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Effects of Ginkgo biloba extract EGb761 on neural differentiation of stem cells offer new hope for neurological disease treatment 被引量:6
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作者 Chao Ren Yong-Qiang Ji +5 位作者 Hong Liu Zhe Wang Jia-Hui Wang Cai-Yi Zhang Li-Na Guan Pei-Yuan Yin 《Neural Regeneration Research》 SCIE CAS CSCD 2019年第7期1152-1157,共6页
Stem cell transplantation has brought new hope for the treatment of neurological diseases.The key to stem cell therapy lies in inducing the specific differentiation of stem cells into nerve cells.Because the different... Stem cell transplantation has brought new hope for the treatment of neurological diseases.The key to stem cell therapy lies in inducing the specific differentiation of stem cells into nerve cells.Because the differentiation of stem cells in vitro and in vivo is affected by multiple factors,the final differentiation outcome is strongly associated with the microenvironment in which the stem cells are located.Accordingly,the optimal microenvironment for inducing stem cell differentiation is a hot topic.EGb761 is extracted from the leaves of the Ginkgo biloba tree.It is used worldwide and is becoming one of the focuses of stem cell research.Studies have shown that EGb761 can antagonize oxygen free radicals,stabilize cell membranes,promote neurogenesis and synaptogenesis,increase the level of brain-derived neurotrophic factors,and replicate the environment required during the differentiation of stem cells into nerve cells.This offers the possibility of using EGb761 to induce the differentiation of stem cells,facilitating stem cell transplantation.To provide a comprehensive reference for the future application of EGb761 in stem cell therapy,we reviewed studies investigating the influence of EGb761 on stem cells.These started with the composition and neuropharmacology of EGb761,and eventually led to the finding that EGb761 and some of its important components play important roles in the differentiation of stem cells and the protection of a beneficial microenvironment for stem cell transplantation. 展开更多
关键词 nerve REGENERATION GINKGO biloba extract GINKGOLIDE B traditional Chinese medicine STEM cells induction of differentiation STEM cell transplantation synaptic plasticity pharmacological effect NEUROLOGICAL diseases nervous systems neural REGENERATION
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Theory of Electromagnetism and Gravity —Modeling Earth as a Rotating Solenoid Coil
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作者 Greg Poole 《Journal of High Energy Physics, Gravitation and Cosmology》 2017年第4期663-692,共30页
Presented in this manuscript are conventional electrical engineering tools to model the earth as a rotating electrical machine. Calculations using known parameters of the earth and measured field data has resulted in ... Presented in this manuscript are conventional electrical engineering tools to model the earth as a rotating electrical machine. Calculations using known parameters of the earth and measured field data has resulted in new understanding of the earth’s electrical system and gyroscopic rotation. The material makeup of the inner earth is better understood based on derived permeability and permittivity constants. The planet has been modeled as simple coils and then as a parallel impedance circuit which has led to fundamental insight into planetary speed control and RLC combination for Schumann Resonance of 7.83 Hz. Torque and Voltage Constants and the inverse Speed Constant are calculated using three methods and all compare favorably with Newton’s Gravitational Constant. A helical resonator is referenced and Schumann’s Resonant ideal frequency is calculated and compared with others idealism. A new theory of gravity based on particle velocity selector at the poles is postulated. Two equations are presented as the needed links between Faraday’s electromagnetism and Newtonian physics. Acceleration and Deceleration of earth is explained as a centripetal governor. A new equation for planetary attraction and the attraction of atomic matter is theorized. Rotation of the earth’s electrical coil is explained in terms of the Richardson effect. Electric power transfer from the sun to the planets is proposed via Flux Transfer Events. The impact of this evolving science of electromagnetic modeling of planets will be magnified as the theory is proven, and found to be useful for future generations of engineers and scientists who seek to discover our world and other planets. 展开更多
关键词 Ampere Biot-Savart CENTRIPETAL Acceleration CENTRIPETAL GOVERNOR Dynamo EARTH Einstein-de Haas effect Electric Field Electromagnetism Flux Transfer Events GOVERNOR Control GRAVITY Gravitational CONSTANT Helical Resonator Lenz Law Lorentz Lightning Magnetic Field Motor CONSTANT Parallel Impedance Planet SPEED Control Schumann Resonance Richardson effect Solenoid SPEED CONSTANT Solar Power System Torque CONSTANT Velocity Selector Voltage CONSTANT
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Hypoglycaemic effect of Berberis vulgaris L.in normal and streptozotocin-induced diabetic rats 被引量:6
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作者 Nawel Meliani Mohamed El Amine Dib +1 位作者 Hocine Allali Boufeldja Tabti 《Asian Pacific Journal of Tropical Biomedicine》 SCIE CAS 2011年第6期468-471,共4页
Objective:To achieve a primary pharmacological screening contained in the aqueous extract of Berberis vulgaris(B.vulgaris) and to examine the hypoglycaemic effect and biochemical parameters of aqueous and saponins ext... Objective:To achieve a primary pharmacological screening contained in the aqueous extract of Berberis vulgaris(B.vulgaris) and to examine the hypoglycaemic effect and biochemical parameters of aqueous and saponins extract on groups of rats rendered diabetic by injection of streptozotocin.Methods:The phytochemicol tests to detect the presence of different compounds were based on the visual observation of color change or formation of precipitate after the addition of specific reagents.Diabetes was induced in rats by intraperitoneal(i.p.) injection of streptozotocin(STZ) at a dose of 65 mg/kg bw.The fasting blood glucose levels were estimated by glucose oxidase-peroxidase reactive strips(Dextrostix,Bayer Diagnostics).Blood samples were taken by cutting the tip of the tail.Serum cholesterol and serum triglycerides were estimated by enzymatic DHBS colorimetric method.Results:Administration of 62.5 and 2S.0 mg/kg of saponins and aqueous extract respectively in normal rats group shows a significant hypoglycemic activity(32.33%and 40.17%respectively) during the first week.However,diabetic group treated with saponin extract produced a maximum fall of 73.1%and 76.03%at day 1 and day 21 compared to the diabetics control.Also,blood glucose levels of the diabetic rats treated with aqueous extract showed decrease of 78.79%on the first day and the effect remains roughly constant during 3 week. Both extracts also declined significantly biochemical parameters(20.77%-49.00%).The control in the loss of body weight was observed in treated diabetic rats as compared to diabetic controls. Conclusions:These results demonstrated significant antidiabetic effects and showed that serum cholesterol and serum triglycerides levels were decreased,significantly,consequently this plant might be of value in diabetes treatment. 展开更多
关键词 BERBERIS VULGARIS L. ANTIDIABETIC activity Streptozotocin-induced diabetes Saponins Aqueous extract Photochemical screening HYPOGLYCAEMIC effect Biochemical parameters Cholesterol TRIGLYCERIDES Glucose oxidase-peroxidase Colorimetric method
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Effects of aminoguanidine on nitric oxide production induced by inflammatory cytokines and endotoxin in cultured rat hepatocytes 被引量:20
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作者 Guo Liang Zhang Ye Hong Wang Hui Ling Teng Zhi Bin Lin Department of Pharmacology,School of Basic Medical Sciences,Beijing University,Beijiog 100083,ChinaDr.Guo Liang Zhang graduated from Xinxiang Medical College in 1982,got Ph.D.at Nagoya City University Medical School,Japan in 1994,finished postdoctoral research at Beijing Medical Univcrsity in 1996,now an associate professor of pharmacology,specialized in hepatic pharmacology,having 15 papers published. 《World Journal of Gastroenterology》 SCIE CAS CSCD 2001年第3期331-334,共4页
AIM: To study the effects of aminoguanidine (AG) and two L-arginine analogues N(omega)-nitro-L-arginine methyl ester (L-NAME) and N(omega)-nitro-L-arginine (L-NNA) on nitric oxide (NO) production induced by cytokines ... AIM: To study the effects of aminoguanidine (AG) and two L-arginine analogues N(omega)-nitro-L-arginine methyl ester (L-NAME) and N(omega)-nitro-L-arginine (L-NNA) on nitric oxide (NO) production induced by cytokines (TNF-alpha, IL-1 beta, and IFN-gamma) and bacterial lipopolysaccharide (LPS) mixture (CM) in the cultured rat hepatocytes, and examine their mechanisms action. METHODS: Rat hepatocytes were incubated with AG, L-NAME, L-NNA, Actinomycin D (ActD) and dexamethasone in a medium containing CM (LPS plus TNF-alpha, IL-1 beta, and IFN-gamma) for 24h. NO production in the cultured supernatant was measured with the Griess reaction. Intracellular cGMP level was detected with radioimmunoassy. RESULTS: NO production was markedly blocked by AG and L-NAME in a dose-dependent manner under inflammatory stimuli condition triggered by CM in vitro. The rate of the maximum inhibitory effects of L-NAME (38.9%) was less potent than that obtained with AG(53.7%, P 【 0.05). There was no significant difference between the inhibitory effects of AG and two L-arginine analogues on intracellular cGMP accumulation in rat cultured hepatocytes. Non-specific NOS expression inhibitor dexamethasone (DEX)and iNOS mRNA transcriptional inhibitor ActD also significantly inhibited CM-induced NO production. AG(0.1 mmol x L(-1)) and ActD (0.2 ng x L(-1)) were equipotent in decreasing NO production induced by inflammatory stimuli in vitro, and both effects were more potent than that induced by non-selectivity NOS activity inhibitor L-NAME (0.1 mmol x L(-1)) under similar stimuli conditions (P【0.01). CONCLUSION: AG is a potent selective inhibitor of inducible isoform of NOS,and the mechanism of action may be not only competitive inhibition in the substrate level, but also the gene expression level in rat hepatocytes. 展开更多
关键词 Animals Antineoplastic Agents Cells Cultured Comparative Study Cyclic GMP Cytokines DACTINOMYCIN Dexamethasone Enzyme Inhibitors Glucocorticoids GUANIDINES Hepatocytes Interferon Type II INTERLEUKIN-1 LIPOPOLYSACCHARIDES Male NG-Nitroarginine Methyl Ester Nitric Oxide Nitric Oxide Synthase inhibitors Nitroarginine Protein Synthesis Inhibitors RATS Rats Wistar Research Support Non-U.S. Gov't Tumor Necrosis Factor-alpha
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A Pragmatic Approach to Coping with Matrix Effects during ICP-MS Analysis of Trace Elements in Silicate Rocks and Calibration of REE Interferences
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作者 C. Michael B. Henderson Paul R. Lythgoe Karen J. Theis 《Journal of Geoscience and Environment Protection》 2019年第3期82-125,共44页
Operating an Agilent 7700X ICP-MS spectrometer under robust plasma conditions (1550 W) with a He-filled octopole collision cell and analysing solutions (?1 total dissolved solids) still suffered analyte peak suppressi... Operating an Agilent 7700X ICP-MS spectrometer under robust plasma conditions (1550 W) with a He-filled octopole collision cell and analysing solutions (?1 total dissolved solids) still suffered analyte peak suppression due to matrix effects. International reference rocks BCR-1, BHVO-1, AGV-1, G-2 and BCR-2 all showed count rate reductions for 36 elements (mass range 7Li to 238U) averaging ~10% but with no dependence on isotope mass. Use of an internal standard (103Rh) and/or using a ten-fold dilution of sample solutions reduced these effects but problems with reduced count rates combined with larger errors for some elements introduced other problems. The best approach was to normalise the count rates for each element in the other samples against those for BCR-1 as an external standard;thus the count suppression due to the matrix effect is corrected for each individual element. This approach provides standardization “traceability” in line with the ERM ISO/IEC requirement. Experiments are also reported on quantifying the proportions of Ba and selected REE oxide/hydroxide components versus parent isotopes (XO/X and XOH/X). This information is essential for correcting peak interferences on higher mass number REE for the rock samples, and equations are developed to use measured CeO/Ce and CeOH/Ce ratios to predict such values for any other member of the REE suite. Concentrations obtained show excellent agreement with recommended values for the international reference materials especially for the REE. Robust data are also provided for two other standard rocks: nepheline syenite STM-1 and quartz syenite CAAS-1;the latter shows exceptional enrichments of Zr, REE, Th, and U. 展开更多
关键词 ICP-MS Dilution Minimises Matrix effects BCR-1 as an External Standard New Analyses for STM-1 and CAAS-1 CALIBRATION of X-O/OH INTERFERENCES on REE Elements
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The assessment of time dependent flow of Williamson fluid with radiative blood flow against a wedge 被引量:1
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作者 K.Subbarayudu S.Suneetha P.Bala Anki Reddy 《Propulsion and Power Research》 SCIE 2020年第1期87-99,共13页
The present pagination reports both Brownian diffusion and thermophoresis aspects subject to magneto hydrodynamic Williamson fluid model.Assuming the flow is unsteady and blood is treated as Williamson fluid over a we... The present pagination reports both Brownian diffusion and thermophoresis aspects subject to magneto hydrodynamic Williamson fluid model.Assuming the flow is unsteady and blood is treated as Williamson fluid over a wedge with radiation.The governing equations are transformed into ordinary differential equations by using similarity variables.The analytical solutions of the transformed governing equations are obtained by using the RK 4th order method along with shooting technique solver.The effects of various physical parameters such as Hartmann number,local Weissenberg number,radiation parameter,unsteadiness parameter,Prandtl number,Lewis number,Brownian diffusion,thermophoresis,wedge angle parameter,moving wedge parameter,on velocity,temperature,concentration,skin friction,heat transfer rate and mass transfer rate have been discussed in detail.The velocity and temperature profile deprives for larger We and an opposite trend is observed for concentration.The radiation parameter is propositional to temperature and a counter behaviour is observed for Pr. 展开更多
关键词 The present pagination reports both Brownian diffusion and thermophoresis aspects subject to magneto hydrodynamic WILLIAMSON fluid model. Assuming the flow IS unsteady and blood IS treated as WILLIAMSON fluid over a WEDGE with radiation. The governing EQUATIONS are transformed into ordinary differential EQUATIONS by using similarity variables. The analytical solutions of the transformed governing EQUATIONS are obtained by using the RK 4th order method along with shooting technique solver. The effects of various physical parameters such as Hartmann NUMBER local Weissenberg NUMBER radiation PARAMETER unsteadiness PARAMETER Prandtl NUMBER Lewis NUMBER Brownian diffusion thermophoresis WEDGE angle PARAMETER moving WEDGE PARAMETER on velocity temperature concentration skin friction heat transfer rate and mass transfer rate have been discussed in detail. The velocity and temperature profile deprives for larger We and an opposite trend IS observed for concentration. The radiation PARAMETER IS propositional to temperature and a counter behaviour IS observed for Pr.
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温度和热驯化对胡氏大生熊虫运动行为的影响 被引量:4
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作者 李晓晨 王立志 《动物学报》 SCIE CAS CSCD 北大核心 2005年第3期516-520,共5页
The beneficial acclimation hypothesis (BAH) predicts that animals acclimated to a particular temperature have enhanced performance or fitness at that temperature in comparison with animals acclimated to other temperat... The beneficial acclimation hypothesis (BAH) predicts that animals acclimated to a particular temperature have enhanced performance or fitness at that temperature in comparison with animals acclimated to other temperatures. The BAH has been tested by a variety of empirical examinations, and was rejected by some of them. In order to provide new evidences for the BAH, the effects of acute and acclimation temperature (AT) on locomotor performance of Macrobiotus hufelandi (Tardigrada: Macrobiotidae) were investigated. The tardigrades were collected from Nanwutai, Qinling Mountains which traverse from west to east in central China. The subjects were acclimated to either 2℃ or 22℃ for 2 weeks. The animal was transferred onto a frosted slide and allowed to walk freely at the performance temperature (PT) 2℃ or 22℃. Only one individual was tested per test bout, which lasted from three to five minutes. To avoid occurrence of thermal acclimation effect, the standard adaptation time was limited to 1.5 min. Each subject was tested for once at the same PT, and was tested only at one PT. A total of 25 individuals were tested and measured at the same PT. The locomotor performance of the animals was recorded with a digital video camera mounted on a microscope at 4×10 amplification and replayed on a PC. Every subject was identified. Walking speed (WS) and percentage of time moving (PTM) at both PTs (2℃ or 22℃) were selected as the rate parameters of locomotor performance. The two-way repeated measures ANOVA with a significance level of α= 0.05 and Duncan multiple range test were used to analyze the data. WS of the animals acclimated to and tested at the same temperatures was significantly faster than that for animals acclimated to and tested at the different temperatures, similarly, PTM of the animals acclimated to 22℃ and tested at 22℃ was significantly greater than PTM of animals acclimated to 22℃ and tested at 2℃, which indicated that the animals acclimated to a particular temperature have enhanced locomotor performance in that temperature relative to the animals acclimated to that temperature in other thermal environment. WS of the animals acclimated to 22℃ and tested at 22℃ was significantly faster than WS of animals acclimated to 2℃ and tested at 22℃, PTM of the animals acclimated to 22℃ and tested at 22℃ was significantly greater than PTM of animals acclimated to 2℃ and tested at 22℃. These results supported the BAH. It could be concluded that the PT and thermal acclimation as well as the interaction between the PT and AT significantly influence the locomotor performance of M.hufelandi, and that, despite the existence of a few results of this study that don’t support the BAH, some results of this study support for this hypothesis, and that the animals acclimated to a particular temperature have enhanced locomotor performance in that temperature relative to the animals acclimated to that temperature in other thermal environment, implying that any performance temperature that deviates from the acclimation temperature could cause the reduction of the walking speed which is closely related to the fitness of the M.hufelandi. 展开更多
关键词 standard performa multiple effects central digital speed with camera the was test time The SLIDE total video level range PTM east walk one at in new PTS be
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Prevalence of Dyspareunia and Its Effect on Sexual Life among Gynaecological Clinic Attendees in Alex Ekwueme Federal University Teaching Hospital Abakaliki, Nigeria
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作者 Sunday Uchenna Asogwa Johnbosco Ifunanya Nwafor +3 位作者 Ayodele Adegbite Olaleye Darlington-Peter Chibuzor Ugoji Chuka Nobert Obi Chukwunenye Chukwu Ibo 《Advances in Sexual Medicine》 2019年第4期110-119,共10页
Introduction: Dyspareunia is one of the most common complaints in gynae-cologic practice with tremendous effect on both quality of life and sexual rela-tionship of women. Objectives: To determine the prevalence of dys... Introduction: Dyspareunia is one of the most common complaints in gynae-cologic practice with tremendous effect on both quality of life and sexual rela-tionship of women. Objectives: To determine the prevalence of dyspareunia and its effect on sexual life among gynaecology clinic attendees in Alex Ekwueme Federal University Teaching Hospital, Abakaliki. Materials and Methods: A cross-sectional study was conducted on consenting participants between 12th May 2016 and 25th July 2016. Anonymous self-administered questionnaires were used collection information on dyspareunia and its effect on sexual life at the Gynaecology clinic. The data was analyzed using Epiinfo version 7.1.5. Results: One hundred and four (104) women participated in this study. Most of the women studied were Igbos (95.19%), and were mainly between the age ranges of 21 - 30 years (66.35%). Most of them were married (89.42%), and were also mainly of the Pentecostal denomination (40.78%). The mean age at coitarche was 20.6 ± 3.95 years. Prevalence of dyspareunia was 36% and only 16% sought medical help. The various responses to dyspareunia were avoidance of sex 11%, reduced frequency of intercourse 8%, less desire for sex 19%, while majority of women with dyspareunia tolerated it (62%). Conclusion: The prevalence of dyspareunia is high in our society afflicting young women in their reproductive years with associated enormous stress on their sexual life. 展开更多
关键词 PREVALENCE of DYSPAREUNIA and Its effect on Sexual Life among GYNAECOLOGICAL CLINIC Attendees in Alex Ekwueme FEDERAL University Teaching Hospital Abakaliki NIGERIA
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Protective effects of organic extracts of Alpinia oxyphylla against hydrogen peroxide-induced cvtotoxicitv in PC12 cells 被引量:5
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作者 Li-Hong Duan Meng Li +10 位作者 Chun-Bao Wang Qing-Mei Wang Quan-Quan Liu Wan-Feng Shang Ya-Jin Shen Zhuo-Hua Lin Tong-Yang Sun Zheng-Zhi Wu Ying-Hong Li Yu-Long Wang Xun Luo 《Neural Regeneration Research》 SCIE CAS CSCD 2020年第4期682-689,共8页
Alpinia oxyphylla,a traditional herb,is widely used for its neuroprotective,antioxidant and memory-improving effects.However,the neuroprotective mechanisms of action of its active ingredients are unclear.In this study... Alpinia oxyphylla,a traditional herb,is widely used for its neuroprotective,antioxidant and memory-improving effects.However,the neuroprotective mechanisms of action of its active ingredients are unclear.In this study,we investigated the neuroprotective effects of various organic extracts of Alpinia oxyphylla on PC12 cells exposed to hydrogen peroxide-induced oxidative injury in vitro.Alpinia oxyphylla was extracted three times with 95%ethanol(representing extracts 1–3).The third 95%ethanol extract was dried and resuspended in water,and then extracted successively with petroleum ether,ethyl acetate and n-butanol(representing extracts 4–6).The cell counting kit-8 assay and microscopy were used to evaluate cell viability and observe the morphology of PC12 cells.The protective effect of the three ethanol extracts(at tested concentrations of 50,100 and 200μg/mL)against cytotoxicity to PC12 cells increased in a concentration-dependent manner.The ethyl acetate,petroleum ether and n-butanol extracts(each tested at 100,150 and 200μg/mL)had neuroprotective effects as well.The optimum effective concentration ranged from 50–200μg/mL,and the protective effect of the ethyl acetate extract was comparatively robust.These results demonstrate that organic extracts of Alpinia oxyphylla protect PC12 cells against apoptosis induced by hydrogen peroxide.Our findings should help identify the bioactive neuroprotective components in Alpinia oxyphylla. 展开更多
关键词 active INGREDIENTS ALPINIA oxyphylla apoptosis ethanol crude extract fraction hydrogen PEROXIDE nerve regeneration NEUROPROTECTIVE agent NEUROPROTECTIVE effects PC12 cells traditional HERB
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Effects of Streptomyces <i>Biofertilizer</i>to Soil Fertility and Rhizosphere’s Functional Biodiversity of Agricultural Plants 被引量:3
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作者 Tinatin Doolotkeldieva Saykal Bobusheva Maxabat Konurbaeva 《Advances in Microbiology》 2015年第7期555-571,共17页
In the present study, a biofertilizer on the basis of Streptomyces fumanus gn-2 was used for the treatment of wheat and soybean seeds (dose 104 spore/ml) before planting them in soil with low fertility in order to det... In the present study, a biofertilizer on the basis of Streptomyces fumanus gn-2 was used for the treatment of wheat and soybean seeds (dose 104 spore/ml) before planting them in soil with low fertility in order to determine the effect of this biological agent on germination rate;the growth of seedlings, shoots, and the maturation phase of plants;the rhizosphere’s functional biodiversity;and the resistance of these plants to pathogens. Seeds were soaked in the suspension for a period of two or three hours. During the growing season of the crop, no additional fertilizing and spraying of a biopesticide against diseases or pests occurred. Despite the soil having low fertility, low quantities of organic matter, and not having been before used for the cultivation of agricultural plants, this biofertilizer showed a strong stimulatory effect on the growth of seeds and seedlings of wheat and soybeans. The average germination and seed vigor increased by 1.5 - 2.0 times, and the phenophases were accelerated to three to five days. In all phases of vegetation, the ammonifying bacteria in the presence of an antagonist (a biological agent) developed rapidly and were constantly present in significant numbers in the rhizosphere. Streptomyces fumanus introduced into non-sterile soil entered into competition with the local soil microflora and had the ability to colonize the rhizosphere system of plants. The use of a formulation of Streptomyces gn-2 has improved the composition of rhizosphere microflora, attracting saprophytic microorganisms: ammonificators and oligotrophs. The presence of the biocontrol microorganism Streptomyces fumanus in the rhizosphere plays an important role in enhancing the growth and development of useful groups, such as nitrogen-fixing bacteria. 展开更多
关键词 A Low Fertility Soil A BIOFERTILIZER Streptomyces fumanus gn-2 Wheat and Soybean Seeds Stimulatory effect on Seed Germination Rhizospheres FUNCTIONAL BIODIVERSITY
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Dynamic Analysis of Soil Structure Interaction Effect on Multi Story RC Frame
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作者 Hailu Getachew Kabtamu Gang Peng Denghong Chen 《Open Journal of Civil Engineering》 2018年第4期426-446,共21页
In this study dynamic analysis of Soil Structure Interaction (SSI) effect on multi story reinforced concrete (RC) frame founded on soft soil (flexible base) is made and compared with fixed base. Two model 2D RC frames... In this study dynamic analysis of Soil Structure Interaction (SSI) effect on multi story reinforced concrete (RC) frame founded on soft soil (flexible base) is made and compared with fixed base. Two model 2D RC frames with 7 and 12 story are selected for analysis. Winkler Spring and half space direct method models are used for flexible base for the frames founded on two types of soft soils with shear velocity Vs < 150 m/s Asper Seismic Codes of Chinese GB50011-2010 Soil IV and Ethiopian ES8-2015 soil D. The frames are subjected to strong ground motion matched to response spectrums of soft soil of Chinese GB50011-2010 and Ethiopian ES8-2015 for linear time history analysis. The dynamic analysis result shows Spring and Fixed base mass participation 90% reaches in 2 or 3 modes but in direct method 11 to 30 modes for story 12 and 7 respectively. However, both flexible base models have bigger fundamental period of vibration and inter story drift but smaller base shear than fixed base. In addition, within the flexible base models the inter-story drift, second order effect (P-Δ) and Story shear distribution are different along the height of frames. The spring model shows larger Story drift and second order effect (P-Δ) at the bottom of Story for both soft soils types. On the other hand, half space direct method model indicates value reverse to spring model;it gives bigger Story drift and P-Δ effect in the top stories than fixed base. Finally, this study concludes that base shear reduction due to SSI may not be always beneficial. Because the gravity load is constant in both fixed and flexible bases that cause bigger P-Δ effect at the bottom stories due to increase, inter story drift and decrease story shear in flexible base. 展开更多
关键词 Soil Structure Interaction Dynamic Analysis Fixed BASE Flexible BASE Direct Method WINKLER Spring PERIOD of Vibration STORY SHEAR STORY DRIFT and P-Δ effect
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Temperature Effects on the Electrical Performance of Large Area Multicrystalline Silicon Solar Cells Using the Current Shunt Measuring Technique 被引量:1
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作者 Hala Mohamed Abdel Mageed Ahmed Faheem Zobaa +2 位作者 Mohamed Helmy Abdel Raouf Abla Hosni Abd El-Rahman Mohamed Mamdouh Abdel Aziz 《Engineering(科研)》 2010年第11期888-894,共7页
The temperature effects on the electrical performance of a large area multicrystalline silicon solar cell with back-contact technology have been studied in a desert area under ambient conditions using the current shun... The temperature effects on the electrical performance of a large area multicrystalline silicon solar cell with back-contact technology have been studied in a desert area under ambient conditions using the current shunt measuring technique. Therefore, most of the problems encountered with traditional measuring techniques are avoided. The temperature dependency of the current shunt from 5oC up to 50oC has been investigated. Its temperature coefficient proves to be negligible which means that the temperature dependency of the solar cell is completely independent of the current shunt. The solar module installed in a tilted position at the optimum angle of the location, has been tested in two different seasons (winter and summer). The obtained solar cell short circuit current, open circuit voltage and output power are correlated with the measured incident radiation in both seasons and all results are discussed. 展开更多
关键词 Large Area MULTICRYSTALLINE Silicon Solar Cell CURRENT SHUNT Measuring Technique Temperature effects SHORT CIRCUIT CURRENT Open CIRCUIT Voltage Accumulated Power INCIDENT Radiation
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Dynamic Promotional Resource Allocation for Segment Specific and Spectrum Effect of Promotion for a Product Line Incorporating Repeat Purchase Behavior 被引量:1
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作者 Prakash Chandra Jha Prerna Manik Anshu Gupta 《American Journal of Operations Research》 2013年第3期350-362,共13页
Promotion is an essential element in the marketing mix. It is used by businesses to inform, influence and persuade customers to adopt the products and services they offer. Without promotion, business would be stagnant... Promotion is an essential element in the marketing mix. It is used by businesses to inform, influence and persuade customers to adopt the products and services they offer. Without promotion, business would be stagnant and lack substantial growth because the brands would have low visibility in the market. Moreover, today’s vast and assorted markets comprise of customers with different needs and varied behavior. So it is rarely possible for companies to satisfy all customers by treating them alike. Thus there arises a need to divide the market into segments having customers with similar traits/characteristics. After identifying appropriate market segments, firms can design differentiated promotional campaigns for each segment. At the same time there can be a mass market promotional campaign that reaches different segments with a fixed spectrum. Also since promotional effort resources are limited, one must use them judiciously. In this paper, we formulate mathematical programming problem under repeat purchase scenario, which optimally allocates mass promotional effort resources and differentiated promotional effort resources across the segments dynamically in order to maximize the overall sales obtained from multiple products of a product line under budgetary and minimum sales aspiration level constraint on each product under consideration in each segment. The planning horizon is divided into multi periods, the adoption pattern of each product in each segment is observed in every subinterval and accordingly promotional effort allocations are determined for the next period till we reach the end of planning period. The optimization model has been further extended to incorporate minimum aspiration level constraints on total sales for each product under consideration from all the segments taken together. The non linear programming problem so formulated is solved using differential evolution approach. A numerical example has been discussed to illustrate applicability of the model. 展开更多
关键词 MARKET Segmentation DIFFERENTIATED MARKET PROMOTION Mass MARKET PROMOTION SPECTRUM effect Promotional Effort Allocation REPEAT Purchase Product Line Non Linear Programming Problem Differential Evolution
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Antiamylase Potential of Telfairia occidentalis Leaves from Cameroon and Effect of Their Dietary Supplementation on Fasting Blood Glucose in Wistar Rats
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作者 Palla Nyamen Corine Leslie Etoundi Omgba Cunégonde Blanche Gouado Gouado Inocent 《Journal of Biosciences and Medicines》 2015年第9期61-66,共6页
The study of edible plants, especially in developing countries, might provide more affordable means for the management of diabetes. Telfairia occidentalis is one of the plants whose leaves are commonly consumed in Cam... The study of edible plants, especially in developing countries, might provide more affordable means for the management of diabetes. Telfairia occidentalis is one of the plants whose leaves are commonly consumed in Cameroon. This work hereby studied the antiamylasic potential of its aqueous leaves extract and the effect of its dietary supplementation on fasting blood glucose in Wistar rats. An aqueous extract (1:6) was prepared from shed-dried T. occidentalis leaves by maceration. Its antiamylase activity was evaluated in vitro and a phytochemical screening was realized. Its acute toxicity and its effect on an oral glucose tolerance test (OGTT) were evaluated in rats. The effect of T. occidentalis leaves dietary supplementation (10%) on fasting blood glucose was studied for 28 days in rats fed with carbohydrate enriched diet, using Glibenclamide (0.3 mg/kg body weight) as reference hypoglycemic drug. Results showed that there was total inhibition of α-amylase activity in vitro by T. occidentalis aqueous leaves extract at 0.075 mg/ml. The presence of tannins, flavonoids and anthocyanins was revealed by the phytochemical screening. No sign of toxicity was observed in rats after an oral administration of the extract at 2000 mg/kg body weight. The extract significantly hindered a rise in blood glucose at 400 mg/kg body weight during an oral glucose tolerance test. Dietary supplementation with T. occidentalis leaves caused a significant decrease (p < 0.05) in fasting blood glucose as compared to the positive control. Telfairia occidentalis leaves and their aqueous extract could be used in the management of hyperglycemia and diabetes. 展开更多
关键词 Antiamylase POTENTIAL of Telfairia OCCIDENTALIS LEAVES from Cameroon and effect of THEIR Dietary Supplementation on FASTING Blood Glucose in Wistar Rats
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On the Isotope-Like Effect for High-T<sub>c</sub>Superconductors in the Scenario of 2-Phonon Exchange Mechanism for Pairing
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作者 G. P. Malik 《World Journal of Condensed Matter Physics》 2018年第3期109-114,共6页
By generalizing the isotope effect for elemental superconductors (SCs) to the case of pairing in the 2-phonon exchange mechanism for composite SCs, we give here an explanation of the well-known increase in the critica... By generalizing the isotope effect for elemental superconductors (SCs) to the case of pairing in the 2-phonon exchange mechanism for composite SCs, we give here an explanation of the well-known increase in the critical temperature (Tc) of Bi2Sr2CaCu2O8 from 95 K to 110 K and of Bi2Sr2Ca2Cu3O10 from 105 to 115 - 125 K when Bi and Sr in these are replaced by Tl and Ba, respectively. On this basis, we also give the estimated Tcs of some hypothetical SCs, assuming that they may be fabricated by substitutions similar to Bi → Tl and Sr → Ba. 展开更多
关键词 Isotope-Like effect 2-Phonon Exchange Mechanism Bi- and Tl-Based High-Tc SCS Suggestions for New Substitutions for Further Enhancement of Tc of the Bi-Based SCS
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Theory of a Mach Effect Thruster I
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作者 Heidi Fearn Adam Zachar +1 位作者 Keith Wanser James Woodward 《Journal of Modern Physics》 2015年第11期1510-1525,共16页
The Mach Effect Thruster (MET) is a propellant—less space drive which uses Mach’s principle to produce thrust in an accelerating material which is undergoing mass—energy fluctuations, [1]-[3]. Mach’s principle is ... The Mach Effect Thruster (MET) is a propellant—less space drive which uses Mach’s principle to produce thrust in an accelerating material which is undergoing mass—energy fluctuations, [1]-[3]. Mach’s principle is a statement that the inertia of a body is the result of the gravitational interaction of the body with the rest of the mass-energy in the universe. The MET device uses electric power of 100 - 200 Watts to operate. The thrust produced by these devices, at the present time, are small on the order of a few micro-Newtons. We give a physical description of the MET device and apparatus for measuring thrusts. Next we explain the basic theory behind the device which involves gravitation and advanced waves to incorporate instantaneous action at a distance. The advanced wave concept is a means to conserve momentum of the system with the universe. There is no momentun violation in this theory. We briefly review absorber theory by summarizing Dirac, Wheeler-Feynman and Hoyle-Narlikar (HN). We show how Woodward’s mass fluctuation formula can be derived from first principles using the HN-theory which is a fully Machian version of Einstein’s relativity. HN-theory reduces to Einstein’s field equations in the limit of smooth fluid distribution of matter and a simple coordinate transformation. 展开更多
关键词 MACH effect Drive Transient Mass Fluctuations Weak Field Limit GRAVITATION Modified (PPN) Parameterized Post NEWTONIAN Approximation Linearized EINSTEIN Equations Gravitoelectromagnetism
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Signal transducer and activator of transcription 3 promotes the Warburg effect possibly by inducing pyruvate kinase M2 phosphorylation in liver precancerous lesions 被引量:8
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作者 Yang-Hui Bi Wen-Qi Han +4 位作者 Ruo-Fei Li Yun-Jiao Wang Zun-Shu Du Xue-Jiang Wang Ying Jiang 《World Journal of Gastroenterology》 SCIE CAS 2019年第16期1936-1949,共14页
BACKGROUND Study shows that signal transducer and activator of transcription 3(STAT3) can increase the Warburg effect by stimulating hexokinase 2 in breast cancer and upregulate lactate dehydrogenase A and pyruvate de... BACKGROUND Study shows that signal transducer and activator of transcription 3(STAT3) can increase the Warburg effect by stimulating hexokinase 2 in breast cancer and upregulate lactate dehydrogenase A and pyruvate dehydrogenase kinase 1 in myeloma. STAT3 and pyruvate kinase M2(PKM2) can also be activated and enhance the Warburg effect in hepatocellular carcinoma. Precancerous lesions are critical to human and rodent hepatocarcinogenesis. However, the underlying molecular mechanism for the development of liver precancerous lesions remains unknown. We hypothesized that STAT3 promotes the Warburg effect possibly by upregulating p-PKM2 in liver precancerous lesions in rats.AIM To investigate the mechanism of the Warburg effect in liver precancerous lesions in rats.METHODS A model of liver precancerous lesions was established by a modified Solt-Farber method. The liver pathological changes were observed by HE staining and immunohistochemistry. The transformation of WB-F344 cells induced with Nmethyl-N'-nitro-N-nitrosoguanidine and hydrogen peroxide was evaluated by the soft agar assay and aneuploidy. The levels of glucose and lactate in the tissue and culture medium were detected with a spectrophotometer. The protein levels of glutathione S-transferase-π, proliferating cell nuclear antigen(PCNA), STAT3,and PKM2 were examined by Western blot and immunofluorescence.RESULTS We found that the Warburg effect was increased in liver precancerous lesions in rats. PKM2 and p-STAT3 were upregulated in activated oval cells in liverprecancerous lesions in rats. The Warburg effect, p-PKM2, and p-STAT3 expression were also increased in transformed WB-F344 cells. STAT3 activation promoted the clonal formation rate, aneuploidy, alpha-fetoprotein expression,PCNA expression, G1/S phase transition, the Warburg effect, PKM2 phosphorylation, and nuclear translocation in transformed WB-F344 cells.Moreover, the Warburg effect was inhibited by stattic, a specific inhibitor of STAT3, and further reduced in transformed WB-F344 cells after the intervention for PKM2.CONCLUSION The Warburg effect is initiated in liver precancerous lesions in rats. STAT3 activation promotes the Warburg effect by enhancing the phosphorylation of PKM2 in transformed WB-F344 cells. 展开更多
关键词 WARBURG effect Hepatic PROGENITOR cell Signal transducer and activator of transcription 3 PYRUVATE kinase M2 LIVER PRECANCEROUS lesion
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Cardioprotective effects of Salvia miltiorrhiza Bunge and Lignum dalbergiae odoriferae on rat myocardial ischemia/reperfusion injury
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《中国药理学通报》 CAS CSCD 北大核心 2015年第B11期168-169,共2页
Aim Salvia miltiorrhiza Bunge (SM) and lignum dalbergiae odoriferae (DO) are both traditional Chi- nese medicine that have cardioprotective effects. Here, we further examined the combined effects of SM and DO on r... Aim Salvia miltiorrhiza Bunge (SM) and lignum dalbergiae odoriferae (DO) are both traditional Chi- nese medicine that have cardioprotective effects. Here, we further examined the combined effects of SM and DO on rat myocardial ischemia/reperfusion injury. The possible mechanism of SM and DO also were elucidated. Methods DO was divided into aqueous extract of lignum dalbergiae odoriferae (DOW) and lignum dalbergiae odoriferae oil (DOO). Sprague-Dawley rats were randomized to seven groups: sham group, model group, treatment groups inclu- ding SM (10 g · kg^-1), DOW (5 g · kg^-1), DOO (0.5 ml · kg^-1), SM + DOW (10 g · kg^-1 + 5 g · kg^-1), SM + DOO ( 10 g · kg^-1 + 0. 5 ml · kg^-1). Rats were pretreated with homologous drug for 7 days and then subjec- ted to 30 rain of ischemia followed by 180 rain of reperfusion. Electrocardiogram (ECG) and heart rate were moni- tored and recorded continuously. At the end of reperfusion, blood samples were collected to determine the serum levels of creatine kinase-MB (CK-MB) and lactate dehydrogenase (LDH). Hearts were harvested to assess heart- body rate, infarct size and histopathological changes as well. Maximum and minimum effective points were deter- mined by measuring indicators associate with myocardial injury at different time-points of reperfusion (Smin, 15min, 30min, 45rain, 60min, 120min, 180min). The potential therapeutic mechanism of SM and SM + DOO were carried out by detecting superoxide dismutase (SOD), malondialdehyde (MDA), tumor necrosis factor-alpha (TNF-alpha) and interleukin 6 (IL-6). Results The results showed SM and DO can ameliorate cardiac function respectively, and this cardioprotective effect was further strengthened by their combinations. Among all the combi- nations, SM + DOO showed predominant potential to improve ECG and heart rate, reduce heart-body rate (28.5% + 1.4% , P 〈 0.01 vs model) and myocardial infarct size ( 20.96% + 1.61% , P 〈 0.01 vs model, P 〈 0.05 vs SM) , attenuate histopathological damage, decrease the levels of CK-MB and LDH (P 〈 0.01 vs model, P 〈 0.05 vs SM). The maximum effective points of SM and SM + DOO were 15min and 30rain respectively, and the minimum effective points of them were 180rain. In reducing serum level of MDA, TNF-alpha, IL-6 and increasing SOD activ- ity, SM + DOO was similar to SM. Conclusion The results of this study indicated that SM + DOO have combined effects that are highly effective than single pretreatment against myocardial ischemie reperfusion injury in rats. The possible mechanism of SM and DO were likely through its anti-oxidant and anti-inflammatory properties, and thus may be an effective and promising medicine for both prophylaxis and treatment of ischemic heart disease. 展开更多
关键词 Keywords:myocardialischemia/reperfusioninjury SalviamiltiorrhizaBunge Lignumdalbergiaeodoriferae the MYOCARDIAL ISCHEMIA/REPERFUSION INJURY SALVIA miltiorrhiza BUNGE Lignum dalbergiae odoriferae themaximum and minimum effective points ANTI-OXIDANT anti-inflammatory
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Efficacy and side effects of praziquantel in the treatment of Schistosomiasis mansoni in schoolchildren in Shesha Kekele Elementary School,Wondo Genet,Southern Ethiopia 被引量:3
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作者 Berhanu Erko Abraham Degarege +2 位作者 Konjit Tadesse Asnake Mathiwos Mengistu Legesse 《Asian Pacific Journal of Tropical Biomedicine》 SCIE CAS 2012年第3期235-239,共5页
Objective:To evaluate the efficacy and side effects of praziquantel(PZQ) in the treatment of schistosomiasis in Ethiopia.Methods:In a cross-sectional study,stool specimens were collected from randomly selected 299 sch... Objective:To evaluate the efficacy and side effects of praziquantel(PZQ) in the treatment of schistosomiasis in Ethiopia.Methods:In a cross-sectional study,stool specimens were collected from randomly selected 299 school children in Shesha Kekele Elementary School,Wondo Genet, Southern Ethiopia,in April 2010.Stool specimens were examined using a single Kato-Katz thick smear for Schistosoma mansoni(5.mansoni) ova.Children who were found positive for S.mansoni were treated with a single oral dose of PZQ at 40 mg/kg bw and interviewed for treatment-related symptoms 24 hours after drug administration.Four weeks post-treatment,stool specimens were collected from the same children and examined following the same procedure as in the pretreatment.Drug efficacy was determined based on cure and egg reduction rates.Results:Pretreatment prevalence of S.mansoni infection was 74.9%with geometric mean egg count of 268. The evaluated generic PZQ produced an overall cure rate of 73.6%(P<0.000 1,OR:8.33,CI:5.3-13.1) and egg reduction rate of 68.2%(P=0.03,F=0.64).The cure rate showed significant association with age(x^2=H,P=0.004),the highest rate being observed in the 15-22 age group.83%of S. mansoni infected children showed various treatment-related symptoms,the most frerjiient being headache,nausea,and abdominal pain.These symptoms were associated with age(P<0.001) and pre-treatment intensity of infection(P<0.05).Conclusions:The present observations revealed relatively lower cure and egg reduction rates of the PZQ evaluated as compared to previous reports for other PZQ brands in Ethiopia.Hence,in depth studies are recommended to clarify whether the present relatively lower cure rate is the actual cure rate of the praziquantel evaluated,treatment failure,or reduced susceptibility of the parasite.Treatment-related side effects observed were transient and tolerable. 展开更多
关键词 EFFICACY PRAZIQUANTEL SCHISTOSOMA MANSONI Ethiopia Schistosomiasis Thick smear Prevalence Infection Susceptibility Parasite SCHOOLCHILDREN Side effect Drug EFFICACY Egg reduction
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双管式挫屈束制(屈曲约束)支撑之耐震行为与应用 被引量:102
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作者 蔡克铨 黄彦智 翁崇兴 《建筑钢结构进展》 2005年第3期1-8,共8页
挫屈束制(屈曲约束)支撑一般是由十字型或一字型钢板构成之核心单元加上钢管混凝土构成之束制(约束)单元所组成。由于单核心断面之挫屈束制支撑在与构架接合时每一端需使用八片续接板及两套的螺栓,造成接合部分较长且易发生挫屈(屈曲),... 挫屈束制(屈曲约束)支撑一般是由十字型或一字型钢板构成之核心单元加上钢管混凝土构成之束制(约束)单元所组成。由于单核心断面之挫屈束制支撑在与构架接合时每一端需使用八片续接板及两套的螺栓,造成接合部分较长且易发生挫屈(屈曲),为了改善此种挫屈束制支撑与接合,相关研究已发展出以双T型核心配双钢管或双钢板核心配双钢管而组成之双钢管型挫屈束制支撑构件,并已成功地在台大完成一系列之试验,本研究进一步针对大尺寸之单层挫屈束制支撑构架进行试验。研究目的包括:(1)探讨支撑具不同核心长度比例构架之试验与解析行为;(2)研究挫屈束制支撑核心应变与楼层侧位移角之关系;(3)提供含挫屈束制支撑构架之分析与设计建议。由三组V型双钢板双钢管挫屈束制支撑构架之试验显示,支撑核心之极限应变可利用楼层的最大侧位移角需求,以简单的几何关系及支撑核心长度与工作点间长度之比值计算而得,试验结果亦显示,在构架产生最大侧位移角时支撑之核心拉应变会大于相邻支撑之核心压应变,显示两相邻支撑之轴拉力与轴压力在试体中有互相平衡之趋势,而不会发生最大轴压力显著大于最大轴拉力的现象。 展开更多
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