Hierarchical PtCuMnP Nanoalloy for Efficient Hydrogen Evolution and Methanol Oxidation

The higher amount of Pt usage and its poisoning in methanol oxidation reaction in acidic media is a major setback for methanol fuel cells. Herein, a promising dual application high-performance electrocatalyst has been developed for hydrogen evolution and methanol oxidation. A low Pt-content nanoalloy co-doped with Cu, Mn, and P is synthesized using a modified solvothermal process. Initially, ultrasmall ≈2.9 nm PtCuMnP nanoalloy is prepared on N-doped graphene-oxide support and subsequently, it is characterized using several analytical techniques and examined through electrochemical tests. Electrochemical results show that PtCuMnP/N-rGO has a low overpotential of 6.5 mV at 10 mA cm-2 in 0.3 m H2 SO4 and high mass activity for the hydrogen evolution reaction. For the methanol oxidation reaction, the PtCuMnP/N-rGO electrocatalyst exhibits robust performance. The mass activity of PtCuMnP/N-rGO is 6.790 mA mg-1 Pt , which is 7.43 times higher than that of commercial Pt/C (20% Pt). Moreover, in the chronoamperometry test, PtCuMnP/N-rGO shows exceptionally good stability and retains 72% of the initial current density even after 20,000 cycles. Furthermore, the PtCuMnP/N-rGO electrocatalyst exhibits outstanding performance for hydrogen evolution and methanol oxidation along with excellent anti-poisoning ability. Hence, the developed bifunctional electrocatalyst can be used efficiently for hydrogen evolution and methanol oxidation.

High Entropy Pr-Doped Hollow NiFeP Nanoflowers Inlaid on N-rGO for Efficient and Durable Electrodes for Lithium-Ion Batteries and Direct Borohydride Fuel Cells

The selection and design of new electrode materials for energy conversion and storage are critical for improved performance, cost reduction, and mass manufacturing. A bifunctional anode with high catalytic activity and extended cycle stability is crucial for rechargeable lithium-ion batteries and direct borohydride fuel cells. Herein, a high entropy novel three-dimensional structured electrode with Pr-doped hollow NiFeP nanoflowers inlaid on N-rGO was prepared via a simple hydrothermal and self-assembly process. For optimization of Pr content, three (0.1, 0.5, and 0.8) different doping ratios were investigated. A lithium-ion battery assembled with NiPr0.5 FeP/N-rGO electrode achieved an outstanding specific capacity of 1.61 Ah g-1 at 0.2 A g-1 after 100 cycles with 99.3 % Coulombic efficiencies. A prolonged cycling stability of 1.02 Ah g-1 was maintained even after 1000 cycles at 0.5 A g-1 . In addition, a full cell battery with NiPr0.5 FeP/N-rGO∥LCO (Lithium cobalt oxide) delivered a promising cycling performance of 0.52 Ah g-1 after 200 cycles at 0.15 A g-1 . Subsequently, the NiPr0.5 FeP/N-rGO electrode in a direct borohydride fuel cell showed the highest peak power density of 93.70 mW cm-2 at 60 °C. Therefore, this work can be extended to develop advanced electrode for next-generation energy storage and conversion systems.

Enhanced Thermal Stability and Conductivity of FeF3 Using Ni-Coated Carbon Composites: Application as High-Temperature Cathodes in Thermal Batteries

Cathode active materials and conductive additives for thermal batteries operating at high temperatures have attracted research interest, with a particular focus on compounds offering high thermal stability. Recently, FeF3 has been proposed as a candidate for high-voltage cathode materials; however, its commercialization is hindered by its low conductivity. In this study, conductive additives, such as Ni-coated carbon composites (multi-walled carbon nanotubes (MWCNTs) and carbon black (CB)), were utilized to enhance the thermal stability and conductivity of FeF3. The incorporation of metal-carbon conductive additives in the FeF3 composite increased the thermal stability by more than 10 wt.% and ensured high capacity upon conductivity enhancement. The FeF3@Ni/MWCB 15 wt.% composite containing 30 wt.% Ni exhibited a discharge capacity of ∼86% of the theoretical capacity of 712 mAh/g. The use of Ni-coated carbon-based conductive additives will allow the application of FeF3 as an effective high-temperature cathode material for thermal batteries.

FeF3/(Acetylene Black and Multi-Walled Carbon Nanotube) Composite for Cathode Active Material of Thermal Battery through Formation of Conductive Network Channels

Considerable research is being conducted on the use of FeF3 as a cathode replacement for FeS2 in thermal batteries. However, FeF3 alone is inefficient as a cathode active material because of its low electrical conductivity due to its wide bandgap (5.96 eV). Herein, acetylene black and multi-walled carbon nanotubes (MWCNTs) were combined with FeF3, and the ratio was optimized. When acetylene black and MWCNTs were added separately to FeF3, the electrical conductivity increased, but the mechanical strength decreased. When acetylene black and MWCNTs were both added to FeF3, the FeF3/M1AB4 sample (with 1 wt.% MWCNTs and 4% AB) afforded a discharge capacity of approximately 74% of the theoretical capacity (712 mAh/g) of FeF3. Considering the electrical conductivity and mechanical strength, this composition was confirmed to be the most suitable.

Development of A 14.8-MEV Mono-Energetic Neutron Field in Korea Research Institute of Standards and Science

A standard irradiation field for 14.8-MeV neutrons is under development for mono-energetic neutron standards research in the Korea Research Institute of Standards and Science, Republic of Korea. We developed a target chamber with the associated alpha particle (AAP) system for 14.8-MeV mono-energetic neutrons by a T(d,n)4He reaction. We designed the target chamber and the AAP detector system using a two-body kinematic calculation. We conducted simulations of the T(d,n)4He reaction on a tritiated target to determine a specification of the target and the AAP detector. This paper will discuss the simulation and calculation results for the associated particle system design.

Frontal peripheral osteomas: a retrospective study

BACKGROUND

Osteomas are benign, slow-growing bone tumors that can be classified as central, peripheral, or extraskeletal. Central osteomas arise from the endosteum, peripheral osteomas from the periosteum, and extraskeletal osteomas within the muscle. Frontal peripheral osteomas are mainly encountered in plastic surgery. In this study, we retrospectively analyzed the clinical data of patients with frontal peripheral osteomas.

METHODS

We retrospectively reviewed the medical records of patients who visited our hospital with frontal peripheral osteomas between January 2014 and June 2022. We analyzed the following variables: age, sex, tumor type (sessile or pedunculated), single or multiple, size, history of head trauma, operation, and recurrence.

RESULTS

A total of 39 patients and 41 osteomas were analyzed, of which 29 osteomas (71%) were sessile and 12 osteomas (29%) were pedunculated. The size of the osteomas ranged from 4 to 30 mm, with an average size of 10 mm. The age of patients ranged from 4 to 78 years with a mean age of 52 years. There were seven men (18%) and 32 women (82%), and the man-to-woman ratio was 1:4.6. Two patients (5%) had multiple masses, with two osteomas in each, while only two patients (5%) had a history of head trauma. Twenty-nine patients (74%) underwent ostectomy by a direct approach, and none of the patients experienced recurrence.

CONCLUSION

The epidemiologic data of our study will help plastic surgeons encounter frontal peripheral osteomas in the field to provide proper management for their patients.

Anion Exchange Membranes for Fuel Cell Application: A Review

The fuel cell industry is the most promising industry in terms of the advancement of clean and safe technologies for sustainable energy generation. The polymer electrolyte membrane fuel cell is divided into two parts: anion exchange membrane fuel cells (AEMFCs) and proton exchange membrane fuel cells (PEMFCs). In the case of PEMFCs, high-power density was secured and research and development for commercialization have made significant progress. However, there are technical limitations and high-cost issues for the use of precious metal catalysts including Pt, the durability of catalysts, bipolar plates, and membranes, and the use of hydrogen to ensure system stability. On the contrary, AEMFCs have been used as low-platinum or non-platinum catalysts and have a low activation energy of oxygen reduction reaction, so many studies have been conducted to find alternatives to overcome the problems of PEMFCs in the last decade. At the core of ensuring the power density of AEMFCs is the anion exchange membrane (AEM) which is less durable and less conductive than the cation exchange membrane. AEMFCs are a promising technology that can solve the high-cost problem of PEMFCs that have reached technological saturation and overcome technical limitations. This review focuses on the various aspects of AEMs for AEMFCs application.

Ni-Fe phosphide deposited carbon felt as free-standing bifunctional catalyst electrode for urea electrolysis

A free-standing catalyst electrode for the urea oxidation reaction (UOR) and hydrogen evolution reaction (HER) in a urea electrolysis cell was synthesized by electroplating a Ni-Fe alloy onto carbon felt, followed by phosphidation (P-NiFe@CF). The prepared P-NiFe@CF catalyst consisted of Ni5P4, NiP2, and FeP with 3D flower-like P-NiFe architecture on CF. P-NiFe@CF exhibited excellent electrocatalytic activity for the UOR (demanding only 1.39 V (vs. RHE) to achieve 200 mA cm-2), and for the HER with a low overpotential of 0.023 V (vs. RHE) at 10 mA cm-2, indicating its feasibility as a bifunctional catalyst electrode for urea electrolysis. A urea electrolysis cell with P-NiFe@CF as both the free-standing anode and cathode generated a current density of 10 mA cm-2 at a cell potential of 1.37 V (vs. RHE), which is considerably lower than that of water electrolysis, and also lower than previously reported values. The results indicate that the P-NiFe@CF catalyst electrodes can be used as free-standing bifunctional electrodes for urea electrolyzers.

Effects of low-level laser therapy and adipose-derived stem cells on the viability of autologous fat grafts: a preliminary study

Background Autologous fat grafts are commonly used in cosmetic and reconstructive surgery, and various methods are used to improve their viability. Low-level laser therapy (LLLT) can enhance the proliferation, growth, and differentiation of various cell lines, including stem cells. Our study investigated and compared the effects of LLLT and the addition of adipose-derived stem cells (ADSCs) on the viability of fat grafts.Methods Twenty nude mice were divided into four groups: control (group 1), LLLT irradiation (group 2), ADSC addition (group 3), and LLLT irradiation+ADSC addition (group 4). ADSCs were combined with the fat tissue. LLLT irradiation was performed once daily for 1 week from the day of grafting. After 8 weeks, the weight, volume, histology, and Western blot findings of the grafted fat tissues were evaluated.Results The retention rate and volume of the fat tissue in groups 2, 3, and 4 were higher than that of group 1, but the difference was not statistically significant. The number of capillaries, histological parameters, and immunofluorescence staining analyses for CD68, CD31, fibroblast growth factor, and vascular endothelial growth factor (VEGF) showed no significant differences among the four groups. The expression level of VEGF was higher in group 2 than in the other groups, but not to a statistically significant level.Conclusions LLLT and ADSCs did not significantly improve the viability of autologous fat grafts. Therefore, further study is necessary to develop safe and effective methods to improve the viability of these grafts for clinical application.

Effects of COVID-2019 on plastic surgery emergencies in Korea

Background

To fight the coronavirus disease 2019 (COVID-19) pandemic, many countries have implemented social distancing and lockdowns. We investigated the changes in the trauma patterns of emergency plastic surgeries in the midst of a pandemic.

Methods

A retrospective review of the medical records of all patients treated for emergency plastic surgeries was performed at our hospital in Seoul. We conducted the analysis between March 1 and June 30, 2020, and compared the data obtained with that of the same period in 2019. We also investigated changes in trauma patterns according to the social distancing level from July 2020 to February 2021.

Results

There was a total of 800 emergency plastic surgery patients from March to June 2020, which was less than the 981 in the corresponding period in 2019. The proportion of patients aged 7–17 years and ≥80 in 2020 showed a significant decrease. In 2020, patients presenting with facial trauma decreased and hand trauma, markedly laceration, increased significantly. In 2020, more injuries happened at home, whereas significantly fewer injuries happened on the streets. In 2020, slipping and sports injury decreased, whereas penetrating injury increased significantly. In the changes observed according to the social distancing level, there were significant differences in age classification, facial open wound, and the mechanism of injury.

Conclusion

Social distancing has caused a change in emergency plastic surgeries. To ensure safe and appropriate treatment, strict epidemiologic workup and protective equipment are required.

Enhanced Electrochemical Properties of Catalyst by Phosphorous Addition for Direct Urea Fuel Cell

An anode bimetallic catalyst comprising Ni-Pd alloy nanoparticles was loaded on acid-treated multi-walled carbon nanotubes (MWCNTs) for application in a direct urea fuel cell. The bimetallic catalyst and MWCNTs were synthesized by a hydrothermal method at 160°C for 5 h. To reduce the catalyst particle size, alkaline resistance, and facilitate their uniform distribution on the surface of the MWCNTs, phosphorus (P) was added to the Ni-Pd/MWCNT catalyst. The effects of P on the distribution and reduction in size of catalyst particles were investigated by Brunauer-Emmett-Teller analysis, transmission electron microscopy, and X-ray diffraction analysis. The enhanced catalytic activity and durability of the P-containing catalyst was confirmed by the high current density [1897.76 mA/cm2 (vs. Ag/AgCl)] obtained at 0.45 V in a 3 M KOH/1.0 M urea alkaline aqueous solution compared with that of the catalyst without P [604.87 mA/cm2 (vs. Ag/AgCl)], as determined by cyclic voltammetry and chronoamperometry. A Urea-O2 fuel cell assembled with a membrane electrode assembly comprising the Ni-Pd(P)/MWCNT catalyst delivered peak power densities of 0.756 and 3.825 mW/cm2 at 25 and 60°C, respectively, in a 3 M KOH/1 M urea solution.

Synthesis of Mn-, Ni-Doped LiAlO₂ Matrix for Molten Carbonate Fuel Cell

The phase stability of electrolyte matrix was improved by metal dopant materials which are Ni and Mn. The Ni-, Mn-doped LiAlO₂ and dopant-free LiAlO₂ were prepared by the mechanochemical process (MCP). The effects of dopant material, molar ratio and type of precursor were investigated after heat treatment at 700 and 800 °C. As a results, the Mn-doped LiAlO₂ prevents phase transition even at higher operating temperature. Also, the stability was increased when Mn⁴⁺ ion was adapted as a precursor source than Mn³⁺ ion and the minimum Mn content to maintain the α-phase after heat treatment at 800 °C is found to be LiA_l0.75Mn_0.25O₂. This result suggested that the formation of nano-sized particles confirmed the applicability as a matrix material with excellent electrolyte impregnation.

Binder-Free Cathode for Thermal Batteries Fabricated Using FeS2 Treated Metal Foam

In this study, we fabricated a cathode with lower amounts of additive materials and higher amounts of active materials than those of a conventional cathode. A thermal battery was fabricated using FeS₂ treated foam as the cathode frame, and its feasibility was verified. X-ray diffraction, transmission electron microscopy, and scanning electron microscopy were used to analyze the effects of thermal sulfidation temperature (400 and 500°C) on the structure and surface morphology of the FeS₂ foam. The optimal temperature for the fabrication of the FeS_x treated foam was determined to be 500°C. The FeS₂ treated foam reduced the interfacial resistance and improved the mechanical strength of the cathode. The discharge capacity of the thermal battery using the FeS₂ treated foam was about 1.3 times higher than that of a thermal battery using pure Fe metal foam.

Two-Dimensional Vanadium Carbide MXene for Gas Sensors with Ultrahigh Sensitivity Toward Nonpolar Gases

The sensitive detection of explosive and flammable gases is an extremely important safety consideration in today's industry. Identification of trace amounts of nonpolar analytes at ambient temperatures, however, is still a challenge because of their weak adsorption, and very few studies have been able to achieve it via a chemiresistive mechanism. Herein, we demonstrate the high performance of 2D vanadium carbide MXene (V₂CT _x) gas sensors with ultrahigh sensitivity toward nonpolar gases. The fabricated 2D V₂CT _x sensor devices consisting of single-/few-layer 2D V₂CT _x on polyimide film were able to detect both polar and nonpolar chemical species including hydrogen and methane with a very low limit of detection of 2 and 25 ppm, respectively, at room temperature (23 °C). The performance of the fabricated V₂CT _x gas sensors in detection of nonpolar gases surpasses that of previously reported state-of-the-art gas sensors based on other 2D materials.

Two-Dimensional Transition Metal Dichalcogenides and Metal Oxide Hybrids for Gas Sensing

Two-dimensional (2D) nanomaterials have demonstrated great potential in the field of gas sensing due to their layered structures. Especially for 2D transition metal dichalcogenides (TMDs), inherent high surface areas and their unique semiconducting properties with tunable band gaps make them compelling for sensing applications. In combination with the general benefits of 2D nanomaterials, the incorporation of metal oxides into 2D TMDs is a recent approach for improving the gas sensing performance of these materials by the synergistic effects of the hybridization. This Review aims to comprehend the sensing mechanisms and the synergistic effects of various hybridizations of 2D TMDs and metal oxides. The Review begins with the gas sensing mechanisms and synthesis methods of 2D TMDs. Achievements in recent research on 2D TMDs and their metal oxide hybrids for sensor applications are then comprehensively compiled. To clearly understand the collective benefits of TMDs and metal oxide hybrids, the hybridization effects are discussed in three aspects: geometrical, electronic, and chemical effects.

Enhanced Gas-Sensing Performance of GO/TiO₂ Composite by Photocatalysis

Few studies have investigated the gas-sensing properties of graphene oxide/titanium dioxide (GO/TiO₂) composite combined with photocatalytic effect. Room temperature gas-sensing properties of the GO/TiO₂ composite were investigated towards various reducing gases. The composite sensor showed an enhanced gas response and a faster recovery time than a pure GO sensor due to the synergistic effect of the hybridization, such as creation of a hetero-junction at the interface and modulation of charge carrier density. However, the issue of long-term stability at room temperature still remains unsolved even after construction of a composite structure. To address this issue, the surface and hetero-junction of the GO/TiO₂ composite were engineered via a UV process. A photocatalytic effect of TiO₂ induced the reduction of the GO phase in the composite solution. The comparison of gas-sensing properties before and after the UV process clearly showed the transition from n-type to p-type gas-sensing behavior toward reducing gases. This transition revealed that the dominant sensing material is GO, and TiO₂ enhanced the gas reaction by providing more reactive sites. With a UV-treated composite sensor, the function of identifying target gas was maintained over a one-month period, showing strong resistance to humidity.

Effect of maternally derived antibody on sequential infection with highly virulent bursal disease virus in newly hatched broilers

Maternally derived antibodies (MDAs) are important for protection against very virulent infectious bursal disease virus (vvIBDV). In this study, 5-day-old commercial broilers with non-uniform MDA titers (with a coefficient of variation of 50%) were challenged with vvIBDV and given free contact with each other during a 2-week period. The chicks were assigned to four MDA-titer subgroups, GI-1 (very low MDA), GI-2 (low MDA), GI-3 (medium MDA), and GI-4 (high MDA). Transient symptoms of infection were observed in 35.7% of challenged birds. Body weight gain was significantly lower in GI-2, GI-3, and GI-4 birds than in an unchallenged control group. Seroconversion was observed in GI-1 birds and some GI-2 birds. The frequency of virus shedding via the cloaca in vvIBDV-challenged birds increased from 7.1% of GI birds at 5 days post inoculation (dpi) to 35.7% at 14 dpi. The timing of virus shedding was progressively later from GI-1 to GI-4. At 14 dpi, significant atrophy of the bursa of Fabricius (BF) was observed in GI birds compared with GII controls; atrophy was most severe in GI-1 birds and least severe in GI-4 birds. BF lesion scores decreased from GI-1 to GI-4. The proportion of birds with IBDV antigen in the BF at 14 dpi was higher in GI-2 and GI-3 than in GI-1 and GI-4, whereas the viral load in positive birds increased from GI-1 to GI-4. Our results indicate that high levels of MDAs would protect chicks from initial vvIBDV infection but that progressive decay of these MDAs would result in delayed infection by virus shedding in initially infected birds with low MDA titers, resulting in continuous circulation of the virus in a flock with non-uniform MDA titers.

Data on fuel cell performance of Nafion® based hybrid composite membrane containing GO and dihydrogen phosphate functionalized ionic liquid at 70 °C under anhydrous condition

This data provides the fuel cell performance of Nafion based hybrid membranes containing GO and dihydrogen phosphate functionalized ionic liquid (IL) at 70 °C under anhydrous condition. Readers are requested to go through the article entitled "Nafion® based hybrid composite membrane containing GO and dihydrogen phosphate functionalized ionic liquid for high temperature polymer electrolyte membrane fuel cell" (Maiti et al., 2017) [1] for further interpretation and discussion.

Nanomatrix Coated Stent Enhances Endothelialization but Reduces Platelet, Smooth Muscle Cell, and Monocyte Adhesion under Physiologic Conditions

Cardiovascular disease is presently the number one cause of death worldwide. Current stents used to treat cardiovascular disease have a litany of unacceptable shortcomings: adverse clinical events including restenosis, neointimal hyperplasia, thrombosis, inflammation, and poor re-endothelialization. We have developed a biocompatible, multifunctional, peptide amphiphile-based nanomatrix coating for stents. In this study, we evaluated the ability of the nanomatrix coated stent to simultaneously address the issues facing current stents under physiological flow conditions in vitro. We found that the nanomatrix coated stent could increase endothelial cell migration, adhesion, and proliferation (potential for re-endothelialization), discourage smooth muscle cell migration and adhesion (potential to reduce neointimal hyperplasia and restenosis), and decrease both platelet activation and adhesion (potential to prevent thrombosis) as well as monocyte adhesion (potential to attenuate inflammatory responses) under physiological flow conditions in vitro. These promising results demonstrate the potential clinical utility of this nanomatrix stent coating, and highlight the importance of biocompatibility, multifunctionality, and bioactivity in cardiovascular device design.

Room Temperature Gas Sensing of Two-Dimensional Titanium Carbide (MXene)

Wearable gas sensors have received lots of attention for diagnostic and monitoring applications, and two-dimensional (2D) materials can provide a promising platform for fabricating gas sensors that can operate at room temperature. In the present study, the room temperature gas-sensing performance of Ti₃C₂T_x nanosheets was investigated. 2D Ti₃C₂T_x (MXene) sheets were synthesized by removal of Al atoms from Ti₃AlC₂ (MAX phases) and were integrated on flexible polyimide platforms with a simple solution casting method. The Ti₃C₂T_x sensors successfully measured ethanol, methanol, acetone, and ammonia gas at room temperature and showed a p-type sensing behavior. The fabricated sensors showed their highest and lowest response toward ammonia and acetone gas, respectively. The limit of detection of acetone gas was theoretically calculated to be about 9.27 ppm, presenting better performance compared to other 2D material-based sensors. The sensing mechanism was proposed in terms of the interactions between the majority charge carriers of Ti₃C₂T_x and gas species.

A probiotic combination attenuates experimental colitis through inhibition of innate cytokine production

Inflammatory bowel disease (IBD) is a severe immune cell-mediated syndrome characterised by extensive inflammatory and effector mucosal responses leading to tissue destruction in the colon and small intestine. The leading hypothesis is that dysbiosis of the gut flora causes an excessive immune response and inflammation in the gastrointestinal track. Lactic acid bacteria (LAB) can correct dysbiosis of the normal microbiota. In the current study, the therapeutic potential of seven LAB strains in combination to treat IBD was evaluated using experimental colitis model. This LAB cocktail, designated GI7, includes four strains of Lactobacillus acidophilus, Lactobacillus plantarum, Lactobacillus rhamnosus, Lactococcus lactis, two strains of Bifidobacterium bifidum, Bifidobacterium breve, and one strain of Streptococcus thermophilus. We confirmed that GI7 suppressed pro-inflammatory cytokines in Raw264.7 macrophages. When dextran sulphate sodium-induced colitic mice were treated with GI7, their symptoms of colitis, as assessed by body weight, colon length, myeloperoxidase activity, intestinal bleeding, and histological damage, were reduced compared to untreated mice. In addition, GI7 treatment significantly inhibited the production of innate pro-inflammatory cytokines during colitic progression. Therefore, we suggest that GI7, a combination of seven LAB, has a potential role in the treatment of IBD.

Late anastomotic leakage after low anterior resection in rectal cancer patients: clinical characteristics and predisposing factors

AIM

The purpose was to examine the clinical characteristics and predisposing factors of late anastomotic leakage following low anterior resection for rectal cancer.

METHOD

We retrospectively evaluated the clinicopathological features of patients who experienced anastomotic leakage after low anterior resection for rectal cancer. Patients were divided into two groups according to the time to leakage: early leakage (within 30 days postoperatively) and late leakage (after 30 days postoperatively). Clinicopathological characteristics were compared between the two groups.

RESULTS

Anastomotic leakage occurred in 141 patients. Anastomotic leakage was diagnosed at a median of 17 (range 0-886) days postoperatively; 85 (60.3%) and 56 (39.7%) were categorized as the early and late leakage groups, respectively. Radiotherapy (hazard ratio 5.007; 95% CI 2.208-11.354; P < 0.0001) was the only significant independent predisposing factor for late leakage. Diverting stoma did not protect against late leakage. The late leakage group more frequently had the fistula type (46.4% vs. 10.6%; P < 0.001) and less frequently needed laparotomy (55.4% vs. 78.8%; P = 0.001). The rate of long-term stoma over 1 year was greater in the late leakage than the early leakage group (51.8% vs. 29.4%; P = 0.009).

CONCLUSION

Late anastomotic leakages that develop after 30 days following low anterior resection are not uncommon and may be associated with the use of radiotherapy. Late leakage should be a different entity from early leakage in terms of the type of leakage, methods of management and subsequent sequelae.

Hollow Nanobarrels of α-Fe2O3 on Reduced Graphene Oxide as High-Performance Anode for Lithium-Ion Batteries

Alpha-phase iron oxide nanoparticles (α-NPs), α-iron oxide hollow nanobarrels (α-HNBs), and α-HNBs on reduced graphene oxide (α-HNBs/RGO) for Li-ion batteries (LIBs) were synthesized by a time-efficient microwave method to improve the low electrical conductivity of iron oxide and exploit the porous structure of RGO, which prevents the volume expansion of α-Fe2O3 during the insertion/extraction. On the other hand, α-HNBs (∼200 nm in diameter, ∼360 nm in length) provide a short diffusion path for Li ions and accommodate the strain generated by the volume change. The α-HNBs/RGO hybrid structure was synthesized by a one-step microwave-assisted hydrothermal method to bond α-HNBs with RGO. The as-prepared α-HNBs/RGO electrode exhibited a superior reversible capacity of 1279 mA h g(-1) at 0.5 C after the first cycle; such a capacity was nearly recovered after numerous cycles (2nd to 100th cycle, 95%). The long-term cyclability of α-HNBs/RGO shows 478 mA h g(-1) after 1000 cycles. Moreover, the α-HNBs/RGO electrode shows a high rate capacity of 403 mA h g(-1) even at 10 C. The α-HNBs/RGO exhibited a better electrochemical performance that could be attributed to the absence of nanoparticle agglomeration and RGO restacking, which provided a buffer effect against the volume expansion, promoted electrical conductivity and high structural integrity.

Improvement in the amine glass platform by bubbling method for a DNA microarray

A glass platform with high sensitivity for sexually transmitted diseases microarray is described here. An amino-silane-based self-assembled monolayer was coated on the surface of a glass platform using a novel bubbling method. The optimized surface of the glass platform had highly uniform surface modifications using this method, as well as improved hybridization properties with capture probes in the DNA microarray. On the basis of these results, the improved glass platform serves as a highly reliable and optimal material for the DNA microarray. Moreover, in this study, we demonstrated that our glass platform, manufactured by utilizing the bubbling method, had higher uniformity, shorter processing time, lower background signal, and higher spot signal than the platforms manufactured by the general dipping method. The DNA microarray manufactured with a glass platform prepared using bubbling method can be used as a clinical diagnostic tool.

Spotlight on nano-theranostics in South Korea: applications in diagnostics and treatment of diseases

From the synergistic integration and the multidisciplinary strengths of the BioNano Sensor Research Center, Gachon Bionano Research Institute, and Lee Gil Ya Cancer and Diabetes Institute, researchers, students, and faculties at Gachon University in collaboration with other institutions in Korea, Australia, France, America, and Japan have come together to produce a special issue on the diverse applications of nano-theranostics in nanomedicine. This special issue will showcase new research conducted by various scientific groups in Gyonggi-do and Songdo/Incheon, South Korea. The objectives of this special issue are as follows: 1) to bring together and demonstrate some of the latest research results in the field, 2) to introduce new multifunctional nanomaterials and their applications in imaging and detection methods, and 3) to stimulate collaborative interdisciplinary research at both national and international levels in nanomedicine.

Clinical implications of mucinous components correlated with microsatellite instability in patients with colorectal cancer

AIM

Colorectal cancer (CRC) with microsatellite instability (MSI) is characterized by frequent poor differentiation or mucinous histology. The purpose of this study was to evaluate the association of MSI with clinicopathological features and the oncological outcome in patients with a mucinous component.

METHOD

CRC tissue samples were analysed for histology and MSI. Patients were grouped according to the mucinous content of the tumour, as follows: > 50%, mucinous adenocarcinoma (MA); ≤ 50%, adenocarcinoma with mucinous component (AMC); none, nonmucinous adenocarcinoma (NMA). Clinicopathological parameters and survival were compared between patient groups.

RESULTS

Of 2025 patients, 84 (4%) had MA and 124 (6%) had AMC. In addition, 202 (10%) had MSI. Patients with MA and AMC tended to have a younger age of onset, right-colon predilection, large-sized tumour and high frequency of MSI compared with those with NMA (P < 0.001). MA and AMC patients with MSI showed a trend towards right-colon predilection and infrequent lymph-node metastasis compared with those with microsatellite stability (MSS; P = 0.005-0.03). There were no survival differences between the three groups, but patients with MSI-MA demonstrated lower 4-year recurrence and better overall survival rates than those with MSS-MA (P = 0.018 and P = 0.046, respectively).

CONCLUSION

Clinicopathological features of AMC and MA were similar and closely associated with MSI status. Although the prognoses of AMC and MA were no different from that of NMA, survival of patients with an MSI-MA tumour was significantly better than for those with MSS-MA tumours.

Tetrafluoroethane (R134a) hydrate formation within variable volume reactor accompanied by evaporation and condensation

Vast size hydrate formation reactors with fast conversion rate are required for the economic implementation of seawater desalination utilizing gas hydrate technology. The commercial target production rate is order of thousand tons of potable water per day per train. Various heat and mass transfer enhancement schemes including agitation, spraying, and bubbling have been examined to maximize the production capacities in scaled up design of hydrate formation reactors. The present experimental study focused on acquiring basic knowledge needed to design variable volume reactors to produce tetrafluoroethane hydrate slurry. Test vessel was composed of main cavity with fixed volume of 140 ml and auxiliary cavity with variable volume of 0 ∼ 64 ml. Temperatures at multiple locations within vessel and pressure were monitored while visual access was made through front window. Alternating evaporation and condensation induced by cyclic volume change provided agitation due to density differences among water and vapor, liquid and hydrate R134a as well as extended interface area, which improved hydrate formation kinetics coupled with latent heat release and absorption. Influences of coolant temperature, piston stroke/speed, and volume change period on hydrate formation kinetics were investigated. Suggestions of reactor design improvement for future experimental study are also made.

Water soluble sodium sulfate nanorods as a versatile template for the designing of copper sulfide nanotubes

The present study reports the use of water soluble sodium sulfate (Na2SO4) nanorods as a versatile template for generation of tubular copper sulfide (CuS) nanostructures. The Na2SO4 nanorods were synthesized from ammonium sulfate (NH4)2SO4 and sodium hydroxide (NaOH), under refluxing condition. The shape and morphology control of the Na2SO4 nanorods were studied with respect to nature of surfactant used and reactant mole ratio. While, PVP mole ratio was important to obtain homogeneous nanorods. Uniform and stable nanotubes of CuS were than obtained by the dissolution of the nanorods in water. The use of simple chemicals for synthesis of such nanotube templates opens the prospect for wide scale downstream applications.

Gender and age differences in the impact of overweight on obesity-related quality of life among Korean adults

SUMMARY

OBJECTIVE

To investigate gender and age difference in impact of overweight on health-related quality of life (HRQOL) among Korean adults.

METHODS

Cross-sectional obesity-related quality of life (QOL) scores were measured by a Korean obesity-related QOL scale (KOQOL) from 448 Korean adults aged 20-80 years. A body mass index (BMI) was categorized with normal-weight as BMI < 23 kg/m(2), overweight as BMI ≥ 23 kg/m(2) based on the alternative cutoff points for Asians. Each gender was respectively stratified by median age, 45 years for men and 50 years for women, to examine the obesity-related QOL by age groups.

RESULTS

Women had a poorer obesity-related QOL compared to men (p < 0.001). In the younger age group, overweight women had a poorer obesity-related QOL compared with normal-weight women (p < 0.001), however normal-weight and overweight men showed no difference in obesity-related QOL. In the older age group, overweight men showed better QOL on the domains of work-related and psychosocial health than those for normal-weight men, but overweight women still suffered from work-related and routine life QOL.

CONCLUSIONS

This study showed the impact of overweight on obesity-related QOL was different for gender and age group. We should consider the results to manage weight in overweight persons.

Femur-mounted navigation system for the arthroscopic treatment of femoroacetabular impingement

Femoroacetabular impingement stems from an abnormal shape of the acetabulum and proximal femur. It is treated by resection of damaged soft tissue and by the shaping of bone to resemble normal features. The arthroscopic treatment of femoroacetabular impingement has many advantages, including minimal incisions, rapid recovery, and less pain. However, in some cases, revision is needed owing to the insufficient resection of damaged bone from a misreading of the surgical site. The limited view of arthroscopy is the major reason for the complications. In this research, a navigation method for the arthroscopic treatment of femoroacetabular impingement is developed. The proposed navigation system consists of femur attachable measurement device and user interface. The bone mounted measurement devices measure points on head-neck junction for registration and position of surgical instrument. User interface shows the three-dimensional model of patient's femur and surgical instrument position that is tracked by measurement device. Surgeon can know the three-dimensional anatomical structure of hip joint and surgical instrument position on surgical site using navigation system. Surface registration was used to obtain relation between patient's coordinate at the surgical site and coordinate of three-dimensional model of femur. In this research, we evaluated the proposed navigation system using plastic model bone. It is expected that the surgical tool tracking position accuracy will be less than 1 mm.

Non-invasive in situ plasma monitoring of reactive gases using the floating harmonic method for inductively coupled plasma etching application

The floating harmonic method was developed for in situ plasma diagnostics of allowing real time measurement of electron temperature (Te) and ion flux (Jion) without contamination of the probe from surface modification by reactive species. In this study, this novel non-invasive diagnostic system was studied to characterize inductively coupled plasma of reactive gases monitoring Te and Jion for investigating the optimum plasma etching conditions and controlling of the real-time plasma surface reaction in the range of 200-900 W source power, 10-100 W bias power, and 3-15 mTorr chamber pressure, respectively.

Distal metatarsal osteotomy for hallux varus following surgery for hallux valgus

We reviewed the outcome of distal chevron metatarsal osteotomy without tendon transfer in 19 consecutive patients (19 feet) with a hallux varus deformity following surgery for hallux valgus. All patients underwent distal chevron metatarsal osteotomy with medial displacement and a medial closing wedge osteotomy along with a medial capsular release. The mean hallux valgus angle improved from -11.6° pre-operatively to 4.7° postoperatively, the mean first-second intermetatarsal angle improved from -0.3° to 3.3° and the distal metatarsal articular angle from 9.5° to 2.3° and the first metatarsophalangeal joints became congruent post-operatively in all 19 feet. The mean relative length ratio of the metatarsus decreased from 1.01 to 0.99 and the mean American Orthopaedic Foot and Ankle Society score improved from 77 to 95 points. In two patients the hallux varus recurred. One was symptom-free but the other remained symptomatic after a repeat distal chevron osteotomy. There were no other complications. We consider that distal chevron metatarsal osteotomy with a medial wedge osteotomy and medial capsular release is a useful procedure for the correction of hallux varus after surgery for hallux valgus.

Validation of the seventh edition of the American Joint Committee on Cancer tumor-node-metastasis (AJCC TNM) staging in patients with stage II and stage III colorectal carcinoma: analysis of 2511 cases from a medical centre in Korea

AIM

The sixth and seventh editions of the American Joint Committee on Cancer (AJCC) tumor-node-metastasis (TNM) system for patients with stage II and stage III colorectal carcinoma (AJCC-6 and AJCC-7) were compared.

METHOD

Between 2000 and 2007, 2511 stage II/III colorectal carcinoma patients received primary surgical resection at the Asan Medical Center (Seoul, Korea). All patients were staged using AJCC-6 and AJCC-7 TNM systems. Patients with synchronous or other cancers, those given preoperative chemotherapy or radiotherapy and those in whom fewer than 12 lymph nodes were resected, were excluded. Overall survival (OS) and disease-free survival (DFS) were compared.

RESULTS

Of 2511 patients, 255 (10.2%) had different stages in the AJCC-6 and AJCC-7. For the AJCC-7, the 5-year OS by stage was 94.2% for stage IIA, 88.8% for stage IIB, 83.5% for stage IIC, 91.8% for stage IIIA, 81.8% for stage IIIB and 72.0% for stage IIIC. The OS and the DFS were not significantly different for the new substages IIB (n = 57) and IIC (n = 34) (P = 0.34 and P = 0.87, respectively). For the 187 patients with stage T3N2a cancer, the OS and the DFS were significantly different from stage IIIB other than T3N2a (P = 0.008 and P = 0.01, respectively) and there were no statistically significant differences in OS between the T3N2a group and the IIIC group (P = 0.46).

CONCLUSION

The study indicates that AJCC-7 has better prognostic validity than AJCC-6 for staging of patients with stage II and stage III colorectal carcinoma.