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INTRODUCTION: Ultrasound-guided thoracic paravertebral block (UTPB) is widely used for postoperative analgesia in thoracic surgery. However, it has many disadvantages. Thoracoscopy-guided thoracic paravertebral block (TTPB) is a new technique for thoracic paravertebral block (TPB). In this study, we compared the use of TTPB and UTPB for pain management after thoracoscopic radical surgery for lung cancer. METHODS: In total, 80 patients were randomly divided 1:1 into the UTPB group and the TTPB group. The surgical time of TPB, the success rate of the first puncture, block segment range, visual analog scale (VAS) scores at 2, 6, 12, 24, and 48 h post operation, and the incidence of postoperative adverse reactions were compared between the two groups. RESULTS: The surgical time of TPB was significantly shorter in the TTPB group than in the UTPB group (2.2 ± 0.3 vs. 5.7 ± 1.7 min, t = - 12.411, P < 0.001). The success rate of the first puncture and the sensory block segment were significantly higher in the TTPB group than in the UTPB group (100% vs. 76.9%, χ2 = 8.309, P < 0.001; 6.5 ± 1.2 vs. 5.1 ± 1.3 levels, t = - 5.306, P < 0.001, respectively). The VAS scores were significantly higher during rest and coughing at 48 h post operation than at 2, 6, 12, and 24 h post operation in the TTPB group. The VAS scores were significantly lower during rest and coughing at 12 and 24 h post operation in the TTPB group than in the UTPB group (rest: 2.5 ± 0.4 vs. 3.4 ± 0.6, t = 7.325, P < 0.001; 2.5 ± 0.5 vs. 3.5 ± 0.6, t = 7.885, P < 0.001; coughing: 3.4 ± 0.6 vs. 4.2 ± 0.7, t = 5.057, P < 0.001; 3.4 ± 0.6 vs. 4.2 ± 0.8, t = 4.625, P < 0.001, respectively). No significant difference was observed in terms of postoperative adverse reactions between the two groups. CONCLUSIONS: Compared with UTPB, TTPB shows advantages, such as simpler and more convenient surgery, shorter surgical time, a higher success rate of the first puncture, wider block segments, and superior analgesic effect. TTPB can effectively reduce postoperative pain due to thoracoscopic lung cancer radical surgery. TRIAL REGISTRATION: https://www.chictr.org.cn , identifier ChiCTR2300072005, prospectively registered on 31/05/2023.
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Non-structural carbohydrates (NSC) are essential substances for the tree growth and metabolism, and play an important role in environmental adaptation of trees. At temporal scale, NSC contents in trees have limited inter-annual variation, which could be attributed to the strategy of tree growth and carbon storage. Different factors influence NSC contents of trees in various climatic regions, which change substantially at the seasonal scale. At spatial scale, the variations of NSC content in trees show an insignificantly decreasing trend with the decreases of latitude at global and continental scales, which are mainly related to the hydrothermal gradients. The trend at regional scale is opposite because of the decrease of hydrothermal gradients and lower sample frequency. More sophisticated relations exist between the variations of NSC content in trees and altitudes, which are caused by species-specific characteristics and the variations of micro-habitat conditions. The variations of NSC content in trees at multiple spatial-temporal scales are generally determined by both biotic and abiotic factors, which are mainly dependent on the tradeoff among photosynthate production, respiratory depletion, and tree growth. Furthermore, the methods used for the determination of NSC content are different, which results in great uncertainties in comparing conclusions from different studies. The methods used for sample collection and measurement of NSC should be improved and unified to enhance the comparison among different studies. The NSC contents of trees in different age classes should be measured with all organs collected at multiple spatial-temporal scales. The underlying mechanisms, significance of NSC storage, transformation and allocation on tree growth and survival should be further discussed.
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Metabolismo dos Carboidratos , Árvores , Carboidratos , Carbono , Estações do AnoRESUMO
Tree seedlings are one of the important components in alpine treeline ecotone, whose regeneration is crucial to treeline migration in response to climate change. We analyzed the spatial distribution, regeneration of tree seedlings and their responses to climate change in treeline ecotone in recent decades. The spatial distribution of tree seedlings in treeline ecotone is dominated by diffuse and clustered forms, with different indicative significance for spatial dynamics of treeline. At global scale, the altitude distribution limits of tree seedlings are usually related to the length and average temperature of growing season, along with the species characteristics. However, precipita-tion plays an important role at regional scale. The initial stage of seedling recruitment is restricted by seed source, which determines seed distribution and germination to a great extent. Microenvironment facilitates seedling regeneration by providing shelter for establishment and improving their survival rate. The regeneration process is more relevant to multiple biotic, abiotic factors and their interactions. With global warming, rising temperature in treeline ecotone and more precipitation are more suitable for seedling regeneration of treeline species. The expansion of seedlings to higher elevations could be considered as the portent of timberline upwards migration. Due to species-specific adaption strategy, however, some trees only increase seedling density and timberline location is constant. In the future, it is necessary to take precise dating techniques, such as tree-ring and 14C dating, and conduct long-term in-situ monitoring and indoor simulation experiments. To provide scientific basis for mountain ecosystem restoration and conservation, we should strengthen the studies on spatial patterns and regeneration mechanism of seedlings in treeline ecotone at multiple spatio-temporal scales, the adaptation strategies of tree seedlings in different types of treeline ecotone and treeline dynamics prediction.
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Mudança Climática , Ecossistema , Plântula , Árvores , AltitudeRESUMO
Diurnal variation and its influencing factors of leaf water potential (ψl) of Spinifex littoreus on the nebkhas in two succession periods were measured on the coast of Pingtan Island, Fujian Province. The results showed that the diurnal variation of ψl of S. littoreus mainly demonstrated a 'W' curve pattern, with a temporary rise at midday. The mean ψl of S. littoreus on the nebkhas at developing stage was higher than that at stabilizing stage, and recovered better during the night. ψl of S. littoreus was positively related to the atmospheric water potential (ψa) and relative humidity, negatively related to air temperature, but had no significant correlation with the soil water potential at different depthes. ψl of S. littoreus on the interdune depression at developing stage was higher than that on the windward slope and on the leeward slope from 10:00 to 16:00, and that on the windward slope was lower than that on the leeward slope all day long except at 10:00 and at 12:00. The variation of ψl of S. littoreus on the leeward slope was higher than that on the windward slope, and the minimal variation was found on the interdune depression, without statistical significance. ψl of S. littoreus on the windward slope was positively correlated with ψa and relative humidity, while negatively correlated with air temperature. ψl of S. littoreus on the leeward slope and the interdune depression were correlated with meteorological factors, but they had no significant relationship.
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Folhas de Planta , Água , China , Ilhas , SoloRESUMO
By measuring the surface shear strength of Nitraria tangutorun nebkhas at different succession stages in the fringe of Minqin oasis, and selecting several typical nebkhas at stabilizing stage to investigate its surface erosion rates before and after removing crust and vegetation, the surface erosion-resistance of N. tangutorun nebkhas and related affecting factors were studied. The results showed that the nebkhas had the highest surface shear strength (0.31-0.79 kg cm(-2)) at stabilizing stage, and the lowerest one (0.06-0.15 kg cm(-2)) at rudimental stage. The surface shear strength of nebkhas at stabilizing stage was significantly higher than that at other succession stages (P <0.01), and at the other succession stages except degradation stage, there was no significant difference in the surface shear strength in windward and leeward (P >0.05). After removing crust and vegetation, the surface shear strength of nebkhas at stabilizing stage was greatly reduced, with the difference before and after removing the crust and vegetation being significant (P <0.01). However, there was no obvious difference between different slope positions (P >0.05). Keeping both vegetation and crust, deposition occured on both slope positions of nebkhas; removing crust but keeping vegetation, the deposition reduced a little; removing vegetation but keeping crust, the deposition reduced greatly; while removing both vegetation and crust, nebkhas surface was severely eroded.