Biochemical Detection Research Articles

Based on network pharmacology and molecular docking to explore the protective effect of Epimedii Folium extract on cisplatin-induced intestinal injury in mice.

Background: Epimedii Folium, as a natural botanical medicine, has been reported to have protective effects on intestinal diseases by modulating multiple signaling pathways. This study aimed to explore the potential targets and molecular mechanisms of Epimedii Folium extract (EFE) against cisplatin-induced intestinal injury through network pharmacology, molecular docking, and animal experiments. Methods: Network pharmacology was used to predict potential candidate targets and related signaling pathways. Molecular docking was used to simulate the interactions between significant potential candidate targets and active components. For experimental validation, mice were intraperitoneally injected with cisplatin 20 mg/kg to establish an intestinal injury model. EFE (100, 200 mg/kg) was administered to mice by gavage for 10 days. The protective effect of EFE on intestinal injury was analyzed through biochemical index detection, histopathological staining, and western blotting. Results: Network pharmacology analysis revealed that PI3K-Akt and apoptosis signaling pathways were thought to play critical roles in EFE treatment of the intestinal injury. Molecular docking results showed that the active constituents of Epimedii Folium, including Icariin, Epimedin A, Epimedin B, and Epimedin C, stably docked with the core AKT1, p53, TNF-α, and NF-κB. In verified experiments, EFE could protect the antioxidant defense system by increasing the levels of glutathione peroxidase (GSH-Px) and catalase (CAT) while reducing the content of malondialdehyde (MDA). EFE could also inhibit the expression of NF-κB and the secretion of inflammatory factors, including TNF-α, IL-1β, and IL-6, thereby relieving the inflammatory damage. Further mechanism studies confirmed that EFE had an excellent protective effect on cisplatin-induced intestinal injury by regulating PI3K-Akt, caspase, and NF-κB signaling pathways. Conclusion: In summary, EFE could mitigate cisplatin-induced intestinal damage by modulating oxidative stress, inflammation, and apoptosis.

Ganfule capsule alleviates bile duct ligation-induced liver fibrosis in mice by inhibiting glutamine metabolism

Background: Liver fibrosis is a pathological outcome of a variety of liver diseases, and it can also progress into liver cirrhosis and liver cancer. Specific liver antifibrotic drugs have not been clinically approved yet. Studies have demonstrated the protective effects of Ganfule capsule (GFL) on the liver and its therapeutic potential in hepatic cancer. However, the mechanism of GFL is not clear in the treatment of liver fibrosis. Objective: This article aims to study the protective effect of GFL on liver fibrosis and its possible mechanism. Methods: The cholestatic liver fibrosis model was prepared by subjecting C57BL/6 mice to bile duct ligation (BDL). The GFL groups were treated with different concentrations of GFL for 14 days. Pathological analysis, serum biochemical index detection, metabonomic analysis, immunohistochemistry, Western blot, and real-time PCR were carried out. Results: GFL could alleviate liver injury and liver fibrosis caused by BDL in mice. Metabonomic analysis of mice serum showed postoperative metabolic disorder, which could be alleviated by GFL through glutamine metabolism; valine, leucine, and isoleucine biosynthesis; aminoacyl-tRNA biosynthesis; and other metabolic pathways. GFL affected glutamine metabolism by inhibiting the activity of glutaminase 1 (GLS1). The activation of GLS1 is regulated by the NF-κB pathway, and experiments showed that GFL could inhibit IκB-α and NF-κB p65 phosphorylation. Conclusion: This study confirms the protective effect of GFL on liver injury and shows that GFL inhibits glutamine metabolism, which was correlated with the NF-κB pathway, and eventually alleviates liver fibrosis. These results are conducive to the development of new therapeutic drugs for liver fibrosis.

Surfactant−free synthesis of flower−like Au NPs/Au island hybrid substrate for quantitative SERS detection of pesticide residues on fruit

Surface enhanced Raman scattering (SERS) has been extensively applied in the field of biochemical detection ascribed to its high sensitivity and nondestructive pattern. Nevertheless, the further improvement of such attractive protocol is severely hindered by the absence of enough surface roughness as well as the presence of organic surfactant. Herein, we demonstrated a highly sensitive and robust SERS hybrid substrate composed of plasmonic flower−like Au nanoparticles (FANPs)/Au island with clean surface. The development of this novel FANPs architecture could be attributed to the drastic reduction of Au 3+ ions, which triggered the overgrowth of Au atoms in the absence of surfactant. Meanwhile, the pre-existent Au monolayer on the silicon matrix were found to synchronously grew to Au islands, resulting in the formation of hybrid substrates. The FANPs/Au island hybrid substrate performed satisfactorily while monitoring 4 −mercaptobenzoic acid and gave out an excellent enhancement factor of 6.74 × 10 6 . Particularly, the high sensitivity makes the hybrid substrate a fascinating platform for practical monitoring. In this regard, the in−situ detection of thiabendazole on apple was conducted and a limit of detection low to 8.3 ng/mL was achieved. This high−performance SERS substrate provides more opportunities for appreciable in−situ assay in some practical fields. • A plasmonic flower−like Au NPs (FANPs)/Au island with clean surface was constructed without any surfactant. • An excellent enhancement factor as high as 6.74 × 10 6 was achieved by the FANPs/Au island hybrid substrate. • The in−situ detection of thiabendazole on apple was conducted and the limit of detection was achieved as low as 8.3 ng/mL.

Preparation of green luminescent silicon quantum dots by synergistic method for VB12 detection and antimicrobial property research application

The studies on the preparation of high-quality and long-wavelength-emitting silicon quantum dots and their application in biochemical detections have attracted increasing interests from researchers. In particular, the exploration of the effect of SiQDs and their complex in antibacterial and inhibition of biofilm areas, is of great significance to human health. This paper reports the fast synthesis of green-fluorescent SiQDs (TC-SiQDs, QYs=25%, Em=520 nm) with the synergistic effect of thiourea and catechol through microwave-assisted one-step hydrothermal route. Based on internal filtering effect, TC-SiQDs were then successfully employed as selective probes to detect vitamin B12, with detection range at 0.05–30 μM and limit of detection at 50 nM. Thanks to the excellent biocompatibility and fluorescence property of TC-SiQDs, they have been applied in bacterial imaging. The prepared TC-SiQDs also exhibit certain antibacterial ability with their minimum inhibitory concentration (MIC) against Staphylococcus aureus (S. aureus) at 250 μg/mL, but their inhibitory ability is effective to the growth of S. aureus biofilm only when the concentration reaches 1.3 mg/mL. TC-SiQDs-lysozyme complex were prepared, based on the effects of singlet oxygen, charge effect and lysozyme hydrolysis of peptidoglycan in the cell wall, the complex exhibits high inhibiting activity with MIC against S. aureus at 10 μg/mL and exhibits superior inhibition activity against S. aureus biofilm at a concentration of only 62.5 μg/mL. This paper provides good theoretical and practical basis for the synthesis of long-wavelength emission and ultra-bright SiQDs and their applications in detection, antibacterial and biofilm growth inhibition, and other biomedical fields.

Application of nucleic acid aptamer-based lateral flow assay in microbe detection

<p indent="0mm">Microbial contamination and infection are global issues in the food and environmental fields that seriously threaten human health. Bacteria and fungi can easily cause food spoilage, resulting in diarrhea and vomiting; viruses can infect humans through different transmission routes, causing severe or even fatal harm. Hence, rapid analysis and identification of pathogenic microorganisms and simultaneous detection of multiple types of microbes have become hot research topics in biochemical analysis and molecular diagnosis. The lateral flow assay (LFA) is a simple, rapid, economical, and efficient detection technology with high sensitivity, simple operation, and environmental friendliness. It can provide instant test results under non-laboratory circumstances, hence becoming an ideal choice for point-of-care testing, which has been applied to rapidly detect various targets. The current conventional principle of the LFA is still based on the specific recognition of the antigen by the antibody. However, as a commonly used target recognition molecule in conventional biochemical and medical detection, the application of antibodies also has certain limitations for rapid and accurate identification of certain targets due to strict control of the production and purification process, as well as susceptibility to the interference of the operating environment, pH, temperature, and other conditions, such as long production cycle, high cost, poor stability, and cross-reactivity. Aptamers are a class of single-stranded DNA (ssDNA) or RNA obtained through the systematic evolution of ligands by exponential enrichment (SELEX), which can usually form a stable secondary structure. Aptamers can be folded into a three-dimensional structure through conformational change and interact with the target through conformation complementarity, π-π stacking between aromatic rings, base stacking, electrostatic interaction, and hydrogen bonding. So far, nearly 300 kinds of aptamers have been discovered. As alternatives, aptamers are easy and facile to modify and label with high sensitivity and specificity. Accordingly, the innovative rapid detection technique can be developed by combining the LFA with an aptamer. This aptamer-based LFA technology can be widely used in qualitative, semi-quantitative, and quantitative detection in food safety, environment, clinical, and other fields. Nowadays, most microbe detection methods are constructed based on this approach. The common strategies of aptamer-based LFAs include the sandwich method, competitive method, and adsorption–desorption method. Diverse ingenious materials such as gold nanoparticles and quantum dots have also been proposed for signal read-out. Different signal capture models, such as colorimetric and fluorescence methods, have been applied for sensitive and accurate detection of a single or multiple target microbe. Furthermore, in view of the unique properties of nucleic acid aptamers, several signal amplification methods can be further involved in the LFA to enhance the sensitivity for target detection. This review introduces the use of aptamers with different structural patterns and labeling types in recent years, as well as a variety of methods to detect microbes, especially for the rapid detection of pathogenic bacteria. Based on the excellent characteristics, the aptamer-based LFA presents more flexibility and selectivity for microbe detection with good applicability, specificity, and sensitivity and can better achieve low-cost, rapid detection. This study is expected to provide a reference for developing nucleic acid aptamer-based LFA technologies, especially for efficient and accurate diagnosis of corona virus disease 2019 (COVID-19), exploiting the novel application scope of LFA technology.

Screening and identification of tyrosinase inhibitors in edible plant materials by on-line UPLC-enzyme reactor coupled with UHPLC-FTMS

Tyrosinase plays a primary role in melanin biosynthesis and enzymatic browning of freshly cut fruits and vegetables. Herein, an on-line ultraperformance liquid chromatography diode array detector biochemical detection (UPLC-DAD-BCD) method was established to identify trace amount potent tyrosinase inhibitors and antibrowning agents in complex mixtures. The tyrosinase inhibition activities of some representative compounds were evaluated by using the established method and their chromatography-activity relationships were obtained. Then the proposed UPLC-DAD-BCD method was applied to screen tyrosinase inhibitors in edible herbal extracts and identified two tyrosinase inhibitors in green tea and three in cinnamon. The above active ingredients were determined by ultra-high-performance liquid chromatography linear ion trap/orbitrap high resolution mass spectrometry (UHPLC-FTMS). The on-line UPLC-DAD-BCD in combination with UHPLC-FTMS was confirmed to be a powerful technique to screen and elucidate the active ingredients in complex matrixes and could be applied to evaluate the integrated effects of multiple ingredients against corresponding targets.

Taraxasterol Inhibits Hyperactivation of Macrophages to Alleviate the Sepsis-induced Inflammatory Response of ARDS Rats.

To explore the effect and mechanism of taraxasterol on sepsis-induced acute respiratory distress syndrome (ARDS). Twenty-four male SD rats were randomly divided into four groups: the control group, model (lipopolysaccharide, LPS) group, lipopolysaccharide+taraxasterol (LPS + TXL) group, and lipopolysaccharide+ulinastatin (LPS + UTI) group. The model of sepsis-induced ARDS was established by intraperitoneal injection of LPS. The lung water content of the rats in each group was determined by the dry/wet ratio. Pathology of rat lung tissue was observed through H&E staining. Wright staining was applied to count the number of neutrophils, macrophages, and total cells. ELISA was utilized to measure the levels of the inflammatory factors TNF-α, IL-1β, and IL-6 in bronchoalveolar lavage fluid (BALF). Biochemical detection was adopted to check the levels of myeloperoxidase (MPO), superoxide dismutase (SOD) and catalase (CAT) in lung tissue. Western blotting was performed to check the protein expression of IL-12, iNOS, Arg-1, and Mrc1 in lung tissue. Compared with the LPS group, both taraxasterol and ulinastatin significantly decreased lung tissue water content, improved lung tissue injury, reduced the number of neutrophils, macrophages and total cells, and decreased the level of inflammatory factors. In addition, taraxasterol and ulinastatin also reduced the content of MPO and the expression of IL-12 and iNOS and increased the activity of SOD and CAT as well as the protein expression of Arg-1 and Mrc1. Taraxasterol can suppress macrophage M1 polarization to alleviate the inflammatory response and oxidative stress, thereby treating sepsis-induced ARDS.

Simultaneous Measurement of Humidity and Temperature Based on ZnO-Coated Hollow Core Bragg Fiber

An optical fiber sensor for simultaneous measurement of relative humidity (RH) and temperature is proposed, which is constructed by sandwiching one section of hollow core Bragg fiber (HCBF) between two sections of single mode fiber (SMF). The ultrathin ZnO film is coated on the outer surface of HCBF as humidity-sensitive material. The dips in the transmission spectrum caused by different anti-resonant (AR) modes of HCBF have different sensitivities to the RH and temperature, and then the simultaneous measurement of above two parameters can be realized by solving a cross matrix. For the two dips monitored in the experiments, the sensitivities of the proposed sensor to RH are 0.7 pm/%RH and 16.95 pm/%RH in the range of 46–73 %RH, and the sensitivities to temperature are 25 pm/°C and 26.8 pm/°C in the range of 20-60 °C, respectively. Taking advantage of compact structure, good stability, easy fabrication and the proposed sensor exhibits great potential application in fields of chemical sensors and biochemical detection.

Numerical investigation of plasmonic bowtie nanorings with embedded nanoantennas for achieving high SEIRA enhancement factors

This paper presents the numerical investigation of several complex plasmonic nanostructures — bowtie nanoring and crossed-bowtie nanoring nanoantennas with embedded bowtie nanoantennas and crossed-bowtie nanoantennas — for surface enhanced infrared absorption (SEIRA) spectroscopy-based substrates. The proposed nanostructures exhibit substantially large SEIRA enhancement factor (∼8.1 × 105) compared to previously reported enhancement factor values for bowtie nanoantennas or nanoring antennas. The plasmonic properties of the proposed nanostructures have been studied by the numerical evaluation of the near-field electromagnetic enhancement at resonant plasmon mode excitation wavelengths in the mid-IR spectral regime. The highest SEIRA enhancement of ∼8.1 × 105 occurs at a wavelength of ∼6800 nm (6.8 μm). A substantial electric field enhancement as large as ∼375, corresponding to SEIRA EF of ∼1.4 × 105 is noted even when the minimum gaps between the plasmonic nanostructures is as large as 10 nm, which can easily be fabricated using the conventional nanolithography techniques. The occurrence of several electric field hotspots due to the presence of plasmonic nanoantennas embedded inside the nanorings was observed, as the electric fields are enhanced in the vicinity of the plasmonic nanostructures being proposed. The multiple electric field hotspots in the proposed nanostructures can lead to larger average electric field enhancement as well as the average SEIRA enhancement for these substrates. Moreover, by embedding plasmonic nanoantenna structures inside the bowtie nanorings and crossed-bowtie nanorings, large spectral tunability of plasmon resonance wavelengths is achieved in the spectral regime from 4 μm to 8 μm. This is done by varying a larger number of spectral parameters that are present in these complex nanostructures. This paper also reports a novel configuration of crossed-bowtie nanoring plasmonic structure exhibiting less polarization dependence of the SEIRA enhancement factor. This structure also exhibits tunability of hotspot positions when the direction of the polarization of the incident light is rotated. The proposed structures in this paper can be fabricated by the state-of-the-art nanofabrication technologies. The proposed structures could find potential applications in chemical and biological sensing and biochemical detection of analyte molecules.

A broadband SPR dual-channel sensor based on a PCF coated with sodium-silver for refractive index and temperature measurement

When temperature and refractive index are measured in same spectrum, the measurement range of parameters is generally narrow due to bandwidth limitation. We proposed a sensor for simultaneous measurement of them in a wide wavelength range for this problem. The proposed sensor is a dual-channel structure based on the photonic crystal fiber (PCF) with three air holes and a polished plane. The silver film deposited on the polished plane is responsible for refractive index measurement, and the sodium film and polydimethylsiloxane (PDMS) filled in an air hole for temperature measurement. According to research findings, the two kinds of metal films work in different wavebands, which increases the sensing bandwidth and the measurement range of the parameters to be measured. Numerical results show that when the refractive index of analyte is 1.35 ∼ 1.41 and the temperature is 10 ∼ 60℃, the maximum spectral sensitivity of the sensor is 8400 nm/RIU and 10.2 nm/℃, respectively. The results show that the performance of the sensor is not sensitive to structural parameters. It makes the sensor easy to manufacture. The excellent performances and wide detection range make the proposed sensor have a good application prospect in biochemical detection, environmental monitoring, medical sensing, and other fields.

Natural Graphene Plasmonic Nano‐Resonators for Highly Active Surface‐Enhanced Raman Scattering Platforms

Highly sensitive and uniform three‐dimensional (3D) hybrid heterogeneous structures for use in surface‐enhanced Raman scattering (SERS) experiments were fabricated by sequentially decorating high‐quality, ultra‐clean, graphene quantum dots (GQDs) and Ag nanoparticles (Ag‐NPs) onto 3D‐graphene. Finite‐difference time‐domain calculations and scanning Kelvin probe microscopy were used to verify that the Ag‐NPs/GQDs/3D‐graphene system facilitates substantial electromagnetic enhancement (due to the occurrence of two kinds of “gaps” between the Ag‐NPs that form 3D “hot spots”) and additional chemical enhancement (in detecting some π‐conjugated molecules). The SERS mechanism was explored in further detail via experimental analysis and confirmed by performing theoretical calculations. The large surface area of the 3D substrate (due to the large specific surface areas of the GQDs and 3D‐graphene) results in a better enrichment effect which helps produce lower detection limits. In particular, the detection limits obtained using the Ag‐NPs/GQDs/3D‐graphene platform can reach 10−11 M for rhodamine 6G, 10−10 M for methylene blue and dopamine, and 10−7 M for tetramethylthiuram disulfide and methyl parathion in apple juice (these are superior to most of the results reported using graphene‐based SERS substrates). In summary, the 3D‐platform Ag‐NPs/GQDs/3D‐graphene/Si shows outstanding SERS performance. It therefore has excellent application prospects in biochemical molecular detection and food safety monitoring.

Performance of the Rapidec®Carba NP assay for the detection of different carbapenemases in Klebsiella pneumoniae and Escherichia coli strains

PurposeThe spread of infections caused by Enterobacterales strains resistant to carbapenems is a global public health problem, and early detection of carbapenemases is very important to prevent their spread. The rapid detection of carbapenemase production with the new commercial assay Rapidec® Carba NP test is based on the biochemical detection of imipenem hydrolysis. Our study aims to evaluate the performance of the Rapidec® Carba NP test in OXA-48 positive isolates highly prevalent in our country and also in isolates with more than one carbapenemase gene that have an increased prevalence and to examine whether it can be used for confirmation of carbapenemase positivity in the routine laboratory. MethodsA total of 97 strains of 94 carbapenem-resistant Klebsiella pneumoniae and three carbapenem-resistant Escherichia coli isolated from various clinical specimens were included in the study. The results of the Rapidec® Carba NP assay were compared with those obtained by the multiplex PCR test. ResultsThe sensitivity of the Rapidec® Carba NP test was 97.8% for all carbapenemase-positive isolates. Of 90 PCR positive isolates, one OXA-48 and one OXA-48 ​+ ​NDM positive isolates were negative with Rapidec® Carba NP test. ConclusionsThe positive results detected by the Rapidec® Carba NP test make an important contribution to the early detection of carbapenemase production and infection control practices. Since two carbapenemase positive isolates were found to be negative with the Rapidec® Carba NP test in our study, it was concluded that negative results of carbapenem-resistant isolates obtained with this assay should be confirmed with an additional carbapenemase detection method to exclude false-negative results.

Unbiased Glucose Biosensing Based on a Schottky Junction Comprised of Au Nanoparticle-Decorated TiO2-Coated Al Films

Photoelectrochemical (PEC) biosensors show great potential in biochemical molecular detection due to the advantages of low background noise, high sensitivity, and easy integration. However, the current PEC glucose biosensors are subject to the deficiencies of the relatively large limit of detection, small detectable range of concentration, and requirement of an operation voltage. Herein, we construct an unbiased glucose biosensor both in three- and two-electrode configurations using a glucose oxidase (GOx)-modified Schottky junction comprised of Au nanoparticle (NP)-decorated TiO2-coated Al films. A wide detectable range of concentration (0.3–104 μM) is achieved at relatively zero bias versus the reference electrode in a three-electrode configuration under AM 1.5G illumination along with a fitted sensitivity of 3780 μA mM–1 cm–2 (in the concentration range of 0.3–1.0 μM) and a limit of detection down to 0.05 μM. The photocurrents corresponding to typical interfering substances (e.g., uric acid and ascorbic acid) are less than 10% of that to glucose. Moreover, the constructed sensor achieves almost no attenuation in photocurrent under light ON/OFF circular irradiation for 30 min and shows a photocurrent around 92% of the initial value after 30-day storage in air at room temperature. The satisfactory sensing performance is ascribed to the following three aspects: (1) the optical absorption is enhanced due to the formation of a plane-parallel resonance cavity and the reduced band gap of the TiO2 material, (2) the separation and extraction of the photogenerated carriers are facilitated due to the Al doping and the embedded Schottky junction, and (3) the carrier transfer from the photoelectrode surfaces into the electrolyte is boosted because of the Au NPs and nanostructured GOx decoration. This work provides an alternative route to prepare high-performance and self-powered glucose sensors for diabetes diagnosis.

Double-formant surface plasmon resonance for refractive index sensing by anti-resonance fibers with high sensitivity and wide detection range

Owing to advances in the surface plasmon resonance (SPR) technology, sensors composed of photonic crystal fibers (PCFs) based on SPR have attracted extensive attention. Herein, a double-formant SPR refractive index sensor comprising the anti-resonant fiber (ARF) is designed and analyzed, which can be used to realized high sensitivity and wide detection range. SPR is excited by gold filling in the negative curvature tube and replaces the traditional coating process to reduce the difficulty associated with actual production. Finite element analysis indicates that the optimized ARF-SPR sensor can detect analytes in the refractive index range of 1.310–1.445 with a maximum wavelength sensitivity and amplitude sensitivity of 36400 nm/RIU and 2,573.33 RIU−1, respectively. In addition, the minimum resolution and structural parameter sensitivity is 2.747 × 10-6 RIU and 38 nm/μm. The maximum figure of merit (FOM) is 776.15 RIU−1, and as the refractive index of the analyte increases, the length of the sensor decreases, which suggesting great potential in biochemical detection and geological exploration.

Electrochemical Detection and Spectrophotometry of Dopamine using Commercial Screen-Printed Electrodes

Lab-on-chip is miniaturized devices integrated into a chip which can run one or several analyses which are usually done in laboratory settings, such as biochemical detection. Dopamine is an important neurotransmitter which regulates hormones, control of movement, emotion, attention, and motivation. Excess, lack, and dysregulation of dopamine could cause numbers of diseases and disorders. The technique used to measure and evaluate dopamine usually are expensive to run, require longer time to run, require some technical qualification to run, require expensive equipments, and some are invasive to do. These are the reasons why a lab-on-chip system is needed to make the detection of dopamine concentration faster, easier, and more portable. This paper studied the accuracy of using electrochemical detection to measure the concentration of liquid specimens of dopamine compared to uv/vis spectrophotometry. Electrochemical detection method named cyclic voltammetry was chosen for this study. The hypothesis for this study is that both peak current (ip) and absorbance positively correlate to concentration, therefore both could be used with minimal error margin. For this study, the peak current (ip) and absorbance of different concentrations of liquid specimen of dopamine are measured, and its regression were observed. It was shown that the concentration of liquid specimens of dopamine is linear to both anodic peak current (ipa) and absorbance. Due to the high R2 values of 0.9883, electrochemical detection could be used and implemented to detect dopamine concentration for application of lab-on-chip, as it is more portable and requires less volume of sample compared to spectrophotometry.

Phloridzin Reveals New Treatment Strategies for Liver Fibrosis.

Liver fibrosis is an urgent public health problem which is difficult to resolve. However, various drugs for the treatment of liver fibrosis in clinical practice have their own problems during use. In this study, we used phloridzin to treat hepatic fibrosis in the CCl4-induced C57/BL6N mouse model, which was extracted from lychee core, a traditional Chinese medicine. The therapeutic effect was evaluated by biochemical index detections and ultrasound detection. Furthermore, in order to determine the mechanism of phloridzin in the treatment of liver fibrosis, we performed high-throughput sequencing of mRNA and lncRNA in different groups of liver tissues. The results showed that compared with the model group, the phloridzin-treated groups revealed a significant decrease in collagen deposition and decreased levels of serum alanine aminotransferase, aspartate aminotransferase, laminin, and hyaluronic acid. GO and KEGG pathway enrichment analysis of the differential mRNAs was performed and revealed that phloridzin mainly affects cell ferroptosis. Gene co-expression analysis showed that the target genes of lncRNA were obvious in cell components such as focal adhesions, intercellular adhesion, and cell–substrate junctions and in metabolic pathways such as carbon metabolism. These results showed that phloridizin can effectively treat liver fibrosis, and the mechanism may involve ferroptosis, carbon metabolism, and related changes in biomechanics.

Biochemical characterization and detection of antitumor activity of l-asparaginase from thermophilic Geobacillus kaustophilus DSM 7263T

L-asparaginases, which are oncolytic enzymes, have been used in clinical applications for many years. These enzymes are also important in food processing industry due to their potential in acrylamide-mitigation. In this study, the gene for l-asparaginase (GkASN) from a thermophilic bacterium, Geobacillus kaustophilus, was cloned and expressed in E. coli Rosetta™2 (DE3) cells utilizing the pET-22b(+) vector. The 6xHis-tag attached enzyme was purified and analyzed both biochemically and structurally. The molecular mass of GkASN was determined as ∼36 kDa by SDS-PAGE, Western Blotting, and MALDI-TOF MS analyses. Optimum temperature and pH for the enzyme was determined as 55 °C and 8.5, respectively. The enzyme retained 89% of its thermal stability at 37 °C and 75% at 55 °C after 6 h of incubation. The enzyme activity was inhibited in the presence of Cu2+, Fe3+, Zn2+, and EDTA, while the activity was enhanced in the presence of Mn2+, Mg2+, and thiol group protective agents such as 2-mercaptoethanol and DTT. The structural modeling analysis demonstrated that the catalytic residues of the enzyme were partially similar to other asparaginases. The therapeutic potential of GkASN was tested on hepatocellular carcinoma cells, a solid cancer type with high mortality rate and rapidly increasing incidence in recent years. We showed that the GkASN-induced asparagine deficiency effectively reduced the metastatic synergy in HCC SNU387 cells on a xCELLigence system with differentiated epithelial Hep3B and poorly differentiated metastatic mesenchymal HCC SNU387 cells.

Graphene‐assisted synthesis NH3 gas sensor based on silicon photonics crystal fiber and surface plasmon resonance

ObjectiveIn this article, we theoretically simulated a silicon core-based photonics crystal fiber combined with the Au/graphene coating thin-film to surround the fiber-air-holes with a plasmonic active medium for sensing NH3 gas concentrations. MethodsBy means of our previous research experiences and the related theory, the complex refractive index of graphene under different concentrations of NH3 exposing was analyzed and calculated by using the finite element method. ResultThe sensing average sensitivity of 0.0269 nm/ppm for the proposed NH3-gas sensor was theoretically predicted for the concentration of NH3 in the range from 1 ppm to 1000 ppm. In addition, the proposed photonics crystal fiber sensor can be extended into the other field applications, such as medical diagnostics, bio-chemical detection etc.

Trace biochemical detection based on whispering gallery mode microcavity lasers

Trace biochemical detection based on whispering gallery mode microcavity lasers

Route to flexible metamaterial terahertz biosensor based on multi-resonance dips.

A flexible terahertz (THz) metamaterial biosensor is theoretically and experimentally investigated. The metamaterial unit cell of the periodic structure array was simply composed of three non-overlapping cut wires with different length parameters on a flexible thin-film (parylene-C) to improve sensitivity. The biosensor sample was fabricated using a lithography process and characterized by a THz time-domain spectroscopy (TDS) system. The metamaterial exhibited multi-resonance dips in transmission spectrum at 0.6-2.0 THz, which can self-correct errors in biosensing. Numerical results show that the Q-factor, figure of merit (FOM) and sensitivity can change in dynamic ranges with the geometric parameters (space and width) of three-cut-wire metamaterial. When space distance was 40 µm and other parameters were default, the sensitivity, FOM and Q-factor reached 710 GHz/RIU (Refractive Index Unit), 9, and 20, respectively. Therefore, through proper design and preparation, the metamaterial can be applied to biochemical detection.