Gene/Protein Disease Symptom Drug Enzyme Compound
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Electrocardiogram RR intervals duration reduce rapidly in the first seconds of dynamic exercise mainly due to a cardiac vagal withdrawal. However, it remains unclear if this response varies between exercises performed with different body segments (i.e. arm vs. leg). Our aim was to compare the vagal withdrawal at the onset of arm and leg dynamic exercise. Cardiac vagal withdrawal was assessed by the 4-s exercise test (4sET), a pharmacologically validated and highly reliable procedure. Initially, 60 healthy subjects performed the 4sET using arms (ARM 4sET) and legs (LEG 4sET), in a random order. Later, 20 of them repeated the testing, controlling for cycling rate and time of exercise onset within a RR interval, potential intervenient variables. Similar results were found for ARM and LEG 4sET considering the RR interval duration obtained immediately before the onset of exercise (RRB) (mean +/- SEM; 852 +/- 23 vs. 857 +/- 23 ms; P = 0.55), the shortest RR interval duration during exercise (RRC) (570 +/- 10 vs. 563 +/- 10 ms; P = 0.22) and the cardiac vagal index (CVI), which is the ratio between RRB and RRC (1.49 +/- 0.03 vs. 1.52 +/- 0.03; P = 0.10). Furthermore, high intraclass correlation coefficients were found (RRB r (i) = 0.94, P < 0.001; RRC r (i) = 0.85, P < 0.001; CVI r (i) = 0.81, P < 0.001). We conclude that similar cardiac vagal withdrawal was induced by 4-s fast unloaded cycling exercise performed with arms or legs.
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PMID:Similar cardiac vagal withdrawal at the onset of arm and leg dynamic exercise. 1808 83

The objective of the present investigation was to reduce the bitterness with improved dissolution, in acidic medium (pH 1.2), of mefloquine hydrochloride (MFL). Microparticles were prepared by coacervation method using Eudragit E (EE) as polymer and sodium hydroxide as precipitant. A 3(2) full factorial design was used for optimization wherein the drug concentration (A) and polymer concentration (B) were selected as independent variables and the bitterness score, particle size and dissolution at various pH were selected as the dependent variables. The desirability function approach has been employed in order to find the best compromise between the different experimental responses. The model is further cross validated for bias. The optimized microparticles were characterized by FT-IR, DSC, XRPD and SEM. Bitterness score was evaluated by human gustatory sensation test. Multiple linear regression analysis revealed that the reduced bitterness of MFL can be obtained by controlling the dissolution of microparticles at pH 6.8 and increasing the EE concentration. The increase in polymer concentration leads to reduction in dissolution of microparticles at pH > 5 due to its insolubility. However the dissolution studies at pH 1.2 demonstrated enhanced dissolution of MFL from microparticles might be due to the high porosity of the microparticles, hydrophilic nature of the EE, and improved wettability, provided by the dissolved EE. The bitterness score of microparticles was decreased to zero compared to 3+ of pure ARM. In conclusion the bitterness of MFL was reduced with improved dissolution at acidic pH.
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PMID:Design and optimization of mefloquine hydrochloride microparticles for bitter taste masking. 1843 70

Magnesium alloys containing rare earth elements are attractive as lightweight structural materials due to their low density, high-specific strength and recycling efficiency. Mg-Zn-Gd system is one of promising systems because of their high creep-resistant property[1]. It is reported that the coherent precipitation formation of the 14H long period stacking ordered structure (LPSO) in Mg-Zn-Gd system at temperatures higher than 623 K[2,3]. In this study, the 14H LPSO phase formed in Mg-Zn-Gd alloys were investigated by multi-scale characterization with X-ray computer tomography (X-CT), focused ion beam (FIB) tomography and aberration-corrected STEM observation for further understanding of the LPSO formation mechanism.The Mg89.5 Zn4.5 Gd6 alloy ingots were cast using high-frequency induction heating in argon atmosphere. The specimens were aged at 753 K for 24 h in air. The aged specimen were cut and polished mechanically for microstructural analysis. The micrometer resolution X-CT observation was performed by conventional scaner (Bruker SKY- SCAN1172) at 80 kV. The FIB tomography and energy dispersive x-ray spectroscopy (EDS) were carried out by a dual beam FIB-SEM system (Hitachi MI-4000L) with silicon drift detector (SDD) (Oxford X-Max(N)). The electron acceleration voltages were used with 3 kV for SEM observation and 10 kV for EDX spectroscopy. The 3D reconstruction from image series was performed by Avizo Fire 8.0 software (FEI). TEM/STEM observations were also performed by transmission electron microscopes (JEOL JEM 2100, JEM-ARM 200F) at the acceleration voltage of 200 keV.The LPSO phase was observed clearly in SEM image of the Mg89.5Zn4.5Gd6 alloy at 753 K for 2h (Fig.1 (a)). The atomic structure of LPSO phase observed as white gray region of SEM image was also confirmed as 14H LPSO structure by using selected electron diffraction patterns and high-resolution STEM observations. The elemental composition of LPSO phase was determined as Mg97Zn1Gd2 by EDS analyses. The 3D representation of the LPSO phase shown in Fig.1 (b) reveals that the shape of LPSO phase was disk-like. The calculated volume fraction of LPSO was about 20%, which is consistent with estimated value from initial composition. The stacked LPSO disks were distributed along 3D network. It is suggested that this 3D structure is concerned with the distribution of Mg3Gd compounds observed in as-cast specimens.jmicro;63/suppl_1/i25-a/DFU068F1F1DFU068F1Fig. 1.(a) SEM image of the Mg89.5Zn4.5Gd6 alloy aged at 753 K for 2h. (b) 3D representation of the tomographic reconstruction from SEM images. The soiled parts of the 3D volume are 14 H LPSO phase.
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PMID:Multi-scale 3D characterization of long period stacking ordered structure in Mg-Zn-Gd cast alloys. 2535 23