ABSTRACT: Rhododendron fortune belongs to a scented Rhododendron species native to China, which produces fragrant flowers of great ornamental and environmental values for landscaping or indoor beautification. However, the scents in Rhododendron fortuneihave not yet been investigated, let alone the mechanism of the formation of these fragrance in the flowers. In this study, we measured the scents in terms of its volatile components and contents (VOC) in Rhododendron fortuneiat four different flowering stages and in different tissues of the plant by headspace solid-phase micro-extraction combined (HS-SPME) with gas chromatography-mass spectrometry (GC-MS). Then the characteristic aromatic values, which reflects the degree of scent perception by human, of each VOC in the plant was calculated according to its respective aromatic thresholds. Results showed that three main VOCs measured from highest to lowest are methyl benzoates, terpenes and fatty acid derivatives. Their content increased after the flower bud opening and reached the highest at half to full blossom. In a flower most VOC contents were measured in petals and only trace amount in other tissues such as stamen, pistil. A small amount of VOCs was determined in leaves as well.All aromatic values were almost corresponded to the contents of three main VOCs, indicating that the flower fragrance arises truly from these VOC components. S-adenosyl-L-methionine: benzoic acid carboxyl methyl transferase (BAMT) catalyzes the final step to form methyl benzoates. To understand the mechanism of the formation of this main type fragrance and its regulation, we firstly isolate a gene of RfBAMT from petal of Rhododendron fortuneiby using homologous cloning and RACE technology. The full length of its cDNA was 1383 bp，with an open reading frame of 1104 bp, encoding a total of 368 amino acids. The phylogenetic tree analysis showed that RfBAMT was the closest to the BSMT of Camellia japonica, belonging to methyltransferases family. Then we measured the expression level of RfBAMT again at four flower developmental stages and in different flower tissues and leaves. The results showed that the expression level of this gene was highly positively correlated with the emitted content of methyl benzoates in the flowering, implying that RfBAMT plays a pivotal role in the formation and regulation of methyl benzoates in Rhododendron fortune.Thisresearchshowed that the RfBAMT was cloned and identified in our study and its expression level was highly positively correlated with the emitted content of methyl benzoates in the flowers and leaves, which indicated this gene may play an important role on regulation of methyl benzoate synthesis in Rhododendron fortunei.

RESUMO: Rhododendron fortunei pertence a uma espécie de rododendro perfumada nativa da China, que produz flores perfumadas de grande valor ornamental e ambiental para paisagismo ou embelezamento de interiores. No entanto, os aromas em Rhododendron fortunei ainda não foram investigados, muito menos o mecanismo de formação dessas fragrâncias nas flores. Neste estudo, medimos os aromas em termos de seus componentes e conteúdos voláteis (VOC) em Rhododendron fortunei em quatro diferentes estágios de floração e em diferentes tecidos da planta por microextração em fase sólida headspace combinada com cromatografia gasosa-espectrometria de massa. Em seguida, foram calculados os valores aromáticos característicos, que refletem o grau de percepção olfativa pelo ser humano, de cada VOC na planta de acordo com seus respectivos limiares aromáticos. Os resultados mostraram que três COVs principais medidos do mais alto ao mais baixo são benzoatos de metila, terpenos e derivados de ácidos graxos. Seu conteúdo aumentou após a abertura do botão floral e atingiu o máximo na metade da floração total. Em uma flor, a maioria dos teores de COV foram medidos em pétalas e apenas traços em outros tecidos, como estame, pistilo. Uma pequena quantidade de COVs foi determinada nas folhas também. Todos os valores aromáticos foram quase correspondentes aos teores de três COVs principais, indicando que a fragrância da flor surge verdadeiramente desses componentes de COV. Para entender o mecanismo de formação deste tipo principal de fragrância e sua regulação, primeiramente isolamos um gene de RfBAMT da pétala de Rhododendron fortunei usando clonagem homóloga e tecnologia RACE. O comprimento total de seu cDNA era de 1383 bp, com um quadro de leitura aberto de 1104 bp, codificando um total de 368 aminoácidos. A análise da árvore filogenética mostrou que RfBAMT foi o mais próximo do BSMT de Camellia japonica, pertencente à família das metiltransferases. Em seguida, medimos o nível de expressão de RfBAMT novamente em quatro estágios de desenvolvimento da flor e em diferentes tecidos e folhas de flores. Os resultados mostraram que o nível de expressão deste gene foi altamente correlacionado positivamente com o conteúdo emitido de benzoatos de metila na floração, implicando que RfBAMT desempenha um papel fundamental na formação e regulação de benzoatos de metila em Rhododendron fortune foi clonado e identificado em nosso estudo e seu nível de expressão foi altamente correlacionado positivamente com o conteúdo emitido de benzoatos de metila nas flores e folhas, o que indicou que este gene pode desempenhar um papel importante na regulação da síntese de benzoato de metila em Rhododendron fortunei.

ABSTRACT Objective: The recurrent laryngeal nerve (RLN) may be involved by papillary thyroid carcinoma ≤ 1 centimeter (PTC ≤ 1 cm). Current study investigated the predictive factors of RLN invasion in PTC ≤ 1 cm, the risk factors of disease recurrence in RLN invaded cases and the results of surgical management for RLN invasion. Materials and methods: Data of 374 PTC ≤ 1 cm patients were retrospectively collected. We performed univariate and multivariate analysis to identify predictive factors of RLN invasion and risk factors of disease recurrence. The abilities of factors in predicting RLN invasion were evaluated. Surgical outcomes and recurrence free survival (RFS) of patients were analyzed. Results: A total of 28 patients suffered RLN invasion, among which seven had disease recurrence. Preoperative vocal cord palsy (VCP), gross extrathyroidal extension, larger tumor size and tumor on the dorsal side of thyroid were verified as predictive factors of RLN invasion. RLN involved patients had poorer RFS, but better than those who also had upper-aerodigestive tract invasion. Upper-aerodigestive tract invasion, lateral neck lymph nodes metastasis (LNM) and BRAF V600E mutation were independent risk factors of disease recurrence in RLN invaded cases. Tumor shaving showed better RLN function preservation without increasing recurrent risk. Conclusions: Current study confirmed the rarity of RLN invasion in PTC ≤ 1 cm. Various aggressive features were verified as predictive factors of RLN invasion. Tumor shaving showed superiority in preserving nerve function without increasing recurrent risk. Special attentions should be paid for disease recurrence when RLN invasion accompanied by upper-aerodigestive tract invasion, lateral neck LNM or BRAF V600E mutation.

Abstract Water fennel is vulnerable to a loss in quality during storage. To improve postharvest quality, fresh-cut water fennel was treated with 37.04 mg m-3 ozone for 15 minutes every 5 days, and then stored at 5 °C for 20 days, and the related quality and antioxidant capacity indexes were determined. The results showed that compared with the control group, the ozone-treated water fennel had better sensory quality, color (L*, a*, ΔE, Chroma ) and firmness after 20 days of storage, and the weight loss decreased by 47%, malondialdehyde content decreased by 41%, soluble solids content decreased by 20%.The ozone treatment also effectively inhibited the increase of respiratory rate and phenolic substances during storage of fresh-cut water fennel. Meanwhile, ozone treatment maintained the content of ascorbic acid, inhibited the activity of polyphenol oxidase and induced an increase of peroxidase, catalase, ascorbate peroxidase and superoxide dismutase, but reduced the content of reduced glutathione. Water fennel after ozone treatment maintained the appearance, texture characteristics and high commercial value during storage. Therefore, ozone treatment may be used as an effective preservation technology for postharvest storage and circulation of water fennel.

Abstract Objective: This study aimed to investigate the demographic and clinicopathological characteristics, and survival outcomes of subglottic Squamous Cell Carcinoma (SCC) based on the Surveillance, Epidemiology, and End Results (SEER) database. Methods: Demographic and clinicopathological information, including age, sex, race, tumor size, histologic grade, clinical/TNM stage, tumor invasion extent, Lymph Node Metastasis (LNM) extent, size of metastatic lymph nodes, LNM ratio and treatment data, of 842 subglottic SCC patients diagnosed between 1996 and 2016 were acquired. Kaplan-Meier survival analyses were performed to assess the effects of clinicopathological characteristics, treatment modalities, surgical procedures, and adjuvant therapies on overall survival and cancer-specific survival. Results: Subglottic SCC was more frequent among males aged 60-70 years, with low-grade but locally advanced lesions without local or distant metastases. Age and several primary tumor/LNM related variables were independent risk factors for overall survival and cancer specific survival. Advanced-stage and high-grade disease led to unfavorable prognosis. The most common treatment modality and surgical procedure were surgery plus radiotherapy and total laryngectomy, respectively. Surgery plus radiotherapy provided favorable 5-year survival outcomes, while total laryngectomy had the worst. Surgery plus adjuvant therapy showed better survival outcomes than surgery alone. Conclusion: This study confirmed the rarity of subglottic SCC. Patients with subglottic SCCs suffered poor prognosis especially for those with advanced-stage or high-grade lesions. The prognosis of subglottic SCC remained poor over the years, despite recent progress in cancer therapies. Surgery plus adjuvant therapy improved the survival outcome. Although larynx preservation surgery was beneficial for early-stage disease, total laryngectomy was favored for patients with advanced tumors. Level of evidence: Level 4.

Abstracts In this paper, experiments were conducted to study the effect of weak magnetic fields on the freezing process of deionized water and physiological normal saline. The results show that different magnetic field strengths have different effects on aqueous solutions. Only a certain strength of the magnetic field will have a positive effect on the freezing process of the aqueous solution, and generally speaking, the effect of the magnetic field on the normal saline is better than that of deionized water. When the magnetic field strength is 150G, the magnetic field has a positive effect on the supercooling degree and the supercooling time of the saline. In the beef freezing experiment, it was found that the magnetic field can not only promote the freezing process of beef but also inhibit the freezing process. Whether a fan is added will also affect the freezing effect of the magnetic field on the beef.The magnetic field strength of 40G and 50G has a significant promotion effect on the freezing process of beef, while the magnetic field strength of 100G~150G has a significant inhibitory effect.

Abstract To determine the synergistic anti-inflammatory effects of resveratrol (RES) combined with vitamin E (VE) and its mechanism. Lipopolysaccharide (LPS)-induced RAW264.7 cells were used to determine the effect of resveratrol, vitamin E and their combination on the production of cellular inflammatory mediators, including NO, IL-6, TNF-α, IL-1β, TLR4 and p-NF-κBp65. The synergistic anti-inflammatory effect of the combination was evaluated by ELISA, and the effect of the combination on the TLR4, p-NF-κBp65 and p-IĸBα pathway by Western blot. The results showed that resveratrol combined with vitamin E synergistically inhibited the production of NO, LDH, MPO and inflammatory factors IL-6, TNF-α, IL-1β and TLR4 by LPS-stimulated macrophages, and effectively inhibited the expression of TLR4, p-NF-κBp65 (P<0.01). Resveratrol combined with vitamin E have a synergistic anti-inflammatory effect. They can inhibit the expression of inflammatory mediators and further suppress the activation of TLR4, p-NF-κBp65 and p-IĸBα signaling pathway in LPS-induced RAW264.7 cell, which might provide a new effective way for inflammation treatment.

Abstract Objectives: M1 macrophage polarization and phenotype in Inflammatory Bowel Disease (IBD) are common biological responses. Method: Herein, IBD mice models were constructed and macrophages were derived. Results: It was discovered that microRNA-146b (miR-146b) was downregulated in IBD mice and Lipopolysaccharide (LPS)-induced macrophages. Moreover, the inhibitory role of overexpressed miR-146b in reducing the inflammation level and blocking M1 macrophage polarization was confirmed. Further investigation indicated that Fibrinogen Like 2 (FGL2) acted as the target gene of miR-146b, and FGL2 mediated activation of NLRP3, NF-κB-p65, and p38-MAPK. More importantly, it was validated that miR-146b could ameliorate inflammatory pheno-type and prevent M1 macrophage polarization via inhibiting FGL2 in vitro, and miR-146b overexpression alleviated the intestinal injury of IBD mice in vivo. Conclusions: Overall, it is potential to use miR-146b for the amelioration of IBD. HIGHLIGHTS miR-146b was downregulated in Inflammatory Bowel Disease (IBD) mice and LPS-induced macrophages. Fibrinogen Like 2 (FGL2) was identified as the target gene of miR-146b. miR-146b ameliorated the inflammation and blocked M1 macrophage polarization via inhibiting FGL2. miR-146b ameliorated the symptoms and pathological injury of IBD via inhibiting FGL2.

Abstract To investigate the value of edible horticultural therapy (EHT) for long-term-hospitalized (LTH) female patients who suffered from schizophrenia. 60 female schizophrenic patients hospitalized in our hospital were randomly divided into EHT group and control group, with 30 cases in each group. The EHT group was combined with EHT on the basis of drug treatment, and the control group was only treated with drug treatment. The Brief Psychiatric Rating Scale (BPRS), the Chinese version Scale of Social Functioning for Psychotic Inpatients (SSFPI), and the Life Satisfaction Index A (LSIA) were compared and analyzed between two groups. After 6 weeks of treatment, the SSFPI score of EHT group increased and was significantly higher than that of the control group. After treatment, the LSIA index of EHT group was higher than that of the control group, and the difference between the two groups was statistically significant (P < 0.05). The BPRS index of EHT group was significantly lower than that before treatment, but there was little change in the control group. There was significant difference between the two groups (P < 0.05). EHT maybe valuable for improving clinical symptoms of schizophrenia and recovery of social function. Clinical registration number:researchregistry7590

RESUMO Introdução: O infarto do miocárdio causado por obesidade pode levar a um declínio de mobilidade e na qualidade de uma vida saudável. O treinamento esportivo é benéfico para a manutenção precoce da função física após o infarto do miocárdio. Objetivo: Este estudo trata do efeito de exercícios aeróbicos de caminhada no tratamento de reabilitação de pacientes que sofreram infarto do miocárdio. Métodos: Recrutamos 91 pacientes que sofreram infarto do miocárdio no grupo de exercícios precoce e 90 pacientes no grupo de controle. O grupo de controle recebeu a intervenção de enfermagem de rotina, enquanto o grupo de exercícios precoce recebeu terapia de reabilitação com exercícios precoces. Resultados: A qualidade de vida efetiva do grupo de exercício precoce foi mais alta do que aquela do grupo de controle. Conclusão: A terapia de exercícios físicos usada no infarto agudo do miocárdio pode reduzir incidências cardiovasculares adversas e melhorar a qualidade de vida dos pacientes. Nível de evidência II; estudos terapêuticos – investigação de resultados de tratamento.

ABSTRACT Introduction: Myocardial infarction caused by human obesity can cause a decline in mobility and a decline in the quality of a healthy life. Sports training is beneficial to maintain early physical functions after myocardial infarction. Objective: This article deals with the effect of applying walking aerobic exercise in the rehabilitation treatment of patients with myocardial infarction. Methods: We enrolled 91 patients with myocardial infarction in the early exercise group and 90 patients in the control group. The control group received the routine nursing intervention, and the early exercise group received early physical exercise rehabilitation therapy. Results: The actual quality of life of the early exercise group was higher than that of the control group. The incidence of cardiovascular adverse events was lower than that of the control group. Conclusion: Physical exercise therapy used in acute myocardial infarction can reduce adverse cardiovascular events and improve the quality of life of patients. Level of evidence II; Therapeutic studies - investigation of treatment results.

RESUMEN Introducción: El infarto de miocardio causado por obesidad puede ocasionar una caída de movilidad y de la calidad de una vida saludable. El entrenamiento deportivo es benéfico para la manutención temprana de la función física tras el infarto de miocardio. Objetivo: Este estudio trata del efecto de ejercicios aeróbicos de caminata en el tratamiento de rehabilitación de pacientes que sufrieron infarto de miocardio. Métodos: Reclutamos 91 pacientes que sufrieron infarto de miocardio en el grupo de ejercicios temprano y 90 pacientes en el grupo de control. El grupo de control recibió la intervención de enfermería de rutina, mientras el grupo de ejercicios tempranos recibió terapia de rehabilitación con ejercicios tempranos. Resultados: La calidad de vida efectiva del grupo de ejercicio temprano fue más alta que aquella del grupo de control. Conclusión: La terapia de ejercicios físicos usada en el infarto agudo de miocardio puede reducir incidencias cardiovasculares adversas y mejorar la calidad de vida de los pacientes. Nivel de evidencia II; Estudios terapéuticos – investigación de resultados de tratamiento.

Abstract: Contrary to the traditional economic prediction that prices decrease as more firms enter the market, this paper finds a non-monotonic relationship between the number of firms and prices in online book markets. A substantial decrease in posted prices is observed when the market moves from a monopoly to duopoly. Surprisingly, as the market further expands, posted prices converge to monopoly price rather than competitive price. This is because as the number of sellers increase on the internet, the cost for consumers to obtain accurate information as well as the cost to evaluate products and sellers increase. Thus, the existence of a large number of sellers deter consumer search and lead to more random purchases. With little consumer search, sellers’ returns to undercutting price reduce. Therefore, instead of lowering price when faced with more competitors, sellers increase prices.

SUMMARY INTRODUCTION: Polycystic ovary syndrome (PCOS) is one of the most common endocrine disorders in women of reproductive age with the prevalence from 5% to 15%, and the prevalence of PCOS in adolescents with obesity seems even higher. The weight status is significantly associated with the quality of life in adolescents with PCOS. OBJECTIVE: This review aims to summarize the latest findings of pathogenesis, diagnosis, comorbidity, and management in PCOS adolescents with obesity. METHODS: This is a narrative review of articles published in PubMed from June 2013 to June 2020 Data were searched using the key words of “polycystic ovary syndrome” AND “adolescent” AND “obesity.” RESULTS: Pubertal obesity, particularly central obesity, could have a negative impact on the pathophysiology of PCOS. In adolescents with obesity, a review of medical history and a long-term follow-up for PCOS symptoms are essential to avoid misdiagnosis. There is a link between obesity and comorbidities of PCOS in adolescents. Holistic treatment and concern for related comorbidities should ideally begin as early as possible in obese adolescents once the diagnosis of PCOS is confirmed. CONCLUSION: Adolescents with PCOS and obesity need more attention from physicians and researchers, and the effective interventions in the early stage are critical to improve their life quality.

This study aimed to investigate the effect of WeChat-based education and rehabilitation program (WERP) on anxiety, depression, health-related quality of life (HRQoL), major adverse cardiac/cerebrovascular events (MACCE)-free survival, and loss to follow-up rate in unprotected left main coronary artery disease (ULMCAD) patients after coronary artery bypass grafting (CABG). In this randomized controlled study, 140 ULMCAD patients who underwent CABG were randomly assigned to WERP group (n=70) or control care (CC) group (n=70). During the 12-month intervention period, anxiety and depression (using hospital anxiety and depression scale (HADS)) and HRQoL (using 12-Item Short-Form Health Survey (SF-12)) were assessed longitudinally. During the total 36-month follow-up period (12-month intervention and 24-month non-intervention periods), MACCE and loss to follow-up were recorded. During the intervention period, HADS-anxiety score at month 9 (M9) (P=0.047) and month 12 (M12) (P=0.034), anxiety rate at M12 (P=0.028), and HADS-D score at M12 (P=0.048) were all reduced in WERP group compared with CC group. As for HRQoL, SF-12 physical component summary score at M9 (P=0.020) and M12 (P=0.010) and SF-12 mental component summary score at M9 (P=0.040) and M12 (P=0.028) were all increased in WERP group compared with CC group. During the total follow-up period, WERP group displayed a trend of longer MACCE-free survival than that in CC group but without statistical significance (P=0.195). Additionally, loss to follow-up rate was attenuated in WERP group compared with CC group (P=0.033). WERP serves as an effective approach in optimizing mental health care and promoting life quality in ULMCAD patients after CABG.

RESUMO Introdução: A acupuntura tem sido amplamente utilizada para alívio de dor. No entanto, seus mecanismos são muito pouco conhecidos. Objetivo: Investigar a relação entre o efeito analgésico da eletroacupuntura e a regulação da expressão de adenosina e de substância P. Métodos: Utilizou-se um modelo de dor inflamatória crônica em ratos por injeção única do Adjuvante Completo de Freund e, em seguida, os animais foram tratados com eletroacupuntura diariamente. Foram aplicadas sete sessões bilaterais de eletroacupuntura (ST36 e BL60, 0,5 a 1,5 mA, força inicial de 0,5 mA, aumentada em 0,5 mA a cada 10 minutos, 30 minutos por sessão, uma sessão por dia) em ratos com Adjuvante Completo de Freund, por sete dias. O efeito analgésico da eletroacupuntura foi avaliado pela medida do limiar de retirada da pata em ratos que receberam estimulações mecânica e térmica. Resultados: A estimulação diária com eletroacupuntura aumentou efetivamente o limiar de retirada da pata em ratos com Adjuvante Completo de Freund. A eletroacupuntura aumentou o nível de adenosina na região zusanli. Estudos posteriores mostraram que a eletroacupuntura poderia diminuir os níveis de substância P, receptor de neurocinina-1, fator de necrose tumoral-alpha, interleucina-1β, interleucina-6 e CD68 nos gânglios da raiz dorsal. Curiosamente, a injeção direta de antagonistas do receptor de adenosina A1 ou de substância P, ou a transecção da raiz do nervo dorsal, podem prejudicar significativamente as ações analgésicas induzidas pela eletroacupuntura em ratos com Adjuvante Completo de Freund e reduzir os níveis de substância P, receptor de neurocinina-1, fator de necrose tumoral-alfa, interleucina-1β, interleucina-6 e CD68. Por fim, confirmamos que a injeção direta de um agonista do receptor da adenosina A1 reproduziu os efeitos analgésicos da eletroacupuntura. Conclusão: Nossos resultados indicam a regulação da secreção da substância P mediada pela adenosina. A via mediada pela substância P pode estar envolvida no processo de analgesia por eletroacupuntura em ratos.

ABSTRACT Background: Acupuncture has been widely used for alleviating pain. However, its mechanisms remain largely enigmatic. Objective: In the present study, we focused on whether the analgesic effect of electroacupuncture is related to its regulation on adenosine and substance P expression. Methods: We established chronic inflammatory pain model in rats through a single injection of Complete Freund’s Adjuvant, and then we treated animals using daily electroacupuncture. We applied seven bilateral sessions of electroacupuncture (ST36 and BL60, 0.5 to 1.5 mA, initial strength of 0.5 mA, increased by 0.5 mA every 10 minutes, for 30 minutes per session, one section per day) to Complete Freund’s Adjuvant rats for seven days. The analgesic effect of electroacupuncture was evaluated by measuring paw withdrawal threshold in rats that received mechanical and thermal stimulation. Results: Daily electroacupuncture stimulation effectively increased paw withdrawal threshold in Complete Freund’s Adjuvant rats. Electroacupuncture increased the adenosine level in zusanli. A further study showed that electroacupuncture could decrease substance P, neurokinin-1 receptor, tumor necrosis factor-alpha, interleukin-1β, interleukin-6 and CD68 levels in dorsal root ganglion. Interestingly, direct injection of adenosine A1 or substance P receptor antagonists, or dorsal nerve root transection could significantly impair electroacupuncture induced analgesic actions in Complete Freund’s Adjuvant rats could and reduce the levels of substance P, neurokinin-1 receptor, tumor necrosis factor-alpha, interleukin-1β, interleukin-6 and CD68. Finally, we confirmed that direct injection of adenosine A1 receptor agonist replicated the analgesic effect of electroacupuncture. Conclusion: Our results indicate regulation of adenosine-mediated substance P secretion. Substance P-mediated pathway may be involved in the analgesia process by electroacupuncture in rats.

Abstract Background: Knowledge of plant population structure facilitates conservation, management, and utilization of endangered plants. Research question: What is the current status of the natural populations of Tetracentron sinense in Leigong Mountain Nature Reserve (LMNR) and what future population development trends can be predicted? Studied species: Tetracentron sinense. Study site and period of research: T. sinense populations in LMNR in China in 2018. Methods: The population structure and quantity dynamics of four typical patches were studied using static life tables, survival curves, survival analyses, and time series analyses. Results: The age structures of the T. sinense populations were spindle-shaped, with few seedlings and saplings, and Deevey type II and III survival curves. The mortality rate (q x ) of each patch increased quickly, and then plateaued, finally increasing again. Survival rate (S x ) showed a contrary trend to q x . Trends in cumulative mortality rate (F (i) ), killing power (K x ), mortality density (f (ti) ), and hazard rate (λ (ti) ) with increasing age class were similar: increasing at a younger age, gradually stabilizing in middle age, and then increasing slightly in older age. The number of individuals in these T. sinense populations was predicted to decrease sharply in future, with younger individuals being seriously deficient. The results showed that the natural populations of T. sinense in the LMNR were relatively stable but were in an early stage of decline. Conclusions: The lack of younger individuals might reflect a bottleneck for regeneration of T. sinense populations, leading to a decline in population size.

Resumen Antecedentes: El conocimiento de la estructura poblacional de una planta facilita su conservación, manejo y utilización. Pregunta de investigación: ¿Cuál es el estado actual de las poblaciones naturales de Tetracentron sinense en la Reserva Natural de la Montaña Leigong (LMNR) y qué tendencias futuras de desarrollo de la población se pueden predecir? Especies estudiadas: Tetracentron sinense. Sitio y período de investigación: Poblaciones en LMNR, China, 2018. Métodos: Se usaron tablas de vida estáticas, curvas de supervivencia, análisis de supervivencia y análisis de series de tiempo para el análisis de la estructura poblacional y dinámica de parches. Resultados: Las estructuras de edad de las poblaciones de T. sinense mostraron forma de huso, con pocas plántulas y juveniles. Curvas de supervivencia Deevey tipo II y III. La tasa de mortalidad (q x ) de cada parche aumentó rápidamente, para estabilizarse y finalmente aumentar nuevamente. La tasa de supervivencia (S x ) mostró una tendencia contraria a q x . Las tendencias en las tasas de mortalidad acumulada (F (i) ), mortalidad (K x ), densidad de mortalidad (f (ti) ), y tasa de riesgo (λ (ti) ) fueron similares con el aumento de la clase de edad. Las poblaciones naturales de T. sinense en el LMNR eran relativamente estables, aunque en etapa temprana de disminución. El número de individuos en poblaciones de T. sinense disminuirá drásticamente en el futuro, donde los más jóvenes mostrarán serias deficiencias. Conclusiones: La ausencia de individuos más jóvenes podría reflejar un cuello de botella para la regeneración de las poblaciones de T. sinense, lo que lleva a una disminución en el tamaño de la población.