In this paper, a calculation model based on the subsection displacement theory and the large deflection analysis is developed to describe the dynamic response of isotropic laminated circular plates impacted by a soft ...In this paper, a calculation model based on the subsection displacement theory and the large deflection analysis is developed to describe the dynamic response of isotropic laminated circular plates impacted by a soft body. The model takes into account the interlaminar shear effect induced by the middle weak layer. It is proved by numerical examples that the difference between the model developed in this paper and that based on the classical laminated theory mainly depends on three factors, the elastic modulus of the glue, the radius of the circular plate and the impact force.展开更多
By means of DTA TG, XRD, SEM etc ., the particles configuration, crystal structure, chemical composition and other physical properties of bastnasite rare earth polishing powder and fluorocarbonate rare earth pol...By means of DTA TG, XRD, SEM etc ., the particles configuration, crystal structure, chemical composition and other physical properties of bastnasite rare earth polishing powder and fluorocarbonate rare earth polishing powder were comparatively analyzed. The mechanism of the performance differences between two kinds of polishing powders was also investigated.展开更多
The carbon concentrating mechanism—C_(4) photosynthesis—represents a classic example of convergent evolution,but how this important trait originated and evolved remains largely enigmatic.The spider flower Gynandrops...The carbon concentrating mechanism—C_(4) photosynthesis—represents a classic example of convergent evolution,but how this important trait originated and evolved remains largely enigmatic.The spider flower Gynandropsis gynandra is a valuable leafy vegetable crop and medicinal plant that has also been recognized as a C_(4) model species.Here we present a high-quality chromosome-scale annotated genome assembly of G.gynandra through a combination of Oxford Nanopore Technology(ONT),HiFi and Hi-C technology.The 17 super-scaffolds cover 98.66% of the estimated genome(997.61 Mb),with a contig N50 of 11.43 Mb and a scaffold N50 of 51.02 Mb.Repetitive elements occupy up to 71.91% of its genome,and over half are long terminal repeat retrotransposons(LTR-RTs)derived from recent bursts,contributing to genome size expansion.Strikingly,LTR-RT explosion also played a critical role in C_(4) evolution by altering expression features of photosynthesis-associated genes via preferential insertion in promoters.Integrated multiomics analyses of G.gynandra and the ornamental horticulture C3 relative Tarenaya hassleriana reveal that species-specific whole-genome duplication,gene family expansion,recent LTR–RT amplification,and more recent tandem duplication events have all facilitated the evolution of C_(4) photosynthesis,revealing uniqueness of C_(4) evolution in the Cleome genus.Moreover,high leaf vein density and heat stress resilience are associated with shifted gene expression patterns.The mode of C_(3)-to-C_(4) transition found here yields new insights into evolutionary convergence of a complex plant trait.The availability of this reference-grade genomic resource makes G.gynandra an ideal model system facilitating efforts toward C4-aimed crop engineering.展开更多
Preterm birth is associated with abnormal brain structure.However,the underlying microstructural properties of cerebral cortical differences in infants born very preterm(VPT,<32 GW)and moderately-late preterm(MLPT,...Preterm birth is associated with abnormal brain structure.However,the underlying microstructural properties of cerebral cortical differences in infants born very preterm(VPT,<32 GW)and moderately-late preterm(MLPT,32-37 GW)at term-equivalent age(TEA)relative to full-term(FT)neonates were rarely explored.To achieve this,we use neurite orientation dispersion and density imaging(NODDI)and the method of gray matter-based spatial statistics(GBSS).33 VPT infants,40 MLPT infants)and 69 FT neonates with no evidence of local lesions on conventional MRI adopted from dHCP database were included in this study.By extracting the core voxels of cerebral cortex from the 142 individuals in the standard space,we compared the differences between preterm groups and FT group voxel-wisely.展开更多
Radiation shielding calculation plays a critical role in ensuring the safety of nuclear reactors.In the field of nuclear reactor shielding calculations,deterministic computing codes are commonly used due to their comp...Radiation shielding calculation plays a critical role in ensuring the safety of nuclear reactors.In the field of nuclear reactor shielding calculations,deterministic computing codes are commonly used due to their computational efficiency and capability to solve deep penetration problems.However,the accuracy of deterministic codes heavily relies on the precision of the multi-group cross section library^([1]).展开更多
With the widespread attention paid to the construction of functional molecular systems,chemical synthesis is increasingly pursuing the accurate and efficient combination and dissociation of molecular units to achieve ...With the widespread attention paid to the construction of functional molecular systems,chemical synthesis is increasingly pursuing the accurate and efficient combination and dissociation of molecular units to achieve specific functions[1].Carolyn R.Bertozzi,Morten Meldal,and K.Barry Sharpless,winners of the 2022 Nobel Prize in Chemistry,found that click chemistry works like LEGO bricks,using the basic block to build infinitely changing shape,which allows the molecular building block to be combined quickly and efficiently[2].展开更多
Co-existing organic compounds may affect the adsorption of perfluorinated compounds （PFCs） and carbon nanotubes in aquatic environments. Adsorption of perfluorooctane sulfonate （PFOS）, perfluorooctane acid （PFOA...Co-existing organic compounds may affect the adsorption of perfluorinated compounds （PFCs） and carbon nanotubes in aquatic environments. Adsorption of perfluorooctane sulfonate （PFOS）, perfluorooctane acid （PFOA）, perfluorobutane sulfonate （PFBS）, and perfluor- ohexane sulfonate （PFHxS） on the pristine multi-walled carbon nanotubes （MWCNTs-Pri）, carboxyl functionalized MWCNTs （MWCTNs-COOH）, and hydroxyl functiona- lized MWCNTs （MWCNTs-OH） in the presence of humic acid, 1-naphthol, phenol, and benzoic acid was studied. Adsorption kinetics of PFOS was described well by the pseudo-second-order model and the sorption equilibrium was almost reached within 24 h. The effect of co-existing organic compounds on PFOS adsorption followed the decreasing order of humic acid 〉 1-naphthol 〉 benzoic acid〉phenol. Adsorbed amounts of PFOS decreased significantly in the presence of co-existing or preloaded humic acid, and both adsorption energy and effective adsorption sites on the three MWCNTs decreased, resulting in the decrease of PFOS adsorption. With increasing pH, PFOS removal by three MWCNTs decreased in the presence of humic acid and phenol. The adsorbed amounts of different PFCs on the MWCNTs increased in the order ofPFBS 〈 PFHxS 〈 PFOA 〈 PFOS. The increase of both initial concentrations and the number of aromatic rings of co-existing organic compounds suppressed PFOS adsorption on the MWCNTs.展开更多
Silylated fluoroalkenes are important synthetic intermediates with complementary reactivity,which play a key role in the construction of natural products,pharmaceuticals,and manmade materials.Converting the normally h...Silylated fluoroalkenes are important synthetic intermediates with complementary reactivity,which play a key role in the construction of natural products,pharmaceuticals,and manmade materials.Converting the normally highly stable fiuoroalkenes into silylated fluoroalkenes by selective defluorosilylation is a challenging task.Herein,we report a simple,inexpensive and robust defluorosilylation of a variety of fluoroalkenes with silylboronates in the presence of alkoxy base to directly synthesize various silylated fluoroalkenes.The protocol features mild and safe reaction conditions that avoid a catalyst,a transition metal,a ligand,and high reaction temperature and tolerates a wide scope of fluoroalkene substrates without compromising the efficiency.Density functional theory calculations show that transient silyl anion complex undergoes an SN2,or SNv substitution,which is responsible for this base-mediated defluorosilylation.展开更多
Photoinduced nickel-catalyzed cross-coupling of arylsulfinates(ArSO_(2)^(−))with(hetero)aryl halides(Ar’–X)via visible light photoexcitation of 2-chloro-thioxanthen-9-one(Cl-TXO)has been achieved in moderate to exce...Photoinduced nickel-catalyzed cross-coupling of arylsulfinates(ArSO_(2)^(−))with(hetero)aryl halides(Ar’–X)via visible light photoexcitation of 2-chloro-thioxanthen-9-one(Cl-TXO)has been achieved in moderate to excellent yields.展开更多
Background Suboptimal neonatal circumcision analgesia causes a significant stress response.There is continued search for more effective analgesia for neonatal circumcision.We aimed to determine whether lidocaine–pril...Background Suboptimal neonatal circumcision analgesia causes a significant stress response.There is continued search for more effective analgesia for neonatal circumcision.We aimed to determine whether lidocaine–prilocaine cream(LPC)prior to dorsal penile nerve block(DPNB)offers better analgesia than DPNB alone.Methods A prospective randomized study of 72 neonates undergoing plastibell circumcision was randomized into two groups of 36 each.Group I received DPNB alone with 4 mg/kg plain lidocaine.Group II had 1 g LPC applied to the phallus 1 hour before DPNB.Serum cortisol levels were measured 30 min preoperatively and 30 min postoperatively.Heart rate(HR)and peripheral arterial oxygen saturation(SpO2)were noted at 30 min preoperatively,after DPNB injection,after excising the prepuce,and at 30 min thereafter.The primary outcome measure was change in serum cortisol levels,while secondary outcomes were changes in HR and SpO2.Results Both groups had increased mean serum cortisol levels,decreased mean SpO2 and increased mean HR from baseline.The rise in mean serum cortisol level was significantly lower in group II(8.09±4.53µg/dL)than that in group I(11.42±7.83µg/dL)(p=0.034).Changes in SpO2 and HR were significantly less in group II than that in group I patients(p<0.05),except for HR changes at 30 min after excision of the prepuce(p=0.086).Conclusion These data suggest that neonates who received LPC prior to DPNB experienced significantly less pain from plastibell circumcision than those who had DPNB alone.展开更多
Authigenic ferromanganese carbonates were first discovered in some shallow and hemipelagic areas by scientists abroad.These minerals have also been found on the offshore along China, especially in the South China Sea ...Authigenic ferromanganese carbonates were first discovered in some shallow and hemipelagic areas by scientists abroad.These minerals have also been found on the offshore along China, especially in the South China Sea (such as the Beibu Bay, the Sanya Bay and the continental shelf). Though the abundance of the carbonates展开更多
基金Project supported by the National Natural Science Foundation of China (No. 11032001)
文摘In this paper, a calculation model based on the subsection displacement theory and the large deflection analysis is developed to describe the dynamic response of isotropic laminated circular plates impacted by a soft body. The model takes into account the interlaminar shear effect induced by the middle weak layer. It is proved by numerical examples that the difference between the model developed in this paper and that based on the classical laminated theory mainly depends on three factors, the elastic modulus of the glue, the radius of the circular plate and the impact force.
文摘By means of DTA TG, XRD, SEM etc ., the particles configuration, crystal structure, chemical composition and other physical properties of bastnasite rare earth polishing powder and fluorocarbonate rare earth polishing powder were comparatively analyzed. The mechanism of the performance differences between two kinds of polishing powders was also investigated.
基金This work was supported by the Agricultural Sci-ence and Technology Innovation Project of the Chinese Academy of Agricultural Sciences(Grant CAAS-ASTIP-2021-OCRI)the National Natural Science Foundation of China(Grant 32072096)。
文摘The carbon concentrating mechanism—C_(4) photosynthesis—represents a classic example of convergent evolution,but how this important trait originated and evolved remains largely enigmatic.The spider flower Gynandropsis gynandra is a valuable leafy vegetable crop and medicinal plant that has also been recognized as a C_(4) model species.Here we present a high-quality chromosome-scale annotated genome assembly of G.gynandra through a combination of Oxford Nanopore Technology(ONT),HiFi and Hi-C technology.The 17 super-scaffolds cover 98.66% of the estimated genome(997.61 Mb),with a contig N50 of 11.43 Mb and a scaffold N50 of 51.02 Mb.Repetitive elements occupy up to 71.91% of its genome,and over half are long terminal repeat retrotransposons(LTR-RTs)derived from recent bursts,contributing to genome size expansion.Strikingly,LTR-RT explosion also played a critical role in C_(4) evolution by altering expression features of photosynthesis-associated genes via preferential insertion in promoters.Integrated multiomics analyses of G.gynandra and the ornamental horticulture C3 relative Tarenaya hassleriana reveal that species-specific whole-genome duplication,gene family expansion,recent LTR–RT amplification,and more recent tandem duplication events have all facilitated the evolution of C_(4) photosynthesis,revealing uniqueness of C_(4) evolution in the Cleome genus.Moreover,high leaf vein density and heat stress resilience are associated with shifted gene expression patterns.The mode of C_(3)-to-C_(4) transition found here yields new insights into evolutionary convergence of a complex plant trait.The availability of this reference-grade genomic resource makes G.gynandra an ideal model system facilitating efforts toward C4-aimed crop engineering.
文摘Preterm birth is associated with abnormal brain structure.However,the underlying microstructural properties of cerebral cortical differences in infants born very preterm(VPT,<32 GW)and moderately-late preterm(MLPT,32-37 GW)at term-equivalent age(TEA)relative to full-term(FT)neonates were rarely explored.To achieve this,we use neurite orientation dispersion and density imaging(NODDI)and the method of gray matter-based spatial statistics(GBSS).33 VPT infants,40 MLPT infants)and 69 FT neonates with no evidence of local lesions on conventional MRI adopted from dHCP database were included in this study.By extracting the core voxels of cerebral cortex from the 142 individuals in the standard space,we compared the differences between preterm groups and FT group voxel-wisely.
文摘Radiation shielding calculation plays a critical role in ensuring the safety of nuclear reactors.In the field of nuclear reactor shielding calculations,deterministic computing codes are commonly used due to their computational efficiency and capability to solve deep penetration problems.However,the accuracy of deterministic codes heavily relies on the precision of the multi-group cross section library^([1]).
文摘With the widespread attention paid to the construction of functional molecular systems,chemical synthesis is increasingly pursuing the accurate and efficient combination and dissociation of molecular units to achieve specific functions[1].Carolyn R.Bertozzi,Morten Meldal,and K.Barry Sharpless,winners of the 2022 Nobel Prize in Chemistry,found that click chemistry works like LEGO bricks,using the basic block to build infinitely changing shape,which allows the molecular building block to be combined quickly and efficiently[2].
基金We thank the National Nature Science Foundation of China （Grant No. 21177070）, Tsinghua University Initiative Scientific Research Program （Nos. 20141081174 and 20131089251）, and Collaborative Innovation Center for Regional Environmental Quality for financial support.
文摘Co-existing organic compounds may affect the adsorption of perfluorinated compounds （PFCs） and carbon nanotubes in aquatic environments. Adsorption of perfluorooctane sulfonate （PFOS）, perfluorooctane acid （PFOA）, perfluorobutane sulfonate （PFBS）, and perfluor- ohexane sulfonate （PFHxS） on the pristine multi-walled carbon nanotubes （MWCNTs-Pri）, carboxyl functionalized MWCNTs （MWCTNs-COOH）, and hydroxyl functiona- lized MWCNTs （MWCNTs-OH） in the presence of humic acid, 1-naphthol, phenol, and benzoic acid was studied. Adsorption kinetics of PFOS was described well by the pseudo-second-order model and the sorption equilibrium was almost reached within 24 h. The effect of co-existing organic compounds on PFOS adsorption followed the decreasing order of humic acid 〉 1-naphthol 〉 benzoic acid〉phenol. Adsorbed amounts of PFOS decreased significantly in the presence of co-existing or preloaded humic acid, and both adsorption energy and effective adsorption sites on the three MWCNTs decreased, resulting in the decrease of PFOS adsorption. With increasing pH, PFOS removal by three MWCNTs decreased in the presence of humic acid and phenol. The adsorbed amounts of different PFCs on the MWCNTs increased in the order ofPFBS 〈 PFHxS 〈 PFOA 〈 PFOS. The increase of both initial concentrations and the number of aromatic rings of co-existing organic compounds suppressed PFOS adsorption on the MWCNTs.
基金the National Natural Science Foundation of China(Grants Nos.2167020084 and 21673110)the"Innovation&Entrepreneurship Talents Plan7'of Jiangsu Province for their financial support.
文摘Silylated fluoroalkenes are important synthetic intermediates with complementary reactivity,which play a key role in the construction of natural products,pharmaceuticals,and manmade materials.Converting the normally highly stable fiuoroalkenes into silylated fluoroalkenes by selective defluorosilylation is a challenging task.Herein,we report a simple,inexpensive and robust defluorosilylation of a variety of fluoroalkenes with silylboronates in the presence of alkoxy base to directly synthesize various silylated fluoroalkenes.The protocol features mild and safe reaction conditions that avoid a catalyst,a transition metal,a ligand,and high reaction temperature and tolerates a wide scope of fluoroalkene substrates without compromising the efficiency.Density functional theory calculations show that transient silyl anion complex undergoes an SN2,or SNv substitution,which is responsible for this base-mediated defluorosilylation.
基金The authors thank the National Natural Science Foundation of China(21971182 and 21771131)the“Priority Academic Program Development”of Jiangsu Higher Education Institutions.
文摘Photoinduced nickel-catalyzed cross-coupling of arylsulfinates(ArSO_(2)^(−))with(hetero)aryl halides(Ar’–X)via visible light photoexcitation of 2-chloro-thioxanthen-9-one(Cl-TXO)has been achieved in moderate to excellent yields.
文摘Background Suboptimal neonatal circumcision analgesia causes a significant stress response.There is continued search for more effective analgesia for neonatal circumcision.We aimed to determine whether lidocaine–prilocaine cream(LPC)prior to dorsal penile nerve block(DPNB)offers better analgesia than DPNB alone.Methods A prospective randomized study of 72 neonates undergoing plastibell circumcision was randomized into two groups of 36 each.Group I received DPNB alone with 4 mg/kg plain lidocaine.Group II had 1 g LPC applied to the phallus 1 hour before DPNB.Serum cortisol levels were measured 30 min preoperatively and 30 min postoperatively.Heart rate(HR)and peripheral arterial oxygen saturation(SpO2)were noted at 30 min preoperatively,after DPNB injection,after excising the prepuce,and at 30 min thereafter.The primary outcome measure was change in serum cortisol levels,while secondary outcomes were changes in HR and SpO2.Results Both groups had increased mean serum cortisol levels,decreased mean SpO2 and increased mean HR from baseline.The rise in mean serum cortisol level was significantly lower in group II(8.09±4.53µg/dL)than that in group I(11.42±7.83µg/dL)(p=0.034).Changes in SpO2 and HR were significantly less in group II than that in group I patients(p<0.05),except for HR changes at 30 min after excision of the prepuce(p=0.086).Conclusion These data suggest that neonates who received LPC prior to DPNB experienced significantly less pain from plastibell circumcision than those who had DPNB alone.
文摘Authigenic ferromanganese carbonates were first discovered in some shallow and hemipelagic areas by scientists abroad.These minerals have also been found on the offshore along China, especially in the South China Sea (such as the Beibu Bay, the Sanya Bay and the continental shelf). Though the abundance of the carbonates
