Response of resin canal area of Pinus tabuliformis with different ages to climate change in Taiyue Mountains, China.

To investigate the responses of resin canal area of Pinus tabuliformis with different ages to climate change, we analyzed the relationship between the resin canal area and climate factors from 1972 to 2017 in P. tabuliformis plantation at young age, middle age, near-mature, mature, and over-mature periods in Taiyue Mountains, Shanxi Province. The results showed that 55.7% to 75.2% of resin canal occurred in earlywood. The mature and over-mature periods had the largest resin channel area, sequentially followed by near mature, middle age, and young age periods. Annual mean latewood resin canal area increased significantly in near-mature period and mature period, but not in other periods. There was a significant negative correlation between earlywood resin canal area and minimum temperature during the growing season (May to July) for trees at middle age period. Earlywood resin canal area of mature trees showed significant negative correlation with minimum temperature during the growing season, but significant positive correlation with drought (PDSI) in the non-growing season (previous September to current April). The total area of earlywood resin canal at the young, near-mature, and mature periods was less influenced by climate than other periods. The minimum growing season temperature was a limiting factor to earlywood resin canal growth, while the non-growing season drought gradually became a limiting factor for earlywood resin canal with increasing tree age. The total area of earlywood resin canal decreased with increasing non-growing season drought and increasing growing season minimum temperature. In the context of global warming, the earlywood resin canal area may gradually decrease at all five periods, and the most reduction in the over-mature stage.

Differences in ecological resilience of radial growth between Larix principis-rupprechtii and Picea meyeri after drought.

To understand the responses of radial growth to climatic factors and the differences in ecological resilience to drought between a heliophilous species Larix principis-rupprechtii and a shade species Picea meyeri in mixed forests, we developed the tree-ring width chronologies of L. principis-rupprechtii and P. meyeri in three mixed forests based on the samples collected from Toudaogou of Saihanba in Hebei, Ningwu County and Kelan County in Shanxi Province. We analyzed the correlation between climatic factors and various chronologies and examined the differences in resistance (Rc), recovery (Rt), and resilience (Rs) of L. principis-rupprechtii and P. meyeri in response to drought stress. The results showed that the radial growth of L. principis-rupprechtii and P. meyeri was negatively correlated with the mean and maximum air temperature from May to July in three mixed forests, and was positively correlated with the Palmer drought index (PDSI) from May to September. Radial growth decline in trees due to drought stress was significantly different between the two species among the three sites, indicating different physiological and ecological regulation strategies. The resistance of P. meyeri was stronger than that of L. principis-rupprechtii at the three study sites, with stronger resilience and resilient elasticity of L. principis-rupprechtii than P. meyeri. As a result, P. meyeri exhibited greater drought resistance than L. principis-rupprechtii. Under global warming condition, L. principis-rupprechtii might be at greater risk of growth decline than P. meyeri in this region.

Sex-specific differences in biomechanics among runners: A systematic review with meta-analysis.

Patellofemoral disorders are more common in female runners compared to their male counterparts. Differences in biomechanical characteristics between groups of runners could provide insight into the causes of higher rates of injury in female versus male runners, which would be useful to physical therapists and athletic trainers in development of individualized injury prevention programs. This review compares the differences in biomechanical characteristics between female and male runners. Electronic databases, including PubMed, Scopus, Web of Science, and Embase were searched in December 2021 for studies evaluating sex-specific differences in lower limb mechanics of healthy participants during running. Two independent reviewers determined the inclusion and quality of each research paper. Meta-analyses were used where possible. A total of 13 studies were selected. Means and standard deviations of reported data were retrieved from each selected paper for comparison of results. Three biomechanical variables, including dynamics, muscle activation, and kinematics, were compared between female and male runners. However, no differences were found in kinetic variables or muscle activation between groups due to insufficient data available from the selected studies. Meta-analyses of kinematic variables revealed that female runners exhibited significantly greater hip flexion angle, hip adduction angle, and hip internal rotation angle, but smaller knee flexion angle compared to male runners during running. We found significant differences in kinematic variables between female and male runners, which could influence the training advice of physical therapists and athletic trainers who work with runners, and inform the development of injury prevention programs.

[Expression of cyclins in hepatocellular carcinoma and its correlation to tumor cell apoptosis].

BACKGROUND & OBJECTIVE: Cyclins overexpress in various tumors, but its expression in hepatocellular carcinoma (HCC) and its correlation to cell proliferation and apoptosis are unclear. This study was to determine the expression of Cyclins, proliferating cell nuclear antigen (PCNA), and cell apoptosis in HCC, and to analyze their interrelations. METHODS: Tissue microarray technology and SP immunohistochemistry were used to detect expressions of Cyclins A, B1, D1, E, and PCNA in 122 specimens of HCC. In situ terminal deoxyribonucleotide transferase labeling was used to detect cell apoptosis. RESULTS: In the 122 HCC specimens, positive rate of Cyclin A was 50.0%, of Cyclin B1 was 47.5%, of Cyclin D1 was 42.6%, of Cyclin E was 35.2%. Cyclins levels were significantly higher in HCC tissues of grade II, III, and IV than in HCC tissues of grade I(P 0.05). Densities of apoptotic cells were significantly lower in HCC tissues of grade II, III, and IV than in HCC tissues of grade I(P 0.05); PCNA scores were significantly higher in HCC tissues of grade II, III, and IV than in HCC tissues of grade I(P 0.01). The poorer differentiation, the lower density of apoptotic cells in HCC, the higher PCNA score in HCC. Cyclins levels were negatively related to density of apoptotic cells (r=-0.686, P < 0.01), and positively related to PCNA score (r=0.599, P < 0.01); density of apoptotic cells was negatively related to PCNA score (r=-0.701, P < 0.01). CONCLUSION: Cyclins overexpress in HCC, which may shorten tumor cell cycle phase, accelerate cell proliferation and decrease apoptosis, and result in increased malignant phenotypes.

Significance and relationship between infiltrating inflammatory cell and tumor angiogenesis in hepatocellular carcinoma tissues.

AIM: To investigate the relationship between infiltrating inflammatory cell and tumor angiogenesis in hepatocellular carcinoma (HCC) tissues and their clinicopathological features. METHODS: The paraffin-embedded specimens from 70 cases with HCC were stained using EliVision immunohistochemistry with mAbs against CD68, tryptase, and CD34. The counts of tumor-associated macrophage (TAM), mast cell (MC) and tumor microvessel (MV) were performed in the tissue sections. RESULTS: The mean counts of TAM, MC, and MV in HCC tissues were significantly higher than those in pericarcinomatous liver tissues (TAM: 69.31+/-11.58 vs 40.23+/-10.36; MC:16.74+/-5.67 vs 7.59+/-4.18; MV: 70.11+/-12.45 vs 38.52+/-11.16, P<0.01). The MV count in the patients with metastasis was markedly higher than that with non-metastasis (P<0.01). In addition, the MC count in the patients with poorly differentiated HCC was obviously higher than that with well differentiated HCC (P<0.01). The correlation analysis showed that the TAM count was significantly correlated with the count of MV (r=0.712, P<0.01), and the MC count was obviously correlated with the MV count (r=0.336, P<0.05). CONCLUSION: TAM and MC might be closely related to the enhancement of tumor angiogenesis. The MV count might be associated with tumor invasion and metastasis. Moreover, the MC count might be associated with tumor differentiation and prognosis of HCC.