Enantiomeric molecules generally play distinct functions in chemistry,biology,and pharmacology.Similar physical and chemical properties of chiral analytes lay difficulty in discrimination and quantification of the ena...Enantiomeric molecules generally play distinct functions in chemistry,biology,and pharmacology.Similar physical and chemical properties of chiral analytes lay difficulty in discrimination and quantification of the enantiomers.We report herein an efficient approach of increasing the chiral sensing ability ofβ-cyclodextrin(β-CD),a widely used host molecule,in the hostguest chemistry by magnetic anisotropy.A rigid and chiral lanthanide binding tag was attached to theβ-CD to amplify the changes of nuclear magnetic resonance(NMR)signals in the host-guest recognition process.The installation of the paramagnetic lanthanide ion inβ-CD greatly enhances the enantiomeric discrimination up to 30-fold in comparison with the diamagneticβ-CD reference.In addition,the magnitude of the paramagnetic effects is tunable according to the diverse range of paramagnetic strength of the lanthanide series.The reported method significantly increases the chiral sensing ability ofβ-CD,which can be applied to other host molecules.The transferred paramagnetic effects,pseudocontact shifts(PCSs)and paramagnetic relaxation enhancements(PREs),from the host to the guest molecules,are valuable structural restraints to determine the absolute stereochemistry of the chiral analytes.The strategy does not need modification of the analytes and is complementary to the reported analytical methods that rely on the functionalization of the chiral analytes.展开更多
Phrenic nerve transfer is a major dynamic treatment used to repair brachial plexus root avulsion. We analyzed 72 relevant articles on phrenic nerve transfer to repair injured brachial plexus that were indexed by Scien...Phrenic nerve transfer is a major dynamic treatment used to repair brachial plexus root avulsion. We analyzed 72 relevant articles on phrenic nerve transfer to repair injured brachial plexus that were indexed by Science Citation Index. The keywords searched were brachial plexus injury, phrenic nerve, repair, surgery, protection, nerve transfer, and nerve graft. In addition, we per-formed neurophysiological analysis of the preoperative condition and prognosis of 10 patients undergoing ipsilateral phrenic nerve transfer to the musculocutaneous nerve in our hospital from 2008 to 201 3 and observed the electromyograms of the biceps brachii and motor conduc-tion function of the musculocutaneous nerve. Clinically, approximately 28% of patients had brachial plexus injury combined with phrenic nerve injury, and injured phrenic nerve cannot be used as a nerve graft. After phrenic nerve transfer to the musculocutaneous nerve, the regener-ated potentials ifrst appeared at 3 months. Recovery of motor unit action potential occurred 6 months later and became more apparent at 12 months. The percent of patients recovering ‘ex-cellent’ and ‘good’ muscle strength in the biceps brachii was 80% after 18 months. At 12 months after surgery, motor nerve conduction potential appeared in the musculocutaneous nerve in seven cases. These data suggest that preoperative evaluation of phrenic nerve function may help identify the most appropriate nerve graft in patients with an injured brachial plexus. The func-tional recovery of a transplanted nerve can be dynamically observed after the surgery.展开更多
Objective To develop an optimized BZK gel with good pharmaceutical effect and less toxicity to vaginal mucosa. Methods Four methods as below were used to research the spermicidal activity of BZK gel： 1） in vitro spe...Objective To develop an optimized BZK gel with good pharmaceutical effect and less toxicity to vaginal mucosa. Methods Four methods as below were used to research the spermicidal activity of BZK gel： 1） in vitro spermicidal test; 2） in vivo spermicidal test in rabbits; 3） anti-fertility test in rabbits; 4） contraceptive test in rabbits. Mucosal irritation test was used in rats to evaluate the safety of optimized BZK gel. Microbiological assessments were used to research anti-STI pathogens （including treponema pallidum, neisseria gonorrhoeae, trichomona vaginalis, candida albicans, ureaplama urealyticum, herpes simplex virus type-2, chlamydiae trachomatis） effect of optimized BZK gel. Results In vitro spermicidal test, EC50 of BZK gel was 0.029mg/ml, a little higher than that of N-9 （0.019mg/ml）. The MIC of BZK gel was 0.25mg/ml, similar to that of N-9 （0.20mg/ml）. The vaginal mucosal irritation test in rats showed that 0.429% BZK gel showed only minimal vaginal irritation, and did not damage the vaginal epithelium or cause local inflammation in rats. Microbiological assessments showed that optimized BZK gel could inhibit or inactivate common ST1 pathogens even after 3-fold or 5-fold dilution. Conclusion Optimized BZK gel was an effective microbicides.展开更多
We present a double-layered control algorithm to plan the local trajectory for automated trucks equipped with four hub motors. The main layer of the proposed control algorithm consists of a main layer nonlinear model ...We present a double-layered control algorithm to plan the local trajectory for automated trucks equipped with four hub motors. The main layer of the proposed control algorithm consists of a main layer nonlinear model predictive control(MLN-MPC) controller and a secondary layer nonlinear MPC(SLN-MPC) controller. The MLN-MPC controller is applied to plan a dynamically feasible trajectory, and the SLN-MPC controller is designed to limit the longitudinal slip of wheels within a stable zone to avoid the tire excessively slipping during traction. Overall, this is a closed-loop control system. Under the off-line co-simulation environments of AMESim, Simulink, dSPACE, and TruckSim, a dynamically feasible trajectory with collision avoidance operation can be generated using the proposed method, and the longitudinal wheel slip can be constrained within a stable zone so that the driving safety of the truck can be ensured under uncertain road surface conditions. In addition, the stability and robustness of the method are verified by adding a driver model to evaluate the application in the real world. Furthermore, simulation results show that there is lower computational cost compared with the conventional PID-based control method.展开更多
Deflectable nose control is a new trajectory correction method.In this paper,the aerodynamic and trajectory characteristics of a typical mortar projectile with a deflectable nose are investigated with respect to its f...Deflectable nose control is a new trajectory correction method.In this paper,the aerodynamic and trajectory characteristics of a typical mortar projectile with a deflectable nose are investigated with respect to its flight conditions.Using the method of wind tunnel testing,the aerodynamic coefficients of four kinds of mortar models were measured under the conditions of different angles of attack from-10°to 10°and Mach numbers from 0.3 to 0.9.Based on the aerodynamic coefficients,the trajectory ranges at different nose deflection angles and times were calculated.Furthermore,a trajectory optimization was performed by reducing the static margin.The results and discussions show that the nose deflection provided limited lift,while the pitching moment varied significantly.The mortar obtained the extended flight range and trajectory correction ability with nose deflection.展开更多
This article indicates by example about power price of Henan province that the energy resources of Henan province are ＂the commons＂. According to analysis of the game of ＂the tragedy of the commons＂, this article ...This article indicates by example about power price of Henan province that the energy resources of Henan province are ＂the commons＂. According to analysis of the game of ＂the tragedy of the commons＂, this article demonstrates that, whether under complete information or not, energy commons are abused. Based upon the situation, the author gives out the strategy to solve ＂the tragedy of the commons＂ of China energy sources.展开更多
Epidemiological surveys and animal experiments have shown that 2-bromopropane induces oligozoospermia in exposed workers and inhibits spermatogensis in laborratory animals. However, themechanism by which 2-bromopropan...Epidemiological surveys and animal experiments have shown that 2-bromopropane induces oligozoospermia in exposed workers and inhibits spermatogensis in laborratory animals. However, themechanism by which 2-bromopropane exerts its effects is unknown. To this end, we examined the formation of testosterone by the Leydig cells and their survival of these cells in the Presence of differ-ent concentrations of 2-bromopropane in vitro. Leydig cells were isolated following vascular Perfu-sion, enzymatic dissociation and Percoll gradient centrifugation techniques. The cells were cultured in culture dishes. After 8 h, different cultures were exposed to 2-bromopropane at concentrations of 0.01 mmol/L, 0.10 mmol/L and 1.00 mmol/L. In order to stimulate Leydig cells to secrete testos-terone, human chorionic gonadotropin (hCG) was also added. Cell viability was determined using the trypan blue dye exclusion test and cell numbers were counted by hemocytometer. Testosterone secretion was detected by radioimmunoassay. The cell viability decreased after exposure to 2-bromo-propane in a dose-dependent way, but no morphological change was observed. The cell number de-creased in the 2-bromopropane-treated cultures. The secretion of testosterone did not manifest de -tectable changes in the culture treated with 0.10 mmol/L and 0.01 mmol/L of 2-bromopropane;however, it decreased significantly (P < 0. 02) in the Presence of 1.00 mmol/L. Therefore, ourresults strongly suggest that 2-bromopropane may exert its cytotoxic effects on heydig cells in vitro.We speculate that the decrease in the numbers of Leydig cells caused by 2-bromopropane was medi-ated by a feedback mechanism resulting from a lower testosterone concentration.展开更多
The Sahelian region of Mali is one of the areas seriously affected by sandy desertification in the world. Widely distributed aeolian sand lays a material basis for the development of sandy desertification. Aeolian san...The Sahelian region of Mali is one of the areas seriously affected by sandy desertification in the world. Widely distributed aeolian sand lays a material basis for the development of sandy desertification. Aeolian sand in the region is dominated by fine sand, followed by very fine sand. Sand materials contained in various sand dunes are different in grain size to a certain extent and the mineral compositions of dune sand are dominated by stable and extreme stable minerals, with high stability and maturity. Aeolian sand in the region mainly comes from the reactivation of ancient sand dunes, the transportation of recent runing water and the sand supply of dry lakes and arroyos. Since the Pliocene this region has experienced four major evolution periods of aelian sand, namely from the Pliocene to the early Quaternary, last glacial period, the Holocene and present.展开更多
The nonlinear oscillatory phenomenon has been observed in the system of immune response, which corresponds to the limit cycles in the mathematical models. We prove that the system simulating an immune response studied...The nonlinear oscillatory phenomenon has been observed in the system of immune response, which corresponds to the limit cycles in the mathematical models. We prove that the system simulating an immune response studied by Huang has at least three limit cycles in the system. The conditions for the multiple limit cycles are useful in analyzing the nonlinear oscillation in immune response.展开更多
基金supported by the Ministry of Science and Technology of China(2021YFA1600304)the National Natural Science Foundation of China(22161142018,21991081,22174074,22374126)。
文摘Enantiomeric molecules generally play distinct functions in chemistry,biology,and pharmacology.Similar physical and chemical properties of chiral analytes lay difficulty in discrimination and quantification of the enantiomers.We report herein an efficient approach of increasing the chiral sensing ability ofβ-cyclodextrin(β-CD),a widely used host molecule,in the hostguest chemistry by magnetic anisotropy.A rigid and chiral lanthanide binding tag was attached to theβ-CD to amplify the changes of nuclear magnetic resonance(NMR)signals in the host-guest recognition process.The installation of the paramagnetic lanthanide ion inβ-CD greatly enhances the enantiomeric discrimination up to 30-fold in comparison with the diamagneticβ-CD reference.In addition,the magnitude of the paramagnetic effects is tunable according to the diverse range of paramagnetic strength of the lanthanide series.The reported method significantly increases the chiral sensing ability ofβ-CD,which can be applied to other host molecules.The transferred paramagnetic effects,pseudocontact shifts(PCSs)and paramagnetic relaxation enhancements(PREs),from the host to the guest molecules,are valuable structural restraints to determine the absolute stereochemistry of the chiral analytes.The strategy does not need modification of the analytes and is complementary to the reported analytical methods that rely on the functionalization of the chiral analytes.
基金funded by the National High Technology Research and Development Program of China(863 Program),No.2008AA022400a grant from Science&Technology Department of Sichuan Province of China,No.2009JY0174
文摘Phrenic nerve transfer is a major dynamic treatment used to repair brachial plexus root avulsion. We analyzed 72 relevant articles on phrenic nerve transfer to repair injured brachial plexus that were indexed by Science Citation Index. The keywords searched were brachial plexus injury, phrenic nerve, repair, surgery, protection, nerve transfer, and nerve graft. In addition, we per-formed neurophysiological analysis of the preoperative condition and prognosis of 10 patients undergoing ipsilateral phrenic nerve transfer to the musculocutaneous nerve in our hospital from 2008 to 201 3 and observed the electromyograms of the biceps brachii and motor conduc-tion function of the musculocutaneous nerve. Clinically, approximately 28% of patients had brachial plexus injury combined with phrenic nerve injury, and injured phrenic nerve cannot be used as a nerve graft. After phrenic nerve transfer to the musculocutaneous nerve, the regener-ated potentials ifrst appeared at 3 months. Recovery of motor unit action potential occurred 6 months later and became more apparent at 12 months. The percent of patients recovering ‘ex-cellent’ and ‘good’ muscle strength in the biceps brachii was 80% after 18 months. At 12 months after surgery, motor nerve conduction potential appeared in the musculocutaneous nerve in seven cases. These data suggest that preoperative evaluation of phrenic nerve function may help identify the most appropriate nerve graft in patients with an injured brachial plexus. The func-tional recovery of a transplanted nerve can be dynamically observed after the surgery.
文摘Objective To develop an optimized BZK gel with good pharmaceutical effect and less toxicity to vaginal mucosa. Methods Four methods as below were used to research the spermicidal activity of BZK gel： 1） in vitro spermicidal test; 2） in vivo spermicidal test in rabbits; 3） anti-fertility test in rabbits; 4） contraceptive test in rabbits. Mucosal irritation test was used in rats to evaluate the safety of optimized BZK gel. Microbiological assessments were used to research anti-STI pathogens （including treponema pallidum, neisseria gonorrhoeae, trichomona vaginalis, candida albicans, ureaplama urealyticum, herpes simplex virus type-2, chlamydiae trachomatis） effect of optimized BZK gel. Results In vitro spermicidal test, EC50 of BZK gel was 0.029mg/ml, a little higher than that of N-9 （0.019mg/ml）. The MIC of BZK gel was 0.25mg/ml, similar to that of N-9 （0.20mg/ml）. The vaginal mucosal irritation test in rats showed that 0.429% BZK gel showed only minimal vaginal irritation, and did not damage the vaginal epithelium or cause local inflammation in rats. Microbiological assessments showed that optimized BZK gel could inhibit or inactivate common ST1 pathogens even after 3-fold or 5-fold dilution. Conclusion Optimized BZK gel was an effective microbicides.
基金Project supported by the National Fund for Fundamental Research,China(No.282017Y-5303)the National Natural Science Foundation of China(Nos.51805312 and 51675324)+4 种基金the Shanghai Sailing Program,China(No.18YF1409400)the Training and Funding Program of Shanghai College Young Teachers,China(No.ZZGCD15102)the Scientific Research Project of Shanghai University of Engineering Science,China(No.2016-19)the Shanghai University of Engineering Science Innovation Fund for Graduate Students,China(No.18KY0610)the Technology and Innovation Projects of Guangxi Province,China(No.2017-393)。
文摘We present a double-layered control algorithm to plan the local trajectory for automated trucks equipped with four hub motors. The main layer of the proposed control algorithm consists of a main layer nonlinear model predictive control(MLN-MPC) controller and a secondary layer nonlinear MPC(SLN-MPC) controller. The MLN-MPC controller is applied to plan a dynamically feasible trajectory, and the SLN-MPC controller is designed to limit the longitudinal slip of wheels within a stable zone to avoid the tire excessively slipping during traction. Overall, this is a closed-loop control system. Under the off-line co-simulation environments of AMESim, Simulink, dSPACE, and TruckSim, a dynamically feasible trajectory with collision avoidance operation can be generated using the proposed method, and the longitudinal wheel slip can be constrained within a stable zone so that the driving safety of the truck can be ensured under uncertain road surface conditions. In addition, the stability and robustness of the method are verified by adding a driver model to evaluate the application in the real world. Furthermore, simulation results show that there is lower computational cost compared with the conventional PID-based control method.
文摘Deflectable nose control is a new trajectory correction method.In this paper,the aerodynamic and trajectory characteristics of a typical mortar projectile with a deflectable nose are investigated with respect to its flight conditions.Using the method of wind tunnel testing,the aerodynamic coefficients of four kinds of mortar models were measured under the conditions of different angles of attack from-10°to 10°and Mach numbers from 0.3 to 0.9.Based on the aerodynamic coefficients,the trajectory ranges at different nose deflection angles and times were calculated.Furthermore,a trajectory optimization was performed by reducing the static margin.The results and discussions show that the nose deflection provided limited lift,while the pitching moment varied significantly.The mortar obtained the extended flight range and trajectory correction ability with nose deflection.
文摘This article indicates by example about power price of Henan province that the energy resources of Henan province are ＂the commons＂. According to analysis of the game of ＂the tragedy of the commons＂, this article demonstrates that, whether under complete information or not, energy commons are abused. Based upon the situation, the author gives out the strategy to solve ＂the tragedy of the commons＂ of China energy sources.
文摘Epidemiological surveys and animal experiments have shown that 2-bromopropane induces oligozoospermia in exposed workers and inhibits spermatogensis in laborratory animals. However, themechanism by which 2-bromopropane exerts its effects is unknown. To this end, we examined the formation of testosterone by the Leydig cells and their survival of these cells in the Presence of differ-ent concentrations of 2-bromopropane in vitro. Leydig cells were isolated following vascular Perfu-sion, enzymatic dissociation and Percoll gradient centrifugation techniques. The cells were cultured in culture dishes. After 8 h, different cultures were exposed to 2-bromopropane at concentrations of 0.01 mmol/L, 0.10 mmol/L and 1.00 mmol/L. In order to stimulate Leydig cells to secrete testos-terone, human chorionic gonadotropin (hCG) was also added. Cell viability was determined using the trypan blue dye exclusion test and cell numbers were counted by hemocytometer. Testosterone secretion was detected by radioimmunoassay. The cell viability decreased after exposure to 2-bromo-propane in a dose-dependent way, but no morphological change was observed. The cell number de-creased in the 2-bromopropane-treated cultures. The secretion of testosterone did not manifest de -tectable changes in the culture treated with 0.10 mmol/L and 0.01 mmol/L of 2-bromopropane;however, it decreased significantly (P < 0. 02) in the Presence of 1.00 mmol/L. Therefore, ourresults strongly suggest that 2-bromopropane may exert its cytotoxic effects on heydig cells in vitro.We speculate that the decrease in the numbers of Leydig cells caused by 2-bromopropane was medi-ated by a feedback mechanism resulting from a lower testosterone concentration.
文摘The Sahelian region of Mali is one of the areas seriously affected by sandy desertification in the world. Widely distributed aeolian sand lays a material basis for the development of sandy desertification. Aeolian sand in the region is dominated by fine sand, followed by very fine sand. Sand materials contained in various sand dunes are different in grain size to a certain extent and the mineral compositions of dune sand are dominated by stable and extreme stable minerals, with high stability and maturity. Aeolian sand in the region mainly comes from the reactivation of ancient sand dunes, the transportation of recent runing water and the sand supply of dry lakes and arroyos. Since the Pliocene this region has experienced four major evolution periods of aelian sand, namely from the Pliocene to the early Quaternary, last glacial period, the Holocene and present.
文摘The nonlinear oscillatory phenomenon has been observed in the system of immune response, which corresponds to the limit cycles in the mathematical models. We prove that the system simulating an immune response studied by Huang has at least three limit cycles in the system. The conditions for the multiple limit cycles are useful in analyzing the nonlinear oscillation in immune response.
