Biomedical subjects

Xiaohua Liu

Publications and source records attributed to Xiaohua Liu.

14 recordsLinked to original sources

PubMed2026

Efficacy and Safety of Mechanical Insufflation-Exsufflation in Invasively Ventilated Critically Ill Adults: A Systematic Review and Meta-Analysis of Randomized Controlled Trials.

BACKGROUND: Mechanical insufflation-exsufflation (MI-E) is increasingly used in invasively ventilated adults in the intensive care unit (ICU), yet its therapeutic efficacy and safety remain uncertain due to inconsistent evidence. AIM: To synthesize evidence on the clinical efficacy and safety of MI-E in this population and to examine methodological and clinical heterogeneity underlying reported outcomes. STUDY DESIGN: A systematic review and meta-analysis of randomized studies (including RCTs and randomized crossover trials), conducted following PRISMA guidelines, with risk of bias assessed using the Cochrane risk-of-bias tool. RESULTS: Five randomized controlled trials involving 310 patients were included. Meta-analysis showed that mechanical insufflation-exsufflation (MI-E) significantly increased sputum clearance (SMD = 0.63, 95% CI, 0.32-0.93; p < 0.00011; I2 = 38%) without affecting oxygenation (MD = 0.28, 95% CI, -0.53 to 1.09; p = 0.50; I2 = 9%). Data on respiratory mechanics, ventilation duration and ICU stay could not be pooled. No serious adverse events were reported. CONCLUSIONS: MI-E significantly improves sputum clearance in invasively ventilated critically ill adults, with no severe adverse events reported in the included studies. Its effects on other outcomes remain inconclusive due to limited data and heterogeneity. Standardized protocols and larger trials are needed. RELEVANCE TO CLINICAL PRACTICE: Clinicians may consider MI-E as an adjunct for respiratory secretion management. Application should be guided by structured patient assessment and individualized parameter adjustment. Future research should standardize interventions and target well-defined patient subgroups to inform clear practice guidelines. TRIAL REGISTRATION: The review protocol was registered in the International Prospective Register of Systematic Reviews, with registration number CRD42023403299.

Humans↗

PubMed2025

SMART-RNA-Metavirome: a practical RNA metavirome platform compatible with high-throughput sequencing of both short and long reads.

BACKGROUND: The RNA virosphere's extensive diversity and its role in emerging infectious diseases underscore the importance of non-targeted sequencing for identifying unknown or rare pathogens, including co-infections. However, enriching low-abundance viral sequences in RNA metaviromics, particularly in the preparation of cDNA libraries and their compatibility with next-generation sequencing (NGS) and third-generation sequencing (TGS), remains challenging. Therefore, our objective is to develop and systematically assess a practical RNA metavirome methodology specifically tailored for the enrichment of low-abundance viral sequences within samples. METHODS: We developed the SMART-RNA-Metavirome platform, integrating SMART-9n library preparation with NGS and TGS technologies. Total RNA was extracted from two field-collected wild Aedes albopictus pools, along with one laboratory-infected Ae. albopictus pool harboring dengue virus (DENV). This RNA was subjected to reverse transcription using both this optimized protocol and random primer-based methods, followed by high-throughput sequencing on Illumina, Oxford Nanopore, and QitanTech Nanopore technologies. Welch's t-test was employed for comparative analysis of the subsequent RNA metavirome data, specifically to evaluate differences in viral species composition and abundance of viral reads between experimental groups. Furthermore, the effectiveness of this platform was systematically validated via RT-qPCR and SMART-RNA-Metavirome-based Oxford Nanopore sequencing across multiple sample types, including mosquito specimens from DENV-infected Ae. albopictus, serum samples from dengue patients and viral isolates of Japanese encephalitis virus (JEV) and Zika virus (ZIKV). RESULTS: The SMART-RNA-Metavirome platform has been systematically validated to excel in enriching the composition and diversity of the RNA virome (P = 0.04), providing sufficient coverage for the complete reconstruction of viral genomes. When employed in the detection of DENV-infected Ae. albopictus, clinical serum samples, and viral isolates of JEV and ZIKV, this technique exhibits a robust correlation with RT-qPCR (r2 > 0.95). Notably, it demonstrates exceptional sensitivity, ensuring sufficient coverage even in samples of DENV-infected Ae. albopictus with a Ct-value of 35.3, attaining an impressive 99.88% genome coverage. Furthermore, this platform possesses the capability to identify virus species and determine their serotypes. CONCLUSIONS: In our study, the SMART-RNA-Metavirome platform outperforms traditional methods, enriching RNA virome composition and diversity, enabling practical compatibility with both NGS and TGS technologies. It demonstrates significant proficiency in detecting both known and unknown arboviruses, even in low-titer samples such as those from wild mosquitoes and clinical sera. This platform facilitates comprehensive monitoring, risk assessment, and early warning of RNA virus transmissions, enhancing our understanding of RNA virome diversity and ecological patterns.

High-Throughput Nucleotide Sequencing↗

PubMed2006

Porogen-induced surface modification of nano-fibrous poly(L-lactic acid) scaffolds for tissue engineering.

In addition to suitable pore architecture of a tissue-engineering scaffold, surface modification after scaffolding fabrication is often needed to enhance the interactions between cells and the synthetic material. In this study, a novel one-step process was developed to fabricate surface-modified nano-fibrous poly(L-lactic acid) (NF-PLLA) scaffolds. First, gelatin spheres with smooth surface were prepared by non-surfactant emulsification, solvent extraction, and freeze-drying. A three-dimensional NF-PLLA scaffold was then fabricated by using gelatin spheres as porogen. Gelatin molecules were entrapped onto the scaffold surface during the fabrication process. Attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR) spectroscopy and X-ray photoelectron spectroscopy analysis demonstrated the existence of gelatin molecules on the surface of the polymer scaffold. The amount of gelatin on the scaffold surface was controlled by the composition of the solvent mixture of gelatin solution. The compressive modulus of scaffold prepared with gelatin spheres was more than three times higher than that prepared with irregular gelatin particles of the same size range. The surface modification significantly improved initial cell adhesion and proliferation over a 2-week culture. SEM images indicated that cells spread on the gelatin-entrapped scaffolds in contrast to spherical or spindle morphology on the control 1 day after cell seeding. Furthermore, more matrix secretion was observed on the surface-modified scaffolds than on the control after 2 weeks of in vitro cultivation. In conclusion, this approach provides a simple one-step process to fabricate surface-modified collagen-like NF-PLLA scaffolds, which have improved cell adhesion and proliferation.

3T3 Cells↗

PubMed2006

Conformational changes of beta-lactoglobulin induced by anionic phospholipid.

Conformational changes of beta-lactoglobulin (beta-LG) induced by anionic phospholipid (dimyristoylphosphatidylglycerol, DMPG) at physiological conditions (pH 7.0) have been investigated by UV-VIS, circular dichroism (CD) and fluorescence spectra. The experimental results suggest that beta-LG-DMPG interactions cause beta-LG a structural reorganization of the secondary structure elements accompanied by an increase in alpha-helical content, and a loosening of the protein tertiary structure. The interaction forces between beta-LG and DMPG are further evaluated by fluorescence spectra. The fluorescence spectral data show that conformational changes in the protein are driven by electrostatic interaction at first, then by hydrophobic interaction between a protein with a negative net charge and a negatively charged phospholipid.

Anions↗

PubMed2006

Size effect on the crystal structure of silver nanowires.

A 4H structural silver nanowire (4H-AgNW) is discovered to coexist with a face-centered cubic (FCC) one prepared by electrochemical deposition and to have the highest concentration in the total of 4H- and FCC-AgNWs with diameters around 30 nm. Moreover, the concentration becomes smaller when the diameters deviate from 30 nm. This size effect arises from the fact that 4H-AgNW has a more favorable surface configuration but higher volume internal energy than FCC-AgNW, which is proved by our model.

Journal Article↗

PubMed2005

Separation of conjugated linoleic acid isomers by cyclodextrin-modified micellar electrokinetic chromatography.

A cyclodextrin-modified micellar electrokinetic chromatography (CD-MEKC) method was developed for separating conjugated linoleic acid (CLA) isomers. All the seven CLA isomers (9cis,11cis-CLA, 9cis,11trans-CLA, 9trans,11trans-CLA, 10trans,12cis-CLA, 11cis,13cis-CLA, 11cis,13trans-CLA and 11trans,13trans-CLA) were completely separated in the optimized conditions (4% (w/v) beta-cyclodextrin (beta-CD), 54 mM sodium dodecyl sulphate (SDS), 80 mM borate (pH 9.0), 8 M urea, 4% (v/v) ethanol, 30 kV and 15 degrees C). The CD-MEKC method was superior to the gas chromatographic (GC) and silver-ion high-performance liquid chromatographic (Ag(+)-HPLC) methods that were generally used in analyzing CLA isomers.

Chromatography, Micellar Electrokinetic Capillary↗

PubMed2005

The abnormal apoptosis of T cell subsets and possible involvement of IL-10 in systemic lupus erythematosus.

To study the apoptosis of lymphocyte subpopulations in systemic lupus erythematosus (SLE) patients and the possible role of IL-10 in this apoptosis involved in the pathogenesis of SLE, three color fluorescence and flow cytometry were used to investigate the early apoptosis of lymphocyte subsets from freshly separated or cultured peripheral blood mononuclear cells (PBMCs). ELISA was employed to detect the levels of IL-10 in serum and the levels of sFas and sFasL in cultured PBMC supernatants, and the results of sFas and sFasL were confirmed by real-time PCR of Fas and FasL mRNA. The results showed that in cells from SLE patients, the apoptosis of CD3+, CD4+, and CD8+ T cells was distinctly increased, and the percentage of CD4+ cells and the CD4/CD8 ratio was significantly decreased, as compared with normal controls. The apoptosis of T lymphocytes cultured with SLE serum was markedly higher than that of cells cultured with control's serum. Blockade of interleukin-10 (IL-10) activation by an anti-IL-10 antibody reduced the SLE serum induced apoptosis of CD4+ and CD8+ T cells. The levels of sFas and sFasL in the culture supernatant and Fas and FasL mRNA expressions in cultured cells were significantly higher in the SLE serum-cultured groups, but decreased evidently in the presence of the anti-IL-10 antibody. Above findings suggested that SLE cells showed abnormally high apoptosis of T lymphocytes, especially of the CD4+ subpopulation, resulting in a decreased CD4/CD8 ratio. The high percentage of apoptotic T cells in SLE patients may be related to the high levels of IL-10 in SLE serum, as IL-10 may induce the abnormally activated T cells to trigger apoptosis via the Fas-FasL pathway.

Adult↗

PubMed2005

Catalytic asymmetric cyanosilylation of ketones by a chiral amino acid salt.

In this Communication, we describe the first highly enantioselective cyanosilylation of ketones catalyzed by simple chiral amino acid salt. A broad range of aromatic, alpha,beta-unsaturated, heterocyclic ketones catalyzed by l-phenylglycine sodium salt gave the corresponding trimethylsilyl ethers of cyanohydrins in 75-96% yields with 86-97% enantioselectivities. A catalytic cycle based on experimental phenomena and studies has been proposed to explain the origin of this activation. The reaction employed commercially available and fully recyclable catalysts and involves a simple experimental procedure.

Journal Article↗

PubMed2005

Surface modification of interconnected porous scaffolds.

Surface properties of scaffolds play an important role in cell adhesion and growth. Biodegradable poly(alpha-hydroxy acids) have been widely used as scaffolding materials for tissue engineering; however, the lack of functional groups is a limitation. In this work, gelatin was successfully immobilized onto the surface of poly(alpha-hydroxy acids) films and porous scaffolds by a new entrapment process. The surface composition and properties were examined using attenuated total reflection-Fourier transform infrared spectroscopy (ATR-FTIR), X-ray photoelectron spectra (XPS), and contact angle measurements. Control over the amount of entrapped gelatin was achieved by varying the solvent composition, the duration of soaking, the concentration of gelatin in solution, and chemical crosslinking. The amount of entrapped gelatin increased with the ratio of dioxane/water in the solvent mixture used. Chemical crosslinking after physical entrapment considerably increased the amount of retained gelatin on the surface of poly(alpha-hydroxy acids). Osteoblasts were cultured on these films and scaffolds. The surface modification significantly improved cell attachment and proliferation. Cell numbers on the surface-modified films and scaffolds were significantly higher than those on controls 4 h and 1 day after cell seeding. The osteoblasts showed higher proliferation on surface-modified scaffolds than on the control during 4 weeks of in vitro cultivation. More collagen fibers and other cell secretions were deposited on the surface-modified scaffolds than on the control scaffolds. This novel surface treatment strategy provides a convenient and universal way to modify the surface properties of three-dimensional scaffolds and thus promote cell adhesion and proliferation for tissue engineering.

Biocompatible Materials↗

PubMed2005

Liquid phase coating to produce controlled-release alginate microspheres.

This study explored a liquid phase coating technique to produce polymethyl methacrylate (PMMA)-coated alginate microspheres. Alginate microspheres with a mean diameter of 85.6 microm were prepared using an emulsification method. The alginate microspheres, as cores, were then coated with different types of PMMA by a liquid phase coating technique. The release characteristics of these coated microspheres in simulated gastric (SGF) and intestinal (SIF) fluids and the influence of drug load on encapsulation efficiency were studied. The release of paracetamol, as a model hydrophilic drug, from the coated microspheres in SGF and SIF was greatly retarded. Release rates of Eudragit RS100-coated microspheres in SGF and SIF were similar as the rate-controlling polymer coat was insoluble in both media. Drug release from Eudragit S100-coated microspheres was more sustained in SGF than in SIF, due to the greater solubility of the coating polymer in media with pH greater than 7.0. The drug release rate was affected by the core:coat ratio. Drug release from the coated microspheres was best described by the Higuchi's square root model. The liquid phase coating technique developed offers an efficient method of coating small microspheres with markedly reduced drug loss and possible controlled drug release.

Acetaminophen↗

PubMed2004

Enantioselective cyanosilylation of ketones by a catalytic double-activation method with an aluminium complex and an N-oxide.

Double-activation catalysis promises high catalytic efficiency in the enantioselective cyanosilylation of ketones through the combined use of a Lewis acid and a Lewis base. Catalyst systems composed of a chiral salen-Al complex and an N-oxide have high catalytic turnovers (200 for aromatic ketones, 1000 for aliphatic ones). With these catalysts, a wide range of aliphatic and aromatic ketones were converted under mild conditions into tertiary cyanohydrin O-TMS ethers in excellent yields and with high enantioselectivities (94% ee for aromatic ketones, 90% ee for aliphatic ones). Preliminary mechanistic studies revealed that the salen-Al complex played the role of a Lewis acid to activate the ketone and the N-oxide that of a Lewis base to activate TMSCN; that is, double activation.

Journal Article↗

PubMed2004

Polymeric scaffolds for bone tissue engineering.

Bone tissue engineering is a rapidly developing area. Engineering bone typically uses an artificial extracellular matrix (scaffold), osteoblasts or cells that can become osteoblasts, and regulating factors that promote cell attachment, differentiation, and mineralized bone formation. Among them, highly porous scaffolds play a critical role in cell seeding, proliferation, and new 3D-tissue formation. A variety of biodegradable polymer materials and scaffolding fabrication techniques for bone tissue engineering have been investigated over the past decade. This article reviews the polymer materials, scaffold design, and fabrication methods for bone tissue engineering. Advantages and limitations of these materials and methods are analyzed. Various architectural parameters of scaffolds important for bone tissue engineering (e.g. porosity, pore size, interconnectivity, and pore-wall microstructures) are discussed. Surface modification of scaffolds is also discussed based on the significant effect of surface chemistry on cells adhesion and function.

Animals↗

PubMedDate not supplied

Flow injection chemiluminescent determination of tetracycline using a tris(2,2'-bipyridine)ruthenium(II)-cerium(IV) sulphate system.

A flow-injection chemiluminescence method for the determination of tetracycline was developed. The method is based on an enhancement by tetracycline of the chemiluminescence light emission of tris(2,2'-bipyridine)ruthenium(II). In sulphuric acid medium, the chemiluminescence is generated by the continuous oxidation of tris(2,2'-bipyridine)ruthenium(II) by cerium (IV) sulphate. The light-emission intensity is greatly enhanced in the presence of tetracycline. Under the optimum conditions, the calibration curve is linear over the range 3.75 x 10(-8) g/mL-1.5 x 10(-5) g/mL for tetracycline with the linear equation: deltaINT = 205.898 x C - 20.442 (R2 = 0.9974). The detection limit is 3.27 x 10(-8) g/mL. The proposed method was also successfully used to determine tetracycline in pharmaceutical formulation (mean recovery of tetracycline, 100.7%).

2,2'-Dipyridyl↗

PubMedDate not supplied

Determination of oxytetracycline by flow injection with chemiluminescence detection.

A flow-injection chemiluminescent method for the determination of oxytetracycline was developed. The method is based on an enhancement by oxytetracycline of the chemiluminescence light emission of tris(2,2'-bipyridine) ruthenium (II), generated by the continuous oxidation of tris(2,2'-bipyridine) ruthenium (II) by cerium (IV) sulphate in sulphuric acid. Under the optimum conditions, the calibration curve was linear over the range 1.0 x 10(-7)-1.0 x 10(-5) g/mL for oxytetracycline with the linear equation: DeltaINT = 148.77 x C + 0.6637 (R2 = 0.9994). The detection limit was 4.52 x 10(-8) g/mL. The proposed method was also successfully used to determine oxytetracycline in pharmaceutical formulations. The mean recovery of determination of oxytetracycline was 92.73%. A mechanism for the chemiluminescence enhancement by oxytetracycline of tris(2,2'-bipyridine)-ruthenium (II) and cerium (IV) sulphate system is also proposed.

2,2'-Dipyridyl↗