Report of a collaborative study to establish the first Indian Pharmacopoeia reference standard for teriparatide.

A collaborative study was conducted to establish the first Indian Pharmacopoeia Reference Standard (IPRS) for teriparatide to be used in quality control testing of marketed products in compliance with the Indian Pharmacopoeia (IP) monograph. The study objective was to evaluate the candidate standard in terms of the WHO International Standard (IS) to assign its content in mg per vial terms. This study involved four laboratories from India and the candidate standard was calibrated against the WHO IS by each participant laboratory using high-performance liquid chromatography (HPLC) assay method per IP monograph. Direct calibration of the candidate standard resulted in an assigned content of 1.02 mg per vial. Based on the study results the candidate standard was judged suitable to serve as the first IPRS for teriparatide for identification and assay by HPLC.

A novel EML4-NTRK3 fusion in lung adenocarcinoma with dramatic response to entrectinib.

ABSTRACT: In-frame fusions in NTRK genes, with intact kinase domain, have been reported to occur at higher frequencies in rare tumors like infantile fibrosarcoma, congenital mesoblastic nephroma, and secretory carcinoma, whereas they occur at very low frequencies in common malignancies like NSCLC and colon cancers (0.1%-1%). Despite the rare occurrence, these alterations have gained importance owing to approval of drugs like entrectinib and larotrectinib targeting the kinase domain of the gene. More than 50 fusion partners have been described, and only in-frame fusions result in constitutive ligand-independent kinase activity leading to oncogenesis. The commonly reported NTRK fusions in the lung include SQSTM1-NTRK1, ETV6-NTRK3, and SQSTM1-NTRK3. Detection of these rests on the use of conventional modalities like Immunohistochemistry (IHC) and fluorescence in situ hybridization (FISH); however, accurate characterization requires direct sequencing methods. We report an interesting case of an NTRK fusion-positive NSCLC, exhibiting good response to entrectinib.

Clinical and Epidemiological Profile of Elderly Hodgkin's Lymphoma in India.

Background Hodgkin's lymphoma (HL) is a curable malignancy that commonly involves the younger population. However, HL can rarely occur in the elderly population (≥60 years) and probably has different biology as compared to the younger counterparts. There was a paucity of data on the clinical and epidemiological profile of the elderly subset with HL in Indian patients who are misdiagnosed and empirically treated as tuberculosis. We have done an analysis of this subset of elderly patients who were registered at our institute. Methods A retrospective chart analysis of HL patients who presented to our center from 2008 to 2016 was conducted. Twenty-eight patients with HL of age ≥60 years were included in this study. Results Elderly HL comprised 18.67% of the total HL patients registered during this period. The majority were male patients, and the mean age of presentation was 65.9±5.6 years. A Charlson Comorbidity Index (CCI) of ≥2 was seen in 30.77% of the patients. Among these, 84.62% of the patients presented with advanced-stage disease, and 57.69% of the patients presented with B symptoms, which was significantly associated with a high-risk international prognostic score (IPS). Histology-wise, mixed cellularity classical Hodgkin's lymphoma (MCCHL) and nodular sclerosis classical Hodgkin's lymphoma (NSCHL) were equally represented (30.76%). Of the patients, 50% had extranodal disease, with the liver being the most frequent site involved. One patient each had bone marrow involvement and bulky disease. CD30, CD15, and CD20 positivity was seen in 84.61%, 50%, and 26.92% of cases, respectively. Conclusion Among elderly HL patients, males were more commonly represented than females, and patients more often presented with advanced disease and B symptoms and less often with bulky disease and mediastinal mass. Mixed cellularity classical HL is more common in the elderly subset, and significant comorbidities are present in a higher number of elderly HL patients.

Ramucirumab in Indian Patients with Advanced Gastric Cancer-Does Borderline Performance Status and Heavy Burden of Disease in Real World Practice Impact Clinical Benefit?

Vikas OstwalBackground Ramucirumab is considered a standard of care as second-line therapy (CT2) in advanced gastric cancers (AGCs). The aim of this study was to assess practice patterns and outcomes with ramucirumab among Indian patients with AGCs. Materials and Methods A computerized clinical data entry form was formulated by the coordinating center's (Tata Memorial Hospital) medical oncologists and disseminated through personal contacts at academic conferences as well as via email for anonymized patient data entry. The data was analyzed for clinical characteristics, response rates, and survival outcomes. Results A total of 26 physicians contributed data, resulting in 55 patients receiving ramucirumab and being available for analysis. Median age was 53 years (range: 26-78), 69.1% of patients had greater than two sites of disease, and baseline Eastern Cooperative Oncology Group's performance score (ECOG PS) ≥ 2 was seen in 61.8% of patients. Ramucirumab was used as monotherapy in 10.9% of patients, while the remaining 89.1% received ramucirumab combined with chemotherapy. Median event-free survival (EFS) and median overall survival (OS) with ramucirumab were3.53 months (95% CI: 2.5-4.57) and 5.7 months (95% CI: 2.39-9.0), respectively. Common class specific grade adverse events seen with ramucirumab included gastrointestinal (GI) hemorrhage (9.1% - all grades) and uncontrolled hypertension (Grade 3/4 - 3.6%). Conclusions Ramucirumab appears to have similar efficacy in Indian AGC patients when compared with real-world data from other countries in terms of median EFS, but OS appears inferior due to more patients having borderline ECOG PS and high metastatic disease burden. GI hemorrhages appear more common than published data, although not unequivocally related to ramucirumab.

Molecular Response Assessment with Immune Adaptive PERCIST in Lung Cancer Patients Treated with Nivolumab: Is It Better Than iRECIST?

Aims We compared the immune response evaluation criteria in solid tumors (iRECIST) with immune adaptive positron emission tomography response criteria in solid tumors (imPERCIST) in lung cancer patients treated with nivolumab. Materials and Methods Twenty lung cancer patients underwent fluorodeoxyglucose positron emission tomography/computed tomography (FDG PET/CT) scan at baseline (PET-0), after four cycles (PET-1) and six to eight cycles (PET-2) of nivolumab were included. Kappa coefficient ( k ) was derived to see the level of agreement in two response criteria. Progression-free survival (PFS) curves were computed by the Kaplan-Meier method and compared with the Log Rank test. Univariate and multivariate regression for the percentage change in the sum of diameters (SoD), standard uptake value maximum (SUVmax), sum of metabolic tumor volume (SoMTV), and sum of total lesion glycolysis (SoTLG) was computed. A p -value less than 0.05 was considered significant. Results Kappa coefficient showed a substantial level of agreement (k 0.769) in two response criteria. Mean PFS in partial response, stable disease, and progressive disease (PD) patients in iRECIST and imPERCIST was 27.3, 17.7, 4.2, and 23.3, 18.8, 3.8 months, respectively. The Kaplan-Meier method with the log rank test showed a significant difference in PFS on intracomparison within both criteria; however, it was not significant on intercomparison. On univariate analysis, the percentage change in SoD, SoMTV, SoTLG was significant. However, on multivariate analysis, only percentage change in SoD was a significant predictor. Conclusions We concluded that imPERCIST was equally effective as currently recommended criteria iRECIST for response evaluation of nivolumab in lung cancer patients.

EGFR detection by liquid biopsy: ripe for clinical usage.

Introduction: With the International Association for the Study of Lung Cancer (IASLC) recommendations promoting liquid biopsy as a primary detection tool, a new era of research has begun. The authors aimed to study the concordance of plasma genotyping platforms against the tissue gold standard. Methods: 184 patients with non-small cell lung cancer underwent EGFR genotyping using Cobas, droplet digital polymerase chain reaction (ddPCR) and Therascreen assays from 2019-2020. Results: Of 184 cases, 70 were positive by Cobas, 51 by ddPCR and 69 by Therascreen. The sensitivity of Cobas was 97.1% and the sensitivity of ddPCR was 71%. Receiver operating characteristic analysis showed an area under the curve of 0.977 for Cobas and 0.846 for ddPCR. Conclusion: In line with the FLAURA trial of osimertinib making its way to first-line and given the IASLC recommendations, it is important to understand the attributes of these tests to initiate appropriate treatment.

Lay abstract Lung cancer is one of the most common malignancies and has been known to have a dismal outcome. However, owing to evolution in the knowledge of disease biology and processes, many molecules have been discovered that can be used in targeted therapy. To institute this modality of treatment, detection of alterations in these specific molecules, namely: EGFR, ALK, ROS1, RET, MET, KRAS G12C, BRAF V600E, NTRK1, NTRK2, NTRK3 and ERBB2 is necessary. This has traditionally been done using single-gene assays, which require more tissue. This is a major limitation in cases of non-small cell lung carcinoma, as the biopsies are small. Hence, new technologies like next-generation sequencing have emerged that offer a one-stop solution for these cases. In cases where tissue is very scant, the use of peripheral blood has now been recommended by international guidelines for primary detection of these molecular alterations. This article describes the concordance of tissue-based detection and blood-based detection using three different assays, for the detection of EGFR alterations. Although promising results were obtained largely for blood-based assays, liquid and tissue biopsies are complementary.

Next generation sequencing for detection of EGFR alterations in NSCLC: is more better?

AIMS: The emergence of sophisticated next generation sequencing (NGS) based technologies in routine molecular diagnostics has paved the way for robust and accurate detection of variants which may otherwise be missed on single gene testing. This study aims at highlighting the same premise in EGFR mutated non-small cell lung carcinoma (NSCLC). METHODS: 1350 cases of NSCLC were screened, of which 490 EGFR mutated cases were taken. The clinical records and molecular features were evaluated retrospectively to determine those cases which were missed on single gene testing. RESULTS: Among these 490 cases, there were 11 (2.2%) cases which tested negative on single gene testing using polymerase chain reaction (therascreen). These were then subjected to NGS based testing and were positive for 13 different EGFR mutations. Five out of the 11 cases received EGFR tyrosine kinase inhibitor (TKI) based on the NGS test outcome. Four cases with exon 20 insertion mutations were not offered TKI as these mutations are known to be intrinsically resistant to TKI therapy. The five patients who have been treated with TKI have shown fair response and have not progressed to date. CONCLUSIONS: We demonstrated a potentially preferable way to profile treatment-naïve patients with NSCLC by NGS and from our early experience in EGFR mutant cases, the advantages of NGS over single gene testing is clearly evident.

IHC versus FISH versus NGS to detect ALK gene rearrangement in NSCLC: all questions answered?

AIMS: Anaplastic lymphoma kinase (ALK) rearranged non-small cell lung carcinoma (NSCLC) is a distinct molecular subtype and rapid approval of ALK tyrosine kinase inhibitors (TKIs) has necessitated rapid and sensitive diagnostic modalities for the detection of this alteration. Gene rearrangements can be identified using many techniques including fluorescence in situ hybridisation (FISH), reverse transcriptase-PCR, next-generation sequencing (NGS) and immunohistochemistry (IHC) for fusion oncoprotein expression. We aimed to determine the concordance between IHC, FISH and NGS for ALK biomarker detection, and determine differences in sensitivity, and survival outcomes. METHODS: We analysed the concordance between IHC using D5F3 monoclonal antibody, FISH (break-apart) and NGS using a custom panel containing 71 different ALK variants. RESULTS: Among 71 cases included in this study, FISH was evaluable in 58 cases. The concordance of ALK IHC with FISH was 75.9% and that with NGS was 84.5%. The sensitivities of FISH and NGS were 75.6% and 87.5%, respectively. The median progression-free survival of ALK IHC-positive and FISH-negative group was 5.5 months and that of both positive was 9.97 months. CONCLUSION: Although NGS offers a better throughput and visualisation, IHC still remains the quintessential screening tool in upfront diagnosis of ALK rearranged NSCLC.

Are all ALK variants created equal? Clinicopathologic features and outcomes: a propensity-matched study.

Anaplastic lymphoma kinase (ALK) rearranged NSCLC comprises a molecularly distinct subgroup occurring in 10% cases. Various EML4-ALK and non EML4 variants are known to occur which can be detected only on NGS and show differential TKI responses. 113 ALK-IHC positive cases were subjected to a custom panel-based NGS for detection of ALK variants. Clinicopathologic features and outcomes were studied and propensity-matched analysis was done. The median age of the overall cohort was 53 years. 91 (80.5%) cases were NGS positive, the most common being EML4-ALK (90, 98.9%) cases. The most common EML4 variant was Variant 1 (40, 35%) cases, Variant 3 (28, 25%) cases, and Variant 2 (17, 15%) cases. One novel EML4-ALK variant was also encountered which was found to be intrinsically resistant to crizotinib. On pre-weight-adjusted comparison, Variant 1 group had a higher occurrence of brain and extrathoracic metastases. The median OS was 44 months for the entire cohort. 49 patients received crizotinib as first-line TKI. Among these, the median OS for Variant 2 was not reached; it was 38 months and 24 months for Variant 1 and Variant 3, respectively. The median PFS for crizotinib treated patients was 8.3 months (Variant 2: 11 months, Variant 1: 8 months, and Variant 3: 9 months). On propensity-matched analyses, there was no difference in OS and PFS between Variant 1 and Variant 3, with higher HR for Variant 3. We present a large data set evaluating clinical and outcome differences between ALK variants. The unique standpoint of this study involves the propensity-weighted model to account for differences among the groups, with no prognostic differences between Variant 1 and Variant 3, which is distinct from literature.

Adjuvant chemotherapy in uterine carcinosarcoma: Comparison of a doublet and a triplet chemotherapeutic regimen.

BACKGROUND: Uterine carcinosarcoma (UCS) is a rare and aggressive malignancy, and there are no existing standard guidelines for adjuvant therapy. Doublet chemotherapy regimens are most favored in adjuvant setting; however, given the early chances of distant recurrences, does a triple-drug adjuvant chemotherapy improve disease-free survival (DFS), remains to be seen. Our aim of the study is to compare and review different adjuvant regimens used in UCS. METHODS: Retrospective chart analysis included 37 optimally staged UCS patients. Each of them had either received paclitaxel plus carboplatin (PC) or paclitaxel, ifosfamide, and cisplatin (TIP). A toxicity analysis was charted as per common terminology criteria for adverse events (CTCAE) 4 criteria. A survival analysis was done by the Kaplan-Meier method, and log-rank test was used for comparison of two variables. RESULTS: Incidence of UCS was 4.1% and mean age (standard deviation) was 58.73 ± 6.3 (range 42 - 71) years. TIP and PC chemotherapies were given to 22 and 15 patients, respectively. Five-year DFS and overall survival for TIP versus PC were 38.2% versus 35.9% (P = 0.118) and 49% versus 50.3% (P = 0.306), respectively, and for Stage I, II versus Stage III was 78.8% versus 12.7%(P = 0.001) and 92.3% versus 34.2% (P = 0.002), respectively. However, in advanced disease (Stage III), there is a trend toward DFS advantage of triple-drug adjuvant regimen (Hazards ratio (HR) = 0.35, 95% confidence interval (CI) = 0.12-1.07). Grade 3 and 4 toxicities were seen in 54.5% patients of TIP chemotherapy group and in 13.3% patients of the PC chemotherapy (P = 0.012). CONCLUSION: Triple-drug adjuvant chemotherapy (TIP) confers no survival advantage over doublet chemotherapy (PC), and in turn, increases the grade 3/4 toxicity in the adjuvant setting of optimally staged UCS patients.

EGFR and PDL1: A Match (Not) Made in Heaven-A Real-World Retrospective Analysis of PDL1 Expression in EGFR-Mutated NSCLC.

INTRODUCTION: EGFR (epidermal growth factor receptor) mutant NSCLC (non-small cell lung carcinoma) comprises 35-40% of cases in the Asian NSCLC cohort, compared to 15-20% in the rest of the world. Improved response rates have been observed in terms of PFS (progression-free survival) and ORR (overall response rate) when treated with EGFR TKIs (tyrosine kinase inhibitors). However, resistance eventually ensues regardless of the generation of TKI used. Preclinical studies have reported that PDL1 (programmed death ligand 1) is a downstream target of EGFR and is interposed by IL-6/JAK/STAT3 (interleukin-6/Janus kinase/signal transducer and activator of transcription 3), NF-κB (nuclear factor kappa beta), and p-ERK1/2/p-c-Jun pathways. Hence, it may potentially be repressed by EGFR TKIs. In this retrospective exploratory analysis, we studied whether PDL1 expression affects efficacy of EGFR TKIs and clinical outcome in patients with untreated metastatic EGFR-mutated lung adenocarcinoma. METHODS: This single-center retrospective, exploratory analysis was performed between January 2015 and December 2019. Among 1350 cases of NSCLC, 470 were EGFR mutant, of which PDL1 expression testing was done in 193 patients who were included in this study. RESULTS: Median age was 60 years (range 24-87 years). A total of 116 patients (60.1%) had inframe deletion in exon 19, 52 (26.9%) had L858R, and 25 (13%) had uncommon mutations. The number of patients with PDL1 tumour proportion score (TPS) < 1% was 109 (56.5%); 1-49%, 57 (29.5%); and ≥ 50%, 27 (14%). Comparing clinical characteristics among various PDL1 groups, there were no statistically significant correlations obtained. However, patients with PDL1 > 50% were smokers, and showed a trend for higher disease burden at diagnosis. Median PFS of PDL1 < 1% was 10.14 months, compared to 9.4 months in the PDL1 > 1% group; however, the values did not reach statistical significance. CONCLUSION: The current study was an exploratory retrospective study; however, the results add to the growing body of evidence that PDL1 expression in EGFR-mutated NSCLC does not have any prognostic significance. Also the efficacy of EGFR TKIs is not influenced by variations in PDL1 TPS.

A Walk with Lu-177 PSMA: How Close we Have Reached from Bench to Bedside?

Metastatic castration-resistant prostate cancer (mCRPC) is a natural sequela in advanced prostate cancer following resistance to standard treatment regimes, where patients develop with rising PSA, bone pains, and high disease volume. Further palliative treatment is the need of the hour for ensuring disease control and quality of life. In recent times, many novel methods have been evolved for these patients. Endo-radioligand therapy with Lutetium 177 prostate-specific membrane antigen 617 (Lu-177 PSMA) based on the Theranostic concept has emerged as a promising tool among these. We present here the current status of Lu177-PSMA for mCRPC patient and future directions.

Role of 18F-Flurodeoxyglucose Positron-Emission Tomography/Computed Tomography in the Evaluation of Early Response to Neoadjuvant Chemotherapy in Patients with Locally Advanced Triple-Negative Breast Cancer.

BACKGROUND: Response evaluation in locally advanced breast cancer is done through different methods ranging from clinical examination to magnetic resonance imaging, however evaluation with positron-emission tomography/computed tomography (PET/CT) in now being incorporated for the response evaluation. The aim of the present study is to correlate response to neoadjuvant chemotherapy (NACT) with PET/CT scan. MATERIALS AND METHODS: The present study is a retrospective analysis of 30 locally advanced, triple-negative breast cancer patients. PET/CT scan was done pretreatment and post three and six cycles of NACT and was correlated with pathologic complete response (pCR). Responding disease was considered when there was at least a 50% reduction in the longest diameter. RESULTS: The median pretreatment size of the breast lesion in CT scan was 3.9 ± 2.3 cm (2-12 cm) and maximum standardized uptake value (SUVmax) on PET/CT was 8.5 ± 5.5 (2.9-24). Among the responders, the median decrease in size of lesion was 3.2 ± 1.3 cm and median reduction in SUV of the tumor among was -8.1 ± 5.4 and was statistically significant when compared with nonresponders (P < 0.001). CT scan has 66% accuracy and PET has 82% accuracy at post three cycles NACT in predicting the pathological response. PET/CT had higher sensitivity and specificity when compared with CT findings alone in response evaluation. CONCLUSION: PET/CT scan can be considered as a sensitive tool for predicting pCRs and further larger trials are required to establish these findings.

Real world experience of treatment and outcome in ALK-rearranged metastatic nonsmall cell lung cancer: A multicenter study from India.

BACKGROUND: Anaplastic lymphoma kinase (ALK) rearranged metastatic non-small cell lung cancer (NSCLC) comprises 5%-7% of all lung cancer and carries a good prognosis with available ALK-inhibitors. Majority of registration trials in ALK-inhibitors did not include Indian patients. Hence, this study was planned to analyze the outcome of Indian patients treated with ALK-inhibitors and associated challenges. METHODS: This is a multi-center study in 5 major tertiary care cancer centers across India treating ALK-rearranged NSCLC patients from April 2013 to April 2019. ALK rearrangement was determined by Ventana immunohistochemistry with D5F3 clone and/or by break-apart FISH. Patients treated with ALK-inhibitors in any lines of treatment were included in this study. Patients were evaluated for clinicopathologic features, patterns of ALK-inhibitors use and outcome. Progression free-survival (PFS) and overall survival (OS) were calculated and data were censored on April 30, 2019. RESULTS: A total of 274 patients were studied, out of which 250 patients received ALK inhibitor and were analyzed further for outcome. The median age was 50 years (range: 24-82) and male to female ratio of 1.17:1. ALK was evaluated by immunohistochemistry in majority of patients (97%), 3 patients by FISH and 3 more patients were evaluated by both methods. Sixty-five percent (n = 162) of the patients received ALK-inhibitor as first line therapy, 51 patients received ALK-inhibitor as switch maintenance therapy after initial chemotherapy. Crizotinib and Ceritinib were used in 88% and 12%, respectively. One patient received Alectinib. Forty-one percent of patients had CNS progression. After median follow up of 27 months (1-72 months), the median OS was 24.7 months with OS rate of 72%, 51%, and 18% at 1, 2, and 4-years respectively. Median OS was 21.2, 26, and 38 months in the first line ALK-inhibitors use (n = 162), switch maintenance group (n = 51) and second line ALK-inhibitors use (postchemotherapy progression) (n = 33), respectively. No baseline variable predicted PFS. Presence of brain metastasis (P = 0.039) and first line ALK-inhibitors use (P = 0.032) emerged as poor prognostic factor for OS on multivariate analysis. PFS rate was 70%, 47%, and 31% at 6, 12, and 18 months respectively. CONCLUSION: This is one of the largest real-world data on outcome of ALK inhibitors in ALK-rearranged NSCLC from Asia. In absence of second line ALK inhibitor, initial chemotherapy followed by ALK-inhibitors (switch maintenance) had better outcome. This fact may be studied in individual patient data meta-analysis. Poor performance status and brain metastases at presentation are poor prognostic factors for overall survival. Second-line ALK inhibitor use crucial for better outcome and access to clinical trials are much needed in Indian patients.

Efficacy and tolerability of nimotuzumab in combination with chemotherapy in recurrent and metastatic squamous cell carcinoma of head and neck at a cancer center in Northern India.

INTRODUCTION: Squamous cell carcinoma of head and neck (SCCHN) account for approximately 30-33% of all cancer and the median survival for recurrent and metastatic(R/M) SCCHN remains less than 1 year despite modern advances in therapy. Chemotherapy, usually single agent remains the backbone of therapy in these patients. EGFR antibodies are being used in (R/M) SCCHN. Nimotuzumab is one such agent that has anti-EGFR action similar to other agents without similar skin toxicity. METHODS: Prospective, interventional, non-randomized study done at Rajiv Gandhi Cancer Institute and Research Centre. A total 124 patients were enrolled and divided into Arm A (Chemotherapy + Nimotuzumab) and Arm B (Chemotherapy) in a ratio of 1:1 i.e., 62 in each arm. They were evaluated and treated as per protocol after a written informed consent. Statistical analysis was done using the SPSS software. Quantitative variables were compared using Unpaired t-test/Mann-Whitney Test. Qualitative variables were compared using Chi-Square test /Fisher's exact test. Kaplan-Meier analysis was used to assess the PFS, with log rank test for comparison between the groups. A p value of < 0.05 was considered statistically significant. RESULTS: The most frequent primary location of tumor was oral cavity (n=38, 69%) and (n=33, 56.9%) in both arms. The overall response rate in Arm A was 38.2% and 19% in Arm B (p= 0.023). The disease control rate in Arm A was 74.5% and 43.1% Arm B (p= 0.0007). The median PFS in Arm A was 5.2 months whereas it was 3.2 months in Arm B (p= 0.009). CONCLUSION: In this study, the combination of Nimotuzumab plus platinum/taxane based chemotherapy was active and well tolerated in Indian patients in R/M SCCHN. Addition of Nimotuzumab to chemotherapy had a response rate of 38.2% and median PFS of 5.2 months are strong arguments for clinically testing this combination.

Synthesis of Highly Transparent Indium Tin Oxide Thin Films Using Vacuum Evaporation Technique.

The synthesis of thin films of ITO (Indium Tin Oxide) is synthesized by thermal evaporation technique under high vacuum conditions and further annealing at different conditions of temperature. These films were further characterized by using SEM, XRD, AFM, photoluminescence spectroscopy and UV-Visible in order to understand the structural and optical properties associated with them. Parameters to synthesize uniform, homogeneous, single phase and highly transparent ITO thin films have been optimized.

Spark Plasma Sintering Effect on Thermoelectric Properties of Nanostructured Bismuth Telluride Synthesized by High Energy Ball Milling.

Thermoelectric properties of high energy ball milled nano structured bismuth telluride (Bi2Te3) have been reported. By high energy ball milling, alloyed bulk crystalline ingots crush into nanopowder and followed by spark plasma sintering (SPS), we have demonstrate high figure of merit (ZT) in bismuth telluride pellet samples. In this work systematic study carried out on three pellet samples of Bi2Te3, synthesized by high ball milling for the time period of 4 hours, 8 hours and 12 hours and followed by SPS at the same processing parameters. A peak value of dimensionless figure of merit of about 1.22 at the temperature of 473 K has been achieved for 8 hours ball milled pellet sample. This enhancement in ZT value is mostly due to decrease in thermal conductivity. Results of this study demonstrate that ball milling and SPS has a major effect in controlling the density of grain boundaries of Bi2Te3 nano particles, while the pressure exerted on the powder samples during SPS introduce stress at the boundaries of the crystallites. These disordered crystallite boundary regions exert scattering of thermal energy carriers which reduced the thermal conductivity of the materials.