To explore the effects of Tanshinone Ⅱ A on the proliferation, apoptosis and gene expression of p53 and bcl-2 in human gastric carcinoma MKN-45 cells. Cell count and MTT assay were used to study the proliferation-inh...To explore the effects of Tanshinone Ⅱ A on the proliferation, apoptosis and gene expression of p53 and bcl-2 in human gastric carcinoma MKN-45 cells. Cell count and MTT assay were used to study the proliferation-inhibiting effect of Tanshinone Ⅱ A on MKN-45 cells. The effect of Tanshinone Ⅱ A on the cell cycle and apoptosis of MKN-45 cells were examined by propidium iodide (PI) staining and flow cytometry. Semi-quantitative RT-PCR was used to further verify the ex- pression of p53 and bcl-2 gene after exposure to Tanshinone Ⅱ A in MKN-45 cells. The results showed that Tanshinone Ⅱ A significantly inhibited the growth and proliferation of MKN-45 cells in a dose- and time-dependent manner (P〈0.05). Tanshinone Ⅱ A arrested MKN-45 cells in G2/M phase which led to an obvious accumulation of G2/M phase cells while decreased number of Go/G1 phase cells. This resulted in apoptosis of MKN-45 cells and the apoptosis rate was as high as 43.91% after treatment with 2.0 lag/mL Tanshinone Ⅱ A for 96 h. It was also found that Tanshinone Ⅱ A up-regulated expression of p53 gene and down-regulated expression of bcl-2 gene. The cytostatic and antiproliferative effect of Tanshinone Ⅱ A makes it a promising anticancer agent for the treatment of gastric carcinoma.展开更多
Cover crops are the plants which are grown to improve soil fertility, prevent soil erosion, enrichment and protection of soil, and enhance nutrient and water availability, and quality of soil. Cover crops provide seve...Cover crops are the plants which are grown to improve soil fertility, prevent soil erosion, enrichment and protection of soil, and enhance nutrient and water availability, and quality of soil. Cover crops provide several benefits to soils used for agriculture production. Cover crops are helpful in increasing and sustaining microbial biodiversity in soils. We summarized the effect of several cover crops in soil properties such as soil moisture content, soil microbial activities, soil carbon sequestration, nitrate leaching, soil water, and soil health. Selection of cover crops usually depends on the primary benefits which are provided by cover crops. Other factors may also include weather conditions, time of sowing, either legume or non-legume and timing and method of killing of a cover crop. In recent times, cover crops are also used for mitigating climate change, suppressing weeds in crops and increasing exchangeable nutrients such as Mg2+ and K+. Cover crops are also found to be economical in long-term experiment studies. Although some limitations always come with several benefits. Cover crops have some problems including the method of killing, host for pathogens, regeneration, and not immediate benefits of using them. Despite the few limitations, cover crops improve the overall health of the soil and provide a sustainable environment for the main crops.展开更多
Matrix metalloproteinase 2(MMP2) has been shown to play an important role in several steps of cancer development.The-1306C/T polymorphism of the MMP2 gene displays a strikingly lower promoter activity than the T allel...Matrix metalloproteinase 2(MMP2) has been shown to play an important role in several steps of cancer development.The-1306C/T polymorphism of the MMP2 gene displays a strikingly lower promoter activity than the T allele,and the CC genotype in the MMP2 promoter has been reported to associate with the development of several cancers.To assess the contribution of the MMP2-1306C/T polymorphism to the risk of nasopharyngeal carcinoma(NPC),we conducted a case-control study and analyzed MMP2 genotypes in 370 patients with NPC and 390 frequency-matched controls using real-time PCR-based TaqMan allele analysis.We found that subjects with the CC genotype had an increased risk(OR = 1.55,95% CI = 1.05-2.27) of developing NPC compared to those with the CT or TT genotypes.Furthermore,we found that the risk of NPC was markedly increased in subjects who were smokers(OR = 15.04,95% CI = 6.65-33.99),heavy smokers who smoked ≥20 pack-years(OR = 18.66,95% CI = 7.67-45.38),or young(<60 years) at diagnosis(OR = 1.52,95% CI = 1.01-2.29).Our results provide molecular epidemiological evidence that the MMP2-1306C/T promoter polymorphism is associated with NPC risk,and this association is especially noteworthy in heavy smokers.展开更多
BACKGROUND: Extracts of ginkgo biloba leaves have been reported to improve nerve function and activity in Alzheimer's disease, which is associated with reduced secretion of cholinergic neurotransmitter in hippocampa...BACKGROUND: Extracts of ginkgo biloba leaves have been reported to improve nerve function and activity in Alzheimer's disease, which is associated with reduced secretion of cholinergic neurotransmitter in hippocampal neurons. OBJECTIVE: To validate the protective effect of bilobalide B against in vitro injury of cholinergic neurons of the hippocampus induced by combined cholesterol and apoE4 DESIGN, TIME AND SETTING: This randomized, controlled animal experiment was performed in the Pathology Laboratory, Tianjin University of Traditional Chinese Medicine from July 2003 to July 2006. MATERIALS: Neonatal Wistar rats, 1-day-old, both male and female, and mean body mass of 5 g were selected for this study. Cholesterol and apolipoprotein E4 (apoE4) were purchased from Sigma Company (USA), bilobalide B was purchased from Tianjin Zhongyi Pharmaceutical Factory, batch number 20050312. METHODS: Hippocampal neurons were divided into three groups: a normal control group (routinely added media), a model group (exposed to media containing 40 mg/L cholesterol and 30 mg/L apoE4 for 24 hours) and a bilobalide B group (exposed to media containing 160 mg/L bilobalide B for 16 hours, and then with addition of 40 mg/L cholesterol and 30 mg/L apoE4 for an additional 24 hours). MAIN OUTCOME MEASURES: Levels of acetylcholine (ACh) and activity of acetylcholinesterase (ACHE) and choline acetyltransferase (CHAT) in hippocampal neurons were determined by microdosage hydroxylamine colorimetry, hydroxylamine colorimetry and radiological chemistry, respectively. RESULTS: The ACh level was significantly lower in the model group than that in the normal control group (P 〈 0.01), while it was markedly higher in the bilobalide B group than in the model group (P 〈 0.05). Activity of AChE was significantly decreased in the model group compared with the normal control group (P 〈 0.05). However, there was no significant difference between the model group and the bilobalide B group (P 〉 0.05). Activity of ChAT was significantly lower in the model group than in the normal control group (P 〈 0.01), while the activity was significantly higher in the bilobalide B group than in the model group (P 〈 0.05). CONCLUSION: Bilobalide B can enhance the ACh level of hippocampal neurons damaged by combined cholesterol and apoE4, by promoting the synthesis, but not the degradation, of ACh.展开更多
We investigate the interface-guided mode of Lamb waves in a phononic crystal heterostructures plate, which is com- posed of two different semi-infinite phononic crystal (PC) plates. The interface-guided modes of the...We investigate the interface-guided mode of Lamb waves in a phononic crystal heterostructures plate, which is com- posed of two different semi-infinite phononic crystal (PC) plates. The interface-guided modes of the Lamb wave can be obtained by the lateral lattice slipping or by the interface longitudinal gliding. Significantly, it is observed that the condition to generate the interface-guided modes of the Lamb wave is more demanding than that of the studied fluid-fluid system. The interface-guided modes are strongly affected not only by the relative movement of the two semi-infinite PCs but also by the thickness of the PC plate.展开更多
Background:The current World Health Organization(WHO) classification of nasopharyngeal carcinoma(NPC) con?veys little prognostic information.This study aimed to propose an NPC histopathologic classification that can p...Background:The current World Health Organization(WHO) classification of nasopharyngeal carcinoma(NPC) con?veys little prognostic information.This study aimed to propose an NPC histopathologic classification that can poten?tially be used to predict prognosis and treatment response.Methods:We initially developed a histopathologic classification based on the morphologic traits and cell differentia?tion of tumors of 2716 NPC patients who were identified at Sun Yat?sen University Cancer Center(SYSUCC)(training cohort).Then,the proposed classification was applied to 1702 patients(retrospective validation cohort) from hospitals outside SYSUCC and 1613 patients(prospective validation cohort) from SYSUCC.The efficacy of radiochemotherapy and radiotherapy modalities was compared between the proposed subtypes.We used Cox proportional hazards models to estimate hazard ratios(HRs) with 95% confidence intervals(CI) for overall survival(OS).Results:The 5?year OS rates for all NPC patients who were diagnosed with epithelial carcinoma(EC;3708 patients),mixed sarcomatoid?epithelial carcinoma(MSEC;1247 patients),sarcomatoid carcinoma(SC;823 patients),and squamous cell carcinoma(SCC;253 patients) were 79.4%,70.5%,59.6%,and 42.6%,respectively(P < 0.001).In mul?tivariate models,patients with MSEC had a shorter OS than patients with EC(HR = 1.44,95% CI = 1.27–1.62),SC(HR = 2.00,95% CI = 1.76–2.28),or SCC(HR = 4.23,95% CI = 3.34–5.38).Radiochemotherapy significantly improved survival compared with radiotherapy alone for patients with EC(HR 49–0.75),and possibly for those with SCC(HR = 0.67,95% CI = 0.56–0.80),MSEC(HR = 0.58,95% CI = 0..74–1.28).= 0.63;95% CI = 0.40–0.98),but not for patients with SC(HR = 0.97,95% CI = 0Conclusions:The proposed classification offers more information for the prediction of NPC prognosis compared with the WHO classification and might be a valuable tool to guide treatment decisions for subtypes that are associ?ated with a poor prognosis.展开更多
Rice-wheat is the predominant cropping system of fertile soils of Indian, Pakistan, Bangladesh and Nepal falling in the alluvial Indo-Gangetic Plains (IGP). Management of rice residues produced after the harvest of ri...Rice-wheat is the predominant cropping system of fertile soils of Indian, Pakistan, Bangladesh and Nepal falling in the alluvial Indo-Gangetic Plains (IGP). Management of rice residues produced after the harvest of rice crop and before sowing of the next wheat crop is a big challenge in that area. Mostly farmers burn rice residues assuming it low profile fodder and of little use. Burning of rice residues deprives the fields from many plant nutrients as they are lost during burning along with environmental pollutions and other issues. A field study was conducted for two consecutive years at the experimental area of the Department of Agronomy, Punjab Agricultural University, Ludhiana (India) to assess the impact of different rice residue management techniques and weed control treatments in wheat on soil available plant nutrients in rice-wheat cropping system. The experiment was laid out in split plot design with three replications. In main plots, five rice residue management treatments viz., no rice residue, rice residue 5 t·ha-1 (surface), rice residue 6 t·ha-1 (surface), rice residue 7 t·ha-1 (surface) and rice residue 5 t·ha-1 (incorporation) were settled and in sub plots, four weed control treatments i.e. clodinafop 60 t·ha-1, sulfosulfuron 25 t·ha-1, mesosulfuron + iodosulfuron 12 t·ha-1 and control (unweeded) were arranged. Results of the study revealed that surface application as well as incorporation of rice residues improved the organic carbon and NPK status than no rice residues. Among the residue management practices, incorporation of rice residues 5 t·ha-1 significantly improved the soil organic carbon, available nitrogen, phosphorus and potassium than no rice residue treatment in the 0 - 15 soil layer during both the years. Same trend was observed for 15 - 30 cm soil layer but differences were less wide than 0 - 15 cm soil layer. Among the weed control treatments, organic carbon was not significantly influenced. Herbicide treated plots registered significantly higher available nitrogen, phosphorus and potassium than control (unweeded) treatment in the 0 - 15 cm soil layer during both the years.展开更多
The thermodynamic properties of dibenzofurans (DFs), xanthones (XTs) and an-thraquinones (AQs) with one and two positions substituted with hydroxyls in the ideal gas state at 298.15 K and 1.013×10^5 pa were...The thermodynamic properties of dibenzofurans (DFs), xanthones (XTs) and an-thraquinones (AQs) with one and two positions substituted with hydroxyls in the ideal gas state at 298.15 K and 1.013×10^5 pa were calculated at the B3LYP/6-311G^* level using Gaussian 03 program. The isodesmic reactions were designed to calculate the standard free energy of formation (△fG^θ). Three types of hydrogen bonds exist in the three kinds of chemicals and their bond energies were ascertained as 7-15, 15-23 and 49-58 kJ·mo1^-1 respectively by comparing the △fG^θ values. Electronic density topology analysis was applied to validate the strength of bond.展开更多
We investigate the influence of coating layer on acoustic wave propagation in a dispersed random medium consisting of coa.ted fibers.In the strong-scattering regime, the characteristics of wave scattering resonances a...We investigate the influence of coating layer on acoustic wave propagation in a dispersed random medium consisting of coa.ted fibers.In the strong-scattering regime, the characteristics of wave scattering resonances are found to evolve regularly with the properties of the coating layer.By theoretical calculation,frequency gaps are found in acoustic excitation spectra in a random medium.The scattering cross section results present the evolution of scattering resonances with the properties of the coating layer,which offers a good explanation for the change of the frequency gaps.The velocity of the propagation quasi-mode is also shown to depend on the filling fraction of the coating layer.We use the generalized coherent potential-approximation approach to solve acoustic wave dispersion relations in a complicated random medium consisting of coating-structure scatterers.It is shown that our model reveals subtle changes in the behavior of the acoustic wave propagating quasi-modes.展开更多
The complete band gaps (CBGs) of shallow water waves propagating over bottoms with periodically drilled holes are investigated numerically by the plane wave expansion method. Four different patterns are considered, ...The complete band gaps (CBGs) of shallow water waves propagating over bottoms with periodically drilled holes are investigated numerically by the plane wave expansion method. Four different patterns are considered, containing triangular, square, hexagonal and circular cross-sectioned holes arranged into triangular lattices. Results show that the width of CBGs can be changed by adjusting the orientation of noncircular holes and the effect of hole shape on the width of the maximal CBGs is discussed.展开更多
We present the acoustic band gaps (ABGs) for a geometry of three-dimensional complex acoustic crystals: the NaCl-type structure. By using the super cell method based on the plane-wave expansion method (PWE), we s...We present the acoustic band gaps (ABGs) for a geometry of three-dimensional complex acoustic crystals: the NaCl-type structure. By using the super cell method based on the plane-wave expansion method (PWE), we study the three configurations formed by water objects (either a sphere of different sizes or a cube) located at the vertices of simple cubic (SC) lattice and surrounded by mercury background. The numerical results show that ABGs larger than the original SC structure for all the three configurations can be obtained by adjusting the length-diameter ratio of adjacent objects but keeping the filling fraction (f = 0.25) of the unit cell unchanged. We also compare our results with that of 3D solid composites and find that the ABGs in liquid composites are insensitive to the shapes as that in the solid composites. We further prove that the decrease of the translation group symmetry is more efficient in creating the ABGs in 3D water-mercury systems.展开更多
Neural tube development comprises neural induction, neural epithelial cell proliferation, and apoptosis, as well as migration of nerve cells. Too much or too little apoptosis leads to abnormal nervous system developme...Neural tube development comprises neural induction, neural epithelial cell proliferation, and apoptosis, as well as migration of nerve cells. Too much or too little apoptosis leads to abnormal nervous system development. The present study analyzed expression and distribution of apoptotic-related factors, including Fas, FasL, and caspase-3, during human embryonic neural tube development. Experimental results showed that increased caspase-3 expression promoted neural apoptosis via a mitochondrial-mediated intrinsic pathway at 4 weeks during early human embryonic neural tube development. Subsequently, Fas and FasL expression increased during embryonic development. The results suggest that neural cells influence neural apoptosis through synergistic effects of extrinsic pathways. Therefore, neural apoptosis during the early period of neural tube development in the human embryo might be regulated by the death receptor induced apoptotic extrinsic pathways.展开更多
We investigate the nonlinear modes in a rotating double well potential with 79T symmetry. Focus on the existence and stability of the nonlinear PT modes in this system, we found that five types of PT modes can stably ...We investigate the nonlinear modes in a rotating double well potential with 79T symmetry. Focus on the existence and stability of the nonlinear PT modes in this system, we found that five types of PT modes can stably exist by given certain parameter settings. The multistable area between these modes are studied numerically and the bistable and tristable areas are delimited. With different input trial wavefunctions, five types of solitary wave modes are identified. We found that the rotating of the potential can significantly affect the power flow of the fundamental harmonic mode, whose effect is absent for the other modes.展开更多
A finite temperature phase diagram of the rotating Bose–Hubbard model,including the crossover between Mott insulator and the normal state,is derived on the frame of the Gutzwiller mean-field theory.In addition,we cal...A finite temperature phase diagram of the rotating Bose–Hubbard model,including the crossover between Mott insulator and the normal state,is derived on the frame of the Gutzwiller mean-field theory.In addition,we calculate the critical temperature of superfluid-normal phase transition.展开更多
The relativistic and distorted wave effects are investigated for the electron momentum distributions of Xe 4d electrons.The theoretical results show good agreements with the experimental data measured previously with ...The relativistic and distorted wave effects are investigated for the electron momentum distributions of Xe 4d electrons.The theoretical results show good agreements with the experimental data measured previously with electron momentum spectroscopy. The distorted wave effect and the relativistic effect are found to play important roles in the low and high momentum regions, respectively.展开更多
Entanglement,quantum steering and Bell nonlocality can be used to describe the distinct quantum correlations of quantum systems.Because of their different characteristics and application fields,how to divide them quan...Entanglement,quantum steering and Bell nonlocality can be used to describe the distinct quantum correlations of quantum systems.Because of their different characteristics and application fields,how to divide them quantitatively and accurately becomes particularly important.Based on the sufficient and necessary criterion for quantum steering of an arbitrary two-qubit T-state,we derive the inequality relations between quantum steering and entanglement as well as between quantum steering and Bell nonlocality for the T-state.Additionally,we have verified those relations experimentally.展开更多
Background:Since 2010,two versions of National Guidelines aimed at promoting the management of ST-segment elevation myocardial infarction (STEMI) have been formulated by the Chinese Society of Cardiology.However,li...Background:Since 2010,two versions of National Guidelines aimed at promoting the management of ST-segment elevation myocardial infarction (STEMI) have been formulated by the Chinese Society of Cardiology.However,little is known about the changes in clinical characteristics,management,and in-hospital outcomes in rural areas.Methods:In the present multicenter,cross-sectional study,participants were enrolled from rural hospitals located in Liaoning province in Northeast China,during two different periods (from June 2009 to June 2010 and from January 2015 to December 2015).Data collection was conducted using a standardized questionnaire.In total,607 and 637 STEMI patients were recruited in the 2010 and 2015 cohorts,respectively.Results:STEMI patients in rural hospitals were older in the second group (63 years vs.65 years,P =0.039).We found increases in the prevalence of hypertension,prior percutaneous coronary intervention (PCI),and prior stroke.Over the past 5 years,the cost during hospitalization almost doubled.The proportion of STEMI patients who underwent emergency reperfusion had significantly increased from 42.34% to 54.47% (P 〈 0.0001).Concurrently,the proportion of primary PCI increased from 3.62% to 10.52% (P 〈 0.0001).The past 5 years have also seen marked increases in the use of guideline-recommended drugs and clinical examinations.However,in-hospital mortality and major adverse cardiac events did not significantly change over time (13.01% vs.10.20%,P =0.121;13.34% vs.13.66%,P =0.872).Conclusions:Despite the great progress that has been made in guideline-recommended therapies,in-hospital outcomes among rural STEMI patients have not significantly improved.Therefore,there is still substantial room for improvement in the quality of care.展开更多
This brief review summarizes recent theoretical and experimental results which predict and establish the existence of quantum droplets(QDs),i.e.,robust two-and three-dimensional(2D and 3D)self-trapped states in Bose-E...This brief review summarizes recent theoretical and experimental results which predict and establish the existence of quantum droplets(QDs),i.e.,robust two-and three-dimensional(2D and 3D)self-trapped states in Bose-Einstein condensates(BECs),which are stabilized by effective self-repulsion induced by quantum fluctuations around the mean-field(MF)states[alias the Lee-Huang-Yang(LHY)effect].The basic models are presented,taking special care of the dimension crossover,2D→3D.Recently reported experimental results,which exhibit stable 3D and quasi-2D QDs in binary BECs,with the inter-component attraction slightly exceeding the MF self-repulsion in each component,and in single-component condensates of atoms carrying permanent magnetic moments,are presented in some detail.The summary of theoretical results is focused,chiefly,on 3D and quasi-2D QDs with embedded vorticity,as the possibility to stabilize such states is a remarkable prediction.Stable vortex states are presented both for QDs in free space,and for singular but physically relevant 2D modes pulled to the center by the inverse-square potential,with the quantum collapse suppressed by the LHY effect.展开更多
Objective: To investigate the protective effects of sodium tanshinone B (STB) on brain damage following focal ischemiareperfusion (I/R) injury through interfering with NmethyIDaspartic acid receptor (NMDAR) and...Objective: To investigate the protective effects of sodium tanshinone B (STB) on brain damage following focal ischemiareperfusion (I/R) injury through interfering with NmethyIDaspartic acid receptor (NMDAR) and excitatory and inhibitory amino acids, and evaluate the potential mechanisms of the neuroprotective activity of STB. Methods: Transient forebrain ischemia was induced by middle cerebral artery occlusion (MCAO). The rats were randomized into a sham operated group, a model group (I/R) and three STB different dose groups. Rats were pretreated with STB at the doses of 4, 8, 16 mg/kg (STB1, STB2, STB3) for 3 days before MCAO. The expression of NMDAR1 was detected by immunohistochemistry and Western blotting. The concentrations of glutamate and λaminobutyric acid (GABA) were analyzed using high performance liquid chromatography. Results: STB treatment reduced neurological defect scores, cerebral infarction volume and brain water content. The levels of NMDAR1 were significantly higher in the I/R and STB1 groups than that of the sham and the STBs groups (P〈0.01). Optical density of NMDAR1 was significantly increased in cornu ammonis (CA)I region of the I/R group (P〈0.05). STB treatment reduced NMDAR1 optical density in the CA1 region (P〈0.01). The levels of glutamate were significantly lower in the hippocampus in the STB3 group than that of the I/R, STB1 and STB2 groups (P〈0.01). Conclusion: Preconditioning with STB appears to be a simple and promising strategy to reduce or even prevent cerebral I/R injury and has potential for future clinical application.展开更多
文摘To explore the effects of Tanshinone Ⅱ A on the proliferation, apoptosis and gene expression of p53 and bcl-2 in human gastric carcinoma MKN-45 cells. Cell count and MTT assay were used to study the proliferation-inhibiting effect of Tanshinone Ⅱ A on MKN-45 cells. The effect of Tanshinone Ⅱ A on the cell cycle and apoptosis of MKN-45 cells were examined by propidium iodide (PI) staining and flow cytometry. Semi-quantitative RT-PCR was used to further verify the ex- pression of p53 and bcl-2 gene after exposure to Tanshinone Ⅱ A in MKN-45 cells. The results showed that Tanshinone Ⅱ A significantly inhibited the growth and proliferation of MKN-45 cells in a dose- and time-dependent manner (P〈0.05). Tanshinone Ⅱ A arrested MKN-45 cells in G2/M phase which led to an obvious accumulation of G2/M phase cells while decreased number of Go/G1 phase cells. This resulted in apoptosis of MKN-45 cells and the apoptosis rate was as high as 43.91% after treatment with 2.0 lag/mL Tanshinone Ⅱ A for 96 h. It was also found that Tanshinone Ⅱ A up-regulated expression of p53 gene and down-regulated expression of bcl-2 gene. The cytostatic and antiproliferative effect of Tanshinone Ⅱ A makes it a promising anticancer agent for the treatment of gastric carcinoma.
文摘Cover crops are the plants which are grown to improve soil fertility, prevent soil erosion, enrichment and protection of soil, and enhance nutrient and water availability, and quality of soil. Cover crops provide several benefits to soils used for agriculture production. Cover crops are helpful in increasing and sustaining microbial biodiversity in soils. We summarized the effect of several cover crops in soil properties such as soil moisture content, soil microbial activities, soil carbon sequestration, nitrate leaching, soil water, and soil health. Selection of cover crops usually depends on the primary benefits which are provided by cover crops. Other factors may also include weather conditions, time of sowing, either legume or non-legume and timing and method of killing of a cover crop. In recent times, cover crops are also used for mitigating climate change, suppressing weeds in crops and increasing exchangeable nutrients such as Mg2+ and K+. Cover crops are also found to be economical in long-term experiment studies. Although some limitations always come with several benefits. Cover crops have some problems including the method of killing, host for pathogens, regeneration, and not immediate benefits of using them. Despite the few limitations, cover crops improve the overall health of the soil and provide a sustainable environment for the main crops.
基金supported in part by grants from the Chinese State Key Basic Research Project (No.2011CB504805)National High Technology Research and Development Program of China (863 Program) (No.20060102A4002)a grant of 985 Project from Ministry of Education of P. R. China
文摘Matrix metalloproteinase 2(MMP2) has been shown to play an important role in several steps of cancer development.The-1306C/T polymorphism of the MMP2 gene displays a strikingly lower promoter activity than the T allele,and the CC genotype in the MMP2 promoter has been reported to associate with the development of several cancers.To assess the contribution of the MMP2-1306C/T polymorphism to the risk of nasopharyngeal carcinoma(NPC),we conducted a case-control study and analyzed MMP2 genotypes in 370 patients with NPC and 390 frequency-matched controls using real-time PCR-based TaqMan allele analysis.We found that subjects with the CC genotype had an increased risk(OR = 1.55,95% CI = 1.05-2.27) of developing NPC compared to those with the CT or TT genotypes.Furthermore,we found that the risk of NPC was markedly increased in subjects who were smokers(OR = 15.04,95% CI = 6.65-33.99),heavy smokers who smoked ≥20 pack-years(OR = 18.66,95% CI = 7.67-45.38),or young(<60 years) at diagnosis(OR = 1.52,95% CI = 1.01-2.29).Our results provide molecular epidemiological evidence that the MMP2-1306C/T promoter polymorphism is associated with NPC risk,and this association is especially noteworthy in heavy smokers.
基金the Natural Science Foundation of Tianjin Educational Bureau, No.20030117
文摘BACKGROUND: Extracts of ginkgo biloba leaves have been reported to improve nerve function and activity in Alzheimer's disease, which is associated with reduced secretion of cholinergic neurotransmitter in hippocampal neurons. OBJECTIVE: To validate the protective effect of bilobalide B against in vitro injury of cholinergic neurons of the hippocampus induced by combined cholesterol and apoE4 DESIGN, TIME AND SETTING: This randomized, controlled animal experiment was performed in the Pathology Laboratory, Tianjin University of Traditional Chinese Medicine from July 2003 to July 2006. MATERIALS: Neonatal Wistar rats, 1-day-old, both male and female, and mean body mass of 5 g were selected for this study. Cholesterol and apolipoprotein E4 (apoE4) were purchased from Sigma Company (USA), bilobalide B was purchased from Tianjin Zhongyi Pharmaceutical Factory, batch number 20050312. METHODS: Hippocampal neurons were divided into three groups: a normal control group (routinely added media), a model group (exposed to media containing 40 mg/L cholesterol and 30 mg/L apoE4 for 24 hours) and a bilobalide B group (exposed to media containing 160 mg/L bilobalide B for 16 hours, and then with addition of 40 mg/L cholesterol and 30 mg/L apoE4 for an additional 24 hours). MAIN OUTCOME MEASURES: Levels of acetylcholine (ACh) and activity of acetylcholinesterase (ACHE) and choline acetyltransferase (CHAT) in hippocampal neurons were determined by microdosage hydroxylamine colorimetry, hydroxylamine colorimetry and radiological chemistry, respectively. RESULTS: The ACh level was significantly lower in the model group than that in the normal control group (P 〈 0.01), while it was markedly higher in the bilobalide B group than in the model group (P 〈 0.05). Activity of AChE was significantly decreased in the model group compared with the normal control group (P 〈 0.05). However, there was no significant difference between the model group and the bilobalide B group (P 〉 0.05). Activity of ChAT was significantly lower in the model group than in the normal control group (P 〈 0.01), while the activity was significantly higher in the bilobalide B group than in the model group (P 〈 0.05). CONCLUSION: Bilobalide B can enhance the ACh level of hippocampal neurons damaged by combined cholesterol and apoE4, by promoting the synthesis, but not the degradation, of ACh.
基金supported by the National Natural Science Foundation of China(Grant Nos.11374068 and 11374066)the Science&Technology Star of Zhujiang Foundation of Guangzhou,China(Grant No.2011J2200013)the Natural Science Foundation of Guangdong,China(Grant No.S2012020010885)
文摘We investigate the interface-guided mode of Lamb waves in a phononic crystal heterostructures plate, which is com- posed of two different semi-infinite phononic crystal (PC) plates. The interface-guided modes of the Lamb wave can be obtained by the lateral lattice slipping or by the interface longitudinal gliding. Significantly, it is observed that the condition to generate the interface-guided modes of the Lamb wave is more demanding than that of the studied fluid-fluid system. The interface-guided modes are strongly affected not only by the relative movement of the two semi-infinite PCs but also by the thickness of the PC plate.
基金supported by grants from the National High Technology Research and Development Program of China(863 Program)(No.2012AA02A501)the Chinese State Key Basic Research Project(No.2011CB504805)the National Natural Science Foundation of China(No.81272952 and No.81472522)
文摘Background:The current World Health Organization(WHO) classification of nasopharyngeal carcinoma(NPC) con?veys little prognostic information.This study aimed to propose an NPC histopathologic classification that can poten?tially be used to predict prognosis and treatment response.Methods:We initially developed a histopathologic classification based on the morphologic traits and cell differentia?tion of tumors of 2716 NPC patients who were identified at Sun Yat?sen University Cancer Center(SYSUCC)(training cohort).Then,the proposed classification was applied to 1702 patients(retrospective validation cohort) from hospitals outside SYSUCC and 1613 patients(prospective validation cohort) from SYSUCC.The efficacy of radiochemotherapy and radiotherapy modalities was compared between the proposed subtypes.We used Cox proportional hazards models to estimate hazard ratios(HRs) with 95% confidence intervals(CI) for overall survival(OS).Results:The 5?year OS rates for all NPC patients who were diagnosed with epithelial carcinoma(EC;3708 patients),mixed sarcomatoid?epithelial carcinoma(MSEC;1247 patients),sarcomatoid carcinoma(SC;823 patients),and squamous cell carcinoma(SCC;253 patients) were 79.4%,70.5%,59.6%,and 42.6%,respectively(P < 0.001).In mul?tivariate models,patients with MSEC had a shorter OS than patients with EC(HR = 1.44,95% CI = 1.27–1.62),SC(HR = 2.00,95% CI = 1.76–2.28),or SCC(HR = 4.23,95% CI = 3.34–5.38).Radiochemotherapy significantly improved survival compared with radiotherapy alone for patients with EC(HR 49–0.75),and possibly for those with SCC(HR = 0.67,95% CI = 0.56–0.80),MSEC(HR = 0.58,95% CI = 0..74–1.28).= 0.63;95% CI = 0.40–0.98),but not for patients with SC(HR = 0.97,95% CI = 0Conclusions:The proposed classification offers more information for the prediction of NPC prognosis compared with the WHO classification and might be a valuable tool to guide treatment decisions for subtypes that are associ?ated with a poor prognosis.
文摘Rice-wheat is the predominant cropping system of fertile soils of Indian, Pakistan, Bangladesh and Nepal falling in the alluvial Indo-Gangetic Plains (IGP). Management of rice residues produced after the harvest of rice crop and before sowing of the next wheat crop is a big challenge in that area. Mostly farmers burn rice residues assuming it low profile fodder and of little use. Burning of rice residues deprives the fields from many plant nutrients as they are lost during burning along with environmental pollutions and other issues. A field study was conducted for two consecutive years at the experimental area of the Department of Agronomy, Punjab Agricultural University, Ludhiana (India) to assess the impact of different rice residue management techniques and weed control treatments in wheat on soil available plant nutrients in rice-wheat cropping system. The experiment was laid out in split plot design with three replications. In main plots, five rice residue management treatments viz., no rice residue, rice residue 5 t·ha-1 (surface), rice residue 6 t·ha-1 (surface), rice residue 7 t·ha-1 (surface) and rice residue 5 t·ha-1 (incorporation) were settled and in sub plots, four weed control treatments i.e. clodinafop 60 t·ha-1, sulfosulfuron 25 t·ha-1, mesosulfuron + iodosulfuron 12 t·ha-1 and control (unweeded) were arranged. Results of the study revealed that surface application as well as incorporation of rice residues improved the organic carbon and NPK status than no rice residues. Among the residue management practices, incorporation of rice residues 5 t·ha-1 significantly improved the soil organic carbon, available nitrogen, phosphorus and potassium than no rice residue treatment in the 0 - 15 soil layer during both the years. Same trend was observed for 15 - 30 cm soil layer but differences were less wide than 0 - 15 cm soil layer. Among the weed control treatments, organic carbon was not significantly influenced. Herbicide treated plots registered significantly higher available nitrogen, phosphorus and potassium than control (unweeded) treatment in the 0 - 15 cm soil layer during both the years.
文摘The thermodynamic properties of dibenzofurans (DFs), xanthones (XTs) and an-thraquinones (AQs) with one and two positions substituted with hydroxyls in the ideal gas state at 298.15 K and 1.013×10^5 pa were calculated at the B3LYP/6-311G^* level using Gaussian 03 program. The isodesmic reactions were designed to calculate the standard free energy of formation (△fG^θ). Three types of hydrogen bonds exist in the three kinds of chemicals and their bond energies were ascertained as 7-15, 15-23 and 49-58 kJ·mo1^-1 respectively by comparing the △fG^θ values. Electronic density topology analysis was applied to validate the strength of bond.
基金Supported by the National Natural Science Foundation of China under Grant Nos 11374066 and 11374068the High-Level Personnel Training Project in Guangdong Provincethe Natural Science Foundation of Guangdong Province under Grant No S2012020010885
文摘We investigate the influence of coating layer on acoustic wave propagation in a dispersed random medium consisting of coa.ted fibers.In the strong-scattering regime, the characteristics of wave scattering resonances are found to evolve regularly with the properties of the coating layer.By theoretical calculation,frequency gaps are found in acoustic excitation spectra in a random medium.The scattering cross section results present the evolution of scattering resonances with the properties of the coating layer,which offers a good explanation for the change of the frequency gaps.The velocity of the propagation quasi-mode is also shown to depend on the filling fraction of the coating layer.We use the generalized coherent potential-approximation approach to solve acoustic wave dispersion relations in a complicated random medium consisting of coating-structure scatterers.It is shown that our model reveals subtle changes in the behavior of the acoustic wave propagating quasi-modes.
基金supported by the National Natural Science Foundation of China (Grant No. 10674032)
文摘The complete band gaps (CBGs) of shallow water waves propagating over bottoms with periodically drilled holes are investigated numerically by the plane wave expansion method. Four different patterns are considered, containing triangular, square, hexagonal and circular cross-sectioned holes arranged into triangular lattices. Results show that the width of CBGs can be changed by adjusting the orientation of noncircular holes and the effect of hole shape on the width of the maximal CBGs is discussed.
基金Supported by the National Natural Science Foundation of China under Grant No 10674032, and the Natural Science Foundation of Guangdong Province under Grant Nos 032485 and 6021480.
文摘We present the acoustic band gaps (ABGs) for a geometry of three-dimensional complex acoustic crystals: the NaCl-type structure. By using the super cell method based on the plane-wave expansion method (PWE), we study the three configurations formed by water objects (either a sphere of different sizes or a cube) located at the vertices of simple cubic (SC) lattice and surrounded by mercury background. The numerical results show that ABGs larger than the original SC structure for all the three configurations can be obtained by adjusting the length-diameter ratio of adjacent objects but keeping the filling fraction (f = 0.25) of the unit cell unchanged. We also compare our results with that of 3D solid composites and find that the ABGs in liquid composites are insensitive to the shapes as that in the solid composites. We further prove that the decrease of the translation group symmetry is more efficient in creating the ABGs in 3D water-mercury systems.
基金Supported by National Natural Science Foundation of China under Grant No.10675108Foundation of Yancheng Institute of Technology under Grant No.XKR2010007
文摘Neural tube development comprises neural induction, neural epithelial cell proliferation, and apoptosis, as well as migration of nerve cells. Too much or too little apoptosis leads to abnormal nervous system development. The present study analyzed expression and distribution of apoptotic-related factors, including Fas, FasL, and caspase-3, during human embryonic neural tube development. Experimental results showed that increased caspase-3 expression promoted neural apoptosis via a mitochondrial-mediated intrinsic pathway at 4 weeks during early human embryonic neural tube development. Subsequently, Fas and FasL expression increased during embryonic development. The results suggest that neural cells influence neural apoptosis through synergistic effects of extrinsic pathways. Therefore, neural apoptosis during the early period of neural tube development in the human embryo might be regulated by the death receptor induced apoptotic extrinsic pathways.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11104083 and 10934011)
文摘We investigate the nonlinear modes in a rotating double well potential with 79T symmetry. Focus on the existence and stability of the nonlinear PT modes in this system, we found that five types of PT modes can stably exist by given certain parameter settings. The multistable area between these modes are studied numerically and the bistable and tristable areas are delimited. With different input trial wavefunctions, five types of solitary wave modes are identified. We found that the rotating of the potential can significantly affect the power flow of the fundamental harmonic mode, whose effect is absent for the other modes.
基金by the National Natural Science Foundation of China under Grant No.10675108the Foundation of Yancheng Institute of Technology under Grant No XKR2010007.
文摘A finite temperature phase diagram of the rotating Bose–Hubbard model,including the crossover between Mott insulator and the normal state,is derived on the frame of the Gutzwiller mean-field theory.In addition,we calculate the critical temperature of superfluid-normal phase transition.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11327404 and U1432118)the Natural Science Research Programme of Education Department of Anhui Province,China(Grant Nos.KJ2013A260 and KJ2016A749)
文摘The relativistic and distorted wave effects are investigated for the electron momentum distributions of Xe 4d electrons.The theoretical results show good agreements with the experimental data measured previously with electron momentum spectroscopy. The distorted wave effect and the relativistic effect are found to play important roles in the low and high momentum regions, respectively.
基金the National Natural Science Foundation of China(Grant Nos.12175001 and 12075001).
文摘Entanglement,quantum steering and Bell nonlocality can be used to describe the distinct quantum correlations of quantum systems.Because of their different characteristics and application fields,how to divide them quantitatively and accurately becomes particularly important.Based on the sufficient and necessary criterion for quantum steering of an arbitrary two-qubit T-state,we derive the inequality relations between quantum steering and entanglement as well as between quantum steering and Bell nonlocality for the T-state.Additionally,we have verified those relations experimentally.
文摘Background:Since 2010,two versions of National Guidelines aimed at promoting the management of ST-segment elevation myocardial infarction (STEMI) have been formulated by the Chinese Society of Cardiology.However,little is known about the changes in clinical characteristics,management,and in-hospital outcomes in rural areas.Methods:In the present multicenter,cross-sectional study,participants were enrolled from rural hospitals located in Liaoning province in Northeast China,during two different periods (from June 2009 to June 2010 and from January 2015 to December 2015).Data collection was conducted using a standardized questionnaire.In total,607 and 637 STEMI patients were recruited in the 2010 and 2015 cohorts,respectively.Results:STEMI patients in rural hospitals were older in the second group (63 years vs.65 years,P =0.039).We found increases in the prevalence of hypertension,prior percutaneous coronary intervention (PCI),and prior stroke.Over the past 5 years,the cost during hospitalization almost doubled.The proportion of STEMI patients who underwent emergency reperfusion had significantly increased from 42.34% to 54.47% (P 〈 0.0001).Concurrently,the proportion of primary PCI increased from 3.62% to 10.52% (P 〈 0.0001).The past 5 years have also seen marked increases in the use of guideline-recommended drugs and clinical examinations.However,in-hospital mortality and major adverse cardiac events did not significantly change over time (13.01% vs.10.20%,P =0.121;13.34% vs.13.66%,P =0.872).Conclusions:Despite the great progress that has been made in guideline-recommended therapies,in-hospital outcomes among rural STEMI patients have not significantly improved.Therefore,there is still substantial room for improvement in the quality of care.
基金Y.L.acknowledges the supports of the National Natural Science Foundation of China(Grant Nos.11874112 and 11905032)the Key Research Projects of General Colleges in Guangdong Province through grant No.2019KZDXM001+1 种基金the Foundation for Distinguished Young Talents in Higher Education of Guangdong through grant No.2018KQNCX279The work of BAM on this topic was supported,in part,by grant No.1286/17 from the Israel Science Foundation.
文摘This brief review summarizes recent theoretical and experimental results which predict and establish the existence of quantum droplets(QDs),i.e.,robust two-and three-dimensional(2D and 3D)self-trapped states in Bose-Einstein condensates(BECs),which are stabilized by effective self-repulsion induced by quantum fluctuations around the mean-field(MF)states[alias the Lee-Huang-Yang(LHY)effect].The basic models are presented,taking special care of the dimension crossover,2D→3D.Recently reported experimental results,which exhibit stable 3D and quasi-2D QDs in binary BECs,with the inter-component attraction slightly exceeding the MF self-repulsion in each component,and in single-component condensates of atoms carrying permanent magnetic moments,are presented in some detail.The summary of theoretical results is focused,chiefly,on 3D and quasi-2D QDs with embedded vorticity,as the possibility to stabilize such states is a remarkable prediction.Stable vortex states are presented both for QDs in free space,and for singular but physically relevant 2D modes pulled to the center by the inverse-square potential,with the quantum collapse suppressed by the LHY effect.
基金Supported by Science Development Foundation of Tianjin Institute of Education(No.20070301)Tianjin Natural Science Foundation of China(No.11JCYBJC13400)
文摘Objective: To investigate the protective effects of sodium tanshinone B (STB) on brain damage following focal ischemiareperfusion (I/R) injury through interfering with NmethyIDaspartic acid receptor (NMDAR) and excitatory and inhibitory amino acids, and evaluate the potential mechanisms of the neuroprotective activity of STB. Methods: Transient forebrain ischemia was induced by middle cerebral artery occlusion (MCAO). The rats were randomized into a sham operated group, a model group (I/R) and three STB different dose groups. Rats were pretreated with STB at the doses of 4, 8, 16 mg/kg (STB1, STB2, STB3) for 3 days before MCAO. The expression of NMDAR1 was detected by immunohistochemistry and Western blotting. The concentrations of glutamate and λaminobutyric acid (GABA) were analyzed using high performance liquid chromatography. Results: STB treatment reduced neurological defect scores, cerebral infarction volume and brain water content. The levels of NMDAR1 were significantly higher in the I/R and STB1 groups than that of the sham and the STBs groups (P〈0.01). Optical density of NMDAR1 was significantly increased in cornu ammonis (CA)I region of the I/R group (P〈0.05). STB treatment reduced NMDAR1 optical density in the CA1 region (P〈0.01). The levels of glutamate were significantly lower in the hippocampus in the STB3 group than that of the I/R, STB1 and STB2 groups (P〈0.01). Conclusion: Preconditioning with STB appears to be a simple and promising strategy to reduce or even prevent cerebral I/R injury and has potential for future clinical application.