Investigation on Spectral Characteristic and Threshold Behavior of Network Structure of Ge-Sb-S Chalcogenide Glasses.

Two series of chalcogenide glasses in Ge-Sb-S ternary system were synthesized with melt-quenching method. The phycochemical properties and spectral characteristic of glasses with different content of Ge and Sb were obtained with a series of measurements, and the systematic analysis on the change of optical properties was conducted in terms of microstructure of glasses combined with the Raman spectra. With constraint theory based on mean coordination number (Z), we described the variation trend of network structure directly. It was found that as long as the value of Z reaches 2.6, new vibration peaks would be formed in the Raman spectra indicating the presence of threshold behavior as well as the change of the network structure of the Ge-Sb-S glasses which could be expressed in a specific varition in the number of metal bonds and the nonmetal bonds. The appearance of new functional groups in the network have changed the total bond energy of glasses, and then affected the energy band structure of glasses representing the corresponding threshold behavior of the value of optical band gap (Eopg).

[Case-control study on clinical effects of arthroscopic single-versus double-bundle ACLs reconstructions].

OBJECTIVE: To compare the clinical results of arthroscopic single and double-bundle ACLs reconstructions. METHODS: From January 2009 to May 2010,45 patients with anterior cruciate ligament tear were divided into two groups. In the first group,the anterior cruciate ligament were anatomical reconstructed with double-bundle semitendinous tendon, and in the second group the anterior cruciate ligaments were anatomical reconstrucated with single bundle semitendinous tendon. There were 22 patients (15 males and 7 females) in double-bundle group, with an average age of (27.04 +/- 3.68) years; 18 patients (13 males and 5 females) in single bundle group, with an average age of (28.16 +/- 4.76) years. Therapeutic effects between two groups were compared according to the IKDC, Lysholm scoring standards and Lachman test, knee pivot shift test, KT-1000. RESULTS: Twenty-two patients in double-bundle group and 18 patients in single-bundle group were followed-up, and the mean duration was 12 months. The IKDC score of patients in single-bundle group improved from preoperative 41.40 +/- 6.30 to postoperatively 95.70 +/- 3.10, Lysholm score increased from preoperative 47.20 +/- 6.30 to postoperative 94.20 +/- 2.40. And the IKDC score of patients in double-bundle group improved from preoperative 40.90 +/- 6.10 to postoperative 96.10 +/-3.40, Lysholm score increased from preoperative 48.10 +/- 6.50 to postoperative 95.10 +/- 2.49. There was no statistically significant difference between the two groups. The Lachman test was positive in 2 patients (1 patient in double-bundle group and 1 patient in single-bundle group); and pivot shift test was positive in 2 patients (1 patient in double-bundle group and 1 patient in single-bundle group). KT-1000 of patients in double-bundle group was (1.5 +/- 1.2) mm, and (1.9 +/- 1.5) mm in single-bundle group, there were no statistically significant differences between the two groups. CONCLUSION: Arthroscopic single-bundle reconstruction and double-bundle anterior cruciate ligament reconstruction have no significant differences in clinical effects.

[Mid-infrared emission properties of Ho3+/Tm(3+)-codoped Ge-Ga-S-CsI glasses].

A serial of chalcogenide glasses based on 78GeS2-12Ga2S3-10CsI (in molar%) system doped with the different radios of Ho3+/Tm3+ ions were synthesized by melt-quenching method. Their absorption spectra and mid-infrared fluorescence under 808 nm laser excitation were measured. According to Judd-Ofelt theory, the intensity parameters omega(i) (i = 2, 4, 6), spontaneous transition probabilities A(rad) and radiative lifetomes tau(r) for Ho3+ ion were calculated. Absorption cross-sections sigma(a), emission cross-sections sigma(e) and gain coefficient G(lambda) corresponding to the emission of Ho3+ ions at 2.0 microm were obtained. By changing the Tm3+ concentration, the energy transfer regime of Tm3+ and Ho3+ ions under 808 nm excitation was investigated. The results show that Ho3+/Tm(3+)-codoped Ge-Ga-S-CsI glasses would be a potential material for 2.0 microm emission.

[Energy transfer and mid-infrared luminescence properties of Tm3+ /Dy3+ codoped chalcohalide glasses].

A series of chalcohalide glasses based on the composition 0.9 (Ge25 Ga5 S70)-0.1CsI doped with the different Tm3+ / Dy3+ ions ratio were synthesized by melt-quenching technique. The absorption spectra, and mid-infrared fluorescence of different glass samples under 800 nm laser excitation were measured. The results prove that, Tm3+ is an efficient sensitizer, which can enhance the Dy3+ : 2.9 microm fluorescence intensity significantly. A decrease in the intensity of 1.8 microm fluorescence and lifetimes of the Tm3+ : (3)F4 level occurred with increasing the concentration of Dy3+ ions from 0 to 1 Wt% where Tm3+ concentration was fixed to 0.5 Wt%. Also a wide spectral overlap between Tm+ : 1.8 microm emission and the absorption of Dy3+ : 6 H(15/2) --> (6)H(11/2) showed that the effective energy transfer between the two rare-earth ions was mainly attributed to the resonance energy from Tm3+: (3)F4 to Dy(3)+ : (6)H(11/2) level.

[Mid-infrared emission and multiphonon relaxation in Tm3+-doped Ge-Ga-Se glasses].

A series of chalcogenide glasses based on the composition Ge30 Ga5 Se65 (at. %) doped with the different Tm3+ ions were synthesized by melt-quenching technique. The refractive indexes, Raman spectra, absorption spectra, near-and mid-infrared fluorescence, and lifetimes of glass samples under 800 nm laser excitation were measured. The intensity parameters omega(i) (i = 2, 4, 6), transition probabilities, branching ratios and radiative lifetimes have been predicted for Tm3+ ions in samples by using the Judd-Ofelt theory. The near-infrared emission spectra at 1.23, 1.48 and 1.8 microm were observed and their quantum efficiencies were evaluated respectively in glass doped with 1 Wt% Tm(3+)-ions under 800 nm excitation. The mid-infrared fluorescence spectra were investigated with the different Tm3+ ion concentration under 800 nm excitation. The multiphonon relaxation rate of Tm3+ : 3 H5 --> 3F4 by the measured and calculated lifetimes, and the relative parameters of W(0) and a in Ge30 Ga5 Se65 glass were evaluated. Results show that the multiphonon relaxation rates were significantly lower than other glasses due to the lower maximum phonon energy, so the selenide glasses are promising as host materials for doping by rare earth ions and for preparation of mid-infrared optical elements.

[Comparison of the relativity of MRI appearance of cartilage injuries and postoperative effect of arthroscope on articular cartilage disease of knee].

OBJECTIVE: To analyze the indication of arthroscope by examining the correlations between cartilage injury degree confirmed by MRI and postoperative effect. METHODS: From Aug. 2005 to April 2008, 87 cases with knee osteoarthritis were treated by arthroscopes including 44 males and 43 females,aged from 16 to 67 years (means 46.3 years). Arthrodial cartilage of knee was graded by ICRS MR, and the therapeutic effect was evaluated by Lysholm scoring. RESULTS: All 87 knees of 87 cases were followed-up for from 12 to 30 months (averaged 23 months). The cartilage injury degree of knees was graded as follows: grade 4 in 30 cases, grade 3 in 23 cases, grade 2 in 20 cases, grade 1 in 12 cases, grade 0 in 2 cases, means grade (2.770 +/- 1.138). Postoperative Lysholm score was from 59 to 100, means (95.170 +/- 7.556). Coefficient correlation (r) = -0.152, P = 0.159 > 0.05. Although the results had no correlations between cartilage injury degree and Lysholm score, negative correlation tendency existed. CONCLUSION: The patients with higher grade of knee cartilage injury degree confirmed by MRI (1.5T) have worse effect after operation, the grade is not a gold standard as a operation indication in arthroscopic procedure.

[Study on the correlation between knee osteoarthritis imaging and effects of arthroscope].

OBJECTIVE: To explore the indications of arthroscope for the treatment of knee osteoarthritis and investigate the correlation between knee osteoarthritis imaging and effects of arthroscope. METHODS: From 2005.8 to 2008.4, 86 patients with knee osteoarthritis underwent arthroscope examination and treatment. Among the patients, 44 patients were male, and 42 patients were female, ranging in age from 46 to 67 years, averaged 56.3 years. Arthrodial cartilage of knee was graded by ICRS MR, and by Kellgern Laqrence X-ray. All the patients were followed up, and the duration ranged from 12 to 30 months. The Lysholm score was evaluated at the follow-up time. RESULTS: Among 86 knees in 86 cases, cartilage injury degree of knees was graded as follows: grade 4 in 30 cases, grade 3 in 22 cases, grade 2 in 20 cases, grade 1 in 12 cases, grade 0 in 2 cases, mean grade (2.77 +/- 1.138). Postoperative Lysholm score ranged from 59 to 100, averaged (95.17 +/- 7.556), Kendall's correlation coefficient was -0.089, P = 0.317. There was no correlations between cartilage injury degree and Lysholm score. X-ray of knees was graded as follows: grade 4 in 0 cases, grade 3 in 24 cases, grade 2 in 38 cases, grade 1 in 17 cases, grade 0 in 7 cases, mean grade was (2.13 +/- 0.67), the Kendall's correlation coefficient was -0.851 with negative correlations (P = 0.036) between postoperative Lysholm score and K/L grade. CONCLUSION: There is no correlation between the grade of knee cartilage injury confirmed by MRI (1.5T) and effects of arthroscopy, and the grade is not a gold standard as an operation indication in arthroscope procedure. The K/L grade in X-ray had important effects.

[Suture menisci with epidural transfixion pin to treating acute meniscus tear under arthroscope].

OBJECTIVE: To study the utility and effect of suturing menisci with epidural transfixion pin to treating acute meniscus tear under arthroscope. METHODS: Twenty-two cases with acute meniscus tear were selected, in which 18 were male and 4 were female,aged from 17 to 42 years with average of 28.5. The tearing menisci were sutured with epidural transfixion pin and unabsorbed suture. The follow-up were 6-12 months after operation. Meanwhile, Lysholm score, subjective symptoms and examination were recorded. RESULTS: Preoperative Lysholm scores were 46.72 +/- 13.46, whereas, postoperative ones were 89.43 +/- 18.21. There was significant difference between before and after operation (t = 1.85, P < 0.01). No recurrent interlocking, no pain in joint medialis and post-medialis space. McMurray test was negative. The complications about injury of blood vessel, nerves and tendons were not found during 6-12 months follow-up. CONCLUSION: The technique is advantageous in convenience, reliability, large suture strength and definite curative effect.

Study of upconversion fluorescence property of novel Er3+/Yb3+ co-doped tellurite glasses.

Er3+/Yb3+ co-doped TeO2-B2O3-Nb2O5-ZnO (TBN) glasses were prepared. The absorption spectra and upconversion luminescence spectra of TBN glasses were measured and analyzed. The upconversion emission bands centered at 530, 546 and 658 nm were observed under the excitation at 975 nm, corresponding to the transitions of 2H11/2-->4I15/2, 4S3/2-->4I15/2 and 4F9/2-->4I15/2 respectively. The ratio of red emission to green emission increases with an increasing of Yb3+ ions concentration. According to the quadratic dependence on excitation power, the possible upconversion mechanisms and processes were discussed.

Thermal stability, Judd-Ofelt theory analysis and spectroscopic properties of a new Er3+/Yb3+-codoped germano-tellurite glass.

The Er3+/Yb3+-codoped 70TeO2-5Li2O-10B2O3-15GeO2 glass was prepared. The thermal stability, absorption spectra, emission spectra and up-conversion spectra were measured and investigated. The Judd-Ofelt analysis based on absorption spectra was performed in order to determine the Judd-Ofelt intensity parameters Omega(t) (t = 2, 4, 6), spontaneous emission probability, radiative lifetime and branching ratios of several Er3+ transitions. It was found that this studied glass has good thermal stability, broad fluorescence full width at half maximum (FWHM), large stimulated emission cross-section and strong up-conversion emissions at about 532, 546 and 659 nm, corresponding to the 2H(11/2)-->4I(15/2), 4S(3/2)-->4I(15/2) and 4F(9/2)-->4I(15/2) transitions of Er3+, respectively under the excitation at 970 nm. The results suggest that this Er3+/Yb3+-codoped germano-tellurite glass may be a potentially useful material for developing potential amplifiers and up-conversion optical devices.

Investigation of thermal stability and spectroscopic properties in Er3+/Yb3+-codoped TeO2-Li2O-B2O3-GeO2 glasses.

The new Er3+/Yb3+ co-doped 70TeO2-5Li2O-(25-x)B2O3-xGeO2 (x = 0, 5, 10, 15 fand 20 mol.%) glasses were prepared. The thermal stability, absorption spectra, emission spectra and lifetime of the 4I(13/2) level of Er3+ ions were measured and studied. The FT-IR spectra were carried out in order to investigate the structure of local arrangements in glasses. It is found that the thermal stability, absorption cross-section of Yb3+, emission intensity and lifetime of the 4I(13/2) level of Er3+ increase with increasing GeO2 content in the glass composition, while the fluorescence width at half maximum (FWHM) at 1.5 um of Er3+ is about 70 nm. The obtained data suggest that this system glass can be used as a candidate host material for potential broadband optical amplifiers.

Study of luminescence properties of novel Er3+ single-doped and Er3+/Yb3+ co-doped tellurite glasses.

The novel Er(3+) single-doped and Er(3+)/Yb(3+) co-doped tellurite glasses were prepared. The effect of Yb(2)O(3) concentration on absorption spectra, emission spectra and upconversion spectra of glasses were measured and investigated. The emission intensity, fluorescence full width at half maximum (FWHM) and upconversion luminescence of Er(3+) go up with the increasing concentration of Yb(3+) ions. The maximum FWHM of (4)I(13/2) --> (4)I(15/2) transition of Er(3+) is approximate 77 nm for 1.41 x 10(21)ions/cm(3) concentration of Yb(3+)-doped glass. The visible upconversion emissions at about 532, 546 and 659 nm, corresponding to the (2)H(11/2) --> (4)I(15/2), (4)S(3/2) --> (4)I(15/2) and (4)F(9/2) --> (4)I(15/2) transitions of Er(3+), respectively, were simultaneously observed under the excitation at 970 nm. Subsequently, the possible upconversion mechanisms and important role of Yb(3+) on the green and red emissions were discussed and compared. The results demonstrate that this kind of tellurite glass may be a potentially useful material for developing potential amplifiers and upconversion optical devices.