145 research outputs found
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Associations of Dietary Calcium and Phosphorus With Vascular and Valvular Calcification: The ARIC Study.
BackgroundHigh dietary calcium and phosphorus may accelerate vascular calcification, but epidemiological data are inconsistent. Most of those studies assessed diet at one point and have not been systematically evaluated.ObjectivesThe purpose of this study was to assess the associations of dietary calcium and phosphorus intakes in middle age with coronary artery and extra-coronary calcification at older age.MethodsWe studied 1,914 participants from the ARIC (Atherosclerosis Risk In Communities) study (mean age 80.5 years) without coronary heart disease who underwent chest computed tomography scans at visit 7 (2018-2019) and completed a 66-item food frequency questionnaire at 2 earlier visits (visit 1 [1987-1989] and visit 3 [1993-1995]). Dietary calcium and phosphorus intakes were averaged between these 2 visits. Calcification was quantified by the Agatston score in coronary artery, ascending aorta, descending aorta, aortic valve ring, aortic valve, and mitral valve.ResultsDietary calcium intake was inversely associated with coronary artery and ascending aorta calcification, whereas the association was not significant for other measures of extra-coronary calcification. For example, the highest vs lowest quartile of calcium intake showed an adjusted OR of 0.66 (95% CI: 0.45-0.98) for coronary artery calcification (Agatston score ≥75th percentile). Dietary phosphorus intake demonstrated similar results, but the magnitude of the association was weaker than dietary calcium intake.ConclusionsDietary calcium and phosphorus intakes at middle age were not positively associated with vascular and valvular calcification at over 75 years old. Our findings did not support the link between a calcium or phosphorus-rich diet and vascular and valvular calcification
Minimally Invasive Surgical Approaches and Traditional Total Hip Arthroplasty: A Meta-Analysis of Radiological and Complications Outcomes
BACKGROUND: Minimally invasive total hip arthroplasty (MITHA) remains considerably controversial. Limited visibility and prosthesis malposition increase the risk of post-surgical complications compared to those of the traditional method. METHODS: A meta-analysis was undertaken of all published databases up to May 2011. The studies were divided into four subgroups according to the surgical approach taken. The radiological outcomes and complications of minimally invasive surgery were compared to traditional total hip arthroplasty (TTHA) using risk ratio, mean difference, and standardized mean difference statistics. RESULTS: In five studies involving the posterolateral approach, no significant differences were found between the MITHA groups and the TTHA groups in the acetabular cup abduction angle (p = 0.41), acetabular anteversion (p = 0.96), and femoral prosthesis position (p = 0.83). However, the femoral offset was significantly increased (WMD = 3.00; 95% CI, 0.40-5.60; p = 0.02). Additionally, there were no significant differences among the complications in both the groups (dislocations, nerve injury, infection, deep vein thrombosis, proximal femoral fracture) and revision rate (p>0.05). In three studies involving the posterior approach, there were no significant differences in radiological outcomes or all other complications between MITHA or TTHA groups (p>0.05). Three studies involved anterolateral approach, while 2 studies used the lateral approach. However, the information from imaging and complications was not adequate for statistical analysis. CONCLUSIONS: Posterior MITHA seems to be a safe surgical procedure, without the increased risk of post-operative complication rates and component malposition rates. The posterolateral approach THA may lead to increased femoral offset. The current data are not enough to reach a positive conclusion that lateral and anterolateral approaches will result in increased risks of adverse effects and complications at the prosthesis site
Tandem diastereo- and enantioselective preparation of aryl and alkyl cyclopropyl carbinols with three adjacent stereocenters using perhydrobenzoxazines and diethylzinc
Pharmacokinetic aspects of retinal drug delivery
Drug delivery to the posterior eye segment is an important challenge in ophthalmology, because many diseases affect the retina and choroid leading to impaired vision or blindness. Currently, intravitreal injections are the method of choice to administer drugs to the retina, but this approach is applicable only in selected cases (e.g. anti-VEGF antibodies and soluble receptors). There are two basic approaches that can be adopted to improve retinal drug delivery: prolonged and/or retina targeted delivery of intravitreal drugs and use of other routes of drug administration, such as periocular, suprachoroidal, sub-retinal, systemic, or topical. Properties of the administration route, drug and delivery system determine the efficacy and safety of these approaches. Pharmacokinetic and pharmacodynamic factors determine the required dosing rates and doses that are needed for drug action. In addition, tolerability factors limit the use of many materials in ocular drug delivery. This review article provides a critical discussion of retinal drug delivery, particularly from the pharmacokinetic point of view. This article does not include an extensive review of drug delivery technologies, because they have already been reviewed several times recently. Instead, we aim to provide a systematic and quantitative view on the pharmacokinetic factors in drug delivery to the posterior eye segment. This review is based on the literature and unpublished data from the authors' laboratory.Peer reviewe
Iron (III) Salalen Complexes for the Polymerisation of Lactide
Herein, we report the preparation and characterisation of iron (III) salalen complexes, with variation of ligand substituents and backbone investigated. Six new complexes were prepared and characterised by elemental analysis, mass spectrometry and X-ray crystallography. These complexes have been applied for the ring opening polymerisation (ROP) of rac-lactide in propylene oxide. Fe(1)Cl was found to have a moderate isotactic preference (Pm = 0.75 – 0.80) and demonstrated good molecular weight control in solution (Đ = 1.02 – 1.18). Fe(2-7)Cl were also active for ROP and activities could be related to ligand structure
Stable N-heterocyclic carbene (NHC)-palladium(0) complexes as active catalysts for olefin cyclopropanation reactions with ethyl diazoacetate
The Pd(0) complexes
NHCPdLn (NHC = N-heterocyclic
carbene ligand; L = styrene for n = 2 or
PR3 for n = 1) efficiently catalyze the
olefin cyclopropanation using ethyl
diazoacetate (EDA) as the carbene
source with activities that improve any
other previous described catalytic
system based on this metal.
Mechanistic studies have shown that all
those catalyst precursors deliver in
solution the same catalytic species
(IPr)Pd(sty), a 14e, unsaturated
intermediate that further reacts with
EDA to afford (IPr)Pd(=CHCO2Et)(sty),
from which cyclopropane is formed.We thank Prof. P. J. Pérez (Univ. Huelva) for helpful and constructive comments on these studies. We thank the Ministerio de Ciencia e Innovación (grants CTQ2008–00042BQU and CTQ2011–24502) and the Junta de Andalucía (Proyecto P07-FQM-02794) for financial support. CM thanks the MEC for a research fellowshipWe thank Prof. P.J. Perez (Univ. Huelva) for helpful and constructive comments on these studies. We thank the Ministerio de Ciencia e Innovacion (grants CTQ2008-00042BQU and CTQ2011-24502) and the Junta de Andalucia (Proyecto P07-FQM-02794) for financial support. CM thanks the MEC for a research fellowship
Comparison the of Radiographic and Clinical Results Between Conservative and Conventional Femoral Components in Total Hip Arthroplasty
Asymmetric Epoxidation Using Aqueous Hydrogen Peroxide as Oxidant: Bio-Inspired Construction of Pentacoordinated Mn—Salen Complexes and Their Catalysis.
Messungsresultate der Grosse und Lange der Zahnreihe der Japanischen Junglingen mit Berucksichtigung an der Blutgruppen
Synthesis of Metal—(Pentadentate-Salen) Complexes: Asymmetric Epoxidation with Aqueous Hydrogen Peroxide and Asymmetric Cyclopropanation (salenH2: N,N′-Bis(salicylidene)ethylene-1,2-diamine).
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