Academic literature on the topic 'Steroid crystals'
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Journal articles on the topic "Steroid crystals"
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Wolf, Steven M., Zachary M. Marsh, Steven M. Quarin, Kyung Min Lee, Sushma Karra, Michael E. McConney, Tod A. Grusenmeyer, and Nicholas P. Godman. "Investigating the Electro-Optic Response of Steroid Doped Liquid Crystal Devices." Applied Sciences 13, no. 8 (April 18, 2023): 5054. http://dx.doi.org/10.3390/app13085054.
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Nature is highly efficient at producing chiral compounds that are enantiomerically pure. The inherent chirality of naturally occurring biomolecules means that many have the potential to be used as chiral dopants for cholesteric liquid crystal (CLC) systems. Though many biomolecules have been identified as chiral dopants, many remain yet to be probed for their ability to function as chiral dopants. Here, 10 naturally occurring biomolecules comprised of steroids and bile acids were tested as chiral dopants for CLCs. Progesterone was identified as having high miscibility with nematic liquid crystals and was used in responsive liquid crystal devices. Progesterone-doped CLC devices were fabricated to exhibit either normal mode or reverse mode switchable behavior. Polymer stabilized CLCs (PSCLC) devices exhibiting dynamic electro-optic red- and blue-tuning behaviors were also fabricated. Furthermore, immiscible lithocholic acid was synthetically modified to afford two derivatives that were miscible at 10 wt. % in nematic liquid crystals. The two lithocholic acid derivatives were used as chiral dopants and incorporated into polymer stabilized CLCs which exhibited blue tuning behavior.
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Bhadu, D., S. Vyas, and U. Kumar. "THU0415 MELTING OF TOPHI WITH LOCAL STEROIDS IN CHRONIC TOPHACEOUS GOUT: AN OBSERVATIONAL STUDY." Annals of the Rheumatic Diseases 79, Suppl 1 (June 2020): 445. http://dx.doi.org/10.1136/annrheumdis-2020-eular.2918.
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Background:Chronic tophaceous gout is usually difficult to treat with urate lowering therapy (ULT) [1]. Faster resolution of tophi has been seen with use of pegloticase [2], but this drug is costly and not widely available. Local steroid use is recommended in acute gouty arthritis but its role in reduction of tophi has not been studied. This study was aimed to see the effect of local steroids in tophi resolution.Objectives:To study the change in size of gouty tophi with local steroid injection compared to conventional treatment.Methods:Four crystal proven chronic tophaceous gout patients with multiple tophi were screened and enrolled in the study after taking informed consent. Total 12 tophi in 4 patients were imaged by using Duel Energy Computed Scan (DECT) for their size and volume. All 4 patients were treated with ULT as per recommended dose to achieve target serum uric acid (SUV) level. Six tophi were treated with local steroids injection (methylprednisolone acetate) at two months interval till complete resolution of tophi. Dose of steroid varied from 10 mg to 40 mg depending upon tophi size but subsequent repeat doses were same in each tophi. Six tophi not treated with local steroid served as internal control in the same patients. All 4 patients were followed up regularly in out-patient department to monitor treatment response and local side effects if any.Results:All 4 patients achieved target SUV (<356 µmol/L) at three months of follow up. Six tophi which were treated with local steroids injection clinically had marked reduction in size at 7-12 months of follow up [Table-1], while other 6 tophi which served as internal control had no clinically significant change in size and volume of tophi. DECT was repeated in the same settings to confirm the clinical findings. DECT revealed near complete resolution of 5 tophi [Image-1], and 50% reduction in size of one tophi. Six tophi which were not treated with local steroid had no significant reduction in size in DECT as well. Only side effect noted was skin discoloration in 5 out of 6 injected sites, none of the tophi had infection.Conclusion:Interestingly this is the first such study to document the use of local steroid in tophi. Thus intralesional steroids can be alternative to pegloticase or surgery where faster dissolution of tophi is required. This observation needs to be explored in large number of patients to calculate the total dose requirement of steroid as per volume and urate burden of tophi. Possible explanation of melting tophi with steroids is breaking down outer fibrous layer of tophi by local steroids which might be acting as barrier in dissolution of urate crystals with ULT.References:[1]Dalbeth N, House ME, Horne A et al. Prescription and dosing of urate-lowering therapy, rather than patient behaviours, are the key modifiable factors associated with targeting serum urate in gout.BMC Musculoskelet Disord2012;13:174[2]Baraf HS, Becker MA, Gutierrez-Urena SR, et al: Tophus burden reduction with pegloticase: results from phase 3 randomized trials and open-label extension in patients with chronic gout refractory to conventional therapy. Arthritis Res Ther 15:R137, 2013Table 1.Age/sexTotal TophiTreated TophiOutcome of treated tophiInternal control tophiDuration in monthsCase 122/M21Near complete resolutionNo Change 7Case 245/F11Complete resolutionNA 8Case 358/M52Near complete resolutionNo change12Case 424/M42Completely resolved=1,50% size reduction=1No change12Figure 1a: DECT of Rt foot shows urate crystal deposition at 1stMTP joint and 5thtoe. Figure1b: DECT after 7 months of steroid injection in Rt 1stMTP joint tophi shows almost complete resolution but no change in 5thtoe tophi (served as internal control).Disclosure of Interests: :None declared
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Frampton, Christopher S., and David D. MacNicol. "Structure of Equilenin at 100 K: an estrone-related steroid." Acta Crystallographica Section E Crystallographic Communications 73, no. 8 (July 21, 2017): 1223–26. http://dx.doi.org/10.1107/s2056989017010532.
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The structure of the estrone-related steroid, Equilenin, C18H18O2 (systematic name 3-hydroxy-13-methyl-11,12,13,14,15,16-hexahydrocyclopenta[a]phenanthren-17-one), has been determined at 100 K. The crystals are orthorhombic, P212121, and the absolute structure of the molecule in the crystal has been determined by resonant scattering [Flack parameter = −0.05 (4)]. The C atoms of the A and B rings are almost coplanar, with an r.m.s. deviation from planarity of 0.0104 Å. The C ring has a sofa conformation, while the D ring has an envelope conformation with the methine C atom as the flap. The keto O atom and the methyl group are translated 0.78 and 0.79 Å, respectively, from the equivalent positions on 17β-estrone. In the crystal, molecules are linked by O—H...O hydrogen bonds, forming chains parallel to the c-axis direction.
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Fábián, László, Gyula Argay, Alajos Kálmán, and Mária Báthori. "Crystal structures of ecdysteroids: the role of solvent molecules in hydrogen bonding and isostructurality." Acta Crystallographica Section B Structural Science 58, no. 4 (July 30, 2002): 710–20. http://dx.doi.org/10.1107/s0108768102005608.
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Three crystal forms of the steroid 20-hydroxyecdysone were identified by single-crystal X-ray diffraction analysis: a solvent-free modification, a methanol solvate hydrate and a trihydrate. The structure of a closely related steroid, polypodine B (the 5,20-dihydroxy derivative of ecdysone), was determined in its monohydrate form. Since the unit-cell volume of unsolvated 20-hydroxyecdysone was found to be considerably smaller than that of ecdysone [Huber & Hoppe (1965). Chem. Ber. 98, 2403–2424], a new structure determination of ecdysone was performed, which confirmed the unexpected difference between the unit-cell volumes. The crystals of ecdysone and 20-hydroxyecdysone are isostructural, while the mixed solvate of 20-hydroxyecdysone is homostructural with the hydrate of polypodine B. A detailed analysis of the hydrogen-bond networks in these closely related crystal pairs highlights their packing similarities, demonstrates the role of solvent molecules, and explains the unexpectedly small cell volume of 20-hydroxyecdysone.
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Grishkovskaya, Irina, Gisela Sklenar, George V. Avvakumov, David Dales, Joachim Behlke, Geoffrey L. Hammond, and Yves A. Muller. "Crystallization of the N-terminal domain of human sex hormone-binding globulin, the major sex steroid carrier in blood." Acta Crystallographica Section D Biological Crystallography 55, no. 12 (December 1, 1999): 2053–55. http://dx.doi.org/10.1107/s0907444999012883.
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The amino-teminal laminin G-like domain of human sex hormone-binding globulin (SHBG), which contains the steroid-binding site and the dimerization domain, has been produced in Escherichia coli, purified to homogeneity and crystallized in complex with 5α-dihydrotestosterone (DHT) in two different crystal forms. Native data sets have been collected for tetragonal crystals (space group P4122 or P4322; unit-cell parameters a = 52.2, c = 148.4 Å) diffracting to 3.3 Å and trigonal crystals (R32; a = 104.0, c = 84.4 Å) diffracting to better than 1.6 Å. Since both crystal forms can only accommodate a single monomer in the asymmetric unit and share twofold rotational symmetry, it is proposed that the homodimer of this truncated form of SHBG, as observed in ultracentrifugation experiments, displays C 2 point-group symmetry.
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Rychlewska, Urszula, Beata Warżajtis, Roman Joachimiak, and Zdzisław Paryzek. "Synthesis and structural characteristics of lithocholate triads: steroid-type channels occupied by spacer fragments." Acta Crystallographica Section B Structural Science 64, no. 3 (May 15, 2008): 383–92. http://dx.doi.org/10.1107/s0108768108006514.
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Reported in this paper are the syntheses and X-ray investigations of C 2 symmetrical molecular A—B—A triads consisting of two steroid units (lithocholic acid or its methyl ester) joined together by linkers derived from bifunctional molecules such as terephthalic acid or N,N′-dicarboxypiperazine. Unlike their monomeric analogues, some of these compounds form inclusion complexes. All steroidal triads form crystals that are highly pseudo-centrosymmetric, in which the constituting molecules are held together either exclusively by van der Waals forces or form lattice inclusion complexes, with guest molecules hydrogen bonded to the host. The presence of carboxyl groups promotes the inclusion of pyridine molecules and the formation of the well known carboxylic acid...pyridine hydrogen bonds. Combined with pairwise face-to-face π-stacking between pyridine rings, these hydrogen-bond interactions lead to the formation of extended supramolecular tapes, analogous to polymers. The co-crystals of pyridine and a lithocholic acid triad undergo a symmetry-lowering phase transition from a P1 cell with Z = 1 to a P1 cell with Z = 2. The two structures are virtually the same, the two independent molecules in the larger cell being related by pseudo-translation. Changes in the type of spacer between two methyl lithocholate units from planar aromatic (terephthalic acid) to highly puckered aliphatic six-membered ring (N,N′-dicarboxypiperazine) bring about inclusion properties and changes in side-chain conformation in a crystal. Although the efficient packing of these highly elongated molecules is hindered, as indicated by low values of crystal density, ranging from 1.16 to 1.19 g cm−3, several very short C...O and H...H contacts are present in the crystals.
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Tsoi, Kevin, and Rod Hughes. "An unusual case of steroid responsive idiopathic ectopic calcification." Oxford Medical Case Reports 2019, no. 11 (November 1, 2019): 466–68. http://dx.doi.org/10.1093/omcr/omz108.
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Abstract This case explores an unusual calcified lesion of the hand and its dramatic response to steroids. A 30-year-old lady presented to rheumatology with a 1-year history of swelling on the radial side of her right middle metacarpophalangeal joint. Over a 2-week period, she had developed swelling throughout her right hand. She was treated with intramuscular methylprednisolone injection and a weaning course of prednisolone. A series of photos and X-rays demonstrates the resolution of swelling and calcification after steroid treatment. This case reports a chronic calcified mass associated with an acute inflammatory episode in the hand. This is likely to represent rupture of a calcific deposit with the release of crystals into the soft tissue. While there is prior literature on treatment with bisphosphonates or surgery, a fast and complete response to modest dose steroids suggests that this would be the first treatment to try in such a case.
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Turza, Alexandru, Maria O. Miclăuș, Aurel Pop, and Gheorghe Borodi. "Crystal and molecular structures of boldenone and four boldenone steroid esters." Zeitschrift für Kristallographie - Crystalline Materials 234, no. 10 (October 25, 2019): 671–83. http://dx.doi.org/10.1515/zkri-2019-0030.
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Abstract Androsta-1,4-dien-17β-ol-3-one, also known as boldenone, is an anabolic-androgenic steroid derived from testosterone. The crystal structures of boldenone base, boldenone acetate, boldenone propionate, boldenone cypionate and a boldenone acetate polymorph obtained by high throughput screening were investigated. Hirshfeld surfaces and fingerprint plots breakdown revealed that the molecular packing in the crystals are driven by dominant H⋯H intermolecular contacts, followed by O⋯H/H⋯O contacts and to a lesser degree C⋯H/H⋯C contacts. The steroid skeleton rings, for all the reported compounds, adopt the following conformation: planar in A, chair in B and C, whereas C(13) envelope conformations are found for the five-membered D rings. The total lattice energies were calculated as a sum of four terms (Coulombic, polarization, dispersion, repulsion).
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Sara, Katti Blessi, Rajan Sundaresan Vediappan, J. Prabaakharan, and Regi Thomas. "Primary Radical Extended Sinus Surgery for Management of Extensive Allergic Fungal Rhinosinusitis." Current Medical Issues 22, no. 3 (June 26, 2024): 158–63. http://dx.doi.org/10.4103/cmi.cmi_3_24.
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Introduction: Allergic fungal rhinosinusitis (AFRS), a subset of sinusitis secondary to hypersensitivity, is clinically similar to chronic rhinosinusitis with nasal polyp but histologically different with rich eosinophils and Charcot Leyden crystals. Since the primary pathology in AFRS is immune mediated, the recurrence rates are high. In this study, we describe the application of radical extended sinus surgery (RESS) as the surgical technique with the usage of postoperative high-volume steroidal nasal irrigation and short-term oral steroid therapy – a threefold strategy – for the prevention of recurrence of this disease. Materials and Methods: A retrospective surgical chart audit of patients diagnosed with AFRS and treated between January 2012 and December 2019 was done. The clinical findings and postoperative outcomes performed by a single senior surgeon in a tertiary referral institution were extracted and analyzed. Results: Of the 17 patients, 88% of patients were immunocompetent and Lund Mackay (LM) of 24, 16 patients had Grade 3 nasal polyps, except one with Grade 1 nasal polyps and an LM score of 8. All patients underwent RESS and received postoperative high-volume topical steroid irrigation with oral steroids in the immediate postoperative period and on follow-up, if recurrence was noted, none required revision surgery. Conclusions: A three-fold strategy is beneficial in the management of AFRS-RESS followed by oral steroids during the immediate postoperative period along with long-term topical high-volume steroid nasal irrigation.
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Vicatos, Alexios I., Zakiena Hoossen, and Mino R. Caira. "Inclusion complexes of the steroid hormones 17β-estradiol and progesterone with β- and γ-cyclodextrin hosts: syntheses, X-ray structures, thermal analyses and API solubility enhancements." Beilstein Journal of Organic Chemistry 18 (December 22, 2022): 1749–62. http://dx.doi.org/10.3762/bjoc.18.184.
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Overcoming the challenges of poor aqueous solubility of active pharmaceutical ingredients (APIs) is necessary to render them bioavailable. This study addresses the poor solubility of two potent steroid hormones, 17β-estradiol (BES) and progesterone (PRO), via their complexation with two water-soluble native cyclodextrins (CDs) namely β-CD and γ-CD. The hydrated inclusion complexes β-CD·BES, β-CD·PRO, γ-CD·BES and γ-CD·PRO were prepared via kneading and co-precipitation, and 1H NMR spectroscopic analysis of solutions of their pure complex crystals yielded the host–guest stoichiometries 2:1, 2:1, 1:1 and 3:2, respectively. Both powder X-ray diffraction (PXRD) and single-crystal X-ray diffraction (SCXRD) were employed for focused studies of the isostructurality of the CD complexes with known complexes and structural elucidation of the new complexes, respectively. SCXRD analyses of β-CD·BES, β-CD·PRO and γ-CD·PRO at 100(2) K yielded the first crystal structures of CD complexes containing the hormones BES and PRO, while the complex γ-CD·BES was readily shown to be isostructural with γ-CD·PRO by PXRD. Severe disorder of the encapsulated steroid molecules in the respective channels of the CD molecular assemblies was evident, however, preventing their modelling, but combination of the host–guest stoichiometries and water contents of the four hydrated inclusion complexes enabled accurate assignment of the chemical formulae of these ternary systems. Predicted electron counts for the complexed molecules BES and PRO correlated reasonably well with the complex compositions indicated by 1H NMR spectroscopy. Subsequent measurements of the aqueous solubilities of the four complexes confirmed significant solubility improvements effected by encapsulation of the steroids within the CDs, yielding solubility enhancement factors for BES and PRO in the approximate range 5–20.
Dissertations / Theses on the topic "Steroid crystals"
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Harwood, Simon M. "Novel chiral thermochromic mesogens derived from cholest-5-en-3#beta#-ol and related systems." Thesis, University of Hull, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.327294.
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Bridgland, Lydia Naomi. "Crystal engineering of porous steroidal organic crystals." Thesis, University of Bristol, 2013. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.627972.
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Porous materials are highly valued for a wide variety of scientific and technological applications and organic molecular crystals offer an alternative to established inorganic materials. In this thesis, the porosity of tris-N-phenylureido steroidal crystals IS characterised and the versatility of the steroidal crystal system is demonstrated. Material properties can often be adjusted by mixing components in varying proportions to form alloys, but this phenomenon is rarely demonstrated for organic molecules. In organic crystals, molecules pack into an array which has symmetry and dimensions specific to the compound. Thus, in general, molecules cannot be substituted for molecules of a different compound. The studies presented here demonstrate that organic alloys are possible if the crystal structure possesses voids which are able to accommodate significant p0l1ions of the new molecules. A variety of multi-component steroidal crystals have been created with diverse and complex channel interiors. These have been characterised by optical microscopy, single X-ray crystallography, IH NMR and mass spectrometry. Finally, molecular machines which perform mechanical work on a molecular level are of great interest within the scientific community. The operational range of molecular motion is often too restricted to create macroscopic phenomena, but by confining the molecular machines to small spaces such as nanopores, molecular movement on the nanometre level can be sufficient to dominate the physical and chemical behaviour of guest molecules. In this thesis, the prospect of creating a new type of molecular machine assembly to propel molecules unidirectionally along crystal channels has been investigated. Crystal engineering has been used to design porous steroidal crystals with azobenzene moieties, capable of photoinduced isomerisation, protruding into the crystal channels. The resulting crystals have been analysed by optical microscopy and solid-state UV-vis spectroscopy, and the distribution of guest molecules within the crystals has been investigated by Raman and IR microspectroscopy and fluorescence microscopy.
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Zonglong, Yang. "Auto-organisation des Acyl Steroid Glycosides (ASG) : Etude des relations structure-propriétés pour les cas de l’α-CAG et du BbGL 1, constituants de membranes bactériennes." Thesis, Lyon, 2018. http://www.theses.fr/2018LYSEI041.
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Les acyl stéryl glycosides (ASGs) appartiennent à une famille de glycolipides qui possèdent un caractère amphiphile particulier dû à la présence de deux parties hydrophobes, un stéroïde et une chaine grasse. Dans le cadre de nos études des propriétés d’auto-organisation des glycoamphiphiles, ce travail est dédié à l’étude de deux ASGs, α-CAG et BbGL 1, composés naturels présents respectivement dans les membranes des bactéries Helicobacter pylori et Borrelia burgdorferi., présentant des structures similaires mais des activités biologiques différentes. Notre travail a consisté à déterminer les paramètres structuraux qui gouvernent leurs propriétés d’auto-assemblage. Deux séries de 6-O-acyl cholestéryl glycosides (glucosides et galactosides) variant dans leur configuration anomérique et la longueur et le niveau d’insaturation de leur chaine grasse ont été synthétisées et leur capacité à former des cristaux liquides et à promouvoir une ségrégation lipidique dans des monocouches de Langmuir modèles de membrane ont été étudiées. Les relations structure-propriétés établies montrent que la longueur de la chaine grasse est le paramètre le plus discriminant dans le comportement d’auto-assemblage dans les deux types d’expériences. Pour les cristaux liquides thermotropes, l’autre facteur discriminant est la configuration anomérique, deux phases colonnaires successives rectangulaires puis hexagonales étant observées pour les séries α alors qu’une seule a été observée en séries β Changer de sucre n’induit pas de différence significative dans le comportement LC. Concernant la formation de domaines lipidiques, les modifications de la configuration (α/β) et du sucre influencent significativement leur temps d’apparition, apportant pour la première fois une définition claire des paramètres structuraux et physicochimiques qui gouvernent le comportement de l’α-CAG et ses analogues, en lien avec les données commues sur l’augmentation de pathogénicité d’Helicobacter pylori. Ce travail de thèse donne une illustration de l’importance de la structure des carbohydrates dans les processus biologiques et du concept de glycoamphiphilieAcyl steryl glycosides (ASGs) are a family of glycolipids which exhibit a peculiar amphiphilic character based on the presence of two hydrophobic appendages, one steroid moiety and one fatty alkyl chain, attached on a polar carbohydrate backbone. In the frame of our studies on the self-organisation properties of carbohydrate-based amphiphiles, this thesis is an investigation of the behavior of ASGs, in particular α-CAG and BbGL 1, two natural compounds found in bacterial membranes, Helicobacter pylori, Borrelia burgdorferi repectively, who exhibit close structures but different bioactivity. Our work has aimed at determining the key structural parameters governing their self-organization behavior. Two series of acyl cholesteryl glycosides (glucosides or galactosides) have been synthesized, with variations in the anomeric configuration, the 6-O-acyl chain length and level of unsaturation, and investigated with respect to their ability to form liquid crystalline mesophases, and to drive lipid domain segregation in Langmuir monolayers as model membranes. Structure-properties relationships have been established, indicating that the fatty chain length showed the most remarkable influence on the self-organization behavior, in LC and model membrane experiments. For the LC mesophases, the other important parameter is the anomeric configuration, two successive columnar phases, rectangular then hexagonal, being observed for the α-anomers, whereas only one was found for the β-anomers. No significant changes were observed when comparing glucosides and galactosides. With respect the formation of domains, configuration modifications at both C-1 (α or β) and C-4 (gluco or galacto) influenced significantly the domains appearance time, giving the first, clear physicochemical proof of the structural influential factors in the behavior of α-CAG and analogues, in the context of the known increased pathogenicity of Helicobacter pylori. Overall, this thesis provides a nice illustration of the subtlety and the importance of carbohydrate structure in biological processes, and of the concept of glycoamphiphilicity
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Xu, Rui. "On the role of the carbohydrate vs the lipid moieties in neoglycolipid self-organisation : Synthesis and liquid crystalline properties of two new families of carbohydrate-based amphiphiles." Phd thesis, INSA de Lyon, 2013. http://tel.archives-ouvertes.fr/tel-00940381.
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In this study, we have synthesized two families of new carbohydrate-based amphiphilic derivatives: a series of alkyl glucoside ethers varying in terms of chain length and position on the sugar, and a series of glucosteroids varying in terms of alkyl spacer and, for the disutibstuted systems, in terms of alkyl side chain length. By the means of analytical methods, such as NMR spectroscopy, mass spectroscopy and elementary analysis, the structure of all the compounds was carefully established, as well as their purity. Their liquid crystalline behaviors were studied by the means of transmission light microscopy and differential scanning calorimetry. The two families of compounds which have been studied illustrate how much the behavior can be essentially related to polar interactions (H-bonding), therefore to the sugar moiety, for the ether series, or to hydrophobic interactions (lipid-lipid) in the glucosteroid series. In this latter series, preference for either steroid-stroid or steroid alkyl packing appears as an insight in understanding the behavior of complex lipids, showing potentially more than one conformational structure with important consequences on the supramolecular level, therefore to their potential biological role. This could be regarded as "lipid denaturation" by analogy to the protein denaturation. Also, when we see that compounds like the glycosteroids having an long chain ester -CAG, BbGL-I, are found to exist in Nature, and how much glycolipid-cholesterol interactions were recently shown to be critical in some biological processes, it is hoped that our observations can provide a new vision angle for the study of complex lipids and glycolipids. As a start to develop new probes targeting the "lipid raft" microdomain in membranes, we also explored a sequence towards carbohydrate laurdan hybrids. Further development of this strategy and evaluation of the biological properties is programmed within new collaborative projects.
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Zghebi, Salwa S. "Crystal engineering, Bio Pharmaceutics and Cell biology of active pharmaceutical ingredient (drug) nanoparticles. Formation and cell interaction of hydrocortisone and prednisolone nanoparticles." Thesis, University of Bradford, 2010. http://hdl.handle.net/10454/5183.
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Nanotechnology applications have emerged enormously in recent times. Of particular interest is that area that overlaps the areas of nanotechnology, biology and medicine: nanomedicine. One advantage of nanomedicines is it that it can be used as an enabling technology by pharmaceutical researchers and industry to overcome issues associated with the low bioavailability of hydrophobic drugs. In the first part of the current study, nanosuspensions of two of hydrophobic steroid drugs: hydrocortisone and prednisolone were produced. Nanosuspensions were prepared using a bottom-up approach: the anti-solvent precipitation method using microfluidic reactors. Surface modification was carried out on these nanosuspensions using cationic surfactants to obtain nanoparticles with different levels of surface positive charge as indicated by ¿-potential values. Dynamic light scattering (DLS) and transmission electron microscope (TEM) techniques were used to characterize the prepared nanoparticles. Powder X-ray diffraction (PXRD) and differential scanning calorimetry (DSC) were also used to characterize hydrocortisone nanoparticles. In the second part, cellular uptake of both coated and uncoated nanoparticles by HaCaT keratinocytes cell line was examined and indicated by quantifying the anti- inflammatory effect of nanoparticles on the LPS-induced inflammation. Also, TEM was employed to evaluate the cellular uptake of hydrocortisone nanoparticles. Results showed higher ant-inflammatory effect of coated nanoparticles over uncoated nanoparticles. Furthermore, the anti-inflammatory effect of coated nanoparticles was correlated to the degree of positive surface charge.Libyan government
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Trebble, Peter. "Glucocorticoid receptor function : new insights from genetic and chemical biology approaches." Thesis, University of Manchester, 2013. https://www.research.manchester.ac.uk/portal/en/theses/glucocorticoid-receptor-function-new-insights-from-genetic-and-chemical-biology-approaches(b55c612b-eda1-4908-a0df-ec916f03ade2).html.
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Glucocorticoids (Gc) are vital for development, maintenance of glucose homeostasis and the resolution of inflammation. As potent modulators of the immune response Gc are routinely prescribed in the management of a variety of inflammatory diseases including asthma and rheumatoid arthritis. However clinical use of Gc is limited by variation in patient sensitivity to Gc treatment and development of a wide range of side effects. In this thesis I present two studies that have advanced our understanding of Gc action in vivo. The first defines and characterises the cause of familial glucocorticoid resistance, and the second describes the action of two potent non-steroidal Gc in a cell line model. Familial Gc Resistance: Cases of primary generalised Gc resistance are very rare and typically present as mineralocorticoid and androgen excess leading to hypertension, hypokalemia and hirsutism. Gc resistance is attributed to loss of function mutations within the glucocorticoid receptor (GR). Here I identify a family with a novel mutation in GR exon 6 that gives rise to a very mild phenotype. Analysis of transformed patient peripheral blood lymphocytes revealed a 50% reduction in full length GR but no expression of a mutant form. As this did not rule out expression in vivo, the mutant receptor (Δ612GR) was characterised in a cell line. Investigation using reporter genes revealed that Δ612GR lacked any activity, but had dominant negative action when co expressed with full length GR. In response to Gc Δ612GR was not phosphorylated or targeted for degradation. Fluorophore tagged Δ612GR was unable to translocate to the nucleus in response to Gc, but delayed the translocation of full length GR when co-expressed. Together this indicates that Δ612GR is unable to bind ligand but has dominant negative action upon full length GR most likely due to heterodimerisation. Therefore I describe a novel GR mutation that results in Gc resistance but presents with a mild very phenotype. Novel Non-steroidal Gc: Non-steroidal Gc can be used as tools to determine how ligand structure directs GR function. Here I describe two highly potent non steroidal Gc ligands, GSK47867A and GSK47869A which alter the kinetics of receptor activity. Treatment with either ligand induces slow GR nuclear translocation, promotes GR nuclear retention and prolongs transcriptional activity following ligand withdrawal. Crystal structure analysis revealed that GSK47867A and GSK47869A specifically alter the surface charge of the GR at a site important for Hsp90 binding. GR bound to GSK47867A and GSK47869A shows prolonged activity in the presence of Hsp90 inhibitor geldanamycin. Therefore this work identifies a new chemical series that could prolong GR activity due to altered pharmacodynamics rather than altered pharmacokinetics.In summary this work uses a combination of genetic and chemical biology approaches to broaden our understanding of GR function. Characterisation of naturally occurring GR mutations gives insight into the complex function of the GR, and non-steroidal Gc act as useful tools that will aid in the design of improved therapeutics.
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Halavaty, Andrei Stepanovich. "The "shuttle" mechanism of the electron transport by the ruthenium(II) bipyridyl complex-modified bovine adrenodoxin in the steroid hydroxylase crystal structure and intramolecular electron transfer /." [S.l.] : [s.n.], 2005. http://www.diss.fu-berlin.de/2005/340/index.html.
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Marie, Héléne. "Elaboration of a new sensor based on molecularly imprinted polymers for the detection of molecules in physiological fluids." Phd thesis, Université de Technologie de Compiègne, 2013. http://tel.archives-ouvertes.fr/tel-00977390.
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This thesis aimed at elaborating an optical sensor to detect molecules in a biological fluid. Two steroids and a xenobiotic were identified as biomarkers released in some body fluids: cyproterone acetate, cortisol and 2,4-dichlorophenoxyacetic acid respectively. On one hand, detection was performed by Molecularly Imprinted Polymers (MIPs). These tailor-made synthetic receptors display numerous qualities that foster their integration in sensors. MIPs were therefore developed against the targeted analytes. Formulation optimization was led thanks to experimental designs. On the other hand, optical transduction was made possible thanks to the structuring of a polymer into a photonic crystal. Opals were manufactured with a new process suitable for large scales and were used to mold MIPs in inverse opals. Thus, submicron structures of the polymer are responsible for the color of the sensor. A change of color is triggered by the recognition of the analyte by the polymer (upon swelling). Polymers studied displayed sufficient swelling observed by spectrophotometry. Finally, the work of this thesis consisted in elaborating polymer formulations and their integration in a sensor so as to detect an analyte with direct, rapid and unobtrusive means.
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Pan, Horng-Bin, and 潘鴻賓. "Steric effict of alkoxy side chain in the aryl substituted liquand on the formation of metal complex liquid crystals." Thesis, 1997. http://ndltd.ncl.edu.tw/handle/14360244444270660693.
Full textAbstract:
碩士國立臺灣大學
化學系研究所
85
Four series of (-diketonate complexes were prepared by modified process. The mesomorphiz behavior and physical properties of metal complexes were studied from the variation of metal ions, and numbers and structure of alkony side-chains in the liquid.From the experimentalresults., the following conclusions could be drawn.The number of side-chain should be six or more, the length of different side-chains in the same liquid should be similar and the metal ion should be high electron-density. The metal complexes are thermally stable, but the mesophase range is always narrow and may not be detected by DSC. Among the three types of studied, the palladium(II) complexes were found to have highest isotropic point, and oxovadium(IV) complexes the lowest. It is likely due to the strong force of coordination between molecules caused by the high electronic destiny. Polarized optical microsopy indicates four of the Pd(II) complexes and out one of Cu (II) complexes are liquid of crystal of Dhd type.To ear knowledge, this are the first complexes of metal complexliquidcrystal containing secondary alkony side-chain in the (-diketonate liquid.
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Halavaty, Andrei S. [Verfasser]. "The "shuttle" mechanism of the electron transport by the ruthenium(II) bipyridyl complex-modified bovine adrenodoxin in the steroid hydroxylase : crystal structure and intramolecular electron transfer / Andrei S. Halavaty." 2005. http://d-nb.info/978069064/34.
Full textBooks on the topic "Steroid crystals"
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Bawa, Sandeep, and Paul Wordsworth. Crystal arthropathies. Oxford University Press, 2011. http://dx.doi.org/10.1093/med/9780199550647.003.010003.
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♦ Always exclude infection in acute hot joint♦ Raised serum uric acid does not necessarily confirm a diagnosis of gout♦ Aspiration and microscopy is essential for accurate diagnosis of crystal arthropathies♦ Non-steroidal anti-inflammatory drugs and intra-articular steroids are the treatments of choice♦ Wait 2 weeks for acute gout to settle before starting hypouricaemic therapy♦ Aim for target urate of <300µmol/L.
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Roddy, Edward, and Michael Doherty. Calcium pyrophosphate crystal deposition (CPPD). Oxford University Press, 2013. http://dx.doi.org/10.1093/med/9780199642489.003.0142.
Full textAbstract:
Calcium pyrophosphate crystal deposition (CPPD) in articular cartilage is a common age-related phenomenon. Recent important advances in our understanding of the pathophysiology of pyrophosphate metabolism include the identification of a mutation within the ANK gene which associates with familial CPPD, and elucidation of the interleukin-1β (IL-1β)-dependent mechanisms by which crystals invoke an inflammatory response. Risk factors for CPPD include age, prior joint damage and osteoarthritis, genetic factors, and occasionally metabolic diseases (hyperparathyroidism, haemochromatosis, hypomagnesaemia, and hypophosphatasia). CPPD is commonly asymptomatic or may present as osteoarthritis with CPPD, acute calcium pyrophosphate (CPP) crystal arthritis, or chronic CPP crystal inflammatory arthritis. Although radiographic chondrocalcinosis is often taken to be synonymous with CPPD, other calcium crystals can also have this appearance and definitive diagnosis requires identification of CPP crystals by compensated polarized light microscopy of aspirated synovial fluid. Recently, the ultrasonographic appearances of CPPD have been described. Treatment of CPPD is targeted to the clinical presentation. Acute CPP crystal arthritis is treated by aspiration and injection of glucocorticosteroid, local ice packs, non-steroidal anti-inflammatory drugs (NSAIDS), low-dose colchicine, oral or parenteral glucocorticosteroids, or adrenocorticotrophic hormone (ACTH). Treatment of osteoarthritis with CPPD is very similar to the treatment of osteoarthritis alone. There is no specific therapy for chronic CPP crystal inflammatory arthritis: options include NSAID, low-dose colchicine, low-dose glucocorticosteroid, methotrexate, and hydroxychloroquine. Recommendations for the management of CPPD are derived from a small evidence base and largely based on clinical experience and extrapolation from gout. Further research into diagnosis and management including novel treatment strategies such as IL-1β blockade is much needed.
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Abhishek, Abhishek, and Michael Doherty. Treatment of calcium pyrophosphate deposition. Oxford University Press, 2016. http://dx.doi.org/10.1093/med/9780199668847.003.0052.
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The treatment of calcium pyrophosphate crystal deposition (CPPD) is mainly symptomatic. Acute calcium pyrophosphate (CPP) crystal synovitis should be treated with rest, local application of ice packs, joint aspiration, and/or intra-articular corticosteroid injection (once joint sepsis has been excluded). Oral colchicine or prednisolone may be used if joint aspiration and/or injection are not feasible. Anti-inflammatory agents (with proton pump inhibitors) may be used but in general these should be avoided as most patients with acute CPP crystal arthritis are elderly, and at a high risk of gastrointestinal and renal complication of non-steroidal anti-inflammatory drug (NSAIDs). Principles of management of CPPD with osteoarthritis (OA) are identical to those for isolated OA. However, patients may have more inflammatory signs and symptoms and periodic joint aspiration and corticosteroid injection may be required more often than in isolated OA. Oral NSAIDs (with gastro-protection), colchicine, low-dose corticosteroids, hydroxychloroquine, and radiosynovectomy have been suggested as options for the treatment of chronic CPP crystal arthritis. There is growing interest in use of anti-interleukin-1 agents for acute or chronic CPP crystal arthritis but the efficacy of these agents has not been formally studied, and their use should be considered on an individual basis.
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Khanna, Puja. Treatment of acute gout. Oxford University Press, 2016. http://dx.doi.org/10.1093/med/9780199668847.003.0045.
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Acute gout is a common inflammatory arthritis in the adult population. Epidemiological evidence suggests that the prevalence of gout is steadily on the rise due to longevity, coexisting comorbidities, and iatrogenic causes contributing to hyperuricaemia. Acute gout usually presents as a self-limiting flare of synovitis that occurs due to deposition of monosodium urate crystals. The frequency of flares generally increases over time in patients who continue to have hyperuricaemia and their risk factors for acute gout attacks have not been adequately addressed. Effective treatment of acute gouty arthritis is primary focused on pain which is the primary symptom but must target both the pain and underlying inflammation. Acute gout is frequently treated with non-steroidal anti-inflammatory agents, colchicine, and corticosteroids. This chapter reviews the available therapies for management of acute gout and ones that have shown promising results.
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Richette, Pascal. Principles of gout management. Oxford University Press, 2016. http://dx.doi.org/10.1093/med/9780199668847.003.0044.
Full textAbstract:
The general goals of gout therapy are to manage acute flares and to prevent recurrences and prevent or reverse the complications of urate deposition by lowering urate levels. The choice of drug should be made on the basis of the patient’s co-morbidities, other medications, and side effect profile. Treatment of flares can be achieved with non-steroidal anti-inflammatory drugs, colchicine, or corticosteroids (systemic or intra-articular). Interleukin-1 blockers could become an alternative in patients contraindicated for traditional anti-inflammatory agents. Lowering of urate levels below monosodium urate (MSU) saturation point with both a non-pharmacological and pharmacological approach allows to dissolve MSU crystals and to cure gout. Serum urate (SUA) levels should be maintained below 6 mg/dL (360 μmol/L) or below 5 mg/dL (300 μmol/L) in patients with severe gout to facilitate faster dissolution of crystals. Urate-lowering therapy (ULT) should be initiated close to the first diagnosis of gout. Allopurinol and febuxostat are the most widely used xanthine oxidase inhibitors to lower SUA levels. If the SUA target cannot be reached by these agents, uricosurics are indicated, either alone or in combination with a xanthine oxidase inhibitor. In patients with severe tophaceous gout in whom the SUA target cannot be reached with any other available drug, pegloticase is indicated. Since ULT initiation may trigger acute attacks of gout, prophylaxis with an anti-inflammatory agent is recommended, mostly with low-dose colchicine. Of note, patient education, appropriate lifestyle advice, and treatment of comorbidities are also important parts of the management of patients with gout.
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Dalbeth, Nicola. Gout. Oxford University Press, 2013. http://dx.doi.org/10.1093/med/9780199642489.003.0141.
Full textAbstract:
Gout is a common and treatable disorder of purine metabolism. Gout typically presents as recurrent self-limiting episodes of severe inflammatory arthritis affecting the foot. In the presence of persistent hyperuricaemia, tophi, chronic synovitis, and joint damage may develop. Diagnosis of gout is confirmed by identification of monosodium urate (MSU) crystals using polarizing light microscopy. Hyperuricaemia is the central biochemical cause of gout. Genetic variants in certain renal tubular urate transporters including SLC2A9 and ABCG2, and dietary factors including intake of high-purine meats and seafood, beer, and fructose, contribute to development of hyperuricaemia and gout. Gout treatment includes: (1) management of the acute attack using non-steroidal anti-inflammatory drugs (NSAIDs), corticosteroids, or low-dose colchicine; (2) prophylaxis against gout attacks when commencing urate-lowering therapy (ULT), with NSAIDs or colchicine; and (3) long-term ULT to achieve a target serum urate of less than 0.36 mmol/litre. Interleukin (IL)-1β is a central mediator of acute gouty inflammation and anti-IL-1β therapies show promise for treatment of acute attacks and prophylaxis. The mainstay of ULT remains allopurinol. However, old ULT agents such as probenecid and benzbromarone and newer agents such as febuxostat and pegloticase are also effective, and should be considered in patients in whom allopurinol is ineffective or poorly tolerated. Management of gout should be considered in the context of medical conditions that frequently coexist with gout, including type 2 diabetes, hypertension, dyslipidaemia, and chronic kidney disease. Patient education is essential to ensure that acute gout attacks are promptly and safely managed, and long-term ULT is maintained.
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Dalbeth, Nicola. Gout. Oxford University Press, 2016. http://dx.doi.org/10.1093/med/9780199642489.003.0141_update_003.
Full textAbstract:
Gout is a common and treatable disorder of purine metabolism. Gout typically presents as recurrent self-limiting episodes of severe inflammatory arthritis affecting the foot. In the presence of persistent hyperuricaemia, tophi, chronic synovitis, and joint damage may develop. Diagnosis of gout is confirmed by identification of monosodium urate (MSU) crystals using polarizing light microscopy. Hyperuricaemia is the central biochemical cause of gout. Genetic variants in certain renal tubular urate transporters including SLC2A9 and ABCG2, and dietary factors including intake of high-purine meats and seafood, beer, and fructose, contribute to development of hyperuricaemia and gout. Gout treatment includes: (1) management of the acute attack using non-steroidal anti-inflammatory drugs (NSAIDs), corticosteroids, or low-dose colchicine; (2) prophylaxis against gout attacks when commencing urate-lowering therapy (ULT), with NSAIDs or colchicine; and (3) long-term ULT to achieve a target serum urate of less than 0.36 mmol/litre. Interleukin (IL)-1β is a central mediator of acute gouty inflammation and anti-IL-1β therapies show promise for treatment of acute attacks and prophylaxis. The mainstay of ULT remains allopurinol. However, old ULT agents such as probenecid and benzbromarone and newer agents such as febuxostat and pegloticase are also effective, and should be considered in patients in whom allopurinol is ineffective or poorly tolerated. Management of gout should be considered in the context of medical conditions that frequently coexist with gout, including type 2 diabetes, hypertension, dyslipidaemia, and chronic kidney disease. Patient education is essential to ensure that acute gout attacks are promptly and safely managed, and long-term ULT is maintained.
Book chapters on the topic "Steroid crystals"
1
Duax, W. L., C. M. Weeks, and D. C. Rohrer. "Crystal Structures of Steroids." In Topics in Stereochemistry, 271–383. Hoboken, NJ, USA: John Wiley & Sons, Inc., 2007. http://dx.doi.org/10.1002/9780470147184.ch5.
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Tiekink, Edward R. T. "Steric Control over Supramolecular Aggregation: A Design Element in Crystal Engineering?" In Frontiers in Crystal Engineering, 117–34. Chichester, UK: John Wiley & Sons, Ltd, 2006. http://dx.doi.org/10.1002/0470022612.ch6.
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Duax, W. L., and J. F. Griffin. "Modelling steroid hormone receptor interactions on the basis of crystallographic and biochemical studies." In Organic Crystal Chemistry, 36–53. Oxford University PressOxford, 1991. http://dx.doi.org/10.1093/oso/9780198553830.003.0004.
Full textAbstract:
Abstract Steroid hormones are vital to numerous physiological processes including cell growth, sexual development, maintenance of salt balance and sugar metabolism. Many of these activities are known to be contingent upon the binding of steroids to specific cytosolic protein receptors and the subsequent interaction of the steroid receptor complex with chromatin (Jensen et al., 1962).
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Roddy, Edward, and Michael Doherty. "Calcium pyrophosphate crystal deposition (CPPD)." In Oxford Textbook of Rheumatology, 1211–22. Oxford University Press, 2013. http://dx.doi.org/10.1093/med/9780199642489.003.0142_update_001.
Full textAbstract:
Calcium pyrophosphate crystal deposition (CPPD) in articular cartilage is a common age-related phenomenon. Recent important advances in our understanding of the pathophysiology of pyrophosphate metabolism include the identification of a mutation within the ANK gene which associates with familial CPPD, and elucidation of the interleukin-1β (IL-1β)-dependent mechanisms by which crystals invoke an inflammatory response. Risk factors for CPPD include age, prior joint damage and osteoarthritis, genetic factors, and occasionally metabolic diseases (hyperparathyroidism, haemochromatosis, hypomagnesaemia, and hypophosphatasia). CPPD is commonly asymptomatic or may present as osteoarthritis with CPPD, acute calcium pyrophosphate (CPP) crystal arthritis, or chronic CPP crystal inflammatory arthritis. Although radiographic chondrocalcinosis is often taken to be synonymous with CPPD, other calcium crystals can also have this appearance and definitive diagnosis requires identification of CPP crystals by compensated polarized light microscopy of aspirated synovial fluid. Recently, the ultrasonographic appearances of CPPD have been described. Treatment of CPPD is targeted to the clinical presentation. Acute CPP crystal arthritis is treated by aspiration and injection of glucocorticosteroid, local ice packs, non-steroidal anti-inflammatory drugs (NSAIDS), low-dose colchicine, oral or parenteral glucocorticosteroids, or adrenocorticotrophic hormone (ACTH). Treatment of osteoarthritis with CPPD is very similar to the treatment of osteoarthritis alone. There is no specific therapy for chronic CPP crystal inflammatory arthritis: options include NSAID, low-dose colchicine, low-dose glucocorticosteroid, methotrexate, and hydroxychloroquine. Recommendations for the management of CPPD are derived from a small evidence base and largely based on clinical experience and extrapolation from gout. Further research into diagnosis and management including novel treatment strategies such as IL-1β blockade is much needed.
5
Duax, W. L., J. F. Griffin, and Clair Cheer. "Steroid Conformational Analyses Based on X-Ray Crystal Structure Determination." In Analysis of Sterols and Other Biologically Significant Steroids, 203–21. Elsevier, 1989. http://dx.doi.org/10.1016/b978-0-12-515445-1.50015-x.
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Glusker, Jenny P., and Aldo Domenicano. "X-ray crystallography: an introduction." In Accurate Molecular Structures, 126–69. Oxford University PressOxford, 1992. http://dx.doi.org/10.1093/oso/9780198555568.003.0006.
Full textAbstract:
Abstract The chemist would like to be able to visualize molecules and the atoms in them and so obtain a direct three-dimensional view. For example, when considering reaction mechanisms it is difficult to determine the extent of steric hindrance or the accessibility of functional groups if one does not have a three-dimensional view of the system. The electron microscope can, as was shown, for example, by Labaw and Wyckoff (1958), be used to view macromolecules such as those of viruses. It can also be used to image the lattice defects in certain stable inorganic compounds (Iijima 1973). But when one needs precise geometrical data on molecules, an excellent method to choose is an analysis of the X-ray or neutron diffraction patterns obtained from single crystals of the substance of interest. The result of such an analysis is a vast wealth of data on the relative positions of atoms, ions or molecules in a crystal, and a measure of the variability of these positions.
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Chong, Josephine Y. T., Xavier Mulet, Ben J. Boyd, and Calum J. Drummond. "Steric Stabilizers for Cubic Phase Lyotropic Liquid Crystal Nanodispersions (Cubosomes)." In Advances in Planar Lipid Bilayers and Liposomes, 131–87. Elsevier, 2015. http://dx.doi.org/10.1016/bs.adplan.2014.11.001.
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DICK, J. J., E. GARCIA, and D. C. SHAW. "SHOCK INITIATION OF PENTAERYTHRITOL TETRANITRATE CRYSTALS: STERIC EFFECTS DUE TO PLASTIC FLOW." In Shock Compression of Condensed Matter–1991, 349–52. Elsevier, 1992. http://dx.doi.org/10.1016/b978-0-444-89732-9.50079-0.
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Chaudhary, Mr Zaid, and Ms Shelly Raghav. "A COMPREHENSIVE REVIEW OF MICROSCOPICAL CHARACTERS OF POWDER OF LEAVES OF SYZYGIUM CUMINI." In MICROSCOPICAL EVALUATION OF MEDICINAL PLANTS. KAAV PUBLICATIONS, 2023. http://dx.doi.org/10.52458/9788196830014.2023.eb.ch-20.
Full textAbstract:
Syzygium cumini (L.) Skeels, commonly known as Jamun and belonging to the Myricaceae family, holds significant medicinal importance in Ayurveda. Despite its widespread medicinal applications, there is a lack of published information on the pharmacognostic characterization and physicochemical analysis of its leaves. The study employed various measures, including macroscopy, microscopy, powder microscopy, physicochemical evaluation, fluorescence analysis, and preliminary phytochemical screening, to address this gap. Microscopic evaluation revealed distinctive features aiding in the identification of Syzygium cumini (L.) Skeels leaves. The transverse section exhibited a single layer of wavy epidermal cells with a striated cuticle, a single layer of palisade beneath the upper epidermis in the lamina region, spheraphide in the lamina region, collenchyma in the midrib region below the upper epidermis and above the lower epidermis, and xylem and phloem in the center. Sclerenchyma was observed between the vascular bundle and collenchyma in the midrib region. The powder microscopy further revealed features such as wavy epidermal cells in the upper epidermis, anisocytic stomata in the lower epidermis, bordered pitted reticulate vessels, a calcium oxalate crystal sheath in the lamina, and fragments of fibers and spiral vessels. Physicochemical studies reported total ash (3.1%), acid-insoluble ash (0.7%), alcohol-soluble extractive values (10.96%), and water-soluble extractive values (12.32%). Phytochemical analysis detected the presence of sugar, lipid, glycoside, saponins, phenols, flavonoids, tannins, triterpenoids, and steroids. This study serves as the initial documentation of pharmacognostic characters and physicochemical parameters, offering valuable insights for the identification and authentication of Syzygium cumini leaves.
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Dalbeth, Nicola. "Gout." In Oxford Textbook of Rheumatology, 1199–210. Oxford University Press, 2013. http://dx.doi.org/10.1093/med/9780199642489.003.0141_update_004.
Full textAbstract:
Gout is a common and treatable disorder of purine metabolism. Gout typically presents as recurrent self-limiting episodes of severe inflammatory arthritis affecting the foot. In the presence of persistent hyperuricaemia, tophi, chronic synovitis, and joint damage may develop. Diagnosis of gout is confirmed by identification of monosodium urate (MSU) crystals using polarizing light microscopy. Hyperuricaemia is the central biochemical cause of gout. Genetic variants in certain renal tubular urate transporters including SLC2A9 and ABCG2, and dietary factors including intake of high-purine meats and seafood, beer, and fructose, contribute to development of hyperuricaemia and gout. Gout treatment includes: (1) management of the acute attack using non-steroidal anti-inflammatory drugs (NSAIDs), corticosteroids, or low-dose colchicine; (2) prophylaxis against gout attacks when commencing urate-lowering therapy (ULT), with NSAIDs or colchicine; and (3) long-term ULT to achieve a target serum urate of less than 0.36 mmol/litre. Interleukin (IL)-1β is a central mediator of acute gouty inflammation and anti-IL-1β therapies show promise for treatment of acute attacks and prophylaxis. The mainstay of ULT remains allopurinol. However, old ULT agents such as probenecid and benzbromarone and newer agents such as febuxostat and pegloticase are also effective, and should be considered in patients in whom allopurinol is ineffective or poorly tolerated. Management of gout should be considered in the context of medical conditions that frequently coexist with gout, including type 2 diabetes, hypertension, dyslipidaemia, and chronic kidney disease. Patient education is essential to ensure that acute gout attacks are promptly and safely managed, and long-term ULT is maintained.
Conference papers on the topic "Steroid crystals"
1
Gvozdovskyy, I. A., Irina P. Terenetskaya, and Victor Y. Reshetnyak. "Dissolution of steroid crystals in a nematic droplet: effect of rotation." In SPIE Proceedings, edited by Gertruda V. Klimusheva, Andrey G. Iljin, and Sergey A. Kostyukevych. SPIE, 2003. http://dx.doi.org/10.1117/12.545829.
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Furman, Jolanta, and Leszek Makaruk. "New linear liquid crystal polyesters containing bulky steric aliphatic substituents in mesogenic units." In Liquid Crystals: Materials Science and Applications, edited by Jozef Zmija. SPIE, 1995. http://dx.doi.org/10.1117/12.215552.
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Arulraj, Anthony, N. V. Chandra Shekar, and P. Ch Sahu. "The role of steric effects on high pressure crystal structure of Ho2O3." In SOLID STATE PHYSICS: Proceedings of the 56th DAE Solid State Physics Symposium 2011. AIP, 2012. http://dx.doi.org/10.1063/1.4709916.
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Wan, Mei, Jiyuan Fang, Jiale Zhang, Zhi Hong, and Yong Du. "Terahertz Spectroscopy and Crystal Structure Analysis of Non-Steroidal Anti-Inflammatory Drug Ethenzamide Cocrystals." In 2022 47th International Conference on Infrared, Millimeter and Terahertz Waves (IRMMW-THz). IEEE, 2022. http://dx.doi.org/10.1109/irmmw-thz50927.2022.9895745.
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Pasquerella, Dean A., and Ann M. Anderson. "A Comparison of Chiral Nematic and Cholesteric Thermochromic Liquid Crystals for Use in a Light Transmission Based Temperature Sensing System." In ASME 2007 International Mechanical Engineering Congress and Exposition. ASMEDC, 2007. http://dx.doi.org/10.1115/imece2007-41855.
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This paper presents the results of a study performed to examine the effectiveness of several different formulations of thermochromic liquid crystal (TLC) material for use in a light transmission based temperature measurement system. We report on experiments performed on six different types of TLC material. We used a spectrophotometer to measure the percent of light transmitted through a layer of each TLC material for wavelengths from 400 to 700 nm as a function of temperature. We also applied TLC material directly onto electroluminescent lights and used a CCD camera to look at the intensity of red, green, and blue light transmitted through each layer as a function of temperature. We found that pure unsealed materials, both cholesteric and chiral nematic (non-sterol), are not suited for use in a temperature measurement system. They show little response to temperature and are difficult to work with due to their low melting point. On the other hand, the micro-encapsulated TLC slurry materials showed a large responsive range and were easier to work with than the pure materials. The chiral nematic material showed the largest sensitivity to temperature and was found to be more responsive than the cholesteric material.
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Li, DeQuan, Xiaoguang Yang, and Duncan McBranch. "Molecular Architectural Approaches to Nonlinear Optical Materials." In Nonlinear Optics: Materials, Fundamentals and Applications. Washington, D.C.: Optica Publishing Group, 1996. http://dx.doi.org/10.1364/nlo.1996.nthe.12.
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The design and construction of artificial supramolecular architectures on surfaces is of great current interest and represents an important aspect of molecular self-assembly, because self-assembly offers highly ordered mesoscale structures with desired chemical functionalities and physical properties. The fabrication of polar molecular superstructures proves particularly challenging since polar molecular materials are essential to second-order nonlinear optical (NLO) technologies. Several approaches such as the Langmuir-Blodgett technique and liquid crystals have been reported to generate molecular-based materials with organized polar structures. However, the orientation in these materials is maintained by weak bonding or steric hindrance, which lose the polar alignment over time. Recent developments in self-assembly and host-guest chemistry offer a novel route to ordered materials through the design and synthesis of new molecular building blocks that can be organized into supramolecular assemblies. The synthetic approach here is to fix dipole orientation by structural interlocking of NLO chromophores into cone conformation, and then to utilize them to build polar self-assembled monolayers. In this report, we discuss the molecular design of calixarene-based, NLO molecular "pyramids", their monolayer self-assemblies on oxide surfaces, and their spectroscopic second order NLO properties.
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Houston, J. E., C. M. Doelling, T. Kyle Vanderlick, Y. Hu, G. Scoles, I. Wenzl, and T. Randall Lee. "Adhesion, Friction and Mechanical Properties of CF3- and CH3-Terminated Alkanethiol Monolayers: A Comparative Study." In World Tribology Congress III. ASMEDC, 2005. http://dx.doi.org/10.1115/wtc2005-63769.
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Self-assembled monolayers (SAMs) have received considerable recent attention as molecular-level lubricants in, for example, micro-electro-mechanical systems (MEMS).[1] Of particular interest as tribological films have been SAMs terminated by fluorocarbon groups, because of their inert nature and enhanced thermal stability. Surprisingly however, fluorocarbon films were shown to actually produce higher coefficients of friction (relative to CH3-terminated films) in atomic force microscopy (AFM) studies. Subsequent work has concluded that the increased van der Waals radius of the fluorine groups (∼45%) causes a steric disruption of the order of the molecular surface giving rise to an increased friction.[2] We present results from a direct comparison of the adhesive, mechanical and frictional properties of SAMs terminated by CF3 and CH3 groups using both Interfacial Force Microscopy[3] (IFM) and the AFM. IFM results are shown for a two micron tungsten tip interacting with C16 alkylthiol molecules assembled on Au(111) single-crystal surfaces. AFM results involve a ∼20 nm tip interacting with the same two molecules assembled on Au films deposited on mica surfaces. A direct AFM comparison is accomplished by using a “nanografting technique”.[4]