2,749 research outputs found

    Haplotype Distribution and Evolutionary Pattern of miR-17 and miR-124 Families Based on Population Analysis

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    Background: MicroRNAs (miRNAs) are small, endogenously expressed non-coding RNAs that regulate mRNAs posttranscriptionally. Previous studies have explored miRNA evolutionary trend, but evolutionary history and pattern in the miRNA world are still not fully clear. In the paper, we intended to analyze miRNA haplotype distribution and evolutionary network by analyzing miRNA sequences of miR-17 and miR-124 families across animal species as special populations. Principal Findings: 31 haplotypes were detected in miR-17 family while only 9 haplotypes were defined in miR-124 family. The complex miR-17 family was mainly distributed in vertebrates, but miR-124 was shared by more animal species from Caenorhabditis to Homo and had a wide distribution spectrum. Some haplotypes of the two miRNA families appeared discontinuous distributions across animals. Compared with a simple phylogenetic network in miR-124 family, miR-17 family indicated a complex network with some median vectors that might be lost ancestral or potential miRNA haplotypes. By analyzing different miRNAs across 12 animal species, we found these small RNAs showed different haplotype diversities, haplotype distributions and phylogenetic networks. Conclusions: Different miRNAs had quite different haplotype distributions and evolutionary patterns. Discontinuous distributions of miRNAs and median vectors in phylogenetic networks implied more members in the miRNA world. miRN

    Effects of Dietary L-carnitine and Betaine on Serum Biochemical Indices of Large Yellow Croaker (Pseudosciaena crocea) Cultured in Floating Net Cages

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    Abstract: The objective of this study was to investigate the biochemical changes of large yellow croaker as affected by dietary supplements. Large yellow croaker (Pseudosciaena crocea) is a marine species that is widely cultured in China due to its high commercial value. However, the cage-cultured large yellow croakers were found to be less tasty compared with wild large yellow croakers due to high lipid in their body, which significantly impacts the commercial markets. Triglycerides, cholesterol and free fatty acids are main lipid ingredients in the animal body. The fish were fed with basal diet or basal diet supplemented with L-carnitine (0.08% of dry weight diet) or betaine (0.8% of dry weight diet) for 12 weeks in seawater floating net cages (3×2×1.5 m) each holding 60 fishes. Three net cages were assigned to each dietary treatment, as replications. The seawater temperature ranged from 18 to 31°C and salinity from 25 to 28 g/kg. Fish were hand-fed one of the experimental diets to apparent satiety twice daily (05:00 and 17:30) throughout the 12 week experimental period. The results indicate that L-carnitine or betaine in diets significantly reduced Serum Triglyceride (STG) and Serum Cholesterol (SCH) levels while increased Serum Free Fatty Acids (SFFA) content (p<0.05). The diets of L-carnitine or betaine supplements on serum biochemical indices of that fish species have positive effects. These results suggested that the supplementation with L-carnitine or betaine is one of the effective ways to improve the meat quality of large yellow croakers cultured in floating net cages

    A Mechanical Model and its Experimental Verification for a Water Injection String in a Highly Deviated Well

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    Water injection strings in highly deviated wells are subjected to complex forces on the string bore. In this work, a mechanical model is developed for these forces and for those on downhole tools. On the basis of this model, and taking account of the characteristics of the string in different working conditions, a temperature field model and a pressure field model are introduced, and a statically indeterminate structural calculation method is adopted. A force tester for highly deviated wells is developed and used in eight tests on strings in the Jidong Nanpu oilfield making a comparison between the measurements from the tests and the results of calculations using the mechanical model indicates that the mechanical model exhibits high computational accuracy, with the errors at the wellhead being no more than 10%, and that the forces on packers calculated from the model are in accordance with those measured in the tests. Thus, the mechanical model developed in this work is suitable for analyzing the forces on water injection strings and downhole tools in highly deviated wells

    Safety of Individual Medication of Ma Qian Zi (Semen Strychni) Based upon Assessment of Therapeutic Effects of Guo's Therapy Against Moderate Fluorosis of Bone

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    ObjectiveTo assess the safety of individual medication of Guo's Ma Qian Decoction on the basis of effective treatment of fluorosis of bone with Guo's therapy.MethodsOne hundred and fourteen cases of moderate fluorosis of bone were randomly divided into a treatment group (n=60) and a control group (n=54) between December 2007 and August 2009 by using the block randomized method and a central random system. At the same time of basic treatment, the patients in the treatment group were orally administrated with Guo's Ma Qian Decoction. The initial dose of Ma Qian Zi (Semen Strychni) was 0.4 g and increased by 0.05 g every two days, with the doses of other drugs unchanged, until the patient had “nux vomica response”. For the patients with no “nux vomica response”, the dosage was continued to increase and the maximum dosage was not more than 1.2 g/day. The control group was treated with decoction placebo. The changes of strychnine and brucine contents before and after processing and after decoction of Ma Qian Zi (Semen Strychni) were determined with reversed-phase high-performance liquid chromatography, which were controlled within ranges stipulated in the Pharmacopeia; Adverse events were analyzed; Blood strychnine and brucine contents in 10 cases who had taken the drugs were determined.Results1) Strychnine (2.125%) and brucine (1.425%) contents before processing of Ma Qian Zi and 1.88% and 1.31% after processing all conformed with the standards of strychnine (1.2–2.2%) and brucine (no less than 0.8%) stipulated in the Pharmacopeia. When the maximum dosage of Ma Qian Zi was 1.2 g/day, strychnine in the decoction was 11.17 mg and brucine was 7.44 mg, which all conformed with the maximum limited amount (strychnine 13.32 and brucine no less than 4.8 mg) stipulated in the Pharmacopeia. 2) Eight cases had “nux vomica response” in the treatment group and one case in the control group, with a significant difference between the two groups (P<0.05). 3) Altogether 18 cases had adverse events, with an incidence rate of 15.38% (8 cases) in the treatment group and 18.52% (10 cases) in the control group, with no difference between the two groups (P>0.05); Among them, 10 cases (8.77%) with the adverse event were not related with therapeutic drugs, with an incidence rate of 6.67% (4 cases) in the treatment and 11.11% (6 cases) in the control group, with no significant difference between the two groups (P>0.05). Seven cases had suspicious relative adverse events, the risk in the treatment group was 0.658 times of the control group, with no significant difference (P>0.05), and one case had the toxic reaction of nux-vomica seed. 4) Strychnine and brucine were unable to be detected in the blood in all points of time in the 10 cases who had taken the drugs, indicating that plasma strychnine and brucine contents were lower than the minimum detectable amount (10 ng), and accumulation of strychnine and brucine were not found in blood of the patient during and after administration for 8 weeks.ConclusionThe individual medication of Ma Qian Zi (Semen Strychni) in the Guo's therapy has a better safety

    Ferro-rotational domain walls revealed by electric quadrupole second harmonic generation microscopy

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    Domain walls are ubiquitous in materials that undergo phase transitions driven by spontaneous symmetry breaking. Domain walls in ferroics and multiferroics have received tremendous attention recently due to their emergent properties distinct from their domain counterparts, for example, their high mobility and controllability, as well as their potential applications in nanoelectronics. However, it is extremely challenging to detect, visualize and study the ferro-rotational (FR) domain walls because the FR order, in contrast to ferromagnetism (FM) and ferroelectricity (FE), is invariant under both the spatial-inversion and the time-reversal operations and thus hardly couple with conventional experimental probes. Here, an FR candidate NiTiO3\mathrm{NiTiO_{3}} is investigated by ultrasensitive electric quadrupole (EQ) second harmonic generation rotational anisotropy (SHG RA) to probe the point symmetries of the two degenerate FR domain states, showing their relation by the vertical mirror operations that are broken below the FR critical temperature. We then visualize the real-space FR domains by scanning EQ SHG microscopy, and further resolve the FR domain walls by revealing a suppressed SHG intensity at domain walls. By taking local EQ SHG RA measurements, we show the restoration of the mirror symmetry at FR domain walls and prove their unconventional nonpolar nature. Our findings not only provide a comprehensive insight into FR domain walls, but also demonstrate a unique and powerful tool for future studies on domain walls of unconventional ferroics, both of which pave the way towards future manipulations and applications of FR domain walls
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