Publications by authors named "Dou Liu"

We present a near real-time measurement method that combines Raman and spark emission spectroscopy to quantitatively analyze the molecular structure of airborne single-walled carbon nanotubes (SWCNTs) and multi-walled carbon nanotubes (MWCNTs), as well as detect toxic metals within CNTs. A corona-based aerosol microconcentrator was used for airborne CNTs sampling to enhance the measurement accuracy and sensitivity. The intensity of the characteristic Raman bands of CNTs and atomic emission lines of metals exhibited a linear relationship with the analyte mass, yielding high coefficient values.

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Low-cost sensor networks offer the potential to reduce monitoring costs while providing high-resolution spatiotemporal data on pollutant levels. However, these sensors come with limitations, and many aspects of their field performance remain underexplored. During October to December 2023, this study deployed two identical low-cost sensor systems near an urban standard monitoring station to record PM2.

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P-glycoprotein (P-gp), breast cancer resistance protein (BCRP), and multidrug resistance-associated protein 2 (MRP2) are clinically relevant efflux transporters implicated in the oral absorption of many food and drug substrates. Here, we hypothesised that food intake could influence protein and mRNA intestinal expression of P-gp/abcb1a, BCRP/abcg2, and MRP2/abcc2 differently in male and female Wistar and Sprague Dawley rats. To test this hypothesis, we used enzyme-linked immunosorbent assay (ELISA) and real-time polymerase chain reaction (PCR) to quantify the protein and mRNA intestinal expression of these transporters, respectively.

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Many subsidence lakes have formed in eastern China as a result of underground coal mining. These coal mining-related subsidence lakes vary in their formation time and connectivity with rivers. These factors may influence the water chemistry and hydrogen and oxygen stable isotope characteristics of the lake water.

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Article Synopsis
  • * This study explored ileocolonic-targeted delivery of tofacitinib, finding it leads to higher tissue exposure and lower systemic exposure compared to standard delivery methods.
  • * Targeted tofacitinib reduced inflammatory markers in a rat model of colonic inflammation more effectively than other formulations, indicating promise for future IBD treatments.
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First-line treatments for mild to moderate psoriasis are typically topical formulations containing corticosteroids, however, the therapeutic efficacy of these formulations is compromised by limited penetration and skin retention. Even more challenging, off-target corticosteroids are known to adversely affect healthy skin, including induction of epidermal and dermal atrophy. Here, we report a nanoparticle-based topical formulation that cures psoriasis in a single dose, but leaves healthy skin intact.

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The effective treatment of esophageal disease represents a significant unmet clinical need, as existing treatments often lead to unnecessary systemic drug exposure and suboptimal concentrations at the disease site. Here, surface-modified bioadhesive poly(lactic acid)-hyperbranched polyglycerol nanoparticles (BNPs), with an average 100-200 nm diameter, were developed for local and sustained esophageal drug delivery. BNPs showed significantly higher adhesion and permeation into human and rat esophageal tissue than non-adhesive nanoparticles (NNPs) and had longer residence times within the rat esophagus .

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Wistar and Sprague Dawley are the most common strains of rat used in pharmaceutical research and are used interchangeably in pre-clinical drug development. No studies have assessed whether Wistar and Sprague Dawley rats are equivalent in the gastrointestinal factors that influence oral drug absorption, specifically in relation to intestinal transporters. Enzyme-linked immunosorbent assay (ELISA) and liquid chromatography-tandem mass spectrometry (LC-MS/MS) are two reliable methods for quantifying intestinal protein levels with their own distinct advantages and limitations.

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Intestinal interactions with nutrients, xenobiotics and endogenous hormones can influence the expression of clinically relevant membrane transporters. These changes in the gastrointestinal (GI) physiology can in turn affect the absorption of numerous drug substrates. Several studies have examined the effect of food on intestinal transporters in male and female humans and animal models.

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: Physiological pH and chemical pKa are two sides of the same coin in defining the ionization of a drug in the human body. The Henderson-Hasselbalch equation and pH-partition hypothesis form the theoretical base to define the impact of pH-pKa crosstalk on drug ionization and thence its absorption, distribution, metabolism, excretion, and toxicity (ADMET).: Human physiological pH is not constant, but a diverse, dynamic state regulated by various biological mechanisms, while the chemical pKa is generally a constant defining the acidic dissociation of the drug at various environmental pH.

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Intestinal efflux transporters affect the gastrointestinal processing of many drugs but further data on their intestinal expression levels are required. Relative mRNA expression and relative and absolute protein expression data of transporters are commonly measured by real-time polymerase chain reaction (RT-PCR), Western blot and mass spectrometry-based targeted proteomics techniques. All of these methods, however, have their own strengths and limitations, and therefore, validation for optimized quantification methods is needed.

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Intestinal stromal cells are known to modulate the propagation and differentiation of intestinal stem cells. However, the precise cellular and molecular mechanisms by which this diverse stromal cell population maintains tissue homeostasis and repair are poorly understood. Here we describe a subset of intestinal stromal cells, named MAP3K2-regulated intestinal stromal cells (MRISCs), and show that they are the primary cellular source of the WNT agonist R-spondin 1 following intestinal injury in mice.

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Nowadays, the biomolecular assay platforms built-up based on bead counting technologies have emerged to be powerful tools for the sensitive and high-throughput detection of disease biomarkers. In this mini-review, we classified the bead counting technologies into statistical counting platforms and digital counting platforms. The design principles, the readout strategies, as well as the pros and cons of these platforms are introduced in detail.

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Active pharmaceutical ingredients are routinely formulated with a range of excipients in the manufacture of drug products. Excipients are considered to be inert components of the formulations, although recent research has contested its inactive behaviour. This study investigated the effect of the excipient polyethylene glycol 400 (PEG 400) on the oral bioavailability and intestinal permeability of cimetidine in male and female human volunteers.

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The rat is one of the most commonly used animal models in pre-clinical studies. Limited information between the sexes and the effect of food consumption on the gastrointestinal (GI) physiology, however, is acknowledged or understood. This study aimed to investigate the potential sex differences and effect of food intake on the intestinal luminal fluid and the efflux membrane transporter P-glycoprotein (P-gp) along the intestinal tract of male and female Wistar rats.

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Objective: To investigate the prognostic value of metabolic tumor volume (MTV) and total lesion glycolysis (TLG), measured by preoperative ¹⁸F-fluorodeoxyglucose positron emission tomography/computed tomography (¹⁸F-FDG PET/CT), in risk stratification of patients with endometrial carcinoma (EC).

Methods: The patients with pathological diagnosis of EC who underwent preoperative ¹⁸F-FDG PET/CT imaging were retrospectively selected for analysis of the prognostic values of PET parameters in risk classification and lymph node metastases (LNMs). Receiver-operating-characteristic analysis was used to analyze the correlation of PET parameters cutoff values with deep myometrial invasion (MI), lymphovascular space involvement and LNM for prognostic values in risk stratification.

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In this work, we report new formulations for the combined photo-chemotherapy of colon cancer. Fibers were fabricated via coaxial-electrospinning with the intent of targeting delivery of the anti-cancer drug carmofur (CAR) and the photosensitizer rose bengal (RB) selectively to the colon site. The fibers comprised a hydroxypropyl methylcellulose (HPMC) core loaded with the active ingredients, and a pH-sensitive Eudragit L100-55 shell.

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It is known that males and females respond differently to medicines and that differences in drug behaviour are due to inter-individual variability and sex specificity. In this work, we have examined the influence of pharmaceutical excipients on drug bioavailability in males and females. Using a rat model, we report that a portfolio of polyoxyethylated solubilising excipients (polyethylene glycol 2000, Cremophor RH 40, Poloxamer 188 and Tween 80) increase ranitidine bioavailability in males but not in females.

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In the version of this Article originally published, the labels for Rictor and mTOR in the whole cell lysate (WCL) blots were swapped in Fig. 3b and the mTOR blot was placed upside down. Unprocessed blots of mTOR were also missing from Supplementary Fig.

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Proper control of B cell growth and metabolism is crucial for B-cell-mediated immunity, but the underlying molecular mechanisms remain incompletely understood. In this study, Sin1, a key component of mTOR complex 2 (mTORC2), specifically regulates B cell growth and metabolism. Genetic ablation of Sin1 in B cells reduces the cell size at either the transitional stage or upon antigen stimulation and severely impairs metabolism.

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The first activation of saturated acid chlorides by oxidative N-heterocyclic carbene catalysis has been successfully utilized to synthesize enantio-enriched spirooxindole lactones and δ-lactones. The reaction involves the transformation of the β sp3 carbon of saturated acid chlorides into an electrophilic carbon as a key step. The product was obtained in excellent yield and stereoselectivity.

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Glucose metabolism plays a key role in thymocyte development. The mammalian target of rapamycin complex 2 (mTORC2) is a critical regulator of cell growth and metabolism, but its role in early thymocyte development and metabolism has not been fully studied. We show here that genetic ablation of Sin1, an essential component of mTORC2, in T lineage cells results in severely impaired thymocyte development at the CD4-CD8- double negative (DN) stages but not at the CD4+CD8+ double positive (DP) or later stages.

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The aim of this study was to explore the influence of food on P-glycoprotein (P-gp) relative expression in both male and female rats, and its effect on intestinal permeation of P-gp substrates (ranitidine and ganciclovir) and a P-gp non-substrate (metformin). The intestine of 12 male and 12 female Wistar rats were excised and segmented into the duodenum, jejunum, ileum and colon. P-gp extracted from each segment was then determined via Western-blotting.

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Recirculation of naive T cells between secondary lymphoid organs to receive survival cues and scan for signs of infection or other pathologic conditions is important for immune homeostasis and effective immune responses. Although the mechanisms that specifically guide the entry of naive T cells into secondary lymphoid organs are well studied, the mechanisms that keep them from fluxing into inappropriate or undesirable compartments, such as healthy tissues or bone marrow, are less well understood. In this study, we report an unexpected finding that under steady state, bone marrow homing of naive T cells is actively suppressed by mTORC2 signaling.

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There is a growing body of evidence which suggests that formerly regarded "inert" pharmaceutical excipients have the potential to influence oral drug bioavailability. The solubilizing agent polyethylene glycol 400 (PEG 400), for instance, has a sex-specific effect on P-glycoprotein (P-gp)-mediated drug bioavailability. We hypothesized that such an effect could be via PEG-induced alteration of P-gp activity and/or expression to different extents in males and females.

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