Dynamic changes in leaf wax n-alkanes and delta C-13 during leaf development in winter wheat under varied irrigation experiments

Leaf wax n-alkanes serve as biomarkers that record environmental information with their carbon isotopic composition (delta C-13(alk)) recording water availability. Agricultural and paleoclimate applications would benefit from a greater understanding of how water shortages are recorded in delta C-13(alk) across the growing season, and controlled experiments can contribute to understanding as they constrain cause and effect, although they represent highly simplified versions of natural ecosystems. In this study, we use fieldgrown winter wheat (Triticum aestivum L.) under three water treatments (full irrigation, deficit irrigation and dry/rain-fed) to investigate the changes of flag (top) leaf traits including leaf mass per area, wax nalkanes and carbon composition of bulk leaf and n-alkanes (delta C-13(alk)) during leaf development. We find that leaf wax n-alkane synthesis ceases when the leaf reaches its maximum area (fully expanded) under dry conditions. However, fully expanded leaves can still increase their n-alkane concentrations by 42% and 70% under deficit and full irrigation, respectively. Total leaf wax n-alkane concentrations and delta C-13(alk) show no difference at leaf flush between rain-fed (dry) and deficit irrigation treatments, but delta C-13(alk) under full irrigation is more depleted as expected, with more pronounced offsets between the experiments developing during the growing season. delta C-13(alk) decreases logarithmically during leaf development perhaps indicating a shift from stored carbohydrate to fresh photosynthate and shoot growth related responses. Our results indicate that the water information at leaf flush is not `locked-in' to the delta C-13(alk) signal carried by the leaf wax n-alkanes. Instead, the first flush likely reflects the signal of stored carbohydrate more so than ambient environmental conditions. Total leaf wax n-alkane concentrations and delta C-13(alk) at the mature stage carry a more complete record of differences in water use efficiency experienced during the growing season. (C) 2020 Elsevier Ltd. All rights reserved

Pulverization characteristics of coal from a strong outburst-prone coal seam and their impact on gas desorption and diffusion properties

Coal seams that are prone to strong outbursts have low strength and cause heavy structural damage to the seam. Their outburst risk is highly related to the release of the adsorbed coalbed gas, which is controlled by the gas desorption and diffusion characteristics of coal. In the Haizi Coal Mine, China, an extremely high gas outburst risk was detected, and the coals from this area were found to have an unprecedented high degree of fragmentation and were present in the pulverized state. To explain the pulverization characteristics of the pulverized coal, the related physical parameters were investigated; the gas desorption and diffusion properties of the pulverized coal were analyzed and compared with those of the unpulverized coal. The results indicated that the pulverized coal could easily reach the required degree of fragmentation for a coal and gas outburst to occur. Furthermore, the pore volume and specific surface area of the pulverized coal differed according to the coal particle size. Compared with the unpulverized coal, the gas desorption and diffusion properties of the pulverized coal were largely varied, and the pore structure of the pulverized coal was much simpler. The formation of pulverized coal is believed to be closely related to complex geological conditions

Intracellular Proteolytic Disassembly of Self-Quenched Near-Infrared Nanoparticles Turning Fluorescence on for Tumor-Targeted Imaging

The design of tumor-targeting, intracellular protease-activatable near-infrared fluorescence (NIRF) nanoprobes is broadly interesting but remains challenging. In this work, we report the rational design of a NIR probe Cys­(StBu)-Lys­(Biotin)-Lys-Lys­(Cy5.5)-CBT (<b>1</b>) to facilely prepare the self-quenched nanoparticles <b>1-NPs</b> for tumor-targeted imaging <i>in vitro</i> and <i>in vivo</i>. The biotinylated <b>1-NPs</b> could be actively uptaken by biotin receptor-overexpressing tumor cells via receptor-mediated endocytosis. Upon intracellular proteolytic cleavage, <b>1-NPs</b> were disassembled to yield the small molecular probe Lys­(Cy5.5)-Luciferin-Lys­(Biotin)-Lys-OH (<b>1-D-cleaved</b>), accompanied by fluorescence “Turn-On”. With this NIRF “Turn-On” property, <b>1-NPs</b> were successfully applied for tumor-targeted imaging. We envision that our nanoparticles could be applied for fluorescence-guided tumor surgery in the near future

Effects of Salinity on Growth Performance, Digestive Enzymes, and Nonspecific Immunity in Juvenile Hybrid Grouper (Epinephelus fuscoguttatus♀ × E. lanceolatus♂)

In recent years, many studies on the effects of salinity on fish growth performance have been performed. A series of research results confirmed that appropriate salinity could guarantee healthy fish growth, while under extremely high or low salinity, the fish growth would be inhibited. Therefore, salinity is one of the critical factors ensuring aquaculture success. However, most previous studies only focused on fish growth and survival, without systematically analyzing the physiological and biochemical indicators or performing regression analysis of optimal salinity, especially for the hybrid grouper (Epinephelus fuscoguttatus♀×E. lanceolatus♂). A 28-day experiment was conducted to evaluate the effects of different salinities on growth performance, body composition, digestive enzyme activities, antioxidant indices, and serum biochemical indices of the juvenile hybrid grouper [initial mean weight of (29.99±2.60) g]. This study used six salinity levels of 10, 15, 20, 25, 30, and 35, named S1 (control), S2, S3, S4, S5, and S6, respectively. During the experiment, the water temperature was kept at 25–28 ℃, DO≥6 mg/L, pH 8–9, and the contents of ammonia and nitrite nitrogen were both lower than 0.1 mg/L. Firstly, the results showed that different salinity levels had different impacts on the juvenile hybrid grouper growth performance. The weight growth rate (WGR) and special growth rate (SGR) first increased and then decreased with the rise in salinity and peaked in the S4 group, which were significantly higher than those of the S1 and S6 groups (P 0.05). The quadratic regression model analysis based on WGR and FE indicated that the optimal salinities were 22.18 and 23.16. Secondly, the whole fish crude lipid content in the S4 group (10.86%) was significantly higher than in the S1 (9.30%), S2 (9.62%), S3 (9.79%), and S6 (9.22%) groups (P 0.05). The muscle crude protein content and the whole fish and muscle moisture and ash had no significant differences among all groups (P > 0.05). Thirdly, juvenile hybrid grouper´s intestinal lipase and trypsin activities in the S3 and S4 groups were significantly higher than in other groups (P 0.05). Fourthly, salinity changes greatly impacted the antioxidant capacity of the juvenile hybrid grouper liver. The activities of the liver superoxide dismutase (SOD), total antioxidant capacity (T-AOC), and catalase (CAT) were significantly higher in the S1 and S6 groups than in other groups (P < 0.05). The liver malondialdehyde (MDA) content in the S3 and S4 groups were significantly lower than that of other groups (P < 0.05). Fifthly, lower activity levels of the aspartate aminotransferase (AST), cereal third transaminase (ALT), and alkaline phosphatase (AKP) in serum were found in the S3 and S4 groups, which were significantly lower than those of the S1 and S6 groups (P < 0.05). Moreover, the ALT activity in the S6 group was significantly lower than in the S1 group (P < 0.05). The lower activity level of lactate dehydrogenase (LDH) in serum was also found in the S3 and S4 groups, which were significantly lower than in other groups (P < 0.05). In summary, these results indicated that optimal salinity (20–25 mmol/L) could improve the juvenile hybrid grouper growth, while increasing the activities of digestive enzymes, antioxidant properties, and nonspecific immunity capacity, protecting the fish health. At the same time, the quadratic regression model analysis based on WGR and FE indicated that the optimal salinity for juvenile hybrid grouper is between 22.18 and 23.16

Paclitaxel Enhances Carboplatin-DNA Adduct Formation and Cytotoxicity

This rapid report focuses on the pharmacodynamic mechanism of the carboplatin/paclitaxel combination and correlates it with its cytotoxicity. Consistent with the synergistic to additive antitumor activity (the combination index ranging from 0.53 to 0.94), cells exposed to this combination had significantly increased carboplatin-DNA adduct formation when compared to that of carboplatin alone (450 ± 30 versus 320 ± 120 adducts per 10(8) nucleotides at 2 h, p = 0.004). Removal of paclitaxel increased the repair of carboplatin-DNA adducts: 39.4 versus 33.1 adducts per 10(8) nucleotides per hour in carboplatin alone (p = 0.021). This rapid report provides the first pharmacodynamics data to support the use of carboplatin/paclitaxel combination in the clinic

Coronary Anomalies in 11,267 Southwest Chinese Patients Determined by Angiography

Background. The prevalence of coronary artery anomalies (CAAs) is rare and varies among different countries or areas. More importantly, the symptoms exhibited by some CAAs make the diagnosis of coronary artery disease (CAD) difficult and hamper the physician from making the right intervention for CAD patients. Objective. To investigate the prevalence of CAAs in 11,267 patients from three hospitals in Southwest China. Methods. 11,267 patients who have undergone coronary angiography from three Southwest China hospitals were investigated retrospectively. Dominance patterns, prevalence, and the location of each CAA were recorded and analyzed. Results. The presence of a dominant right coronary artery (RCA) was found in 60.58% of patients. CAAs were found in 11.12% (1258) patients, and 87.66% anomalies were located in the left anterior descending (LAD) artery and its branches. Most of CAAs were found to be myocardial bridges (MBs, 1060 cases, 9.41%). Other CAAs included anomalous coronary origin (43 cases, 0.38%), coronary artery fistulas (CAFs, 36 cases, 0.32%), and coronary artery aneurysm or ectasia (119 cases, 1.06%). It also noted that most anomalies were found with RCA originating from the left coronary sinus (79.07%), most CAFs were located in the LAD and its branches (58.33%), and most coronary artery ectasias were located in the RCA (43.25%). Conclusions. CAAs in patients from Southwest China were unique compared to other studies. Recognition of these CAAs is important for accurate diagnosis and treatment choice of patients with chest pain

Paclitaxel Enhances Carboplatin-DNA Adduct Formation and Cytotoxicity

This rapid report focuses on the pharmacodynamic mechanism of the carboplatin/paclitaxel combination and correlates it with its cytotoxicity. Consistent with the synergistic to additive antitumor activity (the combination index ranging from 0.53 to 0.94), cells exposed to this combination had significantly increased carboplatin-DNA adduct formation when compared to that of carboplatin alone (450 ± 30 versus 320 ± 120 adducts per 10(8) nucleotides at 2 h, p = 0.004). Removal of paclitaxel increased the repair of carboplatin-DNA adducts: 39.4 versus 33.1 adducts per 10(8) nucleotides per hour in carboplatin alone (p = 0.021). This rapid report provides the first pharmacodynamics data to support the use of carboplatin/paclitaxel combination in the clinic. [Image: see text