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1.
Ying Yong Sheng Tai Xue Bao ; 31(11): 3833-3841, 2020 Nov.
Artigo em Chinês | MEDLINE | ID: mdl-33300734

RESUMO

Quantitative assessment of hydrological connectivity is a hot but difficult issue in current research. Using the 30-m resolution global monthly surface water remote sensing dataset released by the EU Joint Research Center and three indicators of geostatistical connectivity, maximum distance of connection (MDC), and surface water extent of connectome (i.e., seasonally connected water bodies), we quantified the hydrological connectivity of surface water in Momoge National Nature Reserve in different months of a normal year (May to October 2016), and in September of different hydrological years (a wet year, namely 1998; a normal year, namely 2016; a drought year, namely 2002), and different directions (west-east and north-south). Our results showed that: 1) the geostatistical connectivity function (GCF) along the west-east direction was better than that along the north-south direction. The GCF in August and July was better than that in other months. The GCF along the west-east direction of each hydrological year was better than that in the drought year, whereas the GCF in the drought year was better than the corresponding value in the normal year. The GCF along the north-south direction in each hydrological year was better than that in the normal year, whereas the GCF in the normal year was better than that in the drought year. The MDC along the west-east direction in June, July, September, and October of the normal year was all concentrated at 25.26 km. MDC was more concentrated along the north-south direction, with 10 km for all months. The MDC in the normal and drought years was relatively close, but both were much smaller than that in the wet year. 2) frequent seasonal connections between the Yuelianghu Reservoir and the Nenjiang River, and between Etoupao and its neighboring lakes occurred in the study area during the normal year, while most of the other lakes remained isolated. The patterns of hydrological connection in the study area differed across different hydrological years: two giant connectomes were formed in the wet year, some lakes are periodically connected in the normal year, and all lakes remain isolated in the drought year. 3) As a drainage area for farmland receding water, the surface water extent of the Etoupao connectome increased visibly during the three water supplement seasons (spring, summer, and autumn). By quantifying the surface hydrological connectivity in Momoge National Nature Reserve with multiple water sources from different perspectives, our results provide a scientific basis for wetland protection and restoration and integrated management of watershed water resources.

2.
Oncol Lett ; 5(3): 749-755, 2013 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-23426528

RESUMO

SMC1A (structural maintenance of chromosomes 1A), which encodes a structural subunit of the cohesin protein complex, is necessary for the process of sister chromatid cohesion during the cell cycle. Mutation and deregulation of SMC1A are highly relevant to diverse human diseases, including Cornelia de Lange syndrome and malignant carcinomas. In order to further investigate the role of SMC1A in the oncogenesis of lung cancer, SMC1A-specific short hairpin RNA (shRNA)-expressing lentivirus (Lv-shSMC1A) was constructed and used to infect A549 and H1299 cells. SMC1A mRNA and protein expression levels were downregulated in A549 and H1299 cells as demonstrated by real-time PCR and western blot assays. We found that SMC1A inhibition resulted in significantly impaired proliferation and colony formation as well as reduced invasiveness of tumor cells. Notably, Lv-shSMC1A-infected cancer cells exhibited a greater proportion of cells in the G0/G1 phase, but a lower proportion of S phase cells, compared to the parent or Lv-shCon infected cancer cells. Moreover, a greater proportion of sub-G1 apoptotic cells was observed in Lv-shSMC1A-infected cells. These results suggest that SMC1A is a novel proliferation regulator that promotes the growth of lung cancer cells, and that down-regulation of SMC1A expression induces growth suppression of A549 and H1299 cells via G1/S cell cycle phase arrest and apoptosis pathways. Therefore, SMC1A may serve as a new molecular target for lung cancer therapy.

3.
Guang Pu Xue Yu Guang Pu Fen Xi ; 32(7): 1744-7, 2012 Jul.
Artigo em Chinês | MEDLINE | ID: mdl-23016316

RESUMO

The present article measured the absorption coefficient spectra and refractive index spectra of nitrofurantoin original drug, which is one kind of nitrofuran drugs, in the terahertz frequency range from 0.2 to 1.8 THz using terahertz time-domain spectroscopy. The results showed that there exist a number of characteristic absorption peaks of nitrofurantoin with different intensity in the range and the absorption coefficient spectra can be used to identify nitrofurantoin. The article also simulated absorption coefficient spectra of nitrofurantoin molecule within 0.2 - 1.8 THz using density functional theory by Gaussian software, and vibrational modes of some peaks in the experimental absorption coefficient spectra were analyzed and identified. The results show that the experimental absorption peaks at 1.25 and 1.60 THz correspond with the theoretical peaks at 1.30 and 1.67 THz, and these experimental peaks were caused by intramolecular vibrational modes of nitrofurantoin.


Assuntos
Nitrofurantoína/análise , Espectroscopia Terahertz , Refratometria , Vibração
4.
Guang Pu Xue Yu Guang Pu Fen Xi ; 32(5): 1170-4, 2012 May.
Artigo em Chinês | MEDLINE | ID: mdl-22827047

RESUMO

Frequency-dependent absorption coefficient spectrum and refractive index spectrum of alpha endosulfan, a kind of persistent organic pollutants, are presented in the terahertz frequency region by terahertz (THz) time-domain spectroscopy (TDS). The spectral features in the THz region have a number of unique characteristic absorption peaks. The result demonstrates that THz-TDS is a promising method to identify materials. Then we adopted density functional calculation method to analyze theoretic absorption coefficients of single alpha endosulfan molecule within 0.2-2 THz. The results show that absorption peaks at 1.68, 1.91 THz in theoretical calculation correspond to 1.7, 1.88 THz in the experiment. Finally, vibrational modes and approximate assignments were discussed, showing that these matched peaks are caused by intramolecular vibrational modes of alpha endosulfan. Others might be related to intermolecular vibrational modes or combined vibrational modes.

5.
Guang Pu Xue Yu Guang Pu Fen Xi ; 31(3): 600-3, 2011 Mar.
Artigo em Chinês | MEDLINE | ID: mdl-21595199

RESUMO

The terahertz spectra of Ractopamine hydrochloride in the range of 0.2 to 2.2 THz was obtained by THz time-domain spectroscopy, and the absorption and refraction spectra of Ractopamine hydrochloride was got meanwhile. The structure and vibrational frequencies of Ractopamine molecule in the THz range were simulated by density functional theory. The difference between experimental and theoretical results was analyzed. And assisted by Gaussian View 3.09, the origin of the vibrational frequencies was recognized. The results show that besides the intramolecular vibrations, THz absorption of Ractopamine hydrochloride originated from the intermolecular hydrogen bond network and Van der Waals force between molecules. This study demonstrated the feasibility of time-domain terahertz spectroscopy for the identification of Ractopamine hydrochloride and provided a new way for the detection of Ractopamine hydrochloride.


Assuntos
Fenetilaminas/análise , Espectroscopia Terahertz/métodos
6.
Guang Pu Xue Yu Guang Pu Fen Xi ; 31(10): 2629-33, 2011 Oct.
Artigo em Chinês | MEDLINE | ID: mdl-22250522

RESUMO

The optical properties of elaidic acid in the THz band were investigated by using THz time-domain spectroscopy (THZ-TDS). The absorption and refractive index spectra in the frequency range from 0.5 to 2.5 THz were obtained at room temperature under nitrogen atmosphere, and the results show that elaidic acid had some characteristic absorption peaks, and the average refractive index of the sample was 1.43. The structure and vibrational frequencies of elaidic acid molecule in the THz range were simulated by the B3LYP algorithm of density functional theory, and the THz characteristic absorption peaks of elaidic acid molecule were identified by using Gaussian View software. The results show that the experimental and theoretical results agree in general, and the observed absorption peaks in the THz range were mainly caused by the intramolecular and intermolecular vibrations jointly. At the same time, the fingerprint spectra of elaidic acid in the THz band verify that the time-domain terahertz spectroscopy can be used to detect oleic acid, and this study provides a new experimental method for the detection of trans fatty acids in food.


Assuntos
Ácido Oleico/análise , Espectroscopia Terahertz , Ácidos Oleicos
7.
Guang Pu Xue Yu Guang Pu Fen Xi ; 31(12): 3206-9, 2011 Dec.
Artigo em Chinês | MEDLINE | ID: mdl-22295760

RESUMO

The terahertz spectra of Clenbuterol hydrochloride in the range of 0.2 to 2.6 THz were obtained by THz time-domain spectroscopy, the absorption and refraction spectra of Clenbuterol hydrochloride was got meanwhile. The structure and vibrational frequencies of Clenbuterol molecule, Clenbuterol hydrochloride molecule and Clenbuterol hydrochloride crystal in the THz range were simulated. Based on the difference between experimental and theoretical results, the origin of the vibrational frequencies was analyzed. This study demonstrated the feasibility of time-domain terahertz spectroscopy for the identification of Clenbuterol hydrochloride and provides a new way for the detection of Clenbuterol hydrochloride.


Assuntos
Clembuterol , Espectroscopia Terahertz , Vibração
8.
Guang Pu Xue Yu Guang Pu Fen Xi ; 29(7): 1729-31, 2009 Jul.
Artigo em Chinês | MEDLINE | ID: mdl-19798927

RESUMO

The present paper reports the theoretical and experimental vibrational frequencies of L-ascorbic acid in the frequency range from 0.2 to 2.4 THz respectively. The vibrational frequencies of L-ascorbic acid in the THz range were simulated by Becke-3-Lee-Yang-Parr (B3LYP) algorithm of density functional theory. Simultaneously, the absorption and refractive index spectra of L-ascorbic acid were obtained using terahertz time-domain spectroscopy (THz-TDS). Based on the results from density functional calculations, the observed vibrational peaks were assigned with the aid of Gaussian View 3.07. Finally, the tera-hertz absorption spectra of tablets of vitamin C were compared with those of L-ascorbic acid. It was found that L-ascorbic acid had some distinct fingerprint spectra in the THz region and the theoretical results were in good agreement with the experimental results. The observed vibrational peaks were induced jointly by the intramolecular and intermolecular vibrations. The absorption peaks of L-ascorbic acid could be observed in the absorption spectra of the tablets of vitamin C. Our research is helpful to understanding the role of L-ascorbic acid in biological reactions. Still, the research results show the potential of the application of THz-TDS in the quantification of L-ascorbic acid.

9.
Guang Pu Xue Yu Guang Pu Fen Xi ; 28(8): 1718-21, 2008 Aug.
Artigo em Chinês | MEDLINE | ID: mdl-18975787

RESUMO

Terahertz radiation generated by ultra short laser pulses has a broad band width in the far-infrared range. Terahertz wave interacting with materials is a new research field. In this paper, we performed measurement of absorption coefficient and refractive index of imidacloprid in the frequency range 0.2-2.0 THz at room temperature by THz-TDS. The results indicate that imidacloprid has absorption fingerprints in this frequency range, and the absorption coefficient increases with the frequency. The average refractive index of imidacloprid is 1.65, and the refractive index of imidacloprid increases slightly with frequency. A semi-empirical theory was applied to obtain the structure and vibrational frequencies of the imidacloprid molecules in THz region. The calculated results agree well with the experimental data. The absorption features are caused by the collective vibrational and torsional modes, and different absorption peaks correspond to different vibrational modes. The comparison between experimental and theoretical study shows that far-infrared absorption features are highly sensitive to the structure and spatial arrangement of the molecules. THz-TDS is a potential tool to understand the collective vibrational modes and conformational structures of biomolecules.

10.
Wound Repair Regen ; 15(1): 66-70, 2007.
Artigo em Inglês | MEDLINE | ID: mdl-17244321

RESUMO

To determine whether parenteral L-arginine supplementation enhances the impaired wound healing of rats subjected to trauma/hemorrhagic shock. Impaired wound healing after trauma and shock has been documented experimentally and clinically. L-arginine has been shown to enhance wound strength and collagen synthesis in rodents and humans. Its efficacy under conditions of impaired wound healing is less well defined. Forty-eight male Lewis rats were used in this study. Using a well-defined model, 24 rats underwent trauma/hemorrhagic shock before wounding. Twenty-four untreated rats served as controls. All animals underwent a dorsal skin incision with implantation of polyvinyl-alcohol sponges. Half of the animals in each group were assigned to receive 1 g/kg/day of L-arginine by intraperitoneal injection in three divided doses, while the other half received saline injections only. Animals were sacrificed 10 days postwounding, and wound-breaking strength (WBS) and wound sponge total hydroxyproline (OHP) and nitrite/nitrate (NO(x)) content were determined. Wound sponge RNA was collected and subjected to Northern blot analysis for procollagens I and III. Trauma/hemorrhage greatly decreased WBS with a concomitant diminution in collagen (OHP) deposition. L-arginine significantly enhanced WBS (19%) and increased OHP (21%) levels in control animals as well as in rats subjected to trauma/hemorrhage (WBS +29%, OHP 40%) compared with their saline-treated counterparts. Procollagen I and III mRNA levels were elevated by L-arginine treatment in both trauma/hemorrhage and control rats. Arginine treatment had no effect on wound fluid and plasma NO(x). The data demonstrate that the impaired healing subsequent to trauma/hemorrhage can be greatly alleviated by L-arginine supplementation.


Assuntos
Arginina/farmacologia , Choque Hemorrágico/fisiopatologia , Choque Traumático/fisiopatologia , Pele/lesões , Cicatrização/efeitos dos fármacos , Ferimentos Penetrantes/fisiopatologia , Animais , Masculino , Óxido Nítrico/metabolismo , Pró-Colágeno/metabolismo , Ratos , Ratos Endogâmicos Lew , Ferimentos Penetrantes/metabolismo , Ferimentos Penetrantes/terapia
11.
Huan Jing Ke Xue ; 26(3): 49-55, 2005 May.
Artigo em Chinês | MEDLINE | ID: mdl-16124469

RESUMO

The laws of purification of stream nitrogen and phosphorus by riparian wetland was studied by sampling in Long'an Bridge and Shuiku Bridge reaches in Zhalong Wetland. Results from the spatial purifying equations show that two reaches exhibited persistent capability of purification of TP and PO4(3-) through out the seasons of spring, summer and fall, and the purifying coefficient of TP fluctuates from 0.00186 to 0.01175 mg x (L x km)(-1) while the PO4(3-)'s was from 2.5E-4 to 0.00704 mg x (L x km)(-1). As to TN, the purification occured only in the seasons of spring and summer while in fall it experienced accumulation downwards along the streamflow, and the output capability was up to 0.48175 mg x (L x km)(-1). Analysis of effect factors show runoff and input concentration have a certain influence on the purification capability.


Assuntos
Nitrogênio/análise , Fósforo/análise , Eliminação de Resíduos Líquidos/métodos , Poluentes Químicos da Água/análise , Purificação da Água/métodos , Bactérias/metabolismo , Biodegradação Ambiental , China , Eliminação de Resíduos Líquidos/economia , Microbiologia da Água , Purificação da Água/economia
13.
J Zhejiang Univ Sci ; 5(12): 1597-603, 2004 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-15547970

RESUMO

Beer fermentation is a dynamic process that must be guided along a temperature profile to obtain the desired results. Ant colony system algorithm was applied to optimize the kinetic model of this process. During a fixed period of fermentation time, a series of different temperature profiles of the mixture were constructed. An optimal one was chosen at last. Optimal temperature profile maximized the final ethanol production and minimized the byproducts concentration and spoilage risk. The satisfactory results obtained did not require much computation effort.


Assuntos
Algoritmos , Cerveja/microbiologia , Reatores Biológicos/microbiologia , Retroalimentação/fisiologia , Fermentação/fisiologia , Modelos Biológicos , Temperatura , Técnicas de Cultura de Células/métodos , Simulação por Computador
14.
Zhonghua Liu Xing Bing Xue Za Zhi ; 24(12): 1070-3, 2003 Dec.
Artigo em Chinês | MEDLINE | ID: mdl-14761616

RESUMO

OBJECTIVE: To study the use of hypertension related physical examinations, laboratory tests and anti-hypertension drugs among district and community based hospitals in Beijing and to analyze the possible hardware (examination, test, drug) problems under the application of the "China Hypertension Guide" in those hospitals. METHODS: The survey was carried out in 40 hospitals in Chaoyang and Haidian districts, including 9 district level hospitals, and the rest at community level. Questionnaire survey and in-depth interview were used to collect information from the leaders of related departments in those hospitals. RESULTS: (1) The hardware condition of district hospital satisfied the implicit requirements of hypertension evaluation and treatment in "China hypertension Guide". (2) 64.5% of the community level hospitals had the basic equipments and routine laboratory tests for diagnosis and treatment on hypertension, but 35.5% of them lack of tests on blood chemistry (potassium, sodium, creatinine) and urine protein. (3) 71.0% of community level hospitals could not judge the patient's "target organ damage" independently. (4) Both district and community level hospitals had all major types of anti-hypertension drugs in there pharmacy except ARB. CONCLUSION: When necessary laboratory tests for both district and community level hospitals were provided, they could accomplish the tasks of hypertension treatment and management. However, the community level hospitals should cooperate with hospitals at higher level to have a comprehensive clinical understanding of patients with high blood pressure.


Assuntos
Técnicas de Laboratório Clínico/estatística & dados numéricos , Hospitais Comunitários/estatística & dados numéricos , Hipertensão/diagnóstico , Hipertensão/tratamento farmacológico , China , Estudos Transversais , Serviços de Diagnóstico/estatística & dados numéricos , Humanos , Assistência Farmacêutica/estatística & dados numéricos , Inquéritos e Questionários
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