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Understanding the pathological features of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection in an animal model is crucial for the treatment of coronavirus disease 2019 (COVID-19). Here, we compared immunopathological changes in young and old rhesus macaques (RMs) before and after SARS-CoV-2 infection at the tissue level. Quantitative analysis of multiplex immunofluorescence staining images of formalin-fixed paraffin-embedded (FFPE) sections showed that SARS-CoV-2 infection specifically induced elevated levels of apoptosis, autophagy, and nuclear factor kappa-B (NF-κB) activation of angiotensin-converting enzyme 2 (ACE2)+ cells, and increased interferon α (IFN-α)- and interleukin 6 (IL-6)-secreting cells and C-X-C motif chemokine receptor 3 (CXCR3)+ cells in lung tissue of old RMs. This pathological pattern, which may be related to the age-related pro-inflammatory microenvironment in both lungs and spleens, was significantly correlated with the systemic accumulation of CXCR3+ cells in lungs, spleens, and peripheral blood. Furthermore, the ratio of CXCR3+ to T-box protein expression in T cell (T-bet)+ (CXCR3+/T-bet+ ratio) in CD8+ cells may be used as a predictor of severe COVID-19. These findings uncovered the impact of aging on the immunopathology of early SARS-CoV-2 infection and demonstrated the potential application of CXCR3+ cells in predicting severe COVID-19.

A highly selective PVC membrane electrode for Al3+ based on salicylaldehyde salicyloyl hydrazone as a neutral carrier has been prepared and studied. The sensor exhibits a good response for Al3+ over a linear range of 9.0 × 10-6 to 1.0 × 10-1 mol/L, with a Nernstian slope of 20.0 ± 0.2 mV/decade and detection limit of 7.0 × 10-6 mol/L. Selectivity coefficients determined by the method of separate solution indicate high selectivity for Al3+. The response mechanism was discussed in view of UV-Vis spectroscopy technique and the A.C. impedance technique. It was used as an indicator electrode in potentiometric titration of Al3+ with EDTA and in the determination of Al3+ in real samples. The electrode has a relatively fast response time, long life time and satisfactory stability.

To explore the significance of the ascorbate–glutathione cycle under drought stress, the leaves of 2-year-old potted apple (Malus domestica Borkh.) plants were used to investigate the changes of each component of the ascorbate–glutathione cycle as well as the gene expression of dehydroascorbate reductase (DHAR, EC 1.8.5.1), ascorbate peroxidase (APX, EC 1.11.1.11) and glutathione reductase (GR, EC 1.6.4.2) under drought stress. The results showed that the malondialdehyde (MDA) and H2O2 concentrations in apple leaves increased during drought stress and began to decrease after re-watering. The contents of total ascorbate, reduced ascorbic acid (AsA), total glutathione and glutathione (GSH) were obviously upregulated in apple leaves when the soil water content was 40–45%. With further increase of the drought level, the contents of the antioxidants and especially redox state of AsA and GSH declined. However, levels of them increased again after re-watering. Moreover, drought stress induced significant increase of the activities of enzymes such as APX, scavenging H2O2, and also of monodehydroascorbate reductase (MDHAR, EC 1.6.5.4), DHAR and GR used to regenerate AsA and GSH, especially when the soil water content was above 40–45%. During severe drought stress, activities of the enzymes were decreased and after re-watering increased again. Gene expression of cytoplasmic DHAR, cytoplasmic APX and cytoplasmic GR showed similar changes as the enzyme activities, respectively. The results suggest that the ascorbate–glutathione cycle is up-regulated in response to drought stress, but cannot be regulated at severe drought stress conditions.

This work describes the fabrication of a selective polymeric membrane potentiometric sensor for Al3+ ion based on N,N′-propanediamide bis(2-salicylideneimine) (NPBS) as a neutral carrier. The proposed sensor, with optimum membrane composition, exhibited an excellent near-Nernstian response for Al3+ ion ranging from 7.9 × 10− 7 to 1.0 × 10− 1 mol/L with a detection limit of 4.6 × 10− 7 mol/L and a slope of 19.4 ± 0.3 mV/dec in pH 3.0 nitrate solution at 25 °C. It showed a relatively fast response time (8 s), suitable reproducibility and stability, and good selectivity towards Al3+ ion. The operational pH range of the proposed sensor was 2.5–4.0. The response mechanism was discussed in view of UV–visible spectroscopy and the alternating current (AC) impedance technique. In addition, the proposed sensor was successfully used as an indicator electrode in potentiometric titration of Al3+ ion and in the direct determination of Al3+ ion in real samples.

A nickel(II) [Ni(II)] ion-selective electrode was prepared by incorporating a new N-S Schiff base ligand, glyoxal-bis(S-benzyldithiocarbazate) (GBSB), as a neutral carrier into the PVC matrix. The proposed electrode exhibits an excellent near-Nernstian response for Ni2+ ions, ranging from 2.8 × 10−7 to 1.0 × 10−1 mol/L with a detection limit of 1.2 × 10−7 mol/L and a slope of 31.9 ± 0.3 mV/dec in pH 4.0 nitrate buffer solution at 25°C. It has an appropriate response time and suitable reproducibility and can be used for at least 3 months. The operational pH range of the proposed electrode is 4.0–7.5. The response mechanism is discussed in view of the alternating current (AC) impedance technique. In addition, the electrode was successfully used as an indicator electrode in potentiometric titration of Ni2+ ion and in the direct determination of Ni2+ ion in milk power and chocolate samples.

A novel barium(II) ion-selective polymeric membrane electrode based on a macrocyclic tetrabasic ligand that derived from the reaction of 4,6-diacetylresorcinol and ethylenediamine in the molar ratio 1:1 as neutral carrier was described. The electrode, with optimum membrane composition, exhibited an excellent near-Nernstian response for Ba(2+) ion ranging from 3.6 x 10(-6) to 1.0 x 10(-1) mol/L with a detection limit of 1.9 x 10(-6) mol/L and a slope of 29.7 +/- 0.2 mV/dec in pH 4.0 nitrate buffer solution at 25 degrees C. It had a relatively fast response time (10 s), good selectivity towards Ba(2+) ion, and could be used over a wide pH range of 2.5-7.5. Then, the response mechanism was discussed in view of UV-visible spectroscopy and the A.C. impedance technique. Finally, the proposed electrode was successfully applied to the detection of Ba(2+) ions in real samples as well as in sulfate(II) ions in water.

A novel Cr(III) ion-selective electrode is constructed by incorporating a new aryl amide bifunctional bridging ligand, 2,2'-bis{[(2"-benzylaminoformyl)phenxoyl]methyl}-diethylether (BBPMD) as a neutral carrier into the PVC matrix. The proposed electrode, with optimum membrane composition, exhibits an excellent near-Nernstian response for Cr 3+ ion ranging from 2.8 x 10- 6 to 1.0 × 10 -1 mol/L with a detection limit of 8.6 x 10 -7 mol/L and a slope of 19.5 ± 0.2 mV/dec in pH 3.0 nitrate buffer solution at 25 °C. It has an appropriate response time, suitable reproducibility, and good selectivity towards Cr 3+ ion. The operational pH range of the proposed electrode is 2.5-6.5. The response mechanism was discussed in view of UV-vis spectroscopy and the A. C. impedance technique. The excellent analytical features of the proposed electrode could lead to its successful application as an indicator electrode in potentiometric titration of Cr 3+ ion and in the direct determination of Cr 3+ ion in tea leaves and coffee samples.

Higher plants growing in natural environments experience various stresses. In order to characterize the response of antioxidative system to high temperature, 2-year-old potted apple (Malus domestica Borkh.) plants were exposed to 28 °C as control or high temperature at 40 °C, respectively. The thermal dependent malondialdehyde (MDA) content, hydrogen peroxide (H2O2) content, the activity of protective enzymes, as well as the gene expression of dehydroascorbate reductase (DHAR, EC 1.8.5.1), ascorbate peroxidase (APX, EC 1.11.1.11) and glutathione reductase (GR, EC 1.6.4.2) at control or high temperature were determined after 0, 2, 4, 6 and 8 h treatment. The MDA and H2O2 concentrations in apple leaves increased at the high temperature. The content of total ascorbate, reduced ascorbic acid (AsA), total glutathione (GSH) was the highest at 2 h in the high temperature treatment, followed by a continuous decline with further increases in treatment duration. Activity of protective enzymes reached the highest point at 4 h of high temperature treatment duration, and then decreased. Gene expression of DHAR, APX and GR showed the same changes as the enzyme activities. The results suggest that the ascorbate–glutathione cycle is up-regulated in response to high temperature, but its regulation ability declines obviously after reaching the maximum with further increases in treatment duration.

This study characterized morphological and physiological responses of two Malus species to exogenous abscisic acid (ABA) application under both well-watered and drought-stressed conditions. Exogenous ABA was sprayed onto the leaves of potted 1-year-old seedlings of M. sieversii and M. hupehensis, originated from regions with low annual rainfall and high annual rainfall, respectively. The results demonstrated that exogenous ABA application significantly decreased height growth (H), total biomass (TB), total leaf area (LA), net photosynthesis (A) and stomatal conductance (g s), and significantly increased root/shoot ratio (RS), specific leaf area (SLA), endogenous ABA concentration, water use efficiency (WUE) and carbon isotope composition (δ13C) under both well-watered and drought-stressed conditions. However, distinct interspecific differences were found in ABA-induced morphological and physiological responses. Compared with M. hupehensis, M. sieversii was more responsive to exogenous ABA application, resulting in larger decreases in H, LA, A and g s, and larger increases in RS, SLA, WUEL, WUEi, ABA and δ13C. These results suggest strong evidence for different maintenance of fitness under stressful conditions between species of Malus. In addition, application of exogenous ABA appears to enhance the tolerance of two Malus species to drought-stress.

Sequences of the internal transcribed spacer (ITS) was compared in three seabuckthrons (Hippophae rhamnoides subsp. sinensis, H. tibetana and H. neurocarpa) distributed in Qinghai Province, then the systematic positions of 15 seabuckthron samples were analyzed with Elaeagnaceae angustifolia being outgroup. The results showed that ITS sequences in three seabuckthron species varied in length from 600 to 605 bp. ITS-1, 5.8S and ITS-2 varied from 201 to 203 bp, 166 to 167 bp and 232 to 236 bp, respectively. The sequence divergence among three seabuckthorn species was also remarkably high; Cluster analysis based on ITS indicated that H. gonicocarpa subsp. litangensis and H. gonicocarpa subsp. goniocarpa were distinct and could be classified as H. gonicocarpa and H. litangensis. H. gyantsensis had the closest genetic relationship with H. salicifolia and the distant relationship with H. rhamnoides subsp. sinensis. The positions of nine subspecies of H. rhamnoides based on morphological classification were different from the results of ITS.

To establish a quantitative method of simultaneously determination of swertiamarin, gentiopicroside, mangiferin, swertianolin, isoorientin, 1,8-drihydroxy-3-methoxy-xthanone in Swertia from Qinghai province and Sichuan province by HPLC.The samples were separated on the column of Kromasil C18 (4. 6 mm x 250 mm, 5 microm) which eluted with methanol and water (content 0.02% phosphoric acid). The ratio of methanol increased from 20% to 80% during 20-50 min, and from 80% to 100% during 50-60 min, with detected wavelength 254 nm, flow rate at 1 mL x min(-1), column temperature 35 degrees C.Six compounds were base-isolated, the linear ranges of swertiamarin, gentiopicroside, mangiferin, 4-swertianolin, 5-isoorientin, 1,8-drihydroxy-3-methoxy-xthanone were excellent.The method was rapid and precise, and can be use for controlling medicinal materials quality.

Most genotoxic DNA base modifications localized at key genomic sequences constitute the molecular alterations crucial for mutagenesis and tumorigenesis. We have utilized lesion-rendered inhibition of restriction endonuclease cleavage for the analysis of site-specific DNA damage induced by (±)-7,8-dihydroxy- anti -9,10-epoxy-7,8,9,10-tetrahydrobenzo[ a ]pyrene (benzo[ a ]pyrene diol epoxide, anti -BPDE) in human genes. The H- ras protooncogene and insulin gene sequences were used as targets for modification in vitro and in vivo. Selective induction of individual facultative bands, resulting from covalent modification of the cognate recognition sites, was observed in modified plasmid DNA for a number of restriction nucleases. The ras gene-specific damage, at the Pst I, Bst YI, Not I and Bst EII recognition sites, was visualized and quantitated in human genomic DNA adducted by anti -BPDE. Repair of lesions at hexanucleotide sequences and/or regions surrounding the restriction site, was assessed as a gradual disappearance of facultative bands in DNA from repair-proficient human fibroblasts exposed to the carcinogen in confluent culture. Efficiency of the Pst I site-specific repair was compared at low and high levels of initial damage. Higher genotoxic dose caused a decrease in the extent of adduct removal from the bulk DNA, while the specific site of the ras gene was still subject to fast repair. No measurable Pst I site-specific repair was detected in the insulin gene. These results show the region-selective induction of bulky anti -BPDE DNA damage in non-related genomic targets and suggest that repair of these lesions in human cells proceeds with the efficiency tightly controlled at different levels of initial genotoxic load.