[Minimally invasive lateral lumbar interbody fusion significantly improves the sagittal balance for adult degenerative scoliosis]

Objectives: To evaluate the effect of minimally invasive lateral lumbar interbody fusion (LLIF/OLIF) on the sagittal balance of adult degenerative scoliosis. Methods: From January 2014 to June 2017, a total of 23 patients with degenerative scoliosis underwent staged minimally invasive surgery in Shanghai Ruijin Hospital. All patients were implanted with LLIF or OLIF cage from the lateral approach first, and was followed by the posterior percutaneous pedicle screw fixation or pedicle screw fixation via Wiltse approach. If the sagittal deformity correction was not satisfactory after the first surgery, a posterior osteotomy can be performed during the second stage operation. A biplanar X-ray of the whole spine was taken with the EOS imaging system before and after surgery. The EOS software was used to measure and evaluate the patient's sagittal balance parameters including pelvic incidence (PI), pelvic tilt (PT), lumbar lordosis (LL), the sagittal vertical axis (SVA) and the coronal Cobb angle. The visual analogue scale (VAS) score for low back pain, the Oswestry Disability Index (ODI) score were evaluated before and after surgery. Paired t test or repeated measures ANOVA was used to compare the data before and after surgery. Results: There were 6 males and 17 females with a mean age of (72±4) years (62-79 years). Nine patients were treated with LLIF and 14 patients with OLIF. Sixteen cases were implanted with three cages, five with two cages and two with four cages. The mean follow-up period was 24.2 months (15-42 months). After the first operation, the Cobb angle of the patient was significantly improved (18°±7° vs 33°±8°, t=13.2, P<0.01). All the parameters for sagittal balance, including PI-LL (20°±8° vs 31°±8(o)), SVA ((5.3±2.0) cm vs (8.2±3.5) cm), PT (16°±6° vs 23°±4°) were all significantly improved as well (t=6.8, 4.5, 9.0, ALL P<0.01). At the last follow-up, the VAS score of low back pain (3.4±1.1 vs 6.3±1.0) and ODI scores (27.3%±3.0% vs 47.1%±5.9%) were also significantly improved (t=11.3, 17.8, both P<0.01). No major complications occurred in this group. Conclusions: Minimally invasive LLIF/OLIF can significantly improve the coronal and sagittal balance of adult degenerative scoliosis. Staged minimally invasive surgery can significantly alleviate pain and improve function in these patients.

Au nanorod-coupled microfiber optical humidity sensors

We demonstrate a high-sensitivity relative humidity (RH) sensor taking advantage of single-band narrow plasmon resonance of a single Au nanorod coupled to a whispering gallery cavity mode of a polyacrylamide microfiber. From the resonance peak shift, the sensor could achieve a sensitivity up to 0.51 nm/% RH with a cavity size of about 2 μm. By coupling multiple Au nanorods along the microfiber axis, we demonstrate a position-dependent microfiber optical humidity sensor with a 1.5-mm spatial resolution, which can be potentially reduced to micrometer level, paving a way toward high-resolution distributed microfiber optical sensors.

[Two-year clinical and radiological outcomes of minimally invasive surgery for severe adult degenerative scoliosis]

Objectives: To evaluate the efficacy of restoring the balance in the coronal and sagittal planes and to evaluate clinical outcomes in the treatment of severe adult degenerative scoliosis patients using staged lateral lumbar interbody fusion (LLIF) and percutaneous transpedicle screw fixation (pTSF). Methods: A retrospective analysis was made on 13 patients with severe adult degenerative scoliosis treated with staged surgery in Ruijin Hospital between May, 2014 and July, 2015. The operation data were collected, including operation time, estimated blood loss, and complications. Preoperative and postoperative standing anteroposterior and lateral lumbar radiographs were obtained by EOS image system in all patients for measurement of sagittal and coronal plane alignment. All patients were available for at least 24 months of following-up (18-32 months). Paired sample t test was used to compare the parameters of each group pre- and post-operation. Results: All of the 13 patients received LLIF with staged transpedicle screw fixation. Mean operation time was (231±48) minutes and (155±33) minutes for two-stage surgery. Mean blood loss was (253±80) ml during one-stage LLIF surgery and (326±99) ml during two-stage pTSF surgery. The interval between two surgical procedures was from 7 to 42 days (mean 14 days). In the coronal plane, the mean Cobb angle of curves was 43.1°±7.3° preoperatively, and it was 11.4°±4.0°after one-stage LLIF (t=10.16, P<0.001) and 5.5°±1.9° after two-stage pTSF (t=6.14, P<0.001). In the sagittal plane, lumbar lordosis (LL) changed after each procedure was as follows: LLIF from 16.8°±8.4° to 30.1°±6.8° (t=5.21, P<0.001) and PSF to 37.1°±4.0° (t=5.04, P<0.001). Sagittal vertical axis (SVA) was reduced from (10.5±2.4) cm to (5.3±2.1) cm after one-stage LLIF (t=8.52, P<0.001) and to (3.1±1.5) cm after two-stage pTSF (t=5.51, P<0.001). In the spino-pelvic parameter, pelvic incidence(PI)-LL mismatch decreased from 33.6°±9.6° to 17.8°±4.5° (t=5.31, P<0.001) after LLIF and to 9.9°±3.7° after pTSF (t=4.68, P<0.001). The visual analogue scale (VAS) of low back pain and leg pain and the Oswestry dability Index (ODI) improved significantly at the last follow-up (t=10.42, 8.94, 19.20, all P<0.01). Conclusions: LLIF significantly improves segmental and coronal plane alignment in patients with degenerative lumbar scoliosis, and these patients can be effectively corrected by staged minimally invasive surgery.

Phytotreatment of sewage sludge contaminated by heavy metals and PAHs by co-planting Sedum alfredii and Alocasia marorrhiza

High concentrations of heavy metals and organic pollutants in municipal sewage sludge are key factors limiting its use in agriculture. The objectives of this study were to decrease the heavy metal and polycyclic aromatic hydrocarbon concentrations in sewage sludge by phytotreatment and to determine, in a field experiment, whether co-planting is more effective than using a mono-crop of Sedum alfredii. Four treatments were used in the plot experiment: no sludge, no plants, S. alfredii and co-planting S. alfredii and Alocasia marorrhiza. The results showed that co-planting produced tubers and shoots of A. marorrhiza that were suitable as a safe animal feed and good organic K fertilizer, respectively. Co-planting was more effective than mono-planting at reducing concentrations of total Zn and diethylenetriaminepentaacetic acid (DTPA)-extractable Zn, Cd, and Cu in the sludge. Co-planting decreased the concentrations of DTPA-extractable heavy metals and benzo[a]pyrene (B[a]P) in the sludge significantly compared with the unplanted sludge. Decreases of 87, 75, 85, 31, and 64% were obtained for B[a]P and DTPA-extractable Zn, Cd, Cu, and Pb, respectively, compared with the fresh sludge. These results indicate that co-planting can reduce significantly the environmental risks associated with heavy metals and B[a]P in sewage sludge for further disposal.

Periodic nanoripples in the surface and subsurface layers in ZnO irradiated by femtosecond laser pulses

We present the formation of periodic ripples in ZnO crystal irradiated by a wavelength-tunable femtosecond laser. The results indicate that in the surface thin layer, the periods change from 0.1 lambda to lambda with laser fluences and pulse numbers, and in the subsurface layer the periods are always lambda/2n, where n is the refractive index. The formation processes and mechanisms are also discussed.

Enhanced 2.0 microm emission and gain coefficient of transparent glass ceramic containing BaF2: Ho3+,Tm3+ nanocrystals

Transparent glass ceramic containing BaF(2):Ho(3+),Tm(3+) nanocrystals has been prepared by melt quenching and subsequent thermal treatment. The precipitation of BaF(2) nanocrystals was confirmed by X-ray diffraction and high-resolution transmission electron microscopy. Intense 2.0 microm fluorescence originating from Ho(3+): (5)I(7) --> (5)I(8) transition was achieved upon excitation with 808 nm laser diode. A large ratio of forward Tm(3+) --> Ho(3+) energy transfer constant to that of backward process indicated high efficient energy transfer from Tm(3+)((3)F(4)) to Ho(3+)((5)I(7)), benefited from the reduced ionic distances of Tm(3+)-Tm(3+) and Tm(3+)-Ho(3+) pairs and low phonon energy environment with the incorporation of rare-earth ions into the precipitated BaF(2) nanocrystals. The results indicate that glass ceramic is a promising candidate material for 2.0 microm laser.

Complex periodic micro/nanostructures on 6H-SiC crystal induced by the interference of three femtosecond laser beams

We reported three types of complex micro/nanostructures on 6H-SiC crystal induced by the interferences of three femtosecond laser beams by arranging three types of laser polarization combinations. The micro/nanostructures are composed of two parts: two-dimensional long-periodic micropatterns determined by the interferential intensity pattern and short-periodic nanopatterns determined by the interferential polarization pattern. Theoretical calculation indicates that the different polarization combinations will lead to a distinct complex interferential polarization pattern and intensity pattern, and they accord well with the experimental results.