34,867 results match your criteria determined crystal


Structure-Property Relationships in Photoluminescent Bismuth Halide Organic Hybrid Materials.

Inorg Chem 2021 Jun 15. Epub 2021 Jun 15.

Department of Chemistry, Georgetown University, 37th and O Streets, NW, Washington, DC 20057, United States.

Seven novel bismuth(III)-halide phases, BiCl(terpy)·0.5(HO) (), BiCl(terpy)(-TC)() (TC = 2-thiophene monocarboxylate), BiCl(terpy)(-TC) (), BiBr(terpy)(-TC) (), BiCl(terpy)(-TC) (), [BiCl(terpy)(-TC)][Bi(terpy)(-TC)]·0.55(TCA) (), [BiBr(terpy)(MeOH)] (), and [BiBr(terpy)(-TC)][BiBr(terpy)(-TC)] (), were prepared under mild synthetic conditions from methanolic/aqueous solutions containing BiX (X = Cl, Br) and 2,2':6',2″-terpyridine (terpy) and/or 2-thiophene monocarboxylic acid (TCA). Read More

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An Orthorhombic Modification of KCoPO Stabilized under Hydrothermal Conditions: Crystal Chemistry and Magnetic Behavior.

Inorg Chem 2021 Jun 15. Epub 2021 Jun 15.

National Research South Ural State University, Chelyabinsk 454080, Russia.

A novel modification of the KCoPO, δ-phase has been prepared by hydrothermal synthesis at 553 K. The compound crystallizes in the orthorhombic system with the unit-cell parameters = 8.5031(8), = 10. Read More

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Effect of Compounds from Moringa oleifera Lam. on in Vitro Non-Alcoholic Fatty Liver Disease (NAFLD) Model System.

Chem Biodivers 2021 Jun 14. Epub 2021 Jun 14.

Department of Applied Chemistry, College of Science and Technology, Nihon University, 1-5-1 Kandasurugadai, Chiyoda, Tokyo, 101-0062, Japan.

Non-alcoholic fatty liver disease (NAFLD) is currently the most common chronic liver disease in the world, with a prevalence of 25 % in many countries. To date, no drug has been approved to treat NAFLD, therefore, the use of phytochemicals to prevent this disease is meaningful. In this study, we focused on the effects of Moringa oleifera Lam. Read More

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In vitro effects of 2 bioactive compounds, gallic acid and methyl gallate, on urolithiasis.

Actas Urol Esp 2021 Jun 11. Epub 2021 Jun 11.

Programa de Pós-graduação em Ciências Farmacêuticas, Núcleo de Investigações Químico-Farmacêuticas (NIQFAR), Universidade do Vale do Itajaí (UNIVALI), Itajaí, Santa Catarina, Brasil. Electronic address:

Introduction And Objectives: This study aimed to evaluate the role of 2 widely distributed natural phenolic compounds, gallic acid (GA) and methyl gallate (MG), in an in vitro model of urolithiasis, by using the methodology of calcium oxalate crystals formation, which is the most common type of urinary or kidney stones.

Material And Methods: The compounds GA and MG were subjected to anti-crystallization activities in different concentrations (0.003-0. Read More

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Diastereoselective synthesis of chiral 3-substituted isoindolinones rhodium(III)-catalyzed oxidative C-H olefination/annulation.

Org Biomol Chem 2021 Jun 14. Epub 2021 Jun 14.

College of Chemistry, Green Catalysis Center, Zhengzhou University, Zhengzhou 450001, People's Republic of China.

A new method for the direct and stereoselective synthesis of 3-substituted isoindolinones via Rh(iii)-catalyzed chiral N-sulfinyl amide directed asymmetric [4 + 1] annulation of benzamides with acrylic esters has been developed. The reaction proceeded through an oxidative C-H olefination and a subsequent cyclization by intramolecular aza-Michael addition, producing a series of diastereoisomeric chiral isoindolinones (20 examples) in generally good yields with a dr value up to 5.5 : 1. Read More

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Structure-property relationship of a soft colloidal glass in simple and mixed flows.

J Colloid Interface Sci 2021 May 21;601:454-466. Epub 2021 May 21.

Okinawa Institute of Science and Technology Graduate University, 1919-1 Tancha, Onna-son, Okinawa 904-0495, Japan. Electronic address:

Hypothesis: Under specific conditions, rod-like cellulose nanocrystals (CNC) can assemble into structurally ordered soft glasses (SGs) with anisotropy that can be controlled by applying shear. However, to achieve full structural control of SGs in real industrial processes, their response to mixed shear and extensional kinematics needs to be determined. We hypothesise that by knowing the shear rheology of the CNC-based soft glass and adopting a suitable constitutive model, it is possible to predict the structure-property relationship of the SG under mixed flows. Read More

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Targeting immunodominant Bet v 1 epitopes with monoclonal antibodies prevents the birch allergic response.

J Allergy Clin Immunol 2021 Jun 11. Epub 2021 Jun 11.

Regeneron Pharmaceuticals, Inc., Tarrytown, NY, USA. Electronic address:

Background: Blocking the major cat allergen, Fel d 1, with monoclonal antibodies (mAbs) was effective in preventing an acute cat-allergic response.

Objective: We sought to extend the allergen-specific antibody approach and demonstrate that a combination of mAbs targeting Bet v 1, the immunodominant and most abundant allergenic protein in birch pollen, can prevent the birch-allergic response.

Methods: Bet v 1-specific mAbs, REGN5713, REGN5714 and REGN5715, were isolated using the VelocImmune platform. Read More

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Insights into xanthine riboswitch structure and metal ion-mediated ligand recognition.

Nucleic Acids Res 2021 Jun 14. Epub 2021 Jun 14.

Life Sciences Institute, Zhejiang University, Hangzhou, Zhejiang 310058, China.

Riboswitches are conserved functional domains in mRNA that mostly exist in bacteria. They regulate gene expression in response to varying concentrations of metabolites or metal ions. Recently, the NMT1 RNA motif has been identified to selectively bind xanthine and uric acid, respectively, both are involved in the metabolic pathway of purine degradation. Read More

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π-Conjugated stannole copolymers synthesised by a tin-selective Stille cross-coupling reaction.

Mater Adv 2021 Mar 27;2(10):3282-3293. Epub 2021 Mar 27.

Institute for Organic and Analytical Chemistry, University of Bremen Leobener Str. 7 28359 Bremen Germany

The synthesis of four well-defined conjugated polymers containing unusual heterocycle units in the main chain, namely stannole units as building blocks, is reported. The stannole-thiophenyl copolymers were generated by tin-selective Stille coupling reactions in nearly quantitative yields of 94% to 98%. NMR data show that the tin atoms in the rings remain unaffected. Read More

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Prediction and Classification of Formation Energies of Binary Compounds by Machine Learning: An Approach without Crystal Structure Information.

ACS Omega 2021 Jun 26;6(22):14533-14541. Epub 2021 May 26.

Department of Physics & Guangdong Provincial Key Laboratory of Computational Science and Material Design, Southern University of Science and Technology, Shenzhen 518055, China.

It is well believed that machine learning models could help to predict the formation energies of materials if all elemental and crystal structural details are known. In this paper, it is shown that even without detailed crystal structure information, the formation energies of binary compounds in various prototypes at the ground states can be reasonably evaluated using machine-learning feature abstraction to screen out the important features. By combining with the "white-box" sure independence screening and sparsifying operator (SISSO) approach, an interpretable and accurate formation energy model is constructed. Read More

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Stabilizing a three-center single-electron metal-metal bond in a fullerene cage.

Chem Sci 2021 Apr 2;12(20):6890-6895. Epub 2021 Apr 2.

Hefei National Laboratory for Physical Sciences at Microscale, CAS Key Laboratory of Materials for Energy Conversion, Department of Materials Science and Engineering, Synergetic Innovation Center of Quantum Information & Quantum Physics, University of Science and Technology of China Hefei 230026 China

Trimetallic carbide clusterfullerenes (TCCFs) encapsulating a quinary MC cluster represent a special family of endohedral fullerenes with an open-shell electronic configuration. Herein, a novel TCCF based on a medium-sized rare earth metal, dysprosium (Dy), is synthesized for the first time. The molecular structure of [email protected](7)-C determined by single crystal X-ray diffraction shows that the encapsulated DyC cluster adopts a bat ray configuration, in which the acetylide unit C is elevated above the Dy plane by ∼1. Read More

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Ruthenium-Benzothiadiazole Building Block Derived Dynamic Heterometallic Ru-Ag Coordination Polymer and Its Enhanced Water-Splitting Feature.

Inorg Chem 2021 Jun 14. Epub 2021 Jun 14.

Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai 400076, India.

This article deals with the development of the unprecedented redox-mediated heterometallic coordination polymer {[Ru(acac)(μ-bis-η-,η-NBTD)Ag(ClO)]ClO} () via the oxidation of the monomeric building block -[Ru(acac)(η-N-BTD)] () by AgClO (BTD = exodentate 2,1,3-benzothiadiazole, acac = acetylacetonate). Monomeric -[Ru(acac)(η-N-BTD)] () and [Ru(acac)(η--BTD)(CHCN)] () were simultaneously obtained from the electron-deficient BTD heterocycle and the electron-rich metal precursor Ru(acac)(CHCN) in refluxing CHCN. Molecular identities of - were authenticated by their single-crystal X-ray structures as well as by solution spectral features. Read More

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Molecular and structural characterization of agmatine coumaroyltransferase in Triticeae, the key regulator of hydroxycinnamic acid amide accumulation.

Phytochemistry 2021 Jun 10;189:112825. Epub 2021 Jun 10.

Department of Agricultural Chemistry, Tokyo University of Agriculture, Setagaya, Tokyo, 156-8502, Japan. Electronic address:

Hydroxycinnamic acid amides (HCAAs) are involved in stress-induced defense in many plant species. Barley accumulates high concentrations of HCAAs irrespective of exogenous stressors, while other major cereals such as wheat and rice accumulate relatively low levels of HCAAs in intact tissues. The primary HCAA species in barley are biosynthesized by agmatine p-coumaroyltransferase (ACT), an N-acyltransferase of the BAHD superfamily. Read More

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Gout of feet and ankles in different disease durations: diagnostic value of single-source DECT and evaluation of urate deposition with a novel semi-quantitative DECT scoring system.

Adv Rheumatol 2021 Jun 12;61(1):36. Epub 2021 Jun 12.

Department of Radiology, The First Affiliated Hospital of Anhui Medical University, 210 Jixi Road, Hefei, 230022, Anhui, China.

Objectives: To investigate the diagnostic performance of single-source dual-energy computed tomography (DECT) based on gemstone spectral imaging technology (including Discovery CT750HD and Revolution CT) in patients with suspected feet/ankles gouty arthritis, and evaluate the urate deposition with a novel semi-quantitative DECT scoring system.

Methods: A total of 196 patients were consecutively included. Feet and ankles were evaluated in all patients by single-source DECT scan. Read More

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3D Electron Diffraction Structure Determination of Terrylene, a Promising Candidate for Intermolecular Singlet Fission.

Chemphyschem 2021 Jun 12. Epub 2021 Jun 12.

University of Bristol, School of Chemistry, Cantocks Close, BS81TS, Bristol, UNITED KINGDOM.

Herein we demonstrate the prowess of the 3D electron diffraction approach by unveiling the structure of terrylene, the third member in the series of peri-condensed naphthalene analogues, which has eluded structure determination for 65 years. The structure was determined by direct methods using electron diffraction data and corroborated by dispersion-inclusive density functional theory optimizations. Terrylene crystalizes in the monoclinic space group P21/a, arranging in a sandwich-herringbone packing motif, similar to analogous compounds. Read More

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High resolution crystal structure of the Borreliella burgdorferi PlzA protein in complex with c-di-GMP: new insights into the interaction of c-di-GMP with the novel xPilZ domain.

Pathog Dis 2021 Jun 12. Epub 2021 Jun 12.

Department of Microbiology and Immunology, Virginia Commonwealth University Medical Center, 1112 East Clay Street, Room 101 McGuire Hall, Richmond, VA 23298-0678 USA.

In the tick-borne pathogens, Borreliella burgdorferi and Borrelia hermsii, c-di-GMP is produced by a single diguanylate cyclase (Rrp1). In these pathogens, the Plz proteins (PlzA, B and C) are the only c-di-GMP receptors identified to date and PlzA is the sole c-di-GMP receptor found in all Borreliella isolates. Bioinformatic analyses suggest that PlzA has a unique PilZN3-PilZ architecture with the relatively uncommon xPilZ domain. Read More

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Structural basis of coronavirus E protein interactions with human PALS1 PDZ domain.

Commun Biol 2021 Jun 11;4(1):724. Epub 2021 Jun 11.

Department of Biochemistry & Genetics, La Trobe Institute for Molecular Science, La Trobe University, Melbourne, Vic, Australia.

SARS-CoV-2 infection leads to coronavirus disease 2019 (COVID-19), which is associated with severe and life-threatening pneumonia and respiratory failure. However, the molecular basis of these symptoms remains unclear. SARS-CoV-1 E protein interferes with control of cell polarity and cell-cell junction integrity in human epithelial cells by binding to the PALS1 PDZ domain, a key component of the Crumbs polarity complex. Read More

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Crystal structure of the anti-CRISPR repressor Aca2.

J Struct Biol 2021 Jun 8:107752. Epub 2021 Jun 8.

Department of Biosciences, Durham University, Stockton Road, Durham, DH1 3LE, UK. Electronic address:

Bacteria use adaptive CRISPR-Cas immune mechanisms to protect from invasion by bacteriophages and other mobile genetic elements. In response, bacteriophages and mobile genetic elements have co-evolved anti-CRISPR proteins to inhibit the bacterial defense. We and others have previously shown that anti-CRISPR associated (Aca) proteins can regulate this anti-CRISPR counter-attack. Read More

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An atomic model for the human septin hexamer by cryo-EM.

J Mol Biol 2021 Jun 8:167096. Epub 2021 Jun 8.

São Carlos Institute of Physics, USP, São Carlos, SP, Brazil.

In order to form functional filaments, human septins must assemble into hetero-oligomeric rod-like particles which polymerize end-to-end. The rules governing the assembly of these particles and the subsequent filaments are incompletely understood. Although crystallographic approaches have been successful in studying the separate components of the system, there has been difficulty in obtaining high resolution structures of the full particle. Read More

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A reverse catalytic triad Asp containing loop shaping a wide substrate binding pocket of a feruloyl esterase from Lactobacillus plantarum.

Int J Biol Macromol 2021 Jun 9;184:92-100. Epub 2021 Jun 9.

Laboratory of Biomanufacturing and Food Engineering, Institute of Food Science and Technology, Chinese Academy of Agricultural Sciences, Beijing 100193, China. Electronic address:

Feruloyl esterase is an indispensable biocatalyst in food processing, pesticide and pharmaceutical industries, catalyzing the cleavage of the ester bond cross-linked between the polysaccharide side chain of hemicellulose and ferulic acid in plant cell walls. LP_0796 from Lactobacillus plantarum was identified as a feruloyl esterase that may have potential applications in the food industry, but the lack of the substrate recognition and catalytic mechanisms limits its application. Here, LP_0796 showed the highest activity towards methyl caffeate at pH 6. Read More

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Chiral deaza-coelenterazine analogs for probing a substrate-binding site in the Ca2+-binding photoprotein aequorin.

PLoS One 2021 11;16(6):e0251743. Epub 2021 Jun 11.

Laboratory for Chemical Biology, RIKEN Center for Biosystems Dynamics Research (BDR), Kobe, Japan.

The Ca2+-binding photoprotein aequorin is a complex of apoAequorin (apoprotein) and (S)-2-peroxycoelenterazine. Aequorin can be regenerated by the incubation of apoAequorin with coelenterazine and molecular oxygen (O2). In this study, to investigate the molecular recognition of apoAequorin for coelenterazine using chemical probes, the chiral deaza-analogs of (S)- and (R)-deaza-CTZ (daCTZ) for coelenterazine and of (S)-2- and (R)-2-hydroxymethyl-deaza-CTZ (HM-daCTZ) for 2-peroxycoelenterazine were efficiently prepared by the improvement method. Read More

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1,3,4,5-Tetraamino-1,2,4-triazolium Cation: An Energetic Moiety.

Inorg Chem 2021 Jun 11. Epub 2021 Jun 11.

Department of Materials Engineering, Purdue University, 205 Gates Road, West Lafayette, Indiana 47906, United States.

The amination of 3,4,5-triamino-1,2,4-triazole with -tosylhydroxylamine yielded the nitrogen-rich 1,3,4,5-tetraamino-1,2,4-triazolium cation as its tosylate salt. Subsequent metathesis reactions produced energetic salts with various energetic anions, including perchlorate, nitrate, nitrotetrazolate, and bistetrazolate diolate. All energetic salts possess relatively high heats of formation, thermal sensitivities, and detonation velocities and pressures. Read More

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An unprecedented pyridine-based dinuclear mixed-valent Re oxo-bridged complex: a solvatochromic and AIE-active probe for nanomolar detection of picric acid and trinitrotoluene.

Dalton Trans 2021 Jun 11. Epub 2021 Jun 11.

Department of Chemistry, BITS-Pilani Hyderabad Campus, Hyderabad-500078, India.

This paper describes the synthesis of an unprecedented oxo-bridged rheniumI/VII (Re) complex by treating Re2(CO)10 with a pyridyl-linked anthracene-based twisted π-conjugated ligand. The molecular structures of both the ligand and the complex are determined by analyzing IR, NMR, and HR-MS spectra and unequivocally determined using single-crystal X-ray diffraction studies. Unlike previous observations, the complexation occurs uniquely to yield an unprecedented oxo-bridged ReI/VII complex. Read More

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Sociodemographic and clinical correlates of gabapentin receipt with and without opioids among a national cohort of patients with HIV.

AIDS Care 2021 Jun 11:1-11. Epub 2021 Jun 11.

Yale School of Medicine, New Haven, CT, USA.

Gabapentin is commonly prescribed for chronic pain, including to patients with HIV (PWH). There is growing concern regarding gabapentin's potential for harm, particularly in combination with opioids. Among PWH, we examined factors associated with higher doses of gabapentin receipt and determined if receipt varied by opioid use. Read More

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Synthesis, Characterization and Energetic Performance of Oxalyl Diazide, Carbamoyl Azide, and N,N'-Bis(azidocarbonyl)hydrazine.

Chempluschem 2021 May 28;86(6):870-874. Epub 2021 May 28.

Department of Chemistry, Shanghai Key Laboratory of Molecular Catalysts and Innovative Materials, Fudan University, 200438, Shanghai, P. R. China.

As pure compounds, small carbonyl azides enjoy a bad reputation, due to the high explosive sensitivity and instability they demonstrate. Consequently, most reported examples have only been poorly characterized. The compounds oxalyl diazide (1), carbamoyl azide (2), as well as N,N'-bis(azidocarbonyl)hydrazine (3) were obtained by performing a diazotation reaction on the corresponding hydrazo precursor. Read More

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Structure and Function of the Autolysin SagA in the Type IV Secretion System of .

Mol Cells 2021 Jun 11. Epub 2021 Jun 11.

Department of Agricultural Biotechnology, Research Institute for Agriculture and Life Sciences, Center for Food and Bioconvergence, CALS, Seoul National University, Seoul 08826, Korea.

A recent genetic study with revealed the secretion activator gene A (SagA) as an autolysin component creating pores in the peptidoglycan (PGN) layer for the type IV secretion system (T4SS) and peptidoglycan hydrolase inhibitor A (PhiA) as an inhibitor of SagA. In this study, we determined the crystal structures of both SagA and PhiA. Notably, the SagA structure contained a PGN fragment in a space between the N- and C-terminal domains, showing the substrate-dependent hinge motion of the domains. Read More

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Role of the VirSR-VirAB system in biofilm formation of Listeria monocytogenes EGD-e.

Food Res Int 2021 Jul 8;145:110394. Epub 2021 May 8.

College of Chemistry and Materials Engineering, Xinxiang University, Xinxiang, China.

The ability of Listeria monocytogenes, an important foodborne pathogen, to form biofilms in food processing environments leads to increased opportunity for contamination of food products, which is a major concern for food safety. In this study, the role of a complex system composed of the VirSR two-component signal transduction system (TCS) and the ATP-binding cassette (ABC) transporter VirAB in biofilm formation of L. monocytogenes EGD-e was investigated. Read More

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Rotational Dynamics of an Amphidynamic Zirconium Metal-Organic Framework Determined by Dielectric Spectroscopy.

J Phys Chem Lett 2021 Jun 10:5644-5648. Epub 2021 Jun 10.

Department of Chemistry and Biochemistry, University of California, Los Angeles, California 90095, United States.

A zirconium metal-organic framework with a difluorophenylene rotator bearing a permanent electric dipole of ∼3.2 D was synthesized, and its rotational motion was analyzed by temperature- and frequency-dependent broadband dielectric spectroscopy. While solid-state NMR confirms fast rotation qualitatively, the dissipation factors measured between 113 and 153 K suggested an activation energy = 2. Read More

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Evaluation of the antioxidant, antibacterial, and antibiofilm activity of the sesquiterpene nerolidol.

Arch Microbiol 2021 Jun 10. Epub 2021 Jun 10.

Laboratório de Biologia Molecular, Departamento de Bioquímica, Universidade Federal de Pernambuco (UFPE), Recife, PE, Brazil.

The aim of this study was to evaluate the antioxidant, antibacterial, and antibiofilm activities of nerolidol. The antioxidant activity of nerolidol was determined using the total antioxidant activity method. Antibacterial activity was performed using the microdilution method to determine the minimum inhibitory concentration (MIC) against seven standard strains of the ATCC and four bacterial clinical isolates with a resistance profile, following the Clinical and Laboratory Standards Institute (CLSI). Read More

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Evaluation of dry eye subtypes and characteristics using conventional assessments and dynamic tear interferometry.

Br J Ophthalmol 2021 Jun 9. Epub 2021 Jun 9.

Institute of Vision Research, Department of Ophthalmology, Yonsei University College of Medicine, Seoul, South Korea

Background/aims: To evaluate subtypes and characteristics of dry eye (DE) using conventional tests and dynamic tear interferometry, and to investigate determinants of disease severity in each DE subtype.

Methods: 309 patients diagnosed with DE and 69 healthy controls were prospectively enrolled. All eyes were evaluated using Ocular Surface Disease Index (OSDI), Schirmer's test I (ST1) and Meibomian gland dysfunction (MGD) grade were analysed. Read More

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