Two opposing explanations to significant rate retardation in dithioester-mediated polymerization with reversible addition fragmentation chain transfer process(RAFT),e.g: slow fragmentation of intermediate radicals (Mo...Two opposing explanations to significant rate retardation in dithioester-mediated polymerization with reversible addition fragmentation chain transfer process(RAFT),e.g: slow fragmentation of intermediate radicals (Model A),and cross termination between intermediates and growing radicals (Model B),had been proposed by Davis and Monteiro independently. In this paper,a comparison of simulation results of Model A and Model B with experiment results was presented. The simulated results show that the intermediate concentration of Model A is much higher than that of experiments,while Model B gives a rather high polymerization rate than experiments with large concentration of dithioesters. The reaction model was better fitted,in light of kinetics,intermediate concentration and distribution of molecular weight,to experimental data when both cross termination and slow fragmentation were taken into account. [WT5HZ]展开更多
The study aimed to test if Briganti’s 2012 nomogram could be associated with the risk of prostate cancer (PCa) progression in European Association of Urology (EAU) intermediate-risk patients treated with robotic surg...The study aimed to test if Briganti’s 2012 nomogram could be associated with the risk of prostate cancer (PCa) progression in European Association of Urology (EAU) intermediate-risk patients treated with robotic surgery. From January 2013 to December 2021, 527 consecutive patients belonging to the EAU intermediate-risk class were selected. Briganti’s 2012 nomogram, which predicts the risk of pelvic lymph node invasion (PLNI), was assessed as a continuous and dichotomous variable that categorized up to the median of 3.0%. Disease progression defined as biochemical recurrence and/or metastatic progression was evaluated by Cox proportional hazards (univariate and multivariate analysis). After a median follow-up of 95.0 months (95% confidence interval [CI]: 78.5–111.4), PCa progression occurred in 108 (20.5%) patients who were more likely to present with an unfavorable nomogram risk score, independently by the occurrence of unfavorable pathology including tumor upgrading and upstaging as well as PLNI. Accordingly, as Briganti’s 2012 risk score increased, patients were more likely to experience disease progression (hazard ratio [HR] = 1.060;95% CI: 1.021–1.100;P = 0.002);moreover, it also remained significant when dichotomized above a risk score of 3.0% (HR = 2.052;95% CI: 1.298–3.243;P < 0.0001) after adjustment for clinical factors. In the studied risk population, PCa progression was independently predicted by Briganti’s 2012 nomogram. Specifically, we found that patients were more likely to experience disease progression as their risk score increased. Because of the significant association between risk score and tumor behavior, the nomogram can further stratify intermediate-risk PCa patients, who represent a heterogeneous risk category for which different treatment paradigms exist.展开更多
In this nonsystematic review of the literature,we explored the changing landscape of detection and treatment of low-and intermediate-risk prostate cancer(PCa).Through emphasizing improved cancer assessment with histol...In this nonsystematic review of the literature,we explored the changing landscape of detection and treatment of low-and intermediate-risk prostate cancer(PCa).Through emphasizing improved cancer assessment with histology classification and genomics,we investigated key developments in PCa detection and risk stratification.The pivotal role of prostate magnetic resonance imaging(MRI)in the novel diagnostic pathway is examined,alongside the benefits and drawbacks of MRI-targeted biopsies for detection and tumor characterization.We also delved into treatment options,particularly active surveillance for intermediate-risk PCa.Outcomes are compared between intermediate-and low-risk patients,offering insights into tailored management.Surgical techniques,including Retzius-sparing surgery,precision prostatectomy,and partial prostatectomy for anterior cancer,are appraised.Each technique has the potential to enhance outcomes and minimize complications.Advancements in technology and radiobiology,including computed tomography(CT)/MRI imaging and positron emission tomography(PET)fusion,allow for precise dose adjustment and daily target monitoring with imaging-guided radiotherapy,opening new ways of tailoring patients’treatments.Finally,experimental therapeutic approaches such as focal therapy open new treatment frontiers,although they create new needs in tumor identification and tracking during and after the procedure.展开更多
We report ab initio UMP2 calculations of the reaction of CN with HNCO using 6-311G(d,p) basis sets.The obtained results show that the reaction has two product channels:HNCO+CN→HCN+NCO (1) and HNCO+CN→HNCN+CO (2).Cha...We report ab initio UMP2 calculations of the reaction of CN with HNCO using 6-311G(d,p) basis sets.The obtained results show that the reaction has two product channels:HNCO+CN→HCN+NCO (1) and HNCO+CN→HNCN+CO (2).Channel (1) is a hydrogen abstraction reaction,which is a concerted process.The calculated potential energy barrier is 20.80 kJ/mol at UMP2(full)/6-311G(d,p) level.In the range of reaction temperature (1000―2100 K),the conventional transition theory rate constant for channel (1) ranges from 0.32×10?11 to 6.9×10?11cm3?mol?1·s?1,which is close to the experimental value.Channel (2) is a stepwise re-action involving an intermediate during the process of reaction.The UMP2(full)/6-311G(d,p) po-tential energy barrier is 83.42 kJ/mol for the rate-controlling step,which is much higher than that of channel (1).展开更多
Eukaryotic genomic DNA is packed into chromatin, whose fundamental structural unit is the nucleosome. As DNA-histone protein complexes, nucleosomes show different properties toward exogenous and endogenous DNA-damagin...Eukaryotic genomic DNA is packed into chromatin, whose fundamental structural unit is the nucleosome. As DNA-histone protein complexes, nucleosomes show different properties toward exogenous and endogenous DNA-damaging agents. This review summarizes nucleosome DNA damage due to different sources, including alkylating agents, radicals, UV radiation and reactive DNA damage intermediates. In most cases, the histone core protects the associated DNA against damage via its structure and/or scavenging of damaging agents. In contrast, histones react with damaged DNA and, in some instances, catalyze DNA damage in the nucleosome. The biological consequence of nucleosome DNA damage and future prospects in this field are briefly discussed.展开更多
采用CCSD(T)//B3LYP/6-311+G(d,p)方法研究了Criegee中间体CH_3CHOO与OH自由基反应的微观机理.结果表明,上述反应存在抽氢、加成-分解和氧化3类反应通道,其中,syn-CH3CHOO+OH以抽β-H为优势通道,表观活化能为-4.88 k J/mol;anti-CH_3CHO...采用CCSD(T)//B3LYP/6-311+G(d,p)方法研究了Criegee中间体CH_3CHOO与OH自由基反应的微观机理.结果表明,上述反应存在抽氢、加成-分解和氧化3类反应通道,其中,syn-CH3CHOO+OH以抽β-H为优势通道,表观活化能为-4.88 k J/mol;anti-CH_3CHOO+OH则以加成-分解反应为优势通道,表观活化能为-13.25 k J/mol.在加成-分解和氧化反应通道中,anti-构象的能垒均低于syn-构象,而抽氢反应则是syn-(β-H)的能垒低于anti-构象.速率常数计算表明,anti-构象的加成-分解反应通道具有显著的负温度效应;syn-和anti-构象的氧化通道具有显著的正温度效应.3类反应具有显著不同的温度效应,说明通过改变温度可显著调节3类反应的相对速率.展开更多
文摘Two opposing explanations to significant rate retardation in dithioester-mediated polymerization with reversible addition fragmentation chain transfer process(RAFT),e.g: slow fragmentation of intermediate radicals (Model A),and cross termination between intermediates and growing radicals (Model B),had been proposed by Davis and Monteiro independently. In this paper,a comparison of simulation results of Model A and Model B with experiment results was presented. The simulated results show that the intermediate concentration of Model A is much higher than that of experiments,while Model B gives a rather high polymerization rate than experiments with large concentration of dithioesters. The reaction model was better fitted,in light of kinetics,intermediate concentration and distribution of molecular weight,to experimental data when both cross termination and slow fragmentation were taken into account. [WT5HZ]
文摘The study aimed to test if Briganti’s 2012 nomogram could be associated with the risk of prostate cancer (PCa) progression in European Association of Urology (EAU) intermediate-risk patients treated with robotic surgery. From January 2013 to December 2021, 527 consecutive patients belonging to the EAU intermediate-risk class were selected. Briganti’s 2012 nomogram, which predicts the risk of pelvic lymph node invasion (PLNI), was assessed as a continuous and dichotomous variable that categorized up to the median of 3.0%. Disease progression defined as biochemical recurrence and/or metastatic progression was evaluated by Cox proportional hazards (univariate and multivariate analysis). After a median follow-up of 95.0 months (95% confidence interval [CI]: 78.5–111.4), PCa progression occurred in 108 (20.5%) patients who were more likely to present with an unfavorable nomogram risk score, independently by the occurrence of unfavorable pathology including tumor upgrading and upstaging as well as PLNI. Accordingly, as Briganti’s 2012 risk score increased, patients were more likely to experience disease progression (hazard ratio [HR] = 1.060;95% CI: 1.021–1.100;P = 0.002);moreover, it also remained significant when dichotomized above a risk score of 3.0% (HR = 2.052;95% CI: 1.298–3.243;P < 0.0001) after adjustment for clinical factors. In the studied risk population, PCa progression was independently predicted by Briganti’s 2012 nomogram. Specifically, we found that patients were more likely to experience disease progression as their risk score increased. Because of the significant association between risk score and tumor behavior, the nomogram can further stratify intermediate-risk PCa patients, who represent a heterogeneous risk category for which different treatment paradigms exist.
文摘In this nonsystematic review of the literature,we explored the changing landscape of detection and treatment of low-and intermediate-risk prostate cancer(PCa).Through emphasizing improved cancer assessment with histology classification and genomics,we investigated key developments in PCa detection and risk stratification.The pivotal role of prostate magnetic resonance imaging(MRI)in the novel diagnostic pathway is examined,alongside the benefits and drawbacks of MRI-targeted biopsies for detection and tumor characterization.We also delved into treatment options,particularly active surveillance for intermediate-risk PCa.Outcomes are compared between intermediate-and low-risk patients,offering insights into tailored management.Surgical techniques,including Retzius-sparing surgery,precision prostatectomy,and partial prostatectomy for anterior cancer,are appraised.Each technique has the potential to enhance outcomes and minimize complications.Advancements in technology and radiobiology,including computed tomography(CT)/MRI imaging and positron emission tomography(PET)fusion,allow for precise dose adjustment and daily target monitoring with imaging-guided radiotherapy,opening new ways of tailoring patients’treatments.Finally,experimental therapeutic approaches such as focal therapy open new treatment frontiers,although they create new needs in tumor identification and tracking during and after the procedure.
文摘We report ab initio UMP2 calculations of the reaction of CN with HNCO using 6-311G(d,p) basis sets.The obtained results show that the reaction has two product channels:HNCO+CN→HCN+NCO (1) and HNCO+CN→HNCN+CO (2).Channel (1) is a hydrogen abstraction reaction,which is a concerted process.The calculated potential energy barrier is 20.80 kJ/mol at UMP2(full)/6-311G(d,p) level.In the range of reaction temperature (1000―2100 K),the conventional transition theory rate constant for channel (1) ranges from 0.32×10?11 to 6.9×10?11cm3?mol?1·s?1,which is close to the experimental value.Channel (2) is a stepwise re-action involving an intermediate during the process of reaction.The UMP2(full)/6-311G(d,p) po-tential energy barrier is 83.42 kJ/mol for the rate-controlling step,which is much higher than that of channel (1).
基金supported by the National Natural Science Foundation of China(21572109,21877064,21740002)the National Key R&D Program of China(2017YFD0200501)
文摘Eukaryotic genomic DNA is packed into chromatin, whose fundamental structural unit is the nucleosome. As DNA-histone protein complexes, nucleosomes show different properties toward exogenous and endogenous DNA-damaging agents. This review summarizes nucleosome DNA damage due to different sources, including alkylating agents, radicals, UV radiation and reactive DNA damage intermediates. In most cases, the histone core protects the associated DNA against damage via its structure and/or scavenging of damaging agents. In contrast, histones react with damaged DNA and, in some instances, catalyze DNA damage in the nucleosome. The biological consequence of nucleosome DNA damage and future prospects in this field are briefly discussed.
文摘采用CCSD(T)//B3LYP/6-311+G(d,p)方法研究了Criegee中间体CH_3CHOO与OH自由基反应的微观机理.结果表明,上述反应存在抽氢、加成-分解和氧化3类反应通道,其中,syn-CH3CHOO+OH以抽β-H为优势通道,表观活化能为-4.88 k J/mol;anti-CH_3CHOO+OH则以加成-分解反应为优势通道,表观活化能为-13.25 k J/mol.在加成-分解和氧化反应通道中,anti-构象的能垒均低于syn-构象,而抽氢反应则是syn-(β-H)的能垒低于anti-构象.速率常数计算表明,anti-构象的加成-分解反应通道具有显著的负温度效应;syn-和anti-构象的氧化通道具有显著的正温度效应.3类反应具有显著不同的温度效应,说明通过改变温度可显著调节3类反应的相对速率.
