Relationship between recurrence and age in the diffuse sclerosing variant of papillary thyroid carcinoma: clinical significance in pediatric patients.

Background: The diffuse sclerosing variant (DSV) is among the aggressive variants of papillary thyroid carcinoma (PTC) and is more prevalent in pediatric patients than in adult patients. Few studies have assessed its characteristics owing to its low incidence. We aimed to evaluate the relationship between recurrence and age in the DSV of PTC. Methods: We retrospectively reviewed patients diagnosed with the DSV or conventional PTC (cPTC) after surgery at a medical center between May 1988 and January 2019. We compared the clinico-pathological characteristics and surgical outcomes of the DSV and cPTC groups and between adult and pediatric patients with DSV. Results: Among the 24,626 patients, 202 had the DSV, and 24,424 were diagnosed with cPTC. The recurrence rate was significantly higher in the DSV group than in the cPTC group. In the DSV group, the recurrence rate was significantly higher in the pediatric patient group than in the adult patient group. Moreover, the association between recurrence and age group showed different patterns between the DSV and cPTC groups with restricted cubic splines (RCS). While both RCS curves showed a U-shaped distribution, the RCS curve tended to be located within the younger age group. Conclusions: This study demonstrated that pediatric patients with DSV are at a greater risk for recurrence compared with adult patients; moreover, the pattern of recurrence risk according to age is different from that of cPTC.

Innovative eco-friendly hydroxyethylcellulose matrix-based composite for enhanced gas separation: Insights from performance and structural characterization.

With increasing concern for the environment, the demand for carbon dioxide separation, a key contributor to global warming, has escalated. Therefore, this paper focuses on carbon dioxide separation by creating an hydroxyethyl cellulose (HEC)(C2H6O2)x*(C6H7O2(OH)3)n/silver tetra fluoroborate (AgBF4)/aluminum nitrate (Al(NO3)3) composite film, demonstrating excellent separation performance with a permeance of 1.0 GPU and a selectivity of 100. Silver ions enhance the solubility of carbon dioxide, aiding in its separation, and we determined the optimal aluminum composition to stabilize the silver ions. To analyze this, we examined the cross-sections using SEM, confirming a selective layer of 1.7 µm for carbon dioxide separation. Furthermore, TGA, FT-IR, and NMR analyses were conducted to investigate the interaction between the polymer and additives. This revealed that the increased polymer chain due to the interaction between Ag and HEC, along with stabilized Ag facilitated by the addition of Al, maximized the interaction with carbon dioxide via the empty s-orbital. Additionally, SEM-EDX, UV-vis, XRD, XPS analyses were employed to elucidate the movement of ions within the membrane. These results provide insights into the performance of membranes based on cellulose polymer and offer valuable insights for future applications in gas separation technologies.

Association between Consumption of Iodine-Rich Foods and Thyroid Cancer Prevalence: Findings from a Large Population-Based Study.

The influence of iodine-rich foods on thyroid cancer (TC) risk remains inadequately understood. Therefore, we aimed to comprehensively investigate the relationship between three iodine-rich food groups and TC prevalence using extensive data from a large Korean population. We assessed the dietary intake of 169,057 participants in the Korean Genome and Epidemiology Study (2004-2013) using a food frequency questionnaire. The top-three iodine-rich food groups (including egg, seaweed, and dairy) were selected based on Korean dietary reference intakes and categorized by weekly consumption frequency. We conducted multiple logistic regression models to examine the relationship between food consumption and TC prevalence. After adjusting for confounding factors, higher seaweed consumption (>5 times/week) was significantly associated with lower TC prevalence (odds ratio [OR], 95% confidence interval [CI] = 0.42, 0.32-0.56, p-value < 0.001). In contrast, compared with moderate dairy consumption (3-4 times/week), lower dairy product intake (<1 time/week) was associated with higher TC prevalence (OR, 95% CI = 1.32, 1.05-1.67, p-value = 0.017). Our findings suggest that sufficient seaweed consumption may offer protection against TC, and incorporating dairy products into the diet may lower TC incidence in the Korean population. The most significant limitations of our study are the absence of 24 h urine samples for iodine status assessment and the lack of clinical data on the diagnosis of thyroid cancer.

Protective Role of Rapamycin in Fibrotic Liver Ischemia/Reperfusion Injury (C57bl/6 Mouse).

BACKGROUND: Liver ischemia/reperfusion injury (IRI) is a well-documented phenomenon that occurs after liver resection and transplantation, posing a significant clinical challenge. We aim to contribute valuable insights into potential therapeutic interventions for fibrotic liver IRI, ultimately advancing our understanding of liver transplantation and resection outcomes. METHODS: Twenty-four mice were divided randomly into 4 equal groups: [1] the normal group, n = 6; [2] the liver fibrosis (LF) group, n = 6; [3] the LF and IR group, n = 6; and [4] the LF with treatment of rapamycin and IR group; n = 6. RESULTS: Key biomarkers assessing liver function, alanine aminotransferase and aspartate aminotransferase, significantly decreased with Rapamycin administration. There is a substantial decrease observed in inflammatory cytokines such as interleukin (IL) 6, IL-1B, tumor necrosis factor alpha, Transforming growth factor-beta (TGF-beta), and Inducible nitric oxide synthase (iNOS) with rapamycin treatment. Furthermore, NOX levels, caspase-3, and caspase-9 were reduced after rapamycin administration. CONCLUSION: The application of rapamycin demonstrates appropriate effects in anti-inflammation, antioxidation, and anti-apoptosis, indicating significant therapeutic potential for fibrotic liver IRI.

Expansion of thyroid surgical territory through 10,000 cases under the da Vinci robotic knife.

With the progress of robotic transaxillary thyroid surgery (RTTS), the indications for this procedure have gradually expanded. This study presents the insights gained from performing 10,000 RTTS cases at a single institution, along with the expansion of indications over time. RTTS was performed on 10,000 patients using the da Vinci robot system between October 2007 and April 2023 at the Yonsei University Health System, Seoul, Korea. Among 10,000 patients, 9461 (94.0%) were diagnosed with thyroid cancer, whereas 539 (5.4%) had either a benign thyroid nodule or Graves' disease. Surgical procedures were performed using four-arm-based robots (da Vinci S, Si, or Xi) for 8408 cases (84.1%), with the remaining 1592 cases (15.9%) being performed using the da Vinci SP surgical robotic system. Notably, for 53 patients with nodules ≥ 5 cm, which were not included in the eligibility criteria of the previous study, RTTS was performed safely without significant complications. The most common postoperative complication was transient hypoparathyroidism (37.91%), and recurrence occurred in 100 patients with thyroid cancer (1.1%). In conclusion, RTTS appears safe and feasible from both surgical and oncological perspectives, and the spectrum of indications suitable for RTTS surgery is progressively expanding.

Mass transport to generate the channels in cellulose polymers by vacuum-assisted process.

This study developed a pore-connected PP-CA membrane by coating cellulose acetate onto a polypropylene filter. A new method was proposed to attach a CA/glycerin coating layer to a porous PP support without a separate binder. The pores of CA and PP were interconnected using a vacuum filtration device. By adding glycerin to the CA chains, the membrane region became more flexible due to glycerin plasticization. Water passed through the membrane under pressure differences, resulting in the formation of interconnected pores between cellulose acetate and polypropylene. The pore size and quantity could be adjusted by varying the molar ratio of glycerin. Fourier transform infrared spectroscopy revealed the interaction between CA and glycerin, while thermogravimetric analysis showed that the membrane's thermal stability increased by approximately 20 °C after vacuum filtration. This simple and cost-effective manufacturing process holds potential for mass-producing separators in the lithium-ion battery industry.

Channels formation in cellulose materials by accelerated transport of gas molecules and glycerin.

In this study, a microporous separator was produced using cellulose acetate (CA), which demonstrates heightened thermal stability in comparison to existing materials like polypropylene (PP) or polyethylene (PE). Furthermore, a pliable component was integrated into the CA membrane using glycerin as the plasticizing agent. Subsequently, gas pressure was exerted onto these areas to induce the formation of nano-sized pores. Examination through Scanning Electron Microscopy (SEM) unveiled the presence of abundant pores in the glycerin-plasticized areas. This substantiates that the pores generated under gas pressure were not only more uniform but also smaller than those created under water pressure. The interaction between CA and glycerin was validated using Fourier-Transform Infrared Spectroscopy (FT-IR), offering confirmation that a portion of the glycerin was extracted following the application of gas pressure. Additionally, the application of Thermogravimetric Analysis (TGA) allowed for an assessment of the thermal stability of the CA membrane, along with a verification of glycerin's removal post gas pressure treatment. The findings indicated that the incorporation of glycerin diminished the thermal stability of the CA membrane due to the plasticization effect. Furthermore, it was observed that a minor quantity of glycerin still persisted after the gas pressure treatment. Following the analysis of gas permeation, the porosity of the CA membrane was quantified at 78.8 %, exhibiting an average pore size measuring 224 nm.

The effects of perioperative dexmedetomidine infusion on hemodynamic stability during laparoscopic adrenalectomy for pheochromocytoma: a randomized study.

Introduction: Pheochromocytoma is a rare catecholamine-producing neuroendocrine tumor originating from the adrenal medulla chromaffin cells. Hemodynamic instability can occur during the induction of anesthesia and surgical manipulation of the tumor. This study investigated the effects of intraoperative dexmedetomidine administration on hemodynamic stability in patients undergoing laparoscopic adrenalectomy for pheochromocytoma. Methods: Forty patients who underwent laparoscopic adrenalectomy for pheochromocytoma were randomly assigned to the dexmedetomidine (n = 20) or control (n = 20) group. The primary outcome of this study was intraoperative hemodynamic stability, and the secondary endpoint was the plasma catecholamine concentrations, specifically of epinephrine and norepinephrine. Results: The intraoperative maximum blood pressures were significantly lower in the dexmedetomidine group (control vs. dexmedetomidine group: 182 ± 31 vs. 161 ± 20, 102 ± 17 vs. 90 ± 10, and 128 ± 22 vs. 116 ± 12 [mean ± SD] mmHg and p = 0.020, 0.015, and 0.040 for systolic, diastolic, and mean blood pressure, respectively). The maximum heart rate during surgery was 108 ± 15 bpm in the control group and 95 ± 12 bpm in the dexmedetomidine group (p = 0.010). Other parameters of hemodynamic instability were comparable between both groups. Plasma catecholamine concentrations did not differ between the groups. Conclusion: Dexmedetomidine infusion following the induction of anesthesia at a rate of 0.5 µg/kg/h significantly attenuated the maximum intraoperative SBP, DBP, MBP, and HR, contributing to improved hemodynamic stability.

Do large thyroid nodules (≥4 cm) without suspicious cytology need surgery?

Background: Fine-needle aspiration biopsy (FNAB) is a good diagnostic tool for thyroid nodules; however, its high false-negative rate for giant nodules remains controversial. Many clinicians recommend surgical resection for nodules >4 cm owing to an increased risk of malignancy and an increased false-negative rate. This study aimed to examine the feasibility of this approach and investigate the incidence of malignancy in thyroid nodules >4 cm without suspicious cytology based on medical records in our center. Methods: This was a retrospective analysis of 453 patients that underwent preoperative FNAB for nodules measuring >4 cm between January 2017 and August 2022 at Severance Hospital, Seoul. Results: Among the 453 patients, 140 nodules were benign and 119 were indeterminate. Among 259 patients, the final pathology results were divided into benign (149) and cancerous (110) groups, and the prevalence of malignancy was 38.9% in the benign group and 55.5% in the indeterminate group. Among the malignancies, follicular carcinoma and follicular variants of papillary carcinoma were observed in 83% of the cytologically benign group and 62.8% of the indeterminate group. Conclusion: Preoperative FNAB had high false-negative rates and low diagnostic accuracy in patients with thyroid nodules >4 cm without suspicious cytologic features; therefore, diagnostic surgery may be considered a treatment option.

Gas transport into cellulose materials for highly porous structure.

To solve the low thermal stability of polyolefin membranes, our group developed porous polymers using cellulose acetate (CA) material. The formation of pores in CA involved creating plasticized regions within the CA membrane using additives. By applying gas pressure to these regions, a CA/glycolic acid membrane could be prepared with a small average pore size and high porosity. According to the porosimeter measurement, the average pore size of the membrane was 150 nm, and the porosity was 77%. SEM observations of the surface and cross-section of the CA/glycolic acid membrane confirmed the abundant distribution of fine pores. Furthermore, IR analysis revealed the removal of glycolic acid from the membrane after pore formation, indicating its interaction with CA during the process of gas permeation. Additionally, TGA analysis demonstrated a decrease in thermal stability due to the formation of numerous pores after gas permeation.

Remote-access thyroidectomy with the da Vinci SP system: feasibility in a cadaveric model.

Background: This study aims to study the feasibility of a remote-access thyroidectomy through presternal and submental approaches with the da Vinci SP system. Methods: Bilateral thyroidectomies were performed in five cadaveric models. A single incision in the presternal area was used in two cadavers, and a submental facelift incision approach was used in three cadavers. Results: Performing remote-access thyroidectomy was completed with a presternal approach in one cadaver and with the submental approach in three cadavers. The required skin flap development was minimal, and the docking time for the SP system was quick for all procedures. Time to full exposure of the thyroid gland after skin incision was less than 30 min for the presternal approach and less than 27 min for the submental procedure. Completing total thyroidectomies took 83 min in the presternal approach and between 67 and 127 min in the submental access. No additional ports were required to expose the gland and complete the bilateral resection. Conclusions: Total thyroidectomy was feasible with the da Vinci SP system in single incision presternal and submental approaches comparing promisingly with other currently applied robotic methods. Further studies will be required to assess whether a presternal or submental thyroidectomy with the da Vinci SP system provides clinical benefits in real patients.

Effects of Deep Neuromuscular Block during Robot-Assisted Transaxillary Thyroidectomy: A Randomized Controlled Trial.

The occurrence of significant pain and paresthesia after robot-assisted transaxillary thyroidectomy has been reported, and some patients experience chronic symptoms even three months after surgery. This study scrutinized the effects of deep neuromuscular block during robot-assisted transaxillary thyroidectomy on postoperative pain and sensory changes. In this single-blinded, prospective, randomized, controlled trial, 88 patients who underwent robot-assisted transaxillary thyroidectomy were enrolled and randomly allocated to either the moderate or deep neuromuscular block groups. Study endpoints included postoperative pain, paresthesia, and sensory change after surgery. The linear mixed models for numeric rating scale pain scores in the chest, neck, and axilla all showed significant intergroup differences over time (p = 0.003 in chest; p = 0.001 in neck; p = 0.002 in axilla). In the post hoc analysis with Bonferroni correction, the pain scores of the chest, neck, and axilla were significantly lower in the deep neuromuscular block group on postoperative day one compared to the moderate neuromuscular block group (adjusted p < 0.001 in chest, neck, and axilla). This study demonstrated that deep neuromuscular block could reduce postoperative pain after robot-assisted transaxillary thyroidectomy. However, it could not demonstrate that deep neuromuscular block reduces paresthesia or hypoesthesia after the surgery.

Preparation of Porous Hydroxyethyl Cellulose Materials to Utilize Lactic Acid with Vacuum-Assisted Process.

For the first time, we succeeded in manufacturing a 2-hydroxyethyl cellulose (HEC)-based composite membrane with improved thermal stability, for use as a battery separator, coating a HEC polymer solution to a polypropylene (PP) support and using a vacuum-assisted process. A HEC polymer solution was prepared by utilizing HEC and lactic acid (LA) as a plasticizer. A vacuum-assisted process was used to move ethanol, which a mobile phase to permeate a plasticized region in the HEC polymer side for pore formation. The pores formed with uniform nano sizes, and areas in which some large pores formed were observed. The thermal stability of the composites was measured using TGA. The thermal decomposition temperatures were measured at about 250 °C for the neat HEC, about 210 °C for the HEC/LA film, and about 335 °C for the HEC/LA/PP membrane before the process. After the vacuum-assisted process, the first and second thermal decomposition were observed at about 360 °C and 450 °C, respectively. The HEC/LA/PP membrane after the process showed greater thermal stability than before the process. This means that the adhesion between the HEC polymer and the PP support was created through the rearrangement of the HEC chain, as LA escaped after the process, and it was seen indirectly that the mechanical strength was enhanced. In particular, the surface of the membrane was observed by SEM to investigate whether the HEC penetrated into the PP to block its pores, and whether the HEC region collapsed. Furthermore, the interaction of the HEC chain with the additives and the rearrangement of the HEC was confirmed using FT-IR. As a result, we demonstrated that the mechanical strength and thermal stability of the manufactured HEC/LA/PP membrane were enhanced.

Evaluation of delphinidin as a storage medium for avulsed teeth.

BACKGROUND: Delphinidin (DP), an anthocyanidin found in blueberries, has antioxidant and anti-inflammatory effects. This study aimed to investigate the efficacy of DP as a storage medium for avulsed teeth. METHODS: Human periodontal ligament cells were cultured and exposed to DP solution (10, 50, and 100 µM), Dulbecco's modified Eagle's medium, Hank's balanced salt solution and tap water. Cell counting kit-8 assays were performed after 0.5, 1, 6, and 24 h to measure the cell viability. Nitric oxide assays and gelatin zymography were performed to evaluate the anti-inflammatory effects of DP. Reverse transcription-polymerase chain reaction was used to determine the expression levels of inflammatory cytokines. RESULTS: The viability of periodontal ligament cells was greatest at 100 µM DP. At 1 h, 100 µM DP decreased nitric oxide synthesis (p < .0167). Matrix metallopeptidase-9 activity was inhibited by DP in a dose-dependent manner (p < .0167). Moreover, treatment with 100 µM DP decreased the expression levels of tumor necrosis factor (TNF)-α, interleukin (IL)-6, and IL-8 in periodontal ligament cells (p < .0167). CONCLUSIONS: Within the limits of this study, DP preserved the viability and suppressed the inflammatory response of periodontal ligament cells. These findings suggest that DP could be promising for preservation of avulsed teeth.

Single-Port Transaxillary Robotic Modified Radical Neck Dissection (STAR-RND): Initial Experiences.

OBJECTIVES: This study aimed to demonstrate the usefulness of single-port transaxillary robotic modified radical neck dissection (STAR-RND) for metastatic thyroid cancer, and its potential to make small and invisible surgical wounds possible compared to open modified radical neck dissection. METHODS: Between January 2020 and July 2021, 30 thyroid cancer patients who underwent lateral neck dissection surgery with the da Vinci SP at Yonsei University Health System (Seoul, Korea) were studied. RESULTS: All 30 patients, diagnosed with papillary thyroid cancer were women. The average operating time was 293.80 ± 36.58 (min), and the average postoperative hospital stay was 4.77 ± 0.57 (days). All patients were discharged after the expected number of hospitalization days without major complications. CONCLUSION: STAR-RND is technically feasible and safe with a short length of the incision. To our knowledge, this is the first report on the use of a single-port robotic system for modified radical neck dissection. LEVEL OF EVIDENCE BY USING 2011 OCEBM: 4 Laryngoscope, 133:709-714, 2023.

TERT Promoter and BRAF V600E Mutations in Papillary Thyroid Cancer: A Single-Institution Experience in Korea.

Telomerase reverse transcriptase (TERT) promoter mutation has been investigated for its clinical and prognostic significance in aggressive papillary thyroid cancer (PTC). In this study, we aimed to assess the prevalence, clinicopathologic features, and treatment outcomes of TERT mutation-positive PTCs along with the common BRAF V600E mutation. We performed mutational analyses for BRAF and the TERT promoter in thyroid cancer patients who had undergone surgery at our institution since 2019. We reviewed and analyzed 7797 patients with PTC in this study. The prevalence of BRAF V600E and TERT promoter mutations was 84.0% and 1.1%, respectively. Multifocal gene mutations in bilateral PTCs were identified. TERT promoter mutations were associated with older age, larger tumor size, tumor multifocality, tumor variants, advanced stages, more adjuvant radioactive iodine treatment (RAI), higher stimulated serum thyroglobulin level before RAI, and more uptakes in the regions outside the surgical field on a post-RAI whole-body scan. The coexistence of BRAF V600E and TERT promoter mutations exacerbated all clinicopathologic characteristics. The frequency of TERT promoter mutations was the lowest in this study, compared to previous studies. TERT promoter mutations consistently correlated with aggressive PTCs, and the synergistic effect of both mutations was evident. Specific clinical settings in our institution and in Korea may have led to these distinctive results. Prospective multicenter studies with longer follow-up periods are required to establish valuable oncologic outcomes.

Thyroid lobectomy is sufficient for differentiated thyroid cancer with upgraded risk after surgery.

Background: It is difficult to reliably distinguish between American Thyroid Association (ATA) low-risk and intermediate-risk differentiated thyroid cancer (DTC) before surgery. Therefore, physicians are faced with a dilemma regarding the necessity and timing of completion total thyroidectomy (CT) after thyroid lobectomy (TL). We evaluated proper surgical methods by analyzing oncologic outcomes of TL in patients with DTC whose risk had been upgraded after surgery. Methods: We retrospectively reviewed the medical records of 1,702 patients with DTC who underwent TL and ipsilateral central lymph node (LN) dissection between January 2006 and December 2011. The patients were classified into Group A (n=1,159; low risk; ≤5 central LN metastases or the absence of pathologic microscopic capsular invasion) and Group B (n=543; upgraded intermediate risk after surgery; >5 central LN metastases or the presence of pathologic microscopic capsular invasion). We analyzed their clinicopathological characteristics and recurrence-free survival. Results: All 32 patients who experienced recurrence underwent CT. After the first operation, the duration until reoperation in Groups A and B were 8.00±2.74 (range, 3.42-12.17) and 5.10±3.09 (range, 1.25-11.67) years, respectively. There was no significant difference in recurrence rates, disease-related mortality rates, or 10-year recurrence-free survival rates between the two groups. The mean follow-up durations in Groups A and B were 10.22±1.58 and 10.13±1.47 years, respectively. Univariate analysis showed that sex, age, tumor size, multifocality, extrathyroidal extension (ETE), and number of central LN metastases were not associated with recurrence after TL, although the rate of central LN metastases was. Multivariate analysis showed that sex, age, tumor size, multifocality, ETE, central LN metastases, and the number of central LN metastases were not associated with recurrence after TL, although multifocality was. Conclusions: TL with prophylactic central compartment neck dissection (CCND) is sufficient for patients with DTC whose risk is upgraded after surgery because they have a good prognosis at long-term follow-up. Larger-scale randomized clinical trials are required to confirm our findings.

Efficacy and safety of temperature-sensitive acellular dermal matrix in prevention of postoperative adhesion after thyroidectomy: A randomized, multicenter, double-blind, non-inferiority study.

INTRODUCTION: MegaShield® is a newly developed temperature-sensitive anti-adhesive containing micronized acellular dermal matrix. The aim of this study was to investigate the efficacy and safety of MegaShield® compared with Guardix-SG® in the prevention of adhesions in patients undergoing bilateral total thyroidectomy. METHOD: We conducted a multicenter trial between October 2018 and March 2020 in patients undergoing total thyroidectomy. The patients were randomly assigned to either the MegaShield® group or the Guardix-SG® group. The primary outcome was the esophageal movement using marshmallow six weeks after the surgery and the secondary outcome was the assessed adhesion score. The safety assessment was also evaluated. RESULTS: The study included 70 patients each in the MegaShield® and control (Guardix-SG®) groups. Baseline clinical characteristics, the mean score of marshmallow esophagography, and the sum of adhesion scores were not statistically different between the two groups. Inferiority test demonstrated that the efficacy of MegaShield® is not inferior to that of Guardix-SG®. There were no device-related complications in both groups. CONCLUSION: The efficacy and safety of MegaShield® were not inferior than those of Guardix-SG®. MegaShield® demonstrated the potential of ADM as a potential future anti-adhesive agent. TRIAL REGISTRATION: The name of trial registry CRIS (Clinical Research Information Service) https://cris.nih.go.kr/cris/index.jsp. (The full trial protocol can be accessed) Registration number: KCT0003204.

Formation of Nanochannels Using Polypropylene and Acetylcellulose for Stable Separators.

In this study, a polymer separator with enhanced thermal stability is prepared to solve the problem of thermal durability of lithium-ion battery separators. This separator is manufactured by coating a solution of acetyl cellulose and glycerin on polypropylene. The added glycerin reacts with the acetyl cellulose chains, helping the chains become flexible, and promotes the formation of many pores in the acetyl cellulose. To improve the thermal stability of the separator, a mixed solution of acetyl cellulose and glycerin was coated twice on the PP membrane film. Water pressure is applied using a water treatment equipment to partially connect the pores of a small size in each layer and for the interaction between the PP and acetyl cellulose. SEM is used to observe the shape, size, and quantity of pores. TGA and FT-IR are used to observe the interactions. Average water flux data of the separators is 1.42 LMH and the decomposition temperature increases by about 60 °C compared to the neat acetyl cellulose. It is confirmed that there is an interaction with PP between the functional groups of acetyl cellulose.

Interactions of Ag Particles Stabilized by 7,7,8,8-Tetracyanoquinodimethane with Olefin Molecules in Poly(ether-block-amide).

In this study, to use a stabilized carrier, silver nanoparticles (AgNPs) were used as carriers and electron acceptors were added to activate the surface of AgNPs as olefin carriers. In addition, poly(ether-block-amide) (PEBAX), consisting of polyamide (hard segments) and polyether (soft segments), was investigated for the correlation of the between-segments ratio related to the stability of AgNPs and separation performance. As a result, contrary to the expectation that high permeance would be observed in PEBAX-1657/AgNPs/7,7,8,8-tetracyanoquinodimethane (TCNQ) membrane, which had a higher ratio of polyether soft segment, the PEBAX-5513/AgNPs/TCNQ membrane, which had a relatively high proportion of polyamide, showed a higher permeance without difference in selectivity. These unexpected data were attributable to the fact that the relatively abundant amount of PA groups in PEBAX-5513 was able to stabilize and positively polarize the surface of AgNPs, resulting in the stabilized and high performance of olefin separation.