Removal of ammonium and heavy metals by cost-effective zeolite synthesized from waste quartz sand and calcium fluoride sludge.

This study focuses on the effectiveness of zeolite (10% CF-Z [0.5]) hydrothermally synthesized from waste quartz sand and calcium fluoride (CF) for ammonium ion and heavy metal removal. Zeolite was characterized through powder X-ray diffraction, Fourier-transform infrared spectroscopy, micromeritics N2 adsorption/desorption analysis, and field emission scanning electron microscopy. The effects of CF addition, Si/Al ratio, initial ammonium concentration, solution pH, and temperature on the adsorption of ammonium on 10% CF-Z (0.5) were further examined. Results showed that 10% CF-Z (0.5) was a single-phase zeolite A with cubic-shaped crystals and 10% CF-Z (0.5) efficiently adsorbs ammonium and heavy metals. For instance, 91% ammonium (10 mg L-1) and 93% lead (10 mg L-1) are removed. The adsorption isotherm, kinetics, and thermodynamics of ammonium adsorption on 10% CF-Z (0.5) were also theoretically analyzed. The adsorption isotherm of ammonium and lead on 10% CF-Z (0.5) in single systems indicated that Freundlich model provides the best fit for the equilibrium data, whereas pseudo-second-order model best describes the adsorption kinetics. The adsorption degree of ions on 10% CF-Z (0.5) in mixed systems exhibits the following pattern: lead > ammonium > cadmium > chromium.

Percutaneous device occlusion and minimally invasive surgical repair for perimembranous ventricular septal defect.

BACKGROUND: Percutaneous device occlusion and minimally invasive surgical repair for perimembranous ventricular septal defect (pmVSD) are two typical methods to reduce the invasiveness of the conventional operation through a median sternotomy. However, few studies have compared them in terms of effectiveness and cost. METHODS: Inpatients with isolated pmVSD who had undergone percutaneous device occlusion or minimally invasive surgical repair from June 2009 to June 2012 were reviewed for a comparative investigation between the two procedures. RESULTS: Procedure success was achieved in 80 percutaneous (93.0%) and in 113 surgical (98.3%) procedures (p=0.076). Percutaneous patients were older, with a smaller VSD size than surgical patients (16±11.7 vs 3.8±2.4 mm, p<0.001; 4.0±1.2 vs 4.3±1.3 mm, p=0.034, respectively). Major complications occurred in 1 percutaneous (1.2%) and in 4 surgical (3.5%) procedures (p=0.602), and minor complications occurred in 27 percutaneous (33.3%) and in 37 surgical (32.2%) procedures (p=0.991). The surgical repair cost 31% less than the device occlusion (¥20,565±¥3,497 vs ¥29,795±¥2,643, p<0.001), where most of the cost was attributed to the occluder in the amount of ¥19,500. CONCLUSIONS: Compared with device occlusion, minimally invasive surgical repair can provide comparable efficacy and complication rates. In addition, it is 31% cheaper than device occlusion. In low-income countries where health care resources are limited, medical resources must be judiciously allocated to the treatment that allows for effective treatment of the largest number of patients.

Women on hemodialysis have lower self-reported health-related quality of life scores but better survival than men.

BACKGROUND: Hemodialysis patients suffer from poor quality of life and survival. A retrospective cohort study was performed to examine the sex differences in self-reported quality of life and mortality in a Taiwanese hemodialysis cohort. METHODS: A total of 816 stable hemodialysis patients were included. Patients completed two questionnaires: the 36-item Short Form Health Survey Questionnaire (SF-36, Taiwan Standard Version 1.0) to assess health-related quality of life (HRQoL) and the Beck Depression Inventory (BDI, Chinese Version) to assess depressive mood. Mortality outcomes were recorded for a seven-year follow-up period. RESULTS: After adjustment for confounding factors, women had significantly higher BDI scores (P=.003), lower physical functioning (P<.001), bodily pain (P<.001), mental health (P=0007), and physical component scale (PCS) scores (P<.001). There were 284 deaths recorded. In the Cox-proportional hazard model, women had significantly lower mortality than men (P<.001). CONCLUSIONS: Women on hemodialysis had more depression-related symptoms and poor self-reported HRQoL, but better survival than men. The sex difference in psychological and HRQoL issues deserves greater concern because this relates to clinical care and further study.

[Stability of penicillin potassium with linear degradation programmed humidifying experiments].

A linear degradation humidifying model for drug stability experiment is introduced. This new humidifying model is presented as: H(r) = -M1-ln {exp(- MH(r,0)) - [exp(-MH(r,0)) -exp(-MH(r-m)) t(m)-t}. Where H(r) is the relative humidity; t is the time; H(r,m) and t(m) are the final relative humidity and time of the experiment, respectively. M is humidifying constant used in the humidifying program. In the new programmed humidifying model, a linear relationship between the content function of drugs and the relative humidity is obtained, the degradation of drugs can be more uniform within different humidity ranges and the experimental results are more accurate than those in the reported linear humidifying model. The stability of penicillin potassium, as a solid state model, was investigated by the linear degradation programmed humidifying and the exponential heating experiments. The results indicated that the kinetic parameters obtained by the linear degradation programmed humidifying and the exponential heating models were significantly more precise than those obtained by the linear programmed humidifying and the reciprocal heating models.