Phase-dependent Friction on Exfoliated Transition Metal Dichalcogenides Atomic Layers.

The fundamental aspects of energy dissipation on 2-dimensional (2D) atomic layers are extensively studied. Among various atomic layers, transition metal dichalcogenides (TMDs) exists in several phases based on their lattice structure, which give rise to the different phononic and electronic contributions in energy dissipation. 2H and 1T' (distorted 1T) phase MoS2 and MoTe2 atomic layers exfoliated on mica substrate are obtained and investigated their nanotribological properties with atomic force microscopy (AFM)/ friction force microscopy (FFM). Surprisingly, 1T' phase of both MoS2 and MoTe2 exhibits ≈10 times higher friction compared to 2H phase. With density functional theory analyses, the friction increase is attributed to enhanced electronic excitation, efficient phonon dissipation, and increased potential energy surface barrier at the tip-sample interface. This study suggests the intriguing possibility of tuning the friction of TMDs through phase transition, which can lead to potential application in tunable tribological devices.

Laparoscopic cholecystectomy in patients with previous upper midline abdominal surgery: comparison of laparoscopic cholecystectomy after gastric surgery and non-gastric surgery using propensity score matching.

BACKGROUND: Previous upper midline abdominal surgery is a reported relative contraindication to laparoscopic cholecystectomy. We aimed to investigate the effects of previous upper abdominal surgery on the feasibility and safety of laparoscopic cholecystectomy; we evaluated the effects of the previous upper abdominal surgery type on laparoscopic cholecystectomy with respect to complications and conversion to open surgery. METHODS: We prospectively evaluated 1,258 patients who underwent laparoscopic cholecystectomy, including those who underwent upper midline abdominal surgery previously, at a single tertiary referral center. The perioperative and postoperative outcomes-open conversion rate, operation time, intraoperative and postoperative complications, and length of hospital stay-were evaluated. Patients were grouped according to the previous surgical method into the gastric (n = 77), non-gastric (n = 40), and control (n = 1141) groups. Patients in the gastric + non-gastric groups (n = 117) were 1:1 matched with those in the control group (n = 117) using propensity score matching (PSM). RESULTS: Before PSM, age, sex, open conversion rate, gallbladder status, port number, overall morbidity, and postoperative hospital stay duration did not significantly differ between the gastric and non-gastric groups; the body mass index (22.3 ± 3.4 versus 24.1 ± 3.8 kg/m2, p = 0.009) and operation time (129.9 ± 63.6 versus 97.9 ± 51.1 min, p = 0.004) significantly differed. After PSM, age, sex, body mass index, and American Society of Anesthesiology score did not significantly differ between gastric + non-gastric (n = 117) and conventional groups (n = 117; the operation time (118.9 ± 61.3 versus 75.8 ± 37.1 min, p < 0.001), open conversion rate (n = 6, 5.1% versus n = 0, 0.0%, p = 0.013), port number, overall morbidities (n = 26, 22.2% versus n = 10, 8.5%, p = 0.004), and postoperative hospital stay duration (6.7 ± 4.3 versus 5.5 ± 3.2 days, p = 0.031) significantly differed. CONCLUSION: Previous upper midline abdominal surgery was not contraindicative to safe laparoscopic cholecystectomy. Patients with previous upper midline abdominal surgery undergoing laparoscopic cholecystectomy should be informed preoperatively of the probability of conversion to open surgery, lengthened duration, and associated morbidities.

Analysis of single nucleotide polymorphisms related to heifer fertility in Hanwoo (Korean cattle).

Genome-wide association studies (GWAS) have accelerated the identification of functional trait loci in cattle and identified single nucleotide polymorphisms (SNPs) in candidate genes associated with fertility and production traits in high milk yield dairy cattle. The fertility of Hanwoo (Korean native beef cattle) has declined after the adaptation of a selection program for high quantity and quality meat. However, there are few GWAS studies of fertility in beef cattle. We performed a genome-wide association study of 40 Korean native beef cattle heifers with imputed 770 K genotype and identified 12 significant SNPs within seven regions on three chromosomes (BTA 8, BTA 16 and BTA 24) associated with services per conception (SPC). Five SNPs were located in the ABCA1, BRINP3 and ESRRG genes, which are involved in early embryo development. In addition, 27 proximal genes were identified within 1 Mb of the candidate SNPs, which are involved in muscle cell differentiation and muscle structure development. However, we did not find any previously reported SNPs related to fertility in Holstein cows. Taken together, we identified SNPs associated with SPC and their proximal genes using gene-based analysis and the candidates were different from SNPs associated with subfertility of dairy cattle.

Estimation of breeding value and accuracy using pedigree and genotype of Hanwoo cows (Korean cattle).

The genetic improvement of Hanwoo is dependent on the estimated breeding value (EBV) of pedigree-based Korean proven bull's number, and the genetic evaluation for cows is difficult due to insufficient pedigree and test records. Genomic selection involves utilizing the individual's genotype to estimate the breeding value (BV) and is determined to be an appropriate evaluation method for cows who lack test information. This study used pedigree and genotype to estimate and analyse BV and accuracy of Hanwoo cows in the Gyeongnam area using pedigree best linear unbiased prediction (PBLUP) and genomic best linear unbiased prediction (GBLUP). The test group acquired pedigree and genotype of 919 Hanwoo cows in the Gyeongnam area. The traits used for analysis were carcass weight (CWT), eye muscle areas (EMA), backfat thickness (BFT) and marbling score (MS). PBLUP used Reference group 1 containing the pedigree and phenotype of 919 Hanwoo cows and 545,483 heads to construct the numeric relationship matrix and estimated the EBV and accuracy. GBLUP used Reference group 2 containing the genotype and phenotype of 919 Hanwoo cows and 17,226 heads to construct the genomic relationship matrix and estimated the genomic EBV (GEBV) and accuracy. In the order of CWT, EMA, BFT and MS, the accuracy of PBLUP was 0.488, 0.480, 0.482 and 0.486 while the accuracy of GBLUP was higher with 0.779, 0.758, 0.766 and 0.791. And for 104 cows without relationship coefficient on pedigree to the reference group, the accuracy as PBLUP was estimated to be 0, but for GBLUP, it was possible to estimate the accuracy for all individuals. If GBLUP is applied to cows raised in general farms, the genetic evaluation can be performed even on animals without pedigree and high-accuracy estimation, enabling selection of excellent cows. Accordingly, by securing the genetic diversity of cows, it is expected to increase the profitability of farms by decreasing the inbreeding rate and increasing efficiency of elite calf production.

Central Pancreatectomy Versus Distal Pancreatectomy and Pancreaticoduodenectomy for Benign and Low-Grade Malignant Neoplasms: A Retrospective and Propensity Score-Matched Study with Long-Term Functional Outcomes and Pancreas Volumetry.

BACKGROUND: It remains controversial whether central pancreatectomy (CP) can preserve the exocrine and endocrine function of the pancreas or not. This study aimed to evaluate the safety and efficacy of CP compared with distal pancreatectomy (DP) and pancreaticoduodenectomy (PD) for benign and low-grade malignant neoplasms. METHODS: This retrospective study enrolled 219 patients who underwent elective CP (n = 55), DP (n = 70), or PD (n = 94) for benign and low-malignant neoplasms in a single university hospital between January 2000 and December 2015. Patients who underwent CP were propensity score matched to patients who underwent DP or PD at a 1:1 ratio, respectively. Peri- and postoperative outcomes, long-term endocrine/exocrine function, and pancreatic volume change 12 months postoperatively were prospectively evaluated. RESULTS: Of the 165 patients, 55 were included in each of the CP, DP, and PD groups. Significant differences between the CP and DP groups were observed in overall morbidity (CP: n = 18, 33% vs DP: n = 8, 14%; P = 0.041), clinically relevant postoperative pancreatic fistula (CP: n = 13, 24% vs DP: n = 4, 7%; P = 0.022), stool elastase level 12 months after surgery (CP: 151 µg/g vs DP: 245 µg/g; P = 0.003), and percentage change in the remnant pancreatic volume 12 months after surgery (CP: - 9.4% vs DP: + 7.5%; P < 0.001). CONCLUSIONS: The indications for CP to treat benign and low-grade malignant pancreatic neoplasms should be limited to cases in which the distal pancreatic volume can be considerably saved and PD can be prevented because CP has a higher postoperative morbidity without a marked functional superiority over DP.

Effects of electrical stimulation combined with dysphagia therapy in elderly individual with oropharyngeal dysphagia: a case study.

[Purpose] The purpose of the present study was to investigate the effects of dysphagia therapy in an old man with difficulty swallowing in the oral and pharyngeal phases. [Subjects and Methods] The subject was a 72-year-old man with no history of neurological disorders. He was admitted to local hospital because of the complaint of swallowing difficulty. The interventions performed were electrical stimulation and conventional dysphagia therapy. We assessed the tongue and lip muscle strengths. Swallowing function was evaluated by using the videofluoroscopic dysphagia and penetration-aspiration scales. [Results] After the intervention, the tongue and lip muscle strengths increased from 35 to 39 kPa and from 18 to 23 kPa, respectively. Moreover, the oral and pharyngeal phases of the videofluoroscopic dysphagia scale were improved. Furthermore, aspiration decreased from 4 to 2 points in the penetration-aspiration scale. [Conclusion] Our results suggest that electrical stimulation and conventional dysphagia therapy were effective in improving the swallowing function in an elderly individual with dysphagia.

Effect of mirror therapy and electrical stimulation on upper extremity function in stroke with hemiplegic patient: a pilot study.

[Purpose] This study investigated the effects of mirror therapy and neuromuscular electrical stimulation on upper extremity function in stroke patients. [Subjects and Methods] This study recruited 8 stroke patients. All patients were treated with mirror therapy and neuromuscular electrical stimulation five times per week for 4 weeks. Upper limb function evaluation was performed using upper extremity part of fugl meyer assessment. [Results] Before and after intervention, fugl meyer assessment showed significant improvement. [Conclusion] In this study, mirror therapy and neuromuscular electrical stimulation are effective methods for upper extremity function recovery in stroke patients.

Actual Long-Term Survival Outcome of 403 Consecutive Patients with Hilar Cholangiocarcinoma.

BACKGROUND: Despite aggressive surgical resection, prognosis of patients with hilar cholangiocarcinoma is still unsatisfactory. There were limited data about actual long-term survival outcome. This study was designed to explore actual long-term survival outcome of hilar cholangiocarcinoma after surgical treatment, and to investigate the characteristics of patients with actual long-term survival. METHODS: The study cohort consisted of 403 consecutive patients with at least 5-year follow-up after surgical treatment for hilar cholangiocarcinoma at Seoul National University Hospital between 1991 and 2010. Prognostic factors were analyzed with Cox proportional hazard models, and the effect of adjuvant treatment was evaluated by propensity score analysis. RESULTS: Of all patients, R0 resection rate was 41.2 and 63.8 % among intended curative resection. Adjuvant therapy was performed in 48.8 % after curative surgery. Actual 5-year overall survival (OS) rate was 18.9, and 30.1 % after R0 resection. Actual 5-year disease-free survival rate was 25.8 % after resection. Adjuvant treatment improved prognosis in patients with positive metastatic lymph nodes (median OS 21.9 vs. 11.5 months, p = 0.003). Overall recurrence rate was 55.0 %, and distant metastasis (39.7 %) was more frequent than loco-regional recurrence (20.8 %). Lymph node metastasis (p = 0.021) and poor histologic grade (p < 0.001) were independent prognostic factors after curative resection. Patients who survived more than 5 years had less lymph node metastasis (p = 0.025), poor histologic differentiation (p = 0.010), R2 resection (p = 0.040), and recurrence (p < 0.001). CONCLUSION: Actual 5-year OS rate after R0 resection of hilar cholangiocarcinoma is 30.1 %. Adjuvant treatment could be beneficial in patients with lymph node metastasis.

Pancreatic volume and endocrine function changes following pancreaticoduodenectomy for peri-ampullary neoplasms: A retrospective single-center study utilizing pancreas volumetry.

Backgrounds/Aims: We evaluated long-term pancreatic functional outcomes, including pancreatic volumetry after pancreaticoduodenectomy (PD) for peri-ampullary neoplasm. Methods: We retrospectively reviewed 353 patients with a 12-month follow-up who underwent elective pancreaticoduodenectomies for peri-ampullary neoplasms at a single university hospital between January 2011 and December 2020. Perioperative and postoperative outcomes, long-term pancreatic endocrine functions, and pancreatic volume changes 12 month postoperatively were evaluated. Results: The mean age was 65.4 years, and the sex ratio was 1.38. The patients with prediagnosed diabetes mellitus (DM) comprised 31.4%. The peri-ampullary neoplasm origins were: the pancreas (49.0%), common bile duct (27.2%), ampulla of Vater (18.4%), and duodenum (5.4%). The 1-week, and 3-, 6-, and 12-month postoperative proportions of patients with DM diagnosed before surgery combined with new-onset postoperative DM were 39.7%, 42.8%, 43.9%, and 49.6%, respectively. The preoperative and postoperative 1-week, and 3-, 6-, and 12-month mean pancreatic volumes were 82.3, 38.7, 28.1, 24.9, and 25.5 mL, respectively. Univariate risk factor analyses for new-onset DM after PD observed no significant difference between the 'No DM after PD' and 'New-onset DM after PD' groups. Conclusions: Following PD for peri-ampullary neoplasms, pancreatic endocrine functions and volumes continued to decrease for a minimum of 12 months. The current study did not identify any causal relationship between pancreatic endocrine dysfunction and pancreatic atrophy following PD.

The Impact of the Multiple Bile Ducts on Postoperative Biliary Complications In Patients Undergoing Living Donor Liver Transplantation.

BACKGROUND: We aimed to investigate the correlation between bile duct number and biliary complications in patients who underwent donor liver transplantation (LDLT). METHODS: We reviewed all patients who underwent LDLT in our hospital between July 2008 and December 2020. The patients were divided into 2 groups according to the number of bile ducts in the living donor graft (single duct [SD] or multiple ducts [MD]). Collected data included donor and recipient demographics, surgical data including bile duct reconstruction, and perioperative and postoperative outcomes. No prisoners were used in this study, and participants were neither coerced nor paid. The current study complies with the Helsinki Congress and the Declaration of Istanbul. RESULTS: All 70 patients were classified as SD (n = 48) and MD (n = 22). Complications related to the bile duct occurred in 27 (38.6%) patients and were more common in the MD group (54.5% vs 31.3%; odds ratio, 2.4). The MD patients had a longer operation time (1052 ± 251 vs 910 ± 215 minutes, P = .019) and a higher percentage of hepaticojejunostomy (31.8% vs 8.3%, P = .012). Donor age, graft-recipient weight ratio, cold ischemic time, and transfusion volume did not differ between groups. Twenty-one patients (77.7%) fully recovered from complications related to the bile duct, but 3 patients (4.3%) had liver graft failure. CONCLUSION: Bile duct-related complications were common in LDLT patients, despite overall good results. Multiple bile ducts may be a potent risk factor for postoperative biliary complications.

Identification of Missense Variants Affecting Carcass Traits for Hanwoo Precision Breeding.

This study aimed to identify causal variants associated with important carcass traits such as weight and meat quality in Hanwoo cattle. We analyzed missense mutations extracted from imputed sequence data (ARS-UCD1.2) and performed an exon-specific association test on the carcass traits of 16,970 commercial Hanwoo. We found 33, 2, 1, and 3 significant SNPs associated with carcass weight (CW), backfat thickness (BFT), eye muscle area (EMA), and marbling score (MS), respectively. In CW and EMA, the most significant missense SNP was identified at 19,524,263 on BTA14 and involved the PRKDC. A missense SNP in the ZFAND2B, located at 107,160,304 on BTA2 was identified as being involved in BFT. For MS, missense SNP in the ACVR2B gene, located at 11,849,704 in BTA22 was identified as the most significant marker. The contribution of the most significant missense SNPs to genetic variance was confirmed to be 8.47%, 2.08%, 1.73%, and 1.19% in CW, BFT, EMA, and MS, respectively. We generated favorable and unfavorable haplotype combinations based on the significant SNPs for CW. Significant differences in GEBV (Genomic Estimated Breeding Values) were observed between groups with each favorable and unfavorable haplotype combination. In particular, the missense SNPs in PRKDC, MRPL9, and ANKFN1 appear to significantly affect the protein's function and structure, making them strong candidates as causal mutations. These missense SNPs have the potential to serve as valuable markers for improving carcass traits in Hanwoo commercial farms.

Comparison on genomic prediction using pedigree BLUP and single step GBLUP through the Hanwoo full-sib family.

OBJECTIVE: When evaluating individuals with the same parent and no phenotype by pedigree best linear unbiased prediction (BLUP), it is difficult to explain carcass grade difference and select individuals because they have the same value in pedigree BLUP (PBLUP). However, single step GBLUP (ssGBLUP), which can estimate the breeding value suitable for the individual by adding genotype, is more accurate than the existing method. METHODS: The breeding value and accuracy were estimated with pedigree BLUP and ssGBLUP using pedigree and genotype of 408 Hanwoo cattle from 16 families with the same parent among siblings produced by fertilized egg transplantation. A total of 14,225 Hanwoo cattle with pedigree, genotype and phenotype were used as the reference population. PBLUP obtained estimated breeding value (EBV) using the pedigree of the test and reference populations, and ssGBLUP obtained genomic EBV (GEBV) after constructing and H-matrix by integrating the pedigree and genotype of the test and reference populations. RESULTS: For all traits, the accuracy of GEBV using ssGBLUP is 0.18 to 0.20 higher than the accuracy of EBV obtained with PBLUP. Comparison of EBV and GEBV of individuals without phenotype, since the value of EBV is estimated based on expected values of alleles passed down from common ancestors. It does not take Mendelian sampling into consideration, so the EBV of all individuals within the same family is estimated to be the same value. However, GEBV makes estimating true kinship coefficient based on different genotypes of individuals possible, so GEBV that corresponds to each individual is estimated rather than a uniform GEBV for each individual. CONCLUSION: Since Hanwoo cows bred through embryo transfer have a high possibility of having the same parent, if ssGBLUP after adding genotype is used, estimating true kinship coefficient corresponding to each individual becomes possible, allowing for more accurate estimation of breeding value.

Multi-biomarker panel prediction model for diagnosis of pancreatic cancer.

BACKGROUND/PURPOSE: The current study aimed to develop a prediction model using a multi-marker panel as a diagnostic screening tool for pancreatic ductal adenocarcinoma. METHODS: Multi-center cohort of 1991 blood samples were collected from January 2011 to September 2019, of which 609 were normal, 145 were other cancer (colorectal, thyroid, and breast cancer), 314 were pancreatic benign disease, and 923 were pancreatic ductal adenocarcinoma. The automated multi-biomarker Enzyme-Linked Immunosorbent Assay kit was developed using three potential biomarkers: LRG1, TTR, and CA 19-9. Using a logistic regression model on a training data set, the predicted values for pancreatic ductal adenocarcinoma were obtained, and the result was classification into one of the three risk groups: low, intermediate, and high. The five covariates used to create the model were sex, age, and three biomarkers. RESULTS: Participants were categorized into four groups as normal (n = 609), other cancer (n = 145), pancreatic benign disease (n = 314), and pancreatic ductal adenocarcinoma (n = 923). The normal, other cancer, and pancreatic benign disease groups were clubbed into the non-pancreatic ductal adenocarcinoma group (n = 1068). The positive and negative predictive value, sensitivity, and specificity were 94.12, 90.40, 93.81, and 90.86, respectively. CONCLUSIONS: This study demonstrates a significant diagnostic performance of the multi-marker panel in distinguishing pancreatic ductal adenocarcinoma from normal and benign pancreatic disease states, as well as patients with other cancers.

Automated pancreas segmentation and volumetry using deep neural network on computed tomography.

Pancreas segmentation is necessary for observing lesions, analyzing anatomical structures, and predicting patient prognosis. Therefore, various studies have designed segmentation models based on convolutional neural networks for pancreas segmentation. However, the deep learning approach is limited by a lack of data, and studies conducted on a large computed tomography dataset are scarce. Therefore, this study aims to perform deep-learning-based semantic segmentation on 1006 participants and evaluate the automatic segmentation performance of the pancreas via four individual three-dimensional segmentation networks. In this study, we performed internal validation with 1,006 patients and external validation using the cancer imaging archive pancreas dataset. We obtained mean precision, recall, and dice similarity coefficients of 0.869, 0.842, and 0.842, respectively, for internal validation via a relevant approach among the four deep learning networks. Using the external dataset, the deep learning network achieved mean precision, recall, and dice similarity coefficients of 0.779, 0.749, and 0.735, respectively. We expect that generalized deep-learning-based systems can assist clinical decisions by providing accurate pancreatic segmentation and quantitative information of the pancreas for abdominal computed tomography.

Long-term surgical outcomes in patients with hepatocellular carcinoma undergoing laparoscopic vs. open liver resection: A retrospective and propensity score-matched study.

BACKGROUND/OBJECTIVES: There is limited availability of well-designed comparative studies using propensity score matching with a sufficient sample size to compare laparoscopic liver resection (LLR) vs. open liver resection (OLR) for hepatocellular carcinoma (HCC). We aimed to compare the feasibility and safety of LLR and OLR in patients with HCC. METHODS: We enrolled 168 patients who underwent elective LLR (n = 58) or OLR (n = 110) for HCC in two tertiary medical centers between November 2009 and December 2018. Patients who underwent LLR were propensity score-matched to patients who underwent OLR in a 1:1 ratio. Perioperative and postoperative outcomes and disease-free and overall survival rates were prospectively evaluated. RESULTS: Among the 116 patients analyzed, 58 each belonged to the LLR and OLR groups. We performed 85 segmentectomies or sectionectomies, 19 left-lateral-sectionectomies, 9 left-hemihepatectomies, and 3 right-hemihepatectomies. There was no significant difference in age, sex, Child-Pugh class, original liver disease, preoperative alpha-fetoprotein, tumor size, tumor location, overall morbidity, and operative time. There was a significant difference in the length of postoperative hospital stay between the two groups (LLR vs OLR; 8 vs 10 days, p = 0.003). The 1-, 3-, and 5-year overall survival rates in the LLR and OLR groups were 96.6%, 92.8%, and 73.3% and 93.1%, 88.8%, and 76.1%, respectively (p = 0.642). The 1-, 3-, and 5-year disease-free survival rates in the LLR and OLR groups were 84.4%, 64.0%, and 60.2% and 93.1%, 67.4%, and 63.9%, respectively (p = 0.391). CONCLUSION: LLR for HCC can be performed safely with acceptable short-term and long-term outcomes compared with OLR.

Comparison of Selection Signatures between Korean Native and Commercial Chickens Using 600K SNP Array Data.

Korean native chickens (KNCs) comprise an indigenous chicken breed of South Korea that was restored through a government project in the 1990s. The KNC population has not been developed well and has mostly been used to maintain purebred populations in the government research institution. We investigated the genetic features of the KNC population in a selection signal study for the efficient improvement of this breed. We used 600K single nucleotide polymorphism data sampled from 191 KNCs (NG, 38; NL, 29; NR, 52; NW, 39; and NY, 33) and 54 commercial chickens (Hy-line Brown, 10; Lohmann Brown, 10; Arbor Acres, 10; Cobb, 12; and Ross, 12). Haplotype phasing was performed using EAGLE software as the initial step for the primary data analysis. Pre-processed data were analyzed to detect selection signals using the 'rehh' package in R software. A few common signatures of selection were identified in KNCs. Most quantitative trait locus regions identified as candidate regions were associated with traits related to reproductive organs, eggshell characteristics, immunity, and organ development. Block patterns with high linkage disequilibrium values were observed for LPP, IGF11, LMNB2, ERBB4, GABRB2, NTM, APOO, PLOA1, CNTN1, NTSR1, DEF3, CELF1, and MEF2D genes, among regions with confirmed selection signals. NL and NW lines contained a considerable number of selective sweep regions related to broilers and layers, respectively. We recommend focusing on improving the egg and meat traits of KNC NL and NW lines, respectively, while improving multiple traits for the other lines.

The impact of Model for End-Stage Liver Disease score on deceased donor liver transplant outcomes in low volume liver transplantation center: a retrospective and single-center study.

PURPOSE: In June 2016, the Model for End-Stage Liver Disease (MELD) score was employed in South Korea instead of the Child-Turcotte-Pugh (CTP) score. This study compared the outcomes of deceased donor liver transplantation (DDLT) before and after the MELD system application. METHODS: This retrospective study reviewed 48 patients who underwent DDLT for end-stage liver disease at a single tertiary referral center between January 2014 and December 2018. The patients were categorized into the pre-MELD (22 patients) and post-MELD (26 patients) groups. The demographics, postoperative outcomes, and overall survival time were evaluated between the 2 groups. RESULTS: The 2 groups had no differences in age, sex, ABO type, etiology for liver transplantation, CTP-score, operation time, cold ischemic time, and amount of red blood cell transfusion, although their MELD score differed significantly (post-MELD group, 36.2 ± 4.9; pre-MELD group, 27.7 ± 11.8; P < 0.001). The post-MELD group has longer intensive care unit stay (11.2 ± 9.5 days vs. 5.7 ± 4.5 days, P = 0.018) and hospital stay than the pre-MELD group (36.8 ± 26 days vs. 22.8 ± 9.3 days, P = 0.016). The 1-year survival rate was lower in the post-MELD group (61.5% vs. 86.4%, P = 0.029). CONCLUSION: After MELD allocation, patients with high MELD scores had increased DDLT and consequently required a longer recovery time, which could negatively affect survival. According to the experience of a small-volume center, these problems were related to both severe organ shortages in South Korea and MELD allocation.

Accuracy of genotype imputation based on reference population size and marker density in Hanwoo cattle.

Recently, the cattle genome sequence has been completed, followed by developing a commercial single nucleotide polymorphism (SNP) chip panel in the animal genome industry. In order to increase statistical power for detecting quantitative trait locus (QTL), a number of animals should be genotyped. However, a high-density chip for many animals would be increasing the genotyping cost. Therefore, statistical inference of genotype imputation (low-density chip to high-density) will be useful in the animal industry. The purpose of this study is to investigate the effect of the reference population size and marker density on the imputation accuracy and to suggest the appropriate number of reference population sets for the imputation in Hanwoo cattle. A total of 3,821 Hanwoo cattle were divided into reference and validation populations. The reference sets consisted of 50k (38,916) marker data and different population sizes (500, 1,000, 1,500, 2,000, and 3,600). The validation sets consisted of four validation sets (Total 889) and the different marker density (5k [5,000], 10k [10,000], and 15k [15,000]). The accuracy of imputation was calculated by direct comparison of the true genotype and the imputed genotype. In conclusion, when the lowest marker density (5k) was used in the validation set, according to the reference population size, the imputation accuracy was 0.793 to 0.929. On the other hand, when the highest marker density (15k), according to the reference population size, the imputation accuracy was 0.904 to 0.967. Moreover, the reference population size should be more than 1,000 to obtain at least 88% imputation accuracy in Hanwoo cattle.

Who Drives Green Innovation? A Game Theoretical Analysis of a Closed-Loop Supply Chain under Different Power Structures.

As awareness of environmental protection increases worldwide, enterprises have been building their supply chains in ways that conserve natural resources and minimize the creation of pollutants. One of the practical ways to make supply chains more sustainable is for enterprises to utilize green innovation strategies and to increase resource reuse. In this work, we focus on a closed-loop supply chain (CLSC) consisting of a manufacturer, a retailer, and a collector. In the investigated CLSC, the manufacturer and the retailer drive the green innovation strategy either individually or simultaneously to boost market demand. In the reverse flow of the CLSC, the collector is responsible for collecting consumers' used products and transferring them to the manufacturer for remanufacturing. By combining two types of the market leadership and three types of green innovation strategies, we establish six different Stackelberg game models and solve them analytically. Through an extensive comparative analysis, we show who should have market leadership and who should drive the green innovation strategy in the CLSC. Various numerical examples are also given to support our major findings. One of our key findings suggests that the supply chain members must participate in green innovation activities at the same time to achieve a win-win scenario in the CLSC.