273 research outputs found

    Microstructured reactor as a pre-turbo catalytic converter

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    The idea of a structured catalytic converter placed immediately after engine exhaust valves, thus operating on high gas temperature and velocity, is explored. The assumption is that major part of the reactor operates in the entry region where Nusselt and Sherwood numbers are highly enhanced. In this work, flow resistances as well as heat and mass transfer coefficients were studied for gas velocities exceeding 50 m/s. Consequently, the transition range (between laminar and turbulent flows) was reached. The comparison with classic monolith has shown significant improvement in heat or mass transfer paid by slight increase in flow resistance

    Hand anthropometry in patients with carpal tunnel syndrome: a case-control study with a matched control group of healthy volunteers

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    Background: The aim of this study was to perform anthropometrical measure- ments of patients’ hands with carpal tunnel syndrome (CTS) in order to evaluate if there is a correlation between CTS occurrence and hand features regarding sexual dimorphism, age and physical activity.  Materials and methods: Study sample consisted of 48 patients (33 females) and control group included 80 healthy volunteers (58 females) with no history of CTS. The following measurements were performed: the wrist circumference, length of the hand, the hand’s width, width of the wrist, thickness of the wrist, height of the hypothenar and thenar, length of the arm and forearm, circumference of the proximal phalanges and width of the digits; as well as several indexes were calculated i.e.: body mass index (BMI), shape index, digit index, wrist index, hand length/height ratio (HLH-ratio) and hand length/upper limb length ratio (HLULL-ratio).  Results: Correlation coincidences were analysed between circumferences within the hand, palm and body weight. All parameters except fingers were correlated with body weight in either gender in both groups (p < 0.05; r = 0.40–0.80); Furthermore, width of the hand was correlated with body height (p < 0.001; r = 0.56–0.71). Mean values of wrist index for CTS patients were: males: 0.8, females: 0.74 (significantly higher than in healthy individuals and indicating square shape); shape index: males 76.5, females 75.8; digit index: males 55.7, females 56.5. The calculated HLH-ratio in CTS group was: males 10.6, females 10.9; HLULL-ratio: males 23.6, females 24.9 and they did not differ significantly from healthy volunteers. Almost 90.0% of females with diagnosed CTS have BMI > 25.0 kg/m2.  Conclusions: There are significant differences in morphometrical features of the upper limbs between CTS patients and healthy individuals. Hands of patients with CTS are more massive and with ‘plumb’ fingers and square shape of the wrist. Furthermore, higher BMI values were confirmed to be predisposing factors in CTS occurrence.

    The characteristics of breast cancer patients with metachronous primary malignancies

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        Introduction. The risk of developing subsequent primary cancers varies from 1% to 18% and it depends on the type of first cancer and treatment methods applied. Considering the time of occurrence, multiple primary cancers generally fall into two categories: synchronous and metachronous. In breast cancer patients, 10.5% developed multiple primary cancers, from which 23.8% had synchronous, 79% had metachronous and the remaining 2.8% had both synchronous and metachronous malignancies. In patients with breast cancer, elevated risk is observed especially in the development of contralateral breast cancer, endometrial cancer, esophageal cancer, ovarian cancer and thyroid cancer. Aim. This paper presented the characteristics of breast cancer patients with metachronous primary malignancies in relation to the type of metachronous primaries (breast versus non-breast) and to analyse the impact of the type of metachronous cancers on survival rate. Material and methods. Among patients treated for breast cancer between 1963 and 2010, 354 patients (2.1%) developed metachronous primary malignancies and these made up 13.8% of all patients with multiple primary cancers. The mean age at diagnosis of the first breast cancer was 53 ± 11.5 years; positive family cancer history was noted in 127 patients (35.9%). Metachronous malignancies are defined as primaries following the diagnosis of breast cancer in a time interval greater than or equal to than 6 months. In our group, the mean time interval between the diagnosis of breast cancer and the appearance of metachronous malignancies was 100.9 ± 74.9 months (range: 6–543 months, median: 83 months). For comparison of the two groups (patients with second breast vs non-breast cancer) we used the Pearson’s Chi-square test for independence (for categorized variables) and variance analysis with Student’s t-test (for continuous variables). The survival rate was evaluated with the Kaplan-Meier method, and the log rank test was applied to assess the influ­ence of some factors on the evaluated results. The significance level at α = 0.05 was adopted for all statistical analyses. Results. The probability of occurrence of new cancer averaged from 38.1% to 67.8% for 5 and 10 years after diagnosis of first breast cancer, respectively. In our group, 380 cases of metachronous carcinomas were noted in 354 analysed patients. The most frequent metachronous malignancy was breast cancer (194 cases — 54.8%), which occurred as second (192 cases) or third (2 cases) cancer. Patients with contralateral breast cancer in comparison to other types of metachronous malignancies were significantly (p < 0.05): younger (under 50 years: 56.2% vs 34.4%), premenopausal (69.6% vs 48.8%), had a lobular type of first breast cancer (6.7% vs 1.3%), and rarely received tamoxifen (25.3% vs 48.2%). The type of me­tachronous cancers significantly influenced survival rate: 10-year overall survival rates were 80.1% vs 67.8%, (p = 0.0271). Conclusions. The risk of occurrence of second malignancies in breast cancer survivors makes early detection of metachronous malignancies obligatory because it is an important factor which influences the quality of life in breast cancer survivors

    The characteristics of breast cancer patients with metachronous primary malignancies

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      Introduction. The risk of developing subsequent primary cancers varies from 1% to 18% and it depends on the type of first cancer and treatment methods applied. Considering the time of occurrence, multiple primary cancers gene­rally fall into two categories: synchronous and metachronous. In breast cancer patients, 10.5% developed multiple primary cancers, from which 23.8% had synchronous, 79% had metachronous and the remaining 2.8% had both synchronous and metachronous malignancies. In patients with breast cancer, elevated risk is observed especially in the development of contralateral breast cancer, endometrial, esophageal cancer, ovarian cancer and thyroid cancer. Aim. This paper presented the characteristics of breast cancer patients with metachronous primary malignancies in relation to the type of metachronous primaries (breast versus non-breast) and to analyse the impact of the type of metachronous cancers on survival rate. Material and methods. Among patients treated for breast cancer between 1963 and 2010, 354 patients (2.1%) deve­loped metachronous primary malignancies and these made up 13.8% of all patients with multiple primary cancers. The mean age at diagnosis of the first breast cancer was 53 ± 11.5 years; positive family cancer history was noted in 127 patients (35.9%). Metachronous malignancies are defined as primaries following the diagnosis of breast cancer in a time interval greater than or equal to than 6 months. In our group, the mean time interval between the diagnosis of breast cancer and the appearance of metachronous malignancies was 100.9 ± 74.9 months (range: 6–543 months, median: 83 months). For comparison of the two groups (patients with second breast vs non-breast cancer) we used the Pearson’s Chi-square test for independence (for categorized variables) and variance analysis with Student’s t-test (for continuous variables). The survival rate was evaluated with the Kaplan-Meier method, and the log rank test was applied to assess the influ­ence of some factors on the evaluated results. The significance level at α = 0.05 was adopted for all statistical analyses. Results. The probability of occurrence of new cancer averaged from 38.1% to 67.8% for 5 and 10 years after diagnosis of first breast cancer, respectively. In our group, 380 cases of metachronous carcinomas were noted in 354 analysed patients. The most frequent metachronous malignancy was breast cancer (194 cases — 54.8%), which occurred as second (192 cases) or third (2 cases) cancer. Patients with contralateral breast cancer in comparison to other types of metachronous malignancies were significantly (p < 0.05): younger (under 50 years: 56.2% vs 34.4%), premenopausal (69.6% vs 48.8%), had a lobular type of first breast cancer (6.7% vs 1.3%), and rarely received tamoxifen (25.3% vs 48.2%). The type of metachronous cancers significantly influenced survival rate: 10-year overall survival rates were 80.1% vs 67.8%, (p = 0.0271). Conclusions. The risk of occurrence of second malignancies in breast cancer survivors makes early detection of metachronous malignancies obligatory because it is an important factor which influences the quality of life in breast cancer survivors

    Fibre-optic delivery of time and frequency to VLBI station

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    The quality of Very Long Baseline Interferometry (VLBI) radio observations predominantly relies on precise and ultra-stable time and frequency (T&F) standards, usually hydrogen masers (HM), maintained locally at each VLBI station. Here, we present an operational solution in which the VLBI observations are routinely carried out without use of a local HM, but using remote synchronization via a stabilized, long-distance fibre-optic link. The T&F reference signals, traceable to international atomic timescale (TAI), are delivered to the VLBI station from a dedicated timekeeping laboratory. Moreover, we describe a proof-of-concept experiment where the VLBI station is synchronized to a remote strontium optical lattice clock during the observation.Comment: 8 pages, 8 figures, matches the version published in A&A, section Astronomical instrumentatio

    The characteristics of bilateral breast cancer patients

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    Introduction. Bilateral breast cancer (BBC) consists of 2–12% all cases of breast carcinoma. In relation to time between the first and second cancer diagnosis, the synchronous (s-BBC) or metachronous (m-BBC) bilateral breast cancer is defined. Material and methods. The clinicopathologic characteristics of 303 patients treated between 1963 and 2014 for bilateral breast cancer was presented. Synchronous BBC was diagnosed in 70 patients (23.1%) and remaining 233 patients (76.9%) developed metachronous BBC. Patients with m-BBC in comparison to s-BBC were younger (mean age: 51.4 vs 60.6 years), the positive family cancer history was rare (36.7% vs 48.5%), and more frequently these patients were before menopause (65.7% vs 44.3%). While the lobular type of breast cancer which consisted of 6.6% cases in first breast and 8.9% cases of second carcinomas, more frequently was presented in s-BBC (8.6%) in comparison to m-BBC (6%). Results. The mean time of follow up was 174 months. The 5- and 10-year overall survival rates were 89.3% and 76.1%, respectively. The presence of s-BBC connected with worse prognosis; the 5- and 10-year overall survival were 93.1% and 82% for m-BBC and 76.4% and 52.1% for s-BBC (p = 0.00244, log-rank test).Introduction. Bilateral breast cancer (BBC) consists of 2–12% all cases of breast carcinoma. In relation to time between the first and second cancer diagnosis, the synchronous (s-BBC) or metachronous (m-BBC) bilateral breast cancer is defined. Material and methods. The clinicopathologic characteristics of 303 patients treated between 1963 and 2014 for bilateral breast cancer was presented. Synchronous BBC was diagnosed in 70 patients (23.1%) and remaining 233 patients (76.9%) developed metachronous BBC. Patients with m-BBC in comparison to s-BBC were younger (mean age: 51.4 vs 60.6 years), the positive family cancer history was rare (36.7% vs 48.5%), and more frequently these patients were before menopause (65.7% vs 44.3%). While the lobular type of breast cancer which consisted of 6.6% cases in first breast and 8.9% cases of second carcinomas, more frequently was presented in s-BBC (8.6%) in comparison to m-BBC (6%). Results. The mean time of follow up was 174 months. The 5- and 10-year overall survival rates were 89.3% and 76.1%, respectively. The presence of s-BBC connected with worse prognosis; the 5- and 10-year overall survival were 93.1% and 82% for m-BBC and 76.4% and 52.1% for s-BBC (p = 0.00244, log-rank test)

    Synchronous malignancies in patients with breast cancer

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    Introduction. The continuously improving cancer detection at an early stage and improving survival rates have been observed and, therefore, patients are predisposed to detection of multiple primaries. It has been reported that the incidence of multiple primaries in breast cancer patients ranges from of 4% to 17%. Materials and methods. A group of 112 breast cancer patients with synchronous malignancies was presented. They constituted 0.09% of patients (118,952 cases) who were treated for breast cancer at the same time period, and made up 3.5% of all patients (3,176 cases) with multiple primary cancers, and 21.7% of all patients (517 cases) with breast cancer who developed multiple primaries. Results. The most frequent type of synchronous primary malignancy was breast cancer (63.4%) and 90.1% of them were diagnosed at the same time or within one month following the first breast cancer diagnosis. Among cases of non-breast synchronous primaries, female genital organ malignancies were predominant (36.6%). Synchronous breast cancer was diagnosed significantly earlier than non-breast cancers (mean time was 0.4 and 1 month, respectively, p = 0.0123). Better results in the group with synchronous contralateral breast cancer in comparison to synchronous breast and non-breast cancer were observed (5-year overall survival rates were 90.9% and 66.3%, respectively, and 5-year disease-free survival rate — 62.5% and 51.3%, respectively)

    Synchronous malignancies in patients with breast cancer

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    Introduction. The continuously improving cancer detection at an early stage and improving survival rates have been observed and, therefore, patients are predisposed to detection of multiple primaries. It has been reported that the incidence of multiple primaries in breast cancer patients ranges from of 4% to 17%. Materials and methods. A group of 112 breast cancer patients with synchronous malignancies was presented. They constituted 0.09% of patients (118,952 cases) who were treated for breast cancer at the same time period, and made up 3.5% of all patients (3,176 cases) with multiple primary cancers, and 21.7% of all patients (517 cases) with breast cancer who developed multiple primaries. Results. The most frequent type of synchronous primary malignancy was breast cancer (63.4%) and 90.1% of them were diagnosed at the same time or within one month following the first breast cancer diagnosis. Among cases of non-breast synchronous primaries, female genital organ malignancies were predominant (36.6%). Synchronous breast cancer was diagnosed significantly earlier than non-breast cancers (mean time was 0.4 and 1 month, respectively, p = 0.0123). Better results in the group with synchronous contralateral breast cancer in comparison to synchronous breast and non-breast cancer were observed (5-year overall survival rates were 90.9% and 66.3%, respectively, and 5-year disease-free survival rate — 62.5% and 51.3%, respectively)
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