Publications by authors named "Wenquan Zhu"

Article Synopsis
  • * The process involved extracting and purifying the estrogens, followed by spotting them on a chromatography plate for separation and UV visual detection.
  • * The method demonstrated high specificity, stability, and sensitivity, with detection limits for each estrogen varying between 0.497 and 1.00 mg/mL, and could enhance identification standards for estrogen preparations.
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Alpine grasslands on the Qinghai-Tibet Plateau (QTP) play an essential role in water conservation, biodiversity protection and climate feedback, with aboveground biomass (AGB) serving as a crucial indicator of grassland health and functionality. While previous studies have independently explored the phenological differences, cumulative effects, and spatial variability of climatic impacts on biomass/productivity in alpine grasslands, the cascading effects regarding climate and phenology on AGB still present knowledge gaps. Here, using peak AGB measurements, remote sensing and gridded climate data in the QTP alpine grasslands during 2002-2018, we systematically analyzed the impact paths of climatic variables (i.

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The mechanism underlying the effects of livestock grazing on grassland ecosystem traits has been greatly discussed. However, as a common small burrowing mammal on the Tibetan Plateau grasslands, the plateau pika's (Ochotona curzoniae) influence on alpine grassland ecosystem traits has rarely been investigated, especially beyond the plot scale. In this study, we flew an unmanned aerial vehicle (UAV) over a grassland landscape under grazing and nongrazing treatments.

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Hecogenin (HCG), a steroidal sapogenin, possesses good antitumor properties. However, the application of HCG for cancer treatment has been hindered primarily by its moderate potency. In this study, we incorporated triphenylphosphonium cation (TPP) at the C-3 and C-12 positions through different lengths of alkyl chains to target mitochondria and enhance the efficacy and selectivity of the parent compound.

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Article Synopsis
  • Anti-tumor drugs often face challenges like side effects and ineffective delivery to tumors, reducing chemotherapy's effectiveness.
  • Researchers developed an innovative drug delivery system (MCN-SS-GQDs) using mesoporous carbon nanoparticles for better drug loading and graphene quantum dots for controlled release based on the tumor environment.
  • This system utilizes photothermal properties to increase local temperatures in tumors, promoting drug release and sensitivity of tumor cells to chemotherapy, while also ensuring deeper penetration into tumor tissues.
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The water solubility and side effects of lamivudine limit its application for the treatment of viral hepatitis type B and human immunodeficiency virus. In order to increase the solubility of LA and improve the in vivo membrane permeability of the drug, LA was modified with hexadecane acid to prepare the prodrug lamivudine palmitic acid (LAP) and loaded into nanoemulsome (NES). LAP-NES was prepared by the thin film dispersion method.

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The implications of climate change for rice yield have significant repercussions for food security, particularly in China, where rice cultivation is diverse, involving various cropping intensities, management practices, and climate conditions across numerous regions. The regional discrepancies in the impact of climate change on rice yield in China, however, are yet to be fully understood. Using the ORYZA(v3) model and future climate data from 2025 to 2084, gathered from ten climate models and three climate change scenarios (RCP2.

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Immunotherapy is a promising cancer treatment strategy. In contrast, programmed cell death 1 (PD-1)/programmed cell death ligand 1 (PD-L1) inhibitors are associated with low response rates and are only useful in a small group of cancer patients. A combination of treatments may be effective for overcoming this clinical issue.

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To improve the anti-metastasis effects of honokiol (HNK) on breast cancer, we designed cationic liposomes (Lip) in which HNK was encapsulated into Lip, and its surface was modified with negatively charged polysialic acid (PSA-Lip-HNK) for efficient treatment of breast cancer. PSA-Lip-HNK possessed a homogeneous spherical shape and high encapsulation efficiency. 4T1 cell experiments indicated that PSA-Lip-HNK increased cellular uptake and cytotoxicity via the endocytosis pathway mediated by PSA and selectin receptors.

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Recently, the therapeutic effect of chemotherapy has been obviously impaired due to premature drug release, low tumor penetration, and multidrug resistance of nanoplatforms. In this paper, a novel multiple-sensitive drug delivery system (MC-ss-CDs) was developed by gating long-wavelength emitting carbon dots (CDs) on the openings of mesoporous carbon nanoparticles (MC) through disulfide bonds. The MC with excellent photothermal transition efficiency and high drug storage capacity for doxorubicin (DOX) was used as the delivery carrier.

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Chronic lead poisoning has become a major factor in global public health. Chelation therapy is usually used to manage lead poisoning. Dimercaptosuccinic acid (DMSA) is a widely used heavy metal chelation agent.

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Lurasidone is an antipsychotic drug clinically used for the treatment of schizophrenia and bipolar disorder. During a mechanism-based forced degradation study of lurasidone, two novel degradation products were observed under free radical-mediated oxidative (via AIBN) and solution photolytic conditions. The structures of the two novel degradants were identified through an approach combining HPLC, LC-MS (n = 1, 2), preparative HPLC purification and NMR spectroscopy.

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Different species within the same community may exhibit distinct phenological responses to climate change, so it is necessary to study species differences in the green-up date among abundant species within a wide area, and a suitable phenology model should be introduced to explain the associated climate-driven mechanism. Although various models have been developed, very few studies have aimed to compare their efficiency and robustness, and the relative contributions of climate driving factors have not been sufficiently examined. We analyzed phenology data for 12 species across 17 stations in Inner Mongolia and found that essential spatiotemporal and interspecies differences existed in the green-up date.

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During the related substances testing method development for linagliptin tablet, an unknown peak was observed in HPLC chromatograms with a level exceeding the identification threshold. By using a strategy that combines LC-PDA/UV-MS with mechanism-based stress studies, the unknown peak was rapidly identified as linagliptin urea, a solution degradant that is caused by the reaction between the API and hydrocyanic acid with sonication treatment to accelerate dissolution of the drug substance in sample preparation of linagliptin tablets, and hydrocyanic acid is a known impurity in HPLC grade acetonitrile and acetonitrile is used as part of diluent. The mechanism of the solution degradation chemistry was verified by stressing linagliptin API with trimethylsilyl cyanide (TMSCN, which can give off HCN slowly in the presence of water) treated with sonication in the sample preparation.

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Rationale: The focus of this work was to study glycosylamine and Amadori rearrangement products (ARPs), the two major degradants in the Maillard reactions of pharmaceutical interest, and utilize their MS fingerprints by liquid chromatography/high-resolution tandem mass spectrometry (LC/HRMS ) to quickly distinguish the two isomeric degradants. These two types of degradants are frequently encountered in the compatibility and stability studies of drug products containing primary or secondary amine active pharmaceutical ingredients (APIs), which are formulated with excipients consisting of reducing sugar functionalities.

Methods: Vortioxetine was employed as the primary model compound to react with lactose to obtain the glycosylamine and ARP degradants of the Maillard reaction, and their MS spectra (MS fingerprints) were obtained by LC/MS .

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A spherical iron oxide precursor was prepared using a solvothermal method, and then treated thermally at 400°C to obtain α-FeO nanoparticles. The structures and morphology of the as-obtained products were characterized using X-ray diffraction (XRD), transmission electron microscopy (TEM), and scanning electron microscopy (SEM). The results showed that the diameter of the α-FeO nanoparticles was approximately 500 nm.

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Nanostructured lipid carriers (NLC) have become a research hotspot, wherein cancer-targeting effects are enhanced and side effects of chemotherapy are overcome. Usually, accelerated blood clearance (ABC) occurs after repeated injections, without changing the immunologic profile, despite PEGylation which prolongs the circulation function. To overcome these problems, we designed a red blood cell-membrane-coated NLC (RBCm-NLC), which was round-like, with a particle size of 60.

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Purpose: The goal of the study was to elucidate the structure of a new degradant (1,3'-Dimer), generated in the stability testing of ropinirole extended-release tablets, and the formation mechanism of 1,3'-Dimer and its isomer (3,3'-Dimer).

Methods: The strategy of combining LC-PDA/UV-MS (n = 1, 2) and NMR in conjunction with mechanism-based forced degradation study was employed to identify the structure of the unknown degradant and the formation mechanism of this dimeric degradant as well as its isomer, 3,3'-Dimer. The forced degradation was conducted by treating ropinirole API with formaldehyde under alkaline catalysis.

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During our method development for residual formaldehyde detection in a drug substance, unusually high levels of formaldehyde were detected when using a mixed solvent of EtOH/DMSO (4:1, v/v) as sample diluent in headspace GC analysis (HS-GC). Initial investigation found that formaldehyde is used in the preparation for one of the starting materials of the drug substance. Nevertheless, there is neither other source of formaldehyde in the manufacturing process of the drug substance, nor would formaldehyde be generated during the process.

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An enzyme-responsive colon-specific delivery system was developed based on hollow mesoporous silica spheres (HMSS) to which biodegradable chitosan (CS) was attached via cleavable azo bonds (HMSS-N=N-CS). Doxorubicin (DOX) was encapsulated in a noncrystalline state in the hollow cavity and mesopores of HMSS with the high loading amount of 35.2%.

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Based on the antisolvent and electrostatic deposition methods, we fabricated zein/hyaluronic acid core-shell nanoparticles loaded with honokiol (HA-Zein-HNK), which could target delivery and enhance the therapeutic effect of the HNK. The prepared nanoparticles were found to have a mean size of 210.4 nm and negative surface charge.

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In an effort to enhance antitumor and anti-metastasis of breast cancer, honokiol (HNK) was encapsulated into hyaluronic acid (HA) modified cationic liposomes (Lip). The prepared HA-Lip-HNK had a spherical shape with a narrow size distribution. The enhanced antitumor efficacy of HA-Lip-HNK was investigated in 4T1 cells in vitro, wherein flow cytometry and confocal microscopy analysis revealed its HA/CD44-mediated greater cellular internalization.

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During the pharmaceutical development of pregabalin extended-release tablets, an unknown degradant at a relative retention time (RRT) of 11.7 was observed and its nominal amount exceeded the ICH identification threshold in an accelerated stability study. The aim of this study is to identify the structure and investigate the formation mechanism of this impurity for the purpose of developing a chemically stable pharmaceutical product.

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To effectively inhibit the growth of breast cancer cells (MDA-MB-231 cells) by the combination method of chemotherapy and magnetic hyperthermia, we fabricated a biomimetic drug delivery (CSiFePNs) system composed of mesoporous silica nanoparticles (MSNs) containing superparamagnetic ferroferric oxide and Paclitaxel (PTX) coated with MDA-MB-231 cell membranes (CMs). In the in vitro cytotoxicity tests, the MDA-MB-231 cells incubated with CSiFePNs obtained IC value of 0.8 μgL, 3.

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