Analysis of clinicopathological characteristics and prognosis on primary gastric adenosquamous carcinoma.

Primary gastric adenosquamous carcinoma (PGASC) is a rare type of gastric cancer with limited research and poorly understood clinicopathological features. This study investigated the clinicopathological features and outcomes of PGASC. Patients with PGASC from Union Hospital, Tongji Medical College, Huazhong University of Science and Technology and from the published literature were enrolled in this study. Survival curves were generated using the Kaplan-Meier method, and prognostic factors were identified through Cox proportional hazards regression models. This study identified 76 eligible cases of PGASC, with 45 cases from published literature and 31 from our center. The most prevalent symptoms were abdominal pain and dysphagia, with a median age of 62 years (range: 29-84 years). The primary lesions were predominantly in the proximal stomach, with a median tumor size of 6.5 cm (range: 1.5-16.0 cm). Tumor stages II, III, and IV were detected in 12 (16.7%), 43 (59.7%), and 17 (23.6%) patients, respectively. Most tumors were poorly differentiated in both the squamous cell carcinoma (SCC) component and adenocarcinoma (AC) component. The median survival time was 17 months (range: 2-122 months). The 1, 3, and 5-year overall survival (OS) was 60.7%, 31.1%, and 24.1%, respectively. Multivariate analysis revealed that OS was independently predicted by the proportion of SCC component, differentiation of AC component, and tumor stage. PGASC is a rare disease with a poor prognosis. A high proportion of SCC components, low differentiated AC components, and advanced tumor were associated with worse survival in patients with PGASC. Adjuvant therapy did not improve survival time.

Uptake, subcellular distribution, and fate of tetracycline in two wetland plants supplemented with microbial agents: Effect and mechanism.

The use of wetland plants in the context of phytoremediation is effective in the removal of antibiotics from contaminated water. However, the effectiveness and efficiency of many of these plants in the removal of antibiotics remain undetermined. In this study, the effectiveness of two plants-Phragmites australis and Iris pseudacorus-in the removal of tetracycline (TC) in hydroponic systems was investigated. The uptake of TC at the roots of I. pseudacorus and P. australis occurred at concentrations of 588.78 and 106.70 µg/g, respectively, after 7-day exposure. The higher uptake of TC in the root of I. pseudacorus may be attributed to its higher secretion of root exudates, which facilitate conditions conducive to the reproduction of microorganisms. These rhizosphere-linked microorganisms then drove the TC uptake, which was higher than that in the roots of P. australis. By elucidating the mechanisms underlying these uptake-linked outcomes, we found that the uptake of TC for both plants was significantly suppressed by metabolic and aquaporin inhibition, suggesting uptake and transport of TC were active (energy-dependent) and passive (aquaporin-dominated) processes, respectively. The subcellular distribution patterns of I. pseudacorus and P. australis in the roots were different, as expressed by differences in organelles, cell wall concentration levels, and transport-related dynamics. Additionally, the microbe-driven enhancement of the remediation capacities of the plants was studied comprehensively via a combined microbial-phytoremediation hydroponic system. We confirmed that the microbial agents increased the secretion of root exudates, promoting the variation of TC chemical speciation and thus enhancing the active transport of TC. These results contribute toward the improved application of wetland plants in the context of antibiotic phytoremediation.

Extant and extinct bilby genomes combined with Indigenous knowledge improve conservation of a unique Australian marsupial.

Ninu (greater bilby, Macrotis lagotis) are desert-dwelling, culturally and ecologically important marsupials. In collaboration with Indigenous rangers and conservation managers, we generated the Ninu chromosome-level genome assembly (3.66 Gbp) and genome sequences for the extinct Yallara (lesser bilby, Macrotis leucura). We developed and tested a scat single-nucleotide polymorphism panel to inform current and future conservation actions, undertake ecological assessments and improve our understanding of Ninu genetic diversity in managed and wild populations. We also assessed the beneficial impact of translocations in the metapopulation (N = 363 Ninu). Resequenced genomes (temperate Ninu, 6; semi-arid Ninu, 6; and Yallara, 4) revealed two major population crashes during global cooling events for both species and differences in Ninu genes involved in anatomical and metabolic pathways. Despite their 45-year captive history, Ninu have fewer long runs of homozygosity than other larger mammals, which may be attributable to their boom-bust life history. Here we investigated the unique Ninu biology using 12 tissue transcriptomes revealing expression of all 115 conserved eutherian chorioallantoic placentation genes in the uterus, an XY1Y2 sex chromosome system and olfactory receptor gene expansions. Together, we demonstrate the holistic value of genomics in improving key conservation actions, understanding unique biological traits and developing tools for Indigenous rangers to monitor remote wild populations.

Microelectrochemical Sensor Reveals Tunneling Nanotube-Mediated Intercellular Communication of Endothelial Mechanotransduction.

The intercellular communication of mechanotransduction has a significant impact on various cellular processes. Tunneling nanotubes (TNTs) have been documented to possess the capability of transmitting mechanical stimulation between cells, thereby triggering an influx of Ca2+ ions. However, the related kinetic information on the TNT-mediated intercellular mechanotransduction communication is still poorly explored. Herein, we developed a classic and sensitive Pt-functionalized carbon fiber microelectrochemical sensor (Pt/CF) to study the intercellular communication of endothelial mechanotransduction through TNTs. The experimental findings demonstrate that the transmission of mechanical stimulation from stimulated human umbilical vein endothelial cells (HUVECs) to recipient HUVECs connected by TNTs occurred quickly (<100 ms) and effectively promoted nitric oxide (NO) production in the recipient HUVECs. The kinetic profile of NO release exhibited remarkable similarity in stimulated and recipient HUVECs. But the production of NO in the recipient cell is significantly attenuated (16.3%) compared to that in the stimulated cell, indicating a transfer efficiency of approximately 16.3% for TNTs. This study unveils insights into the TNT-mediated intercellular communication of mechanotransduction.

Examining dynamic developmental trends: the interrelationship between age-friendly environments and healthy aging in the Chinese population-evidence from China Health and Retirement Longitudinal Study, 2011-2018.

BACKGROUND: The objective of this research is to investigate the dynamic developmental trends between Age-Friendly Environments (AFE) and healthy aging in the Chinese population. METHODS: This study focused on a sample of 11,770 participants from the CHARLS and utilized the ATHLOS Healthy Aging Index to assess the level of healthy aging among the Chinese population. Linear mixed model (LMM) was used to explore the relationship between AFE and healthy aging. Furthermore, a cross-lagged panel model (CLPM) and a random-intercept cross-lagged panel model (RI-CLPM) were used to examine the dynamic developmental trends of healthy aging, taking into account both Between-Person effects and Within-Person effects. RESULTS: The results from LMM showed a positive correlation between AFE and healthy aging (ß = 0.087, p < 0.001). There was a positive interaction between the geographic distribution and AFE (central region * AFE: ß = 0.031, p = 0.038; eastern region * AFE: ß = 0.048, p = 0.003). In CLPM and RI-CLPM, the positive effect of healthy aging on AFE is a type of Between-Person effects (ß ranges from 0.147 to 0.159, p < 0.001), while the positive effect of AFE on healthy aging is Within-Person effects (ß ranges from 0.021 to 0.024, p = 0.004). CONCLUSION: Firstly, individuals with high levels of healthy aging are more inclined to actively participate in the development of appropriate AFE compared to those with low levels of healthy aging. Furthermore, by encouraging and guiding individuals to engage in activities that contribute to building appropriate AFE, can elevate their AFE levels beyond the previous average level, thereby improving their future healthy aging levels. Lastly, addressing vulnerable groups by reducing disparities and meeting their health needs effectively is crucial for fostering healthy aging in these populations.

Elucidating the role of MICAL1 in pan-cancer using integrated bioinformatics and experimental approaches.

Molecule interacting with CasL 1 (MICAL1) is a crucial protein involved in cell motility, axon guidance, cytoskeletal dynamics, and gene transcription. This pan-cancer study analyzed MICAL1 across 33 cancer types using bioinformatics and experiments. Dysregulated expression, diagnostic potential, and prognostic value were assessed. Associations with tumor characteristics, immune factors, and drug sensitivity were explored. Enrichment analysis revealed MICAL1's involvement in metastasis, angiogenesis, metabolism, and immune pathways. Functional experiments demonstrated its impact on renal carcinoma cells. These findings position MICAL1 as a potential biomarker and therapeutic target in specific cancers, warranting further investigation into its role in cancer pathogenesis.

Template-Assisted Synthesis of 2D Perovskite Grating Single Crystal Films at Low Temperatures for UV Polarization-Sensitive Photodetectors.

2D perovskites have attracted tremendous attention due to their superior optoelectronic properties and potential applications in optoelectronic devices. Especially, the larger bandgap of 2D perovskite means that they are suitable for UV photodetection. However, the layered structure of 2D perovskites hinders the interlayer carrier transport, which limits the improvement of device performance. Therefore, nanoscale structures are normally used to enhance the light absorption ability, which is an effective strategy to improve the photocurrent in 2D perovskite-based photodetectors. Herein, a template-assisted low-temperature method is proposed to fabricate 2D perovskite ((C6H5C2H4NH3)2PbBr4, (PEA)2PbBr4) grating single crystal films (GSCFs). The crystallinity of the (PEA)2PbBr4 GSCFs is significantly improved due to the slow evaporation of the precursor solution under low temperatures. Based on this high crystalline quality and extremely ordered microstructures, the metal-semiconductor-metal photodetectors are assembled. Finite-different time-domain (FDTD) simulation and experiment indicate that the GSCF-based photodetectors exhibit significantly improved performance in comparison with the plane devices. The optimized 2D perovskite photodetectors are sensitive to UV light and demonstrate a responsivity and detectivity of 28.6 mA W-1 and 2.4 × 1011 Jones, respectively. Interestingly, the photocurrent of this photodetector varies as the angle of the incident polarized light, resulting in a high polarization ratio of 1.12.

Ecological risk assessment of the typical anti-epidemic drugs in the Pearl River Delta by tracing their source and residual characteristics.

Since the outbreak of the COVID-19 pandemic, the anti-epidemic drugs have been used in extraordinary quantities with high intensity, and concerns have grown about their potential ecological risks due to their continued release and persistence in the receiving environments. A systematic investigation, covering the samples from hospital wastewater, effluent from wastewater treatment plants and receiving water bodies in the Pearl River Delta Region (PRDR), was carried out and aimed at tracing the sources and fate of 30 typical anti-epidemic in different water matrixes and evaluating their ecological risk. The results showed that these typical anti-epidemic drugs residues were detected in most of the sampling sites, with the highest concentration measured in hospital wastewater, whose concentrations were as high as ppb level, while the highest concentration of the surface water samples in tributaries was lower than ppb level. Anti-epidemic drugs contained in hospital wastewater and effluent from WWTPs were the main sources of drug residues in the surface water of this region. In the surface water of PRDR, although the detected concentration anti-epidemic drugs were basically in the range of 0-10 ng/L. The risk quotient of several anti-epidemic drugs, including Ciprofloxacin (CFX), Ofloxacin (OFX), Erythromycin (ETM), Clindamycin (CLI), and Sulfamethoxazole (SMX), was calculated to be a high value, which indicated that they might cause non-negligible ecological risk to the aquatic environment.

Surface Microstructure Engineering in MAPbBr3 Microsheets for Performance-Enhanced Photodetectors.

Metal halide-perovskite-based photodetectors have recently emerged as a class of promising optoelectronic devices in various fields. Meanwhile, nano/microstructuring perovskite-based photodetectors are a facile integration with complementary metal-oxide semiconductors for miniaturized imaging systems. However, there are still challenges to be overcome in reducing the losses caused by light reflection on the surface of microstructural perovskites. In this work, surface microstructure engineering is employed in MAPbBr3 microsheets for reducing light reflection and improving light absorption, resulting in high-performance perovskite photodetectors. MAPbBr3 microsheets, which possess different surface morphologies of flat, upright hemisphere arrays and inverted hemisphere arrays (IHAs), are fabricated by a simple microstructure template-assisted space confinement process. The light absorption capacity of IHA MAPbBr3 is significantly higher than that of the other two structures. Hence, IHA photodetectors with excellent figures of merit, including low dark current, decent responsivity, and fast speed, are achieved. Furthermore, the noise of the IHA photodetectors is only ∼10-13 A/Hz, which results in the superior sensitivity for weak light detection with a specific detectivity up to 1011 Jones. Our results demonstrate that surface engineering is a simple, low-cost, yet effective approach to improve the performance of nano-/micro-optoelectronic devices.

RESTRICTIVE FLUID RESUSCITATION IN SEPTIC SHOCK PATIENTS HAS LOWER MORTALITY AND ORGAN DYSFUNCTION RATES THAN STANDARD THERAPY.

ABSTRACT: Background : The influence of restrictive fluid resuscitation and the early administration of vasopressors on the clinical outcomes in patients with septic shock are not fully understood. The purpose of this study was to evaluate the effects of restrictive fluid management on mortality and organ dysfunction in patients with septic shock. Methods : This study included consecutive patients with septic shock in need of fluid resuscitation. Based on the fluid management provided in the initial resuscitation phase, a comparison was made between a restrictive group and a standard fluid management group. The primary outcome was in-hospital death, whereas secondary outcomes included organ dysfunction and other adverse events. Results : A total of 238 patients were included in this study. Restrictive fluid management was administered to 59.2% of patients, whereas 40.8% received standard fluid management. Restrictive resuscitation was associated with a lower in-hospital mortality rate (24.8% vs. 52.6%), as well as a shorter median intensive care unit stay (8.0 vs. 11.0 days). The restrictive strategy was associated with a significantly lower prevalence of new-onset acute kidney injury (25.5% vs. 51.5%) and a decrease in the incidence of renal replacement therapy (20.6% vs. 40.2%). The standard group had a higher risk of the need for mechanical ventilation and a significantly lower median number of days without a ventilator than the restrictive group. The median duration of vasopressor-free days in the restrictive group was significantly longer than that in the standard group (25.0 vs. 18.0). The administration rate of inotropes in the restrictive group was significantly lower than that in the standard group. A multivariate logistic regression model showed that restrictive fluid management (odds ratio [OR], 0.312; 95% confidence interval [CI], 0.098-0.994) and vasopressor-free days (OR, 0.807; 95% CI, 0.765-0.851) protect against in-hospital death, whereas Acute Physiology and Chronic Health Evaluation II scores (OR, 1.121; 95% CI, 1.018-1.234) were independent risk factors for in-hospital death. Conclusions : Restrictive fluid resuscitation and early vasopressor protocol in patients with septic shock are associated with better outcomes, indicating that this regimen is feasible and safe.

Differentially expressed miR-127, miR-150, and miR-145 in serum extracellular vesicles are novel diagnostic biomarkers of unstable angina.

Background: Specific and sensitive diagnostic biomarkers for unstable angina (UA) are currently scarce. The diagnosis of UA usually relies on medical history and physician experience. This study aimed to analyze the expression profiles of microRNAs (miRNAs) in the serum extracellular vesicles (EVs) of UA patients, thus identifying potential diagnostic biomarkers of UA. Methods: This study is a prospective study and participants were recruited randomly. A total of 142 patients with UA, 8 with non-ST-elevation myocardial infarction (NSTEMI), and 8 with stable angina (SA) at Nanjing Hospital of Traditional Chinese Medicine Affiliated with Nanjing University of Chinese Medicine from January 2019 to February 2022 were recruited. Fifty-eight healthy volunteers (HVs) were recruited to the control group during the same period. Differentially expressed miRNAs in serum exosomes of UA patients were first identified by high-throughput sequencing, followed by verification via quantitative reverse transcription polymerase chain reaction (qRT-PCR), and Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses. Our findings aim to explore their diagnostic potentials in UA, and their biological functions, as well as the correlation between conventional biochemical indexes of UA. Results: MiR-127, miR-150, and miR-145 were differentially expressed miRNAs in the serum EVs of 8 UA patients, 8 NSTEMI patients, 8 SA patients, and 8 HVs by high-throughput sequencing, which were downregulated in UA patients versus HVs. Moreover, the relative levels of differentially expressed miRNAs in the serum EVs of the remaining UA patients and HVs were measured by qRT-PCR. The area under the curve of miR-127, miR-150, and miR-145 in distinguishing UA patients from HVs was 0.872, 0.856, and 0.803, respectively. Notably, the area under the curve of the combination of the three differentially expressed miRNAs for diagnosing UA was 0.944. A GO analysis revealed that miR-127, miR-150, and miR-145 were mainly enriched in cell adhesion and migration, whereas KEGG pathway enrichment analysis showed that they were enriched in the PI3K-Akt, MAPK, and Hippo signaling pathways. Multivariable logistic regression analysis identified cardiac troponin I (cTnI) (P=0.0006), miR-127 (P=0.0001), miR-150 (P=0.0004), and miR-145 (P=0.0005) as independent risk factors for UA. Spearman's rank correlation test showed a significant correlation between cTnI and miR-127 (r=0.1988, P=0.0067). Conclusions: MiR-127, miR-150, and miR-145 in serum EVs are closely linked with UA and serve as novel diagnostic biomarkers.

Simultaneous detection of multiple influenza virus subtypes based on microbead-encoded microfluidic chip.

Influenza virus, existing many subtypes, causes a huge risk of people health and life. Different subtypes bring a huge challenge for detection and treatment, thus simultaneous detection of multiple influenza virus subtypes plays a key role in fight against this disease. In this work, three kinds of influenza virus subtypes are one-step detection based on microbead-encoded microfluidic chip. HIN1, H3N2 and H7N3 were simultaneously captured only by microbeads of different magnetism and sizes, and they were further treated by magnetic separation and enriched through the magnetism and size-dependent microfluidic structure. Different subtypes of influenza virus could be linearly encoded in different detection zones of microfluidic chip according to microbeads of magnetism and size differences. With the high-brightness quantum dots (QDs) as label, the enriched fluorescence detection signals were further read online from linearly encoded strips, obtaining high sensitivity with detection limit of HIN1, H3N2, H7N3 about 2.2 ng/mL, 3.4 ng/mL and 2.9 ng/mL. Moreover, a visual operation interface, microcontroller unit and two-way syringe pump were consisted of a miniaturized detection device, improving the detection process automation. And this assay showed strong specificity. This method improves a new way of multiple pathogens detection using microbead-encoded technologies in the microfluidic chip.

Mechanistic insights into the leaching and environmental safety of arsenic in ceramsite prepared from fly ash.

Utilizing fly ash to prepare ceramsite is a promising way to immobilize heavy metals and recycle industrial solid waste. However, traditional preparation method of fly ash ceramsite has the disadvantages of large ignition loss. Therefore, the present study applied the pressure molding method to enhance solid content and improve the strength of ceramsite. The optimal preparation conditions of ceramsite were suggested as preheating at 450 °C for 25 min followed by sintering at 1050 °C for 30 min. Under such conditions, ceramsite with high compressive strength of 10.8 Mpa, bulk density of 878 kg m-3, and 1-h water absorption of 18.5% was fabricated, in compliance with Chinese standard (GB/T 1743.1-2010). The arsenic leaching concentration from the resulting product was considerably lower than Chinese standard (GB 5085.3-2007). Moreover, arsenic volatilization during ceramsite calcination was insignificant, and the vast majority of arsenic remained in resulting ceramsite. A geochemical speciation model developed for the multiple component system in ceramsite suggested that FeAsO4, Ca5(OH) (AsO4)3, and hydrous ferric oxide adsorption are the primary mechanisms retaining arsenic in ceramsite. Additionally, based on density functional theory calculations and biotoxicity test, the binding site of arsenic atom on mineral components and the environmental safety of ceramsite was determined and evaluated.

Perineal wound complications after vertical rectus abdominis myocutaneous flap and mesh closure following abdominoperineal surgery and pelvic exenteration of anal and rectal cancers: A meta-analysis.

A meta-analysis research was implemented to appraise the perineal wound complications (PWCs) after vertical rectus abdominis myocutaneous (VRAM) flap and mesh closure (MC) following abdominoperineal surgery (AS) and pelvic exenteration (PE) of anal and rectal cancers. Inclusive literature research till April 2023 was done and 2008 interconnected researches were revised. Of the 20 picked researches, enclosed 2972 AS and PE of anal and rectal cancers persons were in the utilized researchers' starting point, 1216 of them were utilizing VRAM flap, and 1756 were primary closure (PC). Odds ratio (OR) and 95% confidence intervals (CIs) were utilized to appraise the consequence of VRAM flap in treating AS and PE of anal and rectal cancers by the dichotomous approach and a fixed or random model. VRAM flap had significantly lower PWCs (OR, 0.64; 95% CI, 0.42-0.98, p < 0.001), and major PWCs (OR, 0.50; 95% CI, 0.32-0.80, p = 0.004) compared to PC in AS and PE of anal and rectal cancers persons. However, VRAM flap and PC had no significant difference in minor PWCs (OR, 1; 95% CI, 0.54-1.85, p = 1.00) in AS and PE of anal and rectal cancer persons. VRAM flap had significantly lower PWCs, and major PWCs, however, no significant difference was found in minor PWCs compared to PC in AS and PE of anal and rectal cancers persons. However, caution needs to be taken when interacting with its values since there was a low sample size of most of the chosen research found for the comparisons in the meta-analysis.

Recovery of valuable metals from spent lithium-ion batteries through biomass pyrolysis gas-induced reduction.

The development of spent lithium-ion batteries (LIBs) recycling technologies can effectively alleviate environmental pressure and conserve metal resources. We propose a win-win strategy for pyrolysis gas reduction by lignocellulosic biomass, ensuring gas-induced reduction by spatial isolation of biomass and lithium transition metal oxides (LiTMOX (TM = Ni, Co, Mn)), and avoiding the separation of solid carbon and TMOX (TM = Ni, Co, Mn). In the spent LiCoO2 batteries, the lithium recovery efficiency reaches 99.99% and purity reaches 98.3% at 500 °C. In addition, biomass pyrolysis gas reduction is also applicable to treat spent LiMn2O4 and LiNi0.6Co0.2Mn0.2O2 batteries. Thermodynamic analysis verifies that CO dominates the gas reduction recovery process. DFT calculation indicates that the gas reduction induces the collapse of the oxygen framework of LiTMOX (TM = Ni, Co, Mn). Everbatt-based economic and environmental analysis illustrates that this is an environment-friendly and energy-saving method.

Three-dimensional heterogeneous electro-Fenton system with reduced graphene oxide based particle electrode for Acyclovir removal.

New pollutant pharmaceutical and personal care products (PPCPs), especially antiviral drugs, have received increasing attention not only due to their increase in usage after the outbreak of COVID-19 epidemics but also due to their adverse impacts on water ecological environment. Electro-Fenton technology is an effective method to remove PPCPs from water. Novel particle electrodes (MMT/rGO/Fe3O4) were synthesized by depositing Fe3O4 nanoparticles on reduced graphene oxide modified montmorillonite and acted as catalysts to promote oxidation performance in a three-dimensional Electro-Fenton (3D-EF) system. The electrodes combined the catalytic property of Fe3O4, hydrophilicity of montmorillonite and electrical conductivity of graphene oxides, and applied for the degradation of Acyclovir (ACV) with high efficiency and ease of operation. At optimal condition, the degradation rate of ACV reached 100% within 120 min, and the applicable pH range could be 3 to 11 in the 3D-EF system. The stability and reusability of MMT/rGO/Fe3O4 particle electrodes were also studied, the removal rate of ACV remained at 92% after 10 cycles, which was just slightly lower than that of the first cycle. Potential degradation mechanisms were also proposed by methanol quenching tests and FT-ICR-MS.

Direct synthesis of alkylated 4-hydroxycoumarin derivatives via a cascade Cu-catalyzed dehydrogenation/conjugate addition sequence.

An efficient approach for the direct synthesis of alkylated 4-hydroxycoumarin derivatives via a Cu-catalyzed cascade dehydrogenation/conjugate addition sequence starting from simple saturated ketones and 4-hydroxycoumarins has been developed. This protocol features excellent functional-group tolerance, easy scale-up, and a broad substrate scope including bioactive molecules. More importantly, a series of marketed drugs, such as warfarin, acenocoumarol, coumachlor, and coumafuryl, can be obtained by this method.

Silicon facilitated the physical barrier and adsorption of cadmium of iron plaque by changing the biochemical composition to reduce cadmium absorption of rice roots.

Silicon effectively inhibits cadmium (Cd) uptake in rice, iron plaque on root surface was the primary link and first interface of Cd entering into rice root. To elucidate the mechanism of iron plaque under silicon treatment on root Cd uptake, the morphological characteristics of iron plaque, mechanisms of Cd adsorption of iron plaque and effect of iron plaque on Cd uptake by rice roots of Yuzhenxiang (YZX) and Xiangwanxian (XWX) rice varieties were studied by employing energy spectrum analysis technique, non-invasive micro-test technique, and isothermal-kinetic adsorption method. Scanning electron microscopy-X-ray energy dispersive (SEM-EDX) analysis showed that denser crystal structure of iron plaque was observed at Si treatment, silicon promoted the thickening of iron plaque and strengthened the isolation of iron plaque to Cd, which reduced the Cd content of white roots of YZX and XWX varieties by 30.2% and 20.9% respectively. However, the blocking effect of iron plaque on Cd was weakened under silicon treatment with iron plaque removed, Cd content in iron plaque of YZX and XWX cultivars was significantly decreased by 36.3% and 18.4%, Cd concentrations in white root and shoot was significantly increased, and the influxes of Cd2+ at elongation and maturation zone of root were increased in multiples. The results of adsorption test showed that the adsorption process of iron plaque was mainly a monolayer adsorption completed by boundary diffusion. The X-ray photoelectron spectroscopy (XPS) results demonstrated that silicon changed the biochemical composition of iron plaque and increased the density of the carbon-oxygen bound groups on iron plaque, which is the most likely reasons for the higher affinity of Cd adsorption ability of iron plaque observed in the silicon treated iron plaque. This study suggested the silicon-facilitated iron plaque have played critical effects in controlling the Cd accumulation in rice roots by changing the morphology and chemical composition of iron plaque.

Evaluating the impact of drying on leaching from a solidified/stabilized waste using a monolithic diffusion model.

The release rates of constituents of potential concern from solidified/stabilized cementitious waste forms are potentially impacted by drying, which, however, is not well understood. This study aimed to identify the impacts of drying on subsequent leaching from Cast Stone as an example of a solidified cementitious waste form. The release fluxes of constituents from monoliths after aging under 100, 68, 40, and 15 % relative humidity for 16, 32, and 48 weeks, respectively, were derived from mass transfer tank leaching tests following EPA Method 1315. A monolithic diffusion model was calibrated based on the leaching test results to simulate the leaching of major and redox-sensitive constituents from monoliths after drying. The reduction in physical retention of constituents (tortuosity-factor) in the unsaturated zone was identified as the primary impact from drying on subsequent leaching. Fluxes of both major (i.e., OH-, Na, K, Ca, Si, and Al) and redox-sensitive constituents (i.e., Tc, Cr, Fe, and S) from monoliths during leaching were well described by the model. The drying-induced reduction of tortuosity-factor and concomitant changes in porewater pH and redox conditions can significantly change the subsequent release fluxes of pH- and redox- sensitive constituents.