[Clinical study of intercondylar fossa formation to prevent intercondylar fossa impingement after high tibia osteotomy].

OBJECTIVE: To observe the clinical efficacy of intercondylar fossa plasty in preventing intercondylar fossa impingement syndrome after high tibial osteotomy. METHODS: From August 2018 to August 2020, 84 patients with inverted knee osteoarthritis were treated by arthroscopy combined with high tibial osteotomy, and were divided into two groups with 42 cases in each group according to different surgical methods. In the intercondylar fossa plasty group, there were 13 males and 29 females, age ranged from 52 to 67 years old with an average of(58.27±4.32) years old, and arthroscopic intercondylar fossa plasty was performed first, and then high tibial osteotomy. In the arthroscopic cleansing group, 16 males and 26 females, age ranged from 50 to 71 years old with an average of (59.02±5.14) years old, underwent arthroscopic cleansing and then high tibial osteotomy. Postoperative treatment was evaluated using visual analogue scale(VAS), hospital for special surgery (HSS) score for the knee, and the occurrence of intercondylar percussa impingement. RESULTS: All 84 patients were followed up, the duration ranged from 12 to 18 months with an average of (14.1±1.6) months. The VAS and HSS score of knee joint at 6, 12 and 18 months after surgery were significantly improved compared with preoperative period, and there was no significant difference between the two groups (P>0.05), but the incidence of intercondylar fossa index and intercondylar fossa impact between the two groups was significantly compared 18 months after surgery (P<0.05). CONCLUSION: Intercondylar fossa plasty can effectively prevent the incidence of intercondylar fossa impact after high tibial osteotomy, and has a more significant effect on postoperative knee pain and function improvement.

Tunable orientation of two-dimensional assembled Au octahedron superlattices in polymer films as flexible SERS substrates.

Anisotropic nanoparticles have been widely used as building blocks for preparing surface-enhanced Raman spectroscopy (SERS) substrates. However, tailoring the SERS activity at the self-assembly level through the anisotropic nanoparticle orientation is a big challenge, mainly due to the lack of simple assembly methods. In the present work, we report an air-water interface mediated co-assembly (AWIMCoA) strategy to prepare flexible 2D superlattices of Au octahedra with tunable orientations. We have demonstrated that Au octahedra can self-assemble into face-up, edge-up and vertex-up orientations on changing the surface wettability of Au octahedra, which determines the interparticle anisotropic interactions and the interaction between Au octahedra and the poly(styrene-ethylene-butylene-styrene) (SEBS) nanomembrane. The effect of assembly orientation on the SERS performance of 2D superlattices has been studied through correlated SEM characterization and SERS mapping. Among all the orientational modes, flexible 2D superlattices with the vertex-up orientation show the highest enhancement performance and uniformity, which is further demonstrated by theoretical simulation. Partially embedded 2D superlattices in the SEBS nanomembrane are robust to remove the surface ligands without breaking the whole nanostructure. This post-treatment process boosts the SERS performance of the 2D superlattice with the edge-up orientation by forming fused nanostructures among neighboring Au octahedra. We expect that the co-assembly method will be widely applied in the preparation of reusable and high-performance SERS substrates for broad application.

Advanced plasmonic technologies for multi-scale biomedical imaging.

The use of imaging technologies has been critical in deciphering biological phenomena, structures, and mechanisms across a wide range of spatial scales. The spatial resolution of traditional imaging modalities cannot meet the needs of high-precision research and diagnosis in biomedical fields. Plasmon resonance is the light-matter interaction that allows localizing far-field radiation in the near field with an intense electromagnetic field, enhancing the nanometric ablation, elastic/inelastic scattering of the adsorbate, and photoluminescence of the fluorophore nearby. Further, plasmon resonance scattering of nanoparticles can sensitively indicate the local environmental changes. This is accomplished by combining the spatially resolved capability with molecular spectrometry techniques such as Raman, infrared, fluorescence, etc., leading to a series of excellent imaging techniques to interrogate diverse biological processes from the tissue to subcellular level. In this tutorial review, we first provide the fundamental aspects of plasmonics. Then we give a systematic discussion of the working principle of these plasmon-based imaging techniques with an emphasis on the achievable spatial resolutions: surface-enhanced Raman spectroscopy (micrometre to nanometre), tip-enhanced ablation and ionization mass spectrometry (submicrometre), scattering-type scanning near-field optical microscopy (nanometre), tip-enhanced Raman spectroscopy (nanometre), tip-enhanced fluorescence spectroscopy (nanometre), and plasmon/molecular ruler microscopy (nanometre to angstrom). We also review the recent developments of the bioimaging applications of these techniques and expect that the plasmon-based techniques will not only pave a new way to decipher mysteries in life sciences but also hold great potential to be extended from fundamental research studies to real-life biomedical applications.

Treatment of primary tracheal schwannoma with endoscopic resection: A case report.

BACKGROUND: Schwannoma is a benign tumor originating from the peripheral nerve sheath. The clinical symptoms of tracheal schwannoma depend on the location of the tumor, and the most common clinical symptoms are cough and hemoptysis. The most effective treatment for benign tumors is complete resection of the primary lesion at an early stage. Our experience has demonstrated that primary tracheal schwannoma can be safely excised with a high-frequency electric knife in a minimally invasive manner. CASE SUMMARY: We report a 61-year-old asymptomatic woman who underwent chest computed tomography (CT), which accidentally found an intraluminal tracheal mass without enlarged lymph nodes. Then, the patient underwent bronchoscopy, which found that the tracheal mass originated from the left wall of the upper trachea, was less than 1.5 cm in size, immovable, smooth and 4 cm away from the vocal cord, resulting in partial upper respiratory tract obstruction. Treatment was performed using an endoscopic resection for en bloc removal of the tracheal mass. The diagnosis was primary tracheal schwannoma. A follow-up was performed after endoscopic surgery, and bronchoscopy and thoracic CT were used to monitor whether there was a recurrence. At present, there is no evidence of recurrence, and the patient had a good quality of life. Endoscopic resection may be effective and safe in the treatment of primary tracheal schwannoma. CONCLUSION: Primary tracheal schwannoma is a very rare benign tumor. In this case, we cured it by complete endoscopic resection.

Self-Calibration 3D Hybrid SERS Substrate and Its Application in Quantitative Analysis.

Surface-enhanced Raman spectroscopy (SERS) has been widely applied in many fields as a sensitive vibrational fingerprint technique. However, SERS faces challenges in quantitative analysis due to the heterogeneity of hot spots. An internal standard (IS) strategy has been employed for correcting the variation of hot spots. However, the method suffers from limitations due to the competitive adsorption between the IS and the target analyte. In this work, we combined the IS strategy with the 3D hybrid nanostructures to develop a bifunctional SERS substrate. The substrate had two functional units. The bottom self-assembly layer consisted of Au@IS@SiO2 nanoparticles, which provided a stable reference signal and functioned as the calibration unit. The top one consisted of appropriate-sized Au octahedrons for the detection of target analytes, which was the detection unit. Within the 3D hybrid nanostructure, the calibration unit improved the SERS performance of the detection unit, which was demonstrated by the 6-fold increase of SERS intensity when compared with the 2D substrate. Meanwhile, the reproducibility of the detection was greatly improved by correcting the hot spot changes through the calibration unit. Two biomedical molecules of cotinine and creatinine in ultrapure water and artificial urine, respectively, were sensitively determined by the 3D hybrid substrate. We expect that the developed bifunctional 3D substrate will open up new ways to advance the applications of SERS.

[High tibial osteotomy combined with lateral retinacular release for the treatment of knee varus osteoarthritis with lateral patellar compression syndrome].

OBJECTIVE: To investigate the clinical effect of high tibial osteotomy combined with arthroscopic lateral retinacular release in the treatment of knee varus osteoarthritis. METHODS: From October 2017 to April 2019, a retrospective analysis was performed on 43 patients with knee varus osteoarthritis and lateral patellar compression syndrome treated by high tibial osteotomy combined with arthroscopic lateral retinacular release. There were 15 males and 28 females, aged 53 to 72(62.05±5.17) years. The visual analogue scale(VAS), Lysholm, and the knee range of motion were used to evaluate knee pain and functional recovery before operation, 2 weeks, 3 months and 12 months after operation. And the congruence angle (CA), patellar tilt angle (PTA), and femala-tibial angle (FTA) were measured respectively before and 12 months after operation to evaluate the congruence of patellar joint, and the improvement of line of gravity of lower limb. RESULTS: All 43 patients were followed up for more than 12 months, with a follow-up time of 14 to 28 (19.60±4.50) months. The VAS scores decreased from 6.65±0.65 before operation to 2.16±0.95, 0.51±0.77 and 0.33±0.64 at 2 weeks, 3 months and 12 months after operation, and the difference was statistically significant (P<0.001). Lysholm score increased from 43.02±8.54 before operation to 46.84±2.81, 72.42±5.30, and 93.40±5.44 at 2 weeks, 3 months and 12 months after operation, and the difference was statistically significant (P<0.001). The knee range of motion increased from (86.97±5.02)° before operation to (99.38±3.27)°, (110.13±4.13)°, and (113.03±4.85)° at 2 weeks, 3 months and 12 months after operation, the difference was statistically significant (P<0.001). The CA decreased from (7.81±1.21)° before operation to (5.82±4.10)° at 12 months after operation, the PTA decreased from (15.87±2.89)° before operation to (13.79±4.26)° at 12 months after operation, and the FTA decreased from(182.61±2.07)° before operation to(170.89±0.89)° at 12 months after operation, and the differences were statistically significant (P<0.05). One case received proper braking and anticoagulation after operation, and was improved after 1 week. The swelling was observed in 14 patients after operation, and subsided about 2 weeks later. CONCLUSION: High tibial osteotomy combined with arthroscopic lateral retinacular release can relieve weight-bearing pain in frontal axis and improve the function of knee in sagittal axis.

Accuracy of endoscopic ultrasound-guided needle aspiration specimens for molecular diagnosis of non-small-cell lung carcinoma.

BACKGROUND: Endoscopic ultrasonography-guided fine-needle aspiration (EUS-FNA) and endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) are highly sensitive for diagnosing and staging lung cancer. In recent years, targeted therapy has shown great significance in the treatment of non-small cell lung carcinoma (NSCLC). Using these minimally invasive techniques to obtain specimens for molecular testing will provide patients with a more convenient diagnostic approach. AIM: To evaluate the feasibility and accuracy of tissue samples obtained using EUS-FNA and EBUS-TBNA for molecular diagnosis of NSCLC. METHODS: A total of 83 patients with NSCLC underwent molecular testing using tissues obtained from EUS-FNA or EBUS-TBNA at the Tianjin Medical University Cancer Hospital from January 2017 to June 2019. All enrolled patients underwent chest computed tomography or positron emission tomography/computed tomography prior to puncture. We detected abnormal expression of EGFR, KRAS, MET, HER2, ROS1 and anaplastic lymphoma kinase protein. Two patients failed to complete molecular testing due to insufficient tumor tissue. The clinical features, puncture records, molecular testing results and targeted treatment in the remaining 81 patients were summarized. RESULTS: In a total of 99 tissue samples obtained from 83 patients, molecular testing was successfully completed in 93 samples with a sample adequacy ratio of 93.9% (93/99). Biopsy samples from two patients failed to provide test results due to insufficient tumor tissue. In the remaining 81 patients, 62 cases (76.5%) were found to have adenocarcinoma, 11 cases (13.6%) had squamous cell carcinoma, 3 cases (3.7%) had adenosquamous carcinoma and 5 cases (6.2%) had NSCLC-not otherwise specified. The results of molecular testing showed EGFR mutations in 21 cases (25.9%), KRAS mutations in 9 cases (11.1%), ROS-1 rearrangement in 1 case (1.2%) and anaplastic lymphoma kinase-positive in 5 cases (6.2%). Twenty-four patients with positive results received targeted therapy. The total effectiveness rate of targeted therapy was 66.7% (16/24), and the disease control rate was 83.3% (20/24). CONCLUSION: Tissue samples obtained by EUS-FNA or EBUS-TBNA are feasible for the molecular diagnosis of NSCLC and can provide reliable evidence for clinical diagnosis and treatment.

[Evaluation of cartilage regeneration by arthroscopy after high tibial osteotomy].

OBJECTIVE: To evaluate the cartilage regeneration in the knee joint by arthroscopy after high tibial osteotomy. METHODS: Eleven patients were included in the study who were treated with high tibial osteotomy and underwent microscopy when the internal fixation was unloaded from September 2017 to September 2019. Among them, there were 2 males and 9 females, aged from 55 to 64 years old. The internal and external compartment pictures of the knee were taken before and after surgery of removing the internal fixation and the International Cartilage Repair Society (ICRS) grading systerm was used to evaluate the degree of cartilage damage on the medial and lateral femoralcondyles and tibial plateau. The Westrn Ontarioand Mcmaster Universities osteoarthritis index (WOMAC) and the weight bearing line (WBL) were used to evaluate the function of the knee and the alignment of the lower limb. RESULTS: All 8 patients were followed up for more than 12 months, ranging from 12 to 22 months. The degenerated cartilage of the medial femoral condyle and medial tibial plateau was covered by newly regenerated cartilage. WOMAC score decreased from 102-127 to 41-52 and WBL was improved from 17%-34% to 58%-64%. All incisions healed in stageⅠ, and no complications such as internal fixation rupture and infection occurred during and after the operation. CONCLUSION: High tibial osteotomy can relieve the pain of the knee and the dysfunction by adjusting lower limb alignment, and the degenerated cartilage could be regenerated in the medial femoral condyle and medial tibial plateau.

Optimizing the SERS Performance of 3D Substrates through Tunable 3D Plasmonic Coupling toward Label-Free Liver Cancer Cell Classification.

Three-dimensional (3D) plasmonic nanostructures are emerging as excellent surface-enhanced Raman spectroscopy (SERS) substrates for chemical and biomedical applications. However, the correlation of 3D (including both in-plane and out-of-plane) plasmonic coupling with the SERS properties to deepen the understanding of 3D SERS substrates remains a challenge. Here, we perform correlation studies of 3D plasmonic coupling and SERS properties of the 3D hierarchical SERS substrates by tuning the multiscale structural elements. The effects of zero-dimensional (0D; the size of the building blocks), one-dimensional (1D; the thickness of the 3D substrates), and two-dimensional (2D; the composition of individual monolayers) structural elements on 3D plasmonic coupling are studied by performing UV-vis-near-infrared (NIR) spectroscopy and measuring SERS performance. It shows that both the extinction spectra and SERS enhancement are tuned at the 3D structural level. It is demonstrated that the plasmonic resonance wavelength (PRW) stemming from the 3D plasmonic coupling correlates with the SERS averaged surface enhancement factor (ASEF) and is improved by more than tenfold at the optimum 3D nanostructure. The optimized substrate is used to quantitatively analyze two small biological molecules. Moreover, as a proof-of-concept study, the substrate is first applied to differentiate between living liver normal and cancer cells with a high prediction accuracy through the spectral features of the cell membranes and the metabolites secreted outside the cells. We expect that the tuning of plasmonic coupling at the 3D level can open up new routes to design high-performance SERS substrates for wide applications.

[High tibial osteotomy combined with arthroscopy for elderly patients with knee osteoarthritis of medial compartment].

OBJECTIVE: To observe early clinical effect of high tibial osteotomy combined with arthroscopy for elderly patients with knee osteoarthritis of medial compartment. METHODS: Sixty-one elderly patients with medial compartment knee osteoarthritis were treated with high tibial osteotomy combined with arthroscopy from August 2017 to October 2018. Among them, including 17 males and 44 females, aged from 60 to 83 years old with an average of (67.87±6.45) years old. Weight bearing line (WBL) and femora-tibial angle (FTA) were analyzed to assess lower limb alignment before and 12 months after surgery. Visual analogue scale (VAS) score and Hospital for Special Surgery (HSS) score were used to evaluate knee pain and function before and 1, 3, 12 months after surgery. RESULTS: All patients were followed up from 12 to 19 months with an average of (14.27±4.69) months. WBL was improved from (14.79±5.61) % before operation to (59.33±7.82) % at 12 months after operation (t=2.294, P<0.05), FTA was improved from (182.14±2.19) ° before operation to (171.54±3.16) ° at 12 months after operation (t=1.827, P<0.05) . VAS score decreased from 6.14±2.21 before operation to 3.64±0.92, 2.02±0.63 and 0.93±0.61 at 1, 3 and 12 months after operation (F=458.24, P<0.001), HSS score increased from 49.66±13.79 to 58.39±9.26, 71.82±6.06 and 82.71±6.97 at 1, 3 and 12 months after operation (F=266.45, P<0.001) . Three patients had contralateral cortical fracture during surgery, whose osteotomy area healed well at 12 months after surgery. The incision healing of 4 cases was slow, while all healed at 3 to 4 weeks after surgery. CONCLUSION: High tibial osteotomy combined with arthroscopy could adjust lower limb alignment effectively, relieve knee pain and functional dysfunction, which indicated a significant short term efficacy on the elderly patients with knee osteoarthritis of medial compartment.

Rapid and low-cost quantitative detection of creatinine in human urine with a portable Raman spectrometer.

The creatinine concentration of human urine is closely related to human kidney health and its rapid, quantitative, and low-cost detection has always been demanded. Herein, a surface-enhanced Raman spectroscopic (SERS) method for rapid and cost-effective quantification of creatinine concentrations in human urine was developed. A Au nanoparticle solution (Au sol) was used as a SERS substrate and the influence of different agglomerating salts on its sensitivity toward detecting creatinine concentrations was studied and optimized, as well as the effect of both the salt and Au sol concentrations. The variation in creatinine spectra over time on different substrates was also examined, demonstrating reproducible quantitative analysis of creatinine concentrations in solution. By adjusting the pH, a simple liquid-liquid solvent extraction procedure, which extracted creatinine from human urine, was used to increase the SERS detection selectivity toward creatinine in complex matrices. The quantitative results were compared to those obtained with a clinically validated enzymatic "creatinine kit (CK)." The limit of detection (LOD) for the SERS technique was 1.45 mg L-1, compared with 3.4 mg L-1 for the CK method. Furthermore, cross-comparing the results from the two methods, the average difference was 5.84% and the whole SERS detection process could be completed within 2 min compared with 11 min for the CK, indicating the practicality of the quantitative SERS technique. This novel quantitative technique shows promises as a high-throughput platform for relevant clinical and forensic analysis.

Quantitative Surface-Enhanced Raman Spectroscopy through the Interface-Assisted Self-Assembly of Three-Dimensional Silver Nanorod Substrates.

The realization of surface-enhanced Raman spectroscopy (SERS) to be a reliable quantitative analytical technique requires sensitive and reproducible enhancing substrates. Here, uniform three-dimensional (3D) Ag nanorod (AgNR) substrates with well-defined interlayer spacings are prepared through the air-liquid interface-assisted self-assembly of AgNR in a layer-by-layer manner. The correlation of the SERS performance with the 3D AgNR structures is performed by SERS mapping the substrates. SERS mapping reveals the excellent enhancement uniformity of the 3D substrates with the relative standard deviation (RSD) less than 10%. It finds that both of the number of layers (NL) and the length of the AgNR have effects on the SERS performance of the 3D AgNR substrates. It is demonstrated that the intergaps between layers contribute much to the SERS intensity of the 3D AgNR by creating the interlayer (out-of-plane) plasmonic coupling. The impact of the excitation wavelengths (532, 633, and 785 nm) on SERS performance is also determined. The optimal 3D AgNR structures achieved by the correlation study is further used to detect a set of related molecules (l-tryptophan (Trp), l-phenylalanine (Phe), urea, and melamine). The 3D AgNR SERS of the analytes exhibits linear responses over wide concentration ranges. The sensitivity of the 3D AgNR SERS is proved by comparing to that of the current methods. Moreover, the 3D AgNR substrates maintain the performance stability during 4 weeks of storage.

Relationship between Lung Volume and Pulmonary Function in Patients With Adolescent Idiopathic Scoliosis: Computed Tomographic-based 3-Dimensional Volumetric Reconstruction of Lung Parenchyma.

STUDY DESIGN: Retrospective. OBJECTIVES: We determined values for the volume of right lung (Vr), left lung (Vl), total lung volume (Vt), and left/right lung volume ratio (Vl/Vr), allowing comparison between those data measured and those of age-matched controls. To find whether lung volume correlates with preoperative pulmonary function. SUMMARY OF BACKGROUND DATA: To our knowledge, no study on relationship between computed tomographic (CT) scans determined lung volume and pulmonary function test (PFT) in scoliosis have been published. METHODS: All examinations with PFT (31 cases) were identified. Three-dimensional volumetric reconstruction of lung parenchyma was performed on existing preoperative CT scans for 26 idiopathic scoliosis patients. Vl, Vr, Vt, Vl/Vr, and absolute value of right volume minus left volume (|Vr-Vl|) were calculated and correlated with PFTs. To determine if significant difference of preoperative lung volume exists between idiopathic scoliosis patients and controls. Linear regression models, using 3-dimensional lung volume parameters as predictors for vital capacity (VC), forced vital capacity (FVC), and total lung capacity (TLC), were created. RESULTS: Vt was positively correlated with VC, FVC, forced expiratory volume in 1 second (FEV1), TLC, predicted value for FVC (FVC%), predicted value for FEV1 (FEV1%), predicted value for TLC (TLC%), and predicted value for maximal ventilator volume (MVV%) (P<0.05); |Vr-Vl| was not correlated with ventilation parameters (P>0.05); Diffusion parameters were not correlated with CT-reconstructed lung volume parameters (P>0.05); male and female adolescent idiopathic scoliosis patients had less Vt, Vr, and Vl compared with those of age-matched controls (P<0.05). CONCLUSIONS: Vt was positively correlated with VC, FVC, FEV1, TLC, FVC%, FEV1%, TLC%, and MVV%. Vt, Vr, and Vl of adolescent idiopathic scoliosis patients were less than those of age-matched controls.

Self-assembly of subwavelength nanostructures with symmetry breaking in solution.

Nanostructures with symmetry breaking can allow the coupling between dark and bright plasmon modes to induce strong Fano resonance. However, it is still a daunting challenge to prepare bottom-up self-assembled subwavelength asymmetric nanostructures with appropriate gaps between the nanostructures especially below 5 nm in solution. Here we present a viable self-assembly method to prepare symmetry-breaking nanostructures consisting of Ag nanocubes and Au nanospheres both with tunable size (90-250 nm for Au nanospheres; 100-160 nm for Ag nanocubes) and meanwhile control the nanogaps through ultrathin silica shells of 1-5 nm thickness. The Raman tag of 4-mercaptobenzoic acid (MBA) assists the self-assembly process and endows the subwavelength asymmetric nanostructures with surface-enhanced Raman scattering (SERS) activity. Moreover, thick silica shells (above 50 nm thickness) can be coated on the self-assembled nanostructures in situ to stabilize the whole nanostructures, paving the way toward bioapplications. Single particle scattering spectroscopy with a 360° polarization resolution is performed on individual Ag nanocube and Au nanosphere dimers, correlated with high-resolution TEM characterization. The asymmetric dimers exhibit strong configuration and polarization dependence Fano resonance properties. Overall, the solution-based self-assembly method reported here is opening up new opportunities to prepare diverse multicomponent nanomaterials with optimal performance.

Quantitative SHINERS analysis of temporal changes in the passive layer at a gold electrode surface in a thiosulfate solution.

Shell-isolated gold nanoparticles (SHINs) were employed to record shell-isolated nanoparticle-enhanced Raman spectra (SHINERS) of a passive layer formed at a gold surface during gold leaching from thiosulfate solutions. The (3-aminopropyl)triethoxysilane (APTES) and a sodium silicate solution were used to coat gold nanoparticles with a protective silica layer. This protective silica layer prevented interactions between the thiosulfate electrolyte and the gold core of the SHINs when the SHINs-modified gold electrode was immersed into the thiosulfate lixiviant. The SHINERS spectra of the passive layer, formed from thiosulfate decomposition, contained bands indicative of hydrolyzed APTES. We have demonstrated how to exploit the presence of these APTES bands as an internal standard to compensate for fluctuations of the surface enhancement of the electric field of the photon. We have also developed a procedure that allows for removal of the interfering APTES bands from the SHINERS spectra. These methodological advancements have enabled us to identify the species forming the passive layer and to determine that the formation of elemental sulfur, cyclo-S8, and polymeric sulfur chains is responsible for inhibition of gold dissolution in oxygen rich thiosulfate solutions.

Plasmonic smart dust for probing local chemical reactions.

Locally probing chemical reactions or catalytic processes on surfaces under realistic reaction conditions has remained one of the main challenges in materials science and heterogeneous catalysis. Where conventional surface interrogation techniques usually require high-vacuum conditions or ensemble average measurements, plasmonic nanoparticles excel in extreme light focusing and can produce highly confined electromagnetic fields in subwavelength volumes without the need for complex near-field microscopes. Here, we demonstrate an all-optical probing technique based on plasmonic smart dust for monitoring local chemical reactions in real time. The silica shell-isolated gold nanoparticles that form the smart dust can work as strong light concentrators and optically report subtle environmental changes at their pinning sites on the probed surface during reaction processes. As a model system, we investigate the hydrogen dissociation and subsequent uptake trajectory in palladium with both "dust-on-film" and "film-on-dust" platforms. Using time-resolved single particle measurements, we demonstrate that our technique can in situ encode chemical reaction information as optical signals for a variety of surface morphologies. The presented technique offers a unique scheme for real-time, label-free, and high-resolution probing of local reaction kinetics in a plethora of important chemical reactions on surfaces, paving the way toward the development of inexpensive and high-output reaction sensors for real-world applications.

Surface analysis using shell-isolated nanoparticle-enhanced Raman spectroscopy.

Surface-enhanced Raman scattering (SERS) is a powerful fingerprint vibrational spectroscopy with a single-molecule detection limit, but its applications are generally restricted to 'free-electron-like' metal substrates such as Au, Ag and Cu nanostructures. We have invented a shell-isolated nanoparticle-enhanced Raman spectroscopy (SHINERS) technique, using Au-core silica-shell nanoparticles (Au@SiO(2) NPs), which makes SERS universally applicable to surfaces with any composition and any morphology. This protocol describes how to prepare shell-isolated nanoparticles (SHINs) with different well-controlled core sizes (55 and 120 nm), shapes (nanospheres, nanorods and nanocubes) and shell thicknesses (1-20 nm). It then describes how to apply SHINs to Pt and Au single-crystal surfaces with different facets in an electrochemical environment, on Si wafer surfaces adsorbed with hydrogen, on ZnO nanorods, and on living bacteria and fruit. With this method, SHINs can be prepared for use in ~3 h, and each subsequent procedure for SHINERS measurement requires 1-2 h.

Preliminary application of intraoperative CT in treatment of severe scoliosis with posterior total pedicle screws / 中国骨伤

<p><b>OBJECTIVE</b>To study the clinical effects and application value of intraoperative CT in treatment of severe scoliosis with posterior total pedicle screws.</p><p><b>METHODS</b>Thirty-two cases of severe scoliosis were retrospectively analysed in our hospital from June 2009 to June 2011,which were treated by posterior total pedicle screws with intraoperative CT including 12 males and 20 females with an average age of 16.8 years ranging from 10 to 38 years. There were 19 cases combined with thoracic kyphosis among 32 cases. Multiple planar reconstruction technology of intraoperative CT was applied to assess screw position. The numbers (rates) of pedicle screws were calculated and evaluated as different grades in upper thoracic vertebra (T1-T4) ,middle thoracic vertebra (T5-T8), lower thoracic vertebra (T9-T12) and lumbar vertebra. The pedicle screws of 2 grade and 3 grade were defined as malpositioned screws. Times of applicating intraoperative CT were calculated. Cobb angle of all cases and kyphosis angle of the cases combined with thoracic kyphosis were measured before and after surgery. Scoliosis correction rates and kyphosis correction rates were calculated.</p><p><b>RESULTS</b>There were 686 pedicle screws placed in thoracolumbar of 32 patients (including 544 thoracic pedicle screws,142 lumbar pedicle screws) and 14 patients underwent osteotomy. The rate of malpositioned screws in thoracolumbar was 7.3% by evaluating with intraoperative CT,and it respectively was 5.6%,11.1%, 6.7% and 4.3% in upper thoracic vertebra, middle thoracic vertebra,lower thoracic vertebra and lumbar vertebra. The malpositioned screws were amended in surgery. The mean times of intraoperative CT was 2.6 times (ranged from 2 times to 4 times). The mean preoperative Cobb angle was 95 degrees (ranged from 78 degrees to 123 degrees) and the mean postoperative Cobb angle was 340 (ranged from 19 degrees to 53 degrees). The mean correction rate of Cobb angle was 64%. The mean preoperative kyphosis angle of the patients combined with thoracic kyphosis was 69 degrees (ranged from 46 degrees to 82 degrees) and the mean postoperative kyphosis angle was 32 degrees (ranged from 22 degrees to 45 degrees). The mean correction rate of kyphosis angle was 54%. Four patients suffered cerebrospinal fluid leak after surgery. No infection, vascular lesion and nervous lesion were found. All patients had an average 18-month follow-up (ranged from 12 to 26 months). No broken nails, broken rods and pseudarthrosis were founded.</p><p><b>CONCLUSION</b>Application of in traoperative CT in severe scoliosis with posterior total pedicle screws can detect and amend malpositioned screws timely in surgery, to avoid secondary surgery for malpositioned screws and protect the safety of surgery. The effects of surgery is satisfactory.</p>

Dynamic changes in phenolic compounds and antioxidant activity in oats (Avena nuda L.) during steeping and germination.

Samples from naked oat were steeped and germinated under controlled conditions in an incubator. Changes of phenolic compounds and antioxidant activity were investigated in oats during steeping and germination. Results revealed that phenolic compounds and antioxidant activity of oats varied with the difference in steeping and germination stages. Compared with raw grains, short-term steeping treatment did not show significant effects (p > 0.05) on phenolic content. Germination can significantly result in the decrease in bound phenolic and the increase in free and total phenolics. Main phenolic acids and avenanthramides were isolated and quantified by HPLC analysis. During steeping, phenolic acids decreased (p < 0.05); avenanthramide N-(3',4'-dihydroxy)-(E)-cinnamoyl-5-hydroxyanthranilic acid first decreased and then increased (p < 0.05), while avenanthramides N-(4'-hydroxy)-(E)-cinnamoyl-5-hydroxyanthranilic acid and N-(4'-hydroxy-3'-methoxy)-(E)-cinnamoyl-5-hydroxyanthranilic acid did not change significantly (p > 0.05). During germination, gallic and caffeic acids first increased (p < 0.05) and then decreased, whereas p-coumaric and ferulic acids and avenanthramides increased (p < 0.05). Nevertheless, avenanthramides did not change significantly (p > 0.05) during the last stage of germination. Oat extracts exhibited increasing high antioxidant activity with the steeping and germination going on, which may explain that antioxidant activity correlated (p < 0.01) significantly with the content of phenolic compounds.