17 research outputs found

    Generation and characterization of isolated attosecond pulses at 100  kHz repetition rate

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    The generation of coherent light pulses in the extreme ultraviolet (XUV) spectral region with attosecond pulse durations constitutes the foundation of the field of attosecond science. Twenty years after the first demonstration of isolated attosecond pulses, they continue to be a unique tool enabling the observation and control of electron dynamics in atoms, molecules, and solids. It has long been identified that an increase in the repetition rate of attosecond light sources is necessary for many applications in atomic and molecular physics, surface science, and imaging. Although high harmonic generation (HHG) at repetition rates exceeding 100 kHz, showing a continuum in the cutoff region of the XUV spectrum, was already demonstrated in 2013, the number of photons per pulse was insufficient to perform pulse characterization via attosecond streaking, let alone to perform a pump-probe experiment. Here we report on the generation and full characterization of XUV attosecond pulses via HHG driven by near-single-cycle pulses at a repetition rate of 100 kHz. The high number of 106 XUV photons per pulse on target enables attosecond electron streaking experiments through which the XUV pulses are determined to consist of a dominant single attosecond pulse. These results open the door for attosecond pump-probe spectroscopy studies at a repetition rate 1 or 2 orders of magnitude above current implementations

    Amplification of Cycline D1, C-Myc and Egfr Oncogenes in Tumour Samples of Breast Cancer Patients

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    Background: Breast cancer is the most common form of cancer in women. It arises from multiple genetic changes in oncogenes and tumor suppressor genes. Among so far studied oncogenes relatively few, including epdermal growth factor receptor (EGFR), cyclinD1 (CCND1) and c-myc, have been found to play an important role in progression of this type of human malignancy. The aim of this study was to examine the prognostic potential of CCND1, c-myc and EGFR amplification and their possible cooperation in breast carcinogenesis. Methods: Copy number analyses of CCND1 and c-myc genes were done by TaqMan based quantitative real time PCR. Amplification status of EGFR was determined by differential PCR. Results: Amplification of CCND1, c-myc and EGFR oncogene has been found in 20.4%, 26.5% and 26.5% of breast cancer cases, respectively. Analysis showed that amplification of CCND1 oncogene was significantly associated with the stage II of disease while amplification of EGFR gene was significantly associated with overexpression of HER-2/neu. Tumour stage and expression of HER-2/neu appeared to be significant predictors of patients outcome. Stage I patients lived significantly longer then stage III patients (p=0.04) while patients with HER-2/neu overexpression had worse prognoses and lived significantly shorter (p=0.001). Finally, survival of patients who underwent hormone therapy only was significantly longer (p=0.001) then survival of the rest of patients. Conclusions: Amplification of CCND1 or EGFR oncogene is associated with the progression of breast cancer and bad prognosis. No co-ordination in amplification of CCND1, c-myc and EGFR oncogenes were established in this cohort of breast cancer patients

    The impact of PTEN tumor suppressor gene on acquiring resistance to tamoxifen treatment in breast cancer patients

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    Tamoxifen is a standard therapeutical treatment in patients with estrogen receptor positive breast carcinoma. However, less than 50% of estrogen receptor positive breast cancers do not respond to tamoxifen treatment whereas 40% of tumors that initially respond to treatment develop resistance over time. The underlying mechanisms for tamoxifen resistance are probably multifactorial but remain largely unknown. The primary aim of this study was to investigate the impact of PTEN tumor suppressor gene on acquiring resistance to tamoxifen by analyzing loss of heterozygosity (LOH) and immunohystochemical expression of PTEN in 49 primary breast carcinomas of patients treated with tamoxifen as the only adjuvant therapy. The effect of PTEN inactivation on breast cancer progression and disease outcome was also analyzed. Reduced or completely lost PTEN expression was observed in 55.1% of samples, while 63.3% of samples displayed LOH of PTEN gene. Inactivation of PTEN immunoexpression significantly correlated with the PTEN loss of heterozygosity, suggesting LOH as the most important genetic mechanism for the reduction or complete loss of PTEN expression in primary breast carcinoma. Most importantly, LOH of PTEN and consequential reduction of its immunoexpression showed significant correlation with the recurrence of the disease. Besides, our study revealed that LOH of PTEN tumor suppressor was significantly associated with shorter disease free survival, breast cancer specific survival and overall survival. In summary, our results imply that LOH of PTEN could be used as a good prognostic characteristic for the outcome of breast cancer patients treated with tamoxifen

    Fuel consumption comparison of two forwarders in lowland forests of pedunculate oak

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    Fuel consumption of forest machinery and vehicles depends mainly on terrain conditions, working methods, drivers’ skills, engine load under working conditions, engine speed, type and technical characteristics of the machine. In timber harvesting operations, fuel consumption is significant for both, economic (costs), and environmental issues (80-95% of exhaust emissions and soot particles are associated with fuel consumption). The objective of this study was to compare fuel consumption in two different forwarders and to analyse two different measuring devices for fuel consumption. Fuel consumption was measured on a 6-wheeled Valmet 840.2 forwarder and an 8-wheeled Valmet 860.4 during roundwood and energy wood extraction in winter period. A differential fuel flow meter and a fuel measuring probe were used for measuring fuel consumption as well as a Fleet Management System (FMS) for transmitting measured data. Fuel consumption was expressed in six different ways depending on the stage of the working cycle, time, travelled distance, load volume and load mass. Finally, both the advantages and disadvantages of the used fuel measuring devices were gained. The results indicated higher fuel consumption of the smaller Valmet 840.2 forwarder due to lower soil bearing capacity and longer extraction distances. For both forwarders, higher fuel consumption (expressed in l t-1 km-1) was observed while extracting energy wood due to its lower overall mass

    COVID-19 in patients with cancer: first report of the ESMO international, registry-based, cohort study (ESMO-CoCARE)

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    Background: ESMO COVID-19 and CAncer REgistry (ESMO-CoCARE) is an international collaborative registry-based, cohort study gathering real-world data from Europe, Asia/Oceania and Africa on the natural history, management and outcomes of patients with cancer infected with severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2). Patients and methods: ESMO-CoCARE captures information on patients with solid/haematological malignancies, diagnosed with coronavirus disease 2019 (COVID-19). Data collected since June 2020 include demographics, comorbidities, laboratory measurements, cancer characteristics, COVID-19 clinical features, management and outcome. Parameters influencing COVID-19 severity/recovery were investigated as well as factors associated with overall survival (OS) upon SARS-CoV-2 infection. Results: This analysis includes 1626 patients from 20 countries (87% from 24 European, 7% from 5 North African, 6% from 8 Asian/Oceanian centres), with COVID-19 diagnosis from January 2020 to May 2021. Median age was 64 years, with 52% of female, 57% of cancer stage III/IV and 65% receiving active cancer treatment. Nearly 64% patients required hospitalization due to COVID-19 diagnosis, with 11% receiving intensive care. In multivariable analysis, male sex, older age, Eastern Cooperative Oncology Group (ECOG) performance status ≥2, body mass index (BMI) <25 kg/m2, presence of comorbidities, symptomatic disease, as well as haematological malignancies, active/progressive cancer, neutrophil-to-lymphocyte ratio (NLR) ≥6 and OnCovid Inflammatory Score ≤40 were associated with COVID-19 severity (i.e. severe/moderate disease requiring hospitalization). About 98% of patients with mild COVID-19 recovered, as opposed to 71% with severe/moderate disease. Advanced cancer stage was an additional adverse prognostic factor for recovery. At data cut-off, and with median follow-up of 3 months, the COVID-19-related death rate was 24.5% (297/1212), with 380 deaths recorded in total. Almost all factors associated with COVID-19 severity, except for BMI and NLR, were also predictive of inferior OS, along with smoking and non-Asian ethnicity. Conclusions: Selected patient and cancer characteristics related to sex, ethnicity, poor fitness, comorbidities, inflammation and active malignancy predict for severe/moderate disease and adverse outcomes from COVID-19 in patients with cancer. © 2022 The Author

    COVID-19 in patients with cancer: first report of the ESMO international, registry-based, cohort study (ESMO-CoCARE).

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    BACKGROUND: ESMO COVID-19 and CAncer REgistry (ESMO-CoCARE) is an international collaborative registry-based, cohort study gathering real-world data from Europe, Asia/Oceania and Africa on the natural history, management and outcomes of patients with cancer infected with severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2). PATIENTS AND METHODS: ESMO-CoCARE captures information on patients with solid/haematological malignancies, diagnosed with coronavirus disease 2019 (COVID-19). Data collected since June 2020 include demographics, comorbidities, laboratory measurements, cancer characteristics, COVID-19 clinical features, management and outcome. Parameters influencing COVID-19 severity/recovery were investigated as well as factors associated with overall survival (OS) upon SARS-CoV-2 infection. RESULTS: This analysis includes 1626 patients from 20 countries (87% from 24 European, 7% from 5 North African, 6% from 8 Asian/Oceanian centres), with COVID-19 diagnosis from January 2020 to May 2021. Median age was 64 years, with 52% of female, 57% of cancer stage III/IV and 65% receiving active cancer treatment. Nearly 64% patients required hospitalization due to COVID-19 diagnosis, with 11% receiving intensive care. In multivariable analysis, male sex, older age, Eastern Cooperative Oncology Group (ECOG) performance status ≥2, body mass index (BMI) <25 kg/m2, presence of comorbidities, symptomatic disease, as well as haematological malignancies, active/progressive cancer, neutrophil-to-lymphocyte ratio (NLR) ≥6 and OnCovid Inflammatory Score ≤40 were associated with COVID-19 severity (i.e. severe/moderate disease requiring hospitalization). About 98% of patients with mild COVID-19 recovered, as opposed to 71% with severe/moderate disease. Advanced cancer stage was an additional adverse prognostic factor for recovery. At data cut-off, and with median follow-up of 3 months, the COVID-19-related death rate was 24.5% (297/1212), with 380 deaths recorded in total. Almost all factors associated with COVID-19 severity, except for BMI and NLR, were also predictive of inferior OS, along with smoking and non-Asian ethnicity. CONCLUSIONS: Selected patient and cancer characteristics related to sex, ethnicity, poor fitness, comorbidities, inflammation and active malignancy predict for severe/moderate disease and adverse outcomes from COVID-19 in patients with cancer
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