GLORIA

GEOMAR Library Ocean Research Information Access

X

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
Filter
  • MDPI AG  (2,147)
Material
Publisher
  • MDPI AG  (2,147)
Person/Organisation
Language
Years
FID
  • 1
    Online Resource
    Online Resource
    Design and Synthesis of Novel Podophyllotoxins Hybrids and the Effects of Different Functional Groups on Cytotoxicity
    MDPI AG ; 2021
    In:  Molecules Vol. 27, No. 1 ( 2021-12-30), p. 220-
    Details
    In: Molecules, MDPI AG, Vol. 27, No. 1 ( 2021-12-30), p. 220-
    Abstract: Development of novel anticancer therapeutic candidates is one of the key challenges in medicinal chemistry. Podophyllotoxin and its derivatives, as a potent cytotoxic agent, have been at the center of extensive chemical amendment and pharmacological investigation. Herein, a new series of podophyllotoxin-N-sulfonyl amidine hybrids (4a–4v, 5a–5f) were synthesized by a CuAAC/ring-opening procedure. All the synthesized podophyllotoxins derivatives were evaluated for in vitro cytotoxic activity against a panel of human lung (A-549) cancer cell lines. Different substituents’, or functional groups’ antiproliferative activities were discussed. The –CF3 group performed best (IC50: 1.65 μM) and exhibited more potent activity than etoposide. Furthermore, molecular docking and dynamics studies were also conducted for active compounds and the results were in good agreement with the observed IC50 values.
    Type of Medium: Online Resource
    ISSN: 1420-3049
    URL: Article
    DOI: 10.3390/molecules27010220
    Language: English
    Publisher: MDPI AG
    Publication Date: 2021
    detail.hit.zdb_id: 2008644-1
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    Online Resource
  • 2
    Online Resource
    Online Resource
    Role of Mn2+ Doping in the Preparation of Core-Shell Structured Fe3O4@upconversion Nanoparticles and Their Applications in T1/T2-Weighted Magnetic Resonance Imaging, Upconversion Luminescent Imaging and Near-Infrared Activated Photodynamic Therapy
    MDPI AG ; 2018
    In:  Nanomaterials Vol. 8, No. 7 ( 2018-06-26), p. 466-
    Details
    In: Nanomaterials, MDPI AG, Vol. 8, No. 7 ( 2018-06-26), p. 466-
    Type of Medium: Online Resource
    ISSN: 2079-4991
    URL: Article
    DOI: 10.3390/nano8070466
    Language: English
    Publisher: MDPI AG
    Publication Date: 2018
    detail.hit.zdb_id: 2662255-5
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    Online Resource
  • 3
    Online Resource
    Online Resource
    DGS-HSA: A Dummy Generation Scheme Adopting Hierarchical Structure of the Address
    MDPI AG ; 2020
    In:  Applied Sciences Vol. 10, No. 2 ( 2020-01-11), p. 548-
    Details
    In: Applied Sciences, MDPI AG, Vol. 10, No. 2 ( 2020-01-11), p. 548-
    Abstract: With the increasing convenience of location-based services (LBSs), there have been growing concerns about the risk of privacy leakage. We show that existing techniques fail to defend against a statistical attack meant to infer the user’s location privacy and query privacy, which is due to continuous queries that the same user sends in the same location in a short time, causing the user’s real location to appear consecutively more than once and the query content to be the same or similar in the neighboring query. They also fail to consider the hierarchical structure of the address, so locations in an anonymous group may be located in the same organization, resulting in leaking of the user’s organization information and reducing the privacy protection effect. This paper presents a dummy generation scheme, considering the hierarchical structure of the address (DGS-HSA). In our scheme, we introduce a novel meshing method, which divides the historical location dataset according to the administrative region division. We also choose dummies from the historical location dataset with the two-level grid structure to realize the protection of the user’s location, organization information, and query privacy. Moreover, we prove the feasibility of the presented scheme by solving the multi-objective optimization problem and give the user’s privacy protection parameters recommendation settings, which balance the privacy protection level and system overhead. Finally, we evaluate the effectiveness and the correctness of the DGS-HSA through theoretical analysis and extensive simulations.
    Type of Medium: Online Resource
    ISSN: 2076-3417
    URL: Article
    DOI: 10.3390/app10020548
    Language: English
    Publisher: MDPI AG
    Publication Date: 2020
    detail.hit.zdb_id: 2704225-X
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    Online Resource
  • 4
    Online Resource
    Online Resource
    Efficient Removal of Antimony(III) in Aqueous Phase by Nano-Fe3O4 Modified High-Iron Red Mud: Study on Its Performance and Mechanism
    MDPI AG ; 2021
    In:  Water Vol. 13, No. 6 ( 2021-03-16), p. 809-
    Details
    In: Water, MDPI AG, Vol. 13, No. 6 ( 2021-03-16), p. 809-
    Abstract: The resource utilization of excess red mud produced from aluminum production is a current research focus. In this study, novel nano-Fe3O4 modified high-iron red mud material (HRM@nFe3O4) was fabricated using the method of co-precipitation to remove Sb(III) from the aqueous phase. The HRM@nFe3O4 at a nFe3O4:HRM mass ratio of 1:1 had optimal adsorbing performance on Sb(III) in water. Compared with others, the synthetic HRM@nFe3O4 sorbent had a superior maximum Sb(III) adsorption capacity of 98.03 mg·g−1, as calculated by the Langmuir model, and a higher specific surface area of 171.63 m2·g−1, measured using the Brunauer-Emmett-Teller measurement. The adsorption process was stable at an ambient pH range, and negligibly limited by temperature the coexisting anions, except for silicate and phosphate, suggesting the high selectivity toward Sb(III). HRM@nFe3O4 retained more than 60% of the initial adsorption efficiency after the fifth adsorption-desorption cycle. The kinetic data fitted by the pseudo-second-order model illustrated the existence of a chemical adsorption process in the adsorption of Sb(III). Further mechanism analysis results indicated that the complexation reaction played a major role in Sb(III) adsorption by HRM@nFe3O4. This HRM@nFe3O4 adsorbent provides an effective method for the removal of Sb(III) in wastewater treatment and is valuable in the reclamation of red mud.
    Type of Medium: Online Resource
    ISSN: 2073-4441
    URL: Article
    DOI: 10.3390/w13060809
    Language: English
    Publisher: MDPI AG
    Publication Date: 2021
    detail.hit.zdb_id: 2521238-2
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    Online Resource
  • 5
    Online Resource
    Online Resource
    ShrewdAttack: Low Cost High Accuracy Model Extraction
    MDPI AG ; 2023
    In:  Entropy Vol. 25, No. 2 ( 2023-02-02), p. 282-
    Details
    In: Entropy, MDPI AG, Vol. 25, No. 2 ( 2023-02-02), p. 282-
    Abstract: Machine learning as a service (MLaaS) plays an essential role in the current ecosystem. Enterprises do not need to train models by themselves separately. Instead, they can use well-trained models provided by MLaaS to support business activities. However, such an ecosystem could be threatened by model extraction attacks—an attacker steals the functionality of a trained model provided by MLaaS and builds a substitute model locally. In this paper, we proposed a model extraction method with low query costs and high accuracy. In particular, we use pre-trained models and task-relevant data to decrease the size of query data. We use instance selection to reduce query samples. In addition, we divided query data into two categories, namely low-confidence data and high-confidence data, to reduce the budget and improve accuracy. We then conducted attacks on two models provided by Microsoft Azure as our experiments. The results show that our scheme achieves high accuracy at low cost, with the substitution models achieving 96.10% and 95.24% substitution while querying only 7.32% and 5.30% of their training data on the two models, respectively. This new attack approach creates additional security challenges for models deployed on cloud platforms. It raises the need for novel mitigation strategies to secure the models. In future work, generative adversarial networks and model inversion attacks can be used to generate more diverse data to be applied to the attacks.
    Type of Medium: Online Resource
    ISSN: 1099-4300
    URL: Article
    DOI: 10.3390/e25020282
    Language: English
    Publisher: MDPI AG
    Publication Date: 2023
    detail.hit.zdb_id: 2014734-X
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    Online Resource
  • 6
    Online Resource
    Online Resource
    Rhododendron molle G. Don Extract Induces Apoptosis and Inhibits Migration in Human Colorectal Cancer Cells and Potential Anticancer Components Analysis
    MDPI AG ; 2021
    In:  Molecules Vol. 26, No. 10 ( 2021-05-18), p. 2990-
    Details
    In: Molecules, MDPI AG, Vol. 26, No. 10 ( 2021-05-18), p. 2990-
    Abstract: Rhododendron molle G. Don is one example of traditional Chinese medicine with important medicinal value. In this study, the effects of methanol extract of R. molle leaves (RLE) on colorectal cancer HT-29 cells and its potential molecular mechanism were investigated. MTT analysis showed that RLE could significantly inhibit the cell viability and migration of HT-29 cells in a concentration-dependent manner. Cell cycle analyses via flow cytometer suggested that RLE induced DNA fragmentation, indicative of apoptosis, and arrest at the S phase in HT-29 cells. Quantitative real-time PCR (qRT-PCR) analysis showed that RLE could upregulate the mRNA expression of p53 and p21 in HT-29 cells, which would result in HT-29 cells being blocked in S phase. Meanwhile, RLE could upregulate the expression of Bax, and downregulate the expression of Bcl-2, which would induce cell apoptosis. Further western blot analysis showed that the protein expression changes of Bax and P53 were basically consistent with the results of qRT-PCR. In addition, GC-MS analysis detected 17 potential anticancer components in R. molle. These results indicate that R. molle has significant anticancer activity, which provides some useful information for further study and clinical application for R. molle.
    Type of Medium: Online Resource
    ISSN: 1420-3049
    URL: Article
    DOI: 10.3390/molecules26102990
    Language: English
    Publisher: MDPI AG
    Publication Date: 2021
    detail.hit.zdb_id: 2008644-1
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    Online Resource
  • 7
    Online Resource
    Online Resource
    An Oxidant-Free and Mild Strategy for Quinazolin-4(3H)-One Synthesis via CuAAC/Ring Cleavage Reaction
    MDPI AG ; 2023
    In:  Molecules Vol. 28, No. 15 ( 2023-07-28), p. 5734-
    Details
    In: Molecules, MDPI AG, Vol. 28, No. 15 ( 2023-07-28), p. 5734-
    Abstract: An oxidant-free and highly efficient synthesis of phenolic quinazolin-4(3H)-ones was achieved by simply stirring a mixture of 2-aminobenzamides, sulfonyl azides, and terminal alkynes. The intermediate N-sulfonylketenimine underwent two nucleophilic additions and the sulfonyl group eliminated through the power of aromatization. The natural product 2-(4-hydroxybenzyl)quinazolin-4(3H)-one can be synthesized on a large scale under mild conditions with this method.
    Type of Medium: Online Resource
    ISSN: 1420-3049
    URL: Article
    DOI: 10.3390/molecules28155734
    Language: English
    Publisher: MDPI AG
    Publication Date: 2023
    detail.hit.zdb_id: 2008644-1
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    Online Resource
  • 8
    Online Resource
    Online Resource
    Dihydroartemisinin Inhibits mTORC1 Signaling by Activating the AMPK Pathway in Rhabdomyosarcoma Tumor Cells
    MDPI AG ; 2021
    In:  Cells Vol. 10, No. 6 ( 2021-06-01), p. 1363-
    Details
    In: Cells, MDPI AG, Vol. 10, No. 6 ( 2021-06-01), p. 1363-
    Abstract: Dihydroartemisinin (DHA), an anti-malarial drug, has been shown to possess potent anticancer activity, partly by inhibiting the mammalian target of rapamycin (mTOR) complex 1 (mTORC1) signaling. However, how DHA inhibits mTORC1 is still unknown. Here, using rhabdomyosarcoma (RMS) as a model, we found that DHA reduced cell proliferation and viability in RMS cells, but not those in normal cells, which was associated with inhibition of mTORC1. Mechanistically, DHA did not bind to mTOR or FK506 binding protein 12 (FKBP12). In addition, DHA neither inhibited insulin-like growth factor-1 receptor (IGF-1R), phosphoinositide 3-kinase (PI3K), and extracellular signal-regulated kinase ½ (Erk1/2), nor activated phosphatase and tensin homolog (PTEN) in the cells. Rather, DHA activated AMP-activated protein kinase (AMPK). Pharmacological inhibition of AMPK, ectopic expression dominant negative or kinase-dead AMPK, or knockdown of AMPKa attenuated the inhibitory effect of DHA on mTORC1 in the cells. Additionally, DHA was able to induce dissociation of regulatory-associated protein of mTOR (raptor) from mTOR and inhibit mTORC1 activity. Moreover, treatment with artesunate, a prodrug of DHA, dose-dependently inhibited tumor growth and concurrently activated AMPK and suppressed mTORC1 in RMS xenografts. The results indicated that DHA inhibits mTORC1 by activating AMPK in tumor cells. Our finding supports that DHA or artesunate has a great potential to be repositioned for treatment of RMS.
    Type of Medium: Online Resource
    ISSN: 2073-4409
    URL: Article
    DOI: 10.3390/cells10061363
    Language: English
    Publisher: MDPI AG
    Publication Date: 2021
    detail.hit.zdb_id: 2661518-6
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    Online Resource
  • 9
    Online Resource
    Online Resource
    COX-2 Deficiency Promotes White Adipogenesis via PGE2-Mediated Paracrine Mechanism and Exacerbates Diet-Induced Obesity
    MDPI AG ; 2022
    In:  Cells Vol. 11, No. 11 ( 2022-06-02), p. 1819-
    Details
    In: Cells, MDPI AG, Vol. 11, No. 11 ( 2022-06-02), p. 1819-
    Abstract: Cyclooxygenase-2 (COX-2) plays a critical role in regulating innate immunity and metabolism by producing prostaglandins (PGs) and other lipid mediators. However, the implication of adipose COX-2 in obesity remains largely unknown. Using adipocyte-specific COX-2 knockout (KO) mice, we showed that depleting COX-2 in adipocytes promoted white adipose tissue development accompanied with increased size and number of adipocytes and predisposed diet-induced adiposity, obesity, and insulin resistance. The increased size and number of adipocytes by COX-2 KO were reversed by the treatment of prostaglandin E2 (PGE2) but not PGI2 and PGD2 during adipocyte differentiation. PGE2 suppresses PPARγ expression through the PKA pathway at the early phase of adipogenesis, and treatment of PGE2 or PKA activator isoproterenol diminished the increased lipid droplets in size and number in COX-2 KO primary adipocytes. Administration of PGE2 attenuated increased fat mass and fat percentage in COX-2 deficient mice. Taken together, our study demonstrated the suppressing effect of adipocyte COX-2 on adipogenesis and reveals that COX-2 restrains adipose tissue expansion via the PGE2-mediated paracrine mechanism and prevents the development of obesity and related metabolic disorders.
    Type of Medium: Online Resource
    ISSN: 2073-4409
    URL: Article
    DOI: 10.3390/cells11111819
    Language: English
    Publisher: MDPI AG
    Publication Date: 2022
    detail.hit.zdb_id: 2661518-6
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    Online Resource
  • 10
    Online Resource
    Online Resource
    RF Signal-Based UAV Detection and Mode Classification: A Joint Feature Engineering Generator and Multi-Channel Deep Neural Network Approach
    MDPI AG ; 2021
    In:  Entropy Vol. 23, No. 12 ( 2021-12-14), p. 1678-
    Details
    In: Entropy, MDPI AG, Vol. 23, No. 12 ( 2021-12-14), p. 1678-
    Abstract: With the proliferation of Unmanned Aerial Vehicles (UAVs) to provide diverse critical services, such as surveillance, disaster management, and medicine delivery, the accurate detection of these small devices and the efficient classification of their flight modes are of paramount importance to guarantee their safe operation in our sky. Among the existing approaches, Radio Frequency (RF) based methods are less affected by complex environmental factors. The similarities between UAV RF signals and the diversity of frequency components make accurate detection and classification a particularly difficult task. To bridge this gap, we propose a joint Feature Engineering Generator (FEG) and Multi-Channel Deep Neural Network (MC-DNN) approach. Specifically, in FEG, data truncation and normalization separate different frequency components, the moving average filter reduces the outliers in the RF signal, and the concatenation fully exploits the details of the dataset. In addition, the multi-channel input in MC-DNN separates multiple frequency components and reduces the interference between them. A novel dataset that contains ten categories of RF signals from three types of UAVs is used to verify the effectiveness. Experiments show that the proposed method outperforms the state-of-the-art UAV detection and classification approaches in terms of 98.4% and F1 score of 98.3%.
    Type of Medium: Online Resource
    ISSN: 1099-4300
    URL: Article
    DOI: 10.3390/e23121678
    Language: English
    Publisher: MDPI AG
    Publication Date: 2021
    detail.hit.zdb_id: 2014734-X
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    Online Resource
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...