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"Cheng, Junwen"
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A cellulose/Konjac glucomannan–based macroporous antibacterial wound dressing with synergistic and complementary effects for accelerated wound healing
2021
Maintaining an optimal moisture level and preventing infection of the tissues surrounding wounds remain critical challenges in wound healing. In this study, antibacterial and moisturizing dressings were fabricated based on cellulose/konjac glucomannan (KGM)/Ag nanoparticle composites via a simple two-step method. First, cellulose/KGM gels were prepared by combining cellulose and KGM with the aid of an ionic liquid, 1-allyl-3-methylimidazolium chloride. Subsequently, Ag nanoparticles were directly formed via in situ reduction of silver nitrate in the cellulose/KGM gel. The experimental results revealed that the swelling behavior, moisture retention, mechanical properties, and antibacterial activity of the composite gel could be readily manipulated by modulating the cellulose-to-KGM ratio and silver nitrate concentration. The CK7-Ag3 aerogel with large pore structure, desired water swelling, and mechanical and antibacterial properties was found to be a competent wound dressing for further characterization. Importantly, in vitro and in vivo studies indicated that CK7-Ag3 aerogel has excellent antibacterial activity and biocompatibility and that it can enable complete wound recovery within only 14 days by inducing cell proliferation. Given the low cost and high healing efficiency, this wound dressing can potentially be used in clinical applications.
Journal Article
Natural Deep Eutectic Solvent-Assisted Extraction, Structural Characterization, and Immunomodulatory Activity of Polysaccharides from Paecilomyces hepiali
by
Chunru Li
,
Yanbin Wang
,
Xueqian Wu
in
Biocompatibility
,
Carboxylic Acids
,
deep eutectic solvent
2022
Polysaccharides, which can be affected by different preparations, play a crucial role in the biological function of Paecilomyces hepiali (PHPS) as a health food. To explore high-valued polysaccharides and reduce the negative influence of human involvement, a green tailorable deep eutectic solvent (DES) was applied to optimize the extraction of polysaccharides (PHPS-D), followed by the evaluation of the structural properties and immunomodulation by comparison with the hot-water method (PHPS-W). The results indicated that the best system for PHPS-D was a type of carboxylic acid-based DES consisting of choline chloride and succinic acid in the molar ratio of 1:3, with a 30% water content. The optimal condition was as follows: liquid–solid ratio of 50 mL/g, extraction temperature of 85 °C, and extraction time of 1.7 h. The actual PHPS-D yield was 12.78 ± 0.17%, which was obviously higher than that of PHPS-W. The structural characteristics suggested that PHPS-D contained more uronic acid (22.34 ± 1.38%) and glucose (40.3 ± 0.5%), with a higher molecular weight (3.26 × 105 g/mol) and longer radius of gyration (78.2 ± 3.6 nm), as well as extended chain conformation, compared with PHPS-W, and these results were confirmed by AFM and SEM. Immunomodulatory assays suggested that PHPS-D showed better performance than PHPS-W regarding pinocytic activity and the secretion of NO and pro-inflammatory cytokines (IL-6, TNF-α and IL-1β) by activating the corresponding mRNA expression in RAW264.7 cells. This study showed that carboxylic acid-based DES could be a promising tailorable green system for acidic polysaccharide preparation and the valorization of P. hepiali in functional foods.
Journal Article
Heat Transfer Performance and Flow Characteristics of Helical Baffle–Corrugated Tube Heat Exchanger
2024
Heat exchangers are widely used in petrochemical and other industries. Improving the efficiency of heat exchangers to increase energy utilization is crucial. Passive enhanced heat transfer technology is widely studied in heat exchanger research due to its low energy consumption and simple operation. Helical baffle–corrugated tube heat exchangers have not been extensively studied as a promising new class of these devices. This paper investigates the key structural parameters of a helical baffle-corrugated heat exchanger through numerical simulation. This study focuses on the factors affecting heat transfer and flow resistance performance. The results show that reducing the helical angle from 28.42° to 10.81° increases the total heat transfer coefficient by approximately 20%. The overall performance of the heat exchanger is evaluated using the efficiency evaluation coefficient (EEC). Optimal levels of each structural factor are determined for different working conditions based on this evaluation.
Journal Article
Efficacy comparison between intramedullary nail fixation and plate fixation in distal tibia fractures: a meta-analysis of randomized controlled trials
2024
Background
Intramedullary nail (IMN) and plate fixation are the most commonly used surgical modalities for distal tibia fractures. However, the superiority of their efficacy regarding functional outcomes and complications remains controversial. Here, we performed a systematic review and meta-analysis to compare the efficacy of these two modalities.
Methods
Randomized controlled trials (RCTs) comparing the efficacy of IMN and plate fixation in distal tibia fractures were searched in PubMed, Web of Science, EMBASE, ClinicalTrials.gov, and Cochrane Library up to January 31, 2024. Weighted mean difference (WMD) and odds ratio (OR) with corresponding 95% confidence interval (CI) were estimated using a random-effect model for continuous and categorical outcomes, respectively.
Results
A total of 20 RCTs comprising 1528 patients were included. Compared with plate fixation, IMN significantly shortened surgery time (WMD=-10.73 min, 95%CI: -15.93 to -5.52), union time (WMD=-1.56 weeks, 95%CI: -2.82 to -0.30), and partial (WMD=-1.71 weeks, 95%CI: -1.91 to -0.43) and full (WMD=-2.61 weeks, 95%CI: -3.53 to -1.70) weight-bearing time. IMN was associated with markedly reduced risk of wound infection (OR = 0.44, 95%CI: 0.31–0.63) and secondary procedures (OR = 0.72, 95%CI: 0.55–0.95), but increased the risk of malunion (OR = 1.53, 95%CI: 1.02–2.30) and anterior knee pain (OR = 3.94, 95%CI: 1.68–9.28). The rates of nonunion, delayed union, and functional assessment scores did not significantly differ between the two groups. The percentages of patients obtaining an excellent functional outcome or an excellent and good functional outcome post-operation were comparable.
Conclusions
Both IMN and plate fixation are effective modalities for the surgical treatment of distal tibia fractures. IMN seems to be preferred since it confers more advantages, but the elevated rates of malunion and knee pain require attention. The decision on fixation modality should be tailored to the specific fracture, considering these pros and cons.
Journal Article
Optimization of the Solid-state Fermentation and Properties of a Polysaccharide from Paecilomyces cicadae (Miquel) Samson and Its Antioxidant Activities In Vitro
2014
The culture conditions for the yield of a polysaccharide (PCPS) produced by Paecilomyces cicadae (Miquel) Samson on solid-state fermentation were investigated using response surface methodology (RSM). Plackett-Burman design (PBD) was applied to screen out significant factors, followed by the paths of steepest ascent to move to the nearest region of maximum response. Then Box-Behnken design (BBD) was conducted to optimize the final levels of the culture conditions. After analyzing the regression equation and the response surface contour plots, relative humidity 56.07%, inoculum 13.51 mL/100 g and temperature 27.09°C were found to be the optimal key parameters for PCPS production. The maximum predicted yield of PCPS was 10.76 mg/g under the optimized conditions. The resulting PCPS (FPCPS) generated at optimal conditions was purified by chromatography column and found to be composed of mannose (43.2%), rhamnose (32.1%), xylose (14.5%) and arabinose (10.2%). Based on the size exclusion chromatography combined with multi-angle laser light scattering (SEC-MALLS) analysis, FPCPS adopted a Gaussian coil conformation in 0.1 M NaNO3 solution with 3.75 × 10(6) g/mol of the weight-average molar mass (Mw) and 41.1 nm of the root-mean square radius (Rg(2))z (1/2). Furthermore, both of the polysaccharides were revealed to have strong antioxidant activities by evaluating in DPPH radical, superoxide radicals and hydroxyl radical assay. These data suggest the polysaccharides of Paecilomyces cicadae (Miquel) Samson produced by solid-state fermentation could be explored as potential natural antioxidants.
Journal Article
Optimization Extraction, Preliminary Characterization and Antioxidant Activities of Polysaccharides from Semen Juglandis
by
Wang, Yanbin
,
Ren, Xueyong
,
Cheng, Junwen
in
antioxidant activities
,
Antioxidants
,
Antioxidants - chemistry
2016
The optimization extraction process, preliminary characterization and antioxidant activities of polysaccharides from Semen Juglandis (SJP) were studied in this paper. Based on the Box-Behnken experimental design and response surface methodology, the optimal extraction conditions for the SJP extraction were obtained as follows: temperature 88 °C, extraction time 125 min and ratio of liquid to solid 31 mL/g. Under these conditions, experimental extraction yield of SJP was (5.73 ± 0.014)% (n = 5), similar to the predicted value of 5.78%. Furtherly, the purified SJP obtained from SJP extract by DEAE-52 and Sephacryl S-100 chromatography was analyzed to be rhamnose, galacturonic acid, galactose, arabinose and fucose in the molar ratio of 1:6.34:1.38:3.21:1.56. And the weight-average molecular weight and radius of gyration of the purified SJP in 0.1 M NaCl were determined to be 2.76 × 104 g/mol and 122 nm by SEC-MALLS, respectively. More importantly, it exhibited appreciable antioxidant activities compared to the standard Vc, such as DPPH radical scavenging activity (IC50 0.21 mg/mL), strong reducing power, ABTS radical scavenging activity (IC50 0.29 mg/mL), and hydroxyl radical scavenging activity (IC50 0.38 mg/mL). These results indicate that SJP may be useful for developing functional health products or natural antioxidant.
Journal Article
Molecular Characterization and Bioactivities of a Novel Polysaccharide from Phyllostachys pracecox Bamboo Shoot Residues
2023
Dietary carbohydrates are unexploited in the by-products of economically valuable Phyllostachys pracecox bamboo shoots. A residue-derived polysaccharide (PBSR1) was aqueously extracted from the processing waste of this bamboo shoot species. Its primary structure and advanced conformation were elucidated by a combined analysis of spectroscopy, chromatography, 2D nuclear magnetic resonance, laser light scattering and atomic microscopy. The results indicated PBSR1 was a triple-helix galactan consisting of →6)-β-D-Galp and →3)-β-D-Galp in linear with an 863 KD molecular weight (Mw). The relationship between the radius of gyration (Rg) and intrinsic viscosity ([η]) on Mw were established as Rg = 1.95 × 10−2Mw0.52±0.03 (nm) and [η] = 9.04 × 10−1Mw0.56±0.02 (mL/g) for PBSR1 in saline solution at 25 °C, which indicated it adopted a triple-helix chain shape with a height of 1.60 ± 0.12 nm supported by a red shift of λmax in Congo red analysis. The thermodynamic test (TG) displayed that it had excellent thermal stability for the food industry. Further, those unique structure features furnish PBSR1 on antioxidation with EC50 of 0.65 mg/mL on DPPH· and an ORAC value of 329.46 ± 12.1 μmol TE/g. It also possessed pronounced immunostimulation by up-regulating pro-inflammatory signals including NO, IL-6, TNF-α and IL-1β in murine cells. Our studies provided substantial data for the high-valued application of residues and a better understanding of the structure–function relationship of polysaccharide.
Journal Article
Baseline Survey of Root-Associated Microbes of Taxus chinensis (Pilger) Rehd
by
Sun, Guiling
,
Liu, Hongwei
,
Wu, Jianqiang
in
Anticancer properties
,
Antineoplastic Agents, Phytogenic - biosynthesis
,
Antineoplastic drugs
2015
Taxol (paclitaxel) a diterpenoid is one of the most effective anticancer drugs identified. Biosynthesis of taxol was considered restricted to the Taxus genera until Stierle et al. discovered that an endophytic fungus isolated from Taxus brevifolia could independently synthesize taxol. Little is known about the mechanism of taxol biosynthesis in microbes, but it has been speculated that its biosynthesis may differ from plants. The microbiome from the roots of Taxus chinensis have been extensively investigated with culture-dependent methods to identify taxol synthesizing microbes, but not using culture independent methods.,Using bar-coded high-throughput sequencing in combination with a metagenomics approach, we surveyed the microbial diversity and gene composition of the root-associated microbiomefrom Taxus chinensis (Pilger) Rehd. High-throughput amplicon sequencing revealed 187 fungal OTUs which is higher than any previously reported fungal number identified with the culture-dependent method, suggesting that T. chinensis roots harbor novel and diverse fungi. Some operational taxonomic units (OTU) identified were identical to reported microbe strains possessing the ability to synthesis taxol and several genes previously associated with taxol biosynthesis were identified through metagenomics analysis.
Journal Article
Natural Deep Eutectic Solvent-Assisted Extraction, Structural Characterization, and Immunomodulatory Activity of Polysaccharides from IPaecilomyces hepiali/I
2022
Polysaccharides, which can be affected by different preparations, play a crucial role in the biological function of Paecilomyces hepiali (PHPS) as a health food. To explore high-valued polysaccharides and reduce the negative influence of human involvement, a green tailorable deep eutectic solvent (DES) was applied to optimize the extraction of polysaccharides (PHPS-D), followed by the evaluation of the structural properties and immunomodulation by comparison with the hot-water method (PHPS-W). The results indicated that the best system for PHPS-D was a type of carboxylic acid-based DES consisting of choline chloride and succinic acid in the molar ratio of 1:3, with a 30% water content. The optimal condition was as follows: liquid–solid ratio of 50 mL/g, extraction temperature of 85 °C, and extraction time of 1.7 h. The actual PHPS-D yield was 12.78 ± 0.17%, which was obviously higher than that of PHPS-W. The structural characteristics suggested that PHPS-D contained more uronic acid (22.34 ± 1.38%) and glucose (40.3 ± 0.5%), with a higher molecular weight (3.26 × 10[sup.5] g/mol) and longer radius of gyration (78.2 ± 3.6 nm), as well as extended chain conformation, compared with PHPS-W, and these results were confirmed by AFM and SEM. Immunomodulatory assays suggested that PHPS-D showed better performance than PHPS-W regarding pinocytic activity and the secretion of NO and pro-inflammatory cytokines (IL-6, TNF-α and IL-1β) by activating the corresponding mRNA expression in RAW264.7 cells. This study showed that carboxylic acid-based DES could be a promising tailorable green system for acidic polysaccharide preparation and the valorization of P. hepiali in functional foods.
Journal Article
Heat Transfer Enhancement and Flow Resistance Characteristics in a Tube with Alternating Corrugated-Smooth Segments
2026
To mitigate the inherent high flow resistance of conventional corrugated tubes, a novel design with alternating clockwise/counterclockwise corrugated segments separated by smooth sections is proposed. A 3D numerical model was developed to systematically evaluate the thermal-hydraulic performance of the novel tube against smooth and conventional corrugated tubes, with simulations conducted at Reynolds number (Re) = 9952–35,827. Results show both corrugated configurations enhanced heat transfer significantly relative to the smooth tube: the conventional tube had the highest Nusselt number (Nu) (1.76–1.79 times that of the smooth tube), while the novel tube achieved Nu = 1.61–1.65 times that of the smooth tube. Notably, the novel tube reduced flow resistance substantially—at Re = 35,827, its friction factor (f) was only 65.2% of the conventional tube’s. Parametric studies revealed that more corrugated segments improved heat transfer but increased pressure drop: the 72-12 configuration exhibited the best heat transfer, while the 72-2 configuration reduced f by 40.7%. The novel tube showed superior overall performance (Performance Evaluation Criterion (PEC) > 1.24 for all Re), as corrugated segments generated periodic vortices to disrupt the thermal boundary layer, while smooth segments enabled flow redevelopment and pressure recovery. This study provides valuable guidance for designing high-efficiency, low-resistance heat exchange elements.
Journal Article