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1.
Small ; : e2401432, 2024 May 31.
Article in English | MEDLINE | ID: mdl-38818686

ABSTRACT

Colloidal composites, translating the great potential of nanoscale building bricks into macroscopic dimensions, have emerged as an appealing candidate for new materials with applications in optics, energy storage, and biomedicines. However, it remains a key challenge to bridge the size regimes from nanoscopic colloidal particles to macroscale composites possessing mechanical robustness. Herein, a bottom-up approach is demonstrated to manufacture colloidal composites with customized macroscopic forms by virtue of the co-assembly of nanosized soft polymeric micelles and hard inorganic nanoparticles. Upon association, the hairy micellar corona can bind with the hard nanoparticles, linking individual hard constituents together in a soft-hard alternating manner to form a collective entity. This permits the integration of block copolymer micelles with controlled amounts of hard nanoparticles into macroscopic colloidal composites featuring diverse internal microstructures. The resultant composites showed tunable microscale mechanical strength in a range of 90-270 MPa and macroscale mechanical strength in a range of 7-42 MPa for compression and 2-24 MPa for bending. Notably, the incorporation of soft polymeric micelles also imparts time- and temperature-dependent dynamic deformability and versatile capacity to the resulting composites, allowing their application in the low-temperature plastic processing for functional fused silica glass.

2.
Respir Res ; 25(1): 215, 2024 May 20.
Article in English | MEDLINE | ID: mdl-38764025

ABSTRACT

BACKGROUND: Epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) have revolutionized the treatment of lung cancer patients with mutated EGFR. However, the efficacy of EGFR-TKIs in wild-type EGFR tumors has been shown to be marginal. Methods that can sensitize EGFR-TKIs to EGFR wild-type NSCLC remain rare. Hence, we determined whether combination treatment can maximize the therapeutic efficacy of EGFR-TKIs. METHODS: We established a focused drug screening system to investigate candidates for overcoming the intrinsic resistance of wild-type EGFR NSCLC to EGFR-TKIs. Molecular docking assays and western blotting were used to identify the binding mode and blocking effect of the candidate compounds. Proliferation assays, analyses of drug interactions, colony formation assays, flow cytometry and nude mice xenograft models were used to determine the effects and investigate the molecular mechanism of the combination treatment. RESULTS: Betulinic acid (BA) is effective at targeting EGFR and synergizes with EGFR-TKIs (gefitinib and osimertinib) preferentially against wild-type EGFR. BA showed inhibitory activity due to its interaction with the ATP-binding pocket of EGFR and dramatically enhanced the suppressive effects of EGFR-TKIs by blocking EGFR and modulating the EGFR-ATK-mTOR axis. Mechanistic studies revealed that the combination strategy activated EGFR-induced autophagic cell death and that the EGFR-AKT-mTOR signaling pathway was essential for completing autophagy and cell cycle arrest. Activation of the mTOR pathway or blockade of autophagy by specific chemical agents markedly attenuated the effect of cell cycle arrest. In vivo administration of the combination treatment caused marked tumor regression in the A549 xenografts. CONCLUSIONS: BA is a potential wild-type EGFR inhibitor that plays a critical role in sensitizing EGFR-TKI activity. BA combined with an EGFR-TKI effectively suppressed the proliferation and survival of intrinsically resistant lung cancer cells via the inhibition of EGFR as well as the induction of autophagy-related cell death, indicating that BA combined with an EGFR-TKI may be a potential therapeutic strategy for overcoming the primary resistance of wild-type EGFR-positive lung cancers.


Subject(s)
Autophagy , Betulinic Acid , Carcinoma, Non-Small-Cell Lung , Drug Synergism , ErbB Receptors , Lung Neoplasms , Pentacyclic Triterpenes , Protein Kinase Inhibitors , Animals , Humans , Mice , A549 Cells , Acrylamides/pharmacology , Aniline Compounds/pharmacology , Antineoplastic Agents/pharmacology , Antineoplastic Combined Chemotherapy Protocols/pharmacology , Autophagy/drug effects , Carcinoma, Non-Small-Cell Lung/drug therapy , Carcinoma, Non-Small-Cell Lung/pathology , Carcinoma, Non-Small-Cell Lung/metabolism , Cell Line, Tumor , ErbB Receptors/metabolism , ErbB Receptors/antagonists & inhibitors , Gefitinib/pharmacology , Indoles , Lung Neoplasms/drug therapy , Lung Neoplasms/pathology , Lung Neoplasms/metabolism , Mice, Inbred BALB C , Mice, Nude , Molecular Docking Simulation , Protein Kinase Inhibitors/pharmacology , Pyrimidines , Signal Transduction/drug effects , Triterpenes/pharmacology , Xenograft Model Antitumor Assays/methods
4.
IEEE Trans Image Process ; 33: 2404-2418, 2024.
Article in English | MEDLINE | ID: mdl-38517711

ABSTRACT

Image Quality Assessment (IQA) is a fundamental task in computer vision that has witnessed remarkable progress with deep neural networks. Inspired by the characteristics of the human visual system, existing methods typically use a combination of global and local representations (i.e., multi-scale features) to achieve superior performance. However, most of them adopt simple linear fusion of multi-scale features, and neglect their possibly complex relationship and interaction. In contrast, humans typically first form a global impression to locate important regions and then focus on local details in those regions. We therefore propose a top-down approach that uses high-level semantics to guide the IQA network to focus on semantically important local distortion regions, named as TOPIQ. Our approach to IQA involves the design of a heuristic coarse-to-fine network (CFANet) that leverages multi-scale features and progressively propagates multi-level semantic information to low-level representations in a top-down manner. A key component of our approach is the proposed cross-scale attention mechanism, which calculates attention maps for lower level features guided by higher level features. This mechanism emphasizes active semantic regions for low-level distortions, thereby improving performance. TOPIQ can be used for both Full-Reference (FR) and No-Reference (NR) IQA. We use ResNet50 as its backbone and demonstrate that TOPIQ achieves better or competitive performance on most public FR and NR benchmarks compared with state-of-the-art methods based on vision transformers, while being much more efficient (with only  âˆ¼ 13% FLOPS of the current best FR method). Codes are released at https://github.com/chaofengc/IQA-PyTorch.

5.
J Hazard Mater ; 476: 134930, 2024 Sep 05.
Article in English | MEDLINE | ID: mdl-38901258

ABSTRACT

Microorganisms can colonize to the surface of microplastics (MPs) to form biofilms, termed "plastisphere", which could significantly change their physiochemical properties and ecological roles. However, the biofilm characteristics and the deep mechanisms (interaction, assembly, and biogeochemical cycles) underlying plastisphere in wetlands currently lack a comprehensive perspective. In this study, in situ biofilm formation experiments were performed in a park with different types of wetlands to examine the plastisphere by extrinsic addition of PVC MPs in summer and winter, respectively. Results from the spectroscopic and microscopic analyses revealed that biofilms attached to the MPs in constructed forest wetlands contained the most abundant biomass and extracellular polymeric substances. Meanwhile, data from the high-throughput sequencing showed lower diversity in plastisphere compared with soil bacterial communities. Network analysis suggested a simple and unstable co-occurrence pattern in plastisphere, and the null model indicated increased deterministic process of heterogeneous selection for its community assembly. Based on the quantification of biogeochemical cycling genes by high-throughput qPCR, the relative abundances of genes involving in carbon degradation, carbon fixation, and denitrification were significantly higher in plastisphere than those of soil communities. This study greatly enhanced our understanding of biofilm formation and ecological effects of MPs in freshwater wetlands.


Subject(s)
Bacteria , Biofilms , Fresh Water , Wetlands , Biofilms/growth & development , Bacteria/genetics , Bacteria/classification , Bacteria/metabolism , Fresh Water/microbiology , Microplastics , Soil Microbiology , Microbiota , Water Pollutants, Chemical/analysis
6.
Zookeys ; 1193: 145-160, 2024.
Article in English | MEDLINE | ID: mdl-38487668

ABSTRACT

The genus Svistella Gorochov, 1987 includes 10 species from Asia, with nine documented in China. In this study, a new species, Svistellayayun He, sp. nov., is described from Xizang, China. Morphologically, it resembles S.rufonotata (Chopard, 1932) but can be distinguished by a smaller inner tympanum, dark-brown setae on the 5th segment of the maxillary palp, and a rounded apex on the ectoparamere. To validate our morphological inferences and support the description of S.yayunsp. nov. as a new species, we performed a PCA based on bioacoustics parameters and molecular analysis. All Svistella species documented in China are distinguished by integrating their songs and DNA barcoding.

7.
Drug Dev Ind Pharm ; 39(8): 1187-96, 2013 Aug.
Article in English | MEDLINE | ID: mdl-22803692

ABSTRACT

Here we report the application of solid dispersion (SD) technique to improve paclitaxel (PTX) release from poly(ϵ-caprolactone) (PCL)-based film. Paclitaxel solid dispersions (SDs) with either poloxamer188 (PXM) or polyethylene glycol (PEG) were successfully prepared by a melting method and then incorporated into PCL films, which were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), differential scanning calorimetry (DSC) and In vitro drug release/dissolution studies. It was found that PTX was faster released from the SDs than the corresponding physical mixtures (PMs) or PTX alone. For the PCL films with almost the same PTX loading, drug release from films containing SDs was remarkably faster than that from the film directly incorporated with PTX particles, and the films containing SDs with PXM exhibited a faster drug release than those with PEG. An increase In the content of PXM had no significant influence on PTX release from the films containing SDs. Incorporation of a higher content of SDs led to slower drug release from PCL films, indicating that PTX loading had a dominating effect on drug release. Through this study, we demonstrated the feasibility of the application of SD technique on the improvement of PTX release from PCL films and offered some beneficial information on modulating drug release behavior by changing the compositions and contents of the SDs-loaded PCL films.


Subject(s)
Antineoplastic Agents, Phytogenic/administration & dosage , Paclitaxel/administration & dosage , Poloxamer/administration & dosage , Polyesters/administration & dosage , Polyethylene Glycols/administration & dosage , Calorimetry, Differential Scanning , Delayed-Action Preparations , Paclitaxel/chemistry , Solubility
8.
Article in English | MEDLINE | ID: mdl-37647188

ABSTRACT

Deep learning approaches for Image Aesthetics Assessment (IAA) have shown promising results in recent years, but the internal mechanisms of these models remain unclear. Previous studies have demonstrated that image aesthetics can be predicted using semantic features, such as pre-trained object classification features. However, these semantic features are learned implicitly, and therefore, previous works have not elucidated what the semantic features are representing. In this work, we aim to create a more transparent deep learning framework for IAA by introducing explainable semantic features. To achieve this, we propose Tag-based Content Descriptors (TCDs), where each value in a TCD describes the relevance of an image to a human-readable tag that refers to a specific type of image content. This allows us to build IAA models from explicit descriptions of image contents. We first propose the explicit matching process to produce TCDs that adopt predefined tags to describe image contents. We show that a simple MLP-based IAA model with TCDs only based on predefined tags can achieve an SRCC of 0.767, which is comparable to most state-of-the-art methods. However, predefined tags may not be sufficient to describe all possible image contents that the model may encounter. Therefore, we further propose the implicit matching process to describe image contents that cannot be described by predefined tags. By integrating components obtained from the implicit matching process into TCDs, the IAA model further achieves an SRCC of 0.817, which significantly outperforms existing IAA methods. Both the explicit matching process and the implicit matching process are realized by the proposed TCD generator. To evaluate the performance of the proposed TCD generator in matching images with predefined tags, we also labeled 5101 images with photography-related tags to form a validation set. And experimental results show that the proposed TCD generator can meaningfully assign photography-related tags to images.

9.
IEEE J Biomed Health Inform ; 27(7): 3360-3371, 2023 Jul.
Article in English | MEDLINE | ID: mdl-37099473

ABSTRACT

In recent years, there has been significant progress in polyp segmentation in white-light imaging (WLI) colonoscopy images, particularly with methods based on deep learning (DL). However, little attention has been paid to the reliability of these methods in narrow-band imaging (NBI) data. NBI improves visibility of blood vessels and helps physicians observe complex polyps more easily than WLI, but NBI images often include polyps with small/flat appearances, background interference, and camouflage properties, making polyp segmentation a challenging task. This paper proposes a new polyp segmentation dataset (PS-NBI2K) consisting of 2,000 NBI colonoscopy images with pixel-wise annotations, and presents benchmarking results and analyses for 24 recently reported DL-based polyp segmentation methods on PS-NBI2K. The results show that existing methods struggle to locate polyps with smaller sizes and stronger interference, and that extracting both local and global features improves performance. There is also a trade-off between effectiveness and efficiency, and most methods cannot achieve the best results in both areas simultaneously. This work highlights potential directions for designing DL-based polyp segmentation methods in NBI colonoscopy images, and the release of PS-NBI2K aims to drive further development in this field.


Subject(s)
Colonic Polyps , Humans , Colonic Polyps/diagnostic imaging , Reproducibility of Results , Benchmarking , Colonoscopy/methods , Narrow Band Imaging/methods
10.
Exp Parasitol ; 131(4): 442-7, 2012 Aug.
Article in English | MEDLINE | ID: mdl-22705923

ABSTRACT

This work reports the prevention outcomes of a praziquantel (PZQ) implant against the infection of Schistosoma japonicum in mice. The PZQ implant produced stable plasma PZQ concentrations in a range of 100-1300 ng/mL for a period of 70 days, by releasing PZQ in subcutaneous tissues in a sustained manner. To assess the prevention effects, the mice were infected at varying times after implantation. All the mice were sacrificed at 6 weeks after infection for worm and egg recovery and counting, worm morphological examination, determination of egg-hatching rates, and analysis of hepatic histology. The infection was successfully prevented for mice with early infection times (within 2-3 weeks), as nearly no worms, paired worms, eggs, or miracidia were recovered. However, in mice with late infection times (after 3 weeks), the prevention effects were diminished due to the decreased plasma PZQ concentrations at late times. Interestingly, the implants showed robust prevention effects on repeated infection at 1 and 3 weeks. In the infection-prevented mouse livers, no granuloma formation or granulomatous inflammation was observed. The results demonstrated that by blocking the development of infecting miracidia and by deactivating the eggs, the PZQ implants encouragingly prevented the S. japonicum infection and avoided liver damage.


Subject(s)
Anthelmintics/administration & dosage , Praziquantel/administration & dosage , Schistosomiasis japonica/prevention & control , Animals , Anthelmintics/blood , Drug Implants , Female , Liver/parasitology , Liver/pathology , Male , Mice , Microscopy, Electron, Scanning , Praziquantel/blood , Random Allocation , Schistosoma japonicum/drug effects , Schistosoma japonicum/ultrastructure , Time Factors
11.
Nanoscale Adv ; 4(16): 3323-3329, 2022 Aug 11.
Article in English | MEDLINE | ID: mdl-36131715

ABSTRACT

Voltage controlled magnetic anisotropy (VCMA) has been considered as an effective method in traditional magnetic devices with lower power consumption. In this article, we have investigated the dual-axis control of magnetic anisotropy in Co2MnSi/GaAs/PZT hybrid heterostructures through piezo-voltage-induced strain using longitudinal magneto-optical Kerr effect (LMOKE) microscopy. The major modification of in-plane magnetic anisotropy of the Co2MnSi thin film is controlled obviously by the piezo-voltages of the lead zirconate titanate (PZT) piezotransducer, accompanied by the coercivity field and magnetocrystalline anisotropy significantly manipulated. Because in-plane cubic magnetic anisotropy and uniaxial magnetic anisotropy coexist in the Co2MnSi thin film, the initial double easy axes of cubic split to an easiest axis (square loop) and an easier axis (two-step loop). While the stress direction is parallel to the [1-10] easiest axis (sample I), the square loop of the [1-10] direction could transform to a two-step loop under the negative piezo-voltages (compressed state). At the same time, the initial two-step loop of the [110] axis simultaneously changes to a square loop (the easiest axis). Otherwise, we designed and fabricated the sample II in which the PZT stress is parallel to the [110] two-step axis. The phenomenon of VCMA was also obtained along the [110] and [1-10] directions. However, the manipulated results of sample II were in contrast to those of the sample I under the piezo-voltages. Thus, an effective dual-axis regulation of the in-plane magnetization rotation was demonstrated in this work. Such a finding proposes a more optimized method for the magnetic logic gates and memories based on voltage-controlled magnetic anisotropy in the future.

12.
J Mater Sci Mater Med ; 22(2): 327-37, 2011 Feb.
Article in English | MEDLINE | ID: mdl-21221735

ABSTRACT

The ethylene vinyl acetate copolymer (EVA)/Poly (lactic acid) (PLA) blend and EVA/Poly (ethylene glycol) (PEG) blend were applied as the drug carrier materials for a bi-layer drug-loaded stent coating film, which consisted of a paclitaxel (PTX)-loaded layer and a drug-free EVA layer. The changes of weight and appearance of the drug-free polymeric blend films with increasing time were examined by X-ray diffraction analysis (XRD), gel permeation chromatography (GPC) tests and scanning electronic microscopy (SEM), and the results showed the degradation of PLA and the leaching of PEG from the films. The effects of PLA, PEG and drug contents on in vitro drug release were investigated, and the results demonstrated that the addition of PLA promoted the drug release while the addition of PEG almost did not. Franz cells diffusion test results indicated that the bi-layer structure successfully endowed the stent coating with the release of drug in a unidirectional fashion. The release profiles of films incorporated PTX and the mechanical performance of the film could be customized by readily adjusting the contents of the blend components. Therefore, the polymeric blends could be useful drug carrier materials for drug-loaded stent coating capable of releasing drug in a highly tunable manner.


Subject(s)
Coated Materials, Biocompatible/chemistry , Lactic Acid/chemistry , Paclitaxel/administration & dosage , Polymers/chemistry , Antineoplastic Agents, Phytogenic/administration & dosage , Chromatography, Gel/methods , Chromatography, High Pressure Liquid/methods , Drug Carriers , Drug Delivery Systems , Drug-Eluting Stents , Lipid Bilayers/chemistry , Microscopy, Electron, Scanning/methods , Polyesters , Polyethylene Glycols/chemistry , Stress, Mechanical , X-Ray Diffraction
13.
Drug Dev Ind Pharm ; 37(9): 1068-75, 2011 Sep.
Article in English | MEDLINE | ID: mdl-21449700

ABSTRACT

Hydrophilic 5-fluorouracil (5-FU) loaded cylindrical poly(ε-caprolactone) (PCL) implants with different implant diameters (2, 4 and 8 mm), different drug loadings (25% and 50%) and end-capping were fabricated and characterized. The implant structure, drug content and molecular weight of PCL after 120 days drug release were investigated. The in vitro release results showed that, when the drug loading was the same, drug release was fastest for the implant with a diameter of 2 mm and slowest for the implant with a diameter of 8 mm; for the implants with the same diameters, the release of drug from the implants with 50% drug loading was faster than that from the implants with 25% drug loading; however, this effect of drug loading decreased with the increase of implant diameter; in addition, 5-FU was released slightly slower from the end-capped implants than from the corresponding uncapped implants; the drug release data for all the uncapped implants were best fit with the Ritger-Peppas model. Drug release from the hydrophobic implants was found to be dominated by diffusion mechanism. Scanning electron microscopy images and drug content measurements revealed that 5-FU release took place gradually from the exterior region to the interior region of the implants.


Subject(s)
Drug Carriers/chemistry , Drug Implants , Fluorouracil/pharmacokinetics , Polyesters/chemistry , Biological Availability , Hydrophobic and Hydrophilic Interactions , Models, Chemical
14.
Mater Sci Eng C Mater Biol Appl ; 120: 111655, 2021 Jan.
Article in English | MEDLINE | ID: mdl-33545823

ABSTRACT

Hydroxyapatite (HA) combined with antimicrobial agents for biomedical application can effectively avoid the bacteria infection, while HA have the good performance. In this study, we prepared silver-hydroxyapatite (Ag-HA) nanocomposites using a one-pot method consisting of three sequential steps of wet chemical precipitation, ion exchange, and a silver mirror reaction. The HA nanoparticles used as the precursor for Ag ion doping were first synthesised by wet chemical precipitation. Next, Ag+ absorbed on HA surface through ion exchange reaction. Glucose was then added to initiate the silver mirror reaction, which made the Ag+ ions reduce to Ag0 and Ag nanoparticles in situ formed on HA nanoparticles. Subsequently, Ag-HA nanocomposites with different Ag content were prepared. X-ray diffraction, SEM, EDX mapping and TEM imaging confirmed that spherical Ag nanoparticles ~20-40 nm in diameter were adhered to the surface of HA nano-rods (0.4-0.8 µm in length and 15-40 nm in diameter). The Ag content (1.9-15.2 wt%) in the Ag-HA nanocomposites was adjusted by varying the feeding Ag/Ca molar ratio (2.0-20%). The cell viability evaluation in vitro proved that Ag-HA nanocomposites had low cytotoxicity to L929 normal cells. Meanwhile, the antibacterial examinations in vitro demonstrated that Ag-HA nanocomposites had obvious antibacterial effects on Gram-positive bacteria, Gram-negative bacteria, and fungus. The antibacterial results were dose-dependent on the accumulation of silver content. The Ag-HA nanocomposites loaded PMMA resins also demonstrated a potential antibacterial activity against S. mutans. This paper presents a convenient and bio-friendly approach for preparing Ag-HA nanocomposites with adjustable Ag content, which are a promising material for biomedical applications.


Subject(s)
Metal Nanoparticles , Nanocomposites , Anti-Bacterial Agents/pharmacology , Durapatite , Microbial Sensitivity Tests , Silver/pharmacology
15.
Aging (Albany NY) ; 13(14): 18287-18297, 2021 07 28.
Article in English | MEDLINE | ID: mdl-34319254

ABSTRACT

BACKGROUND: To explore the effect of albiflorin (AL) on streptozotocin (STZ)-induced Alzheimer's disease (AD) in rats. METHODS: A mouse model of diabetic encephalopathy was established by intraperitoneal injection of 1%STZ. Step down test and water maze test were used to test the cognitive function of rats. Congo Red Staining was used to detect the distribution of Aß plaques in the hippocampus of rats. Cytokine levels in serum and hippocampus were measured using ELISA. Serum insulin, oral glucose tolerance (OGTT), serum superoxide dismutase (SOD) activity and malondialdehyde (MDA) content were measured by commercial kits. And the content of Nrf-2/HO-1/HMGB1/NF-kB in the hippocampus of diabetic rats were detected by western blot. RESULTS AND CONCLUSION: Compared with the STZ model group, the average escape latency of rats in the AL group in the Morris water maze test was significantly shortened, and the average number of platform crossings and the ratio of distance/total swimming distance in the target quadrant were increased significantly. Staining of tissue sections and ELISA showed a decrease in Aß plaque density in the hippocampus of rats in the AL group. And serum insulin levels of rats in the ALgroup were significantly reduced and OGTT was improved. In addition, AL could also regulate the Nrf-2/HO-1/HMGB1/NF-kB signal pathway in the hippocampus. Therefore, AL may ameliorate STZ-induced cognitive impairment in rats by regulating oxidative stress and inflammation in the brain.


Subject(s)
Bridged-Ring Compounds/pharmacology , Cognitive Dysfunction/drug therapy , Cognitive Dysfunction/etiology , Diabetes Mellitus, Experimental/complications , Animals , Cognitive Dysfunction/pathology , Diabetes Mellitus, Experimental/metabolism , HMGB1 Protein/metabolism , Hippocampus/drug effects , Hippocampus/metabolism , Male , Malondialdehyde/metabolism , Maze Learning/drug effects , NF-kappa B/metabolism , Oxidative Stress/drug effects , Plaque, Amyloid/pathology , Rats , Rats, Wistar , Signal Transduction/drug effects , Streptozocin/toxicity
16.
Int J Biol Macromol ; 193(Pt A): 768-777, 2021 Dec 15.
Article in English | MEDLINE | ID: mdl-34717982

ABSTRACT

It is well known that metal ions have great effects on gelling behaviors of gellan aqueous systems, however, the effects of their co-ions - anions have rarely been studied. Herein, we investigated the effects of four kinds of sodium salts with different anions (NaCl, CH3COONa, Na2C2O4 and Na3C6H5O7) on gelling behaviors of gellan aqueous systems in terms of gelling temperature and gel hardness. It was found that, when [Na+] was low (20 mM), the salt with Cl- or CH3COO- favored the gelling of gellan aqueous systems, while the salt with C2O42- or C6H5O73- took adverse effects probably because C2O42- or C6H5O73- could react with divalent cations (Ca2+ and Mg2+) in gellan to form precipitates or chelates and break their interactions with gellan (salt bridges). When [Na+] was high (50 or 80 mM), all the four kinds of salts facilitated gelling due to the shielding effects of high concentrations of Na+ on the negative charges along the gellan chains, and followed the order of: Cl- > CH3COO- > C2O42- > C6H5O73-. This study demonstrates the effects of anion kind of salts on gelling behaviors of gellan aqueous systems and provides references for the application of gellan.


Subject(s)
Gels/chemistry , Ions/chemistry , Polysaccharides, Bacterial/chemistry , Salts/chemistry , Sodium , Temperature , Water
17.
Nat Commun ; 12(1): 1739, 2021 03 19.
Article in English | MEDLINE | ID: mdl-33741959

ABSTRACT

Extensive testing is essential to break the transmission of SARS-CoV-2, which causes the ongoing COVID-19 pandemic. Here, we present a CRISPR-based diagnostic assay that is robust to viral genome mutations and temperature, produces results fast, can be applied directly on nasopharyngeal (NP) specimens without RNA purification, and incorporates a human internal control within the same reaction. Specifically, we show that the use of an engineered AsCas12a enzyme enables detection of wildtype and mutated SARS-CoV-2 and allows us to perform the detection step with loop-mediated isothermal amplification (LAMP) at 60-65 °C. We also find that the use of hybrid DNA-RNA guides increases the rate of reaction, enabling our test to be completed within 30 minutes. Utilizing clinical samples from 72 patients with COVID-19 infection and 57 healthy individuals, we demonstrate that our test exhibits a specificity and positive predictive value of 100% with a sensitivity of 50 and 1000 copies per reaction (or 2 and 40 copies per microliter) for purified RNA samples and unpurified NP specimens respectively.


Subject(s)
COVID-19 Testing/methods , COVID-19/diagnosis , RNA, Guide, Kinetoplastida , SARS-CoV-2/genetics , Bacterial Proteins/genetics , COVID-19/virology , CRISPR-Associated Proteins/genetics , CRISPR-Cas Systems , Clustered Regularly Interspaced Short Palindromic Repeats , Endodeoxyribonucleases/genetics , Humans , Molecular Diagnostic Techniques/methods , Mutation , Nasopharynx/virology , Nucleic Acid Amplification Techniques/methods , RNA, Viral/genetics , Sensitivity and Specificity
18.
Int J Biol Markers ; 35(4): 12-19, 2020 Dec.
Article in English | MEDLINE | ID: mdl-33126828

ABSTRACT

OBJECTIVE: This study aimed to comprehensively investigate the correlation of ERCC1 expression and chemosensitivity of ovarian cancer. METHODS: The literature on the relationship between the excision repair cross complementary gene 1 (ERCC1) and the chemosensitivity of ovarian cancer published in PubMed, Web of Science, EMBASE, CNKI, and the China Wanfang database from the establishment of the databases to June 2020 were searched. Chemosensitivity is evaluated by clinical effective rate (complete remission plus partial remission). Statistical analysis was carried out by using Stata 15.1 software. RESULTS: A total of 11 articles met the inclusion criteria, consisting of 758 patients with ovarian cancer. The results showed a significant difference in chemosensitivity between the low expression group and the high expression group of ERCC1 (odds ratio 4.23; 95% confidence interval 2.96, 6.06; P < 0. 01). The same result was shown in the ethnicity subgroup. CONCLUSION: The chemosensitivity of ovarian cancer patients with a low expression of ERCC1 is better than that of patients with a high expression.


Subject(s)
DNA-Binding Proteins/metabolism , Endonucleases/metabolism , Ovarian Neoplasms/genetics , Platinum/therapeutic use , Female , Humans , Ovarian Neoplasms/pathology , Platinum/pharmacology
19.
Huan Jing Ke Xue ; 41(11): 5133-5142, 2020 Nov 08.
Article in Zh | MEDLINE | ID: mdl-33124257

ABSTRACT

There are many sites contaminated by polycyclic aromatic hydrocarbons (PAHs) or combined PAHs-heavy metal in China, which pose serious health-risks to local people and environments. Dissipative quartz crystal microbalance (QCM-D) was applied to investigate the adsorption of naphthalene to two organic-modified smectite clays (cetyltrimethyl ammonium bromide modified montmorillonite, CTAB-SMF, and 3-mercapto propyl trimethoxy silane modified montmorillonite, TMSP-SMF) and original SMF, together with batch adsorption experiments. The results, based on in-situ online QCM-D experiments, showed that the adsorption sites of CTAB-SMF on naphthalene were mainly CTAB grouped between the interlayers of clay particles, while TMSP-SMF's were TMSP grouped on the surfaces of clay particles. The isotherms of naphthalene adsorption to CTAB-SMF fitted well (R2>0.92) with the Freundlich model, while the adsorption isotherms to TMSP-SMF and SMF fitted well with the Langmuir model (R2>0.96). The parameters of CTAB-SMF (n>1) indicated that the adsorption sites of naphthalene to CTAB-SMF were heterogeneous and the adsorption increases at higher equilibrium concentration. The adsorption capacity qmax of TMSP-SMF is significantly greater than that of SMF (P<0.05). Based on the calculation, the value of ΔHobs for these three clays (CTAB-SMF, TMSP-SMF, and SMF) were within the range of -30 to -10 kJ·mol-1, which indicated that it was a spontaneous exothermic physical process. The solution ionic strength could decrease the adsorption of naphthalene to SMF, but had limited effects on naphthalene adsorption to the two organo-modified clay particles. The existence of Cu2+ in the solution could enhance naphthalene adsorption to the three particles, and naphthalene could improve Cu2+ adsorption to these two modified clays. The results of this study show that QCM-D is a useful technique to indicate the changes of clay film during the process of adsorption, and the two organo-modified clay particles have the potential to be remediation materials to remediate PAHs or PAHs-heavy metal-contaminated sites.


Subject(s)
Bentonite , Polycyclic Aromatic Hydrocarbons , Adsorption , China , Humans , Naphthalenes
20.
Int J Biol Macromol ; 159: 659-666, 2020 Sep 15.
Article in English | MEDLINE | ID: mdl-32439451

ABSTRACT

The moisture sorption and desorption properties of hard capsules have a great influence on the quality of capsule products. However, studies on them have rarely been reported. Herein, we studied the moisture sorption and desorption properties of three kinds of hard capsules (gelatin, hydroxypropyl methyl cellulose (HPMC) and pullulan capsules) in terms of hygroscopicity, crystallinity, thermal behaviors and so on. It is found that HPMC capsules have weaker moisture sorption ability and moisture keeping ability than pullulan or gelatin capsules with lower moisture sorption rates, equilibrium moisture contents, moisture keeping rates and higher critical relative humidity. In comparison with gelatin capsules, pullulan capsules have weaker moisture sorption ability and comparable moisture keeping ability. HPMC or pullulan capsules can more effectively protect high, moderate and low hygroscopic capsule contents (chitosan, potato starch or ethyl cellulose) from outside moisture absorption. The diffraction peaks of the moisture equilibrated gelatin, HPMC and pullulan capsules are much smaller than those of their dried ones. The dried and the moisture equilibrated gelatin, HPMC or pullulan capsules all have smooth surface morphology. HPMC or pullulan capsules can be an attractive alternative to animal gelatin capsules due to their appropriate moisture sorption and desorption properties.


Subject(s)
Capsules/chemistry , Gelatin/chemistry , Glucans/chemistry , Hypromellose Derivatives/chemistry , Water/analysis , Calorimetry, Differential Scanning , Capsules/analysis , Chitosan/chemistry , Gelatin/analysis , Glucans/analysis , Hypromellose Derivatives/analysis , Starch/chemistry , Surface Properties , X-Ray Diffraction
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