Objective To investigate the impact of Toxoplasma gondii type I, II and III rhoptry protein 16 (ROP16) on programmed cell death ligand 1 (PD-L1) expression in lung adenocarcinoma cells, and to examine the effects of T. gondii type I ROP16 protein on the relative PD-L1 expression, the relative PD-L1 distribution on the cell membrane surface, and the binding of programmed cell death 1 (PD-1) to PD-L1 in lung adenocarcinoma cells. Methods Lentiviral vectors overexpressing T. gondii type I, II and III ROP16 proteins were generated, and transfected into the human lung adenocarcinoma A549 cell line. A549 cells were used as a blank control group, and A549 cells transfected with an empty lentiviral expression vector were used as a negative control group, while A549 cells transfected with lentiviral vectors overexpressing T. gondii type I, II and III ROP16 proteins served as experimental groups. Stably transfected cells were selected with puromycin and verified using Western blotting, quantitative real-time PCR (RT-qPCR), and immunofluorescence assays. The PD-L1 expression was quantified at translational and transcriptional levels using Western blotting and RT-qPCR assays in A549 cells in the five groups, and the relative PD-L1 distribution was detected on the A549 cell membrane surface using flow cytometry. In addition, the effect of T. gondii type I ROP16 protein on the PD-1/PD-L1 binding was measured in A549 cells using enzyme-linked immunosorbent assay (ELISA). Results The relative ROP16 protein expression was 0, 0, 1.546 ± 0.091, 1.822 ± 0.047 and 2.334 ± 0.089 in the blank control group, negative control group, and the T. gondii type I, II and III ROP16 protein overexpression groups (F = 1 339.00,P < 0.001), and the relative ROP16 mRNA expression was 2.153 ± 0.949, 2.436 ± 1.614, 14.343 ± 0.020, 12.577 ± 0.285 and 15.090 ± 0.420 in the blank control group, negative control group and the T. gondii type I, II and III ROP16 protein overexpression groups, respectively (F = 483.50,P < 0.001). The ROP16 expression was higher in the T. gondii type I, II and III ROP16 protein overexpression groups than in the blank control group at both translational and transcriptional levels (allP values < 0.001). Immunofluorescence assay revealed that T. gondii type I, II and III ROP16 proteins were predominantly localized in A549 cell nuclei. Western blotting showed that the relative PD-L1 protein expression was 0.685 ± 0.109, 0.589 ± 0.114, 1.007 ± 0.117, 0.572 ± 0.151, and 0.426 ± 0.116 in the blank control group, negative control group, and the T. gondii type I, II and III ROP16 protein overexpression groups (F = 9.46,P < 0.05), and RT-qPCR assay quantified that the relative PD-L1 mRNA expression was 1.012 ± 0.190, 1.281 ± 0.465, 1.950 ± 0.175, 0.889 ± 0.251, and 0.230 ± 0.192 in the blank control group, negative control group, and the T. gondii type I, II and III ROP16 protein overexpression groups (F = 14.18,P < 0.05). The PD-L1 expression was higher in the T. gondii type IROP16 protein overexpression group than in the blank control group at both translational and transcriptional levels (both P values < 0.05). Flow cytometry detected that the relative distributions of PD-L1 protein were (10.83 ± 0.60)%, (11.23 ± 0.20)%, and (14.61 ± 0.50)% on the A549 cell membrane surface (F = 28.31, P < 0.05), and the relative distribution of PD-L1 protein was higher in the T. gondii type IROP16 protein overexpression group than in the blank control group and negative control group (both P values < 0.001). ELISA measured significant differences in the absorbance (A) value among the T. gondii type IROP16 protein overexpression group, the blank control group and the negative control group if the concentrations of the recombinant PD-1 protein were 0.04 (F = 10.45, P < 0.05), 0.08 μg/mL (F = 11.68, P < 0.05) and 0.12 μg/mL (F = 52.68, P < 0.05), and the A value was higher in the T. gondii type IROP16 protein overexpression group than in the blank control group and the negative control group (both P values < 0.05), indicating that T. gondii type IROP16 protein promoted the PD-L1/PD-1 binding in A549 cells in a concentration-dose manner. Conclusions T. gondii type IROP16 protein overexpression may up-regulate PD-L1 expression in A549 cells at both transcriptional and translational levels and the relative PD-L1 distribution on the A549 cell membrane surface, and affect the PD-1/PD-L1 binding in a concentration-dependent manner.

Objective To investigate the effects of Toxoplasma gondii type Iand IIrhoptry protein 16 (ROP16) on the polarization and inflammatory response of mouse alveolar macrophages, so as to provide the scientific evidence for unveiling the immunoregulatory mechanisms following T. gondii infection in host cells and the clinical diagnosis and treatment of pulmonary toxoplasmosis. MethodsMouse alveolar macrophages served as blank controls, and mouse alveolar macrophages transfected with the empty lentiviral expression vector served as negative controls, and mouse alveolar macrophages transfected with lentiviral vectors overexpressing T. gondii type I and II ROP16 served as the type I and II ROP16 overexpression groups. Following puromycin selection, stably transfected cells that overexpressed type Iand IIROP16 were generated, observed for green fluorescence expression under a fluorescence microscope and verified using PCR, Western blotting and real-time quantitative reverse transcription PCR (RT-qPCR) assays. The expression of ROP16, inducible nitric oxide synthase (iNOS), arginase (Arg)-1, mannose receptor (CD206), cluster of differentiation 86 (CD86), NOD-like receptor thermal protein domain associated protein 3 (NLRP3), caspase-1, apoptosis-associated speck-like protein containing a CARD (ASC), and interleukin (IL)-1β proteins was determined in mouse alveolar macrophages using Western blotting assay, and the mRNA levels of ROP16, iNOS, IL-1β, IL-4, IL-12, IL-18, Arg-1, IL-10, IL-6, tumor necrosis factor (TNF)-α and transforming growth factor (TGF)-β were detected in mouse alveolar macrophages using RT-qPCR assay. Results Fluorescence microscopy showed 90% of mouse alveolar macrophages producing green fluorescent signals in the type Iand II ROP16 overexpression groups and the negative control group. The relative ROP16 protein expression was 1.000 ± 0.000, 1.003 ± 0.020, 1.349 ± 0.055, and 1.376 ± 0.080 in mouse alveolar macrophages in the blank control group, negative control group, and type Iand IIROP16 overexpression groups (F = 35.30, P < 0.01), and the relative ROP16 mRNA expression was 1.007 ± 0.172, 2.030 ± 0.356, 1 409.579 ± 75.960, and 1 413.581 ± 27.712 in the blank control group, negative control group, and type Iand II ROP16 overexpression groups (F = 811.00, P < 0.01). The ROP16 expression was significantly higher in the type Iand IIROP16 overexpression groups than in the blank control group at both protein and mRNA levels (all P value < 0.01). Western blotting assay detected significant differences among the four groups in terms of iNOS, Arg-1, CD86, CD206, NLRP3, caspase-1, ASC, and IL-1β protein expression (F = 124.70, 82.40, 79.82, 919.40, 84.74, 39.85, 2 354.00 and 65.96, all P values < 0.05), and the expression of Arg-1, CD206, NLRP3, caspase-1, ASC, and IL-1β proteins was significantly higher in the type I ROP16 overexpression group than in the blank control group (all P values < 0.001), while the expression of iNOS, CD86, NLRP3, caspase-1, ASC, and IL-1β proteins was significantly higher in the type II ROP16 overexpression group than in the blank control group (all P values < 0.01). RT-qPCR assay detected significant differences among the four groups in terms of iNOS, IL-1β, IL-4, IL-12, IL-18, Arg-1, IL-10, IL-6, TNF-α, and TGF-β mRNA expression (F = 407.00, 1 528.00, 833.10, 267.90, 989.80, 161.80, 461.10, 5 529.00, 849.60 and 8 836.00, all P values < 0.05), and the Arg-1, IL-4, IL-10, and TGF-β mRNA expression was significantly higher in the type I ROP16 overexpression group than in the blank control group (all P values < 0.001), while the iNOS, IL-1β, IL-12, IL-18, IL-6, and TNF-α mRNA expression was significantly higher in the type II ROP16 overexpression group than in the blank control group (all P values < 0.001). Conclusions T. gondii type IROP16 may induce M2-dominant phenotypes of mouse alveolar macrophages, and type II ROP16 may induce M1-dominant phenotypes of mouse alveolar macrophages. Both T. gondii type I and II ROP16 may activate NLRP3, and mediate the activation of ASC, caspase-1 and IL-1β to promote inflammatory responses.

Objective To explore the efficacy of progressive exercise training based on the modified Medical Research Council dyspnea scale (mMRC) grading in respiratory rehabilitation for patients with chronic obstructive pulmonary disease (COPD) at a primary healthcare setting. Methods A total of 106 patients with COPD admitted to Zhuanqiao Community Health Service Center in Shanghai from Aug.1, 2022 to Jul. 30, 2024 were selected as research subjects. They were randomly divided into a study group and a control group in a 1∶1 ratio, with 53 patients in each group. The control group received conventional treatment, while the study group received conventional treatment combined with progressive exercise training. After 4 weeks of continuous treatment, the changes in the 6-minute walk test (6MWT), COPD assessment test (CAT) score, mMRC grading, Global Initiative for Chronic Obstructive Lung Disease (GOLD) grading and pulmonary function were compared between the two groups. Results Patients in both groups showed improvements in 6MWT distance, CAT score, mMRC grading, GOLD grading, and pulmonary function compared to baseline (P＜0.05). Moreover, the study group had better improvements in 6MWT distance, CAT score, mMRC grading, GOLD grading, and pulmonary function than the control group (P＜0.05). Conclusions Conventional treatment combined with progressive exercise training based on mMRC grading can enhance the effect of respiratory rehabilitation in patients with COPD, particularly in improving pulmonary function and exercise tolerance.

OBJECTIVE: To investigate the role of α7-nicotinic acetylcholine receptor (α7-nAChR) in the regulation of neuronal activity and expression of synapse-related proteins in the thalamic reticular nucleus (TRN) of insomnia rats treated by acupuncture. METHODS: A total of 36 male Sprague-Dawley (SD) rats of clean grade were randomly divided into a control group, a model group, an acupuncture group, and an acupuncture+antagonist group, with 9 rats in each group. The model group, the acupuncture group, and the acupuncture+antagonist group were treated with intraperitoneal injection of p-chlorophenylalanine (PCPA) to establish insomnia model. After successful modeling, the acupuncture group and the acupuncture+antagonist group received acupuncture at bilateral Neiguan (PC6) and Zusanli (ST36) once daily for 5 consecutive days. Thirty min before each acupuncture session, the acupuncture+antagonist group was intraperitoneally injected with methyllycaconitine citrate (MLA), an α7-nAChR antagonist, at a dosage of 5 mg/kg while the acupuncture group received the same volume of 0.9% sodium chloride solution. The rats' daytime spontaneous activity was observed. Neuronal discharge in the TRN was detected using neuroelectrophysiological methods. Immunofluorescence staining was used to detect parvalbumin-positive (PV⁺) neurons and co-expression of PV⁺ and postsynaptic density protein-95 (PSD-95) in the TRN. RESULTS: Compared with the control group, the model group showed increased daytime spontaneous activity (P<0.01); decreased average fluorescence intensity and positive number of PV⁺ neurons in the TRN (P<0.01); decreased neuronal discharge frequency (P<0.01), prolonged inter-discharge intervals (P<0.01) in the TRN; reduced number of PV⁺/PSD-95 double-positive cells in the TRN (P<0.01). Compared with the model group, the acupuncture group showed decreased daytime spontaneous activity (P<0.01); increased average fluorescence intensity and positive number of PV⁺ neurons in the TRN (P<0.01); increased neuronal discharge frequency (P<0.01), shortened inter-discharge intervals (P<0.01) in the TRN; increased number of PV⁺/PSD-95 double-positive cells in the TRN (P<0.05). Compared with the acupuncture group, the acupuncture+antagonist group exhibited increased daytime spontaneous activity (P<0.01); reduced average fluorescence intensity and positive number of PV⁺ neurons in the TRN (P<0.01); decreased neuronal discharge frequency (P<0.05), prolonged inter-discharge intervals (P<0.05) in the TRN; reduced number of PV⁺/PSD-95 double-positive cells in the TRN (P<0.01). CONCLUSION α7-nAChR are involved in mediating the regulatory effect of acupuncture on circadian rhythm disturbances in PCPA-induced insomnia rats. Blocking α7-nAChR attenuates the activating effect of acupuncture on TRN neurons, and reduces the expression of PSD-95 protein on GABAergic neurons.
Animals ; Male ; Acupuncture Therapy ; alpha7 Nicotinic Acetylcholine Receptor/genetics* ; Rats, Sprague-Dawley ; Rats ; Sleep Initiation and Maintenance Disorders/physiopathology* ; Neurons/metabolism* ; Humans ; Thalamic Nuclei/physiopathology* ; Acupuncture Points ; Disks Large Homolog 4 Protein

Pelvic organ prolapse (POP), whose etiology is influenced by genetic and clinical risk factors, considerably impacts women's quality of life. However, the genetic underpinnings in non-European populations and comprehensive risk models integrating genetic and clinical factors remain underexplored. This study constructed the first polygenic risk score (PRS) for POP in the Chinese population by utilizing 20 disease-associated variants from the largest existing genome-wide association study. We analyzed a discovery cohort of 576 cases and 623 controls and a validation cohort of 264 cases and 200 controls. Results showed that the case group exhibited a significantly higher PRS than the control group. Moreover, the odds ratio of the top 10% risk group was 2.6 times higher than that of the bottom 10%. A high PRS was significantly correlated with POP occurrence in women older than 50 years old and in those with one or no childbirths. As far as we know, the integrated prediction model, which combined PRS and clinical risk factors, demonstrated better predictive accuracy than other existing PRS models. This combined risk assessment model serves as a robust tool for POP risk prediction and stratification, thereby offering insights into individualized preventive measures and treatment strategies in future clinical practice.
Humans ; Female ; Pelvic Organ Prolapse/epidemiology* ; Middle Aged ; Risk Assessment/methods* ; China/epidemiology* ; Multifactorial Inheritance ; Aged ; Risk Factors ; Genome-Wide Association Study ; Genetic Predisposition to Disease ; Case-Control Studies ; Adult ; Polymorphism, Single Nucleotide ; Genetic Risk Score ; East Asian People

Objective:To analyze the efficacy of endovascular treatment for venous outflow tract obstruction after liver transplantation.Methods:A retrospective analysis was conducted on the data of 7 patients with venous outflow tract obstruction after liver transplantation admitted to Beijing Friendship Hospital, Capital Medical University from November 2020 to December 2024. Among them, there were 5 males and 2 females, with the age of (22.3±8.1) years. The primary diseases included 2 cases of Budd-Chiari syndrome, 1 case of hepatic veno-occlusive disease, 1 case of portal veno-hepatic sinus vascular disease, 1 case of ornithine carbamoyltransferase deficiency, 1 case of primary biliary cirrhosis, and 1 case of autoimmune cirrhosis. Analyze the patient's clinical manifestations, obstruction of venous outflow tract, hemoglobin levels within one week before and one week after the operation, endovascular treatment conditions, and intraoperative complications such as abdominal hemorrhage and vascular injury. Ultrasound was used to measure the depth of ascites and pleural effusion. All patients were followed up immediately after the operation through phone calls or follow-up visits. The clinical symptoms, abdominal vascular ultrasound, enhanced CT and survival status of the patients were followed up.Results:All 7 patients were diagnosed with venous outflow tract obstruction by intraoperative angiography, including 1 cases of inferior vena cava obstruction, 2 cases of hepatic vein obstruction, and 4 cases of vena cava combined with hepatic vein obstruction. A total of 12 endovascular treatments were performed on 7 patients. Among them, 4 patients received balloon dilation and angioplasty once, 1 patient received balloon dilation and angioplasty twice, 1 patient underwent hepatic vein stent implantation after 2 hepatic vein balloon dilation and angioplasty, and 1 patient underwent intrahepatic portosystemic shunt via jugular vein after 2 hepatic vein balloon dilation and angioplasty. The abdominal distensionof the patients were all relieved after the operation, the ascites and pleural effusion decreased, and the edema symptoms of the lower extremities disappeared. There were no intraoperative complications. The preoperative hemoglobin of 7 patients was (113.4±34.0) g/L, and the postoperative hemoglobin was (126.6±34.8) g/L, which increased significantly compared with that before the operation, and the difference was statistically significant ( t=-0.71, P=0.038). Seven patients were followed up for 6 to 24 months, with a median of 12 months. None of them had obvious symptoms including abdominal distension. Abdominal ultrasound and CT indicated that the blood flow of the transplanted liver was unobstructed, and no patient died. Conclusion:Venous outflow tract obstruction after liver transplantation can cause severe symptoms. Endovascular treatment is an effective treatment for venous outflow tract obstruction after liver transplantation.

This consensus was developed by the Orthodontic Society of the Chinese Stomatological Association to provide a systematic, scientific, and practical guideline for informed consent in orthodontic care. Orthodontic treatment is typically lengthy, highly individualized, and involves multiple factors such as growth and development, occlusal function, and facial esthetics. Rapid technological advances and diverse risk profiles make the traditional reliance on orthodontist experience or institutional templates insufficient to ensure patients′ full understanding and autonomous decision-making. To address this, the expert panel conducted extensive reviews of domestic and international guidelines, analyzed representative dispute cases, and performed multicenter patient-clinician surveys. Using a multi-round Delphi method, the group established a standardized informed consent framework covering the initial consultation, treatment, and retention phases. The consensus emphasizes that informed consent is not only a fundamental legal and ethical requirement but also a key step in building trust, improving patient compliance, and enhancing treatment satisfaction. Orthodontists should clearly and comprehensively explain treatment plans, potential risks, uncertainties, and associated costs, while respecting the autonomy of patients or guardians, and maintain continuous communication and dynamic evaluation throughout the treatment process. The release of this consensus provides unified and authoritative guidance for clinical orthodontics, helping to standardize informed consent, enhance its transparency, safeguard patient rights, reduce medical risks, and promote high-quality, sustainable development of orthodontic practice.

Objective:The clinical symptoms of children with global developmental delay (GDD) were analyzed to provide the scientific basis for the intervention of children with GDD.Methods:The results of the neuro-psychobehavioral scale were collected from 32 511 children with GDD from June 2020 to November 2023. Inclusion criteria: Children diagnosed with GDD according to the Diagnostic and Statistical Manual of Mental Disorders-V, ages 0.0 to 4.9 years. Exclusion criteria: children with common hearing impairment and visual impairment. The Chi-square tests were used for statistical analysis.Results:There were more boys than girls with GDD in outpatient clinics (68.2% vs. 31.8%). Among the children, the proportion of developmental delay in 5, 4, 3, and 2 domains was 31.1%, 23.4%, 22.9% and 22.6% respectively. The rate of delay in 2-3 domains was lower in boys (41.9%) than in girls (53.1%). The rate of delay in 4-5 domains was higher in boys (58.1%) than in girls (46.9%) ( χ2=352.11, P<0.001). Overall, outpatient GDD decreased with age. From 1.0-1.9 to 4.0-4.9 years of age, the proportion of children with developmental delay in 5 domains increased with age (18.2%, 36.4%, 43.9%, 52.4%). Among children aged 0.0-0.9 years, the proportion of 2 domains of developmental delay was higher (33.4%).Among children aged 1.0-1.9 years, the proportion of 2-3 domains of developmental delay was higher (30.7%). Among children aged 2.0-, 3.0-, 4.0-4.9 years, the proportion of developmental delay in 5 domains was higher (36.4%, 43.9%, 52.4%). In children with GDD, the fine motor delay occurred most frequently (85.1%), followed by social self-care (83.9%), language (79.0%), adaptation (62.3%), and gross motor (52.8%). The frequency of developmental delays in fine motor, adaptability, language, and social self-care in boys was higher than that in girls ( χ2=161.37, χ2=41.10, χ2=320.90, χ2=238.54, all P<0.001). The age groups with the highest delay incidence of gross motor, fine motor, adaptability, language, and social self-care were: 4.0-4.9 years (70.6%), 3.0-3.9 years (97.4%), 4.0-4.9 years (81.2%), 2.0-2.9 years (90.9%),2.0-2.9 years (95.4%). The proportions of fine motor delay in GDD children aged 0.0-0.9, 3.0-3.9 and 4.0-4.9 years were (74.5%, 97.4%, 96.8%) and the proportions of social self-care delay in GDD children aged 1.0- and 2.0-2.9 years were (92.1%, 95.4%). Peripheral and mild developmental delays were predominant in children with GDD. The proportion of severe language delay (6.4%) was higher than that in other fields. Conclusions:The proportion of GDD children with developmental delay in 4-5 domains was 54.5%. The most frequent domain of delay was fine motor. The frequencies of developmental delays in fine motor skills, adaptability, language, and social self-care in boys were higher than in girls. Most of the developmental delays in GDD children were marginal and mild. The rate of severe developmental delay in language was higher than in other domains.

Objective:To observe the ultrasonographic features of idiopathic uveal effusion syndrome (IUES).Methods:A retrospective controlled study. From January 2012 to December 2023, 13 patients with IUES (26 eyes) diagnosed by ophthalmology examination in Department of Ophthalmonogy of Beijing Tongren Hospital (IUES group) and 22 healthy people with 30 eyes (control group) were included in the study. Both eyes of all participants were examined by color Doppler ultrasound (CDU) and ultrasonic biomicroscopy (UBM). The thickness of the ocular wall at 300 μm on the temporal side of the optic disc was measured by CDU. UBM was used to measure the thickness of the nasal and temporal scleral processes. Corneal thickness (CT), anterior chamber depth (AD), lens thickness (LT) and axial length (AL) were measured by A-mode ultrasound. There were no significant differences in age ( t=0.842), sex component ratio ( χ2=0.540), eye difference ( χ2=0.108) and AL ( t=0.831) between IUES group and control group ( P>0.05). The CDU and UBM imaging features and biometrics of IUES affected eyes were observed. Independent sample t test was used for comparison between groups. Results:CDU examination results showed that in 26 eyes of IUES group, choroidal detachment occurred in 20 eyes (76.9%, 20/26), which showed arc-shaped band echo connected with peripheral and equatorial eye wall echo, with uniform low echo area below, and blood flow signal could be seen on the band echo. The echo thickened and decreased in 4 eyes (15.3%, 4/26). Nine eyes (33.3%, 9/26) were accompanied by retinal detachment, which showed that the posterior pole vitreous echo was connected to the optic disc echo, and the blood flow signal was seen on the ribbon echo. UBM results showed ciliary detachment in 22 eyes (84.7%, 22/26), showing a spongy thickening of the ciliary body with interlamellar echo separation and an echoless area between the sclera. Ciliary body echo thickened and decreased in 2 eyes (7.7%, 2/26). Shallow space between ciliary body and sclera was observed in 2 eyes (7.7%, 2/26). Compared with the control group, CT ( Z=2.054), LT ( Z=1.867), scleral thickness ( Z=2.536) and ocular wall thickness ( Z=2.094) were thickened in IUES group, and AD ( Z=1.888) were decreased, with statistical significance ( P<0.05). Conclusions:The CDU of IUES is characterized by a thickened echo of the ocular wall and a uniform low echo area under the detached choroid. UBM is characterized by a spongy thickening of the ciliary body echo with interlaminar echo separation.

BACKGROUND:Cervical spondylosis is a chronic degenerative disease that has become one of the most common and frequent diseases threatening human health.At present,the initial diagnosis of the cervical spine and its surrounding structures mainly relies on the interpretation of medical images by radiologists,which not only requires a high level of technical requirements for operators,but also has the disadvantages of strong subjectivity,high labor intensity,and low efficiency.With the rapid development of artificial intelligence technology,its powerful data processing and image recognition capabilities have shown broad application prospects in the medical field.Deep learning has also made certain progress in the research of spinal diseases.OBJECTIVE:To summarize the current status and research progress in the application of artificial intelligence technology in cervical spine imaging images in recent years,evaluating the performance of artificial intelligence models as well as future trends and challenges to be overcome.METHODS:The first author searched the relevant articles in WanFang,CNKI,and PubMed in June 2024.The Chinese search terms were"artificial intelligence,deep learning,cervical spine."English serach terms were"artificial intelligence,Al,cervical vertebrae,cervical."Finally,101 articles were included and analyzed.RESULTS AND CONCLUSION:(1)Artificial intelligence technology can realize automatic segmentation of cervical vertebrae and measurement of curvature change by segmentation,classification,landmarks recognition of medical image parts,detect cervical vertebral fracture,nerve root,and spinal cord type cervical spondylosis,identify cervical spine ossification of posterior longitudinal ligament,and predict post-surgery related risk factors and cervical vertebra maturation classification.(2)Although artificial intelligence technology has shown great potential in the field of cervical spine research,it is still in the early stages of exploration and rapid development,with unlimited room for development and innovation.