DTPA Research Articles

Effect of magnetic resonance imaging in liver metastases

This letter to the editor is a commentary on a study titled "Liver metastases: The role of magnetic resonance imaging." Exploring a noninvasive imaging evaluation system for the biological behavior of hepatocellular carcinoma (HCC) is the key to achieving precise diagnosis and treatment and improving prognosis. This review summarizes the role of magnetic resonance imaging in the detection and evaluation of liver metastases, describes its main imaging features, and focuses on the added value of the latest imaging tools (such as T1 weighted in phase imaging, T1 weighted out of phase imaging; diffusion-weighted imaging, T2 weighted imaging). In this study, I investigated the necessity and benefits of gadolinium ethoxybenzyl diethylenetriamine pentaacetic acid for HCC diagnostic testing and prognostic evaluation.

Glomerular filtration rate measurement during platinum treatment for urothelial carcinoma: optimal methods for clinical practice

BackgroundWe assessed the accuracy of four estimated glomerular filtration rate (eGFR) methods: MDRD, Cockcroft–Gault, CKD-EPI, and Wright.MethodThe four methods were compared to measure GFR (mGFR) in patients with urothelial urinary tract cancer (T2-T4bNxMx) receiving platinum-based chemotherapy at Rigshospitalet, Copenhagen, from January 2019 to December 2021. Using standardized assays, creatinine values were measured, and mGFR was determined using Technetium-99 m diethylenetriaminepentaacetic acid (Tc-99 m-DTPA) or Cr-51-ethylenediaminetetraacetic acid (Cr-51-EDTA) plasma clearance. Patients (n = 146) with both mGFR and corresponding creatinine values available were included (n = 345 measurements).ResultsThe CKD-EPI method consistently demonstrated superior accuracy, with the lowest Total Deviation Index of 21.8% at baseline and 22.9% for all measurements compared to Wright (23.4% /24.1%), MDRD (26.2%/25.5%), and Cockcroft–Gault (25.x%/25.1%). Bland Altman Limits of agreement (LOA) ranged from − 32 ml/min (Cockcroft–Gault) to + 33 ml/min (MDRD), with CKD-EPI showing the narrowest LOA (− 27 ml/min to + 24 ml/min and lowest bias (0.3 ml/min). Establishing an eGFR threshold at 85 ml/min—considering both the lower limit of agreement (LOA) and the minimum cisplatin limit at 60 ml/min—allows for the safe omission of mGFR in 30% of patients in this cohort.ConclusionCKD-EPI equation emerged as the most suitable for estimating kidney function in this patient group although not meeting benchmark criteria. We recommend its use for initial assessment and ongoing monitoring, and suggest mGFR for patients with a CKD-EPI estimated GFR below 85 ml/min. This approach could reduce costs and decrease laboratory time for 30% of our UC patients.

Safety assessments of recombinant DTaP vaccines developed in South Korea.

Pertussis bacteria have many pathogenic and virulent antigens and severe adverse reactions have occurred when using inactivated whole-cell pertussis vaccines. Therefore, inactivated acellular pertussis (aP) vaccines and genetically detoxified recombinant pertussis (rP) vaccines are being developed. The aim of this study was to assess the safety profile of a novel rP vaccine under development in comparison to commercial diphtheria-tetanus-acellular pertussis (DTaP) vaccines. The two positive control DTaP vaccines (two- and tri-components aP vaccines) and two experimental recombinant DTaP (rDTaP) vaccine (two- and tri-components aP vaccines adsorbed to either aluminum hydroxide or purified oat beta-glucan) were used. Temperature histamine sensitization test (HIST), indirect Chinese hamster ovary (CHO) cell cluster assay, mouse-weight-gain (MWG) test, leukocytosis promoting (LP) test, and intramuscular inflammatory cytokine assay of the injection site performed for safety assessments. HIST results showed absence of residual pertussis toxin (PTx) in both control and experimental DTaP vaccine groups, whereas in groups immunized with tri-components vaccines, the experimental tri-components rDTaP absorbed to alum showed an ultra-small amount of 0.0066 IU/mL. CHO cell clustering was observed from 4 IU/mL in all groups. LP tests showed that neutrophils and lymphocytes were in the normal range in all groups immunized with the two components vaccine. However, in the tri-components control DTaP vaccine group, as well as two- and tri-components rDTaP with beta-glucan group, a higher monocyte count was observed 3 days after vaccination, although less than 2 times the normal range. In the MWG test, both groups showed changes less than 20% in body temperature and body weight before the after the final immunizations. Inflammatory cytokines within the muscle at the injection site on day 3 after intramuscular injection revealed no significant response in all groups. There were no findings associated with residual PTx, and no significant differences in both local and systemic adverse reactions in the novel rDTaP vaccine compared to existing available DTaP vaccines. The results suggest that the novel rDTaP vaccine is safe.

SOIL FERTILITY STATUS AS INFLUENCED BY CROPPING SYSTEM IN EASTERN DRY ZONE OF KOLAR DISTRICT IN KARNATAKA

The current investigation was carried out to determine how farming systems under rainfed and irrigated conditions affected the soil’s fertility. Thimmasandra of Bangarpet Taluka, Yadahalli of Kolar Taluka, Gaddur of Mulbagal Taluka, Thippasandra of Malur Taluka, and Kadudevandahalli of Srinivaspurua Taluka were the four villages from where the soil samples (0–15 cm) were gather. As a consequence of chemical examination, the samples’ pH and electrical conductivity were found to be between 5.8 and 7.5 and below 0.4 and 08 dS/m, respectively. The percentage of soil organic carbon in soil samples from irrigated systems was higher than that of rainfed systems, where no soil sample fell into this group. In a similar vein, soils from tomato other vegetable-based cropping systems (irrigated) have lower accessible N, P, K, and Diethylene Triamine Penta Acetic acid extractable Zn, Cu, Mn, and Fe than soils from finger millet-fallow systems (rainfed).

Preparation and Surface Modification of Nanocellulose and Its Adsorption Performance on Cu2+

Nanocellulose fibers (NCFs) were converted to cellulose nanocrystals (CNCs) and then modified with diethylenetriamine pentaacetic acid (DTPA) to form modified CNCs (DTPA–CNCs), which were investigated as adsorbents for removing Cu2+ from aqueous solution. The adsorption behavior was affected by pH, contact time, dosage and raw Cu2+ concentration. Langmuir model is the best method to fit the adsorption isotherm of experimental results. The optimal conditions for Cu2+ adsorption were 2 h at 35 °C and pH 3, the optimal adsorption capacity is 94.5 mg/g. These functional groups on the DTPA–CNCs provided enhanced adsorption capacity, compared with unmodified NCFs.

Retraction Notice: “Design and Docking Studies of [Diethylenetriaminepentaacetic Acid–(Amino Acid)2] with Acetylcholine Receptor as a Molecular Imaging Agent for Single-Photon Emission Computed Tomographic Application”

Retraction Notice: “Design and Docking Studies of [Diethylenetriaminepentaacetic Acid–(Amino Acid)2] with Acetylcholine Receptor as a Molecular Imaging Agent for Single-Photon Emission Computed Tomographic Application”

A prototype of ultrasensitive time-resolved fluoroimmunoassay for the quantitation of lead in plasma using a fluorescence-enhanced europium chelate label for the detection system.

This study describes the prototype of a novel ultra-sensitive time-resolved fluoroimmunoassay (TRFIA) for the quantification of lead (Pb) in plasma. The assay procedures were conducted in 96-microwell plates and involved the competitive binding format. The assay used a mouse monoclonal antibody, designated as 2C33, that specifically recognized the diethylenetriamine pentaacetic acid chelate of Pb (Pb-DTPA) but did not recognize Pb-free DTPA chelator. The antigen used for coating onto the inner surfaces of assay plate microwells was Pb-DTPA conjugated with bovine serum albumin protein (Pb-DTPA-BSA). The competitive binding reaction occurred between Pb-DTPA chelates, formed in the sample solutions by treating the samples with an excess DTPA, and the coated Pb-DTPA-BSA for a limited quantity of 2C33 antibody binding sites. The antigen-antibody complex formed in the plate wells was quantified by a europium-DTPA-labeled secondary antibody and a fluorescence enhancement solution. The conditions of the assay were refined, and its optimum procedures were established. The TRFIA was validated following the immunoassay validation guidelines, and all of the validation criteria were acceptable. The working range of the assay was 20-300 pg mL-1 and its limit of quantitation was 20 pg mL-1. Metals that are commonly encountered in blood plasma did not interfere with Pb in the analysis by the proposed TRFIA. The assay was applied to the quantitation of Pb in plasma samples with satisfactory accuracy and precision. The results were compared favorably with those obtained by atomic emission spectroscopy. In conclusion, the present study represents the first TRFIA for the quantitation of Pb in plasma. The assay is superior to the existing atomic spectrometric methods and other immunoassays for Pb in terms of sensitivity, convenience, and analysis throughputs. The proposed TRFIA is anticipated to effectively contribute to assessing Pb concentrations and controlling the exposure of humans to its potential toxicity.

Lobe-Based Hepatic Uptake Index of Gd-EOB-DTPA on Contrast-Enhanced MRI to Quantitatively Discriminate between Compensated and Decompensated Hepatitis B-Related Cirrhosis.

To use hepatic uptake index (HUI) of liver lobes on gadolinium ethoxybenzyl diethylenetriamine pentaacetic acid (Gd-EOB-DTPA)-enhanced magnetic resonance imaging (MRI) to discriminate between patients with hepatitis B-related cirrhosis in compensated and decompensated statuses. Forty-four consecutive patients with hepatitis B-related cirrhosis who underwent Gd-EOB-DTPA-enhanced MRI were divided into compensated and decompensated statuses based on clinical evaluation. Volume and signal intensity of individual lobes were retrospectively measured to calculate HUI of the right liver lobe (RHUI), medial (MHUI) and lateral (LHUI) left liver lobes, and caudate lobe (CHUI). Spearman's rank correlation analyses were performed to evaluate relationships of lobe-based HUI with Child-Pugh and model for end-stage liver disease (MELD) scoring system scores in compensated and decompensated statuses. The Mann-Whitney U-test was used to compare the lobe-based HUI between compensated and decompensated statuses. The performance of lobe-based HUI in distinguishing cirrhosis was evaluated using receiver operating characteristic (ROC) analysis, and the area under the ROC curve (AUC) was calculated as a measure of accuracy. Delong's method was used for statistical analysis to elucidate which HUI is optimal. Compensated and decompensated liver cirrhosis were confirmed in 25 (56.82%) and 19 (43.18%) patients, respectively. According to Spearman's rank correlation analysis, RHUI, MHUI, LHUI, and CHUI were all significantly associated with Child-Pugh and MELD scores (all P values <0.05). Receiver operating characteristic analysis demonstrated that among all lobe-based HUI parameters, RHUI could best perform the previous discrimination with a cut-off of 485.73 and obtain an AUC of 0.867. The AUC of RHUI improved and was significantly different from that of MHUI, LHUI, and CHUI (P = 0.03, P = 0.007, and P < 0.001, respectively, Delong's test). The RHUI could help quantitatively discriminate hepatitis B-related cirrhosis between compensated and decompensated statuses.

A supramolecular magnetic and multifunctional Titriplex V-grafted chitosan organocatalyst for the synthesis of acridine-1,8-diones and 2-amino-3-cyano-4H-pyran derivatives.

In this research, a new supramolecular magnetic modified chitosan, namely, Fe3O4@CS-TDI-Titriplex V, was designed and prepared conveniently by grafting diethylenetriaminepentaacetic acid (Titriplex V) onto a biopolymeric chitosan backbone having urethane, urea, ester and amide functional groups. The obtained magnetic biopolymeric nanomaterial was properly characterized by different spectroscopic, microscopic or analytical methods including FTIR spectroscopy, EDX spectroscopy, XRD, FESEM, TG-DTA and VSM. The application of the supramolecular Fe3O4@CS-TDI-Titriplex V nanocomposite as a heterogeneous solid acidic organocatalyst was investigated to promote the three-component synthesis of both acridinediones and 2-amino-3-cyano-4H-pyran derivatives as important pharmaceutical scaffolds under green conditions. The obtained nanomaterial exhibited proper catalytic activity in the above mentioned transformations through multicomponent reaction (MCR) strategies. The reactions proceeded very well in the presence of the Fe3O4@CS-TDI-Titriplex V solid acid nanomaterial in EtOH to afford the corresponding acridinediones and 2-amino-3-cyano-4H-pyran derivatives in high to excellent yields. The key advantages of the present protocol include the use of a renewable, biopolymeric and biodegradable solid acid as well as a simple procedure for the preparation of the hybrid material. Furthermore, the Fe3O4@CS-TDI-Titriplex V nanomaterial was used four times with a slight decrease in its catalytic activity.

Correlation between bilateral GFR in patients with localized renal cancer after partial nephrectomy.

To explore the relationship between the residual glomerular filtration rate (GFR) on the operated side and the GFR on the contralateral side following partial nephrectomy (PN) in patients with localized renal cell carcinoma (RCC). Following institutional review board approval, we conducted a retrospective analysis of clinical records from May 2018 to July 2023, involving 118 patients who underwent partial nephrectomy for unilateral localized kidney tumors (T1-T2). Glomerular filtration rate data were assessed using single photon emission computed tomography (SPECT)/computed tomography imaging [using 9mTc-DTPA (diethylenetriaminepentaacetic acid) renal dynamic imaging]. The independent determinants of postoperative renal function or renal function change were determined using linear regression analysis. In addition, the patient's demographic, clinical, and nephrometry characteristics were collected. A total of 58 patients were finally enrolled. The preoperative and postoperative GFR of bilateral kidneys showed a significant positive correlation. Postoperative GFR of the operated kidney was the independent predictor of GFR of contralateral kidney (p = 0.001). Tumor diameter (p = 0.036), age (p = 0.005), and postoperative GFR of the contralateral kidney (p = 0.001) were all independent predictors of postoperative GFR of the operated kidney. ΔGFR1 was the independent predictor of ΔGFR2. Results showed that a more pronounced postoperative decline in GFR on the operated side corresponded to a weaker compensatory capacity of the contralateral-side kidney. During the course of the surgical procedure, the active endeavor to safeguard the renal function of the operated kidney side holds paramount importance, which yields positive outcomes for postoperative kidney function on the contralateral side, consequently contributing to the overall preservation of renal function.

Mercapto–palygorskite decreases the Cd uptake of wheat by changing Fe and Mn fraction in Cd contaminated alkaline soil

Wheat is one of the major sources of dietary nutrition for human body, and excessive Cadmium (Cd) in wheat poses a serious risk to human health. Mercapto–palygorskite (MP) has been proven to efficiently reduce Cd stress in wheat, but the contribution of major soil oxides to the stability of soil Cd under MP treatment is unclear. Here, a wheat pot experiment was conducted to evaluate the effects of soil Fe and Mn oxides on the Cd fraction under MP treatment. The results showed that the application of MP decreased the diethylenetriaminepentaacetic acid (DTPA)–extractable Cd by 24.0–34.7 %, increased the Fe and Mn oxide-bound Cd (OX–Cd) by 5.0–12.0 % and significantly reduced the Cd content in wheat grains (17.9–69.5 %). It also decreased the soil’s free Fe and Mn oxides by 6.1–11.7 %and 6.9–12.4 %, respectively, and increased the amorphous Fe and Mn oxides by 19.3–32.5 % and 21.9–24.1 %, respectively. In addition, the application of MP increased the concentration of Fe and Cd in soil colloid by 19.3–33.3 % and 11.3–45.3 %, respectively. Correlation analysis indicated that the amorphous Fe, Mn oxides in soil had a significant positive correlation with the content of Fe and Mn bound Cd in soil (P < 0.01). Primary component analysis (PCA) analysis shows colloidal Fe and Mn on the soil available Cd had relatively high positively loadings. Meanwhile, soil colloidal Fe exhibited a significant positive correlation with colloidal Cd (P < 0.01) and amorphous Fe oxides (P < 0.01). These results indicated that MP remediated Cd-contaminated soil by promoting an increase in amorphous Fe, Mn oxides and their adsorption and precipitation of Cd on these oxides.

Evaluation of renal function with renography in patients with renal colic

Objective: Urolithiasis is responsible for the majority of urological emergencies. Although computed tomography (CT) scan can identify urinary obstruction caused by stones, there is a growing concern about exposure to radiation made by this method. Renal scintigraphy can provide valuable insights regarding the functional status of kidneys and can significantly reduce exposure to radiation.&#x0D; The goal of present study was to assess renal function through renal scintigraphy in patients with acute renal colic and it explores the association between renal scintigraphy performance and ultrasound in terms of detecting hydronephrosis.&#x0D; Methods: For this study, 20 patients with acute renal colic were chosen. Each patient underwent renal ultrasonography and subsequently received renal scintigraphy with Technetium-99m diethylenetriaminepentaacetic acid (Tc-99m DTPA). Cohen's Kappa coefficient and Cramer's V correlation were employed to demonstrate the extent of agreement between ultrasound and renal scintigraphy. &#x0D; Results: 12 (60%) patients were male. Glomerular filtration rate (GFR) values were correlated with Cockcroft-Gault equation and the Gates method (P=0.002, r=0.642). There was a good agreement and a statistically significant relationship between ultrasound and renal scintigraphy in terms of detecting obstructive uropathy in both kidneys.&#x0D; Conclusion: To conclude, GFR values were correlated between Cockcroft-Gault equation and the Gates method in patients with acute renal colic. There was a good agreement and statistically significant relationship between ultrasound and obstructive renography results in both kidneys. However, we found no association between perfusion phase of renal scintigraphy and ultrasonography in terms of hydronephrosis detection.

Design Parameters for a Mass Cytometry Detectable HaloTag Ligand.

Mass cytometry permits the high dimensional analysis of complex biological samples; however, some techniques are not yet integrated into the mass cytometry workflow due to reagent availability. The use of self-labeling protein systems, such as HaloTag, are one such application. Here, we describe the design and implementation of the first mass cytometry ligands for use with HaloTag. "Click"-amenable HaloTag warheads were first conjugated onto poly(l-lysine) or poly(acrylic acid) polymers that were then functionalized with diethylenetriaminepentaacetic acid (DTPA) lutetium metal chelates. Kinetic analysis of the HaloTag labeling rates demonstrated that the structure appended to the 1-chlorohexyl warhead was key to success. A construct with a diethylene glycol spacer appended to a benzamide gave similar rates (kobs ∼ 102 M-1 s-1), regardless of the nature of the polymer. Comparison of the polymer with a small molecule chelate having rapid HaloTag labeling kinetics (kobs ∼ 104 M-1 s-1) suggests the polymers significantly reduced the HaloTag labeling rate. HEK293T cells expressing surface-exposed GFP-HaloTag fusions were labeled with the polymeric constructs and 175Lu content measured by cytometry by time-of-flight (CyTOF). Robust labeling was observed; however, significant nonspecific binding of the constructs to cells was also present. Heavily pegylated polymers demonstrated that nonspecific binding could be reduced to allow cells bearing the HaloTag protein to be distinguished from nonexpressing cells.

Coverage, Trends, and Inequalities of Maternal, Newborn, and Child Health Indicators among the Poor and Non-Poor in the Most Populous Cities from 38 Sub-Saharan African Countries.

Rapid urbanization is likely to be associated with suboptimal access to essential health services. This is especially true in cities from sub-Saharan Africa (SSA), where urbanization is outpacing improvements in infrastructure. We assessed the current situation in regard to several markers of maternal, newborn, and child health, including indicators of coverage of health interventions (demand for family planning satisfied with modern methods, at least four antenatal care visits (ANC4+), institutional birth, and three doses of DPT vaccine[diphtheria, pertussis and tetanus]) and health status (stunting in children under 5 years, neonatal and under-5 mortality rates) among the poor and non-poor in the most populous cities from 38 SSA countries. We analyzed 136 population-based surveys (year range 2000-2019), contrasting the poorest 40% of households (referred to as poor) with the richest 60% (non-poor). Coverage in the most recent survey was higher for the city non-poor compared to the poor for all interventions in virtually all cities, with the largest median gap observed for ANC4+ (13.5 percentage points higher for the non-poor). Stunting, neonatal, and under-5 mortality rates were higher among the poor (7.6 percentage points, 21.2 and 10.3 deaths per 1000 live births, respectively). The gaps in coverage between the two groups were reducing, except for ANC4, with similar median average annual rate of change in both groups. Similar rates of change were also observed for stunting and the mortality indicators. Continuation of these positive trends is needed to eliminate inequalities in essential health services and child survival in SSA cities.

Upscale Synthesis of Magnetic Mesoporous Silica Nanoparticles and Application to Metal Ion Separation: Nanosafety Evaluation.

The synthesis of core-shell magnetic mesoporous nanoparticles (MMSNs) through a phase transfer process is usually performed at the 100-250 mg scale. At the gram scale, nanoparticles without cores or with multicore systems are observed. Iron oxide core nanoparticles (IO) were synthesized through a thermal decomposition procedure of α-FeO(OH) in oleic acid. A phase transfer from chloroform to water was then performed in order to wrap the IO nanoparticles with a mesoporous silica shell through the sol-gel procedure. MMSNs were then functionalized with DTPA (diethylenetriaminepentacetic acid) and used for the separation of metal ions. Their toxicity was evaluated. The phase transfer procedure was crucial to obtaining MMSNs on a large scale. Three synthesis parameters were rigorously controlled: temperature, time and glassware. The homogeneous dispersion of MMSNs on the gram scale was successfully obtained. After functionalization with DTPA, the MMSN-DTPAs were shown to have a strong affinity for Ni ions. Furthermore, toxicity was evaluated in cells, zebrafish and seahorse cell metabolic assays, and the nanoparticles were found to be nontoxic. We developed a method of preparing MMSNs at the gram scale. After functionalization with DTPA, the nanoparticles were efficient in metal ion removal and separation; furthermore, no toxicity was noticed up to 125 µg mL-1 in zebrafish.

Use of Rapid Antigen Triple Test Nasal Swabs (COVID-VIRO ALL-IN TRIPLEX: Severe Acute Respiratory Syndrome Coronavirus 2, Respiratory Syncytial Virus, and Influenza) in Children With Respiratory Symptoms: A Real-life Prospective Study.

In autumn 2022, the epidemics due to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), respiratory syncytial virus (RSV), and influenza overlapped, and these diseases can present with the same symptomatology. The use of a triple antigen test (SARS-CoV-2 + influenza A/B + RSV) seems crucial for accurate viral diagnosis in the context of implementing long-acting monoclonal antibody vaccination against RSV in the upcoming RSV season. We assessed the usefulness of the triple test in real life in this prospective study performed from October 2022 to May 2023 and involving 116 pediatricians (2 emergency department pediatricians and 114 ambulatory pediatricians). Children <15 years old with flu-like illness (with fever), bronchiolitis (dyspnea ± wheezing), otitis, and croup were enrolled and sampled with a nasal triple test. For 8329 children with flu-like illness (65.3%), bronchiolitis (17.9%), otitis (8.8%), and croup (6.3%), the use of the triple test led to a viral diagnosis in 47.9% of cases. The highest RSV positivity occurred in children with bronchiolitis (32.9%). The highest influenza A and B positivity (24.6% and 19.6%) occurred in children with flu-like illness. A succession of 3 epidemics (RSV and influenza A and B) occurred over time with several overlap periods. The triple test allowed for a viral diagnosis in half of our cases. The upcoming introduction of RSV prevention will emphasize the need for active surveillance with viral results both in ambulatory settings and hospitals. Clinical Trials Registration. NCT0441231.

Micronutrient Fe and Mn uptake from peat by marigold and petunia

Peat substrates have the potential to function as micronutrient sources such as iron (Fe) and manganese (Mn). Typically, when planning fertilization program for crops, the components of peat substrates are not taken into account. The objective was to quantify potentially plant-available micronutrients of Fe and Mn from peat substrates by floriculture species when no additional Fe and/or Mn were applied in the fertilizer solution. Greenhouse experiments were conducted using Tagetes erecta ‘Atlantis Primrose’ marigold (iron-efficient) and Petunia x hybrida ‘Celebrity Pink Morn’ petunia (iron-inefficient) to compare extractable Fe and Mn from two peat sources with actual plant uptake of these nutrients by the plants. In Experiment 1, marigold was grown hydroponically in plastic tubs using four different nutrient solutions: complete, without Fe, without Mn, and without both Fe and Mn. Within a period of less than two weeks after transplant, the absence of Fe and Mn severely limited marigold growth. The hydroponic study highlighted the importance of providing both Fe and Mn nutrients immediately after sowing to support normal marigold growth. In Experiment 2, both marigold and petunia were grown from seed in two peat substrates (Blackmore seedling peat “BM peat” and Sunshine Professional Black Bale peat “SG peat”) and an acid-washed sand substrate. Each peat was limed at 3 g.L−1 of reagent grade CaCO3 resulting in an initial substrate-pH of 5.0 for SG peat and 5.5 for BM peat. Four nutrient solutions [(a) complete, or complete with (b) no Fe, (c) no Mn, and (d) no Fe or Mn] were applied with each irrigation without leaching. Initial substrate nutrient levels were extracted using the SME (saturated medium extract) method using either water (SMEW) or 0.005 M DTPA (diethylenetriamine-pentaacetic acid, SMED) as extractants. Over a 5-week period (during the vegetative, non-blooming stage), peat substrates provided sufficient Fe and Mn for marigold, but iron deficiency symptoms were observed in marigolds grown in sand without Fe fertilizer. Petunia plants developed iron deficiency symptoms in all substrates without Fe fertilizer. The absence of Mn fertilizer, however, did not have a significant impact on petunia growth and health, indicating that peat substrates likely provided adequate Mn for non-symptomatic petunia plant growth. The micronutrient Fe and Mn budget analysis suggested that the SMEW method underestimated the availability of Fe and Mn to the plants, whereas the SMED method may have overestimated the extractable Fe and Mn levels in relation to the actual tissue uptake. Overall, the peat substrates showed a high potential for providing Fe and Mn in quantities sufficient for the initial growth of iron-efficient marigold, but was inadequate for iron-inefficient petunia.

Deep learning-based attenuation correction method in 99mTc-GSA SPECT/CT hepatic imaging: a phantom study.

This study aimed to evaluate a deep learning-based attenuation correction (AC) method to generate pseudo-computed tomography (CT) images from non-AC single-photon emission computed tomography images (SPECTNC) for AC in 99mTc-galactosyl human albumin diethylenetriamine pentaacetic acid (GSA) scintigraphy and to reduce patient dosage. A cycle-consistent generative network (CycleGAN) model was used to generate pseudo-CT images. The training datasets comprised approximately 850 liver phantom images obtained from SPECTNC and real CT images. The training datasets were then input to CycleGAN, and pseudo-CT images were output. SPECT images with real-time CT attenuation correction (SPECTCTAC) and pseudo-CT attenuation correction (SPECTGAN) were acquired. The difference in liver volume between real CT and pseudo-CT images was evaluated. Total counts and uniformity were then used to evaluate the effects of AC. Additionally, the similarity coefficients of SPECTCTAC and SPECTGAN were assessed using a structural similarity (SSIM) index. The pseudo-CT images produced a lower liver volume than the real CT images. SPECTCTAC exhibited a higher total count than SPECTNC and SPECTGAN, which were approximately 60% and 7% lower, respectively. The uniformities of SPECTCTAC and SPECTGAN were better than those of SPECTNC. The mean SSIM value for SPECTCTAC and SPECTGAN was 0.97. We proposed a deep learning-based AC approach to generate pseudo-CT images from SPECTNC images in 99mTc-GSA scintigraphy. SPECTGAN with AC using pseudo-CT images was similar to SPECTCTAC, demonstrating the possibility of SPECT/CT examination with reduced exposure to radiation.

Impact of chelating agents on precursor formation and efficiency of Ni/MgO-Al2O3 catalysts in dry reforming of methane

Using cheap and non-toxic chelating agents during catalyst preparation is considered as an effective tool to control the particle size and to strengthen the metal-support interactions (MSI), while keeping the simplicity of the selected preparation method. The previous properties are useful to improve the catalyst activity, stability, and selectivity in dry reforming of methane (DRM). Therefore, we prepared a series of low Ni loading (2.5 wt%) catalysts supported over MgO-Al2O3 (Mg/Al = 1.3) mixed oxide using the classic wet impregnation method modified with chelating agents (citric acid (CA), tartaric acid (TA) and diethylenetriaminepentaacetic acid (DTPA)) and subsequently evaluated these in DRM. Intensive catalyst characterization (ICP, BET, XRD, XPS, STEM, H2-TPR and O2-TPO) suggested the presence of different structure-activity relationships. Particularly, using chelating agents during catalyst preparation controlled the final particle size range, which in turn played a pivotal role in shaping the strength of the metal support interactions (MSI). These impacts were crucial to improve the activity, stability and to control the formation of coke deposits. Moreover, special focus was put on the catalytic testing of the outperforming sample (Ni(TA)/Mg1.3AlOx) prepared using tartaric acid as chelating agent under severe regimes prone to catalyst deactivation to demonstrate the benefits of the proposed preparation technique.

Preparation of barium sulfate chelating agent DTPA-5Na and molecular dynamics simulation of chelating mechanism.

Barium sulfate (BaSO4) scale is dense and hard, making it difficult to remove using conventional acid and alkali treatments. Diethylenetriaminepentaacetic acid (DTPA) and its complexes have been identified as important chelating agents for the removal of BaSO4 scale. However, DTPA has good solubility only under strong alkali conditions, which in turn exacerbate scaling. To improve the solubility and chelation effectiveness of DTPA, penta sodium diethylenetriamine-pentaacetate (DTPA-5Na) was synthesized using chloroacetic acid, diethylenetriamine, sodium carbonate, and sodium hydroxide as raw materials. The structure of DTPA-5Na was characterized by infrared spectroscopy and 1H-NMR, and its chelation effectiveness was evaluated. Experimentation demonstrated that under conditions of 50 °C and with a molar ratio of chloroacetic acid (ClCH2COOH), sodium carbonate (Na2CO3), sodium hydroxide (NaOH), and diethylenetriamine (DETA) of 5.00 : 2.50 : 5.25 : 1.00, the reaction for 6 hours resulted in the optimal chelation value of DTPA-5Na at 76.8 mg CaCO3·per g. Analysis of the chelation and dissolution of BaSO4 scale using DTPA-5Na and microstructural scanning electron microscopy of the BaSO4 crystal indicate that DTPA-5Na functions through solubilization, lattice distortion, and flaking dispersion to remove BaSO4. Molecular dynamics simulation software was used to simulate the chelation mechanism of DTPA-5Na, where the results indicated strong adsorption of DTPA-5Na to the surface of BaSO4. The adsorption energy follows the order of (120) surface > (001) surface > (100) surface > (210) surface. The adsorption is mainly a result of the interaction between the carboxylic "O" atom in DTPA-5Na and the (001), (100), and (120) surfaces of BaSO4 scale, while N atoms in DTPA-5Na structure primarily interact with the (210) surface. The adsorption of "O" atoms is stronger than that of "N" atoms in the DTPA-5Na structure.