Sorbitol Destroyed Intestinal Microfold Cells (M Cells) Development through Inhibition of PDE4-Mediated RANKL Expression

Objective

Microfold cells (M cells) are specific intestinal epithelial cells for monitoring and transcytosis of antigens, microorganisms, and pathogens in the intestine. However, the mechanism for M-cell development remained elusive.

Materials and Methods

Real-time polymerase chain reaction, immunofluorescence, and western blotting were performed to analyze the effect of sorbitol-regulated M-cell differentiation in vivo and in vitro, and luciferase and chromatin Immunoprecipitation were used to reveal the mechanism through which sorbitol-modulated M-cell differentiation.

Results

Herein, in comparison to the mannitol group (control group), we found that intestinal M-cell development was inhibited in response to sorbitol treatment as evidenced by impaired enteroids accompanying with decreased early differentiation marker Annexin 5, Marcksl1, Spib, sox8, and mature M-cell marker glycoprotein 2 expression, which was attributed to downregulation of receptor activator of nuclear factor kappa-В ligand (RANKL) expression in vivo and in vitro. Mechanically, in the M-cell model, sorbitol stimulation caused a significant upregulation of phosphodiesterase 4 (PDE4) phosphorylation, leading to decreased protein kinase A (PKA)/cAMP-response element binding protein (CREB) activation, which further resulted in CREB retention in cytosolic and attenuated CREB binds to RANKL promoter to inhibit RANKL expression. Interestingly, endogenous PKA interacted with CREB, and this interaction was destroyed by sorbitol stimulation. Most importantly, inhibition of PDE4 by dipyridamole could rescue the inhibitory effect of sorbitol on intestinal enteroids and M-cell differentiation and mature in vivo and in vitro.

Conclusion

These findings suggested that sorbitol suppressed intestinal enteroids and M-cell differentiation and matured through PDE4-mediated RANKL expression; targeting to inhibit PDE4 was sufficient to induce M-cell development.

Highly Stretchable and Multimodal MXene/CNTs/TPU Flexible Resistive Sensor with Hierarchical Structure Inspired by Annual Ring for Hand Rehabilitation

With the advent of the intelligent age and people's higher pursuit of health, wearable sensors with functions of health monitoring and assisting physical rehabilitation are increasingly favored by consumers. Wherein, highly stretchable flexible sensors show promising potential, but the unstable conductivity under large strains remains a great challenge to develop flexible wearable sensors with both a wide work range and strain insensitivity. Based on this, a MXene/CNTs/TPU flexible resistive sensor (MCT/FRS) with hierarchical structure inspired by the annual ring was proposed. Benefiting from the bioinspired structure with tightly warped inner layers and deformable spring structure outside, the MCT/FRSs enable stable sensing over a wide working range of up to 700% under the stretching mode, as well as superior durability (7500 cycles). It also possessed linear and adjustable piezoresistive properties under the compression mode. Finally, the sensor was not only successfully employed for monitoring various human movements but also was utilized to assist hand rehabilitation in patients with Guillain-Barré syndrome in both stretching and compression modes. This work provides promising and attractive solutions for flexible wearable devices and intelligent medical care.

[Co-exposure of carbon black and cadmium induces autophagy and inflammation in human bronchial epithelial cells via PERK pathway]

Objective: To investigate the effects of carbon black and cadmium (Cd) combined exposure on autophagy and inflammatory response mediated by protein kinase R-like endoplasmic reticulum kinase (PERK) pathway in human bronchial epithelial (16HBE) cells. Methods: In January 2022, human bronchial epithelial (16HBE) cells were resuscitated and cultured. Carbon black nanoparticles (CBNPs) were oxidized to adsorb Cd ions to construct "CBNPs-Cd" complexes. CCK-8 assay was used to detect the effects of different concentrations and time combinations of CBNPs and Cd on the viability of 16HBE cells. The subsequent dose groups were exposed to 2 μg/ml Cd, 100 μg/ml CBNPs, 100 μg/ml CBNPs+2 μg/ml Cd for 24 h. The number of autophagosomes and autolysosomes was detected by transmission electron microscopy. Western blotting was used to detect the protein expressions of PERK, eukaryotic initiation factor 2α (eIf2α), activating transcription factor 4 (ATF4), sequestosome 1 (SQSTM1/P62), and microtubule-associated protein 1 light chain 3 (LC3). After PERK gene was silenced by siRNA technology, the changes of autophagy marker proteins P62 and LC3 were detected, and the expressions of inflammatory factors interleukin-6 (IL6) and interleukin-8 (IL8) were detected by fluorescence quantitative PCR technique. One-way ANOVA analysis was used to compare three groups or more. LSD test was used for comparison between two groups. Factorial analysis was used for multivariate component analysis. Results: There was no significant change in cell viability of 16HBE after 24 h exposure to CBNPs and Cd alone or combined (P>0.05). Compared with the control group, the expressions of P62 and LC3 in 16HBE cells were significantly increased in the CBNPs and Cd alone/combined exposure group (P<0.05), and the number of autophagosomes and autophagolysosomes in the combined exposure group was increased compared with other groups. Compared with the control group, CBNPs and Cd alone exposure group had no significant effects on p-PERK/PERK and p-eIf2α/eIf2α protein expression (P>0.05). However, the protein expressions of p-PERK/PERK and p-eIf2α/eIf2α and ATF4 were all increased in the combined exposure group (P<0.05), and the levels of IL6 and IL8 in 16HBE cells in the combined exposure group of CBNPs and Cd were significantly higher than those in the control group (P<0.05). The levels of LC3 protein, IL6 and IL8 were decreased in the CBNPs-Cd combined exposure group after knockdown of PERK gene (P<0.05). The results of factorial analysis showed that exposure to CBNPs and Cd had significant effects on the expression of P62, LC3 and IL6 (P<0.05), but the interaction between the two chemicals had no statistical significance (P>0.05) . Conclusion: CBNPs-Cd combined exposure may inhibit autophagy and increase inflammation in human bronchial epithelial cells through activation of PERK-eIf2α-ATF4 pathway.

The novel mechanism of human norovirus induced diarrhea: Activation of PKD2 caused by HuNoVs destroyed AQP3 expression through AP2γ in intestinal epithelial cells

Our previous work has demonstrated protein kinase D2 (PKD2) played a critical influence in experimental colitis in animal. However, the role of PKD2 in human norovirus (HuNoVs)-induced diarrhea remained unknown. Aquaporin 3 (AQP3) expression, a critical protein mediating diarrhea, was assessed by western blot, qRT-PCR in intestinal epithelial cells (IECs). Luciferase, IF, IP and ChIP assay were used to explore the mechanism through which HuNoVs regulated AQP3. Herein, we found that AQP3 expression was drastically decreased in IECs in response to VP1 transfection, the major capsid protein of HuNoVs, or HuNoVs infection. Mechanistically, HuNoVs triggered phosphorylation of PKD2 through TLR2/MyD88/IRAK4, which further inhibited AP2γ activation and nuclear translocation, leading to suppress AQP3 transactivation in IECs. Most importantly, PKD2 interacted with MyD88/IRAK4, and VP1 overexpression enhanced this complex form, which, in turn, to increase PKD2 phosphorylation. In addition, endogenous PKD2 interacted with AP2γ, and this interaction was enhanced in response to HuNoVs treatment, and subsequently resulting in AP2γ phosphorylation inhibition. Moreover, inhibition of PKD2 activation could reverse the inhibitory effect of HuNoVs on AQP3 expression. In summary, we established a novel mechanism that HuNoV inhibited AQP3 expression through TLR2/MyD88/IRAK4/PKD2 signaling pathway, targeting PKD2 activity could be a promising strategy for prevention of HuNoVs-induced gastroenteritis.

Integrative metabolome and transcriptome analyses reveal the differences in flavonoid and terpenoid synthesis between Glycyrrhiza uralensis (licorice) leaves and roots

Licorice from Glycyrrhiza uralensis roots is used in foods and medicines. Although we are aware that licorice roots and leaves have distinct material compositions, the specific reasons for these differences remain unknown. Comparison of the metabolomes and transcriptomes between the leaves and roots revealed flavonoids and triterpenoid saponins were significantly different. Isoflavones were enriched in roots because of upregulation of genes encoding chalcone isomerase and flavone synthase, which are involved in isoflavone synthesis. Six triterpenoid saponins were significantly enriched only in the roots. The leaves did not accumulate glycyrrhetinic acid because of low expression levels of genes involved in its synthesis. A gene encoding a UDP glycosyltransferase, which likely catalyzes the key step in the transformation of glycyrrhetinic acid to glycyrrhizin, was screened. Our results provide information about the differences in flavonoid and triterpenoid synthesis between roots and leaves, and highlight targets for genetic engineering.

Supplementary Information

The online version contains supplementary material available at 10.1007/s10068-023-01467-y.

M1 macrophages induce PD-L1hi cell-led collective invasion in HPV-positive head and neck squamous cell carcinoma via TNF-α/CDK4/UPS14

BACKGROUND

Although the roles of PD-L1 in promoting tumor escape from immunosurveillance have been extensively addressed, its non-immune effects on tumor cells remain unclear.

METHODS

The spatial heterogeneity of PD-L1 staining in human papillomavirus (HPV)-positive head and neck squamous cell carcinoma (HNSCC) tissues was identified by immunohistochemistry. Three-dimensional (3D) specific cell-led invasion assay and 3D cancer spheroid model were used to investigate the roles of PD-L1hileader cells in collective invasion. The impact of M1 macrophages on specific PD-L1 expression in leader cells and its mechanisms were further studied. Finally, the effect of combination therapy of anti-PD-L1 and CDK4 inhibitor on HPV-positive tumors were evaluated on a mice model.

RESULTS

Here, we observed a distinctive marginal pattern of PD-L1 expression in HPV-positive HNSCC tissues. By mimicking this spatial pattern of PD-L1 expression in the 3D invasion assay, we found that PD-L1hi cells led the tumor collective invasion. M1 macrophages induced specific PD-L1 expression in leader cells, and depletion of macrophages in tumor-bearing mice abrogated PD-L1hileader cells and collective invasion. Mechanistically, TNF-α secreted by M1 macrophages markedly increased the abundance of PD-L1 via CDK4/ubiquitin-specific peptidase 14-mediated deubiquitination of PD-L1. We also found that suppression of CDK4 enhanced the efficacy of anti-PD-L1 therapy in an E6/E7 murine model.

CONCLUSIONS

Our study identified TNF-α/CDK4/ubiquitin-specific peptidase 14-mediated PD-L1 stability as a novel mechanism underlying M1 macrophage-induced PD-L1hileader cells and collective tumor invasion, and highlighted the potential of the combination therapy of anti-PD-L1 and CDK4 inhibitor for HPV-positive HNSCC.

Robust Piezoelectric Biomolecular Membranes from Eggshell Protein for Wearable Sensors

Flexible and wearable devices are drawing increasing attention due to their promising applications in energy harvesting and sensing. However, the application of wearable devices still faces great challenges, such as flexibility, repeatability, and biodegradability. Biopiezoelectric materials have been regarded as favorable energy-harvesting sources due to their nontoxicity and biocompatibility. Here, a wearable and biodegradable sensor is proposed to monitor human activities. The proposed sensor is fabricated via a low-cost, facile, and scalable electrospinning technology from nanofibers composed of eggshell membranes mixed with polyethylene oxide. It is shown that the sensor exhibits excellent flexibility, outstanding degradability, and mechanical stability over 3000 cycles under periodic stimulation. The device displays multiple potential applications, including the recognition of different objects, human motion monitoring, and active voice recognition. Finally, it is shown that the composite nanofiber membrane has good degradability and breathability. With excellent sensing performance, environmental friendliness, and ease of processing, the eggshell membrane-based sensor could be a promising candidate for greener and more environmentally friendly devices for application in implantable and wearable electronics.

Optimization the Stab Resistance and Flexibility of Ultra-High Molecular Weight Polyethylene Knitted Structure Fabric with Response Surface Method

At present, the challenging issue of the compatibility between stab resistance and flexibility of materials frequently appears. Thus, this study proposes a novel method to enhance the comprehensive performance of the material matrix with stab resistance. Based on the stab-resistant mechanism analysis of the textile matrix, the influence of four factors on the performance of ultra-high molecular weight polyethylene (UHMWPE) knitted fabric was discussed. And, the optimal process conditions of material for achieving high stab resistance and high flexibility were obtained by the response surface method. A series of experiments proved that among all factors, the fabric structure had the greatest influence on the flexible stab-resistant knitted material. Following that, the thickness of the yarn also plays a significant role. Under the optimal process conditions, the stab peak force of the knitted material was promoted to 52.450 N, and the flexibility was enhanced to 93.6%. Meanwhile, through comparison with products that have undergone the same treatment, there was little difference in stab resistance but significantly improved flexibility. It achieves the initial stab resistance and comfortable wearing softness of the fabric through process optimization. This improvement in overall performance of the textile matrix enables further enhancement treatments.

GAD1-mediated GABA elicits aggressive characteristics of human oral cancer cells

Studies suggest that the expression of glutamate decarboxylase 1 (GAD1), γ-aminobutyric acid (GABA), and GABA receptors are involved in tumor progression. However, the underlying mechanisms of high expression and potential functions of GAD1 and GABA in oral squamous cell carcinoma (OSCC) are not known. In this study, we found that the expressions of GAD1 and GABA were considerably increased in OSCC samples, which were closely associated with clinical stage and lymph node metastasis. The knockdown of GAD1 expression significantly inhibited the proliferation, migration and invasion abilities of OSCC cells by reducing the expression of GABA-mediated GABAB receptors, which could be reversed by exogenous GABA, but did not cause excessive OSCC cell proliferation. And GABA secreted by OSCC cells promoted M2 macrophage polarization for inhibiting anti-tumor immunity by activating GABBR1/ERK/Ca2+. In addition, GABA/GABABR promoted the proliferation and progression of OSCC xenograft tumor. Altogether, our results showed that GAD1 synthetized GABA to promote the malignant progression of OSCC and limits the anti-tumor immunity of macrophages, thereby targeting GABA can be a novel strategy for treating OSCC.

[Effects of enhancing the expression of aryl hydrocarbon receptor in post-traumatic mice macrophages on the inflammatory cytokine level and bactericidal ability]

Objective: To explore the expression pattern of aryl hydrocarbon receptor (AhR) in mice peritoneal macrophages (PMs) after major trauma and analyze the effects of enhanced AhR expression on the inflammatory cytokine level and bactericidal ability after trauma. Methods: The experimental study method was used. Forty 6-8-week-old male C57BL/6J mice (the same mouse age, sex, and strain below) were divided into control group, post trauma hour (PTH) 2 group, PTH 6 group, and PTH 12 group according to the random number table (the same grouping method below), with 10 mice in each group. Mice in the latter 3 groups were constructed as severe trauma model with fracture+blood loss, while mice in control group were left untreated. The primary PMs (the same cells below) were extracted from the mice in control group, PTH 2 group, PTH 6 group, and PTH 12 group when uninjured or at PTH 2, 6, and 12, respectively. Then the protein and mRNA expressions of AhR were detected by Western blotting and real-time fluorescence quantitative reverse transcription polymerase chain reaction, respectively, and the gene expressions of AhR signaling pathway related molecules were analyzed by transcriptome sequencing. Twenty mice were divided into control group and PTH 6 group, with 10 mice in each group, and the PMs were extracted. The level of ubiquitin of AhR was detected by immunoprecipitation. Twelve mice were divided into dimethyl sulfoxide (DMSO) alone group, PTH 6+DMSO group, MG-132 alone group, and PTH 6+MG-132 group, with 3 mice in each group. After the corresponding treatment, PMs were extracted, and the protein expression of AhR was detected by Western blotting. Twenty mice were constructed as PTH 6 model. Then, the PMs were extracted and divided into empty negative control adenovirus (Ad-NC) group and AhR overexpression adenovirus (Ad-AhR) group. The protein expression of AhR was detected by Western blotting at 36 h after some PMs were transfected with the corresponding adenovirus. The rest cells in Ad-NC group were divided into Ad-NC alone group and Ad-NC+endotoxin/lipopolysaccharide (LPS) group, and the rest cells in Ad-AhR group were divided into Ad-AhR alone group and Ad-AhR+LPS group. The expressions of interleukin-6 (IL-6) and tumor necrosis factor α (TNF-α) in the cell supernatant were detected by enzyme-linked immunosorbent assay at 12 h after the corresponding treatment (n=6). Twenty mice were obtained to extract PMs. The cells were divided into control+Ad-NC group, PTH 6+Ad-NC group, control+Ad-AhR group, and PTH 6+Ad-AhR group, and the intracellular bacterial load was detected by plate spread method after the corresponding treatment (n=6). Data were statistically analyzed with one-way analysis of variance, least significant difference test, analysis of variance for factorial design, and independent sample t test. Results: Compared with 1.16±0.28 of control group, the protein expressions of AhR in PMs in PTH 2 group (0.59±0.14), PTH 6 group (0.72±0.16), and PTH 12 group (0.71±0.17) were all significantly decreased (P<0.05). The overall comparison of the difference of AhR mRNA expression in PMs among control group, PTH 2 group, PTH 6 group, and PTH 12 group showed no statistical significance (P>0.05). The AhR signaling pathway related molecules included AhR, AhR inhibitor, cytochrome P450 family member 1b1, cytochrome P450 family member 11a1, heat shock protein 90, aryl hydrocarbon receptor-interaction protein, and heat shock protein 70 interaction protein. The heat shock protein 90 expression of PMs in PTH 2 group was higher than that in control group, while the expressions of other molecules did not change significantly after trauma. Compared with that in control group, the level of ubiquitin of AhR in PMs in PTH 6 group was increased. Compared with that in DMSO alone group, the protein expression of AhR in PMs in PTH 6+DMSO group was decreased, while that in PMs in MG-132 alone group had no significant change. Compared with that in PTH 6+DMSO group, the protein expression of AhR in PMs in PTH 6+MG-132 group was up-regulated. At transfection hour 36, compared with that in Ad-NC group, the protein expression of AhR in PMs in Ad-AhR group was increased. At treatment hour 12, compared with those in Ad-NC+LPS group, the expressions of IL-6 and TNF-α in PM supernatant of Ad-AhR+LPS group were significantly decreased (with t values of 4.80 and 3.82, respectively, P<0.05). The number of intracellular bacteria of 1×106 PMs in control+Ad-NC group, PTH 6+Ad-NC group, control+Ad-AhR group, and PTH 6+Ad-AhR group was (3.0±1.8), (41.8±10.2), (1.8±1.2), and (24.2±6.3) colony forming unit, respectively. Compared with that in PTH 6+Ad-NC group, the number of intracellular bacteria of PMs in PTH 6+Ad-AhR group was significantly decreased (t=3.61, P<0.05). Conclusions: Ubiquitin degradation of AhR in PMs of mice after major trauma results in decreased protein expression of AhR. Increasing the expression of AhR in post-traumatic macrophages can reduce the expressions of LPS-induced inflammatory cytokines IL-6 and TNF-α, and improve the bactericidal ability of macrophages after trauma.

Vitronectin Destroyed Intestinal Epithelial Cell Differentiation through Activation of PDE4-Mediated Ferroptosis in Inflammatory Bowel Disease

Objective

Vitronectin (VTN) has been reported to trigger cell pyroptosis to aggravate inflammation in our previous study. However, the function of VTN in inflammatory bowel disease (IBD) remains to be addressed.

Methods

Real-time PCR and western blotting were performed to analyze VTN-regulated intestinal epithelial cell (IEC) differentiation through ferroptosis, and immunofluorescence (IF), luciferase, and chromatin immunoprecipitation were used to identify whether VTN-modulated ferroptosis is dependent on phosphodiesterase 4 (PDE4)/protein kinase A (PKA)/cyclic adenosine monophosphate-response element-binding protein (CREB) cascade pathway. In vivo experiment in mice and a pilot study in patients with IBD were used to confirm inhibition of PDE4-alleviated IECs ferroptosis, leading to cell differentiation during mucosal healing.

Results

Herein, we found that caudal-related homeobox transcription factor 2-mediated IECs differentiation was impaired in response to VTN, which was attributed to enhanced ferroptosis characterized by decreased glutathione peroxidase 4 (GPX4) and solute carrier family 7 member 11 expression. Inhibition of ferroptosis in IECs rescued the inhibitory effect of VTN on cell differentiation. Further analysis showed that VTN triggered phosphorylation of PDE4, leading to inhibit PKA/CREB activation and CREB nuclear translocation, which further reduced GPX4 transactivation. Endogenous PKA interacted with CREB, and this interaction was destroyed in response to VTN stimulation. What is more, overexpression of CREB in CaCO₂ cells overcame the promotion of VTN on ferroptosis. Most importantly, inhibition of PDE4 by roflumilast or dipyridamole could alleviate dextran sulfate sodium-induced colitis in mice and in a pilot clinical study confirmed by IF.

Conclusions

These findings demonstrated that highly expressed VTN disrupted IECs differentiation through PDE4-mediated ferroptosis in IBD, suggesting targeting PDE4 could be a promising therapeutic strategy for patients with IBD.

Paresthesia in dentistry: The ignored neurotoxicity of local anesthetics

Local anesthetics are frequently used by dentists to relieve localized discomfort of the patient and improve treatment conditions. The risk of paresthesia after local anesthesia is frequently encountered in dental clinics. The neurotoxicity of local anesthetics is a disregarded factor in paresthesia. The review summarizes the types of common local anesthetics, incidence and influencing factors of paresthesia after local anesthesia, and systematically describes the neurotoxicity mechanisms of dental local anesthetic. Innovative strategies may be developed to lessen the neurotoxicity and prevent paresthesia following local anesthesia with the support of a substantial understanding of paresthesia and neurotoxicity.

Helicobacter pylori promotes gastric intestinal metaplasia through activation of IRF3-mediated kynurenine pathway

BACKGROUND

Metabolic reprogramming is a critical event for cell fate and function, making it an attractive target for clinical therapy. The function of metabolic reprogramming in Helicobacter pylori (H. pylori)-infected gastric intestinal metaplasia remained to be identified.

METHODS

Xanthurenic acid (XA) was measured in gastric cancer cells treated with H. pylori or H. pylori virulence factor, respectively, and qPCR and WB were performed to detect CDX2 and key metabolic enzymes expression. A subcellular fractionation approach, luciferase and ChIP combined with immunofluorescence were applied to reveal the mechanism underlying H. pylori mediated kynurenine pathway in intestinal metaplasia in vivo and in vitro.

RESULTS

Herein, we, for the first time, demonstrated that H. pylori contributed to gastric intestinal metaplasia characterized by enhanced Caudal-related homeobox transcription factor-2 (CDX2) and mucin2 (MUC2) expression, which was attributed to activation of kynurenine pathway. H. pylori promoted kynurenine aminotransferase II (KAT2)-mediated kynurenine pathway of tryptophan metabolism, leading to XA production, which further induced CDX2 expression in gastric epithelial cells. Mechanically, H. pylori activated cyclic guanylate adenylate synthase (cGAS)-interferon regulatory factor 3 (IRF3) pathway in gastric epithelial cells, leading to enhance IRF3 nuclear translocation and the binding of IRF3 to KAT2 promoter. Inhibition of KAT2 could significantly reverse the effect of H. pylori on CDX2 expression. Also, the rescue phenomenon was observed in gastric epithelial cells treated with H. pylori after IRF3 inhibition in vitro and in vivo. Most importantly, phospho-IRF3 was confirmed to be a clinical positive relationship with CDX2.

CONCLUSION

These finding suggested H. pylori contributed to gastric intestinal metaplasia through KAT2-mediated kynurenine pathway of tryptophan metabolism via cGAS-IRF3 signaling, targeting the kynurenine pathway could be a promising strategy to prevent gastric intestinal metaplasia caused by H. pylori infection. Video Abstract.

LncRNA SELL/L-selectin Promotes HPV-Positive HNSCC Progression and Drives Fucoidan-Mediated Therapeutic Strategies

Positive human papillomavirus (HPV⁺) head and neck squamous cell carcinoma (HNSCC) presents a higher risk of lymph node metastasis and poor prognosis. Here, advanced microarray analysis of clinically collected HNSCC tissues revealed significant upregulation of the lncRNA SELL in HPV⁺ HNSCC, and its overexpression was obviously associated with lymph node metastasis. The lncRNA SELL could function as a promigratory and proinvasive mediator as well as an inducer of M1-like tumour-associated macrophages (TAM) by increasing the level of L-selectin. Furthermore, fucoidan, as an L-selectin inhibitor, obviously weakened the formation of tongue lesions induced by 4-Nitroquinoline N-oxide (4-NQO) in HPV16 E6/E7 transgenic mice. This result drove us to synchronously develop a nanodelivery platform to verify fucoidan-mediated anti-growth and anti-metastasis effects. This work highlighted the important influence of the lncRNA SELL/L-selectin on promoting HPV⁺ HNSCC progression and proposed a potential fucoidan-mediated therapeutic strategy. STATEMENT OF SIGNIFICANCE: Head and neck squamous cell carcinoma (HNSCC) patients with human papillomavirus (HPV) involvement present a greater risk of lymph node metastasis than HPV negative HNSCC patients. However, treatment protocols, including surgery and platinum-based chemo- and radiotherapy, have not improved the 5-year overall survival due to the high tendency of lymphatic metastasis. Here, microarray of clinical HNSCC samples confirms the oncogenic significance of lncRNA SELL, which acts as an M1-like TAM inducer and promotes tumorigenesis by upregulating L-selectin. Fucoidan, as an L-selectin inhibitor, suppresses tongue lesions in transgenic mice, and a fucoidan-mediated nanodelivery platform inhibits HPV⁺ HNSCC growth. The present study highlights lncRNA SELL/L-selectin on promoting HPV⁺ HNSCC progression and proposes a potential fucoidan-mediated therapeutic.

Synergistic contribution of metal-acid sites in selective hydrodeoxygenation of biomass derivatives over Cu/CoOx catalysts

The efficient hydrodeoxygenation (HDO) of biomass derivatives to yield specific products is a significant yet challenging task. In the present study, a Cu/CoO_x catalyst was synthesized using a facile co-precipitation method, and subsequently used for the HDO of biomass derivatives. Under optimal reaction conditions, the conversion of 5-hydroxymethylfurfural reached 100% with a selectivity of ∼99% to 2,5-diformylfuran. In combination with the experimental results, systematic characterizations revealed that CoO_x, as the acid site, tended to adsorb CO bonds, and the metal sites of Cu⁺ were inclined to adsorb CO bonds and enhance CO bond hydrogenation. Meanwhile, Cu⁰ was the main active site for 2-propanol dehydrogenation. The excellent catalytic performance could be attributed to the synergistic effects of Cu and CoO_x. Further, by optimizing the ratio of Cu to CoO_x, the Cu/CoO_x catalysts exhibited notable performance in HDO of acetophenone, levulinic acid, and furfural, which verified the universality of the catalysts in the HDO of biomass derivatives.

Analysis of dental clinic and dental chair distribution in Sichuan

OBJECTIVES

To thoroughly understand the current dental chair equipment status of dental clinics in Sichuan Province and provide a reference for administrative departments.

METHODS

Data were collected from a health administrative department and a regional social development yearbook. The number of existing dental clinics and dental chairs in Sichuan Province was investigated.

RESULTS

In Sichuan Province, 7 103 dental clinics were determined to be equipped with 21 760 dental chairs. The Gini coefficients of per capita dental clinics in the province were 0.50, 0.22, and 0.06, and the Gini coefficients of per capita dental chairs were 0.68, 0.31, and 0.15; these coefficients had the same distribution as that reflected by the Lorenz curve. In consideration of geographic distribution, the Theil index for the distribution of dental clinics and dental chairs among cities and states were 0.690 7 and 0.822 3, respectively. The overall Theil index va-lues for the distribution of dental clinics and dental chairs in the province were 0.902 4 and 1.079 4, respectively. The difference in the distribution of dental clinics and dental chairs among cities and states in the province contributed 0.765 4 and 0.761 8 to the total difference, respectively.

CONCLUSIONS

The allocation of oral health resources in Sichuan Pro-vince is relatively equitable in terms of population and economic distribution but uneven in geographical distribution.

Rabeprazole destroyed gastric epithelial barrier function through FOXF1/STAT3-mediated ZO-1 expression

Rabeprazole is a representative of proton pump inhibitors and widely used in anti-ulcer treatment. However, the effect of Rabeprazole on gut barrier function remains to be identified. In this study, we show that ZO-1 expression is decreased in patients receiving Rabeprazole by immunofluorescence (IF) analysis. Western blotting (WB) and real-time PCR (qPCR) results demonstrate that Rabeprazole treatment leads to a significant downregulation of ZO-1 expression through inhibition of the FOXF1/STAT3 pathway, leading to destroy barrier function, which illustrates a novel pathway that Rabeprazole regulates barrier function in gastric epithelial cells. Mechanistically, Rabeprazole treatment led to a downregulation of STAT3 and FOXF1 phosphorylation, leading to inhibit nuclear translocation and decrease the binding of STAT3 and FOXF1 to ZO-1 promoter, respectively. Most important, endogenous FOXF1 interacted with STAT3, and this interaction was dramatically abolished by Rabeprazole stimulation. Overexpression of STAT3 and FOXF1 in GES-1 cells reversed the inhibitory effect of Rabeprazole on ZO-1 expression, respectively. These finding extended the function of Rabeprazole and established a previously unappreciated mechanism by which the Rabeprazole/FOXF1/STAT3 axis facilitated ZO-1 expression to regulate barrier function, and a comprehensive consideration and evaluation was required in treatment of patients.

Ultra-thin ZrO2overcoating on CuO-ZnO-Al2O3catalyst by atomic layer deposition for improved catalytic performance of CO2hydrogenation to dimethyl ether

An ultra-thin overcoating of zirconium oxide (ZrO₂) film on CuO-ZnO-Al₂O₃(CZA) catalysts by atomic layer deposition (ALD) was proved to enhance the catalytic performance of CZA/HZSM-5 (H form of Zeolite Socony Mobil-5) bifunctional catalysts for hydrogenation of CO₂to dimethyl ether (DME). Under optimal reaction conditions (i.e. 240 °C and 2.8 MPa), the yield of product DME increased from 17.22% for the bare CZA/HZSM-5 catalysts, to 18.40% for the CZA catalyst after 5 cycles of ZrO₂ALD with HZSM-5 catalyst. All the catalysts modified by ZrO₂ALD displayed significantly improved catalytic stability of hydrogenation of CO₂to DME reaction, compared to that of CZA/HZSM-5 bifunctional catalysts. The loss of DME yield in 100 h of reaction was greatly mitigated from 6.20% (loss of absolute value) to 3.01% for the CZA catalyst with 20 cycles of ZrO₂ALD overcoating. Characterizations including hydrogen temperature programmed reduction, x-ray powder diffraction, and x-ray photoelectron spectroscopy revealed that there was strong interaction between Cu active centers and ZrO₂.

Effects of Film Thickness of ALD-Deposited Al2O3, ZrO2 and HfO2 Nano-Layers on the Corrosion Resistance of Ti(N,O)-Coated Stainless Steel

The goal of this stydy was to explore the potential of the enhanced corrosion resistance of Ti(N,O) cathodic arc evaporation-coated 304L stainless steel using oxide nano-layers deposited by atomic layer deposition (ALD). In this study, we deposited Al₂O₃, ZrO₂, and HfO₂ nanolayers of two different thicknesses by ALD onto Ti(N,O)-coated 304L stainless steel surfaces. XRD, EDS, SEM, surface profilometry, and voltammetry investigations of the anticorrosion properties of the coated samples are reported. The amorphous oxide nanolayers homogeneously deposited on the sample surfaces exhibited lower roughness after corrosion attack compared to the Ti(N,O)-coated stainless steel. The best corrosion resistance was obtained for the thickest oxide layers. All samples coated with thicker oxide nanolayers augmented the corrosion resistance of the Ti(N,O)-coated stainless steel in a saline, acidic, and oxidising environment (0.9% NaCl + 6% H₂O₂, pH = 4), which is of interest for building corrosion-resistant housings for advanced oxidation systems such as cavitation and plasma-related electrochemical dielectric barrier discharge for breaking down persistent organic pollutants in water.

Periodontal Pathogens: A Crucial Link Between Periodontal Diseases and Oral Cancer

Emerging evidence shows a striking link between periodontal diseases and various human cancers including oral cancer. And periodontal pathogens, leading to periodontal diseases development, may serve a crucial role in oral cancer. This review elucidated the molecular mechanisms of periodontal pathogens in oral cancer. The pathogens directly engage in their own unique molecular dialogue with the host epithelium to acquire cancer phenotypes, and indirectly induce a proinflammatory environment and carcinogenic substance in favor of cancer development. And functional, rather than compositional, properties of oral microbial community correlated with cancer development are discussed. The effect of periodontal pathogens on periodontal diseases and oral cancer will further detail the pathogenesis of oral cancer and intensify the need of maintaining oral hygiene for the prevention of oral diseases including oral cancer.

Highly stable Pt-Co bimetallic catalysts prepared by atomic layer deposition for selective hydrogenation of cinnamaldehyde

Pt-Co bimetallic catalysts were deposited onγ-Al₂O₃nanoparticles by atomic layer deposition (ALD) and were used for selective hydrogenation of cinnamaldehyde (CAL) to cinnamyl alcohol (COL). High resolution transmission electron microscopy, hydrogen temperature-programmed reduction, x-ray diffraction, and x-ray photoelectron spectroscopy were used to identify the strong interaction between Pt and Co. The obtained catalysts with an optimal Pt/Co ratio achieved a COL selectivity of 81.2% with a CAL conversion of 95.2% under mild conditions (i.e., 10 bar H₂and 80 °C). During the CAL hydrogenation, the addition of Co on Pt significantly improved the activity and selectivity due to the synergetic effects of Pt-Co bimetallic catalysts, resulted from the transfer of electrons from Co to Pt, which can stabilize the carbonyl groups. The obtained Pt-Co bimetallic catalysts also showed excellent stability due to the strong interaction between the metal nanoparticles and the alumina support. Negligible losses in the activity and selectivity were observed during the recycling experiments, showing the potential for practical applications.

AlF3-Al2O3 ALD Thin-Film-Coated Li1.2Mn0.54Co0.13Ni0.13O2 Particles for Lithium-Ion Batteries: Long-Term Protection

Improving the performance of existing cathode materials of lithium-ion batteries (LIBs) through surface modification has been proven to be an effective way to improve the performance of LIBs. However, it is a challenge to use a traditional method to prepare an effective coating film, which meets the requirements of uniformity, continuity, electrochemical stability, and strong mechanical properties. In this study, an ultrathin AlF₃-Al₂O₃ film was coated on the surface of Li_1.2Mn_0.54Co_0.13Ni_0.13O₂ (LRNMC) particles by atomic layer deposition (ALD) in a fluidized bed reactor. A cathode electrolyte interphase layer mainly composed of inorganic components was formed on the surface of AlF₃-Al₂O₃-coated LRNMC during the charge/discharge cycling process, which led to the enhancement of capacity and cycling stability. In addition, the coating layer significantly increased the shelf life of the cathode particles. For LRNMC particles with one cycle of Al₂O₃ ALD and one cycle of AlF₃ ALD coatings, there was no obvious degradation of electrochemical performance after being stored for more than 1 year, indicating long-term protection of ALD films for LIB cathode particles.

Improving the Comprehensive Performance of Na0.7MnO2 for Sodium Ion Batteries by ZrO2 Atomic Layer Deposition

Sodium ion batteries with Na-Mn-O compounds as cathodes have been widely studied as substitutes for lithium ion batteries due to their abundant resources. However, the relatively poor cycling stability and low capacity of Na-Mn-O compounds significantly limit their applications. Different approaches, including element substitution and surface modification, have been applied to improve the electrochemical performance of those cathode materials. Herein, element doping and coating of ZrO₂ on Na_0.7MnO₂ particles have been achieved by atomic layer deposition followed by post-annealing. The rate capability and cycling stability of the modified materials were significantly improved, and the mechanism of performance enhancement was revealed. The ZrO₂ coatings acted as a stable interfacial layer to enhance the cycling stability of Na_0.7MnO₂ by suppressing side reactions between the electrode and electrolyte. The doping of transition metal ions reduced energy barriers for sodium ion insertion and deintercalation during charge/discharge cycling, further improving the charge/discharge capacity and rate performance of Na_0.7MnO₂.

Solvent-Free Solid-State Lithium Battery Based on LiFePO4 and MWCNT/PEO/PVDF-HFP for High-Temperature Applications

Rechargeable lithium-ion batteries (LIBs) have a wide range of applications but face challenges in harsh working or operating environments at high temperatures. In this work, a solid polymer electrolyte with MWCNT-COOH as an additive (MWCNT-SPE) was obtained. MWCNT-SPE has a high thermal stability and can be used in high-temperature operating environments. Solid-state lithium batteries based on MWCNT-SPE and LiFePO₄ were assembled. The resulting lithium batteries exhibited excellent electrochemical properties at 70 and 120 °C, demonstrating a wide range of operations suitable for solid-state batteries with extreme demands. The symmetrical Li/MWCNT-SPE/Li cell operated for 1800 h with low polarization voltage and no short circuit, and the LiFePO₄/MWCNT-SPE/Li cell delivered superior cycling performance under both 0.2 and 0.5 C-rates, indicating that the interface compatibility between the lithium metal and MWCNT-SPE membrane was good and could effectively suppress the formation of lithium dendrites. The superior performance of the resulting MWCNT-SPE was due to the weak interaction between PEO, PVDF-HFP, and MWCNT-COOH, which reduced the tendency of PEO's crystallinity and thereby significantly increased the Li⁺ migration ability and improved the cycling life of the batteries.

LOXL2-enriched small extracellular vesicles mediate hypoxia-induced premetastatic niche and indicates poor outcome of head and neck cancer

Small extracellular vesicles (sEVs) operate as a signaling platform due to their ability to carry functional molecular cargos. However, the role of sEVs in hypoxic tumor microenvironment-mediated premetastatic niche formation remains poorly understood. Methods: Protein expression profile of sEVs derived from normoxic and hypoxic head and neck squamous cell carcinoma (HNSCC) cells were determined by Isobaric Tagging Technology for Relative Quantitation. In vitro invasion assay and in vivo colonization were performed to evaluate the role of sEV-delivering proteins. Results: We identified lysyl oxidase like 2 (LOXL2) which had the highest fold increase in hypoxic sEVs compared with normoxic sEVs. Hypoxic cell-derived sEVs delivered high amounts of LOXL2 to non-hypoxic HNSCC cells to elicit epithelial-to-mesenchymal transition (EMT) and induce the invasion of the recipient cancer cells. Moreover, LOXL2-enriched sEVs were incorporated by distant fibroblasts and activate FAK/Src signaling in recipient fibroblasts. Increased production of fibronectin mediated by FAK/Src signaling recruited myeloid-derived suppressor cells to form a premetastatic niche. Serum sEV LOXL2 can reflect a hypoxic and aggressive tumor type and can serve as an alternative to tissue LOXL2 as an independent prognostic factor of overall survival for patients with HNSCC. Conclusion: sEVs derived from the hypoxic tumor microenvironment of HNSCC can drive local invasion of non-hypoxic HNSCC cells and stimulate premetastatic niche formation by delivering LOXL2 to non-hypoxic HNSCC cells and fibroblasts to induce EMT and fibronectin production, respectively.

Insight Into the Molecular Mechanism of Podophyllotoxin Derivatives as Anticancer Drugs

Podophyllotoxin (PTOX) is a biologically active compound derived from the podophyllum plant, and both it and its derivatives possess excellent antitumor activity. The PTOX derivatives etoposide (VP-16) and teniposide (VM-26) have been approved by the U.S. Food and Drug Administration (FDA) for cancer treatment, but are far from perfect. Hence, numerous PTOX derivatives have been developed to address the major limitations of PTOX, such as systemic toxicity, drug resistance, and low bioavailability. Regarding their anticancer mechanism, extensive studies have revealed that PTOX derivatives can induce cell cycle G2/M arrest and DNA/RNA breaks by targeting tubulin and topoisomerase II, respectively. However, few studies are dedicated to exploring the interactions between PTOX derivatives and downstream cancer-related signaling pathways, which is reasonably important for gaining insight into the role of PTOX. This review provides a comprehensive analysis of the role of PTOX derivatives in the biological behavior of tumors and potential molecular signaling pathways, aiming to help researchers design and develop better PTOX derivatives.

Transcriptomic analyses reveal dynamic changes of defense response in Glycyrrhiza uralensis leaves under enhanced ultraviolet-B radiation

The amount of solar ultraviolet-B (UV-B) radiation reaching the Earth's surface is increasing due to stratospheric ozone dynamics and global climate change. Increased UV-B radiation poses a major threat to ecosystems. Although many studies have focused on the potential effects of enhanced UV-B radiation on plants, the dynamic changes of defense response in plants under continuous UV-B radiation remains enigmatic. In this study, we investigated the effect of UV-B radiation at 0.024 W/m² on the UVR8-and reactive oxygen species (ROS-) signaling pathways, antioxidant system, and wax synthesis of G. uralensis. These parameters were investigated at different UV-B radiation stages (2 h, 6 h, 12 h, 24 h, 48 h, and 96 h). The results revealed that the uvr8 expression level was significantly repressed after 2 h of UV-B radiation, partly because G. uralensis rapidly acclimated to UV-B. Significant H₂O₂ accumulation occurred after 12 h UV-B radiation, resulting in activation of the ROS signaling pathway and the antioxidant system. After 24 h of UV-B radiation, wax synthesis was enhanced alongside a decrease in the capacity of the main antioxidant system. The dynamic and ordered changes in these pathways reveal how different strategies function in G. uralensis at different times during adaption to enhanced UV-B radiation. This study will help us better understand dynamic changes of defense response in plant under enhanced UV-B radiation, further providing fundamental knowledge to develop plant resistance gene resources.

Clinical and CT features of mild-to-moderate COVID-19 cases after two sequential negative nucleic acid testing results: a retrospective analysis

Background

The clinical and imaging features of patients with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections that progressed to coronavirus disease 2019 (COVID-19) have been explored in numerous studies. However, little is known about these features in patients who received negative respiratory nucleic acid test results after the infections resolved. In this study, we aim to describe these features in a group of Chinese patients.

Methods

This retrospective study includes 51 patients with mild-to-moderate COVID-19 (median age: 34.0 years and 47.1% male) between January 31 and February 28, 2020. Demographic, clinical, laboratory, and computed tomography (CT) imaging data were collected before and after two consecutive negative respiratory SARS-CoV-2 tests.

Results

Following a negative test result, the patients’ clinical symptoms continued to recover, but abnormal imaging findings were observed in all moderate cases. Specifically, 77.4% of patients with moderate COVID-19 exhibited multi-lobar lung involvement and lesions were more frequently observed in the lower lobes. The most common CT imaging manifestations were ground-glass opacities (51.6%) and fibrous stripes (54.8%%). Twelve of the 31 patients with moderate COVID-19 underwent repeated chest CT scans after a negative SARS-CoV-2 test. Among them, the ground-glass opacities decreased by > 60% within 1 week in seven patients (58.3%), but by < 5% in four patients (13.8%).

Conclusions

Following a positive and subsequent negative SARS-CoV-2 tests, patients with COVID-19 continued to recover despite exhibiting persistent clinical symptoms and abnormal imaging findings.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12879-021-06013-x.

Fibroblasts in cancer dormancy: foe or friend?

Cancer dormancy is defined that the residual cancer cells could enter into a state of quiescence and patients remain asymptomatic for years or even decades after anti-tumor therapies. Fibroblasts, which represent a predominant cell type in tumor microenvironment, play a pivotal role in determining the ultimate fate of tumor cells. This review recapitulates the pleiotropic roles of fibroblasts which are divided into normal, senescent, cancer-associated fibroblasts (CAFs) and circulation CAFs in tumor dormancy, relapse, metastasis and resistance to therapy to help the treatment of cancer metastasis.

Correlation of the ratio of IgM/IgG concentration to days after symptom onset (IgM/T or IgG/T) with disease severity and outcome in non-critical COVID-19 patients

BACKGROUND

Correlation of SARS-CoV-2 serum antibodies with COVID-19 development and outcome has not been fully studied. Due to the time dynamic of antibodies, the antibody concentration of the same patient varies greatly at different times during the course of the disease. Therefore, our study used IgM/T or IgG/T (the ratio of serum antibody concentration to days after symptom onset) to reflect the patient's humoral immune status, and analyzed their correlation with COVID-19 development and outcome.

METHODS

Clinical data of 50 non-critical COVID-19 patients were retrospectively analyzed. Time-resolved fluorescence immunochromatography was used to quantitatively detect SARS-CoV-2 IgM and IgG. Correlation analysis was performed.

RESULTS

IgM antibody was positive on day 5 of symptom onset, increased within 2 weeks, and then gradually decreased. However, IgG antibody was positive on week 2 of symptom onset and continued to increase since. Additionally, IgM/T, but not IgG/T of recovery period (Spearman ρ=0.17; P=0.283), was negatively correlated with disease course in 2 weeks of symptom onset (Spearman ρ=-0.860; P=0.000). IgG/T of recovery period was positively correlated with clinical classification (Spearman ρ=0.432; P=0.004), number of involved lung lobes (Spearman ρ=0.343; P=0.026), and lung lesions (Spearman ρ=0.472; P=0.002).

CONCLUSIONS

Within 2 weeks of symptom onset, higher IgM/T indicates faster recovery and shorter disease course. In recovery period, higher IgG/T suggests more serious disease. IgM/T or IgG/T may predict disease severity and outcome in non-critical COVID-19 patients.

Small extracellular vesicles containing miR-192/215 mediate hypoxia-induced cancer-associated fibroblast development in head and neck squamous cell carcinoma

The mechanisms underlying the hypoxic cancer cell-mediated differentiation of cancer-associated fibroblasts (CAFs) have not been elucidated yet. The present study showed that the hypoxic head and neck squamous cell carcinoma (HNSCC) cells promoted CAF-like differentiation through secreting TGF-β and small extracellular vesicles (sEVs) that contain enhanced levels of miR-192/215 family miRNAs. Caveolin-1 (CAV1), which is a target gene of miR-192/215, inhibited the TGF-β/SMAD signaling and promoted CAF-like differentiation of the fibroblasts. Restoring the levels of CAV1 inhibited the hypoxic sEV- and TGF-β-induced CAF-like differentiation. The enhanced levels of miR-192/215 encapsulated in the HNSCC tissue-derived sEVs (but not serum-derived sEVs) indicated hypoxic and aggressive cancer stroma. miR-215 in the tumor tissue-derived sEVs (but not circulating sEVs) was correlated with poor overall survival of patients with HNSCC. This study demonstrated that sEVs function as a "courier" to deliver miRNAs from the cancer cells to the fibroblasts, which promotes the remodeling of the hypoxic tumor microenvironment, and that cancer tissue-derived sEV could potentially serve as a source of biomarker.

Pt–Carbon interaction-determined reaction pathway and selectivity for hydrogenation of 5-hydroxymethylfurfural over carbon supported Pt catalysts

In the hydrogenation of HMF, the main product was DHMF over all carbon supported Pt catalysts prepared by impregnation, and it changed to DMF over the Pt catalysts prepared via atomic layer deposition due to the relatively strong Pt–CNT interaction.

Simple Approach: Heat Treatment to Improve the Electrochemical Performance of Commonly Used Anode Electrodes for Lithium-Ion Batteries

The lithium-ion battery (LIB) industry has been in high demand for simple and effective methods to improve the electrochemical performance of LIBs. Here, we treated three different widely studied anode electrodes (i.e., Li₄Ti₅O₁₂, TiO₂, and graphite) under vacuum at 250 °C, and compared their electrochemical performance with and without a 250 °C treatment. Without changing the composition of the fabricated electrodes, all of the 250 °C treated electrodes exhibited enhanced specific capacities, and the lithium-ion diffusion was improved in different degrees. By comparing the results of scanning electron microscopy (SEM) and energy-dispersive spectroscopy of the pristine and 250 °C treated electrodes, the 250 °C treatment improved the distribution of a polyvinylidene difluoride (PVDF) binder in the electrodes, resulting in a higher porosity of the 250 °C treated electrodes. The results of X-ray photoelectron spectrometry and SEM of the cycled electrodes confirmed that a uniform distribution of the PVDF binder from the 250 °C treatment played a positive role in the formation of a solid electrolyte interphase layer, thereby delivering higher capacities and capacity retentions than those of electrodes without heat treatment. The simplicity of this modification method provides considerable potential for building high-performance LIBs at a larger scale.

Atomic Layer Deposited Ni/ZrO2-SiO2 for Combined Capture and Oxidation of VOCs

This work reports on the development of novel Ni nanoparticle-deposited mixed-metal oxides ZrO₂-SiO₂ through atomic layer deposition (ALD) method and their application in combined capture and oxidation of benzene, as a model compound of aromatic VOCs. Concentrating ppm-level VOCs in situ, before their oxidation, offers a practical approach to reduce the catalyst inventory and capital cost associated with VOC emissions abatement. The benzene vapor adsorption isotherms were measured at 25 °C and in the pressure range of 0 to benzene saturation vapor pressure thereof (0.13 bar). In the combined capture-reaction tests, the materials were first exposed to ca. 86 100 ppm_v benzene vapor at 25 °C, followed by desorption and catalytic oxidation while raising the bed temperature to 250 °C. The textural properties revealed that ALD of Ni or ZrO₂ on SiO₂ decreased surface area and pore volume, while sequential doping with ZrO₂ and then Ni caused the otherwise. The benzene vapor adsorption isotherms followed the type-IV isotherm classification, revealing a combination of monolayer-multilayer and capillary condensation adsorption mechanisms in sequence. At saturation vapor pressure, an average equilibrium adsorption capacity of 15 mmol/g was obtained across the materials. However, the dynamic adsorption capacities were up to 50% less than the corresponding equilibrium uptake for the materials. Benzene desorption temperature was observed around 90 °C, and conversion of 85-95% and TOF of 1.28-16.42 mmol_C6H6/mol_Ni/s were obtained over the materials, with 3Ni/ZrO₂-SiO₂, prepared with 3 ALD cycles, exhibiting the maximum conversion and TOF indicating synergistic effects of Ni nanoparticles and ZrO₂ support based on the number of ALD cycles. However, the yields of CO₂ and H₂O were about 5% and 40%, respectively. The small value of the CO₂ yield was hypothesized to be due to simultaneous high-temperature adsorption of CO₂ as the catalytic reaction progressed. The high adsorption affinity, low desorption temperature, and high catalytic activity of the materials investigated in this study made these materials as promising candidates for the abatement of BTX.

Clinical characteristics and risk factors of mild-to-moderate COVID-19 patients with false-negative SARS-CoV-2 nucleic acid

This study investigates the clinical and imaging characteristics of coronavirus disease 2019 (COVID-19) patients with false-negative nucleic acids. Mild-to-moderate COVID-19 patients, including 19 cases of nucleic acid false-negative patients and 31 cases of nucleic acid positive patients, were enrolled. Their epidemiological, clinical, and laboratory examination data and imaging characteristics were analyzed. Risk factors for false negatives were discussed. Compared with the nucleic acid positive group, the false-negative group had less epidemiological exposure (52.6% vs 83.9%; P  = .025), less chest discomfort (5.3% vs 32.3%; P  = .035), and faster recovery (10 [8, 13] vs 15 [11, 18.5] days; P  = .005). The number of involved lung lobes was (2 [1, 2.5] vs 3 [2, 4] days; P  = .004), and the lung damage severity score was (3 [2.5, 4.5] vs 5 [4, 9] days; P  = .007), which was lighter in the nucleic acid false-negative group. Thus, the absence of epidemiological exposure may be a potential risk factor for false-negative nucleic acids. The false-negative cases of COVID-19 are worth noting because they have a risk of viral transmission without positive test results, lighter clinical manifestations, and less history of epidemiological exposure.

Na+-gated water-conducting nanochannels for boosting CO2 conversion to liquid fuels

Robust, gas-impeding water-conduction nanochannels that can sieve water from small gas molecules such as hydrogen (H₂), particularly at high temperature and pressure, are desirable for boosting many important reactions severely restricted by water (the major by-product) both thermodynamically and kinetically. Identifying and constructing such nanochannels into large-area separation membranes without introducing extra defects is challenging. We found that sodium ion (Na⁺)-gated water-conduction nanochannels could be created by assembling NaA zeolite crystals into a continuous, defect-free separation membrane through a rationally designed method. Highly efficient in situ water removal through water-conduction nanochannels led to a substantial increase in carbon dioxide (CO₂) conversion and methanol yield in CO₂ hydrogenation for methanol production.

Myeloid derived suppressor cells contribute to the malignant progression of oral squamous cell carcinoma

Purpose

The tumor-related myeloid derived suppressor cells (MDSCs), important immunosuppressive cells in tumor microenvironment, play an important role in the cancer progression. This study is aimed to investigate the crosstalk between MDSCs and oral squamous cell carcinoma (OSCC) cells and their role in the malignant progression of OSCC.

Methods

Immunochemistry (IHC) was used to investigate the expression of CD33 in 200 OSCC, 36 premalignant. CD33⁺ MDSCs were sorted and enriched via magnetic-activated cell sorting (MACS) from OSCC patients or health donor, and their phenotypes were identified by flow cytometry. With a co-culture system of MDSCs and OSCC, the effects of MDSCs on OSCC proliferation, apoptosis, migration invasion, epithelial-mesenchymal transition (EMT), and vasculogenic mimicry formation (VM) formation were assessed, respectively. Besides, peripheral blood mononuclear cells (PBMCs) from health donor were cultured with OSCC supernatant, the level of MDSCs and expressions of Arginase (Arg-1) and inducible nitric oxide synthase (iNOS) were measured.

Results

The number of MDSCs was increased in tumor tissues of OSCC patients, and was positively related to the T stage, pathological grade, lymph node metastasis and poor prognosis. Tumor-related MDSCs of the co-culture system promoted OSCC progression by contributing to cell proliferation, migration and invasion as well as inducing EMT and VM. In turn, OSCC cells had potential to induce MDSCs differentiation from PBMCs and increase the expression of Arg-1 and iNOS.

Conclusion

These indicated that the crosstalk between MDSCs and tumor cells facilitated the malignant progression of OSCC cells and the immune suppressive properties of MDSCs, which may provide new insights into tumor treatment on targeting tumor-associated immunosuppressive cells.