AIM: To investigate the effect of moxibustion on intestinal flora and release of interleukin-12 (IL-12) and tumor necrosis factor-α (TNF-α) from the colon in rat with ulcerative colitis (UC). METHODS: A rat model of...AIM: To investigate the effect of moxibustion on intestinal flora and release of interleukin-12 (IL-12) and tumor necrosis factor-α (TNF-α) from the colon in rat with ulcerative colitis (UC). METHODS: A rat model of UC was established by local stimulation of the intestine with supernatant from colonic contents harvested from human UC patients. A total of 40 male Sprague-Dawley rats were randomly divided into the following groups: normal (sham), model (UC), herb-partition moxibustion (HPM-treated), and positive control sulfasalazine (SA-treated). Rats treated with HPM received HPM at acupuncture points ST25 and RN6, once a day for 15 min, for a total of 8 d. Rats in the SA group were perfused with SA twice a day for 8 d. The colonic histopathology was observed by hematoxylin-eosin. The levels of intestinal flora, including Bifidobacterium, Lactobacillus, Escherichia coli (E. coli), and Bacteroides fragilis (B. fragilis), were tested by real-time quantitative polymerase chain reaction to detect bacterial 16S rRNA/DNA in order to determine DNA copy numbers of each specific species. Immunohistochemical assays were used to observe the expression of TNF-α and IL-12 in the rat colons. RESULTS: HPM treatment inhibited immunopathology in colonic tissues of UC rats; the general morphological score and the immunopathological score were significantly decreased in the HPM and SA groups compared with the model group [3.5 (2.0-4.0), 3.0 (1.5-3.5) vs 6.0 (5.5-7.0), P < 0.05 for the general morphological score, and 3.00 (2.00-3.50), 3.00 (2.50-3.50) vs 5.00 (4.50-5.50), P < 0.01 for the immunopathological score]. As measured by DNA copy number, we found that Bifidobacterium and Lactobacillus, which are associated with a healthy colon, were significantly higher in the HPM and SA groups than in the model group (1.395 ± 1.339, 1.461 ± 1.152 vs 0.045 ± 0.036, P < 0.01 for Bifidobacterium, and 0.395 ± 0.325, 0.851 ± 0.651 vs 0.0015 ± 0.0014, P < 0.01 for Lactobacillus). On the other hand, E. coli and B. fragilis, which are associated with an inflamed colon, were significantly lower in the HPM and SA groups than in the model group (0.244 ± 0.107, 0.628 ± 0.257 vs 1.691 ± 0.683, P < 0.01 for E. coli, and 0.351 ± 0.181, 0.416 ± 0.329 vs 1.285 ± 1.039, P < 0.01 for B. fragilis). The expression of TNF-α and IL-12 was decreased after HPM and SA treatment as compared to UC model alone (4970.81 ± 959.78, 6635.45 ± 1135.16 vs 12333.81 ± 680.79, P < 0.01 for TNF-α, and 5528.75 ± 1245.72, 7477.38 ± 1259.16 vs 12550.29 ± 1973.30, P < 0.01 for IL-12). CONCLUSION: HPM treatment can regulate intestinal flora and inhibit the expression of TNF-α and IL-12 in the colon tissues of UC rats, indicating that HPM can improve colonic immune response.展开更多
Royal jelly (R J)from honeybee has been widely used as a health promotion supplement.The major royal jelly proteins (MRJPs)have been identified as the functional component of RJ.However,the question of whether MRJPs h...Royal jelly (R J)from honeybee has been widely used as a health promotion supplement.The major royal jelly proteins (MRJPs)have been identified as the functional component of RJ.However,the question of whether MRJPs have anti-senescence activity for human cells remains.Human embryonic lung fibroblast (HFL-I)cells were cultured in media containing no MRJPs (A),MRJPs at 0.1mg/ml (B),0.2mg/ml (C),or 0.3mg/ml (D),or bovine serum albumin (BSA)at 0.2mg/ml (E).The mean population doubling levels of cells in media B,C,D,and E were increased by 12.4%,31.2%,24.0%,and 10.4%,respectively,compared with that in medium A.The cells in medium C also exhibited the highest relative proliferation activity,the lowest senescence,and the longest telomeres.Moreover, MRJPs up-regulated the expression of superoxide dismutase-1(SOD1)and down-regulated the expression of mammalian target of rapamycin (MTOR),catenin beta like-1(CTNNB1),and tumor protein p53(TP53).Raman spectra analysis showed that there were two unique bands related to DNA synthesis materials,amide carbonyl group vibrations and aromatic hydrogens.These results suggest that MRJPs possess anti-senescence activity for the HFL-I cell line,and provide new knowledge illustrating the molecular mechanism of MRJPs as anti-senescence factors.展开更多
Camellia oil has become an important plant oil in China in recent years,but its effects on non-alcoholic fatty liver disease(NAFLD)have not been documented.In this study,the effects of camellia oil,soybean oil,and oli...Camellia oil has become an important plant oil in China in recent years,but its effects on non-alcoholic fatty liver disease(NAFLD)have not been documented.In this study,the effects of camellia oil,soybean oil,and olive oil on NAFLD were evaluated by analyzing the fatty acid profiles of the plant oils,the serum lipids and lipoproteins of rats fed different oils,and by cytological and ultrastructural observation of the rats’hepatocytes.Analysis of fatty acid profiles showed that the polyunsaturated fatty acid(PUFA)n-6/n-3 ratio was 33.33 in camellia oil,12.50 in olive oil,and 7.69 in soybean oil.Analyses of serum lipids and lipoproteins of rats showed that the levels of total cholesterol and low-density lipoprotein cholesterol in a camellia oil-fed group(COFG)were lower than those in an olive oil-fed group(OOFG)and higher than those in a soybean oil-fed group(SOFG).However,only the difference in total cholesterol between the COFG and SOFG was statistically significant.Cytological observation showed that the degree of lipid droplet(LD)accumulation in the hepatocytes in the COFG was lower than that in the OOFG,but higher than that in the SOFG.Ultrastructural analysis revealed that the size and number of the LDs in the hepatocytes of rats fed each of the three types of oil were related to the degree of damage to organelles,including the positions of nuclei and the integrity of mitochondria and endoplasmic reticulum.The results revealed that the effect of camellia oil on NAFLD in rats was greater than that of soybean oil,but less than that of olive oil.Although the overall trend was that among the three oil diets,those with a lower n-6/n-3 ratio were associated with a lower risk of NAFLD,and the effect of camellia oil on NAFLD was not entirely related to the n-6/n-3 ratio and may have involved other factors.This provides new insights into the effect of oil diets on NAFLD.展开更多
Major royal jelly protein 1(MRJP1), designated apalbumin 1, has been regarded as a freshness marker of royal jelly(RJ). A MRJP1-specific peptide(IKEALPHVPIFD) identified by bioinformatics analysis of homologous ...Major royal jelly protein 1(MRJP1), designated apalbumin 1, has been regarded as a freshness marker of royal jelly(RJ). A MRJP1-specific peptide(IKEALPHVPIFD) identified by bioinformatics analysis of homologous members of the major royal protein family was synthesized and used to raise polyclonal anti-MRJP1 antibody(antiSP-MRJP1 antibody). Western blot analysis showed that anti-SP-MRJP1 antibody only reacted with MRJP1 in RJ. In contrast, the previously reported antibody against recombinant MRJP1(anti-R-MRJP1 antibody) reacted with other members of MRJP family in RJ. Enzyme-linked immunosorbent assay(ELISA) using anti-SP-MRJP1 antibody demonstrated that MRJP1 content in RJ stored at 40 °C significantly degraded by 37.3%, 55.9%, 58.0%, 60.6%, 65.7%, 72.7%, and 73.1% at 7, 14, 21, 28, 35, 42, and 49 d, respectively, when compared with MRJP1 content in fresh RJ(0 d). Optical density analysis of MRJP bands from sodium dodecyl sulfate-polyacrylamide gel electrophoresis(SDS-PAGE) profiles demonstrated that the degradation of MRJP1, MRJP2, MRJP3, and MRJP5 in RJ was strongly and positively correlated with the period of storage(P〈0.0001). Our results indicated anti-SP-MRJP1 antibody was highly specific for MRJP1, and ELISA using the antibody is a sensitive and easy-to-use method to determine the freshness and authenticity of RJ.展开更多
Turmeric residue(TR), containing residual levels of curcumin, is a solid by-product waste generated after the extraction and separation of curcumin from turmeric root. A feeding trial was conducted to evaluate the e...Turmeric residue(TR), containing residual levels of curcumin, is a solid by-product waste generated after the extraction and separation of curcumin from turmeric root. A feeding trial was conducted to evaluate the effects of TR on the survival of Chinese soft-shelled turtles(SSTs), Pelodiscus sinensis, under a high ambient temperature. A total of 320 female SSTs were assigned randomly to two diets: basal diet(the control group, n=160) and an interventional diet supplemented with 10% TR(the TR group, n=160). Our results demonstrated that supplementation of TR increased the SST survival rate by 135.5%, and superoxide dismutase(SOD) activity of SST liver by 112.8%, and decreased the malondialdehyde(MDA) content of SST liver by 36.4%, compared to the control group. The skin of the SST fed TR showed a golden color. High-performance liquid chromatography(HPLC) analysis indicated that the concentrations of curcumin in TR and the skin of the SST fed TR were(1.69±0.30) and(0.14±0.03) μg/g, respectively. Our observation suggests that supplementation of TR increased the survival rate of SST under high ambient temperatures. We speculated that the increased survival rate and tolerance at the high ambient temperature were associated with the anti-oxidation activity of curcumin from TR. Moreover, curcumin in TR could be deposited in SST skin, which made it more favored in the market of China. Our findings provide new knowledge and evidence to effectively reuse TR as a feed additive in animal and aquatic farming.展开更多
Period estimation of X-ray pulsars plays an important role in X-ray pulsar based navigation (XPNAV). The fast Lomb periodogram is suitable for period estimation of X-ray pulsars, but its performance in terms of freq...Period estimation of X-ray pulsars plays an important role in X-ray pulsar based navigation (XPNAV). The fast Lomb periodogram is suitable for period estimation of X-ray pulsars, but its performance in terms of frequency resolution is limited by data length and observation time. Longer observation time or oversampling can be employed to improve frequency analysis results, but with greatly increased computational complexity and large amounts of sampling data. This greatly restricts real-time autonomous navigation based on X-ray pulsars. To resolve this issue, a new method based on frequency subdivision and the continuous Lomb periodogram (CLP) is proposed to improve precision of period estimation using short-time observation data. In the proposed method, an initial frequency is first calculated using fast Lomb periodogram. Then frequency subdivision is per- formed near the initial frequency to obtain frequencies with higher precision. Finally, a refined period is achieved by calculating the CLP in the obtained frequencies. Real data experiments show that when observation time is shorter than 135 s, the proposed method improves period estimation precision by 1-3 orders of magnitude compared with the fast Lomb periodogram and fast Fourier transform (FFT) methods, with only a slight increase in computational complexity. Furthermore, the proposed method performs better than efsearch (a period estimation method of HEAsoft) with lower computational complexity. The proposed method is suitable for estimating periods of X-ray pulsars and obtaining the rotation period of variable stars and other celestial bodies.展开更多
Bee venom phospholipase A2(BvPLA2) is a lipolytic enzyme that catalyzes the hydrolysis of the sn-2 acyl bond of glycerophospholipids to liberate free fatty acids and lysophospholipids.In this work,a new BvPLA2(AccPLA2...Bee venom phospholipase A2(BvPLA2) is a lipolytic enzyme that catalyzes the hydrolysis of the sn-2 acyl bond of glycerophospholipids to liberate free fatty acids and lysophospholipids.In this work,a new BvPLA2(AccPLA2) gene from the Chinese honeybee(Apis cerana cerana) venom glands was inserted into bacmid to construct a recombinant transfer vector.Tn-5B-4(Tn) cells were transfected with the recombinant bacmid DNA for expression.Sodium dodecylsulfate-polyacrylamide gel electrophoresis(SDS-PAGE) analysis revealed a double band with molecular weights of 16 and 18 kDa.Products of hexahistidine AccPLA2 fusion protein accumulated up to 5.32% of the total cellular proteins.The AccPLA2 fusion protein was cross reactive with the anti-AmPLA2(BvPLA2 of the European honeybee,Apis mellifera) polyclonal serum.The reaction resulted in a double glycosylation band,which agrees with the band generated by the native AmPLA2 in Western blot analysis.The PLA2 activity of the total extracted cellular protein in the hydrolyzing egg yolk is about 3.16 μmol/(min·mg).In summary,the recombinant AccPLA2 protein,a native BvPLA2-like structure with corresponding biological activities,can be glycosylated in Tn cells.These findings provided fundamental knowledge for potential genetic engineering to produce AccPLA2 in the pharmaceutical industry.展开更多
Royal jelly (R J) is a well-known bioactive substance. It contains large amounts of major royal jelly proteins (MRJPs), which express growth-factor-like activity in several animal and human cell lines. However, th...Royal jelly (R J) is a well-known bioactive substance. It contains large amounts of major royal jelly proteins (MRJPs), which express growth-factor-like activity in several animal and human cell lines. However, the question on whether MRJPs possess growth-factor-like activity on all types of cell cultures remains. In order to determine whether MRJPs can be used as an alternative to fetal bovine serum (FBS) in different types of human cell culture, the prolif- eration of the complex serum with different ratios of MRJPs/FBS (M/F) was evaluated on five cell lines: 293T, HFL-I, 231, HCT116, and Changliver using MTT (3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide) assay. The proliferation activity of the combination of the complex M/F serum with cytokines on the test cell lines was also measured. The results demonstrated that the complex serum with M/F 6/4 possessed the highest proliferation activity similar to or in excess of FBS. However, no activity of complex medium with M/F 6/4 was observed in 231 cells, indicating a selectivity of MRJPs on cell types. Compared with the complex medium with M/F 6/4, the complex medium with M/F 6/4 together with two cytokines, epidermal growth factor (EGF) and insulin-transferrin-selenium (ITS), pro- moted proliferations of Changliver, 293T, HCT116, and H FL-I by 18.73%-56.19% (P〈0.01). Our findings demonstrate that MRJPs could partially replace FBS in culturing many human cell lines.展开更多
基金Supported by National Natural Science Foundation of China, No. 81001549National Basic Research Program of China (973 program), No. 2009CB522900+1 种基金Shanghai Health System of Outstanding Young Talent Cultivation Program, No. XYQ2011068Shanghai Rising-Star Program, No. 10QA1406100
文摘AIM: To investigate the effect of moxibustion on intestinal flora and release of interleukin-12 (IL-12) and tumor necrosis factor-α (TNF-α) from the colon in rat with ulcerative colitis (UC). METHODS: A rat model of UC was established by local stimulation of the intestine with supernatant from colonic contents harvested from human UC patients. A total of 40 male Sprague-Dawley rats were randomly divided into the following groups: normal (sham), model (UC), herb-partition moxibustion (HPM-treated), and positive control sulfasalazine (SA-treated). Rats treated with HPM received HPM at acupuncture points ST25 and RN6, once a day for 15 min, for a total of 8 d. Rats in the SA group were perfused with SA twice a day for 8 d. The colonic histopathology was observed by hematoxylin-eosin. The levels of intestinal flora, including Bifidobacterium, Lactobacillus, Escherichia coli (E. coli), and Bacteroides fragilis (B. fragilis), were tested by real-time quantitative polymerase chain reaction to detect bacterial 16S rRNA/DNA in order to determine DNA copy numbers of each specific species. Immunohistochemical assays were used to observe the expression of TNF-α and IL-12 in the rat colons. RESULTS: HPM treatment inhibited immunopathology in colonic tissues of UC rats; the general morphological score and the immunopathological score were significantly decreased in the HPM and SA groups compared with the model group [3.5 (2.0-4.0), 3.0 (1.5-3.5) vs 6.0 (5.5-7.0), P < 0.05 for the general morphological score, and 3.00 (2.00-3.50), 3.00 (2.50-3.50) vs 5.00 (4.50-5.50), P < 0.01 for the immunopathological score]. As measured by DNA copy number, we found that Bifidobacterium and Lactobacillus, which are associated with a healthy colon, were significantly higher in the HPM and SA groups than in the model group (1.395 ± 1.339, 1.461 ± 1.152 vs 0.045 ± 0.036, P < 0.01 for Bifidobacterium, and 0.395 ± 0.325, 0.851 ± 0.651 vs 0.0015 ± 0.0014, P < 0.01 for Lactobacillus). On the other hand, E. coli and B. fragilis, which are associated with an inflamed colon, were significantly lower in the HPM and SA groups than in the model group (0.244 ± 0.107, 0.628 ± 0.257 vs 1.691 ± 0.683, P < 0.01 for E. coli, and 0.351 ± 0.181, 0.416 ± 0.329 vs 1.285 ± 1.039, P < 0.01 for B. fragilis). The expression of TNF-α and IL-12 was decreased after HPM and SA treatment as compared to UC model alone (4970.81 ± 959.78, 6635.45 ± 1135.16 vs 12333.81 ± 680.79, P < 0.01 for TNF-α, and 5528.75 ± 1245.72, 7477.38 ± 1259.16 vs 12550.29 ± 1973.30, P < 0.01 for IL-12). CONCLUSION: HPM treatment can regulate intestinal flora and inhibit the expression of TNF-α and IL-12 in the colon tissues of UC rats, indicating that HPM can improve colonic immune response.
基金Project supported by the Science and Technology Project of Zhejiang Province(No.2017C32033)the National Natural Science Foundation of China(No.3127848)
文摘Royal jelly (R J)from honeybee has been widely used as a health promotion supplement.The major royal jelly proteins (MRJPs)have been identified as the functional component of RJ.However,the question of whether MRJPs have anti-senescence activity for human cells remains.Human embryonic lung fibroblast (HFL-I)cells were cultured in media containing no MRJPs (A),MRJPs at 0.1mg/ml (B),0.2mg/ml (C),or 0.3mg/ml (D),or bovine serum albumin (BSA)at 0.2mg/ml (E).The mean population doubling levels of cells in media B,C,D,and E were increased by 12.4%,31.2%,24.0%,and 10.4%,respectively,compared with that in medium A.The cells in medium C also exhibited the highest relative proliferation activity,the lowest senescence,and the longest telomeres.Moreover, MRJPs up-regulated the expression of superoxide dismutase-1(SOD1)and down-regulated the expression of mammalian target of rapamycin (MTOR),catenin beta like-1(CTNNB1),and tumor protein p53(TP53).Raman spectra analysis showed that there were two unique bands related to DNA synthesis materials,amide carbonyl group vibrations and aromatic hydrogens.These results suggest that MRJPs possess anti-senescence activity for the HFL-I cell line,and provide new knowledge illustrating the molecular mechanism of MRJPs as anti-senescence factors.
基金Project supported by the Science and Technology Projects of Zhejiang Province(No.2017C2003),China。
文摘Camellia oil has become an important plant oil in China in recent years,but its effects on non-alcoholic fatty liver disease(NAFLD)have not been documented.In this study,the effects of camellia oil,soybean oil,and olive oil on NAFLD were evaluated by analyzing the fatty acid profiles of the plant oils,the serum lipids and lipoproteins of rats fed different oils,and by cytological and ultrastructural observation of the rats’hepatocytes.Analysis of fatty acid profiles showed that the polyunsaturated fatty acid(PUFA)n-6/n-3 ratio was 33.33 in camellia oil,12.50 in olive oil,and 7.69 in soybean oil.Analyses of serum lipids and lipoproteins of rats showed that the levels of total cholesterol and low-density lipoprotein cholesterol in a camellia oil-fed group(COFG)were lower than those in an olive oil-fed group(OOFG)and higher than those in a soybean oil-fed group(SOFG).However,only the difference in total cholesterol between the COFG and SOFG was statistically significant.Cytological observation showed that the degree of lipid droplet(LD)accumulation in the hepatocytes in the COFG was lower than that in the OOFG,but higher than that in the SOFG.Ultrastructural analysis revealed that the size and number of the LDs in the hepatocytes of rats fed each of the three types of oil were related to the degree of damage to organelles,including the positions of nuclei and the integrity of mitochondria and endoplasmic reticulum.The results revealed that the effect of camellia oil on NAFLD in rats was greater than that of soybean oil,but less than that of olive oil.Although the overall trend was that among the three oil diets,those with a lower n-6/n-3 ratio were associated with a lower risk of NAFLD,and the effect of camellia oil on NAFLD was not entirely related to the n-6/n-3 ratio and may have involved other factors.This provides new insights into the effect of oil diets on NAFLD.
基金supported by the Public Beneficial Scientific&Technical Plan of Zhejiang(No.2011C22039)the Important Scientific & Technical Plan of Zhejiang(No.2011C12023)+2 种基金the Important Scientific & Technical Innovation Project of Hangzhou(No.20131812A25)the Foundation of Fuli Institute of Food Science of Zhejiang University(No.KY201404)the National Natural Science Foundation of China(No.31271848)
文摘Major royal jelly protein 1(MRJP1), designated apalbumin 1, has been regarded as a freshness marker of royal jelly(RJ). A MRJP1-specific peptide(IKEALPHVPIFD) identified by bioinformatics analysis of homologous members of the major royal protein family was synthesized and used to raise polyclonal anti-MRJP1 antibody(antiSP-MRJP1 antibody). Western blot analysis showed that anti-SP-MRJP1 antibody only reacted with MRJP1 in RJ. In contrast, the previously reported antibody against recombinant MRJP1(anti-R-MRJP1 antibody) reacted with other members of MRJP family in RJ. Enzyme-linked immunosorbent assay(ELISA) using anti-SP-MRJP1 antibody demonstrated that MRJP1 content in RJ stored at 40 °C significantly degraded by 37.3%, 55.9%, 58.0%, 60.6%, 65.7%, 72.7%, and 73.1% at 7, 14, 21, 28, 35, 42, and 49 d, respectively, when compared with MRJP1 content in fresh RJ(0 d). Optical density analysis of MRJP bands from sodium dodecyl sulfate-polyacrylamide gel electrophoresis(SDS-PAGE) profiles demonstrated that the degradation of MRJP1, MRJP2, MRJP3, and MRJP5 in RJ was strongly and positively correlated with the period of storage(P〈0.0001). Our results indicated anti-SP-MRJP1 antibody was highly specific for MRJP1, and ELISA using the antibody is a sensitive and easy-to-use method to determine the freshness and authenticity of RJ.
基金Project supported by the National Natural Science Foundation of China(No.31271848)the Foundation of Fuli Institute of Food Science of Zhejiang University(No.KY201404),China
文摘Turmeric residue(TR), containing residual levels of curcumin, is a solid by-product waste generated after the extraction and separation of curcumin from turmeric root. A feeding trial was conducted to evaluate the effects of TR on the survival of Chinese soft-shelled turtles(SSTs), Pelodiscus sinensis, under a high ambient temperature. A total of 320 female SSTs were assigned randomly to two diets: basal diet(the control group, n=160) and an interventional diet supplemented with 10% TR(the TR group, n=160). Our results demonstrated that supplementation of TR increased the SST survival rate by 135.5%, and superoxide dismutase(SOD) activity of SST liver by 112.8%, and decreased the malondialdehyde(MDA) content of SST liver by 36.4%, compared to the control group. The skin of the SST fed TR showed a golden color. High-performance liquid chromatography(HPLC) analysis indicated that the concentrations of curcumin in TR and the skin of the SST fed TR were(1.69±0.30) and(0.14±0.03) μg/g, respectively. Our observation suggests that supplementation of TR increased the survival rate of SST under high ambient temperatures. We speculated that the increased survival rate and tolerance at the high ambient temperature were associated with the anti-oxidation activity of curcumin from TR. Moreover, curcumin in TR could be deposited in SST skin, which made it more favored in the market of China. Our findings provide new knowledge and evidence to effectively reuse TR as a feed additive in animal and aquatic farming.
基金Project supported by the National Basic Research Program(973)of China(No.2014CB340205)the National Natural Science Foundation of China(Nos.61301173 and 61473228)the Aerospaced TT&C Innovation Program of 704 Research Institute of China(No.201405B)
文摘Period estimation of X-ray pulsars plays an important role in X-ray pulsar based navigation (XPNAV). The fast Lomb periodogram is suitable for period estimation of X-ray pulsars, but its performance in terms of frequency resolution is limited by data length and observation time. Longer observation time or oversampling can be employed to improve frequency analysis results, but with greatly increased computational complexity and large amounts of sampling data. This greatly restricts real-time autonomous navigation based on X-ray pulsars. To resolve this issue, a new method based on frequency subdivision and the continuous Lomb periodogram (CLP) is proposed to improve precision of period estimation using short-time observation data. In the proposed method, an initial frequency is first calculated using fast Lomb periodogram. Then frequency subdivision is per- formed near the initial frequency to obtain frequencies with higher precision. Finally, a refined period is achieved by calculating the CLP in the obtained frequencies. Real data experiments show that when observation time is shorter than 135 s, the proposed method improves period estimation precision by 1-3 orders of magnitude compared with the fast Lomb periodogram and fast Fourier transform (FFT) methods, with only a slight increase in computational complexity. Furthermore, the proposed method performs better than efsearch (a period estimation method of HEAsoft) with lower computational complexity. The proposed method is suitable for estimating periods of X-ray pulsars and obtaining the rotation period of variable stars and other celestial bodies.
基金Project (No 2007AA10Z324) supported by the National High-Tech Research and Development Program (863) of China
文摘Bee venom phospholipase A2(BvPLA2) is a lipolytic enzyme that catalyzes the hydrolysis of the sn-2 acyl bond of glycerophospholipids to liberate free fatty acids and lysophospholipids.In this work,a new BvPLA2(AccPLA2) gene from the Chinese honeybee(Apis cerana cerana) venom glands was inserted into bacmid to construct a recombinant transfer vector.Tn-5B-4(Tn) cells were transfected with the recombinant bacmid DNA for expression.Sodium dodecylsulfate-polyacrylamide gel electrophoresis(SDS-PAGE) analysis revealed a double band with molecular weights of 16 and 18 kDa.Products of hexahistidine AccPLA2 fusion protein accumulated up to 5.32% of the total cellular proteins.The AccPLA2 fusion protein was cross reactive with the anti-AmPLA2(BvPLA2 of the European honeybee,Apis mellifera) polyclonal serum.The reaction resulted in a double glycosylation band,which agrees with the band generated by the native AmPLA2 in Western blot analysis.The PLA2 activity of the total extracted cellular protein in the hydrolyzing egg yolk is about 3.16 μmol/(min·mg).In summary,the recombinant AccPLA2 protein,a native BvPLA2-like structure with corresponding biological activities,can be glycosylated in Tn cells.These findings provided fundamental knowledge for potential genetic engineering to produce AccPLA2 in the pharmaceutical industry.
基金Project supported by the National Natural Science Foundation of China(No.31271848)the Important Scientific&Technical Innovation Project of Hangzhou(No.20131812A25)the Foundation of Fuli Institute of Food Science of Zhejiang University(No.KY201404),China
文摘Royal jelly (R J) is a well-known bioactive substance. It contains large amounts of major royal jelly proteins (MRJPs), which express growth-factor-like activity in several animal and human cell lines. However, the question on whether MRJPs possess growth-factor-like activity on all types of cell cultures remains. In order to determine whether MRJPs can be used as an alternative to fetal bovine serum (FBS) in different types of human cell culture, the prolif- eration of the complex serum with different ratios of MRJPs/FBS (M/F) was evaluated on five cell lines: 293T, HFL-I, 231, HCT116, and Changliver using MTT (3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide) assay. The proliferation activity of the combination of the complex M/F serum with cytokines on the test cell lines was also measured. The results demonstrated that the complex serum with M/F 6/4 possessed the highest proliferation activity similar to or in excess of FBS. However, no activity of complex medium with M/F 6/4 was observed in 231 cells, indicating a selectivity of MRJPs on cell types. Compared with the complex medium with M/F 6/4, the complex medium with M/F 6/4 together with two cytokines, epidermal growth factor (EGF) and insulin-transferrin-selenium (ITS), pro- moted proliferations of Changliver, 293T, HCT116, and H FL-I by 18.73%-56.19% (P〈0.01). Our findings demonstrate that MRJPs could partially replace FBS in culturing many human cell lines.