Comparison of the Short-Term Efficacy of Percutaneous Endoscopic Thoracic Decompression and Laminectomy in the Treatment of Thoracic Ossification of the Ligamentum Flavum

OBJECTIVE

This study aimed to investigate the short-term efficacy of percutaneous endoscopic thoracic decompression (PETD) under local anesthesia and traditional posterior thoracic laminectomy (PTL) in treating single-segment thoracic ossification of the ligamentum flavum (T-OLF).

METHODS

This was a retrospective review of the clinical information of 52 patients with T-OLF between September 2017 and September 2021. Based on the inclusion criteria, a total of 52 patients were included in the present research, 26 in the PETD group and 26 in the PTL group. The general preoperative data, intraoperative surgical conditions, preoperative and postoperative clinical information, and complications were collected. The modified Japanese Orthopedic Association score and recovery rate were evaluated preoperatively and at 3, 6, and 12 months postoperatively.

RESULTS

There was no statistically significant difference in the baseline parameters in either group (P > 0.05). There were statistically significant differences in operation time (94.62 vs. 144.62 minute) and blood loss (22.12 vs. 287.69 mL) between the PETD group and the PTL group. The modified Japanese Orthopedic Association score in the 2 groups improved from (5.46 ± 1.10) and (5.69 ± 1.01) preoperatively to (9.08 ± 0.90) and (8.88 ± 1.07) at 12 months postoperatively. The recovery rate was 84.6% in the PETD group and 76.9% in the PTL group. In addition, the complications in the PETD group were fewer than those in the PTL group.

CONCLUSIONS

The PETD under local anesthesia for T-OLF has many advantages, such as high patient acceptance, good short-term clinical outcomes, and few complications; therefore, this procedure should be promoted as a viable treatment option for T-OLF.

Risk factors for recollapse of new vertebral compression fractures after percutaneous kyphoplasty in geriatric patients: establishment of a nomogram

Background

The main objective of this study was to investigate the risk factors for recollapse of new vertebral compression fractures (NVCFs) after percutaneous kyphoplasty (PKP) treatment for osteoporotic vertebral compression fracture (OVCF) and to construct a new nomogram model.

Methods

We retrospectively analysed single-level OVCFs from January 2017 to June 2020, randomizing patients to a training set and a testing set. In the training set, independent risk factors for NVCFs in OVCF patients treated with PKP were obtained by univariate and multivariate regression analyses. These risk factors were then used as the basis for constructing a nomogram model. Finally, internal validation of the built model was performed in the testing set using the consistency index (C-index), receiver operating characteristic (ROC) curves, calibration curves and decision curve analysis (DCA).

Results

In total, 371 patients were included in this study. NVCFs occurred in 21.7% of the training set patients, and multivariate regression analysis showed that a low Hounsfield unit (HU) value, cement leakage, and thoracolumbar (TL) junction fracture were independent risk factors for NVCF after PKP. The C-index was 0.81 (95% CI: 0.74–0.81), and the validation showed that the predicted values of the established model were in good agreement with the actual values.

Conclusions

In this study, three independent risk factors were obtained by regression analysis. A nomogram model was constructed to guide clinical work and to make clinical decisions relatively accurately to prevent the occurrence of vertebral recollapse fractures.

Establishment and Validation of a Nomogram for the Risk of New Vertebral Compression Fractures After Percutaneous Vertebroplasty in Patients With Osteoporotic Vertebral Compression Fractures: A Retrospective Study

Purpose

New vertebral compression fractures(NVCFs) after minimally invasive surgery in patients with osteoporotic vertebral compression fracture (OVCF) is a challenging issue worldwide. Predicting the occurrence of NVCFs is key to addressing such questions. Therefore, we aimed to investigate the risk factors for patients who developed NVCFs after undergoing surgical treatment and establish a nomogram model to reduce the occurrence of NVCFs.

Methods

This study is a retrospective analysis that collected the general characteristics and surgical features of patients who underwent surgical treatment at 2 central institutions between January 2017 and December 2020. Patients were divided into training and testing sets based on the presence or absence of NVCFs. Independent risk factors for NVCFs were obtained in the training set of patients, and then a nomogram model was constructed. Internal and external validation of the nomogram model was performed using the consistency index (C index), receiver operating characteristic curve(ROC), calibration curves, and decision curve analysis (DCA).

Results

A total of 562 patients were included in this study. Patients from the first center were used for nomogram construction and internal validation, and patients from the second center were used as an external validation population. Multivariate regression analysis showed that age, Hounsfield unit (Hu) value, cement leakage, and thoracolumbar (TL) junction fracture were independent risk factors for NVCFs after minimally invasive surgery. The C index was .85, and the validation of internal and external validation shows that the predicted values of the established model is in good agreement with the actual values.

Conclusions

In this study, 4 independent risk factors were obtained by regression analysis, and a nomogram model was constructed to guide clinical work. The application of this model can help surgeons to make more accurate judgments to prevent the occurrence of NVCFs.

Surface-state Coulomb repulsion accelerates a metal-insulator transition in topological semimetal nanofilms

The emergence of quantization at the nanoscale, the quantum size effect (QSE), allows flexible control of matter and is a rich source of advanced functionalities. A QSE-induced transition into an insulating phase in semimetallic nanofilms was predicted for bismuth a half-century ago and has regained new interest with regard to its surface states exhibiting nontrivial electronic topology. Here, we reveal an unexpected mechanism of the transition by high-resolution angle-resolved photoelectron spectroscopy combined with theoretical calculations. Anomalous evolution and degeneracy of quantized energy levels indicate that increased Coulomb repulsion from the surface states deforms a quantum confinement potential with decreasing thickness. The potential deformation strongly modulates spatial distributions of quantized wave functions, which leads to acceleration of the transition beyond the original QSE picture. This discovery establishes a complete picture of the long-discussed transition and highlights a new class of size effects dominating nanoscale transport in systems with metallic surface states.

Revealing interfacial disorder at the growth-front of thick many-layer epitaxial graphene on SiC: a complementary neutron and X-ray scattering investigation

Epitaxial graphene on SiC provides both an excellent source of high-quality graphene as well as an architecture to support its application. Although single-layer graphene on Si-face SiC has garnered extensive interest, many-layer graphene produced on C-face SiC could be significantly more robust for enabling applications. Little is known, however, about the structural properties related to the growth evolution at the buried interface for thick many-layer graphene. Using complementary X-ray scattering and neutron reflectivity as well as electron microscopy, we demonstrate that thick many-layer epitaxial graphene exhibits two vastly different length-scales of the buried interface roughness as a consequence of the Si sublimation that produces the graphene. Over long lateral length-scales the roughness is extremely large (hundreds of Å) and it varies proportionally to the number of graphene layers. In contrast, over much shorter lateral length-scales we observe an atomically abrupt interface with SiC terraces. Graphene near the buried interface exhibits a slightly expanded interlayer spacing (∼1%) and fluctuations of this spacing, indicating a tendency for disorder near the growth front. Nevertheless, Dirac cones are observed from the graphene while its domain size routinely reaches micron length-scales, indicating the persistence of high-quality graphene beginning just a short distance away from the buried interface. Discovering and reconciling the different length-scales of roughness by reflectivity was complicated by strong diffuse scattering and we provide a detailed discussion of how these difficulties were resolved. The insight from this analysis will be useful for other highly rough interfaces among broad classes of thin-film materials.

Starter feeding altered ruminal epithelial bacterial communities and some key immune-related genes' expression before weaning in lambs

To characterize changes in ruminal epithelial bacterial communities and immune-related gene expression during concentrate starter feeding before weaning in lambs, 6 pairs of 10-d-old Hu lamb twins were selected: 1 kid received milk (M, = 6), and the other received milk plus starter (M+S, = 6). All lambs received hay and water ad libitum and were slaughtered at 56-d-old. Their rumen fluid was collected to determine ruminal pH and VFA levels; rumen epithelia were collected to characterize their bacterial communities using Illumina MiSeq sequencing and to determine mRNA expression of immune-related genes using quantitative real-time PCR (qRT-PCR). Results showed that starter feeding caused a decreased ruminal pH ( = 0.004) and increased concentrations of acetate, propionate, butyrate, and total VFA ( < 0.001). Principal coordinate analysis and analysis of molecular variance revealed that starter feeding affected ruminal epithelial bacterial communities in the lambs ( = 0.001), with higher relative abundance of dominant taxa , unclassified BS11 gut group, , unclassified Synergistaceae, , , , , and ( < 0.05) but lesser relative abundance of , unclassified Bacteroidales, unclassified Candidate, unclassified RF9, and ( < 0.05). Additionally, a phylogenetic investigation of communities by reconstruction of unobserved states analysis indicated that starter feeding markedly increased relative abundance values of dominant ruminal epithelial bacterial-inferred genes related to other ion-coupled transporters, pentose and glucuronate interconversions, glycosyltransferases, other glycan degradation, AA metabolism, sphingolipid metabolism, biotin metabolism, glycosphingolipid biosynthesis-globo series, and lysosome ( < 0.05) but decreased relative abundance values of genes related to carbon fixation pathways in prokaryotes and energy metabolism ( < 0.05) in the lambs. The qRT-PCR results showed that starter feeding decreased the relative mRNA expression of IL-6 ( = 0.003), IL-10 ( = 0.013), and interferon γ ( = 0.003). Collectively, this study showed that starter feeding could alter ruminal epithelial bacterial communities and some key immune-related genes' expression in preweaned lambs. All these responses of ruminal epithelial bacteria and the immune system would be beneficial for starter-fed lambs to be weaned.

Interfacial bonding and structure of Bi2Te3 topological insulator films on Si(111) determined by surface x-ray scattering

Interfacial topological states are a key element of interest for topological insulator thin films, and their properties can depend sensitively on the atomic bonding configuration. We employ in situ nonresonant and resonant surface x-ray scattering to study the interfacial and internal structure of a prototypical topological film system: Bi2Te3 grown on Si(111). The results reveal a Te-dominated buffer layer, a large interfacial spacing, and a slightly relaxed and partially strained bottom quintuple layer of an otherwise properly stacked bulklike Bi2Te3 film. The presence of the buffer layer indicates a nontrivial process of interface formation and a mechanism for electronic decoupling between the topological film and the Si(111) substrate.

Visualizing electronic chirality and Berry phases in graphene systems using photoemission with circularly polarized light

Electronic chirality near the Dirac point is a key property of graphene systems, which is revealed by the spectral intensity patterns as measured by angle-resolved photoemission spectroscopy under various polarization conditions. Specifically, the strongly modulated circular patterns for monolayer (bilayer) graphene rotate by ±90° (±45°) in changing from linearly to circularly polarized light; these angles are directly related to the phases of the wave functions and thus visually confirm the Berry's phase of π (2π) around the Dirac point. The details are verified by calculations.

Passage from spin-polarized surface states to unpolarized quantum well states in topologically nontrivial Sb films

Topological materials have unusual surface spin properties including a net surface spin current protected by the bulk symmetry properties. When such materials are reduced to thin films, their gapless spin-polarized surface states must connect, by analytic continuation, to bulk-derived quantum-well states, which are spin-unpolarized in centrosymmetric systems. The nature of this passage in a model system, Sb films, is investigated. Angle-resolved photoemission shows a smooth transition, while calculations elucidate the correlated evolution of the spin and charge distributions in real space.

Phonon-induced gaps in graphene and graphite observed by angle-resolved photoemission

Mapping by angle-resolved photoemission spectroscopy of the spectral functions of graphite and graphene layers at low temperatures reveals a heretofore unreported gap of ~ 67 meV at normal emission. This gap persists to room temperature and beyond, and diminishes for increasing emission angles. We show that this gap arises from electronic coupling to out-of-plane vibrational modes at the K(¯) point in the surface Brillouin zone in accordance with conservation laws and selection rules governed by quantum mechanics. Our study suggests a new approach for characterizing phonons and electron-phonon coupling in solids.

Neoadjuvant chemoradiotherapy for locally advanced low-lying rectal cancer

e15095

Objective: The aim of this trial was to explore the possibility of further improvement of efficacy in neoadjuvant chemoradiation for the treatment of locally advanced low-lying rectal cancer and the management of patients with clinical complete regression. Methods: 192 cases with locally advanced low-lying rectal cancer (T3/T4 or N+) received preoperative radiotherapy comprising 40–46 Gy/20–23 fractions and concomitant oral capecitabine 625 mg/m2 bid for 10 weeks prior to surgery. Curative resection with TME was carried out 6 weeks after the end of radiation. Results: Patients (pts) were recruited from May 2001 through August 2007. Overall, 117 pts (60.9%) experienced adverse events but only 2 suffered from grade 3 hand-foot syndrome. 17 pts (8.9%) had clinical complete tumor regression without surgery, 175 pts underwent curative resection including of 134 pts with low anterior resection (LAR), 32 pts with ultra-low anterior resection with Parks’ coloanal anastomosis and among them 6 pts with diverting temporary colostomy and 9 pts with APR. Sphincter preservation was achieved in 95.3%. Pathologically, 24 pts (12.5%) showed CR together with 17 pts with clinical CR; the overall CR rate was 21.4%. According to the pathological staging: T0N0 41 cases, T2N0 43 cases, T3N0 77 cases, T4N0 5 cases, T2N1 11 cases, T3N1 13 cases, T4N0 5 cases, and T4N1 2 cases; in semiquantitative Dworak's tumor regression grade, TRG0 8 pts,TRG1 32, TRG2 28,TRG3 83 and TRG4 41 with an overall tumor downstaging of 79.2%. There were no operative deaths, 5 pts suffered from rectovaginal fistulas and 4 anastomotic leakages with an overall anastomotic leakage rate of 5.1% (9/175) and all recovered without further events. All patients have been followed up for a median of 46 months (range 12–87). During the time, 11 pts had lung metastases, 6 liver metastases and 7 had local recurrences. The 3-year disease-free survival was 86.6% and overall survival was 92.6%. Conclusions: Neoadjuvant chemoradiotherapy has high efficacy resulting in tumor down-staging, increased resectability and sphincter preservation, and a reduction in local recurrences. Meanwhile those patients with clinical complete response can be followed up closely and safely without surgery.

No significant financial relationships to disclose.

[Study on the needle biopsies of 100 prostatic adenocarcinoma]

OBJECTIVE

To study the morphological diagnostic criteria of prostatic adenocarcinoma in needle biopsy.

METHODS

250 cases of prostatic needle biopsy including 100 cases of adenocarcinoma were observed retrospectively. The diagnostic significance of 20 parameters of morphological criteria including the architectural changes, cytologic features, invasion and some additional histologic features (intraepithelial neoplasm, intraluminal crystelloid body, intraluminal basophilic mucin secretion, collagen nodule and coagulative necrosis) were analyzed.

RESULTS

All 20 parameters of morphological criteria had practical significance in pathologic diagnosis, the most significant ones being architectural changes, prominent nucleoli, perineural and stromal invasion.

CONCLUSION

The diagnosis of prostatic adenocarcinoma is based on a constellation of cytologic and architectural features.