Theoretical Study on the Electronic Structure and Transition Properties of Low Excited States of SeCl.

For the first time, the spectroscopy and transition properties of SeCl+ are systematically reported. The potential energy curves of 22 Λ - S states and the corresponding 51 Ω states in the first and second dissociation channels of SeCl+ are calculated using the internally contracted multiconfiguration interaction and Davidson correction method. The phenomenon of avoided crossing in Ω states below 30,000 cm-1 is discussed in detail. The spectroscopy constants are obtained by fitting the potential energy curves, and also the Franck-Condon factors and radiation lifetimes of the X3Σ0+- ↔ 21Σ0++ transition are calculated. Between X3Σ0+- and 21Σ0++, the Franck-Condon factors are large, close to 1, but the radiation lifetime is large too. According to the calculation results, it is determined that direct laser cooling of SeCl+ is considered infeasible.

Ab Initio Calculation of Ground- and Low-Excited-State Spectroscopic Data and Transition Properties of SBr.

In this paper, potential energy curves of Λ-S and Ω states of SBr+ are reported for the first time, and the spectrum data of some low excited bound states are obtained. The differences in the spectrum properties of main-group molecules and SBr+ were compared and analyzed, providing a sufficient theoretical basis for the subsequent study of main-group molecules. The avoided crossing that occurs in the Ω state is analyzed, and finally it is concluded that this phenomenon mainly occurs in the energy region between 20,000 and 40,000 cm-1 that is relative to the minimum energy value. Potential transitions in the Ω state capable of achieving laser cooling of SBr+ are explored. The Franck-Condon factor, radiation lifetime, and Einstein coefficient between X3Σ0+- and b1Σ0++ are calculated. From the calculation results, we concluded that direct laser cooling of SBr+ is not feasible. What we have studied in this paper provides a theoretical basis for subsequent computational exploration of the spectrum properties of SBr+.

Application of Gemstone Spectral Computed Tomography Imaging in the Characterization of Solitary Pulmonary Nodules: Preliminary Result.

OBJECTIVE: This study aimed to observe the value of computed tomography (CT) spectral imaging parameters in the diagnosis of solitary pulmonary nodules, during the contrast-enhanced early phase and late phase. MATERIALS AND METHODS: This study was approved by the institutional review board and written informed consent was obtained from all patients. One hundred thirty-nine patients with solitary pulmonary nodules proved by pathology underwent double-phase enhanced CT scan using gemstone spectral imaging mode on a Discovery CT750 HD, and were divided into an active inflammatory group (43 cases), a malignant group (65 cases), and a tuberculosis group (31 cases). The slope rate was calculated from the spectral curve. Iodine concentrations (ICs) were derived from iodine-based material decomposition CT images and normalized to the IC in the aorta. The Kruskal-Wallis test and Nemenyi test were performed to compare quantitative parameters among the 3 groups or between each of the 2 groups. RESULTS: There were significant differences in the slope rate, IC, and normalized IC (NIC) among the 3 groups. In the active inflammatory group, malignant group, and tuberculosis group, the mean slope rate were 3.03 ± 0.71 (SD), 1.96 ± 0.91, and 1.37 ± 0.43, respectively, during the early phase and 3.28 ± 0.67, 2.24 ± 0.82, and 1.67 ± 0.64, respectively, during the late phase. The ICs were 2.68 mg/mL ± 0.56, 1.65 mg/mL ± 0.76, and 1.10 mg/mL ± 0.34, respectively, during the early phase and 2.79 mg/mL ± 0.57, 1.90 mg/mL ± 0.71, and 1.29 mg/mL ± 0.44, respectively, during the late phase. The NIC were 0.24 ± 0.06, 0.16 ± 0.04, and 0.10 ± 0.04, respectively, during the early phase and 0.57 ± 0.10, 0.43 ± 0.11, and 0.25 ± 0.09, respectively, during the late phase. The mean slope rate, IC, and NIC for the active inflammatory group were significantly higher than these parameters for the malignant group (P < 0.05), and the parameters for malignant group were significantly higher than the tuberculosis group (P < 0.05). CONCLUSIONS: Dual-energy CT gemstone spectral imaging provides a novel method to better characterize pulmonary nodules in double-phase contrast-enhanced scanning.

Diagnostic value of computed tomography scanning in differentiating malignant from benign solitary pulmonary nodules: a meta-analysis.

An early diagnosis of lung cancer is crucial for early treatment and management. The objective of this systematic review was to assess the overall diagnostic accuracy of chest computed tomography (CT) scanning in differentiating malignant from benign solitary pulmonary nodules (SPNs) with meta-analysis. The PubMed and China National Knowledge Infrastructure (CNKI) database were searched for eligible studies published up to March 2014. The sensitivity, specificity, and other measures of accuracy of chest CT scanning in the diagnosis of SPNs were pooled along with 95 % confidence intervals (CI). Summary receiver operating characteristic (ROC) curves were used to summarize overall test performance. Thirty-two studies met our inclusion criteria. The summary estimates for chest CT scanning in the diagnosis of SPNs in the meta-analysis were as follows: pooled sensitivity, 0.89 (95 % CI, 0.88 to 0.91); pooled specificity, 0.70 (95 % CI, 0.68 to 0.73); positive likelihood ratio, 2.88 (95 % CI, 2.46 to 3.37); negative likelihood ratio, 0.16 (95 % CI, 0.12 to 0.21); and diagnostic odds ratio, 23.83 (95 % CI, 16.18 to 35.11). The results indicate that CT scanning has relatively high sensitivity and moderate specificity for the diagnosis of SPNs. Given the low cost and growing prevalence of the technology, CT scanning should be recommended as the initial test for the evaluation of SPNs.

Differentiation of pheochromocytoma and adrenal lipoid adenoma by radiomics: are enhanced CT scanning images necessary?

Purpose: To establish various radiomics models based on conventional CT scan images and enhanced CT images, explore their value in the classification of pheochromocytoma (PHEO) and lipid-poor adrenal adenoma (LPA) and screen the most parsimonious and efficient model. Methods: The clinical and imaging data of 332 patients (352 lesions) with PHEO or LPA confirmed by surgical pathology in the Affiliated Hospital of Qingdao University were retrospectively analyzed. The region of interest (ROI) on conventional and enhanced CT images was delineated using ITK-SNAP software. Different radiomics signatures were constructed from the radiomics features extracted from conventional and enhanced CT images, and a radiomics score (Rad score) was calculated. A clinical model was established using demographic features and CT findings, while radiomics nomograms were established using multiple logistic regression analysis.The predictive efficiency of different models was evaluated using the area under curve (AUC) and receiver operating characteristic (ROC) curve. The Delong test was used to evaluate whether there were statistical differences in predictive efficiency between different models. Results: The radiomics signature based on conventional CT images showed AUCs of 0.97 (training cohort, 95% CI: 0.95∼1.00) and 0.97 (validation cohort, 95% CI: 0.92∼1.00). The AUCs of the nomogram model based on conventional scan CT images and enhanced CT images in the training cohort and the validation cohort were 0.97 (95% CI: 0.95∼1.00) and 0.97 (95% CI: 0.94~1.00) and 0.98 (95% CI: 0.97∼1.00) and 0.97 (95% CI: 0.94∼1.00), respectively. The prediction efficiency of models based on enhanced CT images was slightly higher than that of models based on conventional CT images, but these differences were statistically insignificant(P>0.05). Conclusions: CT-based radiomics signatures and radiomics nomograms can be used to predict and identify PHEO and LPA. The model established based on conventional CT images has great identification and prediction efficiency, and it can also enable patients to avoid harm from radiation and contrast agents caused by the need for further enhancement scanning in traditional image examinations.

Study on the spectroscopy and transition properties of TeCl.

For the first time, the spectroscopy data of TeCl+ ion and the transition data between low excited states are systematically calculated. The potential energy curves of 22 Λ-S states and 51 Ω states are calculated by the internally contracted multiconfiguration interaction and Davidson correction method. By solving the one-dimensional radial Schrödinger equation, the spectroscopy data of Λ-S states and Ω states are obtained. The phenomenon of avoided crossing in Ω state is analyzed in detail, which is mainly concentrated in the region of 20000 cm-1 to 35000 cm-1. The Franck-Condon factors, Einstein coefficients and spontaneous radiative lifetimes of [Formula: see text] transitions are calculated. According to the calculation results, it is preliminarily judged that the direct laser cooling of TeCl+ ion is not feasible.

Imaging Characteristics of Invasive Pulmonary Fungal Infection Secondary to Hematological Diseases and Comparison before and after Treatment.

Fungal infections have become crucial factors that threaten the prognosis and survival of blood disease patients. Here, we aim to analyze the epidemiological characteristics and early and advanced CT (computed tomography) manifestations of patients with invasive pulmonary fungal infections secondary to blood system diseases. 65 hospitalized patients from October 2018 to October 2020 with invasive pulmonary fungal infections secondary to blood diseases were enrolled. Blood diseases were recorded according to clinical and imaging data, and the serum galactomannan test (GM test) was conducted. Two senior radiologists analyzed the CT data and recorded the distribution of the lesions and CT signs. We analyzed and counted the first chest CT scan images of patients with nodule/mass type secondary to hematological diseases and invasive pulmonary fungal infection. The first CT nodules or mass-type lesions were statistically significant in nodule size, the number of lesions, distribution, and accompanying signs. Pulmonary fungal infection was common in both lungs during 7-day, 14-day, and 30-day follow-up CT. We also found that the nodular mass type was the main manifestation in the positive group of the GM test. Both the positive group and the negative group had the highest incidence of nodules. The incidence of air crescent signs in nodules or mass lesions in the positive group was higher than in the negative group, and the difference was statistically significant. To conclude, follow-up CT signs after antifungal treatment were highly sensitive to the early diagnosis of hematological diseases and secondary invasive pulmonary Eumycetes infection, which could be used for clinical treatment to provide help. GM test results were also related to CT manifestations such as air crescent sign, cavity, and halo sign.

CT Radiomics Model for Predicting the Ki-67 Index of Lung Cancer： An Exploratory Study.

OBJECTIVE: To establish a radiomics signature and a nomogram model based on enhanced CT images to predict the Ki-67 index of lung cancer. METHODS: From January 2014 to December 2018, 282 patients with lung cancer who had undergone enhanced CT scans and Ki-67 examination within 2 weeks were retrospectively enrolled and analyzed. The clinical data of the patients were collected, such as age, sex, smoking history, maximum tumor diameter and serum tumor markers. Our primary cohort was randomly divided into a training group (n=197) and a validation group (n=85) at a 7:3 ratio. A Ki-67 index ≤ 40% indicated low expression, and a Ki-67 index > 40% indicated high expression. In total, 396 radiomics features were extracted using AK software. Feature reduction and selection were performed using the lasso regression model. Logistic regression analysis was used to establish a multivariate predictive model to identify high and low Ki-67 expression in lung cancer. A nomogram integrating the radiomics score was established based on multiple logistic regression analysis. Area under the curve (AUC) was used to evaluate the prediction efficiency of the radiomics signature and nomogram. RESULTS: The AUC,sensitivity, specificity and accuracy of the radiomics signature in the training and validation groups were 0.88 (95% CI: 0.82~0.93),79.2%,84.3%,81.2% and 0.86 (95% CI: 0.78~0.94),74.6%,88.1%,79.8%, respectively. A nomogram combining radiomics features and clinical risk factors (smoking history and NSE) was developed. The AUC, sensitivity, specificity and accuracy were 0.87 (95% CI: 0.80~0.95), 75.0%, 90.2% and 83.5% in the validation group, respectively. CONCLUSION: The radiomics signature and nomogram based on enhanced CT images provide a way to predict the Ki-67 expression level in lung cancer.

A retrospective analysis of the risk factors associated with systemic air embolism following percutaneous lung biopsy.

In the present study, the risk factors for systemic air embolism as a complication of percutaneous CT-guided lung biopsy were explored. Data from 2,026 percutaneous CT-guided lung biopsy procedures were retrospectively analyzed. All cases were divided into a concurrent air embolism group and a control group, depending on whether air embolism occurred during the puncture process. A systemic air embolism was confirmed when CT values <-200 Hounsfield units were observed in two sequential images. A total of 19 cases (0.9%) of air embolism were detected among the 2,026 patients subjected to percutaneous CT-guided lung biopsy procedures. The most frequently detected embolism site was the left ventricle (89.5%). Only 3 cases (15.8%) were accompanied by obvious clinical symptoms. The results indicated that a puncture location above the level of the left atrium and coughing during the procedure significantly altered the likelihood of embolism developing (P=0.002 and P=0.014 vs. control, respectively). In conclusion, a puncture lesion above the level of the left atrium and coughing during the procedure may be risk factors for air embolism development.

Synthesis, bioactivity and SAR study of N'-(5-substituted-1,3,4-thiadiazol-2-yl)-N-cyclopropylformyl-thioureas as ketol-acid reductoisomerase inhibitors.

Ketol-acid reductoisomerase (KARI; EC 1.1.1.86) catalyzes the second common step in branched-chain amino acid biosynthesis. The catalyzed process consists of two steps, the first of which is an alkyl migration from one carbon atom to its neighboring atom. The likely transition state is a cyclopropane derivative, thus a new series of cyclopropanecarbonyl thiourea derivatives were designed and synthesized involving a one-pot phase transfer catalyzed reaction. Rice KARI inhibitory activity of these compounds were evaluated and the 5-butyl substituted (3e) and 3-pyridinyl substituted (3n) compounds reached 100% at 100 microg x mL(- 1). Structure-activity relationship shows that longer chain derivatives had higher KARI inhibitory activity. Meanwhile substitution of the 4-position of the benzene ring had higher KARI inhibitory activity than that of the 2 and 3-position. Auto-Dock was used to predict the binding mode of 3n. This was done by analyzing the interaction of compound 3n with the active sites of the available spinach KARI. This was in accord with the results analyzed by the frontier molecular orbital theory.

Effect of lipiodol and methylene blue on the thoracoscopic preoperative positioning.

The aim of this study was to compare and analyze the site-specific accuracy of mixture of lipiodol and methylene blue (MLM) (0.6 ml, 1:5) and pure methylene blue (0.5 ml) on the rabbit lungs. In this study, CT-guided percutaneous injection of MLM and methylene blue. Compare the staining degree by biopsy of lung tissue. Use 4 points system to evaluate the site-specific accuracy at 6h and 24 h after injection. For MLM, evaluate its radiopacity by radiation. When evaluate the positioning, 2 points mean acceptable, 3 points mean excellent. The results indicated that the staining range of MLM is obvious less than that of methylene blue (0.6 vs. 1.0 cm, P<0.01), but the staining capacity of MLM is higher than that of methylene blue (2.8 vs. 2.2, P = 0.01). About the staining abilities which are evaluated as excellent, MLM group accounts for 81%, methylene blue group accounts for 38% (P = 0.011). About the radiopacity which are evaluated as acceptable or excellent, MLM group accounts for 62%. With good direct vision, the suitable positioning rate of MLM can be 100%, which is better than that of methylene blue. In conclusion, percutaneous injection of MLM can be used to lung positioning. The result shows that use MLM is better than only using methylene blue. But it is necessary to do the investigation in human beings in order to confirm the feasibility of its clinical application.

Propagation characteristics of surface acoustic waves in single-electron transport devices and the electrical measurement.

We focused on investigating the propagation characteristics of surface acoustic waves (SAWs) in SAW-based single-electron-transport (SAW/SET) devices. SAW/SET devices operating in the gigahertz frequency range were fabricated on a GaAs/Al(x)Ga(1-x)As heterostructure. The transmittance and reflection performances of SAW/SET devices were obtained via the electrical measurement. Modeling based on coupling-of-modes theory was introduced to analyze SAW/ SET devices. Based on this model, many second-order effects such as propagation loss and the mechanical and electrical loadings caused by electrode perturbation of the surface were taken into account. Multiple-transit reflections of SAWs were also contained in the calculation. The calculated transmittance and reflection performances were in good agreement with the measured data. Furthermore, we proposed four interference types which could satisfactorily explain the periodic oscillations presented in the acoustoelectric current versus frequency characteristics.

Synthesis and antifungal activities of new pyrazole derivatives via 1,3-dipolar cycloaddition reaction.

A series of cycloadducts--pyrazoles via 1,3-dipolar cycloaddition reactions of generated nitrilimines with N-(4-chloro-2-fluorophenyl)maleimide were described. The novel compounds synthesized were characterized by (1)H NMR, MS, and elemental analysis. The fungicidal tests showed that most of the title compounds exhibit significant fungicidal activities against Corynespora cassiicola.

Synthesis, antifungal activities and 3D-QSAR study of N-(5-substituted-1,3,4-thiadiazol-2-yl)cyclopropanecarboxamides.

A series of cyclopropanecarboxamide were prepared and tested for antifungal activity in vivo. The preliminary bioassays indicated that some compounds are comparable to the commercial fungicides. To further explore the comprehensive structure-activity relationship on the basis of fungicidal activity data, comparative molecular field analysis (CoMFA) was performed, and a statistically reliable model with good predictive power (r(2)=0.8, q(2)=0.516) was achieved. Based on the CoMFA, compound 7p was designed and synthesized, which was found to display a good antifungal activity (79.38%) as 7g and 7h.

Synthesis of some N, n'-diacylhydrazine derivatives with radical-scavenging and antifungal activity.

A series of N,N'-diacylhydrazines were prepared and their structures were confirmed by 1H NMR, MS and FTICR-MS. They were tested radical-scavenging activity in vitro. The preliminary bioassays of title compounds showed that two compounds had excellent radical-scavenging activity comparable with vitamin C, while the activity is highly relative to the substituents. Surprisingly, several compounds also exhibit favorable fungicidal activities. To further explore the comprehensive structure-activity relationships about the fungicidal activity, a three-dimensional quantitative structure-activity relationship analysis using the method of comparative molecular field analysis was performed.