Electrochemical-coupled sulfur-driven autotrophic denitrification for nitrogen removal from raw landfill leachate: Evaluation of performance and mechanisms.

The cost-effective and environment-friendly sulfur-driven autotrophic denitrification (SdAD) process has drawn significant attention for advanced nitrogen removal from low carbon-to-nitrogen (C/N) ratio wastewater in recent years. However, achieving efficient nitrogen removal and maintaining system stability of SdAD process in treating low C/N landfill leachate treatment have been a major challenge. In this study, a novel electrochemical-coupled sulfur-driven autotrophic denitrification (ESdAD) system was developed and compared with SdAD system through a long-term continuous study. Superior nitrogen removal performance (removal efficiency of 89.1 ± 2.5 %) was achieved in ESdAD system compared to SdAD process when treating raw landfill leachate (influent total nitrogen (TN) concentration of 241.7 ± 36.3 mg-N/L), and the effluent TN concentration of ESdAD bioreactor was as low as 24.8 ± 5.1 mg-N/L, which meets the discharge standard of China (< 40 mg N/L). Moreover, less sulfate production rate (1.3 ± 0.2 mg SO42--S/mgNOx--N vs 1.7 ± 0.2 mg SO42--S/mgNOx--N) and excellent pH modulation (pH of 6.9 ± 0.2 vs 5.8 ± 0.4) were also achieved in the ESdAD system compared to SdAD system. The improvement of ESdAD system performance was contributed to coexistence and interaction of heterotrophic bacteria (e.g., Rhodanobacter, Thermomonas, etc.), sulfur autotrophic bacteria (e.g., Thiobacillus, Sulfurimonas, Ignavibacterium etc.) and hydrogen autotrophic bacteria (e.g., Thauera, Comamonas, etc.) under current stimulation. In addition, microbial nitrogen metabolic activity, including functional enzyme (e.g., Nar and Nir) activities and electron transfer capacity of extracellular polymeric substances (EPS) and cytochrome c (Cyt-C), were also enhanced during current stimulation, which facilitated the nitrogen removal and maintained system stability. These findings suggested that ESdAD is an effective and eco-friendly process for advanced nitrogen removal for low C/N wastewater.

Factors affecting cognitive frailty improvement and progression in Taiwanese older adults.

BACKGROUND: Knowledge of predictors of cognitive frailty (CF) trajectories is required to develop preventive strategies to delay or reverse the progression from CF to dementia and other adverse outcomes. This 2-year prospective study aimed to investigate factors affecting the progression and improvement of CF in older Taiwanese adults. METHODS: In total, 832 community-dwelling people aged ≥ 65 years were eligible. Fried's five frailty criteria were used to measure prefrailty and frailty, while cognitive performance was assessed by the Clinical Dementia Rating and Mini-Mental State Examination. Each component of reversible CF and potentially reversible CF was assigned a score, with a total score ranging 0 to 5 points. Two annual follow-up CF assessments were conducted. The group-based trajectory model was applied to identify latent CF trajectory groups, and a multinomial logistic regression was used to examine relationships of explanatory variables with CF trajectories. RESULTS: According to data on 482 subjects who completed the two annual follow-ups, three CF trajectories of robust, improvement, and progression were identified. After adjusting for the baseline CF state, CF progression was significantly associated with an older age (odds ratio [OR] = 1.08; 95% confidence interval [CI], 1.02 ~ 1.14), a lower Tinetti balance score (OR = 0.72; 95% CI, 0.54 ~ 0.96), a slower gait (OR = 0.98; 95% CI, 0.97 ~ 0.99), and four or more comorbidities (OR = 2.65; 95% CI, 1.19 ~ 5.90), while CF improvement was not significantly associated with any variable except the baseline CF state. In contrast, without adjusting for the baseline CF state, CF progression was significantly associated with an older age, female sex, balance scores, gait velocity, regular exercise, the number of comorbidities, and depression, while CF improvement was significantly associated with female sex, balance scores, and the number of comorbidities. CONCLUSIONS: The baseline CF state, an older age, poorer balance, slower gait, and a high number of comorbidities may contribute to CF progression, while the baseline CF state may account for associations of engaging in regular exercise and depression with CF development.

Astragalus polysaccharide promotes autophagy and alleviates diabetic nephropathy by targeting the lncRNA Gm41268/PRLR pathway.

BACKGROUND: Astragalus polysaccharide (APS) is a major bioactive component of the Chinese herb astragalus, with well-established protective effects on the kidney. However, the effect of APS on diabetic nephropathy (DN) is unclear. METHODS: Long non-coding RNA (lncRNA) expression profiles in kidney samples from control, db/db, and APS-treated db/db mice were evaluated using RNA high-throughput sequencing techniques. Additionally, rat renal tubular epithelial (NRK-52E) cells were cultured in high glucose (HG) media. We inhibited the expression of Gm41268 and prolactin receptor (PRLR) by transfecting NRK-52E cells with Gm41268-targeting antisense oligonucleotides and PRLR siRNA. RESULTS: We found that APS treatment reduced 24-h urinary protein levels and fasting blood glucose and improved glucose intolerance and pathological renal damage in db/db mice. Furthermore, APS treatment enhanced autophagy and alleviated fibrosis in the db/db mice. We identified a novel lncRNA, Gm41268, which was differentially expressed in the three groups, and the cis-regulatory target gene PRLR. APS treatment induced autophagy by reducing p62 and p-mammalian target of rapamycin (mTOR) protein levels and increasing the LC3 II/I ratio. Furthermore, APS alleviated fibrosis by downregulating fibronectin (FN), transforming growth factor-ß (TGF-ß), and collagen IV levels. In addition, APS reversed the HG-induced overexpression of Gm41268 and PRLR. Reduction of Gm41268 decreased PRLR expression, restored autophagy, and ameliorated renal fibrosis in vitro. Inhibition of PRLR could enhance the protective effect of APS. CONCLUSIONS: In summary, we demonstrated that the therapeutic effect of APS on DN is mediated via the Gm41268/PRLR pathway. This information contributes to the exploration of bioactive constituents in Chinese herbs as potential treatments for DN.

Highly efficient decomplexation of chelated nickel and copper effluent through CuO-CeO2-Co3O4 nanocatalyst loaded on ceramic membrane.

A novel CuO-CeO2-Co3O4 nanocatalyst loaded on Al2O3 ceramic composite membrane (CCM-S) was synthesized through spraying-calcination method, which can be beneficial to the engineering application of scattered granular catalyst. BET and FESEM-EDX testing revealed that CCM-S possessed a porous character with high BET surface area of 22.4 m2/g and flat modified surface with extremely fine particle aggregation. The CCM-S calcined above 500 °C presented excellent anti-dissolution effect due to the formation of crystals. XPS indicated that the composite nanocatalyst possessed the variable valence states, which were conducive to exert the catalytic effect of Fenton-like reaction. Subsequently, the effects of experimental parameters including fabricate method, calcination temperature, H2O2 dosage, initial pH value, and CCM-S amount were further investigated considering the removal efficiency of Ni(II)-complex and COD after decomplexation and precipitation (pH = 10.5) treatment within 90 min. Under the optimal reaction condition, the residual Ni(II)-complex and Cu(II)-complex concentration from actual wastewater was all lower than 0.18 mg/L and 0.27 mg/L, respectively; meanwhile, the removal efficiency of COD was all higher than 50% in the mixed electroless plating effluent. Besides, the CCM-S could still maintain high catalytic activity after a six-cycle test, and the removal efficiency was slightly declined from 99.82% to 88.11%. These outcomes indicated that CCM-S/H2O2 system was provided with a potential applicability on treatment of real chelated metal wastewater.

Inhibition of ferroptosis ameliorates hypertensive nephropathy through p53/Nrf2/p21 pathway by Taohongsiwu decoction: Based on network pharmacology and experimental validation.

ETHNOPHARMACOLOGICAL RELEVANCE: Hypertensive nephropathy (HN) is a complication of hypertension. Taohongsiwu decoction (THSWD) is used clinically but its application in the prevention and treatment of HN remains unelucidated. AIM OF STUDY: This study aims to explore the potential targets and molecular mechanisms of THSWD in the treatment of HN. MATERIALS AND METHODS: A network pharmacology approach was used to predict the components and targets of THSWD for treating HN. Animal experiments were performed to verify the network pharmacology findings. RESULTS: 205 targets were identified and regarded as potential targets of THSWD in HN treatment. Subsequently, we screened 17 hub genes and identified TP53 as the most critical one. KEGG enrichment analysis showed that p53 signaling pathway might play a significant role. In vivo experiments indicated that high-salt diets can lead to high blood pressure, kidney injury, inflammation, and fibrosis. Furthermore, the altered levels of biomarkers (Iron, malondialdehyde, catalase, ferritin, transferrin, Superoxide dismutase and Glutathione Peroxidase 4) provided evidence of ferroptosis. We found that the ferroptosis inhibitor ferrostatin-1 (Fer-1) and THSWD could significantly alleviate HN by suppressing ferroptosis. THSWD and Fer-1 treatment downregulated the protein and mRNA expression of p53, p21, RB, and CTNNB1, which were upregulated by high salt. Meanwhile, THSWD and Fer-1 reversed the downregulation of Nrf2 caused by high-salt diet. CONCLUSIONS: Our results suggested that THSWD attenuate HN induced by a high-salt diet through inhibiting ferroptosis via the p53/Nrf2/p21 pathway.

Ocular Trauma During COVID-19 Pandemic: A Systematic Review and Meta-analysis.

PURPOSE: This study aimed to summarize the latest literature on the trends and incidence of ocular trauma during the COVID-19 pandemic. DESIGN: Systematic review and meta-analysis. METHODS: A systematic literature search was conducted to identify the relevant literature. The search period was between January 1, 2020, and September 20, 2021. The incidence of overall and various types of ocular trauma during the COVID-19 pandemic and the control period was analyzed. The data from different studies were pooled. The odds ratio (OR) and 95% confidence interval (CI) were calculated. RESULTS: A total of 32 articles were included. After pooling the data from all included studies, the incidence of total and pediatric ocular trauma during the COVID-19 pandemic was 67.7% and 54.3% of those in the control period, respectively. However, the proportion of ocular trauma in eye emergency visits increased during the pandemic (OR, 95% CI: 1.46, 1.04-2.06). The proportion of domestic ocular trauma increased (OR, 95% CI: 3.42, 1.01-11.62), while ocular trauma related to sports and outdoor activities and occupational ocular trauma decreased (OR, 95% CI: 0.64, 0.09-4.29 and 0.18, 0.10-0.33, respectively). It was also reported that chemical injury caused by alcohol-based sanitizers, photokeratitis caused by ultraviolet lamps, and mechanical eye injury caused by masks increased during the COVID-19 pandemic. CONCLUSIONS: There was a reduction in overall eye injuries and substantial differences in the spectrum of ocular trauma during the COVID-19 pandemic. Proper health education and supervision should be strengthened to prevent ocular injuries related to COVID-19 preventive interventions.

Determinants of the health care service choices of long-term mechanical ventilation patients: Applying andersen's behavioral model.

AIMS: The number of ventilator-dependent patients is rapidly increasing globally. As a result, long-term mechanical ventilation (LTMV) patients face the choice of receiving health care in respiratory care wards (RCWs) rather than at home. In this study, we applied Andersen's behavioral theoretical model (ABM) to investigate the determinants of the health care service decisions of patients receiving LTMV. METHODS: A cross-sectional research design and cluster random sampling were used to select 365 participants from nine RCWs and eight home care facilities in northern Taiwan. Data were collected in face-to-face interviews using a structured questionnaire. RESULTS: Of the predisposing factors, advanced age and an education level of at least junior high school influenced the choice to use RCW services. Being married, living with extended family, and medium or higher socioeconomic status were associated with the decision to use home care services. Of the enabling factors, patients with more caregivers, those whose family caregivers held strong beliefs about providing care, and those who perceived greater social support from health care providers were more likely to choose home care services. Of the need factors examined, poor cognitive function and higher dependence on assistance for activities of daily living (ADL) increased the probability of patients choosing RCW services. Hierarchical logistic regression analysis indicated that our final model accounted for 44.8% of the observed variance in health care service choice. CONCLUSIONS: ABM enables an improved understanding of the health care service choices of LTMV patients. Our findings also highlight the importance of rigorously assessing patient needs and helping patients choose the most appropriate health care service.

Micro and nano bubbles promoted biofilm formation with strengthen of COD and TN removal synchronously in a blackened and odorous water.

Blackening and odorization of rivers (BOR) distributed widely in urban cities with high density of human beings. Amounts of pollution control methods have been developed for treatment of these contaminated rivers. Among them, artificial aeration is an effective method for BOR treatment. As a novel developed aeration approach, Micro and nano bubbles (MNBs) takes advances of high specific surface area, high oxygen transfer, long retain time and interface effect. Thus, MNBs aeration was used in an anoxic-oxic (AO) process with traditional activated sludge methods to treat water of BOR in this study. A special designed reactor was made to allow both MNBs and macro bubbles aeration of which mode could be altered easily. The results revealed that MNBs improved removal of COD, NH4+-N and TN distinctly in water of BOR. MNBs provided high dissolved oxygen and promoted the transformation from floc sludge to biofilm. Significant difference between the microbial community of MNBs and macro bubbles sludges was revealed by 16S rRNA amplicon sequencing. Function predictions of MNBs and macro bubbles sludges indicated MNBs enhanced nitrification and aerobic ammonia oxidation without negative impact on denitrification. Moreover, biofilm formed bacteria were enriched by MNBs aeration. This study demonstrated MNBs would be a great potential for the combination of activated sludge and biofilm to treat BOR.

Decomplexation removal of Ni(II)-citrate complexes through heterogeneous Fenton-like process using novel CuO-CeO2-CoOx composite nanocatalyst.

A novel CuO-CeO2-CoOx nanocatalyst was prepared for heterogeneous Fenton-like reaction to break the Ni2+-chelate into free Ni2+ in electroless nickel plating wastewater, followed by separation of Ni2+ in an insoluble form. The composite nanocatalysts prepared by co-precipitation method were characterized by XRD, TEM, and XPS, et al. Its catalytic activity as Fenton-like reagent was evaluated by the removal efficiency of Ni(II)-citrate after decomplexation and postprecipitation treatment. Subsequently, the effects of operating parameters on the decomplexation efficiency of the nanocatalysts were investigated including calcination temperature of catalysts, H2O2 concentration, catalyst dosage, initial pH and reaction temperature. Under optimized condition, the Ni(II)-citrate complexes (C0 = 1.0 mM) achieved the complete decomplexation (>99.9%) within 60-min reaction using 0.3 g/L of CuO-CeO2-CoOx calcined at 450 °C and 75 mM of H2O2 at pH 3.0 under 50 °C of reaction. Then, Ni2+ after decomplexation could be completely removed by the subsequent precipitation at pH 11.0. In addition, the life test of CuO-CeO2-CoOx catalyst indicated that, after recycled 10 times, its activity for decomplexation of Ni(II)-citrate decreased no more than 8%. As a result, this new heterogeneous Fenton-like process is promising for decomplexation and purification of electroless nickel plating wastewater as a sludge reduction technology.

Enhanced photoelectrocatalytic degradation of bisphenol A and simultaneous production of hydrogen peroxide in saline wastewater treatment.

The degradation of organic pollutants in saline wastewater has been a challenge for environmental remediation. In this study, a two-chamber cell was structured to simultaneously degrade organic contaminants (bisphenol A, BPA) from saline wastewater and produce hydrogen peroxide (H2O2). In the anode chamber, a new solar-light-driven system was devised using chloride ions (Cl‾) as a medium and WO3 photoanode as a radical initiator. Under solar light irradiation, photogenerated holes yielded at the WO3 photoanode promoted the conversion of Cl‾ to reactive chlorine species, which could oxidize BPA more rapidly. The results indicated that the BPA removal can be significantly enhanced by increasing pH to 10.8 or increasing the Cl‾ concentration to 200 mM. At these conditions, 92% BPA was degraded into CO2 and H2O in 120 min. In the cathode chamber, a new dopamine modified carbon felt (CF-DPA) cathode was employed to produce H2O2, obtaining a high concentration of 5.4 mM under optimum conditions. The electrochemical analyses for CF-DPA revealed that dopamine modification promoted electron transfer and enhanced the two-electron oxygen reduction to increase H2O2 yields.

Application of a Q Method Study to Understanding Nurses' Perspective of Adopting Evidence-Based Nursing.

PURPOSE: This study applied the Q method to identify and describe the various types of nurse perceptions that are crucially associated with their engagement in evidence-based nursing (EBN). METHODS: The study participants were nurses at a medical center and a regional teaching hospital. A series of Q sorts was performed by nurses to subjectively rank the Q statements. Q statements were constructed based on the literature related to EBN adoption by nurses and face-to-face interviews. RESULTS: A total of 60 participants were invited to rank 44 Q statements related to EBN. Factor analysis was conducted on the rankings of the Q statements. The following are the five prominent shared perspectives: (1) emphasized the obstacles to evidence searching and reading ability; (2) emphasized the organizational promotive strategies; (3) emphasized the available supportive resources; (4) emphasized the significance of EBN; and (5) emphasized the evidence-searching ability and external incentives. The five identified groups of perspectives can enhance hospital administrators to acknowledge the barriers and incentives associated with EBN practices. CONCLUSION: The exploration of clustering nurses' perceptions may facilitate the development of customized strategies to enable more appropriate training.

Nurse characteristics, leadership, safety climate, emotional labour and intention to stay for nurses: a structural equation modelling approach.

AIM: The aim of this study was to propose a theoretical model and apply it to examine the structural relationships among nurse characteristics, leadership characteristics, safety climate, emotional labour and intention to stay for hospital nurses. BACKGROUND: Global nursing shortages negatively affect the quality of care. The shortages can be reduced by retaining nurses. Few studies have independently examined the relationships among leadership, safety climate, emotional labour and nurses' intention to stay; more comprehensive theoretical foundations for examining nurses' intention to stay and its related factors are lacking. DESIGN: Cross-sectional. METHODS: A purposive sample of 414 full-time nurses was recruited from two regional hospitals in Taiwan. A structured questionnaire was used to collect data from November 2013-June 2014. Structural equation modelling was employed to test the theoretical models of the relationships among the constructs. RESULTS: Our data supported the theoretical model. Intention to stay was positively correlated with age and the safety climate, whereas working hours per week and emotional labour were negatively correlated. The nursing position and transformational leadership indirectly affected intention to stay; this effect was mediated separately by emotional labour and the safety climate. CONCLUSION: Our data supported the model fit. Our findings provide practical implications for healthcare organizations and administrators to increase nurses' intent to stay. Strategies including a safer climate, appropriate working hours and lower emotional labour can directly increase nurses' intent to stay. Transformational leadership did not directly influence nurses' intention to stay; however, it reduced emotional labour, thereby increasing intention to stay.

Inhibition of BACE1 Activity by a DNA Aptamer in an Alzheimer's Disease Cell Model.

An initial step in amyloid-ß (Aß) production includes amyloid precursor protein (APP) cleavage via ß-Site amyloid precursor protein cleaving enzyme 1 (BACE1). Increased levels of brain Aß have been implicated in the pathogenesis of Alzheimer's disease (AD). Thus, ß-secretase represents a primary target for inhibitor drug development in AD. In this study, aptamers were obtained from combinatorial oligonucleotide libraries using a technology referred to as systematic evolution of ligands by exponential enrichment (SELEX). A purified human BACE1 extracellular domain was used as a target to conduct an in vitro selection process using SELEX. Two DNA aptamers were capable of binding to BACE1 with high affinity and good specificity, with Kd values in the nanomolar range. We subsequently confirmed that one aptamer, A1, exhibited a distinct inhibitory effect on BACE1 activity in an AD cell model. We detected the effects of M17-APPsw cells that stably expressed Swedish mutant APP after aptamer A1 treatment. Aß40 and Aß42 concentrations secreted by M17-APPsw cells decreased intracellularly and in culture media. Furthermore, Western blot analysis indicated that sAPPß expression significantly decreased in the A1 treated versus control groups. These findings support the preliminary feasibility of an aptamer evolved from a SELEX strategy to function as a potential BACE1 inhibitor. To our knowledge, this is the first study to acquire a DNA aptamer that exhibited binding specificity to BACE1 and inhibited its activity.

A U87-EGFRvIII cell-specific aptamer mediates small interfering RNA delivery.

U87-EGFRvIII is a U87 glioma cell line that overexpresses epidermal growth factor receptor variant III (EGFRvIII). In the present study, we investigated whether a DNA aptamer selected against U87-EGFRvIII using cell-based systematic evolution of ligands by exponential enrichment (cell-SELEX) could deliver c-Met small interfering RNA (siRNA) into U87-EGFRvIII cells and silence the targeted gene expression. The selected biotinylated aptamer (BA) was coupled to biotinylated c-Met siRNA by streptavidin to deliver siRNA into U87-EGFRvIII cells. c-Met siRNA, transfected with lipofectamine 2000, served as a positive control, while control siRNA, transferred with BA, served as a negative control. Western blotting was performed to detect changes in the c-Met protein expression, and MTT and Annexin V-fluorescein isothiocyanate/propidium iodine assays were used to determine changes in the proliferation and apoptosis of U87-EGFRvIII cells, respectively. Similar to the liposome-mediated group, U87-EGFRvIII cells that were transfected with BA-c-Met siRNA experienced a significant decrease in the c-Met protein expression (P<0.05). There were also significant increases in the apoptotic rate (P<0.05) and inhibition rate of cell growth (P<0.01) compared with the negative control group, indicating that BA could deliver c-Met siRNA into U87-EGFRvIII and result in target gene silencing. In conclusion, the results demonstrated that this DNA aptamer, obtained through cell-SELEX, can be used as an efficient and targeted carrier for siRNA delivery, providing a novel approach and strategy for the targeted combination therapy of glioblastoma.

Cell-SELEX aptamer for highly specific radionuclide molecular imaging of glioblastoma in vivo.

Glioblastoma (GBM) is the most frequent and aggressive primary adult brain tumor with poor prognosis. Epidermal growth factor receptor variant III (EGFRvIII) is the most common and highly oncogenic EGFR mutant in GBM. With the aim to generate specific molecular probes able to target EGFRvIII with high affinity, we selected four DNA aptamers (U2, U8, U19 and U31) specifically bound to U87-EGFRvIII cells that over expressed EGFRvIII with Kd values in the nanomole range by a cell-based systematic evolution of ligands by exponential enrichment (cell-SELEX) process. U87MG cells were introduced as control cells for counter selection. We further affirmed U2 and U8 identified EGFRvIII on the surface of target cells specifically. Then we radiolabeled U2 with 188Re to serve as a molecular imaging probe and observed 188Re -labeled U2 significantly targeted EGFRvIII over-expressing glioblastoma exnografts in mice. In conclusion, aptamers obtained from whole cell-SELEX strategy have great potential as molecular imaging probes that are probably beneficial to GBM diagnoses.

DNA aptamers that target human glioblastoma multiforme cells overexpressing epidermal growth factor receptor variant III in vitro.

AIM: Aptamers are oligonucleic acid or peptide molecules that bind to a specific target molecule in cells, thus may act as effective vehicles for drug or siRNA delivery. In this study we investigated the DNA aptamers that target human glioblastoma multiforme (GBM) cells overexpressing epidermal growth factor receptor variant III (EGFRvIII), which was linked to radiation and chemotherapeutic resistance of this most aggressive brain tumor. METHODS: A 73-mer ssDNA library containing molecules with 30 nt of random sequence flanked by two primer hybridization sites was chosen as the initial library. Cell systematic evolution of ligands by exponential enrichment (Cell-SELEX) method was used to select the DNA aptamers that target EGFRvIII. The binding affinity of the aptamers was measured using a cell-based biotin-avidin ELISA. RESULTS: After 14 rounds of selection, four DNA aptamers (32, 41, 43, and 47) that specifically bound to the EGFRvIII-overexpressing human glioma U87Δ cells with Kd values of less than 100 nmol/L were discovered. These aptamers were able to distinguish the U87Δ cells from the negative control human glioma U87MG cells and HEK293 cells. Aptamer 32 specifically bound to the EGFRvIII protein with an affinity similar to the EGFR antibody (Kd values of aptamer 32 and the EGFR antibody were 0.62±0.04 and 0.32±0.01 nmol/L, respectively), and this aptamer was localized in the cell nucleus. CONCLUSION: The DNA aptamers are promising molecular probes for the diagnosis and treatment of GBM.

[Cell-ELA-based determination of binding affinity of DNA aptamer against U87-EGFRvIII cell].

A15, a DNA aptamer with binding specificity for U87 glioma cells stably overexpressing the epidermal growth factor receptor variant III (U87-EGFRvIII), was generated by cell systematic evolution of ligands by exponential enrichment (cell-SELEX) using a random nucleotide library. Subsequently, we established a cell enzyme-linked assay (cell-ELA) to detect the affinity of A15 compared to an EGFR antibody. We used A15 as a detection probe and cultured U87-EGFRvIII cells as targets. Our data indicate that the equilibrium dissociation constants (K(d)) for A15 were below 100 nmol/L and had similar affinity compared to an EGFR antibody for U87-EGFRvIII. We demonstrated that the cell-ELA was a useful method to determine the equilibrium dissociation constants (K(d)) of aptamers generated by cell-SELEX.