220 research outputs found

    Review: Groundwater recharge estimation in northern China karst regions

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    Reliable estimates of groundwater recharge are crucial for the groundwater resources evaluating and sustainable utilization plans formulating. To protect the precious karst groundwater resources, this paper critically reviewed the previous studies on karst groundwater recharge in northern China karst regions from the perspective of diffuse recharge and focused recharge, and took Niangziguan Spring catchment as a case study. It is concluded that for the 119 karst groundwater systems, 52% occur diffuse recharge through precipitation infiltration, 48% occur both diffuse recharge through precipitation infiltration and focused recharge through surface water leakage. The mean annual precipitation, diffuse recharge and infiltration coefficient (IC, as percentage of precipitation) are 560 mm, 136 mm and 23.1%, respectively. A high correlation was observed between annual precipitation and annual diffuse recharge with a nonlinear relationship. The IC can vary substantially even with the same annual precipitation between 9.3 and 38.0%, with an evidently increasing trend eastward. This reflects a significant difference in the degree of karstification for the northern karst regions. The most commonly applied for recharge assessment in northern China karst regions is equal volume spring flow method, the chloride mass balance method is highly recommended for groundwater recharge estimation of the regions based on the case study. This work provides reference for recharge estimation, assessment and management of karst groundwater resources in northern China

    Facile Preparation of g-C3N4-WO3 Composite Gas Sensing Materials with Enhanced Gas Sensing Selectivity to Acetone

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    In this paper, g-C3N4-WO3 composite materials were prepared by hydrothermal processing. The composites were characterized by means of X-ray powder diffraction (XRD), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), and N2 adsorption-desorption, respectively. The gas sensing properties of the composites were investigated. The results indicated that the addition of appropriate amount of g-C3N4 to WO3 could improve the response and selectivity to acetone. The sensor based on 2 wt% g-C3N4-WO3 composite showed the best gas sensing performances. When operating at optimum temperature of 310°C, the responses to 1000 ppm and 0.5 ppm acetone were 58.2 and 1.6, respectively, and the ratio of the S1000 ppm acetone to S1000 ppm ethanol reached 3.7

    Gap Solitons and Bloch Waves in Nonlinear Periodic Systems

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    We comprehensively investigate gap solitons and Bloch waves in one-dimensional nonlinear periodic systems. Our results show that there exists a composition relation between them: Bloch waves at either the center or edge of the Brillouin zone are infinite chains composed of fundamental gap solitons(FGSs). We argue that such a relation is related to the exact relation between nonlinear Bloch waves and nonlinear Wannier functions. With this composition relation, many conclusions can be drawn for gap solitons without any computation. For example, for the defocusing nonlinearity, there are nn families of FGS in the nnth linear Bloch band gap; for the focusing case, there are infinite number of families of FGSs in the semi-infinite gap and other gaps. In addition, the stability of gap solitons is analyzed. In literature there are numerical results showing that some FGSs have cutoffs on propagation constant (or chemical potential), i.e. these FGSs do not exist for all values of propagation constant (or chemical potential) in the linear band gap. We offer an explanation for this cutoff.Comment: A longer version of our recent paper, PRL 102, 093905 (2009

    Pharmacokinetics and bioequivalence evaluation of acamprosate calcium tablets in healthy Chinese volunteers

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    AbstractBackgroundFew pharmacokinetic data of acamprosate were available in Chinese population and no medication is approved for alcohol dependence in China.Purpose1. Investigate the pharmacokinetic properties of acamprosate calcium in healthy Chinese male volunteers on single- and multiple-dose administration. 2. Compare the bioequivalence of two formulations of acamprosate calcium tablets both under fasting and fed conditions.MethodsThis open-label, randomized study included 3 stages. In each stage, a 2-way crossover bioequivalence study was conducted to study the pharmacokinetic properties and bioequivalence of acamprosate calcium tablets on multiple dosing after standardized meals, single dosing under fasting conditions and fed conditions, respectively. The washout period between each treatment in a stage and between each stage was 1week. Plasma acamprosate calcium was quantified by a validated liquid chromatography-tandem mass spectrometry (LC-MS/MS) method. Tolerability was evaluated by monitoring adverse events, physical examinations, 12-lead ECG, and laboratory tests.ResultsTotally, 36 male subjects were enrolled in the study and all of them completed the whole 3 study stages. Main pharmacokinetic parameters of test and reference formulations were as follows: multiple dosing, Tmax 9.94±6.59 and 9.47±5.47h, Cmax 435.74±348.10 and 346.54±155.66ng·mL−1, AUC0-t 8600.52±5264.77 and 9315.10±6820.03ng·mL−1·h, AUC0–∞ 8845.38±5838.18 and 9669.24±7326.53ng·mL−1·h, t1/2 10.06±8.83 and 9.87±10.35h; single dosing under fasting conditions, Tmax 7.29±4.87 and 6.57±1.85h, Cmax 247.85±110.05 and 244.64±132.43ng·mL−1, AUC0-t 3385.41±1418.92 and 3496.24±1767.29ng·mL−1·h, AUC0–∞ 3781.53±1556.96 and 3829.56±1981.25ng·mL−1·h, t1/2 13.07±17.24 and 10.26±7.78h; single dosing under fed conditions, Tmax 17.72±9.42 and 19.50±9.84h, Cmax 183.90±74.52 and 168.14±60.67ng·mL−1, AUC0-t 3181.71±1368.24 and 3575.11±1416.39ng·mL−1·h, AUC0–∞3442.39±2002.53 and 3624.44±1418.12ng·mL−1·h, t1/2 8.76±12.28 and 6.67±4.84h, respectively. In all three stages, 90% CIs for the test/reference ratio of AUC0–t and AUC0–∞ were located within 80%–125%, 90% CI for Cmax was within 70%–143%.ConclusionsSimilar pharmacokinetic results of acamprosate calcium tablets in healthy Chinese volunteers were found as those in Caucasic population. In all three stages, the two formulations met the regulatory criteria for bioequivalence.Chictr.org identifier: ChiCTR-TTRCC-14004853

    Implications of C1q/TNF-related protein superfamily in patients with coronary artery disease.

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    The C1q complement/TNF-related protein superfamily (CTRPs) displays differential effects on the regulation of metabolic homeostasis, governing cardiovascular function. However, whether and how they may serve as predictor/pro-diagnosis factors for assessing the risks of coronary artery disease (CAD) remains controversial. Therefore, we performed a clinical study to elaborate on the implication of CTRPs (CTRP1, CTRP5, CTRP7, and CTRP15) in CAD. CTRP1 were significantly increased, whereas CTRP7 and CTRP15 levels were decreased in CAD patients compared to the non-CAD group. Significant differences in CTRP1 levels were discovered between the single- and triple-vascular-vessel lesion groups. ROC analysis revealed that CTRP7 and CTRP15 may serve as CAD markers, while CTRP1 may serve as a marker for the single-vessel lesion of CAD. CTRP1 and CTRP5 can serve as markers for the triple-vessel lesion. CTRP1 may serve as an independent risk predictor for triple-vessel lesion, whereas CTRP15 alteration may serve for a single-vessel lesion of CAD. CTRP1 may serve as a novel superior biomarker for diagnosis of severity of vessel-lesion of CAD patients. CTRP7, CTRP15 may serve as more suitable biomarker for the diagnosis of CAD patients, whereas CTRP5 may serve as an independent predictor for CAD. These findings suggest CTRPs may be the superior predictive factors for the vascular lesion of CAD and represent novel therapeutic targets against CAD

    Research on Non-Linearity Percolation Characteristics in Tight Sandstone Gas Reservoir

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    The microcosmic pore throat structure is complex in tight sandstone reservoir so that the fluid lodging situation and flow condition in the pore space is difficult to determine, which has an influence on the effective displacement and efficient development directly. Research on gas/water percolation feature in the formation is the foundation of recognizing the tight gas reservoir. Taking a tight gas reservoir block in Ordos Basin for example, constant speed mercury-injection method is carried on leading to a research and analysis about microcosmic pore throat structure features and fluid physical property relative parameters in the formation. Using the steady-state method, an experiment has been done that takes 15 pieces of cores as examples which gets gas/water relative permeability curves. We conduct normalization processing and analyze relative permeability characteristics. Flow-pressure testing method is applied for studying gas/water relative permeability features. In view of the tight gas, the permeability is lower and the velocity of flow is more slowly under a certain pressure difference. By controlling differential pressure, flow velocity’s subtle changes are tested and the commensurable curve can be got. Research shows that the water liquidity in the small pore throat is poorer and the residual water saturation is higher; the two-phase seepage area spans a narrow range while the whole liquidity is poorer; there is threshold pressure gradient in the tight sandstone formation so that it presents non-linear seepage characteristics; the threshold pressure gradient in the target block is higher at about 0.151 MPa/m. Based on the above reasons, effective displacement in the tight gas reservoir gets more difficult.Key words: Tight gas; Gas/water relative permeability features; Non-linearity seepage; Threshold pressure gradien

    Celastrol nanoparticles inhibit corneal neovascularization induced by suturing in rats

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    Zhanrong Li1, Lin Yao1, Jingguo Li2, Wenxin Zhang1, Xianghua Wu1, Yi Liu1, Miaoli Lin1, Wenru Su1, Yongping Li1, Dan Liang11State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-Sen University, 2School of Chemistry and Chemical Engineering, Sun Yat-Sen University, Guangzhou, People's Republic of ChinaPurpose: Celastrol, a traditional Chinese medicine, is widely used in anti-inflammation and anti-angiogenesis research. However, the poor water solubility of celastrol restricts its further application. This paper aims to study the effect of celastrol nanoparticles (CNPs) on corneal neovascularization (CNV) and determine the possible mechanism.Methods: To improve the hydrophilicity of celastrol, celastrol-loaded poly(ethylene glycol)-block-poly(ε-caprolactone) nanopolymeric micelles were developed. The characterization of CNPs was measured by dynamic light scattering and transmission electron microscopy analysis. Celastrol loading content and release were assessed by ultraviolet-visible analysis and high performance liquid chromatography, respectively. In vitro, human umbilical vein endothelial cell proliferation and capillary-like tube formation were assayed. In vivo, suture-induced CNV was chosen to evaluate the effect of CNPs on CNV in rats. Immunohistochemistry for CD68 assessed the macrophage infiltration of the cornea on day 6 after surgery. Real-time quantitative reverse transcription-polymerase chain reaction and enzyme-linked immunosorbent assay were used to evaluate the messenger ribonucleic acid and protein levels, respectively, of vascular endothelial growth factor, matrix metalloproteinase 9, and monocyte chemoattractant protein 1 in the cornea.Results: The mean diameter of CNPs with spherical shape was 48 nm. The celastrol loading content was 7.36%. The release behavior of CNPs in buffered solution (pH 7.4) showed a typical two-phase release profile. CNPs inhibited the proliferation of human umbilical vein endothelial cells in a dose-independent manner and suppressed the capillary structure formation. After treatment with CNPs, the length and area of CNV reduced from 1.16 ± 0.18 mm to 0.49 ± 0.12 mm and from 7.71 ± 0.94 mm2 to 2.29 ± 0.61 mm2, respectively. Macrophage infiltration decreased significantly in the CNP-treated corneas. CNPs reduced the expression of vascular endothelial growth factor, matrix metalloproteinase 9, and monocyte chemoattractant protein 1 in the cornea on day 6 after suturing.Conclusion: CNPs significantly inhibited suture-induced CNV by suppressing macrophage infiltration and the expression of vascular endothelial growth factor and matrix metalloproteinase 9 in the rat cornea.Keywords: celastrol, PEG-b-PCL nanopolymeric micelles, corneal neovascularization, macrophages, VEGF, MMP-

    Antitumor activity of celastrol nanoparticles in a xenograft retinoblastoma tumor model

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    Zhanrong Li,1,* Xianghua Wu,1,* Jingguo Li,2 Lin Yao,1 Limei Sun,1 Yingying Shi,1 Wenxin Zhang,1 Jianxian Lin,1 Dan Liang,1 Yongping Li1 1State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, 2School of Chemistry and Chemical Engineering, Sun Yat-Sen University, Guangzhou, People's Republic of China*These authors contributed equally to this workBackground: Celastrol, a Chinese herbal medicine, has shown antitumor activity against various tumor cell lines. However, the effect of celastrol on retinoblastoma has not yet been analyzed. Additionally, the poor water solubility of celastrol restricts further therapeutic applications. The goal of this study was to evaluate the effect of celastrol nanoparticles (CNPs) on retinoblastoma and to investigate the potential mechanisms involved.Methods: Celastrol-loaded poly(ethylene glycol)-block-poly(ε-caprolactone) nanopolymeric micelles were developed to improve the hydrophilicity of celastrol. The 2-(2-methoxy-4-nitrophenyl)-3-(4-nitrophenyl)-5-(2,4-disulf-ophenyl)-2H tetrazolium monosodium salt (WST-8) assay was used to determine the inhibitory effect of CNPs on SO-Rb 50 cell proliferation in vitro. Immunofluorescence was used to evaluate the apoptotic effect of CNPs on nuclear morphology, and flow cytometry was used to quantify cellular apoptosis. The expression of Bcl-2, Bax, NF-κB p65, and phospo-NF-κB p65 proteins was assessed by Western blotting. A human retinoblastoma xenograft model was used to evaluate the inhibitory effects of CNPs on retinoblastoma in NOD-SCID mice. Hematoxylin and eosin staining was used to assess the apoptotic effects of CNPs on retinoblastoma.Results: CNPs inhibit the proliferation of SO-Rb 50 cells in a dose- and time-dependent manner with an IC50 of 17.733 µg/mL (celastrol-loading content: 7.36%) after exposure to CNPs for 48 hours. CNPs induce apoptosis in SO-Rb 50 cells in a dose-dependent manner. The expression of Bcl-2, NF-κB p65, and phospo-NF-κB p65 proteins decreased after exposure to CNPs 54.4 µg/mL for 48 hours. Additionally, the Bax/Bcl-2 ratio increased, whereas the expression of Bax itself was not significantly altered. CNPs inhibit the growth of retinoblastoma and induce apoptosis in retinoblastoma cells in mice.Conclusion: CNPs inhibit the growth of retinoblastoma in mouse xenograft model by inducing apoptosis in SO-Rb 50 cells, which may be related to the increased Bax/Bcl-2 ratio and the inhibition of NF-κB. CNPs may represent a potential alternative treatment for retinoblastoma.Keywords: apoptosis, SO-Rb 50 cells, poly(ethylene glycol)-block-poly(ε-caprolactone), nanopolymeric micelles, celastrol nanoparticles&nbsp

    A targeted next-generation sequencing method for identifying clinically relevant mutation profiles in lung adenocarcinoma

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    Molecular profiling of lung cancer has become essential for prediction of an individual’s response to targeted therapies. Next-generation sequencing (NGS) is a promising technique for routine diagnostics, but has not been sufficiently evaluated in terms of feasibility, reliability, cost and capacity with routine diagnostic formalin-fixed, paraffin-embedded (FFPE) materials. Here, we report the validation and application of a test based on Ion Proton technology for the rapid characterisation of single nucleotide variations (SNVs), short insertions and deletions (InDels), copy number variations (CNVs), and gene rearrangements in 145 genes with FFPE clinical specimens. The validation study, using 61 previously profiled clinical tumour samples, showed a concordance rate of 100% between results obtained by NGS and conventional test platforms. Analysis of tumour cell lines indicated reliable mutation detection in samples with 5% tumour content. Furthermore, application of the panel to 58 clinical cases, identified at least one actionable mutation in 43 cases, 1.4 times the number of actionable alterations detected by current diagnostic tests. We demonstrated that targeted NGS is a cost-effective and rapid platform to detect multiple mutations simultaneously in various genes with high reproducibility and sensitivity

    Self‐Assembly of Therapeutic Peptide into Stimuli‐Responsive Clustered Nanohybrids for Cancer‐Targeted Therapy

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    Clinical translation of therapeutic peptides, particularly those targeting intracellular protein–protein interactions (PPIs), has been hampered by their inefficacious cellular internalization in diseased tissue. Therapeutic peptides engineered into nanostructures with stable spatial architectures and smart disease targeting ability may provide a viable strategy to overcome the pharmaceutical obstacles of peptides. This study describes a strategy to assemble therapeutic peptides into a stable peptide–Au nanohybrid, followed by further self‐assembling into higher‐order nanoclusters with responsiveness to tumor microenvironment. As a proof of concept, an anticancer peptide termed β‐catenin/Bcl9 inhibitors is copolymerized with gold ion and assembled into a cluster of nanohybrids (pCluster). Through a battery of in vitro and in vivo tests, it is demonstrated that pClusters potently inhibit tumor growth and metastasis in several animal models through the impairment of the Wnt/β‐catenin pathway, while maintaining a highly favorable biosafety profile. In addition, it is also found that pClusters synergize with the PD1/PD‐L1 checkpoint blockade immunotherapy. This new strategy of peptide delivery will likely have a broad impact on the development of peptide‐derived therapeutic nanomedicine and reinvigorate efforts to discover peptide drugs that target intracellular PPIs in a great variety of human diseases, including cancer.A strategy for clinical translation of therapeutic peptides by assembling them into a stable peptide–Au nanohybrid, followed by further self‐assembling into higher‐order nanoclusters with responsiveness to the tumor microenvironment, is presented. An anticancer peptide termed β‐catenin/Bcl9 inhibitor is assembled into a cluster of nanohybrids termed pCluster, which potently inhibits tumor growth as well as metastasis, and synergizes with immunotherapy, while maintaining a highly favorable biosafety profile.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/148246/1/adfm201807736.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/148246/2/adfm201807736-sup-0001-S1.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/148246/3/adfm201807736_am.pd
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