정책지원자금의 유형을 중심으로

학위논문(석사) -- 서울대학교대학원 : 행정대학원 행정학과(행정학전공), 2022.2. 이수영.In the new trends such as era of low growth, growth without employment, and the fourth industrial revolution, the economic and policy significance of SMEs, especially venture companies and start-ups are growing. Considering the proportion of SMEs that account for 99.9% of the total number of businesses and 89.8% of the number of workers in Korea, as specified in Article 123 (3) of the Constitution, the protection and fostering of SMEs is both a national duty and a basis for national economic policy. Despite active government policies such as diversification of support policies and expansion of support and beneficiaries, there are difficulties such as limited national resources and rapid environmental changes at home and abroad surrounding domestic SMEs. Therefore, it is necessary to enhance the effectiveness of existing support projects, to secure efficiency through performance evaluation and redesign of support policies, and to continuously seek policy implications and maximize policy effects. This study focuses on analyzing the effectiveness of various types of funding policies and seeks policy implications for effective resource allocation between types. This approach is based on the assumption that existing studies focus on the analysis of policy effectiveness for each type of support, but that the funding faced or felt by each individual SMEs will be complex rather than specific for each support policy. Through the analysis and comparison of effectiveness by policy type such as government contributions, credit guarantee support, and government loans, this study intends to suggest implications and development directions for resource allocation between policy types. This study verified the impact of financial performance, non-financial performance, and long-term growth expectations for each policy type through multiple regression analysis using ‘Servey of Korea Venture Firms’. According to the analysis results, even when classifying the types of policy funding, it was difficult to confirm a significant positive relationship between performance and government support like some previous studies. According to the actual analysis results, contrary to the general notion and expectations that government policy funding will have a positive effect on corporate performance, The relationship between government policy funding and performance shows similar results to previous studies that do not have statistical significance or further confirm negative relationship. According to this study, the necessity of developing and researching non-financial performance evaluation indicators that are insufficient compared to financial performance indicators may be confirmed. In addition, implications for future policy tasks that require improvement of systems and evaluation tools for long-term performance measurement beyond the short-term performance of venture companies may be also confirmed.저성장시대, 고용 없는 성장, 4차 산업혁명과 같은 새로운 흐름 속에서 중소기업, 그중에서도 벤처기업, 스타트업이 갖는 경제적, 정책적 의미가 커져가고 있다. 전체 사업체수의 99.9%, 종사자 수의 89.8%를 차지하고 있는 중소기업의 비중을 생각할 때 헌법 제123조 제3항에서 명시하듯 중소기업의 보호 및 육성은 국가적 의무인 동시에, 국가 경제정책의 근간으로 평가되어야 한다. 이를 위한 지원정책의 다양화, 지원 규모 및 수혜기업의 확대와 같은 적극적인 정부정책에도 불구하고, 한정된 국가재원 및 국내 중소기업을 둘러싼 국내외의 급격한 환경변화 등을 고려하면, 기존 지원사업의 효과성을 제고하고, 지원정책의 성과평가 및 재설계를 통한 효율성 확보를 위하여 지속적으로 정책적 시사점 모색하고, 정책효과 극대화를 위한 노력을 이어나갈 필요성이 제기된다. 본 연구는 그 중에서도 다양한 자금지원정책의 유형별 효과성 분석에 초점을 두고, 유형간 효과적인 자원배분을 위한 정책적 시사점을 모색해 보고자 한다. 이는 기존의 연구들이 특정 지원유형 별 정책효과성의 분석에 집중하고 있으나, 각 개별 중소기업이 직면하거나, 체감하는 자금지원은 각 지원정책에 대하여 개별적이기 보다는 복합적일 것이라는 가정 아래에서 출발한다. 이를 통하여 정부출연금, 신용보증지원, 정부융자와 같은 정책유형별 효과성의 분석 및 비교를 통해 정책 유형간 자원배분에 대한 시사점과 발전방향을 제언해보고자 한다. 이를 위하여 본 연구는 중소벤처기업부, (사)벤처기업협회에서 매년 진행하고 있는 벤처기업실태조사를 활용하여 각 정책유형별 재무적 성과, 비재무적 성과, 장기성장 기대전망에 대한 효과에 미치는 영향을 다중회귀분석을 통하여 검증하였다. 분석을 통하여 설정한 모형의 통계적 유의미성을 확인하였을 때, 일부 재무적 성과, 그리고 비재무적 성과(신규채용 예정인력 규모)에 관한 모형만이 유의미성을 확인할 수 있었다. 다른 모형(재무적 성과 중 순이익율 모형, 장기 성장전망기대 모형)의 경우, 일부 회귀계수가 통계적인 유의성을 나타내었지만, 모형 자체가 통계적 유의성을 갖지는 못하는 것으로 나타났다. 이는 정부의 정책적인 자금지원이 기업성과에 긍정적인 영향을 미칠 것이라는 일반적인 관념과 기대와 달리 실제 분석결과에 따를 때, 통계적 유의성을 갖지 못하거나 나아가 부정적인 영향력을 확인하는 기존 선행연구들과 유사한 결과를 보여준다. 또한, 본 연구과정 전반을 통하여 재무성과를 측정하는 다양한 평가지표에 비하여 비재무적 성과를 평가하기 위한 평가지표의 부족함을 확인할 수 있었고, 이를 개선하기 위한 후행 연구 및 개발의 필요성을 확인하였다. 또한, 벤처기업의 단기적 성과를 넘어 장기적인 성과측정을 위한 제도 및 평가도구의 개선이 필요하다는 향후 정책적 과제에 대한 시사점도 확인 가능하였다.제 1 장 서론 1 제 1 절 연구의 목적 및 필요성 1 제 2 절 연구의 범위 및 구성 4 제 2 장 벤처 지원정책 관련 현황 및 선행연구 5 제 1 절 정책자금지원 관련 개념 및 현황 5 1. 중소기업 개념과 현황 5 2. 벤처기업의 개념과 현황 6 3. 스타트업의 개념 8 제 2 절 정책자금지원 관련 이론 및 선행연구 9 1. 정책수단 주요 이론 9 2. 유인적 정책수단 14 3. 벤처기업 정책자금지원 유형 16 4. 정책수단 관련 선행연구 21 5. 벤처기업 성과측정 관련 선행연구 25 제 3 장 연구문제 및 연구방법 27 제 1 절 연구문제와 연구모형 27 제 2 절 변수의 설정 31 제 3 절 가설의 설정 35 제 4 장 연구분석 및 결과 37 제 1 절 분석대상 및 표본 구성 37 제 2 절 기술통계 분석 40 1. 종속변수 40 2. 독립변수 41 3. 통제변수 41 제 3 절 상관분석 43 제 4 절 회귀분석 45 1. 분석결과 47 2. 결과의 해석 48 제 5 장 결 론 50 제 1 절 연구의 요약 50 제 2 절 연구의 시사점 51 제 3 절 연구의 한계 및 향후 과제 54 참고문헌 57 Abstract 60석

Three-Dimensional Printed Mesh-Cage Replacement for a Metastatic Spinal Tumor and a Vertebral Compression Fracture: A Report of Two Cases

Harms mesh cages are commonly used in the treatment of metastatic spinal tumors by spondylectomy with cage insertion and posterior screw fixation. These cages are even useful for the surgical reconstruction of spinal deformities with mesh-cage replacement after vertebral column resection (VCR). Mesh cages can be customized by 3-dimensional (3D) printing based on the angle between the endplates for the requisite weight-bearing capacity and fit. This study reports two cases wherein a 75-year-old man and a 63-year-old woman were treated with reconstructive spondylectomy and mesh-cage replacement, followed by posterior screw fixation. The 75-year-old man was initially diagnosed with an L4 metastatic non-small cell lung carcinoma accompanied by a pathologic fracture and severe paralysis. The 63-year-old woman had slipped 13 years before and sustained a T11-L1 compression fracture that was aggravated 6 months before this admission, with back pain and numbness in both soles. Herein, we describe the treatment approach with instrumentation using a customized 3D-printed mesh cage after total spondylectomy for the metastatic spinal tumor and after VCR for deformity repair surgery in the respective cases. Our application of a 3D-printed mesh cage in surgery for a metastatic tumor is the first report of such treatment in Korea. Although the use of customized 3D-printed cages for a metastatic spinal tumor and a severe compression fracture was effective, challenges remain regarding fitting, manufacturing time, and costs.ope

Studies on Antimicrobial Peptides and Epigenetic Factors in Transgenic Birds

학위논문 (박사)-- 서울대학교 대학원 : 농생명공학부, 2013. 8. 한재용.In this study, we investigated the relative expression of the Rous sarcoma virus (RSV) promoter-driven expression of enhanced green fluorescent protein (EGFP) in fibroblasts of transgenic quails. We analyzed the direct influence of CpG methylation of the RSV promoter on the transcriptional activity of delivered transgenes. Embryonic fibroblasts collected from homozygous trans-genic quail (TQ2) were treated with 50 μM of DNA methyltransferase inhibitor followed by 5-aza-2´-deoxy-cytidine (5-azadC) for 48 h, and changes in expression were then analyzed by flow cytometry. The results show a significant increase of EGFP expression in TQ2 embryonic fibroblasts (QEFs) (2.64% to 79.84%). Subsequent methylation-specific amplification revealed that 5-azadC significantly reduced the CpG methylation status in the RSV promoters of the QEFs (86.42 to 48.41%)even after 5-azadC was withdrawn, CpG methylation remained decreased in expanded culture (16.28%). Further analysis showed that potential transcription factor binding sites existed in the CpG methylation site of the RSV promoter. These results may provide the basis for understanding the epigenetic mechanism responsible for transgenic animal production and genetic preservation. DNA methylation reprograming of primordial germ cells (PGCs) in mammals establishes monoallelic expression of imprinting genes, maintains retrotransposons in an inactive state, inactivates one of the two X chromosomes, and suppresses gene expression. However, the roles of DNA methylation in chickens PGCs are unknown. In this study, we found a 1.5-fold or greater difference in the expression of 261 transcripts when comparing PGCs and chicken embryonic fibroblasts (CEFs) using an Affymetrix GeneChip Chicken Genome Array. In addition, we analyzed the methylation patterns of the regions ~5-kb upstream of 261 sorted genes, 51 of which were imprinting homologous loci and 49 of which were X-linked homologous loci in chicken using the MeDIP Array by Roche NimbleGen. Seven hypomethylated and five hypermethylated regions within the 5-kb upstream regions of 261 genes were found in PGCs when compared with CEFs. These differentially methylated regions were restrictively matched to differentially expressed genes in PGCs. We also detected 203 differentially methylated regions within imprinting and X-linked homologous regions between male PGCs and female PGCs. These differentially methylated regions may be directly or indirectly associated with gene expression during early embryonic development, and the epigenetic difference could be evolutionally conserved between mammals and birds. The basic functions of DNA methylation include in gene silencing by methylation of specific gene promoters, defense of the host genome from retrovirus, and transcriptional suppression of transgenes. In addition, genomic imprinting, by which certain genes are expressed in a parent-of-origin-specific manner, has been observed in a wide range of plants and animals and has been associated with differential methylation. However, imprinting phenomena of DNA methylation effects have not been revealed in chickens. To analyze whether genomic imprinting occurs in chickens, methyl DNA immunoprecipitation array analysis was applied across the entire genome of germ cells in early chick embryos. A differentially methylated region (DMR) was detected in the eighth intron of the L-arginine:glycine amidinotransferase (GATM) gene. When the DMR in GATM was analyzed by bisulfite sequencing, the methylation in male primordial germ cells (PGC) of 6-d-old embryos was higher than that in female PGC (57.5 vs. 35.0%). At 8 d, the DMR methylation of GATM in male PGC was 3.7-fold higher than that in female PGC (65.0 vs. 17.5%). Subsequently, to investigate mono- or biallelic expression of the GATM gene during embryo development, we found 2 indel sequences (GTTTAATGC and CAAAAA) within the GATM 3′-untranslated region in Korean Oge (KO) and White Leghorn (WL) chickens. When individual WL and KO chickens were genotyped for indel sequences, 3 allele combinations (homozygous insertion, homozygous deletion, and heterozygotes) were detected in both breeds using a gel shift assay and high resolution melt assay. The deletion allele was predominant in KO, whereas the insertion allele was predominant in WL. Heterozygous animals were evenly distributed in both breeds (P < 0.01). Despite the different methylation status between male and female PGC, the GATM gene conclusively displayed biallelic expression in PGC as well as somatic embryonic, extraembryonic, and adult chicken tissues. Cathelicidins are antimicrobial peptide components of the innate immune system. Four cathelicidins have been identified in the chicken: cathelicidin1 (CATH1), cathelicidin2 (CATH2), cathelicidin3 (CATH3), and cathelicidinB1 (CATHB1). The aim of this study was to characterize the antibacterial activities, structural conservation and expression patterns of these antimicrobial peptides. All had a highly conserved functional domain. The expression of CATH1, CATH2, and CATH3 mRNA was high in the bone marrow of adult female chickens. By contrast, CATHB1 mRNA was highly expressed in the thymus. The active domains of all four chicken cathelicidins were synthesized, and their antibacterial activities on cell viability, membrane damage, and colony formation of Escherichia coli were examined. After treatment of E. coli with 0.5–10 μM of each cathelicidin, CATH1, CATH2, and CATH3 reduced cell viability at all concentrations. When E. coli were treated with 5 μM of each cathelicidin, CATH2 and CATH3 demonstrated maximum damage to the cell membrane. To examine the effect on colony formation, an ampicillin-resistant E. coli strain was established and treated with 5 μM of each cathelicidin. CATH1, CATH2, and CATH3 markedly arrested colony formation, whereas CATHB1 had no effect. The present results demonstrate dose-dependent antimicrobial effects of chicken cathelicidins that were mediated by membrane damage and had a mechanism independent of that of common antibiotics. Our data suggest a novel approach for controlling drug-resistant bacteria and for producing disease-resistant animals in the livestock industry.ABSTARACT……………………………………………………i CONTENTS…………………………………………… vi LIST OF FIGURES……………………………………………………. x LIST OF TABLES……………………………………………………... xii LIST OF ABBREVIATION……………………………………………. xiii CHAPTER 1. GENERAL INTRODUCTION………………………… 1 CHAPTER 2. LITERATURE REVIEW…………………..………….. 5 1. Transgenic animals.….……………………………..………... 6 1.1. Generation of transgenic animals….. …………..…………… 6 1.2. Transgenic Aves………………………………………………. 9 1.3. Transgene silencing …………….……………………………. 10 2. DNA methylation……………………………………………... 12 2.1. General function of DNA methylation .…...…………………. 12 2.1.1. Control of gene expression ………………………...………… 13 2.1.2. Embryonic development ………………………….………….. 14 vii 2.1.3. Genomic imprinting ………………………………………….. 15 2.2. DNA methyltransferase………………………………………. 17 2.3. DNA methylation in birds…………………………………….. 17 3. Antimicrobial peptides……………………………………….. 19 3.1. General introduction of antimicrobial peptides………………. 19 3.2. Structures of antimicrobial peptides………………………….. 20 3.3. Activities of antimicrobial peptides…………………………... 21 3.4. Immnomodulation of antimicrobial peptides………………… 22 3.5. Antimicrobial peptide in birds………………………………... 25 3.5.1. Defensin………………………………………………………. 25 3.5.2. LEAP-2……………………………………………………….. 28 3.5.3. Cathelicidins…………………………………………………... 29 CHAPTER 3. Reactivation of Transgene Expression by Alleviation of CpG Methylation in Rous sarcoma virus Promoter in Transgenic Quail Cells……………………………………………………………………. 35 1. Introduction………………………………………………….. 36 2. Materials and methods……………………………………….. 37 3. Results………………………………………………………... 37 4. Discussion……………………………………………………. 50 CHAPTER 4. Gene Expression and DNA Methylation Status of Chicken Primordial Germ Cells………………………………………... 53 1. Introduction………………………………………………….. 54 2. Materials and methods……………………………………….. 57 3. Results and discussion.............................................................. 63 CHAPTER 5. Biallelic Expression of the L-Arginine:Glycine Amidinotransferase Gene with Different Methylation Status between Male and Female Primordial Germ Cells in Chickens………………… 78 1. Introduction………………………………………………….. 79 2. Materials and methods……………………………………….. 81 3. Results………………………………………………………... 87 4. Discussion……………………………………………………. 100 CHAPTER 6. Structure, expression and antibacterial analysis of chicken cathelicidin……………………………………………………. 103 1. Introduction………………………………………………….. 104 2. Materials and methods……………………………………….. 106 3. Results………………………………………………………... 112 4. Discussion……………………………………………………. 126 CHAPTER 7. GENERAL DISCUSSION……………………………... 131 SUMMARY IN KOREAN…………………………………………….. 136 REFERENCE..…………………………………………………………. 141 ACKNOWELDGEMENTS……………………………………………171Docto

Does Graft Position Affect Subsidence After Anterior Cervical Discectomy and Fusion?

Study design: Retrospective cohort study. Objective: Implant subsidence is an important prognostic factor after anterior cervical discectomy and fusion (ACDF). Our purpose in this study was to investigate whether graft position affects subsidence after ACDF and to determine if there is a difference in clinical results based on allograft subsidence and position. Methods: We reviewed 92 patients who underwent single-level ACDF with allograft and plate between January 2012 and October 2018. Treatment levels were divided based on allograft position within 2 mm of the posterior margin of the augmented plate (Anterior group) or at greater than 2 mm (Center group). Subsidence was defined as segmental vertebral body height decrease of 2 mm or more at 1 year compared to 1 week after surgery. Results: Overall subsidence prevalence was 15 (16%) cases. Subsidence was 11% in the Anterior group (8/73) and 39% in the Center group (7/19; P = .012). The subsidence group showed smaller graft footprint size (graft/endplate ratio) compared with the nonsubsidence group, and pseudarthrosis occurred frequently in the subsidence. There was no significant difference in clinical results according to graft position. These findings indicate that anterior graft position reduces risk of subsidence (95% confidence interval = 0.085-0.949). Conclusion: To minimize risk of subsidence, the graft should be positioned on the anterior position of the surgical-level endplate. In addition, using a graft appropriate for endplate size will further reduce subsidence.ope

Influence of Frailty on Life Expectancy in Octogenarians After Lumbar Spine Surgery

Objective: Many studies have reported positive surgical outcomes and decreased mortality after spine surgery in the elderly population, including patients between 85 and 90 years of age. Here, in addition to patient age, we investigated the influence of frailty on short and long-term mortality in octogenarians after lumbar surgery. Methods: We performed a retrospective analysis of 162 patients over 80 years of age who underwent posterior lumbar fusion or decompressive laminectomy between January 2011 and September 2016. We examined patient survival and modified frailty index (mFI) from medical records. Results: By October 2019, 29 of 162 patients had expired (follow-up period: 1-105 months). Three-month mortality was 1.9%, and 1-year mortality was 4.9%. Frailty did not affect long-term survival at 1 year but was associated with 3-month mortality (p = 0.024). Conclusion: There was no relationship in long-term survival according to frailty in patients 80 years of age or older, but a difference was identified in short-term mortality. When making a surgical decision for lumbar spine surgery in frail patients over 80 years of age, surgeons should pay attention to the short-term prognosis.ope

Comparison of Whole Spine Sagittal Alignment in Patients with Spinal Disease between EOS Imaging System versus Conventional Whole Spine X-ray

Purpose: The biplanar whole body imaging system (EOS) is a new tool for measuring the whole body sagittal alignment in a limited space. This tool may affect the sagittal balance of patients compared to conventional whole spine X-ray (WSX). This study aimed to investigate the difference in sagittal alignment between WSX and EOS. Materials and methods: We compared the spinal and pelvic sagittal parameters in 80 patients who underwent EOS and WSX within one month between July 2018 and September 2019. The patients were divided based on sagittally balanced and imbalanced groups according to pelvic tilt (PT) >20°, pelvic incidence-lumbar lordosis >10°, C7-sagittal vertical axis (SVA) >50 mm in WSX. Results: In the sagittally imbalanced group, compared to WSX, the pelvic parameters demonstrated compensation in EOS with smaller PT (27.4±11.6° vs. 24.9±10.9°, p=0.003) and greater sacral slope (SS), and the patients tended to stand more upright with smaller C7-SVA (58.4±17.0 mm vs. 48.9±57.3 mm, p=0.018), T1-pelvic angle (TPA), T5-T12, and T2-T12. However, in the sagittally balanced group, these differences were less pronounced only with smaller PT (10.8±6.9° vs. 9.4±4.7°, p=0.040), TPA and T2-T12 angle, but with similar SS and C7-SVA (p>0.05). Conclusion: EOS showed a negative SVA shift and lesser PT compared to WSX, especially in patients with sagittal imbalance. When preparing a surgical plan, surgeons should consider these differences between EOS and WSX.ope

Clinical Effect of Transverse Process Hook with K-Means Clustering-Based Stratification of Computed Tomography Hounsfield Unit at Upper Instrumented Vertebra Level in Adult Spinal Deformity Patients

Objective: This study aimed to investigate the efficacy of transverse process (TP) hook system at the upper instrumented vertebra (UIV) for preventing screw pullout in adult spinal deformity surgery using the pedicle Hounsfield unit (HU) stratification based on K-means clustering. Methods: We retrospectively reviewed 74 patients who underwent deformity correction surgery between 2011 and 2020 and were followed up for >12 months. Pre- and post-operative data were used to determine the incidence of screw pullout, UIV TP hook implementation, vertebral body HU, pedicle HU, and patient outcomes. Data was then statistically analyzed for assessment of efficacy and risk prediction using stratified HU at UIV level alongside the effect of the TP hook system. Results: The screw pullout rate was 36.4% (27/74). Perioperative radiographic parameters were not significantly different between the pullout and non-pullout groups. The vertebral body HU and pedicle HU were significantly lower in the pullout group. K-means clustering stratified the vertebral body HU ≥205.3, <137.2, and pedicle HU ≥243.43, <156.03. The pullout rate significantly decreases in patients receiving the hook system when the pedicle HU was from ≥156.03 to < 243.43 (p<0.05), but the difference was not statistically significant in the vertebra HU stratified groups and when pedicle HU was ≥243.43 or <156.03. The postoperative clinical outcomes improved significantly with the implementation of the hook system. Conclusion: The UIV hook provides better clinical outcomes and can be considered a preventative strategy for screw-pullout in the certain pedicle HU range.ope

The Fate of Proximal Junctional Vertebral Fractures after Long-Segment Spinal Fixation : Are There Predictable Radiologic Characteristics for Revision surgery?

Objective: To investigate the radiographic characteristics of the uppermost instrumented vertebrae (UIV) and UIV+1 compression fractures that are predictive of revision surgery following long-segment spinal fixation. Methods: A total 27 patients who presented newly developed compression fracture at UIV, UIV+1 after long segment spinal fixation (minimum 5 vertebral bodies, lowest instrumented vertebra of L5 or distal) were reviewed retrospectively. Patients were divided into two groups according to following management : revisional surgery (group A, n=13) and conservative care (group B, n=14). Pre- and postoperative images, and images taken shortly before and after the occurrence of fracture were evaluated for radiologic characteristics. Results: Despite similar degrees of surgical correction of deformity, the fate of the two groups with proximal junctional compression fractures differed. Immediately after the fracture, the decrement of adjacent disc height in group A (32.3±7.6 mm to 23.7±8.4 mm, Δ=8.5±6.9 mm) was greater than group B (31.0±13.9 mm to 30.1±15.5 mm, Δ=0.9±2.9 mm, p=0.003). Pre-operative magnetic resonance imaging indicated that group A patients have a higher grade of disc degeneration adjacent to fractured vertebrae compared to group B (modified Pfirrmann grade, group A : 6.10±0.99, group B : 4.08±0.90, p=0.004). Binary logistic regression analysis indicated that decrement of disc height was the only associated risk factor for future revision surgery (odds ratio, 1.891; 95% confidence interval, 1.121-3.190; p=0.017). Conclusion: Proximal junctional vertebral compression fractures with greater early-stage decrement of adjacent disc height were associated with increased risk of future neurological deterioration and necessity of revision. The condition of adjacent disc degeneration should be considered regarding severity and revision rate of proximal junctional kyphosis/proximal junction failures.ope