Phase Transition and Luminescent Property Change Induced by Different Organic Cations in One-Dimensional Double Perovskites.

Double perovskites (DPs) have attracted attention in the field of luminescence due to their inherent broadband emission of self-trapping excitons. In this work, we choose [(CH3)3NCH2CHCH2]+ and [CH3CHOHCH2NH2]+ as organic cations to synthesize two new organic-inorganic hybrid DPs, [(CH3)3NCH2CHCH2]2KInCl6 (1) and [CH3CHOHCH2NH2]2KInCl6 (2). The [KCl6]3- and [InCl6]3- octahedra are interchangeably connected by sharing two opposite faces, forming a one-dimensional coordination chain. Each K atom coordinates with six chlorine atoms in 1, while it coordinates with two oxygen atoms in addition to the six chlorine atoms in 2. The coordination between ions K and O in compound 2 may have significantly reduced its luminescence. As a result, compound 1 shows bright-yellow light with a quantum yield of more than 90%, while 2 shows weak blue light with a quantum yield of only 0.98%. In addition, different from no phase transition found in 2, 1 undergoes a reversible phase transition at 324/307 K in the heating-cooling cycle. Through structural and spectral analysis and density functional theory calculation, we conclude that the larger degree of [InCl6]3- octahedral distortion and the larger anion distance (In···In) also cause the PLQY of compound 1 to be higher than that of compound 2.

Routine evaluation of HBV-specific T cell reactivity in chronic hepatitis B using a broad-spectrum T-cell epitope peptide library and ELISpot assay.

BACKGROUND: The clinical routine test of HBV-specific T cell reactivity is still limited due to the high polymorphisms of human leukocyte antigens (HLA) in patient cohort and the lack of universal detection kit, thus the clinical implication remains disputed. METHODS: A broad-spectrum peptide library, which consists of 103 functionally validated CD8+ T-cell epitopes spanning overall HBsAg, HBeAg, HBx and HBpol proteins and fits to the HLA polymorphisms of Chinese and Northeast Asian populations, was grouped into eight peptide pools and was used to establish an ELISpot assay for enumerating the reactive HBV-specific T cells in PBMCs. Totally 294 HBV-infected patients including 203 ones with chronic hepatitis B (CHB), 13 ones in acute resolved stage (R), 52 ones with liver cirrhosis (LC) and 26 ones with hepatocellular carcinoma (HCC) were detected, and 33 CHB patients were longitudinally monitored for 3 times with an interval of 3-5 months. RESULTS: The numbers of reactive HBV-specific T cells were significantly correlated with ALT level, HBsAg level, and disease stage (R, CHB, LC and HCC), and R patients displayed the strongest HBV-specific T cell reactivity while CHB patients showed the weakest one. For 203 CHB patients, the numbers of reactive HBV-specific T cells presented a significantly declined trend when the serum viral DNA load, HBsAg, HBeAg or ALT level gradually increased, but only a very low negative correlation coefficient was defined (r = - 0.21, - 0.21, - 0.27, - 0.079, respectively). Different Nucleotide Analogs (NUCs) did not bring difference on HBV-specific T cell reactivity in the same duration of treatment. NUCs/pegIFN-α combination led to much more reactive HBV-specific T cells than NUCs monotherapy. The dynamic numbers of reactive HBV-specific T cells were obviously increasing in most CHB patients undergoing routine treatment, and the longitudinal trend possess a high predictive power for the hepatitis progression 6 or 12 months later. CONCLUSION: The presented method could be developed into an efficient reference method for the clinical evaluation of cellular immunity. The CHB patients presenting low reactivity of HBV-specific T cells have a worse prognosis for hepatitis progression and should be treated using pegIFN-α to improve host T-cell immunity.

Surface phytolith and pollen assemblages of a low-latitude subtropical region in Southwest China and their implications for vegetation and climate.

Phytoliths, as a newly developing plant proxy, have broad application prospects in paleoclimate and paleoethnobotany. However, the shortage of studies regarding tropical-subtropical plants and topsoil phytoliths interferes with the research progress on primitive humanity's utilization of plant resources and paleoclimate in the region. This research focuses on the subtropical mountainous region with a monsoon climate of low latitudes in Southwest China to conduct phytolith morphology analysis of living plants and phytolith/pollen assemblages of topsoil to reveal the indicative significance of vegetation and climate. A total of 111 species from 50 families, including 73 species from 33 tree/shrub families, 31 species from 12 herb families and 7 species from 5 fern families, were collected for morphological characteristics analysis, as well as 19 topsoil specimens for phytolith and pollen assemblage analysis. The results suggest that phytoliths are mainly deposited in situ, with assemblages of topsoil corresponding well with plant types in the quadrat and being able to exhibit constructive species in small regions. In comparison, pollen assemblages of topsoil dominantly respond to regional vegetation due to their long-distance transportation and widespread presence, in addition to their characteristics that correspond to the vegetation in the quadrat. The topsoil phytolith assemblages are mainly based on the elongate-bulliform flabellate-square/rectangle-broadleaf-types (including spheroid echinate), and the vegetation types indicate the subtropical climate. In addition, phytolith assemblages of Poaceae are dominated by collapsed saddle-bulliform flabellate square/rectangle-elongate-point, reflecting warm and humid conditions. The pollen assemblages mainly consist of Pinus, Betula, Alnus, deciduous Quercus, Euphorbiaceae, Rhamnaceae and Polygonum, reflecting tropical-subtropical plant communities and indicating warm and humid conditions. Overall, phytolith and pollen assemblages have unique characteristics and are thus explicitly representative of the low-latitude subtropical monsoon climate.

Screening and Identification of HBV Epitopes Restricted by Multiple Prevalent HLA-A Allotypes.

Although host T cell immune responses to hepatitis B virus (HBV) have been demonstrated to have important influences on the outcome of HBV infection, the development of T cell epitope-based vaccine and T cell therapy and the clinical evaluation of specific T cell function are currently hampered markedly by the lack of validated HBV T cell epitopes covering broad patients. This study aimed to screen T cell epitopes spanning overall HBsAg, HBeAg, HBx and HBpol proteins and presenting by thirteen prevalent human leukocyte antigen (HLA)-A allotypes which gather a total gene frequency of around 95% in China and Northeast Asia populations. 187 epitopes were in silico predicted. Of which, 62 epitopes were then functionally validated as real-world HBV T cell epitopes by ex vivo IFN-γ ELISPOT assay and in vitro co-cultures using peripheral blood mononuclear cells (PBMCs) from HBV infected patients. Furthermore, the HLA-A cross-restrictions of each epitope were identified by peptide competitive binding assay using transfected HMy2.CIR cell lines, and by HLA-A/peptide docking as well as molecular dynamic simulation. Finally, a peptide library containing 105 validated epitopes which cross-binding by 13 prevalent HLA-A allotypes were used in ELISPOT assay to enumerate HBV-specific T cells for 116 patients with HBV infection. The spot forming units (SFUs) was significantly correlated with serum HBsAg level as confirmed by multivariate linear regression analysis. This study functionally validated 62 T cell epitopes from HBV main proteins and elucidated their HLA-A restrictions and provided an alternative ELISPOT assay using validated epitope peptides rather than conventional overlapping peptides for the clinical evaluation of HBV-specific T cell responses.

Effect of modified endoscopic sinus surgery combined with middle turbinate resection on olfactory function and stress response in patients with refractory chronic rhinosinusitis with nasal polyps.

OBJECTIVE: To investigate the effects of modified endoscopic sinus surgery combined with middle turbinate resection on olfactory function and stress response in patients with refractory chronic rhinosinusitis with nasal polyps (CRSwNP). METHODS: We prospectively selected 92 patients with refractory CRSwNP who were treated in Tianjin 4th Central Hospital from June 2019 to June 2020 as the research subjects. According to the simple randomization of "flipping a coin", they were divided into the observation group (n=50) and the control group (n=42). The observation group was treated with modified endoscopic sinus surgery combined with middle turbinectomy and the control group underwent conventional surgery. The overall response rate, olfactory function, and stress responses of the two groups were compared. RESULTS: A generalized linear model showed that the overall response rate at 2, 4, and 6 months after surgery in the observation group was higher than that in the control group (Wald χ2 group =4.301, Wald χ2 time =91.677, P group =0.038, P time <0.001). Repeated measurements of variance showed no significant differences in olfactory function scores before surgery (P=0.485). After 2, 4, and 6 months, the olfactory function scores of the observation group were higher than those of the control group (P<0.001). After surgery, patients in the observation group had lower Lund-Mackey, Lund-Kennedy, and SNOT-20 scores, and lower epinephrine (E), norepinephrine (NE), and cortisol (Cor) levels than those in the control group (all P<0.001). The observation group had a significantly lower incidence of complications than the control group (10.00% vs. 28.57%, χ2 =5.226, P=0.022). CONCLUSION: Modified endoscopic sinus surgery combined with middle turbinate resection significantly improved the olfactory function and reduced the perioperative stress response of patients with CRSwNP.

Identification of HLA-A2 restricted epitopes of glypican-3 and induction of CTL responses in HLA-A2 transgenic mice.

Hepatocellular carcinoma (HCC) is a malignant tumor with high mortality, but lacks effective treatments. Carcinoembryonic antigen glypican-3 (GPC3) is a tumor-associated antigen overexpressed in HCC but rarely expressed in healthy individuals and thus is one of the most promising therapeutic targets. T cell epitope-based vaccines may bring light to HCC patients, especially to the patients at a late stage. However, few epitopes from GPC3 were identified to date, which limited the application of GPC3-derived epitopes in immunotherapy and T cell function detection. In this study, a total of 25 HLA-A0201 restricted GPC3 epitopes were in silico predicted and selected as candidate epitopes. Then, HLA-A0201+/GPC3+ HCC patients' PBMCs were collected and co-stimulated with the candidate epitope peptides in ex vivo IFN-γ Elispot assay, by which five epitopes were identified as real-world epitopes. Their capacity to elicit specific CD8+ T cells activation and proliferation was further confirmed by in vitro co-cultures of patients' PBMCs with peptide, in vitro co-cultures of healthy donors' PBLs with DCs and peptide, T2 cell binding assay as well as HLA-A2 molecule stability assay. Moreover, the in vivo immunogenicity of the five validated epitopes was confirmed by peptides cocktail/poly(I:C) vaccination in HLA-A0201/DR1 transgenic mice. Robust epitope-specific CD8+ T cell responses and cytotoxicity targeting HepG2 cells were observed as detected by IFN-γ Elispot, intracellular IFN-γ staining and cytolysis assay. This study provided novel GPC3 CTL epitopes for the development of T cell epitope vaccines and evaluation of GPC3 specific T cell responses.

Screening HLA-A-restricted T cell epitopes of SARS-CoV-2 and the induction of CD8+ T cell responses in HLA-A transgenic mice.

Since severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2)-specific T cells have been found to play essential roles in host immune protection and pathology in patients with coronavirus disease 2019 (COVID-19), this study focused on the functional validation of T cell epitopes and the development of vaccines that induce specific T cell responses. A total of 120 CD8+ T cell epitopes from the E, M, N, S, and RdRp proteins were functionally validated. Among these, 110, 15, 6, 14, and 12 epitopes were highly homologous with SARS-CoV, OC43, NL63, HKU1, and 229E, respectively; in addition, four epitopes from the S protein displayed one amino acid that was distinct from the current SARS-CoV-2 variants. Then, 31 epitopes restricted by the HLA-A2 molecule were used to generate peptide cocktail vaccines in combination with Poly(I:C), R848 or poly (lactic-co-glycolic acid) nanoparticles, and these vaccines elicited robust and specific CD8+ T cell responses in HLA-A2/DR1 transgenic mice as well as wild-type mice. In contrast to previous research, this study established a modified DC-peptide-PBL cell coculture system using healthy donor PBMCs to validate the in silico predicted epitopes, provided an epitope library restricted by nine of the most prevalent HLA-A allotypes covering broad Asian populations, and identified the HLA-A restrictions of these validated epitopes using competitive peptide binding experiments with HMy2.CIR cell lines expressing the indicated HLA-A allotype, which initially confirmed the in vivo feasibility of 9- or 10-mer peptide cocktail vaccines against SARS-CoV-2. These data will facilitate the design and development of vaccines that induce antiviral CD8+ T cell responses in COVID-19 patients.

A CuNi Alloy-Carbon Layer Core-Shell Catalyst for Highly Efficient Conversion of Aqueous Formaldehyde to Hydrogen at Room Temperature.

A copper (Cu) material is catalytically active for formaldehyde (HCHO) dehydrogenation to produce H2, but the unsatisfactory efficiency and easy corrosion hinder its practical application. Alloying with other metals and coating a carbon layer outside are recognized as effective strategies to improve the catalytic activity and the long-term durability of nonprecious metal catalysts. Here, highly dispersed CuNi alloy-carbon layer core-shell nanoparticles (CuNi@C) have been developed as a robust catalyst for efficient H2 generation from HCHO aqueous solution at room temperature. Under the optimized reaction conditions, the CuNi@C catalyst exhibits a H2 evolution rate of 110.98 mmol·h-1·g-1, which is 1.5 and 4.9 times higher than those of Cu@C and Ni@C, respectively, which ranks top among the reported nonprecious metal catalysts for catalytic HCHO reforming at room temperature to date. Furthermore, CuNi@C also displays excellent stability toward the catalytic HCHO reforming into H2 in tap water owing to the well-constructed carbon sheath protecting CuNi nanocrystals from oxidation in an alkaline medium. Combined with density functional theory calculations, the superior catalytic efficiency of CuNi@C for H2 generation results from the synergistic contribution between the massive active species from HCHO decomposition on the Cu sites and the remarkable H2 evolution activity on Ni sites. The improved performance of CuNi@C highlights the enormous potential of advancing noble-metal-free nanoalloys as cost-effective and recyclable catalysts for energy recovery from industrial HCHO wastewater.