Immobilized enzyme-based enzyme electrode biosensors, characterized by high sensitivity and efficiency, strong specificity, and compact size, demonstrate broad application prospects in life science research, disease diagnosis and monitoring, etc. Immobilization of enzyme is a critical step in determining the performance (stability, sensitivity, and reproducibility) of the biosensors. Random immobilization (physical adsorption, covalent cross-linking, etc.) can easily bring about problems, such as decreased enzyme activity and relatively unstable immobilization. Whereas, directional immobilization utilizing amino acid residue mutation, affinity peptide fusion, or nucleotide-specific binding to restrict the orientation of the enzymes provides new possibilities to solve the problems caused by random immobilization. In this paper, the principles, advantages and disadvantages and the application progress of enzyme electrode biosensors of different directional immobilization strategies for enzyme molecular sensing elements by specific amino acids (lysine, histidine, cysteine, unnatural amino acid) with functional groups introduced based on site-specific mutation, affinity peptides (gold binding peptides, carbon binding peptides, carbohydrate binding domains) fused through genetic engineering, and specific binding between nucleotides and target enzymes (proteins) were reviewed, and the application fields, advantages and limitations of various immobilized enzyme interface characterization techniques were discussed, hoping to provide theoretical and technical guidance for the creation of high-performance enzyme sensing elements and the manufacture of enzyme electrode sensors.

BACKGROUND:Polylactic acid(PLA)has good biocompatibility and a controllable degradation rate and is currently widely used in biomedical engineering.However,PLA has shortcomings such as low mechanical strength and insufficient biological activity,which limits its further application in bone tissue engineering. OBJECTIVE:To construct polylactic acid/polydopamine/tantalum(PLA/PDA/Ta)bone tissue engineering scaffolds,and explore their biosafety and in vitro osteogenesis. METHODS:A PLA scaffold with a porous structure was prepared through liquid crystal display light-curing technology.PLA/PDA scaffolds and PLA/PDA/Ta scaffolds were prepared by soaking PLA scaffolds in dopamine solution and dopamine-tantalum nanoparticle solution,respectively.The microstructure and water contact angle of scaffolds were characterized.MC3T3-E1 cells were co-cultured with PLA,PLA/PDA,and PLA/PDA/Ta scaffolds,respectively,and CCK-8 assay and live/dead cell staining were performed.After osteogenic differentiation,alkaline phosphatase,alizarin red staining,and osteogenic gene detection were performed. RESULTS AND CONCLUSION:(1)The scanning electron microscope results exhibited that the three kinds of prepared scaffolds had an interconnected porous three-dimensional structure,and the average pore diameter was 200 μm.The water contact angle of PLA/PDA/Ta scaffolds was lower than that of PLA and PLA/PDA scaffolds(P<0.05).(2)CCK-8 assay showed that compared with PLA and PLA/PDA scaffolds,PLA/PDA/Ta scaffolds could promote cell proliferation(P<0.05).Live/dead cell staining showed good cell proliferation in the three groups.(3)Alkaline phosphatase and alizarin red staining showed that compared with PLA and PLA/PDA scaffolds,PLA/PDA/Ta scaffolds could promote the expression of alkaline phosphatase and the formation of mineralized nodules.RT-qPCR showed that compared with PLA and PLA/PDA scaffolds,PLA/PDA/Ta scaffolds could enhance the mRNA expression of cell bone morphogenetic protein,Runx-2,and type I collagen(P<0.05,P<0.01).(4)The results showed that the PLA/PDA/Ta scaffold had excellent osteogenic activity and the ability to promote cell proliferation.

Dysphagia is a common complication of stroke. Combining the principles of traditional Chinese medicine with modern research findings， it is proposed that "latent pathogen in the cerebral collaterals" constitutes the core pathogenesis of post-stroke dysphagia （PSD）. In clinical practice， treatment is tailored according to the location of PSD. During the oral stage， when the pathogen invades the face and mouth， resulting in excessive salivation， acupoints are primarily selected from the foot shaoyin （少阴） kidney channel， in combination with ren mai （任脉） ， du mai （督脉）， chong mai （冲脉） and the spleen channel， to replenish essence and fill the marrow， dispel dampness and unblock the channels. In the pharyngeal stage， as the pathogen obstructs the throat， disrupting normal swallowing， the therapy emphasizes dredging the shaoyang （少阳） channel and warming and tonifying the jueyin （厥阴） channel， by taking acupoints mainly from the hand and foot shaoyang channels， along with the jueyin channels， so as to soothe the liver and promote bile secretion， regulate and harmonize qi and blood. During the esophageal stage， where the pathogen damages the esophagus， impeding food passage， the treatment emphasizes activating the yangming （阳明） channels and regulating taiyin （太阴） channels； acupoints are mainly selected from the foot yangming stomach channel， along with the taiyin channels， aiming to warm yang， unblock the channels and dispel stasis.

ObjectiveTo investigate how Xiaoyao Shukun decoction （XYSKD） regulates the formation and release of neutrophil extracellular traps （NETs） via the phosphatidylinositol 3-kinase （PI3K）/protein kinase B （Akt）/mammalian target of rapamycin （mTOR） signaling pathway， thereby reducing inflammation， inhibiting the excessive proliferation of fibroblasts in pelvic adhesion tissue， decreasing adhesion and fibrosis， and repairing the tissue damage in sequelae of pelvic inflammatory disease （SPID）. MethodsA total of 84 Wistar rats were randomly allocated into seven groups： blank， model， XYSKD （8 mg·kg^-1）， mTOR agonist （10 mg·kg^-1）， mTOR agonist + XYSKD （10 mg·kg^-1+8 mg·kg^-1）， mTOR inhibitor （2 mg·kg^-1）， and mTOR inhibitor + XYSKD （2 mg·kg^-1+8 mg·kg^-1）. The rat model of SPID was constructed by starvation， fatigue， and ascending Escherichia coli infection. After 14 days of drug intervention， the ultrastructure of fibroblasts in the pelvic adhesion tissue was observed by transmission electron microscopy. The general morphology of the uterus， fallopian tube， and ovary was observed by laparotomy. The levels of interleukin-1β （IL-1β）， interleukin-17 （IL-17）， and tumor necrosis factor-α （TNF-α） in the peritoneal flushing fluid were determined by enzyme-linked immunosorbent assay （ELISA）. The expression of myeloperoxidase （MPO） and citrullinated histone 3 （H3） in the fallopian tube was detected by immunofluorescence. Western blot and Real-time quantitative polymerase chain reaction （Real-time PCR） were employed to determine the relative protein and mRNA levels， respectively， of neutrophil elastase （NE）， intercellular adhesion molecule-1 （CD54）， α-smooth muscle actin （α-SMA）， H3， PI3K， and Akt. ResultsCompared with the blank group， the model group presented a large number of collagen fibers in bundles， numerous cytoplasmic folds of fibroblasts， reduced or absent mitochondrial cristae， and disordered and expanded endoplasmic reticulum. By laparotomy， extensive pelvic congestion， connective tissue hyperplasia， thickening and hardening of the tubal end near the uterus， and tubal and ovarian adhesion or cyst were observed in the model group. In addition， the model group showed raised levels of IL-1β， IL-17， and TNF-α in the peritoneal flushing fluid （P<0.01）， increased average fluorescence intensities of MPO and H3 （P<0.01）， and up-regulated protein and mRNA levels of NE， H3， CD54， PI3K， and Akt （P<0.01）. Compared with the model group， the mTOR agonist group showed increased fibroblasts and cytoplasmic folds， absence of mitochondrial cristae， endoplasmic reticulum dilation， and evident collagen fiber hyperplasia. Pelvic adhesions were observed to cause aggravated damage to the uterine， fallopian tube， and ovarian tissues. The levels of IL-1β， IL-17， and TNF-α in the peritoneal lavage fluid elevated （P<0.01） and the average fluorescence intensities of MPO and H3 enhanced （P<0.01） in the mTOR agonist group. In contrast， the XYSKD group and the mTOR inhibitor group showcased decreased fibroblasts and collagen fibers， alleviated mitochondrial crista loss and endoplasmic reticulum dilation， improved morphology and appearance of the uterine， fallopian tube， and ovarian tissues， lowered levels of IL-1β， IL-17， and TNF-α in the peritoneal lavage fluid （P<0.01）， decreased average fluorescence intensities of MPO and H3 （P<0.01）， and down-regulated protein and mRNA levels of NE， H3， CD54， PI3K， and Akt （P<0.05）. Compared with the mTOR agonist group， the mTOR agonist + XYSKD group showed alleviated pathological changes in the pelvic tissue， declined levels of IL-1β， IL-17， and TNF-α （P<0.01）， decreased average fluorescence intensities of MPO and H3 （P<0.01）， and down-regulated protein levels of NE， H3， CD54， α-SMA， p-PI3K/PI3K， and p-Akt/Akt （P<0.01） and mRNA levels of NE， H3， CD54， α-SMA， PI3K， and Akt （P<0.01）. Compared with the mTOR inhibitor group， the mTOR inhibitor + XYSKD group demonstrated reduced pathological severity of the pelvic tissue， reduced levels of IL-1β， IL-17， and TNF-α （P<0.01）， decreased average fluorescence intensities of MPO and H3 （P<0.01）， and down-regulated protein and mRNA levels of NE and CD54 （P<0.05）. ConclusionXYSKD can inhibit the excessive formation and release of NETs via PI3K/Akt/mTOR to ameliorate the inflammatory environment and reduce fibrosis and adhesion of the pelvic tissue， thereby playing a role in the treatment of SPID. It may exert the effects by lowering the levels of IL-1β， IL-17， and TNF-α and down-regulating the expression of NE， H3， CD54， α-SMA， PI3K， and Akt in the pelvic adhesion tissue.

ObjectiveTo investigate the infection characteristics of respiratory syncytial virus (RSV) in children with acute respiratory tract infection (ARI) in Pudong New Area, Shanghai, from 2013 to 2023, so as to provide an evidence for the prevention and control of RSV in Shanghai. MethodsChildren who sought medical care at sentinel healthcare facilities in Pudong New Area, Shanghai, between January 2013 and December 2023 and met the case definition of ARI were included in the study. Nasopharyngeal swab samples were collected and tested for viral pathogens using real-time fluorescene PCR, and the clinical information of whom was collected simultaneously. ResultsA total of 4 980 children were included in the ARI surveillance, among whom 231 tested positive for RSV, with an overall detection rate of 4.64%. Of these, 106 cases were type A and 125 were type B. From 2013 to 2023, the detection rate of RSV in children showed an overall trend of initial increase followed by a decline, with higher detection rates in autumn and winter and lower rates in spring and summer. The RSV detection rate gradually decreased with age, with the highest rate observed in children <1 year old, accounting for 16.33% (80/490) of RSV-detection cases. Cough was the most common clinical symptom. Among the RSV-positive cases, 36 involved co-infection with another virus, 6 co-infected with three viruses, and 1 with mixed infection of four viruses. The most frequent co-infection was RSV and human coronavirus. ConclusionChildren under 1 year of age are more susceptible to RSV infection, with cough being the predominant symptom. RSV infection in Pudong New Area, Shanghai, mainly occurs in winter. Targeted prevention and control measures should be taken for children under 1 year old during the winter season to reduce the risk of both RSV infection and co-infection with human coronavirus and influenza virus.

Objective To analyze the factors influencing the occupational health literacy (OHL) level among workers in key industries from the perspectives of both individual workers and enterprises. Methods A total of 32 336 front-line workers from 12 key industries in the secondary industry in Guangdong Province were selected as the research subjects by a stratified cluster random sampling method. Their OHL level was investigated using Occupational Health Literacy Questionnaire of National Key Populations, and the influencing factors were analyzed. Results The OHL level of the research subjects was 48.5%. The OHL level of the research subjects in four dimensions from high to low was basic knowledge of occupational health protection, occupational health practice and behavior, legal knowledge of occupational health, and basic skills of occupational health protection (80.7%, 61.2%, 48.3% and 29.5%, respectively). The multivariable logistic regression analysis showed that the OHL level of female workers was lower than that of males (P<0.05). Lower OHL was also associated with older age, lower education level, lower personal monthly income of workers (all P<0.01). The workers with length of service < 3 years and ≥ 20 years had lower OHL level than those with length of service 3-<10 years and 10-<20 years, respectively (all P<0.05). Workers in larger enterprises had higher OHL levels (all P<0.01). The OHL level of workers in the sixth category of industries with occupational injuries had higher occupational injury risks than those in the third and fourth categories (all P<0.05). The OHL levels of workers in state-owned enterprises, private enterprises, foreign-funded enterprises, and other enterprises were higher than that of workers in public institutions (all P<0.05). Conclusion The influencing factors of workers′ OHL in key industries of the secondary industry include individual factors (gender, age, education level, personal monthly income, length of service) and enterprise factors (enterprise size, enterprise nature and industry injury risk category). Female, older workers, those with lower education or income, and those with short length of service represent priority groups for OHL interventions, while small and micro enterprises are priority units for future workplace health promotion intervention.

ObjectiveBased on the quality evaluation experience of "it is better to have a fragrant and strong aroma" summarized by materia medica of past dynasties， the chemical components of Sojae Semen Nigrum（SSN） and Sojae Semen Praeparatum（SSP） were systematically compared and analyzed， and the main fermentation products in different fermentation time were quantitatively analyzed， so as to clarify the transformation law of internal components in the processing process and provide scientific basis for the modern quality control of SSP. MethodUltra performance liquid chromatography-quadrupole tandem time-of-flight mass spectrometry（UPLC-Q-TOF-MS） was used for the structural identification of the chemical constituents of SSN and SSP， and with the aid of Progenesis QI v2.3 software， the negative ion mode was employed for principal component analysis（PCA） pattern recognition， and the data were analyzed with the aid of orthogonal partial least squares-discriminant analysis（OPLS-DA） for two-dimensional data to obtain S-plot， and components with |P|>0.1 were selected as the differential constituents. The contents of isoflavonoids in SSP during fermentation was determined by UPLC， and the samples were taken every 8 h in the pre-fermentation period and every 2 d in the post-fermentation period， and the dynamic changes of isoflavonoid contents in different fermentation stages were analyzed. The contents of amino acids and nucleosides in SSP and SSN from different fermentation stages were quantitatively analyzed by phenyl isothiocyanate（PITC） pre-column derivatization and high performance liquid chromatography（HPLC） gradient elution， and the contribution of flavor substances to the "delicious" taste of SSP was discussed by taste intensity value（TAV）. ResultA total of 19 kinds of differential components were screened out， mainly soybean saponins and isoflavones， and their contents decreased significantly or even disappeared after fermentation. In the pre-fermentation process of SSP， glycoside bond hydrolysis mainly occurred， and isoflavone glycosides in SSN were degraded and converted into the corresponding aglycones， the content of flavor substances such as amino acids increased gradually. In the post-fermentation process， protein degradation mainly occurred， after 8 d of post-fermentation， the content of isoflavones was basically stable， while the total content of amino acids increased by 8-40 times on average. Different amino acids form the special flavor of SSP， such as the TAV of glutamate is always ahead of other flavor substances， and sweet substances such as alanine and valine have made relatively great contributions to SSP. ConclusionBased on the law of constituent transformation， combined with the traditional evaluation index of "fragrant and strong"， it is difficult to control the fermentation degree of SSP by the existing standards in the 2020 edition of Chinese Pharmacopoeia. It is suggested that description of the characteristics of SSP be refined and changed to "fragrant， delicious and slightly sweet"， and at the same time， the post-fermentation index compounds such as glutamic acid， alanine and valine should be added as the quality control indicators of SSP， so as to standardize the production process and improve the quality of SSP.