Acidithiobacillus species mediated mineral weathering promotes lead immobilization in ferric-silica microstructures at sulfidic tailings.

Immobilization and stabilization of heavy metals (HMs) in sulfidic and metallic tailings are critical to long-term pollution control and sustainable ecological rehabilitation. This study aims to unravel immobilization mechanisms of Pb (Ⅱ) in the neoformed hardpan structure resulting from Acidithiobacillus spp. accelerated bioweathering of sulfides in the presence of silicates. It was found that the bioweathered mineral composite exhibited an elevated Pb (Ⅱ) adsorption capacity compared to that of natural weathered mineral composite. A suit of microspectroscopic techniques such as synchrotron-based X-ray Absorption Spectroscopy (XAS), X-ray Photoelectron Spectroscopy (XPS), Fourier Transform Infrared Spectroscopy (FTIR) and Field-Emission Scanning Electron Microscope (FE-SEM) indicated that secondary Fe-bearing minerals, functional groups, and surface properties in the neoformed hardpan were key factors contributing to Pb (Ⅱ) adsorption and immobilization in ferric-silica microstructures. The underlying mechanisms might involve surface adsorption-complexation, dissolution-precipitation, electrostatic attraction, and ion exchange. Microbial communities within the muscovite groups undergoing bioweathering processes demonstrated distinctive survival strategies and community composition under the prevailing geochemical conditions. This proof of concept regarding Pb (Ⅱ) immobilization in microbial transformed mineral composite would provide the basis for scaling up trials for developing field-feasible methodology to management HMs pollution in sulfidic and metallic tailings in near future.

Exosome-mimetic vesicles derived from fibroblasts carrying matrine for wound healing.

Background: Chronic skin wounds are a leading cause of hospital admissions and reduced life expectancy among older people and individuals with diabetes. Delayed wound healing is often attributed to a series of cellular abnormalities. Matrine, a well-studied component found in Sophora flavescens, is recognized for its anti-inflammatory effects. However, its impact on wound healing still remains uncertain. This study aims to explore the potential of matrine in promoting wound healing. Methods: In this study, we utilized gradient extrusion to produce fibroblast-derived exosome-mimetic vesicles as carriers for matrine (MHEM). MHEM were characterized using transmission electron microscopy and dynamic light scattering analysis. The therapeutic effect of MHEM in wound healing was explored in vitro and in vivo. Results: Both matrine and MHEM enhanced the cellular activity as well as the migration of fibroblasts and keratinocytes. The potent anti-inflammatory effect of matrine diluted the inflammatory response in the vicinity of wounds. Furthermore, MHEM worked together to promote angiogenesis and the expression of transforming growth factor ß and collagen I. MHEM contained growth factors of fibroblasts that regulated the functions of fibroblasts, keratinocytes and monocytes, which synergistically promoted wound healing with the anti-inflammatory effect of matrine. Conclusions: MHEM showed enhanced therapeutic efficacy in the inflammatory microenvironment, for new tissue formation and angiogenesis of wound healing.

The epidermal lipid-microbiome loop and immunity: Important players in atopic dermatitis.

BACKGROUND: The promotion of epidermal barrier dysfunction is attributed to abnormalities in the lipid-microbiome positive feedback loop which significantly influences the imbalance of the epithelial immune microenvironment (EIME) in atopic dermatitis (AD). This imbalance encompasses impaired lamellar membrane integrity, heightened exposure to epidermal pathogens, and the regulation of innate and adaptive immunity. The lipid-microbiome loop is substantially influenced by intense adaptive immunity which is triggered by abnormal loop activity and affects the loop's integrity through the induction of atypical lipid composition and responses to dysregulated epidermal microbes. Immune responses participate in lipid abnormalities within the EIME by downregulating barrier gene expression and are further cascade-amplified by microbial dysregulation which is instigated by barrier impairment. AIM OF REVIEW: This review examines the relationship between abnormal lipid composition, microbiome disturbances, and immune responses in AD while progressively substantiating the crosstalk mechanism among these factors. Based on this analysis, the "lipid-microbiome" positive feedback loop, regulated by immune responses, is proposed. KEY SCIENTIFIC CONCEPTS OF REVIEW: The review delves into the impact of adaptive immune responses that regulate the EIME, driving AD, and investigates potential mechanisms by which lipid supplementation and probiotics may alleviate AD through the up-regulation of the epidermal barrier and modulation of immune signaling. This exploration offers support for targeting the EIME to attenuate AD.

Aptamer-bivalent-cholesterol-mediated proximity entropy-driven exosomal protein reporter for tumor diagnosis.

Exosomal proteins from the parental cells are considered to be promising biomarker sets for precise tumor diagnostics and monitoring. However, the accurate quantitative analysis of low-abundance exosomal proteins remains challenging due to the heterogeneity of clinical samples. Here, we standardized the exosomal concentration with a fluorogenic membrane probe and developed an aptamer-bivalent-cholesterol-mediated Proximity Entropy-driven Exosomal Protein Reporter (PEEPR). The proposed PEEPR enables the in-situ analysis of multiple exosomal proteins by integrating bivalent cholesterol anchor (exosomal lipid bilayer) and aptamer (exosomal proteins) with a proximity entropy-driven circuit. Based on this strategy, we successfully achieved detection limits of 3.9 pg/mL exosomal GPC-3 and 3.4 pg/mL exosomal PD-L1. Notably, the standardization of exosome concentrations is designed to avoid errors due to biological heterogeneity. The results showed that evaluating the levels of exosomal GPC-3 and PD-L1 in clinical samples via this strategy could accurately differentiate healthy individuals, hepatitis B patients, and hepatocellular carcinoma patients. In summary, PEEPR is a promising clinical diagnostic strategy for the quantitative analysis of a variety of tumor-associated exosomal proteins for the precise diagnosis and personalized treatment monitoring of tumors.

Development and validation of a near-infrared spectroscopy model for the prediction of muscle protein in Chinese native chickens.

This study investigated the ability of the near-infrared spectroscopy (NIRS) model to predict the protein of freeze-dried muscle samples in Chinese native chickens and to determine the accuracy of the models for other native chicken breeds. Spectral pretreatment, wavelength selection, and outlier sample elimination were used to optimize the calibration models. The results showed that the best model was obtained by using a combination of standard normal variable transformation and gap-segment first-derivative pretreatment spectra after removing 48 outliers in the wavelength range of 1,439 to 1,900 nm, with coefficient of determination for the calibration (R2C) of 0.95, standard error of cross-validation (SECV) of 1.18, coefficient of determination for the prediction (R2P) of 0.95, the ratio of the standard deviation of the validation to the standard deviation of the calibration (RPDP) of 4.62. The findings indicated that NIRS can be used to predict the protein of freeze-dried muscle in Chinese native chickens.

A novel dual-function fluorescent probe for the detection of cysteine and its applications in vitro.

A fluorescent probe of both colorimetric and ratiometric type for highly selective and sensitive detection of Cys (cysteine) is very important in biological analysis. In this work, a new colorimetric and ratiometric fluorescent probe ((E)-2-(2-(5-(4-(acryloyloxy)phenyl)furan-2-yl)vinyl)-3-methylbenzo[d]thiazol-3-ium iodide, LP-1) was designed and synthesized for the detection of Cys. The reaction mechanism of LP-1 toward Cys involves a conjugate addition reaction between Cys and the α,ß-unsaturated carbonyl group, leading to the formation of an intermediate thioether, followed by intramolecular cyclization to produce the desired compounds LP-1-OH. At this point, the ICT process is activated, significantly increasing the fluorescence intensity of the molecules. Meanwhile, LP-1 is highly selective and sensitive to Cys identification under optimized experimental conditions. LP-1 shows a good linear relationship in the range of Cys concentration from 0.40 µM to 40 µM (R2 = 0.9942) and the limit of detection (LOD) of Cys is 0.19 µM. In addition, we have developed a simple, portable and low-cost smartphone-based high-sensitivity Cys detection method based on naked eye obvious color detection. LP-1 also has low cell toxicity and can be successfully used for biological imaging of Cys, suggesting that it is a promising biological application tool for Cys detection.

Isobavachalcone, a natural sirtuin 2 inhibitor, exhibits anti-triple-negative breast cancer efficacy in vitro and in vivo.

Triple-negative breast cancer (TNBC) is the most aggressive and lethal clinical subtype and lacks effective targeted therapies at present. Isobavachalcone (IBC), the main active component of Psoralea corylifolia L., has potential anticancer effects. Herein, we identified IBC as a natural sirtuin 2 (SIRT2) inhibitor and characterized the potential mechanisms underlying the inhibition of TNBC. Molecular dynamics analysis, enzyme activity assay, and cellular thermal shift assay were performed to evaluate the combination of IBC and SIRT2. The therapeutic effects, mechanism, and safety of IBC were analyzed in vitro and in vivo using cellular and xenograft models. IBC effectively inhibited SIRT2 enzyme activity with an IC50 value of 0.84 ± 0.22 µM by forming hydrogen bonds with VAL233 and ALA135 within its catalytic domain. In the cellular environment, IBC bound to and stabilized SIRT2, consequently inhibiting cellular proliferation and migration, and inducing apoptosis and cell cycle arrest by disrupting the SIRT2/α-tubulin interaction and inhibiting the downstream Snail/MMP and STAT3/c-Myc pathways. In the in vivo model, 30 mg/kg IBC markedly inhibited tumor growth by targeting the SIRT2/α-tubulin interaction. Furthermore, IBC exerted its effects by inducing apoptosis in tumor tissues and was well-tolerated. IBC alleviated TNBC by targeting SIRT2 and triggering the reactive oxygen species ROS/ß-catenin/CDK2 axis. It is a promising natural lead compound for future development of SIRT2-targeting drugs.

Adoptive cell therapy for solid tumors beyond CAR-T: Current challenges and emerging therapeutic advances.

Adoptive cellular immunotherapy using immune cells expressing chimeric antigen receptors (CARs) is a highly specific anti-tumor immunotherapy that has shown promise in the treatment of hematological malignancies. However, there has been a slow progress toward the treatment of solid tumors owing to the complex tumor microenvironment that affects the localization and killing ability of the CAR cells. Solid tumors with a strong immunosuppressive microenvironment and complex vascular system are unaffected by CAR cell infiltration and attack. To improve their efficacy toward solid tumors, CAR cells have been modified and upgraded by "decorating" and "pruning". This review focuses on the structure and function of CARs, the immune cells that can be engineered by CARs and the transformation strategies to overcome solid tumors, with a view to broadening ideas for the better application of CAR cell therapy for the treatment of solid tumors.

Age and dietary restriction modulate mitochondrial quality in quadriceps femoris muscle of male mice.

Dietary restriction (DR) is a potential intervention for ameliorating ageing-related damages. Mitochondrial quality control is the key mechanism for regulating cellular functions in skeletal muscle. This study aimed to explore the effect of age and DR on the homeostasis of mitochondrial quality control in skeletal muscle. To study the effect of age on mitochondrial homeostasis, young (3 months old) male C57BL/6J mice were fed ad libitum (AL) until 7 (Young), 14 (Middle), and 19 months (Aged) of age. For the DR intervention, 60% of AL intake was given to the mice at 3 months of age until they reached 19 months of age (16 months). The quadriceps femoris muscle was collected for further analysis. Significant changes in the skeletal muscle were noticed during the transition between middle age and the elderly stages. An accumulation of collagen was observed in the muscle after middle age. Compared with the Middle muscle, Aged muscle displayed a greater expression of VDAC, and lower expressions of mitochondrial dynamic proteins and OXPHOS proteins. The DR intervention attenuated collagen content and elongated the sarcomere length in the skeletal muscle during ageing. In addition, DR adjusted the abnormalities in mitochondrial morphology in the Aged muscle. DR downregulated VDAC expression, but upregulated OPA1 and DRP1 expressions. Taken together, greater pathological changes were noticed in the skeletal muscle during ageing, especially in the transition between middle age and the elderly, whereas early-onset DR attenuated the muscular ageing via normalising partial functions of mitochondria.

Targeting tumor-associated macrophages: Novel insights into immunotherapy of skin cancer.

BACKGROUND: The incidence of skin cancer is currently increasing, and conventional treatment options inadequately address the demands of disease management. Fortunately, the recent rapid advancement of immunotherapy, particularly immune checkpoint inhibitors (ICIs), has ushered in a new era for numerous cancer patients. However, the efficacy of immunotherapy remains suboptimal due to the impact of the tumor microenvironment (TME). Tumor-associated macrophages (TAMs), a major component of the TME, play crucial roles in tumor invasion, metastasis, angiogenesis, and immune evasion, significantly impacting tumor development. Consequently, TAMs have gained considerable attention in recent years, and their roles have been extensively studied in various tumors. However, the specific roles of TAMs and their regulatory mechanisms in skin cancer remain unclear. AIM OF REVIEW: This paper aims to elucidate the origin and classification of TAMs, investigate the interactions between TAMs and various immune cells, comprehensively understand the precise mechanisms by which TAMs contribute to the pathogenesis of different types of skin cancer, and finally discuss current strategies for targeting TAMs in the treatment of skin cancer. KEY SCIENTIFIC CONCEPTS OF OVERVIEW: With a specific emphasis on the interrelationship between TAMs and skin cancer, this paper posits that therapeutic modalities centered on TAMs hold promise in augmenting and harmonizing with prevailing clinical interventions for skin cancer, thereby charting a novel trajectory for advancing the landscape of immunotherapeutic approaches for skin cancer.

JAK1/JAK2 degraders based on PROTAC for topical treatment of atopic dermatitis.

Atopic dermatitis (AD) is a prevalent chronic inflammatory skin disease. The Janus kinase (JAK) has been identified as a target in AD, as it regulates specific inflammatory genes and adaptive immune responses. However, the efficacy of topically applied JAK inhibitors in AD is limited due to the unique structure of skin. We synthesized JAK1/JAK2 degraders (JAPT) based on protein degradation targeting chimeras (PROTACs) and prepared them into topical preparations. JAPT exploited the E3 ligase to mediate ubiquitination and degradation of JAK1/JAK2, offering a promising AD therapeutic approach with low frequency and dosage. In vitro investigations demonstrated that JAPT effectively inhibited the release of pro-inflammatory cytokines and reduced inflammation by promoting the degradation of JAK. In vivo studies further confirmed the efficacy of JAPT in degrading JAK1/JAK2, leading to a significant suppression of type I, II, and III adaptive immunity. Additionally, JAPT demonstrated a remarkable reduction in AD severity, as evidenced by improved skin lesion clearance and AD severity scores (SCORAD). Our study revealed the therapeutic potential of JAPT, surpassing conventional JAK inhibitors in the treatment of AD, which suggested that JAPT could be a promising topically applied anti-AD drug targeting the JAK-STAT signaling pathway.

Weight regain, but not weight loss exacerbates hepatic fibrosis during multiple weight cycling events in male mice.

PURPOSE: Weight cycling is a phenomenon characterized by fluctuating body weight that is commonly observed in individuals employing intentional weight loss methods. Despite its prevalence, the impact of weight cycling on health remains equivocal. The current investigation aimed to examine the effects of weight cycling on liver health. METHODS: The weight cycling model was established by switching the feeding method of mice between ad libitum (AL) and restricted intake (DR or 60% of AL) of the breeding diet to cause weight gain and weight loss, respectively. The weight cycling model comprised two and a half cycles, with one group terminating the experience during the weight-gain period (S-AL) and the other during the weight-loss period (S-DR). Liver tissue was collected to investigate morphology alterations, apoptosis, lipid metabolism, and mitochondrial homeostasis. RESULTS: The results demonstrated that the termination point of weight cycling affected body weight and hepatic steatosis. All parameters examined in the S-DR mice exhibited a comparable trend to those observed in the DR mice. Notably, S-AL mice showed a significant increase in lipid metabolism-related proteins in the liver compared to AL-fed mice, along with reduced lipid droplets. Moreover, hepatic apoptosis and fibrosis were exacerbated in the S-AL mice compared to AL mice, whereas mitochondrial fusion, biogenesis, and mitophagy were decreased in the S-AL mice. CONCLUSION: Weight cycling ending in weight gain exacerbated hepatic fibrosis, potentially by inducing apoptosis or disrupting mitochondrial homeostasis. Conversely, weight cycling ending in weight loss demonstrated beneficial effects on hepatic health.

Acidithiobacillus species drive the formation of ferric-silica cemented microstructure: Insights into early hardpan development for mine site rehabilitation.

Hardpan-based profiles naturally formed under semi-arid climatic conditions have substantial potential in rehabilitating sulfidic tailings, resulting from their aggregation microstructure regulated by Fe-Si cements. Nevertheless, eco-engineered approaches for accelerating the formation of complex cementation structure remain unclear. The present study aims to investigate the microbial functions of extremophiles on mineral dissolution, oxidation, and aggregation (cementation) through a microcosm experiment containing pyrites and polysilicates, of which are dominant components in typical sulfidic tailings. Microspectroscopic analysis revealed that pyrite was rapidly dissolved and massive microbial corrosion pits were displayed on pyrite surfaces. Synchrotron-based X-ray absorption spectroscopy demonstrated that approximately 30 % pyrites were oxidized to jarosite-like (ca. 14 %) and ferrihydrite-like minerals (ca. 16 %) in talc group, leading to the formation of secondary Fe precipitates. The Si ions co-dissolved from polysilicates may be embedded into secondary Fe precipitates, while these clustered Fe-Si precipitates displayed distinct morphology (e.g., "circular" shaped in the talc group, "fine-grained" shaped in the chlorite group, and "donut" shaped in the muscovite group). Moreover, the precipitates could join together and act as cementing agents aggregating mineral particles together, forming macroaggregates in talc and chlorite groups. The present findings revealed critical microbial functions on accelerating mineral dissolution, oxidation, and aggregation of pyrite and various silicates, which provided the eco-engineered feasibility of hardpan-based technology for mine site rehabilitation.

A rationally designed fluorescent probe for sulfur dioxide and its derivatives: applications in food analysis and bioimaging.

Exogenous sulfur dioxide (SO2) and its derivatives (SO32-/HSO3-) have been extensively utilized in food preservation and endogenous SO2 is recognized as a significant gaseous signaling molecule that can mediate various physiological processes. Overproduction and/or extensive intake of these species can trigger allergic reactions and even tissue damage. Therefore, it is highly desirable to monitor SO2 and its derivatives effectively and quantitatively both in vitro and in vivo. Herein, a new mitochondria-targeted fluorescent probe (PIB) had been constructed, which could ratiometrically recognize SO2 and its derivatives with excellent sensitivity (DL = 15.9 nM) and a fast response time (200 s). The obtained high selectivity and good adaptability of this SO2-specific probe in a wide pH range (6.5-10.0) allowed for quantitatively tracking of SO2 and its derivatives in real food samples (granulated sugar, crystal sugar, and white wine). In addition, PIB could locate at mitochondrion and was capable of imaging exogenous/endogenous SO2 in the cells and zebrafish. In particular, our findings represented one of the rare examples that have demonstrated endogenous SO2 is closely related with the apoptosis of cells. Importantly, probe PIB was successfully employed for in situ metabolic localization in mouse organs, implying the potential applications of our probe in further exploration on SO2-releated pathological and physiological processes.

Nanocarrier-Mediated Immunogenic Cell Death for Melanoma Treatment.

Melanoma, a highly aggressive skin tumor, exhibits notable features including heterogeneity, a high mutational load, and innate immune escape. Despite advancements in melanoma treatment, current immunotherapies fail to fully exploit the immune system's maximum potential. Activating immunogenic cell death (ICD) holds promise in enhancing tumor cell immunogenicity, stimulating immune amplification response, improving drug sensitivity, and eliminating tumors. Nanotechnology-enabled ICD has emerged as a compelling therapeutic strategy for augmenting cancer immunotherapy. Nanoparticles possess versatile attributes, such as prolonged blood circulation, stability, and tumor-targeting capabilities, rendering them ideal for drug delivery. In this review, we elucidate the mechanisms underlying ICD induction and associated therapeutic strategies. Additionally, we provide a concise overview of the immune stress response associated with ICD and explore the potential synergistic benefits of combining ICD induction methods with the utilization of nanocarriers.

Nanomedicine-induced programmed cell death enhances tumor immunotherapy.

BACKGROUND: There has been widespread concern about the high cancer mortality rate and the shortcomings of conventional cancer treatments. Immunotherapy is a novel oncology therapy with high efficiency and low side effects, which is a revolutionary direction for clinical oncology treatment. However, its clinical effectiveness is uneven. Based on the redefinition and reclassification of programmed cell death (PCD) (divided into necroptosis, ferroptosis, pyroptosis, and autophagy), the role of nanomedicine-induced PCD in cancer therapy has also received significant attention. Clinical and preclinical studies have begun to combine PCD with immunotherapy. AIM OF REVIEW: In this article, we present recent research in tumor immunotherapy, provide an overview of how nanomedicine-induced PCD is involved in tumor therapy, and review how nanomedicine-induced PCD can improve the limitations of immunotherapy to enhance tumor immunotherapy. The future development of nanomedicine-mediated PCD tumor therapy and tumor immunotherapy is also proposed Key scientific concepts of overview Nanomedicine-induced PCD is a prospective method of tumor immunotherapy. Nanomedicines increase tumor site penetration and targeting ability, and nanomedicine-mediated PCD activation can stimulate powerful anti-tumor immune effects, which has a good contribution to immunotherapy of tumors.

Effect of Corn Grinding Methods and Particle Size on the Nutrient Digestibility of Chahua Chickens.

This study investigates the effect of grinding methods, including roller mill, hammer mill, and two-stage grinding, on the particle size distribution of corn and the effect of corn particle size on the nutrient digestibility of native chickens in Southwest China. The roller mill, hammer mill, and a combination of the hammer mill and roller mill were used to obtain corn with various coarseness. Corn with different coarseness obtained using a combination of the hammer mill and roller mill was fed to Chahua chicken No. 2-type chickens (CHC2s). A total of 192 CHC2s in weeks 12 and 19 were randomly allocated to eight groups in triplicate. The results show that the geometric mean diameter (dgw) and the geometric standard deviation (Sgw) were significantly (p < 0.05) affected by the grinding methods. The Sgw obtained when using a sieve of 2.0 mm in a hammer mill was lower (p < 0.05) than that obtained using a 4.5 mm sieve. Combining the roller mill and hammer mill increased the uniformity of the particle size when grinding coarse particles. For fine particles, the dgw and Sgw obtained when using the hammer mill were significantly lower (p < 0.05) than those obtained when using the roller mill and two-stage grinding method. Reducing the particle size of the corn (<900 µm) significantly increased the dry matter, crude protein, amino acid digestibility, and apparent metabolizable energy in the chicken in weeks 12 and 19. Fine particles significantly increased the crude protein digestibility of the CHC2s at week 12, while there was no significant effect on the crude protein and amino acid digestibility in the CHC2s at week 19. In conclusion, different grinding methods can affect the particle size distribution. For a coarse particle size, combining the roller mill and hammer mill tends to produce a more uniform particle size. Finely ground corn (between 700 µm and 900 µm) improved the dry matter (DM), apparent metabolizable energy (AME), and crude protein (CP) digestibility of the CHC2s at week 12. An increased particle size did not impact the CP and amino acid (AA) digestibility of the CHC2s at week 19.

Neoprzewaquinone A Inhibits Breast Cancer Cell Migration and Promotes Smooth Muscle Relaxation by Targeting PIM1 to Block ROCK2/STAT3 Pathway.

Salvia miltiorrhiza Bunge (Danshen) has been widely used to treat cancer and cardiovascular diseases in Chinese traditional medicine. Here, we found that Neoprzewaquinone A (NEO), an active component of S. miltiorrhiza, selectively inhibits PIM1. We showed that NEO potently inhibits PIM1 kinase at nanomolar concentrations and significantly suppresses the growth, migration, and Epithelial-Mesenchymal Transition (EMT) in the triple-negative breast cancer cell line, MDA-MB-231 in vitro. Molecular docking simulations revealed that NEO enters the PIM1 pocket, thereby triggering multiple interaction effects. Western blot analysis revealed that both NEO and SGI-1776 (a specific PIM1 inhibitor), inhibited ROCK2/STAT3 signaling in MDA-MB-231 cells, indicating that PIM1 kinase modulates cell migration and EMT via ROCK2 signaling. Recent studies indicated that ROCK2 plays a key role in smooth muscle contraction, and that ROCK2 inhibitors effectively control the symptoms of high intraocular pressure (IOP) in glaucoma patients. Here, we showed that NEO and SGI-1776 significantly reduce IOP in normal rabbits and relax pre-restrained thoracic aortic rings in rats. Taken together, our findings indicated that NEO inhibits TNBC cell migration and relaxes smooth muscles mainly by targeting PIM1 and inhibiting ROCK2/STAT3 signaling, and that PIM1 may be an effective target for IOP and other circulatory diseases.

Cadmium-resistant phosphate-solubilizing bacteria immobilized on phosphoric acid-ball milling modified biochar enhances soil cadmium passivation and phosphorus bioavailability.

Cadmium (Cd) can accumulate in agriculture soil from the regular application of phosphorus (P) fertilizer. Microbiological method is considered as a potentially effective strategy that can not only remediate the Cd-contaminated soil but also provide the phosphorus needed for crop growth. However, the toxicity of Cd may affect the activity of microorganisms. To solve this problem, Klebsiella variicola with excellent phosphate solubilization ability (155.30 mg L-1 at 48 h) and Cd adsorption rate (90.84 % with 10 mg L-1 Cd initial concentration) was firstly isolated and identified in this study. Then, a phosphoric acid and ball milling co-modified biochar (PBC) was selected as the carrier to promote the activities of K. variicola under Cd pollution. Surface characterization revealed that the promotion of K. variicola by PBC was mainly attributed to the large specific surface area and diverse functional groups. Compared to contaminated soil, microbial PBC (MPBC) significantly increased the pakchoi biomass and phosphorus (P) content, while the Cd content in leave and root of pakchoi (Brassica chinensis L.) decreased by 25.90-43.46 % (P < 0.05). The combined application also favored the transformation of the resistant P fractions to bioavailable P, and facilitated the immobilization of 20.12 % exchangeable Cd to reducible, oxidizable, and residual Cd in the treated soil. High-throughput sequencing revealed that the response of the soil microbial community to the MPBC was more beneficial than K. variicola or PBC alone. Therefore, the application of MPBC has the potential to act as an efficient, stable, and environmentally friendly sustainable product for Cd remediation and enhanced P bioavailability in agricultural production.

A NIR fluorescent probe for dual imaging of mitochondrial viscosity and FA in living cells and zebrafish.

Formaldehyde (FA) and viscosity play multiple roles in human health and diseases, and viscosity has great regional differences due to the diversity of subcellular organelles. However, it is challenging to achieve dual detection of viscosity and FA in subcellular organelles. Herein, we developed a near infrared (NIR) fluorescent probe FA-Cy, which can simultaneously monitor the viscosity and FA concentration of mitochondria in living cells. The probe could detect mitochondrial viscosity and exogenous and endogenous FA in living cells and zebrafish.