13 results on '"Pan CD"'
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2. A threefold interpenetrating two-dimensional zinc(II) coordination polymer: synthesis, crystal structure and selective luminescence sensing properties.
- Author
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Pan CD, Wang J, Xu JQ, Zhang KF, and Wang XW
- Abstract
The Fe
3+ ion is the most important element in environmental systems and plays a fundamental role in biological processes. Iron deficiency can result in diseases and highly selective and sensitive detection of trace Fe3+ has become a hot topic. A novel two-dimensional ZnII coordination framework, poly[[μ-4,4'-bis(2-methylimidazol-1-yl)diphenyl ether-κ2 N3 :N3' ](μ-4,4'-sulfonyldibenzoato-κ2 O:O')zinc(II)], [Zn(C14 H8 O6 S)(C20 H18 N4 O)]n or [Zn(SDBA)(BMIOPE)]n , (I), where H2 SDBA is 4,4'-sulfonyldibenzoic acid and BMIOPE is 4,4'-bis(2-methylimidazol-1-yl)diphenyl ether, has been prepared and characterized by IR, elemental analysis, thermal analysis and X-ray diffraction analysis, the latter showing that the coordination polymer exhibits a threefold interpenetrating two-dimensional 44 -sql network. In addition, it displays a highly selective and sensitive sensing for Fe3+ ions in aqueous solution.- Published
- 2019
- Full Text
- View/download PDF
3. COMT Val158Met polymorphism and Parkinson's disease risk: a pooled analysis in different populations.
- Author
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Wang YC, Zou YB, Xiao J, Pan CD, Jiang SD, Zheng ZJ, Yan ZR, Tang KY, Tan LM, and Tang MS
- Subjects
- Databases, Bibliographic statistics & numerical data, Female, Humans, Male, Methionine genetics, Parkinson Disease epidemiology, Parkinson Disease etiology, Valine genetics, Catechol O-Methyltransferase genetics, Genetic Predisposition to Disease, Global Health, Parkinson Disease ethnology, Parkinson Disease genetics, Polymorphism, Single Nucleotide
- Abstract
Objective: Many studies have analyzed the association between the catechol-O-methyltransferase (COMT) Val158Met polymorphism and Parkinson's disease (PD), which yield inconsistent results. This meta-analysis was designed to determine the possible association between the COMT Val158Met polymorphism and the risk of PD in different populations., Methods: The PubMed, Springer Link, Ovid, Chinese Wanfang Data Knowledge Service Platform, Chinese National Knowledge Infrastructure and Chinese Biology Medicine databases were used for literature searching up to May 2018. The association between the COMT Val158Met polymorphism and the risk of PD was evaluated by calculating the pooled odds ratio (OR) and 95% confidence intervals (CIs)., Results: A total of 27 studies including 10,239 PD patients and 15,538 controls were screened out. In the overall population, COMT Val158Met polymorphism was not significantly associated with the risk of PD. In the subgroup analysis stratified by ethnicity, a significant association between COMT Val158Met polymorphism and PD risk was detected in Japan (LL vs. HH: OR = 1.48, 95% CI = 1.04-2.11; LL vs. HH+HL: OR = 1.54, 95% CI = 1.10-2.15) and India (LL+HL vs. HH: OR = 1.48, 95% CI = 1.14-1.91)., Conclusion: This study indicated a significantly closer association between COMT Val158Met polymorphism and PD in the Japanese and Indian populations compared with other ethnicities. Ethnicity seems to play an important role in the genetic association of PD.
- Published
- 2019
- Full Text
- View/download PDF
4. Plasmon-enhanced fluorescence of submonolayer porphyrins by silver-polymer core-shell nanoparticles.
- Author
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Niu JX, Pan CD, Liu YT, Lou ST, Wu E, Wu BT, Zhang XL, and Jin QY
- Abstract
We investigate the fluorescence from submonolayer porphyrin molecules near silver-polymer core-shell nanoparticles (NPs) at a well-controlled separation distance of about 1 nm - 5 nm. When porphyrin molecules are deposited on silver NPs with the plasmonic resonance peak at about 410 nm, which matches very closely with the 405-nm excitation laser and the absorption band of porphyrin molecules, their emission intensity is found to be enhanced due to the plasmonic resonant excitation enhancement, and shows a decline as the increasing polymer shell thickness. Meanwhile, the lifetime results demonstrate that there exists the fluorescence quenching due to the charge transfer and nonradiative energy transfer losses, which is also the main reason that the maximum enhancement factor obtained in experiment is only about 2.3, although the theoretical one is above 60 according to the electric field distribution near silver NPs calculated by finite-difference time-domain method.
- Published
- 2018
- Full Text
- View/download PDF
5. Hospital-Based Study of the Frequency and Risk Factors of Stroke Recurrence in Two Years in China.
- Author
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He Q, Wu C, Guo W, Wang ZY, Zhao YF, Lu J, Qin YY, Guo YB, Qin YC, Pan CD, and He J
- Subjects
- Adult, Aged, Cerebral Hemorrhage etiology, Cerebral Infarction, China epidemiology, Female, Humans, Longitudinal Studies, Male, Middle Aged, Recurrence, Retrospective Studies, Risk Factors, Hospitals statistics & numerical data, Stroke complications, Stroke epidemiology
- Abstract
Background: Stroke causes death and disability throughout the world and recurrent stroke events are more likely to be disabling or fatal. We conducted a hospital-based study to investigate the frequency and influence factors of stroke recurrence in China., Methods: Data from patients hospitalized with stroke between January 2007 and December 2010 of 109 tertiary hospitals in China were used. Stroke recurrence and associated factors were ascertained. The zero-inflated model was used to evaluate the factors of recurrence., Results: Of 101,926 discharged patients, the cumulative 2-year stroke recurrence rate was 3.80% for subarachnoid hemorrhage (SAH), 5.31% for intracerebral hemorrhage (ICH), and 8.71% for ischemic stroke (IS), respectively. Among patients with stroke recurrence, 54.11% with SAH, 60.42% with ICH, and 92.92% with IS relapsed for the same type of the first-onset stroke. For discharged patients with SAH with middle cerebral artery aneurysm clipping or artery aneurysm embolization, it was less likely to stroke relapse, but the times of recurrence would increase if 1 recurrence appeared. Cerebral artery aneurysms and hypertension were risk factors for recurrence frequency. For ICH, protective factors for recurrence were trepanation and drainage of intracranial hematoma, cerebral angiography, puncture and drainage of intracranial hematoma, and length of stay (LOS). But rheumatic heart disease and atrial fibrillation would further the relapse frequency. For IS, age and LOS were protective factors, but recurrence frequency would increase if the first recurrence happened. Cervical spondylopathy, male gender, and diabetes were risk factors for frequency of relapse., Conclusions: Associated factors were different for recurrence frequency among different stroke types., (Copyright © 2017 National Stroke Association. Published by Elsevier Inc. All rights reserved.)
- Published
- 2017
- Full Text
- View/download PDF
6. Seasonal Dynamics of Metabolites in Needles of Taxus wallichiana var. mairei.
- Author
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Yang L, Zheng ZS, Cheng F, Ruan X, Jiang DA, Pan CD, and Wang Q
- Subjects
- Chromatography, High Pressure Liquid methods, Metabolomics methods, Plant Extracts analysis, Plant Extracts chemistry, Plant Leaves chemistry, Seasons, Flavones analysis, Polysaccharides analysis, Taxoids analysis, Taxus chemistry
- Abstract
Seasonal variations of the phytochemicals contents in needles of T. wallichiana var. mairei due to the effects of growth meteorological parameters were investigated in this study. The needles of T. wallichiana var. mairei were collected from different months and the contents of taxoids (paclitaxel, 10-deacetylbaccatin III (10-DAB), baccatin III, cephalomannine, 10-deacetyltaxol (10-DAT)), flavones (ginkgetin, amentoflavone, quercetin) and polysaccharides were quantified by ultra performance liquid chromatography (UPLC) and the resonance light scattering (RIL) method. The content of taxoids gave the highest level of 1.77 ± 0.38 mg·g
-1 in January, and the lowest value of 0.61 ± 0.08 mg·g-1 in September. Unlike taxoids, the content of flavonoids was the highest in August. The content of polysaccharides reached peak value of 28.52 ± 0.57 mg·g-1 in September, which was two times higher than the lowest content of 9.39 ± 0.17 mg·g-1 in January. The contents of paclitaxel, 10-DAB, 10-DAT and polysaccharides significantly depended on meteorological parameters. The mean of minimum temperature (R = -0.61) and length of daylight (R = -0.60) were significantly correlated to 10-DAB content, while 10-DAT level showed significant correlation with length of daylight (R = -0.70) and relative humidity (R = 0.70). In addition, temperature had significantly negative effect on the content of paclitaxel and a significantly positive effect on that of polysaccharides. This study enriched the knowledge on the accumulation pattern of metabolites and could help us to determine the collecting time of T. wallichiana var. mairei for medicinal use.- Published
- 2016
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7. Effects of climate warming on plant autotoxicity in forest evolution: a case simulation analysis for Picea schrenkiana regeneration.
- Author
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Ruan X, Pan CD, Liu R, Li ZH, Li SL, Jiang DA, Zhang JC, Wang G, Zhao YX, and Wang Q
- Abstract
In order to explore how plant autotoxicity changes with climate warming, the autotoxicity of P. schrenkiana needles' water extract, organic extract fractions, and key allelochemical DHAP was systemically investigated at the temperature rising 2 and 4°C based on the data-monitored soil temperature during the last decade in the stage of Schrenk spruce regeneration (seed germination and seedling growth). The results showed that the criterion day and night temperatures were 12°C and 4°C for seed germination, and 14°C and 6°C for seedling growth, respectively. In the presence of water extract, the temperature rise of 2°C significantly inhibited the germination vigor and rate of P. Schrenkiana seed, and a temperature rise of 4°C significantly increased the inhibition to the seedling growth (P < 0.05). Among the three organic fractions, the low-polar fraction showed to be more phytotoxic than the other two fractions, causing significant inhibitory effects on the seed germination and growth even at low concentration of 0.1 mg/mL, and the inhibition effect was enhanced as temperature increased. The temperature rise significantly enhanced the promotion effect of DHAP, while the inhibition effect of temperature rise became less important with increasing concentration of DHAP. This investigation revealed that autotoxicity of P. schrenkiana was affected by the climate warming. As expected, it provided an insight into the mechanism and effectiveness of allelopathy in bridging the causal relationship between forest evolution and climate warming.
- Published
- 2016
- Full Text
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8. Enantioselective Separation of 4,8-DHT and Phytotoxicity of the Enantiomers on Various Plant Species.
- Author
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Yang L, Ma XY, Ruan X, Jiang DA, Pan CD, and Wang Q
- Subjects
- Cucumis sativus drug effects, Cucumis sativus growth & development, Germination drug effects, Herbicides isolation & purification, Lactuca drug effects, Lactuca growth & development, Onions drug effects, Onions growth & development, Raphanus drug effects, Raphanus growth & development, Seedlings drug effects, Stereoisomerism, Tetralones isolation & purification, Triticum drug effects, Triticum growth & development, Coccidia chemistry, Crops, Agricultural drug effects, Crops, Agricultural growth & development, Herbicides toxicity, Tetralones toxicity
- Abstract
As a candidate for bioherbicide, 4,8-dihydroxy-1-tetralone (4,8-DHT) was isolated from Caryospora callicarpa epicarp and its two enantiomers, S-(+)-isosclerone and R-(-)-regiolone, were separated by chiral high-performance liquid chromatography (HPLC) on a Chiralcel OD column with chiral stationary phase (CSP)-coated cellulose-tris(3,5-dimethylphenylcarbamate). Then, the phytotoxicity of 4,8-DHT and its enantiomers toward the seeds germination and seedling growth of the five tested plant species, including lettuce (Latuca sativa), radish (Raphanus sativus), cucumber (Cucumis sativus), onion (Allium cepa), and wheat (Triticum aestivum), were investigated and the results indicated a hormesis at low concentration of 4,8-DHT and its enantiomers, but a retardant effect at high concentration. Between the two enantiomers of 4,8-DHT, the S-(+)-isosclerone was more toxic to seeds germination and seedling growth of the five tested plant species than the R-(-)-regiolone, and also the phytotoxicity of S-(+)-isosclerone varied with different plants. For example, S-(+)-isosclerone was the most active to seedling growth of lettuce, indicating that S-(+)-isosclerone had specific effects on different organisms. Thus, all of the chirality and concentration of 4,8-DHT, as well as the affected plant species, need to be taken into consideration in the development and utilization of 4,8-DHT.
- Published
- 2016
- Full Text
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9. [Models for estimating foliar Fe and Mn Concentration of Armeniaca vulgaris cv. Luntaibaixing using spectral reflectance].
- Author
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Hu ZZ, Pan CD, Wang SW, Guo ZC, Wang QT, Ding F, and Li Y
- Subjects
- Fruit, Linear Models, Models, Theoretical, Soil, Spectrum Analysis, Iron chemistry, Manganese analysis, Plant Leaves chemistry, Rosaceae chemistry
- Abstract
Aimed at providing technology for a rapid nutrition diagnosis system of micronutrients in Armeniaca vulgaris cv. Luntaibaixing, we established an element concentration estimation model for its foliar ferrum (Fe) and manganese (Mn) concentration based on spectrum analysis. The foliar spectrum reflectance at various phenological periods of fruit development under different soil fertility conditions was measured by Unispec-SC spectrometer. By analyzing the correlation of foliar Fe, Mn concentration at various phenological periods of fruit development, the spectrum reflectance Rλ and its first-order differential f' (Rλ), we filtered out its sensitive bands. And we established an element concentration estimation model for its foliar Fe and Mn at various phenological periods of fruit development with the linear regression model. The results showed that the spectral sensitive bands of foliar Fe in fruit setting period were 873 and 874 nm, 375 and 437 nm in fruit core-hardening period, 836 and 837 nm in maturity period and 325 and 1 054 nm in post-harvest period. However, the spectral sensitive bands of Mn were 913 and 1 129 nm, 425 and 970 nm, 390 and 466 nm, 423 and 424 nm, respectively. The Fe and Mn concentration of A. vulgaris cv. Luntaibaixing leaves were the most relevant to the first-order differential f' (RD) of its spectrum reflectance, whose linear spectrum estimation model fitting degree was the highest and reached to a significant or highly significant level. It showed that the spectral sensitive bands of Fe and Mn element varied with different phenological periods of fruit development. The spectrum estimation models for its foliar Fe and Mn concentration could be established with linear model according to its first-order differential f' (Rλ).
- Published
- 2014
10. [Root system spatial distribution of different aged Armeniaca vulgaris cv. Luntaibaixing in arid oasis under irrigation].
- Author
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Wang SW and Pan CD
- Subjects
- China, Forestry methods, Plant Roots anatomy & histology, Time Factors, Agricultural Irrigation, Desert Climate, Plant Roots growth & development, Prunus growth & development
- Abstract
By the methods of layered digging and image scanning analysis, this paper studied the root system spatial distribution of different aged Armeniaca vulgaris cv. Luntaibaixing in arid oasis under irrigation. The root system of A. vulgaris cv. Luntaibaixing was mainly constituted by fine roots (d < or = 1 mm), while medium roots (1
2 mm) only had a small proportion. For the trees aged 5-year old, 10-year old, and 15-year old, the percentage of fine root length in the total root length was 90.9%, 88.4%, and 79.9% respectively, the root length density increased with tree age, and the length density of the roots with different diameter classes was 15-year old>10-year old>5-year old. In vertical direction, the root length density decreased after an initial decrease, and the root dry mass density had a significant difference between soil layers. The intensive distribution region of the root biomass density for the trees aged 5-year old, 10-year old, and 15-year old was 30-80 cm, 30-100 cm, and 30-100 cm soil depth within the 200 cm range from the trees, respectively. In horizontal direction, the root dry mass density at different distances from the trees had significant difference, i. e., the farther the distance from the tree trunk, the smaller the root dry mass density. In order to decrease the overlap between the tree line and to reduce water and nutrient competition, the row ledge of A. vulgaris cv. Luntaibaixing in arid oasis under irrigation should not be less than 6 m. - Published
- 2012
11. Autotoxicity and allelopathy of 3,4-dihydroxyacetophenone isolated from Picea schrenkiana needles.
- Author
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Ruan X, Li ZH, Wang Q, Pan CD, Jiang DA, and Wang GG
- Subjects
- Acetophenones isolation & purification, Acetophenones pharmacology, Crystallography, X-Ray, Cucumis sativus drug effects, Cucumis sativus growth & development, Fabaceae drug effects, Fabaceae growth & development, Lactuca drug effects, Lactuca growth & development, Oryza drug effects, Oryza growth & development, Plant Extracts pharmacology, Plant Leaves chemistry, Plant Roots growth & development, Raphanus drug effects, Raphanus growth & development, Soil analysis, Triticum drug effects, Triticum growth & development, Acetophenones toxicity, Germination drug effects, Picea chemistry, Plant Extracts toxicity, Plant Roots drug effects
- Abstract
Bioassay-guided fractionation of the diethyl ether fraction of a water extract of Picea schrenkiana needles led to the isolation of the phenolic compound 3,4-dihydroxy- acetophenone (DHAP). The allelopathic effects of DHAP were evaluated under laboratory conditions on P. schrenkiana, rice (Oryza sativa L.), wheat (Triticum aestivum L.), radish (Raphanus sativus L.), lettuce (Latuca sativa L.), cucumber (Cucumis sativus L.) and mung bean (Phaseolus radiatus L.). DHAP significantly inhibited seed germination and seedling growth of P. schrenkiana at concentrations of 2.5 mM and 0.5 mM (p < 0.05). Soil analysis revealed that P. schrenkiana forest soils contained exceptionally high DHAP concentrations (mean = 0.51 ± 0.03 mg/g dry soil), sufficient to inhibit natural P. schrenkiana recruitment. DHAP also exhibited strong allelopathic potential. It significantly inhibited wheat and lettuce seed germination at concentrations of 1 mM and 0.5 mM (p < 0.05). The active compound also completely inhibited root growth of the six test species at high concentrations. Our results suggest a dual role of DHAP, both as an allelochemical and as an autotoxicant. The potential for a single plant needle-leached compound to influence both inter- and intra-specific interactions emphasized the complex effects that plant secondary metabolites might have on plant population and community structure.
- Published
- 2011
- Full Text
- View/download PDF
12. Phenolics and plant allelopathy.
- Author
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Li ZH, Wang Q, Ruan X, Pan CD, and Jiang DA
- Subjects
- Centaurea growth & development, Herbicides metabolism, Catechin metabolism, Centaurea metabolism, Ecosystem, Oxyquinoline metabolism, Phenols metabolism
- Abstract
Phenolic compounds arise from the shikimic and acetic acid (polyketide) metabolic pathways in plants. They are but one category of the many secondary metabolites implicated in plant allelopathy. Phenolic allelochemicals have been observed in both natural and managed ecosystems, where they cause a number of ecological and economic problems, such as declines in crop yield due to soil sickness, regeneration failure of natural forests, and replanting problems in orchards. Phenolic allelochemical structures and modes of action are diverse and may offer potential lead compounds for the development of future herbicides or pesticides. This article reviews allelopathic effects, analysis methods, and allelopathic mechanisms underlying the activity of plant phenolic compounds. Additionally, the currently debated topic in plant allelopathy of whether catechin and 8-hydroxyquinoline play an important role in Centaurea maculata and Centaurea diffusa invasion success is discussed. Overall, the main purpose of this review is to highlight the allelopacthic potential of phenolic compounds to provide us with methods to solve various ecology problems, especially in regard to the sustainable development of agriculture, forestry, nature resources and environment conservation.
- Published
- 2010
- Full Text
- View/download PDF
13. [An epidemiological study on sexual transmission of human immunodeficiency virus among pre-marital group in Yining city, Xinjiang].
- Author
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Mao YR, Zheng XW, Re ZY, Pan CD, Guli RZ, Song JQ, Yang LM, and Zhang GY
- Subjects
- Blotting, Western, China epidemiology, Enzyme-Linked Immunosorbent Assay, Female, HIV Infections immunology, Humans, Incidence, Male, Proportional Hazards Models, Sexual Behavior, Sexually Transmitted Diseases, Viral immunology, HIV immunology, HIV Infections epidemiology, Sexually Transmitted Diseases, Viral epidemiology
- Abstract
Objective: To study the human immunodeficiency virus (HIV) status through heterosexual transmission in Yining city and to provide information on effective intervention measures., Methods: Cohort of HIV sero-discordant couples identified from 1997 to 2000 was formed. Proportional risk model was used to analyze the time of HIV sero-conversion and the related factors. All the recruiters were under informed consent., Results: Through following on 22 sero-discordant couples, we found that the incidence density (ID) of HIV sero-conversion was 32.49/100 person-year (PY) with 33.74/100 PY for women. In the proportional hazard model, the course of sero-conversion was only 2.43 years and the frequency of sexual contact was statistically significant (>or= 3 times/week vs. < 3 time/week: RR = 1.984, 95% CI: 1.045 - 3.767), indicating this factor was related to the hazard of HIV sero-conversion. However, the viral load of HIV infections has no such effect on HIV sero-conversion of their spouses. In addition, the ratio of CD4(+)/CD8(+) was lower in spouses of HIV sero-conversion than that in spouses of HIV non-sero conversion (t test: t = 4.77, P < 0.01)., Conclusion: In order to control HIV transmission among general population, we suggested that HIV/AIDS counseling and testing be developed for pre-marital people in the region with high HIV prevalence.
- Published
- 2004
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