Syphilis susceptibility factors atlas: A wide-angled Mendelian randomization study.

OBJECTIVE: The pathogenic mechanisms of syphilis and the host defense mechanisms against syphilis remain poorly understood. Exploration of the susceptibility factors of syphilis may provide crucial clues for unraveling its underlying mechanisms. METHODS: A two-sample Mendelian Randomization framework was utilized, and the inverse-variance weighted method was used as the main analysis. All data was sourced from Genome-wide association studies datasets from 2015 to 2022 in Europe, and all participants were of European descent. Only summary-level statistics were used. Sensitivity analyses were conducted to evaluate the heterogeneity and pleiotropy of the datasets. RESULTS: Our study established 18 exposure factors (12 risk factors and 6 protective factors) for syphilis susceptibility. Twelve factors encompassing body mass index, waist circumference, darker natural skin, cooked vegetable intake, processed meat intake, diabetes mellitus, glucose regulation disorders, gout, autoimmune diseases, rheumatoid arthritis, diverticulitis, and longer menstrual cycles were found to increase susceptibility to syphilis. In contrast, 6 factors including easier skin tanning, blonde natural hair color, irritability, higher neuroticism scores, extended sleep duration, and delayed age at first sexual intercourse were connected to a reduced risk of syphilis infection (all P < 0.05). CONCLUSIONS: This study identified 18 influencing factors of syphilis susceptibility. These findings offered novel insights for further probing into the underlying pathogenic mechanisms of syphilis and underscored the importance of multifaceted prevention strategies against syphilis.

Novel Dimeric Architecture of an IFN-γ-Related Cytokine Provides Insights into Subfunctionalization of Type II IFNs in Teleost Fish.

Gene duplication leads to subfunctionalization of paralogs. In mammals, IFN-γ is the sole member of the type II IFN family and binds to a receptor complex consisting of IFN-γR1 and IFN-γR2. In teleost fish, IFN-γ and its receptors have been duplicated due to the teleost-specific whole-genome duplication event. In this study, the functions of an IFN-γ-related (IFN-γrel) cytokine were found to be partially retained relative to IFN-γ in grass carp (Ctenopharyngodon idella [CiIFN-γrel]). CiIFN-γrel upregulated the expression of proinflammatory genes but had lost the ability to activate genes involved in Th1 response. The results suggest that CiIFN-γrel could have been subfunctionalized from CiIFN-γ. Moreover, CiIFN-γrel induced STAT1 phosphorylation via interaction with duplicated homologs of IFN-γR1 (cytokine receptor family B [CRFB] 17 and CRFB13). Strikingly, CiIFN-γrel did not bind to the IFN-γR2 homolog (CRFB6). To gain insight into the subfunctionalization, the crystal structure of CiIFN-γrel was solved at 2.26 Å, revealing that it forms a homodimer that is connected by two pairs of disulfide bonds. Due to the spatial positions of helix A, loop AB, and helix B, CiIFN-γrel displays a unique topology that requires elements from two identical monomers to form a unit that is similar to IFN-γ. Further, mutagenesis analyses identified key residues interacting with CiIFN-γrel receptors and those required for the biological functions. Our study can help understand the subfunctionalization of duplicated IFN-γ paralogs in fish.

Phylogeny and expression of ADAM10 and ADAM17 homologs in lamprey.

The ADAMs (a disintegrin and metalloproteinase) play regulatory roles in cell adhesion, migration and proteolysis. To explore the origin and evolution of ADAMs, this study identified the homologs of adam10 and adam17 in Lampetra morii and Lampetra japonica. Sequence analysis revealed that they share the same genomic structures with their counterparts in jawed vertebrates. The putative proteins possess conserved motifs, including a furin cut site (RXXR) for precursor processing, an enzyme catalytic motif (HEXGEHXXGXXH) for hydrolysis, and a Ca2+-binding motif (CGNXXXEXGEXCD) for stabilizing protein structure. In addition, a substrate recognition domain is present at the membrane-proximal region of lamprey ADAM17. The cytoplasmic region of lamprey ADAM10 contains a potential threonine phosphorylation site which has been shown to be activated by protein kinase C (PKC) in mammals. Both the adam10 and adam17 genes were constitutively expressed in the brain, kidney, and gills and were differentially regulated in the primary blood leukocytes by lipopolysaccharide (LPS) and pokeweed mitogen (PWM). Adam10 was induced by LPS but not PWM; conversely, adam17 was induced by PWM but not LPS. Taken together, our results suggest that the activation pathways and functions of ADAM10 and ADAM17 are conserved in agnathans.

The small RNA STnc1480 contributes to the regulation of biofilm formation and pathogenicity in Salmonella typhimurium.

Salmonella Typhimurium (STM) is one of the most important food-borne bacteria that seriously harms livestock and human beings, which is capable of regulating the expression of its own genes in a variety of ways to adapt to a wide variety of adverse environmental stresses. To understand the regulatory roles of sRNA STnc1480 on the capability of STM, the STnc1480 gene-deficient strain △STnc1480 and its complement strain △STnc1480/STnc1480 were generated, and the impacts of STnc1480 gene deficiency on the capability of responding to different environmental stresses, biofilm(BF)formation and pathogenicity were analyzed, respectively. Then the target genes that were regulated by STnc1480 were also analyzed and explored. Compared with parent and complement strains, the deficiency of the STnc1480 gene significantly reduced the BF formation. Moreover, the capacities of adhesion and invasiveness of the △STnc1480 strain to macrophages were also significantly reduced, while the LD50 in mice was significantly increased. The bacterial loads in liver and spleen were significantly reduced, and the pathological damage was alleviated. It was confirmed that the STnc1480 could be complementary to the 5'-UTR (-52 to -71 bases) region of lpfA mRNA. The bacterial dual-plasmid reporting system confirmed that STnc1480 was capable of interacting with the mRNA of the lpfA gene, suggesting that STnc1480 can regulate the 5'-UTR of the lpfA mRNA at post-transcription level to reduce the expression of the bacterial fimbria, thus reducing the BF formation and pathogenicity of STM.

Functional characterization of an interleukin 20 like homologue in grass carp Ctenopharyngodon idella.

IL-20 is a pleiotropic cytokine that belongs to the IL-10 family and plays an important biological role in tissue homeostasis and regulation of host immune defenses. IL-20 homologues have recently been discovered in fish, but their functions have not been studied. In this study, an IL-20 like (IL-20L) cytokine was cloned in grass carp (Ctenopharyngodon idella) and its bioactivities were investigated. Expression analysis showed that the CiIL-20L gene was constitutively expressed in tissues with the highest expression detected in the head kidney. It was upregulated in the head kidney after infection with Flavobactrium columnare (F. cloumnare) and grass carp reovirus II (GCRV II). The recombinant CiIL-20L produced in E. coli cells was shown to be effective in inducing the expression of Th cytokine genes (IFN-γ, IL-4/13A, IL-4/13B and IL-10), macrophage marker genes (arginase 2, IRF4, KLF4 and SOCS3) and inflammatory genes (IL-1ß, IL-6, IL-8 and TNFα) in the head kidney leukocytes when stimulated at 12 h. Long term culture (6 days) of head kidney macrophages in the presence of CiIL-20L leads to high expression of IRF4, TGFß1 and arginase 2. Our data suggest that IL-20 may play regulatory roles in promoting Th responses, macrophage differentiation and inflammation.

A chemiluminescence immunoassay for the detection of NT-proBNP.

BACKGROUND: The aim of the study was to assess the analytical performance of the HISCL NT-proBNP assay, a newly developed chemiluminescence immunoassay, for the detection of NT-proBNP. METHODS: The within-run and total imprecision of the NT-proBNP assay were determined with HISCL cardiac marker controls. The linear ranges of the NT-proBNP assays were evaluated based on the CLSI EP6-A document using selected serum samples. Two hundred serum samples were evaluated to compare the HISCL NT-proBNP and Elecsys NT-proBNP assays. Five additional high NT-proBNP concentrations serum samples were evaluated to assess if there was high-dose hook effect in the HISCL NT-proBNP assay. RESULTS: The total and within-run imprecision values of the HISCL NT-proBNP assay were 5.85%, 0.81%, 2.56% and 0.54% and 6.07%, 0.73%, 2.61% and 0.59% at 6.1, 129.83, 3732.84and39737.33 pg/ml, respectively. The assay was verified to be linear for NT-proBNP levels ranging between 6.1 and 39737.33 pg/ml. The assay comparison showed that HISCL NT-proBNP = 0.9803 × Elecsys NT-proBNP -4.383. The sensitivity of HISCL NT-proBNP was 87.23%, and the specificity was 85.61%. The AUC of HISCL NT-proBNP (0.90 (95% CI, 0.86-0.93)) did not differ from that of Elecsys NT-proBNP(0.89 (95% CI, 0.85-0.93)) (P = 0.638). The results of five high NT-proBNP concentrations samples (44448, 54206, 55634, 55728 and 109406 pg/ml, measured with the Elecsys NT-proBNP assay) tested with HISCL NT-proBNP assay were all displayed with ">40000 pg/ml". CONCLUSIONS: The HISCL NT-proBNP chemiluminescence immunoassay showed good analytical and diagnostic performance for the detection of NT-proBNP and could be used in routine clinical practice.

Comparison of electrolyte and glucose levels measured by a blood gas analyzer and an automated biochemistry analyzer among hospitalized patients.

BACKGROUND: Blood gas analyzers are capable of delivering results on electrolytes and metabolites within a few minutes and facilitate clinical decision-making. However, whether the results can be used interchangeably with values measured by chemistry analyzers remains controversial. Blood gas analyzers are capable of delivering results on electrolytes and metabolites within a few minutes and facilitate clinical decision-making. However, whether the results can be used interchangeably with values measured by chemistry analyzers remains controversial. METHODS: In total, arterial and matched venous blood samples were collected from 200 hospitalized patients. Arterial blood samples were evaluated using a RAPIDPOINT 500 to test electrolyte and glucose levels, then the samples were centrifuged and the same parameters were measured with an AU5800. Venous blood samples were processed and tested in accordance with standard operation procedures. Data were compared by using a paired t test, the agreement between the two analyzers was evaluated by using the Bland-Altman test, and sensitivity and specificity were calculated. RESULTS: Paired t tests showed that all parameters tested were significantly different between the two analyzers except chloride. The biases calculated indicated that blood gas analyzers tend to underestimate the parameters, and the linear regression showed a strong correlation between the two analyzers. The sensitivity, specificity and kappa values demonstrated that the diagnostic performance of blood gas analyzers is not satisfactory. CONCLUSION: The significant reduction in parameter estimation and diagnostic performance we observed suggested that clinicians should interpret results from blood gas analyzers more cautiously. The reference interval of blood gas analyzers should be adjusted accordingly, given that values are underestimated.

Effects of different mulching and fertilization on phosphorus transformation in upland farmland.

In the present study, the impact of different soil surface mulching, fertilization on phosphorus mineralization and bio-availability of spring maize at various growth stages and soil layers (0-20 and 20-40 cm soil layer) were evaluated. The results indicated that the contents of total P and Olsen-Phosphorus (Olsen-P) in the soils of 0-20 cm soil layer were significantly higher than those in the 20-40 cm soil layer at different stages. The addition of organic fertilizer significantly increased the soil total P and Olsen-P content in the 0-20 cm soil layer. The different surface mulching, no mulching (NM), gravel mulching (GM) and film mulching (FM) were significantly affected by the content of Olsen-P in both soil layers during the critical growth period of spring maize. The Ca10-P contents in both soil layers were the maximum in terms of the inorganic phosphorus content in soils with different surface mulching and different fertilization. Surface mulching significantly affected the transformation of inorganic phosphorus in different soil layers of dry-land farmland, and accelerated the increase of Ca2-P content (first phosphorus source) in 0-20 cm soil layer by GM and FM. In addition, phosphorus combined with inorganic nitrogen fertilizer increased Ca8-P (second Olsen-P source) to a certain extent, and reduced the relative content of Ca2-P (first phosphorus source). Compared with phosphate (P), nitrogen and phosphorus (NP) treatments, manure and nitrogen and phosphorus (MNP) treatments increased the contents of Ca2-P (first phosphorus source) and Ca8-P (second effective phosphorus source), while it reduced the insoluble phosphorus source (O-P) content.

Origin of Nontreponemal Antibodies During Treponema pallidum Infection: Evidence From a Rabbit Model.

The origin of nontreponemal antibodies during syphilis infection is hotly debated. Here, we analyzed the immune response in rabbits immunized with various antigens. Inactivated treponemes elicited the production of low-titer nontreponemal antibodies in some rabbits. Cardiolipin combined with bovine serum albumin also induced anticardiolipin antibody production. These findings indicate that Treponema pallidum contained a cardiolipin antigen with weak immunogenicity. However, active T. pallidum induced higher nontreponemal antibody production with strong immunogenicity at an earlier time point, and the antibody titer was consecutive, suggesting the high nontreponemal antibody titer resulted from the combined effects of both the T. pallidum cardiolipin antigen and the damaged host-cell cardiolipin antigen during syphilis infection, the latter of which plays a major role in the induction of nontreponemal antibody production. Our study provides direct animal evidence of the origin of nontreponemal antibodies during T. pallidum infection.

Treponema pallidum promotes macrophage polarization and activates the NLRP3 inflammasome pathway to induce interleukin-1ß production.

BACKGROUND: The involvement of inflammasome activation and macrophage polarization during the process of syphilis infection remains unknown. In this study, A series of experiments were performed using human macrophages to research the role of NLRP3 inflammasome regulation in interleukin (IL)-1ß production and its influence on macrophage polarization triggered by T. pallidum. RESULTS: The results showed that in M0 macrophages treated with T. pallidum, the M1-associated markers inducible nitric oxide synthase (iNOS), IL-1ß and TNF-α were upregulated, and the M2-associated markers CD206 and IL-10 were downregulated. In addition, we observed NLRP3 inflammasome activation and IL-1ß secretion in T. pallidum-treated macrophages, and the observed production of IL-1ß occurred in a dose- and time-dependent manner. Moreover, the secretion of IL-1ß by macrophages after T. pallidum treatment was notably reduced by anti-NLRP3 siRNA and caspase-1 inhibitor treatment. NAC, KCl, and CA074-ME treatment also suppressed IL-1ß release from T. pallidum-treated macrophages. CONCLUSIONS: These findings showed that T. pallidum induces M0 macrophages to undergo M1 macrophage polarization and elevate IL-1ß secretion through NLRP3. Moreover, the process of NLRP3 inflammasome activation and IL-1ß production in macrophages in response to T. pallidum infection involves K+ efflux, mitochondrial ROS production and cathepsin release. This study provides a new insight into the innate immune response to T. pallidum infection.

Assessing effects of different processing procedures on the yield of Treponema pallidum DNA from blood.

In this work, we employed real-time PCR analysis targeting tp0574 to investigate the effects of different processing procedures on the yield of T. pallidum DNA from blood to improve assay sensitivity. The T. pallidum DNA yields following red blood cell lysis pretreatment were 40.4 times greater from whole blood and 32.4 times greater from residual hematocytes than yields without pretreatment. For the simulated whole-blood experiments, the T. pallidum DNA yields from the lower layer were 2.8, 4.6, 7.3, 12.6, 15.24, 16.7, 65.1 and 73.1 times those from the upper layer following centrifugation at 500×, 1000×, 2000×, 4000×, 5000×, 7000×, 10,000× and 20,000 × g, respectively. However, the T. pallidum DNA yields from blood clots were only 1.0% at different centrifugal forces. The experiment with infected rabbit blood showed results similar to those mentioned above. In addition, sample processing time (within 48 h) and storage temperature (4 °C and 25 °C) did not affect T. pallidum DNA extraction efficiency. The T. pallidum DNA yield can be significantly improved by red blood cell lysis pretreatment and appropriate centrifugation. Furthermore, the T. pallidum DNA extraction yield is greater from whole blood or residual hematocytes from anti-coagulated blood than from plasma, serum or blood clots.

Molecular characterization of three toll-like receptors (TLR21, TLR22, and TLR25) from a primitive ray-finned fish Dabry's sturgeon (Acipenser dabryanus).

Dabry's sturgeon (Acipenser dabryanus) is a useful model for the study of fish evolution, as it is one of the most primitive actinopterygian species. However, studies of the immune system of this fish are limited. Here, we identified three toll-like receptors (adaTLR21, adaTLR22, and adaTLR25) from Dabry's sturgeon. The three sturgeon TLRs had characteristic TLR features, including a signal peptide, several leucine rich repeat (LRR) domains, a transmembrane domain, and a Toll/interleukin-1 receptor (TIR) domain. Although the predicted amino acid sequences encoded by the sturgeon adaTLR21, adaTLR22, and adaTLR25 had somewhat low levels of sequence identity and similarity with TLRs from other fish species, the three sturgeon TLRs fell in well-supported clades with other teleost TLRs in our neighbor-joining phylogenetic tree. Real-time quantitative PCR showed that the three sturgeon TLRs were ubiquitously expressed in all examined tissues from healthy adult sturgeon, but that their expression patterns varied greatly among the different tissues. The three sturgeon TLRs were also expressed across all embryonic developmental stages that were examined, but their expression levels differed between developmental stages. All three TLRs were upregulated in head-kidney primary leucocytes following lipopolysaccharide (LPS) and polyinosinic: polycytidylic acid (polyI:C) stimulation. To the best of our knowledge, this is the first characterization of these three TLRs in Darby's sturgeon. Our results provide a framework for further studies of TLR ligand specificity and signaling pathways in sturgeon, and increase our understanding of the functional evolution of TLRs in vertebrates.

Development of tissue inflammation accompanied by NLRP3 inflammasome activation in rabbits infected with Treponema pallidum strain Nichols.

BACKGROUND: The inflammasome responses in Treponema pallidum infection have been poorly understood to date. This study aimed to investigate the expression of the nucleotide-binding leucine-rich receptor protein 3 (NLRP3) inflammasome in the development of tissue inflammation in rabbits infected with T. pallidum. METHODS: Forty-five rabbits were randomly assigned to a blank group or an infection group, and the latter was divided into no benzathine penicillin G (BPG) and BPG treatment subgroups. Rabbits in the infection group were injected intradermally with 0.1 mL of a 107/mL T. pallidum suspension at 10 marked sites along the back, and the blank group was treated with normal saline. The BPG treatment subgroup received 200,000 U of BPG administered intramuscularly twice, at 14 d and 21 d post-infection. The development of lesions was observed, and biopsies of the injection site and various organs, including the kidney, liver, spleen, lung, and testis, were obtained for NLRP3, caspase-1, and interleukin-1ß (IL-1ß) mRNA analysis during infection. Blood was also collected for the determination of IL-1ß concentration. RESULTS: Rabbits infected with T. pallidum (both the BPG treatment and no BPG treatment subgroups), exhibited NLRP3 inflammasome activation and IL-1ß secretion in cutaneous lesions, showing a trend in elevation to decline; NLRP3 mRNA expression reached a peak at 18 d in the BPG treatment subgroup and 21 d in the no BPG treatment subgroup and returned to "normal" levels [vs. the blank group (P > 0.05)] at 42 d post-infection. The trend was similar to the change in cutaneous lesions in the infected rabbits, which reached a peak at 16 d in the BPG treatment subgroup and 18 d in the no BPG treatment subgroup. NLRP3, caspase-1, and IL-1ß mRNA expression levels were slightly different in different organs. NLRP3 inflammasome activation was also observed in the kidney, liver, lung, spleen and testis. IL-1ß expression was observed in the kidney, liver, lung and spleen; however, there was no detectable level of IL-1ß in the testes of the infected rabbits. CONCLUSIONS: This study established a clear link between NLRP3 inflammasome activation and the development of tissue inflammation in rabbits infected with T. pallidum. BPG therapy imperceptibly adjusted syphilitic inflammation.

Comparison of Clinical and Laboratory Characteristics of General Paresis and Non-Neurosyphilis Dementia.

BACKGROUND: The differential diagnosis of general paresis (GP) and non-neurosyphilis (NS) dementia is not clearly defined. The present study examined the differences in clinical and laboratory features of GP and non-NS dementia. MATERIALS AND METHODS: We retrospectively examined clinical and laboratory features of 85 GP patients and 196 non-NS dementia patients. Data were collected from Zhongshan Hospital between June 2005 and June 2014. RESULTS: The GP group had a higher percentage of males (83.53%, 71/85) and younger median age ([52 [interquartile range 47.0-61.0] vs. 76 [68.3-82.0] years) than the non-NS dementia group. GP have higher Mini-Mental State Examination (MMSE; Z = -5.809; p = 0.000) than non-NS dementia. Distribution of CDR scores were significantly higher in the non-NS group than GP group (χ2 = 29.153; p = 0.000). The laboratory findings showed significantly different total cholesterol (CH), low-density lipoprotein CH and homocysteine levels between the 2 groups. Serologic testing for syphilis revealed that the GP group had higher seropositive rapid plasma reagin (RPR) and Treponema pallidum particle agglutination (TPPA) rates than the non-NS dementia group (96.47% [82/85] vs. 0.51% [1/196], Z = -2.663, p = 0.008; 100% [85/85] vs. 1.02% [2/196], Z = -2.663, p = 0.008). Interestingly, cerebrospinal fluid (CSF) biochemical indices, including pleocytosis rates, increased protein levels, and positive RPR and TPPA rates in the GP group were higher than that in the non-NS dementia group. CONCLUSIONS: Based on these preliminary data, patients with clinically evident symptoms of dementia, especially middle-aged males, should undergo blood tests for syphilis. All patients with positive serology results should undergo CSF examinations to diagnose GP dementia before further pharmaceutical and behavioral interventions.

Evaluation of the boson chemiluminescence immunoassay as a first-line screening test in the ECDC algorithm for syphilis serodiagnosis in a population with a high prevalence of syphilis.

We developed a new Boson chemiluminescence immunoassay (CIA) and evaluated its application with cross-sectional analyses. Our results indicated that the Boson CIA demonstrated strong discriminatory power in diagnosing syphilis and that it can be used as a first-line screening test for syphilis serodiagnosis using the European Centre for Disease Prevention and Control algorithm or as a confirmatory test when combined with a patient's clinical history.

Highly BBB-permeable nanomedicine reverses neuroapoptosis and neuroinflammation to treat Alzheimer's disease.

The prevalence of Alzheimer's disease (AD) is increasing globally due to population aging. However, effective clinical treatment strategies for AD still remain elusive. The mechanisms underlying AD onset and the interplay between its pathological factors have so far been unclear. Evidence indicates that AD progression is ultimately driven by neuronal loss, which in turn is caused by neuroapoptosis and neuroinflammation. Therefore, the inhibition of neuroapoptosis and neuroinflammation could be a useful anti-AD strategy. Nonetheless, the delivery of active drug agents into the brain parenchyma is hindered by the blood-brain barrier (BBB). To address this challenge, we fabricated a black phosphorus nanosheet (BP)-based methylene blue (MB) delivery system (BP-MB) for AD therapy. After confirming the successful preparation of BP-MB, we proved that its BBB-crossing ability was enhanced under near-infrared light irradiation. In vitro pharmacodynamics analysis revealed that BP and MB could synergistically scavenge excessive reactive oxygen species (ROS) in okadaic acid (OA)-treated PC12 cells and lipopolysaccharide (LPS)-treated BV2 cells, thus efficiently reversing neuroapoptosis and neuroinflammation. To study in vivo pharmacodynamics, we established a mouse model of AD mice, and behavioral tests confirmed that BP-MB treatment could successfully improve cognitive function in these animals. Notably, the results of pathological evaluation were consistent with those of the in vitro assays. The findings demonstrated that BP-MB could scavenge excessive ROS and inhibit Tau hyperphosphorylation, thereby alleviating downstream neuroapoptosis and regulating the polarization of microglia from the pro-inflammatory M1 phenotype to the anti-inflammatory M2 phenotype. Overall, this study highlights the therapeutic potential of a smart nanomedicine with the capability of reversing neuroapoptosis and neuroinflammation for AD treatment.

Unveiling biochar potential to promote safe crop production in toxic metal(loid) contaminated soil: A meta-analysis.

Biochar application emerges as a promising and sustainable solution for the remediation of soils contaminated with potentially toxic metal (loid)s (PTMs), yet its potential to reduce PTM accumulation in crops remains to be fully elucidated. In our study, a hierarchical meta-analysis based on 276 research articles was conducted to quantify the effects of biochar application on crop growth and PTM accumulation. Meanwhile, a machine learning approach was developed to identify the major contributing features. Our findings revealed that biochar application significantly enhanced crop growth, and reduced PTM concentrations in crop tissues, showing a decrease trend of grains (36.1%, 33.6-38.6%) > shoots (31.1%, 29.3-32.8%) > roots (27.5%, 25.7-29.2%). Furthermore, biochar modifications were found to amplify its remediation potential in PTM-contaminated soils. Biochar application was observed to provide favorable conditions for reducing PTM uptake by crops, primarily through decreasing available PTM concentrations and improving overall soil quality. Employing machine learning techniques, we identified biochar properties, such as surface area and C content as a key factor in decreasing PTM bioavailability in soil-crop systems. Furthermore, our study indicated that biochar application could reduce probabilistic health risks associated with of the presence of PTMs in crop grains, thereby contributing to human health protection. These findings highlighted the essential role of biochar in remediating PTM-contaminated lands and offered guidelines for enhancing safe crop production.

Synergistic enhancement of plant growth and cadmium stress defense by Azospirillum brasilense and plant heme: Modulating the growth-defense relationship.

Plant growth-promoting rhizobacteria (PGPR) play important roles in plant growth and defense under heavy metal (HM) stress. The direct integration of microbial and plant signals is key to the regulation of plant growth and HM stress defense, but the underlying mechanisms are still limited. Herein, we reveal a novel mechanism by which PGPR regulates plant growth-regulating substances in plant tissues and coordinates plant growth and defense in pak choi under cadmium (Cd) stress. This might be an efficient strategy and an extension of the mechanism by which plant-microbe interactions improve plant stress resistance. Azospirillum brasilense and heme synergistically reduced the shoot Cd content and promoted the growth of pak choi. The interaction between abscisic acid of microbial origin and heme improved Cd stress tolerance through enhancing Cd accumulation in the root cell wall. The interaction between A. brasilense and heme induced the growth-defense shift in plants under Cd stress. Plants sacrifice growth to enhance Cd stress defense, which then transforms into a dual promotion of both growth and defense. This study deepens our understanding of plant-microbe interactions and provides a novel strategy to improve plant growth and defense under HM stress, ensuring future food production and security.

Inoculation with Bacillus thuringiensis reduces uptake and translocation of Pb/Cd in soil-wheat system: A life cycle study.

Microbial inoculation is an important strategy to reduce the supply of heavy metals (HMs) in soil-crop systems. However, the mechanisms of microbial inoculation for the availability of HMs in soil and their accumulation/transfer in crops remain unclear. Here, the inhibitory effect of inoculation with Bacillus thuringiensis on the migration and accumulation of Pb/Cd in the soil-wheat system during the whole growth period was investigated by pot experiments. The results showed that inoculation with Bacillus thuringiensis increased soil pH and available nutrients (including carbon, nitrogen, and phosphorus), and enhanced the activities of nutrient-acquiring enzymes. Dominance analysis showed that dissolved organic matter (DOM) is the key factor affecting the availability of HMs. The content of colored spectral clusters and humification characteristics of DOM were significantly improved by inoculation, which is conducive to reducing the availability of Pb/Cd, especially during the flowering stage, the decrease was 12.8 %. Inoculation decreased Pb/Cd accumulation in the shoot and the transfer from root to shoot, with the greatest decreases at the jointing and seedling stages (27.0-34.1 % and 6.9-11.8 %), respectively. At the maturity stage, inoculation reduced the Pb/Cd accumulation in grain (12.9-14.7 %) and human health risk (4.1-13.2 %). The results of Pearson correlation analysis showed that the availability of Pb/Cd was positively correlated with the humification of DOM. Least square path model analysis showed that Bacillus thuringiensis could significantly reduce Pb/Cd accumulation in the grain and human health risks by regulating DOM spectral characteristics, the availability of HMs in soil and metals accumulation/transport in wheat at different growth stages. This study revealed the inhibition mechanism of Bacillus thuringiensis on migration of Pb/Cd in a soil-wheat system from a viewpoint of a full life cycle, which offers a valuable reference for the in-situ remediation of HM-contaminated soil and the safe production of food crops in field.

Customized Intranasal Hydrogel Delivering Methylene Blue Ameliorates Cognitive Dysfunction against Alzheimer's Disease.

The accumulation of hyperphosphorylated tau protein aggregates is a key pathogenic event in Alzheimer's disease (AD) and induces mitochondrial dysfunction and reactive oxygen species overproduction. However, the treatment of AD remains challenging owning to the hindrance caused by the blood-brain barrier (BBB) and the complex pathology of AD. Nasal delivery represents an effective means of circumventing the BBB and delivering drugs to the brain. In this study, black phosphorus (BP) is used as a drug carrier, as well as an antioxidant, and loaded with a tau aggregation inhibitor, methylene blue (MB), to obtain BP-MB. For intranasal (IN) delivery, a thermosensitive hydrogel is fabricated by cross-linking carboxymethyl chitosan and aldehyde Pluronic F127 (F127-CHO) micelles. The BP-MB nanocomposite is incorporated into the hydrogel to obtain BP-MB@Gel. BP-MB@Gel could be injected intranasally, providing high nasal mucosal retention and controlled drug release. After IN administration, BP-MB is continuously released and delivered to the brain, exerting synergistic therapeutic effects by suppressing tau neuropathology, restoring mitochondrial function, and alleviating neuroinflammation, thus inducing cognitive improvements in mouse models of AD. These findings highlight a potential strategy for brain-targeted drug delivery in the management of the complex pathologies of AD.