Characteristics and mechanisms of cadmium adsorption onto biogenic aragonite shells-derived biosorbent: Batch and column studies

© 2018 Elsevier Ltd Calcium carbonate (CaCO3)-enriched biomaterial derived from freshwater mussel shells (FMS) was used as a non-porous biosorbent to explore the characteristics and mechanisms of cadmium adsorption in aqueous solution. The adsorption mechanism was proposed by comparing the FMS properties before and after adsorption alongside various adsorption studies. The FMS biosorbent was characterized using nitrogen adsorption/desorption isotherm, X-ray diffraction, scanning electron microscopy with energy dispersive spectroscopy, Fourier-transform infrared spectroscopy, and point of zero charge. The results of batch experiments indicated that FMS possessed an excellent affinity to Cd(II) ions within solutions pH higher than 4.0. An increase in ionic strength resulted in a significant decrease in the amount of Cd(II) adsorbed onto FMS. Kinetic study demonstrated that the adsorption process quickly reached equilibrium at approximately 60 min. The FMS biosorbent exhibited the Langmuir maximum adsorption capacity as follows: 18.2 mg/g at 10 °C Cd2+ > Cu2+ > Cr3+ > Zn2+. For column experiments, the highest Thomas adsorption capacity (7.86 mg/g) was achieved at a flow rate (9 mL/min), initial Cd(II) concentration (10 mg/L), and bed height (5 cm). The Cd(II) removal by FMS was regarded as non-activated chemisorption that occurred very rapidly (even at a low temperature) with a low magnitude of activation energy. Primary adsorption mechanism was surface precipitation. Cadmium precipitated in the primary (Cd,Ca)CO3 form with a calcite-type structure on the FMS surface. A crust of rhombohedral crystals on the substrate was observed by SEM. Freshwater mussel shells have the potential as a renewable adsorbent to remove cadmium from water

Removing ammonium from water using modified corncob-biochar

© 2016 Elsevier B.V. Ammonium pollution in groundwater and surface water is of major concern in many parts of the world due to the danger it poses to the environment and people's health. This study focuses on the development of a low cost adsorbent, specifically a modified biochar prepared from corncob. Evaluated here is the efficiency of this new material for removing ammonium from synthetic water (ammonium concentration from 10 to 100 mg/L). The characteristics of the modified biochar were determined by Brunauer-Emmett-Teller (BET) test, Fourier transform infrared spectroscopy (FTIR) and Scanning electron microscopy (SEM). It was found that ammonium adsorption on modified biochar strongly depended on pH. Adsorption kinetics of NH4+-N using modified biochar followed the pseudo-second order kinetic model. Both Langmuir and Sips adsorption isotherm models could simulate well the adsorption behavior of ammonium on modificated biochar. The highest adsorption capacity of 22.6 mg NH4+-N/g modified biochar was obtained when the biochar was modified by soaking it in HNO3 6 M and NaOH 0.3 M for 8 h and 24 h, respectively. The high adsorption capacity of the modified biochar suggested that it is a promising adsorbent for NH4+-N remediation from water

Cystatin E/M suppresses legumain activity and invasion of human melanoma

<p>Abstract</p> <p>Background</p> <p>High activity of cysteine proteases such as legumain and the cathepsins have been shown to facilitate growth and invasion of a variety of tumor types. In breast cancer, several recent studies have indicated that loss of the cysteine protease inhibitor cystatin E/M leads to increased growth and metastasis. Although cystatin E/M is normally expressed in the skin, its role in cysteine protease regulation and progression of malignant melanoma has not been studied.</p> <p>Methods</p> <p>A panel of various non-melanoma and melanoma cell lines was used. Cystatin E/M and C were analyzed in cell media by immunoblotting and ELISA. Legumain, cathepsin B and L were analyzed in cell lysates by immunoblotting and their enzymatic activities were analyzed by peptide substrates. Two melanoma cell lines lacking detectable secretion of cystatin E/M were transfected with a cystatin E/M expression plasmid (pCST6), and migration and invasiveness were studied by a Matrigel invasion assay.</p> <p>Results</p> <p>Cystatin E/M was undetectable in media from all established melanoma cell lines examined, whereas strong immunobands were detected in two of five primary melanoma lines and in two of six lines derived from patients with metastatic disease. Among the four melanoma lines secreting cystatin E/M, the glycosylated form (17 kD) was predominant compared to the non-glycosylated form (14 kD). Legumain, cathepsin B and L were expressed and active in most of the cell lines, although at low levels in the melanomas expressing cystatin E/M. In the melanoma lines where cystatin E/M was secreted, cystatin C was generally absent or expressed at a very low level. When melanoma cells lacking secretion of cystatin E/M were transfected with pCST6, their intracellular legumain activity was significantly inhibited. In contrast, cathepsin B activity was not affected. Furthermore, invasion was suppressed in cystatin E/M over-expressing melanoma cell lines as measured by the transwell Matrigel assay.</p> <p>Conclusions</p> <p>These results suggest that the level of cystatin E/M regulates legumain activity and hence the invasive potential of human melanoma cells.</p

Surgical treatment of adolescent idiopathic scoliosis in the United States from 1997 to 2012: an analysis of 20, 346 patients

ObjectAdolescent idiopathic scoliosis (AIS) can cause substantial morbidity and may require surgical intervention. In this study, the authors aimed to evaluate US trends in operative AIS as well as patient comorbidities, operative approach, in-hospital complications, hospital length of stay (LOS), and hospital charges in the US for the period from 1997 to 2012.MethodsPatients with AIS (ICD-9-CM diagnosis codes 737.30) who had undergone spinal fusion (ICD-9-CM procedure codes 81.xx) from 1997 to 2012 were identified from the Kids' Inpatient Database. Parameters of interest included patient comorbidities, operative approach (posterior, anterior, or combined anteroposterior), in-hospital complications, hospital LOS, and hospital charges.ResultsThe authors identified 20, 346 patients in the age range of 0-21 years who had been admitted for AIS surgery in the defined study period. Posterior fusions composed 63.4% of procedures in 1997 and 94.1% in 2012 (r = 0.95, p ConclusionsOver the 15-year period considered in this study, there was an increasing trend toward using posterior-based techniques for AIS corrective surgery. The number of comorbid conditions per patient and thus the medical complexity of patients treated for AIS have increased. The mean charges for the treatment of AIS have increased, with a national bill over $1.1 billion per year in 2012

A Comparison of Perioperative Outcomes Between Single-port and Multiport Robot-assisted Laparoscopic Prostatectomy

Single-port (SP) robot-assisted laparoscopic prostatectomy (RALP) appears to be a safe and feasible approach for radical prostatectomy, but no prior studies have compared SP-RALP to a multiport (MP) platform. Using retrospective data from a single-center tertiary institution we compare 50 consecutive SP-RALP patients (da Vinci SP) to a contemporary cohort of 113 patients who underwent MP-RALP (da Vinci Xi). We found no significant differences in surgical or total operating room time. Pain scores were measured on a scale from 0 to 10. There were more pain-free patients on postoperative day 1 (18% difference, 95% confidence interval [CI] 9.9-27%) and there were shorter hospital stays (-1 d, 95% CI -1.0 to 0) in favor of SP. There were no significant differences in inpatient total morphine equivalents used, complication rates, or stress incontinence determined at a minimum of 90 d. These findings show that the learning curve for SP-RALP is relatively short for an experienced robotic surgeon and may favor better pain control and shorter hospitalization. PATIENT SUMMARY: We analyzed the differences in robotic surgery for localized prostate cancer using a single-port robotic platform compared to the traditional multiport robotic platform. We did not find significant differences in operative times, but significantly more patients were pain-free on the first postoperative day and had shorter hospital stays

Etiology of symptomatic urethritis in men and association with sexual behaviors

IntroductionGonorrhea and chlamydia are sexually transmitted infections (STI) that are the most common causes of urethritis in men. The role of specific sexual behaviors and presentation of urethritis is often overlooked.MethodsData was retrospectively reviewed on all men presenting at the major STI clinic in Providence, Rhode Island. Predictors of gonorrhea and chlamydia infection were modeled using a generalized model assuming a binary distribution.ResultsOf the men with urethritis, 27% had chlamydia, 13% gonorrhea, 3% both, and 63% neither (non-gonococcal, non-chlamydial urethritis). MSM were more likely to test positive for gonorrhea than MSW (25% of MSM versus 6% of MSW; pConclusionsMSM with urethritis were much more likely to test positive for gonorrhea which may be due to increased risk behaviors and spread within concentrated sexual networks. A large number of both MSM and MSW had non-gonococcal, non-chlamydial urethritis, which suggests the need for improved diagnostic testing. [Full article available at http://rimed.org/rimedicaljournal-2016-06.asp, free with no login]

Application of an automation system and a supervisory control and data acquisition (SCADA) system for the optimal operation of a membrane adsorption hybrid system

The application of automation and supervisory control and data acquisition (SCADA) systems to municipal water and wastewater treatment plants is rapidly increasing. However, the application of these systems is less frequent in the research and development phases of emerging treatment technologies used in these industries. This study involved the implementation of automation and a SCADA system to the submerged membrane adsorption hybrid system for use in a semi-pilot scale research project. An incremental approach was used in the development of the automation and SCADA systems, leading to the development of two new control systems. The first system developed involved closed loop control of the backwash initiation, based upon a pressure increase, leading to productivity improvements as the backwash is only activated when required, not at a fixed time. This system resulted in a 40% reduction in the number of backwashes required and also enabled optimised operations under unsteady concentrations of wastewater. The second system developed involved closed loop control of the backwash duration, whereby the backwash was terminated when the pressure reached a steady state. This system resulted in a reduction of the duration of the backwash of up to 25% and enabled optimised operations as the foulant build-up within the reactor increased. © IWA Publishing 2006