557 research outputs found

    On the Systematic Constructions of Rotation Symmetric Bent Functions with Any Possible Algebraic Degrees

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    In the literature, few constructions of nn-variable rotation symmetric bent functions have been presented, which either have restriction on nn or have algebraic degree no more than 44. In this paper, for any even integer n=2m2n=2m\ge2, a first systemic construction of nn-variable rotation symmetric bent functions, with any possible algebraic degrees ranging from 22 to mm, is proposed

    Thermal analysis of FeCoCu pre-alloyed powders used for diamond tools

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    By simulating the pressureless sintering process, the thermal effects of FeCoCu pre-alloyed powders have been investigated. According to the notions of the Kissinger method, the activation energies in the expansion-shrinkage conversion stage are analyzed. Results show that with Fe content increasing, the specimens’ specific heat capacity values present the increasing trend. The 25 %Fe–15 %Co–60 %Cu specimens have negative enthalpy value at 10 and 20°C/min heating rate but positive values at 30 °С/min. For the specimens with lower Cu content, the enthalpies are always positive. It is established that both the specific heat capacity and enthalpy are larger when at higher heating rates. The activation energy of the 65 %Fe–15 %Co–20 %Cu specimens is 10 times higher than that of the 25 %Fe–15 %Co–60 %Cu specimens and the 45 %Fe–15 %Co–40 %Cu specimens.При моделюванні процесу спікання без тиску досліджено термічні ефекти в попередньо легованих порошках FeCoCu. З використанням методу Кіссінджера проаналізовано енергію активації на стадії розширення–усадка. Результати показують, що при збільшенні вмісту Fe значення питомої теплоємності демонструють тенденцію до зростання. Зразки 25 %Fe–15 %Co–60 %Cu мають негативні значення ентальпії при швидкості нагріву 10 ° і 20 °С/хв, але позитивні при 30 °С/хв. Для зразків з меншим вмістом Cu ентальпія завжди позитивна. Встановлено, що питома теплоємність і ентальпія більші при більш високіх швидкостях нагрівання. Енергія активації зразків 65 %Fe–15 %Co–20 %Cu у 10 разів вища, ніж зразків 25 %Fe–15 %Co–60 %Cu і 45 %Fe–15 %Co–40 %Cu.При моделировании процесса спекания без приложения давления исследованы термические эффекты в предварительно легированных порошках FeCoCu. С использованием метода Киссинджера проанализирована энергия активации на стадии расширение–усадка. Результаты показывают, что с увеличением содержания железа значения удельной теплоемкости образцов демонстрируют тенденцию к повышению. Образцы 25 %Fe–15 %Co–60 %Cu имеют отрицательные значения энтальпии при скорости нагрева 10 и 20 °С/мин, но положительные при 30 °С/мин. Для образцов с меньшим содержанием Cu энтальпия всегда положительна. Установлено, что удельная теплоемкость и энтальпия больше при более высоких скоростях нагрева. Энергия активации образцов 65 %Fe–15 %Co–20 %Cu в 10 раз выше, чем образцов 25 %Fe–15 %Co–60 %Cu и 45 %Fe–15 %Co–40 %Cu

    Seed Germination Indicates Adaptive Transgenerational Plasticity in a Submerged Macrophyte

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    Adaptive transgenerational plasticity is an important evolutionary strategy in plants. We investigated the resource allocation strategy in sexual reproduction and performed an in situ seed germination experiment of Potamogeton maackianus to reveal their responses to different water depths. Later, we discussed the biased adaptability to the maternal habitat in this species. We found a positive correlation between sexual and asexual reproduction in water depths from 1.0 m to 3.0 m, such a correlation failed to occur in 4.0 m water depth. These results indicate that the trade-off between sexual and asexual reproduction should only be expected in a stressful habitat, where resource acquisition is limited. For trade-off between quantity and quality of sexual units in different water depths, P. maackianus tends to produce more but lower quality sexual reproductive units in shallow water, and fewer but higher quality sexual units are found in deep water. The total germination percentage of seeds of P. maackianus was relatively poor, less than 46.65% in all of the treatments. The maximum germination percentage of seeds from 1.0 m, 2.0 m, 3.0 m, and 4.0 m water depths are 14.4%, 17.75%, 25.51%, and 46.65%, respectively. Seeds with higher germination percentage were from deeper water depths. The most interesting result was that the maximum final germination percentage occurred only when treatment water depth was the same as collection water depth. Our result showed that the variations in germination characters of the studied species appear to be based partly on the effects of maternal environmental factors. Our findings proved the adaptive transgenerational plasticity in P. maackianus, which will play an important role in evolutionary response to the selection of water depths

    Volumetric-modulated arc therapy as an alternative to intensity-modulated radiotherapy for primary tumors of advanced non–small-cell lung cancer: A multicenter retrospective analysis based on propensity score matching

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    Purpose: To investigate the effect of volumetric-modulated arc therapy (VMAT) versus intensity-modulated radiotherapy (IMRT) for advanced non–small-cell lung cancer (NSCLC). Methods: Cases in which the primary tumors were treated with IMRT or VMAT as initial intervention in stages III and IV NSCLC patients from September 2008 to March 2020 were retrospectively analyzed. Propensity Score Matching (PSM) was used to assess the efficacy and toxicity of the two radiotherapy techniques. Results: A total of 637 patients were included, out of which 483 cases were treated with IMRT, while 154 received VMAT. A total of 308 patients were selected after PSM. Patients who were having acute radiation esophagitis and pneumonia treated with VMAT had a lower percentage than those treated with IMRT (p < 0.05) before PSM. However, there was no significant difference in grades 3 - 4 toxicity (χ2 = 2.77, p = 0.096). There were also no significant differences in the primary endpoints between the two groups after PSM (p > 0.05), while for secondary endpoints, all lung V5, and V20, mean lung dose and heart V30, heart V40, mean heart dose in all patients and stage N2 patients in VMAT after PSM were significantly lower than those of IMRT (p < 0.05). Conclusion: Radiation therapy of A-NSCLC primary tumors using VMAT and IMRT seem to produce similar efficacy. The volume parameters of normal tissues and organs is significantly lower in VMAT, especially in patients with stage N2. Therefore, VMAT may be more beneficial for reducing radiation damage in normal tissues and organs

    Sustained high prevalence of viral hepatitis and sexually transmissible infections among female sex workers in China: a systematic review and meta-analysis.

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    BACKGROUND: The 1980's economic boom has been associated with a rapid expansion of China's sex industry over the past three decades. Consequently, the spread of sexually transmitted infections (STIs) and hepatitis infections among female sex workers (FSW) has become an important public health issue in China. This study identifies prevalence and risks of hepatitis and STIs in Chinese FSWs. METHOD: Four electronic databases were searched for Chinese and English language peer-reviewed studies conducted between 01/2000-12/2011 that reported prevalence of hepatitis and STIs (excluding HIV) among Chinese FSW. Following the PRISMA guidelines, meta-analysis was used to estimate pooled prevalence and 95% confidence intervals for each infection. RESULT: Three hundred and thirty nine articles (34 in English and 305 in Chinese) investigating 603,647 FSWs in 29 Chinese provinces were included in this review. Over the period 2000-2011, the seroprevalence of active hepatitis B and hepatitis C among FSW were 10.7% (7.3-15.5%) and 1.0% (0.7-1.3%), respectively. The most prevalent STI was human papillomavirus (HPV, 27.0% [10.1-55.1%]), followed by herpes simplex virus-2 (HSV-2, 15.8% [11.7-20.9%]), chlamydia (13.7% [12.1-15.4%]), gonorrhoea (6.1% [5.3-7.0%]), syphilis (5.2% [4.8-5.7%]), genital warts (3.3% [2.5-4.2%]) and Trichomonas vaginitis (2.1% [1.5-24.2%]). Disease burden of both hepatitis and STI among FSW were concentrated in South Central and Southwest China. In particular, chlamydia and syphilis demonstrated a significant declining trend during the studied period (P < 0.05). Compared with the general Chinese population, FSW had significantly higher prevalence of all STIs except Trichomonas vaginitis. Further, compared to the general FSW population, HIV-positive FSW had significantly higher prevalence of syphilis, chlamydia, HSV-2 and Trichomonas vaginitis. CONCLUSION: Prevalence of hepatitis and STIs remained high and mostly stable among Chinese FSW over the period of 2000-2011. Targeted STI and hepatitis surveillance and interventions should be strengthened among Chinese FSWs, especially those who are HIV-positive

    New advances in clinical application of neostigmine: no longer focusing solely on increasing skeletal muscle strength

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    Neostigmine is a clinical cholinesterase inhibitor, that is, commonly used to enhance the function of the cholinergic neuromuscular junction. Recent studies have shown that neostigmine regulates the immune-inflammatory response through the cholinergic anti-inflammatory pathway, affecting perioperative neurocognitive function. This article reviews the relevant research evidence over the past 20 years, intending to provide new perspectives and strategies for the clinical application of neostigmine

    A systematic review and meta-analysis of the prevalence, trends, and geographical distribution of HIV among Chinese female sex workers (2000-2011): implications for preventing sexually transmitted HIV.

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    OBJECTIVE: The aim of this meta-analysis was to investigate temporal and geographical trends in the HIV epidemic among female sex workers (FSWs) recruited from various venues in China. METHODS: Chinese and English peer-reviewed articles published between January 2000 and February 2013 were systematically searched. Standard meta-analysis methods were used to calculate the pooled HIV prevalence, in accordance with the PRISMA guidelines. RESULTS: The national HIV prevalence among FSWs declined from 0.74% (95% confidence interval (CI) 0.37-1.49%) in 2000-2002 to 0.40% (95% CI 0.31-0.53%) in 2009-2011. All Chinese regions demonstrated significant declines in HIV prevalence, apart from the East and South Central regions, in which the epidemics stabilized at low/moderate levels. Despite a significant decline from 1.92% (95% CI 0.86-4.24%) to 0.87% (95% CI 0.65-1.18%) during 2000-2011, Southwest China still bore the greatest HIV disease burden. Nationwide, FSWs recruited from detention centres had the highest HIV prevalence (0.92%, 95% CI 0.46-1.88%), followed by voluntary counselling and testing sites (0.80%, 95% CI 0.46-1.67%) and entertainment venues (0.61%, 95% CI 0.47-0.79%). The prevalences among FSWs in high-, middle-, and low-tier entertainment venues were 0.59% (95% CI 0.32-1.45%), 0.92% (95% CI 0.50-1.77%), and 1.10% (95% CI 0.71-2.16%), respectively. High- and middle-tier FSWs had a significantly lower risk of HIV infection than lower-tier FSWs (high/low: odds ratio (OR) 0.48, 95% CI 0.40-0.59; middle/low: OR 0.49, 95% CI 0.37-0.66). CONCLUSIONS: The HIV epidemic has shown a gradual declining or stabilizing trend among Chinese FSWs. Intervention efforts should be diverted to high-risk subgroups of FSWs, such as drug-using and low-tier FSWs

    Sustained high prevalence of viral hepatitis and sexually transmissible infections among female sex workers in China: a systematic review and meta-analysis

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    Abstract Background The 1980’s economic boom has been associated with a rapid expansion of China’s sex industry over the past three decades. Consequently, the spread of sexually transmitted infections (STIs) and hepatitis infections among female sex workers (FSW) has become an important public health issue in China. This study identifies prevalence and risks of hepatitis and STIs in Chinese FSWs. Method Four electronic databases were searched for Chinese and English language peer-reviewed studies conducted between 01/2000-12/2011 that reported prevalence of hepatitis and STIs (excluding HIV) among Chinese FSW. Following the PRISMA guidelines, meta-analysis was used to estimate pooled prevalence and 95 % confidence intervals for each infection. Result Three hundred and thirty nine articles (34 in English and 305 in Chinese) investigating 603,647 FSWs in 29 Chinese provinces were included in this review. Over the period 2000–2011, the seroprevalence of active hepatitis B and hepatitis C among FSW were 10.7 % (7.3–15.5 %) and 1.0 % (0.7–1.3 %), respectively. The most prevalent STI was human papillomavirus (HPV, 27.0 % [10.1–55.1 %]), followed by herpes simplex virus-2 (HSV-2, 15.8 % [11.7–20.9 %]), chlamydia (13.7 % [12.1–15.4 %]), gonorrhoea (6.1 % [5.3–7.0 %]), syphilis (5.2 % [4.8–5.7 %]), genital warts (3.3 % [2.5–4.2 %]) and Trichomonas vaginitis (2.1 % [1.5–24.2 %]). Disease burden of both hepatitis and STI among FSW were concentrated in South Central and Southwest China. In particular, chlamydia and syphilis demonstrated a significant declining trend during the studied period (P < 0.05). Compared with the general Chinese population, FSW had significantly higher prevalence of all STIs except Trichomonas vaginitis. Further, compared to the general FSW population, HIV-positive FSW had significantly higher prevalence of syphilis, chlamydia, HSV-2 and Trichomonas vaginitis. Conclusion Prevalence of hepatitis and STIs remained high and mostly stable among Chinese FSW over the period of 2000–2011. Targeted STI and hepatitis surveillance and interventions should be strengthened among Chinese FSWs, especially those who are HIV-positive
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