Yield and gas exchange of greenhouse tomato at different nitrogen levels under aerated irrigation.

Significant global warming increases over the last century have resulted in recent research focused on practices to reduce greenhouse gas (GHG) emissions. Agricultural management practices, such as nitrogen (N) fertilization and aerated irrigation (AI), have significantly increased crop yields by improving soil water and fertilizer availability, and have been widely adopted in recent years. However, the interactive impact of different growing seasons and management practices in the greenhouse on GHG emissions is unclear. This greenhouse study was conducted during Spring and Autumn cultivation periods in Yangling, China with five N application rates (0, 50, 150, 200,250 kg ha-1) and two irrigation methods (AI and conventional irrigation [CK]). The results indicated that AI and N application both increased tomato yield, but also increased soil CO2 and N2O emissions. The temperature was 4 °C higher during Spring cultivation than during Autumn cultivation, which significantly (P < 0.05) increased soil emissions of CO2, N2O, and net GHG by 10.6%, 43.8%, and 12.3%, respectively. However, the yield in Spring cultivation only increased by 5.1% (P > 0.05). Thus, among the selectable cultivation seasons, the cooler season (Autumn) along with AI and 200 kg N ha-1, was recommended to farmers to avoid adverse effects of a warming environment. AI and 150 kg N ha-1 in Spring cultivation could be recommended as an alternative measure to local farmers. Our results suggest that in a future warmer climate, reducing nitrogen fertilizer rate in conjunction with the use of AI will remain important practices for maintaining crop yield while reducing soil net GHG emissions. There is an urgent need to transform current management practices to offset the negative impacts of climate change.

[Spatial Variation of Heavy Metals in Soils and Its Ecological Risk Evaluation in a Typical Carya cathayensis Production Area].

In recent years, the problem of soil pollution has become more and more serious. The problem of soil heavy metal pollution and its related human health risks has become a hot spot at home and abroad. Carya cathayensis is a unique high-grade woody nut and oil tree from China, and there are few reports on heavy metal pollution in Carya cathayensis plantation soils. Therefore, in order to study the spatial variability of heavy metals and the risk of pollution in Carya cathayensis soil and to promote the sustainable development of the Carya cathayensis industry, Lin'an, a typical Carya cathayensis plantation area, was selected for this study. A total of 188 soil samples were collected from the study area. We systematically studied the spatial heterogeneity of soil heavy metal content in the study area based on GIS technology, geostatistics, Moran's I, and other spatial analysis methods. The single factor pollution index method, the Nemerow comprehensive pollution index method, and the potential ecological risk assessment method were used to evaluate the heavy metal pollution in the study area. The results indicated that the mean content of soil cadmium (Cd), copper (Cu), zinc (Zn), lead (Pb), nickel (Ni), and chromium (Cr) were 0.37, 40.76, 87.61, 30.10, 28.33, 56.57 mg·kg-1, respectively. The average values of Cd and Cu were 1.33 and 2.87 times of the background values, respectively, and the average content of other heavy metals did not exceed the background values. The results of the single factor Nemerow pollution index and potential ecological risk assessment methods showed that heavy metals in the study area exceeded the soil background values in some samples, and the second grade standard of soil environmental quality was exceed for Cd, Cu, Zn, Pb, and Ni in 31.38%, 31.38%, 2.65%, 0.53%, and 17.02% of the samples, respectively. This indicated that the soils in the study area had different accumulation characteristics for Cd, Cu, Zn, Pb, Ni, and Cr, and the local soil had reached pollution levels for Cd, Cu, Zn, Pb, and Ni. Among them, Cd was the most serious, reaching the degree of strong ecological damage, followed by Cu. In general, the heavy metal contents indicated a moderate degree of ecological damage. Based on the analysis of the semi-variance function, the Cd, Cu, and Ni in the soil were best fit with exponential models, the Zn and Pb were better fit with the Gaussian model, and Cr was consistent with the spherical model. Cd, Cu, Pb, Ni, and Cr had the strong spatial autocorrelation, with Nugget/Sill ratios of 12.1%, 4.6%, 14.9%, 2.6%, and 11.2%, respectively, while the Nugget/Sill ratio of Zn was 48.8%, indicating a medium spatial autocorrelation. Moran's I and Kriging interpolation results found that the heavy metals Cd, Cu, Zn, Pb, Ni, and Cr all had obvious spatial distribution patterns and local spatial aggregation phenomena. The high values of heavy metals in soils were mainly found in Taiyang, Daoshi, Qingliangfeng, Heqiao, and Tuankou, and the probability of the risk for contamination by Cd and Cu was higher in the study area. The high values of Cd, Cu, Zn, Ni, and Cr were mainly related to mining, while Pb was closely related to the application of potassium.

[Compensation effects of regulated deficit irrigation and tillering interference to winter wheat].

Pot experiments were carried out to explore the approach of optimizing crop group performance through restriction of individual growth redundancy and increasing crop yield potential. Two winter wheat varieties of 'Xiaoyan-22' (with moderate tillering ability) and 'Zhengmai-7698' (with strong tillering ability) were chosen to investigate the effects of two irrigation schedules (full irrigation and regulated deficit irrigation) and three kinds of tillering interference (only retaining the main stem and the biggest tiller at jointing stage; removing all nonbearing tillers at heading stage; and without any interference as the control treatment). Thus, we simulated the compensation effects of different water supplies and unpredictable disturbances on the physiology, growth, yield, and water use efficiency of winter wheat. The results showed that there existed growth redundancy for both varieties. Compared with 'Xiaoyan-22', 'Zhengmai-7698' had relatively higher tillering number but weak panicle traits. Regulated deficit irrigation and removing all nonbearing tillers at heading stage could reduce growth redundancy, weaken competitive ability, change source-sink relations, and optimize resources allocation. However, excessive elimination of redundancy (e.g. only retaining the main stem and the biggest tiller at jointing stage) could destroy the inherent root-shoot balance and functional structure of plant and lead to inadequate compensation. In contrast to the control treatment (full irrigation and without any disturbance), the combination of regulated deficit irrigation and removing all nonbearing tillers at heading stage could help crops sufficiently exploit and utilize their own regulation potentials at spatial and temporal scales and finally realize compensation growth. The combination above could increase the water use efficiency by 20.4% - 25.4% without remarkable impact on grain yield, and hence, could be suitable for wheat growth redundancy reduction.

Mild-to-moderate neurogenic pyrexia in acute cerebral infarction.

BACKGROUND: Pyrexia is often associated with unfavorable stroke outcomes. However, limited information is available on the relationship between the causes of poststroke hyperthermia and stroke prognosis, especially for mild-to-moderate neurogenic pyrexia in acute cerebral infarction. AIMS: To compare the differences in the clinical features and characteristics of pyrexia as well as its prognosis among acute cerebral infarction patients with mild-to-moderate neurogenic pyrexia, with infectious pyrexia, and without pyrexia. The focus was on mild-to-moderate neurogenic pyrexia. METHODS: A total of 709 patients with acute cerebral infarction were prospectively recruited and their clinical data were analyzed. RESULTS: No significant difference was detected in age, gender, history of smoking, hypertension, or diabetes among the 3 groups (p > 0.05). Patients with mild-to-moderate neurogenic pyrexia and those with infectious pyrexia had higher baseline National Institutes of Health Stroke Scale (NIHSS) scores (15.1 ± 6.7, p = 0.003; 14.3 ± 8.1, p = 0.002, respectively), lower 3-month Barthel index (BI) values (64.2 ± 40.7, p < 0.001; 61.9 ± 49.3, p < 0.001, respectively) and higher 3-month mortality rates (13%, p = 0.026; 16%, p < 0.001, respectively) than patients without pyrexia (NIHSS score 11.4 ± 7.9; BI 82.6 ± 39.8, and mortality rate 6%, respectively). No difference existed in these parameters between the 2 pyrexia groups (p > 0.05), but mild-to-moderate neurogenic pyrexia had an earlier onset and a shorter duration than infectious pyrexia (p < 0.001). CONCLUSIONS: Acute cerebral infarction patients with mild-to-moderate neurogenic pyrexia had a similar prognosis compared to those with infectious pyrexia. Mild-to-moderate neurogenic pyrexia is possibly associated with stroke severity.

tert-Butyl 6-acetamido-3,4-dihydro-2H-1,4-benzoxazine-4-carboxyl-ate.

The title mol-ecule, C(15)H(20)N(2)O(4), contains a benzene ring fused to an oxazine ring and one tert-but-oxy-carbonyl group bound to the N atom. An intra-molecular C-H⋯O inter-action occurs. In the crystal, mol-ecules are linked through inter-molecular N-H⋯O and C-H⋯O hydrogen bonds.

3-(2-Fluoro-phen-oxy)propanoic acid.

In the title compound, C(9)H(9)FO(3), the dihedral angle between the carboxyl group and the benzene ring is 79.4 (3)°. In the crystal, mol-ecules form centrosymmetric dimers through pairs of classical O-H⋯O hydrogen bonds. These are further linked by weaker C-H⋯O inter-actions, forming a three-dimensional network.

tert-Butyl 6-amino-3,4-dihydro-2H-1,4-benzoxazine-4-carboxyl-ate.

The title mol-ecule, C(13)H(18)N(2)O(3), contains a benzene ring fused to an oxazine ring and one tert-but-oxy-carbonyl group bound to the N atom of the oxazine ring. A weak intra-molecular C-H⋯O inter-action occurs. In the crystal, inter-molecular N-H⋯O and C-H⋯O hydrogen bonds stack the mol-ecules down the b axis. Weak C-H⋯N contacts connect the stacks, generating a three-dimensional network.

Consecutive GC base pairs determine the energy barrier of DNA duplex formation under molecularly crowded conditions.

The kinetics of DNA duplex formation was affected by the addition of PEGs with different masses (MW = 200-8000) to an aqueous solution; for each condition, two duplexes (5'-TAGGTTATAA-3'/5'-TTATAACCTA-3' and 5'-CAGGTCACAG-3'/5'-CTGTGACCTG-3') with different stabilities were formed after overcoming the same association activation energy barrier, suggesting that the formation of consecutive GC base pairs in the helices rather than the helix terminus is the initiation nucleus for DNA duplex formation not only in the absence, but also in the presence of PEGs.

The effect of the structure of cosolutes on the DNA duplex formation.

A living cell generally contains macromolecules occupying 20 approximately 40% of the total volume. In order to mimicking the crowded cellular environment, we chose different structure molecules, glycerol, ethylene glycol (EG) and poly(ethylene glycol) (PEG), as cosolutes. The thermodynamics and kinetics of DNA duplex formation in the presence of high concentration of glycerol, EG and PEG were investigated to discern nucleic acid behavior under molecular crowding condition. Comparing with the data obtained in the dilute solution, the melting temperature (T(m)) of a 10-mer DNA duplex (5'-TAGGTTATAA-3'/5'-TTATAACCTA-3') decreased by 4.8 degrees C, 5.6 degrees C, or 7.0 degrees C in the presence of 20 wt% glycerol, EG, or PEG200, respectively. The kinetic results revealed that the destabilization was not only caused by decreasing the association rate constant but also caused by great increasing the dissociation rate constant. These results are useful for understanding nucleic acid behavior in cell.