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The efficient detection of n-butanol, which is in demand for highly sensitive materials, is essential for multiple applications. A nonaqueous method was applied to prepare NiFe2O4 nanoparticles (NPs) using benzyl alcohol as a solvent, which shows a size of 7.9 ± 1.6 nm and a large surface area of 82.23 m2/g. To further improve the sensing performance for n-butanol, Pd/PdO functionalization was sensitized with NiFe2O4 NPs. Gas sensing results demonstrate that the Pd/PdO-NiFe2O4 exhibits an enhanced response of 36.9 to 300 ppm n-butanol and a fast response and recovery time (18.2/17.6 s) at 260 °C. Furthermore, the Pd/PdO-NiFe2O4-based sensor possesses a good linear relationship between responses and the n-butanol concentration from 1 to 1000 ppm, and great selectivity against other volatile organic compounds (VOCs). The excellent sensing enhancement is attributed to the catalytic effects of Pd/PdO, the increase of oxygen vacancies, and the formation of heterojunction between PdO and NiFe2O4. Thus, this study offers an effective route for the synthesis of Pd/PdO-functionalized NiFe2O4 NPs to achieve n-butanol detection with excellent sensing performance.
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The development of cost-effective and eco-friendly fertilizers is crucial for enhancing iron (Fe) uptake in crops and can help alleviate dietary Fe deficiencies, especially in populations with limited access to meat. This study focused on the application of MgFe-layered double hydroxide nanoparticles (MgFe-LDHs) as a potential solution. We successfully synthesized and characterized MgFe-LDHs and observed that 1-10 mg/L MgFe-LDHs improved cucumber seed germination and water uptake. Notably, the application of 10 mg/L MgFe-LDHs to roots significantly increased the seedling emergence rate and growth under low-temperature stress. The application of 10 mg/L MgFe-LDHs during sowing increased the root length, lateral root number, root fresh weight, aboveground fresh weight, and hypocotyl length under low-temperature stress. A comprehensive analysis integrating plant physiology, nutrition, and transcriptomics suggested that MgFe-LDHs improve cold tolerance by upregulating SA to stimulate CsFAD3 expression, elevating GA3 levels for enhanced nitrogen metabolism and protein synthesis, and reducing levels of ABA and JA to support seedling emergence rate and growth, along with increasing the expression and activity of peroxidase genes. SEM and FTIR further confirmed the adsorption of MgFe-LDHs onto the root hairs in the mature zone of the root apex. Remarkably, MgFe-LDHs application led to a 46% increase (p < 0.05) in the Fe content within cucumber seedlings, a phenomenon not observed with comparable iron salt solutions, suggesting that the nanocrystalline nature of MgFe-LDHs enhances their absorption efficiency in plants. Additionally, MgFe-LDHs significantly increased the nitrogen (N) content of the seedlings by 12% (p < 0.05), promoting nitrogen fixation in the cucumber seedlings. These results pave the way for the development and use of LDH-based Fe fertilizers.
Subject(s)
Cold Temperature , Cucumis sativus , Iron , Seedlings , Cucumis sativus/growth & development , Cucumis sativus/metabolism , Cucumis sativus/drug effects , Seedlings/growth & development , Seedlings/metabolism , Seedlings/drug effects , Iron/metabolism , Plant Roots/metabolism , Plant Roots/growth & development , Germination/drug effects , Hydroxides/pharmacology , Hydroxides/metabolism , Fertilizers , Gene Expression Regulation, Plant/drug effects , Nanoparticles/chemistry , Stress, Physiological , Magnesium/metabolismABSTRACT
PURPOSE: Posterior circulation ischemic stroke (PCIS) possesses unique features. However, previous studies have primarily or exclusively relied on anterior circulation stroke cases to build machine learning (ML) models for predicting onset time. To date, there is no research reporting the effectiveness and stability of ML in identifying PCIS onset time. We aimed to build diffusion-weighted imaging-based ML models to identify the onset time of PCIS patients. METHODS: Consecutive PCIS patients within 24 h of definite symptom onset were included (112 in the training set and 49 in the independent test set). Images were processed as follows: volume of interest segmentation, image feature extraction, and feature selection. Five ML models, naïve Bayes, logistic regression, tree ensemble, k-nearest neighbor, and random forest, were built based on the training set to estimate the stroke onset time (binary classification: ≤ 4.5 h or > 4.5 h). Relative standard deviations (RSD), receiver operating characteristic (ROC) curves, and the calibration plot was performed to evaluate the stability and performance of the five models. RESULTS: The random forest model had the best performance in the test set, with the highest area under the curve (AUC, 0.840; 95% CI: 0.706, 0.974). This model also achieved the highest accuracy, sensitivity, specificity, positive predictive value, and negative predictive value (83.7%, 64.3%, 91.4%, 75.0%, and 86.5%, respectively). Furthermore, the model had high stability (RSD = 0.0094). CONCLUSION: The PCIS case-based ML model was effective for estimating the symptom onset time and achieved considerably high specificity and stability.
Subject(s)
Ischemic Stroke , Machine Learning , Humans , Ischemic Stroke/diagnostic imaging , Female , Male , Aged , Middle Aged , Diffusion Magnetic Resonance Imaging/methods , Time Factors , Image Interpretation, Computer-Assisted/methods , Bayes Theorem , RadiomicsABSTRACT
Envafolimab, a PD-L1 inhibitor, has demonstrated potential in treating advanced malignant solid tumors (AMST). To study its' efficacy and safety in AMST, our retrospective study recruited 64 patients with various AMST, and treated with Envafolimab (400 mg every 3 weeks). We divided the patients into two cohorts: Cohort 1 (25 patients) receiving Envafolimab as first-line therapy, and Cohort 2 (39 patients) receiving it as second-line or subsequent therapy. Our analysis focused on Envafolimab's efficacy and safety. Over a median follow-up of 7.1 months, Cohort I reported a Disease Control Rate (DCR) of 72.0% and an Objective response rate (ORR) of 12.0%, while Cohort II had a DCR of 51.3% and an ORR of 5.1%. Notably, patients with more than four treatment cycles showed higher DCR and longer Progression-Free Survival (PFS) than those with fewer cycles. Adverse events were observed in 68.8% of patients, with severe events (CTCAE grade 3/4) in 14.1%. Most adverse events were mild, leading to treatment discontinuation in only 3.1% of patients, with no life-threatening events reported. In summary, Envafolimab is a safe and effective treatment for AMST, in both initial and later therapy stages, particularly with extended treatment duration, meriting further clinical trials.
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Layered double hydroxides (LDHs) have been widely used in the field of plant engineering, such as DNA/RNA transformation and enhancing plant disease resistance. However, few studies have examined the direct effects of LDHs on plants and their potential utility as nanofertilizers. In this study, the retention capacity of Cu/Fe-layered double hydroxide nanoparticles (CuFe-LDHs) was assessed by comparative experiments on vegetables. The results showed that the retention of CuFe-LDHs in leafy vegetables was high, such as lettuce. Phenotypic analysis revealed that the fresh and dry weights of lettuce leaves were both increased by spraying 10-100 µg/mL CuFe-LDHs. Using the optimal concentration of 10 µg/mL, we conducted further experiments to elucidate the mechanism of CuFe-LDHs promoting lettuce growth. It was found that the application of CuFe-LDHs had a significant effect on growth and induced physiological, transcriptomic, and metabolomic changes, including an increase in the chlorophyll b content, net photosynthetic rate, and intercellular carbon dioxide concentration, as well as modifications in gene expression patterns and metabolite profiles. This work provides compelling evidence that CuFe-LDHs can efficiently adsorb on the surface of lettuce leaves through hydrogen bonding, promote lettuce growth, mitigate the toxicity of heavy metal ions compared to their raw materials at the same concentration and offer a molecular-scale insight into the response of leafy vegetables to CuFe-LDHs.
Subject(s)
Metals, Heavy , Nanoparticles , Lactuca , HydroxidesABSTRACT
Objective: To explore the altered expression of estrogen receptor (ER), progesterone receptor (PR), human epidermal growth factor receptor 2 (HER2), and cell proliferation index (Ki-67) in primary and metastatic breast cancer lesions and the correlation between the primary tumor size, lymph node metastasis, Tumor Node Metastasis (TNM) stage, molecular typing, and disease-free survival (DFS) and their clinical significance. Methods: A retrospective analysis was conducted on the clinical data of 130 patients with metastatic breast cancer biopsy admitted to the Cancer Center of the Second Affiliated Hospital of Anhui Medical University in Hefei, China, from 2014-2019. The altered expression of ER, PR, HER2, and Ki-67 in primary and metastatic lesions of breast cancer was analyzed with respect to the site of metastasis, size of the primary tumor, lymph node metastasis, disease progression, and prognosis. Results: The inconsistent expression rates of ER, PR, HER2, and Ki-67 in primary and metastatic lesions were 47.69%, 51.54%, 28.10%, and 29.23%, respectively. The size of the primary lesion was not, but that accompanied by lymph node metastasis was related to the altered receptor expression. Patients with positive ER and PR expression in both primary and metastatic lesions had the longest DFS, while those with negative expression had the shortest DFS. Also, changes in HER2 expression in primary and metastatic lesions were not associated with DFS. Patients with low expression of Ki-67 in both primary and metastatic lesions had the longest DFS, while patients with high expression had the shortest DFS. Conclusion: Heterogeneity was detected in the expression levels of ER, PR, HER2, and Ki-67 in the primary and metastatic breast cancer lesions, which has a guiding significance for the treatment and prognosis of patients.
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BACKGROUND: The Mg-Al-lactate layered double hydroxide nanosheet (LDH-NS) has shown great potential as an optimal nanocarrier for extensive use in plants. However, previous studies in plant sciences have not provided a clear description of the application for the LDH-NSs-based double-stranded RNA (dsRNA) delivery (LDH-dsRNA) system in different tissues of both model and non-model species. RESULTS: LDH-NSs were synthesized by using the co-precipitation method, while the dsRNAs targeting genes of interest were prepared in vitro using T7 RNA polymerase. The LDH-dsRNA bioconjugates with a neutral charge were produced by incubating with the mass ratio of LDH-NSs to dsRNA at 3:1, which were then introduced into intact plant cells using three different approaches, including injection, spray, and soak. The LDH-dsRNA delivery method was optimized by inhibiting the expression of the Arabidopsis thaliana ACTIN2 gene. As a result, soaking A. thaliana seedlings in a medium containing LDH-dsRNA for 30 min led to the silencing of 80% of the target genes. The stability and effectiveness of the LDH-dsRNA system were further confirmed by the high-efficiency knockdown of plant tissue-specific genes, including that encoding phytoene desaturase (PDS), WUSCHEL (WUS), WUSCHEL-related homeobox 5 (WOX5), and ROOT HAIR DEFECTIVE 6 (RHD6). In addition, the LDH-dsRNA system was employed in cassava, where it was found that the expression of the gene encoding nucleotide-binding site and leucine-rich repeat (NBS-LRR) was significantly reduced. As a result, the resistance of cassava leaves to pathogens was weakened. Noteworthy, the injection of LDH-dsRNA into leaves resulted in a significant downregulation of target genes in both stems and flowers, indicating the successful transport of LDH-dsRNA from leaves to other parts of plants. CONCLUSIONS: LDH-NSs have proven to be a highly effective molecular tool for delivering dsRNA into intact plant cells, enabling accurate control of target gene expression.
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CCHamide-2 (CCHa2) is a protostome excitatory peptide ortholog known for various arthropod species. In fruit flies, CCHa2 plays a crucial role in the endocrine system, allowing peripheral tissue to communicate with the central nervous system to ensure proper development and the maintenance of energy homeostasis. Since the formation of odor-sugar associative long-term memory (LTM) depends on the nutrient status in an animal, CCHa2 may play an essential role in linking memory and metabolic systems. Here we show that CCHa2 signals are important for consolidating appetitive memory by acting on the rewarding dopamine neurons. Genetic disruption of CCHa2 using mutant strains abolished appetitive LTM but not short-term memory (STM). A post-learning thermal suppression of CCHa2 expressing cells impaired LTM. In contrast, a post-learning thermal activation of CCHa2 cells stabilized STM induced by non-nutritious sugar into LTM. The receptor of CCHa2, CCHa2-R, was expressed in a subset of dopamine neurons that mediate reward for LTM. In accordance, the receptor expression in these dopamine neurons was required for LTM specifically. We thus concluded that CCHa2 conveys a sugar nutrient signal to the dopamine neurons for memory consolidation. Our finding establishes a direct interplay between brain reward and the putative endocrine system for long-term energy homeostasis.
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Background: The timely addition of anlotinib to the nab-paclitaxel/gemcitabine regimen may further increase the treatment efficacy for pancreatic adenocarcinoma (PDAC), which has not yet been reported. Therefore, we aimed to compare the efficacy and safety of anlotinib plus nab-paclitaxel/gemcitabine in the first-line treatment of patients with unresectable or metastatic PDAC. Methods: This was a retrospective cohort of patients with unresectable or metastatic PDAC performed in The First Affiliated Hospital of Anhui Medical University from August 17, 2019 to April 3, 2021. Patients who received anlotinib plus nab-paclitaxel/gemcitabine treatment were defined as the anlotinib plus chemotherapy group and patients who received nab-paclitaxel/gemcitabine were defined as the chemotherapy group. The primary outcomes were progression-free survival (PFS) and overall survival (OS). Secondary outcomes were the objective response rate (ORR), the disease control rate (DCR), and toxic side effects. Clinical data and follow-up information were mainly obtained from hospital records or by telephone. Results: A total of 33 patients were included in this study, with 17 cases in the anlotinib plus chemotherapy group and 16 cases in the chemotherapy group. The median PFS (mPFS) of the anlotinib plus chemotherapy group was 5 months while the mPFS of the chemotherapy group was 2.7 months (P=0.0220). The median OS (mOS) of the anlotinib plus chemotherapy group was 9 months while the mOS of the chemotherapy group was 6 months (P=0.0060). The 3-month and 6-month PFS, and the 6- and 12-month OS of the anlotinib plus chemotherapy group were significantly higher than those of the chemotherapy group (P<0.05). The proportion of patients with hematological toxicities in the anlotinib plus chemotherapy group was not significantly higher than that in the chemotherapy group. Conclusions: Anlotinib plus nab-paclitaxel/gemcitabine as a first-line treatment regimen is safe and may prolong survival compared with nab-paclitaxel/gemcitabine chemotherapy in patients with unresectable or metastatic PDAC. Randomized controlled trials with large sample sizes are warranted to further evaluate the treatment effects of anlotinib in PDAC. Keywords: Pancreatic adenocarcinoma (PDAC); anlotinib; nab-paclitaxel/gemcitabine; progression-free survival (PFS); overall survival (OS).
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Background: Sintilimab is a recombinant fully human anti-programmed death 1 (PD-1) monoclonal antibody that blocks the interaction of PD-1 with its ligand. We evaluated the safety and efficacy of sintilimab combined with chemotherapy and targeted therapy in the treatment of advanced malignant tumors. Methods: We performed a retrospective analysis of the clinical data of patients with advanced malignant tumors treated with sintilimab combined with chemotherapy and targeted therapy admitted to the Third Ward of the Department of Medical Oncology, First Affiliated Hospital of Anhui Medical University, China, from July 2019 to February 2021. The objective response rate (ORR), disease control rate (DCR), progression-free survival (PFS), overall survival (OS) and related adverse reactions were analyzed. Results: A total of 48 patients with advanced malignant tumors treated with sintilimab combined with chemotherapy and targeted therapy. All 48 patients completed 2 courses of treatment, and the ORR and DCR were 20.83% and 81.25%. The median PFS for all patients in this study was 7 months, and the median OS was not yet reached. The median PFS for the first-line and second-line patients was 10 months, and the median OS was not yet reached. The median PFS for third-line and beyond patients was 7 months, and the median OS was 10 months. The differences in PFS and OS were both statistically significant. Adverse events occurred in 24 patients, of which 18 patients had grade I-II adverse events and 6 patients had grade III-IV adverse events. Conclusions: Sintilimab is an inexpensive PD-1 drug produced in China. Sintilimab combination therapy showed good safety in the treatment of advanced malignant tumors, with increases in the treatment efficacy and DCR for advanced tumors. Because of few adverse reactions and proven efficacy, sintilimab combination therapy can be used as an option for the treatment of advanced malignant tumors.
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BACKGROUND: Layered double hydroxide lactate nanosheets (LDH-lactate-NS) are powerful carriers for delivering macro-molecules into intact plant cells. In the past few years, some studies have been carried out on DNA/RNA transformation and plant disease resistance, but little attention has been paid to these factors during LDH-lactate-NS synthesis and delamination, nor has their relationship to the DNA adsorption capacity or transformation efficiency of plant cells been considered. RESULTS: Since the temperature during delamination alters particle sizes and zeta potentials of LDH-lactate-NS products, we compared the LDH-lactate-NS stability, DNA adsorption rate and delivery efficiency of fluorescein isothiocyanate isomer I (FITC) of them, found that the LDH-lactate-NS obtained at 25 °C has the best characters for delivering biomolecules into plant cell. To understand the potential side effects and cytotoxicity of LDH-lactate-NS to plants, we compared the root growth rate between the Arabidopsis thaliana seedlings grown in the culture medium with 1-300 µg/mL LDH-lactate-NS and equivalent raw material, Mg(lactate)2 and Al (lactate)3. Phenotypic analysis showed LDH in a range of 1-300 µg/mL can enhance the root elongation, whereas the same concentration of raw materials dramatically inhibited root elongation, suggesting the nanocrystallization has a dramatical de-toxic effect to Mg(lactate)2 and Al (lactate)3. Since enhancing of root elongation by LDH is an unexpected phenomenon, we further designed experiments to investigate influence of LDH to Arabidopsis seedlings. We further used the gravitropic bending test, qRT-PCR analysis of auxin transport proteins, non-invasive micro-test technology and liquid chromatography-mass spectrometry to investigate the auxin transport and distribution in Arabidopsis root. Results indicated that LDH-lactate-NS affect root growth by increasing the polar auxin transport. CONCLUSIONS: Optimal synthesized LDH-lactate-NS can delivery biomolecules into intact plant cells with high efficiency and low cytotoxity. The working solution of LDH-lactate-NS can promote root elongation via increase the polar auxin transport in Arabidopsis roots.
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Understanding the changing patterns of vascular cambium during seasonal cycles is crucial to reveal the mechanisms that control cambium activity and wood formation, but this area has been underexplored, especially in conifers. Here, we quantified the changing cellular morphology patterns of cambial zones during the active, transition and dormant stages. With the help of toluidine blue and periodic acid-Schiff staining to visualize cell walls and identify their constituents, we observed decreasing cambial cell layers, thickening of newly formed xylem cell walls and increased polysaccharide granules in phloem from June to the following March over the course of our collecting period. Pectin immunofluorescence showed that dormant-stage cambium can produce highly abundant de-esterified homogalacturonan and (1-4)-ß-d-galactan epitopes, whereas active cambium can strong accumulate high methylesterified homogalacturonan. Calcofluor white staining and confocal Raman spectroscopy analysis revealed regular changes in the chemical composition of cell walls, such as relative lower cellulose deposition in transition stage in vascular cambium, and higher lignin accumulation was found in dormant stage in secondary xylem. Moreover, real-time quantitative polymerase chain reaction analysis suggested that various IAA (Aux/IAA protein), CesA, CslA and HDZ genes, as well as NAC, PME3 and PME4, may be involved in cambium activities and secondary xylem formation. Taken together, these findings provide new information about cambium activity and cell differentiation in the formation, structure and chemistry in conifers during the active-dormant transition.
Subject(s)
Cambium , Pinus , Phloem/metabolism , Seasons , Xylem/geneticsABSTRACT
Circular RNA (circRNA) is a novel class of endogenous long non-coding RNA (lncRNA) and participates in diverse physiological process in plants. From the dataset obtained by high-throughput RNA sequencing, we identified a circRNA encoded by the sense strand of the exon regions spanning two RuBisCO small subunit genes, RBCS2B and RBCS3B, in Arabidopsis thaliana. We further applied the single specific primer-polymerase chain reaction (PCR) and Sanger sequencing techniques to verify this circRNA and named it ag-circRBCS (antisense and across genic-circular RNA RBCS). Using quantitative real-time PCR (qRT-PCR), we found that ag-circRBCS shares a similar rhythmic expression pattern with other RBCS genes. The expression level of ag-circRBCS is 10-40 times lower than the expression levels of RBCS genes in the photosynthetic organs in Arabidopsis, whereas the Arabidopsis root lacked ag-circRBCS expression. Furthermore, we used the delaminated layered double hydroxide lactate nanosheets (LDH-lactate-NS) to deliver in vitro synthesized ag-circRBCS into Arabidopsis seedlings. Our results indicate that ag-circRBCS could significantly depress the expression of RBCS. Given that ag-circRBCS was expressed at low concentration in vivo, we suggest that ag-circRBCS may represent a fine-tuning mechanism to regulating the expression of RBCS genes and protein content in Arabidopsis.
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Regulation of reward signaling in the brain is critical for appropriate judgement of the environment and self. In Drosophila, the protocerebral anterior medial (PAM) cluster dopamine neurons mediate reward signals. Here, we show that localized inhibitory input to the presynaptic terminals of the PAM neurons titrates olfactory reward memory and controls memory specificity. The inhibitory regulation was mediated by metabotropic gamma-aminobutyric acid (GABA) receptors clustered in presynaptic microdomain of the PAM boutons. Cell type-specific silencing the GABA receptors enhanced memory by augmenting internal reward signals. Strikingly, the disruption of GABA signaling reduced memory specificity to the rewarded odor by changing local odor representations in the presynaptic terminals of the PAM neurons. The inhibitory microcircuit of the dopamine neurons is thus crucial for both reward values and memory specificity. Maladaptive presynaptic regulation causes optimistic cognitive bias.
Subject(s)
Behavior, Animal , Brain/metabolism , Dopaminergic Neurons/metabolism , Drosophila melanogaster/metabolism , GABAergic Neurons/metabolism , Neural Inhibition , Presynaptic Terminals/metabolism , Reward , Animals , Animals, Genetically Modified , Cognition , Dopamine/metabolism , Drosophila Proteins/genetics , Drosophila Proteins/metabolism , Drosophila melanogaster/genetics , Memory , Olfactory Perception , Receptors, GABA-B/genetics , Receptors, GABA-B/metabolism , Receptors, Metabotropic Glutamate/genetics , Receptors, Metabotropic Glutamate/metabolism , Smell , gamma-Aminobutyric Acid/metabolismABSTRACT
The mushroom body (MB) of Drosophila melanogaster has multiple functions in controlling memory and behavior.1-9 However, circuit mechanisms that generate this functional diversity are largely unclear. Here, we systematically probed the behavioral contribution of each type of MB output neuron (MBON) by blocking during acquisition, retention, or retrieval of reward or punishment memories. We evaluated the contribution using two conditioned responses: memory-guided odor choice and odor source attraction. Quantitative analysis revealed that these conditioned odor responses are controlled by different sets of MBONs. We found that the valence of memory, rather than the transition of memory steps, has a larger impact on the patterns of required MBONs. Moreover, we found that the glutamatergic MBONs forming recurrent circuits commonly contribute to appetitive memory acquisition, suggesting a pivotal role of this circuit motif for reward processing. Our results provide principles how the MB output circuit processes associative memories of different valence and controls distinct memory-guided behaviors.
Subject(s)
Drosophila melanogaster , Memory , Mushroom Bodies , Animals , Conditioning, Classical , Drosophila melanogaster/physiology , Mushroom Bodies/physiology , OdorantsABSTRACT
Hazardous metal pollution became a severe environmental issue in China. An efficient precipitation-flotation process was developed to achieve fast removal for metal-ions from wastewater. Structure and strength of precipitate particles/flocs significantly influence the flotation removal of metal-ions. Formation and growth-evolution of precipitate flocs in precipitate flotation were studied by stage analysis of precipitate particles-formation, flocs-regulation and flotation separation. The results demonstrate that early formed precipitates MHA(humics-metal complexing particles) have small particle size, high fractal dimension, low strength and recovery factor. The addition of Fe3+ and CTAB(cetyl trimethyl ammonium bromide) reagents make the precipitate particles aggregated to flocs(MHA-Fe, MHA-Fe-CTAB) much more large, loose, coarse, and small-density. The final generated MHA-Fe-CTAB flocs are hard to be broken up, easy to be recovered and efficient to be separated by flotation process. The flotation removal of MHA-Fe-CTAB flocs is clearly higher than that of MHA or MHA-Fe. The flotation results of MHA-Fe-CTAB are as follows: flotation removal of 98.7 ± 0.40%-99.9 ± 0.10%, residual TOC of 0.96 ± 0.38-1.35 ± 0.41 mg/L and turbidity of 0.44 ± 0.09-0.63 ± 0.16 NTU. Introducing Fe3+ and CTAB reagents into flotation solution contributes to the growth-evolution of precipitate flocs, which could intensify the metal-ions removal via precipitate flotation process and result in more ideal purification indexes for metal-containing wastewater.
Subject(s)
Wastewater , Water Purification , Cetrimonium , China , Indicators and Reagents , IonsABSTRACT
Electrochemical (EC) sensors have been widely developed for DNA detection, but they are seldom used in a simple, economic, and efficient manner. In this work, for the first time, EC cloth-based DNA sensors (ECDSs) are developed as a new class of EC DNA sensors, without the need for cumbersome chip fabrication and high-cost peripheral facilities. Carbon ink- and solid wax-based screen printing were used to produce ultracheap sensing devices (the cost of one sensor is estimated to be $0.045). Also, a CdTe QDs/MWCNTs nanocomposite (CdTe-MWCNTs) was applied to modify the sensing interface to obtain a stronger EC signal. Specifically, the newly developed double linear hybridization chain reaction (DL-HCR) greatly amplified the EC signal, relative to the conventional linear HCR. Under optimized conditions, target DNA (TD) samples (75-bp DNA fragments prepared via PCR amplification) were determined in a range from 20 fM to 5 nM, with a detection limit of 8.74 fM and relative standard deviations of 2.04% and 4.75% for intra- and inter-assays at 50 pM TD, respectively. Additionally, the ECDSs had an acceptable storage stability and high selectivity. Importantly, the ECDSs, coupled with simple enzyme digestion, could detect genomic DNA from Listeria monocytogenes (L. monocytogenes), and a detection limit of 0.039 ng/µL was obtained. When coupled with enzyme digestion and PCR amplification, the ECDSs could determine L. monocytogenes in milk samples, with detection limits of approximately 1.64 × 104 and 11 CFU/mL. These results demonstrate that the method offers a broad prospect for cost-effective, reliable, and highly sensitive gene-sensing applications.
Subject(s)
Biosensing Techniques , DNA/genetics , Electrochemical Techniques , Cadmium Compounds/chemistry , Quantum Dots/chemistry , Tellurium/chemistryABSTRACT
In this work, a cloth-based chemiluminescence (CL) biosensor has been firstly presented for highly sensitive determination of long PCR amplicons. Under the action of a hybridization chain reaction, a good deal of hemin/G-quadruplex DNAzyme molecules are produced, which can effectively enhance the CL signal. Moreover, effective cloth-based DNA biosensors can be fabricated by sequential wax screen-printing and surface-modification processes. Especially, the integration of a desirable hydrophobic barrier and gravity/capillary flow onto the flow channel of the cloth-based device makes the biosensor easy to be fabricated and to be associated with a flow CL. For the luminol/H2O2-based CL system, the signals are triggered by the hemin/G-quadruplex DNAzyme and are recorded by a low-cost CCD. Under optimized conditions, the determination range of target DNA is 0.002-20,000 pM and its limit of detection is calculated to be 1.1 fM. The results show that the proposed CL biosensor has a good analytical performance, such as high detectability and specificity, wide linear range, and receivable reproducibility and stability. Finally, the proposed biosensor is proven by the fact that this method can successfully detect the target DNA prepared from the Listeria monocytogenes-spiked milk samples. Therefore, it is believed to have the potential application prospects in food safety and environmental monitoring. Graphical abstract.
Subject(s)
Bacterial Toxins/genetics , Biosensing Techniques/methods , DNA, Bacterial/genetics , DNA, Catalytic/chemistry , G-Quadruplexes , Heat-Shock Proteins/genetics , Hemolysin Proteins/genetics , Listeria monocytogenes/genetics , Animals , DNA, Bacterial/analysis , Hemin/chemistry , Listeria monocytogenes/isolation & purification , Listeriosis/microbiology , Luminescent Measurements/methods , Microfluidic Analytical Techniques/methods , Milk/microbiology , Nucleic Acid Hybridization/methodsABSTRACT
The aim of this work was to analyze the expression of Ki-67 in ovary, testis of aging mice with anthocyanidin extract from Summer-black-grape. ICR mice (the aging group and the anthocyanidin-groups (50 mg/kg/D-group, 75 mg/kg/D-group and 100 mg/kg/D-group) were employed to evaluate the effect of grape anthocyanidin on reproductive system. The results showed that the anthocyanidin had strong scavenging ability for free radicals, the level of oxidation in serum of mice treated with anthocyanidin was low, and the pathological changes were not obvious. In the anthocyanidin group, the Ki-67 positive particles in the testis and ovary tissue were significantly decreased. The anthocyanidin of Summer-black-grape reduces the expression of Ki-67 protein in the testis or ovary of aging mice. In gonadal cells of aging mice, the anthocyanidin were shown protective effect in the proliferation.