Somatic and obstetrical aspects of magnesium deficiency (Clinical lecture)

Homeostasis of magnesium in the body is a prerequisite for human health. As required macrocell for cells and tissues, magnesium is involved in many physiological processes, to ensure the normal functioning of the organism. At the same time a number of large-scale studies established a significant prevalence of magnesium deficiency, which is in the general population is 14.5%, and the suboptimal level observed in 33.7%. The resolution of the International Advisory Council for magnesium deficiency in obstetrics and gynecology noted urgency of the problem and the importance of correction of magnesium deficiency in pregnant and gynecological patients. The lecture covered various aspects of magnesium deficiency are considered violations of the pathophysiological mechanisms of magnesium homeostasis, Principles on the Use of magnesium products with preventive and curative purposes. Key words: magnesium deficiency, clinical symptoms of hypomagnesemia, pregnancy.

Design and Deposition of Infrared Antireflection Protection Film on Magnesium Fluoride Substrate for 3~5 μm

The infrared antireflection protection film is designed and deposited on magnesium fluoride substrate for 3~5 μm. The multilayer antireflection film is designed and prepared by ion beam assisted electron-beam deposition. After repeated experiments, the absorption peak of SiO2 is found at 3000nm,using MgF2 and SiO2 as the low-index materials to reduce the absorption. The coating structure is Sub|1.46H1.37L2.19H1.45L2.49M|Air. DLC (diamond-like carbon) protection coating is deposited by radio frequency plasma enhanced chemical vapor deposition (RF-PECVD). Through contrast tests, the best deposition process is obtained (the butane flow rate is 5sccm/s, deposition temperature is 80°C) by setting deposition time as invariant, the reaction gas flow rate and deposition temperature as variables. Meanwhile the problem of associativity between antireflection film and DLC protection coating is solved by adding a Si transition layer. The result shows that the average transmittance of this film in 3~5μm is 95.5%, and this film can withstands harsh environment tests. Key words: Magnesium fluoride substrate; Antireflection protection film; 3~5 μm infrared band Document Code: A Article ID: DIO

Homoleptic magnesium bis-phosphinimide derivatives

The homoleptic Mg-phosphinimide complexes Mg2(µ-NP-t-Bu3)2(NP-t-Bu3)2 (1) and Mg3(µ-NP-i-Pr3)4(NP-i-Pr3)2 (2) were obtained from the reaction of 2 equiv. of the phosphinimines HNPR3 (R = t-Bu, i-Pr) with MgBu2. Spectroscopic and crystallographic studies confirmed the dimeric and trimeric structures of compounds 1 and 2, respectively. Key words: magnesium, phosphinimides, homoleptic, crystal stuctures.

Part 2: Efficient strategies for the construction of variably substituted bicyclo[5.3.1]undecenones (AB-taxane ring systems) and their conversion to tricyclo[9.3.1.03,8]pentadecenones (ABC taxane ring systems) and bicyclo[2.2.2]octanones

The extension of our strategies for the construction of cyclic molecules containing variably substituted bicyclo[5.3.1]undecenones (AB taxane ring systems) for the synthesis of the tricyclo[9.3.1.03,8]pentadecenone (ABC taxane ring system) and bicyclo[2.2.2]octanones are described. These routes employ a multi-component coupling protocol that employs sequential magnesium-mediated carbometallation of allyl-substituted propargyl alcohols followed by diastereoselective Lewis acid catalyzed intramolecular Diels–Alder reactions (IMDA). Subsequent ring-closing metathesis (RCM) afforded the ABC taxane core structure. Enone accelerated [3,3] sigmatropic rearrangements (Cope rearrangements) generated the bicyclo[2.2.2]octanone nucleus. In the presence of a Lewis acid, the dienophile precursor underwent a tandem reaction via the adduct directly to the bicyclo[2.2.2]octanones. This is the first example of a novel enone accelerated carbocycle Cope rearrangement and provides direct access to bicyclo[2.2.2]octanones by a new route that compliments the traditional cyclohexadiene cycloaddition approach. Key words: magnesium chelate, Lewis acid, taxanes, Diels–Alder, sigmatropic rearrangement, oxy-Cope, ring-closing metathesis, bicyclo[2.2.2]octanone.

Effects of low levels of dietary magnesium silicate supplementation on the performance and carcass characteristics of pigs from 24 to 68 kg body weight

Magnesium silicate (HMS) supplementation at 2.0% of the diet did not influence the growth rate, feed conversion efficiency or carcass characteristics of castrated male growing pigs. However, feeding HMS decreased (P < 0.01) the liver weight and increased (P < 0.07) the cross-sectional area of longissimus muscle in pigs slaughtered at 68 kg body weight. Key words: Magnesium silicate, growth rate, carcass characteristics

The effect of ante mortem electrolyte therapy on animal physiology and meat quality in pigs segregating at the halothane gene

The present study was initiated to investigate the effect of oral potassium (600 mg, slow release, 24 h preslaughter), intramuscular (IM) magnesium (500 mg MgSO4, 2 h preslaughter) or slow release magnesium (Magnesium-aspartate-hydrochloride (Mg Asp) 20 or 40 (g d−1 for 5 d) on animal physiology and pork quality. Experiments were undertaken on 318 barrows and gilts (100 kg ± 5 kg) represented by three genotypes segregating at the halothane locus (nn, Nn and NN genotypes). Experiment 1 indicated that the oral potassium effectively (P ≤ 0.05) reduced pCO2 values in the nn genotype. Intramuscular injectable magnesium treatments were also found to raise plasma magnesium (P < 0.05) but did not alter muscle, liver or heart tissue levels. Both oral potassium and i.m. magnesium exacerbated subjective pork structure and texture scores but were found to increase muscle brightness and hue (higher b* value). In exp. 2, oral magnesium-aspartate (Mg Asp) was found to raise plasma, but not tissue, levels of magnesium. When fed to a group of halothane carrier pigs (Nn genotype), Mg Asp reduced muscle temperature 45 min post-stunning, increased muscle redness (CIE a* value) and reduced muscle drip loss (P < 0.06). It was concluded that oral potassium and i.m. magnesium as administered in the present study had no beneficial effects on pork quality but that the beneficial effects of Mg Asp on meat colour and drip loss may warrant further investigation. Key words: Magnesium, potassium, preslaughter, pork quality, PSE pork