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Stomatal conductance (SC) and chlorophyll concentration (CC) are sensitive to soil matric suction (ψ). The relationship between these two plant parameters and ψ in the root zone can help understand the water uptake efficiency and photosynthetic capacity of a plant. This paper aims to quantify the relationships between SC and CC with ψ, for Schefflera arboricola grown in compacted bare silty sand and biochar amended soil (BAS). Plant parameters (SC, CC, leaf area (LA), root length (RL)) and ψ were regularly monitored in an atmospheric controlled room. The maximum recorded SC was greater in BAS than that in bare soil due to the higher water demand of LA. Based on measured data upon evapotranspiration, two equations are proposed to interpret the effects of ψ on plant water uptake and photosynthesis. A fitting equation is established to relate normalized SC with ψ to identify a threshold suction ([Formula: see text]; indicator of drought stress resistance). The magnitude of [Formula: see text] is found to be mainly dependent on LA/RL ratio and root ends. Furthermore, a new relationship between CC and ψ is observed and developed. A decrease in CC at higher ψ is attributed to leaf senescence and stomatal closure, restricting plant to produce more chlorophyll.

Comparison of the nanostructured Si photocathodes fabricated by chemical etching (c-Si), electrochemical etching (ec-Si) and photoelectrochemical etching (pec-Si) and their dramatically enhanced PEC water splitting.

Since the water oxidation half-reaction requires the transfer of multi-electrons and the formation of O-O bond, it's crucial to investigate the catalytic behaviours of semiconductor photoanodes. In this work, a bio-inspired copper-bipyridine catalyst of Cu(dcbpy) is decorated on the nanoporous Si photoanode (black Si, b-Si). Under AM1.5G illumination, the b-Si/Cu(dcbpy) photoanode exhibits a high photocurrent density of 6.31 mA cm

The growing evidence over the past few decades has indicated that the photodynamic antitumor activity of transition metal complexes, and Re(I) compounds are potential candidates for photodynamic therapy. This study reports the synthesis, characterization, and anti-tumor activity of three new Re(I)–guadinium complexes. Cytotoxicity tests reveal that complex Re1 increased cytotoxicity by 145-fold from IC50 > 180 μM in the dark to 1.3 ± 0.7 μM following 10 min of light irradiation (425 nm) in HeLa cells. Further, the mechanism by which Re1 induces apoptosis in the presence or absence of light irradiation was investigated, and results indicate that cell death was caused through different pathways. Upon irradiation, Re1 first accumulates on the cell membrane and interacts with death receptors to activate the extrinsic death receptor-mediated signaling pathway, and then is transported into the cell cytoplasm. Most of the intracellular Re1 locates within mitochondria, improving the reactive oxygen species level, and decreasing mitochondrial membrane potential and ATP levels, and inducing the activation of caspase-9 and, thus, apoptosis. Subsequently, the residual Re1 can translocate into the cell nucleus, and activates the p53 pathway, causing cell cycle arrest and eventually cell death.

Efficient delivery of chemotherapeutic agents into tumor cells and reversal of chemoresistance are crucially important to enhance cancer therapy. We fabricated pH/redox dual responsive nanocarriers based on cell penetrating peptides (TAT) functionalized TPGS (cTAT-TPGS) and polypeptide (PEG-b-poly(aspartic-lipoic acid), PPAL) to reduce the permanent drug release and overcome multidrug resistance. TAT was used to functionalize TPGS and shielded by pH-responsive fatty acids, and polypeptides with lipoic acid side chains (PPAL) were synthesized. Reversibly crosslinked hybrid micelles (RCMs) were fabricated based on cTAT-TPGS and PPAL. RCMs nanocarriers exhibited acid-responsive charge reversal and redox-responsive drug release. The in vitro results showed that the RCMs could be efficiently internalized by the MCF-7/ADR cells in an acidic microenvironment and inhibited the DOX efflux, causing a higher cytotoxicity than non-crosslinked nanocarriers. Furthermore, the dual-responsive structure effectively prolonged the circulation time of RCM nanocarriers and achieved a high level of accumulation in cancer cells in vivo, leading to much more effective inhibition of tumor growth. The DOX-loaded RCMs also showed excellent biosafety, especially for the myocardium tissue. This novel strategy provided an effective platform for drug target delivery and reversal of MDR.

The efficient triggering of prodrug release has become a challengeable task for stimuli-responsive nanomedicine utilized in cancer therapy due to the subtle differences between normal and tumor tissues and heterogeneity. In this work, a dual ROS-responsive nanocarriers with the ability to self-regulate the ROS level was constructed, which could gradually respond to the endogenous ROS to achieve effective, hierarchical and specific drug release in cancer cells. In brief, DOX was conjugated with MSNs via thioketal bonds and loaded with β-Lapachone. TPP modified chitosan was then coated to fabricate nanocarriers for mitochondria-specific delivery. The resultant nanocarriers respond to the endogenous ROS and release Lap specifically in cancer cells. Subsequently, the released Lap self-regulated the ROS level, resulting in the specific DOX release and mitochondrial damage in situ, enhancing synergistic oxidation-chemotherapy. The tumor inhibition Ratio was achieved to 78.49%. The multi-functional platform provides a novel remote drug delivery system in vivo.

PDT is a well-established therapeutic modality for many types of cancer. Photoluminescent cyclometalated iridium(III) complexes are one of the most commonly used classes of organometallic compounds with potential beneficial applications in bioimaging and as promising anticancer agents. In the present study, three new cyclometalated iridium(III) complexes (Ir1–Ir3) containing guanidinium ligands were found to exert excellent cytotoxic effects on different types of cancer cells upon light irradiation at 425 nm. Notably, Ir1 conferred almost no dark toxicity (IC50 > 100 μM) to HepG2 cells, but the value decreased by 387-fold to 0.36 μM following 10 min of light irradiation (425 nm). Further mechanistic investigation revealed that complex Ir1 could induce apoptosis via the activation of reactive oxygen species (ROS)-mediated mitochondrial signaling pathways in the presence or absence of light irradiation. In vivo studies demonstrated that Ir1 significantly inhibited tumor growth in HepG2 xenograft-bearing mice under light irradiation at 425 nm. Taken together, these findings indicate that designing PDT-based Ir(III) complexes may hold a great deal of promise for anticancer drug development.

A methionine methyl ester-modified coumarin derivative was designed and synthesized, which could discriminate Cu2+ from other metal ions in HEPES buffer (10 mM, pH 7.4)/CH3CN (40:60, V/V). The detection limit of WM toward Cu2+ was 1.84 × 10−7 M, which was lower than the concentration of Cu2+ in drinking water suggested by WHO and EPA. And the proposed coordination mode exhibiting the interaction between WM and Cu2+ was studied by UV–Vis, fluorescence spectrum, ESI-MS and FT-IR. Based on the fluorescent reversibility of WM, WM was considered as a molecular logic gate and molecular keypad lock. In addition, the test strips and the silica gel plates prepared from the solution of WM also demonstrate the favorable selectivity toward Cu2+.

Bauxite residue is a highly alkaline waste product from refining bauxite ore. Bioremediation driven by microbial activities has been evidently effective in lowering the alkalinity of bauxite residues, which is critical to the initiation of pedogenesis under engineered conditions. The present study investigated the changes of alkalinity and aggregation of bauxite residue at different depth in response to the colonization of Penicillium oxalicum in columns. The results demonstrated that the inoculation of P. oxalicum decreased the residue’s pH to about 7 after 30 d only at the surface layer, which was exposed to aerobic conditions. The formation of aggregates was improved overall in the organic matter treated bauxite residue. However, the EC of bauxite residue increased with time under the incubation condition, probably due to accelerated hydrolysis of sodium-rich minerals. The inoculation of P. oxalicum had no effects on urease activity, but increased cellulose enzyme activity at surface layer only.

Bauxite residue deposit area (BRDA) is a typical abandoned mining wasteland representing extreme hostile environment with increased alkalinity. Microbially-driven neutralization of bauxite residue, based on the microbial acid producing metabolisms, is a novel strategy for achieving rapid pH neutralization and thus improving its environmental outcomes. The hypothesis was that these extreme conditions promote microbial communities which are capable of novel ecologically relevant functions. Several alkaliphilic acid producing bacteria were isolated in this study. One strain was selected for its superior growth pattern and acid metabolism (termed EEEL02). Based on the phylogenetic analysis, this strain was identified as Bacillus thuringiensis. The optimized fermentation conditions were as follows: pH 10; NaCl concentration 5%; temperature 25 °C; EEEL02 preferred glucose and peptone as carbon and nitrogen sources, respectively. Based on optimal fermentation conditions, EEEL02 induced a significant pH reduction from 10.26 to 5.62 in 5-day incubation test. Acetic acid, propionic acid and CO2 (g) were the major acid metabolites of fermentation, suggesting that the pH reduction in bauxite residue may be caused by acid neutralization derived from microbial metabolism. This finding provided the basis of a novel strategy for achieving rapid pH neutralization of bauxite residue.

Ruthenium complexes with good biological properties have attracted increasing attention in recent decades. In this work, three ruthenium polypyridine complexes containing 5-fluorouracil derivatives as ligands, [Ru(bpy)

As the "powerhouse" of a cell, mitochondria maintain energy homeostasis, synthesize ATP via oxidative phosphorylation, generate ROS signaling molecules, and modulate cell apoptosis. Herein, three Re(I) complexes bearing guanidinium derivatives have been synthesized and characterized. All of these complexes exhibit moderate anticancer activity in HepG2, HeLa, MCF-7, and A549 cancer cells. Mechanism studies indicate that complex 3, [Re(CO)3(L)(Im)](PF6)2, can selectively localize in the mitochondria and induce cancer cell death through mitochondria-associated pathways. In addition, complex 3 can effectively depress the ability of cell migration, cell invasion, and colony formation.

Globally, bauxite residue is creating extensive environmental problems. Nevertheless, there are numerous functional microorganisms that exist in this extreme environment, and fungus has an essential role in the pedogenesis of bauxite residue. This study describes a microbial method to reduce the alkalinity of bauxite residue through the actions of a functional fungus to produce acidic substances. Bauxite residue samples were screened for fungal activity, and fungal tolerance was assessed using saline and alkaline media of varying concentrations, using aniline blue-PDA medium to evaluate acid production. A tolerant fungus with the ability to produce acidic substances was selected and named EEEL01 (Environmental Ecological Engineering Laboratory No. 01). Further morphological and molecular characterization identified this fungus as Penicillium oxalicum. Factors including pH, NaCl concentration, carbon and nitrogen sources were used to test the efficiency of acid production by the fungus. Based on optimal growth conditions, bauxite residue inoculated with EEEL01 reduced pH from 10.26 to 6.48 over 11 days. These results suggest that EEEL01 could effectively grow and release organic acids under extreme alkaline and saline conditions, which provide the potential for remediation.

A new rhodamine-6G-based chemosensor X was designed and synthesized for the colorimetric and fluorometric detection of Hg2+. The chemosensor X responsed to Hg2+ had good sensitivity, high selectivity and excellent reversibility in HEPES buffer (10 mM, pH 7.4)/CH3CN (40:60, V/V). The recognition mechanism of X toward Hg2+ was evaluated by Job's plot, IR and MS. Meanwhile, X-Hg2+ fluorescence lifetime was also measured. It was interesting that X displayed favorable reversibility to form an “off-on-off” type signaling behavior with the Hg2+-induced emission spectra being quenched by I−. Furthermore, it could be applied as a molecular logic gate and test strips based on X exhibited a good reversibility selectivity to Hg2+.

Bauxite residue, a byproduct of alumina manufacture, is a serious environmental pollutant due to its high leaching contents of metals and caustic compounds. Four typical anions of CO32-, HCO3-, Al(OH)4- and OH- (represented caustic compounds) and metal ions (As, B, Mo and V) were selected to assess their leaching behavior under dealkalization process with different conditions including liquid/solid ratio (L/S ratio), temperature and leaching time. The results revealed that washing process could remove the soluble composition in bauxite residue effectively. The leaching concentrations of typical anions in bauxite residue decreased as follows: c(CO32-) > c(HCO3-) > c[Al(OH)4-] > c(OH-). L/S ratio had a more significant effect on leaching behavior of OH-, whilst the leaching concentration of Al(OH)4- varied larger underleaching temperature and time treatment. Under the optimal leaching, the total alkaline, soluble Na concentrations, exchangeable Ca concentrations were 79.52, 68.93, and 136.0 mmol/L, respectively, whilst the soluble and exchangeable content of As, B, Mo and V in bauxite residue changed slightly. However, it should be noted that water leaching has released metal ions such as As, B, Mo and V in bauxite residue to the surrounding environment. The semiquantitative analysis of XRD revealed that water leaching increased the content of gismondine from 2.4% to 6.4%. The SEM images demonstrated the dissolution of caustic compounds on bauxite residue surface. The correlation analysis indicated that CO32- and HCO3- could effectively reflect the alkalinity of bauxite residue, and may be regarded as critical dealkalization indicators to evaluate alkalinity removal in bauxite residue.

A new fluorescent probe L based on the rhodamine 6G platforms for Fe3+ has been designed and synthesised. L showed excellent selectivity and high sensitivity for Fe3+ against other metal ions such ...

A great deal of manganese and associated heavy metals (such as Ni, Cu, Zn, Cd, Pb, etc.) was produced in manganese mining, smelting, and other processes and weathering and leaching of waste slag, which entered rainwater runoff by different means under the action of rainfall runoff. It caused heavy metal pollution in water environment to surrounding areas, and then environmental and human health risks were becoming increasingly serious. In the Xiangtan manganese mine, we studied the characteristics of nutritional pollutants and heavy metals by using the method of bounded runoff plots on the manganese tailing wasteland after carrying out some site treatments using three different approaches, such as (1) exposed tailings, the control treatment (ET), (2) external-soil amelioration and colonization of Cynodon dactylon (Linn.) Pers. turf (EC), and (3) external-soil amelioration and seedling seeding propagation of Cynodon dactylon (Linn.) Pers. (ES). The research showed that the maximum runoff occurred in 20,140,712 rainfall events, and the basic law of runoff was EC area > ET area > ES area in the same rainfall event. The concentration of total suspended solids (TSS) and chemical oxygen demand (COD) of three ecological restoration areas adopted the following rule: ET area > EC area > ES area. Nitrogen (N) existed mainly in the form of water soluble while phosphorus (P) was particulate. The highest concentrations of total nitrogen (TN) and total phosphorus (TP) were 11.57 ± 2.99 mg/L in the EC area and 1.42 ± 0.56 mg/L in the ET area, respectively. Cr, Ni, Pb, Zn, Mn, and Cu in surface runoff from three restoration types all exceeded the class V level of the environmental quality standard for surface water except Cu in EC and ES areas. Pollution levels of heavy metals in surface runoff from three restoration areas are shown as follows: ET area > EC area > ES area. There was a significant positive correlation between TSS and runoff, COD, and TP. And this correlation was significant between total dissolved nitrogen (TDN), TN, total dissolved phosphorus (TDP), and TP. The six heavy metals (Cu, Ni, Pb, Zn, Mn, and Cr) in surface runoff of different ecological restoration areas were strongly related to each other, and were significantly related to the TSS.

Mitochondrial damage will hinder the energy production of cells and produce excessive ROS (reactive oxygen species), resulting in cell death through autophagy or apoptosis. In this paper, four cyclometalated iridium(III) complexes (Ir1: [Ir(piq)2L]PF6; Ir2: [Ir(bzq)2L]PF6; Ir3: [Ir(dfppy)2L]PF6; Ir4: [Ir(thpy)2L]PF6; piq = 1-phenylisoquinoline; bzq = benzo[h]quinoline; dfppy = 2-(2,4-difluorophenyl)pyridine;thpy = 2-(2-thienyl)pyridine; L = 1,10-phenanthroline-5-amine) were synthesized and characterized. Cytotoxicity tests show that these complexes have excellent cytotoxicity to cancer cells, and mechanism studies indicatethat these complexes can specifically target mitochondria. Complexes Ir1 and Ir2 can damage the function of mitochondria, subsequently increasing intracellular levels of ROS, decreasing MMP (mitochondrial membrane potential), and interfering with ATP energy production, which leads to autophagy and apoptosis. Furthermore, autophagy induced by Ir1 and Ir2 can promote cell death in coordination with apoptosis. Surprisingly, these four complexes also showed moderate antibacterial activity to S. aureusand P. aeruginosa.

Bauxite residue often has poor physical conditions which impede plant growth. Native plant encroachment on a bauxite residue disposal area in Central China reveals that natural regeneration may improve its physicochemical properties. Residue samples collected from three different disposal ages were assessed to evaluate residue micromorphology and three-dimensional (3D) aggregate microstructure under natural regeneration. The residue aggregates in different disposal ages were divided in two sections: macro-aggregate (2–1 mm) and micro-aggregate (0.25–0.05 mm). Residue aggregate micromorphology was determined by scanning electron microscope and energy dispersive X-ray spectroscopy, and the residue aggregate microstructure was determined by synchrotron-based X-ray micro-computed tomography (SR-μCT) and image analysis techniques. Natural regeneration may improve residue aggregate stability and form a stable aggregate structure. Calcium content increased whilst sodium content decreased significantly on the surface of residue aggregates. Under natural soil-forming processes bauxite residue porosity, specific surface area, average length of paths, and average tortuosity of paths all significantly increased. This demonstrated that natural regeneration may stimulate the formation of stable aggregate structure in residues. Further understanding should focus on particle interaction forces and agglomeration mechanisms with the addition of external ameliorations.

A methionine methyl ester-modified coumarin derivative was designed and synthesized, which could discriminate Cu

Bauxite residue disposal areas (BRDA) appear to result in the heavy metal pollution of the farm fields surrounding them. In total, 194 topsoil samples were collected from the fields surrounding a BRDA in Guangxi in order to comprehensively understand the pollutant characteristics. These characteristics and their ecological risks were assessed by the Nemerow and Harkanson indices, whilst the sources and correlations of eight heavy metals (V, Cr, Ni, Cu, Zn, As, Pb, and Co) were analyzed by means of the spatial interpolation method, correlation analysis, and principal component analysis (PCA). The results demonstrated that the surrounding fields were seriously polluted by heavy metals. Ninety-two percent of samples were polluted, including 36% that showed serious pollution, and As was the dominant contaminant. The ecological risk results showed that the risks of the surrounding fields were medium, and As was responsible for 68% of this. Spatial interpolation suggested that concentrations of heavy metals in the northeastward and southwestward areas were higher, however the southeastward areas were lower. Multivariate statistics indicated that the possible source of As contaminant was different to those of V, Ni, Zn, Pb, and Co; As was primarily influenced by anthropogenic contamination, including atmospheric sedimentation, and agricultural fertilization. Cr was affected by both soil parent material and atmospheric sedimentation, whereas V, Ni, Zn, Pb, And Co levels were mainly affected by soil parent material.

A new rhodamine-6G-based chemosensor X was designed and synthesized for the colorimetric and fluorometric detection of Hg

To compare therapeutic effects of three fixation methods with three Kirschner wires,and to find the best fixation method.From July 2008 to May 2009, 60 patients with humeral supracondylar fractures were treated. Among patients in Group A, 11 patients were male and 9 patients were female, ranging from 2 to 13 years old,with an average of (5.4 +/- 0.5)years;all the patients in Group A were fresh closed fractures without nerve and blood vessel injuries, 13 patients were type II and 7 patients were type III according to Gartland classification; and all the patients in Group A were treated by three Kirschner wires fixation with the third Kirschner different wire fixed through radial edge of coronoid fossa. Among patients in Group B, 13 patients were male and 7 patients were female,ranging from 2 to 11 years old, with an average of (6.1 +/- 0.4) years; all the patients in Group B were fresh closed fractures without blood vessel injuries, 11 patients were type II and 9 patients were type III according to Gartland classification, 2 patients had ulnar nerve injuries before treatment; and all the patients in Group B were treated by three Kirschner wires fixation with the third Kirschner different wire fixed through ulnar edge of coronoid fossa. Among patients in Group C, 8 patients were male and 12 patients were female, ranging from 3 to 14 years old, with an average of (7.4 +/- 0.6) years; all the patients in Group C were closed fresh fractures without blood vessel injuries, 7 patients were type II and 13 patients were type III according to Gartland classification, 2 patients had radial nerve injuries before treatment; and all the patients in Group C were treated by three Kirschner wires fixation with the third Kirschner different wire fixed through middle of coronoid fossa. After 1 year of treatment,the Carrying and Baumann angles were measured on the X-ray of all patients in the three groups, and the motion range of elbow joint was observed. The Flynn evaluation criteria were used to compare therapeutic effects among the three groups.All the patients were followed up. The function loss of elbow joint were (14.04 +/- 3.25) degrees in Group A, (13.14 +/- 2.34) degrees in Group B, and (9.25 +/- 2.56) degrees in Group C. Changes of Carrying angle were (7.64 +/- 1.78) degrees in Group A; (7.38 +/- 1.68) degrees in Group B, and (5.27 +/- 1.13) degrees in Group C. Changes of Baumann angle were (28.55 +/- 3.23) degrees in Group A, (27.55 +/- 2.23) degrees in Group B, (21.45 +/- 1.73) degrees in Group C. According to Flynn criteria, there were 11 patients got excellent result, 4 good and 5 poor in Group A; in Group B, 12 patients got excellent result, 3 good and 5 poor; in Group C, 11 patients got excellent result, 6 good and 3 poor. The therapeutic effects of Group C was better than those of Group A and Group B.There are different effects among three kinds of operative approaches for the humerus supracondylar fractures. The fixation method with one Kirschner wire through middle part of coronoid fossa is better than the other two fixation methods.