Summary The rate of flow and nitrate and phosphorus content of the water from four drained sandy and clayey plots of size 12×60 m
cropped to continuous corn were determined following two annual applications of different rates (0, 260, 390 and 520 kg N/ha)
of cow manure slurry. The drain flow was directly related to the rainfall and was greatly influenced by soil texture. The
N losses were greater in 1972 (7.8 to 19.1 kg N/ha) than in 1971 (0.4 to 7.8 kg N/ha) because of more summer rainfall. Nitrogen
and phosphorus losses were larger from the sandy plots than from the clayey plots. The manure application rates had no apparent
effect on nitrogen losses in the drain water. 相似文献
Iron is an essential element for diverse biological functions. In mammals, the majority of iron is enclosed within a single prosthetic group: heme. In metazoans, heme is synthesized via a highly conserved and coordinated pathway within the mitochondria. However, iron is acquired from the environment and subsequently assimilated into various cellular pathways, including heme synthesis. Both iron and heme are toxic but essential cofactors. How is iron transported from the extracellular milieu to the mitochondria? How are heme and heme intermediates coordinated with iron transport? Although recent studies have answered some questions, several pieces of this intriguing puzzle remain unsolved. 相似文献
Plant nutrition management is known as an efficient strategy to control environmental constraints. This experiment was conducted in a climate control greenhouse with a hydroponic system. The high temperature (36 °C?±?1) was imposed on the pots after fruit formation. The studied factors were silicon in 2 concentrations (0 and 4 parts per thousand (ppt)) and salicylic acid in 3 concentrations (0, 0.5, and 1 mM). They were sprayed on cucumber plants 3 times and under high-temperature conditions to evaluate if they can regulate and improve the yield and quality of cucumber fruit under high-temperature conditions or not. The results showed that all treatments significantly improved the nutritional status, total yield, and fruit quality (including marketable yield (i.e., fruits that can be sold due to their good shape) and nitrate content). Under high-temperature conditions, foliar application of silicon had the highest effect on the increase of total yield and marketable fruit yield (respectively, 36.14% and 40.29% increase compared to the control treatment). Micro-nutrients concentrations in the leaf were significantly increased by Si but a reverse status happened for salicylic acid. Under high temperatures, both treatments also significantly decreased the nitrate content of the fresh matter of fruit but silicon was the superior treatment. Silicon and salicylic acid, respectively, had positive effects on mitigation of adverse effects of high temperature on cucumber plants. These findings suggest the use of these treatments under high-temperature conditions in greenhouse cucumber production.
Graphical Abstract
N–No3 content in dry matter of leaf (left) and fresh matter of fruit (right) affected by different treatments. *SaA0–SiA4: 4 ppt Si; SaA0.5–SiA0: 0.5 mM SA; SaA0.5–SiA4: 0.5 mM SA?+?4 ppt Si; SaA1–SiA0: 1 mM SA; SaA1–SiA4: 1 mM SA?+?4 ppt Si; control: without any SA and Si applications. Means in the same column followed by the same letter are not significantly different according to DMRT at (P?≤?0.05)
The present research was conducted in district Jhang, Pakistan, to evaluate the concentration of metals/metalloids in soil and pumpkin (Cucurbita maxima) irrigated with domestic wastewater. Data revealed that the levels of metals and metalloids in soil samples from two different sites were below the safe limits except Cd, whereas, in the vegetable, the concentrations of As, Se, Ni, Mo, Pb, Mn, and Cu were above the safe limits. The levels of 12 metals and metalloids in the soil were ranged between 0.14 to 22.76 mg/kg at site-I and 0.16 to 22.13 mg/kg at site-II. The levels of these metals in the vegetable were found 0.35 to 61.13 mg/kg at site-I and 0.31 to 53.63 mg/kg at site-II. The transfer factor at both sites was highest for As and Co. The pollution load index recorded for Se, Cu, Cd, Mo, Pb, and Co was greater than 1. The daily intake of As, Mn, and Mo was above the oral reference dose, which reflects that the intake of pumpkin is not safe for the inhabitants of the selected sites. The control measures should be taken to phytoextract heavy metals and metalloids from polluted sites so as to reduce the health risks. 相似文献
A simple enzyme-linked immunosorbent assay (ELISA) for sex hormone-binding globulin (SHBG) has been developed. Polyclonal antibody raised to SHBG purified to homogeneity was employed. The ELISA, which may be performed in under 4 h, shows no cross-reactivity with other serum proteins, has a sensitivity of less than 1.2 fmol per sample, demonstrates excellent correlation with ligand-binding techniques (r = 0.996; p less than 0.0001), and has intra- and inter-assay coefficients of variation of between 5-9% and 7-11% respectively. 相似文献
Microtubule-associated protein tau was purified from bovine brain microtubules by either (1) phosphocellulose chromatography, (2) heat treatment at pH 6.4, (3) heat treatment at pH 2.7, (4) heat treatment at pH 2.7 followed by extraction with perchloric acid and precipitation with glycerol, or (5) by precipitation with ammonium sulfate followed by extraction with perchloric acid. All of these tau preparations reacted specifically with antibodies to Alzheimer paired helical filaments. Affinity purified antibodies to tau labeled both Alzheimer neurofibrillary tangles and plaque neurites but not amyloid in Alzheimer brain tissue sections and labeled paired helical filament polypeptides on Western blots. Human brain tau and paired helical filament polypeptides co-migrated on sodium dodecyl sulfate-polyacrylamide gels. These results suggest that tau is a major component of Alzheimer paired helical filaments. 相似文献
t-Buthyoxycarbonyl-L -alanyl-α-aminiosobutyryl-L -alanyl-α-aminoisobutyryl-α-aminoisobutyric acid methyl ester (t-Boc-L -Ala-Aib-L -Ala-Aib-Aib-OMe), C24H43N5O8, an end-protected pentapeptide with a sequence corresponding to the 6th through the 10th residues in suzukacillin, crystallizes in the orthorhombic space group P212121 with a = 11.671, b = 14.534, c = 17.906 Å and z = 4. The molecule exists as a right-handed 310-helix with a pitch of 6.026 Å. The helix is stabilized by three 4 → 1 hydrogen bonds with the NH groups of Ala(3), Aib(4), and Aib(5) hydrogen bonding to the carbonyl oxygens of t-Boc, Ala(1), and Aib(2), respectively. The helical molecules arrange themselves in a head-to-tail fashion along the a direction in such a way that the NH groups of Ala(1) and Aib(2) hydrogen bond to the carbonyl oxygens of Aib(4) and Aib(5), respectively, of a translationally related molecule. The helical columns thus formed close-pack nearly hexagonally to form the crystal. 相似文献
The effect of acute gamma rays (60Co; 1 to 10 kR) on the vascular differentiation in stems of seedlings of Capsicum annuum L. long fruited cultivar at 8-loaf stage of development. Prooambium, phloem and xylem of irradiated seedlings showed an early initiation and maturation in terms of distance from the tip. Magnitude of these differences increased with the increasing exposures and time following irradiation. In irradiated seedlings there is a ohange in the developmental sequence of metaphloem and metaxylem when they first appear (in terms of number of leaf primordia). There is also a general increase in the number of procambial cells, sieve elements and vessel elements after irradiation. The early initiation and maturation of the vascular tissue is correlated with the growth inhibition resulting from cell death and suppression of cell division activity in the shoot apex. 相似文献