Switchable NaCl cages via a MWCNTs/Ni[Fe(CN)6]2 nanocomposite for high performance desalination

With the application of nanomaterials in seawater desalination technology increasing, the adjustable characteristics of carbon-based nanomaterials make it possible to use multiwalled carbon nanotube (MWCNT) materials in seawater desalination technology. In this study, Ni[Fe(CN)6]2 is loaded onto the inner wall of MWCNTs by the co-precipitation method to prepare MWCNTs with variable pore size, making it a switchable cage for NaCl. During the procedure, most of the Ni[Fe(CN)6]2 is transferred to the outer surface of the MWCNTs after adsorption, and NaCl is stored inside the MWCNTs (which have been proved by characterization); at the same time, Ni can improve the cell stability of Ni[Fe(CN)6]2. The effect of adsorbent reaction time and addition amount on the desalination performance of MWCNTs/Ni[Fe(CN)6]2 has been tested. According to the results, the best desalination performance of MWCNTs/Ni[Fe(CN)6]2 is 1354.6 mg g-1 when the reaction time is 0.5 h and the addition amount is 20 mg. After 3 cycles of adsorption and desorption, its desalting performance decreased to 242.3 mg g-1.

[Efficacy and safety of endovascular therapy after 24 h from ischemic stroke onset in patients with acute anterior circulation ischemic stroke]

Objective: To explore the effectiveness and safety of endovascular treatment (EVT) for patients with acute anterior circulation ischemic stroke with symptom onset exceeding 24 h. Methods: In this retrospective cohort study, data were extracted from patients who underwent endovascular treatment for acute anterior circulation ischemic stroke at the First Hospital of Jilin University from February 2019 to April 2022. A total of 569 patients were included, with a mean age of 63 (54-70) years. Among them, 398 (69.9%) were male. The patients were divided into two groups based on symptom onset time:>24 h group and≤24 h group. Propensity score matching (PSM) was used to match the patients in a 1︰1 ratio between the>24 h group and the≤24 h group. Logistic regression was used to evaluate the impact of symptom onset time on outcome events. Results: Before PSM, compared with≤24 h group, the>24 h group had a younger age [56 (48, 64) vs. 64 (55, 70), Z=-3. 60, P<0.001]; lower proportion of prior atrial fibrillation [1.8% (1/57) vs. 21.1% (108/512), χ2=12.39, P<0.001]; lower proportion of wake-up stroke [7.0% (4/57) vs. 27.7% (142/512), χ2=11.54, P<0.001]; lower baseline NIHSS score [11.0 (7.5, 14.0) vs. 13.0 (10.0, 16.0), Z=-3.22, P<0.001]; and a higher American Society of Interventional and Therapeutic Neuroradiology/Society of Interventional Radiology(ASITN/SIR) grading (P<0.001). After PSM, there were no significant differences in baseline characteristics between the two groups. There was no significant difference in the proportion of patients with a modified Rankin Scale (mRS) score≤2 at 90 days after surgery between the two groups (before matching: 42.0% vs. 40.4%, OR=0.745, 95%CI 0.407-1.362, P=0.339; after matching: 51.8% vs. 39.3%, OR=0.511, 95%CI 0.212-1.236, P=0.136). No significant differences were observed in the incidence of any safety outcomes between the>24 h group and the≤24 h group. Conclusion: For patients with acute anterior circulation ischemic stroke with symptom onset exceeding 24 h, EVT is feasible after strict radiological screening and has similar safety and effectiveness as for patients with symptom onset under 24 h.

A geopolymer membrane for application in a structural mechanics and energy storage difunctional supercapacitor

A structural mechanics and energy storage difunctional supercapacitor based on a geopolymer membrane injected with a 0.5 M Na2SO4 electrolyte and a pseudocapacitive electrode Mn7O13 is designed and assembled. The geopolymer membrane is prepared as a structural electrolyte with metakaolin and alkaline activator solution. The wide channels in the geopolymer matrix provide paths for ion movement. The Mn7O13 electrode is prepared by different hydrothermal treatments at different temperatures and times, and assembled with activated carbon and a geopolymer with different moduli to form a difunctional supercapacitor. The results show that the electrode sample annealed at 300 °C for 45 min after hydrothermal treatment at 160 °C for 24 h exhibits the best comprehensive performance. The specific capacitance of the electrode is 175.5 F g-1 (2392.6 F m-2) at 1 A g-1, and the specific capacitance of the difunctional structure supercapacitor assembled with a geopolymer with a modulus of 1.2 and cured for 28 days is 144.12 F g-1 (1960.0F m-2) at 1 A g-1 under 15 MPa.

[Diagnostic value of contrast-enhanced ultrasound in hepatic epithelioid hemangioendothelioma]

Objective: To investigate the features of contrast-enhanced ultrasound (CEUS) in hepatic epithelioid hemangioendothelioma (HEHE) in order to improve the preoperative diagnosis rate. Methods: CEUS images of 32 pathologically-proven cases of hepatic epithelioid hemangioendothelioma from January 2004 to August 2021 were collected. Lesions were analyzed to observe the features of enhancement mode, enhancement intensity, and distinct enhancement phases. Results: Among the 32 cases, one had a solitary lesion, 29 had multiple lesions, and two had diffuse-type lesions. Contrast-enhanced ultrasound revealed a total of 42 lesions in 32 cases. In terms of arterial phase enhancement, 18 lesions had overall enhancement, six lesions had uneven dendritic enhancement, 16 lesions had rim-like enhancement, and two lesions had just slight peripheral spot enhancement around the lesions. Among the three cases, there were multiple lesions that had overall enhancement and ring enhancement. In terms of the enhancement phase, 20 lesions showed "fast progression", 20 lesions showed "same progression", and two lesions showed "slow progression". During the late arterial or early portal venous phases with rapid washout, all lesions manifested as hypoechoic. With peaked enhanced intensity, 11 lesions had a lower enhancement intensity than the surrounding normal liver parenchyma; 11 lesions had the same enhancement degree as the surrounding normal liver parenchyma; and 20 lesions had a higher enhancement degree than the surrounding normal liver parenchyma. All 16 ring-enhancing lesions had marked hyperenhancement. In the typical enhancing lesions, four showed hyperenhancement, five showed low enhancement, and nine showed isoenhancement. In the dendrite-enhancing lesions, there were two isoenhancing and four hypoenhancing. Contrast-enhanced ultrasound delineated the boundaries of all lesions more clearly than two-dimensional ultrasound. Conclusion: Contrast-enhanced ultrasound has certain value in the diagnosis of hepatic epithelioid hemangioendothelioma.

Low-dimensional high entropy oxide (FeCoCrMnNi)3O4 for supercapacitor applications

Previous studies have found that high entropy oxides can be used as electrode materials for supercapacitors. However, there is still the problem of their low energy density. We tried to increase the energy density while increasing the specific capacitance of high entropy oxides from the potential window. Transition metal elements Fe, Co, Cr, Mn and Ni were selected for their electrochemical activity, and high entropy oxides were prepared by a sol-gel method under different calcination temperatures. The calcination temperature affects the structural morphology and crystallinity of the high entropy oxides and thus also affects the electrochemical performance. The spinel-phase (FeCoCrMnNi)₃O₄ with a high specific surface area of 63.1 m² g^-1 was prepared at a low calcination temperature of 450 °C. The specific capacitance is 332.2 F g^-1 at a current density of 0.3 A g^-1 in 1 M KOH electrolyte with a wide potential window of (-1, 0.6). An improved energy density of 103.8 W h kg^-1 is reached via the designed microstructure of the high entropy oxide electrode.

Flow Electrode Capacitive Deionization System with Simultaneous Desalting of Na+ and Gathering of Na. Langmuir 2022;38:15740-15746. [PMID: 36493336 DOI: 10.1021/acs.langmuir.2c02628] [Citation(s) in RCA: 0] [Impact Index Per Article: 0]

Oceans contain many freshwater resources and metal elements that people need, so the rational development of marine resources can solve the two major problems of shortage of freshwater resources and metal elements for people. To solve these two challenges, a system was designed to obtain freshwater resources and metallic elements simultaneously. An ion enrichment module was added to the conventional flow capacitor deionization system to collect metal elements while the seawater was deionized. A flowing electrode allows the metal elements to enter the flowing electrode through the desalination ability. It transports the metal elements to the enrichment module through the fluidity of the fluid while reducing the ion concentration at the flowing electrode, thus reducing the effect caused by the rejection of the same ion and collecting and enriching the metal elements. We purchased activated carbon to test the feasibility of the system with different mass fractions of activated carbon suspensions. The results showed that the elemental enrichment capacity of the system increased from 12.291 to 14.795 mg, and the enrichment rate increased from 13.536 to 16.294 mg cm^-2 h^-1 as the mass fraction of activated carbon increased. Thus, the system accomplished the goals of desalination and metal collection simultaneously.

Deep Learning for Approaching Hepatocellular Carcinoma Ultrasound Screening Dilemma: Identification of α-Fetoprotein-Negative Hepatocellular Carcinoma From Focal Liver Lesion Found in High-Risk Patients

Background

First-line surveillance on hepatitis B virus (HBV)-infected populations with B-mode ultrasound is relatively limited to identifying hepatocellular carcinoma (HCC) without elevated α-fetoprotein (AFP). To improve the present HCC surveillance strategy, the state of the art of artificial intelligence (AI), a deep learning (DL) approach, is proposed to assist in the diagnosis of a focal liver lesion (FLL) in HBV-infected liver background.

Methods

Our proposed deep learning model was based on B-mode ultrasound images of surgery that proved 209 HCC and 198 focal nodular hyperplasia (FNH) cases with 413 lesions. The model cohort and test cohort were set at a ratio of 3:1, in which the test cohort was composed of AFP-negative HBV-infected cases. Four additional deep learning models (MobileNet, Resnet50, DenseNet121, and InceptionV3) were also constructed as comparative baselines. To evaluate the models in terms of diagnostic power, sensitivity, specificity, accuracy, confusion matrix, F1-score, and area under the receiver operating characteristic curve (AUC) were calculated in the test cohort.

Results

The AUC of our model, Xception, achieved 93.68% in the test cohort, superior to other baselines (89.06%, 85.67%, 83.94%, and 78.13% respectively for MobileNet, Resnet50, DenseNet121, and InceptionV3). In terms of diagnostic power, our model showed sensitivity, specificity, accuracy, and F1-score of 96.08%, 76.92%, 86.41%, and 87.50%, respectively, and PPV, NPV, FPR, and FNR calculated from the confusion matrix were respectively 80.33%, 95.24%, 23.08%, and 3.92% in identifying AFP-negative HCC from HBV-infected FLL cases. Satisfactory robustness of our proposed model was shown based on 5-fold cross-validation performed among the models above.

Conclusions

Our DL approach has great potential to assist B-mode ultrasound in identifying AFP-negative HCC from FLL found in surveillance of HBV-infected patients.

Stackelberg-Nash Equilibrium and Perfect Competition in the Solow-Uzawa Growth Model

This study introduces Stackelberg-Nash equilibrium to neoclassical growth theory. It attempts to make neoclassical economic growth theory more robust in modelling the complexity of market structures. The model is constructed within the framework of the Solow-Uzawa two-sector model. The economy is composed of two sectors. The final goods sector is the same as in the Solow one-sector growth model which is characterized by perfect competition. The consumer goods sector is the same as the consumer goods sector in the Uzawa model but is characterized by Stackelberg duopoly. We model household behavior with Zhang’s concept of disposable income and utility. The model endogenously determines profits of duopoly which are equally distributed among the homogeneous population. We build the model and then identify the existence of an equilibrium point through simulation. We conduct comparative static analyses of some parameters. We also compare the economic performance of the traditional Uzawa model and the model with the Stackelberg-Nash equilibrium. We conclude that the imperfect competition increases national output, national wealth, and utility level in comparison to perfect competition. 

Theoretical investigation of the low lying electronic states of MgGa

In this work, we investigate the low-lying electronic states correlated to the first and the second dissociation channels of MgGa molecule, neglecting and including the spin-orbit coupling effect. High-level ab initio calculations have been performed by using the icMRCI + Q method. Potential energy curves, spectroscopic constants, electron configurations and dipole moments are derived and discussed. Molecular structures of several magnesium-group 13 diatomics have been probed and analyzed. Information associated with transition dipole moments, Franck-Condon factors, vibrational branching ratios and radiative lifetimes between the Ω states are also well characterized. It is anticipated this work will provide some inspiration for further studies on MgGa.

[Application of diffusion-weighted magnetic resonance imaging in evaluating the efficacy of radiotherapy and chemotherapy for esophageal cancer]

This study was a prospective single arm trial conducted in Zhejiang Jinhua Guangfu hospital from February 2018 to June 2020. A total of 39 patients (32 males and 7 females) with esophageal cancer, aged from 44 to 82 (69±9) years were enrolled. Diffusion weighted magnetic resonance imaging(MR-DWI) was implemented to evaluate the changes of apparent diffusion coefficient(ADC) value before and after chemoradiotherapy. The results showed that the ADC value after chemoradiotherapy was higher than that before treatment[(2.03±0.42)×10⁻³ mm ²/s vs (1.60±0.28)×10⁻³ mm²/s], and there was a positive correlation between the increase of ADC value and the prognosis of patients.

Cournot-Nash Equilibrium and Perfect Competition in the Solow-Uzawa Growth Model

The purpose of this study is to contribute to economic growth theory by introducing Cournot competition into the Solow-Uzawa neoclassical growth model with Zhang’s concept of disposable income and utility function. The Solow-Uzawa two-sector growth model deals with economic growth with two sectors with all the markets perfectly competitive. The final goods sector in this study is the same as that in the Solow model with perfect competition. The consumer goods sector is composed of two firms and characterized by Cournot competition. All the input factors are traded in perfectly competitive markets. The duopoly’s product is solely consumed by consumers. Perfectly competitive firms earn zero profit, while duopolists earn positive profits. This study assumes that the population shares the profits equally. First, we built the dynamic model. Afterward, we found a computational procedure to describe the time-dependent path of the economy and conducted comparative dynamic analyses of some parameters. Finally, we compared the economic performances of the model with Cournot competition and the perfectly competitive model.

[A multi-center retrospective study of perioperative chemotherapy for gastric cancer based on real-world data]

Objective: To explore the effect of perioperative chemotherapy on the prognosis of gastric cancer patients under real-world condition. Methods: A retrospective cohort study was carried out. Real world data of gastric cancer patients receiving perioperative chemotherapy and surgery + adjuvant chemotherapy in 33 domestic hospitals from January 1, 2014 to January 31, 2016 were collected. Inclusion criteria: (1) gastric adenocarcinoma was confirmed by histopathology, and clinical stage was cT2-4aN0-3M0 (AJCC 8th edition); (2) D2 radical gastric cancer surgery was performed; (3) at least one cycle of neoadjuvant chemotherapy (NAC) was completed; (4) at least 4 cycles of adjuvant chemotherapy (AC) [SOX (S-1+oxaliplatin) or CapeOX (capecitabine + oxaliplatin)] were completed. Exclusion criteria: (1) complicated with other malignant tumors; (2) radiotherapy received; (3) patients with incomplete data. The enrolled patients who received neoadjuvant chemotherapy and adjuvant chemotherapy were included in the perioperative chemotherapy group, and those who received only postoperative adjuvant chemotherapy were included in the surgery + adjuvant chemotherapy group. Propensity score matching (PSM) method was used to control selection bias. The primary outcome were overall survival (OS) and progression-free survival (PFS) after PSM. OS was defined as the time from the first neoadjuvant chemotherapy (operation + adjuvant chemotherapy group: from the date of operation) to the last effective follow-up or death. PFS was defined as the time from the first neoadjuvant chemotherapy (operation + adjuvant chemotherapy group: from the date of operation) to the first imaging diagnosis of tumor progression or death. The Kaplan-Meier method was used to estimate the survival rate, and the Cox proportional hazards model was used to evaluate the independent effect of perioperative chemo therapy on OS and PFS. Results: 2 045 cases were included, including 1 293 cases in the surgery+adjuvant chemotherapy group and 752 cases in the perioperative chemotherapy group. After PSM, 492 pairs were included in the analysis. There were no statistically significant differences in gender, age, body mass index, tumor stage before treatment, and tumor location between the two groups (all P>0.05). Compared with the surgery + adjuvant chemotherapy group, patients in the perioperative chemotherapy group had higher proportion of total gastrectomy (χ(2)=40.526, P<0.001), smaller maximum tumor diameter (t=3.969, P<0.001), less number of metastatic lymph nodes (t=1.343, P<0.001), lower ratio of vessel invasion (χ(2)=11.897, P=0.001) and nerve invasion (χ(2)=12.338, P<0.001). In the perioperative chemotherapy group and surgery + adjuvant chemotherapy group, 24 cases (4.9%) and 17 cases (3.4%) developed postoperative complications, respectively, and no significant difference was found between two groups (χ(2)=0.815, P=0.367). The median OS of the perioperative chemotherapy group was longer than that of the surgery + adjuvant chemotherapy group (65 months vs. 45 months, HR: 0.74, 95% CI: 0.62-0.89, P=0.001); the median PFS of the perioperative chemotherapy group was also longer than that of the surgery+adjuvant chemotherapy group (56 months vs. 36 months, HR=0.72, 95% CI:0.61-0.85, P<0.001). The forest plot results of subgroup analysis showed that both men and women could benefit from perioperative chemotherapy (all P<0.05); patients over 45 years of age (P<0.05) and with normal body mass (P<0.01) could benefit significantly; patients with cTNM stage II and III presented a trend of benefit or could benefit significantly (P<0.05); patients with signet ring cell carcinoma benefited little (P>0.05); tumors in the gastric body and gastric antrum benefited more significantly (P<0.05). Conclusion: Perioperative chemotherapy can improve the prognosis of gastric cancer patients.

Conhecimento Global e Riqueza com Capital Humano Nacional e Comércio Livre

Este documento trata de questões de crescimento económico global com riqueza privada endógena, capital humano nacional, e conhecimento global. Construímos um modelo de crescimento multinacional entre a acumulação de riqueza, a mudança do capital humano e o crescimento do conhecimento, integrando os mecanismos económicos básicos em algumas teorias. O modelo é enquadrado na teoria do crescimento neoclássico. A acumulação de capital humano baseia-se no modelo biossectormal Uzawa-Lucas. O padrão comercial é determinado como no modelo comercial de Oniki-Uzawa. O crescimento do conhecimento é influenciado pela nova teoria do crescimento. O comportamento das famílias é modelado usando o conceito de Zhang de rendimento disponível e função de utilidade. A dinâmica da economia mundial do país J é descrita por 2J+1 equações diferenciais de riqueza, capital humano e conhecimento. Simulamos o movimento da economia global com base em três economias. Também realizamos uma análise dinâmica comparativa para mostrar como as mudanças nas características nacionais, tais como propensão para poupar, propensão para receber educação, eficiência na aplicação do capital humano e criatividade, mudam os caminhos dinâmicos do desenvolvimento económico global e doméstico.

Application of double layered end-to-end anastomosis with continuous manual suture for completing digestive tract reconstruction in totally laparoscopic distal gastrectomy

Background

We retrospectively reviewed and consecutively collected the clinical data of distal gastric cancer patients who received surgical treatment, and we discuss the safety and feasibility of double layered end-to-end anastomosis with continuous manual suture to complete digestive tract reconstruction in totally laparoscopic distal gastrectomy.

Methods

We reviewed the clinical data of 41 patients with distal gastric cancer from the gastroenterology department of the Second Affiliated Hospital of Dalian Medical University, from September 2018 to August 2019, who underwent totally laparoscopic distal gastrectomy. During the operation, the method of double layered end-to-end anastomosis with continuous manual suture was used for Billroth type I anastomosis to complete digestive tract reconstruction. All patients have been given a follow-up visit and gastroscopy three months after the operation. The peri-operative clinical information and postoperative follow-up information were collected for analysis, and the clinical application value was evaluated.

Results

General information: male(n = 27), female(n = 14), age = 65.02(SD 9.94) years, and BMI = 23.52(SD 2.56) kg/m², Tumor location: antrum(32,78.0%), angle (6,14.6%), and body (3,7.3%). Clinical stage: I (27, 65.9%), II (7, 17.1%), and III (7, 17.1%). Operative information: operation time = 154.51(SD 33.37) min, anastomosis time = 26.88(SD 5.11) min; intraoperative bleeding = 66.34(SD 48.81) ml; first postoperative ambulation Median = 1(IQR 0) d, first postoperative flatus Median = 3(IQR 2) d, first postoperative diet Median = 3(IQR 1) d, postoperative hospital stay Median = 7(IQR 2) d, and total hospitalization cost = 10,935.00(SD 2205.72)USD. Differentiation degree: high and high-moderate (3,7.32%), moderate and poor-moderate (24, 58.54%), poor differentiation (14, 34.15%), dissected lymph nodes Median = 31(IQR 17), and positive lymph nodes Median = 0(IQR 1). Pathological stage: IA (20, 48.78%), IB (3, 7.32%), IIA (4, 9.76%), IIB (5, 12.20%), IIIA (1, 2.44%), IIIB (3, 7.32%), and IIIC (5, 12.20%). Complications (n = 4): lung infection (1, 2.44%), anastomotic leakage (1, 2.44%), and gastroparesis (2, 4.88%).

Conclusion

It is safe and feasible in clinical treatment to apply the method of double layered end-to-end anastomosis with continuous manual suture to complete digestive tract reconstruction in totally laparoscopic distal gastrectomy.

An Integration of Neoclassical Growth Theory and Economic Structural Change with Monopolistic Competition Theory

Wealth accumulation is a deterministic factor mechanism of national economic growth. Neoclassical growth theory is basically concerned with capital and wealth accumulation in perfectly competitive market. Global markets are characterized by a great variety of markets. Nevertheless, there only a few rigorous models of wealth accumulation with other types of markets within neoclassical growth framework. This study attempts to contribute literature of economic growth by introducing monopolistic competition and monopoly into neoclassical growth theory. The model is based on a few well-established economic theories. The model is constructed within framework of the Solow-Uzawa two-sector neoclassical growth model. The description of to monopolistic competition is influenced by the Dixit-Stiglitz model of monopolistic competition. The modelling of monopoly is based on monopoly theory. We model behavior of the household with Zhang’s utility function and concepts of current income and disposable income. The unique contribution of this research is to integrate these theories in a comprehensive framework. We construct the basic model and then analyze properties of the model. The existence of a unique equilibrium point is identified by simulation. The effects of changes in some parameters comparative static analyses in some parameters.

Banking and Money in an Extended Solow-Uzawa’s Neoclassical Growth Model

This study deals with interactions between economic growth and structural change with banking. The study is influenced by the growth model of money and banking by Chang et al. (2007). It deviates from Chang et al.’ model with regard to the monetary authority behavior, economic structure, and modeling behavior of household. The model deals with dynamic interactions between money, banking, economic structural change and growth in a perfectly competitive economy. The economic system consists of one capital goods sector, one consumer goods sector, and one banking sector. The two goods sectors are based on the Solow-Uzawa growth model. The motion is described by a set of differential equations. For illustration, we simulate the motion of the economic system. We identify the existence of a stable equilibrium point. We carry out comparative dynamic analysis. The comparative analyses provide some insights into the complexity of economic growth with banking.

[Implementing and evaluating the online course system of orthodontic education]

A new teaching mode with the combination of online teaching and flipped class was designed and implemented in the Stomatological College of Nanjing Medical University based on the National Online Open Courses, the Virtual Interactive Network Teaching Platform and the E-learning Network Teaching Platform. The new online course system of orthodontic education was constructed with several components including the process and outcome assessments, the professional literature and knowledge summary reports and the virtual interactive online training. With the informative and convenient online teaching resources and modes, students' comprehensive abilities of independent learning were improved.

[The study of the association between lung cancer screening and smoking behavior change]

The smoking cessation rate of 1 314 people at high risk of lung cancer in the area of lung cancer screening and early diagnosis and early treatment in Sichuan Province increased from 22.37% at baseline to 41.78% after screening (χ²=227.97, P<0.001), and the smoking amount of persistent smokers decreased from 20 cigarettes per day to 15 cigarettes per day (t=11.76, P<0.001). Those with positive results in lung cancer screening were more likely to quit smoking or continue to quit smoking. Male, younger age or lower education level would increase the risk of continuous smoking or relapse (P<0.05).

A neoclassical growth model with endogenous birth and mortality rates

This study examines dynamic interdependence between different socio-cultural groups? birth rates, mortality rates, populations, wealth accumulation, and the allocation of time between work, leisure, and childcare. It emphasises the role of changes in human capital, technology, and preferences on birth and mortality rates and time allocations. The economic mechanism of wealth and income distribution is based on the Walrasian general equilibrium theory, and wealth accumulation is based on the Solow growth model. The paper uses a utility function proposed by Zhang (2015) to describe the behaviour of households. It also models group and gender differences in human capital, the propensity to have children, the propensity to use leisure time, and the efficiency of childcare. The paper uses differential equations to describe the dynamics of group differences in wealth, income, birth rates, mortality rates, and populations. I simulate a model to show the motion of the system and identify the existence of an equilibrium point. I also examine the effects on the dynamics of the economic system of changes in the propensity to have children and the propensity to save, and in gender differences in the propensity to use leisure, in human capital, and in emotional involvement in childcare.

Ramsey Taxation in the Solow-Uzawa Growth Model with Public Goods

This paper examines issues related to optimal taxation similar to those addressed by Ramsey in his celebrated 1927 paper. Rather than determining taxes on commodities with given revenue to minimize the decrement of utility may be minimum in the Ramsey approach, this model determines optimal taxation to maximize utility with revenue as endogenous variable. We analyze optimal taxation in neoclassical growth theory. We introduce a public sector to the Solow-Uzawa neoclassical growth model. The economy is composed of the public, capital goods and consumer goods sectors. Public goods enter into the utility function. The public sector is financially supported by the government’s revenue from taxing consumption of capital goods and consumer goods. We derive the optimal taxation rule and construct the dynamics of the national economy. The model describes nonlinear dynamic interactions among national and sectoral growth, economic structural change, wealth/capital accumulation, and optimal tax rates in perfect competitive markets with the government intervention. We carry out comparative analysis to analyze effects of changes in some parameters on the tax rates and other economic variables.

[Radiomics nomogram of MR: a prediction of cervical lymph node metastasis in laryngeal cancer]

Objective: To establish and validate a radiomics nomogram based on MR for predicting cervical lymph node metastasis in laryngeal cancer. Methods: One hundred and seventeen patients with laryngeal cancer who underwent MR examinations and received open surgery and neck dissection between January 2016 and December 2019 were included in this study. All patients were randomly divided into a training cohort (n=89) and test cohort (n=28) using computer-generated random numbers. Clinical characteristics and MR were collected. Radiological features were extracted from the MR images. Enhanced T1 and T2WI were selected for radiomics analysis, and the volume of interest was manually segmented from the Huiyihuiying radiomics cloud platform. The variance analysis (ANOVA) and the least absolute shrinkage and selection operator (LASSO) algorithm were used to reduce the dimensionality of the radiomics features in the training cohort. Then, a radiomic signature was established. The clinical risk factors were screened by using ANOVA and multivariate logistic regression. A nomogram was generated using clinical risk factors and the radiomic signature. The calibration curve and receiver operator characteristic (ROC) curve were used to confirm the nomogram's performance in the training and test sets. The clinical usefulness of the nomogram was evaluated by decision curve analysis (DCA). Furthermore, a testing cohort was used to validate the model. Results: The radiomics signature consisted of 21 features, and the nomogram model included the radiomics signature and the MR-reported lymph node status. The model showed good calibration and discrimination. The model yielded areas under the ROC curve (AUC) in the training cohort, specificity, and sensitivity of 0.930, 0.930 and 0.875. In the test cohort, the model yielded AUC, specificity and sensitivity of 0.883, 0.889 and 0.800. DCA indicated that the nomogram model was clinically useful. Conclusion: The MR-based radiomics nomogram model may be used to predict cervical lymph node metastasis of laryngeal cancer preoperatively. MR-based radiomics could serve as a potential tool to help clinicians make an optimal clinical decision.

Economic Development and International and Interregional Tourism

Subject and purpose of work: Tourism was the fastest growing industry until the outbreak of Covid-2019. Nevertheless, there are a few studies on how the industry interacts with the rest of economies within a comprehensive analytical framework. The main concern of this study is how international and interregional tourism interacts with national economic development and economic structural change. Tourism and economic growth are investigated in a multi-regional small open economy which is perfectly competitive.

Materials and methods: National economy consists of multiple regions and each region has three sectors: industry, service, and housing. Production side is the same as in the neoclassical growth theory. Households move freely between regions, equalizing utility level between regions by selecting housing, goods, tourism, and saving. A region’s amenity is endogenously related to the region’s population.

Results: We explicitly solve the dynamics of the multi-regional economy. The system has a unique stable equilibrium point.

Conclusions: We simulate the motion of the model and examine the effects of changes in the rate of interest, foreigners’ preference for visiting a region, a region ‘s total productivity of the service sector, domestic consumers’ preference for visiting a region, as well as the propensity to save, the propensity to consume regional services and housing.

Economic Growth with Social Status, Spirit of Capitalism, and Conspicuous Consumption

The purpose of this study is to introduce social status, conspicuous consumption, and spirit of capitalism into neoclassical growth model. This paper studies a dynamic interdependence between economic growth, economic structural change, income and wealth distribution, social status, conspicuous consumption, and spirit of capitalism in a small-open economy. We build a heterogeneous-households growth model with endogenous wealth accumulation and social status. The dynamics of J-households economy is described by J differential equations. We simulate the motion of the model with three groups of households. We carry out comparative dynamic analysis with regard to some parameters.

Theoretical study of the low-lying electronic states, including the spin-orbit interactions, of the sulfur monochloride cation

High-level ab initio computations have been performed on the experimentally unknown species SCl⁺. The low-lying Λ-S electronic states correlated to the first and the second dissociation channels as well as their corresponding Ω states have been investigated by the icMRCI+Q methodology employing basis sets up to quintuple-ζ quality. Information about potential energy curves, electron configurations, spectroscopic constants, dipole moments and transition properties are derived and discussed. The results for SCl⁺ represent an improvement over our previous theoretical descriptions for the ground state. In addition, several low-lying excited states that have not been accessed experimentally and theoretically are also been well characterized in this work. The accuracy of our predictions for SCl⁺ are verified by comparisons of spectroscopic constants and vibrational levels between our accompany SCl computations and those reported in literatures for the neutral species. The feasibility of performing laser cooling of SCl⁺ has also been discussed and the photoelectron spectrum of SCl⁺(X³Σ^-) + e ← SCl(X²Π) is simulated.

GLOBAL DEVELOPMENT, TRADE, HUMAN CAPITAL, AND BUSINESS CYCLES

This paper generalizes the multi-country growth model with capital accumulation, human capital accumulation, economic structure and international trade by Zhang (2014) by making all the time-independent parameters in Zhang’s model as time-dependent parameters. Each national economy consists of one tradable, one non-tradable and one education sector. National economies are different in propensities to save, to obtain education and to consume, and in learning abilities. The model integrates the Solow growth model, the Uzawa two-sector growth model, the Uzawa-Lucas two-sector growth model, and the Oniki–Uzawa trade model within a comprehensive framework. Human capital accumulation is through education in the Uzawa-Lucas model, Arrow’s learning by producing, and Zhang’s learning by consuming (creative learning). The behavior of the household is described with an alternative approach to household behavior. We simulated the model to demonstrate existence of equilibrium points, motion of the dynamic system, and oscillations due to different exogenous shocks.

Characterization of the low-lying electronic states of tin monohydride cation including the spin-orbit coupling effect: A theoretical perspective

High-level ab initio computations have been performed on SnH⁺. The potential energy curves and spectroscopic constants of the low-lying Λ-S electronic states, as well as their associated Ω states, are derived at the icMRCI + Q level employing basis sets of quintuple-ζ quality. The transition dipole moments, Einstein coefficients, radiative lifetimes and Franck-Condon factors of three spin-forbidden transition bands ( [Formula: see text] , [Formula: see text] and [Formula: see text] ) are determined. Comparisons between our predictions and available experimental results indicate reasonable agreement. The spin-orbit coupling effect has been proved to affect these low-lying electronic states significantly.

Ab initio investigation on the low-lying electronic states of magnesium antimonide

The twelve Λ-S electronic states of the first four dissociation limits of the MgSb molecule have been examined at the icMRCI+Q level employing basis sets of quintuple-ζ quality. The potential energy curves, vibrational levels and spectroscopic constants of the species have been investigated. The permanent dipole moments of the interested states are derived, and the transition dipole moments, Einstein emission coefficients, radiation lifetimes and Franck-Condon factors between selected states are also determined. Four Λ-S states of the first two dissociation limits split into seven Ω states under the effect of spin-orbit coupling. Characterizations of the MgSb low-lying Ω states are performed for the first time. In addition, the results and relevant data provided in this work on MgSb are compared with the antimony-IIA group and magnesium-VA group diatomic species. It is anticipated that this work will shed some light on further investigations of MgSb and other antimony-IIA group systems.

Monopolies and perfect competition in Solow–Uzawa’s general equilibrium growth model

The purpose of this study is to introduce monopolies to neoclassical growth theory. This unique contribution attempts to make neoclassical economic growth theory more realistic in modelling the complexity of economic growth and development with different types of market structures. This study is based on a few well-established economic theories in the literature of economics. We frame the model on basis of the Solow–Uzawa two-sector growth model. The modelling of monopoly is based on well-developed monopoly theory. We model behavior of the household with Zhang’s concept of disposable income and utility function. The model endogenously determines profits of monopolies which are equally distributed among the homogeneous population. We build the model and then identify the existence of an equilibrium point by simulation. We conduct comparative static analyses in some parameters.