Enhancing the mediated electrochemical reduction process combined with developed liquid-gas electrochemical flow sensors for sustainable N2O removal at room temperature.

New electrocatalysts with high reduction efficiency are needed to upgrade the mediated electrochemical reduction for real applications. In addition, automation is required to quantify active electrocatalysts in alkaline media and air pollution. In this study, N2O was removed sustainably by electrogenerated low valent nickel(I) phthalocyanine tetrasulfonate [Ni(I)TSPc] in 1 M KOH using an electroscrubbing system. Ni(I)TSPc electro generation and N2O removal were automated by two (liquid/gas) electrochemical flow sensors, respectively. The Ni(I)TSPc was generated electrochemically up to 95% in 1 M KOH, and high removal efficiency (100%) was observed for 5 ppm N2O and 90% for 10 ppm N2O. A limiting potential change in the in-situ LSV of the chemically synthesized Ni(I)TSPc was taken and derived from the calibration plot and validated by an ex-situ potentiometric titration using an oxygen reduction potential electrode. Using the obtained calibration plot, electrogenerated Ni(I)TSPc allowed a direct determination in a liquid flow cell. The gas flow sensor developed using a KOH/Ni(II)CN4 (TCN (II))-fabricated silver solid amalgam electrode showed an excellent response to N2O concentrations up to 32 ppm. A calibration plot with known concentration was derived and validated by gas chromatography. The response time and sensitivity obtained were approximately 500s and -0.012 mA ppm-1 cm-2, respectively. The sensor stability test confirmed its good stability. Finally, the developed in-situ electrochemical flow sensors were applied to the sustainable automation of N2O pollutant removal.

Electrochemically generated bimetallic reductive mediator Cu1+[Ni2+(CN)4]1- for the degradation of CF4 to ethanol by electro-scrubbing.

Remediation of electronic gas CF4 using commercially available technologies results in another kind of greenhouse gas and corrosive side products. This investigation aimed to develop CF4 removal at room temperature with formation of useful product by attempting an electrogenerated Cu1+[Ni2+(CN)4]1- mediator. The initial electrolysis of the bimetallic complex at the anodized Ti cathode demonstrated Cu1+[Ni2+(CN)4]1- formation, which was confirmed by additional electron spin resonance results. The degradation of CF4 followed mediated electrochemical reduction by electrogenerated Cu1+[Ni2+(CN)4]1-. The removal efficiency of CF4 of 95% was achieved by this electroscrubbing process at room temperature. The spectral results of online and offline Fourier transform infrared analyzer, either in gas or in solution phase, demonstrated that the product formed during the removal of CF4 by electrogenerated Cu1+[Ni2+(CN)4]1- by electroscrubbing was ethanol (CH3CH2OH), with a small amount of trifluoroethane (CF3CH3) intermediate.

The electrochemical oxidation of toluene catalysed by Co(II) in N-butyl-N-methylpyrrolidinium bis(trifluoromethylsulfonyl)imide.

The electrochemical oxidation of toluene in N-butyl-N-methylpyrrolidinium bis(trifluoromethylsulfonyl)imide ([bmpyr](+)[Ntf2](-)) was investigated by using cyclic voltammetry and galvanostatic electrolysis in the presence of Co(II) at a Pt disc working electrode. Cyclic voltammetry (CV) investigations revealed that Co(II)-Co(III) oxidation is a diffusion controlled electron transfer process. The diffusion coefficient values of Co(II) were found to increase from 0.38 × 10(-7) to 1.9 × 10(-7) cm(2) s(-1) as the temperature was increased from 25 °C to 80 °C. The CV peak current for toluene electro-oxidation increased by nearly 7 fold in the presence of Co(II) demonstrating a good catalytic effect. Co(II) catalysed galvanostatic electrolysis of toluene at room temperature has shown that benzaldehyde was formed along with a small quantity of 3-methyl-1-hexanol.

Combined use of rituximab and plasmapheresis pre-transplant increases post-transplant infections in renal transplant recipients with basiliximab induction therapy.

INTRODUCTION: We investigated the effect of combined use of rituximab (RTX) and plasmapheresis (PP) pre-transplant on post-transplant infection. METHODS: A total of 196 patients undergoing living-donor kidney transplantation at Seoul St. Mary's Hospital, all of whom underwent basiliximab induction therapy, were included in the study. They were divided into 3 groups: RTX/PP/intravenous immune globulin (IVIG) (the RPI group; n = 53), RTX monotherapy (the RTX group; n = 14), and control (the CONT group; n = 129). We compared the post-transplant infections in the 3 groups. RESULTS: The overall prevalence of infection was significantly higher, and the infection-free survival rate was lower, in the RPI group compared with the RTX or CONT groups (P < 0.05). A trend toward more severe bacterial infections was seen in the RPI group compared with the other groups, and fungal infections developed only in the RPI group. After anti-rejection therapy, a significantly higher rate of infection developed in the RPI group than in the other groups (P < 0.05). In addition, the RPI group was an independent risk factor for the development of infection. CONCLUSION: Our results show that in the setting of basiliximab induction, the use of combined RTX and PP therapy pre-transplant significantly increases the risk for post-transplant infection.

Cerium-polysulfide redox flow battery with possible high energy density enabled by MFI-Zeolite membrane working with acid-base electrolytes.

A pH change can enable high-energy-density RFB (redox flow battery) in an aqueous medium. Nevertheless, a membrane to prevent the ion crossover is needed. This study adopted cerium and polysulfide in an acid-base combined electrolyte with an MFI-Zeolite membrane as a separator. The increased potential with pH change is described by the OCP (open circuit potential) difference, which varies by 0.8 V for the combination of acid-acid and acid-base electrolyte. A decrease of 350 mV at the redox peak potential of Ce3+/Ce4+ and a 10 mV negative potential shift for S42-/2S22- highlights the pH effect between the combination of acid-acid and acid-base electrolyte indicates the influence of pH leading in half-cell of anodic than the opposite cathodic side. The UV-visible spectral analysis for Ce3+ and S42- ions displacement shows that cerium and sulfur ions do not migrate to each other half-cell through an MFI-Zeolite membrane. As a result, the current efficiency of 94%, voltage, and energy efficiency of 40%-43% were attained at a current density of 10 mA cm-2. Moreover, the acid-base composition of the Ce/S system showed an energy density of 378.3 Wh l -1.

Enhanced sustainable electro-generation of a Ni (I) homogeneous electro-catalyst at a silver solid amalgam electrode for the continuous degradation of N2O, NO, DCM, and CB pollutants.

This paper reports the sustainable and enhanced generation of a Ni(I) active electro-catalyst using AgSAE as a cathode material for the sustainable degradation of N2O, NO, dichloromethane (DCM), and chlorobenzene (CB) by electroscrubbing in a series operation. The AgSAE electrode showed 1.66 times higher Ni(I) formation than the Ag metal electrode. The AgSAE achieved 20% ± 2% Ni(I) generation in a highly concentrated alkaline medium, whereas Ag metal only achieved 12% ± 2% Ni(I) generation at the same current density. Electrochemical impedance spectroscopy and voltammetric studies determined that the kinetics of the charge-transfer reaction was also preferential at the AgSAE, with the cathodic peak at -1.26 V vs. Ag/AgCl confirming Ni(I) formation. Initially, the change in the oxygen reduction potential and reduction efficiency of Ni(I) confirmed the removal of N2O, NO, DCM and CB. In addition, the gas Fourier transform infrared (FTIR) spectrum revealed 99.8% removal efficiency of toxic pollutants. Therefore, the regeneration of Ni(I) confirmed the sustainable removal of toxic pollutants. Furthermore, the FTIR spectra revealed the formation of NH3 during the reduction of N2O and NO. On the other hand, DCM and CB were reduced to benzene derivatives in the solution phase. In addition, a plausible reduction mechanism was derived. As a result, the AgSAE cathode exhibited two-fold higher removal efficiency of N2O, NO, DCM, and CB than the previously reported electrodes.

Sustainable removal of N2O by mediated electrocatalytic reduction at ambient temperature electro-scrubbing using electrogenerated Ni(I) electron mediator.

Direct catalysis is generally proposed for nitrous oxide (N2O) abatement but catalysis is expensive, requires high temperatures, and suffers from media fouling, which limits its lifetime. In the present study, an ambient temperature electroscrubbing method was developed, coupling wet-scrubbing with an electrogenerated Ni(I) ([Ni(I)(CN)4]3-) mediator, to enable N2O reduction in a single process stage. The initial studies of 10 ppm N2O absorption into 9 M KOH and an electrolyzed 9 M KOH solution showed no removal. However, 95% N2O removal was identified through the addition of Ni(I) to an electrolyzed 9 M KOH. A change in the oxidation/reduction potential from -850 mV to -650 mV occurred following a decrease in Ni(I) concentration from 4.6 mM to 4.0 mM, which confirmed that N2O removal was mediated by an electrocatalytic reduction (MER) pathway. Online analysis identified the reaction product to be ammonia (NH3). Increasing the feed N2O concentration increased NH3 formation, which suggests that a decrease in electrolyzed solution reactivity induced by the increased N2O load constrained the side reaction with the carrier gas. Importantly, this study outlines a new regenerable method for N2O removal to commodity product NH3 at ambient temperature that fosters process intensification, overcomes the limitations generally observed with catalysis, and permits product transformation to NH3.

Infectious complications in living-donor liver transplant recipients: a 9-year single-center experience.

BACKGROUND: Infectious complications following living-donor liver transplantation (LDLT) remain a major cause of morbidity and mortality. We analyzed the frequency and type of infectious complications according to the post-transplantation period, and their risk factors with regard to morbidity and mortality. METHODS: We retrospectively analyzed 208 subjects who had undergone LDLT during a 9-year period. RESULTS: The rate of infection was 1.69 per patient during the study period. The predominant infections were intra-abdominal infections (37.6%), primary bacteremia (17.4%), and pneumonia (14.5%). Within the first post-transplant month, 140 (39.9%) infections were detected, and catheter-related coagulase-negative staphylococci (44) were the most common infectious agents. During the 2-6-month post-transplant period, 109 infectious episodes occurred (31.1%), and Enterococcus sp. (n=16) related to biliary infection was the most frequent isolate. After the sixth month, 96 infectious episodes (29%) occurred, and biliary tract-related Escherichia coli (n=19) was the major causative organism. The overall mortality was 24.5% (51/208); 1-year survival rate was 88% (196/208). Post-transplant infection-related mortality was 52.9% (27/51). Biliary tract complications, such as biliary stenosis or leakage, significantly increased the mortality (P=0.01); however, reoperation (retransplantation or resurgery for biliary tract obstruction/leakage or to control bleeding) significantly reduced the mortality (P=0.01). CONCLUSIONS: Our data showed that early catheter removal would mainly aid in reducing infectious complications in the 1-month post-transplantation period. Aggressive management, including reoperation, would lower the mortality in the LDLT recipients.

Reconstruction of three right hepatic veins using cadaveric iliac vein in right lobe living donor liver transplantation: case report.

In various right hepatic vein anatomies, reconstruction is a surgically challenging technique in right lobe living donor liver transplantation. The right inferior hepatic vein is the most common hepatic vein abnormality in right lobe living-donor liver transplantation. Three accessory right hepatic veins is a rare right hepatic vein variation. We experienced one case of three right hepatic vein reconstruction among 300 partial liver transplantations using the right lobe in our center over 10 years. The donor right lobe had one main right hepatic vein and three accessory hepatic veins at the lower border of the liver. Restoration of accessory hepatic veins to the inferior vena cava was performed after construction of one conduit from the three accessory hepatic veins using a cadaveric donor iliac vein.

Minimal skin incision in living kidney transplantation.

Usually, the transplanted kidney is placed into the right retroperitoneal iliac fossa through a right abdominal surgical skin incision. The skin incision may be oblique or inverted J-shaped known as the "hockey stick." The oblique or curvilinear incision, parallel to the inguinal ligament, known as the "pelvic Gibson incision," is also extended medially to the midline, just above the pubis. The most common incision for kidney transplantation in our center is a paramedian incision, which is parallel to rectus abdominis muscle and extends medially to the midline, just above the pubis symphysis ("hockey stick"). Nowadays, minimally invasive surgery is popular in various field of surgery; the number of patients who are concerned about cosmetic effects are increasing. We make the skin incision in the lower right abdomen from laterally below the anterior superior iliac spine to the midline just above the pubis in five young unmarried women whose body mass index was >25 and there were no anatomic variations. The lower transverse abdominal skin incision showed more favorable cosmetic results and there was no difference in postoperative factors, including renal function, compared with other routine renal transplant patients.

Surgical techniques according to anatomic variations in living donor liver transplantation using the right lobe.

OBJECTIVES: In living donor liver transplantation, the right lobe has many anatomic variations in the vascular tree, which could lead to surgical complications. We need to define surgical technique according to anatomy. METHODS: From January 2000 to September 2007, 310 living donor liver transplantations using the right lobe were performed in patients with end-stage liver disease. The vascular trees were evaluated preoperatively with computed tomography and magnetic resonance angiography. We classified anatomic points for safe harvest in the hepatic artery, portal vein, and hepatic vein and described technical points based on anatomic variations. RESULT: There were many anatomic variations in the hepatic vasculature. Hepatic artery variations were observed in 16.8% of cases. Double hepatic artery was observed in 14 cases (4.5%). Of these 14 cases, reconstruction as a single artery was performed in 6 and dual reconstruction was performed in 8 cases. Portal vein variation was observed in 45 cases (14.5%): Dual anastomosis to right and left portal vein was performed in type III (n = 20; 6.4%) and type IV (n = 3; 1.0%) variations. There were 70 cases of portal vein thrombosis. In 8 of the 70, a jump or interposition graft with iliac vein was utilized. Of the middle hepatic vein variant, segment V vein only was reconstructed in 188 (60.6%) cases. In 21 (6.8%) cases, segment VIII vein only was reconstructed, and in 43 (13.9%) cases, both segment V and segment VIII veins were reconstructed using the recipient's portal vein, a cryopreserved iliac vein, or a prosthetic graft. The most common variation of right inferior hepatic vein was type II (n = 141; 45.5%), which has 1 right inferior hepatic vein. CONCLUSION: Living donor liver transplantation using the right lobe can be performed safely, but there is a potential operative risk because of various anatomic variations. To minimize operative complications, anatomic variations should be kept in mind to ensure a safe and successful operation.

Kidney Transplantation Using Expanded-Criteria Deceased Donors: A Comparison With Ideal Deceased Donors and Non-Expanded-Criteria Deceased Donors.

PURPOSE: The use of expanded-criteria deceased-donor (ECD) kidneys must be evaluated within the objective perspective of critical organ shortage and graft function and survival. In this study, we aimed to compare the clinical outcomes of ECD reliance with concurrent use of ideal-criteria deceased donors (IDDs) and non-ECDs in adult renal transplantation. METHODS: Between February 2000 and December 2015, we analyzed 405 deceased-donor renal transplants, specifically 129 grafts (31.9%) from ECDs, 233 grafts (57.5%) from non-ECDs, and 43 grafts (10.6%) from IDDs. ECDs were classified according to the United Network for Organ Sharing guidelines, while an IDD was defined as a younger person (10-39 years of age) with no medical risk factors who died from a traumatic head injury. Donor and recipient risk factors were separately analyzed and correlated with recipient graft function, and survival was evaluated. RESULTS: ECDs were older (56.8 ± 6.3 years); showed increased incidence of hypertension, diabetes, and cerebrovascular brain death; and had a higher pre-retrieval serum creatinine level than the other groups. ECD kidney recipients were also older (50.6 ± 9.8 years), had a shorter waiting time (P = .031), and demonstrated a low frequency of re-transplantation (P = .028). Long-term renal function followed longitudinally was lower in ECD kidney recipients until five years after transplantation, while the glomerular filtration rate (GFR) level at 7 and 10 years did not differ significantly among the groups (P = .074 and .262, respectively). There were no significant differences in terms of graft survival (P = .394) or patient survival (P = .737) among the groups. CONCLUSIONS: Although the long-term renal function followed longitudinally was lower in ECD kidney recipients, the use of renal grafts from ECDs is an acceptable method to resolve the disparity of critical organ shortage. However, the classification of the high-risk group should be updated with consideration given to differences in regional characteristics.

Destruction of EDTA by mediated electrochemical oxidation process: monitoring by continuous CO2 measurements.

The mediated electrochemical oxidation (MEO) process with cerium(IV) in nitric acid as the oxidizing medium was employed for the destruction of ethylenediaminetetraacetic acid (EDTA) in batch and continuous feeding modes. A complete mineralization of EDTA to CO(2) and water was achieved. The system parameters studied were the temperature (343, 353 and 368 K), concentration of nitric acid (2, 3 and 4M), Ce(IV) concentration (0.7-0.95 M), aqueous EDTA concentration (67-268 mM) , flow rate of EDTA addition (3.0-7.5 ml/min), and feeding time (30 min and 2h). The batch process CO(2) pattern clearly showed two distinct kinetic regimes. Accordingly the overall CO(2) formation rate constants were evaluated for fast and slow processes using pseudo first-order kinetics. In case of continuous organic feeding, the CO(2) formation rate constant was obtained using a new proposed mathematical procedure based on geometrical progression. The only parameter in the calculations was the first-order rate constant. The theoretical CO(2) evolution pattern was fitted on to the experimental data to obtain the formation rate constants. The activation energy was calculated based on the CO(2) formation constants and presented. The application of mathematical procedure predicted a steady-state attainment of CO(2) evolution for the destruction process during a long-term organic feeding and observed experimentally.

Preliminary studies using hybrid mediated electrochemical oxidation (HMEO) for the removal of persistent organic pollutants (POPs).

This study investigates the hybrid mediated electrochemical oxidation (HMEO) technology, which is a newly developed non thermal electrochemical oxidation process for organic destruction. A combination of ozone and ultrasonication processes to the mediated electrochemical oxidation (MEO) process is termed as hybrid mediated electrochemical oxidation. The electrochemical cell was developed in this laboratory. In the present study, several organic compounds, such as phenol, benzoquinone and ethylenediaminetetraacetic acid (EDTA), were chosen as the model organic pollutants to be destructed by the hybrid process. The organic destruction was monitored based on the CO2 generation and total organic carbon (TOC) reduction. The HMEO process was found to be extremely effective in the destruction of all the target organics chosen in this study. The information obtained from this study will provide an insight in adopting this technique for dealing with more recalcitrant organics (POPs).

Innovative reductive remediation of carbon tetrafluoride at room temperature by using electrogenerated Co1.

Among the non-CO2 greenhouse gases, carbon tetrafluoride (CF4) is the most recalcitrant and should be eliminated from the atmosphere. In the present study, a non-combustion electroscrubbing method was used in an attempt to degrade CF4 with an electrogenerated Co1+ mediator in a highly alkaline medium. The initial absorption experiments revealed 165mgL-1 CF4 gas dissolved in 10M NaOH. Different mediator precursors, [Co(II)(CN)5]3-, [Ni(II)(CN)4]2-, [Cu(II)(OH)4]2-, and [Co(II)(OH)4]2-, were used and the electroscrubbing results showed that the electrogenerated Co1+ or [Co(II)(OH)4]2- precursor effectively degraded up to 99.25% of the CF4 gas. The variations in [Co(II)(OH)4]2- reduction efficiency and cyclic voltammetry revealed CF4 degradation followed by electrogenerated Co1+ mediated reduction. The increased zeta potential (+6mV) of the electrogenerated Co1+ showed that the degradation reaction occurs preferably at the solution interface. Electroscrubbing for CF4 removal and the resulting products were controlled by the carrier gas. Air and H2 carrier gases lead to the formation of CHF3 and COF2. N2 as the carrier gas caused 99.25% degradation with ethanol as a product. An 80% CF4 degradation efficiency with CHF3 as the product was observed when a mixture of N2 and air was used as the carrier gas.

Benefits of active middle ear implants over hearing aids in patients with sloping high tone hearing loss: comparison with hearing aids.

In this retrospective chart review we compared the subjective and objective benefits of active middle ear implants (AMEIs) with conventional hearing aids (HAs) in patients with sloping high tone hearing loss. Thirty-four patients with sensorineural hearing loss were treated with AMEIs. Of these, six had sloping high tone hearing loss and had worn an HA for more than 6 months. Objective assessments, a pure-tone audiogram, as well as a word recognition test, and the Korean version of the Hearing in Noise Test (K-HINT), and a subjective assessment, the Abbreviated Profile of Hearing Aid Benefit (APHAB) questionnaire, were performed. Tests were conducted under three circumstances: 1) the unaided state before surgery; 2) the HA-aided state before surgery; and 3) the AMEI-aided state 3 months after surgery. The average high-frequency hearing gain (≥ 2 kHz) was significantly better with AMEIs than with HAs. Although the result had no statistical significance, AMEIs showed a superior word recognition score (WRS) compared to HAs. However, the most comfortable hearing level at which the WRS was tested was significantly decreased with an AMEI compared to an HA. In the K-HINT, patients with an AMEI showed greater recognition than those fitted with an HA under both quiet and noisy conditions. The APAHB scores revealed that patients were more satisfied with an AMEI rather than an HA on all subscales. The use of vibroplasty in patients with sloping high tone loss resulted in positive hearing outcomes when compared to conventional HAs. Based on the data from this study, AMEIs provided better objective and subjective results and could, therefore, be a better alternative for the treatment of sloping hearing loss.

Progression of Osteoporosis After Kidney Transplantation in Patients With End-Stage Renal Disease.

BACKGROUND: This study investigated the prevalence of osteoporosis and the risk factors for its progression in kidney transplant recipients (KTRs). METHODS: Dual energy X-ray absorptiometry was used to prospectively measure changes in bone mineral density (BMD) before kidney transplantation (KT) and 1 year after transplantation in 207 individuals. We also analyzed the risk factors of osteoporosis progression during this period. RESULTS: Prior to KT, the mean BMD score (T-score of the femur neck area) was -2.1 ± 1.2, and the prevalence of osteoporosis was 41.5% (86/207). At 1 year post-transplantation, the mean BMD score significantly decreased to -2.3 ± 1.1 (P < .001), and the prevalence of osteoporosis increased to 47.3% (98/207; P = .277). The BMD score worsened over the study period in 69.1% (143/207) of patients, improved in 24.1% (50/207), and showed no change in 6.8% (14/207). Minimal intact parathyroid hormone (iPTH) improvement after KT was found to be an independent risk factor of osteoporosis progression. CONCLUSIONS: This study demonstrates progressive loss of BMD after KT and sustained secondary hyperparathyroidism might influence the progression of osteoporosis.

Effect of Donor-Recipient Age Match in Expanded Criteria Deceased Donor Kidney Transplantation.

PURPOSE: Our objective was to investigate the effects of age on patient and graft survival in expanded criteria donor (ECD) renal transplantation. METHODS: Between February 2000 and December 2015, we analyzed 405 deceased donor renal transplants, including 128 grafts (31.9%) from ECDs. Based on recipient age and ECD criteria classification, the recipients were divided into four groups: Group I, non-ECD to recipient age <50 years; Group II, non-ECD to recipient age ≥50 years; Group III, ECD to recipient age <50 years; and Group IV, ECD to recipient age ≥50 years. RESULTS: Among the four groups, there were significant differences in baseline characteristics (age, body mass index [BMI], cause of end-stage renal disease [ESRD], number of kidney transplantations, and use of induction agent). The mean modification of diet in renal disease (MDRD) glomerular filtration rate (GFR) level at 1 month, 6 months, 1 year, 3 years, and 5 years after transplantation was significantly lower in patients with ECDs but MDRD GFR level at 7, 9, and 10 years did not differ significantly (P = .183, .041, and .388, respectively). There were no significant differences in graft survival (P = .400) and patient survival (P = .147). CONCLUSION: Our result shows that, regardless of recipient age, kidney transplants donated by deceased ECDs have similar graft and patient survival.

Second and third kidney transplantations.

We reviewed the results of second and third kidney transplantations at our center. Among 1500 patients who had undergone kidney transplantation from 1968 to October 2005, we discovered 77 (male 55 and female 22 of overall mean age = 48.9 years) second transplantations and 5 (male 4, female 1; mean age = 46.8 years) third transplantations. The 82 kidneys were derived from living donors in 67 patients and from cadaveric donors in 15 patients. The mean duration from the first to the second transplantation was 89 months, and from the second to the third transplantation, 32.7 months. Among the second and third transplantations and graft nephrectomies, we failed to observe additional surgical complications compared with first transplants and over 80% graft survival at 1 year.