A hypothalamic circuit that controls body temperature.

The homeostatic control of body temperature is essential for survival in mammals and is known to be regulated in part by temperature-sensitive neurons in the hypothalamus. However, the specific neural pathways and corresponding neural populations have not been fully elucidated. To identify these pathways, we used cFos staining to identify neurons that are activated by a thermal challenge and found induced expression in subsets of neurons within the ventral part of the lateral preoptic nucleus (vLPO) and the dorsal part of the dorsomedial hypothalamus (DMD). Activation of GABAergic neurons in the vLPO using optogenetics reduced body temperature, along with a decrease in physical activity. Optogenetic inhibition of these neurons resulted in fever-level hyperthermia. These GABAergic neurons project from the vLPO to the DMD and optogenetic stimulation of the nerve terminals in the DMD also reduced body temperature and activity. Electrophysiological recording revealed that the vLPO GABAergic neurons suppressed neural activity in DMD neurons, and fiber photometry of calcium transients revealed that DMD neurons were activated by cold. Accordingly, activation of DMD neurons using designer receptors exclusively activated by designer drugs (DREADDs) or optogenetics increased body temperature with a strong increase in energy expenditure and activity. Finally, optogenetic inhibition of DMD neurons triggered hypothermia, similar to stimulation of the GABAergic neurons in the vLPO. Thus, vLPO GABAergic neurons suppressed the thermogenic effect of DMD neurons. In aggregate, our data identify vLPO→DMD neural pathways that reduce core temperature in response to a thermal challenge, and we show that outputs from the DMD can induce activity-induced thermogenesis.

Removal of thallium by MnOx coated limestone sand filter through regeneration of KMnO4: Combination of physiochemical and biochemical actions.

Treatment of industrial thallium(Tl)-containing wastewater is crucial for mitigating environmental risks and health threats associated with this toxic metal. The incorporation of Mn oxides (MnOx) into the filtration system is a promising solution for efficient Tl(I) removal. However, further research is needed to elucidate the underlying mechanism behind MnOx-enhanced filtration and the rules of its stable operation. In this study, limestone, a cost-effective material, was selected as the filter media. Raw water with Mn(II), Tl(I), and other pollutants was prepared after a thorough investigation of actual industrial wastewater conditions. KMnO4 was added to induce the formation of MnO2 on limestone surfaces, while long-term operation led to enrichment of manganese oxidizing microorganisms (MnOM). Results revealed a dual mechanism. Firstly, most Mn(II) were oxidized by KMnO4 to form MnO2 attaching to limestone sands, and both Tl(I) and residual Mn(II) were adsorbed onto the newly formed MnO2. Subsequently, enzymes secreted by MnOM facilitated oxidation of remaining Mn(II), resulting in the generation of biogenic manganese oxides (BioMnOx) with numerous vacancies during long-term operation. The generated BioMnOx not only adsorbed Mn(II) and Tl(I) but also promoted their oxidation process. This approach offers an effective and sustainable method for removing both Mn(II) and Tl(I) from industrial wastewater, thereby addressing the challenges posed by thallium-contaminated effluents.

Dynamic retention of thallium(I) on humic acid: Novel insights into the heterogeneous complexation ability and responsiveness.

Widely distributed soil humic acid (HA) would significantly affect the environmental migration behavior of Tl(I), but a quantitative and mechanistic understanding of the dynamic Tl(I) retention process on HA is limited. A unified kinetic model was established by coupling the humic ion-binding model with a stirred-flow kinetic model, which quantified the complexation constants and responsiveness coefficients during dynamic Tl(I)-HA complexation. Furthermore, the heterogeneous complexation mechanism of HA and Tl(I) was revealed by batch adsorption experiments, stirred-flow migration experiments, and 2D-FTIR-COS analysis. An increase in pH significantly improved the responsiveness of HA organic binding sites, promoting Tl(I) dynamic retention. Monodentate carboxyl groups induced rapid Tl(I) complexation (kd = 1.9 min-1) in strongly acidic environments. Under weakly acidic conditions, Tl(I) retention on HA was mainly attributed to the synergistic complexation effect of carboxyl and amide groups. Among the groups, multidentate carboxyl-phenolic hydroxyl sites could achieve sustained Tl(I) retention due to their stable complexing properties (logK = 4.48∼7.46) and slow response (kd = 1.1 × 10-3 min-1). These findings are crucial for a comprehensive understanding of the environmental interactions of Tl(I) with humic substances in swamp environments.

Impact of biochar colloids on thallium(I) transport in water-saturated porous media: Effects of pH and ionic strength.

Understanding the migration behavior of thallium (TI) in subsurface environments is essential for Tl pollution prevention. With the wide production and utilization of biochar, the notable ability of biochar colloids to carry environmental contaminants may make these colloids important for Tl(I) mobility. This study systematically investigated the impact of wood-derived biochar (WB) and corn straw-derived biochar (CB) colloids on Tl(I) transport in water-saturated porous media under different pH (5, 7 and 10) and ionic strengths (ISs) (1, 5 and 50 mM NaNO3). WB colloids improved Tl(I) transport under all IS conditions at pH 7 due to the adsorption capacity of biochar and competition for adsorption sites on the sand surface. However, at IS 50 mM, CB colloids slightly impeded Tl(I) mobility due to the straining. In addition, both WB and CB colloids accelerated Tl(I) mobility under all pH conditions at IS 5 mM. At pH 10, the promotion effect was more obvious due to the deprotonation of O-containing functional groups and higher fluidity of biochar colloids. Furthermore, the two-site nonequilibrium model and two-site kinetic attachment/detachment model suitably described the breakthrough curves (BTCs) of Tl(I) and biochar colloids, respectively. The colloid-facilitated solute transport model could also describe Tl(I) transport influenced by biochar colloids reasonably well. This study provides insight into the migration and fate of Tl(I) in the presence of biochar colloids.

Thermodynamic and kinetic coupling modeling for thallium(I) sorption at a heterogeneous titanium dioxide interface.

The transformations of monovalent thallium (Tl) in an aqueous environment may be affected significantly by Tl(I) partitioning at the solid-water interface during sorption. Models used to quantify the kinetics of Tl(I) adsorption on heterogeneous adsorbents and formation of multiple complexes under a wide range of water chemistry conditions can accurately predict the environmental fate of thallium. In this study, Tl(I) sorption on representative titanium dioxide at different solution pH values and loading concentrations was investigated with two unified adsorption models, diffuse layer modeling and kinetics modeling. Three Tl(I) surface complexes, TiOTl, TiOHTl+, and TiOTlOH-, were used in the diffuse layer model and successfully described batch adsorption and the results of spectroscopic analyses. The contribution of TiOHTl+ to the adsorption capacity was much higher than those of TiOTl and TiOTlOH- under neutral and weakly alkaline conditions, while the species TiOTlOH- predominated among Tl(I) complexes in strongly alkaline environments. The adsorption and desorption rate coefficients derived from thermodynamics and kinetics coupling modeling suggested the influence of different complex characteristics on adsorption and desorption of Tl(I). Our results provide a comprehensive model for predicting the dynamic binding behavior of Tl at heterogeneous solid-water interfaces.

Retention of thallium(I) on goethite, hematite, and manganite: Quantitative insights and mechanistic study.

The reversibility of monovalent thallium (Tl) absorption on widely distributed iron/manganese secondary minerals may affect environmental Tl migration and global cycling. Nevertheless, quantitative and mechanistic studies on the interfacial retention and release reactions involving Tl(I) are limited. In this study, batch and stirred-flow experiments, unified kinetics modeling, spectral detection, and theoretical calculations were used to elucidate the retention behaviors of Tl(I) on goethite, hematite, and manganite with different solution pH values and Tl loading concentrations. Sustained Tl(I) retention (kd, MeOHTl=0.005∼0.018 min-1) was induced by hydration of the surface hydroxyl groups. Rapid Tl(I) retention (kd,MeOTlOH=1.232∼2.917 min-1) was enhanced by the abundant hydroxide ions and deprotonated hydroxyl groups, which increased the Tl(I) binding ability. Compared to the ambient Tl concentration, pH had a more substantial effect on the formation and distribution of surface Tl(I) binding species. In alkaline environments, the large adsorption energy for Tl(I) binding to surface species (Eads=-6.14 eV) induced fast Tl(I) binding response on the surfaces of iron/manganese secondary minerals. This study provides new insights into the heterogeneous surface complexation and retention behaviors of Tl(I) and contributes to an in-depth understanding of the environmental fate of Tl and the remediation of Tl contamination.

Cotransport of thallium(I) with polystyrene plastic particles in water-saturated porous media.

Exploring the transport behaviors of thallium (Tl) in porous media is crucial for predicting Tl pollution in natural soils and groundwater. In recent years, the misuse of plastics has led to plastic becoming an emerging pollutant in soil. In this work, the effects of plastic particles on Tl(I) transport in water-saturated sand columns were investigated under different ionic strengths (ISs), pH values, and plastic particle sizes. The two-site nonequilibrium model was selected to fit the breakthrough curves (BTCs) of Tl(I). The results demonstrated that nanoplastics (NPs) accelerated Tl(I) transport at pH 7, which might be attributed to the competitive adsorption of NPs and Tl(I) on sand surfaces. However, at pH 5, the deposited NPs might provide more adsorption sites for Tl(I), and thus enhance its retention in the columns. In addition, the "straining" process could intercept microplastics (MPs) with Tl(I) that was attached under unfavorable attachment conditions, which would result in the inhibited mobility of Tl(I). On the other hand, the migration of plastics was restrained to some extent when Tl(I) was present. Overall, the findings from this work provided a new perspective for understanding the transport of Tl(I) and plastics in subsurface environments.

A systematic in silico mining of the mechanistic implications and therapeutic potentials of estrogen receptor (ER)-α in breast cancer.

Estrogen receptor (ER)-α has long been a potential target in ER-α-positive breast cancer therapeutics. In this study, we integrated ER-α-related bioinformatic data at different levels to systematically explore the mechanistic and therapeutic implications of ER-α. Firstly, we identified ER-α-interacting proteins and target genes of ER-α-regulating microRNAs (miRNAs), and analyzed their functional gene ontology (GO) annotations of those ER-α-associated proteins. In addition, we predicted ten consensus miRNAs that could target ER-α, and screened candidate traditional Chinese medicine (TCM) compounds that might hit diverse conformations of ER-α ligand binding domain (LBD). These findings may help to uncover the mechanistic implications of ER-α in breast cancer at a systematic level, and provide clues of miRNAs- and small molecule modulators- based strategies for future ER-α-positive breast cancer therapeutics.