Comparison of clinical outcomes of expansive open-door laminoplasty with unilateral or bilateral fixation and fusion for treating cervical spondylotic myelopathy: a multi-center prospective study.

BACKGROUND: The present study evaluated the clinical outcomes and safety of expansive open-door laminoplasty, when securing with C4 - C6 lateral mass screw and fusion. METHODS: A total of 110 patients with cervical spondylotic myelopathy (CSM) were enrolled. There were 88 male and 22 female, with mean age at 60.55 ± 10.95 years. All of the patients underwent expansive open-door laminoplasty with unilateral or bilateral C4-6 lateral mass screws fixation and fusion. Clinical data, including age, gender, operation-related information, pre- and post-operation Japanese Orthopedic Association (JOA) scores, and cervical curvatures were collected. RESULTS: The mean follow-up time of the cohort was 13.61 ± 9.53 months. Among the 110 patients, 33 of them were allocated to Unilateral group, and 77 of them were in Bilateral group. The mean JOA score of the 110 patients before surgery was 10.07 ± 2.39, and the score was improved significantly to 12.85 ± 2.45 after surgery. There were no reported cases of neurological deterioration or symptom worsening. Patients in both the Unilateral group and Bilateral groups had significant improvement of JOA scores. Among all patients, the most frequently observed complications were axial symptoms (n = 7). The average preoperative cervical curvature among all patients was 15.17 ± 5.26, and the post-surgery curvature was 14.41 ± 4.29. Similar observations were found between Unilateral and Bilateral groups. CONCLUSION: The modified surgical approach provided satisfactory clinical outcome in patients with CSM. The unilateral and bilateral fixation appeared to provide similar outcomes, in terms of cervical curvature maintenance and improvement of clinical symptoms. However, the examination of the exact differences between the two fixation methods await further biomechanical studies.

A comparative theoretical study on the electrical and nonlinear optical properties of Li atom adsorbed on AlN and BN single-walled nanotubes.

The geometrical structures, electrical properties, and nonlinear optical (NLO) properties of AlNNT-Li and BNNT-Li nanotube systems were investigated by means of the density functional theory (DFT) method. Frontier molecular orbitals and density of states analyses show that adsorption of the Li atom can significantly narrow the wide HOMO-LUMO gaps of pure AlNNT and BNNT. The results reveal that AlNNT-Li and BNNT-Li systems containing diffuse excess electrons can be regarded as inorganic electrides. The formation of diffuse excess electrons leads to a decrease in transition energies, thereby increasing the first hyperpolarizabilities (ß 0) of AlNNT-Li and BNNT-Li. This work may contribute to the development of potential high-performance NLO materials. Graphical abstract The structural characteristics and nonlinear optical properties of the AlNNT-Li and BNNT-Li systems were studied by means of density functional theory. Introduction of Li atoms greatly enhances the static first hyperpolarizabilities of AlNNT-Li and BNNT-Li.

[Separation of Chlorophyll Fluorescence from Scattering Light of Algal Water Based on the Polarization Technique].

Once chlorophyll molecules within the planktonic algae cells absorb light energy, they will release energy in the form of chlorophyll fluorescence emission. The elastic scattering light of particles in water is partially polarized, while chlorophyll fluorescence is unpolarized, so we can use the properties to separate the fluorescence signal from total scattering spectra for further retrieval the concentration of chlorophyll. But for coastal waters, the approach feasibility is still unclear. Based on this, we conducted the experiment in laboratory to analyze the influence of different concentrations of inorganic particles (IOP) and chlorophyll on the fluorescence extraction using polarization discrimination technique. The results indicate that, for algae water with different concentrations of IOP, the fluorescence peak will decrease while the concentration increase, but the retrieval result is still reliable when the concentration up to 300 mg·L(-1). For algae water with different concentrations of chlorophyll, the concentration of chlorophyll more higher, the efficiency of extracted fluorescence using polarization method is better, for common water, this approach can still work. The study proves that the polarization method is also applicable for complex water; it is of great importance for further detecting the concentration of chlorophyll in coastal waters using remote sensing.

Five known tagging DLL3 SNPs are not associated with congenital scoliosis: A case-control association study in a Chinese Han population.

Genetic etiology hypothesis is widely accepted in the development of congenital scoliosis (CS). The delta-like 3 (DLL3) gene, a member of the Notch signaling pathway, was implicated to contribute to human CS. In this study, a case-control association study was conducted to determine the association of single nucleotide polymorphism (SNP) in the DLL3 gene with CS in a Chinese Han Population. Five known tagging SNPs of the DLL3 gene were genotyped among 270 Chinese Han subjects (128 nonsyndromic CS patients and 142 matched controls). CS patients were divided into 3 types: type I-failure of formation (29 cases), type II-failure of segmentation (50 cases), and type III-mixed defects (49 cases). The 5 SNPs were analyzed by the allelic and genotypic association analysis, genotype-phenotype association analysis, and haplotype analysis. Allele frequencies of 5 tagging SNPs (SNP1: rs1110627, SNP2: rs3212276, SNP3: rs2304223, SNP4: rs2304222, and SNP5: rs2304214) in CS cases and controls were comparable and there were no available inheritance models. The SNPs were not associated with clinical phenotypes. Moreover, the 5 makers in the DLL3 gene were found to be in strong linkage disequilibrium (LD). Both global haplotype and individual haplotype analyses showed that the haplotypes of SNP1/SNP2/SNP3/SNP4/SNP5 did not correlate with the disease (P >0.05). Together, these data suggest that genetic variants of the DLL3 gene are not associated with CS in the Chinese Han population.

Benefit of degenerative posterior longitudinal ligament removal during anterior decompression in cervical spondylotic myelopathy.

It remains controversial whether degenerative posterior longitudinal ligaments should be removed during anterior decompression procedures for cervical spondylotic myelopathy. Few data are available from studies that have compared removing and retaining the degenerative posterior longitudinal ligament. The goal of this retrospective study was to evaluate the benefit of degenerative posterior longitudinal ligament removal during such operations. Clinical data on 130 patients with confirmed degenerative posterior longitudinal ligament who underwent anterior cervical decompression surgery were retrospectively reviewed. All procedures were performed by the same senior orthopedic surgeon at the authors' spinal surgery center. The degenerative posterior longitudinal ligament was removed in 62 patients (group A) and retained in 68 patients (group B). The 130 patients were followed for 36 months. The Japanese Orthopedic Association score improved from 9.0±2.7 to 14.7±1.5 in group A and from 9.4±2.6 to 14.1±1.7 in group B (P=.028). The recovery rate for spinal cord neurologic function was 66.7% in group A and 61.3% in group B (P=.031). Operating time was longer (P=.002) and the sagittal median diameter of the vertebral canal was enhanced in group A (P<.001). Narrowing of previously enlarged canals occurred at a significantly higher rate in group B (P=.044). No significant difference was found in the rates of common complications between groups. Removal of the degenerative posterior longitudinal ligament in anterior decompression procedures for cervical spondylotic myelopathy appeared to be beneficial and provided more complete decompression and better postoperative outcomes than surgery without removal of the ligament. Although this procedure was generally safe, it required longer operating times, was more technically challenging, and required more experienced surgeons than surgery without removal of the ligament.

[Biomechanical effect on adjacent vertebra after percutaneous kyphoplasty with cement leakage into disc: a finite element analysis of thoracolumbar osteoporotic vertebral compression fracture].

OBJECTIVE: To explore the biomechanical effects on adjacent vertebra of thoracolumbar osteoporotic vertebral compression fracture (OVCF) after percutaneous kyphoplasty (PKP) with cement leakage into the disc by using finite element analysis. METHODS: T10-L2 segment data were obtained from computed tomography (CT) scans of an elder female with single T12 OVCF undergoing a cement leakage into the T12-L1 disc after PKP. A three-dimensional finite element Model of thoracolumbar spine (T10-L2) was built in the Mimics and the ABAQUS software. The stress on annulus fiber, nucleus pulposus, endplate and facet joints under axial pressure (0.3, 1.0, 4.0 MPa) were analyzed. RESULTS: The 3D finite element after percutaneous kyphoplasty (PKP) with cement leakage into the disc may be strongly related with the changes of biomechanical effects on adjacent vertebra of thoracolumbar OVCF. Models of thoracolumbar OVCF before and after PVP with a cement leakage into the T12-L1 disc were successfully established. The stresses increased with a rising axial pressure in the model of cement leakage into the disc after PVP, the stress augmentation scope on adjacent end plates(T11 low plate & L1 top plate) and intervertebral disc (T11-12 & T12-L1) increased. The maximal Von Mises stress on adjacent vertebra (T11 & L1) increased while but the maximal Von Mises stress on end vertebra (T10 & L2) decreased. CONCLUSION: Postoperative adjacent vertebral fracture.

[Three-dimensional finite element model of thoracolumbar spine with osteoporotic vertebral compression fracture].

OBJECTIVE: To build a three-dimensional finite element model of thoracolumbar spine with osteoporotic vertebral compression fracture (OVCF) and analyze its biomechanical change. METHODS: The T10-L2 segment data were obtained from computed tomography (CT) scans of an elderly female with a single T12 OVCF. A three-dimensional finite element model of thoracolumbar spine was constructed with the MIMICS and ABAQUS software. The model was composed of bony vertebrae, articulating facets, intervertebral disc and associated ligaments. The basic stress analysis of T10-L2 motion segment was made for different material properties of bone, ligaments and facet joints contacting frictional property. The stress on the annulus fiber, nucleus pulposus, endplate and facet joints under axial pressure (0.3 MPa, 1.0 MPa, 4.0 MPa) were analyzed. RESULTS: A three-dimensional finite element model of human T12-L2 motion segment had 617468 elements. And the stress was higher in vertebral body than posterior structure. The distribution of pressure stresses in intervertebral disc was asymmetrical. The stress increased with a rising axial pressure. CONCLUSION: 3D finite element model of thoracolumbar OVCF and adjacent segments are successfully established. The results of stress analysis are both feasible and reliable.

The nitrogen edge-doped effect on the static first hyperpolarizability of the supershort single-walled carbon nanotube.

The nitrogen edge-doped effect on the structure, dipole moment, and first hyperpolarizability of the supershort single-walled carbon nanotube (5, 0) has been studied systematically. For the nitrogen edge-doped effect on the structure, the mean diameter on the nitrogen-doped side (D(u)) decreases as the number of doped-nitrogen (n) increases (4.044 (1) > 3.991 (2) > 3.941 (3) > 3.891 (4) > 3.844 A (5)). Significantly, the nitrogen edge-doped effects on the dipole moment and first hyperpolarizability are revealed for the first time and these new effects are dramatic for the supershort single-walled carbon nanotube (5, 0). Among the beta(0) values of these seven nitrogen-doped structures, the largest beta(0) (3155 au) is larger by almost 450 times than the very small beta(0) (7 au) of undoped structure (D(5h)). For nitrogen-doped structures, the order of the beta(0) values is 3155 (1) > 2677 (2A) approximately 2817 (2B) > 1465 (3A) approximately 1458 (3B) > 670 (4) > 254 au (5), which shows two interesting relationships between the beta(0) value and nitrogen-doped number: (1) the smaller the nitrogen-doped number, the larger the beta(0) value. (2) The structures with the same number of doped-nitrogen have almost the same beta(0) values (1465 for 3A and 1458 au for 3B). As for the frequency-dependent beta (-omega; omega, 0) and beta (-2omega; omega, omega), the dependence on the nitrogen-doped number (n) is similar to the case of static beta(0). For beta (-2omega; omega, omega) values at omega = 0.005 au are 3220 (1) > 2720 (2A) approximately = 2862 (2B) > 1480 (3A) approximately = 1477 (3B) > 676 (4) > 256 au (5). In addition, the important monotonic dependences of the beta value on the D(u) and electronic spatial extent are also observed. The new knowledge of influence the beta value will be beneficial to design high-performance nonlinear optical (NLO) materials.

[Influence of Wnt-1 recombinant adenovirus on differentiation of human epidermal stem cells].

OBJECTIVE: To observe the influence of Wnt-1 recombinant adenovirus on differentiation tendency of human epidermal stem cells. METHODS: Wnt-1 recombinant adenovirus was transduced into hESCs (E group), while normal hESCs were used as control (C) group. The diameter, proliferation,and labeling molecular expression of hESC were determined. The content of MMP-2 and MMP-7 in supernate were also assayed. RESULTS: There was no obvious difference in diameter of hESC between two groups. The density of hESC in E group was (1.45 +/- 0.09) x 10(5)/mL, which was obviously higher than that in C group [(1.18 +/- 0.10) x 10(5)/mL, P < 0.05]. There were no obvious differences in expression of markers between two groups,including keratin 5 (KS), K6, K7, KS, K14, CD44, carcinoembryonic-like antigen (CEAA), ER, PR (P > 0.05) ,while the expression of K 10 was different among groups [(60 +/- 3)% in E group, 0 in C group], also K18 [(34.3 +/- 2.1)% in E group vs. (13.8 +/- 1.7)% in C group, P < 0.05], and K19 [(17.1 +/- 1.8)% in E group vs. (24.4 +/- 1.5)% in C group, P < 0.05].The contents of MMP-2 and MMP-7 in E group were higher than those in C group (P < 0.01). CONCLUSION: Wnt-1 recombinant adenovirus can induce the differentiation of hESCs to glandular epithelium-like cells.

Structures and considerable static first hyperpolarizabilities: new organic alkalides (M+@n6adz)M'- (M, M'=Li, Na, K; n=2, 3) with cation inside and anion outside of the cage complexants.

Eighteen structures of new organic alkalides (M+@n6adz)M'- (M, M'=Li, Na, K; n=2, 3) with the alkali-metal cation M+ lying near the center of the adz cage and the alkali-metal anion M'- located outside are obtained with all real frequencies. They exhibit very large static first hyperpolarizabilities (beta0) up to 3.2x10(5) au, which exceeds the record value of beta0=1.7x10(5) au for nonlinear optical compounds [Chem.-Eur. J. 1997, 3, 1091]. All potassides (M+@n6adz)K- (M=Li, Na, K; n=2, 3) have considerably large beta0 values (1.6x10(5)-3.2x10(5) au) much larger than the beta0 value (3.6x10(4) au) of the previously designed cuplike alkalide Li+(calix[4]pyrrole)K- [J. Am. Chem. Soc. 2006, 128, 1072]. This shows that the 26adz and 36adz cage complexants are preferable to cuplike calix[4]pyrrole complexant in enhancing the first hyperpolarizability. The effect of cage size of the complexant on the first hyperpolarizability is also presented here: in most cases, the smaller cage complexant corresponds to the larger beta0 value. Moreover, the crucial role by the alkali-metal anion in the large first hyperpolarizability of these alkalides is revealed. These results may provide new means for designing high-performance nonlinear optical materials.

Structures and static electric properties of novel alkalide anions F-Li+Li- and F-Li3+Li3-.

Novel cluster anions Li2F- and Li6F- with alkalide character have been studied in the present paper. In contrast to a typical neutral alkalide, Li2F- contains a F- anion instead of the neutral ligand and forms an alkalide anion F-Li+Li-. In addition to a F- anion ligand, Li6F- contains a Li3+ superalkali cation instead of the alkali metal cation and a Li3- superalkali anion instead of the alkali metal anion, and this alkalide anion can be denoted by F-Li3+Li3-, which is supported by NBO charge results. The results indicate that the F- anion can polarize not only the Li atom but also the Li3 superalkali to form alkalide anions with excess electrons. For Li2F-, two linear structures (1Sigma+ and 3Sigma+ states) are obtained. For Li6F-, the structure of the 1A1 state is a trigonal antiprism capped by the F- anion with C3v symmetry, while the structure of the 7A' state is a slightly distorted trigonal antiprism with Cs symmetry. Due to the excess electrons on the alkali metal and superalkali anions (Li- and Li3-), the alkalide anions Li2F- and Li6F- have large first hyperpolarizabilities (beta0=1.116x10(4)-1.764x10(5) au). For the spin multiplicity effect on electric properties, in these two alkalide anions, the values of the static electric properties, especially the first hyperpolarizabilities, of the high spin states are larger than the corresponding values of the low spin states. For the substitution effect of superalkali atoms, in the two singlet states, as the Li3 superalkalis substitute the Li atoms, the value of the mean of polarizability increases, while the values of dipole moment and the first hyperpolarizability decrease.

Structures and large NLO responses of new electrides: Li-doped fluorocarbon chain.

An alkali-metal-doped effect on the nonlinear optical (NLO) property in new electrides is studied. The electrides are formed by doping alkali atom Li into a fluorocarbon chain H-(CF2-CH2)3-H. Six stable structures of the Lin-H-(CF2-CH2)3-H (n = 1, 2) complexes with all real frequencies are obtained at the MP2/6-31+G (d) level. Among these six structures, the largest first static hyperpolarizabilities (beta(0)) are found to be 76,978 au, which is much larger than the beta(0) value of 112 au for H-(CF2-CH2)3-H. Clearly, the Li-atom-doped effect on the first hyperpolarizability is dramatic. Three interesting relationships between the structure and beta(0) value have been observed. (1) For the one-Li-atom-doped systems as well as for the structures with two opposite Li atoms, the shorter the distance between the Li atom and difluoromethyl group, the larger the beta(0) value. (2) The beta(0) values of the two-Li-atom-doped chains are much larger than those of the one-Li-atom-doped systems, except for the case of cis-AB where the Li-Li distance (2.847 Angstrom) is close to the bond length of the Li2 molecule (2.672 Angstrom). (3) For the two-Li-atom-doped chains, the beta(0) value increases as the Li-Li distance increases. These relationships between the structure and beta(0) value may be beneficial to experimentalists for designing electrides with large NLO responses by using the alkali-metal-doped effect.

Effect of the complexant shape on the large first hyperpolarizability of alkalides Li+(NH3)4M-.

The effect of complexant shape effect on the first hyperpolarizability beta(0) of alkalides Li(+)(NH(3))(4)M(-) (M=Li, Na, K) was explored. At the MP2/6-311++G level, Li(+)(NH(3))(4)M(-) (M=Li, Na, K) have considerable beta(0) values due to excess electrons from chemical doping and charge transfer. By comparison with the alkalides Li(+)(calix[4]pyrrole)M(-), a complexant shape effect in Li(+)(NH(3))(4)M(-) is detected. The beta(0) values of Li(+)(NH(3))(4)M(-) with the "smaller", inorganic, T(d)-symmetric (NH(3))(4) complexant are more than four times larger than those of Li(+)(calix[4]pyrrole)M(-) with the "larger", organic C(4v)-symmetric calix[4]pyrrole complexant. The ratios of the beta(0) values of Li(+)(NH(3))(4)M(-) and Li(+)(calix[4]pyrrole)M(-) are 6.57 (M=Li ), 6.55 (M=Na), and 5.17 (M=K). In the Li(+)(NH(3))(4)M(-) systems, the NBO charge and oscillator strength are found to monotonically depend on the atomic number of the alkali metal anion. The order of the NBO charges of the alkali anions M(-) is -0.667 (M=Li )>-0.644 (M=Na)>-0.514 (M=K), while the order of the oscillator strengths in the crucial transition is 0.351 (M=Li )<0.360 (M=Na)<0.467 (M=K). This indicates that complexant shape effects are strong, and consequently the beta(0) values of Li(+)(NH(3))(4)M(-) are found to be beta(0)=70 295 (M=Li )<96 780 (M=Na)<185 805 a.u. (M=K). This work reveals that the use of a high-symmetry complexant is an important factor that should be taken into account when enhancing the first hyperpolarizability of alkalides by chemical doping.

What is the role of the complexant in the large first hyperpolarizability of sodide systems Li(NH3)(n)Na (n = 1-4)?

To explore the coordination number (around the cation) dependence of the nonlinear optical (NLO) properties in alkalides, this paper studies the structures and large NLO responses of model alkalides, Li(NH3)(n)Na (n = 1-4). At the MP2/aug-cc-pVDZ level, the structural characteristic is determined to be that the Li-Na distance increases (from 3.030 to 4.646 angstroms) with the increasing of the number of NH3 (n from 1 to 4). Results show that Li(NH3)(n)Na (n = 1-4) have considerably large first hyperpolarizabilities (beta0). Especially, a prominent coordination number dependence of the beta0 value is found as follows: beta0 = 13 669 (n = 1) < 26,840 (n = 2) < 39 764 (n = 3) < 77 921 au (n = 4) at the MP2 level. With the same coordination number (four N atoms) of Li+ cations, the beta0 value (77,921 au) of this "small" inorganic molecule Li(NH3)(n)Na is over five times larger than that of the "big" organic molecule Li@Calix[4]pyrrole-Na (14,772 au). This indicates that the beta0 value is strongly related to the flexibility of the complexant. Obviously, the flexibility of (NH3)4 is much greater than that of the cup-like shaped Calix[4]pyrrole. This work suggests that two important factors should be taken into account to enhance the first hyperpolarizability of alkalide, i.e., the coordination number around the cation and the flexibility of the complexant.

Characteristics of antiaromatic ring pi multi-hydrogen bonds in (H2O)n-C4H4 (n = 1, 2) complexes.

By counterpoise-corrected optimization method, the six antiaromatic ring pi multi-hydrogen bond structures with diversiform shapes for (H2O)n-C4H4 (n = 1,2) have been obtained at the MP2/aug-cc-pVDZ level. At the CCSD(T)/aug-cc-pVDZ level, the interaction energy obtained mainly depends on the numbers of H2O and fold numbers of the pi multi-hydrogen bond. The interaction energy order is -2.342 (1a with pi mono-hydrogen) < -2.777 (1b with pi bi-hydrogen) << -4.683 (2a with pi bi-hydrogen) < -4.734 (2b with pi tri-hydrogen) < -4.782 (2c with pi tri-hydrogen) < -5.009 kcal/mol (2d with pi tetra-hydrogen bond). Strangely, why is the interaction energy of the pi bi-hydrogen bond in 1b close to that of the pi mono-hydrogen bond in 1a (their difference is only 15.7%)? The reason is that a pi-type H-bond (as an accompanying interaction) between two lone pairs of the O-atom and a near pair of H-atoms of C4H4 exists shoulder by shoulder in structures 1a, 2a, 2b, and 2c and contributes to the interaction energy. Another accompanying interaction, a repulsive interaction between the pi H-bond (using the H-atom(s) of H2O) and the near pair of H-atoms of C4H4, is also found. For the structures and interaction energies, the pi-type H-bond produces four effects: bending the strong pi H-bond, attracting the pair of H-atoms of C4H4 so that they deviate from the C4 ring plane, showing the interaction energy contribution, and bringing the larger electron correlation contribution. The repulsive interaction also produces four effects: pushing the pair of H-atoms of C4H4 so that they deviate from its ring plane, elongating the distance of the pi H-bond, promoting the formation of pi-type H-bond, and slightly influencing the interaction energy. In the present paper, one C=C bond with two H2O (over and below the ring plane) forms a pi H-bond link in two ways: a strong-weak pi H-bond link and a strong-strong pi H-bond link. The stability contribution of the former is more favorable than the latter. One H2O forms a pi H-bond with C4H4 in two ways. One strong pi H-bond part (over or below the ring plane) always is accompanied by another H-bond part. The accompanying part is either a weak pi H-bond or pi-type H-bond.

Proton transfer of NH3-HCl catalyzed by only one molecule.

The proton transfer in NH(3)-HCl by only one molecule of catalyst was studied by using the MP2 method with the large 6-311++G(2d,2p) basis set. The 18 structures are obtained for the smallest units, NH(3)-HCl-A trimers, for which the proton transfer maybe occurred. The final results show that the proton transfers have occurred in the 15 cyclic shape structures for A = H(2)SO(4), H(2)SO(3), HCOOH (a), HF, H(2)O(2), HNO(3), HNO(2) (a), CH(3)OH, HCl, HNC, H(2)O, HNO(2) (b), NH(3), HCOOH (b), and HCHO, and not occurred in another 3 trimer structures for A = HCN, H(2)S, and PH(3). These results show that the proton transfer occurs from HCl to NH(3) when catalyst molecule A (acidic, neutral, or basic) not only as a proton donor strongly donates the proton to the Cl atom but as an acceptor strongly accepts the proton from the NH(3) molecule in the cyclic H-bond structure. In this work, a proton circumfluence model is proposed to explain the mechanism of the proton transfer. We find that, for the trimer, when the sum of two hydrogen bond lengths (R = R(1) + R(2)) is shorter than 5.0 A, molecule A has the ability to catalyze the proton transfer. In addition, we also find that the interaction energy E(int) between NH(3)-HCl and A is nearly related to the extent (R(H1)(-)(Cl)) of proton transfer, that is, the interaction energy E(int) increases with the proton transfer.

[The study of treatment of osteoporotic thoracolumbar multi-vertebral compressive fractures by kyphoplasty with one balloon].

OBJECTIVE: To evaluate the effect of kyphoplasty in treating osteoporotic thoracolumbar multi-vertebral compressive fractures with one balloon. METHODS: thirteen cases (37 vertebral bodies) of osteoporotic thoracolumbar multi-vertebral compressive fractures were treated. The patients were women, range 65 to 79 years old, and all with well intact posterior wall of vertebral body. 37 thoracolumbar vertebral bodies were treated by Kyphoplasty with one balloon under "C" armed imaging guiding. RESULTS: All 13 patients tolerated well. The mean height of the anterior, media and posterior vertebral bodies was (1.9 +/- 0.5) cm, (1.5 +/- 0.5) cm, (2.6 +/- 0.5) cm preoperatively and (2.1 +/- 0.4) cm, (2.2 +/- 0.4) cm, (2.8 +/- 0.5) cm postoperatively (P < 0.001). The mean kyphosis was improved from (31.3 +/- 14.1) degrees to (24.8 +/- 11.3) degrees. There was not back pain and deformed correction was maintained well after 17.3 months' follow up, No complication occurred. CONCLUSION: The balloon was not damaged, because the pressure was lower than usual pressure, the cost of patients was saved. In this study, we fulfilled small amount of cement in vertebral body which reduced the leakage of cement. Fracture of close vertebral body was also reduced because of lower stiffness and modulus of elasticity of adjacent vertebral body.

The static polarizability and first hyperpolarizability of the water trimer anion: ab initio study.

This work predicts the extraordinary hyperpolarizability of inorganic clusters: two water trimer anions. The first hyperpolarizabilities of (H2O-)(3) are considerable, beta(0)=1.715 x 10(7) a.u. for configuration A and beta(0)=1.129 x 10(7) a.u. for configuration B at MP2/d-aug-cc-pVDZ+x level. The first hyperpolarizabilities of (H2O-)(3) (configuration A) and related systems [(H2O)(3) and (H2O)(3)F-] are compared at the MP2/d-aug-cc-pVDZ+x level. These results are beta(0)=1.715 x 10(7) a.u. for (H2O-)(3), beta(0)=35 a.u. for (H2O)(3) [the neutral core of (H2O-)(3)], and beta(0)=46 a.u. for (H2O)(3)F-). Comparing the beta(0) values of related systems, we find that the dipole-bound excess electron is the key factor in the extraordinary first hyperpolarizability of (H2O-)(3) species. It will provide a future in the development of some materials with the excess electron (e.g., electrides) that exhibit large nonlinear optical response.