Spatio-temporal distribution characteristics and influencing factors of protoporphyrin IX in the estuarine-coastal ecosystems.

Protoporphyrin IX (PPIX), a key precursor for the synthesis of chlorophyll and heme, is fundamental to photosynthetic eukaryotic cells and participates in light absorption, energy transduction, and numerous other cellular metabolic activities. Along with the application of genetic and biochemical techniques over the past few years, our understanding of the formation of PPIX has been largely advanced, especially regarding possible metabolic pathways. However, the ecological role and function of PPIX in natural ecosystems remains unclear. We have previously established a method for quantifying PPIX in marine ecosystems. Here, our results provide evidence that PPIX is not only subtly linked to nutrient uptake but also triggers phytoplankton productivity. PPIX and its derivatives are dynamic spatiotemporally in direct response to increased nutrient availability. Using 16 S rRNA gene amplicon sequencing, PPIX was revealed to interact strongly with many microorganisms, indicating that PPIX serves as a critical metabolite in maintaining microbial metabolism and community development. In summary, we observed that PPIX is linearly related to nutrient availability and microbial diversity. The levels of microbial PPIX reflect ecological health, and the availability of PPIX and nutrients jointly affect microbial community composition.

Time-Dependent Factors Influencing Cardiocerebral Vascular Events in Chronic Hemodialysis Patients: Insights from a Longitudinal Study.

BACKGROUND Cardiocerebral vascular events (CVCs) are significant complications in patients undergoing hemodialysis (HD). Given the increased morbidity and mortality associated with CVCs in this population, understanding the factors influencing CVC occurrence over time is crucial. This study aimed to investigate these time-dependent factors in HD patients. MATERIAL AND METHODS A total of 228 HD patients from 2 dialysis centers, with at least 3 months of treatment between 2017 and 2021, were included. Annual clinical data were collected, and patients were monitored until CVC development. Kaplan-Meier analysis and a time-dependent Cox regression model were used for data analysis. RESULTS The mean age of 228 patients was 55.0±15.0 years, and 64.76% were male. For 5 years of monitoring, the mean follow-up interval was 3.1±1.0 years for patients to develop CVCs. The 1-year, 3-year, and 5-year CVC-free rates were 97.47%, 81.31%, and 70.71%, respectively. Time-dependent Cox regression revealed that C-reactive protein was an independent time-dependent risk factor in HD patients and blood flow rate was an independent time-dependent protective factor. The male subgroup and non-diabetic subgroup had these same results. The following were was the independent time-dependent risk factors: white blood cell count for the female subgroup; blood flow rate for the non-elderly subgroup; and C-reactive protein for the diabetic subgroup. None were risk factors for the elderly subgroup. CONCLUSIONS It took an average of 3.1±1.0 years for patients with HD to develop CVCs. C-reactive protein and blood flow rate emerged as key time-dependent influencing factors for CVCs in this population.

LncRNA SNHG16 regulates RAS and NF-κB pathway-mediated NLRP3 inflammasome activation to aggravate diabetes nephropathy through stabilizing TLR4.

AIMS: LncRNA SNHG16 and Toll-like receptor-4 (TLR4) participate in diabetes nephropathy. This study investigated whether SNHG16 regulates diabetic renal injury (DRI) via TLR4 and its related mechanism. METHODS: Diabetic mice and high glucose (HG)-induced HRMCs were used to examine the expressions of SNHG16 and TLR4. The SNHG16 expression, cytokines, reactive oxygen species, MDA, SOD, GSH, and fibrosis-related proteins were evaluated in HG-induced HRMCs transfected with sh-NC or sh-SHNG16. RNA immunoprecipitation and RNA pull-down determined the interaction between SNHG16 and EIF4A3 or TLR4 and EIF4A3. We used HG-treated HRMCs or diabetic mice to investigate the roles of TLR4 or SNHG16 in renal injuries. RESULTS: Both SNHG16 and TLR4 were upregulated in diabetic conditions. HG increased serum Scr and BUN, led to significant fibrosis, increased inflammation- and renal fibrosis-related proteins in mice, and increased ROS, MDA, and decreased SOD and GSH in HRMCs. SNHG16 silencing diminished HG-upregulated SNHG16, decreased HG-increased cytokines secretion, ROS, MDA, and fibrosis but increased SOD and GSH. RIP and RNA pull-down confirmed that SNHG16 recruits EIF4A3 to stabilize TLR4 mRNA. TLR4 knockdown alleviated HG-induced renal injuries by suppressing RAS and NF-κB-mediated activation of NLRP3 inflammasomes. SNHG16 knockdown alleviated HG-induced renal injuries in HG-induced HRMCs or diabetic mice. Interestingly, TLR4 overexpression reversed the effects of SNHG16 knockdown. Mechanistically, SNHG16 knockdown alleviated HG-induced renal injuries by suppressing TLR4. CONCLUSION: SNHG16 accelerated HG-induced renal injuries via recruiting EIF4A3 to enhance the stabilization of TLR4 mRNA. The SNGHG16/ELF4A3/TLR4 axis might be a novel target for treating DRI.

[Spatial and Temporal Distribution and Influencing Factors of Dissolved Trace Metals in Jiulong River Estuary and Xiamen Bay].

Trace metals play an important role in some biogeochemical processes in the marine system. The physical and hydrological conditions in estuaries and coastal seawater are complicated and significantly affected by human activities. Therefore, the biogeochemical behavior and influencing mechanism of trace metals in nearshore water have become a research hotspot. Jiulong River estuary and Xiamen Bay are located in the coastal areas of Fujian Province, which are significantly influenced by Longyan, Xiamen, and Zhangzhou City. In July 2021, November 2021, and January 2022, the trace metals chromium (Cr), manganese (Mn), cobalt (Co), nickel (Ni), copper (Cu), and cadmium (Cd) and environmental factors (water temperature, salinity, pH, dissolved oxygen (DO), suspended particulate matter (SPM), etc.) in Jiulong River estuary and Xiamen Bay were investigated. The results showed that the order of trace metal concentration average values measured in Jiulong River estuary and Xiamen Bay was Mn>Ni>Cu>Cr>Co>Cd. In July 2021, the average values of ρ(Cr), ρ(Mn), ρ(Co), ρ(Ni), ρ(Cu), and ρ(Cd) were 0.159, 47.96, 0.068, 1.56, 1.07, and 0.016 µg·L-1, respectively. In November 2021, the average values were 0.216, 8.48, 0.030, 1.70, 1.92, and 0.019 µg·L-1, respectively. The average concentrations in January 2022 were 0.281, 32.39, 0.062, 2.21, 1.54, and 0.034 µg·L-1, respectively. The concentration of dissolved metals in the estuary was higher than that in the bay area. Principal component analysis showed that the main factors affecting the concentrations of dissolved trace metals were river runoff and anthropogenic activities.

Performing In Vivo and Ex Vivo Electrical Impedance Myography in Rodents.

Electrical impedance myography (EIM) is a convenient technique that can be used in preclinical and clinical studies to assess muscle tissue health and disease. EIM is obtained by applying a low-intensity, directionally focused, electrical current to a muscle of interest across a range of frequencies (i.e., from 1 kHz to 10 MHz) and recording the resulting voltages. From these, several standard impedance components, including the reactance, resistance, and phase, are obtained. When performing ex vivo measurements on excised muscle, the inherent passive electrical properties of the tissue, namely the conductivity and relative permittivity, can also be calculated. EIM has been used extensively in animals and humans to diagnose and track muscle alterations in a variety of diseases, in relation to simple disuse atrophy, or as a measure of therapeutic intervention. Clinically, EIM offers the potential to track disease progression over time and to assess the impact of therapeutic interventions, thus offering the opportunity to shorten the clinical trial duration and reduce sample size requirements. Because it can be performed noninvasively or minimally invasively in living animal models as well as humans, EIM offers the potential to serve as a novel translational tool enabling both preclinical and clinical development. This article provides step-by-step instructions on how to perform in vivo and ex vivo EIM measurements in mice and rats, including approaches to adapt the techniques to specific conditions, such as for use in pups or obese animals.

Phthalate exposure and DNA oxidative damage in young people of takeaway food lovers.

Numerous studies have demonstrated the ubiquitous of phthalates in materials of food and food packaging, and the effects of regular eating takeaway food for a long time on human health and phthalate exposure levels were not fully investigated. A total of 288 college students who love eating takeaway food were recruited to explore phthalate exposure and oxidative stress, by measuring metabolites of traditional or alternative phthalates and 8-hydroxydeoxyguanosine (8-OHdG, a biomarker of DNA oxidative damage) in their urine samples. Both traditional and alternative phthalates were highly detected. Based on weekly frequency of takeaway eating collecting from questionnaire, the students were divided into four groups including level 1 (L1, < 3 times), level 2 (L2, 3-7 times), level 3 (L3, 8-12 times) and level 4 (L4, > 12 times). The total concentrations of all phthalate metabolites were 42.5-893 ng/mL in all students, which were significantly different among four groups, with the lowest level in L1 (p < 0.05). Checking with the generalized linear model (L1 as the reference), the concentrations of most phthalate metabolites increased 12.0-144% in L2 and L3 compared with those in L1. For each group increase, the concentrations of total metabolites, and metabolites of high and low molecular weight phthalates will increase by 0.156%, 0.128%, and 0.142%, respectively. Besides, levels of 8-OHdG (0.639-33.7 ng/mL) were positively correlated with phthalate daily exposure doses. The each increase of a percentage unit of daily exposure of phthalates, the concentrations of 8-OHdG will increase by 0.258-0.405%. However, levels of 8-OHdG were not significantly different among the four groups. The alternative phthalates have already entered the body of Chinese young people. Our results indicated the regular consumption of takeaway food (e.g., more than three times per week) may increase the chance of exposure to certain phthalates, and may not significantly increase the levels of DNA oxidative damage, unless exposed to other pollutants such as phthalates.

A novel method for estimating the fractional Cole impedance model using single-frequency DC-biased sinusoidal excitation.

OBJECTIVE: The Cole model is a widely used fractional circuit model in electrical bioimpedance applications for evaluating the content and status of biological tissues and fluids. Existing methods for estimating the Cole impedance parameters are often based on multi-frequency data obtained from stepped-sine measurements fitted using a complex non-linear least square (CNLS) algorithm. Newly emerged numerical methods from the magnitude of electrical bio-impedance data-only do not need CNLS fitting, but they still require multi-frequency stepped-sine data. This study proposes a novel approach to estimating the Cole impedance parameters that combines a numerical and time-domain fitting method based on a single-frequency DC-biased sinusoidal current excitation. APPROACH: First, the transient and steady-state voltage response along with the current excitation are acquired in electrical bio-impedance measurement. From the sampled data, a numerical method is applied to provide the initial estimation of the Cole impedance parameters, which are then used in a time-domain iterative fitting algorithm. RESULTS: The accuracy of the algorithm proposed is tested with noisy electrical bio-impedance simulations. The maximum relative error of the estimated Cole impedance parameters is 1% considering 2% (34 dB) additive Gaussian noise. Experimental measurements performed on a 2R-1C circuit and some fruit samples show a mean difference less than 1% and 5% respectively compared to the Cole impedance parameters estimated from a commercial electrical bio-impedance analyzer performing stepped-sine measurements and CNLS fitting. SIGNIFICANCE: This is the first method that allows estimating the Cole impedance parameters from single-frequency electrical bio-impedance data. The approach presented could find broad use in many applications, including single-frequency body impedance analysis.

Gas products generation mechanism during co-pyrolysis of styrene-butadiene rubber and natural rubber.

In this study, reaction molecular dynamics were combined with experiments to gain in-depth understanding of the gaseous pyrolysis products generation mechanism and optimal paths during natural rubber (NR), styrene-butadiene rubber (SBR) and mixed rubbers (NR-SBR) for effective recovery of waste rubber. The results show that the pyrolysis temperature of NR increases gradually with SBR addition. The monomers produced during the initial stage of SBR pyrolysis are mainly 1,3-butadiene and styrene, in which the energy barriers of the formed H and CH2=CH in styrene are higher than those in 1,3-butadiene, and during further pyrolysis the main gas products are H2 and CH4. During co-pyrolysis of NR-SBR, the reaction paths show that increasing H2 yield and decreasing CH4 yield take place easily as SBR content rises. By contrast to pyrolysis of NR, the path of generating CH2=CH in SBR is more difficult while that of CH2=CH abstracting H occurred easily, leading to first enhancement in produced CH2=CH2 followed by a decline. Fixed bed experiments and gas chromatography (GC) analysis identify the main gas products of the three rubbers (NR, SBR, NR-SBR)as H2, CH4 and CH2=CH2 and the change of yield caused by the increase of SBR content are consistent with the simulation results.

Numerical estimation of Fricke-Morse impedance model parameters using single-frequency sinusoidal excitation.

OBJECTIVE: The Fricke-Morse impedance model is widely used in bioelectrical impedance analysis (BIA), which is usually fitted by multi-frequency electrical impedance data. Here, we propose a novel numerical method for estimating the model parameters using single-frequency sinusoidal excitation. APPROACH: A single-frequency sinusoidal signal is used as the current excitation, from which the initial transient, the steady-state and the ending transient voltage responses along with the current excitation are recorded. The model parameters can be then estimated with numerical calculations from the acquired signals. MAIN RESULTS: Simulation and experimental measurements are verified on a 2R1C circuit by using a 50 kHz sinusoidal current excitation. The results show that the maximum relative errors of the estimated model parameters are <1% in simulation with 2% noise and <2% in experimental measurement. SIGNIFICANCE: The proposed method could extend the applications of wideband BIA by using single-frequency excitation, rather than multi-frequency excitation as is done today.

TGF-ß-Induced CD8+CD103+ Regulatory T Cells Show Potent Therapeutic Effect on Chronic Graft-versus-Host Disease Lupus by Suppressing B Cells.

Lupus nephritis is one of most severe complications of systemic erythematosus lupus and current approaches are not curative for lupus nephritis. Although CD4+Foxp3+ regulatory T cells (Treg) are crucial for prevention of autoimmunity, the therapeutic effect of these cells on lupus nephritis is not satisfactory. We previously reported that CD8+CD103+ Treg induced ex vivo with TGF-ß1 and IL-2 (CD8+CD103+ iTreg), regardless of Foxp3 expression, displayed potent immunosuppressive effect on Th cell response and had therapeutic effect on Th cell-mediated colitis. Here, we tested whether CD8+CD103+ iTreg can ameliorate lupus nephritis and determined potential molecular mechanisms. Adoptive transfer of CD8+CD103+ iTreg but not control cells to chronic graft-versus-host disease with a typical lupus syndrome showed decreased levels of autoantibodies and proteinuria, reduced renal pathological lesions, lowered renal deposition of IgG/C3, and improved survival. CD8+CD103+ iTreg cells suppressed not only T helper cells but also B cell responses directly that may involve in both TGF-ß and IL-10 signals. Using RNA-seq, we demonstrated CD8+CD103+ iTreg have its own unique expression profiles of transcription factors. Thus, current study has identified and extended the target cells of CD8+CD103+ iTreg and provided a possible application of this new iTreg subset on lupus nephritis and other autoimmune diseases.

Low level of circulating basophil counts in biopsy-proven active lupus nephritis.

Basophils have been shown to be important players in promoting lupus nephritis (LN). However, the relationship between circulating basophil counts and renal pathology activity of LN remains unclear. In this retrospective study, 159 clinical and pathology samples from patients with biopsy-proven LN were analyzed. The renal activity and classification were evaluated according to renal pathology. The correlations between circulating basophil counts and renal pathology activity index were assessed. Overall, circulating basophil counts correlated with total systemic lupus erythematosus disease activity index (SLEDAI) score (r = - 0.31), renal SLEDAI score (r = - 0.35), activity index (AI) score(r = - 0.40), and renal histologic activity parameters (p < 0.05, respectively). Compared with systemic lupus erythematosus (SLE) non-LN patients, the LN group had lower basophil counts (0.007 ± 0.007 vs. 0.011 ± 0.010 × 109/L, p = 0.04). Subgroup analyses revealed that the circulating basophil counts in group B (AI > 8) were significantly lower than that in group A (AI ≤ 8) (0.004 ± 0.006 vs. 0.009 ± 0.009 × 109/L, p < 0.001). The difference was still significant when eliminating the influence of SLEDAI. Significant differences were found in circulating basophil counts among LN pathology classification groups (p < 0.01). Groups of classes III, IV, and V were more likely to have lower circulating basophil counts when compared with group of class I/II (p < 0.05). These findings suggest a potential role of circulating basophil counts as a convenient and helpful marker for renal activity of LN.

Infrared imaging diagnostics for intense pulsed electron beam.

Infrared imaging diagnostic method for two-dimensional calorimetric diagnostics has been developed for intense pulsed electron beam (IPEB). By using a 100-µm-thick tungsten film as the infrared heat sink for IPEB, the emitting uniformity of the electron source can be analyzed to evaluate the efficiency and stability of the diode system. Two-dimensional axisymmetric finite element method heat transfer simulation, combined with Monte Carlo calculation, was performed for error estimation and optimization of the method. The test of the method was finished with IPEB generated by explosive emission electron diode with pulse duration (FWHM) of 80 ns, electron energy up to 450 keV, and a total beam current of over 1 kA. The results showed that it is possible to measure the cross-sectional energy density distribution of IPEB with energy sensitivity of 0.1 J/cm(2) and spatial resolution of 1 mm. The technical details, such as irradiation protection of bremsstrahlung γ photons and the functional extensibility of the method were discussed in this work.