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The present study was undertaken to investigate the antiparasitic activity of extracellular products of Streptomyces albus. Bioactivity-guided isolation of chloroform extracts affording a compound showing potent activity. The structure of the compound was elucidated as salinomycin (SAL) by EI-MS, 1H NMR and 13C NMR. In vitro test showed that SAL has potent anti-parasitic efficacy against theronts of Ichthyophthirius multifiliis with 10 min, 1, 2, 3 and 4 h (effective concentration) EC50 (95% confidence intervals) of 2.12 (2.22–2.02), 1.93 (1.98–1.88), 1.42 (1.47–1.37), 1.35 (1.41–1.31) and 1.11 (1.21–1.01) mg L−1. In vitro antiparasitic assays revealed that SAL could be 100% effective against I. multifiliis encysted tomonts at a concentration of 8.0 mg L−1. In vivo test demonstrated that the number of I. multifiliis trophonts on Erythroculter ilishaeformis treated with SAL was markedly lower than that of control group at 10 days after exposed to theronts (P < 0.05). In the control group, 80% mortality was observed owing to heavy I. multifiliis infection at 10 days. On the other hand, only 30.0% mortality was recorded in the group treated with 8.0 mg L−1 SAL. The median lethal dose (LD50) of SAL for E. ilishaeformis was 32.9 mg L−1.
In this study, AlGaN/GaN MIS-HEMTs with a p-GaN cap layer and ALD deposited Al2O3 gate insulator were fabricated. Devices with two different thicknesses of p-GaN cap layers were investigated and compared. AlGaN/GaN MIS-HEMT with an 8-nm p-GaN cap showed a better DC characteristics than device with a 5-nm p-GaN cap. The drain current of 662.9 mA/mm, a high on/off current ratio of 2.67×109 and a breakdown voltage of 672 V were measured in device with an 8-nm p-GaN cap. In addition, lateral leakage current was investigated by using adjacent MIS gate structures with a separation of 3 μm to investigate the leakage current.
Low-temperature stress is an important limiting factor to tobacco growth in early spring of south China. In this study, a low-temperature-resistant agent (LTRA) was employed to examine its ameliorating effect on the inhibition of tobacco growth triggered by low-temperature stress. Results indicated that low-temperature stress of 12 °C for 6 days reduced root number and biomass of tobacco seedling by 27.4% and 24.1%, while treatment with LTRA could recover the inhibitory effect of low-temperature stress on tobacco growth significantly. The content of ascorbic acid and the activities of superoxide dismutase and catalase at low-temperature stress were 65.2%, 53.5% and 32.1% of those at normal temperature condition (26 °C), while the corresponding values with LTRA treatment were 89.2%, 88.9% and 74.2%, suggesting that LTRA treatment could enhance the activity of antioxidant enzyme and the synthesis of antioxidant compounds. Low-temperature stress increased the membrane permeability by 84.8%, while LTRA treatment recovered it by 77.4%. Furthermore, LTRA treatment contributed to increase chlorophyll synthesis and maintain the integrity of tobacco leaf structure. Effective component analysis indicated that the complex of ammonium calcium nitrate and glycine betaine was the main effective component of LTRA in maintaining membrane integrity. Its effective concentration was 1.0 g L−1. The above results suggested that LTRA could enhance the synthesis of chlorophyll, activate the activity of antioxidant enzyme, maintain the integrity of cell membrane, and thus elevate the tolerance of tobacco seedlings to low-temperature stress.
The aim of this study was to evaluate the therapeutic effects of osteopontin neutralization treatment on schistosome-induced liver injury in BALB/C mice. We randomly divided 100 BALB/C mice into groups A, B, C, D and group E. Mice in all groups except group A were abdominally infected with schistosomal cercariae to induce a schistosomal hepatopathological model. Mice in group C, D and group E were respectively administered with praziquantel, praziquantel plus colchicine and praziquantel plus neutralizing osteopontin antibody. We extracted mouse liver tissues at 3 and 9 weeks after the ‘stool-eggs-positive’ day, observed liver histopathological changes by haematoxylin-eosin and Masson trichrome staining and detected the expression of osteopontin, alpha-smooth muscle actin (α-SMA) and transforming growth factor-beta (TGF-β1) by immunohistochemistry, RT-PCR and Western blot. We found that praziquantel plus neutralizing osteopontin antibody treatment significantly decreased the granuloma dimension, the percentage of collagen and the expression of osteopontin, α-SMA and TGF-β1 compared to praziquantel plus colchicine treatment in both the acute and chronic stage of schistosomal liver damage (P<0·05). So we believe that the combined regimen of osteopontin immunoneutralization and anti-helminthic treatment can reduce the granulomatous response and liver fibrosis during the schistosomal hepatopathologic course.
Background. This is the first study to examine variation across cohorts in lifetime risk of DSM-IV mental disorders in metropolitan China.
Method. Face-to-face household interviews of 2633 adults in Beijing and 2568 adults in Shanghai were conducted from November 2001 to February 2002 using a multi-stage household probability sampling method. The Chinese World Mental Health (WMH) Survey Initiative version of the WHO Composite International Diagnostic Interview (WMH-CIDI) was used for assessment.
Results. Lifetime prevalence of any disorder was 13·2%. Alcohol abuse (4·7%), major depressive disorder (3·5%), and specific phobia (2·6%) were the most common disorders. The median age of onset was later for mood (43 years) than anxiety (17 years) and substance use (25 years) disorders. Compared to observed lifetime prevalence, the projected lifetime risk as of age 75 years increased by 106% for major depressive disorder (7·2%), and was uniformly higher for all disorders. Relative odds of any lifetime disorder were 4·7 in the most recent cohorts (ages 18–34) compared to the eldest cohorts (ages [ges ]65).
Conclusions. The findings of this cross-sectional study tally with the view that rapid socioeconomic changes may bring about increasing incidence of mental disorders in China. However, prospective longitudinal studies are needed to confirm if the increase is real. Because of the huge size of the Chinese population, any increase in projected lifetime risk of mental disorders represents an enormous increase in the number of affected individuals.
Background. Psychiatric epidemiological surveys in China have repeatedly found much lower prevalence estimates than in most other parts of the world.
Method. Face-to-face household interviews of 5201 subjects (2633 in Beijing and 2568 in Shanghai respectively) were conducted from November 2001 to February 2002 using a multistage household probability sampling method. A Chinese version of the World Health Organization Composite International Diagnostic Interview (CIDI) was used for assessment.
Results. Twelve-month prevalence of any DSM-IV mental disorder in metropolitan China is estimated to be 7·0%, with major depressive disorder (2·0%), specific phobia (1·9%), and intermittent explosive disorder (1·7%) the most common disorders. Of these, 13·9% are classified as serious, 32·6% moderate, and 53·5% mild. Only 3·4% of respondents with any disorder sought treatment within the previous 12 months.
Conclusions. Although the general pattern of disorders, risk factors, and unmet need for treatment are similar to those in other countries, a low prevalence of mental disorders is found in metropolitan China. Resolving methodological problems that cause downward bias in estimates, such as stigma-related under-reporting and diagnostic incongruity with a somatopsychic mode of symptom presentation may lead to more accurate and probably higher prevalence estimates in future epidemiological studies. As a low prevalence still translates into an enormous number of people in China, measures are urgently needed to address the huge unmet need for treatment of mental disorders.
Pure vapor-grown carbon nanofibers (VGCNF's) with controllable diameters of 10–200 nm were prepared by an improved floating catalyst method. Through transmission electron microscopy (TEM) observation, it was found that VGCNF's have a duplex structure, a hollow and high-crystallinity graphite filament called primary carbon fiber surrounded by a pyrocarbon layer with low graphite crystallinity. It was observed using high-resolution TEM that VGCNF's have excellent graphitic crystallinity with graphite layers stacked neatly parallel to fiber axis. Moreover, x-ray diffraction results showed that the graphitic crystallinity of carbon fibers became higher with decreasing diameter of carbon fibers.
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