Development of a simple nomogram to estimate risk for intraoperative complications before partial nephrectomy based on the Mayo Adhesive Probability score combined with the RENAL nephrometry score

Xiaojun Tan,Dachun Jin,Jian Hu,Weili Zhang,Yu Zhou,Yunxiang Li,Yuanfeng Zhang,Ji Wu 대한비뇨의학회 2021 Investigative and Clinical Urology Vol.62 No.4

Purpose: This study aimed to develop a simple nomogram based on the Mayo Adhesive Probability (MAP) score combined with the RENAL nephrometry score (RNS) to predict intraoperative complications before partial nephrectomy (PN) in Asian populations. Materials and Methods: This study retrospectively collected patients undergoing PN at three medical centers. Each component of the MAP score and the RNS (6 variables) was evaluated to assess its association with intraoperative complications by multivariable logistic regression with backward elimination. Results: A total of 46 cases (7.2%) with intraoperative complications were identified among 637 patients. After backward elimination, three variables, including tumor diameter (4–7 cm vs. ≤4 cm: odds ratio [OR], 4.339; 95% confidence interval [CI], 1.943–9,692; ≥7 cm vs. ≤4 cm: OR, 8.434; 95% CI, 1.225–58.090), nearness to the collecting system (4–7 mm vs. ≥7 mm: OR, 2.988; 95% CI, 1.293–6.907; ≤4 mm vs. ≥7 mm: OR, 21.394; 95% CI, 6.122–74.756), and perirenal fat stranding type (type 1 vs. no stranding: OR, 3.119; 95% CI, 1.079–9.017; type 2 vs. no stranding: OR, 18.722; 95% CI, 6.757–51.868), were retained. The predictive power (measured by area under the curve [AUC]) of the nomogram was observed to be superior to the RNS or MAP score alone (RNS: 0.686, MAP score: 0.729, the nomogram: 0.837), but comparable to their combination (0.813). Conclusions: The simple nomogram contains fewer components than the combination of the RNS and MAP scores yet demonstrates equivalent predictive power for intraoperative complications.

Theoretical Studies on the Alkylidene Silylenoid H2C = SiLiF and Its Insertion Reaction with R-H (R = F, OH, NH2)

Xiaojun Tan,Weihua Wang,Ping Li,Qingyan Li,Lei Cheng,Shufen Wang,Weiwang Cai,Jinping Xing 대한화학회 2010 Bulletin of the Korean Chemical Society Vol.31 No.5

The geometries and isomerization of the alkylidene silylenoid H2C = SiLiF as well as its insertion reactions with R-H (R = F, OH, NH2) have been systematically investigated at the B3LYP/6-311+G* level of theory. The potential barriers of the three insertion reactions are 97.5, 103.3, and 126.1 kJ/mol, respectively. Here, all the mechanisms of the three reactions are identical to each other, i.e., an intermediate has been formed first during the insertion reaction. Then, the intermediate could dissociate into the substituted silylene (H2C = SiHR) and LiF with a barrier corresponding to their respective dissociation energies. Correspondingly, the reaction energies for the three reactions are ‒36.4, ‒24.3, and 3.7kJ/mol, respectively. Compared with the insertion reaction of H2C = Si: and R-H (R = F, OH and NH2), the introduction of LiF makes the insertion reaction occur more easily. Furthermore, the effects of halogen (F, Cl, Br) substitution and inorganic salts employed on the reaction activity have also been discussed. As a result, the relative reactivity among the three insertion reactions should be as follows: H-F > H-OH > H-NH2.

Theoretical Studies on the Alkylidene Silylenoid H₂C = SiLiF and Its Insertion Reaction with R-H (R = F, OH, NH₂)

Tan, Xiaojun,Wang, Weihua,Li, Ping,Li, Qingyan,Cheng, Lei,Wang, Shufen,Cai, Weiwang,Xing, Jinping Korean Chemical Society 2010 Bulletin of the Korean Chemical Society Vol.31 No.5

The geometries and isomerization of the alkylidene silylenoid $H_2C$ = SiLiF as well as its insertion reactions with R-H (R = F, OH, $NH_2$) have been systematically investigated at the B3LYP/6-311+$G^*$ level of theory. The potential barriers of the three insertion reactions are 97.5, 103.3, and 126.1 kJ/mol, respectively. Here, all the mechanisms of the three reactions are identical to each other, i.e., an intermediate has been formed first during the insertion reaction. Then, the intermediate could dissociate into the substituted silylene ($H_2C$ = SiHR) and LiF with a barrier corresponding to their respective dissociation energies. Correspondingly, the reaction energies for the three reactions are -36.4, -24.3, and 3.7 kJ/mol, respectively. Compared with the insertion reaction of $H_2C$ = Si: and R-H (R = F, OH and $NH_2$), the introduction of LiF makes the insertion reaction occur more easily. Furthermore, the effects of halogen (F, Cl, Br) substitution and inorganic salts employed on the reaction activity have also been discussed. As a result, the relative reactivity among the three insertion reactions should be as follows: H-F > H-OH > H-$NH_2$.

Theoretical Study on the Mechanism of the Addition Reaction between Cyclopropenylidene and Formaldehyde

Xiaojun Tan,Zhen Li,Qiao Sun,Ping Li,Weihua Wang 대한화학회 2012 Bulletin of the Korean Chemical Society Vol.33 No.6

The reaction mechanism between cyclopropenylidene and formaldehyde has been systematically investigated employing the MP2/6-311+G* level of theory to better understand the cyclopropenylidene reactivity with carbonyl compound. Geometry optimization, vibrational analysis, and energy property for the involved stationary points on the potential energy surface have been calculated. Energies of all the species are further corrected by the CCSD(T)/6-311+G* single-point calculations. It was found that one important reaction intermediate (INTa) has been located firstly via a transition state (TSa). After that, the common intermediate (INTb) for the two pathways (1) and (2) has been formed via TSb. At last, two different products possessing three- and four-membered ring characters have been obtained through two possible reaction pathways. In the reaction pathway (1), a three-membered ring alkyne compound has been obtained. As for the reaction pathway (2), it is the formation of the four-membered ring conjugated diene compound. The energy barrier of the ratedetermining step of pathway (1) is lower than that of the pathway (2), and the ultima product of pathway (2) is more stable than that of the pathway (1).

Theoretical Study on the Reaction Mechanism of Azacyclopropenylidene with Epoxypropane: An Insertion Process

Xiaojun Tan,Weihua Wang,Ping Li 대한화학회 2014 Bulletin of the Korean Chemical Society Vol.35 No.9

The reaction mechanism between azacyclopropenylidene and epoxypropane has been systematically investigated employing the second-order Møller-Plesset perturbation theory (MP2) method to better understand the reactivity of azacyclopropenylidene with four-membered ring compound epoxypropane. Geometry optimization, vibrational analysis, and energy property for the involved stationary points on the potential energy surface have been calculated. It was found that for the first step of this reaction, azacyclopropenylidene can insert into epoxypropane at its C-O or C-C bond to form spiro intermediate IM. It is easier for the azacyclopropenylidene to insert into the C-O bond than the C-C bond. Through the ring-opened step at the C-C bond of azacyclopropenylidene fragment, IM can transfer to product P1, which is named as pathway (1). On the other hand, through the H-transferred step and subsequent ring-opened step at the C-N bond of azacyclopropenylidene fragment, IM can convert to product P2, which is named as pathway (2). From the thermodynamics viewpoint, the P2 characterized by an allene is the dominating product. From the kinetic viewpoint, the pathway (1) of formation to P1 is primary.

Theoretical Study on the Reaction Mechanism of Azacyclopropenylidene with Epoxypropane: An Insertion Process

Tan, Xiaojun,Wang, Weihua,Li, Ping Korean Chemical Society 2014 Bulletin of the Korean Chemical Society Vol.35 No.9

The reaction mechanism between azacyclopropenylidene and epoxypropane has been systematically investigated employing the second-order M${\o}$ller-Plesset perturbation theory (MP2) method to better understand the reactivity of azacyclopropenylidene with four-membered ring compound epoxypropane. Geometry optimization, vibrational analysis, and energy property for the involved stationary points on the potential energy surface have been calculated. It was found that for the first step of this reaction, azacyclopropenylidene can insert into epoxypropane at its C-O or C-C bond to form spiro intermediate IM. It is easier for the azacyclopropenylidene to insert into the C-O bond than the C-C bond. Through the ring-opened step at the C-C bond of azacyclopropenylidene fragment, IM can transfer to product P1, which is named as pathway (1). On the other hand, through the H-transferred step and subsequent ring-opened step at the C-N bond of azacyclopropenylidene fragment, IM can convert to product P2, which is named as pathway (2). From the thermodynamics viewpoint, the P2 characterized by an allene is the dominating product. From the kinetic viewpoint, the pathway (1) of formation to P1 is primary.

Theoretical Study on the Mechanism of the Addition Reaction between Cyclopropenylidene and Formaldehyde

Tan, Xiaojun,Li, Zhen,Sun, Qiao,Li, Ping,Wang, Weihua Korean Chemical Society 2012 Bulletin of the Korean Chemical Society Vol.33 No.6

The reaction mechanism between cyclopropenylidene and formaldehyde has been systematically investigated employing the MP2/6-311+$G^*$ level of theory to better understand the cyclopropenylidene reactivity with carbonyl compound. Geometry optimization, vibrational analysis, and energy property for the involved stationary points on the potential energy surface have been calculated. Energies of all the species are further corrected by the CCSD(T)/6-311+$G^*$ single-point calculations. It was found that one important reaction intermediate (INTa) has been located firstly $via$ a transition state (TSa). After that, the common intermediate (INTb) for the two pathways (1) and (2) has been formed $via$ TSb. At last, two different products possessing three- and four-membered ring characters have been obtained through two possible reaction pathways. In the reaction pathway (1), a three-membered ring alkyne compound has been obtained. As for the reaction pathway (2), it is the formation of the four-membered ring conjugated diene compound. The energy barrier of the ratedetermining step of pathway (1) is lower than that of the pathway (2), and the ultima product of pathway (2) is more stable than that of the pathway (1).

GAME MODEL AND ITS SOLVING METHOD FOR OPTIMAL SCALE OF POWER PLANTS ENTERING GENERATION POWER MARKET

Tan, Zhongfu,Chen, Guangjuan,Li, Xiaojun 한국전산응용수학회 2008 Journal of applied mathematics & informatics Vol.26 No.1

Based on social welfare maximum theory, the optimal scale of power plants entering generation power market being is researched. A static non-cooperative game model for short-term optimization of power plants with different cost is presented. And the equilibrium solutions and the total social welfare are obtained. According to principle of maximum social welfare selection, the optimization model is solved, optimal number of power plants entering the market is determined. The optimization results can not only increase the customer surplus and improve power production efficiency, but also sustain normal profits of power plants and scale economy of power production, and the waste of resource can also be avoided. At last, case results show that the proposed model is efficient.

Game model and its solving method for optimal scale of powerplants entering generation power market

Zhongfu Tan,Guangjuan Chen,Xiaojun Li 한국전산응용수학회 2008 Journal of applied mathematics & informatics Vol.26 No.1

Based on social welfare maximum theory, the optimal scale of power plants entering generation power market being is researched. A static non-cooperative game model for short-term optimization of power plants with different cost is presented. And the equilibrium solutions and the total social welfare are obtained. According to principle of maximum social welfare selection, the optimization model is solved, optimal number of power plants entering the market is determined. The optimization results can not only increase the customer surplus and improve power production efficiency, but also sustain normal profits of power plants and scale economy of power production, and the waste of resource can also be avoided. At last, case results show that the proposed model is efficient. Based on social welfare maximum theory, the optimal scale of power plants entering generation power market being is researched. A static non-cooperative game model for short-term optimization of power plants with different cost is presented. And the equilibrium solutions and the total social welfare are obtained. According to principle of maximum social welfare selection, the optimization model is solved, optimal number of power plants entering the market is determined. The optimization results can not only increase the customer surplus and improve power production efficiency, but also sustain normal profits of power plants and scale economy of power production, and the waste of resource can also be avoided. At last, case results show that the proposed model is efficient.