Heat-Dissipation Design and 3D Printing of Ternary Silver Chalcogenide-Based Thermoelectric Legs for Enhancing Power Generation Performance.

Thermoelectric devices have received significant attention because of their potential for sustainable energy recovery. In these devices, a thermal design that optimizes heat transfer and dissipation is crucial for maximizing the power output. Heat dissipation generally requires external active or passive cooling devices, which often suffer from inevitable heat loss and heavy systems. Herein, the design of heat-sink integrated thermoelectric legs is proposed to enhance heat dissipation without external cooling devices, realized by finite element model simulation and 3D printing of ternary silver chalcogenide-based thermoelectric materials. Owing to the self-induced surface charges of the synthesized AgBiSe2 (n-type) and AgSbTe2 (p-type) particles, these particle-based colloidal inks exhibited high viscoelasticity, which enables the creation of complex heat-dissipation architectures via 3D printing. Power generators made from 3D-printed heat-dissipating legs exhibit higher temperature differences and output power than traditional cuboids, offering a new strategy for enhancing thermoelectric power generation.

A Multicenter, Randomized, Open-Label Study to Compare the Efficacy and Safety of Tacrolimus and Corticosteroids in Combination With or Without Mycophenolate Mofetil in Liver Transplantation Recipients Infected With Hepatitis B Virus.

BACKGROUND: Mycophenolate mofetil exhibits pharmacologic mechanisms different from calcineurin inhibitors. Therefore, the dose of calcineurin inhibitors can be reduced along with side effects for effective immunosuppression. We aimed to evaluate the efficacy and safety of tacrolimus and corticosteroid in combination with or without mycophenolate mofetil in living donor liver transplantation (LDLT) recipients infected with hepatitis B virus (HBV). METHODS: A randomized, open-label, comparative, multicenter, phase IV study was conducted with 119 patients from January 2014 to September 2017. In the full analysis set population, 58 and 59 patients were included in the study group (triple-drug regimen: TacroBell + My-rept + corticosteroid) and the control group (dual-drug regimen: TacroBell + corticosteroid), respectively. In the per protocol set population, 49 and 42 patients were included in the study and control groups, respectively. RESULTS: In the full analysis set population, the incidence of biopsy-proven acute cellular rejection (rejection activity index score ≥4) was 3.4% in the study group; however, this finding was not observed in the control group (P = .468). Hepatitis B virus recurrence was observed in one patient in the control group. No cases of biopsy-proven acute cellular rejection and HBV recurrence were observed in the per protocol set population. The incidences of serious adverse events were 25.9% and 18.0% in the study and control groups, respectively; however, the difference between the groups was not statistically significant (P = .376). CONCLUSION: Although the study involved a small number of patients, the triple-drug regimen can be considered safe and effective for immunosuppression after living donor liver transplantation in patients infected with HBV.

Cu2Se-based thermoelectric cellular architectures for efficient and durable power generation.

Thermoelectric power generation offers a promising way to recover waste heat. The geometrical design of thermoelectric legs in modules is important to ensure sustainable power generation but cannot be easily achieved by traditional fabrication processes. Herein, we propose the design of cellular thermoelectric architectures for efficient and durable power generation, realized by the extrusion-based 3D printing process of Cu2Se thermoelectric materials. We design the optimum aspect ratio of a cuboid thermoelectric leg to maximize the power output and extend this design to the mechanically stiff cellular architectures of hollow hexagonal column- and honeycomb-based thermoelectric legs. Moreover, we develop organic binder-free Cu2Se-based 3D-printing inks with desirable viscoelasticity, tailored with an additive of inorganic Se82- polyanion, fabricating the designed topologies. The computational simulation and experimental measurement demonstrate the superior power output and mechanical stiffness of the proposed cellular thermoelectric architectures to other designs, unveiling the importance of topological designs of thermoelectric legs toward higher power and longer durability.

Primary malignant mesothelioma developed in liver.

The following reports a rare case of primary localized malignant mesothelioma of the liver. A 53-year-old man with no history of exposure to asbestos was admitted to our department for evaluation of incidentally detected liver mass. Computed tomography and hepatic angiogram showed a tumor at the dome of the liver, which was fed mainly through the inferior phrenic artery. The mass was resected, including a portion of the diaphragm. Microscopically, the tumor was composed of cord-like or trabecular arrangements of epithelioid cells having abundant eosinophilic cytoplasm and prominent nucleoli. Immunohistochemically, the tumor cells were strongly positive for calretinin and cytokeratin 5 and negative for hepatocyte markers. These findings were consistent with our diagnosis of epithelioid mesothelioma. A local recurrence was noted 15 months after surgery, which was treated by radiofrequency ablation. At 23 months after initial surgery, locally recurrent masses with direct invasion of the diaphragm and a solitary intrahepatic metastasis were noted, which was treated by partial excision of the diaphragm with intraoperative RFA after transarterial chemoembolization.

Hepatic vein anatomy of the medial segment for living donor liver transplantation using extended right lobe graft.

Hepatic vein anatomy (V4) of the medial segment (S4) has been a matter of concern since introduction of extended right lobe (ERL) graft. To assess risk of hepatic venous congestion (HVC) in ERL donors, we tried to newly classify V4 anatomy. We analyzed V4 anatomy of 328 living donor livers by using 3-dimensional reconstruction (3-DR) and volumetry of computed tomography (CT). Variations of V4 were divided into type A (middle hepatic vein [MHV] dominant: n = 142, 43.3%), type B (MHV-dominant, but enabling preservation of dorsal V4 branch [V4b]: n = 40, 12.2%), type C (mixed: n = 92, 28%), and type D (left hepatic vein dominant: n = 54, 16.5%). We analyzed the amount of HVC at S4 in 143 donor livers of right lobe (RL) and ERL grafts. Occlusion of MHV trunk induced HVC equivalent to 85.2%, 85.4%, 55.2%, and 35.4% of S4 volume and 34%, 33.9%, 20.3%, and 14.2% of left liver volume in livers of types A, B, C, and D, respectively. Tailored V4b preservation reduced HVC significantly in type B livers. Considering that functional capability may be decreased in HVC portion, functional hepatic resection rate (FHRR) of ERL graft procurement ranged as follows: 62.3%-75% in type A; 62.2%-75% and 62.2%-68.7% in type B with and without V4b preservation, respectively; 63.2%-70.7% in type C; and 61.8%-67.2% in type D. These results support the theory that these categories of V4 types are closely correlated with potential amount of HVC at S4, reflect the possibility of V4b preservation, and are compatible with CT findings. We believe that this V4 classification is applicable to assess donor V4 anatomy in practice.

Simplified standardized technique for living donor liver transplantation using left liver graft plus caudate lobe.

Concomitant resection of the caudate lobe (CL) would increase the liver mass in the left liver graft. We tried to define a simplified standardized technique for adult living donor liver transplantation using the extended left lobe (ELL) plus CL (ELLC) through a prospective study of 27 consecutive ELLC graft cases in 2003. Donor CL was dissected toward the 10 o'clock direction and transected at the midpoint between the trunks of the right hepatic vein (RHV) and the middle hepatic vein (MHV). This orthodox transection was performed in 18 cases, but the transection plane was moved left in 9 cases. Compared with conventional left liver implantation, there was no additional reconstruction except for single revascularization of the largest short hepatic vein of the CL (V1) in 21 cases. On 1-week computed tomography (CT) images, the perfusion states of the CL portion were good in 15 cases, fair in 7 cases, and poor in 5 cases. Regeneration of the CL portion during the 1st week was +43%, +18%, and -10% in the good, fair, and poor perfusion groups, respectively. There were positive correlations among the perfusion state of the CL, the location of the CL transection plane, and the width of the CL portion that was attached to the left liver graft. CL implantation resulted in a mean gain of graft mass by 5.9% in the left liver at the time of operation and by 3.9% after 1 week. There were no donor complications, and 25 recipients (93%) survive to date. In conclusion, this simplified standardized technique was feasible for most of the living donor livers and required only 1 additional reconstruction of the V1.

Donor selection for procurement of right posterior segment graft in living donor liver transplantation.

The right posterior segment (RPS) graft was introduced to overcome graft-size mismatch when the donor liver demonstrates a disproportionately small left lobe (LL). As variants of liver anatomy seemed to be related to the feasibility of RPS graft procurement, in 2003, we performed a prospective study to assess its feasibility in 197 consecutive living donors. Variants of the portal vein (PV) were classified as type I (bifurcation), II (trifurcation), and III (independent RPS PV branching from main PV). The right hepatic artery, vein, and bile duct were also classified according to their branching pattern and location. PV variations were type I in 157 (79.7%) donors, type II in 15 (7.6%) donors, and type III in 25 (12.7%) donors. Mean volume proportion of LL plus caudate lobe was 35.3 +/- 3.8% (range 24-4) of the whole liver volume (WLV). On exclusion of donors with LL greater than 35% of WLV, there were 14 (7.1%) donors revealing RPS greater than LL by over 3% of WLV. Of these 14 donors, 3 had type I PV with artery or bile duct anatomy not suitable for RPS procurement. One donor with type II PV and 9 out of 10 donors with type III PV met the anatomical conditions for RPS graft procurement. With the exclusion of caudate lobe volume, LL volume became less than 30% of WLV in all of these 14 donors. We successfully procured 3 RPS grafts, all with type III PV, out of 197 consecutive living donors. In conclusion, successful RPS graft procurement is highly possible, only when LL is disproportionately small (<30% of WLV) and the PV variant is type III.

Umbilical portion of recipient's left portal vein: a useful vascular conduit in dual living donor liver transplantation for the thrombosed portal vein.

We considered performing living donor liver transplantation (LDLT) in a larger-size recipient. When the recipient was large-sized, or when the donor liver was severely steatotic or had a right-to-left volume discrepancy. We devised dual living donor liver transplantation (DLDLT) to make up for graft size insufficiency and to secure the donor's safety. However, portal vein thrombosis (PVT) presented a challenge for DLDLT because of the need for intact right and left portal veins for the implantation of both liver grafts. Our 52-year-old male patient with hepatitis B cirrhosis had suffered from repeated esophageal and gastric variceal bleeding and underwent 2 trials of a transjugular intrahepatic portosystemic shunt (TIPS). He developed TIPS occlusion and PVT involving the area just above the spleno-mesenteric confluence to the right and left PV. Also, the right PV orifice was destructed and difficult to isolate because of severe periportal inflammation and neointima growth in the TIPS mesh. The patient's two sons were inadequate for donation because of right-to-left volume discrepancy. Therefore, DLDLT using 2 left lobes was necessary to compensate for graft-size insufficiency and to secure donor safety, and we substituted an intact umbilical portion of recipient's left PV for the destroyed right PV. The patient recovered well, and liver function has been normal for more than a year. In conclusion, the umbilical portion of recipient's left PV can be a useful vascular substitute for the reconstruction of a thrombosed main portal branch in DLDLT.