113 research outputs found
Harmonics mitigation on industrial loads using series and parallel resonant filters
Most industrial loads are inductive in nature and therefore absorb Volts Ampere Reactance (VARs) leading to lagging power factor. Some inductive loads also produce current and voltage signals with frequencies in integer multiples of the 50 or 60 Hz fundamental frequencies called harmonics. Harmonics in power system causes several problems ranging from overheating, premature equipment failure, false tripping of protective relays resulting in unnecessary down time in industrial production. This work compared the use of series and parallel resonant harmonic filters in suppressing harmonics using Simulink model of the power system of NICHEMTEX, a Textile industry in Nigeria as a case study. Mathematical analysis representing current harmonics distributions on industrials loads with and without capacitor banks were presented. From the analysis, series resonant filter mitigated the total harmonic distortion from 30.080% to 3.460%. The installation of capacitor bank along with the series resonant filter in the industrial facility, further reduced the total harmonic distortion to 0.001% and power factor compensated from 0.860 to 0.894.However, the use of parallel resonant filter mitigated the harmonic distortion to 8.107% and a reduction in the power factor from 0.860 to 0.840. With the parallel resonant filter connection with the capacitor bank, harmonic distortion was mitigated to 0.140%, and the power factor reduced to 0.553, the value which is very low. Hence, it is observed that for this sample case, the use of series resonant filter mitigated the harmonics distortion and maintained power factors within the acceptable IEEE standard values.Keywords: Industrial inductive loads, Harmonics, Harmonic distortions, Power factor correction, Series resonant filter, Parallel resonant filte
NTRK gene fusions as novel targets of cancer therapy across multiple tumour types
The tropomyosin receptor kinase (Trk) receptor family comprises 3 transmembrane proteins referred to as Trk A, B and C (TrkA, TrkB and TrkC) receptors that are encoded by the NTRK1, NTRK2 and NTRK3 genes, respectively. These receptor tyrosine kinases are expressed in human neuronal tissue and play an essential role in the physiology of development and function of the nervous system through activation by neurotrophins. Gene fusions involving NTRK genes lead to transcription of chimeric Trk proteins with constitutively activated or overexpressed kinase function conferring oncogenic potential. These genetic abnormalities have recently emerged as targets for cancer therapy, because novel compounds have been developed that are selective inhibitors of the constitutively active rearranged proteins. Developments in this field are being aided by next generation sequencing methods as tools for unbiased gene fusions discovery. In this article, we review the role of NTRK gene fusions across several tumour histologies, and the promises and challenges of targeting such genetic alterations for cancer therapy
Liquid biopsy for rectal cancer: a systematic review
Background: The management of locally advanced rectal cancer (RC) is an evolving clinical field where the multidisciplinary approach can reach its best, and liquid biopsy for obtaining tumor-derived component such as circulating tumor DNA (ctDNA) might provide complementary informations.
Methods: A systematic review of studies available in literature of liquid biopsy in non-metastatic RC has been performed according to PRISMA criteria to assess the role of ctDNA as a diagnostic, predictive and prognostic biomarker in this setting.
Results: Twenty-five publications have been retrieved, of which 8 full-text articles, 7 abstracts and 10 clinical trials. Results have been categorized into three groups: diagnostic, predictive and prognostic. Few but promising data are available about the use of liquid biopsy for early diagnosis of RC, with the main limitation of sensitivity due to low concentrations of ctDNA in this setting. In terms of prediction of response to chemoradiation, still inconclusive data are available about the utility of a pre-treatment liquid biopsy, whereas some studies report a positive correlation with a dynamic (pre/post-treatment) monitoring. The presence of minimal residual disease by ctDNA was consistently associated with worse prognosis across studies.
Conclusions: The use of liquid biopsy for monitoring response to chemoradiation and assess the risk of disease recurrence are the most advanced potential applications for liquid biopsy in RC, with implications also in the context of non-operative management strategies
High Circulating Methylated DNA Is a Negative Predictive and Prognostic Marker in Metastatic Colorectal Cancer Patients Treated With Regorafenib
Background: Regorafenib improves progression free survival (PFS) in a subset of metastatic colorectal cancer (mCRC) patients, although no biomarkers of efficacy are available. Circulating methylated DNA (cmDNA) assessed by a five-gene panel was previously associated with outcome in chemotherapy treated mCRC patients. We hypothesized that cmDNA could be used to identify cases most likely to benefit from regorafenib (i.e., patients with PFS longer than 4 months). Methods: Plasma samples from mCRC patients were collected prior to (baseline samples N = 60) and/or during regorafenib treatment (N = 62) for the assessment of cmDNA and total amount of cell free DNA (cfDNA). Results: In almost all patients, treatment with regorafenib increased the total cfDNA, but decreased cmDNA warranting the normalization of cmDNA to the total amount of circulating DNA (i.e., cmDNA/ml). We report that cmDNA/ml dynamics reflects clinical response with an increase in cmDNA/ml associated with higher risk of progression (HR for progression = 1.78 [95%CI: 1.01-3.13], p = 0.028). Taken individually, high baseline cmDNA/ml (above median) was associated with worst prognosis (HR for death = 3.471 [95%CI: 1.83-6.57], p < 0.0001) and also predicted shorter PFS (<16 weeks with PPV 86%). In addition, high cmDNA/ml values during regorafenib treatment predicted with higher accuracy shorter PFS (<16 weeks with a PPV of 96%), therefore associated with increased risk of progression (HR for progression = 2.985; [95%CI: 1.63-5.46; p < 0.0001). Conclusions: Our data highlight the predictive and prognostic value of cmDNA/ml in mCRC patients treated with regorafenib
Activity of osimeRTInib in non-small-cell lung Cancer with UNcommon epidermal growth factor receptor mutations: retrospective Observational multicenter study (ARTICUNO)
Background: Osimertinib represents the standard of care for the treatment of advanced non -small -cell lung cancer (NSCLC) harboring classical epidermal growth factor receptor ( EGFR ) mutations, constituting 80%-90% of all EGFR alterations. In the remaining cases, an assorted group of uncommon alterations of EGFR (uEGFR) can be detected, which confer variable sensitivity to previous generations of EGFR inhibitors, overall with lower therapeutic activity. Data on osimertinib in this setting are limited and strongly warranted. Patients and methods: The ARTICUNO study retrospectively evaluated data on osimertinib activity from patients with advanced NSCLC harboring uEGFR treated in 21 clinical centers between August 2017 and March 2023. Data analysis was carried out with a descriptive aim. Investigators collected response data according to RECIST version 1.1 criteria. The median duration of response, progression -free survival (mPFS), and overall survival were estimated by the Kaplan - Meier method. Results: Eighty-six patients harboring uEGFR and treated with osimertinib were identi fi ed. Patients with ' major ' uEGFR, that is, G719X, L861X, and S768I mutations ( n = 51), had an overall response rate (ORR) and mPFS of 50% and 9 months, respectively. Variable outcomes were registered in cases with rarer ' minor ' mutations ( n = 27), with ORR and mPFS of 31% and 4 months, respectively. Among seven patients with exon 20 insertions, ORR was 14%, while the best outcome was registered among patients with compound mutations including at least one classical EGFR mutation ( n = 13). Thirty patients presented brain metastases (BMs) and intracranial ORR and mPFS were 58% and 9 months, respectively. Ampli fi cation of EGFR or MET , TP53 mutations, and EGFR E709K emerged after osimertinib failure in a dataset of 18 patients with available rebiopsy. Conclusion: The ARTICUNO study con fi rms the activity of osimertinib in patients with uEGFR, especially in those with compound uncommon e common mutations, or major uEGFR, even in the presence of BMs. Alterations at the E709 residue of EGFR are associated with resistance to osimertinib
Phase II study of the dual EGFR/HER3 inhibitor duligotuzumab (MEHD7945A) vs. cetuximab in combination with FOLFIRI in RAS wild-type metastatic colorectal cancer
PURPOSE: Duligotuzumab is a dual-action antibody directed against EGFR and HER3. EXPERIMENTAL DESIGN: mCRC patients with KRAS ex2 wild-type received duligotuzumab or cetuximab and FOLFIRI until progression or intolerable toxicity. Mandatory tumor samples underwent mutation and biomarker analysis. Efficacy analysis was conducted in patients with RAS exon 2/3 wild-type tumors. RESULTS: Of 134 randomized patients, 98 were RAS ex2/3 wild-type. Duligotuzumab provided no PFS or OR benefit compared to cetuximab; though there was a trend for lower ORR in the duligotuzumab arm. No relationship was seen between PFS or ORR and ERBB3, NRG1, or AREG expression. There were fewer skin rash events for duligotuzumab but more diarrhea. Although the incidence of grade â„ 3 AEs was similar, the frequency of serious AEs was higher for duligotuzumab. CONCLUSIONS: Duligotuzumab plus FOLFIRI did not appear to improve the outcomes in patients with RAS exon 2/3 wild-type mCRC compared to cetuximab + FOLFIRI
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