Development of a continuous electrochemical reactor incorporated with waste-derived activated carbon electrode for the effective removal of hexavalent chromium from industrial effluent.

Being a recognized carcinogen, hexavalent chromium is hazardous to both human and environmental health. Thus, it is imperative to regulate and oversee their levels in a variety of industries, including textiles, dyes, pigments, and metal finishing. This study strives to reduce Cr(VI) in wastewater by using capacitive deionization in conjunction with an activated carbon-based electrode and a continuous electrochemical reactor (CER). Activated carbon derived from rubberwood sawdust demonstrated excellent properties, including a high surface area of 1157 m2 g-1. The electrical conductivity and mechanical stability of the electrode were enhanced by the incorporation of synthesized expanded graphite (EG) into the AC. Key parameters were optimized via systematic batch electroreduction experiments with an optimal response surface design. The efficacy of the fabricated CER was proved when it successfully reduced Cr(VI) in a 5 mg L-1 solution within 15 min under optimized conditions, in contrast to the considerably longer durations anticipated by conventional methods. Validation of these findings was done by treating industrial wastewater of 30 mg L-1 in the CER. The electroreduction of Cr(VI) followed the Langmuir isotherm with a maximum capacity of 13.491 mg g-1 and pseudo-second-order kinetics. These results indicate that the combined use of the modified AC electrode and CER holds potential as a sustainable and economical approach to effectively eliminate Cr(VI) from wastewater.

Organizational and Infrastructural Risk Factors for Healthcare-associated Clostridioides difficile Infections or Methicillin-resistant Staphylococcus aureus in Hospitals.

OBJECTIVE: This study explores the infrastructural and organizational risk factors for healthcare-associated (HCA) Clostridioides difficile Infections (CDI) and Methicillin-resistant Staphylococcus aureus (MRSA) in hospitals. METHODS: This is a retrospective observational study involving all eligible inpatient units from 12 hospitals in British Columbia, Canada from April 1, 2020 to September 16, 2021. The outcomes were the average HCA CDI or MRSA rates. Covariates included, but were not limited to, infection control factors (e.g., hand hygiene rate), infrastructural factors (e.g., unit age), and organizational factors (e.g., hallway bed utilization). Multivariable regression was performed to identify statistically significant risk factors. RESULTS: Older units were associated with higher HCA CDI rate (Adjusted Relative Risk (aRR): 0.012; 95%CI [0.004, 0.020]). Higher HCA MRSA rates were associated with decreased hand hygiene rate (aRR: -0.035; 95%CI [-0.063, -0.008]), higher MRSA bioburden (aRR: 9.008; 95%CI [5.586, 12.429]), increased utilization of hallway beds (aRR: 0.680; 95%CI [0.094, 1.267]), increased nursing overtime rate (aRR: 5.018; 95%CI [1.210, 8.826]), and not keeping the clean supply room door closed (aRR: -0.283; 95%CI [-0.536, -0.03]). CONCLUSIONS: The study confirmed the multifaceted nature to infection prevention and emphasized the importance of interdepartmental collaboration to improve patient safety.

Development of two recombinant vaccines against Clostridioides difficile infection and immunogenicity in pregnant sows and neonatal piglets.

INTRODUCTION: Clostridioides difficile is the main cause of antibiotic-associated diarrhea in humans and is a major enteropathogen in several animal species. In newborn piglets, colonic lesions caused by C. difficile A and B toxins (TcdA and TcdB, respectively) cause diarrhea and significant production losses. OBJECTIVE: The present study aimed to develop two recombinant vaccines from immunogenic C-terminal fragments of TcdA and TcdB and evaluate the immune response in rabbits and in breeding sows. Two vaccines were produced: bivalent (rAB), consisting of recombinant fragments of TcdA and TcdB, and chimeric (rQAB), corresponding to the synthesis of the same fragments in a single protein. Groups of rabbits were inoculated with 10 or 50 µg of proteins adjuvanted with aluminum or 0.85 % sterile saline in a final volume of 1 mL/dose. Anti-TcdA and anti-TcdB IgG antibodies were detected in rabbits and sows immunized with both rAB and rQAB vaccines by ELISA. The vaccinated sows were inoculated intramuscularly with 20 µg/dose using a prime-boost approach. RESULTS: Different antibody titers (p ≤ 0.05) were observed among the vaccinated groups of sows (rAB and rQAB) and control. Additionally, newborn piglets from vaccinated sows were also positive for anti-TcdA and anti-TcdB IgGs, in contrast to control piglets (p ≤ 0.05). Immunization of sows with the rQAB vaccine conferred higher anti-TcdA and anti-TcdB responses in piglets, suggesting the superiority of this compound over rAB. CONCLUSION: The synthesized recombinant proteins were capable of inducing antibody titers against C. difficile toxins A and B in sows, and were passively transferred to piglets through colostrum.

Pangenome Analysis Reveals Novel Contact-Dependent Growth Inhibition System and Phenazine Biosynthesis Operons in Proteus mirabilis BL95 That Are Located in An Integrative and Conjugative Element.

Proteus mirabilis is a leading cause of urinary tract infections and a common commensal of the gastrointestinal tract. Our recent study (JB) showed that P. mirabilis strain BL95 employs a novel contact-dependent killing system against enteric bacteria in the mouse gut and in vitro. To uncover the genetic determinants of this system, we performed whole-genome sequencing of BL95 and compared it with 98 complete genomes of P. mirabilis. BL95 carries 56 coding sequences (CDSs) not found in other P. mirabilis. Over half of these unique genes are located on a novel integrative conjugative element (ICE) named ICEPm2, inserted in tRNA-Phe and exclusive to BL95. ICEPm2 has integration, conjugation, and DNA replication modules nearly identical to ICEPm1 (common in P. mirabilis), but ICEPm2 of BL95 carries two unique operons for P. mirabilis-a phenazine biosynthesis and a contact-dependent growth inhibition (CDI) system. ICEPm2 is absent in the P. mirabilis (AR_0156) closest to BL95 and it is present in the genomes of several Escherichia coli from mouse intestines, indicating its recent horizontal mobilization. BL95 shares over 100 genes of five different secretion systems with other P. mirabilis, mostly poorly studied, making a large pool of candidate genes for the contact-dependent growth inhibition.

Impact of an Intervention Program on Clostridioides difficile Infections: Comparison of 2 Hospital Cohorts.

Background: Clostridioides difficile infection (CDI) occurs in various contexts and care settings and is managed by multiple specialists who are not experts in its management. While there are many initiatives to improve the diagnosis and avoid overdiagnosis, there is less focus on the overall management of the infection. Methods: We studied a cohort of patients with a positive test result for toxigenic C difficile in 2 hospitals. Hospital A has a program that provides advice from an infectious disease specialist (IDS) and promotes continuity of care by providing a phone number to contact the IDS. Hospital B does not have any specific CDI program. The evaluation assessed the proportion of patients not treated (carriers or self-limited disease), adherence to Infectious Diseases Society of America guidelines, access to novel therapies, recurrence and mortality rates, and readmission and emergency department visits due to CDI. We assessed the program's effectiveness through a logistic regression model adjusted for covariates chosen by clinical criteria. Results: Hospital A avoided more unnecessary treatments (19.3% vs 11.5%), provided access to novel therapies more frequently (35.3% vs 13%), and adhered more closely to current guidelines (95.8% vs 71.3%). Although the mortality and recurrence rates did not differ, the absence of an intervention program was associated with greater odds of admission due to recurrence (odds ratio, 4.19; P = .037) and more visits to the emergency department due to CDI (odds ratio, 8.74; P = .001). Conclusions: Implementation of a CDI intervention program based on recommendations from IDSs and improved access to specialized care during the follow-up is associated with enhanced quality of CDI management and potential reductions in hospital resource utilization.

Ion-Selective Metathesis Design of Flow-Electrode Capacitive Deionization for Energy-Saving and Anti-Scaling Softening of Brackish Water.

While flow-electrode capacitive deionization (FCDI) is recognized as an attractive desalination technology, its practical implementation has been hindered by the ease of scaling and energy-intensive nature of the single-cell FCDI system, particularly when treating brackish water with elevated levels of naturally coexisting SO42- and Ca2+. To overcome these obstacles, we propose and design an innovative ion-selective metathesis FCDI (ISM-FCDI) system, consisting of a two-stage tailored cell design. Results indicate that the specific energy consumption per unit volume of water for the ISM-FCDI is lower (by up to ∼50%) than that of a conventional single-stage FCDI due to the parallel circuit structure of the ISM-FCDI. Additionally, the ISM-FCDI benefits from a conspicuous disparity in the selective removal of ions at each stage. The separate storage of Ca2+ and SO42- by the metathesis process in the ISM-FCDI (46.25% Ca2+, 14.25% SO42- in electrode 1 and 4.75% Ca2+, 35.25% SO42- in electrode 2) can effectively prevent scaling. Furthermore, configuration-performance analysis on the ion-selective migration suggests that the properties of the ion exchange membrane, rather than the carbon species, govern the selectivity of ion removal. This work introduces system-level enhancements aimed at enhancing energy conservation and scaling prevention, providing critical optimization of the FCDI for brackish water softening.

Comparative Efficacy of Fecal Microbiota Transplantation in Treating Refractory or Recurrent Clostridioides difficile Infection among Patients with and without Inflammatory Bowel Disease: A Retrospective Cohort Study.

Clostridioides difficile infection (CDI) worsens inflammatory bowel disease (IBD) prognosis. While fecal microbiota transplantation (FMT) is effective for refractory or recurrent CDI (rrCDI), comparative success rates between IBD and non-IBD patients are scarce. This study addresses this gap. A retrospective cohort study was conducted at Chang Gung Memorial Hospital from April 2019 to October 2023. Patients receiving FMT for rrCDI were categorized into IBD and non-IBD groups. Baseline characteristics and outcomes were compared at one month and one year, with successful FMT defined as the resolution of diarrhea without CDI recurrence. The study included 88 patients: 30 with IBD and 58 without IBD. The IBD group was younger, with fewer comorbidities. Success rates at one month were similar between groups (IBD: 80.0% vs. non-IBD: 78.9%, p = 0.908), as were negative toxin tests (IBD: 83.3% vs. non-IBD: 63.8%, p = 0.174). One-year success rates (IBD: 70.0% vs. non-IBD: 67.6%, p = 0.857) and eradication rates (IBD: 94.4% vs. non-IBD: 73.9%, p = 0.112) were also similar. Poor bowel preparation predicted FMT failure at one month (OR = 0.23, p = 0.019). No safety issues were reported. FMT is a safe, effective treatment for rrCDI, demonstrating similar success rates in patients with and without IBD.

[Spatial Differentiation Characteristics and Influencing Factors of Surface Soil Cd in Karst Plateau Area of Guiyang City].

In order to explore the spatial differentiation characteristics and variation law of soil Cd content in a high geological background area, 14 421 topsoil samples were collected from topsoil in the karst area of Guiyang City. Global Moran's I index, cold hot spot analysis, semi-variance function, and Kriging interpolation were used to reveal the spatial structure and distribution law of soil Cd content. The influence of environmental factors on soil Cd content and its main controlling factors were analyzed through analysis of variance and geographic detector. The results showed that： ① The Cd content of karst surface soil in Guiyang varied from 0.03 to 1.36 mg·kg-1, with an average of 0.440 mg·kg-1, which was 1.77 times and 5.95 times the Guizhou soil Cd background value and Chinese soil Cd background value, respectively. The over-standard rate of soil Cd was 30%, which was 4.29 times that of 7% of soil Cd in China. ② There was a significant spatial positive correlation of soil Cd content, showing an aggregation trend in the global space, whereas in the local region, the northeast and southwest were hot spots, and the north was a cold spot. The nugget coefficient of soil Cd content was 10.37%, indicating that soil Cd was mainly affected by structural factors. ③ In terms of spatial distribution, soil Cd showed different accumulation trends. In some massive soils, such as Xifeng County, Xiuwen County, Qingzhen City, Huaxi District, and Nanming District, the soil ω（Cd）was less than 0.3 mg·kg-1. The soil ω（Cd）was between 0.3 and 0.6 mg·kg-1,and soil Cd in Baiyun District, Wudang District, Guanshan Lake area, and Yunyan area as a whole lied within this range. The soil ω（Cd）between 0.6 and 0.9 mg·kg-1 was concentrated in the southwest of Qingzhen City, the south of Huaxi District, and the north of Kaiyang County, whereas soil ω（Cd） between 0.9 and 1.2 mg·kg-1 was mainly concentrated in the southwest of Qingzhen City. The extreme value of soil Cd content （ > 1.2 mg·kg-1） was mostly distributed in Kaiyang County, Xiuwen County, Qingzhen City, and Huaxi District. ④ The results of analysis of variance and geo-detector showed that different environmental factors had significant effects on the spatial differentiation of soil Cd, but their explanatory power on soil Cd content varied： stratum （0.176 5） > soil type （0.026 0） > organic matter （0.025 1） > altitude （0.010 5） > parent rock （0.007 3） > land use （0.006 4） > pH （0.001 3）, and the interaction between stratum and arbitrary environmental factors was the greatest. Therefore, stratum was the main factor affecting the spatial differentiation of soil Cd content.

Depressive symptoms in children and adolescents with epilepsy and primary headache: a cross-sectional observational study.

Background: The primary aims of our cross-sectional observational study were: (i) to determine the prevalence of depressive symptoms in children and adolescents with epilepsy compared to controls and (ii) to explore the difference in depressive symptoms in patients with epilepsy only and those with epilepsy and primary headache as a comorbidity. The secondary objective was to explore parental stress levels. Methods: 68 pediatric patients aged 6-18 years (44 with epilepsy only and 24 with epilepsy and headache) and 50 controls were recruited. Depressive profile and parental stress were assessed using Children's Depression Inventory, Second Edition (CDI-2) and Parenting Stress Index-Short Form (PSI-SF). Results: The group with epilepsy showed significantly high depressive symptoms and parental stress compared to controls. The patients with headache in comorbidity experienced more depressive symptoms than those with epilepsy only. Conclusion: Depressive symptoms are more prevalent in patients who have comorbid epilepsy and primary headache; therefore, the neurological/psychological mechanisms underlying this condition should be further investigated. The simultaneous presence of epilepsy, headache and depressive symptoms impacts the quality of life of patients and their parents, increasing parental stress and family management.

Island biogeography theory provides a plausible explanation for why larger vertebrates and taller humans have more diverse gut microbiomes.

Prior work has shown a positive scaling relationship between vertebrate body size, human height, and gut microbiome alpha diversity. This observation mirrors commonly observed species area relationships (SARs) in many other ecosystems. Here, we expand these observations to several large datasets, showing that this size-diversity scaling relationship is independent of relevant covariates, like diet, body mass index, age, sex, bowel movement frequency, antibiotic usage, and cardiometabolic health markers. Island biogeography theory (IBT), which predicts that larger islands tend to harbor greater species diversity through neutral demographic processes, provides a simple mechanism for positive SARs. Using a gut-adapted IBT model, we demonstrated that increasing the length of a flow-through ecosystem led to increased species diversity, closely matching our empirical observations. We delve into the possible clinical implications of these SARs in the American Gut cohort. Consistent with prior observations that lower alpha diversity is a risk factor for Clostridioides difficile infection (CDI), we found that individuals who reported a history of CDI were shorter than those who did not and that this relationship was mediated by alpha diversity. We observed that vegetable consumption had a much stronger association with CDI history, which was also partially mediated by alpha diversity. In summary, we find that the positive scaling observed between body size and gut alpha diversity can be plausibly explained by a gut-adapted IBT model, may be related to CDI risk, and vegetable intake appears to independently mitigate this risk, although additional work is needed to validate the potential disease risk implications.

Real-world Effectiveness of Fecal Microbiota Transplantation for First or Second Clostridioides difficile Infection.

BACKGROUND & AIMS: Clostridioides difficile infection (CDI) is associated with high mortality. Fecal microbiota transplantation (FMT) is an established treatment for recurrent CDI, but its use for first or second CDI remains experimental. We aimed to investigate the effectiveness of FMT for first or second CDI in a real-world clinical setting. METHODS: This multi-site Danish cohort study included patients with first or second CDI treated with FMT from June 2019 to February 2023. The primary outcome was cure of C. difficile-associated diarrhea (CDAD) 8 weeks after the last FMT treatment. Secondary outcomes included CDAD cure 1 and 8 weeks after the first FMT treatment and 90-day mortality following positive C. difficile test. RESULTS: We included 467 patients, with 187 (40%) having their first CDI. The median patient age was 73 years (interquartile range [IQR], 58-82 years). Notably, 167 (36%) had antibiotic-refractory CDI, 262 (56%) had severe CDI, and 89 (19%) suffered from fulminant CDI. Following the first FMT treatment, cure of CDAD was achieved in 353 patients (76%; 95% confidence interval [CI], 71%-79%) at week 1. At week 8, 255 patients (55%; 95% CI, 50%-59%) maintained sustained effect. In patients without initial effect, repeated FMT treatments led to an overall cure of CDAD in 367 patients (79%; 95% CI, 75%-82%). The 90-day mortality was 10% (95% CI, 8%-14%). CONCLUSION: Repeated FMT treatments demonstrate high effectiveness in managing patients with first or second CDI. Forwarding FMT in CDI treatment guidelines could improve patient survival. CLINICALTRIALS: gov, Number: NCT03712722.

The relationship between vocabulary and grammar in two children with 5p deletion syndrome.

5p deletion syndrome is a rare genetic condition associated with severe speech and language problems. In general, research on speech and language skills is scarce, but there is more knowledge on phonetic and phonological skills than on lexical and grammatical skills. And till now no studies have addressed the relationship between grammar and vocabulary. Therefore, in this study, we address aspects of this relation based on longitudinal parent-reported data (MacArthur-Bates Communicative Development Inventories) from two children with this syndrome aged 2;0-7;3, and 1;11-7;1, respectively. We examine the development of the vocabulary size in each child, seen in relation to the development of grammar (inflections, combinations of words, complexity, and productivity), and see to what extent they can be compared to typically developing children. Results show that they follow a similar pattern to typically developing children but are delayed and have slightly different individual profiles.

Alternative treatment of recurrent Clostridioides difficile infection in adults by fecal transplantation: an overview of phase I-IV studies from Clinicaltrials.gov.

Background: Fecal microbiota transplantation (FMT) is an interventional approach to treat chronic and recurrent Clostridioides difficile infection (CDI). However, there is insufficient evidence regarding its effectiveness and safety. Clinical trials have been conducted to inspect the safety and effectiveness of FMT with and without comparison to pharmacological treatments. Aim: This review explored the treatment of CDI in adults using FMT and evaluated the safety of this intervention based on phase I-IV studies registered on Clinicaltrials.gov. Method: A comprehensive search of Clinicaltrials.gov was conducted to identify relevant studies that investigated CDI in adults. Data on study type, study design, sample size, intervention details, and outcomes related to FMT were examined and evaluated. Results: In total, 13 clinical trials on FMT for CDI published through 17 November 2023 were identified, all of which were interventional studies. The investigation focused on both terminated and completed studies. Basic and advanced outcome measures were examined. Conclusion: Some studies were terminated during phase II, and FMT was less effective than antibiotics such as vancomycin and fidaxomicin. However, colonoscopy and oral FMT were explored in several completed studies with promising results, but the evidence remains limited and inconclusive.

Lexical development in Kuwaiti Arabic in typically developing children and late talkers.

INTRODUCTION: This study explored vocabulary development and lexical composition in young typically developing (TD) Kuwaiti children and late talkers (LT) using the Kuwaiti Arabic Communicative Development Inventory-Words and Sentences (KACDI-WS) Abdalla et al., 2016). The sample included 161 children aged 20 to 37 months: 127 TD and 34 children who were late talkers (LT group). The late talkers were first identified based on a background questionnaire answered by the parents. All the caregivers completed a 698-item web-based KACDI expressive vocabulary inventory by selecting non-imitative words that their children produced. RESULTS: Lexical size and composition (nouns, predicates, and closed-class words) were analyzed. Across the TD age groups (20-26, 27-31, 32-37 months), a significant age effect for vocabulary size and composition was found in favor of the older groups. Nouns were more prevalent than predicates or closed-class words in within-group comparisons. The vocabulary size of the TD (M= 263.8) was significantly larger than that of the LT group (M= 69.2). The development of their lexical composition followed a similar pattern. CONCLUSIONS: The results suggested that the KACDI parent report instrument has the potential for measuring vocabulary development in TD children and could serve as an initial screening tool to identify late talkers.

Incidence, Clinical Characteristics, and Outcomes of Clostridium difficile Infection in a Tertiary Care Center in Bahrain.

Background Clostridioides difficile infection (CDI) represents a significant healthcare challenge associated with antibiotic use and healthcare settings. While healthcare facility-onset CDI (HO-CDI) rates have been extensively studied, the incidence and risk factors of CDI in various settings, including the community, require further investigation. Aim This study aims to examine the incidence rates of CDI in a major governmental hospital in Bahrain, identify risk factors for CDI, and assess the effectiveness of infection control measures. Method We conducted a retrospective study at the Salmaniya Medical Complex (SMC), analyzing all confirmed cases of CDI over a 30-month period from January 2021 to June 2023. CDI cases were screened using glutamine dehydrogenase antigen detection and confirmed using molecular assays like polymerase chain reaction and/or toxin assays for confirmation. The study categorized CDI cases based on their onset (hospital or community) and explored associated risk factors, including antibiotic use, proton pump inhibitor (PPI) therapy, and patient demographics. Infection control practices were also evaluated for their role in managing CDI. Results About 57 new CDI cases were identified during the study period, with a HO-CDI incidence rate of 0.5 per 10,000 patient days. While HO-CDI rates remained stable, community-onset (CO)-CDI cases increased. The median patient age was 61.8 years, without notable differences between genders. Key risk factors for CDI were antimicrobial therapy, use of acid-reducing agents, age, and underlying comorbidities. The mortality rate stood at 35.1%. The ATLAS score (i.e., age, treatment with antibiotics, leukocyte count, albumin level, and serum creatinine) was a reliable predictor of mortality. Critical care admission and low albumin levels emerged as significant independent risk factors for mortality. Conclusions The study demonstrates a low incidence rate of HO-CDI at SMC, attributed to effective infection control and antibiotic stewardship programs. The overall CDI rate increased during the study period, driven by a rise in CO cases; further investigating the risk factors among this category in our study revealed that most patients were exposed to antibiotic therapy within the past three months of their CDI diagnosis. The rise in CO-CDI cases underscores the need for broader community-based interventions and awareness regarding antibiotic and PPI use.

Advances in Therapeutic Strategies for the Management of Clostridioides difficile Infection.

The infection caused by Clostridioides difficile represents one of the bacterial infections with the greatest increase in incidence among nosocomial infections in recent years. C. difficile is a Gram-positive bacterium able to produce toxins and spores. In some cases, infection results in severe diarrhoea and fulminant colitis, which cause prolonged hospitalisation and can be fatal, with repercussions also in terms of health economics. C. difficile is the most common cause of antibiotic-associated diarrhoea in the healthcare setting. The problem of bacterial forms that are increasingly resistant to common antibiotic treatments is also reflected in C. difficile infection (CDI). One of the causes of CDI is intestinal dysmicrobialism induced by prolonged antibiotic therapy. Moreover, in recent years, the emergence of increasingly virulent strains resistant to antibiotic treatment has made the picture even more complex. Evidence on preventive treatments to avoid recurrence is unclear. Current guidelines indicate the following antibiotics for the treatment of CDI: metronidazole, vancomycin, and fidaxomycin. This short narrative review provides an overview of CDI, antibiotic resistance, and emerging treatments.

It's All in the Interaction: Early Acquired Words Are Both Frequent and Highly Imageable.

Prior studies have found that children are more likely to learn words that are frequent in the input and highly imageable. Many theories of word learning, however, predict that these variables should interact, particularly early in development: frequency of a form is of little use if you cannot infer its meaning, and a concrete word cannot be acquired if you never hear it. The present study explores this interaction, how it changes over time and its relationship to syntactic category effects in children acquiring American English. We analyzed 1461 monolingual English-speaking children aged 1;4-2;6 from the MB-CDI norming study (Fenson et al., 1994). Word frequency was estimated from the CHILDES database, and imageability was measured using adult ratings. There was a strong over-additive interaction between frequency and imageability, such that children were more likely to learn a word if it was both highly imageable and very frequent. This interaction was larger in younger children than in older children. There were reliable differences between syntactic categories independent of frequency and imageability, which did not interact with age. These findings are consistent with theories in which children's early words are acquired by mapping frequent word forms onto concrete, perceptually available referents, such that highly frequent items are only acquired if they are also imageable, and vice versa.

[Cadmium Phytoremediation Effect of Sweet Sorghum Assisted with Citric Acid on Typical Parent Soil in Southern China].

Sweet sorghum has a large biomass and strong cadmium (Cd) absorption capacity, which has the potential for phytoremediation of Cd-contaminated soil. In order to study the Cd phytoremediation effect of sweet sorghum assisted with citric acid on the typical parent materials in southern China, a field experiment was carried out in two typical parent material farmland areas (neutral purple mud field and jute sand mud field) with Cd pollution in Hunan Province. The results showed that:① Citric acid had no inhibitory effect on the growth of sweet sorghum. After the application of citric acid, the aboveground biomass of sweet sorghum at the maturity stage increased by 10.1%-24.7%. ② Both sweet sorghum planting and citric acid application reduced the soil pH value, and the application of citric acid further reduced the soil pH value at each growth stage of sweet sorghum; this decrease was greater in the neutral purple mud field, which decreased by 0.24-0.72 units. ③ Both sweet sorghum planting and citric acid application reduced the total amount of soil Cd, and the decreases in the neutral purple mud field and jute sand mud field were 23.8%-52.2% and 17.1%-31.8%, respectively. The acid-extractable percentage of soil Cd in both places increased by 38.6%-147.7% and 4.8%-22.7%, respectively. ④ The application of citric acid could significantly increase the Cd content in various tissues of sweet sorghum. The Cd content in the aboveground part of the plant in the neutral purple mud field was higher than that in the jute sand mud field, and the Cd content in stems and leaves was 0.25-1.90 mg·kg-1 and 0.21-0.64 mg·kg-1, respectively. ⑤ After applying citric acid, the Cd extraction amount of sweet sorghum in neutral purple mud soil in the mature stage reached 47.56 g·hm-2. In summary, citric acid could enhance the efficiency of sweet sorghum in the phytoremediation of Cd-contaminated soil, and the effect was better in neutral purple mud fields. This technology has the potential for remediation coupled with agro-production for heavy metal-contaminated farmland.

[Effects of Modified Distillers' Grains Biochar on Cadmium Forms in Purple Soil and Cadmium Uptake by Rice].

Biochar and modified biochar have been widely used as remediation materials in heavy metal-contaminated agricultural soils. In order to explore economical and effective materials for the remediation of cadmium (Cd)-contaminated acidic purple soil, distillers 'grains were converted into distillers' grains biochar (DGBC) and modified using nano-titanium dioxide (Nano-TiO2) to produce two types of modified DGBCs:TiO2/DGBC and Fe-TiO2/DGBC. A rice pot experiment was used to investigate the effects of different biochar types and application rates (1%, 3%, and 5%) on soil properties, nutrient content, Cd bioavailability, Cd forms, rice growth, and Cd accumulation. The results showed that:① DGBC application significantly increased soil pH, cation exchange capacity (CEC), and nutrient content, with TiO2/DGBC and Fe-TiO2/DGBC exhibiting better effects. ② DGBC and modified DGBCs transformed Cd from soluble to insoluble forms, increasing residual Cd by 1.22% to 18.46% compared to that in the control. Cd bioavailability in soil decreased significantly, with available cadmium being reduced by 11.81% to 23.67% for DGBC, 7.64% to 43.85% for TiO2/DGBC, and 19.75% to 55.82% for Fe-TiO2/DGBC. ③ DGBC and modified DGBCs increased rice grain yield, with the highest yields observed at a 3% application rate:30.60 g·pot-1 for DGBC, 37.85 g·pot-1 for TiO2/DGBC, and 39.10 g·pot-1 for Fe-TiO2/DGBC, representing 1.13, 1.40, and 1.44 times the control yield, respectively. Cd content in rice was significantly reduced, with grain Cd content ranging from 0.24 to 0.30 mg·kg-1 for DGBC, 0.16 to 0.26 mg·kg-1 for TiO2/DGBC, and 0.14 to 0.24 mg·kg-1 for Fe-TiO2/DGBC. Notably, Cd content in rice grains fell below the food safety limit of 0.2 mg·kg-1 (GB2762-2022) at 5% for TiO2/DGBC and 3% and 5% for Fe-TiO2/DGBC. In conclusion, Nano-TiO2 modified DGBC effectively reduced the bioavailability of soil Cd through its own adsorption and influence on soil Cd forms distribution, thus reducing the absorption of Cd by rice and simultaneously promoting rice growth and improving rice yield. It is a type of Cd-contaminated soil remediation material with a potential application prospect. The results can provide scientific basis for farmland restoration and agricultural safety production of Cd-contaminated acidic purple soil.

Enhanced Uranium Extraction via Charge Dynamics and Interfacial Polarization in MoS2/GO Heterojunction Electrodes.

The removal of uranyl ions (UO2 2+) from water is challenging due to their chemical stability, low concentrations, complex water matrix, and technical limitations in extraction and separation. Herein, a novel molybdenum disulfide/graphene oxide heterojunction (MoS2/GO-H) is developed, serving as an effective electrode for capacitive deionization (CDI). By combining the inherent advantages of electroadsorption and electrocatalysis, an innovative electroadsorption-electrocatalysis system (EES) strategy is introduced. This system utilizes interface polarization at the MoS2 and GO interface, creating an additional electric field that significantly influences carrier behavior. The MoS2/GO-H electrode, with its extraordinary adsorption capacity of 805.57 mg g-1 under optimal conditions, effectively treated uranium-laden wastewater from a mine, achieving over 90% removal efficiency despite the presence of numerous competing ions at concentrations significantly higher than UO2 2+. Employing density functional theory (DFT) and ab initio molecular dynamics (AIMD) simulations, it is found that the MoS2/GO-H total charge density at the Fermi level, enhanced by interfacial polarization, surpasses that of separate MoS2 and GO, markedly boosting conductivity and electrocatalytic effectiveness.