (2) The expression intensity of AFP in AFP- HCC group was lower than that in AFP+ HCC group (P<0.01). 2. The transmission electron microscopy demonstrated that some AFP- HCC cells linked closely with each other, others dispersed loosely just as cultured cells, the remarkable morphologic features in AFP- HCC cells were simple organelles, but they were abundant in the free polyribosomes. In AFP+ HCC group, all the HCC cells linked closely together and were rich organelles in their cytoplasm, especially the rough endoplasmic reticula. In addition, mitochondria and Golgi complex were obviously observed. (1) The AFP and Tn protein had discrepancy distribution in AFP- and AFP+ HCC tissues, Tn protein may be one of the early diagnostic indicators in AFP- HCC; (2) The synthetic locations of the AFP and Tn protein were different in hepatocarcinoma cells by ultrastructural observation.