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.

Objective To explore the spatiotemporal expression patterns of Patched 1(Ptch1)and insulin enhancer binding protein-1(Isl 1)in mouse embryonic foregut and their relationship with the early development of trachea-main bronchus.Methods The foregut of 60 mouse embryos at E9.5-12.5 was separated for the detection of Isl1 and sonic hedgehog(Shh)protein by Western blotting.Serial paraffin sections of 6 mouse embryos at E9.5-14.5 were taken for immunohistochemical staining and immunofluorescence double staining with Isl1,Ptch1,forkhead box protein A2(Foxa2),type Ⅱ collagen α1 chain(Col2a1)and α-smooth muscle actin(α-SMA),as well as HE staining and Masson staining.Results The expression trend of Isl1 and Shh in foregut endoderm at E9.5-12.5 was similar,and the peak of Shh expression was later than Isl1.The foregut developed into the trachea at E9.5-12.5,Ptch1 was expressed in the thickening and protrusion of the respiratory endoderm,the laryngal-tracheal groove and the solid cell cord,accompanied by the increase and aggregation of Isl1-positive mesenchymal cells,forming a characteristic pyramidal structure centered on the respiratory endoderm and the solid cell cord;The main bronchus appeared at E12.5-13.5,Ptch1 was only expressed in its lateral wall,accompanied by the accumulation of Isl1-positive mesenchymal cells;The trachea-main bronchial epithelium lost Ptch1 expression and the surrounding Isl 1-positive mesenchymal cells also decreased rapidly at E13.5-14.5.Co12a1-positive chondrocytes first appeared in the Isl1-positive mesenchymal area adjacent to the Ptch1-positive epithelium at E12.5;Col2a1-positive cartilage was nested within the Isl1-positive mesenchymic area in a"C"shape and expanded in a proximal-distal pattern at E12.5-13.5;Col2a1-positive cartilage extended to the dorsal trachea beyond the Isl1-positive mesenchyma and encircles α-SMA positive smooth muscle in a circular manner at E14.5.Conclusion The expression of Ptch1 in the foregut endoderm is involved in the development and morphogenesis of the trachea-main bronchus epithelium,and is closely related to the proliferation and aggregation of Isl1-positive mesenchyme in the trachea-main bronchial wall,Subsequently,they jointly determine the time,location and extent of airway cartilage.

Background: and Purpose This study aimed to investigate the association between residual inflammatory risk (RIR) and vulnerable plaques using high-resolution magnetic resonance imaging (HRMRI) in symptomatic intracranial atherosclerotic stenosis (ICAS). Methods: This retrospective study included 70%–99% symptomatic ICAS patients hospitalized from January 2016 to December 2022. Patients were classified into four groups based on high-sensitivity C-reactive protein (hs-CRP) and low-density lipoprotein cholesterol (LDL-C): residual cholesterol inflammatory risk (RCIR, hs-CRP ≥3 mg/L and LDL-C ≥2.6 mmol/L), RIR (hs-CRP ≥3 mg/L and LDL-C <2.6 mmol/L), residual cholesterol risk (RCR, hs-CRP <3 mg/L and LDL-C ≥2.6 mmol/L), and no residual risk (NRR, hs-CRP <3 mg/L and LDL-C <2.6 mmol/L). Vulnerable plaque features on HRMRI included positive remodeling, diffuse distribution, intraplaque hemorrhage, and strong enhancement. Results: Among 336 included patients, 21, 60, 58, and 197 were assigned to the RCIR, RIR, RCR, and NRR groups, respectively. Patients with RCIR (adjusted odds ratio [aOR], 3.606; 95% confidence interval [CI], 1.346–9.662; P=0.011) and RIR (aOR, 3.361; 95% CI, 1.774–6.368, P<0.001) had higher risks of strong enhancement than those with NRR. Additionally, patients with RCIR (aOR, 2.965; 95% CI, 1.060–8.297; P=0.038) were more likely to have intraplaque hemorrhage compared with those with NRR. In the sensitivity analysis, RCR (aOR, 2.595; 95% CI, 1.201–5.608; P=0.015) exhibited an additional correlation with an increased risk of intraplaque hemorrhage. Conclusion In patients with symptomatic ICAS, RIR is associated with a higher risk of intraplaque hemorrhage and strong enhancement, indicating an increased vulnerability to atherosclerotic plaques.

AIM: To assess the stability of the tear film and the characteristics of corneal nerves in patients with Parkinson's disease(PD).METHODS: This cross-sectional observational study included 72 PD patients and 50 healthy controls. Disease severity was determined using the Hoehn-Yahr(H-Y)scale, dividing patients into mild and moderate PD groups. Dry eye symptoms were evaluated via the ocular surface disease index(OSDI)questionnaire, while tear secretion was quantified using the Schirmer I test. Ocular surface damage was assessed through staining scores, and comprehensive ocular examinations were performed utilizing the LipiView ocular surface interferometer and an ocular surface analyzer. Corneal nerve parameters were examined using corneal confocal microscopy in conjunction with automated analysis software ACCMetrics, with correlations drawn between these parameters, PD course, and severity.RESULTS: PD patients exhibited significantly elevated OSDI scores, indicative of more pronounced dry eye symptoms compared to the control group(F=70.290, P<0.01). Tear film stability was markedly compromised, with significantly shorter tear film breakup time and increased corneal fluorescein staining, both showing statistically significant differences relative to controls(all P<0.01). Tear secretion indices, including Schirmer I test results and tear meniscus height, were significantly reduced in PD patients(all P<0.01), whereas lipid secretion indices, such as lipid layer thickness and meibomian gland dropout score, did not show significant variation. Corneal nerve analysis revealed significant reductions in corneal nerve fiber density, nerve branch density, fiber length, and total branch density in PD patients compared to controls(all P<0.01). Furthermore, blink frequency was markedly prolonged(F=62.353, P<0.01). Correlation analysis demonstrated a significant relationship between alterations in tear film stability and both disease duration and H-Y scores.CONCLUSION: PD patients have obvious dry eye manifestations in the early stage of the disease, including the reduction of tear film stability and corneal nerve fiber density, and gradually aggravate with the progress of the disease. Neurodegenerative disease-related dry eye needs to be diagnosed early and actively treated.

Background: and Purpose This study aimed to investigate the association between residual inflammatory risk (RIR) and vulnerable plaques using high-resolution magnetic resonance imaging (HRMRI) in symptomatic intracranial atherosclerotic stenosis (ICAS). Methods: This retrospective study included 70%–99% symptomatic ICAS patients hospitalized from January 2016 to December 2022. Patients were classified into four groups based on high-sensitivity C-reactive protein (hs-CRP) and low-density lipoprotein cholesterol (LDL-C): residual cholesterol inflammatory risk (RCIR, hs-CRP ≥3 mg/L and LDL-C ≥2.6 mmol/L), RIR (hs-CRP ≥3 mg/L and LDL-C <2.6 mmol/L), residual cholesterol risk (RCR, hs-CRP <3 mg/L and LDL-C ≥2.6 mmol/L), and no residual risk (NRR, hs-CRP <3 mg/L and LDL-C <2.6 mmol/L). Vulnerable plaque features on HRMRI included positive remodeling, diffuse distribution, intraplaque hemorrhage, and strong enhancement. Results: Among 336 included patients, 21, 60, 58, and 197 were assigned to the RCIR, RIR, RCR, and NRR groups, respectively. Patients with RCIR (adjusted odds ratio [aOR], 3.606; 95% confidence interval [CI], 1.346–9.662; P=0.011) and RIR (aOR, 3.361; 95% CI, 1.774–6.368, P<0.001) had higher risks of strong enhancement than those with NRR. Additionally, patients with RCIR (aOR, 2.965; 95% CI, 1.060–8.297; P=0.038) were more likely to have intraplaque hemorrhage compared with those with NRR. In the sensitivity analysis, RCR (aOR, 2.595; 95% CI, 1.201–5.608; P=0.015) exhibited an additional correlation with an increased risk of intraplaque hemorrhage. Conclusion In patients with symptomatic ICAS, RIR is associated with a higher risk of intraplaque hemorrhage and strong enhancement, indicating an increased vulnerability to atherosclerotic plaques.

Background: and Purpose This study aimed to investigate the association between residual inflammatory risk (RIR) and vulnerable plaques using high-resolution magnetic resonance imaging (HRMRI) in symptomatic intracranial atherosclerotic stenosis (ICAS). Methods: This retrospective study included 70%–99% symptomatic ICAS patients hospitalized from January 2016 to December 2022. Patients were classified into four groups based on high-sensitivity C-reactive protein (hs-CRP) and low-density lipoprotein cholesterol (LDL-C): residual cholesterol inflammatory risk (RCIR, hs-CRP ≥3 mg/L and LDL-C ≥2.6 mmol/L), RIR (hs-CRP ≥3 mg/L and LDL-C <2.6 mmol/L), residual cholesterol risk (RCR, hs-CRP <3 mg/L and LDL-C ≥2.6 mmol/L), and no residual risk (NRR, hs-CRP <3 mg/L and LDL-C <2.6 mmol/L). Vulnerable plaque features on HRMRI included positive remodeling, diffuse distribution, intraplaque hemorrhage, and strong enhancement. Results: Among 336 included patients, 21, 60, 58, and 197 were assigned to the RCIR, RIR, RCR, and NRR groups, respectively. Patients with RCIR (adjusted odds ratio [aOR], 3.606; 95% confidence interval [CI], 1.346–9.662; P=0.011) and RIR (aOR, 3.361; 95% CI, 1.774–6.368, P<0.001) had higher risks of strong enhancement than those with NRR. Additionally, patients with RCIR (aOR, 2.965; 95% CI, 1.060–8.297; P=0.038) were more likely to have intraplaque hemorrhage compared with those with NRR. In the sensitivity analysis, RCR (aOR, 2.595; 95% CI, 1.201–5.608; P=0.015) exhibited an additional correlation with an increased risk of intraplaque hemorrhage. Conclusion In patients with symptomatic ICAS, RIR is associated with a higher risk of intraplaque hemorrhage and strong enhancement, indicating an increased vulnerability to atherosclerotic plaques.

Isoflavones which mainly distributed in leguminous plants have plenty of health benefits.Isoflavone synthase(IFS)is a membrane-associated cytochrome P450 enzyme(CYP450)which carries out the unique aryl-ring migration and hydroxylation.So far,few crystal structures of plant P450s have been obtained.We determined the crystal structure of IFS from Medicago truncatula at 1.9 ? by MAD method using a selenomethionine substituted crystal and conducted molecular docking and mutagenesis study.The structure of IFS complexed with imidazole exhibits the helix Ⅰa-loop-helix Ⅰβ motif which cor-responds to helix Ⅰ of other P450s.Compared with structures of common P450s,IFS/imidazole structure contains an extra domain,i.e.,the γ-domain.The structure reveals a homodimer in which the γ-domain of one molecule interacts with the β-domain of another.The plane of heme group makes an angle of ap-proximately 40° with the helix Ⅰa-loop-helix Ⅰβ motif.Molecular docking combined with mutagenesis study suggested that Trp-128 and Asp-300 might play important roles in substrate binding and recogni-tion.Phe-301,Ser-303 and Gly-305 from the helix Ⅰa-loop-helix Ⅰβ motif may play important roles in the aryl-ring migration.These novel structural features reveal insights into the unique reaction mechanism of IFS and provide a basis for engineering IFS in leguminous crops for health purpose.

Objective:This study aims to construct a monitoring index system for early child development(ECD)that is consistent with China's actual situation,to scientifically and systematically evaluate the level of ECD and service capacity in various regions.Methods:The study was predicated on the theoretical foundation of the Nutrition Care Framework(NCF).Indicators were initially selected through a literature review and focus group interviews.The evaluation indicators were then determined through two rounds of expert consultation utilising the Delphi method.The Priority Sequence Diagram Method(PSDM)was subsequently implemented to determine indicator weights.Results:The final framework encompasses six first-level indicators(good health,adequate nutrition,responsive caregiving,opportunities for learning,security and safety,and demand and investment),12 second-level indicators,and 31 third-level indicators.Conclusion:The ECD index system constructed in this study integrates macro,meso,and micro levels,emphasises cross-sectoral collaboration and attention to child caregivers,and incorporates equity indicators to measure regional disparities.The research outcomes provide a reference for quantitatively assessing the level of ECD and service capacity across various regions in China.By leveraging mechanisms for cross-sectoral collaboration and goal-oriented approaches,the study provides a framework for the allocation of resources to key areas,thus laying the foundation for the sustained implementation and resource assurance of the child-priority development strategy.

This article summarizesd Professor Li Zhigang's experience in treating limb dysfunction after acute disseminated encephalomyelitis(ADEM)by acupuncture.Prof.Li respected the classical theory of Chinese medicine,which is to seek the root cause of the disease,clarified the disease mechanism of"deficiency of Yangming leads to longitudinal tendons and unfavorable belt veins",and followed the principle of"treating flaccidity syndrome only by taking advantage of Yangming",and combined with the morbidity characteristics of ADEM that occurs in children,emphasized the important influence of regulating the root of innate and acquired in the treatment of the disease.The importance of regulating the essence of congenital and acquired constitution in the treatment of this disease was emphasized,taking into account the importance of regulating the mind and spirit.The main acupoints of Yangming Stomach Meridian,Large Intestine Meridian,Spleen Meridian,and Governor Vessel,together with the five main points of the lower limbs and the main points of water-inducing,all together play the role of tonifying the middle energizer,benefiting the essence and filling in the marrow,and strengthening the muscles and bones.

OBJECTIVE: To explore the effect of nano-hydroxyapatite/collagen composite (nHAC) on bone graft fusion after anterior cervical discectomy and fusion (ACDF) in patients with cervical spondylosis and low bone mass. METHODS: A retrospective analysis was conducted on 47 patients with low bone mass who underwent ACDF from 2017 to 2021. They were divided into the nHAC group and the allogeneic bone group according to different bone graft materials. The nHAC group included 26 cases, with 8 males and 18 females;aged 50 to 78 years old with an average of (62.81±7.79) years old;the CT value of C₂-C₇ vertebrae was (264.16±36.33) HU. The allogeneic bone group included 21 cases, with 9 males and 12 females;aged 54 to 75 years old with an average of (65.95±6.58) years old;the CT value of C₂-C₇ vertebrae was (272.39±40.44) HU. The visual analogue scale (VAS), neck disability index (NDI), and Japanese Orthopaedic Association (JOA) spinal cord function score were compared before surgery, 1 week after surgery, and at the last follow-up to evaluate the clinical efficacy. Imaging assessment included C₂-C₇ Cobb angle, surgical segment height, intervertebral fusion, and whether the cage subsidence occurred at 1 week after surgery and the last follow-up. RESULTS: The follow-up duration ranged from 26 to 39 months with an average of (33.27±3.34) months in the nHAC group and 26 to 41 months with an average of (31.86±3.57) months in the allogeneic bone group. At 1 week after surgery and the last follow-up, the VAS, NDI scores, and JOA scores in both groups were significantly improved compared with those before surgery, with statistically significant differences (P<0.05). At 1 week after surgery, the C₂-C₇ Cobb angles in the nHAC group and the allogeneic bone group were (14.26±10.32)° and (14.28±8.20)° respectively, which were significantly different from those before surgery (P<0.05). At the last follow-up, the C₂-C₇ Cobb angles in both groups were smaller than those at 1 week after surgery, with statistically significant differences (P<0.05). At 1 week after surgery, the height of the surgical segment in the nHAC group was (31.65±2.55) mm, and that in the allogeneic bone group was (33.63±3.26) mm, which were significantly different from those before surgery (P<0.05). At the last follow-up, the height of the surgical segment in both groups decreased compared with that at 1 week after surgery, with statistically significant differences (P<0.05). At the last follow-up, 39 surgical segments were fused and 6 cages subsided in the nHAC group;40 surgical segments were fused and 7 cages subsided in the allogeneic bone group;there was no statistically significant difference between the two groups (P>0.05). Compared with the CT value of vertebrae without cage subsidence, the CT value of vertebrae with cage subsidence in both groups was significantly lower, with a statistically significant difference (P<0.05). CONCLUSION The application of nHAC in ACDF for patients with low bone mass can achieve effective fusion of the surgical segment. There is no significant difference in improving clinical efficacy, intervertebral fusion, and cage subsidence compared with the allogeneic bone group. With the extension of follow-up time, the C₂-C₇ Cobb angle decreases, the height of the surgical segment is lost, and the cage subsides in both the nHAC group and the allogeneic bone group, which may be related to low bone mass. Low bone mass may be one of the risk factors for cervical spine sequence changes, surgical segment height loss, and cage subsidence after ACDF.
Humans ; Male ; Female ; Middle Aged ; Spondylosis/physiopathology* ; Spinal Fusion/methods* ; Cervical Vertebrae/surgery* ; Aged ; Diskectomy ; Durapatite ; Retrospective Studies ; Collagen/chemistry*