Effect of Halomonas titanicae on fluctuating water-line corrosion of EH40 steel.

The fluctuating water-line corrosion of EH40 steel in sterile and biotic media was investigated with a wire beam electrode. When the coupons were partially immersed in the sterile medium, the position of the low water-line acted as the cathodic zone and the area below the low water-line constantly served as the main anodic zone. The thin electrolyte layers with uneven thickness promoted the galvanic current of the region below the low water-line. Different from the sterile environment, the metabolism of Halomonas titanica with oxygen as the final electron acceptor reduced the dissolved oxygen concentration, which resulted in the position of the low water-line acting as the anodic zone.

The impact of alloying element Cu on corrosion and biofilms of 316L stainless steel exposed to seawater.

Copper-containing stainless steel (SS) has been reported to mitigate biofilms in industrial and clinical environments. However, the impact of copper released from copper-containing SS in natural seawater on biofilms and corrosion is still unclear. In this study, three kinds of 316L SS were immersed in natural seawater for 6 months, and the pitting depth decreased in the order: 316L-Cu SS (annealed) > 316L SS > 316L-Cu SS (aged). The biofilm thickness and number of sessile cells on the surface of 316L-Cu SS (annealed) and 316L SS were similar but notably greater than those of 316L-Cu SS (aged). Furthermore, the results of the community analysis indicated that the addition of copper in 316L-Cu SS (aged) reduced the diversity and richness of the microbial community, resulting in a significant reduction in the number of genera constituting the biofilms. Copper ions exhibit a broad-spectrum bactericidal effect, effectively reducing the abundance of dominant populations and microbial genera in the biofilms, thereby mitigating pitting corrosion induced by microorganisms. In addition, the PCoA scatter plot showed that time also played an important role in the regulation of microbial community structure.

Development and validation of a diagnostic nomogram model for predicting monoclonal gammopathy of renal significance.

In patients with kidney disease, the presence of monoclonal gammopathy necessitates the exploration of potential causal relationships. Therefore, in this study, we aimed to address this concern by developing a nomogram model for the early diagnosis of monoclonal gammopathy of renal significance (MGRS). Univariate and multivariate logistic regression analyses were employed to identify risk factors for MGRS. Verification and evaluation of the nomogram model's differentiation, calibration, and clinical value were conducted using the receiver operating characteristic (ROC) curve, calibration curve, and decision curve analysis. The study encompassed 347 patients who underwent kidney biopsy, among whom 116 patients (33.4%) were diagnosed with MGRS and 231 (66.6%) with monoclonal gammopathy of undetermined significance. Monoclonal Ig-related amyloidosis (n = 86) and membranous nephropathy (n = 86) was the most common renal pathological type in each group. Notably, older age, abnormal serum-free light chain ratio, and the absence of microscopic hematuria were identified as independent prognostic factors for MGRS. The areas under the ROC curves for the training and verification sets were 0.848 and 0.880, respectively. In conclusion, the nomogram model demonstrated high accuracy and clinical applicability for diagnosing MGRS, potentially serving as a valuable tool for noninvasive early MGRS diagnosis.

Corrosion of Pseudomonas aeruginosa toward a Cu-Zn-Ni alloy inhibited by the simulative tidal region.

The corrosion of marine engineering equipment not only threatens human security and ecological environment but also increases energy consumption, restricting the sustainable development of marine economies and industries. The tidal region is a complex and challenging environment that can cause severe corrosion of facilities and affect microbial activities. However, the current understanding of the mechanisms underlying microbiologically influenced corrosion (MIC) of tidal region is insufficient. To address this issue, the effect of Pseudomonas aeruginosa on a Cu-Zn-Ni alloy in the simulative tidal region was investigated by chemical and molecular biological analysis in this study. The results demonstrated that P. aeruginosa formed thicker biofilms on the Cu-Zn-Ni alloy samples under the full exposure, accelerating corrosion compared to sterile controls. Interestingly, the corrosion of P. aeruginosa toward the Cu-Zn-Ni alloy was inhibited in the simulative tidal region. This inhibition behavior was relevant to the reduction in the quantity of sessile cells and cell activities. The expression down-regulation of genes encoding phenazines induced the decrease in electron transfer mediators and weakened the MIC of P. aeruginosa on alloy samples in the simulative tidal region. The research sheds light on the characteristics of P. aeruginosa and corrosion products on the Cu-Zn-Ni alloy, as well as their interaction mechanisms underlying corrosion in the simulative tidal region. The study will facilitate the evaluation and control of MIC in the tidal region, contributing to the development of sustainable strategies for preserving the integrity and safety of marine facilities.

Enhancing Electrocatalytic Performance via Thickness-Tuned Hollow N-Doped Mesoporous Carbon with Embedded Co Nanoparticles for Oxygen Reduction Reaction.

Improving catalytic performance relies heavily on the rational design of the spatial structure of electrocatalysts, achieved through exposure of active sites, acceleration of the charge/mass transfer rate, and confinement of the reactants. In this study, we have fabricated Co nanoparticles embedded in overhang eave-like hollow N-doped mesoporous carbon (Co@EMPC) by adjusting the thickness of mesoporous polydopamine (mPDA). Thanks to the abundance of short mesoporous channels within the porous structure and the tuned electronic properties resulting from heterojunction structures between metal and carbon, the prepared Co@EMPC provides increased accessibility to active sites and enhanced mass and charge transfer rates. These features contribute to superior performance in the oxygen reduction reaction (ORR), with a half-wave potential of 0.874 V vs RHE, as well as exceptional durability in alkaline media. This study introduces a useful approach to enhance the ORR using eave-like hollow nanoreactors.

Rare presentation of esophageal squamous cell carcinoma with rectal metastasis: A case report.

Esophageal cancer is usually diagnosed at an advanced stage, resulting in poor survival. The common sites of distant metastasis include lung, liver and bones. The present study reports a rare case of esophageal squamous cell carcinoma (SCC) with rectal metastasis. A 65-year-old man was diagnosed with middle thoracic esophageal SCC with multiple lymph node metastasis. The patient achieved good response after chemoradiotherapy and adjuvant chemotherapy. During following up, the computed tomography and magnetic resonance scans showed a mass in front of the rectum with intact mucosa. Biopsies were performed and histopathological findings showed SCC, consistent with metastasis from primary esophageal SCC. The patient subsequently received palliative chemoradiotherapy to the rectal tumour and survived for 5 months. To the best of our knowledge, the present case is the first report of metastatic rectal SCC from the esophagus. It is important to take a biopsy of this unexpected lesion for histological analysis, which can help to discriminate metastatic from primary cancer. The goal of treatment is palliative therapy to improve quality of life and survival for this metastatic disease.

Camrelizumab combined with apatinib in the treatment of patients with hepatocellular carcinoma: a real-world assessment.

Although a phase II clinical trial confirmed that camrelizumab combined with apatinib is effective in patients with hepatocellular carcinoma (HCC), we generally lack data on the results of this regimen in real-world clinical practice. In this study, the efficacy and safety of camrelizumab combined with apatinib in the treatment of patients with HCC were re-evaluated. Data from 86 patients with HCC were collected and combinatorically treated with camrelizumab and apatinib at the First Affiliated Hospital of Anhui Medical University, Hefei, Anhui Province, China. The objective remission rate and disease control rate were 25.6% and 72.1%, respectively. The median progression-free survival was 5 months (95% CI 3.7-6.3 months), and the median overall survival time was 19.0 months (95% CI 16.9-21.1 months). The 12- and 18-month survival rates were 70.9% and 54.2%, respectively. The most common grade 3-4 adverse events were hypertension (24.4%), thrombocytopenia (16.3%), and hyperbilirubinemia (9.3%). Multivariate regression analysis showed that operation history was an independent risk factor for overall survival.

A computational study on the coordination modes and electron absorption spectra of the complexes U(iv) with N,N,N',N'-tetramethyl-diglycolamide and anions.

Lipophilic N,N,N',N'-tetraalkyl-diglycolamides (TRDGAs) are promising extractants for actinides separation in spent nuclear fuel reprocessing. Usually, in the extracted complexes of actinide and lanthanide ions of various oxidation states, the metal ions are completely surrounded by 2 or 3 TRDGA molecules, and the counter anions do not directly coordinate with them. In contrast, the extracted complexes of U(iv) from different media presenting different absorption spectra indicate that the anions (Cl- and NO3-) are directly involved in the coordination with U(iv) in the first inner sphere. Based on this exceptional observation in solvent extraction, taking the coordination of U(iv) with N,N,N',N'-tetramethyl-diglycolamide (TMDGA, the smallest analogue of TRDGA) as the research object, we mimic the behaviours of counterions (Cl- and NO3-) and the water molecule during coordination of TMDGA with U(iv), especially combining with the simulation of the absorption spectra. We demonstrate that during the complexing of TMDGA to U(iv), the counterion Cl- will occupy one coordination number in the inner coordination sphere, and NO3- will occupy two by bidentate type; however, the ubiquitous water cannot squeeze in the inner coordination sphere. In addition, the coordination of Cl- and NO3- is proved to favour the extraction with the lower binding energy. Moreover, the simulation of absorption spectra is in good agreement with the observation from experiments, further verifying the aforementioned conclusion. This work in some way will provide guidance to improve the computation methods in research of actinides by mimicking the absorption spectra of actinide ions in different complexes.

Assessing the effectiveness of camrelizumab plus apatinib versus sorafenib for the treatment of primary liver cancer: a single-center retrospective study.

Although the effectiveness of camrelizumab plus apatinib has been confirmed in a phase II clinical study, the efficacy of camrelizumab plus apatinib versus sorafenib for primary liver cancer (PLC) remains unverified. We retrospectively collected the data of 143 patients with PLC who received camrelizumab plus apatinib or sorafenib as the first-line treatment at The First Affiliated Hospital of Anhui Medical University from April 2018 to November 2021. Of these, 71 patients received an intravenous injection of camrelizumab 200 mg (body weight ≥ 50 kg) or 3 mg/kg (body weight < 50 kg) followed by an oral dosage of apatinib 250 mg/day every 3 weeks and 72 patients received sorafenib 400 mg orally, twice a day in 28-day cycles. The primary outcomes were overall survival and progression-free survival. The secondary outcomes were objective response rate, disease control rate, and safety. The median median progression-free survival and median overall survival with camrelizumab plus apatinib and sorafenib were 6.0 (95% confidence interval (CI) 4.2-7.8) and 3.0 months (95% CI 2.3-3.7) and 19.0 (95% CI 16.4-21.6) and 12.0 months (95% CI 8.9-15.1), respectively (death hazard ratio: 0.61, P = 0.023). Grade 3/4 treatment-related adverse events were noted in 50 (70.4%) patients in the camrelizumab plus apatinib group and 19 (26.4%) patients in the sorafenib group. Two treatment-related deaths were recorded. Clinically significant improvements were observed in overall survival and progression-free survival with camrelizumab plus apatinib versus sorafenib. Although the side effects of camrelizumab plus apatinib are relatively high, they can be controlled.

Sulfate template induced S/O doped carbon nanosheets enabling rich physi/chemi-sorption sites for high-performance zinc ion hybrid capacitors.

Zinc ion hybrid capacitors (ZIHCs) are encouraging energy storage devices for large-scale applications. Nevertheless, the electrochemical performance of ZIHCs is often limited by the cathode materials which show low energy density and rate capability practically. One of the efficient strategies to overcome these challenges is the development of advanced carbon cathode materials with abundant physi/chemisorption sites. Herein, we develop a sulfate template strategy to prepare sulfur and oxygen doped carbon nanosheets (SOCNs) as a potential cathode active material for ZIHCs. The as-prepared SOCNs exhibit porous architectures with a large surface area of 1877 m2 g-1, substantial structural defects, and high heteroatom-doped contents (O: 7.9 at%, S: 0.7 at%). These exceptional features are vital to enhancing Zn ion storage. Consequently, the SOCN cathode shows a high capacity of 151 mAh g-1 at 0.1 A g-1, high cycle stability with 83% capacity retention at 5 A g-1 after 4000 cycles, and a superior energy density of 103.1 Wh kg-1. We also investigate the dynamic adsorption/desorption behaviors of Zn ions and anions of the ZIHCs carbon electrodes during the process of charge and discharge by ex-situ experiments. This work highlights the significance of the integration with a large specific surface area and bountiful heteroatoms in carbon electrodes for achieving high-performance ZIHCs.

Revealing the Chemical Nature of Functional Groups on Graphene Oxide by Integrating Potentiometric Titration and Ab Initio Calculations.

A new graphene oxide (GO) model with reasonable functional group types and distribution modes was proposed by integrating potentiometric titrations and ab initio calculations. Due to the complex synthesis mechanism, the atomic structure of GO has been controversial for a long time. Here, we use density functional theory calculations to mimic the oxidation process, and a series of GO fragments (GOFs) were deduced. A new pKa calculation method (RCDPKA) developed specifically in this work was further used to predict pKa values of the fragments. Then, we performed potentiometric titrations on four different GO samples to confirm the existence of these GOFs and determine the content of functional groups. Interestingly, different GO samples present the same pKa values in titration, and the results are consistent with the predicted ones. Based on the evidence from titration and calculation, prominent correlations between functional groups could be found. Groups at the edges are mainly double-interactive carboxyls (pKa1 ≈ 3.4, pKa2 ≈ 5.7) and double-adjacent phenolic hydroxyls (pKa1 ≈ 8.8, pKa2 ≈ 12.1), while groups on the plane are mainly collocated epoxies and hydroxyls (pKa1 ≈ 11.1, pKa2 ≈ 13.8) on both sides of the plane with a meta-positional hydrogen bond interaction. These findings were further validated by multiple characterizations and GO modifications. These results not only stimulate a fundamental understanding of the GO structure but also provide a quantitative analysis method for functional groups on GO.

Prognostic nomogram and risk factors for predicting survival in patients with pT2N0M0 esophageal squamous carcinoma.

This study analyzed the impact of factors affecting overall survival in patients with pT2N0M0 esophageal squamous carcinoma (ESCC) and developed a nomogram to predict overall survival (OS). We reviewed the clinical data of 413 patients with pathological T2N0M0 ESCC after radical esophagectomy in two hospitals. Data from one institution was used as the training cohort. A nomogram was established using Cox proportional hazard regression for identifying the prognostic factors affecting for OS in ESCC patients. The area under the curve (AUC), calibration curves and decision curve analysis (DCA) were used to evaluate prognostic efficacy, which was validated in an independent validation cohort. In the training cohort (N = 304), the median OS was 69.33 months, and the 3-, 5- and 10-year OS rates were 76.80%, 67.00% and 56.90%, respectively. The median OS of the validation cohort (N = 109) was 73.50 months, and the 3-, 5- and 10-year OS rates were 77.00%, 67.80% and 55.60%, respectively. According to Cox univariate and multivariate analyses, sex, age, tumor length and the number of resected lymph nodes were identified as predictors of OS. We developed nomograms and performed internal and external validation. The time-dependent receiver operating characteristic (ROC) curve and area under the curve (AUC) value, calibration curve and decision curve analysis (DCA) showed good prediction ability of the nomogram. The developed nomogram can effectively predict OS after esophagectomy in patients with pT2N0M0 ESCC.

Monotropein: A comprehensive review of biosynthesis, physicochemical properties, pharmacokinetics, and pharmacology.

Monotropein, a principal natural compound in iridoid glycosides extracted from Morindae officinalis radix, has potent pharmacological activities. To understand and utilize monotropein, we systematically summarized the studies on monotropein, including its biosynthetic pathway, physicochemical properties, pharmacokinetics, and pharmacology. Interestingly, we found that the multiple bioactivities of monotropein, such as anti-osteoporosis, anti-inflammation, anti-oxidation, anti-nociception, and hepatic or renal protection, are closely associated with its capability of downregulating the nuclear factor-κB signaling pathway, inhibiting the mitogen-activated protein kinase signaling pathway, attenuating the activation of nuclear factor E2-related factor 2/heme oxygenase-1 signaling pathway, and regulating the mammalian target of rapamycin/autophagy signaling pathway. However, the clinically therapeutic effects and the potential problems need to be addressed. This review highlights the current research progress on monotropein, which provides a reference for further investigation of monotropein.

Particle size optimization of metal-organic frameworks for superior capacitive deionization in oxygenated saline water.

Pyrolysis-free metal-organic frameworks (MOFs) with optimized particle sizes were used as capacitive deionization (CDI) materials in oxygenated saline water. Upon decreasing the particle size of the MOFs, excellent cycling stability and higher CDI performance were achieved. This was possibly due to the improvement in charge transfer and electrolyte permeation, uncovering the significance of particle size control in improving CDI performance.

Effects of Pseudomonas aeruginosa on EH40 steel corrosion in the simulated tidal zone.

Corrosion of metals in the tidal zone shortens the service life of facilities considerably and causes extensive economic losses each year. However, the contribution of microbiologically influenced corrosion (MIC) to this progress is usually ignored, and consequently the research on the mechanism of MIC in the tidal zone is highly desirable. In this study, the impact of the typical marine strain Pseudomonas aeruginosa on EH40 steel corrosion in the simulated tidal zone was evaluated. P. aeruginosa accelerated the corrosion of EH40 steel in the simulated tidal zone and its corrosion promotion efficiency rose over time. The environmental stress promoted the metabolism, energy production, and secretion of phenazines of P. aeruginosa, which promoted extracellular electron transfer between bacteria and steel, and accelerated MIC. The study proposes a possible mechanism of MIC in the tidal zone at the molecular biological level, which is of theoretical significance for evaluating the corrosion risks of marine equipment.

Study of Anticorrosion and Antifouling Properties of a Cu-Doped TiO2 Coating Fabricated via Micro-Arc Oxidation.

As a promising material for petroleum industrial applications, titanium (Ti) and its alloys receive wide attention due to their outstanding physicochemical properties. However, the harsh industrial environment requires an antifouling surface with a desired corrosion resistance for Ti and its alloys. In order to achieve the desired antifouling properties, micro-arc oxidation (MAO) was used to prepare a Cu-doped TiO2 coating. The microstructure of the Cu-doped TiO2 coating was investigated by TF-XRD, SEM, and other characterization techniques, and its antifouling and anticorrosion properties were also tested. The results show the effects of the incorporation of Cu (~1.73 wt.%) into TiO2 to form a Cu-doped TiO2, namely, a Ti-Cu coating. The porosity (~4.8%) and average pore size (~0.42 µm) of the Ti-Cu coating are smaller than the porosity (~5.6%) and average pore size (~0.66 µm) of Ti-blank coating. In addition, there is a significant reduction in the amount of SRB adhesion on the Ti-Cu coating compared to the Ti-blank coating under the same conditions, while there is little difference in corrosion resistance between the two coatings. There, the addition of copper helps to improve the fouling resistance of TiO2 coatings without compromising their corrosion resistance. Our work provides a practical method to improve the antifouling function of metallic Ti substrates, which could promote the application of Ti in the petroleum industry.

Patterns of care and prognostic evaluation for stage I-III upper esophageal squamous cell carcinoma: a population-based study.

Background: There is no strong evidence regarding the optimal treatment and specific prognosis prediction model for upper esophageal squamous cell carcinoma (UESCC). This study aimed to investigate the real-world treatment patterns and develop models to predict overall survival (OS) and esophageal cancer-specific survival (ECSS) in patients with stage I-III UESCC. Methods: Patients with T1-4N0-3M0 UESCC in the Surveillance, Epidemiology, and End Results (SEER) database were identified from 2010 to 2017, and randomized to a training cohort and a validation cohort. The effect of treatment patterns on survival were comprehensively analyzed. Nomograms were developed by incorporating independent prognostic factors analyzed by Cox regression in the training cohort and evaluated by the concordance index (C-index), receiver operating characteristic (ROC) curves, calibration curves, and decision curve analyses (DCA) in two cohorts. Results: A total of 677 patients were identified, including 452 in the training cohort and 225 in the validation cohort. Among all populations, 71.9% (487) received chemoradiotherapy without surgery, and chemoradiotherapy or/and surgery showed better survival than other treatments. However, surgery was rarely carried out for patients with stage II-III. T stage, N stage, surgery, chemotherapy, and radiotherapy were independent risks for both OS and ECSS, while age was also an independent risk for OS. The C-indexes for nomograms to predict OS (0.71 and 0.72) and ECSS (0.70 and 0.73) were greater than 7th AJCC staging system to predict OS (0.61 and 0.64) and ECSS (0.64 and 0.64) in both the training cohort and the validation cohort. Time-dependent ROC curves and DCA also suggested that nomograms performed consistently better than 7th AJCC staging system. The calibration curves demonstrated good consistency in predicting survival. Conclusions: Chemoradiotherapy was a major treatment with preferable survival for patients with stage I-III UESCC. We have firstly developed and validated prognostic nomograms in patients with stage I-III UESCC, which would play a supplementary role in the current staging system.

The Evaluation of Xiaozeng Qianggu Tablets for Treating Postmenopausal Osteoporosis via up-Regulated Autophagy.

Objective: Postmenopausal osteoporosis (PMOP) is a common age-associated disease in the life course. Clinically, Xiaozeng Qianggu Tablets (XQT) have a potent therapeutic effect on the PMOP. However, the bioactive components and the mechanism of XQT underlying the PMOP treatment were unclear and it should be explored to discover the scientific connotation in traditional medical practice. Methods: The components in XQT were identified by UPLC-Q-TOF/MS. The animal model of PMOP was established by surgical ovariectomy in the female Sprague-Dawley rats. After treatment of XQT, the therapeutic effect was assessed by the determination of bone metabolism biomarkers in serum and histopathological examination. The effect of XQT on the autophagy and bone micro-situation were tested using western blot, RT-qPCR, and transmission electron microscope. Results: There were 27 compounds identified in XQT, including catalpol, monotropein, verbascoside, cryptochlorogenic acid, 5,7-dihydroxychromone 7-rutinoside, biorobin, and so on. The bone metabolism markers (alkaline phosphatase, bone alkaline phosphatase, procollagen type I intact N-terminal propeptide, cross-linked carboxy-terminal telopeptide of type I collagen, and tartrate-resistant acid phosphatase) were significantly increased in the PMOP rats and reversed by XQT administration. Moreover, the width of bone trabeculae and the ratio of the area of calcium deposition to bone trabeculae were also improved after treating the middle dose of XQT. Meanwhile, the bone micro-structure was improved by XQT. The mRNA and protein expression of unc-51 like kinase 1, beclin-1, and microtubule-associated protein 1B-light chain 3 in PMOP rats were down-regulated and up-regulated by XQT administration. Conclusions: The compounds in XQT, including catalpol, monotropein, verbascoside cryptochlorogenic acid, and so on, were valuable for further pharmacy evaluation. The pathological changes and bone micro-structure were improved by XQT, and the down-regulated autophagy level was also restored, which suggested a potent effect of XQT on treating PMOP, corresponding to its clinic use.

CircRTN1 acts as a miR-431-5p sponge to promote thyroid cancer progression by upregulating TGFA.

PURPOSE: This study aimed to explore the role and underlying mechanism of circular RNA (circRNA) reticulon 1 (circRTN1) in thyroid cancer (TC). METHODS: The expression levels of circRTN1, microRNA-431-5p (miR-431-5p), and transforming growth factor-alpha (TGFA) mRNA were measured by quantitative real-time PCR (qRT-PCR). Cell proliferation was evaluated using colony formation and 5-ethynyl-2'-deoxyuridine (EdU) assays. Cell apoptosis was analyzed using flow cytometry. Cell migration and invasion were measured using the transwell assay. The protein levels of ki-67, Bax, matrix metalloproteinase 2 (MMP-2), and TGFA were detected using Western blot assay. The interaction between miR-431-5p and circRTN1 or TGFA was verified by dual-luciferase reporter assay and RNA immunoprecipitation (RIP) assay. The effect of circRTN1on TC in vivo was explored via xenograft tumor assay. RESULTS: The expression of circRTN1 was increased in TC tissues and cells. Knockdown of circRTN1 suppressed TC cell proliferation, migration, and invasion, and increased cell apoptosis. MiR-431-5p was a target of circRTN1, and miR-431-5p downregulation reversed the role of circRTN1 knockdown in TC cells. TGFA was identified as a direct target of miR-431-5p, and miR-431-5p exerted the anti-tumor role in TC cells by downregulating TGFA. Moreover, circRTN1 sponged miR-431-5p to regulate TGFA expression. Furthermore, circRTN1 knockdown inhibited tumor growth in vivo. CONCLUSION: CircRTN1 acted as a cancer-promoting circRNA in TC by regulating the miR-431-5p/TGFA axis, providing a potential therapeutic strategy for TC treatment.

Identifying the Missing Protonated Complex Species and Revisiting the Overestimated Stability Constants of Two Known Complexes of Uranyl(VI) with Dipicolinic Acid.

The complexation of uranium(VI) [U(VI)] with dipicolinic acid was revisited with respect to the missing protonated complex species existing in acidic solutions. For the first time, the presence of the protonated complex, UO2HL+, in aqueous solutions was confirmed and the stability constant was determined by fluorescence spectroscopy. Considering the protonated species, which was missing in previous investigations, the overestimated stability constants of the two known complexes, UO2L and UO2L22-, were carefully reevaluated with potentiometry using N-(2-hydroxyethyl)ethylenediamine-N,N',N'-triacetic acid as a competing ligand. While a single crystal of the solid compound UO2(HL)2(H2O)4 with two monoprotonated HL- bonding UO22+ in a tridentate mode was successfully grown from aqueous solutions, the corresponding complex species UO2(HL)2(aq) could not yet be clearly identified and characterized.