[The value of multi-gene testing in benign or malign diagnosis of thyroid nodules with indeterminate cytology].

Objective: To study the diagnostic value of a multi-gene molecular testing in cytologically indeterminate thyroid nodules. Methods: From February 2018 to September 2018, patients with thyroid nodules who underwent fine needle aspiration(FNA) at Peking University Cancer Hospital were enrolled. Three hundred and sixty patients were included, consisting of 86 men and 274 women, with a mean age of 45.8 years (between 13 and 89 years old). Among 391 nodules, 141 were cytologically inderminate and 75 were resected. FNA samples underwent prospective testing using a next-generation sequencing (NGS) assay, which included 16 genes for point mutations and 26 types of gene fusions. The testing results of indeterminate nodules were compared with surgical outcomes, to determine the diagnostic performance. The results were compared with the BRAF V600E single gene mutation analysis by χ(2) test. Results: The multi-gene testing showed a sensitivity of 73.2%, specificity of 96.8%, positive predictive value of 96.8%, and negative predictive value of 73.2%. The diagnostic accuracy of multi-gene testing was significantly higher than the BRAF V600E mutation test (83.3% vs 73.6%, χ(2)=31.588, P<0.01). Conclusion: Multi-gene testing in FNA samples is an effective method to diagnose cytologically indeterminate thyroid nodules, which has a higher accuracy than BRAF V600E mutation detection.

[Fine-needle aspiration for the diagnosis of lymph node metastasis in papillary thyroid carcinoma].

Objective: To investigate the diagnostic performance of fine-needle aspiration (FNA) cytology for the detection of lateral lymph node metastases in patients with papillary thyroid carcinoma (PTC). Methods: A total of 109 lateral lymph nodes with suspicious metastases from 85 patients were retrospectively subjected to FNAC, fine-needle aspiration thyroglobulin measurement (FNATg), and FNATg/SerumTg measurement. Lymph node pathological results after surgery were taken as the gold standard. Using Mann-Whitney U test, Pearson linear model and ROC curve were used for data analysis. Results: The sensitivity, specificity and accuracy of FNATg for the diagnosis of lateral neck lymph node metastasis were respectively 93.7%, 90.0% and 93.3% and those of FNATg/SerumTg were respectively 89.9%, 90.0% and 93.2% respectively, the threshold values for FNATg and FNATg/SerumTg were 0.925 ng/ml and 1.007, respectively. The sensitivity, specificity and accuracy of FNATg combined with FNAC were respectively 91.0%,93.5% and 94.4%. The existence of thyroid tissue and the expression of serum Tg did not affect the expression of lymph node FNATg. The FNATg cutoff value of 0.925 ng/ml showed the best diagnostic performance in patients with a thyroid gland, while the FNATg/SerumTg cutoff ratio of 14.95 showed the best diagnostic performance in patients without a thyroid gland. The serum TgAb significantly interfered with the expression of FNATg in the lateral neck metastatic lymph nodes (P=0.049). Conclusions: FNATg alone or the combination of FNATg with FNAC are highly reliable in the diagnosis of lateral neck lymph node metastases in patients with PTC. The expression of TgAb may interfere with the accuracy of the diagnostic performance of FNATg.

Risk factors and score for recollapse of the augmented vertebrae after percutaneous vertebroplasty in osteoporotic vertebral compression fractures.

Our study demonstrated a high incidence of recollapse of the augmented vertebrae after PVP treatment for OVCFs. A risk score based on all significant factors can predict the rate of recollapse and gain clinical benefits to prevent recollapse in patients at high risk. BACKGROUND: Recollapse of the augmented vertebrae after percutaneous vertebroplasty (PVP) treatment for osteoporotic vertebral compression fractures (OVCFs) has obtained much attention. However, little is known about risk factors and score for recollapse of the augmented vertebrae. OBJECTIVE: To determine risk factors and furthermore develop a risk score related to recollapse of the augmented vertebrae after PVP treatment for OVCFs. METHODS: Patients who were treated with PVP for single OVCFs and met this study's inclusion criteria were retrospectively reviewed. The follow-up period was at least 2 years. Associations of recollapse with co-variates (age, gender, bone mass density [BMD] with a T-score, fracture level, intravertebral cleft [IVC], fracture type, cement volume, cement leakage, leakage into a disc, cement distribution pattern, Non-PMMA-endplate-contact [NPEC], preoperative fracture severity, reduction rate [RR], reduction angle [RA]) were analyzed and a risk score for recollapse was further developed to predict recollapse. RESULTS: A total of 152 patients were included. Recollapse group was found in 42 (27.6%) patients. Preoperative IVC, solid lump cement distribution pattern, more RR (a cutoff value of 7%) and larger RA (a cutoff value of 3°) was significantly associated with increased risk for recollapse of the augmented vertebrae. A risk score was developed based on the number of risk factors present in each patient. Patients with a score of 4 had an approximately ninefold increased risk of developing recollapse over patients with a score of 0. The receiver operating characteristic curve of the risk score generated an area under the curve of 0.899 (95% CI 0.642-0.836, P = 0.000). CONCLUSION: A risk score based on preoperative IVC, cement distribution pattern, reduction rate, and reduction angle predicts the rate of recollapse. Additional studies should aim to validate this score and inspect clinical benefits of recollapse prophylaxis in patients at high risk.

The identification and expression analysis of candidate chemosensory genes in the bird cherry-oat aphid Rhopalosiphum padi (L.).

The bird cherry-oat aphid Rhopalosiphum padi (L.) is one of the most important wheat pests with polyphagia and autumn migrants. And, chemosensory genes were thought to play a key role in insect searching their hosts, food and mate. However, a systematic identification of the chemosensory genes in this pest has not been reported. Thus, in this study, we identified 14 odorant-binding proteins, nine chemosensory proteins, one sensory neuron membrane protein, 15 odorant receptors, 19 gustatory receptors and 16 ionotropic receptors from R. padi transcriptomes with a significantly similarity (E-value < 10-5) to known chemosensory genes in Acyrthosiphon pisum and Aphis gossypii. In addition, real-time quantitative polymerase chain reaction (RT-qPCR) was employed to determine the expression profiles of obtained genes. Among these obtained genes, we selected 23 chemosensory genes to analyze their expression patterns in different tissues, wing morphs and host plants. We found that except RpOBP1, RpOBP3, RpOBP4 and RpOBP5, the rest of the selected genes were highly expressed in the head with antennae compared with body without head and antennae. Besides that, the stimulation and depression of chemosensory genes by plant switch indicated that chemosensory genes might be involved in the plant suitability assessment. These results not only provide insights for the potential roles of chemosensory genes in plant search and perception of R. padi but also provide initial background information for the further research on the molecular mechanism of the polyphagia and autumn migrants of it. Furthermore, these chemosensory genes are also the candidate targets for pest management control in future.

Geometry-dependent band shift and dielectric modification of nanoporous Si nanowires.

In order to obtain a detailed understanding of the modulation of electronic properties in nanoporous Si (np-Si) nanowires with containing ordered, nanometer-sized cylindrical pores, we propose a theoretical method to clarify the band shift and associated with the dielectric modification determined by the geometrical parameters, including nanowire diameter, pore size, pore spacing and porosity, in terms of size-dependent surface energy and atomic-bond-relaxation correlation mechanism. Our results reveal that the self-equilibrium strain induced by the atoms located at inner and outer surfaces with high ratio of under-coordinated atoms as well as elastic interaction among pores in np-Si nanowires play the dominant role in the bandgap shift and dielectric depression. The tunable electronic properties of np-Si nanowires with negative curvature make them attractive for nanoelectronic and optoelectronic devices.

[Risk factors of hypoparathyroidism following total or near total thyroidectomy].

OBJECTIVE: To study the risk factors for postoperative hypoparathyroidism or hypocalcemia. METHODS: Totally 414 patients with thyroid diseases who underwent total or near total thyroidectomy at Department of Head and Neck Surgery, Peking University Cancer Hospital and Institute from June 2007 to June 2014 were studied retrospectively. There were 119 male and 295 female patients with a median age of 47 years. The clinical and pathological features that related to post-operative hypoparathyroidism were studied by χ(2) test and multivariate Logistic regression analysis. RESULTS: Of the 414 patients, 36.2% developed transient hypocalcemia, 36.5% developed transient hypoparathyroidism, 2.2% developed permanent hypoparathyroidism. In regression analysis, unilateral or bilateral center lymph node dissection were associated with mild transient hypocalcemia after surgery (OR=2.366, P=0.022; OR=5.216, P=0.000); unilateral or bilateral center lymph node dissection as well as surgical options were significant risk factors for severe transient hypocalcemia (OR=4.029, P=0.001; OR=8.384, P=0.000; OR=2.073, P=0.017) and hypoparathyroidism (OR=1.755, P=0.040; OR=4.144, P=0.000; OR=2.287, P=0.000). The parathyroid hormone concentration on postoperative day 1 was an independent risk factor for permanent hypoparathyroidism (OR=2.011, P=0.014). The concentration of parathyroid hormone threshold <5.28 ng/L was a predictor to permanent hypoparathyroidism with accuracy of 95.0%. CONCLUSIONS: Bilateral center lymph node dissection is a risk factor of permanent hypoparathyroidism in patients received total thyroidectomy should be taken thoughtfully. The parathyroid hormone concentration on postoperative day 1 provides better prediction for persistent hypoparathyroidism.

Size-dependent optical absorption modulation of Si/Ge and Ge/Si core/shell nanowires with different cross-sectional geometries.

We present an atomic-level and quantitative study of the absorption properties in Si/Ge and Ge/Si core/shell nanowires (CSNWs) along [110] direction with different cross-sectional geometries using the atomic bond relaxation method. We find that the strain existing in self-equilibrium state of CSNWs and associated with elastic energy originating from interface mismatch and surface relaxation affect the band shift and absorption properties. Compared to the CSNWs with tetragonal, hexagonal and circular shapes, the triangular CSNWs have the largest band gap shift at a fixed strain and the smallest absorption coefficient at a determinate incident light wavelength. The tunable absorption property, realized by controlling the size and geometry structure, could be helpful for nanoelectronic applications.

Anomalous interface adhesion of graphene membranes.

In order to understand the anomalous interface adhesion properties between graphene membranes and their substrates, we have developed a theoretical method to calibrate the interface adhesion energy of monolayer and multilayer graphene on substrates based on the bond relaxation consideration. Four kinds of interfaces, including graphene/SiO2, graphene/Cu, graphene/Cu/Ni and Cu/graphene/Ni, were taken into account. It was found that the membrane thickness and the interface confinement condition determine the adhesion energy. The relationship between the critical interface separation and the graphene thickness showed that the interface separation in the self-equilibrium state drops with decreasing membrane thickness. The size-dependent Young's modulus of graphene membrane and the interfacial condition were responsible for the novel interface adhesion energy. The proposed theory was expected to be applied to the design of graphene-based devices.