T7 RNA polymerase (T7 RNAP) is one of the simplest known RNA polymerases. Its unique structural features make it a critical model for studying the mechanisms of RNA synthesis. This review systematically examines the static crystal structure of T7 RNAP, beginning with an in-depth examination of its characteristic “thumb”, “palm”, and “finger” domains, which form the classic “right-hand-like” architecture. By detailing these structural elements, this review establishes a foundation for understanding the overall organization of T7 RNAP. This review systematically maps the functional roles of secondary structural elements and their subdomains in transcriptional catalysis, progressively elucidating the fundamental relationships between structure and function. Further, the intrinsic flexibility of T7 RNAP and its applications in research are also discussed. Additionally, the review presents the structural diagrams of the enzyme at different stages of the transcription process, and through these diagrams, it provides a detailed description of the complete transcription process of T7 RNAP. By integrating structural dynamics and kinetics analyses, the review constructs a comprehensive framework that bridges static structure to dynamic processes. Despite its advantages, T7 RNAP has a notable limitation: it generates double-stranded RNA (dsRNA) as a byproduct. The presence of dsRNA not only compromises the purity of mRNA products but also elicits nonspecific immune responses, which pose significant challenges for biotechnological and therapeutic applications. The review provides a detailed exploration of the mechanisms underlying dsRNA formation during T7 RNAP catalysis, reviews current strategies to mitigate this issue, and highlights recent progress in the field. A key focus is the semi-rational design of T7 RNAP mutants engineered to minimize dsRNA generation and enhance catalytic performance. Beyond its role in transcription, T7 RNAP exhibits rapid development and extensive application in fields, including gene editing, biosensing, and mRNA vaccines. This review systematically examines the structure-function relationships of T7 RNAP, elucidates the mechanisms of dsRNA formation, and discusses engineering strategies to optimize its performance. It further explores the engineering optimization and functional expansion of T7 RNAP. Furthermore, this review also addresses the pressing issues that currently need resolution, discusses the major challenges in the practical application of T7 RNAP, and provides an outlook on potential future research directions. In summary, this review provides a comprehensive analysis of T7 RNAP, ranging from its structural architecture to cutting-edge applications. We systematically examine: (1) the characteristic right-hand domains (thumb, palm, fingers) that define its minimalistic structure; (2) the structure-function relationships underlying transcriptional catalysis; and (3) the dynamic transitions during the complete transcription cycle. While highlighting T7 RNAP’s versatility in gene editing, biosensing, and mRNA vaccine production, we critically address its major limitation—dsRNA byproduct formation—and evaluate engineering solutions including semi-rationally designed mutants. By synthesizing current knowledge and identifying key challenges, this work aims to provide novel insights for the development and application of T7 RNAP and to foster further thought and progress in related fields.

ObjectiveTo investigate the mechanism by which 2，3，5，4'-tetrahydroxyldiphenylethylene-2-O-glucoside （THSG） mitigates cerebral ischemia/reperfusion （CI/R） injury by regulating mitochondrial calcium overload and promoting mitophagy. MethodsSixty male SD rats were randomized into sham， model， SAS （40 mg·kg^-1）， and low-， medium- and high-dose （10， 20， 40 mg·kg^-1， respectively） THSG groups， with 10 rats in each group. The middle cerebral artery occlusion/reperfusion （MCAO/R） model was established by the modified Longa suture method. An oxygen-glucose deprivation/reoxygenation （OGD/R） model was constructed in PC12 cells. Neurological deficits were assessed via Zea Longa scoring， and cerebral infarct volume was measured by 2，3，5-triphenyltetrazolium chloride （TTC） staining. Structural and functional changes of cortical neurons in MCAO/R rats were assessed by hematoxylin-eosin and Nissl staining. PC12 cell viability was detected by cell counting kit-8 （CCK-8） assay， and mitochondrial calcium levels were quantified by Rhod-2 AM. Immunofluorescence was used to detect co-localization of PTEN-induced kinase 1 （PINK1） and leucine zipper/EF-hand-containing transmembrane protein 1 （LETM1） in neurons. Transmission electron microscopy （TEM） was employed to observe mitochondrial morphology in neurons. Western blot was employed to analyze the expression of translocase of outer mitochondrial membrane 20 （TOMM20）， autophagy-associated protein p62， microtubule-associated protein light chain 3 （LC3）， cysteinyl aspartate-specific proteinase-9 （Caspase-9）， B-cell lymphoma 2-associated protein X （Bax）， and cytochrome C （Cyt C）. ResultsCompared with the sham group， the model group exhibited increased infarct volume （P<0.01） and neurological deficit scores （P<0.01）， neuronal structure was disrupted with reduced Nissl bodies. （P<0.01）， mitochondrial swelling/fragmentation， decreased PINK1/LETM1 co-localization （P<0.01）， upregulated protein levels of LC3Ⅱ/LC3Ⅰ， TOMM20， Caspase-9， Bax， and Cyt C （P<0.01）， downregulated protein level of p62 （P<0.05）， weakened PC12 viability （P<0.01）， and elevated mitochondrial calcium level （P<0.01）. Compared with the model group， THSG and SAS groups showed reduced infarct volumes （P<0.05，P<0.01） and neurological deficit scores （P<0.05，P<0.01）， mitigated mitochondrial damage， and increased PINK1/LETM1 co-localization （P<0.01）. Medium/high-dose THSG and SAS alleviated the neurological damage， increased Nissl bodies （P<0.05，P<0.01）， downregulated the protein levels of p62， TOMM20， Caspase-9， Bax， and Cyt C （P<0.05，P<0.01）， and elevated the LC3Ⅱ/LC3Ⅰ level （P<0.05，P<0.01）. High-dose THSG enhanced PC12 cell viability （P<0.01）， increased PINK1/LETM1 co-localization （P<0.01）， and reduced mitochondrial calcium （P<0.01）. ConclusionTHSG may exert the neuroprotective effect on CI/R injury by activating the PINK1-LETM1 signaling pathway， reducing the mitochondrial calcium overload， and promoting mitophagy.

ObjectiveTo investigate the mechanism by which 2，3，5，4'-tetrahydroxyldiphenylethylene-2-O-glucoside （THSG） mitigates cerebral ischemia/reperfusion （CI/R） injury by regulating mitochondrial calcium overload and promoting mitophagy. MethodsSixty male SD rats were randomized into sham， model， SAS （40 mg·kg^-1）， and low-， medium- and high-dose （10， 20， 40 mg·kg^-1， respectively） THSG groups， with 10 rats in each group. The middle cerebral artery occlusion/reperfusion （MCAO/R） model was established by the modified Longa suture method. An oxygen-glucose deprivation/reoxygenation （OGD/R） model was constructed in PC12 cells. Neurological deficits were assessed via Zea Longa scoring， and cerebral infarct volume was measured by 2，3，5-triphenyltetrazolium chloride （TTC） staining. Structural and functional changes of cortical neurons in MCAO/R rats were assessed by hematoxylin-eosin and Nissl staining. PC12 cell viability was detected by cell counting kit-8 （CCK-8） assay， and mitochondrial calcium levels were quantified by Rhod-2 AM. Immunofluorescence was used to detect co-localization of PTEN-induced kinase 1 （PINK1） and leucine zipper/EF-hand-containing transmembrane protein 1 （LETM1） in neurons. Transmission electron microscopy （TEM） was employed to observe mitochondrial morphology in neurons. Western blot was employed to analyze the expression of translocase of outer mitochondrial membrane 20 （TOMM20）， autophagy-associated protein p62， microtubule-associated protein light chain 3 （LC3）， cysteinyl aspartate-specific proteinase-9 （Caspase-9）， B-cell lymphoma 2-associated protein X （Bax）， and cytochrome C （Cyt C）. ResultsCompared with the sham group， the model group exhibited increased infarct volume （P<0.01） and neurological deficit scores （P<0.01）， neuronal structure was disrupted with reduced Nissl bodies. （P<0.01）， mitochondrial swelling/fragmentation， decreased PINK1/LETM1 co-localization （P<0.01）， upregulated protein levels of LC3Ⅱ/LC3Ⅰ， TOMM20， Caspase-9， Bax， and Cyt C （P<0.01）， downregulated protein level of p62 （P<0.05）， weakened PC12 viability （P<0.01）， and elevated mitochondrial calcium level （P<0.01）. Compared with the model group， THSG and SAS groups showed reduced infarct volumes （P<0.05，P<0.01） and neurological deficit scores （P<0.05，P<0.01）， mitigated mitochondrial damage， and increased PINK1/LETM1 co-localization （P<0.01）. Medium/high-dose THSG and SAS alleviated the neurological damage， increased Nissl bodies （P<0.05，P<0.01）， downregulated the protein levels of p62， TOMM20， Caspase-9， Bax， and Cyt C （P<0.05，P<0.01）， and elevated the LC3Ⅱ/LC3Ⅰ level （P<0.05，P<0.01）. High-dose THSG enhanced PC12 cell viability （P<0.01）， increased PINK1/LETM1 co-localization （P<0.01）， and reduced mitochondrial calcium （P<0.01）. ConclusionTHSG may exert the neuroprotective effect on CI/R injury by activating the PINK1-LETM1 signaling pathway， reducing the mitochondrial calcium overload， and promoting mitophagy.

Purpose: This study aimed to evaluate the contrast-enhanced ultrasound with Sonazoid (Sonazoid-CEUS) features of hepatocellular carcinoma (HCC) in patients with non-alcoholic fatty liver disease (NAFLD). Methods: In this retrospective study, patients who underwent surgical resection and were histopathologically diagnosed with NAFLD or cirrhosis-related HCC were included. All patients received Sonazoid-CEUS examinations within 1 week prior to hepatic surgery. The enhancement patterns of HCC lesions were evaluated and compared between the two groups according to the current World Federation for Ultrasound in Medicine and Biology guidelines. Multivariate logistic regression analysis was used to assess the correlations between Sonazoid-CEUS enhancement patterns and clinicopathologic characteristics. Results: From March 2022 to April 2023, a total of 151 patients with HCC were included, comprising 72 with NAFLD-related HCC and 79 with hepatitis B virus (HBV) cirrhosis–related HCC. On Sonazoid-CEUS, more than half of the NAFLD-related HCCs exhibited relatively early and mild washout within 60 seconds (54.2%, 39/72), whereas most HBV cirrhosis–related HCCs displayed washout between 60 and 120 seconds (46.8%, 37/79) or after 120 seconds (39.2%, 31/79) (P<0.001). In the patients with NAFLD-related HCC, multivariate analysis revealed that international normalized ratio (odds ratio [OR], 0.002; 95% confidence interval [CI], 0.000 to 0.899; P=0.046) and poor tumor differentiation (OR, 21.930; 95% CI, 1.960 to 245.319; P=0.012) were significantly associated with washout occurring within 60 seconds. Conclusion Characteristic Sonazoid-CEUS features are useful for diagnosing HCC in patients with NAFLD.

Purpose: This study aimed to evaluate the contrast-enhanced ultrasound with Sonazoid (Sonazoid-CEUS) features of hepatocellular carcinoma (HCC) in patients with non-alcoholic fatty liver disease (NAFLD). Methods: In this retrospective study, patients who underwent surgical resection and were histopathologically diagnosed with NAFLD or cirrhosis-related HCC were included. All patients received Sonazoid-CEUS examinations within 1 week prior to hepatic surgery. The enhancement patterns of HCC lesions were evaluated and compared between the two groups according to the current World Federation for Ultrasound in Medicine and Biology guidelines. Multivariate logistic regression analysis was used to assess the correlations between Sonazoid-CEUS enhancement patterns and clinicopathologic characteristics. Results: From March 2022 to April 2023, a total of 151 patients with HCC were included, comprising 72 with NAFLD-related HCC and 79 with hepatitis B virus (HBV) cirrhosis–related HCC. On Sonazoid-CEUS, more than half of the NAFLD-related HCCs exhibited relatively early and mild washout within 60 seconds (54.2%, 39/72), whereas most HBV cirrhosis–related HCCs displayed washout between 60 and 120 seconds (46.8%, 37/79) or after 120 seconds (39.2%, 31/79) (P<0.001). In the patients with NAFLD-related HCC, multivariate analysis revealed that international normalized ratio (odds ratio [OR], 0.002; 95% confidence interval [CI], 0.000 to 0.899; P=0.046) and poor tumor differentiation (OR, 21.930; 95% CI, 1.960 to 245.319; P=0.012) were significantly associated with washout occurring within 60 seconds. Conclusion Characteristic Sonazoid-CEUS features are useful for diagnosing HCC in patients with NAFLD.

Purpose: This study aimed to evaluate the contrast-enhanced ultrasound with Sonazoid (Sonazoid-CEUS) features of hepatocellular carcinoma (HCC) in patients with non-alcoholic fatty liver disease (NAFLD). Methods: In this retrospective study, patients who underwent surgical resection and were histopathologically diagnosed with NAFLD or cirrhosis-related HCC were included. All patients received Sonazoid-CEUS examinations within 1 week prior to hepatic surgery. The enhancement patterns of HCC lesions were evaluated and compared between the two groups according to the current World Federation for Ultrasound in Medicine and Biology guidelines. Multivariate logistic regression analysis was used to assess the correlations between Sonazoid-CEUS enhancement patterns and clinicopathologic characteristics. Results: From March 2022 to April 2023, a total of 151 patients with HCC were included, comprising 72 with NAFLD-related HCC and 79 with hepatitis B virus (HBV) cirrhosis–related HCC. On Sonazoid-CEUS, more than half of the NAFLD-related HCCs exhibited relatively early and mild washout within 60 seconds (54.2%, 39/72), whereas most HBV cirrhosis–related HCCs displayed washout between 60 and 120 seconds (46.8%, 37/79) or after 120 seconds (39.2%, 31/79) (P<0.001). In the patients with NAFLD-related HCC, multivariate analysis revealed that international normalized ratio (odds ratio [OR], 0.002; 95% confidence interval [CI], 0.000 to 0.899; P=0.046) and poor tumor differentiation (OR, 21.930; 95% CI, 1.960 to 245.319; P=0.012) were significantly associated with washout occurring within 60 seconds. Conclusion Characteristic Sonazoid-CEUS features are useful for diagnosing HCC in patients with NAFLD.

Purpose: This study aimed to evaluate the contrast-enhanced ultrasound with Sonazoid (Sonazoid-CEUS) features of hepatocellular carcinoma (HCC) in patients with non-alcoholic fatty liver disease (NAFLD). Methods: In this retrospective study, patients who underwent surgical resection and were histopathologically diagnosed with NAFLD or cirrhosis-related HCC were included. All patients received Sonazoid-CEUS examinations within 1 week prior to hepatic surgery. The enhancement patterns of HCC lesions were evaluated and compared between the two groups according to the current World Federation for Ultrasound in Medicine and Biology guidelines. Multivariate logistic regression analysis was used to assess the correlations between Sonazoid-CEUS enhancement patterns and clinicopathologic characteristics. Results: From March 2022 to April 2023, a total of 151 patients with HCC were included, comprising 72 with NAFLD-related HCC and 79 with hepatitis B virus (HBV) cirrhosis–related HCC. On Sonazoid-CEUS, more than half of the NAFLD-related HCCs exhibited relatively early and mild washout within 60 seconds (54.2%, 39/72), whereas most HBV cirrhosis–related HCCs displayed washout between 60 and 120 seconds (46.8%, 37/79) or after 120 seconds (39.2%, 31/79) (P<0.001). In the patients with NAFLD-related HCC, multivariate analysis revealed that international normalized ratio (odds ratio [OR], 0.002; 95% confidence interval [CI], 0.000 to 0.899; P=0.046) and poor tumor differentiation (OR, 21.930; 95% CI, 1.960 to 245.319; P=0.012) were significantly associated with washout occurring within 60 seconds. Conclusion Characteristic Sonazoid-CEUS features are useful for diagnosing HCC in patients with NAFLD.

Purpose: This study aimed to evaluate the contrast-enhanced ultrasound with Sonazoid (Sonazoid-CEUS) features of hepatocellular carcinoma (HCC) in patients with non-alcoholic fatty liver disease (NAFLD). Methods: In this retrospective study, patients who underwent surgical resection and were histopathologically diagnosed with NAFLD or cirrhosis-related HCC were included. All patients received Sonazoid-CEUS examinations within 1 week prior to hepatic surgery. The enhancement patterns of HCC lesions were evaluated and compared between the two groups according to the current World Federation for Ultrasound in Medicine and Biology guidelines. Multivariate logistic regression analysis was used to assess the correlations between Sonazoid-CEUS enhancement patterns and clinicopathologic characteristics. Results: From March 2022 to April 2023, a total of 151 patients with HCC were included, comprising 72 with NAFLD-related HCC and 79 with hepatitis B virus (HBV) cirrhosis–related HCC. On Sonazoid-CEUS, more than half of the NAFLD-related HCCs exhibited relatively early and mild washout within 60 seconds (54.2%, 39/72), whereas most HBV cirrhosis–related HCCs displayed washout between 60 and 120 seconds (46.8%, 37/79) or after 120 seconds (39.2%, 31/79) (P<0.001). In the patients with NAFLD-related HCC, multivariate analysis revealed that international normalized ratio (odds ratio [OR], 0.002; 95% confidence interval [CI], 0.000 to 0.899; P=0.046) and poor tumor differentiation (OR, 21.930; 95% CI, 1.960 to 245.319; P=0.012) were significantly associated with washout occurring within 60 seconds. Conclusion Characteristic Sonazoid-CEUS features are useful for diagnosing HCC in patients with NAFLD.

OBJECTIVE: To explore the mechanism of electroacupuncture (EA) in promoting recovery of the facial function with the involvement of autophagy, glial cell line-derived neurotrophic factor (GDNF), and phosphatidylinositol-3-kinase (PI3K)/mammalian target of rapamycin (mTOR) signaling pathway. METHODS: Seventy-two male Sprague-Dawley rats were randomly allocated into the control, sham-operated, facial nerve injury (FNI), EA, EA+3-methyladenine (3-MA), and EA+GDNF antagonist groups using a random number table, with 12 rats in each group. An FNI rat model was established with facial nerve crushing method. EA intervention was conducted at Dicang (ST 4), Jiache (ST 6), Yifeng (SJ 17), and Hegu (LI 4) acupoints for 2 weeks. The Simone's 10-Point Scale was utilized to monitor the recovery of facial function. The histopathological evaluation of facial nerves was performed using hematoxylin-eosin (HE) staining. The levels of Beclin-1, light chain 3 (LC3), and P62 were detected by immunohistochemistry (IHC), immunofluorescence, and reverse transcription-polymerase chain reaction, respectively. Additionally, IHC was also used to detect the levels of GDNF, Rai, PI3K, and mTOR. RESULTS: The facial functional scores were significantly increased in the EA group than the FNI group (P<0.05 or P<0.01). HE staining showed nerve axons and myelin sheaths, which were destroyed immediately after the injury, were recovered with EA treatment. The expressions of Beclin-1 and LC3 were significantly elevated and the expression of P62 was markedly reduced in FNI rats (P<0.01); however, EA treatment reversed these abnormal changes (P<0.01). Meanwhile, EA stimulation significantly increased the levels of GDNF, Rai, PI3K, and mTOR (P<0.01). After exogenous administration with autophagy inhibitor 3-MA or GDNF antagonist, the repair effect of EA on facial function was attenuated (P<0.05 or P<0.01). CONCLUSIONS EA could promote the recovery of facial function and repair the facial nerve damages in a rat model of FNI. EA may exert this neuroreparative effect through mediating the release of GDNF, activating the PI3K/mTOR signaling pathway, and further regulating the autophagy of facial nerves.
Rats ; Male ; Animals ; Rats, Sprague-Dawley ; Electroacupuncture ; Phosphatidylinositol 3-Kinase/metabolism* ; Facial Nerve Injuries/therapy* ; Phosphatidylinositol 3-Kinases/metabolism* ; Beclin-1 ; Glial Cell Line-Derived Neurotrophic Factor ; Signal Transduction ; TOR Serine-Threonine Kinases/metabolism* ; Autophagy ; Mammals/metabolism*

Nowadays,with the continuous deepening and development of vocational education teaching reform,medical higher vocational education always takes moral education as the fundamental task.As an independent type of education,vocational education should always deepen the integration of industry and education and the integration of science and education.Through the teaching research of"problem chain+course ideological and political case",this study innovates the coordinated education team of drug nursing curriculum,the collaborative education method and the collaborative education evaluation,and improves the teaching effect.