检索结果-南通市图书馆

NEAR-FIELD ACOUSTIC HOLOGRAPHY FOR SEMI-FREE ACOUSTIC FIELD BASED ON WAVE SUPERPOSITION APPROACH

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Mechanical Engineering 2006年第3期19卷 455-459页

作者： LI Weibing chen jian yu Fei chen Xinzhao Institute of Sound and Vibration Research Hefei University of Technology Hefei 230009 China

In the semi-free acoustic field, the actual acoustic pressure at any point is composed of two parts： The direct acoustic pressure and the reflected acoustic pressure. The general acoustic holographic theories and algorithms request that there is only the direct acoustic pressure contained in the pressure at any point on the hologram surface, consequently, they cannot be used to reconstruct acoustic source and predict acoustic field directly. To take the reflected pressure into consideration, near-field acoustic holography for semi-free acoustic field based on wave superposition approach is proposed to realize the holographic reconstruction and prediction of the semi-free acoustic field, and the wave superposition approach is adopted as a holographic transform algorithm. The proposed theory and algorithm are realized and verified with a numerical example, and the drawbacks of the general theories and algorithms in the holographic reconstruction and prediction of the semi-free acoustic field are also demonstrated by this numerical example.

关键词： Near-field acoustical holography Semi-free acoustic field Wave superposition approach

Unimolecular artificial transmembrane channel with terminal dihydrogen phosphate groups showing transport selectivity for ammonium

在线全文

学校读者我要写书评

暂无评论

Chinese Chemical Letters 2020年第1期31卷 77-80页

作者： jian-yu chen Qi Xiao Harekrushna Behera Jun-Li Hou Department of Chemistry Fudan University

A new artificial transmembrane channel molecule bearing dihydrogen phosphate groups has been *** terminal dihydrogen phosphate groups enable the channel to be highly negatively charged at both ends of the channel *** artificial channel could incorporate into the lipid bilayer efficiently under low *** channel displays high NH4+/K+selectivity due to the electrostatic interaction and hydrogen bonding between NH4+and the terminal dihydrogen phosphate groups.

关键词： Artificial transmembrane channel Ammonium transport Dihydrogen phosphate Pillararene Transmembrane transport Transport selectivity

Primary clear cell carcinoma in the liver: CT and MRI findings

在线全文

学校读者我要写书评

暂无评论

World Journal of Gastroenterology 2011年第7期17卷 946-952页

作者： Qing-yu Liu Hai-Gang Li Ming Gao Xiao-Feng Lin Yong Li jian-yu chen Department of Radiology The Second Affiliated Hospitalof Sun Yat-sen University Guangzhou 510120 Guangdong Prov-ince China Department of Pathology The Second Affiliated Hospital of Sun Yat-sen University Guangzhou 510120Guangdong Province China

AIM: To retrospectively analyze the computed tomography (CT) and magnetic resonance imaging (MRI) appearances of primary clear cell carcinoma of the liver (PCCCL) and compare the imaging appearances of PCCCL and common type hepatocellular carcinoma (CHCC) to determine whether any differences exist between the two groups. METHODS: Twenty cases with pathologically proven PCCCL and 127 cases with CHCC in the Second Affiliated Hospital of Sun Yat-sen University were included in this study. CT or MRI images from these patients were retrospectively analyzed. The following imaging findings were reviewed: the presence of liver cirrhosis, tumor size, the enhancement pattern on dynamic contrast scanning, the presence of pseudo capsules, tumor rupture, portal vein thrombosis and lymph node metastasis. RESULTS: Both PCCCL and CHCC were prone to occur in patients with liver cirrhosis, the association rate of liver cirrhosis was 80.0% and 78.7%, respectively (P > 0.05). The mean sizes of PCCCL and CHCC tumors were (7.28 ± 4.25) cm and (6.96 ± 3.98) cm, respectively. Small HCCs were found in 25.0% (5/20) of PCCCL and 19.7% (25/127) of CHCC cases. No significant differences in mean size and ratio of small HCCs were found between the two groups (P = 0.658 and 0.803, respectively). Compared with CHCC patients, PCCCL patients were more prone to form pseudo capsules (49.6% vs 75.0%, P = 0.034). Tumor rupture, typical HCC enhancement patterns and portal vein tumor thrombosis were detected in 15.0% (3/20), 72.2% (13/18) and 20.0% (4/20) of patients with PCCCL and 3.1% (4/127), 83.6% (97/116) and 17.3% (22/127) of patients with CHCC, respectively. There were no significant differences between the two groups (all P > 0.05). No patients with PCCCL and 2.4% (3/127) of patients with CHCC showed signs of lymph node metastasis (P > 0.05). CONCLUSION: The imaging characteristics of PCCCL are similar to those of CHCC and could be useful for differentiating these from other liver tumors (such as h

关键词： Clear cell carcinoma Hepatocellular carcinoma Pathology Magnetic resonance imaging Computed Tomography X-ray

Metabolism of Terephthalic Acid and Its Effects on CYP4B1 Induction

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Biomedical and Environmental Sciences 2006年第1期19卷 8-14页

作者： GUI-DONG DAI LUN-BIAO CUI LING SONG REN-ZHEN ZHAO jian-FENG chen yu-BANG WANG HEBRON C. CHANG AND XIN-RU WANG Institute of Toxicology Nanjing Medical University 140 Hanzhong Road Nanjing 210029 Jiangsu China

Objective To investgate the metabolism of terephthalic acid （TPA） in rats and its mechanism. Methods Metabolism was evaluated by incubating sodium terephthalate （NaTPA） with rat normal liver microsomes, or with microsomes pretreated by phenobarbital sodium, or with 3-methycholanthrene, or with diet control following a NADPH-generating system. The determination was performed by high performance liquid chromatography （HPLC）, and the mutagenic activation was analyzed by umu tester strain Salmonella typhimurium NM2009. Expression of CYP4B 1 mRNA was detected by RT-PCR. Results The amount of NaTPA （12.5-200 μmol-L^1） detected by HPLC did not decrease in microsomes induced by NADPH-generating system. Incubation of TPA （0.025-0.1 mmol-L^-1） with induced or noninduced liver microsomes in an NM2009 umu response system did not show any mutagenic activation. TPA exposure increased the expression of CYP4B1 mRNA in rat liver, kidney, and bladder. Contusion Lack of metabolism of TPA in liver and negative genotoxic data from NM2009 study are consistent with other previous short-term tests, suggesting that the carcinogenesis in TPA feeding animals is not directly interfered with TPA itself and/or its metabolites.

关键词： Terephthalic acid Metabolism Microsomes High performance liquid chromatography umu gene expression CYP4B1

Reconstruction and prediction of coherent acoustic field with the combined wave superposition approach

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Acoustics 2006年第2期25卷 124-138页

作者： LI Weibing chen jian yu Fei chen Xinzhao Institute of sound and vibration research Hefei University of Technology Hefei 230009

The routine wave superposition approach cannot be used in reconstruction and prediction of a coherent acoustic field, because it is impossible to separate the pressures generated by individual sources. According to the superposition theory of the coherent acoustic field , a novel method based on the combined wave superposition approach is developed to reconstruct and predict the coherent acoustic field by building the combined pressure matching matrixes between the hologram surfaces and the sources. The method can reconstruct the acoustic information on surfaces of the individual sources, and it is possible to predict the acoustic field radiated from every source and the total coherent acoustic field can also be calculated spontaneously. The experimental and numerical simulation results show that this method can effectively solve the holographic reconstruction and prediction of the coherent acoustic field and it can also be used as a coherent acoustic field separation technique. The study on this novel method extends the application scope of the acoustic holography technique.

关键词： wave superposition acoustic field holographic reconstruction separation technique acoustic holography simulation results application scope used in

Off-line analysis of single-unit neuronal discharge in the globus pallidus region in Parkinson＇s disease

在线全文

学校读者我要写书评

暂无评论

Chinese Medical Journal 2010年第14期123卷 1884-1887页

作者： ZHAO Ya-qun ZHOU Jing-an WANG Yong yu jian-chen ZHANG Hui Department of Neurosurgery 309th Clinical Department of Chinese People's Liberation Army General Hospital Beijing 100091 China Institute of Biomedicine Xi'an Jiaotong University of China Xi'an 710054 China

Background The accuracy of microelectrode-guided localization can make the operation safe and effective, but only experienced neurosurgeons are capable of performing this operation. A good index to identify neuronal discharges between globus pallidus interna and globus pallidus externa is needed. The aim of this research was to establish a good and practical electrophysiologic index to distinguish neuronal discharge in the interior globus pallidus from neuronal discharge in the exterior globus pallidus region of the brain in Parkinson＇s disease. The effect of neurons having an atypical discharge on successful surgical localization was also quantitatively evaluated Methods The study included 30 patients with primary Parkinson＇s disease who underwent pallidotomy between September 2000 and October 2002. During each pallidotomy, the neuronal discharges in the pallidum and its vicinity were recorded. The recorded spikes were used to calculate the frequency, burst index, pause index, and pause ratio of the single-unit discharge. The interior and exterior globus pallidus regions were compared in terms of frequency, burst index, pause index, and pause ratio. The sensitivity, specificity, false-negative ratio, false-positive ratio, and accuracy of those indices were then evaluated. Results The values of frequency, burst index, pause index, and pause ratio in the interior globus pallidus were （96±43） Hz, 2.31±1.81, 0.05±0.05, and 0.27±0.28, respectively, and in the exterior globus pallidus were （59±27） Hz, 0.88±0.63, 0.20±0.14, and 1.54±1.17, respectively. Use of the four indices to distinguish the two neuron types produced a sensitivity of 0.84, 0.78, 0.77, and 0.93 with a specificity of 0.64, 0.79, 0.88, and 0.87, respectively. The false-positive ratio was 0.36, 0.21, 0.12, and 0.13 and the false-negative ratio was 0.16, 0.22, 0.23, and 0.07 while the accuracy was 0.72, 0.79, 0.80, and 0.90, respectively. Conclusions Pause ratio is a relatively reliable index to distinguish

关键词： Parkinson's disease globus pallidus neural discharge intraoperative localization comparative study

Synthesis and Crystal Structure of Complex [Cdq3][Cd（qH）3]（ClO4）CH3OH （q=8-Quinolinolate, qH= 8-Quilinolinol）

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Structural Chemistry 2005年第8期 913-916+861页

作者： SHI Jing-Min② ZHANG Xia LU jian-Jun chen yu-Qin MA jian-Ping LIU Lian-Dong (Department of Chemistry, Shandong Normal University, Jinan 250014, China)

The mono-nuclear complex [Cdq3][Cd(qH)3](ClO4)CH3OH has been synthesized by 8-quinolinol and hydrated cadmium perchlorate in methanol solution. The crystal belongs to triclinic, space group P1 with a = 11.1449(15), b = 13.3334(18), c = 17.654(2) ?, α = 85.555(2), β = 88.497(2), γ = 75.681(2)°, V = 2534.1(6) ?3, Z = 1, C110H86Cd4Cl2 N12O22, Mr = 2448.41, Dc = 1.604 g/cm3, F(000) = 1232 and μ = 0.961 mm-1. The structure was refined to R = 0.0387 and wR = 0.0973 for 7775 observed reflections (I > 2σ(I)). In this crystal there exist two independent mono- nuclear complexes of [Cdq3]- and [Cd(qH)3]2+. Each cell contains two [Cdq3]- anions, two [Cd- (qH)3]2+ cations, two ClO4- anions and two methanol molecules.

关键词： crystal structure cadmium complex 8-quinolinol

Racl＋ cells distributed in accordance with CD 133＋ cells in glioblastomas and the elevated invasiveness of CD 133＋ glioma cells with higher Racl activity

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Chinese Medical Journal 2012年第24期 4344-4348页

作者： ZHANG Bin SUN jian yu Sheng-ping chen Cong LIU Bin LIU Zhi-feng REN Bing-cheng MING Hao-lang YANG Xue-jun Department of Neurosurgery Tianjin Medical University General Hospital Tianjin 300052 China

Background Recent studies have suggested that cancer stem cells are one of the major causes for tumor recurrence due to their resistance to radiotherapy and chemotherapy. Although the highly invasive nature of glioblastoma （GBM） cells is also implicated in the failure of current therapies, it is not clear how glioma stem cells （GSCs） are involved in invasiveness. Racl activity is necessary for inducing reorganization of actin cytoskeleton and cell movement. In this study, we aimed to investigate the distribution characteristics of CD133＋ cells and Racl＋ cells in GBM as well as Racl activity in CD133＋ GBM cells, and analyze the migration and invasion potential of these cells. Methods A series of 21 patients with GBM were admitted consecutively and received tumor resection in Tianjin Medical University General Hospital during the first half of the year 2011. Tissue specimens were collected both from the peripheral and the central parts for each tumor under magnetic resonance imaging （MRI） navigation guidance. Immunohistochemical staining was used to detect the CD133＋ cells and Racl＋ cells distribution in GBM specimens. Double-labeling immunofluorescence was further used to analyze CD133 and Racl co-expression and the relationship between CD133＋ cells distribution and Racl expression. Serum-free medium culture and magnetic sorting were used to isolate CD133＋ cells from U87 cell line. Racl activation assay was conducted to assess the activation of Racl in CD133＋ and CD133- U87 cells. The migration and invasive ability of CD133＋ and CD133- U87 cells were determined by cell migration and invasion assays in vitro. Student＇s t-test and one-way analysis of variance （ANOVA） test were used to determine statistical significance in this study. Results In the central parts of GBMs, CD133＋ cells were found to cluster around necrosis and occasionally cluster around the vessels under the microscope by immunohistological staining. In the peripheral parts of the tumors, CD133＋ cells w

关键词： glioblastoma stem cells invasion migration Racl

Mechanistic insight into the synergy between nickel single atoms and nanoparticles on N-doped carbon for electroreduction of CO2

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Energy Chemistry 2025年第1期100卷 327-336页

作者： Mingdong Sun Wenwen Guan Cailing chen Chao Wu Xiaoling Liu Biao Meng Tao chen yu Han Jun Wang Shibo Xi yu Zhou State Key Laboratory of Materials-Oriented Chemical Engineering College of Chemical Engineering Nanjing Tech University Advanced Membranes and Porous Materials Center Physical Sciences and Engineering Division King Abdullah University of Science and Technology Institute of Sustainability for Chemicals Energy and Environment A*STAR (Agency for Science Technology and Research) College of Materials Science and Engineering Sichuan University

The synergy of single atoms （SAs） and nanoparticles （NPs） has demonstrated great potential in promoting the electrocatalytic carbon dioxide reduction reaction （CO2RR）;however,the rationalization of the SAs/NPs proportion remains one challenge for the catalyst ***,a Ni2+-loaded porous poly（ionic liquids）(PIL) precursor synthesized through the free radical self-polymerization of the ionic liquid monomer,1-allyl-3-vinylimidazolium chloride,was pyrolyzed to prepare the Ni,N co-doped carbon materials,in which the proportion of Ni SAs and NPs could be facilely modulated by controlling the annealing *** catalyst Ni-NC-1000 with a moderate proportion of Ni SAs and NPs exhibited high efficiency in the electrocatalytic conversion of CO2into *** Ni K-edge X-ray absorption near-edge structure （XANES） spectra and theoretical calculations were conducted to gain insight into the synergy of Ni SAs and *** charge transfer from Ni NPs to the surrounding carbon layer and then to the Ni SAs resulted in the electron-enriched Ni SAs active *** the electroreduction of CO2,the coexistence of Ni SAs and NPs strengthened the CO2activation and the affinity towards the key intermediate of*COOH,lowering the free energy for the potential-determining*CO2→*COOH step,and therefore promoted the catalysis efficiency.

关键词： Single atom catalyst Synergy effect Carbon catalyst Electrocatalysis