Discovery and Validation of Survival-Specific Genes in Papillary Renal Cell Carcinoma Using a Customized Next-Generation Sequencing Gene Panel.

PURPOSE: Papillary renal cell carcinoma (PRCC), the second most common kidney cancer, is morphologically, genetically, and molecularly heterogeneous with diverse clinical manifestations. Genetic variations of PRCC and their association with survival are not yet well-understood. This study aimed to identify and validate survival-specific genes in PRCC and explore their clinical utility. MATERIALS AND METHODS: Using machine learning, 293 patients from the Cancer Genome Atlas-Kidney Renal Papillary Cell Carcinoma (TCGA-KIRP) database were analyzed to derive genes associated with survival. To validate these genes, DNAs were extracted from the tissues of 60 Korean PRCC patients. Next generation sequencing was conducted using a customized PRCC gene panel of 202 genes, including 171 survival-specific genes. Kaplan-Meier and Log-rank tests were used for survival analysis. Fisher's exact test was performed to assess the clinical utility of variant genes. RESULTS: A total of 40 survival-specific genes were identified in the TCGA-KIRP database through machine learning and statistical analysis. Of them, 10 (BAP1, BRAF, CFDP1, EGFR, ITM2B, JAK1, NODAL, PCSK2, SPATA13, and SYT5) were validated in the Korean-KIRP database. Among these survival gene signatures, three genes (BAP1, PCSK2, and SPATA13) showed survival specificity in both overall survival (OS) (p = 0.00004, p = 1.38 × 10-7, and p = 0.026, respectively) and disease-free survival (DFS) (p = 0.00002, p = 1.21 × 10-7, and p = 0.036, respectively). Notably, the PCSK2 mutation demonstrated survival specificity uniquely in both the TCGA-KIRP (OS: p = 0.010 and DFS: p = 0.301) and Korean-KIRP (OS: p = 1.38 × 10-7 and DFS: p = 1.21 × 10-7) databases. CONCLUSIONS: We discovered and verified genes specific for the survival of PRCC patients in the TCGA-KIRP and Korean-KIRP databases. The survival gene signature, including PCSK2 commonly obtained from the 40 gene signature of TCGA and the 10 gene signature of the Korean database, is expected to provide insight into predicting the survival of PRCC patients and developing new treatment.

The Da Vinci Single-Port (SP) Treatment of Nutcracker Syndrome: A Case Report of a Novel Approach.

Nutcracker syndrome (NCS) is a rare disease affecting the left kidney. Surgical management is the only choice of treatment. Minimal invasive surgeries can be effective and may prevent complications of the major surgery. We present the case of a 33-year-old woman suffering from chronic left flank pain, diagnosed with NCS and treated with extravascular stents. Robotic-assisted extravascular stent insertion was performed using the Da Vinci single-port (SP) (Intuitive Surgical, Inc., Sunnyvale, USA) system. This approach offers the advantages of minimal invasiveness, precise stent placement, and reduced operative time. To our knowledge, this is the first case of using Da Vinci SP for this indication. Further studies are needed to evaluate the long-term outcomes and safety.

Non-Invasive Radiofrequency Hyperthermia Attenuates HMGB1/TLR4/NF-κB Inflammatory Axis in a Chronic Prostatitis/Chronic Pelvic Pain Syndrome Rat Model.

PURPOSE: The primary goal of this study is to evaluate the effect of the non-invasive radiofrequency hyperthermia (RFHT) device on chronic prostatitis/chronic pelvic pain syndrome (CP/CPPS) rat model and investigate the underlying mechanism. MATERIALS AND METHODS: In this study, Sprague-Dawley rats were randomly distributed into three groups: (1) normal control group, (2) CP/CPPS group, and (3) RFHT group. CP/CPPS rat models were induced by 17ß-estradiol and dihydrotestosterone for 4 weeks and RFHT was administered for 5 weeks after model establishment. During RFHT administration, core body temperatures were continuously monitored with a rectal probe. After administering RFHT, we assessed pain index for all groups and collected prostate tissues for Western blot analysis, immunofluorescence, and immunohistochemistry. We also collected adjacent organs to the prostate including urinary bladder, testes, and rectum for safety assessment via H&E staining along with a terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick end labeling assay. RESULTS: After administering RFHT, pain in rats was significantly alleviated compared to the CP/CPPS group. RFHT reduced high-mobility group box 1 (HMGB1) expression and improved inflammation by downregulating subsequent proinflammatory cytokines through inhibition of the toll-like receptor 4 (TLR4)-nuclear factor kappa B (NF-κB) pathway. In prostate-adjacent organs, no significant histological alteration or inflammatory infiltration was detected. The area of cell death also did not increase significantly after RFHT. CONCLUSIONS: In conclusion, RFHT demonstrated anti-inflammatory effects by inhibiting the HMGB1-TLR4-NF-κB pathway in CP/CPPS rat models. This suggests that RFHT could serve as a safe and promising therapeutic strategy for CP/CPPS.

Survival pattern of metastatic renal cell carcinoma patients according to WHO/ISUP grade: a long-term multi-institutional study.

The World Health Organization/International Society of Urological Pathology (WHO/ISUP) grading of renal cell carcinoma (RCC) is classified from grade 1-4, regardless of subtype. The National Comprehensive Cancer Network (NCCN) guidelines (2022) state that if there is an adverse pathological feature, such as grade 3 or higher RCC in stage 1 patients, more rigorous follow-up imaging is recommended. However, the RCC guidelines do not provide specific treatment or follow-up policies by tumor grade. Therefore, this study attempted to find out whether tumor grade affects survival rates in patients with metastatic RCC. The Korean Renal Cancer Study Group (KRoCS) database includes 3108 patients diagnosed with metastatic RCC between September 1992 and February 2017, with treatment methods, progression, and survival data collected from 11 tertiary hospitals. To obtain information on survival rates or causes of death, we utilized the Korea National Statistical Office database and institutional medical records. Data were accessed for research purpose on June, 2023. We then reviewed these sources to gather comprehensive and reliable data on the outcomes of our study cohort. This database was retrospectively analyzed, and out of 3108 metastatic RCC patients, 911 had been identified as WHO/ISUP grade. Grades were classified into either a low-grade (WHO/ISUP grade 1-2) or a high-grade group (WHO/ISUP grade 3-4). The patients were then analyzed related to progression and overall survival (OS). In metastatic clear cell RCC patients, the 1-year OS rate was 69.4% and the median OS was 17.0 months (15.5-18.5) followed up to 203.6 months. When comparing the patient groups, 119 low-grade and 873 high-grade cases were identified. No baseline difference was observed between the two groups, except that the high-grade group had a higher ECOG 1 ratio of 50.4% compared with 34.5% for the low-grade group (p = 0.009). There was a significant difference in OS between high-grade and low-grade groups. OS was 16.0 months (14.6-17.4) in the high-grade group and 28.0 months (21.1-34.9) in the low-grade group (p < 0.001). However, there was no difference in progression-free survival (PFS) rates with 9.0 months (8.0-10.0) for the high-grade group and 10.0 months (6.8-13.2) for the low-grade group (p = 0.377) in first-line treatment. In multivariable analysis, WHO/ISUP grade was a risk factor (HR = 1.511[1.135-2.013], p = 0.005) that influenced the OS. In conclusion, WHO/ISUP grade is a major data source that can be used as a ubiquitous marker of metastatic RCC in pre-IO era. Depending on whether the RCC is high or low grade, the follow-up schedule will need to be tailored according to grade, with higher-grade patients needing more active treatment as it can not only affect the OS in the previously known localized/locoregional recurrence but also the metastatic RCC patient.

Safety and Efficacy Assessment of Red Ginseng Oil (RXGIN) in Men with Lower Urinary Tract Symptoms in a Randomized, Double-Blind, Placebo-Controlled Trial.

PURPOSE: The purpose of this study was to evaluate the efficacy and safety of red ginseng oil (RXGIN) in men with lower urinary tract symptoms. MATERIALS AND METHODS: Men aged between 40 and 75 years with a total International Prostate Symptom Score (IPSS) of 8 to 19 points were recruited from April 2020 to December 2020. Subjects were randomly assigned to either the RXGIN group or the control group in a 1:1 ratio and received either RXGIN or placebo daily for 12 weeks. For the primary outcome, changes in IPSS scores at 6 and 12 weeks from baseline were analyzed. The secondary outcomes were changes in International Index of Erectile Function (IIEF), maximum urinary flow rate, and post-void residual volume at weeks 6 and 12 compared to baseline. Urine analysis and blood tests were additionally performed for safety assessment. RESULTS: A total of 88 subjects (RXGIN group, 46; control group, 42) completed the study. The total IPSS and IPSS subscores (residual urine sensation, frequency, intermittency, urgency, weak stream, straining, nocturia, and quality of life) were significantly improved in the RXGIN group compared to the control group at weeks 6 and 12. Total IIEF and sexual desire were significantly improved in the RXGIN group at week 6 and week 12, respectively, but there were no significant changes in the level of serum testosterone or dihydrotestosterone. The serum prostate-specific antigen showed significant decrease at weeks 12. No serious adverse events leading to discontinuation of the study drug were observed in the RXGIN group. CONCLUSIONS: Red ginseng oil (RXGIN) appears to be safe and effective in improving lower urinary tract symptoms in men and may also improve some aspects of sexual function.

Recurrence after postoperative intravesical instillation therapy in Hunner type interstitial cystitis.

We performed a prospective, single-arm study comparing outcomes between transurethral ablation plus postoperative instillation of hyaluronic acid and chondroitin sulfate (HACS group) and transurethral ablation only in patients with Hunner type interstitial cystitis (historical control group). A total of 78 patients were enrolled, and 51 were included in the per-protocol analysis set. The 2-year recurrence rate was 47.1% (95% CI, 32.9-61.5) in the HACS group, which was significantly lower than that in the control group (86.2%; 95% CI, 74.6-93.9, P < 0.001). After instillation therapy, the hazard ratio for recurrence was 0.38 (95% CI, 0.23-0.65, P < 0.001). The HACS group had an increased recurrence-free survival with the median interval not being reached, while it was 11.4 months in the control group (95% CI, 8.8-13.8, P < 0.001). Regardless of the instillation treatment, there were significant improvements in all symptom questionnaire scores and pain compared to the baseline. However, in the instillation group, improvement was stable even after 12 months. In patients with Hunner type interstitial cystitis, intravesical instillation of hyaluronic acid and chondroitin sulfate after transurethral ablation significantly reduced the recurrence rate and maintained symptom improvement for more than 1 year.

Retroperitoneal Single-Port Robot-Assisted Nephroureterectomy with Bladder Cuff Excision: Initial Experience and Description of the Technique.

BACKGROUND: With the introduction of the single-port (SP) robot, surgery that was difficult to attempt is becoming possible. Nephroureterectomy (NUx) for upper tract urothelial carcinoma also seems to be able to attempt a retroperitoneal (RP) approach. PURPOSE: to investigate the feasibility of SP robotic RP NUx with bladder cuff excision. DESIGN, SETTING, AND PARTICIPANTS: we sequentially analyzed 20 patients who underwent SP robot NUx from January 2021 to December 2022. SURGICAL PROCEDURE: all patients were diagnosed with upper tract urothelial carcinoma (UTUC) and were operated upon by a single expert using the da Vinci SP platform (Intuitive Surgical, Sunnyvale, CA, USA) with retroperitoneal approach. RESULTS AND LIMITATIONS: A total of 20 patients underwent SP robotic NUx with bladder cuff excision. The mean age of patients was 69.45 ± 8.68 years, and the mean body mass index (BMI) was 25.37 ± 3.00 kg/m2. The mean tumor size was 2.42 ± 1.03 cm on a CT scan, with right-sided tumors in eight patients (40%) and left-sided tumors in 12 patients (60%). The median console time was 106 min and 40 s, and the expected blood loss was 122.50 ± 75.18 mL. Final pathology showed that all of the patients were diagnosed as having urothelial carcinoma; one patient was classified as Ta (5.00%), three patients were classified as T1 (15.00%), seven patients were classified as T2 (35.00%), eight patients were classified as T3 (40.00%), and one patient was classified as T4 (5.00%). None of these 20 patients showed any complications based on the Clavien-Dindo scale. CONCLUSIONS: SP robotic NUx using a retroperitoneal approach provides feasible perioperative and postoperative outcomes for UTUC.

Comparing 12-core and 20-core biopsy for prostate cancer diagnosis with transperineal MR/US fusion biopsy: assessing the effective number of systemic cores using propensity score matching.

PURPOSE: For transperineal (TP) prostate biopsy, target biopsy for visible lesions on MRI is important, but there is no consensus of the number of systemic biopsy cores. Our study aimed to confirm the diagnostic efficiency of 20-core systemic biopsy by comparison with 12-core using propensity score matching (PSM). METHODS: The 494 patients conducted the naive TP biopsy were retrospectively analyzed. There were 293 patients with 12-core biopsy and 201 patients with 20-core biopsy. PSM was performed for minimizing confounding variables, and the established effects' value was analyzed for 'index-positive or negative' clinically significant prostate cancer (csPCa) (Index means PIRADS Score ≥ 3 on multiparametric prostate MRI). RESULTS: At 12-core biopsy, there were 126 cases of prostate cancer (43.0%), and 97 cases of csPCa (33.1%). At 20-core biopsy, there were 91 cases (45.3%) and 63 cases (31.3%). After propensity score matching, for index-negative csPCa, the estimated odds ratio was 4.03 (95% CI 1.35-12.09, p value 0.0128), and for index-positive csPCa, the estimated odds ratio was 0.98 (95% CI 0.63-1.52, p value 0.9308). CONCLUSIONS: The 20-core biopsy did not show a higher detection rate for csPCa in comparison with the 12-core biopsy. However, when MRI did not show a suspicious lesion, 20-core biopsy showed higher odd ratio in comparison with 12-core biopsy. Therefore, if there is a suspicious lesion in MRI, 20-core biopsy is excessive and 12-core biopsy is sufficient. Whereas if there is no suspicious lesion in MRI, it is better to proceed with 20-core biopsy.

Comparison of Transperitoneal and Retroperitoneal Partial Nephrectomy with Single-Port Robot.

Purpose: To investigate the efficacy and safety of single-port (SP) robotic transperitoneal (TP) and retroperitoneal (RP) partial nephrectomy. Materials and Methods: We sequentially analyzed 30 partial nephrectomy performed after the SP robot was introduced to the hospital in September 2021 to June 2022. All patients were found to have T1 renal cell carcinoma (RCCs) and were operated by a single expert in conventional robot with da Vinci SP platform. Results: Total of 30 patients underwent SP robotic partial nephrectomy with 16 (53.33%) by TP approach and 14 (47.67%) by RP. Body mass index was slightly higher in TP group (25.37 vs 23.53, p-value = 0.040). The other demographic information was not significantly different. There was no statistical difference in ischemic time (727.41 ± 561.18 seconds for TP and 698.56 ± 299.23 seconds for RP, p-value = 0.812), and console time (67.97 ± 24.06 minutes for TP and 69.71 ± 28.66 minutes for RP, p-value = 0.724). There was no statistical difference in perioperative and pathologic outcomes either. Postoperative renal function calculated from diethylenetriaminepentacetate was 103.33 mL/min/1.73 m2 for TP and 101.33 mL/min/1.73 m2 for RP (p-value = 0.214). And 90.36 mL/min/1.73 m2 for TP and 87.74 mL/min/1.73 m2 for RP at 90 days after surgery (p-value = 0.592). Conclusion: SP robot partial nephrectomy can be performed effectively and safely regardless of the approach. TP and RP approach offers similar perioperative and postoperative outcomes for T1 RCC. The Clinical Trial Registration number KC22WISI0431.

Collagen Type-I Agent Reduced Postoperative Bowel Adhesions Following Laparoscopic and Robot-Assisted Radical Prostatectomy: A Prospective, Single-Blind Randomized Clinical Trial.

This study aimed to compare the anti-adhesive effect of collagen type-I (COL) agent and hyaluronic acid-carboxymethylcellulose (HA/CMC) following laparoscopic and robotic radical prostatectomies. This study was a randomized, controlled, single-blind, multicenter study using COL and HA/CMC in patients who underwent laparoscopic and robotic radical prostatectomies. All patients were randomly assigned to either the COL (n = 66) or HA/CMC (n = 65) group. Viscera slide ultrasound sonography was recorded on the day of surgery (V2) and 12 weeks later (V4). The primary end point was the difference in the excursion distance in the viscera slide ultrasonography between V2 and V4. A total of 131 patients participated in this study. The viscera slide distance in the test and control groups was 1.89 ± 0.49 cm and 1.80 ± 0.45 cm, respectively, at V2 (p = 0.275). The average distance of the viscera slide in the test and control group was 1.59 ± 0.49 cm and 1.64 ± 0.45 cm, respectively at V4 (p = 0.614). None of the patients showed significant adverse effects. This randomized study showed that the efficacy and stability of the gel-type COL anti-adhesion agent are not inferior to those of HA/CMC, of which the properties are established.

A Prospective Observational Study of the Recurrence Characteristics of Hunner Lesion After Repeated Transurethral Ablation in Patients With Interstitial Cystitis/Bladder Pain Syndrome.

PURPOSE: The aim of this study was to investigate the rate and pattern of recurrence for patients with Hunner lesion (HL) type interstitial cystitis/bladder pain syndrome (IC/BPS) after transurethral ablation. METHODS: This prospective study included 210 patients with HL type IC/BPS. The primary outcomes were the recurrence rate according to 3 patterns of recurrence: pattern A (according to the relationship with the previous surgical site), pattern B (according to the bladder zone), and pattern C (according to the number of lesions). The secondary outcomes were recurrencefree time after treatment according to pattern A and pattern C. RESULTS: The pattern A recurrence rate was 50.8% in the same site (A1), 6.7% at a new site (A2), and 42.5% at mixed sites (A3). The pattern B recurrence rate was 10.5% for the anterior wall, 59.0% for the posterior wall, 69.5% for the lateral wall, and 69.0% for the dome area. Multiple lesions recurred as multiple lesions in 75.8% of cases. The pattern C recurrence rate was 10.8% for C1 (single → single), 6.7% for C2 (single → multiple), 6.7% for C3 (multiple → single), and 75.8% for C4 (multiple → multiple). The recurrence-free time in pattern A was 13 months for A1, 12.5 months for A2, and 8 months for A3, with a significant difference between A1 and A3 (P=0.008). There was no significant difference in recurrence-free time in pattern C, either with single or multiple HLs. CONCLUSION: The distinct recurrence characteristics of HLs was not predictable despite repeated ablations. Complete remission should not be expected because the whole bladder was to have the potential to develop the HLs even after repeated transurethral ablation.

Feasibility of a deep learning-based diagnostic platform to evaluate lower urinary tract disorders in men using simple uroflowmetry.

PURPOSE: To diagnose lower urinary tract symptoms (LUTS) in a noninvasive manner, we created a prediction model for bladder outlet obstruction (BOO) and detrusor underactivity (DUA) using simple uroflowmetry. In this study, we used deep learning to analyze simple uroflowmetry. MATERIALS AND METHODS: We performed a retrospective review of 4,835 male patients aged ≥40 years who underwent a urodynamic study at a single center. We excluded patients with a disease or a history of surgery that could affect LUTS. A total of 1,792 patients were included in the study. We extracted a simple uroflowmetry graph automatically using the ABBYY Flexicapture® image capture program (ABBYY, Moscow, Russia). We applied a convolutional neural network (CNN), a deep learning method to predict DUA and BOO. A 5-fold cross-validation average value of the area under the receiver operating characteristic (AUROC) curve was chosen as an evaluation metric. When it comes to binary classification, this metric provides a richer measure of classification performance. Additionally, we provided the corresponding average precision-recall (PR) curves. RESULTS: Among the 1,792 patients, 482 (26.90%) had BOO, and 893 (49.83%) had DUA. The average AUROC scores of DUA and BOO, which were measured using 5-fold cross-validation, were 73.30% (mean average precision [mAP]=0.70) and 72.23% (mAP=0.45), respectively. CONCLUSIONS: Our study suggests that it is possible to differentiate DUA from non-DUA and BOO from non-BOO using a simple uroflowmetry graph with a fine-tuned VGG16, which is a well-known CNN model.

Usefulness of MRI targeted prostate biopsy for detecting clinically significant prostate cancer in men with low prostate-specific antigen levels.

We aimed to evaluate the detection rates of prostate cancer (PCa) and clinically significant PCa (csPCa) using magnetic resonance imaging-targeted biopsy (MRI-TBx) in men with low prostate-specific antigen (PSA) levels (2.5-4.0 ng/mL). Clinicopathologic data of 5502 men with PSA levels of 2.5-10.0 ng/mL who underwent transrectal ultrasound-guided biopsy (TRUS-Bx) or MRI-TBx were reviewed. Participants were divided into four groups: LP-T [low PSA (2.5-4.0 ng/mL) and TRUS-Bx, n = 2018], LP-M (low PSA and MRI-TBx, n = 186), HP-T [high PSA (4.0-10.0 ng/mL) and TRUS-Bx, n = 2953], and HP-M (high PSA and MRI-TBx, n = 345). The detection rates of PCa and csPCa between groups were compared, and association of biopsy modality with detection of PCa and csPCa in men with low PSA levels were analyzed. The detection rates of PCa (20.0% vs. 38.2%; P < 0.001) and csPCa (11.5% vs. 32.3%; P < 0.001) were higher in the LP-M group than in the LP-T group. Conversely, there were no significant differences in the detection rates of PCa (38.2% vs. 43.2%; P = 0.263) and csPCa (32.3% vs. 39.4%; P = 0.103) between the LP-M and HP-M groups. Multivariate analyses revealed that using MRI-TBx could predict the detection of csPCa (odds ratio 2.872; 95% confidence interval 1.996‒4.132; P < 0.001) in men with low PSA levels. In summary, performing MRI-TBx in men with low PSA levels significantly improved the detection rates of PCa and csPCa as much as that in men with high PSA levels.

Photocurrent detection of chemically tuned hierarchical ZnO nanostructures grown on seed layers formed by atomic layer deposition.

We demonstrate the morphological control method of ZnO nanostructures by atomic layer deposition (ALD) on an Al2O3/ZnO seed layer surface and the application of a hierarchical ZnO nanostructure for a photodetector. Two layers of ZnO and Al2O3 prepared using ALD with different pH values in solution coexisted on the alloy film surface, leading to deactivation of the surface hydroxyl groups. This surface complex decreased the ZnO nucleation on the seed layer surface, and thereby effectively screened the inherent surface polarity of ZnO. As a result, a 2-D zinc hydroxyl compound nanosheet was produced. With increasing ALD cycles of ZnO in the seed layer, the nanostructure morphology changes from 2-D nanosheet to 1-D nanorod due to the recovery of the natural crystallinity and polarity of ZnO. The thin ALD ZnO seed layer conformally covers the complex nanosheet structure to produce a nanorod, then a 3-D, hierarchical ZnO nanostructure was synthesized using a combined hydrothermal and ALD method. During the deposition of the ALD ZnO seed layer, the zinc hydroxyl compound nanosheets underwent a self-annealing process at 150 °C, resulting in structural transformation to pure ZnO 3-D nanosheets without collapse of the intrinsic morphology. The investigation on band electronic properties of ZnO 2-D nanosheet and 3-D hierarchical structure revealed noticeable variations depending on the richness of Zn-OH in each morphology. The improved visible and ultraviolet photocurrent characteristics of a photodetector with the active region using 3-D hierarchical structure against those of 2-D nanosheet structure were achieved.

The effect of annealing ambient on the characteristics of an indium-gallium-zinc oxide thin film transistor.

In this study, the effects of different annealing conditions (air, O2, N2, vacuum) on the chemical and electrical characteristics of amorphous indium-gallium-zinc oxide (a-IGZO) thin film transistors (TFT) were investigated. The contact resistance and interface properties between the IGZO film and the gate dielectric improved after an annealing treatment. However, the chemical bonds in the IGZO bulk changed under various annealing atmospheres, which, in turn, altered the characteristics of the TFTs. The TFTs annealed in vacuum and N2 ambients exhibited undesired switching properties due to the high carrier concentration (>10(17) cm(-3)) of the IGZO active layer. In contrast, the IGZO TFTs annealed in air and oxygen ambients displayed clear transfer characteristics due to an adequately adjusted carrier concentration in the operating range of the TFT. Such an optimal carrier concentration arose through the stabilization of unstable chemical bonds in the IGZO film. With regard to device performance, the TFTs annealed in O2 and air exhibited saturation mobility values of 8.29 and 7.54 cm2/Vs, on-off ratios of 7.34 x 10(8) and 3.95 x 10(8), and subthreshold swing (SS) values of 0.23 and 0.19 V/decade, respectively. Therefore, proper annealing ambients contributed to internal modifications in the IGZO structure and led to an enhancement in the oxidation state of the metal. As a result, defects such as oxygen vacancies were eliminated. Oxygen annealing is thus effective for controlling the carrier concentration of the active layer, decreasing electron traps, and enhancing TFT performance.