Energy recovery through reverse electrodialysis: Harnessing the salinity gradient from the flushing of human urine.

Urine dilution is often performed to avoid clogging or scaling of pipes, which occurs due to urine's Ca2+ and Mg2+ precipitating at the alkaline conditions created by ureolysis. The large salinity gradient between urine and flushing water is, theoretically, a source of potential energy which is currently unexploited. As such, this work explored the use of a compact reverse electrodialysis (RED) system to convert the chemical potential energy of urine dilution into electric energy. Urine' composition and ureolysis state as well as solution pumping costs were all taken into account. Despite having almost double its electric conductivity, real hydrolysed urine obtained net energy recoveries ENet of 0.053-0.039 kWh/m3, which is similar to energy recovered from real fresh urine. The reduced performances of hydrolysed urine were linked to its higher organic fouling potential and possible volatilisation of NH3 due to its high pH. However, the higher-than-expected performance achieved by fresh urine is possibly due to the fast diffusion of uncharged urea to the freshwater side. Real urine was also tested as a novel electrolyte solution and its performance compared with a conventional K4Fe(CN)6/K3Fe(CN)6 couple. While K4Fe(CN)6/K3Fe(CN)6 outperformed urine in terms of power densities and energy recoveries, net chemical reactions seemed to have occurred in urine when used as an electrolyte solution, leading to TOC, ammonia and urea removal of up to 13%, 6% and 4.4%, respectively. Finally, due to the migration of K+, NH4+ and PO43-, the low concentration solution could be utilised for fertigation. Overall, this process has the potential of providing off-grid urine treatment or energy production at a household or building level.

Volumetric change of the latissimus dorsi muscle after postoperative radiotherapy in immediate breast reconstruction with an extended latissimus dorsi musculocutaneous flap.

BACKGROUND: This study aimed to determine the magnitude of volume reduction of the latissimus dorsi (LD) muscle after treatment using only postoperative radiotherapy (PORTx) in patients who underwent immediate breast reconstruction using an extended LD musculocutaneous (eLDMC) flap after partial mastectomy. METHODS: We retrospectively reviewed 28 patients who underwent partial mastectomy and an eLDMC flap, received only PORTx, and underwent chest computed tomography (CT) 7 to 10 days after surgery and 18±4 months after the end of radiotherapy, from March 2011 to June 2016. The motor nerve to the LD was resected in all patients. One plastic surgeon performed the procedures, and the follow-up period was at least 36 months (mean, 46.6 months). The author obtained LD measurements from axial CT views, and the measurements were verified by an experienced radiologist. The threshold for statistical significance was set at P<0.05. RESULTS: A statistically significant decrease in the LD volume was found after the end of PORTx (range, 61.19%-80.82%; mean, 69.04%) in comparison to the measurements obtained 7 to 10 days postoperatively (P<0.05). All cases were observed clinically for over 3 years. CONCLUSIONS: The size of an eLDMC flap should be determined considering an average LD reduction of 69% after PORTx. Particular care should be taken in determining the size of an eLDMC flap if the LD is thick or if it occupies a large portion of the flap.

Attachment distribution of pectoral muscle origins identified in dual-plane breast implant insertion.

BACKGROUND: Implant-based dual-plane augmentation mammoplasty requires accurate separation of the pectoralis major muscle (PMM) at its origins. The authors identified the PMM origins during breast reconstruction surgery with the goal of providing additional information on subpectoral implant insertion for reconstructive or aesthetic purposes. METHODS: This study was conducted on 67 patients who underwent breast reconstruction surgery at the breast center of our hospital between November 2016 and June 2018. In total, 34 left and 39 right hemithoraces were examined. The left and right hemithoraces were each divided into 15 zones to determine the percentage of PMM attachments in each zone. The distribution of PMM origins in each zone was examined to identify any statistically significant differences. RESULTS: There were no statistically significant differences in the origins of the PMM between the right and left hemithoraces. The percentage of attachments increased moving from the fourth to the sixth rib and from the lateral to the medial aspect. CONCLUSIONS: The anatomical findings of this study could be used as a reference for accurate dissection of the origins of the PMM for the preparation of the subpectoral pocket for subpectoral implant placement.

Reverse osmosis membrane fabrication and modification technologies and future trends: A review.

Reverse osmosis (RO) is the most widely used technology in water treatment and desalination technologies for potable water production. Since its invention, RO has undergone significant developments in terms of material science, process, system optimization, methods of membrane synthesis, and modifications. Among various materials used for the synthesis of an RO membrane, the polyamide thin-film composite (PA-TFC) is by far the most common, owing to its excellent water permeability high salt rejection, and stability. However, a tradeoff between membrane permeability and salt rejection and membrane fouling has been a major hindrance for the effective application of this membrane. Thus, a broad investigation has been carried out to address these problems, and among which co-solvent interfacial polymerization (CAIP) and the surface modification of substrates and active layers of RO membrane have been the most effective approaches for controlling and improving the surface properties of the PA-TFC membrane. In this review paper, the problems associated with the RO membrane processes and strategies has been discussed and addressed in detail. Furthermore, as the focus of this review, the major advancements in the strategies used for enhancement of RO membrane performance through CAIP, and surface modifications were scrutinized and summarized.

A pilot study of spiral-wound air gap membrane distillation process and its energy efficiency analysis.

Brine disposal is a major drawback for seawater desalination. Membrane distillation (MD) is an emerging technology to treat a high saline water including brine disposal instead of reverse osmosis, multi-stage flash and multi-effect distillation. This study investigated a pilot scale of a spiral-wound air gap MD (AGMD) module and evaluated its efficiency. A pilot-scale AGMD module with design production capacity of 10 m3/d was operated. Experiments with varying flow velocity showed increasing trend of water vapor flux as flow velocity increases. The temperature is one of the significant points in maximizing water permeate vapor flux in MD. Increasing temperature from 65 °C to 75 °C in evaporator channel has increased flux from 0.59 to 1.15 L/m2/h. Under various conditions, specific thermal energy consumption (STEC) and gained output ratio (GOR) was used to analyze energy efficiency. The pilot plant showed high GOR value in spite of a limited heating and cooling source available at the site. The highest GOR achieved was 3.54 with STEC of 182.78 kWh/m3. This study provides an overview of operation experience and its data analysis related to temperature, concentration, flow rate and energy supply.

Removal of fluoride in membrane-based water and wastewater treatment technologies: Performance review.

The presence of excess fluoride in aqueous media above local environmental standards (e.g., the U.S. Environmental Protection Agency (EPA) standard of 4 mg/L) affects the health of aquatic life. Excess fluoride in drinking water above the maximum contaminant level (e.g., the World Health Organization (WHO) standard of 1.5 mg/L) also affects the skeletal and nervous systems of humans. Fluoride removal from aqueous solutions is difficult using conventional electrochemical, precipitation, and adsorption methods owing to its ionic size and reactivity. Thus, new technologies have been introduced to reduce the fluoride concentration in industrial wastewater effluents and various drinking water sources. Membrane technology is one of the newer technologies found to be very effective in significantly reducing fluoride to desired standards levels; however, it has received less attention than other technologies because it is perceived as a costly process. This study critically reviewed the performance of various membrane process and compared it with effluent and zero liquid discharge (ZLD) standards. The performance review has been conducted with the consideration of the theoretical background, rejection mechanisms, technical viability, and parameters affecting flux and rejection performance. This review includes membrane systems investigated for the defluoridation process but operated under pressure (i.e., reverse osmosis [RO] and nanofiltration [NF]), temperature gradients (i.e., membrane distillation [MD]), electrical potential gradients (i.e., electrodialysis [ED] and Donnan dialysis [DD]), and concentration differences (i.e., forward osmosis [FO]). Moreover, the study also addressed the advantages, limitations, & applicable conditions of each membrane based defluoridation process.

Membrane-based technologies for zero liquid discharge and fluoride removal from industrial wastewater.

Several defluoridation techniques for reducing high initial fluoride concentration (IFC) in wastewater have been tested, but only a few of them have achieved the permissible standards. This study examined the hybrid crystallization-reverse osmosis technique (HRO) in light of flux, fluoride removal efficiency, fouling tendency, mineral recovery, complying zero liquid discharge (ZLD), and effluent discharge standard (EDS). Simulated wastewater with an IFC of 6600 mg/L was utilized and the final HRO performance was compared with those of the low-pressure (30 bar) standalone reverse osmosis (SRO), nanofiltration (SNF), and membrane distillation (SMD) processes. Accordingly, the study on SRO and SNF revealed that pressure, feed pH, membrane type, and IFC were the major factors affecting performance, and SRO was unable to sufficiently defluoridate wastewater with IFC >614 mg/L, needing pretreatment. Subsequently, the HRO process was selected and it was seen that the optimum calcium dose and respective final effluent pH for attaining EDS and ZLD were 16.5 g/L & 7.1 and 19.8 g/L & 5.7 respectively. The best operating pH for all conditions in HRO was approximately 9. Additionally, HRO showed good mineral recovery tendency and less organic fouling. The overall comparisons of flux and residual fluoride for HRO, SRO, SNF, and SMD were 49.3 LMH & 1.21 mg/L; 34.9 LMH & 62 mg/L, 44.05 LMH & 301 mg/L, and 38 LMH & 0.9 mg/L respectively. Therefore, low-pressure HRO can be applied to treat wastewater with high IFC; good tendency of mineral recovery, as good as that of SMD.

Analysis of mass transfer behavior in membrane distillation: Mathematical modeling under various conditions.

Four commercially available hydrophobic membranes with different pore sizes were separately used in a direct contact membrane distillation (DCMD) apparatus to investigate the effect of fouling on the mass transfer coefficient, and the dominant mass transport mode under different conditions defined by the temperature, membrane material, flow regime, and membrane pore size. Both ultrapure deionized water and simulated industrial wastewater were considered as the feed water. The results of the investigation confirmed that the fouling layer impacted the mass transport directly by resisting it, and indirectly by altering the heat transfer mechanism. In addition to the surface fouling layer, a significant number of particles were also observed to accumulate in the membrane pores. It was further determined that the contribution of Poiseuille flow to the entire mass transport was significant at higher temperatures when using a membrane with large pores. This highlighted the need for careful consideration of Poiseuille flow in the modeling and simulation of a membrane distillation (MD) mass transport process. It was also observed that the flow rate did not affect the Poiseuille flow and therefore did not directly impact the entire mass transfer. The study findings provide systematic insight for the development of a strategy for selecting an appropriate operating feed for DCMD and adjusting the permeate temperature to fit the prevailing water demand and environmental conditions.

Effects of ginsenoside Rg3 on apoptosis in A375.S2 melanoma cells.

BACKGROUND: Malignant melanoma is the most aggressive skin cancer, and metastatic malignant melanoma is very difficult to treat. Ginsenoside Rg3 extracted from ginseng has been reported to have anticancer effects in various kinds of cancer. It has also been reported that Rg3 induced apoptosis and inhibited metastasis of melanoma cells derived from rats, but studies on the anti-cancer effects of Rg3 on melanoma cells originating from humans have been rarely reported. In this study, to investigate whether Rg3 has anticancer effects in human melanoma cells, A375.S2 cells were used to determine whether Rg3 induces apoptosis of malignant melanoma cells and which signaling pathway leads to apoptosis. METHODS: In this study, we conducted in vitro experiments. First, we examined the effect of Rg3 on A375.S2 cells to change cell viability, cell morphology, colony formation ability, and cell motility. And then, through the use of flow cytometric assay, Western blot, and immunocytochemistry, we examined that Rg3-treated melanoma cells were killed through apoptosis. Finally, we examined the signaling pathway of apoptosis by measuring cell viability after treatment with apoptotic kinase inhibitor. RESULTS: As a result, cell viability, cell morphology, colony formation ability, and cell motility of A375.S2 cells treated with Rg3 were changed. After this experiment, we demonstrated that Rg3 induces A375.S2 melanoma cell apoptosis. Also, this apoptosis can be related to the MEK signaling pathway. CONCLUSIONS: We have shown that Rg3 can induce apoptosis of A375.S2 human melanoma cells through this study.

Volatile fatty acids and biogas recovery using thermophilic anaerobic membrane distillation bioreactor for wastewater reclamation.

The effects of bioreactor temperatures and salinities of an anaerobic membrane distillation bioreactor (anMDBR) on the permeation performance and their potential recovery of bioresources were fully examined in this study. To the best of our knowledge, this is the first study of a lab-scale anMDBR process utilizing sub-merged hollow fiber membranes. The hybrid system utilizing both membrane distillation (MD) and anaerobic bioreactors achieved 99.99% inorganic salt rejection regardless the operation temperatures and high initial flux from (2-4 L m-2 h-1) at 45-65 °C. However, after 7-day operation, the flux dropped by 16-50% proportional to the bioreactor temperatures. It was found that the effects of bioreactor temperatures had strong impacts on both the permeation performance and fouling behavior while salinity had insignificant effect. A compact non-porous fouling layer was observed on the membrane surface from the bioreactor operated at 65 °C while only a few depositions was found on the membrane from 45 °C bioreactor. In the present study, the optimal anMDBR temperature was found to be 45 °C, showing a balanced biogas production and membrane permeation performance including less fouling formation. At this bioreactor temperature (45 °C), the biogas yield was 0.14 L/g CODremoval, while maintaining a methane recovery of 42% in the biogas, similar recovery to those at bioreactor temperatures of 55 and 65 °C. The potential recovery of volatile fatty acids made anMDBR a more economically efficient system, in addition to its lower operation cost and smaller footprint compared with most other technologies for on-site wastewater treatment.

Dermoid cysts: Epidemiology and diagnostic approach based on clinical experiences.

BACKGROUND: Dermoid cysts are congenital tumors that are benign. Dermoid cysts with intracranial extension can cause serious neurological complications. It is important, therefore, to determine whether a patient has a dermoid cyst when their chief concern at a doctor's visit is a mass in the head or neck area. In this study, we present a literature review of dermoid cysts and an analysis of the authors' experiences, with the goal of providing guidance useful for the diagnosis and treatment of dermoid cysts. METHODS: This study retrospectively analyzed the medical records of 62 patients who visited the two medical clinics with which the authors are affiliated. The patients were enrolled between October 2003 and January 2017. RESULTS: Of the 62 patients analyzed in this study, 32 were 0 to 5 years of age (52%) and 23 were 17 years of age or older (37%). Forty-seven patients underwent 1 or more imaging study during the process of diagnosis. Thirty-two patients were suspected to have a dermoid cyst. Forty-nine patients were analyzed to determine the depth of the cyst. Bone was seen in 43 patients through imaging tests or during actual surgery, and nine of the 43 had bony problems (21%). CONCLUSIONS: This study found that dermoid cysts were present in many adults, and that a high rate of deep lesions was observed, as well as many cases in which even the bone was affected. These results suggest, therefore, that dermoid cysts should be considered, and medical professionals should actively conduct imaging studies.

A rare case of isolated schwannoma in infraorbital nerve.

A schwannoma is a benign tumor that develops from Schwann cells. It is known to occur more frequently in women than men, and about one third of schwannoma cases occur in the head and neck area. It is also known to originate mainly in the auditory nerve. However, it is rarely associated with the trigeminal nerve, and especially, schwannomas related to the infraorbital nerve are very rare. we report a rare case of a schwannoma involving the infraorbital branch of the trigeminal nerve in a 45-year old male adult. The patient underwent physical examination and magnetic resonance imaging. The mass was approached through subciliary approach that is familiar to the plastic surgeon and completely resected. Histopathological findings showed pointed to a benign schwannoma. Infraorbital nerve schwannoma is difficult to distinguish from other diseases by means of clinical symptoms, physical findings, or imaging. In spite of its rarity, infraorbital nerve schwannoma may be considered a possible diagnosis in the case of mass on cheek. Assessment by computed tomography or magnetic resonance imaging is necessary for proper diagnosis. About the surgical approach, excision through the subciliary approach should be considered rather than the direct transfacial approach in view of stability, cosmetic effects, and familiarity.

Evaluation of the donor site after the median forehead flap.

BACKGROUND: Forehead flaps are useful for facial reconstruction. Studies of these flaps have mostly focused on the results of the reconstruction. However, due to the scarring and changes on the forehead caused by the median forehead flap (MFF), surgeons may be reluctant to perform this flap. Research into the donor site is needed for practical purposes. METHODS: We examined 42 patients who underwent an MFF at Pusan National University Hospital from 1996 to 2016. Based on a retrospective chart review, we examined the occurrence of complications. We also evaluated scars on the forehead using the Vancouver Scar Scale (VSS) and assessed changes in the eyebrow position of 22 patients. RESULTS: No complications occurred in the 42 patients. The mean VSS score of the 22 patients was 2.8±0.79. The ratio of the height of the eyebrow on each side to the distance between the medial canthi increased postoperatively, meaning that both the left and right brows were elevated slightly (P=0.026 and P=0.014). However, the symmetry between the left and right sides did not change (P=0.979). The ratio of the interbrow distance to the distance between the medial canthi decreased slightly, meaning that the interbrow distance narrowed mildly (P<0.001). Moreover, there were no noticeable changes in the brow position as seen in a photo overlay. CONCLUSIONS: There were no notable complications in the forehead. Forehead scarring was acceptable. No change in brow symmetry was observed via photographic measurements and a photo overlay. Therefore, we propose that the MFF is a useful choice for minimizing scarring or deformation of the donor site.

Membrane distillation for industrial wastewater treatment: Studying the effects of membrane parameters on the wetting performance.

Substantial amounts of trace hazardous elements have been detected in industrial wastewater (e.g fluoride > 900 mg/L). Feed water characteristics, operational parameters, and membrane properties are major factors affecting flux and rejection of the MD process. Membrane parameters such as membrane material type and pore size have been investigated. Fluoride ion rejection was selected to setup a methodology to remove trace elements from wastewater by adjusting the membrane parameters in DCMD. Study of the fouling thickness of the MD membrane using pH and feed water composition revealed that a PVDF membrane with a smooth surface holds a thicker fouling layer, which enhances fluoride rejection while reducing the permeate flux. On the other hand, PTFE and PP membranes showed higher mass transfer and higher wetting performance, respectively. Therefore,a PVDF membrane with low organic feed water at higher alkaline pH can be utilized to obtain high-quality permeate, while PTFE can provide the highest flux with acceptable permeate water quality. Therefore, this methodology can be applied toidentify the optimum membrane to fit the required permeate flux, rejection requirements,and operating pH to treat any kind of non-volatileinorganic pollutants from industrial wastewater.

Intraosseous hemangioma of the orbit.

Intraosseous hemangioma is an extremely rare tumor that accounts for 1% or fewer of all osseous tumors. The most common sites of its occurrence are the vertebral column and calvaria. Occurrence in a facial bone is very rare. The authors aim to report a case of the surgical treatment of intraosseous hemangioma occurring in the periorbital region, which is a very rare site of occurrence and to introduce our own experiences with the diagnosis and treatment of this condition along with a literature review. A 73-year-old male patient visited our hospital with the chief complaint of a mass touching the left orbital rim. A biopsy was performed by applying a direct incision after local anesthesia. Eventually, intraosseous hemangioma was diagnosed histologically. To fully resect the mass, the orbital floor and zygoma were exposed through a subciliary incision under general anesthesia, and then the tumor was completely eliminated. Bony defect was reconstructed by performing a seventh rib bone graft. Follow-up observation has so far been conducted for 10 months after surgery without recurrence or symptoms.

Hierarchical Composite Membranes with Robust Omniphobic Surface Using Layer-By-Layer Assembly Technique.

In this study, composite membranes were fabricated via layer-by-layer (LBL) assembly of negatively charged silica aerogel (SiA) and 1H,1H,2H,2H-perfluorodecyltriethoxysilane (FTCS) on a polyvinylidene fluoride phase inversion membrane and interconnecting them with positively charged poly(diallyldimethylammonium chloride) (PDDA) via electrostatic interaction. The results showed that the PDDA-SiA-FTCS coated membrane had significantly enhanced the membrane structure and properties. New trifluoromethyl and tetrafluoroethylene bonds appeared at the surface of the coated membrane, which led to lower surface free energy of the composite membrane. Additionally, the LBL membrane showed increased surface roughness. The improved structure and property gave the LBL membrane an omniphobic property, as indicated by its good wetting resistance. The membrane performed a stable air gap membrane distillation (AGMD) flux of 11.22 L/m2 h with very high salt rejection using reverse osmosis brine from coal seam gas produced water as feed with the addition of up to 0.5 mM SDS solution. This performance was much better compared to those of the neat membrane. The present study suggests that the enhanced membrane properties with good omniphobicity via LBL assembly make the porous membranes suitable for long-term AGMD operation with stable permeation flux when treating challenging saline wastewater containing low surface tension organic contaminants.

Reconstruction of Large Facial Defects via Excision of Skin Cancer Using Two or More Regional Flaps.

BACKGROUND: Free-flap surgery and skin grafting can be used to reconstruct large facial defects that may result after skin cancer removal by Mohs micrographic surgery (MMS). However, these two methods may produce low postsurgical patient satisfaction with aesthetics, and free-flap surgery may produce an undue burden for the majority of skin cancer patients, who are of advanced age. Hence, the authors examined outcomes of large facial defect reconstruction using multiple flaps. METHODS: Among patients undergoing MMS for skin cancer at Pusan National University Hospital between January 2013 and December 2015, we evaluated 7 patients (2 males, 5 females; average age, 73.14 years) treated for large facial defects from basal cell carcinoma. Based on operative and follow-up records, we investigated the number and type of flaps used, postsurgical complications, and patients' post-surgical satisfaction. RESULTS: Two and 3 types of flaps were used for 5 and 2 patients, respectively. Most frequently used were nasolabial flaps (7 times in 6 patients) and forehead flaps (once in each of 4 patients). The average follow-up period was 14 months, with no complications-including necrosis, hematoma, or wound dehiscence-observed. Post-surgical satisfaction averaged 4.4 out of a maximum of 5 points. CONCLUSIONS: Reconstruction using two or more flaps for large facial defects after skin cancer removal using MMS produced satisfactory outcomes while preventing aesthetic problems. Practitioners should consider using multiple flaps when choosing a reconstruction method for large facial defects following skin cancer removal.

Effects of various chemical cleaning conditions for pressured MF process.

A pilot-scale pressured hollow-fiber microfiltration (MF) process as pretreatment for the reverse osmosis process was studied and operated under various conditions to assess the relative influence of backwashing, chemical enhanced backwashing (CEB), and bag filter application. The pilot plant process consisted of backwashing but without the CEB or the bag filter as the first step of the research. As the second step of the research, the impact of the backwashing on permeability recovery was assessed at different intervals followed by the influence of CEB on flowrate recovery. Results from operating the pilot-scale hollow-fiber membrane modules for more than 1 year have demonstrated that the appropriate pore size of bag filters was 25-50 µm and the optimized backwashing process was every 30 minutes with 25 mg/L of NaOCl, and CEB with an interval of 10 cycles with the use of 100 mg/L NaOCl.

A novel multi-stage direct contact membrane distillation module: Design, experimental and theoretical approaches.

An economic desalination system with a small scale and footprint for remote areas, which have a limited and inadequate water supply, insufficient water treatment and low infrastructure, is strongly demanded in the desalination markets. Here, a direct contact membrane distillation (DCMD) process has the simplest configuration and potentially the highest permeate flux among all of the possible MD processes. This process can also be easily instituted in a multi-stage manner for enhanced compactness, productivity, versatility and cost-effectiveness. In this study, an innovative, multi-stage, DCMD module under countercurrent-flow configuration is first designed and then investigate both theoretically and experimentally to identify its feasibility and operability for desalination application. Model predictions and measured data for mean permeate flux are compared and shown to be in good agreement. The effect of the number of module stages on the mean permeate flux, performance ratio and daily water production of the MDCMD system has been theoretically identified at inlet feed and permeate flow rates of 1.5 l/min and inlet feed and permeate temperatures of 70 °C and 25 °C, respectively. The daily water production of a three-stage DCMD module with a membrane area of 0.01 m2 at each stage is found to be 21.5 kg.