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https://www.readbyqxmd.com/read/29218684/feasibility-of-arthroscopic-autologous-chondrocyte-implantation-in-the-hip-using-an-injectable-hydrogel
#1
Steffen Thier, Florian Baumann, Christel Weiss, Stefan Fickert
INTRODUCTION: In the long term the treatment of articular cartilage defects of the hip has the most direct impact on the postoperative outcome and should diminish degenerative changes caused by different pathologies. The purpose of this prospective feasibility study is to describe technical aspects of arthroscopic, injectable autologous chondrocyte implantation in the hip and to report the short-term outcome. METHODS: Full-thickness cartilage defects of 13 patients were treated arthroscopically with an injectable autologous chondrocyte transplantation product (Novocart Inject, Tetec) in a 2-step surgical procedure...
December 8, 2017: Hip International: the Journal of Clinical and Experimental Research on Hip Pathology and Therapy
https://www.readbyqxmd.com/read/29216704/-prevalence-of-x-ray-signs-of-femoroacetabular-impingement-in-mexican-population
#2
R Gutiérrez-Ramos, S A Ávalos-Calderón, L A Bahena-Peniche
BACKGROUND: Femoroacetabular impingement (FAI) is a suggested diagnosis for pain in the hip in the absence of other apparent causes. It is thought to be a cause of progressive arthrosis of the hip. Our objective was to determine the prevalence of radiographic data of FAI in the adult population without hip pathology over a period of six months. MATERIAL AND METHODS: Analytical, observational, multicentric, ambispective and transverse study based on digital X-rays analysis...
May 2017: Acta Ortopédica Mexicana
https://www.readbyqxmd.com/read/29193522/carbonylative-coupling-of-alkyl-zinc-reagents-with-benzyl-bromides-catalyzed-by-an-nn2-pincer-ligand-nickel-complex
#3
Troels Skrydstrup, Thomas Andersen, Aske Donslund, Karoline Neumann
An efficient catalytic protocol for the three-component assembly of benzyl bromides, carbon monoxide and alkyl zinc reagents to benzyl alkyl ketones is described, representing the first Ni-catalyzed carbonylative coupling of two sp3-carbon fragments. The method, which relies on the application of NN2-type pincer ligand nickel complexes and a controlled release of CO gas from a solid precursor, works well with a range of benzylic bromides. Mechanistic studies suggest the intermediacy of carbon-centered radicals...
November 29, 2017: Angewandte Chemie
https://www.readbyqxmd.com/read/29193483/isomerization-of-allylic-alcohols-to-ketones-catalyzed-by-well-defined-iron-pnp-pincer-catalysts
#4
Tian Xia, Zhihong Wei, Brian Spiegelberg, Haijun Jiao, Sandra Hinze, Johannes Gerardus de Vries
Fe(PNP)(CO)HCl (PNP = di-(2-diisopropylphosphanyl-ethyl)amine), activated in situ with KOtBu, is a highly active catalyst for the isomerization of allylic alcohols to ketones without external hydrogen supply. High rates were obtained at 80 °C but the catalyst is also sufficiently active at room temperature with most substrates. The reaction follows a self-hydrogen-borrowing mechanism as verified by DFT calculations. An alternative isomerization via alkene insertion and beta-hydride elimination could be excluded on the basis of the much higher barrier...
November 29, 2017: Chemistry: a European Journal
https://www.readbyqxmd.com/read/29192931/homo-and-copolymerization-of-norbornene-with-tridentate-nickel-complexes-bearing-o-aryloxide-n-heterocyclic-carbene-ligands
#5
Dandan Yang, Jie Dong, Baiquan Wang
A series of new pincer-type tridentate o-aryloxide-N-heterocyclic carbene nickel complexes Ni1-Ni3 were synthesized, and the molecular structure of Ni3 was confirmed by X-ray crystallography. In comparison with the above tridentate complexes, the bidentate bis(aryloxide-NHC) nickel complex Ni4 was also synthesized. On activation with either Et2AlCl or Me2AlCl, all nickel complexes showed low activity toward norbornene (NB) homopolymerization. Surprisingly, Ni1-Ni3 catalysts exhibited moderate to high activity toward the homopolymerization (up to 3...
December 1, 2017: Dalton Transactions: An International Journal of Inorganic Chemistry
https://www.readbyqxmd.com/read/29192786/synthesis-of-2-pyridinemethyl-ester-derivatives-from-aldehydes-and-2-alkylheterocycle-n-oxides-via-copper-catalyzed-tandem-oxidative-coupling-rearrangement
#6
Chang-Sheng Wang, Thierry Roisnel, Pierre H Dixneuf, Jean-François Soulé
Successful benzylic C(sp3)-H acyloxylation of 2-alkylpyridine, 2-alkylpyrazine, and 2-alkylthiazole compounds was achieved using simple aldehydes. This was carried out via a copper-catalyzed tandem reaction, involving oxidative esterification followed by O-atom transfer of the resultant high yield formed Boekelheide intermediate. The method enables the preparation of functional heterocycles and the desymmetrization of 2,6-dialkylpyridines for efficient synthesis of dissymmetric pincer ligands, thus offering a new life for more practical Boekelheide rearrangement...
December 1, 2017: Organic Letters
https://www.readbyqxmd.com/read/29190108/palladium-catalyzed-oxidative-borylation-of-allylic-c-h-bonds-in-alkenes
#7
Lujia Mao, Rüdiger Bertermann, Simon G Rachor, Kálmán J Szabó, Todd B Marder
This communication describes an efficient palladium pincer complex-catalyzed allylic C-H borylation of alkenes. The transformation exhibits high regio- and stereoselectivity with a variety of linear alkenes. A synthetically useful feature of this allylic C-H borylation method is that all allyl-Bpin products can be isolated in usually high yields. Preliminary mechanistic studies indicate that this C-H borylation reaction proceeds via Pd(IV) pincer complex intermediates.
November 30, 2017: Organic Letters
https://www.readbyqxmd.com/read/29188260/no%C3%AB-disproportionation-by-a-rhno-9-pincer-type-complex
#8
Carina Gaviglio, Juan Pellegrino, David Milstein, Fabio Doctorovich
The reactivity of the {RhNO}9 complex [Rh(PCPtBu)(NO)]˙ (1˙) with NO˙ was studied. A disproportionation reaction takes place in which N2O is released quantitatively, while the complex Rh(PCPtBu)(NO)(NO2) (2), with coordinated nitrite, is formed. The new complex 2 was fully characterized by multinuclear NMR techniques, IR and X-ray diffraction. The X-ray structure reveals a square pyramidal geometry with an N-bound nitro ligand trans to the Cipso of the PCP ligand and a bent nitrosyl ligand in the apical position...
November 30, 2017: Dalton Transactions: An International Journal of Inorganic Chemistry
https://www.readbyqxmd.com/read/29176716/a-rapidly-reversible-absorptive-and-emissive-vapochromic-pt-ii-pincer-based-chemical-sensor
#9
M J Bryant, J M Skelton, L E Hatcher, C Stubbs, E Madrid, A R Pallipurath, L H Thomas, C H Woodall, J Christensen, S Fuertes, T P Robinson, C M Beavers, S J Teat, M R Warren, F Pradaux-Caggiano, A Walsh, F Marken, D R Carbery, S C Parker, N B McKeown, R Malpass-Evans, M Carta, P R Raithby
Selective, robust and cost-effective chemical sensors for detecting small volatile-organic compounds (VOCs) have widespread applications in industry, healthcare and environmental monitoring. Here we design a Pt(II) pincer-type material with selective absorptive and emissive responses to methanol and water. The yellow anhydrous form converts reversibly on a subsecond timescale to a red hydrate in the presence of parts-per-thousand levels of atmospheric water vapour. Exposure to methanol induces a similarly-rapid and reversible colour change to a blue methanol solvate...
November 27, 2017: Nature Communications
https://www.readbyqxmd.com/read/29172520/copper-i-chelators-for-alzheimer-s-disease
#10
Stanley Opare, Arvi Rauk
A component of the neurotoxicity of the beta amyloid peptide (Aβ) of Alzheimer's disease is its ability to generate superoxide, hydrogen peroxide and hydroxyl radicals by the reaction of its reduced copper complex, Aβ/Cu+ has with molecular oxygen. The objective of the present work was to devise compounds, L, that could remove Cu+ from Aβ/Cu+, with the property that L/Cu+ itself would not be capable of reducing O2 or hydrogen peroxide. We show by density functional calculations that several pincer-type compounds with two imidazole rings and a sulphur or nitrogen, have the desired combination of Cu+ binding affinity and Cu2+ reduction potential...
November 27, 2017: Journal of Physical Chemistry. B
https://www.readbyqxmd.com/read/29172476/correction-to-modular-attachment-of-appended-boron-lewis-acids-to-a-ruthenium-pincer-catalyst-metal-ligand-cooperativity-enables-selective-alkyne-hydrogenation
#11
Kuei-Nin T Tseng, Jeff W Kampf, Nathaniel K Szymczak
No abstract text is available yet for this article.
November 27, 2017: Journal of the American Chemical Society
https://www.readbyqxmd.com/read/29164732/cobalt-pincer-complexes-for-catalytic-reduction-of-carboxylic-acid-esters
#12
Kathrin Junge, Bianca Wendt, Andrea Cingolani, Anke Spannenberg, Zhihong Wei, Haijun Jiao, Matthias Beller
A selection of cobalt(I) and cobalt(II) pincer type complexes with different substitution patterns was tested in the catalytic reduction of carboxylic acid esters to alcohols. The cobalt pincer type complex 4 is suitable for the hydrogenation of aromatic as well as aliphatic and cyclic esters. Mechanistic investigation indicated a metal ligand cooperated reaction pathway.
November 22, 2017: Chemistry: a European Journal
https://www.readbyqxmd.com/read/29164164/female-sex-is-a-risk-factor-for-failure-of-hip-arthroscopy-performed-for-acetabular-retroversion
#13
Kirsten L Poehling-Monaghan, Aaron J Krych, Bruce A Levy, Robert T Trousdale, Rafael J Sierra
Background: The success of hip surgery in treating acetabular retroversion depends on the severity of the structural deformity and on selecting the correct patient for open or arthroscopic procedures. Purpose: To compare a group of patients with retroverted hips treated successfully with hip arthroscopy with a group of patients with retroverted hips that failed arthroscopic surgery, with special emphasis on (1) patient characteristics, (2) perioperative radiographic parameters, (3) intraoperative findings and concomitant procedures, and (4) patient sex...
November 2017: Orthopaedic Journal of Sports Medicine
https://www.readbyqxmd.com/read/29162364/is-there-an-association-between-noncontact-anterior-cruciate-ligament-injuries-and-decreased-hip-internal-rotation-or-radiographic-femoroacetabular-impingement-a-systematic-review
#14
REVIEW
Nickolas Boutris, Rory A Byrne, Domenica A Delgado, Timothy E Hewett, Patrick C McCulloch, David M Lintner, Joshua D Harris
PURPOSE: To perform a systematic review to determine if there is (1) an association between decreased hip internal rotation and anterior cruciate ligament (ACL) tear rates; (2) an association between radiographic femoroacetabular impingement (FAI) and ACL tear rates; and (3) biomechanical evidence demonstrating increased strain in the ACL of patients with decreased hip internal rotation. METHODS: A systematic review was performed using Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines...
November 18, 2017: Arthroscopy: the Journal of Arthroscopic & related Surgery
https://www.readbyqxmd.com/read/29157844/prevalence-of-asymptomatic-femoroacetabular-impingement-in-turkey-cross-sectional-study
#15
Gökhan Polat, Koray Şahin, Ufuk Arzu, Alper Şükrü Kendirci, Mehmet Aşık
OBJECTIVES: Femoroacetabular impingement (FAI) is one of the causes of hip pain in young-adult patients. The purpose of our study is to determine the prevalence of radiological FAI findings in asymptomatic population in Turkey. METHODS: Trauma patients aged 18-65 years who applied to the emergency service between September 2015 and September 2016 were retrospectively evaluated for this study. After a preliminary study and power analysis, 2152 hips of the 1076 previously asymptomatic patients were evaluated radiologically with pelvis antero-posterior and frog-leg radiographs...
November 17, 2017: Acta Orthopaedica et Traumatologica Turcica
https://www.readbyqxmd.com/read/29148744/the-fundamental-noninnocent-role-of-water-for-the-hydrogenation-of-nitrous-oxide-by-pnp-pincer-ru-based-catalysts
#16
Jesús A Luque-Urrutia, Albert Poater
The hydrogenation of nitrous oxide by PNP pincer ruthenium complexes supposes a promising way to functionalize a hazardous gas and reduce the greenhouse effect, generating dinitrogen and water. Here, by DFT calculations we describe not only the whole mechanism for such a green transformation but we unravel the fundamental role of water, without which the reaction could not go forward. Water assists mandatorily in the H transfer to generate the hydroxyl group together with the release of dinitrogen.
November 17, 2017: Inorganic Chemistry
https://www.readbyqxmd.com/read/29140603/protic-nnn-and-ncn-pincer-type-ruthenium-complexes-featuring-trifluoromethyl-pyrazole-arms-synthesis-and-application-to-catalytic-hydrogen-evolution-from-formic-acid
#17
Yoshiko Nakahara, Tatsuro Toda, Asuka Matsunami, Yoshihito Kayaki, Shigeki Kuwata
The NNN and NCN pincer-type ruthenium(II) complexes featuring two protic pyrazol-3-yl arms with a trifluoromethyl (CF3) group at the 5-position were synthesized and structurally characterized to evaluate the impact of the substitution on the properties and catalysis. The Brønsted acidity increased by the highly electron-withdrawing CF3 pendants was demonstrated by the protonation-deprotonation experiments. By contrast, the infrared spectra of the carbonyl derivatives as well as the cyclic voltammogram indicated that the electron density of the ruthenium atom is little influenced by the CF3 group...
November 15, 2017: Chemistry, An Asian Journal
https://www.readbyqxmd.com/read/29136075/coordinatively-and-electronically-unsaturated-square-planar-cobalt-iii-complexes-of-a-pyridine-dianionic-pincer-ligand
#18
Faidh Hana, Alan J Lough, Gino G Lavoie
A series of low-valent Co(iii) square planar complexes supported by a dianionic pincer ligand bis(arylamido)pyridine ([NNN](2-)) was synthesized, including the first structurally characterized square planar hydroxide complex ([NNN]Co(OH), 4) of a 3d transition metal in the +3 oxidation state. The magnetic properties of the Co(iii) complexes were highly dependent on the charge of the complex and on the coordination environment of the metal. The diamagnetic cationic complex {[NNN]Co(py)}BF4 (2) can be converted to neutral paramagnetic complexes [NNN]Co(OR) (R = Ph 3a, iPr 3b, and H 4) by a simple substitution of the ancillary pyridine ligand in 2...
November 14, 2017: Dalton Transactions: An International Journal of Inorganic Chemistry
https://www.readbyqxmd.com/read/29120616/redox-noninnocent-azo-aromatic-pincers-and-their-iron-complexes-isolation-characterization-and-catalytic-alcohol-oxidation
#19
Suman Sinha, Siuli Das, Rina Sikari, Seuli Parua, Paula Brandaõ, Serhiy Demeshko, Franc Meyer, Nanda D Paul
The new redox-noninnocent azoaromatic pincers 2-(arylazo)-1,10-phenanthroline (L(1)) and 2,9-bis(phenyldiazo)-1,10-phenanthroline (L(2)) are reported. The ligand L(1) is a tridentate pincer having NNN donor atoms, whereas L(2) is tetradentate having two azo-N donors and two N-donor atoms from the 1,10-phenanthroline moiety. Reaction of FeCl2 with L(1) or L(2) produced the pentacoordinated mixed-ligand Fe(II) complexes FeL(1)Cl2 (1) and FeL(2)Cl2 (2), respectively. Homoleptic octahedral Fe(II) complexes, mer-[Fe(L(1))2](ClO4)2 [3](ClO4)2 and mer-[Fe(L(2))2](ClO4)2 [4](ClO4)2, have been synthesized from the reaction of hydrated Fe(ClO4)2 and L(1) or L(2)...
November 9, 2017: Inorganic Chemistry
https://www.readbyqxmd.com/read/29112800/the-association-of-femoroacetabular-impingement-and-delayed-gadolinium-enhanced-mri-of-cartilage-dgemric-a-population-based-study
#20
Yimeng Guo, Honglin Zhang, Hong Qian, David R Wilson, Hubert Wong, Morgan Barber, Bruce B Forster, John Esdaile, Jolanda Cibere
OBJECTIVE: 1) To assess the association of FAI and dGEMRIC T1 relaxation values (RV). 2) To evaluate whether subtypes of FAI (cam, pincer, mixed) are associated with region-specific dGEMRIC T1 RVs. METHODS: A population-based sample of Caucasian subjects with and without hip pain, aged 20-49, was selected through random digit dialing. A sample of 128 subjects underwent hip joint 3T dGEMRIC scans. Radiographic cam FAI was defined as an alpha angle >55°, while pincer FAI was defined by a lateral center edge angle >40° or a positive cross-over sign...
November 7, 2017: Arthritis Care & Research
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