3,279 research outputs found
Separation and purification of curcumin preparation of morphology controlled micro particles
Curcumin was extracted from turmeric plants which is the most commonly used natural pigments, and possess a variety of pharmacological functions except for using pigment. The morphology and particle size of curcumin are main factors affecting the application. Therefore, the morphology and particle size distribution of curcumin were effectively controlled by advanced technology, which is significant for expanding the application and added value of curcumin. The curcumin crystal was obtained from curcumin pigments by using column chromatography and recrystallization techniques. The composition and structure of curcumin were characterized by elementary analysis, UV-Vis, IR and NMR. Micronization of curcumin was carried out the Solution Enhanced Dispersion by Supercritical Fluids (SEDS) technology. In the process, supercritical carbon dioxide was used as anti-solvent and acetone/dichloromethane (1:4, v:v) was used as solvent. The curcumin crystals with PSs of about 378 μm were successfully micronized by the SEDS process to micro particles with PSs of about 2.6-10 μm. The acicular, leaves, dendritic and tubular micro particles were obtained through controlling parameters such as pressure, temperature, solution concentration and solution flow rate.DOI: http://doi.dx.org/10.5564/mjc.v15i0.314 Mongolian Journal of Chemistry 15 (41), 2014, p11-1
Establishment of a normal medakafish spermatogonial cell line capable of sperm production in vitro
Spermatogonia are the male germ stem cells that continuously produce sperm for the next generation. Spermatogenesis is a complicated process that proceeds through mitotic phase of stem cell renewal and differentiation, meiotic phase, and postmeiotic phase of spermiogenesis. Full recapitulation of spermatogenesis in vitro has been impossible, as generation of normal spermatogonial stem cell lines without immortalization and production of motile sperm from these cells after long-term culture have not been achieved. Here we report the derivation of a normal spermatogonial cell line from a mature medakafish testis without immortalization. After 140 passages during 2 years of culture, this cell line retains stable but growth factor-dependent proliferation, a diploid karyotype, and the phenotype and gene expression pattern of spermatogonial stem cells. Furthermore, we show that this cell line can undergo meiosis and spermiogenesis to generate motile sperm. Therefore, the ability of continuous proliferation and sperm production in culture is an intrinsic property of medaka spermatogonial stem cells, and immortalization apparently is not necessary to derive male germ cell cultures. Our findings and cell line will offer a unique opportunity to study and recapitulate spermatogenesis in vitro and to develop approaches for germ-line transmission.Spermatogonia are the male germ stem cells that continuously produce sperm for the next generation. Spermatogenesis is a complicated process that proceeds through mitotic phase of stem cell renewal and differentiation, meiotic phase, and postmeiotic phase of spermiogenesis. Full recapitulation of spermatogenesis in vitro has been impossible, as generation of normal spermatogonial stem cell lines without immortalization and production of motile sperm from these cells after long-term culture have not been achieved. Here we report the derivation of a normal spermatogonial cell line from a mature medakafish testis without immortalization. After 140 passages during 2 years of culture, this cell line retains stable but growth factor-dependent proliferation, a diploid karyotype, and the phenotype and gene expression pattern of spermatogonial stem cells. Furthermore, we show that this cell line can undergo meiosis and spermiogenesis to generate motile sperm. Therefore, the ability of continuous proliferation and sperm production in culture is an intrinsic property of medaka spermatogonial stem cells, and immortalization apparently is not necessary to derive male germ cell cultures. Our findings and cell line will offer a unique opportunity to study and recapitulate spermatogenesis in vitro and to develop approaches for germ-line transmission
OUTLINE OF GRANITOIDS OF THE CENTRAL ASIA OROGENIC BELT: FOCUSED ON THE SOUTHERN PART
the Siberian craton to the north and the TarimNorth China cratons to the south, is a complex collage of microcontinental blocks, island arcs, oceanic crustal remnants and continental marginal facies rocks. It is one of the largest and most complex accretionary orogenic belts and the most important site of Phanerozoic continental growth on the Earth [Jahn et al., 2000, 2004; Kovalenko et al., 2004] The widespread occurrence of large volumes of granitoids, mostly with juvenile sources, is a typical characteristic of the CAOB. These granitoids have been intensely studied (e.g. [Jahn et al., 2000, 2004; Kovalenko et al., 2004; Sorokin et al., 2004; Vladimirov et al., 2001; Han et al., 2010; Wang et al., 2006, 2015; Wu et al., 2011; Li et al., 2013; Yarmolyuk et al., 2002]). However, these studies mainly focused on some certain countries or regions.The Central Asian Orogenic Belt (CAOB), bounded by the Siberian craton to the north and the TarimNorth China cratons to the south, is a complex collage of microcontinental blocks, island arcs, oceanic crustal remnants and continental marginal facies rocks. It is one of the largest and most complex accretionary orogenic belts and the most important site of Phanerozoic continental growth on the Earth [Jahn et al., 2000, 2004; Kovalenko et al., 2004] The widespread occurrence of large volumes of granitoids, mostly with juvenile sources, is a typical characteristic of the CAOB. These granitoids have been intensely studied (e.g. [Jahn et al., 2000, 2004; Kovalenko et al., 2004; Sorokin et al., 2004; Vladimirov et al., 2001; Han et al., 2010; Wang et al., 2006, 2015; Wu et al., 2011; Li et al., 2013; Yarmolyuk et al., 2002]). However, these studies mainly focused on some certain countries or regions
Quantum-inspired interferometry with chirped laser pulses
We introduce and implement an interferometric technique based on chirped
femtosecond laser pulses and nonlinear optics. The interference manifests as a
high-visibility (> 85%) phase-insensitive dip in the intensity of an optical
beam when the two interferometer arms are equal to within the coherence length
of the light. This signature is unique in classical interferometry, but is a
direct analogue to Hong-Ou-Mandel quantum interference. Our technique exhibits
all the metrological advantages of the quantum interferometer, but with signals
at least 10^7 times greater. In particular we demonstrate enhanced resolution,
robustness against loss, and automatic dispersion cancellation. Our
interferometer offers significant advantages over previous technologies, both
quantum and classical, in precision time delay measurements and biomedical
imaging.Comment: 6 pages, 4 figure
Trapped lipopolysaccharide and LptD intermediates reveal lipopolysaccharide translocation steps across the Escherichia coli outer membrane
Lipopolysaccharide (LPS) is a main component of the outer membrane of Gram-negative bacteria, which is essential for the vitality of most Gram-negative bacteria and plays a critical role for drug resistance. LptD/E complex forms a N-terminal LPS transport slide, a hydrophobic intramembrane hole and the hydrophilic channel of the barrel, for LPS transport, lipid A insertion and core oligosaccharide and O-antigen polysaccharide translocation, respectively. However, there is no direct evidence to confirm that LptD/E transports LPS from the periplasm to the external leaflet of the outer membrane. By replacing LptD residues with an unnatural amino acid p-benzoyl-L-phenyalanine (pBPA) and UV-photo-cross-linking in E.coli, the translocon and LPS intermediates were obtained at the N-terminal domain, the intramembrane hole, the lumenal gate, the lumen of LptD channel, and the extracellular loop 1 and 4, providing the first direct evidence and “snapshots” to reveal LPS translocation steps across the outer membrane
Properties of Light Flavour Baryons in Hypercentral quark model
The light flavour baryons are studied within the quark model using the hyper
central description of the three-body system. The confinement potential is
assumed as hypercentral coulomb plus power potential () with power
index . The masses and magnetic moments of light flavour baryons are
computed for different power index, starting from 0.5 to 1.5. The
predicted masses and magnetic moments are found to attain a saturated value
with respect to variation in beyond the power index 1.0. Further
we computed transition magnetic moments and radiative decay width of light
flavour baryons. The results are in good agreement with known experimental as
well as other theoretical models.Comment: Accepted in Pramana J. of Physic
Pion and Vector Meson Form Factors in the Kuperstein-Sonnenschein holographic model
We study phenomenological aspects of the holographic model of chiral symmetry
breaking recently introduced by Kuperstein and Sonnenschein (KS). As a first
step, we calculate the spectrum of vector and axial-vector mesons in the KS
model. We numerically compute various coupling constants of the mesons and
pions. Our analysis indicates that vector meson dominance is realized in this
model. The pion, vector meson and axial-vector meson form factors are obtained
and studied in detail. We find good agreement with QCD results. In particular,
the pion form factor closely matches available experimental data.Comment: v1: 27 pages, 9 figures, 4 tables; v2: minor changes, added more
general discussion of vector meson dominance; v3: minor changes and
additions, version accepted for publication in JHE
Paediatric obsessive-compulsive disorder and depressive symptoms: clinical correlates and CBT treatment outcomes.
Depression frequently co-occurs with paediatric obsessive-compulsive disorder (OCD), yet the clinical correlates and impact of depression on CBT outcomes remain unclear. The prevalence and clinical correlates of depression were examined in a paediatric specialist OCD-clinic sample (N = 295; Mean = 15 [7 - 18] years, 42 % female), using both dimensional (Beck Depression Inventory-youth; n = 261) and diagnostic (Development and Wellbeing Assessment; n = 127) measures of depression. The impact of depressive symptoms and suspected disorders on post-treatment OCD severity was examined in a sub-sample who received CBT, with or without SSRI medication (N = 100). Fifty-one per-cent of patients reported moderately or extremely elevated depressive symptoms and 26 % (95 % CI: 18 - 34) met criteria for a suspected depressive disorder. Depressive symptoms and depressive disorders were associated with worse OCD symptom severity and global functioning prior to CBT. Individuals with depression were more likely to be female, have had a psychiatric inpatient admission and less likely to be attending school (ps < 0.01). OCD and depressive symptom severity significantly decreased after CBT. Depressive symptoms and depressive disorders predicted worse post-treatment OCD severity (βs = 0.19 and 0.26, ps < 0.05) but became non-significant when controlling for pre-treatment OCD severity (βs = 0.05 and 0.13, ns). Depression is common in paediatric OCD and is associated with more severe OCD and poorer functioning. However, depression severity decreases over the course of CBT for OCD and is not independently associated with worse outcomes, supporting the recommendation for treatment as usual in the presence of depressive symptoms
Shugoshin1 May Play Important Roles in Separation of Homologous Chromosomes and Sister Chromatids during Mouse Oocyte Meiosis
Background: Homologous chromosomes separate in meiosis I and sister chromatids separate in meiosis II, generating haploid gametes. To address the question why sister chromatids do not separate in meiosis I, we explored the roles of Shogoshin1 (Sgo1) in chromosome separation during oocyte meiosis. Methodology/Principal Findings: Sgo1 function was evaluated by exogenous overexpression to enhance its roles and RNAi to suppress its roles during two meioses of mouse oocytes. Immunocytochemistry and chromosome spread were used to evaluate phenotypes. The exogenous Sgo1 overexpression kept homologous chromosomes and sister chromatids not to separate in meiosis I and meiosis II, respectively, while the Sgo1 RNAi promoted premature separation of sister chromatids. Conclusions: Our results reveal that prevention of premature separation of sister chromatids in meiosis I requires th
Ionic Transport Properties in Nanocrystalline Ce0.8A0.2O2-δ (with A = Eu, Gd, Dy, and Ho) Materials
The ionic transport properties of nanocrystalline 20 mol% Eu, Gd, Dy, and Ho doped cerias, with average grain size of around 14 nm were studied by correlating electrical, dielectric properties, and various dynamic parameters. Gd-doped nanocrystalline ceria shows higher value of conductivity (i.e., 1.8 × 10−4 S cm−1 at 550°C) and a lower value of association energy of oxygen vacancies with trivalent dopants Gd3+ (i.e., 0.1 eV), compared to others. Mainly the lattice parameters and dielectric constants (ε∞) are found to control the association energy of oxygen vacancies in these nanomaterials, which in turn resulted in the presence of grain and grain boundary conductivity in Gd- and Eu-doped cerias and only significant grain interior conductivity in Dy- and Ho-doped cerias
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