Formation and Application of Polymer Spherulite-like Patterns of Halloysite Nanotubes by Evaporation-Induced Self-Assembly.

Halloysite nanotubes (HNTs) are one-dimensional clay nanomaterials featuring distinct tubular structures and unique surface charges. HNTs can readily form ordered assembly structures under specific conditions, which shows significant potential applications in optical and biological fields. In this study, sodium hexametaphosphate (SHMP) was employed as a stabilizer to prepare polymer spherulite-like patterns via the evaporation-induced self-assembly (EISA) technique. The incorporation of SHMP enhanced the repulsion force among the nanotubes and the surface potential, which facilitated the orderly deposition of HNTs. The influence of HNT concentration, SHMP concentration, drying temperature, and substrate on the polymer spherulites-like pattern has been investigated in detail. The optimal conditions were 10 wt % HNT dispersion, 0.6 wt % SHMP concentration, 30 °C as drying temperature, and glass substrates. In addition, by changing the droplet volume and shape of the three-phase contact line, patterns of different sizes and shapes can be achieved. Bovine serum albumin or metal salt compounds were incorporated into the dispersion of SHMP-modified HNTs, which altered the charge and the self-assembled patterns with different area ratios. Thus, this technology can be utilized for the analysis and comparison of protein and metal ion concentration accurately. This study creates the correlation between the structural parameters and the preparation process involved in creating polymer spherulite-like patterns of modified HNTs and offers fresh insights into potential applications for the self-assembly of HNT droplets in the realms of anticounterfeiting and solution concentration analysis.

Tubercidin inhibits PRRSV replication via RIG-I/NF-κB pathways and interrupting viral nsp2 synthesis.

Porcine reproductive and respiratory syndrome virus (PRRSV) is an RNA virus with constantly emerging recombinant and mutant strains. Because of the high genetic diversity of PRRSV, current vaccines only provide partial protection against the infection of heterologous strains, which makes it a challenge for PRRSV prevention and control. Tubercidin is a naturally extracted compound with potential antiviral properties. However, whether tubercidin has anti-PRRSV ability is unknown. Our study found that tubercidin showed effective antiviral effects on PRRSV replication. In terms of mechanism, tubercidin suppressed PRRSV at the entry, replication, and release steps of the viral life cycle. Additionally, we demonstrated that tubercidin treatment promoted the activation of retinoic acid-inducible gene I and nuclear factor kappa-light-chain-enhancer of activated B cell signaling pathway, thus increasing the type I interferon and inflammatory cytokine expression. Furthermore, tubercidin restrained the viral non-structural protein 2 expression and viral dsRNA synthesis and ultimately inhibited PRRSV replication. Hence, our data showed that tubercidin is promising and has potential antiviral ability against PRRSV replication in vitro. IMPORTANCE: Porcine reproductive and respiratory syndrome (PRRS) is one of the most important swine diseases, which causes huge economic loss worldwide. However, there is no effective therapeutic method for PRRS prevention and control. Here, we found that tubercidin, a naturally extracted adenosine analog, exhibited strong anti-porcine reproductive and respiratory syndrome virus (PRRSV) activity. Mechanically, tubercidin inhibited viral binding, replication, and release. Tubercidin suppressed PRRSV non-structural protein 2 expression, which is important for the formation of replication and transcription complex, leading to the block of viral RNA synthesis and PRRSV replication. Moreover, tubercidin could activate retinoic acid-inducible gene I/nuclear factor kappa-light-chain-enhancer of activated B cell innate immune signaling pathway and increased the expression of interferons and proinflammatory cytokines, which was the other way to inhibit PRRSV replication. Our work evaluated the potential value of tubercidin as an antiviral agent on PRRSV replication and provided a new way to prevent PRRSV replication in vitro.

Chitin nanocrystals stabilized liquid metal for highly stretchable and anti-freeze hydrogels as flexible strain sensor.

Conductive hydrogels show extensive applications in flexible electronics and biomedical areas, but it is a challenge to simultaneously achieve high mechanical properties, satisfied electrical conductivity, good biocompatibility, self-recovery and anti-freezing properties through a simple preparation method. Herein, chitin nanocrystals (ChNCs) were employed to encapsulate liquid metal nanoparticles (LMNPs) to ensure the dispersion stability of LMNPs in a hydrogel system composed of polyacrylamide (PAM) and polyvinyl alcohol (PVA). The synergistic effect of ChNCs-stabilized LMNPs imparts remarkable conductivity to the hydrogel, making it an effective strain sensor for human motion. With 1 % LMNPs, the composite hydrogel stretches up to 2100 %, showing excellent stretchability. Under 10 cycles of 200 % strain, hysteresis loop curves overlap, indicating outstanding fatigue resistance. The hydrogel exhibits remarkable self-recovery, enduring 1400 % deformation without rupture. In addition, its effective antifreeze properties result from immersion in a glycerol-water solvent. Even at -20 °C and 60 °C, the hydrogel maintains stable, reproducible resistance changes at 150 % tensile strain. Therefore, the high-performance conductive hydrogel containing ChNCs stabilized LM has promising applications in flexible wearable sensing devices.

Effects of different electrostatic field intensities assisted controlled freezing point storage on water holding capacity of fresh meat during the early postmortem period.

In this study, the effect of different intensity electrostatic fields on the water holding capacity (WHC) of fresh meat during the early postmortem period in controlled freezing point storage (CFPS) were investigated. Significantly lower cooking loss were found in low voltage electrostatic field (LVEF) and high voltage electrostatic field (HVEF) compared to the control group (CK) (p < 0.05). The myofibril fragmentation index and microstructure results suggested that the sample under HVEF treatment remained relatively intact. It has been revealed that the changes in actomyosin properties under electrostatic field treatment groups were due to the combination and dissociation of actomyosin binding into myofilament concentration, which consequently affects the muscle WHC. The study further demonstrated that the electrostatic field, especially HVEF, might increase the WHC of fresh meat by affecting the distribution of water molecules and physiochemical properties of actomyosin during the early postmortem period.

Changes in water holding capacity of chilled fresh pork in controlled freezing-point storage assisted by different modes of electrostatic field action.

Electrostatic field-assisted low-temperature preservation is considered a novel technology, which provides an effective means of extending the shelf-life of meat. This study aimed to investigate the effects of different output time modes of a high voltage electrostatic field (HVEF) on the water holding capacity (WHC) of chilled fresh pork during controlled freezing-point storage. Under a direct current HVEF generator, chilled fresh pork samples were treated by the single, interval, or continuous HVEF treatment, with a control check group receiving no HVEF treatment. It was determined that the WHC of the continuous HVEF treatment higher than the control check group. This difference was proven by analyzing the moisture content, storage loss, centrifugal loss, cooking loss, and nuclear magnetic resonance imaging. Furthermore, the mechanism behind HVEF-assisted controlled freezing-point storage reduced the moisture loss was conducted by examining the changes in the hydration characteristics of myofibrillar protein. The study revealed that myofibrillar proteins exhibit high solubility and low surface hydrophobicity under continuous HVEF. Additionally, continuous HVEF has been demonstrated to effectively maintain the higher WHC and lower hardness of myofibrillar protein gel by inhibiting the water molecule migration. The demonstration of these results showcases the effectiveness of electrostatic fields for the future physical preservation of meat.

Urban cultural heritage is mentally restorative: an experimental study based on multiple psychophysiological measures.

Introduction: Urban cultural heritage sites bear the cultural functions of a city, hold spiritual and cultural value, can recall emotional memories, and serve the cultural leisure activities of the residents. Urban cultural heritage sites can help citizens perceive a sense of belonging and a feeling of relaxation, but whether and to what extent cultural heritage sites affect mental health remains unknown. Methods: Based on attention restoration theory, multiple research methods are adopted in this study to examine the impact of cultural heritage on human restorative mechanisms. Five representative cultural heritage sites from the cultural heritage-rich city of Xi'an are selected as the research object. In addition, a questionnaire survey and physiological experiments are conducted. Perceived restorative scale, skin conductance response, heart rate variability, and eye movement data while viewing photographs of the cases are collected from the participants. Results: Results show that cultural heritage sites have psychophysiological restorative effects, which are especially significant in the fascination dimension. Moreover, historical buildings can promote the restorative effects of cultural heritage sites. Discussion: This finding may lead to new conservation and innovation planning strategies considering the mental health effects of cultural heritage.

Bergamottin Inhibits PRRSV Replication by Blocking Viral Non-Structural Proteins Expression and Viral RNA Synthesis.

The porcine reproductive and respiratory syndrome virus (PRRSV) causes economic losses in the swine industry worldwide. However, current vaccines cannot provide effective protection against PRRSV, and PRRSV-specific treatments for infected herds are still unavailable. In this study, we found that bergamottin showed strong inhibitory effects against PRRSV replication. Bergamottin inhibited PRRSV at the stage of the replication cycle. Mechanically, bergamottin promoted the activation of IRF3 and NF-κB signaling, leading to the increased expression of proinflammatory cytokines and interferon, which inhibited viral replication to some extent. In addition, bergamottion could reduce the expression of the non-structural proteins (Nsps), leading to the interruption of replication and transcription complex (RTC) formation and viral dsRNA synthesis, ultimately restraining PRRSV replication. Our study identified that bergamottin possesses potential value as an antiviral agent against PRRSV in vitro.

Serum polybrominated diphenyl ether exposure and influence factors in blood donors of Wuxi adults from 2013 to 2016.

Polybrominated diphenyl ethers (PBDEs) have been used as brominated flame retardants worldwide and are correlated with extensive environmental pollution and human health concerns. This study is aimed at analyzing the concentrations of PBDEs and at evaluating their temporal trends among a population of blood donors (n = 33) over a 4-year period. A total of 132 serum samples were used for PBDE detection. Nine PBDE congeners were quantified in serum samples by gas chromatography with mass spectrometry (GC-MS). The median concentrations of Σ9PBDEs in each year were 33.46, 29.75, 30.85, and 35.02 ng/g lipid, respectively. Most of the PBDE congeners showed a downward trend from 2013 to 2014 and then increased after 2014. No correlations between age and PBDE congener concentrations were observed, while concentrations of each congener and Σ9PBDE were nearly always lower in females than in males, especially in BDE-66, BDE-153, BDE-183, BDE-190, and Σ9PBDE. We also found that the intake of fish, fruit, and eggs in the daily diet was related to the exposure level of PBDEs. Our results suggest that, as deca-BDE is still produced and used in China, diet is an important exposure pathway for PBDEs, and follow-up studies will be required to improve our understanding of the behaviors of PBDE isomers in humans and the exposure levels.

Sustained release of magnesium and zinc ions synergistically accelerates wound healing.

Skin wounds are a major medical challenge that threaten human health. Functional hydrogel dressings demonstrate great potential to promote wound healing. In this study, magnesium (Mg) and zinc (Zn) are introduced into methacrylate gelatin (GelMA) hydrogel via low-temperature magnetic stirring and photocuring, and their effects on skin wounds and the underlying mechanisms are investigated. Degradation testing confirmed that the GelMA/Mg/Zn hydrogel released magnesium ions (Mg2+) and zinc ions (Zn2+) in a sustained manner. The Mg2+ and Zn2+ not only enhanced the migration of human skin fibroblasts (HSFs) and human immortalized keratinocytes (HaCats), but also promoted the transformation of HSFs into myofibroblasts and accelerated the production and remodeling of extracellular matrix. Moreover, the GelMA/Mg/Zn hydrogel enhanced the healing of full-thickness skin defects in rats via accelerated collagen deposition, angiogenesis and skin wound re-epithelialization. We also identified the mechanisms through which GelMA/Mg/Zn hydrogel promoted wound healing: the Mg2+ promoted Zn2+ entry into HSFs and increased the concentration of Zn2+ in HSFs, which effectively induced HSFs to differentiate into myofibroblasts by activating the STAT3 signaling pathway. The synergistic effect of Mg2+ and Zn2+ promoted wound healing. In conclusion, our study provides a promising strategy for skin wounds regeneration.

LGP2 Promotes Type I Interferon Production To Inhibit PRRSV Infection via Enhancing MDA5-Mediated Signaling.

Porcine reproductive and respiratory syndrome virus (PRRSV) is one of the most important pathogens in the global pig industry, which modulates the host's innate antiviral immunity to achieve immune evasion. RIG-I-like receptors (RLRs) sense viral RNA and activate the interferon signaling pathway. LGP2, a member of the RLR family, plays an important role in regulating innate immunity. However, the role of LGP2 in virus infection is controversial. Whether LGP2 has a role during infection with PRRSV remains unclear. Here, we found that LGP2 overexpression restrained the replication of PRRSV, while LGP2 silencing facilitated PRRSV replication. LGP2 was prone to interact with MDA5 and enhanced viral RNA enrichment and recognition by MDA5, thus promoting the activation of RIG-I/IRF3 and NF-κB signaling pathways and reinforcing the expression of proinflammatory cytokines and type I interferon during PRRSV infection. Meanwhile, there was a decreased protein expression of LGP2 upon PRRSV infection in vitro. PRRSV Nsp1 and Nsp2 interacted with LGP2 and promoted K63-linked ubiquitination of LGP2, ultimately leading to the degradation of LGP2. These novel findings indicate that LGP2 plays a role in regulating PRRSV replication through synergistic interaction with MDA5. Moreover, targeting LGP2 is responsible for PRRSV immune evasion. Our work describes a novel mechanism of virus-host interaction and provides the basis for preventing and controlling PRRSV. IMPORTANCE LGP2, a member of retinoic acid-inducible gene I (RIG-I)-like receptors (RLRs), shows higher-affinity binding to RNA and work synergism with RIG-I or MDA5. However, LGP2 has divergent responses to different viruses, which remains controversial in antiviral immune responses. Here, we present the detailed process of LGP2 in positively regulating the anti-PRRSV response. Upon PRRSV infection, LGP2 was prone to bind to MDA5 and enhanced MDA5 signaling, manifesting the enrichment of viral RNA on MDA5 and the activation of downstream IRF3 and NF-κB, which results in increased proinflammatory cytokines and type I interferon expression, ultimately inhibiting PRRSV at the early stage of infection. Moreover, PRRSV Nsp1 and Nsp2 interacted with LGP2 via ubiquitin-proteasome pathways, thus blocking LGP2-mediated immune response. This research helps us understand the host recognition and innate antiviral response to PRRSV infection by neglected pattern recognition receptors, which sheds light on the detailed mechanism of virus-host interaction.

Evaluating spatial accessibility of cultural urban land use by using improved 2SFCA method in Xi'an, China.

With rapid urbanization, contradictions between rapid economic development and a lack of spiritual culture become increasingly complicated. Accessibility is a useful spatial quantitative index to evaluate the spiritual and cultural construction of the city. Amongst various accessibility methods, the two-step floating catchment area (2SFCA) method is suitable for evaluating cultural urban land use (CULU) based on its advantage of flexibility and rationality. This study selects Xi'an as the representative ancient city. Based on comparing accessibility results between different travel modes (walk, bus, subway, and total), and analyzing through statistics, Z-score, and comparison of classification, comparison of a particular area, we obtain the characteristics of CULU accessibility in Xi'an. Firstly, for different travel modes, the distribution of CULU accessibility value in Xi'an is imbalanced, and the accessibility value of bus and subway is closely related to public transport resources. Secondly, CULU in Xi'an has apparent features of being dense in the center, sparse in the suburbs, and lack edge, which correspond to the development of the city. Finally, about 60% accessibility value is contributed by historical CULU, which reflects the typical characteristics of Xi'an as an ancient city with rich historical resources. This study profoundly analyses the attributes of CULU in Xi'an and provides essential data for decision-makers. Furthermore, it gives a significant exploration for building a CULU evaluation system in the future.

pH Stimuli-Responsive, Rapidly Self-healable Coatings Enhanced the Corrosion Resistance and Osteogenic Differentiation of Mg-1Ca Osteoimplant.

Mg-Ca alloys have emerged as a promising research direction for biomedical implants in the orthopedic field. However, their clinical use is deterred by their fast corrosion rate. In this work, a pH stimuli-responsive silk-halloysite (HNT)/phytic acid (PA) self-healing coating (Silk-HNT/PA) is constructed to slow down the corrosion rate of Mg-1Ca alloy and its cell viability and osteogenic differentiation ability are enhanced. The Silk-HNT/PA coating exhibits appealing active corrosion protection, by eliciting pH-triggerable self-healing effects, while simultaneously affording superior biocompatibility and osteogenic differentiation ability. Moreover, in vivo studies by histological analysis also demonstrate better osseointegration for the Silk-HNT/PA coated Mg-1Ca alloy. In summary, the Silk-HNT/PA coating in the present study has great potential in enhancing the biomedical utility of Mg alloys.

Reflection and transmission of coupled elastic waves by a semiconduction interlayer with consideration of photothermal effects.

The wave propagation problem through an inhomogeneous semiconduction slab sandwiched between two thermoelastic half-spaces is studied in this paper. Due to the photothermal effects and photoacoustic effects, the multiple physical fields coupled waves are generated in the semiconduction interlayer. For the inhomogenous semiconduction slab of finite thickness, the multiple physical fields coupled waves cannot be expressed explicitly. Instead, the state vector is defined, and the state transfer equation is derived to obtain the transfer matrix of the inhomogeneous slab. The reflection and transmission coefficients as well as the dissipation energy are estimated. The influences of the photothermal effects and photoacoustic effects are discussed based on the numerical results. It is found that the photothermal effects and photoacoustic effects result in some different vibration modes and associated propagation modes. The gradient profiles of the inhomogeneous interlayer have complicated influences on the reflection and transmission behaviors and can be well-designed to adjust the propagation behavior.

3D-Printed PCL/Zn scaffolds for bone regeneration with a dose-dependent effect on osteogenesis and osteoclastogenesis.

Polycaprolactone (PCL) is a polymer material suitable for being prepared into porous scaffolds used in bone tissue engineering, however, insufficient osteogenic ability and mechanical strength limit its application. Zinc (Zn) alloy with proper mechanical strength and osteogenesis is a promising biodegradable metal that have attracted much attention. Herein, we combined the advantages of PCL and Zn by fabricating PCL/Zn composite scaffolds with different Zn powder contents (1 â€‹wt%, 2 â€‹wt%, 3 â€‹wt%) through fused deposition modelling. The â€‹mechanical property, cytocompatibility and Zn â€‹ions release â€‹behavior of PCL/Zn scaffolds were analyzed â€‹in vitro. The osteogenesis and osteoclastogenesis properties of the scaffolds were evaluated by being implanted into Sprague-Dawley rats calvaria defect. Results showed that the PCL/Zn scaffolds exhibited improved mechanical properties and cytocompatibility compared with the pure PCL scaffolds. At 8 weeks after in vivo implantaion, the addition of Zn powder promoted new bone formation, in a dose-dependent manner. The scaffolds with 2 â€‹wt% Zn displayed the best osteogenic effect, while the osteogenic effect was slightly reduced in the scaffolds with 3 â€‹wt% Zn. In the studied Zn contents, the PCL/Zn scaffolds gradually promoted osteoclastogenesis with increasd Zn content. In the 3 â€‹wt% Zn group, TRAP-positive cells were observed on the newly formed bone edges around the scaffolds. These dose-dependent effects were verified in vitro using MC3T3-E1 and RAW264.7 â€‹cells. Finally, we revealed that Zn2+ regulated osteogenesis and osteoclastogenesis by activation of the Wnt/ß-catenin and NF-κB signalling pathways, respectively.

Identification of Policies Based on Assessment-Optimization Model to Confront Vulnerable Resources System with Large Population Scale in a Big City.

The conflict between excessive population development and vulnerable resource (including water, food, and energy resources) capacity influenced by multiple uncertainties can increase the difficulty of decision making in a big city with large population scale. In this study, an adaptive population and water-food-energy (WFE) management framework (APRF) incorporating vulnerability assessment, uncertainty analysis, and systemic optimization methods is developed for optimizing the relationship between population development and WFE management (P-WFE) under combined policies. In the APRF, the vulnerability of WFE was calculated by an entropy-based driver-pressure-state-response (E-DPSR) model to reflect the exposure, sensitivity, and adaptability caused by population growth, economic development, and resource governance. Meanwhile, a scenario-based dynamic fuzzy model with Hurwicz criterion (SDFH) is proposed for not only optimizing the relationship of P-WFE with uncertain information expressed as possibility and probability distributions, but also reflecting the risk preference of policymakers with an elected manner. The developed APRF is applied to a real case study of Beijing city, which has characteristics of a large population scale and resource deficit. The results of WFE shortages and population adjustments were obtained to identify an optimized P-WEF plan under various policies, to support the adjustment of the current policy in Beijing city. Meanwhile, the results associated with resource vulnerability and benefit analysis were analyzed for improving the robustness of policy generation.

Evaluation of reopening strategies for educational institutions during COVID-19 through agent based simulation.

Many educational institutions have partially or fully closed all operations to cope with the challenges of the ongoing COVID-19 pandemic. In this paper, we explore strategies that such institutions can adopt to conduct safe reopening and resume operations during the pandemic. The research is motivated by the University of Illinois at Urbana-Champaign's (UIUC's) SHIELD program, which is a set of policies and strategies, including rapid saliva-based COVID-19 screening, for ensuring safety of students, faculty and staff to conduct in-person operations, at least partially. Specifically, we study how rapid bulk testing, contact tracing and preventative measures such as mask wearing, sanitization, and enforcement of social distancing can allow institutions to manage the epidemic spread. This work combines the power of analytical epidemic modeling, data analysis and agent-based simulations to derive policy insights. We develop an analytical model that takes into account the asymptomatic transmission of COVID-19, the effect of isolation via testing (both in bulk and through contact tracing) and the rate of contacts among people within and outside the institution. Next, we use data from the UIUC SHIELD program and 85 other universities to estimate parameters that describe the analytical model. Using the estimated parameters, we finally conduct agent-based simulations with various model parameters to evaluate testing and reopening strategies. The parameter estimates from UIUC and other universities show similar trends. For example, infection rates at various institutions grow rapidly in certain months and this growth correlates positively with infection rates in counties where the universities are located. Infection rates are also shown to be negatively correlated with testing rates at the institutions. Through agent-based simulations, we demonstrate that the key to designing an effective reopening strategy is a combination of rapid bulk testing and effective preventative measures such as mask wearing and social distancing. Multiple other factors help to reduce infection load, such as efficient contact tracing, reduced delay between testing and result revelation, tests with less false negatives and targeted testing of high-risk class among others. This paper contributes to the nascent literature on combating the COVID-19 pandemic and is especially relevant for educational institutions and similarly large organizations. We contribute by providing an analytical model that can be used to estimate key parameters from data, which in turn can be used to simulate the effect of different strategies for reopening. We quantify the relative effect of different strategies such as bulk testing, contact tracing, reduced infectivity and contact rates in the context of educational institutions. Specifically, we show that for the estimated average base infectivity of 0.025 ([Formula: see text]), a daily number of tests to population ratio T/N of 0.2, i.e., once a week testing for all individuals, is a good indicative threshold. However, this test to population ratio is sensitive to external infectivities, internal and external mobilities, delay in getting results after testing, and measures related to mask wearing and sanitization, which affect the base infection rate.

Complete chloroplast genome of Prunus fasciculata (Rosaceae), a species native to western North America.

Prunus fasciculata is a wild species of Prunus native to western North America. Here, we reported the complete chloroplast (cp) genome of P. fasciculata (GenBank accession number: MW160273). The cp genome was 157,986 bp long, with a large single-copy (LSC) region of 86,068 bp and a small single-copy (SSC) region of 19,166 bp separated by a pair of inverted repeats (IRs) of 26,376 bp. It encodes 129 genes, including 84 protein-coding genes, 37 tRNA genes, and eight ribosomal RNA genes. We also reconstructed the phylogeny of Prunus sensu lato using maximum-likelihood (ML) method, including our data and previously reported cp genomes of related taxa. The phylogenetic analysis confirmed the sister group relationship between P. fasciculata and the remaining subg. Prunus.

Quantitative analysis of pyoluteorin in anti-fungal fermentation liquor of Pseudomonas species by capillary zone electrophoresis with UV-vis detector.

This paper investigated potential utility of capillary zone electrophoresis (CZE) for very succinct but robust quantitative analysis of pyoluteorin (Plt) in anti-fungal fermentation liquor of Pseudomonas species. The experimental conditions for the separation and quantification of Plt were optimized at first. The optimized conditions are: 80 mmol/L pH 8.40 Gly-NaOH buffer, 51 cm total length (42 cm effective) and 75 microm I.D. capillary, 230 nm wavelength, 25 kV, 13 mbar 10s pressure sample injection and 24 degrees C air-cooling. Under the optimized conditions, the migration times of Plt and the internal standard phenobarbital are 2.09 and 2.49 min, respectively, the linear response of Plt concentration ranges from 5.0 to 1000 microg/mL with high correlation coefficient (r=0.99977, n=9), the limits of detection (LOD) and quantification (LOQ) for Plt are 0.66 and 2.2 microg/mL, the precision values (expressed as R.S.D.) of intra- and inter-day are 1.19-1.94% and 1.55-6.21%, respectively, the recoveries of Plt at three concentration levels of 750, 250 and 50 microg/mL range from 90.31% to 97.85% and to 98.96%, respectively. The developed method can be well used for the quantification of Plt in the fermentation liquor.