Optimizing prediction accuracy for early recurrent lumbar disc herniation with a directional mutation-guided SVM model.

Percutaneous endoscopic lumbar discectomy (PELD) is one of the main means of minimally invasive spinal surgery, and is an effective means of treating lumbar disc herniation, but its early recurrence is still difficult to predict. With the development of machine learning technology, the auxiliary model based on the prediction of early recurrent lumbar disc herniation (rLDH) and the identification of causative risk factors have become urgent problems in current research. However, the screening ability of current models for key factors affecting the prediction of rLDH, as well as their predictive ability, needs to be improved. Therefore, this paper presents a classification model that utilizes wrapper feature selection, developed through the integration of an enhanced bat algorithm (BDGBA) and support vector machine (SVM). Among them, BDGBA increases the population diversity and improves the population quality by introducing directional mutation strategy and guidance-based strategy, which in turn allows the model to secure better subsets of features. Furthermore, SVM serves as the classifier for the wrapper feature selection method, with its classification prediction results acting as a fitness function for the feature subset. In the proposed prediction method, BDGBA is used as an optimizer for feature subset filtering and as an objective function for feature subset evaluation based on the classification results of the support vector machine, which improves the interpretability and prediction accuracy of the model. In order to verify the performance of the proposed method, this paper proves the performance of the model through global optimization experiments and prediction experiments on real data sets. The accuracy of the proposed rLDH prediction model is 93.49% and sensitivity is 88.33%. The experimental results show that Level of herniated disk, Modic change, Disk height, Disk length, and Disk width are the key factors for predicting rLDH, and the proposed method is an effective auxiliary diagnosis method.

A 3-Year Survival Update from a Phase 2 Study of Paclitaxel Plus Cisplatin and 5-Fuorouracil Induction Chemotherapy for Locally Advanced Borderline-Resectable Esophageal Squamous Cell Carcinoma: The NEOCRTEC-1601 Clinical Trial.

BACKGROUND: This study updated 3-year analyses to further characterize the impact of docetaxel, cisplatin, and fluorouracil (TPF) chemotherapy followed by surgery. METHODS: This study was a single-center phase 2 clinical trial. Patients with a diagnosis of borderline resectable esophageal squamous cell carcinoma (BR-ESCC) because of the primary tumor or bulky lymph node that potentially invaded adjacent organs were eligible. The treatment started with TPF chemotherapy followed by surgery if the cancer was resectable, or by concurrent chemoradiation if it was unresectable. This updated report presents the 3-year overall survival (OS) and progression-free survival (PFS) rates. RESULTS: Surgery was performed for 27 patients (57.4%), and R0 resection was confirmed in 25 patients (53.2%). Pathologic complete response was confirmed in four patients (8.5%). The median follow-up time for the surviving patients was 44.8 months (range, 3.4-74.6 months). The median OS for all the patients was 41.9 months (95% confidence interval [CI], 18.6-65.3 months), with a median PFS of 38.7 months (95% CI, 23.5-53.9 months). The 3-year survival rate for all the patients was 54.4%. The 3-year survival rate for the R0 patients was 65.4%. CONCLUSION: Long-term follow-up evaluation confirmed that TPF followed by surgery is feasible and promising in terms of survival for BR-ESCC patients. Trial Registration ClinicalTrials.gov identifer: NCT02976909.

Deficiency of aldehyde dehydrogenase 2 aggravates ethanol-induced cytotoxicity in N2a cells via CaMKII/Drp1-mediated mitophagy.

Chronic alcohol abuse causes brain damage and has been associated with an increased risk of Alzheimer's disease. The toxic metabolite of alcohol, acetaldehyde, which is converted to acetate by aldehyde dehydrogenase 2 (ALDH2), has been shown to induce excessive mitochondrial fragmentation and dysfunction leading to neurotoxicity. However, it is still unclear how alcohol affects mitochondrial function in ALDH2-deficient cells. The present study investigated the association between abnormal mitochondrial dynamics, mitophagy and cytotoxicity in ALDH2-deficient N2a cells treated with ethanol. It was found that ethanol induced dynamin-related protein 1 (Drp1)-mediated mitochondrial fragmentation and impaired mitochondrial function, causing excessive mitophagy and cytotoxicity in ALDH2-deficient N2a cells while inducing Ca2+ influx and activating Ca2+/calmodulin-dependent protein kinase II (CaMKII). Inhibition of Ca2+ overload or CaMKII activation prevented Drp1 phosphorylation and ameliorated ethanol-induced mitophagy and cytotoxicity, indicating that Ca2+-dependent CaMKII activation was critical for mediating Drp1-dependent excessive mitochondrial fission and mitophagy in ALDH2-deficient N2a cells. The results of the present study suggested that prevention of intracellular Ca2+ overload might be beneficial for preventing neurotoxicity associated with alcohol abuse in individuals with defective ALDH2.

Identification of m5C-related molecular subtypes and prediction models in the prognosis and tumor microenvironment infiltration of soft tissue sarcoma.

Background: The epigenetic regulator in cancer progression and immune response has been demonstrated recently. However, the potential implications of 5-methylcytosine (m5C) in soft tissue sarcoma (STS) are unclear. Methods: The RNA sequence profile of 911 normal and 259 primary STS tissues were obtained from GTEx and TCGA databases, respectively. We systematically analyzed the m5C modification patterns of STS samples based on 11 m5C regulators, and comprehensively correlated these modification patterns with clinical characteristics, prognosis, and tumor microenvironment (TME) cell-infiltrating. Furthermore, an m5C-related signature was generated using Cox proportional hazard model and validated by the GSE17118 cohort. Results: Two distinct m5C modification patterns (cluster1/2) were discovered. The cluster1 had favorable overall survival, higher immune score, higher expression of most immune checkpoints, and active immune cell infiltration. The GSVA analysis of the P53 pathway, Wnt signaling pathway, G2M checkpoint, mTORC1 signaling, Wnt/ß catenin signaling, and PI3K/AKT/mTOR signaling were significantly enriched in the cluster2. Moreover, 1220 genes were differentially expressed between two clusters, and a m5C prognostic signature was constructed with five m5C-related genes. The signature represented an independent prognostic factor and showed the favorable performance in the GSE17118 cohort. Patients in the low-risk group showed higher immunoscore and higher expression of most immune checkpoints. Further GSVA analysis indicated that the levels of P53 pathway, Wnt signaling pathway, and TGF-ß signaling pathway were different between low- and high-risk groups. Moreover, a nomogram incorporating m5C signature and clinical variables was established and showed well performance. Conclusion: This work showed that the m5C modification plays a significant role in the progression of STS and the formation of TME diversity. Evaluating the m5C modification pattern of tumor will enhance our cognition of TME infiltration characterization to guide more effective immunotherapy strategies.

A phase II clinical trial of toripalimab combined with neoadjuvant chemoradiotherapy in locally advanced esophageal squamous cell carcinoma (NEOCRTEC1901).

Background: To evaluate the efficacy and safety of toripalimab combined with neoadjuvant chemoradiotherapy (NCRT) for locally advanced esophageal squamous cell carcinoma (ESCC). Methods: In this single arm, phase II trial, 44 ESCC patients were enrolled from December 2019 to July 2021 at Sun Yat-sen University Cancer Center (Guangzhou, China). All patients received concurrent radiotherapy (44 Gy in 20 fractions), chemotherapy (paclitaxel 50 mg/m2 and cisplatin 25 mg/m2 on days 1, 8, 15, and 22), and toripalimab (240 mg on days 1 and 22). Within 6-8 weeks of neoadjuvant treatment, patients underwent surgery. The results of the study patients were compared with those of 86 matched patients between July 2015 and March 2022. The primary endpoint was pathological complete response (pCR) rate, and the secondary endpoints were treatment-related adverse events and R0 rates. This trail was registered with ClinicalTrails.gov, NCT04006041. Findings: All patients received neoadjuvant treatment, and 42 completed esophagectomy. Of the 42 patients, 21 (50%; 95% CI 35-65) achieved pCR and 2 (5%) patients were ypT0N+. The R0 resection rate was 98% (41/42). Nine (20%) of 44 patients had grade 3/4 adverse events. Among the perioperative complications (n = 42), anastomotic leakage occurred in five cases (12%), tracheal fistula in three cases (7%), and postoperative death in one case (2%) due to tracheal fistula. Compared with the control cohort, the pCR rate of the study group was higher but without significant difference (50% vs. 36%, P = 0.19). Interpretation: Toripalimab combined with NCRT failed to show significantly better pCR rate than historical data. Nevertheless, considering the signs of efficacy and acceptable safety of this regimen, further evaluation in phase III randomized trials might be warranted. Funding: National Natural Science Foundation of China.

Prognostic value of L4 lymph node dissection during video-assisted thoracoscopic surgery in patients with left-sided non-small cell lung cancer: a single-center, retrospective cohort study.

Background: Lymph node dissection (LND) is crucial procedure during radical resection of non-small cell lung cancer (NSCLC), but the prognostic value of L4 LND remains elusive. To investigate the prognostic value of L4 LND in patients with left-side NSCLC who underwent video-assisted thoracoscopic surgery (VATS). Methods: Three hundred twelve patients who underwent VATS between Jan. 2007 and Dec. 2016 were reviewed. Of those, 119 underwent L4 LND (L4D+), whereas the other 193 patients did not (L4D-). The inclusion criteria were as follows: patients diagnosed with primary left-sided NSCLC who underwent VATS lobectomy combined with LND; patients subjected to R0 resection and tumor pathological stage T1-4N0-2M0. The primary endpoint was overall survival (OS). OS was calculated from the operation date to the date of death. The chi-square test was used for categorical variables, and a t test was used for continuous variables. Results: A total of 119 patients underwent L4 LND, and the procedure was more likely to be performed on upper lobe tumors (P=0.019). Patient distributions with respect to age, gender, smoking history, clinical stage, adjuvant therapy, tumor differentiation and tumor size were well balanced between two groups. More lymph nodes (LNs) were dissected in the L4D+ group than in the L4D- group (P<0.001). The rate of metastasis to L4 lymph nodes was 9.2%, which was comparable between patients with upper and lower lobe tumors (8.9% vs. 10.0%, P=1.000). The L4D+ group exhibited a significantly better OS than the L4D- group (median OS: undefined vs. 130 months, HR 0.47; 95% CI: 0.31-0.72; P=0.002). Multivariate analysis showed that L4 LND was an independent factor for OS. However, OS did not significantly differ between the two groups of cT1aN0 and cT1bN0 patients (OS: HR 0.44; 95% CI: 0.18-1.06; P=0.12). Conclusions: L4 LND is recommended for patients with left-sided NSCLC as an essential component of radical resection. The role of L4 LND in cT1a-bN0 disease warrants further study.

Impacts of neoadjuvant chemoradiotherapy on the immune landscape of esophageal squamous cell carcinoma.

BACKGROUND: Neoadjuvant chemoradiotherapy (neoCRT) followed by surgery is the most common approach for locally advanced resectable esophageal squamous cell carcinoma (ESCC) patients. How neoCRT impacts ESCC tumor immune microenvironment (TIME) has not been fully understood. METHODS: Single-cell RNA sequencing (scRNA-seq) was conducted to examine the neoCRT-driven cellular and molecular dynamics in 8 pre- and 7 post-neoCRT ESCC samples from 8 male patients. FINDINGS: scRNA-seq data of about 112,000 cells were obtained. Expression programs of cell cycle, epithelium development, immune response, and extracellular structure in pre-treatment tumor cells were related to neoCRT response. Spearman correlation between CD8+ T cells' cytotoxicity and expression of checkpoint molecules was prominent in pre-neoCRT intermediate activated/exhausted CD8+ T cells. NeoCRT increased CD8+ T cells' infiltration but promoted their exhaustion in both major and minor responders. NeoCRT promoted differentiation of Th but demoted that of Treg cells in major responders. Maturation of cDC1s and expression of M2 macrophage markers increased while the number of cDC2s decreased after neoCRT. Higher activities of immune-related pathways in pre-neoCRT CD8+ T cells and macrophages, as well as a pronounced decrease of them after neoCRT, correlated with better neoCRT response. Interactions between intermediate activated/exhausted CD8+ T and macrophages, cDC1s, and LAMP3+ cDCs decreased after neoCRT. INTERPRETATION: Our comprehensive picture of the neoCRT-related immune changes provides deeper insights into immunological mechanisms associated with ESCC response to neoCRT, which may aid in future development of immune-strategies for improving ESCC treatment. FUNDING: This work was supported by the National Natural Science Foundation of China (82072607).

Nonlinear Strong Coupling by Second-Harmonic Generation Enhancement in Plasmonic Nanopatch Antennas.

Enhanced electromagnetic fields within plasmonic nanocavity mode volumes enable multiple significant effects that lead to applications in both the linear and nonlinear optical regimes. In this work, we demonstrate enhanced second harmonic generation from individual plasmonic nanopatch antennas which are formed by separating silver nanocubes from a smooth gold film using a sub-10 nm zinc oxide spacer layer. When the nanopatch antennas are excited at their fundamental plasmon frequency, a 104-fold increase in the intensity of the second harmonic generation wave is observed. Moreover, by integrating quantum emitters that have an absorption energy at the fundamental frequency, a second order nonlinear exciton - polariton strong coupling response is observed with a Rabi splitting energy of 19 meV. The nonlinear frequency conversion using nanopatch antennas thus provides an excellent platform for nonlinear control of the light-matter interactions in both weak and strong coupling regimes which will have a great potential for applications in optical engineering and information processing.

Attention mechanism-based deep learning method for hairline fracture detection in hand X-rays.

Wrist and finger fractures detection is always the weak point of associate study, because there are small targets in X-rays, such as hairline fractures. In this paper, a dataset, consisting of 4346 anteroposterior, lateral and oblique hand X-rays, is built from many orthopedic cases. Specifically, it contains a lot of hairline fractures. An automatic preprocessing based on generative adversative network (GAN) and a detection network, called WrisNet, are designed to improve the detection performance of wrist and finger fractures. In the preprocessing, an attention mechanism-based GAN is proposed for obtaining the approximation of manual windowing enhancement. A multiscale attention-module-based generator of the GAN is proposed to increase continuity between pixels. The discriminator and the generator can achieve 93% structural similarity (SSIM) as manual windowing enhancement without manual parameter adjustment. The designed WrisNet is composed of two components: a feature extraction module and a detection module. A group convolution and a lightweight but efficient triplet attention mechanism are elaborately embedded into the feature extraction module, resulting in richer representations of hairline fractures. To obtain more accurate locating information in this condition, the soft non-maximum suppression algorithm is employed as the post-processing method of the detection module. As shown in experimental results, the designed method can have obvious average precision (AP) improvement up to 7% or more than other mainstream frameworks. The automatic preprocessing and the detection net can greatly reduce the degree of artificial intervention, so it is easy to be implemented in real clinical environment.

Acetaldehyde Induces Cytotoxicity via Triggering Mitochondrial Dysfunction and Overactive Mitophagy.

Overconsumption of alcohol damages brain tissue and causes cognitive dysfunction. It has been suggested that the neurotoxicity caused by excessive alcohol consumption is largely mediated by acetaldehyde, the most toxic metabolite of ethanol. Evidence shows that acetaldehyde impairs mitochondrial function and induces cytotoxicity of neuronal cells; however, the exact mechanisms are not fully understood. The aim of this study was to investigate the role of mitophagy in acetaldehyde-induced cytotoxicity. It was found that acetaldehyde treatment induced mitophagic responses and caused cytotoxicity in SH-SY5Y cells. The levels of light chain 3 (LC3)-II, Beclin1, autophagy-related protein (Atg) 5 and Atg16L1, PTEN-induced putative kinase (PINK)1, and Parkin were significantly elevated, while the level of p62 was reduced in acetaldehyde-treated cells. Acetaldehyde also promoted the accumulation of PINK1 and Parkin on mitochondria and caused a remarkable decrease of mitochondrial mass. Treatment with autophagy inhibitors prevented the decline of mitochondrial mass and alleviated the cytotoxicity induced by acetaldehyde, suggesting that overactive mitophagy might be an important mechanism contributing to acetaldehyde-induced cytotoxicity. Antioxidant N-acetyl-L-cysteine significantly attenuated the mitophagic responses and alleviated the cytotoxicity induced by acetaldehyde, indicating that oxidative stress was a major mediator of the excessive mitophagy induced by acetaldehyde. Taken together, these findings provided new insights into the role of mitophagy and oxidative stress in acetaldehyde-induced cytotoxicity.

Raman study of silicon telluride nanoplates and their degradation.

Silicon telluride (Si2Te3) has emerged as one of the many contenders for 2D materials ideal for the fabrication of atomically thin devices. Despite the progress which has been made in the electric and optical properties of silicon telluride, much work is still needed to better understand this material. We report here on the Raman study of Si2Te3degradation under both annealing andin situheating with a laser. Both processes caused pristine Si2Te3to degrade into tellurium and silicon oxide in air in the absence of a protective coating. A previously unreported Raman peak at ∼140 cm-1was observed from the degraded samples and is found to be associated with pure tellurium. This peak was previously unresolved with the peak at 144 cm-1for pristine Si2Te3in the literature and has been erroneously assigned as a signature Raman peak of pure Si2Te3, which has caused incorrect interpretations of experimental data. Our study has led to a fundamental understanding of the Raman peaks in Si2Te3, and helps resolve the inconsistent issues in the literature. This study is not only important for fundamental understanding but also vital for material characterization and applications.

A Novel Nomogram Model to Identify Candidates and Predict the Possibility of Benefit From Primary Tumor Resection Among Female Patients With Metastatic Infiltrating Duct Carcinoma of the Breast: A Large Cohort Study.

BACKGROUND: The impact of primary site surgery on survival remains controversial in female patients with stage IV breast cancer. The purpose of this study was to investigate the role of primary tumor surgery in patients with stage IV breast cancer and concurrently develop a nomogram to identify which patients will benefit from surgery. METHODS: We retrospectively searched the SEER database for female patients newly diagnosed with stage IV breast infiltrating duct carcinoma (BIDC) between 2010 and 2015 and then divided them into surgery and non-surgery groups. The propensity score matching (PSM) method was implemented to eliminate the bias, and Kaplan-Meier survival analysis was generated to compare the overall survival (OS) and cancer-specific survival (CSS) between the two groups. After PSM, Cox regression analyses were performed to determine the independent protective value of primary tumor surgery, while logistic regression analyses were utilized to uncover significant predictors of surgical benefit and establish a screening nomogram for female patients with stage IV BIDC. Nomogram performance was evaluated by calibration curves, receiver operating characteristic (ROC) curves, and decision curve analysis (DCA). RESULT: 5,475 patients with stage IV BIDC were included in this study, and 2,375 patients (43.38%) received primary tumor surgery. After PSM, the median CSS was 53 months (95% CI: 46.84-59.16) in the surgery group compared with only 33 months (95% CI: 30.05-35.95) in the non-surgery group. We further found that primary tumor surgery was an independent protective factor for patients with stage IV BIDC. The independent factors affecting the benefit of locoregional surgery in patients with stage IV BIDC included histological grade, T stage, molecular subtype, lung metastasis, liver metastasis, brain metastasis, and marital status. The AUC of the nomogram was 0.785 in the training set and 0.761 in the testing set. The calibration curves and DCA confirmed that the nomogram could precisely predict the possibility of benefit from primary tumor resection. CONCLUSION: Our study suggested that primary tumor surgery improved the prognosis of female patients with stage IV BIDC and developed a nomogram to quantify the probability of surgical benefit to help identify surgical candidates clinically.

Risk Factors, Prognostic Factors, and Nomograms for Distant Metastasis in Patients With Newly Diagnosed Osteosarcoma: A Population-Based Study.

Background: Osteosarcoma is the most common bone cancer, mainly occurring in children and adolescents, among which distant metastasis (DM) still leads to a poor prognosis. Although nomogram has recently been used in tumor areas, there are no studies focused on diagnostic and prognostic evaluation of DM in primary osteosarcoma patients. Methods: The data of osteosarcoma patients diagnosed between 2004 and 2015 were extracted from the Surveillance, Epidemiology, and End Results (SEER) database. Univariate and multivariate logistic regression analyses were used to identify independent risk factors for DM in osteosarcoma patients, and univariate and multivariate Cox proportional hazards regression analyses were used to determine independent prognostic factors of osteosarcoma patients with DM. We then established two novel nomograms and the results were evaluated by receiver operating characteristic (ROC) curves, calibration curves, and decision curve analysis (DCA). Result: A total of 1,657 patients with osteosarcoma were included, and 267 patients (16.11%) had DM at the time of diagnosis. The independent risk factors for DM in patients with osteosarcoma include age, grade, T stage, and N stage. The independent prognostic factors for osteosarcoma patients with DM are age, chemotherapy and surgery. The results of ROC curves, calibration, DCA, and Kaplan-Meier (K-M) survival curves in the training, validation, and expanded testing sets, confirmed that two nomograms can precisely predict occurrence and prognosis of DM in osteosarcoma patients. Conclusion: Two nomograms are expected to be effective tools for predicting the risk of DM for osteosarcoma patients and personalized prognosis prediction for patients with DM, which may benefit clinical decision-making.

Improving domain adaptation in de-identification of electronic health records through self-training.

OBJECTIVE: De-identification is a fundamental task in electronic health records to remove protected health information entities. Deep learning models have proven to be promising tools to automate de-identification processes. However, when the target domain (where the model is applied) is different from the source domain (where the model is trained), the model often suffers a significant performance drop, commonly referred to as domain adaptation issue. In de-identification, domain adaptation issues can make the model vulnerable for deployment. In this work, we aim to close the domain gap by leveraging unlabeled data from the target domain. MATERIALS AND METHODS: We introduce a self-training framework to address the domain adaptation issue by leveraging unlabeled data from the target domain. We validate the effectiveness on 4 standard de-identification datasets. In each experiment, we use a pair of datasets: labeled data from the source domain and unlabeled data from the target domain. We compare the proposed self-training framework with supervised learning that directly deploys the model trained on the source domain. RESULTS: In summary, our proposed framework improves the F1-score by 5.38 (on average) when compared with direct deployment. For example, using i2b2-2014 as the training dataset and i2b2-2006 as the test, the proposed framework increases the F1-score from 76.61 to 85.41 (+8.8). The method also increases the F1-score by 10.86 for mimic-radiology and mimic-discharge. CONCLUSION: Our work demonstrates an effective self-training framework to boost the domain adaptation performance for the de-identification task for electronic health records.

Evaluation of an electrochemically aligned collagen yarn for textile scaffold fabrication.

Collagen is the major component of the extracellular matrix in human tissues and widely used in the fabrication of tissue engineered scaffolds for medical applications. However, these forms of collagen gels and films have limitations due to their inferior strength and mechanical performance and their relatively fast rate of degradation. A new form of continuous collagen yarn has recently been developed for potential usage in fabricating textile tissue engineering scaffolds. In this study, we prepared the continuous electrochemical aligned collagen yarns from acid-soluble collagen that was extracted from rat tail tendons (RTTs) using 0.25 M acetic acid. Sodium dodecyl sulfate polyacrylamide gel electrophoresis and Fourier transform infrared spectroscopy confirmed that the major component of the extracted collagen contained alpha 1 and alpha 2 chains and the triple helix structure of Type 1 collagen. The collagen solution was processed to monofilament yarns in continuous lengths by using a rotating electrode electrochemical compaction device. Exposing the non-crosslinked collagen yarns and the collagen yarns crosslinked with 1-ethyl-3-(-3-dimethyl-aminopropyl) carbodiimide hydrochloride to normal physiological hydrolytic degradation conditions showed that both yarns were able to maintain their tensile strength during the first 6 weeks of the study. Cardiosphere-derived cells showed significantly enhanced attachment and proliferation on the collagen yarns compared to synthetic polylactic acid filaments. Moreover, the cells were fully spread and covered the surface of the collagen yarns, which confirmed the superiority of collagen in terms of promoting cellular adhesion. The results of this work indicated that the aligned RTT collagen yarns are favorable for fabricating biotextile scaffolds and are encouraging for further studies of various textile structure for different tissue engineering applications.

Anisotropic optical properties of single Si2Te3 nanoplates.

We report a combined experimental and computational study of the optical properties of individual silicon telluride (Si2Te3) nanoplates. The p-type semiconductor Si2Te3 has a unique layered crystal structure with hexagonal closed-packed Te sublattices and Si-Si dimers occupying octahedral intercalation sites. The orientation of the silicon dimers leads to unique optical and electronic properties. Two-dimensional Si2Te3 nanoplates with thicknesses of hundreds of nanometers and lateral sizes of tens of micrometers are synthesized by a chemical vapor deposition technique. At temperatures below 150 K, the Si2Te3 nanoplates exhibit a direct band structure with a band gap energy of 2.394 eV at 7 K and an estimated free exciton binding energy of 150 meV. Polarized reflection measurements at different temperatures show anisotropy in the absorption coefficient due to an anisotropic orientation of the silicon dimers, which is in excellent agreement with theoretical calculations of the dielectric functions. Polarized Raman measurements of single Si2Te3 nanoplates at different temperatures reveal various vibrational modes, which agree with density functional perturbation theory calculations. The unique structural and optical properties of nanostructured Si2Te3 hold great potential applications in optoelectronics and chemical sensing.

Fibrin sealant for esophageal anastomosis: A phase II study.

BACKGROUND: Esophagectomy is a pivotal curative modality for localized esophageal or esophagogastric junction cancer (EC or EJC). Postoperative anastomotic leakage (AL) remains problematic. The use of fibrin sealant (FS) may improve the strength of esophageal anastomosis and reduce the incidence of AL. AIM: To assess the efficacy and safety of applying FS to prevent AL in patients with EC or EJC. METHODS: In this single-arm, phase II trial (Clinicaltrial.gov identifier: NCT03529266), we recruited patients aged 18-80 years with resectable EC or EJC clinically staged as T1-4aN0-3M0. An open or minimally invasive McKeown esophagectomy was performed with a circular stapled anastomosis. After performing the anastomosis, 2.5 mL of porcine FS was applied circumferentially. The primary endpoint was the proportion of patients with AL within 3 mo. RESULTS: From June 4, 2018, to December 29, 2018, 57 patients were enrolled. At the data cutoff date (June 30, 2019), three (5.3%) of the 57 patients had developed AL, including two (3.5%) with esophagogastric AL and one (1.8%) with gastric fistula. The incidence of anastomotic stricture and other major postoperative complications was 1.8% and 17.5%, respectively. The median time needed to resume oral feeding after operation was 8 d (Interquartile range: 7.0-9.0 d). No adverse events related to FS were recorded. No deaths occurred within 90 d after surgery. CONCLUSION: Perioperative sealing with porcine FS appears safe and may prevent AL after esophagectomy in patients with resectable EC or EJC. Further phase III studies are warranted.

Plasmon-assisted random lasing from a single-mode fiber tip.

Random lasing occurs as the result of a coherent optical feedback from multiple scattering centers. Here, we demonstrate that plasmonic gold nanostars are efficient light scattering centers, exhibiting strong field enhancement at their nanotips, which assists a very narrow bandwidth and highly amplified coherent random lasing with a low lasing threshold. First, by embedding plasmonic gold nanostars in a rhodamine 6G dye gain medium, we observe a series of very narrow random lasing peaks with full-width at half-maximum ∼ 0.8 nm. In contrast, free rhodamine 6G dye molecules exhibit only a single amplified spontaneous emission peak with a broader linewidth of 6 nm. The lasing threshold for the dye with gold nanostars is two times lower than that for a free dye. Furthermore, by coating the tip of a single-mode optical fiber with gold nanostars, we demonstrate a collection of random lasing signal through the fiber that can be easily guided and analyzed. Time-resolved measurements show a significant increase in the emission rate above the lasing threshold, indicating a stimulated emission process. Our study provides a method for generating random lasing in the nanoscale with low threshold values that can be easily collected and guided, which promise a range of potential applications in remote sensing, information processing, and on-chip coherent light sources.

Research on the Integrated Navigation Technology of SINS with Couple Odometers for Land Vehicles.

Autonomous and accurate acquisition of the position and azimuth of the vehicle is critical to the combat effectiveness of land-fighting vehicles. The integrated navigation system, consisting of a strap-down inertial navigation system (SINS) and odometer (OD), is commonly applied in vehicles. In the SINS/OD integrated system, the odometer is installed around the vehicle's wheel, while SINS is usually installed on the base of the vehicle. The distance along SINS and OD would cause a velocity difference when the vehicle maneuvers, which may lead to a significant influence on the integration positioning accuracy. Furthermore, SINS navigation errors, especially azimuth error, would diverge over time due to gyro drifts and accelerometer biases. The azimuth error would cause the divergence of dead-reckoning positioning errors with the distance that the vehicle drives. To solve these problems, an integrated positioning and orientation method based on the configuration of SINS and couple odometers was proposed in this paper. The proposed method designed a high precision integrated navigation algorithm, which compensated the lever arm effect to eliminate the velocity difference between SINS and odometers. At the same time, by using the measured information of couple odometers, azimuth reference was calculated and used as an external measurement to suppress SINS azimuth error's divergence over time, thus could further improve the navigation precision of the integrated system, especially the orientation accuracy. The performance of the proposed method was verified by simulations. The results demonstrated that SINS/2ODs integrated system could achieve a positioning accuracy of 0.01% D (total mileage) and orientation accuracy of ±30″ by using SINS with 0.01°/h Fiber-Optic Gyroscope (FOGs) and 50 µg accelerometers.

The Stability of Metallic MoS2 Nanosheets and Their Property Change by Annealing.

Highly pure 1T MoS2 nanosheets were grown at 200 °C by a hydrothermal process. The effects of mild annealing on the structural and physical properties of the MoS2 were studied by heating the nanosheets in air and vacuum up to 350 °C. It was found that the annealing leads to an increase in resistivity for the nanosheets by 3 orders of magnitude, the appearance of two absorption bands in the visible range, and a hydrophilic to hydrophobic change in the surface wetting properties. Monitoring of the annealing process by Raman spectroscopy indicates that the material property changes are associated with a 1T to 2H MoS2 phase transition, with activation energies of 517 meV in air and 260 meV in vacuum. This study provides another way to control the electrical, optical, and surface properties of MoS2 nanosheets for fulfilling the needs of various applications.