80 research outputs found
Impingement-free Hip Motion: The βNormal' Angle Alpha after Osteochondroplasty
Femoroacetabular impingement is considered a cause of hip osteoarthrosis. In cam impingement, an aspherical head-neck junction is squeezed into the joint and causes acetabular cartilage damage. The anterior offset angle Ξ±, observed on a lateral crosstable radiograph, reflects the location where the femoral head becomes aspheric. Previous studies reported a mean angle Ξ± of 42Β° in asymptomatic patients. Currently, it is believed an angle Ξ± of 50Β° to 55Β° is normal. The aim of this study was to identify that angle Ξ± which allows impingement-free motion. In 45 patients who underwent surgical treatment for femoroacetabular impingement, we measured the angle Ξ± preoperatively, immediately postoperatively, and 1year postoperatively. All hips underwent femoral correction and, if necessary, acetabular correction. The correction was considered sufficient when, in 90Β° hip flexion, an internal rotation of 20Β° to 25Β° was possible. The angle Ξ± was corrected from a preoperative mean of 66Β° (range, 45Β°-79Β°) to 43Β° (range, 34Β°-60Β°) postoperatively. Because the acetabulum is corrected to normal first, the femoral correction is tested against a normal acetabulum. We therefore concluded an angle Ξ± of 43Β° achieved surgically and with impingement-free motion, represents the normal angle Ξ±, an angle lower than that currently considered sufficien
DiVA -Digitala Vetenskapliga Arkivet
IR spectra, TG analysis and x-ray diffraction showed a solvated structure for the as-grown C 60 microtubes. Through a gentle heat-treatment in vacuum, pure C 60 microtubes with single crystalline fcc structure were obtained after the elimination of solvents. It is suggested that the C 60 microtubes form through self-assembly from several individual C 60 nanorods
Π Π°ΡΡΠ΅Ρ ΡΠ°ΡΠΏΡΠ΅Π΄Π΅Π»Π΅Π½ΠΈΡ ΠΏΡΠΈΠΌΠ΅ΡΠΈ ΠΈ ΠΏΠΎΡΠΎΠΊΠΎΠ² Π΅Π΅ ΠΌΠΈΠ³ΡΠ°ΡΠΈΠΈ Ρ ΠΊΠ»ΠΈΠ½ΠΎΠ²ΠΈΠ΄Π½ΠΎΠ³ΠΎ Π΄Π²ΠΎΠΉΠ½ΠΈΠΊΠ° Π½Π° ΠΎΡΠ½ΠΎΠ²Π°Π½ΠΈΠΈ ΠΌΠ°ΠΊΡΠΎΡΠΊΠΎΠΏΠΈΡΠ΅ΡΠΊΠΎΠΉ Π΄ΠΈΡΠ»ΠΎΠΊΠ°ΡΠΈΠΎΠ½Π½ΠΎΠΉ ΠΌΠΎΠ΄Π΅Π»ΠΈ
High pressure Raman, IR and X-ray diffraction (XRD) studies have been carried out on C-70(Fe(C5H5)(2))(2) (hereafter, "C-70(Fc)(2)") sheets. Theoretical calculation is further used to analyze the Electron Localization Function (ELF) and charge transfer in the crystal and thus to understand the transformation of C-70(Fc)(2) under pressure. Our results show that even at room temperature dimeric phase and one dimensional (1D) polymer phase of C-70 molecules can be formed at about 3 and 8 GPa, respectively. The polymerization is found to be reversible Upon decompression and the reversibility is related to the pressure-tuned charge transfer, as well as the overridden steric repulsion of counter ions. According to the layered structure of the intercalated ferrocene molecules formed in the crystal, we suggest that ferrocene acts as not only a spacer to restrict the polymerization of C-70 molecules within a layer, but also as charge reservoir to tune the polymerization process. This supplies a possible way for us to design the polymerization of fullerenes at suitable conditions
ΠΡΠ΅Π½ΠΊΠ° ΠΏΠΎΠΌΠ΅Ρ ΠΎΡΡΡΠΎΠΉΡΠΈΠ²ΠΎΡΡΠΈ ΠΌΠ΅ΡΠΎΠ΄Π° Π΄ΠΈΠ°Π³Π½ΠΎΡΡΠΈΠΊΠΈ ΡΠΎΡΠΎΡΠ½ΡΡ ΡΠ·Π»ΠΎΠ² ΠΌΠ°ΡΠΈΠ½ Π² Π·Π°Π²ΠΈΡΠΈΠΌΠΎΡΡΠΈ ΠΎΡ ΡΡΠ»ΠΎΠ²ΠΈΠΉ ΠΏΡΠ΅Π΄Π²Π°ΡΠΈΡΠ΅Π»ΡΠ½ΠΎΠΉ ΡΠΈΠ»ΡΡΡΠ°ΡΠΈΠΈ Π²ΠΈΠ±ΡΠ°ΡΠΈΠΎΠ½Π½ΠΎΠ³ΠΎ ΡΠΈΠ³Π½Π°Π»Π°
ΠΡΠΎΠΈΠ·Π²Π΅Π΄Π΅Π½ΠΎ ΡΡΠ°Π²Π½Π΅Π½ΠΈΠ΅ Π΄Π²ΡΡ
ΡΠΏΠΎΡΠΎΠ±ΠΎΠ² ΠΏΡΠ΅Π΄Π²Π°ΡΠΈΡΠ΅Π»ΡΠ½ΠΎΠΉ ΡΠΈΠ»ΡΡΡΠ°ΡΠΈΠΈ ΠΏΡΠΈ ΠΎΡΠ΅Π½ΠΊΠ΅ ΡΠ΅Ρ
Π½ΠΈΡΠ΅ΡΠΊΠΎΠ³ΠΎ ΡΠΎΡΡΠΎΡΠ½ΠΈΡ ΡΠΎΡΠΎΡΠ½ΡΡ
ΡΠ·Π»ΠΎΠ² ΠΌΠ°ΡΠΈΠ½ ΠΏΠΎ ΠΌΠ΅ΡΠΎΠ΄Ρ Π°Π½Π°Π»ΠΈΠ·Π° ΡΠΏΠ΅ΠΊΡΡΠ° ΠΎΠ³ΠΈΠ±Π°ΡΡΠ΅ΠΉ Π²ΠΈΠ±ΡΠ°ΡΠΈΠΎΠ½Π½ΠΎΠ³ΠΎ ΡΠΈΠ³Π½Π°Π»Π°. ΠΠΏΡΠ΅Π΄Π΅Π»Π΅Π½Π° ΠΏΠΎΠΌΠ΅Ρ
ΠΎΡΡΡΠΎΠΉΡΠΈΠ²ΠΎΡΡΡ ΠΌΠ΅ΡΠΎΠ΄Π° ΠΏΡΠΈ Π²ΠΎΠ·Π΄Π΅ΠΉΡΡΠ²ΠΈΠΈ ΡΠΈΡΠΎΠΊΠΎΠΏΠΎΠ»ΠΎΡΠ½ΡΡ
ΡΡΠΌΠΎΠ².ditions of Prefiltration of the Vibration Signal
The comparison of the two methods of prefiltration during evaluation of technical condition of the machine rotor units is performed in the paper using the method of the analysis of the spectrum of the vibration waveform envelope. Noise stability of the method under the action of broadband noise is determined
Etiologic Classification Criteria of ARCO on Femoral Head Osteonecrosis Part 1: Glucocorticoid-Associated Osteonecrosis.
BACKGROUND: Glucocorticoid usage, a leading cause of osteonecrosis of the femoral head (ONFH), and its prevalence was reported in 25%-50% of non-traumatic ONFH patients. Nevertheless, there have been no unified criteria to classify glucocorticoid-associated ONFH (GA-ONFH). In 2015, the Association Research Circulation Osseous addressed the issue of developing a classification scheme. METHODS: In June 2017, a task force was set up to conduct a Delphi survey concerning ONFH. The task force invited 28 experts in osteonecrosis/bone circulation from 8 countries. Each round of the Delphi survey consists of questionnaires, analysis of replies, and feedback reports to the panel. After 3 rounds of the survey, the panel reached a consensus on the classification criteria. The response rates were 100% (Round 1), 96% (Round 2), and 100% (Round 3), respectively. RESULTS: The consensus on the classification criteria of GA-ONFH included the following: (1) patients should have a history of glucocorticoid use >2 g of prednisolone or its equivalent within a 3-month period; (2) osteonecrosis should be diagnosed within 2 years after glucocorticoid usage, and (3) patients should not have other risk factor(s) besides glucocorticoids. CONCLUSION: Association Research Circulation Osseous established classification criteria to standardize clinical studies concerning GA-ONFH
Etiologic Classification Criteria of ARCO on Femoral Head Osteonecrosis Part 2: Alcohol-Associated Osteonecrosis.
BACKGROUND: Although alcohol is a leading risk factor for osteonecrosis of the femoral head (ONFH) and its prevalence reportedly ranges from 20% to 45%, there are no unified classification criteria for this subpopulation. In 2015, Association Research Circulation Osseous decided to develop classification criteria for alcohol-associated ONFH. METHODS: In June of 2017, Association Research Circulation Osseous formed a task force to conduct a Delphi survey. The task force invited 28 experts in osteonecrosis/bone circulation from 8 countries. Each round of the Delphi survey included questionnaires, analysis of replies, and feedback reports to the panel. After 3 rounds of the survey, consensus was reached on the classification criteria. The response rates for the 3 Delphi rounds were 100% (round 1), 96% (round 2), and 100% (round 3). RESULTS: The consensus on the classification criteria of alcohol-associated ONFH included the following: (1) patients should have a history of alcohol intake >400 mL/wk (320 g/wk, any type of alcoholic beverage) of pure ethanol for more than 6 months; (2) ONFH should be diagnosed within 1 year after alcohol intake of this dose; and (3) patients should not have other risk factor(s). CONCLUSION: ARCO-established classification criteria to standardize clinical studies concerning AA-ONFH
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