Unveiling the heavy-metal ion critical role in γ-dicalcium silicate: from solidification to early hydration.

The heavy-metal ion critical role in γ-dicalcium silicate (γ-C2S) both in terms of solidification mechanism and hydration is still unclear. In this work, the solidification mechanism and the effect on initiating hydration of these three heavy-metal ions (Ba, Cd, and Cr) in γ-C2S is systemically studied by well-defined ab initio calculations. The calculated results show that the solid solution tendency of ions originates from the charge contribution, and the charge localization caused by the doping of Cr ions weakens the surface water adsorption. These insights will provide theoretical guidance for the low-carbon cement development by γ-C2S.

Clinical application of nanopore-targeted sequencing technology in bronchoalveolar lavage fluid from patients with pulmonary infections.

The rapid and effective identification of pathogens in patients with pulmonary infections has posed a persistent challenge in medicine, with conventional microbiological tests (CMTs) proving time-consuming and less sensitive, hindering early diagnosis of respiratory infections. While there has been some research on the clinical performance of targeted sequencing technologies, limited focus has been directed toward bronchoalveolar lavage fluid (BALF). This study primarily evaluates the pathogen detection capabilities of nanopore-targeted sequencing (NTS) in BALF, providing a comprehensive analysis. The retrospective study, spanning from January 2022 to November 2023, includes 223 patients exclusively sourced from a single center. We conducted a detailed comparative analysis among NTS, targeted next-generation sequencing (tNGS), and CMTs. Initially, we compared the detection capabilities of NTS and tNGS and found no significant differences in their sensitivity and specificity. Specifically, we observed that the sensitivity of NTS was significantly higher than that of CMTs (74.83% vs 33.11%, P < 0.001). Furthermore, NTS exhibited a higher positivity rate in common pulmonary infections (62.88% vs. 23.48%) and in clinically suspected tuberculosis patients compared to CMTs (87.18% vs. 48.72%). Additionally, NTS showed less susceptibility to antibiotic interference, indicating a more sensitive detection capability, especially in detecting fastidious organisms. It complements GeneXpert in tuberculosis diagnosis and offers excellent advantages in identifying pathogens challenging for CMTs, such as non-tuberculous mycobacteria and viruses. Moreover, NTS significantly shortens the reporting time and is only a quarter of the cost of metagenomic next-generation sequencing. Clearly, NTS can facilitate faster and more cost-effective early diagnosis of respiratory infections.IMPORTANCEThis study holds paramount significance in advancing the field of respiratory infection diagnostics. By assessing the pathogen detection capabilities in bronchoalveolar lavage fluid (BALF) of patients with pulmonary infections, we illuminate the promising potential of nanopore-targeted sequencing (NTS). The findings underscore NTS as a comparable yet distinct alternative to traditional methods like comprehensive conventional microbiological tests (CMTs). Notably, NTS demonstrates a pivotal edge, expanding the spectrum of identified pathogens, particularly excelling in the detection of challenging entities like non-tuberculous mycobacteria and viruses. The study also highlights the complementary role of NTS alongside GeneXpert in the identification of tuberculosis, providing a comprehensive overview of the diagnostic landscape for respiratory infections. This insight carries significant implications for clinicians seeking rapid, cost-effective, and accurate diagnostic tools in the realm of pulmonary infections.

Case report: Oxaliplatin-induced idiopathic non-cirrhotic portal hypertension: a case report and literature review.

Oxaliplatin has become a widely used agent in neoadjuvant chemotherapy for gastrointestinal tract tumors and is an integral part of the therapeutic approach for managing colorectal cancer recurrences and metastases, resulting in a more favorable prognosis for patients. Nevertheless, oxaliplatin can give rise to idiopathic non-cirrhotic portal hypertension (INCPH). The emergence of INCPH can disrupt tumor chemotherapy and incite persistent adverse reactions in later stages, significantly complicating clinical management. Consequently, we have presented a case report of INCPH induced by oxaliplatin chemotherapy with the aim of advancing the diagnosis and treatment of this condition, with a particular focus on the clinical manifestations. This study has ascertained that the condition is primarily attributed to complications related to portal hypertension, such as gastrointestinal bleeding, splenomegaly, and hypersplenism. The pathological features primarily involve hepatic sinus dilation and congestion, portal obstruction, absence, stenosis, shunting, localized venous and perisinusoidal fibrosis, as well as hepatocellular atrophy. Treatment primarily concentrates on strategies typically employed for cirrhosis. Endoscopic ligation, sclerotherapy, and non-selective beta-blockers (NSBBs) can be selected to prevent and treat variceal hemorrhage. Transjugular intrahepatic portosystemic shunt (TIPS) and liver transplantation can also be chosen for severe cases. Notably, despite the timely discontinuation of oxaliplatin, most patients continue to experience disease progression, ultimately resulting in a poor prognosis due to either tumor advancement or the ongoing progression of portal hypertension. This emphasizes the importance for physicians to be aware of and consider the risk of INCPH when prescribing oxaliplatin.

The ferroxidases are critical for Fe(II) oxidation in xylem to ensure a healthy Fe allocation in Arabidopsis thaliana.

The long-distance transport of iron (Fe) in the xylem is critical for maintaining systemic Fe homeostasis in plants. The loading form of Fe(II) into the xylem and the long-distance translocation form of Fe(III)-citrate have been identified, but how Fe(II) is oxidized to Fe(III) in the xylem remains unknown. Here, we showed that the cell wall-resided ferroxidases LPR1 and LPR2 (LPRs) were both specifically expressed in the vascular tissues of Arabidopsis thaliana, while disruption of both of them increased Fe(II) in the xylem sap and caused excessive Fe deposition in the xylem vessel wall under Fe-sufficient conditions. As a result, a large amount of Fe accumulated in both roots and shoots, hindering plant growth. Moreover, under low-Fe conditions, LPRs were preferentially induced in old leaves, but the loss of LPRs increased Fe deposition in the vasculature of older leaves and impeded Fe allocation to younger leaves. Therefore, disruption of both LPRs resulted in severer chlorosis in young leaves under Fe-deficient conditions. Taken together, the oxidation of Fe(II) to Fe(III) by LPRs in the cell wall of vasculature plays an important role in xylem Fe allocation, ensuring healthy Fe homeostasis for normal plant growth.

Promotion of the root development and Zn uptake of Sedum alfredii was achieved by an endophytic bacterium Sasm05.

Endophyte-assisted phytoremediation has gained increasing attention. However, the interacting mechanisms of endophytes and metal hyperaccumulators are still not clear. An endophytic bacterium Pseudomonas fluorescens Sasm05 inoculation promoted Sedum alfredii Hance rooting and root development, in which the specific root length (SRL) and average number of root tips (ART) increased to 2.09- and 3.35-fold, respectively. Sasm05 inoculation promoted plant growth, increased the chlorophyll content, and elevated Zn uptake of plant at excess Zn supply. At 200 µM Zn treatment level, Sasm05 inoculation increased plant biomass and the chlorophyll content by more than 40%, and root Zn content by 40%. Furthermore, Sasm05 inoculation upregulated the expression of the Zn transporter SaIRT1 to 3.43-fold in the roots, while another transporter SaNramp1 expression was increased to 38.66-fold in the roots and 7.53-fold in the shoots. Time course study showed the best effects of Sasm05 on plant biomass and the chlorophyll content were detected at 30 d, while for Zn content at 3 d. These results firstly provided molecular evidences of endophytic bacteria in facilitating host plant Zn uptake, which will absolutely benefit the understanding of interacting mechanisms between hyperaccumulators and their endophytes.

The effects of endophytic bacterium SaMR12 on Sedum alfredii Hance metal ion uptake and the expression of three transporter family genes after cadmium exposure.

A hydroponic experiment was conducted to investigate the effects of an endophytic bacterium SaMR12 on Sedum alfredii Hance metal ion accumulation, chlorophyll concentration, and the expression of three metal transporter families, zinc-regulated transporters, iron-regulated transporter-like protein (ZIP); natural resistance-associated macrophage protein; and heavy metal ATPase (HMA) at different Cd treatment levels. The results showed that at relatively low Cd conditions (≤25 µM), SaMR12 demonstrated a 19.5-27.5% increase in Fe, a 46.7-90.7% increase in Zn, and a 7.9-43.7% increase in Cu content in the shoot and elevated expression of SaIRT1, SaZIP3, SaHMA2, and SaNramp3 in the shoot and SaZIP1, SaHMA2, SaNramp1, and SaNramp3 in the root. At high Cd conditions (100 and 400 µM), SaMR12 demonstrated a 16.4-18.5% increase in leaf chlorophyll concentration, a 18.9-23.2% increase in Fe, and a 15.4-17.5% increase in Mg content in the shoot and elevated expression of SaZIP3, SaNramp6, SaHMA2, and SaHMA3 in the shoot and SaZIP3, SaNarmp1, SaNarmp3, and SaNarmp6 in the root. These results indicated that SaMR12 can elevate essential metal ion uptake and regulate the expression of transport genes to promote plant growth and enhance Cd tolerance and uptake to improve Cd accumulation up to 118-130%.

The Effects of the Endophytic Bacterium Pseudomonas fluorescens Sasm05 and IAA on the Plant Growth and Cadmium Uptake of Sedum alfredii Hance.

Endophytic bacteria have received attention for their ability to promote plant growth and enhance phytoremediation, which may be attributed to their ability to produce indole-3-acetic acid (IAA). As a signal molecular, IAA plays a key role on the interaction of plant and its endomicrobes. However, the different effects that endophytic bacteria and IAA may have on plant growth and heavy metal uptake is not clear. In this study, the endophytic bacterium Pseudomonas fluorescens Sasm05 was isolated from the stem of the zinc (Zn)/cadmium (Cd) hyperaccumulator Sedum alfredii Hance. The effects of Sasm05 and exogenous IAA on plant growth, leaf chlorophyll concentration, leaf Mg2+-ATPase and Ca2+-ATPase activity, cadmium (Cd) uptake and accumulation as well as the expression of metal transporter genes were compared in a hydroponic experiment with 10 µM Cd. The results showed that after treatment with 1 µM IAA, the shoot biomass and chlorophyll concentration increased significantly, but the Cd uptake and accumulation by the plant was not obviously affected. Sasm05 inoculation dramatically increased plant biomass, Cd concentration, shoot chlorophyll concentration and enzyme activities, largely improved the relative expression of the three metal transporter families ZRT/IRT-like protein (ZIP), natural resistance associated macrophage protein (NRAMP) and heavy metal ATPase (HMA). Sasm05 stimulated the expression of the SaHMAs (SaHMA2, SaHMA3, and SaHMA4), which enhanced Cd root to shoot translocation, and upregulated SaZIP, especially SaIRT1, expression to increase Cd uptake. These results showed that although both exogenous IAA and Sasm05 inoculation can improve plant growth and photosynthesis, Sasm05 inoculation has a greater effect on Cd uptake and translocation, indicating that this endophytic bacterium might not only produce IAA to promote plant growth under Cd stress but also directly regulate the expression of putative key Cd uptake and transport genes to enhance Cd accumulation of plant.