Ring-Rolling Process for Manufacturing Ti-6Al-4V Plane and Profiled Ring-Priducts

11scopu

Leakage of cement in percutaneous transpedicular vertebroplasty for painful osteoporotic compression fractures

OAIID:oai:osos.snu.ac.kr:snu2003-01/102/0000004226/8SEQ:8PERF_CD:SNU2003-01EVAL_ITEM_CD:102USER_ID:0000004226ADJUST_YN:NEMP_ID:A076317DEPT_CD:801CITE_RATE:1.503FILENAME:E005T_JBJS-B-2003_Yeom_Leakage of cement in percutaneous.pdfDEPT_NM:의학과EMAIL:[email protected]:YCONFIRM:

Strong interband interaction in the excitonic insulator phase of Ta2NiSe5

Excitonic insulator (EI) was proposed in the 1960s as a distinct insulating state originating from pure electronic interaction, but its material realization has been elusive with extremely few material candidates and with only limited evidence such as anomalies in transport properties, band dispersions, or optical transitions. We investigate the real-space electronic states of the low-temperature phase in Ta2NiSe5 with atomic resolution to clearly identify the quasiparticle energy gap together with the strong electron-hole band renormalization using scanning tunneling microscopy and spectroscopy (STS). These results are in good agreement with the EI transition scenario in Ta2NiSe5. Our spatially resolved STS data and theoretical calculations reveal further the orbital inversion at band edges, which indicates the exciton condensation close to the Bardeen-Cooper-Schrieffer regime. © 2019 American Physical Society.11Nscopu

Value of diagnostic lumbar selective nerve root block: a prospective controlled study

BACKGROUND AND PURPOSE: Although diagnostic lumbar selective nerve root blocks are often used to confirm the pain-generating nerve root level, the reported accuracy of these blocks has been variable and their usefulness is controversial. The purpose of this study was to evaluate the accuracy of diagnostic lumbar selective nerve root blocks to analyze potential causes of false results in a prospective, controlled, single-blinded manner. MATERIALS AND METHODS: A total of 105 block anesthetics were performed under fluoroscopic guidance in 47 consecutive patients with pure radiculopathy from a single confirmed level: 47 blocks were performed at the symptomatic level, and 58 were performed at the adjacent asymptomatic "control" level. Contrast and local anesthetics were injected, and spot radiographs were taken in all cases. We calculated the diagnostic value of the block anesthetics using concordance with the injected level. We analyzed the potential causes of false results using spot radiographs. RESULTS: On the basis of a definition of a positive block as 70% pain relief, determined by receiver-operator characteristic (ROC) analysis, diagnostic lumbar selective nerve root block anesthetics had a sensitivity of 57%, a specificity of 86%, an accuracy of 73%, a positive predictive value of 77%, and a negative predictive value of 71%. False-negatives were due to the following causes identifiable on spot radiographs: insufficient infiltration, insufficient passage of the injectate, and intraepineural injections. On the other hand, false-positives resulted from overflow of the injectate from the injected asymptomatic level into either the epidural space or symptomatic level. CONCLUSION: The accuracy of diagnostic lumbar selective nerve root blocks is only moderate. To improve the accuracy, great care should be taken to avoid inadequate blocks and overflow, and to precisely interpret spot radiographs

Value of diagnostic lumbar selective nerve root block: A prospective controlled study

BACKGROUND AND PURPOSE: Although diagnostic lumbar selective nerve root blocks are often used to confirm the pain-generating nerve root level, the reported accuracy of these blocks has been variable and their usefulness is controversial. The purpose of this study was to evaluate the accuracy of diagnostic lumbar selective nerve root blocks to analyze potential causes of false results in a prospective, controlled, single-blinded manner. MATERIALS AND METHODS: A total of 105 block anesthetics were performed under fluoroscopic guidance in 47 consecutive patients with pure radiculopathy from a single confirmed level: 47 blocks were performed at the symptomatic level, and 58 were performed at the adjacent asymptomatic control level. Contrast and local anesthetics were injected, and spot radiographs were taken in all cases. We calculated the diagnostic value of the block anesthetics using concordance with the injected level. We analyzed the potential causes of false results using spot radiographs. RESULTS: On the basis of a definition of a positive block as 70% pain relief, determined by receiver-operator characteristic (ROC) analysis, diagnostic lumbar selective nerve root block anesthetics had a sensitivity of 57%, a specificity of 86%, an accuracy of 73%, a positive predictive value of 77%, and a negative predictive value of 71%. False-negatives were due to the following causes identifiable on spot radiographs: insufficient infiltration, insufficient passage of the injectate, and intraepineural injections. On the other hand, false-positives resulted from overflow of the injectate from the injected asymptomatic level into either the epidural space or symptomatic level. CONCLUSION: The accuracy of diagnostic lumbar selective nerve root blocks is only moderate. To improve the accuracy, great care should be taken to avoid inadequate blocks and overflow, and to precisely interpret spot radiographs.OAIID:oai:osos.snu.ac.kr:snu2008-01/102/0000004226/3SEQ:3PERF_CD:SNU2008-01EVAL_ITEM_CD:102USER_ID:0000004226ADJUST_YN:YEMP_ID:A076317DEPT_CD:801CITE_RATE:2.745FILENAME:E014T_AJNR-2008_Yeom_Value of diagnostic lumbar selective.pdfDEPT_NM:의학과EMAIL:[email protected]:YCONFIRM:

Detecting photoelectrons from spontaneously formed excitons

Excitons, quasiparticles of electrons and holes bound by Coulombic attraction, are created transiently by light and play an important role in optoelectronics, photovoltaics and photosynthesis. They are also predicted to form spontaneously in a small-gap semiconductor or a semimetal, leading to a Bose?Einstein condensate at low temperature, but there has not been any direct evidence of this effect so far. Here we detect the photoemission signal from spontaneously formed excitons in a debated excitonic insulator candidate, Ta2NiSe5. Our symmetry-selective angle-resolved photoemission spectroscopy reveals a characteristic excitonic feature above the transition temperature, which provides detailed properties of excitons, such as the anisotropic Bohr radius. The present result provides evidence for so-called preformed excitons and guarantees the excitonic insulator nature of Ta2NiSe5 at low temperature. ? 2021, The Author(s), under exclusive licence to Springer Nature Limited.11Nsciescopu

Comparison of MR imaging findings between extraligamentous and subligamentous disk herniations in the lumbar spine.

BACKGROUND AND PURPOSE : The method of reating an HIVD in the lumbar spine may depend on the integrity of the PLL. The purpose of this study was to analyze and compare the MR imaging findings of extraligamentous and subligamentous HIVDs in the lumbar spine.MATERIAL AND METHODS: One hundred seventeen patients (M/F = 71:46; mean age, 47 years; age range, 15-79 years) underwent lumbar spine MR imaging and disk surgery (extraligamentous/subligamentous = 66:51) from May 2003 to November 2006. Two radiologists in consensus retrospectively reviewed all MR images, focusing on 10 criteria.RESULTS: The following 5 criteria are suggestive of extraligamentous HIVD in the lumbar spine: 1) spinal canal compromised for more than half its dimension, 2) internal signal difference in the HIVD, 3) an ill-defined margin of the HIVD, 4) disruption of the continuous low-signal-intensity line covering the HIVD, and 5) the presence of an internal dark line in the HIVD (P < .05). When we combined these 5 MR imaging criteria, the sensitivity, specificity, accuracy, and odds ratio were 77.3%, 74.5%, 76.1%, and 9.93 (P < .0001).CONCLUSIONS: Our proposed 5 MR imaging criteria will be helpful in differentiating extraligamentous and subligamentous HIVDs in the lumbar spine.OAIID:oai:osos.snu.ac.kr:snu2013-01/102/0000004226/1SEQ:1PERF_CD:SNU2013-01EVAL_ITEM_CD:102USER_ID:0000004226ADJUST_YN:NEMP_ID:A076317DEPT_CD:801CITE_RATE:2.928FILENAME:2013-AJNR_Oh_Comparison of MR imaging findings.pdfDEPT_NM:의학과EMAIL:[email protected]_YN:NCONFIRM:YCONFIRM:

Minimum 5-year follow-up results of skipped pedicle screw fixation for flexible idiopathic scoliosis: Clinical article

Object. The aim of this study was to evaluate after more than 5 years the outcome of surgical treatment for flexible idiopathic scoliosis using skipped pedicle screw fixation. Methods. For patients with spine curves 20%, pedicle screws had been inserted into every other segment on the corrective side and 2-4 screws per curve had been inserted on the supportive side. The authors analyzed the results in 57 patients, including the correction rate of coronal curvature and rotational deformity, correction loss, sagittal balance, complications, blood loss, operation time, and implant costs. Results. The mean Cobb angle was 54° preoperatively and 17° immediately after surgery (69% correction). At the last follow-up, the mean Cobb angle was 18° (2% correction loss). Rotation of the apical vertebra was corrected by 50% on average and showed only a 6% correction loss at the last follow-up. None of the patients had problems in maintaining sagittal balance. An adding-on phenomenon was detected in 4 patients (7%). Twelve of 14 patients with coronal decompensation showed improvement after surgery, whereas postoperative decompensation developed in 3 patients. Four patients had implant failures, and 4 had postoperative infections. The mean blood loss during surgery was 832 ml, and the mean operation time was 167 minutes. Compared with conventional methods, the authors'method used up to 48% fewer screws. Conclusions. Skipped pedicle screw fixation of flexible idiopathic scoliosis showed satisfactory results. This method has several advantages, including reduced blood loss, shorter operation time, and reduced cost.OAIID:oai:osos.snu.ac.kr:snu2011-01/102/0000004226/5SEQ:5PERF_CD:SNU2011-01EVAL_ITEM_CD:102USER_ID:0000004226ADJUST_YN:YEMP_ID:A076317DEPT_CD:801CITE_RATE:1.534FILENAME:E033T_JNS-Spine_Hwang_Minimum 5year followup results of skipped pedicle screw fixation.pdfDEPT_NM:의학과EMAIL:[email protected]_YN:NCONFIRM:YCONFIRM:

Raman spectroscopy as an indicator of Cu-S bond length in type 1 and type 2 copper cysteinate proteins

A series of metalloprotein mutants with novel copper cysteinate coordination environments has been probed by resonance Raman (RR) spectroscopy. These include H117G, M121E, and M121K mutants of Pseudomonas aeruginosa azurin and H46C, H80C, and H120C mutants of yeast CuZn-superoxide dismutase. In each case, excitation within a (Cys)S --> Cu charge transfer band leads to the enhancement of multiple vibrational modes of the copper cysteinate moiety. The predominant Cu-S stretching vibration, v(Cu-S), located in the 300-450 cm(-1) region, can be identified by (i) its large S- and Cu-isotope shifts, (ii) its high RR intensity, and (iii) its role as the generator of combination bands. The v(Cu-S) frequency appears to be a sensitive indicator of Cu-S(Cys) bond strength and, hence, copper coordination geometry. In the case of type 1 (T1) sites, the increased influence of the weak axial ligand upon moving from a trigonal planar (axial EPR) toward a more tetrahedral (rhombic EPR) geometry is associated with a decrease in v(Cu-S) from similar to 420 to similar to 350 cm(-1). In the case of type 2 (T2) sites with four strong ligands, v(Cu-S) undergoes further decreases from similar to 350 to similar to 310 cm(-1) as the geometry becomes more tetragonal. The Cu-S bond is successively weakened by trans ligand effects as the geometry approaches square planar. The decreased strength of the Cu-S(Cys) bond is further reflected in the increased strength of the adjacent S-C bond whose stretching frequency varies from similar to 750 cm(-1) for axial T1 sites to similar to 765 cm(-1) for T2 sites. The similar to 100-cm(-1) range in v(Cu-S) corresponds to a change in Cu-S(Cys) bond distance from similar to 2.13 Angstrom for an axial T1 site to similar to 2.29 Angstrom, for a tetragonal T2 site. The overlap of T1 and T2 v(Cu-S) frequencies near 350 cm(-1) shows that both types of Cu site can have similar Cu-S(Cys) bond strengths, despite their different EPR and optical characteristics, and points to a continuum of geometries linked through a tetrahedral structure which we describe as a T1.5 intermediate Cu site.Macromolecular Biochemistr