Zeolitic Imidazolate Framework-8 Composite-Based Enzyme-Linked Aptamer Assay for the Sensitive Detection of Deoxynivalenol.

The mycotoxin deoxynivalenol (DON) is a prevalent contaminant in cereals that threatens the health of both humans and animals and causes economic losses due to crop contamination. The rapid and sensitive detection of DON is essential for food safety. Herein, a colorimetric biosensor based on horseradish peroxidase- and gold nanoparticle-encapsulated zeolitic imidazolate framework-8 (HRP&Au@ZIF-8) was developed for the sensitive screening of DON. The synthesized HRP&Au@ZIF-8 probes not only held great potential for signal amplification but also exhibited stable catalytic activity even under extreme conditions, which endowed the biosensor with both good sensitivity and stability. Under the optimized conditions, qualitative measurement of DON can be achieved through visual inspection, and quantitative evaluation can be performed via absorbance measurements at a characteristic wavelength of 450 nm. The proposed method has demonstrated high sensitivity with a linear detection range of 1-200 ng/mL and a detection limit of 0.5068 ng/mL. It also presented good selectivity and reliability. Furthermore, DON in spiked cereal samples has been quantified successfully using this method. This novel approach demonstrates significant potential for the facile and expeditious detection of DON in cereal products and brings us one step closer to enhancing food safety.

Insights into the underpinning effect of graphene in Cu1Mn10 on enhancing the low-temperature catalytic activity for CO oxidation.

CO emission is a critical issue of industrial processes such as steel-smelting, cement manufacturing, and waste incineration. Catalytic oxidation based on Cu-Mn binary catalysts shows great potential for efficient removal of CO, whereas their practical applicability is limited by the inferior low-temperature catalytic activity and the high catalyst cost owing to a substantial quantity of Cu. In this study, doping graphene is designed to adjust the electron transfer capability to improve the low-temperature catalytic activity as well as reduce the amount of Cu, and thereby Cu1Mn10 catalysts doped with slight amounts of graphene (x%G-Cu1Mn10, x is 1∼5) were fabricated. It was found that the introduction of graphene could form effective electron transport channels to enhance the intermetallic interaction and oxygen vacancy generation, thus improving the low-temperature catalytic performance of the Cu1Mn10 catalyst. Among all the catalysts, 4%G-Cu1Mn10 exhibited the highest activity, achieving CO conversion of 92% at 110 °C at a weight hourly space velocity of 120,000 mL/(g∙h). The introduction of graphene also enabled the catalyst with excellent catalytic activity and stability at a relative humidity of 70%. Attractively, 4%G-Cu1Mn10 can be further loaded into the polyester fabric, presenting great application potentials in the effective elimination of CO during the dust removal process since the flue gas temperature in the dust collector is just around the T90% and the catalyst that is inside of fabric fiber rather than on the fabric surface can be rarely influenced by the dust. In general, doping graphene provides a facile method to enhance the low-temperature activities of the Cu-Mn binary catalysts and cut down the use of valuable Cu, showing great application potential.

Rapid detection of multiple antibiotics in chicken samples via a fluorescence nanobiosensor coupled with a homemade fluorescence analyzer.

Antibiotic residues in foods pose a serious threat to human health. However, routine analysis techniques require bulky laboratory instruments and skilled personnel or give single-channel analysis results, exhibiting low practicality. Here, we explored a rapid and easy-to-use detection system combining a fluorescence nanobiosensor with a homemade fluorescence analyzer for the simultaneous identification and quantification of multiple antibiotics. The nanobiosensor assay worked based on the targeted antibiotics competing with signal labels of antigen-quantum dots (IQDs) to bind with recognition elements of antibody-magnetic beads (IMBs). The fluorescence signals of IMB-unbound IQDs in a magnetically separated supernatant, related to antibiotic concentration, were automatically collected and processed by our self-designed and homemade fluorescence analyzer which integrated mechanical control hardware (consisting of a mechanical arm, a ten-channel rotary bench, and an optical detection unit) and user control software (installed on a built-in laptop). The fluorescence analyzer enabled the analysis of 10 samples within 5 min in one round and permitted the real-time uploading of sample data to the cloud. By employing three QDs with emission wavelengths of 525 nm, 575 nm, and 625 nm, this multiplex fluorescence biosensing system demonstrated great sensitivity and accuracy for simultaneously analyzing enrofloxacin, tilmicosin, and florfenicol in chicken samples with detection limits of 0.34 µg kg-1, 0.7 µg kg-1, and 0.16 µg kg-1, respectively. Moreover, the biosensing platform performed well in a wealth of chicken samples covering various breeds from three Chinese cities. This study identifies a generic and user-friendly multiplex biosensor platform with significant potential for use in food safety and regulation.

NH2-MIL-125(Ti)/Reduced Graphene Oxide Enhanced Electrochemical Detection of Fenitrothion in Agricultural Products.

The abuse of organophosphate pesticides causes serious threats to human health, which threatens approximately 3 million people and leads to more than 2000 deaths each year. Therefore, it is necessary to determine the residue of fenitrothion (FT) in environmental and food samples. Herein, we developed a non-enzymatic electrochemical sensor with differential pulse voltammetry signal output to determine FT in model solutions and spiked samples. Delicately, the sensor was designed based on the fabrication of hydrothermally synthesized titanium-based metal-organic frameworks (MOFs) material (NH2-MIL-125(Ti))/reduced graphene oxide (RGO) (NH2-MIL-125(Ti)/RGO) nanocomposites for better target enrichment and electron transfer. The peak response of differential pulse voltammetry for FT under optimized conditions was linear in the range of 0.072-18 µM with the logarithm of concentrations, and the detection limit was 0.0338 µM. The fabricated sensor also demonstrated high stability and reproducibility. Moreover, it exhibited excellent sensing performances for FT in spiked agricultural products. The convenient fabrication method of NH2-MIL-125(Ti)/RGO opens up a new approach for the rational design of non-enzymatic detection methods for pesticides.

An electrochemical immunosensor based on prussian blue@zeolitic imidazolate framework-8 nanocomposites probe for the detection of deoxynivalenol in grain products.

The presence of deoxynivalenol (DON) in grains poses a threat to human health, which is critical for sensitive detection of DON. In this electrochemical immunosensor, zeolitic imidazolate framework-8 (ZIF-8) loaded with Prussian blue (PB) nanoparticles was coated by polydopamine (PDA) as a redox probe. The high porosity of ZIF-8, the unique electrochemical activity of PB and the outstanding electrical conductivity of PDA improved the sensitivity of the immunosensor. Under the optimized conditions, the peak current in differential pulse voltammetry displayed a good linear relationship over DON concentrations in a range of 0.1-5000 pg mL-1 with a detection limit of 0.0186 pg mL-1. In addition, the immunosensor also had good selectivity and stability. Good recoveries of 85.67 to 118.00 % have been achieved for the detection of DON in spiked grain products. This new strategy exhibits great potential for simple and rapid detection of DON in grain and feed products.

Unilateral lingual nerve and hypoglossal nerve injury caused by a novel laryngeal mask airway: a case report

Abstract Cranial nerve injury by a laryngeal mask airway is rare but a serious complication. The nerve injuries must be prevented during the intubation using a laryngeal mask airway. We report a female patient who complained of tongue numbness, slurred speech, and slight difficulty in swallowing solid food after a hand surgery. She was then diagnosed with unilateral lingual nerve and hypoglossal nerve injuries. Extreme head rotation, relatively small oral cavity, and wide rigid composition at the lower part of the novel laryngeal mask probably resulted in cranial nerve injury.

Portable and durable sensor based on porous MOFs hybrid sponge for fluorescent-visual detection of organophosphorus pesticide.

Pesticide residues have raised serious public concern towards agriculture, environment and food safety. Recently, metal-organic frameworks (MOFs) have been employed as promising recognition and signal generation elements in sensors for pesticide detection. However, the general format of tiny particles with poor dispersity brings obstacles to detection operation and the improvement of sensing performance. Here, we report a sensor based on porous MOFs hybrid sponge for fluorescent-visible detection of methyl parathion. Benefiting from the intermediate of adhesive and porous fibrin film, MOFs are loaded with good dispersion and accessibility, thereby endowing the sensor with a rapid response time of 10-min, a wide linear detection range of 50-2500 µg L-1, and a low limit of detection of 4.95 µg L-1. Moreover, the hybrid sensor presented superior durability and anti-interference ability to the detection in complex conditions, including organic solvents, acidic solution, high temperature, and even chemical interferences. This hybrid not only provides a new construction strategy for a nanomaterial-based sensor, but also permits a portable and durable route for the detection.

Chemical and electrochemical conversion of magnetic nanoparticles to Prussian blue for label-free and refreshment-enhanced electrochemical biosensing of enrofloxacin.

Magnetic biosensor takes advantage of rapid and facile magnetic separation/collection of targets, however, generally relies on additional signal labels to generate signal in a tedious and high-cost way. Here, we proposed a chemical and electrochemical conversion (C-ECC) method to develop a label-free electrochemical magnetic biosensor to detect antibiotics enrofloxacin (ENR). The C-ECC method integrates the chemical decomposition of magnetic beads (MBs) to release ironic ions and the simultaneous electrochemical deposition of Prussian blue (PB) analogs through the reaction of ironic ions and co-existing K4Fe(CN)6. Unlike conventional method that relies on the physical magnetic property of MBs, the C-ECC method fully exploited the chemical/electrochemical properties of MBs to produce electrochemically active PB to generate signal, thus endowing MBs with dual roles in both sample treatment and signal generation. The incorporation of chemical and electrochemical conversion produced more PB with higher electroactivity when compared with sole chemical or electrochemical conversion. Moreover, an interesting electrochemical refreshment (ER) was designed to remove insulative species on the electrode surface to improve electroactivity of electrode and benefit amperometric detection significantly. Under optimized conditions, the C-ECC-based biosensor presented limit of detection (LOD) of 4.17 pg mL-1 for ENR, which is lower than most analogs, as well as satisfactory specificity. The biosensor also performed well in fish and chicken meat samples, with LODs lower than maximum residue limits of national standards. The C-ECC method may create a new way to design magnetic sensors and contribute to rapid, facile and sensitive detection in agriculture/food, clinic diagnosis and environmental monitoring.

A CRISPR-Cas12a-powered magnetic relaxation switching biosensor for the sensitive detection of Salmonella.

Magnetic relaxation switching (MRS) biosensors are attractive in the field of food safety owing to their simplicity and high signal-to-noise ratio. But they are less in sensitivity and stability caused by the insufficient crosslinking or non-specific binding of magnetic nanoparticles (MNPs) with targets. To address this problem, the CRISPR-Cas12a system was introduced into an MRS biosensor for the first time, to precisely control the binding of two types of MNPs with sizes of 130 nm (MNP130) and 30 nm (MNP30), for the sensitive detection of Salmonella. Delicately, the biosensor was designed based on the different magnetic properties of the two sizes of MNPs. The target Salmonella activated the collateral cleavage activity of the CRISPR-Cas12a system, which inhibited the binding of the two sizes of MNPs, resulting in an increase of unbound MNP30. After separating MNP130-MNP30 complexes and MNP130 from MNP30, the free MNP30 left in solution acted as transverse relaxation time (T2) signal reporters for Salmonella detection. Under optimized conditions, the CRISPR-MRS biosensor presented a limit of detection of 1.3 × 102 CFU mL-1 for Salmonella, which is lower than most MRS biosensor analogues. It also showed satisfactory specificity and performed well in spiked chicken meat samples. This biosensing strategy not only extends the reach of the CRISPR-Cas12a system in biosensors but also offers an alternative for pathogen detection with satisfactory sensitivity.

Overexpression of SmSCR1 Promotes Tanshinone Accumulation and Hairy Root Growth in Salvia miltiorrhiza.

Lipid-soluble tanshinone is one of the main bioactive substances in the medicinal plant Salvia miltiorrhiza, and its medicinal demand is growing rapidly. Yeast extract (YE) modulates the tanshinone biosynthesis, but the underlying regulatory network remains obscure. In this study, a YE-responsive transcriptional factor Scarecrow1 (SCR1) was identified in S. miltiorrhiza from the YE-induced transcriptome dataset. SmSCR1 is located in the nucleus. Overexpression of SmSCR1 in S. miltiorrhiza roots resulted in a significantly higher accumulation of tanshinone than the control, with the highest 1.49-fold increase. We also detected upregulation of tanshinone biosynthetic genes, SmSCR1 and SmHMGR1, and distinct alteration of growth and development of the hairy roots in the overexpression lines compared to the control. An inverse phenotype was observed in SmSCR1-SRDX suppression expression lines. We found that SmSCR1 can bind to the promoter of SmCPS1 to induce its expression. This study provides new insight into the regulatory mechanism on the growth and development of hairy roots, tanshinone accumulation, and the metabolic engineering of bioactive compounds in S. miltiorrhiza.

Monovalent Antigen-Induced Aggregation (MAA) Biosensors Using Immunomagnetic Beads in Both Sample Separation and Signal Generation for Label-Free Detection of Enrofloxacin.

Exploring new functions of nanomaterials can help facilitate the development of biosensors for the detection of antibiotics. Herein, a new detection modality based on monovalent antigen-induced aggregation (MAA) of immunomagnetic beads (IMBs) was proposed for rapid and label-free detection of enrofloxacin (ENR), which endowed IMBs with the abilities of both sample separation and signal generation. In the presence of ENR, the initially well-dispersed IMBs were aggregated and the degree of aggregation was in a concentration-dependent manner. After exploring the mechanism underlying IMB aggregation and investigating the key parameters affecting it, a label-free biosensing platform was developed for rapid and sensitive detection of ENR. Based on the significant differences in the magnetic separation speed and size between the aggregated and well-dispersed IMBs, two methods were proposed for quantitatively determining ENR, i.e., measuring the turbidity of the IMB supernatant after magnetic separation for a given time and visualizing and calculating the grayscale value of the aggregated IMBs trapped on the surface of a nitrocellulose membrane. A three-dimensional (3D)-printed syringe was designed and fabricated for automatic filtration of IMBs. This immunosensor allowed for sensitive detection of ENR in less than 15 min without any labels. It exhibited a satisfactory limit of detection of 0.79 ng mL-1 and showed the feasibility for ENR detection of spiked chicken meat with recovery rates ranging from 74.8 to 98.3%. The MAA immunosensor can act as a promising tool to detect trace levels of ENR and has the potential to be applied to complex food samples.

Unilateral lingual nerve and hypoglossal nerve injury caused by a novel laryngeal mask airway: a case report.

Cranial nerve injury by a laryngeal mask airway is rare but a serious complication. The nerve injuries must be prevented during the intubation using a laryngeal mask airway. We report a female patient who complained of tongue numbness, slurred speech, and slight difficulty in swallowing solid food after a hand surgery. She was then diagnosed with unilateral lingual nerve and hypoglossal nerve injuries. Extreme head rotation, relatively small oral cavity, and wide rigid composition at the lower part of the novel laryngeal mask probably resulted in cranial nerve injury.

Biosensors for rapid detection of Salmonella in food: A review.

Salmonella is one of the main causes of foodborne infectious diseases, posing a serious threat to public health. It can enter the food supply chain at various stages of production, processing, distribution, and marketing. High prevalence of Salmonella necessitates efficient and effective approaches for its identification, detection, and monitoring at an early stage. Because conventional methods based on plate counting and real-time polymerase chain reaction are time-consuming and laborious, novel rapid detection methods are urgently needed for in-field and on-line applications. Biosensors provide many advantages over conventional laboratory assays in terms of sensitivity, specificity, and accuracy, and show superiority in rapid response and potential portability. They are now recognized as promising alternative tools and one of the most on-site applicable and end user-accessible methods for rapid detection. In recent years, we have witnessed a flourishing of studies in the development of robust and elaborate biosensors for detection of Salmonella in food. This review aims to provide a comprehensive overview on Salmonella biosensors by highlighting different signal-transducing mechanisms (optical, electrochemical, piezoelectric, etc.) and critically analyzing its recent trends, particularly in combination with nanomaterials, microfluidics, portable instruments, and smartphones. Furthermore, current challenges are emphasized and future perspectives are discussed.

Electroacupuncture Improved Chronic Cerebral Hypoperfusion-Induced Anxiety-Like Behavior and Memory Impairments in Spontaneously Hypertensive Rats by Downregulating the ACE/Ang II/AT1R Axis and Upregulating the ACE2/Ang-(1-7)/MasR Axis.

Electroacupuncture (EA) can effectively alleviate anxiety disorders and memory impairments caused by various neurodegenerative diseases; however, the molecular mechanisms underlying its neuroprotective effects are unclear. Previous studies have shown that the renin-angiotensin system (RAS) comprises of two axes with mutual antagonism: the classical angiotensin converting enzyme/angiotensin II/angiotensin II type 1 receptor (ACE/Ang II/AT1R) axis and the protective angiotensin converting enzyme 2/angiotensin-(1-7)/Mas receptor (ACE2/Ang-(1-7)/MasR) axis. In this study, we observed that chronic cerebral hypoperfusion (CCH) mediated anxiety-like behavior and memory impairments in spontaneously hypertensive rats (SHR) via upregulation of the hippocampal classical axis (ACE/Ang II/AT1R) and the partial hippocampal protective axis (ACE2/Ang-(1-7)). However, Ang II levels were much higher than those of Ang-(1-7), indicating that the ACE/Ang II/AT1R axis plays a dominant role in the comorbidity of CCH and hypertension. Moreover, candesartan cilexetil (Canc) and perindopril (Peril) were used as positive control drugs. We found that EA, Canc, and Peril attenuated CCH-induced anxiety-like behavior and memory impairments in SHR, potentially via downregulation of the hippocampal classical axis (ACE/Ang II/AT1R) and upregulation of the whole hippocampal protective axis (ACE2/Ang-(1-7)/MasR). These results suggest that EA therapy for CCH with hypertension may be mediated by two hippocampal RAS axes.

Overexpression of BcHsfA1 transcription factor from Brassica campestris improved heat tolerance of transgenic tobacco.

Heat shock proteins (HSPs) are a type of conserved molecular chaperone. They exist extensively in plants and greatly contribute to their survival under heat stress. The transcriptional regulation factor heat shock factor (HSF) is thought to regulate the expression of Hsps. In this study, a novel gene designated BcHsfA1 was cloned and characterized from Brassica campestris. Bioinformatic analysis implied that BcHsfA1 belongs to the HsfA gene family and is most closely related to HsfA1 from other plants. Constitutive overexpression of BcHsfA1 significantly improved heat tolerance of tobacco seedlings by affecting physiological and biochemical processes. Moreover, the chlorophyll content of transgenic tobacco plants was significantly increased compared with wild type after heat stress, as were the activities of the important enzymatic antioxidants superoxide dismutase and peroxidase. BcHsfA1 overexpression also resulted in decreased malondialdehyde content and comparative electrical conductivity and increased soluble sugar content in transgenic tobacco plants than wild-type plants exposed to heat stress. Furthermore, we identified 11 candidate heat response genes that were significantly up-regulated in the transgenic lines exposed to heat stress. Together, these results suggested that BcHsfA1 is effective in improving heat tolerance of tobacco seedlings, which may be useful in the development of new heat-resisitant B. campestris strains by genetic engineering.

ß-Endorphin attenuates collagen-induced arthritis partially by inhibiting peripheral pro-inflammatory mediators.

The classical analgesic pathway of opioids by binding their receptors in the nervous system is well known. However, little is known regarding opioid analgesia through the anti-inflammatory pathway. The present study aimed to investigate the analgesic and anti-inflammatory effect of ß-endorphin on inflammatory pain. A rat model of collagen-induced arthritis (CIA) was generated by intradermal injection of bovine type II collagen. Rats were divided into the CIA + saline group and the CIA + ß-endorphin group, in which rats were intraperitoneally injected with ß-endorphin once every other day from day 18 following the injection of CII until day 28. Thermal hyperalgesia as determined by tail flick latency (TFL), as well as paw arthritis index and swelling. Tumor necrosis factor (TNF)-α, interleukin (IL)-1ß and IL-6 mRNA expression in synovial tissue and their protein levels in paw inflammatory tissue were measured. The rat CIA model was successfully induced as indicated by the significantly decreased TFL, increased paw arthritis index and percentage of swelling on day 18. ß-endorphin treatment significantly increased the TFL, while decreasing the paw arthritis index and swelling in CIA rats. It also significantly downregulated TNF-α and IL-1ß mRNA expression in synovial tissue and their protein levels in inflammatory tissue of the paws of CIA rats, while it had no significant effect on the levels of IL-6. These results indicated that ß-endorphin suppresses peripheral pro-inflammatory mediators in collagen-induced arthritis, which may contribute to its analgesic effect.

Disseminated Intravascular Coagulation Developing After Cranioplasty.

Disseminated intravascular coagulation (DIC) developing after cranioplasty, a skull reconstructive surgical procedure, is very rare. The presently reported patient underwent cranioplasty for cranial trauma under general anaesthesia using titanium prostheses. Her laboratory data was unremarkable. She underwent three operations, each complicated by excessive postoperative bleeding. Although the patient received massive blood transfusions, but no cryoprecipitate coagulum was given during the first two re-operations, and excessive bleeding was evident. Laboratory data showed PT prolongation, APTT prolongation, thrombocytopenia and elevation of the D-dimer level, suggestive of DIC. After the third re-operation, the patient received cryoprecipitate coagulum, and there was no apparent bleeding. Administration of cryoprecipitate coagulum for excessive bleeding postcranioplasty may be required in view of this rare complication.

Analgesic roles of peripheral intrinsic met-enkephalin and dynorphin A in long-lasting inflammatory pain induced by complete Freund's adjuvant in rats.

Previous studies have focused on strategies for pain relief based on the peripheral opioid system. However, little is known with regard to the profile of the peripheral opioid system in long-lasting inflammatory pain. In the current study, the intrinsic changes of the peripheral opioids were investigated in long-lasting inflammatory pain. A rat model of complete Freund's adjuvant (CFA)-induced inflammatory pain was established. Paw swelling and thermal hyperalgesia (paw withdrawal latency, PWL) were analyzed until day 18 after the CFA injection. The levels of peripheral opioids and their upstream inducers, corticotrophin-releasing factor (CRF) and interleukin (IL)-1ß, were measured, and validation experiments were performed using opioid receptor antagonists. Long-lasting inflammatory pain was successfully induced in the rats, as shown by the significantly increased paw swelling and decreased PWLs. On day 18 after the CFA injection, the IL-1ß levels were significantly elevated, while CRF remained at a normal level in the paw inflammatory tissue. In addition, met-enkephalin (Met-ENK) and dynorphin A (DYN A) levels were significantly increased, while the ß-endorphin level remained normal. Local intraplantar administration of δ- and κ-opioid receptor antagonists resulted in more substantial pain, but did not significantly affect the PWLs of the normal control rats. Therefore, the results indicated that the increased levels of local Met-ENK and DYN A in CFA-induced long-lasting inflammatory pain may be involved in peripheral intrinsic analgesia.

[Anti-inflammatory and synovial-opioid system effects of electroacupuncture intervention on chronic pain in arthritic rats].

OBJECTIVE: To observe the analgesic effect of electroacupuncture (EA) on collagen-induced arthritis (CIA) rats and its regulating effect on inflammation reaction and the endogenous opioid system of synovial tissues. Methods A total of 30 healthy male Wistar rats were randomly divided into a control group, a model group and an EA group, 10 rats in each one. The chronic pain model of CIA rats was made by cattle type-II collagen in the model group and EA group. Rats in the EA group were treated with EA at "Zusanli" (ST 36) and "Kunlun" (BL 60) for 30 min from 16th day after model establishment, once a day for consecutive 10 days. Rats in the control group did not receive any treatment. Rats in the model group were treated with fixation as the EA group. Threshold of pain, arthritis index, paw swelling were measured before model establishment and 16 d, 20 d, 23 d and 25 d after model establishment. The levels of beta-endorphin (ß-END), met-enkephalin (met-ENK), dynorphin A (Dyn A) were measured by radioimmunoassay; the mRNA expressions of mu opioid receptor (MOR), kappa opioid receptor (KOR) and delta opioid receptor (DOR) in synovial tissues of CIA rats were detected by I quantitative polymerase chain reaction (qPCR). RESULTS: Compared with the control group, threshold of pain was reduced (all P<0. 01), arthritis index was increased (all P<0. 01) and paw swelling was increased (all P<0. 01) in the model group on the 16th day, 20th day, 23rd day, 25th day after model establishment. Compared with the model group, the threshold of pain was increased in the EA group (all P<0. 01), arthritis index and paw swelling were reduced (all P<0. 01) on the 23rd day and 25th day after model establishment. Compared with the control group, the level of Dyn A in synovial tissues of CIA rats was increased in the model group (P<0. 01); the mRNA expressions of MOR, KOR and DOR were down-regulated lower than 0. 5 fold of normal level. Compared with the model group, the level of ß-END in synovial tissues of the knee joint was increased in the EA group (P<0. 05), and the mRNA expressions of MOR, KOR and DOR in synovial tissues of CIA rats were up-regulated more than 2 folds of normal level. CONCLUSION: The intervention of EA on chronic pain of CIA rats is superior, which is likely to be related with effects of EA on anti-inflammation and up-regulation of synovial tissue ß-END and MOR, KOR, DOR.