Temporal Variations in Aboveground Biomass, Nutrient Content, and Ecological Stoichiometry in Young and Middle-Aged Stands of Chinese Fir Forests.

Understanding the ecological dynamics of forest ecosystems, particularly the influence of forest age structure on soil carbon (C), nitrogen (N), and phosphorus (P) content, is crucial for effective forest management and conservation. This study aimed to investigate the nutrient storage and ecological stoichiometry across different-aged stands of Chinese fir forests. Soil samples were collected from various depths (0-15 cm, 15-30 cm, and 30-45 cm) across four age groups of Chinese fir forests (8-year-old, 12-year-old, 20-year-old, and 25-year-old) in the Forest Farm, Pingjiang County, China. Soil organic carbon (SOC), total nitrogen (TN), and total phosphorus (TP) were measured, and their stoichiometries were calculated. The results showed that both individual tree biomass and stand biomass, along with SOC, TN, and TP content, increased with stand age, highlighting the significant importance of stand age on biomass production and nutrient accumulation in forests. Specifically, soil C and P contents significantly increased as the forest aged, while variation in N content was relatively minor. Soil C/N and C/P ratios exhibited variation corresponding to forest age, suggesting alterations in the ecological stoichiometry characteristics of the forests over time. These findings are crucial for understanding the dynamics of ecosystem functioning and nutrient cycling within Chinese fir forests and provide a solid scientific basis for the effective management and conservation of these vital forest ecosystems.

Prognostic value of lactate dehydrogenase in patients with uveal melanoma treated with immune checkpoint inhibition.

OBJECTIVE: We performed the meta-analysis to explore the predictive value of lactate dehydrogenase (LDH) levels in uveal melanoma (UM) patients receiving immune checkpoint inhibitors (ICIs). METHODS: Eligible articles were obtained through EMBASE, PubMed, Google Scholar, and the Cochrane Library, until March 23, 2023. The clinical outcomes evaluated in this study encompassed overall survival (OS) and progression-free survival (PFS). RESULTS: This meta-analysis comprised eight studies with a combined total of 383 patients. The results showed that patients with high LDH levels had noticeably worse OS (HR: 3.445, 95% CI: 2.504-4.740, p < 0.001) and PFS (HR: 1.720, 95% CI: 1.429-2.070, p < 0.001). Subgroup analysis confirmed that the upper limit of normal was the ideal cut-off value for LDH. In multivariate analysis, we also found that high LDH levels significantly predicted shorter OS (HR: 3.405, 95% CI: 1.827-6.348, p < 0.001) and PFS (HR: 2.519, 95% CI: 1.557-4.076, p < 0.001) in UM patients. The sensitivity analysis and publication bias test supported the reliability of our results. CONCLUSIONS: In UM patients treated with ICIs, the LDH levels were reliable indicators of prognosis.

Foliar particulate matter retention and toxic trace element accumulation of six roadside plant species in a subtropical city.

As a major source of air pollution, particulate matter (PM) and associated toxic trace elements pose potentially serious threats to human health and environmental safety. As is known that plants can reduce air PM pollution. However, the relationship between PM of different sizes and toxic trace elements in foliar PM is still unclear. This study was performed to explore the association between PM of different sizes (PM2.5, PM10, PM>10) and toxic trace elements (As, Al, Cu, Zn, Cd, Fe, Pb) as well as the correlation among toxic trace elements of six roadside plant species (Cinnamomum camphora, Osmanthus fragrans, Magnolia grandiflora, Podocarpus macrophyllus, Loropetalum chinense var. rubrum and Pittosporum tobira) in Changsha, Hunan Province, China. Results showed that P. macrophyllus had the highest ability to retain PM, and C. camphora excelled in retaining PM2.5. The combination of P. macrophyllus and C. camphora was highly recommended to be planted in the subtropical city to effectively reduce PM. The toxic trace elements accumulated in foliar PM varied with plant species and PM size. Two-way ANOVA showed that most of the toxic trace elements were significantly influenced by plant species, PM size, and their interactions (P < 0.05). Additionally, linear regression and correlation analyses further demonstrated the homology of most toxic trace elements in foliar PM, i.e., confirming plants as predictors of PM sources as well as environmental monitoring. These findings contribute to urban air pollution control and landscape configuration optimization.

Ecological Stoichiometry and Stock Distribution of C, N, and P in Three Forest Types in a Karst Region of China.

Ecological stoichiometry plays important roles in understanding the nutrient constraints on tree growth and development, as well in maintaining ecosystem services in forests, yet the characteristics of carbon:nitrogen:phosphorous (C:N:P) stoichiometry in forests under karst environment have not been sufficiently evaluated. In this study, concentration, distribution, stocks of Nitrogen (N) and Phosphorous (P), and ecological stoichiometry were studied in three common forest types: Masson pine natural forests (MPNF), Masson pine plantation forests (MPPF), and Slash pine plantation forests (SPPF) in a karst region of southwestern China. Results showed that N concentrations were higher in overstory than in understory and litter in the studied forests. However, P concentration was relatively low in overstory component of the forested ecosystems. Meanwhile, the N and P concentrations were higher in SPPF in the stem and litter, while these contents were higher in MPPF and MPNP in the overstory and understory. The N and P stocks ranged from 5.7-6.2 t ha-1, and 0.5-0.6 t ha-1 in the examined forests. The ecological stoichiometry of C:N:P in the three forest types was similar in litter (46-49:2:1), and relatively steady in soil (250-320:13-16:1) and tree leaf (100-200:14-20:1). Soil P status was the primary limiting factor in affecting tree growth in MPPF and SPPF (N:P ratio > 16), while both N and P conditions were the main restrictive factors in MPNP (N:P ratio = 15) in the study area. Our study provides scientific references and useful datasets of C:N:P stoichiometry for sustainable management of forest ecosystems in karst regions.

Cold Acclimation and Supercooling Capacity of Agasicles hygrophila Adults.

Agasicles hygrophila Selman and Vogt is used in the biological control of the invasive weed Alternanthera philoxeroides (Mart.) Griseb. However, with the northward establishment of A. philoxeroides in China, the weak adaptivity of A. hygrophila to cold weather has resulted in the ineffective control of A. philoxeroides in northern China. Cold acclimation can significantly enhance insect cold tolerance, enabling them to cope with more frequent climate fluctuations. To improve the biological control efficacy of A. hygrophila in cold climates, we compared the effects of rapid cold hardening and acclimation on A. hygrophila under laboratory conditions. On initially transferring adults from 26 to -10 °C for 2 h, mortality reached 80%. However, when pre-exposed to 0 °C for 2 h and then transferred to -10 °C for 2 h, adult mortality was reduced to 36.67%. These findings indicate that cold acclimation can enhance the cold tolerance of A. hygrophila under laboratory conditions. However, the beneficial cold acclimation effects waned after more than 15 min of recovery at 26 °C. Exposure to 15 °C for 24 h or gradual cooling from 0 to -10 °C at 1 °C·min-1 also induced cold acclimation, indicating that long-term cold and fluctuating cold acclimation are also potentially effective strategies for enhancing low-temperature tolerance.

Porphyrin derivative-based tandem response nanochannels triggered by Zn2+ and NO.

We describe tandem response solid nanochannels tailored with a porphyrin derivative that show Zn2+ and NO gating behaviors with good selectivity, stability, and reversibility. EXAFS and fluorescence experiments showed that zinc coordinated with the porphyrin derivative as the ratio of 1 : 1 with the binding constant for 3.39 × 105 M-1. These studies are beneficial for simulating the physiological functions of ion/gas in organisms and have the potential for designing complicated logic circuits and fabricating novel biosensors.

Regulatory Mechanism of Transcription Factor AhHsf Modulates AhHsp70 Transcriptional Expression Enhancing Heat Tolerance in Agasicles hygrophila (Coleoptera: Chrysomelidae).

Agasicles hygrophila is a classical biological agent used to control alligator weed (Alternanthera philoxeroides). Previous research has indicated that the heat shock factor (HSF) is involved in regulating the transcriptional expression of Hsp70 in response to heat resistance in A. hygrophila. However, the regulatory mechanism by which AhHsf regulates the expression of AhHsp70 remains largely unknown. Here, we identified and cloned a 944 bp AhHsp70 promoter (AhHsp70p) region from A. hygrophila. Subsequent bioinformatics analysis revealed that the AhHsp70p sequence contains multiple functional elements and has a common TATA box approximately 30 bp upstream of the transcription start site, with transcription commencing at a purine base approximately 137 bp upstream of ATG. Promoter deletion analyses revealed that the sequence from -944 to -744 bp was the core regulatory region. A dual-luciferase reporter assay indicated that overexpressed AhHsf significantly enhanced the activity of AhHsp70p. Furthermore, qPCR showed that AhHsp70 expression increased with time in Spodoptera frugiperda (Sf9) cells, and AhHsf overexpression significantly upregulated AhHsp70 expression in vitro. Characterization of the upstream regulatory mechanisms demonstrated that AhHsf binds to upstream cis-acting elements in the promoter region of AhHsp70 from -944 to -744 bp to activate the AhHSF-AhHSP pathway at the transcriptional level to protect A. hygrophila from high temperature damage. Furthermore, we proposed a molecular model of AhHsf modulation of AhHsp70 transcription following heat shock in A. hygrophila. The findings of this study suggest that enhancing the heat tolerance of A. hygrophila by modulating the upstream pathways of the Hsp family can improve the biocontrol of A. philoxeroides.

Highly Emissive Multipurpose Organoplatinum(II) Metallacycles with Contrasting Mechanoresponsive Features.

The development of supramolecular coordination complexes (SCCs) with a bright aggregate state or mechanical-stimuli-responsive luminescence is very significant and challenging. Herein, we report the synthesis of three different supramolecular platinum(II) metallacycles via coordination-driven self-assembly of a diplatinum(II) acceptor and organic donors with a triphenylamine, carbazole, or tetraphenylethylene moiety. The triphenylamine-modified SCC exhibits aggregation-induced emission enhancement (AIEE) but no mechanofluorochromism. The carbazole and tetraphenylethylene-based SCCs exhibit changes in aggregate fluorescence and also exhibit reversible mechanofluorochromism. This work not only reports three rare metallacycles with AIEE, aggregate fluorescence change, or mechanofluorochromic nature but also explores their potential applications in cell imaging and solid-state lighting.

Facile surface functionalization of MXene by pillar[5]arene for enhanced electrochemical performance.

A simple strategy was used to prepare functional two-dimensional materials via the combination of pillar[5]arene (P5) and MXene. The electrochemical results of MXene-P5 exhibit high supramolecular recognition, enrichment capability, and high electrochemical response toward dye molecules, which are probably due to the synergetic effects from high conductivity, high surface area, and host-guest recognition. This study provides a promising electrochemical sensing platform based on different kinds of pillararenes.

[Association between single nucleotide polymorphisms in -88 and -123 loci of MxA gene promoter region and HCV susceptibility and IFN-α efficacy].

AIM: To investigate the association between the single nucleotide polymorphisms(SNP) in -88 and -123 loci of myxovirus resistance 1(MxA) gene promoter region and the susceptibility to heptaitis C virus(HCV) in Han Chinese, and evaluate the relationship between all of the genotypes and the treatment response to IFN-α. METHODS: Genotypes of -88(G/T) and -123(C/A) loci of the MxA promoter were examined by the polymerase chain reaction and restriction fragment length polymorphism(PCR-RFLP) in 46 patients with chronic hepatitis C(CHC group) and 50 healthy controls(HC group). The indexes for evaluating the curative effect were the biochemical and virological response rates(RVR/EVR/ETVR/SVR). RESULTS: There was no statistical significance in frequency distribution difference of the genotypes and alleles of -88/-123 loci between CHC and CH groups(P>0.05): the T-alleles of MxA-88 locus and the A-alleles of MxA-123 locus may be not associated with the susceptibility to HCV(OR95%CI: 0.60-1.96, 0.35-1.14, respectively). The level of ALT increased and was positively correlated with HCV-RNA load(r=0.931). No significant difference was discovered in terms of the HCV viral load and the ALT levels among different genotypes of -88 or -123 loci(P>0.05). IFN-α treatment response rates were also not significantly different among -88G/T, -123C/A and MxA-88/-123(P>0.05). CONCLUSION: There is no distinct correlation between the SNP of MxA-88G/T and MxA-123C/A loci and HCV susceptibility, but the MxA-88T/-123A gene variants may indirectly increase the risk for HCV infection, and the MxA-88T gene mutation may be related to IFN-α antiviral efficacy and the outcomes of HCV infection.