Purification of harvested rainwater using slow sand filters with low-cost materials: Bacterial community structure and purifying effect.

Slow sand filters (SSFs) have been shown to effectively improve water quality. The aim of the present study was to obtain low-cost materials (LCMs) as filter mediums (FMs) to efficiently purify harvested rainwater and to document the relationship between bacterial community structure and water purification. The red clay was mixed with crushed limestone and crushed brick, respectively. The mixtures or brick powder were used as the filter media for SSFs. Laboratory column tests were conducted in conjunction with the monitoring of representative water quality parameters (COD, NH4+, CFU and total coliforms) to estimate the performance of low-cost material slow sand filters (LCM-SSFs), including the time needed for biofilm maturation. The relationship between bacterial community structure and SSF performance was determined using a combination of 16S rRNA gene sequencing and an array of statistical techniques. The results demonstrated that LCM-SSFs perform well in purifying harvested rainwater, and are of superior economic benefit. LCMs had a stronger adsorptivity than quartz sand, which enhanced the purification of harvested rainwater before the biofilms matured, and shorten the time required for biofilm maturation. During the 90-day laboratory experiment, a mixture of crushed limestone and red clay exhibited the best performance. The abundance of Opitutae could be used as a potential indicator of NH4+ removal efficiency by SSFs. Schmutzdecke was characterized by abundant, diverse and evenly distributed bacterial communities that produced rich, stable and robust environmental functions, and that possessed an excellent purifying capacity. Environmental conditions associated with low ecological stress, such as neutral pH filter mediums and lucifugal experimental conditions, were conducive to the diversity and evenness of effluent bacterial communities and improved the performance of LCM-SSFs in purifying harvested rainwater.

Laparoendoscopic single-site urethrovesical anastomosis training in an economical porcine model.

PURPOSE: To develop an economical animal model for laparoendoscopic single-site surgery (LESS) urethrovesical anastomosis (UVA) training. MATERIALS AND METHODS: A homemade single-port device was used and the uterus cervix and the ileum were chosen to simulate UVA to reduce costs. Ten trainees were randomly divided into two groups: the conventional LESS UVA (CLUVA) group and the transurethral assistant LESS UVA (TALUVA) group. In TALUVA, a laparoscopic forceps was inserted through the urethra to assist operation after the bladder neck was disconnected, whereas CLUVA followed the conventional steps. Anastomosis time and knotting time were recorded, and the learning curves of both groups were analyzed. After training, questionnaires were given to the trainees to assess the difficulties and the satisfaction of the training. RESULTS: The final mean operating time significantly declined in both groups. Except for the first lesson, the trainees in the TALUVA group operated faster than those in the other group. The results from the questionnaires show that all trainees were satisfied with the training, and LESS UVA was considered more difficult in the CLUVA group than in the TALUVA group. CONCLUSIONS: The female porcine model for LESS UVA was feasible and cost-effective. TALVUA could effectively reduce the difficulties involved in LESS UVA.

Retroperitoneal laparoendoscopic single-site radical nephrectomy using a low-cost, self-made device: initial experience with 29 cases.

OBJECTIVES: To introduce a low-cost, self-made device for single-port retroperitoneal laparoscopic radical nephrectomy and to evaluate outcomes compared with conventional laparoscopy after initial experience using this device. METHODS: Twenty-nine renal cancer patients underwent retroperitoneal laparoendoscopic single-site radical nephrectomy using a self-made single-port device with multiple manipulation channels for passage of routine laparoscopic instruments and specimen removal. A control group of 29 patients who were matched by age, gender, and cancer stage underwent conventional laparoscopy. Outcomes were analyzed retrospectively. RESULTS: There were no significant differences in age, gender, body mass index, T stage, and maximum tumor diameter between groups (P > .05). The laparoendoscopic single-site surgery group had a significantly shorter duration of postoperative hospitalization than the conventional laparoscopy group (7.14 ± 1.38 days vs 8.17 ± 1.54 days, P = .009). CONCLUSIONS: Retroperitoneal laparoscopic radical nephrectomy using our self-made single-port device appears to be a feasible, safe, and low-cost surgical strategy.