The Qilian Mountain permafrost area located in the northern of Qinghai-Tibet Plateau is a favorable place for natural gas hydrate formation and enrichment,due to its well-developed fractures and abundant gas sources.U...The Qilian Mountain permafrost area located in the northern of Qinghai-Tibet Plateau is a favorable place for natural gas hydrate formation and enrichment,due to its well-developed fractures and abundant gas sources.Understanding the formation and distribution of multi-component gas hydrates in fractures is crucial in accurately evaluating the hydrate reservoir resources in this area.The hydrate formation experiments were carried out using the core samples drilled from hydrate-bearing sediments in Qilian Mountain permafrost area and the multi-component gas with similar composition to natural gas hydrates in Qilian Mountain permafrost area.The formation and distribution characteristics of multi-component gas hydrates in core samples were observed in situ by X-ray Computed Tomography(X-CT)under high pressure and low temperature conditions.Results show that hydrates are mainly formed and distributed in the fractures with good connectivity.The ratios of volume of hydrates formed in fractures to the volume of fractures are about 96.8%and 60.67%in two different core samples.This indicates that the fracture surface may act as a favorable reaction site for hydrate formation in core samples.Based on the field geological data and the experimental results,it is preliminarily estimated that the inventory of methane stored in the fractured gas hydrate in Qilian Mountain permafrost area is about 8.67×1013 m3,with a resource abundance of 8.67×108 m3/km2.This study demonstrates the great resource potential of fractured gas hydrate and also provides a new way to further understand the prospect of natural gas hydrate and other oil and gas resources in Qilian Mountain permafrost area.展开更多
This paper examines the effect of supply-side structural reforms on China's potential economic growth rate in the coming decade according to the data the authors have gathered. Under the rapid growth scenario with th...This paper examines the effect of supply-side structural reforms on China's potential economic growth rate in the coming decade according to the data the authors have gathered. Under the rapid growth scenario with the implementation of supply-side structural reforms, China's potential economic growth rate will reach an average of 6.5% and 5.8% respectively in the 13th Five-year Plan (2016-2020) and 14th Five-year Plan (2021-2025) periods. These rates are 0.2 and 0.3 percentage points higher, respectively, than that under the baseline scenario with the inertia of historic trends. In implementing supply-side structural reforms, China must transform governmental functions, break monopolies, create a comprehensive competitive market environment, foster the creation of pro-innovation mechanisms, refocus on quality and efficiency, and raise capital utilization and labor productivity.展开更多
Different from other methodologies for the forecasting of China's economic growth rate, this paper forecast of future potential growth rates from the end of China's demographic dividends, and then identified it as a...Different from other methodologies for the forecasting of China's economic growth rate, this paper forecast of future potential growth rates from the end of China's demographic dividends, and then identified it as a growth target. Official promulgation of non-binding targets will guide social expectation, assist in government policy-making, boost confidence in consumers, and provide guidance for producers and investors. Based on our estimation results, we suggest that during the 13th Five-Year Plan period, a GDP growth target between 6. 5% and 7% would be appropriate.展开更多
China has entered a crucial period of further growth and restructuring that will last until 2025. Based on a review of the major factors affecting China's potential economic growth, this paper has created an integrat...China has entered a crucial period of further growth and restructuring that will last until 2025. Based on a review of the major factors affecting China's potential economic growth, this paper has created an integrated economic system model consisting of system dynamics, econometrics, and input-output for the forecast of China's economic size and structure by 2025. Analysis shows that prior to 2025, China will be able to maintain a potential annual economic growth rate of 5.7%-7.2%. Faced with an international environment of a possible slowdown of advanced economies and diminishing demographic dividends, China needs to further expedite its urbanization process, enhance R&D and education spending, increase total factor productivity (TFP), vigorously develop the tertiary sector, and expand consumption in order to achieve the optimistically estimated growth of 6.6%-7.4% during the period of 2015-2025. Economic growth should be accompanied by the upgrade of industry structure and improvement of investment and consumption structures.展开更多
Synaptic dysfunction is an important pathological hallmark and cause of Alzheimer's disease(AD).High-frequency stimulation(HFS)-induced long-term potentiation(LTP)has been widely used to study synaptic plasticity,...Synaptic dysfunction is an important pathological hallmark and cause of Alzheimer's disease(AD).High-frequency stimulation(HFS)-induced long-term potentiation(LTP)has been widely used to study synaptic plasticity,with impaired LTP found to be associated with AD.However,the exact molecular mechanism underlying synaptic plasticity has yet to be completely elucidated.Whether genes regulating synaptic plasticity are altered in AD and contribute to disease onset also remains unclear.Herein,we induced LTP in the hippocampal CA1 region of wildtype(WT)and AD model mice by administering HFS to the CA3 region and then studied transcriptome changes in the CA1 region.We identified 89 genes that may participate in normal synaptic plasticity by screening HFS-induced differentially expressed genes(DEGs)in mice with normal LTP,and 43 genes that may contribute to synaptic dysfunction in AD by comparing HFS-induced DEGs in mice with normal LTP and AD mice with impaired LTP.We further refined the 43 genes down to 14 by screening for genes with altered expression in pathological-stage AD mice without HFS induction.Among them,we found that the expression of Pygm,which catabolizes glycogen,was also decreased in AD patients.We further demonstrated that down-regulation of PYGM in neurons impaired synaptic plasticity and cognition in WT mice,while its overexpression attenuated synaptic dysfunction and cognitive deficits in AD mice.Moreover,we showed that PYGM directly regulated energy generation in neurons.Our study not only indicates that PYGM-mediated energy production in neurons plays an important role in synaptic function,but also provides a novel LTP-based strategy to systematically identify genes regulating synaptic plasticity under physiological and pathological conditions.展开更多
Objective It is known that free radicals are involved in neurodegeneration and cognitive dysfunction, as seen in Alzheimer's disease (AD) and aging. The present study examines the protective effects of aniracetam a...Objective It is known that free radicals are involved in neurodegeneration and cognitive dysfunction, as seen in Alzheimer's disease (AD) and aging. The present study examines the protective effects of aniracetam against H2O2- induced toxicity to neuron viability, mitochondria potential and hippocampal long-term potentiation (LTP). Methods Tetrazolium salt 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide (MTT) was used to detect neuronal viability. MitoTracker Red (CMX Ros), a fluorescent stain for mitochondria, was used to measure mitochondria potential. Electrophysiological technique was carried out to record hippocampual LTE Results H2O2 exposure impaired the viability of neurons, reduced mitochondria potential, and decreased LTP in the CA region of hippocampus. These deficient effects were significantly rescued by pre-treatment with aniracetam (10 ~100μmol/L). Conclusion These results indicate that aniracetam has a strong neuroprotective effect against H2O2-induced toxicity, which could partly explain the mechanism of its clinical application in neurodegenerative diseases.展开更多
BACKGROUND: Pattern- visual evoked potential (PVEP) can reflect the functional status of retinal ganglial cells (RGC) and visual cortex, and is an objective examination for visual pathway function. It is a unique...BACKGROUND: Pattern- visual evoked potential (PVEP) can reflect the functional status of retinal ganglial cells (RGC) and visual cortex, and is an objective examination for visual pathway function. It is a unique method for objectively examining the optic nerve function of optic ganglion cells. OBJECTIVE: To observe the effects of nerve growth factor (NGF) on PVEF in the treatment of optic nerve contusion, evaluate the clinical efficacy of NGF, and make an efficacy comparison with vitamin B12. DESIGN: A randomly grouping, controlled observation. SETTING: Department of Ophthalmology, Tangshan Gongren Hospital Affiliated to Hebei Medical University. PARTICIPANTS: Forty patients with optic nerve contusion caused by eye trauma, who received the treatment in the Tangshan Worker Hospital Affiliated to Hebei Medical University between January 2006 and June 2007, were recruited in this study. The involved 40 patients, including 34 males and 6 females, were aged 14-59 years. They were confirmed to have optic nerve contusion by ophthalmologic consultation combined with history of disease and orbital CT examination. Informed consents of treatments and detected items were obtained from all the patients. The patients were randomly divided into 2 groups with 20 in each: NGF group and vitamin B12 group. METHODS: Conservative treatment was used in the two groups. In addition, patients in the NGF group were intramuscularly injected with NGF solution 18 μg /time, once a day. Those in the vitamin B12 group were injected by the same method with common vitamin B12 of 500 μg combined with vitamin B1 of 100 mg, once a day. MAIN OUTCOME MEASURES: PVEP examination was conducted in all the patients before, one and two weeks after treatment, and latency and amplitude at P100 were detected. RESULTS: Forty patients with optic nerve contusion participated in the final analysis. Before treatment, significant differences in the latency and amplitude at P100 were not found in patients between two groups (P 〉 0.05). For each patient in the NGF group, the latency of PVEP at P100 was significantly shortened, and the amplitude was significantly increased one and two weeks after treatment as compared with vitamin B12 group(t =2.06-2.34, P 〈 0.05). CONCLUSION: NGF treatment can obviously improve the visual function of patients with optic nerve contusion. The curative effect of NGF is superior to vitamin B12.展开更多
BACKGROUND: Long-term potentiation of cornu dorsale medullae spinalis field potential in adult rats has already been reported; however, there is lack of correlated researches on naenonate, infant and adult rats which...BACKGROUND: Long-term potentiation of cornu dorsale medullae spinalis field potential in adult rats has already been reported; however, there is lack of correlated researches on naenonate, infant and adult rats which have different responses to pain conduction information.OBJECTIVE: To observe the various effects of electric stimulation at sciatic nerve on long-term potentiation of evoked field potential at superficial layer of cornu dorsale medullae spinalis of rats at various developmental phases and analyze manifestations of pain conduction information at superficial layers ( Ⅰ - Ⅱ)of cornu dorsale medullae spinalis in immature rats.DESIGN: Grouping controlled study.SETTING: Department of Physiology, Medical College of Wuhan University.MATERIALS: The experiment was carried out in the Laboratory of Physiology (provincial laboratory),Medical College of Wuhan University from March 2006 to May 2007. A total of 27 healthy male Sprague-Dawley (SD) rats, 17- 90 days old, SPF grade, weighing 41 -200 g, were provided by Experimental Animal Center, Medical College of Wuhan University.METHODS: Based on their birthdays, rats were divided into naenonate group (17 - 20 days old, weighing 41-52 g, n =10), infant group (35 - 50 days old, weighing 87 - 125 g, n =10) and adult group (60 - 90 days old, weighing 180 -200 g, n =7). Left sciatic nerve was separated and stimulated with single square wave (15 V, 0.5 ms). Meanwhile, evoked field potential was recorded at superficial layers of lateral T13 - L1 cornu dorsale medullae spinalis and then stimulated with high-frequent and high-intensive tetanizing current (30 -40 V, 0.5 ms, 100 Hz, 1s per bundle, 10s in bundle interval) four times. After the operation, onset of long-term potentiation was observed; meanwhile, amplitude changes and latency of field potential were analyzed.MAIN OUTCOME MEASURES: Amplitude and latency changes of field potential at superficial layers of cornu dorsale medullae spinalis of rats in the three groups.RESULTS: A total of 27 accepted rats were involved in the final analysis. ① Amplitude changes: Electric stimulation at sciatic nerve with high-frequent and high-intensive tetanizing current could induce evoked field potential at superficial layers (Ⅰ-Ⅱ ) of cornu dorsale medullae spinalis in the three groups.Long-term potentiation in the naenonate group manifested that amplitude of A-kind never fiber was raised and there was significant difference (P〈0.05). In addition, average amplitude was increased and there was obviously significant difference (P〈0.01). Long-term potentiation in the infant group manifested that amplitude of C-kind never fiber was raised and there was significant difference (P〈0.01); while, long-term potentiation in the adult group manifested that amplitude of C-kind never fiber was raised and there was significant difference (P〈0.01). Otherwise, latencies in the three groups were all shortened. ② Latency changes: Average latency of A-kind nerve fiber in the naenonate group was shortened and there was significant difference (P〈0.01); in addition, evoked potential of C-kind nerve fiber was low and latency was immovable. There was no significant difference before and after high-frequent and high-intensive electric stimulation (P〉0.05). Average latency of C-kind nerve fiber in the infant group was shortened and there was significant difference (P〈0.01); in addition, evoked potential of A-kind nerve fiber was stable and latency was immovable. There was no significant difference before and after high-frequent and high-intensive electric stimulation (P〉0.05). Average latency of C-kind nerve fiber in the adult group was shortened and there was significant difference (P〈0.01); in addition, evoked potential of A-kind nerve fiber was stable and latency was immovable. There was no significant difference before and after high-frequent and high-intensive electric stimulation.CONCLUSION: Evoked field potential at superficial layer of comu dorsale medullae spinalis can be recorded through electric stimulation at sciatic nerve. Single stimulation and tetanizing electric stimulation can cause different characteristics of evoked field potential in rats at various developmental phases.Superficial layer of cornu dorsale medullae spinalis of naenonate rats is mainly caused by A-kind nerve fiber which participants in pain conduction and formation of pain sensitivity; however, that of infant and adult rats mainly depends on C-kind nerve fiber.展开更多
Due to diminishing demographic dividend characterized by a falling workingage population and rising dependency ratio, China's long-term potential growth rates will keep declining, likely to be a mere 6.6% during t...Due to diminishing demographic dividend characterized by a falling workingage population and rising dependency ratio, China's long-term potential growth rates will keep declining, likely to be a mere 6.6% during the 13 th Five-Year Plan period(2016-2020). China's economic growth sustainability hinges upon its transition from the previous dependence on demographic dividend to the future reform dividend. In the growth accounting equation, we have simulated various reform initiatives and arrived at the following findings. First, although both the labor participation rate and TFP can increase China's potential growth rate, the former will only achieve a short-term growth effect, which will diminish in the long run. By contrast, the growth effect of TFP demonstrates the tendency of continuous increase. This further indicates that China's economic growth will increasingly rely on TFP improvement instead of traditional factor input. Second, different from the diminishing growth effect of enrolment rate, training may play a pivotal role in human capital development to significantly enhance potential growth rates. Third, if all reform initiatives can achieve their expected effects, integrated reform dividends may reach one or two percentage points of China's potential growth rate.展开更多
In this paper, we study the following Schrödinger-Kirchhoff equation where V(x) ≥ 0 and vanishes on an open set of R<sup>2</sup> and f has critical exponential growth. By using a version of Trudinger...In this paper, we study the following Schrödinger-Kirchhoff equation where V(x) ≥ 0 and vanishes on an open set of R<sup>2</sup> and f has critical exponential growth. By using a version of Trudinger-Moser inequality and variational methods, we obtain the existence of ground state solutions for this problem.展开更多
In this paper a general formula for plastic potential including isotropic ductile damage has been present ed on the basis of the thermodynamics for irreversible process and internal variable the- ory.With this formula...In this paper a general formula for plastic potential including isotropic ductile damage has been present ed on the basis of the thermodynamics for irreversible process and internal variable the- ory.With this formula the mass conservation law is satisfied and it also contains a series of unknow coefficients which are the function of macro equivalent stress and the average micro equivalent stress and an unknown function which is the function of two generalized forces. The approximate yield surface equation for isotropically damaged materials is developed.Using this equation the void growth rate is calculated for nonlinear material containing voids.The present re- sults are in good agreement with the numerical results given by the cell model.展开更多
In this test,we used phytoplankton assay procedure to carry out determinations of phytoplankton growth potential and limiting nutrients in Gengjing reservoir.The test results revealed that,in Gengying reservoir waters...In this test,we used phytoplankton assay procedure to carry out determinations of phytoplankton growth potential and limiting nutrients in Gengjing reservoir.The test results revealed that,in Gengying reservoir waters,the phytoplankton growth potential of the autoclaved-filtrates and the filtrates are from 0.2 to 2.1 mg/L and from 0 to 1.0 mg/L,and in waterway waters,those of the autoclaved-filtrates and the filtrates are from 0 to 3.3 mg/L and from 0 to 2.2 mg/L.The phytoplankton growth potential of the autoclaved filtrates is approximately two times higher than those of the filtrates.When phosphorus is adjusted beyond 0.5 mg/L,the growth of the phytoplankton is especially very high.Moreover,the limiting concentration of the phosphorus for the growth of phytoplankton is in the range of 0.025 to 0.05 mg/L;the phytoplankton growth potential of the grit chamber sediment samples is higher than those of the waterway sediment.展开更多
To study the osteogenic potential of cultured bone marrow stromal cells transfected with transforming growth factor β 1 gene in vitro , cultured BMSCs were transfected with the complexes of pcDNA 3 TGF β ...To study the osteogenic potential of cultured bone marrow stromal cells transfected with transforming growth factor β 1 gene in vitro , cultured BMSCs were transfected with the complexes of pcDNA 3 TGF β 1 and Lipofectamine Reagent in vitro . The cell proliferation was detected by MTT method and the morphological features of transfected BMSCs was observed. ALP stains and PNP method were used to measure ALP activity. In addition, the collagen type Ⅰ propeptides and mineralized matrixes were examined by immunohistochemical staining and tetracycline fluorescence labeling respectively. The morphological and biological characters of the transfected BMSCs were similar to those of osteoblasts and the cell proliferation was promoted. The cell layer displayed strong positive reaction for ALP stains and immunohistochemical staining. ALP activity and collagen type Ⅰ expression increased remarkably after transfection. Mineralized matrixes formed earlier and more in transfected BMSCs as compared with control group. It is concluded that transfecting with TGF β 1 gene could promote the osteogenic potential of cultured BMSCs.展开更多
Plants which contain unisexual flowers are subjected to genetic degradation and yield capacity reduction due to the easily cross-pollination.Sponge gourd,one of species of the Cucurbitaceae which is predominantly cros...Plants which contain unisexual flowers are subjected to genetic degradation and yield capacity reduction due to the easily cross-pollination.Sponge gourd,one of species of the Cucurbitaceae which is predominantly cross-pollinating,is cultivated to widely use as vegetable in Vietnamese daily meals.The aim of this experiment was to evaluate the growth potential and fruit quality including fruit aroma of sponge gourd inbred lines.Pure line selection has been performed using self-pollinated method,so that sponge gourd lines would be recovered with high yielding and aroma and thereby recommended for further crop system in Thua Thien Hue province,Central Vietnam.The experiment was conducted in a randomized complete block design(RCBD)with three replications during the winter-spring season in 2017.Agronomical data were observed and analyzed on seven inbred lines(1-MN1,1-MN2,5-MN1,7-MN1,13-MN2,15-MN1 and 15-MN2)derived from B29 accession(GBVN006904).The results indicated that inbred lines 13-MN2,1-MN2 and 15-MN1 attained more highly fruit weight and yield compared to the others.Four inbred lines consisting of 5-MN1,7-MN1,15-MN1 and 15-MN2 still retained the light aroma after boiling.The inbred lines 1-MN2,7-MN1,13-MN2 and 15-MN1 are considered for appropriately using in breeding program of new luffa.展开更多
Agricultural structure adjustment has always been the important factors influencing Xinjiang agricultural internal income growth.On the basis of the planting scale,productivity and price in 2010,the paper measured the...Agricultural structure adjustment has always been the important factors influencing Xinjiang agricultural internal income growth.On the basis of the planting scale,productivity and price in 2010,the paper measured the contributions made by agricultural structure adjustment to Xinjiang agricultural internal income growth through structural optimization.Linear programming model was established by Lingo software,to optimize the structure of planting,horticulture,animal husbandry in Xinjiang and analyze the internal agricultural income growth potential.After structure optimization,Xinjiang agricultural production value will reach 1231.44×108yuan and the farmers'income of production and management will reach 9851yuan.The greatest potential for Xinjiang agricultural internal income growth was husbandry accounting for 41.33% of the total production value.The next one was horticulture,whose share of the total production value has raised to 17.43% from 10%.Fruit industry and animal husbandry will become the pillars of future income growth.There are still some income growth spaces in Xinjiang internal agriculture though the agricultural structure adjustment.The agricultural production value will increase by 44.32%and farmers'production and management income will increase by 68.83%.That will be one of the most important ways to tap the future potential of agriculture internal income growth.展开更多
Objective To explore the effects of exposure to aluminum (AI) on long-term potentiation (LTP) and AMPA receptor subunits in rats in vivo. Methods Different dosages of aluminum-maltolate complex [Al(mal)3] were g...Objective To explore the effects of exposure to aluminum (AI) on long-term potentiation (LTP) and AMPA receptor subunits in rats in vivo. Methods Different dosages of aluminum-maltolate complex [Al(mal)3] were given to rats via acute intracerebroventricular (i.c.v.) injection and subchronic intraperitoneal (i.p.) injection. Following AI exposure, the hippocampal LTP were recorded by field potentiation technique in vivo and the expression of AMPAR subunit proteins (GluR1 and GluR2) in both total and membrane-enriched extracts from the CA1 area of rat hippocampus were detected by Western blot assay. Results Acute AI treatment produced dose-dependent suppression of LTP in the rat hippocampus and dose-dependent decreases of GluRz and GluR2 in membrane extracts; however, no similar changes were found in the total cell extracts, which suggests decreased trafficking of AMPA receptor subunits from intracellular pools to synaptic sites in the hippocampus. The dose-dependent suppressive effects on LTP and the expression of AMPA receptor subunits both in the membrane and in total extracts were found after subchronic AI treatment, indicating a decrease in AMPA receptor subunit trafficking from intracellular pools to synaptic sites and an additional reduction in the expression of the subunits. Conclusion Al(mal)3 obviously and dose-dependently suppressed LTP in the rat hippocampal CA1 region in vivo, and this suppression may be related to both trafficking and decreases in the expression of AMPA receptor subunit proteins. However, the mechanisms underlying these observations need further investigation.展开更多
The long-term enhancement in glutamate receptor mediated excitatory responses has been observed in stroke model. This pathological form of plasticity, termed post-ischemic long-term potentiation (i-LTP), points to f...The long-term enhancement in glutamate receptor mediated excitatory responses has been observed in stroke model. This pathological form of plasticity, termed post-ischemic long-term potentiation (i-LTP), points to functional reorganization after stroke. Little is known, however, about whether and how this i-LTP would affect subsequent induction of synaptic plasticity. Here, we first directly confirmed that i-LTP was induced in the endothelin-l-induced ischemia model as in other in vitro models. We also demonstrated increased expression of NR2B, CaMKII and p-CaMKII, which are reminiscent of i-LTP. We further induced LTP of field excitatory post- synaptic potentials (fEPSPs) on CA1 hippocampal neurons in peri-infarct regions of the endothelin-l-induced mini-stroke model. We found that LTP of fEPSPs, induced by high-frequency stimulation, displayed a progressive impairment at 12 and 24 hours after ischemia. Moreover, using in vivo multi-channel recording, we found that the local field potential, which represents electrical property of cell ensembles in more restricted regions, was also dam- pened at these two time points. These results suggest that i-LTP elevates the induction threshold of subsequent synap- tic plasticity. Our data helps to deepen the knowledge of meta-synaptic regulation of plasticity after focal ischemia.展开更多
Objective To explore the role of RAS/PI3K pathway in the impairment of long-term potentiation (LTP) induced by acute aluminum (AI) treatment in rats in vivo. Methods First, different dosages of aluminum-maltolate ...Objective To explore the role of RAS/PI3K pathway in the impairment of long-term potentiation (LTP) induced by acute aluminum (AI) treatment in rats in vivo. Methods First, different dosages of aluminum-maltolate complex [Al(mal)3] were given to rats via acute intracerebroventricular (i.c.v.) injection. Following AI exposure, the RAS activity of rat hippocampus were detected by ELISA assay after the hippocampal LTP recording by field potentiation technique in vivo. Second, the antagonism on the aluminum-induced suppression of hippocampal LTP was observed after the treatment of the RAS activator epidermal growth factor (EGF). Finally, the antagonism on the downstream molecules (PKB activity and the phosphorylation of GluR1 $831 and $845) were tested by ELISA and West-blot assays at the same time. Results With the increasing aluminum dosage, a gradually decreasing in RAS activity of the rat hippocampus was produced after a gradually suppressing on LTP. The aluminum-induced early suppression of hippocampal LTP was antagonized by the RAS activator epidermal growth factor (EGF). And the EGF treatment produced changes similar to those observed for LTP between the groups on PKB activity as well as the phosphorylation of GluR1 S831 and s845. Conclusion The RAS-PI3K/PKB-GluR1 S831 and S845 signal transduction pathway may be involved in the inhibition of hippocampal LTP by aluminum exposure in rats. However, the mechanisms underlying this observation need further investigation.展开更多
Objective To explore the changes in spatial learning performance and long-term potentiation (LTP) which is recognized as a component of the cellular basis of learning and memory in normal and lead-exposed rats after...Objective To explore the changes in spatial learning performance and long-term potentiation (LTP) which is recognized as a component of the cellular basis of learning and memory in normal and lead-exposed rats after administration of melatonin (MT) for two months. Methods Experiment was performed in adult male Wistar rats (12 controls, 12 exposed to melatonin treatment, 10 exposed to lead and 10 exposed to lead and melatonin treatment). The lead-exposed rats received 0.2% lead acetate solution from their birth day while the control rats drank tap water. Melatonin (3 mg/kg) or vehicle was administered to the control and lead-exposed rats from the time of their weaning by gastric gavage each day for 60 days, depending on their groups. At the age of 81-90 days, all the animals were subjected to Morris water maze test and then used for extracellular recording of LTP in the dentate gyrus (DG) area of the hippocampus in vivo. Results Low dose of melatonin given from weaning for two months impaired LTP in the DG area of hippocampus and induced learning and memory deficit in the control rats. When melatonin was administered over a prolonged period to the lead-exposed rats, it exacerbated LTP impairment, learning and memory deficit induced by lead. Conclusion Melatonin is not suitable for normal and lead-exposed children.展开更多
基金the financial support of the National Natural Science Foundation of China(42176212,41976074 and 41302034)the Marine S&T Fund of Shandong Province for Laoshan Laboratory(2021QNLM020002)the Marine Geological Survey Program(DD20221704)。
文摘The Qilian Mountain permafrost area located in the northern of Qinghai-Tibet Plateau is a favorable place for natural gas hydrate formation and enrichment,due to its well-developed fractures and abundant gas sources.Understanding the formation and distribution of multi-component gas hydrates in fractures is crucial in accurately evaluating the hydrate reservoir resources in this area.The hydrate formation experiments were carried out using the core samples drilled from hydrate-bearing sediments in Qilian Mountain permafrost area and the multi-component gas with similar composition to natural gas hydrates in Qilian Mountain permafrost area.The formation and distribution characteristics of multi-component gas hydrates in core samples were observed in situ by X-ray Computed Tomography(X-CT)under high pressure and low temperature conditions.Results show that hydrates are mainly formed and distributed in the fractures with good connectivity.The ratios of volume of hydrates formed in fractures to the volume of fractures are about 96.8%and 60.67%in two different core samples.This indicates that the fracture surface may act as a favorable reaction site for hydrate formation in core samples.Based on the field geological data and the experimental results,it is preliminarily estimated that the inventory of methane stored in the fractured gas hydrate in Qilian Mountain permafrost area is about 8.67×1013 m3,with a resource abundance of 8.67×108 m3/km2.This study demonstrates the great resource potential of fractured gas hydrate and also provides a new way to further understand the prospect of natural gas hydrate and other oil and gas resources in Qilian Mountain permafrost area.
文摘This paper examines the effect of supply-side structural reforms on China's potential economic growth rate in the coming decade according to the data the authors have gathered. Under the rapid growth scenario with the implementation of supply-side structural reforms, China's potential economic growth rate will reach an average of 6.5% and 5.8% respectively in the 13th Five-year Plan (2016-2020) and 14th Five-year Plan (2021-2025) periods. These rates are 0.2 and 0.3 percentage points higher, respectively, than that under the baseline scenario with the inertia of historic trends. In implementing supply-side structural reforms, China must transform governmental functions, break monopolies, create a comprehensive competitive market environment, foster the creation of pro-innovation mechanisms, refocus on quality and efficiency, and raise capital utilization and labor productivity.
文摘Different from other methodologies for the forecasting of China's economic growth rate, this paper forecast of future potential growth rates from the end of China's demographic dividends, and then identified it as a growth target. Official promulgation of non-binding targets will guide social expectation, assist in government policy-making, boost confidence in consumers, and provide guidance for producers and investors. Based on our estimation results, we suggest that during the 13th Five-Year Plan period, a GDP growth target between 6. 5% and 7% would be appropriate.
基金an outcome of Study on China’s Potential Economic Growth Calculations,which is a major program of the National Social Sciences Foundation(Grant No.12AZD096)~~
文摘China has entered a crucial period of further growth and restructuring that will last until 2025. Based on a review of the major factors affecting China's potential economic growth, this paper has created an integrated economic system model consisting of system dynamics, econometrics, and input-output for the forecast of China's economic size and structure by 2025. Analysis shows that prior to 2025, China will be able to maintain a potential annual economic growth rate of 5.7%-7.2%. Faced with an international environment of a possible slowdown of advanced economies and diminishing demographic dividends, China needs to further expedite its urbanization process, enhance R&D and education spending, increase total factor productivity (TFP), vigorously develop the tertiary sector, and expand consumption in order to achieve the optimistically estimated growth of 6.6%-7.4% during the period of 2015-2025. Economic growth should be accompanied by the upgrade of industry structure and improvement of investment and consumption structures.
基金supported by the National Natural Science Foundation of China (U21A20361 and 82130039 to Y.W.Z.)Fundamental Research Funds for the Central Universities (20720220133 to Y.W.Z.)+2 种基金Natural Science Foundation of Fujian Province (2021J02057 to Q.L.M.)Science and Technology Plan Projects of Fujian Province (2020Y2015 to Z.X.W.)2020 Joint Support of Key Projects on Health Care (3502Z20209005 to Z.X.W.)。
文摘Synaptic dysfunction is an important pathological hallmark and cause of Alzheimer's disease(AD).High-frequency stimulation(HFS)-induced long-term potentiation(LTP)has been widely used to study synaptic plasticity,with impaired LTP found to be associated with AD.However,the exact molecular mechanism underlying synaptic plasticity has yet to be completely elucidated.Whether genes regulating synaptic plasticity are altered in AD and contribute to disease onset also remains unclear.Herein,we induced LTP in the hippocampal CA1 region of wildtype(WT)and AD model mice by administering HFS to the CA3 region and then studied transcriptome changes in the CA1 region.We identified 89 genes that may participate in normal synaptic plasticity by screening HFS-induced differentially expressed genes(DEGs)in mice with normal LTP,and 43 genes that may contribute to synaptic dysfunction in AD by comparing HFS-induced DEGs in mice with normal LTP and AD mice with impaired LTP.We further refined the 43 genes down to 14 by screening for genes with altered expression in pathological-stage AD mice without HFS induction.Among them,we found that the expression of Pygm,which catabolizes glycogen,was also decreased in AD patients.We further demonstrated that down-regulation of PYGM in neurons impaired synaptic plasticity and cognition in WT mice,while its overexpression attenuated synaptic dysfunction and cognitive deficits in AD mice.Moreover,we showed that PYGM directly regulated energy generation in neurons.Our study not only indicates that PYGM-mediated energy production in neurons plays an important role in synaptic function,but also provides a novel LTP-based strategy to systematically identify genes regulating synaptic plasticity under physiological and pathological conditions.
文摘Objective It is known that free radicals are involved in neurodegeneration and cognitive dysfunction, as seen in Alzheimer's disease (AD) and aging. The present study examines the protective effects of aniracetam against H2O2- induced toxicity to neuron viability, mitochondria potential and hippocampal long-term potentiation (LTP). Methods Tetrazolium salt 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide (MTT) was used to detect neuronal viability. MitoTracker Red (CMX Ros), a fluorescent stain for mitochondria, was used to measure mitochondria potential. Electrophysiological technique was carried out to record hippocampual LTE Results H2O2 exposure impaired the viability of neurons, reduced mitochondria potential, and decreased LTP in the CA region of hippocampus. These deficient effects were significantly rescued by pre-treatment with aniracetam (10 ~100μmol/L). Conclusion These results indicate that aniracetam has a strong neuroprotective effect against H2O2-induced toxicity, which could partly explain the mechanism of its clinical application in neurodegenerative diseases.
文摘BACKGROUND: Pattern- visual evoked potential (PVEP) can reflect the functional status of retinal ganglial cells (RGC) and visual cortex, and is an objective examination for visual pathway function. It is a unique method for objectively examining the optic nerve function of optic ganglion cells. OBJECTIVE: To observe the effects of nerve growth factor (NGF) on PVEF in the treatment of optic nerve contusion, evaluate the clinical efficacy of NGF, and make an efficacy comparison with vitamin B12. DESIGN: A randomly grouping, controlled observation. SETTING: Department of Ophthalmology, Tangshan Gongren Hospital Affiliated to Hebei Medical University. PARTICIPANTS: Forty patients with optic nerve contusion caused by eye trauma, who received the treatment in the Tangshan Worker Hospital Affiliated to Hebei Medical University between January 2006 and June 2007, were recruited in this study. The involved 40 patients, including 34 males and 6 females, were aged 14-59 years. They were confirmed to have optic nerve contusion by ophthalmologic consultation combined with history of disease and orbital CT examination. Informed consents of treatments and detected items were obtained from all the patients. The patients were randomly divided into 2 groups with 20 in each: NGF group and vitamin B12 group. METHODS: Conservative treatment was used in the two groups. In addition, patients in the NGF group were intramuscularly injected with NGF solution 18 μg /time, once a day. Those in the vitamin B12 group were injected by the same method with common vitamin B12 of 500 μg combined with vitamin B1 of 100 mg, once a day. MAIN OUTCOME MEASURES: PVEP examination was conducted in all the patients before, one and two weeks after treatment, and latency and amplitude at P100 were detected. RESULTS: Forty patients with optic nerve contusion participated in the final analysis. Before treatment, significant differences in the latency and amplitude at P100 were not found in patients between two groups (P 〉 0.05). For each patient in the NGF group, the latency of PVEP at P100 was significantly shortened, and the amplitude was significantly increased one and two weeks after treatment as compared with vitamin B12 group(t =2.06-2.34, P 〈 0.05). CONCLUSION: NGF treatment can obviously improve the visual function of patients with optic nerve contusion. The curative effect of NGF is superior to vitamin B12.
文摘BACKGROUND: Long-term potentiation of cornu dorsale medullae spinalis field potential in adult rats has already been reported; however, there is lack of correlated researches on naenonate, infant and adult rats which have different responses to pain conduction information.OBJECTIVE: To observe the various effects of electric stimulation at sciatic nerve on long-term potentiation of evoked field potential at superficial layer of cornu dorsale medullae spinalis of rats at various developmental phases and analyze manifestations of pain conduction information at superficial layers ( Ⅰ - Ⅱ)of cornu dorsale medullae spinalis in immature rats.DESIGN: Grouping controlled study.SETTING: Department of Physiology, Medical College of Wuhan University.MATERIALS: The experiment was carried out in the Laboratory of Physiology (provincial laboratory),Medical College of Wuhan University from March 2006 to May 2007. A total of 27 healthy male Sprague-Dawley (SD) rats, 17- 90 days old, SPF grade, weighing 41 -200 g, were provided by Experimental Animal Center, Medical College of Wuhan University.METHODS: Based on their birthdays, rats were divided into naenonate group (17 - 20 days old, weighing 41-52 g, n =10), infant group (35 - 50 days old, weighing 87 - 125 g, n =10) and adult group (60 - 90 days old, weighing 180 -200 g, n =7). Left sciatic nerve was separated and stimulated with single square wave (15 V, 0.5 ms). Meanwhile, evoked field potential was recorded at superficial layers of lateral T13 - L1 cornu dorsale medullae spinalis and then stimulated with high-frequent and high-intensive tetanizing current (30 -40 V, 0.5 ms, 100 Hz, 1s per bundle, 10s in bundle interval) four times. After the operation, onset of long-term potentiation was observed; meanwhile, amplitude changes and latency of field potential were analyzed.MAIN OUTCOME MEASURES: Amplitude and latency changes of field potential at superficial layers of cornu dorsale medullae spinalis of rats in the three groups.RESULTS: A total of 27 accepted rats were involved in the final analysis. ① Amplitude changes: Electric stimulation at sciatic nerve with high-frequent and high-intensive tetanizing current could induce evoked field potential at superficial layers (Ⅰ-Ⅱ ) of cornu dorsale medullae spinalis in the three groups.Long-term potentiation in the naenonate group manifested that amplitude of A-kind never fiber was raised and there was significant difference (P〈0.05). In addition, average amplitude was increased and there was obviously significant difference (P〈0.01). Long-term potentiation in the infant group manifested that amplitude of C-kind never fiber was raised and there was significant difference (P〈0.01); while, long-term potentiation in the adult group manifested that amplitude of C-kind never fiber was raised and there was significant difference (P〈0.01). Otherwise, latencies in the three groups were all shortened. ② Latency changes: Average latency of A-kind nerve fiber in the naenonate group was shortened and there was significant difference (P〈0.01); in addition, evoked potential of C-kind nerve fiber was low and latency was immovable. There was no significant difference before and after high-frequent and high-intensive electric stimulation (P〉0.05). Average latency of C-kind nerve fiber in the infant group was shortened and there was significant difference (P〈0.01); in addition, evoked potential of A-kind nerve fiber was stable and latency was immovable. There was no significant difference before and after high-frequent and high-intensive electric stimulation (P〉0.05). Average latency of C-kind nerve fiber in the adult group was shortened and there was significant difference (P〈0.01); in addition, evoked potential of A-kind nerve fiber was stable and latency was immovable. There was no significant difference before and after high-frequent and high-intensive electric stimulation.CONCLUSION: Evoked field potential at superficial layer of comu dorsale medullae spinalis can be recorded through electric stimulation at sciatic nerve. Single stimulation and tetanizing electric stimulation can cause different characteristics of evoked field potential in rats at various developmental phases.Superficial layer of cornu dorsale medullae spinalis of naenonate rats is mainly caused by A-kind nerve fiber which participants in pain conduction and formation of pain sensitivity; however, that of infant and adult rats mainly depends on C-kind nerve fiber.
基金the National Social Sciences Foundation Program "A Study on the Effects of Changing Demographic Structure on China's Economic Deceleration and Countermeasures"
文摘Due to diminishing demographic dividend characterized by a falling workingage population and rising dependency ratio, China's long-term potential growth rates will keep declining, likely to be a mere 6.6% during the 13 th Five-Year Plan period(2016-2020). China's economic growth sustainability hinges upon its transition from the previous dependence on demographic dividend to the future reform dividend. In the growth accounting equation, we have simulated various reform initiatives and arrived at the following findings. First, although both the labor participation rate and TFP can increase China's potential growth rate, the former will only achieve a short-term growth effect, which will diminish in the long run. By contrast, the growth effect of TFP demonstrates the tendency of continuous increase. This further indicates that China's economic growth will increasingly rely on TFP improvement instead of traditional factor input. Second, different from the diminishing growth effect of enrolment rate, training may play a pivotal role in human capital development to significantly enhance potential growth rates. Third, if all reform initiatives can achieve their expected effects, integrated reform dividends may reach one or two percentage points of China's potential growth rate.
文摘In this paper, we study the following Schrödinger-Kirchhoff equation where V(x) ≥ 0 and vanishes on an open set of R<sup>2</sup> and f has critical exponential growth. By using a version of Trudinger-Moser inequality and variational methods, we obtain the existence of ground state solutions for this problem.
文摘In this paper a general formula for plastic potential including isotropic ductile damage has been present ed on the basis of the thermodynamics for irreversible process and internal variable the- ory.With this formula the mass conservation law is satisfied and it also contains a series of unknow coefficients which are the function of macro equivalent stress and the average micro equivalent stress and an unknown function which is the function of two generalized forces. The approximate yield surface equation for isotropically damaged materials is developed.Using this equation the void growth rate is calculated for nonlinear material containing voids.The present re- sults are in good agreement with the numerical results given by the cell model.
基金Sponsored by Liquid Specialties Project(Grant No.2008ZX07211-007)
文摘In this test,we used phytoplankton assay procedure to carry out determinations of phytoplankton growth potential and limiting nutrients in Gengjing reservoir.The test results revealed that,in Gengying reservoir waters,the phytoplankton growth potential of the autoclaved-filtrates and the filtrates are from 0.2 to 2.1 mg/L and from 0 to 1.0 mg/L,and in waterway waters,those of the autoclaved-filtrates and the filtrates are from 0 to 3.3 mg/L and from 0 to 2.2 mg/L.The phytoplankton growth potential of the autoclaved filtrates is approximately two times higher than those of the filtrates.When phosphorus is adjusted beyond 0.5 mg/L,the growth of the phytoplankton is especially very high.Moreover,the limiting concentration of the phosphorus for the growth of phytoplankton is in the range of 0.025 to 0.05 mg/L;the phytoplankton growth potential of the grit chamber sediment samples is higher than those of the waterway sediment.
文摘To study the osteogenic potential of cultured bone marrow stromal cells transfected with transforming growth factor β 1 gene in vitro , cultured BMSCs were transfected with the complexes of pcDNA 3 TGF β 1 and Lipofectamine Reagent in vitro . The cell proliferation was detected by MTT method and the morphological features of transfected BMSCs was observed. ALP stains and PNP method were used to measure ALP activity. In addition, the collagen type Ⅰ propeptides and mineralized matrixes were examined by immunohistochemical staining and tetracycline fluorescence labeling respectively. The morphological and biological characters of the transfected BMSCs were similar to those of osteoblasts and the cell proliferation was promoted. The cell layer displayed strong positive reaction for ALP stains and immunohistochemical staining. ALP activity and collagen type Ⅰ expression increased remarkably after transfection. Mineralized matrixes formed earlier and more in transfected BMSCs as compared with control group. It is concluded that transfecting with TGF β 1 gene could promote the osteogenic potential of cultured BMSCs.
文摘Plants which contain unisexual flowers are subjected to genetic degradation and yield capacity reduction due to the easily cross-pollination.Sponge gourd,one of species of the Cucurbitaceae which is predominantly cross-pollinating,is cultivated to widely use as vegetable in Vietnamese daily meals.The aim of this experiment was to evaluate the growth potential and fruit quality including fruit aroma of sponge gourd inbred lines.Pure line selection has been performed using self-pollinated method,so that sponge gourd lines would be recovered with high yielding and aroma and thereby recommended for further crop system in Thua Thien Hue province,Central Vietnam.The experiment was conducted in a randomized complete block design(RCBD)with three replications during the winter-spring season in 2017.Agronomical data were observed and analyzed on seven inbred lines(1-MN1,1-MN2,5-MN1,7-MN1,13-MN2,15-MN1 and 15-MN2)derived from B29 accession(GBVN006904).The results indicated that inbred lines 13-MN2,1-MN2 and 15-MN1 attained more highly fruit weight and yield compared to the others.Four inbred lines consisting of 5-MN1,7-MN1,15-MN1 and 15-MN2 still retained the light aroma after boiling.The inbred lines 1-MN2,7-MN1,13-MN2 and 15-MN1 are considered for appropriately using in breeding program of new luffa.
基金Supported by Soft Science Project of Science & Technology Department of Xinjiang Uygur Autonomous Region:The Study on the Potential of Internal Income Growth of Xinjiang Agriculture(200942140)
文摘Agricultural structure adjustment has always been the important factors influencing Xinjiang agricultural internal income growth.On the basis of the planting scale,productivity and price in 2010,the paper measured the contributions made by agricultural structure adjustment to Xinjiang agricultural internal income growth through structural optimization.Linear programming model was established by Lingo software,to optimize the structure of planting,horticulture,animal husbandry in Xinjiang and analyze the internal agricultural income growth potential.After structure optimization,Xinjiang agricultural production value will reach 1231.44×108yuan and the farmers'income of production and management will reach 9851yuan.The greatest potential for Xinjiang agricultural internal income growth was husbandry accounting for 41.33% of the total production value.The next one was horticulture,whose share of the total production value has raised to 17.43% from 10%.Fruit industry and animal husbandry will become the pillars of future income growth.There are still some income growth spaces in Xinjiang internal agriculture though the agricultural structure adjustment.The agricultural production value will increase by 44.32%and farmers'production and management income will increase by 68.83%.That will be one of the most important ways to tap the future potential of agriculture internal income growth.
基金supported by the Natural Science Foundation of China(NSFC,30972512 and 81202182)the Research Foundation for the Doctoral Program of Higher Education(20121417110002)
文摘Objective To explore the effects of exposure to aluminum (AI) on long-term potentiation (LTP) and AMPA receptor subunits in rats in vivo. Methods Different dosages of aluminum-maltolate complex [Al(mal)3] were given to rats via acute intracerebroventricular (i.c.v.) injection and subchronic intraperitoneal (i.p.) injection. Following AI exposure, the hippocampal LTP were recorded by field potentiation technique in vivo and the expression of AMPAR subunit proteins (GluR1 and GluR2) in both total and membrane-enriched extracts from the CA1 area of rat hippocampus were detected by Western blot assay. Results Acute AI treatment produced dose-dependent suppression of LTP in the rat hippocampus and dose-dependent decreases of GluRz and GluR2 in membrane extracts; however, no similar changes were found in the total cell extracts, which suggests decreased trafficking of AMPA receptor subunits from intracellular pools to synaptic sites in the hippocampus. The dose-dependent suppressive effects on LTP and the expression of AMPA receptor subunits both in the membrane and in total extracts were found after subchronic AI treatment, indicating a decrease in AMPA receptor subunit trafficking from intracellular pools to synaptic sites and an additional reduction in the expression of the subunits. Conclusion Al(mal)3 obviously and dose-dependently suppressed LTP in the rat hippocampal CA1 region in vivo, and this suppression may be related to both trafficking and decreases in the expression of AMPA receptor subunit proteins. However, the mechanisms underlying these observations need further investigation.
基金supported by Major State Basic Research Program of China(Grant No.2013CB733801)
文摘The long-term enhancement in glutamate receptor mediated excitatory responses has been observed in stroke model. This pathological form of plasticity, termed post-ischemic long-term potentiation (i-LTP), points to functional reorganization after stroke. Little is known, however, about whether and how this i-LTP would affect subsequent induction of synaptic plasticity. Here, we first directly confirmed that i-LTP was induced in the endothelin-l-induced ischemia model as in other in vitro models. We also demonstrated increased expression of NR2B, CaMKII and p-CaMKII, which are reminiscent of i-LTP. We further induced LTP of field excitatory post- synaptic potentials (fEPSPs) on CA1 hippocampal neurons in peri-infarct regions of the endothelin-l-induced mini-stroke model. We found that LTP of fEPSPs, induced by high-frequency stimulation, displayed a progressive impairment at 12 and 24 hours after ischemia. Moreover, using in vivo multi-channel recording, we found that the local field potential, which represents electrical property of cell ensembles in more restricted regions, was also dam- pened at these two time points. These results suggest that i-LTP elevates the induction threshold of subsequent synap- tic plasticity. Our data helps to deepen the knowledge of meta-synaptic regulation of plasticity after focal ischemia.
基金supported by the Natural Science Foundation of China(NSFC,81202182)the Doctoral startup Foundation of Shanxi Medical University(03201413)
文摘Objective To explore the role of RAS/PI3K pathway in the impairment of long-term potentiation (LTP) induced by acute aluminum (AI) treatment in rats in vivo. Methods First, different dosages of aluminum-maltolate complex [Al(mal)3] were given to rats via acute intracerebroventricular (i.c.v.) injection. Following AI exposure, the RAS activity of rat hippocampus were detected by ELISA assay after the hippocampal LTP recording by field potentiation technique in vivo. Second, the antagonism on the aluminum-induced suppression of hippocampal LTP was observed after the treatment of the RAS activator epidermal growth factor (EGF). Finally, the antagonism on the downstream molecules (PKB activity and the phosphorylation of GluR1 $831 and $845) were tested by ELISA and West-blot assays at the same time. Results With the increasing aluminum dosage, a gradually decreasing in RAS activity of the rat hippocampus was produced after a gradually suppressing on LTP. The aluminum-induced early suppression of hippocampal LTP was antagonized by the RAS activator epidermal growth factor (EGF). And the EGF treatment produced changes similar to those observed for LTP between the groups on PKB activity as well as the phosphorylation of GluR1 S831 and s845. Conclusion The RAS-PI3K/PKB-GluR1 S831 and S845 signal transduction pathway may be involved in the inhibition of hippocampal LTP by aluminum exposure in rats. However, the mechanisms underlying this observation need further investigation.
基金supported by the National Basic Research Program of China(No.2002CB512907)the National Natural Science Foundation of China(No.30630057).
文摘Objective To explore the changes in spatial learning performance and long-term potentiation (LTP) which is recognized as a component of the cellular basis of learning and memory in normal and lead-exposed rats after administration of melatonin (MT) for two months. Methods Experiment was performed in adult male Wistar rats (12 controls, 12 exposed to melatonin treatment, 10 exposed to lead and 10 exposed to lead and melatonin treatment). The lead-exposed rats received 0.2% lead acetate solution from their birth day while the control rats drank tap water. Melatonin (3 mg/kg) or vehicle was administered to the control and lead-exposed rats from the time of their weaning by gastric gavage each day for 60 days, depending on their groups. At the age of 81-90 days, all the animals were subjected to Morris water maze test and then used for extracellular recording of LTP in the dentate gyrus (DG) area of the hippocampus in vivo. Results Low dose of melatonin given from weaning for two months impaired LTP in the DG area of hippocampus and induced learning and memory deficit in the control rats. When melatonin was administered over a prolonged period to the lead-exposed rats, it exacerbated LTP impairment, learning and memory deficit induced by lead. Conclusion Melatonin is not suitable for normal and lead-exposed children.