Tetracycline removal from aqueous solution by biochar derived from algae and modified with MnMoO4: effects of operating parameters, isotherm, kinetic, and thermodynamic study

The aim of the present study is to improve the adsorption of tetracycline (TC) onto biochar of microalgae modified by nanocomposite of MnMoO₄ (MM40BC60). The synthesized nanocomposite was characterized by Scanning electron microscopy (SEM), Brunauer-Emmett-Teller (BET) surface area, Fourier transforms infrared (FTIR) spectroscopy to investigate the morphology, surface area, pores and the functional groups of MM40BC60, respectively. The effect of various parameters including initial pH, TC concentration, and temperature on the adsorption performance of TC to the adsorbent was evaluated with considering kinetics, isotherms, and thermodynamics models. The adsorption of TC on MM40BC60 shows good agreement with the pseudo-second-order kinetic and the Langmuir isotherm models. Results of the thermodynamic study showed that the adsorption process was a spontaneous and endothermic reaction in nature.

Fuzzy AHP approach for prioritizing electronic waste management options: a case study of Tehran, Iran

Electronic waste (E-waste) can be considered as challenging solid waste streams especially in some developing countries, including Iran. Several alternatives for collecting and processing E-waste have been developed and applied throughout the world. In this research, a model was developed according to fuzzy-AHP approach for the evaluation of different alternatives for E-waste's collection and processing in Tehran, Iran. Three alternatives for processing section (including recycling, exporting, landfilling) and three alternatives for collection section (door-to-door, special event, permanent drop-off) were studied in terms of different economic, social, technical, and environmental criteria. To establish a database in the current research, a questionnaire survey was performed and then the relative importance of each alternative in terms of each criterion was evaluated. The obtained results indicated that in the section of collection and processing of E-waste, permanent drop-off and recycling have the highest priorities among studied alternatives, respectively. Also, economic and environmental criteria were determined as the most significant ones in collection and processing sections, respectively. Furthermore, the developed model can be considered as a practical tool that will help the decision makers to determine the most appropriate E-waste management alternatives when diverse criteria are partially or completely in conflict.

Performance evaluation and modeling of a submerged membrane bioreactor treating combined municipal and industrial wastewater using radial basis function artificial neural networks

Treatment process models are efficient tools to assure proper operation and better control of wastewater treatment systems. The current research was an effort to evaluate performance of a submerged membrane bioreactor (SMBR) treating combined municipal and industrial wastewater and to simulate effluent quality parameters of the SMBR using a radial basis function artificial neural network (RBFANN). The results showed that the treatment efficiencies increase and hydraulic retention time (HRT) decreases for combined wastewater compared with municipal and industrial wastewaters. The BOD, COD, [Formula: see text] and total phosphorous (TP) removal efficiencies for combined wastewater at HRT of 7 hours were 96.9%, 96%, 96.7% and 92%, respectively. As desirable criteria for treating wastewater, the TBOD/TP ratio increased, the BOD and COD concentrations decreased to 700 and 1000 mg/L, respectively and the BOD/COD ratio was about 0.5 for combined wastewater. The training procedures of the RBFANN models were successful for all predicted components. The train and test models showed an almost perfect match between the experimental and predicted values of effluent BOD, COD, [Formula: see text] and TP. The coefficient of determination (R(2)) values were higher than 0.98 and root mean squared error (RMSE) values did not exceed 7% for train and test models.

All-oral, interferon-free treatment for chronic hepatitis C: cost-effectiveness analyses

Interferon-based standard of care treatments (SOC) for chronic hepatitis C are unable to provide high cure rates in certain subgroups of the infected population and can cause debilitating side effects. Clinical trials evaluating all-oral, interferon-free treatments have demonstrated high rates of sustained virologic response with no resistance or major adverse events in most populations. As these drug regimens move towards FDA approval, it will be important to assess their cost-effectiveness in addition to their clinical efficacy. A decision-analytic Markov model with a lifetime, societal perspective was used to evaluate the cost-effectiveness of a generalized all-oral drug regimen compared to SOC by modelling the progression of a 50-year-old, HCV-positive cohort through disease natural history and treatment. In base case analysis, all-oral treatment dominated SOC across a range of willingness-to-pay (WTP) thresholds with an incremental cost-effectiveness ratio (ICER) of US$44,514/quality-adjusted life year (QALY). In sensitivity analyses, the model was sensitive to all-oral drug costs as well as rates of SVR and treatment uptake among noncirrhotic subjects, but robust to variations in all other parameters. All-oral treatment was most cost-effective among genotype 1 subjects but remained cost-effective for genotypes 2 and 3 at WTP thresholds ≥$80,000/QALY. Quality-adjusted life years gained per dollar spent were maximized in younger treatment cohorts. Using this model, the degree of cost-effectiveness depended on the WTP threshold and the final cost set for approved drug combinations.

p53 expression and tumor proliferative activity in testicular germ-cell tumors

We evaluated p53 expression and tumor proliferative activity (TPA) using monoclonal antibodies to Ki-67 and proliferating cell nuclear antigen (PCNA) in 26 patients with seminomatous and nonseminomatous testicular germ-cell tumors (GCTs). Correlation between p53 expression and TPA, as well as the clinical correlation with the expression of these proteins were also assessed. There were eight cases of pure seminoma and 18 cases of nonseminomatous GCTs, collectively consisting of 45 tumors or tumor components. The nonseminomatous GCTs were mixed or pure and included choriocarcinoma (CC), embryonal carcinoma (EC), immature teratoma (IMT), mature teratoma (MT), seminoma, and yolk sac tumor (YST). The ages of the patients with seminomatous GCTs ranged from 24 to 47 years (mean, 34 years) and those for patients with nonseminomatous GCTs ranged from 17 to 43 years (mean, 29 years). Sixteen (44%) of the 36 nonseminomatous GCTs or tumor components were positive for p53 protein. Ten (91%) of eleven ECs, three (38%) of eight YSTs, two (20%) of ten MTs, and the single case of CC were positive for p53 protein. All nine seminomas and three of six IMTs were only focally positive for p53 protein. The p53 expression in ECs and YSTs was significantly higher than that in IMTs, MTs, and seminomas (P=0.0001). TPA was present in the majority of the seminomatous and nonseminomatous GCTs, and was significantly higher in ECs and YSTs than in seminomas, MTs, and IMTs (Ki-67, P=0.0001; PCNA, P=0.0006). In the majority of the cases PCNA expression was higher than Ki-67 expression (P=0.0001). The mean TPA percentage was significantly higher in the p53-positive tumors or tumor components (EC and YST) when compared with the mean TPA percentage in those neoplasms that were focally positive or negative for p53 protein (Ki-67, P=0.003; PCNA, P=0.046). p53 expression was also associated with histologically aggressive tumors (ECs and YSTs) that also exhibit high TPA. No relationship appears to exist between the three tumor markers and the clinical stage or the patients' follow-up and outcome in this small series. Further studies are necessary to elucidate the roles of p53 and proliferation markers in testicular tumorigenesis and as prognostic markers.

Ovulation following unilateral ovariectomy in the California leaf-nosed bat (Macrotus californicus)

Ovulation occurred from the left ovary in all 5 bats that had had the right ovary removed and an implanting blastocyst was found in the left uterine horn in 2 of these bats. All ovulations in the control and sham-operated bats occurred from the right ovary.