Resin-Mediated pH Control of Metal-Loaded Ligand Exchangers for Selective Nitrogen Recovery from Wastewaters.

Highly selective separation materials that recover total ammonia nitrogen (i.e., ammonia plus ammonium, or TAN) from wastewaters as a pure product can supplement energy-intensive ammonia production and incentivize pollution mitigation. We recently demonstrated that commercial acrylate cation exchange polymer resins loaded with transition metal cations, or metal-loaded ligand exchangers, can recover TAN from wastewater with high selectivity (TAN/K+ equilibrium selectivity of 10.1) via metal-ammine bond formation. However, the TAN adsorption efficiency required further improvement (35%), and the optimal concentration and pH ranges were limited by both low ammonia fractions and an insufficiently strong resin carboxylate-metal bond that caused metal elution. To overcome these deficiencies, we used a zinc-acrylate ligand exchange resin and a tertiary amine acrylic weak base resin (pH buffer resin) together to achieve resin-mediated pH control for optimal adsorption conditions. The high buffer capacity around pH 9 facilitated gains in the adsorbed TAN per ligand resin mass that enhanced the TAN adsorption efficiency to greater than 90%, and constrained zinc elution (below 0.01% up to 1 M TAN) because of decreased ammonia competition for zinc-carboxylate bonds. During TAN recovery, resin-mediated pH buffering facilitated recovery of greater than 99% of adsorbed TAN with 0.2% zinc elution, holding the pH low enough to favor ammonium but high enough to prevent carboxylate protonation. For selective ion separation, solid phase buffers outperform aqueous buffers because the initial solution pH, the buffering capacity, and the ion purity can be independently controlled. Finally, because preserving the resin-zinc bond is crucial to sustained ligand exchange performance, the properties of an ideal ligand resin functional group were investigated to improve the properties beyond those of carboxylate. Ultimately, ligand exchange adsorbents combined with solid pH buffers can advance the selective recovery of nitrogen and potentially other solutes from wastewaters.

Selective Recovery of Ammonia Nitrogen from Wastewaters with Transition Metal-Loaded Polymeric Cation Exchange Adsorbents.

Extracting valuable products from wastewaters with nitrogen-selective adsorbents can offset energy-intensive ammonia production, rebalance the nitrogen cycle, and incentivize environmental remediation. Separating nitrogen (N) as ammonium from other wastewater cations (e.g., K+ , Ca2+ ) presents a major challenge to N removal from wastewater and N recovery as high-purity products. High selectivity and capacity were achieved through ligand exchange of ammonia with ammine-complexing transition metals loaded onto polymeric cation exchange resins. Compared to commercial resins, metal-ligand exchange adsorbents exhibited higher ammonia removal capacity (8 mequiv g-1 ) and selectivity (N/K+ equilibrium selectivity of 10.1) in binary equimolar solutions. Considering optimal ammonia concentrations (200-300 mequiv L-1 ) and pH (9-10) for metal-ligand exchange, hydrolyzed urine was identified as a promising candidate for selective TAN recovery. However, divalent cation exchange increased transition metal elution and reduced ammonia adsorption. Ultimately, metal-ligand exchange adsorbents can advance nitrogen-selective separations from wastewaters.

Characterization of Differences Between Prostate Cancer Patients Presenting With De Novo Versus Primary Progressive Metastatic Disease.

BACKGROUND: Men who present with metastatic disease can have de novo or primary progressive disease. We characterized and compared the outcomes between these 2 groups. PATIENTS AND METHODS: A retrospective cross-sectional analysis from a single institution of de novo versus primary progressive metastatic patients during a 2-year consecutive period was undertaken. Patient characteristics such as demographics, Gleason score, duration of hormone sensitivity, and treatment were obtained. The t test, Mann-Whitney U test, and Fisher exact test were used to test differences in patient and disease characteristics between the de novo and primary progressive metastatic groups. Differences in the Kaplan-Meier survival curves were compared using the log-rank test. RESULTS: A total of 90 patients (n = 38 with de novo and 52 with primary progressive disease) were included. Statistically significant median differences were found for the prostate-specific antigen level at the development of metastases: de novo 63.1 ng/ml vs primary progressive 12.5 ng/ml, p= <.001; albumin and hemoglobin, P = .03 and P = .045, respectively). The median duration of hormone sensitivity was 372 days (range, 54-3753 days) in the de novo group versus 1613 days (range, 7-4314 days) in the primary progressive group (P = .00006). Overall survival was worse in the de novo arm, with a median survival of 6.2 years compared with a median survival in the primary progressive group of 11.6 years (P = .027). CONCLUSION: Although the reported samples were small, our data revealed a potential difference in disease aggressiveness in those presenting with de novo metastatic cancer with higher risk disease and shorter time to castration resistance and worse survival. These data could have implications for earlier and more aggressive treatment for men presenting with de novo metastatic prostate cancer.

Phase 2 clinical trial of sunitinib as adjunctive treatment in patients with advanced differentiated thyroid cancer.

OBJECTIVE: Our objective was to evaluate the efficacy and safety of sunitinib following at least one course of radioactive iodine treatment in patients with advanced differentiated thyroid cancer (DTC). The study endpoints included best response rate (including best objective response rate) and progression-free survival (PFS) per Response Evaluation Criteria in Solid Tumors (RECIST) 1.1, measurement of serum thyroglobulin (Tg), and toxicity evaluation. DESIGN AND METHODS: This was a single center, nonrandomized, open-label, phase 2 clinical trial. In total, 23 patients were enrolled and were treated with a starting daily, oral dose of 37.5  mg sunitinib. Patients were evaluated with imaging, laboratory tests, and physical examination periodically per protocol. RESULTS: The mean best response was a decrease of 17.2% (S.D. 22.8) in tumor sum from baseline. Six (26%) patients achieved a partial response (PR), and 13 (57%) had stable disease (SD) for a clinical benefit rate (PR+SD) of 83%. The overall median PFS was 241 days (interquartile limits, 114-518). No statistically significant difference was observed between the medians of the baseline and post-treatment Tg values (P=0.24). The most common adverse events included grades 1 and 2 decreases in blood cell counts (especially leukocytes), diarrhea, fatigue, hand-foot skin reaction, nausea, musculoskeletal pain, and hypertension. CONCLUSIONS: These data demonstrate that sunitinib exhibits significant anti-tumor activity in patients with advanced DTC. Since sunitinib was relatively well-tolerated, there is the potential for clinical benefit in these patients, and further investigation of this agent is warranted.

Evaluation of bioremediation methods for the treatment of soil contaminated with explosives in Louisiana Army Ammunition Plant, Minden, Louisiana.

Two bioremediation methods, namely, soil slurry reactor and land farming technique were evaluated for the treatment of soil contaminated with explosives in Louisiana Army Ammunition Plant, Minden, Louisiana. The soil had a high concentration of 2,4,6-trinitrotoluene (TNT) of 10,000 mg/kg of soil and medium level contamination of RDX 1900 mg/kg and HMX 900 mg/kg of soil. The results indicated that soil slurry reactor under co-metabolic condition with molasses as co-substrate removed TNT more efficiently than land farming method. TNT removal efficiency was 99% in soil slurry reactor compared to 82% in land farming after 182 days. HMX and RDX were also removed from the soil in both methods, but the removal efficiency was low. The radiolabeled study showed that soil microbes mineralize TNT. The mass-balance of TNT indicated 23.5% of TNT was mineralized to CO(2), 22.6% was converted to biomass, and 52.3% was converted to various TNT intermediates in the soil slurry reactor. Both methods maintained high bacterial population fairly well. The results of this bench-scale study are promising with regard to transferring the technology to full-scale application at this site.

Comparisons between twice-daily and once-daily training sessions in male weight lifters.

CONTEXT: Many elite athletes use increased daily training frequencies as a means to increase training load without substantial published literature to support this practice. PURPOSE: To compare the physiological responses to twice- and once-daily training sessions with similar training volumes. METHODS: Ten nationally competitive male weightlifters (age 20.5 +/- 1.2 y, body mass 92.9 +/- 23.6 kg, training history 5.5 +/- 1.5 y) were matched on body mass and training experience, then randomly assigned to train either once or twice daily for 3 wk. Isometric knee-extension strength (ISO), muscle cross-sectional area, vertical-jump peak power, resting hormone concentrations, neuromuscular activation (EMG), and weightlifting performance were obtained before and after the experimental training period. RESULTS: All dependent measures before the training intervention were similar for both groups. A 2-way repeated-measures ANOVA did not reveal any significant main effects (group or trial) or interaction effects (group x trial) for any of the dependent variables. There were also no significant group differences when parameters were expressed as percentage change, but the twice-daily training group had a greater percentage change in ISO (+5.1% vs +3.2%), EMG (+20.3% vs +9.1%), testosterone (+10.5% vs +6.4%), and testosterone:cortisol ratio (-10.5% vs +1.3%) than did the once-daily training group. CONCLUSIONS: There were no additional benefits from increased daily training frequency in national-level male weightlifters, but the increase in ISO and EMG activity for the twice-daily group might provide some rationale for dividing training load in an attempt to reduce the risk of overtraining.