scholarly journals TMOD-01. A PROGNOSTIC NOMOGRAM MODEL AND ONLINE SOFTWARE FOR PATIENTS WITH NEWLY DIAGNOSED LOWER-GRADE GLIOMAS

2021 ◽  
Vol 23 (Supplement_1) ◽  
pp. i35-i35
Author(s):  
Mingzhi Han
Keyword(s):  
Cox Regression ◽  
Molecular Subtype ◽  
Age At Diagnosis ◽  
Calibration Plot ◽  
Low Grade ◽  
Lower Grade ◽  
Newly Diagnosed ◽  
Who Grade ◽  
Cox Regression Analysis ◽  
Survival Probabilities

Abstract The nomogram represents a statistical model that incorporates multiple risk factors to estimate individualized survival probabilities. In this study, we developed a nomogram which provides an important tool for individulized survival predicition for newly diagnosed low-grade gliomas (LGG). A total number of 582 newly diagnosed LGG patients were included; the median age was 39.93 years and 42% were female. Cox regression analysis showed that younger age at diagnosis, WHO grade II vs. III, the IDHmut-codel vs. the IDHwt, and the IDHmut-non-codel vs. the IDHwt were significantly associated with better prognosis. The adjuvant treatment following surgery showed a trend towards improved survival. Subsequently, the nomogram to estimate 60-, 90-, and 120-month survival probabilities was established. Our data showed that the age at diagnosis was the largest contributor to patient survival, followed by molecular subtype, WHO grade, treatment and gender. The calibration plot showed that the observed and the nomogram predicted OS curves were well-aligned. In addition, we also validated our nomogram for LGG patients who received postsurgical adjuvant therapy through cross-validation and the calibration plot. Finally, we developed a free online tool for this nomogram (softwarewebsite:https://rrlnnomogram.shinyapps.io/LGG_Nom_Asian/). Overall, this model should be a useful tool for counseling patients in clinical practice including treatment decisions, follow-up, and prognosis.

scholarly journals The Role of Extent of Resection in IDH1 Wild-Type or Mutant Low-Grade Gliomas

Neurosurgery ◽  
2017 ◽  
Vol 82 (6) ◽  
pp. 808-814 ◽  
Author(s):  
Toral Patel ◽  
Evan D Bander ◽  
Rachael A Venn ◽  
Tiffany Powell ◽  
Gustav Young-Min Cederquist ◽  
...  
Keyword(s):  
Cox Regression ◽  
Extent Of Resection ◽  
World Health ◽  
Low Grade ◽  
Wild Type ◽  
Who Grade ◽  
Cox Regression Analysis ◽  
Low Grade Gliomas ◽  
Grade Ii ◽  
The Impact

Abstract BACKGROUND Maximizing extent of resection (EOR) improves outcomes in adults with World Health Organization (WHO) grade II low-grade gliomas (LGG). However, recent studies demonstrate that LGGs bearing a mutation in the isocitrate dehydrogenase 1 (IDH1) gene are a distinct molecular and clinical entity. It remains unclear whether maximizing EOR confers an equivalent clinical benefit in IDH mutated (mtIDH) and IDH wild-type (wtIDH) LGGs. OBJECTIVE To assess the impact of EOR on malignant progression-free survival (MPFS) and overall survival (OS) in mtIDH and wtIDH LGGs. METHODS We performed a retrospective review of 74 patients with WHO grade II gliomas and known IDH mutational status undergoing resection at a single institution. EOR was assessed with quantitative 3-dimensional volumetric analysis. The effect of predictor variables on MPFS and OS was analyzed with Cox regression models and the Kaplan–Meier method. RESULTS Fifty-two (70%) mtIDH patients and 22 (30%) wtIDH patients were included. Median preoperative tumor volume was 37.4 cm3; median EOR of 57.6% was achieved. Univariate Cox regression analysis confirmed EOR as a prognostic factor for the entire cohort. However, stratifying by IDH status demonstrates that greater EOR independently prolonged MPFS and OS for wtIDH patients (hazard ratio [HR] = 0.002 [95% confidence interval {CI} 0.000-0.074] and HR = 0.001 [95% CI 0.00-0.108], respectively), but not for mtIDH patients (HR = 0.84 [95% CI 0.17-4.13] and HR = 2.99 [95% CI 0.15-61.66], respectively). CONCLUSION Increasing EOR confers oncologic and survival benefits in IDH1 wtLGGs, but the impact on IDH1 mtLGGs requires further study.

scholarly journals Short-term outcomes associated with temozolomide vs. PCV chemotherapy for 1p/19q-codeleted WHO grade III anaplastic oligodendrogliomas: a national evaluation

2020 ◽  
Author(s):  
Nayan Lamba ◽  
Malia McAvoy ◽  
Vasileios K. Kavouridis ◽  
Timothy R. Smith ◽  
Mehdi Touat ◽  
...  
Keyword(s):  
Cox Regression ◽  
Long Term Results ◽  
National Database ◽  
Newly Diagnosed ◽  
First Line ◽  
Short Term ◽  
Who Grade ◽  
Cox Regression Analysis ◽  
Pcv Chemotherapy ◽  
Grade Iii

AbstractPURPOSEThe optimal chemotherapy regimen between temozolomide (TMZ) and procarbazine, lomustine, and vincristine (PCV) remains uncertain for newly-diagnosed anaplastic oligodendroglioma (AO). We therefore addressed this question using a national database.METHODSPatients newly-diagnosed with 1p/19q-codeleted W.H.O. grade III AO between 2010-2016 were identified from the National Cancer Database. Predictors of receiving first-line single-agent TMZ vs. multi-agent PCV were assessed by multivariable logistic regression. Overall survival (OS) was estimated by Kaplan-Meier techniques and evaluated by multivariable Cox regression.RESULTS1,360 AO patients were identified: 74.5% (n=1,013) treated with TMZ, 9.6% (n=131) with PCV, and 15.9% (n=216) with no chemotherapy in the first-line setting. In multivariable logistic analysis, PCV utilization increased from 2010 to 2016 (OR=1.38/year, 95%CI: 1.22-1.56, p<0.001) and was less commonly utilized in privately insured patients (OR=0.38 vs. uninsured, 95%CI: 0.15-0.97, p=0.04). In survival analyses (33.1% reached endpoint), there was no difference in unadjusted OS between TMZ (5yr-OS 60.1%, 95%CI: 55.9-64.1) and PCV (5yr-OS 61.1%, 95%CI: 45.6-73.5; p=0.42). There remained no OS difference between TMZ and PCV in the 75.9% (n=1,032) of AO patients that also received radiotherapy (p=0.51), in the Cox regression analysis adjusted by age, extent of resection, and radiotherapy (TMZ vs. PCV HR=1.31, 95%CI: 0.83-2.08, p=0.24), and in subgroup analyses that incorporate KPS or MGMT status.CONCLUSIONSIn a national database of AOs managed in the ‘real-world’ setting, there is no difference in the short-term mortality between first-line TMZ and PCV chemotherapy. These findings provide preliminary data while we await the long-term results from the CODEL trial.

scholarly journals Prognostic Significance and Gene Co-Expression Network of PLAU and PLAUR in Gliomas

2022 ◽  
Vol 11 ◽  
Author(s):  
Junhong Li ◽  
Huanhuan Fan ◽  
Xingwang Zhou ◽  
Yufan Xiang ◽  
Yanhui Liu
Keyword(s):  
Cox Regression ◽  
Prognostic Significance ◽  
High Expression ◽  
Lower Grade ◽  
Tumor Type ◽  
Who Grade ◽  
Cox Regression Analysis ◽  
Online Databases ◽  
Type Plasminogen Activator ◽  
Primary Glioma

The urokinase-type plasminogen activator(PLAU) and its receptor PLAUR participate in a series of cell physiological activities on the extracellular surface. Abnormal expression of PLAU and PLAUR is associated with tumorigenesis. This study aims to evaluate the prognostic value of PLAU/PLAUR transcription expression in glioma and to explore how they affect the generation and progression of glioma. In this study, online databases are applied, such as Oncomine, GEPIA, CGGA, cBioPortal, and LinkedOmics. Overexpression of PLAU/PLAUR was found to be significantly associated with clinical variables including age, tumor type, WHO grade, histology, IDH-1 mutation, and 1p19q status. PLAU and PLAUR had a high correlation in transcriptional expression levels. High expression of PLAU and PLAUR predicted a poor prognosis in primary glioma and recurrent glioma patients, especially in lower grade gliomas. Cox regression analysis indicated that high expression of PLAU and PLAUR were independent prognostic factors for shorter overall survival in glioma patients. In gene co-expression network analysis PLAU and PLAUR and their co-expression genes were found to be involved in inflammatory activities and tumor-related signaling pathways. In conclusion, PLAU and PLAUR could be promising prognostic biomarkers and potential therapeutic targets of glioma patients.

scholarly journals Clinical Implications of Girdin Protein Expression in Glioma

2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Liwei Zhao ◽  
Shuyin Ma ◽  
Qing Liu ◽  
Peng Liang
Keyword(s):  
Protein Expression ◽  
Cox Regression ◽  
Strong Predictor ◽  
Extent Of Resection ◽  
Biological Behavior ◽  
Low Grade ◽  
Who Grade ◽  
Cox Regression Analysis ◽  
The Relationship ◽  
Expression Status

Objective. To investigate the expression status of Girdin in glioma and the relationship between Girdin expression and the biological behavior of glioma.Materials and methods. The expression status of Girdin in glioma from 560 cases was evaluated by RT-PCR, Western Blot and immunohistochemistry. The relationship between Girdin expression and clinic-pathological parameters as well as prognosis was also studied.Results. The expression of Girdin in high grade glioma was significantly higher than low grade glioma. After universal analysis, the expression of Girdin protein is closely related to KPS score, extent of resection, Ki67 and WHO grade, but it was not related to sex and age. Finally, extent of resection, Ki67 and WHO grade were indentified to be related to the Girdin protein expression in logistic regression. Interestingly, we found that the expression of Girdin is significantly related to the distant metastasis of glioma. After COX regression analysis, KPS score, Extent of resection, Ki67, WHO grade as well as Girdin were observed to be independent prognostic factors.Conclusions. Girdin is differential expressed in the glioma patients and closely related to the biological behavior of Glioma. Finally, Girdin was found to be a strong predictor for the post-operative prognosis.

scholarly journals PANX2 and brain lower grade glioma genesis: A bioinformatic analysis

2021 ◽  
Vol 104 (2) ◽  
pp. 003685042110118
Author(s):  
XiaoXue Xu ◽  
YueHan Hao ◽  
Shuang Xiong ◽  
ZhiYi He
Keyword(s):  
Cox Regression ◽  
Atp Release ◽  
Underlying Mechanism ◽  
Bioinformatic Analysis ◽  
Receptor Interaction ◽  
Low Grade ◽  
Lower Grade ◽  
Cox Regression Analysis ◽  
Pathway Analyses ◽  
Vesicle Cycle

PANX2 forms large-pore channels mediating ATP release in response to physiological and pathological stimuli. Although PANX2 shows involvements in glioma genesis, the underlying mechanism remains unclear. PANX2 mRNA expression was analyzed via Oncomine and was confirmed via Gene Expression Profiling Interactive Analysis (GEPIA). The influence of PANX2 on overall survival (OS) of glioma was evaluated using LinkedOmics and further assessed through Cox regression analysis. The correlated genes with PANX2 acquired from LinkedOmics were validated through GEPIA and cBioPortal. Protein-protein interaction (PPI) of these genes was then obtained using Search Tool for the Retrieval of Interacting Genes (STRING) and Cytoscape with MCODE plug-in. All the PANX2-related genes underwent Gene Ontology (GO) enrichment and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses. The correlation between PANX2 and cancer immune infiltrates was evaluated via Tumor Immune Estimation Resource (TIMER). A higher expression of PANX2 only revealed a better OS in brain low grade glioma (LGG). PANX2-related genes in LGG functionally enriched in neuroactive ligand-receptor interaction, synaptic vesicle cycle, and calcium signaling. The hub genes from highest module of PPI were mainly linked to chemical synaptic transmission, plasma membrane, neuropeptide, and the pathway of neuroactive ligand-receptor interaction. Besides, PANX2 expression was negatively associated with infiltrating levels of macrophage, dendritic cells, and CD4+ T cells. This study demonstrated that PANX2 likely participated in LGG pathogenesis by affecting multiple molecular pathways and immune-related processes. PANX2 was associated with LGG prognosis and might become a promising therapeutic target of LGG.

scholarly journals MOMC-3. Hypermethylation and overexpression of HOX genes are poor prognosticators in Lower-Grade Glioma

2021 ◽  
Vol 3 (Supplement_2) ◽  
pp. ii4-ii4
Author(s):  
Yasin Mamatjan ◽  
Mathew Voisin ◽  
Farshad Nassiri ◽  
Fabio Moraes ◽  
Severa Bunda ◽  
...  
Keyword(s):  
Hox Genes ◽  
Cox Regression ◽  
The Cancer Genome Atlas ◽  
P Value ◽  
Low Grade ◽  
Lower Grade ◽  
Cox Regression Analysis ◽  
Hox Gene ◽  
Lower Grade Glioma ◽  
Diffuse Gliomas

Abstract Diffuse gliomas represent over 80% of malignant brain tumors ranging from low-grade to aggressive high-grade lesions. Molecular characterization of these tumors led to the development of new classification system comprising specific glioma subtypes. While this provides novel molecular insight into gliomas it does not fully explain the variability in patient outcome. To identify and characterize a predictive signature of outcome in diffuse gliomas, we utilized an integrative molecular analysis (methylation, mRNA, copy number variation (CNV) and mutation data) using multiple molecular platforms, including a total of 310 IDH mutant glioma samples from University Health Network (UHN) and German Cancer Research Center (DKFZ) together with 419 samples from The Cancer Genome Atlas (TCGA). Cox regression analysis of methylation data from the UHN cohort identified CpG-based signatures that split the glioma cohort into two prognostic groups strongly predicting survival (p-value &lt; 0.0001). The CpG-based signatures were reliably validated using two independent datasets from TCGA and DKFZ cohorts (both p-values &lt; 0.0001). The results show that the methylation signatures that predict poor outcome also correlated with G-CIMP low status, elevated CNV instability and hypermethylation of a set of HOX gene probes. Further study in diffuse lower-grade glioma (LGG) using integrated mRNA and methylation (iRM) analyses showed that parallel HOX gene overexpression and hypermethylation in the same direction were significantly associated with increased mutational load, high aneuploidy and worse survival (p-value &lt; 0.0001). Furthermore, this iRM high group was characterized by a 7-HOX gene signature showed significant survival differences not only in IDH mutant LGG but also in IDH wildtype LGG. These results demonstrate the importance of HOX genes in predicting the outcome of diffuse gliomas to identify relevant molecular subtyping independent of histology.

scholarly journals Immune-Related Gene SERPINE1 Is a Novel Biomarker for Diffuse Lower-Grade Gliomas via Large-Scale Analysis

2021 ◽  
Vol 11 ◽  
Author(s):  
Xiaoming Huang ◽  
Fenglin Zhang ◽  
Dong He ◽  
Xiaoshuai Ji ◽  
Jiajia Gao ◽  
...  
Keyword(s):  
Regression Analysis ◽  
Immune Cell ◽  
Cox Regression ◽  
Expression Patterns ◽  
Critical Role ◽  
Lower Grade ◽  
Hub Genes ◽  
Who Grade ◽  
Primary Tumors ◽  
Cox Regression Analysis

BackgroundGlioma is one of the highly fatal primary tumors in the central nervous system. As a major component of tumor microenvironment (TME), immune cell has been proved to play a critical role in the progression and prognosis of the diffuse lower-grade gliomas (LGGs). This study aims to screen the key immune-related factors of LGGs by investigating the TCGA database.MethodsThe RNA-sequencing data of 508 LGG patients were downloaded in the TCGA database. ESTIMATE algorithm was utilized to calculate the stromal, immune, and ESTIMATE scores, based on which, the differentially expressed genes (DEGs) were analyzed by using “limma” package. Cox regression analysis and the cytoHubba plugin of Cytoscape software were subsequently applied to screen the survival-related genes and hub genes, the intersection of which led to the identification of SERPINE1 that played key roles in the LGGs. The expression patterns, clinical features, and regulatory mechanisms of SERPINE1 in the LGGs were further analyzed by data mining of the TCGA database. What’s more, the above analyses of SERPINE1 were further validated in the LGG cohort from the CGGA database.ResultWe found that stromal and immune cell infiltrations were strongly related to the prognosis and malignancy of the LGGs. A total of 54 survival-related genes and 46 hub genes were screened out in the DEGs, within which SERPINE1 was identified to be significantly overexpressed in the LGG samples compared with the normal tissues. Moreover, the upregulation of SERPINE1 was more pronounced in the gliomas of WHO grade III and IDH wild type, and its expression was correlated with poor prognosis in the LGG patients. The independent prognostic value of SERPINE1 in the LGG patients was also confirmed by Cox regression analysis. In terms of the functions of SERPINE1, the results of enrichment analysis indicated that SERPINE1 was mainly enriched in the immune‐related biological processes and signaling pathways. Furthermore, it was closely associated with infiltrations of immune cells in the LGG microenvironment and acted synergistically with PD1, PD-L1, PD-L2.ConclusionThese findings proved that SERPINE1 could serve as a prognostic biomarker and potential immunotherapy target of LGGs.

390 The Impact of Extent of Resection on IDH1 Wild-Type or Mutant Low-Grade Gliomas

Neurosurgery ◽  
2017 ◽  
Vol 64 (CN_suppl_1) ◽  
pp. 293-294 ◽  
Author(s):  
Toral R Patel ◽  
Evan D Bander ◽  
Rachael A Venn ◽  
Tiffany L Powell Avila ◽  
Gustav Y Cederquist ◽  
...  
Keyword(s):  
Regression Analysis ◽  
Cox Regression ◽  
Extent Of Resection ◽  
Low Grade ◽  
Wild Type ◽  
Who Grade ◽  
Cox Regression Analysis ◽  
Grade Ii ◽  
The Impact ◽  
Who Grade Ii Gliomas

Abstract INTRODUCTION Accumulating evidence suggests that maximizing extent of resection (EOR) improves outcomes for patients with WHO grade II low-grade gliomas (LGG). However, recent studies demonstrate that LGGs bearing a mutation in the isocitrate dehydrogenase 1 (IDH1) gene are a distinct molecular and clinical entity. It remains unclear whether maximizing EOR confers an equivalent clinical benefit in IDH mutated (mtIDH) and IDH wild-type (wtIDH) LGGs. To answer this question, we evaluated a cohort of patients with surgically-resection WHO grade II gliomas and known IDH1 mutation status, to assess the impact of EOR on malignant progression-free survival (MPFS) and overall survival (OS). METHODS We performed a retrospective review of 74 patients with WHO grade II gliomas and known IDH mutational status undergoing surgical resection at a single institution. EOR was assessed with quantitative three-dimensional volumetric analysis. The effect of predictor variables on MPFS and OS was analyzed with Cox regression models and the Kaplan-Meier method. RESULTS >52 (70%) mtIDH patients and 22 (30%) wtIDH patients were included. Median pre-operative tumor volume was 37.4 cm3 (range: 0.9-190.2 cm3). Median EOR was 57.6% (range: 0.08% 99.3%). Median follow-up was 44.4 months. Malignant progression was identified in 31 patients and 17 patients died. Univariate Cox regression analysis confirmed EOR as a prognostic factor for the entire cohort. However, Cox regression analysis stratified by IDH status demonstrated that a greater EOR independently prolonged MPFS and OS for wtIDH patients (HR = 0.002 [95% CI 0.000 - 0.074] and HR = 0.001 [95% CI 0.00 - 0.108], respectively), but not for mtIDH patients (HR = 0.84 [95% CI 0.17 - 4.13] and HR = 2.99 [95% CI 0.15 - 61.66], respectively). CONCLUSION Increasing EOR confers oncologic and survival benefits in IDH1 wild-type LGGs. However, the impact of EOR on IDH1 mutant LGGs is less significant and requires further study.

scholarly journals A prognostic signature for lower-grade gliomas based on expression of long noncoding RNAs

2018 ◽  
Author(s):  
Manjari Kiran ◽  
Ajay Chatrath ◽  
Xiwei Tang ◽  
Daniel Macrae Keenan ◽  
Anindya Dutta
Keyword(s):  
Epithelial To Mesenchymal Transition ◽  
Cox Regression ◽  
Association Studies ◽  
Primary Brain Tumor ◽  
Low Grade ◽  
Lower Grade ◽  
Who Grade ◽  
Mesenchymal Transition ◽  
Diagnosis And Prognosis ◽  
Grade Ii

AbstractDiffuse low-grade and intermediate-grade gliomas (together known as lower-grade gliomas, WHO grade II and III) develop in the supporting glial cells of brain and are the most common types of primary brain tumor. Despite a better prognosis for lower-grade gliomas, 70% of patients undergo high-grade transformation within 10 years, stressing the importance of better prognosis. Long non-coding RNAs (lncRNAs) are gaining attention as potential biomarkers for cancer diagnosis and prognosis. We have developed a computational model, UVA8, for prognosis of lower-grade gliomas by combining lncRNA expression, Cox regression and L1-LASSO penalization. The model was trained on a subset of patients in TCGA. Patients in TCGA, as well as a completely independent validation set (CGGA) could be dichotomized based on their risk score, a linear combination of the level of each prognostic lncRNA weighted by its multivariable cox regression coefficient. UVA8 is an independent predictor of survival and outperforms standard epidemiological approaches and previous published lncRNA-based predictors as a survival model. Guilt-by-association studies of the lncRNAs in UVA8, all of which predict good outcome, suggest they have a role in suppressing interferon stimulated response and epithelial to mesenchymal transition. The expression levels of 8 lncRNAs can be combined to produce a prognostic tool applicable to diverse populations of glioma patients. The 8 lncRNA (UVA8) based score can identify grade II and grade III glioma patients with poor outcome and thus identify patients who should receive more aggressive therapy at the outset.

scholarly journals PATH-37. PROGNOSTIC ROLE OF TERT PROMOTER MUTATIONS IMPROVES THE STRATIFICATION OF IDH-MUTATED LOWER GRADE GLIOMA

2019 ◽  
Vol 21 (Supplement_6) ◽  
pp. vi151-vi151
Author(s):  
Hideyuki Arita ◽  
Yuko Matsushita ◽  
Makoto Ohno ◽  
Yohei Miyake ◽  
Kuniaki Saito ◽  
...  
Keyword(s):  
Overall Survival ◽  
Cox Regression ◽  
Molecular Diagnostic ◽  
Lower Grade ◽  
Tert Promoter Mutation ◽  
Promoter Mutation ◽  
Who Grade ◽  
Cox Regression Analysis ◽  
Tert Promoter ◽  
Grade Ii

Abstract TERT promoter mutation is associated with 1p/19q codeletion and favorable prognosis in IDH-mutated gliomas. Prognostic and diagnostic significance of TERT promoter mutation is well-recognized in IDH-wildtype glioblastomas, but not in IDH-mutated gliomas. We investigated prognostic efficacy of TERT mutation in a cohort of 560 Japanese IDH-mutated adult gliomas. The molecular status of IDH, TERT and 1p/19q and patient clinical data including Karnofsky performance status (KPS) were collected in all cases. TERT mutations and 1p/19q codeletions were found in 303 and 285 cases, respectively. The patient cohort was divided into four groups by a combination of the 1p/19q and TERT status. The characteristics of 1p/19q intact-TERT mutated group (Astro-TERT group, n=24) were compared with those of 1p/19q intact-TERT wild (Astro-group, n=251) or 1p/19q codeleted-TERT mutated (Oligo-group, n=279) cases. Astro-TERT group with any grade showed intermediate overall survival between the Oligo-group and Astro-group although the survival differences were not statistically significant (median overall survival (OS) not reached (NR) versus NR, and 106 months, respectively. p >0.05). We further conducted subgroup analysis by adjusting KPS and WHO grade as Cox regression analysis for survival indicated the unfavorable survival impact of KPS < 90 and WHO grade IV. In the subgroup with favorable KPS (90–100) and grade II-III (n=438), The OS of Astro-TERT group (median NR) was significantly longer survival than that of Astro-group (median 120.2 months, p=0.032), and was comparable with that of the Oligo-group (median NR, p >0.05). On the other hand, OS of none of the molecular groups significantly differ in poorer KPS subgroups (p >0.05). In grade IV tumors, the OS of the Astro-TERT group (NR) was comparable with that of Astro-group (29 months, p=0.19) rather than Oligo-group (NR, p=0.051). Thus, TERT promoter status provides a valuable prognostic information for IDH-mutated grade II-III gliomas in the current molecular diagnostic system.

Sign in / Sign up

Export Citation Format

Share Document