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:Eucommia ulmoides has a certain osteogenic effect,which can promote the proliferation and differentiation of osteoblasts.However,it is unclear whether Eucommia ulmoides has effects on alveolar bone formation and Wnt/β-Catenin signaling pathway. OBJECTIVE:To investigate the mechanism by which Eucommia ulmoides promotes alveolar bone formation in ovariectomized rats based on the Wnt/β-Catenin signaling pathway. METHODS:Sixty female Sprague-Dawley rats were selected and randomly divided into five groups:blank control group,sham-operation group,model group,low-dose group Eucommia ulmoides group,and high-dose Eucommia ulmoides group,with twelve rats in each group.Osteoporosis animal models were constructed by bilateral oophorectomy in the model group and the low-dose and high-dose Eucommia ulmoides groups.The sham-operation group underwent the same method to remove adipose tissue of equal mass around the bilateral ovaries.Three months after surgery,the low-and high-dose Eucommia ulmoides groups were given 2.1 g/kg/d and 4.2 g/kg/d Eucommia ulmoides by gavage,respectively.The sham-operation group and model group were given the same amount of physiological saline by gavage.After 12 weeks of drug intervention,the changes in alveolar bone mass of rats in each group were observed through Micro-CT;hematoxylin-eosin staining was used to observe the pathological structural changes of alveolar bone in rats;enzyme linked immunosorbent assay was used to detect the expression levels of alkaline phosphatase and osteocalcin in the serum of rats;western blot was used to detect the expression levels of β-Catenin and Frizzled9 receptor proteins in the alveolar bone of rats;and real-time fluorescence quantitative PCR was used to detect the expression of osteocalcin,Runt-related transcription factor 2(Runx2),alkaline phosphatase,β-catenin,and frizzled9 mRNAs in alveolar bone tissues of rats. RESULTS AND CONCLUSION:Compared with the blank control group,bone volume fraction,trabecular number,trabecular thickness,and bone mineral density were reduced in the model group(P＜0.05),and trabecular separation was elevated(P＜0.05).Pathological observation showed that the arrangement of trabeculae was disordered and irregular,the trabeculae were thinned or broken,and the marrow cavity was enlarged in the model group,with a significant reduction in bone volume;the level of alkaline phosphatase in the serum was increased(P＜0.05),and the level of osteocalcin was decreased(P＜0.05);mRNA expression of alkaline phosphatase,osteocalcin,Runx2,β-catenin,and frizzled9 were decreased(P＜0.05);protein expression of β-Catenin and Frizzled9 was decreased(P＜0.05).Compared with the model group,the low-and high-dose Eucommia ulmoides groups showed an increase in bone volume fraction,trabecular number,trabecular thickness,and bone mineral density(P＜0.05)and a decrease in trabecular separation(P＜0.05).In the low-and high-dose Eucommia ulmoides groups,bone trabeculae were slightly aligned and thickened,with a significant increase in bone mass.Compared with the model group,the serum level of alkaline phosphatase was reduced(P＜0.05)and the serum level of osteocalcin was elevated(P＜0.05)in the low-and high-dose Eucommia ulmoides groups.Compared with the model group,the mRNA expression of alkaline phosphatase,osteocalcin,Runx2,β-catenin,and frizzled9 were increased in the low-and high-dose Eucommia ulmoides groups(P＜0.05).Compared with the model group,the protein expression of Frizzled9 was increased in the low-dose Eucommia ulmoides group(P＜0.05),while the protein expression of β-Catenin and Frizzled9 was increased in the high-dose Eucommia ulmoides group(P＜0.05).Compared with the low-dose Eucommia ulmoides group,the high-dose Eucommia ulmoides group had a more significant improvement in the above indexes.To conclude,Eucommia ulmoides can effectively promote the alveolar bone formation,and its mechanism of action might be related to the activation of the Wnt/β-catenin signaling pathway.

ObjectiveTo explore the mechanism of the Wenyang Jieyu prescription in regulating depression-like behavior in mice after maternal-infant separation combined with secondary stress. MethodsAfter birth， the rats were randomly divided into blank （NC） group， maternal-infant separation （MS） group， restraint stress （RS） group， maternal-infant separation combined with restraint stress （MRS） group， Wenyang group， Jieyu group， Wenyang Jieyu （XSF） group， and minocycline group. Maternal-infant separation was performed on day 5 （PD5）， followed by weaning at PD21 and prophylactic administration. The dose of Wenyang group， Xiaoyao group， XSF group and minocycline group were 5.85， 12.03， 16.71 g·kg^-1 and 50 mg·kg^-1， respectively. Restraint stress was applied on PD90. The model was evaluated using glucose， social interaction， open field， and O-maze behavior tests， as well as high-performance liquid chromatography to measure serotonin， dopamine， and other neurotransmitters. The expression level of ionized calcium-binding adaptor molecule-1 （Iba-1） protein， a marker of hippocampal microglia， was detected by immunohistochemistry. Protein expression levels of Janus kinase 2 （JAK2） and signal transducer and activator of transcription 3 （STAT3） in the hippocampus were analyzed by an automatic protein expression analysis system. Real-time fluorescence quantitative polymerase chain reaction （Real-time PCR） was used to detect mRNA expression levels of M1 markers， JAK2/STAT3 pathway-related genes， and cytokines in hippocampal microglia in each group. ResultsCompared with the NC group， the MRS group exhibited depression-like behavior， with significantly decreased levels of neurotransmitters in the hippocampus （P<0.05， P<0.01）， increased expression of Iba-1 （P<0.01）， and elevated protein levels of JAK2 and STAT3 （P<0.05）. The mRNA expression levels of CD68， CD11b， IL-1β， JAK2， and STAT3 were significantly increased （P<0.01）， while IL-10 mRNA expression was significantly decreased （P<0.01）. Compared with the MRS group， the XSF and minocycline groups showed some improvement in depression-like behavior. In these groups， the hippocampal neurotransmitter content was significantly increased （P<0.05， P<0.01）， and Iba-1 expression was significantly decreased （P<0.01）. The protein levels of JAK2 and STAT3 in the XSF group showed a downward trend. The mRNA expression levels of CD68， CD11b， JAK2， STAT3， and IL-1β in the hippocampus were significantly decreased in the XSF and minocycline groups （P<0.05， P<0.01）， while IL-10 mRNA expression was significantly increased （P<0.05， P<0.01）. ConclusionWenyang Jieyu prescription can regulate depression-like behavior in maternal-infant separation mice combined with secondary stress by inhibiting the polarization of hippocampal microglia to the M1 phenotype. The regulation of hippocampal microglia polarization by Wenyang Jieyu prescription may be associated with the JAK2/STAT3 pathway.

Adipose tissue is a critical energy reservoir in animals and humans, with multifaceted roles in endocrine regulation, immune response, and providing mechanical protection. Based on anatomical location and functional characteristics, adipose tissue can be categorized into distinct types, including white adipose tissue (WAT), brown adipose tissue (BAT), beige adipose tissue, and pink adipose tissue. Traditionally, adipose tissue research has centered on its morphological and functional properties as a whole. However, with the advent of single-cell transcriptomics, a new level of complexity in adipose tissue has been unveiled, showing that even under identical conditions, cells of the same type may exhibit significant variation in morphology, structure, function, and gene expression——phenomena collectively referred to as cellular heterogeneity. Single-cell transcriptomics, including techniques like single-cell RNA sequencing (scRNA-seq) and single-nucleus RNA sequencing (snRNA-seq), enables in-depth analysis of the diversity and heterogeneity of adipocytes at the single-cell level. This high-resolution approach has not only deepened our understanding of adipocyte functionality but also facilitated the discovery of previously unidentified cell types and gene expression patterns that may play key roles in adipose tissue function. This review delves into the latest advances in the application of single-cell transcriptomics in elucidating the heterogeneity and diversity within adipose tissue, highlighting how these findings have redefined the understanding of cell subpopulations within different adipose depots. Moreover, the review explores how single-cell transcriptomic technologies have enabled the study of cellular communication pathways and differentiation trajectories among adipose cell subgroups. By mapping these interactions and differentiation processes, researchers gain insights into how distinct cellular subpopulations coordinate within adipose tissues, which is crucial for maintaining tissue homeostasis and function. Understanding these mechanisms is essential, as dysregulation in adipose cell interactions and differentiation underlies a range of metabolic disorders, including obesity and diabetes mellitus type 2. Furthermore, single-cell transcriptomics holds promising implications for identifying therapeutic targets; by pinpointing specific cell types and gene pathways involved in adipose tissue dysfunction, these technologies pave the way for developing targeted interventions aimed at modulating specific adipose subpopulations. In summary, this review provides a comprehensive analysis of the role of single-cell transcriptomic technologies in uncovering the heterogeneity and functional diversity of adipose tissues.

Objective: To analyze the nucleic acid load of human parvovirus B19 in major commercially available blood products in China, including human albumin, human intravenous immunoglobulin, human rabies immunoglobulin and various coagulation factor products, aiming to provide evidence for improving blood product manufacturing processes and quality control of source plasma. Methods: A total of 98 batches of coagulation factor products were tested for human parvovirus B19 nucleic acid using real-time fluorescent quantitative PCR, including 42 batches of human prothrombin complex, 35 batches of human coagulation factor Ⅷ, and 21 batches of human fibrinogen. Additionally, 6 batches of human albumin, 6 batches of human intravenous immunoglobulin, and 38 batches of human rabies immunoglobulin were tested for human parvovirus B19 nucleic acid. Results: Human parvovirus B19 nucleic acid were undetectable in human albumin, human intravenous immunoglobulin and human rabies immunoglobulin. Among the 98 batches of coagulation factor products tested for human parvovirus B19 nucleic acid, B19 nucleic acid reactivity rate was 69.0% (29/42) for human prothrombin complex batches, but nucleic acid concentration were all significantly lower than 10 IU/mL. The reactivity rate of B19 nucleic acid in 35 batches of human coagulation factor Ⅷ was 48.6% (17/35), with nucleic acid concentration all below 10 IU/mL. The reactivity rate of B19 nucleic acid in 21 batches of human fibrinogen was 61.9% (13/21), with nucleic acid concentration all below 10 IU/mL. Conclusion: No human parvovirus B19 has been detected in human albumin, human intravenous immunoglobulin, or human rabies immunoglobulin. Human parvovirus B19 nucleic acid may exist in commercially available coagulation factor products, highlighting the need for enhanced screening of human parvovirus B19 nucleic acid in these products. It is also recommended that B19 viral nucleic acid testing be conducted on source plasma, particularly for coagulation factor products.

Objective: To analyze the nucleic acid load of human parvovirus B19 in major commercially available blood products in China, including human albumin, human intravenous immunoglobulin, human rabies immunoglobulin and various coagulation factor products, aiming to provide evidence for improving blood product manufacturing processes and quality control of source plasma. Methods: A total of 98 batches of coagulation factor products were tested for human parvovirus B19 nucleic acid using real-time fluorescent quantitative PCR, including 42 batches of human prothrombin complex, 35 batches of human coagulation factor Ⅷ, and 21 batches of human fibrinogen. Additionally, 6 batches of human albumin, 6 batches of human intravenous immunoglobulin, and 38 batches of human rabies immunoglobulin were tested for human parvovirus B19 nucleic acid. Results: Human parvovirus B19 nucleic acid were undetectable in human albumin, human intravenous immunoglobulin and human rabies immunoglobulin. Among the 98 batches of coagulation factor products tested for human parvovirus B19 nucleic acid, B19 nucleic acid reactivity rate was 69.0% (29/42) for human prothrombin complex batches, but nucleic acid concentration were all significantly lower than 10 IU/mL. The reactivity rate of B19 nucleic acid in 35 batches of human coagulation factor Ⅷ was 48.6% (17/35), with nucleic acid concentration all below 10 IU/mL. The reactivity rate of B19 nucleic acid in 21 batches of human fibrinogen was 61.9% (13/21), with nucleic acid concentration all below 10 IU/mL. Conclusion: No human parvovirus B19 has been detected in human albumin, human intravenous immunoglobulin, or human rabies immunoglobulin. Human parvovirus B19 nucleic acid may exist in commercially available coagulation factor products, highlighting the need for enhanced screening of human parvovirus B19 nucleic acid in these products. It is also recommended that B19 viral nucleic acid testing be conducted on source plasma, particularly for coagulation factor products.

OBJECTIVE To explore the protective mechanism of amifostine on acute radiation injury mice. METHODS Thirty C57BL/6J mice were randomly divided into normal control group， model group and amifostine group （150 mg/kg）， with 10 mice in each group. Thirty minutes before irradiation， the mice in the amifostine group were intraperitoneally injected with amifostine； normal control group and model group were given constant volume of normal saline intraperitoneally； then acute radiation injury was induced by 4 Gy X-ray radiation in both model group and amifostine group. The white blood cell count （WBC）， platelet count and red blood cell （RBC） count in mice were detected 2 hours before irradiation and on days 1， 4， 7， 10 and 14 after irradiation； the changes in the proportion of WBC （neutrophils， lymphocytes and monocytes） on the 7th day after irradiation were analyzed. The 16S rRNA high-throughput sequencing was used to analyze the structure of gut microbiota in mice feces on the 7th day after irradiation， then its correlation with WBC was analyzed. RESULTS The counts of WBC on the 1st， 4th， 7th and 10th day after irradiation， platelet count on the 10th day after irradiation and RBC count on the 1st day after irradiation in the amifostine group were significantly higher than those in model group （P＜0.05）. Compared with normal control group，β diversity of gut microbiome showed significant change， relative abundance of Firmicutes increased and that of Bacteroidetes decreased in model group. Amifostine could reverse the change in β diversity of gut microbiome， and the relative abundance of Bacteroidetes and Firmicutes. The model group consisted of four distinct species， namely Allobaculum， Erysipelotrichia， Erysipelotrichales and Erysipelotrichaceae， which were significantly negatively correlated with the proportion of peripheral blood lymphocytes （P＜0.01）； amifostine group consisted of two distinct species， namely Lactobacillus murinus and L. crispatus， which were significantly negatively correlated with the proportion of neutrophils （P＜0.05）. CONCLUSIONS Amifostine significantly improves irradiation-induced injury by regulating dysbiosis of LY201816） gut microbiota.

ObjectiveTo investigate the effect of galvanic vestibular stimulation on stroke patients with lateropulsion. MethodsFrom February to October, 2023, 30 stroke patients with lateropulsion in the First Affiliated Hospital of Nanjing Medical University were divided into control group (n = 15) and experimental group (n = 15) randomly. The control group received routine rehabilitation and sham galvanic vestibular stimulation, and the experimental group received routine rehabilitation and true galvanic vestibular stimulation, for two weeks. They were assessed with Scale for Contraversive Pushing (SCP), subjective visual vertical (SVV), Line Cancellation Test (LCT), Star Cancellation Test (SCT), Berg Balance Scale (BBS), Holden Functional Ambulation Category (FAC) and Barthel Index (BI) before and after treatment. ResultsAll the indexes improved in both groups after intervention (|t| > 2.461, Z > 3.000, P < 0.05), except the SVV orientation, SVV certainty and SCT in the control group; while the SCP, SVV certainty, LCT and FAC were better in the experimental group than in the control group (|t| > 2.189, Z = -2.862, P < 0.05), and the differences before and after intervention were better in the experimental group than in the control group (|t| > 2.382, P < 0.05), except LCT. SCP was correlated with SVV orientation, SVV certainty, SCT, BBS, BI and FAC (|r| > 0.381, P < 0.05). ConclusionGalvanic vestibular stimulation can improve the lateropulsion, balance, walking function and activities of daily living in stroke patients, which may be related to improvement for spatial cognitive function, especially vertical perception.

ObjectiveTo explore the syndromes and mechanisms of depression induced by maternal separation （MS） combined with chronic restraint stress （RS） in mice. MethodOn postnatal day 0 （PD0）， the offspring mice were randomized into a blank group （NC） and a modeling group. The mouse model of depression was established by MS+RS for 21 days. After removal of female mice on PD21， the modeled mice were randomized into model， Wenyang， Jieyu， Wenyang Jieyu， and fluoxetine groups， with 15 mice in each group. The sucrose preference， tail suspension， and open field tests were carried out to evaluate the anxiety and depression-like behavior in mice. Enzyme-linked immunosorbent assay was used to measure the adrenocorticotrophic hormone （ACTH） and corticosterone （CORT） levels in mouse plasma. High performance liquid chromatography-electrochemical detector was used to determine the content of monoamine neurotransmitters in the hippocampus. Real-time fluorescence quantitative polymerase chain reaction was employed to determine the mRNA levels of genes in the 5-hydroxytryptamine （5-HT） system， hypothalamic-pituitary-adrenal （HPA） axis， and brain-derived neurotrophic factor （BDNF） signaling pathway in the hippocampus. Immunohistochemistry was employed to determine the expression levels of proteins in the 5-HT system and HPA axis in the hippocampus. The Simple Western system was used to determine the protein levels of BDNF and tyrosine kinase receptor B （TrkB） in the hippocampus. ResultCompared with the NC group， the model group exhibited depression-like behavior， which was significantly relieved by Wenyang Jieyu prescription and fluoxetine. Compared with the NC group， the model group showed elevated levels of CORT and ACTH in the plasma （P<0.01）， which， however， were lowered by Wenyang Jieyu prescription and fluoxetine （P<0.05， P<0.01）. Compared with the NC group， the model group showed inhibited expression of neurotransmitters in the hippocampus （P<0.05， P<0.01）， while Wenyang Jieyu prescription and fluoxetine restored the expression of neurotransmitters （P<0.05， P<0.01）. Compared with NC group， the model group showed inhibition of the 5-HTergic nerve and abnormal activation of the HPA axis， and Wenyang Jieyu prescription and fluoxetine regulated the abnormal state of the 5-HTergic nerve and HPA axis. Compared with NC group， the modeling down-regulated the mRNA and protein levels of BDNF and TrkB in the hippocampus （P<0.05， P<0.01）， which， however， were recovered in Wenyang， Jieyu， Wenyang Jieyu， and fluoxetine groups （P<0.05， P<0.01）. ConclusionThe mouse model of depression induced by MS+RS may present the syndrome of Yang deficiency and liver depression. Wenyang Jieyu prescription may increase the content of hippocampal neurotransmitters by regulating the 5-HT system and the BDNF signaling pathway mediated by the HPA axis， thereby alleviating depression-like behavior in mice.

ObjectiveTo explore the effects of Wenyang Jieyu prescription （WJP） on neuroinflammation and synaptic plasticity in the mouse model of depression induced by maternal separation combined with restraint stress. MethodThe mice on postnatal day 0 （PD0） were randomized into a control group and a modeling group. Maternal separation combined with restraint stress was employed to establish the mouse model of depression. After the removal of female mice， the modeled mice were randomized into model， Wenyang prescription （5.85 g·kg^-1）， Jieyu prescription （12.03 g·kg^-1）， WJP （16.71 g·kg^-1）， and fluoxetine （2.6 mg·kg^-1） groups on the weaning day （PD21）， with 15 mice in each group. The mice were administrated with corresponding drugs mixed with the diet from PD21 to PD111. The sucrose preference test， open field test， O-maze test， and novel object recognition test were then carried out to evaluate the depression state， memory， and learning ability of the mice. Immunohistochemistry （IHC） was employed to observe the ionized calcium-binding adapter molecule-1 （Iba-1） in hippocampal microglia. High performance liquid chromatography （HPLC） was employed to measure the content of noradrenaline （NE） and epinephrine （E） in the hippocampus. Enzyme-linked immunosorbent assay （ELISA） was employed to determine the content of interleukin （IL）-18 and IL-1β in the hippocampus. Western blot was employed to determine the protein levels of NOD-like receptor protein 3 （NLRP3）， apoptosis-associated speck-like protein containing a CARD （ASC）， cysteine aspartate-specific protease-1 （Caspase-1）， IL-1β， synaptophysin （Syn）， and postsynaptic density 95 （PSD95）. ResultCompared with control group， the model group showed decreased sucrose preference rate， time spent in central zone within 5 min， total movement distance， time spent in the open arm， and cognition index （P<0.05， P<0.01）. The microglia in the model group presented amoeba-like appearance， the Iba1 increased. Moreover， the model group showed decreased content of NE and E （P<0.01）， elevated levels of IL-1β and IL-18 （P<0.01）， down-regulated protein levels of PSD95 and Syn （P<0.05， P<0.01）， and up-regulated protein levels of NLRP3， ASC， Caspase-1， and IL-1β （P<0.05， P<0.01）. Compared with model group， WJP and fluoxetine increased the sucrose preference rate， time spent in central zone within 5 min， total movement distance， time spent in the open arm， and cognition index （P<0.05， P<0.01）. They recovered the microglia and the Iba1 decreased. Moreover， the drugs increased the content of NE and E （P<0.05， P<0.01）， lowered the levels of IL-1β and IL-18 （P<0.01）， up-regulated the protein levels of PSD95 and Syn （P<0.01）， down-regulated the protein levels of NLRP3， ASC， Caspase-1， and IL-1β （P<0.05， P<0.01）. ConclusionWJP can treat the depressive behavior induced by maternal separation combined with restraint stress in mice， with the performance outperforming Wenyang prescription and Jieyu prescription. It may alleviate the neuroinflammation induced by microglia and improve the synaptic plasticity by regulating the NLRP3 pathway and increasing neurotransmitters in the hippocampus.